Radiomics-based distinction of small (≤2 cm) hepatocellular carcinoma and precancerous lesions based on unenhanced MRI

AIM

To assess the feasibility of a radiomics model based on unenhanced magnetic resonance imaging (MRI) to differentiate small hepatocellular carcinoma (S-HCC) (≤2 cm) and pre-hepatocellular carcinoma (Pre-HCC).

MATERIALS AND METHODS

One hundred and fourteen histopathologically confirmed 114 hepatic nodules were analysed retrospectively. All patients had undergone MRI before surgery using a 3 T MRI system. Each nodule was segmented on unenhanced MRI sequences (T1-weighted imaging [T1] and T2WI with fat-suppression [FS-T2]). Radiomics features were extracted and the optimal features were selected using the least absolute shrinkage and selection operator (LASSO). The support vector machine (SVM) was used to establish the radiomics model. One abdominal radiologist performed the conventional qualitative analysis for classification of S-HCC and Pre-HCC. The diagnostic performances of the radiomics and radiologist models were evaluated using receiver operating characteristic (ROC) analysis.

RESULT

Radiomics features (n=1,223) were extracted from each sequence and the optimal features were selected from T1, FS-T2, and T1+FS-T2 to construct the radiomics models. The radiomics model based on T1+FS-T2 showed the best performance among the three models, with areas under the ROC curves (AUCs) of 0.95 (95 % confidence interval [CI], 0.875-0.986) and 0.942 (95 % CI, 0.775-0.985), accuracies of 86 % and 88.5 %, sensitivities of 94.12 % and 100 %, and specificities of 85.48 % and 85.19 %, respectively. The radiomics model on FS-T2 showed better performance on a single sequence than that of the T1-based model. The diagnostic performance for the radiomic model was significantly higher than that for the radiologist (AUC = 0.518, p<0.05).

CONCLUSION

This study suggested that a radiomics model based on unenhanced MRI may serve as a feasible and non-invasive tool to classify S-HCC and Pre-HCC.

Resveratrol Alleviates Zearalenone-Induced Intestinal Dysfunction in Mice through the NF-κB/Nrf2/HO-1 Signalling Pathway

Zearalenone (ZEA), a mycotoxin widely present in crops and food, poses a major threat to animal and human health. The consumption of ZEA-contaminated food or feed causes intestinal damage. Therefore, exploring how to mitigate the intestinal damage caused by its ZEA is becoming increasingly important. Resveratrol (RSV), a polyphenol compound, mainly exists in Vitis vinifera, Polygonum cuspidatum, Arachis hypogaea, and other plants. It has potent anti-inflammatory and antioxidant activity. The primary objective of this study was to assess the defensive effects of RSV and its molecular mechanism on the intestinal mucosal injury induced by ZEA exposure in mice. The results showed that RSV pretreatment significantly reduced serum DAO and that D-lactate levels altered intestinal morphology and markedly restored TJ protein levels, intestinal goblet cell number, and MUC-2 gene expression after ZEA challenge. In addition, RSV significantly reversed serum pro-inflammatory factor levels and abnormal changes in intestinal MDA, CAT, and T-SOD. Additional research demonstrated that RSV decreased inflammation by blocking the translocation of nuclear factor-kappaB (NF-κB) p65 and decreased oxidative stress by activating the nuclear factor E2-related factor 2 (Nrf2) pathway and its associated antioxidant genes, including NQO1, γ-GCS, and GSH-PX. In summary, RSV supplementation attenuates intestinal oxidative stress, inflammation, and intestinal barrier dysfunction induced by ZEA exposure by mediating the NF-κB and Nrf2/HO-1 pathways.

Oligomeric proanthocyanidins ameliorates osteoclastogenesis through reducing OPG/RANKL ratio in chicken's embryos

Skeletal disorders can seriously threaten the health and the performance of poultry, such as tibial dyschondroplasia (TD) and osteoporosis (OP). Oligomeric proanthocyanidins (OPC) are naturally occurring polyphenolic flavonoid compounds that can be used as potential substances to improve the bone health and the growth performance of poultry. Eighty 7-day-old green-eggshell yellow feather layer chickens were randomly divided into 4 groups: basal diet and basal diet supplementation with 25, 50, and 100 mg/kg OPC. The results have indicated that the growth performance and bone parameters of chickens were significantly improved supplementation with OPC in vivo, including the bone volume (BV), the bone mineral density (BMD) and the activities of antioxidative enzymes, but ratio of osteoprotegerin (OPG)/receptor activator of NF-κB (RANK) ligand (RANKL) was decreased. Furthermore, primary bone marrow mesenchymal stem cells (BMSCs) and bone marrow monocytes/macrophages (BMMs) were successfully isolated from femur and tibia of chickens, and co-cultured to differentiate into osteoclasts in vitro. The osteogenic differentiation derived from BMSCs was promoted treatment with high concentrations of OPC (10, 20, and 40 µmol/L) groups in vitro, but emerging the inhibition of osteoclastogenesis by increasing the ratio of OPG/RANKL. In contrary, the osteogenic differentiation was also promoted treatment with low concentrations of OPC (2.5, 5, and 10 µmol/L) groups, but osteoclastogenesis was enhanced by decreasing the ratio of OPG/RANKL in vitro. In addition, OPG inhibits the differentiation and activity of osteoclasts by increasing the autophagy in vitro. Dietary supplementation of OPC can improve the growth performance of bone and alter the balance of osteoblasts and osteoclasts, thereby improving the bone health of chickens.

TFAM-mediated intercellular lipid droplet transfer promotes cadmium-induced mice nonalcoholic fatty liver disease

Cadmium (Cd) is an important environmental pollutant. Herein, we discovered a new way of lipid accumulation, where lipid droplets can be transferred across cells. In this study, mice and AML12 cells were used to establish models of Cd poisoning. After Cd treatment, the level of TFAM was reduced, thereby regulating the reconstitution of the cytosolic actin filament network. MYH9 is a myosin involved in cell polarization, migration, and movement of helper organelles. Rab18 is a member of the Rab GTPase family, which localizes to lipid droplets and regulates lipid drop dynamics. In this study, we found that Cd increases the interaction between MYH9 and Rab18. However, TFAM overexpression alleviated the increase in Cd-induced interaction between MYH9 and Rab18, thereby reducing the transfer of intercellular lipid droplets and the accumulation of intracellular lipids. Through a co-culture system, we found that the transferred lipid droplets can act as a signal to form an inflammatory storm-like effect, and ACSL4 can act as an effector to transfer lipid droplets and promote lipid accumulation in surrounding cells. These results suggest that TFAM can be used as a new therapeutic target for Cd-induced lipid accumulation in the liver.

