Vasopressin stimulates tyrosine phosphorylation by activation of PKC in the rat smooth muscle cell line, A-10

Arginine vasopressin (AVP)-induced tyrosine phosphorylation was studied in a rat smooth muscle cell line, A-10, by western blotting, using a monoclonal antibody against phosphotyrosine. AVP stimulated the phosphorylation of several cellular proteins of molecular mass 60-130 kDa in a time- and dose-dependent manner. Phosphorylation was mediated largely by V(1)receptor subtype since it was inhibited by selective V(1)antagonist and was only partially elicited by the V(2)agonist, desmopressin. Heterotrimeric G-proteins seemed to be involved in the phosphorylation mechanism because fluoraluminates, an activator of heterotrimeric G-proteins (and thus an uncoupler of the receptor-G-protein interaction) inhibited the AVP-induced phosphorylation. The protein kinase C (PKC) inhibitors: staurosporine, H7 and GF109203X are able to block the AVP-stimulated phosphorylation. The last of these has been shown to be one of the most selective inhibitors of PKC. These results indicate that PKC is upstream of the phosphorylation, a motion which is supported by the fact that the AVP-stimulated phosphorylation was downregulated by phorbol esters.     

Glucocorticoid amplifies vasopressin-induced phosphoinositide hydrolysis in aortic smooth muscle cells

It has been reported that glucocorticoid modifies phosphoinositide (PI) hydrolysis stimulated by vasoactive agents in vascular smooth muscle cells. In the present study, we investigated the point at which glucocorticoid affects vasopressin-induced PI hydrolysis in primary cultured rat aortic smooth muscle cells. The pretreatment with dexamethasone significantly amplified the formation of inositol trisphosphate (IP₃) induced by vasopressin in a dose-dependent manner in a range of 1 pM to 10 nM. The effect of dexamethasone was dependent on the time of pretreatment up to 8 h. Dexamethasone had little effect on the number of vasopressin receptor and its affinity to vasopressin. The pretreatment with dexamethasone also amplified the formation of IP₃ induced by NaF, a GTP-binding protein activator, or angiotensin II. 12-O-Tetradecanoylphorbol-13-acetate, a protein kinase C (PKC)-activating phorbol ester, significantly reduced the dexamethasone-induced enhancement of IP₃ formation stimulated by vasopressin, angiotensin II or NaF. 4α-Phorbol-12, 13-didecanoate, a PKC-nonactivating phorbol ester, had little effect on the enhancement by dexamethasone. These results strongly suggest that glucocorticoid amplifies vasopressin-induced PI hydrolysis at a point downstream from GTP-binding protein in primary cultured rat aortic smooth muscle cells, and that the activation of PKC has a negative feedback effect on the amplification by glucocorticoid of vasopressin-induced PI hydrolysis.     

Possible involvement of phosphatidylinositol 3-kinase/Akt signal pathway in vasopressin-induced HSP27 phosphorylation in aortic smooth muscle A10 cells

We previously reported that p38 mitogen-activated protein (MAP) kinase takes a part in arginine vasopressin (AVP)-induced heat shock protein 27 (HSP27) phosphorylation in aortic smooth muscle A10 cells. In the present study, we investigated whether phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) is involved in the phosphorylation of HSP27 in these cells. AVP time-dependently induced the phosphorylation of PI3K and Akt. Akt inhibitor, 1l-6-hydroxymethyl-chiro-inositol 2-(R)-2-O-methyl-3-O-octadecylcarbonate, partially suppressed the phosphorylation of HSP27. The AVP-induced HSP27 phosphorylation was attenuated by LY294002, a PI3K inhibitor. The combination of Akt inhibitor and SB203580, a p38 MAP kinase inhibitor, completely suppressed the AVP-induced phosphorylation of HSP27. Furthermore, LY294002 or Akt inhibitor did not affect the AVP-induced phosphorylation of p38 MAP kinase and SB203580 did not affect the phosphorylation of PI3K or Akt. These results suggest that PI3K/Akt plays a part in the AVP-induced phosphorylation of HSP27, maybe independently of p38 MAP kinase, in aortic smooth muscle A10 cells.     

