Control (Native) and oxidized (DeMP) mitochondrial RNA are proinflammatory regulators in human

Identifying Candidate Circulating RNA Markers for Coronary Artery Disease by Deep RNA-Sequencing in Human Plasma

Advances in RNA sequencing (RNA-Seq) have facilitated transcriptomic analysis of plasma for the discovery of new diagnostic and prognostic markers for disease. We aimed to develop a short-read RNA-Seq protocol to detect mRNAs, long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) in plasma for the discovery of novel markers for coronary artery disease (CAD) and heart failure (HF). Circulating cell-free RNA from 59 patients with stable CAD (half of whom developed HF within 3 years) and 30 controls was sequenced to a median depth of 108 paired reads per sample. We identified fragments from 3986 messenger RNAs (mRNAs), 164 long non-coding RNAs (lncRNAs), 405 putative novel lncRNAs and 227 circular RNAs in plasma. Circulating levels of 160 mRNAs, 10 lncRNAs and 2 putative novel lncRNAs were altered in patients compared with controls (absolute fold change >1.2, p < 0.01 adjusted for multiple comparisons). The most differentially abundant transcripts were enriched in mRNAs encoded by the mitochondrial genome. We did not detect any differences in the plasma RNA profile between patients who developed HF compared with those who did not. In summary, we show that mRNAs, lncRNAs and circular RNAs can be reliably detected in plasma by deep RNA-Seq. Multiple coding and non-coding transcripts were altered in association with CAD, including several mitochondrial mRNAs, which may indicate underlying myocardial ischaemia and oxidative stress. If validated, circulating levels of these transcripts could potentially be used to help identify asymptomatic individuals with established CAD prior to an acute coronary event.

Oxidative Modifications of RNA and Its Potential Roles in Biosystem

Elevated level of oxidized RNA was detected in vulnerable neurons in Alzheimer patients. Subsequently, several diseases and pathological conditions were reported to be associated with RNA oxidation. In addition to several oxidized derivatives, cross-linking and unique strand breaks are generated by RNA oxidation. With a premise that dysfunctional RNA mediated by oxidation is the pathogenetic molecular mechanism, intensive investigations have revealed the mechanism for translation errors, including premature termination, which gives rise to aberrant polypeptides. To this end, we and others revealed that mRNA oxidation could compromise its translational activity and fidelity. Under certain conditions, oxidized RNA can also induce several signaling pathways, to mediate inflammatory response and induce apoptosis. In this review, we focus on the oxidative modification of RNA and its resulting effect on protein synthesis as well as cell signaling. In addition, we will also discuss the potential roles of enzymatic oxidative modification of RNA in mediating cellular effects.

The existence and function of mitochondrial component in extracellular vesicles

Intercellular transfer of mitochondria and mitochondrial components through extracellular vesicles (EVs), including microvesicles and exosomes, is an area of intense interest. The cargos that are carried by EVs define their biological activities. Mitochondria are in charge of bioenergetics and maintenance of cell viability. Increasing evidences indicate the presence of intact mitochondria or mitochondrial components in EVs, which raises many questions, how they are engulfed into EVs and what do they do? Here, we present what is currently known about the presence and function of various mitochondrial constituent in EVs. We also review current understanding about how and why mitochondrial components are encapsulated into EVs.

Carotenoid metabolism in mitochondrial function

Mitochondria are highly dynamic organelles that are found in most eukaryotic organisms. It is broadly accepted that mitochondria originally evolved from prokaryotic bacteria, e.g. proteobacteria. The mitochondrion has its independent genome that encodes 37 genes, including 13 genes for oxidative phosphorylation. Accumulative evidence demonstrates that mitochondria are not only the powerhouse of the cells by supplying adenosine triphosphate, but also exert roles as signalling organelles in the cell fate and function. Numerous factors can affect mitochondria structurally and functionally. Carotenoids are a large group of fat-soluble pigments commonly found in our diets. Recently, much attention has been paid in carotenoids as dietary bioactives in mitochondrial structure and function in human health and disease, though the mechanistic research is limited. Here, we update the recent progress in mitochondrial functioning as signalling organelles in human health and disease, summarize the potential roles of carotenoids in regulation of mitochondrial redox homeostasis, biogenesis, and mitophagy, and discuss the possible approaches for future research in carotenoid regulation of mitochondrial function.

Lower concentrations of curcumin inhibit Her2-Akt pathway components in human breast cancer cells, and other dietary botanicals potentiate this and lapatinib inhibition

Her2-dependent breast cancer is treated with pharmacological drugs (eg, Herceptin, lapatinib) that target Her2 signaling. Curcumin has emerged as a potential co-treatment for this and other cancers, but prior studies have focused on non-attainable concentrations. Here we test the hypothesis that attainable in vivo levels of dietary curcumin can reduce Her2 signaling. Consistent with previous studies, higher dose curcumin (18 μmol/L) inhibits Her2-Akt pathway signaling (pHer2, total Her2 and pAkt levels) and cell growth using AU565 human breast cancer cells. We then examined lower, more physiologically relevant concentrations of curcumin, alone and in combination with other dietary botanicals (quercetin and OptiBerry fruit extract). At 4 μmol/L, curcumin reduced Her2 signaling, and even more when combined with quercetin or OptiBerry. At 1.5 μmol/L curcumin, pHer2 and Her2 (but not pAkt) were reduced, with all three pathway markers reduced more in the presence of quercetin. We also found that 1.5 μmol/L curcumin strongly potentiated lapatinib inhibition of Her2-Akt pathway signaling, and more so for pAkt, when combined with quercetin plus OptiBerry (CQO). Parallel analyses revealed cell growth inhibition at 18 and 4 μmol/L but not 1.5 μmol/L curcumin, and potentiation of 1.5 μmol/L curcumin growth arrest with other botanicals +/- lapatinib. These studies demonstrate that a physiological attainable level of curcumin (1.5 μmol/L) can reduce some components of the critical Her2-Akt pathway; that even more complete inhibition can be achieved by combination with other dietary botanicals; and that curcumin and other botanicals can potentiate the action of the Her2-cancer metastatic drug lapatinib, in turn suggesting the potential anti-cancer clinical use of these botanicals.