Baicalin and N-acetylcysteine regulate choline metabolism via TFAM to attenuate cadmium-induced liver fibrosis

(Background): Cadmium is an environmental pollutant associated with several liver diseases. Baicalin and N-Acetylcysteine have antioxidant and hepatoprotective effects. (Purpose): However, it is unclear whether baicalin and N-Acetylcysteine can alleviate Cadmium -induced liver fibrosis by regulating metabolism, or whether they exert a synergistic effect. (Study design): We treated Cadmium-poisoned mice with baicalin, N-Acetylcysteine, or baicalin+ N-Acetylcysteine. We studied the effects of baicalin and N-Acetylcysteine on Cadmium-induced liver fibers and their specific mechanisms. (Methods): We used C57BL/6 J mice, and AML12, and HSC-6T cells to establish in vitro assays and in vivo models. (Results): Metabolomics was used to detect the effect of baicalin and N-Acetylcysteine on liver metabolism, which showed that compared with the control group, the Cadmium group had increased fatty acid and amino acid levels, with significantly reduced choline and acetylcholine contents. Baicalin and N-Acetylcysteine alleviated these Cadmium-induced metabolic changes. We further showed that choline alleviated Cadmium -induced liver inflammation and fibrosis. In addition, cadmium significantly promoted extracellular leakage of lactic acid, while choline alleviated the cadmium -induced destruction of the cell membrane structure and lactic acid leakage. Western blotting showed that cadmium significantly reduced mitochondrial transcription factor A (TFAM) and Choline Kinase α(CHKα2) levels, and baicalin and N-Acetylcysteine reversed this effect. Overexpression of Tfam in mouse liver and AML12 cells increased the expression of CHKα2 and the choline content, alleviating and cadmium-induced lactic acid leakage, liver inflammation, and fibrosis. (Conclusion): Overall, baicalin and N-Acetylcysteine alleviated cadmium-induced liver damage, inflammation, and fibrosis to a greater extent than either drug alone. TFAM represents a target for baicalin and N-Acetylcysteine, and alleviated cadmium-induced liver inflammation and fibrosis by regulating hepatic choline metabolism.

Vertical distribution of VOCs in the boundary layer of the Lhasa valley and its impact on ozone pollution

To investigate the vertical distribution of volatile organic compounds (VOCs) concentrations in the Lhasa valley region, an intensive measurement campaign was first conducted in summer using a tethered balloon. The results showed that the average concentration of surface VOCs was 49.1 ± 30.1 ppbv, alkanes and aromatics were the main components. Notably, a very large discrepancy in VOCs was obtained between the wet (71.6 ± 25.9 ppbv) and dry (25.6 ± 8.0 ppbv) episodes, which was attributed to the atmospheric stability and diffusion capacity. Moreover, the total VOC (TVOCs) concentration declined under fluctuations, but it rapidly increased with height in the afternoon during the wet episode (2.50 ppbv/100 m, R2 = 0.47). According to the PMF results, combustion was the dominant emission source, additionally, the contribution of solvent coating in the wet episode and the background in the dry episode increased with height. Moreover, the O3 concentration increased with height, and the decrease in LNOx-OH could effectively prevent the occurrence of high O3 values. This study indicated that low wind speeds and high humidity levels highly likely cause the accumulation of atmospheric VOCs under static and stable conditions, while the control of high O3 concentrations must still greatly consider summertime NOx emissions in Lhasa.

Polystyrene nanoplastics aggravate reproductive system damage in obese male mice by perturbation of the testis redox homeostasis

The potential impact of the combination of a high-fat diet (HFD) and polystyrene nanoplastics (PS-NPs) on fertility cannot be ignored, especially when the fertility rate is declining. However, it has not attracted considerable attention. In this study, an obese mouse model was established using an HFD, and the reproductive function of male mice was evaluated after intragastric administration of 100 μL of a 10 mg/mL PS-NP suspension for 4 weeks. By determining the morphology and vitality of sperm and related indicators of testosterone production, it was found that PS-NPs aggravated the destruction of sperm mitochondrial structure, decrease sperm activity, and testosterone production in HFD-fed mice. To comprehensively analyze the injury mechanism, the integrity of the blood testicular barrier (BTB) and the function of Leydig and Sertoli cells were further analyzed. It was found that PS-NPs could destroy BTB, promote the degeneration of Leydig cells, reduce the number of Sertoli cells, and decrease lactate secretion in HFD-fed mice. PS-NPs further interfered with redox homeostasis in the testicular tissues of HFD-fed mice. This study found that PS-NPs could aggravate the damage to the reproductive system of obese male mice by further perturbing its redox homeostasis and revealed the potential health risk of PS-NPs exposure under an HFD.

Co-exposure to cadmium and microplastics promotes liver fibrosis through the hemichannels -ATP-P2X7 pathway

Microplastics (MPs) and cadmium (Cd) are important environmental pollutants, that damage the liver. However, the effect and mechanism of combined Cd and MPs exposure on liver fibrosis are still largely unknown. In this study investigated, Cd + MPs exposure increased superoxide anion production and promoted extracellular ATP release compared with exposure to Cd or MPs individually. Cd + MPs increased inflammatory cell infiltration, activated the P2X7-NLRP3 signaling pathway, and promoted inflammatory factor release. Cd + MPs aggravated Cd- or MPs-induced liver fibrosis and induced liver inflammation. In AML12/HSC-T6 cell in vitro poisoning model, exposure of AML12 cells to Cd + MPs increased the opening of connexin hemichannels and promoted extracellular ATP release. Treatment of HSC-T6 cells with the supernatant of AML12 cells exposed to Cd + MPs significantly promoted HSC-T6 cell activation. Treatment of HSC-T6 cells with different concentrations of ATP produced similar results. TAT-Gap19TFA, an inhibitor of connexin hemichannels, significantly inhibited the ATP release and activation of Cd + MPs-treated HSC-T6 cells. Finally, the expression of the ATP receptor P2X7 was silenced in HSC-T6 cells, which significantly inhibited their activation. In conclusion, exposure to Cd + MPs promoted liver fibrosis through the ATP-P2X7 pathway and synergistically affected liver inflammation and fibrosis.

Real-life exposure to Fusarium toxins deoxynivalenol and zearalenone triggers apoptosis and activates NLRP3 inflammasome in bovine primary theca cells

Cattle are deemed less susceptible to mycotoxins due to the limited internal exposure resulting from rumen microbiota activity. However, the significant amounts of Fusarium mycotoxins deoxynivalenol (DON) and zearalenone (ZEN) frequently detected in bovine follicular fluid samples suggest that they could affect ovarian function. Both mycotoxins trigger several patterns of cell death and activate the NLRP3 inflammasome in the intestine. In vitro studies have reported a number of adverse effects on bovine oocytes. However, the biological relevance of such findings with regard to realistic concentrations of DON and ZEN in bovine follicular fluid is still not clear. Hence, it is important to better characterize the effects of dietary exposure to DON and ZEN on the bovine ovary. Using bovine primary theca cells, this study investigated the effects of real-life patterns for bovine ovary exposure to DON and ZEN, but also DON metabolite DOM-1, on cell death and NLRP3 inflammasome activation. Exposure to DON starting from 0.1 μM significantly decreased theca cell viability. The kinetics of phosphatidylserine translocation and loss of membrane integrity showed that ZEN and DON, but not DOM-1, induce an apoptotic phenotype. qPCR analysis of the expression of NLRP3, PYCARD, IL-1β, IL-18, and GSDMD in primary theca cells at concentrations of mycotoxin previously reported in cow follicular fluid clearly indicated that DON and DOM-1 individually and in mixture, but not ZEN, activate NLRP3 inflammasome. Altogether, these results suggest that real-life dietary exposure of cattle to DON may induce inflammatory disorders in the ovary.

Cadmium promotes nonalcoholic fatty liver disease by inhibiting intercellular mitochondrial transfer

Mitochondrial transfer regulates intercellular communication, and mitochondria regulate cell metabolism and cell survival. However, the role and mechanism of mitochondrial transfer in Cd-induced nonalcoholic fatty liver disease (NAFLD) are unclear. The present study shows that mitochondria can be transferred between hepatocytes via microtubule-dependent tunneling nanotubes. After Cd treatment, mitochondria exhibit perinuclear aggregation in hepatocytes and blocked intercellular mitochondrial transfer. The different movement directions of mitochondria depend on their interaction with different motor proteins. The results show that Cd destroys the mitochondria-kinesin interaction, thus inhibiting mitochondrial transfer. Moreover, Cd increases the interaction of P62 with Dynactin1, promotes negative mitochondrial transport, and increases intracellular lipid accumulation. Mitochondria and hepatocyte co-culture significantly reduced Cd damage to hepatocytes and lipid accumulation. Thus, Cd blocks intercellular mitochondrial transfer by disrupting the microtubule system, inhibiting mitochondrial positive transport, and promoting their negative transport, thereby promoting the development of NAFLD.

