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AIM: To investigate the effect of the gp130/STAT3-endoplasmic reticulum (ER) stress axis on hepatocyte necroptosis during acute liver injury. METHODS: ER stress and liver injury in LO2 cells were induced with thapsigargin, and in BALB/c mice with tunicamycin and carbon tetrachloride (CCl4). Glycoprotein 130 (gp130) expression, the degrees of ER stress, and hepatocyte necroptosis were assessed. RESULTS: ER stress significantly upregulated gp130 expression in LO2 cells and mouse livers. The silencing of activating transcription factor 6 (ATF6), but not of ATF4, increased hepatocyte necroptosis and mitigated gp130 expression in LO2 cells and mice. Gp130 silencing reduced the phosphorylation of CCl4-induced signal transducer and activator of transcription 3 (STAT3), and aggravated ER stress, necroptosis, and liver injury in mice. CONCLUSION: ATF6/gp130/STAT3 signaling attenuates necroptosis in hepatocytes through the negative regulation of ER stress during liver injury. Hepatocyte ATF6/gp130/STAT3 signaling may be used as a therapeutic target in acute liver injury.
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Necroptosis , Factor de Transcripción STAT3 , Animales , Ratones , Receptor gp130 de Citocinas/genética , Hepatocitos , Estrés del Retículo Endoplásmico , Glicoproteínas , Ratones Endogámicos BALB C , HígadoRESUMEN
A coumarin-based probe, FP2, was designed for the differential detection of fluoride anions and thiols, i.e., the corresponding nucleophilic substitution products from fluorine-containing G agents and sulfur-containing V agents, thus having the potential to discriminate between these two nerve agents. FP2 with two functional reaction groups, α, ß-unsaturated ketone and silyl groups, can react selectively with fluoride anions and thiols at the µM level respectively. Intriguingly, in the THF solution, FP2 reacts with the fluoride anion but not with the thiol, whereas in the EtOH/HEPES solution, FP2 reacts with the thiol but not with the fluoride anion. As a result, FP2 can produce different fluorophores in the two detection solutions, thus displaying significant fluorescence changes. In addition, the FP2 detection system can show a significant color change from colorless to yellow within seconds when detecting fluoride anions in THF detection solutions, and from yellow to light blue when detecting thiols in EtOH/HEPES solutions, which will facilitate visual detection by emergency responders at the scene of an incident involving a nerve agent.
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Colorantes Fluorescentes/química , Fluoruros/química , Agentes Nerviosos/química , Compuestos de Sulfhidrilo/química , Azufre/química , Concentración de Iones de HidrógenoRESUMEN
When properly employed, targeted therapies are effective cancer treatments. However, the development of such therapies requires the identification of targetable drivers of cancer development and metastasis. The expression and nuclear localization of the transcriptional coactivators Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ) are increased in many human cancers, and experimental evidence indicates that aberrant YAP or TAZ activation drives tumor formation and metastasis. Although these findings make YAP and TAZ appealing therapeutic targets, both have important functions in adult tissues, so directly targeting them could cause adverse effects. The identification of pathways active in cancer cells and required for YAP/TAZ activity could provide a way to inhibit YAP and TAZ. Here, we show that SRC proto-oncogene, nonreceptor tyrosine kinase (SRC) is an important driver of YAP/TAZ activity in human breast cancer and melanoma cells. SRC activation increased YAP/TAZ activity and the expression of YAP/TAZ-regulated genes. In contrast, SRC inhibition or knockdown repressed both YAP/TAZ activity and the expression of YAP/TAZ-regulated genes. We also show that SRC increases the activity of YAP and TAZ by repressing large tumor suppressor homolog (LATS), and we identify the GTPase-activating protein GIT ArfGAP 1 (GIT1) as an SRC effector that regulates both YAP and TAZ. Importantly, we demonstrate that SRC-mediated YAP/TAZ activity promotes tumor growth and enhances metastasis and that SRC-dependent tumor progression depends, at least in part, on YAP and TAZ. Our findings suggest that therapies targeting SRC could help manage some YAP/TAZ-dependent cancers.
