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Zhao L, Hu H, Zhang L, Liu Z, Huang Y, Liu Q, Jin L, Zhu M, Zhang L. Inflammation in diabetes complications: molecular mechanisms and therapeutic interventions. MedComm (Beijing) 2024; 5:e516. [PMID: 38617433 PMCID: PMC11014467 DOI: 10.1002/mco2.516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 02/16/2024] [Accepted: 02/21/2024] [Indexed: 04/16/2024] Open
Abstract
At present, diabetes mellitus (DM) has been one of the most endangering healthy diseases. Current therapies contain controlling high blood sugar, reducing risk factors like obesity, hypertension, and so on; however, DM patients inevitably and eventually progress into different types of diabetes complications, resulting in poor quality of life. Unfortunately, the clear etiology and pathogenesis of diabetes complications have not been elucidated owing to intricate whole-body systems. The immune system was responsible to regulate homeostasis by triggering or resolving inflammatory response, indicating it may be necessary to diabetes complications. In fact, previous studies have been shown inflammation plays multifunctional roles in the pathogenesis of diabetes complications and is attracting attention to be the meaningful therapeutic strategy. To this end, this review systematically concluded the current studies over the relationships of susceptible diabetes complications (e.g., diabetic cardiomyopathy, diabetic retinopathy, diabetic peripheral neuropathy, and diabetic nephropathy) and inflammation, ranging from immune cell response, cytokines interaction to pathomechanism of organ injury. Besides, we also summarized various therapeutic strategies to improve diabetes complications by target inflammation from special remedies to conventional lifestyle changes. This review will offer a panoramic insight into the mechanisms of diabetes complications from an inflammatory perspective and also discuss contemporary clinical interventions.
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Affiliation(s)
- Lu Zhao
- Department of Biology and MedicineCollege of Life Science, Zhejiang Chinese Medical UniversityHangzhouChina
| | - Haoran Hu
- Department of Biology and MedicineCollege of Life Science, Zhejiang Chinese Medical UniversityHangzhouChina
| | - Lin Zhang
- Department of Biology and MedicineCollege of Life Science, Zhejiang Chinese Medical UniversityHangzhouChina
| | - Zheting Liu
- Department of Biology and MedicineCollege of Life Science, Zhejiang Chinese Medical UniversityHangzhouChina
| | - Yunchao Huang
- Department of Biology and MedicineCollege of Life Science, Zhejiang Chinese Medical UniversityHangzhouChina
| | - Qian Liu
- National Demonstration Center for Experimental Traditional Chinese Medicines Education (Zhejiang Chinese Medical University)College of Pharmaceutical Science, Zhejiang Chinese Medical UniversityHangzhouChina
| | - Liang Jin
- Department of Biology and MedicineCollege of Life Science, Zhejiang Chinese Medical UniversityHangzhouChina
- Shanghai Key Laboratory of Compound Chinese Medicines, The Ministry of Education Key Laboratory for Standardization of Chinese Medicines, Institute of Chinese Materia MedicaShanghai University of Traditional Chinese MedicineShanghaiChina
| | - Meifei Zhu
- Department of Critical Care MedicineThe First Affiliated Hospital of Zhejiang Chinese Medical University (Zhejiang Provincial Hospital of Chinese Medicine)HangzhouChina
| | - Ling Zhang
- Department of Biology and MedicineCollege of Life Science, Zhejiang Chinese Medical UniversityHangzhouChina
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Xia R, Fang N, Yang Y, Xu F, Zhang L, Ji S. PM2.5 promotes apoptosis of alveolar epithelial cells via targeting ROS/p38 signaling pathway and thus leads to emphysema in mice. Minerva Med 2023; 114:652-657. [PMID: 32491296 DOI: 10.23736/s0026-4806.20.06652-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND The aim of this study was to uncover the ability of PM2.5 exposure to induce apoptosis in alveolar epithelial cells by stimulating excessive production of reactive oxygen species (ROS), thus activating p38 to result in emphysema in mice. METHODS Male BALB/c mice with 6-8-week-old were exposed to 200 TPM mg/L PM2.5 for 12 weeks. Lung tissues of mice were harvested after sacrifice. Hematoxylin and eosin staining was conducted for observing alveolar structure change. Protein levels of p-p38 and p38, as well as ROS level in mouse liver tissues were determined. A549 cells were exposed to different doses of PM2.5, followed by ROS detection, protein level detection of p-p38 and p38, and apoptosis determination. After transfection of si-p38, protein level of clv-caspase3 and apoptotic rate in PM2.5-exposed A549 cells were assessed. RESULTS After 12-week exposure to PM2.5, enlarged alveolar space, elevated ROS level in lung tissues and activated p38 were observed in mice. In PM2.5-exposed A549 cells, ROS level, p-p38 expression and apoptotic rate were dose-dependently enhanced. The antioxidant NAC reversed the above changes in PM2.5-exposed A549 cells. Silence of p38 reversed the enhanced clv-claspase3 level and apoptotic rate in PM2.5-exposed A549 cells. CONCLUSIONS PM2.5 exposure elevates ROS level in lung tissues, and activates p38, thus leading to apoptosis of alveolar epithelial cells. PM2.5 finally results in the development of emphysema in mice.
