Molecular mechanism of miR-203a targeting Runx2 to regulate thiram induced-chondrocyte development.

Thiram is a kind of organic compound, which is commonly used for sterilization, insecticidal and deodorization in daily life. Its toxicology has been broadly studied. Recently, more and more microRNAs have been shown to participate in the regulation of cartilage development. However, the potential mechanism by which microRNA regulates chondrocyte growth is still unclear. Our experiments have demonstrated that thiram can hamper chondrocytes development and cause a significant increase in miR-203a content in vitro and in vivo trials. miR-203a mimic significantly decrease in mRNA and protein expression of Wnt4, Runx2, COL2A1, ß-catenin and ALP, and significantly enhance the mRNA and protein levels of GSK-3ß. It has been observed that overexpression of miR-203a hindered chondrocytes development. In addition, Runx2 was confirmed to be a direct target of miR-203a by dual luciferase report gene assay. Transfection of si-Runx2 into chondrocytes reveals that significant downregulation of genes is associated with cartilage development. Overall, these results suggest that overexpression of miR-203a inhibits the expression of Runx2. These findings are conducive to elucidate the mechanism of chondrocytes dysplasia induced by thiram and provide new research ideas for the toxicology of thiram.

miR-181b-1-3p affects the proliferation and differentiation of chondrocytes in TD broilers through the WIF1/Wnt/ß-catenin pathway.

Thiram is a plant fungicide, its excessive use has exceeded the required environmental standards. It causes tibial dyschondroplasia (TD) in broilers which is a common metabolic disease that affects the growth plate of tibia bone. It has been studied that many microRNAs (miRNAs) are involved in the differentiation of chondrocytes however, their specific roles and mechanisms have not been fully investigated. The selected features of tibial chondrocytes of broilers were studied in this experiment which included the expression of miR-181b-1-3p and the genes related to WIF1/Wnt/ß-catenin pathway in chondrocytes through qRT-PCR, western blot and immunofluorescence. The correlation between miR-181b-1-3p and WIF1 was determined by dual luciferase reporter gene assay whereas, the role of miR-181b-1-3p and WIF1/Wnt/ß-catenin in chondrocyte differentiation was determined by mimics and inhibitor transfection experiments. Results revealed that thiram exposure resulted in decreased expression of miR-181b-1-3p and increased expression of WIF1 in chondrocytes. A negative correlation was also observed between miR-181b-1-3p and WIF1. After overexpression of miR-181b-1-3p, the expression of ACAN, ß-catenin and Col2a1 increased but the expression of GSK-3ß decreased. It was observed that inhibition of WIF1 increased the expression of ALP, ß-catenin, Col2a1 and ACAN but decreased the expression of GSK-3ß. It is concluded that miR-181b-1-3p can reverse the inhibitory effect of thiram on cartilage proliferation and differentiation by inhibiting WIF1 expression and activating Wnt/ß-catenin signaling pathway. This study provides a new molecular target for the early diagnosis and possible treatment of TD in broilers.

Research progress on the protective effects of licorice-derived 18ß-glycyrrhetinic acid against liver injury.

The first description of the medical use of licorice appeared in "Shennong Bencao Jing", one of the well-known Chinese herbal medicine classic books dated back to 220-280 AD. As one of the most commonly prescribed Chinese herbal medicine, licorice is known as "Guo Lao", meaning "a national treasure" in China. Modern pharmacological investigations have confirmed that licorice possesses a number of biological activities, such as antioxidation, anti-inflammatory, antiviral, immune regulation, and liver protection. 18ß-glycyrrhetinic acid is one of the most extensively studied active integrants of licorice. Here, we provide an overview of the protective effects of 18ß-glycyrrhetinic acid against various acute and chronic liver diseases observed in experimental models, and summarize its pharmacological effects and potential toxic/side effects at higher doses. We also make additional comments on the important areas that may warrant further research to support appropriate clinical applications of 18ß-glycyrrhetinic acid and avoid potential risks.

A new recombinant MS-superoxide dismutase alleviates 5-fluorouracil-induced intestinal mucositis in mice.

