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Gilhaus K, Cepok C, Kamm D, Surmann B, Nedvetsky PI, Emich J, Sundukova A, Saatkamp K, Nüsse H, Klingauf J, Wennmann DO, George B, Krahn MP, Pavenstädt HJ, Vollenbröker BA. Activation of Hippo Pathway Damages Slit Diaphragm by Deprivation of Ajuba Proteins. J Am Soc Nephrol 2023; 34:1039-1055. [PMID: 36930055 PMCID: PMC10278832 DOI: 10.1681/asn.0000000000000107] [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: 07/22/2022] [Accepted: 02/06/2023] [Indexed: 03/18/2023] Open
Abstract
SIGNIFICANCE STATEMENT Nuclear exclusion of the cotranscription factor YAP, which is a consequence of activation of the Hippo signaling pathway, leads to FSGS and podocyte apoptosis. Ajuba proteins play an important role in the glomerular filtration barrier by keeping the Hippo pathway inactive. In nephrocytes from Drosophila melanogaster , a well-established model system for podocyte research, Ajuba proteins ensure slit diaphragm (SD) formation and function. Hippo pathway activation leads to mislocalization of Ajuba proteins, decreased SD formation, rearrangement of the actin cytoskeleton, and increased SD permeability. Targeting the kinases of the Hippo pathway with specific inhibitors in the glomerulus could, therefore, be a promising strategy for therapy of FSGS. BACKGROUND The highly conserved Hippo pathway, which regulates organ growth and cell proliferation by inhibiting transcriptional cofactors YAP/TAZ, plays a special role in podocytes, where activation of the pathway leads to apoptosis. The Ajuba family proteins (Ajuba, LIM domain-containing protein 1 (LIMD1) and Wilms tumor protein 1-interacting protein [WTIP]) can bind and inactivate large tumor suppressor kinases 1 and 2, (LATS1/2) two of the Hippo pathway key kinases. WTIP, furthermore, connects the slit diaphragm (SD), the specialized cell-cell junction between podocytes, with the actin cytoskeleton. METHODS We used garland cell nephrocytes of Drosophila melanogaster to monitor the role of Ajuba proteins in Hippo pathway regulation and structural integrity of the SD. Microscopy and functional assays analyzed the interplay between Ajuba proteins and LATS2 regarding expression, localization, interaction, and effects on the functionality of the SD. RESULTS In nephrocytes, the Ajuba homolog Djub recruited Warts (LATS2 homolog) to the SD. Knockdown of Djub activated the Hippo pathway. Reciprocally, Hippo activation reduced the Djub level. Both Djub knockdown and Hippo activation led to morphological changes in the SD, rearrangement of the cortical actin cytoskeleton, and increased SD permeability. Knockdown of Warts or overexpression of constitutively active Yki prevented these effects. In podocytes, Hippo pathway activation or knockdown of YAP also decreased the level of Ajuba proteins. CONCLUSIONS Ajuba proteins regulate the structure and function of the SD in nephrocytes, connecting the SD protein complex to the actin cytoskeleton and maintaining the Hippo pathway in an inactive state. Hippo pathway activation directly influencing Djub expression suggests a self-amplifying feedback mechanism.
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Affiliation(s)
- Kevin Gilhaus
- Molecular Nephrology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - Claudia Cepok
- Molecular Nephrology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - David Kamm
- Molecular Nephrology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - Beate Surmann
- Molecular Nephrology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - Pavel I. Nedvetsky
- Medical Cell Biology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - Jana Emich
- Institute of Reproductive Genetics, University Hospital of Münster, Münster, Germany
| | - Alina Sundukova
- Molecular Nephrology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - Katharina Saatkamp
- Molecular Nephrology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - Harald Nüsse
- Institute of Medical Physics and Biophysics, Westfälische-Wilhelms University Münster, Münster, Germany
| | - Jürgen Klingauf
- Institute of Medical Physics and Biophysics, Westfälische-Wilhelms University Münster, Münster, Germany
| | - Dirk O. Wennmann
- Molecular Nephrology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - Britta George
- Molecular Nephrology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | - Michael P. Krahn
- Medical Cell Biology, Medical Clinic D, University Hospital of Münster, Münster, Germany
| | | | - Beate A. Vollenbröker
- Molecular Nephrology, Medical Clinic D, University Hospital of Münster, Münster, Germany
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Madhavan SM, Konieczkowski M, Bruggeman LA, DeWalt M, Nguyen JK, O'Toole JF, Sedor JR. Essential role of Wtip in mouse development and maintenance of the glomerular filtration barrier. Am J Physiol Renal Physiol 2022; 323:F272-F287. [PMID: 35862649 PMCID: PMC9394782 DOI: 10.1152/ajprenal.00051.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 07/12/2022] [Accepted: 07/13/2022] [Indexed: 11/22/2022] Open
Abstract
Wilms' tumor interacting protein (Wtip) has been implicated in cell junction assembly and cell differentiation and interacts with proteins in the podocyte slit diaphragm, where it regulates podocyte phenotype. To define Wtip expression and function in the kidney, we created a Wtip-deleted mouse model using β-galactosidase-neomycin (β-geo) gene trap technology. Wtip gene trap mice were embryonic lethal, suggesting additional developmental roles outside kidney function. Using β-geo heterozygous and normal mice, Wtip expression was identified in the developing kidneys, heart, and eyes. In the kidney, expression was restricted to podocytes, which appeared initially at the capillary loop stage coinciding with terminal podocyte differentiation. Heterozygous mice had an expected lifespan and showed no evidence of proteinuria or glomerular pathology. However, heterozygous mice were more susceptible to glomerular injury than wild-type littermates and developed more significant and prolonged proteinuria in response to lipopolysaccharide or adriamycin. In normal human kidneys, WTIP expression patterns were consistent with observations in mice and were lost in glomeruli concurrent with loss of synaptopodin expression in disease. Mechanistically, we identified the Rho guanine nucleotide exchange factor 12 (ARHGEF12) as a binding partner for WTIP. ARHGEF12 was expressed in human podocytes and formed high-affinity interactions through their LIM- and PDZ-binding domains. Our findings suggest that Wtip is essential for early murine embryonic development and maintaining normal glomerular filtration barrier function, potentially regulating slit diaphragm and foot process function through Rho effector proteins.NEW & NOTEWORTHY This study characterized dynamic expression patterns of Wilms' tumor interacting protein (Wtip) and demonstrates the novel role of Wtip in murine development and maintenance of the glomerular filtration barrier.
