Search Results (93)

Endometrial mesenchymal stem cells (eMSCs) are a novel and biologically potent source of multipotent stromal cells with potential beyond reproductive medicine. This study explored their phenotypic profile, trilineage differentiation, and the cytoprotective effects of their conditioned media (eMSCCM) on oxidatively stressed neonatal and adult chondrocytes. Canine eMSCs displayed typical fibroblast-like morphology and expressed high levels of mesenchymal surface markers CD29 and CD44, low hematopoietic markers CD34/CD45, and variable CD90, confirming a mesenchymal identity. Differentiation assays revealed osteogenic and chondrogenic differentiation, whereas adipogenic activity was limited. Using eMSCCM at 25% and 50% concentrations, chondrocyte viability was assessed after exposure to 200 µM H₂O₂. eMSCCM significantly enhanced the viability of H₂O₂-stressed chondrocytes in a dose-dependent manner, particularly at 50%, with marked effects at 24 and 48 h. Although metabolic activity declined at 72 h, the treated cells remained more metabolically active than untreated controls. These findings suggest that eMSCCM offers promising cytoprotective effects for cartilage-related oxidative stress conditions. Full article

Background/Objectives: Cannabinoid use is rising among patients undergoing spinal fusion, yet its influence on bone healing is poorly defined. The endocannabinoid system (ECS)—through cannabinoid receptors 1 (CB1) and 2 (CB2)—modulates skeletal metabolism. We reviewed preclinical, mechanistic and clinical evidence to clarify how individual cannabinoids affect fracture repair and spinal arthrodesis. Methods: PubMed, Web of Science and Scopus were searched from inception to 31 May 2025 with the terms “cannabinoid”, “CB1”, “CB2”, “spinal fusion”, “fracture”, “osteoblast” and “osteoclast”. Animal studies, in vitro experiments and clinical reports that reported bone outcomes were eligible. Results: CB2 signaling was uniformly osteogenic. CB2-knockout mice developed high-turnover osteoporosis, whereas CB2 agonists (HU-308, JWH-133, HU-433, JWH-015) restored trabecular volume, enhanced osteoblast activity and strengthened fracture callus. Cannabidiol (CBD), a non-psychoactive phytocannabinoid with CB2 bias, accelerated early posterolateral fusion in rats and reduced the RANKL/OPG ratio without compromising final union. In contrast, sustained or high-dose Δ⁹-tetrahydrocannabinol (THC) activation of CB1 slowed chondrocyte hypertrophy, decreased mesenchymal-stromal-cell mineralization and correlated clinically with 6–10% lower bone-mineral density and a 1.8–3.6-fold higher pseudarthrosis or revision risk. Short-course or low-dose THC appeared skeletal neutral. Responses varied with sex, age and genetic background; no prospective trials defined safe perioperative dosing thresholds. Conclusions: CB2 activation and CBD consistently favor bone repair, whereas chronic high-THC exposure poses a modifiable risk for nonunion in spine surgery. Prospective, receptor-specific trials stratified by THC/CBD ratio, patient sex and ECS genotype are needed to establish evidence-based cannabinoid use in spinal fusion. Full article

Background/Objectives: Lumbar disc herniation (LDH) is the most common condition associated with low back pain, and it adversely impacts individuals’ health. The interplay between energy metabolism and apoptosis is critical, as the loss of viable cells in the intervertebral disc (IVD) can lead to a cascade of degenerative changes. Efferocytosis is a key biological process that maintains homeostasis by removing apoptotic cells, resolving inflammation, and promoting tissue repair. Therefore, enhancing mitochondrial energy metabolism and efferocytosis function in IVD cells holds great promise as a potential therapeutic approach for LDH. Methods: In this study, energy metabolism and efferocytosis-related differentially expressed genes (EMERDEGs) were identified from the transcriptomic datasets of LDH. Machine learning approaches were used to identify key genes. Functional enrichment analyses were performed to elucidate the biological roles of these genes. The functions of the hub genes were validated by RT-qPCR. The CIBERSORT algorithm was used to compare immune infiltration between LDH and Control groups. Additionally, we used single-cell RNA sequencing dataset to analyze cell-specific expression of the hub genes. Results: By using bioinformatics methods, we identified six EMERDEGs hub genes (IL6R, TNF, MAPK13, ELANE, PLAUR, ABCA1) and verified them using RT-qPCR. Functional enrichment analysis revealed that these genes were primarily associated with inflammatory response, chemokine production, and cellular energy metabolism. Further, we identified candidate drugs as potential treatments for LDH. Additionally, in immune infiltration analysis, the abundance of activated dendritic cells, neutrophils, and gamma delta T cells varied significantly between the LDH group and Control group. The scRNA-seq analysis showed that these hub genes were mainly expressed in chondrocyte-like cells. Conclusions: The identified EMERDEG hub genes and pathways offer novel insights into the molecular mechanisms underlying LDH and suggest potential therapeutic targets. Full article

