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Nadel G, Yao Z, Hacohen-Lev-Ran A, Wainstein E, Maik-Rachline G, Ziv T, Naor Z, Admon A, Seger R. Phosphorylation of PP2Ac by PKC is a key regulatory step in the PP2A-switch-dependent AKT dephosphorylation that leads to apoptosis. Cell Commun Signal 2024; 22:154. [PMID: 38419089 PMCID: PMC10900696 DOI: 10.1186/s12964-024-01536-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 02/17/2024] [Indexed: 03/02/2024] Open
Abstract
BACKGROUND Although GqPCR activation often leads to cell survival by activating the PI3K/AKT pathway, it was previously shown that in several cell types AKT activity is reduced and leads to JNK activation and apoptosis. The mechanism of AKT inactivation in these cells involves an IGBP1-coupled PP2Ac switch that induces the dephosphorylation and inactivation of both PI3K and AKT. However, the machinery involved in the initiation of PP2A switch is not known. METHODS We used phospho-mass spectrometry to identify the phosphorylation site of PP2Ac, and raised specific antibodies to follow the regulation of this phosphorylation. Other phosphorylations were monitored by commercial antibodies. In addition, we used coimmunoprecipitation and proximity ligation assays to follow protein-protein interactions. Apoptosis was detected by a TUNEL assay as well as PARP1 cleavage using SDS-PAGE and Western blotting. RESULTS We identified Ser24 as a phosphorylation site in PP2Ac. The phosphorylation is mediated mainly by classical PKCs (PKCα and PKCβ) but not by novel PKCs (PKCδ and PKCε). By replacing the phosphorylated residue with either unphosphorylatable or phosphomimetic residues (S24A and S24E), we found that this phosphorylation event is necessary and sufficient to mediate the PP2A switch, which ultimately induces AKT inactivation, and a robust JNK-dependent apoptosis. CONCLUSION Our results show that the PP2A switch is induced by PKC-mediated phosphorylation of Ser24-PP2Ac and that this phosphorylation leads to apoptosis upon GqPCR induction of various cells. We propose that this mechanism may provide an unexpected way to treat some cancer types or problems in the endocrine machinery.
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Affiliation(s)
- Guy Nadel
- Department of Immunology and Regenerative Biology, the Weizmann Institute of Science, Rehovot, Israel
| | - Zhong Yao
- Department of Immunology and Regenerative Biology, the Weizmann Institute of Science, Rehovot, Israel
| | - Avital Hacohen-Lev-Ran
- Department of Immunology and Regenerative Biology, the Weizmann Institute of Science, Rehovot, Israel
| | - Ehud Wainstein
- Department of Immunology and Regenerative Biology, the Weizmann Institute of Science, Rehovot, Israel
| | - Galia Maik-Rachline
- Department of Immunology and Regenerative Biology, the Weizmann Institute of Science, Rehovot, Israel
| | - Tamar Ziv
- Smoler Proteomic Center, Technion-Israel Institute of Technology, Haifa, Israel
| | - Zvi Naor
- Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel Aviv, Israel
| | - Arie Admon
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Rony Seger
- Department of Immunology and Regenerative Biology, the Weizmann Institute of Science, Rehovot, Israel.
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2
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Jadli A, Gomes K, Ballasy N, Wijesuriya T, Belke D, Fedak P, Patel V. Inhibition of smooth muscle cell death by Angiotensin 1-7 protects against abdominal aortic aneurysm. Biosci Rep 2023; 43:BSR20230718. [PMID: 37947205 PMCID: PMC10695742 DOI: 10.1042/bsr20230718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 10/31/2023] [Accepted: 11/02/2023] [Indexed: 11/12/2023] Open
Abstract
Abdominal aortic aneurysm (AAA) represents a debilitating vascular disease characterized by aortic dilatation and wall rupture if it remains untreated. We aimed to determine the effects of Ang 1-7 in a murine model of AAA and to investigate the molecular mechanisms involved. Eight- to 10-week-old apolipoprotein E-deficient mice (ApoEKO) were infused with Ang II (1.44 mg/kg/day, s.c.) and treated with Ang 1-7 (0.576 mg/kg/day, i.p.). Echocardiographic and histological analyses showed abdominal aortic dilatation and extracellular matrix remodeling in Ang II-infused mice. Treatment with Ang 1-7 led to suppression of Ang II-induced aortic dilatation in the abdominal aorta. The immunofluorescence imaging exhibited reduced smooth muscle cell (SMC) density in the abdominal aorta. The abdominal aortic SMCs from ApoEKO mice exhibited markedly increased apoptosis in response to Ang II. Ang 1-7 attenuated cell death, as evident by increased SMC density in the aorta and reduced annexin V/propidium iodide-positive cells in flow cytometric analysis. Gene expression analysis for contractile and synthetic phenotypes of abdominal SMCs showed preservation of contractile phenotype by Ang 1-7 treatment. Molecular analyses identified increased mitochondrial fission, elevated cellular and mitochondrial reactive oxygen species (ROS) levels, and apoptosis-associated proteins, including cytochrome c, in Ang II-treated aortic SMCs. Ang 1-7 mitigated Ang II-induced mitochondrial fission, ROS generation, and levels of pro-apoptotic proteins, resulting in decreased cell death of aortic SMCs. These results highlight a critical vasculo-protective role of Ang 1-7 in a degenerative aortic disease; increased Ang 1-7 activity may provide a promising therapeutic strategy against the progression of AAA.
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Affiliation(s)
- Anshul S. Jadli
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada
| | - Karina P. Gomes
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada
| | - Noura N. Ballasy
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada
| | - Tishani Methsala Wijesuriya
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada
| | - Darrell Belke
- Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada
- Section of Cardiac Surgery, Department of Cardiac Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Paul W.M. Fedak
- Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada
- Section of Cardiac Surgery, Department of Cardiac Sciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Vaibhav B. Patel
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Libin Cardiovascular Institute, University of Calgary, Calgary, AB, Canada
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3
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Hu XQ, Zhang L. Oxidative Regulation of Vascular Ca v1.2 Channels Triggers Vascular Dysfunction in Hypertension-Related Disorders. Antioxidants (Basel) 2022; 11:antiox11122432. [PMID: 36552639 PMCID: PMC9774363 DOI: 10.3390/antiox11122432] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 11/28/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
Blood pressure is determined by cardiac output and peripheral vascular resistance. The L-type voltage-gated Ca2+ (Cav1.2) channel in small arteries and arterioles plays an essential role in regulating Ca2+ influx, vascular resistance, and blood pressure. Hypertension and preeclampsia are characterized by high blood pressure. In addition, diabetes has a high prevalence of hypertension. The etiology of these disorders remains elusive, involving the complex interplay of environmental and genetic factors. Common to these disorders are oxidative stress and vascular dysfunction. Reactive oxygen species (ROS) derived from NADPH oxidases (NOXs) and mitochondria are primary sources of vascular oxidative stress, whereas dysfunction of the Cav1.2 channel confers increased vascular resistance in hypertension. This review will discuss the importance of ROS derived from NOXs and mitochondria in regulating vascular Cav1.2 and potential roles of ROS-mediated Cav1.2 dysfunction in aberrant vascular function in hypertension, diabetes, and preeclampsia.
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4
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Jin D, Lin L, Xie Y, Jia M, Qiu H, Xun K. NRF2-suppressed vascular calcification by regulating the antioxidant pathway in chronic kidney disease. FASEB J 2021; 36:e22098. [PMID: 34918390 DOI: 10.1096/fj.202100625rr] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 11/15/2021] [Accepted: 11/29/2021] [Indexed: 12/18/2022]
Abstract
Vascular calcification (VC), in which vascular smooth muscle cells (VSMCs) undergo differentiation and osteogenic transition, is a common complication of chronic kidney disease (CKD). Recent findings show that nuclear factor-erythroid-2-related factor 2 (NRF2) is an evolutionarily conserved antioxidant and beneficial in preventing vascular senescence and calcification. The roles of NRF2 in the initiation and progression of VC in CKD still need further investigation. CKD-associated VC model rats exhibited significant upregulation of NRF2, NAD(P)H: quinone oxidoreductase-1 (NQO1), osteogenic markers such as alkaline phosphatase (ALP), runt-related transcription factor-2 (RUNX2) and osteopontin (OPN), and β-catenin compared to CKD rats. Immunohistochemistry further verified these results. In addition, rat aortic VSMCs were isolated and subjected to four treatments: normal control, phosphorus-induced (Pi), Pi + NRF2 activator DMF, and Pi + NRF2 inhibitor ML385. The reactive oxygen species (ROS) generation, malondialdehyde (MDA) content, and calcium deposition of the four treatments were determined. The mRNA and protein expression levels of NRF2, NQO1, and haem oxygenase 1 (HO1) and the osteogenic markers ALP, Runx1, OPN, bone morphogenetic protein 2 (BMP2), and β-catenin were quantified by RT-PCR and western blotting. VSMC apoptosis was calculated by flow cytometry. The in vitro results suggested that intracellular oxidative stress and calcification were closely associated with NRF2 activity and that the activation of NRF2 could significantly suppress osteogenic transition and apoptosis in VSMCs. Thus, this study indicated that the NRF2-related antioxidant pathway can positively respond to and protect against the initiation and progression of VC in CKD by reducing oxidative stress. This study may contribute insights facilitating the application of the NRF2 antioxidative system as a therapeutic treatment for vascular diseases such as CKD.
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Affiliation(s)
- Donghua Jin
- Department of Nephrology, People's Hospital of Suzhou New District, Suzhou, China
| | - Lihua Lin
- Department of Nephrology, People's Hospital of Suzhou New District, Suzhou, China
| | - Yuxian Xie
- Department of Nephrology, People's Hospital of Suzhou New District, Suzhou, China
| | - Miao Jia
- Department of Nephrology, People's Hospital of Suzhou New District, Suzhou, China
| | - Hong Qiu
- Department of Nephrology, People's Hospital of Suzhou New District, Suzhou, China
| | - Kang Xun
- Department of Nephrology, People's Hospital of Suzhou New District, Suzhou, China
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5
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Lien CF, Chen SJ, Tsai MC, Lin CS. Potential Role of Protein Kinase C in the Pathophysiology of Diabetes-Associated Atherosclerosis. Front Pharmacol 2021; 12:716332. [PMID: 34276388 PMCID: PMC8283198 DOI: 10.3389/fphar.2021.716332] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 06/22/2021] [Indexed: 12/13/2022] Open
Abstract
Diabetes mellitus is a metabolic syndrome that affects millions of people worldwide. Recent studies have demonstrated that protein kinase C (PKC) activation plays an important role in hyperglycemia-induced atherosclerosis. PKC activation is involved in several cellular responses such as the expression of various growth factors, activation of signaling pathways, and enhancement of oxidative stress in hyperglycemia. However, the role of PKC activation in pro-atherogenic and anti-atherogenic mechanisms remains controversial, especially under hyperglycemic condition. In this review, we discuss the role of different PKC isoforms in lipid regulation, oxidative stress, inflammatory response, and apoptosis. These intracellular events are linked to the pathogenesis of atherosclerosis in diabetes. PKC deletion or treatment with PKC inhibitors has been studied in the regulation of atherosclerotic plaque formation and evolution. Furthermore, some preclinical and clinical studies have indicated that PKCβ and PKCδ are potential targets for the treatment of diabetic vascular complications. The current review summarizes these multiple signaling pathways and cellular responses regulated by PKC activation and the potential therapeutic targets of PKC in diabetic complications.
