1
|
Swierczynski M, Kasprzak Z, Makaro A, Salaga M. Regulators of G-Protein Signaling (RGS) in Sporadic and Colitis-Associated Colorectal Cancer. Int J Mol Sci 2024; 25:577. [PMID: 38203748 PMCID: PMC10778579 DOI: 10.3390/ijms25010577] [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: 11/13/2023] [Revised: 12/21/2023] [Accepted: 12/29/2023] [Indexed: 01/12/2024] Open
Abstract
Colorectal cancer (CRC) is one of the most common neoplasms worldwide. Among the risk factors of CRC, inflammatory bowel disease (IBD) is one of the most important ones leading to the development of colitis-associated CRC (CAC). G-protein coupled receptors (GPCR) are transmembrane receptors that orchestrate a multitude of signaling cascades in response to external stimuli. Because of their functionality, they are promising targets in research on new strategies for CRC diagnostics and treatment. Recently, regulators of G-proteins (RGS) have been attracting attention in the field of oncology. Typically, they serve as negative regulators of GPCR responses to both physiological stimuli and medications. RGS activity can lead to both beneficial and harmful effects depending on the nature of the stimulus. However, the atypical RGS-AXIN uses its RGS domain to antagonize key signaling pathways in CRC development through the stabilization of the β-catenin destruction complex. Since AXIN does not limit the efficiency of medications, it seems to be an even more promising pharmacological target in CRC treatment. In this review, we discuss the current state of knowledge on RGS significance in sporadic CRC and CAC with particular emphasis on the regulation of GPCR involved in IBD-related inflammation comprising opioid, cannabinoid and serotonin receptors.
Collapse
Affiliation(s)
| | | | | | - Maciej Salaga
- Department of Biochemistry, Faculty of Medicine, Medical University of Lodz, Mazowiecka 5, 92-215 Lodz, Poland; (M.S.); (Z.K.); (A.M.)
| |
Collapse
|
2
|
Li L, Zheng B, Zhang F, Luo X, Li F, Xu T, Zhao H, Shi G, Guo Y, Shi J, Sun J. LINC00370 modulates miR-222-3p-RGS4 axis to protect against osteoporosis progression. Arch Gerontol Geriatr 2021; 97:104505. [PMID: 34450404 DOI: 10.1016/j.archger.2021.104505] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 08/09/2021] [Accepted: 08/09/2021] [Indexed: 11/18/2022]
Abstract
BACKGROUND We aimed to determine the role of the LINC00370/miR-222-3p/RGS4 axis in modulating the process of adipose-derived stem cell (ADSC) osteogenic differentiation. METHODS We first evaluated the differential expression of LINC00370, miR-222-3p and RGS4 between normal and osteogenically induced ADSCs. Moreover, we transfected ADSCs with LINC00370 siRNA and an miR-222-3p inhibitor to determine the role of LINC00370 in modulating the process of ADSC osteogenic differentiation. Finally, we analyzed the dual-luciferase reporter gene to identify the relationship between LINC00370 and miR-222-3p. We first created osteoporotic rat models by ovariectomy (OVX) and treated with pcDNA-LINC00370. HE and immunohistochemical staining of OCN were performed to assess the changes in bone microarchitecture. RESULTS LINC00370 and RGS4 expression was remarkably upregulated in the osteogenic ADSC group compared with the normal medium group. On the other hand, miR-222-3p expression was remarkably decreased in the osteogenic group compared with the normal medium group. Knockdown of LINC00370 reduced the osteogenic differentiation of ADSCs. Moreover, the inhibitor of miR-222-3p partially reversed the reduction of osteogenic differentiation by LINC00370 knockdown. Knockdown of LINC00370 reduced the expression of p-Akt and p-PI3K. The inhibitor of miR-222-3p partially reversed the reduction of the expression of p-Akt and p-PI3K by LINC00370 knockdown. A dual luciferase reporter assay indicated that LINC00370 can directly bind miR-222-3p. LINC00370 suppressed OP progression in OVX and partially upregulated OCN protein expression. CONCLUSION Collectively, the above results confirm that LINC00370 promotes the process of ADSC osteogenic differentiation via the miR-222-3p/RGS4 axis. Moreover, LINC00370 could protect against OVX-induced OP.
Collapse
Affiliation(s)
- Lintao Li
- Department of Orthopedic Surgery, Jinling Hospital, Nanjing University, Nanjing, China
| | - Bing Zheng
- Department of Spine Surgery, Changzheng Hospital, Second Military Medical University, No.415 Fengyang Road, Shanghai 200001, China
| | - Fan Zhang
- Department of Spine Surgery, Changzheng Hospital, Second Military Medical University, No.415 Fengyang Road, Shanghai 200001, China
| | - Xi Luo
- Department of Spine Surgery, Changzheng Hospital, Second Military Medical University, No.415 Fengyang Road, Shanghai 200001, China
| | - Fudong Li
- Department of Spine Surgery, Changzheng Hospital, Second Military Medical University, No.415 Fengyang Road, Shanghai 200001, China
| | - Tao Xu
- Department of Orthopedic Surgery, No. 906 Hospital of the People's Liberation Army, Zhejiang, China
| | - Hong Zhao
- Department of Orthopedic Surgery, No. 906 Hospital of the People's Liberation Army, Zhejiang, China
| | - Guodong Shi
- Department of Spine Surgery, Changzheng Hospital, Second Military Medical University, No.415 Fengyang Road, Shanghai 200001, China
| | - Yongfei Guo
- Department of Spine Surgery, Changzheng Hospital, Second Military Medical University, No.415 Fengyang Road, Shanghai 200001, China
| | - Jiangang Shi
- Department of Spine Surgery, Changzheng Hospital, Second Military Medical University, No.415 Fengyang Road, Shanghai 200001, China.
| | - Jingchuan Sun
- Department of Spine Surgery, Changzheng Hospital, Second Military Medical University, No.415 Fengyang Road, Shanghai 200001, China.
| |
Collapse
|
3
|
β-Catenin Regulates Wound Healing and IL-6 Expression in Activated Human Astrocytes. Biomedicines 2020; 8:biomedicines8110479. [PMID: 33171974 PMCID: PMC7694627 DOI: 10.3390/biomedicines8110479] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 10/29/2020] [Accepted: 11/03/2020] [Indexed: 02/06/2023] Open
Abstract
Reactive astrogliosis is prominent in most neurodegenerative disorders and is often associated with neuroinflammation. The molecular mechanisms regulating astrocyte-linked neuropathogenesis during injury, aging and human immunodeficiency virus (HIV)-associated neurocognitive disorders (HAND) are not fully understood. In this study, we investigated the implications of the wingless type (Wnt)/β-catenin signaling pathway in regulating astrocyte function during gliosis. First, we identified that HIV-associated inflammatory cytokines, interleukin (IL)-1β and tumor necrosis factor (TNF)-α induced mediators of the Wnt/β-catenin pathway including β-catenin and lymphoid enhancer-binding factor (LEF)-1 expression in astrocytes. Next, we investigated the regulatory role of β-catenin on primary aspects of reactive astrogliosis, including proliferation, migration and proinflammatory responses, such as IL-6. Knockdown of β-catenin impaired astrocyte proliferation and migration as shown by reduced cyclin-D1 levels, bromodeoxyuridine incorporation and wound healing. HIV-associated cytokines, IL-1β alone and in combination with TNF-α, strongly induced the expression of proinflammatory cytokines including C-C motif chemokine ligand (CCL)2, C-X-C motif chemokine ligand (CXCL)8 and IL-6; however, only IL-6 levels were regulated by β-catenin as demonstrated by knockdown and pharmacological stabilization. In this context, IL-6 levels were negatively regulated by β-catenin. To better understand this relationship, we examined the crossroads between β-catenin and nuclear factor (NF)-κB pathways. While NF-κB expression was significantly increased by IL-1β and TNF-α, NF-κB levels were not affected by β-catenin knockdown. IL-1β treatment significantly increased glycogen synthase kinase (GSK)-3β phosphorylation, which inhibits β-catenin degradation. Further, pharmacological inhibition of GSK-3β increased nuclear translocation of both β-catenin and NF-κB p65 into the nucleus in the absence of any other inflammatory stimuli. HIV+ human astrocytes show increased IL-6, β-catenin and NF-κB expression levels and are interconnected by regulatory associations during HAND. In summary, our study demonstrates that HIV-associated inflammation increases β-catenin pathway mediators to augment activated astrocyte responses including migration and proliferation, while mitigating IL-6 expression. These findings suggest that β-catenin plays an anti-inflammatory role in activated human astrocytes during neuroinflammatory pathologies, such as HAND.
Collapse
|
4
|
Hu L, He F, Huang M, Zhao Q, Cheng L, Said N, Zhou Z, Liu F, Dai YS. SPARC promotes insulin secretion through down-regulation of RGS4 protein in pancreatic β cells. Sci Rep 2020; 10:17581. [PMID: 33067534 PMCID: PMC7567887 DOI: 10.1038/s41598-020-74593-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 10/05/2020] [Indexed: 02/06/2023] Open
Abstract
SPARC-deficient mice have been shown to exhibit impaired glucose tolerance and insulin secretion, but the underlying mechanism remains unknown. Here, we showed that SPARC enhanced the promoting effect of Muscarinic receptor agonist oxotremorine-M on insulin secretion in cultured mouse islets. Overexpression of SPARC down-regulated RGS4, a negative regulator of β-cell M3 muscarinic receptors. Conversely, knockdown of SPARC up-regulated RGS4 in Min6 cells. RGS4 was up-regulated in islets from sparc -/- mice, which correlated with decreased glucose-stimulated insulin secretion (GSIS). Furthermore, inhibition of RGS4 restored GSIS in the islets from sparc -/- mice, and knockdown of RGS4 partially decreased the promoting effect of SPARC on oxotremorine-M-stimulated insulin secretion. Phosphoinositide 3-kinase (PI3K) inhibitor LY-294002 abolished SPARC-induced down-regulation of RGS4. Taken together, our data revealed that SPARC promoted GSIS by inhibiting RGS4 in pancreatic β cells.
