jwh-133 and Subarachnoid-Hemorrhage

We evaluated whether JWH133, a selective cannabinoid type 2 receptor (CB2R) agonist, prevented neurogenic pulmonary edema (NPE) after subarachnoid hemorrhage (SAH) by attenuating inflammation. Adult male rats were assigned to six groups: sham-operated, SAH with vehicle, SAH with JWH133 (0.3, 1.0, or 3.0 mg/kg) treatment 1 h after surgery, and SAH with JWH133 (1.0 mg/kg) at 1 h with a selective CB2R antagonist, SR144528 (3.0 mg/kg). The perforation model of SAH was performed and pulmonary wet-to-dry weight ratio was evaluated 24 and 72 h after surgery. Western blot analyses and immunohistochemistry were evaluated 24 h after surgery. JWH133 (1.0 mg/kg) significantly and most strongly improved lung edema 24 h after SAH. SR144528 administration significantly reversed the effects of JWH133 (1.0 mg/kg). SAH-induced increasing levels of myeloperoxidase (MPO) and decreasing levels of a tight junction (TJ) protein, junctional adhesion molecule (JAM)-A, were ameliorated by JWH133 (1.0 mg/kg) administration 24 h after SAH. Immunohistochemical assessment also confirmed substantial leukocyte infiltration in the outside of vessels in SAH, which were attenuated by JWH133 (1.0 mg/kg) injection. CB2R agonist ameliorated lung permeability by inhibiting leukocyte trafficking and protecting tight junction proteins in the lung of NPE after SAH.

Topics: Animals; Blotting, Western; Camphanes; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Cannabinoids; Cell Movement; Disease Models, Animal; Immunohistochemistry; Junctional Adhesion Molecules; Lung; Male; Neutrophils; Organ Size; Peroxidase; Pulmonary Edema; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB2; Subarachnoid Hemorrhage

Early brain injury (EBI), following subarachnoid hemorrhage (SAH), comprises blood-brain barrier (BBB) disruption and consequent edema formation. Peripheral leukocytes can infiltrate the injured brain, thereby aggravating BBB leakage and neuroinflammation. Thus, anti-inflammatory pharmacotherapies may ameliorate EBI and provide neuroprotection after SAH. Cannabinoid type 2 receptor (CB2R) agonism has been shown to reduce neuroinflammation; however, the precise protective mechanisms remain to be elucidated. This study aimed to evaluate whether the selective CB2R agonist, JWH133 can ameliorate EBI by reducing brain-infiltrated leukocytes after SAH. Adult male Sprague-Dawley rats were randomly assigned to the following groups: sham-operated, SAH with vehicle, SAH with JWH133 (1.0mg/kg), or SAH with a co-administration of JWH133 and selective CB2R antagonist SR144528 (3.0mg/kg). SAH was induced by endovascular perforation, and JWH133 was administered 1h after surgery. Neurological deficits, brain water content, Evans blue dye extravasation, and Western blot assays were evaluated at 24h after surgery. JWH133 improved neurological scores and reduced brain water content; however, SR144528 reversed these treatment effects. JWH133 reduced Evans blue dye extravasation after SAH. Furthermore, JWH133 treatment significantly increased TGF-β1 expression and prevented an SAH-induced increase in E-selectin and myeloperoxidase. Lastly, SAH resulted in a decreased expression of the tight junction protein zonula occludens-1 (ZO-1); however, JWH133 treatment increased the ZO-1 expression. We suggest that CB2R stimulation attenuates neurological outcome and brain edema, by suppressing leukocyte infiltration into the brain through TGF-β1 up-regulation and E-selectin reduction, resulting in protection of the BBB after SAH.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Brain; Brain Edema; Camphanes; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Cannabinoids; Chemotaxis, Leukocyte; E-Selectin; Gene Expression Regulation; Leukocytes; Male; Peroxidase; Pyrazoles; Rats; Receptor, Cannabinoid, CB2; Subarachnoid Hemorrhage; Transforming Growth Factor beta1; Zonula Occludens-1 Protein

Early brain injury (EBI) which comprises of vasogenic edema and apoptotic cell death is an important component of subarachnoid hemorrhage (SAH) pathophysiology. This study evaluated whether cannabinoid receptor type 2 (CB2R) agonist, JWH133, attenuates EBI after SAH and whether CB2R stimulation reduces pro-apoptotic caspase-3 via up-regulation of cAMP response element-binding protein (CREB)-Bcl-2 signaling pathway. Male Sprague-Dawley rats (n=123) were subjected to SAH by endovascular perforation. Rats received vehicle or JWH133 at 1h after SAH. Neurological deficits and brain water content were evaluated at 24h after SAH. Western blot was performed to quantify phosphorylated CREB (pCREB), Bcl-2, and cleaved caspase-3 levels. Neuronal cell death was evaluated with terminal deoxynucleotidyl transferase-mediated uridine 5'-triphosphate-biotin nick end-labeling staining. Additionally, CREB siRNA was administered to manipulate the proposed pathway. JWH133 (1.0mg/kg) improved neurological deficits and reduced brain water content in left hemisphere 24h after SAH. JWH133 significantly increased activated CREB (pCREB) and Bcl-2 levels and significantly decreased cleaved caspase-3 levels in left hemisphere 24h after SAH. CREB siRNA reversed the effects of treatment. TUNEL positive neurons in the cortex were reduced with JWH133 treatment. Thus, CB2R stimulation attenuated EBI after SAH possibly through activation of pCREB-Bcl-2 pathway.

Topics: Animals; Apoptosis; Brain Injuries; Cannabinoids; Caspase 3; CREB-Binding Protein; Disease Models, Animal; Enzyme Inhibitors; Male; Phosphorylation; Proto-Oncogene Proteins c-bcl-2; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB2; Signal Transduction; Subarachnoid Hemorrhage; Time Factors