“Radiation-induced pulmonary fibrosis (RIF) is a severe complication of thoracic radiotherapy that limits its dose, intensity, and duration. The contribution of the endocannabinoid signaling system in pulmonary fibrogenesis is not known. Using a well-established mouse model of RIF, we assessed the involvement of cannabinoid receptor-1 (CB1) in the onset and progression of pulmonary fibrosis.
Our results show that CB1 signaling plays a key pathological role in the development of radiation-induced pulmonary inflammation and fibrosis, and peripherally restricted CB1 antagonists may represent a novel therapeutic approach against this devastating complication of radiotherapy/irradiation.”
“We report for the first time the involvement of cannabinoid receptor 1 (CB1)-mediated signaling in the onset and progression of radiation-induced pulmonary fibrosis (RIF). We were able to delay the onset of RIF by genetic targeting of CB1 receptors as well as by its pharmacological inhibition. Thus, pharmacological targeting of CB1 receptors with peripherally restricted CB1 antagonists void of central nervous system complications may represent a novel strategy to prevent the development of RIF.
In summary, we provide the first evidence on the key pathological role of CB1 signaling in radiation-induced pulmonary fibrogenesis and show that peripherally restricted CB1 antagonists may represent a novel therapeutic approach against this devastating and untreatable complication of radiotherapy/irradiation. Our results also suggest that targeting CB1 may provide benefits in other lung diseases associated with inflammation and fibrosis.”
“The term ‘endocannabinoid’ – originally coined in the mid-1990s after the discovery of membrane receptors for the psychoactive principle in Cannabis, Delta9-tetrahydrocannabinol and their endogenous ligands – now indicates a whole signalling system that comprises cannabinoid receptors, endogenous ligands and enzymes for ligand biosynthesis and inactivation. This system seems to be involved in an ever-increasing number of pathological conditions. With novel products already being aimed at the pharmaceutical market little more than a decade since the discovery of cannabinoid receptors, the endocannabinoid system seems to hold even more promise for the future development of therapeutic drugs. We explore the conditions under which the potential of targeting the endocannabinoid system might be realized in the years to come.” http://www.ncbi.nlm.nih.gov/pubmed/15340387
“Cannabinoids modulate fibrogenesis in scleroderma.
Ajulemic acid (AjA) is a non-psychoactive synthetic analogue of tetrahydrocannabinol that can bind the peroxisome proliferator-activated receptor-γ (PPAR-γ). Recent evidence suggests a key role for PPAR-γ in fibrogenesis. To determine whether AjA can modulate fibrogenesis in murine models of scleroderma.”
AjA significantly prevented experimental bleomycin-induced dermal fibrosis and modestly reduced its progression when started 3 weeks into the disease. AjA strongly reduced collagen neosynthesis by scleroderma fibroblasts in vitro, an action which was reversed completely by co-treatment with a selective PPAR-γ antagonist.”
AjA prevents progression of fibrosis in vivo and inhibits fibrogenesis in vitro by stimulating PPAR-γ signalling. Since therapeutic doses of AjA are well tolerated in humans, it is suggested that AjA as an interesting molecule targeting fibrosis in patients with scleroderma.”