Collapse
Affiliation(s)
- Li Hu
- Department of Metabolism and Endocrinology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.,National Clinical Research Center for Metabolic Disease, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.,Metabolic Syndrome Research Center, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Fengli He
- Department of Metabolism and Endocrinology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.,National Clinical Research Center for Metabolic Disease, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.,Metabolic Syndrome Research Center, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Meifeng Huang
- Department of Metabolism and Endocrinology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.,National Clinical Research Center for Metabolic Disease, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.,Metabolic Syndrome Research Center, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Qian Zhao
- Institute of Reproductive and Stem Cell Engineering, Central South University, Changsha, Hunan, China
| | - Lamei Cheng
- Institute of Reproductive and Stem Cell Engineering, Central South University, Changsha, Hunan, China
| | - Neveen Said
- Department of Cancer Biology, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Zhiguang Zhou
- Department of Metabolism and Endocrinology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.,National Clinical Research Center for Metabolic Disease, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.,Metabolic Syndrome Research Center, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Feng Liu
- Department of Metabolism and Endocrinology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.,National Clinical Research Center for Metabolic Disease, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.,Metabolic Syndrome Research Center, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.,Department of Pharmacology, University of Texas Health Science Center, San Antonio, TX, USA
| | - Yan-Shan Dai
- Department of Metabolism and Endocrinology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China. .,National Clinical Research Center for Metabolic Disease, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China. .,Metabolic Syndrome Research Center, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China. .,Bristol-Myers Squibb Company, Princeton, NJ, USA.
| |
Collapse
|
5
|
Liu S, Jiang X, Lu H, Xing M, Qiao Y, Zhang C, Zhang W. HuR (Human Antigen R) Regulates the Contraction of Vascular Smooth Muscle and Maintains Blood Pressure. Arterioscler Thromb Vasc Biol 2020; 40:943-957. [PMID: 32075416 DOI: 10.1161/atvbaha.119.313897] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
OBJECTIVE HuR (human antigen R)-an RNA-binding protein-is involved in regulating mRNA stability by binding adenylate-uridylate-rich elements. This study explores the role of HuR in the regulation of smooth muscle contraction and blood pressure. Approach and Results: Vascular HuRSMKO (smooth muscle-specific HuR knockout) mice were generated by crossbreeding HuRflox/flox mice with α-SMA (α-smooth muscle actin)-Cre mice. As compared with CTR (control) mice, HuRSMKO mice showed hypertension and cardiac hypertrophy. HuR levels were decreased in aortas from hypertensive patients and SHRs (spontaneously hypertensive rats), and overexpression of HuR could lower the blood pressure of SHRs. Contractile response to vasoconstrictors was increased in mesenteric artery segments isolated from HuRSMKO mice. The functional abnormalities in HuRSMKO mice were attributed to decreased mRNA and protein levels of RGS (regulator of G-protein signaling) protein(s) RGS2, RGS4, and RGS5, which resulted in increased intracellular calcium increase. Consistently, the degree of intracellular calcium ion increase in HuR-deficient smooth muscle cells was reduced by overexpression of RGS2, RGS4, or RGS5. Finally, administration of RGS2 and RGS5 reversed the elevated blood pressure in HuRSMKO mice. CONCLUSIONS Our findings indicate that HuR regulates vascular smooth muscle contraction and maintains blood pressure by modulating RGS expression.
Collapse
Affiliation(s)
- Shanshan Liu
- From the Department of Cardiology, The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine (S.L., H.L., C.Z., W.Z.), Qilu Hospital of Shandong University, Jinan, China
| | - Xiuxin Jiang
- Department of General Surgery (X.J.), Qilu Hospital of Shandong University, Jinan, China
| | - Hanlin Lu
- From the Department of Cardiology, The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine (S.L., H.L., C.Z., W.Z.), Qilu Hospital of Shandong University, Jinan, China
| | - Mengdan Xing
- Department of Cognitive Neuroscience, The Key Laboratory of MOE for Modern Teaching Technology, Center for Teacher Professional Ability Development, Shaanxi Normal University, Xi'an, China (M.X., Y.Q.)
| | - Yanning Qiao
- Department of Cognitive Neuroscience, The Key Laboratory of MOE for Modern Teaching Technology, Center for Teacher Professional Ability Development, Shaanxi Normal University, Xi'an, China (M.X., Y.Q.)
| | - Cheng Zhang
- From the Department of Cardiology, The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine (S.L., H.L., C.Z., W.Z.), Qilu Hospital of Shandong University, Jinan, China
| | - Wencheng Zhang
- From the Department of Cardiology, The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese National Health Commission and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular Medicine (S.L., H.L., C.Z., W.Z.), Qilu Hospital of Shandong University, Jinan, China
| |
Collapse
|
6
|
Bao MH, Lv QL, Szeto V, Wong R, Zhu SZ, Zhang YY, Feng ZP, Sun HS. TRPM2-AS inhibits the growth, migration, and invasion of gliomas through JNK, c-Jun, and RGS4. J Cell Physiol 2019; 235:4594-4604. [PMID: 31637708 DOI: 10.1002/jcp.29336] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 09/30/2019] [Indexed: 01/05/2023]
Abstract
Gliomas are a group of brain cancers with high mortality and morbidity. Understanding the molecular mechanisms is important for the prevention or treatment of gliomas. The present study was to investigate the effects and mechanisms of long noncoding RNA TRPM2-AS in gliomas proliferation, migration, and invasion. We first compared the levels of TRPM2-AS in 111 patients with glioma to that of the normal control group by a quantitative polymerase chain reaction. The results indicated a significant increase of TRPM2-AS in patients with glioma (2.43 folds of control, p = .0135). MTT methods, wound healing assays, transwell analysis, and clone formation analysis indicated the overexpression of TRPM2-AS promoted the proliferation, migration, and invasion of U251 and U87 cells, while downregulation of TRPM2-AS inhibited the cell proliferation, migration, and invasion significantly (p < .05). To further uncover the mechanisms, bioinformatics analysis was conducted on the expression profiles, GSE40687 and GSE4290, from the Gene Expression Omnibus database. One hundred fifty-six genes were differentially expressed in both datasets (FC > 2.0; p = .05). Among these differentially expressed genes, the level of RGS4 messenger RNA was drastically regulated by TRPM2-AS. Further western-blot analysis indicated the increase of RGS4 protein expression and decrease of p-JNK/JNK and p-c-Jun/c-Jun ratio after TRPM2-AS overexpression. On the other hand, inhibition of TRPM2-AS by small interfering RNA suppressed the expression of RGS4 and promoted the ratios of p-JNK/JNK and p-c-Jun/c-Jun. The present work indicated the mechanisms of the participation of TRPM2-AS in the progression of gliomas might, at least partly, be related to JNK, c-Jun, and RGS4. Our work provided new insights into the underlying mechanisms of glioma cellular functions.
Collapse
Affiliation(s)
- Mei-Hua Bao
- Department of Physiology, Pathophysiology, and Pharmacology, Science Research Center, Changsha Medical University, Changsha, China.,Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Qiao-Li Lv
- Jiangxi Key Laboratory of Translational Cancer Research, Department of Head and Neck Surgery, Jiangxi Cancer Hospital, Nanchang, Jiangxi, China
| | - Vivian Szeto
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Raymond Wong
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Su-Zhen Zhu
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Ying-Ying Zhang
- Department of Oncology, Xiangya Hospital, Central South University, Changsha, China
| | - Zhong-Ping Feng
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Hong-Shuo Sun
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
7
|
PPARγ Agonist PGZ Attenuates OVA-Induced Airway Inflammation and Airway Remodeling via RGS4 Signaling in Mouse Model. Inflammation 2019; 41:2079-2089. [PMID: 30022363 DOI: 10.1007/s10753-018-0851-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Peroxisome proliferator-activated receptor-γ (PPARγ) agonist pioglitazone (PGZ) exhibits potential protective effects in asthma. Recently, regulator of G protein 4 (RGS4) has been reported to be associated with immunological and inflammatory responses. However, no evidence has shown the influence of PPARγ on RGS4 expression in airway disorders. In this study, BALB/c mice received ovalbumin (OVA) sensitization followed by OVA intranasal challenge for 90 days to establish a chronic asthma mouse model. Accompanied with OVA challenge, the mice received administration of PPARγ agonist PGZ (10 mg/kg) intragastrically or RGS4 inhibitor CCG 63802 (0.5 mg/kg) intratracheally. Invasive pulmonary function tests were performed 24 h after last challenge. Serum, bronchoalveolar lavage fluid (BALF), and lung tissues were collected for further analyses after the mice were sacrificed. We found that PPARγ agonist PGZ administration significantly attenuated the pathophysiological features of OVA-induced asthma and increased the expression of RGS4. In addition, the attenuating effect of PGZ on airway inflammation, hyperresponsiveness (AHR), and remodeling was partially abrogated by administration of RGS4 inhibitor CCG 63802. We also found that the downregulation of RGS4 by CCG 63802 also significantly increased inflammatory cell accumulation and AHR, and increased levels of IL-4, IL-13, eotaxin, IFN-γ, and IL-17A in BALF, and total and OV-specific IgE in serum. Furthermore, the inhibitory effects of PGZ on the activations of ERK and Akt/mTOR signaling, and MMPs were apparently reversed by CCG 63802 administration. In conclusion, the protective effect of PGZ on OVA-induced airway inflammation and remodeling might be partly regulated by RGS4 expression through ERK and Akt/mTOR signaling.
Collapse
|
8
|
Trans-resveratrol Inhibits Tau Phosphorylation in the Brains of Control and Cadmium Chloride-Treated Rats by Activating PP2A and PI3K/Akt Induced-Inhibition of GSK3β. Neurochem Res 2018; 44:357-373. [DOI: 10.1007/s11064-018-2683-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 11/10/2018] [Accepted: 11/13/2018] [Indexed: 10/27/2022]
|
9
|
Guo YC, Chiu YH, Chen CP, Wang HS. Interleukin-1β induces CXCR3-mediated chemotaxis to promote umbilical cord mesenchymal stem cell transendothelial migration. Stem Cell Res Ther 2018; 9:281. [PMID: 30359318 PMCID: PMC6202827 DOI: 10.1186/s13287-018-1032-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 09/07/2018] [Accepted: 09/30/2018] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Mesenchymal stem cells (MSCs) are known to home to injured and inflamed regions via the bloodstream to assist in tissue regeneration in response to signals of cellular damage. However, the factors and mechanisms that affect their transendothelial migration are still unclear. In this study, the mechanisms involved in interleukin-1β (IL-1β) enhancing the transendothelial migration of MSCs were investigated. METHODS Immunofluorescence staining and Western blotting were used to observe IL-1β-induced CXC chemokine receptor 3 (CXCR3) expression on MSCs. Quantitative real-time PCR and ELISA were used to demonstrate IL-1β upregulated both chemokine (C-X-C motif) ligand 9 (CXCL9) mRNA and CXCL9 ligand secretion in human umbilical vein endothelial cells (HUVECs). Monolayer co-cultivation, agarose drop chemotaxis, and transwell assay were conducted to investigate the chemotaxis invasion and transendothelial migration ability of IL-1β-induced MSCs in response to CXCL9. RESULTS In this study, our immunofluorescence staining showed that IL-1β induces CXCR3 expression on MSCs. This result was confirmed by Western blotting. Following pretreatment with protein synthesis inhibitor cycloheximide, we found that IL-1β induced CXCR3 on the surface of MSCs via protein synthesis pathway. Quantitative real-time PCR and ELISA validated that IL-1β upregulated both CXCL9 mRNA and CXCL9 ligand secretion in HUVECs. In response to CXCL9, chemotaxis invasion and transendothelial migration ability were increased in IL-1β-stimulated MSCs. In addition, we pretreated MSCs with CXCR3 antagonist AMG-487 and p38 MAPK inhibitor SB203580 to confirm CXCR3-CXCL9 interaction and the role of CXCR3 in IL-1β-induced chemotaxis invasion and transendothelial migration. CONCLUSION We found that IL-1β induces the expression of CXCR3 through p38 MAPK signaling and that IL-1β also enhances CXCL9 ligand secretion in HUVECs. These results indicated that IL-1β promotes the transendothelial migration of MSCs through CXCR3-CXCL9 axis. The implication of the finding could enhance the efficacy of MSCs homing to target sites.