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Affiliation(s)
- Ruixue Xia
- Department of Respiratory and Critical Care Medicine, Henan University Huaihe Hospital, Kaifeng, China
| | - Na Fang
- Cell Signal Transduction Laboratory and Institute of Biomedical Informatics, School of Basic Medical Sciences, Henan University, Kaifeng, China
| | - Yanjie Yang
- Cell Signal Transduction Laboratory and Institute of Biomedical Informatics, School of Basic Medical Sciences, Henan University, Kaifeng, China
| | - Feng Xu
- Department of Respiratory and Critical Care Medicine, Henan University Huaihe Hospital, Kaifeng, China
| | - Lingge Zhang
- Cell Signal Transduction Laboratory and Institute of Biomedical Informatics, School of Basic Medical Sciences, Henan University, Kaifeng, China
| | - Shaoping Ji
- Cell Signal Transduction Laboratory and Institute of Biomedical Informatics, School of Basic Medical Sciences, Henan University, Kaifeng, China -
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Bi XJ, Lv YQ, Yang XH, Ge Y, Han H, Feng JS, Zhang M, Chen L, Xu MZ, Guan FY. A New Berberine Preparation Protects Pancreatic Islet Cells from Apoptosis Mediated by Inhibition of Phospholipase A2/p38 MAPK Pathway. Bull Exp Biol Med 2022; 173:346-353. [DOI: 10.1007/s10517-022-05547-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Indexed: 11/30/2022]
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Kassouf T, Sumara G. Impact of Conventional and Atypical MAPKs on the Development of Metabolic Diseases. Biomolecules 2020; 10:biom10091256. [PMID: 32872540 PMCID: PMC7563211 DOI: 10.3390/biom10091256] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 02/06/2023] Open
Abstract
The family of mitogen-activated protein kinases (MAPKs) consists of fourteen members and has been implicated in regulation of virtually all cellular processes. MAPKs are divided into two groups, conventional and atypical MAPKs. Conventional MAPKs are further classified into four sub-families: extracellular signal-regulated kinases 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK1, 2 and 3), p38 (α, β, γ, δ), and extracellular signal-regulated kinase 5 (ERK5). Four kinases, extracellular signal-regulated kinase 3, 4, and 7 (ERK3, 4 and 7) as well as Nemo-like kinase (NLK) build a group of atypical MAPKs, which are activated by different upstream mechanisms than conventional MAPKs. Early studies identified JNK1/2 and ERK1/2 as well as p38α as a central mediators of inflammation-evoked insulin resistance. These kinases have been also implicated in the development of obesity and diabetes. Recently, other members of conventional MAPKs emerged as important mediators of liver, skeletal muscle, adipose tissue, and pancreatic β-cell metabolism. Moreover, latest studies indicate that atypical members of MAPK family play a central role in the regulation of adipose tissue function. In this review, we summarize early studies on conventional MAPKs as well as recent findings implicating previously ignored members of the MAPK family. Finally, we discuss the therapeutic potential of drugs targeting specific members of the MAPK family.
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Jiang GX, Jiang QY, Mo HX, Li L, Wang MY. Electroacupuncture for pain relief in labour inhibits spinal p38 MAPK-mediated prostaglandin E2 release and uterine prostaglandin E2 receptor expression in rats. Acupunct Med 2019; 37:116-124. [PMID: 30977668 DOI: 10.1136/acupmed-2017-011559] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND p38 mitogen-activated protein kinase (p38 MAPK) activation involves the release of prostaglandin E2 (PGE2) and hyperalgesia. We have previously reported that electroacupuncture (EA) relieves labour pain, but the potential mechanisms remain unclear. OBJECTIVE To observe the effects of EA on labour pain intensity, serum PGE2 levels and the p38 MAPK signalling pathway in rats during labour. METHODS Female rats copulated with male rats to induce pregnancy, and then received castor oil to trigger labour. During labour, rats remained untreated (Control group, n=30) or were treated with remifentanil (n=30) or EA at Jiaji (n=30) or SP6+LI4 (n=30), respectively. The warm water tail-flick test was used to assess labour pain. Serum PGE2 levels were measured by ELISA. Protein expression of prostaglandin E2 receptor (PGER2), p38 MAPK and phospholipase A2 (PLA2) were analysed by Western blotting, and mRNA levels were measured by real-time PCR. RESULTS EA treatment at Jiaji or SP6+LI4 significantly relieved labour pain, decreased serum PGE2 levels and inhibited protein and gene expression of PGER2 in the myometrium. Moreover, EA reduced protein expression of PLA2 and p38 MAPK, and inhibited phosphorylation of p38 MAPK in the lumbar spinal cord but not in the cerebral grey matter. Additionally, EA markedly decreased mRNA levels of p38 MAPK in the lumbar spinal cord and significantly reduced PLA2-IV mRNA levels in both the lumbar spinal cord and cerebral grey matter. CONCLUSIONS This study indicates that EA relieves labour pain through, at least in part, inhibition of spinal p38 MAPK-mediated PGE2 release and uterine PGER2 expression in rats.
