Effect of total flavonoids of Rhizoma Drynariae in thiram induced cytotoxicity of chondrocyte via BMP-2/Runx2 and IHH/PTHrP expressions

Molecular mechanisms of environmental pollutant-induced cartilage damage: from developmental disorders to osteoarthritis

The objective of the present study was to review the molecular mechanisms of the adverse effects of environmental pollutants on chondrocytes and extracellular matrix (ECM). Existing data demonstrate that both heavy metals, including cadmium (Cd), lead (Pb), and arsenic (As), as well as organic pollutants, including polychlorinated dioxins and furans (PCDD/Fs) and polychlorinated biphenyls (PCB), bisphenol A, phthalates, polycyclic aromatic hydrocarbons (PAH), pesticides, and certain other organic pollutants that target cartilage ontogeny and functioning. Overall, environmental pollutants reduce chondrocyte viability through the induction apoptosis, senescence, and inflammatory response, resulting in cell death and impaired ECM production. The effects of organic pollutants on chondrocyte development and viability were shown to be mediated by binding to the aryl hydrocarbon receptor (AhR) signaling and modulation of non-coding RNA expression. Adverse effects of pollutant exposures were observed in articular and growth plate chondrocytes. These mechanisms also damage chondrocyte precursors and subsequently hinder cartilage development. In addition, pollutant exposure was shown to impair chondrogenesis by inhibiting the expression of Sox9 and other regulators. Along with altered Runx2 signaling, these effects also contribute to impaired chondrocyte hypertrophy and chondrocyte-to-osteoblast trans-differentiation, resulting in altered endochondral ossification. Several organic pollutants including PCDD/Fs, PCBs and PAHs, were shown to induce transgenerational adverse effects on cartilage development and the resulting skeletal deformities. Despite of epidemiological evidence linking human environmental pollutant exposure to osteoarthritis or other cartilage pathologies, the data on the molecular mechanisms of adverse effects of environmental pollutant exposure on cartilage tissue were obtained from studies in laboratory rodents, fish, or cell cultures and should be carefully extrapolated to humans, although they clearly demonstrate that cartilage should be considered a putative target for environmental pollutant toxicity.

Transcriptome analysis reveals the pathogenesis of spontaneous tibial dyschondroplasia in broilers

Tibial dyschondroplasia (TD) is a severe bone disease that affects fast-growing broiler chickens and causes economic loss. Despite previous studies, the regulatory mechanism of TD remains unclear and is thought to be primarily based on thiram induction, which may differ from that of naturally occurring diseases. To better understand TD, a digital X-ray machine was used in the present study to determine its incidence in four hundred yellow-feathered broiler chickens. The results showed that the incidence of TD was 22% after 6 weeks and gradually decreased after 8 and 10 weeks. The body weight of broilers with TD decreased significantly compared to that of NTD broilers. In addition, the length and density of the tibia were reduced after eight and 10 weeks, and the density of the tibia was reduced after 6 weeks compared with the NTD chickens. This study also examined tibial quality parameters from TD (n = 12) and NTD broilers (n = 12) and found that bone mineral content, bone mineral density, bone ash content, calcium content, and phosphorus content were significantly reduced in TD broilers. Transcriptome analysis revealed 849 differentially expressed genes (DEGs) in the growth plate between TD (n = 6) and NTD groups (n = 6). These genes were enriched in ECM-receptor interaction, cytokine-cytokine receptor interaction, calcium signaling pathway, and TGF-β signaling. Genes encoding the alpha chain of type XII collagen, that is, COL1A1, COL5A1, and COL8A1) were identified as critical in the regulatory network of TD. Gene set enrichment analysis (GSEA) revealed that the pathways of cartilage development, circulatory system development, and nervous system development were changed in the growth plates of TD birds. In the blood transcriptome, 12 DEGs were found in TD (n = 4) and NTD chickens (n = 4), and GSEA revealed that the pathways from TD broilers' blood related to the phagosome, linoleic acid metabolism, monoatomic ion homeostasis, and calcium ion transport were downregulated. This study provides a comprehensive understanding of TD, including its effects on tibial quality, tibial changes, and the circulatory system, along with identifying important genes that may lead to the development of TD.

