Zinc Protects Articular Chondrocytes through Changes in Nrf2-Mediated Antioxidants, Cytokines and Matrix Metalloproteinases

Meta-analysis of the Relationship Between Zinc and Copper in Patients with Osteoarthritis

This study aims to explore the relationship between osteoarthritis and the trace elements zinc and copper and to provide a theoretical basis for research on the related mechanisms for the prevention, diagnosis, and treatment of osteoarthritis. We searched all the literature indexed in Web Of Science, Embase, and PubMed as of January 10, 2024, summarized the zinc and copper detection indexes in patients with osteoarthritis, obtained clinical data through literature screening, quality assessment, and data extraction, and analyzed the data using Revman 5.4. A total of 13 papers were included in this study, totaling 7983 study subjects. These were divided into osteoarthritis and healthy control groups. The results from the meta-analysis showed that in patients with osteoarthritis, circulating copper levels, but not zinc levels, were significantly higher compared to healthy individuals. The level of copper in the blood of patients with osteoarthritis is significantly higher than that of healthy people.

Selenium Lessens Osteoarthritis by Protecting Articular Chondrocytes from Oxidative Damage through Nrf2 and NF-κB Pathways

Osteoarthritis (OA) causes joint pain and disability due to the abnormal production of inflammatory cytokines and reactive oxygen species (ROS) in chondrocytes, leading to cell death and cartilage matrix destruction. Selenium (Se) intake can protect cells against oxidative damage. It is still unknown whether Se supplementation is beneficial for OA. This study investigated the effects of Se on sodium iodoacetate (MIA)-imitated OA progress in human chondrocyte cell line (SW1353 cells) and rats. The results showed that 0.3 μM of Se treatment could protect SW1353 cells from MIA-induced damage by the Nrf2 pathway by promoting the gene expression of glutathione-synthesis-related enzymes such as the glutamate-cysteine ligase catalytic subunit, the glutamate-cysteine ligase modifier subunit, and glutathione synthetase. In addition, glutathione, superoxide dismutase, glutathione peroxidase, and glutathione reductase expressions are also elevated to eliminate excessive ROS production. Moreover, Se could downregulate NF-κB, leading to a decrease in cytokines, matrix proteases, and glycosaminoglycans. In the rats, MIA-induced cartilage loss was lessened after 2 weeks of Se supplementation by oral gavage; meanwhile, glutathione synthesis was increased, and the expressions of pro-inflammatory cytokines were decreased. These results suggest that Se intake is beneficial for OA due to its effects of decreasing cartilage loss by enhancing antioxidant capacity and reducing inflammation.

Bone protective effect of sinomenine against monosodium iodoacetate induced knee and hip injury in rat model: an inflammatory pathway

PURPOSE

Osteoarthritis (OA) is a degenerative joint disease which is categorized via destruction of joint cartilage and it also affects the various joints, especially knees and hips. Sinomenine active phytoconstituents isolated from the stem of Sinomenium acutum and already proof anti-inflammatory effect against the arthritis model of rodent. In this experimental protocol, we scrutinized the anti-osteoarthritis effect of sinomenine against monosodium iodoacetate (MIA) induced OA in rats.

METHODS

MIA (3 mg/50 μL) was used for inducing the OA in the rats, and rats received the oral administration of sinomenine (2.5, 5 and 7.5 mg/kg body weight) up to the end of the experimental study (four weeks). The body and organs weight were estimated. Aggrecan, C-terminal cross-linked telopeptide of type II collagen (CTX-II), glycosaminoglycans (GCGs), monocyte chemoattractant protein-1 (MCP-1), Interferon gamma (IFN-γ), antioxidant, inflammatory cytokines, inflammatory mediators and matrix metalloproteinases (MMP) were analyzed.

RESULTS

Sinomenine significantly (P < 0.001) boosted the body weight and reduced the heart weight, but the weight of spleen and kidney remain unchanged. Sinomenine significantly (P < 0.001) reduced the level of nitric oxide, MCP-1 and improved the level of aggrecan, IFN-γ and GCGs. Sinomenine remarkably upregulated the level of glutathione, superoxide dismutase and suppressed the level of malonaldehyde. It effectually modulated the level of inflammatory cytokines and inflammatory mediators and significantly (P < 0.001) reduced the level of MMPs, like MMP-1, 2, 3, 9 and 13.

CONCLUSIONS

Sinomenine is a beneficial active agent for the treatment of OA disease.

Carnosine, Zinc and Copper: A Menage a Trois in Bone and Cartilage Protection

Dysregulated metal homeostasis is associated with many pathological conditions, including arthritic diseases. Osteoarthritis and rheumatoid arthritis are the two most prevalent disorders that damage the joints and lead to cartilage and bone destruction. Recent studies show that the levels of zinc (Zn) and copper (Cu) are generally altered in the serum of arthritis patients. Therefore, metal dyshomeostasis may reflect the contribution of these trace elements to the disease's pathogenesis and manifestations, suggesting their potential for prognosis and treatment. Carnosine (Car) also emerged as a biomarker in arthritis and exerts protective and osteogenic effects in arthritic joints. Notably, its zinc(II) complex, polaprezinc, has been recently proposed as a drug-repurposing candidate for bone fracture healing. On these bases, this review article aims to provide an overview of the beneficial roles of Cu and Zn in bone and cartilage health and their potential application in tissue engineering. The effects of Car and polaprezinc in promoting cartilage and bone regeneration are also discussed. We hypothesize that polaprezinc could exchange Zn for Cu, present in the culture media, due to its higher sequestering ability towards Cu. However, future studies should unveil the potential contribution of Cu in the beneficial effects of polaprezinc.

