Since the outbreak of the novel coronavirus disease 2019 (COVID-19) in 2019, many countries have successively developed a variety of vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, with the continuous spread of SARS-CoV-2, it has evolved several variants; as a result, prevention and control of the pandemic of SARS-CoV-2 has become more important. Among these variants, the Omicron variant has higher transmissibility and immune escape ability and is the main variant causing a large number of COVID-19 breakthrough infection, thus, presenting new challenges to pandemic prevention and control. Hence, we review the biological characteristics of the Omicron variant and discuss the current status and possible mechanism of breakthrough infection caused by the Omicron variant in order to provide insights into the prevention and control of the pandemic of SARS-CoV-2.

Colorectal cancer (CRC) is one of the most common cancers worldwide and inflammation is believed to play an important role in CRC. In this study, we comprehensively analyzed the causal association between 91 circulating inflammatory cytokines and the risk of CRC using Mendelian randomization (MR). Based on genome-wide association study summary statistics, we examined the causal effects of 91 circulating inflammatory cytokines on CRC. A series of MR methods, including bidirectional MR, replication sample MR, and multivariable MR, were employed to provide more robust causal estimates. After the validation with 3 MR methods and a series of sensitivity analyses, 2 circulating inflammatory factors were found to be significantly associated with the risk of CRC at the genetic level. Specifically, genetically predicted circulating levels of glial cell line-derived neurotrophic factor (GDNF) (OR = 1.12; 95% CI: 1.05–1.19; P = 2.72 × 10^-4) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) (OR = 0.93; 95% CI: 0.91–0.99; P = 1.00 × 10^-2) exerted causal effects on CRC risk. In conclusion, this study suggests that increased circulating levels of GDNF and TRAIL are associated with a higher and lower risk of CRC, respectively. GDNF and TRAIL may be 2 potential therapeutic targets that deserve future investigation.

Sepsis remains a major cause of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), conditions characterized by high mortality and limited therapeutic options. Among the diverse inflammatory pathways implicated in their pathogenesis, the CXCL12/CXCR4 chemokine axis has gained increasing attention for its dual capacity to drive acute inflammation while also supporting tissue repair. Although numerous studies have investigated this signaling pathway, an integrated framework that reconciles its context-dependent functions, upstream regulatory mechanisms, and translational relevance has been lacking. In this review, we synthesize current evidence on the multifaceted roles of the CXCL12/CXCR4 axis in sepsis-induced ALI, highlighting its cell-type-specific effects in neutrophils, macrophages, alveolar epithelial cells, and endothelial cells through downstream pathways such as NF-κB, MAPK, and PI3K/Akt. We further evaluate emerging therapeutic approaches, including small-molecule antagonists (e.g., AMD3100), natural products, and epigenetic modulators. Newly added sections summarize the upstream regulation of CXCL12 by hypoxia, cytokines, and epigenetic factors, discuss the regulatory influence of the alternative receptor CXCR7/ACKR3, and differentiate preclinical insights from human clinical observations. Finally, we outline key obstacles to clinical translation and propose future directions to develop precision medicine strategies that more effectively target this axis. Collectively, our analysis suggests that although the CXCL12/CXCR4 pathway represents a promising target for ALI/ARDS therapy, its context-dependent and cell-specific actions demand carefully tailored modulation rather than uniform inhibition.

The mechanisms underlying sepsis remain poorly understood and specific therapeutic options remain lacking. Accumulating evidence suggests that butyrate metabolism and oxidative stress (OS) are involved in the pathogenesis of sepsis. This study aims to elucidate molecular characteristics of butyrate metabolism and OS-related genes in sepsis and find potential therapeutic targets. Using sepsis-related datasets, 876 differential expression genes (DEGs) were screened and intersected with butyrate metabolism and OS-related genes to yield 8 differentially expressed butyrate metabolism and OS-related genes (DEBORGs). Machine learning algorithms finally identified 3 feature genes (ALDH1A1, CYP1B1, and GADD45A) with favourable diagnostic values for sepsis. CIBERSORT immune infiltration analysis demonstrated strong associations between feature genes and the infiltration proportions of various immune cell types, such as monocyte, macrophage, and neutrophil. Cellular experiment and prospectively collected clinical samples were utilized to validate the expression levels and diagnostic efficacy of feature genes. The scRNA-seq analysis indicated that monocyte plays a crucial role in mediating the effect of feature genes on sepsis. This study elucidates that ALDH1A1, CYP1B1, and GADD45A are feature genes linked to butyrate metabolism and OS in sepsis, with monocytes being the primary cells involved, providing novel insights into the sepsis pathogenesis and potential therapeutic targets.

Idiopathic pulmonary fibrosis (IPF) and Crohn’s disease (CD) share overlapping immune and fibrotic processes, yet their convergent molecular mechanisms remain poorly defined. Here, we performed an integrative transcriptomic analysis of nine public datasets to identify shared transcriptional signatures across IPF and CD. The main discovery and validation analyses were based on bulk transcriptomic datasets and combined differential expression profiling, weighted gene co-expression network analysis, and machine-learning–based feature prioritization. We identified 28 shared disease-associated module genes, from which three core genes—ZNF395, EEF2K, and BAHD1—were prioritized based on reproducibility and biological consistency. Functional enrichment analysis revealed their involvement in immune regulation, protein homeostasis, and stress-response pathways. Immune deconvolution and supportive single-cell RNA-sequencing further suggested associations between these genes and T-cell and myeloid cell populations, suggesting coordinated immune-fibrotic regulation. Experimental validation in a repetitive bleomycin challenge model and TGF-β1-stimulated fibroblasts showed consistent downregulation of these genes during fibrotic remodeling, supporting their association with fibrosis-related transcriptional states. Collectively, our study identifies conserved immune–fibrotic transcriptional programs shared across intestinal inflammation and pulmonary fibrosis, providing a hypothesis-generating molecular framework for understanding extraintestinal pulmonary involvement in Crohn’s disease and prioritizing candidate genes for future mechanistic investigation.

While recent studies suggested a potential causal link between type 1 diabetes mellitus (T1DM) but not type 2 diabetes mellitus (T2DM) and idiopathic pulmonary fibrosis (IPF), the involved mechanism remains unclear. Here, using a Mendelian randomization (MR) approach, we verified the causal relationship between the two types of diabetes mellitus and IPF and investigated the possible role of inflammation in the association between diabetes mellitus and IPF. Based on genome-wide association study (GWAS) summary data of T1DM, T2DM, and IPF, the univariable MR, multivariable MR (MVMR), and mediation MR were successively used to analyze the causal relationship. Inverse variance weighted was used as the main method to infer the causal effect, together with a series of sensitivity analyses. The univariable MR showed that only T1DM increased the risk of IPF, and there was no significant causal relationship between T2DM and IPF. The MVMR further verified that there was an independent direct causal effect of T1DM on IPF. Further mediation analysis showed that this effect was partly mediated by increasing C-X-C motif chemokine ligand 10 (CXCL10) and interleukin-12 subunit beta (IL-12B). In conclusion, T1DM is related to an increased risk of IPF. Notably, the causal effect was partially mediated by CXCL10 and IL-12B. Hence, monitoring T1DM patients may help in the early detection and prevention of IPF.