The Long-term Efficacy of Total Knee Arthroplasty on End-stage Kashin-Beck Disease of the Knee in Highland Tibetan Areas Patients: A Retrospective Study with 10-Year Follow-up

OBJECTIVE

Despite the established success of total knee arthroplasty (TKA) with end-stage osteoarthritis, there is a notable scarcity of research on its long-term outcomes in individuals suffering from end-stage Kashin-Beck disease (KBD). This retrospective study aimed to assess the long-term outcomes and effectiveness of clinical function, quality of life, and complications of TKA and end-stage KBD patients in Tibetan highland areas.

METHODS

The retrospective cohort included 43 KBD patients, comprising a total of 59 knees, who had undergone TKA at West China Hospital, Sichuan University between 2008 and 2021. Patients were subsequently followed up for a minimum of 3 years, and received rigorous radiological and clinical assessments at 3, 6, and 12 months post surgery, followed by annual examinations thereafter. The evaluation included various efficacy indices, including visual analogue scale (VAS) scores, hospital for special surgery (HSS) scores, functional score for adult Tibetans with Kashin-Beck disease (FSAT-KBD), and radiographic findings. Comparison of indicators within the same group was conducted using one-way repeated-measures analysis of variance or paired sample t-tests, whereas between-group differences were compared using an independent t-test.

RESULTS

Throughout the average follow-up duration of 10.8 years, patients experienced a substantial reduction in knee pain and noteworthy functional improvement. The VAS scores decreased significantly from 77.47 ± 4.12 mm before surgery to 10.91 ± 1.97 mm after surgery, indicating considerable alleviation of knee pain. The HSS scores improved markedly, increasing from 44.26 ± 4.95 preoperatively to 91.26 ± 4.37, indicating enhanced joint function. Similarly, the FSAT-KBD exhibited positive progression, increasing from 25.90 ± 3.12 to 36.95 ± 3.54. Importantly, at the last follow-up, none of the patients presented with periprosthetic infection, prosthesis loosening, or periprosthetic fracture.

CONCLUSION

At long-term follow-up, compared with patients in the preoperative period, patients in Tibetan highland areas with KBD of the knee who underwent TKA benefited from a significant reduction in pain, improvement in joint function, and satisfactory improvement in quality of life.

Whole-Transcriptome Sequencing of Knee Joint Cartilage from Kashin-Beck Disease and Osteoarthritis Patients

The aim of this study was to provide a comprehensive understanding of similarities and differences in mRNAs, lncRNAs, and circRNAs within cartilage for Kashin-Beck disease (KBD) compared to osteoarthritis (OA). We conducted a comparison of the expression profiles of mRNAs, lncRNAs, and circRNAs via whole-transcriptome sequencing in eight KBD and ten OA individuals. To facilitate functional annotation-enriched analysis for differentially expressed (DE) genes, DE lncRNAs, and DE circRNAs, we employed bioinformatic analysis utilizing Gene Ontology (GO) and KEGG. Additionally, using quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), we validated the expression levels of four cartilage-related genes in chondrocytes. We identified a total of 43 DE mRNAs, 1451 DE lncRNAs, and 305 DE circRNAs in KBD cartilage tissue compared to OA (q value < 0.05; |log2FC| > 1). We also performed competing endogenous RNA network analysis, which identified a total of 65 lncRNA-mRNA interactions and 4714 miRNA-circRNA interactions. In particular, we observed that circRNA12218 had binding sites for three miRNAs targeting ACAN, while circRNA12487 had binding sites for seven miRNAs targeting COL2A1. Our results add a novel set of genes and non-coding RNAs that could potentially serve as candidate diagnostic biomarkers or therapeutic targets for KBD patients.

Involvement of Yes-Associated Protein 1 Activation in the Matrix Degradation of Human-Induced-Pluripotent-Stem-Cell-Derived Chondrocytes Induced by T-2 Toxin and Deoxynivalenol Alone and in Combination

T-2 toxin and deoxynivalenol (DON) are two prevalent mycotoxins that cause cartilage damage in Kashin-Beck disease (KBD). Cartilage extracellular matrix (ECM) degradation in chondrocytes is a significant pathological feature of KBD. It has been shown that the Hippo pathway is involved in cartilage ECM degradation. This study aimed to examine the effect of YAP, a major regulator of the Hippo pathway, on the ECM degradation in the hiPS-derived chondrocytes (hiPS-Ch) model of KBD. The hiPS-Ch injury models were established via treatment with T-2 toxin/DON alone or in combination. We found that T-2 toxin and DON inhibited the proliferation of hiPS-Ch in a dose-dependent manner; significantly increased the levels of YAP, SOX9, and MMP13; and decreased the levels of COL2A1 and ACAN (all p values < 0.05). Immunofluorescence revealed that YAP was primarily located in the nuclei of hiPS-Ch, and its expression level increased with toxin concentrations. The inhibition of YAP resulted in the dysregulated expression of chondrogenic markers (all p values < 0.05). These findings suggest that T-2 toxin and DON may inhibit the proliferation of, and induce the ECM degradation, of hiPS-Ch mediated by YAP, providing further insight into the cellular and molecular mechanisms contributing to cartilage damage caused by toxins.

Comparative Analysis of Gut Microbiota from Rats Induced by Se Deficiency and T-2 Toxin

The aim of this study was to analyze the differences in gut microbiota between selenium deficiency and T-2 toxin intervention rats. Knee joint and fecal samples of rats were collected. The pathological characteristics of knee cartilage were observed by safranin O/fast green staining. DNA was extracted from fecal samples for PCR amplification, and 16S rDNA sequencing was performed to compare the gut microbiota of rats. At the phylum level, Firmicutes (81.39% vs. 77.06%) and Bacteroidetes (11.11% vs. 14.85%) were dominant in the Se-deficient (SD) group and T-2 exposure (T-2) groups. At the genus level, the relative abundance of Ruminococcus_1 (12.62%) and Ruminococcaceae_UCG-005 (10.31%) in the SD group were higher. In the T-2 group, the relative abundance of Lactobacillus (11.71%) and Ruminococcaceae_UCG-005 (9.26%) were higher. At the species level, the high-quality bacteria in the SD group was Ruminococcus_1_unclassified, and Ruminococcaceae_UCG-005_unclassified in the T-2 group. Lactobacillus_sp__L_YJ and Lactobacillus_crispatus were the most significant biomarkers in the T-2 group. This study analyzed the different compositions of gut microbiota in rats induced by selenium deficiency and T-2 toxin, and revealed the changes in gut microbiota, so as to provide a certain basis for promoting the study of the pathogenesis of Kashin-Beck disease (KBD).

Untargeted Metabolomics Approach Correlated Enniatin B Mycotoxin Presence in Cereals with Kashin-Beck Disease Endemic Regions of China

Kashin-Beck disease (KBD) is a multifactorial endemic disease that only occurs in specific Asian areas. Mycotoxin contamination, especially from the Fusarium spp., has been considered as one of the environmental risk factors that could provoke chondrocyte and cartilage damage. This study aimed to investigate whether new mycotoxins could be identified in KBD-endemic regions as a potential KBD risk factor. This was investigated on 292 barley samples collected in Tibet during 2009-2016 and 19 wheat samples collected in Inner Mongolia in 2006, as control, from KBD-endemic and non-endemic areas. The LC-HRMS(/MS) data, obtained by a general mycotoxin extraction technic, were interpreted by both untargeted metabolomics and molecular networks, allowing us to identify a discriminating compound, enniatin B, a mycotoxin produced by some Fusarium spp. The presence of Fusarium spp. DNA was detected in KBD-endemic area barley samples. Further studies are required to investigate the role of this mycotoxin in KBD development in vivo.

The Role of Selenium-Mediated Notch/Hes1 Signaling Pathway in Kashin-Beck Disease Patients and Cartilage Injury Models

Kashin-Beck disease (KBD) is a nutrition-related osteoarthropathy, and selenium (Se) deficiency is an environmental risk factor for KBD. Notch/Hes1 signaling pathway plays a vital role in regulating cartilage, but its exact mechanisms in KBD remain unknown. The Se contents were determined using the hydride atomic fluorescence spectrometry assay technique, and the mRNA levels were detected via quantitative real-time PCR. The chondrocyte injury models were established by Se deficiency and tert-butyl hydroperoxide (tBHP), respectively; apoptosis and necrosis rates were detected using Hoechst 33,342/PI and Annexin V-FITC/PI. The results showed that the Se levels in the flour of KBD areas were lower than that of the non-KBD areas, and the Se levels in the plasma of KBD patients were lower than that of the controls. The expressions of Notch1, Jagged1, and Hes1 were higher in the whole blood of KBD patients than those of the controls, and Notch1 was negatively correlated with the expression of BCL2, while was positively correlated with BAX. In injury, chondrocytes induced by low Se and tBHP, the expression of Notch1, Jagged1, and Hes1 increased, apoptosis and necrosis rates increased in Se deficiency and tBHP groups, while Se supplementation reversed it. Decreased plasma Se in KBD patients may be related to low dietary Se. Se deficiency might be involved in the pathological process of KBD by activating the Notch/Hes1 signaling pathway to induce excessive apoptosis of chondrocytes, the activation of Notch/Hes1 promotes oxidative injury, and Se supplementation could reverse it. The importance of Notch/Hes1 signaling pathway in KBD development will provide a new potential target for KBD.

