Overexpression of hSNF2H in glioma promotes cell proliferation, invasion, and chemoresistance through its interaction with Rsf-1.

hSNF2H partners with Rsf-1 to compose the Rsf complex to regulate gene expression. Recent studies indicated that hSNF2H was overexpressed in several human cancers. However, its expression pattern and biological mechanism in glioma remain unexplored. In this study, we found that hSNF2H was overexpressed in 32 % of glioma specimens. hSNF2H overexpression correlated with advanced tumor grade (p = 0.0338) and Rsf-1 positivity in glioma tissues (p = 0.016). Small interfering RNA (siRNA) knockdown was performed in A172 and U87 cell lines. MTT, colony formation assay, and cell cycle analysis showed that knockdown of hSNF2H inhibited cell proliferation, colony formation ability, and cell cycle transition. Matrigel invasion assay showed that hSNF2H depletion inhibited invasive ability of glioma cells. In addition, we demonstrated that hSNF2H depletion decreased temozolomide resistance of A172 and U87 cell lines and increased temozolomide induced apoptosis. Furthermore, hSNF2H depletion decreased cyclin D1, cyclin E, p-Rb, MMP2, cIAP1, Bcl-2 expression, and phosphorylation of IκBα and p65, suggesting hSNF2H regulates apoptosis through NF-κB pathway. Immunoprecipitation showed that hSNF2H could interact with Rsf-1 in both cell lines. To validate the involvement of Rsf-1, we checked the change of its downstream targets in Rsf-1 depleted cells. In Rsf-1 depleted cells, changes of cyclin E, Bcl-2, and p-IκBα were not significant using hSNF2H siRNA treatment. In conclusion, our study demonstrated that hSNF2H was overexpressed in human gliomas and contributed to glioma proliferation, invasion, and chemoresistance through regulation of cyclin E and NF-κB pathway, which is dependent on its interaction with Rsf-1.

Isoflurane post-conditioning protects primary cultures of cortical neurons against oxygen and glucose deprivation injury via upregulation of Slit2/Robo1.

Different mechanisms have been suggested to contribute to isoflurane-mediated neuroprotection. Previous studies have suggested that the protein Slit can abrogate neuronal death in mixed neuronal-glial cultures exposed to oxygen-glucose deprivation (OGD) and reperfusion (OGD/R). We hypothesized that isoflurane increases the expression of Slit and its receptor Robo when cortical neurons are exposed to OGD/R. To test this hypothesis, we exposed primary cortical neurons to OGD for 90 min and reperfusion for 24h and investigated how isoflurane post-conditioning affected cell survival and expression of Slit2 and receptors Robo1 and Robo4. Cell survival increased after administration of isoflurane, as assessed by the lactate dehydrogenase assay, trypan blue analysis, and propidium iodide staining. Western blot analysis showed that cleaved caspase-3 was increased after OGD/R(P<0.01) but reduced by isoflurane post-conditioning. Real-time PCR and Western blot analysis showed that the expression levels of Slit2 and Robo1, but not Robo4, were increased after OGD/R (P<0.5) and increased even further by isoflurane post-conditioning (P<0.01). Our results suggest that isoflurane post-conditioning markedly attenuates apoptosis and necrosis of cortical neurons exposed to OGD/R possibly in part via elevation of Slit2 and Robo1 expression. These findings provide a novel explanation for the pleiotropic effects of isoflurane that could benefit the central nervous system.

Propofol increases expression of basic fibroblast growth factor after transient cerebral ischemia in rats.

