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Wang P, Yang X, Zhang L, Sha S, Huang J, Peng J, Gu J, Pearson JA, Hu Y, Zhao H, Wong FS, Wang Q, Wen L. Tlr9 deficiency in B cells leads to obesity by promoting inflammation and gut dysbiosis. Nat Commun 2024; 15:4232. [PMID: 38762479 DOI: 10.1038/s41467-024-48611-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 05/02/2024] [Indexed: 05/20/2024] Open
Abstract
Toll-like receptor 9 (TLR9) recognizes bacterial, viral and self DNA and play an important role in immunity and inflammation. However, the role of TLR9 in obesity is less well-studied. Here, we generate B-cell-specific Tlr9-deficient (Tlr9fl/fl/Cd19Cre+/-, KO) B6 mice and model obesity using a high-fat diet. Compared with control mice, B-cell-specific-Tlr9-deficient mice exhibited increased fat tissue inflammation, weight gain, and impaired glucose and insulin tolerance. Furthermore, the frequencies of IL-10-producing-B cells and marginal zone B cells were reduced, and those of follicular and germinal center B cells were increased. This was associated with increased frequencies of IFNγ-producing-T cells and increased follicular helper cells. In addition, gut microbiota from the KO mice induced a pro-inflammatory state leading to immunological and metabolic dysregulation when transferred to germ-free mice. Using 16 S rRNA gene sequencing, we identify altered gut microbial communities including reduced Lachnospiraceae, which may play a role in altered metabolism in KO mice. We identify an important network involving Tlr9, Irf4 and Il-10 interconnecting metabolic homeostasis, with the function of B and T cells, and gut microbiota in obesity.
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Affiliation(s)
- Pai Wang
- Department of Gastrocolorectal Surgery, General Surgery Center, The First Hospital of Jilin University, Changchun, Jilin, China
- Section of Endocrinology, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
| | - Xin Yang
- Section of Endocrinology, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
- Department of Food Science and Technology, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
| | - Luyao Zhang
- Department of Gastrocolorectal Surgery, General Surgery Center, The First Hospital of Jilin University, Changchun, Jilin, China
- Section of Endocrinology, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
| | - Sha Sha
- Section of Endocrinology, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
- Department of Nephrology, The First Affiliated Hospital of Shandong First Medical University, Jinan, Shandong, China
| | - Juan Huang
- Section of Endocrinology, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
| | - Jian Peng
- Section of Endocrinology, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
| | - Jianlei Gu
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA
| | - James Alexander Pearson
- Section of Endocrinology, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
- Division of Infection and Immunity, School of Medicine and Systems Immunity University Research Institute, Cardiff University, Cardiff, UK
| | - Youjia Hu
- Section of Endocrinology, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA
| | - Hongyu Zhao
- Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA
| | - F Susan Wong
- Division of Infection and Immunity, School of Medicine and Systems Immunity University Research Institute, Cardiff University, Cardiff, UK
| | - Quan Wang
- Department of Gastrocolorectal Surgery, General Surgery Center, The First Hospital of Jilin University, Changchun, Jilin, China.
| | - Li Wen
- Section of Endocrinology, Department of Internal Medicine, School of Medicine, Yale University, New Haven, CT, USA.
