Circulating Long Non-Coding RNA GAS5 Is Overexpressed in Serum from Osteoporotic Patients and Is Associated with Increased Risk of Bone Fragility

Biofluid-Derived Exosomal LncRNAs: Their Potential in Obesity and Related Comorbidities

Obesity has escalated into a critical global health crisis, tripling in prevalence since the mid-1970s. This increase mirrors the rise in metabolic-associated diseases such as type 2 diabetes (T2D) and its complications, certain cancers, and cardiovascular conditions. While substantial research efforts have enriched our understanding and led to the development of innovative management strategies for these diseases, the suboptimal response rates of existing therapies remain a major obstacle to effectively managing obesity and its associated conditions. Over the years, inter-organ communication (IOC) has emerged as a crucial factor in the development and progression of metabolic disorders. Exosomes, which are nano-sized vesicular couriers released by cells, play a significant role in this communication by transporting proteins, lipids, and nucleic acids across cellular landscapes. The available evidence indicates that exosomal RNAs present in biofluids such as blood, urine, milk, vitreous humor (VH), and cerebrospinal fluid (CSF) are altered in numerous diseases, suggesting their diagnostic and therapeutic potential. Long non-coding RNAs contained in exosomes (exo-lncRNAs) have attracted considerable interest, owing to their ability to interact with critical components involved in a multitude of metabolic pathways. Recent studies have found that alterations in exo-lncRNAs in biofluids correlate with several metabolic parameters in patients with metabolic-associated conditions; however, their exact roles remain largely unclear. This review highlights the diagnostic and therapeutic potential of exosomal lncRNAs in obesity and its associated conditions, emphasizing their role in IOC and disease progression, aiming to pave the way for further research in this promising domain.

Zoledronic Acid Accelerates Bone Healing in Carpal Navicular Fracture via Silencing Long Non-coding RNA Growth Arrest Specificity 5 to Modulate MicroRNA-29a-3p Expression

Carpal navicular fractures are the most common carpal fractures. This study intends to explore the specific mechanism of Zoledronic Acid (ZA) in carpal navicular fracture healing via long non-coding RNA (lncRNA) growth arrest specificity 5 (GAS5) to mediate microRNA (miR)-29a-3p. A fractured rat model was constructed. Two weeks later, a subcutaneous injection of systemic ZA was implemented, and an injection of plasmid vectors interfered with GAS5 or miR-29a-3p expression was performed on the fracture site. Osteocalcin (OCN) and bone morphogenetic protein-2 (BMP-2) were determined, as well as serum levels of alkaline phosphatase (ALP), osteopontin (OPN) and osteoprotegerin (OPG) and bone mineral density. MC3T3-E1 cells were transfected with plasmid vectors interfering with GAS5 or miR-29a-3p, and cell proliferation and apoptosis were analyzed. GAS5 and miR-29a-3p expression in fractured rats was tested, together with their binding relationship. ZA promoted OCN and BMP-2 expression, increased bone mineral density and serum levels of ALP, OPN and OPG in fractured rats. GAS5 was upregulated and miR-29a-3p was down-regulated in fractured rats. Downregulation of GAS5 or upregulation of miR-29a-3p further promoted bone healing in fractured rats. GAS5 targets miR-29a-3p, and down-regulation of miR-29a-3p can reverse the effect of down-regulation of GAS5 on bone healing in fractured rats. ZA promoted the proliferation of MC3T3-E1 cells and inhibited apoptosis by regulating the GAS5/miR-29a-3p axis. ZA regulates miR-29a-3p expression by down-regulating GAS5 to promote carpal navicular fracture healing, promote MC3T3-E1 cell proliferation, and inhibit cell apoptosis.

lncRNA Biomarkers of Glioblastoma Multiforme

Long noncoding RNAs (lncRNAs) are RNA molecules of 200 nucleotides or more in length that are not translated into proteins. Their expression is tissue-specific, with the vast majority involved in the regulation of cellular processes and functions. Many human diseases, including cancer, have been shown to be associated with deregulated lncRNAs, rendering them potential therapeutic targets and biomarkers for differential diagnosis. The expression of lncRNAs in the nervous system varies in different cell types, implicated in mechanisms of neurons and glia, with effects on the development and functioning of the brain. Reports have also shown a link between changes in lncRNA molecules and the etiopathogenesis of brain neoplasia, including glioblastoma multiforme (GBM). GBM is an aggressive variant of brain cancer with an unfavourable prognosis and a median survival of 14-16 months. It is considered a brain-specific disease with the highly invasive malignant cells spreading throughout the neural tissue, impeding the complete resection, and leading to post-surgery recurrences, which are the prime cause of mortality. The early diagnosis of GBM could improve the treatment and extend survival, with the lncRNA profiling of biological fluids promising the detection of neoplastic changes at their initial stages and more effective therapeutic interventions. This review presents a systematic overview of GBM-associated deregulation of lncRNAs with a focus on lncRNA fingerprints in patients' blood.