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Proteínas Adaptadoras Transductoras de Señales/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Neoplasias Experimentales/metabolismo , Fosfoproteínas/metabolismo , Familia-src Quinasas/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Animales , Proteínas Activadoras de GTPasa/genética , Proteínas Activadoras de GTPasa/metabolismo , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Ratones , Ratones Endogámicos NOD , Ratones SCID , Metástasis de la Neoplasia , Neoplasias Experimentales/genética , Neoplasias Experimentales/patología , Fosfoproteínas/genética , Proto-Oncogenes Mas , Transactivadores , Factores de Transcripción , Proteínas Coactivadoras Transcripcionales con Motivo de Unión a PDZ , Proteínas Señalizadoras YAP , Familia-src Quinasas/genéticaRESUMEN
The transcriptional coactivator Yes-associated protein (YAP) is a major regulator of organ size and proliferation in vertebrates. As such, YAP can act as an oncogene in several tissue types if its activity is increased aberrantly. Although no activating mutations in the yap1 gene have been identified in human cancer, yap1 is located on the 11q22 amplicon, which is amplified in several human tumors. In addition, mutations or epigenetic silencing of members of the Hippo pathway, which represses YAP function, have been identified in human cancers. Here we demonstrate that, in addition to increasing tumor growth, increased YAP activity is potently prometastatic in breast cancer and melanoma cells. Using a Luminex-based approach to multiplex in vivo assays, we determined that the domain of YAP that interacts with the TEAD/TEF family of transcription factors but not the WW domains or PDZ-binding motif, is essential for YAP-mediated tumor growth and metastasis. We further demonstrate that, through its TEAD-interaction domain, YAP enhances multiple processes known to be important for tumor progression and metastasis, including cellular proliferation, transformation, migration, and invasion. Finally, we found that the metastatic potential of breast cancer and melanoma cells is strongly correlated with increased TEAD transcriptional activity. Together, our results suggest that increased YAP/TEAD activity plays a causal role in cancer progression and metastasis.
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Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas de Unión al ADN/metabolismo , Neoplasias Mamarias Animales/metabolismo , Melanoma/metabolismo , Metástasis de la Neoplasia/genética , Fosfoproteínas/metabolismo , Transducción de Señal/genética , Factores de Transcripción/metabolismo , Animales , Western Blotting , Proteínas de Ciclo Celular , Línea Celular Tumoral , Clonación Molecular , Femenino , Citometría de Flujo , Humanos , Luciferasas , Ratones , Mutagénesis Sitio-Dirigida , Reacción en Cadena de la Polimerasa , Estructura Terciaria de Proteína , Retroviridae , Factores de Transcripción de Dominio TEA , Transducción Genética , Proteínas Señalizadoras YAPRESUMEN
With the development of the electric vehicle industry, the number of power batteries has increased dramatically. Establishing a recycling EOL (end-of-life) battery network for secondary use is an effective way to solve resource shortage and environmental pollution. However, existing networks are challenging due to the high uncertainty of EOL batteries, e.g., quantity and quality, resulting in a low recycling rate of the recovery network. To fill this gap, this paper proposes a stochastic programming approach for recovery network design under uncertain conditions of EOL batteries. Firstly, a multi-objective model for battery recovery network is established, considering carbon emissions and economic benefits. Secondly, a stochastic programming approach is proposed to clarify the model. Subsequently, the genetic algorithm is employed to solve the proposed model. Finally, a recovery network case of Region T is given to verify the credibility and superiority of the proposed method. The results demonstrate that the proposed model reduces carbon emissions by 20 metric tons and increases overall economic benefits by 10 million yuan in Region T compared to the deterministic model. Furthermore, the two portions affecting the optimization results are also discussed to provide a reference for reducing carbon emissions and improving economic efficiency in recycling networks.
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BACKGROUND: Uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) plays a crucial role in metabolizing and detoxifying endogenous and exogenous substances. However, its contribution to the progression of liver damage remains unclear. AIM: To determine the role and mechanism of UGT1A1 in liver damage progression. METHODS: We investigated the relationship between UGT1A1 expression and liver injury through clinical research. Additionally, the impact and mechanism of UGT1A1 on the progression of liver injury was analyzed through a mouse model study. RESULTS: Patients with UGT1A1 gene mutations showed varying degrees of liver damage, while patients with acute-on-chronic liver failure (ACLF) exhibited relatively reduced levels of UGT1A1 protein in the liver as compared to patients with chronic hepatitis. This suggests that low UGT1A1 levels may be associated with the progression of liver damage. In mouse models of liver injury induced by carbon tetrachloride (CCl4) and concanavalin A (ConA), the hepatic levels of UGT1A1 protein were found to be increased. In mice with lipopolysaccharide or liver steatosis-mediated liver-injury progression, the hepatic protein levels of UGT1A1 were decreased, which is consistent with the observations in patients with ACLF. UGT1A1 knockout exacerbated CCl4- and ConA-induced liver injury, hepatocyte apoptosis and necroptosis in mice, intensified hepatocyte endoplasmic reticulum (ER) stress and oxidative stress, and disrupted lipid metabolism. CONCLUSION: UGT1A1 is upregulated as a compensatory response during liver injury, and interference with this upregulation process may worsen liver injury. UGT1A1 reduces ER stress, oxidative stress, and lipid metabolism disorder, thereby mitigating hepatocyte apoptosis and necroptosis.
