Integrated 'omics analysis reveals human milk oligosaccharide biosynthesis programs in human lactocytes

Area of Science:

• Biochemistry
• Genomics
• Lactation Biology

Background:

• Human milk oligosaccharides (HMOs) are vital bioactive compounds for infant gut health and development.
• The intricate molecular mechanisms and cellular regulation governing HMO biosynthesis in the mammary gland are not fully elucidated.

Purpose of the Study:

• To investigate the cellular and molecular basis of HMO biosynthesis during lactation.
• To identify novel genes, transcription factors, and cellular pathways involved in HMO production.
• To explore the relationship between HMO synthesis and other milk component production pathways.

Main Methods:

• Integrated analysis of single-cell RNA-sequencing (scRNA-seq) data from mammary epithelial cells.
• Correlation of gene expression patterns with measured HMO concentrations in milk.
• Bioinformatic identification of differentially expressed genes and regulatory elements.

Main Results:

• Identified distinct expression patterns of HMO synthesis genes across epithelial cell subsets.
• Nominated candidate genes and transcription factors potentially regulating HMO biosynthesis.
• Revealed limited co-expression of HMO and milk fat synthesis genes, suggesting functional specialization.
• Demonstrated cell type specialization within lactocytes for producing different milk components, including HMOs.

Conclusions:

• HMO biosynthesis involves complex gene regulation and potentially specialized epithelial cell subtypes within the mammary gland.
• Cellular specialization may optimize the production of diverse milk components, including HMOs and lipids.
• This research provides a foundation for understanding the cellular control of HMO production and its implications for infant nutrition.