作者: Svensson, Mattias ; Novello, Monica ; Bergonzini, Anna ; Norrby-Teglund, Anna ; Kaland, Lara ; Nilsson, Sara ; Engstrand, Olivia ; Tanaka, Emi ; Seidner, Lisa ; Palma Medina, Laura M.

Thrombomodulin (TM) is a membrane protein with significant roles in coagulation hemostasis and immune response. Its soluble form (sTM) has recently emerged as a key biomarker for severe invasive bacterial infections, including Necrotizing Soft Tissue Infections (NSTI). While various mechanical, chemical, and enzymatic mechanisms have been linked to TM shedding, this study investigates the direct impact of bacterial stimuli on soft tissue cells as primary sources of TM release. We stimulated organotypic models, composed of fibroblast and endothelial cells, with NSTI clinical isolates and found that while Group A Streptococcus and Escherichia coli had minimal effect on TM release, Staphylococcus aureus infection triggered a significant increase of sTM levels. We further assessed whether the secreted proteins of S. aureus led to higher TM levels by increased expression, increased cell toxicity, or direct cleavage of TM from the endothelial cell membrane. To investigate these mechanisms, we performed in vitro stimulations of endothelial monolayers with secreted proteins of two S. aureus isolates differing in their agr-system functionality. Our results indicate that S. aureus agr-regulated proteins induce TM shedding by direct cleavage from the cell membrane, an effect that was inhibited by metalloproteinase inhibitors. Stimulation with the pore-forming protein α-toxin showed similar results, suggesting a potential involvement of ADAM10 in TM cleavage. Additionally, we observed that other agr-regulated proteins can cleave TM directly. Altogether, this study reveals a pathogen-specific mechanism for TM release during S. aureus invasive infection, contributing to its elevated plasma levels and providing deeper insights into the pathophysiology of NSTI.

2026-02-01·ARCHIVES OF TOXICOLOGY

Targeting marine jellyfish toxins: development of metalloproteinase inhibitors through a specific method for protease substrate identification

Article

作者: Wang, Zhanhua ; Yu, Huahua ; Xing, Ronge ; Yu, Chunlin ; Li, Pengcheng ; Li, Rongfeng ; Wang, Wenjie ; Liu, Song

The venom of hazardous jellyfish contains harmful substances to human health, such as metalloproteinases, which are challenging to purify. Therefore, identifying substrate sequences using crude venom is crucial for the development of peptide inhibitors. This study utilized a designed peptide library and an abundance-based hydrolysis product analysis approach to identify the substrate sequences of toxin metalloproteinases from Nemopilema nomurai nematocyst venom (NnNV) and further modified these sequences into peptide inhibitors. Specifically, a peptide library comprising 41 potential substrate sequences was constructed and incubated with NnNV. 12 substrate sequences and 14 cleavage sites were identified from the hydrolysis products. In the design of peptide inhibitors, thiol (-SH) and phosphate groups (-PO₃H₂) were used as zinc-binding groups, and sixty derived peptides were obtained. 15 peptide inhibitors were selected for their efficacy in inhibiting toxin metalloproteinase activity, with CPRGQPIIQDV demonstrating the most potent effect. CPRGQPIIQDV mainly presented β-sheet and random coil structures, and significantly reduced the cytotoxicity and pro-inflammatory effects of NnNV on RAW264.7 cells. This study established a method for identifying metalloproteinase substrate sequences using crude jellyfish venom and provided an initial design and screening of peptide inhibitors, offering new insights into the management of jellyfish stings.

2025-08-01·BIOCHIMIE

Biochemical and proteomic profiling reveals potent proteolytic activity in the venom of Erythrolamprus melanotus (Shaw's dark ground snake, Xenodontini)

Article

作者: Zambrano, Duván F ; Junqueira-de-Azevedo, Inácio L M ; Bayona-Serrano, Juan D ; Bernal-Bautista, Manuel H ; Torres-Bonilla, Kristian A ; Sáenz-Suarez, Paula A ; Hyslop, Stephen

We describe here the Duvernoy's venom gland organization and biochemical and proteomic analyses of venom from the Colombian colubrid snake Erythrolamprus melanotus. Histological analysis indicated a serous venom gland distinct from the mucous supralabial gland. SDS-PAGE of the venom revealed >15 bands (∼15 kDa-∼200 kDa) and gelatin zymography revealed potent proteolytic activity; zymographic activity towards casein was considerably less. RP-HPLC yielded 16 peaks, several of which contained proteases, as assessed by gelatin zymography. Enzymatic assays using azocasein, azocoll and hide powder azure confirmed the proteolytic activity. The venom selectively degraded the Aα-chain of fibrinogen without affecting the Bβ and γ-chains (assessed by SDS-PAGE). All proteolytic activity was inhibited by EDTA (metalloproteinase inhibitor) but not by AEBSF (serine proteinase inhibitor). The venom had no l-amino acid oxidase, esterase, and PLA₂ activities. Proteomic analysis indicated the presence primarily of snake venom metalloproteinases (SVMP), snake venom matrix metalloproteinases (svMMP) and cysteine-rich secretory proteins (CRiSP). SVMP and svMMP were the major components, indicating that this venom is rich in proteases, in agreement with the findings for zymography and enzymatic assays. This study provides the first characterization of Colombian E. melanotus venom and highlights its rich content of metalloproteinases and potent proteolytic activity.

100 项与 01-07A 相关的药物交易

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