To ascertain whether connective tissue growth factor (CTGF) participates in the remodeling of pulmonary artery at the early-stage of bleomycin (BLM)-induced pulmonary fibrosis, mean pulmonary arterial pressure, the expression of type I and type III collagens, and the expression and location of CTGF in pulmonary artery and arteriole were investigated in the present study. Sprague-Dawley rats received instillation of BLM [5 mg/kg body weight, in 0.5 mL of normal saline (NS)] or instillation of the same amount of NS as control. Mean pulmonary arterial pressure was detected via a catheter in the pulmonary artery. Type I and type III collagens were examined with Sirius red staining under polarized light. CTGF expression was investigated by using immunohistochemistry, and was represented as average optical density and percentage of positive area of CTGF. The mean pulmonary arterial pressure was higher in rats on day 14 after BLM instillation [(19.5+/-2.9) mmHg] than that in the control rats [(14.8+/-1.2) mmHg] (P<0.05). The type I and type III collagens were increased both in pulmonary artery and arteriole of rats on day 14 after BLM instillation, compared with those in the control rats (P<0.05, P<0.01, respectively). The ratio of type I/III collagens in pulmonary artery was also higher in BLM-treated rats than that in the control rats (P<0.05). The values of average optical density of positive CTGF staining were increased both in pulmonary artery (0.37+/-0.02) and arteriole (0.40+/-0.03) of rats on day 14 after BLM instillation, compared with those in the control rats (artery, 0.34+/-0.01; arteriole, 0.29+/-0.01) (both P<0.05). The percentages of positive area of CTGF were higher in pulmonary artery (8.40+/-1.13) and arteriole (12.4+/-2.0) of rats on day 14 after BLM instillation than those in the control rats (artery: 1.42+/-0.63; arteriole: 1.16+/-0.34), respectively (both P<0.05). The increased positive CTGF staining areas were mainly located in the endothelium and smooth muscle layer. It is therefore concluded that CTGF expression increases in the endothelium and smooth muscle layer of pulmonary artery and arterioles during high pulmonary arterial pressure and remodeling of pulmonary artery at the early-stage of BLM-induced pulmonary fibrosis, and that the increased CTGF might be one of the mechanisms of maintenance and development of pulmonary hypertension.
Animals ; Bleomycin ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; Connective Tissue Growth Factor ; metabolism ; Hypertension, Pulmonary ; Pulmonary Artery ; metabolism ; Pulmonary Fibrosis ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo study the expression of connective tissue growth factor (CTGF) and its significance in sporadic ascending thoracic aortic aneurysm (AAA), and initially to investigate the mechanisms of pathological remodeling in AAA.

METHODSAAA specimens were taken from 18 patients during elective surgical intervention, and 18 control specimens of ascending aorta were obtained from patients undergoing coronary artery bypass surgery. Specimens were stained with HE and Masson to evaluate the arrangement and aggregation of cells and collagen types I and III; immunohistochemistry staining was performed using antibodies directed against markers of CTGF; real-time PCR analysis was performed to quantify the expression level of CTGF and collagen types I and III.

RESULTSPathological results show degradation of elastin and hyperplasia of collagen fibers as well as disordered arrangement of smooth muscle cells in AAA. When compared with controls, protein levels of CTGF were significantly increased [(44 ± 4)% vs. (33 ± 5)%, P < 0.01]. Similar patterns were shown in mRNA levels of CTGF (P < 0.01). Using real-time PCR method, elevated levels (relative expression ratio of mRNA: 10.54/3.8 and 1.79/1.19, respectively; P < 0.01, both) of collagen types I and III were observed. CTGF expression had a correlation with both collagen fibers and aortic aneurysm diameter (r = 0.784, P < 0.01; r = 0.793, P < 0.01).

CONCLUSIONSThese results indicate increased expression of aortic collagen types I and III as well as CTGF in AAA specimens, which is likely to be responsible for the aortic wall pathological remodeling. The expression of CTGF was positively correlated with the aortic diameter. As a cytokines factor can stimulate collagen synthesis, CTGF may be involved in the pathogenesis and progression of AAA.

Aged ; Aorta ; metabolism ; pathology ; Aortic Aneurysm, Thoracic ; metabolism ; pathology ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; Connective Tissue Growth Factor ; metabolism ; Female ; Humans ; Male ; Middle Aged

OBJECTIVETo investigate the feasibility of transfection of recombinant human endothelial nitric oxide synthase (eNOS) into human hypertrophic scar fibroblasts (HSFbs), and to observe NO secretion and the synthesis of collagen I and III.

