Celastrol mitigates inflammation in sepsis by inhibiting the PKM2-dependent Warburg effect

Background: Sepsis involves life-threatening organ dysfunction and is caused by a dysregulated host response to infection. No specific therapies against sepsis have been reported. Celastrol(Cel) is a natural anti-inflammatory compound that shows potential against systemic inflammatory diseases. This study aimed to investigate the pharmacological activity and molecular mechanism of Cel in models of endotoxemia and sepsis.Methods: We evaluated the anti-inflammatory efficacy of Cel against endotoxemia and sepsis in mice and macrophage cultures treated with lipopolysaccharide(LPS). We screened for potential protein targets of Cel using activity-based protein profiling(ABPP). Potential targets were validated using biophysical methods such as cellular thermal shift assays(CETSA) and surface plasmon resonance(SPR). Residues involved in Cel binding to target proteins were identified through point mutagenesis, and the functional effects of such binding were explored through gene knockdown.Results: Cel protected mice from lethal endotoxemia and improved their survival with sepsis, and it significantly decreased the levels of pro-inflammatory cytokines in mice and macrophages treated with LPS(P <0.05). Cel bound to Cys424 of pyruvate kinase M2(PKM2), inhibiting the enzyme and thereby suppressing aerobic glycolysis(Warburg effect). Cel also bound to Cys106 in high mobility group box 1(HMGB1) protein, reducing the secretion of inflammatory cytokine interleukin(IL)-1β. Cel bound to the Cys residues in lactate dehydrogenase A(LDHA).Conclusions: Cel inhibits inflammation and the Warburg effect in sepsis via targeting PKM2 and HMGB1 protein.

Identification of antimalarial targets of chloroquine by a combined deconvolution strategy of ABPP and MS-CETSA

Background: Malaria is a devastating infectious disease that disproportionally threatens hundreds of millions of people in developing countries. In the history of anti-malaria campaign, chloroquine(CQ) has played an indispensable role, however, its mechanism of action(MoA) is not fully understood.Methods: We used the principle of photo-affinity labeling and click chemistry-based functionalization in the design of a CQ probe and developed a combined deconvolution strategy of activity-based protein profiling(ABPP) and mass spectrometry-coupled cellular thermal shift assay(MS-CETSA) that identified the protein targets of CQ in an unbiased manner in this study. The interactions between CQ and these identified potential protein hits were confirmed by biophysical and enzymatic assays.Results: We developed a novel clickable, photo-affinity chloroquine analog probe(CQP) which retains the antimalarial activity in the nanomole range, and identified a total of 40 proteins that specifically interacted and photocrosslinked with CQP which was inhibited in the presence of excess CQ. Using MS-CETSA, we identified 83 candidate interacting proteins out of a total of 3375 measured parasite proteins. At the same time, we identified 8 proteins as the most potential hits which were commonly identified by both methods.Conclusions: We found that CQ could disrupt glycolysis and energy metabolism of malarial parasites through direct binding with some of the key enzymes, a new mechanism that is different from its well-known inhibitory effect of hemozoin formation. This is the first report of identifying CQ antimalarial targets by a parallel usage of labeled(ABPP)and label-free(MS-CETSA) methods.

改良湿润密闭烧伤疗法治疗因飞溅钢水引起的面颈部烧伤

We present the case of a 35-year-old male foundry worker with painful burns after exposure to splashing 1500°C molten steel. This rare case involves a localized occupational-related molten steel burn on the cervicofacial region. The lesion was induced by hyperthermal contact of the skin with molten steel. This case report highlights a modified moist occluded burn therapy that is applied using a combination of modified chitin wound rehabilitating biogel (AmPoSa (?)) and sterile polyethylene film. The patient in our report achieved favourable aesthetic restoration without residual scars and hyperpigmented areas.

改良湿润封闭烧伤疗法:一种治疗热烧伤的新方法

Severe thermal burns usually result in complex facial problems such as contracture and formation of hyper/hypopigmentation,contracture,hypertrophic scars or deformity,with patients often requiring reconstructive surgery.Therefore,seeking a superior and reliable burn therapy remains a great challenge for plastic and burn surgeons.However,the optimal treatment of thermal injuries remains controversial.In the 1960s,a new therapeutic concept,that sterile polyethylene film might be used as a type of moist occlusive dressing,was successively proposed.Below we present a hypothesis that combined utilization of sterile polyethylene film and burn cream may be a novel and superior therapeutic approach for thermal burns.To distinguish this method from traditional moist burn therapy,this new therapy we proposed is named modified moist occlusive burn therapy(MMOBT).