MicroRNA-486-5p inhibits ovarian granulosa cell proliferation and participates in the development of PCOS via targeting MST4.

OBJECTIVE: To explore whether microRNA-486-5p affected the proliferation of ovarian granulosa cells by targeting MST4 (silk/threonine protein kinase 4), thereby promoting the development of polycystic ovary syndrome (PCOS). MATERIALS AND METHODS: The level of microRNA-486-5p in PCOS tissues and adjacent normal tissues was detected by quantitative real-time polymerase chain reaction (qRT-PCR). After microRNA-486-5p up-regulation in KNG cells, the mRNA and protein level of related genes was examined using qRT-PCR and western blot assay, respectively. Meanwhile, cell proliferation and cell cycle were analyzed by cell counting kit-8 (CCK-8) assay and flow cytometry. After insulin treatment of KNG cells, expressions of microRNA-486-5p and MST4, cell proliferation as well as cell cycle, were detected by qRT-PCR, CCK-8 and flow cytometry, respectively. Furthermore, cell proliferation and cycle situation were examined after simultaneous up-regulation of MST4 and microRNA-486-5p in vitro. RESULTS: MicroRNA-486-5p expression in PCOS tissues was significantly lower than that of normal tissues. In KNG cells, up-regulation of microRNA-486-5p significantly inhibited cell proliferation and cell cycle. The levels of cycle-associated proteins including CDK2 and CCNB1 decreased significantly. The results of dual-luciferase reporter gene assay showed that microRNA-486-5p could bind to MST4. After up-regulating microRNA-486-5p, both the mRNA and protein levels of MST4 decreased remarkably. MST4 expression was found significantly elevated in PCOS tissues as well. After overexpression of MST4, cell proliferation was enhanced, cell cycle was promoted, and expressions of cycle-related proteins increased. After treatment with different concentrations of insulin in KNG cells, the expression level of microRNA-486-5p decreased in a concentration-dependent manner. However, opposite results were observed in MST4 level. Meanwhile, the proliferation ability and cell cycle of insulin-treated cells were significantly enhanced. In addition, the inhibitory effect of microRNA-486-5p on cell proliferation and cell cycle could be partially reversed by simultaneous up-regulation of MST4 and microRNA-486-5p. CONCLUSIONS: MicroRNA-486-5p can bind to MST4 in a targeted manner and inhibit the proliferation of ovarian granulosa cells, thereby inhibiting the development of PCOS.

Dual regulation of glycogen synthase kinase-3beta by the alpha1A-adrenergic receptor.

Catecholamines, acting through adrenergic receptors, play an important role in modulating the effects of insulin on glucose metabolism. Insulin activation of glycogen synthesis is mediated in part by the inhibitory phosphorylation of glycogen synthase kinase-3 (GSK-3). In this study, catecholamine regulation of GSK-3beta was investigated in Rat-1 fibroblasts stably expressing the alpha1A-adrenergic receptor. Treatment of these cells with either insulin or phenylephrine (PE), an alpha1-adrenergic receptor agonist, induced Ser-9 phosphorylation of GSK-3beta and inhibited GSK-3beta activity. Insulin-induced GSK-3beta phosphorylation is mediated by the phosphatidylinositol 3-kinase/Akt signaling pathway. PE treatment does not activate phosphatidylinositol 3-kinase or Akt (Ballou, L. M., Cross, M. E., Huang, S., McReynolds, E. M., Zhang, B. X., and Lin, R. Z. (2000) J. Biol. Chem. 275, 4803-4809), but instead inhibits insulin-induced Akt activation and GSK-3beta phosphorylation. Experiments using protein kinase C (PKC) inhibitors suggest that phorbol ester-sensitive novel PKC and Gö 6983-sensitive atypical PKC isoforms are involved in the PE-induced phosphorylation of GSK-3beta. Indeed, PE treatment of Rat-1 cells increased the activity of atypical PKCzeta, and expression of PKCzeta in COS-7 cells stimulated GSK-3beta Ser-9 phosphorylation. In addition, PE-induced GSK-3beta phosphorylation was reduced in Rat-1 cells treated with a cell-permeable PKCzeta pseudosubstrate peptide inhibitor. These results suggest that the alpha1A-adrenergic receptor regulates GSK-3beta through two signaling pathways. One pathway inhibits insulin-induced GSK-3beta phosphorylation by blocking insulin activation of Akt. The second pathway stimulates Ser-9 phosphorylation of GSK-3beta, probably via PKC.

