zithromax and Reperfusion-Injury

Retinal ischemic phenomena occur in several ocular diseases that share the degeneration and death of retinal ganglion cells (RGCs) as the final event. We tested the neuroprotective effect of azithromycin, a widely used semisynthetic macrolide antibiotic endowed with anti-inflammatory and immunomodulatory properties, in a model of retinal ischemic injury induced by transient elevation of intraocular pressure in the rat.. Retinal ischemia was induced in adult rats with transient elevation of intraocular pressure. RGCs were retrogradely labeled with Fluoro-Gold, and survival was assessed following a single dose of azithromycin given systemically at the end of the ischemia. The expression of death-associated proteins and extracellular signal-regulated kinase (ERK) activation was studied with western blotting. Expression and activity of matrix metalloproteinase-2 (MMP-2) and -9 were analyzed with gelatin zymography.. Acute post-injury administration of azithromycin significantly prevented RGC death. This effect was accompanied by reduced calpain activity and prevention of Bcl-2-associated death promoter (Bad) upregulation. The observed neuroprotection was associated with a significant inhibition of MMP-2/-9 gelatinolytic activity and ERK1/2 phosphorylation.. Azithromycin provides neuroprotection by modifying the inflammatory state of the retina following ischemia/reperfusion injury suggesting potential for repurposing as a drug capable of limiting or preventing retinal neuronal damage.

Topics: Animals; Anti-Bacterial Agents; Apoptosis; Azithromycin; bcl-Associated Death Protein; Blotting, Western; Calpain; Cell Survival; Cytoprotection; Disease Models, Animal; Extracellular Signal-Regulated MAP Kinases; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Neuroprotective Agents; Phosphorylation; Rats; Rats, Wistar; Reperfusion Injury; Retinal Diseases; Retinal Ganglion Cells

Clinical studies revealed that azithromycin reduces airway neutrophilia during chronic rejection after lung transplantation. Our aim was to investigate the possible effect of azithromycin on ischaemia-reperfusion injury. Azithromycin or water was administered to mice every other day during 2 weeks (n = 6/group). On the 14th day, the left lung was clamped to induce ischaemia (90 min). In two additional groups, animals underwent the same protocol, followed by 4 h of reperfusion. Two control groups were included with thoracotomy only. Inflammatory parameters and oxidative stress were measured in broncho-alveolar lavage of the left lung. Leukocytes, lymphocytes, neutrophils, 8-isoprostane and IL-1beta levels after ischaemia and reperfusion were significantly reduced in mice treated with azithromycin. There was a trend towards lower IL-6 and KC levels. A significant correlation was seen between 8-isoprostanes and neutrophils (Pearson r = 0.72; P = 0.0086), IL-6 (Pearson r = 0.84; P = 0.0006), KC (Pearson r = 0.88; P = 0.0002) and IL-1beta (Pearson r = 0.62; P = 0.0326). We conclude (i) that azithromycin reduces inflammation and oxidative stress in our IRI model, and (ii) that oxidative stress is correlated with the number of neutrophils and IL-6, KC and IL-1beta levels after ischaemia and reperfusion. Azithromycin should be further investigated as a novel drug to prevent lung ischaemia-reperfusion injury.

Topics: Animals; Azithromycin; Bronchoalveolar Lavage Fluid; Chemokines; Cytokines; Dinoprost; Female; Inflammation; Interleukin-1beta; Interleukin-6; Leukocyte Count; Lung; Mice; Neutrophils; Oxidative Stress; Reperfusion Injury