RESUMEN
Brown adipose tissue (BAT) is the main site of nonshivering thermogenesis which plays an important role in thermogenesis and energy metabolism. However, the regulatory factors that inhibit BAT activity remain largely unknown. Here, cardiotrophin-like cytokine factor 1 (CLCF1) is identified as a negative regulator of thermogenesis in BAT. Adenovirus-mediated overexpression of CLCF1 in BAT greatly impairs the thermogenic capacity of BAT and reduces the metabolic rate. Consistently, BAT-specific ablation of CLCF1 enhances the BAT function and energy expenditure under both thermoneutral and cold conditions. Mechanistically, adenylate cyclase 3 (ADCY3) is identified as a downstream target of CLCF1 to mediate its role in regulating thermogenesis. Furthermore, CLCF1 is identified to negatively regulate the PERK-ATF4 signaling axis to modulate the transcriptional activity of ADCY3, which activates the PKA substrate phosphorylation. Moreover, CLCF1 deletion in BAT protects the mice against diet-induced obesity by promoting BAT activation and further attenuating impaired glucose and lipid metabolism. Therefore, our results reveal the essential role of CLCF1 in regulating BAT thermogenesis and suggest that inhibiting CLCF1 signaling might be a potential therapeutic strategy for improving obesity-related metabolic disorders.
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Tejido Adiposo Pardo , Metabolismo Energético , Animales , Ratones , Adenoviridae , Interleucinas , Obesidad/genética , Termogénesis/genéticaRESUMEN
Parental histone recycling is vital for maintaining chromatin-based epigenetic information during replication, yet its underlying mechanisms remain unclear. Here, we uncover an unexpected role of histone chaperone FACT and its N-terminus of the Spt16 subunit during parental histone recycling and transfer in budding yeast. Depletion of Spt16 and mutations at its middle domain that impair histone binding compromise parental histone recycling on both the leading and lagging strands of DNA replication forks. Intriguingly, deletion of the Spt16-N domain impairs parental histone recycling, with a more pronounced defect observed on the lagging strand. Mechanistically, the Spt16-N domain interacts with the replicative helicase MCM2-7 and facilitates the formation of a ternary complex involving FACT, histone H3/H4 and Mcm2 histone binding domain, critical for the recycling and transfer of parental histones to lagging strands. Lack of the Spt16-N domain weakens the FACT-MCM interaction and reduces parental histone recycling. We propose that the Spt16-N domain acts as a protein-protein interaction module, enabling FACT to function as a shuttle chaperone in collaboration with Mcm2 and potentially other replisome components for efficient local parental histone recycling and inheritance.
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Histonas , Proteínas de Saccharomyces cerevisiae , Factores de Elongación Transcripcional , Cromatina/genética , ADN Helicasas/genética , Chaperonas de Histonas/genética , Chaperonas de Histonas/metabolismo , Histonas/metabolismo , Chaperonas Moleculares/genética , Nucleosomas/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Factores de Elongación Transcripcional/metabolismo , Complejos Multiproteicos/metabolismoRESUMEN
Senescence of vascular smooth muscle cells (VSMCs) is a key contributor to plaque vulnerability in atherosclerosis (AS), which is affected by endoplasmic reticulum (ER) stress and reactive oxygen species (ROS) production. However, the crosstalk between ER stress and ROS production in the pathogenesis of VSMC senescence remains to be elucidated. ER-associated degradation (ERAD) is a complex process that clears unfolded or misfolded proteins to maintain ER homeostasis. HRD1 is the major E3 ligase in mammalian ERAD machineries that catalyzes ubiquitin conjugation to the unfolded or misfolded proteins for degradation. Our results showed that HRD1 protein levels were reduced in human AS plaques and aortic roots from ApoE-/- mice fed with high-fat diet (HFD), along with the increased ER stress response. Exposure to cholesterol in VSMCs activated inflammatory signaling and induced senescence, while reduced HRD1 protein expression. CRISPR Cas9-mediated HRD1 knockout (KO) exacerbated cholesterol- and thapsigargin-induced cell senescence. Inhibiting ER stress with 4-PBA (4-Phenylbutyric acid) partially reversed the ROS production and cell senescence induced by HRD1 deficiency in VSMCs, suggesting that ER stress alone could be sufficient to induce ROS production and senescence in VSMCs. Besides, HRD1 deficiency led to mitochondrial dysfunction, and reducing ROS production from impaired mitochondria partly reversed HRD1 deficiency-induced cell senescence. Finally, we showed that the overexpression of HDR1 reversed cholesterol-induced ER stress, ROS production, and cellular senescence in VSMCs. Our findings indicate that HRD1 protects against senescence by maintaining ER homeostasis and mitochondrial functionality. Thus, targeting HRD1 function may help to mitigate VSMC senescence and prevent vascular aging related diseases. TRIAL REGISTRATION: A real-world study based on the discussion of primary and secondary prevention strategies for coronary heart disease, URL:https://www.clinicaltrials.gov, the trial registration number is [2022]-02-121-01.
