Genome-wide copy number variation study and gene expression analysis identify ABI3BP as a susceptibility gene for Kashin–Beck disease

Kashin–Beck disease (KBD) is a chronic osteochondropathy. In this study, we conducted the first genome-wide copy number variation study (GCNVS) of KBD totally involving 2,743 Chinese Han adults. GCNVS was first performed using Affymetrix Human SNP6.0 Arrays. The identified copy number variations (CNVs) were then replicated in an independent Chinese Han sample containing 1,026 subjects. SNP genotyping, CNV identification and quality control were implemented by Birdsuite. STRUCTURE and EIGENSTRAT were applied for controlling potential population stratification in the GCNVS. Association analysis was conducted using PLINK. Microarray and qRT-PCR were also conducted to compare the expression levels of the genes overlapping with identified CNVs between KBD patients and healthy controls. GCNVS found that CNV452 (P value = 7.78 × 10^?5) overlapping with ABI3BP gene was significantly associated with KBD. Replication association study observed that rs9850273 (P value = 0.008) and rs7613610 (P value = 0.021) in ABI3BP gene were significantly associated with KBD. Gene expression analysis also found that ABI3BP was up-regulated in KBD patients compared to healthy controls. Our results suggest that ABI3BP was a novel susceptibility gene for KBD.     

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.     

Trans-omics pathway analysis suggests that eQTLs contribute to chondrocyte apoptosis of Kashin–Beck disease through regulating apoptosis pathway expression

Kashin–Beck disease (KBD) is a serious osteoarthropathia, mainly characterized by excessive chondrocyte necrosis and apoptosis. The molecular signaling pathways underlying KBD excessive chondrocyte apoptosis remain unclear, leading to a lack of effective medical interventions now. To clarify whether expression quantitative trait loci (eQTLs) contribute to excessive chondrocyte apoptosis of Kashin–Beck disease through regulating the expression of apoptosis pathways. We conducted a genome-wide eQTLs based pathway association analysis of KBD using Affymetrix Human SNP Array 6.0 in 1717 Chinese Han subjects. PLINK software was used for genome-wide association study (GWAS) of KBD. A modified gene set enrichment algorithm was applied for pathway association analysis based on GWAS results. The KBD-associated pathways were compared with abnormally expressed pathways in KBD articular cartilage, identified by microarray study of KBD. We identified 4 eQTLs pathways, which were not only significantly associated with KBD, but also abnormally expressed in KBD articular cartilage, including REACTOME_INTRINSIC_PATHWAY_FOR_APOPTOSIS (P = 0.008), MAHAJAN _RESPONSE_TO_IL1A_UP (P = 0.010), KEGG_PEROXISOME (P = 0.005) and MARKS_HDAC_TARGETS_UP (P = 0.006). Our results suggest that eQTLs contributed to KBD excessive chondrocyte apoptosis through regulating the expression of apoptosis related pathways. This study provides novel insight into the genetic susceptibility and therapeutic rationale of KBD.     

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.     

Disordered glycometabolism involved in pathogenesis of Kashin–Beck disease,an endemic osteoarthritis in China

Kashin–Beck disease (KBD) is a chronic endemic osteoarthritis in China. Previous studies have suggested a role of metabolic dysfunction in causation of this disease. In this investigation, the metabolomics approach and cell experiments were used to discover the metabolic changes and their effects on KBD chondrocytes. Nuclear magnetic resonance (¹H NMR) spectroscopy was used to examine serum samples from both the KBD patients and normal controls. The pattern recognition multivariate analysis (OSC–PLS) and quantitative analysis (QMTLS iterator) revealed altered glycometabolism in KBD, with increased glucose and decreased lactate and citrate levels. IPA biological analysis showed the centric location of glucose in the metabolic network. Massive glycogen deposits in chondrocytes and increased uptake of glucose by chondrocytes further confirmed disordered glycometabolism in KBD. An in vitro study showed the effects of disordered glycometabolism in chondrocytes. When chondrocytes were treated with high glucose, expression of type II collagen and aggrecan were decreased, while TNF-α expression, the level of cellular reactive oxygen species and cell apoptosis rates all were increased. Therefore, our results demonstrated that disordered glycometabolism in patients with KBD was linked to the damage of chondrocytes. This may provide a new basis for understanding the pathogenesis of KBD.     

Preventive Effects of Supplemental Selenium and Selenium Plus Iodine on Bone and Cartilage Development in Rats Fed with Diet from Kashin–Beck Disease Endemic Area