ATAC-seq reveals the roles of chromatin accessibility in the chondrocytes of Kashin-Beck disease compared with primary osteoarthritis

Objective: This study aimed to investigate the roles of accessible chromatin in understanding the different pathogeneses between Kashin-Beck disease (KBD) and primary osteoarthritis (OA). Methods: Articular cartilages of KBD and OA patients were collected, and after tissue digestion, primary chondrocytes were cultured in vitro. Assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) was performed to compare the accessible chromatin differences of chondrocytes between KBD and OA groups. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were executed for the promoter genes. Then, the IntAct online database was used to generate networks of significant genes. Finally, we overlapped the analysis of differentially accessible region (DAR)-associated genes and differentially expressed genes (DEGs) obtained from whole-genomic microarray. Results: We obtained 2,751 total DARs, which contained 1,985 loss and 856 gain DARs and belonged to 11 location distributions. We obtained 218 motifs associated with loss DARs, 71 motifs associated with gain DARs, 30 motif enrichments of loss DARs, and 30 motif enrichments of gain DARs. In total, 1,749 genes are associated with loss DARs, and 826 genes are associated with gain DARs. Among them, 210 promoter genes are associated with loss DARs, and 112 promoter genes are associated with gain DARs. We obtained 15 terms of GO enrichment and 5 terms of KEGG pathway enrichment from loss DAR promoter genes, and 15 terms of GO enrichment and 3 terms of KEGG pathway enrichment from gain DAR promoter genes. We obtained CAPN6 and other 2 overlap genes from loss DARs-vs-down DEGs, AMOTL1 from gain DARs-vs-down DEGs, EBF3 and other 12 overlap genes from loss DARs-vs-up DEGs, and ADARB1 and other 10 overlap genes from 101 gain DARs-vs-up DEGs. These overlap genes were built into 4 gene interaction networks. Conclusion: FGF7, GPD1L, NFIB, RUNX2, and VCAM1 were the overlapped genes from the DAR-associated genes and DEGs. These genes were associated with the abnormal chondrocyte function, which may play crucial roles in different processes between KBD and OA in the way of accessible chromatin.

Health-related quality of life in patients with Kashin-Beck disease is lower than in those with osteoarthritis: a cross-sectional study

BACKGROUND

Kashin-Beck disease (KBD) is an endemic deformable bone and joint disease, which affects the quality of life (QOL) of patients. We conducted a cross-sectional study of the QOL of KBD patients by a new KBD quality of life (KBDQOL) questionnaire.

METHODS

A total of 252 KBD patients and 248 OA patients came from Northwest China, and 260 healthy people living in the same area as KBD and osteoarthritis (OA) patients served as the controls. KBDQOL questionnaire was used to evaluate the QOL of all objects.

RESULTS

The average scores for physical functions, activity limitations, support of society, mental health and general health were significantly lower in KBD patients than that in OA patients and healthy people except for economics. Monofactor analysis showed that age, height, weight status, education level and grade of KBD had a significant effect on KBDQOL score. Multivariate analysis showed that grade of KBD was the influencing factor of physical function score; gender, age, height, grade of KBD and duration of symptoms were the influencing factors of activity restriction score; age and grade of KBD were factors affecting the general health score.

CONCLUSION

The QOL of KBD patients was significantly lower than that of OA patients and healthy people. The KBDQOL questionnaire may be a promising tool for assessing the QOL of KBD patients.

A study on atypical Kashin-Beck disease: an endemic ankle arthritis

BACKGROUND

To study the epidemiological characteristics of atypical Kashin-Beck disease cases without characteristic hand lesions such as interphalangeal joint enlargement and brachydactyly and the characteristics of ankle joint lesions.

METHODS

We investigated Kashin-Beck in the endemic villages in Heilongjiang Province. The patients were judged according to the "Diagnosis of Kashin-Beck Disease" (WS/T 207-2010). The severity of foot lesions was judged based on the changes of X-ray images. Residents of non-Kashin-Beck disease area were selected as normal controls in Jilin Province.

RESULTS

A total of 119 residents over 40 years old were surveyed in a natural village in the non-endemic area. A total of 1190 residents over 40 years old were surveyed in 38 endemic areas of Kashin-Beck disease. A total of 710 patients with Kashin-Beck disease were detected, including 245 patients with grade I, 175 patients with grade II, 25 patients with grade III, and 265 atypical patients. Among all investigated patients, 92.0% (653/710) had ankle joint changes, and it was 80.0% (196/245) in grade I patients and 95.4% (167/175) in grade II. Varying degrees of ankle joint changes were found in both grade III and atypical patients. The grade of Kashin-Beck disease was correlated with the degree of ankle joint change (P < 0.001), and the correlation coefficient r_s = 0.376. Atypical Kashin-Beck disease patients in mild and severe endemic area of Kashin-Beck disease were younger than those with typical Kashin-Beck disease.

CONCLUSIONS

We found a correlation between the degree of ankle joint change and the grade of Kashin-Beck disease. The higher the grade of Kashin-Beck disease, the more serious the change of the ankle joint.

Prevalence and radiographic features of atlantoaxial dislocation in adult patients with Kashin-Beck disease

PURPOSE

Kashin-Beck disease (KBD) is an endemic osteoarthropathy affecting the epiphyseal growth plate of multiple joints in young and adolescent patients. Previous studies have focused on the visible deformed extremities instead of the spinal radiological features, especially the atlantoaxial joint. The aim of this study was to determine the prevalence and radiographic features of atlantoaxial dislocation (AAD) in adult patients with KBD.

METHODS

This study was conducted on KBD patients in three typical endemic counties between October 2017 and November 2019. The patients were evaluated by collecting basic information, clinical signs and symptoms. They underwent dynamic cervical radiography, by which AAD was diagnosed. For those patients with confirmed or suspected AAD, computed tomography (CT) imaging was performed to observe the odontoid morphology and degenerative changes in the lateral atlantoaxial joints. Radiographic evaluations were reviewed to determine the prevalence and features of AAD.

RESULTS

A total of 39 (14.6%) of 267 KBD patients were diagnosed with AAD. Compared with the non-AAD patients, the detection rate of AAD was associated with a longer disease duration and stage and was not associated with age, sex or BMI. Thirty-two patients had symptoms at the neck or neurological manifestations, while seven had no symptoms. There were three types of morphologies of the odontoid process in AAD patients: separating in 19 cases, hypoplastic in 15 cases and intact in five cases. Anterior dislocation was noted in 29 cases, and posterior dislocation was noted in ten cases. Thirty-four cases were reducible, and five were irreducible. The lateral atlantoaxial joints had different severities of degenerative changes in 17 cases.

CONCLUSIONS

This study revealed that the prevalence of AAD was 14.6% in adult KBD patients. The radiographic features of AAD include manifestations of odontoid dysplasia and chronic degenerative changes in atlantoaxial joints. KBD patients with severe stages and longer disease duration were more vulnerable to the occurrence of AAD. We postulate that this atlantoaxial anomaly might originate from chondronecrosis of the epiphyseal growth plate of the odontoid process in young and adolescent individuals. This study may provide a clinical reference to help clinicians screen, prevent and treat AAD in adult patients with KBD.

Detection of selenoprotein transcriptome in chondrocytes of patients with Kashin-Beck disease

Background: Kashin-Beck disease (KBD) is a deformed osteochondral disease with a chronic progression that is restrictively distributed in eastern Siberia, North Korea, and some areas of China, and selenium deficiency has been identified as an important factor in the pathogenesis of this disease in recent years. Objective: The aim of this study is to investigate the selenoprotein transcriptome in chondrocytes and define the contribution of selenoprotein to KBD pathogenesis. Methods: Three cartilage samples were collected from the lateral tibial plateau of adult KBD patients and normal controls paired by age and sex for real-time quantitative polymerase chain reaction (RT-qPCR) to detect the mRNA expression of 25 selenoprotein genes in chondrocytes. Six other samples were collected from adult KBD patients and normal controls. In addition, immunohistochemistry was used on four adolescent KBD samples and seven normal controls (IHC) to determine the expression of proteins screened by RT-qPCR results that had different gene levels. Results: Increased mRNA expression of GPX1 and GPX3 was observed in chondrocytes, and stronger positive staining was displayed in the cartilage from both adult and adolescent patients. The mRNA levels of DIO1, DIO2, and DIO3 were increased in KBD chondrocytes; however, the percentage of positive staining decreased in the KBD cartilage of adults. Conclusion: The selenoprotein transcriptome, mainly the glutathione peroxidase (GPX) and deiodinase (DIO) families were altered in KBD and might play a vital role in the pathogenesis of KBD.

