The effects of T-2 toxin on the prevalence and development of Kashin-Beck disease in China: a meta-analysis and systematic review

Potential involvement of connective tissue growth factor in chondrocytes apoptosis of Kashin-Beck disease

BACKGROUND

Kashin-Beck disease (KBD) is an endemic osteoarthropathy characterized by excessive chondrocytes apoptosis. T-2 toxin exposure has been proved to be its etiology. Connective tissue growth factor (CTGF) exerts a profound influence on cartilage growth and metabolism. We investigated the potential role of CTGF in KBD development and examined CTGF alterations under T-2 toxin stimulation.

METHODS

The levels of CTGF and chondrocyte apoptosis-related markers in cartilage and primary chondrocytes from KBD and control groups were measured using qRT-PCR, Western blotting, immunohistochemistry, and immunofluorescence. We analyzed expression changes of these genes in response to T-2 toxin. Apoptosis rates of chondrocytes induced by T-2 toxin were measured by flow cytometry and TUNEL assay. The active pharmaceutical ingredient targeting CTGF was screened through Comparative Toxicogenomics Database, and molecular docking was performed using AutoDock Tools.

RESULTS

The CTGF levels in KBD cartilage and chondrocytes were significantly elevated and positively associated with the levels of apoptosis-related genes. T-2 toxin exposure increased CTGF and apoptosis-related gene levels in chondrocytes, with apoptosis rates rising alongside T-2 toxin concentration. Curcumin was identified as targeting CTGF and exhibited effective binding. It could down-regulate CTGF, apoptosis-related genes, such as Cleaved caspase 3 and BAX, and also significantly reduce apoptosis rate in chondrocytes treated with T-2 toxin.

CONCLUSION

CTGF plays a crucial role in the development of KBD. Curcumin has shown potential in inhibiting CTGF levels and reducing chondrocyte apoptosis, highlighting its promise as a therapeutic agent for preventing cartilage damage in KBD. Our findings provided valuable insights into the pathogenesis of KBD and could promote the development of novel therapeutic strategies for this debilitating disease.

Hesperetin Attenuates T-2 Toxin-Induced Chondrocyte Injury by Inhibiting the p38 MAPK Signaling Pathway

BACKGROUND

Hesperetin, a flavonoid derived from citrus fruits, exhibits potent antioxidant and anti-inflammatory activities and has been implicated in cartilage protection. However, its effectiveness against T-2 toxin-induced knee cartilage damage remains unclear.

METHODS

In this study, high-throughput sequencing analysis was employed to identify the key signaling pathways involved in T-2 toxin-induced articular cartilage damage in rats. Animal models were divided into the following groups: control, low-dose T-2 toxin, high-dose T-2 toxin, T-2 toxin + hesperetin, hesperetin, and vehicle. Pathological staining and immunohistochemistry were used to assess pathological changes, as well as the expression levels of the cartilage matrix-related proteins MMP13 and collagen II, along with the activation of the p38 MAPK signaling pathway. Additionally, primary rat chondrocytes were cultured to establish an in vitro model for investigating the underlying mechanism.

RESULTS

High-throughput sequencing analysis revealed the involvement of the MAPK signaling pathway in T-2 toxin-induced articular cartilage damage in rats. Hesperetin intervention in T-2 toxin-exposed rats attenuated pathological cartilage damage. Immunohistochemistry results demonstrated a significant reduction in collagen II protein expression in the high-dose T-2 toxin group (p < 0.01), accompanied by a significant increase in MMP13 protein expression (p < 0.01). In both the articular cartilage and the epiphyseal plate, the T-2 toxin + hesperetin group exhibited significantly higher collagen II protein expression than the high-dose T-2 toxin group (p < 0.05), along with significantly lower MMP13 protein expression (p < 0.05). Hesperetin inhibited the over-activation of the p38/MEF2C signaling axis induced by T-2 toxin in primary rat chondrocytes. Compared to the T-2 toxin group, the T-2 toxin + hesperetin group showed significantly reduced phosphorylation levels of p38 and protein expression levels of MEF2C (p < 0.001 or p < 0.05). Moreover, the T-2 toxin + hesperetin group exhibited a significant decrease in MMP13 protein expression (p < 0.05) and a significant increase in collagen II protein expression (p < 0.01) compared to the T-2 toxin group.

CONCLUSIONS

T-2 toxin activates the p38 MAPK signaling pathway, causing knee cartilage damage in rats. Treatment with hesperetin inhibits the p38/MEF2C signaling axis, regulates collagen II and MMP13 protein expression, and reduces cartilage injury significantly.

Modulation of Ras signaling pathway by exosome miRNAs in T-2 toxin-induced chondrocyte injury

This study aims to investigate the impact of T-2 toxin on the regulation of downstream target genes and signaling pathways through exosome-released miRNA in the development of cartilage damage in Kashin-Beck disease (KBD). Serum samples from KBD patients and supernatant from C28/I2 cells treated with T-2 toxin were collected for the purpose of comparing the differential expression of exosomal miRNA using absolute quantitative miRNA-seq. Target genes of differential exosomal miRNAs were identified using Targetscan and Miranda databases, followed by GO and KEGG enrichment analyses. Validation of key indicators of chondrocyte injury in KBD was conducted using Real-time quantitative PCR (RT-qPCR) and Immunohistochemical staining (IHC). A total of 20 exosomal miRNAs related to KBD were identified in serum, and 13 in chondrocytes (C28/I2). The identified exosomal miRNAs targeted 48,459 and 60,612 genes, primarily enriched in cell organelles and membranes, cell differentiation, and cytoskeleton in the serum, and the cytoplasm and nucleus, metal ion binding in chondrocyte (C28/I2). The results of the KEGG enrichment analysis indicated that the Ras signaling pathway may play a crucial role in the pathogenesis of KBD. Specifically, the upregulation of hsa-miR-181a-5p and hsa-miR-21-3p, along with the downregulation of hsa-miR-152-3p and hsa-miR-186-5p, were observed. Additionally, T-2 toxin intervention led to a significant downregulation of RALA, REL, and MAPK10 expression. Furthermore, the protein levels of RALA, REL, and MAPK10 were notably decreased in the superficial and middle layers of cartilage tissues from KBD. The induction of differential expression of chondrocyte exosomal miRNAs by T-2 toxin results in the collective regulation of target genes RALA, REL, and MAPK10, ultimately mediating the Ras signaling pathway and causing a disruption in chondrocyte extracellular matrix metabolism, leading to chondrocyte injury.

T-2 toxin-induced damage to articular cartilage in rats coincided with impaired autophagy linked to the HIF-1α/AMPK signaling axis

T-2 toxin is one of the most toxic mycotoxins. People are primarily exposed to T-2 toxin through the consumption of spoiled food, typically over extended periods and at low doses. T-2 toxin can cause damage to articular cartilage. However, the exact mechanism is not fully understood. In this experiment, 36 male rats were divided into a control group, a solvent control group, and a T-2 toxin group. The rats in the T-2 toxin group were orally administered the toxin at a dosage of 100 ng/g BW/Day. The damage to articular cartilage and key proteins associated with the autophagy process and the HIF-1α/AMPK signaling axis was assessed at 4, 8, 12, and 16 weeks. Our findings indicate that T-2 toxin-induced damage to articular cartilage in rats coincided with impaired autophagy linked to the HIF-1α/AMPK signaling pathway. This study offers novel insights into the precise mechanism underlying T-2 toxin-induced damage to articular cartilage.