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Affiliation(s)
- Gui-Xiu Jiang
- 1 Medical School, Jinan University, Guangzhou, China
| | - Qiu-Yan Jiang
- 2 The First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, China
| | - Hai-Xia Mo
- 2 The First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, China
| | - Li Li
- 2 The First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, China
| | - Meng-Ying Wang
- 2 The First Affiliated Hospital, Guangxi University of Chinese Medicine, Nanning, China
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Wei X, Gu N, Feng N, Guo X, Ma X. Inhibition of p38 mitogen-activated protein kinase exerts a hypoglycemic effect by improving β cell function via inhibition of β cell apoptosis in db/db mice. J Enzyme Inhib Med Chem 2018; 33:1494-1500. [PMID: 30284474 PMCID: PMC6179047 DOI: 10.1080/14756366.2018.1477138] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
The p38 mitogen-activated protein kinase (MAPK) pathway is involved in endoplasmic reticulum stress (ERS) and inflammation, which may play an important role in the pathogenesis of type 2 diabetes (T2DM). This study aimed to investigate whether p38 MAPK contributes to the pathogenesis of T2DM. 6-week-old female db/db mice were randomly assigned to Dmo and Dmi groups, and C57 mice were assigned as controls. The Dmi group was gavaged with the p38 MAPK inhibitor SB203580 for 9 weeks, and the effects on β cell dysfunction and apoptosis were investigated. db/db mice showed higher food intake, body mass, fasting glucose, and plasma insulin levels than C57 mice. After SB203580 administration, blood glucose was significantly lower. HOMA β and HOMA IR were improved. Islet mRNA expression levels of the ERS markers were lower. P38 MAPK inhibition reduced blood glucose and improved β cell function, at least in part by reducing β cell apoptosis.
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Affiliation(s)
- Xiaowei Wei
- a Endocrinology Department , First Hospital, Peking University , Beijing , China
| | - Nan Gu
- a Endocrinology Department , First Hospital, Peking University , Beijing , China
| | - Nan Feng
- a Endocrinology Department , First Hospital, Peking University , Beijing , China
| | - Xiaohui Guo
- a Endocrinology Department , First Hospital, Peking University , Beijing , China
| | - Xiaowei Ma
- a Endocrinology Department , First Hospital, Peking University , Beijing , China
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Rashid K, Chowdhury S, Ghosh S, Sil PC. Curcumin attenuates oxidative stress induced NFκB mediated inflammation and endoplasmic reticulum dependent apoptosis of splenocytes in diabetes. Biochem Pharmacol 2017; 143:140-155. [PMID: 28711624 DOI: 10.1016/j.bcp.2017.07.009] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 07/10/2017] [Indexed: 12/31/2022]
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3D-QSAR studies on disubstituted dibenzosuberone derivatives as p38α MAP kinase inhibitors using CoMFA and COMSIA. Med Chem Res 2016. [DOI: 10.1007/s00044-016-1642-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Caporarello N, Salmeri M, Scalia M, Motta C, Parrino C, Frittitta L, Olivieri M, Cristaldi M, Avola R, Bramanti V, Toscano MA, Anfuso CD, Lupo G. Cytosolic and Calcium-Independent Phospholipases A2 Activation and Prostaglandins E2 Are Associated with Escherichia coli-Induced Reduction of Insulin Secretion in INS-1E Cells. PLoS One 2016; 11:e0159874. [PMID: 27631977 PMCID: PMC5024995 DOI: 10.1371/journal.pone.0159874] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 09/02/2016] [Indexed: 01/01/2023] Open
Abstract
It is suspected that microbial infections take part in the pathogenesis of diabetes mellitus type 1 (T1DM). Glucose-induced insulin secretion is accompanied by the release of free arachidonic acid (AA) mainly by cytosolic- and calcium independent phospholipases A2 (cPLA2 and iPLA2). Insulinoma cell line (INS-1E) was infected with E. coli isolated from the blood culture of a patient with sepsis. Invasion assay, Scanning Electron Microscopy and Transmission Electron Microscopy demonstrated the capacity of E. coli to enter cells, which was reduced by PLA2 inhibitors. Glucose-induced insulin secretion was significantly increased after acute infection (8h) but significantly decreased after chronic infection (72h). PLA2 activities, cPLA2, iPLA2, phospho-cPLA2, and COX-2 expressions were increased after acute and, even more, after chronic E. coli infection. The silencing of the two isoforms of PLA2s, with specific cPLA2- or iPLA2-siRNAs, reduced insulin secretion after acute infection and determined a rise in insulin release after chronic infection. Prostaglandins E2 (PGE2) production was significantly elevated in INS-1E after long-term E. coli infection and the restored insulin secretion in presence of L798106, a specific EP3 antagonist, and NS-398, a COX-2 inhibitor, and the reduction of insulin secretion in presence of sulprostone, a specific EP3 agonist, revealed their involvement in the effects triggered by bacterial infection. The results obtained demonstrated that cPLA2 and iPLA2 play a key role in insulin secretion process after E. coli infection. The high concentration of AA released is transformed into PGE2, which could be responsible for the reduced insulin secretion.
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Affiliation(s)
- Nunzia Caporarello
- Dept. of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Mario Salmeri
- Dept. of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Marina Scalia
- Dept. of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Carla Motta
- Dept. of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Cristina Parrino
- Dept. of Clinical and Experimental Medicine, School of Medicine, University of Catania, Catania, Italy
| | - Lucia Frittitta
- Dept. of Clinical and Experimental Medicine, School of Medicine, University of Catania, Catania, Italy
| | - Melania Olivieri
- Dept. of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Martina Cristaldi
- Dept. of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Roberto Avola
- Dept. of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Vincenzo Bramanti
- Dept. of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Maria Antonietta Toscano
- Dept. of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Carmelina Daniela Anfuso
- Dept. of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Gabriella Lupo
- Dept. of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
- * E-mail:
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10
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Wang X, Wang B, Li Z, Zhu G, Heng L, Zhu X, Yang Q, Ma J, Gao G. Neuroprotection effect of Y-27632 against H2O2-induced cell apoptosis of primary cultured cortical neurons. RSC Adv 2016. [DOI: 10.1039/c6ra03284b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Y-27632 protects the cortical neurons from H2O2-induced apoptosis by inhibiting oxidative stress and activation of JNK and p38 MAPKs pathways.
