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Zhang X, Zhang D, Huo L, Zhou X, Zhang J, Li M, Su D, Sun P, Chen F, Liang X. Upregulation of α-ENaC induces pancreatic β-cell dysfunction, ER stress, and SIRT2 degradation. J Biomed Res 2024; 38:241-255. [PMID: 38769731 PMCID: PMC11144933 DOI: 10.7555/jbr.37.20230128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 11/05/2023] [Accepted: 11/11/2023] [Indexed: 05/22/2024] Open
Abstract
Islet beta cells (β-cells) produce insulin in response to high blood glucose levels, which is essential for preserving glucose homeostasis. Voltage-gated ion channels in β-cells, including Na +, K +, and Ca 2+ channels, aid in the release of insulin. The epithelial sodium channel alpha subunit (α-ENaC), a voltage-independent sodium ion channel, is also expressed in human pancreatic endocrine cells. However, there is no reported study on the function of ENaC in the β-cells. In the current study, we found that α-ENaC was expressed in human pancreatic glandule and pancreatic islet β-cells. In the pancreas of db/db mice and high-fat diet-induced mice, and in mouse islet β-cells (MIN6 cells) treated with palmitate, α-ENaC expression was increased. When α-ENaC was overexpressed in MIN6 cells, insulin content and glucose-induced insulin secretion were significantly reduced. On the other hand, palmitate injured islet β-cells and suppressed insulin synthesis and secretion, but increased α-ENaC expression in MIN6 cells. However, α-ENaC knockout ( Scnn1a -/-) in MIN6 cells attenuated β-cell disorder induced by palmitate. Furthermore, α-ENaC regulated the ubiquitylation and degradation of sirtuin 2 in β-cells. α-ENaC also modulated β-cell function in correlation with the inositol-requiring enzyme 1 alpha/X-box binding protein 1 (IRE1α/XBP1) and protein kinase RNA-like endoplasmic reticulum kinase/C/EBP homologous protein (PERK/CHOP) endoplasmic reticulum stress pathways. These results suggest that α-ENaC may play a novel role in insulin synthesis and secretion in the β-cells, and the upregulation of α-ENaC promotes islet β-cell dysfunction. In conclusion, α-ENaC may be a key regulator involved in islet β-cell damage and a potential therapeutic target for type 2 diabetes mellitus.
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Affiliation(s)
- Xue Zhang
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
- Department of Pathology, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu 210009, China
| | - Dan Zhang
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
- Department of Pathology, Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu 210009, China
| | - Lei Huo
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Xin Zhou
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Jia Zhang
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Min Li
- Department of Pathology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Dongming Su
- Department of Pathology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Peng Sun
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Fang Chen
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
| | - Xiubin Liang
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu 211166, China
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Kim H, Lee DS, An TH, Park TJ, Lee EW, Han BS, Kim WK, Lee CH, Lee SC, Oh KJ, Bae KH. GADD45β Regulates Hepatic Gluconeogenesis via Modulating the Protein Stability of FoxO1. Biomedicines 2021; 9:biomedicines9010050. [PMID: 33435535 PMCID: PMC7827134 DOI: 10.3390/biomedicines9010050] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 12/26/2020] [Accepted: 01/07/2021] [Indexed: 01/07/2023] Open
Abstract
Increased hepatic gluconeogenesis is one of the main contributors to the development of type 2 diabetes. Recently, it has been reported that growth arrest and DNA damage-inducible 45 beta (GADD45β) is induced under both fasting and high-fat diet (HFD) conditions that stimulate hepatic gluconeogenesis. Here, this study aimed to establish the molecular mechanisms underlying the novel role of GADD45β in hepatic gluconeogenesis. Both whole-body knockout (KO) mice and adenovirus-mediated knockdown (KD) mice of GADD45β exhibited decreased hepatic gluconeogenic gene expression concomitant with reduced blood glucose levels under fasting and HFD conditions, but showed a more pronounced effect in GADD45β KD mice. Further, in primary hepatocytes, GADD45β KD reduced glucose output, whereas GADD45β overexpression increased it. Mechanistically, GADD45β did not affect Akt-mediated forkhead box protein O1 (FoxO1) phosphorylation and forskolin-induced cAMP response element-binding protein (CREB) phosphorylation. Rather it increased FoxO1 transcriptional activity via enhanced protein stability of FoxO1. Further, GADD45β colocalized and physically interacted with FoxO1. Additionally, GADD45β deficiency potentiated insulin-mediated suppression of hepatic gluconeogenic genes, and it were impeded by the restoration of GADD45β expression. Our finding demonstrates GADD45β as a novel and essential regulator of hepatic gluconeogenesis. It will provide a deeper understanding of the FoxO1-mediated gluconeogenesis.
