Interleukin-1beta down-regulates the expression of glucuronosyltransferase I, a key enzyme priming glycosaminoglycan biosynthesis: influence of glucosamine on interleukin-1beta-mediated effects in rat chondrocytes

Effect of glycosaminoglycans on the structure and composition of articular cartilage and bone of broilers

This study aimed to assess the influence of glycosaminoglycan (chondroitin and glucosamine sulfates) supplementation in the diet of broilers on the expression of matrix metallopeptidase 9 (MMP-9) and metallopeptidase inhibitor 2 (TIMP-2) genes, the synthesis of proteoglycans, collagen type II and chondrocytes, bone and cartilage macroscopy, bone mineral densitometry, bone breaking strength and mineral profile. A completely randomized design was carried out in a 3 × 3 factorial scheme (3 levels of chondroitin sulfate: 0.00, 0.05, and 0.10%; and 3 levels of glucosamine sulfate: 0.00, 0.15, and 0.30%), totaling 9 treatments. At 21 and 42 d of age, broilers were slaughtered, and tibias and femurs were collected for evaluation. There was an interaction (P < 0.05) of sulfates for the expression of MMP-9 and its inhibitor TIMP-2 in femur articular cartilage, as well as for the number of chondrocytes, collagen type II and proteoglycans in tibia articular cartilage, bone and cartilage macroscopy and mineral profile (P < 0.05), with better results obtained with the inclusion of chondroitin and/or glucosamine sulfates in the feed. In conclusion, chondroitin and glucosamine sulfates can be used in broiler diets in order to favor the development of the structure of the locomotor system (bones and joints), thus preventing locomotion problems.

Betulinic Acid Attenuates Osteoarthritis via Limiting NLRP3 Inflammasome Activation to Decrease Interleukin-1β Maturation and Secretion

Introduction

Osteoarthritis (OA) is the most common degenerative joint disorder. Prior studies revealed that activation of NLRP3 inflammasome could promote the activation and secretion of interleukin-1β (IL-1β), which has an adverse effect on the progression of OA. Betulinic acid (BA) is a compound extract of birch, whether it can protect against OA and the mechanisms involved are still unknown.

Materials and Methods

In vivo experiments, using gait analysis, ELISA, micro-CT, and scanning electron microscopy (SEM), histological staining, immunohistological (IHC) and immunofluorescence (IF) staining, and atomic force microscopy (AFM) to assess OA progression after intraperitoneal injection of 5 and 15 mg/kg BA in an OA mouse model. In vitro experiments, caspase-1, IL-1β, and the N-terminal fragment of gasdermin D (GSDMD-NT) were measured in bone marrow-derived macrophages (BMDMs) by using ELISA, western blot, and immunofluorescence staining.

Results

We demonstrated that OA progression can be postponed with intraperitoneal injection of 5 and 15 mg/kg BA in an OA mouse model. Specifically, BA postponed DMM-induced cartilage deterioration, alleviated subchondral bone sclerosis, and relieved synovial inflammation. In vitro studies, the activated NLRP3 inflammasome produces mature IL-1β by facilitating the cleavage of pro-IL-1β, and BA could inhibit the activation of NLRP3 inflammasome in BMDMs.

Conclusions

Taken together, our analyses revealed that BA attenuates OA via limiting NLRP3 inflammasome activation to decrease the IL-1β maturation and secretion.

Oral supplementation with fish cartilage hydrolysate in an adult population suffering from knee pain and function discomfort: results from an innovative approach combining an exploratory clinical study and an ex vivo clinical investigation

BACKGROUND

Aging is frequently associated with impairments of the musculoskeletal system and many elderly people experience joint discomfort or pain which might reduce their ability to move and consequently alter their quality of life. A beneficial effect of fish cartilage hydrolysate (FCH) on pain and joint function has recently been shown in an ACLT/pMMx osteoarthritis rat model.

METHODS

We therefore performed an exploratory, non-comparative, multi-centric clinical trial including 33 subjects with moderate knee joint discomfort and loss of functionality to investigate the efficacy of FCH on their algo-functional status. We further determined the potential health benefit of FCH in an original clinical ex vivo study investigating the role of FCH human metabolites on primary human chondrocytes.

RESULTS

FCH significantly improved knee pain and function, as assessed by the Knee injury and Osteoarthritis Outcome Score (KOOS). Moreover, FCH significantly reduced pain at rest and while walking, and patient global assessment (PGA), as assessed by the Visual Analogue Scale (VAS), and improved patients' quality of life (SF-36). FCH metabolites decreased the synthesis of catabolic factors (MMP-13) and pro-inflammatory mediators (NO, PGE2) and limited the inhibitory effect of IL-1β on the synthesis of cartilage matrix components (GAG and collagen).

CONCLUSIONS

Thus, these data provide insights on the mode of action of FCH in humans and contribute to explain how FCH may relieve pain and improve joint function in subjects with knee discomfort. Although these preliminary data need to be confirmed in a randomized controlled trial, they strongly support the potential health benefit of such an active ingredient.

TRIAL REGISTRATION

The study was registered on clinicaltrials.gov with the identifier NCT04420091 (09/06/2020).

Glucosamine use, smoking and risk of incident chronic obstructive pulmonary disease: a large prospective cohort study

Chronic inflammation exerts pleiotropic effects in the aetiology and progression of chronic obstructive pulmonary disease (COPD). Glucosamine is widely used in many countries and may have anti-inflammatory properties. We aimed to prospectively evaluate the association of regular glucosamine use with incident COPD risk and explore whether such association could be modified by smoking in the UK Biobank cohort, which recruited more than half a million participants aged 40-69 years from across the UK between 2006 and 2010. Cox proportional hazards models with adjustment for potential confounding factors were used to calculate hazard ratios (HR) as well as 95 % CI for the risk of incident COPD. During a median follow-up of 8·96 years (interquartile range 8·29-9·53 years), 9016 new-onset events of COPD were documented. We found that the regular use of glucosamine was associated with a significantly lower risk of incident COPD with multivariable adjusted HR of 0·80 (95 % CI, 0·75, 0·85; P < 0·001). When subgroup analyses were performed by smoking status, the adjusted HR for the association of regular glucosamine use with incident COPD were 0·84 (0·73, 0·96), 0·84 (0·77, 0·92) and 0·71 (0·62, 0·80) among never smokers, former smokers and current smokers, respectively. No significant interaction was observed between glucosamine use and smoking status (P_{for interaction} = 0·078). Incident COPD could be reduced by 14 % to 84 % through a combination of regular glucosamine use and smoking cessation.

Glucosamine Use and Risk of Colorectal Cancer: Results from UK Biobank

BACKGROUND

Use of the dietary supplement glucosamine has been associated with reduced risk of colorectal cancer (CRC); however, it remains unclear if the association varies by screening status, time, and other factors.

METHODS

We therefore evaluated these questions in UK Biobank. Multivariable-adjusted Hazard Ratios (HRs) and 95% Confidence Intervals (95% CI) were estimated using Cox proportional hazards regression.

RESULTS

No association was observed between use of glucosamine and risk of CRC overall (HR: 0.94; 95% CI: 0.85-1.04). However, the association varied by screening status (p-interaction:0.05), with an inverse association observed only among never-screened individuals (HR: 0.86; 95% CI: 0.76-0.98). When stratified by study time, an inverse association was observed in early follow-up among those entering the cohort in early years (2006-2008, HR: 0.80; 95% CI: 0.67-0.95). No heterogeneity was observed by age, sex, body mass index, smoking status, or use of non-steroidal anti-inflammatory drugs.

CONCLUSIONS

While there was no association between glucosamine use and CRC overall, the inverse association among never-screened individuals mirrors our observations in prior exploratory analyses of US cohorts. The National Health Service Bowel Cancer Screening Program started in 2006 in England and was more widely implemented across the UK by 2009. In line with this, we observed an inverse association limited to early follow-up in those surveyed 2006-2008, before screening was widely implemented.

IMPACT

These data suggest that unscreened individuals may benefit from use of glucosamine; however, further studies are needed to confirm the interplay of screening and timing.

Investigation of an injectable gold nanoparticle extracellular matrix

Post-traumatic osteoarthritis (PTOA) is a progressive articular degenerative disease that degrades articular cartilage and stimulates apoptosis in chondrocyte cells. An injectable decellularized, extracellular matrix (ECM) scaffold, that might be able to combat the effects of PTOA, was developed where the ECM was conjugated with 20 nm gold nanoparticles (AuNP) and supplemented with curcumin and hyaluronic acid (HA). Porcine diaphragm ECM was decellularized and homogenized; AuNPs were conjugated using chemical crosslinking followed by mixing with curcumin and/or HA. Injection force testing and scanning electron microscopy with energy-dispersive X-ray spectroscopy were utilized to characterize the ECM scaffolds. In vitro testing with L929 murine fibroblasts, equine synovial fibroblasts, and Human Chondrocytes were used to determine biocompatibility, reactive oxygen species (ROS) reduction, and chondroprotective ability. The results demonstrated that conjugation of 20 nm AuNPs to the ECM was successful without significantly altering the physical properties as noted in the low injection force. In vitro work provided evidence of biocompatibility with a propensity to reduce intracellular ROS and an ability to mitigate apoptosis of chondrocyte cells stimulated with IL-1β, a known apoptosis inducing cytokine. It was concluded that an injectable AuNP-ECM may have the ability to mitigate inflammation and apoptosis.

