1
|
Yang Z, Chen L, Huang Y, Dong J, Yan Q, Li Y, Qiu J, Li H, Zhao D, Liu F, Tang D, Dai Y. Proteomic profiling of laser capture microdissection kidneys from diabetic nephropathy patients. J Chromatogr B Analyt Technol Biomed Life Sci 2024; 1243:124231. [PMID: 38996754 DOI: 10.1016/j.jchromb.2024.124231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Revised: 05/23/2024] [Accepted: 07/01/2024] [Indexed: 07/14/2024]
Abstract
Diabetic nephropathy (DN) remains the primary cause of end-stage renal disease (ESRD), warranting equal attention and separate analysis of glomerular, tubular, and interstitial lesions in its diagnosis and intervention. This study aims to identify the specific proteomics characteristics of DN, and assess changes in the biological processes associated with DN. 5 patients with DN and 5 healthy kidney transplant donor control individuals were selected for analysis. The proteomic characteristics of glomeruli, renal tubules, and renal interstitial tissue obtained through laser capture microscopy (LCM) were studied using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Significantly, the expression of multiple heat shock proteins (HSPs), tubulins, and heterogeneous nuclear ribonucleoproteins (hnRNPs) in glomeruli and tubules was significantly reduced. Differentially expressed proteins (DEPs) in the glomerulus showed significant enrichment in pathways related to cell junctions and cell movement, including the regulation of actin cytoskeleton and tight junction. DEPs in renal tubules were significantly enriched in glucose metabolism-related pathways, such as glucose metabolism, glycolysis/gluconeogenesis, and the citric acid cycle. Moreover, the glycolysis/gluconeogenesis pathway was a co-enrichment pathway in both DN glomeruli and tubules. Notably, ACTB emerged as the most crucial protein in the protein-protein interaction (PPI) analysis of DEPs in both glomeruli and renal tubules. In this study, we delve into the unique proteomic characteristics of each sub-region of renal tissue. This enhances our understanding of the potential pathophysiological changes in DN, particularly the potential involvement of glycolysis metabolic disorder, glomerular cytoskeleton and cell junctions. These insights are crucial for further research into the identification of disease biomarkers and the pathogenesis of DN.
Collapse
Affiliation(s)
- Zhiqian Yang
- Guangdong Provincial Engineering Research Center of Autoimmune Disease Precision Medicine, Shenzhen Engineering Research Center of Autoimmune Disease, Shenzhen Clinical Research Center for Geriatrics, Shenzhen People' s Hospital, The Second Clinical Medical College, Jinan University, Shenzhen 518020, China; Department of Nephrology, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou 510632, China
| | - Liangmei Chen
- Department of Nephrology, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou 510632, China
| | - Yingxin Huang
- Department of Nephrology, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou 510632, China; Department of Nephrology, Xiaolan People's Hospital of Zhongshan, 528400, China
| | - Jingjing Dong
- Guangdong Provincial Engineering Research Center of Autoimmune Disease Precision Medicine, Shenzhen Engineering Research Center of Autoimmune Disease, Shenzhen Clinical Research Center for Geriatrics, Shenzhen People' s Hospital, The Second Clinical Medical College, Jinan University, Shenzhen 518020, China; Department of Nephrology, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou 510632, China
| | - Qiang Yan
- Department of Organ Transplantation, 924 Hospital, Guilin 541002, China
| | - Ya Li
- Guangdong Provincial Engineering Research Center of Autoimmune Disease Precision Medicine, Shenzhen Engineering Research Center of Autoimmune Disease, Shenzhen Clinical Research Center for Geriatrics, Shenzhen People' s Hospital, The Second Clinical Medical College, Jinan University, Shenzhen 518020, China
| | - Jing Qiu
- Guangdong Provincial Engineering Research Center of Autoimmune Disease Precision Medicine, Shenzhen Engineering Research Center of Autoimmune Disease, Shenzhen Clinical Research Center for Geriatrics, Shenzhen People' s Hospital, The Second Clinical Medical College, Jinan University, Shenzhen 518020, China
| | - Haitao Li
- Guangdong Provincial Engineering Research Center of Autoimmune Disease Precision Medicine, Shenzhen Engineering Research Center of Autoimmune Disease, Shenzhen Clinical Research Center for Geriatrics, Shenzhen People' s Hospital, The Second Clinical Medical College, Jinan University, Shenzhen 518020, China
| | - Da Zhao
- The First Affiliated Hospital, School of Medicine, Anhui University of Science and Technology, Huainan 232001, Anhui, China
| | - Fanna Liu
- Department of Nephrology, The First Affiliated Hospital of Jinan University, Jinan University, Guangzhou 510632, China.
| | - Donge Tang
- Guangdong Provincial Engineering Research Center of Autoimmune Disease Precision Medicine, Shenzhen Engineering Research Center of Autoimmune Disease, Shenzhen Clinical Research Center for Geriatrics, Shenzhen People' s Hospital, The Second Clinical Medical College, Jinan University, Shenzhen 518020, China.
| | - Yong Dai
- Comprehensive Health Industry Research Center, Taizhou Research Institute, Southern University of Science and Technology, Taizhou 317000, China; The First Affiliated Hospital, School of Medicine, Anhui University of Science and Technology, Huainan 232001, Anhui, China.
| |
Collapse
|
2
|
Niu SW, Wu CH, Chen HC, Yang CJ, Chang JM, Chang EE, Chuang HH, Chiu YW, Zhen YY, Hung CC, Hwang SJ. Proteins Secreted by Lung Cancer Cells Induce the Onset of Proteinuria via Focal Adhesion Kinase Signaling in Mice. J Transl Med 2023; 103:100156. [PMID: 37119854 DOI: 10.1016/j.labinv.2023.100156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/24/2023] [Accepted: 04/11/2023] [Indexed: 05/01/2023] Open
Abstract
Paraneoplastic nephrotic syndrome (PNS) is a complication seen in cancer patients. Ultrastructural examination shows the accumulation of proteins and the presence of foot process (FP) effacement in the glomeruli of PNS patients. Previously, we reported that orthotopic xenografts of Lewis lung carcinoma 1 in C57BL/6 mice caused them to develop lung cancer with albuminuria. This implies that these mice can be used as a model of human disease and suggests that Lewis lung carcinoma 1 cell-secreted proteins (LCSePs) contain nephrotoxic molecules and cause inflammation in renal cells. As podocyte effacement was present in glomeruli in this model, such podocyte injury may be attributable to either soluble LCSeP or LCSeP deposits triggering pathological progression. LCSePs in conditioned media was concentrated for nephrotoxicity testing. Integrin-focal adhesion kinase (FAK) signaling and inflammatory responses were evaluated in podocytes either exposed to soluble LCSePs or seeded onto substrates with immobilized LCSePs. FAK phosphorylation and interleukin-6 expression were higher in podocytes attached to LCSePs substrates than in those exposed to soluble LCSePs. Notably, LCSeP-based haptotaxis gave rise to altered signaling in podocytes. When podocytes were stimulated by immobilized LCSePs, FAK accumulated at focal adhesions, synaptopodin dissociated from F-actin, and disrupting the interactions between synaptopodin and α-actinin was observed. When FAK was inhibited by PF-573228 in immobilized LCSePs, the association between synaptopodin and α-actinin was observed in the podocytes. The association of synaptopodin and α-actinin with F-actin allowed FP stretching, establishing a functional glomerular filtration barrier. Therefore, in this mouse model of lung cancer, FAK signaling prompts podocyte FP effacement and proteinuria, indicative of PNS.
Collapse
Affiliation(s)
- Sheng-Wen Niu
- Graduate Institute of Clinical Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Division of Nephrology, Department of Internal Medicine, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chien-Hsing Wu
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Chang-Gung Memorial Hospital, Kaohsiung, Taiwan; College of Medicine, Chang-Gung University, Taoyuan, Taiwan
| | - Hung-Chun Chen
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chih-Jen Yang
- Division of Pulmonary and Critical care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Respiratory Therapy, College of Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Jer-Ming Chang
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Eddy Essen Chang
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Hsiang-Hao Chuang
- Division of Pulmonary and Critical care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yi-Wen Chiu
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Regenerative Medicine and Cell Therapy Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yen-Yi Zhen
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chi-Chih Hung
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; Regenerative Medicine and Cell Therapy Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan.
| | - Shang-Jyh Hwang
- Division of Nephrology, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan; School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
| |
Collapse
|
3
|
Tseng CC, Zheng RH, Lin TW, Chou CC, Shih YC, Liang SW, Lee HH. α-Actinin-4 recruits Shp2 into focal adhesions to potentiate ROCK2 activation in podocytes. Life Sci Alliance 2022; 5:5/11/e202201557. [PMID: 36096674 PMCID: PMC9468603 DOI: 10.26508/lsa.202201557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 08/20/2022] [Accepted: 08/22/2022] [Indexed: 11/24/2022] Open
Abstract
α-Actinin-4 is crucial in the regulation of Shp2 FA targeting to enhance ROCK2-mediated actomyosin contractility and thereby strengthening cell adhesion and cytoskeletal architecture in podocytes. Cell–matrix adhesions are mainly provided by integrin-mediated focal adhesions (FAs). We previously found that Shp2 is essential for FA maturation by promoting ROCK2 activation at FAs. In this study, we further delineated the role of α-actinin-4 in the FA recruitment and activation of Shp2. We used the conditional immortalized mouse podocytes to examine the role of α-actinin-4 in the regulation of Shp2 and ROCK2 signaling. After the induction of podocyte differentiation, Shp2 and ROCK2 were strongly activated, concomitant with the formation of matured FAs, stress fibers, and interdigitating intracellular junctions in a ROCK-dependent manner. Gene knockout of α-actinin-4 abolished the Shp2 activation and subsequently reduced matured FAs in podocytes. We also demonstrated that gene knockout of ROCK2 impaired the generation of contractility and interdigitating intercellular junctions. Our results reveal the role of α-actinin-4 in the recruitment of Shp2 at FAs to potentiate ROCK2 activation for the maintenance of cellular contractility and cytoskeletal architecture in the cultured podocytes.
Collapse
Affiliation(s)
- Chien-Chun Tseng
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Ru-Hsuan Zheng
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Ting-Wei Lin
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Chih-Chiang Chou
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Yu-Chia Shih
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Shao-Wei Liang
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan
| | - Hsiao-Hui Lee
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming Chiao Tung University, Taipei, Taiwan .,Center for Intelligent Drug Systems and Smart Bio-Devices (IDS2B), National Yang Ming Chiao Tung University, Taipei, Taiwan
| |
Collapse
|
4
|
Odenthal J, Dittrich S, Ludwig V, Merz T, Reitmeier K, Reusch B, Höhne M, Cosgun ZC, Hohenadel M, Putnik J, Göbel H, Rinschen MM, Altmüller J, Koehler S, Schermer B, Benzing T, Beck BB, Brinkkötter PT, Habbig S, Bartram MP. Modeling of ACTN4-Based Podocytopathy Using Drosophila Nephrocytes. Kidney Int Rep 2022; 8:317-329. [PMID: 36815115 PMCID: PMC9939316 DOI: 10.1016/j.ekir.2022.10.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/17/2022] [Accepted: 10/24/2022] [Indexed: 11/06/2022] Open
Abstract
Introduction Genetic disorders are among the most prevalent causes leading to progressive glomerular disease and, ultimately, end-stage renal disease (ESRD) in children and adolescents. Identification of underlying genetic causes is indispensable for targeted treatment strategies and counseling of affected patients and their families. Methods Here, we report on a boy who presented at 4 years of age with proteinuria and biopsy-proven focal segmental glomerulosclerosis (FSGS) that was temporarily responsive to treatment with ciclosporin A. Molecular genetic testing identified a novel mutation in alpha-actinin-4 (p.M240T). We describe a feasible and efficient experimental approach to test its pathogenicity by combining in silico, in vitro, and in vivo analyses. Results The de novo p.M240T mutation led to decreased alpha-actinin-4 stability as well as protein mislocalization and actin cytoskeleton rearrangements. Transgenic expression of wild-type human alpha-actinin-4 in Drosophila melanogaster nephrocytes was able to ameliorate phenotypes associated with the knockdown of endogenous actinin. In contrast, p.M240T, as well as other established disease variants p.W59R and p.K255E, failed to rescue these phenotypes, underlining the pathogenicity of the novel alpha-actinin-4 variant. Conclusion Our data highlight that the newly identified alpha-actinin-4 mutation indeed encodes for a disease-causing variant of the protein and promote the Drosophila model as a simple and convenient tool to study monogenic kidney disease in vivo.
Collapse
Affiliation(s)
- Johanna Odenthal
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Sebastian Dittrich
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Vivian Ludwig
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Tim Merz
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Katrin Reitmeier
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Björn Reusch
- Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany,Institute of Human Genetics, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Martin Höhne
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Zülfü C. Cosgun
- Department of Pediatrics, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Maximilian Hohenadel
- Department of Pediatrics, Division of Pediatric Nephrology, University of Bonn, Bonn, Germany
| | - Jovana Putnik
- Mother and Child Health Care Institute of Serbia “Dr Vukan Čupić,” Department of Nephrology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Heike Göbel
- Institute of Pathology, University Hospital of Cologne, Cologne, Germany
| | - Markus M. Rinschen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark,Aarhus Institute of Advanced Studies, Aarhus University, Aarhus, Denmark,III Medical Clinic, University Hospital Hamburg Eppendorf, Hamburg, Germany
| | - Janine Altmüller
- Berlin Institute of Health at Charité-Universitätsmedizin Berlin, Max Delbrück Center for Molecular Medicine, Berlin, Germany,Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Sybille Koehler
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Bernhard Schermer
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany,Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Bodo B. Beck
- Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany,Institute of Human Genetics, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Paul T. Brinkkötter
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany,Correspondence: Paul T. Brinkkoetter, Department II of Internal Medicine, Faculty of Medicine, University of Cologne, University Hospital Cologne, Kerpener Street 62, Cologne 50935, Germany.
| | - Sandra Habbig
- Department of Pediatrics, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| | - Malte P. Bartram
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, Faculty of Medicine, University of Cologne, University Hospital Cologne, Cologne, Germany
| |
Collapse
|
5
|
Hutzfeldt AD, Tan Y, Bonin LL, Beck BB, Baumbach J, Lassé M, Demir F, Rinschen MM. Consensus draft of the native mouse podocyte-ome. Am J Physiol Renal Physiol 2022; 323:F182-F197. [PMID: 35796460 DOI: 10.1152/ajprenal.00058.2022] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The podocyte is a key cell in maintaining renal filtration barrier integrity. Several recent studies have analyzed the entity of genome-coded molecules in the podocyte at deep resolution. This avenue of "podocyte-ome" research was enabled by a variety of techniques, including single-cell transcriptomics, FACS-sorting with and without genetically encoded markers, and deep acquisition of proteomics. However, data across various omics studies are not well-integrated with each other. Here, we aim to establish a common, simplified knowledgebase for the mouse "podocyte-ome" by integrating bulk RNA sequencing and bulk proteomics of sorted podocytes and single cell transcriptomics. Three datasets of each omics type from different laboratories, respectively, were integrated, visualized and bioinformatically analyzed. The procedure sheds light on conserved processes of podocytes, but also on limitations and specific features of the used technologies. High expression of glycan GPI anchor synthesis and turnover, and retinol metabolism was identified as a relatively understudied feature of podocytes, while there are both podocyte-enriched and podocyte-depleted actin binding molecules. We compiled aggregated data in an application that illustrates the features of the dataset and allows for exploratory analyses through individual gene query of podocyte identity in absolute and relative quantification towards other glomerular cell types, keywords, GO-terms and gene set enrichments. This consensus draft is a first step towards common molecular omics knowledge of kidney cells.
