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Zhang X, Zhang L, Wen Y, Zhang M, Liu S, Xiao H. Vitamin D Ameliorates Podocyte Injury by Enhancing Autophagy Activity in Diabetic Kidney Disease. Kidney Blood Press Res 2023; 48:314-325. [PMID: 37054686 PMCID: PMC10308546 DOI: 10.1159/000530403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 03/20/2023] [Indexed: 04/15/2023] Open
Abstract
INTRODUCTION Restoration of podocyte autophagy is considered as a feasible strategy for the treatment of diabetic kidney disease (DKD). This study aimed at investigating the protective effect and potential mechanism of vitamin D on podocyte injury of DKD. METHODS Type 2 diabetic db/db mice received intraperitoneal injections of vitamin D analog paricalcitol 400 ng/kg per day for 16 weeks. Immortalized mouse podocytes were cultured in high glucose (HG) medium with active vitamin D3 calcitriol or autophagy inhibitor 3-methyladenine. Renal function and urine albumin creatinine ratio were assessed at week 24. HE, PAS staining, and electron microscopy were used to evaluate renal histopathology and morphological changes. Immunohistochemistry, immunofluorescence, and Western blot were used to evaluate protein expression of nephrin and podocin in kidney tissue and podocytes. The expression of autophagy-related proteins (LC3, Beclin-1, Vps34) and apoptosis-related proteins (cleaved caspase-3, Bax) was determined by Western blotting. Podocyte apoptosis was further evaluated by using flow cytometer. RESULTS Albuminuria in a db/db mouse model was markedly attenuated after treatment with paricalcitol. This was accompanied by alleviation of mesangial matrix expansion and podocyte injury. Besides, the impaired autophagy in podocytes under diabetic conditions was also markedly enhanced after paricalcitol or calcitriol treatment, accompanied by restored decreased podocyte slit diaphragm proteins podocin and nephrin. Furthermore, the protective effect of calcitriol against HG-induced podocyte apoptosis could be abated by autophagy inhibitor 3-methyladenine. CONCLUSION Vitamin D ameliorates podocyte injury of DKD by enhancing podocyte autophagy activity, which may become a potential candidate autophagy activator for the therapeutic interventions for DKD.
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Affiliation(s)
- Xiaoyi Zhang
- Department of Nephrology, Binhaiwan Central Hospital of Dongguan, Dongguan, China
| | - Li Zhang
- Department of Nephrology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China,
| | - Yingzhen Wen
- Department of Endocrinology, The Third People's Hospital of Huizhou, Huizhou, China
| | - Mengxian Zhang
- Department of Nephrology, Binhaiwan Central Hospital of Dongguan, Dongguan, China
| | - Shuangxin Liu
- Department of Nephrology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Houqin Xiao
- Department of Nephrology, Binhaiwan Central Hospital of Dongguan, Dongguan, China
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Liao TH, Wu HC, Liao MT, Hu WC, Tsai KW, Lin CC, Lu KC. The Perspective of Vitamin D on suPAR-Related AKI in COVID-19. Int J Mol Sci 2022; 23:ijms231810725. [PMID: 36142634 PMCID: PMC9500944 DOI: 10.3390/ijms231810725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 09/08/2022] [Accepted: 09/13/2022] [Indexed: 01/08/2023] Open
Abstract
The coronavirus disease 2019 (COVID-19) pandemic has claimed the lives of millions of people around the world. Severe vitamin D deficiency can increase the risk of death in people with COVID-19. There is growing evidence that acute kidney injury (AKI) is common in COVID-19 patients and is associated with poorer clinical outcomes. The kidney effects of SARS-CoV-2 are directly mediated by angiotensin 2-converting enzyme (ACE2) receptors. AKI is also caused by indirect causes such as the hypercoagulable state and microvascular thrombosis. The increased release of soluble urokinase-type plasminogen activator receptor (suPAR) from immature myeloid cells reduces plasminogen activation by the competitive inhibition of urokinase-type plasminogen activator, which results in low plasmin levels and a fibrinolytic state in COVID-19. Frequent hypercoagulability in critically ill patients with COVID-19 may exacerbate the severity of thrombosis. Versican expression in proximal tubular cells leads to the proliferation of interstitial fibroblasts through the C3a and suPAR pathways. Vitamin D attenuates the local expression of podocyte uPAR and decreases elevated circulating suPAR levels caused by systemic inflammation. This decrease preserves the function and structure of the glomerular barrier, thereby maintaining renal function. The attenuated hyperinflammatory state reduces complement activation, resulting in lower serum C3a levels. Vitamin D can also protect against COVID-19 by modulating innate and adaptive immunity, increasing ACE2 expression, and inhibiting the renin–angiotensin–aldosterone system. We hypothesized that by reducing suPAR levels, appropriate vitamin D supplementation could prevent the progression and reduce the severity of AKI in COVID-19 patients, although the data available require further elucidation.
