ABSTRACT
Objective To observe the protective effect of the traditional Chinese medicine prescription, Jiu Nao Yi Zhi water extract, on human neuroblastoma SH-SY5Y cell line, its effect on expression of insulin signal transduction pathway, and to explore the related mechanisms.Methods SH-SY5Y cells cultured in vitro, were divided into control group, Jiu Nao Yi Zhi No.1 prescription group and No.3 prescription group.The doses were 0.0625 mg/mL, 0.125 mg/mL, 0.25 mg/mL, 0.5 mg/mL and 1 mg/mL.The thiazolyl blue ( MTT) metabolic rate of each group was determined.The dose of 0.125 mg/mL was chosen for cell immunofluorescence analysis, and to observe the expression of insulin receptor substrates-1 ( IRS-1 ) , cAMP response element binding protein ( CREB ) , and the factors of insulin signal transduction pathway.Results Compared with the control group, MTT metabolic rates of the Jiu Nao Yi Zhi groups were significantly increased (P<0.05), and the cell morphology was much better in those groups, cell body more plump, well-adherent and neurite extensions were observed.The expressions of IRS-1 and CREB were higher than that in the control group.Conclusions The traditional Chinese medicine prescription Jiu Nao Yi Zhi water extract can protect neurons by promoting nerve cell growth, and improving the expression of IRS-1 and CREB, the factors of insulin signal transduction pathway.
ABSTRACT
Objective To observe the expression of neural nicotinic acetylcholine receptor subunit α3 (α3nAChR) and extracellular regulated protein kinases (ERK1/2),c-Jun N-terminal kinase (JNK),p38 kinases of mitogen-activated protein kinase (MAPK) pathway in human neuroblastoma cell line SH-SY5Y overexposed to fluoride,and try to investigate the molecular mechanism of cell damage caused by overexposure of fluoride.Methods The SH-SY5Y cell with low expression of α3nAChR suppressed by silence interference RNA served as α3nAChR silence group;the normal SH-SY5Y cell served as control group,and the effect of silencing of αt3nAChR gene in SHSY5Y was detected by Western blotting and real-time PCR;SH-SY5Y cell was treated with different concentrations of fluoride (0.000,0.005,0.050,0.500,1.000,2.500,5.000 mmol/L),the safe concentration of fluoride in SHSY5Y cell was detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay;the SH-SY5Y cell of control group and α3nAChR silence group were treated with 4.000 mmol/L fluoride for 0,4,8,12,24,36,48 h according to the results of MTT assay;the expression of ERK1/2,JNK,p38 kinases of MAPK pathway in SH-SY5Y at protein levels was measured by Western blotting.Results The expression of α3nAChR mRNA (0.04 ± 0.03) and protein (12.0 ± 2.5) in α3nAChR silence group was decreased significantly compared with those of control group (1.00 ± 0.11,100.0 ± 11.3,t =24.58,28.80,all P ＜ 0.05).The viability of SH-SY5Y cell treated with 5.000 mmol/L fluoride (0.53 ± 0.15) was decreased significantly compared with that of SH-SY5Y cell treated with 0.000 mmol/L fluoride (1.05 ± 0.05,P ＜ 0.05).The increased expression of phospho-ERK1/2 was found in α3nAChR silence group and control group incubated with fluoride with time prolonged,and the expression of phospho-ERK1/2 increased significantly at time points 24,36 and 48 h (188.33 ± 7.33,200.00 ± 10.01,213.33 ± 11.55;125.33 ± 5.69,136.00 ± 4.52,155.33 ± 6.51) compared to 0 h in the same groups (100.00 ± 0.00,100.00 ± 0.00,all P ＜ 0.05),and the expression of phospho-ERK1/2 was higher significantly in α3nAChR silence group than those of control group (t =9.26,7.63,5.72,all P ＜ 0.05);no change of expression of total-ERK1/2 in the two groups was found with the passage of time.The gradually increased expression of phospho-JNK was found in α3nAChR silence group and control group,among which,the expression of phospho-JNK in o3nAChR silence group at time points 12,24,36 and 48 h (154.00 ± 6.25,149.00 ± 5.57,156.00 ± 6.08,141.67 ± 2.52) and in control group at 8,12,24,36,48 h (133.33 ± 10.69,173.00 ± 4.00,175.00 ± 11.79,200.67 ± 11.93,200.33 ± 18.58) was compared to those at 0 h in the same groups (100.00 ± 0.00,100.00 ± 0.00),and the difference was significant (all P ＜ 0.05);the higher expression of phospho-JNK was found in α3nAChR silence group other than control group at 8,12,24,36,48 h (t =-4.28,-5.02,-2.89,-8.33,-6.18,all P ＜ 0.05);no change of expression of total-JNK was found in the two groups (P ＞ 0.05).The increased expression of phospho-p38 was detected in control group at time points 24,36 and 48 h (120.33 ± 4.51,122.00 ± 7.55,119.67 ± 7.57) compared to 0 h in the same groups (100.00 ± 0.00,all P ＜ 0.05),and the expression of phospho-p38 was significantly higher than that in α3nAChR silence group at the same time points (93.33 ± 9.61,94.00 ± 5.01,98.33 ± 5.69,t =-4.01,-6.73,-5.59,all P ＜ 0.05);no change of expression of total-p38 was found in the two types of SH-SY5Y cells treated with fluoride (P ＞ 0.05).Conclusion When SH-SY5Y cells are exposed to fluoride;activation of ERK1/2 may be not depend on α3nAChR;α3nAChR may have protected the cell from apoptotic injury caused by activation of JNK pathway,and the activation of p38 may be depend on nAChRα3.
ABSTRACT
Retinoids play an important role in growth, reproduction and differentiation. Recently, retinoids have been used to both protect and treat from various animal models of carcinogenesis. In this study the effect of N-(4-hydroxyphenyl) retinamide (fenretinide) on viability of human neuroblastoma cell lines were evaluated. For the evaluation of apoptosis of human neuroblastoma cell lines by fenretinide. MTT assay, cytoplasmic DNA fragmentation, TUNEL stain, and Western blot analysis were performed. In MTT assay, fenretinide inhibited the proliferation of CHP134, IMR32 and SH-SY5Y but not in PC12 cells. Cytoplasmic DNA fragmentation was induced by treament of fenretinide (10 micrometer) for 48 h in IMR32 cells. PARP cleavage was detected by Western blot analysis after 16 h of treatment of fenretinide in CHP134, IMR32 and SH-SY5Y. These fenretinide effects on growth inhibition and increased apoptosis followed to the time dependent manner. The fenretinide treatment did not affect the phosphorylation of MAP kinases (ERK, JNK, p38). There was no change of Bcl-x and Bad expression after treatment of fenretinide (1 micrometer) in neroblastoma cell lines. Pretreatement of PD98059, SB203580, LY294002, or genistein also did not affect fenretinide-induced PARP cleavage in neuroblastoma cell lines. From these results, the fenretinide-induced apoptosis is due to the PARP cleavage which occured MAP kinase signal cascades independently.