Collapse
Affiliation(s)
- Arvid D Hutzfeldt
- III Department of Medicine, grid.13648.38University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Yifan Tan
- Department of Biomedicine, grid.7048.bAarhus University, Aarhus, Denmark
| | - Léna Lydie Bonin
- Department of Biomedicine, grid.7048.bAarhus University, Aarhus, Denmark
| | - Bodo B Beck
- Institute of Human Genetics, Faculty of Medicine and University Hospital Cologne, grid.6190.eUniversity of Cologne, Cologne, Germany
| | - Jan Baumbach
- Institute for Computational Systems Biology, grid.9026.dUniversität Hamburg, Hamburg, Germany
| | - Moritz Lassé
- III Department of Medicine, grid.13648.38University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Fatih Demir
- Department of Biomedicine, grid.7048.bAarhus University, Aarhus, Denmark
| | - Markus M Rinschen
- Department of Biomedicine, grid.7048.bAarhus University, Aarhus, Denmark
| |
Collapse
|
6
|
Tan Y, Lo SH. Endothelial DLC1 is dispensable for liver and kidney function in mice. Genes Dis 2022; 9:814-819. [PMID: 35782987 PMCID: PMC9243348 DOI: 10.1016/j.gendis.2020.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/16/2020] [Accepted: 11/23/2020] [Indexed: 10/26/2022] Open
Abstract
DLC1 is a focal adhesion molecule that regulates cell polarity, proliferation, migration, and survival. DLC1 functions as a tumor suppressor and its expression is often down-regulated in various malignant neoplasms of epithelial origin. Recent studies have suggested that lack of DLC1 in endothelial cells may contribute to the development of angiosarcoma, and that DLC1 mutations have been identified in patients with nephrotic syndrome, a disease mainly due to leaky glomerular filtration barriers. To demonstrate whether lack of endothelial DLC1 induces angiosarcoma and/or damages glomerular capillaries leading to nephrotic syndrome, we have extended our analyses on endothelial cell-specific DLC1 knockout mice with focuses on their liver and kidney function. Mice were monitored up to 24 months of age. However, no histological or clinical difference was found between DLC1 knockout and wild type mice, indicating that lack of endothelial DLC1 alone does not compromise kidney and liver function in mice.
Collapse
Affiliation(s)
- Ying Tan
- Department of Biochemistry and Molecular Medicine, University of California-Davis, Sacramento, CA 95817, USA
| | - Su Hao Lo
- Department of Biochemistry and Molecular Medicine, University of California-Davis, Sacramento, CA 95817, USA
| |
Collapse
|
7
|
Zhong F, Liu S, Li Y, Li G, Liu M, Wang J, Cui W, Suo Y, Gao X. ANGPTL3 impacts proteinuria and hyperlipidemia in primary nephrotic syndrome. Lipids Health Dis 2022; 21:38. [PMID: 35399079 PMCID: PMC8996604 DOI: 10.1186/s12944-022-01632-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Accepted: 02/02/2022] [Indexed: 12/28/2022] Open
Abstract
Abstract
Background
It is unclear why primary nephrotic syndrome (PNS) patients often have dyslipidemia. Recent studies have shown that angiopoietin-like protein 3 (ANGPTL3) is an important regulator of lipid metabolism. In this study, we explored how ANGPTL3 impacts dyslipidemia during PNS development.
Methods
We measured the serum levels of ANGPTL3 in PNS patients (n=196). Furthermore, the degree of proteinuria and lipid metabolism were examined in angptl3-overexpressing transgenic (angptl3-tg) mice at different ages. Moreover, in this study, we used the clustered regularly interspaced short palindromic repeats-associated protein 9 (CRISPR/Cas9) system to create angptl3-knockout (angptl3-/-) mice to investigate lipopolysaccharide (LPS)-induced nephrosis.
Results
Compared with that in the healthy group, the serum level of ANGPTL3 in the PNS group was significantly increased (32 (26.35-39.66) ng/ml vs. 70.44 (63.95-76.51) ng/ml, Z =-4.81, P < 0.001). There were significant correlations between the serum level of ANGPTL3 and the levels of cholesterol (r=0.34, P < 0.001), triglycerides (r= 0.25, P = 0.001) and low-density lipoprotein (r= 0.50, P < 0.001) in PNS patients. With increasing age, angptl3-tg mice exhibited increasingly severe hypertriglyceridemia and proteinuria. The pathological features of angptl3-tg mice included rich lipid droplet deposition in hepatocytes and diffuse podocyte effacement. Compared to wild-type mice, angptl3-/- mice showed significantly lower degrees of lipid dysfunction and proteinuria after stimulation with LPS. The effects of ANGPTL3 on nephrotic dyslipidemia were confirmed in cultured hepatocytes subjected to angptl3 knockdown or overexpression. Finally, significant alterations in lipoprotein lipase (LPL) levels were observed in liver tissues from Angptl3-/- and wild-type mice stimulated with LPS.
Conclusions
ANGPTL3 could be involved in the development of dyslipidemia, as well as proteinuria, during PNS pathogenesis. Inhibition of LPL expression may the mechanism by which ANGPTL3 induces hyperlipidemia in PNS.
Collapse
|
8
|
Rogg M, Maier JI, Van Wymersch C, Helmstädter M, Sammarco A, Lindenmeyer M, Zareba P, Montanez E, Walz G, Werner M, Endlich N, Benzing T, Huber TB, Schell C. α-Parvin Defines a Specific Integrin Adhesome to Maintain the Glomerular Filtration Barrier. J Am Soc Nephrol 2022; 33:786-808. [PMID: 35260418 PMCID: PMC8970443 DOI: 10.1681/asn.2021101319] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 01/17/2022] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The cell-matrix adhesion between podocytes and the glomerular basement membrane is essential for the integrity of the kidney's filtration barrier. Despite increasing knowledge about the complexity of integrin adhesion complexes, an understanding of the regulation of these protein complexes in glomerular disease remains elusive. METHODS We mapped the in vivo composition of the podocyte integrin adhesome. In addition, we analyzed conditional knockout mice targeting a gene (Parva) that encodes an actin-binding protein (α-parvin), and murine disease models. To evaluate podocytes in vivo, we used super-resolution microscopy, electron microscopy, multiplex immunofluorescence microscopy, and RNA sequencing. We performed functional analysis of CRISPR/Cas9-generated PARVA single knockout podocytes and PARVA and PARVB double knockout podocytes in three- and two-dimensional cultures using specific extracellular matrix ligands and micropatterns. RESULTS We found that PARVA is essential to prevent podocyte foot process effacement, detachment from the glomerular basement membrane, and the development of FSGS. Through the use of in vitro and in vivo models, we identified an inherent PARVB-dependent compensatory module at podocyte integrin adhesion complexes, sustaining efficient mechanical linkage at the filtration barrier. Sequential genetic deletion of PARVA and PARVB induces a switch in structure and composition of integrin adhesion complexes. This redistribution of these complexes translates into a loss of the ventral actin cytoskeleton, decreased adhesion capacity, impaired mechanical resistance, and dysfunctional extracellular matrix assembly. CONCLUSIONS The findings reveal adaptive mechanisms of podocyte integrin adhesion complexes, providing a conceptual framework for therapeutic strategies to prevent podocyte detachment in glomerular disease.
Collapse
Affiliation(s)
- Manuel Rogg
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Jasmin I Maier
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Clara Van Wymersch
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Martin Helmstädter
- Department of Medicine IV, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Alena Sammarco
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Maja Lindenmeyer
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Paulina Zareba
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Eloi Montanez
- Department of Physiological Sciences, Faculty of Medicine, University of Barcelona and Health Sciences and Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain
| | - Gerd Walz
- Department of Medicine IV, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Martin Werner
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany
| | - Nicole Endlich
- Department of Anatomy and Cell Biology, University Medicine Greifswald, Greifswald, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - Tobias B Huber
- III. Department of Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christoph Schell
- Institute of Surgical Pathology, Faculty of Medicine, Medical Center-University of Freiburg, Freiburg, Germany .,Freiburg Institute for Advanced Studies (FRIAS), University of Freiburg, Freiburg, Germany
| |
Collapse
|
9
|
Li Y, Gong W, Liu J, Chen X, Suo Y, Yang H, Gao X. Angiopoietin-like protein 4 promotes hyperlipidemia-induced renal injury by down-regulating the expression of ACTN4. Biochem Biophys Res Commun 2022; 595:69-75. [PMID: 35101665 DOI: 10.1016/j.bbrc.2022.01.061] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 01/05/2022] [Accepted: 01/15/2022] [Indexed: 11/02/2022]
Abstract
OBJECTIVE The molecular mechanism of in hyperlipidemia-induced renal injury has not been elucidated. Angiogenin-like protein 4 (ANGPTL4) is a key regulator of lipid metabolism. The role of ANGPTL4 hyperlipidemia-induced renal injury has not been reported. METHODS Wild type C57 mice and gene angptl4 knockout mice were fed with 60% high fat diet or normal diet respectively. The serum lipid, urinary albumin and renal pathology were tested at the 9th, 13th, 17th and 21st week with high fat diet. RESULTS Elevated blood lipids in the wild-type mice with high-fat diet were found at 9th week. At the 17th week, the level of urinary albumin in high-fat fed wild type mice were significantly higher than which with normal diet, correspondingly, segmental fusion of podocyte foot process in kidney could be observed in these hyperlipidemia mice. IHC showed that the expression of ANGPTL4 in glomeruli of high-fat fed wild type mice began significant elevated since the 9th week. When given high fat diet, compared to the wild type, the gene angptl4 knockout mice showed significantly alleviated the levels of hyperlipidemia, proteinuria and effacement of podocyte foot process. Finally, the expression of ACTN4 showed remarkably lower in glomeruli podocyte of wild type mice fed high fat diet than that of wild type mice with normal diet at each time-point (P < 0.01). Differently, the expression of ACTN4 in gene angptl4 knockout mice did not happen significantly weaken when given the same dose of high fat diet. CONCLUSION ANGPTL4 could play a role in hyperlipidemic-induced renal injury via down-regulating the expression of ACTN4 in kidney podocyte.
Collapse
Affiliation(s)
- Yue Li
- Nephrology Department, Guangzhou Women and Children's Medical Center, Guangzhou, 510000, China
| | - Wangqiu Gong
- Nephrology Department, Guangzhou Women and Children's Medical Center, Guangzhou, 510000, China
| | - Jing Liu
- Pediatric Department, Gansu Province People's Hospital, Lanzhou City, 730000, China
| | - Xingxing Chen
- Pediatric Department, Gansu Province People's Hospital, Lanzhou City, 730000, China
| | - Yanhong Suo
- Pediatric Department, Gansu Province People's Hospital, Lanzhou City, 730000, China
| | - Huabing Yang
- Nephrology Department, Guangzhou Women and Children's Medical Center, Guangzhou, 510000, China
| | - Xia Gao
- Nephrology Department, Guangzhou Women and Children's Medical Center, Guangzhou, 510000, China.
| |
Collapse
|
10
|
The Nephrotoxin Puromycin Aminonucleoside Induces Injury in Kidney Organoids Differentiated from Induced Pluripotent Stem Cells. Cells 2022; 11:cells11040635. [PMID: 35203286 PMCID: PMC8870209 DOI: 10.3390/cells11040635] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 01/29/2022] [Accepted: 02/09/2022] [Indexed: 11/17/2022] Open
Abstract
Kidney diseases, including acute kidney injury (AKI) and chronic kidney disease (CKD), which can progress to end stage renal disease (ESRD), are a worldwide health burden. Organ transplantation or kidney dialysis are the only effective available therapeutic tools. Therefore, in vitro models of kidney diseases and the development of prospective therapeutic options are urgently needed. Within the kidney, the glomeruli are involved in blood filtration and waste excretion and are easily affected by changing cellular conditions. Puromycin aminonucleoside (PAN) is a nephrotoxin, which can be employed to induce acute glomerular damage and to model glomerular disease. For this reason, we generated kidney organoids from three iPSC lines and treated these with PAN in order to induce kidney injury. Morphological observations revealed the disruption of glomerular and tubular structures within the kidney organoids upon PAN treatment, which were confirmed by transcriptome analyses. Subsequent analyses revealed an upregulation of immune response as well as inflammatory and cell-death-related processes. We conclude that the treatment of iPSC-derived kidney organoids with PAN induces kidney injury mediated by an intertwined network of inflammation, cytoskeletal re-arrangement, DNA damage, apoptosis and cell death. Furthermore, urine-stem-cell-derived kidney organoids can be used to model kidney-associated diseases and drug discovery.
