ApoE Production in Human Monocytes and Its Regulation by Inflammatory Cytokines

The apoE production by tissue macrophages is crucial for the prevention of atherosclerosis and the aim of this study was to further elucidate how this apolipoprotein is regulated by cytokines present during inflammation. Here we studied apoE production in peripheral blood mononuclear cells (PBMC) and analysis was made with a newly developed apoE ELISpot assay. In PBMC, apoE secretion was restricted to monocytes with classical (CD14⁺⁺CD16⁻) and intermediate (CD14⁺CD16⁺) monocytes being the main producers. As earlier described for macrophages, production was strongly upregulated by TGF-β and downregulated by bacterial lipopolysaccharide (LPS) and the inflammatory cytokines IFN-γ, TNF-α and IL-1β. We could here show that a similar down-regulatory effect was also observed with the type I interferon, IFN-α, while IL-6, often regarded as one of the more prominent inflammatory cytokines, did not affect TGF-β-induced apoE production. The TNF-α inhibitor Enbrel could partly block the down-regulatory effect of IFN-γ, IFN-α and IL-1β, indicating that inhibition of apoE by these cytokines may be dependent on or synergize with TNF-α. Other cytokines tested, IL-2, IL-4, IL-12, IL-13, IL-17A and IL-23, had no inhibitory effect on apoE production. In contrast to the effect on monocytes, apoE production by primary hepatocytes and the hepatoma cell line HepG2 was more or less unaffected by treatment with cytokines or LPS.     

基质金属蛋白酶与血管壁细胞外基质重建

细胞外基质（ECM）不仅维持血管壁的完整性,而且还为血管细胞传递增殖,迁移,分化和凋亡的调控信号,基质金属蛋白酶（MMP）及其内源性抑制剂（TIMP）通过调节ECM合成与降解之间的动态平衡,使ECM维持正常的结构与功能。在高血压,动脉粥样硬化与血管再狭窄的发生与发展过程中,MMP和TIMP的合成与分泌出现异常,由此所引起的ECM合成与降解失调使ECM迅速发生重建。     

基质金属蛋白酶-9 与全身炎症反应综合征研究进展

全身炎症反应综合征是引发多器官功能障碍综合征的主要原因,而其发生的关键环节是血管内皮细胞的损伤。内皮细胞外基质是内皮细胞生存的依托,其主要成分为IV型胶原。基质金属蛋白酶-9可以降解IV型胶原,破坏内皮细胞外基膜。本文综述了基质金属蛋白酶-9与全身炎症反应的关系。     

Expression of Human Membrane Type 1 Matrix Metalloproteinase in Pichia pastoris

A soluble, C-terminal truncated form of human membrane type 1 matrix metalloproteinase (MT1-MMP) containing the hemopexin-like domain was expressed in Pichia pastoris strain KM71. High levels of secreted protein were detected. Although the c-DNA for the proenzyme (Ala²¹-Glu⁵²³ called ΔTM-MT1-MMP) was cloned, almost only active MT1-MMP (Tyr¹¹²-Glu⁵²³) with identical N-terminus as described for the wild-type enzyme was isolated. This active enzyme was highly purified and characterized with respect to its biochemical properties. The recombinant protein showed high stability against autolysis and proteolysis by yeast proteases, although the calculated in vivo half-life is rather low. The biochemical properties of this new MT1-MMP species were compared with the well-characterized catalytic domain (Ile¹¹⁴-Ile³¹⁸) of MT1-MMP. The novel form of MT1-MMP exhibited a higher stability against autolysis than the isolated catalytic domain (Ile¹¹⁴-Ile³¹⁸).     

Inhibitory Effects of Alcohols on the Activity of Human Matrix Metalloproteinase 7 (Matrilysin)

Aliphatic alcohols inhibited the activity of human matrix metalloproteinase 7 (matrilysin) competitively with K_i of 6.1–19.4% (v/v) or 0.66–4.80 M. From the relationship between the structures of alcohols and their K_i values, alcohols are considered to bind the hydrophobic S1′ subsite most plausibly, and the size of the pocket was estimated to be large enough to accommodate the length of 1-butanol (4-carbon chain) and the bulk of tertiary alcohols. Alcohols might be suitable probes for exploring the active-site geometry of enzymes.     

