Peroxide resistance of ER Ca2+ pump in endothelium: implications to coronary artery function

1997 ◽  
Vol 273 (4) ◽  
pp. C1250-C1258 ◽  
Author(s):  
Ashok K. Grover ◽  
Sue E. Samson
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Coronary Artery ◽  
Smooth Muscle Cells ◽  
Cultured Cells ◽  
Contractile Function ◽  
Ischemia Reperfusion ◽  
Muscle Cells ◽  
Intact Cells ◽  
Serca Pump

We examined the effects of peroxide on the sarco(endo)plasmic reticulum Ca2+ (SERCA) pump in pig coronary artery endothelium and smooth muscle at three organizational levels: Ca2+ transport in permeabilized cells, cytosolic Ca2+ concentration in intact cells, and contractile function of artery rings. We monitored the ATP-dependent, azide-insensitive, oxalate-stimulated45Ca2+uptake by saponin-permeabilized cultured cells. Low concentrations of peroxide inhibited the uptake less effectively in endothelium than in smooth muscle whether we added the peroxide directly to the Ca2+ uptake solution or treated intact cells with peroxide and washed them before the permeabilization. An acylphosphate formation assay confirmed the greater resistance of the SERCA pump in endothelial cells than in smooth muscle cells. Pretreating smooth muscle cells with 300 μM peroxide inhibited (by 77 ± 2%) the cyclopiazonic acid (CPA)-induced increase in cytosolic Ca2+ concentration in a Ca2+-free solution, but it did not affect the endothelial cells. Peroxide pretreatment inhibited the CPA-induced contraction in deendothelialized arteries with a 50% inhibitory concentration of 97 ± 13 μM, but up to 500 μM peroxide did not affect the endothelium-dependent, CPA-induced relaxation. Similarly, 500 μM peroxide inhibited the angiotensin-induced contractions in deendothelialized arteries by 93 ± 2%, but it inhibited the bradykinin-induced, endothelium-dependent relaxation by only 40 ± 13%. The greater resistance of the endothelium to reactive oxygen may be important during ischemia-reperfusion or in the postinfection immune response.

Abstract 524: Extracellular Guanosine Regulates Extracellular Adenosine Levels

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Edwin K Jackson ◽  
Delbert G Gillespie
Keyword(s):  
Blood Pressure ◽  
Endothelial Cells ◽  
Smooth Muscle ◽  
Coronary Artery ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Muscle Cells ◽  
Extracellular Adenosine ◽  
Arterial Blood

Extracellular adenosine modulates cardiovascular and renal function. While measuring extracellular purines in biological samples, we observed a correlation between levels of adenosine and guanosine. This observation led us to test the hypothesis that extracellular guanosine regulates extracellular adenosine levels in the cardiovascular and renal systems. Rat preglomerular vascular smooth muscle cells in culture were incubated with adenosine and/or guanosine. In the absence of added adenosine, exogenous guanosine (30 μmol/L) had little effect on extracellular adenosine levels, indicating that extracellular guanosine does not trigger the release or production of adenosine. Without added guanosine and 1 hour after adding 3 μmol/L of exogenous adenosine, extracellular adenosine levels were only 0.125 ± 0.020 μmol/L, indicating rapid disposition of extracellular adenosine by a monolayer of cells. In contrast, extracellular adenosine levels 1 hour after adding 3 μmol/L of adenosine plus guanosine (30 μmol/L) were 1.173 ± 0.061 μmol/L (9-fold higher; p<0.0001), indicating slow disposition of extracellular adenosine in the presence of extracellular guanosine. Extracellular guanosine impeded the disposition of extracellular adenosine not only in preglomerular vascular smooth muscle cells, but also in rat preglomerular vascular endothelial cells, mesangial cells, cardiac fibroblasts and kidney epithelial cells, as well as in human aortic vascular smooth muscle cells, coronary artery vascular smooth muscle cells and coronary artery endothelial cells. In rats, infusions of guanosine per se had little effect on cardiovascular/renal variables, yet markedly enhanced the effects of co-infusions of adenosine. For example, in control rats, adenosine (0.3 μmol/kg/min) only modestly decreased mean arterial blood pressure (from 114 ± 4 to 100 ± 4 mm Hg). In contrast, in guanosine-treated rats (10 μmol/kg/min), adenosine profoundly decreased blood pressure (from 109 ± 4 to 79 ± 3 mm Hg; p<0.0001 vs non-guanosine treated group). Conclusion: Extracellular guanosine powerfully regulates extracellular adenosine levels by altering adenosine disposition and this occurs in many, perhaps most, cell types in the cardiovascular system and kidneys.

