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1.
Proc Natl Acad Sci U S A ; 118(14)2021 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-33811139

RESUMEN

One third of the western population suffers from nonalcoholic fatty liver disease (NAFLD), which may ultimately develop into hepatocellular carcinoma (HCC). The molecular event(s) that triggers the disease are not clear. Current understanding, known as the multiple hits model, suggests that NAFLD is a result of diverse events at several tissues (e.g., liver, adipose tissues, and intestine) combined with changes in metabolism and microbiome. In contrast to this prevailing concept, we report that fatty liver could be triggered by a single mutated protein expressed only in the liver. We established a transgenic system that allows temporally controlled activation of the MAP kinase p38α in a tissue-specific manner by induced expression of intrinsically active p38α allele. Here we checked the effect of exclusive activation in the liver. Unexpectedly, induction of p38α alone was sufficient to cause macrovesicular fatty liver. Animals did not become overweight, showing that fatty liver can be imposed solely by a genetic modification in liver per se and can be separated from obesity. Active p38α-induced fatty liver is associated with up-regulation of MUC13, CIDEA, PPARγ, ATF3, and c-jun mRNAs, which are up-regulated in human HCC. Shutting off expression of the p38α mutant resulted in reversal of symptoms. The findings suggest that p38α plays a direct causative role in fatty liver diseases and perhaps in other chronic inflammatory diseases. As p38α activity was induced by point mutations, it could be considered a proto-inflammatory gene (proto-inflammagene).


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/genética , Factor de Transcripción Activador 3/genética , Factor de Transcripción Activador 3/metabolismo , Animales , Antígenos de Superficie/genética , Antígenos de Superficie/metabolismo , Factor de Crecimiento Epidérmico/genética , Factor de Crecimiento Epidérmico/metabolismo , Mutación con Ganancia de Función , Proteínas Quinasas JNK Activadas por Mitógenos/genética , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Ratones , Ratones Endogámicos C57BL , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/patología , PPAR gamma/genética , PPAR gamma/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
2.
BMC Biol ; 20(1): 222, 2022 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-36199058

RESUMEN

BACKGROUND: Progesterone receptor (PGR) is a master regulator of uterine function through antagonistic and synergistic interplays with oestrogen receptors. PGR action is primarily mediated by activation functions AF1 and AF2, but their physiological significance is unknown. RESULTS: We report the first study of AF1 function in mice. The AF1 mutant mice are infertile with impaired implantation and decidualization. This is associated with a delay in the cessation of epithelial proliferation and in the initiation of stromal proliferation at preimplantation. Despite tissue selective effect on PGR target genes, AF1 mutations caused global loss of the antioestrogenic activity of progesterone in both pregnant and ovariectomized models. Importantly, the study provides evidence that PGR can exert an antioestrogenic effect by genomic inhibition of Esr1 and Greb1 expression. ChIP-Seq data mining reveals intermingled PGR and ESR1 binding on Esr1 and Greb1 gene enhancers. Chromatin conformation analysis shows reduced interactions in these genes' loci in the mutant, coinciding with their upregulations. CONCLUSION: AF1 mediates genomic inhibition of ESR1 action globally whilst it also has tissue-selective effect on PGR target genes.


Asunto(s)
Progesterona , Receptores de Progesterona , Animales , Cromatina/metabolismo , Endometrio/metabolismo , Estrógenos/metabolismo , Estrógenos/farmacología , Femenino , Furilfuramida/metabolismo , Furilfuramida/farmacología , Ratones , Embarazo , Progesterona/metabolismo , Progesterona/farmacología , Receptores de Estrógenos/genética , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/genética , Receptores de Progesterona/metabolismo , Útero/metabolismo
3.
J Immunol ; 204(10): 2712-2721, 2020 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-32269097

RESUMEN

C-reactive protein (CRP) can increase up to 1000-fold in blood and form complexes with very low density lipoproteins (VLDL). These complexes are associated with worse outcomes for septic patients, and this suggests a potential pathological role in sepsis. Complex formation is heightened when CRP is over 200 mg/l and levels are associated with the severity of sepsis and blood bacterial culture positivity. Using a mouse bacteremia model, blood bacterial clearance can be delayed by i.v. injection of CRP-VLDL complexes. Complexes are more efficiently taken up by activated U937 cells in vitro and Kupffer cells in vivo than VLDL alone. Both in vitro-generated and naturally occurring CRP-VLDL complexes reduce phagocytosis of bacteria by activated U937 cells. Fcγ and scavenger receptors are involved and a competitive mechanism for clearance of CRP-VLDL complexes and bacteria is demonstrated. Interaction of phosphocholine groups on VLDL with CRP is the major driver for complex formation and phosphocholine can disrupt the complexes to reverse their inhibitory effects on phagocytosis and bacterial clearance. Increased formation of CRP-VLDL complexes is therefore harmful and could be a novel target for therapy in sepsis.


