NKD1 promotes glucose uptake in colon cancer cells by activating YWHAE transcription / 南方医科大学学报

OBJECTIVE@#Bo investigate the regulatory relationship between NKD1 and YWHAE and the mechanism of NKD1 for promoting tumor cell proliferation.@*METHODS@#HCT116 cells transfected with pcDNA3.0-NKD1 plasmid, SW620 cells transfected with NKD1 siRNA, HCT116 cells with stable NKD1 overexpression (HCT116-NKD1 cells), SW620 cells with nkd1knockout (SW620-nkd1-/- cells), and SW620-nkd1-/- cells transfected with pcDNA3.0-YWHAE plasmid were examined for changes in mRNA and protein expression levels of YWHAE using qRT-PCR and Western blotting. Chromatin immunoprecipitation (ChIP) assay was used to detect the binding of NKD1 to the promoter region of YWHAE gene. The regulatory effect of NKD1 on YWHAE gene promoter activity was analyzed by dual-luciferase reporter gene assay, and the interaction between NKD1 and YWHAE was analyzed with immunofluorescence assay. The regulatory effect of NKD1 on glucose uptake was examined in the tumor cells.@*RESULTS@#In HCT116 cells, overexpression of NKD1 significantly enhanced the expression of YWHAE at both the mRNA and protein levels, while NKD1 knockout decreased its expression in SW620 cells (P < 0.001). ChIP assay showed that NKD1 protein was capable of binding to the YWHAE promoter sequence; dual luciferase reporter gene assay showed that NKD1 overexpression (or knockdown) in the colon cancer cells significantly enhanced (or reduced) the transcriptional activity of YWHAE promoter (P < 0.05). Immunofluorescence assay demonstrated the binding of NKD1 and YWHAE proteins in colon cancer cells. NKD1 knockout significantly reduced glucose uptake in colon cancer cells (P < 0.01), while YWHAE overexpression restored the glucose uptake in NKD1-knockout cells (P < 0.05).@*CONCLUSION@#NKD1 protein activates the transcriptional activity of YWHAE gene to promote glucose uptake in colon cancer cells.

Effect of nano-TiO2 on intestinal glucose absorption in young rat on the everted gut sac model / 北京大学学报(医学版)

Objective: To study the effect of titanium dioxide (TiO2) nanoparticles on intestinal glucose absorption in young rats and its size effect.Methods: In the study, 63 small intestine segments were isolated from 63 Sprague-Dawley rats (SD rats, 4-week-old) to prepare the everted gut sac model.In the first part of our work, the everted sacs were exposed to 0, 50 mg/L TiO2 nanoparticles (24 nm) for 2 h with the presence of a series of glucose concentrations (10, 25, 50, 100, 200, 400, and 800 mmol/L), and the glucose absorbing function of the everted sacs were assessed in the process.On the basis of the work, utilizing the same method, further study was carried out to compare the effects of TiO2 nanoparticles (24 nm) and fine-particles (120 nm) on intestinal glucose absorbing function with the presence of 400 mmol/L glucose and 0, 10, 50, 200 mg/L TiO2.3 intestine segments were used in each group.Results: The cumulative glucose absorption increased with time extension and increased glucose concentration.In the first part of our work, with the presence of 400 mmol/L glucose, the group treated with 50 mg/L TiO2 nanoparticles showed significantly lower cumulative glucose absorption and glucose absorbing rate than the control group at the exposure time of 30 min (tcumulative absorption=3.254, P<0.05;tglucose absorbing rate=3.958, P<0.05), 90 min (tcumulative absorption=3.323, P<0.05;tglucose absorbing rate=3.063, P<0.05) and 120 min (tcumulative absorption=2.834, P<0.05;tglucose absorbing rate=3.002, P<0.05).At other glucose concentrations, statistically significant differences in cumulative glucose absorption or glucose absorbing rates were not found between the TiO2 nanoparticle exposed group and the control group.In the second part of our work, when compared with the control group, no significant downregulations in cumulative glucose absorption or glucose absorbing rates were observed in both TiO2 nano-particle treated group and TiO2 fine particle treated group.Differences between the TiO2 nanoparticle treated group and the TiO2 fine particle treated group were not statistically significant.Conclusion: Short-term exposure to TiO2 nanoparticles may downregulate the intestinal glucose absorbing function in young rats, and the difference with TiO2 fine particlesis is not obvious.

Effect of curcumin on glucose absorption: An experimental study on albino rats.