Identification of N-Glycoproteins of Knee Cartilage from Adult Osteoarthritis and Kashin-Beck Disease Based on Quantitative Glycoproteomics, Compared with Normal Control Cartilage

Glycoproteins are involved in the development of many diseases, while the type and content of N-glycoproteins in the cartilage of osteoarthritis (OA) and Kashin-Beck disease (KBD) are still unclear. This research aims to identify N-glycoproteins in knee cartilage patients with OA and KBD compared with normal control (N) adults. The cartilage samples were collected from gender- and age-matched OA (n = 9), KBD (n = 9) patients, and N (n = 9) adults. Glycoproteomics and label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS) obtained N-glycoproteins of KBD and OA. A total of 594 N-glycoproteins and 1146 N-glycosylation peptides were identified. The identified data were further compared and analyzed with Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Protein-Protein Interactions (PPI). Pairwise comparison of the glycoproteins detected in the three groups showed that integrin beta-1 (ITGB1), collagen alpha-1 (II) chain (COL2A1), collagen alpha-1 (VII) chain (COL7A1), carbohydrate sulfotransferase 3 (CHST-3), carbohydrate sulfotransferase 4 (CHST-4), thrombospondin 2 (THBS2), bone morphogenetic protein 8A (BMP8A), tenascin-C (TNC), lysosome-associated membrane protein (LAMP2), and beta-glucuronidase (GUSB) were significantly differentially expressed. GO results suggested N-glycoproteins mainly belonged to protein metabolic process, single-multicellular and multicellular organism process, cell adhesion, biological adhesion, and multicellular organism development. KEGG and PPI results revealed that key N-glycoproteins were closely related to pathways for OA and KBD, such as phagosome, ECM-receptor interaction, lysosome, focal adhesion, protein digestion, and absorption. These results reflected glycoprotein expression for OA and KBD in the process of ECM degradation, material transport, cell-cell or cell-ECM interaction, and information transduction. These key significantly differentially expressed N-glycoproteins and pathways lead to the degeneration and degradation of the cartilage of OA and KBD mainly by disrupting the synthesis and catabolism of basic components of ECM and chondrocytes and interfering with the transfer of material or information. The key N-glycoproteins or pathways in this research are potential targets for pathological mechanisms and therapies of OA and KBD.

Effectiveness of Selenium on Chondrocyte Glycoprotein Glycosylation Which Play Important Roles in the Pathogenesis of an Endemic Osteoarthritis, Kashin-Beck Disease

In this study, we aimed to explore the effectiveness of selenium on the chondrocyte glycoprotein glycosylation which plays important roles in the pathogenesis of Kashin-Beck disease (KBD). Cartilage samples were collected from KBD patients after total knee replacement surgery. Chondrocytes were cultured with sodium selenium. The group of chondrocytes which were cultured without adding sodium selenium was considered as control group. Lectin microarray was used to screen the differences in lectin levels between KBD and KBD with selenium groups. Stronger signals for Bandeiraea simplicifolia (BS-I), Hippeastrum hybrid lectin (HHL), Pisum sativum agglutinin (PSA), Psophocarpus tetragonolobus lectin I (PTL-I), Psophocarpus tetragonolobus lectin II (PTL-II), Sophora japonica agglutinin (SJA), Lotus tetragonolobus lectin (LTL), and Triticum vulgaris (WGA) were observed in the KBD group. Meanwhile, Aleuria aurantia lectin (AAL), Lens culinaris agglutinin (LCA), Lycopersicon esculentum (tomato) lectin (LEL), Peanut agglutinin (PNA), and Sambucus nigra lectin (SNA) signals were lower in the KBD group. Selenium may have the function of influence the expression levels of carbohydrate chains Galα1,3-Gal, high mannose, and GlcNAc.

Nurses' Working Experiences of Their Provision of Cross-Cultural Services to Tibetan Patients With Kashin-Beck Disease: A Qualitative Study

INTRODUCTION

Limited qualitative studies exist on nurses' experience in terms of communicating with and caring for patients with endemic diseases. The purpose of this study was to describe the working experiences of nurses caring for Tibetan patients with Kashin-Beck disease in China.

METHOD

A qualitative design was used in this study. Sixteen nurses who worked in the orthopedics department of a large tertiary general hospital in Wuhan, China, constituting a purposive sample, were interviewed face-to-face using semi-structured guided questions.

RESULTS

Three major themes and nine subthemes were identified. Major themes included the challenge in cross-cultural nursing, stress adjustment in cross-cultural nursing, and reshaping competencies in cross-cultural nursing.

DISCUSSION

This study revealed that nurses encountered multifaceted challenges when caring for Tibetan patients with Kashin-Beck disease. In a multiethnic society, communication and language skills, cultural competency and cultural sensitivity, and diverse training methods to improve cross-cultural knowledge could increase ethnic minority patient satisfaction with cross-cultural care.

Genetic Variants and Protein Alterations of Selenium- and T-2 Toxin-Responsive Genes Are Associated With Chondrocytic Damage in Endemic Osteoarthropathy

The mechanism of environmental factors in Kashin–Beck disease (KBD) remains unknown. We aimed to identify single nucleotide polymorphisms (SNPs) and protein alterations of selenium- and T-2 toxin–responsive genes to provide new evidence of chondrocytic damage in KBD. This study sampled the cubital venous blood of 258 subjects including 129 sex-matched KBD patients and 129 healthy controls for SNP detection. We applied an additive model, a dominant model, and a recessive model to identify significant SNPs. We then used the Comparative Toxicogenomics Database (CTD) to select selenium- and T-2 toxin–responsive genes with the candidate SNP loci. Finally, immunohistochemistry was applied to verify the protein expression of candidate genes in knee cartilage obtained from 15 subjects including 5 KBD, 5 osteoarthritis (OA), and 5 healthy controls. Forty-nine SNPs were genotyped in the current study. The C allele of rs6494629 was less frequent in KBD than in the controls (OR = 0.63, p = 0.011). Based on the CTD database, PPARG, ADAM12, IL6, SMAD3, and TIMP2 were identified to interact with selenium, sodium selenite, and T-2 toxin. KBD was found to be significantly associated with rs12629751 of PPARG (additive model: OR = 0.46, p = 0.012; dominant model: OR = 0.45, p = 0.049; recessive model: OR = 0.18, p = 0.018), rs1871054 of ADAM12 (dominant model: OR = 2.19, p = 0.022), rs1800796 of IL6 (dominant model: OR = 0.30, p = 0.003), rs6494629 of SMAD3 (additive model: OR = 0.65, p = 0.019; dominant model: OR = 0.52, p = 0.012), and rs4789936 of TIMP2 (recessive model: OR = 5.90, p = 0.024). Immunohistochemistry verified significantly upregulated PPARG, ADAM12, SMAD3, and TIMP2 in KBD compared with OA and normal controls (p < 0.05). Genetic polymorphisms of PPARG, ADAM12, SMAD3, and TIMP2 may contribute to the risk of KBD. These genes could promote the pathogenesis of KBD by disturbing ECM homeostasis.

T-2 toxin induces articular cartilage damage by increasing the expression of MMP-13 via the TGF-β receptor pathway

T-2 toxin pre-disposes individuals to osteoarthritis, Kashin-Beck disease (KBD). The major pathological change associated with KBD is the degradation of the articular cartilage matrix. Herein, we investigated the key molecules that regulate T-2 toxin-mediated cartilage degradation. Potential KBD treatments were also investigated. Sprague Dawley rats were divided into the T-2 toxin group and the control group. The T-2 toxin group received 100 ng/g BW/day, whereas the control group received a similar dose of PBS. The expression of matrix metalloproteinase-13 (MMP-13) and TGF-β receptor I/II (TGF-βRI/II) was analyzed using immunohistochemical staining. C28/I2 chondrocytes were exposed to TGF-βRI/II binding inhibitor (GW788388) for 24 h before incubation in different T-2 toxin concentrations (0, 6, 12, and 24 ng/mL for 72 h). The expression of mRNA for TGF-βRI/II, MMP-13 and proteins for MMP-13, and Smad-2 in chondrocytes were analyzed using RT-PCR and western blot, respectively. Safranin O staining revealed that T-2 toxin treatment modulated the expression of articular cartilage matrix. On the other hand, T-2 toxin treatment sharply increased the expression of MMP-13, TGF-βRI, and TGF-βRII in the rat cartilages. Interestingly, blocking the TGF-βRs-smad 2 signaling pathway using GW788388 abrogated the effect of T-2 toxin on upregulating MMP-13 expression. The expression of MMP-13 in chondrocytes induced with T-2 toxin is regulated via the TGF-βRs signaling pathway. As such, inhibiting the expression of TGF-βRs is a potential KBD treatment.