Erratum: Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande [Phys. Rev. Lett. 130, 031802 (2023)]

This corrects the article DOI: 10.1103/PhysRevLett.130.031802.

VPS41-mediated incomplete autophagy aggravates cadmium-induced apoptosis in mouse hepatocytes

Exposure to cadmium (Cd), an environmental heavy metal contaminant, is a serious threat to global health that increases the burden of liver diseases. Autophagy and apoptosis are important in Cd-induced liver injury. However, the regulatory mechanisms involved in the progression of Cd-induced liver damage are poorly understood. Herein, we investigated the role of vacuolar protein sorting 41 (VPS41) in Cd-induced autophagy and apoptosis in hepatocytes. We used targeted VPS41 regulation to elucidate the mechanism of Cd-induced hepatotoxicity. Our data showed that Cd triggered incomplete autophagy by downregulating VPS41, aggravating Cd-induced hepatocyte apoptosis. Mechanistically, Cd-induced VPS41 downregulation interfered with the mTORC1-TFEB/TFE3 axis, leading to an imbalance in autophagy initiation and termination and abnormal activation of autophagy. Moreover, Cd-induced downregulation of VPS41 inhibited autophagosome-lysosome fusion, leading to blocked autophagic flux. This triggers incomplete autophagy, which causes excessive P62 accumulation, accelerating Caspase-9 (CASP9) cleavage. Incomplete autophagy blocks clearance of cleaved CASP9 (CL-CASP9) via the autophagic pathway, promoting apoptosis. Notably, VPS41 overexpression alleviated Cd-induced incomplete autophagy and apoptosis, independent of the homotypic fusion and protein sorting complex. This study provides a new mechanistic understanding of the relationship between autophagy and apoptosis, suggesting that VPS41 is a new therapeutic target for Cd-induced liver damage.

Interactive mechanism between connexin43 and Cd-induced autophagic flux blockage and gap junctional intercellular communication dysfunction in rat hepatocytes

Cadmium (Cd) is a significant environmental contaminant known for its potential hepatotoxic effects. However, the precise mechanisms underlying Cd-induced hepatotoxicity have yet to be fully understood. Therefore, the purpose of this study was to investigate the dynamic role of connexin 43 (Cx43) in response to Cd exposure, particularly its impact on gap junctional intercellular communication (GJIC) and autophagy in hepatocytes. To establish an in vitro model of Cd-induced hepatocyte injury, the Buffalo rat liver 3A cell line (BRL3A) was utilized.In order to elucidate the mechanism by which Cx43 influences Cd-induced hepatocyte toxic injury, inhibitors of Cx43 (Dynasore) and P-Cx43 (Ro318220) were employed in the model. The findings revealed that inhibiting Cx43 and its phosphorylation further compromised GJIC function, exacerbating the impairment, while also intensifying the blockage of autophagic flux. To gain further insight into the role of Cx43, siRNA was utilized to knock down Cx43 expression, yielding similar results. The down-regulation of Cx43 expression was found to worsen the morphological damage induced by cadmium exposure, diminish the cell proliferation capacity of BRL3A cells, and exacerbate the disruption of GJIC and autophagic flow caused by Cd.These findings suggest that Cx43 may serve as a potential therapeutic target for the treatment of liver damage resulting from Cd exposure. By targeting Cx43, it may be possible to mitigate the adverse effects of Cd on hepatocytes.

Vitamin D Alleviates Cadmium-Induced Inhibition of Chicken Bone Marrow Stromal Cells' Osteogenic Differentiation In Vitro

Vitamin D is a lipid soluble vitamin that is mostly used to treat bone metabolism-related diseases. In this study, the effect of Cd toxicity in vitro on osteogenic differentiation derived from BMSCs and the alleviating effect of lα, 25-(OH)2D3 were investigated. Cell index in real time was monitored using a Real-time cell analyzer (RTCA) system. The activity of alkaline phosphatase (ALP), and the calcified nodules and the distribution of Runx2 protein were detected using ALP staining, alizarin red staining, and immunofluorescence, respectively. Furthermore, the mitochondrial membrane potential and the apoptotic rate of BMSCs, the mRNA levels of RUNX2 and type Ⅰ collagen alpha2 (COL1A2) genes, and the protein expression of Col1 and Runx2 were detected using flow cytometry, qRT-PCR and western blot, respectively. The proliferation of BMSCs and osteogenic differentiation were enhanced after treatment with different concentrations of lα, 25-(OH)2D3 compared with the control group. However, 5 μmol/L Cd inhibited the proliferation of BMSCs. In addition, 10 nmol/L lα,25-(OH)2D3 attenuated the toxicity and the apoptosis of BMSCs treated by Cd, and also promoted the osteogenic differentiation including the activity of ALP, and the protein expression of Col1 and Runx2. lα, 25-(OH)2D3 can alleviate cadmium-induced osteogenic toxicity in White Leghorn chickens in vitro.

Melatonin alleviates cadmium-induced nonalcoholic fatty liver disease in ducks by alleviating autophagic flow arrest via PPAR-α and reducing oxidative stress

Cadmium (Cd) is an important environmental pollutant that causes liver damage and induces nonalcoholic fatty liver disease (NAFLD). NAFLD is a fat accumulation disease and has significant effects on the body. Melatonin (Mel) is an endogenous protective molecule with antioxidant, anti-inflammatory, antiobesity, and antiaging effects. However, whether Mel can alleviate Cd-induced NAFLD and its mechanism remains unclear. First, in vivo, we found that Mel maintained mitochondrial structure and function, inhibited oxidative stress, and reduced Cd-induced liver injury. In addition, Mel alleviated lipid accumulation in the liver induced by Cd. In this process, Mel inhibits fatty acid production and promotes fatty acid oxidation. Interestingly, Mel regulated PPAR-α expression and alleviated Cd-induced autophagy blockade. In vitro model, the oil Red O staining, and WB results showed that Mel alleviated Cd-induced lipid accumulation. In addition, RAPA was used to activate autophagy to alleviate Cd-induced lipid accumulation, and TG was used to block autophagy flux to aggravate Cd-induced autophagy accumulation. After knocking down PPAR-α, the autophagosome fusion with lysosomes, and autophagic flux was inhibited and increased Cd-induced lipid accumulation. Mel alleviates mitochondrial damage and oxidative stress, and attenuates Cd-induced NAFLD by restoring the expression of PPAR-α and restoring autophagy flux.

