Anti-Cysteine monoclonal antibody, clone 5C6

Precise detection of intracellular Cys will be helpful to accurately assess the physiological functions in the physiological and pathological processes. Herein, a new probe Meoeth-Cy-OBz-oCl capable of Cys sensing with high selectivity over other mercaptoamino-acid molecules including Hcy and GSH was developed. The studies on sensing mechanism supported thiols-induced SNAr substitution-rearrangement cascade reaction which allowed discriminating Cys from Hcy/GSH. And its preferential fluorescence response of Meoeth-Cy-OBz-oCl to intracellular Cys was also achieved by means of fluorescence imaging in HeLa cells. Besides, Meoeth-Cy-OBz-oCl was confirmed possessing mitochondria-targeting ability in living cells. In addition, fluorescence imaging in BALB/c mice revealed that Meoeth-Cy-OBz-oCl could visually monitor the variation of Cys in vivo.

Background and Aims Sterile inflammation is a major clinical concern during ischemia-reperfusion injury (IRI) triggered by traumatic events, including stroke, myocardial infarction, and solid organ transplantation. Despite high-mobility group box 1 (HMGB1) clearly being involved in sterile inflammation, its role is controversial because of a paucity of patient-focused research. Approach and Results Here, we examined the role of HMGB1 oxidation states in human IRI following liver transplantation. Portal blood immediately following allograft reperfusion (liver flush; LF) had increased total HMGB1, but only LF from patients with histopathological IRI had increased disulfide-HMGB1 and induced Toll-like receptor 4-dependent tumor necrosis factor alpha production by macrophages. Disulfide HMGB1 levels increased concomitantly with IRI severity. IRI+ prereperfusion biopsies contained macrophages with hyperacetylated, lysosomal disulfide-HMGB1 that increased postreperfusion at sites of injury, paralleling increased histone acetyltransferase general transcription factor IIIC subunit 4 and decreased histone deacetylase 5 expression. Purified disulfide-HMGB1 or IRI+ blood stimulated further production of disulfide-HMGB1 and increased proinflammatory molecule and cytokine expression in macrophages through a positive feedback loop. Conclusions These data identify disulfide-HMGB1 as a mechanistic biomarker of, and therapeutic target for, minimizing sterile inflammation during human liver IRI.