RESUMEN
Hexavalent chromium [Cr(VI)] exists widely in occupational environments. The mechanistic target of rapamycin (mTOR) has been well-documented to regulate autophagy negatively. However, we found that low concentration of Cr(VI) (0.2 µM) elevated both mTOR and autophagy and promote cell survival. Conversely, high concentration of Cr(VI) (6 µM) caused cell death by inhibiting mTOR and subsequently inducing autophagy. Tunicamycin (Tm), as an Endoplasmic reticulum (ER) stress activator was used to induce mild ER stress at 0.1 µg/ml and it activated both autophagy and mTOR, which also caused cell migration in a similar manner to that observed with low concentration of Cr(VI). Severe ER stress caused by Tm (2 µg/ml) decreased mTOR, increased autophagy and then inhibited cell migration, which was the same as 6 µM Cr(VI) treatment, although Cr(VI) in high concentration inhibited ER stress. Activating transcription factor 4 (ATF4), a downstream target of ER stress, only increased under mild ER stress but decreased under severe ER stress and 6 µM Cr(VI) treatment. Chromatin immunoprecipitation (ChIP) experiment indicated that ATF4 could bind to the promoter of ATG4B and AKT1. To sum up, our data revealed that mild ER stress induced by low concentration of Cr(VI) could enhance transcriptional regulation of ATG4B and AKT1 by ATF4, which induced both autophagy and mTOR to promote cell viability.
Asunto(s)
Factor de Transcripción Activador 4 , Autofagia , Cromo , Estrés del Retículo Endoplásmico , Serina-Treonina Quinasas TOR , Estrés del Retículo Endoplásmico/efectos de los fármacos , Cromo/toxicidad , Autofagia/efectos de los fármacos , Serina-Treonina Quinasas TOR/metabolismo , Factor de Transcripción Activador 4/metabolismo , Humanos , Movimiento Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Tunicamicina/farmacología , Tunicamicina/toxicidadRESUMEN
Cr(VI) is known to be seriously toxic and carcinogenic. Hypoxia-inducible factor-1α (HIF-1α) is a crucial regulator to promote tumor development. In this study, we found that Cr(VI) significantly increased the expression of HIF-1α in A549 cells and in lung of BALB/c mice but not in HELF cells. Treatment with Lificiguat (YC-1), HIF-1α inhibitor, or CoCl2, HIF-1α inducer, could alter Cr(VI)-induced autophagy, glycolysis, and cell growth in A549 cells but not in HELF cells, validating the involvement of HIF-1α in these effects of Cr(VI) in A549 cells. Co-treatments of pcATG4B with YC-1, or siATG4B with CoCl2 demonstrated the role of HIF-1α / autophagy axis in inducing glycolysis and cell growth in A549 cells. In HELF cells, however, only autophagy but not HIF-1α played a role in inducing glycolysis. The protein level of p53 was significantly lower in A549 cells than in HELF cells. RITA, a p53 inducer, attenuated Cr(VI)-induced HIF-1α and LC3-II in A549 cells, suggesting that p53 might be the mechanism underlying the different effects of Cr(VI) on HIF-1α in A549 and HELF cells. Thus, p53-dependent HIF-1α / autophagy-mediated glycolysis plays a role in facilitating Cr(VI)-induced carcinogenesis.
Asunto(s)
Carcinogénesis , Cromo , Cobalto , Proteína p53 Supresora de Tumor , Animales , Ratones , Proteína p53 Supresora de Tumor/genética , Autofagia , Movimiento Celular , Glucólisis , Línea Celular TumoralRESUMEN
Perfluorooctane sulfonate (PFOS), an officially listed persistent organic pollutant, is a widely distributed perfluoroalkyl substance. Epidemiological studies have shown that PFOS is intimately linked to the occurrence of insulin resistance (IR). However, the detailed mechanism remains obscure. In previous studies, we found that mitochondrial calcium overload was concerned with hepatic IR induced by PFOS. In this study, we found that PFOS exposure noticeably raised lysosomal calcium in L-02 hepatocytes from 0.5â¯h. In the PFOS-cultured L-02 cells, inhibiting autophagy alleviated lysosomal calcium overload. Inhibition of mitochondrial calcium uptake aggravated the accumulation of lysosomal calcium, while inhibition of lysosomal calcium outflowing reversed PFOS-induced mitochondrial calcium overload and IR. Transient receptor potential mucolipin 1 (TRPML1), the calcium output channel of lysosomes, interacted with voltage-dependent anion channel 1 (VDAC1), the calcium intake channel of mitochondria, in the PFOS-cultured cells. Moreover, we found that ATP synthase F1 subunit beta (ATP5B) interacted with TRPML1 and VDAC1 in the L-02 cells and the liver of mice under PFOS exposure. Inhibiting ATP5B expression or restraining the ATP5B on the plasma membrane reduced the interplay between TRPML1 and VDAC1, reversed the mitochondrial calcium overload and deteriorated the lysosomal calcium accumulation in the PFOS-cultured cells. Our research unveils the molecular regulation of the calcium crosstalk between lysosomes and mitochondria, and explains PFOS-induced IR in the context of activated autophagy.
