Sex-differences in Hematopoietic Stem/progenitor Cell Function and Transcriptome in Offspring of Obese Mice

Merve Denizli, Indiana University School of Medicine, Fishers, IN, United States; James Ropa, Indiana University School of Medicine, United States; Lindsay N. Beasley, Indiana University School of Medicine, United States; Laura Haneline, Indiana University School of Medicine; Riley Children’s Hospital, United States; Maegan Capitano, Indiana University School of Medicine, United States; Kok Lim Kua, Indiana University School of Medicine, United States

Background: Maternal obesity is increasingly common and can negatively impact offspring health. Children born to mothers who are obese are more likely to suffer from diseases such as neuropsychiatric disorders, allergy/asthma, and leukemia. Many of these diseases have altered immune profiles or hematopoiesis with sex-differences in risks, suggesting the sex-specific reprogramming of hematopoietic stem and progenitor cells (HSPC). However, the sex-differences in offspring HSPC function and the related mechanisms have not been studied.

Objectives: The objective of this study is to test the hypothesis that offspring of obese mice exhibit sex-differences in HSPC function with associated transcriptome changes.

Design/Methods: Female dams were fed with chow (Con) or western diet (MatOb) for four weeks prior to mating, through pregnancy, and the lactating period. At postnatal day 21 (P21), HSPC (Lin- Sca-1+ cKit+) was flow-sorted from offspring bone marrow (BM) for competitive transplant to assess HSPC function and RNA isolation for RNA-seq. Differentially expressed genes (DEG) were determined using DESeq2 with an adjusted p-value < 0.05 and subjected to pathway analysis using IPA.

Results: The competitive repopulation assay revealed that LSK-enriched cells from male MatOb pups had higher donor chimerism 16 weeks following primary transplantation compared to male Con pups, while donor chimerism of LSK-enriched cells from female pups was unchanged. Following the secondary transplant, recipient mice of male MatOb donor cells had significantly lower donor chimerism at 4 and 16 weeks, and lower donor LT-HSC in the bone marrow at 16 weeks indicating male MatOb LSK had decreased function to prolonged stress. (n ≥5 mice from ≥3 litters/group). Compared to sex-matched Con, RNAseq revealed 8 up- and 92 down-regulated genes in male MatOb HSPC, and 823 up- and 965 downregulated genes in female MatOb HSPC (n=6/sex/group). Pathway analysis showed common enriched pathways related to metabolism and hematopoiesis. Interestingly, interferon-alpha and IL-10 was predicted as the upstream regulator in female MatOb pups, and only IL-10 protein was found to be higher in female MatOb BM supernatant (n=3/sex/group).

Conclusion: Our data demonstrates that offspring of obese mice have altered HSPC function and altered transcriptome in a sex-specific manner. Differences in IL-10 within BM potentially contribute to the differences in altered transcriptome.