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Affiliation(s)
- Tzu-Hsien Liao
- Department of Chinese Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 231, Taiwan
| | - Hsien-Chang Wu
- Department of Chinese Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 231, Taiwan
- School of Post-Baccalaureate Chinese Medicine, Tzu Chi University, Hualien 970, Taiwan
| | - Min-Tser Liao
- Department of Pediatrics, Taoyuan Armed Forces General Hospital Hsinchu Branch, Hsinchu City 300, Taiwan
- Department of Pediatrics, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan
| | - Wan-Chung Hu
- Department of Clinical Pathology and Medical Research, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 231, Taiwan
| | - Kuo-Wang Tsai
- Department of Research, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 231, Taiwan
| | - Ching-Chieh Lin
- Department of Chest Medicine, Taoyuan Armed Forces General Hospital Hsinchu Branch, Hsinchu City 300, Taiwan
| | - Kuo-Cheng Lu
- Division of Nephrology, Department of Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei City 231, Taiwan
- Division of Nephrology, Department of Medicine, Fu-Jen Catholic University Hospital, School of Medicine, Fu-Jen Catholic University, New Taipei City 242, Taiwan
- Correspondence:
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Pierce JL, Perrien DS. Do Interactions of Vitamin D 3 and BMP Signaling Hold Implications in the Pathogenesis of Fibrodysplasia Ossificans Progressiva? Curr Osteoporos Rep 2021; 19:358-367. [PMID: 33851285 PMCID: PMC8515998 DOI: 10.1007/s11914-021-00673-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/16/2021] [Indexed: 11/24/2022]
Abstract
PURPOSE OF REVIEW Fibrodysplasia ossificans progressiva (FOP) is a debilitating rare disease known for episodic endochondral heterotopic ossification (HO) caused by gain-of-function mutations in ACVR1/ALK2. However, disease severity varies among patients with identical mutations suggesting disease-modifying factors, including diet, may have therapeutic implications. The roles of vitamin D3 in calcium metabolism and chondrogenesis are known, but its effects on BMP signaling and chondrogenesis are less studied. This review attempts to assess the possibility of vitamin D's effects in FOP by exploring relevant intersections of VD3 with mechanisms of FOP flares. RECENT FINDINGS In vitro and in vivo studies suggest vitamin D suppresses inflammation, while clinical studies suggest that vitamin D3 protects against arteriosclerosis and inversely correlates with non-genetic intramuscular HO. However, the enhancement of chondrogenesis, BMP signaling, and possibly Activin A expression by vitamin D may be more relevant in FOP. There appears to be little potential for vitamin D to reduce HO in FOP, but testing the potential for excess vitamin D to promote HO may be warranted.
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Affiliation(s)
- Jessica L Pierce
- Division of Endocrinology, Metabolism, and Lipids, Department of Medicine, Emory University School of Medicine, 101 Woodruff Circle, WMRB 1027, Atlanta, GA, 30232, USA
| | - Daniel S Perrien
- Division of Endocrinology, Metabolism, and Lipids, Department of Medicine, Emory University School of Medicine, 101 Woodruff Circle, WMRB 1027, Atlanta, GA, 30232, USA.
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Lee JM, Ko Y, Lee CH, Jeon N, Lee KH, Oh J, Kronbichler A, Saleem MA, Lim BJ, Shin JI. The Effect of Interleukin-4 and Dexamethasone on RNA-Seq-Based Transcriptomic Profiling of Human Podocytes: A Potential Role in Minimal Change Nephrotic Syndrome. J Clin Med 2021; 10:jcm10030496. [PMID: 33535372 PMCID: PMC7866993 DOI: 10.3390/jcm10030496] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 01/18/2021] [Accepted: 01/20/2021] [Indexed: 01/19/2023] Open
Abstract
Interleukin-4 (IL-4) expression is implicated in the pathogenesis of nephrotic syndrome (NS). This study aimed to investigate the changes in the transcriptomes of human podocytes induced by IL-4 treatment and to analyze whether these changes could be affected by simultaneous steroid treatment. Three groups of human podocytes were treated with control, IL-4, and IL-4 plus dexamethasone (DEX), respectively. We performed whole-transcriptome sequencing to identify differentially expressed genes (DEGs) between the groups. We investigated relevant biological pathways using Gene Ontology (GO) enrichment analyses. We also attempted to compare and validate the DEGs with the genes listed in PodNet, a literature-based database on mouse podocyte genes. A total of 176 genes were differentially expressed among the three groups. GO analyses showed that pathways related to cytoskeleton organization and cell signaling were significantly enriched. Among them, 24 genes were listed in PodNet, and 12 of them were previously reported to be associated with IL-4-induced changes in human podocytes. Of the 12 genes, the expression levels of BMP4, RARB, and PLCE1 were reversed when podocytes were simultaneously treated with DEX. In conclusion, this study explored changes in the transcriptome profiles of human podocytes treated with IL-4. Few genes were reported in previous studies and were previously validated in experiments with human podocytes. We speculate that IL-4 may exert pathogenic effects on the transcriptome of human podocytes, and a few genes may be involved in the pathogenesis.