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Affiliation(s)
- Hyunmi Kim
- Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (H.K.); (D.S.L.); (T.H.A.); (T.-J.P.); (E.-W.L.); (B.S.H.); (W.K.K.); (S.C.L.)
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon 34141, Korea
| | - Da Som Lee
- Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (H.K.); (D.S.L.); (T.H.A.); (T.-J.P.); (E.-W.L.); (B.S.H.); (W.K.K.); (S.C.L.)
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon 34141, Korea
| | - Tae Hyeon An
- Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (H.K.); (D.S.L.); (T.H.A.); (T.-J.P.); (E.-W.L.); (B.S.H.); (W.K.K.); (S.C.L.)
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon 34141, Korea
| | - Tae-Jun Park
- Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (H.K.); (D.S.L.); (T.H.A.); (T.-J.P.); (E.-W.L.); (B.S.H.); (W.K.K.); (S.C.L.)
| | - Eun-Woo Lee
- Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (H.K.); (D.S.L.); (T.H.A.); (T.-J.P.); (E.-W.L.); (B.S.H.); (W.K.K.); (S.C.L.)
| | - Baek Soo Han
- Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (H.K.); (D.S.L.); (T.H.A.); (T.-J.P.); (E.-W.L.); (B.S.H.); (W.K.K.); (S.C.L.)
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon 34141, Korea
| | - Won Kon Kim
- Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (H.K.); (D.S.L.); (T.H.A.); (T.-J.P.); (E.-W.L.); (B.S.H.); (W.K.K.); (S.C.L.)
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon 34141, Korea
| | - Chul-Ho Lee
- Laboratory Animal Resource Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea;
| | - Sang Chul Lee
- Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (H.K.); (D.S.L.); (T.H.A.); (T.-J.P.); (E.-W.L.); (B.S.H.); (W.K.K.); (S.C.L.)
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon 34141, Korea
| | - Kyoung-Jin Oh
- Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (H.K.); (D.S.L.); (T.H.A.); (T.-J.P.); (E.-W.L.); (B.S.H.); (W.K.K.); (S.C.L.)
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon 34141, Korea
- Correspondence: (K.-J.O.); (K.-H.B.)
| | - Kwang-Hee Bae
- Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 34141, Korea; (H.K.); (D.S.L.); (T.H.A.); (T.-J.P.); (E.-W.L.); (B.S.H.); (W.K.K.); (S.C.L.)
- Department of Functional Genomics, KRIBB School of Bioscience, Korea University of Science and Technology (UST), Daejeon 34141, Korea
- Correspondence: (K.-J.O.); (K.-H.B.)
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Bukhari AAS, Zhang X, Li M, Zhao A, Dong H, Liang X. Cofilin participates in regulating alpha-epithelial sodium channel by interaction with 14-3-3 isoforms. J Biomed Res 2020; 34:351-360. [PMID: 32981895 PMCID: PMC7540242 DOI: 10.7555/jbr.34.20190155] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Renal epithelial sodium channel (ENaC) plays a crucial role in maintaining homeostasis and sodium absorption. While insulin participates in controlling sodium transport across the renal epithelium, the underlying molecular mechanism remain unclear. In this study, we found that insulin increased the expression and function of alpha-epithelial sodium channel (α-ENaC) as well as phosphorylation of cofilin, a family of actin-binding proteins which disassembles actin filaments, in mouse cortical collecting duct (mpkCCDc14) cells. The wild-type (WT) cofilin and its constitutively phosphorylated form (S3D), but not its constitutively non-phosphorylable form (S3A), contributed to the elevated expression on α-ENaC. Overexpression of 14-3-3ε, β, or γ increased the expression of α-ENaC and cofilin phosphorylation, which was blunted by knockdown of 14-3-3ε, β, or γ. Moreover, it was found that insulin increased the interaction between cofilin and 14-3-3 isoforms, which indicated relevance of 14-3-3 isoforms with cofilin. Furthermore, LIMK1/SSH1 pathway was involved in regulation of cofilin and α-ENaC expression by insulin. The results from this work indicate that cofilin participates in the regulation of α-ENaC by interaction with 14-3-3 isoforms.