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Affiliation(s)
- Sethu M Madhavan
- Department of Medicine, The Ohio State University, Columbus, Ohio
| | | | - Leslie A Bruggeman
- Department of Inflammation and Immunity, Cleveland Clinic, Cleveland, Ohio
- Department of Nephrology, Cleveland Clinic, Cleveland, Ohio
| | - Megan DeWalt
- Department of Medicine, The Ohio State University, Columbus, Ohio
| | - Jane K Nguyen
- Department of Pathology, Cleveland Clinic, Cleveland, Ohio
| | - John F O'Toole
- Department of Inflammation and Immunity, Cleveland Clinic, Cleveland, Ohio
- Department of Nephrology, Cleveland Clinic, Cleveland, Ohio
| | - John R Sedor
- Department of Inflammation and Immunity, Cleveland Clinic, Cleveland, Ohio
- Department of Nephrology, Cleveland Clinic, Cleveland, Ohio
- Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio
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Rauskolb C, Han A, Kirichenko E, Ibar C, Irvine KD. Analysis of the Drosophila Ajuba LIM protein defines functions for distinct LIM domains. PLoS One 2022; 17:e0269208. [PMID: 35969522 PMCID: PMC9377591 DOI: 10.1371/journal.pone.0269208] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 08/01/2022] [Indexed: 01/27/2023] Open
Abstract
The Ajuba LIM protein Jub mediates regulation of Hippo signaling by cytoskeletal tension through interaction with the kinase Warts and participates in feedback regulation of junctional tension through regulation of the cytohesin Steppke. To investigate how Jub interacts with and regulates its distinct partners, we investigated the ability of Jub proteins missing different combinations of its three LIM domains to rescue jub phenotypes and to interact with α-catenin, Warts and Steppke. Multiple regions of Jub contribute to its ability to bind α-catenin and to localize to adherens junctions in Drosophila wing imaginal discs. Co-immunoprecipitation experiments in cultured cells identified a specific requirement for LIM2 for binding to Warts. However, in vivo, both LIM1 and LIM2, but not LIM3, were required for regulation of wing growth, Yorkie activity, and Warts localization. Conversely, LIM2 and LIM3, but not LIM1, were required for regulation of cell shape and Steppke localization in vivo, and for maximal Steppke binding in co-immunoprecipitation experiments. These observations identify distinct functions for the different LIM domains of Jub.
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Affiliation(s)
- Cordelia Rauskolb
- Waksman Institute and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ, United States of America
| | - Ahri Han
- Waksman Institute and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ, United States of America
| | - Elmira Kirichenko
- Waksman Institute and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ, United States of America
| | - Consuelo Ibar
- Waksman Institute and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ, United States of America
| | - Kenneth D. Irvine
- Waksman Institute and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway, NJ, United States of America
- * E-mail:
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4
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Weatherly SM, Collin GB, Charette JR, Stone L, Damkham N, Hyde LF, Peterson JG, Hicks W, Carter GW, Naggert JK, Krebs MP, Nishina PM. Identification of Arhgef12 and Prkci as genetic modifiers of retinal dysplasia in the Crb1rd8 mouse model. PLoS Genet 2022; 18:e1009798. [PMID: 35675330 PMCID: PMC9212170 DOI: 10.1371/journal.pgen.1009798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 06/21/2022] [Accepted: 05/03/2022] [Indexed: 12/03/2022] Open
Abstract
Mutations in the apicobasal polarity gene CRB1 lead to diverse retinal diseases, such as Leber congenital amaurosis, cone-rod dystrophy, retinitis pigmentosa (with and without Coats-like vasculopathy), foveal retinoschisis, macular dystrophy, and pigmented paravenous chorioretinal atrophy. Limited correlation between disease phenotypes and CRB1 alleles, and evidence that patients sharing the same alleles often present with different disease features, suggest that genetic modifiers contribute to clinical variation. Similarly, the retinal phenotype of mice bearing the Crb1 retinal degeneration 8 (rd8) allele varies with genetic background. Here, we initiated a sensitized chemical mutagenesis screen in B6.Cg-Crb1rd8/Pjn, a strain with a mild clinical presentation, to identify genetic modifiers that cause a more severe disease phenotype. Two models from this screen, Tvrm266 and Tvrm323, exhibited increased retinal dysplasia. Genetic mapping with high-throughput exome and candidate-gene sequencing identified causative mutations in Arhgef12 and Prkci, respectively. Epistasis analysis of both strains indicated that the increased dysplastic phenotype required homozygosity of the Crb1rd8 allele. Retinal dysplastic lesions in Tvrm266 mice were smaller and caused less photoreceptor degeneration than those in Tvrm323 mice, which developed an early, large diffuse lesion phenotype. At one month of age, Müller glia and microglia mislocalization at dysplastic lesions in both modifier strains was similar to that in B6.Cg-Crb1rd8/Pjn mice but photoreceptor cell mislocalization was more extensive. External limiting membrane disruption was comparable in Tvrm266 and B6.Cg-Crb1rd8/Pjn mice but milder in Tvrm323 mice. Immunohistological analysis of mice at postnatal day 0 indicated a normal distribution of mitotic cells in Tvrm266 and Tvrm323 mice, suggesting normal early development. Aberrant electroretinography responses were observed in both models but functional decline was significant only in Tvrm323 mice. These results identify Arhgef12 and Prkci as modifier genes that differentially shape Crb1-associated retinal disease, which may be relevant to understanding clinical variability and underlying disease mechanisms in humans. Inherited eye diseases affect roughly 1:1,000 individuals worldwide. Although these diseases are often linked to variants of a single gene, it is increasingly recognized that a second variant in other genes may modify disease characteristics, including age of onset, severity, and lesion appearance. Identifying such modifier genes in humans is difficult. In this study, two modifiers of a gene associated with retinal damage leading to childhood blindness in humans (CRB1) were identified in mice. Retinal damage caused by Crb1 mutation alone was less severe than in the presence of Arhgef12 or Prkci mutations. Furthermore, the modifier gene mutations caused retinal damage only in the presence of the Crb1 mutation. Our results point to a role of mouse Crb1 and the modifying effects of Arhgef12 and Prkci in a biological network that controls adhesive interactions between cells. The variation in disease severity, lesion appearance, and visual responses in these mice provide a dramatic example of modifier gene influence. This work may lead to an improved understanding of the molecular basis of CRB1-associated retinal disease, with possible relevance to diagnostic and therapeutic intervention in humans.