Intestinal mucositis is a common side effect of anticancer regimens that exerts a negative impact on chemotherapy. Superoxide dismutase (SOD) is a potential therapy for mucositis but efficient product is not available because the enzyme is degraded following oral administration or induces an immune reaction after intravascular infusion. Multi-modified Stable Anti-Oxidant Enzymes® (MS-AOE®) is a new recombinant SOD with better resistance to pepsin and trypsin. We referred it as MS-SOD to distinguish from other SODs. In this study we investigated its potential to alleviate 5-FU-induced intestinal injury and the mechanisms. An intestinal mucositis model was established in C57/BL6 mice by 5-day administration of 5-FU (50 mg/kg every day, ip). MS-SOD (800 IU/10 g, ig) was given once daily for 9 days. 5-FU caused severe mucositis with intestinal morphological damage, bodyweight loss and diarrhea; MS-SOD significantly decreased the severity. 5-FU markedly increased reactive oxygen species (ROS) and inflammatory cytokines in the intestine which were ameliorated by MS-SOD. Furthermore, MS-SOD modified intestinal microbes, particularly reduced Verrucomicrobia, compared with the 5-FU group. In Caco2 cells, MS-SOD (250-1000 U/mL) dose-dependently decreased tBHP-induced ROS generation. In RAW264.7 cells, MS-SOD (500 U/mL) had no effect on LPS-induced inflammatory cytokines, but inhibited iNOS expression. These results demonstrate that MS-SOD can scavenge ROS at the initial stage of injury, thus play an indirect role in anti-inflammatory and barrier protein protection. In conclusion, MS-SOD attenuates 5-FU-induced intestinal mucositis by suppressing oxidative stress and inflammation, and influencing microbes. MS-SOD may exert beneficial effect in prevention of intestinal mucositis during chemotherapy in clinic.

18ß-Glycyrrhetinic acid protects against alpha-naphthylisothiocyanate-induced cholestasis through activation of the Sirt1/FXR signaling pathway.

Cholestasis is a common feature of liver injury, which manifests as bile acid excretion and/or enterohepatic circulation disorders. However, very few effective therapies exist for cholestasis. Recently, 18ß-Glycyrrhetinic acid (18b-GA), a major metabolic component of glycyrrhizin, which is the main ingredient of licorice, was reported to protect against alpha-naphthylisothiocyanate (ANIT)-induced cholestasis. However, its protective mechanism remains unclear. We hypothesized that 18b-GA may stimulate the signaling pathway of bile acid (BA) transportation in hepatocytes, resulting its hepatoprotective effect. According to the results, 18b-GA markedly attenuated ANIT-induced liver injury as indicated the hepatic plasma chemistry index and histopathology examination. In addition, the expression levels of nuclear factors, including Sirt1, FXR and Nrf2, and their target efflux transporters in the liver, which mainly mediate bile acid homeostasis in hepatocytes, significantly increased. Furthermore, we first revealed that 18b-GA treatment significantly activated FXR, and which can be significantly reduced by EX-527 (a potent and selective Sirt1 inhibitor), indicating that 18b-GA activates FXR through Sirt1. Taken together, 18b-GA confers hepatoprotection against ANIT-induced cholestasis by activating FXR through Sirt1, which promotes gene expression of the efflux transporter, and consequently attenuates dysregulation of bile acid homeostasis in hepatocyte compartments.

Inhalation of ammonia promotes apoptosis and induces autophagy in hepatocytes via Bax/BCl-2 and m-TOR/ATG5/LC-3bII axes.

Ammonia (NH3) is an irritating gas and atmospheric pollutant that endangers the health of humans and animals by stimulating respiratory tract's mucosa and causing liver damage. However, physiological role of ammonia gas in hepatotoxicity remains unclear. To investigate the hepatotoxic effects of inhaled ammonia gas, experiments were conducted using mouse model exposed to 100 ppm of ammonia gas for 21 days. The exposed mice exhibited signs of depression, emaciation, and reduced growth. This study revealed that inhalation of ammonia led to significant decrease in water (P < 0.0001) and food intake (P < 0.05), resulting in slower growth. Histopathological analysis showed that ammonia stress alters the microstructure of the liver by enlarging the gap between hepatic lobule and fibrosis. Moreover, ammonia-induced stress significantly reduces the expression of the anti-apoptotic protein BCl-2 (P < 0.001), while elevates the mRNA expression of the pro-apoptotic gene Bax (P < 0.001). Furthermore, ammonia inhalation significantly increases the protein expression of LC-3bII (P < 0.05) and the mRNA expression of autophagy-related gene 5 (ATG5) (P < 0.05) and p62 (P < 0.05) while remarkably decreases the mRNA expression of mammalian target of rapamycin (m-TOR) (P < 0.05). In conclusion, this study demonstrates that inhalation of ammonia gas causes liver damage and suggests autophagy happening via m-TOR/p62/LC-3bII and pro-apoptosis effect mediated by Bax/BCl-2 in the liver damage caused by ammonia inhalation. Our study provides a new perspective on ammonia-induced hepatotoxicity.

Crack control optimization of basement concrete structures using the Mask-RCNN and temperature effect analysis.

