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1.
Nat Commun ; 15(1): 6768, 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39117652

RESUMO

Light is fundamental for biological life, with most mammals possessing light-sensing photoreceptors in various organs. Opsin3 is highly expressed in adipose tissue which has extensive communication with other organs, particularly with the brain through the sympathetic nervous system (SNS). Our study reveals a new light-triggered crosstalk between adipose tissue and the hypothalamus. Direct blue-light exposure to subcutaneous white fat improves high-fat diet-induced metabolic abnormalities in an Opsin3-dependent manner. Metabolomic analysis shows that blue light increases circulating levels of histidine, which activates histaminergic neurons in the hypothalamus and stimulates brown adipose tissue (BAT) via SNS. Blocking central actions of histidine and denervating peripheral BAT blunts the effects of blue light. Human white adipocytes respond to direct blue light stimulation in a cell-autonomous manner, highlighting the translational relevance of this pathway. Together, these data demonstrate a light-responsive metabolic circuit involving adipose-hypothalamus communication, offering a potential strategy to alleviate obesity-induced metabolic abnormalities.


Assuntos
Tecido Adiposo Marrom , Hipotálamo , Luz , Animais , Hipotálamo/metabolismo , Hipotálamo/efeitos da radiação , Humanos , Tecido Adiposo Marrom/metabolismo , Masculino , Camundongos , Obesidade/metabolismo , Camundongos Endogâmicos C57BL , Dieta Hiperlipídica/efeitos adversos , Opsinas de Bastonetes/metabolismo , Sistema Nervoso Simpático/metabolismo , Tecido Adiposo/metabolismo , Neurônios/metabolismo , Neurônios/efeitos da radiação , Tecido Adiposo Branco/metabolismo , Tecido Adiposo Branco/efeitos da radiação , Adipócitos Brancos/metabolismo , Adipócitos Brancos/efeitos da radiação
2.
Nat Commun ; 15(1): 7215, 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-39174539

RESUMO

Thermogenic adipose tissue, consisting of brown and beige fat, regulates nutrient utilization and energy metabolism. Human brown fat is relatively scarce and decreases with obesity and aging. Hence, inducing thermogenic differentiation of white fat offers an attractive way to enhance whole-body metabolic capacity. Here, we show the role of endothelin 3 (EDN3) and endothelin receptor type B (EDNRB) in promoting the browning of white adipose tissue (WAT). EDNRB overexpression stimulates thermogenic differentiation of human white preadipocytes through cAMP-EPAC1-ERK activation. In mice, cold induces the expression of EDN3 and EDNRB in WAT. Deletion of EDNRB in adipose progenitor cells impairs cold-induced beige adipocyte formation in WAT, leading to excessive weight gain, glucose intolerance, and insulin resistance upon high-fat feeding. Injection of EDN3 into WAT promotes browning and improved whole-body glucose metabolism. The findings shed light on the mechanism of WAT browning and offer potential therapeutics for obesity and metabolic disorders.


Assuntos
Tecido Adiposo Branco , Diferenciação Celular , Endotelina-3 , Receptor de Endotelina B , Transdução de Sinais , Termogênese , Animais , Tecido Adiposo Branco/metabolismo , Termogênese/genética , Humanos , Camundongos , Receptor de Endotelina B/metabolismo , Receptor de Endotelina B/genética , Endotelina-3/metabolismo , Endotelina-3/genética , Masculino , Obesidade/metabolismo , Obesidade/genética , Camundongos Endogâmicos C57BL , Dieta Hiperlipídica , Resistência à Insulina , Adipócitos Brancos/metabolismo , Camundongos Knockout , Adipócitos Bege/metabolismo , Tecido Adiposo Marrom/metabolismo , Intolerância à Glucose/metabolismo , Temperatura Baixa
3.
Am J Gastroenterol ; 2024 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-38994838
4.
Am J Gastroenterol ; 119(4): 779, 2024 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-38497558
5.
Comput Biol Med ; 171: 108218, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38428098

