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Artelt N, Ludwig TA, Rogge H, Kavvadas P, Siegerist F, Blumenthal A, van den Brandt J, Otey CA, Bang ML, Amann K, Chadjichristos CE, Chatziantoniou C, Endlich K, Endlich N. The Role of Palladin in Podocytes. J Am Soc Nephrol 2018; 29:1662-1678. [PMID: 29720549 DOI: 10.1681/asn.2017091039] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 03/28/2018] [Indexed: 11/03/2022] Open
Abstract
Background Podocyte loss and effacement of interdigitating podocyte foot processes are the major cause of a leaky filtration barrier and ESRD. Because the complex three-dimensional morphology of podocytes depends on the actin cytoskeleton, we studied the role in podocytes of the actin bundling protein palladin, which is highly expressed therein.Methods We knocked down palladin in cultured podocytes by siRNA transfection or in zebrafish embryos by morpholino injection and studied the effects by immunofluorescence and live imaging. We also investigated kidneys of mice with podocyte-specific knockout of palladin (PodoPalld-/- mice) by immunofluorescence and ultrastructural analysis and kidney biopsy specimens from patients by immunostaining for palladin.Results Compared with control-treated podocytes, palladin-knockdown podocytes had reduced actin filament staining, smaller focal adhesions, and downregulation of the podocyte-specific proteins synaptopodin and α-actinin-4. Furthermore, palladin-knockdown podocytes were more susceptible to disruption of the actin cytoskeleton with cytochalasin D, latrunculin A, or jasplakinolide and showed altered migration dynamics. In zebrafish embryos, palladin knockdown compromised the morphology and dynamics of epithelial cells at an early developmental stage. Compared with PodoPalld+/+ controls, PodoPalld-/- mice developed glomeruli with a disturbed morphology, an enlarged subpodocyte space, mild effacement, and significantly reduced expression of nephrin and vinculin. Furthermore, nephrotoxic serum injection led to significantly higher levels of proteinuria in PodoPalld-/- mice than in controls. Kidney biopsy specimens from patients with diabetic nephropathy and FSGS showed downregulation of palladin in podocytes as well.Conclusions Palladin has an important role in podocyte function in vitro and in vivo.
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Affiliation(s)
| | | | | | - Panagiotis Kavvadas
- National Institute for Health and Medical Research (INSERM), Unité Mixte de Recherche (UMR)-S1155, Tenon Hospital, Sorbonne Universités, Paris, France
| | | | | | - Jens van den Brandt
- Central Core and Research Facility of Laboratory Animals (ZSFV), University Medicine Greifswald, Greifswald, Germany
| | - Carol A Otey
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill (UNC), Chapel Hill, North Carolina
| | - Marie-Louise Bang
- Institute of Genetic and Biomedical Research, UOS Milan, National Research Council, Milan, Italy.,Humanitas Clinical and Research Center, Rozzano, Milan, Italy; and
| | - Kerstin Amann
- Department of Nephropathology, University Medicine Erlangen, Erlangen, Germany
| | - Christos E Chadjichristos
- National Institute for Health and Medical Research (INSERM), Unité Mixte de Recherche (UMR)-S1155, Tenon Hospital, Sorbonne Universités, Paris, France
| | - Christos Chatziantoniou
- National Institute for Health and Medical Research (INSERM), Unité Mixte de Recherche (UMR)-S1155, Tenon Hospital, Sorbonne Universités, Paris, France
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McLane JS, Ligon LA. Palladin mediates stiffness-induced fibroblast activation in the tumor microenvironment. Biophys J 2016. [PMID: 26200861 DOI: 10.1016/j.bpj.2015.06.033] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Mechanical properties of the tumor microenvironment have emerged as key factors in tumor progression. It has been proposed that increased tissue stiffness can transform stromal fibroblasts into carcinoma-associated fibroblasts. However, it is unclear whether the three to five times increase in stiffness seen in tumor-adjacent stroma is sufficient for fibroblast activation. In this study we developed a three-dimensional (3D) hydrogel model with precisely tunable stiffness and show that a physiologically relevant increase in stiffness is sufficient to lead to fibroblast activation. We found that soluble factors including CC-motif chemokine ligand (CCL) chemokines and fibronectin are necessary for this activation, and the combination of C-C chemokine receptor type 4 (CCR4) chemokine receptors and β1 and β3 integrins are necessary to transduce these chemomechanical signals. We then show that these chemomechanical signals lead to the gene expression changes associated with fibroblast activation via a network of intracellular signaling pathways that include focal adhesion kinase (FAK) and phosphoinositide 3-kinase (PI3K). Finally, we identify the actin-associated protein palladin as a key node in these signaling pathways that result in fibroblast activation.
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Affiliation(s)
- Joshua S McLane
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York; Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York
| | - Lee A Ligon
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, New York; Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy, New York.
