Neuroprotective effects of neural stem cells pretreated with neuregulin1ß on PC12 cells exposed to oxygen-glucose deprivation/reoxygenation.

Studies on ischemia/reperfusion (I/R) injury suggest that exogenous neural stem cells (NSCs) are ideal candidates for stem cell therapy reperfusion injury. However, NSCs are difficult to obtain owing to ethical limitations. In addition, the survival, differentiation, and proliferation rates of transplanted exogenous NSCs are low, which limit their clinical application. Our previous study showed that neuregulin1ß (NRG1ß) alleviated cerebral I/R injury in rats. In this study, we aimed to induce human umbilical cord mesenchymal stem cells into NSCs and investigate the improvement effect and mechanism of NSCs pretreated with 10 nM NRG1ß on PC12 cells injured by oxygen-glucose deprivation/reoxygenation (OGD/R). Our results found that 5 and 10 nM NRG1ß promoted the generation and proliferation of NSCs. Co-culture of NSCs and PC12 cells under condition of OGD/R showed that pretreatment of NSCs with NRG1ß improved the level of reactive oxygen species, malondialdehyde, glutathione, superoxide dismutase, nicotinamide adenine dinucleotide phosphate, and nuclear factor erythroid 2-related factor 2 (Nrf2) and mitochondrial damage in injured PC12 cells; these indexes are related to ferroptosis. Research has reported that p53 and solute carrier family 7 member 11 (SLC7A11) play vital roles in ferroptosis caused by cerebral I/R injury. Our data show that the expression of p53 was increased and the level of glutathione peroxidase 4 (GPX4) was decreased after RNA interference-mediated knockdown of SLC7A11 in PC12 cells, but this change was alleviated after co-culturing NSCs with damaged PC12 cells. These findings suggest that NSCs pretreated with NRG1ß exhibited neuroprotective effects on PC12 cells subjected to OGD/R through influencing the level of ferroptosis regulated by p53/SLC7A11/GPX4 pathway.

Transplantation of Human Umbilical Cord Mesenchymal Stem Cells-Derived Neural Stem Cells Pretreated with Neuregulin1ß Ameliorate Cerebral Ischemic Reperfusion Injury in Rats.

Ischemic stroke is a common cerebrovascular disease and recovering blood flow as early as possible is essential to reduce ischemic damage and maintain neuronal viability, but the reperfusion process usually causes additional damage to the brain tissue in the ischemic area, namely ischemia reperfusion injury. The accumulated studies have revealed that transplantation of exogenous neural stem cells (NSCs) is an ideal choice for the treatment of ischemia reperfusion injury. At present, the source and efficacy of exogenous NSCs after transplantation is still one of the key issues that need to be resolved. In this study, human umbilical cord mesenchymal stem cells (hUC-MSCs) were obtained and induced into NSCs byadding growth factor and neuregulin1ß (NRG1ß) was introduced during the differentiation process of NSCs. Then, the rat middle cerebral artery occlusion/reperfusion (MCAO/R) models were established, and the therapeutic effects were evaluated among groups treated by NRG1ß, NSCs and NSCs pretreated with 10 nM NRG1ß (NSCs-10 nM NRG1ß) achieved through intra-arterial injection. Our data show that the NSCs-10 nM NRG1ß group significantly improves neurobehavioral function and infarct volume after MCAO/R, as well as cerebral cortical neuron injury, ferroptosis-related indexes and mitochondrial injury. Additionally, NSCs-10 nM NRG1ß intervention may function through regulating the p53/GPX4/SLC7A11 pathway, and reducing the level of ferroptosis in cells, further enhance the neuroprotective effect on injured cells.

Selection and Characterization of a Novel DNA Aptamer, Apt-07S Specific to Hepatocellular Carcinoma Cells.

BACKGROUND: The efficacy of traditional therapeutic methods for liver cancer is unsatisfying because of the poor targeting, and inefficient drug delivery system. A recent study has proven that aptamers, developed through cell-SELEX, could specifically recognize cancer cells and show great potential in the development of a delivery system for anticancer drugs. PURPOSE: To develop a hepatocellular carcinoma specific aptamer using two kinds of hepatocellular carcinoma cell lines, HepG2 and SMMC-7721, as double targets and a normal hepatocyte, L02, as a negative control cell. METHODS: Hepatocellular carcinoma specific aptamer was developed via cell-SELEX. The enrichment of the library was monitored by flow cytometric analysis. The specificity, affinity, and distribution of the candidate aptamer were explored. Further study was carried to assess its potential in drug delivery. RESULTS: The library was enriched after 14 rounds of screening. Candidate aptamer Apt-07S can recognize four kinds of hepatocellular carcinoma cells and show little cell-binding ability to normal cells and four cell lines of different cancer types, revealing a high specificity of Apt-07S. Confocal imaging showed that Apt-07S distributed both on the surface and in the cytoplasm of the two target cells. Moreover, an anti-sense nucleotide to gene Plk1 (ASO-Plk1) was connected at the 3' end of Apt-07S to form an integrated molecule (Apt-07S-ASO-Plk1); the functional analysis indicated that the structure of Apt-07S may help ASO-Plk1 enter the cancer cells. CONCLUSION: The study indicates that Apt-07S can specifically target HCC and may have potential in the delivery of anticancer drugs.

Ginsenoside Rg1 protects against 6-OHDA-induced toxicity in MES23.5 cells via Akt and ERK signaling pathways.

AIM OF THE STUDY: The present study was designed to investigate the neuroprotective effects of ginsenoside Rg1 against 6-hydroxydopamine (6-OHDA)-induced toxicity in MES23.5 cells and their possible mechanisms. MATERIALS AND METHODS: MES23.5 cells were treated with or without Rg1 for 24h before exposure to 6-OHDA. Cell viability was determined by MTS assay. The gene and protein expressions of Bcl-2 were detected by real time RT-PCR and western blotting. Phosphorylation of Akt and ERK1/2 were examined by western blotting. RESULTS: Pretreatment with ginsenoside Rg1 had obvious neuroprotective effects on cell viability against 6-OHDA-induced toxicity. 6-OHDA decreased the gene and protein expressions of Bcl-2. These effects could be reversed by Rg1 pretreatment. Potential cell signaling candidates involved in this neuroprotective effect were examined. 6-OHDA significantly inhibited the phosphorylation of Akt and increased the phosphorylation of ERK1/2 in MES23.5 cells. Pretreatment with ginsenoside Rg1 could increase the Akt phosphorylation and inhibit the ERK1/2 phosphorylation induced by 6-OHDA. Further study revealed that LY294002, an inhibitor of phosphatidylinositol 3-kinase (PI3-K), attenuated the neuroprotective effect of Rg1 on cell viability against 6-OHDA-induced toxicity. CONCLUSIONS: Taken together, our results strongly suggest that ginsenoside Rg1 has neuroprotective effects against 6-OHDA-induced toxicity in MES23.5 cells. Its mechanism includes the up-regulation of Bcl-2 gene expression, the activation of Akt phoshphorylation as well as the inhibition of ERK1/2 phosphorylation induced by 6-OHDA.