Effect of GRK4 on renal gastrin receptor regulation in hypertension
Effect of GRK4 on renal gastrin receptor regulation in hypertension
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DOI：
10.1080/10641963.2023.2245580
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发表时间：
2023-12-31
影响因子：
12.3
通讯作者：
Xu，Xiang
中科院分区：
文献类型：
--
作者：
Xia，Xuewei;Zeng，Yongchun;Xu，Xiang
目的探讨GRK4是否调节肾CCKBR的磷酸化和功能。方法采用GRK4A142V转基因小鼠作为GRK4活性增强的动物模型，用siRNA沉默GRK4基因，观察GRK4对CCKBR磷酸化和功能的调节。最后，通过激光共聚焦显微镜和免疫共沉淀法观察GRK4和CCKBR在RPT细胞中的共定位和共连接，以探讨GRK4调节CCKBR的机制。结果灌胃胃泌素显著增加GRK4WT小鼠的尿流量和钠排泄率(P<； .05)。GRK4siRNA对WKY RPT和SHR RPT细胞CCKBR蛋白表达无明显影响，但显著降低WKY和SHR RPT细胞CCKBR的磷酸化水平(P<； .05)。胃泌素对WKY RPT细胞Na+-K+-ATPase活性的抑制作用随着GRK4表达的降低而进一步增强(P<； .05)，而GRK4siRNA则恢复了胃泌素对SHR RPT细胞Na+-K+-ATPase活性的抑制作用。激光共聚焦和免疫共沉淀结果显示，GRK4和CCKBR共定位于培养的RPT细胞胞浆中。结论GRK4通过调节肾CCKBR的磷酸化，导致CCKBR功能受损和水钠滞留，参与高血压的发生发展。GRK4基因敲除后CCKBR功能恢复。GRK4和CCKBR的协同作用增强可能是GRK4和CCKBR过度磷酸化参与高血压发病机制的重要原因。
ObjectiveTo investigate whether GRK4 regulates the phosphorylation and function of renal CCKBR.MethodsGRK4 A142V transgenic mice were used as an animal model of enhanced GRK4 activity, and siRNA was used to silence the GRK4 gene to investigate the regulatory effect of GRK4 on CCKBR phosphorylation and function. Finally, the co-localization and co-connection of GRK4 and CCKBR in RPT cells were observed by laser confocal microscopy and immunoprecipitation to explore the mechanism of GRK4 regulating CCKBR.ResultsGastrin infusion significantly increased urinary flow and sodium excretion rates in GRK4 WT mice (P< .05). GRK4 siRNA did not affect CCKBR protein expression in WKY RPT cells and SHR RPT cells, but remarkably reduced CCKBR phosphorylation in WKY and SHR RPT cells (P< .05). The inhibitory effect of gastrin on Na+-K+-ATPase activity in WKY RPT cells was further enhanced by the reduction of GRK4 expression (P< .05), while GRK4 siRNA restored the inhibitory effect of gastrin on Na+-K+-ATPase activity in SHR RPT cells. Laser confocal and Co-immunoprecipitation results showed that GRK4 and CCKBR co-localized in cultured RPT cells’ cytoplasm.ConclusionGRK4 participates in the development of hypertension by regulating the phosphorylation of renal CCKBR leading to impaired CCKBR function and water and sodium retention. Knockdown of GRK4 restored the function of CCKBR. The enhanced co-connection between GRK4 and CCKBR may be an important reason for the hyperphosphorylation of GRK4 and CCKBR involved in the pathogenesis of hypertension.