C. Corrales

TGF-β1 Upregulation in the Aging Varicose Vein

Background: Although the etiology of venous insufficiency is not well understood, immune response and aging are beginning to emerge as contributing factors. Factors involved in tissue remodeling such as TGF-β1 also seem to play an important role in extracellular matrix production. The aim of this study was to explore the relationship between chronic venous insufficiency and TGF-β1 examining the latent/mature form of TGF-β1 and the presence of mast cells. Effects of age were also evaluated. Methods: Saphenous veins were obtained from patients subjected to aortocoronary bypass (controls) and undergoing varicose vein surgery. These were immunolabeled using anti-LAP TGF-β1/anti-TGF-β1 antibodies and subjected to Western blot. Mast cell population was identified by metachromatic staining.Results:Latent TGF-β1 was significantly reduced in varicose veins from older subjects. In contrast, smooth muscle cells obtained from the varicosities showed intense levels. Mature TGF-β1 significantly differed between healthy and varicose veins. No mature TGF-β1 was detected in the cell cultures. Mast cell number and degranulation were increased with aging and varicose disease, colocalizing with the mature form of TGF-β1. Conclusion: Aging and varicose pathology induce dysregulation of TGF-β1 that could play an important role in the fibrous process, representing the final stages of venous insufficiency.

In vitro mesothelialization of prosthetic materials designed for the repair of abdominal wall defects

The aim of this study was to evaluate the in vitro response of mesothelial cells (MC) in terms of their ability to cover different biomaterials. MC were harvested from human omentum. The MC from the first passage were seeded onto different biomaterials from 10 min to 24 h: PL-PU99 (polypropylene-polyurethane); DM (ePTFE); PL (polypropylene); and PL + Col (polypropylene-collagen). The prosthetic surface covered was examined by microscopy and quantified. PL-PU99: The MC were adhered to the biomaterial 10 min post-incubation. At 4 h, the 53.12±7.86% of the prosthesis were coated with polygonal cells. At 12 h, 96.32±11.32% of the biomaterial was coated. DM: between 30 min to 8 h, the MC cells form small, round colonies. At 12 h, polygonal and fusiform secretory cells were observed (68.94±5.78%). 93.54±11.49% of surface was coated after 24 h. PL: only isolated cells were observed on the prosthesis. PL + Col: MC form a monolayer over prosthetic surface after 18 h (90.21±9.76). We conclude: (a) MC formed a stable monolayer over all the biomaterials tested with the exception of the PL due to its porosity. (b) The PL-PU99 showed the greatest potential for in vitro mesothelialization compared to the PL-Col and DM prostheses.

TGF‐β1 overexpression in the transversalis fascia of patients with direct inguinal hernia

Background  The aetiology of inguinal hernia includes changes in collagen turnover and metalloproteinase (MMP) expression, and direct hernia has been linked to increased MMP‐2 expression. Since transforming growth factor β1 (TGFβ1) plays a role in tissue remodelling, this growth factor could directly affect metalloproteinase secretion and thus the proteolytic activity of these enzymes. We hypothesized that TGFβ1 expression could also be altered in direct inguinal hernias.

Muscle-derived stem cells used to treat skin defects prevent wound contraction and expedite reepithelialization

Stem cells derived from adult tissues may serve as cell therapy to enhance the healing process in skin wounds. This study was designed to evaluate the use of autologous muscle‐derived stem cells in an experimental skin wound model in terms of their efficiency at promoting tissue repair/regeneration. Muscle‐derived cells obtained from the dorsal muscle of New Zealand rabbits were cultured in vitro for 2 weeks. The cell population was identified using the satellite markers CD34, m‐cadherin and Myf5, and the proliferative capacity of the adult stem cells was determined. The population was then fluorescently labeled with PKH26 and seeded onto a circular 2 cm diameter defect created on the dorsal side of the ear of the rabbit from which the cells had been harvested. Similar defects on the contra lateral ears were left untreated to form the control group. Fourteen days later, specimens were taken for light, transmission, and scanning electron microscopy, as well as for immunolabeling with antibodies against vimentin, α‐actin, desmin, myosin, fibronectin, and cytokeratin 14. Areas of wound contraction and reepithelialization were determined by image analysis. Wound contraction was significantly greater in the control than the treatment group (p<0.05); control specimens also showed more myosin expression. Reepithelialized areas were significantly greater in the treatment group (p<0.05). Control wounds showed nonepithelialized areas and inflammatory granulation tissue. Reepithelialization occurred as epidermal tongues of fusiform cells. Our findings indicate that the use of autologous stem cells on skin wounds expedites and improves the organisms natural healing process.

La vitamina D induce apoptosis en células musculares lisas

Fundamento La degeneracion de la capa media arterial es una de las caracteristicas de la arteriosclerosis que compromete tanto a las laminas elasticas como a las celulas musculares y a la matriz extracelular. Uno de los factores que aumentan la calcificacion arterial es la vitamina D que, administrada junto a una dieta hipercolesterolemica, favorece tambien el deposito de colesterol y participa en el avance de la lesion vascular. El objetivo de este trabajo fue valorar el efecto de distintas concentraciones de vitamina D2 sobre la proliferacion de celulas musculares lisas en cultivo Metodo Se utilizaron celulas musculares procedentes de arteria abdominal de rata y se ensayaron distintas concentraciones de vitamina D2 (0-200.000 U/ml) durante 2 h y hasta 4 dias. Se realizo un analisis de la proliferacion celular en el que se valoro la incorporacion de 3H-timidina y se utilizo la tecnica de TUNEL para medir el dano celular como fragmentacion del material genetico Resultados Las celulas musculares lisas del grupo control, crecidas solo con medio de cultivo, proliferan durante todo el tiempo de estudio. Sin embargo, la presencia de esta vitamina en los medios de incubacion indujo modificaciones del indice proliferativo, y se llego a paralizar el crecimiento del cultivo con la mayor dosis de vitamina utilizada. Estos hallazgos se corresponden con un aumento de la muerte cellular por apoptosis en las mismas celulas Conclusiones La vitamina D2 induce sobre las celulas musculares una inhibicion de la proliferacion y un aumento de la muerte cellular por apoptosis, y ambos parametros dependen directamente del tiempo de incubacion y de la concentracion de vitamina D utilizada