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Gu Q, An Y, Xu M, Huang X, Chen X, Li X, Shan H, Zhang M. Disulfidptosis, A Novel Cell Death Pathway: Molecular Landscape and Therapeutic Implications. Aging Dis 2024:AD.2024.0083. [PMID: 38739940 DOI: 10.14336/ad.2024.0083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 05/02/2024] [Indexed: 05/16/2024] Open
Abstract
Programmed cell death is pivotal for several physiological processes, including immune defense. Further, it has been implicated in the pathogenesis of developmental disorders and the onset of numerous diseases. Multiple modes of programmed cell death, including apoptosis, pyroptosis, necroptosis, and ferroptosis, have been identified, each with their own unique characteristics and biological implications. In February 2023, Liu Xiaoguang and his team discovered "disulfidptosis," a novel pathway of programmed cell death. Their findings demonstrated that disulfidptosis is triggered in glucose-starved cells exhibiting high expression of a protein called SLC7A11. Furthermore, disulfidptosis is marked by a drastic imbalance in the NADPH/NADP+ ratio and the abnormal accumulation of disulfides like cystine. These changes ultimately lead to the destabilization of the F-actin network, causing cell death. Given that high SLC7A11 expression is a key feature of certain cancers, these findings indicate that disulfidptosis could serve as the basis of innovative anti-cancer therapies. Hence, this review delves into the discovery of disulfidptosis, its underlying molecular mechanisms and metabolic regulation, and its prospective applications in disease treatment.
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Affiliation(s)
- Qiuyang Gu
- Institute of Forensic Sciences, Suzhou Medical College, Soochow University, Suzhou, China
| | - Yumei An
- Institute of Forensic Sciences, Suzhou Medical College, Soochow University, Suzhou, China
| | - Mingyuan Xu
- Institute of Forensic Sciences, Suzhou Medical College, Soochow University, Suzhou, China
| | - Xinqi Huang
- Institute of Forensic Sciences, Suzhou Medical College, Soochow University, Suzhou, China
| | - Xueshi Chen
- Institute of Forensic Sciences, Suzhou Medical College, Soochow University, Suzhou, China
| | - Xianzhe Li
- Institute of Forensic Sciences, Suzhou Medical College, Soochow University, Suzhou, China
| | - Haiyan Shan
- Department of Obstetrics and Gynecology, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, China
| | - Mingyang Zhang
- Institute of Forensic Sciences, Suzhou Medical College, Soochow University, Suzhou, China
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Li Y, Ren Q, Wang X, Luoreng Z, Wei D. Bta-miR-199a-3p Inhibits LPS-Induced Inflammation in Bovine Mammary Epithelial Cells via the PI3K/AKT/NF-κB Signaling Pathway. Cells 2022; 11:cells11213518. [PMID: 36359915 PMCID: PMC9656885 DOI: 10.3390/cells11213518] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/27/2022] [Accepted: 11/04/2022] [Indexed: 11/11/2022] Open
Abstract
Mastitis is characterized by inflammatory damage to mammary gland tissue, which could decline milk production and quality and significantly affect the economic benefits of ranching. MicroRNAs (miRNAs), such as miR-199a-3p, are novel therapeutic targets in inflammation, and their regulation is an effective strategy for inflammation control. Despite its importance in humans and animals, the molecular mechanism of bovine miR-199a-3p (bta-miR-199a-3p) in dairy cow mastitis and bovine mammary epithelial cell (bMEC) inflammation is unclear. In our study, a bovine mammary epithelial cell line (MAC-T) induced by lipopolysaccharide (LPS) was used as an inflammatory cell model to investigate the molecular mechanism of bta-miR-199a-3p in the MAC-T inflammatory response. bta-miR-199a-3p was up-regulated in the LPS-induced MAC-T cells, while CD2-associated protein (CD2AP) was revealed as its target gene in a double luciferase reporter gene experiment. In addition, the overexpression of bta-miR-199a-3p negatively regulated the expression of CD2AP and the activation of the phosphatidylinositol 3-kinase (PI3K)/AKT/nuclear factor kappa-B (NF-κB) signaling pathway. These subsequently inhibited the secretion of related inflammatory factors (TNF-α, IL-1β, and IL-6) and the expression of apoptotic genes (CASP3 and CASP9), thereby alleviating the LPS-challenged inflammatory response in the MAC-T cells. Silencing of bta-miR-199a-3p, however, reversed the above effects. Thus, bta-miR-199a-3p inhibits LPS-induced inflammation in bMECs by directly targeting CD2AP and regulating the PI3K/AKT/NF-κB signaling pathway. This study reveals the potential regulatory mechanism of bta-miR-199a-3p in bMEC inflammatory immune response and may serve as a useful target for the treatment of mastitis.
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Affiliation(s)
- Yuhang Li
- School of Agriculture, Ningxia University, Yinchuan 750021, China
- Key Laboratory of Ruminant Molecular Cell Breeding, Ningxia Hui Autonomous Region, Yinchuan 750021, China
| | - Qianqian Ren
- School of Agriculture, Ningxia University, Yinchuan 750021, China
- Key Laboratory of Ruminant Molecular Cell Breeding, Ningxia Hui Autonomous Region, Yinchuan 750021, China
| | - Xingping Wang
- School of Agriculture, Ningxia University, Yinchuan 750021, China
- Key Laboratory of Ruminant Molecular Cell Breeding, Ningxia Hui Autonomous Region, Yinchuan 750021, China
- Correspondence: (X.W.); (Z.L.)
| | - Zhuoma Luoreng
- School of Agriculture, Ningxia University, Yinchuan 750021, China
- Key Laboratory of Ruminant Molecular Cell Breeding, Ningxia Hui Autonomous Region, Yinchuan 750021, China
- Correspondence: (X.W.); (Z.L.)
| | - Dawei Wei
- School of Agriculture, Ningxia University, Yinchuan 750021, China
- Key Laboratory of Ruminant Molecular Cell Breeding, Ningxia Hui Autonomous Region, Yinchuan 750021, China
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Zhang H, Lin L, Liu J, Pan L, Lin Z, Zhang M, Zhang J, Cao Y, Zhu J, Zhang R. Phase Separation of MAGI2-Mediated Complex Underlies Formation of Slit Diaphragm Complex in Glomerular Filtration Barrier. J Am Soc Nephrol 2021; 32:1946-1960. [PMID: 34330769 PMCID: PMC8455267 DOI: 10.1681/asn.2020111590] [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: 11/12/2020] [Accepted: 03/22/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Slit diaphragm is a specialized adhesion junction between the opposing podocytes, establishing the final filtration barrier to urinary protein loss. At the cytoplasmic insertion site of each slit diaphragm there is an electron-dense and protein-rich cellular compartment that is essential for slit diaphragm integrity and signal transduction. Mutations in genes that encode components of this membrane-less compartment have been associated with glomerular diseases. However, the molecular mechanism governing formation of compartmentalized slit diaphragm assembly remains elusive. METHODS We systematically investigated the interactions between key components at slit diaphragm, such as MAGI2, Dendrin, and CD2AP, through a combination of biochemical, biophysical, and cell biologic approaches. RESULTS We demonstrated that MAGI2, a unique MAGUK family scaffold protein at slit diaphragm, can autonomously undergo liquid-liquid phase separation. Multivalent interactions among the MAGI2-Dendrin-CD2AP complex drive the formation of the highly dense slit diaphragm condensates at physiologic conditions. The reconstituted slit diaphragm condensates can effectively recruit Nephrin. A nephrotic syndrome-associated mutation of MAGI2 interfered with formation of the slit diaphragm condensates, thus leading to impaired enrichment of Nephrin. CONCLUSIONS Key components at slit diaphragm (e.g., MAGI2 and its complex) can spontaneously undergo phase separation. The reconstituted slit diaphragm condensates can be enriched in adhesion molecules and cytoskeletal adaptor proteins. Therefore, the electron-dense slit diaphragm assembly might form via phase separation of core components of the slit diaphragm in podocytes.
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Affiliation(s)
- Haijiao Zhang
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
| | - Lin Lin
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China
| | - Jianping Liu
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Lifeng Pan
- State Key Laboratory of Bioorganic and Natural Products Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Zhijie Lin
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Mingjie Zhang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China,School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Jiong Zhang
- School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ying Cao
- School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Jinwei Zhu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China
| | - Rongguang Zhang
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, China
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Nanjundaiah S, Chidambaram H, Chandrashekar M, Chinnathambi S. Role of Microglia in Regulating Cholesterol and Tau Pathology in Alzheimer's Disease. Cell Mol Neurobiol 2021; 41:651-668. [PMID: 32468440 DOI: 10.1007/s10571-020-00883-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 05/19/2020] [Indexed: 01/21/2023]
Abstract
Cholesterol, a principal constituent of the cell membrane, plays a crucial role in the brain by regulating the synaptic transmission, neuronal signaling, as well as neurodegenerative diseases. Defects in the cholesterol trafficking are associated with enhanced generation of hyperphosphorylated Tau and Amyloid-β protein. Tau, a major microtubule-associated protein in the brain, is the key regulator of the mature neuron. Abnormally hyperphosphorylated Tau hampers the major functions related to microtubule assembly by promoting neurofibrillary tangles of paired helical filaments, twisted ribbons, and straight filaments. The observed pathological changes due to impaired cholesterol and Tau protein accumulation cause Alzheimer's disease. Thus, in order to regulate the pathogenesis of Alzheimer's disease, regulation of cholesterol metabolism, as well as Tau phosphorylation, is essential. The current review provides an overview of (1) cholesterol synthesis in the brain, neurons, astrocytes, and microglia; (2) the mechanism involved in modulating cholesterol concentration between the astrocytes and brain; (3) major mechanisms involved in the hyperphosphorylation of Tau and amyloid-β protein; and (4) microglial involvement in its regulation. Thus, the answering key questions will provide an in-depth information on microglia involvement in managing the pathogenesis of cholesterol-modulated hyperphosphorylated Tau protein.
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Affiliation(s)
- Shwetha Nanjundaiah
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune, 411008, India
| | - Hariharakrishnan Chidambaram
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune, 411008, India
- Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110025, India
| | - Madhura Chandrashekar
- School of Biomedical Engineering and Sciences, MIT University, Loni Kalbhor, Pune, 412201, India
| | - Subashchandrabose Chinnathambi
- Neurobiology Group, Division of Biochemical Sciences, CSIR-National Chemical Laboratory (CSIR-NCL), Dr. Homi Bhabha Road, Pune, 411008, India.
- Academy of Scientific and Innovative Research (AcSIR), New Delhi, 110025, India.
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Bolus H, Crocker K, Boekhoff-Falk G, Chtarbanova S. Modeling Neurodegenerative Disorders in Drosophila melanogaster. Int J Mol Sci 2020; 21:E3055. [PMID: 32357532 PMCID: PMC7246467 DOI: 10.3390/ijms21093055] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/14/2020] [Accepted: 04/21/2020] [Indexed: 12/12/2022] Open
Abstract
Drosophila melanogaster provides a powerful genetic model system in which to investigate the molecular mechanisms underlying neurodegenerative diseases. In this review, we discuss recent progress in Drosophila modeling Alzheimer's Disease, Parkinson's Disease, Amyotrophic Lateral Sclerosis (ALS), Huntington's Disease, Ataxia Telangiectasia, and neurodegeneration related to mitochondrial dysfunction or traumatic brain injury. We close by discussing recent progress using Drosophila models of neural regeneration and how these are likely to provide critical insights into future treatments for neurodegenerative disorders.
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Affiliation(s)
- Harris Bolus
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487, USA;
| | - Kassi Crocker
- Genetics Graduate Training Program, School of Medicine and Public Health, University of Wisconsin–Madison, Madison, WI 53705, USA;
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin–Madison, Madison, WI 53705, USA
| | - Grace Boekhoff-Falk
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin–Madison, Madison, WI 53705, USA
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Abstract
Arterial hypertension has a large prevalence in the general population and as a major hypertensive target organ, the involvement of kidney is usually hard to avoid and gradually develops into chronic kidney disease (CKD). Acute hypertension is defined as a blood pressure greater than 180/120, also known as hypertensive emergency (HE). In acute severe hypertension, the pathophysiology damage to the kidney tends to worsen on the basis of chronic damage, and accounts for more significant mortality. However, the mechanisms of renal injury induced by acute hypertension remain unclear. This review summarizes the clinical and histopathological features of hypertensive renal injury by using "in vivo cyrotechnique" and focusses on the interplay of distinct systemic signaling pathways, which drive glomerular podocyte injury. A thorough understanding of the cellular and molecular mechanisms of kidney damage and repair in hypertension will provide significant insight into the development of new research methods and therapeutic strategies for global CKD progression.