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Glucuronosiltransferasa , Hígado , Animales , Humanos , Ratones , Modelos Animales de Enfermedad , Glucuronosiltransferasa/genética , Glucuronosiltransferasa/metabolismo , Hígado/metabolismoRESUMEN
VISTA, an inhibitory myeloid-T-cell checkpoint, holds promise as a target for cancer immunotherapy. However, its effective targeting has been impeded by issues such as rapid clearance and cytokine release syndrome observed with previous VISTA antibodies. Here we demonstrate that SNS-101, a newly developed pH-selective VISTA antibody, addresses these challenges. Structural and biochemical analyses confirmed the pH-selectivity and unique epitope targeted by SNS-101. These properties confer favorable pharmacokinetic and safety profiles on SNS-101. In syngeneic tumor models utilizing human VISTA knock-in mice, SNS-101 shows in vivo efficacy when combined with a PD-1 inhibitor, modulates cytokine and chemokine signaling, and alters the tumor microenvironment. In summary, SNS-101, currently in Phase I clinical trials, emerges as a promising therapeutic biologic for a wide range of patients whose cancer is refractory to current immunotherapy regimens.
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Neoplasias , Receptor de Muerte Celular Programada 1 , Humanos , Ratones , Animales , Antígenos B7 , Anticuerpos , Neoplasias/tratamiento farmacológico , Inmunoterapia , Concentración de Iones de Hidrógeno , Microambiente TumoralRESUMEN
Living cells continually generate reactive oxygen species (ROS) through the respiratory chain during energetic metabolism. ROS at low or moderate concentration can play important physiological roles. However, an excessive amount of ROS under oxidative stress would be extremely deleterious. The central nervous system (CNS) is particularly vulnerable to oxidative stress due to its high oxygen consumption, weakly antioxidative systems and the terminal-differentiation characteristic of neurons. Thus, oxidative stress elicits various neurodegenerative diseases. In addition, chemotherapy could result in severe side effects on the CNS and peripheral nervous system (PNS) of cancer patients, and a growing body of evidence demonstrates the involvement of ROS in drug-induced neurotoxicities as well. Therefore, development of antioxidants as neuroprotective drugs is a potentially beneficial strategy for clinical therapy. In this review, we summarize the source, balance maintenance and physiologic functions of ROS, oxidative stress and its toxic mechanisms underlying a number of neurodegenerative diseases, and the possible involvement of ROS in chemotherapy-induced toxicity to the CNS and PNS. We ultimately assess the value for antioxidants as neuroprotective drugs and provide our comments on the unmet needs.
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Enfermedades Neurodegenerativas/metabolismo , Estrés Oxidativo , Animales , Antioxidantes/metabolismo , Antioxidantes/uso terapéutico , Apoptosis , Estrés del Retículo Endoplásmico , Humanos , Enfermedades Neurodegenerativas/tratamiento farmacológico , Enfermedades Neurodegenerativas/patología , Oxidorreductasas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Respuesta de Proteína DesplegadaRESUMEN
Using the promoter for cardiac myosin light chain 2 (cmlc2) gene, an expression vector pTol2-cmlc2-IRES- EGFP for making heart-specific expression of exogenous gene in transgenic zebrafish was generated previously. Here, we reported the construction of a transgenic zebrafish line which stably expresses EGFP using this vector, and the effects of EGFP on the heart development and cardiac function of this transgenic zebrafish line were preliminarily analyzed. The results showed that the green fluorescence signal of cmlc2:EGFP line under fluorescence microscopy specifically expressed in heart and faithfully recapitulated both the spatial and temporal expression patterns of endogenous cmlc2 gene revealed by in situ hybridization in the early developmental stages. The cardiac morphology and development of this transgenic zebrafish line remained to be normal. Furthermore, the heart morphology and physiological function of this transgenic line have been analyzed using M-mode analysis. The results showed that there was no significant difference between the cmlc2:EGFP and the wild type lines with respect to heart period, heart rate, diastolic surface area and systolic surface area, and fractional area change. No tachyarrhythmia was observed in the embryos from either line. Thus, the excessive expression of EGFP in this transgenic line seemed to exert no detrimental effects on the function and development of zebrafish hearts during early stages. Our study laid a foundation for the construction of exogenous gene transgenic line using pTol2-cmlc2-IRES-EGFP vector to study the function of genes that expressed in heart.