Asunto(s)
Bacteriemia/metabolismo , Proteína C-Reactiva/metabolismo , Macrófagos del Hígado/fisiología , Lipoproteínas VLDL/metabolismo , Sepsis/metabolismo , Anciano , Animales , Proteína C-Reactiva/genética , Modelos Animales de Enfermedad , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Mutación/genética , Fagocitosis , Fosforilcolina/metabolismo , Unión Proteica , Receptores de IgG/metabolismo , Células U937
4.
Br J Anaesth ; 128(2): 283-293, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34893315

RESUMEN

BACKGROUND: Neutrophil extracellular traps (NETs) facilitate bacterial clearance but also promote thrombosis and organ injury in sepsis. We quantified ex vivo NET induction in septic humans and murine models of sepsis to identify signalling pathways that may be modulated to improve outcome in human sepsis. METHODS: NET formation in human donor neutrophils was quantified after incubation with plasma obtained from patients with sepsis or systemic inflammation (double-blinded assessment of extracellular DNA using immunofluorescence microscopy). NET formation (% neutrophils forming NETs) was correlated with plasma cytokine levels (MultiPlex assay). Experimental sepsis (caecal ligation and puncture or intraperitoneal injection of Escherichia coli) was assessed in C57/BL6 male mice. The effect of pharmacological inhibition of CXCR1/2 signalling (reparixin) on NET formation, organ injury (hepatic, renal, and cardiac biomarkers), and survival in septic mice was examined. RESULTS: NET formation was higher after incubation with plasma from septic patients (median NETs=25% [10.5-46.5%]), compared with plasma obtained from patients with systemic inflammation (14% [4.0-23.3%]; P=0.02). Similar results were observed after incubation of plasma from mice with neutrophils from septic non-septic mice. Circulating CXCR1/2 ligands correlated with NETosis in patients (interleukin-8; r=0.643) and mice (macrophage inflammatory protein-2; r=0.902). In experimental sepsis, NETs were primarily observed in the lungs, correlating with fibrin deposition (r=0.702) and lung injury (r=0.692). Inhibition of CXCR1/2 using reparixin in septic mice reduced NET formation, multi-organ injury, and mortality, without impairing bacterial clearance. CONCLUSION: CXCR1/2 signalling-induced NET formation is a therapeutic target in sepsis, which may be guided by ex vivo NET assays.


Asunto(s)
Trampas Extracelulares/metabolismo , Inflamación/complicaciones , Sepsis/complicaciones , Sulfonamidas/farmacología , Trombosis/prevención & control , Animales , Citocinas/metabolismo , Modelos Animales de Enfermedad , Humanos , Inflamación/tratamiento farmacológico , Lesión Pulmonar/etiología , Lesión Pulmonar/prevención & control , Masculino , Ratones , Ratones Endogámicos C57BL , Neutrófilos/metabolismo , Receptores de Interleucina-8A/antagonistas & inhibidores , Receptores de Interleucina-8B/antagonistas & inhibidores , Estudios Retrospectivos , Sepsis/tratamiento farmacológico , Sepsis/mortalidad , Trombosis/etiología
5.
J Nanobiotechnology ; 20(1): 214, 2022 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-35524277

RESUMEN

Immunotherapy has gradually emerged as the most promising anticancer therapy. In addition to conventional anti-PD-1/PD-L1 therapy, anti-CTLA-4 therapy, CAR-T therapy, etc., immunotherapy can also be induced by stimulating the maturation of immune cells or inhibiting negative immune cells, regulating the tumor immune microenvironment and cancer vaccines. Lipid nanovesicle drug delivery system includes liposomes, cell membrane vesicles, bacterial outer membrane vesicles, extracellular vesicles and hybrid vesicles. Lipid nanovesicles can be used as functional vesicles for cancer immunotherapy, and can also be used as drug carriers to deliver immunotherapy drugs to the tumor site for cancer immunotherapy. Here, we review recent advances in five kinds of lipid nanovesicles in cancer immunotherapy and assess the clinical application prospects of various lipid nanovesicles, hoping to provide valuable information for clinical translation in the future.