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Xie W, Chen C, Han Z, Huang J, Liu X, Chen H, Zhang T, Chen S, Chen C, Lu M, Shen X, Xue X. CD2AP inhibits metastasis in gastric cancer by promoting cellular adhesion and cytoskeleton assembly. Mol Carcinog 2020; 59:339-352. [PMID: 31989722 PMCID: PMC7078920 DOI: 10.1002/mc.23158] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 12/29/2019] [Accepted: 01/13/2020] [Indexed: 12/15/2022]
Abstract
Diffuse gastric cancer (DGC) is a lethal malignancy lacking effective systemic therapy. Among the most provocative recent results in DGC has been that the alter of the cellular cytoskeleton and intercellular adhesion. CD2‐associated protein (CD2AP) is one of the critical proteins regulating cytoskeleton assembly and intercellular adhesion. However, no study has investigated the expression and biological significance of CD2AP in gastric cancer (GC) to date. Therefore, the aim of our study was to explore if the expression of CD2AP is associated with any clinical features of GC and to elucidate the underlying mechanism. Immunohistochemistry of 620 patient tissue samples indicated that the expression of CD2AP is downregulated in DGC. Moreover, a low CD2AP level was indicative of poor patient prognosis. In vitro, forced expression of CD2AP caused a significant decrease in the migration and invasion of GC cells, whereas depletion of CD2AP had the opposite effect. Immunofluorescence analysis indicated that CD2AP promoted cellular adhesion and influenced cell cytoskeleton assembly via interaction with the F‐actin capping protein CAPZA1. Overall, the upregulation of CD2AP could attenuate GC metastasis, suggesting CD2AP as a novel biomarker for the prognosis and treatment of patients with GC.
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Affiliation(s)
- Wangkai Xie
- Department of General Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Department of Microbiology and Immunology, School of Basic Medical Science, Institute of Molecular Virology and Immunology, Institute of Tropical Medicine, Wenzhou Medical University, Wenzhou, China
| | - Chao Chen
- Department of Microbiology and Immunology, School of Basic Medical Science, Institute of Molecular Virology and Immunology, Institute of Tropical Medicine, Wenzhou Medical University, Wenzhou, China.,Department of Oncology, Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine Affiliated to Zhejiang Chinese Medical University, Wenzhou, China
| | - Zheng Han
- Department of General Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Department of Microbiology and Immunology, School of Basic Medical Science, Institute of Molecular Virology and Immunology, Institute of Tropical Medicine, Wenzhou Medical University, Wenzhou, China
| | - Jingjing Huang
- Department of General Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xin Liu
- Department of General Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Department of Microbiology and Immunology, School of Basic Medical Science, Institute of Molecular Virology and Immunology, Institute of Tropical Medicine, Wenzhou Medical University, Wenzhou, China
| | - Hongjun Chen
- Department of Microbiology and Immunology, School of Basic Medical Science, Institute of Molecular Virology and Immunology, Institute of Tropical Medicine, Wenzhou Medical University, Wenzhou, China
| | - Teming Zhang
- Department of General Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Department of Microbiology and Immunology, School of Basic Medical Science, Institute of Molecular Virology and Immunology, Institute of Tropical Medicine, Wenzhou Medical University, Wenzhou, China
| | - Sian Chen
- Department of General Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Chenbin Chen
- Department of General Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Department of Microbiology and Immunology, School of Basic Medical Science, Institute of Molecular Virology and Immunology, Institute of Tropical Medicine, Wenzhou Medical University, Wenzhou, China
| | - Mingdong Lu
- Department of General Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xian Shen
- Department of General Surgery, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xiangyang Xue
- Department of Microbiology and Immunology, School of Basic Medical Science, Institute of Molecular Virology and Immunology, Institute of Tropical Medicine, Wenzhou Medical University, Wenzhou, China
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Zheng J, Zhang S, Chen H, Cai X, Zhang C, Li S, Zhou Y, Shang J, Liang S, Yao F. Protosappanin-A and oleanolic acid protect injured podocytes from apoptosis through inhibition of AKT-mTOR signaling. Cell Biol Int 2020; 44:189-199. [PMID: 31441181 PMCID: PMC6973098 DOI: 10.1002/cbin.11218] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 08/18/2019] [Indexed: 01/24/2023]
Abstract
Protosappanin-A (PrA) and oleanolic acid (OA), which are important effective ingredients isolated from Caesalpinia sappan L., exhibit therapeutic potential in multiple diseases. This study focused on exploring the mechanisms of PrA and OA function in podocyte injury. An in vitro model of podocyte injury was induced by the sC5b-9 complex and assays such as cell viability, apoptosis, immunofluorescence, quantitative real-time polymerase chain reaction, and western blot were performed to further investigate the effects and mechanisms of PrA and OA in podocyte injury. The models of podocyte injury were verified to be successful as seen through significantly decreased levels of nephrin, podocin, and CD2AP and increased level of desmin. The sC5b-9-induced podocyte apoptosis was inhibited in injured podocytes treated with PrA and OA, accompanied by increased protein levels of nephrin, podocin, CD2AP, and Bcl2 and decreased levels of desmin and Bax. The p-AKT/p-mTOR levels were also reduced by treatment of PrA and OA while AKT/mTOR was unaltered. Further, the effects of PrA and OA on injured podocytes were similar to that of LY294002 (a PI3K-AKT inhibitor). PrA and OA were also seen to inhibit podocyte apoptosis and p-AKT/p-mTOR levels induced by IGF-1 (a PI3K-AKT activator). Our data demonstrate that PrA and OA can protect podocytes from injury or apoptosis, which may occur through inhibition of the abnormal activation of AKT-mTOR signaling.
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Affiliation(s)
- Jiaxin Zheng
- Department of NephrologyHeilongjiang Academy of Traditional Chinese MedicineHarbinHeilongjiang150036PR China
| | - Shoulin Zhang
- Department of NephrologyThe Affiliated Hospital to Changchun University of Chinese MedicineChangchunJilin130021PR China
| | - Huijun Chen
- Department of CardiologyThe Second Hospital Affiliated Heilongjiang University of Traditional Chinese MedicineHarbinHeilongjiang150009PR China
| | - Xiaojun Cai
- Department of NephrologyHeilongjiang Academy of Traditional Chinese MedicineHarbinHeilongjiang150036PR China
| | - Chunjian Zhang
- Department of NephrologyHeilongjiang Academy of Traditional Chinese MedicineHarbinHeilongjiang150036PR China
| | - Shuhua Li
- Department of NephrologyHeilongjiang Academy of Traditional Chinese MedicineHarbinHeilongjiang150036PR China
| | - Yabin Zhou
- Department of CardiologyThe First Hospital Affiliated Heilongjiang University of Traditional Chinese MedicineHarbinHeilongjiang150040PR China
| | - Jing Shang
- Department of NephrologyHeilongjiang Academy of Traditional Chinese MedicineHarbinHeilongjiang150036PR China
| | - Shunyu Liang
- Department of NephrologyHeilongjiang Academy of Traditional Chinese MedicineHarbinHeilongjiang150036PR China
| | - Fengzhen Yao
- Department of NephrologyHeilongjiang University of Traditional Chinese MedicineHarbinHeilongjiang150040PR China
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Sun D, Wang JJ, Wang W, Wang J, Wang LN, Yao L, Sun YH, Li ZL. Human podocyte injury in the early course of hypertensive renal injury. World J Clin Cases 2019; 7:3698-3710. [PMID: 31799294 PMCID: PMC6887599 DOI: 10.12998/wjcc.v7.i22.3698] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 11/03/2019] [Accepted: 11/15/2019] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Hypertension is prevalent in the general population and is regarded as the second leading cause of renal damage and dysfunction, outnumbered only by diabetes. However, the mechanisms remain unclear.
AIM To investigate podocyte injury induced by hypertension in the early course without massive proteinuria or renal dysfunction.
METHODS The hypertension group comprised 18 patients with hypertension accompanied by microalbuminuria, diagnosed with hypertensive renal injury according to biopsy results. For a comparison of pathological changes in renal tissue, control group 1 comprised 10 healthy volunteers, and control group 2 comprised 16 patients who underwent surgery for renal trauma.
RESULTS The hypertension group had significantly higher blood pressure (P = 0.000) and microalbuminuria (P = 0.000) compared with control group 1. In the hypertension group, urinary podocytes were detected following positive staining of podocyte-specific nephrin and/or CD2-associated protein (CD2AP) in urine sediment. Podocyte foot process fusion and a significant decrease in nephrin and/or CD2AP expression in glomeruli were observed in the hypertension group compared with control group 2. This indicated that hypertension caused podocyte injury and detachment from the glomerular basement membrane, which was consistent with urinary detection of podocytes.
CONCLUSION Our results suggest that podocyturia appears early in the course of hypertensive renal injury, and may be a sensitive marker for early prediction of hypertensive renal injury.
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Affiliation(s)
- Da Sun
- Department of Nephrology, The First Hospital of China Medical University, Shenyang 110001, Liaoning Province, China
| | - Jiao-Jiao Wang
- Department of Nephrology, The First Hospital of China Medical University, Shenyang 110001, Liaoning Province, China
| | - Wei Wang
- Department of Nephrology, The First Hospital of China Medical University, Shenyang 110001, Liaoning Province, China
| | - Juan Wang
- Department of Nephrology, The First Hospital of China Medical University, Shenyang 110001, Liaoning Province, China
| | - Li-Ning Wang
- Department of Nephrology, The First Hospital of China Medical University, Shenyang 110001, Liaoning Province, China
| | - Li Yao
- Department of Nephrology, The First Hospital of China Medical University, Shenyang 110001, Liaoning Province, China
| | - Ying-Hui Sun
- Department of Experimental Medicine, General Hospital of Northern Theater Command, Shenyang 110016, Liaoning Province, China
| | - Zi-Long Li
- Department of Nephrology, The First Hospital of China Medical University, Shenyang 110001, Liaoning Province, China
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10
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Guimas Almeida C, Sadat Mirfakhar F, Perdigão C, Burrinha T. Impact of late-onset Alzheimer's genetic risk factors on beta-amyloid endocytic production. Cell Mol Life Sci 2018; 75:2577-2589. [PMID: 29704008 PMCID: PMC11105284 DOI: 10.1007/s00018-018-2825-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 04/04/2018] [Accepted: 04/23/2018] [Indexed: 12/21/2022]
Abstract
The increased production of the 42 aminoacids long beta-amyloid (Aβ42) peptide has been established as a causal mechanism of the familial early onset Alzheimer's disease (AD). In contrast, the causal mechanisms of the late-onset AD (LOAD), that affects most AD patients, remain to be established. Indeed, Aβ42 accumulation has been detected more than 30 years before diagnosis. Thus, the mechanisms that control Aβ accumulation in LOAD likely go awry long before pathogenesis becomes detectable. Early on, APOE4 was identified as the biggest genetic risk factor for LOAD. However, since APOE4 is not present in all LOAD patients, genome-wide association studies of thousands of LOAD patients were undertaken to identify other genetic variants that could explain the development of LOAD. PICALM, BIN1, CD2AP, SORL1, and PLD3 are now with APOE4 among the identified genes at highest risk in LOAD that have been implicated in Aβ42 production. Recent evidence indicates that the regulation of the endocytic trafficking of the amyloid precursor protein (APP) and/or its secretases to and from sorting endosomes is determinant for Aβ42 production. Thus, here, we will review the described mechanisms, whereby these genetic risk factors can contribute to the enhanced endocytic production of Aβ42. Dissecting causal LOAD mechanisms of Aβ42 accumulation, underlying the contribution of each genetic risk factor, will be required to identify therapeutic targets for novel personalized preventive strategies.
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Affiliation(s)
- Cláudia Guimas Almeida
- Neuronal Trafficking in Aging Lab, CEDOC, Chronic Diseases Research Centre, NOVA Medical School|Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Campo Mártires da Pátria, 130, 1169-056, Lisbon, Portugal.
| | - Farzaneh Sadat Mirfakhar
- Neuronal Trafficking in Aging Lab, CEDOC, Chronic Diseases Research Centre, NOVA Medical School|Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Campo Mártires da Pátria, 130, 1169-056, Lisbon, Portugal
| | - Catarina Perdigão
- Neuronal Trafficking in Aging Lab, CEDOC, Chronic Diseases Research Centre, NOVA Medical School|Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Campo Mártires da Pátria, 130, 1169-056, Lisbon, Portugal
| | - Tatiana Burrinha
- Neuronal Trafficking in Aging Lab, CEDOC, Chronic Diseases Research Centre, NOVA Medical School|Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Campo Mártires da Pátria, 130, 1169-056, Lisbon, Portugal
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Sun Q, Xie N, Tang B, Li R, Shen Y. Alzheimer's Disease: From Genetic Variants to the Distinct Pathological Mechanisms. Front Mol Neurosci 2017; 10:319. [PMID: 29056900 PMCID: PMC5635057 DOI: 10.3389/fnmol.2017.00319] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 09/20/2017] [Indexed: 11/13/2022] Open
Abstract
Being the most common cause of dementia, AD is a polygenic and neurodegenerative disease. Complex and multiple factors have been shown to be involved in its pathogenesis, of which the genetics play an indispensable role. It is widely accepted that discovery of potential genes related to the pathogenesis of AD would be of great help for the understanding of neurodegeneration and thus further promote molecular diagnosis in clinic settings. Generally, AD could be clarified into two types according to the onset age, the early-onset AD (EOAD) and the late-onset AD (LOAD). Progresses made by genetic studies on both EOAD and LOAD are believed to be essential not only for the revolution of conventional ideas but also for the revelation of new pathological mechanisms underlying AD pathogenesis. Currently, albeit the genetics of LOAD is much less well-understood compared to EOAD due to its complicated and multifactorial essence, Genome-wide association studies (GWASs) and next generation sequencing (NGS) approaches have identified dozens of novel genes that may provide insight mechanism of LOAD. In this review, we analyze functions of the genes and summarize the distinct pathological mechanisms of how these genes would be involved in the pathogenesis of AD.
