The prevalence of mycotoxins in Kashin-Beck disease

Mycotoxins and bone growth: a review of the literature on associations between xenobiotic exposure and bone growth and development

Mycotoxins are secondary metabolites of fungi that are known to be associated with linear growth faltering because of their impact on inflammation, intestinal damage, inhibition of protein synthesis, and micronutrient absorption. In this narrative review, we aim to extend this analysis to further explore associations between mycotoxins (aflatoxins, ochratoxins, trichothecenes including deoxynivalenol, T-2 toxin, and fumonisins) and long-bone growth, particularly during the saltatory periods of development. Linear growth is a direct function of skeletal development and long-bone growth. We therefore explored biological pathways and mechanisms of impact of these toxins in both animal and human studies, in addition to the epidemiology literature (post-2020). Given what is known of the effects of individual and combinations of mycotoxins based on the animal literature, we have identified a need for further research and examination of how these toxins and exposures may be studied in humans to elucidate the downstream impact on bone-related biomarkers and anthropometric indices used to identify and predict stunting in population-based studies.

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

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

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.

Minerals and Trace Elements Intakes and Food Consumption Patterns of Young Children Living in Rural Areas of Tibet Autonomous Region, P.R. China: A Cross-Sectional Survey

BACKGROUND AND OBJECTIVES

Several studies revealed clinical signs of stunting and rickets among rural populations of Tibet Autonomous Region (T.A.R.), and especially amid children. Further, these populations are affected by a bone disease named Kashin-Beck disease (KBD). However, little is known about the dietary status of this population. This survey aimed to assess the usual intakes of young Tibetan children living in rural areas around Lhasa for energy, water, and ten minerals and trace elements (Na, K, Ca, P, Mg, Fe, Zn, Cu, Mn, and Se) involved in bone metabolism.

DESIGN

A cross-sectional survey was designed. Totally, 250 pre-school children aged 3-5 years living in rural areas were enrolled. The 24-h food recall method was used to collect the intakes for two days, during two different seasons (September 2012 and April 2013). Because Tibetan foods are mainly derived from local agriculture and artisanal production, a combination of food composition tables was compiled, including specific and local food composition data.

RESULTS

The Chinese dietary recommended intakes are not met for most of the elements investigated. Intake of sodium is much too high, while usual intakes are too low for K, Ca, Zn, Cu, and Se. Bioavailability of Ca, Fe, and Zn may be of concern due to the high phytic acid content in the diet.

CONCLUSION

These nutrient imbalances may impact growth and bone metabolism of young Tibetan children. The advantages of the implementation of food diversification programs are discussed as well as the relevance of supplements distribution.

Total hip replacement in adult patients with severe Kashin-Beck disease of the hip

Background

The treatment of elderly patients with Kashin-Beck disease (KBD) remains clinically challenging, and clinical data are very lacking. The aim of this study was to retrospectively evaluate pain and functional outcomes following total hip replacement in adult patients with severe KBD of the hip.

Methods

Twenty-two patients (32 hips) with KBD underwent primary hip replacement and were followed for at least 2 years. Radiographic and Clinical assessments were evaluated for each patient at 2 and 4 weeks and at 3, 6 and 12 months after the operation and annually thereafter. The efficacy index included the visual analogue scale (VAS) score, Harris hip score, functional score for adult Tibetans with Kashin-Beck Disease (FSAT-KBD) and radiographic outcomes.

Results

The patients underwent a follow-up, and the mean follow-up time was 3.8 years. VAS scores significantly decreased within the first 6 months postoperatively. This decrease continued until the final follow-up (p < 0.01). This result was supported by a significant increase in the Harris and FSAT-KBD scores after the surgery (p < 0.01). At the final follow-up, there was no change in prosthesis positioning or radiographic evidence of prosthesis loosening. One case received impacted allograft bone croutons and had worn polyethylene components replaced after 6 years because the patient suffered severe pelvic and femoral osteolytic lesions postoperatively.

Conclusions

Hip replacement can relieve pain and improve joint function in treating severe KBD hip. Additional studies that are more extensive are needed to confirm the findings of our study.

