RESUMO
Hypomagnesemia is a significant risk factor for critically ill patients to develop sepsis, a life-threatening disease with a mortality rate over 25%. Our clinic data analysis showed that hypomagnesemia is associated with a decreased monocyte count in septic patients. At the cellular level, we found that Mg2+ inhibits pyroptosis. Specifically, Mg2+ limits the oligomerization and membrane localization of gasdermin D N-terminal (GSDMD-NT) upon the activation of either the canonical or noncanonical pyroptotic pathway. Mechanistically, we demonstrated that Ca2+ influx is a prerequisite for the function of GSDMD-NT. Mg2+ blocks Ca2+ influx by inhibiting the ATP-gated Ca2+ channel P2X7, thereby impeding the function of GSDMD-NT and inhibiting lipopolysaccharide (LPS)-induced noncanonical pyroptosis. Furthermore, Mg2+ administration protects mice from LPS-induced lethal septic shock. Together, our data reveal the underlying mechanism of how Mg2+ inhibits pyroptosis and suggest potential clinic applications of magnesium supplementation for sepsis prevention and treatment.
Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Magnésio/farmacologia , Proteínas de Ligação a Fosfato/antagonistas & inibidores , Piroptose/efeitos dos fármacos , Sepse/tratamento farmacológico , Animais , Células Cultivadas , Células HEK293 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Lipopolissacarídeos/administração & dosagem , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Magnésio/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas de Ligação a Fosfato/metabolismo , Sepse/metabolismo , Sepse/patologiaRESUMO
A defining goal of synthetic biology is to develop biomaterials with superior performance and versatility. Here we introduce a purely genetically encoded and self-assembling biopolymer based on the SpyTag-SpyCatcher chemistry. We show the application of this polymer for highly efficient uranyl binding and extraction from aqueous solutions, by embedding two functional modules-the superuranyl binding protein and the monomeric streptavidin-to the polymer via genetic fusion. We further provide a modeling strategy for predicting the polymer's physical properties, and experimentally demonstrate the autosecretion of component monomers from bacterial cells. The potential of multifunctionalization, in conjunction with the genetic design and production pipeline, underscores the advantage of the SpyTag-SpyCatcher biopolymers for applications beyond trace metal enrichment and environmental remediation.