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Liang C, Zhu D, Xia W, Hong Z, Wang QS, Sun Y, Yang YC, Han SQ, Tang LL, Lou J, Wu MM, Zhang ZR. Inhibition of YAP by lenvatinib in endothelial cells increases blood pressure through ferroptosis. Biochim Biophys Acta Mol Basis Dis 2023; 1869:166586. [PMID: 36374802 DOI: 10.1016/j.bbadis.2022.166586] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 10/25/2022] [Accepted: 10/25/2022] [Indexed: 11/07/2022]
Abstract
Lenvatinib, a multitarget tyrosine kinase inhibitor (TKI), increases the incidence of severe hypertension and thus the incidence of cardiovascular complications. Inhibition of ferroptosis, a newly recognized type of cell death, alleviates endothelial dysfunction. Here, we report that lenvatinib-induced hypertension is associated with ferroptosis of endothelial cells. RNA sequencing (RNA-seq) showed that lenvatinib led to ferroptosis of endothelial cells and that administration of mouse with ferrostatin-1 (Fer-1), a specific ferroptosis inhibitor, dramatically ameliorated lenvatinib-induced hypertension and reversed lenvatinib-induced impairment of endothelium-dependent relaxation (EDR). Furthermore, lenvatinib significantly reduced glutathione peroxidase 4 (GPX4) expressions in the mouse aorta and human umbilical vein endothelial cells (HUVECs) and increased lipid peroxidation, lactate dehydrogenase (LDH) release, and malondialdehyde (MDA) levels in HUVECs. Immunofluorescence and Western blotting showed that lenvatinib significantly reduced Yes-associated protein (YAP) nuclear translocation but not cytoplasmic YAP expression in HUVECs. The data, generated from both in vivo and in vitro, showed that lenvatinib reduced total YAP (t-YAP) expression and increased the phosphorylation of YAP at both Ser127 and Ser397, without affecting YAP mRNA levels in HUVECs. XMU-MP-1 mediated YAP activation or YAP overexpression effectively attenuated the lenvatinib-induced decrease in GPX4 expression and increases in LDH release and MDA levels. In addition, overexpression of YAP in HUVECs ameliorated lenvatinib-induced decrease in the mRNA and protein levels of spermidine/spermine N (1)-acetyltransferase-1 (SAT1), heme oxygenase-1 (HO-1), and ferritin heavy chain 1 (FTH1). Taken together, our data suggest that lenvatinib-induced inhibition of YAP led to ferroptosis of endothelial cells and subsequently resulted in vascular dysfunction and hypertension.
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Affiliation(s)
- Chen Liang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, PR China; Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key Laboratory for Metabolic Disorder & Cancer Related Cardiovascular Diseases, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, PR China
| | - Di Zhu
- Departments of Cardiology, Central Laboratory, The First Affiliated Hospital of Harbin Medical University, NHC Key Laboratory of Cell Transplantation, Harbin Medical University, PR China; Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key Laboratory for Metabolic Disorder & Cancer Related Cardiovascular Diseases, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, PR China
| | - Wei Xia
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, PR China; Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key Laboratory for Metabolic Disorder & Cancer Related Cardiovascular Diseases, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, PR China
| | - Zi Hong
- Departments of Cardiology, Central Laboratory, The First Affiliated Hospital of Harbin Medical University, NHC Key Laboratory of Cell Transplantation, Harbin Medical University, PR China; Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key Laboratory for Metabolic Disorder & Cancer Related Cardiovascular Diseases, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, PR China
| | - Qiu-Shi Wang
- Departments of Cardiology, Central Laboratory, The First Affiliated Hospital of Harbin Medical University, NHC Key Laboratory of Cell Transplantation, Harbin Medical University, PR China; Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key Laboratory for Metabolic Disorder & Cancer Related Cardiovascular Diseases, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, PR China
| | - Yu Sun
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, PR China; Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key Laboratory for Metabolic Disorder & Cancer Related Cardiovascular Diseases, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, PR China
| | - Yan-Chao Yang
- Departments of Cardiology, Central Laboratory, The First Affiliated Hospital of Harbin Medical University, NHC Key Laboratory of Cell Transplantation, Harbin Medical University, PR China; Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key Laboratory for Metabolic Disorder & Cancer Related Cardiovascular Diseases, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, PR China
| | - Song-Qi Han
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, PR China; Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key Laboratory for Metabolic Disorder & Cancer Related Cardiovascular Diseases, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, PR China
| | - Liang-Liang Tang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, PR China; Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key Laboratory for Metabolic Disorder & Cancer Related Cardiovascular Diseases, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, PR China
| | - Jie Lou
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, PR China; Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key Laboratory for Metabolic Disorder & Cancer Related Cardiovascular Diseases, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, PR China
| | - Ming-Ming Wu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, PR China; Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key Laboratory for Metabolic Disorder & Cancer Related Cardiovascular Diseases, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, PR China
| | - Zhi-Ren Zhang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, PR China; Departments of Cardiology, Central Laboratory, The First Affiliated Hospital of Harbin Medical University, NHC Key Laboratory of Cell Transplantation, Harbin Medical University, PR China; Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key Laboratory for Metabolic Disorder & Cancer Related Cardiovascular Diseases, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, PR China.
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Tang LL, Yang X, Yu SQ, Qin Q, Xue R, Sun Y, Xiao H, Shang AQ, Liu JQ, Han SQ, Liang C, Lou J, Wang QS, Yu CJ, Wu MM, Zhang ZR. Aldosterone-stimulated endothelial epithelial sodium channel (EnNaC) plays a role in cold exposure–induced hypertension in rats. Front Pharmacol 2022; 13:970812. [PMID: 36278222 PMCID: PMC9582121 DOI: 10.3389/fphar.2022.970812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 09/16/2022] [Indexed: 11/13/2022] Open
Abstract
Background: Previous studies have demonstrated that activated endothelial epithelial sodium channel (EnNaC) impairs vasodilatation, which contributes to salt-sensitive hypertension. Here, we investigate whether mesenteric artery (MA) EnNaC is involved in cold exposure–induced hypertension (CIH) and identify the underlying mechanisms in SD rats.Methods: One group of rats was housed at room temperature and served as control. Three groups of rats were kept in a 4°C cold incubator for 10 h/day; among which two groups were administrated with either benzamil (EnNaC blocker) or eplerenone (mineralocorticoid receptor antagonist, MR). Blood pressure (BP), vasodilatation, and endothelial function were measured with tail-cuff plethysmography, isometric myograph, and Total Nitric Oxide (NO) Assay kit, respectively. A cell-attached patch-clamp technique, in split-open MA, was used to determine the role of EnNaC in CIH rats. Furthermore, the plasma aldosterone levels were detected using an ELISA kit; and Western blot analysis was used to examine the relative expression levels of Sgk1 and Nedd4-2 proteins in the MA of SD rats.Results: We demonstrated that cold exposure increased BP, impaired vasodilatation, and caused endothelial dysfunction in rats. The activity of EnNaC significantly increased, concomitant with an increased level of plasma aldosterone and activation of Sgk1/Nedd4-2 signaling. Importantly, CIH was inhibited by either eplerenone or benzamil. It appeared that cold-induced decrease in NO production and impairment of endothelium-dependent relaxation (EDR) were significantly ameliorated by either eplerenone or benzamil in MA of CIH rats. Moreover, treatment of MAs with aldosterone resulted in an activation of EnNaC, a reduction of NO, and an impairment of EDR, which were significantly inhibited by either eplerenone or GSK650394 (Sgk1 inhibitor) or benzamil.Conclusion: Activation of EnNaC contributes to CIH; we suggest that pharmacological inhibition of the MR/Sgk1/Nedd4-2/EnNaC axis may be a potential therapeutic strategy for CIH.
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Affiliation(s)
- Liang-Liang Tang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Xu Yang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Shu-Qi Yu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Qi Qin
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Rong Xue
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Yu Sun
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Han Xiao
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - An-Qi Shang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Jia-Qun Liu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Song-Qi Han
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Chen Liang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Jie Lou
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Qiu-Shi Wang
- Department of Cardiology, the 1st Affiliated Hospital of Harbin Medical University, NHC Key Laboratory of Cell Transplantation, Harbin Medical University and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Chang-Jiang Yu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Ming-Ming Wu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
| | - Zhi-Ren Zhang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, Harbin, China
- Department of Cardiology, the 1st Affiliated Hospital of Harbin Medical University, NHC Key Laboratory of Cell Transplantation, Harbin Medical University and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
- *Correspondence: Zhi-Ren Zhang,
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Liang C, Wang QS, Yang X, Zhu D, Sun Y, Niu N, Yao J, Dong BH, Jiang S, Tang LL, Lou J, Yu CJ, Shao Q, Wu MM, Zhang ZR. Homocysteine Causes Endothelial Dysfunction via Inflammatory Factor-Mediated Activation of Epithelial Sodium Channel (ENaC). Front Cell Dev Biol 2021; 9:672335. [PMID: 34222246 PMCID: PMC8247579 DOI: 10.3389/fcell.2021.672335] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 05/18/2021] [Indexed: 11/24/2022] Open
Abstract
Background Hyperhomocysteinemia (HHcy) causes cardiovascular diseases via regulating inflammatory responses. We investigated whether and how the epithelial sodium channel (ENaC), a recently identified ion channel in endothelial cells, plays a role in HHcy-induced endothelial dysfunction. Methods Cell-attached patch-clamp recording in acute split-open aortic endothelial cells, western blot, confocal imaging, and wire myograph combined with pharmacological approaches were used to determine whether HHcy-mediated inflammatory signaling leads to endothelial dysfunction via stimulating ENaC. Results The data showed that 4 weeks after L-methionine diet the levels of plasma Hcy were significantly increased and the ENaC was dramatically activated in mouse aortic endothelial cells. Administration of benzamil, a specific ENaC blocker, ameliorated L-methionine diet-induced impairment of endothelium-dependent relaxation (EDR) and reversed Hcy-induced increase in ENaC activity. Pharmacological inhibition of NADPH oxidase, reactive oxygen species (ROS), cyclooxygenase-2 (COX-2)/thromboxane B2 (TXB2), or serum/glucocorticoid regulated kinase 1 (SGK1) effectively attenuated both the Hcy-induced activation of endothelial ENaC and impairment of EDR. Our in vitro data showed that both NADPH oxidase inhibitor and an ROS scavenger reversed Hcy-induced increase in COX-2 expression in human umbilical vein endothelial cells (HUVECs). Moreover, Hcy-induced increase in expression levels of SGK-1, phosphorylated-SGK-1, and phosphorylated neural precursor cell-expressed developmentally downregulated protein 4-2 (p-Nedd4-2) in HUVECs were significantly blunted by a COX-2 inhibitor. Conclusion We show that Hcy activates endothelial ENaC and subsequently impairs EDR of mouse aorta, via ROS/COX-2-dependent activation of SGK-1/Nedd4-2 signaling. Our study provides a rational that blockade of the endothelial ENaC could be potential method to prevent and/or to treat Hcy-induced cardiovascular disease.
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Affiliation(s)
- Chen Liang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Qiu-Shi Wang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Xu Yang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Di Zhu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Yu Sun
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Na Niu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Jie Yao
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Bi-Han Dong
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Shuai Jiang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Liang-Liang Tang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Jie Lou
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Chang-Jiang Yu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Qun Shao
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Ming-Ming Wu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Zhi-Ren Zhang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang Key Laboratory for Metabolic Disorder and Cancer Related Cardiovascular Diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
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Wang QS, Liang C, Jiang S, Zhu D, Sun Y, Niu N, Yang X, Yang YC, Dong BH, Yao J, Yu CJ, Lou J, Tang LL, Wu MM, Zhang ZR, Ma HP. NaHS or Lovastatin Attenuates Cyclosporine A-Induced Hypertension in Rats by Inhibiting Epithelial Sodium Channels. Front Pharmacol 2021; 12:665111. [PMID: 34122084 PMCID: PMC8187945 DOI: 10.3389/fphar.2021.665111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 04/19/2021] [Indexed: 12/01/2022] Open
Abstract
The use of cyclosporine A (CsA) in transplant recipients is limited due to its side effects of causing severe hypertension. We have previously shown that CsA increases the activity of the epithelial sodium channel (ENaC) in cultured distal nephron cells. However, it remains unknown whether ENaC mediates CsA-induced hypertension and how we could prevent hypertension. Our data show that the open probability of ENaC in principal cells of split-open cortical collecting ducts was significantly increased after treatment of rats with CsA; the increase was attenuated by lovastatin. Moreover, CsA also elevated the levels of intracellular cholesterol (Cho), intracellular reactive oxygen species (ROS) via activation of NADPH oxidase p47phox, serum- and glucocorticoid-induced kinase isoform 1 (Sgk1), and phosphorylated neural precursor cell–expressed developmentally downregulated protein 4–2 (p-Nedd4-2) in the kidney cortex. Lovastatin also abolished CsA-induced elevation of α-, ß-, and γ-ENaC expressions. CsA elevated systolic blood pressure in rats; the elevation was completely reversed by lovastatin (an inhibitor of cholesterol synthesis), NaHS (a donor of H2S which ameliorated CsA-induced elevation of reactive oxygen species), or amiloride (a potent ENaC blocker). These results suggest that CsA elevates blood pressure by increasing ENaC activity via a signaling cascade associated with elevation of intracellular ROS, activation of Sgk1, and inactivation of Nedd4-2 in an intracellular cholesterol-dependent manner. Our data also show that NaHS ameliorates CsA-induced hypertension by inhibition of oxidative stress.