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Proteínas Fluorescentes Verdes/genética , Miocardio/metabolismo , Pez Cebra/genética , Animales , Animales Modificados Genéticamente , Regulación de la Expresión Génica , Vectores Genéticos/genética , Corazón/fisiología , Cadenas Ligeras de Miosina/genética , Especificidad de Órganos , Pez Cebra/fisiología , Proteínas de Pez Cebra/genéticaRESUMEN
Excessive manganese (Mn) exposure produces neurotoxicity with mitochondrial damage. Mitophagy is a protective mechanism to eliminate damaged mitochondria to protect cells. The aim of this study was to determine the dose-response of Mn-induced mitochondria damage, the expression of mitophagy-mediated protein PINK1/Parkin and mitophagy in dopamine-producing SK-N-SH cells. Cells were exposed to 0, 300, 900, and 1500 µM Mn2+ for 24 h, and ROS production, mitochondrial damage and mitophagy were examined. The levels of dopamine were detected by ELISA and neurotoxicity and mitophagy-related proteins (α-synuclein, PINK1, Parkin, Optineurin, and LC3II/I) were detected by western blot. Mn increased intracellular ROS and apoptosis and decreased mitochondrial membrane potential in a concentration-dependent manner. However, at the low dose of 300 µM Mn, autophagosome was increased 11-fold, but at the high dose of 1500 µM, autophagosome was attenuated to 4-fold, together with decreased mitophagy-mediated protein PINK1/Parkin and LC3II/I ratio and increased Optineurin expression, resulting in increased α-synuclein accumulation and decreased dopamine production. Thus, Mn-induced mitophagy exhibited a novel biphasic regulation: at the low dose, mitophagy is activated to eliminate damaged mitochondria, however, at the high dose, cells gradually loss the adaptive machinery, the PINK1/Parkin-mediated mitophagy weakened, resulting in neurotoxicity.
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BACKGROUND: Coronavirus disease 2019 (COVID-19) is one of the current global public health threats and vaccination is the most effective tool to reduce the spread and decrease the severity of COVID-19. Diabetes is one of the important chronic diseases threatening human health and is a common comorbidity of COVID-19. What is the impact of diabetes on the immunization effect of COVID-19 vaccination? Conversely, does vaccination against COVID-19 exacerbate the severity of pre-existing diseases in patients with diabetes? There are limited and conflicting data on the interrelationship between diabetes and COVID-19 vaccination. AIM: To explore the clinical factors and possible mechanisms underlying the interaction between COVID-19 vaccination and diabetes. METHODS: We conducted a comprehensive search of PubMed, MEDLINE, EMBASE, and Reference Citation Analysis (https://www.referencecitationanalysis.com) online databases, and medRxiv and bioRxiv gray literature using the keywords "SARS-CoV-2", "COVID-19", "vaccine", "vaccination", "antibody", and "diabetes" individually or in combination, with a cut-off date of December 2, 2022. We followed inclusion and exclusion criteria and after excluding duplicate publications, studies with quantifiable evidence were included in the full-text review, plus three manually searched publications, resulting in 54 studies being included in this review. RESULTS: A total of 54 studies were included, from 17 countries. There were no randomized controlled studies. The largest sample size was 350963. The youngest of the included samples was 5 years old and the oldest was 98 years old. The included population included the general population and also some special populations with pediatric diabetes, hemodialysis, solid organ transplantation, and autoimmune diseases. The earliest study began in November 2020. Thirty studies discussed the effect of diabetes on vaccination, with the majority indicating that diabetes reduces the response to COVID-19 vaccination. The other 24 studies were on the effect of vaccination on diabetes, which included 18 case reports/series. Most of the studies concluded that COVID-19 vaccination had a risk of causing elevated blood glucose. A total of 12 of the 54 included studies indicated a "no effect" relationship between diabetes and vaccination. CONCLUSION: There is a complex relationship between vaccination and diabetes with a bidirectional effect. Vaccination may contribute to the risk of worsening blood glucose in diabetic patients and diabetic patients may have a lower antibody response after vaccination than the general population.