Modulation of DNA synthesis in aortic smooth muscle cells by dinitrotoluenes

Studies were conducted to determine if in vivo exposure to dinitrotoluenes (DNT), which is associated with circulatory disorders of atherosclerotic etiology in humans, is associated with alterations of vascular smooth muscle cells (SMC) consistent with the atherogenic process. Sprague-Dawley rats (150-180 g) were injected IP for 5 days/week for 8 weeks with 2,4- or 2,6-DNT (0.5, 5, or 10 mg/kg) or medium chain triglyceride (MCT) oil. Histopathologic evaluation of aortae from animals exposed to either isomer showed dysplasia and rearrangement of SMC at all doses tested. Reduced ³H-thymidine incorporation was observed in primary cultures of aortic SMC from DNT-exposed animals relative to vehicle controls. This inhibitory response was maintained for up to two passages in culture after which a significant increase in thymidine incorporation was observed. Exposure of SMC from naive animals to DNT in vitro (1–100 µM) did not alter the extent of thymidine incorporation in cycling or growth-arrested cultures. In contrast, exposure to 2,4- or 2,6-diaminotoluene (DAT) (1–100 µM), carcinogens which share toxic metabolic intermediates in common with DNT, inhibited replicative DNA synthesis and stimulated unscheduled DNA synthesis in cycling and growth-arrested cultures of SMC, respectively. Our results suggest that modulation of DNA synthesis in aortic SMC by DNT metabolites generated in vivo contribute to the development of vascular lesions.Abbreviation DAT diaminotuluene - tDNT technical grade dinitrotoluene - DNT dinitrotoluenes - HU hydroxyurea - IP intraperitoneal - LDH lactate dehydrogenase - MCT oil medium chain triglyceride - NPTC non-protein thiol content - RDS replicative DNA synthesis - SEM standard error of the mean - SMC smooth muscle cells - UDS unscheduled DNA synthesis     

Adenylyl cyclase-cAMP system inhibits thrombin-induced HSP27 in vascular smooth muscle cells

We previously reported that thrombin stimulates the induction of heat shock protein (HSP) 27 via p38 mitogen-activated protein (MAP) kinase activation in aortic smooth muscle A10 cells. In the present study, we investigated the effect of the adenylyl cyclase-cAMP system on the thrombin-stimulated induction of HSP27 in A10 cells. Forskolin, a direct activator of adenylyl cyclase, reduced the thrombin-induced p38 MAP kinase phosphorylation, and significantly suppressed the thrombin-stimulated accumulation of HSP27. However, dideoxyforskolin, a forskolin derivative that does not activate cAMP, failed to suppress the HSP27 accumulation. Furthermore, dibutyryl-cAMP (DBcAMP), a permeable analog of cAMP, significantly suppressed the accumulation of HSP27. On the other hand, calphostin C, an inhibitor of protein kinase C (PKC), reduced the thrombin-induced p38 MAP kinase phosphorylation, and significantly suppressed the thrombin-stimulated accumulation of HSP27. Moreover, forskolin reduced the p38 MAP kinase phosphorylation induced by the 12-O-tetradecanoylphorbol-13-acetate (TPA), a PKC-activating phorbol ester, and significantly suppressed the TPA-stimulated accumulation of HSP27. These results indicate that adenylyl cyclase-cAMP system has an inhibitory role in thrombin-stimulated HSP27 induction in aortic smooth muscle cells, and the effect seems to be exerted on the thrombin-induced PKC- p38 MAP kinase signaling pathway.     

Involvement of p38 MAP kinase in TGF-beta-stimulated VEGF synthesis in aortic smooth muscle cells

Although it is known that transforming growth factor (TGF)-beta induces vascular endothelial growth factor (VEGF) synthesis in vascular smooth muscle cells, the underlying mechanisms are still poorly understood. In the present study, we examined whether the mitogen-activated protein (MAP) kinase superfamily is involved in TGF-beta-stimulated VEGF synthesis in aortic smooth muscle A10 cells. TGF-beta stimulated the phosphorylation of p42/p44 MAP kinase and p38 MAP kinase, but not that of SAPK (stress-activated protein kinase)/JNK (c-Jun N-terminal kinase). The VEGF synthesis induced by TGF-beta was not affected by PD98059 or U0126, specific inhibitors of the upstream kinase that activates p42/p44 MAP kinase. We confirmed that PD98059 or U0126 did actually suppress the phosphorylation of p42/p44 MAP kinase by TGF-beta in our preparations. PD169316 and SB203580, specific inhibitors of p38 MAP kinase, significantly reduced the TGF-beta-stimulated synthesis of VEGF (each in a dose-dependent manner). PD169316 or SB203580 attenuated the TGF-beta-induced phosphorylation of p38 MAP kinase. These results strongly suggest that p38 MAP kinase plays a part in the pathway by which TGF-beta stimulates the synthesis of VEGF in aortic smooth muscle cells.     

