Upregulated Collagen Production Research Articles

Porcine Placenta Peptide Inhibits UVB-Induced Skin Wrinkle Formation and Dehydration: Insights into MAPK Signaling Pathways from In Vitro and In Vivo Studies.

Excessive exposure to ultraviolet (UV) radiation from sunlight accelerates skin aging, leading to various clinical manifestations such as wrinkles, dryness, and loss of elasticity. This study investigated the protective effects of porcine placenta peptide (PPP) against UVB-induced skin photoaging. Female hairless SKH-1 mice were orally administered PPP for 12 weeks, followed by UVB irradiation. PPP significantly reduced wrinkle formation, improved skin moisture levels, and prevented collagen degradation. Mechanistically, PPP inhibited the expression of matrix metalloproteinases (MMPs) and upregulated collagen production. Moreover, PPP elevated hyaluronic acid levels, contributing to enhanced skin hydration. Additionally, PPP demonstrated antioxidant properties by increasing the expression of the antioxidant enzyme GPx-1, thereby reducing UVB-induced inflammation. Further molecular analysis revealed that PPP suppressed the activation of p38 MAP kinase and JNK signaling pathways, crucial mediators of UV-induced skin damage. These findings highlight the potential of porcine placental peptides as a natural and effective intervention against UVB-induced skin photoaging. The study provides valuable insights into the mechanisms underlying the protective effects of PPP, emphasizing its potential applications in skincare and anti-aging formulations.

The Histamine 3 Receptor Is Expressed in the Heart and Its Activation Opposes Adverse Cardiac Remodeling in the Angiotensin II Mouse Model.

Histamine is a basic amine stored in mast cells, with its release capable of activating one of four histamine receptors. The histamine 3 receptor (H3R) is known to be cardioprotective during acute ischemia by acting to limit norepinephrine release. However, a recent study reported that myofibroblasts isolated from the infarct zone of rat hearts responded to H3R activation by up-regulating collagen production. Thus, it is necessary to clarify the potential role of the H3R in relation to fibrosis in the heart. We identified that the mouse left ventricle (LV) expresses the H3R. Isolation of mouse cardiac fibroblasts determined that while angiotensin II (Ang II) increased levels of the H3R, these cells did not produce excess collagen in response to H3R activation. Using the Ang II mouse model of adverse cardiac remodeling, we found that while H3R blockade had little effect on cardiac fibrosis, activation of the H3R reduced cardiac fibrosis and macrophage infiltration. These findings suggest that when activated, the H3R is anti-inflammatory and anti-fibrotic in the mouse heart and may be a promising target for protecting against cardiac fibrosis.

Identification of TGF-β receptor-1 as a key regulator of carbon nanotube-induced fibrogenesis.

Carbon nanotubes (CNTs) induce rapid interstitial lung fibrosis, but the underlying mechanisms are unclear. Previous studies indicated that the ability of CNTs to penetrate lung epithelium, enter interstitial tissue, and stimulate fibroblasts to produce collagen matrix is important to lung fibrosis. In this study, we investigated the activation of transforming growth factor-β receptor-1 [TGF-β R1; i.e., activin receptor-like kinase 5 (ALK5) receptor] and TGF-β/Smad signaling pathway in CNT-induced collagen production in human lung fibroblasts. Human lung fibroblasts and epithelial cells were exposed to low, physiologically relevant concentrations (0.02-0.6 μg/cm(2)) of single-walled CNTs (SWCNT) and multiwalled CNTs (MWCNT) in culture and analyzed for collagen, TGF-β1, TGF-β R1, and SMAD proteins by Western blotting and immunofluorescence. Chemical inhibition of ALK5 and short-hairpin (sh) RNA targeting of TGF-β R1 and Smad2 were used to probe the fibrogenic mechanism of CNTs. Both SWCNT and MWCNT induced an overexpression of TGF-β1, TGF-β R1 and Smad2/3 proteins in lung fibroblasts compared with vehicle or ultrafine carbon black-exposed controls. SWCNT- and MWCNT-induced collagen production was blocked by ALK5 inhibitor or shRNA knockdown of TGF-β R1 and Smad2. Our results indicate the critical role of TGF-β R1/Smad2/3 signaling in CNT-induced fibrogenesis by upregulating collagen production in lung fibroblasts. This novel finding may aid in the design of mechanism-based risk assessment and development of rapid screening tests for nanomaterial fibrogenicity.