Asunto(s)
Ácidos Alcanesulfónicos , Autofagia , Calcio , Fluorocarburos , Resistencia a la Insulina , Hígado , Lisosomas , Mitocondrias , ATPasas de Translocación de Protón Mitocondriales , Ácidos Alcanesulfónicos/toxicidad , Fluorocarburos/toxicidad , Animales , Lisosomas/efectos de los fármacos , Lisosomas/metabolismo , Autofagia/efectos de los fármacos , Calcio/metabolismo , Ratones , ATPasas de Translocación de Protón Mitocondriales/metabolismo , Hígado/efectos de los fármacos , Hígado/metabolismo , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Masculino , Canal Aniónico 1 Dependiente del Voltaje/metabolismo , Línea Celular , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Contaminantes Ambientales/toxicidad , Canales Catiónicos TRPM/metabolismo , Ratones Endogámicos C57BLRESUMEN
Perfluorooctane sulfonate (PFOS) is known as a persistent organic pollutant. A significant correlation between PFOS and liver ferroptosis has been unveiled, but the precise mechanism needs to be elucidated. In prior research, we found that PFOS treatment provoked mitochondrial iron overload. In this study, we observed a gradual increase in lysosomal iron in L-O2 cells after exposure to PFOS for 0.5-24â¯h. In PFOS-exposed L-O2 cells, suppressing autophagy relieved the lysosomal iron overload. Inhibiting transient receptor potential mucolipin 1 (TRPML1), a calcium efflux channel on the lysosomal membrane, led to a further rise in lysosomal iron levels and decreased mitochondrial iron overload during PFOS treatment. Suppressing VDAC1, a subtype of voltage-dependent anion-selective channels (VDACs) on the outer mitochondrial membrane, had no impact on PFOS-triggered mitochondrial iron overload, whereas restraining VDAC2/3 relieved this condition. Although silencing VDAC2 relieved PFOS-induced mitochondrial iron overload, it had no effect on PFOS-triggered lysosomal iron overload. Silencing VDAC3 alleviated PFOS-mediated mitochondrial iron overload and led to an additional increase in lysosomal iron. Therefore, we regarded VDAC3 as the specific VDACs subtype that mediated the lysosomes-mitochondria iron transfer. Additionally, in the presence of PFOS, an enhanced association between TRPML1 and VDAC3 was found in mice liver tissue and L-O2 cells. Our research unveils a novel regulatory mechanism of autophagy on the iron homeostasis and the effect of TRPML1-VDAC3 interaction on lysosomes-mitochondria iron transfer, giving an explanation of PFOS-induced ferroptosis and shedding some light on the role of classic calcium channels in iron transmission.
RESUMEN
As a persistent organic pollutant, perfluorooctane sulfonate (PFOS) has a serious detrimental impact on human health. It has been suggested that PFOS is associated with liver inflammation. However, the underlying mechanisms are still unclear. Here, PFOS was found to elevate the oligomerization tendency of voltage-dependent anion channel 1 (VDAC1) in the mice liver and human normal liver cells L-02. Inhibition of VDAC1 oligomerization alleviated PFOS-induced nucleotide-binding domain and leucine-rich repeat protein-3 (NLRP3) inflammasome activation. Cytoplasmic membrane VDAC1 translocated to mitochondria was also observed in response to PFOS. Therefore, the oligomerization of VDAC1 occurred mainly in the mitochondria. VDAC1 was found to interact with the ATP synthase beta subunit (ATP5B) under PFOS treatment. Knockdown of ATP5B or immobilization of ATP5B to the cytoplasmic membrane alleviated the increased VDAC1 oligomerization and NLRP3 inflammasome activation. Therefore, our results suggested that PFOS induced NLRP3 inflammasome activation through VDAC1 oligomerization, a process dependent on ATP5B to transfer VDAC1 from the plasma membrane to the mitochondria. The findings offer novel perspectives on the activation of the NLRP3 inflammasome, the regulatory mode on VDAC1 oligomerization, and the mechanism of PFOS toxicity.