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Affiliation(s)
| | | | | | | | | | - Xiubin Liang
- Department of Pathophysiology;Department of Nephrology, the Affiliated Sir Run Run Hospital of Nanjing Medical University, Nanjing, Jiangsu 211166, China
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Zhang X, Ge Y, Bukhari AAS, Zhu Q, Shen Y, Li M, Sun H, Su D, Liang X. Estrogen negatively regulates the renal epithelial sodium channel (ENaC) by promoting Derlin-1 expression and AMPK activation. Exp Mol Med 2019; 51:1-12. [PMID: 31113930 PMCID: PMC6529463 DOI: 10.1038/s12276-019-0253-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 01/28/2019] [Accepted: 02/07/2019] [Indexed: 12/13/2022] Open
Abstract
The main functions of the epithelial sodium channel (ENaC) in the kidney distal nephron are mediation of sodium and water balance and stabilization of blood pressure. Estrogen has important effects on sodium and water balance and on premenopausal blood pressure, but its role in the regulation of ENaC function is not fully understood. Female Sprague–Dawley rats were treated with 17β-estradiol for 6 weeks following bilateral ovariectomy. Plasma estrogen, aldosterone, creatinine, and electrolytes were analyzed, and α-ENaC and derlin-1 protein expression in the kidney was determined by immunohistochemistry and western blotting. The expression levels of α-ENaC, derlin-1, AMPK, and related molecules were also examined by western blotting and real-time PCR in cultured mouse renal collecting duct (mpkCCDc14) epithelial cells following estrogen treatment. Immunofluorescence and coimmunoprecipitation were performed to detect α-ENaC binding with derlin-1 and α-ENaC ubiquitination. The results demonstrated that the loss of estrogen elevated systolic blood pressure in ovariectomized (OVX) rats. OVX rat kidneys showed increased α-ENaC expression but decreased derlin-1 expression. In contrast, estrogen treatment decreased α-ENaC expression but increased derlin-1 expression in mpkCCDc14 cells. Moreover, estrogen induced α-ENaC ubiquitination by promoting the interaction of α-ENaC with derlin-1 and evoked phosphorylation of AMPK in mpkCCDc14 cells. Our study indicates that estrogen reduces ENaC expression and blood pressure in OVX rats through derlin-1 upregulation and AMPK activation. Estrogen treatment could prove valuable in tackling high blood pressure (hypertension) in postmenopausal women. Long-term healthy blood pressure is linked to the correct regulation of sodium and water levels in the kidneys. The renal epithelial sodium channel (ENaC) is a cellular membrane channel responsible for mediating sodium reabsorption and fluid balance. Liang and co-workers at Nanjing Medical University in Nanjing, China, conducted experiments on postmenopausal rat models, and found that loss of estrogen elevates systolic blood pressure (the pressure during heart muscle contraction), and that the rats had high levels of ENaC expression. Further investigations showed that estrogen treatment restored blood pressure to normal levels by promoting two key proteins involved in cellular membrane health and energy metabolism. This in turn reinstated normal levels of ENaC breakdown in the kidneys, limiting hypertension.
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Affiliation(s)
- Xue Zhang
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Yamei Ge
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | | | - Qian Zhu
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Yachen Shen
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Min Li
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Hui Sun
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Dongming Su
- Center of Pathology and Clinical Laboratory, Sir Run Run Hospital, Department of Pathology, Nanjing Medical University, Nanjing, Jiangsu Province, China.,State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Xiubin Liang
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, China. .,State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu Province, China.
