MicroRNA in cardiometabolic health and disease: The perspectives of sex, gender and personalised medicine

BACKGROUND

Personalized medicine represents a novel and integrative approach that focuses on an individual's genetics and epigenetics, precision medicine, lifestyle and exposures as key players of health status and disease phenotypes.

METHODS

In this narrative review, we aim to carefully discuss the current knowledge on gender disparities in cardiometabolic diseases, and we consider the sex- specific expression of miRNAs and their role as promising tool in precision medicine.

RESULTS

Personalised medicine overcomes the restricted care of patient based on a binomial sex approach, by enriching itself with a holistic and dynamic gender integration. Recognized as a major worldwide health emergency, cardiometabolic disorders continue to rise, impacting on health systems and requiring more effective and targeted strategies. Several sex and gender drivers might affect the onset and progression of cardiometabolic disorders in males and females at multiple levels. In this respect, distinct contribution of genetic and epigenetic mechanisms, molecular and physiological pathways, sex hormones, visceral fat and subcutaneous fat and lifestyle lead to differences in disease burden and outcomes in males and females.

CONCLUSIONS

Sex and gender play a pivotal role in precision medicine because the influence the physiology of each individual and the way they interact with environment from intrauterine life.

Non-Coding RNAs Regulate Spinal Cord Injury-Related Neuropathic Pain via Neuroinflammation

Secondary chronic neuropathic pain (NP) in addition to sensory, motor, or autonomic dysfunction can significantly reduce quality of life after spinal cord injury (SCI). The mechanisms of SCI-related NP have been studied in clinical trials and with the use of experimental models. However, in developing new treatment strategies for SCI patients, NP poses new challenges. The inflammatory response following SCI promotes the development of NP. Previous studies suggest that reducing neuroinflammation following SCI can improve NP-related behaviors. Intensive studies of the roles of non-coding RNAs in SCI have discovered that ncRNAs bind target mRNA, act between activated glia, neuronal cells, or other immunocytes, regulate gene expression, inhibit inflammation, and influence the prognosis of NP.

N6-methyladenosine and RNA secondary structure affect transcript stability and protein abundance during systemic salt stress in Arabidopsis

After transcription, a messenger RNA (mRNA) is further post-transcriptionally regulated by several features including RNA secondary structure and covalent RNA modifications (specifically N6-methyladenosine, m6A). Both RNA secondary structure and m6A have been demonstrated to regulate mRNA stability and translation and have been independently linked to plant responses to soil salinity levels. However, the effect of m6A on regulating RNA secondary structure and the combinatorial interplay between these two RNA features during salt stress response has yet to be studied. Here, we globally identify RNA-protein interactions and RNA secondary structure during systemic salt stress. This analysis reveals that RNA secondary structure changes significantly during salt stress, and that it is independent of global changes in RNA-protein interactions. Conversely, we find that m6A is anti-correlated with RNA secondary structure in a condition-dependent manner, with salt-specific m6A correlated with a decrease in mRNA secondary structure during salt stress. Taken together, we suggest that salt-specific m6A deposition and the associated loss of RNA secondary structure results in increases in mRNA stability for transcripts encoding abiotic stress response proteins and ultimately increases in protein levels from these stabilized transcripts. In total, our comprehensive analyses reveal important post-transcriptional regulatory mechanisms involved in plant long-term salt stress response and adaptation.

Concerted regulation of mitochondrial and nuclear non-coding RNAs by a dual-targeted RNase Z

The molecular roles of the dually targeted ElaC domain protein 2 (ELAC2) during nuclear and mitochondrial RNA processing in vivo have not been distinguished. We generated conditional knockout mice of ELAC2 to identify that it is essential for life and its activity is non-redundant. Heart and skeletal muscle-specific loss of ELAC2 causes dilated cardiomyopathy and premature death at 4 weeks. Transcriptome-wide analyses of total RNAs, small RNAs, mitochondrial RNAs, and miRNAs identified the molecular targets of ELAC2 in vivo We show that ELAC2 is required for processing of tRNAs and for the balanced maintenance of C/D box snoRNAs, miRNAs, and a new class of tRNA fragments. We identify that correct biogenesis of regulatory non-coding RNAs is essential for both cytoplasmic and mitochondrial protein synthesis and the assembly of mitochondrial ribosomes and cytoplasmic polysomes. We show that nuclear tRNA processing is required for the balanced production of snoRNAs and miRNAs for gene expression and that 3' tRNA processing is an essential step in the production of all mature mitochondrial RNAs and the majority of nuclear tRNAs.

miR-10b expression in breast cancer stem cells supports self-renewal through negative PTEN regulation and sustained AKT activation

Cancer stem cells (CSCs) are linked to metastasis. Moreover, a discrete group of miRNAs (metastamiRs) has been shown to promote metastasis. Accordingly, we propose that miRNAs that function as metastatic promoters may influence the CSC phenotype. To study this issue, we compared the expression of 353 miRNAs in CSCs enriched from breast cancer cell lines using qRT-PCR analysis. One of the most altered miRNAs was miR-10b, which is a reported promoter of metastasis and migration. Stable overexpression of miR-10b in MCF-7 cells (miR-10b-OE cells) promoted higher self-renewal and expression of stemness and epithelial-mesenchymal transition (EMT) markers. In agreement with these results, inhibiting miR-10b expression using synthetic antisense RNAs resulted in a decrease in CSCs self-renewal. Bioinformatics analyses identified several potential miR-10b mRNA targets, including phosphatase and tensin homolog (PTEN), a key regulator of the PI3K/AKT pathway involved in metastasis, cell survival, and self-renewal. The targeting of PTEN by miR-10b was confirmed using a luciferase reporter, qRT-PCR, and Western blot analyses. Lower PTEN levels were observed in CSCs, and miR-10b depletion not only increased PTEN mRNA and protein expression but also decreased the activity of AKT, a downstream PTEN target kinase. Correspondingly, PTEN knockdown increased stem cell markers, whereas AKT inhibitors compromised the self-renewal ability of CSCs and breast cancer cell lines overexpressing miR-10b. In conclusion, miR-10b regulates the self-renewal of the breast CSC phenotype by inhibiting PTEN and maintaining AKT pathway activation.

Defining a minimal cell: essentiality of small ORFs and ncRNAs in a genome-reduced bacterium

Identifying all essential genomic components is critical for the assembly of minimal artificial life. In the genome-reduced bacterium Mycoplasma pneumoniae, we found that small ORFs (smORFs; < 100 residues), accounting for 10% of all ORFs, are the most frequently essential genomic components (53%), followed by conventional ORFs (49%). Essentiality of smORFs may be explained by their function as members of protein and/or DNA/RNA complexes. In larger proteins, essentiality applied to individual domains and not entire proteins, a notion we could confirm by expression of truncated domains. The fraction of essential non-coding RNAs (ncRNAs) non-overlapping with essential genes is 5% higher than of non-transcribed regions (0.9%), pointing to the important functions of the former. We found that the minimal essential genome is comprised of 33% (269,410 bp) of the M. pneumoniae genome. Our data highlight an unexpected hidden layer of smORFs with essential functions, as well as non-coding regions, thus changing the focus when aiming to define the minimal essential genome.