Abstract 180: The Myristolated Alanine-Rich C Kinase Substrate (MARCKS) Differentially Regulates Proliferation of Vascular Smooth Muscle Cells and Endothelial Cells through Affecting Protein Stability and Proteolytic Processing of the Kinase Interacting with Stathmin (KIS)

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Dan Yu ◽  
Charles Drucker ◽  
Rajabrata Sarkar ◽  
Dudley K Strickland ◽  
Thomas S Monahan
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Coronary Artery ◽  
Smooth Muscle Cells ◽  
Protein Stability ◽  
Muscle Cells ◽  
Cell Types ◽  
Proteolytic Processing ◽  
Functional Domain ◽  
Human Coronary Artery

Objective: Presently, the antiproliferative agents used in drug eluting stents and drug coated balloons inhibit both VSMC and endothelial cell (EC) proliferation, and thus these patients require dual antiplatelet therapy indefinitely. Identification of a VSMC-specific target to prevent proliferation represents a significant unmet clinical need. Previously we found that knockdown of MARCKS arrests VSMC proliferation through a p27 kip1 -dependent mechanism. Interestingly MARCKS knockdown increases EC proliferation. p27 kip1 is phosphorylated by KIS allowing it to exit the nucleus and be degraded. Here we seek to understand how MARCKS influences KIS protein expression in these two cell types. Approach and Results: We performed siRNA-mediated knock down of MARCKS in human coronary artery endothelial cells (CAECs) and human coronary artery smooth muscle cells (CASMCs). MARCKS knockdown did not affect KIS mRNA expression as determined with RT-PCR in either cell type. KIS protein stability was evaluated in the presence of cyclohexamide with Western blot. In CAECs, MARCKS knockdown increased KIS stability, however, in CASMCs, MARCKS knockdown significantly decreased KIS protein stability. In CASMCs, MARCKS knockdown significantly increased KIS ubiquitinization where as in CAECs, MARCKS knockdown decreased KIS ubiquitinization. Interestingly, the well-studied functional domain of MARCKS(ED domain) is not directly involved in KIS regulation. MARCKS mutants (S4G and S4D) rescued proliferation in VSMCs. MARCKS knockdown in vivo in the murine femoral wire injury model resulted in decreased medial bromodeoxyuridine (BrdU) integration and neointima formation. MARCKS knockdown enhanced endothelial barrier function recovery four days after injury as assessed by Evans Blue integration. Conclusions: MARCKS differentially regulates the protein stability and proteolytic processing of KIS in VSMCs and ECs. The differential interaction of MARCKS and KIS likely explains the observed difference in proliferation observed with MARCKS knockdown in these two cell types.

scholarly journals APOPTOSIS CELLS OF CORONARY ARTERY WALL AS DEVELOPING AND PROGRESSING FACTOR OF CORONARY SCLEROSIS

2013 ◽  
Vol 68 (9) ◽  
pp. 22-26
Author(s):  
T. E. Vladimirskaya ◽  
I. A. Shved ◽  
S. G. Krivorot
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Coronary Artery ◽  
Smooth Muscle Cells ◽  
Coronary Arteries ◽  
Muscle Cells ◽  
Artery Wall ◽  
Paraffin Sections ◽  
Early Stages ◽  
Coronary Artery Wall

Objective: to study apoptosis of individual cellular components of the vascular wall of coronary arteries at different morphological stages of atherosclerosis. Material and methods. The study was performed on coronary arteries taken from 52 deceased patients with atherosclerosis and coronary heart disease at different stages of atherogenesis. For morphological study prepared paraffin sections, which were stained for morphological studies were prepared paraffin sections, which were stained with hematoxylin and eosin, by Van Gieson, Masson, on lipids with Sudan black B, according to Van Cossu. .To determine apoptosis, TUNEL method used in paraffin sections. Apoptotic index (AI) was calculated by TUNEL-positive cells and the average inner shell coronary artery around the perimeter each with increasing microscopic 1000. Results. Investigation showed significant apoptosis (p 0.05) increase in AI smooth muscle, endothelial cells, macrophages in the coronary arteries affected by atherosclerosis compared to intact control group vascular segments significant reduction AI endothelial, smooth muscle cells and macrophages (p  0,05) traced from the early stages of atherogenic disorders to atheromatosis. Conclusions. It is established that apoptosis of smooth muscle cells, macrophages and endothelial cells is the most intensive on early stages of atherosclerotic process. In process of progressing of atherosclerosis intensity and prevalence of apoptosis of coronary artery wall cells decreases, and processes of necrosis becomes predominant. Apoptosis of coronary artery wall cells is valuable in increasing the zones of atheromatosis, plaque destabilizations, and also increases the risk of thrombosis and ulcerations. 

scholarly journals Calcium pump of the plasma membrane is localized in caveolae.