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Affiliation(s)
| | - Gayle B. Collin
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | | | - Lisa Stone
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | - Nattaya Damkham
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
- Graduate Program in Immunology, Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
- Siriraj Center of Excellence for Stem Cell Research, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Lillian F. Hyde
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | | | - Wanda Hicks
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | | | | | - Mark P. Krebs
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
- * E-mail: (MPK); (PMN)
| | - Patsy M. Nishina
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
- * E-mail: (MPK); (PMN)
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5
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Doucette LP, Noel NCL, Zhai Y, Xu M, Caluseriu O, Hoang SC, Radziwon AJ, MacDonald IM. Whole exome sequencing reveals putatively novel associations in retinopathies and drusen formation. Eur J Hum Genet 2021; 29:1171-1185. [PMID: 33776059 PMCID: PMC8385108 DOI: 10.1038/s41431-021-00872-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 01/24/2021] [Accepted: 03/12/2021] [Indexed: 02/02/2023] Open
Abstract
Inherited retinal dystrophies (IRDs) affect 1 in 3000 individuals worldwide and are genetically heterogeneous, with over 270 identified genes and loci; however, there are still many identified disorders with no current genetic etiology. Whole exome sequencing (WES) provides a hypothesis-free first examination of IRD patients in either a clinical or research setting to identify the genetic cause of disease. We present a study of IRD in ten families from Alberta, Canada, through the lens of novel gene discovery. We identify the genetic etiology of IRDs in three of the families to be variants in known disease-associated genes, previously missed by clinical investigations. In addition, we identify two potentially novel associations: LRP1 in early-onset drusen formation and UBE2U in a multi-system condition presenting with retinoschisis, cataracts, learning disabilities, and developmental delay. We also describe interesting results in our unsolved cases to provide further information to other investigators of these blinding conditions.
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Affiliation(s)
- Lance P Doucette
- Department of Ophthalmology & Visual Sciences, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Nicole C L Noel
- Department of Medical Genetics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Yi Zhai
- Department of Ophthalmology & Visual Sciences, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Manlong Xu
- Department of Ophthalmology & Visual Sciences, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Oana Caluseriu
- Department of Medical Genetics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Stephanie C Hoang
- Department of Medical Genetics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Alina J Radziwon
- Department of Medical Genetics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Ian M MacDonald
- Department of Ophthalmology & Visual Sciences, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada.
- Department of Medical Genetics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada.
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6
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Matsuda J, Asano-Matsuda K, Kitzler TM, Takano T. Rho GTPase regulatory proteins in podocytes. Kidney Int 2020; 99:336-345. [PMID: 33122025 DOI: 10.1016/j.kint.2020.08.035] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 08/21/2020] [Accepted: 08/25/2020] [Indexed: 12/14/2022]
Abstract
The Rho family of small GTPases (Rho GTPases) are the master regulators of the actin cytoskeleton and consist of 22 members. Previous studies implicated dysregulation of Rho GTPases in podocytes in the pathogenesis of proteinuric glomerular diseases. Rho GTPases are primarily regulated by the three families of proteins; guanine nucleotide exchange factors (GEFs; 82 members), GTPase-activating proteins (GAPs; 69 members), and GDP dissociation inhibitors (GDIs; 3 members). Since the regulatory proteins far outnumber their substrate Rho GTPases and act in concert in a cell/context-dependent manner, the upstream regulatory mechanism directing Rho GTPases in podocytes is largely unknown. In this review, we summarize recent advances in the understanding of the role of Rho GTPase regulatory proteins in podocytes, including the known mutations of these proteins that cause proteinuria in humans. We also provide critical appraisal of the in vivo and in vitro studies and identify the knowledge gap in the field that will require further studies.
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Affiliation(s)
- Jun Matsuda
- Division of Nephrology, McGill University Health Centre, Montreal, Quebec, Canada; Research Institute, McGill University Health Centre, Montreal, Quebec, Canada
| | - Kana Asano-Matsuda
- Division of Nephrology, McGill University Health Centre, Montreal, Quebec, Canada; Research Institute, McGill University Health Centre, Montreal, Quebec, Canada
| | - Thomas M Kitzler
- Research Institute, McGill University Health Centre, Montreal, Quebec, Canada; Division of Medical Genetics, Department of Medicine, McGill University Health Centre, Montreal, Quebec, Canada; Department of Human Genetics, McGill University, Montreal, Quebec, Canada
| | - Tomoko Takano
- Division of Nephrology, McGill University Health Centre, Montreal, Quebec, Canada; Research Institute, McGill University Health Centre, Montreal, Quebec, Canada.