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Affiliation(s)
- Xingqin Wang
- Department of Neurosurgery
- Tangdu Hospital
- Fourth Military Medical University
- Xi'an 710038
- China
| | - Bao Wang
- Department of Neurosurgery
- Tangdu Hospital
- Fourth Military Medical University
- Xi'an 710038
- China
| | - Zhenzhen Li
- Department of Burns and Cutaneous Surgery
- Xijing Hospital
- Fourth Military Medical University
- Xi'an 710032
- China
| | - Gang Zhu
- Department of Neurosurgery
- Tangdu Hospital
- Fourth Military Medical University
- Xi'an 710038
- China
| | - Lijun Heng
- Department of Neurosurgery
- Tangdu Hospital
- Fourth Military Medical University
- Xi'an 710038
- China
| | - Xianke Zhu
- Department of Orthopedics
- No. 150 Central Hospital of PLA
- Luoyang
- China
| | - Qian Yang
- Department of Neurosurgery
- Tangdu Hospital
- Fourth Military Medical University
- Xi'an 710038
- China
| | - Jie Ma
- Department of Neurosurgery
- Tangdu Hospital
- Fourth Military Medical University
- Xi'an 710038
- China
| | - Guodong Gao
- Department of Neurosurgery
- Tangdu Hospital
- Fourth Military Medical University
- Xi'an 710038
- China
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Caporarello N, Salmeri M, Scalia M, Motta C, Parrino C, Frittitta L, Olivieri M, Toscano MA, Anfuso CD, Lupo G. Role of cytosolic and calcium independent phospholipases A(2) in insulin secretion impairment of INS-1E cells infected by S. aureus. FEBS Lett 2015; 589:3969-76. [PMID: 26632509 DOI: 10.1016/j.febslet.2015.11.035] [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: 10/21/2015] [Accepted: 11/19/2015] [Indexed: 10/22/2022]
Abstract
Cytosolic PLA2 (cPLA2) and Ca(2+)-independent PLA2 (iPLA2) play a significant role in insulin β-cells secretion. Bacterial infections may be responsible of the onset of diabetes. The mechanism by which Staphylococcus aureus infection of INS-1 cells alters glucose-induced insulin secretion has been examined. After acute infection, insulin secretion and PLA2 activities significantly increased. Moreover, increased expressions of phospho-cPLA2, phospho-PKCα and phospho-ERK 1/2 were observed. Chronic infection causes a decrease in insulin release and a significant increase of iPLA2 and COX-2 protein expression. Moreover, insulin secretion in infected cells could be restored using specific siRNAs against iPLA2 isoform and specific COX-2 inhibitor.
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Affiliation(s)
- N Caporarello
- Dept. of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Italy
| | - M Salmeri
- Dept. of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Italy
| | - M Scalia
- Dept. of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Italy
| | - C Motta
- Dept. of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Italy
| | - C Parrino
- Dept. of Clinical and Experimental Medicine, School of Medicine, University of Catania, Italy
| | - L Frittitta
- Dept. of Clinical and Experimental Medicine, School of Medicine, University of Catania, Italy
| | - M Olivieri
- Dept. of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Italy
| | - M A Toscano
- Dept. of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Italy
| | - C D Anfuso
- Dept. of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Italy
| | - G Lupo
- Dept. of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Italy.
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Lee SH, Yumnam S, Hong GE, Raha S, Saralamma VVG, Lee HJ, Heo JD, Lee SJ, Lee WS, Kim EH, Park HS, Kim GS. Flavonoids of Korean Citrus aurantium L. Induce Apoptosis via Intrinsic Pathway in Human Hepatoblastoma HepG2 Cells. Phytother Res 2015; 29:1940-9. [PMID: 26439681 DOI: 10.1002/ptr.5488] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 08/28/2015] [Accepted: 09/15/2015] [Indexed: 01/29/2023]
Abstract
Korean Citrus aurantium L. has long been used as a medicinal herb for its anti-inflammatory, antioxidant, and anticancer properties. The present study investigates the anticancer role of flavonoids extracted from C. aurantium on human hepatoblastoma cell, HepG2. The Citrus flavonoids inhibit the proliferation of HepG2 cells in a dose-dependent manner. This result was consistent with the in vivo xenograft results. Apoptosis was detected by cell morphology, cell cycle analysis, and immunoblot. Flavonoids decreased the level of pAkt and other downstream targets of phosphoinositide-3-kinase/Akt pathway - P-4EBP1 and P-p70S6K. The expressions of cleaved caspase 3, Bax, and Bak were increased, while those of Bcl-2 and Bcl-xL were decreased with an increase in the expression of Bax/Bcl-xL ratio in treated cells. Loss of mitochondrial membrane potential was also observed in flavonoid-treated HepG2 cells. It was also observed that the P-p38 protein level was increased both dose and time dependently in flavonoid-treated cells. Collectively, these results suggest that flavonoid extracted from Citrus inhibits HepG2 cell proliferation by inducing apoptosis via an intrinsic pathway. These findings suggest that flavonoids extracted from C. aurantium L. are potential chemotherapeutic agents against liver cancer.
