October 1, 2017.
Diabetes is a chronic disease that affects more than 30 million Americans. This disorder leads to a variety of acute and chronic complications, including diabetic ulcers (chronic wounds). Chronic wounds often persist due to poor regeneration of the blood supply which is essential to bring nutrients for healing. Particularly, diabetic individuals are prone to damage in their peripheral tissues which leads to a high prevalence of ulcers in their extremities, often leading to limb amputations. The aim of this study is to improve healing outcomes for diabetics through the use of mesenchymal stem cells (MSCs) to stimulate healing, in which vasculogenesis is an important aspect. Catecholamines such as epinephrine (adrenaline) are prevalent in diabetic foot ulcer tissue and have been shown to inhibit wound healing. In this study, healing rates of type II diabetic mice wounds were evaluated when human MSCs were delivered within a collagen scaffold (IntegraTM) and treated with Timolol, a beta blocker that inhibits the effects of epinephrine. We examined wounded mice after 7 days that had received either no MSCs (control), MSCs, or MSCs treated with timolol for blood vessel development using immunohistochemical staining and confocal fluorescence microscopy. Blood vessel biomarkers GSL-I Isolectin B4 and CD31 were used to stain the wound tissue and fluorescent imaging data was quantified using software. Our results indicate that wound tissue treated with MSCs and timolol had the highest blood vessel regeneration and it was statistically significant when compared to control levels. Additionally, a Fluorescent in situ Hybridization (FISH) protocol to identify human chromosomes was successfully implemented using positive and negative control slides so that human MSCs can be identified when delivered to mouse wound tissue. Future experiments will examine how long the MSCs persist and whether they migrate outside the wound tissue bed.
California State University, Sacramento (Sac State)
This material is based upon work supported by the National Science Foundation through the Robert Noyce Teacher Scholarship Program under Grant # 1136419. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. The research was also made possible by the California State University STEM Teacher and Researcher Program, in partnership with Chevron (www.chevron.com), the National Marine Sanctuary Foundation (www.marinesanctuary.org) and Sacramento State University.