Influence of sex differences on microRNA gene regulation in disease

Specific circulating miRNAs are associated with plasma lipids in a healthy American cohort

Low-density lipoprotein cholesterol (LDL-c) is both a therapeutic target and a risk factor for cardiovascular disease (CVD). MicroRNA (miRNA) has been shown to regulate cholesterol homeostasis, and miRNA in blood circulation has been linked to hypercholesterolemia. However, few studies to date have associated miRNA with phenotypes like LDL-c in a healthy population. To this end, we analyzed circulating miRNA in relation to LDL-c in a healthy cohort of 353 participants using two separate bioinformatic approaches. The first approach found that miR-15b-5p and miR-16-5p were upregulated in individuals with at-risk levels of LDL-c. The second approach identified two miRNA clusters, one that positively and a second that negatively correlated with LDL-c. Included in the cluster that positively correlated with LDL-c were miR-15b-5p and miR-16-5p, as well as other miRNA from the miR-15/107, miR-30, and let-7 families. Cross-species analyses suggested that several miRNAs that associated with LDL-c are conserved between mice and humans. Finally, we examined the influence of diet on circulating miRNA. Our results robustly linked circulating miRNA with LDL-c, suggesting that miRNA could be used as biomarkers for hypercholesterolemia or targets for developing cholesterol-lowering drugs.NEW & NOTEWORTHY This study explored the association between circulating microRNA (miRNA) and low-density lipoprotein cholesterol (LDL-c) in a healthy population of 353 participants. Two miRNAs, miR-15b-5p and miR-16-5p, were upregulated in individuals with at-risk LDL-c levels. Several miRNA clusters were positively and negatively correlated with LDL-c and are known to target mRNA involved in lipid metabolism. The study also investigated the influence of diet on circulating miRNA, suggesting potential biomarkers for hypercholesterolemia.

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.

Identification of circulating miRNAs as fracture-related biomarkers

Fracture non-unions affect many patients worldwide, however, known risk factors alone do not predict individual risk. The identification of novel biomarkers is crucial for early diagnosis and timely patient treatment. This study focused on the identification of microRNA (miRNA) related to the process of fracture healing. Serum of fracture patients and healthy volunteers was screened by RNA sequencing to identify differentially expressed miRNA at various times after injury. The results were correlated to miRNA in the conditioned medium of human bone marrow mesenchymal stromal cells (BMSCs) during in vitro osteogenic differentiation. hsa-miR-1246, hsa-miR-335-5p, and miR-193a-5p were identified both in vitro and in fracture patients and their functional role in direct BMSC osteogenic differentiation was assessed. The results showed no influence of the downregulation of the three miRNAs during in vitro osteogenesis. However, miR-1246 may be involved in cell proliferation and recruitment of progenitor cells. Further studies should be performed to assess the role of these miRNA in other processes relevant to fracture healing.

Circulating MicroRNA as Biomarkers of Anthracycline-Induced Cardiotoxicity: JACC: CardioOncology State-of-the-Art Review

Close monitoring for cardiotoxicity during anthracycline chemotherapy is crucial for early diagnosis and therapy guidance. Currently, monitoring relies on cardiac imaging and serial measurement of cardiac biomarkers like cardiac troponin and natriuretic peptides. However, these conventional biomarkers are nonspecific indicators of cardiac damage. Exploring new, more specific biomarkers with a clear link to the underlying pathomechanism of cardiotoxicity holds promise for increased specificity and sensitivity in detecting early anthracycline-induced cardiotoxicity. miRNAs (microRNAs), small single-stranded, noncoding RNA sequences involved in epigenetic regulation, influence various physiological and pathological processes by targeting expression and translation. Emerging as new biomarker candidates, circulating miRNAs exhibit resistance to degradation and offer a direct pathomechanistic link. This review comprehensively outlines their potential as early biomarkers for cardiotoxicity and their pathomechanistic link.

Unlocking the dark matter: noncoding RNAs and RNA modifications in cardiac aging

Cardiac aging is a multifaceted process that encompasses structural and functional alterations culminating in heart failure. As the elderly population continues to expand, there is a growing urgent need for interventions to combat age-related cardiac functional decline. Noncoding RNAs have emerged as critical regulators of cellular and biochemical processes underlying cardiac disease. This review summarizes our current understanding of how noncoding RNAs function in the heart during aging, with particular emphasis on mechanisms of RNA modification that control their activity. Targeting noncoding RNAs as potential novel therapeutics in cardiac aging is also discussed.

Identification of novel endogenous control miRNAs in heart failure for normalization of qPCR data

MicroRNAs (miRNAs), a class of non-coding RNAs, are utilized as biomarkers for a wide range of disorders. Circulating miRNAs are proposed as potential markers in the clinical identification of heart failure (HF). However, identifying miRNA biomarkers in HF requires identification of robust endogenous control miRNAs for normalization in differential expression analysis. Hence, this study aimed to identify circulating miRNAs that can be utilized as endogenous controls in HF. We evaluated the expression of eight miRNAs, which were previously reported as endogenous controls in different pathological conditions. Total RNA, including miRNA, was extracted from the serum samples of 30 HF patients (15 HFrEF and 15 HFpEF) and their matched controls (n = 15). We used quantitative PCR to determine the miRNA expression. The stability of the selected endogenous miRNAs was assessed and compared using a standard set of criteria with the RefFinder software. Six of the eight miRNAs analyzed showed consistent expression among all sample groups. Stability analysis ranked hsa-let-7i-5p, hsa-miR-148b-3p, and hsa-miR-484 as the most stable miRNAs, indicating their potential as reliable endogenous controls.

Sex-Biased Expression and Response of microRNAs in Neurological Diseases and Neurotrauma

Neurological diseases and neurotrauma manifest significant sex differences in prevalence, progression, outcome, and therapeutic responses. Genetic predisposition, sex hormones, inflammation, and environmental exposures are among many physiological and pathological factors that impact the sex disparity in neurological diseases. MicroRNAs (miRNAs) are a powerful class of gene expression regulator that are extensively involved in mediating biological pathways. Emerging evidence demonstrates that miRNAs play a crucial role in the sex dimorphism observed in various human diseases, including neurological diseases. Understanding the sex differences in miRNA expression and response is believed to have important implications for assessing the risk of neurological disease, defining therapeutic intervention strategies, and advancing both basic research and clinical investigations. However, there is limited research exploring the extent to which miRNAs contribute to the sex disparities observed in various neurological diseases. Here, we review the current state of knowledge related to the sexual dimorphism in miRNAs in neurological diseases and neurotrauma research. We also discuss how sex chromosomes may contribute to the miRNA sexual dimorphism phenomenon. We attempt to emphasize the significance of sexual dimorphism in miRNA biology in human diseases and to advocate a gender/sex-balanced science.

microRNAs are differentially expressed in equine plasma of horses with osteoarthritis and osteochondritis dissecans versus control horses

Osteoarthritis (OA) is a leading cause of lameness in horses with no effective disease-modifying treatment and challenging early diagnosis. OA is considered a disease of the joint involving the articular cartilage, subchondral bone, synovial membrane, and ligaments. Osteochondritis dissecans (OCD) is a joint disease consisting of focal defects in the osteochondral unit which may progress to OA later in life. MicroRNAs (miRNAs) have been recognized as small non-coding RNAs that regulate a variety of biological processes and have been detected in biological fluids. MiRNAs are currently investigated for their utility as biomarkers and druggable targets for a variety of diseases. The current study hypothesizes that miRNA profiles can be used to actively monitor joint health and differences in miRNA profiles will be found in healthy vs diseased joints and that differences will be detectable in blood plasma of tested horses. Five horses with OA, OCD, and 4 controls (C) had blood plasma and synovial fluid collected. Total RNA, including miRNA was isolated before generating miRNA libraries from the plasma of the horses. Libraries were sequenced at the Schroeder Arthritis Institute (Toronto). Differential expression analysis was done using DESeq2 and validated using ddPCR. KEGG pathway analysis was done using mirPath v.3 (Diana Tools). 57 differentially expressed miRNAs were identified in OA vs C plasma, 45 differentially expressed miRNAs in OC vs C plasma, and 21 differentially expressed miRNAs in OA vs OCD plasma. Notably, miR-140-5p expression was observed to be elevated in OA synovial fluid suggesting that miR-140-5p may serve as a protective marker early on to attenuate OA progression. KEGG pathway analysis of differentially expressed plasma miRNAs showed relationships with glycan degradation, glycosaminoglycan degradation, and hippo signaling pathway. Interestingly, ddPCR was unable to validate the NGS data suggesting that isomiRs may play an integral role in miRNA expression when assessed using NGS technologies.

miRNAs as Biomolecular Markers for Food Safety, Quality, and Traceability in Poultry Meat-A Preliminary Study