Puerarin Attenuated Early Diabetic Kidney Injury through Down-Regulation of Matrix Metalloproteinase 9 in Streptozotocin-Induced Diabetic Rats

Radix puerariae, a traditional Chinese herbal medication, has been used successfully to treat patients with early stage of diabetic nephropathy. However, the underlined mechanism of this renal protective effect has not been determined. In the current study, we investigated the effects and the mechanism of puerarin in Streptozotocin (STZ)-induced diabetic rats. We treated STZ-rats with either puerarin or losartan, an angiotensin II receptor blocker, as compared to those treated with vehicle. We found that both puerarin and losartan attenuated kidney hypertrophy, mesangial expansion, proteinuria, and podocyte foot process effacement in STZ rats. In addition, both puerarin and losartan increased expression of podocyte slit diaphragm proteins such as nephrin and podocin. Interestingly, we found that puerarin treatment induced a more pronounced suppression of oxidative stress production and S-nitrosylation of proteins in the diabetic kidneys as compared to losartan treatment. Furthermore, we found that matrix metalloproteinase-9 (MMP-9), which is known to be activated by oxidative stress and S-nitrosylation of proteins, was also suppressed more extensively by puerarin than losartan. In conclusion, these data provide for the first time the potential mechanism to support the use of puerarin in the treatment of early diabetic nephropathy.     

Contribution of the Plasmin/Matrix Metalloproteinase Cascade to the Retraction of Human Fibroblast Populated Collagen Lattices

To assess the contribution of the plasmin/matrix metalloproteinase cascade in lattices retraction, human gingival fibroblast-populated collagen lattices were supplemented with plasminogen. The rate of lattice retraction was enhanced by addition of plasminogen. This effect was concomitant to plasmin generation, prostromelysin-1 and procollagenase activation. Plasminogen-mediated initiation of that proteolytic cascade was accompanied by conspicuous changes in cell morphology and collagen fibers organization. At day 1 of culture fibroblasts shifted from a rounded (control) to an elongated (in presence of plgn) shape. At the latest stage of retraction, intense vacuolization around fibroblasts was noticed in plgn-supplemented lattices which paralleled the increased collagen degradation. Plgn-enhancing influence on the initial phase of lattice retraction could be totally annihilated by either aprotinin or Batimastat. Those data emphasize the crucial importance of the plasmin–MMP proteolytic cascade in granulation tissue retraction in a healing wound.     

Increased Expression of Intranuclear Matrix Metalloproteinase 9 in Atrophic Renal Tubules Is Associated with Renal Fibrosis

Background

Reduced turnover of extracellular matrix has a role in renal fibrosis. Matrix metalloproteinases (MMPs) is associated with many glomerular diseases, but the histological association of MMPs and human renal fibrosis is unclear.

Methods

This is a retrospective study. Institutional Review Board approval was obtained for the review of patients’ medical records, data analysis and pathological specimens staining with waiver of informed consents. Specimens of forty-six patients were examined by immunohistochemical stain of MMP-9 in nephrectomized kidneys, and the association of renal expression of MMP-9 and renal fibrosis was determined. MMP-9 expression in individual renal components and fibrosis was graded as high or low based on MMP-9 staining and fibrotic scores.

Results

Patients with high interstitial fibrosis scores (IFS) and glomerular fibrosis scores (GFS) had significantly higher serum creatinine, lower estimated glomerular filtration rate (eGFR), and were more likely to have chronic kidney disease (CKD) and urothelial cell carcinoma. Univariate analysis showed that IFS and GFS were negatively associated with normal and atrophic tubular cytoplasmic MMP-9 expression and IFS was positively correlated with atrophic tubular nuclear MMP-9 expression. Multivariate stepwise regression indicated that MMP-9 expression in atrophic tubular nuclei (r = 0.4, p = 0.002) was an independent predictor of IFS, and that MMP-9 expression in normal tubular cytoplasm (r = −0.465, p<0.001) was an independent predictor of GFS.

Conclusions

Interstitial fibrosis correlated with MMP-9 expression in the atrophic tubular nuclei. Our results indicate that renal fibrosis is associated with a decline of MMP-9 expression in the cytoplasm of normal tubular cells and increased expression of MMP-9 in the nuclei of tubular atrophic renal tubules.     

银丹心脑通抑制泡沫细胞形成及巨噬细胞分泌基质金属蛋白酶

目的:银丹心脑临床治疗冠心病心绞痛疗效显著,但其机理尚不明确.本实验通过观察银丹心脑通对巨噬细胞分泌基质金属蛋白酶的作用,探讨银丹心脑通的作用机理.方法:生长状态良好的单核细胞分化成巨噬细胞,加入不同浓度的药物.24h后收集细胞上清,ELISA检测细胞上清中MMP-2、MMP-9的含量.结果:给药组不同剂量均能抑制MMP-2、MMP-9的表达(P＜0.01-0.05),其中高剂量组效果最为显著.结论:银丹心脑通能够抑制巨噬细胞基质金属蛋白酶的分泌,具有明显的抗炎作用,此实验为其在临床上的进一步应用提供了依据.     