Fusarium Mycotoxins Zearalenone and Deoxynivalenol Reduce Hepatocyte Innate Immune Response after the Listeria monocytogenes Infection by Inhibiting the TLR2/NFκB Signaling Pathway

Zearalenone (ZEA) and deoxynivalenol (DON) are two common mycotoxins produced by the genus Fusarium and have potential immunotoxic effects that may lead to a weak immune response against bacterial infections. Listeria monocytogenes (L. monocytogenes), a food-borne pathogenic microorganism ubiquitous in the environment, actively multiplies in the liver, where hepatocytes are capable of resistance through mediated innate immune responses. At present, it is not clear if ZEA and DON affect hepatocyte immune responses to L. monocytogenes infection or the mechanisms involved. Therefore, in this study, in vivo and in vitro models were used to investigate the effects of ZEA and DON on the innate immune responses of hepatocytes and related molecules after L. monocytogenes infection. In vivo studies revealed that ZEA and DON inhibited the toll-like receptors 2 (TLR2)/nuclear factor kappa-B (NFκB) pathway in the liver tissue of L. monocytogenes-infected mice, downregulating the expression levels of Nitric oxide (NO), in the liver and repressing the immune response. In addition, ZEA and DON inhibited Lipoteichoic acid (LTA)-induced expression of TLR2 and myeloid differentiation factor 88 (MyD88) in Buffalo Rat Liver (BRL 3A) cells in vitro, downregulating the TLR2/NFκB signaling pathway and resulting in the decreased expression levels of NO, causing immunosuppressive effects. In summary, ZEA and DON can negatively regulate NO levels through TLR2/NFκB, inhibiting the innate immune responses of the liver, and aggravate L. monocytogenes infections in mouse livers.

Puerarin Prevents Cadmium-Induced Neuronal Injury by Alleviating Autophagic Dysfunction in Rat Cerebral Cortical Neurons

Autophagic dysfunction is one of the main mechanisms of cadmium (Cd)-induced neurotoxicity. Puerarin (Pue) is a natural antioxidant extracted from the medicinal and edible homologous plant Pueraria lobata. Studies have shown that Pue has neuroprotective effects in a variety of brain injuries, including Cd-induced neuronal injury. However, the role of Pue in the regulation of autophagy to alleviate Cd-induced injury in rat cerebral cortical neurons remains unclear. This study aimed to elucidate the protective mechanism of Pue in alleviating Cd-induced injury in rat cerebral cortical neurons by targeting autophagy. Our results showed that Pue alleviated Cd-induced injury in rat cerebral cortical neurons in vitro and in vivo. Pue activates autophagy and alleviates Cd-induced autophagic blockade in rat cerebral cortical neurons. Further studies have shown that Pue alleviates the Cd-induced inhibition of autophagosome-lysosome fusion, as well as the inhibition of lysosomal degradation. The specific mechanism is related to Pue alleviating the inhibition of Cd on the expression levels of the key proteins Rab7, VPS41, and SNAP29, which regulate autophagosome-lysosome fusion, as well as the lysosome-related proteins LAMP2, CTSB, and CTSD. In summary, these results indicate that Pue alleviates Cd-induced autophagic dysfunction in rat cerebral cortical neurons by alleviating autophagosome-lysosome fusion dysfunction and lysosomal degradation dysfunction, thereby alleviating Cd-induced neuronal injury.

Polystyrene Microplastics Induce Oxidative Stress in Mouse Hepatocytes in Relation to Their Size

Microplastics have become a new type of environmental pollutant that can accumulate in various tissues and organs of the body and cause chronic damage. In this study, two different size polystyrene microplastics (PS-MPs, 5 μm and 0.5 μm) exposure models were established in mice to investigate the effects of PS-MPs with different particle sizes on oxidative stress in the liver. The results showed that PS-MPs exposure caused a decrease in body weight and liver-to-body weight. The hematoxylin and eosin staining and transmission electron microscopy results showed that exposure to PS-MPs led to the disorganized cellular structure of liver tissue, nuclear crinkling, and mitochondrial vacuolation. The extent of damage in the 5 μm PS-MP exposure group was more extensive when compared with the other group. The evaluation of oxidative-stress-related indicators showed that PS-MPs exposure exacerbated oxidative stress in hepatocytes, especially in the 5 μm PS-MPs group. The expression of oxidative-stress-related proteins sirtuin 3(SIRT3) and superoxide dismutase (SOD2) was significantly reduced, and the reduction was more pronounced in the 5 μm PS-MPs group. In conclusion, PS-MPs exposure led to oxidative stress in mouse hepatocytes and caused more severe damage in the 5 μm PS-MPs group when compared with the 0.5 μm PS-MPs group.

Polystyrene exacerbates cadmium-induced mitochondrial damage to lung by blocking autophagy in mice

Cadmium (Cd) is an environmental heavy metal, and its accumulation is harmful to animal and human health. The cytotoxicity of Cd includes oxidative stress, apoptosis, and mitochondrial histopathological changes. Furthermore, polystyrene (PS) is a kind of microplastic piece derived from biotic and abiotic weathering courses, and has toxicity in various aspects. However, the potential mechanism of action of Cd co-treated with PS is still poorly unclear. The objective of this study was to investigate the effects of PS on Cd-induced histopathological injury of mitochondria in the lung of mice. In this study, the results have showed that Cd could induce the activity of oxidative enzymes of the lung cells in mice, increasing the content of partial microelement and the phosphorylation of inflammatory factor NF-κB p65. Cd further destroys the integrity of mitochondria by increasing the expression of apoptotic protein and blocking the autophagy. In addition, PS solely group aggravated the lung damage in mice, especially mitochondrial toxicity, and played a synergistic effect with Cd in lung injury. However, how PS can augment mitochondrial damage and synergism with Cd in lung of mice requiring further exploration. Therefore, PS was able to exacerbate Cd-induced mitochondrial damage to the lung in mice by blocking autophagy, and was associated with the apoptosis.

Cadmium induces mitochondrial dysfunction via SIRT1 suppression-mediated oxidative stress in neuronal cells

Cadmium is a widespread environmental contaminant and its neurotoxicity has raised serious concerns. Mitochondrial dysfunction is a key event in Cd-induced nervous system disease; however, the exact molecular mechanism involved has not been fully elucidated. Increasing evidences have shown that Sirtuin 1 (SIRT1) is the key target protein impaired in Cd-induced mitochondrial dysfunction. In this study, the role of SIRT1 in Cd-induced mitochondrial dysfunction and cell death and the underlying mechanisms were evaluated in vitro using PC12 cells and primary rat cerebral cortical neurons. The results showed that Cd exposure caused cell death by inhibiting SIRT1 expression, thus inducing oxidative stress and mitochondrial dysfunction in vitro. However, inhibition of oxidative stress by the antioxidant puerarin alleviated Cd-induced mitochondrial dysfunction. Furthermore, activation of SIRT1 using the agonist Srt1720 significantly abolished Cd-induced oxidative stress and mitochondrial dysfunction and ultimately alleviated Cd-induced neuronal cell death. Collectively, our data indicate that Cd induced mitochondrial dysfunction via SIRT1 suppression-mediated oxidative stress, leading to the death of PC12 cells and primary rat cerebral cortical neurons. These findings suggest a novel mechanism for Cd-induced neurotoxicity.

Measurement of the ν_{e}-Nucleus Charged-Current Double-Differential Cross Section at ⟨E_{ν}⟩=2.4 GeV Using NOvA

The inclusive electron neutrino charged-current cross section is measured in the NOvA near detector using 8.02×10^{20} protons-on-target in the NuMI beam. The sample of GeV electron neutrino interactions is the largest analyzed to date and is limited by ≃17% systematic rather than the ≃7.4% statistical uncertainties. The double-differential cross section in final-state electron energy and angle is presented for the first time, together with the single-differential dependence on Q^{2} (squared four-momentum transfer) and energy, in the range 1  GeV≤E_{ν}<6  GeV. Detailed comparisons are made to the predictions of the GENIE, GiBUU, NEUT, and NuWro neutrino event generators. The data do not strongly favor a model over the others consistently across all three cross sections measured, though some models have especially good or poor agreement in the single differential cross section vs Q^{2}.