Elevation of IGFBP2 contributes to mycotoxin T-2-induced chondrocyte injury and metabolism

Kashin-Beck disease (KBD) is an endemic degenerative osteoarthropathy. The mycotoxin of T-2 toxin is extensively accepted as a major etiological contributor to KBD. However, its function and mechanism in KBD remains unclearly elucidated. Here, T-2 toxin treatment induced chondrocyte injury in a time- and dose-dependent manner by repressing cell viability and promoting cell necrosis and apoptosis. Importantly, T-2 suppressed the transcription of type II collagen and aggrecan, as well as the release of sulphated glycosaminoglycan (sGAG). Furthermore, exposure to T-2 enhanced the transcription of matrix metalloproteinases (MMPs), including MMP-1, -2, -3 and -9. In contrast to control groups, higher expression of insulin-like growth factor binding protein 2 (IGFBP2) was observed in chondrocytes from KBD patients. Interestingly, T-2 toxin caused a dramatical elevation of IGFBP2 expression in chondrocytes. Mechanism analysis corroborated that cessation of IGFBP2 expression alleviated T-2-induced damage to chondrocytes. Simultaneously, transfection with IGFBP2 siRNA also attenuated matrix synthesis and catabolism-related gene expressions of MMPs. Together, this study validated that T-2 toxin exposure might promote the progression of KBD by inducing chondrocyte injury, suppressing matrix synthesis and accelerating cellular catabolism through IGFBP2. Therefore, this research will elucidate a new insight about how T-2 toxin participate in the pathogenesis of KBD.

Alternaria in Food: Ecophysiology, Mycotoxin Production and Toxicology

Alternaria species are common saprophytes or pathogens of a wide range of plants pre- and post-harvest. This review considers the relative importance of Alternaria species, their ecology, competitiveness, production of mycotoxins and the prevalence of the predominant mycotoxins in different food products. The available toxicity data on these toxins and the potential future impacts of Alternaria species and their toxicity in food products pre- and post-harvest are discussed. The growth of Alternaria species is influenced by interacting abiotic factors, especially water activity (aw), temperature and pH. The boundary conditions which allow growth and toxin production have been identified in relation to different matrices including cereal grain, sorghum, cottonseed, tomato, and soya beans. The competitiveness of Alternaria species is related to their water stress tolerance, hydrolytic enzyme production and ability to produce mycotoxins. The relationship between A. tenuissima and other phyllosphere fungi has been examined and the relative competitiveness determined using both an Index of Dominance (ID) and the Niche Overlap Index (NOI) based on carbon-utilisation patterns. The toxicology of some of the Alternaria mycotoxins have been studied; however, some data are still lacking. The isolation of Alternaria toxins in different food products including processed products is reviewed. The future implications of Alternaria colonization/infection and the role of their mycotoxins in food production chains pre- and post-harvest are discussed.

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

Objective

There were no studies on the macrophage colony-stimulating factor (M-CSF), receptor activator of NF-kappaB ligand (RANKL) and osteoprotegerin (OPG) in the pathogenesis of Kashin-Beck disease (KBD). The objective of the present study was to investigate the serum M-CSF, RANKL and OPG in rats fed with KBD-affected diet.

Methods

Ninety Wistar rats were divided into five groups. The rats received standard commercial feed with or without T-2 toxin additive, low protein feed with or without or T-2 toxin additive and the KBD-affected feed. The serum bioactivity of M-CSF, RANKL and OPG was tested by enzyme-linked immunosorbent assay.

Results

The serum levels of M-CSF in E group rats were higher than those in the other groups in the five groups (P < 0.01). The serum levels of RANKL and OPG in E group rats were highest in the five groups and have significant difference compared to the other groups (P < 0.05).

Conclusions

The molecule of M-CSF, RANKL and OPG may be involved in the regulation of epiphyseal plate injury and repair in KBD, and its participation in the pathogenesis of KBD should be studied in the future.

Magnetic resonance imaging in the tibial epiphyseal growth plate development of Wistar rat

OBJECTIVE

This research aims to investigate magnetic resonance imaging (MRI) in the tibial epiphyseal growth plate development of Wistar rat.

METHODS

Fifty weanling Wistar rats were divided by a computerized blocking procedure into five groups. The rats received standard commercial feed with or without T-2 toxin additive, low-protein feed with or without T-2 toxin additive, and Kashin-Beck disease (KBD)-affected feed.

RESULTS

Compared with the control group rat, MRI showed localized epiphyseal plate swelling, rough appearance, and uneven signal on the tibia of rats fed with KBD-affected feed. Histology confirmed the epiphyseal plate degeneration seen by MRI, and the degenerative changes were characterized by abnormal distribution of chondrocytes with loss and clustering, cartilage fragmentation, and erosion in group E.

