Olivia Ballard

Aware of the important benefits of human milk, most U.S. women initiate breastfeeding but difficulties with milk supply lead some to quit earlier than intended. Yet, the contribution of maternal physiology to lactation difficulties remains poorly understood. Human milk fat globules, by enveloping cell contents during their secretion into milk, are a rich source of mammary cell RNA. Here, we pair this non-invasive mRNA source with RNA-sequencing to probe the milk fat layer transcriptome during three stages of lactation: colostral, transitional, and mature milk production. The resulting transcriptomes paint an exquisite portrait of human lactation. The resulting transcriptional profiles cluster not by postpartum day, but by milk Na:K ratio, indicating that women sampled during similar postpartum time frames could be at markedly different stages of gene expression. Each stage of lactation is characterized by a dynamic range (10(5)-fold) in transcript abundances not previously observed with microarray technology. We discovered that transcripts for isoferritins and cathepsins are strikingly abundant during colostrum production, highlighting the potential importance of these proteins for neonatal health. Two transcripts, encoding β-casein (CSN2) and α-lactalbumin (LALBA), make up 45% of the total pool of mRNA in mature lactation. Genes significantly expressed across all stages of lactation are associated with making, modifying, transporting, and packaging milk proteins. Stage-specific transcripts are associated with immune defense during the colostral stage, up-regulation of the machinery needed for milk protein synthesis during the transitional stage, and the production of lipids during mature lactation. We observed strong modulation of key genes involved in lactose synthesis and insulin signaling. In particular, protein tyrosine phosphatase, receptor type, F (PTPRF) may serve as a biomarker linking insulin resistance with insufficient milk supply. This study provides the methodology and reference data set to enable future targeted research on the physiological contributors of sub-optimal lactation in humans.

Milk fat globules (MFG) contain cytoplasmic crescents, which are a rich source of lactocyte mRNA. Our aim was to characterize the transcriptome of washed human MFG using Next Generation Sequencing (NGS). Fresh milk was collected from 7 predominately breastfeeding women (2–172 d postpartum) and centrifuged at 15,000g for 10 minutes. The lipid layer was washed twice in PBS to purify the MFG. Poly(A)RNA was extracted and sequenced (Illumina HiSeq2000), averaging 15.3 million 50bp single reads per sample; 27,294 unique transcript variants were expressed, comprising 16,924 unique genes. Blind clustering analysis revealed a distinct transcriptional profile for the participant recovering from mastitis. Functional analyses revealed key genes expressed in the lactocyte that are not yet functionally annotated. The unprecedented dynamic range of NGS enabled us to determine that the top 5 abundant milk protein genes contribute 40% of the mRNA, suggesting that minor abundance transcripts may not be actively down‐regulated by altered transcription factor binding or chromatin modification, but instead by dilution, a mechanism by which lactocytes could dramatically alter phenotype by active up‐regulation of a few key genes. As the first NGS of the human MFG, these data will inform future applications of this powerful tool in lactation research. Funded by Cincinnati Diabetes and Obesity Center (LAN‐R) and NICHD (ALM).

Acute Flaccid Myelitis (AFM) awareness is expanding in pediatric intensive care units(PICU) around the world. The underlying etiology and protocols of management remain unclear to many medical professionals today. As of 2014, a correlation to the disease is associated with an enterovirus pathology. Unfortunately, its presentation can be easily missed and lead to detrimental outcomes. The mysterious polio-like disease leaves the patient in a state of paralysis, frequently requiring feeding and ventilatory support. With the lack of scientific knowledge and surveillance in the hospital, clinicians and nurses feel guilt in not knowing if AFM was missed. As new research continues to develop, the healthcare system and the Center for Disease Control (CDC) require a sustained pursuit to cure and prevent this devastating illness from affecting the lives of innocent children. The author intends to inform and educate individuals on the need for immediate awareness of AFM and protocols for treatment to be established with its known etiologies thus far.