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Alkudmani ZS, Alzailai AA, Aburisheh KH, Alshammary AF, Ali Khan I. Toll-like Receptor 9 Gene in the Development of Type 2 Diabetes Mellitus in the Saudi Arabian Population. Biology (Basel) 2023; 12:1439. [PMID: 37998038 PMCID: PMC10669332 DOI: 10.3390/biology12111439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 11/10/2023] [Accepted: 11/15/2023] [Indexed: 11/25/2023]
Abstract
Diabetes mellitus is a complex disease with a wide range of manifestations. Diabetes, notably type 2 diabetes mellitus (T2DM), is becoming more common in Saudi Arabia as a result of obesity and an aging population. T2DM is classified as a noncommunicable disease, and its incidence in the Saudi population continues to grow as a consequence of socioeconomic changes. Toll-like receptors (TLRs) are innate immune receptors that mediate the inflammatory response in diabetes mellitus. Previous studies have documented the relationship between different SNPs in the TLR9 gene in different forms of diabetes. As a result, the purpose of this study was to investigate the relationship between rs187084, rs352140, and rs5743836 SNPs in the TLR9 gene among T2DM patients in the Saudi population. This was a case-control study that included 100 T2DM cases and 100 control subjects. The three SNPs were identified in the study population (n = 200) using polymerase chain reaction (PCR), restriction enzymes for rs352140, and Sanger sequencing for rs187084 and rs5783836. Next, statistical analyses were performed using various software to determine the association between the SNPs and T2DM. rs187084 and rs5743836 were associated with an increased risk of T2DM development. rs187084 and rs5743836 allelic frequencies were associated with a 3.2 times increased risk of T2DM development (p < 0.05). DBP was associated with T2DM (p = 0.02). rs187084 was associated with TC and HDLc; rs352140 was associated with DBP, HbA1c, and HDLc; rs5743836 was associated with waist (p < 0.05). The CGT haplotype was strongly associated with T2DM (p < 0.003). Gene-gene interaction, graphical presentation, and dendrogram showed the strong association with T2DM patients (p < 0.05). This study concluded that rs187084 and rs5743836 were strongly associated with T2DM in Saudi Arabian patients. This study provides further evidence that SNPs in the TLR9 gene play a significant role in T2DM development in a Saudi community.
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Affiliation(s)
- Zeina S. Alkudmani
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh 11433, Saudi Arabia; (Z.S.A.); (A.A.A.); (A.F.A.)
| | - Aminah Ahmad Alzailai
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh 11433, Saudi Arabia; (Z.S.A.); (A.A.A.); (A.F.A.)
| | - Khaled H. Aburisheh
- University Diabetes Center, King Saud University Medical City, King Saud University, Riyadh 11472, Saudi Arabia;
| | - Amal F. Alshammary
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh 11433, Saudi Arabia; (Z.S.A.); (A.A.A.); (A.F.A.)
| | - Imran Ali Khan
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh 11433, Saudi Arabia; (Z.S.A.); (A.A.A.); (A.F.A.)
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Kong C, Guo Z, Liu F, Tang N, Wang M, Yang D, Li C, Yang Z, Ma Y, Wang P, Tang Q. Triad3A-Mediated K48-Linked ubiquitination and degradation of TLR9 impairs mitochondrial bioenergetics and exacerbates diabetic cardiomyopathy. J Adv Res 2023:S2090-1232(23)00231-X. [PMID: 37625569 DOI: 10.1016/j.jare.2023.08.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 08/02/2023] [Accepted: 08/21/2023] [Indexed: 08/27/2023] Open
Abstract
INTRODUCTION Targeted protein degradation represents a promising therapeutic approach, while diabetic cardiomyopathy (DCM) arises as a consequence of aberrant insulin secretion and impaired glucose and lipid metabolism in the heart.. OBJECTIVES Considering that the Toll-like receptor 9 (TLR9) signaling pathway plays a pivotal role in regulating energy metabolism, safeguarding cardiomyocytes, and influencing glucose uptake, the primary objective of this study was to investigate the impact of TLR9 on diabetic cardiomyopathy (DCM) and elucidate its underlying mechanism. METHODS Mouse model of DCM was established using intraperitoneal injection of STZ, and mice were transfected with adeno-associated virus serotype 9-TLR9 (AAV9-TLR9) to assess the role of TLR9 in DCM. To explore the mechanism of TLR9 in regulating DCM disease progression, we conducted interactome analysis and employed multiple molecular approaches. RESULTS Our study revealed a significant correlation between TLR9 expression and mouse DCM. TLR9 overexpression markedly mitigated cardiac dysfunction, myocardial fibrosis, oxidative stress, and apoptosis in DCM, while inflammation levels remained relatively unaffected. Mechanistically, TLR9 overexpression positively modulated mitochondrial bioenergetics and activated the AMPK-PGC1a signaling pathway. Furthermore, we identified Triad3A as an interacting protein that facilitated TLR9's proteasomal degradation through K48-linked ubiquitination. Inhibiting Triad3A expression improved cardiac function and pathological changes in DCM by enhancing TLR9 activity. CONCLUSIONS The findings of this study highlight the critical role of TLR9 in maintaining cardiac function and mitigating pathological alterations in diabetic cardiomyopathy. Triad3A-mediated regulation of TLR9 expression and function has significant implications for understanding the pathogenesis of DCM. Targeting TLR9 and its interactions with Triad3A may hold promise for the development of novel therapeutic strategies for diabetic cardiomyopathy. Further research is warranted to fully explore the therapeutic potential of TLR9 modulation in the context of cardiovascular diseases.