RESUMO

Pulmonary arterial hypertension (PAH) is a rapidly progressive and fatal disease, with right ventricular failure being the primary cause of death in patients with PAH. This study aims to determine the mechanical stimuli that may initiate heart growth and remodelling (G&R). To achieve this, two bi-ventricular models were constructed: one for a control rat heart and another for a rat heart with PAH. The growth of the diseased heart was estimated by warping it to the control heart using an improved large deformation diffeomorphic metric mapping (LDDMM) framework. Correlation analysis was then performed between mechanical cues (stress and strain) and growth tensors, which revealed that principal strains may serve as a triggering stimulus for myocardial growth and remodelling under PAH. The growth tensors, estimated from in vivo images, could explain 84.3% of the observed geometrical changes in the diseased heart with PAH by using a kinematic cardiac growth model. Our approach has the potential to quantify G&R using sparse in vivo images and to provide insights into the underlying mechanism of triggering right heart failure from a biomechanical perspective.


Assuntos
Hipertensão Pulmonar , Hipertensão Arterial Pulmonar , Humanos , Ratos , Animais , Fenômenos Biomecânicos , Coração , Ventrículos do Coração
6.
Am J Gastroenterol ; 119(4): 655-661, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37975609

RESUMO

INTRODUCTION: Whether 10-day short-course vonoprazan-amoxicillin dual therapy (VA-dual) is noninferior to the standard 14-day bismuth-based quadruple therapy (B-quadruple) against Helicobacter pylori eradication has not been determined. This trial aimed to compare the eradication rate, adverse events, and compliance of 10-day VA-dual regimen with standard 14-day B-quadruple regimen as first-line H. pylori treatment. METHODS: This prospective randomized clinical trial was performed at 3 institutions in eastern China. A total of 314 treatment-naive, H. pylori -infected patients were randomly assigned in a 1:1 ratio to either 10-day VA-dual group or 14-day B-quadruple group. Eradication success was determined by 13 C-urea breath test at least 4 weeks after treatment. Eradication rates, adverse events, and compliance were compared between groups. RESULTS: Eradication rates of VA-dual and B-quadruple groups were 86.0% and 89.2% ( P = 0.389), respectively, by intention-to-treat (ITT) analysis; 88.2% and 91.5% ( P = 0.338), respectively, by modified ITT analysis; and 90.8% and 91.3% ( P = 0.884), respectively, by per-protocol (PP) analysis. The efficacy of the VA-dual remained noninferior to B-quadruple therapy in all ITT, modified ITT, and PP analyses. The incidence of adverse events in the VA-dual group was significantly lower compared with that in the B-quadruple group ( P < 0.001). Poor compliance contributed to eradication failure in the VA-dual group ( P < 0.001), while not in the B-quadruple group ( P = 0.110). DISCUSSION: The 10-day VA-dual therapy provided satisfactory eradication rates of >90% (PP analysis) and lower rates of adverse events compared with standard 14-day B-quadruple therapy as first-line H. pylori therapy. TRAIL REGISTRATION NUMBER: ChiCTR2300070100.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Pirróis , Sulfonamidas , Humanos , Amoxicilina/uso terapêutico , Bismuto/uso terapêutico , Bismuto/efeitos adversos , Antibacterianos , Infecções por Helicobacter/tratamento farmacológico , Estudos Prospectivos , Quimioterapia Combinada , Adesão à Medicação , Resultado do Tratamento , Inibidores da Bomba de Prótons/efeitos adversos
8.
Yi Chuan ; 45(9): 845-855, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37731238

