PS-B08-9: INHIBITION OF PERIOSTIN PROTECTED FROM EXACERBATION OF INFLAMMATION IN RHABDOMYOLYSIS-INDUCED ACUTE KIDNEY INJURY

Abstract

Objective: Rhabdomyolysis is the breakdown of damaged skeletal muscle and the leakage of muscle-cell contents, including myoglobin, and other sarcoplasmic proteins into the circulation. These products may be filtered through the glomeruli, leading to acute kidney injury (AKI) via several mechanisms, such as inflammation and intratubular obstruction secondary to protein precipitation. New therapeutic strategy to lessen AKI are urgently needed. Thus far, several cellular pathways, nuclear factor kappa beta (NF-KB) as well as including pro-inflammatory effects on epithelial and tubular epithelial cells, have been identified as the major avenues for the initiation of the matrix-producing cells in AKI. Recently, it is suggested that periostin, extracellular matrix, is involved in the development of inflammation through the modulation of NF-KB pathway. However, periostin on the progression of the inflammation protection in AKI due to rhabdomyolysis is unclear. This study aimed to investigate the role of periostin in a rhabdomyolysis mice model of AKI. Design and method: In vivo, rhabdomyolysis-induced AKI was created by an intramuscular injection of 50% glycerol (5 mg/kg body weight). The expression level of periostin during the progression of acute renal failure after glycerol intramuscular injection for C57BL/6J wild type (WT) mice model was investigated. The mice were sacrificed at 72 hours after glycerol injection. We have developed periostin null mice to examine the role of periostin on acute renal failure. The role of periostin were further investigated through in vitro methods. In vitro, the development of renal inflammation is associated with NF-KB pathway. To investigate the function of periostin, we administrated Hemin(100uM) on NIH-3T3 fibroblast cells and the subsequent signaling pathways was examined. Results: The expression of periostin was highly increased, peaking at approximately 72 hours after gycerol injection. Inflammation-associated mRNA such as Monocyte Chemotactic Protein-1, tumor necrosis factor-alpha and IL6 expression and tubular injury score in H-E staining was more reduced in periostin null mice than WT mice at 72 hours after gycerol injection. Finally, an intraperitoneal injection of periostin antibody suppressed the mortality. These findings suggest a causal link between periostin and inflammation in AKI induced by rhabdomyolysis. In addition, an intraperitoneal injection of antibody for periostin antibody might be a new therapeutic strategy against the development of AKI induced by rhabdomyolysis. Conclusions: Periostin were highly expressed in kidney via rhabdomyolysis, and were a positive regulator of AKI. Targeting periostin might offer a new therapeutic strategy against the development of renal failure.