Up-regulation of interleukin-22 mediates liver fibrosis via activating hepatic stellate cells in patients with hepatitis C

Interleukin-22 (IL-22) is known to play a critical role in liver immunity. However, the role of IL-22 in HCV-associated liver fibrosis is poorly understood. In this study, patients with HCV infection disclosed significant increases in peripheral numbers of IL-22-producing cells as well as in IL-22 plasma levels. In the liver, the increased intrahepatic IL-22+ cells were positively correlated with fibrotic staging scores and clinical progression from CHC to cirrhosis. Moreover, the majority of IL-22+ cells were located in fibrotic areas in the liver of patients with cirrhosis and co-localized with α-smooth muscle actin (α-SMA) positive hepatic stellate cells (HSCs). In vitro, administration of IL-22 was accompanied with inhibited LX-2 cell apoptosis, promoted LX-2 cell proliferation, increased expression of α-SMA, and up-regulated collagen production by LX-2 cells. Collectively, our data provide evidence that IL-22 may contribute to the fibrogenesis of HCV-associated liver fibrosis by activating HSCs.

Interleukin‐21 mediates hepatitis B virus‐associated liver cirrhosis by activating hepatic stellate cells

Interleukin-21 (IL-21) is involved in effective primary hepatic immune response against hepatitis B virus (HBV) and profibrotic function. However, the role of IL-21 in HBV-associated liver cirrhosis is poorly understood. This study aimed to investigate the role of IL-21 in HBV-associated liver cirrhosis and possible mechanisms. The study subjects included 10 healthy controls and 30 patients with HBV-associated liver cirrhosis that categorized into three subgroups based on Child-Pugh score (A, 13; B, 10; C, 7). The frequencies of IL-21(+) CD4(+) T cells were detected by flow cytometry, and the level of IL-21 in plasma was measured by enzyme-linked immunoassay. The distribution of IL-21(+) cells in situ in liver was observed by immunohistochemistry. In addition, the in vitro expression of α-smooth muscle actin (α-SMA), apoptosis and proliferation markers of LX-2 cells were examined by flow cytometry and Cell Counting Kit-8 kit. Finally, the collagen levels in the supernatant were measured by chemiluminescence. Increased peripheral number of IL-21(+) CD4(+) cells, elevated plasma level of IL-21 and IL-21(+) cell accumulation in liver were observed in patients with HBV-associated liver cirrhosis. In vitro administration of IL-21 was accompanied with increased expression of α-SMA, inhibited LX-2 cells apoptosis and upregulated collagen production by LX-2 cells. IL-21 may contribute to the fibrogenesis of HBV-associated liver cirrhosis by activating the hepatic stellate cells. Therefore, neutralization of IL-21 could be a favorable new therapeutic strategy for liver cirrhosis treatment.

Tendon Healing in Vivo and in Vitro: Neutralizing Antibody to TGF-β Improves Range of Motion After Flexor Tendon Repair

Adhesion formation between the flexor tendon and its surrounding fibro-osseous sheath results in a decreased postoperative range of motion (ROM) in the hand. Transforming growth factor-beta (TGF-β) is a key cytokine in the pathogenesis of tissue fibrosis. In this study, the effects of TGF-β1 neutralizing antibody were investigated in vitro and in vivo. In the in vitro investigation, primary cell cultures from rabbit flexor tendon sheath, epitenon, and endotenon were established and each was supplemented with TGF-β along with increasing doses of TGF-β1 neutralizing antibody. Collagen I production was measured with enzyme-linked immunosorbent assay. In the in vivo study, rabbit zone-II flexor tendons were transected and then immediately repaired. Transforming growth factor-β1 neutralizing antibody or phosphate-buffered saline solution (control) was added to the repair sites, and the forepaws were tested for ROM and repair strength at 8 weeks postoperatively. Transforming growth factor-β1 neutralizing antibody reduced TGF-β upregulated collagen production. Intraoperative application of TGF-β1 neutralizing antibody significantly improved the ROM of the operatively treated digits. The effect on breaking strength of the tendon repair was inconclusive.