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Aterosclerosis , Músculo Liso Vascular , Animales , Humanos , Ratones , Aterosclerosis/metabolismo , Senescencia Celular , Estrés del Retículo Endoplásmico/fisiología , Degradación Asociada con el Retículo Endoplásmico , Mamíferos/metabolismo , Músculo Liso Vascular/metabolismo , Proteínas/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
BACKGROUND: Diabetic retinopathy (DR) is a major cause of blindness and is characterized by dysfunction of the retinal microvasculature. Neutrophil stasis, resulting in retinal inflammation and the occlusion of retinal microvessels, is a key mechanism driving DR. These plugging neutrophils subsequently release neutrophil extracellular traps (NETs), which further disrupts the retinal vasculature. Nevertheless, the primary catalyst for NETs extrusion in the retinal microenvironment under diabetic conditions remains unidentified. In recent studies, cellular communication network factor 1 (CCN1) has emerged as a central molecule modulating inflammation in pathological settings. Additionally, our previous research has shed light on the pathogenic role of CCN1 in maintaining endothelial integrity. However, the precise role of CCN1 in microvascular occlusion and its potential interaction with neutrophils in diabetic retinopathy have not yet been investigated. METHODS: We first examined the circulating level of CCN1 and NETs in our study cohort and analyzed related clinical parameters. To further evaluate the effects of CCN1 in vivo, we used recombinant CCN1 protein and CCN1 overexpression for gain-of-function, and CCN1 knockdown for loss-of-function by intravitreal injection in diabetic mice. The underlying mechanisms were further validated on human and mouse primary neutrophils and dHL60 cells. RESULTS: We detected increases in CCN1 and neutrophil elastase in the plasma of DR patients and the retinas of diabetic mice. CCN1 gain-of-function in the retina resulted in neutrophil stasis, NETs extrusion, capillary degeneration, and retinal leakage. Pre-treatment with DNase I to reduce NETs effectively eliminated CCN1-induced retinal leakage. Notably, both CCN1 knockdown and DNase I treatment rescued the retinal leakage in the context of diabetes. In vitro, CCN1 promoted adherence, migration, and NETs extrusion of neutrophils. CONCLUSION: In this study, we uncover that CCN1 contributed to retinal inflammation, vessel occlusion and leakage by recruiting neutrophils and triggering NETs extrusion under diabetic conditions. Notably, manipulating CCN1 was able to hold therapeutic promise for the treatment of diabetic retinopathy.