Upregulated expression of transforming growth factor-β receptor I/II in an endemic Osteoarthropathy in China

Background

Kashin–Beck disease (KBD) is a chronic, deforming, endemic osteochondropathy that begins in patients as young as 2–3 years of age. The pathogenesis of KBD remains unclear, although selenium (Se) deficiency and T-2 toxin food contamination are both linked to the disease. In the present study, we evaluated transforming growth factor-β receptor (TGF-βR I and II) levels in clinical samples of KBD and in pre-clinical disease models.

Methods

Human specimens were obtained from the hand phalanges of eight donors with KBD and eight control donors. Animal models of the disease were established using Sprague–Dawley rats, which were fed an Se-deficient diet for 4 weeks and later administered the T-2 toxin. Cartilage cellularity and morphology were examined by hematoxylin and eosin staining. Expression and localization of TGF-βRI and II were evaluated using immunohistochemical staining and western blotting.

Results

In the KBD samples, chondral necrosis was detected based on cartilage cell disappearance and alkalinity loss in the matrix ground substance. In the necrotic areas, TGF-βRI and II staining were strong. Positive percentages of TGF-βRI and II staining were higher in the cartilage samples of KBD donors than in those of control donors. TGF-βRI and II staining was also increased in cartilage samples from rats administered T-2 toxin or fed on Se-deficient plus T-2 toxin diets.

Conclusion

TGF-βRI and II may be involved in the pathophysiology of KBD. This study provides new insights into the pathways that contribute to KBD development.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04939-6.

Long-term outcomes of arthroscopic debridement of the knee in adults with Kashin-Beck disease: an 18-year follow-up

OBJECTIVE

Kashin-Beck disease (KBD) is an endemic degenerative joint disease with a high disability rate. We retrospectively evaluated the 18-year clinical follow-up outcomes of adult patients with KBD who underwent arthroscopic debridement for knee osteoarthritis.

METHODS

Thirty-one patients with KBD (31 knees) underwent arthroscopy for knee osteoarthritis. The visual analog scale (VAS) score, walking distance, knee mobility, and patients' self-evaluated improvement in clinical symptoms were retrospectively evaluated before and 18 years after the operation.

RESULTS

The patients' self-evaluated clinical symptoms showed considerable improvement at 2, 6, and 8 years after surgery but deteriorated at 10 and 18 years after surgery. Knee mobility was greater after than before arthroscopy but decreased from 6 to 18 years postoperatively. The VAS score for knee pain was high before the operation, decreased at 2 years postoperatively, increased at 6 years postoperatively, and was significantly lower at 18 years postoperatively than before surgery. The walking distance was significantly longer at 2, 6, and 8 years postoperatively than preoperatively.

CONCLUSIONS

Arthroscopic treatment may be an effective therapy for adult patients with KBD who develop knee osteoarthritis. In this study, arthroscopy had a long-term effect on patients with KBD who had Kellgren-Lawrence grade <IV osteoarthritis.

Dysregulation of Cells Cycle and Apoptosis in Human Induced Pluripotent Stem Cells Chondrocytes Through p53 Pathway by HT-2 Toxin: An in vitro Study

Kashin–Beck disease (KBD) mainly damages growth plate of adolescents and is susceptible to both gene and gene–environmental risk factors. HT-2 toxin, which is a primary metabolite of T-2 toxin, was regarded as one of the environmental risk factors of KBD. We used successfully generated KBD human induced pluripotent stem cells (hiPSCs) and control hiPSCs, which carry different genetic information. They have potential significance in exploring the effects of HT-2 toxin on hiPSC chondrocytes and interactive genes with HT-2 toxin for the purpose of providing a cellular disease model for KBD. In this study, we gave HT-2 toxin treatment to differentiating hiPSC chondrocytes in order to investigate the different responses of KBD hiPSC chondrocytes and control hiPSC chondrocytes to HT-2 toxin. The morphology of HT-2 toxin-treated hiPSC chondrocytes investigated by transmission electron microscope clearly showed that the ultrastructure of organelles was damaged and type II collagen expression in hiPSC chondrocytes was downregulated by HT-2 treatment. Moreover, dysregulation of cell cycle was observed; and p53, p21, and CKD6 gene expressions were dysregulated in hiPSC chondrocytes after T-2 toxin treatment. Flow cytometry also demonstrated that there were significantly increased amounts of late apoptotic cells in KBD hiPSC chondrocytes and that the mRNA expression level of Fas was upregulated. In addition, KBD hiPSC chondrocytes presented stronger responses to HT-2 toxin than control hiPSC chondrocytes. These findings confirmed that HT-2 is an environmental risk factor of KBD and that p53 pathway interacted with HT-2 toxin, causing damaged ultrastructure of organelles, accelerating cell cycle in G1 phase, and increasing late apoptosis in KBD hiPSC chondrocytes.

Differences in quinone redox system of humic substances between endemic and disease-free areas in Kashin-Beck disease-affected Changdu Region, Tibet, China

Kashin-Beck disease (KBD) is an endemic disease in China with the highest incidence rate in Tibet region. Promoted generation of oxygen free radicals by semiquinone structure of humic substance (HS) in drinking water was considered to be one of its pathogeneses. Therefore, detailed analysis of HS was performed in water and sediment samples collected from three endemic and three disease-free areas in Changdu Region, Tibet, China. After purification of the HS in the samples, the fractions of HS were characterized using electron paramagnetic resonance, ¹³C nuclear magnetic resonance, fluorescence spectroscopy with parallel factor analysis and Fourier transform infrared spectroscopy (FTIR). The organic carbon content of HS did not show a significant difference between endemic and disease-free areas or correlation with KBD-associated morbidity. Except FTIR, all techniques succeeded in characterization of the quinone redox system, indicating their validity and consistency. The quinone redox system in aquatic HS exhibited significantly higher level of the following indexes in endemic areas than disease-free areas: semiquinone radical content of fulvic acid (FA) (p < 0.05), aromaticity of FA (p < 0.05), fluorescence intensity (per gram carbon) of reduced quinone-like component of FA (p < 0.05) and humic acid (HA) (p < 0.1). Semiquinone radical content (r = 0.781, p < 0.1), aromaticity of FA (r = 0.891, p < 0.05), intensity of oxidized quinone-like component (r = 0.875, p < 0.05) and reduced quinone-like component of FA (r = 0.793 p < 0.1) showed medium to strong correlation with KBD-associated morbidity. Generally, the content of reduced quinone and aquatic FA showed stronger differences between endemic and disease-free areas than oxidized quinone and aquatic HA, respectively. The quinone redox system in sediment HS did not show any significant relationship with KBD. The present study is a successful attempt to combine the three indexes, semiquinone radical content, aromaticity and fluorescence intensity, in characterizing quinone redox system in HS, facilitating more comprehensive understanding of the characteristics of HS in KBD-affected regions.

Genome-Wide Differentially Methylated Region Analysis to Reveal Epigenetic Differences of Articular Cartilage in Kashin-Beck Disease and Osteoarthritis

Kashin-Beck disease (KBD) is a degenerative osteoarticular disorder, and displays the significant differences with osteoarthritis (OA) regarding the etiology and molecular changes in articular cartilage. However, the underlying dysfunctions of molecular mechanisms in KBD and OA remain unclear. Here, we primarily performed the various genome-wide differential methylation analyses to reveal the distinct differentially methylated regions (DMRs) in conjunction with corresponding differentially methylated genes (DMGs), and enriched functional pathways in KBD and OA. We identified a total of 131 DMRs in KBD vs. Control, and 58 DMRs in OA vs. Controls, and the results demonstrate that many interesting DMRs are linked to DMGs, such as SMOC2 and HOXD3, which are all key genes to regulate cartilage/skeletal physiologic and pathologic process, and are further enriched in skeletal system and limb-associated pathways. Our DMR analysis indicates that KBD-associated DMRs has higher proportion than OA-associated DMRs in gene body regions. KBD-associated DMGs were enriched in wounding and coagulation-related functional pathways that may be stimulated by trace elements. The identified molecular features provide novel clues for understanding the pathogenetic and therapeutic studies of both KBD and OA.

Roles of glycoprotein glycosylation in the pathogenesis of an endemic osteoarthritis, Kashin–Beck disease, and effectiveness evaluation of sodium hyaluronate treatment

Background/aim

We aimed to explore the roles of glycoprotein glycosylation in the pathogenesis of Kashin–Beck disease (KBD), and evaluated the effectiveness of sodium hyaluronate treatment.

