Updated adolescent diagnostic criteria for polycystic ovary syndrome: impact on prevalence and longitudinal body mass index trajectories from birth to adulthood

Background: Polycystic ovary syndrome (PCOS) is challenging to diagnose. While the 2003 Rotterdam criteria are widely used for adults, the 2018 international PCOS guideline recommended updated Rotterdam criteria with both hyperandrogenism and oligo-anovulation for adolescents based on evidence-informed expert consensus. This study compared the prevalence of PCOS using updated and original Rotterdam criteria in community-based adolescents and explored long-term body mass index (BMI) trajectories across different diagnostic phenotypes. Methods: Overall, 227 postmenarchal adolescent females from the prospective cohort Raine Study undertook comprehensive PCOS assessment at age 14–16 years. Detailed anthropometric measurements were collected from birth until age 22 years. Cross-sectional and longitudinal BMI were analyzed using t tests and generalized estimating equations. Results: PCOS was diagnosed in 66 (29.1%) participants using original criteria versus 37 (16.3%) participants using updated Rotterdam criteria. Using updated criteria, participants with PCOS had higher BMI than participants without PCOS from prepubertal. Only the phenotype meeting the updated criteria was significantly associated with higher long-term BMI gain whereas other PCOS phenotypes had similar BMI trajectories to participants without PCOS (p < 0.001). Conclusions: The use of the 2018 updated Rotterdam criteria reduces over-diagnosis of PCOS in adolescents and identifies those at the greatest risk of long-term weight gain, a key contributor to disease severity and long-term health implications. The BMI trajectories of females with PCOS on updated criteria diverge prepubertally compared to those without PCOS. This work supports targeting adolescents diagnosed with PCOS on the 2018 updated criteria for early lifestyle interventions to prevent long-term health complications.Chau Thien Tay, Roger J. Hart, Martha Hickey, Lisa J. Moran, Arul Earnest, Dorota A. Doherty, Helena J. Teede and Anju E. Joha

Setdb1-mediated H3K9 methylation is enriched on the inactive X and plays a role in its epigenetic silencing

Background: The presence of histone 3 lysine 9 (H3K9) methylation on the mouse inactive X chromosome has been controversial over the last 15 years, and the functional role of H3K9 methylation in X chromosome inactivation in any species has remained largely unexplored. Results: Here we report the first genomic analysis of H3K9 di- and tri-methylation on the inactive X: we find they are enriched at the intergenic, gene poor regions of the inactive X, interspersed between H3K27 tri-methylation domains found in the gene dense regions. Although H3K9 methylation is predominantly non-genic, we find that depletion of H3K9 methylation via depletion of H3K9 methyltransferase Set domain bifurcated 1 (Setdb1) during the establishment of X inactivation, results in failure of silencing for around 150 genes on the inactive X. By contrast, we find a very minor role for Setdb1-mediated H3K9 methylation once X inactivation is fully established. In addition to failed gene silencing, we observed a specific failure to silence X-linked long-terminal repeat class repetitive elements. Conclusions: Here we have shown that H3K9 methylation clearly marks the murine inactive X chromosome. The role of this mark is most apparent during the establishment phase of gene silencing, with a more muted effect on maintenance of the silent state. Based on our data, we hypothesise that Setdb1-mediated H3K9 methylation plays a role in epigenetic silencing of the inactive X via silencing of the repeats, which itself facilitates gene silencing through alterations to the conformation of the whole inactive X chromosome.Andrew Keniry, Linden J. Gearing, Natasha Jansz, Joy Liu, Aliaksei Z. Holik, Peter F. Hickey, Sarah A. Kinkel, Darcy L. Moore, Kelsey Breslin, Kelan Chen, Ruijie Liu, Catherine Phillips, Miha Pakusch, Christine Biben, Julie M. Sheridan, Benjamin T. Kile, Catherine Carmichael, Matthew E. Ritchie, Douglas J. Hilton and Marnie E. Blewit

BAF complex-mediated chromatin relaxation is required for establishment of X chromosome inactivation

The process of epigenetic silencing, while fundamentally important, is not yet completely understood. Here we report a replenishable female mouse embryonic stem cell (mESC) system, Xmas, that allows rapid assessment of X chromosome inactivation (XCI), the epigenetic silencing mechanism of one of the two X chromosomes that enables dosage compensation in female mammals. Through a targeted genetic screen in differentiating Xmas mESCs, we reveal that the BAF complex is required to create nucleosome-depleted regions at promoters on the inactive X chromosome during the earliest stages of establishment of XCI. Without this action gene silencing fails. Xmas mESCs provide a tractable model for screen-based approaches that enable the discovery of unknown facets of the female-specific process of XCI and epigenetic silencing more broadly.Andrew Keniry ... Jose M. Polo ... et al

Genotoxic effect induced by hydrogen peroxide in human hepatoma cells using comet assay

Background: Hydrogen peroxide is a common reactive oxygen intermediate generated by variousforms of oxidative stress. Aims: The aim of this study was to investigate the DNA damage capacity ofH2O2 in HepG2 cells. Methods: Cells were treated with H2O2 at concentrations of 25 μM or 50 μM for5 min, 30 min, 40 min, 1 h or 24 h in parallel. The extent of DNA damage was assessed by the cometassay. Results: Compared to the control, DNA damage by 25 μM and 50 μM H2O2 increasedsignificantly with increasing incubation time up to 1 h, but it was not increased at 24 h. Conclusions:Our Findings confirm that H2O2 is a typical DNA damage inducing agent and thus is a good modelsystem to study the effects of oxidative stress. DNA damage in HepG2 cells increased significantlywith H2O2 concentration and time of incubation but later decreased likely due to DNA repairmechanisms and antioxidant enzyme