|Liu D (2018) Enhanced Trpc3-mediated mitochondrial respiratory dysfunction by inhibition of mitochondria-hexokinase in monocytes from hypertension rats. Atherosclerosis.|
Liu D (2018)
Inhibition of transient receptor potential channel, canonical type 3 (TRPC3) attenuates monocytes and vasculature calcium influx in spontaneously hypertensive rats (SHRs). However, it remains elusive whether mitochondrial TRPC3 participates in increasing mitochondrial calcium homeostasis and ROS production in monocytes from hypertension.
3-months age SHR and normotensive Wistar-Kyoto rats (WKYs) were treated telmisartan at 5 mg/kg/day orally or without telmisartan as control for 3 months. Mitochondrial membrane potential changes (DJm) were indicated by a shift from red (JC-1 aggregates) to green (JC-1 monomers) fluorescence. Mitochondrial ROS productionwas quantified by MitoSOX. Mitochondrial respiratory function was analyzed by respirometer (Oxygraph-2k; Innsbruck, Austria). Proteins were identified by immunoblotting. The cytosolic Ca2+ concentrations, [Ca2+]c and mitochondrial [2+]mito, were measured using Fura-2 AM and Rhod-2 AM (ThermoFisher).
We demonstrated that increased mitochondrial TRPC3 expression, which facilitates mitochondrial calcium uptake and ROS produce in the monocytes from SHRs compared to WKYs. Monocytes mitochondrial respiratory function were significantly increased in SHRs. Inhibition of TRPC3 by its specific inhibitor, Pyr3, or telmisartan significantly increased the monocytes mitochondrial membrane potential changes (DJm) and decreased ROS production. Telmisartan or TRPC3 knockdown significantly attenuated, and TRPC3 over-expression significantly elevated the H2O2-induced cytosolic [2+]c and mitochondrial [2+]mito uptake, ROS production in THP-1 cells. In vivo, chronic administration of telmisartan inhibited mitochondrial respiratory function while decreased TRPC3 in monocytes from SHR. Telmisartan intervention decreased plasma levels of inflammation-related factors in SHRs. Most important is that we found that mitochondrial respiratory function were significantly increased in monocytes from SHRs compared to WKYs. Long-term of telmisartan decreased monocytes mitochondrial respiratory function parameters Routine, CI OXPHOS, CI+II OXPHOS and CIV ETS in SHRs while compared to WKYs. Proteins expression of hexokinase 1 (HXK1) and HXK2, a primary initiator of glycolysis, were significantly reduced in monocytes from SHRs compared to WKYs. Long-term of telmisartan increased proteins expression of HXK1 and HXK2 in monocytes from SHRs.
Enhanced mitochondrial TRPC3-mediated calcium handling involved in mitochondrial respiratory dysfunction in monocytes from SHRs. Inhibition of TRPC3 decreasing mitochondrial calcium uptake and ROS production through a hexokinases-dependent pathway in monocytes from hypertension rats.
Labels: MiParea: Respiration Pathology: Cardiovascular
Preparation: Intact cells
Coupling state: ROUTINE, OXPHOS, ET Pathway: N, CIV, NS HRR: Oxygraph-2k