Collapse
Affiliation(s)
- Yu-Chien Guo
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang Ming University, Peitou, Taipei, 112, Taiwan, Republic of China
| | - Yun-Hsuan Chiu
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang Ming University, Peitou, Taipei, 112, Taiwan, Republic of China
| | - Chie-Pein Chen
- Division of High Risk Pregnancy, Mackay Memorial Hospital, Taipei, Taiwan, Republic of China
| | - Hwai-Shi Wang
- Institute of Anatomy and Cell Biology, School of Medicine, National Yang Ming University, Peitou, Taipei, 112, Taiwan, Republic of China.
| |
Collapse
|
10
|
Bae JS, Lee J, Park Y, Park K, Kim JR, Cho DH, Jang KY, Park SH. Attenuation of MUC4 potentiates the anticancer activity of auranofin via regulation of the Her2/Akt/FOXO3 pathway in ovarian cancer cells. Oncol Rep 2017; 38:2417-2425. [PMID: 28765909 DOI: 10.3892/or.2017.5853] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 07/17/2017] [Indexed: 11/06/2022] Open
Abstract
Previously, we reported that auranofin induces apoptosis in SKOV3 cells via regulation of the IKKβ/FOXO3 pathway. In the present study, we reveal that the anticancer activity of auranofin in SKOV3 cells could be enhanced by the attenuation of MUC4 through the regulation of the Her2/Akt/FOXO3 pathway. Compared to the control-siRNA, siRNA transfection against MUC4 into SKOV3 cells accelerated the protein degradation of Her2. Under the same conditions, the expression level of phosphorylated Akt was also downregulated leading to an increase of FOXO3 in the nucleus. Notably, auranofin treatment in SKOV3 cells also resulted in the downregulation of the expression levels of both Her2 and phosphorylated Akt. Thus, Her2 was identified as the common molecular target protein by siRNA transfection against MUC4. Western blot analysis of total and nuclear fraction lysates from SKOV3 cells revealed that attenuation of MUC4 combined with auranofin treatment in SKOV3 cells synergistically activated FOXO3 translocation from the cytoplasm to the nucleus through the regulation of the Her2/Akt/FOXO3 pathway. Attenuation of MUC4 by siRNA transfection potentiated the antitumor effect of auranofin which was examined by performing in vitro assays such as WST-1, cell counting, colony formation, TUNEL and Annexin V staining. In addition, western blot analysis of the apoptosis‑related proteins such as PARP1, caspase-3, Bim extra large (EL), Bax and Bcl2 revealed that the attenuation of MUC4 by siRNA transfection potentiates the pro-apoptotic activity of auranofin in SKOV3 cells. Collectively, auranofin could regulate the Her2/Akt/FOXO3 signaling pathway in SKOV3 cells and be used as a potential antitumor agent considering the expression of MUC4 in ovarian cancer patients.
Collapse
Affiliation(s)
- Jun Sang Bae
- Department of Pathology, Chonbuk National University Medical School, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital and Research Institute for Endocrine Sciences, Jeonju, Republic of Korea
| | - Jongsung Lee
- Department of Genetic Engineering, Sungkyunkwan University, Suwon, Republic of Korea
| | - Yoonkook Park
- Department of Bio and Chemical Engineering, Hongik University, Sejong, Republic of Korea
| | - Kyungmoon Park
- Department of Bio and Chemical Engineering, Hongik University, Sejong, Republic of Korea
| | - Jung Ryul Kim
- Department of Orthopaedic Surgery, Chonbuk National University Medical School, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital and Research Institute for Endocrine Sciences, Jeonju, Republic of Korea
| | - Dong Hyu Cho
- Department of Obstetrics and Gynecology, Chonbuk National University Medical School, Research Institute of Clinical Medicine of Chonbuk National University- Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Republic of Korea
| | - Kyu Yun Jang
- Department of Pathology, Chonbuk National University Medical School, Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital and Research Institute for Endocrine Sciences, Jeonju, Republic of Korea
| | - See-Hyoung Park
- Department of Bio and Chemical Engineering, Hongik University, Sejong, Republic of Korea
| |
Collapse
|
11
|
Chai-Qin-Cheng-Qi Decoction and Carbachol Improve Intestinal Motility by Regulating Protein Kinase C-Mediated Ca 2+ Release in Colonic Smooth Muscle Cells in Rats with Acute Necrotising Pancreatitis. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017; 2017:5864945. [PMID: 28529530 PMCID: PMC5424168 DOI: 10.1155/2017/5864945] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 02/06/2017] [Accepted: 03/01/2017] [Indexed: 02/05/2023]
Abstract
Chai-Qin-Cheng-Qi decoction (CQCQD) improves intestinal motility in acute pancreatitis (AP), but the mechanism(s) require elucidation. We investigated the effects of CQCQD and carbachol, a prokinetic agent, on colonic smooth muscle cells (SMCs) in L-arginine-induced necrotising AP model in rats. In treatment groups, intragastric CQCQD (20 g/kg, 2 hourly × 3 doses) or intraperitoneal carbachol (60 μg/kg) was given 24 hours after induction of AP. Both CQCQD and carbachol decreased the severity of pancreatic and colonic histopathology (all P < 0.05). Both CQCQD and carbachol reduced serum intestinal fatty acid binding protein, vasoactive intestinal peptide, and substance P and increased motility levels. CQCQD upregulated SMC phospholipase C-beta 1 (PLC-β1) mRNA and PLC protein (both P < 0.05), while both treatments upregulated protein kinase C-alpha (PKC-α) mRNA and PKC protein and downregulated adenylate cyclase (AC) mRNA and protein compared with no treatment (all P < 0.05). Neither treatment significantly altered L-arginine-induced PKC-β1 and PKC-ε mRNA reduction. Both treatments significantly increased fluorescence intensity of SMC intracellular calcium concentration [Ca2+]i (3563.5 and 3046.9 versus 1086.9, both P < 0.01). These data suggest CQCQD and carbachol improve intestinal motility in AP by increasing [Ca2+]i in colonic SMCs via upregulating PLC, PKC and downregulating AC.
Collapse
|
12
|
Protective Role of Postbiotic Mediators Secreted by Lactobacillus rhamnosus GG Versus Lipopolysaccharide-induced Damage in Human Colonic Smooth Muscle Cells. J Clin Gastroenterol 2016; 50 Suppl 2, Proceedings from the 8th Probiotics, Prebiotics & New Foods for Microbiota and Human Health meeting held in Rome, Italy on September 13-15, 2015:S140-S144. [PMID: 27741159 DOI: 10.1097/mcg.0000000000000681] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Some beneficial effects of probiotics may be due to secreted probiotic-derived factors, identified as "postbiotic" mediators. The aim of this study was to evaluate whether supernatants harvested from Lactobacillus rhamnosus GG (LGG) cultures (ATCC53103 strain) protect colonic human smooth muscle cells (HSMCs) from lipopolysaccharide (LPS)-induced myogenic damage. MATERIALS AND METHODS LGG was grown in de Man, Rogosa, Share medium at 37°C and samples were collected in middle and late exponential, stationary, and overnight phases. Supernatants were recovered by centrifugation, filtered, and stored at -20°C. The primary HSMCs culture was exposed for 24 hours to purified LPS of a pathogen strain of Escherichia coli (O111:B4) (1 μg/mL) with and without supernatants. Postbiotic effects were evaluated on the basis of HSMCs morphofunctional alterations and interleukin-6 (IL-6) production. Data are expressed as mean±SE (P<0.05 significant). RESULTS LPS induced persistent, significant, 20.5%±0.7% cell shortening and 34.5%±2.2% decrease in acetylcholine-induced contraction of human HSMCs. These morphofunctional alterations were paralleled to a 365.65%±203.13% increase in IL-6 production. All these effects were dose-dependently reduced by LGG supernatants. Supernatants of the middle exponential phase already partially restored LPS-induced cell shortening by 57.34%±12.7% and IL-6 increase by 145.8%±4.3% but had no effect on LPS-induced inhibition of contraction. Maximal protective effects were obtained with supernatants of the late stationary phase with LPS-induced cell shortening restored by 84.1%±4.7%, inhibition of contraction by 85.5%±6.4%, and IL-6 basal production by 92.7%±1.2%. CONCLUSIONS LGG-derived products are able to protect human SMCs from LPS-induced myogenic damage. Novel insights have been provided for the possibility that LGG-derived products could reduce the risk of progression to postinfective motor disorders.
Collapse
|
13
|
Regulator of G protein signaling 4 is a novel target of GATA-6 transcription factor. Biochem Biophys Res Commun 2016; 483:923-929. [PMID: 27746176 DOI: 10.1016/j.bbrc.2016.10.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 10/11/2016] [Indexed: 12/12/2022]
Abstract
GATA transcription factors regulate an array of genes important in cell proliferation and differentiation. Here we report the identification of regulator of G protein signaling 4 (RGS4) as a novel target for GATA-6 transcription factor. Although three sites (a, b, c) within the proximal region of rabbit RGS4 promoter for GATA transcription factors were predicted by bioinformatics analysis, only GATA-a site (16 bp from the core TATA box) is essential for RGS4 transcriptional regulation. RT-PCR analysis demonstrated that only GATA-6 was highly expressed in rabbit colonic smooth muscle cells but GATA-4/6 were expressed in cardiac myocytes and GATA-1/2/3 expressed in blood cells. Adenovirus-mediated expression of GATA-6 but not GATA-1 significantly increased the constitutive and IL-1β-induced mRNA expression of the endogenous RGS4 in colonic smooth muscle cells. IL-1β stimulation induced GATA-6 nuclear translocation and increased GATA-6 binding to RGS4 promoter. These data suggest that GATA factor could affect G protein signaling through regulating RGS4 expression, and GATA signaling may develop as a future therapeutic target for RGS4-related diseases.
