Lysophosphatidic Acid Decreases Glutamate and Glucose Uptake by Astrocytes

Abstract: The brain is a rich source of the lipid biomediator lysophosphatidic acid, and lysophosphatidic acid levels can significantly increase following brain trauma. Responses of primary rat brain astrocytes to this novel lipid are defined in the current study. Treatment of cells with lysophosphatidic acid resulted in a time- and dose-dependent inhibition of glutamate uptake. Inhibition of glutamate uptake was specific because the related phospholipids, phosphatidic acid, lysophosphatidylcholine, and lysophosphatidylglycerol, did not inhibit this uptake under comparable conditions, i.e., treatment with 10 µ M lipid for 30 min. Lysophosphatidic acid treatment of cells resulted in an increase in lipid peroxidation, as measured by the thiobarbituric acid assay. This increase in content of thiobarbituric acid-reactive substances was largely inhibited by treatment with dithiothreitol or propyl gallate; however, such treatment did not affect the lysophosphatidic acid-induced inhibition of glutamate uptake. Lysophosphatidic acid also inhibited glucose uptake with a dose-response curve that paralleled the inhibition of glutamate uptake. By impairing uptake of glutamate by astrocytes, lysophosphatidic acid may exacerbate excitotoxic processes in various neurodegenerative conditions.     

脂联素在高糖孵育血管内皮细胞中的表达调节

目的:探讨脂联素(APN)在高糖孵育血管内皮细胞中的表达调节及意义.方法:用不同浓度葡萄糖(5.5、11、22及33mM)孵育人脐静脉内皮细胞(HUVECs),2天后收集细胞和上清液.用实时荧光定量RT-PCR方法检测细胞中APN、肿瘤坏死因子α(TNFα)和过氧化物酶体增生物激活受体γ(PPARγ)的mRNA表达,用ELISA方法检测细胞上清液中APN和TNFα分泌情况.结果:随培养液中葡萄糖浓度的升高,HUVECs中APN的mRNA表达及上清中APN蛋白含量降低(p<0.05),TNFα的mRNA表达及上清中TNFα蛋白含量增加(p<0.05),HUVECs中PPARγ的mRNA表达降低(p<0.05),且组间比较差异均有统计学意义(p<0.05).结论:高糖诱导血管内皮细胞保护性细胞因子APN表达分泌下降,可能是高糖诱导的血管内皮细胞功能损害的重要机制之一.     

Regulation of n-3 and n-6 Fatty Acid Metabolism in Retinal and Cerebral Microvascular Endothelial Cells by High Glucose

Abstract: The present study was undertaken to determine whether polyunsaturated fatty acid metabolism is affected by high glucose levels in cerebral and retinal microvascular endothelial cells. The metabolism of [3-¹⁴C]22:5n-3 and [1-¹⁴C]18:2n-6 was studied in cells previously cultured for 5 days in normal (5 m M ) or high (30 m M ) glucose medium. After incubation of retinal endothelial cells with [3-¹⁴C]22:5n-3 in the high glucose condition, the formation of labeled 24:6n-3 and 22:6n-3 was increased, and that of labeled 24:5n-3 was decreased, compared with the normal glucose condition. The changes were found for fatty acids esterified in cellular lipids and those released into the medium. After incubation with [1-¹⁴C]18:2n-6, levels of all elongation/desaturation products were increased at the expense of the precursor in retinal endothelial cells cultured in high glucose medium. The changes were primarily found for esterified fatty acids, with the release of n-6 fatty acids being minor in both glucose concentrations. By contrast, high glucose levels did not affect the metabolism of [3-¹⁴C]22:5n-3 and [1-¹⁴C]18:2n-6 in cerebral endothelial cells. The changes in metabolic activity of retinal endothelial cells were not reflected in the fatty acid composition. The present data suggest that high glucose can increase the desaturation process in retinal but not cerebral endothelial cells. This may produce some lipid abnormalities in retinal microvasculature and contribute to altered vascular function observed in diabetic retinopathy.     

