Single-cell sequencing analysis reveals gastric cancer microenvironment cells respond vastly different to oxidative stress

Alleviation effect of taxifolin on diquat-induced damage to porcine intestinal epithelial cells

Oxidative stress is considered to be a major cause of numerous intestinal diseases, and taxifolin (TA) possesses a variety of pharmacological properties that promote health and prevent disease. This study intends to determine the ability of TA to alleviate oxidative stress induced by diquat (DIQ) in porcine intestinal epithelial cells (IPEC-J2 cells). After being pretreated with 150 μM TA for 24 h, IPEC-J2 cells were treated with 0.5 mM DIQ for 6 h to cause oxidative stress. The results demonstrated that TA pretreatment increased cell viability and proliferation, significantly inhibited the DIQ-induced reductions in cell proliferation and cell viability, and ameliorated the intestinal barrier by up-regulating the expression levels of Claudin1 and Occludin. Furthermore, TA pretreatment weakened the DIQ-induced inflammatory response through reducing the gene expression of proinflammatory factors (IL-6 and IL-8) and increasing the antioxidant gene expression level, possibly through activating the Nrf2 signaling pathway. Taken together, these findings demonstrate that TA is a potent antioxidant that attenuates cytotoxicity and inflammation, protects cellular barrier integrity, and improves antioxidant function in DIQ-stimulated IPEC-J2 cells. This research explores the role of TA in mitigating intestinal oxidative stress damage and its potential as an eco-friendly feed additive in pig farming.

Use of tryptic peptide MALDI mass spectrometry imaging to identify the spatial proteomic landscape of colorectal cancer liver metastases

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths worldwide. CRC liver metastases (CRLM) are often resistant to conventional treatments, with high rates of recurrence. Therefore, it is crucial to identify biomarkers for CRLM patients that predict cancer progression. This study utilised matrix-assisted laser desorption/ionisation mass spectrometry imaging (MALDI-MSI) in combination with liquid chromatography-tandem mass spectrometry (LC-MS/MS) to spatially map the CRLM tumour proteome. CRLM tissue microarrays (TMAs) of 84 patients were analysed using tryptic peptide MALDI-MSI to spatially monitor peptide abundances across CRLM tissues. Abundance of peptides was compared between tumour vs stroma, male vs female and across three groups of patients based on overall survival (0-3 years, 4-6 years, and 7+ years). Peptides were then characterised and matched using LC-MS/MS. A total of 471 potential peptides were identified by MALDI-MSI. Our results show that two unidentified m/z values (1589.876 and 1092.727) had significantly higher intensities in tumours compared to stroma. Ten m/z values were identified to have correlation with biological sex. Survival analysis identified three peptides (Histone H4, Haemoglobin subunit alpha, and Inosine-5'-monophosphate dehydrogenase 2) and two unidentified m/z values (1305.840 and 1661.060) that were significantly higher in patients with shorter survival (0-3 years relative to 4-6 years and 7+ years). This is the first study using MALDI-MSI, combined with LC-MS/MS, on a large cohort of CRLM patients to identify the spatial proteome in this malignancy. Further, we identify several protein candidates that may be suitable for drug targeting or for future prognostic biomarker development.

Decreased oxidative stress response and oxidant detoxification of skin during aging

Oxidative stress plays an important role in the skin aging process; however, the mechanisms are not fully elucidated. Especially the changes in various types of skin cells with aging and the key oxidative stress-related genes that play a regulatory role are not clear. In this study, single-cell RNA sequencing data and microarray transcriptome data were used to explore the changes in oxidative stress response and oxidant detoxification capacity of skin cells during aging and oxidative stress-related genes potentially involved in regulating skin aging were searched. The oxidative stress response and oxidant detoxification ability were weakened in the elderly compared with those of the young. Among the different types of skin cells, keratinocytes, melanocytes, vascular endothelial cells, fibroblasts, and lymphatic endothelial cells exhibited a stronger oxidative stress response and oxidant detoxification ability, while immune cells exhibited a weaker oxidative stress response and detoxification capacity. During aging, the oxidative stress response and oxidant detoxification capacity of keratinocytes, fibroblasts, macrophages, and vascular endothelial cells were significantly weakened. Annexin A1 (ANXA1) and Apolipoprotein E (APOE) may be key oxidative stress-related genes affecting skin aging.

Non-Coding RNAs: Foes or Friends for Targeting Tumor Microenvironment

Non-coding RNAs (ncRNAs) are a group of molecules critical for cell development and growth regulation. They are key regulators of important cellular pathways in the tumor microenvironment. To analyze ncRNAs in the tumor microenvironment, the use of RNA sequencing technology has revolutionized the field. The advancement of this technique has broadened our understanding of the molecular biology of cancer, presenting abundant possibilities for the exploration of novel biomarkers for cancer treatment. In this review, we will summarize recent achievements in understanding the complex role of ncRNA in the tumor microenvironment, we will report the latest studies on the tumor microenvironment using RNA sequencing, and we will discuss the potential use of ncRNAs as therapeutics for the treatment of cancer.

Identification of Basement Membrane-Related Signatures in Gastric Cancer

BACKGROUND

The basement membrane (BM) serves as a major barrier to impede tumor cell invasion and extravasation during metastasis. However, the associations between BM-related genes and GC remain unclear.