Materials and methods

Blood and saliva were collected from KBD patients before and after the injection of sodium hyaluronate. Normal healthy subjects were included as controls. Saliva and serum lectin microarrays and saliva and serum microarray verifications were used to screen and confirm the differences in lectin levels among the three groups.

Results

In saliva lectin microarray, bindings to Sophora japonica agglutinin (SJA), Griffonia (Bandeiraea) simplicifolia lectin I (GSL-I), Euonymus europaeus lectin (EEL), Maackia amurensis lectin II (MAL-II), Sambucus nigra lectin (SNA), Hippeastrum hybrid lectin (HHL), and Aleuria aurantia lectin (AAL) were higher in the untreated KBD patients than in the control group. Increased levels of HHL, MAL-II, and GSL-I in the untreated KBD patients discriminated them in particular from the treated ones. Jacalin was lower in the untreated KBD patients compared to the treated KBD and control groups. In serum lectin microarray, HHL and peanut agglutinin (PNA) were increased in the untreated KBD group in comparison to the control one. AAL, Phaseolus vulgaris agglutinin (E+L) (PHA-E+L), and Psophocarpus tetragonolobus lectin I (PTL-I) were lower in the untreated KBD patients compared to the treated KBD and control groups. Hyaluronate treatment appeared to normalize SNA, AAL, and MAL-II levels in saliva, and HHL, PNA, AAL, PTL-I, and PHA-E+L levels in serum. Saliva reversed microarray verification confirmed significant differences between the groups in SNA and Jacalin, in particular for GSL-I levels, while serum reversed microarray verification indicated that HHL, PNA, and AAL levels returned to normal levels after the hyaluronate treatment. Lectin blot confirmed significant differences in HHL, AAL, and Jacalin in saliva, and HHL, PNA, PHA-E+L, and AAL in serum.

Conclusion

HHL in saliva and serum may be a valuable diagnostic biomarker of KBD, and it may be used as follow-up for the hyaluronate treatment.

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

To investigate selenium (Se) concentrations in serum of patients with rheumatoid arthritis (RA), osteoarthritis (OA), and Kashin-Beck disease (KBD), together with the effect of Se supplement (chondroitin sulfate [CS] nano-Se [SeCS]) on CS structure-modifying sulfotransferases in KBD chondrocyte. Fifty serum samples from each group with aged-matched (40-60 years), normal control (N), RA, OA, and KBD (25 males and females, respectively) were collected to determine Se concentrations. Furthermore, the KBD chondrocytes were divided into two groups following the intervention for 24 h: (a) non-treated KBD group and (b) SeCS-treated KBD group (100 ng/mL SeCS). The ultrastructural changes in chondrocytes were observed by transmission electron microscopy (TEM). Live/dead staining was used to observe cell viability. The expression of CS-modifying sulfotransferases including carbohydrate sulfotransferase 12, 13, and 15 (CHST-12, CHST-13, and CHST-15, respectively), and uronyl 2-O-sulfotransferase (UST) were examined by quantitative real-time polymerase chain reaction and western blotting analysis after SeCS intervention. The Se concentrations in serum of KBD, OA, and RA patients were lower than those in control. In OA, RA, and control, Se concentrations were higher in male than in female, while it is opposite in KBD. In the cell experiment, cell survival rate and mitochondrial density were increased in SeCS-treated KBD groups. Expressions of CHST-15, or CHST-12, and CHST-15 on the mRNA or protein level were significantly increased. Expression of UST slightly increased on the mRNA level, but no change was visible on the protein level. Se deficiency in serum of RA, OA, and KBD was observed. SeCS supplemented in KBD chondrocytes improved their survival rate, ameliorated their ultrastructure, and increased the expression of CS structure-modifying sulfotransferases.

Abnormal expression of chondroitin sulfate sulfotransferases in the articular cartilage of pediatric patients with Kashin-Beck disease

The objective of this study is to investigate the expression of enzymes involved in the sulfation of articular cartilage from proximal metacarpophalangeal (PMC) joint cartilage and distal metacarpophalangeal (DMC) joint cartilage in children with Kashin-Beck disease (KBD). The finger cartilage samples of PMC and DMC were collected from KBD and normal children aged 5-14 years old. Hematoxylin and eosin staining as well as immunohistochemical staining were used to observe the morphology and quantitate the expression of carbohydrate sulfotransferase 3 (CHST-3), carbohydrate sulfotransferase 12 (CHST-12), carbohydrate sulfotransferase 13 (CHST-13), uronyl 2-O-sulfotransferase (UST), and aggrecan. In the results, the numbers of chondrocyte decreased in all three zones of PMC and DMC in the KBD group. Less positive staining cells for CHST-3, CHST-12, CHST-13, UST, and aggrecan were observed in almost all three zones of PMC and DMC in KBD. The positive staining cell rates of CHST-12 were higher in superficial and middle zones of PMC and DMC in KBD, and a significantly higher rate of CHST-13 was observed only in superficial zone of PMC in KBD. In conclusion, the abnormal expression of chondroitin sulfate sulfotransferases in chondrocytes of KBD children may provide an explanation for the cartilage damage, and provide therapeutic targets for the treatment.

Relationship of the mobile forms of calcium and strontium in soils with their accumulation in meadow plants in the area of Kashin-Beck endemia

This study was aimed at assessment of strontium and calcium mobility in soils and their accumulation with plants in the areas endemic for Kashin-Beck disease in Eastern Transbaikalia. The strontium and calcium mobility levels were determined using the method of sequential chemical extraction for 7 samples of meadow soils collected from the endemic region and 7 soil samples taken from conditionally control sites. To measure the Ca and Sr levels in the soil and plant samples, XRF analysis and AAS were used. The increased strontium level in the meadow soils of the endemic areas is accompanied by the element's higher mobility. The highest strontium yield was observed in the course of soil extraction using 1 M ammonium acetate, while the soils taken from the control sites gave lower amounts of the trace element. Furthermore, there is a positive correlation between the amount of the strontium extracted and its content in plants (r = + 0.86 - 0.98). At the sequential chemical extraction of calcium from the soils using the above method, the calcium yield was maximal in the ammonium acetate fraction (background sites) and in ammonium acetate and 6 M HCl fractions (endemic areas). The correlation between the amount of the calcium extracted in 1 M ammonium acetate and the macroelement levels found in plants was + 0.968. In addition, a peculiarly high accumulation of strontium in various willow species as compared to other meadow plants was revealed for the first time ever. Thus, the work introduces new data into the trace element biogeochemistry and environmental monitoring.

Screening for differentially expressed circRNA between Kashin-Beck disease and osteoarthritis patients based on circRNA chips

OBJECTIVE

This research aims to explore differentially expressed circRNA between OA and KBD and potential diagnostic biomarkers.

METHODS

Total RNA was extracted from 5 pairs of KBD and OA knee joint cartilage specimens, and the expression of circRNAs was analyzed by Chip Scanning Analysis. The microarray data was verified by quantitative polymerase chain reaction (qRT-PCR). CircRNA-miRNA network was constructed to predict targeting microRNAs of circRNA genes. Peripheral blood samples from 25 KBD patients and 25 OA patients were collected for verification by qRT-PCR. Diagnostic value was evaluated by the area under the receiver operator characteristic (ROC) curve.

RESULTS

A total of 1627 circRNAs were differentially expressed between OA and KBD. Five bone and joint disease-related circRNAs were chosen for qRT-PCR validation. The difference in expression profile of hsa_circRNA_0020014 was confirmed by qRT-PCR, and its circRNA-miRNA regulation network was set up. The ROC curve demonstrated that hsa_circ_0020014_CBC1 in peripheral blood could distinguish patients with KBD and OA.

CONCLUSION

The expression profiles of circRNA were significantly different between OA and KBD. hsa_circRNA_0020014 is a potential biomarker for differential diagnosis between these two diseases.

Decreased Expression of CHST-12, CHST-13, and UST in the Proximal Interphalangeal Joint Cartilage of School-Age Children with Kashin-Beck Disease: an Endemic Osteoarthritis in China Caused by Selenium Deficiency

The objective of this study is to investigate changes in the expression of enzymes involved in chondroitin sulfate (CS) sulfation in distal articular surface of proximal interphalangeal joint isolated from school-age children patients with Kashin-Beck disease (KBD), using normal children as controls. Articular cartilage samples were collected from four normal and four KBD children (7-12 years old), and these children were assigned to control and KBD groups. Hematoxylin and eosin (H&E), toluidine blue (TB), and immunohistochemical (IHC) stainings were utilized to evaluate changes in joint pathology and expression of enzymes involved in CS sulfation, including carbohydrate sulfotransferase 12 (CHST-12), carbohydrate sulfotransferase 13 (CHST-13), and uronyl 2-O-sulfotransferase (UST). The correspondence results were examined by semi-quantitative analysis. Compared with the control group, the KBD group showed the following: a significant decrease of total chondrocytes in superficial, middle, and deep layers and deposition of sulfated glycosaminoglycans in extracellular matrix of KBD cartilage were observed; positive staining chondrocytes of CHST-12, CHST-13, and UST were significantly less in superficial zone of KBD cartilage; and CHST-13 positive staining chondrocytes was reduced in deep zone of KBD cartilage. In contrast, the positive staining rates of CHST-12, CHST-13, and UST in KBD were significantly higher than those in the control group. The decreased expression of these enzymes and the physiologic compensatory reaction may be the signs of early-stage KBD. The alterations of CS structure modifying sulfotransferases in finger articular cartilage might play an important role in the onset and pathogenesis of school-age KBD children.