Asunto(s)
Ácidos Alcanesulfónicos , Fluorocarburos , Inflamasomas , Proteína con Dominio Pirina 3 de la Familia NLR , Canal Aniónico 1 Dependiente del Voltaje , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Animales , Ácidos Alcanesulfónicos/toxicidad , Inflamasomas/metabolismo , Inflamasomas/efectos de los fármacos , Canal Aniónico 1 Dependiente del Voltaje/metabolismo , Canal Aniónico 1 Dependiente del Voltaje/genética , Fluorocarburos/toxicidad , Humanos , Ratones , ATPasas de Translocación de Protón Mitocondriales/metabolismo , Línea Celular , Ratones Endogámicos C57BL , Hígado/efectos de los fármacos , Hígado/metabolismo , Contaminantes Ambientales/toxicidad , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismoRESUMEN
The incidence of nonalcoholic steatohepatitis (NASH) is related with perfluorooctane sulfonate (PFOS), yet the mechanism remains ill-defined. Mounting evidence suggests that ferroptosis plays a crucial role in the initiation of NASH. In this study, we used mice and human hepatocytes L-02 to investigate the role of ferroptosis in PFOS-induced NASH and the effect and molecular mechanism of PFOS on liver ferroptosis. We found here that PFOS caused NASH in mice, and lipid accumulation and inflammatory response in the L-02 cells. PFOS induced hepatic ferroptosis in vivo and in vitro, as evidenced by the decrease in glutathione peroxidase 4 (GPX4), and the increases in cytosolic iron, acyl-CoA synthetase long-chain family member 4 (ACSL4) and lipid peroxidation. In the PFOS-treated cells, the increases in the inflammatory factors and lipid contents were reversed by ferroptosis inhibitor. PFOS-induced ferroptosis was relieved by autophagy inhibitor. The expression of mitochondrial calcium uniporter (MCU) was accelerated by PFOS, leading to subsequent mitochondrial calcium accumulation, and inhibiting autophagy reversed the increase in MCU. Inhibiting mitochondrial calcium reversed the variations in GPX4 and cytosolic iron, without influencing the change in ACSL4, induced by PFOS. MCU interacted with ACSL4 and the siRNA against MCU reversed the changes in ACSL4ï¼GPX4 and cytosolic iron systemically. This study put forward the involvement of hepatic ferroptosis in PFOS-induced NASH and identified MCU as the mediator of the autophagy-dependent ferroptosis.
Asunto(s)
Ácidos Alcanesulfónicos , Autofagia , Calcio , Coenzima A Ligasas , Ferroptosis , Fluorocarburos , Enfermedad del Hígado Graso no Alcohólico , Ferroptosis/efectos de los fármacos , Fluorocarburos/toxicidad , Animales , Ácidos Alcanesulfónicos/toxicidad , Ratones , Enfermedad del Hígado Graso no Alcohólico/inducido químicamente , Enfermedad del Hígado Graso no Alcohólico/patología , Autofagia/efectos de los fármacos , Coenzima A Ligasas/metabolismo , Humanos , Calcio/metabolismo , Canales de Calcio/metabolismo , Masculino , Ratones Endogámicos C57BL , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Línea Celular , Hepatocitos/efectos de los fármacosRESUMEN
The hydrolysis of extracellular polymeric substances (EPS) represents a critical bottleneck in the anaerobic fermentation of waste activated sludge (WAS), while tryptophan is identified as an underestimated constituent of EPS. Herein, we harnessed a tryptophan-degrading microbial consortium (TDC) to enhance the hydrolysis efficiency of WAS. At TDC dosages of 5%, 10%, and 20%, a notable increase in SCOD was observed by factors of 1.13, 1.39, and 1.88, respectively. The introduction of TDC improved both the yield and quality of short chain fatty acids (SCFAs), the maximum SCFA yield increased from 590.6 to 1820.2, 1957.9 and 2194.9 mg COD/L, whilst the acetate ratio within SCFAs was raised from 34.1% to 61.2-70.9%. Furthermore, as TDC dosage increased, the relative activity of protease exhibited significant increments, reaching 116.3%, 168.0%, and 266.1%, respectively. This enhancement facilitated WAS solubilization and the release of organic substances from bound EPS into soluble EPS. Microbial analysis identified Tetrasphaera and Soehngenia as key participants in WAS solubilization and the breakdown of protein fraction. Metabolic analysis revealed that TDC triggered the secretion of enzymes associated with amino acid metabolism and fatty acid biosynthesis, thereby fostering the decomposition of proteins and production of SCFAs.
Asunto(s)
Aguas del Alcantarillado , Triptófano , Humanos , Fermentación , Aguas del Alcantarillado/química , Anaerobiosis , Triptófano/metabolismo , Ácidos Grasos Volátiles/metabolismo , Concentración de Iones de HidrógenoRESUMEN
The volatile oils are the effective components of Agastache rugosa, which are stored in the glandular scale. The leaves of pulegone-type A. rugosa were used as materials to observe the leaf morphology of A. rugosa at different growth stages, and the components of volatile oils in gland scales were detected by GC-MS. At the same time, qRT-PCR was used to determine the relative expression of key enzyme genes in the biosynthesis pathway of monoterpenes in volatile oils. The results showed that the density of A. rugosa glandular scale decreased first and then tended to be stable. With the growth of leaves, the relative content of pulegone decreased from 79.26% to 3.94%(89.97%-41.44%), while that of isomenthone increased from 2.43% to 77.87%(0.74%-51.01%), and the changes of other components were relatively insignificant. The correlation analysis between the relative content of monoterpenes and the relative expression levels of their key enzyme genes showed that there was a significant correlation between the relative content of menthone and isomenthone and the relative expression levels of pulegone reductase(PR)(r>0.6, P<0.01). To sum up, this study revealed the accumulation rules of the main components of the contents of the glandular scale of A. rugosa and the expression rules of the key enzyme genes for biosynthesis, which provided a scientific basis and data support for determining the appropriate harvesting period and quality control of the medicinal herbs. This study also initially revealed the biosynthesis mechanism of the monoterpenes mainly composed of pulegone and isomenthone in A. rugosa, laying a foundation for further research on the molecular mechanism of synthesis and accumulation of monoterpenes in A. rugosa.