CONCLUSIONS

The MR image of the rat epiphyseal plate is altered in the KBD model rats, and epiphyseal plate MRI appearance has been reproduced by using T-2 toxin and KBD-affected feed of epidemic district.

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.

Clinical features of Kashin-Beck disease in adults younger than 50 years of age during a low incidence period: severe elbow and knee lesions

More than one million people are affected by Kashin-Beck disease (KBD) in a limited endemic area. However, few studies focused on the clinical features of adult KBD patients. The aim of this study was to investigate the clinical features of adult KBD patients who were younger than 50 years of age during a low incidence period. A special questionnaire was designed that surveyed general data, clinical symptoms, and signs and included the Visual Analogue Scale (VAS). Anthropometrics, the joint VAS, the range of joint motion (ROM), and joint function were measured. The VAS and joint dysfunction were compared among the different joints of extremities, and the relationship among the VAS, ROM, age, course of KBD, and number of enlarged knee and elbow joints elbow was analyzed. Two hundred forty-nine adult Tibetan KBD patients, matched with 249 healthy control subjects, have been surveyed. The VAS results show that the knee is the joint associated with the most pain, followed by the elbow. The elbow shows a higher percentage of limited ROM (47.0 %). The number of enlarged joints has a significant correlation with the VAS or elbow and knee ROM compared with the age or course of disease (P < 0.05). Severe elbow and knee lesions are important clinical features of KBD in adults younger than 50 years of age during a low incidence period. The number of enlarged joints can partially predict the VAS or ROM of elbow and knee and may be used for evaluating the patient's condition and function.

Efficacy of celecoxib, meloxicam and paracetamol in elderly Kashin-Beck disease (KBD) patients

The objective of this study was to compare the efficacy and tolerability of celecoxib, meloxicam and paracetamol in late Kashin-Beck disease. Adults (n = 168) with Kashin-Beck disease were randomised in clusters to receive six week courses of celecoxib 200 mg once daily, meloxicam 7.5 mg once daily or paracetamol 300 mg three times daily. Efficacy assessments included overall joint pain intensity and Western Ontario and McMaster Universities Osteoarthritis Index subscales; tolerability was evaluated by adverse event and physician reporting. Celecoxib and meloxicam were efficacious in relieving pain and improving stiffness, but unable to improve physical function after six weeks. Paracetamol was efficacious in relieving pain, but unable to improve morning stiffness and physical function after six weeks. Celecoxib and meloxicam provide predictable and sustained relief from pain and stiffness. Paracetamol can relieve the pain. None of the treatments improved impaired physical function in Kashin-Beck disease.

Study on the effect of T-2 toxin combined with low nutrition diet on rat epiphyseal plate growth and development

The purpose of this study was to observe early lesions of rat epiphyseal plates and metaphysis caused by T-2 toxin and T-2 toxin combined with a low nutrition diet to determine possible pathogenic factors of Kashin-Beck disease (KBD). Ninety Wistar rats were divided into three groups. Group A was fed with a normal diet as control; group B was fed with a normal diet and T-2 toxin; and group C was fed with a low nutrition diet and T-2 toxin. The left knee specimens were collected, fixed in formaldehyde solution, stained by hematoxylin and eosin and Masson. After two weeks, the epiphyseal plate showed necrosis of chondrocytes in groups B and C. After four weeks, more obvious chondrocyte necrosis appeared. The positive rate of Lamellar necrosis in group C was significantly higher than that in groups B and A (P < 0.01). Metaphyseal trabecular bone showed sparse disorder and disruption in group C. T-2 toxin combined with a low nutrition diet could lead to more serious chondrocyte necrosis in the epiphyseal plate and disturb metaphyseal trabecular bone formation.

Effects of physical environment on the evolution of Kashin-Beck disease in Tibet

In previous studies we observed a proximo-distal gradient of lesion frequencies along the limb, with the distal joints being the most often affected. This suggests an associated effect of environmental factors on the most exposed joints. On a population of 820 children (mean age 13 years) of endemic areas distributed in groups of healthy and severity stages I to III of KBD (Kashin-Beck disease), the effects of different working activities were studied. Heavy work like that of a ploughman were compared to light physical work, e.g. school children, and exposure to cold and history of frostbite were also considered. The most severe stages, II and III, were present in 72% of the ploughman vs. 29% of the schoolchildren, 70% of the shepherds vs. 30% (p < 0.001) of the schoolchildren, and in 65% of the shepherds working in winter vs. 40% of those working in the other seasons (p < 0.001). In the group with history of frostbite, 58% present the severest stages vs. 40% without (p < 0.001). The results confirm a highly significant relation between microtrauma and cold and the severity of the KBD alterations.