RESUMO

Gibberellin (GA) is an important hormone, which is involved in regulating various growth and development. GA biosynthesis pathway and synthetase have been basically clarified. Gibberellin 3ß hydroxylase (GA3ox) is the key enzyme for the synthesis of various active GA. There are two GA3ox genes (OsGA3ox1 and OsGA3ox2) in rice, and their physiological functions have been preliminarily studied. However, it is not clear how they work together to synthesize active GA to regulate rice development. In this study, the knockout mutants ga3ox1 and ga3ox2 were obtained by CRISPR/Cas9 technology. The pollen fertility of ga3ox1 decreased significantly, while the plant height of ga3ox2 decreased significantly. It shows that OsGA3ox1 is necessary for normal pollen development, while OsGA3ox2 is necessary for stem and leaf elongation. Tissue expression analysis showed that OsGA3ox1 was mainly expressed in unopened flowers, while OsGA3ox2 was mainly expressed in unexpanded leaves. The GA in different tissues of wild type (WT), and two ga3ox mutants were detected. It was found that pollen fertility is most closely related to the content of GA7, and plant height is most closely related to the content of GA1. It was found that OsGA3ox1 catalyzes GA9 to GA7 in flowers, which is closely related to pollen fertility; OsGA3ox2 catalyzes the GA20 to GA1 in unexpanded leaves, thereby regulating plant height; OsGA3ox1 catalyzes the GA19 to GA20 in roots, regulating the generation of GA3. OsGA3ox1 and OsGA3ox2 respond to developmental and environmental signals, and cooperate to synthesize endogenous GA in different tissues to regulate rice development. This study provides a reference for clarifying its role in GA biosynthesis pathway and further understanding the function of OsGA3ox.


Assuntos
Oryza , Oryza/genética , Giberelinas , Pólen , Fertilidade/genética , Flores/genética
9.
Front Physiol ; 13: 966454, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36388115

RESUMO

Aim: Pulmonary arterial hypertension (PAH) is an obstructive pulmonary vasculopathy that results in death from right ventricular failure (RVF). There is limited understanding of the molecular mechanisms of RVF in PAH. Methods: In a PAH-RVF model induced by injection of adult male rats with monocrotaline (MCT; 60 mg/kg), we performed mass spectrometry to identify proteins that change in the RV as a consequence of PAH induced RVF. Bioinformatic analysis was used to integrate our previously published RNA sequencing data from an independent cohort of PAH rats. Results: We identified 1,277 differentially regulated proteins in the RV of MCT rats compared to controls. Integration of MCT RV transcriptome and proteome data sets identified 410 targets that are concordantly regulated at the mRNA and protein levels. Functional analysis of these data revealed enriched functions, including mitochondrial metabolism, cellular respiration, and purine metabolism. We also prioritized 15 highly enriched protein:transcript pairs and confirmed their biological plausibility as contributors to RVF. We demonstrated an overlap of these differentially expressed pairs with data published by independent investigators using multiple PAH models, including the male SU5416-hypoxia model and several male rat strains. Conclusion: Multiomic integration provides a novel view of the molecular phenotype of RVF in PAH which includes dysregulation of pathways involving purine metabolism, mitochondrial function, inflammation, and fibrosis.

10.
Nat Metab ; 4(6): 775-790, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35760872

RESUMO

Obesity induces chronic inflammation resulting in insulin resistance and metabolic disorders. Cold exposure can improve insulin sensitivity in humans and rodents, but the mechanisms have not been fully elucidated. Here, we find that cold resolves obesity-induced inflammation and insulin resistance and improves glucose tolerance in diet-induced obese mice. The beneficial effects of cold exposure on improving obesity-induced inflammation and insulin resistance depend on brown adipose tissue (BAT) and liver. Using targeted liquid chromatography with tandem mass spectrometry, we discovered that cold and ß3-adrenergic stimulation promote BAT to produce maresin 2 (MaR2), a member of the specialized pro-resolving mediators of bioactive lipids that play a role in the resolution of inflammation. Notably, MaR2 reduces inflammation in obesity in part by targeting macrophages in the liver. Thus, BAT-derived MaR2 could contribute to the beneficial effects of BAT activation in resolving obesity-induced inflammation and may inform therapeutic approaches to combat obesity and its complications.


Assuntos
Tecido Adiposo Marrom , Resistência à Insulina , Tecido Adiposo Marrom/metabolismo , Animais , Ácidos Docosa-Hexaenoicos , Inflamação/metabolismo , Camundongos , Obesidade/metabolismo
11.
Am J Respir Crit Care Med ; 206(5): 608-624, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35699679