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Cannon AR, Owen MK, Guerrero MS, Kerber ML, Goicoechea SM, Hemstreet KC, Klazynski B, Hollyfield J, Chang EH, Hwang RF, Otey CA, Kim HJ. Palladin expression is a conserved characteristic of the desmoplastic tumor microenvironment and contributes to altered gene expression. Cytoskeleton (Hoboken) 2015; 72:402-11. [PMID: 26333695 DOI: 10.1002/cm.21239] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 07/29/2015] [Accepted: 08/07/2015] [Indexed: 01/05/2023]
Abstract
The stroma surrounding solid tumors contributes in complex ways to tumor progression. Cancer-associated fibroblasts (CAFs) are the predominant cell type in the tumor stroma. Previous studies have shown that the actin-binding protein palladin is highly expressed in the stroma of pancreas tumors, but the interpretation of these results is complicated by the fact that palladin exists as multiple isoforms. In the current study, the expression and localization of palladin isoform 4 was examined in normal specimens and adenocarcinomas of human pancreas, lung, colon, and stomach samples. Immunohistochemistry with isoform-selective antibodies revealed that expression of palladin isoform 4 was higher in adenocarcinomas versus normal tissues, and highest in CAFs. Immunohistochemistry staining revealed that palladin was present in both the cytoplasm and the nucleus of CAFs, and this was confirmed using immunofluorescence staining and subcellular fractionation of a pancreatic CAF cell line. To investigate the functional significance of nuclear palladin, RNA Seq analysis of palladin knockdown CAFs versus control CAFs was performed, and the results showed that palladin regulates the expression of genes involved in the biosynthesis and assembly of collagen, and organization of the extracellular matrix. These results suggested that palladin isoform 4 may play a conserved role in establishing the phenotype of CAFs in multiple tumor types.
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Affiliation(s)
- Austin R Cannon
- Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Meredith K Owen
- Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Michael S Guerrero
- Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Michael L Kerber
- Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | | | - Kathryn C Hemstreet
- Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Brian Klazynski
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Johnathan Hollyfield
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Emily H Chang
- Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Kidney Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Rosa F Hwang
- Department of Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Carol A Otey
- Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Hong Jin Kim
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.,Department of Surgery, UNC School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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Tan K, An L, Wang SM, Wang XD, Zhang ZN, Miao K, Sui LL, He SZ, Nie JZ, Wu ZH, Tian JH. Actin Disorganization Plays a Vital Role in Impaired Embryonic Development of In Vitro-Produced Mouse Preimplantation Embryos. PLoS One 2015; 10:e0130382. [PMID: 26076347 PMCID: PMC4468147 DOI: 10.1371/journal.pone.0130382] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 05/19/2015] [Indexed: 02/04/2023] Open
Abstract
Assisted reproductive technology (ART) is being increasingly applied to overcome infertility. However, the in vitro production process, the main procedure of ART, can lead to aberrant embryonic development and health-related problems in offspring. Understanding the mechanisms underlying the ART-induced side effects is important to improve the ART process. In this study, we carried out comparative transcriptome profiling between in vivo- (IVO) and in vitro- produced (IVP) mouse blastocysts. Our results suggested that aberrant actin organization might be a major factor contributing to the impaired development of IVP embryos. To test this, we examined the effect of actin disorganization on the development of IVP preimplantation embryos. Specific disruption of actin organization by cytochalasin B (CB) indicated that well-organized actin is essential for in vitro embryonic development. Supplementing the culture medium with 10–9 M melatonin, a cytoskeletal modulator in adult somatic cells, significantly reversed the disrupted expression patterns of genes related to actin organization, including Arhgef2, Bcl2, Coro2b, Flnc, and Palld. Immunofluorescence analysis showed that melatonin treatment of IVP embryos significantly improved the distribution and organization of actin filaments (F-actin) from the 8-cell stage onwards. More importantly, we found that melatonin alleviated the CB-mediated aberrant F-actin distribution and organization and rescued CB-induced impaired embryonic development. This is the first study to indicate that actin disorganization is implicated in impaired development of IVP embryos during the preimplantation stage. We also demonstrated that improving actin organization is a promising strategy to optimize existing IVP systems.
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Affiliation(s)
- Kun Tan
- Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, P. R. China
| | - Lei An
- Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, P. R. China
| | - Shu-Min Wang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, P. R. China
| | - Xiao-Dong Wang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, P. R. China
| | - Zhen-Ni Zhang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, P. R. China
| | - Kai Miao
- Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, P. R. China
| | - Lin-Lin Sui
- Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, P. R. China
| | - Shu-Zhi He
- Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, P. R. China
| | - Jing-Zhou Nie
- Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, P. R. China
| | - Zhong-Hong Wu
- Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, P. R. China
| | - Jian-Hui Tian
- Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, P. R. China
- * E-mail:
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Abstract
PURPOSE OF REVIEW The present review examines the role of actin binding proteins (ABPs) on blood-testis barrier (BTB), an androgen-dependent ultrastructure in the testis, in particular their involvement on BTB remodeling during spermatogenesis. RECENT FINDINGS The BTB divides the seminiferous epithelium into the basal and the adluminal compartments. The BTB is constituted by coexisting actin-based tight junction, basal ectoplasmic specialization, and gap junction, and also intermediate filament-based desmosome between Sertoli cells near the basement membrane. Junctions at the BTB undergo continuous remodeling to facilitate the transport of preleptotene spermatocytes residing in the basal compartment across the immunological barrier during spermatogenesis. Thus, meiosis I/II and postmeiotic spermatid development take place in the adluminal compartment behind the BTB. BTB remodeling also regulates exchanges of biomolecules between the two compartments. As tight junction, basal ectoplasmic specialization, and gap junction use F-actin for attachment, actin microfilaments rapidly convert between their bundled and unbundled/branched configuration to confer BTB plasticity. The events of actin reorganization are regulated by two major classes of ABPs that convert actin microfilaments between their bundled and branched/unbundled configuration. SUMMARY We provide a model on how ABPs regulate BTB remodeling, shedding new light on unexplained male infertility, such as environmental toxicant-induced reproductive dysfunction since the testis, in particular the BTB, is sensitive to environmental toxicants, such as cadmium, bisphenol A, phthalates, and PFOS (perfluorooctanesulfonic acid or perfluorooctane sulfonate).
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Affiliation(s)
- Nan Li
- The Mary M. Wohlford Laboratory for Male Contraceptive Research, Center for Biomedical Research, Population Council, New York, New York, USA
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