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Elhalem, E.

Publications and source records attributed to Elhalem, E..

2 recordsLinked to original sources
bioRxiv2026

Purified CBD and CBD-rich full-spectrum Cannabis sativa extract potentiate the angiogenic paracrine function of umbilical cord derived mesenchymal stem cells

BackgroundChronic and non-healing wounds remain a major clinical challenge with limited therapeutic options. Angiogenesis and inflammation are central to tissue repair, and mesenchymal stem cells (MSC) contribute to these processes through their trophic and immunomodulatory secretome. Cannabidiol (CBD) exhibits antioxidant and immunomodulatory properties. However, whether CBD-rich Cannabis sativa extract stimulate MSC toward a pro-angiogenic secretome remains unclear. PurposeThis study aims to determine whether purified CBD or a phytochemically CBD-rich full spectrum extract stimulate umbilical cord-derived human MSC (UC-hMSC) to secrete pro-angiogenic factors and enhance endothelial responses relevant to wound healing. MethodsUC-hMSC were preconditioned with either purified CBD or a CBD-rich full-spectrum extract. Transcriptional changes were assessed by qPCR. The functional impact of the resulting secretomes was evaluated in vitro using HUVEC-based proliferation and tube formation assays, and in vivo through the chick chorioallantoic membrane assay. To explore underlying mechanisms, we examined HIF-1 stabilization and VEGFA release in UC-hMSC, and VEGFR-2/ERK signaling in HUVEC. ResultsPurified CBD and full-spectrum CBD extract preconditioned UC-hMSC secretomes, increased HUVEC proliferation, tube formation, and enhanced vascular branching in the CAM assay. Mechanistic analyses indicated activation of the HIF-1/VEGF axis in UC-hMSC, and ERK1/2 activation in HUVEC that was sensitive to VEGFR-2 blockade. ConclusionPurified CBD and CBD-rich full-spectrum extract prime UC-hMSC toward a pro-angiogenic secretome that promotes endothelial activation and neovascularization. These findings suggest that cannabinoid-based preconditioning of UC-hMSC involves the HIF-1/VEGF axis and VEGFR-2/ERK signaling pathways in endothelial cells, supporting further investigation of this approach in wound healing and regenerative therapies.

cell biology↗
bioRxiv2026

RasGRP1 agonists stimulate P-TEFb biogenesis via MEK-ERK-mTORC1 signaling to reverse HIV latency with minimal CD4 downregulation

Reactivation of latent HIV to facilitate clearance of persisting infected cells requires identifying non-toxic latency-reversing agents (LRAs) that activate P-TEFb, a cellular transcription factor essential for efficient HIV RNA synthesis. Diacylglycerol (DAG)-mimicking PKC agonists induce P-TEFb to reverse HIV latency mainly through a PKC-independent RasGRP1-Ras-Raf-MEK-ERK1/2 pathway, but also elicit global T-cell activation and a drastic downregulation of CD4 receptors. Here, we demonstrate that synthetic DAG-indololactones, which preferentially bind RasGRP1 over PKC by up to 60-fold, strongly induce posttranscriptional P-TEFb expression in memory CD4+ T cells via MEK-ERK1/2-mTORC1 signaling without triggering T-cell activation markers and with minimal CD4 loss. Elevation of T-cell activation markers by natural and synthetic PKC agonists proceeds through MEK-ERK1/2 but is independent of mTORC1 activity. Combinations of the DAG-indololactone 2A127 and HDAC inhibitors synergistically reactivate latent HIV in a primary T-cell model and CD4+ T cells from treated individuals. These findings suggest that a combination LRA approach targeting P-TEFb production through RasGRP1-ERK1/2-mTORC1 signaling and the epigenetic activation of proviral HIV can efficiently and safely reverse HIV latency.

cell biology↗