Discovery of potential biomarkers for osteoporosis diagnosis by individual omics and multi-omics technologies

INTRODUCTION

Global aging has made osteoporosis an increasingly serious public health problem. Osteoporotic fractures seriously affect the quality of life of patients and increase disability and mortality rates. Early diagnosis is important for timely intervention. The continuous development of individual- and multi-omics methods is helpful for the exploration and discovery of biomarkers for the diagnosis of osteoporosis.

AREAS COVERED

In this review, we first introduce the epidemiological status of osteoporosis and then describe the pathogenesis of osteoporosis. Furthermore, the latest progress in individual- and multi-omics technologies for exploring biomarkers for osteoporosis diagnosis is summarized. Moreover, we clarify the advantages and disadvantages of the application of osteoporosis biomarkers obtained using the omics method. Finally, we put forward valuable views on the future research direction of diagnostic biomarkers of osteoporosis.

EXPERT OPINION

Omics methods undoubtedly provide greatly contribute to the exploration of diagnostic biomarkers of osteoporosis; however, in the future, the clinical validity and clinical utility of the obtained potential biomarkers should be thoroughly examined. In addition, the improvement and optimization of the detection methods for different types of biomarkers and standardization of the detection process guarantee the reliability and accuracy of the detection results.

Epigenotoxicity: a danger to the future life

Environmental toxicants can regulate gene expression in the absence of DNA mutations via epigenetic mechanisms such as DNA methylation, histone modifications, and non-coding RNAs' (ncRNAs). Here, all three epigenetic modifications for seven important categories of diseases and the impact of eleven main environmental factors on epigenetic modifications were discussed. Epigenetic-related mechanisms are among the factors that could explain the root cause of a wide range of common diseases. Its overall impression on the development of diseases can help us diagnose and treat diseases, and besides, predict transgenerational and intergenerational effects. This comprehensive article attempted to address the relationship between environmental factors and epigenetic modifications that cause diseases in different categories. The studies main gap is that the precise role of environmentally-induced epigenetic alterations in the etiology of the disorders is unknown; thus, still more well-designed researches need to be accomplished to fill this gap. The present review aimed to first summarize the adverse effect of certain chemicals on the epigenome that may involve in the onset of particular disease based on in vitro and in vivo models. Subsequently, the possible adverse epigenetic changes that can lead to many human diseases were discussed.

The Ifng antisense RNA 1 (IFNG-AS1) and growth arrest-specific transcript 5 (GAS5) are novel diagnostic and prognostic markers involved in childhood ITP

Background/aim:IFNG-AS1 is a long noncoding RNA that works as an enhancer for the Interferon-gamma (IFN-γ) transcript. GAS5 (growth arrest-specific 5) is a lncRNA that is associated with glucocorticoid resistance. Aberrant expressions of IFNG-AS1 and GAS5 are directly linked to numerous autoimmune disorders but their levels in childhood ITP are still obscure. This study aims to elucidate expressions of target lncRNAs in childhood ITP and their association with pathophysiology and clinical features of the disease as well as their association with types and treatment responses.

Method: The fold changes of target lncRNAs in blood samples from children with ITP and healthy controls were analyzed using quantitative real-time PCR (qRT-PCR).

Results: There were overexpressed lncRNAs IFNG-AS1 and GAS5 in serum of childhood ITP patients [(median (IQR) = 3.08 (0.2–22.39) and 4.19 (0.9–16.91) respectively, Also, significant higher IFNG-AS1 and GAS5 (p < 0.05) were present in persistent ITP (3–12 months) [ median (IQR) = 4.58 (0.31–22.39) and 3.77 (0.87–12.36) respectively] or chronic ITP (>12 months) [ median (IQR) = 5.6 (0.25–12.59) and 5.61 (1.15–16.91) respectively] when compared to newly diagnosed <3 months patients [IFNG-AS1 median (IQR) = 1.21 (0.2–8.95), and GAS5 median (IQR) = 1.07 (0.09–3.55)]. Also, significant higher lncRNAs IFNG-AS1 and GAS5 were present in patients with partial response to treatment [IFNG-AS1 median (IQR) = 4.15 (0.94–19.25), and GAS5 (median (IQR) = 4.25 (0.81–16.91)] or non-response [IFNG-AS1 median (IQR) = 4.19 (1.25–22.39) and GAS5 median (IQR) = 5.11 (2.34–15.27)] when compared to patients who completely responded to treatment (IFNG-AS1 median (IQR) = 2.09 (0.2–14.58) and GAS5 (median (IQR) = 2.51 (0.09–10.33). In addition, following therapy, the expressions of IFNG-AS1 and GAS5 are significantly negatively correlated with platelet count.

