Longitudinal Single-Cell Transcriptomics Reveals a Role for Serpina3n-Mediated Resolution of Inflammation in a Mouse Colitis Model

BACKGROUND & AIMS

Proper resolution of inflammation is essential to maintaining homeostasis, which is important as a dysregulated inflammatory response has adverse consequences, even being regarded as a hallmark of cancer. However, our picture of dynamic changes during inflammation remains far from comprehensive.

METHODS

Here we used single-cell transcriptomics to elucidate changes in distinct cell types and their interactions in a mouse model of chemically induced colitis.

RESULTS

Our analysis highlights the stromal cell population of the colon functions as a hub with dynamically changing roles over time. Importantly, we found that Serpina3n, a serine protease inhibitor, is specifically expressed in stromal cell clusters as inflammation resolves, interacting with a potential target, elastase. Indeed, genetic ablation of the Serpina3n gene delays resolution of induced inflammation. Furthermore, systemic Serpina3n administration promoted the resolution of inflammation, ameliorating colitis symptoms.

CONCLUSIONS

This study provides a comprehensive, single-cell understanding of cell-cell interactions during colorectal inflammation and reveals a potential therapeutic target that leverages inflammation resolution.

Enteric Neuromics: How High-Throughput "Omics" Deepens Our Understanding of Enteric Nervous System Genetic Architecture

Recent accessibility to specialized high-throughput "omics" technologies including single cell RNA sequencing allows researchers to capture cell type- and subtype-specific expression signatures. These omics methods are used in the enteric nervous system (ENS) to identify potential subtypes of enteric neurons and glia. ENS omics data support the known gene and/or protein expression of functional neuronal and glial cell subtypes and suggest expression patterns of novel subtypes. Gene and protein expression patterns can be further used to infer cellular function and implications in human disease. In this review we discuss how high-throughput "omics" data add additional depth to the understanding of established functional subtypes of ENS cells and raise new questions by suggesting novel ENS cell subtypes with unique gene and protein expression patterns. Then we investigate the changes in these expression patterns during pathology observed by omics research. Although current ENS omics studies provide a plethora of novel data and therefore answers, they equally create new questions and routes for future study.

Single cell RNA-Sequencing Reveals Mast Cells Enhance Mononuclear Phagocytes Infiltration in Bladder Cancer Microenvironment

Objective: Investigating the interaction between Mast cells (MCs) and Mononuclear Phagocytes (MPs) in the tumor microenvironment (TME) of blader cancer (BCa) to uncover potential immunotherapeutic targets. Methods: Single-cell RNA sequencing (scRNA-Seq) was conducted on 12 BCa patients to identify distinct subgroups of MCs and MPs. Transcriptome data was analyzed to characterize the phenotype, gene enrichment, cell-cell communication, and biological processes. The expression levels of cytokines were assessed by enzyme-linked immunosorbent assay (ELISA), while the chemotactic effects of cytokines were evaluated through Transwell assay. Results: In muscle-invasive bladder cancer (MIBC), the proportion of interferon-stimulated MC subtype (Mast-ISG15) increased. Mast-IL13 subgroup and Mast-CCL2 subgroups were functionally enriched in interferon (IFN) and nuclear factor kappa-B (NF-κB) signaling pathways. The Mast-CCL2 subgroup overexpressed the CCL2 gene, which could chemoattract MPs through CCL2. In vitro experiments confirmed that under stimulation, activated MCs activated IFN and NF-κB signaling, increasing the secretion of CCL2 and IL-13, chemoattracted THP-1 monocyte. Conclusion: This study revealed the vital role of MCs in shaping the TME of BCa. And provides new insights for the precise treatment of BCa.

Ferroptosis and WDFY4 as novel targets for immunotherapy of lung adenocarcinoma

BACKGROUND

Lung cancer exhibits the world's highest mortality rate among malignant cancers worldwide, thereby presenting a significant global challenge in terms of reducing patient mortality. In the field of oncology, targeted immunotherapy has emerged as a novel therapeutic approach for lung cancer. This study aims to explore potential targets for immunotherapy in lung adenocarcinoma (LUAD) through the analysis of Ferroptosis Index (FPI) and Single Cell RNA-Sequencing (scRNA-seq) data. The findings of this research can potentially offer valuable insights for improving LUAD immunotherapy strategies and informing clinical decision-making.

METHODS

Firstly, the relationship between survival and ferroptosis in LUAD patients was analyzed by FPI. Subsequently, the association between ferroptosis and infiltration and regulation of immune cells was explored by immune infiltration analysis and correlation statistics. Lastly, the relationship between major infiltrating immune cell populations and related pathways and prognosis of LUAD patients was analyzed by GSEA and GSVA. To screen out core genes regulating infiltration of immune cell populations, scRNA-seq data of cancer and para-cancerous tissues of LUAD patients were downloaded, followed by cell clustering analysis, cell identification of core subpopulations, pseudotime analysis, single-cell GSVA and pathway enrichment analysis, and identification and functional analysis of core regulatory genes. Moreover, the expression levels of core functional genes in LUAD tissue microarray were detected by immunohistochemistry, and its relationship with the prognosis of LUAD patients was verified. Finally, we used lentivirus with WDFY4 to transfect LUAD A549 cells. CCK-8, flow cytometry apoptosis detection, Scratch wound healing assay, Transwell migration assay, Xenograft nude mice model, immunohistochemical analysis and other experimental methods were used to explore the biological effects of WDFY4 on LUAD in vitro and in vivo.

RESULTS

Survival analysis of FPI values in LUAD patients revealed a positive correlation between smaller FPI values and longer overall survival. Immuno-infiltration analysis and its correlation with FPI values revealed that B cells were most strongly associated with ferroptosis. Ferroptosis of cancer cells could promote infiltration and activation of B cell populations, and LUAD patients with more infiltration of B cell populations had longer long-term survival. scRNA-seq data analysis indicated that the B cell population is one of the major cell populations infiltrated by immune cells in LUAD. During the later phases of B cell differentiation in LUAD, there was a decrease in the expression levels of ACAP1, LINC00926, TLR10, MS4A1, WDFY4, and TRIM22 genes, whereas the expression levels of TMEM59, TP53INP1, and METTL7A genes were elevated. The protein-protein interaction (PPI) network analysis indicated that WDFY4 plays a crucial role in regulating B cell differentiation in LUAD. Immunohistochemical analysis of LUAD tissue microarray revealed a significant downregulation of WDFY4 expression, which was closely related to the occurrence sites of LUAD. Moreover, LUAD patients with a low WDFY4 expression exhibited a poorer prognosis. Additionally, experimental findings demonstrated that the overexpression of WDFY4 could inhibit the proliferation and metastasis of A549 cells while promoting apoptosis. It was also confirmed that WDFY4 could inhibit cancer growth in vivo.

CONCLUSIONS

The results indicate that promoting infiltration and activation of B cell populations could improve the long-term survival of LUAD patients, thereby offering a potential novel immunotherapeutic approach for LUAD. Besides, the promotion of cancer cell ferroptosis and upregulation of WDFY4 expression have been shown to induce the infiltration and activation of B cell populations. Furthermore, the overexpression of WDFY4 can significantly inhibit the growth of lung adenocarcinoma in vitro and in vivo, highlighting its potential as a target for immunotherapy in LUAD.