Alterations in the gut microbiome and metabolome profiles of septic mice treated with Shen FuHuang formula

Identification of STAT3 and MYC as critical ferroptosis-related biomarkers in septic cardiomyopathy: a bioinformatics and experimental study

Ferroptosis is the well-known mechanism of septic cardiomyopathy (SCM). Bioinformatics analysis was employed to identify ferroptosis-related SCM differentially expressed genes (DEG). DEGs' functional enrichment was explored. Weighted gene co-expression network analysis (WGCNA) was employed to form gene clusters. The identified hub genes, signal transducer and activator of transcription 3 (STAT3) and myelocytomatosis (MYC) were further evaluated by generating receiver operator characteristic (ROC) curves and a nomogram prediction model. Additionally, survival rate, cardiac damage markers, and cardiac function and ferroptosis markers were evaluated in septic mouse model. STAT3 and MYC levels were measured in SCM heart tissue via immunohistochemical (IHC) staining, real-time polymerase chain reaction (qPCR) and western blot analysis. Analysis identified 225 DEGs and revealed 22 intersected genes. Of the 7 hub genes, STAT3 and MYC showed enrichment in septic heart tissue and a strong predicative ability based on AUC values. Cardiac damage, iron metabolism, and lipid peroxidation occurred in the SCM model. By experiments, STAT3 and MYC expression was increased in the SCM model. Impairment was reversed with a ferroptosis inhibitor, Fer-1. As conclusion, STAT3 and MYC are related with ferroptosis and may serve as potential SCM predictor indicators. KEY MESSAGES: Septic cardiomyopathy (SCM) often leads to high mortality in septic patients, and the diagnostic criteria still remains unclear. Ferroptosis as the pathogenic mechanism of SCM could help predict its progression and clinical outcomes. STAT3 and MYC are related with ferroptosis and may serve as potential SCM predictor biomarkers.

Identification of RRM2 as a key ferroptosis-related gene in sepsis

OBJECTIVE

Sepsis and sepsis-associated organ failure are devastating conditions for which there are no effective therapeutic agent. Several studies have demonstrated the significance of ferroptosis in sepsis. The study aimed to identify ferroptosis-related genes (FRGs) in sepsis, providing potential therapeutic targets.

METHODS

The weighted gene co-expression network analysis (WGCNA) was utilized to screen sepsis-associated genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were used to explore gene functions. Three machine learning methods were employed to identify sepsis-related hub genes. Survival and multivariate Cox regression analysis allowed further screening for the key gene RRM2 associated with prognosis. The immune infiltration analysis of the screened sepsis key genes was performed. Additionally, a cecum ligation and puncture (CLP)-induced mouse sepsis model was constructed to validate the expression of key gene in the sepsis.

RESULTS

Six sepsis-associated differentially expressed FRGs (RRM2, RPL7A, HNRNPA1, PEBP1, MYL8B and TXNIP) were screened by WGCNA and three machine learning methods analysis. Survival analysis and multivariate Cox regression analysis showed that RRM2 was a key gene in sepsis and an independent prognostic factor associated with clinicopathological and molecular features of sepsis. Immune cell infiltration analysis demonstrated that RRM2 had a connection to various immune cells, such as CD4 T cells and neutrophils. Furthermore, animal experiment demonstrated that RRM2 was highly expressed in CLP-induced septic mice, and the use of Fer-1 significantly inhibited RRM2 expression, inhibited serum inflammatory factor TNF-α, IL-6 and IL-1β expression, ameliorated intestinal injury and improved survival in septic mice.

CONCLUSION

RRM2 plays an important role in sepsis and may contribute to sepsis through the ferroptosis pathway. This study provides potential therapeutic targets for sepsis.

Shenhuangdan decoction alleviates sepsis-induced lung injury through inhibition of GSDMD-mediated pyroptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Sepsis-induced lung injury is closely associated with it remarkable morbidity and mortality. Shenhuangdan (SHD) decoction, a traditional Chinese medicine prescription, has been clinically proven to be an effective treatment for sepsis. However, the mechanism of SHD decoction in treating sepsis remains unclear.

AIM OF THE STUDY

This study aimed to evaluate the therapeutic effect of SHD decoction on sepsis-induced lung injury and its underlying mechanism.

MATERIALS AND METHODS

In this study, we established a mouse model of sepsis by cecum ligation and puncture (CLP) surgery. Firstly, seven-day survival analysis and histological staining of lung tissue were used to evaluate the therapeutic effect of SHD decoction on lung injury in septic mice. Multifactor microarray was used to detect cytokine expression changes in serum and bronchoalveolar lavage fluid (BALF). Subsequently, the main components in medicated serum of SHD decoction were inspected by Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The material basis of SHD decoction and potential interaction mechanisms were analysed by systemic pharmacology. To confirm the reliability of network pharmacology for predicting outcomes, we used molecular docking techniques to identify interactions between the core components and targets of SHD. Finally, TUNEL staining, immunofluorescence and western blotting were used to explore the mechanism of SHD decoction through the inhibition of GSDMD-mediated pyroptosis in septic mice.

RESULTS

SHD was found to be effective in reducing the mortality and alleviating lung pathological damage in septic mice. Multifactor microarray results showed that SHD can reduce the expression of inflammation factors (IL-18, IL-1β, IL-5, IL-6 and TNF-α) in serum and BALF of septic mice. There were 22 major blood-entry components detected by UPLC-MS/MS. Then, combined with the network pharmacological analysis, it is evident that the main components of SHD for sepsis are Renshen-ginsenoside Rh2, Danshen-tanshinone IIA and Dahuang-rhein. The main targets were IL-1β and caspase-1, which were related to GSDMD-mediated pyroptosis signalling pathway. Molecular docking exhibited that Renshen-ginsenoside Rh2, Danshen-tanshinone IIA and Dahuang-rhein can closely bind to GSDMD, IL-1β and caspase-1. In addition, TUNEL staining and immunohistochemistry demonstrated that SHD alleviated the expression of GSDMD protein. The western blotting showed that SHD significantly inhibited the protein expression levels of NLRP3, GSDMD, GSDMD-N, cleved caspase-1, caspase-1 and ASC in lung tissue.

CONCLUSIONS

Our study revealed that SHD improves CLP-induced lung injury by blocking the GSDMD-mediated pyroptosis signalling pathway in septic mice. This study provides evidence to support that SHD had a potential therapeutic effect on sepsis.