Collapse
|
14
|
Zhang Y, Li F, Wang H, Yin C, Huang J, Mahavadi S, Murthy KS, Hu W. Immune/Inflammatory Response and Hypocontractility of Rabbit Colonic Smooth Muscle After TNBS-Induced Colitis. Dig Dis Sci 2016; 61:1925-40. [PMID: 26879904 PMCID: PMC4920730 DOI: 10.1007/s10620-016-4078-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 02/03/2016] [Indexed: 12/13/2022]
Abstract
BACKGROUND The contractility of colonic smooth muscle is dysregulated due to immune/inflammatory responses in inflammatory bowel diseases. Inflammation in vitro induces up-regulation of regulator of G-protein signaling 4 (RGS4) expression in colonic smooth muscle cells. AIMS To characterize the immune/inflammatory responses and RGS4 expression pattern in colonic smooth muscle after induction of colitis. METHODS Colitis was induced in rabbits by intrarectal instillation of 2,4,6-trinitrobenzene sulfonic acid (TNBS). Innate/adaptive immune response RT-qPCR array was performed using colonic circular muscle strips. At 1-9 weeks after colonic intramuscular microinjection of lentivirus, the distal and proximal colons were collected, and muscle strips and dispersed muscle cells were prepared from circular muscle layer. Expression levels of RGS4 and NFκB signaling components were determined by Western blot analysis. The biological consequences of RGS4 knockdown were assessed by measurement of muscle contraction and phospholipase C (PLC)-β activity in response to acetylcholine (ACh). RESULTS Contraction in response to ACh was significantly inhibited in the inflamed colonic circular smooth muscle cells. RGS4, IL-1, IL-6, IL-8, CCL3, CD1D, and ITGB2 were significantly up-regulated, while IL-18, CXCR4, CD86, and C3 were significantly down-regulated in the inflamed muscle strips. RGS4 protein expression in the inflamed smooth muscles was dramatically increased. RGS4 stable knockdown in vivo augmented ACh-stimulated PLC-β activity and contraction in colonic smooth muscle cells. CONCLUSION Inflamed smooth muscle exhibits up-regulation of IL-1-related signaling components, Th1 cytokines and RGS4, and inhibition of contraction. Stable knockdown of endogenous RGS4 in colonic smooth muscle increases PLC-β activity and contractile responses.
Collapse
Affiliation(s)
- Yonggang Zhang
- Department of Neuroscience, Temple University School of Medicine, 3500 N Broad Street, Philadelphia, PA 19140, USA
| | - Fang Li
- Department of Neuroscience, Temple University School of Medicine, 3500 N Broad Street, Philadelphia, PA 19140, USA
| | - Hong Wang
- Department of Neuroscience, Temple University School of Medicine, 3500 N Broad Street, Philadelphia, PA 19140, USA
| | - Chaoran Yin
- Department of Neuroscience, Temple University School of Medicine, 3500 N Broad Street, Philadelphia, PA 19140, USA
| | - JieAn Huang
- Department of Gastroenterology, First Affiliated Hospital, Guangxi Medical University, No. 6 Shuangyong Rd, Nanning 530021, Guangxi, China
| | - Sunila Mahavadi
- Department of Physiology and Biophysics, Medical College of Virginia Campus, Virginia Commonwealth University, 1101 East Marshall Street, Richmond, VA 23298, USA
| | - Karnam S. Murthy
- Department of Physiology and Biophysics, Medical College of Virginia Campus, Virginia Commonwealth University, 1101 East Marshall Street, Richmond, VA 23298, USA
| | - Wenhui Hu
- Department of Neuroscience, Temple University School of Medicine, 3500 N Broad Street, Philadelphia, PA 19140, USA
| |
Collapse
|
15
|
Jiang W, Luo T, Li S, Zhou Y, Shen XY, He F, Xu J, Wang HQ. Quercetin Protects against Okadaic Acid-Induced Injury via MAPK and PI3K/Akt/GSK3β Signaling Pathways in HT22 Hippocampal Neurons. PLoS One 2016; 11:e0152371. [PMID: 27050422 PMCID: PMC4822954 DOI: 10.1371/journal.pone.0152371] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2015] [Accepted: 03/14/2016] [Indexed: 11/28/2022] Open
Abstract
Increasing evidence shows that oxidative stress and the hyperphosphorylation of tau protein play essential roles in the progression of Alzheimer’s disease (AD). Quercetin is a major flavonoid that has anti-oxidant, anti-cancer and anti-inflammatory properties. We investigated the neuroprotective effects of quercetin to HT22 cells (a cell line from mouse hippocampal neurons). We found that Okadaic acid (OA) induced the hyperphosphorylation of tau protein at Ser199, Ser396, Thr205, and Thr231 and produced oxidative stress to the HT22 cells. The oxidative stress suppressed the cell viability and decreased the levels of lactate dehydrogenase (LDH), superoxide dismutase (SOD), mitochondria membrane potential (MMP) and Glutathione peroxidase (GSH-Px). It up-regulated malondialdehyde (MDA) production and intracellular reactive oxygen species (ROS). In addition, phosphoinositide 3 kinase/protein kinase B/Glycogen synthase kinase3β (PI3K/Akt/GSK3β) and mitogen activated protein kinase (MAPK) were also involved in this process. We found that pre-treatment with quercetin can inhibited OA-induced the hyperphosphorylation of tau protein and oxidative stress. Moreover, pre-treatment with quercetin not only inhibited OA-induced apoptosis via the reduction of Bax, and up-regulation of cleaved caspase 3, but also via the inhibition of PI3K/Akt/GSK3β, MAPKs and activation of NF-κB p65. Our findings suggest the therapeutic potential of quercetin to treat AD.
Collapse
Affiliation(s)
- Wei Jiang
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, 510080, China
- Department of Anatomy and Histoembryology, Zhaoqing Medical College, Zhaoqing, Guangdong, 526020, China
| | - Tao Luo
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, 510080, China
| | - Sheng Li
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, 510080, China
| | - Yue Zhou
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, 510080, China
| | - Xiu-Yin Shen
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, 510080, China
| | - Feng He
- School of Pharmaceutical Science, Sun Yat-sen University, Guangzhou, Guangdong, 510006, China
- * E-mail: (FH); (HQW)
| | - Jie Xu
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, 510080, China
| | - Hua-Qiao Wang
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, 510080, China
- * E-mail: (FH); (HQW)
| |
Collapse
|
16
|
Kumar DP, Asgharpour A, Mirshahi F, Park SH, Liu S, Imai Y, Nadler JL, Grider JR, Murthy KS, Sanyal AJ. Activation of Transmembrane Bile Acid Receptor TGR5 Modulates Pancreatic Islet α Cells to Promote Glucose Homeostasis. J Biol Chem 2016; 291:6626-40. [PMID: 26757816 DOI: 10.1074/jbc.m115.699504] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Indexed: 12/19/2022] Open
Abstract
The physiological role of the TGR5 receptor in the pancreas is not fully understood. We previously showed that activation of TGR5 in pancreatic β cells by bile acids induces insulin secretion. Glucagon released from pancreatic α cells and glucagon-like peptide 1 (GLP-1) released from intestinal L cells regulate insulin secretion. Both glucagon and GLP-1 are derived from alternate splicing of a common precursor, proglucagon by PC2 and PC1, respectively. We investigated whether TGR5 activation in pancreatic α cells enhances hyperglycemia-induced PC1 expression thereby releasing GLP-1, which in turn increases β cell mass and function in a paracrine manner. TGR5 activation augmented a hyperglycemia-induced switch from glucagon to GLP-1 synthesis in human and mouse islet α cells by GS/cAMP/PKA/cAMP-response element-binding protein-dependent activation of PC1. Furthermore, TGR5-induced GLP-1 release from α cells was via an Epac-mediated PKA-independent mechanism. Administration of the TGR5 agonist, INT-777, to db/db mice attenuated the increase in body weight and improved glucose tolerance and insulin sensitivity. INT-777 augmented PC1 expression in α cells and stimulated GLP-1 release from islets of db/db mice compared with control. INT-777 also increased pancreatic β cell proliferation and insulin synthesis. The effect of TGR5-mediated GLP-1 from α cells on insulin release from islets could be blocked by GLP-1 receptor antagonist. These results suggest that TGR5 activation mediates cross-talk between α and β cells by switching from glucagon to GLP-1 to restore β cell mass and function under hyperglycemic conditions. Thus, INT-777-mediated TGR5 activation could be leveraged as a novel way to treat type 2 diabetes mellitus.
