Maternally expressed gene 3 in metabolic programming

Variable expression of MECP2, CDKL5, and FMR1 in the human brain: Implications for gene restorative therapies

MECP2, CDKL5, and FMR1 are three X-linked neurodevelopmental genes associated with Rett, CDKL5-, and fragile-X syndrome, respectively. These syndromes are characterized by distinct constellations of severe cognitive and neurobehavioral anomalies, reflecting the broad but unique expression patterns of each of the genes in the brain. As these disorders are not thought to be neurodegenerative and may be reversible, a major goal has been to restore expression of the functional proteins in the patient's brain. Strategies have included gene therapy, gene editing, and selective Xi-reactivation methodologies. However, tissue penetration and overall delivery to various regions of the brain remain challenging for each strategy. Thus, gaining insights into how much restoration would be required and what regions/cell types in the brain must be targeted for meaningful physiological improvement would be valuable. As a step toward addressing these questions, here we perform a meta-analysis of single-cell transcriptomics data from the human brain across multiple developmental stages, in various brain regions, and in multiple donors. We observe a substantial degree of expression variability for MECP2, CDKL5, and FMR1 not only across cell types but also between donors. The wide range of expression may help define a therapeutic window, with the low end delineating a minimum level required to restore physiological function and the high end informing toxicology margin. Finally, the inter-cellular and inter-individual variability enable identification of co-varying genes and will facilitate future identification of biomarkers.

The expression and function of long noncoding RNAs in hepatocellular carcinoma

With the deepening of the genome project study, attention on noncoding RNAs is increasing. Long noncoding RNAs (lncRNAs) have become a new research hotspot. A growing number of studies have revealed that lncRNAs are involved in tumorigenesis and tumor suppressor pathways. Aberrant expressions of lncRNAs have been found in a variety of human tumors including hepatocellular carcinoma (HCC). In this review, we provide a brief introduction to lncRNA and highlight recent research on the functions and clinical significance of lncRNAs in HCC.

Prolonged fasting times reap greater geroprotective effects when combined with caloric restriction in adult female mice

Emerging new evidence highlights the importance of prolonged daily fasting periods for the health and survival benefits of calorie restriction (CR) and time-restricted feeding (TRF) in male mice; however, little is known about the impact of these feeding regimens in females. We placed 14-month-old female mice on five different dietary regimens, either CR or TRF with different feeding windows, and determined the effects of these regimens on physiological responses, progression of neoplasms and inflammatory diseases, serum metabolite levels, and lifespan. Compared with TRF feeding, CR elicited a robust systemic response, as it relates to energetics and healthspan metrics, a unique serum metabolomics signature in overnight fasted animals, and was associated with an increase in lifespan. These results indicate that daytime (rest-phase) feeding with prolonged fasting periods initiated late in life confer greater benefits when combined with imposed lower energy intake.

LncRNA MEG3 inhibits renal fibrinoid necrosis of diabetic nephropathy via the MEG3/miR-21/ORAI1 axis

INTRODUCTION

Diabetic nephropathy (DN) is one of the most common and lethal diabetic complications worldwide and is associated with a high risk of mortality. However, the exact mechanism behind its development is unknown. The mesangial cells (MCs) and non-coding RNAs are critical for DN, but it is unknown whether a MEG3/miR-21/ORAI1 regulatory axis exists in MCs. Hence, in this study, we aimed to understand whether the MEG3/miR-21/ORAI1 regulatory axis has a role in the pathophysiology of DN.

RESULTS

We demonstrated that high-glucose stimuli downregulated MEG3 and ORAI1 expression while enhancing miR-21 expression. Exogenous miR-21 mimics inhibited ORAI1 expression, which was partially salvaged or reversed by MEG3 overexpression. Furthermore, RIP assay demonstrated that the beads labeled with AGO2 antibody could enrich more miR-21 and MEG3 than those labeled with control IgG antibody; both of them formed the RNA-induced silencing complex. Further, the biochemical indicators of db/db mice significantly improved, and renal fibrinoid necrosis was ameliorated using a miR-21 inhibitor.

CONCLUSION

The MEG3/miR-21/ORAI1 axis regulates the manifestation of DN in diabetic mice and MCs, and the miR-21 inhibitor can be a potential therapeutic strategy to alleviate DN, once the presence of such an axis is found in humans.

