The Effects of Adipose-Derived Mesenchymal Stem Cells and Adipose-Derived Mesenchymal Stem Cell-Originating Exosomes on Nerve Allograft Regeneration: An Experimental Study in Rats.

INTRODUCTION: Nerve regeneration has been the subject of many studies because of its complex mechanism and functional outcome. Mesenchymal stem cells and exosomes are promising factors in regeneration in many areas. Reconstruction of nerve defects is a controversial issue, and nerve allografts are promising alternatives with many advantages. In this study, it is aimed to evaluate the nerve regeneration in cellularized and decellularized nerve allografts and whether it is possible to accelerate this process with adipose-derived mesenchymal stem cells (ad MSC) or ad MSC-originating exosomes. METHOD: This study was performed with 36 Lewis and 18 Brown Norway isogenic male rats aged 10 to 12 weeks and weighing 300 to 350 g. The Lewis rats were divided into 6 groups. Nerve allografts at a length of 12 mm that were obtained from the Brown Norway rats' proximal portion of both sciatic nerve branching points were coapted as cellularized in group A and decellularized in group B to the sciatic nerve defects of the Lewis rats. Group A received oral tacrolimus (0.2 mg/kg) for 30 days. Perineural saline (A1-B1), ad MSC (A2-B2), or ad MSC-originating exosomes (A3-B3) were applied to these groups. Walking track analysis, pinch-prick test and electromyelography were applied at the 8th and 16th weeks following surgery. Nerves were examined histopathologically at the 16th week. RESULTS: Between cellularized groups, better results were shown in A3 about axon-myelin regeneration/organization (P = 0.001), endoneural connective tissue (P = 0.005), and inflammation (P = 0.004). Better results were shown in the B2 and B3 groups electromyelographicaly about latency period (P = 0.033) and action potential (P = 0.008) at late period, and histomorphologicaly at vascularization (P = 0.012). DISCUSSION: It is argued that regeneration is accelerated with decellularization of nerve allografts by removing the chondroidin sulfate proteoglycans. The positive effects of stem cells are derived by exosomes without the cell-related disadvantages. In this study, better results were obtained by decellularization and perineural application of ad MSC and/or ad MSC exosome.

Autologous transplantation of arterial cells improves cardiac function in a rabbit model of infarcted myocardium.

Cellular cardiomyoplasty is a promising approach for the treatment of severe heart failure. However, the question which cell line is the best to use is still a matter of debate. In this study, we aimed to evaluate the efficacy of arterial media-intima cell suspension (AMICS) transplantation in rabbit myocardial infarct model. The study was divided into 2 groups: group A (the cell-treated group, n = 9) and group B (the medium injection group, n = 8). Group A was further divided into 2 subgroups as branch-1 (treated with unlabeled cells) and branch-2 (treated with iron-labeled cells). The experimental myocardial infarction (MI) was induced by ligation of left anterior descending coronary artery with a combination of cryoinjury. Ten days after the MI, cells obtained from autologous femoral arteries were injected into the injured myocardium of group A, while group B received an injection of only DMEM medium. Clinical, echocardiographic, and histopathologic evaluations were done. As compared to the ninth day values, echocardiography showed a significant improvement in systolic functions and left ventricular (LV) dimensions of the cell-treated group on the 30th day. In the heart biopsy sections of branch-1, the immunostained injected cells were observed to exist closely, suggesting an organization. Cells existing separately and lumen-like structure organizations stained positive with both smooth muscle cell (SMC) alpha-actin and Prussian Blue were also showed in the histological observation of branch-2. Autologous AMICS transplantation seems to be a feasible and efficacious method for cellular cardiomyoplasty in our rabbit model.

Improvement in rabbit corneal cell suspension viability after freezing with Gingko Biloba extract.

We investigated whether the addition of Gingko Biloba extract (EGb 761) to rabbit corneal epithelial medium before cell freezing improved cell viability after freezing then thawing. After removal of corneas, they were treated with enzymes and the corneal epithelium was prepared as a single cell suspension in freezing media with or without EGb 761. After freezing for two weeks then thawing, a higher cell viability was found in the cornea cell suspensions which had been frozen pretreated with EGb 761 in the media. The improvement with corneal cell viability with EGb 761 pretreatment is postulated to be based on the antioxidant capacity of the plant extract.

Improvement In Rabbit Corneal Cell Suspension Viability After Freezing With Gingko Biloba Extrakt.

We investigated whether the addition of Gingko Biloba extract (EGb 761) to rabbit corneal epithelial medium before cell freezing improved cell viability after freezing then thawing. After removal of corneas, they were treated with enzymes and the corneal epithelium was prepared as a single cell suspension in freezing media with or without EGb 761. After freezing for two weeks then thawing, a higher cell viability was found in the cornea cell suspensions which had been frozen pretreated with EGb 761 in the media. The improvement with corneal cell viability with EGb 761 pretreatment is postulated to be based on the antioxidant capacity of the plant extract.

The role of inflammation markers in triggering acute coronary events.

Studies have shown disparate results in relation to the role of plasma concentrations of inflammation markers such as fibrinogen, cytokines, and cell adhesion molecules in acute coronary syndromes. The differentiation of primary versus secondary alterations of these markers in response to acute coronary syndromes is not clear. The aim of this study was to investigate the effect of soluble cell adhesion molecules and some inflammatory markers on coronary plaque instability. The prospective study consisted of 15 patients with stable angina pectoris (SAP), 16 with unstable angina pectoris (UAP), and 16 who had undergone percutaneous transluminal coronary angioplasty (PTCA). Blood samples were obtained from the SAP group on admission, from the UAP group at the early stage of pain onset within 6 h of pain, and again after 12 h of pain. Samples from the PTCA group were collected before, 2, 14 h after the procedure. Soluble vascular cell adhesion molecule-1 (VCAM-1), endothelial selectin, interleukin-1 beta (IL-1 beta) and interleukin-2 (IL-2), and C-reactive protein (CRP) were analyzed by enzyme-linked immunosorbent assay. CRP serum levels gradually increased although IL-2 gradually decreased in patients with UAP and PTCA. In addition, VCAM-1 levels were sharply decreased after the PTCA procedure. However, this value returned back to the preprocedure levels 14 h after PTCA. Both CRP and IL-2 are directly involved in the triggering mechanisms of acute coronary events.