Asunto(s)
Agastache , Monoterpenos Ciclohexánicos , Aceites Volátiles , Aceites Volátiles/análisis , Agastache/metabolismo , Monoterpenos/metabolismoRESUMEN
Research indicates that particulate matter with an aerodynamic equivalent diameter of less than or equal to 2.5 µm in ambient air may induce lung cancer progression. Circular RNAs are a special kind of endogenous noncoding RNA, and their functions are reflected in various diseases and physiological processes, but there are still few studies related to PM2.5-induced lung cancer. Here, we identified that circCDR1as was upregulated in lung cancer cells stimulated with PM2.5 and positively correlated with the malignant features of lung cancer. The lower expression of CircCDR1as reduced the adverse progression of lung cancer cells after PM2.5 treatment; the lower expression of circCDR1as impaired the growth size and metastatic ability of lung cancer cells in mouse tumour models. Mechanistically, circCDR1as specifically bound to serine/arginine-rich splicing Factor 1 (SRSF1) and affected the splicing of vascular endothelial growth factor-A (VEGFA) by SRSF1. Furthermore, circCDR1as affected SRSF1 function by regulating PARK2-mediated SRSF1 ubiquitination, protein production and degradation. CircCDR1as also affected C-myc and cyclin D1 expression by regulating SRSF1 and affecting the wnt/ß-catenin signalling pathway, ultimately promoting malignant behavior and inhibiting the apoptosis of lung cancer cells, thereby causing PM2.5-induced lung cancer development.
Asunto(s)
Neoplasias Pulmonares , Material Particulado , ARN Circular , Factores de Empalme Serina-Arginina , Animales , Ratones , Modelos Animales de Enfermedad , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Material Particulado/toxicidad , Factor A de Crecimiento Endotelial Vascular/genética , ARN Circular/metabolismo , Factores de Empalme Serina-Arginina/metabolismo , Ciclina D1/genética , Ciclina D1/metabolismo , Células A549 , HumanosRESUMEN
Hexavalent chromium [Cr (VI)] is a well-established carcinogen. Cr (VI)-treated cells are phenotypically characterized by aberrant levels of growth and migration. Curcumin, a polyphenolic compound from the plant turmeric, has been found to possess antiproliferation, anti-inflammation, and antioxidant properties. In this study, the effect of curcumin on Cr (VI)-induced cell survival and migration and the underlying mechanism were investigated. Cell viability assay on A549 and human embryonic lung fibroblast cells showed that curcumin at the concentration of 10 µM could significantly attenuate Cr (VI)-induced viability in both cell lines. Following Western blot assay and metabolomics assays, cotreatment with curcumin and Cr (VI) resulted in the suppression of Cr (VI)-induced glycolysis-, autophagy-, and migration-related proteins. Meanwhile, curcumin increased Cr (VI)-reduced oxidative phosphorylation (OXPHOS)-related proteins, COXIV and ND1. Moreover, curcumin suppressed Cr (VI)-induced mitochondrial dysfunction, mitochondrial mass decrease, and mitochondrial membrane potential loss. Treatment with curcumin for 24 h significantly attenuated pcATG4B-induced autophagy and the subsequent expression of glucose transporter 1, hexokinase II, and pyruvate kinase M2. Wound healing and transwell assay demonstrated that curcumin reduced Cr (VI)-induced cell migration. Taken together, these results showed that curcumin was able to attenuate Cr (VI)-induced cell viability and migration by targeting autophagy-dependent reprogrammed metabolism from OXPHOS to glycolysis.
