miR-92a-3p and miR-25-3p Sponges Up-regulate Kiss1 and Affect the Onset of Puberty and Estrous Cycle of Female Mice / 中国生物化学与分子生物学报

Kisspeptin, the neuropeptide produced by Kiss1 neurons in the hypothalamus, is involved in the neuroendocrine regulation of puberty initiation, reproductive system maturation, ovulation and other processes by influencing the secretion of gonadotropin-releasing hormone. Kiss1 gene expression is regulated by multiple trans-regulatory factors and epigenetics. Prediction and preliminary experiments have shown that the seed sequences of miR-92a-3p and miR-25-3p can directly bind to the 3′-UTR of Kiss1 and inhibit the expression of Kiss1. In order to further study the role of miR-92a-3p and miR-25-3p in the regulation of Kiss1, specific absorptive sponge vectors (sponge-miR-92a and sponge-miR-25) with inhibitory effects on miR-92a-3p and miR-25-3p were constructed to realize the functional loss of miRNA. Flow cytometry and dual luciferase reporter assays both confirmed that both sponge vectors could adsorb exogenous or endogenous target miRNAs very effectively. The sponge-miR-92a and sponge-miR-25 vectors are further packaged into the lentivirus LV-sponge-miR-92a and LV-sponge-miR-25. The results of real-time fluorescence quantitative PCR showed that the expression level of Kiss1 in the hypothalamic primary neurons infected by LV-sponge-miR-92a and LV-sponge-miR-25 was significantly up-regulated (P < 0. 05). After injecting LV-sponge-miR-92a into the hypothalamus, the time of female mouse vulva opening was significantly earlier (P<0. 05). The normal oestrus cycle of female mice with was disrupted by injections of LV-sponge-miR-92a and LV-sponge-miR-25 in the hypothalamus. In conclusion, we successfully constructed sponge vectors capable of effectively adsorbing miR-92a-3p and miR-25-3p, and demonstrated their role in removing the inhibition of miR-92a-3p and miR-25-3p on Kiss1. Hypothalamic sponge injection had a certain effect on both the time of vulva opening and the estrus cycle of female mice, suggesting that miR-92a-3p and miR-25-3p may play an important role in the initiation of puberty and reproductive maturity.

Inhibitory effects of neferine on Nav1.5 channels expressed in HEK293 cells / 华中科技大学学报（医学）（英德文版）

Neferine, a bisbenzylisoquinoline alkaloid in Lotus Plumule, was proved to have a wide range of biological activities. In the present study, using whole-cell patch-clamp technique, we investigated the effects of neferine on Nav1.5 channels that are stably expressed in HEK 293 cells. We found that neferine potently and reversibly inhibited Nav1.5 currents in a concentration dependent manner with a half-maximal inhibition (IC50) being 26.15 μmol/L. The inhibitory effects of neferine on Nav1.5 currents were weaker than those of quinidine at the same concentration. The steady-state inactivation curve was significantly shifted towards hyperpolarizing direction in the presence of 30 μmol/L neferine, while the voltage-dependent activation was unaltered. Neferine prolonged the time to peak of activation, increased the inactivation time constants of Nav1.5 currents and markedly slowed the recovery from inactivation. The inhibitory effect of neferine could be potentiated in a frequency-dependent manner. These results suggested that neferine can block Nav1.5 channels under the open state and inactivating state and it is an open channel blocker of Nav1.5 channels.

Na (+) /Ca (2+) Exchanger 3 is Downregulated in the Hippocampus and Cerebrocortex of Rats with Hyperthermia-induced Convulsion / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Na + /Ca 2+ exchanger (NCX) plays a crucial role in pentylenetetrazol-induced convulsion. However, it is unclear whether NCX is critically involved in hyperthermia-induced convulsion. In this study, we examined the potential changes in NCX3 in the hippocampus and cerebrocortex of rats with hyperthermia-induced convulsion.</p><p><b>METHODS</b>Twenty-one Sprague Dawley rats were randomly assigned to control group, convulsion-prone group and convulsion-resistant group (n = 7 in each group). Whole-cell patch-clamp method was used to record NCX currents. Both the Western blotting analysis and immunofluorescence labeling techniques were used to examine the expression of NCX3.</p><p><b>RESULTS</b>NCX currents were decreased in rats after febrile convulsion. Compared to the control group, NCX3 expression was decreased by about 40% and 50% in the hippocampus and cerebrocortex of convulsion-prone rats, respectively. Furthermore, the extent of reduction in NCX3 expression seemed to correlate with the number of seizures.</p><p><b>CONCLUSIONS</b>There is a significant reduction in NCX3 expression in rats with febrile convulsions. Our findings also indicate a potential link between NCX3 expression, febrile convulsion in early childhood, and adult onset of epilepsy.</p>

Effects of isoliensinine on proliferation of porcine coronary arterial smooth muscle cells induced by phenylephrine / 药学学报

<p><b>AIM</b>To investigate the inhibitory effects and mechanism of action of isoliensinine (IL) on the proliferation of porcine coronary arterial smooth muscle cells (CASMCs) induced by phenylephrine (Phen) and its mechanisms of action.</p><p><b>METHODS</b>MTT assay, immunohistochemical method and Western blotting were adopted.</p><p><b>RESULTS</b>IL (0.03 - 3 micromol x L(-1)) could inhibit the CASMCs proliferation induced by Phen (0.1 micromol x L(-1)) in a concentration-dependent manner. IL (0.1 micromol x L(-1)) antagonized Phen-induced overexpression of PDGF-beta and bFGF from 0.545 +/- 0.026 and 0.47 +/- 0.03 to 0.458 +/- 0.019 and 0.376 +/- 0.017 (P < 0.01 , P < 0.01). IL (0.1 micromol x L(-1)) also decreased c-fos, c-myc and hsp70 overexpression induced by Phen from 0.57 +/- 0.04, 0.44 +/- 0.04 and (173 +/- 36)% to 0.46 +/- 0.05, 0.372 +/- 0.021 and (115 +/- 35)% respectively (P < 0.01, P < 0.01, P < 0.01).</p><p><b>CONCLUSION</b>IL exerted antiproliferative effect on CASMCs induced by phenylephrine, and its mechanisms were related to decrease the overexpression of growth factors (PDGF-beta, bFGF), protooncogene (c-fos, c-myc) and hsp70.</p>