The influence of zinc and iron intake on osteoarthritis patients' subchondral sclerosis progression: A prospective observational study using data from the osteoarthritis Initiative

Objective

The purpose of this investigation was to elucidate the relationship between the zinc and iron intake and the advancement of subchondral sclerosis among patients with osteoarthritis (OA). The goal was to establish personalized, nutritionally-informed strategies designed to retard the progression of subchondral sclerosis and conserve joint structure.

Methods

For the purposes of this research, we derived data from the Bone Ancillary Study (BAS), a constituent study of the Osteoarthritis Initiative (OAI). The intake of zinc and iron was evaluated via a food frequency questionnaire. Magnetic Resonance Imaging trabecular morphometry was employed to ascertain the microarchitecture of the subchondral bone. For the analysis of collected data, we employed logistic regression along with generalized additive models (GAMs).

Results

The participant cohort was comprised of 474 OA patients (216 females, 258 males, mean [SD] age 64.1[9.2]). Notably, an increment in zinc consumption was linked with a significantly reduced likelihood of deterioration in Tb.N (OR = 0.967, 95 % CI, 0.939-0.996, P-value = 0.026), Tb.Th (OR = 0.958, 95 % CI, 0.929-0.989, P-value = 0.008), and Tb.Sp (OR = 0.967, 95 % CI, 0.939-0.996, P-value = 0.013). An elevation in iron intake seemed to enhance the risk of subchondral sclerosis, as indicated by the GAM. Subgroup analysis revealed an interaction between the effectiveness of zinc intake and factors such as gender, age, radiographic severity, and macronutrient consumption. An increased intake of calcium amplified the beneficial impact of zinc on subchondral sclerosis.

Conclusions

Our findings indicate a positive association between elevated zinc intake and a slowdown in the progression of subchondral sclerosis in OA patients, notably among females, middle-aged individuals, and those with higher calcium and magnesium intake. Conversely, a higher iron intake might intensify subchondral sclerosis. These results suggest that personalized, diet-based interventions focusing on zinc consumption, in tandem with adequate calcium intake, could potentially decelerate the progression of subchondral sclerosis in individuals afflicted with OA.

Drug Delivery Strategies and Nanozyme Technologies to Overcome Limitations for Targeting Oxidative Stress in Osteoarthritis

Oxidative stress is an important, but elusive, therapeutic target for osteoarthritis (OA). Antioxidant strategies that target oxidative stress through the elimination of reactive oxygen species (ROS) have been widely evaluated for OA but are limited by the physiological characteristics of the joint. Current hallmarks in antioxidant treatment strategies include poor bioavailability, poor stability, and poor retention in the joint. For example, oral intake of exogenous antioxidants has limited access to the joint space, and intra-articular injections require frequent dosing to provide therapeutic effects. Advancements in ROS-scavenging nanomaterials, also known as nanozymes, leverage bioactive material properties to improve delivery and retention. Material properties of nanozymes can be tuned to overcome physiological barriers in the knee. However, the clinical application of these nanozymes is still limited, and studies to understand their utility in treating OA are still in their infancy. The objective of this review is to evaluate current antioxidant treatment strategies and the development of nanozymes as a potential alternative to conventional small molecules and enzymes.

Hederagenin Suppresses Inflammation and Cartilage Degradation to Ameliorate the Progression of Osteoarthritis: An In vivo and In vitro Study

Osteoarthritis (OA), a common degenerative joint disease, is characterized by the progressive degradation of articular cartilage and inflammation. Hederagenin (HE) is a pentacyclic triterpenoid saponin extracted from many herb plants. It has anti-inflammatory, anti-lipid peroxidative, anti-cancer, and neuroprotective activities. However, its effect on OA has not been investigated. Our study found that HE may be a potential anti-OA drug. In vitro, HE could suppress extracellular matrix (ECM) degradation via up-regulating aggrecan and Collagen II levels as well as downregulating MMPs and ADAMTS5 levels. It could also reduce proinflammatory and inflammatory cytokines or enzymes production, including TNF-α, IL-6, iNOS, COX-2, NO, and PGE₂. Besides, HE markedly reduced IL-1β-induced C28/I2 cell apoptosis and ROS accumulation. Mechanistically, HE exerted chondroprotective and anti-inflammatory effects by partly inhibiting JAK2/STAT3/MAPK signalling pathway and the crosstalk of the two pathways. Also, HE exhibited anti-apoptotic and anti-oxidative effect via targeting Keap1-Nrf2/HO-1/ROS/Bax/Bcl-2 axis. In vivo, HE significantly reduced monosodium iodoacetate (MIA) induced cartilage destruction of rats with a lower OARSI score and inflammatory cytokine levels, further demonstrating its protective effects in OA progression. These results suggest that HE is a potential compound for the development of drugs to treat OA.

Zinc-loaded whey protein nanoparticles alleviate the oxidative damage and enhance the gene expression of inflammatory mediators in rats

BACKGROUND

Zinc (Zn) is an essential trace element required for the function of the immune system. However, Zn fortification of food has faced some challenges, although excess Zn may be induced obesity and other related. This study aimed to use Zn-loaded whey protein nanoparticles (Zn-WPNPs) to enhance the immunomodulatory activity of Zn in rats treated with CCl₄.

METHODS

Zn was loaded to WPNPs at a level of 14 mg/g. Four experimental groups of male albino Wistar rats were treated for 30 days including the control group, CCl₄-treated group (0.5 ml/100 g b.w), Zn plus CCl₄-treated group (50 mg/kg b.w), and CCl₄ plus Zn-WPNPs-treated group (50 mg/kg b.w). Blood and tissue samples were collected for different assays and histological examinations.

RESULTS

The results revealed that CCl₄ disturbs the serum biochemical, hematological, and immune indicators in different organs besides the liver as a target organ. Animals that received CCl₄ showed a significant increase in oxidative stress markers, cytokines, and the mRNA expression of inflammatory mediators in the lung and spleen accompanied by a significant decrease in the hepatic and renal antioxidant enzymes along with histological changes in the liver, kidney, spleen, and lung. Zn or Zn-WPNPs could improve these parameters and the histological picture of the tested organs and Zn-WPNPs were more effective than Zn alone.