Collapse
|
11
|
Mo X, Chen X, Wang X, Zhong X, Liang H, Wei Y, Deng H, Hu R, Zhang T, Chen Y, Gao X, Huang M, Li J. Prediction of Tacrolimus Dose/Weight-Adjusted Trough Concentration in Pediatric Refractory Nephrotic Syndrome: A Machine Learning Approach. Pharmgenomics Pers Med 2022; 15:143-155. [PMID: 35228813 PMCID: PMC8881964 DOI: 10.2147/pgpm.s339318] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 01/20/2022] [Indexed: 12/13/2022] Open
Abstract
Purpose Tacrolimus (TAC) is a first-line immunosuppressant for patients with refractory nephrotic syndrome (NS). However, there is a high inter-patient variability of TAC pharmacokinetics, thus therapeutic drug monitoring (TDM) is required. In this study, we aimed to employ machine learning algorithms to investigate the impact of clinical and genetic variables on the TAC dose/weight-adjusted trough concentration (C0/D) in Chinese children with refractory NS, and then develop and validate the TAC C0/D prediction models. Patients and Methods The association of 82 clinical variables and 244 single nucleotide polymorphisms (SNPs) with TAC C0/D in the third month since TAC treatment was examined in 171 children with refractory NS. Extremely randomized trees (ET), gradient boosting decision tree (GBDT), random forest (RF), extreme gradient boosting (XGBoost), and Lasso regression were carried out to establish and validate prediction models, respectively. The best prediction models were validated on a cohort of 30 refractory NS patients. Results GBDT algorithm performed best in the whole group (R2=0.444, MSE=591.032, MAE=20.782, MedAE=18.980) and CYP3A5 nonexpresser group (R2=0.264, MSE=477.948, MAE=18.119, MedAE=18.771), while ET algorithm performed best in the CYP3A5 expresser group (R2=0.380, MSE=1839.459, MAE=31.257, MedAE=19.399). These prediction models included 3 clinical variables (ALB0, AGE0, and gender) and 10 SNPs (ACTN4 rs3745859, ACTN4 rs56113315, ACTN4 rs62121818, CTLA4 rs4553808, CYP3A5 rs776746, IL2RA rs12722489, INF2 rs1128880, MAP3K11 rs7946115, MYH9 rs2239781, and MYH9 rs4821478). Conclusion The association between the clinical and genetic variables and TAC C0/D was described, and three TAC C0/D prediction models integrating clinical and genetic variables were developed and validated using machine learning, which may support individualized TAC dosing.
Collapse
Affiliation(s)
- Xiaolan Mo
- Department of Pharmacy, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, 510623, People’s Republic of China
- Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510080, People’s Republic of China
| | - Xiujuan Chen
- Department of clinical Data Center, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, People’s Republic of China
| | - Xianggui Wang
- Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510080, People’s Republic of China
| | - Xiaoli Zhong
- Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510080, People’s Republic of China
| | - Huiying Liang
- Department of clinical Data Center, Guangdong Provincial People’s Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, People’s Republic of China
| | - Yuanyi Wei
- Department of Pharmacy, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, 510623, People’s Republic of China
| | - Houliang Deng
- Department of Pharmacy, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, 510623, People’s Republic of China
| | - Rong Hu
- Department of Pharmacy, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, 510623, People’s Republic of China
| | - Tao Zhang
- Department of Pharmacy, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, 510623, People’s Republic of China
| | - Yilu Chen
- Department of Pharmacy, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, 510623, People’s Republic of China
| | - Xia Gao
- Division of Nephrology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, 510623, People’s Republic of China
| | - Min Huang
- Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510080, People’s Republic of China
| | - Jiali Li
- Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510080, People’s Republic of China
- Correspondence: Jiali Li; Min Huang, Tel +86-20-39943034; +86-20-39943011, Fax +86-20-39943004; +86-20-39943000, Email ;
| |
Collapse
|
12
|
Afsar B, Afsar RE, Demiray A, Covic A, Kanbay M. Deciphering nutritional interventions for podocyte structure and function. Pharmacol Res 2021; 172:105852. [PMID: 34450318 DOI: 10.1016/j.phrs.2021.105852] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/22/2021] [Accepted: 08/22/2021] [Indexed: 12/11/2022]
Abstract
Despite increasing awareness and therapeutic options chronic kidney disease (CKD) is still and important health problem and glomerular diseases constitute and important percentage of CKD. Proteinuria/albuminuria is not just a marker; but it also plays a direct pathogenic role in renal disease progression of CKD. Glomerular filtration barrier (GFB) which consists of fenestrated endothelial cells, fused basal membrane and interdigitating podocyte foot process and filtration slits between foot process is the major barrier for proteinuria/albuminuria. Many glomerular diseases are characterized by disruption of GFB podocytes, foot process and slit diaphragm. Many proteinuric diseases are non-specifically targeted by therapeutic agents such as steroids and calcineurin inhibitors with systemic side effects. Thus, there is unmet need for more efficient and less toxic therapeutic options to treat glomerular diseases. In recent years, modification of dietary intake, has been gained to treat pathologic processes introducing the concept of 'food as a medicine'. The effect of various nutritional products on podocyte function and structure is also trending, especially in recent years. In the current review, we summarized the effect of nutritional interventions on podocyte function and structure.
Collapse
Affiliation(s)
- Baris Afsar
- Division of Nephrology, Department of Nephrology, Suleyman Demirel University School of Medicine, Isparta, Turkey.
| | - Rengin Elsurer Afsar
- Division of Nephrology, Department of Nephrology, Suleyman Demirel University School of Medicine, Isparta, Turkey
| | - Atalay Demiray
- Department of Medicine, Koc University School of Medicine, Istanbul, Turkey
| | - Adrian Covic
- Department of Nephrology, Grigore T. Popa' University of Medicine, Iasi, Romania
| | - Mehmet Kanbay
- Division of Nephrology, Department of Medicine, Koc University School of Medicine, Istanbul, Turkey
| |
Collapse
|
13
|
Bondue T, Arcolino FO, Veys KRP, Adebayo OC, Levtchenko E, van den Heuvel LP, Elmonem MA. Urine-Derived Epithelial Cells as Models for Genetic Kidney Diseases. Cells 2021; 10:cells10061413. [PMID: 34204173 PMCID: PMC8230018 DOI: 10.3390/cells10061413] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 05/28/2021] [Accepted: 06/02/2021] [Indexed: 12/11/2022] Open
Abstract
Epithelial cells exfoliated in human urine can include cells anywhere from the urinary tract and kidneys; however, podocytes and proximal tubular epithelial cells (PTECs) are by far the most relevant cell types for the study of genetic kidney diseases. When maintained in vitro, they have been proven extremely valuable for discovering disease mechanisms and for the development of new therapies. Furthermore, cultured patient cells can individually represent their human sources and their specific variants for personalized medicine studies, which are recently gaining much interest. In this review, we summarize the methodology for establishing human podocyte and PTEC cell lines from urine and highlight their importance as kidney disease cell models. We explore the well-established and recent techniques of cell isolation, quantification, immortalization and characterization, and we describe their current and future applications.
Collapse
Affiliation(s)
- Tjessa Bondue
- Department of Development and Regeneration, KU Leuven, 3000 Leuven, Belgium; (T.B.); (F.O.A.); (K.R.P.V.); (O.C.A.); (E.L.); (L.P.v.d.H.)
| | - Fanny O. Arcolino
- Department of Development and Regeneration, KU Leuven, 3000 Leuven, Belgium; (T.B.); (F.O.A.); (K.R.P.V.); (O.C.A.); (E.L.); (L.P.v.d.H.)
| | - Koenraad R. P. Veys
- Department of Development and Regeneration, KU Leuven, 3000 Leuven, Belgium; (T.B.); (F.O.A.); (K.R.P.V.); (O.C.A.); (E.L.); (L.P.v.d.H.)
- Department of Pediatrics, Division of Pediatric Nephrology, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Oyindamola C. Adebayo
- Department of Development and Regeneration, KU Leuven, 3000 Leuven, Belgium; (T.B.); (F.O.A.); (K.R.P.V.); (O.C.A.); (E.L.); (L.P.v.d.H.)
- Centre for Molecular and Vascular Biology, Department of Cardiovascular Sciences, KU Leuven, 3000 Leuven, Belgium
| | - Elena Levtchenko
- Department of Development and Regeneration, KU Leuven, 3000 Leuven, Belgium; (T.B.); (F.O.A.); (K.R.P.V.); (O.C.A.); (E.L.); (L.P.v.d.H.)
- Department of Pediatrics, Division of Pediatric Nephrology, University Hospitals Leuven, 3000 Leuven, Belgium
| | - Lambertus P. van den Heuvel
- Department of Development and Regeneration, KU Leuven, 3000 Leuven, Belgium; (T.B.); (F.O.A.); (K.R.P.V.); (O.C.A.); (E.L.); (L.P.v.d.H.)
- Department of Pediatric Nephrology, Radboud University Medical Center, 6500 Nijmegen, The Netherlands
| | - Mohamed A. Elmonem
- Department of Clinical and Chemical Pathology, Faculty of Medicine, Cairo University, Cairo 11628, Egypt
- Correspondence:
| |
Collapse
|
14
|
Sbai O, Soussi R, Bole A, Khrestchatisky M, Esclapez M, Ferhat L. The actin binding protein α-actinin-2 expression is associated with dendritic spine plasticity and migrating granule cells in the rat dentate gyrus following pilocarpine-induced seizures. Exp Neurol 2020; 335:113512. [PMID: 33098872 DOI: 10.1016/j.expneurol.2020.113512] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 10/08/2020] [Accepted: 10/19/2020] [Indexed: 12/24/2022]
Abstract
α-actinin-2 (α-actn-2) is an F-actin-crosslinking protein, localized in dendritic spines. In vitro studies suggested that it is involved in spinogenesis, morphogenesis, actin organization, cell migration and anchoring of the NR1 subunit of the N-methyl-D-aspartate (NMDA) receptors in dendritic spines. However, little is known regarding its function in vivo. We examined the levels of α-actn-2 expression within the dentate gyrus (DG) during the development of chronic limbic seizures (epileptogenesis) induced by pilocarpine in rats. In this model, plasticity of the DG glutamatergic granule cells including spine loss, spinogenesis, morphogenesis, neo-synaptogenesis, aberrant migration, and alterations of NMDA receptors have been well characterized. We showed that α-actn-2 immunolabeling was reduced in the inner molecular layer at 1-2 weeks post-status epilepticus (SE), when granule cell spinogenesis and morphogenesis occur. This low level persisted at the chronic stage when new functional synapses are established. This decreased of α-actn-2 protein is concomitant with the recovery of drebrin A (DA), another actin-binding protein, at the chronic stage. Indeed, we demonstrated in cultured cells that in contrast to DA, α-actn-2 did not protect F-actin destabilization and DA inhibited α-actn-2 binding to F-actin. Such alteration could affect the anchoring of NR1 in dendritic spines. Furthermore, we showed that the expression of α-actn-2 and NR1 are co-down-regulated in membrane fractions of pilocarpine animals at chronic stage. Last, we showed that α-actn-2 is expressed in migrating newly born granule cells observed within the hilus of pilocarpine-treated rats. Altogether, our results suggest that α-actn-2 is not critical for the structural integrity and stabilization of granule cell dendritic spines. Instead, its expression is regulated when spinogenesis and morphogenesis occur and within migrating granule cells. Our data also suggest that the balance between α-actn-2 and DA expression levels may modulate NR1 anchoring within dendritic spines.
Collapse
Affiliation(s)
- Oualid Sbai
- Aix-Marseille Univ, CNRS, INP, Inst Neurophysiopathol, Marseille, France
| | - Rabia Soussi
- Aix-Marseille Univ, CNRS, INP, Inst Neurophysiopathol, Marseille, France
| | - Angélique Bole
- Aix-Marseille Univ, CNRS, INP, Inst Neurophysiopathol, Marseille, France
| | | | - Monique Esclapez
- Aix-Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille, France
| | - Lotfi Ferhat
- Aix-Marseille Univ, CNRS, INP, Inst Neurophysiopathol, Marseille, France.
| |
Collapse
|
15
|
Blaine J, Dylewski J. Regulation of the Actin Cytoskeleton in Podocytes. Cells 2020; 9:cells9071700. [PMID: 32708597 PMCID: PMC7408282 DOI: 10.3390/cells9071700] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 06/30/2020] [Accepted: 07/07/2020] [Indexed: 12/13/2022] Open
Abstract
Podocytes are an integral part of the glomerular filtration barrier, a structure that prevents filtration of large proteins and macromolecules into the urine. Podocyte function is dependent on actin cytoskeleton regulation within the foot processes, structures that link podocytes to the glomerular basement membrane. Actin cytoskeleton dynamics in podocyte foot processes are complex and regulated by multiple proteins and other factors. There are two key signal integration and structural hubs within foot processes that regulate the actin cytoskeleton: the slit diaphragm and focal adhesions. Both modulate actin filament extension as well as foot process mobility. No matter what the initial cause, the final common pathway of podocyte damage is dysregulation of the actin cytoskeleton leading to foot process retraction and proteinuria. Disruption of the actin cytoskeleton can be due to acquired causes or to genetic mutations in key actin regulatory and signaling proteins. Here, we describe the major structural and signaling components that regulate the actin cytoskeleton in podocytes as well as acquired and genetic causes of actin dysregulation.
Collapse
Affiliation(s)
- Judith Blaine
- Renal Division, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA;
| | - James Dylewski
- Renal Division, University of Colorado Anschutz Medical Campus and Denver Health Medical Center, Aurora, CO 80045, USA
- Correspondence: ; Tel.: +303-724-4841
| |
Collapse
|
16
|
Kravets I, Mallipattu SK. The Role of Podocytes and Podocyte-Associated Biomarkers in Diagnosis and Treatment of Diabetic Kidney Disease. J Endocr Soc 2020; 4:bvaa029. [PMID: 32232184 PMCID: PMC7093089 DOI: 10.1210/jendso/bvaa029] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 02/27/2020] [Indexed: 12/23/2022] Open
Abstract
Diabetic kidney disease (DKD) is an important public health problem. Podocyte injury is a central event in the mechanism of DKD development. Podocytes are terminally differentiated, highly specialized glomerular visceral epithelial cells critical for the maintenance of the glomerular filtration barrier. Although potential mechanisms by which diabetic milieu contributes to irreversible loss of podocytes have been described, identification of markers that prognosticate either the development of DKD or the progression to end-stage kidney disease (ESKD) have only recently made it to the forefront. Currently, the most common marker of early DKD is microalbuminuria; however, this marker has significant limitations: not all diabetic patients with microalbuminuria will progress to ESKD and as many as 30% of patients with DKD have normal urine albumin levels. Several novel biomarkers indicating glomerular or tubular damage precede microalbuminuria, suggesting that the latter develops when significant kidney injury has already occurred. Because podocyte injury plays a key role in DKD pathogenesis, identification of markers of early podocyte injury or loss may play an important role in the early diagnosis of DKD. Such biomarkers in the urine include podocyte-released microparticles as well as expression of podocyte-specific markers. Here, we review the mechanisms by which podocyte injury contributes to DKD as well as key markers that have been recently implicated in the development and/or progression of DKD and might serve to identify individuals that require earlier preventative care and treatment in order to slow the progression to ESKD.