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Affiliation(s)
- Jiwon M. Lee
- Department of Pediatrics, Chungnam National University Hospital and College of Medicine, Daejeon 35015, Korea;
| | - Younhee Ko
- Division of Biomedical Engineering, Hankuk University of Foreign Studies, Gyeonggi-do 17035, Korea;
| | - Chul Ho Lee
- Department of Pediatrics, Yonsei University College of Medicine, Seoul 03722, Korea; (C.H.L.); (K.H.L.)
- Division of Clinical Genetics, Severance Children’s Hospital, Seoul 03722, Korea
| | - Nara Jeon
- Department of Pathology, Yonsei University College of Medicine, Seoul 03722, Korea;
| | - Keum Hwa Lee
- Department of Pediatrics, Yonsei University College of Medicine, Seoul 03722, Korea; (C.H.L.); (K.H.L.)
| | - Jun Oh
- Department of Pediatrics, University Hamburg-Eppendorf, 20246 Hamburg, Germany;
| | - Andreas Kronbichler
- Department of Internal Medicine IV (Nephrology and Hypertension), Medical University Innsbruck, 6020 Innsbruck, Austria;
| | - Moin A. Saleem
- Children’s and Renal Unit and Bristol Renal, University of Bristol, Bristol BS2 8BJ, UK;
| | - Beom Jin Lim
- Department of Pathology, Yonsei University College of Medicine, Seoul 03722, Korea;
- Correspondence: (B.J.L.); (J.I.S.)
| | - Jae Il Shin
- Department of Pediatrics, Yonsei University College of Medicine, Seoul 03722, Korea; (C.H.L.); (K.H.L.)
- Division of Pediatric Nephrology, Severance Children’s Hospital, Seoul 03722, Korea
- Institute of Kidney Disease Research, Yonsei University College of Medicine, Seoul 03722, Korea
- Correspondence: (B.J.L.); (J.I.S.)
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Matsuzaki E, Minakami M, Matsumoto N, Anan H. Dental regenerative therapy targeting sphingosine-1-phosphate (S1P) signaling pathway in endodontics. JAPANESE DENTAL SCIENCE REVIEW 2020; 56:127-134. [PMID: 33088365 PMCID: PMC7567953 DOI: 10.1016/j.jdsr.2020.09.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 08/02/2020] [Accepted: 09/18/2020] [Indexed: 12/31/2022] Open
Abstract
The establishment of regenerative therapy in endodontics targeting the dentin-pulp complex, cementum, periodontal ligament tissue, and alveolar bone will provide valuable information to preserve teeth. It is well known that the application of stem cells such as induced pluripotent stem cells, embryonic stem cells, and somatic stem cells is effective in regenerative medicine. There are many somatic stem cells in teeth and periodontal tissues including dental pulp stem cells (DPSCs), stem cells from the apical papilla, and periodontal ligament stem cells. Particularly, several studies have reported the regeneration of clinical pulp tissue and alveolar bone by DPSCs transplantation. However, further scientific issues for practical implementation remain to be addressed. Sphingosine-1-phosphate (S1P) acts as a bioactive signaling molecule that has multiple biological functions including cellular differentiation, and has been shown to be responsible for bone resorption and formation. Here we discuss a strategy for bone regeneration and a possibility for regenerative endodontics targeting S1P signaling pathway as one of approaches for induction of regeneration by improving the regenerative capacity of endogenous cells. SCIENTIFIC FIELD OF DENTAL SCIENCE Endodontology.
