The Role Of Rab22a In Regulating Hypertension And The Treatment Of Qingda Granules

Objective:The aim of the study is to explore the role of Rab22a on the development of hypertension,aorta function and morphological changes by generating Rab22a knockout?KO?transgenic mice and using the angiotensin-II?Ang II?induced hypertension model as well as identify Rab22a's role in intracellular trafficking of angiotensin II type I receptor?AT1R?and its downstream ERK pathway;to identify the effect of Qingda granules?QDG?on hypertension and its regulatory role of Rab22a/Ca²⁺/ERK pathway.Studying these mechanisms both improves knowledge of hypertension and provides evidence for using QDG to treat hypertension patients.Methods:1.The regulatory role of Rab22a on hypertension:treating Rab22a^+/+and Rab22a^-/-mice with Ang II to constructing hypertension mice model,using non-invasive blood instrument,small animal ultrasound and H&E staining to monitor the blood pressure,the pulse wave velocity?PWV?and morphology changes of abdominal aorta of these hypertensive animals.2.The underline mechanism of Rab22a in regulating hypertension:Using RNA sequencing to detect the differently expressed genes?DEGs?between Rab22a^-/-+Ang II and Rab22a^+/++Ang II groups and potential pathways;Detecting the vascular tone of abdominal aorta isolated in Rab22a^+/+and Rab22a^-/-mice with treatment of Ang II;Isolating vascular smooth muscle cells?VSMCs?from abdominal aorta from Rab22a^+/+and Rab22a^-/-mice,treating with Ang II then using confocal microscope to detect the Ca²⁺concentration,IF to detect the activation of ERK pathway as well as IHC to detect the activation of ERK in abdominal aorta in Ang II-treated Rab22a^+/+and Rab22a^-/-mice;Constructing AT1R overexpressed HEK-293T cells and transfected with si Rab22a to detect the total and membrane protein expression of AT1R after Ang II treatment by WB.3.The regulatory role of QDG on hypertension as well as Rab22a and its related signaling pathway:treating the Ang II-induced hypertensive mice with QDG and using non-invasive blood instrument,small animal ultrasound and H&E staining to monitor the blood pressure,PWV and morphology change of abdominal aorta;using IHC to detect the expression of Rab22a and activation of ERK in abdominal aorta in Ang II-induced hypertensive mice;Isolating the VSMCs from abdominal aorta of rats and treating with Ang II,then using WB and confocal microscope to detect the expression of Rab22a,Ca²⁺release and the activation of ERK in VSMCs.Results:1.The regulatory role of Rab22a on hypertension:lack of Rab22a decreased the blood pressure of Ang II-induced hypertensive mice,decreased the PWV and the thickness of abdominal aorta of hypertensive mice.2.The underline mechanism of Rab22a in regulating hypertension:Vascular muscle contraction and calcium signaling pathway were enriched in DEGs between Rab22a^+/++Ang II and Rab22a^-/-+Ang II groups;lack of Rab22a inhibited the contraction of abdominal aorta of mice with treatment of Ang II;inhibited the Ca²⁺release and the activation of ERK in VSMCs and abdominal aorta of Ang II-induced hypertensive mice;knockdown of Rab22a decreased the membrane expression of AT1R without affecting the total protein expression of AT1R after Ang II treatment.3.The regulatory role of QDG on hypertension as well as Rab22a and its related signaling pathway:QDG treatment decreased the blood pressure of Ang II-induced hypertensive mice,PWV and the thickness of abdominal aorta,decreased the protein expression of Rab22a and inhibited the activation of ERK in abdominal aorta of hypertensive mice;QDG treatment decreased the protein level of Rab22a and inhibited Ca²⁺release and the activation of ERK in VSMCs with Ang II treatment.Conclusion:1.Rab22a mediates the development of hypertension by decreasing the protein expression of AT1R on cell membrane to inhibit the Ca²⁺release and activation of ERK.2.QDG treatment decreases blood pressure and alleviates the aorta function and morphology changes by downregulating protein expression of Rab22a and regulating Rab22a/Ca²⁺/ERK pathway.