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1.
Arrested follicular maturation is a characteristic feature of polycystic ovary syndrome (PCOS). Follicles mature in ovarian stroma composed of extracellular matrix (ECM). However, little is known of the expression of ECM genes in polycystic ovaries. The present study compares the expression levels of genes coding for collagens, matrix metalloproteinases (MMP), their inhibitors (TIMP) and cathepsins in polycystic ovaries using fertile and post-menopausal ovaries as controls. In northern analyses, the gene expression profiles of type I and III collagen of PCOS samples resembled those observed in normal follicular phase ovaries, while mRNA levels of proalpha1(IV) collagen and TIMP-3 mRNA were significantly lower in polycystic than control ovaries. During the normal menstrual cycle, an increase was observed in MMP-9 gene expression during the luteal phase. In post-menopausal ovaries, mRNA levels for type I, III and IV collagens and osteonectin were reduced, while the MMP, TIMP (excluding TIMP-3) and cathepsins did not reflect this metabolic down-regulation. Immunohistochemical staining for MMP-9 and TIMP-4 suggested differences between polycystic and normally functioning ovaries. These data demonstrate that normal ovarian functions are associated with changes in production and degradation of ECM. The alterations observed in the production and/or distribution of type IV collagen, TIMP-3 and TIMP-4 suggest involvement of basement membranes in the pathogenesis of PCOS.  相似文献   

2.
The lack of expression of certain components involved in celladhesion and migration is believed to contribute to endometrialdysfunction and implantation failure. The purpose of this studywas to investigate whether luteal phase endometrium in womenwith unexplained infertility differs, with respect to specificextracellular matrix (ECM) proteins, from endometrium of normalfertile women. A panel of monoclonal antibodies to collagentype IV, fibronectin and laminin was used to characterize thelocalization of ECM components in the different endometrialcompartments. Precisely timed endometrial biopsies obtainedat 4, 7, 10 and 13 days following the luteinizing hormone surgewere obtained from 22 normal fertile women (group 1) and 24women suffering from unexplained infertility (group 2). Paraffin-embeddedsections were labelled using the streptavidin-biotin alkalinephosphatase technique. In group 1, collagen type IV, fibronectinand laminin were absent from the luminal epithelium but presentin stromal cells and the basement membrane of glands and bloodvessels. In group 2, these components were absent from all endometrialregions using equivalent titres of antibody to those used ingroup 1. This suggests that the endometrium of women with unexplainedinfertility demonstrates defects in the distribution of certainECM glycoproteins. A possible consequence of this defect maybe implantation failure.  相似文献   

3.
4.
Cerebral palsy (CP) is a nonprogressive central nervous system lesion clinically characterized by impairment of voluntary movement related to spasticity, time of activation, and strength of scheletal muscle. Altered muscular control may act on tendon structure and influence extracellular matrix homeostasis, in particular, collagen. The effect of spasticity on collagen turnover in CP patients’ tendons has not been described previously. We studied collagen turnover related genes in the gracilis and semitendinosus tendons of diplegic (n = 6) and quadriplegic (n = 15) patients, compared to normal subjects (n = 7). In particular, using real time RT-PCR, we analyzed the mRNA levels of the major extracellular matrix (ECM) components collagen type I (COL-I, alpha 2 chain COL1A2), the matrix metalloproteinase-1 (MMP-1) and the tissue inhibitor of MMP (TIMP-1), the enzyme responsible for collagen maturation lysyl hydroxylase 2b (LH2b), of the matricellular protein involved ECM remodelling (secreted protein acidic and rich in cysteine, SPARC), and the transforming growth factor-β1 (TGF-β1), a multipotent cytokine involved in collagen turnover. Our results show that gene expression profiles are quite different in CP samples compared to normal ones. In fact, spasticity induces relevant modifications of tendons at the molecular level, which modify their phenotypes to respond to the higher mechanical loading and increased functional demands. Interestingly, hypertonic quadriplegic subjects displayed the highest mRNA levels of COL1A2, LH2b, TGF-β1, and SPARC, suggesting that their tendons undergo higher mechanical loading stimulation.  相似文献   

