Biology subjects

Lydon, J. P.

Publications and source records attributed to Lydon, J. P..

6 recordsLinked to original sources

bioRxiv2025

Mechanosensitive channel PIEZO1 enhances endometrial decidualization via BECN1-dependent autophagy

The mechanosensitive ion channel PIEZO1 plays critical roles in physiological and pathological processes in response to various types of mechanical forces, including shear stress, stretch, and extracellular matrix (ECM) stiffness. Decidualization is crucial for a successful pregnancy, characterized by the differentiation of fibroblastic endometrial stromal cells into round, secretory decidual cells, along with the rapid remodeling of the ECM. Herein, we report that PIEZO1 plays a crucial role in enhancing decidualization in response to extracellular matrix (ECM) stiffness and cell contraction. Uterine-specific knockout of Piezo1 using Pgr-Cre in mice results in subfertility due to decidualization impairment in mid-late pregnancy. Silencing of PIEZO1 in human endometrial stromal cells also results in impaired decidualization. Treatment with the PIEZO1 agonist Yoda1 enhances decidualization in both in vivo and in vitro models. Stromal cells growing on ECM with 25 kPa stiffness display a better decidualization response than cells seeded on softer 2 kPa surface or harder surface of the regulator petri dish, and this difference is abolished by null of Piezo1. Consistent with PIEZO1 as a Ca2+ modulator, blocking of intracellular Ca2+ or pCaMKII significantly inhibits Yoda1-enhanced decidualization. Further investigation reveals that BECN1-dependent autophagy acts as the downstream of PIEZO1. Silencing of Beclin1 abolishes Yoda1-induced decidualization, while Tat-BECN1 fully rescues impaired decidualization caused by the lack of PIEZO1. Finally, the lower expression of PIEZO1 is associated with impaired decidualization in the endometrium of endometriotic baboons. In conclusion, we have uncovered a novel mechanism of decidualization that is regulated by PIEZO1-mediated mechanotransduction, providing further insight into decidualization studies. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=187 HEIGHT=200 SRC="FIGDIR/small/668790v1_ufig1.gif" ALT="Figure 1"> View larger version (68K): org.highwire.dtl.DTLVardef@2d25faorg.highwire.dtl.DTLVardef@186e56org.highwire.dtl.DTLVardef@1f3f61borg.highwire.dtl.DTLVardef@1a26bb7_HPS_FORMAT_FIGEXP M_FIG C_FIG

physiology↗

bioRxiv2020

Cell-type specific analysis of physiological action of estrogen in mouse oviducts

One of the endogenous estrogens, 17{beta}-estradiol (E2) is a female steroid hormone secreted from the ovary. It is well established that E2 causes biochemical and histological changes in the uterus. The oviduct response to E2 is virtually unknown in an in vivo environment. In this study, we assessed the effect of E2 on each oviductal cell type, using an ovariectomized-hormone-replacement mouse model, single cell RNA-sequencing (scRNA-seq), in situ hybridization, and cell-type-specific deletion in mice. We found that each cell type in the oviduct responded to E2 distinctively, especially ciliated and secretory epithelial cells. The treatment of exogenous E2 did not drastically alter the transcriptomic profile from that of endogenous E2 produced during estrus. Moreover, we have identified and validated genes of interest in our datasets that may be used as cell- and region-specific markers in the oviduct. Insulin-like growth factor 1 (Igf1) was characterized as an E2-target gene in the mouse oviduct and was also expressed in human Fallopian tubes. Deletion of Igf1 in progesterone receptor (Pgr)-expressing cells resulted in female subfertility, partially due to an embryo developmental defect and embryo retention within the oviduct. In summary, we have shown that oviductal cell types are differentially regulated by E2 and support gene expression changes that are required for normal embryo development and transport in mouse models.

cell biology↗

bioRxiv2020

Identification of a Novel PP2A Regulator, WNK1, as Critical For Uterine Function

WNK1 is an atypical kinase protein ubiquitously expressed in humans and mice. A mutation in its encoding gene causes hypertension in humans which is associated with abnormal ion homeostasis. Our earlier findings demonstrated that WNK1 is critical for in vitro decidualization in human endometrial stromal cells – pointing towards an unrecognized role of WNK1 in female reproduction. Here, we employed a mouse model with conditional WNK1 ablation from the female reproductive tract to define its in vivo role in uterine biology. Loss of WNK1 altered uterine morphology, causing endometrial epithelial hyperplasia, adenomyosis and a delay in embryo implantation, ultimately resulting in compromised fertility. Combining transcriptomic, proteomic and interactomic analyses revealed a novel regulatory pathway whereby WNK1 represses AKT phosphorylation through the phosphatase PP2A in endometrial cells from both humans and mice. We show that WNK1 interacts with PPP2R1A, an isoform of the PP2A scaffold subunit. This interaction stabilizes the PP2A complex, which then dephosphorylates AKT. Therefore, loss of WNK1 reduced PP2A activity, causing AKT hypersignaling. Using FOXO1 as a readout of AKT activity, we demonstrate that there was escalated FOXO1 phosphorylation and nuclear exclusion, leading to a disruption in the regulation of genes that are crucial for embryo implantation.Competing Interest StatementThe authors have declared no competing interest.View Full Text

developmental biology↗

bioRxiv2020

Pten and Dicer1 loss causes poorly-differentiated endometrial adenocarcinoma in mice