Mechanical stress is known to be a pivotal risk factor in the development of OA. However, the involvement of repetitive compressive loading in mitochondrial dysfunction in chondrocytes remains unclear. The aim of this study was to investigate whether physiologic levels of repetitive mechanical force affect the regulation of energy metabolism and activities of mitochondrial function regulators, sirtuin 1 and nicotinamide adenine dinucleotide (NAD) in chondrocytes, and to clarify any correlation with chondrocyte catabolic activity. Repetitive physiological mechanical stress was applied in a 3D chondrocyte-collagen scaffold construct, and the 3D cultured tissues were collected at different time points by collagenase treatment to collect cellular proteins. Changes in chondrocyte activity (cell proliferation, MMP-13 production), energy metabolism regulator levels (sirtuin 1), mitochondrial function (ATP production, NAD level), and the expression level of the osteogenic and hypertrophic chondrogenic transcription factor, runt-related transcription factor 2 (Runx2), were measured. Treatment with repetitive compressive loading resulted in no significant change in the cell viability of chondrocytes. In the repetitive mechanical loading group, there were statistically significant increases in MMP-13 production and expression of both sirtuin 1 and Runx2 in chondrocytes relative to the non-loading control group. Furthermore, ATP production and NAD activity in mitochondria decreased in the repetitive mechanical loading group. Our present study reveals that in chondrocytes, repetitive compressive loading accelerated sirtuin activation, which requires and consumes NAD within mitochondria, leading to a decrease of NAD and ultimately in reduced mitochondrial ATP production. Additionally, since sirtuin 1 is known to positively regulate Runx2 activity in chondrocytes, the activation of sirtuin 1 by repetitive load stimulation may induce an increase in the expression of Runx2, which promotes the expression of MMP-13, and subsequently enhances MMP-13 production. Our findings indicate that repetitive compression loading-mediated mitochondrial dysfunction plays a pivotal role in the progression of OA, primarily by driving the downregulation of ATP production and promoting the expression of the matrix-degrading enzyme MMP-13. Full article

Osteoarthritis (OA) is a long-term degenerative condition of the joints, characterized by persistent inflammation, progressive cartilage breakdown, and impaired mitochondrial function. Recent studies have shown that hyperactivation of the mTORC1 pathway and metabolic reprogramming of chondrocytes contribute to disease progression. Nitazoxanide (NTZ), an oral antiparasitic agent approved by the Food and Drug Administration, has shown anti-inflammatory and mitochondrial protective effects in various disease situations; despite this, its application in osteoarthritis has yet to be fully investigated. Here, we assessed the therapeutic efficacy of NTZ using IL-1β-stimulated primary chondrocytes derived from patients with OA. NTZ substantially reduced the expression of proinflammatory cytokines and matrix metalloproteinases, restored mitochondrial membrane potential, and reduced mitochondrial reactive oxygen species levels. NTZ also effectively reversed IL-1β-induced glycolytic metabolic changes by inhibiting glucose uptake and GLUT1 expression. Mechanistically, NTZ inhibited the activation of the mTORC1 pathway and substantially increased AMPK phosphorylation. The siRNA-mediated AMPK knockdown negated NTZ-induced mitochondrial and metabolic improvements, suggesting that AMPK is a key upstream regulator of the protective actions of NTZ. NTZ can, therefore, effectively inhibit inflammatory metabolic reprogramming and mitochondrial dysfunction in OA chondrocytes through AMPK-dependent mTORC1 signaling inhibition, highlighting its potential as a disease-modifying therapy for OA. Full article

Background: Denosumab, a receptor activator of nuclear factor kappa-Β ligand (RANKL) inhibitor, demonstrates therapeutic effects beyond traditional osteoporosis management through the RANK/RANKL/osteoprotegerin pathway. Methods: This narrative review analyzed 37 studies (2018–2024) examining denosumab’s broader physiological effects and clinical applications. Results: Long-term safety data spanning 10 years showed sustained fracture prevention efficacy with a favorable benefit/risk profile. Compared to bisphosphonates, denosumab demonstrated superior outcomes in bone mineral density improvement and fracture risk reduction, particularly in elderly and frail populations. It enhanced muscular function by improving appendicular lean mass and grip strength while reducing fall risk. The drug showed potential cardiovascular benefits through its effects on cardiac and smooth muscle function. Notably, denosumab use was associated with reduced Type II diabetes mellitus risk through improved glucose metabolism. Additionally, it demonstrated promise in osteoarthritis treatment by suppressing osteoclast activity and chondrocyte apoptosis. While there are multisystem benefits, vigilance is required regarding adverse events, including hypocalcemia, infection risk, cutaneous reactions, and osteonecrosis of the jaw. Conclusions: Denosumab exhibits potential benefits in bone and systemic metabolism. Further research is needed to fully understand its therapeutic potential beyond osteoporosis and optimize clinical applications across different populations. Full article

