Zhx2 Accelerates Sepsis by Promoting Macrophage Glycolysis via Pfkfb3

Abstract

Sepsis is a life-threatening condition with limited therapeutic options, characterized as excessive systemic inflammation and multiple organ failure. Macrophages play critical roles in sepsis pathogenesis. Metabolism orchestrates homeostasis of macrophages. However, the precise mechanism of macrophage metabolism during sepsis remains poorly elucidated. In this study, we identified the key role of zinc fingers and homeoboxes (Zhx2), a ubiquitous transcription factor, in macrophage glycolysis and sepsis by enhancing 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (Pfkfb3) expression. Mice with myeloid Zhx2-specific deletion (abbreviated as MKO) showed more resistance to cecal ligation and puncture and LPS-induced sepsis, exhibiting as prolonged survival, attenuated pulmonary injury, and reduced level of proinflammatory cytokines, such as TNF-α, IL-6, and IL-1β. Interestingly, Zhx2 deletion conferred macrophage tolerance to LPS-induced glycolysis, accompanied by reduced proinflammatory cytokines and lactate. Consistently, treatment of glycolytic inhibitor 2-deoxyglucose almost completely abrogated the protection of mice from LPS-induced sepsis initiated by Zhx2 deletion in macrophages. RNA sequencing and chromatin immunoprecipitation assays confirmed that Zhx2 enhanced transcription of Pfkfb3, the glycolysis rate-limiting enzyme, via binding with Pfkfb3 promoter. Furthermore, Pfkfb3 overexpression not only rescued the reduction of macrophage glycolysis caused by Zhx2 deficiency, displaying as extracellular acidification rates and lactate production but also destroyed the resistance of mice to LPS-induced sepsis initiated by transfer of bone marrow–derived macrophages from MKO mice. These findings highlight the novel role of transcription factor Zhx2 in sepsis via regulating Pfkfb3 expression and reprogramming macrophage metabolism, which would shed new insights into the potential strategy to intervene sepsis.

Norisoboldine Attenuates Sepsis-Induced Acute Lung Injury by Modulating Macrophage Polarization <i>via</i> PKM2/HIF-1α/PGC-1α Pathway

“…Hence, regulating energy metabolism may become a new way to limit inflammatory injury. 17,18) M2 pyruvate kinase (PKM2) is one of the rate-limiting enzyme in glycolysis pathway, which can rapidly regulate its metabolic activity by changing its distribution in cytoplasm and nucleus. 19,20) In the normal state, PKM2 is mainly distributed in the cytoplasm in the form of tetramer, which plays the role of metabolic kinase activity.…”

Deficiency of Myeloid Pfkfb3 Protects Mice From Lung Edema and Cardiac Dysfunction in LPS-Induced Endotoxemia

“…Myeloid Pfkfb3 knockout-decreased macrophage inflammatory response protects mice from LPS-induced sepsis. It has been well accepted that inhibited macrophage glycolysis protects mice from LPS-induced sepsis ( 13 , 26 ). For example, inactivation of hexokinase 1 (HK1), the first rate-limiting enzyme of the glycolytic pathway, suppressed macrophage proinflammatory responses and LPS-induced sepsis in mice ( 26 , 27 ).…”

“…Each of the above flux pathways is an important regulator in inflammatory response. Assessing these pathways by glucose flux with 13 C-glucose tracer in activated Pfkfb3 WT and Pfkfb3 Mφ BMDMs will be needed in future study. Second, as macrophages are critical in the host response to infection, thereby, it remains unclear whether blocking of macrophage glycolysis and cytokine production by deletion of Pfkfb3 would impair the role of macrophages in bacterial clearance and resolution of infection-mediated sepsis.…”

“…F-2,6-BP acts as the most effective allosteric activator of 6-phosphofructo-1-kinase (PFK1), the second rate-limiting enzyme in glycolysis ( 11 , 12 ). A previous study demonstrated that zinc fingers and homeoboxes (Zhx) 2 accelerates sepsis by promoting macrophage glycolysis via Pfkfb3 ( 13 ). However, it remains unclear whether decreased macrophage glycolysis via Pfkfb3 inactivation can suppress macrophage inflammation and protect mice from LPS-induced sepsis.…”

Cellular and Exosomal Regulations of Sepsis-Induced Metabolic Alterations

“…A surge in HIF-1α levels consequently upregulate genes encoding inflammatory mediators and glycolytic proteins such as glucose transporter 1 (GLUT1), 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB3), hexokinase (HK2), pyruvate kinase (PKM2), and lactate dehydrogenase (LDH) [ 25 , 38 ]. Additionally, the transcription factor Zinc fingers and homeoboxes 2 (Zhx2) is also upregulated in macrophages after LPS stimulation and binds to the promotor region of PFKFB3 to increase its expression thereby driving glycolysis [ 39 ]. The inflammasome NLRP3 also augments glycolysis in macrophages after exposure to LPS and amyloid β through release of IL-1β [ 40 ].…”