Augmented Production of Platelets From Cord Blood With Euchromatic Histone Lysine Methyltransferase Inhibition

Cord blood hematopoietic stem/progenitor cells (CB-HSPCs) have emerged as a promising supply for functional platelets to potentially alleviate the increasing demand for platelet transfusions, but the clinical application has been limited by the undefined molecular mechanism and insufficient platelet production. Here, we performed single-cell profiling of more than 16 160 cells to construct a dynamic molecular landscape of human megakaryopoiesis from CB-HSPCs, enabling us to uncover, for the first time, cellular heterogeneity and unique features of neonatal megakaryocytes (MKs) and to also offer unique resources for the scientific community. By using this model, we defined the genetic programs underlying the differentiation process from megakaryocyte-erythroid progenitors (MEPs) to MKs via megakaryocyte progenitors (MKPs) and identified inhibitors of euchromatic histone lysine methyltransferase (EHMT), which, when applied at the early stage of differentiation, significantly increase the final platelet production. At the mechanistic level, we found that EHMT inhibitors act to selectively induce the expansion of MEPs and MKPs. Together, we uncover new mechanistic insights into human megakaryopoiesis and provide a novel chemical strategy for future large-scale generation and clinical applications of platelets.

Long non-coding RNA MEG3 promotes autophagy and apoptosis of nasopharyngeal carcinoma cells via PTEN up-regulation by binding to microRNA-21

Long non-coding RNAs (lncRNAs) have been highlighted as attractive markers for diagnosis and prognosis as well as new therapeutic targets in multiple cancers, including nasopharyngeal carcinoma (NPC). Here, we attempted to investigate the underlying regulatory role of the lncRNA maternally expressed gene 3 (MEG3) in NPC development. As determined by RT-qPCR, MEG3 expression was down-regulated in NPC cells. Online RNA crosstalk analysis predicted the binding of miR-21 to MEG3 and PTEN, respectively. MEG3 was validated to bind to miR-21 while PTEN was identified as a target of miR-21 by dual-luciferase reporter gene assay. Exogenous transfection was done to change the levels of MEG3, miR-21 and PTEN in HK-1 cells to investigate their effects on the autophagy and apoptosis of NPC cells. The results suggested that MEG3 overexpression in HK-1 cells up-regulated PTEN and down-regulated miR-21, by which MEG3 further inhibited autophagy and apoptosis ability of NPC cells. The tumour formation ability was tested after injecting the HK-1 cells into nude, mice and tumour growth was monitored. Consistently, MEG3 overexpression inhibited the tumour formation in vivo. Collectively, MEG3 promotes the autophagy and apoptosis of NPC cells via enhancing PTEN expression by binding to miR-21.

Long Non-Coding RNAs in Liver Cancer and Nonalcoholic Steatohepatitis

This review aims to highlight the recent findings of long non-coding RNAs (lncRNAs) in liver disease. In particular, we focus on the functions of lncRNAs in hepatocellular carcinoma (HCC) and non-alcoholic steatohepatitis (NASH). We summarize the current research trend in lncRNAs and their potential as biomarkers and therapeutic targets for the treatment of HCC and NASH.

Maternally-Expressed Gene 3 (MEG3)/miR-143-3p Regulates Injury to Periodontal Ligament Cells by Mediating the AKT/Inhibitory κB Kinase (IKK) Pathway

Background

Dysregulated long noncoding RNAs (lncRNAs) are implicated in periodontitis development. Nevertheless, the role and mechanism of lncRNA maternally-expressed gene 3 (MEG3) in periodontitis progression remain unclear. This study aimed to explore how and whether MEG3 affect viability, apoptosis, and inflammatory response in lipopolysaccharide (LPS)-treated periodontal ligament cells (PDLCs).

Material/Methods

Periodontal ligament tissues were collected from periodontitis patients or normal individuals. PDLCs were obtained from normal periodontal ligament and treated with lipopolysaccharide (LPS). LPS-induced PDLCs injury was assessed via viability, apoptosis and inflammatory response using Cell Counting Kit-8, flow cytometry, quantitative reverse transcription polymerase chain reaction, enzyme-linked immunosorbent assay, and Western blot. The levels of MEG3 and microRNA (miR)-143-3p were examined via quantitative reverse transcription polymerase chain reaction. The protein kinase B(AKT)/inhibitory κB kinase (IKK) pathway was analyzed via Western blot. The target correlation of MEG3 and miR-143-3p was determined through dual-luciferase reporter analysis.

Results

MEG3 level was decreased and miR-143-3p level was upregulated in periodontitis and LPS-treated PDLCs. MEG3 overexpression or miR-143-3p knockdown alleviated LPS-induced viability inhibition, apoptosis promotion, and inflammatory response. MEG3 was a sponge for miR-143-3p. miR-143-3p overexpression weakened the effect of MEG3 on LPS-induced injury. MEG3 overexpression inhibited the activation of AKT/IKK pathway by sponging miR-143-3p in LPS-treated PDLCs.

Conclusions

MEG3 overexpression inhibited LPS-induced injury in PDLCs by inactivating the AKT/IKK pathway via sponging miR-143-3p, providing a potential target for treatment of periodontitis.