Osteoarthritis (OA) is a chronic and debilitating joint disease characterized by progressive cartilage degeneration for which no definitive cure exists. Conventional management approaches often rely on fragmented and poorly coordinated pharmacological and non-pharmacological interventions that are inconsistently applied throughout the disease course. Persistent controversies regarding the clinical efficacy of chondroprotective agents, frequently highlighted by pharmacovigilance agencies, underscore the need for a structured evidence-based approach. Emerging evidence suggests that synchronizing pharmacotherapy and exercise regimens with circadian biology may optimize therapeutic outcomes by addressing early pathological processes, including low-grade inflammation, oxidative stress, and matrix degradation. Recognizing the influence of the chondrocyte clock on these processes, this study proposes a ‘prototype’ for a novel framework that leverages the circadian rhythm-aligned administration of traditional chondroprotective agents along with tailored, accessible exercise protocols to mitigate cartilage breakdown and support joint function. In addition, this model-based framework emphasizes the interdependence between cartilage chronobiology and time-of-day-dependent responses to exercise, where strategically timed joint activity enhances nutrient and waste exchange, mitigates mitochondrial dysfunction, supports cellular metabolism, and promotes tissue maintenance, whereas nighttime rest promotes cartilage rehydration and repair. This time-sensitive, comprehensive approach aims to slow OA progression, reduce structural damage, and delay invasive procedures, particularly in weight-bearing joints such as the knee and hip. However, significant challenges remain, including inter-individual variability in circadian rhythms, a lack of reliable biomarkers for pharmacotherapeutic monitoring, and limited clinical evidence supporting chronoexercise protocols. Future large-scale, longitudinal trials are critical to evaluate the efficacy and scalability of this rational integrative strategy, paving the way for a new era in OA management. Full article

Ear reconstruction surgeries for congenital deformities and trauma are common, highlighting the need for improved cartilage regeneration. Lactoferrin (LF), a natural and cost-effective protein, is promising due to its anti-inflammatory, antimicrobial, and prochondrogenic properties. This study investigates the effects of LF on the viability, proliferation, and chondrogenesis of rabbit auricular chondrocytes. For in vitro studies, auricular chondrocytes were cultured for three passages, after which 3D pellets were formed. LF significantly increased chondrocyte metabolic activity by 1.5 times at doses of 10 and 500 μg/mL. At passage 3, LF at concentrations of 10 and 100 μg/mL increased cell proliferation rates by 2- and 1.5-fold, respectively. Immunohistochemical staining of the pellets demonstrated that LF at 10 μg/mL increased the amount of sex-determining region Y-Box Transcription Factor 9 (Sox9)+ cells by 30%, while at 100 μg/mL, it doubled the type II collagen deposits. For in vivo studies, a rabbit ear defect model was utilized. On post-operative day 60, the LF-treated group exhibited more mature cartilage regeneration, with a higher density of elastic fibers. By day 90 post-surgery, LF application led to the restoration of normal elastic cartilage throughout the defect. These findings suggest that LF promotes auricular chondrocytes chondrogenesis and could be beneficial for tissue engineering of the elastic cartilage. Full article

Hyaluronic acid (HA) is a key component of synovial fluid as it plays a crucial role in joint physiology. Its biological activity is influenced by molecular weight, local concentration, and persistence in joints. High-molecular-weight HA has a consolidated history of clinical use, whereas little is known about the metabolic effect of low-molecular-weight hyaluronate on cartilage differentiation. This study explores the potential of HA-based nanoparticles (NPs) on chondrocytes differentiation in vitro. Starting from 25 kDa and 250 kDa sodium hyaluronate solutions, two types of NPs were prepared by antisolvent precipitation in ethanol. The resulting NPs were dried in the presence of dipalmitoyl phosphatidylcholine, a natural synovial fluid component, then applied on an in vitro model of horse articular chondrocytes: no toxicity was observed and NPs prepared from 250 kDa HA promoted chondrocyte differentiation to a larger extent with respect to corresponding HA solutions, as evidenced by increased gene expression of chondrogenic markers (Col2a1 and Sox9) and reduced expression of dedifferentiation markers (Col1a1 and Runx2). These findings suggest that HA-based NPs are more effective at promoting the cellular internalization of the molecule and the differentiation of chondrocytes in vitro and could be a promising platform for drug delivery and cartilage repair. Full article

