A novel recombinant snake venom metalloproteinase from Agkistrodon acutus protects against taurocholate-induced severe acute pancreatitis in rats

Experimental Acute Pancreatitis Models: History, Current Status, and Role in Translational Research

Acute pancreatitis is a potentially severe inflammatory disease that may be associated with a substantial morbidity and mortality. Currently there is no specific treatment for the disease, which indicates an ongoing demand for research into its pathogenesis and development of new therapeutic strategies. Due to the unpredictable course of acute pancreatitis and relatively concealed anatomical site in the retro-peritoneum, research on the human pancreas remains challenging. As a result, for over the last 100 years studies on the pathogenesis of this disease have heavily relied on animal models. This review aims to summarize different animal models of acute pancreatitis from the past to present and discuss their main characteristics and applications. It identifies key studies that have enhanced our current understanding of the pathogenesis of acute pancreatitis and highlights the instrumental role of animal models in translational research for developing novel therapies.

Functional recombinant single-chain variable fragment antibody against Agkistrodon acutus venom

Agkistrodon acutus bites are conventionally treated with animal-derived antivenom, the use of which is limited due to allergic reactions and serum sickness. Thus in the present study, the genes of humanized antibodies produced in response to A. acutus venom were extracted from lymphocytes from patients bitten by A. acutus. A single-chain variable fragment (scFv) library against venom was constructed using a T7 phage display system. ScFv genes that exhibited high affinity to venom were selected by library biopanning. An expression system was constructed for antivenom scFv fused with 6×His tag at its N- and C-terminus using pET-28a (+) vector. The scFv proteins could achieve functional and soluble expression in Escherichia coli via the auto-induction method. The purity and activity of the scFv genes and proteins were confirmed by SDS-PAGE, western blotting and ELISA. The results indicated that three soluble scFv proteins exhibited specific affinity to A. acutus venom and were harvested via the auto-induction method.

Interaction between TNF and BmooMP-Alpha-I, a Zinc Metalloprotease Derived from Bothrops moojeni Snake Venom, Promotes Direct Proteolysis of This Cytokine: Molecular Modeling and Docking at a Glance

Tumor necrosis factor (TNF) is a major cytokine in inflammatory processes and its deregulation plays a pivotal role in several diseases. Here, we report that a zinc metalloprotease extracted from Bothrops moojeni venom (BmooMP-alpha-I) inhibits TNF directly by promoting its degradation. This inhibition was demonstrated by both in vitro and in vivo assays, using known TLR ligands. These findings are supported by molecular docking results, which reveal interaction between BmooMP-alpha-I and TNF. The major cluster of interaction between BmooMP-alpha-I and TNF was confirmed by the structural alignment presenting Ligand Root Mean Square Deviation LRMS = 1.05 Å and Interactive Root Mean Square Deviation IRMS = 1.01 Å, this result being compatible with an accurate complex. Additionally, we demonstrated that the effect of this metalloprotease on TNF is independent of cell cytotoxicity and it does not affect other TLR-triggered cytokines, such as IL-12. Together, these results indicate that this zinc metalloprotease is a potential tool to be further investigated for the treatment of inflammatory disorders involving TNF deregulation.

The regulatory role of immunosuppressants on immune abnormalities in acute pancreatitis

The uncontrolled progression of the inflammatory cascade is the main cause underlying the development of multiple organ dysfunction syndrome (MODS) in acute pancreatitis. In this study, we investigated the effects of several immunosuppressants on mitigating the systemic inflammatory reaction syndrome (SIRS) and the compensatory anti-inflammatory response syndrome (CARS) associated with acute pancreatitis. A total of 93 male Sprague Dawley rats were divided into 5 groups: group 1 was the sham group and group 2 underwent laparoscopic intrapancreatic duct injection of sodium taurocholate to induce pancreatitis. The remaining 3 groups were the same as group 2, with the addition of methylprednisolone, cyclophosphamide or methotrexate treatment (metastab, CTX or MTX groups, respectively). Following establishment of the acute pancreatitis model, the serum levels of inflammatory and anti-inflammatory cytokines in groups 2, 3, 4 and 5 were found to be significantly elevated. Following immunosuppressant administration, the levels of all inflammatory and anti-inflammatory cytokines investigated in groups 3, 4 and 5 were decreased compared to those in group 2. The pancreatic amylase levels and pancreatic wet weight (PWW) were also decreased in groups 3, 4 and 5 compared to those in group 2. Therefore, immunosuppressants may reduce inflammation-related cytokine levels in acute pancreatitis and relieve disease progression.