TY - JOUR
T1 - Rac1 promotes kidney collecting duct integrity by limiting actomyosin activity
AU - Bock, Fabian
AU - Elias, Bertha C.
AU - Dong, Xinyu
AU - Parekh, Diptiben V.
AU - Mernaugh, Glenda
AU - Viquez, Olga M.
AU - Hassan, Anjana
AU - Amara, Venkateswara Rao
AU - Liu, Jiageng
AU - Brown, Kyle L.
AU - Terker, Andrew S.
AU - Chiusa, Manuel
AU - Gewin, Leslie S.
AU - Fogo, Agnes B.
AU - Brakebusch, Cord H.
AU - Pozzi, Ambra
AU - Zent, Roy
N1 - Funding Information:
This work was supported in part by U.S. Department of Veterans Affairs Merit Reviews 1I01BX002196 (R. Zent), 1I01BX002025 (A. Pozzi), and 1I01BX003425 (L.S. Gewin); and National Institutes of Health grants R01-DK069921 and R01-DK127589 (R. Zent), R01-DK119212 (A. Pozzi), R01-DK-108968-01 (L. Gewin), R01-DK56942 (A.B. Fogo), P30-DK114809 (R. Zent, A. Pozzi, L.S. Gewin, and A.B. Fogo), and 2T32DK007569-32 (F. Bock and A.S. Terker). F. Bock is the recipient of an American Society of Nephrology Ben J. Lipps Research Fellowship. A.S. Terker is the recipient of an American Heart Association postdoctoral fellowship. A. Pozzi is the recipient of a U.S. Department of Veterans Affairs Senior Research Career Scientist award. Confocal imaging, electron microscopy, and image analysis were performed in part using the Vanderbilt Cell Imaging Shared Resource (supported by National Institutes of Health grants CA68485, DK20593, DK58404, DK59637, and EY08126). The Zeiss LSM880 Airy Scan is supported by National Institutes of Health grant S10-OD021630. Flow cytometry experiments were performed in the VUMC Flow Cytometry Shared Resource. The VUMC Flow Cytometry Shared Resource is supported by the Vanderbilt-Ingram Cancer Center (P30 CA68485) and the Vanderbilt Digestive Disease Research Center (DK058404). Histology was performed with the support of the Translational Pathology Shared Resource (National Cancer Institute/National Institutes of Health Cancer Center Support Grant 5P30 CA68485-19). The authors declare no competing financial interests.
Publisher Copyright:
© 2021 Bock et al.
PY - 2021/11/1
Y1 - 2021/11/1
N2 - A polarized collecting duct (CD), formed from the branching ureteric bud (UB), is a prerequisite for an intact kidney. The small Rho GTPase Rac1 is critical for actin cytoskeletal regulation. We investigated the role of Rac1 in the kidney collecting system by selectively deleting it in mice at the initiation of UB development. The mice exhibited only a mild developmental phenotype; however, with aging, the CD developed a disruption of epithelial integrity and function. Despite intact integrin signaling, Rac1-null CD cells had profound adhesion and polarity abnormalities that were independent of the major downstream Rac1 effector, Pak1. These cells did however have a defect in the WAVE2–Arp2/3 actin nucleation and polymerization apparatus, resulting in actomyosin hyperactivity. The epithelial defects were reversible with direct myosin II inhibition. Furthermore, Rac1 controlled lateral membrane height and overall epithelial morphology by maintaining lateral F-actin and restricting actomyosin. Thus, Rac1 promotes CD epithelial integrity and morphology by restricting actomyosin via Arp2/3-dependent cytoskeletal branching.
AB - A polarized collecting duct (CD), formed from the branching ureteric bud (UB), is a prerequisite for an intact kidney. The small Rho GTPase Rac1 is critical for actin cytoskeletal regulation. We investigated the role of Rac1 in the kidney collecting system by selectively deleting it in mice at the initiation of UB development. The mice exhibited only a mild developmental phenotype; however, with aging, the CD developed a disruption of epithelial integrity and function. Despite intact integrin signaling, Rac1-null CD cells had profound adhesion and polarity abnormalities that were independent of the major downstream Rac1 effector, Pak1. These cells did however have a defect in the WAVE2–Arp2/3 actin nucleation and polymerization apparatus, resulting in actomyosin hyperactivity. The epithelial defects were reversible with direct myosin II inhibition. Furthermore, Rac1 controlled lateral membrane height and overall epithelial morphology by maintaining lateral F-actin and restricting actomyosin. Thus, Rac1 promotes CD epithelial integrity and morphology by restricting actomyosin via Arp2/3-dependent cytoskeletal branching.
UR - http://www.scopus.com/inward/record.url?scp=85118513706&partnerID=8YFLogxK
U2 - 10.1083/jcb.202103080
DO - 10.1083/jcb.202103080
M3 - Article
C2 - 34647970
AN - SCOPUS:85118513706
VL - 220
JO - Journal of Cell Biology
JF - Journal of Cell Biology
SN - 0021-9525
IS - 11
M1 - e202103080
ER -