高血压胰岛素抵抗对PIP、MMP-2及左室舒张功能的影响

目的探讨原发性高血压（EH）有、无胰岛素抵抗（IR）患者左室重构及舒张功能的变化。方法测定86例EH患者和45例体检健康者空腹血糖及胰岛素,并计算胰岛素敏感性指数（IAI）,以≤对照组IAI均值（-3．72±0．32）的低限（4．04）者46例作为IR组,非IR组40例。比较三组受试者心脏舒张功能指标：等容舒张时间（IVRT）、二尖瓣环舒张早期运动速度（Ea）／舒张晚期运动速度（Aa）比值;左室重构指标：血清前胶原羧基端肽（PIP）、金属蛋白酶-2（MMP-2）浓度。结果与对照组比较非IR组和IR组平均IVRT均明显延长、Ea／Aa比值均明显降低、血清PIP、MMP-2均显著升高（P〈0．05和P〈0．01）;且与非IR组比较IR组平均IVRT和血清PIP、MMP-2进一步显著延长和升高,Ea／Aa比值进一步显著降低（P〈0．05和P〈0．01）。结论伴有IR的高血压患者较非IR高血压患者左室心肌重构更重、左室舒张功能更差。     

Acrolein activates matrix metalloproteinases by increasing reactive oxygen species in macrophages

Acrolein is a ubiquitous component of environmental pollutants such as automobile exhaust, cigarette, wood, and coal smoke. It is also a natural constituent of several foods and is generated endogenously during inflammation or oxidation of unsaturated lipids. Because increased inflammation and episodic exposure to acrolein-rich pollutants such as traffic emissions or cigarette smoke have been linked to acute myocardial infarction, we examined the effects of acrolein on matrix metalloproteinases (MMPs), which destabilize atherosclerotic plaques. Our studies show that exposure to acrolein resulted in the secretion of MMP-9 from differentiated THP-1 macrophages. Acrolein-treatment of macrophages also led to an increase in reactive oxygen species (ROS), free intracellular calcium ([Ca²⁺]_i), and xanthine oxidase (XO) activity. ROS production was prevented by allopurinol, but not by rotenone or apocynin and by buffering changes in [Ca²⁺]_I with BAPTA-AM. The increase in MMP production was abolished by pre-treatment with the antioxidants Tiron and N-acetyl cysteine (NAC) or with the xanthine oxidase inhibitors allopurinol or oxypurinol. Finally, MMP activity was significantly stimulated in aortic sections from apoE-null mice containing advanced atherosclerotic lesions after exposure to acrolein ex vivo. These observations suggest that acrolein exposure results in MMP secretion from macrophages via a mechanism that involves an increase in [Ca²⁺]_I, leading to xanthine oxidase activation and an increase in ROS production. ROS-dependent activation of MMPs by acrolein could destabilize atherosclerotic lesions during brief episodes of inflammation or pollutant exposure.     

The Domain of Hypertrophic Chondrocytes in Growth Plates Growing at Different Rates

In this study, we tested the hypotheses that (a) both the domain volume (volume of the cell and the matrix it has formed) and matrix volume of juxtametaphyseal hypertrophic chondrocytes in the growth plate is tightly controlled, and that (b) the domain volume of juxtametaphyseal hypertrophic chondrocytes is a strong determinant of the rate of bone length growth. We analyzed the rate of bone length growth (oxytetracycline labeling techniques) and nine stereologic and kinetic parameters related to the juxtametaphyseal chondrocytic domain in the proximal and distal radial and tibial growth plates of 21- and 35-day-old rats. The domain volume increased with increasing growth rates, independent of the location of the growth plate and the age of the animal. Within age groups, the matrix volume per cell increased with increasing growth rates, but an identical growth plate had the same matrix volume per cell in 21- and 35-day-old rats. The most suitable regression model (R ²= 0.992) to describe the rate of bone length growth included the mean volume of juxtametaphyseal hypertrophic chondrocytes and the mean rate of cell loss/cell proliferation. This relationship was independent of the location of the growth plate and the age of the animal. The data suggest that the domain volume of juxtametaphyseal hypertrophic chondrocytes, as well as the matrix volume produced per cell, may be tightly regulated. In addition, the volume of juxtametaphyseal hypertrophic chondrocytes and the rate of cell loss/rate of cell proliferation may play the most important role in the determination of the rate of bone length growth. Received: 2 December 1996 / Accepted: 24 March 1997     

Matrix Vesicles Promote Mineralization in a Gelatin Gel

Extracellular matrix vesicles (MVs) are associated with initial calcification in a variety of tissues, but the mechanisms by which they promote mineralization are not certain. In this study, MVs isolated from fourth passage rat growth plate chondrocyte cultures were included within a gelatin gel into which calcium and phosphate ions diffused from opposite ends. In this gel, apatite formation occurs by 3.5 days in the absence of mineralization promoters, allowing measurement of the ability of different factors to ``nucleate' apatite before this time or to assess the effects of molecules which modulate the rate and extent of mineral deposition. Mineral ion accumulation and crystal type are assayed at 5 days. In this study, MV protein content in the central band of a 10% gelatin gel was varied by including 100 μl of a Tris-buffered solution containing 0–300 μg/ml MV protein. There was a concentration-dependent increase in mineral accretion. Whereas 10 μg MV protein in the gel did not significantly promote apatite formation as compared with vesicle-free gels, 20 and 30 μg MV protein in the gel did promote apatite deposition. Inclusion of 10 mM β-glycerophosphate in the gels, along with MVs, did not significantly increase apatite formation despite the demonstrable alkaline phosphatase activity of the MVs. In contrast, MVs at all concentrations significantly increased apatite accumulation when proteoglycan aggregates or ATP, inhibitors of apatite formation and proliferation, were included in the gel. Slight increases in calcium, but not phosphate accumulation, were also noted when an ionophore was included with the MVs to facilitate Ca ion transport into the vesicles. FT-IR analysis of the mineral formed in the vesicle-containing gels revealed the presence of a bone-like apatite. These data suggest that MVs facilitate mineralization by providing enzymes that modify inhibitory factors in the extracellular matrix, as well as by providing a protected environment in which mineral ions can accumulate. Received: 28 January 1996 / Accepted: 9 August 1996     