Asunto(s)
Inmunoterapia , Neoplasias , Sistemas de Liberación de Medicamentos , Humanos , Lípidos , Neoplasias/tratamiento farmacológico , Microambiente Tumoral
6.
BMC Nephrol ; 23(1): 319, 2022 09 23.
Artículo en Inglés | MEDLINE | ID: mdl-36138351

RESUMEN

BACKGROUND: Sarcopenia is associated with various adverse outcomes in hemodialysis patients. However, current tools for assessing and diagnosing sarcopenia have limited applicability. In this study, we aimed to develop a simple and reliable nomogram to predict the risk of sarcopenia in hemodialysis patients that could assist physicians identify high-risk patients early. METHODS: A total of 615 patients undergoing hemodialysis at the First Affiliated Hospital College of Medicine Zhejiang University between March to June 2021 were included. They were randomly divided into either the development cohort (n = 369) or the validation cohort (n = 246). Multivariable logistic regression analysis was used to screen statistically significant variables for constructing the risk prediction nomogram for Sarcopenia. The line plots were drawn to evaluate the effectiveness of the nomogram in three aspects, namely differentiation, calibration, and clinical net benefit, and were further validated by the Bootstrap method. RESULTS: The study finally included five clinical factors to construct the nomogram, including age, C-reactive protein, serum phosphorus, body mass index, and mid-upper arm muscle circumference, and constructed a nomogram. The area under the ROC curve of the line chart model was 0.869, with a sensitivity and specificity of 77% sensitivity and 83%, the Youden index was 0.60, and the internal verification C-statistic was 0.783. CONCLUSIONS: This study developed and validated a nomogram model to predict the risk of sarcopenia in hemodialysis patients, which can be used for early identification and timely intervention in high-risk groups.


Asunto(s)
Nomogramas , Sarcopenia , Proteína C-Reactiva , Humanos , Fósforo , Diálisis Renal/efectos adversos , Estudios Retrospectivos , Sarcopenia/diagnóstico , Sarcopenia/epidemiología
7.
Neurobiol Dis ; 153: 105313, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33636388

RESUMEN

Vacuolar protein sorting protein 35 (VPS35) is a core component of the retromer complex involved in regulating protein trafficking and retrieval. Recently, a missense mutation, Asp620Asn (D620N), in VPS35 (PARK17) has been identified as a pathogenic mutation for late-onset autosomal dominant Parkinson's disease (PD). Although PD is characterized by a range of motor symptoms associated with loss of dopaminergic neurons in the substantial nigra, non-motor symptoms such as impaired hippocampal neurogenesis were observed in both PD patients and animal models of PD caused by multiple PD-linked pathogenic genes such as alpha-synuclein and leucine-rich repeat kinase 2 (LRRK2). However, the role of the VPS35 D620N mutation in adult hippocampal neurogenesis remains unknown. Here, we showed that the VPS35 D620N mutation impaired hippocampal neurogenesis in adult transgenic mice expressing the VPS35 D620N gene. Specifically, we showed a reduction in the neural stem cell pool and neural proliferation and differentiation, retarded migration, and impaired neurite outgrowth in 3-month-old VPS35 D620N mutant mice. Moreover, we found that the VPS35 D620N mutant hyperphosphorylates amyloid precursor protein (APP) at Thr668and interacts with APP. Notably, by crossing the VPS35 D620N mutant mice with APP knockout (KO) mice, we showed that loss of APP function rescues VPS35 D620N-inhibited neurogenesis, neural migration, and maturation. Our study provides important evidence that APP is involved in the VPS35 D620N mutation in regulating adult neurogenesis, which sheds light on the pathogenic mechanisms in PD.