5.
BACKGROUND: For the implantation of endometrium in ectopic locations, remodelling of the extracellular matrix (ECM) is necessary. Many studies have shown an increased expression of various proteases in the ectopic endometrium of women with endometriosis. Few, however, have addressed possible changes in protease expression in the eutopic endometrium. METHODS AND RESULTS: Herein, we reveal an increased release of proteolytic activity by the eutopic endometrium of women with endometriosis compared with normal women (P < 0.01). Using zymography and western blotting, we identified matrix metalloproteinase (MMP)-2 and MMP-9 in the culture medium, and further found that MMP-9 secretion, as assessed by zymography and enzyme-linked immunosorbent assay (ELISA), was elevated in women with endometriosis compared with normal women (P < 0.05). No statistically significant difference in MMP-2 secretion between women with and without endometriosis was noted. However, a significant difference in the levels of the tissue inhibitor of metalloproteinases (TIMP)-1, a known MMP-9 inhibitor, was found (P < 0.05). CONCLUSION: The endometriosis-associated increase in proteolysis and imbalance between the secretion of MMP-9 and that of its natural inhibitor, TIMP-1, revealed in the culture medium of endometrial tissue may reflect in vivo the enhanced capacity of this tissue to break down the ECM in host tissues, thereby favouring its ectopic implantation and development.  相似文献   

6.
Decidualization in mice comprises a deep remodeling of extracellular matrix (ECM) components of the endometrium. In a previous biochemical study we showed that collagen types I and III are present in both pregnant and nonpregnant mouse endometrium, whereas collagen type V is expressed exclusively after the onset of decidualization. The distribution of collagen types in the pregnant mouse endometrium and possible changes of these molecular types in the different regions of the decidua is, however, not known. Using immunofluorescence and confocal microscopy we showed the presence of collagen types I, III, and V in the endometrial stroma of implantation and interimplantation sites from days 5 to 8 of pregnancy in the mouse. Collagen type III was chiefly expressed in the implantation sites and was the only collagen type to be present in the materno-fetal interface on the day of the embryo implantation. However, collagen type I was the predominant collagen in the interimplantation sites. Collagen type V was weakly expressed in the nondecidualized stroma during all periods but was expressed in larger amounts in the decidualized areas on day 7 of pregnancy, simultaneously with the accumulation of thick collagen fibrils in the same region. The highest immunofluorescence labeling for the three types of collagen was observed on day 7 when the antimesometrial decidual tissue achieved its greatest development. These data support previous studies that showed an intense ECM remodeling of the mouse endometrial stroma during the beginning of pregnancy. This outstanding remodeling may be important to stabilize placental anchorage.  相似文献   

7.
Decidualization in mice comprises a deep remodeling of extracellular matrix (ECM) components of the endometrium. In a previous biochemical study we showed that collagen types I and III are present in both pregnant and nonpregnant mouse endometrium, whereas collagen type V is expressed exclusively after the onset of decidualization. The distribution of collagen types in the pregnant mouse endometrium and possible changes of these molecular types in the different regions of the decidua is, however, not known. Using immunofluorescence and confocal microscopy we showed the presence of collagen types I, III, and V in the endometrial stroma of implantation and interimplantation sites from days 5 to 8 of pregnancy in the mouse. Collagen type III was chiefly expressed in the implantation sites and was the only collagen type to be present in the materno-fetal interface on the day of the embryo implantation. However, collagen type I was the predominant collagen in the interimplantation sites. Collagen type V was weakly expressed in the nondecidualized stroma during all periods but was expressed in larger amounts in the decidualized areas on day 7 of pregnancy, simultaneously with the accumulation of thick collagen fibrils in the same region. The highest immunofluorescence labeling for the three types of collagen was observed on day 7 when the antimesometrial decidual tissue achieved its greatest development. These data support previous studies that showed an intense ECM remodeling of the mouse endometrial stroma during the beginning of pregnancy. This outstanding remodeling may be important to stabilize placental anchorage.  相似文献   