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Affiliation(s)
- Etsuko Matsuzaki
- Section of Operative Dentistry and Endodontology, Department of Odontology, Fukuoka Dental College, 2-15-1 Tamura, Sawara-ku, Fukuoka 814-0193, Japan
- Oral Medicine Research Center, Fukuoka Dental College, Fukuoka, Japan
| | - Masahiko Minakami
- Section of Operative Dentistry and Endodontology, Department of Odontology, Fukuoka Dental College, 2-15-1 Tamura, Sawara-ku, Fukuoka 814-0193, Japan
| | - Noriyoshi Matsumoto
- Section of Operative Dentistry and Endodontology, Department of Odontology, Fukuoka Dental College, 2-15-1 Tamura, Sawara-ku, Fukuoka 814-0193, Japan
| | - Hisashi Anan
- Section of Operative Dentistry and Endodontology, Department of Odontology, Fukuoka Dental College, 2-15-1 Tamura, Sawara-ku, Fukuoka 814-0193, Japan
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Jiang L, Cui H, Ding J, Yang A, Zhang Y. Puromycin aminonucleoside-induced podocyte injury is ameliorated by the Smad3 inhibitor SIS3. FEBS Open Bio 2020; 10:1601-1611. [PMID: 32583562 PMCID: PMC7396432 DOI: 10.1002/2211-5463.12916] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 04/29/2020] [Accepted: 06/19/2020] [Indexed: 11/05/2022] Open
Abstract
Smad3 signaling and transgelin expression are often activated during puromycin aminonucleoside (PAN)‐induced podocyte injury. Here, we investigated whether the Smad3 inhibitor SIS3 can ameliorate damage to injured podocytes. A model of PAN‐induced podocyte injury was constructed using the MPC5 cell line. The effects of SIS3 on the expression of the podocyte cytoskeletal proteins transgelin, p15INK4B, phosphor‐smad3, phosphor‐JAK/stat3, the apoptotic marker cleaved caspase 3, and c‐myc were investigated using western blot. The distribution of F‐actin in PAN‐induced podocyte injury was observed under an immunofluorescence microscope. PAN‐induced podocyte injury altered the distribution of F‐actin and transgelin, and colocalization of these two proteins was observed. Transgelin expression and Smad3 phosphorylation were increased in the MPC5 cell line with prolonged PAN treatment. In addition, c‐myc expression, p15INK4B, and JAK phosphorylation were all increased after treatment with PAN. Treatment with the Smad3 inhibitor SIS3 reversed these phenomena and protected against PAN‐induced podocyte injury. Moreover, stimulating podocytes directly with TGFβ‐1 also led to enhanced expression of transgelin or phosphor‐JAK/stat3, and this could be inhibited by SIS3. In conclusion, transgelin expression was induced through the Smad3 signaling pathway during PAN‐induced podocyte injury, and the resulting abnormal distribution of F‐actin and the enhanced expression of transgelin could be reversed by blockade of this pathway.
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Affiliation(s)
- Lina Jiang
- Pediatric Department, Beijing Friendship Hospital, Capital University of Medical Sciences, Beijing, China
| | - Hong Cui
- Pediatric Department, Beijing Friendship Hospital, Capital University of Medical Sciences, Beijing, China
| | - Jie Ding
- Pediatric Department, Peking University First Hospital, Beijing, China
| | - Aijun Yang
- Pediatric Department, Beijing Friendship Hospital, Capital University of Medical Sciences, Beijing, China
| | - Yingchao Zhang
- Pediatric Department, Beijing Friendship Hospital, Capital University of Medical Sciences, Beijing, China
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Trohatou O, Tsilibary EF, Charonis A, Iatrou C, Drossopoulou G. Vitamin D3 ameliorates podocyte injury through the nephrin signalling pathway. J Cell Mol Med 2017; 21:2599-2609. [PMID: 28664547 PMCID: PMC5618699 DOI: 10.1111/jcmm.13180] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 02/24/2017] [Indexed: 12/19/2022] Open
Abstract
Renal podocytes form the main filtration barrier possessing unique phenotype maintained by proteins including podocalyxin and nephrin, which are modulated in pathological conditions. In diabetic nephropathy (DN), podocytes become structurally and functionally compromised. Nephrin, a structural backbone protein of the slit diaphragm, acts as regulator of podocyte intracellular signalling with renoprotective role. Vitamin D3 through its receptor, VDR, provides renal protection in DN but limited data exist about its effect on podocytes. In this study, we used isolated rat glomeruli to assess podocalyxin and nephrin expression after treatment with the 1,25‐dihydroxyvitamin D3 analogue paricalcitol in the presence of normal and diabetic glucose levels. The role of 1,25‐dihydroxyvitamin D3 (calcitriol) and its analogue, paricalcitol, on podocyte morphology and survival was also investigated in the streptozotocin (STZ)‐diabetic animal model. In our ex vivo model, glomeruli exhibited high glucose‐mediated down‐regulation of podocalyxin, and nephrin, while paricalcitol reversed the high glucose‐induced decrease of nephrin and podocalyxin expression. Paricalcitol treatment enhanced VDR expression and promoted VDR and RXR co‐localization in the nucleus. Our data also indicated that hyperglycaemia impaired survival of cultured glomeruli and suggested that the implemented nephrin down‐regulation was reversed by paricalcitol treatment, initiating Akt signal transduction which may be involved in glomerular survival. Our findings were further verified in vivo, as in the STZ‐diabetic animal model, calcitriol and paricalcitol treatment resulted in significant amelioration of hyperglycaemia and restoration of nephrin signalling, suggesting that calcitriol and paricalcitol may provide molecular bases for protection against loss of the permselective renal barrier in DN.
