The role of estrogen receptors in intestinal homeostasis and disease

Estrogen has a pivotal role in many biological functions in both reproductive and non-reproductive organs, mediating actions through its receptors, estrogen receptor α (ERα) and ERβ. The expression of ERs is widespread in the body and is implicated in normal physiological processes as well as in disease conditions, including intestinal diseases. Immunohistochemical and functional analyses have revealed that ERβ is the predominant ER type in intestinal tract, but not ERα. The ERβ mediates to provide protection against duodenal ulcer, inflammatory bowel disease and colon cancer but may also contribute to the progression of constipation. In this review, we summarize the recent findings regarding estrogen and its receptors and their role in intestinal diseases. Based on these findings, it is possible to drive the pathogenesis of intestinal diseases using ER-subtype selective inhibitors or stimulators

The Effect of Estrogen on Hepatic Fat Accumulation during Early Phase of Liver Regeneration after Partial Hepatectomy in Rats

Fatty liver is common in men and post-menopausal women, suggesting that estrogen may be involved in liver lipid metabolism. The aim of this study is to be clear the role of estrogen and estrogen receptor alpha (ERα) in fat accumulation during liver regeneration using the 70% partial hepatectomy (PHX) model in male, female, ovariectomized (OVX) and E2-treated OVX (OVX-E2) rats. Liver tissues were sampled at 0–48 hr after PHX and fat accumulation, fatty acid translocase (FAT/CD36), sterol regulatory element-binding protein (SREBP1c), peroxisome proliferator-activated receptor α (PPARα), proliferative cell nuclear antigen (PCNA) and ERα were examined by Oil Red O, qRT-PCR and immunohistochemistry, respectively. Hepatic fat accumulation was abundant in female and OVX-E2 compared to male and OVX rats. FAT/CD36 expression was observed in female, OVX and OVX-E2 at 0–12 hr after PHX, but not in male rats. At 0 hr, SREBP1c and PPARα were elevated in female and male rats, respectively, but were decreased after PHX in all rats. The PCNA labeling index reached a maximum at 36 hr and 48 hr in OVX-E2 and OVX rats, respectively. ERα expression in OVX-E2 was higher than OVX at 0–36 hr after PHX. In conclusion, these results indicated that estrogen and ERα might play an important role in fat accumulation related to FAT/CD36 during early phase of rat liver regeneration.Citation: Srisowanna N, Choijookhuu N, Yano K, Batmunkh B, Ikenoue M, Nhat Huynh Mai N, Yamaguchi Y, Hishikawa Y. The Effect of Estrogen on Hepatic Fat Accumulation during Early Phase of Liver Regeneration after Partial Hepatectomy in Rats. Acta Histochem Cytochem. 2019 Aug 30;52(4):67-75. doi: 10.1267/ahc.19018. Epub 2019 Aug 27. PMID: 31592200; PMCID: PMC6773610