Collapse
Affiliation(s)
- Divya P Kumar
- Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, Virginia 23298 and
| | | | | | - So Hyun Park
- the Department of Internal Medicine, Strelitz Diabetes Center, Eastern Virginia Medical School, Norfolk, Virginia 23507
| | - Sichen Liu
- the Department of Internal Medicine, Strelitz Diabetes Center, Eastern Virginia Medical School, Norfolk, Virginia 23507
| | - Yumi Imai
- the Department of Internal Medicine, Strelitz Diabetes Center, Eastern Virginia Medical School, Norfolk, Virginia 23507
| | - Jerry L Nadler
- the Department of Internal Medicine, Strelitz Diabetes Center, Eastern Virginia Medical School, Norfolk, Virginia 23507
| | - John R Grider
- Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, Virginia 23298 and
| | - Karnam S Murthy
- Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, Virginia 23298 and
| | | |
Collapse
|
17
|
Rajagopal S, Nalli AD, Kumar DP, Bhattacharya S, Hu W, Mahavadi S, Grider JR, Murthy KS. Cytokine-induced S-nitrosylation of soluble guanylyl cyclase and expression of phosphodiesterase 1A contribute to dysfunction of longitudinal smooth muscle relaxation. J Pharmacol Exp Ther 2014; 352:509-18. [PMID: 25550199 DOI: 10.1124/jpet.114.221929] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The effect of proinflammatory cytokines on the expression and activity of soluble guanylyl cyclase (sGC) and cGMP-phosphodiesterases (PDEs) was determined in intestinal longitudinal smooth muscle. In control muscle cells, cGMP levels are regulated via activation of sGC and PDE5; the activity of the latter is regulated via feedback phosphorylation by cGMP-dependent protein kinase. In muscle cells isolated from muscle strips cultured with interleukin-1β (IL-1β) or tumor necrosis factor α (TNF-α) or obtained from the colon of TNBS (2,4,6-trinitrobenzene sulfonic acid)-treated mice, expression of inducible nitric oxide synthase (iNOS) was induced and sGC was S-nitrosylated, resulting in attenuation of nitric oxide (NO)-induced sGC activity and cGMP formation. The effect of cytokines on sGC S-nitrosylation and activity was blocked by the iNOS inhibitor 1400W [N-([3-(aminomethyl)phenyl]methyl)ethanimidamide dihydrochloride]. The effect of cytokines on cGMP levels measured in the absence of IBMX (3-isobutyl-1-methylxanthine), however, was partly reversed by 1400W or PDE1 inhibitor vinpocetine and completely reversed by a combination of 1400W and vinpocetine. Expression of PDE1A was induced and was accompanied by an increase in PDE1A activity in muscle cells isolated from muscle strips cultured with IL-1β or TNF-α or obtained from the colon of TNBS-treated mice; the effect of cytokines on PDE1 expression and activity was blocked by MG132 (benzyl N-[(2S)-4-methyl-1-[[(2S)-4-methyl-1-[[(2S)-4-methyl-1-oxopentan-2-yl]amino]-1-oxopentan-2-yl]amino]-1-oxopentan-2-yl]carbamate), an inhibitor of nuclear factor κB activity. NO-induced muscle relaxation was inhibited in longitudinal muscle cells isolated from muscle strips cultured with IL-1β or TNF-α or obtained from the colon of TNBS-treated mice, and this inhibition was completely reversed by the combination of both 1400W and vinpocetine. Inhibition of smooth muscle relaxation during inflammation reflects the combined effects of decreased sGC activity via S-nitrosylation and increased cGMP hydrolysis via PDE1 expression.
Collapse
Affiliation(s)
- Senthilkumar Rajagopal
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Ancy D Nalli
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Divya P Kumar
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Sayak Bhattacharya
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Wenhui Hu
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Sunila Mahavadi
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - John R Grider
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Karnam S Murthy
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| |
Collapse
|
18
|
Abstract
Probiotics are alive nonpathogenic microorganisms present in the gut microbiota that confer benefits to the host for his health. They act through molecular and cellular mechanisms that contrast pathogen bacteria adhesion, enhance innate immunity, decrease pathogen-induced inflammation, and promote intestinal epithelial cell survival, barrier function, and protective responses. Some of these beneficial effects result to be determined by secreted probiotic-derived factors that recently have been identified as "postbiotic" mediators. They have been reported for several probiotic strains but most available literature concerns Lactobacilli. In this review, we focus on the reported actions of several secretory products of different Lactobacillus species highlighting the available mechanistic data. The identification of soluble factors mediating the beneficial effects of probiotics may present an opportunity not only to understand their fine mechanisms of action, but also to develop effective pharmacological strategies that could integrate the action of treatments with live bacteria.
Collapse
|
19
|
Mahavadi S, Nalli AD, Kumar DP, Hu W, Kuemmerle JF, Grider JR, Murthy KS. Cytokine-induced iNOS and ERK1/2 inhibit adenylyl cyclase type 5/6 activity and stimulate phosphodiesterase 4D5 activity in intestinal longitudinal smooth muscle. Am J Physiol Cell Physiol 2014; 307:C402-11. [PMID: 24944202 PMCID: PMC4137135 DOI: 10.1152/ajpcell.00123.2014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 06/17/2014] [Indexed: 01/26/2023]
Abstract
This study identified a distinctive pattern of expression and activity of adenylyl cyclase (AC) and phosphodiesterase (PDE) isoforms in mouse colonic longitudinal smooth muscle cells and determined the changes in their expression and/or activity in response to proinflammatory cytokines (IL-1β and TNF-α) in vitro and 2,4,6 trinitrobenzene sulphonic acid (TNBS)-induced colonic inflammation in vivo. AC5/6 and PDE4D5, expressed in circular muscle cells, were also expressed in longitudinal smooth muscle. cAMP formation was tightly regulated via feedback phosphorylation of AC5/6 and PDE4D5 by PKA. Inhibition of PKA activity by myristoylated PKI blocked phosphorylation of AC5/6 and PDE4D5 and enhanced cAMP formation. TNBS treatment in vivo and IL-1β and TNF-α in vitro induced inducible nitric oxide synthase (iNOS) expression, stimulated ERK1/2 activity, caused iNOS-mediated S-nitrosylation and inhibition of AC5/6, and induced phosphorylation of PDE4D5 and stimulated its activity. The resultant decrease in AC5/6 activity and increase in PDE4D5 activity decreased cAMP formation and smooth muscle relaxation. S-nitrosylation and inhibition of AC5/6 activity were reversed by the iNOS inhibitor 1400W, whereas phosphorylation and activation of PDE4D5 were reversed by the phosphatidylinositol 3-kinase inhibitor LY294002 and the ERK1/2 inhibitor PD98059. The effects of IL-1β or TNF-α on forskolin-stimulated cAMP formation and smooth muscle relaxation reflected inhibition of AC5/6 activity and activation of PDE4D5 and were partly reversed by 1400W or PD98059 and completely reversed by a combination of the two inhibitors. The changes in the cAMP/PKA signaling and smooth muscle relaxation contribute to colonic dysmotility during inflammation.
Collapse
Affiliation(s)
- Sunila Mahavadi
- Department of Physiology and Biophysics, Virginia Commonwealth University Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia; and
| | - Ancy D Nalli
- Department of Physiology and Biophysics, Virginia Commonwealth University Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia; and
| | - Divya P Kumar
- Department of Physiology and Biophysics, Virginia Commonwealth University Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia; and
| | - Wenhui Hu
- Department of Neuroscience, Temple University School of Medicine, Philadelphia, Pennsylvania
| | - John F Kuemmerle
- Department of Physiology and Biophysics, Virginia Commonwealth University Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia; and
| | - John R Grider
- Department of Physiology and Biophysics, Virginia Commonwealth University Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia; and
| | - Karnam S Murthy
- Department of Physiology and Biophysics, Virginia Commonwealth University Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia; and
| |
Collapse
|
20
|
Akiho H, Tokita Y, Nakamura K, Satoh K, Nishiyama M, Tsuchiya N, Tsuchiya K, Ohbuchi K, Iwakura Y, Ihara E, Takayanagi R, Yamamoto M. Involvement of interleukin-17A-induced hypercontractility of intestinal smooth muscle cells in persistent gut motor dysfunction. PLoS One 2014; 9:e92960. [PMID: 24796324 PMCID: PMC4010403 DOI: 10.1371/journal.pone.0092960] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 02/27/2014] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND AND AIM The etiology of post-inflammatory gastrointestinal (GI) motility dysfunction, after resolution of acute symptoms of inflammatory bowel diseases (IBD) and intestinal infection, is largely unknown, however, a possible involvement of T cells is suggested. METHODS Using the mouse model of T cell activation-induced enteritis, we investigated whether enhancement of smooth muscle cell (SMC) contraction by interleukin (IL)-17A is involved in postinflammatory GI hypermotility. RESULTS Activation of CD3 induces temporal enteritis with GI hypomotility in the midst of, and hypermotility after resolution of, intestinal inflammation. Prolonged upregulation of IL-17A was prominent and IL-17A injection directly enhanced GI transit and contractility of intestinal strips. Postinflammatory hypermotility was not observed in IL-17A-deficient mice. Incubation of a muscle strip and SMCs with IL-17A in vitro resulted in enhanced contractility with increased phosphorylation of Ser19 in myosin light chain 2 (p-MLC), a surrogate marker as well as a critical mechanistic factor of SMC contractility. Using primary cultured murine and human intestinal SMCs, IκBζ- and p38 mitogen-activated protein kinase (p38MAPK)-mediated downregulation of the regulator of G protein signaling 4 (RGS4), which suppresses muscarinic signaling of contraction by promoting inactivation/desensitization of Gαq/11 protein, has been suggested to be involved in IL-17A-induced hypercontractility. The opposite effect of L-1β was mediated by IκBζ and c-jun N-terminal kinase (JNK) activation. CONCLUSIONS We propose and discuss the possible involvement of IL-17A and its downstream signaling cascade in SMCs in diarrheal hypermotility in various GI disorders.
Collapse
Affiliation(s)
- Hirotada Akiho
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
- Department of Gastroenterology, Kitakyushu Municipal Medical Center, Fukuoka, Japan
- * E-mail:
| | - Yohei Tokita
- Tsumura Research Laboratories, Tsumura & Co., Ibaraki, Japan
| | - Kazuhiko Nakamura
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Kazuko Satoh
- Tsumura Research Laboratories, Tsumura & Co., Ibaraki, Japan
| | | | - Naoko Tsuchiya
- Tsumura Research Laboratories, Tsumura & Co., Ibaraki, Japan
| | | | - Katsuya Ohbuchi
- Tsumura Research Laboratories, Tsumura & Co., Ibaraki, Japan
| | - Yoichiro Iwakura
- Division of Laboratory Animal, Research Institute for Biomedical Science, Tokyo University of Science, Chiba, Japan
- Core Research for Evolutional Science and Technology (CREST), JST, Saitama, Japan
| | - Eikichi Ihara
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Ryoichi Takayanagi
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | | |
Collapse
|
21
|
Nalli AD, Kumar DP, Mahavadi S, Al-Shboul O, Alkahtani R, Kuemmerle JF, Grider JR, Murthy KS. Hypercontractility of intestinal longitudinal smooth muscle induced by cytokines is mediated by the nuclear factor-κB/AMP-activated kinase/myosin light chain kinase pathway. J Pharmacol Exp Ther 2014; 350:89-98. [PMID: 24769544 DOI: 10.1124/jpet.113.212522] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Recent studies have identified AMP-activated kinase (AMPK) as a target of Ca(2+)/calmodulin-dependent kinase kinase (CaMKKβ) and a negative regulator of myosin light-chain (MLC) kinase (MLCK). The present study examined whether a change in expression or activity of AMPK is responsible for hypercontractility of intestinal longitudinal muscle during inflammation or in response to proinflammatory cytokines. In mouse colonic longitudinal muscle cells, acetylcholine (ACh) stimulated AMPK and MLCK phosphorylation and activity and induced MLC20 phosphorylation and muscle contraction. Blockade of CaMKKβ with STO609 (7-oxo-7H-benzimidazo[2,1-a]benz[de]isoquinoline-3-carboxylic acid acetate) inhibited AMPK and MLCK phosphorylation and augmented MLCK activity, MLC20 phosphorylation, and smooth muscle cell contraction. In muscle cells isolated from the colon of TNBS (2,4,6-trinitrobenzenesulfonic acid)-treated mice or from strips treated with interleukin-1β or tumor necrosis factor-α, nuclear factor κB was activated as indicated by an increase in p65 phosphorylation and IκBα degradation, and AMPK was phosphorylated at a cAMP-dependent protein kinase (PKA)-specific site (Ser(485)) that is distinct from the stimulatory CaMKKβ site (Thr(172)), resulting in attenuation of ACh-stimulated AMPK activity and augmentation of MLCK activity and muscle cell contraction. Inhibition of nuclear factor-κB activity with MG-132 (carbobenzoxy-L-leucyl-L-leucyl-L-leucinal Z-LLL-CHO) or PKA activity with myristoylated PKA inhibitor 14-22 amide blocked phosphorylation of AMPK at Ser(485) and restored MLCK activity and muscle cell contraction to control levels. The results imply that PKA released from IκBα complex phosphorylated AMPK at a PKA-specific site and inhibited its activity, thereby relieving the inhibitory effect of AMPK on MLCK and increasing MLCK activity and muscle cell contraction. We conclude that hypercontractility of intestinal longitudinal muscle induced by inflammation or proinflammatory cytokines is mediated by nuclear factor κB/PKA-dependent inhibition of AMPK and activation of MLCK.