pp60c-src在血管平滑肌细胞内丝裂原活化蛋白激酶激活中的作用

观察ｐｐ６０ｃ－ｓｒｃ在血管紧张素Ⅱ（ＡｎｇⅡ）诱导血管平滑肌细胞（ＶＳＭＣｓ）内丝裂原活化蛋白激酶（ＭＡＰＫ）激活中的作用,以了解ＡｎｇⅡ促ＶＳＭＣｓ增殖的信号转导过程。将合成的反义ｃ－ｓｒｃ寡脱氧核苷酸（ｏｌｉｇｏｄｅｏｘｙｎｕｃｌｅ－ｏｔｉｄｅｓ,ＯＤＮｓ）以脂质体包裹转染培养的大鼠ＶＳＭＣｓ,用Ｗｅｓｔｅｒｎ印迹测得细胞裂解液中ｐｐ６０ｃ－ｓｒｃ含量明显下降,免疫沉淀方法测得ｐｐ６０ｃ－ｓ     

Cyclic strain stimulates monocyte chemotactic protein‐1 mRNA expression in smooth muscle cells

Hemodynamic forces are important determinants for the formation of atherosclerotic plaques. The recruitment of circulating monocytes into the arterial wall is an important step during atherogenesis. Monocyte chemotactic protein‐1 (MCP‐1) has been shown to be a key factor for monocyte transmigration. This study examined the effects of cyclic strain on MCP‐1 mRNA expression levels of cultured rat aortic smooth muscle cells. The MCP‐1 mRNA levels of aortic smooth muscle cells first increased as the duration of cyclic strain increased, reaching the maximum at 6–12 h, maintained at high levels throughout the 48‐h strain period. To explore signaling pathways mediating cyclic strain‐stimulated MCP‐1 mRNA expression, we examined the involvement of tyrosine kinase and protein kinase C (PKC). Tyrosine kinase inhibitors, genistein and tyrphostin 51, at 50 μM blocked cyclic strain‐stimulated MCP‐1 mRNA expression. Preincubation with a PKC activator, phorbol 12‐myristate 13‐acetate (PMA), 2 μM, for 24 h to downregulate PKC did not decrease cyclic strain‐induced MCP‐1 mRNA expression. A 6‐h incubation with 0.1 μM PMA to activate PKC, which stimulated MCP‐1 expression when applied alone, abolished the stimulatory effects of cyclic strain. A specific PKC inhibitor, calphostin C (0.1 μM), diminished cyclic strain‐stimulated MCP‐1 mRNA expression. Angiotensin II at 10 or 1,000 nM induced a moderate upregulation of MCP‐1 mRNA, and no synergistic effects were observed between angiotensin II and cyclic strain. These results indicate that cyclic strain stimulates MCP‐1 mRNA expression in smooth muscle cells through signaling pathway(s) mediated by tyrosine kinase activation. J. Cell. Biochem. 76:303–310, 1999. © 1999 Wiley‐Liss, Inc.     

胰岛素影响自发性高血压大鼠血管平滑肌细胞增殖及肌动蛋白分布的丝裂原激酶的机制探讨

血管平滑肌细胞增殖的同时伴有细胞内肌动蛋白的改变,这种改变受PKC-MAPK信号转导途径调控,但目前机制尚不清楚。为探讨胰岛素对PKC-MAPK信号转导途径参与调控血管平滑肌细胞增殖及细胞内肌动蛋白分布的影响,本研究用PKC抑制剂预处理SHR在鼠体外培养的血管平滑肌细胞,观察预处理的血管平滑肌细胞经胰岛素刺激后细胞内DNA的合成、MAPK的活性、表达及细胞内肌动蛋白的分布。发现,胰岛素刺激后可使血管平滑肌细胞增殖,同时伴有[^3H]TdR掺入增加、MAPK活性及表达与对照组比较明显升高。这些作用可被PKC抑制剂阻断。胰岛素在刺激血管平滑肌细胞增殖的同时也使细胞内肌动蛋白重新分布,这一效应也可被PKC抑制剂阻断。 上述结果提示,胰岛素使血管平滑肌细胞增殖的效应可能与MAPK信号转导途径有关。     

