Analysis of N-glycosylation protein of Kashin-Beck disease chondrocytes derived from induced pluripotent stem cells based on label-free strategies with LC-MS/MS.

We aimed to compare N-glycosylation proteins in Kashin-Beck disease (KBD) chondrocytes and normal chondrocytes derived from induced pluripotent stem cells (iPSCs). KBD and normal iPSCs were reprogrammed from human KBD and normal dermal fibroblasts, respectively. Subsequently, chondrocytes were differentiated from KBD and normal iPSCs separately. Immunofluorescence was utilized to assay the protein markers of iPSCs and chondrocytes. Differential N-glycosylation proteins were screened using label-free strategies with LC-MS/MS. Bioinformatics analyses were utilized to interpret the functions of differential N-glycosylation proteins. Immunofluorescence staining revealed that both KBD-iPSCs and normal-iPSCs strongly expressed pluripotency markers OCT4 and NANOG. Meanwhile, chondrocyte markers collagen II and SOX9 are presented in KBD-iPSC-chondrocytes and normal-iPSC-chondrocytes. We obtained 87 differential N-glycosylation sites which corresponded to 68 differential proteins, which were constructed into 1 cluster. We obtained collagen type I trimer and 9 other biological processes; polysaccharide binding and 9 other molecular functions; regulation of transcription by RNA polymerase II and 9 other cellular components from GO; the Pl3K-Akt signaling pathway and 9 other KEGG pathways; peroxisome and 7 other subcellular locations; and integrin alpha chain, C-terminal cytoplasmic region, conserved site and 9 other classifications of domain annotations, and 2 networks. FGFR3 and LRP1 are expressed at higher levels in KBD-iPSC-chondrocytes, while the expressions of COL2A1, TIMP1, UNC5B, NOG, LEPR, and ITGA1 were down-regulated in KBD-iPSC-chondrocytes. The differential expressions of these N-glycosylation proteins may lead to the abnormal function of KBD chondrocytes.

Hydrochemical characteristics of surface waters and their relationships to the Kashin-Beck Disease in Longzi County, Tibet.

Although previous studies have been reported between the Kashin-Beck Disease (KBD) epidemic and the hydrochemical characteristics of surface waters, the etiology of the disease remains unclear. In the present study, we comprehensively investigated the relationship between the KBD and the hydrochemical characteristics of surface waters in Longzi County. Results show that, the pH (mean = 7.27 ± 0.30), total hardness (TH, mean = 57.08 ± 45.74 mg L-1), total dissolved solids (TDS, mean = 67.56 ± 44.00 mg L-1) and oxidation-reduction potential (ORP, mean = 84.11 ± 23.55 mV) of surface waters in KBD endemic areas are lower than those in the non-KBD endemic areas (means of pH = 7.49 ± 0.30; TH = 262.06 ± 123.29 mg L-1; TDS = 253.25 ± 100.39 mg L-1; ORP = 215.90 ± 55.99 mV). These results suggest that long-term consumption of low TDS, essential trace elements (e.g., nickel, cobalt, iron, selenium, zinc, molybdenum, and iodine) deficient, and potential toxic elements (e.g., arsenic) enriched waters by humans likely causes the KBD. Environmental factors such as the geology and geomorphology may produce biogeochemical imbalance, geomorphic, vegetation types and local climatic conditions may have significant impact on food fungi toxin poisoning and water organic compound poisoning, and these also impact the KBD occurrence.

Observation and Analysis of the Postoperative Analgesic Effect of Subanaesthetic Dose of Ketamine in Kashin-Beck Disease Patients after Total Knee Arthroplasty.

