Changes in microglia number and Iba1 expression level in the prefrontal cortex of type 1 diabetic mice / 生理学报

The aim of the present study was to observe the activation of microglia in the prefrontal cortex of type 1 diabetes mellitus (T1DM) mice, and the expression of the marker genes of the disease-associated microglia (DAM) associated with neurodegenerative diseases. Sixty healthy adult male C57BL/6J mice were randomly divided into two groups, normal control (CON) group and T1DM group. Streptozocin (STZ) was injected intraperitoneally to induce T1DM mice. The spatial learning and memory function of mice was detected by Morris water maze at the 8th week after the successful model establishment. The number and activation of microglia in the prefrontal cortex of mice were detected by immunofluorescence staining and Western blot. Changes in the mRNA level of several DAM molecular markers were detected by RT-FQ-PCR. The results showed that, compared with CON mice, the fasting blood glucose of T1DM mice increased significantly, while the body weight of T1DM mice decreased remarkably (P < 0.05). The escape latency of water maze in T1DM mice was longer than that in CON mice (P < 0.05). Compared with CON group, the Iba1 protein expression and the number of microglia in prefrontal cortex of T1DM group increased significantly (P < 0.05). In addition, the mRNA levels of several DAM markers in prefrontal cortex of T1DM group were increased significantly (P < 0.05). These results suggest that the microglia are activated and transformed to DAM type in the prefrontal cortex of T1DM mice.

Morphine promotes glioblastoma cell proliferation through activating ERK1/2 signaling pathway / 基础医学与临床

Objective To observe the effect of morphine on the proliferation of glioblastoma T98G and U118MG cells and to explore the possible mechanism. Methods Glioblastoma T98G and U118MG cells were cultured in plates for 24 h and randomly divided into five groups: control (con), morphine 0.1 μmol/L(M1),1.0 μmol/L (M2),10.0 μmol/L (M3) and 100.0 μmol/L (M4). MTS and BrdU methods were used to detect the prolifera-tion of glioblastoma T98G and U118MG cells-treated with morphine for 24 h and 48 h. Western blot analysis was applied for determing the level of p-ERK1/2 and cyclin D1 protein expression.Results Compared with the control group,morphine in M3 and M4 groups significantly promoted the proliferation of T98G and U118MG cells (P<0.05) in a concentration-and time-dependent manner. In addition,the level of ERK1/2 phosphorylation and cyclin D1 protein expression significantly increased in both M3 and M4 groups as compared with those of control group (P<0.05). Conclusions Morphine may promote the proliferation of glioblastoma T98G and U118MG cells through activating the ERK1/2 signaling pathway.

Brain mechanisms of male sexual function / 中华男科学杂志

In this paper, we reviewed the brain imaging studies of male sexual function in recent years from three aspects: the brain mechanism of normal sexual function, the brain mechanism of sexual dysfunction, and the mechanism of drug therapy for sexual dysfunction. Studies show that the development stages of male sexual activities, such as the excitement phase, plateau phase and orgasm phase, are controlled by different neural networks. The mesodiencephalic transition zone may play an important role in the start up of male ejaculation. There are significant differences between sexual dysfunction males and normal males in activation patterns of the brain in sexual arousal. The medial orbitofrontal cortex and inferior frontal gyrus in the abnormal activation pattern are correlated with sexual dysfunction males in sexual arousal. Serum testosterone and morphine are commonly used drugs for male sexual dysfunction, whose mechanisms are to alter the activating levels of the medial orbitofrontal cortex, insula, claustrum and inferior temporal gyrus.

Effect of repetitive hypoxia on MMP-2/9 expression and activation in murine brain / 中国应用生理学杂志

<p><b>AIM</b>To explore the changes of MMP-2/9 protein expression and excitation in brain of repetitive hypoxic mice.</p><p><b>METHODS</b>The biochemistry techniques of SDS-PAGE, Western bolt and Gel Goc Image Analysis System were applied to determine the level of MMP-2 and MMP-9 expression and activation in cortex and hippocampus of mice. The animals were randomly divided into 5 groups: the normal control group (H0), acute hypoxic (H1, hypoxic exposure once), repetitive hypoxic groups (H2-H4, repetitive hypoxia for 2-4 runs respectively).</p><p><b>RESULTS</b>(1) The MMP- 2 expression level was increased first then decreased in hippocampus and the significant decrease was found in H4 group (P < 0.05, n=6), but no significant changes among the 5 groups in cortex. In addition, no activated form of 66 kD MMP-2 had been detected both in hippocampus and cortex. (2) Along with the development of brain hypoxic preconditioning, the level MMP-9 protein expression also increased first then decreased gradually in hippocampus, and the significant changes were found both in H1 and H4 groups (P < 0.05, n=7 for each group). The same trace of changes was also found in the activation of MMP-9 (include 82 and 78 kD forms) in hippocampus, and the significance both in H1 and H4 (P < 0.05, n=7 for each group) were detected. However, there was not any significant change in the level of MMP-9 protein expression or activation to be found in cortex.</p><p><b>CONCLUSION</b>These results suggested that MMP-2 and MMP-9 might play certain role in the development of cerebral hypoxic preconditioning, the different changes of MMP-2/9 protein expression and activation both in cortex and hippocampus might be involved in their selective vulnerability to hypoxia.</p>