Collapse
Affiliation(s)
- Ancy D Nalli
- Department of Physiology and Biophysics, Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Divya P Kumar
- Department of Physiology and Biophysics, Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Sunila Mahavadi
- Department of Physiology and Biophysics, Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Othman Al-Shboul
- Department of Physiology and Biophysics, Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Reem Alkahtani
- Department of Physiology and Biophysics, Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - John F Kuemmerle
- Department of Physiology and Biophysics, Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - John R Grider
- Department of Physiology and Biophysics, Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Karnam S Murthy
- Department of Physiology and Biophysics, Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| |
Collapse
|
22
|
Al-Shboul O, Nalli AD, Kumar DP, Zhou R, Mahavadi S, Kuemmerle JF, Grider JR, Murthy KS. Jun kinase-induced overexpression of leukemia-associated Rho GEF (LARG) mediates sustained hypercontraction of longitudinal smooth muscle in inflammation. Am J Physiol Cell Physiol 2014; 306:C1129-41. [PMID: 24740538 DOI: 10.1152/ajpcell.00021.2014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The signaling pathways mediating sustained contraction of mouse colonic longitudinal smooth muscle and the mechanisms involved in hypercontractility of this muscle layer in response to cytokines and TNBS-induced colitis have not been fully explored. In control longitudinal smooth muscle cells, ACh acting via m3 receptors activated sequentially Gα12, RhoGEF (LARG), and the RhoA/Rho kinase pathway. There was abundant expression of MYPT1, minimal expression of CPI-17, and a notable absence of a PKC/CPI-17 pathway. LARG expression was increased in longitudinal muscle cells isolated from muscle strips cultured for 24 h with IL-1β or TNF-α or obtained from the colon of TNBS-treated mice. The increase in LARG expression was accompanied by a significant increase in ACh-stimulated Rho kinase and ZIP kinase activities, and sustained muscle contraction. The increase in LARG expression, Rho kinase and ZIP kinase activities, and sustained muscle contraction was abolished in cells pretreated with the Jun kinase inhibitor, SP600125. Expression of the MLCP activator, telokin, and MLCP activity were also decreased in longitudinal muscle cells from TNBS-treated mice or from strips treated with IL-1β or TNF-α. In contrast, previous studies had shown that sustained contraction in circular smooth muscle is mediated by sequential activation of Gα13, p115RhoGEF, and dual RhoA-dependent pathways involving phosphorylation of MYPT1 and CPI-17. In colonic circular smooth muscle cells isolated from TNBS-treated mice or from strips treated with IL-1β or TNF-α, CPI-17 expression and sustained muscle contraction were decreased. The disparate changes in the two muscle layers contribute to intestinal dysmotility during inflammation.
Collapse
Affiliation(s)
- Othman Al-Shboul
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Ancy D Nalli
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Divya P Kumar
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Ruizhe Zhou
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Sunila Mahavadi
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - John F Kuemmerle
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - John R Grider
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| | - Karnam S Murthy
- Department of Physiology and Biophysics, VCU Program in Enteric Neuromuscular Sciences, Virginia Commonwealth University, Richmond, Virginia
| |
Collapse
|
23
|
Ammoscato F, Scirocco A, Altomare A, Matarrese P, Petitta C, Ascione B, Caronna R, Guarino M, Marignani M, Cicala M, Chirletti P, Malorni W, Severi C. Lactobacillus rhamnosus protects human colonic muscle from pathogen lipopolysaccharide-induced damage. Neurogastroenterol Motil 2013; 25:984-e777. [PMID: 24118564 DOI: 10.1111/nmo.12232] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 08/15/2013] [Indexed: 12/11/2022]
Abstract
BACKGROUND Lactobacillus species might positively affect gastrointestinal motility. These Gram-positive bacteria bind Toll-like receptor 2 (TLR2) that elicits anti-inflammatory activity and exerts protective effects on damage induced by lipopolysaccharide (LPS). Whether such effect occurs in gastrointestinal smooth muscle has not been established yet. Aim of this study was to characterize the effects of Lactobacillus rhamnosus GG (LGG) and of supernatants harvested from LGG cultures on human colonic smooth muscle and to explore their protective activity against LPS-induced myogenic morpho-functional alterations. METHODS The effects of LGG (ATCC 53103 strain) and of supernatants have been tested on both human colonic smooth muscle strips and isolated cells in the absence or presence of LPS obtained from a pathogenic strain of Escherichia coli. Their effects on myogenic morpho-functional properties, on LPS-induced NFκB activation, and on cytokine production have been evaluated. Toll-like receptor 2 expression has been analyzed by qPCR and flow cytometry. KEY RESULTS Lactobacillus rhamnosus GG exerted negligible transient effects per se whereas it was capable of activating an intrinsic myogenic response counteracting LPS-induced alterations. In particular, both LGG and supernatants significantly reduced the LPS-induced morpho-functional alterations of muscle cells, i.e. cell shortening and inhibition of contractile response. They also hindered LPS-induced pro-inflammatory effects by decreasing pro-inflammatory transcription factor NFκB activation and pro-inflammatory cytokine IL-6 secretion, and restored the secretion levels of anti-inflammatory cytokine IL10. CONCLUSIONS & INFERENCES Taken together these data demonstrate that LGG protects human colonic smooth muscle from LPS-induced myogenic damage and might be beneficial on intestinal motor disorders due to bacterial infection.
Collapse
Affiliation(s)
- F Ammoscato
- Department of Internal Medicine and Medical Specialties, University Sapienza, Rome, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Abstract
AIM To test the activities of culture-extracted or commercially available toll-like receptors (TLRs) ligands to establish their direct impact on target gastrointestinal motor cells. METHODS Short-term and long-term effects of Shigella flexneri M90T and Escherichia coli K-2 strains-extracted lipopolysaccharides (LPS), commercially highly purified LPS (E. coli O111:B4 and EH100), and Pam2CSK4 and Pam3CSK4, which bind TLR2/6 and TLR1/2 heterodimers, respectively, have been assessed on pure primary cultures of colonic human smooth muscle cells (HSMC). RESULTS Pathogenic Shigella-LPS and nonpathogenic E. coli K-2-LPS induced a time-dependent decrease of resting cell length and acetylcholine-induced contraction, with both alterations occurring rapidly and being more pronounced in response to the former. However, their effects differed, prolonging HSMC exposure with Shigella-LPS effects maintained throughout the 4 hours of observation compared with E. coli K-2-LPS, which disappeared after 60 minutes of incubation. Similar differences in magnitude and time dependency of myogenic effects were observed between pure TLR4 and TLR2/1 or TLR2/6 ligands. The specific activation of TLR4 with LPS from pathogen or nonpathogen E. coli, O111:B4 and EH100, respectively, induced smooth muscle alterations that progressively increased, prolonging incubation, whereas TLR2 ligands induced short-term alterations, of a lesser magnitude, which decreased over time. The real-time polymerase chain reaction analysis showed that HSMC express mRNA for TLR1, 2, 4, and 6, substantiating a direct effect of TLR ligands on human colonic smooth muscle. CONCLUSIONS This study highlights that bacterial products can directly affect gastrointestinal motility and that TLRs subtypes may differ in their cellular activity.
Collapse
|
25
|
Kumar DP, Rajagopal S, Mahavadi S, Mirshahi F, Grider JR, Murthy KS, Sanyal AJ. Activation of transmembrane bile acid receptor TGR5 stimulates insulin secretion in pancreatic β cells. Biochem Biophys Res Commun 2012; 427:600-5. [PMID: 23022524 DOI: 10.1016/j.bbrc.2012.09.104] [Citation(s) in RCA: 144] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Accepted: 09/19/2012] [Indexed: 10/27/2022]
Abstract
Bile acids act as signaling molecules and stimulate the G protein coupled receptor, TGR5, in addition to nuclear farnesoid X receptor to regulate lipid, glucose and energy metabolism. Bile acid induced activation of TGR5 in the enteroendocrine cells promotes glucagon like peptide-1 (GLP-1) release, which has insulinotropic effect in the pancreatic β cells. In the present study, we have identified the expression of TGR5 in pancreatic β cell line MIN6 and also in mouse and human pancreatic islets. TGR5 selective ligands, oleanolic acid (OA) and INT-777 selectively activated Gα(s) and caused an increase in intracellular cAMP and Ca(2+). OA and INT-777 also increased phosphoinositide (PI) hydrolysis and the increase was blocked by NF449 (a selective Gα(s) inhibitor) or U73122 (PI hydrolysis inhibitor). OA, INT-777 and lithocholic acid increased insulin release in MIN6 and human islets and the increase was inhibited by treatment with NF449, U73122 or BAPTA-AM (chelator of calcium), but not with myristoylated PKI (PKA inhibitor), suggesting that the release is dependent on G(s)/cAMP/Ca(2+) pathway. 8-pCPT-2'-O-Me-cAMP, a cAMP analog, which activates Epac, but not PKA also stimulated PI hydrolysis. In conclusion, our study demonstrates that the TGR5 expressed in the pancreatic β cells regulates insulin secretion and highlights the importance of ongoing therapeutic strategies targeting TGR5 in the control of glucose homeostasis.
