Changing Grains for the Prevention and Treatment of Kashin-Beck Disease in Children: a Meta-analysis.

To evaluate the efficacy of changing grains on the prevention and treatment of Kashin-Beck Disease (KBD) in children, community-based trials were acquired from seven electronic databases (up to July 2014). As a result, the methodological quality of the six trials that have been included into our analysis was low. The pooled ORs favoring the prevention and treatment effects of changing grains were 0.15 (95% CI: 0.03-0.70) and 2.13 (95% CI: 1.44-3.16) respectively by meta-analysis. Subgroup analysis demonstrated the pooled OR favoring treatment effect of exchanging grains rather than drying grains both compared with endemic grains. The results showed that changing grains had obvious effects on the prevention and treatment of KBD in children. However, the evidences were limited by the potential biases and confounders. Large and well-designed trials are still needed.

Mitochondrial-related gene expression profiles suggest an important role of PGC-1alpha in the compensatory mechanism of endemic dilated cardiomyopathy.

Keshan disease (KD) is an endemic dilated cardiomyopathy with unclear etiology. In this study, we compared mitochondrial-related gene expression profiles of peripheral blood mononuclear cells (PBMCs) derived from 16 KD patients and 16 normal controls in KD areas. Total RNA was isolated, amplified, labeled and hybridized to Agilent human 4 × 44k whole genome microarrays. Mitochondrial-related genes were screened out by the Third-Generation Human Mitochondria-Focused cDNA Microarray (hMitChip3). Quantitative real-time PCR, immunohistochemical and biochemical parameters related mitochondrial metabolism were conducted to validate our microarray results. In KD samples, 34 up-regulated genes (ratios ≥ 2.0) were detected by significance analysis of microarrays and ingenuity systems pathway analysis (IPA). The highest ranked molecular and cellular functions of the differentially regulated genes were closely related to amino acid metabolism, free radical scavenging, carbohydrate metabolism, and energy production. Using IPA, 40 significant pathways and four significant networks, involved mainly in apoptosis, mitochondrion dysfunction, and nuclear receptor signaling were identified. Based on our results, we suggest that PGC-1alpha regulated energy metabolism and anti-apoptosis might play an important role in the compensatory mechanism of KD. Our results may lead to the identification of potential diagnostic biomarkers for KD in PBMCs, and may help to understand the pathogenesis of KD.

Glucosamine sulphate does not increase extracellular matrix production at low oxygen tension.

Low oxygen tension may change the dependence of chondrocytes on exogenous carbohydrate sources. In this study, we have investigated whether glucosamine sulphate (GS) stimulates proteoglycan synthesis, the mRNA expression of aggrecan and of type II collagen, and UDP-sugar levels in bovine primary chondrocytes under a low oxygen (O(2)) atmosphere. Chondrocytes from bovine femoral condyles were cultivated with or without GS or sulphate at various concentrations in low- (5.5 mM) or high-glucose (25 mM) DMEM under either a 5% or 20% O(2) atmosphere for 2 or 8 days after isolation. The mRNA expression of aggrecan and type II collagen and the synthesis of glycosaminoglycan (GAG) were determined by quantitative real-time reverse transcription with polymerase chain reaction and a [(35)S]-sulphate incorporation assay, respectively. Aggrecan promoter activity was analysed by a dual-luciferase reporter gene assay. Intracellular UDP-N-acetylhexosamines (UDP-HexN), UDP-glucuronic acid and UDP-hexoses were analysed by reversed-phase high-performance liquid chromatography electrospray ionization mass spectrometry. A low (5%) O(2) atmosphere significantly increased GAG synthesis, mRNA expression of aggrecan and of type II collagen and aggrecan promoter activity in bovine primary chondrocytes. A high (1 mM) concentration of GS was required to increase the level of UDP-HexN. However, GS did not increase GAG synthesis, aggrecan promoter activity or mRNA expression of aggrecan and of type II collagen. Interestingly, a 5% O(2) atmosphere increased the level of UDP-HexN in 8-day cultures without GS treatment. Thus, exogenous GS does not change chondrocyte metabolism, whereas a 5% O(2) atmosphere stimulates extracellular matrix production in bovine primary chondrocytes. The balance of UDP-sugars is changed under a 5% O(2) atmosphere for longer culture periods.

Stress-relaxation of human patellar articular cartilage in unconfined compression: prediction of mechanical response by tissue composition and structure.

Mechanical properties of articular cartilage are controlled by tissue composition and structure. Cartilage function is sensitively altered during tissue degeneration, in osteoarthritis (OA). However, mechanical properties of the tissue cannot be determined non-invasively. In the present study, we evaluate the feasibility to predict, without mechanical testing, the stress-relaxation response of human articular cartilage under unconfined compression. This is carried out by combining microscopic and biochemical analyses with composition-based mathematical modeling. Cartilage samples from five cadaver patellae were mechanically tested under unconfined compression. Depth-dependent collagen content and fibril orientation, as well as proteoglycan and water content were derived by combining Fourier transform infrared imaging, biochemical analyses and polarized light microscopy. Finite element models were constructed for each sample in unconfined compression geometry. First, composition-based fibril-reinforced poroviscoelastic swelling models, including composition and structure obtained from microscopical and biochemical analyses were fitted to experimental stress-relaxation responses of three samples. Subsequently, optimized values of model constants, as well as compositional and structural parameters were implemented in the models of two additional samples to validate the optimization. Theoretical stress-relaxation curves agreed with the experimental tests (R=0.95-0.99). Using the optimized values of mechanical parameters, as well as composition and structure of additional samples, we were able to predict their mechanical behavior in unconfined compression, without mechanical testing (R=0.98). Our results suggest that specific information on tissue composition and structure might enable assessment of cartilage mechanics without mechanical testing.