In this study, the expression and abundance of two candidate chicken (Gallus gallus; gga) microRNAs (miRNAs, miR), gga-miR-21-5p (miR-21) and gga-miR-126-5p (miR-126), have been analyzed in order to identify biomarkers for the traceability and quality of poultry meat. Two breeds of broiler chickens were tested: the most common Ross308 (fast-growing) and the high-quality Ranger Gold (slow-growing). A preliminary analysis of the two miRNAs expressions was conducted across various tissues (liver, lung, spleen, skeletal muscle, and kidney), and the three tissues (lung, spleen, and muscle) with a higher expression were chosen for further analysis. Using quantitative reverse transcription polymerase chain reaction (RT-qPCR), the expression of miRNAs in the three tissues of a total of thirteen animals was determined. The results indicate that miR-126 could be a promising biomarker for the lung tissue in the Ranger Gold (RG) breed (p < 0.01), thus suggesting a potential applicability for tracing hybrids. RG exhibits a significantly higher miR-126 expression in the lung tissue compared to the Ross308 broilers (R308), an indication of greater respiratory capacity and, consequently, a higher oxidative metabolism of the fast-growing hybrid. During sampling, two R308 broilers presented some anomalies, including airsacculitis, hepatic steatosis, and enlarged spleen. The expression of miR-126 and miR-21 was compared in healthy animals and in those presenting anomalies. Chickens with airsacculitis and hepatic steatosis showed an up-regulation of miR-21 and miR-126 in the most commercially valuable tissue, the skeletal muscle or breast (p < 0.05).

Mechanisms and consequences of sex differences in immune responses

Biological sex differences refer to differences between males and females caused by the sex chromosome complement (that is, XY or XX), reproductive tissues (that is, the presence of testes or ovaries), and concentrations of sex steroids (that is, testosterone or oestrogens and progesterone). Although these sex differences are binary for most human individuals and mice, transgender individuals receiving hormone therapy, individuals with genetic syndromes (for example, Klinefelter and Turner syndromes) and people with disorders of sexual development reflect the diversity in sex-based biology. The broad distribution of sex steroid hormone receptors across diverse cell types and the differential expression of X-linked and autosomal genes means that sex is a biological variable that can affect the function of all physiological systems, including the immune system. Sex differences in immune cell function and immune responses to foreign and self antigens affect the development and outcome of diverse diseases and immune responses.

Early-life exposure to gestational diabetes mellitus predisposes offspring to pediatric nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has emerged as the prevailing chronic liver disease in the pediatric population due to the global obesity pandemic. Evidence shows that prenatal and postnatal exposure to maternal abnormalities leads to a higher risk of pediatric NAFLD through persistent alterations in developmental programming. Gestational diabetes mellitus (GDM) is a hyperglycemic syndrome which has become the most prevalent complication in pregnant women. An increasing number of both epidemiologic investigations and animal model studies have validated adverse and long-term outcomes in offspring following GDM exposure in utero. Similarly, GDM is considered a crucial risk factor for pediatric NAFLD. This review aimed to summarize currently published studies concerning the inductive roles of GDM in offspring NAFLD development during childhood and adolescence. Dysregulations in hepatic lipid metabolism and gut microbiota in offspring, as well as dysfunctions in the placenta are potential factors in the pathogenesis of GDM-associated pediatric NAFLD. In addition, potentially effective interventions for GDM-associated offspring NAFLD are also discussed in this review. However, most of these therapeutic approaches still require further clinical research for validation.

Small non-coding RNA profiling in patients with gastrointestinal cancer

BACKGROUND

Small non-coding (snc)RNAs, including microRNAs and P-element induced wimpy testis (PIWI)-interacting-RNAs (piRNAs), crucially regulate gene expression in both physiological and pathological conditions. In particular, some muscle-specific microRNAs (myomiRs) have been involved in the pathogenesis of cancer-induced muscle wasting. The aims of the present study were (i) to profile sncRNAs in both skeletal muscle and plasma of gastrointestinal cancer patients and (ii) to investigate the association among differentially expressed sncRNAs and the level of muscularity at body composition analysis.

METHODS

Surgical patients with gastrointestinal cancer or benign disease were recruited. Blood samples and muscle biopsies (rectus abdominis) were collected during surgery. Low muscularity patients were those at the lowest tertile of skeletal muscle index (SMI; CT-scan), whereas moderate/high muscularity patients were in the middle and highest SMI tertiles. SncRNAs in the muscle were assessed by RNAseq, circulating microRNAs were evaluated by qPCR.

RESULTS

Cancer patients (n = 25; 13 females, 52%) showed a mean age of 71.6 ± 11.2 years, a median body weight loss of 4.2% and a mean BMI of 27.0 ± 3.2 kg/m2 . Control group (n = 15; 9 females, 60%) showed a mean age 58.1 ± 13.9 years and a mean BMI of 28.0 ± 4.3 kg/m2 . In cancer patients, the median L3-SMI (cm2 /m2 ) was 42.52 (34.42; 49.07). Males showed a median L3-SMI of 46.08 (41.17-51.79) and females a median L3-SMI of 40.77 (33.73-42.87). Moderate-high and low muscularity groups included 17 and 8 patients, respectively. As for circulating microRNAs, miR-21-5p and miR-133a-3p were up-regulated in patients compared with controls, whereas miR-15b-5p resulted down-regulated in the same comparison (about 30% of control values). Sample clustering by muscularity and sex revealed increased miR-133a-3p and miR-206 only in moderate-high muscularity males. SncRNA profiling in the muscle identified 373 microRNAs and 190 piRNAs (72.5% and 18.7% of raw reads, respectively). As for microRNAs, 10 were up-regulated, and 56 were down-regulated in cancer patients versus controls. Among the 24 dysregulated piRNAs, the majority were down-regulated, including the top two most expressed piRNAs in the muscle (piR-12790 and piR-2106). Network analysis on validated mRNA targets of down-regulated microRNAs revealed miR-15b-5p, miR-106a-5p and miR-106b-5p as main interactors of genes related to ubiquitin ligase/transferase activities.

CONCLUSIONS

These results show dysregulation of both muscle microRNAs and piRNAs in cancer patients compared with controls, the former following a sex-specific pattern. Changes in circulating microRNAs are associated with the degree of muscularity rather than body weight loss.

Exosomal miRNAs as Biomarkers of Ischemic Stroke

Exosomes are small lipid bilayer membrane particles released from all living cells into the extracellular environment. They carry several molecules and have a critical role in cell-cell communication under physiological and pathological conditions. In recent decades, exosomes, and especially their cargo, have emerged as a promising tool for several clinical conditions. However, the literature has become increasingly unambiguous in defining the role of exosomes in chronic cerebrovascular diseases. Because they can pass through the blood-brain barrier, they have great potential to reflect intracerebral changes. They can, thus, provide valuable insight into the mechanisms of central nervous system diseases. The purpose of this review is to describe the literature on the role of exosomal miRNA, which represents the most widely investigated exosomal biomarker, in strokes. First, we provide an overview of exosomes, from biology to isolation and characterization. Then, we describe the relationship between exosomes and stroke pathogenesis. Finally, we summarize the human studies evaluating exosomal miRNA biomarkers of stroke. Although the collective literature supports the potential use of exosomal miRNA as biomarkers of ischemic stroke, there are still several limitations hampering their introduction into clinical practice.

The role of genetics and gender specific differences in neurodegenerative disorders: Insights from molecular and immune landscape

Neurodegenerative disorders (NDDs) are the most common neurological disorders with high prevalence and have significant socioeconomic implications. Understanding the underlying cellular and molecular mechanisms associated with the immune system can be effective in disease etiology, leading to more effective therapeutic approaches for both females and males. The central nervous system (CNS) actively participates in immune responses, both within and outside the CNS. Immune system activation is a common feature in NDDs. Gender-specific factors play a significant role in the prevalence, progression, and manifestation of NDDs. Neuroinflammation, in both inflammatory neurological and neurodegenerative conditions, is defined by the triggering of microglia and astrocyte cell activation. This results in the secretion of pro-inflammatory cytokines and chemokines. Numerous studies have documented the role of neuroinflammation in neurological diseases, highlighting the involvement of immune signaling pathways in disease development. Converging evidence support immune system involvement during neurodegeneration in NDDs. In this review, we summarize emerging evidence that reveals gender-dependent differences in immune responses related to NDDs. Also, we highlight sex differences in immune responses and discuss how these sex-specific influences can increase the risk of NDDs. Understanding the role of gender-specific factors can aid in developing targeted therapeutic strategies and improving patient outcomes. Ultimately, the better understanding of these mechanisms contributed to sex-dependent immune response in NDDs, can be critically usful in targeting of immune signaling cascades in such disorders. In this regard, sex-related immune responses in NDDs may be promising and effective targets in therapeutic strategies.

