Glucagon-like peptide-1 protects INS-1 cells from interleukin-1β-induced damage by inhibiting the nuclear factor-κB pathway / 南方医科大学学报

<p><b>OBJECTIVE</b>To observe the effect of glucagon-like peptide-1 (GLP-1) on interleukin-1β (IL-1β)-induced damage in INS-1 cells and explore its possible mechanisms.</p><p><b>METHODS</b>INS-1 cells were divided into normal control group, IL-1β group, and GLP-1+IL-1β group with corresponding treatments. The cell viability was determined by MTT assay, the expression of IKKβ mRNA was detected by real-time PCR, and that of the protein p65 was detected by Western blotting.</p><p><b>RESULTS</b>In comparison with the normal control group, the cells in the IL-1β group showed a significantly decreased viability by 29% (P < 0.01); compared with those in IL-1β group, the cells in GLP-1+IL-1β group exhibited an significant increase in the cell viability by 30% (P < 0.01). In comparison with the normal control group, the cells in IL-1β group showed an significantly increased expression of IKKβ mRNA (1.967 ± 0.091 vs 1 ± 0, P < 0.05); GLP-1 significantly reduced IL-1β-induced increment of IKKβ mRNA expression to 1.287 ± 0.084 (P < 0.05). IL-1β treatment significantly increased NF-κB protein expression as compared to the control level (0.814 ± 0.111 vs 0.396 ± 0.026, P < 0.01), and GLP-1 significantly inhibited such effect (0.622 ± 0.059, P < 0.05).</p><p><b>CONCLUSIONS</b>GLP-1 inhibits IL-1β-induced β-cell damage probably by inhibiting the NF-κB pathway.</p>

Effects of heme oxygenase-1 on proteins related to apoptosis in INS-1 cells exposed to intermittent high glucose / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effect of heme oxygenase-1(HO-1) on proteins related to apoptosis in INS-1 cells with exposure to intermittent high glucose.</p><p><b>METHODS</b>INS-1 cells cultured in vitro were divided into control group, persistent high glucose group (PHG), intermittent high glucose group (IHG), CoPP + intermittent high glucose group (CoPP+IHG), and ZnPP+ intermittent high glucose group (ZnPP+IHG). After 72 h of treatment with the corresponding protocols, the cells were examined for expressions of HO-1 protein by Western blotting and for expressions of Bax and Bcl-2 by immunocytochemistry.</p><p><b>RESULTS</b>In comparison with the control group, the cells in both PHG group and IHG group showed significantly increased expressions of HO-1 (P<0.01) and decreased Bcl-2/Bax ratios (P<0.05). The cells in CoPP+ IHG group exhibited a greater HO-1 protein expression but a lower Bcl-2/Bax ratio than those in IHG group (P<0.05) The ZnPP+IHG group demonstrated opposite changes in terms of HO-1, Bax and Bcl-2 expressions compared with the CoPP+IHG group.</p><p><b>CONCLUSION</b>Intermittent high glucose can lower Bcl-2/Bax ratio in INS-1 cells, and HO-1 may protect INS-1 cells against apoptosis possibly by up-regulating the Bcl-2/Bax ratio.</p>

Characteristic Analysis of Cooperation Hydrogen Production Using Rhodopseudomonas sp. DT and Enterobacter Aerogenes / 微生物学通报

Cooperation hydrogen production was carried out using Rhodopseudomonas sp. DT and Enterobacter aerogenes. The effects of the initial ratio of Rhodopseudomonas sp. DT and E. aerogenes, culture temperature, and carbon source on the cooperation hydrogen production were investigated. The results suggested that cooperation hydrogen production rate was highly affected by the initial ratio of Rhodopseudomonas sp. DT and E. aerogenes. The mixed bacteria of Rhodopseudomonas sp. DT and E. aerogenes with 1:1 initial ratio benefited to the cooperation hydrogen production, which led the hydrogen production rate and duration of gas production to 3.1 mol H2/mol glucose and 81 h, respectively. The pH dynamics analysis of culture medium further discovered that the pH of the mixed bacteria with 1:1 initial ratio changed from 6 to 7 smaller than other conditions, which was probably fitted to produce hydrogen. Furthermore, the mixed bacteria with 1:1 initial ratio had the higher hydrogen production efficiency at temperatures of 28?C and 37?C than at 20?C, and without any hydrogen production at temperature of 50?C. The carbon sources of glucose, succinate acid, malic acid could be used to produce hydrogen by the mixed bacteria. Even the soluble starch, unused by Rhodopseudomonas sp. DT, was also decomposed by the mixed bacteria to produce hydrogen with the conversion efficiency of 8.22%. The glucose was the optimal carbon resource, and the conversion efficiency could reach to 36.11%. The results, further, implied that the cooperation hydrogen production could enlarge the use of the carbon sources.