Modulation of apoptosis and Inflammasome activation in chondrocytes: co-regulatory role of Chlorogenic acid

BACKGROUND

The B-cell lymphoma 2 (Bcl-2) protein regulates programmed cell death throughout the disease conditions by upholding apoptotic pathways. However, the mechanism by which it's expressed in chondrocytes still needs to be studied in chondrocyte-related disorders. Additionally, exploring the potential therapeutic role of Chlorogenic acid (CGA) in confluence with Bcl-2 modulation is of significant interest.

METHODS

In vivo and in vitro studies were performed according to our previous methodologies. The chondrocytes were cultured in specific growth media under standard conditions after expression verification of different microRNAs through high-throughput sequencing and verification of Bcl-2 involvement in tibial growth plates. The effect of Bcl-2 expression was investigated by transfecting chondrocytes with miR-460a, siRNA, and their negative controls alone or in combination with CGA. The RNA was extracted and subjected to a reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Western blot analysis and immunofluorescence assays were performed to visualize the intracellular localization of Bcl-2 and associated proteins related to apoptotic and inflammasome pathways. Moreover, apoptosis through flow cytometry was also performed to understand the modulation of concerning pathways.

RESULTS

The suppression of Bcl-2 induced higher apoptosis and mitochondrial dysfunction, leading to IL-1β maturation and affecting the inflammasome during chondrocyte proliferation. Conversely, overexpression attenuated the activation, as evidenced by reduced caspase activity and IL-1β maturation. In parallel, CGA successfully reduced siRNA-induced apoptosis by decreasing Cytochrome C (Cyto C) release from the mitochondria to the cytoplasm, which in turn decreased Caspase-3 and Caspase-7 cleavage with Bcl-2-associated X protein (Bax). Furthermore, siBcl-2 transfection and CGA therapy increased chondrocyte proliferation and survival. The CGA also showed a promising approach to maintaining chondrocyte viability by inhibiting siRNA-induced apoptosis.

CONCLUSIONS

Targeting Bcl-2-mediated regulation might be a possible treatment for chondrocyte-related conditions. Moreover, these results add knowledge of the complicated processes underlying chondrocyte function and the pathophysiology of related diseases, highlighting the significance of target specific therapies. Video Abstract.

Hsa-miR-15b-5p/miR-195-5p Controls Osteogenic Differentiation of Human Adipose-Derived Mesenchymal Stem Cells Through Regulating Indian Hedgehog Expression

Osteoblastogenesis is regulated by several signaling pathways like hedgehog signaling. Of three types of mammalian Hedgehog genes, the Indian Hedgehog (Ihh) plays an important role in the formation of the skeleton. Mesenchymal stem cells (MSCs) isolated from adipose tissue have been considered a good source of osteoblast differentiation. Evidence also suggests that miRNAs play an important role in regulating key stages of osteoblast differentiation. In this study, two miRNAs targeting the Ihh were predicted by using bioinformatics analysis. ASCs were successfully derived, purified, and characterized from human adipose tissue. ASCs were chemically induced into osteoblast cells. Then, differentiation was confirmed by alkaline phosphatase (ALP) activity and Alizarin red staining. The relative expression of Ihh and related miRNAs was evaluated after 0, 7, 14, and 21 from the differentiation duration. The results of bioinformatics data showed that has-miR-195-5p and has-miR-15b-5p target the Ihh gene. The expression of Ihh significantly increased in a time-dependent manner in the differentiation process. In contrast, miR-195-5p and miR-15b-5p were significantly downregulated dependent on time duration (P < 0.01). Overall, the data indicate the antithetical regulation of Ihh versus has-miR-195-5p and has-miR-15b-5p during the differentiation process. These results support the hypothesis that these mi-RNAs could target the Ihh in the pathway of osteoblast differentiation derived from human ASCs.

