Genistein Improves Skin Flap Viability in Rats: A Preliminary In Vivo and In Vitro Investigation.

Selective estrogen receptor modulators (SERMs) have been developed to achieve beneficial effects of estrogens while minimizing their side effects. In this context, we decided to evaluate the protective effect of genistein, a natural SERM, on skin flap viability in rats and in a series of in vitro experiments on endothelial cells (migration, proliferation, antioxidant properties, and gene expression profiling following genistein treatment). Our results showed that administration of genistein increased skin flap viability, but importantly, the difference is only significant when treatment is started 3 days prior the flap surgery. Based on our in vitro experiments, it may be hypothesized that the underlying mechanism may rather by mediated by increasing SOD activity and Bcl-2 expression. The gene expression profiling further revealed 9 up-regulated genes (angiogenesis/inflammation promoting: CTGF, CXCL5, IL-6, ITGB3, MMP-14, and VEGF-A; angiogenesis inhibiting: COL18A1, TIMP-2, and TIMP-3). In conclusion, we observed a protective effect of genistein on skin flap viability which could be potentially applied in plastic surgery to women undergoing a reconstructive and/or plastic intervention. Nevertheless, further research is needed to explain the exact underlying mechanism and to find the optimal treatment protocol.

Genistein: a promising molecule modulating tumour growth and wound healing?

Although it has been shown that oestrogen replacement therapy is able to improve wound healing, several side effects of this replacement therapy have precluded its common use in clinical practice. On the other hand, the phytoestrogen genistein (the selective oestrogen receptor modulator belonging to the group of isoflavones) has been introduced into several clinical trials to improve cancer treatment efficiency and experiments suggest its positive effect on wound healing. The main mechanisms of action, which have been elucidated so far, include induction of apoptosis, cell cycle arrest, inhibition of angiogenesis and tyrosine kinase activity as well as cancer chemoprevention and reduction of climacteric symptoms. Unfortunately, all underlying mechanism in the modulation of biological processes involved in wound healing and tumour growth are not yet fully understood. Therefore, the present review summarizes the effects of genistein on biological processes in different wound healing models and selected tumours. Key words: genistein • tissue repair and regeneration • carcinoma • skin.

[Basic biological roles of galectins in tissue repair and tumor growth]. / Základné biologické úlohy galektínov v reparácii tkanív a raste nádorov.

Galectins are representatives of endogenous lectins - molecules specifically recognizing distinct sugar motifs. They play an important role in the processes of cell proliferation, differentiation, migration and extracellular matrix formation. Furthermore, galectins are able to transfer cellular signals and to participate in intercellular interaction. It has been proven that galectins play an important role in the formation of tumor and/or wound healing microenvironment. This review contains an overview of experimental and clinical studies dealing with biological roles of galectins in tissue repair and in its parallel - the tumor growth.

Human galectin­3: Molecular switch of gene expression in dermal fibroblasts in vitro and of skin collagen organization in open wounds and tensile strength in incisions in vivo.

Understanding the molecular and cellular processes in skin wound healing can pave the way for devising innovative concepts by turning the identified natural effectors into therapeutic tools. Based on the concept of broad­scale engagement of members of the family of galactoside­binding lectins (galectins) in pathophysiological processes, such as cancer or tissue repair/regeneration, the present study investigated the potential of galectins­1 (Gal­1) and ­3 (Gal­3) in wound healing. Human dermal fibroblasts, which are key cells involved in skin wound healing, responded to galectin exposure (Gal­1 at 300 or Gal­3 at 600 ng/ml) with selective changes in gene expression among a panel of 84 wound­healing­related genes, as well as remodeling of the extracellular matrix. In the case of Gal­3, positive expression of Ki67 and cell number increased when using a decellularized matrix produced by Gal­3­treated fibroblasts as substrate for culture of interfollicular keratinocytes. In vivo wounds were topically treated with 20 ng/ml Gal­1 or ­3, and collagen score was found to be elevated in excisional wound repair in rats treated with Gal­3. The tensile strength measured in incisions was significantly increased from 79.5±17.5 g/mm2 in controls to 103.1±21.4 g/mm2 after 21 days of healing. These data warrant further testing mixtures of galectins and other types of compounds, for example a combination of galectins and TGF­ß1.