The purpose of this study was to investigate the effects of supplemental selenium and selenium plus iodine on bone and growth plate cartilage histology and serum biochemistic parameters in rats. Ninety-six Wistar rats were randomly divided into the following four groups: group A, the rats fed with normal diet; group B, fed with diet from Kashin–Beck disease (KBD) endemic area; group C, fed with diet from KBD endemic area supplemented with selenium; and group D, fed with diet from KBD endemic area supplemented with selenium and iodine. After 4, 8, and 12 weeks, bone and cartilage samples were collected from the rats and were examined for morphological changes in the tibial growth zone and for changes in the plate cartilage and metaphysic. Compared to the rats fed with diet from the KBD endemic area, the rats fed with the supplemental selenium or selenium plus iodine exhibited diminished necrosis of the chondrocytes in the growth plate. In the groups of rats receiving supplemental selenium and selenium plus iodine, the bone volume/tissue volume ratio (BV/TV), the trabecular thickness (Tb.Th), and the trabecular number were increased, while the trabecular separation was decreased. In the 12th week of the experiment, BV/TV and Tb.Th were significantly increased in the selenium plus iodine group compared to the selenium group. It is concluded that feeding the diet from the KBD endemic area caused necrosis of chondrocytes and dysfunctions of bone development similar to the pathological changes that are seen in KBD. Selenium and iodine protected chondrocytes in growth plate and promoted the formation of trabecular bone. The effects of selenium plus iodine on bone formation were more obvious than those of selenium alone     

Serious Selenium Deficiency in the Serum of Patients with Kashin–Beck Disease and the Effect of Nano-Selenium on Their Chondrocytes

Biological Trace Element Research - To investigate selenium (Se) concentrations in serum of patients with rheumatoid arthritis (RA), osteoarthritis (OA), and Kashin–Beck disease (KBD),...     

Whole-Exome Sequencing for the Identification of Susceptibility Genes of Kashin–Beck Disease

Objective

To identify and investigate the susceptibility genes of Kashin–Beck disease (KBD) in Chinese population.

Methods

Whole-exome capturing and sequencing technology was used for the detection of genetic variations in 19 individuals from six families with high incidence of KBD. A total of 44 polymorphisms from 41 genes were genotyped from a total of 144 cases and 144 controls by using MassARRAY under the standard protocol from Sequenom. Association was applied on the data by using PLINK1.07.

Results

In the sequencing stage, each sample showed approximately 70-fold coverage, thus covering more than 99% of the target regions. Among the single nucleotide polymorphisms (SNPs) used in the transmission disequilibrium test, 108 had a p-value of <0.01, whereas 1056 had a p-value of <0.05. Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway analysis indicates that these SNPs focus on three major pathways: regulation of actin cytoskeleton, focal adhesion, and metabolic pathways. In the validation stage, single locus effects revealed that two of these polymorphisms (rs7745040 and rs9275295) in the human leukocyte antigen (HLA)-DRB1 gene and one polymorphism (rs9473132) in CD2-associated protein (CD2AP) gene have a significant statistical association with KBD.

Conclusions

HLA-DRB1 and CD2AP gene were identified to be among the susceptibility genes of KBD, thus supporting the role of the autoimmune response in KBD and the possibility of shared etiology between osteoarthritis, rheumatoid arthritis, and KBD.     

Effects of lead and lead–melatonin exposure on protein and gene expression of metal transporters,proteins and the copper/zinc ratio in rats

Human lead (Pb) exposure induces many adverse health effects, including some related to lead accumulation in organs. Although lead bio-distribution in the body has been described, the molecular mechanism underlying distribution and excretion is not well understood. The transport of essential and toxic metals is principally mediated by proteins. How lead affects the expression of metal transporter proteins in the principal metal excretory organs, i.e., the liver and kidney, is unknown. Considering that co-administration of melatonin and lead reduces the toxic effects of lead and lead levels in the blood in vivo, we examined how lead and co-administration of lead and melatonin affect the gene and protein expression of metal transporter proteins (ZIP8, ZIP14, CTR1 and DMT1) in these organs. Rats were exposed intraperitoneally to lead or lead-melatonin. Our results show that Pb exposure induces changes in the protein and gene expression of ZIP8, ZIP14 and CTR1. Alterations in the copper/zinc ratio found in the blood, liver and kidney were likely related to these changes. With DMT1 expression (gene and protein), a positive correlation was found with lead levels in the kidney. Co-administration of melatonin and lead reduced lead-induced DMT1 expression through an unknown mechanism. This effect of melatonin relates to reduced lead levels in the blood and kidney. The metal transport protein function and our results suggest that DMT1 likely contributes to lead accumulation in organs. These data further elucidate the effects of lead on Cu and Zn and the molecular mechanism underlying lead bio-distribution in animals.     

Effects of Dietary Factors on Selenium Levels of Children to Prevent Kashin–Beck Disease During a High-Prevalence Period in an Endemic Area: a Cohort Study

Selenium (Se) supplements have been used to control Kashin–Beck disease (KBD) for decades, but the effect of diet without Se supplements is unclear because the prevalence of KBD has decreased. This matched cohort study was undertaken to determine dietary factors affecting selenium nutrition status of children living in KBD areas and the effects of Se supplements in preventing KBD. A total of 593 children aged 5–12 years were randomly selected during the high prevalence period of KBD from 1992 to 1995. Children in one village received Se supplemented (Se+) salt and were matched with three children in 16 other villages who did not receive Se supplemented (Se?) salt. A questionnaire and determinations of occipital hair Se to reflect body Se status were obtained at baseline (April 1992), at 6 months (October 1992), and yearly each April through 1995. Hair Se content in the Se+ group was significantly higher than in the Se? group (P?<?0.001) at all time-points and was significantly related to the incidence of suspected KBD symptoms (P?=?0.018). Four dietary factors significantly affected hair Se contents. Se levels were increased by consumption of Se+ salt (P?<?0.001) and eating meat/egg often (P?=?0.019) or occasionally (P?=?0.001). Se levels were decreased by consumption of grain mildewed at harvest or in storage (P?<?0.001 for each) and drinking ditch, river, or cellar water (P?<?0.001; P?=?0.002; P?<?0.001, respectively). These results show that Se+ salt had a significant effect in maintaining the Se nutrition status of children in this cohort study but that dietary factors in those without Se supplements contributed as well.     

