Increased FGFR3 is involved in T-2 toxin-induced lesions of hypertrophic cartilage associated with endemic osteoarthritis

Abstract

This study evaluated the effect of fibroblast growth factor receptor 3 (FGFR3) on damaged hypertrophic chondrocytes of Kashin–Beck disease (KBD). Immunohistochemical staining was used to evaluate FGFR3 expression in growth plates from KBD rat models and engineered cartilage. In vitro study, hypertrophic chondrocytes were pretreated by FGFR3 binding inhibitor (BGJ398) for 24 h before incubation at different T-2 toxin concentrations. Differentiation -related genes (Runx2, Sox9, and Col Ⅹ) and ECM degradation -related genes (MMP-13, Col Ⅱ) in the hypertrophic chondrocytes were analyzed using RT-PCR, and the corresponding proteins were analyzed using western blotting. Hypertrophic chondrocytes death was detected by the Annexin V/PI double staining assay. The integrated optical density of FGFR3 staining was increased in knee cartilage of rats and engineered cartilage treated with T-2 toxin. Both protein and mRNA levels of Runx2, Sox9, Col Ⅱ, and Col Ⅹ were decreased in a dose-dependent manner when exposed to the T-2 toxin and significantly upregulated by 1 μM BGJ398. The expression of MMP-1, MMP-9, and MMP-13 increased in a dose-dependent manner when exposed to T-2 toxin and significantly reduced by 1 μM BGJ398. 1 μM BGJ398 could prevent early apoptosis and necrosis induced by the T-2 toxin. Inhibiting the FGFR3 signal could alleviate extracellular matrix degradation, abnormal chondrocytes differentiation, and excessive cell death in T-2 toxin-induced hypertrophic chondrocytes.

Introduction

Kashin-Beck disease (KBD) is a persistent osteoarthritis that is endemic and may occur as early as the ages of 2 to 3 years old. The major feature of the KBD is short stature due to the occurrence of multiple focal necroses within growth plates samples. ¹ Growth plate chondrocytes are spatially organized in reserve, proliferative, and hypertrophic zones characterized by three functional states of the cells. The main engine of bone growth is hypertrophic chondrocytes, ² and hypertrophic lesions of the cartilage are the fundamental pathological features of KBD. Thereby, we focused on the hypertrophic cartilage.

The etiology of KBD is still poorly defined. T-2 toxin presence in grains has been documented in regions where KBD is prevalent.^3,4 The prevalence of KBD exhibited a significant reduction, declining from 12.31% to 4.21% between 2000 and 2007. ⁵ In addition, food items containing T-2 toxin were linked to pathological alterations in animal cartilage that exhibited resemblances to the hypertrophic cartilage observed in patients with KBD. ⁶ Thus, it is hypothesized that T-2 toxin may increase the susceptibility of individuals to KBD. Throughout this investigation, we utilized T-2 toxin-activated rat and hypertrophic chondrocytes as in vivo and in vitro KBD models, respectively.

Matrix deterioration, aberrant differentiation of chondrocytes, and excessive cellular apoptosis in hypertrophic cartilage are the main pathological outcomes of KBD. ¹ Type II collagen (Col II), the primary extracellular matrix (ECM) constituent in cartilage, is greatly reduced in KBD, which is associated with its excessive cleavage and the upregulation and increased activity of collagenases, mainly those associated with matrix metalloproteinase 13 (MMP-13). ⁷ The abnormal chondrocyte differentiation in KBD joint lesions is followed by genes overexpression, including parathyroid hormone-related protein, Type X collagen (Col X), Transforming growth factor-β (TGF-β), basic Fibroblast growth factor (FGF), and vascular endothelial growth factor, ⁸ and so on. These genes participate in chondrocyte hypertrophy modulation in the course of endochondral ossification. Nonetheless, the aforementioned mechanism remains largely unexplored.

The regulation of chondrocyte progression and differentiation is purportedly influenced by FGF signaling. The expression of four FGF receptor genes is observed throughout all phases of endochondral bone development. ⁹ Furthermore, increased FGFR3 staining has been observed in both children cartilage and animal model of KBD. ¹⁰ However, the specific impact of FGFR3 in pathological development remains unknown. Hence, the present investigation efforts to go deeper into the mechanism of FGFR3 in the onset of KBD from three distinctive levels: cell culture (in vitro), animal model (in vivo), and participants (in vivo). We hypothesized that FGFR3 is involved in developing KBD by regulating abnormal differentiation of hypertrophic chondrocytes, ECM degradation, and death of hypertrophic chondrocytes.