Asunto(s)
Precursor de Proteína beta-Amiloide/genética , Hipocampo/metabolismo , Neurogénesis/genética , Trastornos Parkinsonianos/genética , Proteínas de Transporte Vesicular/genética , Animales , Humanos , Ratones , Ratones Noqueados , Ratones Transgénicos
8.
J Nanobiotechnology ; 19(1): 147, 2021 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-34011362

RESUMEN

BACKGROUND: Triple negative breast cancer (TNBC) is an aggressive tumor with extremely high mortality that results from its lack of effective therapeutic targets. As an adhesion molecule related to tumorigenesis and tumor metastasis, cluster of differentiation-44 (also known as CD44) is overexpressed in TNBC. Moreover, CD44 can be effectively targeted by a specific hyaluronic acid analog, namely, chitosan oligosaccharide (CO). In this study, a CO-coated liposome was designed, with Photochlor (HPPH) as the 660 nm light mediated photosensitizer and evofosfamide (also known as TH302) as the hypoxia-activated prodrug. The obtained liposomes can help diagnose TNBC by fluorescence imaging and produce antitumor therapy by synergetic photodynamic therapy (PDT) and chemotherapy. RESULTS: Compared with the nontargeted liposomes, the targeted liposomes exhibited good biocompatibility and targeting capability in vitro; in vivo, the targeted liposomes exhibited much better fluorescence imaging capability. Additionally, liposomes loaded with HPPH and TH302 showed significantly better antitumor effects than the other monotherapy groups both in vitro and in vivo. CONCLUSION: The impressive synergistic antitumor effects, together with the superior fluorescence imaging capability, good biocompatibility and minor side effects confers the liposomes with potential for future translational research in the diagnosis and CD44-overexpressing cancer therapy, especially TNBC.


Asunto(s)
Quitosano/farmacología , Liposomas/química , Nitroimidazoles/farmacología , Oligosacáridos/farmacología , Mostazas de Fosforamida/farmacología , Fotoquimioterapia/métodos , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Quitosano/química , Femenino , Humanos , Receptores de Hialuranos , Ácido Hialurónico , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Nanomedicina , Nitroimidazoles/química , Oligosacáridos/química , Imagen Óptica , Mostazas de Fosforamida/química , Fármacos Fotosensibilizantes/química , Profármacos/química , Neoplasias de la Mama Triple Negativas/patología
9.
Mediators Inflamm ; 2020: 7418342, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32934605

RESUMEN

The pathological roles of bacterial DNA have been documented many decades ago. Bacterial DNAs are different from mammalian DNAs; the latter are heavily methylated. Mammalian cells have sensors such as TLR-9 to sense the DNAs with nonmethylated CpGs and distinguish them from host DNAs with methylated CpGs. Further investigation has identified many other types of DNA sensors distributed in a variety of cellular compartments. These sensors not only sense foreign DNAs, including bacterial and viral DNAs, but also sense damaged DNAs from the host cells. The major downstream signalling pathways includeTLR-9-MyD88-IKKa-IRF-7/NF-κB pathways to increase IFN/proinflammatory cytokine production, STING-TBK1-IRF3 pathway to increase IFN-beta, and AIM2-ASC-caspas-1 pathway to release IL-1beta. The major outcome is to activate host immune response by inducing cytokine production. In this review, we focus on the roles and potential mechanisms of DNA sensors and downstream pathways in sepsis. Although bacterial DNAs play important roles in sepsis development, bacterial DNAs alone are unable to cause severe disease nor lead to death. Priming animals with bacterial DNAs facilitate other pathological factors, such as LPS and other virulent factors, to induce severe disease and lethality. We also discuss compartmental distribution of DNA sensors and pathological significance as well as the transport of extracellular DNAs into cells. Understanding the roles of DNA sensors and signal pathways will pave the way for novel therapeutic strategies in many diseases, particularly in sepsis.


Asunto(s)
ADN Bacteriano/metabolismo , FN-kappa B/metabolismo , Sepsis/metabolismo , Animales , Humanos , Transducción de Señal/fisiología
10.
J Med Internet Res ; 22(5): e13294, 2020 05 26.
Artículo en Inglés | MEDLINE | ID: mdl-32348253

