The imbalance between excess reactive oxygen species (ROS) generation and insufficient antioxidant defenses contribute to a range of neurodegenerative diseases. High ROS levels damage cellular macromolecules such as DNA, proteins and lipids, leading to neuron vulnerability and eventual death. However, the underlying molecular mechanism of the ROS regulation is not fully elucidated. Recently, an increasing number of studies suggest that microRNAs (miRNAs) emerge as the targets in regulating oxidative stress. We recently reported the neuroprotective effect of miR-137-3p for brachial plexus avulsion-induced motoneuron death. The present study is sought to investigate whether miR-137-3p also could protect PC12 cells against hydrogen peroxide (H2O2) induced neurotoxicity. By using cell viability assay, ROS assay, gene and protein expression assay, we found that PC-12 cells exposed to H2O2 exhibited decreased cell viability, increased expression levels of calpain-2 and neuronal nitric oxide synthase (nNOS), whereas a decreased miR-137-3p expression. Importantly, restoring the miR-137-3p levels in H2O2 exposure robustly inhibited the elevated nNOS, calpain-2 and ROS expression levels, which subsequently improved the cell viability. Furthermore, the suppressive effect of miR-137-3p on the elevated ROS level under oxidative stress was considerably blunted when we mutated the binding site of calpain-2 targted by miR-137-3p, suggesting the critical role of calpain-2 involving the neuroprotective effect of miR-137-3p. Collectively, these findings highlight the neuroprotective role of miR-137-3p through down-regulating calpain and NOS activity, suggesting its potential role for combating oxidative stress insults in the neurodegenerative diseases.
Fur seal feces-associated circular DNA virus(FSfa CV) is an unclassified circular replication-associated protein(Rep)-encoding single-stranded(CRESS) DNA virus that has been detected in mammals(fur seals and pigs). The biology and epidemiology of the virus remain largely unknown. To investigate the virus diversity among pigs in Anhui Province,China, we pooled 600 nasal samples in 2017 and detected viruses using viral metagenomic methods. From the assembled contigs, 12 showed notably high nucleotide acid sequence similarities to the genome sequences of FSfa CVs. Based on these sequences, a full-length genome sequence of the virus was then obtained using overlapping PCR and sequencing, and the virus was designated as FSfa CV-CHN(Gen Bank No. MK462122). This virus shared 91.3% and 90.9% genome-wide nucleotide sequence similarities with the New Zealand fur seal strain FSfa CV-as50 and the Japanese pig strain FSfa CVJPN1, respectively. It also clustered with the two previously identified FSfa CVs in a unique branch in the phylogenetic tree based on the open reading frame 2(ORF2), Rep-coding gene, and the genome of the reference CRESS DNA viruses.Further epidemiological investigation using samples collected in 2018 showed that the overall positive rate for the virus was 56.4%(111/197) in Anhui Province. This is the first report of FSfa CVs identified in pigs in China, and further epidemiological studies are warranted to evaluate the influence of the virus on pigs. 相似文献
Virologica Sinica - The sudden emergence of severe acute respiratory syndrome coronavirus (SARS-CoV) has caused global panic in 2003, and the risk of SARS-CoV outbreak still exists. However, no... 相似文献