METHODSRecombinant human eNOS with karyocyte expressive vector was constructed in vitro, then was transfected into HSFbs which was isolated from hypertrophic scar tissues and cultured in vitro (T group). The HSFbs untransfected (normal culture) or transfected with empty-vector was used as control group and empty-vector group respectively. The mRNA expression of eNOS, collagen I and III was determined by Realtime PCR. The content of NO was determined by NO assay kit.

RESULTSThe expression of eNOS mRNA in T group was 5.92 +/- 0.21, which was obviously higher than that in empty-vector group (0.98 +/- 0.13, P < 0.05). The expression of collagen I mRNA (0.76 +/- 0.15), and collagen III (0.79 +/- 0.08) in T group was significantly lower than those in empty-vector group (0.98 +/- 0.15, 1.02 +/- 0.12, P < 0.05, respectively). The content of NO in T group (36.1 +/- 0.8 micromol/L) was obviously higher than that in empty-vector group (28.4 +/- 1.0 micromol/L, P < 0.01) and control group (27.7 +/- 1.3 micromol/L, P < 0.01).

CONCLUSIONHSFbs can be the target cells for eNOS gene transfection. The transfected cells can express eNOS and produce NO, which inhibit the synthesis of collagen.

Cicatrix, Hypertrophic ; metabolism ; Collagen Type I ; genetics ; metabolism ; Collagen Type III ; metabolism ; Fibroblasts ; metabolism ; Humans ; In Vitro Techniques ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type III ; genetics ; RNA, Messenger ; metabolism ; Transfection

OBJECTIVETo explore the characteristics of LN and type I, III collagen in pulmonary fibrosis induced by uranium ore dust in rats.

METHODS60 adult Wistar rats were divided randomly into two groups, control group (30 rats) and uranium ore dust group (30 rats). Non-exposed intratracheal instillation method was used. Uranium ore dust group was exposed 20 mg/ml uranium ore dust suspension 1ml per rat, meanwhile control group was exposed normal saline 1ml per rat. Post-exposed the 7, 14, 21, 30 and 60 d, 6 rats in each group were killed randomly, lung tissue were collected. The pathological changes in lung tissue were observed by microscope using HE staining, the collagen I and III in lungs were observed by polarizing microscope using Biebrich scarlet staining. The expression of LN protein in lung tissue was observed by immunohistochemistry-SP.

RESULTSDuring lung fibrosis, a large amount of the proliferated I and III collagen in lungs were observed. Post-exposure to uranium ore dust, the characteristics in proliferated collagen in lungs were type I collagen deposited in lung interstitium mainly in the early stage. The area percentage of collagen I and III was increased significantly at 7, 14, 21, 30 and 60d in the experimental group as compared with that in the control group (P < 0.05 or P < 0.01). The over expression of LN in the lung tissue were observed. The expression of LN was distributed in the lung tissue as thickening of the linear or cluster. The integral optical density of LN was increased significantly at 21, 30 and 60 d in the experimental group as compared with that in the control group (P < 0.05 or P < 0.01).

CONCLUSIONSAfter exposure to uranium ore dust, the characteristics in proliferated collagen in lungs are the type of I collagen deposited in lung interstitium mainly in the early stage, while the type of III collagen increase significantly at the later period. The overexpression of LN exists in the process of pulmonary fibrosis. It suggests that LN has a role effect in the process of pulmonary fibrosis.

Animals ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; Dust ; Female ; Laminin ; metabolism ; Male ; Pulmonary Fibrosis ; chemically induced ; metabolism ; pathology ; Rats ; Rats, Wistar ; Uranium ; adverse effects

OBJECTIVETo observe the effects of complement fragment C3f on expression and secretion of collagen I, III and transforming growth factor( TGF)-beta1 in human embryonic lung fibroblast (MRC-5) cells.

METHODSMRC-5 cells were cultured with C3f (the synthetic 17 peptides fragments of complement C3). The extracellular and intracellular expression levels of type I, III collagens and TGF-beta1 in MRC-5 cultures were detected by ELISA and immunohistochemistry, respectively.