Collapse
Affiliation(s)
- Divya P Kumar
- Department of Physiology and Biophysics, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | | | | | | | | | | | | |
Collapse
|
26
|
Abstract
An essential mode of acquired resistance to radiotherapy (RT) appears to be promotion of tumor cell motility and invasiveness in various cancer types, including glioblastoma, a process resembling 'evasive resistance'. Hence, a logical advancement of RT would be to identify suitable complementary treatment strategies, ideally targeting cell motility. Here we report that the combination of focal RT and mammalian target of rapamycin (mTOR) inhibition using clinically relevant concentrations of temsirolimus (CCI-779) prolongs survival in a syngeneic mouse glioma model through additive cytostatic effects. In vitro, the mTOR inhibitor CCI-779 exerted marked anti-invasive effects, irrespective of the phosphatase and tensin homolog deleted on chromosome 10 status and counteracted the proinvasive effect of sublethal irradiation. Mechanistically, we identified regulator of G-protein signaling 4 (RGS4) as a novel target of mTOR inhibition and a key driver of glioblastoma invasiveness, sensitive to the anti-invasive properties of CCI-779. Notably, suppression of RGS4-dependent glioma cell invasion was signaled through both mTOR complexes, mTORC1 and mTORC2, in a concentration-dependent manner, indicating that high doses of CCI-779 may overcome tumor-cell resistance associated with the sole inhibition of mTORC1. We conclude that combined RT and mTOR inhibition is a promising therapeutic option that warrants further clinical investigation in upfront glioblastoma therapy.
Collapse
|
27
|
Kach J, Sethakorn N, Dulin NO. A finer tuning of G-protein signaling through regulated control of RGS proteins. Am J Physiol Heart Circ Physiol 2012; 303:H19-35. [PMID: 22542620 DOI: 10.1152/ajpheart.00764.2011] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Regulators of G-protein signaling (RGS) proteins are GTPase-activating proteins (GAP) for various Gα subunits of heterotrimeric G proteins. Through this mechanism, RGS proteins regulate the magnitude and duration of G-protein-coupled receptor signaling and are often referred to as fine tuners of G-protein signaling. Increasing evidence suggests that RGS proteins themselves are regulated through multiple mechanisms, which may provide an even finer tuning of G-protein signaling and crosstalk between G-protein-coupled receptors and other signaling pathways. This review summarizes the current data on the control of RGS function through regulated expression, intracellular localization, and covalent modification of RGS proteins, as related to cell function and the pathogenesis of diseases.
Collapse
Affiliation(s)
- Jacob Kach
- Department of Medicine, University of Chicago, Illinois, 60637, USA
| | | | | |
Collapse
|
28
|
MEKK1-MKK4-JNK-AP1 pathway negatively regulates Rgs4 expression in colonic smooth muscle cells. PLoS One 2012; 7:e35646. [PMID: 22545125 PMCID: PMC3335800 DOI: 10.1371/journal.pone.0035646] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 03/19/2012] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Regulator of G-protein Signaling 4 (RGS4) plays an important role in regulating smooth muscle contraction, cardiac development, neural plasticity and psychiatric disorder. However, the underlying regulatory mechanisms remain elusive. Our recent studies have shown that upregulation of Rgs4 by interleukin (IL)-1β is mediated by the activation of NFκB signaling and modulated by extracellular signal-regulated kinases, p38 mitogen-activated protein kinase, and phosphoinositide-3 kinase. Here we investigate the effect of the c-Jun N-terminal kinase (JNK) pathway on Rgs4 expression in rabbit colonic smooth muscle cells. METHODOLOGY/PRINCIPAL FINDINGS Cultured cells at first passage were treated with or without IL-1β (10 ng/ml) in the presence or absence of the selective JNK inhibitor (SP600125) or JNK small hairpin RNA (shRNA). The expression levels of Rgs4 mRNA and protein were determined by real-time RT-PCR and Western blot respectively. SP600125 or JNK shRNA increased Rgs4 expression in the absence or presence of IL-1β stimulation. Overexpression of MEKK1, the key upstream kinase of JNK, inhibited Rgs4 expression, which was reversed by co-expression of JNK shRNA or dominant-negative mutants for MKK4 or JNK. Both constitutive and inducible upregulation of Rgs4 expression by SP600125 was significantly inhibited by pretreatment with the transcription inhibitor, actinomycin D. Dual reporter assay showed that pretreatment with SP600125 sensitized the promoter activity of Rgs4 in response to IL-1β. Mutation of the AP1-binding site within Rgs4 promoter increased the promoter activity. Western blot analysis confirmed that IL-1β treatment increased the phosphorylation of JNK, ATF-2 and c-Jun. Gel shift and chromatin immunoprecipitation assays validated that IL-1β increased the in vitro and ex vivo binding activities of AP1 within rabbit Rgs4 promoter. CONCLUSION/SIGNIFICANCE Activation of MEKK1-MKK4-JNK-AP1 signal pathway plays a tonic inhibitory role in regulating Rgs4 transcription in rabbit colonic smooth muscle cells. This negative regulation may aid in maintaining the transient level of RGS4 expression.
Collapse
|
29
|
Ihara E, Chappellaz M, Turner SR, MacDonald JA. The contribution of protein kinase C and CPI-17 signaling pathways to hypercontractility in murine experimental colitis. Neurogastroenterol Motil 2012; 24:e15-26. [PMID: 22093175 DOI: 10.1111/j.1365-2982.2011.01821.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND Colonic smooth muscle contractility is altered in colitis, and several protein kinase pathways can mediate colonic smooth muscle contraction. In the present study, we investigated whether protein kinase C (PKC) pathways also play a role in colonic hypercontractility observed during T(H) 2 colitis in BALB/c mice. METHODS Colitis was induced in BALB/c mice by provision of 5% dextran sodium sulfate (DSS) for 7 days. Changes in smooth muscle contractility were examined using dissected circular smooth muscle preparations from the distal colon. The contribution of conventional and novel PKC isozymes to the hypercontractile response was examined with pharmacological PKC inhibitors. Western blot analyses were used to examine protein expression and phosphorylation changes. KEY RESULTS Colonic smooth muscle was associated with inflammation-induced hypercontractility and altered PKC expression. Carbachol-induced peak (phasic) and sustained (tonic) contractions were increased. Chelerythrine was the most effective PKC inhibitor of both phasic and tonic contractions. There was no general difference in the percent contribution of conventional and novel PKC isozymes toward the DSS-induced hypercontractility, but inhibition of sustained force with GF109203x was higher for inflamed muscle. The CPI-17 phosphorylation was equally suppressed in both normal and DSS conditions by Gö6976 and chelerythrine, but only for the phasic component of contraction. CONCLUSIONS & INFERENCES The outcomes suggest that both conventional and novel PKC isozymes contribute to the phasic and tonic contractile components of BALB/c colonic circular smooth muscle under normal conditions, with novel PKC isozymes having a greater contribution to the tonic contraction. However, no effect of inflammation was observed on the relative contribution of PKC and CPI-17 toward the observed hypercontractility.
Collapse
Affiliation(s)
- E Ihara
- Smooth Muscle and Gastrointestinal Research Groups, Department of Biochemistry & Molecular Biology, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
| | | | | | | |
Collapse
|
30
|
Akiho H, Ihara E, Motomura Y, Nakamura K. Cytokine-induced alterations of gastrointestinal motility in gastrointestinal disorders. World J Gastrointest Pathophysiol 2011; 2:72-81. [PMID: 22013552 PMCID: PMC3196622 DOI: 10.4291/wjgp.v2.i5.72] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Revised: 08/12/2011] [Accepted: 08/19/2011] [Indexed: 02/06/2023] Open
Abstract
Inflammation and immune activation in the gut are usually accompanied by alteration of gastrointestinal (GI) motility. In infection, changes in motor function have been linked to host defense by enhancing the expulsion of the infectious agents. In this review, we describe the evidence for inflammation and immune activation in GI infection, inflammatory bowel disease, ileus, achalasia, eosinophilic esophagitis, microscopic colitis, celiac disease, pseudo-obstruction and functional GI disorders. We also describe the possible mechanisms by which inflammation and immune activation in the gut affect GI motility. GI motility disorder is a broad spectrum disturbance of GI physiology. Although several systems including central nerves, enteric nerves, interstitial cells of Cajal and smooth muscles contribute to a coordinated regulation of GI motility, smooth muscle probably plays the most important role. Thus, we focus on the relationship between activation of cytokines induced by adaptive immune response and alteration of GI smooth muscle contractility. Accumulated evidence has shown that Th1 and Th2 cytokines cause hypocontractility and hypercontractility of inflamed intestinal smooth muscle. Th1 cytokines downregulate CPI-17 and L-type Ca2+ channels and upregulate regulators of G protein signaling 4, which contributes to hypocontractility of inflamed intestinal smooth muscle. Conversely, Th2 cytokines cause hypercontractilty via signal transducer and activator of transcription 6 or mitogen-activated protein kinase signaling pathways. Th1 and Th2 cytokines have opposing effects on intestinal smooth muscle contraction via 5-hydroxytryptamine signaling. Understanding the immunological basis of altered GI motor function could lead to new therapeutic strategies for GI functional and inflammatory disorders.
Collapse
|
31
|
Siedlecki AM, Jin X, Thomas W, Hruska KA, Muslin AJ. RGS4, a GTPase activator, improves renal function in ischemia-reperfusion injury. Kidney Int 2011; 80:263-71. [PMID: 21412219 DOI: 10.1038/ki.2011.63] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Acute kidney dysfunction after ischemia-reperfusion injury (IRI) may be a consequence of persistent intrarenal vasoconstriction. Regulators of G-protein signaling (RGSs) are GTPase activators of heterotrimeric G proteins that can regulate vascular tone. RGS4 is expressed in vascular smooth muscle cells in the kidney; however, its protein levels are low in many tissues due to N-end rule-mediated polyubiquitination and proteasomal degradation. Here, we define the role of RGS4 using a mouse model of IRI comparing wild-type (WT) with RGS4-knockout mice. These knockout mice were highly sensitized to the development of renal dysfunction following injury exhibiting reduced renal blood flow as measured by laser-Doppler flowmetry. The kidneys from knockout mice had increased renal vasoconstriction in response to endothelin-1 infusion ex vivo. The intrinsic renal activity of RGS4 was measured following syngeneic kidney transplantation, a model of cold renal IRI. The kidneys transplanted between knockout and WT mice had significantly reduced reperfusion blood flow and increased renal cell death. WT mice administered MG-132 (a proteasomal inhibitor of the N-end rule pathway) resulted in increased renal RGS4 protein and in an inhibition of renal dysfunction after IRI in WT but not in knockout mice. Thus, RGS4 antagonizes the development of renal dysfunction in response to IRI.
