Regeneration of blood vessels within diabetic wounds after treatment with mesenchymal stem cells

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

Latency to paroxetine-induced anxiolysis in the rat is reduced by co-administration of the 5-HT(1A) receptor antagonist WAY100635

1. We report here the use of rat high-light social interaction to model the temporal anxiolytic/antidepressant effects of SSRIs seen in the clinic. Compared to vehicle controls, 21, but not 14, days of paroxetine treatment (3 mg kg(−1), p.o., daily) produced a marked increase in rat social interaction (Vehicle=71.3±7.3 s; Paroxetine=116.7±14.7 s; P<0.01) with no concurrent effect on locomotor activity, consistent with anxiolysis. 2. To assess whether concurrent 5-HT(1A) receptor blockade reduces the time to onset of anxiolysis seen with paroxetine alone (21 days), rats were implanted with osmotic minipumps to continuously infuse the 5-HT(1A) receptor antagonist WAY100635 (1 mg kg(−1) day(−1), s.c., 7 days) alone or in combination with paroxetine (3 mg kg(−1), p.o., daily, 7 days), prior to anxiety testing. Paroxetine (Veh/Par=61.9±7.9 s) or WAY100635 (WAY/Veh=71.6±4.7 s) alone, had no effect on social interaction time compared to vehicle treated controls (Veh/Veh=76.4±4.9 s), whilst coadministration of WAY100635 with paroxetine, produced a marked elevation in social interaction (WAY/Par=149.3±16.8 s; P<0.01) relative to all other groups with no concurrent change in locomotor activity. 3. In contrast, acute administration of WAY100635 (0.03 mg kg(−1), s.c.) with paroxetine (3 mg kg(−1), p.o.) did not alter any behavioural measure, suggesting that the anxiolysis induced by the combination after 7 days is attributable to a CNS adaptive response. 4. This data demonstrates that coadministration of a 5-HT(1A) receptor antagonist with paroxetine markedly reduces the latency to anxiolysis, in the rat. 5. This study supports the use of the rat social interaction test to further delineate adaptive changes in the CNS responsible for the anxiolytic/antidepressant action of SSRIs seen in humans