1993 ◽  
Vol 120 (5) ◽  
pp. 1147-1157 ◽  
Author(s):  
T Fujimoto
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Plasma Membrane ◽  
Smooth Muscle Cells ◽  
Cultured Cells ◽  
Muscle Cells ◽  
Epidermal Keratinocytes ◽  
Cardiac Muscle Cells ◽  
Mouse Tissues ◽  
Visceral Smooth Muscle

The Ca2+ pump in the plasma membrane plays a key role in the fine control of the cytoplasmic free Ca2+ concentration. In the present study, its subcellular localization was examined with immunocytochemical techniques using a specific antibody generated against the erythrocyte membrane Ca2+ pump ATPase. By immunofluorescence microscopy of cultured cells, the labeling with the antibody was seen as numerous small dots, often distributed in linear arrays or along cell edges. Immunogold EM of cryosections revealed that the dots correspond to caveolae, or smooth invaginations of the plasma membrane. The same technique applied to mouse tissues in vivo showed that the Ca2+ pump is similarly localized in caveolae of endothelial cells, smooth muscle cells, cardiac muscle cells, epidermal keratinocytes and mesothelial cells. By quantitative analysis of the immunogold labeling, the Ca2+ pump in capillary endothelial cells and visceral smooth muscle cells was found to be concentrated 18-25-fold in the caveolar membrane compared with the noncaveolar portion of the plasma membrane. In renal tubular and small intestinal epithelial cells, which have been known to contain the Ca2+ pump but do not have many caveolae, most of the labeling was randomly distributed in the basolateral plasma membrane, although caveolae were also positively labeled. The results demonstrate that the caveolae in various cells has the plasmalemmal Ca2+ pump as a common constituent. In conjunction with our recent finding that an inositol 1,4,5-trisphosphate receptor-like protein exists in the caveolae (Fujimoto, T., S. Nakade, A. Miyawaki, K. Mikoshiba, and K. Ogawa. 1992. J. Cell Biol. 119:1507-1513), it is inferred that the smooth plasmalemmal invagination is an apparatus specialized for Ca2+ intake and extrusion from the cytoplasm.

scholarly journals Extracellular guanosine regulates extracellular adenosine levels

2013 ◽  
Vol 304 (5) ◽  
pp. C406-C421 ◽  
Author(s):  
Edwin K. Jackson ◽  
Dongmei Cheng ◽  
Travis C. Jackson ◽  
Jonathan D. Verrier ◽  
Delbert G. Gillespie
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Coronary Artery ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Purine Nucleoside Phosphorylase ◽  
Cell Injury ◽  
Muscle Cells ◽  
Extracellular Adenosine

The aim of this investigation was to test the hypothesis that extracellular guanosine regulates extracellular adenosine levels. Rat preglomerular vascular smooth muscle cells were incubated with adenosine, guanosine, or both. Guanosine (30 μmol/l) per se had little effect on extracellular adenosine levels. Extracellular adenosine levels 1 h after addition of adenosine (3 μmol/l) were 0.125 ± 0.020 μmol/l, indicating rapid disposition of extracellular adenosine. Extracellular adenosine levels 1 h after addition of adenosine (3 μmol/l) plus guanosine (30 μmol/l) were 1.173 ± 0.061 μmol/l, indicating slow disposition of extracellular adenosine. Cell injury increased extracellular levels of endogenous adenosine and guanosine, and the effects of cell injury on endogenous extracellular adenosine were modulated by altering the levels of endogenous extracellular guanosine with exogenous purine nucleoside phosphorylase (converts guanosine to guanine) or 8-aminoguanosine (inhibits purine nucleoside phosphorylase). Extracellular guanosine also slowed the disposition of extracellular adenosine in rat preglomerular vascular endothelial cells, mesangial cells, cardiac fibroblasts, and kidney epithelial cells and in human aortic and coronary artery vascular smooth muscle cells and coronary artery endothelial cells. The effects of guanosine on adenosine levels were not mimicked or attenuated by 5-iodotubericidin (adenosine kinase inhibitor), erythro-9-(2-hydroxy-3-nonyl)-adenine (adenosine deaminase inhibitor), 5-aminoimidazole-4-carboxamide (guanine deaminase inhibitor), aristeromycin ( S-adenosylhomocysteine hydrolase inhibitor), low sodium (inhibits concentrative nucleoside transporters), S-(4-nitrobenzyl)−6-thioinosine [inhibits equilibrative nucleoside transporter (ENT) type 1], zidovudine (inhibits ENT type 2), or acadesine (known modulator of adenosine levels). Guanosine also increases extracellular inosine, uridine, thymidine, and cytidine, yet decreases extracellular uric acid. In conclusion, extracellular guanosine regulates extracellular adenosine levels.

ASSA13-03-31 In Vitro Investigations on the Effects of Arsenic Trioxide on Human Coronary Artery Smooth Muscle Cells, Endothelial Cells and EMAP-II

Heart ◽  
2013 ◽  
Vol 99 (Suppl 1) ◽  
pp. A23.3-A24
Author(s):  
Luan Tianzhu ◽  
Xu Qinglu ◽  
Fu Songbin ◽  
Li Weimin ◽  
Huang Yonglin ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Coronary Artery ◽  
Smooth Muscle Cells ◽  
Arsenic Trioxide ◽  
Muscle Cells ◽  
Human Coronary Artery ◽  
Emap Ii
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