Effect of hexavalent chromium on growth performance and metabolism in broiler chicken

Hexavalent chromium Cr (VI) is one of the most hazardous heavy metals in the environment and is toxic to living organisms causing tissue damage, disruption of the intestinal microbiota and cancer. However, there is little information on the relationship between the Cr (VI) and broiler chickens. The current study was performed to investigate the effect of Cr (VI) on growth performance, serum biochemical analysis, histopathological observations, and metabolomics analysis in broilers. Results show that Cr (VI) exposure significantly decreased the body weight (p < 0.01) and caused liver damages in broilers. With the extension of Cr (VI) action time, the liver appeared obvious pathological changes, including hepatic cord disorder, incomplete hepatocyte additionally, decreased serum biochemical indices of calcium (Ca), phosphorus (P), total protein (TP), phosphatase (ALP), and globin (GLB) significantly (p < 0.01). Moreover, metabolomics analysis indicated that 29 differential metabolites were identified, such as phytosphingosine, L-Serine, 12, 13-DHOME, Alpha-dimorphecolic acid, L-Methionine, L-Phenylalanine, 3-Dehydroshikimate, L-Tyrosine, and N-Acetyl-L-phenylalanine were significantly decreased under the action of Cr (VI) (p < 0.05). These 29 differential metabolites are mainly involved in 35 metabolic pathways, such as aminoacyl-tRNA biosynthesis, phenylalanine metabolism, sphingolipid, and linoleic metabolism. The study revealed that exposure to Cr (VI) resulted in a decrease in growth performance and metabolism, with the hazards and toxicity in broiler chicken. The findings provided new insight and a comprehensive understanding of the relationship between Cr (VI) and broiler chickens.

The Effect of miR-140-5p with HDAC4 towards Growth and Differentiation Signaling of Chondrocytes in Thiram-Induced Tibial Dyschondroplasia

There is evidence to suggest that microRNA-140-5p (miR-140), which acts as a suppressor, is often elevated and has a role in various malignancies. Nevertheless, neither the function nor the mechanisms in chondrocytes linked with bone disorders, e.g., tibial dyschondroplasia (TD), have been satisfactorily established. The purpose of this study was to look into the role of microRNA-140-5p (miR-140) and its interaction with HDAC4 in chondrocytes, as well as the implications for tibial dyschondroplasia (TD), with a particular focus on the relationship between low miR-140 expression and poor pathologic characteristics, as well as its physiological effects on chondrocyte growth, differentiation, and chondrodysplasia. In this investigation, we discovered that TD had a reduced expression level of the miR-140. There was a correlation between low miR-140 expression, poor pathologic characteristics, and the short overall survival of chondrocytes. Our findings show an aberrant reduction in miR-140 expression, and HDAC4 overexpression caused disengagement in resting and proliferation zones. This further resulted in uncontrolled cell proliferation, differentiation, and chondrodysplasia. Mechanistically, HDAC4 inhibited the downstream transcription factors MEF2C and Runx2 and interacted with Col-Ⅱ, Col-X, and COMP. However, miR-140 binding to the 3'-UTR of HDAC4 resulted in the growth and differentiation of chondrocytes. Moreover, the expression of HDAC4 through LMK-235 was significantly decreased, and the expression was significantly increased under ITSA-1, referring to a positive feedback circuit of miR-140 and HDAC4 for endochondral bone ossification. Furthermore, as a prospective treatment, the flavonoids of Rhizoma drynariae (TFRD) therapy increased the expression of miR-140. Compared to the TD group, TFRD treatment increased the expression of growth-promoting and chondrocyte differentiation markers, implying that TFRD can promote chondrocyte proliferation and differentiation in the tibial growth plate. Hence, directing this circuit may represent a promising target for chondrocyte-related bone disorders and all associated pathological bone conditions.