Prevalence of T-2 Toxin in the Food and Beverages of Residents Living in a Kashin-Beck-Disease Area of Qamdo, Tibet

It has been strongly suggested that selenium deficiency and T-2 toxin contamination have a strong relationship with the occurrence and development of Kashin-Beck disease (KBD). In order to provide information for understanding the high prevalence of KBD in Tibet, this study collected the responses to a cubital venous blood and dietary questionnaire of 125 subjects including 75 KBD patients and 50 healthy controls in a KBD-prevalent county (Luolong County) in Tibet, China. A total of 10 household local families were randomly selected in this area, and local diet samples of brick tea, Zanba powder, milk residue, and hulless Barley were collected from these residents. Selenium content in blood was detected by inductively coupled plasma mass spectrometry (ICP-MS). The T-2 toxin contamination level in food sample was assayed using an ELISA kit. The selenium levels of patients and controls were 42.0 ± 19.8 and 56.06 ± 22.4 μg/L, respectively. The serum selenium level in controls was higher than that in patients, but there was no significant difference, and the serum selenium level both in patients and controls in Tibet was lower than the normal range. The results of the dietary survey showed that the number of respondents who consumed butter tea was large; 46.67% of patients indicated that they drank buttered tea every day, which was significantly higher than in controls. The contents of T-2 toxin in Zanba powder, milk residue, hulless barley and drinking water samples were below the detection limit (0.05 μg/kg); this result was labeled Tr. Unexpectedly, the contents of T-2 toxin in brick tea were higher, with average levels of 424 ± 56 μg/kg in Detong village and 396 ± 24 μg/kg in Langcuo village. For the first time, we report the presence of an extremely high concentration of T-2 toxin in brick tea of Tibet.

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.

T-2 toxin induces mitochondrial dysfunction in chondrocytes via the p53-cyclophilin D pathway

Kashin-Beck disease is an endemic joint disease characterized by deep chondrocyte necrosis, and T-2 toxin exposure has been confirmed its etiology. This study investigated mechanism of T-2 toxin inducing mitochondrial dysfunction of chondrocytes through p53-cyclophilin D (CypD) pathway. The p53 signaling pathway was significantly enriched in T-2 toxin response genes from GeneCards. We demonstrated the upregulation of the p53 protein and p53-CypD complex in rat articular cartilage and ATDC5 cells induced by T-2 toxin. Transmission electron microscopy showed the damaged mitochondrial structure of ATDC5 cells induced by T-2 toxin. Furthermore, it can lead to overopening of the mitochondrial permeability transition pore (mPTP), decreased mitochondrial membrane potential, and increased reactive oxygen species generation in ATDC5 cells. Pifithrin-α, the p53 inhibitor, alleviated the increased p53-CypD complex and mitochondrial dysfunction of chondrocytes induced by T-2 toxin, suggesting that p53 played an important role in T-2 toxin-induced mitochondrial dysfunction. Mechanistically, T-2 toxin can activate the p53 protein, which can be transferred to the mitochondrial membrane and form a complex with CypD. The increased binding of p53 and CypD mediated the excessive opening of mPTP, changed mitochondrial membrane permeability, and ultimately induced mitochondrial dysfunction and apoptosis of chondrocytes.

Synergistic effects of T-2 toxin and selenium deficiency exacerbate renal fibrosis through modulation of the ERα/PI3K/Akt signaling pathway

As common pathogenic agents in the world and widely distributed globally, T-2 toxin and selenium deficiency might exacerbate toxic effects by combined exposure, posing a dramatic health hazard to humans and animals. In this study, we aim to elucidate the underlying mechanisms of renal fibrosis triggered by T-2 toxin and selenium deficiency exposure. A total of thirty-two rats are randomly divided into the normal control, T-2 toxin, selenium deficiency, and combined intervention groups. T-2 toxin (100 ng/g) is intragastric gavaged to the rats in compliance with the body weight. Both the standard (containing selenium 0.20 mg/Kg) and selenium-deficient (containing selenium 0.02 mg/Kg) diets were manufactured adhering to the AIN-93 formula. After 12 weeks of intervention, renal tissue ultrastructural and pathological changes, inflammatory infiltration, epithelial mesenchymal transition (EMT), and extracellular matrix (ECM) deposition are evaluated, respectively. Metabolomics analysis is conducted to explore the underlying pathology of renal fibrosis, followed by the validation of potential mechanisms at gene and protein levels. T-2 toxin and selenium deficiency exposure results in podocyte foot process elongation or fusion, tubular vacuolization and dilatation, and collagen deposition in the kidneys. Additionally, it also increases inflammatory infiltration, EMT conversion, and ECM deposition. Metabolomics analysis suggests that T-2 toxin and selenium deficiency influence amino acid and cholesterol metabolism, respectively, and the estrogen signaling pathway is probably engaged in renal fibrosis progression. Moreover, T-2 toxin and selenium deficiency are found to regulate the expressions of the ERα/PI3K/Akt signaling pathway. In conclusion, T-2 toxin and selenium deficiency synergistically exacerbate renal fibrosis through regulating the ERα/PI3K/Akt signaling pathway, and inflammatory infiltration, EMT and ECM deposition are involved in this process.

WISP1 Is Involved in the Pathogenesis of Kashin-Beck Disease via the Autophagy Pathway

OBJECTIVE

Kashin-Beck disease (KBD) is a kind of endemic and chronic osteochondropathy in China. This study aims to explore the functional relevance and potential mechanism of Wnt-inducible signaling pathway protein 1 (WISP1) in the pathogenesis of KBD.

DESIGN

KBD and control cartilage specimens were collected for tissue section observation and primary chondrocyte culture. Firstly, the morphological and histopathological observations were made under a light and electron microscope. Then, the expression levels of WISP1 as well as molecular markers related to the autophagy pathway and extracellular matrix (ECM) synthesis were detected in KBD and control chondrocytes by qRT-PCR, Western blot, and immunohistochemistry. Furthermore, the lentiviral transfection technique was applied to make a WISP1 knockdown cell model based on KBD chondrocytes. In vitro intervention experiments were conducted on the C28/I2 human chondrocyte cell line using human recombinant WISP1 (rWISP1).

RESULTS

The results showed that the autolysosome appeared in the KBD chondrocytes. The expression of WISP1 was significantly higher in KBD chondrocytes. Additionally, T-2 toxin, a risk factor for KBD onset, could up-regulate the expression of WISP1 in C28/I2. The autophagy markers ATG4C and LC3II were upregulated after the low-concentration treatment of T-2 toxin and downregulated after the high-concentration treatment. After knocking down WISP1 expression in KBD chondrocytes, MAP1LC3B decreased while ATG4C and COL2A1 increased. Moreover, the rWISP1 protein treatment in C28/I2 chondrocytes could upregulate the expression of ATG4C and LC3II at the beginning and downregulate them then.

CONCLUSIONS

Our study suggested that WISP1 might play a role in the pathogenesis of KBD through autophagy.

A universal CRISPR-Cas14a responsive triple-sensitized upconversion photoelectrochemical sensor

It has recently been discovered that, like other members of the Cas family (12a and 13a), the clustered regularly interspaced short palindrome repeat CRISPR-Cas14a system not only mediates high-sensitivity detection with exceptionally strong gene editing ability but is also generally useful for DNA detection via fluorescence. Photoelectrochemical (PEC) sensors have been widely applied as efficient analytical tools. Measuring electrical signals is more cost-effective and the necessary equipment is more easily portable than fluorescence signal detectors, but their stability still needs to be improved. The high base resolution of CRISPR-Cas14a can compensate for such shortcomings. Therefore, electrical signals and fluorescence signals were combined, and the development of a universal CRISPR-Cas14a-responsive ultrasensitive upconversion PEC sensor is described in this paper. Moreover, strand displacement amplification (SDA) and a near-infrared (NIR) light source were utilized to further improve the stability and sensitivity of the photoelectric signals. At the same time, the modified working electrode (UCNPs-ssDNA-CdS@Au/ITO) on the three-electrode disposable sensor was used as the reporter probe, which cooperates with the trans-cleavage activity of Cas14a endonuclease. To verify the universality of this sensor, the UCNPs-Cas14a-based PEC sensor was applied for the detection of the small-molecule toxin T2 and protein kinase PTK7. Here, we report that the limit of detection of this reagent was within the fg range, successfully applied to the detection of T2 in oats and PTK7 in human serum. We propose that by combining PEC and CRISPR-14a, UCNPs-Cas14a-based PEC sensors could become powerful drivers for the extensive development of ultrasensitive, accurate and cost-effective universal sensors for detection and diagnosis.