Does glucosamine, chondroitin sulfate, and methylsulfonylmethane supplementation improve the outcome of temporomandibular joint osteoarthritis management with arthrocentesis plus intraarticular hyaluronic acid injection. A randomized clinical trial

The purpose of this study was to compare clinical outcomes obtained with the use of glucosamine, chondroitin sulfate, and methylsulfonylmethane (GCM) supplementation after arthrocentesis plus intraarticular hyaluronic acid (HA) injection. A randomized clinical trial was implemented with adult participants with TMJ-OA who were referred to the author's clinic between February 2014 and May 2015. The sample was entirely composed of patients with TMJ-OA who were treated randomly with a one-session arthrocentesis plus intraarticular HA injection only (control group), or an initial one-session arthrocentesis plus intraarticular HA injection followed by 3 months of GCM supplementation (study group). The predictor variable was management (treatment) technique. The outcome variables were visual analog scale evaluations (masticatory efficiency, pain complaint, joint sound) and mandibular mobility (maximal interincisal opening [MIO], and lateral and protrusive motions of the mandible). The outcome variables were recorded preoperatively and 12 months postoperatively. Thirty-one participants were enrolled in the study. Five were lost during follow-up. The final study sample consisted of 26 participants (age 28.35 ± 10.85 y): 14 in the control group (age 28.71 ± 10.94 y); and 12 in the study group (age 27.92 ± 11.20 y). Pain complaints (p < 0.001) and joint sounds (p = 0.030 for the control group; p = 0.023 for the study group) showed statistically significant decreases. Masticatory efficiency (p < 0.001 for the control group; p = 0.040 for the study group) and lateral mandibular motion (p = 0.040 for the control group; p = 0.004 for study group) showed statistically significant increases in both groups, whereas MIO and protrusive mandibular motion showed no significant changes in either group (p > 0.05). After estimating the differences between the follow-up and baseline outcomes, the mean changes in the primary outcome variables (VAS scores, MIO, and mandibular motion) showed no statistically significant differences between the two groups (p > 0.05). Progressions (reparative remodeling) of hard-tissue TMJ structures were observed on CBCT scans of some participants in both groups. These findings suggested that the use of GCM supplementation after arthrocentesis plus intraarticular HA injection produced no additional clinical benefits or improvements for patients with TMJ-OA compared with arthrocentesis plus intraarticular HA injection alone.

Glucosamine and Chondroitin Use in Relation to C-Reactive Protein Concentration: Results by Supplement Form, Formulation, and Dose

Objectives: Glucosamine and chondroitin supplements have been associated with reduced inflammation, as measured by C-reactive protein (CRP). It is unclear if associations vary by formulation (glucosamine alone vs. glucosamine+chondroitin), form (glucosamine hydrochloride vs. glucosamine sulfate), or dose. Design, Subjects, Setting, Location: The authors evaluated these questions using cross-sectional data collected between 1999 and 2010 on 21,917 US adults, surveyed as part of the National Health and Nutrition Examination Survey (NHANES). Exposures: Glucosamine and chondroitin use was assessed during an in-home interview; exposures include supplement formulation, form, and dose. Outcome/Analysis: CRP was measured using blood collected at interview. Survey-weighted linear regression was used to evaluate the multivariable-adjusted association between exposures and log-transformed CRP. Results: In early years (1999-2004), use of glucosamine (ratio = 0.87; 95% confidence interval [CI] = 0.79-0.96) and chondroitin (ratio = 0.83; 95% CI = 0.72-0.95) was associated with reduced CRP. However, associations significantly varied by calendar time (p-interaction = 0.04 and p-interaction = 0.01, respectively), with associations nonsignificant in later years (ratio = 1.09; 95% CI = 0.94-1.28 and ratio = 1.16; 95% CI = 0.99-1.35, respectively). Consequently, all analyses have been stratified by calendar time. Associations did not significantly differ by formulation in either set of years; however, significant associations were observed for combined use of glucosamine+chondroitin (ratio_early = 0.82; 95% CI = 0.72-0.95; ratio_late = 1.16; 1.00-1.35), but not glucosamine alone. Associations also did not significantly differ by supplement form. Even so, a significant inverse association was observed only for glucosamine sulfate in the early years (ratio = 0.78; 95% CI = 0.64-0.95); no significant association was observed for glucosamine hydrochloride. No significant trends were observed by dose. Conclusions: Although a significant inverse association was observed for glucosamine and chondroitin and CRP in early years, this association did not hold in later years. This pattern held for combined use of glucosamine+chondroitin as well as glucosamine sulfate, although associations did not significantly vary by supplement form, formulation, or dose. Further study is needed to better understand these associations in the context of calendar time.

Absorption of glucosamine is improved by considering circadian rhythm and feeding time in rats

Although many basic and clinical studies have shown that glucosamine (GlcN) improves osteoarthritis, it has not been widely used in the clinic because its bioavailability is only 6%. We investigated the influence of dosing-time factors, which influence pharmacokinetics and food intake in rats to improve its bioavailability. When GlcN was orally administered to rats housed under conditions of free access to food for 12 h or fasting conditions, no significant differences in GlcN concentration were observed in the rat plasma between the two groups. There were no significant differences in the plasma GlcN concentrations among the dosing-time groups when GlcN was orally administered at 4:00, 10:00, 16:00, or 22:00 h to rats. However, the plasma concentration in the fasted group was significantly higher than that in the fed group after GlcN was orally administered at 22:00 h in rats and the AUC of the fasted group was 1.7-fold higher than that of the fed group. In conclusion, the pharmacokinetics of GlcN was improved by considering not only food intake but also the circadian rhythm of its transporter, which is a major factor influencing pharmacokinetic changes.

Glutamine Metabolism Is Essential for Stemness of Bone Marrow Mesenchymal Stem Cells and Bone Homeostasis

Skeleton has emerged as an endocrine organ which is both capable of regulating energy metabolism and being a target for it. Glutamine is the most bountiful and flexible amino acid in the body which provides adenosine 5′-triphosphate (ATP) demands for cells. Emerging evidences support that glutamine which acts as the second metabolic regulator after glucose exerts crucial roles in bone homeostasis at cellular level, including the lineage allocation and proliferation of bone mesenchymal stem cells (BMSCs), the matrix mineralization of osteoblasts, and the biosynthesis in chondrocytes. The integrated mechanism consisting of WNT, mammalian target of rapamycin (mTOR), and reactive oxygen species (ROS) signaling pathway in a glutamine-dependent pattern is responsible to regulate the complex intrinsic biological process, despite more extensive molecules are deserved to be elucidated in glutamine metabolism further. Indeed, dysfunctional glutamine metabolism enhances the development of degenerative bone diseases, such as osteoporosis and osteoarthritis, and glutamine or glutamine progenitor supplementation can partially restore bone defects which may promote treatment of bone diseases, although the mechanisms are not quite clear. In this review, we will summarize and update the latest research findings and clinical trials on the crucial regulatory roles of glutamine metabolism in BMSCs and BMSC-derived bone cells, also followed with the osteoclasts which are important in bone resorption.

N-acetyl glucosamine and proteoglycan containing supplement improves the locomotor functions of subjects with knee pain

The aim of this study was to investigate the effect of N-acetyl glucosamine and proteoglycan-containing supplement (NGPS) on knee pain and locomotor functions in middle-aged and elderly persons with knee pain. An open trial was conducted on 19 subjects suffering from knee pain. The subjects, aged (55.6 ± 6.9) years, were given the NGPS tablets, which they must take 3 times per day, that contain 526.5 mg of N-acetyl glucosamine (GlcNAc) and 33.6 mg of proteoglycan for 12 weeks. Subjective pain was evaluated using the Visual Analog Scale (VAS), while the function of the knee with regard to daily operation was evaluated using the Japanese Knee Osteoarthritis Score (JKOM). Walking, stair-climbing and swelling were evaluated using the Japanese Orthopedic Association Score (JOA). These items were evaluated at a baseline, and after 4, 8, and 12 weeks of NGPS treatment. The VAS scores at 8 (p = 0.004) and 12 (p < 0.001) weeks were significantly lower than that at the baseline. The JKOM total score was significantly lower at 8 and 12 weeks (p = 0.001) than that at the baseline. The JOA score in the more painful side of the leg was significantly higher at 12 weeks (p = 0.002) than that at the baseline. The present study reveals that intake of NGPS is effective for relieving knee pain and improving knee function when walking or climbing stairs, swelling and bending or stretching.