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Affiliation(s)
- Qiu-Shi Wang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China.,Department of Physiology, Emory University School of Medicine, Atlanta, GA, United States
| | - Chen Liang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Shuai Jiang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Di Zhu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Yu Sun
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Na Niu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Xu Yang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Yan-Chao Yang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Bi-Han Dong
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Jie Yao
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Chang-Jiang Yu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Jie Lou
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Liang-Liang Tang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Ming-Ming Wu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Zhi-Ren Zhang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - He-Ping Ma
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, United States
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Cai YX, Zhang BL, Yu M, Yang YC, Ao X, Zhu D, Wang QS, Lou J, Liang C, Tang LL, Wu MM, Zhang ZR, Ma HP. Cholesterol Stimulates the Transient Receptor Potential Melastatin 4 Channel in mpkCCD c14 Cells. Front Pharmacol 2021; 12:627875. [PMID: 34054517 PMCID: PMC8160378 DOI: 10.3389/fphar.2021.627875] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 04/21/2021] [Indexed: 11/24/2022] Open
Abstract
We have shown that cholesterol regulates the activity of ion channels in mouse cortical collecting duct (CCD) mpkCCDc14 cells and that the transient receptor potential melastatin 4 (TRPM4) channel is expressed in these cells. However, whether TRPM4 channel is regulated by cholesterol remains unclear. Here, we performed inside-out patch-clamp experiments and found that inhibition of cholesterol biosynthesis by lovastatin significantly decreased, whereas enrichment of cholesterol with exogenous cholesterol significantly increased, TRPM4 channel open probability (Po) by regulating its sensitivity to Ca2+ in mpkCCDc14 cells. In addition, inside-out patch-clamp data show that acute depletion of cholesterol in the membrane inner leaflet by methyl-β-cyclodextrin (MβCD) significantly reduced TRPM4 Po, which was reversed by exogenous cholesterol. Moreover, immunofluorescence microscopy, Western blot, cell-surface biotinylation, and patch clamp analysis show that neither inhibition of intracellular cholesterol biosynthesis with lovastatin nor application of exogenous cholesterol had effect on TRPM4 channel protein abundance in the plasma membrane of mpkCCDc14 cells. Sucrose density gradient centrifugation studies demonstrate that TRPM4 was mainly located in cholesterol-rich lipid rafts. Lipid-protein overlay experiments show that TRPM4 directly interacted with several anionic phospholipids, including PI(4,5)P2. Depletion of PI(4,5)P2 with either wortmannin or PGE2 abrogated the stimulatory effects of exogenous cholesterol on TRPM4 activity, whereas exogenous PI(4,5)P2 (diC8-PI(4,5)P2, a water-soluble analog) increased the effects. These results suggest that cholesterol stimulates TRPM4 via a PI(4,5)P2-dependent mechanism.
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Affiliation(s)
- Yong-Xu Cai
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder and cancer related cardiovascular diseases, and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Bao-Long Zhang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder and cancer related cardiovascular diseases, and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Miao Yu
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder and cancer related cardiovascular diseases, and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Yan-Chao Yang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder and cancer related cardiovascular diseases, and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Xue Ao
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder and cancer related cardiovascular diseases, and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Di Zhu
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder and cancer related cardiovascular diseases, and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Qiu-Shi Wang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder and cancer related cardiovascular diseases, and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Jie Lou
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder and cancer related cardiovascular diseases, and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Chen Liang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder and cancer related cardiovascular diseases, and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Liang-Liang Tang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder and cancer related cardiovascular diseases, and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Ming-Ming Wu
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder and cancer related cardiovascular diseases, and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China.,Department of Physiology, Emory University School of Medicine, Atlanta, GA, United States
| | - Zhi-Ren Zhang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder and cancer related cardiovascular diseases, and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China.,NHC Key Laboratory of Cell Transplantation, Harbin Medical University, Harbin, China
| | - He-Ping Ma
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, United States
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6
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Liu Y, Tang LL, Liang C, Wu MM, Zhang ZR. Insulin Resistance and Pellino-1 Mediated Decrease in the Activities of Vasodilator Signaling Contributes to Sunitinib-Induced Hypertension. Front Pharmacol 2021; 12:617165. [PMID: 33841146 PMCID: PMC8027079 DOI: 10.3389/fphar.2021.617165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 01/21/2021] [Indexed: 01/10/2023] Open
Abstract
Antiangiogenic tyrosine kinases inhibitors induce hypertension, which may increase the incidents of cardiovascular complications and limit their use. However, the mechanisms by which usage of TKIs results in hypertension have not been fully understood. Here, we report the potential mechanisms of how sunitinib, a widely used TKI, induces hypertension. Male SD rats were randomly divided into control group and sunitinib-administrated group. We show that sunitinib administration for seven days caused a significant increase in artery blood pressure, along with glycerolipid metabolism abnormalities including decreased food intake and low body weight, hypoglycemia, hyperinsulinemia. Sunitinib administration also resulted in a significant increase in the levels of insulin autoantibody (IAA), cyclic adenosine monophosphate and free fatty acid in serum; whereas, sunitinib administration had no effects on serum glucagon levels. Sunitinib led to the decreased insulin sensitivity as determined by insulin tolerance test (ITT) and glucose tolerance test (GTT), reflecting insulin resistance occurred in sunitinib-treated rats. The results obtained from wire myograph assay in the mesenteric arteries show that endothelium-dependent relaxation, but not endothelium-independent relaxation, was impaired by sunitinib. Furthermore, western blot analysis revealed that the expressions levels of phosphorylated IRS-1, Pellino-1, AKT and eNOS were significantly attenuated by sunitinib in rat mesenteric artery tissues and in the sunitinib-treated primary cultured mesenteric artery endothelial cells. The levels of serum and endothelium-derived nitric oxide were also significantly decreased by sunitinib. Moreover, sunitinib-induced decrease in the expression levels of phosphorylated AKT and eNOS was further reduced by knocking down of Pellino-1 in MAECs. Our results suggest that sunitinib causes vascular dysfunction and hypertension, which are associated with insulin resistance- and Pellino-1-mediated inhibition of AKT/eNOS/NO signaling. Our results may provide a rational for preventing and/or treating sunitinib-induced endothelial dysfunction and hypertension.
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Affiliation(s)
- Yang Liu
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder and cancer related cardiovascular diseases, and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Liang-Liang Tang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder and cancer related cardiovascular diseases, and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Chen Liang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder and cancer related cardiovascular diseases, and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Ming-Ming Wu
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder and cancer related cardiovascular diseases, and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Zhi-Ren Zhang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder and cancer related cardiovascular diseases, and Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China.,NHC Key Laboratory of Cell Transplantation, Harbin Medical University, Harbin, China
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7
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Niu N, Yang X, Zhang BL, Liang C, Zhu D, Wang QS, Cai YX, Yang YC, Ao X, Wu MM, Zhang ZR. Endothelial epithelial sodium channel involves in high-fat diet-induced atherosclerosis in low-density lipoprotein receptor-deficient mice. Biochim Biophys Acta Mol Basis Dis 2020; 1867:165989. [PMID: 33065235 DOI: 10.1016/j.bbadis.2020.165989] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 09/05/2020] [Accepted: 10/05/2020] [Indexed: 12/15/2022]
Abstract
We previously showed that increased epithelial sodium channel (ENaC) activity in endothelial cells induced by oxidized low-density lipoprotein (ox-LDL) contributes to vasculature dysfunction. Here, we investigated whether ENaC participates in the pathological process of atherosclerosis using LDL receptor-deficient (LDLr-/-) mice. Male C57BL/6 and LDLr-/- mice were fed a normal diet (ND) or high fat diet (HFD) for 10 weeks. Our data show that treatment of LDLr-/- mice with a specific ENaC blocker, benzamil, significantly decreased atherosclerotic lesion formation and expression of matrix metalloproteinase 2 (MMP2) and metalloproteinase 9 (MMP9) in aortic arteries. Furthermore, benzamil ameliorated HFD-induced impairment of aortic endothelium-dependent dilation by reducing expression of proinflammatory cytokines, including TNF-α, IL-1β, and IL-6 and production of adhesion molecules including VCAM-1 and ICAM-1 in both C57BL/6 and LDLr-/- mice fed with HFD. In addition, HFD significantly increased ENaC activity and the levels of serum lipids, including ox-LDL. Our in vitro data further demonstrated that exogenous ox-LDL significantly increased the production of TNF-α, IL-1β, IL-6, VCAM-1 and ICAM-1. This ox-LDL-induced increase in inflammatory cytokines and adhesion molecules was reversed by γ-ENaC silencing or by treatment with the cyclooxygenase-2 (COX-2) antagonist celecoxib. Benzamil inhibited HFD-induced increase in COX-2 expression in aortic tissue in both C57BL/6 and LDLr-/- mice, and γ-ENaC gene silencing attenuated ox-LDL-induced COX-2 expression in HUVECs. These data together suggest that HFD-induced activation of ENaC stimulates inflammatory signaling, thereby contributes to HFD-induced endothelial dysfunction and atherosclerotic lesion formation. Thus, targeting endothelial ENaC may be a promising strategy to halt atherogenesis.
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Affiliation(s)
- Na Niu
- Departments of Clinical Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, 150081, China
| | - Xu Yang
- Departments of Clinical Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, 150081, China
| | - Bao-Long Zhang
- Departments of Clinical Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, 150081, China
| | - Chen Liang
- Departments of Clinical Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, 150081, China
| | - Di Zhu
- Departments of Clinical Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, 150081, China
| | - Qiu-Shi Wang
- Departments of Clinical Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, 150081, China
| | - Yong-Xu Cai
- Departments of Clinical Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, 150081, China
| | - Yan-Chao Yang
- Departments of Clinical Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, 150081, China
| | - Xue Ao
- Departments of Clinical Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, 150081, China
| | - Ming-Ming Wu
- Departments of Clinical Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, 150081, China
| | - Zhi-Ren Zhang
- Departments of Clinical Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, 150081, China.
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8
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Zhai YJ, Wu MM, Linck VA, Zou L, Yue Q, Wei SP, Song C, Zhang S, Williams CR, Song BL, Zhang ZR, Ma HP. Intracellular cholesterol stimulates ENaC by interacting with phosphatidylinositol‑4,5‑bisphosphate and mediates cyclosporine A-induced hypertension. Biochim Biophys Acta Mol Basis Dis 2019; 1865:1915-1924. [PMID: 31109455 DOI: 10.1016/j.bbadis.2018.08.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 08/04/2018] [Accepted: 08/19/2018] [Indexed: 12/31/2022]
Abstract
We have previously shown that blockade of ATP-binding cassette transporter A1 (ABCA1) with cyclosporine A (CsA) stimulates the epithelial sodium channel (ENaC) in cultured distal nephron cells. Here we show that CsA elevated systolic blood pressure in both wild-type and apolipoprotein E (ApoE) knockout (KO) mice to a similar level. The elevated systolic blood pressure was completely reversed by inhibition of cholesterol (Cho) synthesis with lovastatin. Inside-out patch-clamp data show that intracellular Cho stimulated ENaC in cultured distal nephron cells by interacting with phosphatidylinositol‑4,5‑bisphosphate (PIP2), an ENaC activator. Confocal microscopy data show that both α‑ENaC and PIP2 were localized in microvilli via a Cho-dependent mechanism. Deletion of membrane Cho reduced the levels of γ‑ENaC in the apical membrane. Reduced ABCA1 expression and elevated intracellular Cho were observed in old mice, compared to young mice. In parallel, cell-attached patch-clamp data from the split-open cortical collecting ducts (CCD) show that ENaC activity was significantly increased in old mice. These data suggest that elevation of intracellular Cho due to blockade of ABCA1 stimulates ENaC, which may contribute to CsA-induced hypertension. This study also implies that reduced ABCA1 expression may mediate age-related hypertension by increasing ENaC activity via elevation of intracellular Cho.
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Affiliation(s)
- Yu-Jia Zhai
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Ming-Ming Wu
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Cardiology, Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin 150081, China
| | - Valerie A Linck
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Li Zou
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Qiang Yue
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Shi-Peng Wei
- Department of Internal Medicine, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Chang Song
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Shuai Zhang
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Clintoria R Williams
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Bin-Lin Song
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA; Department of Cardiology, Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin 150081, China
| | - Zhi-Ren Zhang
- Department of Cardiology, Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin 150081, China.
| | - He-Ping Ma
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, USA.