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Gizer M, Köse S, Karaosmanoglu B, Taskiran EZ, Berkkan A, Timuçin M, Korkusuz F, Korkusuz P. The Effect of Boron-Containing Nano-Hydroxyapatite on Bone Cells. Biol Trace Elem Res 2020; 193:364-376. [PMID: 31069715 DOI: 10.1007/s12011-019-01710-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 03/27/2019] [Indexed: 02/02/2023]
Abstract
Metabolic diseases or injuries damage bone structure and self-renewal capacity. Trace elements and hydroxyapatite crystals are important in the development of biomaterials to support the renewal of bone extracellular matrix. In this study, it was assumed that the boron-loaded nanometer-sized hydroxyapatite composite supports the construction of extracellular matrix by controlled boron release in order to prevent its toxic effect. In this context, boron release from nanometer-sized hydroxyapatite was calculated by ICP-MS as in large proportion within 1 h and continuing release was provided at a constant low dose. The effect of the boron-containing nanometer-sized hydroxyapatite composite on the proliferation of SaOS-2 osteoblasts and human bone marrow-derived mesenchymal stem cells was evaluated by WST-1 and compared with the effects of nano-hydroxyapatite and boric acid. Boron increased proliferation of mesenchymal stem cells at high doses and exhibited different effects on osteoblastic cell proliferation. Boron-containing nano-hydroxyapatite composites increased osteogenic differentiation of mesenchymal stem cells by increasing alkaline phosphatase activity, when compared to nano-hydroxyapatite composite and boric acid. The molecular mechanism of effective dose of boron-containing hydroxyapatite has been assessed by transcriptomic analysis and shown to affect genes involved in Wnt, TGF-β, and response to stress signaling pathways when compared to nano-hydroxyapatite composite and boric acid. Finally, a safe osteoconductive dose range of boron-containing nano-hydroxyapatite composites for local repair of bone injuries and the molecular effect profile in the effective dose should be determined by further studies to validation of the regenerative therapeutic effect window.
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Affiliation(s)
- Merve Gizer
- Graduate School of Science and Engineering, Department of Bioengineering, Hacettepe University, Ankara, Turkey
| | - Sevil Köse
- Faculty of Medicine, Department of Medical Biology, Atilim University, Ankara, Turkey
| | - Beren Karaosmanoglu
- Department of Medical Genetics, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Ekim Z Taskiran
- Department of Medical Genetics, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Aysel Berkkan
- Department of Analytical Chemistry, Gazi University Faculty of Pharmacy, Ankara, Turkey
| | - Muharrem Timuçin
- Department of Metallurgical and Materials Engineering, Middle East Technical University Faculty of Engineering, Ankara, Turkey
| | - Feza Korkusuz
- Department of Sports Medicine, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Petek Korkusuz
- Department of Histology and Embryology, Hacettepe University Faculty of Medicine, 06100 Sihhiye, Ankara, Turkey.
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Mao J, Tian Y, Wang C, Jiang K, Li R, Yao Y, Zhang R, Sun D, Liang R, Gao Z, Wang Q, Wang L. CBX2 Regulates Proliferation and Apoptosis via the Phosphorylation of YAP in Hepatocellular Carcinoma. J Cancer 2019; 10:2706-2719. [PMID: 31258779 PMCID: PMC6584921 DOI: 10.7150/jca.31845] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 05/09/2019] [Indexed: 12/29/2022] Open
Abstract
Chromobox 2 (CBX2), a chromobox family protein, is a crucial component of the polycomb group complex: polycomb repressive complex 1 (PRC1). Research on CBX2 as an oncogene has been published in recent years. However, the connection between CBX2 and hepatocellular carcinoma (HCC) has not been studied. In this article, based on the results of immunohistochemical (IHC) staining of HCC and adjacent liver tissue microarrays, we found that high CBX2 expression is associated with poor prognosis in HCC patients. The results of a CCK8 assay, a clonogenic survival assay and a nude mouse tumorigenicity assay showed that knockdown of CBX2 inhibited the proliferation of HCC cells. According to the results of Annexin V-FITC/propidium iodide (PI) staining-based fluorescence activated cell sorting (FACS) analysis, knockdown of CBX2 increased HCC cell apoptosis. Furthermore, the RNA-seq results revealed that knockdown of CBX2 inhibited the expression of WTIP, which is an inhibitor of the Hippo pathway. We used western blotting to validate the mechanism and discovered that knockdown of CBX2 increased the phosphorylation of YAP, which explains why knockdown of CBX2 inhibits proliferation and increases apoptosis in HCC cells. In conclusion, CBX2 could be a potential target for HCC anticancer treatment.
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Affiliation(s)
- Jiakai Mao
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Yu Tian
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China.,Department of Vascular Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Chengye Wang
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Keqiu Jiang
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Rui Li
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Yifan Yao
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Rixin Zhang
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Deguang Sun
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Rui Liang
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Zhenming Gao
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Qi Wang
- Department of Pulmonary Medicine, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Liming Wang
- Division of Hepatobiliary and Pancreatic Surgery, Department of General Surgery, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
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Comprehensive and Systematic Analysis of Gene Expression Patterns Associated with Body Mass Index. Sci Rep 2019; 9:7447. [PMID: 31092860 PMCID: PMC6520409 DOI: 10.1038/s41598-019-43881-5] [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: 10/15/2018] [Accepted: 04/29/2019] [Indexed: 12/20/2022] Open
Abstract
Both genetic and environmental factors are suggested to influence overweight and obesity risks. Although individual loci and genes have been frequently shown to be associated with body mass index (BMI), the overall interaction of these genes and their role in BMI remains underexplored. Data were collected in 90 healthy, predominately Caucasian participants (51% female) with a mean age of 26.00 ± 9.02 years. Whole blood samples were assayed by Affymetrix GeneChip Human Genome U133 Plus 2.0 Array. We integrated and analyzed the clinical and microarray gene expression data from those individuals to understand various systematic gene expression patterns underlying BMI. Conventional differential expression analysis identified seven genes RBM20, SEPT12, AX748233, SLC30A3, WTIP, CASP10, and OR12D3 associated with BMI. Weight gene co-expression network analysis among 4,647 expressed genes identified two gene modules associated with BMI. These two modules, with different extents of gene connectivity, are enriched for catabolic and muscle system processes respectively, and tend to be regulated by zinc finger transcription factors. A total of 246 hub genes were converted to non-hub genes, and 286 non-hub genes were converted to hub genes between normal and overweight individuals, revealing the network dynamics underlying BMI. A total of 28 three-way gene interactions were identified, suggesting the existence of high-order gene expression patterns underlying BMI. Our study demonstrated a variety of systematic gene expression patterns associated with BMI and thus provided novel understanding regarding the genetic factors for overweight and obesity risks on system levels.