RESUMEN

BACKGROUND: For the last decade, doctor-patient contradiction in China has remained prominent, and workplace violence toward medical staff still occurs frequently. However, little is known about the types and laws of propagation of violence against medical staff online. OBJECTIVE: By using a self-organizing map (SOM), we aimed to explore the microblog propagation law for violent incidents in China that involve medical staff, to classify the types of incidents and provide a basis for rapidly and accurately predicting trends in public opinion and developing corresponding measures to improve the relationship between doctors and patients. METHODS: For this study, we selected 60 cases of violent incidents in China involving medical staff that led to heated discussions on the Sina microblog from 2011 to 2018, searched the web data of the microblog using crawler software, recorded the amount of new tweets every 2 hours, and used the SOM neural network to cluster the number of tweets. Polynomial and exponential functions in MATLAB software were applied to predict and analyze the data. RESULTS: Trends in the propagation of online public opinion regarding the violent incidents were categorized into 8 types: bluff, waterfall, zigzag, steep, abrupt, wave, steep slope, and long slope. The communications exhibited different characteristics. The prediction effect of 4 types of incidents (ie, bluff, waterfall, zigzag, and steep slope) was good and accorded with actual spreading trends. CONCLUSIONS: Our study found that the more serious the consequences of a violent incident, such as a serious injury or death, the more attention it drew on the microblog, the faster was its propagation speed, and the longer was its duration. In these cases, the propagation types were mostly steep slope, long slope, and zigzag. In addition, the more serious the consequences of a violent incident, the higher popularity it exhibited on the microblog. The popularity within a week was significantly higher for acts resulting from patients' dissatisfaction with treatments than for acts resulting from nontherapeutic incidents.


Asunto(s)
Blogging/normas , Estudios de Evaluación como Asunto , Cuerpo Médico/psicología , Automanejo/psicología , Violencia/clasificación , China , Comunicación , Femenino , Humanos , Masculino , Opinión Pública , Violencia/psicología
11.
Crit Care Med ; 47(8): e677-e684, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31162199

RESUMEN

OBJECTIVES: Multiple organ dysfunction syndrome is characterized by simultaneous multiple organ failure, which is the leading cause of death in acute critically ill patients. However, what mediates multiple organ dysfunction syndrome is not fully understood. The discovery of toxic effects by extracellular histones on different individual organs strongly suggests their involvement in multiple organ dysfunction syndrome. In this study, we investigate whether circulating histones are major mediators of multiple organ dysfunction syndrome in acute critical illnesses. DESIGN: Combination of retrospective clinical studies and animal models with intervention. SETTING: ICU in a tertiary hospital and research laboratories. PATIENTS: Four hundred and twenty ICU patients, including sepsis (140), severe trauma (63), severe pancreatitis (89), and other admission diagnoses (128). LABORATORY INVESTIGATION: Cells from major organs are treated with calf thymus histones or histone-containing sera. Animal models for sepsis, trauma, and acute pancreatitis are treated with antihistone reagents. INTERVENTION: Antihistone reagents in in vitro, ex vivo, and animal models. MEASUREMENT AND MAIN RESULTS: Retrospective analysis of a prospectively recruited ICU cohort demonstrated a strong correlation between circulating histones and organ injury markers and Sequential Organ Failure Assessment scores. Ex vivo experiments showed that patient sera containing high histone levels were toxic to cultured cells from different origins, suggesting their universal toxicity to multiple organs. Animal models of sepsis, trauma, and pancreatitis further demonstrated a temporal correlation between histone levels and disease severity and multiple organ injury. Importantly, antihistone reagents, that is, antihistone single-chain variable fragment and nonanticoagulant heparin, could dramatically reduce multiple organ injury, particularly of the heart and lungs, and improve survival in mouse models. CONCLUSIONS: High levels of circulating histones are major mediators of multiple organ dysfunction syndrome. Our results indicate that monitoring upon ICU admission could inform on disease severity and developing antihistone therapy holds great potential of reducing multiple organ dysfunction syndrome and improving survival of critically ill patients.