RESUMO

Rationale: Pulmonary arterial hypertension (PAH) often results in death from right ventricular failure (RVF). NLRP3 (nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3)-macrophage activation may promote RVF in PAH. Objectives: Evaluating the contribution of the NLRP3 inflammasome in RV macrophages to PAH RVF. Methods: Rats with decompensated RV hypertrophy (monocrotaline [MCT] and Sugen-5416 hypoxia [SuHx]) were compared with compensated RV hypertrophy rats (pulmonary artery banding). Echocardiography and right heart catheterization were performed. Macrophages, atrial natriuretic peptides, and fibrosis were evaluated by microscopy or flow cytometry. NLRP3 inflammasome activation and cardiotoxicity were confirmed by immunoblot and in vitro strategies. MCT rats were treated with SC-144 (a GP130 antagonist) or MCC950 (an NLRP3 inhibitor). Macrophage-NLRP3 activity was evaluated in patients with PAH RVF. Measurements and Main Results: Macrophages, fibrosis, and atrial natriuretic peptides were increased in MCT and SuHx RVs but not in left ventricles or pulmonary artery banding rats. Although MCT RV macrophages were inflammatory, lung macrophages were antiinflammatory. CCR2+ macrophages (monocyte-derived) were increased in MCT and SuHx RVs and highly expressed NLRP3. The macrophage-NLRP3 pathway was upregulated in patients with PAH with decompensated RVs. Cultured MCT monocytes showed NLRP3 activation, and in coculture experiments resulted in cardiomyocyte mitochondrial damage, which MCC950 prevented. In vivo, MCC950 reduced NLRP3 activation and regressed pulmonary vascular disease and RVF. SC-144 reduced RV macrophages and NLRP3 content, prevented STAT3 (signal transducer and activator of transcription 3) activation, and improved RV function without regressing pulmonary vascular disease. Conclusions: NLRP3-macrophage activation occurs in the decompensated RV in preclinical PAH models and patients with PAH. Inhibiting GP130 or NLRP3 signaling improves RV function. The concept that PAH RVF results from RV inflammation rather than solely from elevated RV afterload suggests a new therapeutic paradigm.


Assuntos
Insuficiência Cardíaca , Hipertensão Pulmonar , Hipertensão Arterial Pulmonar , Disfunção Ventricular Direita , Animais , Fator Natriurético Atrial , Receptor gp130 de Citocina , Modelos Animais de Doenças , Hipertensão Pulmonar Primária Familiar , Fibrose , Ventrículos do Coração , Hipertrofia Ventricular Direita/etiologia , Inflamassomos , Ativação de Macrófagos , Macrófagos/metabolismo , Monocrotalina , Proteína 3 que Contém Domínio de Pirina da Família NLR , Hipertensão Arterial Pulmonar/etiologia , Ratos
12.
Sci Adv ; 8(13): eabm4491, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35363529

RESUMO

In the retina, signals originating from rod and cone photoreceptors can reach retinal ganglion cells (RGCs)-the output neurons-through different pathways. However, little is known about the exact sensitivities and operating ranges of these pathways. Previously, we created rod- or cone-specific Cx36 knockout (KO) mouse lines. Both lines are deficient in rod/cone electrical coupling and therefore provide a way to selectively remove the secondary rod pathway. We measured the threshold of the primary rod pathway in RGCs of wild-type mice. Under pharmacological blockade of the primary rod pathway, the threshold was elevated. This secondary component was removed in the Cx36 KOs to unmask the threshold of the third rod pathway, still below cone threshold. In turn, the cone threshold was estimated by several independent methods. Our work defines the functionality of the secondary rod pathway and describes an additive contribution of the different pathways to the retinal output.