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Proteína 61 Rica en Cisteína , Retinopatía Diabética , Trampas Extracelulares , Neutrófilos , Animales , Femenino , Humanos , Masculino , Ratones , Proteína 61 Rica en Cisteína/metabolismo , Proteína 61 Rica en Cisteína/genética , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/complicaciones , Retinopatía Diabética/patología , Retinopatía Diabética/metabolismo , Retinopatía Diabética/genética , Trampas Extracelulares/genética , Trampas Extracelulares/metabolismo , Ratones Endogámicos C57BL , Neutrófilos/metabolismo , Retina/patología , Retina/metabolismoRESUMEN
The selective oxidation of toluene to yield value-added oxygenates, such as benzyl alcohol, benzaldehyde, and benzoic acid, via dioxygen presents a chlorine-free approach under benign conditions. Metal-free catalytic processes are preferred to avoid metal ion contamination. In this study, we employed N-hydroxyphthalimide (NHPI) as a catalyst for the aerobic oxidation of toluene to its oxygenated derivatives. The choice of solvent exerted a significant impact on the catalytic activity and selectivity of the catalyst NHPI at reaction temperatures exceeding 70 °C. Notably, hexafluoroisopropanol substantially enhanced the selective production of benzaldehyde. Furthermore, we identified didecyl dimethyl ammonium bromide, featuring two symmetrical long hydrophobic chains, as a potent enhancer of NHPI for the solvent-free aerobic oxidation of toluene. This effect is ascribed to its unique symmetrical structure, extraction capabilities, and resistance to thermal and acid/base conditions. Based on the product distribution and control experiments, we proposed a plausible reaction mechanism. These findings may inform the industrial synthesis of oxygenated derivatives from toluene.
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Phenotypic change of vascular smooth muscle cells (VSMCs) is the main contributor of vascular pathological remodeling in atherosclerosis. The endoplasmic reticulum (ER) is critical for maintaining VSMC function through elimination of misfolded proteins that impair VSMC cellular function. ER-associated degradation (ERAD) is an ER-mediated process that controls protein quality by clearing misfolded proteins. One of the critical regulators of ERAD is HRD1, which also plays a vital role in lipid metabolism. However, the function of HRD1 in VSMCs of atherosclerotic vessels remains poorly understood. The level of HRD1 expression was analyzed in aortic tissues of mice fed with a high-fat diet (HFD). The H&E and EVG (VERHOEFF'S VAN GIESON) staining were used to demonstrate pathological vascular changes. IF (immunofluorescence) and WB (western blot) were used to explore the signaling pathways in vivo and in vitro. The wound closure and transwell assays were also used to test the migration rate of VSMCs. CRISPR gene editing and transcriptomic analysis were applied in vitro to explore the cellular mechanism. Our data showed significant reduction of HRD1 in aortic tissues of mice under HFD feeding. VSMC phenotypic change and HRD1 downregulation were detected by cholesterol supplement. Transcriptomic and further analysis of HRD1-KO VSMCs showed that HRD1 deficiency induced the expression of genes related to ER stress response, proliferation and migration, but reduced the contractile-related genes in VSMCs. HRD1 deficiency also exacerbated the proliferation, migration and ROS production of VSMCs induced by cholesterol, which promoted the VSMC dedifferentiation. Our results showed that HRD1 played an essential role in the contractile homeostasis of VSMCs by negatively regulating ER stress response. Thus, HRD1 in VSMCs could serve as a potential therapeutic target in metabolic disorder-induced vascular remodeling.
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Disturbed endoplasmic reticulum (ER) stress response driven by the excessive lipid accumulation in the liver is a characteristic feature in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Restoring metabolic homeostasis by targeting ER stress is a potentially therapeutic strategy for NAFLD. Here we aim to identify novel proteins or pathways involved in regulating ER stress response and therapeutic targets for alleviating NAFLD. Proteomic and transcriptomic analysis demonstrated that major urinary proteins (MUPs) were significantly reduced in the livers from NAFLD mouse models. Then we confirmed that MUP1, the major secreted form of MUPs, was reduced at mRNA and protein expression levels in hepatocytes both in vivo and in vitro under ER stress. We further illustrated that MUP1 protein levels in the urine were reduced in mice with NAFLD, which was reversed by GLP-1 receptor agonist treatment. To study the relationship between ER stress and MUP1 biology, our analysis demonstrated that MUP1 was misfolded and trapped in the ER under ER stress in vivo. Interestingly, we discovered that recombinant MUP1 treatment in hepatocytes increased calcium efflux from the ER, which resulted in transient ER stress response, including reduced protein synthesis. These responses facilitated the alleviation of chemical induced ER stress in hepatocytes, which was suggested as "pre-adaptive ER stress". Besides, recombinant MUP1 pretreatment also improved ER stress-induced insulin resistance in hepatocytes. Our findings revealed a novel and critical role of MUP1, and recombinant MUP1 or its potential derivates may serve as a promising therapeutic target for alleviating NAFLD.