Pharmacological activation of estrogen receptors-α and -ß differentially modulates keratinocyte differentiation with functional impact on wound healing.

Estrogen deprivation is considered responsible for many age-related processes, including poor wound healing. Guided by previous observations that estradiol accelerates re­epithelialization through estrogen receptor (ER)­ß, in the present study, we examined whether selective ER agonists [4,4',4''-(4-propyl [1H] pyrazole-1,3,5-triyl)­trisphenol (PPT), ER­α agonist; 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN), ER­ß agonist] affect the expression of basic proliferation and differentiation markers (Ki­67, keratin­10, ­14 and ­19, galectin­1 and Sox­2) of keratinocytes using HaCaT cells. In parallel, ovariectomized rats were treated daily with an ER modulator, and wound tissue was removed 21 days after wounding and routinely processed for basic histological analysis. Our results revealed that the HaCaT keratinocytes expressed both ER­α and ­ß, and thus are well-suited for studying the effects of ER agonists on epidermal regeneration. The activation of ER­α produced a protein expression pattern similar to that observed in the control culture, with a moderate expression of Ki­67 being observed. However, the activation of ER­ß led to an increase in cell proliferation and keratin­19 expression, as well as a decrease in galectin­1 expression. Fittingly, in rat wounds treated with the ER­ß agonist (DPN), epidermal regeneration was accelerated. In the present study, we provide information on the mechanisms through which estrogens affect the expression patterns of selected markers, thus modulating keratinocyte proliferation and differentiation; in addition, we demonstrate that the pharmacological activation of ER-α and -ß has a direct impact on wound healing.

Plantago lanceolata†L. water extract induces transition of fibroblasts into myofibroblasts and increases tensile strength of healing skin wounds.

OBJECTIVES: Although the exact underlying mechanisms are still unknown, Plantago lanceolata L. (PL) water extracts are frequently used to stimulate wound healing and to drain abscesses. Therefore, in this experimental study the effect of PL water extract on skin wound healing was studied in Sprague-Dawley rats. METHODS: Two excisional and one incisional skin wounds were performed on the back of each rat. Wounds were treated for three consecutive days with two different concentrations of the aqueous extract of PL. Rats were sacrificed 7, 14, and 21 days after surgery. Samples of wounds were processed for macroscopic (excisions - wound contraction measurement), biomechanical (incisions - wound tensile strength (TS) measurement) and histological examination (excisions). KEY FINDINGS: It was shown that open wounds treated with PL extract contained myofibroblasts and demonstrated significantly higher contraction rates. Furthermore, significantly increased wound TSs were recorded in treated rats as a consequence of increased organization of extracellular matrix proteins, such as the collagen type 1. CONCLUSIONS: We demonstrated that PL aqueous extract improves skin wound healing in rats. However, further research need to be performed to find optimal therapeutic concentration, and exact underlying mechanism prior obtained results may be introduced into the clinical practice.

Extracellular matrix of galectin-1-exposed dermal and tumor-associated fibroblasts favors growth of human umbilical vein endothelial cells in vitro: a short report.

BACKGROUND/AIM: Stromal cells in the tumor microenvironment are primarily considered as sources of promalignant factors. The objective of our study was to define the effect of extracellular matrix (ECM) produced by normal dermal or cancer-associated fibroblasts exposed to adhesion/growth-regulatory lectin galectin-1 on human umbilical vein endothelial cells (HUVECs). MATERIALS AND METHODS: Fibroblasts were cultured for 10 days with lectin, followed by removing cellular constituents after an osmotic shock. Freshly-isolated HUVECs were placed on the ECM. In parallel, HUVECs were seeded on untreated and gelatin-coated surfaces as controls. A positive control for growth of HUVECs culture using medium supplemented with vascular endothelial growth factor completed the test panel. Cells were kept in contact to the substratum for two days and then processed for immunocytochemistry. RESULTS: HUVECs seeded on fibroblast-generated ECM presented a comparatively high degree of proliferation. Furthermore, contact to substratum produced by tumor-associated fibroblasts led to generation of a meshwork especially rich in fibronectin. CONCLUSION: Galectin-1 is apparently capable to trigger ECM production favorable for growth of HUVECs, prompting further work on characterizing structural features of the ECM and in situ correlation of lectin presence, ECM constitution and neoangiogenesis.