Asunto(s)
Curcumina , Humanos , Curcumina/farmacología , Autofagia , Potencial de la Membrana Mitocondrial , Mitocondrias , Ciclo CelularRESUMEN
Hexavalent chromium [Cr (VI)] exists environmentally and occupationally. It has been shown to pose a carcinogenic hazard in certain occupations. This study was to investigate the role of high mobility group A2 (HMGA2) in Cr (VI)-induced metabolism reprogramming from oxidative phosphorylation (OXPHOS) to glycolysis in A549 and HELF cells. First, knockdown of HMGA2 by siHMGA2 significantly attenuated Cr (VI)-reduced expression of OXPHOS-related proteins (COX IV and ND1) and mitochondrial mass, indicating that HMGA2 was involved in Cr (VI)-reduced OXPHOS. Overexpression of HMGA2 by transfection of HMGA2-DNA plasmids reduced the expression of COX IV, ND1 and mitochondrial mass, suggesting the negative role of HMGA2 in OXPHOS. Secondly, both CCCP, the inhibitor of mitochondrial function, and the ER stress inhibitor, 4-phenylbutyric acid (4-PBA), decreased the level of HMGA2, indicating that the interaction of mitochondrial dysfunction and ER stress resulted in Cr (VI)-induced HMGA2 expression. Further study demonstrated that ER stress/HMGA2 axis mediated the metabolism rewiring from OXPHOS to aerobic glycolysis. Notably, Cr (VI) induced the accumulation of HMGA2 proteins in mitochondria and ChIP assay demonstrated that HMGA2 proteins could bind to D-loop region of mitochondrial DNA (mtDNA), which provided the proof for HMGA2-modulating OXPHOS. Taken together, our results suggested that the interaction of mitochondria and ER stress-enhanced HMGA2 played an important role in Cr (VI)-induced metabolic reprogramming from OXPHOS to glycolysis by binding directly to D-loop region of mtDNA. This work informs on the potential mode of action for Cr (VI)-induced tumors and builds on growing evidence regarding the contribution of cellular metabolic disruption contributing to carcinogenicity.
Asunto(s)
Cromo , Mitocondrias , Carbonil Cianuro m-Clorofenil Hidrazona/metabolismo , Cromo/metabolismo , ADN Mitocondrial/genética , Glucólisis , Mitocondrias/metabolismoRESUMEN
Chromium (Cr) compounds are markedly toxic and carcinogenic. Previously, we found that Cr (VI) induced autophagy in A549 cells. Here, the effect of mitochondrial dysfunction and endoplasmic reticulum (ER) stress on inducing mitophagy was investigated in both A549 and H1299 cells. Exposure to Cr (VI) for 6 h significantly enhanced reactive oxygen species (ROS) production and reduced mitochondrial membrane potential (MMP). Transmission electron microscopy showed that Cr (VI) induced mitochondrial morphological changes, such as, mitochondrial swelling and vacuolization. The elevated expression of GRP78 and p-PERK suggested that Cr (VI) resulted in ER stress. Both mitochondrial dysfunction and ER stress played an important role in Cr (VI)-induced mitophagy, as the mitochondrial function inhibitor, carbonyl cyanide 3-chlorophenylhydrazone (CCCP) induced PINK1 and PARK2 and increased the expression of GRP78 and p-PERK while the levels of Cr (VI)-induced PINK1, PARK2, LC3-II were reduced after ER stress inhibitor, phenylbutyric acid (4PBA) pretreatment. When A549 cells were treated with CCCP and 4-PBA simultaneously, CCCP-induced expressions of PINK1, PARK2 and LC3-II decreased significantly compared with that of only CCCP-treated cells, indicating that there was a crosstalk between mitochondria and ER in inducing mitophagy. Additionally, the crosstalk between mitochondrial dysfunction and ER stress modulated the expression of Cr (VI)-induced ATF4, which resulted in mitophagy. Collectively, our data demonstrated that Cr (VI)-induced mitophagy mediated by ATF4 via the crosstalk between ER stress and mitochondrial dysfunction.
Asunto(s)
Estrés del Retículo Endoplásmico , Mitofagia , Cromo/toxicidad , Mitocondrias , Especies Reactivas de OxígenoRESUMEN
Type 2 Diabetes causes learning and memory deficits that might be mediated by hippocampus neuron apoptosis. Studies found that taurine might improve cognitive deficits under diabetic condition because of its ability to prevent hippocampus neuron apoptosis. However, the effect and mechanism is not clear. In this study, we explore the effect and mechanism of taurine on inhibiting hippocampus neuron apoptosis. Sixty male Sprague-Dawley rats were randomly divided into control, T2D, taurine treatment (giving 0.5%, 1%, and 2% taurine in drinking water) groups. Streptozotocin was used to establish the diabetes model. HT-22 cell (hippocampus neurons line) was used for in vitro experiments. Morris Water Maze test was used to check the learning and memory ability, TUNEL assay was used to measure apoptosis and nerve growth factor (NGF); Akt/Bad pathway relevant protein was detected by western blot. Taurine improved learning and memory ability and significantly decreased apoptosis of the hippocampus neurons in T2D rats. Moreover, taurine supplement also inhibited high glucose-induced apoptosis in HT-22 cell in vitro. Mechanistically, taurine increased the expression of NGF, phosphorylation of Trka, Akt, and Bad, as well as reduced cytochrome c release from mitochondria to cytosol. However, beneficial effects of taurine were blocked in the presence of anti-NGF antibody or Akt inhibitor. Taurine could inhibit hippocampus neuron apoptosis via NGF-Akt/Bad pathway. These results provide some clues that taurine might be efficient and feasible candidate for improvement of learning and memory ability in T2D rats.