Viral infections of nonhuman primates.

Approximately 53,000 serologic tests and viral isolation studies were performed on 1,700 nonhuman primate specimens for evidence of past and/or current viral infection. Information, other than the requested test, generally was not provided with the specimen. This lack of information does not permit any attempt at interpretation of results. Requested testing included a large number of diverse viral agents in approximately 40 primate species. The resulting data are in keeping with those of previous studies and offer an insight into the needs of colony management, as well as some general information on the overall frequency of infection with the indicated viruses. Inasmuch as the results represent testing of single specimens, they are not to be construed as "diagnostic," and simply indicate past infection as represented by the presence of antibody in the test animal. Viral isolation results are listed, and the number of positive results versus the number of animals tested emphasizes the limitations of the procedure. Investigations such as these continue to assist in the maintenance of healthy nonhuman primate colonies. This information also supports continued use of nonhuman primates for research in human viral infections and may be helpful in terms of animal selection for use in xenotransplants.

Detection of Ebola-Reston (Filoviridae) virus antibody by dot-immunobinding assay.

Thirty human and nonhuman primate sera tested at the Centers for Disease Control by enzyme-linked immunosorbent assay (ELISA), immunofluorescent antibody assay (IFA), and Western blotting were retested at the Virus Reference Laboratory, Inc. by the dot-immunobinding assay (DIA). The Ebola-Reston strain of virus received from the Centers for Disease Control was prepared into a suitable DIA antigen as described for other antigens. All six Western blotting-positive sera were also positive by DIA, as were the five ELISA-positive sera. Testing by IFA, the original test of choice, indicated an additional four seropositives, all negative by the other test systems. Of 288 randomly selected macaque sera, 19 were also found to be Ebola-Reston virus-positive by DIA.

[Specific binding and internalization of anti-CCT2 monoclonal antibody and bleomycin A6 conjugate in human leukemia cells].

The immunoconjugate of anti-CCT2 monoclonal antibody linked to bleomycin A6 was adsorbed on colloidal gold particles (McAb-A6-Au). Binding and internalization of McAb-A6-Au particles in human leukemia CEM cells were examined by electron microscopy. After 60 min at 4 degrees C, McAb-A6-Au particles were bound to the surface membrane of 78% of CEM cells. Transferring to 37 degrees C for 15 min, McAb-A6-Au particles were found to be 56% inside the CEM cells and about one third of the cells contained particles in the nucleus. After 4 h at 37 degrees C the percentage of CEM cells containing McAb-A6-Au particles increased to 72%. However, only 14% of the antigenically irrelevant U937 cells contained these particles and none of them was found in the nucleus. Preincubation with unconjugated anti-CCT2 monoclonal antibody markedly blocked the McAb-A6-Au particle uptake in CEM cells. The McAb-A6-Au particles were internalized through the formation of endocytotic vesicles. In addition, some McAb-A6-Au particles were able to penetrate the plasma membrane directly into cytoplasma and notably into the nucleus. Results indicate that the immunoconjugate of monoclonal antibody linked to bleomycin A6 showed selective binding to target cells and entered the cells specifically and rapidly.

Herpes simplex virus latency in the rabbit trigeminal ganglia: ganglionic superinfection.

It has been confirmed and further documented that infection of the rabbit cornea with the E-43 strain of HSV-1 precludes superinfection of the corresponding trigeminal ganglia by another HSV strain, i.e., the challenging virus does not establish latency and can not be recovered from the ganglia. It was shown that after primary infection, a state of resistance is established in the neuronal cells of the ganglia, and although the challenging strain reaches the ganglia, it does not cause discernible acute infection, and does not displace the resident virus in the ganglia. This protection was present 6 months after primary infection, was independent of immune factors such as circulating or secretory antibodies, and was localized to the point of entry of the primary infecting strain and the sensory neurons that innervate that site. The smallest inoculum that provided protection from ganglionic superinfection was that which produced overt disease in the eye, although different degrees of disease resulted from varying inocula above this minimum. Asymptomatic primary infections produced by subminimal inocula of the E-43 strain or by the HSV recombinant strain, F(MP)F, which is avirulent for the rabbit eye, protected against severe disease and death, but the degree of protection against ganglionic superinfection was variable and depended on the time of challenge. These findings suggest that susceptible neurons in the trigeminal ganglion, when "occupied" by an infecting strain, cannot be superinfected by a second strain.