Collapse
Affiliation(s)
- Igor Kravets
- Division of Endocrinology, Department of Medicine, Stony Brook University, Stony Brook, NY
| | - Sandeep K Mallipattu
- Division of Nephrology, Department of Medicine, Stony Brook University, Stony Brook, NY
- Renal Section, Northport VA Medical Center, Northport, NY
| |
Collapse
|
17
|
Morigi M, Perico L, Corna D, Locatelli M, Cassis P, Carminati CE, Bolognini S, Zoja C, Remuzzi G, Benigni A, Buelli S. C3a receptor blockade protects podocytes from injury in diabetic nephropathy. JCI Insight 2020; 5:131849. [PMID: 32161193 DOI: 10.1172/jci.insight.131849] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 01/29/2020] [Indexed: 12/14/2022] Open
Abstract
Renal activation of the complement system has been described in patients with diabetic nephropathy (DN), although its pathological relevance is still ill-defined. Here, we studied whether glomerular C3a, generated by uncontrolled complement activation, promotes podocyte damage, leading to proteinuria and renal injury in mice with type 2 diabetes. BTBR ob/ob mice exhibited podocyte loss, albuminuria, and glomerular injury accompanied by C3 deposits and increased C3a and C3a receptor (C3aR) levels. Decreased glomerular nephrin and α-actinin4 expression, coupled with integrin-linked kinase induction, were also observed. Treatment of DN mice with a C3aR antagonist enhanced podocyte density and preserved their phenotype, limiting proteinuria and glomerular injury. Mechanistically, ultrastructural and functional mitochondrial alterations, accompanied by downregulation of antioxidant superoxide dismutase 2 (SOD2) and increased protein oxidation, occurred in podocytes and were normalized by C3aR blockade. In cultured podocytes, C3a induced cAMP-dependent mitochondrial fragmentation. Alterations of mitochondrial membrane potential, SOD2 expression, and energetic metabolism were also found in response to C3a. Notably, C3a-induced podocyte motility was inhibited by SS-31, a peptide with mitochondrial protective effects. These data indicate that C3a blockade represents a potentially novel therapeutic strategy in DN for preserving podocyte integrity through the maintenance of mitochondrial functions.
Collapse
Affiliation(s)
- Marina Morigi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Luca Perico
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Daniela Corna
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Monica Locatelli
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Paola Cassis
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Claudia Elisa Carminati
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Silvia Bolognini
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Carlamaria Zoja
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Giuseppe Remuzzi
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy.,"L. Sacco" Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - Ariela Benigni
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Simona Buelli
- Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| |
Collapse
|
18
|
Mo X, Li J, Liu Y, Liao X, Tan M, Chen Y, He F, He Y, Li Y, Huang M. Kidney podocyte-associated gene polymorphisms affect tacrolimus concentration in pediatric patients with refractory nephrotic syndrome. THE PHARMACOGENOMICS JOURNAL 2020; 20:543-552. [PMID: 31902946 DOI: 10.1038/s41397-019-0141-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 11/24/2019] [Accepted: 12/16/2019] [Indexed: 12/11/2022]
Abstract
Few studies have investigated the correlation between pharmacogenomics and tacrolimus pharmacokinetics in patients with nephrotic syndrome (NS). This study evaluated the influences of genetic polymorphisms of metabolic enzymes, transporters, and podocyte-associated proteins on tacrolimus concentration in Chinese pediatric patients with refractory NS. A total of 167 pediatric patients with refractory NS were included from July 2013 to December 2017. Age of onset was restricted to <14 years of age. Dose-adjusted tacrolimus trough concentration (C0/D) on the third month was calculated, and 20 single-nucleotide polymorphisms in sixteen genes were genotyped. Age was correlated with tacrolimus C0/D (p = 0.006, r = 0.213). Tacrolimus C0/D was higher in CYP3A5 nonexpressers than in CYP3A5 expressers (p = 0.003). ACTN4 rs62121818, MYH9 rs2239781, CYP3A5*3, and age explained 20.5% interindividual variability of tacrolimus concentration in the total cohort. In CYP3A5 nonexpressers, ACTN4 rs62121818 and MYH9 rs2239781 together explained 14.6% variation of tacrolimus C0/D. MYH9 rs2239781, LAMB2 rs62119873 and age together explained 22.3% variability of tacrolimus level in CYP3A5 expressers. CYP3A5*3 was still an important factor affecting tacrolimus concentration in patients with NS. Podocyte-associated gene polymorphisms, especially ACTN4 rs62121818 and MYH9 rs2239781, were the other most important biomarkers for tacrolimus whole blood levels. Genotyping of CYP3A5, ACTN4, and MYH9 polymorphisms may be helpful for better guiding tacrolimus dosing in pediatric patients with refractory NS.
Collapse
Affiliation(s)
- Xiaolan Mo
- Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China.,Department of Pharmacy, Guangzhou Women and Children's medical center, Guangzhou Medical University, Guangzhou, China
| | - Jiali Li
- Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yunfeng Liu
- Clinical Laboratory, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Xin Liao
- Division of nephrology, Guangzhou Women and Children's medical center, Guangzhou Medical University, Guangzhou, China
| | - Mei Tan
- Division of nephrology, Guangzhou Women and Children's medical center, Guangzhou Medical University, Guangzhou, China
| | - Yilu Chen
- Department of Pharmacy, Guangzhou Women and Children's medical center, Guangzhou Medical University, Guangzhou, China
| | - Fan He
- Department of Pharmacy, Guangzhou Women and Children's medical center, Guangzhou Medical University, Guangzhou, China
| | - Yanling He
- Department of Pharmacy, Guangzhou Women and Children's medical center, Guangzhou Medical University, Guangzhou, China.
| | - Yingjie Li
- Division of nephrology, Guangzhou Women and Children's medical center, Guangzhou Medical University, Guangzhou, China.
| | - Min Huang
- Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China.
| |
Collapse
|
19
|
Focal segmental glomerulosclerosis ACTN4 mutants binding to actin: regulation by phosphomimetic mutations. Sci Rep 2019; 9:15517. [PMID: 31664084 PMCID: PMC6820738 DOI: 10.1038/s41598-019-51825-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 10/05/2019] [Indexed: 11/21/2022] Open
Abstract
Natural mutations such as lysine 255 to glutamic acid (K to E), threonine 259 to isoleucine (T to I) and serine 262 to proline (S to P) that occur within the actin binding domain of alpha-actinin-4 (ACTN4) cause an autosomal dominant form of focal segmental glomerulosclerosis (FSGS) in affected humans. This appears due to elevated actin binding propensity in podocytes resulting in a ‘frozen’ cytoskeleton. What is challenging is how this cellular behavior would be compatible with other cell functions that rely on cytoskeleton plasticity. Our previous finding revealed that wild type ACTN4 can be phosphorylated at tyrosine 4 and 31 upon stimulation by epidermal growth factor (EGF) to reduce the binding to actin cytoskeleton. We queried whether the elevated actin binding activity of FSGS mutants can be downregulated by EGF-mediated phosphorylation, to discern a mechanism by which the actin-cytoskeleton can be released in FSGS. In this manuscript, we first constructed variants with Y4/31E to mimic the phosphorylation at tyrosines 4 and 31 based on earlier modeling simulations that predicted that this would bury the actin binding domains and lead to a decrease in actin binding activity. We found that Y4/31E significantly reduced the actin binding activity of K255E, T259I and S262P, dramatically preventing them from aggregating in, and inhibiting motility of, podocytes, fibroblasts and melanoma cells. A putative kinase target site at Y265 in the actin binding domain was also generated as a phosphomimetic ACTN4 Y265E that demonstrated even greater binding to actin filaments than K255E and the other FSGS mutants. That the tyrosine kinase regulation of FSGS mutation binding to actin filaments can occur in cells was shown by phosphorylation on Y4 and Y31 of the K225E after extended exposure of cells to EGF, with a decrease in ACTN4 aggregates in fibroblasts. These findings will provide evidence for targeting the N-termini of FSGS ACTN4 mutants to downregulate their actin binding activities for ameliorating the glomerulosclerotic phenotype of patients.
Collapse
|
20
|
Abstract
Finding new therapeutic targets of glomerulosclerosis treatment is an ongoing quest. Due to a living environment of various stresses and pathological stimuli, podocytes are prone to injuries; moreover, as a cell without proliferative potential, loss of podocytes is vital in the pathogenesis of glomerulosclerosis. Thus, sufficient understanding of factors and underlying mechanisms of podocyte injury facilitates the advancement of treating and prevention of glomerulosclerosis. The clinical symptom of podocyte injury is proteinuria, sometimes with loss of kidney functions progressing to glomerulosclerosis. Injury-induced changes in podocyte physiology and function are actually not a simple passive process, but a complex interaction of proteins that comprise the anatomical structure of podocytes at molecular levels. This chapter lists several aspects of podocyte injuries along with potential mechanisms, including glucose and lipid metabolism disorder, hypertension, RAS activation, micro-inflammation, immune disorder, and other factors. These aspects are not technically separated items, but intertwined with each other in the pathogenesis of podocyte injuries.
Collapse
|
21
|
Kidney-derived c-kit + progenitor/stem cells contribute to podocyte recovery in a model of acute proteinuria. Sci Rep 2018; 8:14723. [PMID: 30283057 PMCID: PMC6170432 DOI: 10.1038/s41598-018-33082-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 09/18/2018] [Indexed: 02/06/2023] Open
Abstract
Kidney-derived c-kit+ cells exhibit progenitor/stem cell properties and can regenerate epithelial tubular cells following ischemia-reperfusion injury in rats. We therefore investigated whether c-kit+ progenitor/stem cells contribute to podocyte repair in a rat model of acute proteinuria induced by puromycin aminonucleoside (PAN), the experimental prototype of human minimal change disease and early stages of focal and segmental glomerulosclerosis. We found that c-kit+ progenitor/stem cells accelerated kidney recovery by improving foot process effacement (foot process width was lower in c-kit group vs saline treated animals, P = 0.03). In particular, these cells engrafted in small quantity into tubules, vessels, and glomeruli, where they occasionally differentiated into podocyte-like cells. This effect was related to an up regulation of α-Actinin-4 and mTORC2-Rictor pathway. Activation of autophagy by c-kit+ progenitor/stem cells also contributed to kidney regeneration and intracellular homeostasis (autophagosomes and autophagolysosomes number and LC3A/B-I and LC3A/B-II expression were higher in the c-kit group vs saline treated animals, P = 0.0031 and P = 0.0009, respectively). Taken together, our findings suggest that kidney-derived c-kit+ progenitor/stem cells exert reparative effects on glomerular disease processes through paracrine effects, to a lesser extent differentiation into podocyte-like cells and contribution to maintenance of podocyte cytoskeleton after injury. These findings have clinical implications for cell therapy of glomerular pathobiology.
Collapse
|
22
|
Cassis P, Locatelli M, Cerullo D, Corna D, Buelli S, Zanchi C, Villa S, Morigi M, Remuzzi G, Benigni A, Zoja C. SGLT2 inhibitor dapagliflozin limits podocyte damage in proteinuric nondiabetic nephropathy. JCI Insight 2018; 3:98720. [PMID: 30089717 DOI: 10.1172/jci.insight.98720] [Citation(s) in RCA: 106] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 06/21/2018] [Indexed: 12/21/2022] Open
Abstract
Sodium-glucose cotransporter 2 (SGLT2) inhibitors have pleiotropic properties beyond blood glucose-lowering effects and modify important nonglycemic pathways, leading to end-organ protection. SGLT2 inhibitors display renoprotective effects in diabetic kidney disease, which creates a rationale for testing the therapeutic potential of this drug class in nondiabetic chronic kidney disease. Here, we have shown that dapagliflozin provided glomerular protection in mice with protein-overload proteinuria induced by bovine serum albumin (BSA), to a similar extent as an ACE inhibitor used as standard therapy for comparison. Dapagliflozin limited proteinuria, glomerular lesions, and podocyte dysfunction and loss. We provide the observation that SGLT2 was expressed in podocytes and upregulated after BSA injections. Through in vitro studies with cultured podocytes loaded with albumin we have identified what we believe to be a novel mechanism of action for SGLT2 inhibitor that directly targets podocytes and relies on the maintenance of actin cytoskeleton architecture. Whether SGLT2 inhibitors represent a possible future therapeutic option for some patients with proteinuric glomerular disease who do not have as yet an effective treatment will require ad hoc clinical studies.
Collapse
Affiliation(s)
- Paola Cassis
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Monica Locatelli
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Domenico Cerullo
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Daniela Corna
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Simona Buelli
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Cristina Zanchi
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Sebastian Villa
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Marina Morigi
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Giuseppe Remuzzi
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy.,Unit of Nephrology and Dialysis, Azienda Socio-Sanitaria Territoriale (ASST) Papa Giovanni XXIII, Bergamo, Italy.,Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - Ariela Benigni
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| | - Carlamaria Zoja
- IRCCS - Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso, Bergamo, Italy
| |
Collapse
|
23
|
Kim DY, Kang MK, Lee EJ, Kim YH, Oh H, Kang YH. Eucalyptol Inhibits Advanced Glycation End Products-Induced Disruption of Podocyte Slit Junctions by Suppressing Rage-Erk-C-Myc Signaling Pathway. Mol Nutr Food Res 2018; 62:e1800302. [PMID: 29987888 DOI: 10.1002/mnfr.201800302] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/28/2018] [Indexed: 02/06/2023]
Abstract
SCOPE The maintenance of interpodocyte slit diaphragm is critical in the sieving function of glomerular filtration barrier. Eucalyptol is a natural constituent in aromatic plants with antioxidant properties. This study investigates whether and how eucalyptol inhibits podocyte slit diaphragm malfunction in glucose-exposed podocytes and diabetic mouse kidneys. METHODS AND RESULTS Podocytes were incubated in media containing 33 mm glucose with 1-20 μm eucalyptol. The in vivo model employed db/db mice orally administrated with 10 mg kg-1 eucalyptol. Nontoxic eucalyptol enhanced podocyte expression of nephrin, podocin, FAT-1, CD2AP, and α-actinin-4 diminished by glucose. Oral administration of eucalyptol augmented the induction of the slit diaphragm proteins, α-actinin-4, and integrin β1 in diabetic kidneys, and ameliorated glomerular fibrosis and foot process effacement. Eucalyptol counteracted the receptor of advanced glycation end products (RAGE) induction in podocytes with glucose or AGE-BSA, and elevated the reduction of the slit diaphragm proteins by AGE-BSA. Eucalyptol attenuated the RAGE induction and AGE accumulation in diabetic kidneys. The blockade of ERK-c-Myc signaling enhanced the nephrin and CD2AP expression downregulated in AGE-exposed podocytes. These results indicate that eucalyptol blocked glucose-induced AGE-RAGE axis and podocyte injury through disturbing RAGE-ERK-c-Myc signaling. CONCLUSION Eucalyptol may be a potent agent antagonizing diabetes-associated malformation of interpodocyte slit junction and podocyte actin cytoskeleton.
