Serum Profile of microRNAs Linked to Bone Metabolism During Sequential Treatment for Postmenopausal Osteoporosis

Bone marrow-fibroblast progenitor cell-derived small extracellular vesicles promote cardiac fibrosis via miR-21-5p and integrin subunit αV signalling

Cardiac fibrosis is the hallmark of cardiovascular disease (CVD), which is leading cause of death worldwide. Previously, we have shown that interleukin-10 (IL10) reduces pressure overload (PO)-induced cardiac fibrosis by inhibiting the recruitment of bone marrow fibroblast progenitor cells (FPCs) to the heart. However, the precise mechanism of FPC involvement in cardiac fibrosis remains unclear. Recently, exosomes and small extracellular vesicles (sEVs) have been linked to CVD progression. Thus, we hypothesized that pro-fibrotic miRNAs enriched in sEV-derived from IL10 KO FPCs promote cardiac fibrosis in pressure-overloaded myocardium. Small EVs were isolated from FPCs cultured media and characterized as per MISEV-2018 guidelines. Small EV's miRNA profiling was performed using Qiagen fibrosis-associated miRNA profiler kit. For functional analysis, sEVs were injected in the heart following TAC surgery. Interestingly, TGFβ-treated IL10-KO-FPCs sEV increased profibrotic genes expression in cardiac fibroblasts. The exosomal miRNA profiling identified miR-21a-5p as the key player, and its inhibition with antagomir prevented profibrotic signalling and fibrosis. At mechanistic level, miR-21a-5p binds and stabilizes ITGAV (integrin av) mRNA. Finally, miR-21a-5p-silenced in sEV reduced PO-induced cardiac fibrosis and improved cardiac function. Our study elucidates the mechanism by which inflammatory FPC-derived sEV exacerbate cardiac fibrosis through the miR-21a-5p/ITGAV/Col1α signalling pathway, suggesting miR-21a-5p as a potential therapeutic target for treating hypertrophic cardiac remodelling and heart failure.

Micro-RNA: A Future Approach to Personalized Diagnosis of Bone Diseases

Osteoporosis is a highly prevalent bone disease worldwide and the most studied bone-associated pathological condition. Although its diagnosis makes use of advanced and clinically relevant imaging and biochemical tools, the information suffers from several limitations and has little or no prognostic value. In this context, circulating micro-RNAs represent a potentially attractive alternative or a useful addition to the diagnostic arsenal and offer a greater prognostic potential than the conventional approaches. These short non-coding RNA molecules act as inhibitors of gene expression by targeting messenger RNAs with different degrees of complementarity, establishing a complex multilevel network, the basis for the fine modulation of gene expression that finally regulates every single activity of a cell. Micro-RNAs may passively and/or actively be released in the circulation by source cells, and being measurable in biological fluids, their concentrations may be associated to specific pathophysiological conditions. Mounting, despite debatable, evidence supports the use of micro-RNAs as markers of bone cell metabolic activity and bone diseases. Indeed, several micro-RNAs have been associated with bone mineral density, fractures and osteoporosis. However, concerns such as absence of comparability between studies and, the lack of standardization and harmonization of the methods, limit their application. In this review, we describe the pathophysiological bases of the association between micro-RNAs and the deregulation of bone cells activity and the processes that led to the identification of potential micro-RNA-based markers associated with metabolic bone diseases.

Circulating miRNAs Respond to Denosumab Treatment after Two Years in Postmenopausal Women with Osteoporosis

CONTEXT

MicroRNAs (miRNAs) are short, single-stranded, non-coding RNAs which regulate gene expression. They originate from various tissues including bone and regulate different biological mechanisms including bone metabolism.

OBJECTIVE

The aim of this project was to investigate circulating miRNAs as promising biomarkers for treatment monitoring in women with postmenopausal osteoporosis on denosumab (DMAB) therapy.

DESIGN, SETTING AND PATIENTS

In this prospective, observational, single-centre study twenty-one postmenopausal women treated with DMAB were included for a longitudinal follow-up of two years.