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Affiliation(s)
- Qiying Sun
- Department of Geriatric Neurology, Xiangya Hospital, Central South University, Changsha, China.,Center for Advanced Therapeutic Strategies for Brain Disorders and Center for Hormone Advanced Science and Education, Roskamp Institute, Sarasota, FL, United States
| | - Nina Xie
- Department of Geriatric Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Beisha Tang
- Department of Geriatric Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Rena Li
- Center for Advanced Therapeutic Strategies for Brain Disorders and Center for Hormone Advanced Science and Education, Roskamp Institute, Sarasota, FL, United States.,National Clinical Research Center for Mental Disorders, Beijing Key Laboratory of Mental Disorders, Beijing Anding Hospital, Capital Medical University, Beijing, China.,Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
| | - Yong Shen
- Department of Geriatric Neurology, Xiangya Hospital, Central South University, Changsha, China.,Center for Advanced Therapeutic Strategies for Brain Disorders and Center for Hormone Advanced Science and Education, Roskamp Institute, Sarasota, FL, United States.,Neurodegenerative Disorder Research Center, University of Science and Technology of China School of Life Sciences, Hefei, China.,Hefei Material Science at Microscale National Laboratory, Hefei, China
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12
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Tsuji K, Suleiman H, Miner JH, Daley JM, Capen DE, Păunescu TG, Lu HAJ. Ultrastructural Characterization of the Glomerulopathy in Alport Mice by Helium Ion Scanning Microscopy (HIM). Sci Rep 2017; 7:11696. [PMID: 28916834 PMCID: PMC5601433 DOI: 10.1038/s41598-017-12064-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 09/01/2017] [Indexed: 01/19/2023] Open
Abstract
The glomerulus exercises its filtration barrier function by establishing a complex filtration apparatus consisting of podocyte foot processes, glomerular basement membrane and endothelial cells. Disruption of any component of the glomerular filtration barrier leads to glomerular dysfunction, frequently manifested as proteinuria. Ultrastructural studies of the glomerulus by transmission electron microscopy (TEM) and conventional scanning electron microscopy (SEM) have been routinely used to identify and classify various glomerular diseases. Here we report the application of newly developed helium ion scanning microscopy (HIM) to examine the glomerulopathy in a Col4a3 mutant/Alport syndrome mouse model. Our study revealed unprecedented details of glomerular abnormalities in Col4a3 mutants including distorted podocyte cell bodies and disorganized primary processes. Strikingly, we observed abundant filamentous microprojections arising from podocyte cell bodies and processes, and presence of unique bridging processes that connect the primary processes and foot processes in Alport mice. Furthermore, we detected an altered glomerular endothelium with disrupted sub-endothelial integrity. More importantly, we were able to clearly visualize the complex, three-dimensional podocyte and endothelial interface by HIM. Our study demonstrates that HIM provides nanometer resolution to uncover and rediscover critical ultrastructural characteristics of the glomerulopathy in Col4a3 mutant mice.
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Affiliation(s)
- Kenji Tsuji
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
| | - Hani Suleiman
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA.,Division of Nephrology, Washington University School of Medicine, St. Louis, MO, USA
| | - Jeffrey H Miner
- Division of Nephrology, Washington University School of Medicine, St. Louis, MO, USA
| | - James M Daley
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Diane E Capen
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
| | - Teodor G Păunescu
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
| | - Hua A Jenny Lu
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA.
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13
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Tsuji K, Păunescu TG, Suleiman H, Xie D, Mamuya FA, Miner JH, Lu HAJ. Re-characterization of the Glomerulopathy in CD2AP Deficient Mice by High-Resolution Helium Ion Scanning Microscopy. Sci Rep 2017; 7:8321. [PMID: 28814739 PMCID: PMC5559584 DOI: 10.1038/s41598-017-08304-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 07/06/2017] [Indexed: 01/22/2023] Open
Abstract
Helium ion scanning microscopy (HIM) is a novel technology that directly visualizes the cell surface ultrastructure without surface coating. Despite its very high resolution, it has not been applied extensively to study biological or pathology samples. Here we report the application of this powerful technology to examine the three-dimensional ultrastructural characteristics of proteinuric glomerulopathy in mice with CD2-associated protein (CD2AP) deficiency. HIM revealed the serial alteration of glomerular features including effacement and disorganization of the slit diaphragm, followed by foot process disappearance, flattening and fusion of major processes, and eventual transformation into a podocyte sheet as the disease progressed. The number and size of the filtration slit pores decreased. Strikingly, numerous “bleb” shaped microprojections were observed extending from podocyte processes and cell body, indicating significant membrane dynamics accompanying CD2AP deficiency. Visualizing the glomerular endothelium and podocyte-endothelium interface revealed the presence of endothelial damage, and disrupted podocyte and endothelial integrity in 6 week-old Cd2ap-KO mice. We used the HIM technology to investigate at nanometer scale resolution the ultrastructural alterations of the glomerular filtration apparatus in mice lacking the critical slit diaphragm-associated protein CD2AP, highlighting the great potential of HIM to provide new insights into the biology and (patho)physiology of glomerular diseases.
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Affiliation(s)
- Kenji Tsuji
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
| | - Teodor G Păunescu
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
| | - Hani Suleiman
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO, USA.,Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Dongping Xie
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
| | - Fahmy A Mamuya
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA
| | - Jeffrey H Miner
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Hua A Jenny Lu
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Department of Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, MA, USA.
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14
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Kaul Z, Chakrabarti O. Tumor susceptibility gene 101 regulates predisposition to apoptosis via ESCRT machinery accessory proteins. Mol Biol Cell 2017; 28:2106-2122. [PMID: 28539405 PMCID: PMC5509423 DOI: 10.1091/mbc.e16-12-0855] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 05/11/2017] [Accepted: 05/16/2017] [Indexed: 12/21/2022] Open
Abstract
ESCRT proteins are implicated in myriad cellular processes, including endosome formation, fusion of autophagosomes/amphisomes with lysosomes, and apoptosis. The role played by these proteins in either facilitating or protecting against apoptosis is unclear. In this study, while trying to understand how deficiency of Mahogunin RING finger 1 (MGRN1) affects cell viability, we uncovered a novel role for its interactor, the ESCRT-I protein TSG101: it directly participates in mitigating ER stress-mediated apoptosis. The association of TSG101 with ALIX prevents predisposition to apoptosis, whereas ALIX-ALG-2 interaction favors a death phenotype. Altered Ca2+ homeostasis in cells and a simultaneous increase in the protein levels of ALIX and ALG-2 are required to elicit apoptosis by activating ER stress-associated caspase 4/12. We further demonstrate that in the presence of membrane-associated, disease-causing prion protein CtmPrP, increased ALIX and ALG-2 levels are detected along with ER stress markers and associated caspases in transgenic brain lysates and cells. These effects were rescued by overexpression of TSG101. This is significant because MGRN1 deficiency is closely associated with neurodegeneration and prenatal and neonatal mortality, which could be due to excess cell death in selected brain regions or myocardial apoptosis during embryonic development.
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Affiliation(s)
- Zenia Kaul
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata 700064, India
| | - Oishee Chakrabarti
- Biophysics and Structural Genomics Division, Saha Institute of Nuclear Physics, Kolkata 700064, India
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15
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Rahman MR, Tajmim A, Ali M, Sharif M. Overview and Current Status of Alzheimer's Disease in Bangladesh. J Alzheimers Dis Rep 2017; 1:27-42. [PMID: 30480227 PMCID: PMC6159651 DOI: 10.3233/adr-170012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Alzheimer’s disease (AD) is a complex neurological disorder with economic, social, and medical burdens which is acknowledged as leading cause of dementia marked by the accumulation and aggregation of amyloid-β peptide and phosphorylated tau (p-tau) protein and concomitant dementia, neuron loss and brain atrophy. AD is the most prevalent neurodegenerative brain disorder with sporadic etiology, except for a small fraction of cases with familial inheritance where familial forms of AD are correlated to mutations in three functionally related genes: the amyloid-β protein precursor and presenilins 1 and 2, two key γ-secretase components. The common clinical features of AD are memory impairment that interrupts daily life, difficulty in accomplishing usual tasks, confusion with time or place, trouble understanding visual images and spatial relationships. Age is the most significant risk factor for AD, whereas other risk factors correlated with AD are hypercholesterolemia, hypertension, atherosclerosis, coronary heart disease, smoking, obesity, and diabetes. Despite decades of research, there is no satisfying therapy which will terminate the advancement of AD by acting on the origin of the disease process, whereas currently available therapeutics only provide symptomatic relief but fail to attain a definite cure and prevention. This review also represents the current status of AD in Bangladesh.
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Affiliation(s)
- Md Rashidur Rahman
- Department of Pharmacy, Jessore University of Science and Technology, Jessore, Bangladesh
| | - Afsana Tajmim
- Department of Pharmacy, Jessore University of Science and Technology, Jessore, Bangladesh
| | - Mohammad Ali
- Department of Pharmacy, Jessore University of Science and Technology, Jessore, Bangladesh
| | - Mostakim Sharif
- Department of Pharmacy, Jessore University of Science and Technology, Jessore, Bangladesh
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16
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Xiao Q, Liu ZJ, Tao S, Sun YM, Jiang D, Li HL, Chen H, Liu X, Lapin B, Wang CH, Zheng SL, Xu J, Wu ZY. Risk prediction for sporadic Alzheimer's disease using genetic risk score in the Han Chinese population. Oncotarget 2016; 6:36955-64. [PMID: 26543236 PMCID: PMC4741908 DOI: 10.18632/oncotarget.6271] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 09/22/2015] [Indexed: 01/10/2023] Open
Abstract
More than 30 independent single-nucleotide polymorphisms (SNPs) have been associated with Alzheimer's disease (AD) risk by genome-wide association studies (GWAS) in European. We aimed to confirm these SNPs in Chinese Han and investigate the utility of these genetic markers. We randomly divided 459 sporadic AD (SAD) patients and 751 cognitively normal controls into two sets (discovery and testing). Thirty-three SAD risk-associated SNPs were firstly tested in the discovery set. Significant SNPs were used to calculate genetic risk score (GRS) in the testing set. Predictive performance of GRS was evaluated using the area under the receiver operating characteristic curve (AUC). In the discovery set, 6 SNPs were confirmed (P = 7.87 × 10−11~0.048), including rs9349407 in CD2AP, rs11218343 in SORL1, rs17125944 in FERMT2, rs6859 in PVRL2, rs157580 and rs2075650 in TOMM40. The first three SNPs were associated with SAD risk independent of APOE genotypes. GRS based on these three SNPs were significantly associated with SAD risk in the independent testing set (P = 0.002). The AUC for discriminating cases from controls was 0.58 for GRS, 0.60 for APOE, and 0.64 for GRS and APOE. Our data demonstrated that GRS based on AD risk-associated SNPs may supplement APOE for better assessing individual risk for AD in Chinese.