Asunto(s)
Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Factor de Crecimiento Nervioso/genética , Receptor trkA/genética , Taurina/farmacología , Animales , Apoptosis/efectos de los fármacos , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/patología , Glucosa/metabolismo , Hipocampo/efectos de los fármacos , Hipocampo/patología , Humanos , Aprendizaje por Laberinto , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Proteínas Proto-Oncogénicas c-akt/genética , Ratas , Transducción de Señal , Proteína Letal Asociada a bcl/genéticaRESUMEN
Diabetic peripheral neuropathy is a common complications of Type 2 Diabetes and its main pathological feature is myelin sheath damage of peripheral nerve that was induced by Schwann cells (SCs) apoptosis. Increasing evidence suggested that taurine might play a role in improving DPN because of its ability to prevent SCs apoptosis. In this study, we explore the effect of taurine on preventing SCs apoptosis and its underlying mechanism. Sprague Dawley rats were treated with streptozotocin to establish the diabetes model. Rats were randomly divided into control, diabetes, taurine treatment (as giving 0.5%, 1% and 2% taurine in drinking water) groups. RSC96 cell (a rat SCs line) was used for intervention experiments in vitro. Results showed that taurine significantly corrected morphology of damaged myelin sheath and inhibited SCs apoptosis in sciatic nerve of diabetic rats. Moreover, taurine prevented apoptosis of RSC96â¯cells exposed to high glucose. Mechanistically, taurine up-regulated NGF expression and phosphorylation levels of Akt and GSK3ß, while, blocking activation of NGF and phosphorylation of Akt and GSK3ß increased apoptosis of high glucose-exposed RSC96â¯cells with taurine supplement. These results revealed taurine improved the myelin sheath damage of sciatic nerve in diabetic rats by controlling SCs apoptosis via NGF/Akt/GSK3ß signaling pathways, which provides some clues that taurine might be effective and feasible candidate for the treatment of DPN.
Asunto(s)
Apoptosis/efectos de los fármacos , Neuropatías Diabéticas/patología , Vaina de Mielina/efectos de los fármacos , Sustancias Protectoras/farmacología , Células de Schwann/efectos de los fármacos , Nervio Ciático/efectos de los fármacos , Taurina/farmacología , Animales , Enfermedades Desmielinizantes/patología , Enfermedades Desmielinizantes/prevención & control , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/complicaciones , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/patología , Neuropatías Diabéticas/tratamiento farmacológico , Neuropatías Diabéticas/etiología , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Masculino , Vaina de Mielina/patología , Factor de Crecimiento Nervioso/metabolismo , Sustancias Protectoras/uso terapéutico , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Ratas Sprague-Dawley , Células de Schwann/fisiología , Nervio Ciático/patología , Transducción de Señal/efectos de los fármacos , Estreptozocina , Taurina/uso terapéuticoRESUMEN
Cr (VI) is mutagenic and carcinogenic, but the mechanism is unclear. In this study, the involvement of high mobility group A2 (HMGA2) in Cr (VI)-induced autophagy was investigated. Cr (VI) treatment induced formation of autophagosomes, increased expression of LC3II, Atg12-Atg5, Atg4, Atg10, HMGA1 and HMGA2 proteins, and decreased the expression of p62 in A549 cells. Silencing of HMGA2 gene by siRNA blocked Cr (VI)-induced formation of autophagosomes, expression of LC3II, Atg12-Atg5, Atg10 and reduction of p62. Overexpression of HMGA2 in HEK 293 and HeLa cells could induce the expression of LC3II, Atg12-Atg5 and Atg10, and decrease the expression of p62. Although the protein level of Atg12-Atg5 conjugation changed after Cr (VI) treatment, silencing of HMGA2 and overexpression of HMGA2, both the proteins and mRNA levels of Atg12 and Atg5 were not changed significantly. ChIP assay demonstrated that HMGA2 protein directly bound to the promoter sequence of Atg10 gene, which modulated the conjugation of Atg12-Atg5. Interestingly, 3-MA markedly prevented Cr (VI)-induced cell growth of A549 cells. Our further in vivo study confirmed that the expression of HMGA1, HMGA2, LC3II, Atg12-Atg5, Atg4, Atg5, Atg7, Atg10, Atg12, Beclin 1 were increased and p62 was reduced in lung tissues of Cr (VI)-treated BALB/c mice. Combining, our data demonstrated that HMGA2 plays an important role in Cr (VI)-induced autophagy and the mechanism underlies Atg12-Atg5 conjugation modulated by HMGA2-dependent transcriptional regulation of Atg10. This suggests that HMGA2 might be an important biomarker in Cr (VI)-induced autophagy, cell-growth or other toxicities.
