Sunnybrook Research Institute, Toronto, ON, Canada.
Department of Surgery, Division of Plastic Surgery, University of Toronto, Toronto, ON, Canada.
FASEB J. 2021 May;35(5):e21596. doi: 10.1096/fj.202100388R.
Severe burns remain a leading cause of death and disability worldwide. Despite advances in patient care, the excessive and uncontrolled hypermetabolic stress response induced by this trauma inevitably affects every organ system causing substantial morbidity and mortality. Recent evidence suggests interleukin-6 (IL-6) is a major culprit underlying post-burn hypermetabolism. Indeed, genetic deletion of IL-6 alleviates various complications associated with poor clinical outcomes including the adverse remodeling of adipose tissue, cachexia and hepatic steatosis. Thus, pharmacological blockade of IL-6 may be a more favorable treatment option to fully restore metabolic function after injury. To test this, we investigated the safety and effectiveness of blocking IL-6 for post-burn hypermetabolism using a validated anti-IL-6 monoclonal antibody (mAb) in our experimental murine model. Here, we show daily anti-IL-6 mAb administration protects against burn-induced weight loss (P < .0001) without any adverse effect on mortality. At the organ level, post-burn treatment with the IL-6 blocker suppressed the thermogenic activation of adipose tissue (P < .01) and its associated wasting (P < .05). The reduction of browning-induced lipolysis (P < .0001) indirectly decreased hepatic lipotoxicity (P < .01) which improved liver dysfunction (P < .05). Importantly, the beneficial effects of this anti-IL-6 agent extended to the skin, reflected by the decrease in excessive collagen deposition (P < .001) and genes involved in pathologic fibrosis and scarring (P < .05). Together, our results indicate that post-burn IL-6 blockade leads to significant improvements in systemic hypermetabolism by inhibiting pathological alterations in key immunometabolic organs. These findings support the therapeutic potential of anti-IL-6 interventions to improve care, quality of life, and survival in burned patients.
严重烧伤仍然是全球范围内导致死亡和残疾的主要原因。尽管在患者治疗方面取得了进展,但这种创伤引起的过度和不受控制的高代谢应激反应不可避免地影响每个器官系统,导致大量发病率和死亡率。最近的证据表明,白细胞介素-6(IL-6)是烧伤后高代谢的主要罪魁祸首。事实上,IL-6 的基因缺失减轻了与不良临床结局相关的各种并发症,包括脂肪组织的不良重塑、恶病质和肝脂肪变性。因此,抑制 IL-6 的药理阻断可能是一种更有利的治疗选择,可在损伤后完全恢复代谢功能。为了验证这一点,我们使用经过验证的抗 IL-6 单克隆抗体(mAb)在实验性小鼠模型中研究了阻断 IL-6 治疗烧伤后高代谢的安全性和有效性。在这里,我们表明,每天给予抗 IL-6 mAb 可防止烧伤引起的体重减轻(P<.0001),而不会对死亡率产生任何不利影响。在器官水平上,烧伤后用 IL-6 阻断剂治疗可抑制脂肪组织的热原激活(P<.01)及其相关的消耗(P<.05)。棕色诱导的脂肪分解减少(P<.0001)间接降低了肝毒性(P<.01),从而改善了肝功能障碍(P<.05)。重要的是,这种抗 IL-6 药物的有益作用扩展到皮肤,表现为过度胶原沉积减少(P<.001)和涉及病理性纤维化和瘢痕形成的基因减少(P<.05)。总之,我们的研究结果表明,烧伤后 IL-6 阻断通过抑制关键免疫代谢器官的病理性改变,导致全身高代谢显著改善。这些发现支持抗 IL-6 干预的治疗潜力,以改善烧伤患者的护理、生活质量和存活率。