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Affiliation(s)
- Qianyi Xiao
- Center for Genomic Translational Medicine and Prevention, School of Public Health, Fudan University, Shanghai, China
| | - Zhi-Jun Liu
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and the Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, China.,Department of Neurology and Institute of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Sha Tao
- Center for Genomic Translational Medicine and Prevention, School of Public Health, Fudan University, Shanghai, China
| | - Yi-Min Sun
- Department of Neurology and Institute of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Deke Jiang
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China
| | - Hong-Lei Li
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and the Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, China
| | - Haitao Chen
- Center for Genomic Translational Medicine and Prevention, School of Public Health, Fudan University, Shanghai, China
| | - Xu Liu
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China
| | - Brittany Lapin
- Program for Personalized Cancer Care, NorthShore University Health System, Evanston, IL, USA
| | - Chi-Hsiung Wang
- Program for Personalized Cancer Care, NorthShore University Health System, Evanston, IL, USA
| | - S Lilly Zheng
- State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China.,Program for Personalized Cancer Care, NorthShore University Health System, Evanston, IL, USA
| | - Jianfeng Xu
- Center for Genomic Translational Medicine and Prevention, School of Public Health, Fudan University, Shanghai, China.,State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, China.,Program for Personalized Cancer Care, NorthShore University Health System, Evanston, IL, USA.,Fudan Institute of Urology, Huashan Hospital, Fudan University, Shanghai, China
| | - Zhi-Ying Wu
- Department of Neurology and Research Center of Neurology in Second Affiliated Hospital, and the Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hangzhou, China
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17
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Zhang YM, Gu QH, Huang J, Qu Z, Wang X, Meng LQ, Wang F, Liu G, Cui Z, Zhao MH. Clinical Significance of IgM and C3 Glomerular Deposition in Primary Focal Segmental Glomerulosclerosis. Clin J Am Soc Nephrol 2016; 11:1582-1589. [PMID: 27340287 PMCID: PMC5012474 DOI: 10.2215/cjn.01190216] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 05/26/2016] [Indexed: 12/15/2022]
Abstract
BACKGROUND AND OBJECTIVES Glomerular IgM deposition is commonly shown in primary FSGS and sometimes accompanied by C3 deposition. Clinical presentation and treatment outcomes of these patients are not investigated in detail. DESIGN, SETTING, PARTICIPANTS, &MEASUREMENTS One hundred six consecutive patients with biopsy-proven primary FSGS from 2004 to 2014 were enrolled retrospectively. Clinical features and treatment outcomes were compared between patients with and without IgM/C3 deposition. RESULTS Fifty-eight (54.7%) patients presented with IgM glomerular deposition on sclerotic segments. C3 and C1q depositions were shown exclusively in patients with IgM deposition (34.5% versus 0.0%; P<0.001 and 8.6% versus 0.0%; P=0.04, respectively). Patients with IgM deposition were younger (median; range: 24.5; 18.8-39.0 versus 46.5; 26.0-64.0 years old; P=0.001), had higher level of serum IgM (142.5; 96.3-206.0 versus 107.0; 71.0-140.0 mg/dl; P=0.01), and had higher level of eGFR (median; range 97.7; 48.0-135.8 versus 62.1; 33.7-93.9 ml/min per 1.73 m(2); P=0.01) at the time of kidney biopsy. The percentage of sclerosis lesions was significantly higher in patients with C3 deposition (median; range: 21.7%; 15.3%-31.1% versus 9.2%; 6.6%-20.0%; P=0.002). Although patients received comparable immunosuppressive treatments during 58.9 (29.5-81.1) months of follow-up, a significantly higher prevalence of refractory cases (no response or steroid dependent) occurred in patients with combined IgM and C3 deposition compared with patients with IgM deposition alone or without IgM deposition (58.8% versus 22.2% versus 15.6%, respectively; P=0.004). Multivariate analysis identified combined IgM and C3 deposition (odds ratio, 11.32; 95% confidence interval, 2.26 to 56.65; P=0.003) as an independent risk factor for refractory patients; 19 of 98 patients developed renal dysfunction when their serum creatinine levels increased >30% from baseline and reached >1.5 mg/dl. Combined IgM and C3 deposition (hazard ratio, 5.67; 95% confidence interval, 1.34 to 23.84; P=0.02) was identified as an independent risk factor for renal dysfunction. CONCLUSIONS Patients with primary FSGS and IgM and C3 deposition showed unfavorable therapeutic responses and worse renal outcomes, which indicate that IgM and C3 deposition might involve disease progression via complement activation.
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Affiliation(s)
- Yi-miao Zhang
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
- Institute of Nephrology, Peking University, Beijing, China
- Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China
- Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China; and
| | - Qiu-hua Gu
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
- Institute of Nephrology, Peking University, Beijing, China
- Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China
- Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China; and
| | - Jing Huang
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
- Institute of Nephrology, Peking University, Beijing, China
- Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China
- Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China; and
| | - Zhen Qu
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
- Institute of Nephrology, Peking University, Beijing, China
- Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China
- Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China; and
| | - Xin Wang
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
- Institute of Nephrology, Peking University, Beijing, China
- Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China
- Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China; and
| | - Li-qiang Meng
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
- Institute of Nephrology, Peking University, Beijing, China
- Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China
- Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China; and
| | - Fang Wang
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
- Institute of Nephrology, Peking University, Beijing, China
- Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China
- Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China; and
| | - Gang Liu
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
- Institute of Nephrology, Peking University, Beijing, China
- Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China
- Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China; and
| | - Zhao Cui
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
- Institute of Nephrology, Peking University, Beijing, China
- Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China
- Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China; and
| | - Ming-hui Zhao
- Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China
- Institute of Nephrology, Peking University, Beijing, China
- Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China
- Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China; and
- Peking-Tsinghua Center for Life Sciences, Beijing, China
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18
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Kühn J, Wong LE, Pirkuliyeva S, Schulz K, Schwiegk C, Fünfgeld KG, Keppler S, Batista FD, Urlaub H, Habeck M, Becker S, Griesinger C, Wienands J. The adaptor protein CIN85 assembles intracellular signaling clusters for B cell activation. Sci Signal 2016; 9:ra66. [PMID: 27353366 DOI: 10.1126/scisignal.aad6275] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The adaptor molecule Cbl-interacting protein of 85 kD (CIN85) regulates signaling from a number of cell surface receptors, such as growth factor receptors and antigen receptors on lymphocytes. Because of its multidomain structure, CIN85 is thought to act as a classical adaptor protein that connects functionally distinct components of a given signaling pathway through diverse protein domains. However, we found that in B lymphocytes, CIN85 functions to oligomerize SLP-65, which is the central effector protein of the B cell receptor (BCR). Therefore, CIN85 trimerizes through a carboxyl-terminal, coiled-coil domain. The multiple Src homology 3 (SH3) domains of trimeric CIN85 molecules associated with multiple SLP-65 molecules, which recruited further CIN85 trimers, thereby perpetuating the oligomerization process. Formation of this oligomeric signaling complex in resting B cells rendered the cells poised for the efficient initiation of intracellular signaling upon BCR stimulation. Our data suggest that the functionality of signaling cascades does not rely solely on the qualitative linkage of their various components but requires a critical number of effectors to become concentrated in signaling complexes.
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Affiliation(s)
- Julius Kühn
- Institute of Cellular and Molecular Immunology, Georg August University of Göttingen, Humboldtallee 34, 37073 Göttingen, Germany
| | - Leo E Wong
- Department of NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Sona Pirkuliyeva
- Institute of Cellular and Molecular Immunology, Georg August University of Göttingen, Humboldtallee 34, 37073 Göttingen, Germany
| | - Kathrin Schulz
- Institute of Cellular and Molecular Immunology, Georg August University of Göttingen, Humboldtallee 34, 37073 Göttingen, Germany
| | - Claudia Schwiegk
- Department of NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Kevser Gencalp Fünfgeld
- Department for Cellular Logistic, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Selina Keppler
- Lymphocyte Interaction Laboratory, London Research Institute, Cancer Research UK, Lincoln's Inn Fields 44, London WC2A 3LY, UK
| | - Facundo D Batista
- Lymphocyte Interaction Laboratory, London Research Institute, Cancer Research UK, Lincoln's Inn Fields 44, London WC2A 3LY, UK
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany. Bioanalytics Group, Institute for Clinical Chemistry, University Medical Center, Robert-Koch-Strasse 40, 37075 Göttingen, Germany
| | - Michael Habeck
- Statistical Inverse Problems in Biophysics, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Stefan Becker
- Department of NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Christian Griesinger
- Department of NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
| | - Jürgen Wienands
- Institute of Cellular and Molecular Immunology, Georg August University of Göttingen, Humboldtallee 34, 37073 Göttingen, Germany.
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19
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Sugimoto K, Miyazawa T, Enya T, Miyazaki K, Okada M, Takemura T. Cyclosporine A induced histological changes of Cathepsin L and CD2AP expression in renal glomeruli and tubules. Clin Exp Nephrol 2016; 21:83-91. [PMID: 26975192 DOI: 10.1007/s10157-016-1257-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 03/03/2016] [Indexed: 01/09/2023]
Abstract
BACKGROUND Cyclosporine A (CsA) is used globally as an immunosuppressant for the treatment of immune-mediated nephrotic syndrome (NS). However, its long-term use causes nephrotoxicity characterized by tubulointerstitial injury and glomerulosclerosis. The present study aimed to investigate the associations between histomorphological findings and immunohistological expression of Cathepsin L (CatL) and CD2-associated protein (CD2AP) in patients with NS mediated with CsA. METHODS A total of 18 patients with child-onset NS were divided into two groups after treatment with CsA for 2 years (group A; n = 10) and more than 4 years (group B; n = 8), respectively. Analyses of relationships between tubulointerstitial disorders and expression of CatL and CD2AP proteins were performed using immunohistochemistry of paired renal specimens. RESULTS Glomeruli with arteriole hyalinization were significantly increased in both groups depending on dosage periods, although degrees of tubule and interstitial injury did not differ between groups. CD2AP expression was significantly greater in podocytes (P = 0.046) and was significantly less in proximal tubule cells (P = 0.014) in patients of group B compared with those of group A. Moreover, CD2AP expression was significantly increased in lateral tubule cells in both groups (group A, P = 0.02; group B, P = 0.001), and CatL expression in glomeruli and tubule cells did not change with the duration of CsA treatment in either patient group. CONCLUSIONS CD2AP expression in renal tubules may histologically associate with tissue hypoxia and reflected recovery from CsA-mediated renal injury in patients, even with mild histological features of tubulointerstitial disorder.
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Affiliation(s)
- Keisuke Sugimoto
- Department of Pediatrics, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-sayama, Osaka, 589-8511, Japan.
| | - Tomoki Miyazawa
- Department of Pediatrics, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-sayama, Osaka, 589-8511, Japan
| | - Takuji Enya
- Department of Pediatrics, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-sayama, Osaka, 589-8511, Japan
| | - Kouhei Miyazaki
- Department of Pediatrics, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-sayama, Osaka, 589-8511, Japan
| | - Mitsuru Okada
- Department of Pediatrics, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-sayama, Osaka, 589-8511, Japan
| | - Tsukasa Takemura
- Department of Pediatrics, Kinki University Faculty of Medicine, 377-2 Ohno-higashi, Osaka-sayama, Osaka, 589-8511, Japan
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Ogino D, Hashimoto T, Hattori M, Sugawara N, Akioka Y, Tamiya G, Makino S, Toyota K, Mitsui T, Hayasaka K. Analysis of the genes responsible for steroid-resistant nephrotic syndrome and/or focal segmental glomerulosclerosis in Japanese patients by whole-exome sequencing analysis. J Hum Genet 2015; 61:137-41. [PMID: 26467726 DOI: 10.1038/jhg.2015.122] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 09/14/2015] [Accepted: 09/15/2015] [Indexed: 12/14/2022]
Abstract
Steroid-resistant nephrotic syndrome (SRNS) represents glomerular disease resulting from a number of different etiologies leading to focal segmental glomerulosclerosis (FSGS). Recently, many genes causing SRNS/FSGS have been identified. These genes encode the proteins associated with the formation and/or maintenance of glomerular filtration barrier. Next-generation sequencing is used to analyze large numbers of genes at lower costs. To identify the genetic background of Japanese patients, we studied 26 disease-causing genes using whole-exome sequencing analysis in 24 patients with SRNS and/or FSGS from 22 different Japanese families. We finally found eight causative gene mutations, four recessive and four dominant gene mutations, including three novel mutations, in six patients from five different families, and one novel predisposing mutation in two patients from two different families. Causative gene mutations have only been identified in ~20% of families and further analysis is necessary to identify the unknown disease-causing gene. Identification of the disease-causing gene would support clinical practices, including the diagnosis, understanding of pathogenesis and treatment.