A plasma miRNA-based classifier for small cell lung cancer diagnosis

Introduction

Small cell lung cancer (SCLC) is characterized by poor prognosis and challenging diagnosis. Screening in high-risk smokers results in a reduction in lung cancer mortality, however, screening efforts are primarily focused on non-small cell lung cancer (NSCLC). SCLC diagnosis and surveillance remain significant challenges. The aberrant expression of circulating microRNAs (miRNAs/miRs) is reported in many tumors and can provide insights into the pathogenesis of tumor development and progression. Here, we conducted a comprehensive assessment of circulating miRNAs in SCLC with a goal of developing a miRNA-based classifier to assist in SCLC diagnoses.

Methods

We profiled deregulated circulating cell-free miRNAs in the plasma of SCLC patients. We tested selected miRNAs on a training cohort and created a classifier by integrating miRNA expression and patients' clinical data. Finally, we applied the classifier on a validation dataset.

Results

We determined that miR-375-3p can discriminate between SCLC and NSCLC patients, and between SCLC and Squamous Cell Carcinoma patients. Moreover, we found that a model comprising miR-375-3p, miR-320b, and miR-144-3p can be integrated with race and age to distinguish metastatic SCLC from a control group.

Discussion

This study proposes a miRNA-based biomarker classifier for SCLC that considers clinical demographics with specific cut offs to inform SCLC diagnosis.

Sex differences in brain protein expression and disease

Most complex human traits differ by sex, but we have limited insight into the underlying mechanisms. Here, we investigated the influence of biological sex on protein expression and its genetic regulation in 1,277 human brain proteomes. We found that 13.2% (1,354) of brain proteins had sex-differentiated abundance and 1.5% (150) of proteins had sex-biased protein quantitative trait loci (sb-pQTLs). Among genes with sex-biased expression, we found 67% concordance between sex-differentiated protein and transcript levels; however, sex effects on the genetic regulation of expression were more evident at the protein level. Considering 24 psychiatric, neurologic and brain morphologic traits, we found that an average of 25% of their putatively causal genes had sex-differentiated protein abundance and 12 putatively causal proteins had sb-pQTLs. Furthermore, integrating sex-specific pQTLs with sex-stratified genome-wide association studies of six psychiatric and neurologic conditions, we uncovered another 23 proteins contributing to these traits in one sex but not the other. Together, these findings begin to provide insights into mechanisms underlying sex differences in brain protein expression and disease.

Hypertension after the Menopause: What Can We Learn from Experimental Studies?

Hypertension is the most prevalent cardiovascular disease of the adult population and is closely associated with serious cardiovascular events. The burden of hypertension with respect to vascular and other organ damage is greater in women. These sex differences are not fully understood. The unique feature in women is their transition to menopause accompanied by profound hormonal changes that affect the vasculature that are also associated with changes of blood pressure. Results from studies of hormone replacement therapy and its effects on the cardiovascular system are controversial, and the timing of treatment after menopause seems to be important. Therefore, revealing potential sex- and sex hormone-dependent pathophysiological mechanisms of hypertension in experimental studies could provide valuable information for better treatment of hypertension and vascular impairment, especially in postmenopausal women. The experimental rat models subjected to ovariectomy mimicking menopause could be useful tools for studying the mechanisms of blood pressure regulation after menopause and during subsequent therapy.

Recent advances in the role of miRNAs in post-traumatic stress disorder and traumatic brain injury

Post-traumatic stress disorder (PTSD) is usually considered a psychiatric disorder upon emotional trauma. However, with the rising number of conflicts and traffic accidents around the world, the incidence of PTSD has skyrocketed along with traumatic brain injury (TBI), a complex neuropathological disease due to external physical force and is also the most common concurrent disease of PTSD. Recently, the overlap between PTSD and TBI is increasingly attracting attention, as it has the potential to stimulate the emergence of novel treatments for both conditions. Of note, treatments exploiting the microRNAs (miRNAs), a well-known class of small non-coding RNAs (ncRNAs), have rapidly gained momentum in many nervous system disorders, given the miRNAs' multitudinous and key regulatory role in various biological processes, including neural development and normal functioning of the nervous system. Currently, a wealth of studies has elucidated the similarities of PTSD and TBI in pathophysiology and symptoms; however, there is a dearth of discussion with respect to miRNAs in both PTSD and TBI. In this review, we summarize the recent available studies of miRNAs in PTSD and TBI and discuss and highlight promising miRNAs therapeutics for both conditions in the future.

The Effect of Sex-Specific Differences on IL-10-/- Mouse Colitis Phenotype and Microbiota

Sexual dimorphism is an important factor in understanding various diseases, including inflammatory bowel disease (IBD). While females typically exhibit stronger immune responses, the role of sex in IBD remains unclear. This study aimed to explore the sex-dependent differences and inflammatory susceptibility in the most extensively used IBD mouse model as they developed colitis. We monitored IL10-deficient mice (IL-10-/-) up to 17 weeks of age and characterized their colonic and fecal inflammatory phenotype, as well as their microbiota changes. Here, we originally identified IL-10-/- female mice as more prone to developing intestinal inflammation, with an increase in fecal miR-21, and dysbiosis with more detrimental characteristics compared to males. Our findings provide valuable insights into the sex-based differences in the pathophysiology of colitis and emphasize the importance of considering sex in experimental designs. Moreover, this study paves the way for future investigations aiming at addressing sex-related differences for the development of adequate disease models and therapeutic strategies, ideally enabling personalized medicine.

Sex-biased expression of selected chromosome x-linked microRNAs with potent regulatory effect on the inflammatory response in children with cystic fibrosis: A preliminary pilot investigation

Previous studies have reported sex disparity in cystic fibrosis (CF) disease, with females experiencing more pulmonary exacerbations and frequent microbial infections resulting in shorter survival expectancy. This concerns both pubertal and prepubertal females, which is in support to the prominent role of gene dosage rather than the hormonal status. The underlying mechanisms are still poorly understood. The X chromosome codes for a large number of micro-RNAs (miRNAs) that play a crucial role in the post-transcriptional regulation of several genes involved in various biological processes, including inflammation. However, their level of expression in CF males and females has not been sufficiently explored. In this study, we compared in male and female CF patients the expression of selected X-linked miRNAs involved in inflammatory processes. Cytokine and chemokine profiles were also evaluated at both protein and transcript levels and cross-analyzed with the miRNA expression levels. We observed increased expression of miR-223-3p, miR-106a-5p, miR-221-3p and miR-502-5p in CF patients compared to healthy controls. Interestingly, the overexpression of miR-221-3p was found to be significantly higher in CF girls than in CF boys and this correlates positively with IL-1β. Moreover, we found a trend toward lower expression in CF girls than in CF boys of suppressor of cytokine signaling 1 (SOCS1) and the ubiquitin-editing enzyme PDLIM2, two mRNA targets of miR-221-3p that are known to inhibit the NF-κB pathway. Collectively, this clinical study highlights a sex-bias in X-linked miR-221-3p expression in blood cells and its potential contribution to sustaining a higher inflammatory response in CF girls.

Identification of a miRNA Panel with a Potential Determinant Role in Patients Suffering from Periodontitis

In recent years, the role of microRNA (miRNA) in post-transcriptional gene regulation has advanced and supports strong evidence related to their important role in the regulation of a wide range of fundamental biological processes. Our study focuses on identifying specific alterations of miRNA patterns in periodontitis compared with healthy subjects. In the present study, we mapped the major miRNAs altered in patients with periodontitis (n = 3) compared with healthy subjects (n = 5), using microarray technology followed by a validation step by qRT-PCR and Ingenuity Pathways Analysis. Compared to healthy subjects, 159 differentially expressed miRNAs were identified among periodontitis patients, of which 89 were downregulated, and 70 were upregulated, considering a fold change of ±1.5 as the cut-off value and p ≤ 0.05. Key angiogenic miRNAs (miR-191-3p, miR-221-3p, miR-224-5p, miR-1228-3p) were further validated on a separate cohort of patients with periodontitis versus healthy controls by qRT-PCR, confirming the microarray data. Our findings indicate a periodontitis-specific miRNA expression pattern representing an essential issue for testing new potential diagnostic or prognostic biomarkers for periodontal disease. The identified miRNA profile in periodontal gingival tissue was linked to angiogenesis, with an important molecular mechanism that orchestrates cell fate.

The long-lasting effects of early life adversities are sex dependent: The signature of miR-34a

BACKGROUND

Exposure to early life adversities (ELA) can influence a plethora of biological mechanisms leading to stress-related disorders later in life through epigenetic mechanisms, such as microRNAs (miRs). MiR-34 is a critical modulator of stress response and stress-induced pathologies and a link between ELA and miR-34a has been reported.