13.
Acta Physiol (Oxf) ; 234(2): e13764, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34978755

RESUMO

INTRODUCTION: Group 2 pulmonary hypertension (PH) has no approved PH-targeted therapy. Metabolic remodelling, specifically a biventricular increase in pyruvate kinase muscle (PKM) isozyme 2 to 1 ratio, occurs in rats with group 2 PH induced by supra-coronary aortic banding (SAB). We hypothesize that increased PKM2/PKM1 is maladaptive and inhibiting PKM2 would improve right ventricular (RV) function. METHODS: Male, Sprague-Dawley SAB rats were confirmed to have PH by echocardiography and then randomized to treatment with a PKM2 inhibitor (intraperitoneal shikonin, 2 mg/kg/day) versus 5% DMSO (n = 5/group) or small interfering RNA-targeting PKM2 (siPKM2) versus siRNA controls (n = 7/group) by airway nebulization. RESULTS: Shikonin-treated SAB rats had milder PH (PAAT 32.1 ± 1.3 vs 22.1 ± 1.2 ms, P = .0009) and lower RV systolic pressure (RVSP) (31.5 ± 0.9 vs 55.7 ± 1.9 mm Hg, P < .0001) versus DMSO-SAB rats. siPKM2 nebulization reduced PKM2 expression in the RV, increased PAAT (31.7 ± 0.7 vs 28.0 ± 1.3 ms, P = .025), lowered RVSP (30.6 ± 2.6 vs 42.0 ± 4.0 mm Hg, P = .032) and reduced diastolic RVFW thickness (0.69 ± 0.04 vs 0.85 ± 0.06 mm, P = .046). Both shikonin and siPKM2 regressed PH-induced medial hypertrophy of small pulmonary arteries. CONCLUSION: Increases in PKM2/PKM1 in the RV contribute to RV dysfunction in group 2 PH. Chemical or molecular inhibition of PKM2 restores the normal PKM2/PKM1 ratio, reduces PH, RVSP and RVH and regresses adverse PA remodelling. PKM2 merits consideration as a therapeutic cardiac target for group 2 PH.


Assuntos
Hipertensão Pulmonar , Animais , Hipertensão Pulmonar/metabolismo , Masculino , Músculos/metabolismo , Isoformas de Proteínas , Piruvato Quinase/genética , Piruvato Quinase/metabolismo , Piruvato Quinase/uso terapêutico , Ratos , Ratos Sprague-Dawley
14.
Nat Commun ; 13(1): 500, 2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-35079023

RESUMO

Thin-film composite membranes formed by conventional interfacial polymerization generally suffer from the depth heterogeneity of the polyamide layer, i.e., nonuniformly distributed free volume pores, leading to the inefficient permselectivity. Here, we demonstrate a facile and versatile approach to tune the nanoscale homogeneity of polyamide-based thin-film composite membranes via inorganic salt-mediated interfacial polymerization process. Molecular dynamics simulations and various characterization techniques elucidate in detail the underlying molecular mechanism by which the salt addition confines and regulates the diffusion of amine monomers to the water-oil interface and thus tunes the nanoscale homogeneity of the polyamide layer. The resulting thin-film composite membranes with thin, smooth, dense, and structurally homogeneous polyamide layers demonstrate a permeance increment of ~20-435% and/or solute rejection enhancement of ~10-170% as well as improved antifouling property for efficient reverse/forward osmosis and nanofiltration separations. This work sheds light on the tunability of the polyamide layer homogeneity via salt-regulated interfacial polymerization process.

15.
FASEB J ; 35(8): e21771, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34275172

RESUMO

Impaired mitochondrial fusion, due in part to decreased mitofusin 2 (Mfn2) expression, contributes to unrestricted cell proliferation and apoptosis-resistance in hyperproliferative diseases like pulmonary arterial hypertension (PAH) and non-small cell lung cancer (NSCLC). We hypothesized that Mfn2 levels are reduced due to increased proteasomal degradation of Mfn2 triggered by its phosphorylation at serine 442 (S442) and investigated the potential kinase mediators. Mfn2 expression was decreased and Mfn2 S442 phosphorylation was increased in pulmonary artery smooth muscle cells from PAH patients and in NSCLC cells. Mfn2 phosphorylation was mediated by PINK1 and protein kinase A (PKA), although only PINK1 expression was increased in these diseases. We designed a S442 phosphorylation deficient Mfn2 construct (PD-Mfn2) and a S442 constitutively phosphorylated Mfn2 construct (CP-Mfn2). The effects of these modified Mfn2 constructs on Mfn2 expression and biological function were compared with those of the wildtype Mfn2 construct (WT-Mfn2). WT-Mfn2 increased Mfn2 expression and mitochondrial fusion in both PAH and NSCLC cells resulting in increased apoptosis and decreased cell proliferation. Compared to WT-Mfn2, PD-Mfn2 caused greater Mfn2 expression, suppression of proliferation, apoptosis induction, and cell cycle arrest. Conversely, CP-Mfn2 caused only a small increase in Mfn2 expression and did not restore mitochondrial fusion, inhibit cell proliferation, or induce apoptosis. Silencing PINK1 or PKA, or proteasome blockade using MG132, increased Mfn2 expression, enhanced mitochondrial fusion and induced apoptosis. In a xenotransplantation NSCLC model, PD-Mfn2 gene therapy caused greater tumor regression than did therapy with WT-Mfn2. Mfn2 deficiency in PAH and NSCLC reflects proteasomal degradation triggered by Mfn2-S442 phosphorylation by PINK1 and/or PKA. Inhibiting Mfn2 phosphorylation has potential therapeutic benefit in PAH and lung cancer.