青藤碱对家兔主动脉血管平滑肌细胞内游离钙浓度及蛋白激酶C的影响

观测青藤碱对培养家兔血管平滑肌细胞内游离钙浓度及正常和缺血缺氧刺激下蛋白激酶C（PKC）活性的影响。方法：Fura-2／AM作Ca^2＋指示剂,检测青藤碱对培养家兔主动脉血管平滑肌细胞静息Ca^2＋浓度及去甲肾上腺素,高K^＋,咖啡因刺激作用下的改变,并与钙拮抗剂维拉帕米进行对照研究;复制血管平滑肌细胞缺血缺氧模型,液闪仪测定PKC活性。结果：青藤碱剂量依赖性抑制高K^＋去极化引起[Ca^2＋]i升高,青藤碱10×10^-6mol.L^-1、3×10^-5mol.L^-1、10^-4mol.L^-1,对NE通过受体介导引起的[Ca^2＋]i增高也有明显抑制。但对静息状态下及咖啡因刺激的血管平滑肌细胞[Ca^2＋]i无明显影响。正常时,青藤碱处理后血管平滑肌细胞胞浆、胞膜PKC活性均升高;缺血缺氧状态下,胞浆PKC活性升高,但胞膜PKC活性降低,青藤碱处理后胞浆PKC活性下降,胞膜PKC活性上升。结论：青藤碱可能抑制血管平滑肌细胞电压依赖性钙通道和受体操纵性钙通道,降低细胞内游离钙水平。调节缺血缺氧条件下血管平滑肌细胞PKC活性。     

一氧化氮抑制内皮素促血管平滑肌细胞增殖作用的信号转导途径

培养的家兔胸主动脉血管平滑肌细胞（ＶＳＭＣ）分别以内皮素（ＥＴ－１）、一氧化氮（ＮＯ）前体Ｌ－Ａｒｇ和ＮＯ供体ＳＩＮ－１刺激,或用ＥＴ－１＋Ｌ－Ａｒｇ、ＥＴ－１＋ＳＩＮ－１联合刺激,测ＶＳＭＣ＾３Ｈ－ＴｄＲ掺入、丝裂素活化蛋白激酶（ＭＡＰＫ）活性及蛋白激酶Ｃ（ＰＫＣ）活性的改变,以研究ＮＯ抑制ＥＴ－１促ＶＳＭＣ增殖作用的信号转导途径。结果表明：（１）ＥＴ－１ １０＾－８ｍｏｌ／Ｌ单独刺激,＾３Ｈ－     

Vasopressin Stimulates the Induction of Heat Shock Protein 27 and αB-Crystallin via Protein Kinase C Activation in Vascular Smooth Muscle Cells

In the present study, we examined the effect of vasopressin on the induction of the low-molecular-weight heat shock proteins heat shock protein 27 (HSP27) and αB-crystallin in an aortic smooth muscle cell line, A10 cells. Vasopressin induced a time-dependent accumulation of HSP27 and αB-crystallin. The stimulatory effects of vasopressin were dose-dependent over the range 0.1 nmol/L to 0.1 μmol/L. The EC₅₀values for vasopressin were 2 (HSP27) and 4 nmol/L (αB-crystallin). Vasopressin induced increases in the levels of the mRNAs for HSP27 and αB-crystallin. 12-O-Tetradecanoylphorbol 13-acetate (TPA), a protein kinase C (PKC)-activating phorbol ester, induced an accumulation of HSP27 (EC₅₀, 20 nmol/L) and αB-crystallin (EC₅₀, 2 nmol/L). In contrast, 4α-phorbol 12,13-didecanoate, a non-PKC-activating phorbol ester, had no such effect. Staurosporine and calphostin C, inhibitors of PKC, significantly reduced the vasopressin-induced accumulation of HSP27 and αB-crystallin as well as that induced by TPA. BAPTA/AM and TMB-8, inhibitors of intracellular Ca²⁺mobilization, significantly reduced the vasopressin-induced accumulation of HSP27 and αB-crystallin. These results strongly suggest that vasopressin stimulates the induction of HSP27 and αB-crystallin via PKC activation in vascular smooth muscle cells and that this effect of vasopressin is dependent on intracellular Ca²⁺mobilization.     