Mechanisms of skin fibrosis in systemic sclerosis

Systemic sclerosis (SSc) or scleroderma is an acquired disorder which typically results in fibrosis of the skin and internal organs. Skin fibrosis, the hallmark of this disease, is defined as excess deposition and accumulation of extracellular matrix, mainly type I collagen, in the dermis. Dermal fibroblasts isolated from lesional skin of SSc patients and cultured in vitro exhibit increased synthesis of collagen and decreased collagenase activity, consistent with the disease phenotype. This review focuses on the recent progress in the research for molecular mechanisms of skin fibrosis in SSc. The upregulated collagen production at transcriptional level in SSc fibroblasts involves various regulators including cytokines or transcription factors. Among them, transforming growth factor (TGF)-beta/Smad signaling is likely to play a key role in the pathogenesis of SSc, and the autocrine TGF-beta signaling hypothesis can explain intrinsic activation of collagen promoter in SSc fibroblasts. Imbalance between matrix metalloproteinases and tissue inhibitor of metalloproteinases might also contribute to the excess accumulation of collagen in the dermis.

MANNOSE-6-PHOSPHATE, AN INHIBITOR OF TRANSFORMING GROWTH FACTOR-?, IMPROVES RANGE OF MOTION AFTER FLEXOR TENDON REPAIR

Background: Adhesion formation between the flexor tendon and its surrounding fibro-osseous sheath results in a decreased postoperative range of motion in the hand. Transforming growth factor-beta (TGF-β) is a key cytokine in the pathogenesis of tissue fibrosis. In this study, the effects of two natural inhibitors of TGF-β, decorin and mannose-6-phosphate, were investigated in vitro and in vivo. Methods: In the in vitro investigation, primary cell cultures from rabbit flexor tendon sheath, epitenon, and endotenon were established and each was supplemented with TGF-β along with increasing doses of decorin or mannose-6-phosphate. Collagen-I production was measured with enzyme-linked immunosorbent assay (ELISA). For the in vivo study, rabbit zone-II flexor tendons were transected and then immediately repaired. Single intraoperative graded doses of decorin, mannose-6-phosphate, or phosphate-buffered saline solution (control) were added to the repair sites, and the forepaws were tested for the range of motion and repair strength at eight weeks postoperatively. Results: Decorin and mannose-6-phosphate both reduced TGF-β upregulated collagen production. Intraoperative application of low-dose mannose-6-phosphate significantly improved the range of motion of the operatively treated digits. The effect on breaking strength of the tendon repair was inconclusive. Conclusions: Mannose-6-phosphate is effective in reducing TGF-β upregulated collagen production in an in vitro model. This finding correlated with our in vivo finding that a single intraoperative dose of mannose-6-phosphate improved the postoperative range of motion. Clinical Relevance: Mannose-6-phosphate is ubiquitous, nonimmunogenic, and easily produced, making it an ideal candidate for clinical application to reduce adhesion formation after flexor tendon repair.

Mannose-6-Phosphate, an Inhibitor of Transforming Growth Factor-β, Improves Range of Motion After Flexor Tendon Repair

Adhesion formation between the flexor tendon and its surrounding fibro-osseous sheath results in a decreased postoperative range of motion in the hand. Transforming growth factor-beta (TGF-beta) is a key cytokine in the pathogenesis of tissue fibrosis. In this study, the effects of two natural inhibitors of TGF-beta, decorin and mannose-6-phosphate, were investigated in vitro and in vivo. In the in vitro investigation, primary cell cultures from rabbit flexor tendon sheath, epitenon, and endotenon were established and each was supplemented with TGF-beta along with increasing doses of decorin or mannose-6-phosphate. Collagen-I production was measured with enzyme-linked immunosorbent assay (ELISA). For the in vivo study, rabbit zone-II flexor tendons were transected and then immediately repaired. Single intraoperative graded doses of decorin, mannose-6-phosphate, or phosphate-buffered saline solution (control) were added to the repair sites, and the forepaws were tested for the range of motion and repair strength at eight weeks postoperatively. Decorin and mannose-6-phosphate both reduced TGF-beta upregulated collagen production. Intraoperative application of low-dose mannose-6-phosphate significantly improved the range of motion of the operatively treated digits. The effect on breaking strength of the tendon repair was inconclusive. Mannose-6-phosphate is effective in reducing TGF-beta upregulated collagen production in an in vitro model. This finding correlated with our in vivo finding that a single intraoperative dose of mannose-6-phosphate improved the postoperative range of motion.

