This study addresses the potential application of adiponectin gene therapy and exercise in protection against skeletal muscle dysfunction in type 2 diabetes mellitus (T2DM) while focusing on the role of sarco and endoplasmic reticulum Ca(+2) ATPase (SERCA) and Glut4. 50 rats were divided into five groups: control, T2DM, T2DM treated with either adiponectin gene or exercise or a combination of both. Serum glucose, insulin, HOMA index, triglycerides, and cholesterol were measured. Weight gain%, muscle contractile parameters {(peak twitch tension (Pt), peak tetanic tension (PTT), half relaxation time (HRT)}, and gene expression of SERCA, Glut4, and adiponectin were assessed in gastrocnemius muscle. Diabetic rats treated with either adiponectin gene or exercise showed significant reduction in all serum parameters and wt gain%. There was significant elevation in Pt and PTT with shortening in HRT. Furthermore, a significant increase in SERCA, Glut4, and adiponectin gene expression was noticed in both groups. Combination therapy caused marked gene expression of SERCA, GLUT4, and greater improvement in muscle contractility than either of the monotherapies. Skeletal muscle dysfunction in T2DM is mediated via impaired SERCA and Glut 4. Combination therapy offered best protection against muscle dysfunction and provides a novel promising strategy for a complete cure of muscle dysfunction in T2DM.

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Vincristine (VCR) is a potent anticancer drug, but neurotoxicity is one of its most important dose-limiting toxicities. In this study, we investigated the neurotoxic effect of VCR, the possible mechanisms and the role of erythropoietin (EPO) in the protection against VCR-induced neurotoxicity in a rat model. The neurotoxicity of VCR and protective effect of EPO were examined using the tail flick test and by recording electrophysiological characteristics in isolated sciatic nerve. To elucidate the underlying mechanisms, mRNA expression of N-methyl-Daspartate (NMDA) receptor, an index of glutamate excitotoxicity, and calcitonin gene-related peptide (CGRP), an important regulator of vascular tone, were measured in both spinal cord and sciatic nerves using an RT-PCR method. After intraperitoneal injection at a dose of 150 μg/kg three times weekly for five consecutive weeks, VCR significantly decreased the latency of tail withdrawal reflex, the amplitude of maximum compound action potential (MCAP) and chronaxie, and prolonged the duration of action potential (AP) and relative refractory period (RRP), but it had no effect on conduction velocity. VCR increased NMDA receptor expression and decreased CGRP expression. Forty μg/kg of EPO improved all VCR-induced changes, except chronaxie, while a higher dose of 80 μg/kg reversed all parameters and its effect was more prominent on tail flick test latency and NMDA receptor expression. These results suggested that VCR might cause increased nerve excitability and induce a state of glutamate excitotoxicity through enhancing NMDA receptor expression and diminishing CGRP expression, thus resulting in axonal degeneration. EPO had an obvious neuroprotective effect probably through decreasing NMDA receptor expression and increasing CGRP expression both centrally and peripherally.

Alzheimer's disease is a neurodegenerative disorder clinically characterized by cognitive dysfunction and by deposition of amyloid plaques, neurofibrillary tangles in the brain. The study investigated the therapeutic effect of combined mesenchymal stem cells and erythropoietin on Alzheimer's disease. Five groups of mice were used: control group, Alzheimer's disease was induced in four groups by a single intraperitoneal injection of 0.8 mg kg(-1) lipopolysaccharide and divided as follows: Alzheimer's disease group, mesenchymal stem cells treated group by injecting mesenchymal stem cells into the tail vein (2 x 10(6) cells), erythropoietin treated group (40 microg kg(-1) b.wt.) injected intraperitoneally 3 times/week for 5 weeks and mesenchymal stem cells and erythropoietin treated group. Locomotor activity and memory were tested using open field and Y-maze. Histological, histochemical, immunohistochemical studies, morphometric measurements were examined in brain sections of all groups. Choline transferase activity, brain derived neurotrophic factor expression and mitochondrial swellings were assessed in cerebral specimens. Lipopolysaccharide decreased locomotor activity, memory, choline transferase activity and brain derived neurotrophic factor. It increased mitochondrial swelling, apoptotic index and amyloid deposition. Combined mesenchymal stem cells and erythropoietin markedly improved all these parameters. This study proved the effective role of mesenchymal stem cells in relieving Alzheimer's disease symptoms and manifestations; it highlighted the important role of erythropoietin in the treatment of Alzheimer's disease.