Alpha B-crystallin Ameliorates Imbalance of Redox Homeostasis, Inflammation and Apoptosis in an Acute Lung Injury Model with Rats.

Objective: Ischemia-reperfusion (IR) of the aorta is a significant contributor to the development of postoperative acute lung damage after abdominal aortic surgery. The aim of the present study was to examine the effect of alpha B-crystallin, a small heat shock protein (known as HspB5), on lung injury induced by abdominal aortic IR in rats.

Methods: Male Sprague-Dawley rats were divided into three groups: control, ischemia-reperfusion (IR, 90 min ischemia and 180 min reperfusion), and alpha B-crystallin +IR. Alpha B-crystallin (50 μg/100 g) was intraperitoneally administered 1 h before IR. Lung tissue samples were obtained for histological and biochemical analyses of oxidative stress and cytokine and apoptosis parameters in plasma, lung tissues, and bronchoalveolar lavage (BAL) fluid.

Results: The levels of malondialdehyde, reactive oxygen species, total oxidant status, tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), nuclear factor kappa B (NFKβ), caspase-9 (CASP-9), 8-hydroxy-2'-deoxyguanosine, total antioxidant status, superoxide dismutase, and interleukin-10 levels in lung tissues, plasma, and BAL fluid (p<0.05 versus control) increased in Aortic IR. However, alpha B-crystallin significantly reduced the lung tissue levels of oxidative, inflamatuvar, and apoptotic parameters in the plasma, lung tissues, and BAL fluid (p<0.05 versus aortic IR). Histopathological results showed that alpha B-crystallin ameliorated the morphological changes related to lung injury (p<0.001).

Conclusion: Alpha B-crystallin substantially restored disrupted the redox balance, inflammation, and apoptotic parameters in rats exposed to IR. The cytoprotective effect of alpha B-crystallin on redox balance might be attributed to improved lung injury.