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Fan JJ, Hsu WH, Hung HH, Zhang WJ, Lee YLA, Chen KC, Chu CY, Ko TP, Lee MT, Lin CW, Cheng CH. Reduction in MnSOD promotes the migration and invasion of squamous carcinoma cells. Int J Oncol 2019; 54:1639-1650. [PMID: 30896828 PMCID: PMC6438424 DOI: 10.3892/ijo.2019.4750] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 03/06/2019] [Indexed: 12/18/2022] Open
Abstract
Reactive oxygen species (ROS) homeostasis is maintained at a higher level in cancer cells, which promotes tumorigenesis. Oxidative stress induced by anticancer drugs may further increase ROS to promote apoptosis, but can also enhance the metastasis of cancer cells. The effects of ROS homeostasis on cancer cells remain to be fully elucidated. In the present study, the effect of a reduction in manganese superoxide dismutase (MnSOD) on the migration and invasion of A431 cells was investigated. Our previous micro‑assay data revealed that the mRNA expression of MnSOD was higher in the invasive A431‑III cell line compared with that in the parental A431 cell line (A431‑P). In the present study, high protein levels of MnSOD and H2O2 production were observed in A431‑III cells; however, catalase protein levels were significantly lower in A431‑III cells compared with those in the A431‑P cell line. The knockdown of MnSOD increased H2O2 levels, enzyme activity, the mRNA levels of matrix metalloproteinase‑1, ‑2 and ‑9, and the migratory and invasive abilities of the cells. Inducing a reduction in H2O2 using diphenyleneiodonium (DPI) and N‑acetyl‑l‑cysteine decreased the migratory abilities of the cell lines, and DPI attenuated the migratory ability that had been increased by MnSOD small interfering RNA knockdown. Luteolin (Lu) and quercetin (Qu) increased the expression of catalase and reduced H2O2 levels, but without an observed change in the protein levels of MnSOD. Taken together, these data suggest that reduced MnSOD may induce ROS imbalance in cells and promote the metastatic ability of cancer cells. Lu and Qu may attenuate these processes and may be promising potential anticancer agents.
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Affiliation(s)
- Jhen-Jia Fan
- Institute of Biochemical Sciences, National Taiwan University, Taipei 10617, Taiwan, R.O.C
| | - Wen-Hsien Hsu
- Department of Surgery, Wan‑Fang Hospital, Taipei Medical University, Taipei 11031, Taiwan, R.O.C
| | - Hao-Hsiang Hung
- Institute of Biochemical Sciences, National Taiwan University, Taipei 10617, Taiwan, R.O.C
| | - Wei-Jun Zhang
- Institute of Biochemical Sciences, National Taiwan University, Taipei 10617, Taiwan, R.O.C
| | - Yu-Lin A Lee
- Departments of Medicine and Pediatrics, Hospice and Palliative Medicine, Duke University Hospital, Durham, NC 27710, USA
| | - Ku-Chung Chen
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan, R.O.C
| | - Cheng-Ying Chu
- Center of Cancer Translational Medicine, Taipei Medical University, Taipei 11031, Taiwan, R.O.C
| | - Tzu-Ping Ko
- Institute of Biological Chemistry, Academia Sinica, Taipei 11529, Taiwan, R.O.C
| | - Ming-Ting Lee
- Institute of Biochemical Sciences, National Taiwan University, Taipei 10617, Taiwan, R.O.C
| | - Cheng-Wei Lin
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan, R.O.C
| | - Chia-Hsiung Cheng
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan, R.O.C
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FoxO1 regulates allergic asthmatic inflammation through regulating polarization of the macrophage inflammatory phenotype. Oncotarget 2017; 7:17532-46. [PMID: 27007158 PMCID: PMC4951231 DOI: 10.18632/oncotarget.8162] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 03/01/2016] [Indexed: 01/18/2023] Open
Abstract
Inflammatory monocyte and tissue macrophages influence the initiation, progression, and resolution of type 2 immune responses, and alveolar macrophages are the most prevalent immune-effector cells in the lung. While we were characterizing the M1- or M2-like macrophages in type 2 allergic inflammation, we discovered that FoxO1 is highly expressed in alternatively activated macrophages. Although several studies have been focused on the fundamental role of FoxOs in hematopoietic and immune cells, the exact role that FoxO1 plays in allergic asthmatic inflammation in activated macrophages has not been investigated. Growing evidences indicate that FoxO1 acts as an upstream regulator of IRF4 and could have a role in a specific inflammatory phenotype of macrophages. Therefore, we hypothesized that IRF4 expression regulated by FoxO1 in alveolar macrophages is required for established type 2 immune mediates allergic lung inflammation. Our data indicate that targeted deletion of FoxO1 using FoxO1-selective inhibitor AS1842856 and genetic ablation of FoxO1 in macrophages significantly decreases IRF4 and various M2 macrophage-associated genes, suggesting a mechanism that involves FoxO1-IRF4 signaling in alveolar macrophages that works to polarize macrophages toward established type 2 immune responses. In response to the challenge of DRA (dust mite, ragweed, and Aspergillus) allergens, macrophage specific FoxO1 overexpression is associated with an accentuation of asthmatic lung inflammation, whereas pharmacologic inhibition of FoxO1 by AS1842856 attenuates the development of asthmatic lung inflammation. Thus, our study identifies a role for FoxO1-IRF4 signaling in the development of alternatively activated alveolar macrophages that contribute to type 2 allergic airway inflammation.