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Affiliation(s)
- Seung Hwan Lee
- Research Institute of Life Science, College of Veterinary Medicine (BK21 plus project), Gyeongsang National University, Gazwa, Jinju, 660-701, Korea
| | - Silvia Yumnam
- Research Institute of Life Science, College of Veterinary Medicine (BK21 plus project), Gyeongsang National University, Gazwa, Jinju, 660-701, Korea
| | - Gyeong Eun Hong
- Research Institute of Life Science, College of Veterinary Medicine (BK21 plus project), Gyeongsang National University, Gazwa, Jinju, 660-701, Korea
| | - Suchismita Raha
- Research Institute of Life Science, College of Veterinary Medicine (BK21 plus project), Gyeongsang National University, Gazwa, Jinju, 660-701, Korea
| | - Venu Venkatarame Gowda Saralamma
- Research Institute of Life Science, College of Veterinary Medicine (BK21 plus project), Gyeongsang National University, Gazwa, Jinju, 660-701, Korea
| | - Ho Jeong Lee
- Research Institute of Life Science, College of Veterinary Medicine (BK21 plus project), Gyeongsang National University, Gazwa, Jinju, 660-701, Korea
| | - Jeong Doo Heo
- Gyeongnam Department of Environment Toxicology and Chemistry, Toxicity Screening Research Center, Korea Institute of Toxicology, Jinju, Korea
| | - Sang Joon Lee
- Gyeongnam Department of Environment Toxicology and Chemistry, Toxicity Screening Research Center, Korea Institute of Toxicology, Jinju, Korea
| | - Won-Sup Lee
- Department of Internal Medicine, Institute of Health Sciences, Gyeongsang National University School of Medicine, Gyeongnam Regional Cancer Center, Gyeongsang National University Hospital, Jinju, 660-702, Korea
| | - Eun-Hee Kim
- Department of Nursing Science, International University of Korea, Jinju, 660-759, Korea
| | - Hyeon Soo Park
- Research Institute of Life Science, College of Veterinary Medicine (BK21 plus project), Gyeongsang National University, Gazwa, Jinju, 660-701, Korea
| | - Gon Sup Kim
- Research Institute of Life Science, College of Veterinary Medicine (BK21 plus project), Gyeongsang National University, Gazwa, Jinju, 660-701, Korea
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Arginine-induced insulin secretion in endoplasmic reticulum. Biochem Biophys Res Commun 2015; 466:717-22. [PMID: 26348775 DOI: 10.1016/j.bbrc.2015.09.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 09/03/2015] [Indexed: 01/31/2023]
Abstract
Arginine, a semi-essential amino acid, is known as one of the most strongest insulin secretagogues in a glucose-dependent manner, but major mechanism is unknown. Arginine induced insulin secretion in mice as well as β cell line, NIT-1, in which more than 90% of intracellular insulin is prionsulin without arginine cultivation. Arginine administration reduced prionsulin amount in 30 s, then insulin is secreted from NIT1 cells. These data indicated that the target factor(s) for arginine-induced insulin secretion located in endoplasmic reticulum (ER). We established the screening system for identifying the arginine mimetics. Brazilian propolis, not Chinese propolis, induced insulin secretion. To identify target factor(s) of arginine induced insulin secretion, our previous study was that nanobeads technology facilitated us to purify chemical-target factors. This time we chose the other way, proinsulin associating factor purification and arginine-immobilized agarose. Three proinsulin associating factors and 5 arginine interacting factors were identified. Among theses factors, Calnexin (CNX) was the only one factor, which belonged to both groups, suggesting that CNX might play a key role in arginine-induced insulin secretion in ER.
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Ramanadham S, Ali T, Ashley JW, Bone RN, Hancock WD, Lei X. Calcium-independent phospholipases A2 and their roles in biological processes and diseases. J Lipid Res 2015; 56:1643-68. [PMID: 26023050 DOI: 10.1194/jlr.r058701] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Indexed: 12/24/2022] Open
Abstract
Among the family of phospholipases A2 (PLA2s) are the Ca(2+)-independent PLA2s (iPLA2s) and they are designated group VI iPLA2s. In relation to secretory and cytosolic PLA2s, the iPLA2s are more recently described and details of their expression and roles in biological functions are rapidly emerging. The iPLA2s or patatin-like phospholipases (PNPLAs) are intracellular enzymes that do not require Ca(2+) for activity, and contain lipase (GXSXG) and nucleotide-binding (GXGXXG) consensus sequences. Though nine PNPLAs have been recognized, PNPLA8 (membrane-associated iPLA2γ) and PNPLA9 (cytosol-associated iPLA2β) are the most widely studied and understood. The iPLA2s manifest a variety of activities in addition to phospholipase, are ubiquitously expressed, and participate in a multitude of biological processes, including fat catabolism, cell differentiation, maintenance of mitochondrial integrity, phospholipid remodeling, cell proliferation, signal transduction, and cell death. As might be expected, increased or decreased expression of iPLA2s can have profound effects on the metabolic state, CNS function, cardiovascular performance, and cell survival; therefore, dysregulation of iPLA2s can be a critical factor in the development of many diseases. This review is aimed at providing a general framework of the current understanding of the iPLA2s and discussion of the potential mechanisms of action of the iPLA2s and related involved lipid mediators.
