MicroRNA‑338‑3p regulates age‑associated osteoporosis via targeting PCSK5

RNA sequencing-based approaches to identifying disulfidptosis-related diagnostic clusters and immune landscapes in osteoporosis

Disulfidptosis, a newly recognized cell death triggered by disulfide stress, has garnered attention for its potential role in osteoporosis (OP) pathogenesis. Although sulfide-related proteins are reported to regulate the balance of bone metabolism in OP, the precise involvement of disulfidptosis regulators remains elusive. Herein, leveraging the GSE56815 dataset, we conducted an analysis to delineate disulfidptosis-associated diagnostic clusters and immune landscapes in OP. Subsequently, vertebral bone tissues obtained from OP patients and controls were subjected to RNA sequencing (RNA-seq) for the validation of key disulfidptosis gene expression. Our analysis unveiled seven significant disulfidptosis regulators, including FLNA, ACTB, PRDX1, SLC7A11, NUBPL, OXSM, and RAC1, distinguishing OP samples from controls. Furthermore, employing a random forest model, we identified four diagnostic disulfidptosis regulators including FLNA, SLC7A11, NUBPL, and RAC1 potentially predictive of OP risk. A nomogram model integrating these four regulators was constructed and validated using the GSE35956 dataset, demonstrating promising utility in clinical decision-making, as affirmed by decision curve analysis. Subsequent consensus clustering analysis stratified OP samples into two different disulfidptosis subgroups (clusters A and B) using significant disulfidptosis regulators, with cluster B exhibiting higher disulfidptosis scores and implicating monocyte immunity, closely linked to osteoclastogenesis. Notably, RNA-seq analysis corroborated the expression patterns of two disulfidptosis modulators, PRDX1 and OXSM, consistent with bioinformatics predictions. Collectively, our study sheds light on disulfidptosis patterns, offering potential markers and immunotherapeutic avenues for future OP management.

Therapeutic effects of resveratrol on epigenetic mechanisms in age-related diseases: A comprehensive review

Recently, various studies have shown that epigenetic changes are associated with aging and age-related diseases. Both animal and human models have revealed that epigenetic processes are involved in aging mechanisms. These processes happen at multiple levels and include histone modification, DNA methylation, and changes in noncoding RNA expression. Consequently, changes in the organization of chromatin and DNA accessibility lead to the regulation of gene expression. With increasing awareness of the pivotal function of epigenetics in the aging process, researchers' attention has been drawn to how these epigenetic changes can be modified to prevent, stop, or reverse aging, senescence, and age-related diseases. Among various agents that can affect epigenetic, polyphenols are well-known phytochemicals found in fruits, vegetables, and plants. Polyphenols are found to modify epigenetic-related mechanisms in various diseases and conditions, such as metabolic disorders, obesity, neurodegenerative diseases, cancer, and cardiovascular diseases. Resveratrol (RSV) is a member of the stilbene subgroup of polyphenols which is derived from various plants, such as grapes, apples, and blueberries. Therefore, herein, we aim to summarize how RSV affects different epigenetic processes to change aging-related mechanisms. Furthermore, we discuss its roles in age-related diseases, such as Alzheimer's, Parkinson's, osteoporosis, and cardiovascular diseases.

Circular RNA circ-3626 promotes bone formation by modulating the miR-338-3p/Runx2 axis

OBJECTIVE

Disorders of bone homeostasis are the key factors leading to metabolic bone disease, such as senile osteoporosis, which is characterized by age-related bone loss. Bone marrow stromal cells (BMSCs) possess high osteogenic capacity which has been regarded as a practical approach to preventing bone loss. Previous studies have shown that the osteogenic differentiation ability of BMSCs is significantly decreased in senile osteoporosis. Recently, circular RNAs (circRNAs) have been regarded as critical regulators in controlling the osteogenic differentiation of BMSCs by sponging microRNAs (miRNAs). Our study aimed to discover new and critical osteogenesis-related circRNAs that can promote bone formation in senile osteoporosis.

METHODS

We detected the dysregulated circRNAs of BMSCs upon osteogenic differentiation induction and identified the critical osteogenic circRNA (circ-3626). The relationship between circ-3626 and osteoporosis was further verified in clinical bone samples and aged mice by qPCR. Moreover, circ-3626 AAV was constructed to examine the osteogenic effect of circ-3626 on bone formation via using Micro-CT, double calcein labeling, and the three-point bending tests. Bioinformatics analysis, Luciferase report gene assays, FISH, RNA pull-down, qPCR, Western Blots, and alizarin red staining assay explore the effects and mechanisms of circ-3626 on osteogenic differentiation of BMSCs.

RESULTS

Circ-3626 was identified as a pivotal osteogenesis-related circRNA via RNA sequencing. The results of alizarin red staining, Western blots, and qPCR assays suggest that overexpressing circ-3626 dramatically accelerates the osteogenic capability of BMSCs. Furthermore, the bone repair capability of aging mice could be significantly improved by circ-3626 AAV treatment. Micro RNA miR-338-3p was identified as the downstream target of circ-3626. Overexpression of circ-3626 increases the expression of Runx2 by sponging miR-338-3p, thereby promoting the osteogenic differentiation of BMSCs by upregulating the expression of osteogenic genes. In addition, Western blots, and qPCR assays suggest circ-3626 AAV treatment promote the expression of Runx2 and osteogenic marker genes.