METHODS

Here using our well-established model of ELA (Repeated Cross Fostering) we investigate the behavioral long-term effects of ELA in male and female mice. We also assess basal and ELA-induced miR-34a expression in adult mice and investigate whether ELA affects the later miR-34a response to adult acute stress exposure across brain areas (medial preFrontal Cortex, Dorsal Raphe Nuclei) and peripheral organs (heart, plasma) in animals from both sexes. Finally, based on our previous data demonstrating the critical role of Dorsal Raphe Nuclei miR-34a expression in serotonin (5-HT) transmission, we also investigated prefrontal-accumbal 5-HT outflow induced by acute stress exposure in ELA and Control females by in vivo intracerebral microdialysis.

RESULTS

ELA not just induces a depressive-like state as well as enduring changes in miR-34a expression, but also alters miR-34a expression in response to adult acute stress exclusively in females. Finally, altered DRN miR-34a expression is associated with prefrontal-accumbal 5-HT release under acute stress exposure in females.

LIMITATIONS

Translational study on humans is necessary to verify the results obtained in our animal models of ELA-induced depression.

CONCLUSIONS

This is the first evidence showing long-lasting sex related effects of ELA on brain and peripheral miR-34a expression levels in an animal model of depression-like phenotype.

Sex-Specific miRNA Differences in Liquid Biopsies from Subjects with Solid Tumors and Healthy Controls

Dysregulation of epigenetic mechanisms has been recognized to play a crucial role in cancer development, but these mechanisms vary between sexes. Therefore, we focused on sex-specific differences in the context of cancer-based data from a recent study. A total of 12 cell-free DNA methylation targets in CpG-rich promoter regions and 48 miRNAs were analyzed by qPCR in plasma samples from 8 female and 7 male healthy controls as well as 48 female and 80 male subjects with solid tumors of the bladder, brain, colorectal region (CRC), lung, stomach, pancreas, and liver. Due to the small sample size in some groups and/or the non-balanced distribution of men and women, sex-specific differences were evaluated statistically only in healthy subjects, CRC, stomach or pancreas cancer patients, and all cancer subjects combined (n female/male-8/7, 14/14, 8/15, 6/6, 48/80, respectively). Several miRNAs with opposing expressions between the sexes were observed for healthy subjects (miR-17-5p, miR-26b-5p); CRC patients (miR-186-5p, miR-22-3p, miR-22-5p, miR-25-3p, miR-92a-3p, miR-16-5p); stomach cancer patients (miR-133a-3p, miR-22-5p); and all cancer patients combined (miR-126-3p, miR-21-5p, miR-92a-3p, miR-183-5p). Moreover, sex-specific correlations that were dependent on cancer stage were observed in women (miR-27a-3p) and men (miR-17-5p, miR-20a-5p). Our results indicate the complex and distinct role of epigenetic regulation, particularly miRNAs, depending not only on the health status but also on the sex of the patient. The same miRNAs could have diverse effects in different tissues and opposing effects between the biological sexes, which should be considered in biomarker research.

BMPR2 Mutation and Metabolic Reprogramming in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension forms the first and most severe of the 5 categories of pulmonary hypertension. Disease pathogenesis is driven by progressive remodeling of peripheral pulmonary arteries, caused by the excessive proliferation of vascular wall cells, including endothelial cells, smooth muscle cells and fibroblasts, and perivascular inflammation. Compelling evidence from animal models suggests endothelial cell dysfunction is a key initial trigger of pulmonary vascular remodeling, which is characterised by hyperproliferation and early apoptosis followed by enrichment of apoptosis-resistant populations. Dysfunctional pulmonary arterial endothelial cells lose their ability to produce vasodilatory mediators, together leading to augmented pulmonary arterial smooth muscle cell responses, increased pulmonary vascular pressures and right ventricular afterload, and progressive right ventricular hypertrophy and heart failure. It is recognized that a range of abnormal cellular molecular signatures underpin the pathophysiology of pulmonary arterial hypertension and are enhanced by loss-of-function mutations in the BMPR2 gene, the most common genetic cause of pulmonary arterial hypertension and associated with worse disease prognosis. Widespread metabolic abnormalities are observed in the heart, pulmonary vasculature, and systemic tissues, and may underpin heterogeneity in responsivity to treatment. Metabolic abnormalities include hyperglycolytic reprogramming, mitochondrial dysfunction, aberrant polyamine and sphingosine metabolism, reduced insulin sensitivity, and defective iron handling. This review critically discusses published mechanisms linking metabolic abnormalities with dysfunctional BMPR2 (bone morphogenetic protein receptor 2) signaling; hypothesized mechanistic links requiring further validation; and their relevance to pulmonary arterial hypertension pathogenesis and the development of potential therapeutic strategies.

Circulating MicroRNAs: Diagnostic Value as Biomarkers in the Detection of Non-alcoholic Fatty Liver Diseases and Hepatocellular Carcinoma

Non-alcoholic fatty liver disease (NAFLD), a metabolic-related disorder, is the most common cause of chronic liver disease which, if left untreated, can progress from simple steatosis to advanced fibrosis and eventually cirrhosis or hepatocellular carcinoma, which is the leading cause of hepatic damage globally. Currently available diagnostic modalities for NAFLD and hepatocellular carcinoma are mostly invasive and of limited precision. A liver biopsy is the most widely used diagnostic tool for hepatic disease. But due to its invasive procedure, it is not practicable for mass screening. Thus, noninvasive biomarkers are needed to diagnose NAFLD and HCC, monitor disease progression, and determine treatment response. Various studies indicated that serum miRNAs could serve as noninvasive biomarkers for both NAFLD and HCC diagnosis because of their association with different histological features of the disease. Although microRNAs are promising and clinically useful biomarkers for hepatic diseases, larger standardization procedures and studies are still required.

Sex-Specific Alterations in Inflammatory MicroRNAs in Mouse Brain and Bone Marrow CD11b+ Cells Following Traumatic Brain Injury

Sex is a key biological variable in traumatic brain injury (TBI) and plays a significant role in neuroinflammatory responses. However, the molecular mechanisms contributing to this sexually dimorphic neuroinflammatory response remain elusive. Here we describe a significant and previously unreported tissue enrichment and sex-specific alteration of a set of inflammatory microRNAs (miRNAs) in CD11b+ cells of brain and bone marrow isolated from naïve mice as well as mice subjected to TBI. Our data from naïve mice demonstrated that expression levels of miR-146a-5p and miR-150-5p were relatively higher in brain CD11b+ cells, and that miR-155-5p and miR-223-3p were highly enriched in bone marrow CD11b+ cells. Furthermore, while miR-150-5p and miR-155-5p levels were higher in male brain CD11b+ cells, no significant sexual difference was observed for miR-146a-5p and miR-223-3p. However, TBI resulted in sex-specific differential responses of these miRNAs in brain CD11b+ cells. Specifically, miR-223-3p levels in brain CD11b+ cells were markedly elevated in both sexes in response to TBI at 3 and 24 h, with levels in females being significantly higher than males at 24 h. We then focused on analyzing several miR-223-3p targets and inflammation-related marker genes following injury. Corresponding to the greater elevation of miR-223-3p in females, the miR-223-3p targets, TRAF6 and FBXW7 were significantly reduced in females compared to males. Interestingly, anti-inflammatory genes ARG1 and IL4 were higher in females after TBI than in males. These observations suggest miR-223-3p and other inflammatory responsive miRNAs may play a key role in sex-specific neuroinflammatory response following TBI.

Circulating microRNAs Showed Specific Responses according to Metabolic Syndrome Components and Sex of Adults from a Population-Based Study

MicroRNAs (miRNAs) regulate several metabolic pathways and are potential biomarkers for early risk prediction of metabolic syndrome (MetS). Our aim was to evaluate the levels of 21 miRNAs in plasma according to MetS components and sex in adults. We employed a cross-sectional study of 192 adults aged 20 to 59 years old from the 2015 Health Survey of São Paulo with Focus in Nutrition. Data showed reduced levels of miR-16 and miR-363 in women with MetS; however, men with one or more risk factors showed higher levels of miR-let-7c and miR-30a. Individuals with raised waist circumference showed higher levels of miR-let-7c, miR-122, miR-30a, miR-146a, miR-15a, miR-30d and miR-222. Individuals with raised blood pressure had higher miR-30a, miR-122 and miR-30a levels. Plasma levels of four miRNAs (miR-16, miR-363, miR-375 and miR-486) were lower in individuals with low HDL-cholesterol concentrations. In addition, plasma levels of five miRNAs (miR-122, miR-139, miR-let-7c, miR-126 and miR-30a) were increased in individuals with high fasting plasma glucose and/or insulin resistance. Our results suggest that the pattern of miRNA levels in plasma may be a useful early biomarker of cardiometabolic components of MetS and highlight the sex differences in the plasma levels of miRNAs in individuals with MetS.