Collapse
Affiliation(s)
- Andrew M Siedlecki
- Nephrology Division, John Milliken Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri, USA.
| | | | | | | | | |
Collapse
|
32
|
Li J, Zhao H, Luo P, Gu Y. Functional cooperation of of IL-1β and RGS4 in the brachial plexus avulsion mediated brain reorganization. J Brachial Plex Peripher Nerve Inj 2010; 5:18. [PMID: 21138588 PMCID: PMC3017042 DOI: 10.1186/1749-7221-5-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Accepted: 12/07/2010] [Indexed: 01/27/2023] Open
Abstract
BACKGROUNDS There is considerable evidence that central nervous system is continuously modulated by activity, behavior and skill acquisition. This study is to examine the reorganization in cortical and subcortical regions in response to brachial plexus avulsion. METHODS Adult C57BL/6 mice were divided into four groups: control, 1, 3 and 6 month of brachial plexus avulsion. IL-1β, IL-6 and RGS4 expression in cortex, brainstem and spinal cord were detected by BiostarM-140 s microarray and real-time PCR. RGS4 subcellular distribution and modulation were further analyzed by primary neuron culture and Western Blot. RESULTS After 1, 3 and 6 months of brachial plexus avulsion, 49 (0 up, 49 down), 29 (17 up, 12 down), 13 (9 up, 4 down) genes in cerebral cortex, 40 (8 up, 32 down), 11 (7 up, 4 down), 137 (63 up, 74 down) in brainstem, 27 (14 up, 13 down), 33 (18 up, 15 down), 60 (29 up, 31 down) in spinal cord were identified. Among the regulated gene, IL-1β and IL-6 were sustainable enhanced in brain stem, while PKACβ and RGS4 were up-regulated throughout cerebral cortex, brainstem and spinal cord in 3 and 6 month of nerve injury. Intriguingly, subcellular distribution of RGS4 in above three regions was dependent on the functional correlation of PKA and IL-1β. CONCLUSION Data herein indicated that brachial plexus avulsion could efficiently initiate and perpetuate the brain reorganization. Network involved IL-1β and RGS4 signaling might implicate in the re-establish and strengthening of the local circuits at the cortical and subcortical levels.
Collapse
Affiliation(s)
- Jifeng Li
- Lab of Hand function reconstruction, Huashan Hospital, Fudan University, Shanghai, China
| | - Hui Zhao
- Lab of Hand function reconstruction, Huashan Hospital, Fudan University, Shanghai, China
| | - Pengbo Luo
- Lab of Hand function reconstruction, Huashan Hospital, Fudan University, Shanghai, China
| | - Yudong Gu
- Lab of Hand function reconstruction, Huashan Hospital, Fudan University, Shanghai, China
| |
Collapse
|
33
|
Li F, Hu DY, Liu S, Mahavadi S, Yen W, Murthy KS, Khalili K, Hu W. RNA-binding protein HuR regulates RGS4 mRNA stability in rabbit colonic smooth muscle cells. Am J Physiol Cell Physiol 2010; 299:C1418-29. [PMID: 20881234 DOI: 10.1152/ajpcell.00093.2010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Regulator of G protein signaling 4 (RGS4) regulates the strength and duration of G protein signaling and plays an important role in smooth muscle contraction, cardiac development, and psychiatric disorders. Little is known about the posttranscriptional regulation of RGS4 expression. We cloned the full-length cDNA of rabbit RGS4, which contains a long 3'-untranslated region (UTR) with several AU-rich elements (AREs). We determined whether RGS4 mRNA stability is mediated by the RNA-binding protein human antigen R (HuR) and contributes to IL-1β-induced upregulation of RGS4 expression. We show that IL-1β treatment in colonic smooth muscle cells doubled the half-life of RGS4 mRNA. Addition of RGS4 3'-UTR to the downstream of Renilla luciferase reporter induced dramatic reduction in the enzyme activity and mRNA expression of luciferase, which was attenuated by the site-directed mutation of the two 3'-most ARE sites. IL-1β increased luciferase mRNA stability in a UTR-dependent manner. Knockdown of HuR significantly aggravated UTR-mediated instability of luciferase and inhibited IL-1β-induced upregulation of RGS4 mRNA. In addition, IL-1β increased cytosolic translocation and RGS4 mRNA binding of HuR. These findings suggest that 3'-most ARE sites within RGS4 3'-UTR are essential for the instability of RGS4 mRNA and IL-1β promotes the stability of RGS4 mRNA through HuR.
Collapse
Affiliation(s)
- Fang Li
- Department of Neuroscience, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Yang J, Huang J, Chatterjee TK, Twait E, Fisher RA. A novel mechanism involving coordinated regulation of nuclear levels and acetylation of NF-YA and Bcl6 activates RGS4 transcription. J Biol Chem 2010; 285:29760-9. [PMID: 20630860 PMCID: PMC2943308 DOI: 10.1074/jbc.m110.121459] [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] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Revised: 07/13/2010] [Indexed: 11/06/2022] Open
Abstract
Neuronally enriched RGS4 plays a critical role attenuating G protein signaling in brain, although the mechanisms regulating RGS4 expression are unknown. Here we describe a novel mechanism for transcriptional activation of RGS4 in neuron-like PC6 cells, where RGS4 is markedly induced during confluence-induced growth arrest. Transcriptional activation of RGS4 in confluent PC6 cells was accompanied by impaired G(i/o)-dependent MAPK activation. In the human RGS4 gene promoter, we identified three phylogenetically conserved cis-elements: an inverted CCAAT box element (ICE), a cAMP response element, and a B-cell lymphoma 6 (Bcl6)-binding site. The ICE and the cAMP response element mediate activation, and the Bcl6 site mediates repression of RGS4 transcription. Activation of RGS4 transcription in confluent PC6 cells is accompanied by increases in NF-YA and C/EBPβ and decreases in Bcl6 levels in the nucleus. Increases in NF-YA and C/EBPβ lead to their increased binding to the RGS4 promoter in vivo, and dominant negative forms of these proteins repressed RGS4 promoter activity. Acetylation of NF-YA and Bcl6 were increased in postconfluent cells. Trichostatin A stimulation of RGS4 promoter activity, accompanied by increased binding of NF-YA and decreased binding of Bcl6 to the promoter, was abolished by mutation of the ICE and enhanced by mutation of the Bcl6 site. These findings demonstrate a dynamic and coordinated regulation of nuclear levels and acetylation status of trans-acting factors critical in determining the off/on state of the RGS4 promoter.
Collapse
Affiliation(s)
| | - Jie Huang
- From the Departments of Pharmacology and
| | - Tapan K. Chatterjee
- the Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio 45221
| | - Erik Twait
- Surgery, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242 and
| | | |
Collapse
|
35
|
Cloning and characterization of rabbit Rgs4 promoter in gut smooth muscle. Gene 2009; 451:45-53. [PMID: 19945517 DOI: 10.1016/j.gene.2009.11.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2009] [Revised: 11/19/2009] [Accepted: 11/19/2009] [Indexed: 11/23/2022]
Abstract
Regulator of G-protein signaling 4 (Rgs4) regulates the strength and duration of G-protein signaling, and plays an important role in cardiac development, smooth muscle contraction and psychiatric disorders. Rgs4 expression is regulated at both mRNA and protein levels. In order to examine the transcriptional mechanism of Rgs4 expression, we have cloned and characterized rabbit Rgs4 promoter. The coding sequence of rabbit Rgs4 was obtained by degenerative RT-PCR and used for Northern blot and 5'-RACE analysis. A single transcript was identified in rabbit colonic smooth muscle cells. The 5'-untranslated region (UTR) extended 120 bp nucleotides upstream of the Rgs4 start codon. A putative promoter sequence (1389 bp) showed a consensus TATA box and cis-acting binding sites for several potential transcriptional factors. Reporter gene assay identified strong promoter activity in various cell types. Further analysis by deletion mutagenesis suggested that the proximal region had a highest core promoter activity while the distal region is suppressive. IL-1beta significantly increased the promoter activity. The in vitro and in vivo binding activities for NF-kappaB transcription factor were validated by electrophoretic mobility shift assay and chromatin immunoprecipitation assay respectively. Mutation of NF-kappaB site reduced the promoter activity. These data suggest that the cloned rabbit Rgs4 promoter is functionally active and NF-kappaB binding site possesses enhancer activity in regulating Rgs4 transcription. Our studies provide an important basis for further understanding of Rgs4 regulation and function in different diseases.
Collapse
|
36
|
Chandras C, Koutmani Y, Kokkotou E, Pothoulakis C, Karalis KP. Activation of phosphatidylinositol 3-kinase/protein kinase B by corticotropin-releasing factor in human monocytes. Endocrinology 2009; 150:4606-14. [PMID: 19628576 PMCID: PMC2754688 DOI: 10.1210/en.2008-1810] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Corticotropin-releasing factor (CRF) exerts proinflammatory effects in peripheral tissues, whereas the intracellular pathways mediating these effects have not been completely characterized yet. We have previously shown that CRF induces nuclear factor-kappaB DNA-binding activity in mouse and human leukocytes. Here we demonstrate that in the human monocytic THP-1 cells, CRF activates the phosphatidylinositol 3-kinase (PI3K)/Akt and ERK1/2 pathways. These effects of CRF are mediated by corticotropin-releasing factor receptor 2 (CRF2), as suggested by their abolishment after treatment with the specific CRF2 antagonist, astressin 2B. The CRF-mediated PI3K/Akt activation induces cell survival as suggested by the stimulation of the antiapoptotic factor Bcl-2. ERK1/2 activation results in up-regulation of IL-8 expression, an effect inhibited by the CRF-induced activation of PI3K/Akt. These studies demonstrate novel effects of CRF in human monocytes mediated by the activation of PI3K/Akt. Moreover, they reveal pathway-specific effects of the CRF/CRF2 system in chemokine activation and cell survival that may be of importance for the development of novel therapeutics for inflammatory diseases.
Collapse
Affiliation(s)
- Christina Chandras
- Division of Endocrinology, Children's Hospital, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02115, USA
| | | | | | | | | |
Collapse
|