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Affiliation(s)
- Chih-Feng Lien
- Division of Cardiology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Sy-Jou Chen
- Department of Emergency Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
| | - Min-Chien Tsai
- Department of Physiology and Biophysics, Graduate Institute of Physiology, National Defense Medical Center, Taipei, Taiwan
| | - Chin-Sheng Lin
- Division of Cardiology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan
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6
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Hernández-Moreno D, Morales S, Camello-Almaraz C, Pozo MJ, Camello PJ. Monochloramine effects on gallbladder contractility. Clin Exp Pharmacol Physiol 2020; 48:597-604. [PMID: 33352621 DOI: 10.1111/1440-1681.13453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 12/04/2020] [Indexed: 11/28/2022]
Abstract
Digestive inflammatory processes induce motility alterations associated with an increase in reactive oxygen species production, including monochloramine (NH2 Cl). The aim of the study was to characterize the effects of the naturally occurring oxidant monochloramine in the guinea pig gallbladder. We used standard in vitro contractility technique to record guinea pig gallbladder strips contractions. NH2 Cl caused a concentration-dependent contraction which was reduced by inhibition of extracellular Ca2+ influx and tyrosine kinase pathways. The PKC antagonist GF109203X also reduced the response but not after previous tyrosine kinase inhibition, suggesting that PKC is activated by tyrosine kinase activity. The NH2 Cl contractile effect was also reduced by inhibitors of mitogen-activated protein kinase (MAPK), nitric oxide synthase, phospholipase A2 and cyclooxygenase. In addition, NH2 Cl impaired the responses to CCK, tissue depolarization and electrical field stimulation. In conclusion, we present new evidence that monochloramine impairs not only the gallbladder response to CCK but also to membrane depolarization and nervous plexus stimulation, and that tyrosine kinase, PKC, MAPK and NO pathways are involved in the contractile direct effect of monochloramine.
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Affiliation(s)
- David Hernández-Moreno
- Department of Environment and Agronomy, National Institute for Agricultural and Food Research and Technology (INIA), Madrid, Spain
| | - Sara Morales
- Department of Physiology, School of Nursing and Occupational Therapy, Institute of Biomarkers of Metabolic Pathologies, University of Extremadura, Caceres, Spain
| | - Cristina Camello-Almaraz
- Department of Physiology, School of Nursing and Occupational Therapy, Institute of Biomarkers of Metabolic Pathologies, University of Extremadura, Caceres, Spain
| | - María J Pozo
- Department of Physiology, School of Nursing and Occupational Therapy, Institute of Biomarkers of Metabolic Pathologies, University of Extremadura, Caceres, Spain
| | - Pedro J Camello
- Department of Physiology, School of Nursing and Occupational Therapy, Institute of Biomarkers of Metabolic Pathologies, University of Extremadura, Caceres, Spain
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7
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Cui L, Zhou Q, Zheng X, Sun B, Zhao S. Mitoquinone attenuates vascular calcification by suppressing oxidative stress and reducing apoptosis of vascular smooth muscle cells via the Keap1/Nrf2 pathway. Free Radic Biol Med 2020; 161:23-31. [PMID: 33011276 DOI: 10.1016/j.freeradbiomed.2020.09.028] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 09/13/2020] [Accepted: 09/26/2020] [Indexed: 12/26/2022]
Abstract
Oxidative stress and apoptosis of vascular smooth muscle cells (VSMCs) are key to vascular calcification in patients with chronic kidney disease (CKD). The mitochondria-targeted antioxidant, mitoquinone (MitoQ), which reduces oxidative stress and apoptosis, has a protective effect in acute models of renal injury but whether MitoQ can attenuate vascular calcification in CKD patients is unknown. This study was conducted to investigate whether MitoQ can prevent calcification, both in vitro and in vivo. Adenine was used to induce calcification in rats, and inorganic phosphate was used to induce calcification in VSMCs. To elucidate the underlying molecular mechanism, a specific inhibitor of Nrf2, ML385, was used 1 h before MitoQ administration. Histological staining, ELISA, flow cytometry, alizarin red staining and western blotting were used to test this hypothesis. Administration of MitoQ alleviated calcification and oxidative stress. The anti-apoptotic effect of MitoQ was associated with upregulation of Bcl-2, downregulation of Bax, and increased Nrf2 expression. The effects of MitoQ were reversed by treatment with ML385. This study offers evidence that MitoQ attenuates vascular calcification by suppressing oxidative stress and apoptosis of VSMCs through the Keap1/Nrf2 pathway. MitoQ should be further investigated as a potential therapy to prevent vascular calcification in CKD patients.
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Affiliation(s)
- Lei Cui
- Department of Nephrology, The First Affiliated Hospital of Harbin Medical University, China.
| | - Qi Zhou
- Scientific Research Management Office, The First Affiliated Hospital of Harbin Medical University, China
| | - Xiufeng Zheng
- Department of Cardiology, Heilongjiang Provincial Hospital, China
| | - Bowen Sun
- Department of Neurosurgery, The First Affiliated Hospital of Harbin Medical University, China
| | - Shilei Zhao
- Department of Nephrology, The First Affiliated Hospital of Harbin Medical University, China.
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8
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Lenkavska L, Tomkova S, Horvath D, Huntosova V. Searching for combination therapy by clustering methods: Stimulation of PKC in Golgi apparatus combined with hypericin induced PDT. Photodiagnosis Photodyn Ther 2020; 31:101813. [PMID: 32442674 DOI: 10.1016/j.pdpdt.2020.101813] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 04/28/2020] [Accepted: 05/04/2020] [Indexed: 02/07/2023]
Abstract
Cancer cell metabolism is a very attractive target for anticancer treatments. This work focuses on protein kinase C (PKC) signaling in the U87 MG glioma. By means of western blot, fluorescence and time-resolved fluorescence microscopy the correlation between the Golgi apparatus (GA), lysosomes and mitochondria were evaluated. The known regulators of PKC were applied to cancer cells. Phorbol myristate acetate (PMA) was chosen as the activator of PKC. Gö6976, hypericin and rottlerin, the inhibitors of PKCα and PKCδ were selected as well. Stabilization, destabilization processes occurring in cells allow classification of observations into several groups. Multiple versions of hierarchical cluster analysis have been applied and similarities have been found between organelles and PKC regulators. The method identified GA as an extraordinary organelle whose functionality is significantly influenced by PKC regulators as well as oxidative stress. Therefore, combination therapy has been designed according to the results of the cluster analysis. Furthermore, the efficacy of photodynamic therapy mediated by hypericin, and the consequent apoptosis, was significantly increased during the treatment. To our knowledge, this is the first demonstration of the effectiveness of the clustering in the given area.
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Affiliation(s)
- Lenka Lenkavska
- Department of Biophysics, Faculty of Science, P. J. Safarik University in Kosice, 041 54, Kosice, Slovakia.
| | - Silvia Tomkova
- Department of Biophysics, Faculty of Science, P. J. Safarik University in Kosice, 041 54, Kosice, Slovakia.
| | - Denis Horvath
- Center for Interdisciplinary Biosciences, Technology and Innovation Park, P.J. Safarik University in Kosice, 041 54, Kosice, Slovakia.
| | - Veronika Huntosova
- Center for Interdisciplinary Biosciences, Technology and Innovation Park, P.J. Safarik University in Kosice, 041 54, Kosice, Slovakia.
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9
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Bahia PK, Hadley SH, Barannikov I, Sowells I, Kim SH, Taylor-Clark TE. Antimycin A increases bronchopulmonary C-fiber excitability via protein kinase C alpha. Respir Physiol Neurobiol 2020; 278:103446. [PMID: 32360368 DOI: 10.1016/j.resp.2020.103446] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/15/2020] [Accepted: 04/18/2020] [Indexed: 12/17/2022]
Abstract
Inflammation can increase the excitability of bronchopulmonary C-fibers leading to excessive sensations and reflexes (e.g. wheeze and cough). We have previously shown modulation of peripheral nerve terminal mitochondria by antimycin A causes hyperexcitability in TRPV1-expressing bronchopulmonary C-fibers through the activation of protein kinase C (PKC). Here, we have investigated the PKC isoform responsible for this signaling. We found PKCβ1, PKCδ and PKCε were expressed by many vagal neurons, with PKCα and PKCβ2 expressed by subsets of vagal neurons. In dissociated vagal neurons, antimycin A caused translocation of PKCα but not the other isoforms, and only in TRPV1-lineage neurons. In bronchopulmonary C-fiber recordings, antimycin A increased the number of action potentials evoked by α,β-methylene ATP. Selective inhibition of PKCα, PKCβ1 and PKCβ2 with 50 nM bisindolylmaleimide I prevented the antimycin-induced bronchopulmonary C-fiber hyperexcitability, whereas selective inhibition of only PKCβ1 and PKCβ2 with 50 nM LY333531 had no effect. We therefore conclude that PKCα is required for antimycin-induced increases in bronchopulmonary C-fiber excitability.
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Affiliation(s)
- Parmvir K Bahia
- Department of Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Stephen H Hadley
- Department of Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Ivan Barannikov
- Department of Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Isobel Sowells
- Department of Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Seol-Hee Kim
- Department of Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Thomas E Taylor-Clark
- Department of Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA.
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An Engineered Gene Nanovehicle Developed for Smart Gene Therapy to Selectively Inhibit Smooth Muscle Cells: An In Vitro Study. Int J Mol Sci 2020; 21:ijms21041530. [PMID: 32102332 PMCID: PMC7073206 DOI: 10.3390/ijms21041530] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/19/2020] [Accepted: 02/20/2020] [Indexed: 12/03/2022] Open
Abstract
In-stent restenosis is a serious concern for patients treated through the stenting procedure, although this can be solved using drug-eluting stents and/or drug-eluting balloon catheters. However, the chemical agents released from the drug-eluting layer for inhibiting smooth muscle cell (SMC) migration are inevitably associated with damage to vascular endothelial cell (ECs). The present in vitro study used a distinct strategy, in which a smart gene (phEGR1-PKCδ, an engineered plasmid consists of an SMC-specific promoter (human early growth response 1, hEGR1 promoter) ligated with a gene encoding apoptosis-inducing protein (protein kinase C-delta, PKCδ) was incorporated into a novel gene vehicle (Au cluster-incorporated polyethylenimine/carboxymethyl hexanoyl chitosan, PEI-Au/CHC) to form the PEI-Au/CHC/phEGR1-PKCδ complex, which was proposed for the selective inhibition of SMC proliferation. It was found that the cell viability of SMCs receiving the PEI-Au/CHC/phEGR1-PKCδ complex under simulated inflammation conditions was significantly lower than that of the ECs receiving the same treatment. In addition, the PEI-Au/CHC/phEGR1-PKCδ complex did not demonstrate an inhibitory effect on EC proliferation and migration under simulated inflammation conditions. Finally, the PEI-Au/CHC/phEGR1-PKCδ complexes coated onto a balloon catheter used in percutaneous transluminal coronary angioplasty (PTCA) could be transferred to both the ECs and the SMC layer of Sprague Dawley (SD) rat aortas ex vivo. These preliminary in vitro results suggest that the newly developed approach proposed in the present study might be a potential treatment for reducing the incidence rate of in-stent restenosis and late thrombosis in the future.