In order to enhance the mitigation of crack occurrence and propagation within basement concrete structures, this research endeavors to propose an optimization methodology grounded in the Mask Region-based Convolutional Neural Network (Mask-RCNN) and an analysis of temperature effects. Initially, the Mask-RCNN algorithm is employed to perform image segmentation of the basement concrete structure, facilitating the precise identification of crack locations and shapes within the structure. Subsequently, the finite element analysis method is harnessed to simulate the structural stress and deformation in response to temperature variations. An optimization algorithm is introduced to adjust geometric parameters and material properties using insights from the temperature effect analysis. This algorithm aims to minimize stress concentration and deformation within the structure, thus diminishing the incidence and proliferation of cracks. In order to assess the efficacy of the optimization approach, an authentic basement concrete structure is selected for scrutiny, and the structure is monitored in real-time through the installation of strain gauges and monitoring equipment. These instruments track structural stress and deformation under diverse temperature conditions, and the evolution of cracks is meticulously documented. The outcomes demonstrate that by adjusting the structural geometric parameters and material properties, the crack density experiences a notable reduction of 60.22%. Moreover, the average crack length and width witness reductions of 40.24% and 35.43%, respectively, thereby corroborating the efficacy of the optimization method. Furthermore, an assessment of stress concentration and deformation within the structure is conducted. Through the optimization process, the maximum stress concentration in the structure diminishes by 25.22%, while the maximum deformation is curtailed by 30.32%. These results signify a substantial enhancement in structural stability. It is evident that the optimization algorithm exhibits robustness and stability in the context of crack control, consistently delivering favorable outcomes across diverse parameter configurations.

Aberrant peribiliary gland niche exacerbates fibrosis in primary sclerosing cholangitis and a potential therapeutic strategy.

Primary sclerosing cholangitis (PSC) is a rare but progressive and fatal autoimmune disease without clear pathogenesis and effective therapies. Peribiliary macrophage recruitment and peribiliary gland (PBG) proliferation and expansion have been associated with various cholangiopathies. This study aimed to evaluate the involvement of the PBG niche and macrophages in PSC progression, potential treatment strategies, and the underlying mechanism in acute and chronic experimental PSC. First, the upregulation of chemokines and fibrosis in PSC patients was confirmed via RNA-seq analysis. In vivo data illustrated that inflammation and fibrosis are the main characteristics, and recession of these can effectively interfere with PSC. Histopathological staining and RT-PCR revealed that more significant ductular reaction (DR) and PBG proliferation in the chronic PSC model, in which fibrosis mainly accumulated in the peribiliary area. In vitro, a transwell migration experiment showed that MCP-1 secreted by cholangiocytes in PBG niche, which recruited monocyte-derived macrophages (MoMFs) to the peribiliary area and promoted inflammation and fibrosis. Then, the luciferase assay and EMSA showed that POU6F1 could activate MCP-1 transcription. Furthermore, 18ß-Glycyrrhetinic acid (GA) reduced macrophages and fibrosis accumulated in the peribiliary, space and reduced PBG proliferation to benefit acute and chronic PSC models. Collectively, our results indicated that POU6F1 transcriptionally activates MCP-1, promoting the recruitment and infiltration of MoMFs and fibrosis into the PBG niche in PSC mouse models, and GA effectively suppressed the above phenotypes. These findings provide potential targets and a theoretical basis for the clinical treatment of PSC.

Challenges of fluoride pollution in environment: Mechanisms and pathological significance of toxicity - A review.

Fluoride is an important trace element in the living body. A suitable amount of fluoride has a beneficial effect on the body, but disproportionate fluoride entering the body will affect various organs and systems, especially the liver, kidneys, nervous system, endocrine system, reproductive system, bone, and intestinal system. In recent years, with the rapid development of agriculture and industry, fluoride pollution has become one of the important factors of environmental pollution, and fluoride pollution in any form is becoming a serious problem. Although countries around the world have made great breakthroughs in controlling fluoride pollution, however fluorosis still exists. A large amount of fluoride accumulated in animals will not only produce the toxic effects, but it also causes cell damage and affect the normal physiological activities of the body. There is no systematic description of the damage mechanism of fluoride. Therefore, the study on the toxicity mechanism of fluoride is still in progress. This review summarizes the existing information of several molecular mechanisms of the fluoride toxicity comprehensively, aiming to clarify the toxic mechanism of fluoride on various body systems. We have also summerized the pathological changes of those organ systems after fluoride poisoning in order to provide some ideas and solutions to the reader for the prevention and control of modern fluoride pollution.

Kupffer cells play a crucial role in monocrotaline-induced liver injury by producing TNF-α.