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Affiliation(s)
- Sasanka Ramanadham
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294 Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Tomader Ali
- Undergraduate Research Office, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Jason W Ashley
- Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA 19104
| | - Robert N Bone
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294 Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294
| | - William D Hancock
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294 Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Xiaoyong Lei
- Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294 Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL 35294
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15
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Nishiura H, Yamanegi K, Kawabe M, Kato-Kogoe N, Yamada N, Nakasho K. Annexin A3 plays a role in cytoplasmic calcium oscillation by extracellular calcium in the human promyelocytic leukemia HL-60 cells differentiated by phorbol-12-myristate-13-acetate. Exp Mol Pathol 2014; 97:241-6. [PMID: 25036403 DOI: 10.1016/j.yexmp.2014.07.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Accepted: 07/15/2014] [Indexed: 10/25/2022]
Abstract
The roles of annexin A3 (ANXA3) in macrophages are not fully understood. In contrast to C5a, we have demonstrated that C-terminal ribosomal protein S19 (RP S19)-tagged S-tagged C5a (S-tagged C5a/RP S19) raises an alternative cytoplasmic calcium oscillation by extracellular calcium during macrophage migration into apoptotic cells. We here differentiated human promyelocytic leukemia HL-60 cells bearing with either control sense RNA and shRNA for ANXA3 mRNA or a vector cDNA with or without ANXA3 cDNA into macrophage-like cells by phorbol-12-myristate-13-acetate and found that a fluorescence ratio (340 nm/380 nm) upon the S-tagged C5a/RP S19-induced alternative cytoplasmic calcium oscillation by extracellular calcium was an equilateral association with a dose of ANXA3. Moreover, the ANXA3-dependent modification was partially reflected upon the S-tagged C5a-induced classical cytoplasmic calcium oscillation by both intracellular calcium and extracellular calcium. ANXA3 seems to extend the C5aR-mediated cytoplasmic calcium oscillation by extracellular calcium at least in the HL-60 macrophage-like cells.
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Affiliation(s)
- Hiroshi Nishiura
- Division of Functional Pathology, Department of Pathology, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan.
| | - Koji Yamanegi
- Division of Functional Pathology, Department of Pathology, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan
| | - Mutsuki Kawabe
- Department of Dentistry and Oral Surgery, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan
| | - Nahoko Kato-Kogoe
- Division of Functional Pathology, Department of Pathology, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan
| | - Naoko Yamada
- Division of Functional Pathology, Department of Pathology, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan
| | - Keiji Nakasho
- Division of Functional Pathology, Department of Pathology, Hyogo College of Medicine, Nishinomiya, Hyogo 663-8501, Japan
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16
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Liu H, Chen X, Han Y, Li C, Chen P, Su S, Zhang Y, Pan Z. Rho kinase inhibition by fasudil suppresses lipopolysaccharide-induced apoptosis of rat pulmonary microvascular endothelial cells via JNK and p38 MAPK pathway. Biomed Pharmacother 2014; 68:267-75. [DOI: 10.1016/j.biopha.2013.12.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 12/10/2013] [Indexed: 10/25/2022] Open
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17
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Song H, Wohltmann M, Tan M, Ladenson JH, Turk J. Group VIA phospholipase A2 mitigates palmitate-induced β-cell mitochondrial injury and apoptosis. J Biol Chem 2014; 289:14194-210. [PMID: 24648512 DOI: 10.1074/jbc.m114.561910] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Palmitate (C16:0) induces apoptosis of insulin-secreting β-cells by processes that involve generation of reactive oxygen species, and chronically elevated blood long chain free fatty acid levels are thought to contribute to β-cell lipotoxicity and the development of diabetes mellitus. Group VIA phospholipase A2 (iPLA2β) affects β-cell sensitivity to apoptosis, and here we examined iPLA2β effects on events that occur in β-cells incubated with C16:0. Such events in INS-1 insulinoma cells were found to include activation of caspase-3, expression of stress response genes (C/EBP homologous protein and activating transcription factor 4), accumulation of ceramide, loss of mitochondrial membrane potential, and apoptosis. All of these responses were blunted in INS-1 cells that overexpress iPLA2β, which has been proposed to facilitate repair of oxidized mitochondrial phospholipids, e.g. cardiolipin (CL), by excising oxidized polyunsaturated fatty acid residues, e.g. linoleate (C18:2), to yield lysophospholipids, e.g. monolysocardiolipin (MLCL), that can be reacylated to regenerate the native phospholipid structures. Here the MLCL content of mouse pancreatic islets was found to rise with increasing iPLA2β expression, and recombinant iPLA2β hydrolyzed CL to MLCL and released oxygenated C18:2 residues from oxidized CL in preference to native C18:2. C16:0 induced accumulation of oxidized CL species and of the oxidized phospholipid (C18:0/hydroxyeicosatetraenoic acid)-glycerophosphoethanolamine, and these effects were blunted in INS-1 cells that overexpress iPLA2β, consistent with iPLA2β-mediated removal of oxidized phospholipids. C16:0 also induced iPLA2β association with INS-1 cell mitochondria, consistent with a role in mitochondrial repair. These findings indicate that iPLA2β confers significant protection of β-cells against C16:0-induced injury.