8.
Aortic stenosis (AS) results in myocyte and extracellular matrix remodeling in the human left ventricle (LV). The myocardial renin-angiotensin system is activated and collagens I and III and fibronectin accumulate. We determined the yet unknown regulation of enzymes that control collagen turnover, i.e., LV matrix metalloproteinases (MMP) and their tissue inhibitors (TIMPs) in human AS. We compared LV samples from AS patients undergoing elective aortic valve replacement (n=19) with nonused donor hearts with normal LV function (controls, n=12). MMP-2, MMP-9, MT1-MMP, and extracellular matrix metalloproteinase inducer (EMMPRIN), TIMP-1, TIMP-2, TIMP-3, and TIMP-4 mRNA were quantitated by real-time RCR. MMP-1, MMP-2, MMP-3, TIMP-3, TIMP-4, and EMMPRIN protein were measured by immunoblotting and MMP-9 and TIMP-1 protein by ELISA. Gelatinolytic MMP-2 and MMP-9 activity was measured by zymography. MMP-2 was increased in AS at mRNA, protein, and activity levels (131%, 193%, and 138% of controls). MMP-3 protein (308%) and EMMPRIN mRNA and protein were also upregulated (171% and 200%). In contrast, MMP-1 (37%) and MMP-9 mRNA, protein, and activity (26%, 21%, and 52%) were downregulated. MMP-9 activity was inversely correlated with LV size. TIMP-1 mRNA and protein were decreased (55% and 73%). In contrast, TIMP-2 mRNA (358%), TIMP-3 mRNA and protein (145% and 249%) were increased. TIMP-4 mRNA was not altered, but TIMP-4 protein was upregulated to 350%. Changes were similar in AS patients with normal and impaired LV ejection fraction. The dysregulation of myocardial MMPs and TIMPs in human AS starts at an early disease stage when LV function is still normal. In spite of upregulation of some MMPs the balance between MMP and TIMP is shifted towards MMP inhibition in human AS and may contribute to collagen accumulation.  相似文献   

9.
Effects of progesterone receptor modulator CDB-2914 on the expression of the extracellular matrix (ECM) components were examined in cultured human uterine leiomyoma and myometrial cells. ECM metalloproteinase inducer (EMMPRIN), matrix metalloproteinases (MMPs), tissue inhibitors of MMP (TIMPs) and collagen levels were assessed by Western blot analysis, MMP activity assay and real-time RT-PCR. RNA interference (RNAi) of EMMPRIN was performed using small interfering mRNA. In cultured leiomyoma cells, CDB-2914 treatment at concentrations greater than or equal to 10(-8) M significantly increased EMMPRIN, MMP-1 and MMP-8 protein contents and MMP-1, MMP-2, MMP-3 and MMP-9 mRNA levels, and activity of MMP-1, MMP-2, MMP-3 and MMP-9 in the medium. TIMP-1 and TIMP-2 were significantly decreased at mRNA and protein levels by CDB-2914 treatment at concentrations > or =10(-7) M in these cells. CDB-2914 treatment decreased types I and III collagen protein contents. However, CDB-2914 treatment did not affect the ECM component expression in cultured myometrial cells. RNAi of EMMPRIN abrogated CDB-2914-mediated both induction of MMPs and reduction of TIMPs and collagens in cultured leiomyoma cells. These results suggest that CDB-2914 modulates the expression of EMMPRIN, MMPs, TIMPs and collagens in cultured leiomyoma cells without comparable effects on myometrial cells.  相似文献   

10.
It is widely assumed that, after ovulation, the human endometrium undergoes specific changes and becomes receptive to the implantation of embryo during the mid-secretory phase. When implantation does not take place, further changes occur which eventually result in the shedding of human endometrium. The present study was carried out to examine whether there are changes in the cytokine gene expression in human endometrium which are correlated with endometrial function in various phases of the menstrual cycle. The RNase protection assay was performed on carefully dated endometria from normal subjects to characterize the expression of cytokines which potentially contribute to endometrial function. These included: tumour necrosis factor (TNF), interleukin (IL)-1beta, IL-6, IL-8, leukaemia inhibitory factor (LIF), transforming growth factor beta1 (TGF-beta1), macrophage colony stimulating factor (MCSF or colony stimulating factor-1), and vascular endothelial growth factor (VEGF) mRNAs. A low level of expression of these cytokine mRNAs was found during the proliferative and early secretory phase. Expression of cytokine mRNA increased during the mid-secretory phase and rose to a peak in the late secretory phase. The level of cytokine mRNA expression during gestation was most akin to that observed during the mid-secretory phase. Individuals with habitual abortion presented with an abnormal expression of IL-1beta and IL-6 mRNA in endometrium, during the mid-secretory phase. Taken together, these findings are consistent with a progressive rise in the expression of cytokines in human endometrium during the secretory phase in natural cycles. Furthermore, the findings show that habitual abortion is associated with the abnormal expression of IL-1beta and IL-6 in the mid-secretory phase.  相似文献   