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9
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Yu CJ, Wang QS, Wu MM, Song BL, Liang C, Lou J, Tang LL, Yu XD, Niu N, Yang X, Zhang BL, Qu Y, Liu Y, Dong ZC, Zhang ZR. TRUSS Exacerbates NAFLD Development by Promoting IκBα Degradation in Mice. Hepatology 2018; 68:1769-1785. [PMID: 29704259 DOI: 10.1002/hep.30066] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 04/20/2018] [Indexed: 12/15/2022]
Abstract
There is no effective treatment method for nonalcoholic fatty liver disease (NAFLD), the most common liver disease. The exact mechanism underlying the pathogenesis of NAFLD remains to be elucidated. Here, we report that tumor necrosis factor receptor-associated ubiquitous scaffolding and signaling protein (TRUSS) acts as a positive regulator of NAFLD and in a variety of metabolic disorders. TRUSS expression was increased in the human liver specimens with NAFLD or nonalcoholic steatohepatitis, and in the livers of high-fat diet (HFD)-induced and genetically obese mice. Conditional knockout of TRUSS in hepatocytes significantly ameliorated hepatic steatosis, insulin resistance, glucose intolerance, and inflammatory responses in mice after HFD challenge or in spontaneous obese mice with normal chow feeding. All of these HFD-induced pathological phenotypes were exacerbated in mice overexpressing TRUSS in hepatocytes. We show that TRUSS physically interacts with the inhibitor of nuclear factor κB α (IκBα) and promotes the ubiquitination and degradation of IκBα, which leads to aberrant activation of nuclear factor κB (NF-κB). Overexpressing IκBαS32A/S36A , a phosphorylation-resistant mutant of IκBα, in the hepatocyte-specific TRUSS overexpressing mice almost abolished HFD-induced NAFLD and metabolic disorders. Conclusion: Hepatocyte TRUSS promotes pathological stimuli-induced NAFLD and metabolic disorders, through activation of NF-κB by promoting ubiquitination and degradation of IκBα. Our findings may provide a strategy for the prevention and treatment of NAFLD by targeting TRUSS.
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Affiliation(s)
- Chang-Jiang Yu
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Qiu-Shi Wang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Ming-Ming Wu
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Bin-Lin Song
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Chen Liang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Jie Lou
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Liang-Liang Tang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Xiao-Di Yu
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Na Niu
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Xu Yang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Bao-Long Zhang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Yao Qu
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Yang Liu
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Zhi-Chao Dong
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Zhi-Ren Zhang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
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10
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You ML, Chen YJ, Chong QY, Wu MM, Pandey V, Chen RM, Liu L, Ma L, Wu ZS, Zhu T, Lobie PE. Trefoil factor 3 mediation of oncogenicity and chemoresistance in hepatocellular carcinoma is AKT-BCL-2 dependent. Oncotarget 2018; 8:39323-39344. [PMID: 28445151 PMCID: PMC5503616 DOI: 10.18632/oncotarget.16950] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 03/07/2017] [Indexed: 12/14/2022] Open
Abstract
The efficacious treatment of hepatocellular carcinoma (HCC) remains a challenge, partially being attributed to intrinsic chemoresistance. Previous reports have observed increased TFF3 expression in HCC. Herein, we investigated the functional role of TFF3 in progression of HCC, and in both intrinsic and acquired chemoresistance. TFF3 expression was observed to be upregulated in HCC and associated with poor clinicopathological features and worse patient survival outcome. Functionally, forced expression of TFF3 in HCC cell lines increased cell proliferation, cell survival, anchorage-independent and 3D matrigel growth, cell invasion and migration, and in vivo tumor growth. In contrast, depleted expression of TFF3 decreased the oncogenicity of HCC cells as indicated by the above parameters. Furthermore, forced expression of TFF3 decreased doxorubicin sensitivity of HCC cells, which was attributed to increased doxorubicin efflux and cancer stem cell-like behavior of Hep3B cells. In contrast, depletion of TFF3 increased doxorubicin sensitivity and decreased cancer stem cell-like behavior of Hep3B cells. Correspondingly, TFF3 expression was markedly increased in Hep3B cells with acquired doxorubicin resistance, while the depletion of TFF3 resulted in re-sensitization of the Hep3B cells to doxorubicin. The increased doxorubicin efflux and enhanced cancer stem cell-like behavior of the doxorubicin-resistant Hep3B cells was observed to be dependent on TFF3 expression. In addition, we determined that TFF3-stimulated oncogenicity and chemoresistance in HCC cells was mediated by AKT-dependent expression of BCL-2. Hence, therapeutic inhibition of TFF3 should be considered to hinder HCC progression and overcome intrinsic and acquired chemoresistance in HCC.
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Affiliation(s)
- Ming-Liang You
- Cancer Science Institute of Singapore and Department of Pharmacology, National University of Singapore, Singapore
| | - Yi-Jun Chen
- Cancer Science Institute of Singapore and Department of Pharmacology, National University of Singapore, Singapore
| | - Qing-Yun Chong
- Cancer Science Institute of Singapore and Department of Pharmacology, National University of Singapore, Singapore
| | - Ming-Ming Wu
- Hefei National Laboratory for Physical Sciences at Microscale Hefei, Anhui, China.,The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui, China
| | - Vijay Pandey
- Cancer Science Institute of Singapore and Department of Pharmacology, National University of Singapore, Singapore
| | - Ru-Mei Chen
- Cancer Science Institute of Singapore and Department of Pharmacology, National University of Singapore, Singapore
| | - Liang Liu
- Department of Oncology and Department of Radiology, Fudan University Shanghai Cancer Center, Fudan University, Shanghai, China
| | - Lan Ma
- Tsinghua Berkeley Shenzhen Institute (TBSI), Shenzhen, China
| | - Zheng-Sheng Wu
- Department of Pathology, Anhui Medical University, Hefei, Anhui, China
| | - Tao Zhu
- Hefei National Laboratory for Physical Sciences at Microscale Hefei, Anhui, China.,The CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences and Medical Center, University of Science and Technology of China, Hefei, Anhui, China
| | - Peter E Lobie
- Cancer Science Institute of Singapore and Department of Pharmacology, National University of Singapore, Singapore.,Tsinghua Berkeley Shenzhen Institute (TBSI), Shenzhen, China
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11
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Zhai YJ, Liu BC, Wei SP, Chou CF, Wu MM, Song BL, Linck V, Zou L, Zhang S, Li XQ, Zhang ZR, Ma HP. Depletion of Cholesterol Reduces ENaC Activity by Decreasing Phosphatidylinositol-4,5-Bisphosphate in Microvilli. Cell Physiol Biochem 2018; 47:1051-1059. [DOI: 10.1159/000490170] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 04/10/2018] [Indexed: 11/19/2022] Open
Abstract
Background/Aims: The epithelial sodium channel (ENaC) in cortical collecting duct (CCD) principal cells plays a critical role in regulating systemic blood pressure. We have previously shown that cholesterol (Cho) in the apical cell membrane regulates ENaC; however, the underlying mechanism remains unclear. Methods: Patch-clamp technique and confocal microscopy were used to evaluate ENaC activity and density. Results: Here we show that extraction of membrane Cho with methyl-β-cyclodextrin (MβCD) significantly reduced amiloride-sensitive current and ENaC single-channel activity. The effects were reproduced by inhibition of Cho synthesis in the cells with lovastatin. We have previously shown that phosphatidylinositol-4,5-bisphosphate (PIP2), an ENaC activator, is predominantly located in the microvilli, a specialized apical membrane domain. Here, our confocal microscopy data show that α-ENaC was co-localized with PIP2 in the microvilli and that Cho was also co-localized with PIP2 in the microvilli. Either extraction of Cho with MβCD or inhibition of Cho synthesis with lovastatin consistently reduced the levels of Cho, PIP2, and ENaC in the microvilli. Conclusions: Since PIP2 can directly stimulate ENaC and also affect ENaC trafficking, these data suggest that depletion of Cho reduces ENaC apical density and activity at least in part by decreasing PIP2 in the microvilli.
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Liang C, Wang QS, Yang X, Niu N, Hu QQ, Zhang BL, Wu MM, Yu CJ, Chen X, Song BL, Zhang ZR, Ma HP. Oxidized low-density lipoprotein stimulates epithelial sodium channels in endothelial cells of mouse thoracic aorta. Br J Pharmacol 2017; 175:1318-1328. [PMID: 28480509 DOI: 10.1111/bph.13853] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 04/14/2017] [Accepted: 05/03/2017] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND AND PURPOSE The epithelial sodium channel (ENaC) is expressed in endothelial cells and acts as a negative modulator of vasodilatation. Oxidized LDL (ox-LDL) is a key pathological factor in endothelial dysfunction. In the present study we examined the role of ENaC in ox-LDL-induced endothelial dysfunction and its associated signal transduction pathway. EXPERIMENTAL APPROACH Patch clamp techniques combined with pharmacological approaches were used to examine ENaC activity in the endothelial cells of a split-open mouse thoracic aorta. Western blot analysis was used to determine ENaC expression in the aorta. The aorta relaxation was measured using a wire myograph assay. KEY RESULTS Ox-LDL, but not LDL, significantly increased ENaC activity in the endothelial cells attached to split-open thoracic aortas, and the increase was inhibited by a lectin-like ox-LDL receptor-1 (LOX-1) antagonist (κ-carrageenan), an NADPH oxidase inhibitor (apocynin), and a scavenger of ROS (TEMPOL). Sodium nitroprusside, an NO donor, diminished the ox-LDL-mediated activation of ENaC, and this effect was abolished by inhibiting soluble guanylate cyclase (sGC) and PKG. Ox-LDL reduced the endothelium-dependent vasodilatation of the aorta pectoralis induced by ACh, and this reduction was partially restored by blocking ENaC. CONCLUSION AND IMPLICATIONS Ox-LDL stimulates ENaC in endothelial cells through LOX-1 receptor-mediated activation of NADPH oxidase and accumulation of intracellular ROS. Since the stimulation of ENaC can be reversed by elevating NO, we suggest that both inhibition of ENaC and an elevation of NO may protect the endothelium from ox-LDL-induced dysfunction. LINKED ARTICLES This article is part of a themed section on Spotlight on Small Molecules in Cardiovascular Diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.8/issuetoc.
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Affiliation(s)
- Chen Liang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Qiu-Shi Wang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Xu Yang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Na Niu
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Qing-Qing Hu
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Bao-Long Zhang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Ming-Ming Wu
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Chang-Jiang Yu
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Xiao Chen
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Bin-Lin Song
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Zhi-Ren Zhang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - He-Ping Ma
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia, USA
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Wang ZR, Liu HB, Sun YY, Hu QQ, Li YX, Zheng WW, Yu CJ, Li XY, Wu MM, Song BL, Mu JJ, Yuan ZY, Zhang ZR, Ma HP. Dietary salt blunts vasodilation by stimulating epithelial sodium channels in endothelial cells from salt-sensitive Dahl rats. Br J Pharmacol 2017; 175:1305-1317. [PMID: 28409833 DOI: 10.1111/bph.13817] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 03/26/2017] [Accepted: 04/04/2017] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND AND PURPOSE Our recent studies show that the reduced activity of epithelial sodium channels (ENaC) in endothelial cells accounts for the adaptation of vasculature to salt in Sprague-Dawley rats. The present study examines a hypothesis that enhanced ENaC activity mediates the loss of vasorelaxation in Dahl salt-sensitive (SS) rats. EXPERIMENTAL APPROACH We used the cell-attached patch-clamp technique to record ENaC activity in split-open mesenteric arteries. Western blot and immunofluorescence staining were used to evaluate the levels of aldosterone, ENaC, eNOS and NO. Blood pressure was measured with the tail-cuff method and the artery relaxation was measured with the wire myograph assay. KEY RESULTS High-salt (HS) diet significantly increased plasma aldosterone and ENaC activity in the endothelial cells of Dahl SS rats. The endothelium-dependent artery relaxation was blunted by HS challenge in these rats. Amiloride, a potent blocker of ENaC, increased both phosphorylated eNOS and NO and therefore prevented the HS-induced loss of vasorelaxation. As, in SS rats, endogenous aldosterone was already elevated by HS challenge, exogenous aldosterone did not further elevate ENaC activity in the rats fed with HS. Eplerenone, a mineralocorticoid receptor antagonist, attenuated the effects of HS on both ENaC activity and artery relaxation. CONCLUSIONS AND IMPLICATIONS These data suggest that HS diet blunts artery relaxation and causes hypertension via a pathway associated with aldosterone-dependent activation of ENaC in endothelial cells. This pathway provides one of the mechanisms by which HS causes hypertension in Dahl SS rats. LINKED ARTICLES This article is part of a themed section on Spotlight on Small Molecules in Cardiovascular Diseases. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.8/issuetoc.