With the transformation of modern medical models, the medical needs of patients have changed from treatment to safe, comfortable, and painless treatment. Therefore, it is clinically important to find an ideal analgesia model to reduce the pain after total knee arthroplasty and minimize the impact of surgical trauma on the body pressure. This article aims to study the effects of lower limb nerve block combined with local infiltration analgesia of the joint cavity on the hemodynamics and postoperative analgesia effects of knee joint replacement in elderly patients by comparing the effects of the subanaesthetic dose of ketamine on the hemodynamics and postoperative analgesia effect of knee joint replacement in elderly patients' intraoperative analgesia program. This article proposes that 90 patients requiring unilateral total knee replacement were randomly divided into 3 groups, with 30 patients in each group, age 65-85 years, average age 75 years, ASA I ∼ II grade, and body mass index 13.89 ∼ 37.26. Use a multifunctional monitor to monitor the patient's continuous blood pressure (SBP/DBP) and mean arterial pressure (MAP), heart rate (HR), electrocardiogram (ECG), intraoperative pulse oxygen saturation (SpO2), and end-tidal carbon dioxide (PETCO2). The following are monitored: record the heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure before induction of anesthesia (T0), before the upper tourniquet (T1), and after the upper tourniquet (T2), before tourniquet withdrawal (T3), and after tourniquet withdrawal (T4), mean arterial pressure (MAP). The three groups of patients had different degrees of itching, vomiting, nausea, and other adverse reactions. The experimental results in this article show that, in elderly patients with epidural anesthesia, the use of propofol and dexmedetomidine to maintain the patient's BIS value between 60 and 70 can meet the depth of sedation required for surgery without important surgical operation knowledge.

Reduction of Smad2 caused by oxidative stress leads to necrotic death of hypertrophic chondrocytes associated with an endemic osteoarthritis.

OBJECTIVE: The occurrence and development of an endemic OA, Kashin-Beck disease (KBD), is closely related to oxidative stress induced by free radicals. The aim of the study was to find the key signalling molecules or pathogenic factors as a potential treatment strategy for KBD. METHODS: Real-time PCR and western blotting were performed to detect the mRNA and protein expression levels in cells and tissues. Immunohistochemical staining was assayed in rat models and human samples obtained from children. The type of cell death was identified by annexin V and propidium iodide staining with flow cytometry. RESULTS: Oxidative stress decreased levels of Smad2 and Smad3 in hypertrophic chondrocytes both in vitro and in vivo. In the cartilage of KBD patients, the expression of Smad2 and Smad3 proteins in the middle and deep zone was significantly decreased with an observed full deletion in the deep zone of some samples. Reduction of Smad2 protein induced necrotic death of hypertrophic chondrocytes, while reduction of Smad3 protein induced apoptosis. The reduction of Smad2 protein was not accompanied by Smad3 protein reduction in hypertrophic chondrocyte necrosis. Furthermore, the reduction of Smad2 also impaired the construction of tissue-engineered cartilage in vitro. CONCLUSION: These studies reveal that oxidative stress causes necrosis of hypertrophic chondrocytes by downregulating Smad2 protein, which increases the pathogenesis of KBD cartilage. The importance of Smad2 in the development of KBD provides a new potential target for the treatment of KBD.

Assessing the Health Loss from Kashin-Beck Disease and Its Relationship with Environmental Selenium in Qamdo District of Tibet, China.

Kashin-Beck Disease (KBD) is one of major endemic diseases in China. In this study, we estimated the health loss from KBD in Qamdo district of Tibet using the years lived with disability (YLD) metric and investigated the influence of environmental selenium (Se) on it by multiple regression model. The results showed that YLD rates produced a different ranking of health loss of KBD from that produced by prevalence rates between Basu and Luolong County, with higher health loss from KBD (43.61 YLD/1000) but lower prevalence (17.86%) in Basu County. YLD rates in two counites were both highest for the 45-64 years age group. Compared with the prevalence rate, the YLD rate had a closer relation to environmental Se and was significantly negatively correlated with Se in both soil and highland barley. The multiple linear regression further revealed that Se contents in cultivated soil and highland barley were main influencing factors for the health loss of KBD, which could explain 90.5% of the variation in YLD rates. The information obtained highlights the significance of the YLD metric in exploring the environmental etiology of KBD and provides important information on which to base decisions on future prevention and control of endemic diseases.

