ABSTRACT
Objective To investigate the effect of phosphatidylinesitol-3 kinase/serine threonine kinase (PI3K/Akt) signaling pathway on expression of beta-site amyloid precursor protein cleaving enzyme-1 (BACE1) in the hippocampus neurons of rat brain. Methods Forty SD rats were randomly divided into 4 groups: blank control group, sham-operated group, insulin group and wortmannin group. Insulin or the specific inhibitor of PI3K, wortmannin was injected into hippocampus neurons to activate or inhibit the signaling pathway in insulin group or wortmannin group, respectively. Immunoprecipitation and Western blot were used to analyze the proteins levels of PI3K/Akt and BACE1. Results In insulin treatment group,among the proteins downstream of signaling pathway, expression of Akt increased (0. 952±0.060 vs 0.835±0.029,t=4.9150, P=0.0001), phospho-Akt set473 increased (0.800±0.075 vs 0.657± 0.025,t=4.5598, P=0.0002), phospho-GSK-3α decreased (0.604±0.062 vs 0.726±0.041, t= 3.5871, P=0.0018 ), and the expression of mature BACE1 and β-CTF significantly decreased. In wortmannin group, the expression of Akt and phospho-Akt ser473 were inhibited; phospho-GSK-3α increased ; mature BACEI (1.004±0.096) and β-CTF (1.031±0.048) increased (t=11.5980, P= 0.0000 and t =4.2194, P =0.0004, respectively). Conclusions PI3K/Akt signaling pathway might effect the expression of BACE1, in which impaired signaling pathway may cause the amyloid precursor protein to be easily processed by BACE1, and thus involves the pathology of Alzheimer' s disease.
ABSTRACT
Objective To investigate the differential expression of secretory aspartyl proteinase in patients with vaginal C.albicans infection and in asymptomatic candidal carriers.Methods Secretory aspartyl proteinase expression was determined with reverse transcription-PCR in vaginal specimens taken from 10 asymptomatic candidal carriers,14 patients with vulvovaginal candidiasis (VVC) and 10 patients with recurrent VVC (RVVC).Results SAP2 and SAP4 to SAP6 subfamily were detected in both candidal carriers and patients with vaginal candidiasis.SAP1 and SAP3 transcripts were not observed in 10 asymptomatic candidal carriers.All 9 SAP genes were differently expressed in VVC and RVVC patients.SAP1 and SAP3 transcripts were frequently amplified in some patients.Conclusion It is shown that C.albicans infection is associated with differential expression of individual SAP genes,which may be involved in the pathogenesis of vaginal candidiasis.
ABSTRACT
Objective To study the effects of hypoxia and reoxygenation on expression of a disintegrin and metalloprotease10(ADAM10),?-amyloid precursor protein cleaving enzyme(BACE1) mRNA in SH-SY5Y cells.Methods SH-SY5Y cells were grouped into hypoxic and control groups.The hypoxic cells were incubated in hypoxic condition(95%N_2,5%CO_2) for 12 hours and 24 hours,and then cells were reoxygenated for 0 hours,12 hours and 24 hours.The expression of ADAM10,BACE1 mRNA were tested respectively at different time points after reoxygenation by RT-PCR.Control groups were incubated in normal conditions,seeded and treated at the same time with the hypoxic cells.Results The expression of ADAM10 mRNA was down-regulated by 19.8%,41.4% and 64.6%(P=0.005,0.038,0.001) at different time after reoxygenation with 12 hours hypoxia and down-regulated by 30.1%,75.9% and 86.5%(P=0.009,0.005,0.043)after reoxygenation with 24 hours hypoxia.The expression of BACE1 mRNA was up-regulated by 31.5% and 35.1%(P=0.028,0.005)only at 12 hours and 24 hours points after reoxygenation with 24 hours hypoxia.Conclusion Hypoxia and reoxygenation might alter the expression of ADAM10 and BACE1,which demonstrates that the vascular factors should make the amyloid precursor protein easy to be processed by ?-secrease pathway,thus to involve the pathology of Alzheimer's disease.
ABSTRACT
Objective To analyze the expression of secreted aspartyl proteinases (Sap) in human vaginal infection in vivo. Methods Vaginal swabs were collected from 9 healthy volunteers and 20 patients with vaginal candidiasis, and the expression of Sap1-6 was evaluated by reverse-transcriptase polymerase chain reaction using specific primer sets. Results The Sap2 and Sap5 were the most common genes expressed in the patients with vaginal candidiasis. The expression Sap3 and Sap4 was detected in all subjects. All six Sap genes were simultaneously expressed in some patients with vaginal candidiasis. Conclusion The data shows that the Sap genes may be involved in the pathogenesis of vaginal candidiasis.