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You H, Ge Y, Zhang J, Cao Y, Xing J, Su D, Huang Y, Li M, Qu S, Sun F, Liang X. Derlin-1 promotes ubiquitylation and degradation of the epithelial Na + channel, ENaC. J Cell Sci 2017; 130:1027-1036. [PMID: 28137758 DOI: 10.1242/jcs.198242] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 01/24/2017] [Indexed: 11/20/2022] Open
Abstract
Ubiquitylation of the epithelial Na+ channel (ENaC) plays a critical role in cellular functions, including transmembrane transport of Na+, Na+ and water balance, and blood pressure stabilization. Published studies have suggested that ENaC subunits are targets of ER-related degradation (ERAD) in yeast systems. However, the molecular mechanism underlying proteasome-mediated degradation of ENaC subunits remains to be established. Derlin-1, an E3 ligase mediator, links recognized target proteins to ubiquitin-mediated proteasomal degradation in the cytosol. In the present study, we found that derlin-1 suppressed the expression of ENaC at the protein level and that the subunit α-ENaC (also known as SCNN1A) physically interacted with derlin-1 at the membrane-anchored domains or the loop regions, and that derlin-1 initiated α-ENaC retrotranslocation. In addition, HUWE1, an endoplasmic reticulum (ER)-resident E3 ubiquitin ligase, was recruited and promoted K11-linked polyubiquitylation of α-ENaC and, hence, formation of an α-ENaC ubiquitin-mediated degradation complex. These findings suggest that derlin-1 promotes ENaC ubiquitylation and enhances ENaC ubiquitin- mediated proteasome degradation. The derlin-1 pathway therefore may represent a significant early checkpoint in the recognition and degradation of ENaC in mammalian cells.
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Affiliation(s)
- Hui You
- Renal Division, Sir Run Run Hospital, Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, 211166, China.,Department of Endocrinology and Metabolism, Shanghai Tenth People's Hospital, Tong-Ji University, Shanghai, 200072, China
| | - Yamei Ge
- Renal Division, Sir Run Run Hospital, Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, 211166, China
| | - Jian Zhang
- Renal Division, Sir Run Run Hospital, Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, 211166, China
| | - Yizhi Cao
- Renal Division, Sir Run Run Hospital, Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, 211166, China
| | - Jing Xing
- Renal Division, Sir Run Run Hospital, Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, 211166, China
| | - Dongming Su
- Center of Pathology and Clinical Laboratory, Sir Run Run Hospital, Nanjing Medical University, Nanjing, Jiangsu Province, 211166, China
| | - Yujie Huang
- Renal Division, Sir Run Run Hospital, Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, 211166, China
| | - Min Li
- Renal Division, Sir Run Run Hospital, Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, 211166, China
| | - Shen Qu
- Department of Endocrinology and Metabolism, Shanghai Tenth People's Hospital, Tong-Ji University, Shanghai, 200072, China
| | - Fei Sun
- Department of Physiology, School of Medicine, Wayne State University, Detroit, MI 48201, USA
| | - Xiubin Liang
- Renal Division, Sir Run Run Hospital, Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, 211166, China
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