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As one of the most lethal diseases, pancreatic cancer shows a dismal overall prognosis and high resistance to most treatment modalities. Furthermore, pancreatic cancer escapes early detection during the curable period because early symptoms rarely emerge and specific markers for this disease have not been found. Although combinations of new drugs, multimodal therapies, and adjuvants prolong survival, most patients still relapse after surgery and eventually die. Consequently, the search for more effective treatments for pancreatic cancer is highly relevant and justified. As a newly re-discovered mediator of gasotransmission, hydrogen sulfide (H
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Aim To investigate whether endoplasmic reticulum stress is involved in the neurotoxicity of sodi¬um arsenite and clarify whether over-expression of 3-mercaptopyruvate sulfurtransferase (MPST) regulates endoplasmic reticulum stress induced by arsenic. Methods The SH-SY5Y cell line stably expressing the exogenous MPST gene was obtained by constructing the lentiviral vector of MPST gene. The SH-SY5Y cells were randomly divided into six groups, the SR-MPST over-expression group stably expressing the exogenous MPST gene, SH-PEB control group transfected with empty vector, the arsenite treatment group ( NaAs02 group ), TUDC A treatment group ( blocker of endoplasmic reticulum stress ) and TUDC A + NaAs02 group. Western blot was used to examine the protein expression of GRP78 and CHOP after different treatment. Results Although MPST overexpression had no significant effects on the expression of GRP78 and CHOP proteins, NaAs02 could significantly increased the protein levels of GRP78 and CHOP ( P < 0. 01 ) and the up-regulation of GRP78 and CHOP proteins caused by NaAs02 could be blocked by the treatment of TUDC A. In addition, the inhibition by MPST overexpression on the arsenic-induced increase of GRP78 and CHOP proteins (P <0. 01 ) could also be reversed by the TUDC A treatment significantly. Conclusions The GRP78/ CHOP endoplasmic reticulum stress pathway is involved in the neurotoxic damage induced by arsenic; MPST overexpression may decrease arsenic-induced endoplasmic reticulum stress.
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Aim To investigate the effects of sodium arsenite (NaAsO2) on the cell cycle and growth, and the intervention of MPST over-expression in the neural cells. Methods NaAsO2 was used to treat SH-SY5Y neuroblastoma cells for 48 h from the blank control (BC), empty vector control ( transfected with empty vector, NC ) and over-expression group ( lentiviral transfection with MPST,OP). The methods of CCK-8, crystal violet staining,flow cytometry and Western blot were used to examine cell viability,adherent rate,cell cycle and protein expression of p53,CDC25A,CyclinA and CDK2. Results The cell viability and adherent rate significantly decreased after treatment with NaAsO2 for 48 h,which was reversed in OP group (P <0. 01). Meanwhile, NaAsO2 also significantly increased the proportion of S phase cells and p53 protein expression, and down-regulated the protein levels of CDC25A,Cyc-lin A and CDK2 in BC and NC groups ( P < 0. 01), whereas the above changes of protein levels were significantly antagonized in OP group compared with NC group (P < 0. 05, P < 0. 01). Conclusions NaAsO2 inhibits the cell growth by inducing S-phase arrest and over-expression of MPST could reverse the noxious effects caused by NaAsO2 in SH-SY5Y cells.
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Objective To investigate the expression changes of the hydrogen sulfide synthases cystathionineγ-lyase (CSE), cystathionineβ-synthase (CBS), and 3-mercaptopyruvate sulfurtransferase (3-MST), after optic nerve crush (ONC) in rat the retina.Methods The rat model of ONC was established.Rats were divided into normal control, ONC, and sham control groups.Histopathologic changes in retina, the number of retinal ganglion cells (RGC) and retinal thickness of inner part (RTIP) were measured.The changes of CSE, CBS and 3-MST mRNA expression were detected with quantitative real-time PCR.Results The retinal histostructure was normal in normal controls and with minor changes in sham controls, respectively.Compared with sham group, significant retina damages were found in the ONC group:a time-dependent reduction of RGC number and RTIP.Expressions of CSE, CBS and 3-MST mRNA in rat retina were detected in normal control.Compared with normal controls, the expressions of CSE, CBS and 3-MST mRNA did not show any significant changes in the sham controls.Compared with sham controls, CBS mRNA expressions showed a time-dependent increase at 3 d, 7 d and 14 d after crush in the ONC group;CSE mRNA expressions increased to the peak at 3 d and then slightly reduced at 14 d after crush;3-MST mRNA expressions showed the trend of increase at 3 d and 7 d and then enhanced remarkably at 14 d after crush.Conclusion Hydrogen sulfide synthases CSE, CBS and3-MST expressions were up-regulated in rat retina following ONC, which may cause an increase in local endogenous hydrogen sulfide production in the retina and a compensatory protective effect.