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Wu Z, Qiu M, Mi Z, Meng M, Guo Y, Jiang X, Fang J, Wang H, Zhao J, Liu Z, Qian D, Yuan Z. WT1-interacting protein inhibits cell proliferation and tumorigenicity in non-small-cell lung cancer via the AKT/FOXO1 axis. Mol Oncol 2019; 13:1059-1074. [PMID: 30690883 PMCID: PMC6487700 DOI: 10.1002/1878-0261.12462] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 01/07/2019] [Accepted: 01/10/2019] [Indexed: 01/22/2023] Open
Abstract
Lung cancer is the most common cancer and the leading cause of cancer‐related death worldwide; hence, it is imperative that the mechanisms underlying the malignant properties of lung cancer be uncovered in order to efficiently treat this disease. Increasing evidence has shown that WT1‐interacting protein (WTIP) plays important roles both physiologically and pathologically in humans; however, the role of WTIP in cancer is unknown. Here, we investigated the role and mechanism of WTIP in cell proliferation and tumorigenesis of non‐small‐cell lung cancer (NSCLC). We report that WTIP is a tumor suppressor in human NSCLC. We found that WTIP expression was significantly reduced in both NSCLC cell lines and clinical specimens compared to that in normal controls; this reduction was largely attributed to promoter hypermethylation. Downregulation of WTIP significantly correlates with poor prognosis and predicts a shorter overall survival and progression‐free survival among NSCLC patients. Moreover, ectopic overexpression of WTIP dramatically inhibits cell proliferation and tumorigenesis in vitro and in vivo; conversely, depletion of WTIP expression shows the opposite effects. Mechanistically, WTIP impairs AKT phosphorylation and activation, leading to enhanced expression and transcriptional activity of FOXO1, which further increases p21Cip1 and p27Kip1, and decreases cyclin D1, which consequently results in cell cycle arrest. Collectively, the results of the current study indicate that WTIP is an important proliferation‐related gene and that WTIP expression may represent a novel prognostic biomarker for NSCLC.
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Affiliation(s)
- Zhiqiang Wu
- Department of Radiation Oncology, Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute & Hospital, China
| | - Minghan Qiu
- Department of Radiation Oncology, Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute & Hospital, China.,Department of Oncology, Tianjin Union Medical Center, China
| | - Zeyun Mi
- Department of Biochemistry and Molecular Biology, College of Basic Medical Science, Tianjin Medical University, China
| | - Maobin Meng
- Department of Radiation Oncology, Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute & Hospital, China
| | - Yu Guo
- Department of General Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xiangli Jiang
- Department of Thoracic Medical Oncology, Tianjin Medical University Cancer Institute & Hospital, China
| | | | - Hui Wang
- Department of Radiation Oncology, Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute & Hospital, China
| | - Jinlin Zhao
- Department of Radiation Oncology, Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute & Hospital, China
| | - Zhuang Liu
- Department of Radiation Oncology, Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute & Hospital, China
| | - Dong Qian
- Department of Radiation Oncology, Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute & Hospital, China
| | - Zhiyong Yuan
- Department of Radiation Oncology, Key Laboratory of Cancer Prevention and Therapy, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute & Hospital, China
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11
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Chu CW, Xiang B, Ossipova O, Ioannou A, Sokol SY. The Ajuba family protein Wtip regulates actomyosin contractility during vertebrate neural tube closure. J Cell Sci 2018; 131:jcs.213884. [PMID: 29661847 DOI: 10.1242/jcs.213884] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 04/06/2018] [Indexed: 12/16/2022] Open
Abstract
Ajuba family proteins are implicated in the assembly of cell junctions and have been reported to antagonize Hippo signaling in response to cytoskeletal tension. To assess the role of these proteins in actomyosin contractility, we examined the localization and function of Wtip, a member of the Ajuba family, in Xenopus early embryos. Targeted in vivo depletion of Wtip inhibited apical constriction in neuroepithelial cells and elicited neural tube defects. Fluorescent protein-tagged Wtip showed predominant punctate localization along the cell junctions in the epidermis and a linear junctional pattern in the neuroectoderm. In cells undergoing Shroom3-induced apical constriction, the punctate distribution was reorganized into a linear pattern. Conversely, the linear junctional pattern of Wtip in neuroectoderm changed to a more punctate distribution in cells with reduced myosin II activity. The C-terminal fragment of Wtip physically associated with Shroom3 and interfered with Shroom3 activity and neural fold formation. We therefore propose that Wtip is a tension-sensitive cytoskeletal adaptor that regulates apical constriction during vertebrate neurulation.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Chih-Wen Chu
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Bo Xiang
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Olga Ossipova
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Andriani Ioannou
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Sergei Y Sokol
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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12
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Ibar C, Kirichenko E, Keepers B, Enners E, Fleisch K, Irvine KD. Tension-dependent regulation of mammalian Hippo signaling through LIMD1. J Cell Sci 2018; 131:jcs214700. [PMID: 29440237 PMCID: PMC5897721 DOI: 10.1242/jcs.214700] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 01/31/2018] [Indexed: 12/26/2022] Open
Abstract
Hippo signaling is regulated by biochemical and biomechanical cues that influence the cytoskeleton, but the mechanisms that mediate this have remained unclear. We show that all three mammalian Ajuba family proteins - AJUBA, LIMD1 and WTIP - exhibit tension-dependent localization to adherens junctions, and that both LATS family proteins, LATS1 and LATS2, exhibit an overlapping tension-dependent junctional localization. This localization of Ajuba and LATS family proteins is also influenced by cell density, and by Rho activation. We establish that junctional localization of LATS kinases requires LIMD1, and that LIMD1 is also specifically required for the regulation of LATS kinases and YAP1 by Rho. Our results identify a biomechanical pathway that contributes to regulation of mammalian Hippo signaling, establish that this occurs through tension-dependent LIMD1-mediated recruitment and inhibition of LATS kinases in junctional complexes, and identify roles for this pathway in both Rho-mediated and density-dependent regulation of Hippo signaling.
