MiR-424 Inhibits neuronal apoptosis in rats with cerebral infarction through regulating TGF-ß1/Smad3 signaling pathway.

It has been reported that micro ribonucleic acid (miR)-424 is an important molecule in cerebral ischemia. However, the precise mechanism of action and biological effects of miR-424 remain to be further explored. miR-424 mimic and miR-424 inhibitor were injected via the caudal vein in rats, and the effect of miR-424 expression on brain tissue damage induced by middle cerebral artery occlusion (MCAO) was detected. The miR-424 mimic-induced changes in genomic levels were detected via the gene chip assay, and the signaling pathways regulated by miR-424 and its potential targets were explored combined with target prediction. Then the effect of miR-424 mimic on apoptosis of PC12 cells induced by oxygen-glucose deprivation (OGD) was determined using Annexin V/PI assay. Finally, drosophila mothers against decapentaplegic protein 7 (Smad7) was overexpressed to further verify the mechanism of action of miR-424 mimic. Compared with that in the sham group, the expression of miR-424 in brain tissues significantly declined in the model group. The results of 2,3,5-triphenyltetrazolium chloride (TTC) staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay revealed that the miR-424 mimic obviously reduced the cerebral infarction area and apoptosis level of brain tissues, while the miR-424 inhibitor obviously increased the cerebral infarction area and apoptosis level of brain tissues. It was found, using bioinformatics and KEGG enrichment analysis, that differentially expressed genes induced by miR-424 were significantly enriched in the transforming growth factor-ß (TGF-ß) signaling pathway. According to the results of reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blotting, the miR-424 mimic could evidently lower the expression of Smad7, thus activating the TGF-ß1/Smad3 signaling pathway. Overexpression of Smad7 could weaken the protective effect of miR-424 mimic on ischemic-hypoxic cells. Increasing the expression of miR-424 can inhibit Smad7 to activate the TGF-ß1/Smad3 signaling pathway, thereby exerting a protective effect against the brain tissue damage induced by MCAO.

Molecular characterizations of natalisin and its roles in modulating mating in the oriental fruit fly, Bactrocera dorsalis (Hendel).

Initially, natalisin (NTL) was identified from three holometabolous insect species, Drosophila melanogaster, Tribolium castaneum and Bombyx mori, and was documented to regulate reproductive behaviours in D. melanogaster and T. castaneum. In this study, we report the sequences of the NTL precursor and its receptor (NTLR) from an important agricultural pest, Bactrocera dorsalis (Hendel). NTLR is a typical G-protein coupled receptor and phylogenetic analysis showed that B. dorsalis NTLR was closely related to insect natalisin receptors from other species. A functional assay of NTLR transiently expressed in Chinese hamster ovary cells showed that it was activated by putative natalisin mature peptides in a concentration-dependent manner, with 50% effective concentrations (EC50 ) at nanomolar or micromolar levels. As indicated by quantitative real-time PCR, both NTL and NTLR had the highest expression in the central nervous system of B. dorsalis compared with the other tested tissues. Three pairs of adult brain neurones of B. dorsalis were identified with immunohistochemical antibody staining against D. melanogaster NTL4, and in situ hybridization with specific DNA probes. Moreover, RNA interference mediated by double-stranded RNA injection in adults provided evidence for the important roles of NTL in regulating both male and female mating frequencies in this fly.

[A diagnostic kit for rapid microenzyme linked immunosorbent assay of paragonimiasis].

With a diagnostic kit for paragonimiasis we recently developed, 112 active paragonimiasis cases were examined and 111 (99.1%) of them showed positive reaction. Sera of 100 healthy persons all showed negative reaction, while 2.3% (3/130) of the patients with other parasitic diseases showed a week cross reaction. Sera of 40 cases with non-parasitic pulmonary diseases also showed negative reaction. The reciprocal titre of cases of paragonimiasis in terms of geometrical mean (GMRT) versus that of normal person was 1396 to 21 (P less than 0.0001). The reproduction and stability of this kit was satisfactory and no significant changes were noted when being kept in room temperature for 12 weeks or being treated with heat (37 degrees C 30', 56 degrees C 30', 64 degrees C 30', 100 degrees C 1', 2', 3', in water bath). When the antigen was treated in 100 degrees C water bath for 30', the OD value obtained with positive control serum showed a slight decrease, but OD value of the positive specimen was still 2.1 times higher than that of negative specimen. There was no significant difference whether the antigen was lyophilized or not. When the antigen was purified by sephadex G 100 gel column, the G100-1 portion showed higher antigenic activity and specificity, but it was not as sensitive as the crude antigen.