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.

Selenomethionine Antagonized microRNAs Involved in Apoptosis of Rat Articular Cartilage Induced by T-2 Toxin

T-2 toxin and selenium deficiency are considered important etiologies of Kashin-Beck disease (KBD), although the exact mechanism is still unclear. To identify differentially expressed microRNAs (DE-miRNAs) in the articular cartilage of rats exposed to T-2 toxin and selenomethionine (SeMet) supplementation, thirty-six 4-week-old Sprague Dawley rats were divided into a control group (gavaged with 4% anhydrous ethanol), a T-2 group (gavaged with 100 ng/g·bw/day T-2 toxin), and a T-2 + SeMet group (gavaged with 100 ng/g·bw/day T-2 toxin and 0.5 mg/kg·bw/day SeMet), respectively. Toluidine blue staining was performed to detect the pathological changes of articular cartilage. Three rats per group were randomly selected for high-throughput sequencing of articular cartilage. Target genes of DE-miRNAs were predicted using miRanda and RNAhybrid databases, and the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway were enriched. The network map of miRNA-target genes was constructed using Cytoscape software. The expression profiles of miRNAs associated with KBD were obtained from the Gene Expression Omnibus database. Additionally, the DE-miRNAs were selected for real-time quantitative PCR (RT-qPCR) verification. Toluidine blue staining demonstrated that T-2 toxin damaged articular cartilage and SeMet effectively alleviated articular cartilage lesions. A total of 50 DE-miRNAs (28 upregulated and 22 downregulated) in the T-2 group vs. the control group, 18 DE-miRNAs (6 upregulated and 12 downregulated) in the T-2 + SeMet group vs. the control group, and 25 DE-miRNAs (5 upregulated and 20 downregulated) in the T-2 + SeMet group vs. the T-2 group were identified. Enrichment analysis showed the target genes of DE-miRNAs were associated with apoptosis, and in the MAPK and TGF-β signaling pathways in the T-2 group vs. the control group. However, the pathway of apoptosis was not significant in the T-2 + SeMet group vs. the control group. These results indicated that T-2 toxin induced apoptosis, whereas SeMet supplementation antagonized apoptosis. Apoptosis and autophagy occurred simultaneously in the T-2 + SeMet group vs. T-2 group, and autophagy may inhibit apoptosis to protect cartilage. Compared with the GSE186593 dataset, the evidence of miR-133a-3p involved in apoptosis was more abundant. The results of RT-qPCR validation were consistent with RNA sequencing results. Our findings suggested that apoptosis was involved in articular cartilage lesions induced by T-2 toxin, whereas SeMet supplementation antagonized apoptosis, and that miR-133a-3p most probably played a central role in the apoptosis process.

T-2 and HT-2 Toxins: Toxicity, Occurrence and Analysis: A Review

One of the major classes of mycotoxins posing serious hazards to humans and animals and potentially causing severe economic impact to the cereal industry are the trichothecenes, produced by many fungal genera. As such, indicative limits for the sum of T-2 and HT-2 were introduced in the European Union in 2013 and discussions are ongoing as to the establishment of maximum levels. This review provides a concise assessment of the existing understanding concerning the toxicological effects of T-2 and HT-2 in humans and animals, their biosynthetic pathways, occurrence, impact of climate change on their production and an evaluation of the analytical methods applied to their detection. This study highlights that the ecology of F. sporotrichioides and F. langsethiae as well as the influence of interacting environmental factors on their growth and activation of biosynthetic genes are still not fully understood. Predictive models of Fusarium growth and subsequent mycotoxin production would be beneficial in predicting the risk of contamination and thus aid early mitigation. With the likelihood of regulatory maximum limits being introduced, increased surveillance using rapid, on-site tests in addition to confirmatory methods will be required. allowing the industry to be proactive rather than reactive.

Spectroscopic and Microestructural Evidence for T-2 Toxin Adsorption Mechanism by Natural Bentonite Modified with Organic Cations

Aluminosilicates are adsorbents able to bind mycotoxins, and their chemical modification increases their affinity to adsorb low-polarity mycotoxins. To further investigate if the inclusion of salts in bentonite modifies its adsorptive capacity, we studied T-2 toxin adsorption in natural bentonite (NB) and when modified with quaternary ammonium salts differing in polarity and chain length: myristyl trimethyl ammonium bromide (B14), cetyl trimethyl ammonium bromide (B16) and benzyl dimethyl stearyl ammonium chloride (B18). The results showed that quaternary salts made bentonite: displace monovalent (Na+1, K+1) and divalent (Mg+2, Ca+2) ions; reduce its porosity; change its compaction and structure, becoming more crystalline and ordered; and modify the charge balance of sheets. T-2 adsorption was higher in all modified materials compared to NB (p ≤ 0.0001), and B16 (42.96%) better adsorbed T-2 compared to B18 (35.80%; p = 0.0066). B14 (38.40%) showed no differences compared to B16 and B18 (p > 0.05). We described the T-2 adsorption mechanism in B16, in which hydrogen bond interactions, Van der Waals forces and the replacement of the salt by T-2 were found. Our results showed that interaction types due to the inclusion in B16 might be more important than the hydrocarbon chain length to improve the adsorptive capacity of bentonite.

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.

MiR-214-3p may alleviate T-2 toxin-induced chondrocyte apoptosis and matrix degradation by regulating NF-κB signaling pathway in vitro

T-2 toxin is part of the most toxic fungal secondary metabolites contaminating different kinds of grains. Previous studies have demonstrated that T-2 toxin can influence the survival of chondrocytes and extracellular matrix (ECM) composition. MiR-214-3p is essential for the homeostasis of chondrocytes and ECM. However, the molecular machinery underlying T-2 toxin-induced chondrocyte apoptosis and ECM degradation remain to be elucidated. The present study aimed to investigate the mechanism of miR-214-3p's involvement in T-2 toxin-induced chondrocyte apoptosis and ECM degradation. Meanwhile, the role of the NF-κB signaling pathway was scrutinized. C28/I2 chondrocytes were treated with 8 ng/ml of T-2 toxin for 24 h, after the pretreatment of miR-214-3p interfering RNAs for 6 h. Gene and protein levels involved in chondrocyte apoptosis and ECM degradation were assessed through RT-PCR and Western blotting. The apoptosis rate of chondrocyte was measured by flow cytometry. Results and data indicated that miR-214-3p was decreased in a dose-dependent manner at different concentrations of T-2 toxin. The enhancement of miR-214-3p could alleviate chondrocyte apoptosis and ECM degradation due to T-2 toxin exposure. The upregulation of miR-214-3p was associated with the decreased expression of apoptosis-promoting genes such as Bax and Cleaved-caspase3/caspase3 as well as the increased expression of anti-apoptotic genes such as Bcl2 and Survivin. Furthermore, miR-214-3p stimulated the relative protein expression of collagen Ⅱ but inhibited the expression of MMP13. Overexpressing miR-214-3p could suppress the relative protein expression of IKKβ and phospho-p65/p65, thus blocking the activation of the NF-κB signaling pathway. The study suggested that the miR-214-3p attenuates T-2 toxin-induced chondrocyte apoptosis and ECM degradation through a potential NF-κB signaling pathway.

Selenium Improves Bone Microenvironment-Related Hematopoiesis and Immunity in T-2 Toxin-Exposed Mice

The T-2 toxin is one of the most frequent contaminants in the environment and agricultural production globally. It exerts a wide range of toxic effects. Selenium (Se), as an antioxidant, has the potential to be widely used to antagonize mycotoxin toxicity. To investigate the protective effects of Se on bone microenvironment (BM)-related hematopoiesis and immunity after T-2 toxin exposure, 36 male mice were treated with the T-2 toxin (1 mg/kg) and/or Se (0.2 mg/kg) by intragastric administration for 28 days. The results showed that Se alleviated T-2 toxin-induced cytopenia and splenic extramedullary hematopoiesis. Se also significantly relieved T-2 toxin-induced immunosuppression, as assessed by immune factors and lymphocytes. Furthermore, Se also attenuated oxidative stress and apoptosis and improved the BM in T-2 toxin-exposed mice. Therefore, Se improves BM-related hematopoiesis and immunity after T-2 toxin exposure. This study provides references for identifying the toxic mechanism and screening potential therapeutic drugs of the T-2 toxin.

