ABSTRACT
This study examined the expression pattern of programmed cell death 5 (PDCD5) in cochlear hair cells and spiral ganglion neurons (SGNs) and its association with age-related hearing loss in mice.Sixty C57BL/6J (C57) mice at different ages were divided into four groups (3,6,9 or 12 months).PDCD5 expression was detected by using immunohistochemistry,real-time PCR and Western blot.Morphological change of the cochleae was also evaluated by using immunoassay.The results showed that the expression of PDCD5 had a gradual increase with ageing in both protein and RNA levels in C57 mice,as well as gradually increased apoptosis of cochlear hair cells and SGNs.In addition,we also found that caspase-3 activity was enhanced and its expression was enhanced with ageing.It is implied that overexpression of PDCD5 causes the increase in caspase-3 activity and the subsequent increase of apoptosis in cochlear hair cells and SGNs,and thereby plays a role in the pathogenesis of presbycusis.Thus,PDCD5 may be a new target site for the treatment and prevention of age-related hearing loss.
ABSTRACT
Th2 cytokines play a pivotal role in the pathogenesis of allergic rhinitis.To investigate the effect of p38 mitogen-activated protein kinase(MAPK)on the production of Th2 cytokines such as IL-4 and IL-5 in allergic rhinitis,a model of allergic rhinitis was established in SD rats.The expression level of p38 MAPK mRNA in PBMCs was detected by means of real time quantitative RT-PCR.The p38 MAPK activity in PBMCs was detected by Western blotting.PBMCs were cultured with various concentrations of p38 MAPK inhibitor SB 239063 or without the treatment,and then IL-4,IL-5 levels of the supernatant were determined by using sandwich ELISA.The results showed that mRNA expression and activity of p38 MAPK in PBMCs were significantly higher in allergic rhinitis rats than in control rats(P<0.05).The p38 MAPK inhibitor SB 239063 decreased the production of IL-4 and IL-5 in a dose-dependent manner.It is concluded that p38 MAPK plays an important role in the pathogenesis of allergic rhinitis which is associated with Th2 cytokines release.
ABSTRACT
The effect of quercetin (Que) on proliferation and apoptosis of human nasopharyngeal carcinoma HEN1 cells was investigated. Inhibition rate of quercetin on HEN1 was assayed by MTT method, apoptosis by flow cytometry (FCM), and the caspase-3 expression of each group by colorimetry set respectively. Quercetin inhibited HEN1 cells in in a dose-(r=0.709,P<0.01) and time-dependent manner (r=0.703,P<0.01). The ratio of apoptotic and necrosis cells was increased in the cells treated with quercetin. Cell cycle was specificly arrested in G2/M phase. Apoptosis cusp was revealed by FCM. The activity of caspase-3 was significantly up-regulated in 5 groups treated with quecetin as compared with control group (P<0.05). It was concluded that the growth inhibition of quercetin was highly related to cell cycle arrest at the G2/M phase and induction of caspase-dependent apoptosis in human nasopharyngeal carcinoma HEN1 cells.