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Affiliation(s)
- Consuelo Ibar
- Waksman Institute and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway NJ 08854, USA
| | - Elmira Kirichenko
- Waksman Institute and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway NJ 08854, USA
| | - Benjamin Keepers
- Waksman Institute and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway NJ 08854, USA
| | - Edward Enners
- Waksman Institute and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway NJ 08854, USA
| | - Katelyn Fleisch
- Waksman Institute and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway NJ 08854, USA
| | - Kenneth D Irvine
- Waksman Institute and Department of Molecular Biology and Biochemistry, Rutgers University, Piscataway NJ 08854, USA
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13
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Krüger-Genge A, Fuhrmann R, Jung F, Franke RP. Morphology of primary human venous endothelial cell cultures before and after culture medium exchange. Clin Hemorheol Microcirc 2016; 61:151-6. [PMID: 26410871 DOI: 10.3233/ch-151992] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The evaluation of the interaction of human, venous endothelial cells (HUVEC) with body foreign materials on the cellular level cannot be performed in vivo, but is investigated in vitro under standard culture conditions. To maintain the vitality, proliferation and morphology of HUVEC seeded on body foreign substrates over days, the cell culture medium is usually exchanged every second day. It is well known, that alterations in the microenvironment of cells bear the risk of influencing cell morphology and function. In the current study the influence of cell culture medium exchange on HUVEC cytoskeletal microfilament structure and function was investigated. MATERIAL AND METHODS HUVEC in the third passage were seeded on extracellular matrix (ECM) - which was secreted from bovine corneal endothelial cells on glass- until functional confluence was reached. The experiment started 11 days after HUVEC seeding with an exchange of the cell culture medium followed by a staining of the actin microfilaments with phalloidin-rhodamin 1.5 and 5 minutes after medium exchange. The microfilaments were documented by use of an Olympus microscope (IMT-2) equipped with a UV lamp and online connected to a TV chain (Sony XC 50 ST/monochrome) implying an OPTIMAS - Image analysis system. Prostacyclin was analysed in the cell culture supernatant. RESULTS 1.5 min after culture medium exchange in the functionally confluent cultures a slight disturbance of the actin microfilament structure with a broadening of the marginal filament band, a partial disconnection of cell-cell contacts and the appearance of intercellular fenestrations were observed. 5 minutes after medium exchange a redevelopment of the slightly disturbed microfilament structure with a condensation and narrowing of the marginal filament band was seen. 12 h later a further consolidation of the microfilament structure occurred. In addition, a perturbation of the cultured HUVEC occurred after cell culture medium exchange. The prostacyclin concentration in the supernatant increased significantly after 1.5 min to 466 ± 543 pg·mL-1 (p < 0.001) and after 5 min to 408 ± 458 pg·mL-1 (p < 0.001), while in control cells the prostacyclin concentration did not change remaining in the range of 50 ± 48.9 pg·mL-1. CONCLUSION This study revealed that the exchange of the cell culture medium led to a rapid disturbance of the HUVEC with stress fiber formation, disconnection of cell-cell contacts and an altered prostacyclin secretion, which had regressed nearly completely after 12 hours. Therefore, the evaluation of HUVEC on body foreign materials should be performed not earlier than 12 hours after cell culture medium exchange to avoid a misinterpretation of the endothelial cell morphological state. This procedure minimizes the risk of a misinterpretation of the endothelial cell morphology - caused by the culture medium exchange and not by the interaction between biomaterials and HUVEC.
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Affiliation(s)
- A Krüger-Genge
- Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Teltow, Germany
| | - R Fuhrmann
- Abteilung Biomaterialien, Zentralinstitut für Biomedizinische Technik, Universität Ulm, Albert-Einstein-Allee, Ulm, Germany
| | - F Jung
- Institute of Biomaterial Science and Berlin-Brandenburg Center for Regenerative Therapies, Helmholtz-Zentrum Geesthacht, Teltow, Germany
| | - R P Franke
- Abteilung Biomaterialien, Zentralinstitut für Biomedizinische Technik, Universität Ulm, Albert-Einstein-Allee, Ulm, Germany
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14
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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.
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Affiliation(s)
- Alan R Parrish
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, MO 65212, USA.