Thiram-induced hyperglycemia causes tibial dyschondroplasia by triggering aberrant ECM remodeling via the gut-pancreas axis in broiler chickens

Pesticide thiram is widely used in agriculture and has been demonstrated to cause tibial dyschondroplasia (TD) in birds. However, the underlying mechanism remains unclear. This work used multi-omics analysis to evaluate the molecular pathways of TD in broilers that were exposed to low level of thiram. Integrative analysis of transcriptomic, proteomic, and metabolomic revealed thiram activity in enhancing pathological ECM remodeling via attenuating the glycolysis pathway and activating the hexosamine and glucuronic acid pathways. Intriguingly, we found hyperglycemia as a crucial factor for ECM overproduction, which resulted in the development of TD. We further demonstrated that high glucose levels are caused by islet secretion dysfunction in thiram-treated broilers. A combination of factors, including lipid disorder, low-grade inflammation, and gut flora disturbance, might contribute to the dysregulation of insulin secretion. The current work revealed the underlying toxicological mechanisms of thiram-induced tibial dyschondroplasia through blood glucose disorder via the gut-pancreas axis in chickens for the first time, which makes it easier to figure out the health risks of pesticides for worldwide policy decisions.

Chlorogenic acid suppresses miR-460a in the regulation of Bcl-2, causing interleukin-1β reduction in thiram exposed chondrocytes via caspase-3/caspase-7 pathway

BACKGROUND

Apoptosis is thought to be involved in all processes, including normal cell cycle, immune system, atrophy, embryonic development, and chemical-induced cellular damage. However, if the normal apoptotic process fails, the results might be disastrous, e.g., chondrocytes damage in tibial dyschondroplasia (TD). TD is a worldwide issue in the poultry sector due to thiram toxicity. Thiram (Tetramethyl thiuram disulfide) is a dithiocarbamate pesticide and fungicide commonly used in horticulture to treat grains meant for seed protection and preservation.

PURPOSE

According to prior studies, chlorogenic acid (CGA) is becoming essential for regulating apoptosis. But still, the specific role of CGA in chondrocyte cells remains unclear. The present study explored the molecular mechanism of CGA on chondrocytes' apoptosis with B-cell lymphoma 2 signaling under the effect of miR-460a.

METHODS

An in vivo and in vitro study was performed according to our previously developed methodology. Flow cytometry, western blotting, reverse transcription-quantitative polymerase chain reaction, and immunofluorescence assay were used to investigate the involvement of apoptosis and inflammasome related pathways.

RESULTS

The CGA decreased the apoptosis rate with the deactivation of miR-460a, accompanied by the activation of Bcl-2. The high expression of miR-460a reduced the cell viability of chondrocytes in vitro and in vivo, that led to the interleukin-1β production. While the apoptotic executioners (caspase-3 and caspase-7) acted upstream in miR-460a overexpressing cells, and its depletion downgraded these executioners. The CGA administrated cells negatively regulated miR-460a expression and thus indicating the deactivation of the apoptotic and inflammasome related pathways.

CONCLUSION

Chlorogenic acid had a negative effect on miR-460a, setting off specific feedback to regulate apoptotic and inflammasome pathways, which might be a key feature for chondrocytes' survival.

Thiram exposure in environment: A critical review on cytotoxicity

Thiram is used in large quantities in agriculture and may contaminate the environment by improper handling or storage in chemical plants and warehouses. A review of the literature has shown that thiram can affect different organs in animals and its toxic mechanisms can be elucidated in more detail at molecular level. We have summarized several impacts of thiram on animals: the effects of the perspectives of oxidative stress, mitochondrial damage, autophagy, apoptosis, and the IHH/PTHrP pathway on regulating abnormal skeletal development in particular tibial dyschondroplasia and kyphosis; angiogenesis inhibition was investigated from the perspective of angiogenesis factor inhibition, PI3K/AKT signaling pathway and CD147; the inhibition effect of thiram on fibroblasts and erythrocytes via the perspective of oxidative stress, mitochondrial damage and inhibition of growth factors in animal skin fibroblasts and erythrocytes; studied fertilized egg size, reduced fertility, neurodegeneration, and immune damage from the perspectives of CYP51 inhibition and dopamine-b-hydroxylase inhibition in the reproductive system, vitamin D deficiency in the nervous system, and inflammatory damage in the immune system; embryonic dysplasia in terms of thyroid hormone repression in animal embryonic development and repression of the SOX9a transcription factor. The elucidation of the mechanisms of toxicity of thiram on various organs of animals at molecular level will enable a more detailed understanding of the mechanisms of toxicity of thiram in animals and will facilitate the exploration of the treatment of thiram poisoning at molecular level.