INTERVENTIONS AND MAIN OUTCOME MEASURES

Next-generation sequencing (NGS) was performed to screen for serological miRNAs at defined time points (baseline, month 6 and month 24). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was used to confirm NGS findings in the entire cohort. Bone turnover markers (BTM) P1NP and CTX, and bone mineral density (BMD) by Dual X-Ray absorptiometry (DXA) were assessed and correlated to miRNAs.

RESULTS

BMD at the hip (5,5%, p = 0.0006) and lumbar spine significantly increased (11,4%, p-value = 0.017) and CTX (64,1%, p < 0.0001) and P1NP (69,3%, p < 0.0001) significantly decreased during treatment. NGS analysis revealed significant changes in miRNAs after 2-years of DMAB treatment, but not after 6-months. Seven miRNAs were confirmed by RT-qPCR to be significantly changed during a 2-year course of DMAB treatment compared to baseline. Four of these were found to be mainly transcribed in blood cells including monocytes. Correlation analysis identified a significant correlation between change in miRNA and change in BTMs as well as BMD. Based on effect size and correlation strength, miR-454-3p, miR-26b-5p and miR-584-5p were defined as top biomarker candidates with the strongest association to the sustained effect of denosumab on bone in osteoporotic patients.

CONCLUSIONS

Two years of DMAB-treatment resulted in the upregulation of 7 miRNAs, four of which are mainly transcribed in monocytes indicating a potential impact of DMAB on circulating osteoclast precursor cells. These changes were associated to BMD gain and BTM suppression and could therefore be useful for monitoring DMAB-treatment response.

Bone-Metabolism-Related Serum microRNAs to Diagnose Osteoporosis in Middle-Aged and Elderly Women

Objective: Postmenopausal osteoporosis (PMOP), a chronic systemic metabolic disease prevalent in middle-aged and elderly women, heavily relies on bone mineral density (BMD) measurement as the diagnostic indicator. In this study, we investigated serum microRNAs (miRNAs) as a possible screening tool for PMOP. Methods: This investigation recruited 83 eligible participants from 795 community-dwelling postmenopausal women between June 2020 and August 2021. The miRNA expression profiles in the serum of PMOP patients were evaluated via miRNA microarray (six PMOP patients and four postmenopausal women without osteoporosis (n-PMOP) as controls). Subsequently, results were verified in independent sample sets (47 PMOP patients and 26 n-PMOP controls) using quantitative real-time PCR. In addition, the target genes and main functions of the differentially expressed miRNAs were explored by bioinformatics analysis. Results: Four highly expressed miRNAs in the serum of patients (hsa-miR-144-5p, hsa-miR-506-3p, hsa-miR-8068, and hsa-miR-6851-3p) showed acceptable disease-independent discrimination performance (area under the curve range: 0.747-0.902) in the training set and verification set, outperforming traditional bone turnover markers. Among four key miRNAs, hsa-miR-144-5p is the only one that can simultaneously predict changes in BMD in lumbar spine 1-4, total hip, and femoral neck (β = -0.265, p = 0.022; β = -0.301, p = 0.005; and β = -0.324, p = 0.003, respectively). Bioinformatics analysis suggested that the differentially expressed miRNAs were targeted mainly to YY1, VIM, and YWHAE genes, which are extensively involved in bone metabolism processes. Conclusions: Bone-metabolism-related serum miRNAs, such as hsa-miR-144-5p, hsa-miR-506-3p, hsa-miR-8068, and hsa-miR-6851-3p, can be used as novel biomarkers for PMOP diagnosis independent of radiological findings and traditional bone turnover markers. Further study of these miRNAs and their target genes may provide new insights into the epigenetic regulatory mechanisms of the onset and progression of the disease.