Segmental Upregulation of ASIC1 Channels in the Formalin Acute Pain Mouse Model

BACKGROUND

Hindpaw injection of formalin in rodents is used to assess acute persistent pain. The response to formalin is biphasic. The initial response (first minutes) is thought to be linked to inflammatory, peripheral mechanisms, while the latter (around 30 min after the injection), is linked to central mechanisms. This model is useful to analyze the effect of drugs at one or both phases, and the involvement of ion channels in the response. Acid-sensing ion channels (ASICs) regulate synaptic activities and play important roles in pain conditions. Recently, psalmotoxin-1 (Pctx-1), a toxin that inhibits ASIC1a-constituted channels, and antisense ASIC1a-RNA, intrathecal administered in mice were shown to affect both phases of the test.

METHODS

The mouse formalin test was performed on C57/BL6 7- to 9-week-old mice. Behavioral tests were conducted and tissue was extracted to detect proteins (ASIC1 and pERK) and ASIC1-mRNA and mir485-5p levels.

RESULTS

The injection of formalin was accompanied by an increase in ASIC1 levels. This was detected at the contralateral anterior cingulate cortex (ACC) compared to the ipsilateral side, and both sides of the ACC of vehicle-injected animals. At the spinal cord and dorsal root ganglia, ASIC1 levels followed a gradient stronger at lumbar (L) 3 and decreased towards L5. Gender differences were detected at the ACC; with female mice showing higher ASIC1a levels at the ACC. No significant changes in ASIC1-mRNA levels were detected. Evidence suggests ASIC1 upregulation depends on regulatory microRNAs.

CONCLUSION

This work highlights the important role of ASIC1 in pain and the potential role of pharmacological therapies aimed at this channel.

Blood Biomarkers for the Diagnosis of Neurodegenerative Dementia: A Systematic Review

IMPORTANCE

Accurately diagnosing neurodegenerative dementia is often challenging due to overlapping clinical features. Disease specific biomarkers could enhance diagnostic accuracy. However, CSF analysis procedures and advanced imaging modalities are either invasive or high-priced, and routinely unavailable. Easily accessible disease biomarkers would be of utmost value for accurate differential diagnosis of dementia subtypes.

OBJECTIVE

To assess the diagnostic accuracy of blood-based biomarkers for the differential diagnosis of AD from Frontotemporal Lobar Degeneration (FTLD), or AD from Dementia with Lewy Bodies (DLB).

METHODS

Systematic review. Three databases (PubMed, Scopus, and Web of Science) were searched. Studies assessing blood-based biomarkers levels in AD versus FTLD, or AD versus DLB, and its diagnostic accuracy, were selected. When the same biomarker was assessed in three or more studies, a meta-analysis was performed. QUADAS-2 criteria were used for quality assessment.

RESULTS

Twenty studies were included in this analysis. Collectively, 905 AD patients were compared to 1262 FTLD patients, and 209 AD patients were compared to 246 DLB patients. Regarding biomarkers for AD versus FTLD, excellent discriminative accuracy (AUC >0.9) was found for p-tau181, p-tau217, synaptophysin, synaptopodin, GAP43 and calmodulin. Other biomarkers also demonstrated good accuracy (AUC = 0.8-0.9). For AD versus DLB distinction, only miR-21-5p and miR-451a achieved excellent accuracy (AUC >0.9).

CONCLUSION

Encouraging results were found for several biomarkers, alone or in combination. Prospective longitudinal designs and consensual protocols, comprising larger cohorts and homogeneous testing modalities across centres, are essential to validate the clinical value of blood biomarkers for the precise etiological diagnosis of dementia.

Circulating microRNA Related to Cardiometabolic Risk Factors for Metabolic Syndrome: A Systematic Review

MicroRNA regulates multiple pathways in inflammatory response, adipogenesis, and glucose and lipid metabolism, which are involved in metabolic syndrome (MetS). Thus, this systematic review aimed at synthesizing the evidence on the relationships between circulating microRNA and risk factors for MetS. The systematic review was registered in the PROSPERO database (CRD42020168100) and included 24 case-control studies evaluating microRNA expression in serum/plasma of individuals ≥5 years old. Most of the studies focused on 13 microRNAs with higher frequency and there were robust connections between miR-146a and miR-122 with risk factors for MetS, based on average weighted degree. In addition, there was an association of miR-222 with adiposity, lipid metabolism, glycemic metabolism, and chronic inflammation and an association of miR-126, miR-221, and miR-423 with adiposity, lipid, and glycemic metabolism. A major part of circulating microRNA was upregulated in individuals with risk factors for MetS, showing correlations with glycemic and lipid markers and body adiposity. Circulating microRNA showed distinct expression profiles according to the clinical condition of individuals, being particularly linked with increased body fat. However, the exploration of factors associated with variations in microRNA expression was limited by the variety of microRNAs investigated by risk factor in diverse studies identified in this systematic review.

Confounding Factors Impacting microRNA Expression in Human Saliva: Methodological and Biological Considerations

There is growing interest in saliva microRNAs (miRNAs) as non-invasive biomarkers for human disease. Such an approach requires understanding how differences in experimental design affect miRNA expression. Variations in technical methodologies, coupled with inter-individual variability may reduce study reproducibility and generalizability. Another barrier facing salivary miRNA biomarker research is a lack of recognized “control miRNAs”. In one of the largest studies of human salivary miRNA to date (922 healthy individuals), we utilized 1225 saliva samples to quantify variability in miRNA expression resulting from aligner selection (Bowtie1 vs. Bowtie2), saliva collection method (expectorated vs. swabbed), RNA stabilizer (presence vs. absence), and individual biological factors (sex, age, body mass index, exercise, caloric intake). Differential expression analyses revealed that absence of RNA stabilizer introduced the greatest variability, followed by differences in methods of collection and aligner. Biological factors generally affected a smaller number of miRNAs. We also reported coefficients of variations for 643 miRNAs consistently present in saliva, highlighting several salivary miRNAs to serve as reference genes. Thus, the results of this analysis can be used by researchers to optimize parameters of salivary miRNA measurement, exclude miRNAs confounded by numerous biologic factors, and identify appropriate miRNA controls.

Sex at the interface: the origin and impact of sex differences in the developing human placenta

The fetal placenta is a source of hormones and immune factors that play a vital role in maintaining pregnancy and facilitating fetal growth. Cells in this extraembryonic compartment match the chromosomal sex of the embryo itself. Sex differences have been observed in common gestational pathologies, highlighting the importance of maternal immune tolerance to the fetal compartment. Over the past decade, several studies examining placentas from term pregnancies have revealed widespread sex differences in hormone signaling, immune signaling, and metabolic functions. Given the rapid and dynamic development of the human placenta, sex differences that exist at term (37–42 weeks gestation) are unlikely to align precisely with those present at earlier stages when the fetal–maternal interface is being formed and the foundations of a healthy or diseased pregnancy are established. While fetal sex as a variable is often left unreported in studies performing transcriptomic profiling of the first-trimester human placenta, four recent studies have specifically examined fetal sex in early human placental development. In this review, we discuss the findings from these publications and consider the evidence for the genetic, hormonal, and immune mechanisms that are theorized to account for sex differences in early human placenta. We also highlight the cellular and molecular processes that are most likely to be impacted by fetal sex and the evolutionary pressures that may have given rise to these differences. With growing recognition of the fetal origins of health and disease, it is important to shed light on sex differences in early prenatal development, as these observations may unlock insight into the foundations of sex-biased pathologies that emerge later in life.

Placental sex differences exist from early prenatal development, and may help explain sex differences in pregnancy outcomes.

Transcriptome profiling of early to mid-gestation placenta reveals that immune signaling is a hub of early prenatal sex differences.

Differentially expressed genes between male and female placenta fall into the following functional associations: chromatin modification, transcription, splicing, translation, signal transduction, metabolic regulation, cell death and autophagy regulation, ubiquitination, cell adhesion and cell–cell interaction.

Placental sex differences likely reflect the interaction of cell-intrinsic chromosome complement with extrinsic endocrine signals from the fetal compartment that accompany gonadal differentiation.

Understanding the mechanisms behind sex differences in placental development and function will provide key insight into molecular targets that can be modulated to improve sex-biased obstetrical complications.