MiR-140 is involved in T-2 toxin-induced matrix degradation of articular cartilage

T-2 toxin is one of the most toxic mycotoxins contaminating various grains. It is considered an environmental risk factor for Kashin-Beck disease (KBD), an endemic degenerative osteochondrosis. Currently, the underlying molecular mechanisms of articular cartilage damage caused by T-2 toxin have not been elucidated. Studies have shown that miR-140 is essential for cartilage formation, and extracellular matrix (EMC) synthesis and degradation. The objective of this study was to investigate the mechanism of miR-140 involvement in T-2 toxin-induced articular cartilage damage. Two treatment groups, each containing wild-type mice and miR-140 knockout mice were administered with T-2 toxin (200 ng/g BW/day) or a normal diet for 1 month, 3 months, and 6 months. Results showed that T-2 toxin caused articular cartilage and growth plate damage in mice. The expression of miR-140 decreased in articular cartilage of wild-type mice treated with T-2 toxin, and miR-140 deficiency aggravated T-2 toxin-induced knee cartilage damage. T-2 toxin-caused the reduction of miR-140 expression was consistent with collagen type II (COL2A1), aggrecan (ACAN), and SRY-box containing gene 9 (SOX9) and opposite to matrix metalloproteinase 13 (MMP13), a disintegrin and metalloproteinase with thrombospondin motif 5 (ADAMTS-5), and v-ral simian leukemia viral oncogene homolog A (RALA). In addition, we collected finger joints cartilage and knee joints cartilage from KBD patients and controls for paraffin embedding and sectioning. Results found that the expression of miR-140 in the articular cartilage of the KBD group was lower than that of the control group. The expression of COL2A1, ACAN, and SOX9 decreased, whereas ADAMTS-5, MMP13, and RALA increased in the articular cartilage of the KBD group. These results revealed that miR-140 might be involved in T-2 toxin-induced degradation of the ECM of articular cartilage. Moreover, the occurrence of KBD might be related to the decreased expression of miR-140 in articular cartilage.

Effects of T-2 toxin on growth performance, feather quality, tibia development and blood parameters in Yangzhou goslings

T-2 toxin is a dangerous natural pollutant and widely exists in animal feed, often causing toxic damage to poultry, such as slow growth and development, immunosuppression, and death. Although geese are considered the most sensitive poultry to T-2 toxin, the exact damage caused by T-2 toxin to geese is elusive. In the present study, a total of forty two 1-day-old healthy Yangzhou male goslings were randomly allotted seven diets contaminated with 0, 0.2, 0.4, 0.6, 0.8, 1.0, or 2.0 mg/kg T-2 toxin for 21 d, and the effects of T-2 toxin exposure on growth performance, feather quality, tibia development, and blood parameters were investigated. The results showed that T-2 toxin exposure significantly inhibited feed intake, body weight gain, shank length growth, and organ development (e.g., ileum, cecum, liver, spleen, bursa, and tibia) in a dose-dependent manner. In addition, the more serious feathering abnormalities and feather damage were observed in goslings exposed to a high dose of T-2 toxin (0.8, 1.0, and 2.0 mg/kg), which were mainly sparsely covered with short, dry, rough, curly, and gloss-free feathers on the back. We also found that hypertrophic chondrocytes of the tibial growth plate exhibited abnormal morphology and nuclear consolidation or loss, accompanied by necrosis and excessive apoptosis under 2.0 mg/kg T-2 toxin exposure. Moreover, 2.0 mg/kg T-2 toxin exposure triggered erythropenia, thrombocytosis, alanine aminotransferase, and aspartate aminotransferase activity, as well as high blood urea nitrogen, uric acid, and lactic dehydrogenase levels. Collectively, these data indicate that T-2 toxin had an adverse effect on the growth performance, feather quality, and tibia development, and caused liver and kidney damage and abnormal blood parameters in Yangzhou goslings, providing crucial information toward the prevention and control of T-2 toxin contamination in poultry feed.

Inflammation-related pathways involved in damaged articular cartilage of rats exposed to T-2 toxin based on RNA-sequencing analysis

Many studies have shown that ingestion of the T-2 toxin is harmful to articular cartilage. However, the mechanisms underlying damaged articular cartilage induced by T-2 toxin have not been elucidated. Twenty-four SD rats were randomly divided into T-2 toxin and control groups. In the control group, the 12 rats were administered 4% absolute ethanol by gavage, and in the T-2 toxin group, the 12 rats were administered T-2 toxin (100 ng/g, BW/day) by gavage. After the rats were sacrificed, the knee joints were collected, and RNA was extracted using TRIzol reagent for RNA sequencing (RNA-seq). Differentially expressed mRNA was identified based on p < 0.05 and | log₂ (fold change) | > 1. The T-2 toxin-related genes were obtained from the GeneCards database. An online tool (https://www.bioinformatics.com.cn) was used for enrichment analysis. Hematoxylin and eosin (H&E) staining was used to observe damaged articular cartilage, and immunohistochemical (IHC) staining was used to validate differentially expressed proteins. The H&E staining shows the number of cells decreased significantly, and the arrangement of chondrocytes became disordered in the T-2 toxin group. RNA-seq analysis identified 195 upregulated and 89 downregulated mRNAs in the T-2 toxin group. The top immune-related biological processes (Gene Ontology) were regulation of hormone secretion, regulation of peptide hormone secretion, and regulation of transcription involved in cell fate commitment. KEGG pathway enrichment analysis revealed that the IL-17 and tumor necrosis factor signaling pathways were significantly expressed, and the IL-17 signaling pathway was also identified in the enrichment analysis of T-2 toxin-related genes. Also, Mmp3, Tnf, Mapk10, Ccl11, Creb5, Cxcl2, and Cebpb were significantly enriched in the two pathways. The immunohistochemical staining showed that the levels of Mmp3 and Tnf proteins were significantly increased in the T-2 toxin group, which was consistent with the RNA-seq results. This study revealed the critical roles of IL-17 and TNF signaling pathways in damaged cartilage induced by T-2 toxin.

Mycotoxins occurrence in milk and cereals in North African countries - a review

North African countries; Algeria, Egypt, Libya, Morocco and Tunisia suffer from mycotoxin contamination. Various studies have indicated the presence of mycotoxins in raw milk and cereals (i.e. wheat, barley, maize and cereal-based products). Aflatoxins (AFs), Aflatoxin M1 (AFM1), Ochratoxin A (OTA), Fumonisin (FB1) and Zearalenone (ZEN)-mycotoxin are the most detected due to climatic change in the region. In this review, we will present the kind of foods and feeds cereals and milk based products contaminated and the level of their contaminated mycotoxin. On the other hand, researchers try to find biologic methods to remove/mitigate mycotoxins in food and feed using bio-products. But the research works concerning legislations and mycotoxin risk assessment still rare. Therefore, it appears necessary to make review on the current status of mycotoxins in North African countries in order to explore data related to contamination of basic food in this region and to highlight the problem to the policy-makers to establish a serious legislation on this matter. On the other hand, to give more information to the worldwide readers about the impact of climate change on the food and feed pollution on mycotoxins in the Mediterranean Sea region.

Fluorine impairs carboxylesterase 1-mediated hydrolysis of T-2 toxin and increases its chondrocyte toxicity

Background

T-2 toxin is recognized as one of the high-risk environmental factors for etiology and pathogenesis of Kashin-Beck disease (KBD). Previous evidence indicates decreased serum fluorine level in KBD patients. However, whether fluoride could regulate carboxylesterase 1 (CES1)-mediated T-2 toxin hydrolysis and alter its chondrocyte toxicity remains largely unknown.

