Congratulations to Erwei Li and Yangmian Yuan—their study showing that oxytocin-mediated lipolysis in white adipocytes is required for normal milk fat production is out in Cell Metabolism (https://pubmed.ncbi.nlm.nih.gov/41997158/). Working with collaborators Brigid Gregg and Dave Bridges at the University of Michigan, Erwei and Yangmian found that female mice lacking OXT receptors in adipocytes gave birth to pups with reduced weight gain, and that their milk was deficient in triglycerides. A single-cell analysis of lactating mammary glands without OXT receptors revealed profound changes in metabolic programming of mammary epithelial cells, marked by reduced mTOR signaling, increased autophagy, and reduced lipid synthesis. 

Check out the new preprint (https://doi.org/10.64898/2026.04.09.717542) presenting work led by Zinger Yang Loureiro looking at how adipose tissue composition changes following weight loss surgery.  Zinger finds dramatic remodeling within the first month following surgery, including evidence of apoptosis of older, stressed adipocytes and the creation of new healthy adipocytes through adipogenesis.  

Jessica Felix is a new post-doc in the Rosen lab. Jessica did her graduate work in Sean Hartig’s lab at Baylor College of Medicine, where she did outstanding work to identify N-acetylaspartate as an adipocyte-derived metabolite that regulates body temperature (https://pubmed.ncbi.nlm.nih.gov/40702167/). Welcome, Jessica!

The Rosen Lab is bidding a fond farewell to Greg Westcott and Winnie Zhang as 2025 draws to a close.

Greg’s leadership has been instrumental in advancing our knowledge on lymphedema, while Winnie’s tenacity have been the driving force in bringing the IRS1 project to a successful completion. It has been a privilege to work alongside them. As they move into the industry sector, we know they will continue to do great things. We wish you the very best!

Please check out the new paper from the Rosen lab (working in collaboration with Randy Seeley’s group at the University of Michigan) about changes in adipose tissue after two different weight loss strategies in mice. Margo Emont compared white adipose tissue from obese mice that received either vertical sleeve gastrectomy (VSG) or semaglutide. Some important changes in gene expression and cellular composition were conserved across weight loss interventions, while others were specific to either semaglutide or VSG. Margo also found that some gene expression programs in adipocytes reverted to a chow-like state after weight loss, while others remained “locked” in the obese pattern. link

Greg’s latest paper is available on BioRxiv. Using unique intra-patient controls, he shows that the adipose tissue of chronic lymphedema has a different complement of adipose stromal and progenitor cells (ASPCs), which confer a more pro-adipogenic and pro-lymphangiogenic environment.  https://www.biorxiv.org/content/10.1101/2025.02.18.638907v1