Assuntos
Proliferação de Células , GTP Fosfo-Hidrolases/metabolismo , Hipertensão Pulmonar/metabolismo , Neoplasias Pulmonares/metabolismo , Proteínas Mitocondriais/metabolismo , Proteínas de Neoplasias/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Quinases/metabolismo , Proteólise , Células A549 , Animais , GTP Fosfo-Hidrolases/genética , Humanos , Hipertensão Pulmonar/genética , Neoplasias Pulmonares/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Proteínas Mitocondriais/genética , Proteínas de Neoplasias/genética , Fosforilação/genética , Complexo de Endopeptidases do Proteassoma/genética , Proteínas Quinases/genética
16.
Nat Metab ; 3(4): 485-495, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33846638

RESUMO

Brown adipose tissue (BAT) and beige fat function in energy expenditure in part due to their role in thermoregulation, making these tissues attractive targets for treating obesity and metabolic disorders. While prolonged cold exposure promotes de novo recruitment of brown adipocytes, the exact sources of cold-induced thermogenic adipocytes are not completely understood. Here, we identify transient receptor potential cation channel subfamily V member 1 (Trpv1)+ vascular smooth muscle (VSM) cells as previously unidentified thermogenic adipocyte progenitors. Single-cell RNA sequencing analysis of interscapular brown adipose depots reveals, in addition to the previously known platelet-derived growth factor receptor (Pdgfr)α-expressing mesenchymal progenitors, a population of VSM-derived adipocyte progenitor cells (VSM-APC) expressing the temperature-sensitive cation channel Trpv1. We demonstrate that cold exposure induces the proliferation of Trpv1+ VSM-APCs and enahnces their differentiation to highly thermogenic adipocytes. Together, these findings illustrate the landscape of the thermogenic adipose niche at single-cell resolution and identify a new cellular origin for the development of brown and beige adipocytes.


Assuntos
Adipócitos/fisiologia , Temperatura Baixa , Células-Tronco Hematopoéticas/fisiologia , Músculo Liso Vascular/fisiologia , Canais de Cátion TRPV/fisiologia , Termogênese/fisiologia , Adipócitos Bege/fisiologia , Adipócitos Marrons/fisiologia , Tecido Adiposo Bege/metabolismo , Tecido Adiposo Marrom/fisiologia , Animais , Regulação da Temperatura Corporal/fisiologia , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Humanos , Células-Tronco Mesenquimais , Camundongos , Camundongos Endogâmicos C57BL , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Canais de Cátion TRPV/genética
17.
Free Radic Biol Med ; 170: 150-178, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33450375

