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Objective To investigate the regulatory effect of nobiletin (NOB) at typical effective doses on intestinal stem cells in vivo and in vitro. Methods After a 3D culture model of mouse colorectal tumor cell line MC38 was constructed, the death and survival of the obtained colonies were observed after treatment of different concentrations of NOB. Mouse small intestinal crypts were cultured in the Matrigel to generate organoids. Different concentrations of NOB were added to the culture system, and the sprouting and growth of the organoids were observed. MTT assay was used to calculate the area and absorbance values of the organoids after staining. The organoid growth was observed by removing 50 and 100 μmol/L NOB for different periods. The effects of exogenous R-spondin1 and CHIR99021 (activators of Wnt pathway) on the growth of organoids were observed in the culture system with 50 and 100 μmol/L NOB treatment. C57/B6J mice were infused with different concentrations of NOB by gavage for 4 consecutive days. The ratio of intestinal crypt to villus length, cell apoptosis, and number of OLfm4 and BrdU double positive cells were calculated and observed. Results Compared with the control group, 50 μmol/L NOB significantly promoted the death of MC38 cells after sphere formation and significantly reduced the colony formation rate (P < 0.001). The dose also significantly inhibited the budding of intestinal organoids, and 50~200 μmol/L NOB significantly inhibited the growth of intestinal organoids in a dose-dependent manner when compared with the control group (P < 0.001). After NOB withdrawal, the growth of intestinal organoids in the 50 μmol/L group was partially recovered, but it was difficult to recover to normal level in the 100 μmol/L NOB group. Enhanced Wnt pathway activation could partially rescue the inhibitory effect of NOB on intestinal organoids. In vivo administration of higher concentrations of NOB did not induce apoptosis of intestinal crypt cells, did not affect the crypt to villus ratio, and had no effects on the number and proliferation status of intestinal stem cells. Conclusion NOB possesses the ability to inhibit normal intestinal stem cells by regulating stem cell-related pathways such as Wnt, but this cellular inhibition cannot be phenocopied in vivo. Our study suggests the safety of NOB at regular concentration and also raises a caution to explain the inhibitory role of NOB in cancer models.

Objective To investigate the effects of interleukin22 (IL22) in acute colitis induced by dextran sulfate sodium salt (DSS) in mice and its underlying mechanism. Methods Three IL22 knockout mice (IL22-/-) and 3 control mice (IL22+/+) of 8-week-old males were subjected from the same litter, and then had free-choice drinking of 2.5% DSS water for 6 d followed by normal water for 2 d to construct a mouse model of acute colitis. The changes in body mass weight and disease activity index (DAI) were measured and calculated. After the intervention of 8 d, mouse enteroscopy was performed, and the length of colon and the organ index of major immune organs were measured in both groups. Protein levels of pro-inflammatory cytokines, such as IL1α, IL1β, IL6 and TNFα were detected by Western blotting. Adeno-associated virus (AAV) transfection model was established in 8-week-old male C57BL/6 mice, which were then treated by 2.5%DSS drinking. The mice were randomly divided into PBS group (n=5), AAV-mock+DSS group (n=5) and AAV-IL22+DSS group (n=5). The expression levels of colonic closed small loop protein 1 (ZO-1) and calcium adhesion protein (E-claudin) in different groups were detected by immunofluorescence assay. The protein levels of IL22, Occludin, Stat3 and p-Stat3 were detected by Western blotting. Results Compared with the IL22+/+ group, the mice in the IL22-/- group had significantly decreased body weight on day 8 (P

Crushing seed melon machine is the key equipment in making full use of the production line, in which skin flesh separating device has a direct impact on the injury rates and the net rate. Subsequently it affects skin flesh beating separation process, as well as the utilization of watermelon flesh and seeds skin merchantability. To solve this problem, this paper intends to deal with a single factor research on the performance of separating skin from flesh device and then an orthogonal experiment on its performance by means of the full appliance of the high productive self-developed seed melon crushing machine. It is also based on the characteristic of the separating roller cone of the skin flesh separating device, through changing the main performance parameters of the conical separation roller. The results of the experiment show that the main factors affecting the damaging seed rate include:separation roller speed, the minimum distance between screen and roller blade, and separation roller taper, which is also the case of the taking off seeds net rate. Considering the extent to which the experimental factors affect damaging seed rates and taking off the seeds net rate and the practical processing requirements of seed melon, the operating parameters of separating skin from flesh device are optimized as:separating skin from flesh roller works at the speed of 98.5 r.min-1; the minimum distance between screen and roller scraper is 20 mm;skin flesh separating roller taper is 4°. The result of the optimized experiment indicates the damaging seed rate<2% and the taking off seeds off net rate of >98%. This research can provide a reference for designing and researching relevant crushing seed melon machine. [ABSTRACT FROM AUTHOR]