I am a professor of obstetrics and gynecology, in particular of reproductive medicine, at Karolinska Institutet, and senior consultant, in charge of gynecological endocrinology, at the Department of Gynecology and Reproductive Medicine, Karolinska University Hospital. My research is focused on disorders of reproductive function and gonadal development in women. My overall research aim is to improve diagnostics, fertility and long-term health in women with strenuous exercise, obesity, polycystic ovary syndrome (PCOS), primary ovarian insufficiency (POI) and disorders of sex development (DSD). PCOS is the most common endocrine disorder in women of reproductive age, characterized by hyperandrogenism, oligo-anovulation, and metabolic dysregulation. Adipose tissue dysfunction is a driver of the systemic insulin resistance and chronic low-grade inflammation that signifies the PCOS phenotype. However, the cell-type-specific molecular mechanisms underlying adipose tissue pathology in PCOS remain poorly understood. Moreover lifestyle modification and weight loss has shown to improve all symtoms of PCOS but the precise molecular mechanism has not been studied in molecular detail. This project will use single-cell transcriptomics to deconvolve the cellular heterogeneity of human adipose tissue in women with PCOS who underwent a 4-month structured lifestyle intervention but with divergent metabolic response: weight loss (responders, n=5) or weight gain (non-responders, n=4). By studying gene expression at single-cell resolution, we will identify cell-type-specific disease signatures, map intercellular communication networks, and define the metabolic pathways distinguishing metabolically favourable from metabolically pernicious PCOS adipose tissue. Adipose tissue samples have been collected at both baseline and after 4 months of lifestyle intervention. Resulting in 10 samples of weight loss and 8 samples of weight gain, in total 18 samples.