Methods

In this study, in vitro hydrolytic kinetics were explored using recombinant human CES1. HPLC-MS/MS was used to quantitative determination of hydrolytic metabolites of T-2 toxin. HepG2 cells were treated with different concentration of sodium fluoride (NaF). qRT-PCR and western blot analysis were used to compare the mRNA and protein expression levels of CES1. C28/I2 cells were treated with T-2 toxin, HT-2 toxin, and neosolaniol (NEO), and then cell viability was determined by MTT assay, cell apoptosis was determined by Annexin V-FITC/PI, Hoechst 33258 staining, and cleaved caspase-3, and cell cycle was monitored by flow cytometry assay, CKD4 and CDK6.

Results

We identified that recombinant human CES1 was involved in T-2 toxin hydrolysis to generate HT-2 toxin, but not NEO, and NaF repressed the formation of HT-2 toxin. Both mRNA and protein expression of CES1 were significantly down-regulated in a dose-dependent manner after NaF treatment in HepG2 cells. Moreover, we evaluated the chondrocyte toxicity of T-2 toxin and its hydrolytic metabolites. Results showed that T-2 toxin induced strongest cell apoptosis, followed by HT-2 toxin and NEO. The decreased the proportion of cells in G0/G1 phase was observed with the descending order of T-2 toxin, HT-2 toxin, and NEO.

Conclusions

This study reveals that CES1 is responsible for the hydrolysis of T-2 toxin, and that fluoride impairs CES1-mediated T-2 toxin detoxification to increase its chondrocyte toxicity. This study provides novel insight into understanding the relationship between fluoride and T-2 toxin in the etiology of KBD.

T-2 toxin-induced femur lesion is accompanied by autophagy and apoptosis associated with Wnt/β-catenin signaling in mice

T-2 toxin is one of the most common mycotoxins found in grain foods, animal feed, and other agricultural by-products causing food contamination and health threat. The skeletal system is the main target tissue for T-2 toxin. T-2 toxin exposure is also recognized as a potential contributor to multiple types of bone diseases, including Kashin-Beck disease. However, the mechanisms of T-2 toxin-induced bone toxicity remain unclear. In this study, 60 male C57BL/6 mice were exposed T-2 toxin with 0, 0.5, 1 or 2 mg/kg body weight by intragastric administration for 28 days, respectively. Femora were collected for the detections of femur lesion, bone formation factors, oxidative stress, autophagy, apoptosis, and Wnt/β-catenin signaling. Our research showed that T-2 toxin caused bone formation disorders, presenting as the reduction of the BMD and femur length, bone structure changes and abnormal bone formation proteins expressions, along with enhanced oxidative stress. Meanwhile, T-2 toxin increased expressions of autophagy-related proteins (Beclin 1, ATG5, p62, and LC3), and promoted apoptosis in mouse femur. Moreover, T-2 toxin suppressed the Wnt/β-catenin signaling and expressions of downstream target genes. Taken together, our data indicated T-2 toxin-induced femur lesion was accompanied by autophagy and apoptosis, which was associated with Wnt/β-catenin signaling.

YAP plays a protective role in T-2 toxin-induced inhibition of chondrocyte proliferation and matrix degradation

Previous research has shown that T-2 toxin can damage cartilage, resulting in a disease phenotype similar to osteoarthritis. The precise molecular mechanism by which T-2 toxin causes chondrocyte injury, however, is unknown. The purpose of this study was to look into the role of YAP in T-2 toxin-induced rat chondrocyte injury. Based on research results, T-2 toxin decreased the levels of collagen II and PCNA while increasing the expression of matrix metalloproteinase MMP13. These findings supported the T-2 toxin's detrimental effect on chondrocytes. YAP's role in T-2 toxin-induced chondrocyte injury was also investigated. Total YAP and related nuclear proteins were found to decrease as the concentration of T-2 toxin increased. While PYAP expression was not significantly altered in response to T-2 toxin, the PYAP/YAP ratio decreased as the T-2 toxin concentration increased, implying that the HIPPO signaling pathway was activated. Furthermore, the YAP-specific inhibitor Verteporfin was used to investigate the role of YAP in T-2 toxin-induced chondrocyte injury. YAP inhibition increased MMP13 expression while decreasing COL2 and PCNA levels. In summary, the current study found that T-2 toxin decreased the levels of COL2 and PCNA while increasing the expression of MMP13 in chondrocytes after inhibiting YAP, providing a new insight into the mechanism of T-2 toxin-induced cartilage damage.

Determination of T-2 and HT-2 Toxins in Seed of Milk Thistle [Silybum marianum (L.) Gaertn.] Using Immunoaffinity Column by UPLC-MS/MS

Milk thistle [Silybum marianum (L.) Gaertn.] achieved a significant increase in interest over the past few years from local and foreign pharmaceutical corporations. The silymarin complex of constituents extracted from milk thistle achenes provides compelling health benefits primarily thanks to antioxidant activities and hepatoprotective effects. However, consuming mycotoxin-contaminated plant material can cause immunosuppression and hepatotoxic problems. The aim of this study was to develop and validate a method for the determination of mycotoxin content in milk thistle. Fusarium toxins as T-2 and HT-2 toxins in grown milk thistle harvested from a breeding station in the Czech Republic during 2020-2021 were studied. The analysis of T-2 and HT-2 toxins was performed by UPLC-MS/MS after immunoaffinity columns EASI-EXTRACT® T-2 & HT-2 clean up. All analysed samples of milk thistle were contaminated with T-2 toxin and HT-2 toxin. The content of T-2 toxin in the samples from 2020 was in the range of 122.7-290.2 µg/kg and HT-2 toxin 157.0-319.0 µg/kg. In 2021, the content of T-2 toxin was in the range of 28.8-69.9 µg/kg and HT-2 toxin was 24.2-75.4 µg/kg. The results show that the climatic conditions of the year of harvesting have a highly statistically significant effect on the content of T-2 and HT-2 toxins in milk thistle.

An integrative analysis of DNA methylation and transcriptome showed the dysfunction of MAPK pathway was involved in the damage of human chondrocyte induced by T-2 toxin

Background

T-2 toxin is thought to induce the growth plate and articular cartilage damage of Kashin-Beck disease (KBD), an endemic osteochondropathy in China. This study aims to explore the potential underlying mechanism of such toxic effects by integrating DNA methylation and gene expression profiles.

Methods

In this study, C28/I2 chondrocytes were treated with T-2 toxin (5 ng/mL) for 24 h and 72 h. Global DNA methylation level of chondrocyte was tested by Enzyme-Linked Immuno Sorbent Assay. Genome-wide DNA methylation and expression profiles were detected using Illumina Infinium HumanMethylation850 BeadChip and RNA-seq technique, respectively. Differentially methylated genes (DMGs) and differentially expressed genes (DEGs) were identified mainly for two stages including 24 h group versus Control group and 72 h group versus 24 h group. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed by Metascape. DMGs and DEGs were further validated by Sequenom MassARRAY system and quantitative real-time polymerase chain reaction.

Results

The global DNA methylation levels of chondrocytes exposed to T-2 toxin were significantly increased (P < 0.05). For 24 h group versus Control group (24 VS C), 189 DEGs and 590 DMGs were identified, and 4 of them were overlapping. For 72 h group versus 24 h group (72 VS 24), 1671 DEGs and 637 DMGs were identified, and 45 of them were overlapping. The enrichment analysis results of DMGs and DEGs both showed that MAPK was the one of the mainly involved signaling pathways in the regulation of chondrocytes after T-2 toxin exposure (DEGs: P_24VSc = 1.62 × 10^− 7; P_72VS24 = 1.20 × 10^− 7; DMGs: P_24VSc = 0.0056; P_72VS24 = 3.80 × 10^− 5).

Conclusions

The findings depicted a landscape of genomic methylation and transcriptome changes of chondrocytes after T-2 toxin exposure and suggested that dysfunction of MAPK pathway may play important roles in the chondrocytes damage induced by T-2 toxin, which could provide new clues for understanding the potential biological mechanism of KBD cartilage damage induced by T-2 toxin.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12860-021-00404-3.