[Alflutop - in modern symptom - modifying osteoarthritis therapy]

One of the serious problems during the treatment of osteoarthritis (OA) is the developing of adverse drug events during therapy. Nonsteroidal anti - inflammatory drugs (NSAIDs) are the first drugs with the high incidence and severity of adverse events. This article describes OA treatment strategies approaches for OA are presented using the complex drug Alflutop, which has a composition similar to the human hyaline cartilage. The drug has anti - inflammatory and analgesic effects, normalizes the function of the affected joints, improves the quality of patients' life, also has a structure - modifying effect. Such therapy is safe, well tolerable for patients, and can be used used as a starting complex OA treatment.

Evaluation of the effect of the administration of a glucosamine‑containing supplement on biomarkers for cartilage metabolism in soccer players: A randomized double‑blind placebo‑controlled study

A randomized double‑blind placebo‑controlled clinical study was conducted to evaluate the chondroprotective action of glucosamine on healthy subjects (soccer players) without joint disorders. Collegiate soccer players (n=43) without joint disorders were randomly assigned to receive a glucosamine (2 g/day)‑containing supplement (n=22, glucosamine group) or a placebo (n=21, placebo group) for 16 weeks, and cartilage metabolism was evaluated by analyzing markers for type II collagen degradation urine C‑terminal telopeptide‑II (CTX‑II) and serum collagen type II cleavage (C2C) and synthesis urine C-terminal type II procollagen peptide (CPII). In the initial analysis of all subjects, urine CTX‑II level substantially decreased in the glucosamine group, but not in the placebo group after the intervention for 16 weeks (P=0.05). Moreover, CTX‑II level in the glucosamine group was also significantly lower than that in the placebo group at week 16 during the intervention. In the second analysis, to make the effect of the test supplement more clear, 41 subjects with less variation of exercise loading were evaluated. The results revealed that urine CTX‑II level significantly decreased in the glucosamine group (n=21), but not in the placebo group (n=20) after the intervention (P<0.05). Moreover, CTX‑II levels in the glucosamine group significantly decreased compared with the placebo group after the intervention (P<0.05). Both in the initial and second analyses, serum C2C level significantly decreased in the glucosamine group, but not in the placebo group after the intervention (P<0.05). In contrast, urine CPII level was not significantly changed even after the intervention in both the placebo and glucosamine groups. Importantly, no test supplement‑related adverse events were observed. These observations suggest that oral administration of glucosamine (2 g/day for 16 weeks) exerts a chondroprotective action on healthy subjects (soccer players) without joint disorders. This effect was achieved by improving cartilage metabolism (suppressing type II collagen degradation but maintaining type II collagen synthesis), without causing apparent adverse effects.

Cytokine-induced interleukin-1 receptor antagonist protein expression in genetically engineered equine mesenchymal stem cells for osteoarthritis treatment

BACKGROUND

A combination of tissue engineering methods employing mesenchymal stem cells (MSCs) together with gene transfer takes advantage of innovative strategies and highlights a new approach for targeting osteoarthritis (OA) and other cartilage defects. Furthermore, the development of systems allowing tunable transgene expression as regulated by natural disease-induced substances is highly desirable.

METHODS

Bone marrow-derived equine MSCs were transduced with a lentiviral vector expressing interleukin-1 receptor antagonist (IL-1Ra) gene under the control of an inducible nuclear factor-kappa B-responsive promoter and IL-1Ra production upon pro-inflammatory cytokine stimulation [tumor necrosis factor (TNF)α, interleukin (IL)-1β] was analysed. To assess the biological activity of the IL-1Ra protein that was produced and the therapeutic effect of IL-1Ra-expressing MSCs (MSC/IL-1Ra), cytokine-based two- and three-dimensional in vitro models of osteoarthritis using equine chondrocytes were established and quantitative real-time polymerase chain reaction (PCR) analysis was used to measure the gene expression of aggrecan, collagen IIA1, interleukin-1β, interleukin-6, interleukin-8, matrix metalloproteinase-1 and matrix metalloproteinase-13.

RESULTS

A dose-dependent increase in IL-1Ra expression was found in MSC/IL-1Ra cells upon TNFα administration, whereas stimulation using IL-1β did not lead to IL-1Ra production above the basal level observed in nonstimulated cells as a result of the existing feedback loop. Repeated cycles of induction allowed on/off modulation of transgene expression. In vitro analyses revealed that IL-1Ra protein present in the conditioned medium from MSC/IL-1Ra cells blocks OA onset in cytokine-treated equine chondrocytes and co-cultivation of MSC/IL-1Ra cells with osteoarthritic spheroids alleviates the severity of the osteoarthritic changes.

CONCLUSIONS

Thus, pro-inflammatory cytokine induced IL-1Ra protein expression from genetically modified MSCs might represent a promising strategy for osteoarthritis treatment.

Glucosamine use and risk of colorectal cancer: results from the Cancer Prevention Study II Nutrition Cohort

PURPOSE

Use of glucosamine supplements has been associated with reduced risk of colorectal cancer (CRC) in previous studies; however, information on this association remains limited.

METHODS

We examined the association between glucosamine use and CRC risk among 113,067 men and women in the Cancer Prevention Study II Nutrition Cohort. Glucosamine use was first reported in 2001 and updated every 2 years thereafter. Participants were followed from 2001 through June of 2011, during which time 1440 cases of CRC occurred.

RESULTS

As has been observed in prior studies, current use of glucosamine, modeled using a time-varying exposure, was associated with lower risk of CRC (HR 0.83; 95% CI 0.71-0.97) compared to never use. However, for reasons that are unclear, this reduction in risk was observed for shorter-duration use (HR 0.68; 95% CI 0.52-0.87 for current users with ≤ 2 years use) rather than longer-duration use (HR 0.90; 95% CI 0.72-1.13 for current users with 3 to < 6 years of use; HR 0.99; 95% CI 0.76-1.29 for current users with ≥ 6 years of use).

CONCLUSIONS

Further research is needed to better understand the association between glucosamine use and risk of CRC, and how this association may vary by duration of use.

Glucosamine-modified polyethylene glycol hydrogel-mediated chondrogenic differentiation of human mesenchymal stem cells

Glucosamine (GA) is an important cartilage matrix precursor for the glycosaminoglycan biochemical synthesis, and has positive effects on cartilage regeneration, particularly in osteoarthritis therapy. However, it has not been used as a bioactive group in scaffolds for cartilage repair widely. In this study, we synthesized modified polyethylene glycol (PEG) hydrogel with glucosamine and then encapsulated human bone mesenchymal stem cells (hBMSCs) in the hydrogel to induce the differentiation of hBMSCs into chondrocytes in three-dimensional culture. The GA-modified PEG hydrogels promoted the chondrogenesis of hBMSCs, particularly in the concentration of 5mM and 10mM. The subcutaneous transplantation of 10mM GA-modified hydrogels with hBMSCs formed cartilage-like blocks in vivo for 8weeks. Importantly, with glucosamine increase, the modified hydrogels down-regulated the fibrosis and hypertrophic cartilage markers in protein level. Therefore, glucosamine modified PEG hydrogels facilitated the chondrogenesis of hBMSCs, which might represent a new method for cartilage repair using a tissue-engineering approach.

Evaluation of the effect of salmon nasal proteoglycan on biomarkers for cartilage metabolism in individuals with knee joint discomfort: A randomized double-blind placebo-controlled clinical study

A randomized double-blind placebo-controlled clinical trial was conducted to evaluate the chondroprotective action of salmon nasal cartilage proteoglycan on joint health. The effect of oral administration of proteoglycan (10 mg/day) on cartilage metabolism was evaluated in individuals with knee joint discomfort but without diagnosis of knee osteoarthritis. The average age of patients was 52.6±1.1 years old. The effect of proteoglycan was evaluated by analyzing markers for type II collagen degradation (C1,2C) and synthesis (PIICP), and the ratio of type II collagen degradation to synthesis. The results indicated that the change in C1,2C levels significantly differed in the proteoglycan group compared with the placebo group following 16 weeks intervention among subjects with high levels of knee pain and physical dysfunction (total score of Japan Knee Osteoarthritis Measure ≥41) and subjects with constant knee pain (both P<0.05). There was a greater increase in PIICP levels in the proteoglycan group than the placebo group following intervention, although this difference was not significant in both sets of patients. Thus, the C1,2C/PIICP ratios decreased in the proteoglycan group, whereas they slightly increased in the placebo group following the intervention. Furthermore, no test supplement-related adverse events were observed during the intervention. Therefore, oral administration of salmon nasal cartilage proteoglycan at a dose of 10 mg/day may exert a chondroprotective action in subjects with knee joint discomfort. This effect was achieved by improving cartilage metabolism (reducing type II collagen degradation and enhancing type II collagen synthesis), without causing apparent adverse effects.