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Affiliation(s)
- Ourania Trohatou
- Institute of Biosciences and Applications, NCSR 'Demokritos', Athens, Greece
| | | | - Aristidis Charonis
- Center for Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation Academy of Athens (BRFAA), Athens, Greece
| | - Christos Iatrou
- Center for Nephrology, G. Papadakis General Hospital of Nikea-Pireaus, Athens, Greece
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Wöbke TK, Sorg BL, Steinhilber D. Vitamin D in inflammatory diseases. Front Physiol 2014; 5:244. [PMID: 25071589 PMCID: PMC4078458 DOI: 10.3389/fphys.2014.00244] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 06/12/2014] [Indexed: 02/06/2023] Open
Abstract
Changes in vitamin D serum levels have been associated with inflammatory diseases, such as inflammatory bowel disease (IBD), rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis (MS), atherosclerosis, or asthma. Genome- and transcriptome-wide studies indicate that vitamin D signaling modulates many inflammatory responses on several levels. This includes (i) the regulation of the expression of genes which generate pro-inflammatory mediators, such as cyclooxygenases or 5-lipoxygenase, (ii) the interference with transcription factors, such as NF-κB, which regulate the expression of inflammatory genes and (iii) the activation of signaling cascades, such as MAP kinases which mediate inflammatory responses. Vitamin D targets various tissues and cell types, a number of which belong to the immune system, such as monocytes/macrophages, dendritic cells (DCs) as well as B- and T cells, leading to individual responses of each cell type. One hallmark of these specific vitamin D effects is the cell-type specific regulation of genes involved in the regulation of inflammatory processes and the interplay between vitamin D signaling and other signaling cascades involved in inflammation. An important task in the near future will be the elucidation of the regulatory mechanisms that are involved in the regulation of inflammatory responses by vitamin D on the molecular level by the use of techniques such as chromatin immunoprecipitation (ChIP), ChIP-seq, and FAIRE-seq.
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Affiliation(s)
- Thea K Wöbke
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt Frankfurt, Germany
| | - Bernd L Sorg
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt Frankfurt, Germany
| | - Dieter Steinhilber
- Institute of Pharmaceutical Chemistry, Goethe University Frankfurt Frankfurt, Germany
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Vitamin D and the Immune System from the Nephrologist's Viewpoint. ISRN ENDOCRINOLOGY 2014; 2014:105456. [PMID: 24587915 PMCID: PMC3920624 DOI: 10.1155/2014/105456] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 12/04/2013] [Indexed: 02/07/2023]
Abstract
Vitamin D and its analogues are widely used as treatments by clinical nephrologists, especially when treating chronic kidney disease (CKD) patients with secondary hyperparathyroidism. As CKD progresses, the ability to compensate for elevations in parathyroid hormone (PTH) and fibroblast growth factor-23 and for decreases in 1,25(OH)2D3 becomes inadequate, which results in hyperphosphatemia, abnormal bone disorders, and extra-skeletal calcification. In addition to its calciotropic effect on the regulation of calcium, phosphate, and parathyroid hormone, vitamin D has many other noncalciotropic effects, including controlling cell differentiation/proliferation and having immunomodulatory effects. There are several immune dysregulations that can be noted when renal function declines. Physicians need to know well both the classical and nonclassical functions of vitamin D. This review is an analysis from the nephrologist's viewpoint and focuses on the relationship between the vitamin D and the immune system, together with vitamin's clinical use to treat kidney diseases.