Serum microRNAs targeting ACE2 and RAB14 genes distinguish asymptomatic from critical COVID-19 patients

Despite the extraordinary advances achieved to beat COVID-19 disease, many questions remain unsolved, including the mechanisms of action of SARS-CoV-2 and which factors determine why individuals respond so differently to the viral infection. Herein, we performed an in silico analysis to identify host microRNA targeting ACE2, TMPRSS2, and/or RAB14, all genes known to participate in viral entry and replication. Next, the levels of six microRNA candidates previously linked to viral and respiratory-related pathologies were measured in the serum of COVID-19-negative controls (n = 16), IgG-positive COVID-19 asymptomatic individuals (n = 16), and critical COVID-19 patients (n = 17). Four of the peripheral microRNAs analyzed (hsa-miR-32-5p, hsa-miR-98-3p, hsa-miR-423-3p, and hsa-miR-1246) were upregulated in COVID-19 critical patients compared with COVID-19-negative controls. Moreover, hsa-miR-32-5p and hsa-miR-1246 levels were also altered in critical versus asymptomatic individuals. Furthermore, these microRNA target genes were related to viral infection, inflammatory response, and coagulation-related processes. In conclusion, SARS-CoV-2 promotes the alteration of microRNAs targeting the expression of key proteins for viral entry and replication, and these changes are associated with disease severity. The microRNAs identified could be taken as potential biomarkers of COVID-19 progression as well as candidates for future therapeutic approaches against this disease.

Biological underpinnings of sex differences in neurological disorders

The importance of sex differences in neurological disorders has been increasingly acknowledged in recent clinical and basic research studies, but the complex biology and genetics underlying sex-linked biological heterogeneity and its brain-to-body impact remained incompletely understood. Men and women differ substantially in their susceptibility to certain neurological diseases, in the severity of symptoms, prognosis as well as the nature and efficacy of their response to treatments. The detailed mechanisms underlying these differences, especially at the molecular level, are being addressed in many studies but leave a lot to be further revealed. Here, we provide an overview of recent advances in our understanding of how sex differences in the brain and brain-body signaling contribute to neurological disorders and further present some future prospects entailed in terms of diagnostics and therapeutics.

Differential Effects of APOE Genotype on MicroRNA Cargo of Cerebrospinal Fluid Extracellular Vesicles in Females With Alzheimer's Disease Compared to Males

Multiple biological factors, including age, sex, and genetics, influence Alzheimer's disease (AD) risk. Of the 6.2 million Americans living with Alzheimer's dementia in 2021, 3.8 million are women and 2.4 million are men. The strongest genetic risk factor for sporadic AD is apolipoprotein E-e4 (APOE-e4). Female APOE-e4 carriers develop AD more frequently than age-matched males and have more brain atrophy and memory loss. Consequently, biomarkers that are sensitive to biological risk factors may improve AD diagnostics and may provide insight into underlying mechanistic changes that could drive disease progression. Here, we have assessed the effects of sex and APOE-e4 on the miRNA cargo of cerebrospinal fluid (CSF) extracellular vesicles (EVs) in AD. We used ultrafiltration (UF) combined with size exclusion chromatography (SEC) to enrich CSF EVs (e.g., Flotillin+). CSF EVs were isolated from female and male AD or controls (CTLs) that were either APOE-e3,4 or -e3,3 positive (n = 7/group, 56 total). MiRNA expression levels were quantified using a custom TaqMan™ array that assayed 190 miRNAs previously found in CSF, including 25 miRNAs that we previously validated as candidate AD biomarkers. We identified changes in the EV miRNA cargo that were affected by both AD and sex. In total, four miRNAs (miR-16-5p, -331-3p, -409-3p, and -454-3p) were significantly increased in AD vs. CTL, independent of sex and APOE-e4 status. Pathway analysis of the predicted gene targets of these four miRNAs with identified pathways was highly relevant to neurodegeneration (e.g., senescence and autophagy). There were also three miRNAs (miR-146b-5p, -150-5p, and -342-3p) that were significantly increased in females vs. males, independent of disease state and APOE-e4 status. We then performed a statistical analysis to assess the effect of APOE genotype in AD within each sex and found that APOE-e4 status affects different subsets of CSF EV miRNAs in females vs. males. Together, this study demonstrates the complexity of the biological factors associated with AD risk and the impact on EV miRNAs, which may contribute to AD pathophysiology.

Circulating miRNAs Are Associated with Inflammation Biomarkers in Children with Overweight and Obesity: Results of the I.Family Study

Increasing data suggest that overnutrition-induced obesity may trigger an inflammatory process in adipose tissue and upturn in the innate immune system. Numerous players have been involved in governing the inflammatory response, including epigenetics. Among epigenetic players, miRNAs are emerging as crucial regulators of immune cell development, immune responses, autoimmunity, and inflammation. In this study, we aimed at identifying the involvement of candidate miRNAs in relation to inflammation-associated biomarkers in a subsample of European children with overweight and obesity participating in the I.Family study. The study sample included individuals with increased adiposity since this condition contributes to the early occurrence of chronic low-grade inflammation. We focused on the acute-phase reagent C-reactive protein (CRP) as the primary outcome and selected cytokines as plausible biomarkers of inflammation. We found that chronic low-grade CRP elevation shows a highly significant association with miR-26b-3p and hsa-miR-576-5p in boys. Furthermore, the association of CRP with hsa-miR-10b-5p and hsa-miR-31-5p is highly significant in girls. We also observed major sex-related associations of candidate miRNAs with selected cytokines. Except for IL-6, a significant association of hsa-miR-26b-3p and hsa-miR-576-5p with TNF-α, IL1-Ra, IL-8, and IL-15 levels was found exclusively in boys. The findings of this exploratory study suggest sex differences in the association of circulating miRNAs with inflammatory response biomarkers, and indicate a possible role of miRNAs among the candidate epigenetic mechanisms related to the process of low-grade inflammation in childhood obesity.

Metabolic Syndrome: Updates on Pathophysiology and Management in 2021

Metabolic syndrome (MetS) forms a cluster of metabolic dysregulations including insulin resistance, atherogenic dyslipidemia, central obesity, and hypertension. The pathogenesis of MetS encompasses multiple genetic and acquired entities that fall under the umbrella of insulin resistance and chronic low-grade inflammation. If left untreated, MetS is significantly associated with an increased risk of developing diabetes and cardiovascular diseases (CVDs). Given that CVDs constitute by far the leading cause of morbidity and mortality worldwide, it has become essential to investigate the role played by MetS in this context to reduce the heavy burden of the disease. As such, and while MetS relatively constitutes a novel clinical entity, the extent of research about the disease has been exponentially growing in the past few decades. However, many aspects of this clinical entity are still not completely understood, and many questions remain unanswered to date. In this review, we provide a historical background and highlight the epidemiology of MetS. We also discuss the current and latest knowledge about the histopathology and pathophysiology of the disease. Finally, we summarize the most recent updates about the management and the prevention of this clinical syndrome.

Circulating miRNA as potential biomarkers for diabetes mellitus type 2: should we focus on searching for sex differences?

microRNAs are non-coding molecules, approximately 22 nucleotides in length, that regulate various cellular processes. A growing body of evidence has suggested that their dysregulated expression is involved in the pathogenesis of diverse diseases, including diabetes mellitus type 2 (DM2). Early onset of this chronic and complex metabolic disorder is frequently undiagnosed, leading to the development of severe diabetic complications. Notably, DM2 prevalence is rising globally and an increasing number of articles demonstrate that DM2 susceptibility, development, and progression differ between males and females. Therefore, this paper discusses the role of microRNAs as a source of novel diagnostic biomarkers for DM2 and aims to underline the importance of sex disparity in biomarkers research. Taking into account an urgent need for the development of sex-specific diagnostic strategies in DM2, recent results have shown that circulating miRNAs are promising candidates for sex-biased biomarkers.

Temporal brain microRNA expression changes in a mouse model of neonatal hypoxic-ischemic injury

BACKGROUND

Neonatal hypoxic-ischemic brain injury (HIBI) results in significant morbidity and mortality despite current standard therapies. MicroRNAs (miRNAs) are a promising therapeutic target; however, there is a paucity of data on endogenous miRNA expression of the brain after HIBI during the primary therapeutic window (6-72 h after injury).

METHODS

Postnatal day 9 mouse pups underwent unilateral carotid ligation+hypoxia (HIBI), sham surgery+hypoxia, or sham surgery+normoxia (controls). miRNA sequencing was performed on the ipsilateral brain of each of the three groups plus the contralateral HIBI brain at 24 and 72 h after injury. Findings were validated in eight key miRNAs by quantitative polymerase chain reaction.

RESULTS

Hypoxia resulted in significant differential expression of 38 miRNAs at both time points. Mir-2137, -335, -137, and -376c were significantly altered by neonatal HIBI at 24 and 72 h, with 3 of the 4 demonstrating multiphasic expression (different direction of differential expression at 24 versus 72 h).

CONCLUSIONS

Our global assessment of subacute changes in brain miRNA expression after hypoxia or HIBI will advance research into targeted miRNA-based interventions. It will be important to consider the multiphasic miRNA expression patterns after HIBI to identify optimal timing for individual interventions.