Osteoarthritis

Osteoarthritis (OA) is a chronic degenerative disorder characterized by cartilage loss. Its prevalence is high, and it is a major cause of disability. The cause of OA is not known; however, current evidence indicates that it is multifactorial. Major risk factors for osteoarthritis are age, female sex, obesity, geographic factors, occupational knee-bending, physical labour, genetic factors and race, joint trauma, vitamin D deficiency, and chondrocalcinosis. Osteoarthritis causes joint pain, stiffness, and limitation of joint function. Knee involvement is the commonest presentation of this disease all over the world. Given the absence of a curative treatment, it is important to treat osteoarthritis as effectively as possible using a multidisciplinary approach tailored to the patient's needs. This article reviews current thinking on the epidemiology, clinical presentation, lifestyle, genetic epidemiology, and management of osteoarthritis in developing countries.

The oxidative damage of butenolide to isolated erythrocyte membranes

Butenolide (CAS No. 16275-44-8), a mycotoxin produced by several Fusarium species, has been shown to be a potential risk factor for animal and human health. This study was undertaken to investigate the potential oxidative damage of butenolide to biomembranes in vitro using the erythrocyte membrane model. Following exposure of isolated rat erythrocyte membranes to butenolide, the extent of oxidative damage was assessed by measuring lipid peroxidation, -SH groups content, Ca2+/Mg2+-ATPase and Na+/K+-ATPase activities, and conformational changes in membrane proteins. It was observed that butenolide resulted in a significant lipid peroxidation, revealed by a concentration-dependent increase in the level of thiobarbituric acid reactive substances (TBARS). Similarly, this toxin induced a concentration-dependent decrease in the content of membrane total -SH groups, as well as free -SH groups. Membrane-bound enzymes were also impaired by the toxin, demonstrated by the marked inhibition of the activities of Na+/K+-ATPase and Ca2+/Mg2+-ATPase. Conformational changes in membrane proteins were determined using electron paramagnetic resonance (EPR) spin labeling. Butenolide caused an increase in the ratio of weakly to strongly immobilized components (W/S ratio) in a manner of concentration-dependent, indicating conformational changes in membrane proteins occurred. In conclusion, these findings indicate that butenolide is capable of inducing significant oxidative damage to membrane lipids and proteins.

Depletion of intracellular glutathione mediates butenolide-induced cytotoxicity in HepG2 cells

Butenolide, 4-acetamido-4-hydroxy-2-butenoic acid gamma-lactone is one of the mycotoxins produced by Fusarium species which are often found on cereal grains and animal feeds throughout the world. It has been implicated as the etiology of some diseases both in animals and in humans. Though butenolide represents a potential threat to animal and human heath, there are few studies on its toxicity so far, especially on the toxic mechanisms. In this study, we investigated the cytotoxicity of butenolide on HepG2 cells and its possible mechanism from the viewpoint of oxidative stress. Butenolide reduced cell viability in a concentration- and time-dependent manner. A rapid depletion of intracellular glutathione (GSH) was observed after exposure cells to butenolide, concomitantly an increase in intracellular reactive oxygen species (ROS) production prior to cell death, indicating that oxidative stress was involved in butenolide cytotoxicity. To elucidate the role of GSH in the cytotoxicity of butenolide, intracellular GSH content was modulated before exposure to butenolide. l-buthionine-[S,R]-sulfoximine (BSO), a well-known inhibitor of GSH synthesis, aggravated butenolide-induced GSH depletion, ROS production and the loss in cell viability; in contrast, GSH depletion and ROS production was strongly inhibited, and the loss in cell viability was completely abrogated by thiol-containing compounds GSH, N-acetylcysteine (NAC) and dithiothreitol (DTT). Furthermore, a ROS scavenger catalase obviously abated ROS production and cytotoxicity induced by butenolide. Together, these results clearly demonstrate that oxidative stress plays an important role in butenolide cytotoxicity, and intracellular GSH depletion may be an original trigger of the onset of butenolide cytotoxicity.