CONCLUSION

WPNPs induced synergistic immune-modulating effects which may control Zn release and may be a suitable candidate to enhance the immune system during any pandemic or the exposure to any chemicals that affect the immune system.

The Role Played by Ferroptosis in Osteoarthritis: Evidence Based on Iron Dyshomeostasis and Lipid Peroxidation

Ferroptosis, a recently discovered regulated cell death modality, is characterised by iron-dependent accumulation of lipid hydroperoxides, which can reach lethal levels but can be specifically reversed by ferroptosis inhibitors. Osteoarthritis (OA), the most common degenerative joint disease, is characterised by a complex pathogenesis involving mechanical overload, increased inflammatory mediator levels, metabolic alterations, and cell senescence and death. Since iron accumulation and oxidative stress are the universal pathological features of OA, the role played by ferroptosis in OA has been extensively explored. Increasing evidence has shown that iron dyshomeostasis and lipid peroxidation are closely associated with OA pathogenesis. Therefore, in this review, we summarize recent evidence by focusing on ferroptotic mechanisms and the role played by ferroptosis in OA pathogenesis from the perspectives of clinical findings, animal models, and cell research. By summarizing recent research advances that characterize the relationship between ferroptosis and OA, we highlight avenues for further research and potential therapeutic targets.

The Impact of Trace Elements on Osteoarthritis

Osteoarthritis (OA) is a progressive degenerative disease characterized by cartilage degradation, synovial inflammation, subchondral sclerosis and osteophyte formation. It has a multifactorial etiology with potential contributions from heredity, endocrine function, abnormal mechanical load and nutrition. Of particular considerations are trace element status. Several trace elements, such as boron and magnesium are essential for normal development of the bone and joint in human. While cadmium correlates with the severity of OA. The present review focuses on the roles of trace elements (boron, cadmium, copper, iron, magnesium, manganese, selenium, zinc) in OA and explores the mechanisms by which they act.

The application prospect of metal/metal oxide nanoparticles in the treatment of osteoarthritis

The current understanding of osteoarthritis is developing from a mechanical disease caused by cartilage wear to a complex biological response involving inflammation, oxidative stress and other aspects. Nanoparticles are widely used in drug delivery due to its good stability in vivo and cell uptake efficiency. In addition to the above advantages, metal/metal oxide NPs, such as cerium oxide and manganese dioxide, can also simulate the activity of antioxidant enzymes and catalyze the degradation of superoxide anions and hydrogen peroxide. Degrading of metal/metal oxide nanoparticles releases metal ions, which may slow down the progression of osteoarthritis by inhibiting inflammation, promoting cartilage repair and inhibiting cartilage ossification. In present review, we focused on recent research works concerning osteoarthritis treating with metal/metal oxide nanoparticles, and introduced some potential nanoparticles that may have therapeutic effects.

Chondrocyte protein co-synthesis network analysis links ECM mechanosensing to metabolic adaptation in osteoarthritis

BACKGROUND

Knee osteoarthritis (OA) is one of the most common structural OA disorders globally. Incomplete understanding of the fundamental biological aspects of osteoarthritis underlies the current lack of effective treatment or disease modifying drugs.

RESEARCH DESIGN AND METHODS

We implemented a systems approach by making use of the statistical network concepts in Weighted Gene Co-expression Analysis to reconstruct the organization of the core proteome network in chondrocytes obtained from OA patients and healthy individuals. Protein modules reflect groups of tightly co-ordinated changes in protein abundance across healthy and OA chondrocytes.

RESULTS

The unbiased systems analysis identified extracellular matrix (ECM) mechanosensing and glycolysis as two modules that are most highly correlated with ΟΑ. The ECM module was enriched in the OA genetic risk factors tenascin-C (TNC) and collagen 11A1 (COL11A1), as well as in cartilage oligomeric matrix protein (COMP), a biomarker associated with cartilage integrity. Mapping proteins that are unique to OA or healthy chondrocytes onto the core interactome, which connects microenvironment sensing and regulation of glycolysis, identified differences in metabolic and anti-inflammatory adaptation.

CONCLUSION

The interconnection between cartilage ECM remodeling and metabolism is indicative of the dynamic chondrocyte states and their significance in osteoarthritis.

Metal-Curcumin Complexes in Therapeutics: An Approach to Enhance Pharmacological Effects of Curcumin

Curcumin, an active component of the rhizome turmeric, has gained much attention as a plant-based compound with pleiotropic pharmacological properties. It possesses anti-inflammatory, antioxidant, hypoglycemic, antimicrobial, neuroprotective, and immunomodulatory activities. However, the health-promoting utility of curcumin is constrained due to its hydrophobic nature, water insolubility, poor bioavailability, rapid metabolism, and systemic elimination. Therefore, an innovative stride was taken, and complexes of metals with curcumin have been synthesized. Curcumin usually reacts with metals through the β-diketone moiety to generate metal–curcumin complexes. It is well established that curcumin strongly chelates several metal ions, including boron, cobalt, copper, gallium, gadolinium, gold, lanthanum, manganese, nickel, iron, palladium, platinum, ruthenium, silver, vanadium, and zinc. In this review, the pharmacological, chemopreventive, and therapeutic activities of metal–curcumin complexes are discussed. Metal–curcumin complexes increase the solubility, cellular uptake, and bioavailability and improve the antioxidant, anti-inflammatory, antimicrobial, and antiviral effects of curcumin. Metal–curcumin complexes have also demonstrated efficacy against various chronic diseases, including cancer, arthritis, osteoporosis, and neurological disorders such as Alzheimer’s disease. These biological activities of metal–curcumin complexes were associated with the modulation of inflammatory mediators, transcription factors, protein kinases, antiapoptotic proteins, lipid peroxidation, and antioxidant enzymes. In addition, metal–curcumin complexes have shown usefulness in biological imaging and radioimaging. The future use of metal–curcumin complexes may represent a new approach in the prevention and treatment of chronic diseases.