Methods

Human and animal samples

The present investigation received approval from the Human and Ethical Committee for Medical Research at Xi'an Jiaotong University (Approval number: #0075). To show the pathological modifications within KBD growth plate, there were two human samples in this study, one from child with KBD and the other from control child. Both donors were died of road traffic accidents. Samples from child donors were collected with the consent of their parents or legal guardians. Samples of cartilage were obtained from the phalanges of the hand. The individual who provided the donation was identified as having KBD through the implementation of the diagnostic criteria for KBD that are recognized at a national level in China community (diagnostic code S/T 207-2010), utilizing the right-hand radiographs and cartilage segments that underwent staining with hematoxylin and eosin (H&E). The validation of the KBD donor was conducted by means of histological analysis of the cartilage sections following H&E staining.

The Experimental Animal Center of Xi'an Jiaotong University provided male Sprague Dawley (SD) rats that utilized in our study. All animals were of the same age, specifically 1 month old, and exhibited a weight range of 60 to 80 g. The T-2 toxin was procured from Toronto Research Chemicals (Toronto, Canada). The T-2 toxin was dissolved in 100 ul absolute ethanol and diluted it with 0.9% normal saline solution to 5 mg/mL storage solution for preservation. And according to experimental requirements, we diluted storage solution with normal saline to working concentration. A group of 12 rats was subjected to random separation into two distinct groups. The experimental group was administered a daily dose of 100 ng/g of BW, which was frequently referred to as the T-2 toxin group. In contrast, the control group was given 0.9% normal saline solution. In both instances, the interventions were delivered via the intragastric route over a period of 4 weeks. The specimens were obtained from the rats subsequent to intraperitoneal administration utilizing an overdose of barbiturate (200 mg/kg). The study's protocol was approved by the ethics committee of Xi'an Jiaotong University, and all investigations were conducted in compliance with the Helsinki Declaration.

Engineered cartilage preparation

The present study involved the preparation and sterilization of scaffolds composed of demineralized bone matrix gelatine (BMG) as described earlier. ¹¹ In this study, a suspension of 1.0 × 10⁶ ATDC5 chondrocytes was prepared using 100 μL of Dulbecco's modified eagle medium F-12 (DMEM/F-12) and subsequently cultured on BMG scaffolds within 10 mL centrifuge glass tubes. The ATDC5 cell line was generated through a population of differentiating AT805 teratocarcinoma cells and exhibits chondrogenic properties ¹² and have been obtained from the European Collection of Cell Cultures (Salisbury, UK). After 4 h, a 4 mL sample of culture medium comprising 10% (v/v) fetal bovine serum (FBS) was meticulously introduced to the chondrocytes-cancellous BMG construct, which was subsequently cultivated for an additional period of 14 days. The medium was replaced bi-daily.

Hypertrophic chondrocyte culture

Hypertrophic Chondrocytes were exposed to FGFR3 binding inhibitor (BGJ398, APExBIO Technology, Houston, USA) for 24 h before incubation in different T-2 toxin concentrations. As our pilot study (shown in supplementary file 1), the viability of chondrocytes treated with 1 μM BGJ398 was almost the same at 24 h as at 0 h 24 h was selected as the time point for this experiment. According to our previous studies, 0, 10, 20, 50 ng/mL T-2 toxin for 48 h were used in ATDC5 hypertrophic chondrocytes. ¹³

Assessment of gene expression

Utilizing TRIzol (Thermo Fisher Scientific, Waltham, USA), the isolation of total RNA from chondrocytes entailed was conducted. The process of synthesizing first-strand cDNA was carried out employing the RevertAid First Strand cDNA Synthesis kit (Thermo Fisher Scientific, Waltham, USA). Quantification of gene expression levels was performed using reverse transcription polymerase chain reaction (RT-PCR). The supplementary file 2 contains information regarding the primers utilized in this investigation.

Assessment of protein expression

Immunohistochemical staining (IHC staining) was used to assess expression of FGFR3. FGFR3 (1:400, Abcam, Cambridge, UK) underwent incubation at 4°C overnight based on the manufacturer’s guidelines. Subsequently, the tissue sections underwent diaminobenzidine staining and were subsequently observed utilizing a light microscope (Olympus Corporation, Japan), and photographed by using of a digital camera (Canon Corporation, Japan). The evaluation of cytoplasmic brown granules exhibiting FGFR3 positive staining was performed by means of integrated optical density (IOD). The Image-Pro Plus 6.0 (Media Cybernetics, Inc., Rockville, MD) software was utilized to perform the analysis, and three fields from each sample were chosen at random for analysis.

