Characterization of Extracellular Vesicles in Osteoporotic Patients Compared to Osteopenic and Healthy Controls

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.

Proteomic Insights into Osteoporosis: Unraveling Diagnostic Markers of and Therapeutic Targets for the Metabolic Bone Disease

Osteoporosis (OP), a prevalent skeletal disorder characterized by compromised bone strength and increased susceptibility to fractures, poses a significant public health concern. This review aims to provide a comprehensive analysis of the current state of research in the field, focusing on the application of proteomic techniques to elucidate diagnostic markers and therapeutic targets for OP. The integration of cutting-edge proteomic technologies has enabled the identification and quantification of proteins associated with bone metabolism, leading to a deeper understanding of the molecular mechanisms underlying OP. In this review, we systematically examine recent advancements in proteomic studies related to OP, emphasizing the identification of potential biomarkers for OP diagnosis and the discovery of novel therapeutic targets. Additionally, we discuss the challenges and future directions in the field, highlighting the potential impact of proteomic research in transforming the landscape of OP diagnosis and treatment.

Prevalence and plasma exosome-derive microRNA diagnostic biomarker screening of adolescent idiopathic scoliosis in Yunnan Province, China

Background

Idiopathic scoliosis significantly affects the physical and mental health of children and adolescents, with varying prevalence rates in different regions. The occurrence of idiopathic scoliosis is associated with genetic regulation and biochemical factors, but the changes in exosome-derived miRNA profiles among idiopathic scoliosis patients remain unclear. This study aimed to determine the prevalence of idiopathic scoliosis in Yunnan Province, China, and identify key exosome-derived miRNAs in idiopathic scoliosis through a cohort study.

Methods

From January 2018 to December 2020, a cross-sectional study on idiopathic scoliosis in children and adolescents was conducted in Yunnan Province. A total of 84,460 students from 13 cities and counties in Yunnan Province participated in a scoliosis screening program, with ages ranging from 7 to 19 years. After confirmation through screening and imaging results, patients with severe idiopathic scoliosis and normal control individuals were selected using propensity matching. Subsequently, plasma exosome-derived miRNA sequencing and RT-qPCR validation were performed separately. Based on the validation results, diagnostic performance analysis and target gene prediction were conducted for differential plasma exosome-derived miRNAs.

Results

The overall prevalence of idiopathic scoliosis in children and adolescents in Yunnan Province was 1.10%, with a prevalence of 0.87% in males and 1.32% in females. The peak prevalence was observed at age 13. Among patients diagnosed with idiopathic scoliosis, approximately 12.8% had severe cases, and there were more cases of double curvature than of single curvature, with thoracolumbar curvature being the most common in the single-curvature group. Sequencing of plasma exosome-derived miRNAs associated with idiopathic scoliosis revealed 56 upregulated and 153 downregulated miRNAs. Further validation analysis confirmed that hsa-miR-27a-5p, hsa-miR-539-5p, and hsa-miR-1246 have potential diagnostic value.

Conclusions

We gained insights into the epidemiological characteristics of idiopathic scoliosis in Yunnan Province and conducted further analysis of plasma exosome-derived miRNA changes in patients with severe idiopathic scoliosis. This study has provided new insights for the prevention and diagnosis of idiopathic scoliosis, paving the way for exploring clinical biomarkers and molecular regulatory mechanisms. However, further validation and elucidation of the detailed biological mechanisms underlying these findings will be required in the future.

Treatment for Gorham-Stout syndrome with a combination of teriparatide and denosumab

Gorham-Stout syndrome is an aggressive, non-hereditary, and rare disease affecting bone metabolism. Its etiology and pathogenesis remain elusive. The syndrome manifests with diverse clinical symptoms, often leading to frequent misdiagnoses and presenting challenges in treatment. In this study, we report a case of cranial and maxillary osteolysis in a 47-year-old female patient with somatic mutations in the VEGF-A, VEGF-B, and VEGF-C genes and the EPHB4 gene. After treatment with bisphosphonates, this patient still had persistent resorption of the mandible, but switching to a teriparatide and denosumab combination yielded substantial improvement. This study is the first report to show that teriparatide combined with denosumab can be used to treat Gorham-Stout syndrome.

Mechanism of Circ_HECW2 regulating osteoblast apoptosis in osteoporosis by attenuating the maturation of miR-1224-5p

BACKGROUND

Osteoporosis (OP) poses a significant clinical challenge with escalating morbidity. This study explores Circ_HECW2 expression in OP patients and its regulatory role in lipopolysaccharide (LPS)-induced osteoblast apoptosis.

METHODS

Circ_HECW2 expression in OP patient serum and healthy controls was quantified using RT-qPCR. Diagnostic value of Circ_HECW2 for OP was assessed via ROC curve. Pearson's correlation model examined associations between indicators. Human osteoblasts HFOB1.19, treated with LPS, were analyzed for Circ_HECW2, pre-miR-1224, miR-1224-5p, and PDK2 mRNA levels. TUNEL assay determined cell apoptosis and Western blot assessed cleaved-caspase-3 protein levels. RNase R resistance assay and actinomycin D assay confirmed Circ_HECW2's cyclic structure. RNA pull-down and dual-luciferase reporter assay verified binding relationships between Circ_HECW2 and miR-1224 and between miR-1224-5p and PDK2.

RESULTS

Circ_HECW2 exhibited elevated expression in OP patients with diagnostic significance and a negative correlation with lumbar T-score. LPS co-culture increased Circ_HECW2 expression in HFOB1.19 cells, significantly elevating apoptosis index and cleaved-caspase-3. Circ_HECW2 downregulation inhibited HFOB1.19 apoptosis, reduced pre-miR-1224 expression, and elevated mature miR-1224-5p. Circ_HECW2 bound to pre-miR-1224, and inhibiting miR-1224-5p reversed the effect of Circ_HECW2 downregulation on osteoblast apoptosis. miR-1224-5p targeted PDK2 transcription.