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The catastrophic coronavirus disease 2019 (COVID-19) pandemic has raised many health questions, and whether breast milk from SARS-CoV-2 infected mothers may be a vector for SARS-CoV-2 transmission has become a hot topic of concern worldwide. Currently, there are extremely limited and conflicting data on the risk of infection in infants through breastfeeding. For this reason, we investigated almost all current clinical studies and systematically analyzed the presence of SARS-CoV-2 and antibodies in the breast milk of mothers infected with SARS-CoV-2, their effects on newborns, and the mechanisms involved. A total of 82 studies were included in this review, of which 66 examined the presence of SARS-CoV-2 in breast milk samples from mothers diagnosed with COVID-19, 29 reported results of antibody detection of SARS-CoV-2 in breast milk, and 13 reported both nucleic acid and antibody test results. Seventeen studies indicated the presence of detectable SARS-CoV-2 nucleic acid in breast milk samples, and only two studies monitored viral activity, both of which reported that infectious viruses could not be cultured from RNA-positive breast milk samples. All 29 studies indicated the presence of at least one of the three antibodies, IgA, IgG and IgM, in breast milk. Five studies indicated the presence of at least one antibody in the serum of breastfed newborns. No COVID-19-related deaths were reported in all 1,346 newborns. Our study suggests that direct breastfeeding does not pose an additional risk of infection to newborns and that breast milk is a beneficial source of anti-SARS-CoV-2 antibodies that provide passive immune protection to infants. In addition, direct breastfeeding would provide maternal benefits. Our review supports the recommendation to encourage direct breastfeeding under appropriate infection control guidelines. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/#myprospero, identifier: 458043.
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NADH-cytochrome b5 oxidoreductase (Ncb5or) is an endoplasmic reticulum (ER)-associated redox enzyme involved in fatty acid metabolism, and phenotypic abnormalities of Ncb5or(-/-) mice include diabetes and lipoatrophy. These mice are lean and insulin-sensitive but become hyperglycemic at age 7 weeks as a result of ß-cell dysfunction and loss. Here we examine early cellular and molecular events associated with manifestations of ß-cell defects in Ncb5or(-/-) mice. We observe lower islet ß-cell content in pancreata at age 4 weeks and prominent ER distention in ß-cells by age 5 weeks. Ultrastructural changes progress rapidly in severity from age 5 to 6 weeks, and their frequency rises from 10% of ß-cells at 5 weeks to 33% at 6 weeks. These changes correlate temporally with the onset of diabetes. ER stress responses and lipid load in Ncb5or(-/-) ß-cells were assessed with isolated islets from mice at age 5 weeks. Expression levels of the stress marker protein Grp78/BiP and of phosphorylated eIF2α protein were found to be reduced, although their transcript levels did not decline. This pattern stands in contrast to the canonical unfolded protein response. Ncb5or(-/-) ß-cells also accumulated higher intracellular levels of palmitate and other free fatty acids and exhibited greater reactive oxygen species production than wild-type cells. An alloxan-susceptible genetic background was found to confer accelerated onset of diabetes in Ncb5or(-/-) mice. These findings provide the first direct evidence that manifestations of diabetes in lean Ncb5or(-/-) mice involve saturated free fatty acid overload of ß-cells and ER and oxidative stress responses.
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Citocromo-B(5) Reductasa/fisiología , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/patología , Retículo Endoplásmico/patología , Células Secretoras de Insulina/patología , Estrés Oxidativo , Aloxano , Animales , Western Blotting , Diabetes Mellitus Experimental/metabolismo , Retículo Endoplásmico/metabolismo , Chaperón BiP del Retículo Endoplásmico , Ácidos Grasos Insaturados/metabolismo , Femenino , Técnica del Anticuerpo Fluorescente , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Células Secretoras de Insulina/metabolismo , Islotes Pancreáticos , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Mitocondrias/metabolismo , Mitocondrias/patología , Oxidación-Reducción , Palmitatos/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Respuesta de Proteína DesplegadaRESUMEN
BACKGROUND: There is growing evidence that patients with coronavirus disease 2019 (COVID-19) frequently present with liver impairment. Hepatitis B virus (HBV) remains a major public health threat in current society. Both severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and HBV can cause liver damage, and current findings on whether HBV infection increases disease severity in COVID-19 patients are inconsistent, and whether SARS-CoV-2 infection accelerates hepatitis B progression or leads to a worse prognosis in hepatitis B patients has not been adequately elucidated. AIM: To explore the complex relationship between COVID-19 and hepatitis B in order to inform the research and management of patients co-infected with SARS-CoV-2 and HBV. METHODS: An experienced information specialist searched the literature in the following online databases: PubMed, China National Knowledge Infrastructure, Google Scholar, Scopus, Wiley, Web of Science, Cochrane, and ScienceDirect. The literature published from December 2019 to September 1, 2022 was included in the search. We also searched medRxiv and bioRxiv for gray literature and manually scanned references of included articles. Articles reporting studies conducted in humans discussing hepatitis B and COVID-19 were included. We excluded duplicate publications. News reports, reports, and other gray literature were included if they contained quantifiable evidence (case reports, findings, and qualitative analysis). Some topics that included HBV or COVID-19 samples but did not have quantitative evidence were excluded from the review. RESULTS: A total of 57 studies were eligible and included in this review. They were from 11 countries, of which 33 (57.9%) were from China. Forty-two of the 57 studies reported abnormalities in liver enzymes, three mainly reported abnormalities in blood parameters, four indicated no significant liver function alterations, and another eight studies did not provide data on changes in liver function. Fifty-seven studies were retrospective and the total number of co-infections was 1932, the largest sample size was 7723, and the largest number of co-infections was 353. Most of the studies suggested an interaction between hepatitis B and COVID-19, while 12 studies clearly indicated no interaction between hepatitis B and COVID-19. Six of the 57 studies clearly reported HBV activation. Six studies were related to liver transplant patients. CONCLUSION: There is some association between COVID-19 and hepatitis B. Future high-quality randomized trials are needed to further elucidate the interaction between COVID-19 and hepatitis B.
