Kallistatin treatment attenuates lethality and organ injury in mouse models of established sepsis

Abstract

IntroductionKallistatin levels in the circulation are reduced in patients with sepsis and liver disease. Transgenic mice expressing kallistatin are resistant to lipopolysaccharide (LPS)-induced mortality. Here, we investigated the effect of kallistatin on survival and organ damage in mouse models of established sepsis.MethodsMice were rendered septic by cecal ligation and puncture (CLP), or endotoxemic by LPS injection. Recombinant human kallistatin was administered intravenously six hours after CLP, or intraperitoneally four hours after LPS challenge. The effect of kallistatin treatment on organ damage was examined one day after sepsis initiation, and mouse survival was monitored for four to six days.ResultsHuman kallistatin was detected in mouse serum of kallistatin-treated mice. Kallistatin significantly reduced CLP-induced renal injury as well as blood urea nitrogen, serum creatinine, interleukin-6 (IL-6), and high mobility group box-1 (HMGB1) levels. In the lung, kallistatin decreased malondialdehyde levels and HMGB1 and toll-like receptor-4 (TLR4) synthesis, but increased suppressor of cytokine signaling-3 (SOCS3) expression. Moreover, kallistatin attenuated liver injury, serum alanine transaminase (ALT) levels and hepatic tumor necrosis factor-α (TNF-α) synthesis. Furthermore, delayed kallistatin administration improved survival in CLP mice by 38%, and LPS-treated mice by 42%. In LPS-induced endotoxemic mice, kallistatin attenuated kidney damage in association with reduced serum creatinine, IL-6 and HMGB1 levels, and increased renal SOCS3 expression. Kallistatin also decreased liver injury in conjunction with diminished serum ALT levels and hepatic TNF-α and TLR4 expression. In cultured macrophages, kallistatin through its active site increased SOCS3 expression, but this effect was blocked by inhibitors of tyrosine kinase, protein kinase C and extracellular signal-regulated kinase (ERK), indicating that kallistatin stimulates a tyrosine-kinase-protein kinase C-ERK signaling pathway.ConclusionsThis is the first study to demonstrate that delayed human kallistatin administration is effective in attenuating multi-organ injury, inflammation and mortality in mouse models of polymicrobial infection and endotoxemia. Thus, kallistatin therapy may provide a promising approach for the treatment of sepsis in humans.

Kallistatin in Sepsis: Protective Actions and Potential Therapeutic Applications

“…NO, in turn, blocks TNF-α-induced ROS formation by inhibiting NADPH oxidase activity and NF-κB activation [58,59]. Kallistatin via its active site induces the expression of SOCS3, a negative regulator of inlammation [48], thereby inhibiting LPS-induced TNF-α production in cultured macrophages [48,60]. Moreover, kallistatin via its heparin-binding site antagonizes TNF-α-induced oxidative stress, NF-κB activation and inlammatory gene expression in vitro [20].…”

“…Kallistatin's active site is crucial for: (1) complex formation with tissue kallikrein and inhibiting tissue kallikrein activity and bioavailability [13,27]; (2) increasing eNOS and SIRT1 expression and activation, leading to elevated NO formation [28]; (3) stimulating SOCS3 expression [48]; and (4) interacting with a tyrosine kinase [28,48]. Kallistatin via its heparin-binding domain interacts with cell surface heparan sulfate proteoglycans, thereby antagonizing the following biological efects: (1) VEGF-mediated angiogenesis and vascular permeability [16,20]; (2) TNF-α-induced NF-κB activation, inlammation, oxidative stress, and apoptosis [20]; (3) HMGB1-induced inlammatory gene expression and oxidative stress [29]; (4) TGF-β-induced endothelial-mesenchymal transition (EndMT), and epithelialmesenchymal transition (EMT) [28]; (5) Wnt-mediated cancer cell proliferation, migration, invasion, and autophagy [42,44]; and (6) EGF-induced cancer cell migration and invasion (unpublished results).…”

“…A human kallistatin gene polymorphism is correlated with a decreased risk of developing acute kidney injury in patients with septic shock [64]. Kallistatin treatment exerts beneicial efects in Gram-negative and Gram-positive bacteremia, as well as "mixed" polymicrobial infection [29,35,48,65]. Transgenic mice expressing kallistatin are highly resistant to mortality induced by LPS [66].…”

“…NO inhibits oxidative organ damage by inactivating NAD(P)H oxidase activity [59]. Furthermore, delayed kallistatin administration after the onset of sepsis atenuates mortality, kidney and liver injury in mouse models of polymicrobial sepsis and endotoxemia [48]. Kallistatin treatment inhibits systemic inlammation by reducing circulatory levels of TNF-α and HMGB1, and dramatically upregulating SOCS3 expression in the kidney and lung [48].…”

“…Furthermore, delayed kallistatin administration after the onset of sepsis atenuates mortality, kidney and liver injury in mouse models of polymicrobial sepsis and endotoxemia [48]. Kallistatin treatment inhibits systemic inlammation by reducing circulatory levels of TNF-α and HMGB1, and dramatically upregulating SOCS3 expression in the kidney and lung [48]. Kallistatin delivery improves mortality, atenuates acute lung damage in LPS-induced septic mice, and inhibits ROS-mediated inlammation and apoptosis in cultured lung epithelial cells [35].…”