Mechanism of DNA methylation-mediated downregulation of O6-Methylguanine-DNA methyltransferase in cartilage injury of Kashin-Beck Disease

OBJECTIVE

Kashin-Beck Disease (KBD) is an endemic osteoarthropathy, in which excessive apoptosis of chondrocytes occurs. O6-methylguanine-DNA methyltransferase (MGMT), a DNA damage repair gene, plays an important role in apoptosis but the mechanism is unclear in KBD cartilage injury. This study was to investigate the expression and promoter methylation of MGMT in KBD patients and its role in DNA damage and apoptosis of chondrocytes.

METHODS

MGMT mRNA and protein level were detected by quantitative real-time PCR and immunohistochemistry. Demethylation of MGMT was carried out using 5-Aza-2'-deoxycytidine, and the methylation level of MGMT promoter was measured by quantitative methylation specific PCR. Next, shRNA was used to knockdown the expression of MGMT. Cell viability, apoptosis and DNA damage were determined by MTT assay, flow cytometry, Hoechst 33342 staining and alkaline comet assay following T-2 toxin and selenium treatment.

RESULTS

MGMT protein expression and mRNA levels were decreased (p = 0.02, p = 0.007) and promoter methylation was increased (p = 0.008) in KBD patients. Meanwhile, MGMT level was upregulated by 5-Aza-2'-deoxycytidine in chondrocytes (p = 0.0002). DNA damage and apoptosis rates were increased in MGMT-silenced chondrocytes (all p < 0.0001). Furthermore, DNA damage and apoptosis were increseaed in chondrocytes treated with T-2 toxin (all p < 0.0001), but were decreased after selenium treatment (p < 0.0001, p = 0.01). Decreased mRNA level and increased methylation of MGMT were found in T-2 toxin group (p = 0.005, p = 0.002), while selenium reversed it (p = 0.02, p = 0.004).

CONCLUSIONS

MGMT might play a crucial part in the pathogenesis of KBD cartilage injury, which providing a therapeutic target for KBD.

Effect of Low Nutrition and T-2 Toxin on C28/I2 Chondrocytes Cell Line and Chondroitin Sulfate-Modifying Sulfotransferases

OBJECTIVE

To investigate the effects of low nutrition and trichothecenes-2 toxin (T-2) on human chondrocytes cell line C28/I2 and the gene expression levels of some chondroitin sulfate (CS)-modifying sulfotransferases.

METHODS

The chondrocytes were divided into 4 intervention groups: (a) control group (Dulbecco's modified Eagle's medium/Nutrient Mixture F-12 [DMEM/F-12] with fetal bovine serum [FBS]), (b) low-nutrition group (DMEM/F-12 without FBS), (c) T-2 group (DMEM/F-12 with FBS plus 20 ng/mL T-2), and (d) combined group (DMEM/F-12 without FBS plus 20 ng/mL T-2). Twenty-four hours postintervention, ultrastructural changes in the chondrocytes were observed by transmission electron microscopy (TEM). Live cell staining and methyl thiazolyl tetrazolium (MTT) assay were performed to observe cell viability. The expression of CS-modifying sulfotransferases, including carbohydrate sulfotransferase 3, 12, 13, 15 (CHST-3, CHST-12, CHST-13, and CHST-15, respectively), and uronyl 2-O-sulfotransferase (UST) were examined by quantitative real-time polymerase chain reaction (RT-qPCR) analysis.

RESULTS

The cells in the T-2 group and combined group had significantly lower live cell counts and relative survival rates than the control group. TEM pictures revealed decreased electron density of mitochondria in the low-nutrition group. The T-2 group and combined group both caused mitochondrial swelling, damage, and reduction in mitochondrial number. RT-qPCR showed a trend of altered expression of CHST and increased expression of UST genes under low-nutrition, T-2 toxin and combined interventions.

CONCLUSIONS

These results show early-stage Kashin-Beck disease chondrocyte pathophysiology, consisting of chondrocyte cell damage and compensatory upregulation of CHST and UST genes.

Patients with Osteoarthritis and Kashin-Beck Disease Display Distinct CpG Methylation Profiles in the DIO2, GPX3, and TXRND1 Promoter Regions

OBJECTIVE

We aimed to analyze deoxycytidine-deoxyguanosine dinucleotide (CpGs) methylation profiles in DIO2, GPX3, and TXNRD1 promoter regions in osteoarthritis (OA) and Kashin-Beck disease (KBD) patients.

METHODS

Blood samples were collected from 16 primary OA patients and corresponding 16 healthy individuals and analyzed for methylations in the CpGs of DIO2, GPX3, and TXNRD1 promoter regions using MALDI-TOF-MS. The methylation profiles of these regions were then compared between OA and KBD patients.

RESULTS

DIO2-1_CpG_2 and DIO2-1_CpG_3 methylations were significantly lower in OA than KBD patients (P < 0.05). A similar trend was observed for GPX3-1_CpG_4, GPX3-1_CpG_7, GPX3-1_CpG_8.9.10, GPX3-1_CpG_13.14.15 and GPX3-1_CpG_16 (P < 0.05) as well as TXNRD1-1_CpG_1 and TXNRD1-1_CpG_2 methylation between OA and KBD patients (P < 0.05). However, there was no difference in methylation levels of other CpGs between the 2 groups (P > 0.05).

CONCLUSION

OA and KBD patients display distinct methylation profiles in the CpG sites of DIO2, GPX3, and TXNRD1 promoter regions. These findings provide a strong background and new perspective for future studies on mechanisms underlying epigenetic regulation of selenoprotein genes associated with OA and KBD diseases.

LncRNAs as a new regulator of chronic musculoskeletal disorder

Objectives

In recent years, long non‐coding RNAs (lncRNAs) have been found to play a role in the occurrence, progression and prognosis of chronic musculoskeletal disorders.

Design and methods

Literature exploring on PubMed was conducted using the combination of keywords 'LncRNA' and each of the following: 'osteoarthritis', 'rheumatoid arthritis', 'osteoporosis', 'osteogenesis', 'osteoclastogenesis', 'gout arthritis', 'Kashin‐Beck disease', 'ankylosing spondylitis', 'cervical spondylotic myelopathy', 'intervertebral disc degeneration', 'human muscle disease' and 'muscle hypertrophy and atrophy'. For each disorder, we focused on the publications in the last five years (5/1/2016‐2021/5/1, except for Kashin‐Beck disease). Finally, we excluded publications that had been reported in reviews of various musculoskeletal disorders during the last three years. Here, we summarized the progress of research on the role of lncRNA in multiple pathological processes during musculoskeletal disorders.

Results

LncRNAs play a crucial role in regulating downstream gene expression and maintaining function and homeostasis of cells, especially in chondrocytes, synovial cells, osteoblasts, osteoclasts and skeletal muscle cells.

Conclusions

Understanding the mechanisms of lncRNAs in musculoskeletal disorders may provide promising strategies for clinical practice.

Fungal Toxins and Host Immune Responses

Fungi are ubiquitous organisms that thrive in diverse natural environments including soils, plants, animals, and the human body. In response to warmth, humidity, and moisture, certain fungi which grow on crops and harvested foodstuffs can produce mycotoxins; secondary metabolites which when ingested have a deleterious impact on health. Ongoing research indicates that some mycotoxins and, more recently, peptide toxins are also produced during active fungal infection in humans and experimental models. A combination of innate and adaptive immune recognition allows the host to eliminate invading pathogens from the body. However, imbalances in immune homeostasis often facilitate microbial infection. Despite the wide-ranging effects of fungal toxins on health, our understanding of toxin-mediated modulation of immune responses is incomplete. This review will explore the current understanding of fungal toxins and how they contribute to the modulation of host immunity.

