Transplantation of adipose-derived mesenchymal stem cells (ASCs) induces tissue regeneration by accelerating the growth of blood vessels and nerve. However, mechanisms by which they accelerate the growth of nerve fibers are only partially understood. We used transplantation of ASCs with subcutaneous matrigel implants (well-known in vivo model of angiogenesis) and model of mice limb reinnervation to check the influence of ASC on nerve growth. Here we show that ASCs stimulate the regeneration of nerves in innervated mice's limbs and induce axon growth in subcutaneous matrigel implants. To investigate the mechanism of this action we analyzed different properties of these cells and showed that they express numerous genes of neurotrophins and extracellular matrix proteins required for the nerve growth and myelination. Induction of neural differentiation of ASCs enhances production of brain-derived neurotrophic factor (BDNF) as well as ability of these cells to induce nerve fiber growth. BDNF neutralizing antibodies abrogated the stimulatory effects of ASCs on the growth of nerve sprouts. These data suggest that ASCs induce nerve repair and growth via BDNF production. This stimulatory effect can be further enhanced by culturing the cells in neural differentiation medium prior to transplantation.
Background: A number of epidemiological studies have established a link between insulin resistance and the prevalence of depression. The occurrence of depression was found to precede the onset of diabetes and was hypothesized to be associated with inherited inter-related insufficiency of the peripheral and central insulin receptors. Recently, dicholine succinate, a sensitizer of the neuronal insulin receptor, was shown to stimulate insulin-dependent H2O2production of the mitochondrial respiratory chain leading to an enhancement of insulin receptor autophosphorylation in neurons. As such, this mechanism can be a novel target for the elevation of insulin signaling.Results: Administration of DS (25 mg/kg/day, intraperitoneal) in CD1 mice for 7 days prior to the onset of stress procedure, diminished manifestations of anhedonia defined in a sucrose test and behavioral despair in the forced swim test. Treatment with dicholine succinate reduced the anxiety scores of stressed mice in the dark/light box paradigm, precluded stress-induced decreases of long-term contextual memory in the step-down avoidance test and hippocampal gene expression of IGF2.Conclusions: Our data suggest that dicholine succinate has an antidepressant-like effect, which might be mediated via the up-regulation of hippocampal expression of IGF2, and implicate the neuronal insulin receptor in the pathogenesis of stress-induced depressive syndrome.
The effect of substances known as inducers of neuronal differentiation on cultured human and mouse adipose-derived mesenchymal stem cells (ASCs) and their fate after transplantation into the injured and ischemic mouse brains were studied. ASCs were isolated from the human and mouse adipose tissue. Inducers of neuronal differentiation included β-mercaptoethanol, glial cell line-derived neurotrophic factor (GNDF), brain-derived neurotrophic factor (BDNF), retinoic acid (RA), 5-azacytidine, as well as their combinations. Three days after the induction, the phenotype of the induced cells was analyzed using immunocytochemistry and real-time PCR assay for differential expression of specific genes. The induction efficiency was evaluated by the increased transcription of neuronal differentiation markers: nestin, β-III-tubulin (Tub-B), microtubule-associated protein 2 (MAP2), and neuron-specific enolase (ENO2). The expression of marker genes was tested by immunocytochemical analysis. ASC cultivation in the medium with RA or BDNF in combination with 5- azacytidine for a week increased the mRNA and protein levels of nestin, Tub-B, and ENO2. The transplantation of induced mouse ASCs into the mouse brain increased the lifespan of the cells relative to control uninduced cells and promoted their migration from the transplantation site to the recipient cerebral parenchyma. The transplantation of the induced cells into the mouse brain pre-exposed to endothelin- 1 promoted a more active cell migration into the surrounding ischemic brain tissue. Thus, ASC exposure to RA or BDNF in combination with 5-azacytidine elevated the transcription of the neuronal differentiation markers and improved the viability and integration of ASCs grafted into the mouse brain.
The review presents data which provides evidence for the internal relationship between the stages of rodent audiogenic seizures and post-ictal catalepsy with the general pattern of animal reaction to the dangerous stimuli and/or situation. The wild run stage of audiogenic seizure fit could be regarded as an intense panic reaction, and this view found support in numerous experimental data. The phenomenon of audiogenic epilepsy probably attracted the attention of physiologists as rodents are extremely sensitive to dangerous sound stimuli. The seizure proneness in this group shares common physiological characteristics and depends on animal genotype. This concept could be the new platform for the study of epileptogenesis mechanisms.