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11
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Dükel M, Tavsan Z, Erdogan D, Erkan Gök D, Ayar Kayali H. Protein kinase C Inhibitors selectively modulate dynamics of cell adhesion molecules and cell death in human colon cancer cells. Cell Adh Migr 2018; 13:83-97. [PMID: 30289336 PMCID: PMC6527378 DOI: 10.1080/19336918.2018.1530933] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
During development of colon cancer, Protein Kinase Cs (PKCs) are involved in regulation of many genes controlling several cellular mechanisms. Here, we examined the changes in cell adhesion molecules and PKCs for colorectal cancer progression. We identified that PKCs affected expression of EpCAM, claudins, tetraspanins. Treatment with low concentrations of PKC inhibitors resulted in decreased cell viability. In addition, immunoblotting and qRT-PCR analysis showed that apoptosis was inhibited while autophagy was induced by PKC inhibition in colon cancer cells. Furthermore, we observed decreased levels of intracellular Reactive Oxygen Species (ROS), lipid peroxidation and protein carbonyl, confirming the ROS-induced apoptosis. Taken together, our results reveal that PKC signalling modulates not only cell adhesion dynamics but also cell death-related mechanisms. Abbreviations: PKC: Protein Kinase C; EpCAM: Epithelial cell adhesion molecule; FBS: fetal bovine serum; MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide); CAM: cell adhesion molecule; ROS: reactive oxygen species.
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Affiliation(s)
- Muzaffer Dükel
- a Moleculer Biology and Genetic Department, Faculty of Art and Science , Mehmet Akif Ersoy University , Burdur , Turkey.,b Izmir Biomedicine and Genome Center , Izmir , Turkey
| | - Zehra Tavsan
- b Izmir Biomedicine and Genome Center , Izmir , Turkey
| | - Duygu Erdogan
- c Izmir International Biomedicine and Genome Institute , Dokuz Eylül University , Izmir , Turkey
| | | | - Hulya Ayar Kayali
- b Izmir Biomedicine and Genome Center , Izmir , Turkey.,d Biochemistry Division, Chemistry Department, Science Faculty , Dokuz Eylul University , Izmir , Turkey
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12
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Hrubik J, Glisic B, Samardzija D, Stanic B, Pogrmic-Majkic K, Fa S, Andric N. Effect of PMA-induced protein kinase C activation on development and apoptosis in early zebrafish embryos. Comp Biochem Physiol C Toxicol Pharmacol 2016; 190:24-31. [PMID: 27521797 DOI: 10.1016/j.cbpc.2016.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 08/05/2016] [Accepted: 08/08/2016] [Indexed: 12/19/2022]
Abstract
Protein kinase C (PKC) isoforms have been implicated in several key steps during early development, but the consequences of xenobiotic-induced PKC activation during early embryogenesis are still unknown. In this study, zebrafish embryos were exposed to a range of phorbol 12-myristate 13-acetate (PMA) concentrations (0-200μg/L) at different time points after fertilization. Results showed that 200μgPMA/L caused development of yolk bags, cardiac edema, slow blood flow, pulsating blood flow, slow pulse, elongated heart, lack of tail fins, curved tail, and coagulation. PMA exposure decreased survival rate of the embryos starting within the first 24h and becoming more pronounced after prolonged exposure (96h). PMA increased the number of apoptotic cells in the brain region as demonstrated by acridine orange staining and caused up-regulation of caspase 9 (casp9) and p53 up-regulated modulator of apoptosis (puma) mRNA in whole embryos. PMA caused oxidative stress in the embryos as demonstrated by decreased mRNA expression of catalase and superoxide dismutase 2. Inhibition of Pkc with GF109203X improved overall survival rate, reduced apoptosis in the brain and decreased expression of casp9 and puma in the PMA-exposed embryos. However, Pkc inhibition neither prevented development of deformities nor reversed oxidative stress in the PMA-exposed embryos. These data suggest that direct over-activation of Pkc during early embryogenesis of zebrafish is associated with apoptosis and decreased survival rate of the embryos.
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Affiliation(s)
- Jelena Hrubik
- University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Laboratory for Ecotoxicology, Novi Sad, Serbia
| | - Branka Glisic
- University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Laboratory for Ecotoxicology, Novi Sad, Serbia
| | - Dragana Samardzija
- University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Laboratory for Ecotoxicology, Novi Sad, Serbia
| | - Bojana Stanic
- University of Novi Sad, Faculty of Technical Sciences, Department of Environmental Engineering and Occupational Safety and Health, Novi Sad, Serbia
| | - Kristina Pogrmic-Majkic
- University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Laboratory for Ecotoxicology, Novi Sad, Serbia
| | - Svetlana Fa
- University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Laboratory for Ecotoxicology, Novi Sad, Serbia
| | - Nebojsa Andric
- University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Laboratory for Ecotoxicology, Novi Sad, Serbia.
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Di A, Mehta D, Malik AB. ROS-activated calcium signaling mechanisms regulating endothelial barrier function. Cell Calcium 2016; 60:163-71. [PMID: 26905827 DOI: 10.1016/j.ceca.2016.02.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 02/03/2016] [Accepted: 02/04/2016] [Indexed: 02/07/2023]
Abstract
Increased vascular permeability is a common pathogenic feature in many inflammatory diseases. For example in acute lung injury (ALI) and its most severe form, the acute respiratory distress syndrome (ARDS), lung microvessel endothelia lose their junctional integrity resulting in leakiness of the endothelial barrier and accumulation of protein rich edema. Increased reactive oxygen species (ROS) generated by neutrophils (PMNs) and other inflammatory cells play an important role in increasing endothelial permeability. In essence, multiple inflammatory syndromes are caused by dysfunction and compromise of the barrier properties of the endothelium as a consequence of unregulated acute inflammatory response. This review focuses on the role of ROS signaling in controlling endothelial permeability with particular focus on ALI. We summarize below recent progress in defining signaling events leading to increased endothelial permeability and ALI.
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Affiliation(s)
- Anke Di
- Department of Pharmacology, The University of Illinois College of Medicine, Chicago, IL 60612, United States
| | - Dolly Mehta
- Department of Pharmacology, The University of Illinois College of Medicine, Chicago, IL 60612, United States
| | - Asrar B Malik
- Department of Pharmacology, The University of Illinois College of Medicine, Chicago, IL 60612, United States.
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Rong S, Hueper K, Kirsch T, Greite R, Klemann C, Mengel M, Meier M, Menne J, Leitges M, Susnik N, Meier M, Haller H, Shushakova N, Gueler F. Renal PKC-ε deficiency attenuates acute kidney injury and ischemic allograft injury via TNF-α-dependent inhibition of apoptosis and inflammation. Am J Physiol Renal Physiol 2014; 307:F718-26. [DOI: 10.1152/ajprenal.00372.2013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Acute kidney injury (AKI) increases the risk of morbidity and mortality after major surgery and transplantation. We investigated the effect of PKC-ε deficiency on AKI and ischemic allograft damage after kidney transplantation. PKC-ε-deficient and wild type (WT) control mice were subjected to 35 min of renal pedicle clamping to induce AKI. PKC-ε deficiency was associated with a marked improvement in survival and an attenuated loss of kidney function. Furthermore, functional MRI experiments revealed better renal perfusion in PKC-ε-deficient mice than in WT mice one day after IRI. Acute tubular necrosis and neutrophil infiltration were markedly reduced in PKC-ε-deficient mice. To determine whether this resistance to ischemia-reperfusion injury resulted from changes in local renal cells or infiltrating leukocytes, we studied a life-supporting renal transplant model of ischemic graft injury. We transplanted kidneys from H2b PKC-ε-deficient mice (129/SV) and their corresponding WT littermates into major histocompatibility complex-incompatible H2d recipients (BALB/c) and induced ischemic graft injury by prolonged cold ischemia time. Recipients of WT allografts developed severe renal failure and died within 10 days of transplantation. Recipients of PKC-ε-deficient allografts had better renal function and survival; they had less generation of ROS and upregulation of proinflammatory proteins (i.e., ICAM-1, inducible nitric oxide synthase, and TNF-α) and showed less tubular epithelial cell apoptosis and inflammation in their allografts. These data suggest that local renal PKC-ε expression mediates proapoptotic and proinflammatory signaling and that an inhibitor of PKC-ε signaling could be used to prevent hypoxia-induced AKI.
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Affiliation(s)
- Song Rong
- Department of Nephrology, Hannover Medical School, Hannover, Germany
- The Transplantation Center, Affiliated Hospital, Zunyi Medical College, Zunyi, China
| | - Katja Hueper
- Institute for Diagnostic and Interventional Radiology, Medical School Hannover, Hannover, Germany
| | - Torsten Kirsch
- Department of Nephrology, Hannover Medical School, Hannover, Germany
| | - Robert Greite
- Department of Nephrology, Hannover Medical School, Hannover, Germany
| | - Christian Klemann
- Centre for Paediatrics and Adolescent Medicine, Department of Pediatric Surgery, Hannover Medical School, Hannover, Germany
| | - Michael Mengel
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Canada
| | - Matthias Meier
- Department of Nephrology, Hannover Medical School, Hannover, Germany
| | - Jan Menne
- Department of Nephrology, Hannover Medical School, Hannover, Germany
- Phenos GmbH, Hannover, Germany
| | - Michael Leitges
- Department of Nephrology, Hannover Medical School, Hannover, Germany
- The Biotechnology Centre of Oslo, University of Oslo, Oslo, Norway
| | - Nathan Susnik
- Department of Nephrology, Hannover Medical School, Hannover, Germany
| | - Martin Meier
- Imaging Center, Institute for Animal Science, Medical School Hannover, Hannover, Germany; and
| | - Hermann Haller
- Department of Nephrology, Hannover Medical School, Hannover, Germany
| | - Nelli Shushakova
- Department of Nephrology, Hannover Medical School, Hannover, Germany
- Phenos GmbH, Hannover, Germany
| | - Faikah Gueler
- Department of Nephrology, Hannover Medical School, Hannover, Germany
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15
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Musumeci G, Coleman R, Imbesi R, Magro G, Parenti R, Szychlinska MA, Scuderi R, Cinà CS, Castorina S, Castrogiovanni P. ADAM-10 could mediate cleavage of N-cadherin promoting apoptosis in human atherosclerotic lesions leading to vulnerable plaque: a morphological and immunohistochemical study. Acta Histochem 2014; 116:1148-58. [PMID: 24985126 DOI: 10.1016/j.acthis.2014.06.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 06/01/2014] [Accepted: 06/02/2014] [Indexed: 01/03/2023]
Abstract
Atherosclerosis remains a major cause of mortality. Whereas the histopathological progression of atherosclerotic lesions is well documented, much less is known about the development of unstable or vulnerable plaque, which can rupture leading to thrombus, luminal occlusion and infarct. Apoptosis in the fibrous cap, which is rich in vascular smooth muscle cells (VSMCs) and macrophages, and its subsequent weakening or erosion seems to be an important regulator of plaque stability. The aim of our study was to improve our knowledge on the biological mechanisms that cause plaque instability in order to develop new therapies to maintain atherosclerotic plaque stability and avoid its rupture. In our study, we collected surgical specimens from atherosclerotic plaques in the right or left internal carotid artery of 62 patients with evident clinical symptoms. Histopathology and histochemistry were performed on wax-embedded sections. Immunohistochemical localization of caspase-3, N-cadherin and ADAM-10 was undertaken in order to highlight links between apoptosis, as expressed by caspase-3 immunostaining, and possible roles of N-cadherin, a cell-cell junction protein in VSMCs and macrophages that provides a pro-survival signal reducing apoptosis, and ADAM-10, a "disintegrin and metalloproteases" that is able to cleave N-cadherin in glioblastomas. Our results showed that when apoptosis, expressed by caspase-3 immunostaining, increased in the fibrous cap, rich in VSMCs and macrophages, the expression of N-cadherin decreased. The decreased N-cadherin expression, in turn, was linked to increased ADAM-10 expression. This study shows that apoptotic events are probably involved in the vulnerability of atherosclerotic plaque.