Curcumin derived from the rhizome Curcuma longa is one of the primary ingredient in turmeric. Turmeric is used frequently as food additive in Asia, specially the Indian subcontinent. The daily intake of turmeric in the diet may therefore expose the gut to curcumin and affect its physiological functions, including the absorption of nutrients from small intestine. However, no published reports are available on the effect curcumin on absorption of nutrients from small intestine. To explore this possibility, transport of glucose from small intestine was studied in adult albino rats following feeding the animals curcumin intragastrically for five consecutive days. The controls were fed simultaneously, the vehicular fluid intragastrically in the identical volume. Transport of glucose from small intestine was studied using everted sac technique of Wilson and Wiseman (1954) on animals fasted for 16-20 hrs. Everted sacs were prepared from both jejunal and ileal portion of small intestine. Observations showed a significant increase in glucose transport from jejunal and upper ileal portion of small intestine suggesting that curcumin does influence the transport of nutrients from the gut.

Purificación parcial de un compuesto presente en las hojas de bauhinia megalandra capaz de inhibir la absorción intestinal de glucosa / Partial purification of a compound present in the leaves of Bauhinia megalandra capable of inhibiting intestinal glucose absorption

En la actualidad muchas investigaciones se han volcado al estudio de la actividad biológica de varias plantas que se considera, en el saber de los pueblos, puedan aliviar los síntomas en pacientes con diabetes, tal es el caso de Bauhinia megalandra. El estudio fitoquímico de las hojas de dicha planta se realizó guiado por bioensayos, evaluando el efecto de cada fracción obtenida sobre la absorción intestinal de glucosa con la finalidad de encontrar aquella que presente el mayor efecto inhibitorio sobre dicha actividad biológica, utilizando para su medición segmentos de intestino de rata aislados in situ. Luego de una serie de extracciones secuenciales con diferentes solventes orgánicos y fraccionamiento por cromatografía de columna en silica gel 60, se logró aislar y caracterizar por métodos espectroscópicos una fracción altamente enriquecida con el flavonoide apigenina glucosilada en el carbono ocho. Dicha fracción fue capaz de inhibir la absorción intestinal de glucosa en un 47,34% con respecto al control, y de generar un efecto aditivo cuando se ensayo junto a la floricina

At present, it has been an increase in the research of the biological activity of plants used by the traditional medicine for the empirical treatment of the diabetes mellitus, such as Bauhinia megalandra. The phytochemical study of the leaves of these plants was done guided by bioassay, evaluating the effect of each fraction on the glucose intestinal absorption, using in situ rat intestinal segments. After a sequential series of extractions with organic solvents and fractionation by column chromatographic on silica gel 60, we isolated a fraction characterized by spectroscopic method to be highly enriched in the flavonoid apigenin glicolisated in the carbon eight. This fraction was able to inhibit in a 47,34% the intestinal glucose absorption compared to control, and showed an additive effect when used simultaneously with phloricin

The Role of Glucose Transporter on Peritoneal Glucose Absorption and Fluid Transport / 대한신장학회잡지

PURPOSE: The purpose of this study was to evaluate the role of glucose transporter in peritoneal glucose and fluid transport. METHODS: Male Sprague-Dawley rats were used. 5mL normal saline with(CB) and without(C) Cytochalasin B(1 muM) was intraperitoneally injected once. From the next day 25 mL commercial dialysis solutions containing 4.25% glucose was injected into the peritoneal cavity twice a day for 8 weeks in a half of each group(CB-IP, n=6 and C-IP, n=8). The other half of each group served as control without IP(C- Control, n=7 and CB-Control, n=7). A 2 hour dwell study was performed using dialysis solutions containing 4.25% glucose. Intraperitoneal volume(IPV) after 2 hours of dwell was measured and peritoneal fluid absorption rate(Qa) was calculated as RISA disappearance rate. Dialysate glucose amount remaining after 2hour dwell(DGA) was calculated and expressed as % of the initial value. RESULTS: IPV was significantly higher in CB than in C in both IP and Control. IPV was significantly lower in C-IP than in C-Control and CB-IP while it was similar between CB-Control and CB-IP. Qa was significantly higher in IP than in Control. DGR was significantly higher in CB than in C and in control than in IP. CONCLUSION: Longterm peritoneal exposure to high glucose dialysis solution increased peritoneal glucose absorption and decreased ultrafiltration volume in rat. A single IP use of glucose transporter inhibitor attenuated increased glucose absorption and decreased ultrafiltration after longterm peritoneal exposure to dialysate.

Structural and functional changes in the intestine of irradiated and hypothermic irradiated rats: A scanning and transmission electron microscopic study.

Severe destructive changes in the intestine of rats following whole body exposure to gamma rays (832 rads) were observed by light microscope, scanning and transmission electron microscope studies. Hypothermia (15°C rectal temperature) induced prior to irradiation protected the intestinal mucosa from destruction. A simultaneous study showed that glucose absorption decreased significantly in irradiated rats, whereas it was increased in hypothermic irradiated animals.