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Affiliation(s)
- Daisuke Ogino
- Department of Pediatrics, Yamagata University School of Medicine, Yamagata, Japan
| | - Taeko Hashimoto
- Department of Pediatrics, Yamagata University School of Medicine, Yamagata, Japan
| | - Motoshi Hattori
- Department of Pediatric Nephrology, Tokyo Women's Medical University, School of Medicine, Tokyo, Japan
| | - Noriko Sugawara
- Department of Pediatric Nephrology, Tokyo Women's Medical University, School of Medicine, Tokyo, Japan
| | - Yuko Akioka
- Department of Pediatric Nephrology, Tokyo Women's Medical University, School of Medicine, Tokyo, Japan
| | - Gen Tamiya
- Statistical Genetics and Genomics, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan
| | - Satoshi Makino
- Statistical Genetics and Genomics, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan
| | - Kentaro Toyota
- Department of Pediatrics, Yamagata University School of Medicine, Yamagata, Japan
| | - Tetsuo Mitsui
- Department of Pediatrics, Yamagata University School of Medicine, Yamagata, Japan
| | - Kiyoshi Hayasaka
- Department of Pediatrics, Yamagata University School of Medicine, Yamagata, Japan.,Department of Pediatrics, Miyukikai Hospital, Kaminoyma, Japan
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Ma CH, Kang LL, Ren HM, Zhang DM, Kong LD. Simiao pill ameliorates renal glomerular injury via increasing Sirt1 expression and suppressing NF-κB/NLRP3 inflammasome activation in high fructose-fed rats. JOURNAL OF ETHNOPHARMACOLOGY 2015; 172:108-117. [PMID: 26117533 DOI: 10.1016/j.jep.2015.06.015] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 05/09/2015] [Accepted: 06/11/2015] [Indexed: 06/04/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Simiao pill is one of the most frequently prescriptions in traditional Chinese medicine to treat hyperuricemia and gout. This study was to investigate the protective effects of Simiao pill on renal glomerular injury in a rat model of high fructose intake. MATERIALS AND METHODS Sprague-Dawley male rats were given 10% fructose in drinking water and standard laboratory chow for 4 weeks to induce hyperuricemia and metabolic syndrome. Then fructose-fed animals were randomly divided into four groups receiving water, Simiao pill (78.87 and 157.74 mg/kg) and allopurinol (5mg/kg) daily for next 6 weeks, respectively. Serum levels of uric acid, creatinine, triglyceride, total cholesterol, low density lipoprotein, blood urea nitrogen, insulin, as well as urinary albumin were measured. Oral glucose tolerance test (OGTT) was carried out. Kidney pathological changes were detected using periodic-acid schiff-stained (PAS) staining and transmission electron microscopy (TEM) analysis. Glomerular protein levels of nephrin, podocin, CD2-associated protein (CD2AP), interleukin (IL)-1β, sirtuin 1 (Sirt1), nuclear factor kappaB (NF-κB) and pyrin domain containing 3 (NLRP3) inflammasome were measured by Western blot. RESULTS Simiao pill effectively restored high fructose-induced hyperuricemia and metabolic syndrome in rats. Simiao pill significantly increased protein levels of nephrin, podocin and CD2AP in renal glomeruli, improved renal inflammatory cell infiltration into interstitium and glomerular injury in high fructose-fed rats with reduction of urine albumin levels. Furthermore, Simiao pill up-regulated Sirt1 protein levels and suppressed NF-κB/NLRP3 inflammasome activation to reduce IL-1β in renal glomeruli of high fructose-fed rats. CONCLUSIONS The renal protective effects of Simiao pill may be associated with up-regulation of Sirt1 expression and suppression of NF-κB/NLRP3 inflammasome activation to reduce renal glomerular injury in high fructose-fed rats with metabolic syndrome.
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Affiliation(s)
- Chun-Hua Ma
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Nanjing 210023, People's Republic of China
| | - Lin-Lin Kang
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Nanjing 210023, People's Republic of China
| | - Hong-Mei Ren
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Nanjing 210023, People's Republic of China
| | - Dong-Mei Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Nanjing 210023, People's Republic of China
| | - Ling-Dong Kong
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Nanjing 210023, People's Republic of China.
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Abstract
Alzheimer's disease (AD) represents the main form of dementia, and is a major public health problem. Despite intensive research efforts, current treatments have only marginal symptomatic benefits and there are no effective disease-modifying or preventive interventions. AD has a strong genetic component, so much research in AD has focused on identifying genetic causes and risk factors. This chapter will cover genetic discoveries in AD and their consequences in terms of improved knowledge regarding the disease and the identification of biomarkers and drug targets. First, we will discuss the study of the rare early-onset, autosomal dominant forms of AD that led to the discovery of mutations in three major genes, APP, PSEN1, and PSEN2. These discoveries have shaped our current understanding of the pathophysiology and natural history of AD as well as the development of therapeutic targets and the design of clinical trials. Then, we will explore linkage analysis and candidate gene approaches, which identified variants in Apolipoprotein E (APOE) as the major genetic risk factor for late-onset, "sporadic" forms of AD (LOAD), but failed to robustly identify other genetic risk factors, with the exception of variants in SORL1. The main focus of this chapter will be on recent genome-wide association studies that have successfully identified common genetic variations at over 20 loci associated with LOAD outside of the APOE locus. These loci are in or near-novel AD genes including BIN1, CR1, CLU, phosphatidylinositol-binding clathrin assembly protein (PICALM), CD33, EPHA1, MS4A4/MS4A6, ABCA7, CD2AP, SORL1, HLA-DRB5/DRB1, PTK2B, SLC24A4-RIN3, INPP5D, MEF2C, NME8, ZCWPW1, CELF1, FERMT2, CASS4, and TRIP4 and each has small effects on risk of AD (relative risks of 1.1-1.3). Finally, we will touch upon the ongoing effort to identify less frequent and rare variants through whole exome and whole genome sequencing. This effort has identified two novel genes, TREM2 and PLD3, and shown a role for APP in LOAD. The identification of these recently identified genes has implicated previously unsuspected biological pathways in the pathophysiology of AD.
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Affiliation(s)
- Vincent Chouraki
- Department of Neurology, Boston University School of Medicine, Boston, MA, USA; Framingham Heart Study, Framingham, MA, USA
| | - Sudha Seshadri
- Department of Neurology, Boston University School of Medicine, Boston, MA, USA; Framingham Heart Study, Framingham, MA, USA
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Bondeva T, Wolf G. Role of Neuropilin-1 in Diabetic Nephropathy. J Clin Med 2015; 4:1293-311. [PMID: 26239560 PMCID: PMC4485001 DOI: 10.3390/jcm4061293] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 05/28/2015] [Accepted: 06/09/2015] [Indexed: 02/07/2023] Open
Abstract
Diabetic nephropathy (DN) often develops in patients suffering from type 1 or type 2 diabetes mellitus. DN is characterized by renal injury resulting in proteinuria. Neuropilin-1 (NRP-1) is a single-pass transmembrane receptor protein devoid of enzymatic activity. Its large extracellular tail is structured in several domains, thereby allowing the molecule to interact with multiple ligands linking NRP-1 to different pathways through its signaling co-receptors. NRP-1’s role in nervous system development, immunity, and more recently in cancer, has been extensively investigated. Although its relation to regulation of apoptosis and cytoskeleton organization of glomerular vascular endothelial cells was reported, its function in diabetes mellitus and the development of DN is less clear. Several lines of evidence demonstrate a reduced NRP-1 expression in glycated-BSA cultured differentiated podocytes as well as in glomeruli from db/db mice (a model of type 2 Diabetes) and in diabetic patients diagnosed with DN. In vitro studies of podocytes implicated NRP-1 in the regulation of podocytes’ adhesion to extracellular matrix proteins, cytoskeleton reorganization, and apoptosis via not completely understood mechanisms. However, the exact role of NRP-1 during the onset of DN is not yet understood. This review intends to shed more light on NRP-1 and to present a link between NRP-1 and its signaling complexes in the development of DN.
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Affiliation(s)
- Tzvetanka Bondeva
- Department of Internal Medicine III, University Hospital Jena, Jena, 07747, Germany.
| | - Gunter Wolf
- Department of Internal Medicine III, University Hospital Jena, Jena, 07747, Germany.
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Yi qi qing re gao attenuates podocyte injury and inhibits vascular endothelial growth factor overexpression in puromycin aminonucleoside rat model. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2014; 2014:375986. [PMID: 24963322 PMCID: PMC4055581 DOI: 10.1155/2014/375986] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 04/24/2014] [Accepted: 04/26/2014] [Indexed: 11/18/2022]
Abstract
Proteinuria is the hallmark of chronic kidney disease. Podocyte damage underlies the formation of proteinuria, and vascular endothelial growth factor (VEGF) functions as an autocrine/paracrine regulator. Yi Qi Qing Re Gao (YQQRG) has been used to treat proteinuria for more than two decades. The objective of this study was to investigate the protective effect and possible mechanisms of YQQRG on puromycin aminonucleoside (PAN) rat model. Eighty male Sprague-Dawley rats were randomized into sham group, PAN group, PAN + YQQRG group, and PAN + fosinopril group. Treatments were started 7 days before induction of nephrosis (a single intravenous injection of 40 mg/kg PAN) until day 15. 24 h urinary samples were collected on days 5, 9, and 14. The animals were sacrificed on days 3, 10, and 15, respectively. Blood samples and renal tissues were obtained for detection of biochemical and molecular biological parameters. YQQRG significantly reduced proteinuria, elevated serum albumin, and alleviated renal pathological lesions. YQQRG inhibited VEGF-A, nephrin, podocin, and CD2AP mRNA expression and elevated nephrin, podocin, and CD2AP protein levels starting on day 3. In conclusion, YQQRG attenuates podocyte injury in the rat PAN model through downregulation of VEGF-A and restoration of nephrin, podocin, and CD2AP protein expression.
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Adair BD, Altintas MM, Möller CC, Arnaout MA, Reiser J. Structure of the kidney slit diaphragm adapter protein CD2-associated protein as determined with electron microscopy. J Am Soc Nephrol 2014; 25:1465-73. [PMID: 24511139 DOI: 10.1681/asn.2013090949] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
CD2-associated protein (CD2AP) is a multidomain scaffolding protein that has a critical role in renal function. CD2AP is expressed in glomerular podocytes at the slit diaphragm, a modified adherens junction that comprises the protein filtration barrier of the kidney, and interacts with a number of protein ligands involved in cytoskeletal remodeling, membrane trafficking, cell motility, and cell survival. The structure of CD2AP is unknown. We used electron microscopy and single particle image analysis to determine the three-dimensional structure of recombinant full-length CD2AP and found that the protein is a tetramer in solution. Image reconstruction of negatively stained protein particles generated a structure at 21 Å resolution. The protein assumed a roughly spherical, very loosely packed structure. Analysis of the electron density map revealed that CD2AP consists of a central coiled-coil domain, which forms the tetramer interface, surrounded by four symmetry-related motifs, each containing three globular domains corresponding to the three SH3 domains. The spatial organization exposes the binding sites of all 12 SH3 domains in the tetramer, allowing simultaneous binding to multiple targets. Determination of the structure of CD2AP provides novel insights into the biology of this slit diaphragm protein and lays the groundwork for characterizing the interactions between key molecules of the slit diaphragm that control glomerular filtration.
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Affiliation(s)
- Brian D Adair
- Department of Medicine, Division of Nephrology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts;
| | - Mehmet M Altintas
- Department of Medicine, Rush University Medical Center, Chicago, Illinois; and
| | - Clemens C Möller
- Department of Medicine, Division of Nephrology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - M Amin Arnaout
- Department of Medicine, Division of Nephrology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Department of Developmental and Regenerative Biology, Harvard Medical School, Boston, Massachusetts
| | - Jochen Reiser
- Department of Medicine, Rush University Medical Center, Chicago, Illinois; and
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Lv LL, Cao YH, Pan MM, Liu H, Tang RN, Ma KL, Chen PS, Liu BC. CD2AP mRNA in urinary exosome as biomarker of kidney disease. Clin Chim Acta 2013; 428:26-31. [PMID: 24144866 DOI: 10.1016/j.cca.2013.10.003] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 10/03/2013] [Indexed: 12/12/2022]
Abstract
AIMS Podocyte injury plays an important role in the pathogenesis of kidney disease. Urinary exosomes are microvesicles released by tubular epithelial cells and podocytes containing information of their originated cells. This study investigated for the first time whether podocyte related mRNA in urinary exosome could serve as novel biomarkers for kidney disease. METHODS Urine samples were collected from 32 patients of kidney disease who underwent kidney biopsy and 7 controls. CD2AP, NPHS2 and synaptopodin were detected by real-time RT-PCR on RNA isolated from urinary exosome. RESULTS The pellet microvesicles were positively stained with exosome and podocyte marker, AQP2, CD9 and nephrin. CD2AP mRNA was lower (p=0.008) in kidney disease patients compared with controls and decreased with the increasing severity of proteinuria (p=0.06). CD2AP correlated with serum creatinine (r=-0.373, p=0.035), BUN (r=-0.445, p=0.009) and eGFR (r=0.351, p=0.046). Neither NPHS2 nor synaptopodin correlated with parameters of renal function. CD2AP mRNA correlated negatively with 24 hour urine protein (r=-0.403, p=0.022), severity of tubulointerstitial fibrosis (r=-0.394, p=0.026) and glomerulosclerosis (r=-0.389, p=0.031) and could discriminate kidney disease from controls with AUC of 0.821 (p=0.008). CONCLUSIONS Urinary exosome mRNA of CD2AP might be a non-invasive tool for detecting both renal function and fibrosis of kidney disease.