Total flavonoids of Rhizoma Drynariae protect hepatocytes against aflatoxin B1-induced oxidative stress and apoptosis in broiler chickens

Aflatoxin B1 (AFB1) is a common mycotoxin in food and in the environment that lead to multi-organ injury in humans and animals. The objective of this study was to evaluate the detoxification properties of dietary total flavonoids of Rhizoma drynariae (TFRD), a Chinese herbal, on aflatoxin B1 (AFB1)-induced hepatic oxidative damage and apoptosis of liver of broiler chickens. A total of 160 healthy specific pathogen free (SPF) 21-day-old broilers were randomly allocated to 4 groups, including the CON group (basal diet), TFRD group (basal diet with 125 mg/kg TFRD), AFB1 group (100 μg/kg body weight), and AFB1 (100 μg/kg body weight) + TFRD (basal diet with 125 mg/kg TFRD) group. The exposure of AFB1 continued for seven days. The results showed that TFRD treatment alleviated the abnormal changes of growth performance and liver morphology, reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. Moreover, TFRD promoted the antioxidant capacity of serum, increased the activities of total superoxide dismutase (T-SOD), oxidized glutathione (GSSG) and glutathione (GSH) (p < 0.05), while decreased MDA contents (p > 0.05). Meanwhile, supplementation of TFRD significantly increased the expression of antioxidant-related genes (SOD, CAT, GST, and GPX1) in liver (p < 0.05). Furthermore, we found that AFB1 was involved in the regulation of PI3K/AKT signaling pathway, leading to hepatocyte apoptosis. At the same time, TFRD treatment inhibited AFB1-induced apoptosis and significantly changed mRNA expression of apoptosis-related genes, including PI3K, AKT, Bax, and Bcl-2 (p < 0.05). The results indicated that TFRD could alleviate AFB1-induced liver injury in broiler chickens.

Chlorogenic acid suppresses mitochondrial apoptotic effectors Bax/Bak to counteract Nod-like receptor pyrin domain 3 (NLRP3) inflammasome in thiram exposed chondrocytes

BACKGROUND

Tibial dyschondroplasia (TD) is a common disease characterized by proliferation and the deterioration of growth plate's chondrocytes due to widespread utilization of thiram in the agriculture and industrial sector.

PURPOSE

In recent years, Nod-like receptor pyrin domain 3 (NLRP3) inflammasome has become a dilemma in the occurrence of many diseases. According to many research investigations, NLRP3 inflammasome has been linked to various diseases caused by pesticides and environmental toxins. Its involvement in such conditions opens up new treatment approaches. However, the role of the NLRP3 inflammasome in the development of TD is not fully understood under the impact of chlorogenic acid (CGA).

METHODS

Chondrocytes were cultured with our previously developed methodology from growth plates. After morphological and molecular identification, chondrocytes were split into different groups to investigate the efficacy of chlorogenic acid. Cell apoptosis was determined through flow cytometry and Tunnel assay. Furthermore, RT-qPCR, immunofluorescence, and western blotting techniques were used to check marker genes and proteins expression.

RESULTS

In thiram-induced TD, Bax/Bak activation persuade a parallel pathway, mediated by the NLRP3 base inflammasome. It is worth mentioning that the apoptotic executioners (caspase-3 and caspase-7) act upstream for inflammasome. Furthermore, chondrocytes' ability to undergo mitochondrial apoptosis was governed by anti-apoptotic members, e.g., Bcl-2 and Bcl-xl. Equilibrium of these anti-apoptotic proteins ensured appropriate regulation of apoptosis during the development and survival of chondrocytes.

