In vitro study on role of Hsp70 expression in DNA damage of human embryonic lung cells exposed to Benzo[a]pyrene

Objective Benzo[a]pyrene (B[a]P), a ubiquitous environmental pollutant, is a potent procarcinogen and mutagen that can elicit tumors, leading to malignancy. Heat shock proteins (Hsp) have been shown to protect cells against damages caused by various stresses including exposure to numerous chemicals. Whether Hsps, or more specifically Hsp70, are involved in repair of B[a]P-induced DNA damage is currently unknown. Methods We assessed the potential role of the inducible form of Hsp70 in B[a]P-induced DNA damage of human embryonic lung (HEL) cells using immunoblot and the comet assay (i.e., the single cell gel electrophoresis assay). Results Exposure to B[a]P induced a dose-dependent decrease in the level of Hsp70, but a dose-dependent -increase in DNA damage both in untreated (control) HEL cells and in cells preconditioned by a heat treatment. Heat preconditioning prior to B[a]P exposure potentiated the effect of B[a]P at a low dose (10μmol/L), but appeared to be protective at higher doses. There was a negative correlation between Hsp70 level and DNA damage in the non-preheated as well as in the preconditioned cells.Conclusion These data suggest that exposure of HEL cells to B[a]P may induce a dose-dependent reduction in the levels of the inducible Hsp70. The detailed mechanisms for the reduction of Hsp70 levels by B[a]P and the role of Hsp70 in DNA damage under different concentrations of B[a]P remains to be determined.     

The expression of the products of IGF-Ⅱ,IGF-Ⅱ receptors and CSF-Ⅰ receptors in human primary hepatocellular carcinoma and juxtacancerous liver tissue

The expression of the products of IGF-Ⅱ,IGF-Ⅱ receptors(IGF-Ⅱ-R)and CSF-Ⅰ re-ceptors(CSF-Ⅰ-R)was observed in 17 cases of human primary hepatocellular carcinoma(PHC)and the juxtacancerous liver tissue with immunohistochemistry(ABC),Western blot and North-ern blot technique,It was found that the expression of IGF-Ⅱ,IGF-Ⅱ-R and CSF-Ⅰ-R was signif-icantly higher in PHC than in normal liver tissue and the expression of IGF-Ⅱ and IGF-Ⅱ-R wasremarkably higher in the juxtacancerous liver tissue from PHC patients than in PHC proper.Itwas noteworthy that the expression of IGF-Ⅱ in both the cancer proper and the juxtacancerousliver tissue was characterized by its fetal type.Besides,the expression of CSF-Ⅰ-R was signifi-cantly higher in PHC than in the juxtacancerous liver tissue.It is believed that the abnormal ex-pression of IGF-Ⅱ,IGF-Ⅱ-R and CSF-I-R in PHC and the juxtacaneerous liver tissue might berelated to the autocrine mechanism of human PHC.     

Effect of Acetaldehyde on Oxidoreductases in Tissues of Rats at Different Ages

The toxicity of acetaldehyde and age related changes on oxidoreductases in the liver,brain,kindney,and muscle offemale albino rats(Wistar strain)were studied.The specific activities of lactate[LDH],isocitrate[ICDH(NAD/NADP)],succinate[SDH],malate[MDH],glutamate[GDH]and glucose-6-Phosphate[G-6-PDH]dehydrogenases were significantly increased as a function of age.However,acetaldehyde treatment significantly inhibited oxidoreductases in the tissues of 21,90 and 180day old rats.Liver enzymes of young(21 days)rats exhibited greater sensitivity to acetaldehyde toxicity.Similar innhibition of oxidoreductases in brain and kidney of adult(180days)rats treated with acetaldehyde was observed.LDH and GDH as compared to other enzymes studied showed higher susceptibility to acetaldehyde toxicity.The differential sensitivity of tissues and inhibition of oxidoreductases by acetaldehyde as a function of age could be attributed to hypoxic conditions,energy crisis,and mitochondrial structural changes.The results suggest that acetaldehyde affects oxidation of glucose via HMP shunt pathway,glycolytic pathway and Krebs cycle resulting in the impairment of carbohydrate metabolism.     