Zearalenone damages the male reproductive system of rats by destroying testicular focal adhesion

Zearalenone (ZEA), a common mycotoxin in animal feed, is harmful to public health and causes huge economic losses. The potential target proteins of ZEA and its derivatives were screened using the PharmMapper database and the related genes (proteins) of the testis were obtained from Genecards. We obtained 144 potential targets of ZEA and its derivatives related to the testis using Venn diagrams. The PPI analysis showed that ZEA had the most targets in testis, followed by ZAN, α-ZAL, β-ZEL, α-ZEL, and β-ZAL. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses evaluated the metabolic and cancer pathways. We further screened four hub genes: RAC3, CCND1, EP300, and CTNNB1. Eight key biological processes were obtained by GO analysis, and four important pathways were identified by KEGG analysis. Animal and cell experimental results confirmed that ZEA could inhibit the expression of four key KEGG pathway protein components and four hub proteins that interfere with cell adhesion by inhibiting the focal adhesion structure of the testis, Leydig cells, and Sertoli cells. Collectively, our findings reveal that the destruction of the focal adhesion structure in the testis is the mechanism through which ZEA damages the male reproductive system.

Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande

We report a search for cosmic-ray boosted dark matter with protons using the 0.37  megaton×years data collected at Super-Kamiokande experiment during the 1996-2018 period (SKI-IV phase). We searched for an excess of proton recoils above the atmospheric neutrino background from the vicinity of the Galactic Center. No such excess is observed, and limits are calculated for two reference models of dark matter with either a constant interaction cross section or through a scalar mediator. This is the first experimental search for boosted dark matter with hadrons using directional information. The results present the most stringent limits on cosmic-ray boosted dark matter and exclude the dark matter-nucleon elastic scattering cross section between 10^{-33}cm^{2} and 10^{-27}cm^{2} for dark matter mass from 1  MeV/c^{2} to 300  MeV/c^{2}.

Honokiol reduces cadmium-induced oxidative injury and endosomal/lysosomal vacuolation via protecting mitochondrial function in quail (Coturnix japonica) liver tissues

Cadmium (Cd) pollution in environment is toxic to birds. This study aimed to assess antagonistic effect of honokiol (HNK) on Cd-induced quail (Coturnix japonica) liver tissue damage and Cd-induced vacuolation in hepatocytes. We found that HNK alleviated Cd-induced liver pathological damage marked by elevated serum liver biochemical indicators, disordered antioxidant levels and trace elements in quails. HNK reduced Cd-induced liver cell apoptosis as assessed by western blotting and TUNEL staining. The ultrastructure of hepatocytes under transmission electron microscope revealed that Cd induced mitochondrial damage in addition to abnormal enlargement and increased vacuolar structure of cells. Mitochondrial damage and vacuolization were reduced in the HNK + Cd group. Cd induced an increase in the levels of endosomal/lysosomal-related genes, while HNK treatment reversed this effect. Finally, we demonstrated that vacuolation in buffalo rat liver 3A (BRL 3A) cells occurred primarily due to Cd-induced oxidative stress damage that reduces mitochondrial ATP content and indirectly led to dysfunction of ATP-dependent lipid kinase PIKfyve complex. In summary, we are the first to report that Cd induces abnormal enlargement of endosome/lysosomes in quail liver cells and HNK alleviated this phenomenon by reducing mitochondrial damage and increasing intracellular ATP level. This study demonstrated the toxic effect of Cd pollution on birds and how HNK mitigated these effect at the cellular level. Overall, more research on Cd pollution and HNK use in animal husbandry is warranted.

Taurine Alleviates Cadmium-Induced Hepatotoxicity by Regulating Autophagy Flux

Our previous studies have confirmed that cadmium (Cd) exposure causes hepatotoxicity; it also induces autophagy and blocks the autophagy flux. Therefore, we hypothesized that Cd hepatotoxicity could be alleviated through nutritional intervention. Taurine (Tau) has various biological functions such as acting as an antioxidant, acting as an anti-inflammatory, and stabilizing cell membranes. In order to explore the protective effect and internal mechanism of Tau on Cd-induced hepatotoxicity, normal rat liver cell line BRL3A cells were treated with Cd alone or in combination with Tau to detect cell injury and autophagy-related indexes in this study. We found that Tau can alleviate Cd-induced cell-proliferation decline and morphological changes in the cell. In addition, Tau activates autophagy and alleviates the blockage of Cd-induced autophagy flux. In this process, lysosome acidification and degradation were enhanced, and autophagosomes were further fused with lysosomes. Then, we found that Tau alleviated autophagic flux block by promoting the transfer of membrane fusion proteins STX17 and SNAP29 to autophagosomes and the translocation of VAMP8 to lysosomes, which in turn attenuated the hepatocyte injury induced by Cd exposure. This will further reveal the hepatotoxicity mechanism of Cd and provide the theoretical basis for the prevention and treatment of Cd poisoning.

Rat Hepatocytes Mitigate Cadmium Toxicity by Forming Annular Gap Junctions and Degrading Them via Endosome-Lysosome Pathway

Gap junction protein connexin 43 (Cx43) plays a critical role in gap junction communication in rat hepatocytes. However, those located between hepatocytes are easily internalized following exposure to poisons. Herein, we investigated the potential of buffalo rat liver 3A (BRL 3A) cells to generate annular gap junctions (AGJs) proficient at alleviating cadmium (Cd) cytotoxic injury through degradation via an endosome-lysosome pathway. Our results showed that Cd-induced damage of liver microtubules promoted Cx43 internalization and increased Cx43 phosphorylation at Ser373 site. Furthermore, we established that Cd induced AGJs generation in BRL 3A cells, and AGJs were subsequently degraded through the endosome-lysosome pathway. Overall, our results suggested that Cx43 internalization and the generation of AGJs were cellular protective mechanisms to alleviate Cd toxicity in rat hepatocytes.

Puerarin alleviates cadmium-induced rat neurocyte injury by alleviating Nrf2-mediated oxidative stress and inhibiting mitochondrial unfolded protein response

Cadmium (Cd) is a highly neurotoxic environmental pollutant. Puerarin (Pur) is a natural antioxidant isolated from Kudzu root that exhibits a powerful neuroprotective effect. Herein, we illustrated the mechanism underlying the protective effect of Pur on Cd-induced rat neurocyte injury in an in vivo rat model as well as in vitro using PC12 cells and primary rat cerebral cortical neurons. First, the results showed that Pur alleviated Cd-induced cerebral cortical pathological damage and decreased the viability of neurocytes. Furthermore, Cd activated the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway, which plays a negative role in Cd-induced rat neurocyte injury. In addition, Pur alleviated Cd-induced oxidative stress by enhancing antioxidant defense, reducing reactive oxygen species (ROS) accumulation and lipid peroxidation, and inhibiting activation of the Nrf2 signaling pathway in rat neurocytes. Moreover, Pur inhibited the Cd-induced mitochondrial unfolded protein response (UPRmt) in rat neurocytes. Overall, Pur alleviated Cd-induced rat neurocyte injury by alleviating Nrf2-mediated oxidative stress and inhibiting UPRmt.

The urgent need to control volatile organic compound pollution over the Qinghai-Tibet Plateau

Owing to the impact of the western development of China, there have been signs of air pollution over the Qinghai-Tibet Plateau in recent years. However, monitoring data on atmospheric volatile organic compounds (VOCs) are lacking in plateau areas. Here, VOCs concentrations in urban and background areas in North China and the Qinghai-Tibet Plateau were observed from 2012 to 2014 and 2020 to 2022, respectively. Compared to 2012-2014, the concentration of VOCs increased to 2.5 times in urban areas on the Qinghai-Tibet Plateau, which was equivalent to that in North China. Oil, gas, and solvent evaporation caused by a low atmospheric pressure is the primary factor for the increase in VOCs in plateau areas, and weak VOCs degradation is the secondary factor. Hence, we put forward the VOCs control strategies in plateau areas and point out the defects in the current research.