Interactome of PTH-Regulated miRNAs and Their Predicted Target Genes for Investigating the Epigenetic Effects of PTH (1-34) in Bone Metabolism

Osteoporosis is a metabolic bone disease that mostly affects the elderly. A lot of drugs are available, mostly with an antiresorptive effect but just a few with an osteoanabolic effect, meaning they promote bone building. PTH (1-34) or teriparatide is an osteoanabolic drug, but its efficacy varies between individuals. We performed a literature review and extracted a dataset of 62 microRNAs (miRNAs) from 10 different studies; predicted miRNA target interactions (MTIs) were obtained with the help of four software tools: DIANA, miRWalk, miRDB and TargetScan. With the construction of an interactome of PTH-regulated miRNAs and their predicted target genes, we elucidated miR-146a-5p, miR-551b-5p, miR-205-3p, miR-33a-3p, miR-338-5p as miRNAs with the most interactions and miR-410-3p as the miRNA targeting bone-related pathways with the highest significance. These miRNAs could help in further understanding the mechanism of action of PTH on bone metabolism and osteoporosis. They also have the potential for novel network-based biomarkers for osteoporosis treatment efficacy and safety and as new therapeutic targets.

The effect of pharmacological cessation and restoration of menstrual cycle on bone metabolism in premenopausal women with endometriosis

INTRODUCTION

GnRH-analogs induce bone loss. We aimed to investigate the effects of goserelin-induced menstrual cessation (MC) and subsequent menstrual restoration (MR) on bone metabolism (BM).

METHODS

In this prospective cohort study, premenopausal women (PMW) with histologically verified endometriosis (n = 21) received goserelin monthly for 6 months (6 m) resulting in MC and were followed up for another 6 m after MR (12 m). Age- and BMI-matched healthy PMW (n = 20) served as controls for bone mineral density (BMD) measurements. The primary endpoint was changes in lumbar spine (LS)-BMD at 6 m and 12 m; Secondary endpoints were changes in femoral neck (FN)-BMD, bone turnover markers (P1NP and CΤx), sclerostin, and expression of bone-related circulating microRNAs (miRNAs) at 6 m and 12 m.

RESULTS

Goserelin-induced MC reduced LS- and FN-BMD at 6 m (both p < 0.001). From 6 m to 12 m, LS-BMD increased (p < 0.001) but remained below baseline values (p = 0.012), whereas FN-BMD remained stable (p = 1.000). CTx and P1NP levels increased at 6 m (both p < 0.001) and decreased at 12 m (p < 0.001 and p = 0.013, respectively), while CTx (p = 1.000) alone and not P1NP (p = 0.020) returned to baseline. Sclerostin levels did not change. Relative expression of miRNAs targeting RUNX 2 and beta-catenin was significantly downregulated at 6 m compared to baseline (p < 0.001), while the expression of miRNAs targeting osteoblast and osteoclast function at both directions demonstrated a robust increase (up to 400fold) at 12 m (p < 0.001).

CONCLUSIONS

Six months of goserelin-induced MC lead to significant bone loss associated with increased bone turnover and changes in the expression of bone-related miRNAs, changes that are only partially reversed at 6 m after MR.

Roles of MicroRNAs in Osteogenesis or Adipogenesis Differentiation of Bone Marrow Stromal Progenitor Cells

Bone marrow stromal cells (BMSCs) are multipotent cells which can differentiate into chondrocytes, osteoblasts, and fat cells. Under pathological stress, reduced bone formation in favour of fat formation in the bone marrow has been observed through a switch in the differentiation of BMSCs. The bone/fat switch causes bone growth defects and disordered bone metabolism in bone marrow, for which the mechanisms remain unclear, and treatments are lacking. Studies suggest that small non-coding RNAs (microRNAs) could participate in regulating BMSC differentiation by disrupting the post-transcription of target genes, leading to bone/fat formation changes. This review presents an emerging concept of microRNA regulation in the bone/fat formation switch in bone marrow, the evidence for which is assembled mainly from in vivo and in vitro human or animal models. Characterization of changes to microRNAs reveals novel networks that mediate signalling and factors in regulating bone/fat switch and homeostasis. Recent advances in our understanding of microRNAs in their control in BMSC differentiation have provided valuable insights into underlying mechanisms and may have significant potential in development of new therapeutics.

