Browsing by Subject "Angiotensin II / metabolism"
Now showing 1 - 2 of 2
- Results Per Page
- Sort Options
Item Increased glomerular filtration rate and impaired contractile function of mesangial cells in TRPC6 knockout mice(Springer Nature, 2017-06-23) Li, Weizu; Ding, Yanfeng; Smedley, Crystal; Wang, Yanxia; Chaudhari, Sarika; Birnbaumer, Lutz; Ma, RongThe present study was conducted to determine if TRPC6 regulates glomerular filtration rate (GFR) and the contractile function of glomerular mesangial cells (MCs). GFR was assessed in conscious TRPC6 wild type and knockout mice, and in anesthetized rats with and without in vivo knockdown of TRPC6 in kidneys. We found that GFR was significantly greater, and serum creatinine level was significantly lower in TRPC6 deficient mice. Consistently, local knockdown of TRPC6 in kidney using TRPC6 specific shRNA construct significantly attenuated Ang II-induced GFR decline in rats. Furthermore, Ang II-stimulated contraction and Ca(2+) entry were significantly suppressed in primary MCs isolated from TRPC6 deficient mice, and the Ca(2+) response could be rescued by re-introducing TRPC6. Moreover, inhibition of reverse mode of Na(+)-Ca(2+) exchange by KB-R7943 significantly reduced Ca(2+) entry response in TRPC6-expressing, but not in TRPC6-knocked down MCs. Ca(2+) entry response was also significantly attenuated in Na(+) free solution. Single knockdown of TRPC6 and TRPC1 resulted in a comparable suppression on Ca(2+) entry with double knockdown of both. These results suggest that TRPC6 may regulate GFR by modulating MC contractile function through multiple Ca(2+) signaling pathways.Item Sniffer cells for the detection of neural Angiotensin II in vitro(Springer Nature, 2019-06-19) Farmer, George E.; Amune, Anna; Bachelor, Martha E.; Duong, Phong; Yuan, Joseph P.; Cunningham, J. ThomasNeuropeptide release in the brain has traditionally been difficult to observe. Existing methods lack temporal and spatial resolution that is consistent with the function and size of neurons. We use cultured "sniffer cells" to improve the temporal and spatial resolution of observing neuropeptide release. Sniffer cells were created by stably transfecting Chinese Hamster Ovary (CHO) cells with plasmids encoding the rat angiotensin type 1a receptor and a genetically encoded Ca2+ sensor. Isolated, cultured sniffer cells showed dose-dependent increases in fluorescence in response to exogenously applied angiotensin II and III, but not other common neurotransmitters. Sniffer cells placed on the median preoptic nucleus (a presumptive site of angiotensin release) displayed spontaneous activity and evoked responses to either electrical or optogenetic stimulation of the subfornical organ. Stable sniffer cell lines could be a viable method for detecting neuropeptide release in vitro, while still being able to distinguish differences in neuropeptide concentration.