The association of RAR-related orphan receptor A (RORA) gene polymorphisms with the risk of asthma

Characteristics of splenic PD-1+ γδT cells in Plasmodium yoelii nigeriensis infection

Although the functions of programmed death-1 (PD-1) on αβ T cells have been extensively reported, a role for PD-1 in regulating γδT cell function is only beginning to emerge. Here, we investigated the phenotypic and functional characteristics of PD-1-expressing γδT cells, and the molecular mechanism was also explored in the Plasmodium yoelii nigeriensis (P. yoelii NSM)-infected mice. Flow cytometry and single-cell RNA sequencing (scRNA-seq) were performed. An inverse agonist of RORα, SR3335, was used to investigate the role of RORα in regulating PD-1+ γδT cells. The results indicated that γδT cells continuously upregulated PD-1 expression during the infection period. Higher levels of CD94, IL-10, CX3CR1, and CD107a; and lower levels of CD25, CD69, and CD127 were found in PD-1+ γδT cells from infected mice than in PD-1- γδT cells. Furthermore, GO enrichment analysis revealed that the marker genes in PD-1+ γδT cells were involved in autophagy and processes utilizing autophagic mechanisms. ScRNA-seq results showed that RORα was increased significantly in PD-1+ γδT cells. GSEA identified that RORα was mainly involved in the regulation of I-kappaB kinase/NF-κB signaling and the positive regulation of cytokine production. Consistent with this, PD-1-expressing γδT cells upregulated RORα following Plasmodium yoelii infection. Additionally, in vitro studies revealed that higher levels of p-p65 were found in PD-1+ γδT cells after treatment with a RORα selective synthetic inhibitor. Collectively, these data suggest that RORα-mediated attenuation of NF-κB signaling may be fundamental for PD-1-expressing γδT cells to modulate host immune responses in the spleen of Plasmodium yoelii nigeriensis-infected C57BL/6 mice, and it requires further investigation.

Qishen Yiqi dropping pills improve cardiomyocyte hypertrophy via the lncRNA TINCR/miR-193b-3p/RORA axis

BACKGROUND

This study was designed to explore the therapeutic effect and mechanism of action of Qishen Yiqi dropping pills (QYDP) in chronic heart failure (CHF) via a long non-coding RNA (lncRNA)-microRNA (miRNA)-messenger RNA (mRNA) axis. Here, the mechanism of action of the lncRNA terminal differentiation-induced non-coding RNA (TINCR), miR-193b-3p, and RAR-related orphan receptor A (RORA) mRNA was analyzed in an angiotensin (Ang) II-induced H9C2 cardiomyocyte hypertrophy model treated with QYDP.

METHODS

Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to analyze the gene expression changes of lncRNA, miRNA, and mRNA in H9C2 induced by QYDP on Ang II. The Gene Expression Omnibus (GEO) was used to analyze differentially expressed genes (DEGs) potentially affecting CHF progression. Cell Counting Kit-8 (CCK-8) was used to analyze the effect of QYDP on the proliferation of H9C2, RNA pull-down was used to analyze the binding of lncRNA and miRNA, and dual luciferase was used to analyze the targeting of miRNA and lncRNA or mRNA.

RESULTS

Ang II induced TINCR and RORA downregulation, miR-193b-3p upregulation, and hypertrophy in the H9C2 cardiomyocytes, which were alleviated by QYDP. In contrast, TINCR inhibition reversed the effects of QYDP by increasing miR-193b-3p expression and downregulating RORA expression. According to subsequent double luciferase and RNA pull-down experiments, TINCR adsorbed miR-193b-3p by acting as a competitive endogenous RNA sponge and miR-193b-3p directly targeted RORA. Lastly, we showed that the Ang-II-induced inhibition of TINCR and RORA expression and promotion of cardiac hypertrophy were both reversed by a TINCR overexpression plasmid (ov-TINCR), whereas the effects of ov-TINCR were suppressed by a miR-193b-3p mimic.