Asunto(s)
Autofagia/efectos de los fármacos , Autofagia/fisiología , Cromo/toxicidad , Proteína HMGA2/metabolismo , Animales , Western Blotting , Línea Celular Tumoral , Regulación de la Expresión Génica , Técnicas de Silenciamiento del Gen , Humanos , Masculino , Ratones , Ratones Endogámicos BALB C , Microscopía Electrónica de Transmisión , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
We hypothesize that citreoviridin (CIT) induces DNA damage in human liver-derived HepG2 cells through an oxidative stress mechanism and that N-acetyl-l-cysteine (NAC) protects against CIT-induced DNA damage in HepG2 cells. CIT-induced DNA damage in HepG2 cells was evaluated by alkaline single-cell gel electrophoresis assay. To elucidate the genotoxicity mechanisms, the level of oxidative DNA damage was tested by immunoperoxidase staining for 8-hydroxydeoxyguanosine (8-OHdG); the intracellular generation of reactive oxygen species (ROS) and reduced glutathione (GSH) were examined; mitochondrial membrane potential and lysosomal membranes' permeability were detected; furthermore, protective effects of NAC on CIT-induced ROS formation and CIT-induced DNA damage were evaluated in HepG2 cells. A significant dose-dependent increment in DNA migration was observed at tested concentrations (2.50-10.00 µM) of CIT. The levels of ROS, 8-OHdG formation were increased by CIT, and significant depletion of GSH in HepG2 cells was induced by CIT. Destabilization of lysosome and mitochondria was also observed in cells treated with CIT. In addition, NAC significantly decreased CIT-induced ROS formation and CIT-induced DNA damage in HepG2 cells. The data indicate that CIT induces DNA damage in HepG2 cells, most likely through oxidative stress mechanisms; that NAC protects against DNA damage induced by CIT in HepG2 cells; and that depolarization of mitochondria and lysosomal protease leakage may play a role in CIT-induced DNA damage in HepG2 cells.
Asunto(s)
Aurovertinas/toxicidad , Daño del ADN , Micotoxinas/toxicidad , Estrés Oxidativo/efectos de los fármacos , 8-Hidroxi-2'-Desoxicoguanosina , Acetilcisteína/farmacología , Desoxiguanosina/análogos & derivados , Glutatión/metabolismo , Células Hep G2 , Humanos , Lisosomas/efectos de los fármacos , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismoRESUMEN
BACKGROUND: Manganese (Mn) is an essential element and a potential toxicant for developing organism. Deficiency and excess of it were both deleterious to fetal growth in experimental animals. However, literature on relationship between Mn status and birth outcome in humans is sparse. METHODS: Mn concentrations were measured in mother whole blood (MWB) and umbilical cord blood (UCB) in 125 pairs of mother-infant; birth size was examined and relationship between them was analysed. Potentially environmental factors influencing Mn loads in maternal and fetal organisms were investigated through epidemiological method. RESULTS: Mn level in UCB was significantly higher than that in MWB (mean value: 54.98 vs. 78.75 µg/L), and a significant positive correlation was shown between them. There was a quadratic curvilinear (inverted U-shaped curve) relationship between MWB Mn and birth size, and between UCB Mn and birth size. Both univariate analysis and multiple linear regression analysis showed that exposure to harmful occupational factors during gestation remarkably increased maternal and fetal Mn levels. Living close to major transportation routes (<500 m) also increased the MWB Mn levels. CONCLUSION: Our results suggested that lower or higher Mn level in maternal and umbilical blood may induce adverse effect on birth size in humans. In addition, increased levels of Mn in MWB or UCB may be associated with exposure to some environmental hazard factors.
Asunto(s)
Peso al Nacer , Exposición a Riesgos Ambientales/efectos adversos , Sangre Fetal/química , Manganeso/análisis , Embarazo/sangre , Adulto , Estatura , China/epidemiología , Estudios Transversales , Femenino , Cabeza/anatomía & histología , Humanos , Recién Nacido , Manganeso/efectos adversos , Tórax/anatomía & histologíaRESUMEN
OBJECTIVE: To study the reference of urinary. cadmium of the general population in rural high background areas of soil cadmium and non-cadmium contaminated in China. METHODS: In rural high background areas of soil cadmium and non-cadmium contaminated, randomly selected non-occupational-cadmium exposed population 1134 people (male 519, female 615) with each gender and age groups, questionnaire surveyed and collected random urine. Urinary cadmium and urinary creatinine (Cr) concentration were tested, excluding urinary Cr <0.3 g/L and >3 g/L. Analyze the impact factors of urinary cadmium and calculated 95% quantile (P,95 ) of urinary cadmium after correction by urinary Cr. RESULTS: Female median urinary cadmium was significantly higher than men, male smokers median urinary cadmium was significantly higher than male non-smokers (P <0. 05) , but differ slightly in P95. Both men and women, the median and P95 of urinary cadmium were low when 15 -30 year-old, and higher when <15 or >30 year-old. According to gender, and 15 -30, <15 and >30 years old, analysis the upper limit of cadmium in urine. The 95% upper limit of urinary cadmium of <15 and >30 year-old female (12.24 microg/gCr) was significantly higher than other populations ( <9.0 microg/gCr). Addition, the 95% upper limit of uriniary cadmium of the survey population exceeded the upper limit (5 microg/gCr) of the occupational cadmium poisoning diagnostic criteria in China (GBZ 17-2002). CONCLUSION: In the two rural high background areas of soil cadmium and non-cadmium polluted , urinary cadmium reference of non-cadmium-occupational-exposed male is <9.0 microg/gCr, and female <13.0 microg/gCr.
