Effect of Notch1 on extracellular matrix deposition in the renal tubulointerstitium of diabetes / 生理学报

The aim of the present study was to observe the effects of Notch1 and autophagy on extracellular matrix deposition in renal tubulointerstitium of diabetes and to explore the mechanism. The mice were randomly divided into normal control group (db/m mice) and diabetes group (db/db mice). After 12 weeks of feeding, the mice were sacrificed and the corresponding biochemical indexes were measured. Rat renal tubular epithelial cells NRK52E were cultured under normal glucose (NG) and high glucose (HG) respectively, and the expression of Notch1 and LC3 proteins were detected by Western blotting. Autophagosomes in NRK52E cells with overexpressed and knockdown Notch1 under NG and HG conditions were observed by confocal microscope, and the expression changes of Notch1, Collagen-I and III protein were detected by immunofluorescence. The results showed that the Notch1 and Collagen-III expressions were increased (P < 0.01) and the LC3 expression was decreased (P < 0.05) in db/db mice compared with db/m mice. In vitro, the Notch1 was increased (P < 0.01) and the LC3 expression was decreased significantly (P < 0.01) in NRK52E cells of HG group compared with NG group. There was no significant change of Notch1 and LC3 expression between the mannitol (MA) group and the NG group. Autophagy was decreased and extracellular matrix deposition was aggravated when Notch1 was overexpressed. In contrast, autophagy was increased and extracellular matrix deposition was relieved by knockdown of Notch1 under HG conditions. In conclusion, Notch1 protein expression was increased and autophagy was reduced in renal tissue of diabetes and renal tubular epithelial cells under HG. The extracellular matrix deposition in the renal tubulointerstitium was relieved by regulating autophagy after the knockdown of Notch1.

Inhibitory effects of small interfering RNA targeting c-myc in combination with 5-fluorouracil on the growth in vitro and in vivo / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To observe the effects of small interfere RNA (siRNA) targeting the c-myc in combination with 5-fluorouracil (5-Fu) on the growth of Hep-2 cells in vitro and in vivo.</p><p><b>METHODS</b>Hep-2 cells transfected with or without c-myc siRNA were treated with 5-Fu for 48 h. C-myc protein levels in Hep-2 cells were detected using the Western blot. The cell cycle was analyzed by flow cytometry. Hep-2 cells were subcutaneously inoculated into the back of BALB/c nude mice to establish the implanted laryngeal squamous carcinoma model. PBS, c-myc siRNA, and 5-Fu, alone or in combinations were administered i.p. The mice were sacrificed after the treatments and the tumor masses were removed to determine the tumor volume and weight. The inhibitory rate was calculated. Expression of c-myc in tumor tissue was detected by immunocytochemistry and cell apoptosis was analyzed by terminal transferase dUTP nick end labeling (TUNEL).</p><p><b>RESULTS</b>The protein levels of c-myc decreased after transfected with c-myc siRNA. C-myc siRNA-transfected cells showed an increase in the percentage of cells in the GO-G1 phase and a decrease in the percentage of cells in the S phase. When combined with 5-Fu, the results were improved. The tumor growth was faster in the control group and was significantly slower in the c-myc siRNA plus 5-Fu group than that in the c-myc siRNA group or 5-Fu group (P < 0.05). The tumor weight in the c-myc siRNA plus 5-Fu group was significantly smaller than that in the c-myc siRNA or 5-Fu group (P < 0.05). Immunohistochemistry showed that c-myc siRNA inhibited the expression of c-myc in tumor tissues in the c-myc siRNA group and c-myc siRNA plus 5-Fu group (P < 0.05). The number of apoptotic cells in the c-myc siRNA plus 5-Fu group was higher than those in the c-myc siRNA groups (P < 0.05).</p><p><b>CONCLUSIONS</b>C-myc siRNA inhibits the expression of c-myc in Hep-2 cells and in the tumor tissues of nude mice. C-myc siRNA combined with 5-Fu inhibits the growth of implanted laryngeal squamous carcinoma and promotes cell apoptosis. C-myc could become a novel target for the treatment of laryngeal squamous carcinoma.</p>