Mammary gland (MG) is a dynamic organ that is essential for the production and secretion of breast milk. During pregnancy the MG undergoes a critical phase of remodeling, which is accompanied by the differentiation of mammary epithelial cells (MECs). During lactation, the MG requires high level of energy for proper folding of proteins in the secretory pathway, which takes place in the endoplasmic reticulum (ER). Limited evidence has been reported on the impact of cannabis or its components, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), on the differentiation of MECs. However, both THC and CBD have been reported to induce ER stress in various cell types, resulting in impacting cellular function. Furthermore, consequences of cannabis use in the perinatal period on breast milk composition have not been reported. Using the HC11 cell line, we investigated whether THC and CBD evoke ER stress in MECs resulting in the impaired cellular function. We also reported on the effects of cannabis use during pregnancy and lactation on the levels of macronutrients and bioactive factors in the breast milk of cannabis users. Relative to control, 10μM THC and 10μM CBD reduced mRNA levels of milk proteins (CSN2 and WAP) and lipid synthesizing enzymes (FASN, FABP4, PLIN2 and LPL), as well as whey acidic protein and lipid levels. In addition, 10μM THC, 10μM CBD, and the combination of 10μM THC + 10μM CBD significantly induced the expression of ER stress genes in HC11 cells. Furthermore, in the milk of women who used cannabis during pregnancy and lactation, the levels of secretory immunoglobulin A (SIgA) were decreased, relative to non-users. Altogether, our findings indicate that cannabis use in the perinatal period may have implications on breast milk composition and infant health. / Thesis / Doctor of Philosophy (Medical Science) / Breast milk is crucial to the nutrition and immunity of the newborn. It is produced by the mammary gland (MG), which is composed of mammary epithelial cells (MEC) that play a key role in producing and secreting proteins and factors into the milk. During pregnancy, the MG undergoes remodeling which is accompanied by differentiation of the MECs (change from unspecialized to a specialized stage that allows the MECs to produce milk proteins and other factors). The disruption in MEC differentiation can result in altered milk production and composition. Cannabis is used by women during pregnancy and breastfeeding. In this study, we investigated the impact of cannabinoids on the MEC differentiation and examined the effect of cannabis use in the perinatal period on the breast milk composition in humans. We reported that cannabinoids reduced the differentiation of MECs and maternal cannabis use during breastfeeding reduced levels of an essential immune factor.
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/28451 |
| Date | January 2023 |
| Creators | Josan, Chitmandeep |
| Contributors | Raha, Sandeep, Medical Sciences |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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