Western blotting assay was used to assess expression of proteins relative with chondrocytes differentiation (Runx2, Sox9 and Col Ⅹ) and extracellular matrix degradation (MMP-13, Col II). Using SDS-PAGE, equivalent quantities of total protein were subjected to separation and then transferred to a polyvinylidene difluoride membrane (EMD Millipore, Billerica, MA, USA). Subsequent to the process of inhibition, the membranes underwent incubation utilizing primary antibodies targeting Runx2 (1:1000, Abcam, Cambridge, UK), Sox9 (1:500, Santa Cruz, Dallas, USA), Col Ⅹ (1:1000, Abcam, Cambridge, UK), MMP-13 (1:1000, Abcam, Cambridge, UK), Col II (1: 1000, Proteintech Wuhan, China) and GAPDH (1:1500, Bioss, Beijing, China), according to the respective manufacturers’ protocol. The internal control utilized in the study was GAPDH.

Assessment of chondrocytes death

We used flow cytometry to analysis chondrocytes death. A total of 5 × 10⁵ chondrocytes underwent incubation via 10 μL Media Binding Reagent and 1.25 μL Annexin VFITC (BD Biosciences, Franklin Lakes, USA). After the media was extracted, the cells were carefully subjected to resuspension process in 0.5 mL of cold 1× binding buffer and underwent an incubation process utilizing 10 μL of propidium iodide (PI) (BD Biosciences, Franklin Lakes, USA). The specimens were subjected to analysis using a flow cytometer (BD Biosciences, Franklin Lakes, USA).

Statistical analysis

Quantitative data are expressed as mean ± standard deviation (SD) obtained from three distinct investigations. Statistical analyses were conducted utilizing One-way analysis of variance (ANOVA) and Student's t-test. Statistical significance was set at p ≤ .05.

Results

Growth plates morphology from children diagnosed with KBD

The H&E staining of growth plates from KBD and control children’s donors are displayed in Figure 1. In KBD's growth plate, chondral necrosis was identified through the observation of the disappearance of cartilage cells, leaving behind only red outlines of chondrocytes that displayed a more lighted blue color upon staining with H&E (displayed as a black arrow in Figure 1(b)). This was unobserved throughout the control growth plates (Figure 1(a)). KBD was found to exhibit matrix loss in the hypertrophic zone of the growth plate, represented by black stars (Figure 1(b)).

Figure 1.

H&E staining of growth plates from children. (a) Growth plates from a normal child (male, 5 years old); (b) Growth plates from a KBD child (male, 4 years old).

Overexpression of FGFR3 in T-2 toxin-treated rats and engineered growth plates

Considering our prior investigation, ¹⁰ FGFR3 was overexpressed in hypertrophic chondrocytes and KBD cartilage. To further investigate the correlation between FGFR3 and KBD, IHC staining was utilized to assess the FGFR3 expression in rats and genetically modified growth plates that were treated via T-2 toxin. As illustrated in Figure 2, FGFR3 protein was observed to be present in the cellular membrane as well as in the surrounding cytoplasmic region. The rat growth plates that were subjected to T-2 toxin treatment exhibited a notable presence of strong FGFR3 staining in their hypertrophic zone (Figure 2(a)). The statistical analysis indicated that the integrated optical density (IOD) of FGFR3 in the cartilage of T-2 toxin-treated rats was twice that of the control group (Figure 2(b)). Throughout the engineered growth plates, IOD of FGFR3 within the observed T-2 toxin group was three-fold that of the control (Figure 2(c)).

Figure 2.

Expression of FGFR3 with IHC staining. (a), (c) FGFR3 staining rat and engineered growth plates; (b), (d) The IOD analysis of FGFR3 in rat and engineered growth plates. (For rat growth plates, n = 6; for engineered growth plates, n = 3. *p < .05 versus control). IOD: integrated optical density.

Selection of FGFR3 inhibitor concentrations in hypertrophic chondrocytes

The hypertrophic chondrocytes are most likely the target cells of KBD. The ATDC5 cells underwent hypertrophic differentiation through exposure to insulin transferrin–selenium (ITS) differentiation medium for a duration of 3 weeks.^13,14 Throughout this investigation, the staining intensity of alcian blue exhibited a progressive elevation as the ATDC5 cells underwent successive stages of differentiation (Figure 3(a)-I), demonstrating that the proteoglycan content of chondrocytes gradually increased. The Col Ⅹ expression is a significant indicator of hypertrophic chondrocytes, ¹⁵ was also increased, peaking at 3 weeks (Figure 3(a)-II).