A key enzyme upregulating collagen production by scleroderma fibroblasts

A key enzyme upregulating collagen production by scleroderma fibroblasts

Expression of RANTES in biopsies of skin and upper gastrointestinal tract from patients with systemic sclerosis

Inflammatory infiltrates and upregulated collagen production are hallmarks of systemic sclerosis (SSc). There are indications that chemokines are involved in accumulation of inflammatory and matrix-synthesizing cells in SSc skin lesions. Therefore, we searched for the expression and localization of the chemokine RANTES ("regulated upon activation and normal T cells expressed and secreted") in skin and esophageal biopsies from patients with SSc. Using immunohistochemistry and in situ hybridization, skin biopsies derived from clinically involved and noninvolved skin of 18 patients with early and long-term SSc were examined for RANTES expression and compared with nondiseased skin sections of seven patients without SSc. In addition, esophageal snap biopsies were taken in a subgroup of six SSc patients. Strong expression of RANTES could be detected in the epidermis in keratinocytes of patients with short-term and long-term disease, both on the mRNA and protein level. The percentage of RANTES-expressing cells were significantly higher in clinically noninvolved skin sections than in involved skin areas. In contrast, no RANTES expression was found in esophageal biopsies or in the control group. The results indicate that RANTES is present in human sclerodermatous skin. RANTES may be involved in early pathogenesis of SSc as well as in fibrosis pathways, either by chemoattraction of immunocompetent cells and/or by modulation of collagen production.

Subsets of murine lung fibroblasts express membrane-bound and soluble IL-4 receptors. Role of IL-4 in enhancing fibroblast proliferation and collagen synthesis.

The purpose of this study was to determine whether or not membrane-bound and soluble forms of IL-4 receptors are expressed by isolated subsets of murine lung fibroblasts and to evaluate the potential functional consequences of IL-4 receptor triggering. Recent studies demonstrate that IL-4-synthesizing Th2 cells and mast cells are present in increased numbers in the lung during inflammation and fibrosis, suggesting that IL-4 may play a regulatory role in these events. We hypothesize that pulmonary fibroblasts and subsets thereof are intimately involved in this inflammatory response and that IL-4 is an active player in stimulating fibroblast collagen synthesis and hyperproliferation, creating a fibrotic environment in the lung. The fibroblast subsets used in these experiments differ not only in surface expression of the thymocyte-1 (Thy-1) Ag, but also in function and morphology. We now report the novel finding that IL-4 receptors are present at discordant levels on Thy-1+ and Thy-1- lung fibroblasts. IL-4R level and affinity were analyzed using a monoclonal anti-IL-4R Ab and equilibrium binding analysis with 125I-labeled IL-4. Reverse transcriptase PCR demonstrated the presence of mRNA for membrane-bound and soluble IL-4R. Lung fibroblast subsets secrete soluble IL-4R protein at dramatically different levels, as detected by an ELISA. Thy-1+ and Thy-1- lung fibroblasts were treated with IL-4 to determine whether this cytokine was profibrotic. Thy-1+ fibroblasts responded to IL-4 by proliferating and up-regulating collagen production. In contrast, Thy-1- fibroblasts proliferate to a lesser degree than Thy-1+ fibroblasts and were not stimulated to secrete increased levels of collagen. Overall, these results suggest that elevated levels of IL-4 at a site of injury could result in the development of fibrosis by enhancing fibroblast subset proliferation and collagen synthesis.