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16
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Ng SF, Lin RCY, Maloney CA, Youngson NA, Owens JA, Morris MJ. Paternal high-fat diet consumption induces common changes in the transcriptomes of retroperitoneal adipose and pancreatic islet tissues in female rat offspring. FASEB J 2014; 28:1830-41. [PMID: 24421403 DOI: 10.1096/fj.13-244046] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We previously showed that paternal high-fat diet (HFD) consumption programs β-cell dysfunction in female rat offspring, together with transcriptome alterations in islets. Here we investigated the retroperitoneal white adipose tissue (RpWAT) transcriptome using gene and pathway enrichment and pathway analysis to determine whether commonly affected network topologies exist between these two metabolically related tissues. In RpWAT, 5108 genes were differentially expressed due to a paternal HFD; the top 5 significantly enriched networks identified by pathway analysis in offspring of HFD fathers compared with those of fathers fed control diet were: mitochondrial and cellular response to stress, telomerase signaling, cell death and survival, cell cycle, cellular growth and proliferation, and cancer. A total of 187 adipose olfactory receptor genes were down-regulated. Interrogation against the islet transcriptome identified specific gene networks and pathways, including olfactory receptor genes that were similarly affected in both tissues (411 common genes, P<0.05). In particular, we highlight a common molecular network, cell cycle and cancer, with the same hub gene, Myc, suggesting early onset developmental changes that persist, shared responses to programmed systemic factors, or crosstalk between tissues. Thus, paternal HFD consumption triggers unique gene signatures, consistent with premature aging and chronic degenerative disorders, in both RpWAT and pancreatic islets of daughters.
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Affiliation(s)
- Sheau-Fang Ng
- 1Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia, 2052.
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17
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Sobhia ME, Grewal BK, Ml SP, Patel J, Kaur A, Haokip T, Kokkula A. Protein kinase C inhibitors: a patent review (2008 - 2009). Expert Opin Ther Pat 2013; 23:1297-315. [PMID: 23795914 DOI: 10.1517/13543776.2013.805205] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
INTRODUCTION The protein kinase C (PKC) is a family of multifunctional isoenzymes involved in apoptosis, migration, adhesion, tumorgenesis, cardiac hypertrophy, angiogenesis, platelet function and inflammation. It also plays a vital role in the regulation of signal transduction, cell proliferation and differentiation through positive and negative regulation of the cell cycle. In this work, we reviewed the existing PKC inhibitors and several patents linked to PKC inhibitors. AREAS COVERED Thorough survey on the PKC inhibitors having clinical importance and patents filed for these inhibitors from 2008 - 2009 is reported. EXPERT OPINION PKCs are highly potential therapeutic targets for treating diabetic complications, oncological, inflammatory, immunological and dermatological disorders. The clinical trial candidates of PKCs mainly target the catalytic domain, which is highly conserved throughout the PKC family making it difficult to target a particular isoform selectively. Relatively less chemical space and fewer bisubstrate inhibitors targeting both ATP and regulatory domain are explored for PKCs, more research in these areas will be helpful in overcoming existing problems.
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Affiliation(s)
- M Elizabeth Sobhia
- National Institute of Pharmaceutical Education and Research (NIPER), Department of Pharmacoinformatics , Sector 67, SAS Nagar (Mohali), Punjab , India
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Affiliation(s)
- Vicki Thallas-Bonke
- Diabetes Complications Division, Baker IDI Heart & Diabetes Institute, Melbourne, Victoria, Australia.
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19
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Lu D, Liu J, Jiao J, Long B, Li Q, Tan W, Li P. Transcription factor Foxo3a prevents apoptosis by regulating calcium through the apoptosis repressor with caspase recruitment domain. J Biol Chem 2013; 288:8491-8504. [PMID: 23382383 DOI: 10.1074/jbc.m112.442061] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Apoptosis can occur in the myocardium under a variety of pathological conditions, including myocardial infarction and heart failure. The forkhead family of transcription factor Foxo3a plays a pivotal role in apoptosis; however, its role in regulating cardiac apoptosis remains to be fully elucidated. We showed that enforced expression of Foxo3a inhibits cardiomyocyte apoptosis, whereas knockdown of endogenous Foxo3a sensitizes cardiomyocytes to undergo apoptosis. The apoptosis repressor with caspase recruitment domain (ARC) is a potent anti-apoptotic protein. Here, we demonstrate that it attenuates the release of calcium from the sarcoplasmic reticulum and inhibits calcium elevations in the cytoplasm and mitochondria provoked by oxidative stress in cardiomyocytes. Furthermore, Foxo3a is shown to maintain cytoplasmic and mitochondrial calcium homeostasis through ARC. We observed that Foxo3a knock-out mice exhibited enlarged myocardial infarction sizes upon ischemia/reperfusion, and ARC transgenic mice demonstrated reduced myocardial infarction and balanced calcium levels in mitochondria and sarcoplasmic reticulum. Moreover, we showed that Foxo3a activates ARC expression by directly binding to its promoter. This study reveals that Foxo3a maintains calcium homeostasis and inhibits cardiac apoptosis through trans-activation of the ARC promoter. These findings provided novel evidence that Foxo3a and ARC constitute an anti-apoptotic pathway that regulates calcium homeostasis in the heart.
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Affiliation(s)
- Daoyuan Lu
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jinping Liu
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jianqin Jiao
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Bo Long
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Qian Li
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Weiqi Tan
- Division of Cardiovascular Research, State Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Peifeng Li
- College of Medicine, University of Illinois at Chicago, Chicago, Illinois 60612.
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Son YK, Hong DH, Choi TH, Choi SW, Shin DH, Kim SJ, Jung ID, Park YM, Jung WK, Kim DJ, Choi IW, Park WS. The inhibitory effect of BIM (I) on L-type Ca²⁺ channels in rat ventricular cells. Biochem Biophys Res Commun 2012; 423:110-5. [PMID: 22634012 DOI: 10.1016/j.bbrc.2012.05.091] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 05/16/2012] [Indexed: 02/04/2023]
Abstract
We investigated the effect of a specific protein kinase C (PKC) inhibitor, bisindolylmaleimide I [BIM (I)], on L-type Ca(2+) channels in rat ventricular myocytes. BIM (I) alone inhibited the L-type Ca(2+) current in a concentration-dependent manner, with a K(d) value of 3.31 ± 0.25 μM, and a Hill coefficient of 2.34 ± 0.23. Inhibition was immediate after applying BIM (I) in the bath solution and then it partially washed out. The steady-state activation curve was not altered by applying 3μ M BIM (I), but the steady-state inactivation curve shifted to a more negative potential with a change in the slope factor. Other PKC inhibitors, PKC-IP and chelerythrine, showed no significant effects either on the L-type Ca(2+) current or on the inhibitory effect of BIM (I) on the L-type Ca(2+) current. The results suggest that the inhibitory effect of BIM (I) on the L-type Ca(2+) current is independent of the PKC pathway. Thus, our results should be considered in studies using BIM (I) to inhibit PKC activity and ion channel modulation.
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Affiliation(s)
- Youn Kyoung Son
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon, Republic of Korea
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21
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Cigarette smoke extract stimulates rat pulmonary artery smooth muscle cell proliferation via PKC-PDGFB signaling. J Biomed Biotechnol 2012; 2012:534384. [PMID: 22754279 PMCID: PMC3384980 DOI: 10.1155/2012/534384] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 04/17/2012] [Accepted: 04/23/2012] [Indexed: 11/29/2022] Open
Abstract
Accumulating evidence suggests a direct role for cigarette smoke in pulmonary vascular remodeling, which contributes to the development of pulmonary hypertension. However, the molecular mechanisms underlying this process remain poorly understood. Platelet-derived growth factor (PDGF) is a potential mitogen and chemoattractant implicated in several biological processes, including cell survival, proliferation, and migration. In this study, we investigated the effect of cigarette smoke extract (CSE) on cell proliferation of rat pulmonary artery smooth muscle cells (rPASMCs). We found that stimulation of rPASMCs with CSE significantly increased cell proliferation and promoted cell cycle progression from G1 phase to the S and G2 phases. CSE treatment also significantly upregulated the mRNA and protein levels of PDGFB and PDGFRβ. Our study also revealed that Rottlerin, an inhibitor of PKCδ signaling, prevented CSE-induced cell proliferation, attenuated the increase of S and G2 phase populations induced by CSE treatment, and downregulated PDGFB and PDGFRβ mRNA and protein levels in rPASMCs exposed to CSE. Collectively, our data demonstrated that CSE-induced cell proliferation of rPASMCs involved upregulation of the PKCδ-PDGFB pathway.
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Gabunia K, Ellison SP, Singh H, Datta P, Kelemen SE, Rizzo V, Autieri MV. Interleukin-19 (IL-19) induces heme oxygenase-1 (HO-1) expression and decreases reactive oxygen species in human vascular smooth muscle cells. J Biol Chem 2011; 287:2477-84. [PMID: 22158875 DOI: 10.1074/jbc.m111.312470] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Heme oxygenase-1 (HO-1) has potent anti-inflammatory activity and recognized vascular protective effects. We have recently described the expression and vascular protective effects of an anti-inflammatory interleukin (IL-19), in vascular smooth muscle cells (VSMC) and injured arteries. The objective of this study was to link the anti-inflammatory effects of IL-19 with HO-1 expression in resident vascular cells. IL-19 induced HO-1 mRNA and protein in cultured human VSMC, as assayed by quantitative RT-PCR, immunoblot, and ELISA. IL-19 does not induce HO-1 mRNA or protein in human endothelial cells. IL-19 activates STAT3 in VSMC, and IL-19-induced HO-1 expression is significantly reduced by transfection of VSMC with STAT3 siRNA or mutation of the consensus STAT binding site in the HO-1 promoter. IL-19 treatment can significantly reduce ROS-induced apoptosis, as assayed by Annexin V flow cytometry. IL-19 significantly reduced ROS concentrations in cultured VSMC. The IL-19-induced reduction in ROS concentration is attenuated when HO-1 is reduced by siRNA, indicating that the IL-19-driven decrease in ROS is mediated by HO-1 expression. IL-19 reduces vascular ROS in vivo in mice treated with TNFα. This points to IL-19 as a potential therapeutic for vascular inflammatory diseases and a link for two previously unassociated protective processes: Th2 cytokine-induced anti-inflammation and ROS reduction.
