SUMO conjugation regulates the activity of the Integrator complex

Identification of cuproptosis-related gene clusters and immune cell infiltration in major burns based on machine learning models and experimental validation

Introduction

Burns are a global public health problem. Major burns can stimulate the body to enter a stress state, thereby increasing the risk of infection and adversely affecting the patient's prognosis. Recently, it has been discovered that cuproptosis, a form of cell death, is associated with various diseases. Our research aims to explore the molecular clusters associated with cuproptosis in major burns and construct predictive models.

Methods

We analyzed the expression and immune infiltration characteristics of cuproptosis-related factors in major burn based on the GSE37069 dataset. Using 553 samples from major burn patients, we explored the molecular clusters based on cuproptosis-related genes and their associated immune cell infiltrates. The WGCNA was utilized to identify cluster-specific genes. Subsequently, the performance of different machine learning models was compared to select the optimal model. The effectiveness of the predictive model was validated using Nomogram, calibration curves, decision curves, and an external dataset. Finally, five core genes related to cuproptosis and major burn have been was validated using RT-qPCR.

Results

In both major burn and normal samples, we determined the cuproptosis-related genes associated with major burns through WGCNA analysis. Through immune infiltrate profiling analysis, we found significant immune differences between different clusters. When K=2, the clustering number is the most stable. GSVA analysis shows that specific genes in cluster 2 are closely associated with various functions. After identifying the cross-core genes, machine learning models indicate that generalized linear models have better accuracy. Ultimately, a generalized linear model for five highly correlated genes was constructed, and validation with an external dataset showed an AUC of 0.982. The accuracy of the model was further verified through calibration curves, decision curves, and modal graphs. Further analysis of clinical relevance revealed that these correlated genes were closely related to time of injury.

Conclusion

This study has revealed the intricate relationship between cuproptosis and major burns. Research has identified 15 cuproptosis-related genes that are associated with major burn. Through a machine learning model, five core genes related to cuproptosis and major burn have been selected and validated.

SUMO proteases: from cellular functions to disease

Posttranslational modification by small ubiquitin-like modifiers (SUMOs) is critical in regulating diverse cellular processes including gene expression, cell cycle progression, genome integrity, cellular metabolism, and inflammation and immunity. The covalent attachment of SUMOs to target proteins is highly dynamic and reversible through the concerted action of SUMO conjugating and deconjugating enzymes. In mammalian cells, sentrin-specific proteases (SENPs) are the most abundant family of deconjugating enzymes. This review highlights recent advances in our knowledge of the substrates and cellular and physiological processes controlled by SENPs. Notably, SENPs are emerging as significant players in cancer, as well as in other diseases, making them attractive targets for therapeutic intervention. Consequently, a growing amount of effort in the field is being directed towards the development of SENP inhibitors.

SUMOylation and DeSUMOylation: Prospective therapeutic targets in cancer

The SUMO family is a type of ubiquitin-like protein modification molecule. Its protein modification mechanism is similar to that of ubiquitination: both involve modifier-activating enzyme E1, conjugating enzyme E2 and substrate-specific ligase E3. However, polyubiquitination can lead to the degradation of substrate proteins, while poly-SUMOylation only leads to the degradation of substrate proteins through the proteasome pathway after being recognized by ubiquitin as a signal factor. There are currently five reported subtypes in the SUMO family, namely SUMO1-5. As a reversible dynamic modification, intracellular sentrin/SUMO-specific proteases (SENPs) mainly regulate the reverse reaction pathway of SUMOylation. The SUMOylation modification system affects the localization, activation and turnover of proteins in cells and participates in regulating most nuclear and extranuclear molecular reactions. Abnormal expression of proteins related to the SUMOylation pathway is commonly observed in tumors, indicating that this pathway is closely related to tumor occurrence, metastasis and invasion. This review mainly discusses the composition of members in the protein family related to SUMOylation pathways, mutual connections between SUMOylation and other post-translational modifications on proteins as well as therapeutic drugs developed based on these pathways.

Go along to get along: Integrator at active replication forks defuses co-directional transcription-replication conflicts

There has been growing appreciation that transcription is an endogenous source of replication stress and must be coordinated with replication. In this issue, Bhowmick et al.¹ uncover a protective mechanism that prevents co-directional transcription-replication conflicts (TRCs) from becoming genotoxic.