S-Equol Protects Chondrocytes against Sodium Nitroprusside-Caused Matrix Loss and Apoptosis through Activating PI3K/Akt Pathway

Osteoarthritis (OA) is a common chronic disease with increasing prevalence in societies with more aging populations, therefore, it is causing more concern. S-Equol, a kind of isoflavones, was reported to be bioavailable and beneficial to humans in many aspects, such as improving menopausal symptoms, osteoporosis and prevention of cardiovascular disease. This study investigated the effects of S-Equol on OA progress in which rat primary chondrocytes were treated with sodium nitroprusside (SNP) to mimic OA progress with or without the co-addition of S-Equol for the evaluation of S-Equol's efficacy on OA. Results showed treatment of 0.8 mM SNP caused cell death, and increased oxidative stress (NO and H₂O₂), apoptosis, and proteoglycan loss. Furthermore, the expressions of MMPs of MMP-2, MMP-3, MMP-9, and MMP-13 and p53 were increased. The addition of 30 μM S-Equol could lessen those caused by SNP. Moreover, S-Equol activates the PI₃K/Akt pathway, which is an upstream regulation of p53 and NO production and is associated with apoptosis and matrix degradation. As a pretreatment of phosphoinositide ₃-kinases (PI₃K) inhibitor, all S-Equol protective functions against SNP decrease or disappear. In conclusion, through PI₃K/Akt activation, S-Equol can protect chondrocytes against SNP-induced matrix degradation and apoptosis, which are commonly found in OA, suggesting S-Equol is a potential for OA prevention.

Gradient bimetallic ion-based hydrogels for tissue microstructure reconstruction of tendon-to-bone insertion

Although gradients play an essential role in guiding the function of tissues, achieving synchronous regeneration of gradient tissue injuries remains a challenge. Here, a gradient bimetallic (Cu and Zn) ion-based hydrogel was first constructed via the one-step coordinative crosslinking of sulfhydryl groups with copper and zinc ions for the microstructure reconstruction of the tendon-to-bone insertion. In this bimetallic hydrogel system, zinc and copper ions could not only act as crosslinkers but also provide strong antibacterial effects and induce regenerative capacity in vitro. The capability of hydrogels in simultaneously promoting tenogenesis and osteogenesis was further verified in a rat rotator cuff tear model. It was found that the Cu/Zn gradient layer could induce considerable collagen and fibrocartilage arrangement and ingrowth at the tendon-to-bone interface. Overall, the gradient bimetallic ion-based hydrogel ensures accessibility and provides opportunities to regenerate inhomogeneous tissue with physiological complexity or interface tissue.

Research status of biodegradable metals designed for oral and maxillofacial applications: A review

The oral and maxillofacial regions have complex anatomical structures and different tissue types, which have vital health and aesthetic functions. Biodegradable metals (BMs) is a promising bioactive materials to treat oral and maxillofacial diseases. This review summarizes the research status and future research directions of BMs for oral and maxillofacial applications. Mg-based BMs and Zn-based BMs for bone fracture fixation systems, and guided bone regeneration (GBR) membranes, are discussed in detail. Zn-based BMs with a moderate degradation rate and superior mechanical properties for GBR membranes show great potential for clinical translation. Fe-based BMs have a relatively low degradation rate and insoluble degradation products, which greatly limit their application and clinical translation. Furthermore, we proposed potential future research directions for BMs in the oral and maxillofacial regions, including 3D printed BM bone scaffolds, surface modification for BMs GBR membranes, and BMs containing hydrogels for cartilage regeneration, soft tissue regeneration, and nerve regeneration. Taken together, the progress made in the development of BMs in oral and maxillofacial regions has laid a foundation for further clinical translation.

Establishing SW1353 Chondrocytes as a Cellular Model of Chondrolysis

Osteoarthritis (OA) is the most common degenerative joint disease characterised by chondrocyte cell death. An in vitro model of chondrocyte cell death may facilitate drug discovery in OA management. In this study, the cytotoxicity and mode of cell death of SW1353 chondrocytes treated with 24 h of OA inducers, including interleukin-1β (IL-1β), hydrogen peroxide (H2O2) and monosodium iodoacetate (MIA), were investigated. The microscopic features, oxidative (isoprostane) and inflammatory markers (tumour necrosis factor-alpha; TNF-α) for control and treated cells were compared. Our results showed that 24 h of H2O2 and MIA caused oxidative stress and a concentration-dependent reduction of SW1353 cell viability without TNF-α level upregulation. H2O2 primarily induced chondrocyte apoptosis with the detection of blebbing formation, cell shrinkage and cellular debris. MIA induced S-phase arrest on chondrocytes with a reduced number of attached cells but without significant cell death. On the other hand, 24 h of IL-1β did not affect the cell morphology and viability of SW1353 cells, with a significant increase in intracellular TNF-α levels without inducing oxidative stress. In conclusion, each OA inducer exerts differential effects on SW1353 chondrocyte cell fate. IL-1β is suitable in the inflammatory study but not for chondrocyte cell death. H2O2 and MIA are suitable for inducing chondrocyte cell death and growth arrest, respectively.