Longitudinal Changes of Circulating miRNAs During Bisphosphonate and Teriparatide Treatment in an Animal Model of Postmenopausal Osteoporosis

MicroRNAs regulate bone homeostasis, and circulating microRNAs have been proposed as novel bone biomarkers. The effect of anti-osteoporotic treatment on circulating microRNAs has not been described in detail. Therefore, we performed a comprehensive analysis of microRNA serum levels in ovariectomized (OVX) and sham-operated (SHAM) rats over 12 weeks of antiresorptive or osteoanabolic treatment. Forty-two Sprague Dawley rats underwent SHAM surgery (n = 10) or ovariectomy (n = 32). After 8 weeks, OVX rats were randomized to antiresorptive treatment with zoledronate (n = 11), osteoanabolic treatment with teriparatide (n = 11), or vehicle treatment (n = 10). Serum samples were collected at weeks 8, 12, 16, and 20 after surgery. A total of 91 microRNAs were analyzed by RT-qPCR in serum samples collected at week 20. Based on the results, 29 microRNAs were selected for longitudinal analysis at all four study time points. Changes in bone mineral density and microstructure were followed up by in vivo micro-CT and ex vivo nano-CT. Ovariectomy resulted in the loss of trabecular bone, which was reversed by osteoanabolic and antiresorptive treatment. Differential expression analysis identified 11 circulating miRNAs that were significantly regulated after treatment. For example, miR-107 and miR-31-5p increased in vehicle-treated OVX animals, whereas they decreased during teriparatide treatment. Additional miRNAs were identified that showed significant correlations to bone microstructure or bone miRNA expression, including miR-203a-3p, which exhibited a significant negative correlation to vertebral and tibial trabecular bone volume fraction (%). Longitudinal analysis confirmed eight microRNAs with significant changes in serum over time that were prevented by teriparatide and zoledronate treatment (miR-34a-5p, miR-31-5p, miR-30d-3p, miR-378a-5p) or teriparatide treatment only (miR-375-3p, miR-183-5p, miR-203a-3p, miR-203b-3p). Gene target network analysis identified WNT and Notch signaling as the main signaling pathways controlled by these miRNAs. Thus, ovariectomy results in time-dependent deregulation of circulating miRNAs compared with SHAM animals. Anti-osteoporotic treatments can rescue this effect, showing that bone-related miRNAs might act as novel biomarkers for treatment monitoring. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Circulating microRNAs Related to Bone Metabolism in HIV-Associated Bone Loss

The pathophysiology of human immunodeficiency virus (HIV)-associated bone loss is complex and to date largely unknown. In this study, we investigated serum expression of microRNAS (miRNAs) linked to bone metabolism in HIV-associated bone loss. This was a case-control study. Thirty male individuals with HIV infection (HIV+) and osteoporosis/osteopenia (HIV+/OP+) (cases) and 30 age-matched male HIV+ individuals with normal bone mass (HIV+/OP-) (controls) were included in the analysis. Thirty male individuals matched for age without HIV infection (HIV-), were also included as second controls. The selected panel of miRNAs was as follows: hsa-miRNA-21-5p; hsa-miRNA-23a-3p; hsa-miRNA-24-2-5p; hsa-miRNA-26a-5p; hsa-miRNA-29a-3p; hsa-miRNA-124-3p; hsa-miRNA-33a-5p; and hsa-miRNA-133a-3p. Within the cohort of HIV+ individuals, relative serum expression of miRNA-21-5p and miRNA-23a-3p was significantly lower (p < 0.001) while the expression of miRNA-24-2-5p was significantly higher (p = 0.030) in HIV+/OP+ compared to HIV+/OP-. Expression of miRNA-21-5p demonstrated a sensitivity of 84.6% and a specificity of 66.7 in distinguishing HIV+/OP+ individuals. Expression of circulating miRNAs related to bone metabolism; miRNA-23a-3p, miRNA-24-2-5p, and miRNA-21-5p is significantly altered in HIV+OP+ individuals, in line with data on other causes of osteoporosis, suggesting a common pattern of circulating miRNAs independent of the underlying cause.