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Affiliation(s)
- Zi-Rui Wang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Hui-Bin Liu
- Department of Clinical Pharmacy, Institute of Clinical Pharmacy, the 2nd Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Ying-Ying Sun
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Qing-Qing Hu
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Yu-Xia Li
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Wei-Wan Zheng
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Chang-Jiang Yu
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Xin-Yuan Li
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Ming-Ming Wu
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Bin-Lin Song
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Jian-Jun Mu
- Department of Cardiovascular Medicine, First Affiliated Hospital of Medical College of Xi'an Jiaotong University, Key Laboratory of Molecular Cardiology, Xi'an, China
| | - Zu-Yi Yuan
- Department of Cardiovascular Medicine, First Affiliated Hospital of Medical College of Xi'an Jiaotong University, Key Laboratory of Molecular Cardiology, Xi'an, China
| | - Zhi-Ren Zhang
- Departments of Cardiology and Clinical Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China.,Department of Clinical Pharmacy, Institute of Clinical Pharmacy, the 2nd Affiliated Hospital, Harbin Medical University, Harbin, China
| | - He-Ping Ma
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, USA
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Wu MM, Zhai YJ, Li YX, Hu QQ, Wang ZR, Wei SP, Zou L, Alli AA, Thai TL, Zhang ZR, Ma HP. Hydrogen peroxide suppresses TRPM4 trafficking to the apical membrane in mouse cortical collecting duct principal cells. Am J Physiol Renal Physiol 2016; 311:F1360-F1368. [PMID: 27956381 DOI: 10.1152/ajprenal.00439.2016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/31/2016] [Accepted: 10/31/2016] [Indexed: 01/14/2023] Open
Abstract
A Ca2+-activated nonselective cation channel (NSCCa) is found in principal cells of the mouse cortical collecting duct (CCD). However, the molecular identity of this channel remains unclear. We used mpkCCDc14 cells, a mouse CCD principal cell line, to determine whether NSCCa represents the transient receptor potential (TRP) channel, the melastatin subfamily 4 (TRPM4). A Ca2+-sensitive single-channel current was observed in inside-out patches excised from the apical membrane of mpkCCDc14 cells. Like TRPM4 channels found in other cell types, this channel has an equal permeability for Na+ and K+ and has a linear current-voltage relationship with a slope conductance of ~23 pS. The channel was inhibited by a specific TRPM4 inhibitor, 9-phenanthrol. Moreover, the frequency of observing this channel was dramatically decreased in TRPM4 knockdown mpkCCDc14 cells. Unlike those previously reported in other cell types, the TRPM4 in mpkCCDc14 cells was unable to be activated by hydrogen peroxide (H2O2). Conversely, after treatment with H2O2, TRPM4 density in the apical membrane of mpkCCDc14 cells was significantly decreased. The channel in intact cell-attached patches was activated by ionomycin (a Ca2+ ionophore), but not by ATP (a purinergic P2 receptor agonist). These data suggest that the NSCCa current previously described in CCD principal cells is actually carried through TRPM4 channels. However, the physiological role of this channel in the CCD remains to be further determined.
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Affiliation(s)
- Ming-Ming Wu
- Departments of Cardiology and Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Harbin, China; and.,Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Yu-Jia Zhai
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Yu-Xia Li
- Departments of Cardiology and Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Harbin, China; and
| | - Qing-Qing Hu
- Departments of Cardiology and Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Harbin, China; and
| | - Zhi-Rui Wang
- Departments of Cardiology and Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Harbin, China; and
| | - Shi-Peng Wei
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Li Zou
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Abdel A Alli
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Tiffany L Thai
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Zhi-Ren Zhang
- Departments of Cardiology and Clinic Pharmacy, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Harbin, China; and
| | - He-Ping Ma
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
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Wu MM, Chen T, Xiong W, Huang CJ, Shi ZQ, Pu HJ. [The role of PACAP protein in chronic sinusitis with or without nasal polyps]. Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi 2016; 30:1608-1611. [PMID: 29871155 DOI: 10.13201/j.issn.1001-1781.2016.20.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Indexed: 11/12/2022]
Abstract
Objective:To investigate the expression of PACAP protein in chronic rhinosinusitis without/with nasal polyps and refractory chronic rhinosinusitis.Method: Fifty-three patients with nasal polyps,70 cases with chronic sinusitis, 28 patients with refractory chronic rhinosinusitis and 20 control cases were enrolled for this study. The expression of PACAP protein was detected by immunochemistry.Result: ①PACAP protein were expressed in nasal epithelium,glandular epithelium and goblet cells;②The positive intensity of PACAP was" +", " +++", "--+",and " ++" in nasal polyps, chronic rhinosinusitis, refractory chronic rhinosinusitis, and control group, respectively.Conclusion:PACAP protein mainly locates in nasal epithelium,glandular epithelium and goblet cells. Reduced expression of PACAP may be related with onset of chronic rhiniosinusitis without/with nasal polyps.
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Affiliation(s)
- M M Wu
- Department of Otolaryngology,First Affiliated Hospital of Yunnan University of Traditional Chinese Medicine, Kunming,650021,China
| | - T Chen
- Department of Otolaryngology,First Affiliated Hospital of Yunnan University of Traditional Chinese Medicine, Kunming,650021,China
| | - W Xiong
- Department of Otolaryngology,First Affiliated Hospital of Yunnan University of Traditional Chinese Medicine, Kunming,650021,China
| | - C J Huang
- Yunnan Province Hospital of Traditional Chinese Medicine
| | - Z Q Shi
- Yunnan Province Hospital of Traditional Chinese Medicine
| | - H J Pu
- Yunnan Province Hospital of Traditional Chinese Medicine
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16
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Wang ZJ, Zhang YL, Zhong JP, Yao HH, Wang J, Wu MM, Meijerink A. One-step synthesis and luminescence properties of tetragonal double tungstates nanocrystals. Nanoscale 2016; 8:15486-15489. [PMID: 27524472 DOI: 10.1039/c6nr02715f] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A versatile one-step thermolysis protocol is demonstrated to produce a uniform dispersion of tetragonal double tungstates NaRE(WO4)2 (RE = rare earth) nanocrystals (NCs). Oriented attachment in the [001] direction occurred. Doping with luminescent RE(3+) ions resulted in highly luminescent NCs showing characteristic line emission of the dopant as well as a blue emission assigned to surface adsorbed organic species.
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Affiliation(s)
- Z J Wang
- MOE Laboratory of Bioinorganic and Synthetic Chemistry, KLGHEI of Environment and Energy Chemistry, State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China. and Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584 CC Utrecht, Netherlands
| | - Y L Zhang
- MOE Laboratory of Bioinorganic and Synthetic Chemistry, KLGHEI of Environment and Energy Chemistry, State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China.
| | - J P Zhong
- MOE Laboratory of Bioinorganic and Synthetic Chemistry, KLGHEI of Environment and Energy Chemistry, State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China.
| | - H H Yao
- MOE Laboratory of Bioinorganic and Synthetic Chemistry, KLGHEI of Environment and Energy Chemistry, State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China.
| | - J Wang
- MOE Laboratory of Bioinorganic and Synthetic Chemistry, KLGHEI of Environment and Energy Chemistry, State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China.
| | - M M Wu
- MOE Laboratory of Bioinorganic and Synthetic Chemistry, KLGHEI of Environment and Energy Chemistry, State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China.
| | - A Meijerink
- Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584 CC Utrecht, Netherlands
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Wu MM, Lou J, Song BL, Gong YF, Li YC, Yu CJ, Wang QS, Ma TX, Ma K, Hartzell HC, Duan DD, Zhao D, Zhang ZR. Hypoxia augments the calcium-activated chloride current carried by anoctamin-1 in cardiac vascular endothelial cells of neonatal mice. Br J Pharmacol 2016; 171:3680-92. [PMID: 24758567 PMCID: PMC4128065 DOI: 10.1111/bph.12730] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 04/01/2014] [Accepted: 04/06/2014] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND AND PURPOSE The molecular identity of calcium-activated chloride channels (CaCCs) in vascular endothelial cells remains unknown. This study sought to identify whether anoctamin-1 (Ano1, also known as TMEM16A) functions as a CaCC and whether hypoxia alters the biophysical properties of Ano1 in mouse cardiac vascular endothelial cells (CVECs). EXPERIMENTAL APPROACH Western blot, quantitative real-time PCR, confocal imaging analysis and patch-clamp analysis combined with pharmacological approaches were used to determine whether Ano1 was expressed and functioned as CaCC in CVECs. KEY RESULTS Ano1 was expressed in CVECs. The biophysical properties of the current generated in the CVECs, including the Ca2+ and voltage dependence, outward rectification, anion selectivity and the pharmacological profile, are similar to those described for CaCCs. The density of ICl(Ca) detected in CVECs was significantly inhibited by T16Ainh-A01, an Ano1 inhibitor, and a pore-targeting, specific anti-Ano1 antibody, and was markedly decreased in Ano1 gene knockdown CVECs. The density of ICl(Ca) was significantly potentiated in CVECs exposed to hypoxia, and this hypoxia-induced increase in the density of ICl(Ca) was inhibited by T16Ainh-A01 or anti-Ano1 antibody. Hypoxia also increased the current density of ICl(Ca) in Ano1 gene knockdown CVECs. CONCLUSIONS AND IMPLICATIONS Ano1 formed CaCC in CVECs of neonatal mice. Hypoxia enhances Ano1-mediated ICl(Ca) density via increasing its expression, altering the ratio of its splicing variants, sensitivity to membrane voltage and to Ca2+. Ano1 may play a role in the pathophysiological processes during ischaemia in heart, and therefore, Ano1 might be a potential therapeutic target to prevent ischaemic damage.
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Affiliation(s)
- Ming-Ming Wu
- Departments of Clinical Pharmacy and Cardiology, Institute of Clinical Pharmacy, The 2nd Affiliated Hospital, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin Medical University, Harbin, China
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Xiao H, Wu MM, Shao FY, Tan BE, Li TJ, Ren WK, Yin J, Wang J, He QH, Yin YL, Hou YQ. Metabolic profiles in the response to supplementation with composite antimicrobial peptides in piglets challenged with deoxynivalenol. J Anim Sci 2016; 93:1114-23. [PMID: 26020888 DOI: 10.2527/jas.2014-8229] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Deoxynivalenol (DON) causes various toxic effects in human and animals. However, our previous studies have shown that composite antimicrobial peptides (CAP) can have a protective effect in piglets challenged with DON. This study was conducted to evaluate the effect of the CAP GLAM 180# on the metabolism of piglets challenged with DON using a nuclear magnetic resonance (NMR)-based metabolomics approach. A total of 28 individually housed piglets (Duroc × Landrace × Large Yorkshire) weaned at 28 d of age were randomly assigned into 4 treatment groups (7 pigs/treatment) based on a 2 × 2 factorial arrangement that were fed, respectively, a basal diet (NC), basal diet + 0.4% CAP (basal + CAP), basal diet + 4 mg/kg DON (basal + DON), and basal diet + 4 mg/kg DON + 0.4% CAP (DON + CAP). A 7-d adaptation period was followed by 30 d of treatment. Blood samples were then collected for metabolite analysis by proton NMR (H-NMR) spectroscopy and liquid chromatography tandem mass spectrometry (LC-MS/MS). The combined results of H-NMR spectroscopy and LC-MS/MS showed that DON increased ( < 0.05) the serum concentrations of low-density lipoprotein, glycoprotein, urea, trimethylamine-N-oxide (TMAO), and lactate as well as those of almost all essential AA and some nonessential AA but decreased the concentrations of high-density lipoprotein (HDL), unsaturated lipids, citrate, choline, and fumarate compared with those in NC treatment ( < 0.05). There was a significant interaction effect ( < 0.05) of supplementation with DON and CAP on some metabolites showed that the serum concentrations of HDL, unsaturated lipids, Pro, citrate, and fumarate were greater ( < 0.05) whereas those of glycoprotein, urea, TMAO, Gly, and lactate were lower in the DON + CAP treatment compared with those in the basal + DON treatment ( < 0.05). These findings indicated that DON causes disturbances in AA, lipid, and energy metabolism and that CAP could partially attenuate the above metabolic disturbances induced by DON.
