3.4. ON cells from cannabis users show proteomic alterations
The label-free proteomic approach allowed the identification of 65 proteins that were differentially expressed between ON cells derived from control subjects and cannabis users (49 upregulated and 16 downregulated). By analysing the list of differentially expressed proteins with IPA, we obtained information about the alterations induced in canonical pathways, the molecular/cellular functions, the development of physiological systems, and related diseases and disorders (Figs. 3-4). Remarkably, differentially expressed proteins in cannabis users were related to several canonical pathways, including Integrin, Integrin-linked kinase (ILK), Focal Adhesion Kinase (FAK) and Actin Cytoskeleton signalling, as well as on cell behavior like Fc Receptor-mediated phagocytosis, microtubule dynamics and its influence on cell morphology, cell development, and at the level of tissue assembly and organization. In addition, the changes affected cell growth and proliferation, and inhibited cell death (Fig. 4B-C). These pathways and activities are of interest because they play an important role in nervous system development and function (Sacco et al., 2018). Indeed, 19 proteins involved in nervous system development and activity were differentially expressed in ON cells from cannabis users (Fig. 3B), alterations to which has also been described in mental disorders and brain (neurological) pathologies (Hakak et al., 2001; Bowden et al., 2008; Morin et al., 2009; Green et al., 2013; Volk and Lewis, 2016). Indeed, some of the differentially expressed proteins identified were related to disorders like schizophrenia, DiGeorge syndrome, epilepsy or bipolar disorder (Fig. 4D). Complete and detailed information regarding proteins changes can be found in the Supplementary Table 1.
Overall, according to IPA the proteins, altered in ON cells from cannabis consumers were apparently involved in pathways related to cell viability, morphology and more importantly, neuronal development and function.