Effect of cartilaginous matrix components on the chondrogenesis and hypertrophy of mesenchymal stem cells in hyaluronic acid hydrogels

The microenvironment of the extracellular matrix (ECM) plays a key role in directing the viability and subsequent differentiation of the encapsulated stem cells by the specific integration between the hydrated biomolecules and cell surface receptors. Herein, we developed a hydrogel platform based on hyaluronic acid (HA) that presents cartilage ECM molecules as a form of developmental cues. The hybrid hydrogels were generated by coupling photo-cross-linkable methacrylated HA (MeHA) with selected cartilaginous ECM molecules including chondroitin sulfate (CS) and type I collagen (Col I), and we studied the decoupled function of these cues in regulating the initial chondrogenesis, subsequent hypertrophy, and tissue mineralization by hMSCs. The results indicate upregulated mRNA expression of the chondrogenesis markers in the HA hydrogels that contain Col I or CS, and decreased expression of the hypertrophic markers compared with the control MeHA group. The quantification results also show that glycosaminoglycans accumulation increases in the hybrid hydrogels containing cartilaginous ECM molecules, both in vitro and in vivo. We hypothesize that these additional ECM components in the HA hydrogels further regulate the hMSCs chondrogenesis and hypertrophy by coordination. The understanding obtained in this study may guide biomaterial scaffold design, thereby facilitating manipulation of the differentiation and mineralization of induced hMSCs for application in the repair of different musculoskeletal defects. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2292-2300, 2017.

Use of glucosamine and chondroitin supplements in relation to risk of colorectal cancer: Results from the Nurses' Health Study and Health Professionals follow-up study

Recent epidemiologic evidence has emerged to suggest that use of glucosamine and chondroitin supplements may be associated with reduced risk of colorectal cancer (CRC). We therefore evaluated the association between use of these non-vitamin, non-mineral supplements and risk of CRC in two prospective cohorts, the Nurses' Health Study and Health Professionals Follow-up Study. Regular use of glucosamine and chondroitin was first assessed in 2002 and participants were followed until 2010, over which time 672 CRC cases occurred. Cox proportional hazards regression was used to estimate relative risks (RRs) within each cohort, and results were pooled using a random effects meta-analysis. Associations were comparable across cohorts, with a RR of 0.79 (95% CI: 0.63-1.00) observed for any use of glucosamine and a RR of 0.77 (95% CI: 0.59-1.01) observed for any use of chondroitin. Use of glucosamine in the absence of chondroitin was not associated with risk of CRC, whereas use of glucosamine + chondroitin was significantly associated with risk (RR: 0.77; 95% CI: 0.58-0.999). The association between use of glucosamine + chondroitin and risk of CRC did not change markedly when accounting for change in exposure status over follow-up (RR: 0.75; 95% CI: 0.58-0.96), nor did the association significantly vary by sex, aspirin use, body mass index, or physical activity. The association was comparable for cancers of the colon and rectum. Results support a protective association between use of glucosamine and chondroitin and risk of CRC. Further study is needed to better understand the chemopreventive potential of these supplements.

Glucosamine-containing supplement improves locomotor functions in subjects with knee pain - a pilot study of gait analysis

BACKGROUND

Previously, we demonstrated that glucosamine-containing supplementation was effective for improving locomotor functions, especially walking speed. However, the biomechanical mechanism of efficacy has not been elucidated. This study aimed to address this challenge in subjects with knee pain, using a motion capture system.

METHODS

An open label study was conducted in 30 Japanese subjects with knee pain. The subjects were administered a daily supplement containing 1,200 mg of glucosamine hydrochloride, 60 mg of chondroitin sulfate, 45 mg of type II collagen peptides, 90 mg of quercetin glycosides, 10 mg of imidazole peptides, 1 mg of proteoglycan, and 5 μg of vitamin D (GCQID). The intervention continued for 16 weeks. Efficacy for locomotor functions involving the knee joint was evaluated mainly using the Japanese Knee Osteoarthritis Measure (JKOM) and the 5-question Geriatric Locomotive Function Scale (GLFS-5). To examine the biomechanical mechanism of efficacy for locomotor functions, motions of subjects in a normal walking state were captured. Gait analysis was conducted and efficacy for gait parameters such as normal walking speed, stride length, cadence, and angle of soles was evaluated.

RESULTS

GCQID significantly improved total scores on the JKOM and GLFS-5. In gait analysis, normal walking speed, stride length, and angle of soles at the end of the stance phase were all significantly increased, but cadence did not change significantly during the intervention period. There were significant intercorrelations of changes in normal walking speed, stride length, and angle of soles at the end of the stance phase, and between changes in stride length and total JKOM score.

CONCLUSION

A GCQID supplement may increase walking speed through increased stride length and angle of kicking from the ground during steps, which might be mainly associated with alleviated knee pain.

Evaluation of the effect of N-acetyl-glucosamine administration on biomarkers for cartilage metabolism in healthy individuals without symptoms of arthritis: A randomized double-blind placebo-controlled clinical study

The present study aimed to evaluate the effect of N-acetyl-glucosamine (GlcNAc) on the joint health of healthy individuals without arthritic symptoms. A randomized double-blind placebo-controlled clinical trial was performed to investigate the effect of oral administration of a GlcNAc-containing test supplement (low dose, 500 mg/day and high dose, 1,000 mg/day) on cartilage metabolism in healthy individuals with a mean age of 48.6±1.3 years (range, 23-64 years) by analyzing the ratio of type II collagen degradation to type II collagen synthesis using type II collagen degradation (C2C) and synthesis (PIICP) markers. The results indicated that the changes in C2C/PIICP ratios from the baseline were suppressed in the treated with low and high doses of GlcNAc, compared with the placebo group at week 16 during intervention. To further elucidate the effect of GlcNAc, subjects with impaired cartilage metabolism were evaluated. Notably, the changes in the C2C/PIICP ratios were markedly suppressed in the groups treated with low and high doses of GlcNAc at week 16. Finally, to exclude the effect of heavy body weight on joint loading, subjects weighing <70 kg with impaired cartilage metabolism were analyzed. Notably, the changes in the C2C/PIICP ratios were suppressed in the groups treated with low and high doses of GlcNAc at weeks 12 and 16. No test supplement-related adverse events were observed during or following the intervention. Together, these observations suggest that oral administration of GlcNAc at doses of 500 mg and 1,000 mg/day exhibits a chondroprotective effect on healthy individuals by reducing the C2C/PIICP ratio (relatively decreasing type II collagen degradation and increasing type II collagen synthesis) without any apparent adverse effects.

Structural characterization, molecular modification and hepatoprotective effect of melanin from Lachnum YM226 on acute alcohol-induced liver injury in mice

In this paper, we obtained the possible structural formula of the intracellular melanin of Lachnum YM226 and evaluated the protective effect of this melanin and itsd-glucosamine-modified product on acute alcohol-induced liver injury in mice.

Glucosamine-containing supplement improves locomotor functions in subjects with knee pain: a randomized, double-blind, placebo-controlled study

BACKGROUND

The aim of this study was to investigate the ability of a glucosamine-containing supplement to improve locomotor functions in subjects with knee pain.

METHODS

A randomized, double-blind, placebo-controlled, parallel-group comparative study was conducted for 16 weeks in 100 Japanese subjects (age, 51.8±0.8 years) with knee pain. Subjects were randomly assigned to one of the two supplements containing 1) 1,200 mg of glucosamine hydrochloride, 60 mg of chondroitin sulfate, 45 mg of type II collagen peptides, 90 mg of quercetin glycosides, 10 mg of imidazole peptides, and 5 μg of vitamin D per day (GCQID group, n=50) or 2) a placebo (placebo group, n=50). Japanese Knee Osteoarthritis Measure, visual analog scale score, normal walking speed, and knee-extensor strength were measured to evaluate the effects of the supplement on knee-joint functions and locomotor functions.

RESULTS

In subjects eligible for efficacy assessment, there was no significant group × time interaction, and there were improvements in knee-joint functions and locomotor functions in both groups, but there was no significant difference between the groups. In subjects with mild-to-severe knee pain at baseline, knee-extensor strength at week 8 (104.6±5.0% body weight vs 92.3±5.5% body weight, P=0.030) and the change in normal walking speed at week 16 (0.11±0.03 m/s vs 0.05±0.02 m/s, P=0.038) were significantly greater in the GCQID group than in the placebo group. Further subgroup analysis based on Kellgren-Lawrence (K-L) grade showed that normal walking speed at week 16 (1.36±0.05 m/s vs 1.21±0.02 m/s, P<0.05) was significantly greater in the GCQID group than in the placebo group in subjects with K-L grade I. No adverse effect of treatment was identified in the safety assessment.

CONCLUSION

In subjects with knee pain, GCQID supplementation was effective for relieving knee pain and improving locomotor functions.