Protective Effects of Salvianolic Acid B on Schwann Cells Apoptosis Induced by High Glucose

Diabetic peripheral neuropathy (DPN) is one of the most common and debilitating microvascular complications of diabetes, and there is no effective therapy for the prevention or treatment of DPN. Oxidative stress triggers several pathways of injury and may be the unifying factor of hyperglycemia. The aim of this study was to investigate protective effect of Salvianolic acid B (Sal B) on the high glucose (HG)-induced oxidative stress-induced mitochondrial pathway activation and Schwann cells (SCs) apoptosis in vitro. We found that Sal B inhibited the HG-induced oxidative stress by reducing ROS and 8-hydroxy-2-deoxy Guanosine (8-OHdG) production, and mitochondrial depolarization and apoptosis in SCs in a dose-dependent manner. Furthermore, Sal B down-regulated the HG-mediated Bax expression and AIF nuclear translocation and the release of cytochrome c, but up-regulated the HG-induced BcL-2 expression in SCs. In addition, Sal B attenuated the HG-induced activation of caspase 3 and 9 and minimized the cleavage of PARP in SCs. Our results indicated that Sal B antagonized the HG-induced oxidative stress, activation of the mitochondrial pathway and apoptosis in SCs.     

Increasing Glucose 6-Phosphate Dehydrogenase Activity Restores Redox Balance in Vascular Endothelial Cells Exposed to High Glucose

Previous studies have shown that high glucose increases reactive oxygen species (ROS) in endothelial cells that contributes to vascular dysfunction and atherosclerosis. Accumulation of ROS is due to dysregulated redox balance between ROS-producing systems and antioxidant systems. Previous research from our laboratory has shown that high glucose decreases the principal cellular reductant, NADPH by impairing the activity of glucose 6-phosphate dehydrogenase (G6PD). We and others also have shown that the high glucose-induced decrease in G6PD activity is mediated, at least in part, by cAMP-dependent protein kinase A (PKA). As both the major antioxidant enzymes and NADPH oxidase, a major source of ROS, use NADPH as substrate, we explored whether G6PD activity was a critical mediator of redox balance. We found that overexpression of G6PD by pAD-G6PD infection restored redox balance. Moreover inhibition of PKA decreased ROS accumulation and increased redox enzymes, while not altering the protein expression level of redox enzymes. Interestingly, high glucose stimulated an increase in NADPH oxidase (NOX) and colocalization of G6PD with NOX, which was inhibited by the PKA inhibitor. Lastly, inhibition of PKA ameliorated high glucose mediated increase in cell death and inhibition of cell growth. These studies illustrate that increasing G6PD activity restores redox balance in endothelial cells exposed to high glucose, which is a potentially important therapeutic target to protect ECs from the deleterious effects of high glucose.     

过表达CREG抑制高糖诱导的人脐静脉内皮细胞凋亡

目的：探讨E1A激活基因阻遏子（Cellular repressor of ElA-stimulated genes,CREG）在高糖引起的人脐静脉内皮细胞（Human Umbilical Vein Endothelial Cells,HUVECs）损伤中的作用,为寻找糖尿病血管病变新的治疗靶点提供实验依据。方法：采用胶原酶消化法分离原代HUVECs,并用内皮细胞标志物CD31免疫荧光染色进行鉴定。分别用含有5．5mmol／1葡萄糖（正常糖对照组）、5．5mmol／1葡萄糖＋27．5mmol／1甘露醇（渗透压对照组）或33mmol／l葡萄糖（高糖组）的培养液培养HUVECs48h。WesternBlot检测剪切体caspase-3表达;AnnexinV／PI双染后流式细胞术检测细胞凋亡。通过感染表达CREG基因的腺病毒获得CREG过表达的HUvECs,WesternBlot及流式细胞术评价CREG过表达对HUVECs凋亡的影响。结果：高糖处理48h后,HUVECs内剪切体caspase-3的蛋白表达增加,细胞凋亡率增加;过表达CREG后,高糖处理的HUVECs内剪切体Caspase-3表达和凋亡细胞比例均明显降低,但仍高于正常糖对照组。结论：CREG过表达可抑制高糖引起的HUVECs凋亡。     

葡萄糖和胰岛素对血管内皮细胞中microRNA-21的表达影响

目的:研究miRNA-21和程序性细胞死亡因子4(PDCD4)在不同浓度葡萄糖或胰岛素培养血管内皮细胞中的表达情况,探讨miRNA-21对内皮细胞凋亡功能的影响。方法:用不同浓度D-葡萄糖(5.5、11、22及33mM)和胰岛素(0、1、10、50、100及1000nM)分别干预人脐静脉内皮细胞(HUVECs),2天后收集细胞用实时荧光定量RT-PCR方法检测细胞中miRNA-21及PDCD4的mRNA表达情况,用蛋白印迹方法检测PDCD4在细胞中的表达变化。结果:与5.5mM葡萄糖对照组相比,高葡萄糖浓度组(11、22及33mM)中HUVECs的miRNA-21随着葡萄糖浓度的增加表达明显降低(p<0.01);PDCD4的蛋白表达增加(p<0.05),但PDCD4的mRNA表达无差异(p>0.05)。与0nM胰岛素组相比,10、50、100、1000nM胰岛素组细胞中miRNA-21表达下降(p<0.05),PDCD4的蛋白表达增加(p<0.01),1000nM组miRNA-21表达降低程度和PDCD4的蛋白表达增加程度最为明显(p<0.05),但不同浓度胰岛素对PDCD4的mRNA表达无差异(p>0.05...     