Microplastics Exacerbate Cadmium-Induced Kidney Injury by Enhancing Oxidative Stress, Autophagy, Apoptosis, and Fibrosis

Cadmium (Cd) is a potential pathogenic factor in the urinary system that is associated with various kidney diseases. Microplastics (MPs), comprising of plastic particles less than 5 mm in diameter, are a major carrier of contaminants. We applied 10 mg/L particle 5 μm MPs and 50 mg/L CdCl2 in water for three months in vivo assay to assess the damaging effects of MPs and Cd exposure on the kidney. In vivo tests showed that MPs exacerbated Cd-induced kidney injury. In addition, the involvement of oxidative stress, autophagy, apoptosis, and fibrosis in the damaging effects of MPs and Cd on mouse kidneys were investigated. The results showed that MPs aggravated Cd-induced kidney injury by enhancing oxidative stress, autophagy, apoptosis, and fibrosis. These findings provide new insights into the toxic effects of MPs on the mouse kidney.

Gap junction intercellular communication mediates cadmium-induced apoptosis in hepatocytes via the Fas/FasL pathway

As a common environmental pollutant, cadmium (Cd) causes damage to many organs of the body. Gap junction intercellular communication (GJIC) represents one of the most important routes of rapid signaling between cells. However, the mechanisms underlying GJIC's role in hepatotoxicity induced by Cd remain unknown. We established a Cd poisoning model in vitro by co-culturing Cd-exposed and unexposed hepatocytes and found that 18β-glycyrrhetinic acid (GA), a GJIC inhibitor, can effectively reduce the apoptosis rate of healthy cells co-cultured with apoptotic cells treated with Cd. We also found that anti-FasL antibody had the same effect. However, in mono-cultured cells, GA treatment in combination with Cd was found to aggravate the damage induced by Cd exposure, increase the level of oxidative stress and protein expression of HO-1, decrease the mitochondrial membrane potential, incur more serious morphological damage to mitochondria than Cd treatment alone. Moreover, compared with Cd-only exposure, GA and Cd co-treatment further increased the expression levels of the apoptosis-related proteins Fas, FasL, FADD and the ratio of Bax/Bcl-2, inhibited the protein expression of ASK1 and Daxx. We also found that the protein expression of Daxx in siFADD + Cd hepatocytes was significantly higher than in Cd-treated cells. Thus, our study suggests that gap junction inhibition may play a dual role in Cd-induced cell damage by inhibiting the transmission of death signals from damaged cells to healthy cells but also aggravating the transmission of death signals between damaged cells, and that the Fas/FasL-mediated death receptor pathway may play an important role in this process.

PINK1/Parkin-mediated mitophagy modulates cadmium-induced apoptosis in rat cerebral cortical neurons

Cadmium is a persistent environmental pollutant whose neurotoxicity is of serious concern. Mitochondrial dysfunction and its mediated mitophagy and apoptosis are considered key events in Cd-induced neurological pathologies, but the exact molecular mechanism has not been fully elucidated. The aim of this study was to investigate the relationship between Cd-induced mitophagy and apoptosis and their role in Cd-induced neuronal death. Using the mitophagy inhibitor cyclosporine A (CsA), we found that the extent of mitophagy mediated by the PTEN-induced putative kinase protein 1 (PINK1)/E3 ubiquitin ligase (Parkin) pathway decreased, whereas the level of apoptosis and cell death increased in rat cerebral cortical neurons in vitro. Consistent with this, the knockdown of PINK1 also exacerbated Cd-induced apoptosis and neuronal death. Furthermore, the results of the in vivo experiments showed that Cd simultaneously activated both mitophagy and apoptosis and that the suppression of mitophagy by CsA aggravated Cd-induced apoptosis. In summary, our results indicate that PINK1/Parkin-mediated mitophagy exerts an important neuroprotective effect by inhibiting Cd-mediated apoptosis in rat cerebral cortical neurons both in vitro and in vivo. This work may allow the development of new therapeutic strategies for Cd-induced central nervous system disorders.

Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC

DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6  ×  6  ×  6 m 3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.

Significant contribution of lightning NOx to summertime surface O3 on the Tibetan Plateau

Lightning generates nitrogen oxides (NO_x) in the troposphere, an important precursor of tropospheric ozone (O₃). The Tibetan Plateau (TP) is considered to be a global atmospheric background location with limited anthropogenic influences. However, the observed summertime surface O₃ concentration on the TP is 25% higher than that in highly polluted regions (e.g., southern China). Previous studies have suggested that lightning-produced NO_x (LNO_x) can affect the concentration of surface O₃. We used the Weather Research and Forecasting coupled with chemistry (WRF-Chem) model combined with satellite, ground-based, and airborne observations to evaluate the contribution of LNO_x to the surface O₃ budget on the TP. Our results showed that LNO_x contributed approximately 15% of the surface NO_x emission on the TP in summer. Accordingly, the contribution of LNO_x to the summertime surface daily maximum 8-h average (MDA8) O₃ on the TP was 9.3 ± 7.1 ppb, which was 17.5% ± 14.5% of the total concentration of the surface MDA8 O₃. In addition, our study found that the number of moles of NO produced per lightning flash (LNO_x production efficiency) significantly affected the surface concentration of NO_x, OH, and MDA8 O₃. Increasing the LNO_x production efficiency (PE) from 0 to 330 mol NO flash^-1 increased the concentration of MDA8 O₃ by up to 20% on the TP. Our study revealed that lightning significantly affects the atmospheric chemical processes involving O₃ on the TP.

Role of Nrf2 Nucleus Translocation in Beauvericin-Induced Cell Damage in Rat Hepatocytes

Beauvericin (BEA), a food-borne mycotoxin metabolite derived from the fungus Beauveria Bassiana, is proven to exhibit high hepatotoxicity. However, the molecular mechanism underlying BEA-induced liver damage is not fully understood. Herein, the effect of Nrf2 nuclear translocation-induced by BEA in hepatocytes was investigated. CCK8 solution was used to determine the appropriate concentrations of BEA (0, 1, 1.5 and 2 μmol/L), and BRL3A cells were then exposed to different concentrations of BEA for 12 h. Our results reveal that BEA exposure is associated with high cytotoxicity, lowered cell viability, damaged cellular morphology, and increased apoptosis rate. BEA could lead to oxidative damage through the overproduction of ROS and unbalanced redox, trigger the activation of Nrf2 signaling pathway and Nrf2 nuclear translocation for transcriptional activation of downstream antioxidative genes. Additionally, BEA treatment upregulated the expression of autophagy-related proteins (LC3, p62, Beclin1, and ATG5) indicating a correlation between Nrf2 activation and autophagy, which warrants further studies. Furthermore, ML385, an Nrf2 inhibitor, partially ameliorated BEA-induced cell injury while CDDO, an Nrf2 activator, aggravated liver damage. The present study emphasizes the role of Nrf2 nuclear translocation in BEA-induced oxidative stress associated with the hepatotoxic nature of BEA.

