The twenty-five known matrix metalloproteases (MMPs) and their endogenous inhibitors, tissue inhibitors of metalloproteases (TIMPs), mediate cell invasion through the extracellular matrix (ECM). In a comparative three-dimensional assay, we analyzed human and mouse satellite cells' competence to invade an artificial ECM (collagen I). We identified a single MMP that 1) is expressed by human muscl...

Skin appearance is a primary indicator of age. During the last decade, substantial progress has been made toward understanding underlying mechanisms of human skin aging. This understanding provides the basis for current use and new development of antiaging treatments. Our objective is to review present state-of-the-art knowledge pertaining to mechanisms involved in skin aging, with specific foc...

Dermal fibroblasts produce a collagen-rich extracellular matrix, which confers mechanical strength and resiliency to human skin. During aging, collagen production is reduced and collagen fragmentation is increased, which is initiated by matrix metalloproteinase-1 (MMP-1). This aberrant collagen homeostasis results in net collagen deficiency, which impairs the structural integrity and function o...

Acetaldehyde, the first metabolite of ethanol, mediates many of the biological effects of ethanol. We have previously shown that acetaldehyde, but not ethanol, stimulates collagen production in cultured human fibroblasts (Holt, K., Bennett, M., and Chojkier, M. (1984) Hepatology 4, 843-848). Here, we examined the effects of acetaldehyde on collagen gene expression. Confluent human fetal fibrobl...

The aim of our research was to obtain porous matrices from collagen and collagen-hyaluronic acid and to investigate their effect on two types of human cells: fibroblasts and osteoblasts. In order to fabricate the collagenous matrices, type I collagen solution and a mixture of type I collagen and hyaluronic acid solutions, in a weight ratio of 5:1 were conditioned as sponges by freeze-drying. ES...

PURPOSE To evaluate the function of cultured human corneal endothelial cells (HCECs) in vivo and the feasibility of HCEC transplantation with a collagen sheet as the substitute carrier of HCECs. METHODS Adult human donor cornea derived from cultured HCECs was labeled with the fluorescent tracker DiI (1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate) and seeded on a collagen ...

AIM The aim of this study was to evaluate the effect of caffeine on collagen biosynthesis in human skin fibroblasts and the influence of hyaluronic acid (HA) on this process. MATERIALS AND METHODS Collagen, [(3)H]-thymidine incorporation, and prolidase activity were measured in confluent human skin fibroblast cultures that had been treated with 1, 2, and 5 mM caffeine and with caffeine and 50...

Consumption coagulopathy and hemorrhagic syndrome exacerbated by blood anticoagulability remain the most important causes of lethality associated with Bothrops snake envenomation. venom also engages platelet aggregation on injured endothelium via von Willebrand factor (vWF) interactions. Besides aggregation, some toxins may induce qualitative thrombopathy, which has been in part related to inhi...

In the pancreas, extracellular matrix (ECM) components play an import role in providing mechanical and physiological support, and also contribute to the function of islets. These ECM-connections are damaged during islet-isolation from the pancreas and are not fully recovered after encapsulation and transplantation. To promote the functional survival of human pancreatic islets, we tested differe...