Cannabidiol treatment of proliferating 3T3-L1 pre-adipocytes affects mature cell size and expression of acyltransferases involved in lipid droplet synthesis

Abstract

Abstract Background The phytocannabinoid cannabidiol (CBD) has been demonstrated to possess anti-inflammatory, anti-seizure, anti-oxidant, and proposed anti-obesity effects. Therapeutic modalities that improve the size of existing adipocytes through a reduction in hypertrophy, or result in increased hyperplasia (increased cell number) and decreased hypertrophy (enlarged cell size) during adipogenesis can result in smaller adipocytes that maintain insulin sensitivity, reducing the incidence of dysfunctional adipose tissue. The effect of timing CBD treatment to the proliferation (mitotic expansion) phase or the differentiation phase of pre-adipocytes on hyperplasia, hypertrophy, and expression of genes involved in triacylglycerol synthesis has not been investigated. We aimed to determine how exposing 3T3-L1 pre-adipocytes to CBD during the expansion or differentiation phase affected proliferation, cell size, and expression of enzymes involved in triacylglycerol synthesis.Methods Cells were treated with CBD at doses of 0.2 µM (low [CBD]) or 20 µM (high [CBD]) for measurement of cell viability and proliferation. Additionally, pre-adipocytes were exposed to CBD during proliferation and before stimulation of differentiation (expansion phase) or during the differentiation protocol (differentiation phase) and cell size, total lipid deposition and gene expression of acylglycerophosphate acyltransferase-2 (AGPAT2), diacylglycerol acyltransferase-2 (DGAT2), and glycerol-3-phosphate acyltransferase-3 (GPAT3) were quantified in the mature, lipid-storing adipocytes.Results The high CBD dose reduced cell viability and completely inhibited differentiation of pre-adipocytes into mature adipocytes when cells were treated during the differentiation period. Treatment of cells with the high CBD dose during the mitotic clonal expansion period significantly reduced but did not inhibit differentiation of the cells into the mature phenotype. The low CBD dose did not affect cell viability and resulted in increased proliferation and smaller mature adipocytes that did not differ from control cells with regards to lipid droplet deposition but that exhibited changes in gene expression of AGPAT and GPAT.Conclusions Our results suggest that a low (0.2 µM), physiologically achievable dose of CBD affects mature adipocyte cell size and gene expression of acyltransferases involved in triacylglycerol synthesis and that these effects are dependent on timing the CBD exposure to the cell’s mitotic clonal expansion phase.