RESULTSThe expression levels of type I, III collagen and TGF-beta1 in the supernatant of MRC-5 cultures decreased significantly with the concentrations of C3f as compared with controls (P < 0.05). Also the expression level of TGF-beta1 in MRC-5 cytoplasm reduced significantly as compared with controls (P < 0.05).

CONCLUSIONThe results of present in vitro study showed that the complement fragment C3f could reduce the formation of TGF-beta1 and type I, III collagens in MRC-5 cells, and inhibit the lung tissue fibrosis.

Cell Line ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; Complement C3b ; pharmacology ; Fibroblasts ; drug effects ; metabolism ; Humans ; Lung ; cytology ; drug effects ; embryology ; Transforming Growth Factor beta1 ; metabolism

OBJECTIVETo investigate the effects of spironolactone on the concentration of collagen type I, III in the myocardium of spontaneous hypertension rats (SHR).

METHODSTwenty 8-week male SHR were assigned randomly into spironolactone (SHR-SPIRO, n=10) and control groups (SHR-CON, n=10), sex-age matched Wistar Kyoto rats (WKY group, n=7) were also served as controls. The rats of SHR-SPIRO group were given 20 mg/(kg*d) of spironolactone, the rats of SHR-CON and WKY groups were given the same volume of distilled water. After 16 weeks, the concentration of collagen type I was analyzed with Western blot. The areas of collagen type I and III were observed under polarized light microscopy and the ratio of type I/III collagen was calculated through accumulation score.

RESULTSCompared with WKY group,the concentration of collagen type I in SHR-CON group was significantly higher (1.87 ±0.2 Compared with 1.21 ±0.7, P<0.05). After 16 weeks of treatment the concentration of collagen type I (1.42 ±0.05 Compared with 1.87 ±0.2, P<0.05) and I/III ratio in SHR-SPIRO group were significantly reduced (15.64 ±1.34 Compared with 20.8 ±3.04, P<0.05) compared with SHR-CON group; but there were no differences in accumulation area scores of collagen type III among three groups (368.3 ±30.2 Compared with 481.6 ±32.4 Compared with 406.2 ±45.3, P>0.05).

CONCLUSIONThe deposition of collagen type I in myocardium may be involved in myocardial fibrosis of SHR, and spironolactone can decrease the concentration of collagen type I, which may be one of the mechanisms for its therapeutic effects.

Animals ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; Male ; Mineralocorticoid Receptor Antagonists ; pharmacology ; Myocardium ; metabolism ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY ; Spironolactone ; pharmacology

AIMTo observe the effects of hypoxia on DNA synthesis and the expression of collagen type I and III mRNA in cultured adult rat cardiac fibroblasts.

METHODSCardiac fibroblasts(CFs) were isolated from adult Wistar rat ventricule and cultured in vitro either in normoxic or hypoxic condition. Studies were conducted with the second passage of CFs. The changes of DNA synthesis was determined by measuring the incorporation of 3H-TdR into DNA and the changes of expression of pro-alpha1 (I) collagen, pro-alpha1(III) mRNA were measured by in situ hybridization respectively.

RESULTSThe 3H-TdR incorporation of CFs was increased by 34% (P < 0.05) and 36% (P < 0.01) after 6 h, 12 h hypoxia (2% O2) exposure respectively. The level of pro-alpha1(I) collagen mRNA expression was significantly elevated in the cells under hypoxia for 4 h, 8 h, and 12 h. The expression of pro-alpha1(III) mRNA increased when cells were cultured under hypoxia for 2 h.

CONCLUSIONThese results suggest that hypoxia alone can upregulate DNA synthesis and expression of collagen type I and III mRNA in adult rat cardiac fibroblasts. It may be one of the important mechanisms by which hypoxic myocardial fibrosis occur.

Animals ; Cell Hypoxia ; Cells, Cultured ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; DNA ; biosynthesis ; Fibroblasts ; metabolism ; Male ; Myocytes, Cardiac ; cytology ; RNA, Messenger ; genetics ; Rats ; Rats, Wistar

OBJECTIVETo investigate the role of recombinant human transforming growth factor beta3 (rhTGFbeta3) on fibroblast and its possible mechanism.

METHODSNormal skin fibroblast (NSFb) and hypertrophic scar fibroblast (HSFb) were cultured in vitro, and were processed by different concentrations of rhTGFbeta3. NSFb and HSFb in DMEM solution without rhTGFbeta3 were employed as control. The changes in the protein and mRNA expression of type I and III collagen in NSFb and HSFb were observed.