METHODS

RNA expression data and corresponding clinical information of STAD samples were downloaded from the TCGA database. We identified BM-related subtypes and constructed a BM-related gene prognostic model using lasso-Cox regression analysis. We also investigated the single-cell properties of prognostic-related genes and the TME characteristic, TMB status, and chemotherapy response in high- and low-risk groups. Finally, we verified our results in the GEPIA database and human tissue specimens.

RESULTS

A six-gene lasso Cox regression model (APOD, CAPN6, GPC3, PDK4, SLC7A2, SVEP1) was developed. Activated CD4+ T cells and follicular T cells were shown to infiltrate more widely in the low-risk group. The low-risk group harbored significantly higher TMB and better prognosis, favoring immunotherapy.

CONCLUSIONS

We constructed a six-gene BM-related prognostic model for predicting GC prognosis, immune cell infiltration, TMB status, and chemotherapy response. This research provides new ideas for developing more effective individualized treatment of GC patients.

Stevioside Improves Antioxidant Capacity and Intestinal Barrier Function while Attenuating Inflammation and Apoptosis by Regulating the NF-κB/MAPK Pathways in Diquat-Induced Oxidative Stress of IPEC-J2 Cells

As a natural sweetener, stevioside is extracted from Stevia rebaudiana Bertoni and possesses potent antioxidant activity. However, little information is known about its protective role in maintaining the intestinal epithelial cells health under oxidative stress. The aim of this study was to investigate the protective effects and underlying mechanisms of stevioside on alleviating inflammation, apoptosis, and improving antioxidant capacity in intestinal porcine epithelial cells (IPEC-J2) under oxidative stress by diquat. The results demonstrated that the pretreatment with stevioside (250 μM) for 6 h increased cell viability and proliferation and prevented apoptosis induced by diquat at 1000 μM for 6 h in IPEC-J2 cells, compared with the diquat alone-treated cells. Importantly, stevioside pretreatment significantly reduced ROS and MDA production as well as upregulated T-SOD, CAT, and GSH-Px activity. Moreover, it also decreased cell permeability and improved intestinal barrier functions by significantly upregulating the tight junction protein abundances of claudin-1, occludin, and ZO-1. At the same time, stevioside significantly down-regulated the secretion and gene expression of IL-6, IL-8, and TNF-α and decreased the phosphorylation levels of NF-κB, IκB, and ERK1/2 compared with the diquat alone group. Taken together, this study demonstrated that stevioside alleviated diquat-stimulated cytotoxicity, inflammation, and apoptosis in IPEC-J2 cells, protecting cellular barrier integrity and mitigating oxidative stress by interfering with the NF-κB and MAPK signaling pathways.

Deciphering the sequential changes of monocytes/macrophages in the progression of IDD with longitudinal approach using single-cell transcriptome

Intervertebral disk degeneration (IDD) is a chronic inflammatory disease with intricate connections between immune infiltration and oxidative stress (OS). Complex cell niches exist in degenerative intervertebral disk (IVD) and interact with each other and regulate the disk homeostasis together. However, few studies have used longitudinal approach to describe the immune response of IDD progression. Here, we conducted conjoint analysis of bulk-RNA sequencing and single-cell sequencing, together with a series of techniques like weighted gene co-expression network analysis (WGCNA), immune infiltration analysis, and differential analysis, to systematically decipher the difference in OS-related functions of different cell populations within degenerative IVD tissues, and further depicted the longitudinal alterations of immune cells, especially monocytes/macrophages in the progression of IDD. The OS-related genes CYP1A1, MMP1, CCND1, and NQO1 are highly expressed and might be diagnostic biomarkers for the progression of IDD. Further landscape of IVD microenvironment showed distinct changes in cell proportions and characteristics at late degeneration compared to early degeneration of IDD. Monocytes/macrophages were classified into five distinct subpopulations with different roles. The trajectory lineage analysis revealed transcriptome alterations from effector monocytes/macrophages and regulatory macrophages to other subtypes during the evolution process and identified monocytes/macrophage subpopulations that had rapidly experienced the activation of inflammatory or anti-inflammatory responses. This study further proposed that personalized therapeutic strategies are needed to be formulated based on specific monocyte/macrophage subtypes and degenerative stages of IDD.

Remodeling tumor microenvironment with natural products to overcome drug resistance

With cancer incidence rates continuing to increase and occurrence of resistance in drug treatment, there is a pressing demand to find safer and more effective anticancer strategy for cancer patients. Natural products, have the advantage of low toxicity and multiple action targets, are always used in the treatment of cancer prevention in early stage and cancer supplement in late stage. Tumor microenvironment is necessary for cancer cells to survive and progression, and immune activation is a vital means for the tumor microenvironment to eliminate cancer cells. A number of studies have found that various natural products could target and regulate immune cells such as T cells, macrophages, mast cells as well as inflammatory cytokines in the tumor microenvironment. Natural products tuning the tumor microenvironment via various mechanisms to activate the immune response have immeasurable potential for cancer immunotherapy. In this review, it highlights the research findings related to natural products regulating immune responses against cancer, especially reveals the possibility of utilizing natural products to remodel the tumor microenvironment to overcome drug resistance.