Egr2 and 3 control inflammation, but maintain homeostasis, of PD-1high memory phenotype CD4 T cells

BACH1 as a key driver in rheumatoid arthritis fibroblast-like synoviocytes identified through gene network analysis

RNA-sequencing and differential gene expression studies have significantly advanced our understanding of pathogenic pathways underlying rheumatoid arthritis (RA). Yet, little is known about cell-specific regulatory networks and their contributions to disease. In this study, we focused on fibroblast-like synoviocytes (FLS), a cell type central to disease pathogenesis and joint damage in RA. We used a strategy that computed sample-specific gene regulatory networks to compare network properties between RA and osteoarthritis FLS. We identified 28 transcription factors (TFs) as key regulators central to the signatures of RA FLS. Six of these TFs are new and have not been previously implicated in RA through ex vivo or in vivo studies, and included BACH1, HLX, and TGIF1. Several of these TFs were found to be co-regulated, and BACH1 emerged as the most significant TF and regulator. The main BACH1 targets included those implicated in fatty acid metabolism and ferroptosis. The discovery of BACH1 was validated in experiments with RA FLS. Knockdown of BACH1 in RA FLS significantly affected the gene expression signatures, reduced cell adhesion and mobility, interfered with the formation of thick actin fibers, and prevented the polarized formation of lamellipodia, all required for the RA destructive behavior of FLS. This study establishes BACH1 as a central regulator of RA FLS phenotypes and suggests its potential as a therapeutic target to selectively modulate RA FLS.

Protective effects of taurine on heat Stress-Induced cognitive impairment through Npas4 and Lcn2

Heat stress (HS) induces various pathophysiological responses in the brain, encompassing neuroinflammation and cognitive impairments. Although taurine has been reported to possess anti-inflammatory and cognitive-enhancing properties, its role and mechanisms in HS-induced cognitive impairment remain unclear. This study supplemented mice exposed to HS with taurine to assess its effect on cognitive function in a HS-induced mouse model. The results revealed that taurine ameliorated cognitive deficits following HS in mice and mitigated HS-induced astrocyte and microglia activation as well as blood-brain barrier (BBB) damage in the hippocampus. Mechanistically, Mechanistically, transcriptome sequencing was employed to identify that taurine regulates neuronal PAS domain protein (Npas4) and lipocalin 2 (Lcn2) during HS. Taurine was found to modulate hippocampal inflammation and influence cognitive function by upregulating Npas4 and downregulating Lcn2 after HS. Subsequently, molecular docking and AnimalTFDB database calculations were conducted, revealing that taurine might regulate the expression of Npas4 and Lcn2 by modulating the regulatory transcription factors (TFs) RE1 silencing transcription factor (REST) and nuclear factor of kappa light polypeptide gene enhancer in B-cells 1 (NFKB1). Our findings demonstrate that taurine enhances the recovery of cognitive function through Npas4 and Lcn2 following HS, providing a theoretical basis for the clinical application of taurine in preventing or treating HS-induced cognitive impairment.

Gene Network Analyses Identify Co-regulated Transcription Factors and BACH1 as a Key Driver in Rheumatoid Arthritis Fibroblast-like Synoviocytes

RNA-sequencing and differential gene expression studies have significantly advanced our understanding of pathogenic pathways underlying Rheumatoid Arthritis (RA). Yet, little is known about cell-specific regulatory networks and their contributions to disease. In this study, we focused on fibroblast-like synoviocytes (FLS), a cell type central to disease pathogenesis and joint damage in RA. We used a strategy that computed sample-specific gene regulatory networks (GRNs) to compare network properties between RA and osteoarthritis FLS. We identified 28 transcription factors (TFs) as key regulators central to the signatures of RA FLS. Six of these TFs are new and have not been previously implicated in RA, and included BACH1, HLX, and TGIF1. Several of these TFs were found to be co-regulated, and BACH1 emerged as the most significant TF and regulator. The main BACH1 targets included those implicated in fatty acid metabolism and ferroptosis. The discovery of BACH1 was validated in experiments with RA FLS. Knockdown of BACH1 in RA FLS significantly affected the gene expression signatures, reduced cell adhesion and mobility, interfered with the formation of thick actin fibers, and prevented the polarized formation of lamellipodia, all required for the RA destructive behavior of FLS. This is the first time that BACH1 is shown to have a central role in the regulation of FLS phenotypes, and gene expression signatures, as well as in ferroptosis and fatty acid metabolism. These new discoveries have the potential to become new targets for treatments aimed at selectively targeting the RA FLS.

Egr3 as an important regulator of uterine decidualization through targeting Hand2

Early growth response 3 (Egr3) is required for embryogenesis, but little understanding is usable about its function in embryo implantation and decidualization. The present study exhibited an obvious localization of Egr3 in luminal epithelium and subluminal stroma at implantation sites. Administration of estrogen brought about a distinct gather of Egr3 mRNA in uterine luminal and glandular epithelia. Meanwhile, Egr3 was visualized in the decidua where it might facilitate the proliferation of stromal cells via Ccnd3 and accelerate stromal differentiation, testifying the significance of Egr3 in decidualization. In ovariectomized mice uteri or stromal cells, progesterone advanced the expression of Egr3 whose obstruction counteracted the inducement of stromal differentiation by progesterone. Consistently, Egr3 mediated the influence of cAMP and heparin-binding EGF-like growth factor (HB-EGF) on the differentiation program. Additionally, cAMP-protein kinase A (PKA) signaling mediated the adjustment of progesterone on Egr3. Impediment of HB-EGF antagonized the ascendance of Egr3 conferred by cAMP. In stromal cells, Egr3 activated the transcription of Hand2 whose promoter region exhibited the binding enrichment of Egr3. Activation of Hand2 relieved the weakness of stromal differentiation by Egr3 hinderance, whereas knockdown of Hand2 neutralized the guidance of Egr3 overexpression on the differentiation program. Collectively, Egr3 was identified as an important regulator of uterine decidualization through targeting Hand2 in response to progesterone/cAMP/HB-EGF pathway.