Notch通路与基质金属蛋白酶在软骨肉瘤中的表达及意义

目的 研究软骨肉瘤组织中Notch通路、p38丝裂原活化蛋白激酶(MAPK)及基质金属蛋白酶(MMPs)的表达情况,探讨它们在软骨肉瘤间质浸润中的作用机制.方法 收集正常软骨组织标本10例、内生性软骨瘤标本23例和软骨肉瘤标本32例,分别用免疫组化、Western blot和real-time PCR检测Notch1、Jagged1、MMP-1、MMP-13、p38 MAPK及p-p38 MAPK的表达情况.结果 与正常软骨组织相比,Notch1、Jagged1、MMP-1、MMP-13及p-p38 MAPK在内生性软骨瘤表达部分升高,在软骨肉瘤表达均明显增加(P＜0.01).p38 MAPK在正常软骨组织、内生性软骨瘤及软骨肉瘤组织中表达无明显差异(P＞0.05).结论 Notch通路和p38 MAPK通过调节基质金属蛋白酶在软骨肉瘤中的表达,来增加软骨肉瘤的浸润转移能力.     

Increased Production of Endogenous Pyrogen and Lysozyme by Blood Monocytes in Sarcoidosis

Blood monocytes from patients with sarcoidosis were incubated in vitro, and secretion of endogenous pyrogen (EP), the protein which mediates fever, and lysozyme (L) were measured. After incubation with endotoxin, monocytes from 5 patients with sarcoidosis released twice as much EP as did monocytes from normal individuals (p < .001). Initial 24-hr secretion of L by monocytes from 6 of 11 additional patients with sarcoidosis exceeded the normal range of values for cells from 11 age- and sex-matched control individuals. Cells with initially augmented secretion rates continued to secrete increased amounts of L for 3 days. A correlation was noted between in vitro secretion of L by monocytes and serum levels of L in the same patient. These studies indicate that circulating mononuclear cells in some patients with sarcoidosis have an increased capacity to secrete EP and/or L prior to tissue localization.     

人基质金属蛋白酶-9在酵母Pichia pastoris中的表达

基质金属蛋白酶 - 9( MMP- 9)可促进恶性肿瘤的侵袭、转移 ,并在组织重建、胚胎发育以及伤口愈合等生理过程中发挥重要作用 .为研究这一蛋白的性质 ,并以之为靶标筛选抗肿瘤转移药物 ,在酵母 Pichia pastoris中实现了重组人 MMP- 9蛋白的高效、高活性、分泌表达 .首先用 PCR扩增了 MMP- 9基因编码区 (不含信号肽序列 ) ,经测序证实后 ,将其插入 p PIC9质粒中 ,构建表达载体 .用 Li C1 - PEG法转化酵母后 ,采用明胶 -酶谱法筛选获得 5株高效分泌表达 MMP- 9的克隆 ,经PCR证实 MMP- 9基因整合在阳性克隆的染色体中 .重组蛋白分子量为 93k D,表达量为 1 0 mg/L.重组蛋白可水解明胶及 型胶原 ,并可经有机汞 APMA诱导发生自剪切 ,转换成 85k D的激活形式 ,表明重组蛋白具有与天然人 MMP- 9蛋白相似的底物水解活性和自剪切激活特性 .     

Chitosan Enriched Three-Dimensional Matrix Reduces Inflammatory and Catabolic Mediators Production by Human Chondrocytes

This in vitro study investigated the metabolism of human osteoarthritic (OA) chondrocytes encapsulated in a spherical matrix enriched of chitosan. Human OA chondrocytes were encapsulated and cultured for 28 days either in chitosan-alginate beads or in alginate beads. The beads were formed by slowly passing dropwise either the chitosan 0.6%–alginate 1.2% or the alginate 1.2% solution through a syringe into a 102 mM CaCl2 solution. Beads were analyzed histologically after 28 days. Interleukin (IL)-6 and -8, prostaglandin (PG) E₂, matrix metalloproteinases (MMPs), hyaluronan and aggrecan were quantified directly in the culture supernatant by specific ELISA and nitric oxide (NO) by using a colorimetric method based on the Griess reaction. Hematoxylin and eosin staining showed that chitosan was homogeneously distributed through the matrix and was in direct contact with chondrocytes. The production of IL-6, IL-8 and MMP-3 by chondrocytes significantly decreased in chitosan-alginate beads compared to alginate beads. PGE₂ and NO decreased also significantly but only during the first three days of culture. Hyaluronan and aggrecan production tended to increase in chitosan-alginate beads after 28 days of culture. Chitosan-alginate beads reduced the production of inflammatory and catabolic mediators by OA chondrocytes and tended to stimulate the synthesis of cartilage matrix components. These particular effects indicate that chitosan-alginate beads are an interesting scaffold for chondrocytes encapsulation before transplantation to repair cartilage defects.