title: SLIT2/ROBO2 signaling pathway inhibits nonmuscle myosin IIA activity and destabilizes kidney podocyte adhesion.
abstract: The repulsive guidance cue SLIT2 and its receptor ROBO2 are required for kidney development and podocyte foot process structure, but the SLIT2/ROBO2 signaling mechanism regulating podocyte function is not known. Here we report that a potentially novel signaling pathway consisting of SLIT/ROBO Rho GTPase activating protein 1 (SRGAP1) and nonmuscle myosin IIA (NMIIA) regulates podocyte adhesion downstream of ROBO2. We found that the myosin II regulatory light chain (MRLC), a subunit of NMIIA, interacts directly with SRGAP1 and forms a complex with ROBO2/SRGAP1/NMIIA in the presence of SLIT2. Immunostaining demonstrated that SRGAP1 is a podocyte protein and is colocalized with ROBO2 on the basal surface of podocytes. In addition, SLIT2 stimulation inhibits NMIIA activity, decreases focal adhesion formation, and reduces podocyte attachment to collagen. In vivo studies further showed that podocyte-specific knockout ofRobo2protects mice from hypertension-induced podocyte detachment and albuminuria and also partially rescues the podocyte-loss phenotype inMyh9knockout mice. Thus, we have identified SLIT2/ROBO2/SRGAP1/NMIIA as a potentially novel signaling pathway in kidney podocytes, which may play a role in regulating podocyte adhesion and attachment. Our findings also suggest that SLIT2/ROBO2 signaling might be a therapeutic target for kidney diseases associated with podocyte detachment and loss.
authors.affiliation: Renal Section, Department of Medicine, Boston University Medical Center, Boston, Massachusetts, USA.
authors.forename: Xueping
authors.initials: X
authors.lastname: Fan
authors.affiliation: Centers for Therapeutic Innovation, Pfizer Inc., Boston, Massachusetts, USA.
authors.forename: Hongying
authors.initials: H
authors.lastname: Yang
authors.affiliation: Renal Section, Department of Medicine, Boston University Medical Center, Boston, Massachusetts, USA.
authors.forename: Sudhir
authors.initials: S
authors.lastname: Kumar
authors.affiliation: Centers for Therapeutic Innovation, Pfizer Inc., Boston, Massachusetts, USA.
authors.forename: Kathleen E
authors.initials: KE
authors.lastname: Tumelty
authors.affiliation: Renal Section, Department of Medicine, Boston University Medical Center, Boston, Massachusetts, USA.
authors.forename: Anna
authors.initials: A
authors.lastname: Pisarek-Horowitz
authors.affiliation: Renal Section, Department of Medicine, Boston University Medical Center, Boston, Massachusetts, USA.
authors.forename: Hila Milo
authors.initials: HM
authors.lastname: Rasouly
authors.affiliation: Renal Section, Department of Medicine, Boston University Medical Center, Boston, Massachusetts, USA.
authors.forename: Richa
authors.initials: R
authors.lastname: Sharma
authors.affiliation: Renal Section, Department of Medicine, Boston University Medical Center, Boston, Massachusetts, USA.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Chan
authors.affiliation: Centers for Therapeutic Innovation, Pfizer Inc., Boston, Massachusetts, USA.
authors.forename: Edyta
authors.initials: E
authors.lastname: Tyminski
authors.affiliation: Centers for Therapeutic Innovation, Pfizer Inc., Boston, Massachusetts, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Shamashkin
authors.affiliation: Department of Pathology and Laboratory Medicine, Boston University Medical Center, Boston, Massachusetts, USA.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Belghasem
authors.affiliation: Department of Pathology and Laboratory Medicine, Boston University Medical Center, Boston, Massachusetts, USA.
authors.forename: Joel M
authors.initials: JM
authors.lastname: Henderson
authors.affiliation: Centers for Therapeutic Innovation, Pfizer Inc., Boston, Massachusetts, USA.
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Coyle
authors.affiliation: Renal Section, Department of Medicine, Boston University Medical Center, Boston, Massachusetts, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Salant
authors.affiliation: Centers for Therapeutic Innovation, Pfizer Inc., Boston, Massachusetts, USA.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Berasi
authors.affiliation: Renal Section, Department of Medicine, Boston University Medical Center, Boston, Massachusetts, USA.
authors.forename: Weining
authors.initials: W
authors.lastname: Lu
mesh_terms: D000818:Animals; D002465:Cell Movement; D020690:GTPase-Activating Proteins / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D007668:Kidney; D051379:Mice; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D024507:Nonmuscle Myosin Type IIA / Q000378:metabolism*; D050199:Podocytes / Q000166:cytology*; D011971:Receptors, Immunologic / Q000378:metabolism*; D015398:Signal Transduction; D000098552:Slit Homolog 2 Protein; D000097905:Roundabout Proteins
chemical_list: D020690:GTPase-Activating Proteins; D036341:Intercellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; D024507:Nonmuscle Myosin Type IIA; D011971:Receptors, Immunologic; D000098552:Slit Homolog 2 Protein; C498888:Robo2 protein, mouse; D000097905:Roundabout Proteins