Son of sevenless 1 (SOS1), the RasGEF, interacts with ERα and STAT3 during embryo implantation.

Estrogen accounts for several biological processes in the body; embryo implantation and pregnancy being one of the vital events. This manuscript aims to unearth the nuclear role of Son of sevenless1 (SOS1), its interaction with estrogen receptor alpha (ERα), and signal transducer and activator of transcription 3 (STAT3) in the uterine nucleus during embryo implantation. SOS1, a critical cytoplasmic linker between receptor tyrosine kinase and rat sarcoma virus signaling, translocates into the nucleus via its bipartite nuclear localization signal (NLS) during the 'window of implantation' in pregnant mice. SOS1 associates with chromatin, interacts with histones, and shows intrinsic histone acetyltransferase (HAT) activity specifically acetylating lysine 16 (K16) residue of histone H4. SOS1 is a coactivator of STAT3 and a co-repressor of ERα. SOS1 creates a partial mesenchymal-epithelial transition by acting as a transcriptional modulator. Finally, our phylogenetic tree reveals that the two bipartite NLS surface in reptiles and the second acetyl coenzymeA (CoA) (RDNGPG) important for HAT activity emerges in mammals. Thus, SOS1 has evolved into a moonlighting protein, the special class of multi-tasking proteins, by virtue of its newly identified nuclear functions in addition to its previously known cytoplasmic function.

Derailed peripheral circadian genes in polycystic ovary syndrome patients alters peripheral conversion of androgens synthesis.

STUDY QUESTION: Do circadian genes exhibit an altered profile in peripheral blood mononuclear cells (PBMCs) of polycystic ovary syndrome (PCOS) patients and do they have a potential role in androgen excess? SUMMARY ANSWER: Our findings revealed that an impaired circadian clock could hamper the regulation of peripheral steroid metabolism in PCOS women. WHAT IS KNOWN ALREADY: PCOS patients exhibit features of metabolic syndrome. Circadian rhythm disruption is involved in the development of metabolic diseases and subfertility. An association between shift work and the incidence of PCOS in females was recently reported. STUDY DESIGN, SIZE, DURATION: This is a retrospective case-referent study in which peripheral blood samples were obtained from 101 control and 101 PCOS subjects. PCOS diagnoses were based on Rotterdam Consensus criteria. PARTICIPANTS/MATERIALS, SETTING, METHODS: This study comprised 101 women with PCOS and 101 control volunteers, as well as Swiss albino mice treated with dehydroepiandrosterone (DHEA) to induce PCOS development. Gene expression analyses of circadian and steroidogenesis genes in human PBMC and mice ovaries and blood were executed by quantitative real-time PCR. MAIN RESULTS AND THE ROLE OF CHANCE: We observed aberrant expression of peripheral circadian clock genes in PCOS, with a significant reduction in the core clock genes, circadian locomotor output cycles kaput (CLOCK) (P ≤ 0.00001), brain and muscle ARNT-like 1 (BMAL1) (P ≤ 0.00001) and NPAS2 (P ≤ 0.001), and upregulation of their negative feedback loop genes, CRY1 (P ≤ 0.00003), CRY2 (P ≤ 0.00006), PER1 (P ≤ 0.003), PER2 (P ≤ 0.002), DEC1 (P ≤ 0.0001) and DEC2 (P ≤ 0.00005). Transcript levels of an additional feedback loop regulating BMAL1 showed varied expression, with reduced RORA (P ≤ 0.008) and increased NR1D1 (P ≤ 0.02) in PCOS patients in comparison with the control group. We also demonstrated the expression pattern of clock genes in PBMCs of PCOS women at three different time points. PCOS patients also exhibited increased mRNA levels of steroidogenic enzymes like StAR (P ≤ 0.0005), CYP17A1 (P ≤ 0.005), SRD5A1 (P ≤ 0.00006) and SRD5A2 (P ≤ 0.009). Knockdown of CLOCK/BMAL1 in PBMCs resulted in a significant reduction in estradiol production, by reducing CYP19A1 and a significant increase in dihydrotestosterone production, by upregulating SRD5A1 and SRD5A2 in PBMCs. Our data also showed that CYP17A1 as a direct CLOCK-BMAL1 target in PBMCs. Phenotypic classification of PCOS subgroups showed a higher variation in expression of clock genes and steroidogenesis genes with phenotype A of PCOS. In alignment with the above results, altered expression of ovarian core clock genes (Clock, Bmal1 and Per2) was found in DHEA-treated PCOS mice. The expression of peripheral blood core clock genes in DHEA-induced PCOS mice was less robust and showed a loss of periodicity in comparison with that of control mice. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: We could not evaluate the circadian oscillation of clock genes and clock-controlled genes over a 24-h period in the peripheral blood of control versus PCOS subjects. Additionally, circadian genes in the ovaries of PCOS women could not be evaluated due to limitations in sample availability, hence we employed the androgen excess mouse model of PCOS for ovarian circadian assessment. Clock genes were assessed in the whole ovary of the androgen excess mouse model of PCOS rather than in granulosa cells, which is another limitation of the present work. WIDER IMPLICATIONS OF THE FINDINGS: Our observations suggest that the biological clock is one of the contributing factors in androgen excess in PCOS, owing to its potential role in modulating peripheral androgen metabolism. Considering the increasing prevalence of PCOS and the rising frequency of delayed circadian rhythms and insufficient sleep among women, our study emphasizes the potential in modulating circadian rhythm as an important strategy in PCOS management, and further research on this aspect is highly warranted. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the RGCB-DBT Core Funds and a grant (#BT/PR29996/MED/97/472/2020) from the Department of Biotechnology (DBT), India, to M.L. B.S.J. was supported by a DST/INSPIRE Fellowship/2015/IF150361 and M.B.K. was supported by the Research Fellowship from Council of Scientific & Industrial Research (CSIR) (10.2(5)/2007(ii).E.U.II). The authors declare no competing interests. TRIAL REGISTRATION NUMBER: N/A.