Choline Uptake by Cerebral Capillary Endothelial Cells in Culture

A passage of choline from blood to brain and vice versa has been demonstrated in vivo. Because of the presence of the blood-brain barrier, such passage takes place necessarily through endothelial cells. To get a better understanding of this phenomenon, the choline transport properties of cerebral capillary endothelial cells have been studied in vitro. Bovine endothelial cells in culture were able to incorporate [3H]choline by a carrier-mediated mechanism. Nonlinear regression analysis of the uptake curves suggested the presence of two transport components in cells preincubated in the absence of choline. One component showed a Km of 7.59 +/- 0.8 microM and a maximum capacity of 142.7 +/- 9.4 pmol/2 min/mg of protein, and the other one was not saturable within the concentration range used (1-100 microM). When cells were preincubated in the presence of choline, a single saturable component was observed with a Km of 18.5 +/- 0.6 microM and a maximum capacity of 452.4 +/- 42 pmol/2 min/mg of protein. [3H]Choline uptake by endothelial cells was temperature dependent and was inhibited by the choline analogs hemicholinium-3, deanol, and AF64A. The presence of ouabain or 2,4-dinitrophenol did not affect the [3H]choline transport capacity of endothelial cells. Replacement of sodium by lithium and cell depolarization by potassium partially inhibited choline uptake. When cells had been preincubated without choline, recently transported [3H]choline was readily phosphorylated and incorporated into cytidine-5'-diphosphocholine and phospholipids; however, under steady-state conditions most (63%) accumulated [3H]choline was not metabolized within 1 h.(ABSTRACT TRUNCATED AT 250 WORDS)     

The Role of TLR2 and 4-Mediated Inflammatory Pathways in Endothelial Cells Exposed to High Glucose

Postprandial hyperglycemia induces inflammation and endothelial dysfunction resulting in vascular complications in patients with diabetes. Toll-like receptors (TLRs) are central to the regulation of inflammatory responses through activation of nuclear factor-kappa B (NF-ĸB). This study examined the role of TLR2 and 4 in regulating inflammation and endothelial dysfunction when exposed to fluctuating glucose concentrations. HMEC-1 cells (a human microvascular endothelial cell line) were exposed to control (5 mM), 30 mM (high), fluctuating (5/30 mM) and 11.2 mM glucose (approximate glycaemic criteria for the diagnosis of diabetes mellitus) for 72 h. Cells were assessed for TLR2, 4, high mobility group box -1 (HMGB1), NF-ĸB, monocyte chemoattractant protein-1 (MCP-1), interleukin-8 (IL-8), intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). Fluctuating glucose concentrations maximally upregulated TLR4 but not TLR2 expression with increased NF-ĸB activation, IL-8 and ICAM-1 expression. HMGB1 was increased in the supernatants of cells exposed to 30 mM and 11.2 mM glucose compared to control. The addition of recombinant HMGB1 induced NF-ĸB activation and synthesis of proinflammatory cytokines and chemokines, which were prevented by TLR2 or 4 signalling inhibition. An additive effect when both TLR2 and 4 signalling pathways were inhibited was observed. However, only inhibition of TLR4 signalling suppressed the synthesis of MCP-1, IL-8 and ICAM-1. In vivo, streptozotocin-induced diabetic mice exhibited an increase in glomerular ICAM-1 which was not evident in TLR2^-/- or TLR4^-/- diabetic mice. Collectively, our results suggest that targeting the signalling pathway of TLR2 and 4 may be of therapeutic benefit in attenuating vascular inflammation in diabetic microangiopathy.     

