Cellular atlases of ovarian microenvironment alterations by diet and genetically-induced obesity

Obesity,which can arise from genetic or environmental factors,has been shown to cause serious damages to the reproductive system.The ovary,as one of the primary regulators of female fertility,is a complex organ comprised of heterogeneous cell types that work together to maintain a normal ovarian microenvironment(OME).Despite its importance,the effect of obesity on the entire ovary remains poorly documented.In this study,we performed ovary single-cell and nanoscale spatial RNA sequencing to investigate how the OME changed under different kinds of obesity,including high-fat diet(HFD)induced obesity and Leptin ablation induced obesity(OB).Our results demonstrate that OB,but not HFD,dramatically altered the proportion of ovarian granulosa cells,theca-interstitial cells,luteal cells,and endothelial cells.Furthermore,based on the spatial dynamics of follicular development,we defined four subpopulations of granulosa cell and found that obesity drastically disrupted the differentiation of mural granulosa cells from small to large antral follicles.Functionally,HFD enhanced follicle-stimulating hormone(FSH)sensitivity and hormone conversion,while OB caused decreased sensitivity,inadequate steroid hormone conversion,and impaired follicular development.These differences can be explained by the differential expression pattern of the transcription factor Foxo1.Overall,our study provides a powerful and high-resolution resource for profiling obesity-induced OME and offers insights into the diverse effects of obesity on female reproductive disorders.

Freeze-induced acceleration of iodide oxidation and consequent iodination of dissolved organic matter to form organoiodine compounds

Freeze-induced acceleration of I–oxidation and the consequent iodination of dissolved organic matter(DOM)contribute to the formation of organoiodine compounds(OICs)in cold regions.The formed OICs may be a potentially important source of risk and are very closely with the environment and human health.Herein,we investigated the acceleration effects of the freeze process on I–oxidation and the formation of OICs.In comparison to reactive iodine species(RIS)formed in aqueous solutions,I–oxidation and RIS formation were greatly enhanced in frozen solution and were affected by pH,and the content of I–and O_(2).Freeze-thaw process further promoted I–oxidation and the concentration of RIS reached 45.7μmol/L after 6 freeze-thaw cycles.The consequent products of DOM iodination were greatly promoted in terms of both concentration and number.The total content of OICs ranged from 0.02 to 2.83μmol/L under various conditions.About 183–1197 OICs were detected by Fourier transform ion cyclotron resonance mass spectrometry,and more than 96.2%contained one or two iodine atoms.Most OICs had aromatic structures and were formed via substitution and addition reactions.Our findings reveal an important formation pathway for OICs and shed light on the biogeochemical cycling of iodine in the natural aquatic environment.

DENND1A desensitizes granulosa cells to FSH by arresting intracellular FSHR transportation

Polycystic ovary syndrome(PCOS)is a complex disorder.Genome-wide association studies(GWAS)have identified several genes associated with this condition,including DENND1A.DENND1A encodes a clathrin-binding protein that functions as a guanine nucleotide exchange factor involved in vesicular transport.However,the specific role of DENND1A in reproductive hormone abnormalities and follicle development disorders in PCOS remain poorly understood.In this study,we investigated DENND1A expression in ovarian granulosa cells(GCs)from PCOS patients and its correlation with hormones.Our results revealed an upregulation of DENND1A expression in GCs from PCOS cases,which was positively correlated with testosterone levels.To further explore the functional implications of DENND1A,we generated a transgenic mouse model overexpressing Dennd1a(TG mice).These TG mice exhibited subfertility,irregular estrous cycles,and increased testosterone production following PMSG stimulation.Additionally,the TG mice displayed diminished responsiveness to FSH,characterized by smaller ovary size,less well-developed follicles,and abnormal expressions of FSH-priming genes.Mechanistically,we found that Dennd1a overexpression disrupted the intracellular trafficking of follicle stimulating hormone receptor(FSHR),promoting its internalization and inhibiting recycling.These findings shed light on the reproductive role of DENND1A and uncover the underlying mechanisms,thereby contributing valuable insights into the pathogenesis of PCOS and providing potential avenues for drug design in PCOS treatment.