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Resistencia a la Insulina , Enfermedad del Hígado Graso no Alcohólico , Animales , Ratones , Estrés del Retículo Endoplásmico , Hepatocitos , Metabolismo de los Lípidos , Hígado , Ratones Endogámicos C57BL , Enfermedad del Hígado Graso no Alcohólico/metabolismo , ProteómicaRESUMEN
Hematopoietic stem cells (HSC) self-renew to sustain stem cell pools and differentiate to generate all types of blood cells. HSCs remain in quiescence to sustain their long-term self-renewal potential. It remains unclear whether protein quality control is required for stem cells in quiescence when RNA content, protein synthesis, and metabolic activities are profoundly reduced. Here, we report that protein quality control via endoplasmic reticulum-associated degradation (ERAD) governs the function of quiescent HSCs. The Sel1L/Hrd1 ERAD genes are enriched in the quiescent and inactive HSCs, and conditional knockout of Sel1L in hematopoietic tissues drives HSCs to hyperproliferation, which leads to complete loss of HSC self-renewal and HSC depletion. Mechanistically, ERAD deficiency via Sel1L knockout leads to activation of mammalian target of rapamycin (mTOR) signaling. Furthermore, we identify Ras homolog enriched in brain (Rheb), an activator of mTOR, as a novel protein substrate of Sel1L/Hrd1 ERAD, which accumulates upon Sel1L deletion and HSC activation. Importantly, inhibition of mTOR, or Rheb, rescues HSC defects in Sel1L knockout mice. Protein quality control via ERAD is, therefore, a critical checkpoint that governs HSC quiescence and self-renewal by Rheb-mediated restriction of mTOR activity.
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Proliferación Celular , Degradación Asociada con el Retículo Endoplásmico , Retículo Endoplásmico/metabolismo , Células Madre Hematopoyéticas/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Animales , Retículo Endoplásmico/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Ratones , Proteína Homóloga de Ras Enriquecida en el Cerebro/genética , Proteína Homóloga de Ras Enriquecida en el Cerebro/metabolismo , Serina-Treonina Quinasas TOR/genética , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
Oxyfunctionalization of toluene to value-added benzaldehyde, benzyl alcohol and benzoic acid is of great significance. In this work, Co-Schiff bases were immobilized on commercial silica gel by covalent anchoring, and resulting catalysts were used to catalyze the oxidation of toluene in the presence of the cocatalyst N-hydroxyphthalimide (NHPI). The catalysts exhibited excellent textural and structural properties, reliable bonding and a predomination of the cobaltous ions. The catalyst synthesized by diethylamino salicylaldehyde (EASA) possessed a grafting density of 0.14 mmol/g and exhibited a toluene conversion of 37.5%, with predominant selectivities to benzaldehyde, benzyl alcohol and benzoic acid under solvent-free conditions. It is concluded that the effect of ligands on their catalytic performance might be related to their electron-donating or -withdrawing properties.