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COVID-19 , Coinfección , Hepatitis B , Humanos , SARS-CoV-2 , Estudios Retrospectivos , Hepatitis B/complicaciones , Hepatitis B/diagnóstico , Hepatitis B/epidemiología , Virus de la Hepatitis BRESUMEN
BACKGROUND: Endoplasmic reticulum (ER) stress contributes to the pathogenesis of chronic liver diseases, but how hepatocytes respond to ER stress has not been clarified. Alpha-fetoprotein (AFP) is secreted by hepatoma cells and elevated levels of serum AFP are associated with development of liver malignancies. AIM: To investigate whether and how AFP could regulate ER stress and hepatocyte injury. METHODS: The distribution of AFP and the degrees of ER stress in liver tissues and liver injury were characterized by histology, immunohistochemistry, and Western blot in biopsied human liver specimens, two mouse models of liver injury and a cellular model. The levels of AFP in sera and the supernatants of cultured cells were quantified by chemiluminescence. RESULTS: High levels of intracellular AFP were detected in liver tissues, particularly in the necrotic areas, from patients with chronic liver diseases and mice after carbon tetrachloride (CCl4) administration or induction of ER stress, but not from the controls. The induced intracellular AFP was accompanied by elevated activating transcription factor-6 (ATF6) expression and protein kinase R-like ER kinase (PERK) phosphorylation in mouse livers. ER stress induced AFP expression in LO2 cells and decreased their viability. ATF6, but not PERK, silencing mitigated the ER-stress-induced AFP expression in LO2 cells. Conversely, AFP silencing deteriorated the ER stress-mediated LO2 cell injury and CCl4 administration-induced liver damages by increasing levels of cleaved caspase-3, the C/enhancer binding protein homologous protein expression, mixed lineage kinase domain-like pseudokinase and PERK phosphorylation, but decreasing ATF6 expression. CONCLUSION: ER stress upregulated intra-hepatocyte AFP expression by activating ATF6 during the process of liver injury and intracellular AFP attenuated hepatocyte apoptosis and necroptosis by alleviating ER stress.
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Estrés del Retículo Endoplásmico , Hepatopatías , Animales , Apoptosis , Hepatocitos/patología , Humanos , Hepatopatías/patología , Ratones , Necroptosis , alfa-Fetoproteínas/metabolismoRESUMEN
Hepatocyte nuclear factor alpha (HNF1α), endoplasmic reticulum (ER) stress, and hepatocyte apoptosis contribute to severe acute exacerbation (SAE) of liver injury. Here, we explore HNF1α-ER stress-hepatocyte apoptosis interaction in liver injury. LO2, HepG2 and SK-Hep1 cells were treated with thapsigargin (TG) or tunicamycin (TM) to induce ER stress. Carbon tetrachloride (CCl4) was used to induce acute liver injury in mice. Low-dose lipopolysaccharide (LPS) exacerbated liver injury in CCl4-induced mice. Significant apoptosis, HNF1α upregulation, and nuclear factor kappa B (NF-κB) activation were observed in human-derived hepatocytes during ER stress. Knockdown of Rela, NF-κB p65, inhibited the HNF1α upregulation. Following CCl4 treatment ER stress, apoptosis, HNF1α expression and RelA phosphorylation were significantly increased in mice. HNF1α knockdown reduced activating transcription factor 4 (ATF4) expression, and aggravated ER stress as well as hepatocyte apoptosis in vivo and in vitro. The double fluorescent reporter gene assay confirmed that HNF1α regulated the transcription of ATF4 promoter. LPS aggravated CCl4-induced liver injury and reduced HNF1α, and ATF4 expression. Therefore, in combination, HNF1α and ER stress could be mutually regulated forming a feedback loop, which helps in protecting the injured liver by down-regulating hepatocyte apoptosis. Low-dose LPS aggravates hepatocyte apoptosis and promotes the SAE of liver injury by interfering with the feedback regulation of HNF1α and ER stress in acute liver injury.