Prevention and control strategies for children Kashin-Beck disease in China: A systematic review and meta-analysis.

BACKGROUND: To evaluate prevention and control strategies for children with Kashin-Beck disease (KBD) in China through a systematic review and meta-analysis. METHODS: We conducted literature searches of articles indexed in Web of Knowledge, PubMed, Springerlink, Elsevier, the Chinese National Knowledge Infrastructure, and Wanfang data until February 2019. Search terms included "Kashin-Beck disease" or "KBD," and "improvement of water" or "change of grain" or "salt-rich selenium" or "comprehensive measures." Eligible studies were prospective trials of interventions in endemic area. Data extraction was performed by 2 independent authors using predefined data fields that also included quality evaluation. RESULTS: We screened 1183 potentially relevant articles, and included 22 studies that reported 24 trials, with data from 3700 healthy children and 2961 children KBD. The pooled odds ratios (ORs) and confidence intervals (95% CIs) for primary prevention new incidence in healthy children following interventions to comprehensive measures, change of grain, salt-rich selenium, and improvements of water were 0.15 (0.02, 0.95), 0.15 (0.03, 0.70), 0.19 (0.09, 0.38), and 0.20 (0.09, 0.42), respectively. The OR (95% CI) for clinical improvement in children KBD following interventions to improvement of water, salt-rich selenium, comprehensive measures, and change of grain were 5.03 (3.21, 7.89), 4.39 (3.15, 6.11), 2.98 (1.61, 5.52), and 2.35 (1.59, 3.47), respectively. All interventions showed significant differences and were effective (P < .05). CONCLUSION: Comprehensive measures and change of grain were the most effective measures in preventing new case, whereas improvement of water and salt-rich selenium resulted in clinical improvements in children KBD.

Selenium Content and/or T-2 Toxin Contamination of Cereals, Soil, and Children's Hair in Some Areas of Heilongjiang and Gansu Provinces, China.

It has been strongly suggested that selenium deficiency and T-2 contamination in cereals are responsible for the development of Kashin-Beck disease (KBD). In order to assess these risk factors of KBD in the internal and external environments, our team undertook a two-stage survey in some areas of Heilongjiang and Gansu Provinces, China. The selenium content in children's hair (293), cereal (192), and soil (46) samples were determined using the 2, 3-diamino-naphthalene fluorometric assay technique. The T-2 toxin contamination level in the cereal samples (704) was assayed using an ELISA kit. There were no clinical KBD cases identified in this survey. The selenium statuses of the children in all the investigated regions during the first phase were at the medium selenium nutrition level. During the second phase, the selenium status of the children in Weiyuan County, Ning County, and Shangzhi City was at the medium selenium nutrition level, at the edge of selenium deficiency, and selenium deficient, respectively. Furthermore, the selenium contents in the cereal and soil samples were low. During the first phase, the average T-2 toxin contamination level in the family staple food samples for all the investigated regions was about 10 ng/g. However, the T-2 toxin contamination levels in eight homegrown corn samples were higher than 100 ng/g. During the second phase, all the average T-2 toxin contamination levels in the flour and corn samples from the three investigated regions were less than 10 ng/g. Risk factors that affect the prevalence of KBD still remain in the internal and external environments of some areas in Heilongjiang and Gansu Provinces.

Gene expression profiles and molecular mechanism of cultured human chondrocytes' exposure to T-2 toxin and deoxynivalenol.