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Affiliation(s)
- Chunyan Kong
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, PR China
| | - Zhen Guo
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, PR China
| | - Fangyuan Liu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, PR China
| | - Nan Tang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, PR China
| | - Mingyu Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, PR China
| | - Dan Yang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, PR China
| | - Chenfei Li
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, PR China
| | - Zheng Yang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, PR China
| | - Yulan Ma
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, PR China
| | - Pan Wang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, PR China
| | - Qizhu Tang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, PR China; Hubei Key Laboratory of Metabolic and Chronic Diseases, Wuhan, PR China.
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Wang Y, Xia Y, Chen Y, Xu L, Sun X, Li J, Huang G, Li X, Xie Z, Zhou Z. Association analysis between the TLR9 gene polymorphism rs352140 and type 1 diabetes. Front Endocrinol (Lausanne) 2023; 14:1030736. [PMID: 37139337 PMCID: PMC10150994 DOI: 10.3389/fendo.2023.1030736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 03/24/2023] [Indexed: 05/05/2023] Open
Abstract
Background To a great extent, genetic factors contribute to the susceptibility to type 1 diabetes (T1D) development, and by triggering immune imbalance, Toll-like receptor (TLR) 9 is involved in the development of T1D. However, there is a lack of evidence supporting a genetic association between polymorphisms in the TLR9 gene and T1D. Methods In total, 1513 individuals, including T1D patients (n=738) and healthy control individuals (n=775), from the Han Chinese population were recruited for an association analysis of the rs352140 polymorphism of the TLR9 gene and T1D. rs352140 was genotyped by MassARRAY. The allele and genotype distributions of rs352140 in the T1D and healthy groups and those in different T1D subgroups were analyzed by the chi-squared test and binary logistic regression model. The chi-square test and Kruskal-Wallis H test were performed to explore the association between genotype and phenotype in T1D patients. Results The allele and genotype distributions of rs352140 were significantly different in T1D patients and healthy control individuals (p=0.019, p=0.035). Specifically, the T allele and TT genotype of rs352140 conferred a higher risk of T1D (OR=1.194, 95% CI=1.029-1.385, p=0.019, OR=1.535, 95% CI=1.108-2.126, p=0.010). The allele and genotype distributions of rs352140 were not significantly different between childhood-onset and adult-onset T1D and between T1D with a single islet autoantibody and T1D with multiple islet autoantibodies (p=0.603, p=0.743). rs352140 was associated with T1D susceptibility according to the recessive and additive models (p=0.015, p=0.019) but was not associated with T1D susceptibility in the dominant and overdominant models (p=0.117, p=0.928). Moreover, genotype-phenotype association analysis showed that the TT genotype of rs352140 was associated with higher fasting C-peptide levels (p=0.017). Conclusion In the Han Chinese population, the TLR9 polymorphism rs352140 is associated with T1D and is a risk factor for susceptibility to T1D.
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Xiao F, Rui K, Shi X, Wu H, Cai X, Lui KO, Lu Q, Ballestar E, Tian J, Zou H, Lu L. Epigenetic regulation of B cells and its role in autoimmune pathogenesis. Cell Mol Immunol 2022; 19:1215-34. [PMID: 36220996 DOI: 10.1038/s41423-022-00933-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 09/19/2022] [Indexed: 11/05/2022] Open
Abstract
B cells play a pivotal role in the pathogenesis of autoimmune diseases. Although previous studies have shown many genetic polymorphisms associated with B-cell activation in patients with various autoimmune disorders, progress in epigenetic research has revealed new mechanisms leading to B-cell hyperactivation. Epigenetic mechanisms, including those involving histone modifications, DNA methylation, and noncoding RNAs, regulate B-cell responses, and their dysregulation can contribute to the pathogenesis of autoimmune diseases. Patients with autoimmune diseases show epigenetic alterations that lead to the initiation and perpetuation of autoimmune inflammation. Moreover, many clinical and animal model studies have shown the promising potential of epigenetic therapies for patients. In this review, we present an up-to-date overview of epigenetic mechanisms with a focus on their roles in regulating functional B-cell subsets. Furthermore, we discuss epigenetic dysregulation in B cells and highlight its contribution to the development of autoimmune diseases. Based on clinical and preclinical evidence, we discuss novel epigenetic biomarkers and therapies for patients with autoimmune disorders.
