Aims: The aim of this study was to assess the effect of select cannabinoids on human immunodeficiency virus type 1 (HIV-1) transactivating (Tat) protein-enhanced monocyte-like cell adhesion to proteins of the extracellular matrix (ECM).
Main methods: Collagen IV, laminin, or an ECM gel was used to construct extracellular matrix layers. Human U937 monocyte-like cells were exposed to Tat in the presence of ∆(9)-tetrahydrocannabinol (THC), CP55,940, and other select cannabinoids. Cell attachment to ECM proteins was assessed using an adhesion assay.
Key findings: THC and CP55,940 inhibited Tat-enhanced attachment of U937 cells to ECM proteins in a mode that was linked to the cannabinoid receptor type 2 (CB2R). The cannabinoid treatment of Tat-activated U937 cells was associated with altered β1-integrin expression and distribution of polymerized actin, suggesting a modality by which these cannabinoids inhibited adhesion to the ECM.
Significance: The blood-brain barrier (BBB) is a complex structure that is composed of cellular elements and an extracellular matrix (ECM). HIV-1 Tat promotes transmigration of monocytes across this barrier, a process that includes interaction with ECM proteins. The results indicate that cannabinoids that activate the CB2R inhibit the ECM adhesion process. Thus, this receptor has potential to serve as a therapeutic agent for ablating neuroinflammation associated with HIV-elicited influx of monocytes across the BBB.
Keywords: 2-Arachidonoylglycerol (PubChem CID: 5282280); Arachidonyl-2-chloroethylamide (PubChem CID: 5311006); CP55,940 (PubChem CID: 104895); Cannabinoid; Cell adhesion; Extracellular matrix; HIV; Monocyte-like cells; SR141716A (PubChem CID: 104850); SR144528 (PubChem CID: 3081355); Tat; U937 cells; abnormal cannabidiol (PubChem CID: 3060519); ∆(9)-tetrahydrocannabinol (PubChem CID: 16078).
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