T-2 toxin and deoxynivalenol (DON) are secondary metabolites produced by Fusarium fungi and are commonly found on food and feed. Although T-2 toxin and DON have been suggested as the etiology of Kashin-Beck disease (KBD), an endemic osteochondropathy, little is known about the mechanism when human chondrocytes are exposed to T-2 toxin and DON. The purpose of this study is to identify the gene expression differences and underlying molecular changes modulated by T-2 toxin and DON in vitro in human chondrocytes. After the experiments of cell viability, the gene expression profiles were analyzed in cells that were treated with 0.01 µg/ml T-2 toxin and 1.0 µg/ml DON for 72 h by Affymetrix Human Gene Chip. The array results showed that 882 and 2118 genes were differentially expressed for T-2 toxin and DON exposure, respectively. Enrichment analysis revealed that diverse cellular processes including DNA damage, cell cycle regulation and metabolism of extracellular matrix were affected when human chondrocytes were exposed to T-2 toxin and DON. These results demonstrate the gene expression differences and molecular mechanism of cultured human chondrocytes exposure to T-2 toxin and DON, and provide a new insight into future research in the etiology of KBD.

Increased Chondrocyte Apoptosis in Kashin-Beck Disease and Rats Induced by T-2 Toxin and Selenium Deficiency.

OBJECTIVE: To investigate chondrocyte apoptosis and the expression of biochemical markers associated with apoptosis in Kashin-Beck disease (KBD) and in an established T-2 toxin- and selenium (Se) deficiency-induced rat model. METHODS: Cartilages were collected from the hand phalanges of five patients with KBD and five healthy children. Sprague-Dawley rats were administered a selenium-deficient diet for 4 weeks prior to T-2 toxin exposure. The apoptotic chondrocytes were observed by terminal deoxynucleotidyl transferase dUTP nick end labeling staining. Caspase-3, p53, Bcl-2, and Bax proteins in the cartilages were visualized by immunohistochemistry, their protein levels were determined by Western blotting, and mRNA levels were determined by real-time reverse transcription polymerase chain reaction. RESULTS: Increased chondrocyte apoptosis was observed in the cartilages of children with KBD. Increased apoptotic and caspase-3-stained cells were observed in the cartilages of rats fed with normal and Se-deficient diets plus T-2 toxin exposure compared to those in rats fed with normal and Se-deficient diets. Caspase-3, p53, and Bax proteins and mRNA levels were higher, whereas Bcl-2 levels were lower in rats fed with normal or Se-deficiency diets supplemented with T-2 toxin than the corresponding levels in rats fed with normal diet. CONCLUSION: T-2 toxin under a selenium-deficient nutritional status induces chondrocyte death, which emphasizes the role of chondrocyte apoptosis in cartilage damage and progression of KBD.

Zinc: the Other Suspected Environmental Factor in Kashin-Beck Disease in Addition to Selenium.

Kashin-Beck disease (KBD) is an endemic chronic osteochondral disease characterized by high prevalence, disability, and morbidity and is distributed from the northeast to the southwest in China, in some regions of Eastern Siberia in Russia, and in North Korea. Although the selenium deficiency etiological hypothesis for KBD has been proposed by scientists for decades, the idea that selenium deficiency is one of the most important environmental factors but not the primary and sole pathogenic factor for KBD has been widely accepted. Zn2+, which is closely involved in the synthesis of enzymes, nucleic acids, and proteins, is an essential microelement in vivo. A conundrum still exists in research on the relationship between Zn2+ and KBD due to inconsistent results, but it has been confirmed that Zn2+ can help repair metaphyseal lesions in patients with KBD, indicating that Zn2+ might play a key role in the pathogenesis of KBD, although the mechanism is unknown. The zinc-ZIP8-MTF1 axis in chondrocytes forms a catabolic cascade that promotes upregulation of the crucial effector matrix-degrading enzymes MMP3, MMP13, and ADAMTS5, thereby leading to osteoarthritis (OA) cartilage destruction. Zinc finger protein-related genes, the ZNT family, and the ZIP family of Zn2+ transporter genes have been found to be differentially expressed in KBD by high-throughput screening. Therefore, Zn2+ could play a key role in the pathogenesis of KBD.

Identified molecular mechanism of interaction between environmental risk factors and differential expression genes in cartilage of Kashin-Beck disease.