Conclusion: Findings suggest that lncRNAs IFNG-AS1 and GAS5 are novel diagnostic and prognostic genetic markers for childhood ITP that can aid in a precise prediction of the disease’s progress at the time of diagnosis and could be a useful tool for treatment planning.

Deregulated Clusterin as a Marker of Bone Fragility: New Insights into the Pathophysiology of Osteoporosis

Clusterin (CLU) is a secreted heterodimeric glycoprotein expressed in all organism fluids as well as in the intracellular matrix that plays key roles in several pathological processes. Its recent involvement in muscle degeneration of osteoporotic patients led to investigation of the role of CLU in bone metabolism, given the biochemical and biomechanical crosstalk of the bone–muscle unit. Quantitative real time-polymerase chain reaction (qRT-PCR) analysis of CLU expression was performed in both osteoblasts and Peripheral Blood Mononuclear Cells (PBMCs) from osteoporotic patients (OP) and healthy individuals (CTR). Furthermore, immunohistochemical analysis on femoral head tissues and enzyme-linked immunosorbent assay (ELISA) in plasma samples were performed to investigate CLU expression pattern. Finally, genotyping of CLU rs11136000 polymorphism has also been performed by qRT-PCR assays to explore a possible association with CLU expression levels. Data obtained showed a significantly increased expression level of secreted CLU isoform in PBMCs and osteoblasts from OP patients. Immunohistochemical analysis confirms the increased expression of CLU in OP patients, both in osteocytes and osteoblasts, while plasma analysis reveals a statistically significant decrease of CLU levels. Unfortunately, no functional association between CLU expression levels and the presence of CLU rs11136000 polymorphism in OP patients was found. These data suggest a potential role played by CLU as a potential biomarker for the diagnosis and prognosis of OP progression.

AMD Genomics: Non-Coding RNAs as Biomarkers and Therapeutic Targets

Age-related macular degeneration (AMD) is a progressive neurodegenerative disease that is the world’s leading cause of blindness in the aging population. Although the clinical stages and forms of AMD have been elucidated, more specific prognostic tools are required to determine when patients with early and intermediate AMD will progress into the advanced stages of AMD. Another challenge in the field has been the appropriate development of therapies for intermediate AMD and advanced atrophic AMD. After numerous negative clinical trials, an anti-C5 agent and anti-C3 agent have recently shown promising results in phase 3 clinical trials, in terms of slowing the growth of geographic atrophy, an advanced form of AMD. Interestingly, both drugs appear to be associated with an increased incidence of wet AMD, another advanced form of the disease, and will require frequent intravitreal injections. Certainly, there remains a need for other therapeutic agents with the potential to prevent progression to advanced stages of the disease. Investigation of the role and clinical utility of non-coding RNAs (ncRNAs) is a major advancement in biology that has only been minimally applied to AMD. In the following review, we discuss the clinical relevance of ncRNAs in AMD as both biomarkers and therapeutic targets.

Long Noncoding RNA GAS5: A New Factor Involved in Bone Diseases

Long noncoding RNAs (lncRNAs), as an important type of RNA encoded in the human transcriptome, have shown to regulate different genomic processes in human cells, altering cell type and function. These factors are associated with carcinogenesis, cancer metastasis, bone diseases, and immune system diseases, among other pathologies. Although many lncRNAs are involved in various diseases, the molecular mechanisms through which lncRNAs contribute to regulation of disease are still unclear. The lncRNA growth arrest-specific 5 (GAS5) is a key player that we initially found to be associated with regulating cell growth, differentiation, and development. Further work has shown that GAS5 is involved in the occurrence and prognosis of bone diseases, such as osteoporosis, osteosarcoma, and postosteoporotic fracture. In this review, we discuss recent progress on the roles of GAS5 in bone diseases to establish novel targets for the treatment of bone diseases.