In degenerative joint disease like osteoarthritis (OA), bioactive compounds like resveratrol, epigallocatechin gallate, curcumin, and other polyphenols often target various signalling pathways, including NFκB, TGFβ, and Wnt/β-catenin by executing epigenetic-modifying activities. Epigenetic modulation can target genes of disease pathophysiology via histone modification, promoter DNA methylation, and non-coding RNA expression, some of which are directly involved in OA but have been less explored. OA patients often seek options that can improve the quality of their life in addition to existing treatment with nonsteroidal anti-inflammatory drugs (NSAIDs). Although bioactive and natural compounds exhibit therapeutic potential against OA, several disadvantages loom, like insolubility and poor bioavailability. Nanoformulated bioactive compounds promise a better way to alleviate OA since they also control systemic events, including metabolic, immunological, and inflammatory responses, by modulating host gut microbiota that can regulate OA pathogenesis. Recent data suggest gut dysbiosis in OA. However, limited evidence is available on the role of bioactive compounds as epigenetic and gut modulators in ameliorating OA. Moreover, it is not known whether the effects of polyphenolic bioactive compounds on gut microbial response are mediated by epigenetic modulatory activities in OA. This narrative review highlights the nanotherapeutic strategies utilizing bioactive compounds, reporting their effects on chondrocyte growth, metabolism, and epigenetic modifications in osteoarthritis amelioration. Full article

Osteoarthritis (OA) is a progressive chronic disease affecting the articular joints, leading to pain and disability. Unlike traditional views that primarily link OA to aging, recent understanding portrays it as a multifactorial degenerative disease of the entire joint. Emerging research highlights metabolic and immune dysregulation in OA pathogenesis, emphasizing the roles of obesity, dyslipidemia, and insulin resistance in altering joint homeostasis. Recent studies have increasingly focused on the complex role of white adipose tissue (WAT) in OA. WAT not only serves metabolic functions but also plays a critical role in systemic inflammation through the release of various adipokines. These adipokines, including leptin and adiponectin, have been implicated in exacerbating cartilage erosion and promoting inflammatory pathways within joint tissues. The overlapping global crises of obesity and metabolic syndrome have significantly impacted joint health. Obesity, now understood to contribute to mechanical joint overload and metabolic dysregulation, heightens the risk of developing OA, particularly in the knee. Metabolic syndrome compounds these risks by inducing chronic inflammation and altering macrophage activity within the joints. The multifaceted effects of obesity and metabolic syndrome extend beyond simple joint loading. These conditions disrupt normal joint function by modifying tissue composition, promoting inflammatory macrophage polarization, and impairing chondrocyte metabolism. These changes contribute to OA progression, highlighting the need for targeted therapeutic strategies that address both the mechanical and biochemical aspects of the disease. Recent advances in understanding the molecular pathways involved in OA suggest potential therapeutic targets. Interventions that modulate macrophage polarization, improve chondrocyte function, or normalize adipokine levels could serve as preventative or disease-modifying therapies. Exploring the role of diet, exercise, and pharmacological interventions in modulating these pathways offers promising avenues for reducing the burden of OA. Furthermore, such methods could prove cost-effective, avoiding the increase in access to healthcare. Full article

Ginsenosides, bioactive compounds from the genus Panax, have potential therapeutic effects on diverse ailments, including diabetes. Emerging evidence suggests their involvement in bone metabolism. The present review summarizes the current understanding of the effects of ginsenosides on osteoporosis, periodontal disease, and osteoarthritis. Their mechanisms of action include effects on osteoblasts, osteoclasts, periodontal ligament fibroblasts (PDLFs), and chondrocytes, which are pivotal in maintaining bone, periodontal tissue, and cartilage homeostasis. Ginsenosides may exert their beneficial effects by enhancing PDLF and osteoblast activity, suppressing osteoclast function, augmenting chondrocyte synthesis in the cartilage matrix, and mitigating connective tissue degradation. Moreover, they possess antioxidant, anti-inflammatory, antimicrobial, and anti-pyroptotic properties. Their efficacy in increasing bone density, ameliorating periodontitis, and alleviating osteoarthritis symptoms has been demonstrated in preclinical studies using animal models. In terms of their mechanism of action, ginsenosides modulate cellular differentiation, activity, and key signaling pathway molecules, such as mitogen-activated protein kinases (MAPKs), while also regulating various mediators. Furthermore, the symptomatic relief observed in animal models lends further credence to their therapeutic utility. However, to translate these preclinical findings into clinical practice, rigorous animal and clinical investigations are imperative to ascertain the safety, efficacy, and optimal dosing regimens in human subjects. Full article