Figure 3.

Selection of BGJ398 concentration. (a) Establishment of ATDC5 hypertrophic chondrocytes; (b) Selection of BGJ398 concentration in hypertrophic chondrocytes. (n = 3, *p < .05 versus 0w or 0 nM).

To evaluate the impact of FGFR3 on T-2 toxin-activated hypertrophic chondrocytes activity, we used BGJ398, a FGFR3 inhibitor, to detect the hypertrophic chondrocytes cell viability following treatment with 0–5 μM BGJ398 for a period of 24 h by the MTT assay. Concentrations up to 1 μM were found to be non-toxic (Figure 3(b)). Hence, a concentration of 1 μM was employed as the FGFR3 inhibitor in subsequent investigations.

Increased differentiation-related genes in damaged hypertrophic chondrocyte after treatment with FGFR3 suppressor

To elucidate the impact of the upregulation process of FGFR3 expression within KBD, we assessed the effects of FGFR3 inhibitor on genes expression included in the differentiation of impaired hypertrophic chondrocytes activated by T-2 toxin. Runx2, Sox9, and Col Ⅹ were selected as chondrocyte differentiation markers. As depicted in Figure 4, the protein and mRNA expression levels of Runx2, Sox9, and Col Ⅹwere found to be dose-dependent as a result of the exposure to T-2 toxin. A concentration of 1 μM. BGJ398 significantly upregulated the gene expression levels. Consequently, the FGFR3 inhibitor elicited an upregulation of genes associated with differentiation in hypertrophic chondrocytes that had been damaged by T-2 toxin induction.

Figure 4.

Expression of differentiation genes in hypertrophic chondrocyte treated with T-2 toxin and BGJ398. (a) mRNA expression of differentiation genes, including Runx2, Sox9, and Col Ⅹ; (b) Protein expression of Runx2, Sox9, and Col Ⅹ. (n = 3, *p < .05 versus 0 ng/mL T-2 toxin group; #p < .05 versus the same T-2 toxin dose. Results are normalized according to GAPDH).

Reduction of ECM degradation-related genes in damaged hypertrophic chondrocytes after treatment with FGFR3 inhibitor

To understand the function of FGFR3 throughout KBD, we also evaluated the expression of ECM degradation-related genes in damaged hypertrophic chondrocytes after BGJ398 treatment. MMP-1, MMP-9, MMP-13, and Col Ⅱ were selected as markers of ECM degradation. As displayed in Figure 5(a), upon exposure to T-2 toxin, there was a dose-dependent increase in the mRNA expression levels of MMP-1, MMP-9, and MMP-13, which was observed to be significantly reduced via 1 μM BGJ398. Similarly, the exposure to T-2 toxin resulted in an increase in the protein expression levels of MMP-13, whereas a reduction of 1 μM BGJ398 was observed (Figure 5(b)). Additionally, exposure to T-2 toxin led to a dose-dependent under-expression of both Col II protein and mRNA in hypertrophic chondrocytes. Conversely, treatment with BGJ398 was observed to increase Col II protein and mRNA expression levels (Figure 5(b)). Thus, the FGFR3 inhibitor reduced T-2 toxin-activation ECM deterioration in damaged hypertrophic chondrocytes.

Figure 5.

Expression ECM degradation genes in hypertrophic chondrocyte treated with T-2 toxin and BGJ398. (a) mRNA expression of differentiation genes, including MMP-1, MMP-9, MMP-13 and Col Ⅱ; (b) Protein expression of MMP-13 and Col Ⅱ. (n = 3, *p < .05 versus 0 ng/mL T-2 toxin group; #p < .05 versus the same T-2 toxin dose. Results are normalized according to GAPDH.

FGFR3 inhibitor prevents the death of hypertrophic chondrocytes promoted by T-2 toxin

For examining the potential involvement of FGFR3 within the process of hypertrophic chondrocytes death induced by T-2 toxin, the annexin V/PI double staining assay was utilized to detect the hypertrophic chondrocytes (Figure 6).

Figure 6.