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Affiliation(s)
- Khatuna Gabunia
- Department of Physiology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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23
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Son YK, Hong DH, Kim DJ, Firth AL, Park WS. Direct effect of protein kinase C inhibitors on cardiovascular ion channels. BMB Rep 2011; 44:559-65. [DOI: 10.5483/bmbrep.2011.44.9.559] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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Zinkevich NS, Gutterman DD. ROS-induced ROS release in vascular biology: redox-redox signaling. Am J Physiol Heart Circ Physiol 2011; 301:H647-53. [PMID: 21685266 DOI: 10.1152/ajpheart.01271.2010] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The involvement of reactive oxygen species (ROS) in regulating vascular function both in normal vessels and as part of an adaptive response during disease has been intensively studied. From the recognition that ROS serve as important signaling molecules has emerged multiple lines of evidence that there is a functional connectivity between intracellular sites of ROS production. This cross talk has been termed ROS-induced ROS release (RIRR) and is supported by a variety of observations showing that RIRR is a common mechanism for ROS amplification and regional ROS generation. The compartmentalization of ROS production within a cell is critical to its signaling function and is facilitated by microlocalization of specific scavengers. This review will provide descriptions and examples of important mechanisms of RIRR.
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Affiliation(s)
- Natalya S Zinkevich
- Cardiovascular Center, Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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25
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Caraballo JC, Yshii C, Westphal W, Moninger T, Comellas AP. Ambient particulate matter affects occludin distribution and increases alveolar transepithelial electrical conductance. Respirology 2011; 16:340-9. [PMID: 21122029 DOI: 10.1111/j.1440-1843.2010.01910.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND AND OBJECTIVE Inhaled particulate matter (PM) causes lung inflammation and epithelial dysfunction. However, the direct effect of PM on alveolar epithelial barrier integrity is not well understood. Our aim is to determine whether PM exposure affects the alveolar epithelial cells (AEC) transepithelial electrical conductance (Gt) and tight junction (TJ) proteins. METHODS Human AEC (A549) and primary rat AEC were exposed to PM of <10 µm in size (PM(10) ) and diesel exhaust particles (DEP), using titanium dioxide (TiO(2) ) as a control for particle size effects. Gt and permeability to fluorescein isothiocyanate-dextran (FITC-Dextran) were measured to assess barrier integrity. TJ integrity was evaluated by analysing penetration of Lanthanum nitrate (La(3+) ) under transmission electron microscopy. Surface proteins were labelled with biotin and analysed by western blot. Immunofluorescence was performed to assess colocalization of TJ proteins including occludin and zonula occludens-1 (ZO-1). PM induced dissociation of occludin-ZO-1 was evaluated by co-immunoprecipitation. RESULTS PM(10) and DEP increased Gt and disrupted TJ after 3 h of treatment. PM(10) and DEP induced occludin internalization from the plasma membrane into endosomal compartments and dissociation of occludin from ZO-1. Overexpression of antioxidant enzymes manganese superoxide dismutase (MnSOD) and catalase, prevented PM-induced Gt increase, occludin reduction from the plasma membrane and its dissociation from ZO-1. CONCLUSIONS PM induces alveolar epithelial dysfunction in part via occludin reduction at the plasma membrane and ZO-1 dissociation in AEC. Furthermore, these effects are prevented by overexpression of two different antioxidant enzymes.
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Affiliation(s)
- Juan C Caraballo
- Internal Medicine Department, University of Iowa, Iowa City, Iowa 52242, USA
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Park J, Kwon MK, Huh JY, Choi WJ, Jeong LS, Nagai R, Kim WY, Kim J, Lee GT, Lee HB, Ha H. Renoprotective antioxidant effect of alagebrium in experimental diabetes. Nephrol Dial Transplant 2011; 26:3474-84. [DOI: 10.1093/ndt/gfr152] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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27
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Marengo B, De Ciucis C, Ricciarelli R, Passalacqua M, Nitti M, Zingg JM, Marinari UM, Pronzato MA, Domenicotti C. PKCδ sensitizes neuroblastoma cells to L-buthionine-sulfoximine and etoposide inducing reactive oxygen species overproduction and DNA damage. PLoS One 2011; 6:e14661. [PMID: 21326872 PMCID: PMC3034714 DOI: 10.1371/journal.pone.0014661] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Accepted: 01/17/2011] [Indexed: 11/18/2022] Open
Abstract
Neuroblastoma is a type of pediatric cancer. The sensitivity of neuroblastoma (NB) cancer cells to chemotherapy and radiation is inhibited by the presence of antioxidants, such as glutathione (GSH), which is crucial in counteracting the endogenous production of reactive oxygen species (ROS). We have previously demonstrated that cells depleted of GSH undergo apoptosis via oxidative stress and Protein kinase C (PKC) δ activation. In the present study, we transfected PKCδ in NB cells resistant to oxidative death induced by L-buthionine-S,R-sulfoximine (BSO), a GSH-depleting agent. Cell responses, in terms of ROS production, apoptosis and DNA damage were evaluated. Moreover, PKCδ activation was monitored by analyzing the phosphorylation status of threonine 505 residue, carrying out PKC activity assay and investigating the subcellular localization of the kinase. The cell responses obtained in BSO-resistant cells were also compared with those obtained in BSO-sensitive cells subjected to the same experimental protocol. Our results demonstrate, for the first time, that PKCδ induces DNA oxidation and ROS overproduction leading to apoptosis of BSO-resistant NB cells and potentiates the cytotoxic effects induced by BSO in sensitive cells. Moreover, PKCδ overexpression enhances the sensitivity of NB cells to etoposide, a well-characterised drug, commonly used in neuroblastoma therapy. Altogether our data provide evidence of a pro-oxidant role of PKCδ that might be exploited to design new therapeutic strategies aimed at selective killing of cancer cells and overcoming drug resistance. However, it becomes evident that a more detailed understanding of ROS-mediated signaling in cancer cells is necessary for the development of redox-modulated therapeutic approaches.
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Affiliation(s)
| | - Chiara De Ciucis
- General Pathology Section, Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Roberta Ricciarelli
- General Pathology Section, Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Mario Passalacqua
- Biochemistry Section, Department of Experimental Medicine, University of Genoa, Genoa, Italy
- Centre of Excellence for Biomedical Research, University of Genoa, Genoa, Italy
| | - Mariapaola Nitti
- General Pathology Section, Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | | | - Umberto M. Marinari
- General Pathology Section, Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Maria A. Pronzato
- General Pathology Section, Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Cinzia Domenicotti
- General Pathology Section, Department of Experimental Medicine, University of Genoa, Genoa, Italy
- * E-mail:
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Morshed SA, Ando T, Latif R, Davies TF. Neutral antibodies to the TSH receptor are present in Graves' disease and regulate selective signaling cascades. Endocrinology 2010; 151:5537-49. [PMID: 20844004 PMCID: PMC2954721 DOI: 10.1210/en.2010-0424] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
TSH receptor (TSHR) antibodies (Abs) may be stimulating, blocking, or neutral in their functional influences and are found in patients with autoimmune thyroid disease, especially Graves' disease (GD). Stimulators are known to activate the thyroid epithelial cells via both Gs- and Gq-coupled signaling pathways, whereas blockers inhibit the action of TSH and may act as weak agonists. However, TSHR neutral Abs do not block TSH binding and are unable to induce cAMP via Gsα. The importance of such neutral Abs in GD remains unclear because their functional consequence has been assumed to be zero. We hypothesized that: 1) neutral TSHR Abs are more common to GD than generally recognized; 2) they may induce distinct signaling imprints at the TSHR not seen with TSH itself; and 3) these signaling events may alter cellular function. To evaluate these hypotheses, we first confirmed the presence of neutral TSHR Abs in sera from patients with GD and then, using mouse and hamster neutral TSHR monoclonal Abs (N-mAbs) performed detailed signaling studies, including a proteomic Ab array, with rat thyrocytes (FRTL-5) as targets. This allowed us to examine a battery of signaling cascades and their downstream effectors. Neutral TSHR Abs were indeed frequently present in sera from patients with GD. Sixteen of 27 patients (59%) had detectable neutral TSHR Abs by competition assay with N-mAbs. On examining signaling cascades, we found that N-mAbs induced signal transduction, primarily via the protein kinase A II cascade. In addition to the activation of phosphatidylinositol 3K/Akt, N-mAbs, unlike TSH, had the ability to exclusively activate the mammalian target of rapamycin/p70 S6K, nuclear factor-κB, and MAPK-ERK1/2/p38α signaling cascades and their downstream effectors p90 ribosomal kinase/MAPK-interacting kinase-1/mitogen and stress-activated kinase-1 and N-mAbs activated all forms of protein kinase C isozymes. To define the downstream effector mechanisms produced by these signaling cascades, cytokine production, proliferation, and apoptosis in thyrocytes were investigated. Although N-mAbs produced less cytokines and proliferation compared with TSH, they had the distinction of inducing thyroid cell apoptosis under the experimental conditions used. When dissecting out possible mechanisms of apoptosis, we found that activation of multiple oxidative stress markers was the primary mechanism orchestrating the death signals. Therefore, using oxidative stress-induced apoptosis, N-mAbs may be capable of exacerbating the autoimmune response in GD via apoptotic cells inducing antigen-driven mechanisms. This may help explain the inflammatory nature of this common disorder.
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Affiliation(s)
- Syed A Morshed
- Thyroid Research Unit, Mount Sinai School of Medicine, James J. Peters Veterans Affairs Medical Center, New York, New York 10468, USA.
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Niwa K, Sakai J, Karino T, Aonuma H, Watanabe T, Ohyama T, Inanami O, Kuwabara M. Reactive oxygen species mediate shear stress-induced fluid-phase endocytosis in vascular endothelial cells. Free Radic Res 2009; 40:167-74. [PMID: 16390826 DOI: 10.1080/10715760500474287] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
To elucidate the role of shear stress in fluid-phase endocytosis of vascular endothelial cells (EC), we used a rotating-disk shearing apparatus to investigate the effects of shear stress on the uptake of lucifer yellow (LY) by cultured bovine aortic endothelial cells (BAEC). Exposure of EC to shear stress (area-mean value of 10 dynes/cm2) caused an increase in LY uptake that was abrogated by the antioxidant, N-acetyl-L-cysteine (NAC), the NADPH oxidase inhibitor, acetovanillone, and two inhibitors of protein kinase C (PKC), calphostin C and GF109203X. These results suggest that fluid-phase endocytosis is regulated by both reactive oxygen species (ROS) and PKC. Shear stress increased both ROS production and PKC activity in EC, and the increase in ROS was unaffected by calphostin C or GF109203X, whereas the activation of PKC was reduced by NAC and acetovanillone. We conclude that shear stress-induced increase in fluid-phase endocytosis is mediated via ROS generation followed by PKC activation in EC.