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15
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Keyvani Chahi A, Martin CE, Jones N. Nephrin Suppresses Hippo Signaling through the Adaptor Proteins Nck and WTIP. J Biol Chem 2016; 291:12799-12808. [PMID: 27033705 DOI: 10.1074/jbc.m116.724245] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Indexed: 11/06/2022] Open
Abstract
Podocytes are key components of the kidney blood filtration barrier, and their ability to withstand hemodynamic strain is proposed to be closely tied to their unique and flexible cytoarchitecture. However, the mechanisms that control such mechanotransduction are poorly understood. We have previously established that tyrosine phosphorylation of the transmembrane protein nephrin promotes recruitment of the Nck1/2 cytoskeletal adaptor proteins and downstream actin remodeling. We now reveal that Nck integrates nephrin with the Hippo kinase cascade through association with the adaptor protein WTIP. Using mutational analysis, we show that Nck sequesters WTIP and its binding partner Lats1 to phosphorylated nephrin, resulting in decreased phospho-activation of Lats1. We further demonstrate that, coincident with nephrin dephosphorylation in a transient model of podocyte injury in mice, Lats1 is rapidly activated, and this precedes significant down-regulation of the transcription regulator Yap. Moreover, we show reduced levels of Yap protein in mice with chronic disruption of nephrin phospho-signaling. Together, these findings support the existence of a dynamic molecular link between nephrin signaling and the canonical Hippo pathway in podocytes, which may facilitate the conversion of mechanical cues to biochemical signals promoting podocyte viability.
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Affiliation(s)
- Ava Keyvani Chahi
- From the Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Claire E Martin
- From the Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Nina Jones
- From the Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
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16
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Abstract
Podocytes are highly specialized cells of the kidney glomerulus that wrap around capillaries and that neighbor cells of the Bowman’s capsule. When it comes to glomerular filtration, podocytes play an active role in preventing plasma proteins from entering the urinary ultrafiltrate by providing a barrier comprising filtration slits between foot processes, which in aggregate represent a dynamic network of cellular extensions. Foot processes interdigitate with foot processes from adjacent podocytes and form a network of narrow and rather uniform gaps. The fenestrated endothelial cells retain blood cells but permit passage of small solutes and an overlying basement membrane less permeable to macromolecules, in particular to albumin. The cytoskeletal dynamics and structural plasticity of podocytes as well as the signaling between each of these distinct layers are essential for an efficient glomerular filtration and thus for proper renal function. The genetic or acquired impairment of podocytes may lead to foot process effacement (podocyte fusion or retraction), a morphological hallmark of proteinuric renal diseases. Here, we briefly discuss aspects of a contemporary view of podocytes in glomerular filtration, the patterns of structural changes in podocytes associated with common glomerular diseases, and the current state of basic and clinical research.
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Affiliation(s)
- Jochen Reiser
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA
| | - Mehmet M Altintas
- Department of Medicine, Rush University Medical Center, Chicago, IL, USA
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17
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Zhang Y, Wang H, Li Y, Xu D, Lu L. Molecular cloning and expression analysis of the Ajuba gene of grass carp (Ctenopharyngodon idella) involved in cellular response to viral infection. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2015; 48:164-170. [PMID: 25452047 DOI: 10.1016/j.dci.2014.10.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 10/06/2014] [Accepted: 10/06/2014] [Indexed: 06/04/2023]
Abstract
Ajuba belongs to the LIM domain proteins, which are involved in the assembly of the extracellular matrix and, along with associated proteins, regulate target genes that connect the extracellular matrix and the cytoskeleton. In the present study, we characterized the entire cDNA sequence of the Ajuba gene from grass carp (gcAjuba). The gcAjuba cDNA contained an open reading frame (ORF) of 2121 bp encoding a polypeptide of 706 amino acids with an estimated molecular mass of 75.966 kDa and three LIM domains in the C-terminal. The transcriptional level of gcAjuba was significantly up-regulated following the stimulation of virus in vitro. Sub-cellular location of gcAjuba and GCRV-JX01 NS26 proteins did not overlap in the cytoplasm and no direct interaction between gcAjuba and the protein NS26 was detected by co-immunoprecipitation (CO-IP) test in grass carp kidney cells. Based on these results, the gcAjuba is determined to be an immediately inducible gene responding to viral infection and in vivo association of gcAjuba with NS26 could not be confirmed, which has been suggested by yeast two-hybrid assay in previous report.
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Affiliation(s)
- Yanan Zhang
- Key Laboratory of Freshwater Fishery Germplasm Resources, Ministry of Agriculture of P. R. China, Shanghai Ocean University, Shanghai 201306, China
| | - Hao Wang
- Key Laboratory of Freshwater Fishery Germplasm Resources, Ministry of Agriculture of P. R. China, Shanghai Ocean University, Shanghai 201306, China
| | - Yan Li
- Key Laboratory of Freshwater Fishery Germplasm Resources, Ministry of Agriculture of P. R. China, Shanghai Ocean University, Shanghai 201306, China
| | - Dan Xu
- Key Laboratory of Freshwater Fishery Germplasm Resources, Ministry of Agriculture of P. R. China, Shanghai Ocean University, Shanghai 201306, China
| | - Liqun Lu
- Key Laboratory of Freshwater Fishery Germplasm Resources, Ministry of Agriculture of P. R. China, Shanghai Ocean University, Shanghai 201306, China.