The Associated Regulatory Mechanisms of Zinc Lactate in Redox Balance and Mitochondrial Function of Intestinal Porcine Epithelial Cells

Zinc lactate (ZnLA) is a new organic zinc salt which has antioxidant properties in mammals and can improve intestinal function. This study explored the effects of ZnLA and ZnSO₄ on cell proliferation, Zn transport, antioxidant capacity, mitochondrial function, and their underlying molecular mechanisms in intestinal porcine epithelial cells (IPEC-J2). The results showed that addition of ZnLA promoted cell proliferation, inhibited cell apoptosis and IL-6 secretion, and upregulated the mRNA expression and concentration of MT-2B, ZNT-1, and CRIP, as well as affected the gene expression and activity of oxidation or antioxidant enzymes (e.g., CuZnSOD, CAT, and Gpx1, GSH-PX, LDH, and MDA), compared to ZnSO₄ or control. Compared with the control, ZnLA treatment had no significant effect on mitochondrial membrane potential, whereas it markedly increased the mitochondrial basal OCR, nonmitochondrial respiratory capacity, and mitochondrial proton leakage and reduced spare respiratory capacity and mitochondrial reactive oxygen (ROS) production in IPEC-J2 cells. Furthermore, ZnLA treatment increased the protein expression of Nrf2 and phosphorylated AMPK, but reduced Keap1 and p62 protein expression and autophagy-related genes LC3B-1 and Beclin mRNA abundance. Under H₂O₂-induced oxidative stress conditions, ZnLA supplementation markedly reduced cell apoptosis and mitochondrial ROS levels in IPEC-J2 cells. Moreover, ZnLA administration increased the protein expression of Nrf2 and decreased the protein expression of caspase-3, Keap1, and p62 in H₂O₂-induced IPEC-J2 cells. In addition, when the activity of AMPK was inhibited by Compound C, ZnLA supplementation did not increase the protein expression of nuclear Nrf2, but when Compound C was removed, the activities of AMPK and Nfr2 were both increased by ZnLA treatment. Our results indicated that ZnLA could improve the antioxidant capacity and mitochondrial function in IPEC-J2 cells by activating the AMPK-Nrf2-p62 pathway under normal or oxidative stress conditions. Our novel finding also suggested that ZnLA, as a new feed additive for piglets, has the potential to be an alternative for ZnSO₄.

USP13 mediates PTEN to ameliorate osteoarthritis by restraining oxidative stress, apoptosis and inflammation via AKT-dependent manner

Osteoarthritis is a chronic, systemic and inflammatory disease. However, the pathogenesis and understanding of RA are still limited. Ubiquitin-specific protease 13 (USP13) belongs to the deubiquitinating enzyme (DUB) superfamily, and has been implicated in various cellular events. Nevertheless, its potential on RA progression has little to be investigated. In the present study, we found that USP13 expression was markedly up-regulated in synovial tissue samples from patients with RA, and was down-regulated in human fibroblast-like synoviocytes (H-FLSs) stimulated by interleukin-1β (IL-1β), tumor necrosis factor alpha (TNF-α) or lipopolysaccharide (LPS). We then showed that over-expressing USP13 markedly suppressed inflammatory response, oxidative stress and apoptosis in H-FLSs upon IL-1β or TNF-α challenge, whereas USP13 knockdown exhibited detrimental effects. In addition, USP13-induced protective effects were associated with the improvement of nuclear factor erythroid 2-related factor 2 (Nrf-2) and the repression of Casapse-3. Furthermore, phosphatase and tensin homolog (PTEN) expression was greatly improved by USP13 in H-FLSs upon IL-1β or TNF-α treatment, whereas phosphorylated AKT expression was diminished. In response to IL-1β or TNF-α exposure, nuclear transcription factor κB (NF-κB) signaling pathway was activated, whereas being significantly restrained in H-FLSs over-expressing USP13. Mechanistically, USP13 directly interacted with PTEN. Of note, we found that USP13-regulated cellular processes including inflammation, oxidative stress and apoptotic cell death were partly dependent on AKT activation. Furthermore, USP13 over-expression effectively inhibited osteoclastogenesis and osteoclast-associated gene expression. The in vivo experiments finally confirmed that USP13 dramatically repressed synovial hyperplasia, inflammatory cell infiltration, cartilage damage and bone loss in collagen-induced arthritis (CIA) mice via the same molecular mechanisms detected in vitro. Taken together, these findings suggested that targeting USP13 may provide feasible therapies for RA.

Zinc and Cadmium in the Aetiology and Pathogenesis of Osteoarthritis and Rheumatoid Arthritis

Osteoarthritis (OA) and rheumatoid arthritis (RA) are inflammatory articular conditions with different aetiology, but both result in joint damage. The nutritionally essential metal zinc (Zn²⁺) and the non-essential metal cadmium (Cd²⁺) have roles in these arthritic diseases as effectors of the immune system, inflammation, and metabolism. Despite both metal ions being redox-inert in biology, they affect the redox balance. It has been known for decades that zinc decreases in the blood of RA patients. It is largely unknown, however, whether this change is only a manifestation of an acute phase response in inflammation or relates to altered availability of zinc in tissues and consequently requires changes of zinc in the diet. As a cofactor in over 3000 human proteins and as a signaling ion, zinc affects many pathways relevant for arthritic disease. How it affects the diseases is not just a question of zinc status, but also an issue of mutations in the many proteins that maintain cellular zinc homoeostasis, such as zinc transporters of the ZIP (Zrt-/Irt-like protein) and ZnT families and metallothioneins, and the multiple pathways that change the expression of these proteins. Cadmium interferes with zinc's functions and there is increased uptake under zinc deficiency. Remarkably, cadmium exposure through inhalation is now recognized in the activation of macrophages to a pro-inflammatory state and suggested as a trigger of a specific form of nodular RA. Here, we discuss how these metal ions participate in the genetic, metabolic, and environmental factors that lead to joint destruction. We conclude that both metal ions should be monitored routinely in arthritic disease and that there is untapped potential for prognosis and treatment.

