ag-490 and Subarachnoid-Hemorrhage

Neuroinflammation is an important mechanism underlying brain injury caused by subarachnoid hemorrhage (SAH). C-C chemokine receptor type 1 (CCR1)-mediated inflammation is involved in the pathology of many central nervous system diseases. Herein, we investigated whether inhibition of CCR1 alleviated neuroinflammation after experimental SAH and aimed to elucidate the mechanisms of its potential protective effects.. To analyze SAH transcriptome data R studio was used, and a mouse model of SAH was established using endovascular perforations. In this model, the selective CCR1 antagonist Met-RANTES (Met-R) and the CCR1 agonist recombinant CCL5 (rCCL5) were administered 1 h after SAH induction. To investigate the possible downstream mechanisms of CCR1, the JAK2 inhibitor AG490 and the JAK2 activator coumermycin A1 (C-A1) were administered 1 h after SAH induction. Furthermore, post-SAH evaluation, including SAH grading, neurological function tests, Western blot, the terminal deoxynucleotidyl transferase dUTP nick end labeling assay, and Fluoro-Jade B and fluorescent immunohistochemical staining were performed. Cerebrospinal fluid (CSF) samples were detected by ELISA.. CCL5 and CCR1 expression levels increased significantly following SAH. Met-R significantly improved neurological deficits in mice, decreased apoptosis and degeneration of ipsilateral cerebral cortex neurons, reduced infiltrating neutrophils, and promoted microglial activation after SAH induction. Furthermore, Met-R inhibited the expression of p-JAK2, p-STAT3, interleukin-1β, and tumor necrosis factor-α. However, the protective effects of Met-R were abolished by C-A1 treatment. Furthermore, rCCL5 injection aggravated neurological dysfunction and increased the expression of p-JAK2, p-STAT3, interleukin-1β, and tumor necrosis factor-α in SAH mice, all of which were reversed by the administration of AG490. Finally, the levels of CCL5 and CCR1 were elevate in the CSF of SAH patient and high level of CCL5 and CCR1 levels were associated with poor outcome.. The present results suggested that inhibition of CCR1 attenuates neuroinflammation after SAH via the JAK2/STAT3 signaling pathway, which may provide a new target for the treatment of SAH.

Topics: Animals; Apoptosis; Interleukin-1beta; Janus Kinase 2; Mice; Neuroinflammatory Diseases; Receptors, CCR1; Receptors, Chemokine; Signal Transduction; STAT3 Transcription Factor; Subarachnoid Hemorrhage; Tumor Necrosis Factor-alpha

The Janus kinase (JAK) proteins are key regulators for transducing signals from the cell surface to the nucleus in response to cytokines to orchestrate the appropriate cellular response. Previous studies have demonstrated that JAK1 is activated in the basilar artery after subarachnoid hemorrhage (SAH), however it has not been investigated whether, and to what degree, JAK2 is induced by SAH and also the role of JAK2 in the pathogenesis of cerebral vasospasm following SAH remains unknown. Experiment 1 aimed to investigate the time-course of the JAK2 activation in the basilar artery after SAH. In Experiment 2, we chose the maximum time point of JAK2 activation and assessed the effect of AG490 (a specific JAK2 inhibitor) on regulation of cerebral vasospasm and endothelial apoptosis. All SAH animals were subjected to injection of autologous blood into cisterna magna twice on day 0 and day 2. As a result, the elevated expression of activated JAK2 was detected in the basilar artery after SAH and peaked on day 3. After AG490 intracisternal administration, the vasospasm was markedly aggravated and the apoptosis index of endothelial cells was also significantly increased in the basilar arteries. Anti-apoptotic genes such as bcl-2 and bcl-xL were down-regulated after the injections of AG490. Our results suggest that JAK2 is activated in the arterial wall after SAH, playing a beneficial role to vasospasm development, possibly through protecting endothelial cells and up-regulating anti-apoptotic genes.

Topics: Analysis of Variance; Animals; bcl-X Protein; Blood Vessels; Disease Models, Animal; Enzyme Inhibitors; Gene Expression Regulation; In Situ Nick-End Labeling; Janus Kinase 2; Proto-Oncogene Proteins c-bcl-2; Rabbits; Subarachnoid Hemorrhage; Time Factors; Tyrphostins; Vasospasm, Intracranial