Rapidly Inhibiting the Inflammatory Cytokine Storms and Restoring Cellular Homeostasis to Alleviate Sepsis by Blocking Pyroptosis and Mitochondrial Apoptosis Pathways

Applications of peptides in nanosystems for diagnosing and managing bacterial sepsis

Sepsis represents a critical medical condition stemming from an imbalanced host immune response to infections, which is linked to a significant burden of disease. Despite substantial efforts in laboratory and clinical research, sepsis remains a prominent contributor to mortality worldwide. Nanotechnology presents innovative opportunities for the advancement of sepsis diagnosis and treatment. Due to their unique properties, including diversity, ease of synthesis, biocompatibility, high specificity, and excellent pharmacological efficacy, peptides hold great potential as part of nanotechnology approaches against sepsis. Herein, we present a comprehensive and up-to-date review of the applications of peptides in nanosystems for combating sepsis, with the potential to expedite diagnosis and enhance management outcomes. Firstly, sepsis pathophysiology, antisepsis drug targets, current modalities in management and diagnosis with their limitations, and the potential of peptides to advance the diagnosis and management of sepsis have been adequately addressed. The applications have been organized into diagnostic or managing applications, with the last one being further sub-organized into nano-delivered bioactive peptides with antimicrobial or anti-inflammatory activity, peptides as targeting moieties on the surface of nanosystems against sepsis, and peptides as nanocarriers for antisepsis agents. The studies have been grouped thematically and discussed, emphasizing the constructed nanosystem, physicochemical properties, and peptide-imparted enhancement in diagnostic and therapeutic efficacy. The strengths, limitations, and research gaps in each section have been elaborated. Finally, current challenges and potential future paths to enhance the use of peptides in nanosystems for combating sepsis have been deliberately spotlighted. This review reaffirms peptides' potential as promising biomaterials within nanotechnology strategies aimed at improving sepsis diagnosis and management.

Discovery of a novel pyroptosis inhibitor acting though modulating glutathionylation to suppress NLRP3-related signal pathway

Pyroptosis is a proinflammatory type of regulated cell death and has been involved in many pathological processes. Inhibition of pyroptosis is thought to be a promising strategy for the treatment of related diseases. Here, we performed a phenotypic screening against NLRP3-dependent pyroptosis and obtained the novel compound N77 after structure optimization. N77 showed a half-maximal effective concentration (EC50) of 0.070 ± 0.008 μM against cell pyroptosis induced by nigericin, and exhibited a remarkable ability to prevent NLRP3-dependent inflammasome activation and the release of IL-1β. Chemical proteomics revealed the biological target of N77 to be glutathione-S-transferase Mu 1 (GSTM1); our mechanism of action studies indicated that GSTM1 might act as a negative regulator of NLRP3 inflammasome activation by modulating the glutathionylation of caspase-1. In vivo, N77 substantially alleviated the inflammatory reaction in a pyroptosis-related acute keratitis model. Overall, we identified a novel pyroptosis inhibitor and revealed a new regulatory mechanism of pyroptosis. Our findings suggest an alternative potential therapeutic strategy for pyroptosis-related diseases.

Zn-Shik-PEG nanoparticles alleviate inflammation and multi-organ damage in sepsis

Sepsis is defined as a life-threatening organ dysfunction caused by excessive formation of reactive oxygen species (ROS) and dysregulated inflammatory response. Previous studies have reported that shikonin (Shik) possess prominent anti-inflammatory and antioxidant effects and holds promise as a potential therapeutic drug for sepsis. However, the poor water solubility and the relatively high toxicity of shikonin hamper its clinical application. To address this challenge, we constructed Zn2+-shikonin nanoparticles, hereafter Zn-Shik-PEG NPs, based on an organic-inorganic hybridization strategy of metal-polyphenol coordination to improve the aqueous solubility and biosafety of shikonin. Mechanistic studies suggest that Zn-Shik-PEG NPs could effectively clear intracellular ROS via regulating the Nrf2/HO-1 pathway, meanwhile Zn-Shik-PEG NPs could inhibit NLRP3 inflammasome-mediated activation of inflammation and apoptosis by regulating the AMPK/SIRT1 pathway. As a result, the Zn-Shik-PEG NPs demonstrated excellent therapeutic efficacies in lipopolysaccharide (LPS) as well as cecal ligation puncture (CLP) induced sepsis model. These findings suggest that Zn-Shik-PEG NPs may have therapeutic potential for the treatment of other ROS-associated and inflammatory diseases.