Suppression of experimental allergic encephalomyelitis in the Lewis rat by the matrix metalloproteinase inhibitor Ro31-9790

Matrix metalloproteinases (MMPs) are implicated in the tissue destruction associated with inflammatory demyelinating diseases such as multiple sclerosis. The effect of a hydroxamate inhibitor of MMPs, Ro31-9790, on inflammatory demyelination was assessed in two acute models of experimental allergic encephalomyelitis (EAE). Daily intraperitoneal injections of Ro31-9790 (50mgkg^–1), beginning either at the time of disease induction or from day 3 post induction, significantly reduced the clinical severity of adoptively transferred EAE. Administration of the inhibitor from the day of induction of active EAE prevented disease onset in 9/10 animals. However, in a repeat study, in which clinical disease was much more severe in the vehicle treated animals, the inhibitor was less effective. Clinical signs and CNS histopathology correlated well, with greater numbers of inflammatory lesions associated with increased disease severity. The present study confirms a role for the MMP cascade in inflammation in EAE.     

2型糖尿病并脑梗死患者血清MMP-2、TIMP-1水平变化

目的观察2型糖尿病并脑梗死患者血清基质金属蛋白酶-2（matrix metalloproteinase-2，MMP-2）及其抑制因子基质金属蛋白酶抑制因子-1（tissue inhibitors of matrix metalloproteinase-1，TIMP-1）的水平变化，探讨其在脑梗死发生发展过程中的作用和意义。方法用ELISA法检测48例2型糖尿病并脑梗死患者发病24h，以及35例2型糖尿病非脑梗死患者、29例非糖尿病脑梗死组、39例健康体检者血清MMP-2和TIMP-1的含量。结果2型糖尿病脑梗死患者血清MMP-2、TIMP-1水平显著高于2型糖尿病非脑梗死组、非糖尿病脑梗死组、对照组（P〈0．05）。2型糖尿病脑梗死发病24h的血清MMP-2水平与空腹血糖、糖化血红蛋白（HbAlc）正相关（r=0．296，r=0．339）；2型糖尿病脑梗死发病24h血清TIMP-1水平与空腹血糖呈正相关（r=0．293），与HbA1c呈正相关（r=0．391）。与神经功能缺损程度评分（脑卒中分值）、总胆固醇、甘油三脂均无明显相关性（P〉0．05）。结论2型糖尿病并脑梗死患者血清MMP-2和TIMP-1水平增高且与血糖水平呈正相关，MMP-2和TIMP-1在2型糖尿病脑梗死发病过程中起着重要的作用。     

不同TOAST分型脑梗死患者血清基质金属蛋白酶-2和基质金属蛋白酶-9水平的研究

目的 探讨血清基质金属蛋白酶(MMP)-2和MMP-9与脑梗死TOAST分型和预后的关系.方法 应用ELISA法检测60例脑梗死患者(CI组)和30例对照者(NC组)血清MMP-2和MMP-9水平,根据TOAST分型,CI组又分为心源性脑栓塞组(20例)、大动脉粥样硬化性脑梗死组(20例)和腔隙性脑梗死组(20例),比较各组血清MMP-2和MMP-9水平的变化.结果 CI组患者脑梗死后第1天血清MMP-2水平较NC组明显降低,差异有统计学意义(P＜0.01),血清MMP-9水平较NC组明显升高,差异有统计学意义(P＜0.01);心源性脑栓塞组和大动脉粥样硬化性脑梗死组患者脑梗死后第1天血清MMP-9水平明显高于腔隙性脑梗死组,差异均有统计学意义(P均<0.01);血清MMP-9水平与美国国立卫生院卒中量表(NIHSS)评分呈正相关,预后良好患者发病12 d内血清MMP-9水平明显低于预后不良患者,差异有统计学意义(P＜0.01).结论 脑梗死后血清MMP-9水平升高,升高幅度和变化规律在TOAST各亚型不尽相同,心源性脑栓塞患者和大动脉粥样硬化性脑梗死患者MMP-9水平高于腔隙性脑梗死患者;血清MMP-9水平可作为评价脑梗死病情的可靠指标;脑梗死后第1天的血清MMP-9水平是预后的独立预测因素.     

Expression of Interstitial Collagenase (Matrix Metalloproteinase-1) in Gastric Cancers

The expression of matrix metalloproteinase-1 (MMP-1) gene and the presence of MMP-1 protein in gastric cancer were examined by in situ hybridization and immunohistochemistry. Expression of the interstitial Collagenase (MMP-1) gene was detected within the stroma of the neoplastic glands, and infiltration of eosinopilic was observed to be associated with regions of MMP-1 gene expression. The degree of eosinophils infiltration correlated with the level of MMP-1 mRNA expression. Immunostaining showed localization of MMP-1 protein in the stromal cells, and additionally in the neoplastic glands. These findings indicate that the stromal cells may play an important role in the expression of MMP-1, and suggest a pathophysiological role for MMP-1 in the invasion and metastasis of gastric cancer.