Long noncoding RNA GAS5 in age-related diseases

Aging refers to a natural process and a universal phenomenon in all cells, tissues, organs and the whole organism. Long non-coding RNAs (lncRNAs) are non-coding RNAs with the length of 200 nucleotides. LncRNA growth arrest-specific 5 (lncRNA GAS5) is often down-regulated in cancer. The accumulation of lncRNA GAS5 has been found to be able to inhibit cancer growth, invasion and metastasis, while enhancing the sensitivity of cells to chemotherapy drugs. LncRNA GAS5 can be a signaling protein, which is specifically transcribed under different triggering conditions. Subsequently, it is involved in signal transmission in numerous pathways as a signal node. LncRNA GAS5, with a close relationship to multiple miRNAs, was suggested to be involved in the signaling pathway under three action modes (i.e., signal, bait and guidance). LncRNA GAS5 was found to be involved in different age-related diseases (e.g., rheumatoid arthritis, type 2 diabetes, atherosclerosis, osteoarthritis, osteoporosis, multiple sclerosis, cancer etc.). This study mainly summarized the regulatory effect exerted by lncRNA GAS5 on age-related diseases.

Increased Plasma Levels of lncRNAs LINC01268, GAS5 and MALAT1 Correlate with Negative Prognostic Factors in Myelofibrosis

Simple Summary

Myelofibrosis (MF) displays the worst prognosis among Philadelphia-negative chronic myeloproliferative neoplasms. There is no curative therapy for MF, except for bone marrow transplantation, which however has a consistent percentage of failure. There is thus an urgent need of novel biomarkers to complement current stratification models and to enable better management of patients. To address this issue, we herein measured the plasma levels of several long noncoding RNAs (lncRNAs). Circulating lncRNAs has been already largely described as potential non-invasive biomarkers in cancers. In our study we unveiled that LINC01268, MALAT1 (both p < 0.0001) and GAS5 (p = 0.0003) plasma levels are significantly higher in MF patients if compared with healthy donors, and their increased plasma levels correlate with several detrimental features in MF. Among them, LINC01268 is an independent variable for both OS (p = 0.0297) and LFS (p = 0.0479), thus representing a putative new biomarker suitable for integrate contemporary prognostic models.

Abstract

Long non-coding RNAs (lncRNAs) have been recently described as key mediators in the development of hematological malignancies. In the last years, circulating lncRNAs have been proposed as a new class of non-invasive biomarkers for cancer diagnosis and prognosis and to predict treatment response. The present study is aimed to investigate the potential of circulating lncRNAs as non-invasive prognostic biomarkers in myelofibrosis (MF), the most severe among Philadelphia-negative myeloproliferative neoplasms. We detected increased levels of seven circulating lncRNAs in plasma samples of MF patients (n = 143), compared to healthy controls (n = 65). Among these, high levels of LINC01268, MALAT1 or GAS5 correlate with detrimental clinical variables, such as high count of leukocytes and CD34+ cells, severe grade of bone marrow fibrosis and presence of splenomegaly. Strikingly, high plasma levels of LINC01268 (p = 0.0018), GAS5 (p = 0.0008) or MALAT1 (p = 0.0348) are also associated with a poor overall-survival while high levels of LINC01268 correlate with a shorter leukemia-free-survival. Finally, multivariate analysis demonstrated that the plasma level of LINC01268 is an independent prognostic variable, suggesting that, if confirmed in future in an independent patients’ cohort, it could be used for further studies to design an updated classification model for MF patients.

DNA Methylation Signatures of Bone Metabolism in Osteoporosis and Osteoarthritis Aging-Related Diseases: An Updated Review

DNA methylation is one of the most studied epigenetic mechanisms that play a pivotal role in regulating gene expression. The epigenetic component is strongly involved in aging-bone diseases, such as osteoporosis and osteoarthritis. Both are complex multi-factorial late-onset disorders that represent a globally widespread health problem, highlighting a crucial point of investigations in many scientific studies. In recent years, new findings on the role of DNA methylation in the pathogenesis of aging-bone diseases have emerged. The aim of this systematic review is to update knowledge in the field of DNA methylation associated with osteoporosis and osteoarthritis, focusing on the specific tissues involved in both pathological conditions.

The Involvement of Long Non-Coding RNAs in Bone

A harmonious balance between osteoblast and osteoclast activity guarantees optimal bone formation and resorption, pathological conditions affecting the bone may arise. In recent years, emerging evidence has shown that epigenetic mechanisms play an important role during osteoblastogenesis and osteoclastogenesis processes, including long non-coding RNAs (lncRNAs). These molecules are a class of ncRNAs with lengths exceeding 200 nucleotides not translated into protein, that have attracted the attention of the scientific community as potential biomarkers to use for the future development of novel diagnostic and therapeutic approaches for several pathologies, including bone diseases. This review aims to provide an overview of the lncRNAs and their possible molecular mechanisms in the osteoblastogenesis and osteoclastogenesis processes. The deregulation of their expression profiles in common diseases associated with an altered bone turnover is also described. In perspective, lncRNAs could be considered potential innovative molecular biomarkers to help with earlier diagnosis of bone metabolism-related disorders and for the development of new therapeutic strategies.