Endometrial cancer remains the most common gynecological malignancy in the United States. While the loss of the tumor suppressor, PTEN (phosphatase and tensin homolog), is well studied in endometrial cancer, recent studies suggest that DICER1, the endoribonuclease responsible for miRNA genesis, also plays a significant role in endometrial adenocarcinoma. In an endometrial adenocarcinoma mouse model, which has a conditional uterine deletion of Pten, Dicer1 was also conditionally deleted. Conditional uterine deletion of Dicer1 and Pten resulted in high-penetrance, poorly-differentiated endometrial adenocarcinomas. Poorly-differentiated endometrial adenocarcinomas expressed known markers of clear-cell adenocarcinoma, including Napsin A and HNF1B (hepatocyte nuclear factor 1 homeobox B). Adenocarcinomas were hormone-independent, and treatment with long-term progesterone did not mitigate poorly-differentiated adenocarcinoma, nor did it affect adnexal metastasis. Transcriptomic analyses of uteri or Ishikawa cells with deletion of DICER1 revealed unique transcriptomic profiles and global downregulation of miRNAs. Integration of downregulated miRNAs with upregulated mRNA targets revealed deregulated let-7 and miR-16 target genes, similar to published human DICER1-mutant endometrial cancers from TCGA (The Cancer Genome Atlas). Importantly, these miRNA-target genes, involved in ephrin-receptor and transforming growth factor-beta signaling, represent potential clinical targets for rare, yet deadly, poorly-differentiated endometrial adenocarcinomas in women. This mouse model represents poorly-differentiated endometrial adenocarcinoma and will allow for the discovery of novel mechanisms of hormone-independent endometrial adenocarcinoma from atrophic endometrium. Significance StatementEndometrial cancer is one of the few cancers with an increasing death rate in the United States. The most significant risk factor associated with death is high tumor grade, which occurs most frequently in postmenopausal women, where it develops within an atrophic endometrium. Here, we present a mouse model with conditional deletion of Dicer1, a key enzyme in miRNA genesis, and Pten, a tumor suppressor, that develops poorly-differentiated, steroid hormone-independent, endometrial adenocarcinoma with adnexal metastasis. These high-grade adenocarcinomas develop from an atrophic endometrium and share molecular features with DICER1-mutant human endometrial adenocarcinomas. We anticipate that this preclinical model represents a move toward the discovery of novel mechanisms of hormone-independent development of endometrial adenocarcinoma from atrophic endometrium.

cancer biology↗

bioRxiv2020

Increased FOXL2 Expression Alters Uterine Structures and Functions

Transcription factor FOXL2 exhibits an increase in mRNA levels in eutopic endometrial biopsy in endometriosis patients. While FOXL2 is known of regulating sex differentiation and reproductive function, the impact of elevated FOXL2 expression on uterine physiology remains unknown. To answer this question, we generated mice with over expression of FOXL2 (FOXL2OE) in the female reproductive tract by crossing Foxl2LsL/+ with the Pgrcre model. FOXL2OE uterus showed severe morphological abnormality including abnormal epithelial stratification, blunted adenogenesis, increased endometrial fibrosis and disrupted myometrial morphology. In contrast, increasing FOXL2 levels specifically in uterine epithelium by crossing the Foxl2LsL/+ with the Ltficre mice resulted in the eFOXL2OE mice with uterine epithelial stratification but without defects in endometrial fibrosis and adenogenesis, demonstrating a role of the endometrial stroma in the uterine abnormalities of the FOXL2OE mice. Transcriptomic analysis of 12 weeks old Pgrcre and FOXL2OE uterus at diestrus stage showed a positive correlation of FOXL2OE uterine transcriptome with human endometrium of endometriosis patients. Furthermore, we found FOXL2OE mice were sterile. The infertility was caused in part by a disruption of the hypophyseal ovarian axis resulting in an anovulatory phenotype. The FOXL2OE mice failed to show decidual responses during artificial decidualization in ovariectomized mice which demonstrates the uterine contribution to the infertility phenotype. These data supported that aberrantly increased FOXL2 expressions in the female reproductive tract can disrupt ovarian and uterine functions, particularly, may be involved in the progressions of endometriosis.

developmental biology↗

bioRxiv2019

Constitutive Expression of the Progesterone Receptor Isoforms Promotes Hormone-Dependent Development of Ovarian Neoplasms

Abnormal expression of the progesterone receptor (PGR) isoforms, PGRA and PGRB, is often observed in women with reproductive tract cancer. To assess the importance of the PGR isoform ratio in the maintenance of the healthy reproductive tract, mice with Cre recombinase- activated PGRA and PGRB transgenes were bred with the PGRCre mouse model to generate strains expressing either PGRA or PGRB in PGR positive tissues. The PGRB mice developed ovarian neoplasms at 23 weeks of age derived from ovarian luteal cells, while the PGRA expressing mice displayed a reduced frequency of tumor development. Transcriptomic analyses of the ovarian tumors revealed an enhanced AKT pathway signature, which is in agreement with expression changes found in human ovarian adenocarcinoma. Effective treatment with the PGR antagonist RU486 reduced tumor growth and the expression of cell cycle genes. We concluded that tumor growth and proliferation is hormone and PGR isoform dependent. Further analysis of the PGRB cistrome identified binding events of critical mitotic phase entry genes. This work suggests an intriguing mechanism whereby the expression of the PGR isoforms determines in vivo neoplasia through high-jacking of the cell cycle pathway.

cancer biology↗