Visualization of stimulus‐specific heterogeneous activation of individual vascular smooth muscle cells in aortic tissues

Intercellular communication among autonomic nerves, endothelial cells (ECs), and vascular smooth muscle cells (VSMCs) plays a central role in an uninterrupted regulation of blood flow through vascular contractile machinery. Impairment of this communication is linked to development of vascular diseases such as hypertension, cerebral/coronary vasospasms, aortic aneurism, and erectile dysfunction. Although the basic concept of the communication as a whole has been studied, the spatiotemporal correlation of ECs/VSMCs in tissues at the cellular level is unknown. Here, we show a unique VSMC response to ECs during contraction and relaxation of isolated aorta tissues through visualization of spatiotemporal activation patterns of smooth muscle myosin II. ECs in the intimal layer dictate the stimulus‐specific heterogeneous activation pattern of myosin II in VSMCs within distinct medial layers. Myosin light chain (MLC) phosphorylation (active form of myosin II) gradually increases towards outer layers (approximately threefold higher MLC phosphorylation at the outermost layer than that of the innermost layer), presumably by release of an intercellular messenger, nitric oxide (NO). Our study also demonstrates that the MLC phosphorylation at the outermost layer in spontaneously hypertensive rats (SHR) during NO‐induced relaxation is quite high and approximately 10‐fold higher than that of its counterpart, the Wister–Kyoto rats (WKY), suggesting that the distinct pattern of myosin II activation within tissues is important for vascular protection against elevated blood pressure.     

Vascular smooth muscle cells direct extracellular dysregulation in aortic stiffening of hypertensive rats

Aortic stiffening is an independent risk factor that underlies cardiovascular morbidity in the elderly. We have previously shown that intrinsic mechanical properties of vascular smooth muscle cells (VSMCs) play a key role in aortic stiffening in both aging and hypertension. Here, we test the hypothesis that VSMCs also contribute to aortic stiffening through their extracellular effects. Aortic stiffening was confirmed in spontaneously hypertensive rats (SHRs) vs. Wistar‐Kyoto (WKY) rats in vivo by echocardiography and ex vivo by isometric force measurements in isolated de‐endothelized aortic vessel segments. Vascular smooth muscle cells were isolated from thoracic aorta and embedded in a collagen I matrix in an in vitro 3D model to form reconstituted vessels. Reconstituted vessel segments made with SHR VSMCs were significantly stiffer than vessels made with WKY VSMCs. SHR VSMCs in the reconstituted vessels exhibited different morphologies and diminished adaptability to stretch compared to WKY VSMCs, implying dual effects on both static and dynamic stiffness. SHR VSMCs increased the synthesis of collagen and induced collagen fibril disorganization in reconstituted vessels. Mechanistically, compared to WKY VSMCs, SHR VSMCs exhibited an increase in the levels of active integrin β1‐ and bone morphogenetic protein 1 (BMP1)‐mediated proteolytic cleavage of lysyl oxidase (LOX). These VSMC‐induced alterations in the SHR were attenuated by an inhibitor of serum response factor (SRF)/myocardin. Therefore, SHR VSMCs exhibit extracellular dysregulation through modulating integrin β1 and BMP1/LOX via SRF/myocardin signaling in aortic stiffening.     

Different signaling responses to anti-proliferative agents in human aortic and venous smooth muscle cells

Proliferation of smooth muscle cells (SMCs) contributes to the stenosis of coronary arteries and vascular grafts. Local delivery of anti-proliferative drugs can prevent vascular stenosis. To understand the cellular responses to anti-proliferative agents, we investigated the signaling events in cultured human aortic SMCs (ASMCs), saphenous venous SMCs (VSMCs), and dermal fibroblasts (DFs) in response to paclitaxel or etoposide. Cellular mitochondrial and proliferative activities were examined with the methylthiazoletetrazolium (MTT) dye reduction and the bromodeoxyuridine (BrdU) incorporation assay, respectively. Cell proliferation was almost completely suppressed by paclitaxel or etoposide, but apoptosis was achieved in only about 50% of cells at the highest drug concentrations, suggesting the presence of compensatory mechanisms to prevent apoptosis. Examination of three important signaling pathways revealed significant differences between ASMCs, VSMCs, and DFs. Treatment with either paclitaxel or etoposide caused a transient phosphorylation/activation of p42 MAPK in ASMCs and DFs, but had no effect on phospho-p42/44 MAPK in VSMCs. High-dose etoposide enhanced p38 MAPK activation in ASMCs, but not in VSMCs. The p38 inhibitor, PD169316, partially inhibited etoposide-induced ASMC apoptosis, but induced apoptosis in VSMCs. The effects of etoposide and paclitaxel on Akt also differed between ASMCs and VSMCs. These observations indicate that ASMCs and VSMCs differ in the response of signaling pathways to anti-proliferative agents. In ASMCs, p42/44 MAPK appears to serve a pro-survival role, whereas p38 MAPK is a pro-apoptotic regulator. In contrast, p38 MAPK is an important pro-survival regulator in VSMCs and p42/44 MAPK appears to play a minor role in responding to anti-proliferative drugs.     