Collapse
Affiliation(s)
- Dong Yeon Kim
- Department of Food Science and Nutrition, Hallym University, Chuncheon, Kangwon-do, 24252, Korea
| | - Min-Kyung Kang
- Department of Food Science and Nutrition, Hallym University, Chuncheon, Kangwon-do, 24252, Korea
| | - Eun-Jung Lee
- Department of Food Science and Nutrition, Hallym University, Chuncheon, Kangwon-do, 24252, Korea
| | - Yun-Ho Kim
- Department of Food Science and Nutrition, Hallym University, Chuncheon, Kangwon-do, 24252, Korea
| | - Hyeongjoo Oh
- Department of Food Science and Nutrition, Hallym University, Chuncheon, Kangwon-do, 24252, Korea
| | - Young-Hee Kang
- Department of Food Science and Nutrition, Hallym University, Chuncheon, Kangwon-do, 24252, Korea
| |
Collapse
|
24
|
Yee A, Papillon J, Guillemette J, Kaufman DR, Kennedy CRJ, Cybulsky AV. Proteostasis as a therapeutic target in glomerular injury associated with mutant α-actinin-4. Am J Physiol Renal Physiol 2018; 315:F954-F966. [PMID: 29873512 DOI: 10.1152/ajprenal.00082.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mutations in α-actinin-4 (actinin-4) result in hereditary focal segmental glomerulosclerosis (FSGS) in humans. Actinin-4 mutants induce podocyte injury because of dysregulation of the cytoskeleton and proteotoxicity. Injury may be associated with endoplasmic reticulum (ER) stress and polyubiquitination of proteins. We assessed if the chemical chaperone 4-phenylbutyrate (4-PBA) can ameliorate the proteotoxicity of an actinin-4 mutant. Actinin-4 K255E, which causes FSGS in humans (K256E in the mouse), showed enhanced ubiquitination, accelerated degradation, aggregate formation, and enhanced association with filamentous (F)-actin in glomerular epithelial cells (GECs). The mutant disrupted ER function and stimulated autophagy. 4-PBA reduced actinin-4 K256E aggregation and its tight association with F-actin. Transgenic mice that express actinin-4 K256E in podocytes develop podocyte injury, proteinuria, and FSGS in association with glomerular ER stress. Treatment of these mice with 4-PBA in the drinking water over a 10-wk period significantly reduced albuminuria and ER stress. Another drug, celastrol, which enhanced expression of ER and cytosolic chaperones in GECs, tended to reduce actinin-4 aggregation but did not decrease the tight association of actinin-4 K256E with F-actin and did not reduce albuminuria in actinin-4 K256E transgenic mice. Thus, chemical chaperones, such as 4-PBA, may represent a novel therapeutic approach to certain hereditary glomerular diseases.
Collapse
Affiliation(s)
- Albert Yee
- Department of Medicine, McGill University Health Centre Research Institute, McGill University , Montreal, Quebec , Canada
| | - Joan Papillon
- Department of Medicine, McGill University Health Centre Research Institute, McGill University , Montreal, Quebec , Canada
| | - Julie Guillemette
- Department of Medicine, McGill University Health Centre Research Institute, McGill University , Montreal, Quebec , Canada
| | - Daniel R Kaufman
- Department of Medicine, McGill University Health Centre Research Institute, McGill University , Montreal, Quebec , Canada
| | - Chris R J Kennedy
- Kidney Research Centre, Department of Medicine, The Ottawa Hospital, University of Ottawa , Ottawa, Ontario , Canada
| | - Andrey V Cybulsky
- Department of Medicine, McGill University Health Centre Research Institute, McGill University , Montreal, Quebec , Canada
| |
Collapse
|
25
|
Affiliation(s)
- Martin Pollak
- Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA.
| |
Collapse
|
26
|
Cil O, Perwad F. Monogenic Causes of Proteinuria in Children. Front Med (Lausanne) 2018; 5:55. [PMID: 29594119 PMCID: PMC5858124 DOI: 10.3389/fmed.2018.00055] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 02/15/2018] [Indexed: 01/02/2023] Open
Abstract
Glomerular disease is a common cause for proteinuria and chronic kidney disease leading to end-stage renal disease requiring dialysis or kidney transplantation in children. Nephrotic syndrome in children is diagnosed by the presence of a triad of proteinuria, hypoalbuminemia, and edema. Minimal change disease is the most common histopathological finding in children and adolescents with nephrotic syndrome. Focal segmental sclerosis is also found in children and is the most common pathological finding in patients with monogenic causes of nephrotic syndrome. Current classification system for nephrotic syndrome is based on response to steroid therapy as a majority of patients develop steroid sensitive nephrotic syndrome regardless of histopathological diagnosis or the presence of genetic mutations. Recent studies investigating the genetics of nephrotic syndrome have shed light on the pathophysiology and mechanisms of proteinuria in nephrotic syndrome. Gene mutations have been identified in several subcellular compartments of the glomerular podocyte and play a critical role in mitochondrial function, actin cytoskeleton dynamics, cell-matrix interactions, slit diaphragm, and podocyte integrity. A subset of genetic mutations are known to cause nephrotic syndrome that is responsive to immunosuppressive therapy but clinical data are limited with respect to renal prognosis and disease progression in a majority of patients. To date, more than 50 genes have been identified as causative factors in nephrotic syndrome in children and adults. As genetic testing becomes more prevalent and affordable, we expect rapid advances in our understanding of mechanisms of proteinuria and genetic diagnosis will help direct future therapy for individual patients.
Collapse
Affiliation(s)
- Onur Cil
- Department of Pediatrics, Division of Nephrology, University of California San Francisco, San Francisco, CA, United States
| | - Farzana Perwad
- Department of Pediatrics, Division of Nephrology, University of California San Francisco, San Francisco, CA, United States
| |
Collapse
|
27
|
Srivastava T, Thiagarajan G, Alon US, Sharma R, El-Meanawy A, McCarthy ET, Savin VJ, Sharma M. Role of biomechanical forces in hyperfiltration-mediated glomerular injury in congenital anomalies of the kidney and urinary tract. Nephrol Dial Transplant 2018; 32:759-765. [PMID: 28339567 DOI: 10.1093/ndt/gfw430] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 11/15/2016] [Indexed: 11/13/2022] Open
Abstract
Congenital anomalies of the kidney and urinary tract (CAKUT) including solitary kidney constitute the main cause of progressive chronic kidney disease (CKD) in children. Children born with CAKUT develop signs of CKD only during adolescence and do not respond to renin-angiotensin-aldosterone system blockers. Early cellular changes underlying CKD progression to end-stage renal disease by early adulthood are not well understood. The mechanism of maladaptive hyperfiltration that occurs from loss of functional nephrons, including solitary kidney, is not clear. We re-examine the phenomenon of hyperfiltration in the context of biomechanical forces with special reference to glomerular podocytes. Capillary stretch exerts tensile stress on podocytes through the glomerular basement membrane. The flow of ultrafiltrate over the cell surface directly causes fluid flow shear stress (FFSS) on podocytes. FFSS on the podocyte surface increases 1.5- to 2-fold in animal models of solitary kidney and its effect on podocytes is a subject of ongoing research. Podocytes (i) are mechanosensitive to tensile and shear forces, (ii) use prostaglandin E2, angiotensin-II or nitric oxide for mechanoperception and (iii) use specific signaling pathways for mechanotransduction. We discuss (i) the nature of and differences in cellular responses to biomechanical forces, (ii) methods to study biomechanical forces and (iii) effects of biomechanical forces on podocytes and glomeruli. Future studies on FFSS will likely identify novel targets for strategies for early intervention to complement and strengthen the current regimen for treating children with CAKUT.
Collapse
Affiliation(s)
- Tarak Srivastava
- Section of Nephrology, Children's Mercy Hospital and University of Missouri at Kansas City, Kansas City, MO, USA.,Renal Research Laboratory, Research and Development, Kansas City VA Medical Center, Kansas City, MO, USA
| | - Ganesh Thiagarajan
- School of Computing and Engineering, University of Missouri at Kansas City, MO, USA
| | - Uri S Alon
- Section of Nephrology, Children's Mercy Hospital and University of Missouri at Kansas City, Kansas City, MO, USA
| | - Ram Sharma
- Renal Research Laboratory, Research and Development, Kansas City VA Medical Center, Kansas City, MO, USA
| | - Ashraf El-Meanawy
- Division of Nephrology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Ellen T McCarthy
- Kidney Institute, Kansas University Medical Center, Kansas City, KS, USA
| | - Virginia J Savin
- Renal Research Laboratory, Research and Development, Kansas City VA Medical Center, Kansas City, MO, USA
| | - Mukut Sharma
- Renal Research Laboratory, Research and Development, Kansas City VA Medical Center, Kansas City, MO, USA
| |
Collapse
|
28
|
Shao H, Wang A, Lauffenburger D, Wells A. Tyro3-mediated phosphorylation of ACTN4 at tyrosines is FAK-dependent and decreases susceptibility to cleavage by m-Calpain. Int J Biochem Cell Biol 2017; 95:73-84. [PMID: 29274473 DOI: 10.1016/j.biocel.2017.12.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 11/14/2017] [Accepted: 12/19/2017] [Indexed: 11/29/2022]
Abstract
Tyro3, a member of TAM receptor tyrosine kinase family, has been implicated in the regulation of melanoma progression and survival. In this study, we sought the molecular mechanism of Tyro3 effects avoiding endogenous background by overexpression of Tyro3 in fibroblasts that have negligible levels of Tyro3. This introduction triggers the tyrosyl-phosphorylation of ACTN4, a member of actin binding protein family involved in motility, a behavior critical for invasive progression, as shown by siRNA to Tyro3 limiting melanoma cell migration and invasion. Tyro3-mediated phosphorylation of ACTN4 required FAK activation at tyrosine 397 and the EGF receptor cascade, but not EGFR ligand binding. Using PCR-based mutagenesis, the sites of Tyro3-mediated ACTN4 phosphorylation were mapped to ACTN4 tyrosine 11 and 13, and this occurs in conjunction with EGF-mediated phosphorylation on Y4 and Y31. Interestingly, Tyro3-mediated phosphorylation only slightly decreases the actin binding activity of ACTN4. However, this rendered the phosphorylated ACTN4 resistant to the m-calpain cleavage between Y13 and G14, a limited proteolysis that prevents growth factor regulation of ACTN4 interaction with F-actin. Overexpression of both WT ACTN4 and ACTN4Y11/13E, a mimic of ACTN4 phosphorylated at tyrosine 11 and 13, in melanoma WM983b cells resulted in a likely mesenchymal to amoeboidal transition. ACTN4Y11/13E-expressing cells were more amoeboidal, less migratory on collagen I gel coated surface but more invasive through collagen networks. In parallel, expression of ACTN4Y11/13E, in ACTN4 knockdown melanoma WM1158 cells resulted in an increase of invasion compared to WT ACTN4. These findings suggest that Tyro3-mediated phosphorylation of ACTN4 is involved in invasion of melanoma cells.
Collapse
Affiliation(s)
- Hanshuang Shao
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, United States
| | - Anna Wang
- University of Virginia, Charlottesville, VA 22904, United States
| | | | - Alan Wells
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, United States; Pittsburgh VA Health System, Pittsburgh, PA 15213, United States.
| |
Collapse
|
29
|
Nanoscale imaging of clinical specimens using pathology-optimized expansion microscopy. Nat Biotechnol 2017; 35:757-764. [PMID: 28714966 PMCID: PMC5548617 DOI: 10.1038/nbt.3892] [Citation(s) in RCA: 139] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 04/28/2017] [Indexed: 01/10/2023]
Abstract
Expansion microscopy (ExM), a method for improving the resolution of light microscopy by physically expanding the specimen, has not been applied to clinical tissue samples. Here we report a clinically optimized form of ExM that supports nanoscale imaging of human tissue specimens that have been fixed with formalin, embedded in paraffin, stained with hematoxylin and eosin (H&E), and/or fresh frozen. The method, which we call expansion pathology (ExPath), converts clinical samples into an ExM-compatible state, then applies an ExM protocol with protein anchoring and mechanical homogenization steps optimized for clinical samples. ExPath enables ~70 nm resolution imaging of diverse biomolecules in intact tissues using conventional diffraction-limited microscopes, and standard antibody and fluorescent DNA in situ hybridization reagents. We use ExPath for optical diagnosis of kidney minimal-change disease, which previously required electron microscopy (EM), and demonstrate high-fidelity computational discrimination between early breast neoplastic lesions that to date have challenged human judgment. ExPath may enable the routine use of nanoscale imaging in pathology and clinical research.
Collapse
|
30
|
Pichler R, Afkarian M, Dieter BP, Tuttle KR. Immunity and inflammation in diabetic kidney disease: translating mechanisms to biomarkers and treatment targets. Am J Physiol Renal Physiol 2017; 312:F716-F731. [PMID: 27558558 PMCID: PMC6109808 DOI: 10.1152/ajprenal.00314.2016] [Citation(s) in RCA: 162] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 08/16/2016] [Indexed: 01/10/2023] Open
Abstract
Increasing incidences of obesity and diabetes have made diabetic kidney disease (DKD) the leading cause of chronic kidney disease and end-stage renal disease worldwide. Despite current pharmacological treatments, including strategies for optimizing glycemic control and inhibitors of the renin-angiotensin system, DKD still makes up almost one-half of all cases of end-stage renal disease in the United States. Compelling and mounting evidence has clearly demonstrated that immunity and inflammation play a paramount role in the pathogenesis of DKD. This article reviews the involvement of the immune system in DKD and identifies important roles of key immune and inflammatory mediators. One of the most recently identified biomarkers is serum amyloid A, which appears to be relatively specific for DKD. Novel and evolving treatment approaches target protein kinases, transcription factors, chemokines, adhesion molecules, growth factors, advanced glycation end-products, and other inflammatory molecules. This is the beginning of a new era in the understanding and treatment of DKD, and we may have finally reached a tipping point in our fight against the growing burden of DKD.
