scholarly journals Role of an aprotinin-sensitive protease in the activation of Ca2+-ATPase by superoxide radical (O2-.) in microsomes of pulmonary vascular smooth muscle

1996 ◽  
Vol 317 (3) ◽  
pp. 885-890 ◽  
Author(s):  
Tapati CHAKRABORTI ◽  
Salil K. GHOSH ◽  
John R. MICHAEL ◽  
Sajal CHAKRABORTI
Keyword(s):  
Superoxide Dismutase ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Atpase Activity ◽  
Molecular Mass ◽  
Protease Activity ◽  
Superoxide Radical ◽  
Polyclonal Antiserum ◽  
Generating System

We have investigated the role of an aprotinin-sensitive protease in regulating Ca2+-ATPase activity and Ca2+ uptake (ATP-dependent and Na+-dependent) in microsomes of bovine pulmonary vascular smooth muscle during treatment with the O2-•-generating system hypoxanthine plus xanthine oxidase. Treatment of the smooth muscle microsomes with the O2-•-generating system produced a protease in a gelatin-containing zymogram with an apparent molecular mass of 16 kDa. This 16 kDa proteolytic protein was found to be inhibited by superoxide dismutase (SOD) and aprotinin but not by PMSF. Using polyclonal antiserum to aprotinin, we found that it is an ambient antiprotease of the smooth muscle microsomes. Treatment of the microsomes with the O2-•-generating system stimulated protease activity tested with a synthetic substrate N-benzoyl-dl-arginine p-nitroanilide and also enhanced Ca2+-ATPase activity. It also stimulated ATP-dependent Ca2+ uptake. In contrast, Na+-dependent Ca2+ uptake was found to be inhibited by the O2-•-generating system. Pretreatment of the microsomes with SOD and aprotinin preserved the increase in protease activity, Ca2+-ATPase activity and ATP-dependent Ca2+ uptake. In addition, O2-•-caused inhibition of the Na+-dependent Ca2+ uptake which was reversed by SOD and aprotinin. Pretreatment with PMSF did not cause any discernible alteration in the protease activity, Ca2+-ATPase activity, ATP-dependent Ca2+ uptake and Na+-dependent Ca2+ uptake in the microsomes caused by the O2-•-generating system. These results suggest that an aprotinin-sensitive protease plays a pivotal role in regulating Ca2+-ATPase and Ca2+-uptake activities in microsomes of pulmonary vascular smooth muscle under oxidant O2-•-triggered conditions.

Hyperglycemia increases endothelial superoxide that impairs smooth muscle cell Na+-K+-ATPase activity

2002 ◽  
Vol 282 (3) ◽  
pp. C560-C566 ◽  
Author(s):  
Sandeep Gupta ◽  
Eugene Chough ◽  
Jennifer Daley ◽  
Peter Oates ◽  
Keith Tornheim ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Superoxide Dismutase ◽  
Smooth Muscle ◽  
Steady State ◽  
Atpase Activity ◽  
Rabbit Aorta ◽  
Enhanced Chemiluminescence ◽  
Arterial Tissue ◽  
Reciprocal Change

Nitric oxide (NO) plays an important role in the control of numerous vascular functions including basal Na+-K+-ATPase activity in arterial tissue. Hyperglycemia inhibits Na+-K+-ATPase activity in rabbit aorta, in part, through diminished bioactivity of NO. The precise mechanism(s) for such observations, however, are not yet clear. The purpose of this study was to examine the role of superoxide in modulating NO-mediated control of Na+-K+-ATPase in response to hyperglycemia. Rabbit aorta incubated with hyperglycemic glucose concentrations (44 mM) demonstrated a 50% reduction in Na+-K+-ATPase activity that was abrogated by superoxide dismutase. Hyperglycemia also produced a 50% increase in steady-state vascular superoxide measured by lucigenin-enhanced chemiluminescence that was closely associated with reduced Na+-K+-ATPase activity. Specifically, the hyperglycemia-induced increase in vascular superoxide was endothelium dependent, inhibited by l-arginine, and stimulated by N ω-nitro-l-arginine. Aldose reductase inhibition with zopolrestat also inhibited the hyperglycemia-induced increase in vascular superoxide. In each manipulation of vascular superoxide, a reciprocal change in Na+-K+-ATPase activity was observed. Finally, a commercially available preparation of Na+-K+-ATPase was inhibited by pyrogallol, a superoxide generator. These data suggest that hyperglycemia induces an increase in endothelial superoxide that inhibits the stimulatory effect of NO on vascular Na+-K+-ATPase activity.

