Inhibition of poly (adenosine diphosphate-ribose) polymerase attenuates lung-kidney crosstalk induced by intratracheal lipopolysaccharide instillation in rats
1 Departments of Critical Care Medicine, Tokyo Medical and Dental University Graduate School, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
2 Comprehensive Pathology, Tokyo Medical and Dental University Graduate School, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
3 Human Pathology, Tokyo Medical and Dental University Graduate School, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
4 Redox Response Cell Biology, Tokyo Medical and Dental University Medical Research Institute, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
5 Clinical Research Center, Tokyo Medical and Dental University Hospital of Medicine, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan
Respiratory Research 2013, 14:126 doi:10.1186/1465-9921-14-126Published: 15 November 2013
Acute respiratory distress syndrome (ARDS) is a severe form of lung injury that frequently occurs during pneumonia and sepsis. Lung inflammation in ARDS patients may have deleterious effects on remote organs such as the kidney. The nuclear enzyme poly(adenosine diphosphate-ribose) polymerase (PARP) enhances the nuclear factor (NF)-κB-dependent transcription of inflammatory cytokines. This study was conducted to elucidate two questions: first, whether the activation of PARP and NF-κB mediates the renal inflammation secondary to the lipopolysaccharide (LPS)-induced acute lung inflammation; second, whether a PARP inhibitor, 3-aminobenzamide (3-AB), attenuates lung and kidney inflammation by inhibiting NF-κB-dependent proinflammatory cytokines.
Male Sprague–Dawley rats were anesthetized, ventilated, and divided into three groups; a control group (n = 8); an LPS group (n = 12) intratracheally instilled with LPS (16 mg/kg), and an LPS + 3-AB group (n = 12) given the same dose of LPS by the same method followed by an intravenous injection of 3-AB (20 mg/kg). Hemodynamics, arterial blood gas, and the plasma levels of lactate, creatinine and potassium were measured at 0,1,2,3, and 4 h after treatment. The lung wet/dry ratio was measured at 4 h. The mRNA expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 in the lung and kidney were measured by TaqMan real-time PCR. PARP and NF-κB in the lung and kidney were histologically examined by immunostaining and assigned expression scores.
LPS induced metabolic acidosis, hypotension, hypoxemia, increased the lung wet/dry ratio, increased the plasma levels of creatinine and potassium, and increased the cytokine mRNA expressions in the lung and kidney. All of these effects were associated with strong expression of PARP and NF-κB. Treatment with 3-AB prevented the LPS-induced metabolic acidosis and hypotension, reduced the plasma levels of lactate, creatinine and potassium, reduced the cytokine mRNA expressions, reduced the expression of PARP and NF-κB, improved pulmonary edema and oxygenation and preserved renal function.
The PARP inhibition attenuated lung-kidney crosstalk induced by intratracheal LPS instillation, partly via an inhibition of NF-κB dependent proinflammatory cytokines.