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Hirose M, Nishino T, Obata Y, Nakazawa M, Nakazawa Y, Furusu A, Abe K, Miyazaki M, Koji T, Kohno S. 22-Oxacalcitriol prevents progression of peritoneal fibrosis in a mouse model. Perit Dial Int 2012; 33:132-42. [PMID: 23032084 DOI: 10.3747/pdi.2011.00234] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
OBJECTIVE Vitamin D plays an important role in calcium homeostasis and is used to treat secondary hyperparathyroidism among dialysis patients. The biologic activity of vitamin D and its analogs is mediated by vitamin D receptor (VDR), which is distributed widely throughout the body. Recent papers have revealed that low vitamin D levels are correlated with severe fibrosis in chronic diseases, including cystic fibrosis and hepatitis. The aim of the present study was to evaluate the protective effects of vitamin D against the progression of peritoneal fibrosis. METHODS Peritoneal fibrosis was induced by injection of chlorhexidine gluconate (CG) into the peritoneal cavity of mice every other day for 3 weeks. An analog of vitamin D, 22-oxacalcitriol (OCT), was administered subcutaneously daily from initiation of the CG injections. The peritoneal tissue was excised at 3 weeks. Changes in morphology were assessed by hematoxylin and eosin staining. Expression of VDR, alpha smooth muscle actin (as a marker of myofibroblasts), type III collagen, transforming growth factor β(TGF-β), phosphorylated Smad2/3, F4/80 (as a marker of macrophages), and monocyte chemoattractant protein-1 (MCP-1) was examined by immunohistochemistry. Southwestern histochemistry was used to detect activated nuclear factor κB (NF-κB). RESULTS In the CG-injected mice, immunohistochemical analysis revealed expression of VDR in mesothelial cells, myofibroblasts, and macrophages in the thickened submesothelial zone. Treatment with OCT significantly prevented peritoneal fibrosis and reduced the accumulation of type III collagen in CG-treated mice. Among the markers of fibrosis, the numbers of myofibroblasts, cells positive for TGF-β, and cells positive for phosphorylated Smad2/3 were significantly decreased in the OCT-treated group compared with the vehicle-treated group. Furthermore, OCT suppressed inflammatory mediators of fibrosis, as shown by the reduced numbers of activated NF-κB cells, macrophages, and MCP-1-expressing cells. CONCLUSIONS Our results indicate that OCT attenuates peritoneal fibrosis, an effect accompanied by reduced numbers of myofibroblasts, infiltrating macrophages, and TGF-β-positive cells, suggesting that vitamin D has potential as a novel therapeutic agent for preventing peritoneal sclerosis.
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Affiliation(s)
- Misaki Hirose
- Second Department of Internal Medicine, Nagasaki University School of Medicine, Nagasaki, Japan
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Liu S, Shi W, Xiao H, Liang X, Deng C, Ye Z, Mei P, Wang S, Liu X, Shan Z, Liang Y, Zhang B, Wang W, Liu Y, Xu L, Xia Y, Ma J, Li Z. Receptor activator of NF-kappaB and podocytes: towards a function of a novel receptor-ligand pair in the survival response of podocyte injury. PLoS One 2012; 7:e41331. [PMID: 22848465 PMCID: PMC3405116 DOI: 10.1371/journal.pone.0041331] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Accepted: 06/26/2012] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Glomerulosclerosis correlates with reduction in podocyte number that occurs through mechanisms which include apoptosis. Podocyte injury or podocyte loss in the renal glomerulus has been proposed as the crucial mechanism in the development of glomerulosclerosis. However, the mechanism by which podocytes respond to injury is poorly understood. TNF and TNF receptor superfamilies are important in the pathogenesis of podocyte injury and apoptosis. The ligand of receptor activator of NF-kappaB (RANKL) and receptor activator of NF-kappaB (RANK) are members of the TNF and receptor superfamilies. We investigated whether RANK-RANKL is a receptor-ligand complex for podocytes responding to injury. METHODOLOGY/PRINCIPAL FINDINGS In this study, RANKL and RANK were examined in human podocyte diseases and a rat model of puromycin aminonucleoside nephrosis (PAN). Compared with controls, RANK and RANKL were increased in both human podocyte diseases and the rat PAN model; double immunofluorescence staining revealed that RANK protein expression was mainly attributed to podocytes. Immunoelectron microscopy showed that RANK was localized predominantly at the top of the foot process membrane and the cytoplasm of rat podocyte. In addition, RANK was upregulated in mouse podocytes in vitro after injury induced by puromycin aminonucleoside (PA). Knockdown of RANK expression by small interference RNA (siRNA) exacerbated podocyte apoptosis induced by PA. However, RANKL inhibited significantly the apoptosis of podocytes induced by PA. CONCLUSIONS/SIGNIFICANCE These findings suggest the increase in RANK-RANKL expression is a response to podocyte injury, and RANK-RANKL may be a novel receptor-ligand complex for the survival response during podocyte injury.