Tranexamic Acid Is Beneficial to Patients Undergoing Open-Wedge High Tibial Osteotomy

The purpose of this study was to investigate the efficacy of tranexamic acid (TXA) in patients undergoing open-wedge high tibial osteotomy (OWHTO). Patients from August 2018 to May 2020 were retrospectively studied. Clinical data were obtained including gender, age, height, weight, body mass index (BMI), smoking, alcohol consumption, hypertension, diabetes, history of aspirin, prepostoperative hematocrit (Hct) and hemoglobin (Hb), thrombotic events, blood transfusion requirement, hospital length of stay, size of osteotomy gap, and wound complications such as wound hematoma and infection. 52 patients were enrolled in the tranexamic acid group (TA group), and 48 patients were enrolled in the nontranexamic acid group (NTA group); there were no significant differences between both groups in terms of gender, age, BMI, preoperative Hb, size of osteotomy gap, incidence of smoking, alcohol consumption, hypertension, diabetes, history of aspirin, thrombotic events, blood transfusion requirement, and wound hematoma and infection. The mean hospital length of stay was 9.4 ± 1.0 days in the TA group and 11.0 ± 1.2 days in the NTA group (P < 0.001), the blood loss was 296.0 ± 128.7 ml in the TA group and 383.3 ± 181.3 ml in the NTA group (P < 0.05), and the postoperative Hb level was 120.8 ± 15.0 g/l in the TA group and 109.5 ± 13.8 g/l in the NTA group (P < 0.001). In conclusion, the administration of TXA is beneficial to patients undergoing OWHTO via decreasing hospital length of stay, reducing blood loss, and maintaining higher postoperative Hb levels.

Cudratricusxanthone O Inhibits H2O2-Induced Cell Damage by Activating Nrf2/HO-1 Pathway in Human Chondrocytes

Osteoarthritis (OA) is a common joint degenerative disease induced by oxidative stress in chondrocytes. Although induced-heme oxygenase-1 (HO-1) has been found to protect cells against oxygen radical damage, little information is available regarding the use of bioactive compounds from natural sources for regulating the HO-1 pathway to treat OA. In this study, we explored the inhibitory effects of cudratricusxanthone O (CTO) isolated from the Maclura tricuspidata Bureau (Moraceae) on H₂O₂-induced damage of SW1353 chondrocytes via regulation of the HO-1 pathway. CTO promoted HO-1 expression by enhancing the translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) into the nucleus without inducing toxicity. Pretreatment with CTO-regulated reactive oxygen species (ROS) production by inducing expression of antioxidant enzymes in H₂O₂-treated cells and maintained the functions of H₂O₂-damaged chondrocytes. Furthermore, CTO prevented H₂O₂-induced apoptosis by regulating the expression of anti-apoptotic proteins. Treatment with the HO-1 inhibitor tin-protoporphyrin IX revealed that these protective effects were exerted due to an increase in HO-1 expression induced by CTO. In conclusion, CTO protects chondrocytes from H₂O₂-induced damages-including ROS accumulation, dysfunction, and apoptosis through activation of the Nrf2/HO-1 signaling pathway in chondrocytes and, therefore, is a potential therapeutic agent for OA treatment.

Enhancing ZnO-NP Antibacterial and Osteogenesis Properties in Orthopedic Applications: A Review

Prosthesis-associated infections and aseptic loosening are major causes of implant failure. There is an urgent need to improve the antibacterial ability and osseointegration of orthopedic implants. Zinc oxide nanoparticles (ZnO-NPs) are a common type of zinc-containing metal oxide nanoparticles that have been widely studied in many fields, such as food packaging, pollution treatment, and biomedicine. The ZnO-NPs have low toxicity and good biological functions, as well as antibacterial, anticancer, and osteogenic capabilities. Furthermore, ZnO-NPs can be easily obtained through various methods. Among them, green preparation methods can improve the bioactivity of ZnO-NPs and strengthen their potential application in the biological field. This review discusses the antibacterial abilities of ZnO-NPs, including mechanisms and influencing factors. The toxicity and shortcomings of anticancer applications are summarized. Furthermore, osteogenic mechanisms and synergy with other materials are introduced. Green preparation methods are also briefly reviewed.

Novel Ultrathin Films Based on a Blend of PEG-b-PCL and PLLA and Doped with ZnO Nanoparticles

In this paper, a novel nanofilm type is proposed based on a blend of poly(ethylene glycol)-block-poly(ε-caprolactone) methyl ether (PEG-b-PCL) and poly(l-lactic acid), doped with zinc oxide nanoparticles (ZnO NPs) at different concentrations (0.1, 1, and 10 mg/mL). All nanofilm types were featured by a thickness value of ∼500 nm. Increasing ZnO NP concentrations implied larger roughness values (∼22 nm for the bare nanofilm and ∼67 nm for the films with 10 mg/mL of NPs), larger piezoelectricity (average d₃₃ coefficient for the film up to ∼1.98 pm/V), and elastic modulus: the nanofilms doped with 1 and 10 mg/mL of NPs were much stiffer than the nondoped controls and nanofilms doped with 0.1 mg/mL of NPs. The ZnO NP content was also directly proportional to the material melting point and crystallinity and inversely proportional to the material degradation rate, thus highlighting the stabilization role of ZnO particles. In vitro tests were carried out with cells of the musculoskeletal apparatus (fibroblasts, osteoblasts, chondrocytes, and myoblasts). All cell types showed good adhesion and viability on all substrate formulations. Interestingly, a higher content of ZnO NPs in the matrix demonstrated higher bioactivity, boosting the metabolic activity of fibroblasts, myoblasts, and chondrocytes and enhancing the osteogenic and myogenic differentiation. These findings demonstrated the potential of these nanocomposite matrices for regenerative medicine applications, such as tissue engineering.