波动性高胰岛素对血管内皮细胞的凋亡的影响

目的:对比研究波动性高浓度胰岛素与恒定性高浓度胰岛素对体外培养的人脐静脉内皮细胞的凋亡的影响,从而探究波动性高浓度胰岛素血症在糖尿病动脉粥样硬化形成中的致病机制.方法:采用体外培养的人脐静脉内皮细胞为对象,研究波动性高胰岛素对血管内皮细胞的凋亡的影响.实验分为4组,即对照组(不含胰岛素)、正常浓度胰岛素组(含胰岛素1 nmol/L)、恒定性高胰岛素组(含胰岛素100nmol/L)与波动性高胰岛素组(含胰岛素1 nmol/L及含胰岛素100 nmol/L两种条件培养液,每8小时轮换一次),每间隔8小时更换新鲜条件培养液一次,一共作用72小时.应用AO-EB染色法与流式细胞仪检测内皮细胞凋亡.结果:1、胰岛素对内皮细胞凋亡的影响1.1经不同浓度的胰岛素作用72小时后,AO-EB检测结果显示:正常浓度胰岛素组的内皮细胞凋亡细胞数明显下降,为对照组的81%(p<0.001),而恒定性高胰岛素组与波动性高胰岛素组的内皮细胞凋亡细胞数明显上升,分别为对照组的1.53倍(p<0.001)与1.75倍(p<0.001),正常浓度胰岛素组的1.88倍(p<0.001)与2.15倍(p<0.001);且波动性高胰岛素组内皮细胞凋亡细胞数显著高于恒定性高胰岛素组(p<0.001).1.2经不同浓度的胰岛素作用72小时后,流式细胞仪检测结果显示:正常浓度胰岛素组的内皮细胞凋亡率明显下降,为对照组的81%(p<0.001),而恒定性高胰岛素组与波动性高胰岛素组的内皮细胞凋亡率出现明显上升,分别为对照组的1.11倍(p<0.01)与1.39倍(p<0.001),正常浓度胰岛素组的1.37倍(p<0.001)与1.72倍(p<0.001);且波动性高胰岛素组内皮细胞凋亡率显著高于恒定性高胰岛素组(p<0.001).结论:1、波动性高胰岛素相对于恒定性高胰岛素更能诱导人脐静脉内皮细胞的凋亡.     

Caveolae-Dependent and -Independent Uptake of Albumin in Cultured Rodent Pulmonary Endothelial Cells

Although a critical role for caveolae-mediated albumin transcytosis in pulmonary endothelium is well established, considerably less is known about caveolae-independent pathways. In this current study, we confirmed that cultured rat pulmonary microvascular (RPMEC) and pulmonary artery (RPAEC) endothelium endocytosed Alexa488-labeled albumin in a saturable, temperature-sensitive mode and internalization resulted in co-localization by fluorescence microscopy with cholera B toxin and caveolin-1. Although siRNA to caveolin-1 (cav-1) in RPAEC significantly inhibited albumin uptake, a remnant portion of albumin uptake was cav-1-independent, suggesting alternative pathways for albumin uptake. Thus, we isolated and cultured mouse lung endothelial cells (MLEC) from wild type and cav-1^-/- mice and noted that ~ 65% of albumin uptake, as determined by confocal imaging or live cell total internal reflectance fluorescence microscopy (TIRF), persisted in total absence of cav-1. Uptake of colloidal gold labeled albumin was evaluated by electron microscopy and demonstrated that albumin uptake in MLEC from cav-1^-/- mice was through caveolae-independent pathway(s) including clathrin-coated pits that resulted in endosomal accumulation of albumin. Finally, we noted that albumin uptake in RPMEC was in part sensitive to pharmacological agents (amiloride [sodium transport inhibitor], Gö6976 [protein kinase C inhibitor], and cytochalasin D [inhibitor of actin polymerization]) consistent with a macropinocytosis-like process. The amiloride sensitivity accounting for macropinocytosis also exists in albumin uptake by both wild type and cav-1^-/- MLEC. We conclude from these studies that in addition to the well described caveolar-dependent pulmonary endothelial cell endocytosis of albumin, a portion of overall uptake in pulmonary endothelial cells is cav-1 insensitive and appears to involve clathrin-mediated endocytosis and macropinocytosis-like process.     