Pyroptosis-induced inflammation and tissue damage

Pyroptosis is a programmed necrotic cell death executed by gasdermins, a family of pore-forming proteins. The cleavage of gasdermins by specific proteases enables their pore-forming activity. The activation of the prototype member of the gasdermin family, gasdermin D (GSDMD), is linked to innate immune monitoring by inflammasomes. Additional gasdermins such as GSDMA, GSDMB, GSDMC, and GSDME are activated by inflammasome-independent mechanisms. Pyroptosis is emerging as a key host defense strategy against pathogens. However, excessive pyroptosis causes cytokine storm and detrimental inflammation leading to tissue damage and organ dysfunction. Consequently, dysregulated pyroptotic responses contribute to the pathogenesis of various diseases, including sepsis, atherosclerosis, acute respiratory distress syndrome, and neurodegenerative disorders. This review will discuss the inflammatory consequences of pyroptosis and the mechanisms of pyroptosis-induced tissue damage and disease pathogenesis.

MESP1-knockdown inhibits the proliferation and epithelial mesenchymal transition of hepatocellular carcinoma and enhances the tumor-suppressive effect of 5-fluorouracil

Primary liver hepatocellular carcinoma (HCC) is the third most deadly malignancy worldwide,in part, because it is often diagnosed at an advanced stage. Thus, molecular markers are needed to aid in the early diagnosis and treatment of HCC. Expression of abnormal mesoderm posterior-1 (MESP1) promotes tumorigenesis; however,its role in the regulation of HCC proliferation, apoptosis,and invasion is unknown. Here,we analyzed data in The Cancer Genome Atlas (TCGA)and Genotype Tissue Expression (GTEx) databases on the pan-cancer expression of MESP1 and its relationship with clinical characteristics and prognosis of patients with HCC. The expression of MESP1 was measured in 48 HCC tissues using immunohistochemical staining,and the results were correlated with clinical stage, tumor differentiation, tumor size,and metastasis. MESP1 expression was downregulated using small interfering RNA (siRNA) in the HCC cell lines HepG2 and Hep3B,and cell viability, proliferation,cell cycle, apoptosis,and invasion were analyzed. Finally,we also evaluated the tumor suppression effect of MESP1 downregulation combined with 5-fluorouracil (5-FU) treatment. Our results showed that MESP1 is a pan-oncogene associated with poor prognosis in patients with HCC. siRNA-induced downregulation of MESP1 expression in HepG2 and Hep3B cells exhibited downregulation of β-catenin and GSK3β expression 48h after transfection, along with an increase in apoptosis rate, arrest in the G1-S phase,and a decrease in mitochondrial membrane potential. Moreover,the expression levels of c-Myc, PARP1, bcl2, Snail1, MMP9, and immune checkpoint genes (TIGIT, CTLA4,LAG3,CD274,and PDCD1) were downregulated, while those of caspase3 and E-cadherin were upregulated. Tumor cells also showed decreased migration ability. Furthermore, siRNA interference of MESP1 expression combined with 5-FU-treatment of HCC cells significantly enhanced the G1-S phase block and apoptosis. MESP1 showed an aberrant high expression in HCC and was associated with poor clinical outcomes; therefore, MESP1 may be a potential target for the diagnosis and treatment of HCC.