Molecular mechanisms for regulation of volume and nutrient content of human milk and their relationship with infant growth - PROJECT SUMMARY: My research proposal addresses the critical health issue of insufficient human milk production. Only a quarter of mothers in the U.S. meet recommended breastfeeding targets, resulting in significant costs and infant mortality. Low milk production is a prevalent reason for early cessation of breastfeeding, yet the physiological factors contributing to this problem remain poorly understood, and as a result diagnosis markers and treatments are limited. This proposal utilizes my molecular biology expertise, in conjunction with clinical studies, to illuminate the physiological and transcriptional aspects of human milk production regulation. In my preliminary work, I generated genomic datasets, including bulk RNA-seq and single cell (sc) RNA-seq, from human milk samples obtained from a cohort of individuals with low, normal, and high milk production and found several differentially expressed genes, including a yet to be characterized gene called C6orf15. In this proposal, I will characterize the function of C6orf15 using cell line and mouse models to understand how it is involved in increasing milk production. Using samples collected from a cohort of breastfeeding mothers I will explore the factors influencing infant weight gain by conducting a comprehensive analysis, including a 24-hour test weighing and milk composition. In addition, I will use transcriptomic profiling of mammary gland to identify additional markers and better understand the molecular changes under low milk production. In my independent phase of this award, I will characterize the efficiency of commonly used breast pumping protocols to increase milk supply. A randomized controlled trial will determine the optimal frequency of pumping required to enhance milk production and will also determine if lower frequency of pumping increases compliance of mothers to the protocol and leads to a better breastfeeding experience and longer breastfeeding duration. Finally, I will identify molecular and cellular mechanisms that lead to the observed increased milk production through bulk RNA-seq on samples collected before and after intervention and will be analyzing milk composition (inflammation markers, milk maturation, and macronutrient) and hormonal regulation. This work will uncover the changes in the mammary gland transcriptome and milk composition under different pumping protocols. In summary, my application combines clinical and molecular studies to shed light on the factors influencing human milk production. The results will improve the diagnosis and treatment of insufficient milk production, addressing a significant women's health issue with far-reaching implications for infant and maternal well-being.