IMPACT

This study is the first to comprehensively define endogenous brain microRNA expression changes outside of the first hours after neonatal hypoxic-ischemic brain injury (HIBI). Mir-2137, -335, -137, and -376c were significantly altered by neonatal HIBI and therefore deserve further investigation as possible therapeutic targets. The expression profiles described will support the design of future studies attempting to develop miRNA-based interventions for infants with HIBI. At 24 h after injury, contralateral HIBI miRNA expression patterns were more similar to ipsilateral HIBI than to controls, suggesting that the contralateral brain is not an appropriate "internal control" for miRNA studies in this model.

Diagnostic and prognostic potential of eight whole blood microRNAs for equine sarcoid disease

MicroRNAs have been proposed as biomarkers for equine sarcoids, the most prevalent equine skin tumors globally. This study served to validate the diagnostic and prognostic potential of whole blood microRNAs identified in a previous study for long-term equine sarcoid diagnosis and outcome prediction. Based on findings of a clinical examination at the age of 3 years and a follow-up following a further 5–12 years, 32 Franches-Montagnes and 45 Swiss Warmblood horses were assigned to four groups: horses with regression (n = 19), progression (n = 9), new occurrences of sarcoid lesions (n = 19) and tumor-free control horses (n = 30). The expression levels for eight microRNAs (eca-miR-127, eca-miR-432, eca-miR-24, eca-miR-125a-5p, eca-miR-134, eca-miR-379, eca-miR-381, eca-miR-382) were analyzed through reverse transcription quantitative polymerase chain reaction in whole blood samples collected on initial examination. Associations of sex, breed, diagnosis, and prognosis with microRNA expression levels were examined using multivariable analysis of variance. Sex and breed influenced the expression level of five and two microRNAs, respectively. Eca-miR-127 allowed discrimination between sarcoid-affected and tumor-free horses. No variation in microRNA expression was found when comparing horses with sarcoid regression and progression. Expression levels of eca-miR-125a-5p and eca-miR-432 varied in male horses that developed sarcoids throughout the study period in comparison to male control horses. While none of the investigated miRNAs was validated for predicting the prognosis of sarcoid regression / progression within young horses with this condition, two miRNAs demonstrated potential to predict if young male (though not female) tumor-free horse can develop sarcoids within the following years. Sex- and breed- biased miRNAs exist within the equine species and have an impact on biomarker discovery.

Matters of the heart: Cellular sex differences

Nearly all cardiovascular diseases show sexual dimorphisms in prevalence, presentation, and outcomes. Until recently, most clinical trials were carried out in males, and many animal studies either failed to identify the sex of the animals or combined data obtained from males and females. Cellular sex in the heart is relatively understudied and many studies fail to report the sex of the cells used for in vitro experiments. Moreover, in the small number of studies in which sex is reported, most of those studies use male cells. The observation that cells from males and females are inherently different is becoming increasingly clear - either due to acquired differences from hormones and other factors or due to intrinsic differences in genotype (XX or XY). Because of the likely contribution of cellular sex differences in cardiac health and disease, here, we explore differences in mammalian male and female cells in the heart, including the less-studied non-myocyte cell populations. We discuss how the heart's microenvironment impacts male and female cellular phenotypes and vice versa, including how secretory profiles are dependent on cellular sex, and how hormones contribute to sexually dimorphic phenotypes and cellular functions. Intracellular mechanisms that contribute to sex differences, including gene expression and epigenetic remodeling, are also described. Recent single-cell sequencing studies have revealed unexpected sex differences in the composition of cell types in the heart which we discuss. Finally, future recommendations for considering cellular sex differences in the design of bioengineered in vitro disease models of the heart are provided.

Identification and Characterization of Circulating MicroRNAs as Novel Biomarkers in Dogs With Heart Diseases

Background: Previous studies in humans have confirmed dysregulations of circulating microRNAs (miRNAs) in patients with various cardiovascular diseases. However, studies on circulating miRNAs in dogs with various heart diseases are limited in number. This study aimed to identify significantly dysregulated circulating miRNAs and characterize them as novel biomarkers in dogs with heart diseases. Materials and Methods: Circulating levels of 11 miRNAs were investigated in serum samples of 82 dogs (72 with heart diseases and 10 healthy dogs) using quantitative reverse transcription-polymerase chain reaction. The results were correlated to clinical data including echocardiographic results and N-terminal pro B-type natriuretic peptide (NT-proBNP) levels. Results: Upregulation of cfa-miR-130b was observed in dogs with myxomatous mitral valve degeneration (MMVD) stage B, patent ductus arteriosus, and pulmonic stenosis. In dogs with MMVD stage B, cfa-miR-130b was upregulated and correlated with clinical indices. In receiver operating characteristic (ROC) analysis, cfa-miR-130b accurately distinguished dogs with diseases from healthy dogs. We also observed that cfa-miR-375 and cfa-let-7b were upregulated in dogs with concentric cardiac hypertrophy. The cfa-miR-375 was correlated with concentric hypertrophy indices and was an accurate indicator of concentric hypertrophy in ROC analysis. Conclusions: The miRNAs identified in this study may be used as novel biomarkers and possible candidates for therapeutic targets in various canine heart diseases.

Changes in PPAR-γ Expression Are Associated with microRNA Profiles during Fetal Programming due to Maternal Overweight and Obesity

BACKGROUND

There has been a global increase in the prevalence of obesity in pregnant women in recent years. Animal studies have shown that intrauterine environment associated with maternal obesity leads to epigenetic changes. However, the effects of epigenetic changes occurring before birth in response to maternal conditions have not been clearly characterized in humans.

OBJECTIVE

The aim of the study was to analyze peroxisome proliferator-activated receptor (PPAR)-γ expression in cell cultures from newborns from mothers with overweight and obesity, in response to in vitro metabolic challenges and their relationship with microRNA profile and cytokine expression. Methods/Study design: The profile of circulating microRNAs from 72 mother-child pairs (including healthy infants born to normal weight [n = 35], overweight [n = 25], and obese [n = 12] mothers) was determined through real-time PCR, and the PPAR-γ expression in peripheral blood mononuclear cell cultures from offspring was analyzed after in vitro challenges.

RESULTS

miR-146a, miR-155, and miR-378a were upregulated in overweight mothers, while miR-378a was upregulated in obese mothers compared to normal weight mothers. In children from overweight mothers, miR-155 and miR-221 were downregulated and miR-146a was upregulated, while offspring of mothers with obesity showed downregulation of miR-155, miR-221, and miR-1301. These microRNAs have direct or indirect relation with PPAR-γ expression. In vitro exposure to high triglyceride and exposure to miR-378a induced a higher expression of PPAR-γ in cells from offspring of mothers with overweight and obesity. In contrast, cells from offspring of mothers with obesity cultured with high glucose concentrations showed PPAR-γ downregulation. IL-1ß, IL-6, and TNF-α expression in cells of offspring of overweight and obese mothers differed from that of offspring of normal weight mothers. Limitation of our study is the small sample size.

CONCLUSION

The blood microRNA profile, and in vitro PPAR-γ and inflammatory cytokine expression in cells of newborn infants are associated with maternal obesity indicating that epigenetic marks may be established during intrauterine development. Key Message: Neonatal microRNA profile is associated with maternal weight. Neonatal microRNA profile is independent of maternal microRNA profile. PPAR-γ expression in newborn cell cultures is affected by maternal weight.

Expression levels of serum circulating microRNAs in pediatric patients with ventricular and supraventricular arrhythmias

PURPOSE

Aberrant expression of various miRNA species has been implicated in numerous cardiac diseases, e.g., heart failure, hypertrophy, conduction disturbances, and arrhythmogenesis. The aim of this study was to determine whether miR-1, miR-133a, and miR-133b can serve as biomarkers in the diagnosis of ventricular (Va) and supraventricular (SVa) arrhythmias in pediatric patients.

MATERIALS AND METHODS

Molecular analysis included 30 patients with SVa or Va (13-17.5 years; 14 boys/16 girls) and 20 non-arrhythmic controls. Arrhythmia was confirmed by 24-h Holter ECG recording. miRNA was extracted from serum using the miRNeasy^R Serum/Plasma Kit. miScript SYBR Green PCR Kit (Qiagen) was used to quantify miRNA expression.

RESULTS

The levels of miR-1 and miR-133a expression were significantly higher in the SVa group than in the controls (p ​= ​0.0327 and p<0.0001, respectively). Additionally, both groups of patients with arrhythmia presented significantly lower expression levels of miR-133b than the controls (p<0.01 for both comparisons). The level of miR-133a expression in the SVa group was significantly higher than in the Va group (p ​= ​0.0124). ROC analysis demonstrated that the expressions of miR-1 and miR-133a could differentiate between the SVa patients and arrhythmia-free controls (AUC ​= ​0.7091, p ​= ​0.07 and AUC ​= ​0.8021, p ​= ​0.007, respectively). Furthermore, the expression of miR-133b was shown to distinguish patients with SVa and Va from the arrhythmia-free controls (AUC ​= ​0.7273, p ​= ​0.07 and AUC ​= ​0.8030, p ​= ​0.04, respectively).