Recognition of Immune Response for the Early Diagnosis and Treatment of Osteoarthritis

Osteoarthritis is a common and debilitating joint disease that affects up to 30 million Americans, leading to significant disability, reduction in quality of life, and costing the United States tens of billions of dollars annually. Classically, osteoarthritis has been characterized as a degenerative, wear-and-tear disease, but recent research has identified it as an immunopathological disease on a spectrum between healthy condition and rheumatoid arthritis. A systematic literature review demonstrates that the disease pathogenesis is driven by an early innate immune response which progressively catalyzes degenerative changes that ultimately lead to an altered joint microenvironment. It is feasible to detect this infiltration of cells in the early, and presumably asymptomatic, phase of the disease through noninvasive imaging techniques. This screening can serve to aid clinicians in potentially identifying high-risk patients, hopefully leading to early effective management, vast improvements in quality of life, and significant reductions in disability, morbidity, and cost related to osteoarthritis. Although the diagnosis and treatment of osteoarthritis routinely utilize both invasive and non-invasive strategies, imaging techniques specific to inflammatory cells are not commonly employed for these purposes. This review discusses this paradigm and aims to shift the focus of future osteoarthritis-related research towards early diagnosis of the disease process.

Xylosyltransferase-1 expression is refractory to inhibition by the inflammatory cytokines tumor necrosis factor α and IL-1β in nucleus pulposus cells: novel regulation by AP-1, Sp1, and Sp3

We investigated whether expression of xylosyltransferase-1 (XT-1), a key enzyme in glycosaminoglycan biosynthesis, is responsive to disk degeneration and to inhibition by the inflammatory cytokines tumor necrosis factor α and IL-1β in nucleus pulposus (NP) cells. Analysis of human NP tissues showed that XT-1 expression is unaffected by degeneration severity; XT-1 and Jun, Fos, and Sp1 mRNA were positively correlated. Cytokines failed to inhibit XT-1 promoter activity and expression. However, cytokines decreased activity of XT-1 promoters containing deletion and mutation of the -730/-723 bp AP-1 motif, prompting us to investigate the role of AP-1 and Sp1/Sp3 in the regulation of XT-1 in healthy NP cells. Overexpression and suppression of AP-1 modulated XT-1 promoter activity. Likewise, treatment with the Sp1 inhibitors WP631 and mithramycin A or cotransfection with the plasmid DN-Sp1 decreased XT-1 promoter activity. Inhibitors of AP-1 and Sp1 and stable knockdown of Sp1 and Sp3 resulted in decreased XT-1 expression in NP cells. Genomic chromatin immunoprecipitation analysis showed AP-1 binding to motifs located at -730/-723 bp and -684/-677 bp and Sp1 binding to -227/-217 bp and -124/-114 bp in XT-1 promoter. These results suggest that XT-1 expression is refractory to the disease process and to inhibition by inflammatory cytokines and that signaling through AP-1, Sp1, and Sp3 is important in the maintenance of XT-1 levels in NP cells.

Reticulocytosis in nonanemic dogs: increasing prevalence and potential etiologies

BACKGROUND

An increasing prevalence of reticulocytosis in the absence of anemia (RAA) in dogs has been suspected in recent years.

OBJECTIVES

The objectives were to determine whether prevalence of RAA in our canine population has been increasing over the last years, and to identify potential predisposing factors.

METHODS

The annual prevalence of RAA in adult dogs was determined between 2000 and 2012. Clinical histories and CBC data were analyzed for all dogs, as well as owner response to a questionnaire including information on nutrition and supplements was conducted for dogs with RAA identified between 2011 and 2012. In addition, serum iron concentration (Fe), total iron-binding capacity (TIBC), and percent transferrin saturation (%TS) were determined in 14 dogs with RAA and compared with 8 healthy control dogs.

RESULTS

Reticulocytosis in the absence of anemia was identified in 1035 dogs, with the prevalence increasing since 2006. Dogs with RAA evaluated after 2006 (n = 853) had significantly lower MCV and were more likely to have microcytosis than those prior to 2006 (n = 182). Increased incidence of osteoarthritis was observed in dogs evaluated after 2006, including the dogs studied between 2011 and 2012 (n = 31), and administration of nonsteroidal anti-inflammatory drugs, omega-3 fatty acids, and glucosamine was more common in the latter. Significantly lower mean Fe and %TS, and higher TIBC were found in dogs with RAA compared to unaffected dogs.

CONCLUSIONS

Prevalence of RAA has increased in recent years in our canine population. More ubiquitous use of anti-inflammatory medications and nutraceuticals, associated with increased diagnosis of osteoarthritis should be considered as contributing factors.

Glucosamine protects nucleus pulposus cells and induces autophagy via the mTOR-dependent pathway

Although glucosamine has been suggested to be effective in the treatment of osteoarthritis, its effect on disc degeneration remains unclear. We sought to explore whether glucosamine can activate autophagy in rat nucleus pulposus (NP) cells and protect cells treated with IL-1β or hydrogen peroxide (H2 O2 ). Autophagy in cells was examined by detecting for LC3, Beclin-1, m-TOR, and p70S6K, as well as by analyzing autophagosomes. To inhibit autophagy, 3-methyladenine (3-MA) was used. In the cells treated with IL-1β, the levels of Adamts-4, Mmp-13, aggrecan, and Col2a1 were analyzed by real-time PCR and immunofluorescence. Apoptosis was analyzed by TUNEL. Cell senescence under H2 O2 was revealed by SA-β-Gal staining. Glucosamine could activate autophagy in a dose-dependent manner within 24 h and inhibit the phosphorylation of m-TOR and p70S6K. Autophagy in IL-1β or H2 O2 -treated cells was increased by glucosamine. Glucosamine attenuated the decrease of aggrecan and prevented the apoptosis of the NP cells induced by IL-1β, whereas 3-MA partly reversed these effects. The percentage of SA-β-Gal-positive cells induced by H2 O2 treatment was decreased by glucosamine, accompanied by the decline of p70S6K phosphorylation. Glucosamine protects NP cells and up-regulates autophagy by inhibiting the m-TOR pathway, which might point a potential therapeutic agent for disc degeneration.

Angelica Sinensis polysaccharides stimulated UDP-sugar synthase genes through promoting gene expression of IGF-1 and IGF1R in chondrocytes: promoting anti-osteoarthritic activity

BACKGROUND

Osteoarthritis (OA) is a chronic joints disease characterized by progressive degeneration of articular cartilage due to the loss of cartilage matrix. Previously, we found, for the first time, that an acidic glycan from Angelica Sinensis Polysaccharides (APSs), namely the APS-3c, could protect rat cartilage from OA due to promoting glycosaminoglycan (GAG) synthesis in chondrocytes. In the present work, we tried to further the understanding of ASP-3c's anti-OA activity.

METHODOLOGY/PRINCIPAL FINDINGS

Human primary chondrocytes were treated with APS-3c or/and recombinant human interleukin 1β (IL-1β). It turned out that APS-3c promoted synthesis of UDP-xylose and GAG, as well as the gene expression of UDP-sugar synthases (USSs), insulin like growth factor 1 (IGF1) and IGF1 receptor (IGF1R), and attenuated the degenerative phenotypes, suppressed biosynthesis of UDP-sugars and GAG, and inhibited the gene expression of USSs, IGF1 and IGF1R induced by IL-1β. Then, we induced a rat OA model with papain, and found that APS-3c also stimulated GAG synthesis and gene expression of USSs, IGF1 and IGF1R in vivo. Additionally, recombinant human IGF1 and IGF1R inhibitor NP-AEW541 were applied to figure out the correlation between stimulated gene expression of USSs, IGF1 and IGF1R induced by APS-3c. It tuned out that the promoted GAG synthesis and USSs gene expression induced by APS-3c was mediated by the stimulated IGF1 and IGF1R gene expression, but not through directly activation of IGF1R signaling pathway.

CONCLUSIONS/SIGNIFICANCES

We demonstrated for the first time that APS-3c presented anti-OA activity through stimulating IGF-1 and IGF1R gene expression, but not directly activating the IGF1R signaling pathway, which consequently promoted UDP-sugars and GAG synthesis due to up-regulating gene expression of USSs. Our findings presented a better understanding of APS-3c's anti-OA activity and suggested that APS-3c could potentially be a novel therapeutic agent for OA.

Treatment with SiMiaoFang, an anti-arthritis chinese herbal formula, inhibits cartilage matrix degradation in osteoarthritis rat model

A Chinese herbal preparation, SiMiaoFang (SMF), has been used clinically for treating arthralgia by virtue of its anti-inflammatory and pain-relieving activities. However, no evidence base links SMF to anti-osteoarthritis (OA), particularly its link to inhibiting cartilage matrix degradation. In this study, we undertook a characterization of anti-OA activity of SMF using an in vivo rat model induced by anterior cruciate ligament transection and medial meniscus resection (ACLT+MMx) together with in vitro studies with chondrocytes for further molecular characterization. ACLT+MMx rats were treated with SMF at doses of 0.63, 1.25, and 2.5 grams/kg per day for 6 weeks. SMF treatments significantly inhibited cartilage matrix degradation, as indicated by increasing proteoglycan and collagen content, particularly type II collagen expression in articular cartilage, decreasing CTX-II (collagen type II degradation marker), and increasing CPII (collagen type II synthesis marker) in circulation. Moreover, SMF suppressed synovial inflammation and inhibited release of interleukin-1β (IL-1β) and tumor necrosis factor-α in serum. The levels of serum prostaglandin E₂ and nitric oxide productions were decreased via suppression of the production of cyclooxygenase-2 and inducible nitric oxide synthase, respectively. Importantly, SMF interfered with OA-augmented expression of matrix metalloproteinases (MMPs) -3 and -13 and aggrecanases (ADAMTS) -4 and -5, which are considered to be key enzymes in cartilage matrix degradation, and simultaneously augmented OA-reduced tissue inhibitors of metalloproteinases (TIMPs) -1 and -3 expression in the joints. The largest changes in these parameters were found at the highest dose. Meanwhile, SMF significantly decreased MMP-3 and -13 and increased TIMP-1 and -3 at mRNA and protein levels in IL-1β-induced chondrocytes. These findings provide the first evidence that SMF effectively treats OA by inhibiting cartilage matrix degradation.