Anesthetics such as propofol can provide neuroprotective effects against cerebral ischemia. However, the underlying mechanism of this beneficial effect is not clear. Therefore, we subjected male Sprague-Dawley rats to 2 h of middle cerebral artery occlusion and investigated how post-ischemic administration of propofol affected neurologic outcome and the expression of basic fibroblast growth factor (bFGF). After 2 h of ischemia, just before reperfusion, the animals were randomly assigned to receive either propofol (20 mg kg(-1) h(-1)) or vehicle (10 % intralipid, 2 ml kg(-1) h(-1)) intravenously for 4 h. Neurologic scores, infarct volume, and brain water content were measured at different time points after reperfusion. mRNA level of bFGF was measured by real-time PCR, and the protein expression level of bFGF was analyzed by immunohistochemistry and Western blot. At 6, 24, 72 h, and 7 days of reperfusion, infarct volume was significantly reduced in the propofol-treated group compared to that in the vehicle-treated group (all P < 0.05). Propofol post-treatment also attenuated brain water content at 24 and 72 h and reduced neurologic deficit score at 72 h and 7 days of reperfusion (all P < 0.05). Additionally, in the peri-infarct area, bFGF mRNA and protein expression were elevated at 6, 24, and 72 h of reperfusion compared to that in the vehicle-treated group (all P < 0.05). These results show that post-ischemic administration of propofol provides neural protection from cerebral ischemia-reperfusion injury. This protection may be related to an early increase in the expression of bFGF.

[The comparison of the vasoactive effects of dopamine on isolated rabbit pulmonary and systemic arteries after incubation with lipopolysaccharide].

OBJECTIVE: To compare the vasoactive effects of dopamine (DOPA) of different concentrations on isolated rabbit pulmonary and systemic arteries after incubation with lipopolysaccharide (LPS). METHODS: Six white male rabbits were used. Thirty-six pulmonary arterial rings and 36 systemic arterial rings were prepared. The 36 pulmonary arterial rings were divided into six groups to determine the effect of different concentrations of DOPA (4x10(-5) , 8x10(-5), 16x10(-5) micromol/L) on the tension of the normal pulmonary artery (PN-DOPA4, PN-DOPA8, PN-DOPA16 groups, respectively), and the tension of the pulmonary artery rings after being incubated with LPS (PL-DOPA4, PL-DOPA8, PL-DOPA16 groups, respectively). The 36 systemic arterial rings were also divided into six groups as the pulmonary arterial rings, including normal groups (SN-DOPA4, SN-DOPA8 , SN-DOPA16) and LPS groups (SL-DOPA4, SL-DOPA8 , SL-DOPA16). RESULTS: (1) DOPA relaxed the arterial rings in PN-DOPA4 and SN-DOPA4 groups, while it produced contraction in PN-DOPA8, PN-DOPA16, SN-DOPA8 and SN-DOPA16 groups, and the contraction was more marked with the increase in concentration of DOPA. (2) After preincubation with LPS, the relaxation property of DOPA in PL-DOPA4 and SL-DOPA4 groups was observed to be reversed to contraction [(22.60+/-6.68)% vs. -(2.25+/-0.58)%, (3.80+/-0.52)% vs. -(3.65+/-0.75)%, P<0.05 and P<0.01]; the contraction response of DOPA in PL-DOPA8 group decreased compared with PN-DOPA8 group by (14.52+/-0.59)% (P<0.05), while increased by (25.90+/-1.75)% in SL-DOPA8 group compared with SN-DOPA8 group (P<0.05), and no response was observed in PL-DOPA16 and SL-DOPA16 groups. (3)After preincubation with LPS, changes in pulmonary arterial tension (PL/PN) in DOPA4 group were more obvious than those in systemic arterial tension (SL/SN, -10.90+/-5.06 vs. -1.00+/-0.24, P<0.05), while the SL/SN in DOPA8 group were more obvious (1.80+/-0.35 vs. 0.48+/-0.17, P<0.01). CONCLUSION: DOPA in low concentrations had the function of relaxation on the pulmonary arterial and systemic arterial rings. After the arterial rings are preincubated with LPS, the relaxation response of DOPA of low concentrations is changed to be vaso-contraction, and the changes in pulmonary arterial rings are most marked. DOPA of different concentrations all produce contraction effect on LPS-preincubated arterial rings.