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Affiliation(s)
- Lin-Li Lv
- Institute of Nephrology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China.
| | - Yu-Han Cao
- Institute of Nephrology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Ming-Ming Pan
- Institute of Nephrology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Hong Liu
- Institute of Nephrology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Ri-Ning Tang
- Institute of Nephrology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Kun-Ling Ma
- Institute of Nephrology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Ping-Sheng Chen
- Institute of Nephrology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China
| | - Bi-Cheng Liu
- Institute of Nephrology, Zhongda Hospital, School of Medicine, Southeast University, Nanjing, China.
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27
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Shulman JM, Imboywa S, Giagtzoglou N, Powers MP, Hu Y, Devenport D, Chipendo P, Chibnik LB, Diamond A, Perrimon N, Brown NH, De Jager PL, Feany MB. Functional screening in Drosophila identifies Alzheimer's disease susceptibility genes and implicates Tau-mediated mechanisms. Hum Mol Genet 2013; 23:870-7. [PMID: 24067533 DOI: 10.1093/hmg/ddt478] [Citation(s) in RCA: 165] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Using a Drosophila model of Alzheimer's disease (AD), we systematically evaluated 67 candidate genes based on AD-associated genomic loci (P < 10(-4)) from published human genome-wide association studies (GWAS). Genetic manipulation of 87 homologous fly genes was tested for modulation of neurotoxicity caused by human Tau, which forms neurofibrillary tangle pathology in AD. RNA interference (RNAi) targeting 9 genes enhanced Tau neurotoxicity, and in most cases reciprocal activation of gene expression suppressed Tau toxicity. Our screen implicates cindr, the fly ortholog of the human CD2AP AD susceptibility gene, as a modulator of Tau-mediated disease mechanisms. Importantly, we also identify the fly orthologs of FERMT2 and CELF1 as Tau modifiers, and these loci have been independently validated as AD susceptibility loci in the latest GWAS meta-analysis. Both CD2AP and FERMT2 have been previously implicated with roles in cell adhesion, and our screen additionally identifies a fly homolog of the human integrin adhesion receptors, ITGAM and ITGA9, as a modifier of Tau neurotoxicity. Our results highlight cell adhesion pathways as important in Tau toxicity and AD susceptibility and demonstrate the power of model organism genetic screens for the functional follow-up of human GWAS.
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Toyama K, Morisaki H, Cheng J, Kawachi H, Shimizu F, Ikawa M, Okabe M, Morisaki T. Proteinuria in AMPD2-deficient mice. Genes Cells 2013; 17:28-38. [PMID: 22212473 DOI: 10.1111/j.1365-2443.2011.01568.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The AMPD2 gene, a member of the AMPD gene family encoding AMP deaminase, is widely expressed in nonmuscle tissues including kidney, although its functions have not been fully elucidated. In this study, we studied the function of the AMPD2 gene by establishing AMPD2-deficient model animal. We established AMPD2 knockout mice by using gene transfer and homologous recombination in murine ES cells and studied phenotypes and functions in the kidneys of these animals. AMPD activity was decreased from 22.9 mIU/mg protein to 2.5 mIU/mg protein in the kidneys of AMPD knockout mice. In addition to changes in nucleotide metabolism in the kidneys, proteinuria was found in 3-week-old AMPD2 knockout mice, followed by a further increment up to a peak level at 6 weeks old (up to 0.6 g/dL). The major protein component in the urine of AMPD2 knockout mice was found to be albumin, indicating that AMPD2 may have a key role in glomerular filtration. Indeed, an ultrastructure study of glomerulus specimens from these mice showed effacement of the podocyte foot processes, resembling minimal-change nephropathy in humans. Based on our results, we concluded that AMPD2 deficiency induces imbalanced nucleotide metabolism and proteinuria, probably due to podocyte dysfunction.
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Affiliation(s)
- Keiko Toyama
- Department of Bioscience and Genetics, National Cerebral and Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita, Osaka 565-8565, Japan
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Progress in pathogenesis of proteinuria. Int J Nephrol 2012; 2012:314251. [PMID: 22693670 PMCID: PMC3368192 DOI: 10.1155/2012/314251] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2012] [Revised: 03/24/2012] [Accepted: 03/26/2012] [Indexed: 02/06/2023] Open
Abstract
Aims. Proteinuria not only is a sign of kidney damage, but also is involved in the progression of renal diseases as an independent pathologic factor. Clinically, glomerular proteinuria is most commonly observed, which relates to structural and functional anomalies in the glomerular filtration barrier. The aim of this paper was to describe the pathogenesis of glomerular proteinuria. Data Sources. Articles on glomerular proteinuria retrieved from Pubmed and MEDLINE in the recent 5 years were reviewed. Results. The new understanding of the roles of glomerular endothelial cells and the glomerular basement membrane (GBM) in the pathogenesis of glomerular proteinuria was gained. The close relationships of slit diaphragm (SD) molecules such as nephrin, podocin, CD2-associated protein (CD2AP), a-actinin-4, transient receptor potential cation channel 6 (TRPC6), Densin and membrane-associated guanylate kinase inverted 1 (MAGI-1), α3β1 integrin, WT1, phospholipase C epsilon-1 (PLCE1), Lmx1b, and MYH9, and mitochondrial disorders and circulating factors in the pathogenesis of glomerular proteinuria were also gradually discovered. Conclusion. Renal proteinuria is a manifestation of glomerular filtration barrier dysfunction. Not only glomerular endothelial cells and GBM, but also the glomerular podocytes and their SDs play an important role in the pathogenesis of glomerular proteinuria.
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Gigante M, Piemontese M, Gesualdo L, Iolascon A, Aucella F. Molecular and genetic basis of inherited nephrotic syndrome. Int J Nephrol 2011; 2011:792195. [PMID: 21904677 PMCID: PMC3167185 DOI: 10.4061/2011/792195] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Revised: 06/16/2011] [Accepted: 06/16/2011] [Indexed: 12/26/2022] Open
Abstract
Nephrotic syndrome is an heterogeneous disease characterized by increased permeability of the glomerular filtration barrier for macromolecules. Podocytes, the visceral epithelial cells of glomerulus, play critical role in ultrafiltration of plasma and are involved in a wide number of inherited and acquired glomerular diseases. The identification of mutations in nephrin and other podocyte genes as causes of genetic forms of nephrotic syndrome has revealed new important aspects of the pathogenesis of proteinuric kidney diseases and expanded our knowledge of the glomerular biology. Moreover, a novel concept of a highly dynamic slit diaphragm proteins is emerging. The most significant discoveries in our understanding of the structure and function of the glomerular filtration barrier are reviewed in this paper.
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Affiliation(s)
- Maddalena Gigante
- Division of Nephrology, Department of Biomedical Science, University of Foggia, 71121 Foggia, Italy
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Gbadegesin R, Lavin P, Foreman J, Winn M. Pathogenesis and therapy of focal segmental glomerulosclerosis: an update. Pediatr Nephrol 2011; 26:1001-15. [PMID: 21110043 PMCID: PMC3624015 DOI: 10.1007/s00467-010-1692-x] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Revised: 09/28/2010] [Accepted: 10/04/2010] [Indexed: 02/07/2023]
Abstract
Focal and segmental glomerulosclerosis (FSGS) is an important cause of steroid-resistant nephrotic syndrome in adults and children. It is responsible for 5-20% of all cases of end-stage kidney disease (ESKD) in the United States. The pathogenesis of FSGS has not been fully elucidated; however, data from molecular studies of familial cases in the last two decades suggest that FSGS is a defect of the podocyte. The therapeutic agents available for treatment of FSGS are not very effective and only a small percentage of affected individuals will achieve complete remission. Recent data from molecular biology and molecular genetics has provided insight into the mechanisms of action of old agents and also identification of other novel therapeutic targets. This review focuses on recent advances in the molecular pathogenesis of FSGS and currently available therapeutic agents as well as potential novel therapies.
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Affiliation(s)
- Rasheed Gbadegesin
- Department of Pediatrics, Duke University Medical Center, Durham, NC 27710, USA.
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Cheng H, Harris RC. The glomerulus--a view from the outside--the podocyte. Int J Biochem Cell Biol 2010; 42:1380-7. [PMID: 20542138 DOI: 10.1016/j.biocel.2010.05.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 04/12/2010] [Accepted: 05/30/2010] [Indexed: 01/11/2023]
Abstract
In the past decade, podocyte research has been greatly aided by the development of powerful new molecular, cellular and animal tools, leading to elucidation of an increasing number of proteins involved in podocyte function and identification of mutated genes in hereditary glomerulopathies. Accumulating evidence indicates that podocyte disorders may not only underlie these hereditary glomerulopathies but also play crucial role in a broad spectrum of acquired glomerular diseases. Genetic susceptibility, environmental influence and systemic responses are all involved in the mediation of the pathogenesis of podocytopathies. Injured podocytes may predisopose to further injury of other podocytes and other adjacent/distant renal cells in a vicious cycle, leading to inexorable progression of glomerular injury. The classic view is that podocytes have a limited ability to proliferate in the normal mature kidney. However, recent research in rodents has provided suggestive evidence for podocyte regeneration resulting from differentiation of progenitor cells within Bowman's capsule.
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Affiliation(s)
- Huifang Cheng
- Division of Nephrology, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232-2372, USA.
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Murakami A, Oshiro H, Kanzaki S, Yamaguchi A, Yamanaka S, Furuya M, Miura S, Kanno H, Nagashima Y, Aoki I, Nagahama K. A novel method for isolating podocytes using magnetic activated cell sorting. Nephrol Dial Transplant 2010; 25:3884-90. [PMID: 20530496 DOI: 10.1093/ndt/gfq323] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND A large body of accumulated data has now revealed that podocytes play a major role in the development of proteinuria. However, the mechanisms of podocyte injury, leading to foot process effacement and proteinuria, are still unclear partly due to the current lack of an appropriate strategy for preparing podocytes. In this study, we have developed a novel method of rapid isolation of podocytes from mice using magnetic activated cell sorting with an anti-nephrin antibody. METHODS After endothelial cell depletion using anti-CD31 antibody, nephrin-positive cells were prepared from mouse kidneys using magnetic activated cell sorting with polyclonal rabbit anti-nephrin antibody. Purity of the positively sorted cells was determined by confocal microscopy and fluorescence-activated cell sorting (FACS) analysis. Expression profiles of podocyte-specific molecules in the sorted fractions were characterized by qualitative PCR and immunoblot analysis. RESULTS Nephrin-positive cells, isolated from mouse kidneys within 6 h, showed dual positivity for synaptopodin and rabbit IgG on confocal microscopy. FACS analysis revealed that the purity of the positively sorted fractions was ∼75%. The nephrin-positive cells sorted by this approach showed a significantly higher expression of podocyte-specific molecules compared with nephrin-negative fractions. CONCLUSIONS These data strongly suggest that our novel method for isolating podocytes has great utility for various downstream applications such as genomic analysis, proteomics and transcriptomics to elucidate molecular profiling of podocyte biology in vivo compared with conventional methods as our approach requires only several hours to complete and no tissue culture.
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Affiliation(s)
- Ayumi Murakami
- Department of Pathology, Yokohama City University School of Medicine 3-9 Fukuura, Kanazawa-ku, Yokohama 236-0004, Japan
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van Duijn TJ, Anthony EC, Hensbergen PJ, Deelder AM, Hordijk PL. Rac1 recruits the adapter protein CMS/CD2AP to cell-cell contacts. J Biol Chem 2010; 285:20137-46. [PMID: 20404345 DOI: 10.1074/jbc.m109.099481] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Rac1 is a member of the Rho family of small GTPases, which regulate cell adhesion and migration through their control of the actin cytoskeleton. Rho-GTPases are structurally very similar, with the exception of a hypervariable domain in the C terminus. Using peptide-based pulldown assays in combination with mass spectrometry, we previously showed that the hypervariable domain in Rac1 mediates specific protein-protein interactions. Most recently, we found that the Rac1 C terminus associates to the ubiquitously expressed adapter protein CMS/CD2AP. CD2AP is critical for the formation and maintenance of a specialized cell-cell contact between kidney podocyte foot processes, the slit diaphragm. Here, CD2AP links the cell adhesion protein nephrin to the actin cytoskeleton. In addition, CMS/CD2AP binds actin-regulating proteins, such as CAPZ and cortactin, and has been implicated in the internalization of growth factor receptors. We found that CD2AP specifically interacts with the C-terminal domain of Rac1 but not with that of other Rho family members. Efficient interaction between Rac1 and CD2AP requires both the proline-rich domain and the poly-basic region in the Rac1 C terminus, and at least two of the three N-terminal SH3 domains of CD2AP. CD2AP co-localizes with Rac1 to membrane ruffles, and small interfering RNA-based experiments showed that CD2AP links Rac1 to CAPZ and cortactin. Finally, expression of constitutive active Rac1 recruits CD2AP to cell-cell contacts in epithelial cells, where we found CD2AP to participate in the control of the epithelial barrier function. These data identify CD2AP as a novel Rac1-associated adapter protein that participates in the regulation of epithelial cell-cell contact.