CONCLUSION

Chondrocytes have ability to undergo Bax/Bak-mediated apoptosis and generate pro-inflammatory signals, e.g., NLRP3 in thiram-induced TD. So, the Nod-like receptor pyrin domain 3 is the potential target to eliminate TD at all stages of pathology, while drugs, e.g., CGA, can significantly improve chondrocytes' survival by targeting these pro-inflammatory signals.

Taurine is an effective therapy against thiram induced tibial dyschondroplasia via HIF-1α/VEGFA and β-catenin/ GSK-3β pathways in broilers

Thiram causes tibial dyschondroplasia in broilers, leading to a significant economic loss in the poultry industry. Our study explored the effects of taurine in thiram induced tibial dyschondroplasia (TD) through in vivo and in vitro approches. In in vivo study, thiram resulted in lameness disorder, low production parameters ALP, ACP, and a high level of NOS. While, the taurine exhibited promising effect by reducing lameness, increasing ALP, ACP levels, and significantly lowering NOS level with the restoration of the growth plate. In in vitro study, thiram caused distortion and disintegration of chondrocytes. The CCK-8 technique revealed the lower cell activity in TD as compared with the treatment group. Even, the treatment and taurine groups had higher cell activity than control group. Also, the chondrocyte morphology progressively reverted to normal after taurine treatment. It might effectively decreased the symptoms of TD in broilers and their production performance. Further research found that the taurine effectively improved chondrocytes' cell viability and recovered lameness disorder by regulation of HIF-1α, VEGFA, and Wnt/β-catenin signaling pathways. In summary, these results indicate that taurine has a protective effect on thiram-induced broilers and it can enhance the growth activity by directly affecting the development of chondrocytes and blood vessels.

Long-term exposure to the fluoride blocks the development of chondrocytes in the ducks: The molecular mechanism of fluoride regulating autophagy and apoptosis

Long-term exposure to excessive fluoride causes chronic damage in the body tissues and could lead to skeletal and dental fluorosis. Cartilage damage caused by excessive fluoride intake has gained wide attention, but how fluoride accumulation blocks the development of chondrocytes is still unclear. Here, we report a negative correlation between the length and growth plate width after NaF treatments via apoptosis and autophagy, with shrinkage of cells, nuclear retraction, dissolution of chondrocytes. Whereas, fluoride exposure had no significant effect on the number and distribution of the osteoclasts which were well aligned. More importantly, fluoride exposure induced apoptosis of tibial bone through CytC/Bcl-2/P53 pathways via targeting Caspase3, Caspase9, Bak1, and Bax expressions. Meanwhile, the Beclin1, mTOR, Pakin, Pink, and p62 were elevated in NaF treatment group, which indicated that long-term excessive fluoride triggered the autophagy in the tibial bone and produced the chondrocyte injury. Altogether, fluoride exposure induced the chondrocyte injury by regulating the autophagy and apoptosis in the tibial bone of ducks, which demonstrates that fluoride exposure is a risk factor for cartilage development. These findings revealed the essential role of CytC/Bcl-2/P53 pathways in long-term exposure to fluoride pollution and block the development of chondrocytes in ducks, and CytC/Bcl-2/P53 can be targeted to prevent fluoride induced chondrocyte injury.

Molecular Mechanisms of Chondrocyte Proliferation and Differentiation

Cartilage is a kind of connective tissue that buffers pressure and is essential to protect joint movement. It is difficult to self-recover once cartilage is damaged due to the lack of blood vessels, lymph, and nerve tissues. Repair of cartilage injury is mainly achieved by stimulating chondrocyte proliferation and extracellular matrix (ECM) synthesis. Cartilage homeostasis involves the regulation of multiple growth factors and the transduction of cellular signals. It is a very complicated process that has not been elucidated in detail. In this review, we summarized a variety of signaling molecules related to chondrocytes function. Especially, we described the correlation between chondrocyte-specific regulatory factors and cell signaling molecules. It has potential significance for guiding the treatment of cartilage injury.