ZEA and DON inhibited inflammation after L. monocytogenes infection and induced ribosomal hyperfunction

The complex microbial community in food environment is a major problem of human or animal health and safety. Mycotoxins and food-borne bacteria can both induce inflammation in the body and cause a series of changes in biological functions. In this study, mice were gavaged with low doses of ZEA, DON, or ZEA + DON, and then infected with L. monocytogenes. A cytokine microarray, including 40 inflammation-related serum cytokines, and proteomics were used to verify the effects of ZEA, DON, and ZEA + DON on the host inflammation and biological function after L. monocytogenes infection. The results showed that mononucleosis after bacterial infection was inhibited by ZEA, DON, and ZEA + DON, while the balance of macrophage differentiation was shifted toward M2-type. ZEA, DON, and ZEA + DON decreased the levels of serum proinflammatory cytokines IL-1β and IL-12 after infection. In addition, the signal of the NF-κB pathway was inhibited. Proteomic results showed that ZEA, DON, and ZEA + DON led to biological dysfunction in ribosomal and metabolic cells, primarily leading to abnormal ribosomal hyperfunction. This study showed that ZEA, DON, and ZEA + DON can aggravate disease progression by inhibiting the inflammatory response following foodborne bacterial infection. These metabolites may also disrupt normal biological functions, which may lead to ribosomal hyperfunction, making bacterial clearance more difficult.

Influence of NOX, Cl, and Br on the upper core of the ozone valley over the Tibetan Plateau during summer: Simulations with a box model

The ozone valley (OV) in the upper troposphere-lower stratosphere (UTLS) over the Tibetan Plateau (TP) has been identified since the 1990s during boreal summer. Recent studies have shown that another upper core of the OV appeared in the middle and upper stratosphere (10-2 hPa); however, the formation mechanism of the OV in the upper stratosphere remains unclear. In this paper, Microwave Limb Sounder (MLS) data from the Aura satellite and the stratospheric heterogeneous chemical reaction box model are used to investigate the impact of chemical substances, including NO, NO₂, Cl and Br, on the ozone valley in the middle and upper stratosphere over the TP. The results show that the formation mechanism of the diurnal and nighttime variation in the upper core of the OV over the TP in the summer may be related to the different daytime and nighttime distributions of NO₂ and the difference in daytime and nighttime average temperatures between the TP and the same latitude regions.

Puerarin alleviates cadmium-induced oxidative damage to bone by reducing autophagy in rats

Autophagy is a regulatory mechanism involved in cadmium (Cd)-induced bone toxicity and is suppressed by various stimuli, including oxidative stress. Puerarin is an isoflavonoid compound isolated from Pueraria, a plant used in traditional Chinese medicine. The underlying mechanisms of action of puerarin remain unclear. The objective of this study was to explore the mitigating effects of puerarin on cadmium-induced oxidative damage in the bones of rats. Cadmium exposure increased oxidative damage in rat bones; this was markedly decreased by puerarin treatment, as demonstrated by changes in the activity of antioxidative enzymes. Cadmium-induced blockage of the expression of key bone regulatory proteins, autophagy-related markers, and signaling molecules was also alleviated by puerarin treatment. Additionally, cadmium reduced expression of the autophagic protein Rab7 and of late endosomal/lysosomal adaptor and MAPK and mTOR activator 1 (LAMTOR1); the decrease in these proteins was not restored by puerarin treatment. We speculate that puerarin relieves the inhibition of fusion of autophagosomes with lysosomes that is induced by cadmium; however, this specific effect of puerarin and downstream effects on bone regulatory mechanisms require further investigation. In conclusion, puerarin alleviates cadmium-induced oxidative damage in the bones of rats by attenuating autophagy, which is likely associated with the antioxidant activity of puerarin.

Puerarin alleviates cadmium-induced mitochondrial mass decrease by inhibiting PINK1-Parkin and Nix-mediated mitophagy in rat cortical neurons

Cadmium (Cd) has well-known central nervous system toxicity, and mitochondria are direct targets of Cd-induced neuronal toxicity. However, how Cd induces mitochondrial mass decrease in terms of its neurotoxic effects remains unknown. Puerarin, an isoflavone extracted from kudzu root, can cross the blood-brain barrier and exert protective effects in nervous system disease. The purpose of the study was to determine the mechanism of Cd-induced mitochondrial mass decrease and the protective role of puerarin in rat cortical neurons. The results indicated that Cd induced mitochondrial mass decrease by activating mitophagy mediated by the PTEN-induced putative kinase protein 1 (PINK1)-E3 ubiquitin ligase (Parkin) and Nip3-like protein X (Nix) pathways in rat cortical neurons. Puerarin improved the Cd-induced decrease in mitochondrial membrane potential (MMP) in vitro, and blocked PINK1-Parkin and Nix-mediated mitophagy, inhibiting Cd-induced mitochondrial mass decrease in rat cortical neurons in vitro and in vivo. In summary, our data clearly indicated that puerarin protects rat cortical neurons against Cd-induced neurotoxicity by ameliorating mitochondrial damage, inhibiting mitophagy-mediated mitochondrial mass decrease. Puerarin appears to have great potential as a neuroprotective agent.

The role of DRP1- PINK1-Parkin-mediated mitophagy in early cadmium-induced liver damage

Cadmium (Cd) is an important environmental pollutant that causes varying degrees of damage to multiple systems of the body. However, the specific mechanism of Cd-induced liver mitophagy remains unclear. In the present study, 5-week-old BALB/c mice and a mouse liver parenchyma cell line (AML12) were studied using a combination of in vivo and in vitro studies. We found that Cd damaged liver cells, destroy the structure and function of mitochondria, and increased the production of superoxide anions. This study further examined the effect of Cd on mitochondrial dynamics and mitophagy and showed that Cd increased mitochondrial division and induced mitophagy. The PINK1-Parkin pathway is a classical mitophagy pathway. Cd-induced mitophagy was inhibited after significantly knocking down Pink1. Mdivi-1 can effectively inhibit mitochondrial division. In this study, Mdivi-1 inhibited the expression of DRP1 and significantly inhibited the occurrence of mitophagy induced by Cd. We further examined the effect of Cd on mitophagy flux. Cd did not increase lysosomal colocalization with mitochondria. In summary, Cd increase the level of oxidative stress, destroy the structure and function of mitochondria, destroy the homeostasis of mitochondrial division and fusion, induce mitophagy through the PINK1-Parkin pathway. Mitophagy plays a protective role in early cadmium-induced liver damage.

MiR-155 promotes cadmium-induced autophagy in rat hepatocytes by suppressing Rheb expression

Cadmium is an environmental pollutant that threatens the health of both humans and animals. Current studies have shown that while hepatotoxic damage induced by cadmium is closely related to autophagy, its intrinsic mechanism has not been elucidated. MicroRNA plays a regulatory role on different stages of autophagy. In this study, we investigated the mechanisms by which microRNA-155 (miR-155) regulate cadmium-induced hepatotoxicity in rat hepatocytes (BRL 3A cells) and in vivo. We found that cadmium exposure could cause liver injury in rats, resulting in a decreased liver index, increased alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activity, hepatocyte steatosis, and ultrastructure damage. Cadmium exposure also induced autophagy in hepatocytes, resulting in increased expression of ATG5, Belin1, LC3II, and an increased number of autophagosomes. In addition, cadmium exposure upregulated miR-155 expression, downregulated Rheb mRNA expression, and downregulated the level of protein expression in the Rheb/mTOR signaling pathway in rat hepatocytes. The overexpression of miR-155 followed by cadmium exposure upregulated the level of autophagy in BRL3A cells, whereas miR-155 inhibition had the opposite effect. In addition, miR-155 negatively regulated Rheb. A dual-luciferase reporter assay verified the negative regulatory effect of miR-155 on Rheb targeting. Knockdown of Rheb downregulated cadmium-induced autophagy. Therefore, the Rheb/mTOR signaling can negatively regulate autophagy. The present study demonstrates that miR-155 promotes cadmium-induced autophagy in rat hepatocytes by suppressing Rheb expression.