CONCLUSION

Thus, we demonstrate that circ-3626 plays a pivotal role in promoting bone formation through the miR-338-3p/Runx2 axis and may provide new strategies for preventing and treating the bone loss of senile osteoporosis.

Bone marrow mesenchymal stem cell-derived exosomes promote osteoblast proliferation, migration and inhibit apoptosis by regulating KLF3-AS1/miR-338-3p

AIM

This study aimed to investigate the effect and mechanism of bone marrow mesenchymal stem cell-derived exosomes on osteoblast function.

METHODS

The expression of KLF3-AS1 and miR-338-3p in serum of fracture patients was detected by qRT-PCR. Exosomes from BMSCs were isolated by ultrafast centrifugation. MC3T3-E1 cells were cultured in vitro as experimental cells. Intracellular gene expression was regulated by transfection of si-KLF3-AS1 or miR-338-3p inhibitors. MTT assay, Transwell assay and flow cytometry were used to evaluate cell viability, migration, and apoptosis. The luciferase reporter gene was used to verify the targeting relationship between KLF3-AS1 and miR-338-3p. Bioinformatics analysis was used to identify the basic functions and possible enrichment pathways of miR-338-3p target genes.

RESULTS

The expressions of KLF3-AS1 and miR-338-3p in the serum of fracture patients were down-regulated and up-regulated, respectively. The expression of KLF3-AS1 was increased in MC3T3-E1 cells cultured with BMSCs-Exo, while the viability and migration ability of MC3T3-E1 cells were enhanced, and the apoptosis ability was weakened. Further analysis revealed miR-338-3p was the target gene of KLF3-AS1. The expression of miR-338-3p was downregulated in MC3T3-E1 cells cultured with BMSCs-Exo. Inhibition of miR-338-3p in MC3T3-E1 cells enhanced the viability and migration ability of MC3T3-E1 cells when cultured with BMSCs-Exo, while suppressing apoptosis. Bioinformatics analysis demonstrated that the target genes of miR-338-3p were predominantly localized at the axon's initiation site, involved in biological processes such as development and growth regulation, and mainly enriched in MAPK and ErbB signaling pathways.

CONCLUSION

In vitro, BMSCs-Exo exhibits the capacity to enhance proliferation and migration while inhibiting apoptosis of MC3T3-E1 cells, potentially achieved through modulation of KLF3-AS1 and miR-338-3p expression in MC3T3-E1 cells.

Inhibiting MicroRNA-141-3p Improves Musculoskeletal Health in Aged Mice

Emerging evidence shows that the microRNA-141-3p is involved in various age-related pathologies. Previously, our group and others reported elevated levels of miR-141-3p in several tissues and organs with age. Here, we inhibited the expression of miR-141-3p using antagomir (Anti-miR-141-3p) in aged mice and explored its role in healthy aging. We analyzed serum (cytokine profiling), spleen (immune profiling), and overall musculoskeletal phenotype. We found decreased levels of pro-inflammatory cytokines (such as TNF-α, IL-1β, IFN-γ) in serum with Anti-miR-141-3p treatment. The flow-cytometry analysis on splenocytes revealed decreased M1 (pro-inflammatory) and increased M2 (anti-inflammatory) populations. We also found improved bone microstructure and muscle fiber size with Anti-miR-141-3p treatment. Molecular analysis revealed that miR-141-3p regulates the expression of AU-rich RNA-binding factor 1 (AUF1) and promotes senescence (p21, p16) and pro-inflammatory (TNF-α, IL-1β, IFN-γ) environment whereas inhibiting miR-141-3p prevents these effects. Furthermore, we demonstrated that the expression of FOXO-1 transcription factor was reduced with Anti-miR-141-3p and elevated with silencing of AUF1 (siRNA-AUF1), suggesting crosstalk between miR-141-3p and FOXO-1. Overall, our proof-of-concept study demonstrates that inhibiting miR-141-3p could be a potential strategy to improve immune, bone, and muscle health with age.

Surface modification of silica nonwoven fabrics for osteogenesis of bone marrow-derived mesenchymal stem cells

Silica nonwoven fabrics (SNFs) with high mechanical strength and porosity are known to exhibit high cell proliferation and osteogenic differentiation potential of mesenchymal stem cells (MSCs) by morphologically mimicking the extracellular matrix (ECM). To further improve the osteoinductive ability of SNFs, it could be effective to increase the interaction between MSCs and ECM components because exogenous ECM components seem to modulate the fate of MSCs differentiation. In this study, we developed immobilization methods for ECM components, such as collagen, fibronectin, and chondroitin sulphate C on SNFs, to improve cell-matrix interactions and examined their suitability for bone tissue regeneration. Collagen and fibronectin were immobilized via physical adsorption and chondroitin sulphate C was also immobilized by the layer-by-layer method combined with chitosan on SNF surfaces to maintain the high porosity of SNFs. The treated SNFs were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. In osteogenic differentiation culture, modified SNFs showed significantly increased expression of osteogenic differentiation marker genes compared to unmodified SNFs. These results suggest that the present methods improve cell-matrix interactions and enhance the cellular functions of MSCs. We are convinced that these simple modification techniques for ECM components are effective in functionalizing various 3D fabric scaffolds possessing hydrophilic groups.