As environmental risk factors (ERFs) play an important role in the pathogenesis of Kashin-Beck disease (KBD), it is important to identify the interaction between ERFs and differentially expression genes (DEGs) in KBD. The environmental response genes (ERGs) were analyzed in cartilage of KBD in comparison to normal controls.We searched 5 English and 3 Chinese databases from inception to September 2015, to identify case-control studies that examined ERFs for KBD using integrative meta-analysis and systematic review. Total RNA was isolated from articular cartilage of KBD patients and healthy controls. Human whole genome microarray chip (Agilent) was used to analyze the amplified, labeled, and hybridized total RNA, and the validated microarray data were partially verified using real-time quantitative polymerase chain reaction (qRT-PCR). The ERGs were derived from the Comparative Toxicogenomics Database. The identified ERGs were subjected to KEGG pathway enrichment, biological process (BP), and interaction network analyses using the Database for Annotation, Visualization and Integrated Discovery (DAVID) v6.7, and STRING.The trace elements (selenium and iodine), vitamin E, and polluted grains (T-2 toxin/HT-2 toxin, deoxynivalenol, and nivalenol) were identified as the ERFs for KBD using meta-analysis and review. We identified 21 upregulated ERGs and 7 downregulated ERGs in cartilage with KBD compared with healthy controls, which involved in apoptosis, metabolism, and growth and development. KEGG pathway enrichment analysis found that 2 significant pathways were involved with PI3K-Akt signaling pathway and P53 signaling pathway, and gene ontology function analysis found 3 BPs involved with apoptosis, death, and cell death in KBD cartilage.According to previous results and our own research, we suggest that the trace element selenium and vitamin E induce PI3K-Akt signaling pathway and the mycotoxins (T-2 toxin/HT-2 toxin and DON) induce P53 signaling pathway, contributing to the development of KBD, and chondrocyte apoptosis and cell death.

The potential biochemical markers of Kashin-Beck disease: a meta-analysis.

OBJECTIVE: The objective of this study is to explore the cytokines in serum, synovial fluid as potential biomarkers of Kashin-Beck disease (KBD) and to further understand the role of these cytokines in the pathogenesis of KBD. METHODS: A systematic electronic database search was performed from inception up to 15 March 2015. Meta-analysis was performed for cytokines more than one repetition in studies with available data. The effect size was summarized as standardized mean difference (SMD) with 95% confidence intervals (CIs) by a random effect model. RESULTS: A total of 18 articles were included. The pooled standardized mean differences showed the serum levels of tumor necrosis factor alpha (2.72, 95% CI: 1.8 5-3.59), interleukin-1 beta (1.21, 95% CI: 0.6 1-1.80), and nitric oxide (2.60, 95% CI: 1.5 2-3.68) were significantly higher in adult KBD patients compared with that in healthy controls. CONCLUSIONS: There was explicit evidence showing that the tumor necrosis factor alpha, interleukin-1 beta and nitric oxide were closely related to the presence of KBD, and these cytokines played a vital role in the pathogenesis of KBD.

Integrative Multivariate Logistic Regression Analysis of Risk Factors for Kashin-Beck disease.

To determine the current evidence on risk factors for Kashin-Beck disease (KBD) using an integrative meta-analysis. We searched five English and three Chinese databases from inception to September 2015, to identify case-control studies that examined risk factors for KBD using multivariate logistic analysis. DerSimonian and Laird effective models are applied in processing data using pooled odds ratios (ORs) and 95 % confidence intervals (CI). Seven studies were identified with 3087 cases and 6402 controls. The main risk factors found to be significantly associated with the onset of KBD were age (OR 1.19, 95 % CI 1.10-1.28), parents prevalence (OR 5.16, 2.51-7.80), family hygiene (OR 1.68, 1.42-1.93), food source (OR 3.29, 2.38-4.19), wheat (OR 1.12, 1.08-1.16), wheat germ necrosis rate (OR 6.03, 1.87-12.92), total volatile basic nitrogen (OR 6.85, 1.01-28.67), low selenium in hair (OR 2.29, 1.08-3.50) were found to be significant risks factors. The pooled ORs (95 % CI) of protein intake and rice were 0.79 (0.66-0.93) and 0.90 (0.86-0.95), respectively, indicating that the two factors may be protective for KBD. We found that the combination of low protein intake, polluted grain, and selenium deficiency may contribute to be onset of KBD together.

