Human Galectins Induce Conversion of Dermal Fibroblasts into Myofibroblasts and Production of Extracellular Matrix: Potential Application in Tissue Engineering and Wound Repair

Members of the galectin family of endogenous lectins are potent adhesion/growth-regulatory effectors. Their multi-functionality opens possibilities for their use in bioapplications. We studied whether human galectins induce the conversion of human dermal fibroblasts into myofibroblasts (MFBs) and the production of a bioactive extracellular matrix scaffold is suitable for cell culture. Testing a panel of galectins of all three subgroups, including natural and engineered variants, we detected activity for the proto-type galectin-1 and galectin-7, the chimera-type galectin-3 and the tandem-repeat-type galectin-4. The activity of galectin-1 required the integrity of the carbohydrate recognition domain. It was independent of the presence of TGF-beta 1, but it yielded an additive effect. The resulting MFBs, relevant, for example, for tumor progression, generated a matrix scaffold rich in fibronectin and galectin-1 that supported keratinocyte culture without feeder cells. Of note, keratinocytes cultured on this substratum presented a stem-like cell phenotype with small size and keratin-19 expression. In vivo in rats, galectin-1 had a positive effect on skin wound closure 21 days after surgery. In conclusion, we describe the differential potential of certain human galectins to induce the conversion of dermal fibroblasts into MFBs and the generation of a bioactive cell culture substratum. Copyright (C) 2011 S. Karger AG, Base

Glycobiology of squamous epithelium - in vitro and in vivo

The skin is the largest organ of human body and its severe damage can cause even death of a patient. As the allografting of skin can not create permanent closure of wounds, the treatment (especially in cases of burn injuries) is rather demanding and prolonged. In my work I focused on determination of glycobiologic characteristcs of squamous cell epithelium, especially the skin, under normal and pathological conditions. Those results which we have obtained could be used for development of new methods of keratinocyte cultivation for clinical purposes. Epidermis was the very first human tissue that was prepared in vitro and returned back to the patient however the results of these transplantations were not satisfactory. (...) A new method of cultivation and transfer of keratinocytes on polymer support was developed. This way of cultivation of epidermal grafts exhibits some advantages compared with confluent sheets attached to textile. Namely the shortening of the cultivation period and the deletion of enzymatic detachment of the cells, that negatively influence their viability, are the main benefits. First of all the hydrogel support protects the cells from infection and desiccation after its application to the wound bed. So the optimal microclimate for the attachment and spreading of transplanted cells is..

Titanium Disc Modified with Hydroxyapatite and Zirconia Does not Reveal Signs of Cytotoxicity

The paper deals primarily with the study of biological properties of a model of implant covered with a thin layer of hydroxyapatite with an intermediate layer of zirconium. Cytotoxicity was evaluated by direct cultivation with mouse and human fibroblasts. A physical test using X-ray diffraction confirmed that the film is composed of crystalline hydroxyapatite. The evaluation of the cytotoxicity test and a comparison with controlled samples cultured in parallel in vitro made it possible to conclude that the material is not cytotoxic audit is suitable for further experiments in more detail

Ecology of melanoma cell

Melanoma represents a cancer with increasing incidence worldwide and limited curability of advanced stages of the disease. Similarly to other types of tumors, the microenvironment is an important factor that participates in the control of melanoma biological properties. This review summarizes data regarding the role of the microenvironment, namely fibroblasts, keratinocytes and infiltrating immune cells, on melanoma growth and spreading. The role of embryonic microenvironment on melanoma cell biological properties is also discussed. The potential of therapeutic targeting of the melanoma microenvironment is demonstrated

Emerging role of tissue lectins as microenvironmental effectors in tumors and wounds

Detailed comparative analysis of at first sight not related process cascades is a means toward this aim: to trace common effector mechanisms and hereby eventually inspire innovative routes for therapeutic management. Following this concept, promotion of tumor progression by stroma, especially cancerassociated fibroblasts and smooth muscle actin-positive myofibroblasts, and beneficial activity of respective cells in wound healing have helped to delineate the involvement of endogenous lectins of the family of galectins. In addition to initiating conversion of fibroblasts to myofibroblasts, galectin-1 instructs the cells to produce a structurally complex extracellular matrix. This bioscaffold is useful for keratinocyte culture, also apparently operative in ameliorating wound healing. These functional aspects encourage to study in detail how lectin-(glycan) counterreceptor display is orchestrated. Such insights are assumed to have potential to contribute to rationally manipulate stem/precursor cells as resource in regenerative medicine