CONCLUSIONS

Administration of QYDP improves Ang II-induced H9C2 cardiomyocyte hypertrophy and increase cell proliferation rate through the TINCR/miR-193b-3p/RORA axis.

Rora Regulates Neutrophil Migration and Activation in Zebrafish

Neutrophil migration and activation are essential for defense against pathogens. However, this process may also lead to collateral tissue injury. We used microRNA overexpression as a platform and discovered protein-coding genes that regulate neutrophil migration. Here we show that miR-99 decreased the chemotaxis of zebrafish neutrophils and human neutrophil-like cells. In zebrafish neutrophils, miR-99 directly targets the transcriptional factor RAR-related orphan receptor alpha (roraa). Inhibiting RORα, but not the closely related RORγ, reduced chemotaxis of zebrafish and primary human neutrophils without causing cell death, and increased susceptibility of zebrafish to bacterial infection. Expressing a dominant-negative form of Rorα or disrupting the roraa locus specifically in zebrafish neutrophils reduced cell migration. At the transcriptional level, RORα regulates transmembrane signaling receptor activity and protein phosphorylation pathways. Our results, therefore, reveal previously unknown functions of miR-99 and RORα in regulating neutrophil migration and anti-microbial defense.

RORA alleviates LPS-induced apoptosis of renal epithelial cells by promoting PGC-1α transcription

OBJECTIVE

To explore the effect of RORA on LPS-induced renal epithelial cell apoptosis and the underlying mechanism.

METHODS

LPS-treated HK-2 cells were established as a cellular model of acute kidney injury. The expression of RORA or/and PGC-1α in LPS-induced HK-2 cells was altered by transfection. qRT-PCR and Western blotting were used to detect the expression changes of RORA and PGC-1α. ELISA was performed to detect the expression of IL-1β and IL-6 and the activity of caspase-3. Western blotting was applied for visualization of cleaved caspase-3. CCK-8 and flow cytometry were used to assess cell proliferation and apoptosis. Dual-luciferase reporter and ChIP-qPCR were utilized to verify the binding of RORA to PGC-1α promoter.

RESULTS

LPS treatment decreased the expression of RORA and PGC-1α and increased that of cleaved caspase-3 in HK-2 cells. Also, LPS treatment inhibited HK-2 cell proliferation and promoted HK-2 cell apoptosis and secretion of IL-1β and IL-6. Overexpression of RORA or PGC-1α eliminated the adverse effects of LPS treatment in HK-2 cells. RORA drove the transcription of PGC-1α by binding PGC-1α promoter. Knockdown of PGC-1α offset the reduction in HK-2 cell injury caused by overexpression of RORA.

CONCLUSION

RORA reduces LPS-induced apoptosis of renal epithelial cells by promoting PGC-1α transcription.

Nuclear Receptors in Asthma: Empowering Classical Molecules Against a Contemporary Ailment

The escalation in living standards and adoption of 'Western lifestyle' has an allied effect on the increased allergy and asthma burden in both developed and developing countries. Current scientific reports bespeak an association between allergic diseases and metabolic dysfunction; hinting toward the critical requirement of organized lifestyle and dietary habits. The ubiquitous nuclear receptors (NRs) translate metabolic stimuli into gene regulatory signals, integrating diet inflences to overall developmental and physiological processes. As a consequence of such promising attributes, nuclear receptors have historically been at the cutting edge of pharmacy world. This review discusses the recent findings that feature the cardinal importance of nuclear receptors and how they can be instrumental in modulating current asthma pharmacology. Further, it highlights a possible future employment of therapy involving dietary supplements and synthetic ligands that would engage NRs and aid in eliminating both asthma and linked comorbidities. Therefore, uncovering new and evolving roles through analysis of genomic changes would represent a feasible approach in both prevention and alleviation of asthma.