The heme oxygenase-1 inducer attenuates organ injury in transient receptor potential melastatin 2 (Trpm2)-knockout (KO) mice after cecal ligation and puncture (CLP). The Trpm2-KO mice were injected with 10 mg/kg hemin or vehicle (intraperitoneal) every other day (three times) before CLP. CLP surgery was performed at 24 h after last hemin or vehicle injection. Mice were euthanized at 24 h after CLP. (A) Lungs and livers were harvested for hematoxylin and eosin staining (original magnifications, ×400). (B) The lung injury score (n = 6 per group), leukocytes infiltration (n = 6 per group), lung wet/dry weight ratio (n = 4 per group), and total protein concentration in bronchoalveolar lavage (BAL) (n = 4 per group) represent the severity of lung injury. (C) The liver injury score (n = 6 per group) and serum alanine aminotransferase (ALT) concentration represent the severity of liver injury (n = 4 per group). (D) Serum was harvested for detecting interleukin (IL)-6 and high mobility group protein B1 (HMGB1) levels by enzyme-linked immunosorbent assay (n = 6 per group). *P < 0.05; **P < 0.01, Student t test. Error bars denote the mean ± SEM.