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Affiliation(s)
- Koichi Niwa
- Faculty of Bioindustry, Tokyo University of Agriculture, Department of Food Science and Technology, 196 Yasaka, Abashiri, 099-2493, Japan.
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Schauer IE, Reusch JEB. Nonesterified fatty acid exposure activates protective and mitogenic pathways in vascular smooth muscle cells by alternate signaling pathways. Metabolism 2009; 58:319-27. [PMID: 19217446 PMCID: PMC2901169 DOI: 10.1016/j.metabol.2008.10.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2006] [Accepted: 10/09/2008] [Indexed: 10/21/2022]
Abstract
Vascular smooth muscle cells (VSMC) are dynamic cells exposed to fluctuating concentrations of nutrients on a daily basis. Nonesterified fatty acids (NEFA) have been indicted as potential mediators of atherosclerosis and exaggerated VSMC remodeling observed in diabetes, and in vitro data support a model of VSMC activation by NEFA. However, recent observations suggest that metabolic stressors such as oxidants and NEFA may also simultaneously induce cytoprotective events as part of a homeostatic "off switch." Our group has established that the transcription factor cyclic adenosine monophosphate response element binding protein (CREB) is important for maintenance of VSMC quiescence, differentiation, and survival. We therefore examined whether acute physiologic NEFA exposure would regulate CREB in primary cultures of bovine aortic VSMC and explored the relationship between signaling to the cytoprotective CREB and the activating mitogen-activated protein kinase pathways. In vitro exposure of VSMC to 3 classes of unsaturated NEFA leads to significant acute, transient, dose-dependent, and repeatedly inducible CREB activation. As expected, extracellular signal-regulated kinase, P38 mitogen-activated protein kinase, Akt, Jun N-terminal kinase, and protein kinase C (PKC) pathways are also activated by NEFA. Using a battery of pharmacologic inhibitors and antioxidants, we demonstrate that CREB activation is mediated by a novel PKC isoform and is reactive oxygen species independent, whereas extracellular signal-regulated kinase activation, in contrast, is mediated by reactive oxygen species and is PKC independent. These data suggest parallel and mechanistically distinct stimulation of separate stabilizing and activating pathways in VSMC response to acute NEFA-mediated stress. Furthermore, the down-regulation of CREB in models of chronic metabolic stress reported in the literature would be expected to disrupt this homeostasis and shift the balance toward VSMC activation, consistent with emerging models of atherosclerosis.
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Affiliation(s)
- Irene E Schauer
- Denver Research Institute, Denver Veterans Administration Medical Center, Denver, CO 80220, USA
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Abstract
Accumulating evidence supports the importance of redox signaling in the pathogenesis and progression of hypertension. Redox signaling is implicated in many different physiological and pathological processes in the vasculature. High blood pressure is in part determined by elevated total peripheral vascular resistance, which is ascribed to dysregulation of vasomotor function and structural remodeling of blood vessels. Aberrant redox signaling, usually induced by excessive production of reactive oxygen species (ROS) and/or by decreases in antioxidant activity, can induce alteration of vascular function. ROS increase vascular tone by influencing the regulatory role of endothelium and by direct effects on the contractility of vascular smooth muscle. ROS contribute to vascular remodeling by influencing phenotype modulation of vascular smooth muscle cells, aberrant growth and death of vascular cells, cell migration, and extracellular matrix (ECM) reorganization. Thus, there are diverse roles of the vascular redox system in hypertension, suggesting that the complexity of redox signaling in distinct spatial spectrums should be considered for a better understanding of hypertension.
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Affiliation(s)
- Moo Yeol Lee
- Department of Medicine, Division of Cardiology, Emory University, Atlanta, Georgia 30322, USA
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Protein kinase C protects from DNA damage-induced necrotic cell death by inhibiting poly(ADP-ribose) polymerase-1. FEBS Lett 2008; 582:1672-8. [PMID: 18439913 DOI: 10.1016/j.febslet.2008.04.023] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2008] [Revised: 04/11/2008] [Accepted: 04/13/2008] [Indexed: 11/23/2022]
Abstract
The goal of the current study, conducted in freshly isolated thymocytes was (1) to investigate the possibility that the activation of poly(ADP-ribose) polymerase-1 (PARP-1) in an intact cell can be regulated by protein kinase C (PKC) mediated phosphorylation and (2) to examine the consequence of this regulatory mechanism in the context of cell death induced by the genotoxic agent. In cells stimulated by the PKC activating phorbol esters, DNA breakage was unaffected, PARP-1 was phosphorylated, 1-methyl-3-nitro-1-nitrosoguanidine-induced PARP activation and cell necrosis were suppressed, with all these effects attenuated by the PKC inhibitors GF109203X or Gö6976. Inhibition of cellular PARP activity by PKC-mediated phosphorylation may provide a plausible mechanism for the previously observed cytoprotective effects of PKC activators.
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Churchill E, Budas G, Vallentin A, Koyanagi T, Mochly-Rosen D. PKC isozymes in chronic cardiac disease: possible therapeutic targets? Annu Rev Pharmacol Toxicol 2008; 48:569-99. [PMID: 17919087 DOI: 10.1146/annurev.pharmtox.48.121806.154902] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cardiovascular disease is the leading cause of death in the United States. Therefore, identifying therapeutic targets is a major focus of current research. Protein kinase C (PKC), a family of serine/threonine kinases, has been identified as playing a role in many of the pathologies of heart disease. However, the lack of specific PKC regulators and the ubiquitous expression and normal physiological functions of the 11 PKC isozymes has made drug development a challenge. Here we discuss the validity of therapeutically targeting PKC, an intracellular signaling enzyme. We describe PKC structure, function, and distribution in the healthy and diseased heart, as well as the development of rationally designed isozyme-selective regulators of PKC functions. The review focuses on the roles of specific PKC isozymes in atherosclerosis, fibrosis, and cardiac hypertrophy, and examines principles of pharmacology as they pertain to regulators of signaling cascades associated with these diseases.
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Affiliation(s)
- Eric Churchill
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305-5174, USA
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Ardanaz N, Beierwaltes WH, Pagano PJ. Comparison of H2O2-induced vasoconstriction in the abdominal aorta and mesenteric artery of the mouse. Vascul Pharmacol 2007; 47:288-94. [PMID: 17900993 DOI: 10.1016/j.vph.2007.08.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2007] [Revised: 08/07/2007] [Accepted: 08/22/2007] [Indexed: 10/22/2022]
Abstract
Hydrogen peroxide (H(2)O(2)) is generally perceived as an arterial vasodilator. Due to the emerging importance of H(2)O(2) as a possible vasoconstrictor, we examined whether H(2)O(2) constricts both the abdominal aorta and superior mesenteric artery and postulated that H(2)O(2) is a ubiquitous constrictor of quiescent mouse arteries. Moreover, we postulated that KCl depolarization discloses and/or exaggerates H(2)O(2)-induced constriction. Under quiescent conditions, H(2)O(2) constricted the mouse abdominal aorta but not the mesenteric artery. Vessel depolarization (a) exaggerated this constrictor response in the aorta, and (b) unmasked a contractile response in the mesenteric artery. Our final hypothesis tested whether tyrosine kinases, mitogen-activated protein kinases (MAPKs), and/or Rho-kinase are uniformly involved in H(2)O(2)-induced vasoconstriction. We observed a marked difference in the ability of tyrosine kinase inhibitor to block H(2)O(2)-induced vasoconstriction. p38 and ERK 1/2MAPK inhibitors reduced the maximal response to H(2)O(2), whereas JNK inhibitor had no effect. Finally, Rho-kinase inhibitor decreased the H(2)O(2) response in the mesenteric artery but not in the aorta. These data demonstrate a variable yet tightly regulated H(2)O(2) vasoconstrictor effect. Furthermore, we found that p38, ERK 1/2 and Rho-kinase play a role in H(2)O(2) constriction, which may be critical pathways involved in H(2)O(2)-induced constriction across vascular beds.
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Affiliation(s)
- Noelia Ardanaz
- Hypertension and Vascular Research Division, Henry Ford Health System, Detroit, MI 48202-2689, USA
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Effect of cigarette smoke extract on proliferation of rat pulmonary artery smooth muscle cells and the relevant roles of protein kinase C. Chin Med J (Engl) 2007. [DOI: 10.1097/00029330-200709010-00011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Heeneman S, Donners MMPC, Bai L, Daemen MJAP. Drug-induced immunomodulation to affect the development and progression of atherosclerosis: a new opportunity? Expert Rev Cardiovasc Ther 2007; 5:345-64. [PMID: 17338677 DOI: 10.1586/14779072.5.2.345] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Inflammation and cytokine pathways are crucial for the development and progression of atherosclerotic lesions. In this review, the hypothesis that immunomodulatory drugs provide a possible therapeutic modality for cardiovascular disease is evaluated. Therefore, after a short overview of the specific inflammatory pathways involved in atherosclerosis, literature on the effect of several immunomodulatory drugs, such as nonsteroidal anti-inflammatory drugs, specific cyclooxygenase inhibitors and immunosuppressive drugs, used currently in the prevention of rejection after organ transplant, on the development and progression of atherosclerosis is reviewed. In addition, the pleiotropic immunomodulatory effect of two established cardiovascular drugs (angiotensin-converting enzyme inhibitors and statins) is discussed.
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Affiliation(s)
- Sylvia Heeneman
- University of Maastricht, Department of Pathology, Cardiovascular Research Institute Maastricht, PO Box 5800, 6202 AZ Maastricht, The Netherlands.
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Abstract
Despite the better options of controlling diabetes mellitus and although the prognosis of diabetic retinopathy has markedly improved by laser treatment and vitreoretinal surgery, diabetic retinopathy still is the leading cause of blindness in working age people in industrialized countries. Little has changed in the last decades regarding the prognosis of ocular complications in diabetes mellitus. We therefore need better tools and new therapeutic approaches for the prevention and treatment of diabetic ocular complications. Newer therapeutic options are directed at the causative mechanisms of diabetic retinopathy. Experimental and clinical evidence suggests that pharmacological compounds like somatostatin analogues and protein kinase C (PKC) inhibitors may be effective in the treatment of diabetic retinopathy. Chronic overproduction of growth hormone and insulin-like growth factor 1 play an important role in the pathogenesis of diabetic retinopathy. In the treatment of diabetic retinopathy somatostatin receptors are the targets of somatostatin analogues like octreotide. Octreotide has shown to be a promising treatment of diabetic retinopathy and diabetic macular edema. One important pathomechanism in the development of diabetic retinopathy is the activation of PKC induced by high glucose due to an increased diacylglycerol level. The selective PKC-beta inhibitor ruboxistaurin mesylate enables a new therapeutical approach for the treatment of diabetic retinopathy. Ongoing prospective clinical trials investigate whether the treatment with the specific PKC-beta inhibitor can prevent the progression of diabetic retinopathy and diabetic macular edema.