RESULTS(1) The expression of type I and III procollagen in NSFb was evidently different from that of HSFb (2) The synthesis of type I and III procollagen in all test groups was increased obviously after rhTGFbeta3 process (P < 0.001) while the ratio of type I to III procollagen was decreased when compared with that in control group. (3) The effects of rhTGFbeta3 on the biological behavior exhibited an obvious dose- effects relationship. The contents of type I to III procollagen in HSFb were higher than those in NSFb when the dose of rhTGFbeta3 was same.

CONCLUSIONrhTGFbeta3 could effectively promote the synthesis of type I and III procollagen, especially type III procollagen in fibroblasts. This might be beneficial to the accelerate of wound healing and to inhibit or prevent scar formation.

Cicatrix, Hypertrophic ; metabolism ; Collagen Type I ; biosynthesis ; Collagen Type III ; biosynthesis ; Fibroblasts ; drug effects ; metabolism ; Humans ; In Vitro Techniques ; Recombinant Proteins ; pharmacology ; Transforming Growth Factor beta3 ; pharmacology

OBJECTIVESTo establish the animal model of acute rotator cuff tear in rabbits, and study the effect of timing of surgical repair on healing of tendon-bone interface, formation and distribution of collagens in the supraspinatus tendon insertion and biomechanical properties of supraspinatus.

METHODSSupraspinatus tenotomy was performed in the right shoulder of 90 skeletally matured male New Zealand white rabbits to establish the animal model of acute rotator cuff tear. The rabbits were randomly divided into 3 groups : group of early repair, repaired at 1 week after tenotomy; group of late repair, repaired at 4 weeks after tenotomy; and group without repair, used as control. At 2 weeks, 4 weeks and 8 weeks after repair, healing of tendon-bone interface was observed by HE staining. Collagens were observed by Sirius Red F 3B (SR) in saturated carbazotic acid staining. The areas of type I and III collagens were measured by using imaging analysis software and the ratio of type I and III collagens were calculated. Failure loads of supraspinatus on both sides were measured. The percentage of failure loads of the surgical side was calculated and contralateral supraspinatus were uninjured.

RESULTSThere was no obvious fatty infiltration and muscle atrophy in supraspinatus in all groups. At 8 weeks, the formation of a new enthesis of supraspinatus in groups of early and late repair were observed. In groups of early and late repair, the ratio of areas of type I and III collagens at 8 weeks (2.02 ± 0.77 and 2.06 ± 0.58) was larger than that at 2 weeks (1.10 ± 0.24 and 1.14 ± 0.50, t = 3.082, 3.655, P < 0.01). At 2, 4 and 8 weeks, the percentages of failure loads of the surgical side and uninjured contralateral supraspinatus in group of early repair(38% ± 11%, 66% ± 7%, 89% ± 4%) and group of late repair (41% ± 16%, 63% ± 7%, 89% ± 9%) were both higher than that in group without repair (14% ± 6%, 32% ± 4%, 56% ± 12%); the differences were all statistically significant (group of early repair: t = 3.311, 8.549, 5.719; group of late repair: t = 3.713, 8.063, 6.044; P < 0.01). The percentage of failure loads of the surgical side and uninjured contralateral supraspinatus at 8 weeks was higher than those at 4 weeks (t = 3.878 - 4.613, P < 0.01) and 2 weeks (t = 7.158 - 10.024, P < 0.01) in all groups.

CONCLUSIONSSurgical repair within 4 weeks of acute rotator cuff tear lead to formation of a new enthesis of supraspinatus, improvement of both ratio of type I collagen in the supraspinatus tendon insertion and biomechanical properties of supraspinatus.

Animals ; Biomechanical Phenomena ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; Disease Models, Animal ; Male ; Rabbits ; Rotator Cuff ; pathology ; surgery ; Rotator Cuff Injuries ; Time Factors

Animals ; Collagen Type I ; metabolism ; Collagen Type II ; metabolism ; Collagen Type III ; metabolism ; Female ; Kinetin ; pharmacology ; Liver ; pathology ; Liver Cirrhosis, Experimental ; metabolism ; pathology ; Male ; Rats ; Rats, Wistar ; Transforming Growth Factor beta1 ; metabolism