The anti-inflammatory agent Propolis improves wound healing in a rodent model of experimental diabetes.

Foot ulcers and poor wound healing are problematic for patients with diabetes. The beehive protectant Propolis can improve wound healing but whether it can improve healing in diabetic wounds has not been investigated. In this study, the effect of a single application of Propolis on epithelial closure, wound morphology, cellular infiltrate, and blood vessel density were investigated. Diabetes was induced in rats using streptozocin. After 6 weeks, diabetic and control animals were wounded and the wounds were treated with Propolis or saline as control. At days 6 and 12 animals were sacrificed and wounds were excised. Compared with controls, diabetes decreased epithelial closure and reepithelialization but had no effect on wound contraction. These delays were prevented by Propolis. At day 12, the impaired macrophage infiltration (C:1.49+/-0.09 vs. D:0.25+/-0.14), persistent neutrophil infiltration (C:0.22+/-0.19 vs. D:1.33+/-0.81), and increased myeloperoxidase activity (fourfold) in diabetic wounds were prevented by Propolis. Diabetes had no effect on wound volume, vessel number, or branch points. These novel data indicate that Propolis can accelerate wound healing in diabetes. As neutrophil infiltration is normalized, its mechanism of action may be through anti-inflammatory pathways. This result and the established safety profile of Propolis provide a rationale for studying topical application of this agent in a clinical setting.

WNT7b mediates macrophage-induced programmed cell death in patterning of the vasculature.

Macrophages have a critical role in inflammatory and immune responses through their ability to recognize and engulf apoptotic cells. Here we show that macrophages initiate a cell-death programme in target cells by activating the canonical WNT pathway. We show in mice that macrophage WNT7b is a short-range paracrine signal required for WNT-pathway responses and programmed cell death in the vascular endothelial cells of the temporary hyaloid vessels of the developing eye. These findings indicate that macrophages can use WNT ligands to influence cell-fate decisions--including cell death--in adjacent cells, and raise the possibility that they do so in many different cellular contexts.

Analysis and optimization of nutritional set-up for murine pancreatic acinar cells.

CONTEXT: Pancreatic acinar cell cultivation poses a serious problem due to limitations in the in vitro survival time despite variations of dissociation protocols, culture media and nutrient supplements. OBJECTIVE: To establish a long term culture of murine pancreatic acinar cells which retain their viability, monolayer formation and responsiveness to secretagogues. In order to investigate the mechanism of the short-life of acinar cells studied in vitro, we studied their survival under the influence of different supplements on nutrient media. INTERVENTIONS: Dissociated pancreatic acini were prepared from BALB/c mice pancreata by collagenase digestion supplemented with bovine serum albumin fraction V and soybean trypsin inhibitor. A nutrient set-up was designed for their long term survival in vitro. RESULTS: It was observed that mouse pancreatic acinar cells dissociated in presence of bovine serum albumin fraction V and soybean trypsin inhibitor result in 95% viability. Further cultivation of these acinar cells in Waymouth's MB 752/1 medium supplemented with 10% fetal calf serum (v/v), soybean trypsin inhibitor, bovine serum albumin, dexamethasone, and epidermal growth factor results in their survival for more than 6 days in culture with 85% viability, retention of the secretagogue responsiveness and formation of a monolayer without any extracellular matrix coating. CONCLUSIONS: Our study clearly demonstrates that the addition of soybean trypsin inhibitor to culture medium reduces zymogen granule fragility and acinar cell death, thus increasing their viability for sufficiently long periods. The present study offers an excellent, in vitro model for the investigation of exocrine dysfunction in response to acinar cell injury.