Cluster of differentiation 147 (CD147) expression is linked with thiram induced chondrocyte's apoptosis via Bcl-2/Bax/Caspase-3 signalling in tibial growth plate under chlorogenic acid repercussion

Tibial dyschondroplasia (TD) is a metabolic disease of young poultry that affects bone andcartilage's growth. It mostly occurs in broilers due to thiram toxicity in the feed. In this disease, tibial cartilage is not yet ripe for ossification, but it also results in lameness, death, and moral convictions of commercial poultry due to numerous apoptotic changes on cell level. These changes serve a cardinal role in this situation. Many potential problems indicate that chlorogenic acid (CGA) performs an extensive role in controlling apoptosis's perception. However, the actual role of CGA in TD affected chondrocytes in-vitro is still unidentified. The current study investigates the imperceptible insight of CGA on chondrocyte's apoptosis via B-cell lymphoma 2 (Bcl-2), Bcl-2 associated x-protein (Bax), and Caspase-3 with CD147 signalling. The expression of these markers was investigated by Immunofluorescence, western blot analysis, and reverse transcription-quantitative polymerase chain (RT-qPCR). Chondrocytes from the growth plate of tibia were isolated, cultured, and processed. A sub-lethal thiram (2.5 μg/mL) was used to induce cytotoxicity and then treated with an optimum dose (40 μg/ mL) of CGA. According to the results, thiram distorted chondrocyte cells with enhanced apoptotic rate. But, in case of CGA, high expression of CD147 enhanced cell viability of chondrocytes, accompanied by downregulation of Bax/Caspase-3 signalling with the upregulation of Bcl-2. The first possibility has ruled out in the present study by the observation that the cells apoptosis marker, Caspase-3 showed a significant change in CD147 overexpressing cells. Conversely, immunodepletion of CD147 with enhanced cleavage of Caspase-3, indicating the activation of apoptosis in chondrocytes cells. Therefore, these findings suggest a novel insight about CD147 in thiram induced TD about the regulation of Bcl-2/Bax/Caspase-3 apoptosis-signalling axis.

Rhizoma drynariae total flavonoids inhibit the inflammatory response and matrix degeneration via MAPK pathway in a rat degenerative cervical intervertebral disc model

Rhizoma drynariae total flavonoids (RDTF) are extracted from Drynaria fortunei J. Sm (D. fortunei), which was a Chinese herb commonly used to treat fractures and bruises. Modern pharmacological studies indicate flavonoids have anti-inflammatory effect in clinical practice. However, its active ingredients and the mechanisms of action are far from clear. The present study aims to determine whether RDTF can protect against intervertebral disc degeneration in a rat cervical intervertebral disc model and investigate the associated molecular mechanisms. Sprague Dawley (SD) rats were randomized into five groups: control group (CG, n = 8), intervertebral disc degeneration group (NG, n = 8), low-dose RDTF-treated group (LG, n = 8), medium-dose RDTF-treated group (MG, n = 8), and high-dose RDTF-treated group (HG, n = 8). Hematoxylin and eosin (HE) staining, immunohistochemistry (IHC), immunofluorescence, ELISA, Western blot and quantitative real time PCR (qRT-PCR) assays were used to investigate inflammatory, catabolic factors and the latent regulatory mechanism of the effects of RDTF on intervertebral disc cells. HE staining showed disc degeneration in all groups except CG, and the function was restored after RDTF treatment. IHC, Western blot, qRT-PCR, immunofluorescence and ELISA results showed that RDTF prevented intervertebral disc degeneration by suppressing mitogen-activated protein kinase (MAPK) pathway, which reduced expression of intracellular matrix metalloproteinases (MMPs), such MMP3, MMP13, and inflammatory factors including interleukin-1β (IL-1β), tumour necrosis factor-α (TNF-α). Notably RDTF inhibited extracellular matrix (ECM) degeneration by increasing expression of aggrecan and collagen type II and preventing the upregulation of collagen type I and III. It suggests that RDTF has a potential therapeutic effect on cervical spondylosis.