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Affiliation(s)
- Trynette J van Duijn
- Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, University of Amsterdam, 1066 CX, Amsterdam
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Magistroni R, Ligabue G, Lupo V, Furci L, Leonelli M, Manganelli L, Masellis M, Gatti V, Cavazzini F, Tizzanini W, Albertazzi A. Proteomic analysis of urine from proteinuric patients shows a proteolitic activity directed against albumin. Nephrol Dial Transplant 2009; 24:1672-81. [PMID: 19211645 DOI: 10.1093/ndt/gfp020] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Nephrotic syndrome is a condition that is clinically associated with poor outcome. In this study, we compared different techniques of urine sample preparation in order to develop a robust analytical protocol to define the differential urinary proteome of urinary abnormalities compared to nephrotic proteinuria. METHODS We recruited 5 normal control subjects, 16 patients with urinary abnormalities and 16 patients with nephrotic syndrome. Proteins from normal urine were processed using three different protocols [acetone, ultrafiltration and trichloroacetic acid (TCA) precipitation], depletion of albumin and IgGs and then analysed by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) gels and mass spectrometry. RESULTS Comparing the three extraction methods by visual inspection of gels after 2D gel electrophoresis, the acetone precipitation and TCA methods yielded the best quality of protein extraction, while the acetone precipitation method was the most efficient. Furthermore, we tested three commercial kits for albumin and IgG depletion. We applied the optimized acetone extraction protocol to compare urinary samples from nephrotic patients (NP) to urinary samples obtained from patients presenting with urinary abnormalities (UAP). We observed a proteolytic activity directed against albumin. This observation was more prevalent in urinary samples from NP than from UAP. Within both groups, there was some inter-individual variability in the observed proteolytic activity. An increased concentration of alpha1 antitrypsin was also observed in urine of NP. We analysed albumin fragmentation by 1D and 2D western blots in the same samples skipping the albumin and IgG depletion steps to avoid the possible confound of albumin fragment removal. The analysis confirmed a stronger proteolytic activity in the nephrotic group. CONCLUSIONS The proteolytic activity against albumin and the anti-proteolytic activity of alpha1 antitrypsin are likely linked and could play an important role in the nephrotic process. If replicated in larger samples, this methodology may lead to a better understanding of the underlying pathophysiological process of nephrotic syndrome.
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Affiliation(s)
- Riccardo Magistroni
- Division of Nephrology Dialisys and Transplantation, Dipartimento Integrato Medicine e Specialità Mediche, Universià di Modena e Reggio Emilia, via del Pozzo 71 41100 Modena, Italy.
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Lu C, Ren W, Su XM, Chen JQ, Wu SH, Zhou GP. EGF-recruited JunD/c-fos complexes activate CD2AP gene promoter and suppress apoptosis in renal tubular epithelial cells. Gene 2008; 433:56-64. [PMID: 19095050 DOI: 10.1016/j.gene.2008.11.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 10/21/2008] [Accepted: 11/13/2008] [Indexed: 10/24/2022]
Abstract
CD2-associated protein (CD2AP) plays a critical role in the maintenance of the kidney filtration barrier. In this study, we showed that epidermal growth factor (EGF) led to an increase of the CD2AP protein and mRNA in the human renal proximal tubular epithelial cell line HK-2 cells, which was due to the elevation of CD2AP promoter activity. Upon deletion and mutation analysis, electrophoretic mobility shift assays and chromatin immunoprecipitation, an AP-1-like element within CD2AP promoter was characterized, by which EGF recruited c-fos and JunD, two components of AP-1, to the human CD2AP gene promoter and suppressed angiotensin II-induced apoptosis in HK-2 cells. Specific siRNA was synthesized to knock down the human CD2AP gene in HK-2 cells. We found that CD2AP deficiency attenuated the inhibitory effects of EGF and predisposed the renal tubular epithelial cells to undergo angiotensin II-induced apoptosis. Furthermore, EGF-induced increases of CD2AP protein and mRNA expressions in HK-2 cells were significantly inhibited by the transfection of dominant negative JunD or c-fos vector, which was in parallel with a marked reduction of antiapoptotic effect of EGF. These results indicated that the antiapoptotic effect of EGF/CD2AP signal transduction was mediated by JunD and c-fos, at least partially. This study defined a new EGF/AP-1/CD2AP mediated cell-survival signaling, which might be useful to clarify the molecular mechanisms responsible for CD2AP associated kidney diseases.
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Affiliation(s)
- Chao Lu
- Department of Pediatrics, the First Affiliated Hospital of Nanjing Medical University, Jiangsu, People's Republic of China
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Bredemeyer AJ, Geahlen JH, Weis VG, Huh WJ, Zinselmeyer BH, Srivatsan S, Miller MJ, Shaw AS, Mills JC. The gastric epithelial progenitor cell niche and differentiation of the zymogenic (chief) cell lineage. Dev Biol 2008; 325:211-24. [PMID: 19013146 DOI: 10.1016/j.ydbio.2008.10.025] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Revised: 09/19/2008] [Accepted: 10/13/2008] [Indexed: 12/16/2022]
Abstract
In the mammalian gastrointestinal tract, the cell fate decisions that specify the development of multiple, diverse lineages are governed in large part by interactions of stem and early lineage progenitor cells with their microenvironment, or niche. Here, we show that the gastric parietal cell (PC) is a key cellular component of the previously undescribed niche for the gastric epithelial neck cell, the progenitor of the digestive enzyme secreting zymogenic (chief) cell (ZC). Genetic ablation of PCs led to failed patterning of the entire zymogenic lineage: progenitors showed premature expression of differentiated cell markers, and fully differentiated ZCs failed to develop. We developed a separate mouse model in which PCs localized not only to the progenitor niche, but also ectopically to the gastric unit base, which is normally occupied by terminally differentiated ZCs. Surprisingly, these mislocalized PCs did not maintain adjacent zymogenic lineage cells in the progenitor state, demonstrating that PCs, though necessary, are not sufficient to define the progenitor niche. We induced this PC mislocalization by knocking out the cytoskeleton-regulating gene Cd2ap in Mist1(-/-) mice, which led to aberrant E-cadherin localization in ZCs, irregular ZC-ZC junctions, and disruption of the ZC monolayer by PCs. Thus, the characteristic histology of the gastric unit, with PCs in the middle and ZCs in the base, may depend on establishment of an ordered adherens junction network in ZCs as they migrate into the base.
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Affiliation(s)
- Andrew J Bredemeyer
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110, USA
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Ijpelaar DHT, Schulz A, Aben J, van der Wal A, Bruijn JA, Kreutz R, de Heer E. Genetic predisposition for glomerulonephritis-induced glomerulosclerosis in rats is linked to chromosome 1. Physiol Genomics 2008; 35:173-81. [PMID: 18682577 DOI: 10.1152/physiolgenomics.00268.2007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Genetic factors influence renal disease progression, and several loci have been linked to the spontaneous development of proteinuria and glomerulosclerosis in animal models. However, the role of genetic susceptibility in glomerulonephritis-induced progressive glomerulosclerosis is unknown. In a rat model of mesangial proliferative glomerulonephritis, anti-Thy-1 glomerulonephritis (antiThy1GN), Lewis/Maastricht (Lew/Maa) rats exhibit progression to glomerulosclerosis, whereas in genetically related Lewis/Møllegard (Lew/Moll) rats, glomerular lesions are repaired within 3 wk. The genetic factors underlying this strain-related difference are not known. To identify novel quantitative trait loci (QTL) involved in progression or repair in Lewis rats, 145 female backcross rats [F1(Lew/Maa x Lew/Moll) x Lew/Maa] were studied. After induction of antiThy1GN proteinuria, we determined mesangial activation, the percentage of microaneurysms, and the glomerular damage score for each animal; a genome scan using 187 microsatellite markers was performed. QTL mapping revealed a significant QTL for glomerular damage score on chromosome 1 with a logarithm of odds (LOD) score of 3.9. Homozygosity for Lew/Maa DNA in this region was associated with a higher percentage of damaged glomeruli on day 21. Furthermore, suggestive linkage was found for the percentage of glomeruli with microaneurysms on day 3 on chromosome 1, 6, and 11; for mesangial activation on day 7 on chromosome 18, while proteinuria was suggestively linked to chromosome 5 (day 0), 4 (day 3), and 6 (day 7). This study identifies a QTL on rat chromosome 1 that is significantly linked to progressive glomerulosclerosis after acute glomerulonephritis.
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Haraldsson B, Nyström J, Deen WM. Properties of the Glomerular Barrier and Mechanisms of Proteinuria. Physiol Rev 2008; 88:451-87. [DOI: 10.1152/physrev.00055.2006] [Citation(s) in RCA: 611] [Impact Index Per Article: 38.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
This review focuses on the intricate properties of the glomerular barrier. Other reviews have focused on podocyte biology, mesangial cells, and the glomerular basement membrane (GBM). However, since all components of the glomerular membrane are important for its function, proteinuria will occur regardless of which layer is affected by disease. We review the properties of endothelial cells and their surface layer, the GBM, and podocytes, discuss various methods of studying glomerular permeability, and analyze data concerning the restriction of solutes by size, charge, and shape. We also review the physical principles of transport across biological or artificial membranes and various theoretical models used to predict the fluxes of solutes and water. The glomerular barrier is highly size and charge selective, in qualitative agreement with the classical studies performed 30 years ago. The small amounts of albumin filtered will be reabsorbed by the megalin-cubulin complex and degraded by the proximal tubular cells. At present, there is no unequivocal evidence for reuptake of intact albumin from urine. The cellular components are the key players in restricting solute transport, while the GBM is responsible for most of the resistance to water flow across the glomerular barrier.
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Lu C, Ren W, Su XM, Chen JQ, Wu SH, Guo XR, Huang SM, Chen LH, Zhou GP. CREB and Sp1 regulate the human CD2AP gene promoter activity in renal tubular epithelial cells. Arch Biochem Biophys 2008; 474:143-9. [PMID: 18396147 DOI: 10.1016/j.abb.2008.03.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2008] [Accepted: 03/24/2008] [Indexed: 11/28/2022]
Abstract
The human CD2-associated protein (CD2AP) is involved in several molecular signaling pathways and is an important factor responsible for nephrotic syndrome. Here we report the identification of the transcription start point and promoter region of the human CD2AP gene in renal tubular epithelial cells. With luciferase assays and deletion analysis, we found that the region between -558 and -1bp ahead of the transcription start point is indispensable for the promoter activity of the human CD2AP gene. A CREB site and two Sp1 sites were essential for maintaining the basal transcriptional activity of the human CD2AP promoter. Overexpression of phosphorylated CREB and Sp1 transactivated the human CD2AP promoter, whereas small interfering RNA-mediated blockage of CREB and Sp1 genes expressions inhibited markedly its activity. These findings provide the first analysis of the human CD2AP gene promoter and demonstrate that not only CREB but also Sp1 plays a critical role in regulating basal CD2AP promoter activity in renal tubular epithelial cells.
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Affiliation(s)
- Chao Lu
- Department of Pediatrics, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu 210029, People's Republic of China
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Ciechanowicz A, Brodkiewicz A, Bińczak-Kuleta A, Parczewski M, Czekalski S. “Treasure your exceptions”: recent advances in molecular genetics of glomerular disease. J Appl Genet 2008; 49:93-9. [DOI: 10.1007/bf03195253] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Cho HY, Lee JH, Choi HJ, Lee BH, Ha IS, Choi Y, Cheong HI. WT1 and NPHS2 mutations in Korean children with steroid-resistant nephrotic syndrome. Pediatr Nephrol 2008; 23:63-70. [PMID: 17934764 DOI: 10.1007/s00467-007-0620-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2007] [Revised: 07/25/2007] [Accepted: 08/14/2007] [Indexed: 01/15/2023]
Abstract
Although several genetic causes of steroid-resistant nephrotic syndrome (SRNS) have been identified, occurrence of these genetic abnormalities appears to be influenced by race. Seventy Korean children (39 girls, 31 boys) with SRNS underwent analysis for mutations of WT1 and NPHS2. Although NPHS2 mutations were not present in any of the patients, two different intronic mutations of WT1, IVS9+4 C>T and IVS9+5 G>A, were detected in four patients (three girls, one boy). Among the four patients with mutation, two girls with a karyotype of 46,XY had complete XY gonadal dysgenesis, one girl with a karyotype of 46,XX had normal genitalia, and one boy with a karyotype of 46,XY had hypospadia. A kidney biopsy conducted in three of the four patients revealed focal segmental glomerulosclerosis. The incidence of WT1 mutations observed in this study was similar to that of previous reports. However, the incidence of NPHS2 mutations seems to be very rare in Korean children. Genetic diagnosis of WT1 mutations should be recommended for children with SRNS, especially in cases involving a female phenotype or males with genital anomalies.
