MiR-155-Mediated Deregulation of GPER1 Plays an Important Role in the Gender Differences Related to Inflammatory Bowel Disease

MicroRNAs in inflammatory bowel disease: What do we know and what can we expect?

MicroRNAs (miRNAs), small non-coding RNAs composed of 18-24 nucleotides, are potent regulators of gene expression, contributing to the regulation of more than 30% of protein-coding genes. Considering that miRNAs are regulators of inflammatory pathways and the differentiation of intestinal epithelial cells, there is an interest in exploring their importance in inflammatory bowel disease (IBD). IBD is a chronic and multifactorial disease of the gastrointestinal tract; the main forms are Crohn's disease and ulcerative colitis. Several studies have investigated the dysregulated expression of miRNAs in IBD, demonstrating their important roles as regulators and potential biomarkers of this disease. This editorial presents what is known and what is expected regarding miRNAs in IBD. Although the important regulatory roles of miRNAs in IBD are clearly established, biomarkers for IBD that can be applied in clinical practice are lacking, emphasizing the importance of further studies. Discoveries regarding the influence of miRNAs on the inflammatory process and the exploration of their role in gene regulation are expected to provide a basis for the use of miRNAs not only as potent biomarkers in IBD but also as therapeutic targets for the control of inflammatory processes in personalized medicine.

Therapeutic potential of RNA-enriched extracellular vesicles: The next generation in RNA delivery via biogenic nanoparticles

Exosomes are extracellular vesicles (EVs) (∼50-150 nm) that have emerged as promising vehicles for therapeutic applications and drug delivery. These membrane-bound particles, released by all actively dividing cells, have the ability to transfer effector molecules, including proteins, RNA, and even DNA, from donor cells to recipient cells, thereby modulating cellular responses. RNA-based therapeutics, including microRNAs, messenger RNAs, long non-coding RNAs, and circular RNAs, hold great potential in controlling gene expression and treating a spectrum of medical conditions. RNAs encapsulated in EVs are protected from extracellular degradation, making them attractive for therapeutic applications. Understanding the intricate biology of cargo loading and transfer within EVs is pivotal to unlocking their therapeutic potential. This review discusses the biogenesis and classification of EVs, methods for loading RNA into EVs, their advantages as drug carriers over synthetic-lipid-based systems, and the potential applications in treating neurodegenerative diseases, cancer, and viral infections. Notably, EVs show promise in delivering RNA cargo across the blood-brain barrier and targeting tumor cells, offering a safe and effective approach to RNA-based therapy in these contexts.

The G protein-coupled oestrogen receptor GPER in health and disease: an update

Oestrogens and their receptors contribute broadly to physiology and diseases. In premenopausal women, endogenous oestrogens protect against cardiovascular, metabolic and neurological diseases and are involved in hormone-sensitive cancers such as breast cancer. Oestrogens and oestrogen mimetics mediate their effects via the cytosolic and nuclear receptors oestrogen receptor-α (ERα) and oestrogen receptor-β (ERβ) and membrane subpopulations as well as the 7-transmembrane G protein-coupled oestrogen receptor (GPER). GPER, which dates back more than 450 million years in evolution, mediates both rapid signalling and transcriptional regulation. Oestrogen mimetics (such as phytooestrogens and xenooestrogens including endocrine disruptors) and licensed drugs such as selective oestrogen receptor modulators (SERMs) and downregulators (SERDs) also modulate oestrogen receptor activity in both health and disease. Following up on our previous Review of 2011, we herein summarize the progress made in the field of GPER research over the past decade. We will review molecular, cellular and pharmacological aspects of GPER signalling and function, its contribution to physiology, health and disease, and the potential of GPER to serve as a therapeutic target and prognostic indicator of numerous diseases. We also discuss the first clinical trial evaluating a GPER-selective drug and the opportunity of repurposing licensed drugs for the targeting of GPER in clinical medicine.

ERα36-GPER1 Collaboration Inhibits TLR4/NFκB-Induced Pro-Inflammatory Activity in Breast Cancer Cells

Inflammation is important for the initiation and progression of breast cancer. We have previously reported that in monocytes, estrogen regulates TLR4/NFκB-mediated inflammation via the interaction of the Erα isoform ERα36 with GPER1. We therefore investigated whether a similar mechanism is present in breast cancer epithelial cells, and the effect of ERα36 expression on the classic 66 kD ERα isoform (ERα66) functions. We report that estrogen inhibits LPS-induced NFκB activity and the expression of downstream molecules TNFα and IL-6. In the absence of ERα66, ERα36 and GPER1 are both indispensable for this effect. In the presence of ERα66, ERα36 or GPER1 knock-down partially inhibits NFκB-mediated inflammation. In both cases, ERα36 overexpression enhances the inhibitory effect of estrogen on inflammation. We also verify that ERα36 and GPER1 physically interact, especially after LPS treatment, and that GPER1 interacts directly with NFκB. When both ERα66 and ERα36 are expressed, the latter acts as an inhibitor of ERα66 via its binding to estrogen response elements. We also report that the activation of ERα36 leads to the inhibition of breast cancer cell proliferation. Our data support that ERα36 is an inhibitory estrogen receptor that, in collaboration with GPER1, inhibits NFκB-mediated inflammation and ERα66 actions in breast cancer cells.

Effects of Huangqin Decoction on ulcerative colitis by targeting estrogen receptor alpha and ameliorating endothelial dysfunction based on system pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Huangqin Decoction (HQD), a traditional Chinese medicinal (TCM) formula chronicled in Shang Han Lun, has been used to treat gastrointestinal diseases for nearly 1800 years.

OBJECTIVE

To investigate the effects and underlying mechanisms of HQD on ulcerative colitis (UC).

METHODS

The bioactive compounds in HQD were obtained from the traditional Chinese medicine systems pharmacology database. Then, the HQD and UC-related targets were analyzed by establishing HQD-Compounds-Targets (H-C-T) and protein-protein interaction (PPI) networks. Enrichment analysis was used for further study. The candidate targets for the effects of HQD on UC were validated using a dextran sulfate sodium-induced UC mouse experiment.

RESULTS

The results showed that 51 key targets were gained by matching 284 HQD-related targets and 837 UC-related targets. Combined with H-C-T and PPI network analyses, the key targets were divided into endothelial growth, inflammation and signal transcription-related targets. Further experimental validation showed that HQD targeted estrogen receptor alpha (ESR1) and endothelial growth factor receptors to relieve endothelial dysfunction, thereby improving intestinal barrier function. The expression of inflammatory cytokines and signal transducers was suppressed by HQD treatment and inflammation was inhibited.

CONCLUSIONS

HQD may acts on UC via the regulation of targets and pathways related to improving the intestinal mucosal barrier and ameliorating endothelial dysfunction. Additionally, ERS1 may be a new target to explore the mechanisms of UC.