11.
Matrix metalloproteinases (MMP), tissue inhibitors of metalloproteinases (TIMP), and MMP-TIMP interactions may contribute to the highly programmed process of embryo implantation. The loss of the delicate MMP-TIMP balance may lead to abnormal implantation. The role of TIMP-4 in mouse implantation has not been reported. This study examined mRNA and protein expression levels of TIMP-4 in the blastocyst and uteri of pregnant mice. We also investigated the effects of a specific TIMP-4 antibody on embryo outgrowth and on the gene and protein expression levels of two gelatinases. High levels of TIMP-4 mRNA and protein were detected in day 3-5 embryos and in the trophoblast cells of mice blastocysts, suggesting that TIMP-4 may be involved in embryo implantation. Furthermore, TIMP-4 antibody promoted blastocyst outgrowth in a dose-dependent manner, but had no effect on blastocyst adhesion to extracellular matrix. A specific TIMP-4 antibody also increased mRNA and protein expression levels and the enzymatic activities of gelatinase A (MMP-2) and gelatinase B (MMP-9). This study suggests that TIMP-4 may restrict mouse blastocyst outgrowth and embryo implantation by inhibiting the activities of MMP-2 and -9.  相似文献   

12.
BACKGROUND: A recent clinical trial demonstrated that selective progesterone receptor modulator asoprisnil is effective in reducing uterine leiomyoma volume. We investigated the effects of asoprisnil in vitro on the expression of the extracellular matrix (ECM)-remodeling enzymes and collagens in cultured leiomyoma and matching normal myometrial cells. METHODS: The expression of extracellular matrix metalloproteinase inducer (EMMPRIN), matrix metalloproteinases (MMPs), tissue inhibitors of MMP (TIMPs) and collagens were assessed by western blot analysis. RESULTS: Untreated cultured leiomyoma cells had significantly lower EMMPRIN (P < 0.05), MMP-1 (P < 0.05) and membrane type 1-MMP (MT1-MMP) (P < 0.01) protein contents, but significantly higher TIMP-1 (P < 0.05), TIMP-2 (P < 0.01), type I (P < 0.05) and type III (P < 0.01) collagen protein contents compared with untreated cultured myometrial cells. Treatment with asoprisnil at concentrations > or =10(-7) M for 48 h significantly (P < 0.05) increased EMMPRIN, MMP-1 and MT1-MMP protein contents, and decreased TIMP-1 (P < 0.05), TIMP-2 (P < 0.01), type I (P < 0.01) and type III (P < 0.05 at 10(-7) M; P < 0.01 at 10(-6) M) collagen protein contents in cultured leiomyoma cells compared with control cultures. However, asoprisnil treatment did not affect the protein contents of ECM-remodeling enzymes and collagens in cultured myometrial cells. CONCLUSIONS: These results suggest that asoprisnil may reduce collagen deposit in the ECM of cultured leiomyoma cells through decreasing collagen synthesis and enhancing the expression of EMMPRIN, MMPs and TIMPs without comparable effects on cultured myometrial cells.  相似文献   

13.
Aims:  Keloid is characterized by excessive deposition of collagen, resulting from aberrant extracellular matrix (ECM) production and degradation. The aim was to investigate the role of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) in pathological wound healing in keloids.
Methods and results:  Semiquantitative analysis of 60 keloid tissue samples and 25 mature scar tissue samples demonstrated significantly increased expression of MMP-2, TIMP-2 and TIMP-3 in keloids compared with mature scars. Within keloid regions, MMP-2 expression was significantly higher in collagen bundle regions than in non-collagen bundle regions. Double immunofluorescence revealed that keloid fibroblasts between collagen bundles exhibited MMP-2, TIMP-2 and membrane-type 1 MMP (MT1-MMP) co-expression, whereas only MMP-2 expression was evident on the edge of collagen bundles. Western blot analysis and gelatin zymography of 13 keloid-derived fibroblasts (KFbs) and six normal skin dermal-derived fibroblasts (NFbs) demonstrated that unstimulated KFbs exhibited significantly increased MMP-2 activity and expression compared with NFbs under the same conditions.
Conclusions:  These results together indicate that MMP-2 activity can be promoted in keloid fibroblasts between collagen bundles in cooperation with TIMP-2 and MT1-MMP. This could contribute to remodelling of collagen bundle regions and invasion of fibroblasts into peripheral normal regions through promoted degradation of ECM.  相似文献   