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Affiliation(s)
- Hee Yeon Cho
- Department of Pediatrics, Seoul National University Children's Hospital, 28 Yongon-Dong Chongro-Gu, Seoul 110-744, South Korea
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Ortega Roldan JL, Romero Romero ML, Ora A, Ab E, Lopez Mayorga O, Azuaga AI, van Nuland NAJ. The high resolution NMR structure of the third SH3 domain of CD2AP. JOURNAL OF BIOMOLECULAR NMR 2007; 39:331-336. [PMID: 17922258 DOI: 10.1007/s10858-007-9201-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2007] [Accepted: 09/14/2007] [Indexed: 05/25/2023]
Abstract
CD2 associated protein (CD2AP) is an adaptor protein that plays an important role in cell to cell union needed for the kidney function. CD2AP interacts, as an adaptor protein, with different natural targets, such as CD2, nefrin, c-Cbl and podocin. These proteins are believed to interact to one of the three SH3 domains that are positioned in the N-terminal region of CD2AP. To understand the network of interactions between the natural targets and the three SH3 domains (SH3-A, B and C), we have started to determine the structures of the individual SH3 domains. Here we present the high-resolution structure of the SH3-C domain derived from NMR data. Full backbone and side-chain assignments were obtained from triple-resonance spectra. The structure was determined from distance restraints derived from high-resolution 600 and 800 MHz NOESY spectra, together with phi and psi torsion angle restraints based on the analysis of 1HN, 15N, 1Halpha, 13Calpha, 13CO and 13Cbeta chemical shifts. Structures were calculated using CYANA and refined in water using RECOORD. The three-dimensional structure of CD2AP SH3-C contains all the features that are typically found in other SH3 domains, including the general binding site for the recognition of polyproline sequences.
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Affiliation(s)
- Jose L Ortega Roldan
- Departamento de Química Física e Instituto de Biotecnología, Facultad de Ciencias, Universidad de Granada, Campus Fuentenueva s/n, Granada 18071, Spain
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Morita E, Sandrin V, Chung HY, Morham SG, Gygi SP, Rodesch CK, Sundquist WI. Human ESCRT and ALIX proteins interact with proteins of the midbody and function in cytokinesis. EMBO J 2007; 26:4215-27. [PMID: 17853893 PMCID: PMC2230844 DOI: 10.1038/sj.emboj.7601850] [Citation(s) in RCA: 537] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2007] [Accepted: 08/15/2007] [Indexed: 12/12/2022] Open
Abstract
TSG101 and ALIX both function in HIV budding and in vesicle formation at the multivesicular body (MVB), where they interact with other Endosomal Sorting Complex Required for Transport (ESCRT) pathway factors required for release of viruses and vesicles. Proteomic analyses revealed that ALIX and TSG101/ESCRT-I also bind a series of proteins involved in cytokinesis, including CEP55, CD2AP, ROCK1, and IQGAP1. ALIX and TSG101 concentrate at centrosomes and are then recruited to the midbodies of dividing cells through direct interactions between the central CEP55 'hinge' region and GPP-based motifs within TSG101 and ALIX. ESCRT-III and VPS4 proteins are also recruited, indicating that much of the ESCRT pathway localizes to the midbody. Depletion of ALIX and TSG101/ESCRT-I inhibits the abscission step of HeLa cell cytokinesis, as does VPS4 overexpression, confirming a requirement for these proteins in cell division. Furthermore, ALIX point mutants that block CEP55 and CHMP4/ESCRT-III binding also inhibit abscission, indicating that both interactions are essential. These experiments suggest that the ESCRT pathway may be recruited to facilitate analogous membrane fission events during HIV budding, MVB vesicle formation, and the abscission stage of cytokinesis.
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Affiliation(s)
- Eiji Morita
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - Virginie Sandrin
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | - Hyo-Young Chung
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
| | | | - Steven P Gygi
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Christopher K Rodesch
- School of Medicine Fluorescence Microscopy Core Facility, University of Utah, Salt Lake City, UT, USA
| | - Wesley I Sundquist
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
- Department of Biochemistry, University of Utah, room 4100, 15N Medical Dr East, Salt Lake City, UT 84132-3201, USA. Tel.: +1 801 585 5402; Fax: +1 801 581 7959; E-mail:
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Abstract
Increasing evidence from a variety of cell types has highlighted the importance of the actin cytoskeleton during endocytosis. No longer is actin viewed as a passive barrier that must be removed to allow endocytosis to proceed. Rather, actin structures are dynamically organised to assist the remodelling of the cell surface to allow inward movement of vesicles. The majority of our mechanistic insight into the role of actin in endocytosis has come from studies in budding yeast. Although endocytosis in mammalian cells is clearly more complex and subject to a greater array of regulatory signals, recent advances have revealed actin, and actin-regulatory proteins, to be present at endocytic sites. Furthermore, live cell imaging indicates that spatiotemporal aspects of actin recruitment and vesicle formation are likely to be conserved across eukaryotic evolution.
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Affiliation(s)
- Elizabeth Smythe
- Department of Biomedical Science, Firth Court, Western Bank, University of Sheffield, Sheffield, UK
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Dandapani SV, Sugimoto H, Matthews BD, Kolb RJ, Sinha S, Gerszten RE, Zhou J, Ingber DE, Kalluri R, Pollak MR. α-Actinin-4 Is Required for Normal Podocyte Adhesion. J Biol Chem 2007; 282:467-77. [PMID: 17082197 DOI: 10.1074/jbc.m605024200] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mutations in the alpha-actinin-4 gene ACTN4 cause an autosomal dominant human kidney disease. Mice deficient in alpha-actinin-4 develop a recessive phenotype characterized by kidney failure, proteinuria, glomerulosclerosis, and retraction of glomerular podocyte foot processes. However, the mechanism by which alpha-actinin-4 deficiency leads to glomerular disease has not been defined. Here, we examined the effect of alpha-actinin-4 deficiency on the adhesive properties of podocytes in vivo and in a cell culture system. In alpha-actinin-4-deficient mice, we observed a decrease in the number of podocytes per glomerulus compared with wild-type mice as well as the presence of podocyte markers in the urine. Podocyte cell lines generated from alpha-actinin-4-deficient mice were less adherent than wild-type cells to glomerular basement membrane (GBM) components collagen IV and laminin 10 and 11. We also observed markedly reduced adhesion of alpha-actinin-4-deficient podocytes under increasing shear stresses. This adhesion deficit was restored by transfecting cells with alpha-actinin-4-GFP. We tested the strength of the integrin receptor-mediated linkages to the cytoskeleton by applying force to microbeads bound to integrin using magnetic pulling cytometry. Beads bound to alpha-actinin-4-deficient podocytes showed greater displacement in response to an applied force than those bound to wild-type cells. Consistent with integrin-dependent alpha-actinin-4-mediated adhesion, phosphorylation of beta1-integrins on alpha-actinin-4-deficient podocytes is reduced. We rescued the phosphorylation deficit by transfecting alpha-actinin-4 into alpha-actinin-4-deficient podocytes. These results suggest that alpha-actinin-4 interacts with integrins and strengthens the podocyte-GBM interaction thereby stabilizing glomerular architecture and preventing disease.
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Affiliation(s)
- Savita V Dandapani
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
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Chen CA, Hwang JC, Guh JY, Chang JM, Lai YH, Chen HC. Reduced podocyte expression of alpha3beta1 integrins and podocyte depletion in patients with primary focal segmental glomerulosclerosis and chronic PAN-treated rats. ACTA ACUST UNITED AC 2006; 147:74-82. [PMID: 16459165 DOI: 10.1016/j.lab.2005.08.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2005] [Revised: 08/12/2005] [Accepted: 08/13/2005] [Indexed: 11/29/2022]
Abstract
Integrins attach cells to extracellular matrix (ECM) and mediate signals from ECM to cells or from cells to ECM. They regulate cell functions, including adhesion, migration, cell cycle regulation, and differentiation. Podocytes may detach from the glomerular basement membrane (GBM) and be excreted in the urine, and proteinuria is found in patients with primary focal segmental glomerulosclerosis (FSGS); both may be associated with loss of alpha3beta1integrins. In this study, we have examined the podocyte number in patients with primary FSGS and normal controls, and the alpha3- and beta1-integrin subunits expression of podocytes in patients with primary FSGS and chronic puromycin aminonucleoside (PAN)-treated rats by the morphometric, immunoperoxidase histochemical, and immunoelectron microscopic examination. We also measured their expression serially in rats that received repeated PAN injection. The results showed that the podocyte number was significantly decreased in patients with primary FSGS than in normal control (P < 0.05). The immunostaining score showed that both alpha3- and beta1-integrin subunits on podocytes in patients with primary FSGS were significantly lower than in normal controls (both P < 0.01). The number of immuno-gold particles of alpha3- and beta1-integrins at the effaced foot process area of patients with primary FSGS were also significantly decreased than that of normal controls (both P < 0.05). The immunostaining score of both alpha3- and beta1-integrin subunits was negatively correlated with the degree of glomerular sclerosing score and the amount of daily protein loss, and they were positively correlated with the number of podocytes. Chronic 12-week PAN-treated rats showed similar findings with decreased immunostaining expression and immuno-gold particles of alpha3-integrin on podocytes than in normal control (both P < 0.05). The chronic PAN-treated rats also showed a trend toward gradually decreased immunostaining expression of alpha3-integrin subunit on podocyte during the progress from normal to FSGS state. These studies indicate that podocyte expression of alpha3- and beta1-integrin subunits is significantly reduced in humans with primary FSGS and chronic PAN-treated rats, before the morphological changes of FSGS are observed. The decreased podocyte expression of alpha3beta1 integrins is closely related with podocyte depletion, glomerular sclerosis, and daily protein loss in patients with primary FSGS.
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Affiliation(s)
- Chien-An Chen
- Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
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Kramer-Zucker AG, Wiessner S, Jensen AM, Drummond IA. Organization of the pronephric filtration apparatus in zebrafish requires Nephrin, Podocin and the FERM domain protein Mosaic eyes. Dev Biol 2006; 285:316-29. [PMID: 16102746 PMCID: PMC2836015 DOI: 10.1016/j.ydbio.2005.06.038] [Citation(s) in RCA: 180] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2005] [Revised: 05/24/2005] [Accepted: 06/17/2005] [Indexed: 02/07/2023]
Abstract
Podocytes are specialized cells of the kidney that form the blood filtration barrier in the kidney glomerulus. The barrier function of podocytes depends upon the development of specialized cell-cell adhesion complexes called slit-diaphragms that form between podocyte foot processes surrounding glomerular blood vessels. Failure of the slit-diaphragm to form results in leakage of high molecular weight proteins into the blood filtrate and urine, a condition called proteinuria. In this work, we test whether the zebrafish pronephros can be used as an assay system for the development of glomerular function with the goal of identifying novel components of the slit-diaphragm. We first characterized the function of the zebrafish homolog of Nephrin, the disease gene associated with the congenital nephritic syndrome of the Finnish type, and Podocin, the gene mutated in autosomal recessive steroid-resistant nephrotic syndrome. Zebrafish nephrin and podocin were specifically expressed in pronephric podocytes and required for the development of pronephric podocyte cell structure. Ultrastructurally, disruption of nephrin or podocin expression resulted in a loss of slit-diaphragms at 72 and 96 h post-fertilization and failure to form normal podocyte foot processes. We also find that expression of the band 4.1/FERM domain gene mosaic eyes in podocytes is required for proper formation of slit-diaphragm cell-cell junctions. A functional assay of glomerular filtration barrier revealed that absence of normal nephrin, podocin or mosaic eyes expression results in loss of glomerular filtration discrimination and aberrant passage of high molecular weight substances into the glomerular filtrate.
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Affiliation(s)
| | - Stephanie Wiessner
- Renal Unit, Massachusetts General Hospital 149-8000, 149 13th Street, Charlestown, MA 02129, USA
| | - Abbie M. Jensen
- Biology Department, 221 Morrill South, University of Massachusetts, Amherst, MA 01003, USA
| | - Iain A. Drummond
- Renal Unit, Massachusetts General Hospital 149-8000, 149 13th Street, Charlestown, MA 02129, USA
- Corresponding author. Fax: +1 617 726 5669. (I.A. Drummond)
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