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Wang J, Li GR, Tan BE, Xiong X, Kong XF, Xiao DF, Xu LW, Wu MM, Huang B, Kim SW, Yin YL. Oral administration of putrescine and proline during the suckling period improves epithelial restitution after early weaning in piglets. J Anim Sci 2016; 93:1679-88. [PMID: 26020189 DOI: 10.2527/jas.2014-8230] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Polyamines are necessary for normal integrity and the restitution after injury of the gastrointestinal epithelium. The objective of this study was to investigate the effects of oral administration of putrescine and proline during the suckling period on epithelial restitution after early weaning in piglets. Eighteen neonatal piglets (Duroc × Landrace × Large Yorkshire) from 3 litters (6 piglets per litter) were assigned to 3 groups, representing oral administration with an equal volume of saline (control), putrescine (5 mg/kg BW), and proline (25 mg/kg BW) twice daily from d 1 to weaning at 14 d of age. Plasma and intestinal samples were obtained 3 d after weaning. The results showed that oral administration of putrescine or proline increased the final BW and ADG of piglets compared with the control (P < 0.05). Proline treatment decreased plasma D-lactate concentration but increased the villus height in the jejunum and ileum, as well as the percentage of proliferating cell nuclear antigen (PCNA) positive cells and alkaline phosphatase (AKP) activity in the jejunal mucosa (P < 0.05). The protein expressions for zonula occludens (ZO-1), occludin, and claudin-3 (P < 0.05) but not mRNA were increased in the jejunum of putrescine- and proline-treated piglets compared with those of control piglets. The voltage-gated K+ channel (Kv) 1.1 protein expression in the jejunum of piglets administrated with putrescine and the Kv1.5 mRNA and Kv1.1 protein levels in the ileum of piglets administrated with proline were greater than those in control piglets (P < 0.05). These findings indicate that polyamine or its precursor could improve mucosal proliferation, intestinal morphology, as well as tight junction and potassium channel protein expressions in early-weaned piglets, with implications for epithelial restitution and barrier function after stress injury.
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Ye Z, Wu MM, Wang CY, Li YC, Yu CJ, Gong YF, Zhang J, Wang QS, Song BL, Yu K, Hartzell HC, Duan DD, Zhao D, Zhang ZR. Characterization of Cardiac Anoctamin1 Ca²⁺-Activated Chloride Channels and Functional Role in Ischemia-Induced Arrhythmias. J Cell Physiol 2015; 230:337-46. [PMID: 24962810 DOI: 10.1002/jcp.24709] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 06/20/2014] [Indexed: 12/17/2022]
Abstract
Anoctamin1 (ANO1) encodes a Ca(2+)-activated chloride (Cl(-)) channel (CaCC) in variety tissues of many species. Whether ANO1 expresses and functions as a CaCC in cardiomyocytes remain unknown. The objective of this study is to characterize the molecular and functional expression of ANO1 in cardiac myocytes and the role of ANO1-encoded CaCCs in ischemia-induced arrhythmias in the heart. Quantitative real-time RT-PCR, immunofluorescence staining assays, and immunohistochemistry identified the molecular expression, location, and distribution of ANO1 in mouse ventricular myocytes (mVMs). Patch-clamp recordings combined with pharmacological analyses found that ANO1 was responsible for a Ca(2+)-activated Cl(-) current (I(Cl.Ca)) in cardiomyocytes. Myocardial ischemia led to a significant increase in the current density of I(Cl.Ca), which was inhibited by a specific ANO1 inhibitor, T16A(inh)-A01, and an antibody targeting at the pore area of ANO1. Moreover, cardiomyocytes isolated from mice with ischemia-induced arrhythmias had an accelerated early phase 1 repolarization of action potentials (APs) and a deeper "spike and dome" compared to control cardiomyocytes from non-ischemia mice. Application of the antibody targeting at ANO1 pore prevented the ischemia-induced early phase 1 repolarization acceleration and caused a much shallower "spike and dome". We conclude that ANO1 encodes CaCC and plays a significant role in the phase 1 repolarization of APs in mVMs. The ischemia-induced increase in ANO1 expression may be responsible for the increased density of I(Cl.Ca) in the ischemic heart and may contribute, at least in part, to ischemia-induced arrhythmias.
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Affiliation(s)
- Zhen Ye
- Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Ming-Ming Wu
- Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Chun-Yu Wang
- Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Yan-Chao Li
- Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Chang-Jiang Yu
- Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Yuan-Feng Gong
- Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Jun Zhang
- Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Qiu-Shi Wang
- Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Bin-Lin Song
- Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Kuai Yu
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia
| | - H Criss Hartzell
- Department of Cell Biology, Emory University School of Medicine, Atlanta, Georgia
| | - Dayue Darrel Duan
- Laboratory of Cardiovascular Phenomics, Department of Pharmacology, Center for Molecular Medicine, School of Medicine University of Nevada, Reno, Nevada
| | - Dan Zhao
- Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
| | - Zhi-Ren Zhang
- Departments of Clinical Pharmacy and Cardiology, The 2nd Affiliated Hospital, Harbin Medical University, Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, P. R. China
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Duan JL, Yin J, Ren WK, Wu MM, Chen S, Cui ZJ, Wu X, Huang RL, Li TJ, Yin YL. Pyrrolidine dithiocarbamate restores gastric damages and suppressive autophagy induced by hydrogen peroxide. Free Radic Res 2015; 49:210-8. [PMID: 25471085 DOI: 10.3109/10715762.2014.993627] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
It is well known that gastric barrier is very important for protecting host from various insults. Simultaneously, autophagy serving as a prominent cytoprotective and survival pathway under oxidative stress conditions is being increasingly recognized. Thus, this study was conducted for investigating the effect of pyrrolidine dithiocarbamate (PDTC) on gastric barrier function and autophagy under oxidative stress induced by intragastric administration of hydrogen peroxide (H2O2). The gastric tight junction proteins [zonula occludens-1 (ZO1), occludin, and claudin1], autophagic proteins [microtubule-associated protein light chain 3I(LC3I), LC3II, and beclin1], and nuclear factor kappa B (NF-κB) signaling pathway (p65 and IκB kinase α/β) were determined by Western blot. The results showed that H2O2 exposure disturbed gastric barrier function with decreased expression of ZO1, occludin, and claudin1, and reduced gastric autophagy with decreased conversion of LC3I into LC3II in mice. However, treatment with PDTC restored these adverse effects evidenced by increased expression of ZO1 and claudin1 and increased conversion of LC3I into LC3II. Meanwhile, H2O2 exposure decreased normal human gastric epithelial mucosa cell line (GES-1) viability in a concentration-dependent way. However, after being exposed to H2O2, GES-1 exhibited autophagic response which was inconsistent with our in vivo results in mice, while PDTC failed to decrease autophagy in GES-1 induced by H2O2. Simultaneously, the beneficial effect of PDTC on gastric damage and autophagy in mice might be independent of inhibition of NF-κB. In conclusion, PDTC treatment restores gastric damages and reduced autophagy induced by H2O2. Therefore, PDTC may serve as a potential adjuvant therapy for gastric damages.
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Affiliation(s)
- J L Duan
- Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences , Changsha, Hunan , P. R. China
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Xiao J, Wu QL, Liu P, Liang Y, Li HB, Wu MM, Yang GW. Highly stable sub-5 nm Sn₆O₄(OH)₄ nanocrystals with ultrahigh activity as advanced photocatalytic materials for photodegradation of methyl orange. Nanotechnology 2014; 25:135702. [PMID: 24583803 DOI: 10.1088/0957-4484/25/13/135702] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Among numerous active photocatalytic materials, Sn-based oxide nanomaterials are promising photocatalytic materials in environmental protection measures such as water remediation due to their excellent physicochemical property. Research on photocatalytic nanomaterials for photodegradation of methyl orange (MO) so far has focused on TiO₂-based nanostructures; e.g., TiO₂-P25 is recognized to be the best commercial photocatalyst to date, rather than Sn-based oxide nanomaterials, in spite of their impressive acid- and alkali-resistant properties and high stability. Here, we demonstrate very high photocatalytic activity of highly stable sub-5 nm hydromarchite (Sn₆O₄(OH)₄) nanocrystals synthesized by a simple and environmentally friendly laser-based technique. These Sn₆O₄(OH)₄ nanocrystals exhibit ultrahigh photocatalytic performance for photodegradation of MO and their degradation efficiency is far superior to that of TiO₂-P25. The detailed investigations demonstrated that the great photocatalytic activity results from the ultrafine size and unique surface activity induced by the laser-based technique. Mass production of reactive species of hydroxyl radicals was detected in the experiments due to the appropriate bandgap of Sn₆O₄(OH)₄ nanocrystals. These findings actually open a door to applications of Sn-based oxide nanomaterials as advanced photocatalytic materials.
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Affiliation(s)
- J Xiao
- State Key Laboratory of Optoelectronic Materials and Technologies, Institute of Optoelectronic and Functional Composite Materials, Nanotechnology Research Center, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275, Guangdong, People's Republic of China
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Yang ZL, Cheng K, Sun HG, Zou WW, Wu MM. Changes in peripheral blood Th1 and Th2 cells in rat liver transplantation under different immune statuses. Genet Mol Res 2013; 12:6939-46. [PMID: 24391042 DOI: 10.4238/2013.december.19.13] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In this study, early expressions of peripheral blood Th1 and Th2 cells were documented following rat liver transplantation and related to immune status. Rats were divided into 3 groups: group A (control): syngeneic transplantation (Brown Norway (BN) → BN); group B: allogeneic transplantation + cyclosporine A (CsA); group C: allogeneic transplantation (Lewis → BN). Flow cytometry was used to analyze peripheral blood CD4(+)CD45RC percentage on days 1, 3, 5, 7, and 14 following transplantation, and were compared to graft rejection pathological grades and receptor survival times. The average survival of groups A and B exceeded 100 days, which was significantly longer than that of group C (3.56 ± 34.3 days). With the exception of the first day, rejection grades were significantly higher in groups C and B compared to group A, and group C rejection grades were significantly higher than those of group B. Three days after transplantation, the CD4(+)CD45RC(+) to CD4(+)CD45RC(-) ratio of group C was significantly higher than that of groups A and B. In group B, the CD4(+)CD45RC(+) to CD4(+)CD45RC(-) ratio was negatively correlated to the rejection grade (r = -0.565, P < 0.01), whereas this relationship was positive in group C (r = 0.745, P < 0.01). In conclusion, peripheral blood Th1 was highly expressed during rejection in rat liver grafts. Peripheral blood Th2 tended to increase early under rejection inhibition with CsA, and its high expression level may correlate with long-term acceptance or tolerance of transplanted livers.
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Affiliation(s)
- Z-L Yang
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Binzhou Medical College, Shandong Binzhou, China
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Xiao H, Wu MM, Tan BE, Yin YL, Li TJ, Xiao DF, Li L. Effects of composite antimicrobial peptides in weanling piglets challenged with deoxynivalenol: I. Growth performance, immune function, and antioxidation capacity. J Anim Sci 2013; 91:4772-80. [PMID: 23965387 DOI: 10.2527/jas.2013-6426] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The mycotoxin deoxynivalenol (DON) is a food contaminant that leads to reduced feed intake and reduced BW gain, as well as organ impairment. On the other hand, antimicrobial peptides have been shown to have positive effects on growth performance, nutrient digestibility, and immune function. The purpose of this study was to investigate the protective effects of composite antimicrobial peptides (CAP) on piglets challenged with DON. After a 7-d adaptation period, 28 individually housed piglets (Duroc × Landrace × Large Yorkshire) weaned at 28 d of age were randomly assigned to receive 1 of 4 treatments (7 pigs/treatment): negative control, basal diet (NC), basal diet + 0.4% CAP (CAP), basal diet + 4 mg/kg DON (DON), and basal diet + 4 ppm DON + 0.4% CAP (DON + CAP). On d 15 and 30 after the initiation of treatment, blood samples were collected for the determination of blood profile. Piglets were monitored for 30 d to assess performance and then were slaughtered to obtain organs for the determination of the relative weight of organs. The results showed that dietary supplementation with DON decreased (P < 0.05) ADFI, ADG, and G:F, whereas dietary supplementation with CAP improved ADG and G:F (P < 0.05). The relative weight of the kidney and pancreas was greater and the relative weight of the spleen was lighter in the DON treatment than in the other 3 treatments (P < 0.05). There were no effects (P > 0.05) on other relative weights of viscera, except the relative weight of the gallbladder, but the diamine oxidase activity in the liver decreased in DON-treated piglets (P < 0.05). Piglets in the DON treatment had increased serum concentrations of alkaline phosphatase, alanine transaminase, and aspartate aminotransferase and a dramatic decrease in total protein (P < 0.05), whereas there were no differences (P > 0.05) between the DON + CAP treatment and the other treatments. The DON treatment decreased the numbers of red blood cells and platelets, as well as the serum catalase concentrations, and decreased the serum concentrations of H2O2, maleic dialdehyde, and nitric oxide (P < 0.05). The numbers of platelets and thrombocytocrit, as well as the serum concentrations of catalase, were greater, whereas the maleic dialdehyde concentrations were decreased, in both the CAP and DON + CAP treatments compared with the other treatments (P < 0.05). Compared with the control treatment, DON decreased peripheral lymphocyte proliferation on d 15, whereas supplementation with CAP increased it on d 15 and 30 (P < 0.05). These findings indicate that CAP could improve feed efficiency, immune function, and antioxidation capacity and alleviate organ damage, and thus, it has a protective effect in piglets challenged with DON.