14.
In order to study survivin, matrix metalloproteinases (MMP-2), membranous type 1 matrix metalloproteinase (MT1-MMP), and tissue inhibitor metalloproteinase-2 (TIMP-2) expression immunohistochemically in endometriotic tissues and normal endometrium, our retrospective study considered 194 patients affected by endometriosis and 71 patients with normal endometrium. Tissue microarrays were created from paraffin-embedded blocks; immunohistochemistry was used to assess protein expression. In endometriotic tissues, survivin was expressed at a higher level than in normal endometrium; its glandular expression level was higher in non-ovarian than in ovarian endometriotic tissues and lower in stromal components. Endometrial tissues from women without endometriosis and endometriotic tissues had different matrix metalloproteinase expression profiles. MMP-2 and MT1-MMP correlated with TIMP-2 in endometriotic tissues. Furthermore, in endometriotic tissues, expression of survivin, aurora B kinase, and Ki-67 showed a significant positive correlation, which indicates a role in cellular proliferation that could be closely linked to its anti-apoptotic activity in endometriosis development. Our results imply a role for matrix metalloproteinases in endometriosis invasiveness; correlation of their expression with that of TIMP-2 underscores its possible key regulatory role.  相似文献   

15.
In the present study, we found collagenolytic and gelatinolytic activity in the supernatants of hepatocyte cultures from rats with experimental CCl(4)-induced liver cirrhosis, in levels significantly higher than in comparable supernatants of hepatocyte cultures from normal rats. In addition, we clearly detected the messenger ribonucleic acids (mRNA) of four matrix metalloproteinases (MMP-2, MMP-3, MMP-10, and MMP-13) and of two tissue inhibitors of matrix metalloproteinases (TIMP-1 and TIMP-2) in hepatocytes from both normal and cirrhotic rats by RT-PCR and by in situ hybridization. Finally, we demonstrated MMP-2, MMP-3, and MMP-13 and TIMP-1 and TIMP-2 proteins in the same hepatocyte preparations by immunostaining. We conclude that rat hepatocytes produce the major enzymes and inhibitors involved in liver ECM modulation and therefore suggests that they might participate actively in the pathophysiology of liver cirrhosis in rats.  相似文献   

16.
AIM: To obtain insight into the effects of oestrogen on extracellular matrix (ECM) in the postmenopausal endometrium. METHODS: The distribution of the components of the ECM, including collagen types I, III, IV, and VI, and laminin, was investigated in the human postmenopausal endometrium by an indirect immunofluorescence method with specific monoclonal antibodies and a polyclonal antibody. Collagens were also extracted from the endometrial tissues of postmenopausal women who had or had not been treated with oestrogen for three weeks. RESULTS: Immunohistochemical studies demonstrated that type I collagen was the predominant interstitial collagen, and that types III and VI collagens were absent or very sparsely distributed in the stroma of the postmenopausal endometrium. However, types I, III, and VI collagens were diffusely localised in the stroma of the postmenopausal endometrium after administration of oestrogen. Even though type IV collagen was not seen in the basement membrane of the endometrial glands in the endometrium of postmenopausal women in the absence of oestrogen treatment, both type IV collagen and laminin were localised exclusively in the basement membrane of the endometrial glands in the postmenopausal endometrium after three weeks of oestrogen treatment. The level of type III collagen relative to that of type I collagen was significantly increased (p < 0.01) in the endometrium of oestrogen treated postmenopausal women compared with non-treated postmenopausal women. CONCLUSIONS: Conjugated equine oestrogen might induce changes in the distribution of components and in the composition of the ECM in the endometrium of postmenopausal women.  相似文献   

