Estrogen-induced Tgfbr1 and Bmpr1a Expression Repressed via Estrogen Receptor Beta in MC3T3-E1 Cells

WFDC3 inhibits tumor metastasis by promoting the ERβ-mediated transcriptional repression of TGFBR1 in colorectal cancer

Estrogen plays a protective role in colorectal cancer (CRC) and primarily functions through estrogen receptor β (ERβ). However, clinical strategies for CRC therapy associated with ERβ are still under investigation. Our discoveries identified WFDC3 as a tumor suppressor that facilitates estrogen-induced inhibition of metastasis through the ERβ/TGFBR1 signaling axis. WFDC3 interacts with ERβ and increases its protein stability by inhibiting its proteasome-dependent degradation. WFDC3 represses TGFBR1 expression through ERβ-mediated transcription. Blocking TGFβ signaling with galunisertib, a drug used in clinical trials that targets TGFBR1, impaired the migration of CRC cells induced by WFDC3 depletion. Moreover, there was clinical significance to WFDC3 in CRC, as CRC patients with high WFDC3 expression in tumor cells had favorable prognoses. Therefore, this work suggests that WFDC3 could be an indicator for therapies targeting the estrogen/ERβ pathway in CRC patients.

Estradiol Ameliorates Acute Kidney Ischemia-Reperfusion Injury by Inhibiting the TGF-βRI-SMAD Pathway

Renal ischemia–reperfusion injury (IRI) is less extensive in females than males in both animals and humans; however, this protection diminishes after menopause, suggesting that estrogen plays a pivotal role in IRI, but the underlying mechanism remains largely unknown. Our study found that 45 min of warm ischemia was sufficient to induce significant pathological changes without causing death in model animals. Compared with male rats, female rats exhibited less extensive apoptosis, kidney injury, and fibrosis; these effects were worsened in ovariectomized (OVX) rats and ameliorated upon estradiol (E₂) supplementation. Furthermore, the levels of TGF-βRI, but not TGF-βRII or TGF-β1, were significantly increased in OVX rats, accompanied by phosphorylated SMAD2/3 activation. Interestingly, the alteration trend of the nuclear ERα level was opposite that of TGF-βRI. Furthermore, dual luciferase reporter and chromatin immunoprecipitation assays showed that ERα could bind to the promoter region of TGF-βRI and negatively regulate its mRNA expression. Moreover, an in vitro study using NRK-52E cells showed that ERα knockdown blocked E₂-mediated protection, while TGF-βRI knockdown protected cells against hypoxic insult. The findings of this study suggest that renal IRI is closely related to the TGF-βRI-SMAD pathway in females and that E₂ exert its protective effect via the ERα-mediated transcriptional inhibition of TGF-βRI expression.

Effect of estradiol on high glucose‑induced osteoblast injury

Estradiol (E2) serves an important role in the changes of postmenopausal bone turnover rate and the development of osteoporosis. The present study aimed to investigate the effects of E2 on high glucose (HG)‑induced osteoblast injury. Cell Counting Kit‑8 was used to determine cell viability. Reverse transcription‑quantitative PCR (RT‑qPCR) and western blotting was used to analyze the mRNA and protein expression levels of osteocalcin, Runt‑related transcription factor 2 (Runx2), nuclear factor E2‑related factor 2 (Nrf2) and heme oxygenase‑1 (HO1). Flow cytometry was performed to analyze apoptosis. The results revealed that cell viability was lower in cells treated with HG (100, 200 or 300 mg/dl) compared with the control group. Cell viability was decreased in cells treated with 200 mg/dl HG on days 3, 5 and 7. In addition, cell viability was increased by 0.1 µM E2. E2 with HG co‑treatment increased cell viability, osteocalcin and Runx2 mRNA expression levels and nuclear Nrf2 and HO1 protein expression levels compared with the HG‑only group. All these changes, with the exception of Runx2, were reversed by silencing Nrf2 expression using small interfering (si)RNA (siNrf2). Additionally, apoptosis was reduced by E2 in HG‑treated cells, which was reversed by siNrf2 transfection. These results demonstrated that E2 may prevent HG‑induced osteoblast injury by activating Nrf2/HO1 signaling pathways.