Cabin1 localizes in glomerular podocyte and undergoes nuclear translocation during podocyte injury.
BACKGROUND
Podocyte injury is related to increasing proteinuria and contributes to the progression of kidney disease. Calcineurin binding protein 1 (Cabin1) is a repressor of myocyte enhancer factor 2 (MEF2) and calcineurin-mediated transcription in the immune system. Moreover, Cabin1 interacts with p53 and negatively regulates p53 in tumor cells. However, its function in kidney is unknown.


OBJECTIVE
To explore the exact localization of Cabin1 in glomeruli, as well as the relationship between Cabin1 and podocyte injury.


METHODS
Sprague-Dawley rats were sacrificed to observe the localization and protein expression of Cabin1 in the kidney. Cabin1 localization and protein expression were detected by immunofluorescence staining and western blot, respectively. Mouse podocytes were cultivated at 33 °C to propagate, then cells were transferred to an incubator at 37 °C to allow differentiation. Differentiated podocytes were stimulated by angiotensin II (AngII) or AngII plus tacrolimus. Cells were harvested to detect the localization and protein expression of Cabin1. Cytoplasmic and nuclear protein were separated by protein extraction kit.


RESULTS
Cabin1 mainly localized in the nuclei of glomerular innate cells, it colocalized with WT-1 in podocytes nuclei. Western bolt showed Cabin1 protein remarkably expressed in renal cortex. AngII-induced Cabin1 nuclear protein significantly increased, accompanied by cytoskeleton disruption in cultured mouse podocytes.


CONCLUSIONS
Cabin1 localizes in glomerular podocytes. AngII induces nuclear translocation of Cabin1 in cultured podocytes.
a Department of Nephrology , The Second Affiliated Hospital, GuangZhou Medical University , Guangzhou , China and.
Yueqiang
Y
Wen
a Department of Nephrology , The Second Affiliated Hospital, GuangZhou Medical University , Guangzhou , China and.
Zebin
Z
Wang
b Department of General Medicine , The Third Affiliated Hospital, Sun Yat-sen University , Guangzhou , China.
Lingling
L
Liu
a Department of Nephrology , The Second Affiliated Hospital, GuangZhou Medical University , Guangzhou , China and.
Yajie
Y
Zhang
a Department of Nephrology , The Second Affiliated Hospital, GuangZhou Medical University , Guangzhou , China and.
Peilan
P
Zhou
a Department of Nephrology , The Second Affiliated Hospital, GuangZhou Medical University , Guangzhou , China and.
Jianbo
J
Liang
D000804:Angiotensin II / Q000378:metabolism*; D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism*; D019703:Calcineurin / Q000378:metabolism*; D002478:Cells, Cultured; D007678:Kidney Glomerulus / Q000473:pathology*; D008297:Male; D051379:Mice; D050199:Podocytes / Q000473:pathology*; D011507:Proteinuria / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012307:Risk Factors
D051017:Apoptosis Regulatory Proteins; C113573:Cabin1 protein, rat; D000804:Angiotensin II; D019703:Calcineurin
Angiotensin II; Cabin1; calcineurin; glomeruli; p53; podocyte