iPSC-based model of Vogt-Koyanagi-Harada disease for phenotype recapitulation and drug screening

Vogt-Koyanagi-Harada (VKH) disease, a major blinding eye disease, is characterized by an autoimmune response against melanocytes in multiple organs throughout the body. Currently, the aetiology and pathogenesis of VKH disease are unclear, and the treatment strategy needs to be further optimized. The retinal pigment epithelium (RPE), a monolayer of pigmented cells of the fundus, is essential for maintaining normal visual function and is involved in both the acute and chronic stages of VKH disease. Therefore, the functions of the RPE may play a critical role in the aetiology and treatment of VKH disease. Herein, we established a human induced pluripotent stem cell (hiPSC) RPE model of VKH disease by reprogramming peripheral blood mononuclear cells (PBMCs) into iPSCs and then differentiating them into RPE cells. Patient-derived RPE cells exhibited barrier disruption, impaired phagocytosis, and depigmentation compared with those from normal controls, which was consistent with the features of VKH disease. Furthermore, a small molecular compound targeting EGR2 was found to rescue the barrier and phagocytic functions of the hiPSC-RPE cells through high-throughput virtual screening and functional studies, suggesting a promising strategy for the treatment of VKH disease.

Egr2 and 3 maintain anti-tumour responses of exhausted tumour infiltrating CD8 + T cells

Although T cells can develop into an exhausted state in the tumour microenvironment, tumour infiltrating T cells (TILs) are important to control tumour growth. By analysing single cell RNA-sequencing data from human tumours, we found that the transcription factors Early Growth Response 2 (EGR2) and 3 were highly induced in TILs, but not peripheral CD8 + T cells, in multiple patient cohorts. We found that deficiency of Egr2 and 3 in T cells resulted in enhanced tumour growth and fewer TILs in mouse models. Egr2 is highly expressed together with checkpoint molecules in a proportion of CD8 + TILs and Egr2high cells exhibit better survival and proliferation than Egr2-/-Egr3-/- and Egr2low TILs. Anti-PD-1 treatment increases Egr2 expression in CD8 + TILs and reduces tumour growth, while anti-PD-1 efficacy is abrogated in the absence of Egr2 and 3. Thus, Egr2 and 3 are important for maintaining anti-tumour responses of exhausted CD8 + TILs.

EGR2 is a hub-gene in myocardial infarction and aggravates inflammation and apoptosis in hypoxia-induced cardiomyocytes

Background

Myocardial infarction (MI) is characterized by coronary artery occlusion, ischemia and hypoxia of myocardial cells, leading to irreversible myocardial damage. Therefore, it is urgent to explore the potential mechanism of myocardial injury during the MI process to develop effective therapies for myocardial cell rescue.

Methods

We downloaded the GSE71906 dataset from GEO DataSets, and the R software was used to identify the differentially expressed genes (DEGs) in mouse heart tissues of MI and sham controls. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were performed to understand the significantly activated signaling pathways in MI. Protein–protein interaction (PPI) network was constructed to highlight the hub genes in DEGs. The Western Blot, qRT-PCR and TUNEL staining were used to explore the function of hub gene in hypoxia-induced cardiomyocytes in vitro.

Results

A total of 235 DEGs were identified in GSE71906 dataset. Functional enrichment analysis revealed that the upregulated genes were primarily associated with the inflammatory response and apoptosis. 20 hub genes were identified in PPI network, and the early growth response 2 (EGR2) was highlighted. In vitro. We confirmed the EGR2 was upregulated induced by hypoxia and revealed the upregulated EGR2 aggravates pro-inflammation and pro-apoptotic genes expression. In addition, EGR2 knockout mitigates hypoxia-induced inflammation and apoptosis in cardiomyocytes.

Conclusion

The present study identified the EGR2 was a hub gene in myocardial damage during MI process, the excessive EGR2 aggravates hypoxia-induced myocardial damage by accelerating inflammation and apoptosis in vitro. Therefore, targeting EGR2 offers a potential pharmacological strategy for myocardial cell rescue in MI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02814-3.

Small, Dense Low-Density Lipoprotein-Cholesterol and Atherosclerosis: Relationship and Therapeutic Strategies

Low-density lipoprotein cholesterol (LDL-C) plays an important role in the formation, incidence, and development of atherosclerosis (AS). Low-density lipoproteins can be divided into two categories: large and light LDL-C and small, dense low-density lipoprotein cholesterol (sdLDL-C). In recent years, an increasing number of studies have shown that sdLDL-C has a strong ability to cause AS because of its unique characteristics, such as having small-sized particles and low density. Therefore, this has become the focus of further research. However, the specific mechanisms regarding the involvement of sdLDL-C in AS have not been fully explained. This paper reviews the possible mechanisms of sdLDL-C in AS by reviewing relevant literature in recent years. It was found that sdLDL-C can increase the atherogenic effect by regulating the activity of gene networks, monocytes, and enzymes. This article also reviews the research progress on the effects of sdLDL-C on endothelial function, lipid metabolism, and inflammation; it also discusses its intervention effect. Diet, exercise, and other non-drug interventions can improve sdLDL-C levels. Further, drug interventions such as statins, fibrates, ezetimibe, and niacin have also been found to improve sdLDL-C levels.