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Abstract
The innate immune system is a primary protective line in our body. It confers its protection through different pattern recognition receptors (PRRs), especially toll like receptors (TLRs). Toll like receptor 9 (TLR9) is an intracellular TLR, expressed in different immunological and non-immunological cells. Release of cellular components, such as proteins, nucleotides, and DNA confers a beneficial inflammatory response and maintains homeostasis for removing cellular debris during normal physiological conditions. However, during pathological cellular damage and stress signals, engagement between mtDNA and TLR9 acts as an alarm for starting inflammatory and autoimmune disorders. The controversial role of TLR9 in different diseases baffled scientists if it has a protective or deleterious effect after activation during insults. Targeting the immune system, especially the TLR9 needs further investigation to provide a therapeutic strategy to control inflammation and autoimmune disorders.
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Affiliation(s)
- Mona M Saber
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Giza, Egypt.
| | - Nada Monir
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ahram Canadian University, Giza, Egypt
| | - Azza S Awad
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ahram Canadian University, Giza, Egypt
| | - Marwa E Elsherbiny
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ahram Canadian University, Giza, Egypt
| | - Hala F Zaki
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Giza, Egypt
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Ding JT, Yang KP, Lin KL, Cao YK, Zou F. Mechanisms and therapeutic strategies of immune checkpoint molecules and regulators in type 1 diabetes. Front Endocrinol (Lausanne) 2022; 13:1090842. [PMID: 36704045 PMCID: PMC9871554 DOI: 10.3389/fendo.2022.1090842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 12/22/2022] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Considered a significant risk to health and survival, type 1 diabetes (T1D) is a heterogeneous autoimmune disease characterized by hyperglycemia caused by an absolute deficiency of insulin, which is mainly due to the immune-mediated destruction of pancreatic beta cells. SCOPE OF REVIEW In recent years, the role of immune checkpoints in the treatment of cancer has been increasingly recognized, but unfortunately, little attention has been paid to the significant role they play both in the development of secondary diabetes with immune checkpoint inhibitors and the treatment of T1D, such as cytotoxic T-lymphocyte antigen 4(CTLA-4), programmed cell death protein-1(PD-1), lymphocyte activation gene-3(LAG-3), programmed death ligand-1(PD-L1), and T-cell immunoglobulin mucin protein-3(TIM-3). Here, this review summarizes recent research on the role and mechanisms of diverse immune checkpoint molecules in mediating the development of T1D and their potential and theoretical basis for the prevention and treatment of diabetes. MAJOR CONCLUSIONS Immune checkpoint inhibitors related diabetes, similar to T1D, are severe endocrine toxicity induced with immune checkpoint inhibitors. Interestingly, numerous treatment measures show excellent efficacy for T1D via regulating diverse immune checkpoint molecules, including co-inhibitory and co-stimulatory molecules. Thus, targeting immune checkpoint molecules may exhibit potential for T1D treatment and improve clinical outcomes.
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Affiliation(s)
- Jia-Tong Ding
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Nanchang University, Nanchang, China
- The Second Clinical Medicine School, Nanchang University, Nanchang, China
| | - Kang-Ping Yang
- The Second Clinical Medicine School, Nanchang University, Nanchang, China
| | - Kong-Lan Lin
- The Second Clinical Medicine School, Nanchang University, Nanchang, China
| | - Yu-Ke Cao
- School of Ophthalmology & Optometry, Nanchang University, Nanchang, China
| | - Fang Zou
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital of Nanchang University, Nanchang, China
- *Correspondence: Fang Zou,
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Luo Z, Lundin S, Mejia-Cordova M, Hassani I, Blixt M, Hjelmqvist D, Lau J, Espes D, Carlsson PO, Sandler S, Singh K. Interleukin-35 Prevents Development of Autoimmune Diabetes Possibly by Maintaining the Phenotype of Regulatory B Cells. Int J Mol Sci 2021; 22:12988. [PMID: 34884797 DOI: 10.3390/ijms222312988] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 11/26/2021] [Accepted: 11/29/2021] [Indexed: 01/12/2023] Open
Abstract
The anti-inflammatory role of regulatory B cells (Breg cells) has been associated with IL-35 based on studies of experimental autoimmune uveitis and encephalitis. The role of Breg cells and IL-35+ Breg cells for type 1 diabetes (T1D) remains to be investigated. We studied PBMCs from T1D subjects and healthy controls (HC) and found lowered proportions of Breg cells and IL-35+ Breg cells in T1D. To elucidate the role of Breg cells, the lymphoid organs of two mouse models of T1D were examined. Lower proportions of Breg cells and IL-35+ Breg cells were found in the animal models of T1D compared with control mice. In addition, the systemic administration of recombinant mouse IL-35 prevented hyperglycemia after multiple low dose streptozotocin (MLDSTZ) injections and increased the proportions of Breg cells and IL-35+ Breg cells. A higher proportion of IFN-γ+ cells among Breg cells were found in the PBMCs of the T1D subjects. In the MLDSTZ mice, IL-35 administration decreased the proportions of IFN-γ+ cells among the Breg cells. Our data illustrate that Breg cells may play an important role in the development of T1D and that IL-35 treatment prevents the development of hyperglycemia by maintaining the phenotype of the Breg cells under an experimental T1D condition.
