Non-coding RNAs: An emerging player in particulate matter 2.5-mediated toxicity

Exposure to air pollution has been connected to around seven million early deaths annually and also contributing to higher than 3 % of disability-adjusted lost life years. Particulate matters (PM) are among the key pollutants that directly discharged or formed due to atmospheric chemical interactions. Among these matters, due of its large surface area, PM2.5 may absorb a different harmful and toxic substances. One of the outcomes of such environmental disturbance is oxidative stress which affects cellular processes including apoptosis, inflammation, and epithelial mesenchymal transition. Non-coding RNAs (ncRNA) such as, miRNAs, lncRNAs, and circRNAs are classified as non-protein coding RNA's. Over the past few years these small molecules have been gaining so much attention since they participate in variety of physiological and pathological processes and their expression change during disease periods. Regarding epigenetic properties, ncRNAs play an important function in organism's response to environmental stimulus. In this manner, it was revealed that exposure to PM2.5 may cause epigenetic reprogramming, such as, ncRNAs signature's alteration, which can be effective concerning pathophysiology state. In this review, we describe PM2.5 impact on ncRNAs and excavate its roles in toxicity caused by PM2.5.

Emerging evidence on noncoding-RNA regulatory machinery in intervertebral disc degeneration: a narrative review

Intervertebral disc degeneration (IDD) is the most common cause of low-back pain. Accumulating evidence indicates that the expression profiling of noncoding RNAs (ncRNAs), including microRNAs (miRNAs), circular RNAs (circRNAs), and long noncoding RNAs (lncRNAs), are different between intervertebral disc tissues obtained from healthy individuals and patients with IDD. However, the roles of ncRNAs in IDD are still unclear until now. In this review, we summarize the studies concerning ncRNA interactions and regulatory functions in IDD. Apoptosis, aberrant proliferation, extracellular matrix degradation, and inflammatory abnormality are tetrad fundamental pathologic phenotypes in IDD. We demonstrated that ncRNAs are playing vital roles in apoptosis, proliferation, ECM degeneration, and inflammation process of IDD. The ncRNAs participate in underlying mechanisms of IDD in different ways. MiRNAs downregulate target genes’ expression by directly binding to the 3′-untranslated region of mRNAs. CircRNAs and lncRNAs act as sponges or competing endogenous RNAs by competitively binding to miRNAs and regulating the expression of mRNAs. The lncRNAs, circRNAs, miRNAs, and mRNAs widely crosstalk and form complex regulatory networks in the degenerative processes. The current review presents novel insights into the pathogenesis of IDD and potentially sheds light on the therapeutics in the future.

Inflexibility of the plasma miRNA response following a high-carbohydrate meal in overweight insulin-resistant women

Context

Metabolic inflexibility is a characteristic of insulin resistance, limiting the ability to transiently regulate oxidative metabolism and gene expression in response to nutrient availability. Little is known of the flexibility of post-transcriptional regulation, including circulatory miRNAs (c-miRNAs).

Design

The abundances of targeted c-miRNAs, with reported functions in metabolic regulation, were analysed in response to a high-carbohydrate meal in healthy weight insulin-sensitive (IS) and overweight insulin-resistant (IR) women.

Participants

Age-matched healthy weight IS (n = 20, BMI = 24.3 ± 0.70) and overweight IR (n = 20, BMI = 28.6 ± 0.67) women.

Methods

An abundance of c-miRNAs was quantified prior to and following a high-carbohydrate breakfast meal (2500 kJ; 50% carbohydrate, 20% fat and 27% protein). Target genes of the differentially regulated c-miRNA were measured in RNA extracted from circulatory peripheral blood mononuclear cells (PBMCs).

Results

In healthy weight IS women, both miR-15a-5p (p = 0.03) and miR-17-5p (p < 0.01) levels were halved at 4 h post-meal. These miRNA remained unaltered following the same meal in the overweight IR women. Furthermore, amongst genes targeted by these miRNA, CPT1A (p = 0.01) and IL8 (p = 0.03) had also reduced expression 4 h post-meal only in the healthy weight IS women.

Conclusions

The study findings provide preliminary evidence for a possible extension of metabolic inflexibility to include c-miRNAs.

Trial registration

The clinical trial is registered with Australian New Zealand Clinical Trials Registry under Trial registration: ANZCTR: ACTRN12615001108505. Registered on 21 October 2015.