Zinc as a Therapeutic Agent in Bone Regeneration

Zinc is an essential mineral that is required for normal skeletal growth and bone homeostasis. Furthermore, zinc appears to be able to promote bone regeneration. However, the cellular and molecular pathways through which zinc promotes bone growth, homeostasis, and regeneration are poorly understood. Zinc can positively affect chondrocyte and osteoblast functions, while inhibiting osteoclast activity, consistent with a beneficial role for zinc in bone homeostasis and regeneration. Based on the effects of zinc on skeletal cell populations and the role of zinc in skeletal growth, therapeutic approaches using zinc to improve bone regeneration are being developed. This review focuses on the role of zinc in bone growth, homeostasis, and regeneration while providing an overview of the existing studies that use zinc as a bone regeneration therapeutic.

Zinc Deficiency Promotes Testicular Cell Apoptosis in Mice

Zinc (Zn) plays an important role in spermatogenesis, and carbon tetrachloride (CCl₄) induces testicular oxidative damage and cell death. The objective of the present study was to define the effects of Zn deficiency in combination with CCl₄ treatment on testicular apoptosis and the associated mechanisms. Mice were fed the following diets with three different Zn levels for 6 weeks: normal zinc (ZN) diet (30 mg Zn/kg), zinc-deficient (ZD) diet (2 mg Zn/kg), and adequate zinc (ZA) diet (100 mg Zn/kg). Beginning in the third week, CCl₄ was intraperitoneally injected into half of the mice in each diet group six times over 3 weeks. We found that Zn was distributed in various tissues and organs in normal mice and that the zinc content in the testis of normal mice was high. The Zn-deficient diet reduced the zinc concentration in the testis tissue, and the testicular/body weight ratio significantly decreased. Moreover, the TUNEL results proved that CCl₄ stimulation of mice fed with a zinc-deficient diet caused marked apoptosis of testicular cells. Furthermore, the ROS levels in the testes obviously increased after Zn-deficient mice were stimulated with CCl₄, whereas reduced glutathione (GSH) and glutathione peroxidase (GSH-Px) showed reduced activities. In addition, proteins associated with the apoptosis signaling pathway were detected with ELISA kits. P-p53, cleaved caspase-3, cleaved PRAP, p-Bad, p-JNK, p-ERK, and p-NF-κB p65 increased by varying degrees under zinc deficiency or CCl₄ stimulation. All the data indicated that Zn deficiency significantly enhanced the harm to the testis induced by oxidative stress and damage, while CCl₄ stimulation exacerbated the oxidative damage in testicular cells, leading to apoptosis through the activation of p53, MAPK, and NF-κB.

The level of microelements and heterogeneity of joint hypermobility as an endophenotype of undifferentiated connective tissue dysplasia

Objective — The aim of the work was to study serum concentrations of magnesium, copper, zinc, phosphorus and calcium in individuals with undifferentiated connective tissue dysplasia (uCTD) and joint hypermobility (JH) in an isolated and combined state. Material and methods — the concentrations of magnesium, copper, zinc, phosphorus and calcium were measured by the direct colorimetric method in 55 people with joint hypermobility and in 34 – without hypermobility. Results — There were no significant differences between serum concentrations of microelementsin groups with and without JH. In patients with mild and severe uCTD significant decrease in serum magnesium concentrations was noted (U=2.12, p=0.034 and U=3.7, p=0.012). In patients with isolated JH significant serum zinc concentrationdecrease was revealed compared with the control group (U=3.12, p=0.022). Serum magnesium concentrations were reduced in all patients with uCTD and JH; in the groups with isolated dysplasia and combined pathology, the differences reached the level of statistical significance (U=2.78, p=0.024 and U=3.2, p=0.018). Conclusion — The study revealed significant associations of a decrease in serum magnesium concentrations with the development of uCTD in an isolated and combined with JH state and decrease in serum zinc concentrations with the development of isolated JH.

Deoxynivalenol-induced alterations in the redox status of HepG2 cells: identification of lipid hydroperoxides, the role of Nrf2-Keap1 signaling, and protective effects of zinc

Deoxynivalenol (DON) is a type B trichothecenes that is widely contaminating human and animal foods, leading to several toxicological implications if ingested. Induction of oxidative stress and production of lipid peroxides were suggested to be the reasons for DON-induced cytotoxicity. However, detailed and comprehensive profiling of DON-related lipid hydroperoxides was not identified. Furthermore, the mechanisms behind DON-induced cytotoxicity and oxidative stress have received less attention. Zinc (Zn) is an essential element that has antioxidant activities; however, the protective effects of Zn against DON-induced adverse effects were not examined. Therefore, this study was undertaken to investigate DON-induced cytotoxicity and oxidative damage to human HepG2 cell lines. Furthermore, a quantitative estimation for the formed lipid hydroperoxides was conducted using LC-MS/MS. In addition, DON-induced transcriptomic changes on the inflammatory markers and antioxidant enzymes were quantitatively examined using qPCR. The protective effects of Zn against DON-induced cytotoxicity and oxidative stress, the formation of lipid hydroperoxides (LPOOH), and antioxidant status in HepG2 cells were investigated. Finally, the effects of DON and Zn on the Nrf2-Keap1 pathway were further explored. The achieved results indicated that DON caused significant cytotoxicity in HepG2 cells accompanied by significant oxidative damage and induction of the inflammatory markers. Identification of DON-related LPOOH revealed the formation of 22 LPOOH species including 14 phosphatidylcholine hydroperoxides, 5 triacylglycerol hydroperoxides, and 3 cholesteryl ester hydroperoxides. DON caused significant downregulation of Nrf2-regulated antioxidant enzymes. Zn administration led to significant protection of HepG2 cells against DON-induced adverse effects, probably via activation of the Nrf2-Keap1 pathway.

