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Collagen mRNA Expression (collagen + mrna_expression)
Selected AbstractsVitamin C attenuates ERK signalling to inhibit the regulation of collagen production by LL-37 in human dermal fibroblastsEXPERIMENTAL DERMATOLOGY, Issue 8 2010Hyun Jeong Park Please cite this paper as: Vitamin C attenuates ERK signalling to inhibit the regulation of collagen production by LL-37 in human dermal fibroblasts. Experimental Dermatology 2010; 19: e258,e264. Abstract:, Vitamin C is used as an anti-ageing agent because of its collagen enhancing effects. The precise cellular signalling mechanism of vitamin C is not well known. Here, we investigate the profibrotic mechanism of vitamin C against LL-37. Antimicrobial peptide LL-37 decreases collagen expression at mRNA and protein levels in human dermal fibroblasts (HDFs). The ability of LL-37 to inhibit collagen expression is dependent on phosphorylation of extracellular signal-regulated kinase (ERK). HDFs and human keloid fibroblasts were treated with vitamin C followed by 2 h of LL-37 treatment. Collagen mRNA expression and total soluble collagen production inhibited by LL-37 was enhanced by treatment with 0.5 mm vitamin C. Vitamin C also decreased intracellular reactive oxygen intermediates (ROI) levels that were increased by LL-37. Furthermore, the phosphorylation of ERK was analysed by Western blot following treatment with vitamin C and LL-37. Vitamin C turned off phosphorylation of ERK that was induced by LL-37. Ets-1 transcriptional factor, which is involved in the regulation of collagen expression by LL-37, was also inhibited by vitamin C. This study shows that vitamin C enhances collagen production by inhibiting the ERK pathway induced by LL-37. [source] Adenosine reverses a preestablished CCl4 -induced micronodular cirrhosis through enhancing collagenolytic activity and stimulating hepatocyte cell proliferation in ratsHEPATOLOGY, Issue 4 2001Rolando Hernández-Muñoz Cirrhosis is one of the most common causes of mortality worldwide, because hepatic dysfunction constitutes a potentially lethal condition. Having demonstrated the hepatoprotective effect of adenosine against CCl4 -induced cirrhosis, the present study was aimed at assessing adenosine's effect on an already-established micronodular cirrhosis. Chronic administration of CCl4 (10 weeks) induced a cirrhotic state, characterized by increased liver fibronectin and collagen types I and III content, enhanced expression of ,-1 (I) collagen mRNA, portal hypertension, and liver dysfunction. After CCl4 discontinuation (5 weeks), increased persitance of ,-1 (I) collagen mRNA expression and deposition, enhanced proline incorporation into collagen and prolyl hydroxylase activity evidenced active fibrogenesis. Several weeks after CCl4 withdrawal, deposited collagen showed an enhanced type I/III ratio, which was associated with deficient collagenolytic activity in cirrhotic livers. Liver expression of some metalloproteinases (MMPs) and of tissue inhibitors of MMPs (TIMPs) also indicated decreased collagen breakdown in cirrhotic livers. Parameters indicative of oxidative stress (mainly protein oxidation) were persistently augmented. These events were coincident with diminished regenerative capacity of the cirrhotic liver. Intraperitoneal adenosine administration to CCl4 -induced cirrhotic rats blocked active fibrogenesis and increased the collagen degradation (most probably by decreasing liver TIMPs levels), normalizing collagen-type ratios. In addition, the nucleoside promoted an effective hepatocyte's proliferation in the cirrhotic liver and accelerated normalization of parameters indicative of liver function and oxidative stress. Thus, adenosine readily reversed an experimental cirrhosis through stimulating liver collagenolytic and proliferative capacities, as well as by accelerating functional recovery. [source] Low-intensity pulsed ultrasound (LIPUS) increases the articular cartilage type II collagen in a rat osteoarthritis modelJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2010Kiyohito Naito Abstract In this study, the effect of low-intensity pulsed ultrasound (LIPUS) on cartilage was evaluated in a rat osteoarthritis (OA) model using serum biomarkers such as CTX-II (type II collagen degradation) and CPII (type II collagen synthesis) as well as