A single-cell transcriptomic inventory of murine smooth muscle cells

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蛋白激酶C和蛋白酪氨酸激酶介导脂多糖及细胞因子诱导大鼠血管平滑肌细胞一氧化氮的生成

采用Spprague-Dawley大鼠胸主动脉中膜、外膜和培养的血管平滑肌细胞(VSMCs)作材料,鉴定不同类型的血管组织经炎性介质刺激后其一氧化氮(NO)的产生来源,闻明蛋白激酶C(PKC)和蛋白酪氨酸激酶(PTK)介导大鼠VSMCs生成NO的调控机制。大鼠VSMCs经脂多糖(LPG)和细胞因子(TNF-α,IL-1β)处理后,以剂量依赖方式促进NO释放。采用Western Blot证实经刺激的VSMCs伴有iNOS表达上调。进一步实验表明PKC和PTK参与LPS和细胞因子诱导NO生成的胞内信号转导。用PKC抑制剂H7与VSMCs共培育,H7能明显减少LPS、TNF-α和IL-1β诱导细胞NO的形成。白屈菜赤碱亦可抑制NO的生成,但HAl004对VSMCs的NO生成无抑制作用,提示PKC参与NO的生成与调控。PTK抑制剂genistein和tyrphostin AG18均能抑制由LPS、TNF-α和IL-1β引发VSMCs释放NO,同时伴iNOS蛋白表达下调,而PKC抑制剂不能阻断iNOS的表达。上述观察结果提示,PKC介导LPS和细胞因子诱导细胞合成NO可能是通过iNOS翻译后加工;而PTK则以上调iNOS表达而促增NO生成。     

白介素-10抑制TNF-α诱导的血管平滑肌细胞增殖

研究观察了重组人白介素 10 (rhIL 10 )对肿瘤坏死因子 (TNF α)刺激的离体大鼠胸主动脉血管平滑肌细胞增殖、细胞周期及对p4 4 /p4 2丝裂素活化蛋白激酶的影响。实验培养大鼠主动脉血管平滑肌细胞 ,采用MTS/PES法确定血管平滑肌细胞 (vascularsmoothmusclecells,VSMCs)的增殖状态 ;应用流式细胞术测定细胞周期 ;利用p4 4 / 4 2磷酸化抗MAPK抗体的蛋白免疫印迹法测定MAPK蛋白表达。结果显示 :( 1)TNF α处理组与对照组相比 ,TNF α对VSMC增殖具有明显的刺激作用 (P <0 0 5 )。rhIL 10单独应用对VSMCs生长没有影响 (P >0 0 5 )。在TNF α刺激下 ,低至 10ng/ml的rhIL 10可抑制VSMCs的生长 (P <0 0 5 )。流式细胞术测定的结果显示 ,rhIL 10分别可使TNF α作用下的VSMC大部分处于G0 /G1期 ,与对照组相比有明显差异 (P <0 0 1)。 ( 2 )TNF α对p4 4 /p4 2MAPK蛋白表达有显著的增强作用 ,此作用可被rhIL 10抑制。结果提示 ,rhIL 10可抑制TNF α诱导的VSMC增殖及p4 4 /p4 2丝裂素活化蛋白激酶的表达     

血管紧张素-(1-7)对大鼠血管平滑肌细胞PKC和ERK1/2的抑制作用

采用Westernblot、氚 胸腺嘧啶 ( 3H TdR)和氚 亮氨酸 ( 3H Leu )掺入等技术和方法 ,用血管紧张素Ⅱ(AngⅡ )和血管紧张素 ( 1 7) [Ang ( 1 7) ]刺激大鼠血管平滑肌细胞 (VSMCs) ,观察和分析Ang ( 1 7)对VSMCs增殖及蛋白激酶C (PKC)和胞外调节蛋白激酶 (ERK)表达的影响。Ang ( 1 7)能明显抑制基础和AngⅡ刺激下的VSMCsPKC ζ和ERK1/ 2蛋白表达 (P <0 0 1或P <0 0 5 ) ,减少3H TdR和3H Leu掺入量 (P <0 0 1或P <0 0 5 )。结果提示 ,Ang ( 1 7)对VSMCs增殖有抑制作用 ,这可能与影响PKC ζ和ERK1/ 2蛋白表达有关。