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Bases de Schiff , Tolueno , Benzaldehídos , Ácido Benzoico/química , Alcohol Bencilo/química , Tolueno/químicaRESUMEN
Nanoscale bioactive glass particles have greater bioactivity than microscale bioactive glass particles, due to their high-specific surface area and fast ion release rate in body fluid. However, preparation of bioactive glass nanoparticles (BGNPs) is difficult since calcium is not easy to be highly doped into the forming silica atom network, leading to an uneven distribution and a low content of calcium. In addition, BGNPs are usually prepared in a dilute solution to avoid agglomeration of the nanoparticles, which decreases the production efficiency and increases the cost. In this work, BGNPs are prepared by a method of the reactive flash nanoprecipitation (RFNP) as well as a traditional sol-gel method. The results indicate that the BGNPs by the RFNP present a smaller size, narrower size distribution, more uniform composition, and better bioactivity than those by the traditional sol-gel method. The obtained BGNPs have uniform compositions close to the feed values. The high and even doping of calcium in the BGNPs is achieved. This successful doping of calcium into nanoparticles by the RFNP demonstrates a promising way to effectively generate high-quality BGNPs for bone repairs.
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Materiales Biocompatibles , Calcio/química , Precipitación Química , Vidrio , Nanopartículas/química , Iones , Ensayo de Materiales , Modelos Moleculares , Estructura MolecularRESUMEN
PURPOSE: To explore the correlation between hearing and speech recovery levels after cochlear implantation and examined the preoperative microstructure of auditory pathways and speech centre using DTI. METHODS: (1) Fifty-two SNHL children between 0 and 6 years and 19 age and gender matched normal hearing subjects had received 3.0 T-MRI examination of the brain.FA, axial diffusion coefficient (λâ), radial diffusion coefficient (λâ¥), and MD values in the lateral lemniscus, inferior colliculus, medial geniculate bodies, auditory radiations, Brodmann areas 41, 42, 22, 44, 45, and 39 were all measured bilaterally. (2) CAP and SIR scores were assessed in fourty-six cochlear implantation children at 6 months post-implant. Correlations among deaf children ages, FA value of bilateral inferior colliculus FA values, BA22, BA44, and postoperative CAP, and SIR scores were analyzed using multiple linear regression. RESULTS: The preoperative standard partial regression age coefficient of deaf children (|bi'| = 0.404) was slightly greater than that of the inferior colliculus (|bi'| = 0.377) FA value. CONCLUSION: Preoperative children ages and inferior colliculus FA values were important factors influencing postoperative CAP score. Inferior colliculus FA value is a vital influencing factor in rehabilitation after cochlear implantation.
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Vías Auditivas/fisiopatología , Implantes Cocleares , Pérdida Auditiva Sensorineural/congénito , Vías Auditivas/fisiología , Encéfalo/diagnóstico por imagen , Estudios de Casos y Controles , Niño , Preescolar , Implantación Coclear , Imagen de Difusión por Resonancia Magnética , Femenino , Pérdida Auditiva Sensorineural/fisiopatología , Pérdida Auditiva Sensorineural/rehabilitación , Pérdida Auditiva Sensorineural/cirugía , Pruebas Auditivas , Humanos , Lactante , Modelos Lineales , Masculino , Valores de Referencia , Habla , Percepción del Habla , Resultado del TratamientoRESUMEN
BACKGROUND: The aim of this study was to evaluate the predictive value of serum human epidermal growth factor 2 (HER2) for recurrence and metastasis in triple negative breast cancer (TNBC). METHODS: A total of 200 patients with benign breast tumors and 300 patients with breast cancer treated in the Department of Breast Surgery, Women and Children's Hospital of Ningbo City (China) between December 2006 and December 2013 were enrolled. Another 500 age- and gender-matched healthy individuals served as controls. The serum level of HER2 was determined using suspension array technology. Patients with breast cancer were further divided into ER-/PR-/HER2- and ER-/PR-/HER2+ groups and followed up for 5 years to analyze the serum concentration of HER2. RESULTS: The serum HER2 concentration was significantly higher in patients with breast cancer than in healthy controls or patients with benign tumors (both p < 0.01). The serum HER2 concentration also was significantly higher in patients with TNBC than in healthy controls (p < 0.01). The serum concentration of HER2 was significantly higher in TNBC patients who experienced recurrence and metastasis than in TNBC patients who did not experience recurrence and metastasis (both p < 0.01). Notably, the serum HER2 concentration in TNBC patients who experienced recurrence and metastasis was increased to a level statistically similar to that in patients with HER2+ breast cancer (p > 0.05). CONCLUSIONS: Patients with TNBC still have an increased serum HER2 concentration, and serum HER2 may be a valuable, novel biomarker for recurrence and metastasis in TNBC.