Effect of glucocorticoid treatment on insulin like growth factor-Ⅰ and its binding proteins in children with nephrotic syndrome

Objective To identify the changes in serum insulin like growth factor-Ⅰ (IGF-Ⅰ) and IGF binding proteins (IGFBPs) in children with nephrotic syndrome (NS) and the effect of glucocorticoid on serum IGF-Ⅰ and IGFBPs. Methods We measured serum IGF-Ⅰ and IGFBPs levels by radioimmune assay and immune radiomagnetic assay in 36 children with NS, consisting of an active stage group (ANS, n=12), a remission stage group (RE, n=12), an active stage group with glucocorticoid treatment (GNS, n=12), and a normal control group (NC, n=10). Results 1) Compared to NC, serum levels of IGF-Ⅰ and IGFBP-3 were decreased (P<0.01); serum levels of IGFBP-1 and IGFBP-2 were increased (P<0.01) in the ANS group. 2) Serum levels of IGF-Ⅰ and IGFBP-3 were higher and IGFBP-1 and IGFBP-2 were lower in the RE Group than in theANS Group (P<0.01). 3) Compared to the ANS group, serum levels of IGF-Ⅰ and IGFBP-3 were increased (P<0.01) and serum levels of IGFBP-1 and IGFBP-2 were decreased (P<0.01) in the GNS group. 4) A correlation was found between serum levels of IGFBP-3 and albumin in the active stage group (r=0.76 P<0.01). There was also a correlation between serum levels of IGF-Ⅰ and IGFBP-3 and an inverse correlation between the serum level of IGF-Ⅰ and serum levels of IGFBP-1 and IGFBP-2 in the ANS group. No other correlations were observed.Conclusions The serum levels of IGF-Ⅰ and IGFBPs are altered in children in the active stage of NS, but return to normal in the remission stage. GC treatment may influence serum IGF-Ⅰ and IGFBPs in children with NS. Changes in IGF-Ⅰ and IGFBPs levels may play a role in the growth retardation of NS children.     

Prevention of beta cell dysfunction and apoptosis by adenoviral gene transfer of rat insulin-like growth factor 1

Background Islet β-cells are almost completely destroyed when patients with type 1 diabete are diagnosed. To date, insulin substitute therapy is still one of the main treatments. The cure of type 1 diabetes requires β-cell regeneration from islet cell precursors and prevention of recurring autoimmunity. Therefore, β-cell regeneration and proliferation emerge as a new research focus on therapy for type 1 diabetes. Islet β-cell regeneration and development are controlled by many growth factors, especially insulin-like growth factor-1 （IGF-1）. Methods Recombinant adenovirus encoding rat IGF-1 （rlGF-1） was constructed and transduced into rat β-cells, RINm5F cells. Western blotting analysis and ELISA were used to detect rlGF-1 protein. Streptozotocin （STZ） was used to induce RINm5F cell destruction. The level of nitric oxide （NO） was detected in cell culture supernatants by the Griess reaction. Islet cell function was evaluated by glucose-stimulated insulin production. Flow cytometry analysis was further used to investigate the apoptosis of RINm5F cells. Thiaoollyl blue viability assay was applied to determine cell viability. Results The recombined adenovirus-rlGF-1 was successfully constructed and the titer was 4.0×10^8 pfu/ml. The rlGF-1 protein was effectively expressed in the RINm5F cells and cell culture supernatants, rlGF-1 expression remarkably inhibited STZ-induced islet cell apoptosis and significantly decreased the level of NO. Furthermore, IGF-1 expression also significantly protected insulin secretion and cell proliferation in a time-dependent manner. Conclusions Our study suggests that locally produced rlGF-I from RINm5F cells may be beneficial in maintaining β-cell function, protecting β-cells from the destruction of apoptosis factors and promoting β-cell survival and proliferation. IGF-1 might be considered as a candidate gene in gene therapy for type 1 diabetes. In addition, it appears that the apoptosis induced by STZ may be NO-dependent.     

Effect of Kaiyu Qingwei Granule (开郁清胃颗粒) on Insulin Receptor in Liver and Skeletal Muscular Cell Membrane in Diabetes Mellitus Rats

Objective: To investigate the effect of Kaiyu Qingwei granule (KYQWG, on the insulin binding capacity of liver and skeletal muscular cell membrane and serum insulin-like growth factor-1 (IGF-1) in streptozotocin-induced diabetic rats. Methods: Rats in four experimental groups were investigated: the control group, the model group, the KYQWG group and the Metformin group. The insulin binding rate (IBR) of liver and skeletal muscular cell membrane was detected by receptor-ligand ra-diometric method and changes of serum levels of glucose, insulin and IGF-1 were observed before and after 4 weeks of medication. Results: The KYQWG group had a lower blood glucose level and ffiR of liver and muscular cell membrane, as compared with those in the model group (P<0. 01 or P<0.05), and a higher level of IGF-1 than that in the model group(P<0.01), but had no obvious changes in the serum level of insulin. Conclusion: KYQWG may increase the serum level of IGF-1 in diabetic rats, thus to decrease the insulin resistance a     