Collapse
Affiliation(s)
- Raimund Pichler
- Division of Nephrology, University of Washington, Seattle, Washington;
| | - Maryam Afkarian
- Division of Nephrology, Kidney Research Institute, University of Washington, Seattle, Washington; and
| | - Brad P Dieter
- Division of Nephrology, Kidney Research Institute, University of Washington, Seattle, Washington; and
- Providence Health Care, Spokane, Washington
| | - Katherine R Tuttle
- Division of Nephrology, Kidney Research Institute, University of Washington, Seattle, Washington; and
- Providence Health Care, Spokane, Washington
| |
Collapse
|
31
|
He P, Liu D, Zhang B, Zhou G, Su X, Wang Y, Li D, Yang X. Hepatitis B Virus X Protein Reduces Podocyte Adhesion via Downregulation of α3β1 Integrin. Cell Physiol Biochem 2017; 41:689-700. [PMID: 28214836 DOI: 10.1159/000458428] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 12/13/2016] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND/AIMS Hepatitis B virus (HBV)-associated glomerulonephritis (HBV-GN) is characterized by a reduced number of podocytes due to apoptosis and shedding from the basement membrane. However, the pathological mechanism of HBV-GN is unclear. We previously showed that hepatitis B virus X protein (HBx) promotes apoptosis in tubular epithelial cells. In this study, we transfected podocytes with HBx and examined the effects on adhesion and apoptosis of these cells. METHODS Podocytes were transfected with pc-DNA3.1 (+)-HBx. One control group was not transfected and another control group was transfected with empty plasmids. Podocyte adhesion was assessed by a fluorescence assay, apoptosis was measured by flow cytometry and fluorescence microscopy, and expression of α3β1 integrin was determined by western blotting and the reverse transcription polymerase chain reaction (RT-PCR). Activity of caspase-8 was measured by a spectrophotometric assay. RESULTS Relative to controls, podocytes with pc-DNA3.1(+)-HBx had reduced cell adhesion, increased apoptosis, reduced expression of α3β1 integrin, and increased caspase-8 activity. β1 integrin blockage reduced podocyte adhesion, but increased apoptosis and caspase-8 activity. Treatment of transfected podocytes with a caspase-8 inhibitor (Z-IETD-FMK) had no effect on the HBx-mediated integrin downregulation and reduced podocyte adhesion, suggesting that α3β1 integrin downregulaton is sufficient to alter cell adhesion. CONCLUSIONS Our in vitro results indicate that HBx reduced podocyte adhesion and expression of α3β1 integrin, and increased apoptosis. Moreover, HBx-mediated downregulation of α3β1 integrin expression is sufficient to reduce podocyte adhesion. HBx-induced apoptosis of podocytes may contribute to HBV-GN.
Collapse
|
32
|
Wang D, Li XW, Wang X, Tan HR, Jia Y, Yang L, Li XM, Shang MY, Xu F, Yang XX, Shoyama Y, Cai SQ. Alpha-Actinin-4 is a Possible Target Protein for Aristolochic Acid I in Human Kidney Cells In Vitro. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2016; 44:291-304. [PMID: 27080942 DOI: 10.1142/s0192415x16500178] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Aristolochic acid I (AA-I) is a strong nephrotoxin, carcinogen, and mutagen found in plants such as the Aristolochia species. The mechanisms underlying AA-I toxicity in the kidneys are poorly understood. In this study, we aimed to gain insight into the mechanism of AA-I nephrotoxicity by analyzing the uptake, subcellular distribution, and intracellular targets of AA-I in the human kidney cell line HK-2 using immunocytochemistry, immunoprecipitation, and LC-MS/MS. In HK-2 cells incubated with 20[Formula: see text][Formula: see text]g/mL AA-I for different periods of time (up to 12[Formula: see text]h), AA-I was detected by a specific monoclonal antibody (MAb) against AA-I, both in the cytoplasm and nuclei. Nuclear localization depended on the exposure time. A protein with the molecular weight of 100 kDa was immunoprecipitated with the anti-AA-I MAb from the AA-I-treated cell lysates and was identified by LC-MS/MS as [Formula: see text]-actinin-4 after digestion of the protein, and was confirmed by immunoblotting with a specific anti-[Formula: see text]-actinin-4 MAb. This evidence shows, for the first time, that [Formula: see text]-actinin-4 is a protein targeted by AA-I in kidney cells. Our findings strongly suggest an association between [Formula: see text]-actinin-4 and AA-I nephrotoxic activity.
Collapse
Affiliation(s)
- Dan Wang
- * State Key Laboratory of Natural and Biomimetic Drugs.,† Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, P.R. China
| | - Xiao-Wei Li
- * State Key Laboratory of Natural and Biomimetic Drugs.,† Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, P.R. China
| | - Xuan Wang
- † Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100191, P.R. China
| | - Huan-Ran Tan
- ‡ Department of Pharmacology, Peking University, Health Science Center, Beijing 100191, P.R. China
| | - Yan Jia
- § Renal Division, Department of Medicine, Peking University First Hospital, Beijing 100034, P.R. China
| | - Li Yang
- § Renal Division, Department of Medicine, Peking University First Hospital, Beijing 100034, P.R. China
| | - Xiao-Mei Li
- § Renal Division, Department of Medicine, Peking University First Hospital, Beijing 100034, P.R. China
| | | | - Feng Xu
- * State Key Laboratory of Natural and Biomimetic Drugs
| | - Xing-Xin Yang
- * State Key Laboratory of Natural and Biomimetic Drugs
| | - Yukihiro Shoyama
- ¶ Department of Pharmacognosy, Faculty of Pharmaceutical Sciences, Nagasaki International University, Sasebo, Nagasaki 859-3298, Japan
| | - Shao-Qing Cai
- * State Key Laboratory of Natural and Biomimetic Drugs
| |
Collapse
|
33
|
Abstract
Genetic studies of hereditary forms of nephrotic syndrome have identified several proteins that are involved in regulating the permselective properties of the glomerular filtration system. Further extensive research has elucidated the complex molecular basis of the glomerular filtration barrier and clearly established the pivotal role of podocytes in the pathophysiology of glomerular diseases. Podocyte architecture is centred on focal adhesions and slit diaphragms - multiprotein signalling hubs that regulate cell morphology and function. A highly interconnected actin cytoskeleton enables podocytes to adapt in order to accommodate environmental changes and maintain an intact glomerular filtration barrier. Actin-based endocytosis has now emerged as a regulator of podocyte integrity, providing an impetus for understanding the precise mechanisms that underlie the steady-state control of focal adhesion and slit diaphragm components. This Review outlines the role of actin dynamics and endocytosis in podocyte biology, and discusses how molecular heterogeneity in glomerular disorders could be exploited to deliver more rational therapeutic interventions, paving the way for targeted medicine in nephrology.
Collapse
|
34
|
Parrish AR. The cytoskeleton as a novel target for treatment of renal fibrosis. Pharmacol Ther 2016; 166:1-8. [PMID: 27343756 DOI: 10.1016/j.pharmthera.2016.06.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 06/07/2016] [Indexed: 12/23/2022]
Abstract
The incidence of chronic kidney disease (CKD) is increasing, with an estimated prevalence of 12% in the United States (Synder et al., 2009). While CKD may progress to end-stage renal disease (ESRD), which necessitates renal replacement therapy, i.e. dialysis or transplantation, most CKD patients never reach ESRD due to the increased risk of death from cardiovascular disease. It is well-established that regardless of the initiating insult - most often diabetes or hypertension - fibrosis is the common pathogenic pathway that leads to progressive injury and organ dysfunction (Eddy, 2014; Duffield, 2014). As such, there has been extensive research into the molecular and cellular mechanisms of renal fibrosis; however, translation to effective therapeutic strategies has been limited. While a role for the disruption of the cytoskeleton, most notably the actin network, has been established in acute kidney injury over the past two decades, a role in regulating renal fibrosis and CKD is only recently emerging. This review will focus on the role of the cytoskeleton in regulating pro-fibrotic pathways in the kidney, as well as data suggesting that these pathways represent novel therapeutic targets to manage fibrosis and ultimately CKD.
Collapse
Affiliation(s)
- Alan R Parrish
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, MO 65212, USA.
| |
Collapse
|
35
|
Li Y, Christensen JR, Homa KE, Hocky GM, Fok A, Sees JA, Voth GA, Kovar DR. The F-actin bundler α-actinin Ain1 is tailored for ring assembly and constriction during cytokinesis in fission yeast. Mol Biol Cell 2016; 27:1821-33. [PMID: 27075176 PMCID: PMC4884072 DOI: 10.1091/mbc.e16-01-0010] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 04/06/2016] [Indexed: 12/18/2022] Open
Abstract
The actomyosin contractile ring is a network of cross-linked actin filaments that facilitates cytokinesis in dividing cells. Contractile ring formation has been well characterized in Schizosaccharomyces pombe, in which the cross-linking protein α-actinin SpAin1 bundles the actin filament network. However, the specific biochemical properties of SpAin1 and whether they are tailored for cytokinesis are not known. Therefore we purified SpAin1 and quantified its ability to dynamically bind and bundle actin filaments in vitro using a combination of bulk sedimentation assays and direct visualization by two-color total internal reflection fluorescence microscopy. We found that, while SpAin1 bundles actin filaments of mixed polarity like other α-actinins, SpAin1 has lower bundling activity and is more dynamic than human α-actinin HsACTN4. To determine whether dynamic bundling is important for cytokinesis in fission yeast, we created the less dynamic bundling mutant SpAin1(R216E). We found that dynamic bundling is critical for cytokinesis, as cells expressing SpAin1(R216E) display disorganized ring material and delays in both ring formation and constriction. Furthermore, computer simulations of initial actin filament elongation and alignment revealed that an intermediate level of cross-linking best facilitates filament alignment. Together our results demonstrate that dynamic bundling by SpAin1 is important for proper contractile ring formation and constriction.
Collapse
Affiliation(s)
- Yujie Li
- Committee on Genetics, Genomics and Systems Biology, University of Chicago, Chicago, IL 60637
| | - Jenna R Christensen
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637
| | - Kaitlin E Homa
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637
| | - Glen M Hocky
- Department of Chemistry, James Franck Institute, Institute for Biophysical Dynamics, and Computation Institute, University of Chicago, Chicago, IL 60637
| | - Alice Fok
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637
| | - Jennifer A Sees
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637
| | - Gregory A Voth
- Department of Chemistry, James Franck Institute, Institute for Biophysical Dynamics, and Computation Institute, University of Chicago, Chicago, IL 60637
| | - David R Kovar
- Committee on Genetics, Genomics and Systems Biology, University of Chicago, Chicago, IL 60637 Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL 60637 Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637
| |
Collapse
|
36
|
Ura B, Scrimin F, Arrigoni G, Athanasakis E, Aloisio M, Monasta L, Ricci G. Abnormal expression of leiomyoma cytoskeletal proteins involved in cell migration. Oncol Rep 2016; 35:3094-100. [PMID: 26986808 DOI: 10.3892/or.2016.4688] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 11/05/2015] [Indexed: 11/05/2022] Open
Abstract
Uterine leiomyomas are monoclonal tumors. Several factors are involved in the neoplastic transformation of the myometrium. In our study we focused on dysregulated cytoskeletal proteins in the leiomyoma as compared to the myometrium. Paired tissue samples of ten leiomyomas and adjacent myometria were obtained and analyzed by two‑dimensional gel electrophoresis (2-DE). Mass spectrometry was used for protein identification, and western blotting for 2-DE data validation. The values of ten cytoskeletal proteins were found to be significantly different: eight proteins were upregulated in the leiomyoma and two proteins were downregulated. Three of the upregulated proteins (myosin regulatory light polypeptide 9, four and a half LIM domains protein 1 and LIM and SH3 domain protein 1) are involved in cell migration, while downregulated protein transgelin is involved in replicative senescence. Myosin regulatory light polypeptide 9 (MYL9) was further validated by western blotting because it is considered to be a cell migration marker in several cancers and could play a key role in leiomyoma development. Our data demonstrate significant alterations in the expression of cytoskeletal proteins involved in leiomyoma growth. A better understanding of the involvement of cytoskeletal proteins in leiomyoma pathogenesis may contribute to the identification of new therapeutic targets and the development of new pharmacological approaches.
Collapse
Affiliation(s)
- Blendi Ura
- Institute for Maternal and Child Health - IRCCS 'Burlo Garofolo', Trieste, Italy
| | - Federica Scrimin
- Institute for Maternal and Child Health - IRCCS 'Burlo Garofolo', Trieste, Italy
| | - Giorgio Arrigoni
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | | | - Michelangelo Aloisio
- Institute for Maternal and Child Health - IRCCS 'Burlo Garofolo', Trieste, Italy
| | - Lorenzo Monasta
- Institute for Maternal and Child Health - IRCCS 'Burlo Garofolo', Trieste, Italy
| | - Giuseppe Ricci
- Institute for Maternal and Child Health - IRCCS 'Burlo Garofolo', Trieste, Italy
| |
Collapse
|
37
|
Ivanova EA, Arcolino FO, Elmonem MA, Rastaldi MP, Giardino L, Cornelissen EM, van den Heuvel LP, Levtchenko EN. Cystinosin deficiency causes podocyte damage and loss associated with increased cell motility. Kidney Int 2016; 89:1037-1048. [PMID: 27083281 DOI: 10.1016/j.kint.2016.01.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 12/22/2015] [Accepted: 01/07/2016] [Indexed: 12/14/2022]
Abstract
The involvement of the glomerulus in the pathogenesis of cystinosis, caused by loss-of-function mutations in cystinosin (CTNS, 17p13), is a matter of controversy. Although patients with cystinosis demonstrate glomerular lesions and high-molecular-weight proteinuria starting from an early age, a mouse model of cystinosis develops only signs of proximal tubular dysfunction. Here we studied podocyte damage in patients with cystinosis by analyzing urinary podocyte excretion and by in vitro studies of podocytes deficient in cystinosin. Urine from patients with cystinosis presented a significantly higher amount of podocytes compared with controls. In culture, cystinotic podocytes accumulated cystine compatible with cystinosin deficiency. The expression of podocyte specific genes CD2AP, podocalyxin, and synaptopodin and of the WT1 protein was evident in all cell lines. Conditionally immortalized podocyte lines of 2 patients with different CTNS mutations had altered cytoskeleton, impaired cell adhesion sites, and increased individual cell motility. Moreover, these cells showed enhanced phosphorylation of both Akt1 and Akt2 (isoforms of protein kinase B). Inhibition of Akt by a specific inhibitor (Akti inhibitor 1/2) resulted in normalization of the hypermotile phenotype. Thus, our study extends the list of genetic disorders causing podocyte damage and provides the evidence of altered cell signaling cascades resulting in impaired cell adhesion and enhanced cell motility in cystinosis.