Effects of glucosamine and risedronate alone or in combination in an experimental rabbit model of osteoarthritis

Background

The osteoarthritis (OA) treatment in humans and in animals is a major orthopaedic challenge because there is not an ideal drug for preserving the joint structure and function. The aim of this study was to assess the effects of the treatment with oral glucosamine and risedronate alone or in combination on articular cartilage, synovial membrane and subchondral bone in an experimental rabbit model of OA. Osteoarthritis was surgically induced on one knee of 32 New Zealand White rabbits using the contralateral as healthy controls. Three weeks later treatments were started and lasted 8 weeks. Animal were divided in four groups of oral treatment: the first group received only saline, the second 21.5 mg/kg/day of glucosamine sulfate, the third 0.07 mg/kg/day of risedronate; and the fourth group both drugs simultaneously at the same dosages. Following sacrifice femurs were removed and osteochondral cylinders and synovial membrane were obtained for its histological and micro-CT evaluation.

Results

Sample analysis revealed that the model induced osteoarthritic changes in operated knees. OA placebo group showed a significant increase in cartilage thickness respect to the control and inflammatory changes in synovial membrane; whereas subchondral bone structure and volumetric bone mineral density remained unchanged. All the treated animals showed an improvement of the cartilage swelling independent of the drug used. Treatment with glucosamine alone seemed to have no effect in the progression of cartilage pathology while risedronate treatment had better results in superficial fibrillation and in resolving the inflammatory changes of the tissues, as well as modifying the orientation of trabecular lattice. The combination of both compounds seemed to have additive effects showing better results than those treated with only one drug.

Conclusions

The results of this animal study suggested that glucosamine sulfate and risedronate treatment alone or in combination may be able to stop cartilage swelling. The risedronate treatment could partially stop the fibrillation and the inflammation of synovial membrane as well as modify the orientation of trabeculae in healthy and in osteoarthritic knees.

Associations between glucosamine and chondroitin supplement use and biomarkers of systemic inflammation

OBJECTIVES

Glucosamine and chondroitin supplements have been shown to have anti-inflammatory properties in both in vitro studies and animal models; however, little is known about these relationships in humans. The VITamins and Lifestyle (VITAL) biomarker study evaluated the associations between use of these supplements and a panel of circulating inflammatory biomarkers.

DESIGN

Study participants included 217 men and women age 50-75 years living in the Seattle metropolitan area. Use of glucosamine and chondroitin supplements was ascertained by home interview/supplement inventory. Inflammation was assessed by using blood and urine collected at the time of home interview. Measures of systemic inflammation included plasma high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-1β, IL-6, IL-8, tumor necrosis factor (TNF)-α, soluble TNF receptors I and II, and urinary prostaglandin E2-metabolite (PGE-M). Multivariate-adjusted linear regression was used to evaluate the associations between supplement use and biomarkers of inflammation.

RESULTS

High users (14 or more pills/week) of chondroitin had 36% lower hsCRP (ratio, 0.64; 95% confidence interval [CI], 0.39-1.04; p for trend=.03) and 27% lower PGE-M (ratio, 0.73; 95% CI, 0.5-0.98; p for trend=.07) than nonusers. Compared with nonusers, high users of glucosamine had 28% lower hsCRP (ratio, 0.72; 95% CI, 0.47-1.08; p for trend=.09) and 24% lower PGE-M (ratio, 0.76; 95% CI, 0.59-0.97; p for trend=0.10). Use of glucosamine and chondroitin supplements was not associated with the other markers of inflammation.

CONCLUSIONS

These results support prior research suggesting that use of glucosamine and chondroitin is associated with reduced hsCRP and PGE2, but further work is needed to more definitively evaluate the anti-inflammatory potential of these supplements.

Specialty supplement use and biologic measures of oxidative stress and DNA damage

BACKGROUND

Oxidative stress and resulting cellular damage have been suggested to play a role in the etiology of several chronic diseases, including cancer and cardiovascular disease. Identifying factors associated with reduced oxidative stress and resulting damage may guide future disease-prevention strategies.

METHODS

In the VITamins And Lifestyle (VITAL) biomarker study of 209 persons living in the Seattle area, we examined the association between current use of several specialty supplements and oxidative stress, DNA damage, and DNA repair capacity. Use of glucosamine, chondroitin, fish oil, methylsulfonylmethane (MSM), coenzyme Q10 (CoQ10), ginseng, ginkgo, and saw palmetto was ascertained by a supplement inventory/interview, whereas the use of fiber supplements was ascertained by questionnaire. Supplements used by more than 30 persons (glucosamine and chondroitin) were evaluated as the trend across number of pills/week (non-use, <14 pills/week, 14+ pills/week), whereas less commonly used supplements were evaluated as use/non-use. Oxidative stress was measured by urinary 8-isoprostane and PGF2α concentrations using enzyme immunoassays (EIA), whereas lymphocyte DNA damage and DNA repair capacity were measured using the Comet assay. Multivariate-adjusted linear regression was used to model the associations between supplement use and oxidative stress/DNA damage.

RESULTS

Use of glucosamine (Ptrend: 0.01), chondroitin (Ptrend: 0.003), and fiber supplements (P: 0.01) was associated with reduced PGF2α concentrations, whereas CoQ10 supplementation was associated with reduced baseline DNA damage (P: 0.003).

CONCLUSIONS

Use of certain specialty supplements may be associated with reduced oxidative stress and DNA damage.

IMPACT

Further research is needed to evaluate the association between specialty supplement use and markers of oxidative stress and DNA damage.

Effect of Angelica sinensis Polysaccharides on Osteoarthritis In Vivo and In Vitro: A Possible Mechanism to Promote Proteoglycans Synthesis

This study investigated the effect of Angelica sinensis polysaccharides (APS-3c) on rat osteoarthritis (OA) model in vivo and rat interleukin-1-beta- (IL-1β-) stimulated chondrocytes in vitro. APS-3c was administrated into rat OA knee joints and had protective effects on rat OA cartilage in vivo. Primary rat articular chondrocytes were cotreated with APS-3c and IL-1β   in vitro. 2~50 μg/mL APS-3c had no effect on chondrocytes viability, whereas it increased the proteoglycans (PGs) synthesis inhibited by IL-1β. Microarray analysis showed that the significant changes were concentrated in the genes which were involved in PGs synthesis. RT-PCR confirmed that treatment with APS-3c increased the mRNA expression of aggrecan and glycosyltransferases (GTs) inhibited by IL-1β but did not affect the mRNA expression of matrix-degrading enzymes. These results indicate that APS-3c can improve PGs synthesis of chondrocytes on rat OA model in vivo and IL-1β-stimulated chondrocytes in vitro, which is due to the promotion of the expression of aggrecan and GTs involved in PGs synthesis but not the inhibition of the expression of matrix-degrading enzymes. Our findings suggest the clinical relevance of APS-3c in the prospective of future alternative medical treatment for OA.

Regulation of xylosyltransferase I gene expression by interleukin 1β in human primary chondrocyte cells: mechanism and impact on proteoglycan synthesis

Xylosyltransferase I (XT-I) is an essential enzyme of proteoglycan (PG) biosynthesis pathway catalyzing the initial and rate-limiting step in glycosaminoglycan chain assembly. It plays a critical role in the regulation of PG synthesis in cartilage; however, little is known about underlying mechanism. Here, we provide evidence that, in human primary chondrocytes, IL-1β regulates XT-I gene expression into an early phase of induction and a late phase of down-regulation. Based on promoter deletions, the region up to -850 bp was defined as a major element of XT-I gene displaying both constitutive and IL-1β-regulated promoter activity. Point mutation and signaling analyses revealed that IL-1β-induced promoter activity is achieved through AP-1 response elements and mediated by SAP/JNK and p38 signaling pathways. Transactivation and chromatin immunoprecipitation assays indicated that AP-1 is a potent transactivator of XT-I promoter and that IL-1β-induced activity is mediated through increased recruitment of AP-1 to the promoter. Finally, we show that Sp3 is a repressor of XT-I promoter and bring evidence that the repressive effect of IL-1β during the late phase is mediated through Sp3 recruitment to the promoter. This suggests that modulation of Sp3 in cartilage could prevent IL-1β inhibition of PG synthesis and limit tissue degradation.

