جستجوی مقالات مرتبط با کلیدواژه "remyelination" در نشریات گروه "پزشکی"

Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system characterized by infiltration of inflammatory leukocytes to the CNS followed by oligodendrocyte cell death, myelin sheath destruction, and axonal injury. A logical incidence occurring after demyelination is remyelination. G-protein coupled receptors (GPCRs) activate internal signal transduction cascades through binding to different ligands. This family of receptors are targeted by more than 40% of currently marketed drugs. GPCRs can be successfully targeted for induction of remyelination. GPCRs highly enriched in oligodendrocyte progenitor cells compared to oligodendrocytes are proposed to hamper oligodendrocyte differentiation and therefore their inhibition might induce remyelination. This study aimed to investigate the expression of GPCRs in silico and in vitro.

We performed gene expression analysis using DAVID and Panther websites on a RNA-seq dataset (GSE52564 accession number). Primary embryonic neural stem/progenitor cell isolation and culture were performed and subsequently NSPCs were characterized by Immunocytochemistry with Anti-Nestin antibody. Expression of GPR37L1, EDNRB, PDGFRα, CNPase and GFAP were assessed using real-time PCR. All the experiments were conducted at Shiraz University of Medical Sciences (SUMS), Shiraz, Iran, in the year 2018.

The 14 most highly expressed GPCRs in oligodendrocyte progenitor cells (OPCs) compared to Oligodendrocytes were presented in our study.

The investigation of the most highly expressed GPCRs in OPCs compared to oligodendrocyte in silico and in vitro presents the significant role of GPCRs in remyelination induction. Among the 14 GPCRs mentioned in this study, GPR37L1 is a potential remyelinating drug target and is suggested for further studies.

Semaphorin 3A (Sema 3A) is a secreted protein, which plays an integral part in developing the nervous system. It has collapse activity on the growth cone of dorsal root ganglia. After the development of the nervous system, Sema 3A expression decreases. Neuropilin 1 is a membrane receptor of Sema 3A. When semaphorin binds to neuropilin 1, the recruitment of oligodendrocyte precursor cells to the demyelinated site decreases. In Multiple Sclerosis (MS), Sema 3A expression increases and inhibits oligodendrocyte precursor cell differentiation. Therefore, the remyelination of axons gets impaired. We hypothesized that the function of Sema 3A could be inhibited by neutralizing its binding to membrane NRP1. 

we cloned a soluble form of mouse Neuropilin 1 (msNRP1) in a lentiviral vector and expressed the recombinant protein in HEK293T cells. Then, the conditioned medium of the transduced cells was used to evaluate the effects of the msNRP1 on the inhibition of Sema 3A-induced growth cone collapse activity. Dorsal root ganglion explants of timed pregnant (E13) mice were prepared. Then, the growth cone collapse activity of Sema 3A was assessed in the presence and absence of msNRP1-containing conditioned media of transduced and non-transduced HEK293T cells. Comparisons between groups were performed by 1-way ANOVA and post hoc Tukey tests.

msNRP1 was successfully cloned and transduced in HEK293T cells. The supernatant of transduced cells was concentrated and evaluated for the production of msNRP1. ELISA results indicated that transduced cells secreted msNRP1. Growth cone collapse assay showed that Sema 3A activity was significantly reduced in the presence of the conditioned medium of msNRP1-transduced HEK293T cells. Conversely, a conditioned medium of non-transduced HEK293T cells could not effectively prevent Sema 3A growth cone collapse activity.

Our results indicated that msNRP1 was successfully produced in HEK293T cells. The secreted msNRP1 effectively prevented Sema 3A collapse activity. Therefore, msNRP1 can increase remyelination in MS lesions, although more studies using animal models are required.