Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.543
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
N Engl J Med ; 388(14): 1259-1271, 2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-36762865

RESUMO

BACKGROUND: Trials of the efficacy and safety of endovascular thrombectomy in patients with large ischemic strokes have been carried out in limited populations. METHODS: We performed a prospective, randomized, open-label, adaptive, international trial involving patients with stroke due to occlusion of the internal carotid artery or the first segment of the middle cerebral artery to assess endovascular thrombectomy within 24 hours after onset. Patients had a large ischemic-core volume, defined as an Alberta Stroke Program Early Computed Tomography Score of 3 to 5 (range, 0 to 10, with lower scores indicating larger infarction) or a core volume of at least 50 ml on computed tomography perfusion or diffusion-weighted magnetic resonance imaging. Patients were assigned in a 1:1 ratio to endovascular thrombectomy plus medical care or to medical care alone. The primary outcome was the modified Rankin scale score at 90 days (range, 0 to 6, with higher scores indicating greater disability). Functional independence was a secondary outcome. RESULTS: The trial was stopped early for efficacy; 178 patients had been assigned to the thrombectomy group and 174 to the medical-care group. The generalized odds ratio for a shift in the distribution of modified Rankin scale scores toward better outcomes in favor of thrombectomy was 1.51 (95% confidence interval [CI], 1.20 to 1.89; P<0.001). A total of 20% of the patients in the thrombectomy group and 7% in the medical-care group had functional independence (relative risk, 2.97; 95% CI, 1.60 to 5.51). Mortality was similar in the two groups. In the thrombectomy group, arterial access-site complications occurred in 5 patients, dissection in 10, cerebral-vessel perforation in 7, and transient vasospasm in 11. Symptomatic intracranial hemorrhage occurred in 1 patient in the thrombectomy group and in 2 in the medical-care group. CONCLUSIONS: Among patients with large ischemic strokes, endovascular thrombectomy resulted in better functional outcomes than medical care but was associated with vascular complications. Cerebral hemorrhages were infrequent in both groups. (Funded by Stryker Neurovascular; SELECT2 ClinicalTrials.gov number, NCT03876457.).


Assuntos
Isquemia Encefálica , Procedimentos Endovasculares , AVC Isquêmico , Trombectomia , Humanos , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/cirurgia , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/métodos , Fibrinolíticos/efeitos adversos , Fibrinolíticos/uso terapêutico , AVC Isquêmico/diagnóstico por imagem , AVC Isquêmico/tratamento farmacológico , AVC Isquêmico/cirurgia , Estudos Prospectivos , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/cirurgia , Trombectomia/efeitos adversos , Trombectomia/métodos , Resultado do Tratamento , Infarto da Artéria Cerebral Média/complicações , Doenças das Artérias Carótidas/complicações , Recuperação de Função Fisiológica , Hemorragia Cerebral/induzido quimicamente , Hemorragia Cerebral/etiologia
2.
J Biol Chem ; 300(3): 105726, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38325741

RESUMO

Hyperlipidemia predisposes individuals to cardiometabolic diseases, the most common cause of global mortality. Microsomal triglyceride transfer protein (MTP) transfers multiple lipids and is essential for the assembly of apolipoprotein B-containing lipoproteins. MTP inhibition lowers plasma lipids but causes lipid retention in the liver and intestine. Previous studies suggested two lipid transfer domains in MTP and that specific inhibition of triglyceride (TG) and not phospholipid (PL) transfer can lower plasma lipids without significant tissue lipid accumulation. However, how MTP transfers different lipids and the domains involved in these activities are unknown. Here, we tested a hypothesis that two different ß-sandwich domains in MTP transfer TG and PL. Mutagenesis of charged amino acids in ß2-sandwich had no effect on PL transfer activity indicating that they are not critical. In contrast, amino acids with bulky hydrophobic side chains in ß1-sandwich were critical for both TG and PL transfer activities. Substitutions of these residues with smaller hydrophobic side chains or positive charges reduced, whereas negatively charged side chains severely attenuated MTP lipid transfer activities. These studies point to a common lipid transfer domain for TG and PL in MTP that is enriched with bulky hydrophobic amino acids. Furthermore, we observed a strong correlation in different MTP mutants with respect to loss of both the lipid transfer activities, again implicating a common binding site for TG and PL in MTP. We propose that targeting of areas other than the identified common lipid transfer domain might reduce plasma lipids without causing cellular lipid retention.