Asunto(s)
Enfermedad Crítica , Histonas/sangre , Insuficiencia Multiorgánica/sangre , Sepsis/sangre , Biomarcadores/sangre , Humanos , Unidades de Cuidados Intensivos , Puntuaciones en la Disfunción de Órganos , Estudios Retrospectivos
12.
Cancer Cell Int ; 19: 17, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30675128

RESUMEN

BACKGROUND: In our previous study, we demonstrated that Sirtuin 6 (SIRT6) is upregulated and associated with papillary thyroid cancer (PTC) progression (Qu et al. in Int J Oncol 50(5):1683-92, 2017). This study examined whether SIRT6 promotes epithelial-mesenchymal transition (EMT) of papillary thyroid cancer through hypoxia inducible factor-1α (HIF-1α). METHODS: SIRT6-upregulated TPC-1 and B-CPAP cells were generated by lentivirus. Western blotting, RT-qPCR, immunofluorescence was performed to detect the following EMT associated markers: E-cadherin, Vimentin, Snail, and TWIST. Cell proliferation was detected by CCK8, and cell invasion and migration were detected by transwell and wound healing assays, respectively. HIF-1α expression was further detected by western blotting in both normoxia and hypoxia conditions. A HIF-1α inhibitor was then used to block HIF-1α expression in SIRT6-upregulated PTC cells. The same parameters were then assessed and compared with control HIF-1α cells. RESULTS: E-cadherin was significantly decreased, whereas Vimentin, Snail, and TWIST were increased in SIRT6-upregulated PTC cells. Additionally, SIRT6 promoted the invasion and migration of PTC cells. We found that SIRT6 enhanced HIF-1α stability and synthesis and prolonged the protein half-life. The changes in the EMT associated markers and in the invasion and migration ability were rescued after inhibition of HIF-1α expression. Furthermore, we found that SIRT6 increased PTC resistance to HIF-1α inhibitor-mediated proliferation changes. CONCLUSION: These results confirm that the SIRT6/HIF-1α axis promotes papillary thyroid cancer progression by inducing EMT.

15.
J Labelled Comp Radiopharm ; 61(3): 272-290, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29143354

RESUMEN

Fluorine-18 and iodine-123 labeled nonnatural alicyclic and methyl branched disubstituted α,α-amino acids are a diverse and useful class of tumor imaging agents suitable for positron emission tomography and single photon emission computed tomography. These tracers target the increased expression of the cell membrane amino acid transporter systems L, ASC, and A exhibited by many human tumor cells. The most established clinical use for these radiolabeled amino acids is imaging primary and recurrent gliomas and primary, recurrent, and metastatic prostate cancer. This review focuses on the synthesis, radiolabeling, and amino acid transport mechanism of a series of nonnatural fluorine-18 and iodine-123 labeled analogs of 1-aminocyclobutane-1-carboxylic acid, 1-aminocyclopentane-1-carboxylic acid, α-aminoisobutyric acid, and α-methylaminoisobutyric acid.


Asunto(s)
Sistemas de Transporte de Aminoácidos/metabolismo , Radioisótopos de Flúor/química , Radioisótopos de Yodo/química , Radiofármacos/síntesis química , Aminoácidos/química , Animales , Humanos , Radiofármacos/farmacocinética , Tomografía Computarizada de Emisión de Fotón Único/métodos
16.
Mol Biol Evol ; 33(2): 311-5, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26545918

RESUMEN

The brain, comprising billions of neurons and intricate neural networks, is arguably the most complex organ in vertebrates. The diversity of individual neurons is fundamental to the neuronal network complexity and the overall function of the vertebrate brain. In jawed vertebrates, clustered protocadherins provide the molecular basis for this neuronal diversity, through stochastic and combinatorial expression of their various isoforms in individual neurons. Based on analyses of transcriptomes from the Japanese lamprey brain and sea lamprey embryos, genome assemblies of the two lampreys, and brain expressed sequence tags of the inshore hagfish, we show that extant jawless vertebrates (cyclostomes) lack the clustered protocadherins. Our findings indicate that the clustered protocadherins originated from a nonclustered protocadherin in the jawed vertebrate ancestor, after the two rounds of whole-genome duplication. In the absence of clustered protocadherins, cyclostomes might have evolved novel molecules or mechanisms for generating neuronal diversity which remains to be discovered.