CONCLUSION

Circ_HECW2, highly expressed in OP, holds diagnostic significance and reflects disease severity. Circ_HECW2 reduces mature miR-1224-5p by binding to pre-miR-1224, upregulating PDK2, and facilitating LPS-induced osteoblast apoptosis.

Identification of toll-like receptor 5 and acyl-CoA synthetase long chain family member 1 as hub genes are correlated with the severe forms of COVID-19 by Weighted gene co-expression network analysis

Since a 25% mortality rate occurred in critical Coronavirus disease 2019 (COVID-19) patients, investigating the potential drivers remains to be important. Here, the authors applied Weighted Gene Co-expression Network Analysis to identify the potential drivers in the blood samples of multiple COVID-19 expression profiles. The authors found that the darkslateblue module was significantly correlated with critical COVID-19, and Gene Ontology analysis indicated terms associated with the inflammation pathway and apoptotic process. The authors intersected differentially expressed genes, Maximal Clique Centrality calculated hub genes, and COVID-19 related genes in the Genecards dataset, and two genes, toll-like receptor 5 (TLR5) and acyl-CoA synthetase long chain family member 1 (ACSL1), were screened out. The Gene Set Enrichment Analysis further supports their core role in the inflammatory pathway. Furthermore, the cell-type identification by estimating relative subsets of RNA transcript demonstrated that TLR5 and ACSL1 were associated with neutrophil enrichment in critical COVID-19 patients. Collectively, the aurthors identified two hub genes that were strongly correlated with critical COVID-19. These may help clarify the pathogenesis and assist the immunotherapy development.

Annexin A5 derived from matrix vesicles protects against osteoporotic bone loss via mineralization

Matrix vesicles (MVs) have shown strong effects in diseases such as vascular ectopic calcification and pathological calcified osteoarthritis and in wound repair of the skeletal system due to their membranous vesicle characteristics and abundant calcium and phosphorus content. However, the role of MVs in the progression of osteoporosis is poorly understood. Here, we report that annexin A5, an important component of the matrix vesicle membrane, plays a vital role in bone matrix homeostasis in the deterioration of osteoporosis. We first identified annexin A5 from adherent MVs but not dissociative MVs of osteoblasts and found that it could be sharply decreased in the bone matrix during the occurrence of osteoporosis based on ovariectomized mice. We then confirmed its potential in mediating the mineralization of the precursor osteoblast lineage via its initial binding with collagen type I to achieve MV adhesion and the subsequent activation of cellular autophagy. Finally, we proved its protective role in resisting bone loss by applying it to osteoporotic mice. Taken together, these data revealed the importance of annexin A5, originating from adherent MVs of osteoblasts, in bone matrix remodeling of osteoporosis and provided a new strategy for the treatment and intervention of bone loss.

Circulating and extracellular vesicle-derived microRNAs as biomarkers in bone-related diseases

MicroRNAs (miRNA) are small non-coding RNA molecules that regulate posttranscriptional gene expression by repressing messengerRNA-targets. MiRNAs are abundant in many cell types and are secreted into extracellular fluids, protected from degradation by packaging in extracellular vesicles. These circulating miRNAs are easily accessible, disease-specific and sensitive to small changes, which makes them ideal biomarkers for diagnostic, prognostic, predictive or monitoring purposes. Specific miRNA signatures can be reflective of disease status and development or indicators of poor treatment response. This is especially important in malignant diseases, as the ease of accessibility of circulating miRNAs circumvents the need for invasive tissue biopsy. In osteogenesis, miRNAs can act either osteo-enhancing or osteo-repressing by targeting key transcription factors and signaling pathways. This review highlights the role of circulating and extracellular vesicle-derived miRNAs as biomarkers in bone-related diseases, with a specific focus on osteoporosis and osteosarcoma. To this end, a comprehensive literature search has been performed. The first part of the review discusses the history and biology of miRNAs, followed by a description of different types of biomarkers and an update of the current knowledge of miRNAs as biomarkers in bone related diseases. Finally, limitations of miRNAs biomarker research and future perspectives will be presented.

Research progress on the role of extracellular vesicles derived from aging cells in osteoporosis

The occurrence and development of many diseases are highly associated with the aging of the body. Among them, osteoporosis (OP) is a common age-related disease that tends to occur in the elderly population and is highly related to the aging factors in the body. In the process of aging transmission, the senescence-related secretory phenotype (SASP) can convey the information about aging through the paracrine pathway and endocrine mechanism through the extracellular vesicles (EVs) connected to SASP. EVs can be used as a way of conduction to join the connection between micro-environmental aging and age-related illnesses. EVs are double-layer membranous vesicles separated or secreted from the cell membrane, which mainly include microvesicles (MVs) and exosomes. Vesicular bodies secreted by this exocrine form carry a variety of cell-derived related substances (including a variety of proteins, lipids, DNA, mRNA, miRNAs, etc). These substances are mainly concentrated in human body fluids, especially can be transported to all parts of the body with the blood circulation system, and participate in the interactions between cells. Osteoporosis is closely associated with aging and aging cells, suggesting EVs were active in this pathological process. In this article, the basic mechanisms of aging cells in the occurrence and progression of osteoporosis through EVs will be discussed, to explore the connection between aging and osteoporosis, thereby providing a new perspective on the occurrence and development as well as prevention and treatment of osteoporosis.