Collagen-Binding Peptidoglycans Inhibit MMP Mediated Collagen Degradation and Reduce Dermal Scarring

Scarring of the skin is a large unmet clinical problem that is of high patient concern and impact. Wound healing is complex and involves numerous pathways that are highly orchestrated, leaving the skin sealed, but with abnormal organization and composition of tissue components, namely collagen and proteoglycans, that are then remodeled over time. To improve healing and reduce or eliminate scarring, more rapid restoration of healthy tissue composition and organization offers a unique approach for development of new therapeutics. A synthetic collagen-binding peptidoglycan has been developed that inhibits matrix metalloproteinase-1 and 13 (MMP-1 and MMP-13) mediated collagen degradation. We investigated the synthetic peptidoglycan in a rat incisional model in which a single dose was delivered in a hyaluronic acid (HA) vehicle at the time of surgery prior to wound closure. The peptidoglycan treatment resulted in a significant reduction in scar tissue at 21 days as measured by histology and visual analysis. Improved collagen architecture of the treated wounds was demonstrated by increased tensile strength and transmission electron microscopy (TEM) analysis of collagen fibril diameters compared to untreated and HA controls. The peptidoglycan's mechanism of action includes masking existing collagen and inhibiting MMP-mediated collagen degradation while modulating collagen organization. The peptidoglycan can be synthesized at low cost with unique design control, and together with demonstrated preclinical efficacy in reducing scarring, warrants further investigation for dermal wound healing

In vitro analysis of the effects on wound healing of high- and low-molecular weight chains of hyaluronan and their hybrid H-HA/L-HA complexes

Abstract Background: Recent studies have reported the roles of Hyaluronic acid (HA) chains of diverse length in wound repair, especially considering the simultaneous occurrence in vivo of both high- (H-HA) and low-molecular weight (L-HA) hyaluronan at an injury site. It has been shown that HA fragments (5 ≤ MW ≤ 20 kDa) usually trigger an inflammatory response that, on one hand, is the first signal in the activation of a repair mechanism but on the other, when it’s overexpressed, it may promote unwanted side effects. The present experimental research has aimed to investigate H-HA, L-HA and of a newly developed complex of the two (H-HA/L-HA) for stability (e.g. hyaluronidases digestion), for their ability to promote wound healing of human keratinocytes in vitro and for their effect on cellular biomarker expression trends. Results: Time-lapse video microscopy studies proved that the diverse HA was capable of restoring the monolayer integrity of HaCat. The H-HA/L-HA complex (0.1 and 1%w/v) proved faster in regeneration also in co-culture scratch test where wound closure was achieved in half the time of H-HA stimulated cells and 2.5-fold faster than the control. Gene expression was evaluated for transformation growth factor beta 1 (TGF-β1) proving that L-HA alone increased its expression at 4 h followed by restoration of similar trends for all the stimuli. Depending on the diverse stimulation (H-HA, L-HA or the complex), metalloproteinases (MMP-2, -9, -13) were also modulated differently. Furthermore, type I collagen expression and production were evaluated. Compared to the others, persistence of a significant higher expression level at 24 h for the H-HA/L-HA complex was found. Conclusions: The outcomes of this research showed that, both at high and low concentrations, hybrid complexes proved to perform better than HA alone thus suggesting their potential as medical devices in aesthetic and regenerative medicine. Keywords: Wound healing, Hyaluronan, MMPs, Hybrid complexe

Transforming growth factor-beta 1 in adipose derived stem cells conditioned medium is a dominant paracrine mediator determines hyaluronic acid and collagen expression profile

Conditioned medium from adipose derived stem cells (ADSC-CM) stimulates both collagen synthesis and migration of fibroblasts, and accelerates wound healing in vivo. Recently, the production and secretion of growth factors has been identified as an essential function of adipose-derived stem cells (ADSCs). However, the main soluble factor of ADSC-CM which mediates paracrine effects and its underlying mechanism has not been elucidated yet. In this study, we considered transforming growth factor-beta1 (TGF-β1) as a strong candidate for paracrine effect of ADSC-CM and investigated collagen synthesis and hyaluronic acid synthase (HAS) expression. After ADSC-CM addition, collagen type I, type III, HAS and hyaluronic acid (HA) expressions on human dermal fibroblasts (HDFs) were evaluated. Furthermore, to clarify effects of TGF-β1 as a paracrine mediator, TGF-β1 antibody and external supplementary TGF-β1 were treated to HDFs. Collagens type I, type III, HAS-1 and HAS-2 mRNA expressions of HDFs were greatly increased by ADSC-CM treatment, however there was no change in TGF-β1 antibody treated HDFs compared with non-treated control. These results strongly demonstrate that TGF-β1 plays an important role as a paracrine mediator of ECM synthesis. The fact that TGF-β1 contained in ADSC-CM not only accelerates collagen deposition but also increase hyaluronic acid synthesis of HDFs through HAS-1 and HAS-2 expression was also elucidated in this study. Therefore, ADSC-CM shows promise for the treatment of cutaneous wounds and accelerates granulation formation during healing process

TGFβ counteracts LYVE-1-mediated induction of lymphangiogenesis by small hyaluronan oligosaccharides

During tissue injury, inflammation, and tumor growth, enhanced production and degradation of the extracellular matrix glycosaminoglycan hyaluronan (HA) can lead to the accumulation of small HA (sHA) oligosaccharides. We have previously reported that accumulation of sHA in colorectal tumors correlates with lymphatic invasion and lymph node metastasis, and therefore, investigated here are the effects of sHA on the lymphatic endothelium. Using cultured primary lymphatic endothelial cells (LECs) and ex vivo and in vivo lymphangiogenesis assays, we found that in contrast to high-molecular-weight HA (HMW-HA), sHA of 4–25 disaccharides in length can promote the proliferation of LECs and lymphangiogenesis in a manner that is dependent on their size and concentration. At pathophysiologically relevant concentrations found in tumor interstitial fluid, sHA is pro-proliferative, acts synergistically with VEGF-C and FGF-2, and stimulates the outgrowth of lymphatic capillaries in ex vivo lymphangiogenesis assays. In vivo, intradermally injected sHA acts together with VEGF-C to increase lymphatic vessel density. Higher concentrations of sHA were found to induce expression of the anti-lymphangiogenic cytokine TGFβ in LECs, which serves to counter-regulate sHA-induced LEC proliferation and lymphangiogenesis. Using appropriate knockout mice and blocking antibodies, we found that the effects of sHA are mediated by the sialylated form of the lymphatic HA receptor LYVE-1, but not by CD44 or TLR-4. These data are consistent with the notion that accumulation of sHA in tumors may contribute to tumor-induced lymphangiogenesis, leading to increased dissemination to regional lymph nodes