Endemic Kashin-Beck disease: A food-sourced osteoarthropathy

OBJECTIVE

Kashin-Beck disease (KBD) is an endemic osteoarthropathy, which causes disability and heavy socioeconomic burdens. The preventive measures have been taken in the past few decades. However, recent KBD-epidemiological trend and comprehensive effect of its preventive measures need to be evaluated.

METHODS

By employing typical survey, cross-sectional survey, case-control study, intervention trial, and national surveillance, the present study summarizes comprehensive role of KBD-preventive measures.

RESULTS

The endemic KBD is distributed in a long and narrow area of the world. The latest epidemic began in the late 1950s and lasted until the end of 1980s. Epidemiology of the KBD was characterized by early-onset, gender equality, agricultural area, regional discrepancy, family aggregation, annual fluctuation, etc. Multivariate regression analysis suggested that etiology of the KBD was food-related factors such as fungal contamination of grains, selenium deficiency, imbalance of protein intake, etc. A series of intervention measures for KBD control had been implemented since 1990s, and involved more than 300 million residents. National incidences were 22.1% in 1990, 16.0% in 1995, 12.3% in 2000, 5.5% in 2005, 0.38% in 2010, and 0.18 in 2015, respectively. Although new patients were annually decreased, it still affected 22,567,600 inhabitants and there were 574,925 patients in 2016.

CONCLUSIONS

Etiology of the KBD is food-sourced. Its decreased incidence may attribute to an effective implementation of preventive measures. It is possible to eradicate KBD from the earth in the near future.

The Importance of Se-Related Genes in the Chondrocyte of Kashin-Beck Disease Revealed by Whole Genomic Microarray and Network Analysis

Kashin-Beck disease (KBD) is an endemic, chronic, and degenerative osteoarthropathy. Selenium (Se) deficiency plays important role in the pathogenesis of KBD. We aimed to screen Se-related gene from chondrocytes of patients with KBD. Whole-genome oligonucleotide microarrays were used to detect differentially expressed genes. qRT-PCR was used to confirm the microarray results. Comparative Toxicogenomics Database (CTD) was used to screen Se-related genes from differentially expressed genes. Gene Ontology (GO) classifications and network analysis of Se-related genes were constituted by STRING online system. Three hundred ninety-nine differentially expressed genes were obtained from microarray. Among them, 54 Se-related genes were identified by CTD. The qRT-PCR validation showed that four genes expressed similarly with the ones in the microarray transcriptional profiles. The Se-related genes were categorized into 6 cellular components, 8 molecular functions, 44 biological processes, 10 pathways, and 1 network by STRING. The Se-related gene insulin-like growth factor binding protein 2 (IGFBP2), insulin-like growth factor binding protein 3 (IGFBP3), interleukin 6 (IL6), BCL2, apoptosis regulator (BCL2), and BCL2-associated X, apoptosis regulator (BAX), which involved in many molecular functions, biological processes, and apoptosis pathway may play important roles in the pathogenesis of KBD.

Inflammatory cytokine of IL-1β is involved in T-2 toxin-triggered chondrocyte injury and metabolism imbalance by the activation of Wnt/β-catenin signaling

Mycotoxin T-2 exerts a causative role in Kashin-Beck disease (KBD) suffering chondrocyte apoptosis and cartilage matrix homeostasis disruption. Recent research corroborated the aberrant levels of pro-inflammatory cytokine IL-1ß in KBD patients and mycotoxin environment. In the present study, we investigated the relevance of IL-1ß in T-2 toxin-evoked chondrocyte cytotoxic injury and aberrant catabolism. High levels of IL-1ß were detected in serum and cartilages from KBD patients and in T-2-stimulated chondrocytes. Moreover, knockdown of IL-1ß antagonized the adverse effects of T-2 on cytotoxic injury by enhancing cell viability and inhibiting apoptosis. However, exogenous supplementation of IL-1β further aggravated cell damage in response to T-2. Additionally, cessation of IL-1β rescued T-2-elicited tilt of matrix homeostasis toward catabolism by elevating the transcription of collagen II and aggrecan, promoting release of sulphated glycosaminoglycans (sGAG) and TIMP1, and suppressing matrix metalloproteinases production including MMP-1, MMP-3 and MMP-13. Conversely, IL-1β stimulation deteriorated T-2-induced disruption of matrix metabolism balance toward catabolism. Mechanistic analysis found the high activation of Wnt/β-catenin in KBD patients and chondrocytes upon T-2. Furthermore, this activation was mitigated after IL-1β inhibition, but further enhanced following IL-1β precondition. Importantly, blocking this pathway by transfection with β-catenin alleviated the adverse roles of IL-1β on cytotoxic injury and metabolism disorders under T-2 conditioning. Together, this study elucidates a new insight into how T-2 deteriorates the pathological progression of KBD by regulating inflammation-related pathways, indicating a promising anti-inflammation strategy for KBD therapy.

Staged total knee arthroplasty for bilateral complex knee deformities from Kashin-Beck disease and skeletal dysplasia

This study reported two cases of patients with Grade III Kashin-Beck disease (KBD) with skeletal dysplasia concomitant with complex knee deformity and functional limitation treated by staged total knee arthroplasty (TKA). Detailed pre-operative planning, bone resection, and soft tissue balancing in affected knees were performed in the surgeries in this report. The results demonstrated that TKA could correct lower limb alignment, alleviate knee pain, improve function, and provide good quality of life in people with KBD. Surgical efficacy is still lower compared with treatment for osteoarthritis; contributing factors include weak muscle strength, severe deformity and unequal length of the lower limb, weak extensor apparatus of the knee, and patient-specific factors.

Reliability and validity of the 12-item WHODAS 2.0 in patients with Kashin-Beck disease

The purpose of this study was to check the reliability and validity of the 12-item Chinese version of the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) for the assessment of disability in patients with Kashin-Beck disease (KBD). We recruited 219 patients with KBD from the high-risk KBD area in the Shaanxi province, using stratified multistage random sampling. We assessed each patient using the Chinese version of the 12-item WHODAS 2.0 and the Western Ontario and McMaster Universities Index of Osteoarthritis (WOMAC). Statistical evaluations of the instruments consisted of Cronbach's alpha, intraclass correlation coefficient (ICC), confirmatory factor analysis (CFA), and Pearson's correlation coefficient. Cronbach's alpha and ICC for the six domains ranged from 0.704 to 0.906 and 0.690 to 0.852, respectively. A six-factor structure fits the data well (CFI = 0.967, TLI = 0.944, RMSEA = 0.08). Regarding convergent validity, the four domains of the 12-item WHODAS 2.0 (getting around, self-care, life activity, and participation) showed moderate-to-strong correlation for all three domains of the WOMAC (0.428 < |r| < 0.804). Regarding divergent validity, the two domains of the 12-item WHODAS 2.0 (understanding and communication, and getting along with people) showed weak correlation for the three domains of WOMAC (0.182 < |r| < 0.295). The Chinese version of 12-item WHODAS 2.0 questionnaire is a reliable and valid instrument when administered to KBD patients.

Genetic association, mRNA and protein expression analysis identify ATG4C as a susceptibility gene for Kashin-Beck disease

OBJECTIVE

Recent study observed defective autophagy in chondrocytes with Kashin-Beck Disease (KBD). To clarify the potential role of autophagy-related ATG4C gene in the development of KBD, we conducted an integrative analysis of genetic association, messenger ribonucleic acid (mRNA) and protein expression of ATG4C in KBD patients.

METHODS

1026 subjects (559 KBD patients and 467 healthy cases) were enrolled in discovery association study. Four single nucleotide polymorphisms (SNPs) of ATG4C gene (rs11208030, rs4409690, rs12097658 and rs6587988) were genotyped by Sequenom MassARRAY platform. Association analysis was conducted by PLINK software. The significant SNPs of ATG4C were replicated using an independent sample of 899 subjects (including 90 KBD patients and 809 healthy controls). Ungenotyped SNPs in ATG4C gene were imputed by IMPUTE 2.0. Knee cartilage specimens were collected from five KBD patients and five healthy subjects. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot were performed to compare the mRNA and protein expression levels of ATG4C between KBD cartilage and control cartilage.

