Protective Effects of Berberine on Oxygen-Glucose Deprivation/Reperfusion on Oligodendrocyte Cell Line (OLN-93)

Background: Oligodendrocytes, the myelinating glial cells of central nervous system, are highly vulnerable to ischemic-induced excitotoxic insult, a phenomenon in which calcium overload triggers cell death. Berberine is an alkaloid extracted from medicinal herbs as Coptidis Rhizoma with several pharmacological effects like inhibition of neuronal apoptosis in cerebral ischemia. Methods: We examined the effects of berberine (0.5-4 μM) and glutamate receptors antagonists (MK-801 [10 μM] and NBQX [30 μM]) on OLN-93 cell line (a permanent immature rat oligodendrocyte) during (30, 60, 240 min) oxygen-glucose deprivation (OGD)/24 h reperfusion. The cells were cultured in 12-well plates. The cells were exposed to glucose-free medium and hypoxia in a small anaerobic chamber. Cell viability was evaluated by MTT (3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) assay. The intracellular calcium levels also were evaluated by Ca 2+ -sensitive indicator Fura-2/AM in presence or absence of berberine (2 μM) during 30 min chemical OGD by NaN3 (20 mM). Student′s t-test and ANOVA were used for statistical analysis. Results: Berberine, MK-801and NBQX significantly increased oligodendrocyte viability in all 3 time-scheduled oxygen-glucose deprivation/reperfusion. Berberine at 2 μM produced peak of protection, and increased cell viability to 83%, 77%, and 79% during 30, 60, 240 min ischemic experiments, respectively (P < 0.001). Berberine significantly attenuated intracellular Ca 2+ rise induced by chemical ischemia, and this effect of berberine was significantly stronger than MK-801 and NBQX (P < 0.001). Conclusions: We concluded that berberine protected OLN-93 oligodendrocyte against ischemic induced excitotoxic injury. Attenuation of intracellular Ca 2+ overload by berberine may be the key mechanism that saved OLN-93 from excitotoxicity damage

Bulge Cells of Rat Hair Follicles: Isolation, Cultivation, Morphological and Biological Features

Objective: Transplants of multipotent stem cells have been shown to have a neuroprotectiveeffect after central nervous system injury. The bulge region of the hair follicle hasbeen reported as a putative source of hair follicle stem cells (HFSC) for many years;however, few studies have documented the properties of bulge derived cells in vitro untilnow. This study was conducted to isolate and culture bulge cells from rat hair folliclesand to determine the morphological and biological features of the cultured cells.Materials and Methods: The bulge region of the rat whisker was isolated and culturedin Dulbecco's modified eagle medium: nutrient mixture F-12 (DMEM/F12) supplementedwith epidermal growth factor (EGF), cholera toxin. Dissociated bulge stemcells were differentiated on coated substrates together with NT-3. The morphologicaland biological features of cultured bulge cells were observed by light microscopy andimmunocytochemistry methods.Results: Our results showed that newly proliferated cells could be observed on the 4thday after explantation. The expression of a neural progenitor marker, nestin, was seenbefore differentiation of the bulge cells. The differentiated cells expressed βIII-Tubulinand RIP, which are the markers of neural and glial lineages.Conclusion: The results indicated that the bulge cells cultured from the rat hair folliclehad the characteristics of stem cells and could differentiate into neural and glial lineages