Hypoxic preconditioning increase nPKCepsilon membrane translocation in the brain of mice / 中国应用生理学杂志

<p><b>AIM</b>To explore the role of novel protein kinases C (nPKCs) in the development of cerebral hypoxic preconditioning.</p><p><b>METHODS</b>By using the mice model of hypoxic preconditioning, which was established before in our lab, the biochemistry techniques of SDS-PAGE and Western blot were applied to observe the effects of repetitive hypoxic exposure (H0-H4) on nPKCs (nPKCepsilon, delta, eta, mu and theta) membrane translocation in hippocampus and cortex.</p><p><b>RESULTS</b>nPKCepsilon membrane translocation was increased in response to the hypoxic exposure times in the hippocampus (H0: 41.6% +/- 1.4% vs. H1-H4: 46.9% +/- 4.5%, 52.7% +/- 3.9%, 58.8% +/- 2.7% and 61.3% +/- 3.7%) and cortex (H0: 38.4% +/- 4.5% vs. 42.4% +/- 5.0%, 48.7% +/- 6.5%, 55.3% +/- 8.9% and 61.2% +/- 10.2%) of mice, and there were statistic significances among H2, H3 and H4 in hippocampus, and H3 and H4 in cortex respectively (P < 0.01). But for nPKCdelta, eta, mu and theta membrane translocation, there were no any significant changes in hippocampus and cortex of hypoxic preconditioned mice.</p><p><b>CONCLUSION</b>nPKCepsilon may play an important role in the development of cerebral hypoxic preconditioning, but it need more evidence to prove.</p>

Hypoxic preconditioning increases cPKCgamma membrane translocation in murine brain / 生理学报

Cerebral hypoxic preconditioning (CHP), which was induced by repetitive sub-lethal hypoxic insult, is an endogenous protection of neuron against subsequent severe hypoxic injury. Although a number of possible induction pathways have been investigated, such as neuroactive cytokines, activation of glutamate receptors, the ATP-sensitive potassium channel, nitric oxide and oxidative stress, the exact mechanism underlying CHP-induced protection remains unclear. It is interesting that all the above-mentioned mechanisms are involved in the activation of protein kinases C (PKC). Recently we reported that the level of PKCs membrane translocation was significantly increased in the brain of hypoxic preconditioned mice. In order to explore the role of conventional protein kinases C (cPKC) in the development of cerebral hypoxic preconditioning, biochemical techniques of SDS-PAGE and Western bolt were applied to observe the effects of repetitive hypoxic exposure (H1-H4) on the level of cPKCalpha and gamma membrane translocation in the cortex and hippocampus of mice. Experiments were carried out in accordance with the National Institutes of Health guide for the care and use of laboratory animals. The hypoxic preconditioned mice model was adapted with minor modification from our previous report. In brief, healthy adult BALB/C mice weighing 18-20 g of either sex were randomly divided into 5 groups: control group (H0), hypoxic control group (H1, hypoxic exposure once ), hypoxic preconditioned group (H2-H4, repetitive hypoxic exposure for 2-4 times respectively). The first sign of gasping breath was taken as the end of each hypoxic exposure, and then the mice were kept in normal control condition for a 30-min interval to recover before the following hypoxic insult. We found that the level of cPKCgamma membrane translocation was increased significantly (*P<0.05, n=6) with the increase of the hypoxic exposure times in both hippocampus (H0: 100% vs H1 approximately H4: 119.2%+/-7.0% *, 139.3% +/-7.4%*, 134.2% +/-8.95%*, 184.0% +/-10.8%*) and cortex (H0: 100% vs H1-H4: 129.7% +/-13.8%, 143.3% +/-13.9%*, 204.0% +/-12.1%*, 229.5% +/-14.6%*) of mice. But there were no significant changes in cPKCalpha membrane translocation in cortex and hippocampi of hypoxic preconditioned mice. These results suggest that cPKCgamma plays an important role in the development of cerebral hypoxic preconditioning. The changes in some other forms of novel and atypical PKCs are still under investigation.