Asunto(s)
Cadmio/orina , Exposición a Riesgos Ambientales , Exposición Profesional/efectos adversos , Contaminantes del Suelo/orina , China , Creatinina/orina , Femenino , Sustancias Peligrosas , Humanos , Masculino , Vigilancia de la Población , Valores de Referencia , Población RuralRESUMEN
Cadmium (Cd) exposure significantly increases the risk of lung cancer. The demand for glutamine is increasing in cancers, including lung cancer. In this study, we investigated the role of glutamine metabolism in Cd-induced cell growth and migration. Firstly, we found that 2⯵M Cd-treatment up-regulated the expression of ASCT2 (alanine, serine, cysteine-preferring transporter 2) and ASNS (asparagine synthetase) while downregulating mitochondrial glutaminase GLS1 in A549 cells. The same results were obtained in male BALB/c mice treated with 0.5 and 1â¯mgâ¯Cd/kg body weight. Subsequently, both glutamine deprivation and transfection with siASCT2 revealed that glutamine played a role in Cd-induced cell growth and migration. Furthermore, using 4-PBA (5â¯mM), an inhibitor of endoplasmic reticulum (ER) stress, Tm (0.1⯵g/ml), an inducer of ER stress, siHMGA2, and over-expressing HMGA2 plasmids we demonstrated that ER stress/HMGA2 axis was involved in inducing ASCT2 and ASNS, while inhibiting GLS1. Additionally, the chromatin immunoprecipitation assay using an HMGA2 antibody revealed the direct binding of the HMGA2 to the promoter sequences of the ASCT2, ASNS, and GLS1 genes. Finally, dual luciferase reporter assay determined that HMGA2 increased the transcription of ASCT2 and ASNS while inhibiting the transcription of GLS1. Overall, we found that ER stress-induced HMGA2 controls glutamine metabolism by transcriptional regulation of ASCT2, ASNS and GLS1 to accelerate cell growth and migration during exposure to Cd at low concentrations. This study innovatively revealed the mechanism of Cd-induced cell growth which offers a fresh perspective on preventing Cd toxicity through glutamine metabolism.
Asunto(s)
Sistema de Transporte de Aminoácidos ASC , Movimiento Celular , Glutamina , Proteína HMGA2 , Animales , Humanos , Masculino , Ratones , Células A549 , Sistema de Transporte de Aminoácidos ASC/metabolismo , Sistema de Transporte de Aminoácidos ASC/genética , Cadmio/toxicidad , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Estrés del Retículo Endoplásmico/efectos de los fármacos , Glutaminasa/metabolismo , Glutaminasa/genética , Glutamina/metabolismo , Proteína HMGA2/metabolismo , Proteína HMGA2/genética , Ratones Endogámicos BALB CRESUMEN
Mitochondrial Pyruvate Carrier 1 (MPC1) is localized on mitochondrial outer membrane to mediate the transport of pyruvate from cytosol to mitochondria. It is also well known to act as a tumor suppressor. Hexavalent chromium (Cr (VI)) contamination poses a global challenge due to its high toxicity and carcinogenesis. This research was intended to probe the potential mechanism of MPC1 in the effect of Cr (VI)-induced carcinogenesis. First, Cr (VI)-treatments decreased the expression of MPC1 in vitro and in vivo. Overexpression of MPC1 inhibited Cr (VI)-induced glycolysis and migration in A549 cells. Then, high mobility group A2 (HMGA2) protein strongly suppressed the transcription of MPC1 by binding to its promoter, and HMGA2/MPC1 axis played an important role in oxidative phosphorylation (OXPHOS), glycolysis and cell migration. Furthermore, endoplasmic reticulum (ER) stress made a great effect on the interaction between HMGA2 and MPC1. Finally, the mammalian target of the rapamycin (mTOR) was determined to mediate MPC1-regulated OXPHOS, aerobic glycolysis and cell migration. Collectively, our data revealed a novel HMGA2/MPC-1/mTOR signaling pathway to promote cell growth via facilitating the metabolism reprogramming from OXPHOS to aerobic glycolysis, which might be a potential therapy for cancers.