The lack of effect of glucosamine sulphate on aggrecan mRNA expression and (35)S-sulphate incorporation in bovine primary chondrocytes.

Glucosamine and glucosamine sulphate have been promoted as a disease-modifying agent to improve the clinical symptoms of osteoarthritis. The precise mechanism of the action of the suggested positive effect of glucosamine or glucosamine sulphate on cartilage proteoglycans is not known, since the level of glucosamine in plasma remains very low after oral administration of glucosamine sulphate. We examined whether exogenous hexosamines or their sulphated forms would increase steady-state levels of aggrecan and hyaluronan synthase (HAS) or glycosaminoglycan synthesis using Northern blot and (35)S-sulphate incorporation analyses. Total RNA was extracted from bovine primary chondrocytes which were cultured either in 1 mM concentration of glucosamine, galactosamine, mannosamine, glucosamine 3-sulphate, glucosamine 6-sulphate or galactosamine 6-sulphate for 0, 4, 8 and 24 h, or in three different concentrations (control, 100 microM and 1 mM) of glucosamine sulphate salt or glucose for 24 or 72 h. Northern blot assay showed that neither hexosamines nor glucosamine sulphate salt stimulated aggrecan and HAS-2 mRNA expression. Glycosaminoglycan synthesis remained at a control level in the treated cultures, with the exception of mannosamine which inhibited (35)S-sulphate incorporation in low-glucose DMEM treatment. In our culture conditions, hexosamines or their sulphated forms did not increase aggrecan expression or (35)S-sulphate incorporation.

Expression profiles of genes involved in apoptosis and selenium metabolism in articular cartilage of patients with Kashin-Beck osteoarthritis.

Kashin-Beck disease (KBD) is a special type of endemic osteoarthritis. It has been suggested that alterations in selenium metabolism and apoptosis play a role in KBD. However, the underlying molecular mechanism remains largely unclear. We performed a microarray analysis using RNA isolated from cartilages of KBD patients and healthy controls, through Significance Analysis of Microarray (SAM) software. Functional gene networks and crucial molecules associated with differentially expressed genes were investigated via Ingenuity Pathway Analysis (IPA) and hub gene analysis. Quantitative real-time PCR was used to check the validation of chip test. We identified 52 up-regulated apoptosis-related genes and 26 down-regulated selenium-related genes between KBD and controls, and these genes associated with the "MYC-mediated apoptosis signaling pathway". We confirmed the results from array studies with quantitative real-time PCR analysis. Our results suggest that abnormal regulation of selenium metabolism and apoptosis through the MYC mediated signaling pathway contributes to the pathogenesis of KBD, but the relationship between apoptosis gene and selenium gene was not found.

Human articular cartilage proteoglycans are not undersulfated in osteoarthritis.

Chondroitin sulfate is the major constituent of cartilage. Inadequate sulfate availability results in the production of undersulfated proteoglycans. In osteoarthritis, there is a net loss of articular cartilage proteoglycans. Theoretically, it is possible that during the progress of disease undersulfated glycosaminoglycans are synthesized producing proteoglycans with poorer biological properties. In this study, we tested whether in early human osteoarthritic articular cartilage (Mankin's score of 2 and 3) or more advanced disease (Mankin's score over 3), there are proteoglycans that contain a higher relative amount of nonsulfated chondroitin disaccharide isomer in their chondroitin sulfate chains by analyzing the molar ratios of chondroitin sulfate disaccharide isoforms with fluorophore-assisted carbohydrate electrophoresis. Our results indicated that the nonsulfated disaccharide of chondroitin sulfate formed in average only 1-2% of the total chondroitin sulfate. More important, the molar ratio of nonsulfated disaccharide did not appear to be increased in the osteoarthritic articular cartilage. We conclude that undersulfation of articular cartilage proteoglycans is not present in the human osteoarthritic joint.

Undersulfated chondroitin sulfate does not increase in osteoarthritic cartilage.

OBJECTIVE: To test whether there is undersulfation of chondroitin sulfate in osteoarthritic bovine articular cartilage to support the hypothesis that sulfate deficiency is involved with the development of osteoarthritis. METHODS: Cartilage samples from bovine patellae (n = 32) were divided into 3 groups based on their osteoarthritic progression, as assessed by modified Mankin score. Uronic acid contents of the samples were determined. Fragmentation of the proteoglycans due to proteolytic processing was estimated with agarose gel electrophoresis. The molar ratios of chondroitin sulfate isoforms in the extracted proteoglycans were determined with fluorophore-assisted carbohydrate electrophoresis. RESULTS: Loss of proteoglycans and accumulation of tissue water was evident in groups II and III, and progressive OA increased heterogeneity of aggrecan population in groups II and III. Importantly, the molar ratio of nonsulfated disaccharide was decreased in the osteoarthritic articular cartilage. CONCLUSION: The structure of chondroitin sulfate in degenerated bovine cartilage did not support the hypothesis that sulfate depletion is present in osteoarthritic joint.