Exercise training decreases store-operated Ca2+entry associated with metabolic syndrome and coronary atherosclerosis.
OBJECTIVE
Stenting attenuates restenosis, but accelerated coronary artery disease (CAD) adjacent to the stent (peri-stent CAD) remains a concern in metabolic syndrome (MetS). Smooth muscle cell proliferation, a major mechanism of CAD, is mediated partly by myoplasmic Ca2+ dysregulation and store-operated Ca2+ entry (SOCE) via canonical transient receptor potential 1 (TRPC1) channels is proposed to play a key role. Exercise is known to prevent Ca2+ dysregulation in CAD. We tested the hypothesis that MetS increases SOCE and peri-stent CAD and exercise attenuates these events.


RESULTS
Groups (n = 9 pigs each) were (i) healthy lean Ossabaw swine fed standard chow, (ii) excess calorie atherogenic diet fed (MetS), and (iii) aerobically exercise trained starting after 50 weeks of development of MetS (XMetS). Bare metal stents were placed after 54 weeks on diets, and CAD and SOCE were assessed 4 weeks later. Coronary cells were dispersed proximal to the stent (peri-stent) and from non-stent segments, and fura-2 fluorescence was used to assess SOCE, which was verified by Ni2+ blockade and insensitivity to nifedipine. XMetS pigs had increased physical work capacity and decreased LDL/HDL (P < 0.05), but no attenuation of robust insulin resistance, glucose intolerance, hypertriglyceridaemia, or hypertension. CAD was greater in peri-stented vs. non-stented artery segments. MetS had the greatest CAD, SOCE, and TRPC1 and STIM1 mRNA and protein expression, which were all attenuated in XMetS.


CONCLUSIONS
This is the first report of the protective effect of exercise on native CAD, peri-stent CAD, SOCE, and molecular expression of TRPC1, STIM1, and Orai1 in MetS.
Edwards
Jason M
JM
Department of Cellular and Integrative Physiology, Indiana University School of Medicine, 635 Barnhill Drive, MS 385, Indianapolis, IN 46202-5120, USA.
Neeb
Zachary P
ZP
Alloosh
Mouhamad A
MA
Long
Xin
X
Bratz
Ian N
IN
Peller
Cassandra R
CR
Byrd
James P
JP
Kumar
Sanjay
S
Obukhov
Alexander G
AG
Sturek
Michael
M
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003324:Coronary Artery Disease / Q000209:etiology / Q000378:metabolism*; D008297:Male; D024821:Metabolic Syndrome / Q000150:complications / Q000378:metabolism*; D010805:Physical Conditioning, Animal; D015607:Stents; D013552:Swine; D050052:TRPC Cation Channels / Q000502:physiology
D050052:TRPC Cation Channels; D002118:Calcium