17β-Estradiol reduces inflammation and modulates antioxidant enzymes in colonic epithelial cells

Background/Aims@#Estrogen is known to have protective effect in colorectal cancer development. The aims of this study are to investigate whether estradiol treatment reduces inflammation in CCD841CoN, a female human colonic epithelial cell line and to uncover underlying mechanisms of estradiol effects. @*Methods@#17β-Estradiol (E2) effect was measured by Western blot after inducing inf lammation of CCD841CoN by tumor necrosis factor α (TNF-α). Expression levels of estrogen receptor α (ERα) and β (ERβ), cyclooxygenase-2 (COX-2), nuclear factor-κB (NF-κB), heme oxygenase-1 (HO-1), and NAD(P)H-quinone oxidoreductase-1 (NQO-1) were also evaluated. @*Results@#E2 treatment induced expression of ERβ but did not increase that of ERα. E2 treatment for 48 hours significantly elevated the expression of anti-oxidant enzymes, HO-1 and NQO-1. TNF-α treatment significantly increased the level of activated NF-κB (p < 0.05), and this increase was significantly suppressed by treatment of 10 nM of E2 (p < 0.05). E2 treatment ameliorated TNF-α-induced COX-2 expression and decrease of HO-1 expression. 4-(2-phenyl-5,7-bis(trifluoromethyl) pyrazolo(1,5-a)pyrimidin-3-yl)phenol (PHTPP), antagonist of ERβ, removed the inhibitory effect of E2 in the TNF-α-induced COX-2 expression (p = 0.05). @*Conclusions@#Estrogen seems to inhibit inflammation in female human colonic epithelial cell lines, through down-regulation of NF-κB and COX-2 expression and induction of anti-oxidant enzymes such as HO-1 and NQO-1.

Sex-related Alterations of Gut Microbiota in the C57BL/6 Mouse Model of Inflammatory Bowel Disease

BACKGROUND: Gut microbiota is closely associated with development and exacerbation of inflammatory bowel diseases (IBD). The aim of this study was to investigate differences in gut microbiota depending on sex and changes of gut microbiota during IBD developments. METHODS: 16s rRNA metagenomic sequencing was performed for fecal materials from 8-week-old wild type (WT) and interleukin 10 (IL-10) knockout (KO) C57BL/6 mice of both sexes. Diversity indices, relative abundance of microbiota, and linear discriminant analysis effect size were examined to compare microbial communities between groups. Clustering of groups was performed by principal coordinates analysis (PCoA) and unweighted pair group method with arithmetic mean (UPGMA). Functional capabilities of microbiota were estimated using phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) based on Kyoto Encyclopedia of Genes and Genomes database. RESULTS: PCoA and UPGMA tree analysis of beta-diversity demonstrated significant differences in gut microbiota between male and female groups of WT mice, but not of IL-10 KO mice. Firmicutes to Bacteroides ratio was higher in male group than that in female group in both WT mice and IL-10 KO mice. Phylum Proteobacteria significantly increased in female IL-10 KO mice than that in female WT mice. At species level, Lactobacillus murinus, Bacteroides acidifaciens, and Helicobacter hepaticus significantly increased in IL-10 KO mice than in WT mice. The relative abundance of beta-glucuronidase (K01195) was higher in female IL-10 KO mice than that in female WT mice by PICRUSt. CONCLUSIONS: Our results suggest that microbiota-host interactions might differ between sexes during development of IBD.

Effect of Estradiol in an Azoxymethane/Dextran Sulfate Sodium-Treated Mouse Model of Colorectal Cancer: Implication for Sex Difference in Colorectal Cancer Development / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: This study demonstrates that estradiol downregulates inflammation and inhibits colorectal cancer (CRC) development in azoxymethane/dextran sulfate sodium (AOM/DSS) mouse model. MATERIALS AND METHODS: AOM/DSS-treated male and female mice were sacrificed at weeks 2, 10, and 16, to assess estrogen effects on colitis and carcinogenesis. Macroscopic and histologic severity of colitis and Western blot and quantitative real-time polymerase chain reaction were evaluated, to measure inflammatory mediators and cytokines. RESULTS: Compared with AOM/DSS-treated male mice (M-AOM/DSS group), AOM/DSS-treated male mice with estradiol administration (M-AOM/DSS+estr group) displayed at week 2 significantly decreased severity of colitis. At weeks 10 and 16, AOM/DSS-treated female mice (F-AOM/DSS group) and the M-AOM/DSS+estr group showed significantly lower tumor multiplicity compared with the M-AOM/DSS group. At week 2, F-AOM/DSS group had a lower level of nuclear factor-κB (NF-κB) expression and higher level of nuclear factor erythroid 2-related factor 2 (Nrf2) expression, compared to the M-AOM/DSS group. At week 2, expression levels of NF-κB and its related mediators decreased in the M-AOM/DSS+estr group, while levels of Nrf2 and Nrf2-related anti-oxidant enzymes increased. In addition, estradiol significantly increased Nod-like receptor protein 3 (NLRP3) inflammasome expressions in AOM/DSS-treated male mice. In contrast, at weeks 10 and 16, Nrf2 and its-related anti-oxidant enzymes and NLRP3 inflammasome were highly expressed in M-AOM/DSS group and in F-AOM/DSS group, who developed cancer. CONCLUSION: The data suggest that estradiol inhibits the initiation of CRC by regulating Nrf2-related pathways. Moreover, these imply the dual role of Nrf2 and NLRP3 inflammasome, including promotion of tumor progression upon tumor initiation.

The Effect of Sex on the Azoxymethane/Dextran Sulfate Sodium-treated Mice Model of Colon Cancer

BACKGROUND: The colitis-associated cancer exhibits different characteristics according to sex in the initiation and progression of the tumors. The aim of this study was to investigate the sex-associated difference in the azoxymethane/dextran sulfate sodium (AOM/DSS)-induced colitis-associated cancer model. METHODS: The AOM/DSS ICR mouse model was established to compare male with female, and then the severity of colitis-associated carcinogenesis was examined macroscopically and histologically regarding the number, size, and location of tumors. Subsequently, levels of colonic mucosal cytokine, interleukin (IL)-1β and myeloperoxidase (MPO) were assessed. RESULTS: At the 16th week, the tumor multiplicity and the pro-inflammatory factors differed according to sex. The total tumor number was significantly higher in male (P = 0.020) and the number of large tumors (diameter > 2 mm) was higher in male (P = 0.026). In male, the tumors located more in distal colon (P = 0.001). MPO was significantly higher in AOM/DSS-treated male mice compared to the control group (P = 0.003), whereas the corresponding female group showed no significant change (P = 0.086). Colonic IL-1β level significantly increased in AOM/DSS groups compared to control groups both in male and female (male, P = 0.014; female, P = 0.005). It was higher in male group; however, there was no statistical significance (P = 0.226). CONCLUSIONS: In AOM/DSS murine model, colitis-associated colon tumorigenesis are induced more severely in male mice than female probably by way of inflammatory mediators such as IL-1β and MPO. The sex-related differences at the animal model of colon cancer suggest the importance of approach to disease with sex-specific medicine in human.