Monocrotaline (MCT), an unsaturated pyrrolizidine alkaloid (PA) in plants, is mainly toxic to the lung and liver of mammals. As a commonly used tool for liver injury model, the mechanism of MCT hepatoxicity has still not been fully clarified. Kupffer cells (KCs) are the liver-resident macrophages and have various responses to different toxicants and liver damage. However, the role of KCs in MCT-induced liver injury remains controversial. In current work, we investigated the effects of KCs on MCT-induced liver injury, especially on MCT-induced hepatocyte death. KCs were depleted in Balb/c mice by liposome-entrapped clodronate (Lip/Clo) (0.2 mL/mouse, i.p.) or GdCl3 (0.7 mg/kg, i.p.) before MCT administration (300 mg/kg, i.p.), we found that the Lip/Clo group showed higher efficiency in KCs depletion and stronger hepatoprotective effects against MCT. We also found TNF-α was remarkably decreased after KCs depletion, the experiment of administering anti-TNF-α antibody (20 µg/mouse, i.p.) to MCT-treated animals generated the similar results. To further elaborate the function of KCs, we compared the ALT levels released from co-culturing murine hepatic parenchymal cells (HPCs) and RAW264.7 cells with that from HPCs alone. After the treatment of MCT, the released ALT levels in co-culture system were shown to be dependent on the number of RAW264.7 cells, while the anti-TNF-α antibody could suppress it. Finally, we discovered RIPK3/MLKL pathway might be activated by TNF-α released from KCs, and subsequently induced hepatocyte necrosis. Noteworthy, the known mechanisms including ER stress and NF-κB pathways were also found to be involved in the activation of KCs. In conclusion, our study reveals a further mechanism to MCT-induced hepatoxicity mediated directly by KCs via producing TNF-α.

Prevention of D-GalN/LPS-induced ALI by 18ß-glycyrrhetinic acid through PXR-mediated inhibition of autophagy degradation.

Acute liver injury (ALI) has multiple causes and results in liver dysfunction. Severe or persistent liver injury eventually leads to liver failure and even death. Pregnane X receptor (PXR)-null mice present more severe liver damage and lower rates of autophagy. 18ß-glycyrrhetinic acid (GA) has been proposed as a promising hepatoprotective agent. We hypothesized that GA significantly alleivates D-GalN/LPS-induced ALI, which involved in PXR-mediated autophagy and lysosome biogenesis. We found that GA can significantly decrease hepatocyte apoptosis and increase the hepatic autophagy marker LC3-B. Ad-mCherry-GFP-LC3 tandem fluorescence, RNA-seq and real-time PCR indicated that GA may stabilize autophagosomes and lysosomes and inhibit autophagosome-lysosome fusion. Simultaneously, GA markedly activates PXR, even reversing the D-GalN/LPS-induced reduction of PXR and its downstream genes. In contrast, GA has a weak protective effect in pharmacological inhibition of PXR and PXR-null mice, which significantly affected apoptosis- and autophagy-related genes. PXR knockout interferes with the stability of autophagosomes and lysosomes, preventing GA reducing the expression of lysosomal genes such as Cst B and TPP1, and suppressing autophagy flow. Therefore, we believe that GA increases autophagy by inhibiting autophagosome-lysosome fusion and blocked autophagy flux via activation of PXR. In conclusion, our results show that GA activates PXR to regulate autophagy and lysosome biogenesis, represented by inhibiting autophagosome-lysosome fusion and stabilization of lysosome. These results identify a new mechanism by which GA-dependent PXR activation reduces D-GalN/LPS-induced acute liver injury.

Effects of fluoride and aluminum on expressions of StAR and P450scc of related steroidogenesis in guinea pigs' testis.

A lot of studies have shown that fluoride and aluminum have toxic effect on male reproductive system, but the mechanism of which and the interaction between fluoride and aluminum is still unknown. This study investigated the effects of fluoride (NaF) or/and aluminum (AlCl3) on serum testosterone level, gene and protein expression levels of Steroidogenic Acute Regulatory Protein (StAR) and Cytochrome P450 cholesterol side chain cleavage enzyme (P450scc) in the testes of guinea pigs. Fifty-two guinea pigs were divided randomly into four groups (Control, HiF, HiAl and HiF + HiAl). Fluoride (150 mg NaF/L) or/and aluminum (300 mg AlCl3/L) were orally administrated to male guinea pigs for 13 weeks. The results showed that F and Al reduced number and elevated abnormal ratio of sperm. Meanwhile, the concentrations of serum testosterone in all experimental groups were decreased. P450scc protein expression was significantly reduced in all treatment groups, and StAR expression was decreased remarkably in HiF group and HiF + HiAl group. The levels of StAR mRNA in three groups were reduced by 53.9%, 21.4% and 33.4%, respectively, while the expressions of P450scc mRNA were reduced by 67.8%, 17.0% and 47.8%. Therefore, we concluded that F induced the reduction in testosterone and sperm amount, and thus in lower fertility, which might occur as a consequence of depressed StAR and P450scc mRNA expression. There were no synergistic effects between F and Al, instead, Al weakened the toxicity of F to some extents. The results indicated that Al had antagonism effects on F.