RESULTS

We observed significant association between KBD and rs11208030 (P value = 0.003), rs4409690 (P value = 0.004), rs12097658 (P value = 0.003) and rs6587988 (P value = 0.003) in both discovery and replication samples. The mRNA expression level of ATG4C (ratio = 0.168, P value = 0.007) in KBD chondrocytes was significantly lower than that in normal chondrocytes. Western blot (P value < 0.001) further confirmed the reduced expression of ATG4C protein in both KBD cartilage and chondrocytes.

CONCLUSION

Our results strongly suggest that ATG4C was a novel autophagy-related susceptibility gene of KBD.

Distribution and translocation of selenium from soil to highland barley in the Tibetan Plateau Kashin-Beck disease area

Kashin-Beck disease (KBD), which is still active and severe in the Tibetan Plateau, is considered to be a kind of selenium (Se)-deficient disease. Highland barley as the most popular staple food in the Tibetan Plateau is one of the dominant Se sources for local people. To improve Se levels in crops in the Tibetan Plateau KBD area, the distribution and translocation of Se from soil to highland barley in both non-KBD and KBD endemic areas were investigated. The results showed that Se levels in highland barley were too low to meet the minimum requirements of human for daily intake of Se. The total Se concentrations of highland barley fractions in KBD areas were lower than that in non-KBD areas (grain P = 0.238; straw P = 0.087; root P = 0.008). However, no significant difference was observed in corresponding cultivated soil Se between the two areas (P = 0.993). The calculation of Se transfer factors indicated that the restricting step for Se translocation was from soil to root. Water-soluble, exchangeable and fulvic acid-bound Se fractions in the soil are key species dominating in this transfer process, according to their significant correlations with root Se. Se transfer from soil to root significantly increases as the pH value of soil increases (P = 0.007), and soil organic matter content decreases (P = 0.019). The information obtained may have considerable significance for proposing effective agricultural measures to increase grain Se in KBD endemic areas.

Reliability and validity of the EQ-5D-3L for Kashin-Beck disease in China

BACKGROUND

Kashin-Beck Disease (KBD) is an endemic osteoarthropathy in areas which extend from the North-East to the South-West of China. Most of the patients with KBD suffer multiple dysfunctions in major joints causing decreased health status. However because of their low education level and unique living habits, it is hard to find tools to measure the health-related quality of life (HRQOL). European quality of life (EQ-5D-3L) patient-reported instrument is widely used to measure HRQOL. This study aimed to establish the validity and reliability of the Chinese version of the EQ-5D-3L for evaluating HRQOL of KBD individuals in rural area.

METHODS

368 individuals who were suffering from KBD were recruited through stratified multistage random sampling from Shaanxi province, China. The EQ-5D-3L and the WHOQOL-BREF were administrated in each individual by face to face interview. Test-retest reliability was assessed at 10-14 days intervals. The test-retest reliability was measured by calculating the Kappa coefficients for EQ-5D-3L five dimensions. For the EQ VAS, the intraclass correlation coefficient (ICC) was computed. Convergent and divergent analysis, construct validity was established using Spearman's rank correlation between the EQ-5D-3L and the WHOQOL-BREF. Known groups' validity was examined by comparing groups with a priori expected differences in health-related quality of life (HRQOL).

RESULTS

For 362 individuals (98%), comprehensive data of all the EQ-5D-3L dimensions were available. Kappa values of the EQ-5D-3L five items ranged from 0.324 to 0.554. ICC of the EQ VAS was 0.497. For convergent validity, the three items (self-care, usual activity, and mobility) of EQ-5D-3L, index scores, and VAS showed moderate correlations with the physical health domain of the WHOQOL-BREF (r absolute value ranged from 0.339 to 0.475). For divergent validity, the 5 items of EQ-5D-3L showed weak or no correlations with environment and social relationship domains of WHOQOL-BREF. The Chinese EQ-5D-3L clearly demarcated between groups which were reporting severe disease degree, poorer general health, more number of painful joints with worse HRQOL.

CONCLUSIONS

The EQ-5D-3L Chinese Version demonstrated fair to moderate levels of test-retest reliability and adequate construct validity in KBD individuals in China.

Accidental or linked: separated odontoid process fused to the enlarged anterior arch of the atlas associated with atlantoaxial subluxation in a Kashin-Beck disease patient

PURPOSE

KBD is an endemic disease affecting the epiphyseal growth plate and articular cartilage of multiple joints, resulting in extremities' deformation and skeletal dysplasia. More attention has been paid to the visible deformed extremities instead of inconspicuous spinal condition. There is a lack of reports concerning the spinal radiological features, especially for the atlantoaxial joint. The aim of this paper is to report a case of a Kashin-Beck disease (KBD) patient diagnosed with atlantoaxial subluxation, concomitant with separated odontoid process fused to the enlarged anterior arch of the atlas.

METHODS

We report the case of a 60-year-old woman with 54 years' history of KBD complaining of occipitocervical pain, decreasing motor strength and sensory function of both upper and lower extremities. Subsequent radiological examinations of lateral plain radiography, computed tomography scans and magnetic resonance imaging were performed to reveal these rare characteristics of atlantoaxial joint in this patient. Then, we review the associated articles to postulate whether this anomaly is accidental or linked in a KBD patient.

RESULTS

She had an extremely rare variant with three aspects of characteristics: atlantoaxial subluxation concurrent with severe spinal canal stenosis and spinal cord compression, odontoid process separating from the body of axis, and the enlarged anterior arch of the atlas fusion with odontoid process. Comparing with the congenital anomaly of atlantoaxial joint, we postulated that this aetiology of anomaly might be linked to the acquired form attributed to the histopathology of KBD, rather than an accidental event.

CONCLUSIONS

The anomaly of atlantoaxial joint might occur in KBD patients. Larger numbers of KBD candidates with earlier symptoms are recommended for radiological examinations of atlantoaxial joint, especially for the adolescents. Spinal surgeons are suggested to involve the research of the spinal anatomy and variation for the prevention and earlier therapy for KBD patients.

Prevalence of Selenium, T-2 Toxin, and Deoxynivalenol in Kashin-Beck Disease Areas in Qinghai Province, Northwest China

The aim of this study was to determine the levels of selenium, T-2 toxin, and deoxynivalenol (DON) contamination in Kashin-Beck disease (KBD) areas and provide information for understanding the high prevalence of KBD in Qinghai Province. A total of 183 subjects were chosen in a KBD-prevalent county (Guide County) and a non-KBD county (Huangzhong County) in Qinghai Province, northwestern China, and the samples of wheat flour, soil, drinking water and blood, urine, and hair of children were collected from these residents. The selenium concentrations from all these sources were determined using atomic fluorescence spectrophotometry. The levels of T-2 toxin and DON contamination in the wheat flour samples were assayed using HPLC-MS/MS. The average selenium content in the soil, drinking water, and wheat flour samples from KBD areas were 26.93 ± 10.06 μg/kg, 0.097 ± 0.038 μg/L, and 9.50 ± 7.17 μg/kg, respectively. Among these, the selenium levels in the drinking water and wheat flour samples from the KBD endemic county were significantly lower than those from the non-KBD county. For the selenium nutrient status, only the hair selenium concentration of children from the KBD endemic county was significantly lower than that from the non-KBD county. The contents of T-2 toxin in all wheat samples were below the detection limit (0.4 μg/kg). The levels of DON contamination in wheat flour samples from KBD and non-KBD children's households within the KBD endemic county were relatively higher, with average levels of 302 ± 49 and 280 ± 48 μg/kg, respectively. The DON level of wheat flour samples from the children's households in the non-KBD county was significantly lower than that from the KBD endemic county. These results suggest that the lower selenium status in Guide County still remains. While the selenium nutritional status of the local children has improved to some extent, partly due to the introduction of food produce from nonlocal areas. DON contamination in the wheat flour may be involved in the fluctuating high prevalence rates of KBD in children in the KBD endemic Guide County in Qinghai Province.

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.