CONCLUSIONS

miR-1, miR-133a, and miR-133b have the potential to become diagnostic biomarkers of arrhythmia in pediatric patients.

Sex Differences in Immunity to Viral Infections

The ongoing COVID-19 pandemic has increased awareness about sex-specific differences in immunity and outcomes following SARS-CoV-2 infection. Strong evidence of a male bias in COVID-19 disease severity is hypothesized to be mediated by sex differential immune responses against SARS-CoV-2. This hypothesis is based on data from other viral infections, including influenza viruses, HIV, hepatitis viruses, and others that have demonstrated sex-specific immunity to viral infections. Although males are more susceptible to most viral infections, females possess immunological features that render them more vulnerable to distinct immune-related disease outcomes. Both sex chromosome complement and related genes as well as sex steroids play important roles in mediating the development of sex differences in immunity to viral infections.

Regulatory Network Analysis in Estradiol-Treated Human Endothelial Cells

Background/Aims: Estrogen has been reported to have beneficial effects on vascular biology through direct actions on endothelium. Together with transcription factors, miRNAs are the major drivers of gene expression and signaling networks. The objective of this study was to identify a comprehensive regulatory network (miRNA–transcription factor–downstream genes) that controls the transcriptomic changes observed in endothelial cells exposed to estradiol. Methods: miRNA/mRNA interactions were assembled using our previous microarray data of human umbilical vein endothelial cells (HUVEC) treated with 17β-estradiol (E2) (1 nmol/L, 24 h). miRNA–mRNA pairings and their associated canonical pathways were determined using Ingenuity Pathway Analysis software. Transcription factors were identified among the miRNA-regulated genes. Transcription factor downstream target genes were predicted by consensus transcription factor binding sites in the promoter region of E2-regulated genes by using JASPAR and TRANSFAC tools in Enrichr software. Results: miRNA–target pairings were filtered by using differentially expressed miRNAs and mRNAs characterized by a regulatory relationship according to miRNA target prediction databases. The analysis identified 588 miRNA–target interactions between 102 miRNAs and 588 targets. Specifically, 63 upregulated miRNAs interacted with 295 downregulated targets, while 39 downregulated miRNAs were paired with 293 upregulated mRNA targets. Functional characterization of miRNA/mRNA association analysis highlighted hypoxia signaling, integrin, ephrin receptor signaling and regulation of actin-based motility by Rho among the canonical pathways regulated by E2 in HUVEC. Transcription factors and downstream genes analysis revealed eight networks, including those mediated by JUN and REPIN1, which are associated with cadherin binding and cell adhesion molecule binding pathways. Conclusion: This study identifies regulatory networks obtained by integrative microarray analysis and provides additional insights into the way estradiol could regulate endothelial function in human endothelial cells.

PlasmiR: A Manual Collection of Circulating microRNAs of Prognostic and Diagnostic Value

Only recently, microRNAs (miRNAs) were found to exist in traceable and distinctive amounts in the human circulatory system, bringing forth the intriguing possibility of using them as minimally invasive biomarkers. miRNAs are short non-coding RNAs that act as potent post-transcriptional regulators of gene expression. Extensive studies in cancer and other disease landscapes investigate the protective/pathogenic functions of dysregulated miRNAs, as well as their biomarker potential. A specialized resource amassing experimentally verified, circulating miRNA biomarkers does not exist. We queried the existing literature to identify articles assessing diagnostic/prognostic roles of miRNAs in blood, serum, or plasma samples. Articles were scrutinized in order to exclude instances lacking sufficient experimental documentation or employing no biomarker assessment methods. We incorporated information from more than 200 biomedical articles, annotating crucial meta-information including cohort sizes, inclusion-exclusion criteria, disease/healthy confirmation methods and quantification details. miRNAs and diseases were systematically characterized using reference resources. Our circulating miRNA biomarker collection is provided as an online database, plasmiR. It consists of 1021 entries regarding 251 miRNAs and 112 diseases. More than half of plasmiR's entries refer to cancerous and neoplastic conditions, 183 of them (32%) describing prognostic associations. plasmiR facilitates smart queries, emphasizing visualization and exploratory modes for all researchers.

Expression levels of specific microRNAs are increased after exercise and are associated with cognitive improvement in Parkinson's disease

There is a consensus regarding the efficacy of physical exercise in maintaining or improving human health; however, there are few studies examining the effect of physical exercise on the expression levels of microRNAs (miRNA/miRs) in Parkinson's disease (PD). The aim of the present study was to investigate the effects of an interval training program on a cycle ergometer on the expression levels of miR‑106a‑5p, miR‑103a‑3p and miR‑29a‑3p in serum samples from men with PD. This was a quasi‑experimental study with pre‑ and post‑testing and with a non‑equivalent group design. The participants were selected based on the eligibility criteria and subsequently classified into two groups: Experimental group and control group. The evaluations were performed at the beginning of the study (week 0) and after 8 weeks of the intervention program (week 9). The interval training program was performed on a cycle ergometer for 30 min, three times a week during an 8‑week period. The expression levels of miR‑106a‑5p, miR‑103a‑3p and miR‑29a‑3p in the experimental group were increased after physical exercise and were associated with cognitive improvement in men with PD. However, further studies are required to clarify the potential use of these circulating miRNAs as markers of adaptation to physical exercise. Collectively, the present results indicated that these three miRNAs may be associated with the exercise response and cognitive improvement in men with PD.

The Effects of Biological Sex on Sepsis Treatments in Animal Models: A Systematic Review and a Narrative Elaboration on Sex- and Gender-Dependent Differences in Sepsis

Preclinical studies provide an opportunity to evaluate the relationship between sex and sepsis, and investigate underlying mechanisms in a controlled experimental environment. The objective of our systematic review was to assess the impact of biological sex on treatment response to fluid and antibiotic therapy in animal models of sepsis. Furthermore, we provide a narrative elaboration of sex-dependent differences in preclinical models of sepsis.

DATA SOURCES

MEDLINE and Embase were searched from inception to March 16, 2020.

STUDY SELECTION

All studies reporting sex-stratified data comparing antibiotics and/or fluid resuscitation with a placebo or no treatment arm in an in vivo model of sepsis were included.

DATA EXTRACTION

Outcomes of interest were mortality (primary) and organ dysfunction (secondary). Risk of bias was assessed. Study selection and data extraction were conducted independently and in duplicate.

DATA SYNTHESIS

The systematic search returned 2,649 unique studies, and two met inclusion criteria. Both studies used cecal ligation and puncture models with imipenem/cilastatin antibiotics. No eligible studies investigated fluids. In one study, antibiotic therapy significantly reduced mortality in male, but not female, animals. The other study reported no sex differences in organ dysfunction. Both studies were deemed to be at a high overall risk of bias.

CONCLUSIONS

There is a remarkable and concerning paucity of data investigating sex-dependent differences in fluid and antibiotic therapy for the treatment of sepsis in animal models. This may reflect poor awareness of the importance of investigating sex-dependent differences. Our discussion therefore expands on general concepts of sex and gender in biomedical research and sex-dependent differences in key areas of sepsis research such as the cardiovascular system, immunometabolism, the microbiome, and epigenetics. Finally, we discuss current clinical knowledge, the potential for reverse translation, and directions for future studies.

REGISTRATION

PROSPERO CRD42020192738.

Circulating MicroRNA Responses to Postprandial Lipemia with or without Prior Exercise

Repeated exposure to a high-fat meal triggers inflammation and oxidative stress, contributing to the onset of cardiometabolic diseases. Regular exercise prevents cardiometabolic diseases and a prior bout of acute endurance exercise can counteract the detrimental cardiovascular effects of a subsequent high-fat meal. Circulating microRNAs (ci-miRs) are potential mediators of these vascular effects through regulation of gene expression at the posttranscriptional level. Therefore, we investigated the expression of ci-miRs related to vascular function (miR-21, miR-92a, miR-126, miR-146a, miR-150, miR-155, miR-181b, miR-221, miR-222) in plasma from healthy, recreationally to highly active, Caucasian adult men after a high-fat meal with (EX) and without (CON) a preceding bout of cycling exercise. Ci-miR-155 was the only ci-miR for which there was a significant interaction effect of high-fat meal and exercise (p=0.050). Ci-miR-155 significantly increased in the CON group at two (p=0.007) and four hours (p=0.010) after the high-fat meal test, whereas it significantly increased in the EX group only four hours after the meal (p=0.0004). There were significant main effects of the high-fat meal on ci-miR-21 (p=0.01), ci-miR-126 (p=0.02), ci-miR-146a (p=0.02), ci-miR-181b (p=0.02), and ci-miR-221 (p=0.008). Collectively, our results suggest that prior exercise does not prevent high-fat meal-induced increases in vascular-related ci-miRs.