Expression of Circulating MicroRNAs Linked to Bone Metabolism in Chronic Kidney Disease-Mineral and Bone Disorder

The pathophysiology of chronic kidney disease-mineral and bone disorder (CKD-MBD) is complex and multifactorial. Recent studies have identified a link between microRNAs (miRNAs) and bone loss. In this study, we investigated the expression of miRNAs in CKD-MBD. In this case-control study, we included thirty patients with CKD-MBD (cases) and 30 age- and gender-matched healthy individuals (controls). Bone mineral density (BMD) and trabecular bone score (TBS) evaluation was performed with dual X-ray absorptiometry. The selected panel of miRNAs included: hsa-miRNA-21-5p; hsa-miRNA-23a-3p; hsa-miRNA-24-2-5p; hsa-miRNA-26a-5p; hsa-miRNA-29a-3; hsa-miRNA-124-3p; hsa-miRNA-2861. The majority of cases had low BMD values. The relative expression of miRNA-21-5p was 15 times lower [fold regulation (FR): -14.7 ± 8.1, p = 0.034), miRNA-124-3p, 6 times lower (FR: -5.9 ± 4, p = 0.005), and miRNA-23a-3p, 4 times lower (FR: -3.8 ± 2.0, p = 0.036) in cases compared to controls. MiRNA-23a-3p was significantly and inversely correlated with TBS, adjusted for calcium metabolism and BMD values (beta = -0.221, p = 0.003, 95% CI -0.360, -0,081) in cases. In a receiver operating characteristic (ROC) analysis, expression of miRNA-124-3p demonstrated 78% sensitivity and 83% specificity in identifying CKD patents with osteoporosis. Serum expression of miRNAs related to osteoblasts (miRNA-23a-3p) and osteoclasts (miRNA-21-5p, miRNA-124-3p) is significantly altered in patients with CKD-MBD.

The Role of Chronic Inflammatory Bone and Joint Disorders in the Pathogenesis and Progression of Alzheimer's Disease

Late-onset Alzheimer's Disease (LOAD) is a devastating neurodegenerative disorder that causes significant cognitive debilitation in tens of millions of patients worldwide. Throughout disease progression, abnormal secretase activity results in the aberrant cleavage and subsequent aggregation of neurotoxic Aβ plaques in the cerebral extracellular space and hyperphosphorylation and destabilization of structural tau proteins surrounding neuronal microtubules. Both pathologies ultimately incite the propagation of a disease-associated subset of microglia-the principle immune cells of the brain-characterized by preferentially pro-inflammatory cytokine secretion and inhibited AD substrate uptake capacity, which further contribute to neuronal degeneration. For decades, chronic neuroinflammation has been identified as one of the cardinal pathophysiological driving features of AD; however, despite a number of works postulating the underlying mechanisms of inflammation-mediated neurodegeneration, its pathogenesis and relation to the inception of cognitive impairment remain obscure. Moreover, the limited clinical success of treatments targeting specific pathological features in the central nervous system (CNS) illustrates the need to investigate alternative, more holistic approaches for ameliorating AD outcomes. Accumulating evidence suggests significant interplay between peripheral immune activity and blood-brain barrier permeability, microglial activation and proliferation, and AD-related cognitive decline. In this work, we review a narrow but significant subset of chronic peripheral inflammatory conditions, describe how these pathologies are associated with the preponderance of neuroinflammation, and posit that we may exploit peripheral immune processes to design interventional, preventative therapies for LOAD. We then provide a comprehensive overview of notable treatment paradigms that have demonstrated considerable merit toward treating these disorders.