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

Area of Science:

• Lactation Biology
• Molecular Endocrinology
• Human Milk Composition

Background:

• Human milk oligosaccharides (HMOs) are crucial for infant development and immunity.
• The intricate biosynthesis pathways of HMOs within the mammary gland are not fully understood.
• Understanding HMO production is key to leveraging their health benefits.

Purpose of the Study:

• To elucidate the molecular mechanisms and cellular basis of HMO biosynthesis during lactation.
• To identify novel genes and regulatory factors involved in HMO production.
• To investigate the relationship between HMO synthesis and other milk component production.

Main Methods:

• Integrated analysis of single-cell RNA-sequencing (scRNA-seq) data.
• Correlation of gene expression patterns with HMO concentration measurements.
• Bioinformatic identification of gene expression patterns and transcription factors.

Main Results:

• Differential gene expression of known HMO synthesis genes identified in specific epithelial cell subsets.
• Nomination of candidate genes associated with varying HMO concentrations.
• Identification of novel regulatory factors and pathways influencing HMO biosynthesis.
• Limited co-expression of HMO synthesis and milk fat synthesis genes observed.
• Evidence for cell-type specialization in lactocytes for producing different milk components.

Conclusions:

• HMO synthesis is likely orchestrated by cell-type specialization within the lactocyte population.
• Distinct epithelial cell subtypes may be responsible for producing specific milk components, including HMOs.
• This research provides a foundation for understanding and potentially manipulating HMO production.