Molecular Aspects of Mycotoxins-A Serious Problem for Human Health

Mycotoxins are toxic fungal secondary metabolities formed by a variety of fungi (moulds) species. Hundreds of potentially toxic mycotoxins have been already identified and are considered a serious problem in agriculture, animal husbandry, and public health. A large number of food-related products and beverages are yearly contaminated by mycotoxins, resulting in economic welfare losses. Mycotoxin indoor environment contamination is a global problem especially in less technologically developed countries. There is an ongoing effort in prevention of mould growth in the field and decontamination of contaminated food and feed in order to protect human and animal health. It should be emphasized that the mycotoxins production by fungi (moulds) species is unavoidable and that they are more toxic than pesticides. Human and animals are exposed to mycotoxin via food, inhalation, or contact which can result in many building-related illnesses including kidney and neurological diseases and cancer. In this review, we described in detail the molecular aspects of main representatives of mycotoxins, which are serious problems for global health, such as aflatoxins, ochratoxin A, T-2 toxin, deoxynivalenol, patulin, and zearalenone.

Reduced expression of α2 integrin is involved in T-2 toxin-induced matrix degradation in C28/I2 cells and cartilages from rats administrated with T-2 toxin

T-2 toxin is a mycotoxin demonstrating several harmful effects on chondrocyte and cartilage functions. In the present study, we investigated the toxic effects of T-2 toxin on cartilage matrix degradation and evaluated the involvement of α2 integrin in T-2 toxin-induced matrix damage. In C28/I2 cells, T-2 toxin decreased cell viability in a dose-dependent manner. Regarding matrix degradation, T-2 toxin decreased type II collagen and increased matrix metalloproteinase 13 (MMP-13) expression. Moreover, T-2 toxin significantly decreased the expression of α2 integrin in C28/I2 cells, indicating impaired chondrocyte-matrix interaction. Additionally, cartilage matrix degradation with decreased type II collagen expression was observed in the animal model, established using rats treated with T-2 toxin, with or without a selenium-deficient diet, presenting chondrocytes with necrosis in the deep zone. Simultaneously, rats administered T-2 toxin demonstrated overtly decreased α2 integrin expression in the articular cartilage. In the T-2 toxin plus selenium-deficient diet group, α2 integrin expression was further decreased in the deep zone of the cartilage. Furthermore, inhibition of α2β1 integrin in C28/I2 cells could induce MMP-13 activation and type II collagen reduction, contributing to matrix degradation. These results indicate that the cytotoxic effects of T-2 toxin on chondrocyte damage and cartilage matrix degradation are associated with α2 integrin downregulation, by reducing type II collagen and MMP-13 activation.

The molecular mechanism study of COMP involved in the articular cartilage damage of Kashin-Beck disease

Aims

Kashin-Beck disease (KBD) is a kind of chronic osteochondropathy, thought to be caused by environmental risk factors such as T-2 toxin. However, the exact aetiology of KBD remains unclear. In this study, we explored the functional relevance and biological mechanism of cartilage oligosaccharide matrix protein (COMP) in the articular cartilage damage of KBD.

Methods

The articular cartilage specimens were collected from five KBD patients and five control subjects for cell culture. The messenger RNA (mRNA) and protein expression levels were detected by quantitative reverse transcription PCR (qRT-PCR) and western blot. The survival rate of C28/I2 chondrocyte cell line was detected by MTT assay after T-2 toxin intervention. The cell viability and mRNA expression levels of apoptosis related genes between COMP-overexpression groups and control groups were examined after cell transfection.

Results

The mRNA and protein expression levels of COMP were significantly lower in KBD chondrocytes than control chondrocytes. After the T-2 toxin intervention, the COMP mRNA expression of C28/I2 chondrocyte reduced and the protein level of COMP in three intervention groups was significantly lower than in the control group. MTT assay showed that the survival rate of COMP overexpression KBD chondrocytes were notably higher than in the blank control group. The mRNA expression levels of Survivin, SOX9, Caspase-3, and type II collagen were also significantly different among COMP overexpression, negative control, and blank control groups.

Conclusion

Our study results confirmed the functional relevance of COMP with KBD. COMP may play an important role in the excessive chondrocytes apoptosis of KBD patients.Cite this article: Bone Joint Res 2020;9(9):578-586.

The integrative analysis of DNA methylation and mRNA expression profiles confirmed the role of selenocompound metabolism pathway in Kashin-Beck disease

Kashin-Beck disease (KBD) is an endemic chronic osteochondropathy. The etiology of KBD remains unknown. In this study, we conducted an integrative analysis of genome-wide DNA methylation and mRNA expression profiles between KBD and normal controls to identify novel candidate genes and pathways for KBD. Articular cartilage samples from 17 grade III KBD patients and 17 healthy controls were used in this study. DNA methylation profiling of knee cartilage and mRNA expression profile data were obtained from our previous studies. InCroMAP was performed to integrative analysis of genome-wide DNA methylation profiles and mRNA expression profiles. Gene ontology (GO) enrichment analysis was conducted by online DAVID 6.7. The quantitative real-time polymerase chain reaction (qPCR), Western blot, immunohistochemistry (IHC), and lentiviral vector transfection were used to validate one of the identified pathways. We identified 298 common genes (such as COL4A1, HOXA13, TNFAIP6 and TGFBI), 36 GO terms (including collagen function, skeletal system development, growth factor), and 32 KEGG pathways associated with KBD (including Selenocompound metabolism pathway, PI3K-Akt signaling pathway, and TGF-beta signaling pathway). Our results suggest the dysfunction of many genes and pathways implicated in the pathogenesis of KBD, most importantly, both the integrative analysis and in vitro study in KBD cartilage highlighted the importance of selenocompound metabolism pathway in the pathogenesis of KBD for the first time.

Magnetic resonance imaging at 7.0 T for evaluation of early lesions of epiphyseal plate and epiphyseal end in a rat model of Kashin-Beck disease

Background

Kashin–Beck disease (KBD) is a disabling osteoarticular disease involving growth and joint cartilage. Early diagnosis can effectively prevent the progress of the disease. However, the early diagnosis of it is still very difficult. Our aim was to study the knee joint lesions of a rat KBD model using ultra-high field magnetic resonance imaging (MRI) and compare it with X-ray imaging to analyze the possible MRI manifestations of KBD, and to further explore ways to determine the pathological damage of KBD in the early stage.

Methods

A total of 96 Wistar rats were selected and randomly divided into 4 groups: normal diet (Group A), KBD-affected diet (Group B), normal diet+T-2 toxin (Group C), and KBD-affected diet+T-2 toxin (Group D). T-2 toxin was administered at a dose of 0.1 mg/kg/day. In the 4th week, 8th week, and 12th week, eight rats randomly selected in each group were sacrificed by cervical dislocation after undergoing X-ray and 7.0 T MRI imaging, and then knee joints were harvested, sliced, and subjected to hematoxylin-eosin (H&E) staining.

Results

Characteristic image changes including of continuity interruption and early closure and fusion of epiphyseal plates were observed on T1WI in rat model of KBD. The total necrosis rates in the H&E stain of group A to group D were 4.35, 52.38, 33.3, and 73.68%, respectively. The positive rate of image change under 7.0 T MRI was 0.833 VS. that under X-ray was 0.33 (P = 0.001).

Conclusions

MRI at 7.0 T is highly sensitive to the early pathological changes of the epiphysis, epiphyseal plate, and metaphyseal end, which can improve imaging positive rate of KBD and decrease the rate of missed diagnosis. This imaging modality can be used for research on early joint lesions and for early diagnosis of KBD.

Protective effect of selenomethionine on intestinal injury induced by T- 2 toxin

T-2 toxin is the most toxic as a type A trichothecenes, which could contaminate grains, especially in wheat and corn. It can cause immune suppression, neurotoxicity, the apoptosis of cells and even induce tumorigenesis. Recent studies have indicated that selenium (Se) have protective effect against mycotoxins-induced toxicity. The present studies was designed to investigate the protective role of Selenomethionine (SeMet) on T-2 toxin-induced toxicity in rabbit's jejunum. 50 New Zealand rabbits were divided into five group (Control group, T-2 group, low-dose Se + T-2 group, medium-dose + T-2 group and high-dose Se + T-2 group). New Zealand rabbits were orally administered with SeMet (0.2, 0.4 and 0.6 mg/kg, Adding diet) for 21 days. On 17th days, each group began to take 0.4 mg/kg of T-2 toxin orally every day for 5 days. We found that rabbit exposed to T-2 toxin could increase the levels of ROS, and decrease activities of antioxidant enzymes and the expression of Occludin and ZO-1. In addition, T-2 toxin could trigger jejunal inflammatory response and enhance the expression of IL-1β, IL-6 and TNF-α. After SeMet pretreatment, our results indicated that Se attenuated the T-2 toxin-induced oxidative stress, decreasing the level of ROS, MDA and enhancing the activity of SOD and GSH-Px. Moreover, SeMet can alleviate jejunal inflammatory response, and protect the integrity of the intestinal barrier through up-regulating the expression of ZO-1 and Occludin. In the present research, supplementation of 0.2 mg/kg SeMet in the diet could effectively alleviate the T-2 toxin poisoning in rabbits.