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Affiliation(s)
- H Xiao
- Observation and Experiment Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan 410125, China
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Xiao H, Tan BE, Wu MM, Yin YL, Li TJ, Yuan DX, Li L. Effects of composite antimicrobial peptides in weanling piglets challenged with deoxynivalenol: II. Intestinal morphology and function. J Anim Sci 2013; 91:4750-6. [PMID: 23965392 DOI: 10.2527/jas.2013-6427] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Deoxynivalenol (DON) affects animal and human health and targets the gastrointestinal tract. The objective of this study was to evaluate the ability of composite antimicrobial peptides (CAP) to repair intestinal injury in piglets challenged with DON. A total of 28 piglets (Duroc × Landrace × Large Yorkshire) weaned at 28 d of age were randomly assigned to receive 1 of 4 treatments (7 pigs/treatment): negative control, basal diet (NC), basal diet + 0.4% composite antimicrobial peptide (CAP), basal diet + 4 mg/kg DON (DON), and basal diet + 4 mg/kg DON + 0.4% CAP (DON + CAP). After an adaptation period of 7 d, blood samples were collected on d 15 and 30 after the initiation of treatment for determinations of the concentrations of D-lactate and diamine oxidase. At the end of the study, all piglets were slaughtered to obtain small intestines for the determination of intestinal morphology, epithelial cell proliferation, and protein expression in the mammalian target of rapamycin (mTOR) signaling pathway. The results showed that DON increased serum concentrations of D-lactate and diamine oxidase, and these values in the CAP and DON + CAP treatments were less than those in the NC and DON treatments, respectively (P < 0.05). The villous height/crypt depth in the jejunum and ileum and the goblet cell number in the ileum in the CAP and DON + CAP treatments were greater than those in the NC and DON treatments (P < 0.05). The proliferating cell nuclear antigen (PCNA) labeling indexes for the jejunum and ileum in the DON + CAP treatment were greater than those in the DON treatment (P < 0.05). The DON decreased (P < 0.05) the relative protein expression of phosphorylated Akt (Protein Kinase B) and mTOR in the jejunal and ileal mucosa and of phosphorylated 4E-binding protein 1 (p-4EBP1) in the jejunal mucosa, whereas CAP increased (P < 0.05) the protein expression of p-4EBP1 in the jejunum. These findings showed that DON could enhance intestinal permeability, damage villi, cause epithelial cell apoptosis, and inhibit protein synthesis, whereas CAP improved intestinal morphology and promoted intestinal epithelial cell proliferation and protein synthesis, indicating that CAP may repair the intestinal injury induced by DON.
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Affiliation(s)
- H Xiao
- Observation and Experiment Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture; Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production; Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences; Changsha, Hunan 410125, China
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Duan XH, He XH, Cui PC, Wang XY, Wu MM, Shi JB, Xu G, Jiang X. [Preliminary study of primarily cultured C57 articular cartilage transfected with plasmid IDO-EGFP by lipofectamine]. Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi 2007; 23:1110-1112. [PMID: 18062878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
AIM To determine the transfection efficiency and transient expression of pIDO-EGFP gene in primarily cultured C57 articular cartilage of mice, and to establish a transfection method of the primarily cultured articular cartilage in mice. METHODS Plasmid IDO-EGFP was amplified in Escherichia coli. The primarily cultured mouse chondrocytes which were initially obtained from articular cartilage were cultured in vitro and transfected with pIDO-EGFP by lipofectamine2000 reagent under optimized condition. Transfection process and transient expression were evaluated by fluorescent microscopy and laser scanning confocal microscopy (LSCM), and transfection efficiency was determined by flow cytometry. RESULTS There was obvious expression of EGFP at 24 h after transfection. The transfection efficiency of pIDO-EGFP into primarily cultured mouse chondrocytes reached 36.43% at 48 hours and the transfection did not affect the process of cell adherence. CONCLUSION IDO gene has been successfully transfected into primarily cultured chondrocytes by means of lipofectamine2000 reagent and the chondrocytes can survive in vitro. Satisfactory efficiency of transient transfection can be reached under optimized condition, which will provide a basis for gene introduction and modification of tissue engineered cartilage.
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Affiliation(s)
- Xiao-Hong Duan
- Department of Otolaryngology, Tangdu Hospital, Fourth Military Medical University, Xi'an 710038, China.
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Liu H, Wu MM, Zakon HH. Individual variation and hormonal modulation of a sodium channel β subunit in the electric organ correlate with variation in a social signal. Dev Neurobiol 2007; 67:1289-304. [PMID: 17638382 DOI: 10.1002/dneu.20404] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The sodium channel beta1 subunit affects sodium channel gating and surface density, but little is known about the factors that regulate beta1 expression or its participation in the fine control of cellular excitability. In this study we examined whether graded expression of the beta1 subunit contributes to the gradient in sodium current inactivation, which is tightly controlled and directly related to a social behavior, the electric organ discharge (EOD), in a weakly electric fish Sternopygus macrurus. We found the mRNA and protein levels of beta1 in the electric organ both correlate with EOD frequency. We identified a novel mRNA splice form of this gene and found the splicing preference for this novel splice form also correlates with EOD frequency. Androgen implants lowered EOD frequency and decreased the beta1 mRNA level but did not affect splicing. Coexpression of each splice form in Xenopus oocytes with either the human muscle sodium channel gene, hNav1.4, or a Sternopygus ortholog, smNav1.4b, sped the rate of inactivation of the sodium current and shifted the steady-state inactivation toward less negative membrane potentials. The translational product of the novel mRNA splice form lacks a previously identified important tyrosine residue but still functions normally. The properties of the fish alpha and coexpressed beta1 subunits in the oocyte replicate those of the electric organ's endogenous sodium current. These data highlight the role of ion channel beta subunits in regulating cellular excitability.
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Affiliation(s)
- He Liu
- Section of Neurobiology and the Institute of Neuroscience, University of Texas at Austin, Austin, Texas 78712, USA
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Abstract
The case of a patient with surgically proven internal herniation of a loop of ileum through the sigmoid mesocolon is described. This 66-year-old man presented clinically with acute lower abdominal pain and an elevated white blood cell count. A computed tomography (CT) scan showed a thickened bowel loop with "bird-beak" appearance in the pelvis, centered towards the medial side and lying aside the effaced sigmoid colon. We think this CT picture is highly suggestive of internal herniation of the ileum through the sigmoid mesocolon, which is a rare clinical entity.
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Affiliation(s)
- Ming-Shiang Yang
- Department of Diagnostic Radiology, Chung-Shan Medical University Hospital, Taichung, Taiwan, ROC
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Abstract
Activation of K(+) current plays a critical role in the control of programmed cell death. In the present study, whole-cell patch-clamp recording, a caspase-3 activity assay, and flow cytometric analysis were used to examine the effects of the MT2 melatonin receptor agonist 2-iodomelatonin on the delayed-rectifier K(+) current (IK) and the prevention of apoptosis. It was found that apoptosis of cerebellar granular neurons induced by low-K(+) (5 mm) incubation was associated with an increase in IK amplitude and caspase-3 activity. After 6 hr of low-K(+) treatment, IK was increased by 45% (n = 86). Flow cytometry showed that the apoptosis rate increased by 333% compared with the control neurons. In addition, exposure of cultured granule cells to low K(+) also resulted in a significant activation of caspase-3, by 466%. 2-Iodomelatonin (10 microm in injection pipette) inhibited the IK amplitude recorded from control cells and from cells undergoing apoptosis. However, 2-iodomelatonin only modified the IK-channel activation kinetics of cells under both conditions. Furthermore, 2-iodomelatonin reduced the rate of apoptosis and caspase-3 activation, by 66 and 64%, respectively. The melatonin receptor antagonist, 4P-PDOT, abrogated the effect of 2-iodomelatonin on the IK augmentation, caspase-3 activity, and apoptosis. These results suggest that the neuroprotective effects of melatonin are not only because of its function as a powerful antioxidant, but also to its interactions with specific receptors. The effect of 2-iodomelatonin against apoptosis may be mediated by activating a melatonin receptor, which modulates IK channels and reduces K(+) efflux.
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Affiliation(s)
- Song Jiao
- Center for Brain Science Research, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai, China
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Li ZB, Liu XW, Xu NS, Deng SZ, Chen J, Wu MM, Ren S, Chen J, Zhao FL. Resonant field emission through amorphous diamond thin films (a model study). Ultramicroscopy 2003; 95:75-80. [PMID: 12535547 DOI: 10.1016/s0304-3991(02)00299-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A model for field emission through an amorphous diamond thin film with defects is constructed. Theoretical study shows that the emission is enhanced by attractive defects which would make the resonant emission observable for films with thickness of about 10nm. The emitted current density in typical parameters is calculated as functions of thickness, field strength and defect density. The energy distribution of emitted electrons is attained.
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Affiliation(s)
- Z B Li
- Guangdong Province Key Lab of Display Material and Technology, Institute of Condensed Matter Physics, Zhongshan University, 510275, Guangzhou, People's Republic of China
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Abstract
Production and secretion of hormones by the pituitary involve highly orchestrated intracellular transport and sorting steps. Hormone precursors are routed through a series of compartments before being packaged in secretory granules. These highly dynamic carriers play crucial roles in both prohormone processing and peptide exocytosis. We have employed the ACTH-secreting AtT-20 cell line to study the membrane sorting events that confer functionality (prohormone activation and regulated exocytosis) to these secretory carriers. The unique ability of granules to promote prohormone processing is attributed to their acidic interior. Using a novel avidin-targeted fluorescence ratio imaging technique, we have found that the trans-Golgi of live AtT-20 cells maintains a mildly acidic (approximately pH 6.2) interior. Budding of secretory granules causes the lumen to acidify to <pH 6.0, which is both necessary and sufficient to trigger SPC3-mediated proteolytic conversion of proopiomelanocortin to ACTH. Investigation of the pH regulatory mechanism indicates that the trans-Golgi and secretory granules maintain different pH values by distinct sorting of key membrane transporters. Mathematical modeling of our data suggests that the decreasing pH values of organelles of the regulated secretory pathway is established by gradually increasing the density of active H+ pumps from the ER to Golgi while concomitantly decreasing the H+ permeability from ER to Golgi to secretory granules. An in vitro assay was developed to study the formation of processing-competent secretory granules from their processing-incompetent precursor trans-Golgi compartment. Our data suggest that ARF1-mediated sorting of proton pumps and leaks during early stages of granule formation confers processing competency to the resulting organelle. Once formed, these young granules continue to undergo membrane remodeling which results in dynamic changes in their exocytotic behavior. Two SNAREs, VAMP4 and synaptotagmin IV, enter newly formed granules but are removed from the maturing granule membrane by vesicle budding. Sorting of these proteins is correlated with the acquisition of Ca2+-triggered exocytosis and a decrease in unregulated exocytotic rate. Thus, biosynthesis and secretion of pituitary hormones are dynamically regulated by intracellular sorting events that govern the functions of their secretory carriers.
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Affiliation(s)
- H-P H Moore
- Department of Molecular and Cell Biology, University of California, Berkeley 94720-3200, USA.
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Wu MM. [The developmental process of the 12-channel theory as viewed from Inner Canon of Yellow Emperor] (Chi). Zhonghua Yi Shi Za Zhi 2001; 22:240-3. [PMID: 11612976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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Wu MM, Chiou HY, Wang TW, Hsueh YM, Wang IH, Chen CJ, Lee TC. Association of blood arsenic levels with increased reactive oxidants and decreased antioxidant capacity in a human population of northeastern Taiwan. Environ Health Perspect 2001; 109:1011-7. [PMID: 11675266 PMCID: PMC1242077 DOI: 10.1289/ehp.011091011] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Arsenic is a notorious environmental toxicant known as both a carcinogen and an atherogen in human beings, but the pathogenic mechanisms are not completely understood. In cell culture studies, trivalent arsenic enhanced oxidative stress in a variety of mammalian cells, and this association may be closely associated with the development of arsenic-related diseases. To investigate the effect of arsenic exposure on oxidative stress in humans, we conducted a population study to determine the relationships of blood arsenic to reactive oxidants and antioxidant capacity at the individual level. We recruited 64 study subjects ages 42-75 years from residents of the Lanyang Basin on the northeast coast of Taiwan, where arsenic content in well water varies from 0 to > or = 3,000 microg/L. We used a chemiluminescence method, with lucigenin as an amplifier for measuring superoxide, to measure the plasma level of reactive oxidants. We used the azino-diethyl-benzthiazoline sulphate method to determine the antioxidant capacity level in plasma of each study subject. We determined arsenic concentration in whole blood by hydride formation with an atomic absorption spectrophotometer. The average arsenic concentration in whole blood of study subjects was 9.60 +/- 9.96 microg/L (+/- SD) with a range from 0 to 46.50 microg/L. The level of arsenic concentration in whole blood of study subjects showed a positive association with the level of reactive oxidants in plasma (r = +0.41, p = 0.001) and an inverse relationship with the level of plasma antioxidant capacity (r = -0.30, p = 0.014). However, we found no significant association (p = 0.266) between levels of plasma reactive oxidants and antioxidant capacity. Our results also show that the lower the primary arsenic methylation capability, the lower the level of plasma antioxidant capacity (p = 0.029). These results suggest that ingestion of arsenic-contaminated well water may cause deleterious effects by increasing the level of reactive oxidants and decreasing the level of antioxidant capacity in plasma of individuals. Persistent oxidative stress in peripheral blood may be a mechanism underlying the carcinogenesis and atherosclerosis induced by long-term arsenic exposure.