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Affiliation(s)
- Haowei Song
- From the Mass Spectrometry Resource, Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine and
| | - Mary Wohltmann
- From the Mass Spectrometry Resource, Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine and
| | - Min Tan
- From the Mass Spectrometry Resource, Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine and
| | - Jack H Ladenson
- Division of Laboratory and Genomic Medicine, Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri 63110
| | - John Turk
- From the Mass Spectrometry Resource, Division of Endocrinology, Metabolism, and Lipid Research, Department of Medicine and
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Kooptiwut S, Mahawong P, Hanchang W, Semprasert N, Kaewin S, Limjindaporn T, Yenchitsomanus PT. Estrogen reduces endoplasmic reticulum stress to protect against glucotoxicity induced-pancreatic β-cell death. J Steroid Biochem Mol Biol 2014; 139:25-32. [PMID: 24120916 DOI: 10.1016/j.jsbmb.2013.09.018] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 09/27/2013] [Accepted: 09/30/2013] [Indexed: 02/07/2023]
Abstract
Estrogen can improve glucose homeostasis not only in diabetic rodents but also in humans. However, the molecular mechanism by which estrogen prevents pancreatic β-cell death remains unclear. To investigate this issue, INS-1 cells, a rat insulinoma cell line, were cultured in medium with either 11.1mM or 40mM glucose in the presence or the absence of estrogen. Estrogen significantly reduced apoptotic β-cell death by decreasing nitrogen-induced oxidative stress and the expression of the ER stress markers GRP 78, ATF6, P-PERK, PERK, uXBP1, sXBP1, and CHOP in INS-1 cells after prolonged culture in medium with 40mM glucose. In contrast, estrogen increased the expression of survival proteins, including sarco/endoplasmic reticulum Ca(2+) ATPase (SERCA-2), Bcl-2, and P-p38, in INS-1 cells after prolonged culture in medium with 40mM glucose. The cytoprotective effect of estrogen was attenuated by addition of the estrogen receptor (ERα and ERβ) antagonist ICI 182,780 and the estrogen membrane receptor inhibitor G15. We showed that estrogen decreases not only oxidative stress but also ER stress to protect against 40mM glucose-induced pancreatic β-cell death.
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Affiliation(s)
- Suwattanee Kooptiwut
- Department of Physiology, Faculty of Medicine Siriraj Hospital, Mahidol University, 2 Prannok Road, Bangkok 10700, Thailand.
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19
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Sui X, Kong N, Ye L, Han W, Zhou J, Zhang Q, He C, Pan H. p38 and JNK MAPK pathways control the balance of apoptosis and autophagy in response to chemotherapeutic agents. Cancer Lett 2013; 344:174-9. [PMID: 24333738 DOI: 10.1016/j.canlet.2013.11.019] [Citation(s) in RCA: 718] [Impact Index Per Article: 65.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 11/09/2013] [Accepted: 11/19/2013] [Indexed: 01/01/2023]
Abstract
The Mitogen Activated Protein Kinase (MAPK) signaling plays a critical role in the outcome and the sensitivity to anticancer therapies. Activated MAPK can transmit extracellular signals to regulate cell growth, proliferation, differentiation, migration, apoptosis and so on. Apoptosis as well as macroautophagy (hereafter referred to as autophagy) can be induced by extracellular stimuli such the treatment of chemotherapeutic agents, resulting in different cell response to these drugs. However, the molecular mechanisms mediating these two cellular processes remain largely unknown. Recently, several studies provide new insights into p38 and JNK MAPK pathways function in the control of the balance of autophagy and apoptosis in response to genotoxic stress. Our increased understanding of the role of p38 and JNK MAPK pathways in regulating the balance of autophagy and apoptosis will hopefully provide prospective strategies for cancer therapy.
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Affiliation(s)
- Xinbing Sui
- Department of Medical Oncology, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, China; Biomedical Research Center and Key Laboratory of Biotherapy of Zhejiang Province, Hangzhou, China
| | - Na Kong
- Department of Medical Oncology, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, China; Biomedical Research Center and Key Laboratory of Biotherapy of Zhejiang Province, Hangzhou, China
| | - Li Ye
- Department of General Medicine, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, China
| | - Weidong Han
- Department of Medical Oncology, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, China; Biomedical Research Center and Key Laboratory of Biotherapy of Zhejiang Province, Hangzhou, China
| | - Jichun Zhou
- Department of Surgical Oncology, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, China
| | - Qin Zhang
- Department of Gastrointestinal Surgery, Zhejiang Provincial People's Hospital, Hangzhou, China.
| | - Chao He
- Biomedical Research Center and Key Laboratory of Biotherapy of Zhejiang Province, Hangzhou, China; Department of Colorectal Surgery, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, China.
| | - Hongming Pan
- Department of Medical Oncology, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou, China; Biomedical Research Center and Key Laboratory of Biotherapy of Zhejiang Province, Hangzhou, China.