Annexin V/PI double staining assay of hypertrophic chondrocytes treated with T-2 toxin and BGJ398. (a) The histograms represented the detection of green (Annexin-V) and red (PI) fluorescence; (b) Percentage of cell death (I), early apoptosis (II), late (III) apoptosis and necrosis (IV) in hypertrophic chondrocytes. (n = 3, *p < .001 versus 0 ng/mL T-2 toxin group; #p < .001 versus the same T-2 toxin dose. DMSO: dimethyl sulfoxide).

Figure 6(a) is a scatter plot of fluorescence intensity. The scatter plots in the first row showed the death of hypertrophic chondrocytes which underwent treatment via 0 ng/mL, 10 ng/mL, 25 ng/mL, 50 ng/mL T-2 toxin. The second row of the experiment involved the death of hypertrophic chondrocytes that were subjected to BGJ398 treatment along with varying levels of T-2 toxin. As shown in the first scatter plot, Q1 area is Annexin V-PI + for necrotic cells; Q2 is Annexin V+/PI + for late apoptotic; Q3 is Annexin V-/PI- for living cells; Q4 is Annexin V+/PI- for early apoptotic cells.

Figure 6(b) shows cell death percentage. As depicted in Figure 6(b)-I, the presence of T-2 toxin led to a significant rise in the proportion of deceased hypertrophic chondrocytes at concentrations of 25 ng/mL and 50 ng/mL as compared to the control group (19.18 ± 0.21% vs. 16.84 ± 0.36%, p = .0006; 21.70 ± 1.55% vs. 16.84 ± 0.36%, p = .006) while reduced by 1 μM BGJ398 (25 ng/mL, 17.35 ± 0.31% vs. 19.18 ± 0.21%, p = .001; 50 ng/mL, 18.22 ± 1.33% vs. 21.70 ± 1.55%, p = .042). Dead cells included the presence of early apoptotic cells, late apoptotic cells and necrotic cells. At a concentration of 25 ng/mL of T-2 toxin, there was a notable increase in early apoptosis of hypertrophic chondrocytes (15.60 ± 0.25% vs. 13.42 ± 0.62%, p = .0003). BGJ398 reduced the rate of early apoptosis induced by 25 ng/mL T-2 toxin (13.82 ± 0.07% vs. 15.60 ± 0.25%, p = .0003). T-2 toxin mostly increased the percentage of necrosis of hypertrophic chondrocytes at the concentration of 50 ng/mL (1.65 ± 0.06% vs. 1.13 ± 0.07%, p = .0006), while BGJ398 reduced the necrosis rate of hypertrophic chondrocytes (1.02 ± 0.07% vs. 1.65 ± 0.06%, p = .0003).

Altogether, different levels of T-2 toxin could promote the early apoptosis and necrosis of hypertrophic chondrocytes. Moreover, the inhibition of FGFR3 has the potential to prevent the onset of early apoptosis and necrosis that may be promoted by different T-2 toxin concentrations.

Discussion

The proper development and homeostasis of cartilage necessitates the regulation of FGF signaling. ¹⁶ Aberrant FGF signaling can lead to joint dysplasia as well as the progression of osteoarthritis. In human, FGFR3 belongs to the family of receptor tyrosine kinases that spans the membrane and functions as a high-affinity receptor for various fibroblast growth factors. FGFRs are validated in the development of various tissues, especially the skeletal system. ¹⁷ In our previous studies, the finger joints of children diagnosed with KBD were found to exhibit overexpression of FGFR3. ¹⁰ In this study, overexpression of FGFR3 was detected in both T-2-toxin-treated rats and epiphyseal growth plates (Figure 2). Therefore, the overexpression of FGFR3 may have a significant impact on the development of KBD.