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Affiliation(s)
- Shuangxin Liu
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
- Southern Medical University, Guangzhou, Guangdong, China
| | - Wei Shi
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Houqin Xiao
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Xinling Liang
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Chunyu Deng
- Medical Research Center, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Zhiming Ye
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Ping Mei
- Department of Pathology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Suxia Wang
- Department of Pathology, Peking University First Hospital, Beijing, China
| | - Xiaoying Liu
- Medical Research Center, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Zhixin Shan
- Medical Research Center, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Yongzheng Liang
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Bin Zhang
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Wenjian Wang
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Yanhui Liu
- Department of Pathology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Lixia Xu
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Yunfeng Xia
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Jianchao Ma
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Zhilian Li
- Department of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
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Abstract
The kidney is the major, if not sole, site for the production of 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3), the biologically active form of vitamin D that can stimulate calcium reabsorption in the kidney and may provide renoprotective benefits. The biological effects of 1,25(OH)2D3 are mediated through a nuclear hormone receptor, known as the vitamin D receptor (VDR). It is well accepted that the VDR is present in the distal renal convoluted tubule cells; however, whether VDR is present in other kidney cell types is uncertain. Using a highly specific and sensitive anti-VDR antibody, we determined its distribution in the mouse kidney by immunohistochemistry. Our results show that the VDR is not only present in the distal but is also found in the proximal tubules, but at 24-fold lower levels. The VDR was also found in the macula densa of the juxtaglomerular apparatus, glomerular parietal epithelial cells, and podocytes. In contrast, the VDR is either very low or absent in interstitial fibroblasts, glomerular mesangial cells, and juxtaglomerular cells. Thus, identification of VDR in the proximal tubule, macula densa, and podocytes suggests that 1,25(OH)2D3 plays a direct role in these cells under normal conditions.
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He W, Kang YS, Dai C, Liu Y. Blockade of Wnt/β-catenin signaling by paricalcitol ameliorates proteinuria and kidney injury. J Am Soc Nephrol 2010; 22:90-103. [PMID: 21030600 DOI: 10.1681/asn.2009121236] [Citation(s) in RCA: 220] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Recent studies implicate Wnt/β-catenin signaling in podocyte dysfunction. Because vitamin D analogs can inhibit β-catenin in other tissues, we tested whether the vitamin D analog paricalcitol could ameliorate podocyte injury, proteinuria, and renal fibrosis in adriamycin (ADR) nephropathy. Compared with vehicle-treated controls, paricalcitol preserved expression of nephrin, podocin, and WT1; prevented proteinuria; and reduced glomerulosclerotic lesions induced by ADR. Paricalcitol also inhibited expression of proinflammatory cytokines, reduced renal infiltration of monocytes/macrophages, hampered activation of renal myofibroblasts, and suppressed expression of the fibrogenic TGF-β1, CTGF, fibronectin, and types I and III collagen. Selective suppression of renal Wnt4, Wnt7a, Wnt7b, and Wnt10a expression after ADR accompanied these renoprotective effects of paricalcitol. Significant upregulation of β-catenin, predominantly in podocytes and tubular epithelial cells, accompanied renal injury; paricalcitol largely abolished this induction of renal β-catenin and inhibited renal expression of Snail, a downstream effector of Wnt/β-catenin signaling. Administration of paricalcitol also ameliorated established proteinuria. In vitro, paricalcitol induced a physical interaction between the vitamin D receptor and β-catenin in podocytes, which led to suppression of β-catenin-mediated gene transcription. In summary, these findings suggest that paricalcitol prevents podocyte dysfunction, proteinuria, and kidney injury in adriamycin nephropathy by inhibiting Wnt/β-catenin signaling.