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20
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Jenkins CM, Yang J, Gross RW. Mechanism-based inhibition of iPLA2β demonstrates a highly reactive cysteine residue (C651) that interacts with the active site: mass spectrometric elucidation of the mechanisms underlying inhibition. Biochemistry 2013; 52:4250-63. [PMID: 23701211 DOI: 10.1021/bi4004233] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The multifaceted roles of calcium-independent phospholipase A2β (iPLA2β) in numerous cellular processes have been extensively examined through utilization of the iPLA2-selective inhibitor (E)-6-(bromomethylene)-3-(1-naphthalenyl)-2H-tetrahydropyran-2-one (BEL). Herein, we employed accurate mass/high resolution mass spectrometry to demonstrate that the active site serine (S465) and C651 of iPLA2β are covalently cross-linked during incubations with BEL demonstrating their close spatial proximity. This cross-link results in macroscopic alterations in enzyme molecular geometry evidenced by anomalous migration of the cross-linked enzyme by SDS-PAGE. Molecular models of iPLA2β constructed from the crystal structure of iPLA2α (patatin) indicate that the distance between S465 and C651 is approximately 10 Å within the active site of iPLA2β. Kinetic analysis of the formation of the 75 kDa iPLA2β-BEL species with the (R) and (S) enantiomers of BEL demonstrated that the reaction of (S)-BEL with iPLA2β was more rapid than for (R)-BEL paralleling the enantioselectivity for the inhibition of catalysis by each inhibitor with iPLA2β. Moreover, we demonstrate that the previously identified selective acylation of iPLA2β by oleoyl-CoA occurs at C651 thereby indicating the importance of active site architecture for acylation of this enzyme. Collectively, these results identify C651 as a highly reactive nucleophilic residue within the active site of iPLA2β which is thioesterified by BEL, acylated by oleoyl-CoA, and located in close spatial proximity to the catalytic serine thereby providing important chemical insights on the mechanisms through which BEL inhibits iPLA2β and the topology of the active site.
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Affiliation(s)
- Christopher M Jenkins
- Division of Bioorganic Chemistry and Molecular Pharmacology, Washington University School of Medicine , St. Louis, Missouri 63110, USA
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21
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Magrioti V, Kokotos G. Phospholipase A2inhibitors for the treatment of inflammatory diseases: a patent review (2010 – present). Expert Opin Ther Pat 2013; 23:333-44. [DOI: 10.1517/13543776.2013.754425] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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22
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Lei X, Zhang S, Bohrer A, Barbour SE, Ramanadham S. Role of calcium-independent phospholipase A(2)β in human pancreatic islet β-cell apoptosis. Am J Physiol Endocrinol Metab 2012; 303:E1386-95. [PMID: 23074238 PMCID: PMC3774083 DOI: 10.1152/ajpendo.00234.2012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Death of β-cells due to apoptosis is an important contributor to β-cell dysfunction in both type 1 and type 2 diabetes mellitus. Previously, we described participation of the Group VIA Ca(2+)-independent phospholipase A(2) (iPLA(2)β) in apoptosis of insulinoma cells due to ER stress. To examine whether islet β-cells are similarly susceptible to ER stress and undergo iPLA(2)β-mediated apoptosis, we assessed the ER stress response in human pancreatic islets. Here, we report that the iPLA(2)β protein is expressed predominantly in the β-cells of human islets and that thapsigargin-induced ER stress promotes β-cell apoptosis, as reflected by increases in activated caspase-3 in the β-cells. Furthermore, we demonstrate that ER stress is associated with increases in islet iPLA(2)β message, protein, and activity, iPLA(2)β-dependent induction of neutral sphingomyelinase and ceramide accumulation, and subsequent loss of mitochondrial membrane potential. We also observe that basal activated caspase-3 increases with age, raising the possibility that β-cells in older human subjects have a greater susceptibility to undergo apoptotic cell death. These findings reveal for the first time expression of iPLA(2)β protein in human islet β-cells and that induction of iPLA(2)β during ER stress contributes to human islet β-cell apoptosis. We hypothesize that modulation of iPLA(2)β activity might reduce β-cell apoptosis and this would be beneficial in delaying or preventing β-cell dysfunction associated with diabetes.
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Affiliation(s)
- Xiaoyong Lei
- Dept. of Cell, Developmental, and Integrative Biology, Univ. of Alabama at Birmingham, Birmingham, AL 35294, USA
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23
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Group VIB Phospholipase A(2) promotes proliferation of INS-1 insulinoma cells and attenuates lipid peroxidation and apoptosis induced by inflammatory cytokines and oxidant agents. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2012; 2012:989372. [PMID: 23213352 PMCID: PMC3503447 DOI: 10.1155/2012/989372] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 08/20/2012] [Indexed: 01/09/2023]
Abstract
Group VIB Phospholipase A(2) (iPLA(2)γ) is distributed in membranous organelles in which β-oxidation occurs, that is, mitochondria and peroxisomes, and is expressed by insulin-secreting pancreatic islet β-cells and INS-1 insulinoma cells, which can be injured by inflammatory cytokines, for example, IL-1β and IFN-γ, and by oxidants, for example, streptozotocin (STZ) or t-butyl-hydroperoxide (TBHP), via processes pertinent to mechanisms of β-cell loss in types 1 and 2 diabetes mellitus. We find that incubating INS-1 cells with IL-1β and IFN-γ, with STZ, or with TBHP causes increased expression of iPLA(2)γ mRNA and protein. We prepared INS-1 knockdown (KD) cell lines with reduced iPLA(2)γ expression, and they proliferate more slowly than control INS-1 cells and undergo increased membrane peroxidation in response to cytokines or oxidants. Accumulation of oxidized phospholipid molecular species in STZ-treated INS-1 cells was demonstrated by LC/MS/MS scanning, and the levels in iPLA(2)γ-KD cells exceeded those in control cells. iPLA(2)γ-KD INS-1 cells also exhibited higher levels of apoptosis than control cells when incubated with STZ or with IL-1β and IFN-γ. These findings suggest that iPLA(2)γ promotes β-cell proliferation and that its expression is increased during inflammation or oxidative stress as a mechanism to mitigate membrane injury that may enhance β-cell survival.
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