scholarly journals The role of mitochondrial bioenergetics and reactive oxygen species in coronary collateral growth

2013 ◽  
Vol 305 (9) ◽  
pp. H1275-H1280 ◽  
Author(s):  
Yuh Fen Pung ◽  
Wai Johnn Sam ◽  
James P. Hardwick ◽  
Liya Yin ◽  
Vahagn Ohanyan ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Protein Synthesis ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Energy Production ◽  
Phenotypic Switching ◽  
Oxygen Species ◽  
Coronary Collateral ◽  
Collateral Growth

Coronary collateral growth is a process involving coordination between growth factors expressed in response to ischemia and mechanical forces. Underlying this response is proliferation of vascular smooth muscle and endothelial cells, resulting in an enlargement in the caliber of arterial-arterial anastomoses, i.e., a collateral vessel, sometimes as much as an order of magnitude. An integral element of this cell proliferation is the process known as phenotypic switching in which cells of a particular phenotype, e.g., contractile vascular smooth muscle, must change their phenotype to proliferate. Phenotypic switching requires that protein synthesis occurs and different kinase signaling pathways become activated, necessitating energy to make the switch. Moreover, kinases, using ATP to phosphorylate their targets, have an energy requirement themselves. Mitochondria play a key role in the energy production that enables phenotypic switching, but under conditions where mitochondrial energy production is constrained, e.g., mitochondrial oxidative stress, this switch is impaired. In addition, we discuss the potential importance of uncoupling proteins as modulators of mitochondrial reactive oxygen species production and bioenergetics, as well as the role of AMP kinase as an energy sensor upstream of mammalian target of rapamycin, the master regulator of protein synthesis.

scholarly journals Unexpected Role of the Copper Transporter ATP7A in PDGF-Induced Vascular Smooth Muscle Cell Migration

2010 ◽  
Vol 107 (6) ◽  
pp. 787-799 ◽  
Author(s):  
Takashi Ashino ◽  
Varadarajan Sudhahar ◽  
Norifumi Urao ◽  
Jin Oshikawa ◽  
Gin-Fu Chen ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Cell Migration ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cell ◽  
Muscle Cell ◽  
Vascular Smooth Muscle Cell ◽  
Copper Transporter ◽  
Smooth Muscle Cell Migration

The essential role of p21 in radiation-induced cell cycle arrest of vascular smooth muscle cell

2004 ◽  
Vol 37 (4) ◽  
pp. 871-880 ◽  
Author(s):  
Hyo-Soo Kim ◽  
Hyun-Jai Cho ◽  
Hyun-Ju Cho ◽  
Sun-Jung Park ◽  
Kyung-Woo Park ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cell ◽  
Cell Cycle Arrest ◽  
Muscle Cell ◽  
Essential Role ◽  
Cycle Arrest ◽  
Radiation Induced

scholarly journals Pathophysiological Role of Vascular Smooth Muscle Alkaline Phosphatase in Medial Artery Calcification

2015 ◽  
Vol 30 (5) ◽  
pp. 824-836 ◽  
Author(s):  
Campbell R Sheen ◽  
Pia Kuss ◽  
Sonoko Narisawa ◽  
Manisha C Yadav ◽  
Jessica Nigro ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Pathophysiological Role ◽  
Medial Artery Calcification ◽  
Medial Artery
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