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Affiliation(s)
- Weichun He
- Department of Pathology, University of Pittsburgh School of Medicine, S-405 Biomedical Science Tower, 200 Lothrop Street, Pittsburgh, PA 15261, USA
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Zou MS, Yu J, Nie GM, He WS, Luo LM, Xu HT. 1, 25-dihydroxyvitamin D3 decreases adriamycin-induced podocyte apoptosis and loss. Int J Med Sci 2010; 7:290-9. [PMID: 20827429 PMCID: PMC2934728 DOI: 10.7150/ijms.7.290] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Accepted: 08/17/2010] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Selective proteinuria is frequently observed in glomerular diseases characterized by podocyte injury. Although, 1,25-dihydroxyvitamin D3 [1,25(OH)(2)D(3)] has potential therapeutic effects on chronic kidney diseases through decreasing podocyte loss, the mechanism underlying the beneficial effects of 1,25(OH)(2)D(3) on podocytes remains still unknown. The present study tested the hypothesis that 1,25(OH)(2)D(3) directly reduced podocyte apoptosis and loss. METHODS Sprague-Dawley (SD) rats were randomly assigned into three groups: Adriamycin (ADR) group (n=15), ADR+1,25-(OH)(2)D(3) group (n=16), and control group (n=16). Rats in ADR+1,25-(OH)(2)D(3) group were treated with 1,25(OH)(2)D(3) for 8 weeks. The number of podocytes and foot process width (FPW) were detected by transmission electron microscopy. The number of apoptotic podocytes per glomerulus and that of apoptotic nuclei and caspase-3 activity in cultured podocytes were determined by TUNEL staining. The average number of podocytes per glomerulus was quantified by immunohistochemistry. Expressions of p-Smad2/3, p-Smad1/5/8, Fas, Fas-Associated protein with Death Domain (FADD), Bax, and Bcl-2 proteins were examined by Western blot assay. RESULTS Compared with control group, proteinuria, FPW, apoptotic podocytes, caspase-3 activity, the protein expressions of p-Smad2/3, Fas, FADD, and Bax were significantly increased, podocyte density, p-Smad1/5/8 and Bcl-2 expression were decreased in ADR group. 1,25(OH)(2)D(3) significantly reduced proteinuria, FPW, caspase-3 activity, expressions of p-Smad2/3, Fas, FADD, and Bax and apoptosis of podocytes, but increased serum albumin, number of viable podocytes , p-Smad1/5/8 and Bcl-2 expression in ADR treated rats. CONCLUSION ADR-induced podocyte apoptosis was associated with the imbalance of p-Smad2/3, p-Smad1/5/8 the activity of caspase-3 and aberrant expressions of, Fas, FADD, Bax and Bcl-2. The beneficial effects of 1,25(OH)(2)D(3 )on podocytes may be attributable to inhibit podocyte apoptosis and the amelioration of podocytopenia.
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Affiliation(s)
- Min-shu Zou
- Department of Pediatrics, Wuhan General Hospital of Guangzhou Command, Wuhan, China
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Zou MS, Yu J, Zhou JH, Nie GM, Ding DS, Luo LM, Xu HT, He WS. 1,25-Dihydroxyvitamin D3 ameliorates podocytopenia in rats with adriamycin-induced nephropathy. Intern Med 2010; 49:2677-86. [PMID: 21173542 DOI: 10.2169/internalmedicine.49.4174] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVE To investigate the role of α3β1 integrin and α/β-dystroglycan in protective effects of 1,25(OH)2D3 on podocytes in rats with adriamycin-induced nephropathy. METHODS Sprague-Dawley rats were randomly divided into three groups: control group (NC), nephropathy group (NE), and nephropathy+1,25(OH)2D3 group (ND). Rats in NE and ND group were injected intravenously with adriamycin (0.1 mg/10 g body weight) to induce nephropathy, and those in ND group were then subcutaneously treated with 1,25(OH)2D3 for 8 weeks. Urinary protein level, number of urine podocytes, foot process width and glomerulosclerotic index were determined. Nephrin and podocin mRNA and protein expressions were determined by RT-PCR and western blot, respectively. Podocyte density and expressions of α3β1 integrin and α/β-dystroglycan (DG) were analyzed by immunohistochemistry and western blot, respectively. RESULTS The increase in proteinuria, podocyturia and width of foot process in NE group were ameliorated after treatment with 1,25(OH)2D3 for 8 weeks. The glomerulosclerotic index was significantly decreased in ND group when compared with NE group. The podocyte density in ND group (10.3±1.64 cells/glomerulus) was significantly higher than that in NE group (8.43±1.75 cells/glomerulus) (p=0.008). 1,25(OH)2D3 treatment could significantly up-regulate the mRNA and protein expressions of nephrin and podocin, and the protein expressions of α3β1 integrin and α/β-DG. CONCLUSION The expressions of nephrin, podocin, α3β1 integrin and α/β-DG were decreased in rats with nephropathy. However, 1,25(OH)2D3 treatment could significantly up-regulate the expressions of nephrin, podocin, α3β1 integrin and α/β-DG proteins which might suppress podocyte detachment and podocytopenia.
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Affiliation(s)
- Min-shu Zou
- Department of Pediatrics, Wuhan General Hospital of Guangzhou Command, and Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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