17.
18.
Tissue inhibitors of metalloproteinases (TIMP) in invasion and proliferation   总被引:14,自引:0,他引:14  
Tissue inhibitors of matrix metalloproteinases (TIMPs) are a family of natural inhibitors that control the activity of matrix metalloproteinases (MMPs) in the extracellular matrix (ECM). Four members of this family have been so far characterized in a variety of species. These inhibitors share a similar structural feature characterized by the presence of 12 cysteine residues involved in disulfide bonds and a similar function by their ability to form inhibitory complexes with MMPs. The role of TIMPs in cancer has been the subject of conflicting reports with an antitumor activity reported by some investigators and a growth stimulation activity reported by others. Here we will discuss a series of data obtained in our laboratory supporting a role of TIMPs not only as inhibitors of invasion but also as regulators of cell growth. Using placental development as an example of a regulated invasive process, we have observed that the levels of TIMP-2 and TIMP-3 steadily increase between day 14.5 and 17.5 post-coitus. TIMPs are selectively expressed by spongiotrophoblastic cells that separate the labyrinthine zone, rich in fetal blood vessels and maternal blood sinuses, from the zone of giant cells forming the border between fetal and maternal tissues. TIMPs are also potent inhibitors of tumor growth in vivo. In melanoma cells, we have previously reported that over-expression of TIMP-2 inhibits the growth of tumors implanted in the skin of scid mice. This growth inhibition seems independent of angiogenesis but dependent on the collagen matrix. We observed that in the presence of fibrillar type I collagen, melanoma cells undergo a growth arrest at the G1 to S interphase transition of the cell cycle. This arrest is specific to the fibrillar structure of collagen because it is not observed in the presence of non-fibrillar collagen or other ECM components. It is associated with a specific upregulation of the cyclin inhibitor p27KIP1. The data therefore indicate that anchorage independent cells remain sensitive to growth regulatory signals that originate from the ECM and that these signals can specifically block tumor cell cycle. Thus our concept of the role of protease inhibitors such as TIMPs in cancer has substantially changed from an initial focus on inhibition of tumor invasion and metastasis to a broader focus on being molecules that--via their function as regulators of the ECM homeostasis--can control tumor cell growth.  相似文献   

19.
目的 探讨基质金属蛋白酶2(MMP-2)及其抑制因子2(TIMP-2)在子宫腺肌病(AM)在位内膜与异位内膜的表达及意义.方法 选取广州医学院附属广州市第一人民医院2006年2月至2007年9月因AM行全子宫切除术的42例病例(取其在位及异位内膜分为AM在位内膜组和AM异位内膜组)和同期因子宫肌瘤在该院行全子宫切除术的32例病例(取其内膜作为正常子宫内膜组),应用半定量反转录聚合酶链反应(RT-PCR)检测AM在位内膜、异位内膜及正常子宫内膜中MMP-2、TIMP-2mRNA的表达.结果 (1)MMP-2 mRNA在AM异位内膜组中相对表达量(1.43±0.32)高于AM在位内膜组和正常子宫内膜组(1.22±0.35,0.97±0.37,P<0.05).TIMP-2 mRNA在AM异位内膜组和AM在位内膜组中均低表达,其相对表达量分别低于正常子宫内膜组(0.96±0.31,1.13±0.30,1.29±0.19,P<0.05).(2)MMP-2 mRNA、TIMP-2 mRNA在子宫腺肌病在位内膜组、正常子宫内膜组的表达有周期性,分泌期均高于增生期(P<0.05);而在AM异位内膜组中,两者分泌期与增生期则差异无统计学意义.(3)MMP-2/TIMP-2的比值在AM异位内膜组、AM在位内膜组、正常子宫内膜组中依次递减,其中AM异位内膜组与后两组差异有统计学意义(均P<0.05).结论 AM异位和在位内膜组织中MMP-2高表达,TIMP-2低表达,使MMP-2/TIMP-2平衡失调,异位内膜组织侵袭降解细胞外基质的能力增强.  相似文献   

20.
Immunohistochemical and confocal microscopic studies of the localization of matrix metalloproteinases (MMPs), their tissue inhibitors (TIMPs), and type IV collagen were made in lung tissues from patients with normal pulmonary histology (n = 3), diffuse alveolar damage (n = 14), and idiopathic pulmonary fibrosis (n = 12). Pretreatment with pepsin revealed otherwise undetectable MMP- and TIMP-immunoreactive sites. In normal lung, MMP-2, MMP-9, TIMP-1, and TIMP-2 were localized in ciliated cells, endothelial cells, pneumocytes, macrophages, and smooth muscle cells; fibroblasts showed a strong reaction only for MMP-2. Only TIMP-2 showed co-localization with type IV collagen. Myofibroblasts and epithelial cells expressed increased reactivity for MMPs and TIMPs in both disorders. The reactivities for MMPs and TIMPs were stronger in diffuse alveolar damage. MMP-2 showed focal co-localization in capillary endothelial and disrupted epithelial basement membranes, suggesting activation of collagenolysis. A protective effect against this lysis was suggested by the extensive co-localization of TIMP-2 with type IV collagen and fibrillar collagens. Alveolar buds showed increased reactivity for MMPs and TIMPs in their lining epithelial cells, myofibroblasts, and their basement membranes; however, their matrices were mostly unreactive. These findings emphasize the complexity of the roles of MMPs and TIMPs in collagen turnover in diffuse alvcolar damage and idiopathic pulmonary fibrosis.  相似文献   

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