Human Circulating miRNAs Real-time qRT-PCR-based Analysis: An Overview of Endogenous Reference Genes Used for Data Normalization

miRNAs are small non-coding RNAs of about 18–25 nucleotides that negatively regulate gene expression at the post-transcriptional level. It was reported that a deregulation of their expression patterns correlates to the onset and progression of various diseases. Recently, these molecules have been identified in a great plethora of biological fluids, and have also been proposed as potential diagnostic and prognostic biomarkers. Actually, real time quantitative polymerase chain reaction is the most widely used approach for circulating miRNAs (c-miRNAs) expression profiling. Nevertheless, the debate on the choice of the most suitable endogenous reference genes for c-miRNAs expression levels normalization is still open. In this regard, numerous research groups are focusing their efforts upon identifying specific, highly stable, endogenous c-mRNAs. The aim of this review is to provide an overview on the reference genes currently used in the study of various pathologies, offering to researchers the opportunity to select the appropriate molecules for c-miRNA levels normalization, when their choosing is based upon literature data

Circulating miRNAs: A New Opportunity in Bone Fragility

Osteoporosis, one of the leading causes of bone fractures, is characterized by low bone mass and structural deterioration of bone tissue, which are associated with a consequent increase in bone fragility and predisposition to fracture. Current screening tools are limited in estimating the proper assessment of fracture risk, highlighting the need to discover novel more suitable biomarkers. Genetic and environmental factors are both implicated in this disease. Increasing evidence suggests that epigenetics and, in particular, miRNAs, may represent a link between these factors and an increase of fracture risk. miRNAs are a class of small noncoding RNAs that negatively regulate gene expression. In the last decade, several miRNAs have been associated with the development of osteoporosis and bone fracture risk, opening up new possibilities in precision medicine. Recently, these molecules have been identified in several biological fluids, and the possible existence of a circulating miRNA (c-miRNA) signature years before the fracture occurrence is suggested. The aim of this review is to provide an overview of the c-miRNAs suggested as promising biomarkers for osteoporosis up until now, which could be helpful for early diagnosis and monitoring of treatment response, as well as fracture risk assessment, in osteoporotic patients

Circulating MicroRNAs as Novel Biomarkers for Osteoporosis and Fragility Fracture Risk: Is There a Use in Assessment Risk?

Osteoporosis is a multifactorial skeletal disease that is associated with both bone mass decline and microstructure damage. The fragility fractures—especially those affecting the femur—that embody the clinical manifestation of this pathology continue to be a great medical and socioeconomic challenge worldwide. The currently available diagnostic tools, such as dual energy X-ray absorptiometry, Fracture Risk Assessment Tool (FRAX) score, and bone turnover markers, show limited specificity and sensitivity; therefore, the identification of alternative approaches is necessary. As a result of their advantageous features, such as non-invasiveness, biofluid stability, and easy detection, circulating cell-free miRs are promising new potential biomarkers for the diagnosis of osteoporosis and low-traumatic fracture risk assessment. However, due to the absence of both standardized pre-analytical, analytical, and post-analytical protocols for their measurement and universally accepted guidelines for diagnostic use, their clinical utility is limited. The aim of this review was to record all the data currently available in the literature concerning the use of circulating microRNAs as both potential biomarkers for osteoporosis diagnosis and fragility fracture risk evaluation, and group them according to the experimental designs, in order to support a more conscious choice of miRs for future research in this field

Subcutaneous adipocytes may become osteoblasts

Commonly, mesenchymal stem cells derived from bone marrow (BMSCs) are mainly utilized in regenerative medicine field. BMSCs are able to differentiate into several lineages, showing immunosuppressive properties, and they are genetically stable in long-term cultures. In the last years, another mesenchymal stem cells population, obtained from adipose tissue, defined adipose-derived stem/stromal cells (ASCs), it is under assessment of scientific research, as alternative to BMSCs. In fact, ASCs show similar capacity to BMSCs, but unlike BMSCs can be harvested more easily with an higher yield and with less invasive manipulation. In this review the abilities of ASCs to differentiate in osteoblasts cells are show

Effect of Oxidative Stress-Induced Apoptosis on Active FGF23 Levels in MLO-Y4 Cells: The Protective Role of 17-β-Estradiol

The discovery that osteocytes secrete phosphaturic fibroblast growth factor 23 (FGF23) has defined bone as an endocrine organ. However, the autocrine and paracrine functions of FGF23 are still unknown. The present study focuses on the cellular and molecular mechanisms involved in the complex control of FGF23 production and local bone remodeling functions. FGF23 was assayed using ELISA kit in the presence or absence of 17β–estradiol in starved MLO-Y4 osteocytes. In these cells, a relationship between oxidative stress-induced apoptosis and up-regulation of active FGF23 levels due to MAP Kinases activation with involvement of the transcriptional factor (NF-kB) has been demonstrated. The active FGF23 increase can be due to up-regulation of its expression and post-transcriptional modifications. 17β–estradiol prevents the increase of FGF23 by inhibiting JNK and NF-kB activation, osteocyte apoptosis and by the down-regulation of osteoclastogenic factors, such as sclerostin. No alteration in the levels of dentin matrix protein 1, a FGF23 negative regulator, has been determined. The results of this study identify biological targets on which drugs and estrogen may act to control active FGF23 levels in oxidative stress-related bone and non-bone inflammatory diseases

Subject, session and task effects on power, connectivity and network centrality: A source-based EEG study

Inter-subjects’ variability in functional brain networks has been extensively investigated in the last fewyears. In this context, unveiling subject-specific characteristics of EEG features may play an importantrole for both clinical (e.g., biomarkers) and bio-engineering purposes (e.g., biometric systems and braincomputer interfaces). Nevertheless, the effects induced by multi-sessions and task-switching are notcompletely understood and considered. In this work, we aimed to investigate how the variability due tosubject, session and task affects EEG power, connectivity and network features estimated using source-reconstructed EEG time-series. Our results point out a remarkable ability to identify stable subject featureswithin a given task together with striking independence from the session. The results also show a relevanteffect of task-switching, which is comparable to individual variability. This study suggests that powerand connectivity EEG features may be adequate to detect stable (over-time) individual properties withinpredefined and controlled tasks and that these findings are consistent over a range of connectivity metrics,different epoch lengths and parcellation schemes.© 202