Incomplete elongation of the chondroitin sulfate linkage region on aggrecan and response to interleukin-1β

Aggrecan is the prominent proteoglycan in cartilage and is modified with approximately 100 chondroitin sulfate (CS) chains through a tetrasaccharide linkage structure. In osteoarthritis (OA), the viscoelastic properties of cartilage are compromised on both the quantity and integrity of aggrecan core protein expressed as well as reduced overall CS chain length. Herein, we postulated that chronic low-level inflammation may also contribute to OA progression by promoting regulatory mechanisms in early CS biosynthesis that yield incomplete linkage structures on aggrecan. To test this idea, chondrocytes extracted from human tali were cultured in alginate beads and challenged with 5 ng/mL IL-1β as a model for chronic inflammation leading to OA progression. Novel mass spectrometry-based methods were devised to detect and quantify partially elongated linkage structures relative to control cultures. The total mole fraction of unelongated xylose residues per aggrecan was significantly less (p = 0.03) after IL-1β treatment compared to control cultures, with unelongated xylose residues constituting between 6% and 12% of the fraction of total CS measured. A portion (<1%) of the partially elongated linkage structures was found to be either phosphorylated or sulfated. These results establish quantitative mass spectrometry as a very sensitive and effective platform for evaluating truncated proteoglycan linkage structures. Our observations using this method suggest a possible role for aberrant linkage structure elongation in OA progression.

Smad3 controls β-1,3-glucuronosyltransferase 1 expression in rat nucleus pulposus cells: implications of dysregulated expression in disc disease

OBJECTIVE

To study the regulation of expression of β-1,3-glucuronosyltransferase 1 (GlcAT-1), an important regulator of glycosaminoglycan (GAG) synthesis, by Smad3 in nucleus pulposus (NP) cells.

METHODS

GlcAT-1 expression was examined in rat NP and anulus fibrosus (AF) cells treated with transforming growth factor β (TGFβ). The effects of Smad signaling and Smad suppression on GlcAT-1 were examined in rat NP cells. GlcAT-1 expression was analyzed in the discs of Smad3-null mice and in degenerated human NP tissue.

RESULTS

TGFβ increased the expression of GlcAT-1 in rat NP but not rat AF cells. Suppression of GlcAT-1 promoter activity was evident with dominant-negative ALK-5 (DN-ALK-5). Cotransfection with Smad3 strongly induced promoter activity independent of TGFβ. Bioinformatics analysis indicated the presence of several Smad binding sites in the promoter; deletion analysis showed that the region between -274 and -123 bp was required for Smad3 response. DN-Smad3, Smad 3 small interfering RNA, and Smad7 strongly suppressed basal as well as TGFβ-induced promoter activity. Induction of promoter activity by Smad3 was significantly blocked by DN-Smad3; Smad7 had a very small effect. Lentiviral transduction of NP cells with short hairpin RNA Smad3 resulted in a decrease in GlcAT-1 expression and accumulation of GAG. Compared to wild-type mice, significantly lower expression of GlcAT-1 was seen in the discs of Smad3-null mice. Analysis of degenerated human NP tissue specimens showed no positive correlation between GlcAT-1 and TGFβ expression. Moreover, isolated cells from degenerated human tissue showed a lack of induction of GlcAT-1 expression following TGFβ treatment, suggesting an altered response.

CONCLUSION

Our findings demonstrate that in healthy NP cells, the TGFβ-Smad3 axis serves as a regulator of GlcAT-1 expression. However, an altered responsiveness to TGFβ during disc degeneration may compromise GAG synthesis.

Immunopathogenesis of osteoarthritis

Even though osteoarthritis (OA) is mainly considered as a degradative condition of the articular cartilage, there is increasing body of data demonstrating the involvement of all branches of the immune system. Genetic, metabolic or mechanical factors cause an initial injury to the cartilage resulting in release of several cartilage specific auto-antigens, which trigger the activation of immune response. Immune cells including T cells, B cells and macrophages infiltrate the joint tissues, cytokines and chemokines are released from different kinds of cells present in the joint, complement system is activated, and cartilage degrading factors such as matrix metalloproteinases (MMPs) and prostaglandin E2 (PGE2) are released, resulting in further damage to the articular cartilage. There is considerable success in the treatment of rheumatoid arthritis using anti-cytokine therapies. In OA, however, these therapies did not show much effect, highlighting more complex nature of pathogenesis of OA. This needs the development of more novel approaches to treat OA, which may include therapies that act on multiple targets. Plant natural products have this kind of property and may be considered for future drug development efforts. Here we reviewed the studies implicating different components of the immune system in the pathogenesis of OA.

Oral administration of polymer hyaluronic acid alleviates symptoms of knee osteoarthritis: a double-blind, placebo-controlled study over a 12-month period

This study was conducted to investigate the efficacy of oral hyaluronic acid (HA) administration for osteoarthritis (OA) in knee joints. Sixty osteoarthritic subjects (Kellgren-Lawrence grade 2 or 3) were randomly assigned to the HA or placebo group. The subjects in the HA group were given 200 mg of HA once a day everyday for 12 months, while the subjects in the placebo group were given placebo. The subjects in both groups were requested to conduct quadriceps strengthening exercise everyday as part of the treatment. The subjects' symptoms were evaluated by the Japanese Knee Osteoarthritis Measure (JKOM) score. The symptoms of the subjects as determined by the JKOM score improved with time in both the HA and placebo groups. This improvement tended to be more obvious with the HA group, and this trend was more obvious with the subjects aged 70 years or less. For these relatively younger subjects, the JKOM score was significantly better than the one for the placebo group at the 2nd and 4th months after the initiation of administration. Oral administration of HA may improve the symptoms of knee OA in patients aged 70 years or younger when combined with the quadriceps strengthening exercise.

Crystalline glucosamine sulfate in the management of knee osteoarthritis: efficacy, safety, and pharmacokinetic properties

Glucosamine is an amino monosaccharide and a natural constituent of glycosaminoglycans in articular cartilage. When administered exogenously, it is used for the treatment of osteoarthritis as a prescription drug or a dietary supplement. The latter use is mainly supported by its perception as a cartilage building block, but it actually exerts specific pharmacologic effects, mainly decreasing interleukin 1-induced gene expression by inhibiting the cytokine intracellular signaling cascade in general and nuclear factor-kappa B (NF-kB) activation in particular. As a whole, the use of glucosamine in the management of osteoarthritis is supported by the clinical trials performed with the original prescription product, that is, crystalline glucosamine sulfate. This is the stabilized form of glucosamine sulfate, while other formulations or different glucosamine salts (e.g. hydrochloride) have never been shown to be effective. In particular, long-term pivotal trials of crystalline glucosamine sulfate 1500 mg once daily have shown significant and clinically relevant improvement of pain and function limitation (symptom-modifying effect) in knee osteoarthritis. Continuous administration for up to 3 years resulted in significant reduction in the progression of joint structure changes compared with placebo as assessed by measuring radiologic joint space narrowing (structure-modifying effect). The two effects combined may suggest a disease-modifying effect that was postulated based on an observed decrease in the risk of undergoing total joint replacement in the follow up of patients receiving the product for at least 12 months in the pivotal trials. The safety of the drug was good in clinical trials and in the postmarketing surveillance. Crystalline glucosamine sulfate 1500 mg once daily is therefore recommended in the majority of clinical practice guidelines and was found to be cost effective in pharmacoeconomic analyses. Compared with other glucosamine formulations, salts, or dosage forms, the prescription product achieves higher plasma and synovial fluid concentrations that are above the threshold for a pharmacologically relevant effect, and may therefore justify its distinct therapeutic characteristics.

Evaluation of the effect of methionine and glucosamine on adjuvant arthritis in rats

In the present study, we evaluated the effects of individual administration of methionine or glucosamine (GlcN) and compared with the combined administration of methionine and GlcN on the adjuvant arthritis model of rheumatoid arthritis in rats. Adjuvant arthritis was induced in female Lewis rats by injecting Freund’s complete adjuvant (FCA) into the right hind paws, and methionine (200 mg/kg body weight/day) and/or GlcN (400 mg/kg/day) were orally administered for 21 days. The progression of the adjuvant arthritis was clinically evaluated for characteristic signs and symptoms by employing an arthritis score. The administration of methionine combined with GlcN suppressed the swelling of FCA-uninjected left hind paws and the arthritis score. Additionally, histopathological examination revealed that the combined administration of methionine and GlcN markedly suppressed synovial hyperplasia and the destruction of the cartilage surface and articular meniscus of the knee joints of FCA-injected right hind paws. Furthermore, combined methionine and GlcN administration suppressed the increase in the levels of nitric oxide, prostaglandin E₂ and hyaluronic acid in the plasma of rats with adjuvant arthritis. By contrast, individual administration of methionine or GlcN suppressed arthritis only slightly. These observations suggest that the combined administration of methionine and GlcN is more effective compared with individual administrations of methionine or GlcN in suppressing the progression of adjuvant arthritis (identified as swelling of joints and arthritis score), possibly by synergistically inhibiting synovial inflammation (identified as synovial hyperplasia and the destruction of the cartilage surface and articular meniscus) and the production of inflammatory mediators.