histological criteria (Mankin score and immunohistochemical type II collagen staining). OA was surgically induced in the knee joint of rats by anterior cruciate/medial collateral ligament transection and medial meniscus resection (ACLT,+,MMx). Animals were divided into three groups: sham-operated group (Sham), ACLT,+,MMx group without LIPUS (,LIPUS), and ACLT,+,MMx group with LIPUS (+LIPUS; 30 mW/cm2, 20 min/day for 28 days). CTX-II levels were elevated in both ,LIPUS and +LIPUS groups compared to that in the Sham group after the operation, but there was no significant difference between +LIPUS and ,LIPUS groups, suggesting that LIPUS does not affect the degradation of type II collagen in this model. In contrast, CPII was significantly increased in +LIPUS group compared to ,LIPUS and Sham. Moreover, histological damage on the cartilage (Mankin score) was ameliorated by LIPUS, and type II collagen was immunohistochemically increased by LIPUS in the cartilage of an OA model. Of interest, mRNA expression of type II collagen was enhanced by LIPUS in chondrocytes. Together these observations suggest that LIPUS is likely to increase the type II collagen synthesis in articular cartilage, possibly via the activation of chondrocytes and induction of type II collagen mRNA expression, thereby exhibiting chondroprotective action in a rat OA model. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:361,369, 2010 [source] Curcumin inhibits collagen synthesis and hepatic stellate cell activation in-vivo and in-vitroJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 1 2002Hee-Chul Kang We previously demonstrated that curcumin, a well-known antioxidant, inhibits collagen deposition in carbon tetrachloride-induced liver injury in rats. The major effector cells responsible for collagen synthesis in the liver are activated hepatic stellate cells. In this study, we investigated the inhibitory effects of curcumin on the collagen synthesis and activation of rat hepatic stellate cells in-vitro, and on hepatic stellate cell activation in-vivo. The effects of curcumin on the production of collagen and smooth muscle ,-actin proteins and of ,1(I) collagen mRNA were studied in-vivo and in-vitro. The effect of curcumin on DNA synthesis was also determined in-vitro. In-vivo, treatment with curcumin reduced collagen deposition and smooth muscle ,-actin-positive areas and lowered mRNA levels of type I collagen in the liver. In-vitro, curcumin at a concentration of 5 ,g mL,1 reduced DNA synthesis, and downregulated smooth muscle ,-actin and type I collagen expression, and ,1(I) collagen mRNA expression. We concluded that curcumin inhibits collagen synthesis and hepatic stellate cell activation in-vivo and in-vitro, and thus may prove a valuable anti-fibrogenic agent. [source] Effect of phenytoin on collagen accumulation by human gingival fibroblasts exposed to TNF- ,in vitroORAL DISEASES, Issue 2 2006T Kato Objective:, Tumor necrosis factor (TNF)- , is associated with chronic gingival inflammation and reported to induce gingival overgrowth (GO), while phenytoin (PHT) is also known to be a causative agent of GO. We examined the synergistic effect of PHT and TNF- , on collagen metabolism in human gingival fibroblasts (HGFs). Materials and methods:, HGFs were cultured with TNF- , and PHT. Quantitative real-time RT-PCR was employed to determine the mRNA levels for collagen, matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs) and integrin subunits. Cellular collagen endocytosis was determined using a flow-cytometry. Results:, The proliferation of HGFs was not affected by TNF- , or PHT individually, whereas both synergistically increased collagen accumulation in HGFs. Further, collagen mRNA expression was not increased by TNF- , or PHT, although together they markedly prevented cellular collagen endocytosis, associated with the suppression of ,2,1-integrin mRNA expression. The mRNA expression of MMP-1 and-2 was suppressed by PHT, while TIMP-1 mRNA expression was enhanced by both TNF- , and PHT. Conclusion:, Our results suggest that TNF- , and PHT together cause impaired collagen metabolism by suppression of enzymatic degradation with MMPs/TIMP-1 and integrin-mediated endocytosis. These synergistic effects may also be involved in TNF- , - and PHT-induced collagen accumulation, leading to GO. [source] | ||||||||||