Osteoarthritis (OA) is a degenerative joint disease, causing impaired mobility. There are currently no effective therapies other than palliative treatment. Mesenchymal stromal cells (MSCs) and their secreted extracellular vesicles (MSC-EVs) have shown promise in attenuating OA progression, promoting chondral regeneration, and modulating joint inflammation. However, the precise molecular mechanism of action driving their beneficial effects has not been fully elucidated. In this study, we analyzed MSC-EV-treated human OA chondrocytes (OACs) to assess viability, proliferation, migration, cytokine and catabolic protein expression, and microRNA and mRNA profiles. We observed that MSC-EV-treated OACs displayed increased metabolic activity, proliferation, and migration compared to the controls. They produced decreased proinflammatory (Il-8 and IFN-γ) and increased anti-inflammatory (IL-13) cytokines, and lower levels of MMP13 protein coupled with reduced expression of MMP13 mRNA, as well as negative microRNA regulators of chondrogenesis (miR-145-5p and miR-21-5p). In 3D models, MSC-EV-treated OACs exhibited enhanced chondrogenesis-promoting features (elevated sGAG, ACAN, and aggrecan). MSC-EV treatment also reversed the pathological impact of IL-1β on chondrogenic gene expression and extracellular matrix component (ECM) production. Finally, MSC-EV-treated OACs demonstrated the enhanced expression of genes associated with cartilage function, collagen biosynthesis, and ECM organization and exhibited a signature of 24 differentially expressed microRNAs, associated with chondrogenesis-associated pathways and ECM interactions. In conclusion, our data provide new insights on the potential mechanism of action of MSC-EVs as a treatment option for early-stage OA, including transcriptomic analysis of MSC-EV-treated OA, which may pave the way for more targeted novel therapeutics. Full article

Orally administered “tortoiseshell and deer antler gelatin” is a common traditional medicine for patients with osteoporosis or osteoarthritis. From the pepsin-digested gelatin, we previously isolated and identified the osteoblast-stimulating pentapeptide, TSKYR. Its trypsin digestion products include the dipeptide YR, enhancing calcium ion uptake, and tripeptide TSK, resulting in remarkable 30- and 50-fold increases in mineralized nodule area and density in human osteoblast cells. These peptides were chemically synthesized in this study. The composition of deer antler preparations comprises not only proteins and peptides but also a significant quantity of metal ion salts. By analyzing osteoblast growth in the presence of peptide YR and various metal ions, we observed a synergistic effect of calcium and strontium on the effects of YR. Those peptides could also stimulate the growth of C2C12 skeletal muscle cells and human chondrocytes, increasing collagen and glycosaminoglycan content in a three-dimensional environment. The maintenance of bone homeostasis relies on a balance between osteoclasts and osteoblasts. Deer antler peptides were observed to inhibit osteoclast differentiation, as evidenced by ROS generation, tartrate-resistant acid phosphatase (TRACP) activity assays, and gene expression in RAW264.7 cells. In summary, our findings provide a deep understanding of the efficacy of this folk medicine. Full article

Hypoxia-inducible factor-1 (HIF-1) is a heterodimer transcription factor composed of an alpha and a beta subunit. HIF-1α is a master regulator of cellular response to hypoxia by activating the transcription of genes that facilitate metabolic adaptation to hypoxia. Since chondrocytes in mature articular cartilage reside in a hypoxic environment, HIF-1α plays an important role in chondrogenesis and in the physiological lifecycle of articular cartilage. Accumulating evidence suggests interactions between the HIF pathways and the circadian clock. The circadian clock is an emerging regulator in both developing and mature chondrocytes. However, how circadian rhythm is established during the early steps of cartilage formation and through what signaling pathways it promotes the healthy chondrocyte phenotype is still not entirely known. This narrative review aims to deliver a concise analysis of the existing understanding of the dynamic interplay between HIF-1α and the molecular clock in chondrocytes, in states of both health and disease, while also incorporating creative interpretations. We explore diverse hypotheses regarding the intricate interactions among these pathways and propose relevant therapeutic strategies for cartilage disorders such as osteoarthritis. Full article