Collapse
Affiliation(s)
- Ekaterina A Ivanova
- Department of Development and Regeneration, Laboratory of Pediatric Nephrology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Fanny O Arcolino
- Department of Development and Regeneration, Laboratory of Pediatric Nephrology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Mohamed A Elmonem
- Department of Development and Regeneration, Laboratory of Pediatric Nephrology, Katholieke Universiteit Leuven, Leuven, Belgium; Department of Clinical and Chemical Pathology, Faculty of Medicine, Cairo University, Cairo, Egypt
| | - Maria P Rastaldi
- Renal Research Laboratory, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico and Fondazione D'Amico, Milano, Italy
| | - Laura Giardino
- Renal Research Laboratory, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico and Fondazione D'Amico, Milano, Italy
| | - Elisabeth M Cornelissen
- Department of Pediatric Nephrology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Lambertus P van den Heuvel
- Department of Development and Regeneration, Laboratory of Pediatric Nephrology, Katholieke Universiteit Leuven, Leuven, Belgium; Department of Pediatric Nephrology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Elena N Levtchenko
- Department of Development and Regeneration, Laboratory of Pediatric Nephrology, Katholieke Universiteit Leuven, Leuven, Belgium.
| |
Collapse
|
38
|
Autophagy protects podocytes from sublytic complement induced injury. Exp Cell Res 2016; 341:132-8. [PMID: 26883468 DOI: 10.1016/j.yexcr.2016.02.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 02/10/2016] [Accepted: 02/12/2016] [Indexed: 11/22/2022]
Abstract
Podocyte injury induced by sublytic complement attack is the main feature of membranous nephropathy (MN). This study aimed at investigating the impact of sublytic complement attack-related autophagy on podocyte injury in vitro. Here, we show that sublytic complement attack enhances MPC5 podocyte autophagy in vitro. Inhibition of autophagy by treatment with 3-methyladenine (3-MA) significantly increased sublytic complement attack-induced changes in the injury-related morphology, stress fiber, and podocyte apoptosis, but decreased the survival and adhesion of MPC5 podocytes. In contrast, promotion of autophagy by treatment with rapamycin mitigated sublytic complement attack-induced changes in the injury-related morphology, stress fiber, and podocyte apoptosis, but increased the survival and adhesion of MPC5 podocytes. These data suggest that autophagy may protect podocytes from sublytic complement attack-induced injury in vitro.
Collapse
|
39
|
Bartram MP, Habbig S, Pahmeyer C, Höhne M, Weber LT, Thiele H, Altmüller J, Kottoor N, Wenzel A, Krueger M, Schermer B, Benzing T, Rinschen MM, Beck BB. Three-layered proteomic characterization of a novel ACTN4 mutation unravels its pathogenic potential in FSGS. Hum Mol Genet 2016; 25:1152-64. [PMID: 26740551 DOI: 10.1093/hmg/ddv638] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Accepted: 12/31/2015] [Indexed: 01/09/2023] Open
Abstract
Genetic diseases constitute the most important cause for end-stage renal disease in children and adolescents. Mutations in the ACTN4 gene, encoding the actin-binding protein α-actinin-4, are a rare cause of autosomal dominant familial focal segmental glomerulosclerosis (FSGS). Here, we report the identification of a novel, disease-causing ACTN4 mutation (p.G195D, de novo) in a sporadic case of childhood FSGS using next generation sequencing. Proteome analysis by quantitative mass spectrometry (MS) of patient-derived urinary epithelial cells indicated that ACTN4 levels were significantly decreased when compared with healthy controls. By resolving the peptide bearing the mutated residue, we could proof that the mutant protein is less abundant when compared with the wild-type protein. Further analyses revealed that the decreased stability of p.G195D is associated with increased ubiquitylation in the vicinity of the mutation site. We next defined the ACTN4 interactome, which was predominantly composed of cytoskeletal modulators and LIM domain-containing proteins. Interestingly, this entire group of proteins, including several highly specific ACTN4 interactors, was globally decreased in the patient-derived cells. Taken together, these data suggest a mechanistic link between ACTN4 instability and proteome perturbations of the ACTN4 interactome. Our findings advance the understanding of dominant effects exerted by ACTN4 mutations in FSGS. This study illustrates the potential of genomics and complementary, high-resolution proteomics analyses to study the pathogenicity of rare gene variants.
Collapse
Affiliation(s)
- Malte P Bartram
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Sandra Habbig
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany, Department of Pediatrics
| | - Caroline Pahmeyer
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany
| | - Martin Höhne
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and Systems Biology of Ageing Cologne, University of Cologne, Cologne, Germany
| | | | | | | | | | | | - Marcus Krueger
- Institute for Genetics, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and
| | - Bernhard Schermer
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and Systems Biology of Ageing Cologne, University of Cologne, Cologne, Germany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and Systems Biology of Ageing Cologne, University of Cologne, Cologne, Germany
| | - Markus M Rinschen
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and Systems Biology of Ageing Cologne, University of Cologne, Cologne, Germany
| | | |
Collapse
|
40
|
Feng D, DuMontier C, Pollak MR. The role of alpha-actinin-4 in human kidney disease. Cell Biosci 2015; 5:44. [PMID: 26301083 PMCID: PMC4545552 DOI: 10.1186/s13578-015-0036-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 07/24/2015] [Indexed: 11/19/2022] Open
Abstract
Mutations in the Alpha-actinin-4 gene (ACTN4) cause a rare form of familial focal segmental glomerulosclerosis in humans. Individuals with kidney disease-associated ACTN4 mutations tend to have mild to moderate proteinuria, with many developing decreased kidney function progressing to end stage kidney disease. All of the disease-causing ACTN4 mutations identified to date are located within the actin-binding domain of the encoded protein, increasing its binding affinity to F-actin and leading to abnormal actin rich cellular aggregates. The identification of ACTN4 mutations as a cause of human kidney disease demonstrates a key cellular pathway by which alterations in cytoskeletal behavior can mediate kidney disease. Here we review the studies relevant to ACTN4 and its role in mediating kidney disease.
Collapse
Affiliation(s)
- Di Feng
- Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215 USA
| | - Clark DuMontier
- Department of Medicine, Boston University School of Medicine, Boston, MA 02118 USA
| | - Martin R Pollak
- Division of Nephrology, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215 USA
| |
Collapse
|
41
|
Rheault MN, Gbadegesin RA. The Genetics of Nephrotic Syndrome. J Pediatr Genet 2015; 5:15-24. [PMID: 27617138 DOI: 10.1055/s-0035-1557109] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 01/21/2015] [Indexed: 12/26/2022]
Abstract
Nephrotic syndrome (NS) is a common pediatric kidney disease and is defined as massive proteinuria, hypoalbuminemia, and edema. Dysfunction of the glomerular filtration barrier, which is made up of endothelial cells, glomerular basement membrane, and visceral epithelial cells known as podocytes, is evident in children with NS. While most children have steroid-responsive nephrotic syndrome (SSNS), approximately 20% have steroid-resistant nephrotic syndrome (SRNS) and are at risk for progressive kidney dysfunction. While the cause of SSNS is still not well understood, there has been an explosion of research into the genetic causes of SRNS in the past 15 years. More than 30 proteins regulating the function of the glomerular filtration barrier have been associated with SRNS including podocyte slit diaphragm proteins, podocyte actin cytoskeletal proteins, mitochondrial proteins, adhesion and glomerular basement membrane proteins, transcription factors, and others. A genetic cause of SRNS can be found in approximately 70% of infants presenting in the first 3 months of life and 50% of infants presenting between 4 and 12 months, with much lower likelihood for older patients. Identification of the underlying genetic etiology of SRNS is important in children because it allows for counseling of other family members who may be at risk, predicts risk of recurrent disease after kidney transplant, and predicts response to immunosuppressive therapy. Correlations between genetic mutation and clinical phenotype as well as genetic risk factors for SSNS and SRNS are reviewed in this article.
Collapse
Affiliation(s)
- Michelle N Rheault
- Division of Nephrology, University of Minnesota Masonic Children's Hospital, Minneapolis, Minnesota, United States
| | - Rasheed A Gbadegesin
- Division of Nephrology and Center for Human Genetics, Duke University Medical Center, Durham, North Carolina, United States
| |
Collapse
|
42
|
Liu J, Gao X, Zhai Y, Shen Q, Sun L, Feng C, Rao J, Liu H, Zha X, Guo M, Ma D, Zhang Z, Li R, Xu H. A novel role of angiopoietin-like-3 associated with podocyte injury. Pediatr Res 2015; 77:732-9. [PMID: 25710887 DOI: 10.1038/pr.2015.38] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 11/05/2014] [Indexed: 12/29/2022]
Abstract
BACKGROUND Angiopoietin-like-3 (ANGPTL3) expression is increased in glomerular podocytes of nephrotic syndrome. We hypothesize whether ANGPTL3 plays an important role in podocyte injury and promoting proteinuria. METHODS Angptl3(+/+) and Angptl3(-/-) female mice on B6;129S5 gene background were injected with adriamycin by tail vein at the dose of 25 mg/Kg to produce nephropathy. Proteinuira was measured and podocytes ultrastructure was observed by electron microscopy. The interaction between ANGPTL3 and intergrin β3 was analyzed by CO-IP and confocal immunofluorescence. The relative gene and protein expression were analyzed by RT-PCR and western blot. RESULTS The deletion of ANGPTL3 tremendously attenuates proteinuria (more than a fivefold decrease in albuminuria) and protects podocytes from injury in a mouse model of adriamycin-induced nephropathy. We further demonstrate that ANGPTL3 interacts with and activates podocyte-expressed integrin β3 and regulate expression of α-actinin-4, which may result in the cytoskeletal rearrangement of podocytes. Additionally, we identify the activation of the ANGPTL3-integrin β3 signaling pathway in patients with nephrotic syndrome. CONCLUSION ANGPTL3 might play a crucial role in podocyte injury. Either decreasing ANGPTL3 expression or interfering with the ANGPTL3-integrin β3 interaction might be benefit for podocyte protection and decrease proteinuira.
Collapse
Affiliation(s)
- Junchao Liu
- Department of Nephrology and Rheumatology, Children's Hospital of Fudan University, Shanghai, China
| | - Xia Gao
- Department of Nephrology and Rheumatology, Children's Hospital of Fudan University, Shanghai, China
| | - Yihui Zhai
- Department of Nephrology and Rheumatology, Children's Hospital of Fudan University, Shanghai, China
| | - Qian Shen
- Department of Nephrology and Rheumatology, Children's Hospital of Fudan University, Shanghai, China
| | - Li Sun
- Department of Nephrology and Rheumatology, Children's Hospital of Fudan University, Shanghai, China
| | - Chun Feng
- Institute of Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Jia Rao
- Department of Nephrology and Rheumatology, Children's Hospital of Fudan University, Shanghai, China
| | - Haimei Liu
- Department of Nephrology and Rheumatology, Children's Hospital of Fudan University, Shanghai, China
| | - Xiliang Zha
- Department of Biochemistry and Molecular Biology, Shanghai Medical College of Fudan University, Shanghai, China
| | - Muyi Guo
- Department of Pathology and Key Laboratory of Molecular Medicine, Shanghai Medical College of Fudan University, Shanghai, China
| | - Duan Ma
- Institute of Biomedical Sciences, Fudan University, Shanghai, China
| | - Zhigang Zhang
- Department of Pathology and Key Laboratory of Molecular Medicine, Shanghai Medical College of Fudan University, Shanghai, China
| | - Ruixi Li
- Department of Anatomy, Histology and Embryology, Shanghai Medical College of Fudan University, Shanghai, China
| | - Hong Xu
- Department of Nephrology and Rheumatology, Children's Hospital of Fudan University, Shanghai, China
| |
Collapse
|
43
|
Travers T, Shao H, Joughin BA, Lauffenburger DA, Wells A, Camacho CJ. Tandem phosphorylation within an intrinsically disordered region regulates ACTN4 function. Sci Signal 2015; 8:ra51. [PMID: 26012634 PMCID: PMC4522051 DOI: 10.1126/scisignal.aaa1977] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Phosphorylated residues occur preferentially in the intrinsically disordered regions of eukaryotic proteins. In the disordered amino-terminal region of human α-actinin-4 (ACTN4), Tyr(4) and Tyr(31) are phosphorylated in cells stimulated with epidermal growth factor (EGF), and a mutant with phosphorylation-mimicking mutations of both tyrosines exhibits reduced interaction with actin in vitro. Cleavage of ACTN4 by m-calpain, a protease that in motile cells is predominantly activated at the rear, removes the Tyr(4) site. We found that introducing a phosphomimetic mutation at only Tyr(31) was sufficient to inhibit the interaction with actin in vitro. However, molecular dynamics simulations predicted that Tyr(31) is mostly buried and that phosphorylation of Tyr(4) would increase the solvent exposure and thus kinase accessibility of Tyr(31). In fibroblast cells, EGF stimulation increased tyrosine phosphorylation of a mutant form of ACTN4 with a phosphorylation-mimicking residue at Tyr(4), whereas a truncated mutant representing the product of m-calpain cleavage exhibited EGF-stimulated tyrosine phosphorylation at a background amount similar to that observed for a double phosphomimetic mutant of Tyr(4) and Tyr(31). We also found that inhibition of the receptor tyrosine kinases of the TAM family, such as AXL, blocked EGF-stimulated tyrosine phosphorylation of ACTN4. Mathematical modeling predicted that the kinetics of phosphorylation at Tyr(31) can be dictated by the kinase affinity for Tyr(4). This study suggests that tandem-site phosphorylation within intrinsically disordered regions provides a mechanism for a site to function as a switch to reveal a nearby function-regulating site.