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Biomarcadores de Tumor/sangre , Recurrencia Local de Neoplasia , Receptor ErbB-2/sangre , Neoplasias de la Mama Triple Negativas/sangre , China , Femenino , Humanos , Metástasis de la Neoplasia , Valor Predictivo de las Pruebas , Ensayos Clínicos Controlados Aleatorios como Asunto , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento , Neoplasias de la Mama Triple Negativas/patología , Neoplasias de la Mama Triple Negativas/terapia , Regulación hacia ArribaRESUMEN
Suppressor/Enhancer of Lin-12-like (Sel1L) is an adaptor protein for the E3 ligase hydroxymethylglutaryl reductase degradation protein 1 (Hrd1) involved in endoplasmic reticulum-associated degradation (ERAD). Sel1L's physiological importance in mammalian ERAD, however, remains to be established. Here, using the inducible Sel1L knockout mouse and cell models, we show that Sel1L is indispensable for Hrd1 stability, ER homeostasis, and survival. Acute loss of Sel1L leads to premature death in adult mice within 3 wk with profound pancreatic atrophy. Contrary to current belief, our data show that mammalian Sel1L is required for Hrd1 stability and ERAD function both in vitro and in vivo. Sel1L deficiency disturbs ER homeostasis, activates ER stress, attenuates translation, and promotes cell death. Serendipitously, using a biochemical approach coupled with mass spectrometry, we found that Sel1L deficiency causes the aggregation of both small and large ribosomal subunits. Thus, Sel1L is an indispensable component of the mammalian Hrd1 ERAD complex and ER homeostasis, which is essential for protein translation, pancreatic function, and cellular and organismal survival.
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Degradación Asociada con el Retículo Endoplásmico , Retículo Endoplásmico/metabolismo , Homeostasis , Mamíferos/metabolismo , Proteínas/metabolismo , Animales , Atrofia , Técnicas de Cultivo de Célula , Muerte Celular , Proliferación Celular , Supervivencia Celular , Retículo Endoplásmico/ultraestructura , Péptidos y Proteínas de Señalización Intracelular , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Modelos Biológicos , Páncreas Exocrino/anomalías , Páncreas Exocrino/metabolismo , Páncreas Exocrino/patología , Páncreas Exocrino/ultraestructura , Polirribosomas/metabolismo , Biosíntesis de Proteínas , Estabilidad Proteica , Vesículas Secretoras/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Respuesta de Proteína DesplegadaRESUMEN
BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is characterised by accumulation of excessive triglycerides in the liver. Obesity is usually associated with NAFLD through an unknown mechanism. OBJECTIVE: To investigate the roles of Yin Yang 1 (YY1) in the progression of obesity-associated hepatosteatosis. METHODS: Expression levels of hepatic YY1 were identified by microarray analysis in high-fat-diet (HFD)-induced obese mice. Liver triglyceride metabolism was analysed in mice with YY1 overexpression and suppression. RESULTS: YY1 expression was markedly upregulated in HFD-induced obese mice and NAFLD patients. Overexpression of YY1 in healthy mice promoted hepatosteatosis under high-fat dietary conditions, whereas liver-specific ablation of YY1 using adenoviral shRNA ameliorated triglyceride accumulation in obese mice. At the molecular level, YY1 suppressed farnesoid X receptor (FXR) expression through binding to the YY1 responsive element at intron 1 of the FXR gene. CONCLUSIONS: These findings indicate that YY1 plays a crucial role in obesity-associated hepatosteatosis, through repression of FXR expression.