Asunto(s)
Cadherinas/genética , Lampreas/anatomía & histología , Lampreas/genética , Familia de Multigenes , Animales , Cadherinas/química , Orden Génico , Genoma , Humanos , Maxilares , Vertebrados
17.
J Physiol ; 594(12): 3391-406, 2016 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-26857341

RESUMEN

KEY POINTS: Regulation of ion channel function during repeated firing of action potentials is commonly observed in excitable cells. Recently it was shown that muscle activity is associated with rapid, protein kinase C (PKC)-dependent ClC-1 Cl(-) channel inhibition in rodent muscle. While this PKC-dependent ClC-1 inhibition during muscle activity was shown to be important for the maintenance of contractile endurance in rat muscle it is unknown whether a similar regulation exists in human muscle. Also, the molecular mechanisms underlying the observed PKC-dependent ClC-1 inhibition are unclear. Here we present the first demonstration of ClC-1 inhibition in active human muscle fibres, and we determine the changes in ClC-1 gating that underlie the PKC-dependent ClC-1 inhibition in active muscle using human ClC-1 expressed in Xenopus oocytes. This activity-induced ClC-1 inhibition is suggested to represent a mechanism by which human muscle fibres maintain their excitability during sustained activity. ABSTRACT: Repeated firing of action potentials (APs) is known to trigger rapid, protein kinase C (PKC)-dependent inhibition of ClC-1 Cl(-) ion channels in rodent muscle and this inhibition is important for contractile endurance. It is currently unknown whether similar regulation exists in human muscle, and the molecular mechanisms underlying PKC-dependent ClC-1 inhibition are unclear. This study first determined whether PKC-dependent ClC-1 inhibition exists in active human muscle, and second, it clarified how PKC alters the gating of human ClC-1 expressed in Xenopus oocytes. In human abdominal and intercostal muscles, repeated AP firing was associated with 30-60% reduction of ClC-1 function, which could be completely prevented by PKC inhibition (1 µm GF109203X). The role of the PKC-dependent ClC-1 inhibition was evaluated from rheobase currents before and after firing 1000 APs: while rheobase current was well maintained after activity under control conditions it rose dramatically if PKC-dependent ClC-1 inhibition had been prevented with the inhibitor. This demonstrates that the ClC-1 inhibition is important for maintenance of excitability in active human muscle fibres. Oocyte experiments showed that PKC activation lowered the overall open probability of ClC-1 in the voltage range relevant for AP initiation in muscle fibres. More detailed analysis of this reduction showed that PKC mostly affected the slow gate of ClC-1. Indeed, there was no effect of PKC activation in C277S mutated ClC-1 in which the slow gate is effectively locked open. It is concluded that regulation of excitability of active human muscle fibres relies on PKC-dependent ClC-1 inhibition via a gating mechanism.


Asunto(s)
Músculos Abdominales/fisiología , Canales de Cloruro/fisiología , Músculos Intercostales/fisiología , Activación del Canal Iónico/fisiología , Proteína Quinasa C/fisiología , Potenciales de Acción , Animales , Canales de Cloruro/genética , Femenino , Humanos , Oocitos , Xenopus laevis
18.
Mol Carcinog ; 55(5): 420-30, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-25648304

RESUMEN

Study investigated the ability of docosahexaenoic acid (DHA) alone and in combination with gamma-tocotrienol (γT3) to eliminate aldehyde dehydrogenase positive (ALDH+) cells and to inhibit mammosphere formation, biomarker and functional assay for tumor initiating cells (TICs), respectively, in human triple negative breast cancer cells (TNBCs), and investigated possible mechanisms of action. DHA upregulated Src homology region 2 domain-containing protein tyrosine phosphatase-1 (SHP-1) protein levels and suppressed levels of phosphorylated signal transducer and activator of transcription-3 (pStat3) and its downstream mediators c-Myc, and cyclin D1. siRNA to SHP-1 enhanced the percentage of ALDH+ cells and Stat-3 signaling, as well as inhibited, in part, the ability of DHA to reduce the percentage of ALDH+ cells and Stat-3 signaling. γT3 alone and in combination with DHA reduced ALDH+ TNBCs, up-regulated SHP-1 protein levels, and suppressed Stat-3 signaling. Taken together, data demonstrate the anti-TIC potential of achievable concentrations of DHA alone as well as in combination with γT3.