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Estrés del Retículo Endoplásmico , Factor Nuclear 1-alfa del Hepatocito , Factor de Transcripción Activador 4/metabolismo , Animales , Apoptosis , Estrés del Retículo Endoplásmico/fisiología , Retroalimentación , Factor Nuclear 1-alfa del Hepatocito/metabolismo , Hepatocitos/metabolismo , Humanos , Lipopolisacáridos/metabolismo , Hígado/metabolismo , Ratones , FN-kappa B/metabolismoRESUMEN
BACKGROUND: Activating transcription factor 6 (ATF6) and receptor-interacting protein 3 (RIP3) are important signaling proteins in endoplasmic reticulum (ER) stress and necroptosis, respectively. However, their regulatory relationship and clinical significance are unknown. We investigate the impact of ATF6 on RIP3 expression, and its role in hepatocyte necroptosis in an acute liver injury model. METHODS: In vivo and in vitro experiments were carried out. LO2 cells were treated with thapsigargin (TG). In vivo, male BALB/c mice were treated with carbon tetrachloride (CCl4, 1 mL/kg) or tunicamycin (TM, 2 mg/kg). Then, the impact of ATF6 or RIP3 silencing on liver injury, hepatocyte necroptosis, and ER stress-related protein expression was examined. RESULTS: TG induced ER stress and necroptosis and ATF6 and RIP3 expression in LO2 cells. The knockdown of ATF6 significantly decreased RIP3 expression (p < 0.05) and increased ER stress and necroptosis. The downregulation of RIP3 significantly reduced necroptosis and ER stress (p < 0.05). Similar results were observed in CCl4 or the TM-induced mouse model. The knockdown of ATF6 significantly decreased CCl4-induced RIP3 expression and increased liver injury, necroptosis, and ER stress in mice livers (p < 0.05). In contrast, the downregulation of RIP3 significantly reduced liver injury, hepatocyte necroptosis, and ER stress. CONCLUSIONS: Hepatocyte ATF6 has multiple roles in acute liver injury. It reduces hepatocyte necroptosis via negative feedback regulation of ER stress. In addition, ATF6 can upregulate the expression of RIP3, which is not helpful to the recovery process. However, downregulating RIP3 reduces hepatocyte necroptosis by promoting the alleviation of ER stress. The findings suggest that RIP3 could be a plausible target for the treatment of liver injury.
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Factor de Transcripción Activador 6/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Factor de Transcripción Activador 6/genética , Animales , Apoptosis , Enfermedad Hepática Inducida por Sustancias y Drogas/genética , China , Modelos Animales de Enfermedad , Estrés del Retículo Endoplásmico/genética , Hepatocitos/metabolismo , Hígado/metabolismo , Hígado/patología , Masculino , Ratones , Ratones Endogámicos BALB C , Modelos Animales , Necroptosis/genética , Necroptosis/fisiología , Proteína Serina-Treonina Quinasas de Interacción con Receptores/genética , Transducción de Señal/genéticaRESUMEN
NCB5OR is a novel flavoheme reductase with a cytochrome b5-like domain at the N-terminus and a cytochrome b5 reductase-like domain at the C terminus. Ncb5or knock-out mice develop insulin deficient diabetes and loss of white adipose tissue. Ncb5or(-/-) mice have impairment of Delta9 fatty acid desaturation with elevated ratios of palmitate to palmitoleate and stearate to oleate. In this study we assess the role of the endoplasmic reticulum (ER) stress response in mediating lipotoxicity in Ncb5or(-/-) mice. The ER stress response was assessed by induction of BiP, ATF3, ATF6, XBP-1, and C/EBP homologous protein (CHOP). Exposure to palmitate, but not oleate or mixtures of oleate and palmitate induced these markers of ER stress to a much greater extent in Ncb5or(-/-) hepatocytes than in wild-type cells. In contrast, Ncb5or(-/-) and Ncb5or(+/+) hepatocytes were equally sensitive to ER stress imposed by increasing concentrations of tunicamycin. In order to assess the role of ER stress in vivo, we prepared mice that lack both NCB5OR and CHOP, a proapoptotic transcription factor important in the ER stress response. Onset of hyperglycemia in the Chop(-/-);Ncb5or(-/-) mice was delayed two weeks beyond that observed in Chop(+/+);Ncb5or(-/-) mice. Taken together these results suggest that ER stress plays a critical role in palmitate-induced lipotoxicity both in vitro and in vivo.