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Coyle CH, Martinez LJ, Coleman MC, Spitz DR, Weintraub NL, Kader KN. Mechanisms of H2O2-induced oxidative stress in endothelial cells. Free Radic Biol Med 2006; 40:2206-13. [PMID: 16785034 DOI: 10.1016/j.freeradbiomed.2006.02.017] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2005] [Revised: 02/10/2006] [Accepted: 02/27/2006] [Indexed: 10/24/2022]
Abstract
Hydrogen peroxide, produced by inflammatory and vascular cells, induces oxidative stress that may contribute to endothelial dysfunction. In smooth muscle cells, H(2)O(2) induces production of O(2)*(-) by activating NADPH oxidase. However, the mechanisms whereby H(2)O(2) induces oxidative stress in endothelial cells are poorly understood. We examined the effects of H(2)O(2) on O(2)*(-) levels on porcine aortic endothelial cells (PAEC). Treatment with 60 micromol/L H(2)O(2) markedly increased intracellular O(2)*(-) levels (determined by conversion of dihydroethidium to hydroxyethidium) and produced cytotoxicity (determined by propidium iodide staining) in PAEC. Overexpression of human manganese superoxide dismutase in PAEC reduced O(2)*(-) levels and attenuated cytotoxicity resulting from treatment with H(2)O(2). L-NAME, an inhibitor of nitric oxide synthase (NOS), and apocynin, an inhibitor of NADPH oxidase, reduced O(2)*(-) levels in PAEC treated with H(2)O(2), suggesting that both NOS and NADPH oxidase contribute to H(2)O(2)-induced O(2)*(-) in PAEC. Inhibition of NADPH oxidase using apocynin and NOS rescue with L-sepiapterin together reduced O(2)*(-) levels in PAEC treated with H(2)O(2) to control levels. This suggests interaction-distinct NOS and NADPH oxidase pathways to superoxide. We conclude that H(2)O(2) produces oxidative stress in endothelial cells by increasing intracellular O(2)*(-) levels through NOS and NADPH oxidase. These findings suggest a complex interaction between H(2)O(2) and oxidant-generating enzymes that may contribute to endothelial dysfunction.
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Affiliation(s)
- Christian H Coyle
- Cell and Synthetic Interface Engineering Laboratory, Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242, USA
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Muzaffar S, Shukla N, Angelini GD, Jeremy JY. Superoxide auto-augments superoxide formation and upregulates gp91phox expression in porcine pulmonary artery endothelial cells: Inhibition by iloprost. Eur J Pharmacol 2006; 538:108-14. [PMID: 16647052 DOI: 10.1016/j.ejphar.2006.03.047] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2006] [Revised: 03/15/2006] [Accepted: 03/17/2006] [Indexed: 11/23/2022]
Abstract
Central to the aetiology of Acute Respiratory Distress Syndrome (ARDS) is superoxide, the principal source of which is nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase). To test whether superoxide may influence NADPH oxidase expression directly, the effect of incubation of superoxide with porcine pulmonary arterial endothelial cells on the expression of gp91(phox) (a catalytic subunit of NADPH oxidase) and superoxide formation was investigated. Since iloprost has been purported to be potentially effective in treating ARDS, the effect of iloprost on superoxide-mediated effects was also studied. Pulmonary artery endothelial cells were incubated with xanthine/xanthine oxidase which generates superoxide, or tumour necrosis factor alpha (TNFalpha) or thromboxane A(2) analogue, U46619 (+/- superoxide dismutase [SOD] or catalase or iloprost) for 16 h. Cells were then washed and superoxide formation assessed spectrophometrically and gp91(phox) expression using Western blotting. The role of NADPH oxidase was also studied in the above settings using apocynin, an NADPH oxidase inhibitor. Superoxide, TNFalpha and U46619 elicited an increase in the formation of superoxide and induced gp91(phox) expression in pulmonary artery endothelial cells following a 16 h incubation an effect blocked by the continual presence of SOD and apocynin but not catalase. Apocynin completely inhibited superoxide formation induced with xanthine/xanthine oxidase after the 16 h incubation. Rotenone and allopurinol were without effect. Iloprost inhibited the formation of superoxide and gp91(phox) expression. These data demonstrate that superoxide upregulates gp91(phox) expression in pulmonary artery endothelial cells and thus augments superoxide formation, an effect blocked by iloprost. This constitutes a novel mechanism by which vascular superoxide creates a self-perpetuating cascade that may be of importance to the etiology of ARDS and other vasculopathies.
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Affiliation(s)
- Saima Muzaffar
- Bristol Heart Institute, University of Bristol, Bristol, UK
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Abstract
A proper rate of programmed cell death or apoptosis is required to maintain normal tissue homeostasis. In disease states such as cancer and some forms of hypertension, apoptosis is blocked, resulting in hyperplasia. In neurodegenerative diseases, uncontrolled apoptosis leads to loss of brain tissue. The flow of ions in and out of the cell and its intracellular organelles is becoming increasingly linked to the generation of many of these diseased states. This review focuses on the transport of K(+) across the cell membrane and that of the mitochondria via integral K(+)-permeable channels. We describe the different types of K(+) channels that have been identified, and investigate the roles they play in controlling the different phases of apoptosis: early cell shrinkage, cytochrome c release, caspase activation, and DNA fragmentation. Attention is also given to K(+) channels on the inner mitochondrial membrane, whose activity may underlie anti- or pro-apoptotic mechanisms in neurons and cardiomyocytes.
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Affiliation(s)
- E D Burg
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, University of California, San Diego, 9500 Gilman Drive, MC 0725, La Jolla, 92093-0725, USA
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Jung ME, Watson DG, Simpkins JW. Suppression of protein kinase Cepsilon mediates 17beta-estradiol-induced neuroprotection in an immortalized hippocampal cell line. J Neurochem 2005; 95:745-55. [PMID: 16248886 DOI: 10.1111/j.1471-4159.2005.03424.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Although estrogens are neuroprotective in a variety of neuroprotection models, the precise underlying mechanisms are currently not well understood. Here, we examined the role of protein kinase C (PKC) in mediating estrogen-induced neuroprotection in the HT-22 immortalized hippocampal cell line. The neuroprotection model utilized calcein fluorescence to quantitate cell viability following glutamate insults. 17beta-Estradiol (betaE2) protected HT-22 cells when treatment was initiated before or after the glutamate insult. The inhibition of PKC by bis-indolylmaleimide mimicked and enhanced betaE2-induced neuroprotection. In contrast, the inhibition of specific PKC isozymes (alpha and beta) by Go6976, inhibition of 1-phosphatidylinositol 3 kinase by wortmannin, or inhibition of protein kinase A by H-89, did not alter cell viability, suggesting a specific involvement of PKC in an isozyme-dependent manner. We further examined whether estrogen interacts with PKC in a PKC isozyme-specific manner. Protein levels and activity of PKC isozymes (alpha, delta, epsilon, and zeta) were assessed by western blot analysis and radiolabeled phosphorylation assays respectively. Among the isozymes tested, betaE2 altered only PKCepsilon; it reduced the activity and membrane translocation of PKCepsilon in a manner that correlated with its protection against glutamate toxicity. Furthermore, betaE2 reversed the increased activity of membrane PKCepsilon induced by glutamate. These data suggest that the neuroprotective effects of estrogens are mediated in part by inhibition of PKCepsilon activity and membrane translocation.
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Affiliation(s)
- Marianna E Jung
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas 76107, USA.
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Ryer EJ, Sakakibara K, Wang C, Sarkar D, Fisher PB, Faries PL, Kent KC, Liu B. Protein kinase C delta induces apoptosis of vascular smooth muscle cells through induction of the tumor suppressor p53 by both p38-dependent and p38-independent mechanisms. J Biol Chem 2005; 280:35310-7. [PMID: 16118209 DOI: 10.1074/jbc.m507187200] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Apoptotic death of vascular smooth muscle cells (SMCs) is a prominent feature of blood vessel remodeling. In the present study, we examined the novel PKC isoform protein kinase C delta (PKCdelta) and its role in vascular SMC apoptosis. In A10 SMCs, overexpression of PKCdelta was sufficient to induce apoptosis, whereas inhibition of PKCdelta diminished H2O2-induced apoptosis. Moreover, evidence is provided that the tumor suppressor p53 is an essential mediator of PKCdelta-induced apoptosis in SMCs. Activation of PKCdelta led to accumulation as well as phosphorylation of p53 in SMCs; this induction correlated with apoptosis. Furthermore, blocking p53 induction with small interference RNA or targeted gene deletion prevented PKCdelta-induced apoptosis, whereas restoring p53 expression rescued the ability of PKCdelta to induce apoptosis in p53 null SMCs. We also establish that PKCdelta regulates p53 at both transcriptional and post-translational levels. Specifically, the transcriptional regulation required p38 MAPK, whereas the post-translational modification, at least for serine 46, did not involve MAPK. Additionally, PKCdelta, p38 MAPK, and p53 co-associate in cells under conditions favoring apoptosis. Together, our data suggest that SMC apoptosis proceeds through a pathway that involves PKCdelta, the intermediary p38 MAPK, and the downstream target tumor suppressor p53.
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Affiliation(s)
- Evan J Ryer
- Department of Surgery, Division of Vascular Surgery, New York Presbyterian Hospital and Weill Medical College, Cornell University, New York, New York 10021, USA
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Park WS, Son YK, Han J, Kim N, Ko JH, Bae YM, Earm YE. Staurosporine inhibits voltage-dependent K+ current through a PKC-independent mechanism in isolated coronary arterial smooth muscle cells. J Cardiovasc Pharmacol 2005; 45:260-9. [PMID: 15725952 DOI: 10.1097/01.fjc.0000154370.57789.fe] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We examined the effects of the protein kinase C (PKC) inhibitor staurosporine (ST) on voltage-dependent K (KV) channels in rabbit coronary arterial smooth muscle cells. ST inhibited the KV current in a dose-dependent manner with a Kd value of 1.3 microM. The inhibition of the KV current by ST was voltage-dependent between -30 and +10 mV. The additive inhibition of the KV current by ST was voltage-dependent throughout the activation voltage range. The rate constants of association and dissociation of ST were 0.63 microM s and 0.92 s, respectively. ST produced use-dependent inhibition of the KV current. ST shifted the activation curve to more positive potentials but did not have any significant effect on the voltage dependence of the inactivation curve. ST did not have any significant effects on other types of K channel. Another PKC inhibitor, chelerythrine, and PKA inhibitor peptide (PKA-IP) had little effect on the KV current. These results suggest that ST interacts with KV channels that are in the closed state and that ST inhibits KV channels in the open state in a manner that is phosphorylation-independent and voltage-, time-, and use-dependent.