Effects of sodium selenite on c-Jun N-terminal kinase signalling pathway induced by oxidative stress in human chondrocytes and c-Jun N-terminal kinase expression in patients with Kashin-Beck disease, an endemic osteoarthritis

The c-Jun N-terminal kinases (JNK) are members of the mitogen-activated protein kinase family and are activated by environmental stress. Se plays an important role in the biological pathways by forming selenoprotein. Selenoproteins have been shown to exhibit a variety of biological functions including antioxidant functions and maintaining cellular redox balance, and compromise of such important proteins would lead to oxidative stress and apoptosis. We examined the expression levels of JNK in Kashin-Beck disease (KBD) patients, tested the potential protective effects of sodium selenite on tert-butyl hydroperoxide (tBHP)-induced oxidative injury and apoptosis in human chondrocytes as well as its underlying mechanism in this study. We produced an oxidative damage model induced by tBHP in C28/I2 human chondrocytes to test the essential anti-apoptosis effects of Se in vitro. The results indicated that the expression level of phosphorylated JNK was significantly increased in KBD patients. Cell apoptosis was increased and molecule expressions of the JNK signalling pathway were activated in the tBHP-injured chondrocytes. Na2SeO3 protected against tBHP-induced oxidative stress and apoptosis in cells by increasing cell viability, reducing reactive oxygen species generation, increasing Glutathione peroxidase (GPx) activity and down-regulating the JNK pathway. These results demonstrate that apoptosis induced by tBHP in chondrocytes might be mediated via up-regulation of the JNK pathway; Na2SeO3 has an effect of anti-apoptosis by down-regulating the JNK signalling pathway.

Salt-Rich Selenium for Prevention and Control Children with Kashin-Beck Disease: a Meta-analysis of Community-Based Trial

Kashin-Beck disease (KBD) in western China is not well controlled. The objective of this study is to evaluate prevention and control children with KBD through a meta-analysis of a community-based trial. Web of knowledge, PubMed, Elsevier, the Chinese National Knowledge Infrastructure (CNKI), VIP and Wanfang data had been electronically searched up to February 2015. Search terms included the trial terms "Salt rich selenium" and "Kashin-Beck disease." Eligible studies were prospective trials of salt-rich selenium in endemic villages. Data extraction was performed by two authors using predefined data fields that also included quality evaluation. Of 292 potentially relevant articles initially screened, reporting 11 community-based trials with a total enrollment of 2652 participants were included, from five provinces in China. The pooled odds ratios (OR) and 95 % confidence intervals (CI) of primary prevention in healthy children were 0.16 and 0.08∼0.33, respectively. The OR and 95 % CI of clinical improvement in KBD children were 6.57 and 3.33∼12.93, respectively. The OR of repairing rate of metaphysis lesions was 5.53 (95 % CI 2.92∼10.47) based on X-ray film, which was statistically significantly different in favor of salt-rich selenium. The combined standard mean difference (SMD) of selenium content in hair was 2.54 (95 % CI 1.21∼3.87) which was significantly higher in selenium group. Current evidence showed that supplement salt-rich selenium was effective in reducing new incidence in healthy children and clinical improvement including repairing metaphysis lesions instead of repairing distal end of phalanx lesions in KBD children.

Hair Selenium Levels of School Children in Kashin-Beck Disease Endemic Areas in Tibet, China

Previous studies have shown that the selenium (Se) deficiency is an important factor for the etiology of Kashin-Beck disease (KBD). Although KBD is presently controlled in most regions of China, it is still active in the Tibetan Plateau. The present study aimed to assess the nutritional status of selenium in school children by using the Se level in hair as a biomarker in KBD endemic areas of Lhasa in Tibet, China. Hair samples of 155 school children aged 6-15 years were collected in both KBD areas and non-KBD areas of Lhasa in 2013. The Se level in the hair samples was determined by inductive coupled plasma mass spectrometry (ICP-MS). The average concentration of Se in children's hair was 0.232 μg/g in KBD areas of Lhasa, which was significantly higher than the data reported decades ago. A significant difference in hair Se was observed between the boys (0.255 μg/g) and the girls (0.222 μg/g) in the studied KBD areas (P < 0.01, Mann-Whitney U test), but hair Se did not vary by age or region. School children in KBD endemic areas in Lhasa likely have improved Se status as a result of high Se content staple food substitution with the enforcement of Free Education Policy and Nutrition Improvement Plan in Tibet. Nevertheless, there were still 20.3 % of students with low Se status (hair Se <0.20 μg/g), which showed that Se status of school children was also partly affected by low Se environment in KBD endemic areas of Lhasa.

Long-Term Efficacy of Arthroscopic Debridement on Knee Osteoarthritis in Patients with Kashin-Beck Disease

Kashin-Beck Disease (KBD) is a chronic and degenerative joint disease with decreased health conditions causing major functional limitations and disability. In this study, we investigated the long-term clinical outcomes of arthroscopic debridement for knee osteoarthritis in KBD patients with Kellgren-Lawrence I-III classification. 31 KBD patients underwent arthroscopic debridement and 24 of them were followed up 8 years after the surgery. The Lysholm scores, femorotibial angle (FTA), and joint space angle (JSA) of the knees were assessed and compared preoperatively and postoperatively to evaluate the clinic outcome. Our results showed that the Lysholm scores, but not the FTA or JSA, of these patients were significantly improved 8 years after the therapy, suggesting that arthroscopic surgery has long-term efficacy in KBD patients with Kellgren-Lawrence I-III classification.

Cytoskeleton remodeling and oxidative stress description in morphologic changes of chondrocyte in Kashin-Beck disease

Kashin-Beck disease (KBD) is a kind of deformity disease involved in cytoskeleton and inner homeostasis regulation. The enrichment analysis of bioprocess, networks, and related disease set were performed. The development regulation, metabolic process, and apoptosis were important procession in KBD; it revealed the up-regulated process in removal of superoxide radicals, glycolysis and glucose catabolic process, regulation of cytoskeleton rearrangement and phagosome in antigen presentation. Morphological changes of KBD chondrocyte were investigated by transmission electronic microscopy compare with the normal one. The ultrastructure of KBD chondrocyte referred to oxidative stress and metabolic dysfunction has been found.

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.

Oxidative stress and status of antioxidant enzymes in children with Kashin-Beck disease

OBJECTIVES

To clarify whether there is oxidative stress in Kashin-Beck disease (KBD) and if cartilage damage from reactive oxygen species (ROS) and oxidative stress mediate the chondral necrosis in articular cartilage of KBD.

METHODS

We recruited 64 KBD patients, 46 healthy children from severely affected KBD regions, 81 healthy children from a non-severely affected KBD endemic regions, and 91 healthy control children from a non-KBD region. Ten patients with KBD from the non-severely affected KBD regions were included in the experiment. The 2,3-DAN fluorescence technique was used to test selenium in the hair and blood. The biochemical techniques used to test the indicators of oxidative stress included thiobarbituric acid reactive substances (TBARS) levels, and antioxidant enzyme activities in serum samples. Histochemical staining was used to detect proteoglycans in cartilage sections. The 4-hydroxy-2-nonenal (4-HNE) and 8-hydroxydeoxyguanisine (8-OHdG) were localized by immunohistochemistry.

RESULTS

The levels of TBARS in serum were significantly increased in KBD children. The levels of antioxidants in serum were significantly higher in both KBD and normal children from KBD regions than in the normal children from non-KBD regions. The percentage of chondrocytes staining for 4-HNE and 8-OHdG in KBD patients was significantly higher than in controls. Staining for 4-HNE and 8-OHdG in KBD patients was prominent in all zones of articular cartilage, especially in the necrotic chondrocytes of the deep zone.

CONCLUSION

KBD is an oxidative stress-related disease, and the oxidative stress in cartilage contributes to the pathology of cartilage damage in KBD.

An animal model of Kashin-Beck disease induced by a low-nutrition diet and exposure to T-2 toxin

OBJECTIVE

We investigated the combined roles of a low-nutrition diet (low levels of protein, iodine, and selenium) and T-2 toxin in bone development and to establish an experimental animal model of Kashin-Beck disease (KBD) that reliably mimics the disease's pathological changes for further study of the pathogenesis and prevention of the disease.

METHODS

Sprague-Dawley rats were randomly divided among four groups: group A, normal diet; group B, normal diet plus T-2 toxin; group C, low-nutrition diet; and group D, low-nutrition diet plus T-2 toxin exposure. The radiographic and histopathological changes in the tibial growth zone, plate cartilage and metaphysis were examined.

RESULTS

In group D, all epiphyseal plates were blurred, thin, and irregular. Tibias were significantly shorter in group D than in groups A and B. After 4 weeks, epiphyseal plates showed chondrocyte necrosis, with the more obvious necrosis appearing in groups C and D. The positive rate of lamellar necrosis was significantly higher in group D than in groups B and A (P < 0.01). In group D, metaphyseal trabecular bone was sparse, disordered, and disrupted, and massive transverse trabecular bone appeared in the metaphysis at 12 weeks.

CONCLUSIONS

A rat model of KBD induced by a low-nutrition diet and T-2 toxin exposure demonstrated radiographic and histopathological abnormalities of the proximal epiphyseal plate and the tibial metaphysis that are very similar to the bone changes found in patients with KBD. This animal model will be helpful for further study of the pathogenesis and prevention of KBD.