The effects of zinc treatment on matrix metalloproteinases: A systematic review

BACKGROUND

Zinc (Zn) acts as a cofactor of matrix metalloproteinases (MMPs) and is vital for their activity and controlling their expression. Alteration of Zn in the body could affect the expression, activity, and destructive impacts of MMPs.

OBJECTIVE

This systematic review aimed to summarize existing evidence on the effects of Zn treatment on the expression and activity of MMPs.

METHOD

International sources from Pub Med, Scopus and Google Scholar were searched for the original and English-language studies, published up to the end of May 2018.

RESULTS

During the initial search, 179 records were found, and 135 articles of them remained after the exclusion of duplicate articles. 47 studies met the inclusion criteria, after multiple stages of screening and critical reviews of articles.

CONCLUSION

Approximately 62% of the included studies (29 of 47) showed an inhibitory impact of Zn on MMPs production and activities. The inhibitory or stimulatory effect of Zn on MMPs seems to depend on physiological conditions of the cells or animals used, dose of Zn used, and duration of treatment.

Zinc protects chondrocytes from monosodium iodoacetate-induced damage by enhancing ATP and mitophagy

Osteoarthritis (OA) is characterized with articular cartilage degradation, and monosodium iodoacetate (MIA)-treated chondrocyte is the most commonly used model for mimicking OA progression. Zinc protects chondrocytes from MIA-induced damage. Here, we explored the protective effects of 25 μM zinc on 5 μM MIA-treated SW1353 cells (human chondrosarcoma cell line) through the analysis of energy metabolism- and autophagy-related parameters. We found that the exposure of SW1353 cells to MIA decreased ATP levels, expression of glycolysis-related proteins, including glucose transporter 1, hexokinase 2, and pyruvate dehydrogenase E1 component subunit alpha, and the levels of mitochondrial complex I, II, IV, and V subunits of the oxidative phosphorylation pathway. MIA treatment also decreased the expression of autophagy-related proteins, including autophagic elongation protein 5 (ATG5), ATG7, and microtubule-associated protein 1A/1B light chain 3B (LC3-II) and mitophagy-related proteins, including phosphatase and tensin homolog (PTEN)-induced putative kinase 1 (PINK1), ubiquitin, and p62. These results indicate that MIA interferes with energy metabolism and the autophagic clearance of dysfunctional mitochondria (so called mitophagy). Interestingly, zinc exposure could almost completely reverse the effects of MIA, suggesting its potential protective role against OA progression.

The effects of zinc supplementation on clinical response and metabolic profiles in pregnant women at risk for intrauterine growth restriction: a randomized, double-blind, placebo-controlled trial

OBJECTIVE

This investigation was conducted to assess the effects of zinc supplementation on clinical response and metabolic status among pregnant women at risk for intrauterine growth restriction (IUGR).

METHODS

This randomized, double-blind, placebo-controlled, clinical trial was conducted among 52 women at risk for IUGR according to abnormal uterine artery Doppler waveform. Participants were randomly assigned to take either 233 mg zinc gluconate (containing 30 mg zinc) supplements (n = 26) or placebo (n = 26) for 10 weeks from 17 to 27 weeks of gestation. Fasting blood samples were taken at baseline and after the 10-week treatment to quantify related variables.

RESULTS

After the 10-week intervention, taking zinc led to a significant reduction in serum high-sensitivity C-reactive protein (hs-CRP) (β ‒1.17 mg/L; 95% CI, -1.77, -0.57; p < .001) and plasma malondialdehyde (MDA) levels (β -0.23 µmol/L; 95% CI, -0.45, -0.02; p = .03); also a significant rise in total antioxidant capacity (TAC) (β 59.22 mmol/L; 95% CI, 25.07, 93.36; p = .001) was observed in comparison to placebo. In addition, zinc supplementation significantly reduced serum insulin (β -1.33 µIU/mL; 95% CI, -2.00, -0.67; p < .001) and insulin resistance (β -0.30; 95% CI, -0.44, -0.15; p < .001), and significantly increased insulin sensitivity (β 0.008; 95% CI, 0.003, 0.01; p < .001) compared with the placebo. Zinc supplementation did not influence pulsatility index (PI) and other metabolic parameters.

CONCLUSIONS

Overall, zinc supplementation in pregnant women at risk for IUGR had beneficial effects on TAC, MDA, hs-CRP, and insulin metabolism, but did not affect PI and other metabolic profiles.

IL-10 Could Play a Role in the Interrelation between Diabetes Mellitus and Osteoarthritis

The association between osteoarthritis (OA), obesity and metabolic syndrome suggests an interrelation between OA and diabetes mellitus (DM). Little is known about the role of anti-inflammatory cytokine interleukin (IL)-10 in the interrelation between OA and DM. Hence, the effects of IL-10 under hyperglycemia (HG) and hyperinsulinemia (HI) in human articular chondrocytes (hAC) and chondrosarcoma cell line Okayama University Medical School (OUMS)-27 were examined. HAC and OUMS-27, cultured in normoglycemic (NG) and HG conditions were stimulated with insulin and/or IL-10. Cell survival, metabolic activity, proliferation and extracellular matrix (ECM) synthesis were immunocytochemically examined. No significant differences in vitality of hAC neither in pure NG (NG_w/o) nor HG (HG_w/o) conditions were found. Applying HI and/or IL-10 in both conditions reduced significantly the vitality of hAC but not of OUMS-27. HG impaired significantly hAC metabolism. When combined with HI + IL-10 or IL-10 alone it decreased also significantly hAC proliferation compared to NG_w/o. In OUMS-27 it induced only a trend of impaired proliferation compared to NG_w/o. hAC but not OUMS-27 reduced significantly their collagen type (col) I, SOX9 and proteoglycan (PG) synthesis in HG combined with HI +/− IL-10 compared to NG_w/o. IL-10 could not moderate HI and HG effects. In contrast to hAC OUMS-27 showed limited sensitivity as DM model.