Rosiglitazone improves learning and memory impairment of 3 x Tg mice / 药学学报

This study is to investigate the protective effect of rosiglitazone (RSG) against learning and memory impairment of APP/PS1/tau transgenic mice. AD mice model was replicated by using 6-month APP/PS1/tau transgenic mice. The learning and memory ability of mice was evaluated by Morris water maze and Western blotting assays was applied to measure the phosphorylation and O-glycosylation of Tau and neurofilaments (NFs) protein. The results demonstrated that RSG could reverse the learning and memory deficits of 3 x Tg mice significantly. It was also found that RSG could suppress the hyperphosphorylation of Tau and NFs protein levels and increase the glycosylation expression of Tau and NFs proteins in 3 x Tg mice brain. Together, RSG ameliorates cognitive impairments of 3 x Tg mice via the alleviation of the hyperphosphorylated Tau and NFs proteins burden in the brain.

Promoting effect of Chlamydia pneumoniae infection on human laryngeal carcinoma HEp-2 cell adhesion and migration / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the effect of Chlamydia pneumoniae (C.pn) infection on human laryngeal carcinoma cell line HEp-2 cell adhesion and migration, to further clarify the role and mechanism of C.pn infection in tumor metastasis.</p><p><b>METHODS</b>HEp-2 cells were infected with C.pn after the culture and propagation of C.pn. The cytopathic effect was observed by microscopy. Morphological characteristics of C.pn inclusions in HEp-2 cells were examined by fluorescence microscopy and acridine orange staining. The ultrastructural changes of C.pn inclusions in the HEp-2 cells were examined by transmission electron microscopy (TEM). Cell adhesion assay was performed to investigate the effect of C.pn infection on the adhesion of HEp-2 cells to collagen I. Wound-healing assay and transwell assay were performed to explore the effect of C.pn infection on HEp-2 cell migration.</p><p><b>RESULTS</b>At 72 h post-infection, C.pn infected-HEp-2 cells were swollen and partially desquamated. Numerous vacuoles (inclusions) were observed and C.pn inclusions occupied almost the whole cytoplasm of the HEp-2 cells. Grape-like C.pn inclusions were observed in the HEp-2 cells stained with acridine orange under a fluorescence microscope at 72 h after infection. Under TEM, there were more mature pear-shaped elementary bodies, but less larger and round reticulate bodies in the HEp-2 cells infected with C.pn for 72 h. In the cell adhesion assay, the A value in C.pn infection group was 0.669 ± 0.011, significantly higher than that in the control group (0.558 ± 0.005) at 2 h after infection (P < 0.001). The cell adhesion ratio in the C.pn infection group was 119.89%. The migration distance of C.pn infected-HEp-2 cells in the wound-healing assay was significantly longer than that of control cells at 24 h after infection (P < 0.05). HEp-2 cells infected with C.pn for 12 h migrated more than the control cells in the transwell assay (23.40 ± 2.41 vs 10.40 ± 1.67) (P < 0.001).</p><p><b>CONCLUSIONS</b>C.pn infection can significantly promote HEp-2 cell adhesion to collagen I and migration of HEp-2 cells, indicating that C.pn infection may play an important role in promoting the metastasis of laryngeal cancer.</p>

Effect of alloxan intraventricular injection on learning and memory abilities of mice / 中华神经医学杂志

Objective To investigate the effect of glucose metabolism alteration induced by alloxan intraventricular injection on learning and memory abilities of mice, and its role in the development of AD. Methods Mice were randomly divided into high-dose alloxan intraventricular injection group (n=7, 4 mg/kg) and low-dose alloxan intraventricular injection group (n=7, 1.5 mg/kg)and control group (n=7, physiological saline); intraventricular injection of alloxan, the O-GLcNAc transferase inhibitor, was performed in the high-dose and low-dose alloxan intraventricular injection groups to interfere the brain glucose metabolism. Morris water maze was used to detect the learning and memory abilities of mice. Western blotting and immunohistochemistry were used to analyze the alterations of phosphorylation and O-Glycosylation of neurofilament in mice brain induced by alloxan intraventricular injection. Results In the located navigation tests, the swimming time and distance to find the platform in the mice of alloxan administration were significantly increased as compared with those in the control group (P＜ 0.05); in space exploration experiments, compared with those in the control mice, the number of crossing the hidden platform was decreased and the initial angle of entry to water was increased in the mice of alloxan administration (P＜0.05). Western blotting and immunohistochemistry displayed that phosphorylation was obviously increased and the O-Glycosylation was significantly reduced in the cytoskletal neurofilament of the mice with alloxan administration as compared with those in the control group (P＜0.05), which was similar to the alteration of neurofilament's modification in AD brain. Conclusion The inventricular injection of alloxan could impair the learning and memory of mice, which might have a relation with the dysregulation of phosphorylation and O-Glycosylation in neurofilament caused by the impaired glucose metabolism, which is similar to the alteration of phosphorylation and O-Glycosylation in neurofilament in AD brain.