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18
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Mouawad F, Aoudjit L, Jiang R, Szaszi K, Takano T. Role of guanine nucleotide exchange factor-H1 in complement-mediated RhoA activation in glomerular epithelial cells. J Biol Chem 2013; 289:4206-18. [PMID: 24356971 DOI: 10.1074/jbc.m113.506816] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Visceral glomerular epithelial cells (GEC), also known as podocytes, are vital for the structural and functional integrity of the glomerulus. The actin cytoskeleton plays a central role in maintaining GEC morphology. In a rat model of experimental membranous nephropathy (passive Heymann nephritis (PHN)), complement C5b-9-induced proteinuria was associated with the activation of the actin regulator small GTPase, RhoA. The mechanisms of RhoA activation, however, remained unknown. In this study, we explored the role of the epithelial guanine nucleotide exchange factor, GEF-H1, in complement-induced RhoA activation. Using affinity precipitation to monitor GEF activity, we found that GEF-H1 was activated in glomeruli isolated from rats with PHN. Complement C5b-9 also induced parallel activation of GEF-H1 and RhoA in cultured GEC. In GEC in which GEF-H1 was knocked down, both basal and complement-induced RhoA activity was reduced. On the other hand, GEF-H1 knockdown augmented complement-mediated cytolysis, suggesting a role for GEF-H1 and RhoA in protecting GEC from cell death. The MEK1/2 inhibitor, U0126, and mutation of the ERK-dependent phosphorylation site (T678A) prevented complement-induced GEF-H1 activation, indicating a role for the ERK pathway. Further, complement induced GEF-H1 and microtubule accumulation in the perinuclear region. However, both the perinuclear accumulation and the activation of GEF-H1 were independent of microtubules and myosin-mediated contractility, as shown using drugs that interfere with microtubule dynamics and myosin II activity. In summary, we have identified complement-induced ERK-dependent GEF-H1 activation as the upstream mechanism of RhoA stimulation, and this pathway has a protective role against cell death.
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Affiliation(s)
- Flaviana Mouawad
- From the Department of Medicine, McGill University Health Centre, Montreal, Quebec H3A 2B4, Canada and
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19
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Sachs N, Sonnenberg A. Cell-matrix adhesion of podocytes in physiology and disease. Nat Rev Nephrol 2013; 9:200-10. [PMID: 23338211 DOI: 10.1038/nrneph.2012.291] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Cell-matrix adhesion is crucial for maintaining the mechanical integrity of epithelial tissues. Podocytes--a key component of the glomerular filtration barrier--are exposed to permanent transcapillary filtration pressure and must therefore adhere tightly to the underlying glomerular basement membrane (GBM). The major cell-matrix adhesion receptor in podocytes is the integrin α3β1, which connects laminin 521 in the GBM through various adaptor proteins to the intracellular actin cytoskeleton. Other cell-matrix adhesion receptors expressed by podocytes include the integrins α2β1 and αvβ3, α-dystroglycan, syndecan-4 and type XVII collagen. Mutations in genes encoding any of the components critical for podocyte adhesion cause glomerular disease. This Review highlights recent advances in our understanding of the cell biology and genetics of podocyte adhesion with special emphasis on glomerular disease.
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Affiliation(s)
- Norman Sachs
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
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20
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Littman MP, Wiley CA, Raducha MG, Henthorn PS. Glomerulopathy and mutations in NPHS1 and KIRREL2 in soft-coated Wheaten Terrier dogs. Mamm Genome 2013; 24:119-26. [PMID: 23325127 DOI: 10.1007/s00335-012-9445-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 12/10/2012] [Indexed: 02/08/2023]
Abstract
Dogs of the soft-coated wheaten terrier breed (SCWT) are predisposed to adult-onset, genetically complex, protein-losing nephropathy (average onset age = 6.3 ± 2.0 years). A genome-wide association study using 62 dogs revealed a chromosomal region containing three statistically significant SNPs (p(raw) ≤ 4.13 × 10(-8); p(genome) ≤ 0.005) when comparing DNA samples from affected and geriatric (≥14 years) unaffected SCWTs. Sequencing of candidate genes in the region revealed single nucleotide changes in each of two closely linked genes, NPHS1 and KIRREL2, which encode the slit diaphragm proteins nephrin and Neph3/filtrin, respectively. In humans, mutations in nephrin and decreased expression of Neph3 are associated with podocytopathy and protein-losing nephropathy. The base substitutions change a glycine to arginine in the fibronectin type 3 domain of nephrin and a proline to arginine in a conserved proline-rich region in Neph3. These novel mutations are not described in other species, nor were they found in 550 dogs of 105 other breeds, except in 3 dogs, including an affected Airedale terrier, homozygous for both substitutions. Risk for nephropathy is highest in dogs homozygous for the mutations (OR = 9.06; 95 % CI = 4.24-19.35). This is the first molecular characterization of an inherited podocytopathy in dogs and may serve as a model for continued studies of complex genetic and environmental interactions in glomerular disease.
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Affiliation(s)
- Meryl P Littman
- Department of Clinical Studies, University of Pennsylvania School of Veterinary Medicine-Philadelphia, Philadelphia, PA 19104-6010, USA.
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21
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Witzel HR, Jungblut B, Choe CP, Crump JG, Braun T, Dobreva G. The LIM protein Ajuba restricts the second heart field progenitor pool by regulating Isl1 activity. Dev Cell 2012; 23:58-70. [PMID: 22771034 DOI: 10.1016/j.devcel.2012.06.005] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 03/16/2012] [Accepted: 06/04/2012] [Indexed: 11/26/2022]
Abstract
Morphogenesis of the heart requires tight control of cardiac progenitor cell specification, expansion, and differentiation. Retinoic acid (RA) signaling restricts expansion of the second heart field (SHF), serving as an important morphogen in heart development. Here, we identify the LIM domain protein Ajuba as a crucial regulator of the SHF progenitor cell specification and expansion. Ajuba-deficient zebrafish embryos show an increased pool of Isl1(+) cardiac progenitors and, subsequently, dramatically increased numbers of cardiomyocytes at the arterial and venous poles. Furthermore, we show that Ajuba binds Isl1, represses its transcriptional activity, and is also required for autorepression of Isl1 expression in an RA-dependent manner. Lack of Ajuba abrogates the RA-dependent restriction of Isl1(+) cardiac cells. We conclude that Ajuba plays a central role in regulating the SHF during heart development by linking RA signaling to the function of Isl1, a key transcription factor in cardiac progenitor cells.
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Affiliation(s)
- Hagen R Witzel
- Origin of Cardiac Cell Lineages Group, Max Planck Institute for Heart and Lung Research, Parkstrasse 1, Bad Nauheim, Germany
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