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Citocromo-B(5) Reductasa/metabolismo , Retículo Endoplásmico/enzimología , Hepatocitos/enzimología , Palmitatos/metabolismo , Factor de Transcripción CHOP/metabolismo , Animales , Antibacterianos/farmacología , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Biomarcadores/metabolismo , Glucemia/análisis , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Citocromo-B(5) Reductasa/genética , Diabetes Mellitus/genética , Retículo Endoplásmico/efectos de los fármacos , Hepatocitos/efectos de los fármacos , Hepatocitos/ultraestructura , Hiperglucemia/genética , Insulina/metabolismo , Ratones , Ratones Noqueados , Microscopía Electrónica de Transmisión , Ácido Oléico/metabolismo , Ácido Oléico/toxicidad , Palmitatos/toxicidad , Páncreas/efectos de los fármacos , Páncreas/metabolismo , Estrés Fisiológico/genética , Factor de Transcripción CHOP/genética , Tunicamicina/farmacologíaRESUMEN
JC virus (JCV) is a polyomavirus that infects human oligodendrocytes, leading to development of progressive multifocal leukoencephalopathy (PML), an often fatal demyelinating disease occurring in immunocompromised individuals. Currently there are no effective therapies for the treatment of PML that result in clearance of JCV from the brain. Cidofovir (CDV) is an acyclic nucleoside phosphonate that inhibits DNA polymerases and has been used for the treatment of PML. However, CDV demonstrated little efficacy as a treatment for PML and causes substantial side effects to patients. To improve efficacy and reduce the toxicity of CDV, a lipid-ester derivative, CMX001, was generated by Chimerix and is currently in multicenter phase II clinical trials for the prevention or control of cytomegalovirus infection in hematopoietic stem cell transplant recipients and of BK virus in the urine of stem cell or renal allograft recipients. CMX001 caused minimal cytotoxic effects in human fetal brain SVG cells when used at concentrations between 0.01 µM and 0.1 µM. CMX001 resulted in a dose-dependent decrease in the number of JCV-infected cells during initial infection and nearly eliminated JCV-infected cells during an established infection. In addition, CMX001 treatment resulted in a 60% reduction in JCV DNA copy number during initial infection, which suggests that suppression of JCV infection by CMX001 is likely due to inhibition of virus DNA replication. This study demonstrates that CMX001 suppresses JCV infection at concentrations that have limited toxicity to human brain cells, indicating its potential use to limit JCV replication in infected patients.
Asunto(s)
Antivirales/farmacología , Encéfalo/citología , Encéfalo/embriología , Citosina/análogos & derivados , Feto/citología , Virus JC/efectos de los fármacos , Organofosfonatos/farmacología , Replicación Viral/efectos de los fármacos , Antivirales/química , Línea Celular , Citosina/química , Citosina/farmacología , Humanos , Hibridación in Situ , Microscopía de Contraste de Fase , Estructura Molecular , Organofosfonatos/química , Reacción en Cadena de la PolimerasaRESUMEN
Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive malignancy with very limited treatment options. Antibody drug conjugates (ADCs) are promising cytotoxic agents capable of highly selective delivery. Aspartate-ß-hydroxylase (ASPH) is a type II transmembrane protein highly expressed in PDACs (97.1%) but not normal pancreas. We investigated anti-tumor effects of an ADC guided by a human monoclonal antibody (SNS-622) against ASPH in human PDAC cell lines and derived subcutaneous (s.c.) xenograft as well as a patient-derived xenograft (PDX) murine model with spontaneous pulmonary metastasis. The cytotoxic effects exhibited by several candidate payloads linked to SNS-622 antibody targeting ASPH+ PDACs were analyzed. After i.v. administration of SNS-622-emtansine (DM1) ADC, the primary PDAC tumor growth and progression (number and size of pulmonary metastases) were determined. The PDAC cell lines, s.c. and PDX tumors treated with ADC were tested for cell proliferation, cytotoxicity and apoptosis by MTS and immunohistochemistry (IHC) assays. SNS-622-DM1 construct has demonstrated optimal anti-tumor effects in vitro. In the PDX model of human PDAC, SNS-622-DM1 ADC exerted substantially inhibitory effects on tumor growth and pulmonary metastasis through attenuating proliferation and promoting apoptosis.