外源咖啡酸和阿魏酸对黑莓汁中花色苷的辅色研究

为增强黑莓汁中花色苷的稳定,添加适量咖啡酸和阿魏酸到黑莓清汁中,采用可见吸收光谱和高效液相色谱-质谱研究其对黑莓花色苷的辅色作用。研究结果表明:黑莓汁中添加咖啡酸和阿魏酸显著增加了花色苷的最大吸收值(Aλmax),最大吸收波长(λmax)红移,说明咖啡酸和阿魏酸对黑莓汁中花色苷产生了辅色作用,辅色效应随时间的延长和咖啡酸、阿魏酸浓度的增加显著增强。HPLC-DAD-MS分析发现,咖啡酸辅色产生了两种新的花色苷衍生物(矢车菊素-3-O-葡萄糖苷-4-乙烯基儿茶酚和矢车菊-3-O-草酸酐酰葡萄糖苷-4-乙烯基儿茶酚),阿魏酸辅色产生了三种新的花色苷衍生物(矢车菊素-3-O-葡萄糖苷-4-乙烯基愈创木酚、矢车菊-3-O-草酸酐酰葡萄糖苷-4-乙烯基愈创木酚和矢车菊-3-O-阿拉伯糖苷-4-乙烯基愈创木酚),这些衍生物均为羟苯基-吡喃花色苷。     

Caffeic Acid Phenylethyl Ester and MG-132 Have Apoptotic and Antiproliferative Effects on Leukemic Cells But Not on Normal Mononuclear Cells

Chemotherapy aims to limit proliferation and induce apoptotic cell death in tumor cells. Owing to blockade of signaling pathways involved in cell survival and proliferation, nuclear factor κB (NF-κB) inhibitors can induce apoptosis in a number of hematological malignancies. The efficacy of conventional chemotherapeutic drugs, such as vincristine (VCR) and doxorubicine (DOX), may be enhanced with combined therapy based on NF-κB modulation. In this study, we evaluated the effect of caffeic acid phenylethyl ester (CAPE) and MG-132, two nonspecific NF-κB inhibitors, and conventional chemotherapeutics drugs DOX and VCR on cell proliferation and apoptosis induction on a lymphoblastoid B-cell line, PL104, established and characterized in our laboratory. CAPE and MG-132 treatment showed a strong antiproliferative effect accompanied by clear cell cycle deregulation and apoptosis induction. Doxorubicine and VCR showed antiproliferative effects similar to those of CAPE and MG-132, although the latter drugs showed an apoptotic rate two-fold higher than DOX and VCR. None of the four compounds showed cytotoxic effect on peripheral mononuclear cells from healthy volunteers. CAPE- and MG-132-treated bone marrow cells from patients with myeloid and lymphoid leukemias showed 69% (P < .001) and 25% decrease (P < .01) in cell proliferation and 42% and 34% (P < .01) apoptosis induction, respectively. Overall, our results indicate that CAPE and MG-132 had a strong and selective apoptotic effect on tumor cells that may be useful in future treatment of hematological neoplasias.     

Endocytotic Uptake of Zoledronic Acid by Tubular Cells May Explain Its Renal Effects in Cancer Patients Receiving High Doses of the Compound

Zoledronic acid, a highly potent nitrogen-containing bisphosphonate used for the treatment of pathological bone loss, is excreted unmetabolized via the kidney if not bound to the bone. In cancer patients receiving high doses of the compound renal excretion may be associated with acute tubular necrosis. The question of how zoledronic acid is internalized by renal tubular cells has not been answered until now. In the current work, using a primary human tubular cell culture system, the pathway of cellular uptake of zoledronic acid (fluorescently/radiolabeled) and its cytotoxicity were investigated. Previous studies in our laboratory have shown that this primary cell culture model consistently mimics the physiological characteristics of molecular uptake/transport of the epithelium in vivo. Zoledronic acid was found to be taken up by tubular cells via fluid-phase-endocytosis (from apical and basolateral side) as evidenced by its co-localization with dextran. Cellular uptake and the resulting intracellular level was twice as high from the apical side compared to the basolateral side. Furthermore, the intracellular zoledronic acid level was found to be dependent on the administered concentration and not saturable. Cytotoxic effects however, were only seen at higher administration doses and/or after longer incubation times. Although zoledronic acid is taken up by tubular cells, no net tubular transport could be measured. It is concluded that fluid-phase-endocytosis of zoledronic acid and cellular accumulation at high doses may be responsible for the acute tubular necrosis observed in some cancer patients receiving high doses of the compound.     