Asunto(s)
Aldehído Deshidrogenasa/metabolismo , Cromanos/farmacología , Ácidos Docosahexaenoicos/farmacología , Células Madre Neoplásicas/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Neoplasias de la Mama Triple Negativas/enzimología , Vitamina E/análogos & derivados , Protocolos de Quimioterapia Combinada Antineoplásica , Línea Celular Tumoral , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Células Madre Neoplásicas/enzimología , Fosforilación/efectos de los fármacos , Proteína Tirosina Fosfatasa no Receptora Tipo 6/metabolismo , Factor de Transcripción STAT3/metabolismo , Neoplasias de la Mama Triple Negativas/metabolismo , Vitamina E/farmacología
19.
Am J Respir Crit Care Med ; 187(2): 160-9, 2013 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-23220920

RESUMEN

RATIONALE: Acute lung injury is a common complication after severe trauma, which predisposes patients to multiple organ failure. This syndrome largely accounts for the late mortality that arises and despite many theories, the pathological mechanism is not fully understood. Discovery of histone-induced toxicity in mice presents a new dimension for elucidating the underlying pathophysiology. OBJECTIVES: To investigate the pathological roles of circulating histones in trauma-induced lung injury. METHODS: Circulating histone levels in patients with severe trauma were determined and correlated with respiratory failure and Sequential Organ Failure Assessment (SOFA) scores. Their cause-effect relationship was studied using cells and mouse models. MEASUREMENTS AND MAIN RESULTS: In a cohort of 52 patients with severe nonthoracic blunt trauma, circulating histones surged immediately after trauma to levels that were toxic to cultured endothelial cells. The high levels were significantly associated with the incidence of acute lung injury and SOFA scores, as well as markers of endothelial damage and coagulation activation. In in vitro systems, histones damaged endothelial cells, stimulated cytokine release, and induced neutrophil extracellular trap formation and myeloperoxidase release. Cellular toxicity resulted from their direct membrane interaction and resultant calcium influx. In mouse models, cytokines and markers for endothelial damage and coagulation activation significantly increased immediately after trauma or histone infusion. Pathological examinations showed that lungs were the predominantly affected organ with edema, hemorrhage, microvascular thrombosis, and neutrophil congestion. An anti-histone antibody could reduce these changes and protect mice from histone-induced lethality. CONCLUSIONS: This study elucidates a new mechanism for acute lung injury after severe trauma and proposes that circulating histones are viable therapeutic targets for improving survival outcomes in patients.


Asunto(s)
Lesión Pulmonar Aguda/etiología , Histonas/sangre , Heridas no Penetrantes/complicaciones , Lesión Pulmonar Aguda/sangre , Lesión Pulmonar Aguda/fisiopatología , Animales , Calcio/metabolismo , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/fisiología , Histonas/farmacología , Histonas/fisiología , Humanos , Pulmón/efectos de los fármacos , Pulmón/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Neutrófilos/efectos de los fármacos , Neutrófilos/fisiología , Puntuaciones en la Disfunción de Órganos , Peroxidasa/metabolismo , Insuficiencia Respiratoria/sangre , Insuficiencia Respiratoria/etiología , Insuficiencia Respiratoria/fisiopatología , Heridas no Penetrantes/sangre , Heridas no Penetrantes/fisiopatología
20.
Br J Hosp Med (Lond) ; 85(9): 1-21, 2024 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-39347660

RESUMEN

The incidence and lethality of hepatocellular carcinoma (HCC) are increasing annually, and traditional treatments have been proven to be ineffective for patients with advanced stages of the disease. In recent years, immune checkpoint therapy has rapidly evolved, demonstrating promising results across a wide range of cancers and offering new hope for cancer treatment. However, the efficacy of immune checkpoint therapy in HCC varies greatly among individuals, with only a small proportion of HCC patients responding positively. A major cause of immune resistance and poor efficacy in HCC patients is immune evasion, which is often due to insufficient infiltration of immune cells. Understanding the mechanisms underlying immune evasion is crucial for enhancing the efficacy of immune therapies. In this review, we aim to summarize the mechanisms of immune evasion observed during immune checkpoint therapy and discuss future directions for this therapeutic approach. Our goal is to provide insights that could help overcome immune evasion, thereby improving the efficacy of immune therapies and extending patient survival time.


Asunto(s)
Carcinoma Hepatocelular , Inhibidores de Puntos de Control Inmunológico , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/terapia , Carcinoma Hepatocelular/inmunología , Carcinoma Hepatocelular/tratamiento farmacológico , Neoplasias Hepáticas/inmunología , Neoplasias Hepáticas/terapia , Neoplasias Hepáticas/tratamiento farmacológico , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Inmunoterapia/métodos , Escape del Tumor/efectos de los fármacos
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