Effects of growth temperature and nitrogen nutrition on expression of C3–C4 intermediate traits in Chenopodium album

Proto-Kranz plants represent an initial phase in the evolution from C₃ to C₃–C₄ intermediate to C₄ plants. The ecological and adaptive aspects of C₃–C₄ plants would provide an important clue to understand the evolution of C₃–C₄ plants. We investigated whether growth temperature and nitrogen (N) nutrition influence the expression of C₃–C₄ traits in Chenopodium album (proto-Kranz) in comparison with Chenopodium quinoa (C₃). Plants were grown during 5 weeks at 20 or 30 °C under standard or low N supply levels (referred to as 20SN, 20LN, 30SN, and 30LN). Net photosynthetic rate and leaf N content were higher in 20SN and 30SN plants than in 20LN and 30LN plants of C. album but did not differ among growth conditions in C. quinoa. The CO₂ compensation point (Γ) of C. album was lowest in 30LN plants (36 µmol mol^–1), highest in 20SN plants (51 µmol mol^–1), and intermediate in 20LN and 30SN plants, whereas Γ of C. quinoa did not differ among the growth conditions (51–52 µmol mol^–1). The anatomical structure of leaves was not considerably affected by growth conditions in either species. However, ultrastructural observations in C. album showed that the number of mitochondria per mesophyll or bundle sheath (BS) cell was lower in 20LN and 30LN plants than in 20SN and 30SN plants. Immunohistochemical observations revealed that lower accumulation level of P-protein of glycine decarboxylase (GDC-P) in mesophyll mitochondria than in BS mitochondria is the major factor causing the decrease in Γ values in C. album plants grown under low N supply and high temperature. These results suggest that high growth temperature and low N supply lead to the expression of C₃–C₄ traits (the reduction of Γ) in the proto-Kranz plants of C. album through the regulation of GDC-P expression.

     

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.     

Effects of myeloperoxidase −463 G/A gene polymorphism and plasma levels on coronary artery disease

Myeloperoxidase is a lysosomal enzyme of polymorphonuclear leucocytes that contributes to inflamatory responses. In previous studies it was shown that MPO was synthesized in atherosclerotic lesions responsible of lipoprotein oxidations. We aimed to determine the MPO −463 G/A gene polymorphism distribution in Turkish population and evaluate the effects of it on myeloperoxidase levels. There were 100 myocardial infarct patients and 100 healthy control subjects in our study. MPO polymorphism was studied by using PCR-RFLP technique and MPO levels were measured by ELISA. It was shown that MPO levels were increasing in patients after myocardial infarct event but there were no effect of MPO −463 G/A polymorphism on MPO levels. It was also found that serum total cholesterol and LDL-cholesterol levels and smoking was contributing factors in increments of MPO enzymes. We observed that MPO levels were increased in CAD but there were no effect of MPO −463 G/A polymorphism on MPO levels.     

Carrier and prenatal diagnosis of Lesch–Nyhan disease due to a defect in HPRT gene expression regulation

Lesch–Nyhan disease (LND) is caused by lack of hypoxanthine–guanine phosphoribosyltransferase (HPRT) activity. Mutations in HPRT1 gene show variability in type and location within the gene, and in certain patients the HPRT coding sequence is normal and the molecular defect cannot be found. These patients presented a decreased HPRT1 expression of unknown cause. This is the first report of a carrier and prenatal diagnosis of LND due to a defect in HPRT gene expression regulation.     

Polymorphisms in the TNF-α and IL-10 gene promoters and risk of psoriasis and correlation with disease severity

Several cytokines were assumed to play an essential role in the induction and the pathogenesis of psoriasis. The aim of this work was to investigate the role of TNF-α-308 and IL-10-1082 polymorphisms and their serum levels in the pathogenesis of psoriasis and determine their relation to disease severity. 110 Psoriasis patients and 120 healthy volunteers were genotyped for TNF-α-308 and IL-10-1082 polymorphism by polymerase chain reaction. Serum level of TNF-α and IL-10 were measured by ELISA. Our study demonstrated an association of IL-10-1082 polymorphism and psoriasis and between TNF α-308 polymorphism and psoriasis disease and severity. Serum TNF α increased in patients, while serum IL-10 decreased in patients with significant correlation between serum TNF-α and psoriasis severity. These results indicated that TNF-α-308 and IL-10-1082 polymorphisms imparted significant risk towards the development of psoriasis.