脑微血管内皮细胞氧糖剥夺条件培养液对PC12细胞活性的影响

目的:观察脑微血管内皮细胞氧糖剥夺后条件培养液对PC12细胞的影响.方法:原代培养大鼠脑皮质微血管内皮细胞,传至三代.制备其正常、氧糖剥夺、复糖复氧三种状态条件液,并观察内皮细胞在这三种状态下的形态改变;将这三种条件培养液作用于PC12细胞,分4组:正常对照组(Normal)、正常内皮细胞条件液组(N-CM)、氧糖剥夺内皮细胞条件液组(I-CM)、复糖复氧内皮细胞条件液组(R-CM).每组分别设6h、12 h、24 h、48 h、72 h、96 h、120 h、144 h 8个时间点,MTS/PMS法检测三种脑微血管内皮细胞条件液作用后的不同时间点PC12细胞活性的变化.结果:氧糖剥夺后脑微血管内皮细胞发生核固缩等明显病理改变,复糖复氧后这些改变有所恢复.N-CM组、R-CM组与相应时间点的Normal组PC12细胞活性相比差异均有统计学意义(P＜0.01).正常和复糖复氧内皮细胞条件液显著抑制了PC12细胞的增殖和活性.N-CM组、R-CM组与相应时间点的I-CM组PC12细胞活性相比差异均有统计学意义(P＜0.01).结论:正常脑微血管内皮细胞条件液抑制了PC12细胞的活性,氧糖剥夺后的脑微血管内皮细胞务件液抑制效应消失,复糖复氧后,这种抑制效应也同时恢复.     

In vitro Effects of Plasma Acid on Proliferation of Rat Brain Endothelial Cells

Journal of Evolutionary Biochemistry and Physiology - The proliferative activity of brain microvascular endothelial cells is regulated by a wide range of factors: regulatory molecules, toxic...     

High Glucose Induced Alteration of SIRTs in Endothelial Cells Causes Rapid Aging in a p300 and FOXO Regulated Pathway

In diabetes, some of the cellular changes are similar to aging. We hypothesized that hyperglycemia accelerates aging-like changes in the endothelial cells (ECs) and tissues leading to structural and functional damage. We investigated glucose-induced aging in 3 types of ECs using senescence associated β-gal (SA β-gal) staining and cell morphology. Alterations of sirtuins (SIRTs) and their downstream mediator FOXO and oxidative stress were investigated. Relationship of such alteration with histone acetylase (HAT) p300 was examined. Similar examinations were performed in tissues of diabetic animals. ECs in high glucose (HG) showed evidence of early senescence as demonstrated by increased SA β-gal positivity and reduced replicative capacities. These alterations were pronounced in microvascular ECs. They developed an irregular and hypertrophic phenotype. Such changes were associated with decreased SIRT (1–7) mRNA expressions. We also found that p300 and SIRT1 regulate each other in such process, as silencing one led to increase of the others’ expression. Furthermore, HG caused reduction in FOXO1’s DNA binding ability and antioxidant target gene expressions. Chemically induced increased SIRT1 activity and p300 knockdown corrected these abnormalities slowing aging-like changes. Diabetic animals showed increased cellular senescence in renal glomerulus and retinal blood vessels along with reduced SIRT1 mRNA expressions in these tissues. Data from this study demonstrated that hyperglycemia accelerates aging-like process in the vascular ECs and such process is mediated via downregulation of SIRT1, causing reduction of mitochondrial antioxidant enzyme in a p300 and FOXO1 mediated pathway.     

木犀草素对高糖诱导的心肌微血管内皮细胞损伤的影响及机制

目的:探讨木犀草素对高糖诱导的心肌微血管内皮细胞(cardiac microvascular endothelial cells,CMECs)损伤的影响及其可能调控机制。方法:消化法分离大鼠CMECs,将原代CMECs随机分为4组:低糖组、低糖+木犀草素组、高糖组和高糖+木犀草素组。低糖+木犀草素组和高糖+木犀草素组分别加入30μmmol/L的木犀草素孵育24 h,低糖组和高糖组分别加入同等体积的DMSO孵育24 h。CCK-8实验检测CMECs增殖;Tunel法检测CMECs凋亡;Transwell检测CMECs的迁移能力;Western blot检测PKC-βⅡ的表达。结果:与低糖组和低糖+木犀草素组相比,高糖组CMECs增殖能力显著降低(0.341±0.018,P0.05),CMECs凋亡显著增加(P0.05),CMECs迁移能力显著降低(116±12.2,P0.05),PKC-βⅡ的表达显著增加(P0.05);与高糖组相比,高糖+木犀草素组CMECs增殖能力显著增加(0.550±0.023,P0.05),CMECs凋亡显著减少(P0.05),CMECs迁移能力显著增加(169±7.3,P0.05),PKC-βⅡ的表达显著降低(P0.05)。结论:木犀草素可能通过抑制PKC-βⅡ激活减少高糖诱导的心肌微血管内皮细胞损伤。