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Affiliation(s)
- M M Wu
- Institute of Biomedical Sciences, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan, Republic of China
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Abstract
A precise pH gradient between organelles of the regulated secretory pathway is required for sorting and processing of prohormones. We studied pH regulation in live endocrine cells by targeting biotin-based pH indicators to cellular organelles expressing avidin-chimera proteins. In AtT-20 cells, we found that steady-state pH decreased from the endoplasmic reticulum (ER) (pH(ER) = 7.4 +/- 0.2, mean +/- S.D.) to Golgi (pH(G) = 6.2 +/- 0.4) to mature secretory granules (MSGs) (pH(MSG) = 5.5 +/- 0.4). Golgi and MSGs required active H(+) v-ATPases for acidification. ER, Golgi, and MSG steady-state pH values were also dependent upon the different H(+) leak rates across each membrane. However, neither steady-state pH(MSG) nor rates of passive H(+) leak were affected by Cl(-)-free solutions or valinomycin, indicating that MSG membrane potential was small and not a determinant of pH(MSG). Therefore, our data do not support earlier suggestions that organelle acidification is primarily regulated by Cl(-) conductances. Measurements of H(+) leak rates, buffer capacities, and estimates of surface areas and volumes of these organelles were applied to a mathematical model to determine the H(+) permeability (P(H+)) of each organelle membrane. We found that P(H+) decreased progressively from ER to Golgi to MSGs, and proper acidification of Golgi and MSGs required gradual decreases in P(H+) and successive increases in the active H(+) pump density.
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Affiliation(s)
- M M Wu
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720-3200, USA
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Harper DS, Brogdon CL, Wu MM, Epelle U. A rapid method for evaluating microbicidal activity of dentifrice formulations against salivary bacteria ex vivo. J Clin Dent 2001; 11:89-93. [PMID: 11460277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
A new rapid ex vivo method was developed for evaluating the short-term bactericidal activity of dentifrices against salivary microorganisms. Dentifrice aliquots of 0.25 or 1.0 g were rapidly dispersed into 3.5 mL of freshly pooled human saliva, and 1.0 mL aliquots of the dentifrice-saliva suspension were collected after 30 or 60 seconds of exposure, diluted in neutralizing broth and plated on non-selective agar media for enumeration of surviving total cultivable microflora. Eight experimental dentifrices containing increasing amounts (0 to 2.6%) of a fixed ratio of essential oils (thymol, menthol, methyl salicylate and eucalyptol) were dispersed in saliva at a 0.25:3.5 (w/v) dentifrice:saliva ratio. Recoverable CFUs/mL at 30 sec. were reduced in a dose-responsive manner from > 10(6) to < 10(4). Additional tests using both 0.25 and 1.0 g amounts of dentifrice prototypes containing 2.1% of the essential oil mixture showed that the experimental dentifrices exhibited highly significant (approximately 2.5 log) reductions in viable recoverable microorganisms relative to essential oil-free placebos after both 30- and 60-second exposures. When compared to in vitro models previously used to evaluate the antimicrobial activity of dentifrices, this method provides a rapid, reproducible, more biologically representative means of screening dentifrice formulations for microbicidal activity using dilutions and exposure times approximating those achieved during toothbrushing. However, since other factors may influence microbicidal activity of dentifrice formulations in vivo, conclusions drawn using this model require clinical confirmation.
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Affiliation(s)
- D S Harper
- Oral Care Technology Development, Pfizer, Inc., Morris Plains, New Jersey, USA.
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Ko GT, Wu MM, Tang J, Wai HP, Chan CH, Chen R. Body mass index profile in Hong Kong Chinese adults. Ann Acad Med Singap 2001; 30:393-6. [PMID: 11503547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
INTRODUCTION Obesity has now become an epidemic with increasing prevalence in most parts of the world. However, information on the problem of obesity in Asians is limited. SUBJECTS AND METHODS From April 1996 to August 1997, 17,121 Chinese adult subjects from the community of Hong Kong presented themselves voluntarily at the United Christian Nethersole Community Health Service Centers for primary health care check-up. Demographic data including height and weight were documented. Their body mass indexes (BMI) were measured. The prevalence rates of overweight and obese subjects were calculated according to the 1995 World Health Organization criteria. RESULTS There were 4781 (27.9%) men and 12,340 (72.1%) women. The mean age (+/- SD) was 51.3 +/- 16.0 years (range 20 to 96 years, median 49.8 years). Of the 17,121 subjects, 4939 (28.85%) were overweight and 656 (3.83%) were obese. Based on the 1997 Hong Kong Census statistics of the overall Hong Kong population data, the age-standardised prevalence rates of overweight and obese subjects were 30.52% and 3.19% in men and 22.14% and 3.35% in women, respectively. Of the 10,937 subjects of working age (20 to 65 years), the prevalence rates of overweight and obese subjects were 28.98% and 3.55%, respectively. Of the 6648 subjects aged > or = 60 years, the prevalence rates of overweight and obese subjects were 36.31% and 4.81%, respectively. CONCLUSIONS In Hong Kong, the age-standardised prevalence rate of overweight and obese subjects were 30.5% and 3.2% in men and 22.1% and 3.4% in women, respectively. This information provides some useful estimations of the extent of an important public health problem, obesity, in Hong Kong.
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Affiliation(s)
- G T Ko
- Alice Ho Miu Ling Nethersole Hospital, 11 Chuen On Road, Tai Po, Hong Kong, SAR China.
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Wu MM, Llopis J, Adams SR, McCaffery JM, Teter K, Kulomaa MS, Machen TE, Moore HP, Tsien RY. Studying organelle physiology with fusion protein-targeted avidin and fluorescent biotin conjugates. Methods Enzymol 2001; 327:546-64. [PMID: 11045008 DOI: 10.1016/s0076-6879(00)27301-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Affiliation(s)
- M M Wu
- Department of Molecular and Cell Biology, University of California at Berkeley 94720, USA
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Ko GT, Tang J, Chan JC, Sung R, Wu MM, Wai HP, Chen R. Lower BMI cut-off value to define obesity in Hong Kong Chinese: an analysis based on body fat assessment by bioelectrical impedance. Br J Nutr 2001; 85:239-42. [PMID: 11242492 DOI: 10.1079/bjn2000251] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
There is increasing evidence suggesting that the cut-off values for defining obesity used in the Western countries cannot be readily applied to Asians, who often have smaller body frames than Caucasians. We examined the BMI and body fat (BF) as measured by bioelectrical impedance in 5153 Hong Kong Chinese subjects. We aimed to assess the optimal BMI reflecting obesity as defined by abnormal BF in Hong Kong Chinese. Receiver operating characteristic curve (ROC) analysis was used to assess the optimal BMI predicting BF at different levels. The mean age and SD of the 5153 subjects (3734 women and 1419 men) was 51.5 (SD 16.3) years (range: 18.0-89.5 years, median: 50.7 years). Age-adjusted partial correlation (r) between BMI and BF in women and men were 0.899 (P < 0.001) and 0.818 (P < 0.001) respectively. Using ROC analysis, the BMI corresponding to the conventional upper limit of normal BF was 22.5-23.1 kg/m(2), and the BMI corresponding to the 90 percentiles of BF was 25.4-26.1 kg/m(2). Despite similar body fat contents, the BMI cut-off value used to define obesity in Hong Kong Chinese should be lower as compared to Caucasians. We suggest a BMI of 23 kg/m(2) and 26 kg/m(2) as the cut-off values to define overweight and obesity respectively in Hong Kong Chinese.
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Affiliation(s)
- G T Ko
- Department of Medicine, Alice Ho Miu Ling Nethersole Hospital, 11, Chuen On Road, Tai Po, Hong Kong.
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Wei H, Mei YA, Wu MM, Sun JT, Zhou HQ, Zhang ZH. Swelling-activated chloride currents in embryonic chick heart cells. Acta Pharmacol Sin 2000; 21:986-90. [PMID: 11501066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
AIM To characterize a swelling-activated chloride current, I(Cl, swell), in white Leghorn chick heart cells and the effects of chlorpromazine (CPZ) effects. METHODS The patch-clamp technique in the whole-cell configuration was used. RESULTS Hyposmotic swelling elicited I(Cl, swell) in white Leghorn chick heart cells. The current amplitude increased from (452 +/- 200) pA to (849 +/- 373) pA with a reduction of osmolarity from 300 mmol.L-1 to 270 mmol.L-1, 4',4-Diisothiocyanostilbene-2,2'-disulphonic acid (DIDS) 100 mumol.L-1 decreased I(Cl, swell) from (1196 +/- 505) pA to (830 +/- 328) pA in hyposmotic solution. In white Leghorn chick heart cells I(Cl, swell) was not induced by CPZ 30 mumol.L-1, which is different from the case of E coli spheroplast. CONCLUSION Swelling-activated chloride current was activated by hyposmotic swelling in white Leghorn chick heart cells. The mechanism for activating the current is different from that of mechanosensitive ion channels of E coli.
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Affiliation(s)
- H Wei
- Department of Physiology and Biophysics, Liren Laboratory, Fudan University, Shanghai 200433, China
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Santos SL, Conforti N, Mankodi S, Kohut BE, Yu D, Wu MM, Parikh R. Anticalculus effect of two zinc citrate/essential oil-containing dentifrices. Am J Dent 2000; 13:11C-13C. [PMID: 11763907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
PURPOSE To assess the feasibility of incorporating zinc citrate, a known anticalculus ingredient, into a dentifrice formulation containing a fixed combination of essential oils, a known antiplaque/antigingivitis agent. MATERIALS AND METHODS This randomized, parallel, double-blind study evaluated the potential of two essential oil dentifrice formulations containing different levels of zinc citrate (1.0% and 2.0% ZCT) to reduce supragingival calculus formation compared to a marketed control dentifrice, Crest Regular. Following a 3-month pre-test phase, subjects received a dental prophylaxis, were stratified into three balanced groups on the basis of Volpe-Manhold calculus scores and brushed twice daily with their assigned dentifrice for 3 months. RESULTS One hundred ninety-six evaluable subjects completed all phases of the study. ANCOVA revealed that the 1.0% ZCT and 2.0% ZCT essential oil dentifrice formulations provided significant reductions in calculus formation of 26.4% and 29.0% (P< 0.001), respectively, compared to the control dentifrice, Crest Regular. The magnitude of calculus reductions is similar to those levels obtained by other zinc salt formulations.
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Affiliation(s)
- S L Santos
- The Warner-Lambert Consumer Healthcare Division of the Warner-Lambert Consumer Group of Pfizer, Morris Plains, NJ, USA.
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Coelho J, Kohut BE, Mankodi S, Parikh R, Wu MM. Essential oils in an antiplaque and antigingivitis dentifrice: a 6-month study. Am J Dent 2000; 13:5C-10C. [PMID: 11763912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
PURPOSE To determine if a dentifrice formulated with the fixed combination of essential oils possessed antiplaque and antigingivitis properties. MATERIALS AND METHODS This study was a blinded, randomized, controlled clinical trial. The 6-month study had clinical examinations at baseline, 3 and 6 months. The examinations consisted of three indices; a plaque index, the Modified Gingival Index and a bleeding index. RESULTS At 6 months, the essential oil-containing dentifrice group had statistically significantly (P < 0.001) lower whole-mouth and interproximal mean plaque index scores exhibiting mean reductions of 18.3% and 18.1% relative to the vehicle control. At 6 months, the essential oil-containing dentifrice group had statistically significantly (P < 0.001) lower whole-mouth and interproximal mean gingival index scores compared to the vehicle control with reductions of 16.2% and 15.5%, respectively. Finally, for the gingival bleeding index, the essential oil-containing dentifrice group had statistically significantly (P < 0.001) lower whole-mouth and interproximal mean bleeding index scores and reductions of 40.5% and 46.9% at 6 months compared to the vehicle control.
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Affiliation(s)
- J Coelho
- The Warner-Lambert Consumer Healthcare Division of the Warner-Lambert Consumer Group of Pfizer, Morris Plains, NJ 07950, USA.