The roles of selenium, insulin-like growth factor binding protein 2 and suppressor of cytokine signaling 3 in the pathogenesis of Kashin-Beck disease.

We aimed to verify the levels of IGFBP2 and SOCS3 in cartilage and chondrocytes of Kashin-Beck disease (KBD) patients and the effects of different selenium concentrations on the protein expression levels. Chondrocytes were cultured with sodium selenite in vitro. Immunohistochemistry and western blotting were used to verify the protein expressions. IGFBP2 and SOCS3 were up-regulated in KBD chondrocytes and decreased with increasing selenium concentrations. IGFBP2 expressed highest in the middle zone of KBD cartilage, SOCS3 expressed higher in the middle and deep zone. IGFBP2 and SOCS3 may be the biomarkers for KBD diagnosis and evaluating the effect of selenium supplement.

Is It the Appropriate Time to Stop Applying Selenium Enriched Salt in Kashin-Beck Disease Areas in China?

We aimed to identify significant factors of selenium (Se) nutrition of children in Kashin-Beck disease (KBD) endemic areas and non-KBD area in Shaanxi Province for providing evidence of whether it is the time to stop applying Se-enriched salt in KBD areas. A cross-sectional study contained 368 stratified randomly selected children aged 4-14 years was conducted with 24-h retrospective questionnaire based on a pre-investigation. Food and hair samples were collected and had Se contents determined with hydride generation atomic fluorescence spectrometry. Average hair Se content of 349.0 ± 60.2 ng/g in KBD-endemic counties was significantly lower than 374.1 ± 47.0 ng/g in non-KBD counties. It was significantly higher in the male children (365.2 ± 52.3 ng/g) than in the female (345.0 ± 62.2 ng/g, p = 0.002) and significantly higher in the 4.0-6.9 years group (375.2 ± 58.9 ng/g) than the 7.0-14.0 years group (347.0 ± 56.1 ng/g, p < 0.01). Gender, living area, Se intake without supplements, Se-enriched salt, oil source and protein intake were identified as significant factors of hair Se contents. Cereals, meat and milk were commonly included as significant food categories that mainly contributed to Se intake without supplement of the whole population. Balanced dietary structure without Se supplement could effectively enhance and maintain children's Se nutrition. It may be the time to stop applying Se-enriched salt in KBD areas in Shaanxi Province.

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.

Role of selenoprotein S (SEPS1) -105G>A polymorphisms and PI3K/Akt signaling pathway in Kashin-Beck disease.

OBJECTIVE: To investigate the relationship between SEPS1 polymorphism and phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway in Kashin-Beck disease (KBD) and further explore the pathogenesis of KBD. METHODS: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to detect SEPS1 -105G>A polymorphism in 232 cases and 331 controls. The protein expressions of PI3K/Akt signaling molecules in whole blood and chondrocytes were detected by Western blot. RESULTS: The frequencies of SEPS1 -105G>A genotype AA (21.1% vs 3.0%) and minor allele A (34.1% vs 16.0%) in KBD are significantly higher than those in controls (OR: 8.020, 95% confidence interval (95% CI) 6.341-10.290, P < 0.0001; OR: 2.470, 95% CI 2.001-4.463, P < 0.0001, respectively). SEPS1 AA genotype was an independent risk factor for KBD (adjusted OR: 9.345, 95% CI 4.254-20.529; P < 0.0001). The expression of Gßγ, PI3Kp110, pAkt and pGSK3ß in KBD group were higher than that in control group (all P < 0.05). Gßγ, pAkt and pGSK3ß protein expression of AA and GA increased than GG (all P < 0.05). Cell apoptosis was increasing and molecule expression of PI3K/Akt signaling pathway were up-regulated in the tert-Butyl hydroperoxide (tBHP)-injured group, the cell apoptosis and expression levels of PI3K/Akt in Na2SeO3 group were decreased. CONCLUSIONS: The SEPS1 -105G>A is associated with an increased risk of KBD and influences the expression of PI3K/Akt signaling pathway in KBD patients. Apoptosis induced by tBHP in chondrocyte might be mediated via up-regulation of PI3K/Akt, Na2SeO3 has an effect of anti-apoptosis by down-regulating of PI3K/Akt signaling pathway.

