ABSTRACT
This study is an attempt to examine the transdifferentiation of bone marrow stromal cells [BMSCs] into tyrosine hydroxylase immunoreactive cells in parkinsonian rats associated with angiogenesis. In this study, Sprague-Dawley rats received unilateral stereotaxic injections of 6-hydroxydopamine[6-OHDA] into the left corpus striatum and then were divided into two groups. One group, the negative control, received only medium while the other group was treated with BMSCs. BMSCs were harvested from femur bones, labeled with bromodeoxyuridine [BrdU] and then transplanted into parkinsonian rats, where a behavioral study and immunohistochemistry were used to evaluate the treatment, The results showed statistically significant improvement in rotational behavior. Anti-BrdU antibody showed engraftment of the transplanted cells at the transplantation site. Additionally, double immunolabeling confirmed that these cells were positive for neurofilament-200 and tyrosine hydroxylase [TH]. It may be concluded that BMSCs transplants could engraft and differentiate into TH immunoreactive cells which may cause recovery from motor deficits. Also, BMSCs may contribute to angiogenesis at the transplantation site
ABSTRACT
Nitric oxide [NO] derived from activated macrophages has been shown to be crucial for the host's leishmanicidal activities. Excess NO, however, can induce apoptosis in some cell types, including macrophages. In the present investigation, we studied the role of NO in inducing apoptosis of BALB / C mice macrophages infected with leishmania major in vitro. The peritoneal macrophages were harvested and cultured with or without L. Major in the presence of a donating reagent [s-Nitroso-N-Acetylpenicillamine [SNAP]] or an inhibitor of NO synthase [NG -Methyl-L-Arginine [NMMA]]. The concentration of NO in culture supernatants was measured after 18 hours incubation. Simultaneously, macrophages undergoing apoptosis were identified by fluorescence and electron microscopy. The results showed an increase in apoptosis rate in parallel to nitrite production in macrophages cultured in the presence of SNAP. Although macrophages infected with L.major had no significant increase in no production, they showed a significant increase in apoptosis rate. Besides, macrophages cultured with NMMA, had a decreased no production but the apoptosis rate increased. Therefore, mechanisms involved in apoptosis induction in the last two groups may be different from NO overproduction