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Ding F, Luo X, Tu Y, Duan X, Liu J, Jia L, Zheng P. Alpk1 Sensitizes Pancreatic Beta Cells to Cytokine-Induced Apoptosis via Upregulating TNF-α Signaling Pathway. Front Immunol 2021; 12:705751. [PMID: 34621265 PMCID: PMC8490819 DOI: 10.3389/fimmu.2021.705751] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 09/06/2021] [Indexed: 11/13/2022] Open
Abstract
Pancreatic beta cell failure is the hallmark of type 1 diabetes (T1D). Recent studies have suggested that pathogen recognizing receptors (PRRs) are involved in the survival, proliferation and function of pancreatic beta cells. So far, little is known about the role of alpha-protein kinase 1 (ALPK1), a newly identified cytosolic PRR specific for ADP-β-D-manno-heptose (ADP-heptose), in beta cell survival. In current study we aimed to fill the knowledge gap by investigating the role of Alpk1 in the apoptosis of MIN6 cells, a murine pancreatic beta cell line. We found that the expression of Alpk1 was significantly elevated in MIN6 cells exposed to pro-inflammatory cytokines, but not to streptozotocin, low-dose or high-dose glucose. Activation of Alpk1 by ADP heptose alone was insufficient to induce beta cell apoptosis. However, it significantly exacerbated cytokine-induced apoptosis in MIN6 cells. Mechanistic investigations showed that Alpk1 activation was potent to further induce the expression of tumor necrosis factor (TNF)-α and Fas after cytokine stimulation, possibly due to enhanced activation of the TIFA/TAK1/NF-κB signaling axis. Treatment of GLP-1 receptor agonist decreased the expression of TNF-α and Fas and improved the survival of beta cells exposed to pro-inflammatory cytokines and ADP heptose. In summary, our data suggest that Alpk1 sensitizes beta cells to cytokine-induced apoptosis by potentiating TNF-α signaling pathway, which may provide novel insight into beta cell failure and T1D development.
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Affiliation(s)
- Fei Ding
- Department of Endocrinology, Shenzhen People's Hospital, The Second Clinical Medical College of Jinan University, The First Affiliated Hospital of Southern University of Science and Technology, Shenzhen, China
| | - Xi Luo
- Department of Endocrinology, Shenzhen People's Hospital, The Second Clinical Medical College of Jinan University, The First Affiliated Hospital of Southern University of Science and Technology, Shenzhen, China
| | - Yiting Tu
- Department of Neurology, Shenzhen Samii International Medical Center (The Fourth People's Hospital of Shenzhen), Shenzhen, China
| | - Xianlan Duan
- Department of Endocrinology, Shenzhen People's Hospital, The Second Clinical Medical College of Jinan University, The First Affiliated Hospital of Southern University of Science and Technology, Shenzhen, China
| | - Jia Liu
- School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Lijing Jia
- Department of Endocrinology, Shenzhen People's Hospital, The Second Clinical Medical College of Jinan University, The First Affiliated Hospital of Southern University of Science and Technology, Shenzhen, China
| | - Peilin Zheng
- Department of Endocrinology, Shenzhen People's Hospital, The Second Clinical Medical College of Jinan University, The First Affiliated Hospital of Southern University of Science and Technology, Shenzhen, China
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