Collapse
Affiliation(s)
- Timothy Travers
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Hanshuang Shao
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Brian A Joughin
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Douglas A Lauffenburger
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Alan Wells
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Carlos J Camacho
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, PA 15260, USA.
| |
Collapse
|
44
|
Shao H, Li S, Watkins SC, Wells A. α-Actinin-4 is required for amoeboid-type invasiveness of melanoma cells. J Biol Chem 2014; 289:32717-28. [PMID: 25296750 DOI: 10.1074/jbc.m114.579185] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
α-Actinin-4 (ACTN4), a key regulator of the actin cytoskeleton, is up-regulated in melanoma, though its role in melanoma remains speculative. We have discovered that in WM1158, a highly aggressive melanoma cell line, down-regulation of ACTN4 by shRNA induces a collagen I-dependent amoeboidal-to-mesenchymal transition. Re-expression of low levels of WT ACTN4 but not similar expression levels of ACTN1 successfully restores the amoeboidal morphology and limits collagen I gel compaction. A truncated ACTN4 mutant 1-890, which lacks the C-terminal tail, fails to rescue the amoeboidal morphology and to compact collagen I gel. Interestingly, in three-dimensional collagen I gels, ACTN4 KD cells are more polarized compared with cells in which scrambled shRNA is expressed. Surprisingly, ACTN4 KD cells migrate faster than the ones expressing the scrambled shRNA on a collagen I gel (two-dimensional) although these two cell lines migrate similarly on tissue culture. Most importantly, down-regulation of ACTN4 significantly reduced invasion of WM1158 cells into the three-dimensional collagen I gel, a representative of the dermis. Taken together, these findings suggest that ACTN4 plays an important role in maintaining the amoeboidal morphology of invasive melanoma and thus promoting dissemination through collagen-rich matrices.
Collapse
Affiliation(s)
| | - Shaoyan Li
- Shady Side Academy, Pittsburgh, Pennsylvania 15238, and
| | - Simon C Watkins
- Cell Biology and Physiology, and McGowan Institute of Regenerative Medicine, University of Pittsburgh, Pennsylvania 15213
| | - Alan Wells
- From the Departments of Pathology and the Laboratory and Pathology Service, Pittsburgh Veterans Affairs Health System, Pittsburgh, Pennsylvania 15213
| |
Collapse
|
45
|
Jefferson JA, Shankland SJ. The pathogenesis of focal segmental glomerulosclerosis. Adv Chronic Kidney Dis 2014; 21:408-16. [PMID: 25168829 DOI: 10.1053/j.ackd.2014.05.009] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 05/30/2014] [Indexed: 01/13/2023]
Abstract
Focal segmental glomerulosclerosis (FSGS) is a histologic pattern of injury on kidney biopsy that can arise from a diverse range of causes and mechanisms. Although primary and secondary forms are described based on the underlying cause, there are many common factors that underlie the development of this segmental injury. In this review, we will describe the currently accepted model for the pathogenesis of classic FSGS and review the data supporting this model. Although the podocyte is considered the major target of injury in FSGS, we will also highlight the contributions of other resident glomerular cells in the development of FSGS.
Collapse
|
46
|
Podocyte proteins in congenital and minimal change nephrotic syndrome. Clin Exp Nephrol 2014; 19:481-8. [PMID: 25117488 DOI: 10.1007/s10157-014-1020-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 07/31/2014] [Indexed: 12/17/2022]
Abstract
BACKGROUND Podocyte foot process effacement is a uniform finding in kidneys with heavy proteinuria. Its molecular mechanisms, however, are unsolved. We analyzed the expression of podocyte proteins in two kidney disorders: Congenital nephrotic syndrome of the Finnish type (CNF) and minimal change nephrotic syndrome (MCNS). METHODS Immunoperoxidase and immunofluorescence stainings were used to semiquantitatively analyze the expression of 13 and 4 podocyte proteins from different cellular compartments in CNF and MCNS, respectively. RESULTS The expression of a major slit diaphragm (SD) protein, Neph 1, showed a 46-fold decrease (p < 0.0001) in CNF kidneys as compared to controls. The three cytosolic adaptor proteins, podocin, NCK1/2, CD2AP, connecting SD proteins to the actin cytoskeleton were slightly upregulated (1.1-fold, 1.4-fold, and 3.3-fold, respectively). Also, the staining of the two actin-regulator proteins, ACTN4 and INF2, was modestly increased (2.2-fold and 1.7-fold, respectively, p < 0.0001). Staining for α3-integrin showed 1.9-fold increase (p < 0.0001) indicating that the major podocyte anchoring complex, α3β1, was well preserved in CNF glomeruli. In contrast to CNF kidneys, Neph1 FAT1, ACTN4, and CD2AP were quite normally expressed in proteinuric and non-proteinuric MCNS kidneys. CONCLUSION CNF kidneys lacking nephrin show decreased expression of other SD proteins but not cytosolic podocyte proteins involved in the foot process architecture or function. In MCNS kidneys, these changes in expression were not observed.
Collapse
|
47
|
Hodges JL, Vilchez SM, Asmussen H, Whitmore LA, Horwitz AR. α-Actinin-2 mediates spine morphology and assembly of the post-synaptic density in hippocampal neurons. PLoS One 2014; 9:e101770. [PMID: 25007055 PMCID: PMC4090192 DOI: 10.1371/journal.pone.0101770] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 06/10/2014] [Indexed: 11/18/2022] Open
Abstract
Dendritic spines are micron-sized protrusions that constitute the primary post-synaptic sites of excitatory neurotransmission in the brain. Spines mature from a filopodia-like protrusion into a mushroom-shaped morphology with a post-synaptic density (PSD) at its tip. Modulation of the actin cytoskeleton drives these morphological changes as well as the spine dynamics that underlie learning and memory. Several PSD molecules respond to glutamate receptor activation and relay signals to the underlying actin cytoskeleton to regulate the structural changes in spine and PSD morphology. α-Actinin-2 is an actin filament cross-linker, which localizes to dendritic spines, enriched within the post-synaptic density, and implicated in actin organization. We show that loss of α-actinin-2 in rat hippocampal neurons creates an increased density of immature, filopodia-like protrusions that fail to mature into a mushroom-shaped spine during development. α-Actinin-2 knockdown also prevents the recruitment and stabilization of the PSD in the spine, resulting in failure of synapse formation, and an inability to structurally respond to chemical stimulation of the N-methyl-D-aspartate (NMDA)-type glutamate receptor. The Ca2+-insensitive EF-hand motif in α-actinin-2 is necessary for the molecule's function in regulating spine morphology and PSD assembly, since exchanging it for the similar but Ca2+-sensitive domain from α-actinin-4, another α-actinin isoform, inhibits its function. Furthermore, when the Ca2+-insensitive domain from α-actinin-2 is inserted into α-actinin-4 and expressed in neurons, it creates mature spines. These observations support a model whereby α-actinin-2, partially through its Ca2+-insensitive EF-hand motif, nucleates PSD formation via F-actin organization and modulates spine maturation to mediate synaptogenesis.
Collapse
Affiliation(s)
- Jennifer L. Hodges
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
- * E-mail: (ARH); (JLH)
| | - Samuel Martin Vilchez
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
| | - Hannelore Asmussen
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
| | - Leanna A. Whitmore
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
| | - Alan Rick Horwitz
- Department of Cell Biology, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
- * E-mail: (ARH); (JLH)
| |
Collapse
|
48
|
Abstract
Nephrotic syndrome (NS) is characterized by heavy proteinuria, hypoalbuminemia, and edema. The underlying causes of NS are diverse and are tied to inheritable and environmental factors. A common diagnostic marker for NS is effacement of podocyte foot processes. The formation and maintenance of foot processes are under the control of many signalling molecules including Rho-GTPases. Our knowledge of Rho-GTPases is based largely on the functions of three prototypic members: RhoA, Rac1, and Cdc42. In the event of podocyte injury, the rearrangement to the actin cytoskeleton is orchestrated largely by this family of proteins. The importance of maintaining proper actin dynamics in podocytes has led to much investigation as to how Rho-GTPases and their regulatory molecules form and maintain foot processes as a critical component of the kidney’s filtration barrier. Modern sequencing techniques have allowed for the identification of novel disease causing mutations in genes such as ARHGDIA, encoding Rho-GDIα. Continued use of whole exome sequencing has the potential to lead to the identification of new mutations in genes encoding Rho-GTPases or their regulatory proteins. Expanding our knowledge of the dynamic regulation of the actin network by Rho-GTPases in podocytes will pave the way for effective therapeutic options for NS patients.
Collapse
|
49
|
Yang Y, Li D, Katirai F, Zhang B, Xu Y, Xiong P, Gong F, Zheng F. Basophil activation through ASGM1 stimulation triggers PAF release and anaphylaxis-like shock in mice. Eur J Immunol 2014; 44:2468-77. [DOI: 10.1002/eji.201344144] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 03/20/2014] [Accepted: 04/23/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Yan Yang
- Department of Immunology; Tongji Medical College; Huazhong University of Science and Technology; Wuhan China
- Laboratory of Infection and Immunity; Wuhan Institute of Virology; Chinese Academy of Sciences; Wuhan China
| | - Daling Li
- Department of Immunology; Tongji Medical College; Huazhong University of Science and Technology; Wuhan China
- Department of Anesthesiology; Wuhan Central Hospital; Wuhan China
| | - Foad Katirai
- Department of Immunology; Tongji Medical College; Huazhong University of Science and Technology; Wuhan China
- Clinical Medical School; Tongji Medical College; Huazhong University of Science and Technology; Wuhan China
| | - Bin Zhang
- Department of Immunology; Tongji Medical College; Huazhong University of Science and Technology; Wuhan China
| | - Yong Xu
- Department of Immunology; Tongji Medical College; Huazhong University of Science and Technology; Wuhan China
| | - Ping Xiong
- Department of Immunology; Tongji Medical College; Huazhong University of Science and Technology; Wuhan China
| | - Feili Gong
- Department of Immunology; Tongji Medical College; Huazhong University of Science and Technology; Wuhan China
| | - Fang Zheng
- Department of Immunology; Tongji Medical College; Huazhong University of Science and Technology; Wuhan China
| |
Collapse
|
50
|
Hall G, Rowell J, Farinelli F, Gbadegesin RA, Lavin P, Wu G, Homstad A, Malone A, Lindsey T, Jiang R, Spurney R, Tomaselli GF, Kass DA, Winn MP. Phosphodiesterase 5 inhibition ameliorates angiontensin II-induced podocyte dysmotility via the protein kinase G-mediated downregulation of TRPC6 activity. Am J Physiol Renal Physiol 2014; 306:F1442-50. [PMID: 24740790 DOI: 10.1152/ajprenal.00212.2013] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The emerging role of the transient receptor potential cation channel isotype 6 (TRPC6) as a central contributor to various pathological processes affecting podocytes has generated interest in the development of therapeutics to modulate its function. Recent insights into the regulation of TRPC6 have revealed PKG as a potent negative modulator of TRPC6 conductance and associated signaling via its phosphorylation at two highly conserved amino acid residues: Thr(69)/Thr(70) (Thr(69) in mice and Thr(70) in humans) and Ser(321)/Ser(322) (Ser(321) in mice and Ser(322) in humans). Here, we tested the role of PKG in modulating TRPC6-dependent responses in primary and conditionally immortalized mouse podocytes. TRPC6 was phosphorylated at Thr(69) in nonstimulated podocytes, but this declined upon ANG II stimulation or overexpression of constitutively active calcineurin phosphatase. ANG II induced podocyte motility in an in vitro wound assay, and this was reduced 30-60% in cells overexpressing a phosphomimetic mutant TRPC6 (TRPC6T70E/S322E) or activated PKG (P < 0.05). Pretreatment of podocytes with the PKG agonists S-nitroso-N-acetyl-dl-penicillamine (nitric oxide donor), 8-bromo-cGMP, Bay 41-2772 (soluble guanylate cyclase activator), or phosphodiesterase 5 (PDE5) inhibitor 4-{[3',4'-(methylenedioxy)benzyl]amino}[7]-6-methoxyquinazoline attenuated ANG II-induced Thr(69) dephosphorylation and also inhibited TRPC6-dependent podocyte motility by 30-60%. These data reveal that PKG activation strategies, including PDE5 inhibition, ameliorate ANG II-induced podocyte dysmotility by targeting TRPC6 in podocytes, highlighting the potential therapeutic utility of these approaches to treat hyperactive TRPC6-dependent glomerular disease.
Collapse
Affiliation(s)
- Gentzon Hall
- Division of Nephrology, Duke University Medical Center, Durham, North Carolina; Center for Human Genetics, Duke University Medical Center, Durham, North Carolina
| | - Janelle Rowell
- Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Federica Farinelli
- Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Rasheed A Gbadegesin
- Division of Nephrology, Duke University Medical Center, Durham, North Carolina; Center for Human Genetics, Duke University Medical Center, Durham, North Carolina; Department of Pediatrics, Duke University Medical Center, Durham, North Carolina; and
| | - Peter Lavin
- Trinity Health Kidney Centre, Tallaght Hospital, Trinity College, Dublin, Ireland
| | - Guanghong Wu
- Center for Human Genetics, Duke University Medical Center, Durham, North Carolina
| | - Alison Homstad
- Center for Human Genetics, Duke University Medical Center, Durham, North Carolina
| | - Andrew Malone
- Division of Nephrology, Duke University Medical Center, Durham, North Carolina; Center for Human Genetics, Duke University Medical Center, Durham, North Carolina
| | - Thomas Lindsey
- Center for Human Genetics, Duke University Medical Center, Durham, North Carolina
| | - Ruiji Jiang
- Center for Human Genetics, Duke University Medical Center, Durham, North Carolina
| | - Robert Spurney
- Division of Nephrology, Duke University Medical Center, Durham, North Carolina
| | - Gordon F Tomaselli
- Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - David A Kass
- Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Michelle P Winn
- Division of Nephrology, Duke University Medical Center, Durham, North Carolina; Center for Human Genetics, Duke University Medical Center, Durham, North Carolina;
| |
Collapse
|