title: Non-muscle myosin-IIA is critical for podocyte f-actin organization, contractility, and attenuation of cell motility.
abstract: Several glomerular pathologies resulting from podocyte injury are linked to genetic variation involving the MYH9 gene, which encodes the heavy chain of non-muscle myosin-IIA (NM-IIA). However, the functional role of NM-IIA has not been studied extensively in podocytes. We hypothesized that NM-IIA is critical for maintenance of podocyte structure and mechanical function. To test this hypothesis, we studied murine podocytes in vitro subjected to blebbistatin inhibition of NM-II activity, or RNA interference-mediated, isoform-specific ablation of Myh9 gene and protein (NM-IIA) or its paralog Myh10 gene and protein (NM-IIB). Using quantitative immunofluorescence microscopy, traction force microscopy, and attachment and "wound healing" assays, we found that NM-IIA ablation altered podocyte actin cytoskeletal structure and focal adhesion distribution, decreased cell attachment and contractility, and increased cell motility. Blebbistatin treatment had similar effects. NM-IIB ablation produced cells that exhibited poor attachment, but cytoskeletal structural organization, contractility and motility were maintained. These findings indicate that NM-IIA is essential for maintenance of podocyte cytoskeletal structure and mechanical function in vitro, and NM-IIB does not replace it in this role when NM-IIA expression is altered. We conclude that critical podocyte functions may be affected by MYH9 mutations or disease-associated haplotypes. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Pathology and Laboratory Medicine, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts.
authors.forename: Philip A
authors.initials: PA
authors.lastname: Bondzie
authors.affiliation: Department of Pathology and Laboratory Medicine, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts.
authors.forename: Hui A
authors.initials: HA
authors.lastname: Chen
authors.affiliation: Department of Pathology and Laboratory Medicine, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts.
authors.forename: Mei Zhen
authors.initials: MZ
authors.lastname: Cao
authors.affiliation: Department of Pathology and Laboratory Medicine, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Tomolonis
authors.affiliation: Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
authors.forename: Fangfang
authors.initials: F
authors.lastname: He
authors.affiliation: Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts.
authors.forename: Martin R
authors.initials: MR
authors.lastname: Pollak
authors.affiliation: Department of Pathology and Laboratory Medicine, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts.
authors.forename: Joel M
authors.initials: JM
authors.lastname: Henderson
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D000199:Actins / Q000378:metabolism*; D002465:Cell Movement; D006801:Humans; D009119:Muscle Contraction; D024507:Nonmuscle Myosin Type IIA / Q000378:metabolism*; D050199:Podocytes / Q000378:metabolism* / Q000473:pathology
chemical_list: D000199:Actins; D024507:Nonmuscle Myosin Type IIA
keywords: adhesion; contractility; cytoskeleton; motility; myosin; podocyte