Analysis of 287 patients with aortic dissection: General characteristics,outcomes and risk factors in a single center

The general characteristics,outcomes and risk factors of the patients with aortic dissection(AD) were evaluated in a single medical center.From January 2002 to December 2008,284 patients with AD were treated and followed-up at our institution,including 105 cases of type A AD and 179 cases of type B AD.The patients in each type were divided into three groups according to management:medical treatment group(A or B),open surgery group(A or B),and stent-graft group(A or B).The characteristics and follow-up outcomes were compared between the groups or subgroups.The results showed that there was significant difference in the prognosis for type A AD between medical treatment group and open surgery group,but there was no significant difference in the prognosis for type B AD between medical treatment group and stent-graft group.Independent risk factors of follow-up mortality for patients with type A AD included a history of atherosclerosis(HR,3.807;95% confidence interval [CI],1.489 to 7.611;P=0.003),in-hospital hypotension/shock(HR,4.687;95% CI,1.846 to 11.900;P=0.001),in-hospital myocardial ischemia or infarction(HR,3.734;95% CI,1.613 to 8.643;P=0.002),pleural effusion(HR,2.210;95% CI,1.080 to 4.521;P=0.030),branch vessel involvement(HR,2.747;95% CI,1.202 to 6.278;P=0.016) and surgical treatment(HR,0.177;95% CI,0.063 to 0.502;P=0.001).And there were insignificant independent predictors for mortality of the patients with type B AD.It was concluded that there were significant differences in characteristics and one year mortality between type A AD and type B AD,but after one year,there was no significant difference in the mortality and complications of them.There were several discordant risk factors of AD,such as female gender,age,thrombus,abrupt onset of pain that were considered as the risk factors in some papers.And there was no definite risk factor of mortality in this study in the patients with type B AD.     

Association of Insulin-like Growth Factors with Lung Development in Neonatal Rats

To explore the relationship between Insulin-like growth factor (IGF)-Ⅰ,-Ⅱ and lung development in neonatal rats. 80 timed pregnant Sprague-Dawley (SD) rats were randomly divided into 4 groups (n=20): group A (Control group), group B (Dexamethasone (DEX) 1 group),group C (DEX 2 group), group D (retinoic acid (RA) group). 20 pregnant rats in group A, B and D were injected subcutaneously or intraperitoneally with vehicle (NS), DEX, or RA respectively during gestational day 16 to 18. All newborn rats in group C were subcutaneously injected with DEX at day 1 to 3 after birth. The lung tissue was obtained at the following times: fetuses at gesta-tional ages of 18, 20 and 21 days, and 1, 3, 5, 7, 10, 14 and 21 days after birth. Lung tissues were used for histopathological study, the polypeptides analysis of IGF-Ⅰ, -Ⅱ(immunohistochem-istry and Western blot) and mRNA analysis ( RT- PCR). The results showed that the strongest expression of IGF-Ⅰ in group A and D occurred at ages of 5—7 days (alveolar stage). The stronger their expressions, the better the alveolar develop. The peak stage of expression in group B occurred earlier, on the day 3 after birth. Compared with group A, the expression of IGF-Ⅰ during gestation age of 18 days to age of 3 days in group B were significantly higher (P＜0.01), but significantly lower at other time points (P＜0.01). The expression of IGF-Ⅰ was lower in group C all the time and always higher in group D than those in group A (P＜0.01). The peak expression of IGF-Ⅱ took place at the gestation age of 18 days, then gradually dropped to trace. During 18 days of gestation to age of 3 days, the expression of IGF-Ⅱ in group B was significantly higher than that in group A (P＜0.01). No difference was found among all other groups. The change in the expression of IGF-Ⅰ, -Ⅱ mRNA in all 4 groups was similar to that of their polypeptides. The results suggested that there is a close linking between IGF- Ⅰ, -Ⅱ and lung development in newborns. The IGF-Ⅱ works at early stage and the that of IGF-Ⅰ works at the stage of new septa formation and alveoli maturation. The stronger their expressions, the more mature the lung development.