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Affiliation(s)
- Won Sun Park
- Department of Physiology and National Research Laboratory for Cellular Signaling, Seoul National University College of Medicine, Seoul, Korea
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Korzick DH, Rishel ME, Bowles DK. Exercise and hypercholesterolemia produce disparate shifts in coronary PKC expression. Med Sci Sports Exerc 2005; 37:381-8. [PMID: 15741835 DOI: 10.1249/01.mss.0000155698.76417.4c] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Sedentary lifestyle and high-fat, high-cholesterol diets are each associated with elevated risk for coronary heart disease (CHD); however, the mechanisms by which they increase risk are unclear. Specific PKC isoforms have been implicated in the development of CHD, regulation of coronary vasoreactivity, as well as exercise-induced cardioprotection. Thus, diet and physical inactivity may increase CHD risk by altering coronary protein kinase C (PKC) isoform profiles. PURPOSE To determine whether coronary PKC isoform profiles are altered in a model of early CHD and whether exercise can prevent these changes. METHODS Male and female Yucatan miniature swine were either fed a normal (NF) or high-fat (HF) diet (8 vs 46% kilocalories from fat) and remained sedentary (Sed) or were treadmill-trained (Ex) at 75% of; VO2max (6 mph, 60 min) for 16 wk. Groups were as follows: NFSed (N=8/N=7), NFEx (N=8/N=7), HFSed (N=8/N=7), and HFEx (N=8/N=7). Western blotting was performed on right coronary conduit artery (CCA) segments (>1 mm I.D.) to measure total protein levels of PKC-alpha, -betaI, -betaII, -delta, -epsilon, and -zeta. RESULTS HF diet increased total cholesterol by more than sixfold with no increase in triglycerides. Hypercholesterolemia increased PKC-betaII and -epsilon protein levels in CCA of both male and female pig; Ex had no effect on this response. Ex-induced increases in PKC-betaI, PKC-delta, and PKC-zeta were observed in HF male pigs. Female pigs had higher baseline amounts of PKC-alpha (25%), PKC-betaI (33%), PKC-betaII (39%), and PKC-epsilon (29%), whereas male pigs had higher amounts of PKC-delta (308%). Further analyses revealed a direct relationship between androgens and PKC-delta levels. CONCLUSION Hypercholesterolemia and exercise exert disparate effects on coronary PKC expression. Observed sex differences in PKC protein profiles may also contribute to altered cardiovascular risk patterns in males versus females.
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Affiliation(s)
- Donna H Korzick
- Noll Physiological Research Center, Intercollege Program in Physiology, The Penn State University, University Park, PA 16802, USA.
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Abstract
Protein kinase C (PKC) is a member of a large family of serine/threonine kinases that plays an integral role in many of the signaling cascades that govern cellular behavior. As such, it is intricately involved in the processes that mediate disease pathogenesis. Strategies that serve to alter PKC function may prove to be useful in the treatment of numerous disease states. This article reviews the various roles PKC may play in cardiovascular disease, specifically with regard to ischemic heart disease, cardiac hypertrophy, heart failure, hypertension, and atherosclerosis, and suggests the potential for developing therapeutic approaches that can target PKC activity.
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Affiliation(s)
- Stephen Murphy
- Department of Internal Medicine, University of Colorado School of Medicine, Denver, CO, USA
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46
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Abstract
Chronic overproduction of growth hormone and insulin-like growth factor 1 play an important role in the pathogenesis of diabetic retinopathy. Somatostatin receptors are the targets of somatostatin analogues such as octreotide in the treatment of diabetic retinopathy. Octreotide has shown promise as a safe and effective treatment for advanced diabetic retinopathy and diabetic macular edema. One important pathomechanism in the development of diabetic complications is the activation of protein kinase C induced by high glucose due to an increased diacylglycerol level. The development of a selective PKCss inhibitor enables a new therapeutic approach for the treatment of diabetic retinopathy. Ongoing prospective clinical studies are investigating if treatment with specific PKCss inhibitors can prevent the progression of diabetic retinopathy and diabetic macular edema. The intravitreal injection of triamcinolone acetonide leads to at least temporary improvement of the diffuse diabetic macular edema. Side effects are increase of intraocular pressure, cataract, and endophthalmitis.
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Affiliation(s)
- G E Lang
- Augenklinik, Universitätsklinikum, Ulm.
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47
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Kim A, Bae YM, Kim J, Kim B, Ho WK, Earm YE, Cho SI. Direct block by bisindolylmaleimide of the voltage-dependent K+ currents of rat mesenteric arterial smooth muscle. Eur J Pharmacol 2004; 483:117-26. [PMID: 14729098 DOI: 10.1016/j.ejphar.2003.10.028] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We investigated the effect of bisindolylmaleimide (I), a widely used protein kinase C (PKC) inhibitor, on the voltage-dependent K(+) (Kv) currents of rat mesenteric arterial smooth muscle cells using the whole-cell patch-clamp technique. Bisindolylmaleimide (I) reversibly and dose-dependently inhibited the Kv currents with an apparent K(d) value of 0.23+/-0.001 microM. The blockade was apparently through the acceleration of the decay rate of the Kv currents. The apparent rate constants of association and dissociation for bisindolylmaleimide (I) were 17.9+/-1.6 microM(-1) s(-1) and 4.1+/-1.5 s(-1), respectively. The inhibition of Kv current by bisindolylmaleimide (I) was steeply voltage-dependent between -30 and 0 mV (voltage range of channel activation). Bisindolylmaleimide (I) had no effect on the steady-state activation and inactivation of the Kv currents. Applications of trains of pulses at 1 or 2 Hz lead to a progressive increase in the bisindolylmaleimide (I)-blockade, and the recovery from bisindolylmaleimide (I)-block at -80 mV exhibited a time constant of 577.2+/-52.7 ms. Bisindolylmaleimide (V), an inactive analogue of bisindolylmaleimide (I), similarly inhibited the Kv currents with an apparent K(d) value of 1.48+/-0.004 microM, but other PKC inhibitor chelerythrine little affected the Kv currents. These results suggest that bisindolylmaleimide (I) directly inhibits the Kv currents of rat mesenteric arterial smooth muscle cells independently of PKC inhibition, in a state-, voltage-, time- and use-dependent manner.
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Affiliation(s)
- Aeran Kim
- Department of Physiology, College of Medicine, Konkuk University, 322 Danwol-dong, Choongju 380-701, South Korea
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48
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Abstract
Zinc is an important component of proteins essential for normal functioning of the brain. However, it has been shown in vitro that this metal, at elevated levels, can be toxic to cells leading to their death. We investigated possible mechanisms of cell death caused by zinc: firstly, generation of reactive oxygen species, and secondly, the activation of the MAP-kinase pathway. Cell viability was assessed by means of the methyl-thiazolyl tetrazolium salt (MTT) assay and confirmed by tetramethylrhodamine methyl ester (TMRM) staining. We measured the phosphorylation status of Erk and p38 as indicators of MAP-kinase activity, using Western Blot techniques. A time curve was established when neuroblastoma (N2alpha) cells were exposed to 100 microM of zinc for 4, 12, and 24 h. Zinc caused a significant reduction in cell viability as early as 4 h, and indirectly stimulated the accumulation of reactive oxygen species as determined by 2.7 dichlorodihydrofluorescein diacetate (DCDHF) staining and confocal microscopy. Investigation of the MAP-kinase pathway indicated that Erk was downregulated, while p38 was stimulated. Our results therefore led us to conclude that in vitro, zinc toxicity involved the generation of reactive oxygen species and the activation of the MAP-kinase pathway.
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Affiliation(s)
- Willie M U Daniels
- Department of Medical Physiology, University of Stellenbosch, Tygerberg, South Africa.
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49
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Sandberg EM, Sayeski PP. Jak2 tyrosine kinase mediates oxidative stress-induced apoptosis in vascular smooth muscle cells. J Biol Chem 2004; 279:34547-52. [PMID: 15159394 DOI: 10.1074/jbc.m405045200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In vascular smooth muscle cells, Jak2 tyrosine kinase becomes activated in response to oxidative stress in the form of hydrogen peroxide. Although it has been postulated that hydrogen peroxide-induced Jak2 activation promotes cell survival, this has never been tested. We therefore examined the role that Jak2 plays in vascular smooth muscle cell apoptosis following hydrogen peroxide treatment. Here, we report that Jak2 tyrosine kinase activation by hydrogen peroxide is required for apoptosis of vascular smooth muscle cells. Upon treatment of primary rat aortic smooth muscle cells with hydrogen peroxide, we observed laddering of genomic DNA and nuclear condensation, both hallmarks of apoptotic cells. However, apoptosis was prevented by either the expression of a dominant negative Jak2 protein or by the Jak2 pharmacological inhibitor AG490. Moreover, expression of the proapoptotic Bax protein was induced following hydrogen peroxide treatment. Again, expression of a dominant negative Jak2 protein or treatment of cells with AG490 prevented this Bax induction. Following Bax induction by hydrogen peroxide, mitochondrial membrane integrity was compromised, and caspase-9 became activated. In contrast, in cells expressing a Jak2 dominant negative we observed that mitochondrial membrane integrity was preserved, and no caspase-9 activation occurred. These data demonstrate that the activation of Jak2 tyrosine kinase by hydrogen peroxide is essential for apoptosis of vascular smooth muscle cells. Furthermore, this report identifies Jak2 as a potential therapeutic target in vascular diseases in which vascular smooth muscle cell apoptosis contributes to pathological progression.
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Affiliation(s)
- Eric M Sandberg
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL 32610, USA
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50
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Zohlnhöfer D, Nührenberg TG, Neumann FJ, Richter T, May AE, Schmidt R, Denker K, Clauss MA, Schömig A, Baeuerle PA. Rapamycin effects transcriptional programs in smooth muscle cells controlling proliferative and inflammatory properties. Mol Pharmacol 2004; 65:880-9. [PMID: 15044617 DOI: 10.1124/mol.65.4.880] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Neointima formation, the leading cause of restenosis, is caused by proliferation of coronary artery smooth muscle cells (CASMCs) and is associated with infiltration by monocytes. Rapamycin inhibits neointima formation after stent implantation in humans. It reduces proliferation by its effects on mammalian target of rapamycin (mTOR) kinase. In this study, we investigated the expression of mTOR in human neointima and the effect of rapamycin on global transcriptional events controlling CASMC phenotype. In neointimal CASMCs, mTOR exhibited increased phosphorylation and was translocated to the nucleus compared with control. Comparative gene expression analysis of CASMCs treated with rapamycin (100 ng/ml) revealed down-regulation of the transcription factor E2F-1, a key regulator of G(1)/S-phase entry, and of various retinoblastoma protein/E2F-1-regulated genes. In addition, we found changes in the expression of genes associated with replication, apoptosis, and extracellular matrix formation. Furthermore, rapamycin decreased the gene expression of endothelial monocyte-activating polypeptide-II (EMAP-II). This decrease of EMAP-II expression was reflected in a reduced adhesiveness of CASMCs for monocytic cells. Addition of EMAP-II counteracted the antiadhesive effect of rapamycin. Therefore, EMAP-II may comprise a mechanism of rapamycin-mediated reduction of the proinflammatory activation of CASMCs. The effects reported here of rapamycin on the down-regulation of genes involved in cell cycle progression, apoptosis, proliferation, and extracellular matrix formation in CASMCs provide an explanation of how rapamycin reduces CASMC proliferation. In addition, rapamycin may contribute to a reduction of inflammatory responses by reducing the adhesiveness of CASMC, a mechanism suggested to be mediated by the production and release of EMAP II.
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