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Hígado Graso/etiología , Obesidad/metabolismo , Receptores Citoplasmáticos y Nucleares/metabolismo , Factor de Transcripción YY1/metabolismo , Animales , Biomarcadores/metabolismo , Western Blotting , Inmunoprecipitación de Cromatina , Hígado Graso/metabolismo , Humanos , Hígado/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Enfermedad del Hígado Graso no Alcohólico , Obesidad/complicaciones , Análisis de Secuencia por Matrices de Oligonucleótidos , Reacción en Cadena en Tiempo Real de la Polimerasa , Triglicéridos/metabolismo , Regulación hacia ArribaRESUMEN
SUMOylation has been considered as an important mechanism to regulate multiple cellular processes, including inflammation. TAB2 (TAK1-binding protein 2) is an upstream adaptor protein in the IL-1 signaling pathway. Covalent modifications of TAB2 have not been well studied. In this study, we demonstrated that TAB2 could be modified by SUMO. Using Ubc9 (SUMO-conjugating enzyme) fusion and mutation analysis, we identified evolutionarily conserved lysine 329 as the major SUMOylation site of TAB2. PIAS3, a SUMO E3 ligase, preferentially interacted with and promoted its SUMOylation. Interestingly, block of SUMOylation by mutation of lysine 329 enhanced the activity of TAB2, as reflected by AP-1 luciferase reporter assays. Taken together, these results suggest that SUMOylation may serve as a novel mechanism for the regulation of TAB2.
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Proteínas Adaptadoras Transductoras de Señales/metabolismo , Interleucina-1/metabolismo , Transducción de Señal , Sumoilación , Proteínas Adaptadoras Transductoras de Señales/química , Secuencia de Aminoácidos , Animales , Células HEK293 , Humanos , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Lisina/metabolismo , Ratones , Chaperonas Moleculares/metabolismo , Datos de Secuencia Molecular , Unión Proteica , Proteínas Inhibidoras de STAT Activados/metabolismoRESUMEN
Osteonecrosis of the femoral head is a severely disabling complication of steroid immunosuppression in renal transplant patients. The increased number of patients undergoing transplantation has increased the number of transplant recipients undergoing total hip replacement arthroplasty (THRA). In this study, we retrospectively assessed patients who underwent THRA from May 2004 to February 2014, and evaluated their demographic and clinical characteristics, the results of peri-operative laboratory tests, the amounts of fluids transfused during surgery, and anesthesia time. Our results found that post-operative acute kidney injury (AKI) was significantly associated with transplantation, and transplantation was an independent factor predictive of post-operative AKI, so transplant recipients are at risk for AKI following THRA. Total hip replacement is a safe and effective treatment for transplant recipients and, in view of their limited life expectancy, should be considered at an early stage in their treatment.
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Lesión Renal Aguda/etiología , Artroplastia de Reemplazo de Cadera/efectos adversos , Trasplante de Órganos/efectos adversos , Complicaciones Posoperatorias/etiología , Corticoesteroides/efectos adversos , Adulto , Anciano , Necrosis de la Cabeza Femoral/inducido químicamente , Necrosis de la Cabeza Femoral/cirugía , Humanos , Inmunosupresores/efectos adversos , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
During lagging strand chromatin replication, multiple Okazaki fragments (OFs) require processing and nucleosome assembly, but the mechanisms linking these processes remain unclear. Here, using transmission electron microscopy and rapid degradation of DNA ligase Cdc9, we observed flap structures accumulated on lagging strands, controlled by both Pol δ's strand displacement activity and Fen1's nuclease digestion. The distance between neighboring flap structures exhibits a regular pattern, indicative of matured OF length. While fen1Δ or enhanced strand displacement activities by polymerase δ (Pol δ; pol3exo-) minimally affect inter-flap distance, mutants affecting replication-coupled nucleosome assembly, such as cac1Δ and mcm2-3A, do significantly alter it. Deletion of Pol32, a subunit of DNA Pol δ, significantly increases this distance. Mechanistically, Pol32 binds to histone H3-H4 and is critical for nucleosome assembly on the lagging strand. Together, we propose that Pol32 establishes a connection between nucleosome assembly and the processing of OFs on lagging strands.