RESUMO

The homeostatic oxygen sensing system (HOSS) optimizes systemic oxygen delivery. Specialized tissues utilize a conserved mitochondrial sensor, often involving NDUFS2 in complex I of the mitochondrial electron transport chain, as a site of pO2-responsive production of reactive oxygen species (ROS). These ROS are converted to a diffusible signaling molecule, hydrogen peroxide (H2O2), by superoxide dismutase (SOD2). H2O2 exits the mitochondria and regulates ion channels and enzymes, altering plasma membrane potential, intracellular Ca2+ and Ca2+-sensitization and controlling acute, adaptive, responses to hypoxia that involve changes in ventilation, vascular tone and neurotransmitter release. Subversion of this O2-sensing pathway creates a pseudohypoxic state that promotes disease progression in pulmonary arterial hypertension (PAH) and cancer. Pseudohypoxia is a state in which biochemical changes, normally associated with hypoxia, occur despite normal pO2. Epigenetic silencing of SOD2 by DNA methylation alters H2O2 production, activating hypoxia-inducible factor 1α, thereby disrupting mitochondrial metabolism and dynamics, accelerating cell proliferation and inhibiting apoptosis. Other epigenetic mechanisms, including dysregulation of microRNAs (miR), increase pyruvate dehydrogenase kinase and pyruvate kinase muscle isoform 2 expression in both diseases, favoring uncoupled aerobic glycolysis. This Warburg metabolic shift also accelerates cell proliferation and impairs apoptosis. Disordered mitochondrial dynamics, usually increased mitotic fission and impaired fusion, promotes disease progression in PAH and cancer. Epigenetic upregulation of dynamin-related protein 1 (Drp1) and its binding partners, MiD49 and MiD51, contributes to the pathogenesis of PAH and cancer. Finally, dysregulation of intramitochondrial Ca2+, resulting from impaired mitochondrial calcium uniporter complex (MCUC) function, links abnormal mitochondrial metabolism and dynamics. MiR-mediated decreases in MCUC function reduce intramitochondrial Ca2+, promoting Warburg metabolism, whilst increasing cytosolic Ca2+, promoting fission. Epigenetically disordered mitochondrial O2-sensing, metabolism, dynamics, and Ca2+ homeostasis offer new therapeutic targets for PAH and cancer. Promoting glucose oxidation, restoring the fission/fusion balance, and restoring mitochondrial calcium regulation are promising experimental therapeutic strategies.


Assuntos
Hipertensão Pulmonar , Neoplasias , Biologia , Humanos , Peróxido de Hidrogênio , Hipertensão Pulmonar/genética , Neoplasias/genética , Neoplasias/terapia , Oxigênio
18.
Int J Mol Sci ; 21(19)2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33019763

RESUMO

The hexosamine biosynthetic pathway (HBP) converts glucose to uridine-diphosphate-N-acetylglucosamine, which, when added to serines or threonines, modulates protein function through protein O-GlcNAcylation. Glutamine-fructose-6-phosphate amidotransferase (GFAT) regulates HBP flux, and AMP-kinase phosphorylation of GFAT blunts GFAT activity and O-GlcNAcylation. While numerous studies demonstrate increased right ventricle (RV) glucose uptake in pulmonary arterial hypertension (PAH), the relationship between O-GlcNAcylation and RV function in PAH is unexplored. Therefore, we examined how colchicine-mediated AMP-kinase activation altered HBP intermediates, O-GlcNAcylation, mitochondrial function, and RV function in pulmonary artery-banded (PAB) and monocrotaline (MCT) rats. AMPK activation induced GFAT phosphorylation and reduced HBP intermediates and O-GlcNAcylation in MCT but not PAB rats. Reduced O-GlcNAcylation partially restored the RV metabolic signature and improved RV function in MCT rats. Proteomics revealed elevated expression of O-GlcNAcylated mitochondrial proteins in MCT RVs, which fractionation studies corroborated. Seahorse micropolarimetry analysis of H9c2 cardiomyocytes demonstrated colchicine improved mitochondrial function and reduced O-GlcNAcylation. Presence of diabetes in PAH, a condition of excess O-GlcNAcylation, reduced RV contractility when compared to nondiabetics. Furthermore, there was an inverse relationship between RV contractility and HgbA1C. Finally, RV biopsy specimens from PAH patients displayed increased O-GlcNAcylation. Thus, excess O-GlcNAcylation may contribute to metabolic derangements and RV dysfunction in PAH.