Serum levels of M-CSF, RANKL and OPG in rats fed with Kashin-Beck disease-affected diet.

OBJECTIVE: There were no studies on the macrophage colony-stimulating factor (M-CSF), receptor activator of NF-kappaB ligand (RANKL) and osteoprotegerin (OPG) in the pathogenesis of Kashin-Beck disease (KBD). The objective of the present study was to investigate the serum M-CSF, RANKL and OPG in rats fed with KBD-affected diet. METHODS: Ninety Wistar rats were divided into five groups. The rats received standard commercial feed with or without T-2 toxin additive, low protein feed with or without or T-2 toxin additive and the KBD-affected feed. The serum bioactivity of M-CSF, RANKL and OPG was tested by enzyme-linked immunosorbent assay. RESULTS: The serum levels of M-CSF in E group rats were higher than those in the other groups in the five groups (P < 0.01). The serum levels of RANKL and OPG in E group rats were highest in the five groups and have significant difference compared to the other groups (P < 0.05). CONCLUSIONS: The molecule of M-CSF, RANKL and OPG may be involved in the regulation of epiphyseal plate injury and repair in KBD, and its participation in the pathogenesis of KBD should be studied in the future.

Changes in the metabolism of chondroitin sulfate glycosaminoglycans in articular cartilage from patients with Kashin-Beck disease.

OBJECTIVES: To identify changes in the expression patterns of enzymes involved in chondroitin sulfate (CS) glycosaminoglycan (GAG) metabolism in articular cartilage proteoglycan (PG) isolated from adolescent patients with Kashin-Beck disease (KBD). METHODS: Samples of articular cartilage were divided into two groups: Control samples (from five normal children), and KBD samples (from five KBD children) aged 3-12 years old. The morphology and pathology of hand joint cartilage were examined by histochemical staining. The localization and expression patterns of enzymes involved in CS GAG metabolism (i.e., PAPS synthetase 2 (PAPSS2), PAPS transporter 1 (PAPST1), Carbohydrate (N-acetylgalactosamine 4-sulfate 6-O) sulfotransferases 15 (CHST15), Arylsulfatase B (ARSB) and N-acetylgalactosamine-6-sulfate sulfatase (GALNS)) were performed using immuno-histochemical analyses. Positive immunostaining in articular cartilage was semi-quantified. RESULTS: Reduced aggrecan staining was observed in KBD samples compared with the control samples. The percentages of positive staining for the anabolic enzymes PAPSS2, PAPST1 and CHST15 in the upper and middle zones of KBD samples were significantly lower than that found in the Controls. In contrast, the percentages of positive staining in KBD samples for the catabolic enzymes ARSB and GALNS were significantly higher than the control samples. However, the staining for all of these GAG metabolism enzymes were hardly observed in the deep zones of KBD cartilage, suggesting that significant cell death and necrosis had occurred in this region. CONCLUSIONS: Our results indicate that alterations of enzymes involved in articular cartilage CS GAG metabolism on PGs in the articular cartilage play an important role in the onset and pathogenesis of KBD in adolescent children.