Cytotoxic Properties of HT-2 Toxin in Human Chondrocytes: Could T3 Inhibit Toxicity of HT-2?

Thyroid hormone triiodothyronine (T₃) plays an important role in coordinated endochondral ossification and hypertrophic differentiation of the growth plate, while aberrant thyroid hormone function appears to be related to skeletal malformations, osteoarthritis, and Kashin-Beck disease. The T-2 toxin, present extensively in cereal grains, and one of its main metabolites, HT-2 toxin, are hypothesized to be potential factors associated with hypertrophic chondrocyte-related osteochondropathy, known as the Kashin-Beck disease. In this study, we investigated the effects of T₃ and HT-2 toxin on human chondrocytes. The immortalized human chondrocyte cell line, C-28/I2, was cultured in four different groups: controls, and cultures with T₃, T₃ plus HT-2 and HT-2 alone. Cytotoxicity was assessed using an MTT assay after 24-h-exposure. Quantitative RT-PCR was used to detect gene expression levels of collagen types II and X, aggrecan and runx2, and the differences in runx2 were confirmed with immunoblot analysis. T₃ was only slightly cytotoxic, in contrast to the significant, dose-dependent cytotoxicity of HT-2 alone at concentrations ≥ 50 nM. T₃, together with HT-2, significantly rescued the cytotoxic effect of HT-2. HT-2 induced significant increases in aggrecan and runx2 gene expression, while the hypertrophic differentiation marker, type X collagen, remained unchanged. Thus, T₃ protected against HT-2 induced cytotoxicity, and HT-2 was an inducer of the pre-hypertrophic state of the chondrocytes.

Competitive fluorometric assay for the food toxin T-2 by using DNA-modified silver nanoclusters, aptamer-modified magnetic beads, and exponential isothermal amplification

The authors describe an aptamer based assay for the mycotoxin T-2. The method is making use of exponential isothermal amplification reaction (EXPAR) and fluorescent silver nanoclusters (AgNCs). Free T-2 and cDNA (which is a DNA that is partially complementary to the aptamer) compete for binding to aptamer-modified magnetic beads. The cDNA collected by magnetic separation can be used as a primer to trigger EXPAR to obtain ssDNA. The C-base-rich ssDNA binds and reduces Ag(I) ion to form fluorescent AgNCs. Fluorescence is measured at excitation/emission wavelengths of 480/525 nm. T-2 can be detected by fluorometry with a detection limit as low as 30 fg·mL^-1. The method was applied to analyse spiked oat and corn, and the average recoveries ranged from 97.3 to 102.3% and from 95.9 to 107.5%, respectively. The results were in good agreement with data of the commercial ELISA kit. The assay is highly sensitive, has a wide analytical range, good specificity and reliable operation. It provides a promising alternative for the standard method for quantitative detection of T-2. Graphical abstract Schematic presentation of fluorometric assay for T-2 based on aptamer-functionalized magnetic beads exponential, isothermal amplification reaction (EXPAR) and fluorescent silver nanoclusters (AgNCs).

Selenium distribution in the Chinese environment and its relationship with human health: A review

This paper reviewed the Se in the environment (including total Se in soil, water, plants, and food), the daily Se intake and Se content in human hair were also examined to elucidate Se distribution in the environment and its effects on human health in China. Approximately 51% of China is Se deficiency in soil, compared with 72% in the survey conducted in 1989. Low Se concentrations in soil, water, plants, human diet and thus human hair were found in most areas of China. The only significant difference was observed between Se-rich and Se-excessive areas for Se contents in water, staple cereal, vegetables, fruits, and animal-based food, no remarkable contrast was found among other areas (p>0.05). This study also demonstrated that 39-61% of Chinese residents have lower daily Se intakes according to WHO/FAO recommended value (26-34μg/day). Further studies should focus on thoroughly understanding the concentration, speciation, and distribution of Se in the environment and food chain to successfully utilize Se resources, remediate Se deficiency, and assess the Se states and eco-effects on human health.

Long noncoding RNA expression profile reveals lncRNAs signature associated with extracellular matrix degradation in kashin-beck disease

Kashin-Beck disease (KBD) is a deformative, endemic osteochondropathy involving degeneration and necrosis of growth plates and articular cartilage. The pathogenesis of KBD is related to gene expression and regulation mechanisms, but long noncoding RNAs (lncRNAs) in KBD have not been investigated. In this study, we identified 316 up-regulated and 631 down-regulated lncRNAs (≥ 2-fold change) in KBD chondrocytes using microarray analysis, of which more than three-quarters were intergenic lncRNAs and antisense lncRNAs. We also identified 232 up-regulated and 427 down-regulated mRNAs (≥ 2-fold change). A lncRNA-mRNA correlation analysis combined 343 lncRNAs and 292 mRNAs to form 509 coding-noncoding gene co-expression networks (CNC networks). Eleven lncRNAs were predicted to have cis-regulated target genes, including NAV2 (neuron navigator 2), TOX (thymocyte selection-associated high mobility group box), LAMA4 (laminin, alpha 4), and DEPTOR (DEP domain containing mTOR-interacting protein). The differentially expressed mRNAs in KBD significantly contribute to biological events associated with the extracellular matrix. Meanwhile, 34 mRNAs and 55 co-expressed lncRNAs constituted a network that influences the extracellular matrix. In the network, FBLN1 and LAMA 4 were the core genes with the highest significance. These novel findings indicate that lncRNAs may play a role in extracellular matrix destruction in KBD.

Trichothecenes: immunomodulatory effects, mechanisms, and anti-cancer potential

Paradoxically, trichothecenes have both immunosuppressive and immunostimulatory effects. The underlying mechanisms have not been fully explored. Early studies show that dose, exposure timing, and the time at which immune function is assessed influence whether trichothecenes act in an immunosuppressive or immunostimulatory fashion. Recent studies suggest that the immunomodulatory function of trichothecenes is also actively shaped by competing cell-survival and death-signaling pathways. Autophagy may also promote trichothecene immunosuppression, although the mechanism may be complicated. Moreover, trichothecenes may generate an "immune evasion" milieu that allows pathogens to escape host and vaccine immune defenses. Some trichothecenes, especially macrocyclic trichothecenes, also potently kill cancer cells. T-2 toxin conjugated with anti-cancer monoclonal antibodies significantly suppresses the growth of thymoma EL-4 cells and colon cancer cells. The type B trichothecene diacetoxyscirpenol specifically inhibits the tumor-promoting factor HIF-1 in cancer cells under hypoxic conditions. Trichothecin markedly inhibits the growth of multiple cancer cells with constitutively activated NF-κB. The type D macrocyclic toxin Verrucarin A is also a promising therapeutic candidate for leukemia, breast cancer, prostate cancer, and pancreatic cancer. The anti-cancer activities of trichothecenes have not been comprehensively summarized. Here, we first summarize the data on the immunomodulatory effects of trichothecenes and discuss recent studies that shed light on the underlying cellular and molecular mechanisms. These mechanisms include autophagy and major signaling pathways and their crosstalk. Second, the anti-cancer potential of trichothecenes and the underlying mechanisms will be discussed. We hope that this review will show how trichothecene bioactivities can be exploited to generate therapies against pathogens and cancer.

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.

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

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

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.