Assuntos
Diabetes Mellitus/metabolismo , Hipertrofia Ventricular Direita/metabolismo , Mitocôndrias/metabolismo , Processamento de Proteína Pós-Traducional , Disfunção Ventricular Direita/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Acilação , Adulto , Idoso , Animais , Linhagem Celular , Estudos de Coortes , Colchicina/farmacologia , Diabetes Mellitus/diagnóstico por imagem , Diabetes Mellitus/genética , Diabetes Mellitus/fisiopatologia , Modelos Animais de Doenças , Ecocardiografia , Regulação da Expressão Gênica , Glutamina-Frutose-6-Fosfato Transaminase (Isomerizante)/genética , Glutamina-Frutose-6-Fosfato Transaminase (Isomerizante)/metabolismo , Hexosaminas/metabolismo , Humanos , Hipertrofia Ventricular Direita/diagnóstico por imagem , Hipertrofia Ventricular Direita/genética , Hipertrofia Ventricular Direita/fisiopatologia , Masculino , Metaboloma , Pessoa de Meia-Idade , Mitocôndrias/efeitos dos fármacos , Monocrotalina/administração & dosagem , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Ratos , Ratos Sprague-Dawley , Disfunção Ventricular Direita/diagnóstico por imagem , Disfunção Ventricular Direita/genética , Disfunção Ventricular Direita/fisiopatologia
19.
World J Gastroenterol ; 26(32): 4846-4856, 2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32921961

RESUMO

BACKGROUND: The Helicobacter pylori (H. pylori) eradication rate is decreasing in the general population of China. AIM: To evaluate the H. pylori eradication status in real-world clinical practice and to explore factors related to eradication failure. METHODS: Patients with H. pylori infection who were treated with standard 14-d quadruple therapy and received a test of cure at a provincial medical institution between June 2018 and May 2019 were enrolled. Demographic and clinical data were recorded. Eradication rates were calculated and compared between regimens and subgroups. Multivariate analysis was performed to identify predictors of eradication failure. RESULTS: Of 2610 patients enrolled, eradication was successful in 1999 (76.6%) patients. Amoxicillin-containing quadruple regimens showed a higher eradication rate than other quadruple therapy regimens (83.0% vs 69.0%, P < 0.001). The quadruple therapy containing amoxicillin plus clarithromycin achieved the highest eradication rate (83.5%). Primary therapy had a higher eradication rate than rescue therapy (78.3% vs 66.5%, P < 0.001). In rescue therapy, the amoxicillin- and furazolidone-containing regimens achieved the highest eradication rate (80.8%). Esomeprazole-containing regimens showed a higher eradication rate than those containing other proton pump inhibitors (81.8% vs 74.9%, P = 0.001). Multivariate regression analysis found that older age, prior therapy, and use of omeprazole or pantoprazole were associated with an increased risk of eradication failure. CONCLUSION: The total eradication rate is 76.6%. Amoxicillin-containing regimens are superior to other regimens. Age, prior therapy, and use of omeprazole or pantoprazole are independent risk factors for eradication failure.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Idoso , Amoxicilina/uso terapêutico , Antibacterianos/efeitos adversos , China/epidemiologia , Claritromicina/uso terapêutico , Quimioterapia Combinada , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/epidemiologia , Humanos , Inibidores da Bomba de Prótons/uso terapêutico , Fatores de Risco
20.
Sci Transl Med ; 12(558)2020 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-32848096

RESUMO

Brown and brown-like beige/brite adipocytes dissipate energy and have been proposed as therapeutic targets to combat metabolic disorders. However, the therapeutic effects of cell-based therapy in humans remain unclear. Here, we created human brown-like (HUMBLE) cells by engineering human white preadipocytes using CRISPR-Cas9-SAM-gRNA to activate endogenous uncoupling protein 1 expression. Obese mice that received HUMBLE cell transplants showed a sustained improvement in glucose tolerance and insulin sensitivity, as well as increased energy expenditure. Mechanistically, increased arginine/nitric oxide (NO) metabolism in HUMBLE adipocytes promoted the production of NO that was carried by S-nitrosothiols and nitrite in red blood cells to activate endogenous brown fat and improved glucose homeostasis in recipient animals. Together, these data demonstrate the utility of using CRISPR-Cas9 technology to engineer human white adipocytes to display brown fat-like phenotypes and may open up cell-based therapeutic opportunities to combat obesity and diabetes.


Assuntos
Adipócitos Marrons , Síndrome Metabólica , Tecido Adiposo Marrom/metabolismo , Animais , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Dieta Hiperlipídica , Metabolismo Energético , Humanos , Síndrome Metabólica/terapia , Camundongos , Camundongos Obesos , Obesidade/metabolismo , Obesidade/terapia , Termogênese
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