Zearalenone Exposure Disrupts Blood-Testis Barrier Integrity through Excessive Ca2+-Mediated Autophagy

Zearalenone (ZEA), a common mycotoxin in grains and animal feeds, has been associated with male reproductive disorders. However, the potential toxicity mechanism of ZEA is not fully understood. In this study, in vivo and in vitro models were used to explore the effects of ZEA on the blood-testis barrier (BTB) and related molecular mechanisms. First, male BALB/C mice were administered ZEA orally (40 mg/kg·bw) for 5-7 d. Sperm motility, testicular morphology, and expressions of BTB junction proteins and autophagy-related proteins were evaluated. In addition, TM4 cells (mouse Sertoli cells line) were used to delineate the molecular mechanisms that mediate the effects of ZEA on BTB. Our results demonstrated that ZEA exposure induced severe testicular damage in histomorphology and an ultrastructural, time-dependent decrease in the expression of blood-testis barrier junction-related proteins, accompanied by an increase in the expression of autophagy-related proteins. Additionally, similar to the in vitro results, the dose-dependent treatment of ZEA increased the level of cytoplasmic Ca²⁺ and the levels of the autophagy markers LC3-II and p62, in conjunction with a decrease in the BTB junction proteins occludin, claudin-11, and Cx43, with the dislocation of the gap junction protein Cx43. Meanwhile, inhibition of autophagy by CQ and 3-MA or inhibition of cytoplasmic Ca²⁺ by BAPTA-AM was sufficient to reduce the effects of ZEA on the TM4 cell BTB. To summarize, this study emphasizes the role of Ca²⁺-mediated autophagy in ZEA-induced BTB destruction, which deepens our understanding of the molecular mechanism of ZEA-induced male reproductive disorders.

Cadmium induces endosomal/lysosomal enlargement and blocks autophagy flux in rat hepatocytes by damaging microtubules

Acute exposure to cadmium (Cd) causes vacuolar degeneration in buffalo rat liver 3 A (BRL 3 A) cells. The present study aimed to determine the relationship between Cd-induced microtubule damage and intracellular vacuolar degeneration. Western blotting results showed that Cd damaged the microtubule network and downregulated the expression of microtubule-associated proteins-kinesin-1 heavy chain (KIF5B), γ-tubulin, and acetylated α-tubulin in BRL 3 A cells. Immunofluorescence staining revealed that Cd inhibited interactions between α-tubulin and microtubule-associated protein 4 (MAP4) as well as KIF5B. Increasing Cd concentrations decreased the levels of the lipid kinase, PIKfyve, which regulates the activity of endosome-lysosome fission. Immunofluorescence and transmission electron microscopy revealed vacuole-like organelles that were late endosomes and lysosomes. The PIKfyve inhibitor, YM201636, and the microtubule depolymerizer, nocodazole, aggravated Cd-induced endosome-lysosome enlargement. Knocking down the kif5b gene that encodes KIF5B intensified the enlargement of endosome-lysosomes and expression of early endosome antigen 1 (EEA1), Ras-related protein Rab-7a (RAB7), and lysosome-associated membrane glycoprotein 2 (LAMP2). Nocodazole, YM201636, and the knockdown of kif5b blocked autophagic flux. We concluded that Cd-induced damage to the microtubule network is the main reason for endosome-lysosome enlargement and autophagic flux blockage in BRL 3 A cells, and kinesin-1 plays a critical role in this process.

Search for Active-Sterile Antineutrino Mixing Using Neutral-Current Interactions with the NOvA Experiment

This Letter reports results from the first long-baseline search for sterile antineutrinos mixing in an accelerator-based antineutrino-dominated beam. The rate of neutral-current interactions in the two NOvA detectors, at distances of 1 and 810 km from the beam source, is analyzed using an exposure of 12.51×10^{20} protons-on-target from the NuMI beam at Fermilab running in antineutrino mode. A total of 121 of neutral-current candidates are observed at the far detector, compared to a prediction of 122±11(stat.)±15(syst.) assuming mixing only between three active flavors. No evidence for ν[over ¯]_{μ}→ν[over ¯]_{s} oscillation is observed. Interpreting this result within a 3+1 model, constraints are placed on the mixing angles θ_{24}<25° and θ_{34}<32° at the 90% C.L. for 0.05  eV^{2}≤Δm_{41}^{2}≤0.5  eV^{2}, the range of mass splittings that produces no significant oscillations at the near detector. These are the first 3+1 confidence limits set using long-baseline accelerator antineutrinos.

Activated AMPK promoted the decrease of lactate production in rat Sertoli cells exposed to Zearalenone

Zearalenone, which is ubiquitous in grains and animal feed, is a mycotoxin that can cause serious damage to animals and humans. Sertoli cells (SCs) can be used to study ZEA male reproductive toxicity in vitro. SCs provide energy for germ cells, where AMPK regulates intracellular energy. In order to explore the regulatory effect of AMPK on ZEA-induced lactate decline, we activated AMPK by AICAR and then inhibited AMPK by Compound C with ZEA-treated SCs for 24 h to detect intracellular lactate production-related indicators. Cell viability in the presence of 20 μmol/L ZEA and either 50 μmol/L AICAR or 5 μmol/L Compound C, respectively, did not damage SCs, and could effectively either activate or inhibit AMPK. Inhibition of AMPK promoted the production of pyruvate and lactate via increased expression of the glycolysis-related genes Pgam1 and the lactate production-related proteins GLUT1, LDHA, and MCT4. Activating AMPK inhibited the production of lactate and pyruvate by suppressing the expression of glycolysis-related genes HK1, Pgam1, and Gpi1 and that of lactate production-related proteins LDHA and MCT4. Zearalenone destroys the energy balance in SCs, activates P-AMPK, which inhibit the production of lactate and pyruvate in SCs. This also leads to the decrease of energy supply of SCs to spermatogenic cells, damages to reproductive system.

Zearalenone and deoxynivalenol reduced Th1-mediated cellular immune response after Listeria monocytogenes infection by inhibiting CD4+ T cell activation and differentiation

Based on the fact that mycotoxins and the food-borne bacteria coexist in the natural environment and pose a significant health hazard to humans and animals, it is important to investigate the immunosuppressive mechanism of ZEA (zearalenone), DON (deoxynivalenol), and their combination in bacterial infections. In this study, we established a mouse model of mycotoxin low-dose exposure combined with Listeria monocytogenes infection and investigated the effects of ZEA, DON and their combination on Th1-mediated anti-intracellular bacterial infection based on CD4⁺ T cell activation and differentiation using both in vitro and in vivo analyses. The present study showed that both ZEA and DON aggravated Listeria monocytogenes infection in mice and affected the activation of CD4⁺ T cells and Th1 differentiation, including the effects on costimulatory molecules CD28 and CD152 and on cross-linking of IL-12 and IL-12R, by inhibiting T cell receptor (TCR) signaling. When compared with ZEA, DON was found to have a greater impact on many related indicators. Surprisingly, the combined effects of ZEA and DON did not appear to enhance toxicity compared to treatment with the individual mycotoxins. Our findings more clearly revealed that exposure to low-dose ZEA and DON caused immunosuppression in the body by mechanisms including inhibition of CD4⁺ T cells activation and reduction of Th1 cell differentiation, thus exacerbating infection of animals by Listeria monocytogenes.