Aciculatin inhibits granulocyte colony-stimulating factor production by human interleukin 1β-stimulated fibroblast-like synoviocytes

The expression of granulocyte colony-stimulating factor (G-CSF), the major regulator of neutrophil maturation, by human fibroblast-like synoviocytes (FLS) can be stimulated by the inflammatory cytokine interleukin-1β (IL-1β). G-CSF is known to contribute to the pathologic processes of destructive arthritis, but the induction mechanism remains unknown. The aims of this study were to identify the signaling pathways involved in IL-1β-stimulated G-CSF production and to determine whether this process was inhibited by aciculatin (8-((2R,4S,5S,6R)-tetrahydro-4,5-dihydroxy-6-methyl-2H-pyran-2-yl)-5-hydroxy-2-(4-hydroxyphenyl)-7-methoxy-4H-chromen-4-one), the major bioactive component of Chrysopogon aciculatus. IL-1β-induced cytokine expression was evaluated by measuring mRNA and protein levels by RT-PCR, ELISA, and Milliplex® assay. Whether aciculatin inhibited IL-1β-stimulated G-CSF expression, and if so, how, were evaluated using western blot assay, an electrophoretic mobility shift assay, and a reporter gene assay. Neutrophil differentiation was determined by Wright-Giemsa staining and flow cytometry. Aciculatin markedly inhibited G-CSF expression induced by IL-1β (10 ng/mL) in a concentration-dependent manner (1-10 µM). In clarifying the mechanisms involved, aciculatin was found to inhibit the IL-1β-induced activation of the IκB kinase (IKK)/IκB/nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) pathways by suppressing the DNA binding activity of the transcription factors NF-κB and activator protein (AP)-1. Furthermore, aciculatin significantly inhibited the G-CSF-mediated phosphorylation of Janus kinase-signal transducer and activator of transcription (JAK-STAT) and Akt and neutrophil differentiation from precursor cells. Our results show that aciculatin inhibits IL-1β-stimulated G-CSF expression and the subsequent neutrophil differentiation, suggesting that it might have therapeutic potential for inflammatory arthritis.

Effect of a dietary supplement containing glucosamine hydrochloride, chondroitin sulfate and quercetin glycosides on symptomatic knee osteoarthritis: a randomized, double-blind, placebo-controlled study

BACKGROUND

Oral glucosamine and chondroitin sulfate, alone and in combination, have been used worldwide for the treatment of osteoarthritis (OA), but their efficacy is controversial. This clinical study was aimed at investigating the potential of a dietary supplement containing glucosamine and chondroitin sulfate in combination with derivatives of quercetin, a naturally occurring flavonoid, (GCQ supplement) for knee OA care.

RESULTS

A randomized, double-blind, placebo-controlled study was conducted in 40 Japanese subjects with symptomatic knee OA. Subjects were randomly assigned to GCQ supplement (1200 mg glucosamine hydrochloride, 60 mg chondroitin sulfate and 45 mg quercetin glycosides per day) or placebo and the treatment and follow-up were continued for 16 weeks. The results of symptomatic efficacy assessment based on Japanese Orthopaedic Association criteria showed that scores for two of the four symptom/function subscales, as well as the aggregate scores, were significantly improved at week 16 or earlier in the GCQ group compared to the placebo group. Moreover, analyses of cartilage metabolism biomarkers showed a trend of improvement in type II collagen synthesis/degradation balance in the GCQ group during follow-up.

CONCLUSION

GCQ supplement was thought to be more effective than placebo in decreasing the intensity of knee OA-associated clinical symptoms.

Is there any scientific evidence for the use of glucosamine in the management of human osteoarthritis?

Glucosamine in its acetylated form is a natural constituent of some glycosaminoglycans (for example, hyaluronic acid and keratan sulfate) in the proteoglycans found in articular cartilage, intervertebral disc and synovial fluid. Glucosamine can be extracted and stabilized by chemical modification and used as a drug or a nutraceutical. It has been approved for the treatment of osteoarthritis (OA) in Europe to promote cartilage and joint health and is sold over the counter as a dietary supplement in the United States. Various formulations of glucosamine have been tested, including glucosamine sulfate and glucosamine hydrochloride. In vitro and in vivo studies have uncovered glucosamine's mechanisms of action on articular tissues (cartilage, synovial membrane and subchondral bone) and justified its efficacy by demonstrating structure-modifying and anti-inflammatory effects at high concentrations. However, results from clinical trials have raised many concerns. Pharmacokinetic studies have shown that glucosamine is easily absorbed, but the current treatment doses (for example, 1,500 mg/day) barely reach the required therapeutic concentration in plasma and tissue. The symptomatic effect size of glucosamine varies greatly depending on the formulation used and the quality of clinical trials. Importantly, the effect size reduces when evidence is accumulated chronologically and evidence for the structure-modifying effects of glucosamine are sparse. Hence, glucosamine was at first recommended by EULAR and OARSI for the management of knee pain and structure improvement in OA patients, but not in the most recent NICE guidelines. Consequently, the published recommendations for the management of OA require revision. Glucosamine is generally safe and although there are concerns about potential allergic and salt-related side effects of some formulations, no major adverse events have been reported so far. This paper examines all the in vitro and in vivo evidence for the mechanism of action of glucosamine as well as reviews the results of clinical trials. The pharmacokinetics, side effects and differences observed with different formulations of glucosamine and combination therapies are also considered. Finally, the importance of study design and criteria of evaluation are highlighted as new compounds represent new interesting options for the management of OA.

Hypoxic regulation of β-1,3-glucuronyltransferase 1 expression in nucleus pulposus cells of the rat intervertebral disc: role of hypoxia-inducible factor proteins

OBJECTIVE

To determine whether hypoxia and hypoxia-inducible factor (HIF) proteins regulate expression of β-1,3-glucuronyltransferase 1 (GlcAT-1), a key enzyme in glycosaminoglycan synthesis in nucleus pulposus cells.

METHODS

Real-time reverse transcriptase-polymerase chain reaction and Western blotting were used to measure GlcAT-1 expression. Transfections were performed to determine the effect of HIF-1α and HIF-2α on GlcAT-1 promoter activity.

RESULTS

Under hypoxic conditions there was an increase in GlcAT-1 expression; a significant increase in promoter activity was seen both in nucleus pulposus cells and in N1511 chondrocytes. We investigated whether HIF controlled GlcAT-1 expression. Suppression of HIF-1α and HIF-2α induced GlcAT-1 promoter activity and expression only in nucleus pulposus cells. Transfection with CA-HIF-1α as well as with CA-HIF-2α suppressed GlcAT-1 promoter activity only in nucleus pulposus cells, suggesting a cell type-specific regulation. Site-directed mutagenesis and deletion constructs were used to further confirm the suppressive effect of HIFs on GlcAT-1 promoter function in nucleus pulposus cells. Although it was evident that interaction of HIF with hypoxia-responsive elements resulted in suppression of basal promoter activity, it was not necessary for transcriptional suppression. This result suggested both a direct and an indirect mode of regulation, possibly through recruitment of a HIF-dependent repressor. Finally, we showed that hypoxic expression of GlcAT-1 was also partially dependent on MAPK signaling.

CONCLUSION

These studies demonstrate that hypoxia regulates GlcAT-1 expression through a signaling network comprising both activator and suppressor molecules, and that this regulation is unique to nucleus pulposus cells.

Effects of Glucosamine and Chondroitin Sulfate on Cartilage Metabolism in OA: Outlook on Other Nutrient Partners Especially Omega-3 Fatty Acids

Osteoarthritis (OA) is a degenerative joint disease that is characterized by increasing loss of cartilage, remodeling of the periarticular bone, and inflammation of the synovial membrane. Besides the common OA therapy with nonsteroidal anti-inflammatory drugs (NSAIDs), the treatment with chondroprotectives, such as glucosamine sulfate, chondroitin sulfate, hyaluronic acid, collagen hydrolysate, or nutrients, such as antioxidants and omega-3 fatty acids is a promising therapeutic approach. Numerous clinical studies have demonstrated that the targeted administration of selected micronutrients leads to a more effective reduction of OA symptoms, with less adverse events. Their chondroprotective action can be explained by a dual mechanism: (1) as basic components of cartilage and synovial fluid, they stimulate the anabolic process of the cartilage metabolism; (2) their anti-inflammatory action can delay many inflammation-induced catabolic processes in the cartilage. These two mechanisms are able to slow the progression of cartilage destruction and may help to regenerate the joint structure, leading to reduced pain and increased mobility of the affected joint.