GDF15, an emerging key player in human aging

Growth differentiation factor 15 (GDF15) is recently emerging not only as a stress-related mitokine, but also as a key player in the aging process, being one of the most up-regulated protein with age and associated with a variety of age-related diseases (ARDs). Many data indicate that GDF15 has protective roles in several tissues during different stress and aging, thus playing a beneficial role in apparent contrast with the observed association with many ARDs. A possible detrimental role for this protein is then hypothesized to emerge with age. Therefore, GDF15 can be considered as a pleiotropic factor with beneficial activities that can turn detrimental in old age possibly when it is chronically elevated. In this review, we summarize the current knowledge on the biology of GDF15 during aging. We also propose GDF15 as a part of a dormancy program, where it may play a role as a mediator of defense processes aimed to protect from inflammatory damage and other stresses, according to the life history theory.

Contribution of miRNAs and lncRNAs in osteogenesis and related disorders

Non-coding RNAs have been found to regulate several developmental processes among them is osteogenesis. Although these transcripts have several distinct classes, two classes i.e. microRNAs and long non-coding RNAs have attained more attention. These transcripts regulate intramembranous as well as endochondral ossification processes. The effects of microRNAs on osteogenesis are mostly mediated through modulation of Wnt/β-catenin and TGFβ/BMP pathways. Long non-coding RNAs can directly affect expression of these pathways or osteogenic transcription factors. Moreover, they can serve as a molecular sponge for miRNAs. MALAT1/miR-30, MALAt1/miR-214, LEF1-AS1/miR-24-3p, MCF2L-AS1/miR-33a, MSC-AS1/miR-140-5p and KCNQ1OT1/miR-214 are examples of such kind of interaction between lncRNAs and miRNAs in the context of osteogenesis. In the current paper, we explain these two classes of non-coding RNAs in the osteogenesis and related disorders.

Application of microRNA in Human Osteoporosis and Fragility Fracture: A Systemic Review of Literatures

MicroRNAs (miRNAs) could serve as ideal entry points to the deregulated pathways in osteoporosis due to their relatively simple upstream and downstream relationships with other molecules in the signaling cascades. Our study aimed to give a comprehensive review of the already identified miRNAs in osteoporosis from human blood samples and provide useful information for their clinical application. A systematic literature search for relevant studies was conducted in the Pubmed database from inception to December 2020. We set two essential inclusion criteria: human blood sampling and design of controlled studies. We sorted the results of analysis on human blood samples according to the study settings and compiled the most promising miRNAs with analyzed diagnostic values. Furthermore, in vitro and in vivo evidence for the mechanisms of the identified miRNAs was also illustrated. Based on both diagnostic value and evidence of mechanism from in vitro and in vivo experiments, miR-23b-3p, miR-140-3p, miR-300, miR-155-5p, miR-208a-3p, and miR-637 were preferred candidates in diagnostic panels and as therapeutic agents. Further studies are needed to build sound foundations for the clinical usage of miRNAs in osteoporosis.

The role of microRNA-338-3p in cancer: growth, invasion, chemoresistance, and mediators

Cancer still remains as one of the leading causes of death worldwide. Metastasis and proliferation are abnormally increased in cancer cells that subsequently, mediate resistance of cancer cells to different therapies such as radio-, chemo- and immune-therapy. MicroRNAs (miRNAs) are endogenous short non-coding RNAs that can regulate expression of target genes at post-transcriptional level and capable of interaction with mRNA-coding genes. Vital biological mechanisms including apoptosis, migration and differentiation are modulated by these small molecules. MiRNAs are key players in regulating cancer proliferation and metastasis as well as cancer therapy response. MiRNAs can function as both tumor-suppressing and tumor-promoting factors. In the present review, regulatory impact of miRNA-338-3p on cancer growth and migration is discussed. This new emerging miRNA can regulate response of cancer cells to chemotherapy and radiotherapy. It seems that miRNA-338-3p has dual role in cancer chemotherapy, acting as tumor-promoting or tumor-suppressor factor. Experiments reveal anti-tumor activity of miRNA-338-3p in cancer. Hence, increasing miRNA-338-3p expression is of importance in effective cancer therapy. Long non-coding RNAs, circular RNAs and hypoxia are potential upstream mediators of miRNA-338-3p in cancer. Anti-tumor agents including baicalin and arbutin can promote expression of miRNA-338-3p in suppressing cancer progression. These topics are discussed to shed some light on function of miRNA-338-3p in cancer cells.