Vanadium pentoxide nanoparticle mediated perturbations in cellular redox balance and the paradigm of autophagy to apoptosis.

The redox-active transition metals such as copper, iron, chromium, vanadium, and silica are known for its ROS generation via mechanisms such as Haber-Weiss and Fenton-type reactions. Nanoparticles of these metals induce oxidative stress due to acellular factors owing to their small size and more reactive surface area, leading to various cellular responses. The intrinsic enzyme-like activity of nano vanadium has fascinated the scientific community. However, information concerning their cellular uptake and time-dependent induced effects on their cellular organelles and biological activity is lacking. This comprehensive study focuses on understanding the precise molecular interactions of vanadium pentoxide nanoparticles (VnNp) and evaluate their specific "nano" induced effects on MDA-MB-231 cancer cells. Understanding the mechanism behind NP-induced ROS generation could help design a model for selective NP induced toxicity, useful for cancer management. The study demonstrated the intracellular persistence of VnNp and insights into its molecular interactions with various organelles and its overall effects at the cellular level. Where triple-negative breast cancer MDA-MB-231 cells resulted in 59.6% cell death towards 48 h of treatment and the normal fibroblast cells showed only 15.4% cell death, indicating an inherent anticancer property of VnNp. It acts as an initial reactive oxygen species quencher, by serving itself as an antioxidant, while; it was also found to alter the cellular antioxidant system with prolonged incubation. The VnNp accumulated explicitly in the lysosomes and mitochondria and modulated various cellular processes including impaired lysosomal function, mitochondrial damage, and autophagy. At more extended time points, VnNp influenced cell cycle arrest, inhibited cell migration, and potentiated the onset of apoptosis. Results are indicative of the fact that VnNp selectively induced breast cancer cell death and hence could be developed as a future drug molecule for breast cancer management. This could override the most crucial challenge of chemo-resistance that still remain as the main hurdle to cancer therapy.

Murine uterine decidualization is a novel function of autoimmune regulator-beyond immune tolerance.

PROBLEM: Autoimmune polyendocrinopathy, candidiasis, and ectodermal dystrophy (APECED, APS-1) patients characterized by Aire (autoimmune regulator) mutations and Aire homozygous knockouts (Aire(-/-) ) exhibit infertility. It is not clear as to what contributes to infertility in the above. METHOD OF STUDY: This study investigates the expression of "AIRE in the uterus" and its contribution to early pregnancy of mice by using quantitative real-time PCR analysis, immunohistochemistry, Western blotting, and in vivo Aire silencing experiments. RESULTS: Aire (Isoform 1a) is expressed in the uterus during the "window of implantation" and decidualization. In vivo Aire silencing interfered with formation of implantation sites and stromal cell transformation by regulating bone morphogenetic protein-2,4 (Bmp2, Bmp4), homeobox A10 (Hoxa10), and insulin-like growth factor-binding protein 1(Igfbp1) leading to pregnancy failure. CONCLUSION: Our consolidated results on extrathymic uterine expression of AIRE during early pregnancy and decidualization and impaired fertility on in vivo silencing are suggestive of its importance in pregnancy via a role beyond immune tolerance.

Estrogen-Initiated Protein Interactomes During Embryo Implantation.

Failed implantation is the major restraining factor in assisted reproduction and is defined as the 'black-box of assisted reproduction'. Although work on understanding the complex process of implantation has substantially advanced, it has been limited to studies on mechanism of steroid hormone-mediated signaling during embryo implantation and knocking out single molecules and assessing their impact on embryo implantation. It is important to realize that most proteins exert their function via interaction with other proteins in order to relay downstream signals and/or regulate gene expression via interactions within promoter complexes. Such networks of biomolecular interactions constitute the basis for life as protein interactions are obligatory for cellular functioning. Thus, this review will focus on highlighting protein interactions during the complex process of embryo implantation as they attain a larger significance as pregnancy is fundamental to childbirth and the continuity of life per se.