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Mei YA, Wu MM, Huan CL, Sun JT, Zhou HQ, Zhang ZH. 4-aminopyridine, a specific blocker of K(+) channels, inhibited inward Na(+) current in rat cerebellar granule cells. Brain Res 2000; 873:46-53. [PMID: 10915809 DOI: 10.1016/s0006-8993(00)02469-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The effects of 4-aminopyridine (4-AP), a specific blocker of outward K(+) current, on voltage-activated transient outward K(+) current (I(K(A))) and inward Na(+) current (I(Na)) were investigated on cultured rat cerebellar granule cells using the whole cell voltage-clamp technique. At the concentration of 1-5 mM, 4-AP inhibited both I(K(A)) and I(Na). It reduced the amplitude of peak Na(+) current without significant alteration of the steady-state activation and inactivation properties. The inhibitory effect was not enhanced by repeated depolarizing pulses (0.5 or 0.1 Hz), suggesting that the binding affinity of 4-AP on Na(+) channels is state-independent. In contrast, the effect of 4-AP on Na(+) channels appeared to be voltage-dependent, the weaker inhibition occurred at more depolarization. Moreover, 4-AP slowed both the activation and inactivation kinetics of Na(+) current. These effects were similar to those induced by alpha-scorpion toxin and sea anemone toxins on Na(+) channels in other cell model. Our data demonstrate for the first time that 4-AP is able to block not only A-type K(+) channels, but also Na(+) channels in rat cerebellar granule cells. It is concluded that the inhibition exerted by 4-AP on Na(+) current likely differs from that provoked by local anesthetics. The possibility that the binding site of neurotoxin receptor 3 may be involved is discussed.
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Affiliation(s)
- Y A Mei
- Center for brain science research and Liren laboratory, School of Life Sciences, Fudan University, Shanghai, PR China.
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43
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Abstract
The U.S. Environmental Protection Agency is under a congressional mandate to revise its current standard for arsenic in drinking water. We present a risk assessment for cancers of the bladder, liver, and lung from exposure to arsenic in water, based on data from 42 villages in an arseniasis-endemic region of Taiwan. We calculate excess lifetime risk estimates for several variations of the generalized linear model and for the multistage-Weibull model. Risk estimates are sensitive to the model choice, to whether or not a comparison population is used to define the unexposed disease mortality rates, and to whether the comparison population is all of Taiwan or just the southwestern region. Some factors that may affect risk could not be evaluated quantitatively: the ecologic nature of the data, the nutritional status of the study population, and the dietary intake of arsenic. Despite all of these sources of uncertainty, however, our analysis suggests that the current standard of 50 microg/L is associated with a substantial increased risk of cancer and is not sufficiently protective of public health.
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Affiliation(s)
- K H Morales
- Department of Biostatistics, Harvard School of Public Health, Boston, MA 02115, USA
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Wu MM, Llopis J, Adams S, McCaffery JM, Kulomaa MS, Machen TE, Moore HP, Tsien RY. Organelle pH studies using targeted avidin and fluorescein-biotin. Chem Biol 2000; 7:197-209. [PMID: 10712929 DOI: 10.1016/s1074-5521(00)00088-0] [Citation(s) in RCA: 154] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
BACKGROUND Mammalian organelles of the secretory pathway are of differing pH. The pH values form a decreasing gradient: the endoplasmic reticulum (ER) is nearly neutral, the Golgi is mildly acidic and the secretory granules are more acidic still ( approximately pH 5). The mechanisms that regulate pH in these organelles are still unknown. RESULTS Using a novel method, we tested whether differences in H(+) 'leak' and/or counterion conductances contributed to the pH difference between two secretory pathway organelles. A pH-sensitive, membrane-permeable fluorescein-biotin was targeted to endoplasmic-reticulum- and Golgi-localized avidin-chimera proteins in HeLa cells. In live, intact cells, ER pH (pH(ER)) was 7.2 +/- 0.2 and Golgi pH (pH(G)) was 6.4 +/- 0.3 and was dissipated by bafilomycin. Buffer capacities of the cytosol, ER and Golgi were all similar (6-10 mM/pH). ER membranes had an apparent H(+) permeability three times greater than that of Golgi membranes. Removal of either K(+) or Cl(-) did not affect ER and Golgi H(+) leak rates, or steady-state pH(G) and pH(ER). CONCLUSIONS The Golgi is more acidic than the ER because it has an active H(+) pump and fewer or smaller H(+) leaks. Neither buffer capacity nor counterion permeabilities were key determinants of pH(G), pH(ER) or ER/Golgi H(+) leak rates.
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Affiliation(s)
- M M Wu
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
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Ko GT, Wu MM, Wai HP, Tang J, Chan CH, Kan EC, Chen R. Rapid increase in the prevalence of undiagnosed diabetes and impaired fasting glucose in asymptomatic Hong Kong Chinese. Diabetes Care 1999; 22:1751-2. [PMID: 10526753 DOI: 10.2337/diacare.22.10.1751] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Abstract
PURPOSE The etiology of myopia has been attributed to both genetic and environmental factors. The purpose of this paper is to attempt to distinguish between genetic and environmental factors in three generations of subjects from three locations. METHODS Noncycloplegic autorefraction and distance visual acuity were measured in 3131 Chinese children 7 to 17 years old from Hong Kong, Tianjin, and Ban Chau. Data on the refractive status of the parents and grandparents were collected using questionnaires. Myopia was defined operationally as spherical equivalent refractive error (SER) of at least -1.00 D and uncorrected vision worse than logMAR 0.18 (6/9). RESULTS The odds of having myopia for the grandparents', parents', and children's generations were 0.06, 0.26, and 0.35, respectively. Having myopic parents increased the odds ratio for having myopia (odds ratio 1.85 for children's generation and 6.71 for parents' generation), showing a genetic influence. However, the odds of having myopia also increased in offspring of nonmyopic parents between generation 2 and 3, suggesting an environmental influence. Results of prevalence and odds ratios from the three locations also demonstrated an environmental effect on development of myopia. CONCLUSION We propose that myopic development in Chinese follows a multifactorial and polygenic model in which the genetic input has remained constant while the environmental influence has increased over the last three generations.
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Affiliation(s)
- M M Wu
- The Hong Kong Polytechnic University, Hung Hom, Kowloon
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Eggimann P, Francioli P, Bille J, Schneider R, Wu MM, Chapuis G, Chiolero R, Pannatier A, Schilling J, Geroulanos S, Glauser MP, Calandra T. Fluconazole prophylaxis prevents intra-abdominal candidiasis in high-risk surgical patients. Crit Care Med 1999; 27:1066-72. [PMID: 10397206 DOI: 10.1097/00003246-199906000-00019] [Citation(s) in RCA: 340] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To evaluate the efficacy and safety of intravenous fluconazole for the prevention of intra-abdominal Candida infections in high-risk surgical patients. DESIGN Randomized, prospective, double-blind, placebo-controlled study. SETTING Two university-affiliated hospitals in Switzerland. PATIENTS Forty-nine surgical patients with recurrent gastrointestinal perforations or anastomotic leakages. INTERVENTIONS Prophylaxis with intravenous fluconazole (400 mg per day) or placebo continued until resolution of the underlying surgical condition. MEASUREMENTS AND MAIN RESULTS Patients were evaluated daily, and specimens for culture were obtained three times per week during prophylaxis. The primary study end points were the frequency of and the time to intra-abdominal Candida infections. Secondary end points were the frequency of candidiasis (intra-abdominal and extra-abdominal) and the emergence or persistence of Candida colonization. Among patients who were not colonized at study entry, Candida was isolated from surveillance cultures during prophylaxis in 15% of the patients in the fluconazole group and in 62% of the patients in the placebo group (relative risk, 0.25; 95% confidence interval, 0.07 to 0.96; p = .04). Candida peritonitis occurred in one of 23 patients (4%) who received fluconazole and in seven of 20 patients (35%) who received placebo (relative risk, 0.12; 95% confidence interval, 0.02 to 0.93; p = .02). In addition, one catheter-related Candida albicans sepsis occurred in a fluconazole-treated patient. Thus, overall, candidiasis developed in two fluconazole patients and seven placebo patients (relative risk, 0.25; 95% confidence interval, 0.06 to 1.06; p = .06). C. albicans accounted for 87% of the Candida species isolated before or during prophylaxis, and all C. albicans strains were susceptible to fluconazole. Fluconazole was well tolerated, and adverse events occurred at similar frequencies in both treatment groups. CONCLUSIONS Fluconazole prophylaxis prevents colonization and invasive intra-abdominal Candida infections in high-risk surgical patients.
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Affiliation(s)
- P Eggimann
- Department of Internal Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
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Glassner BJ, Weeda G, Allan JM, Broekhof JL, Carls NH, Donker I, Engelward BP, Hampson RJ, Hersmus R, Hickman MJ, Roth RB, Warren HB, Wu MM, Hoeijmakers JH, Samson LD. DNA repair methyltransferase (Mgmt) knockout mice are sensitive to the lethal effects of chemotherapeutic alkylating agents. Mutagenesis 1999; 14:339-47. [PMID: 10375003 DOI: 10.1093/mutage/14.3.339] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have generated mice deficient in O6-methylguanine DNA methyltransferase activity encoded by the murine Mgmt gene using homologous recombination to delete the region encoding the Mgmt active site cysteine. Tissues from Mgmt null mice displayed very low O6-methylguanine DNA methyltransferase activity, suggesting that Mgmt constitutes the major, if not the only, O6-methylguanine DNA methyltransferase. Primary mouse embryo fibroblasts and bone marrow cells from Mgmt -/- mice were significantly more sensitive to the toxic effects of the chemotherapeutic alkylating agents 1,3-bis(2-chloroethyl)-1-nitrosourea, streptozotocin and temozolomide than those from Mgmt wild-type mice. As expected, Mgmt-deficient fibroblasts and bone marrow cells were not sensitive to UV light or to the crosslinking agent mitomycin C. In addition, the 50% lethal doses for Mgmt -/- mice were 2- to 10-fold lower than those for Mgmt +/+ mice for 1,3-bis(2chloroethyl)-1-nitrosourea, N-methyl-N-nitrosourea and streptozotocin; similar 50% lethal doses were observed for mitomycin C. Necropsies of both wild-type and Mgmt -/mice following drug treatment revealed histological evidence of significant ablation of hematopoietic tissues, but such ablation occurred at much lower doses for the Mgmt -/- mice. These results demonstrate the critical importance of O6-methylguanine DNA methyltransferase in protecting cells and animals against the toxic effects of alkylating agents used for cancer chemotherapy.
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Affiliation(s)
- B J Glassner
- Department of Cancer Cell Biology, Harvard School of Public Health, Boston, MA 02115, USA
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Wang HZ, Zhao FL, He YJ, Zheng XG, Huang XG, Wu MM. Low-threshold lasing of a Rhodamine dye solution embedded with nanoparticle fractal aggregates. Opt Lett 1998; 23:777-779. [PMID: 18087339 DOI: 10.1364/ol.23.000777] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The spectral and temporal emission properties of a Rhodamine (Rh) dye solution embedded with nanoparticle fractal aggregates are studied. An experiment on the pump-power density dependence of Rh emission spectra shows that the lasing threshold of a Rh6G solution embedded with TiO(2) nanoparticle fractal aggregates is significantly reduced compared with that of a neat dye solution. The mechanism of this reduction in lasing threshold is discussed, together with the lasing properties of narrow bandwidth and short duration.
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Engelward BP, Allan JM, Dreslin AJ, Kelly JD, Wu MM, Gold B, Samson LD. A chemical and genetic approach together define the biological consequences of 3-methyladenine lesions in the mammalian genome. J Biol Chem 1998; 273:5412-8. [PMID: 9479003 DOI: 10.1074/jbc.273.9.5412] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
DNA-damaging agents produce a plethora of cellular responses that include p53 induction, cell cycle arrest, and apoptosis. It is generally assumed that it is the DNA damage produced by these agents that triggers such responses, but there is limited direct evidence to support this assumption. Here, we used DNA alkylation repair proficient and deficient isogenic mouse cell lines to demonstrate that the signal to trigger p53 induction, cell cycle arrest, and apoptosis in response to alkylating agents does emanate from DNA damage. Moreover, we established that 3-methyladenine, a relatively minor DNA lesion produced by most methylating agents (which form mainly 7-methylguanine), can specifically induce sister chromatid exchange, chromatid and chromosome gaps and breaks, S phase arrest, the accumulation of p53, and apoptosis. This study was made possible by the generation of 3-methyladenine DNA glycosylase null mutant cells by targeted homologous recombination and by the chemical synthesis of a methylating agent that almost exclusively produces 3-methyladenine DNA lesions. The combined use of these two experimental tools has defined the biological consequences of 3-methyladenine, a DNA lesion produced by endogenous cellular metabolites, environmental carcinogens, and chemotherapeutic alkylating agents.
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Affiliation(s)
- B P Engelward
- Department of Cancer Cell Biology, Harvard School of Public Health, Boston, Massachusetts 02115, USA
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