For assessing whether FGFR3 affected differentiation-related genes stimulated by the suspected etiologic element, 1 μM BGJ398 was selected to inhibit FGFR3 signaling prior to T-2 toxin stimulation (Figure 3). The expression of Runx2 occurs during the advanced condensation phase of chondrogenesis, and it experiences a significant reduction in chondrocytes that are undergoing proliferation. However, an upregulation of the gene expression has been observed in chondrocytes that have progressed to the prehypertrophic and hypertrophic stages. Transgenic expression of a dominant-negative variant of Runx2 may inhibit the hypertrophy of all chondrocytes. The gene Runx2 played a pivotal role in the differentiation process of hypertrophic chondrocytes. SOX9, a transcription factor, is widely recognized to possess a substantial influence on every stage of the chondrocyte lineage, encompassing the early condensation phase in addition to the process of chondrocyte proliferation, there is also the transformation of these cells into hypertrophic chondrocytes. ¹⁸ Col Ⅹ is produced through hypertrophic chondrocyte activity. ¹⁵ Through the current investigation, T-2 toxin decreased Runx2, SOX9, and Col Ⅹ expressions at the levels of mRNA and protein, while these changes can be inhibited by FGFR3 inhibitor (Figure 4). FGF signaling through FGFR3 inhibits proliferation, partly due to the Janus kinase–signal transducer and the transcription-1 activator (JAK–STAT1) pathway. ¹⁹ Knockout of Fgfr3 in mice provided an elevated level of chondrocyte proliferation and extension of the length of chondrocyte columns.^20,21 Research on bone explants has indicated that the signaling of FGF, dependent on the effects on PTHrP and Wnt/β-catenin signals, ²² accelerates the terminal differentiation of hypertrophic chondrocytes. We found that overexpression of FGFR3 blocks the differentiation of hypertrophic chondrocytes and involves abnormal differentiation in damaged hypertrophic chondrocytes.

The pathological characteristics of KBD illustrated an altered cartilage matrix metabolism in hypertrophic cartilage. Our previous study reveals that Col Ⅱ is downregulated in patients with KBD, in contrast, MMPs exhibit an opposite pattern. ⁷ As displayed in Figure 5, MMP-1, -9, and -13 have been overexpressed in T-2 toxin-activated hypertrophic chondrocytes, while FGFR3 inhibitor reduced the MMP-1, -9, and -13 overexpression. In contrast to other MMPs, MMP-13 exhibits a more limited expression pattern primarily within connective tissues, and specifically targets collagen type Ⅱ within cartilage for deterioration. ²³ Thus, the evaluation of both mRNA and protein expressions of MMP-13 was conducted. Additionally, T-2 toxin-induced Col Ⅱ expression was increased upon exposure to FGFR3-specific suppressors in the hypertrophic chondrocytes, implying that upregulation of FGFR3-promoted cartilage deterioration was due to T-2 toxin-elevated MMPs and -lowered Col II. Based on these results, the upregulation of FGFR3 has the potential to initiate and speed up the degenerative process in KBD. The delay of the degenerative process in KBD can be achieved by suppressing the operation of FGFR3 signaling in hypertrophic cartilage.

Throughout this study, T-2 toxin increased early apoptosis at 25 ng/mL and necrosis at 50 ng/mL in hypertrophic chondrocytes (Figure 6). T-2 toxin at high concentrations could lead to chondrocyte necrosis instead of apoptosis in hypertrophic chondrocytes. Similarly, according to children diagnosed with KBD, necrosis develops within the profound stratum of the cartilage as a direct consequence of being exposed to T-2 toxin originating from the bone marrow, while apoptosis occurs within the intermediate region of the neighboring necrosis area originating from cartilage due to a reduction in T-2 toxin levels. ²⁴ T-2 toxin can induce associated Wnt/β-catenin signaling chondrocytes apoptosis, ²⁵ insulin-like growth factor-1 receptor, ²⁶ and stress of endoplasmic reticulum. ²⁷ Throughout the current investigation, the percentage of apoptosis or necrosis was reduced within T-2 toxin-activated hypertrophic chondrocytes levels exposed to FGFR3 inhibitor (Figure 6). Hypertrophic chondrocytes were exposed to FGFR3 inhibitor before incubation at different T-2 toxin concentrations. Thus, FGFR3 modulates both chondrocytes apoptosis and necrosis induced by the T-2 toxin. The FGFR3 suppressor prevents hypertrophic chondrocytes death stimulated by the T-2 toxin.

In conclusion, overexpression of FGFR3 contributes to the pathological development of KBD, while inhibiting FGFR3 signaling could alleviate ECM deterioration, abnormal differentiation of chondrocytes, and excessive cell death in hypertrophic chondrocytes induced by T-2 toxin. In subsequent times, animal research projects will be formulated with the aim of corroborating the mechanism of FGFR3 in KBD. The objective of this study is to determine potential therapeutic targets for KBD.

Supplemental Material

Supplemental Material - Increased FGFR3 is involved in T-2 toxin-induced lesions of hypertrophic cartilage associated with endemic osteoarthritis

Supplemental Material for Increased FGFR3 is involved in T-2 toxin-induced lesions of hypertrophic cartilage associated with endemic osteoarthritis by Ying Zhang Qian Fang, Yinan Liu, Dan Zhang, Ying He, Fei Liu, Kun Sun and Jinghong Chen in Human & Experimental Toxicology.