Background/Aims: Excess fibrosis may lead to chronic pain, scarring, and infertility as endometriosis develops and progresses. The pathogenesis of endometriosis has been linked to transforming growth factor-β (TGF-β), the most potent promoter of fibrosis. Methods: Levels of NR4A1 and P-NR4A1 protein in human endometrial and endometriotic tissue were assessed by western blotting and immunohistochemistry. The expression levels of fibrotic markers in stromal cells were evaluated by real-time PCR. The degree of fibrosis in mouse endometriotic lesions was detected by Masson trichrome and Sirius red staining. Results: The level of phosphorylated-NR4A1 was higher in ovarian endometriotic tissue than in normal endometrium, and long-term TGF-β1 stimulation phosphorylated NR4A1 in an AKT-dependent manner and then promoted the expression of fibrotic markers. Furthermore, inhibition of NR4A1 in stromal cells increased the TGF-β1-dependent elevated expression of fibrotic markers, and loss of NR4A1 stimulated fibrogenesis in mice with endometriosis. Additionally, Cytosporone B (Csn-B), an NR4A1 agonist, effectively decreased the TGF-β1-dependent elevated expression of fibrotic markers in vitro and significantly inhibited fibrogenesis in vivo. Conclusion: NR4A1 can regulate fibrosis in endometriosis and may serve as a new target for the treatment of endometriosis
Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality worldwide. Orphan nuclear receptor Nur77, which is low expressed in HCC, functions as a tumor suppressor to suppress HCC. However, the detailed mechanism is still not well understood. Here, we demonstrate that Nur77 could inhibit HCC development via transcriptional activation of the lncRNA WAP four-disulfide core domain 21 pseudogene (WFDC21P). Nur77 binds to its response elements on the WFDC21P promoter to directly induce WFDC21P transcription, which inhibits HCC cell proliferation, tumor growth, and tumor metastasis both in vitro and in vivo. In clinical HCC samples, WFDC21P expression positively correlated with that of Nur77, and the loss of WFDC21P is associated with worse prognosis. Mechanistically, WFDC21P could inhibit glycolysis by simultaneously interacting with PFKP and PKM2, two key enzymes in glycolysis. These interactions not only abrogate the tetramer formation of PFKP to impede its catalytic activity but also prevent the nuclear translocation of PKM2 to suppress its function as a transcriptional coactivator. Cytosporone-B (Csn-B), an agonist for Nur77, could stimulate WFDC21P expression and suppress HCC in a WFDC21P-dependent manner. Therefore, our study reveals a new HCC suppressor and connects the glycolytic remodeling of HCC with the Nur77-WFDC21P-PFKP/PKM2 axis.