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ADN Polimerasa III , ADN , Histonas , Nucleosomas , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Nucleosomas/metabolismo , Histonas/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , ADN Polimerasa III/metabolismo , ADN Polimerasa III/genética , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , ADN/metabolismo , Replicación del ADN , Unión Proteica , ADN Polimerasa Dirigida por ADNRESUMEN
The prevalent RNA alternative splicing (AS) contributes to molecular diversity, which has been demonstrated in cellular function regulation and disease pathogenesis. However, the contribution of AS in pancreatic islets during diabetes progression remains unclear. Here, we reanalyze the full-length single-cell RNA sequencing data from the deposited database to investigate AS regulation across human pancreatic endocrine cell types in non-diabetic (ND) and type 2 diabetic (T2D) individuals. Our analysis demonstrates the significant association between transcriptomic AS profiles and cell-type-specificity, which could be applied to distinguish the clustering of major endocrine cell types. Moreover, AS profiles are enabled to clearly define the mature subset of ß-cells in healthy controls, which is completely lost in T2D. Further analysis reveals that RNA-binding proteins (RBPs), heterogeneous nuclear ribonucleoproteins (hnRNPs) and FXR1 family proteins are predicted to induce the functional impairment of ß-cells through regulating AS profiles. Finally, trajectory analysis of endocrine cells suggests the ß-cell identity shift through dedifferentiation and transdifferentiation of ß-cells during the progression of T2D. Together, our study provides a mechanism for regulating ß-cell functions and suggests the significant contribution of AS program during diabetes pathogenesis.
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Empalme Alternativo , Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Análisis de Secuencia de ARN , Análisis de la Célula Individual , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patología , Transcriptoma , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Islotes Pancreáticos/metabolismo , Islotes Pancreáticos/patologíaRESUMEN
Global temperatures have risen as a result of climate change, and the resulting warmer seawater will exert physiological stresses on many aquatic animals, including Apostichopus japonicus. It has been suggested that the sensitivity of aquatic poikilothermal animals to climate change is closely related to mitochondrial function. Therefore, understanding the interaction between elevated temperature and mitochondrial functioning is key to characterizing organisms' responses to heat stress. However, little is known about the mitochondrial response to heat stress in A. japonicus. In this work, we investigated the morphological and functional changes of A. japonicus mitochondria under three representative temperatures, control temperature (18 °C), aestivation temperature (25 °C) and heat stress temperature (32 °C) temperatures using transmission electron microscopy (TEM) observation of mitochondrial morphology combined with proteomics and metabolomics techniques. The results showed that the mitochondrial morphology of A. japonicus was altered, with decreases in the number of mitochondrial cristae at 25 °C and mitochondrial lysis, fracture, and vacuolization at 32 °C. Proteomic and metabolomic analyses revealed 103 differentially expressed proteins and 161 differential metabolites at 25 °C. At 32 °C, the levels of 214 proteins and 172 metabolites were significantly altered. These proteins and metabolites were involved in the tricarboxylic acid (TCA) cycle, substance transport, membrane potential homeostasis, anti-stress processes, mitochondrial autophagy, and apoptosis. Furthermore, a hypothetical network of proteins and metabolites in A. japonicus mitochondria in response to temperature changes was constructed based on proteomic and metabolomic data. These results suggest that the dynamic regulation of mitochondrial energy metabolism, resistance to oxidative stress, autophagy, apoptosis, and mitochondrial morphology in A. japonicus may play important roles in the response to elevated temperatures. In summary, this study describes the response of A. japonicus mitochondria to temperature changes from the perspectives of morphology, proteins, and metabolites, which provided a better understanding the mechanisms of mitochondrial regulation under environment stress in marine echinoderms.