Assuntos
Proteínas de Transporte , Interações Hidrofóbicas e Hidrofílicas , Fosfolipídeos , Triglicerídeos , Humanos , Aminoácidos/química , Aminoácidos/genética , Aminoácidos/metabolismo , Apolipoproteínas B/química , Apolipoproteínas B/metabolismo , Proteínas de Transporte/química , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Fosfolipídeos/sangue , Fosfolipídeos/metabolismo , Triglicerídeos/sangue , Triglicerídeos/metabolismo , Domínios Proteicos , Mutação , Relação Estrutura-Atividade , Sítios de Ligação
3.
Ann Neurol ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38922985

RESUMO

OBJECTIVES: The benefits of intravenous thrombolysis are time-dependent, with maximum efficacy when administered within the first "golden" hour after onset. Nevertheless, the impact of golden hour thrombolysis has not been well quantified. METHODS: Medline, Embase, and Web of Science databases were systematically searched from inception to August 27, 2023. We included studies that reported safety and efficacy outcomes of ischemic stroke patients treated with intravenous thrombolysis in the golden hour versus later treatment window. The primary outcome was an excellent functional outcome, defined as a modified Rankin Scale score of 0-1 at 90 days. The secondary efficacy outcome was a good functional outcome (defined as modified Rankin Scale score of 0-2). The main safety outcome was symptomatic intracerebral hemorrhage. RESULTS: Seven studies involving 78,826 patients met the selection criteria. Golden hour thrombolysis was associated with higher odds of 90-day excellent functional outcomes (OR 1.40, 95% CI 1.16-1.67) and 90-day good functional outcomes (OR 1.38, 95% CI 1.13-1.69) compared with thrombolysis outside the golden hour. The number needed to treat to benefit for golden hour thrombolysis to reduce disability by at least 1 level on the modified Rankin Scale per patient was 2.6. Rates of symptomatic intracerebral hemorrhage and mortality were similar between groups. INTERPRETATION: Golden hour thrombolysis significantly improved acute ischemic stroke outcomes. The findings provide rationale for intensive efforts aimed at expediting thrombolytic therapy within the golden hour window following the onset of acute ischemic stroke. ANN NEUROL 2024.

4.
FASEB J ; 38(5): e23522, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38445789

RESUMO

Lipid processing by the retinal pigment epithelium (RPE) is necessary to maintain retinal health and function. Dysregulation of retinal lipid homeostasis due to normal aging or age-related disease triggers lipid accumulation within the RPE, on Bruch's membrane (BrM), and in the subretinal space. In its role as a hub for lipid trafficking into and out of the neural retina, the RPE packages a significant amount of lipid into lipid droplets for storage and into apolipoprotein B (APOB)-containing lipoproteins (Blps) for export. Microsomal triglyceride transfer protein (MTP), encoded by the MTTP gene, is essential for Blp assembly. Herein we test the hypothesis that MTP expression in the RPE is essential to maintain lipid balance and retinal function using the newly generated RPEΔMttp mouse model. Using non-invasive ocular imaging, electroretinography, and histochemical and biochemical analyses we show that genetic depletion of Mttp from the RPE results in intracellular lipid accumulation, increased photoreceptor-associated cholesterol deposits, and photoreceptor cell death, and loss of rod but not cone function. RPE-specific reduction in Mttp had no significant effect on plasma lipids and lipoproteins. While APOB was decreased in the RPE, most ocular retinoids remained unchanged, with the exception of the storage form of retinoid, retinyl ester. Thus suggesting that RPE MTP is critical for Blp synthesis and assembly but is not directly involved in plasma lipoprotein metabolism. These studies demonstrate that RPE-specific MTP expression is necessary to establish and maintain retinal lipid homeostasis and visual function.


Assuntos
Proteínas de Transporte , Retina , Epitélio Pigmentado da Retina , Animais , Camundongos , Retinoides , Apolipoproteínas B/genética , Homeostase
5.
Hepatology ; 78(5): 1418-1432, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36053190

RESUMO

BACKGROUND AND AIMS: The assembly and secretion of VLDL from the liver, a pathway that affects hepatic and plasma lipids, remains incompletely understood. We set out to identify players in the VLDL biogenesis pathway by identifying genes that are co-expressed with the MTTP gene that encodes for microsomal triglyceride transfer protein, key to the lipidation of apolipoprotein B, the core protein of VLDL. Using human and murine transcriptomic data sets, we identified small leucine-rich protein 1 ( SMLR1 ), encoding for small leucine-rich protein 1, a protein of unknown function that is exclusively expressed in liver and small intestine. APPROACH AND RESULTS: To assess the role of SMLR1 in the liver, we used somatic CRISPR/CRISPR-associated protein 9 gene editing to silence murine Smlr1 in hepatocytes ( Smlr1 -LKO). When fed a chow diet, male and female mice show hepatic steatosis, reduced plasma apolipoprotein B and triglycerides, and reduced VLDL secretion without affecting microsomal triglyceride transfer protein activity. Immunofluorescence studies show that SMLR1 is in the endoplasmic reticulum and Cis-Golgi complex. The loss of hepatic SMLR1 in female mice protects against diet-induced hyperlipidemia and atherosclerosis but causes NASH. On a high-fat, high-cholesterol diet, insulin and glucose tolerance tests did not reveal differences in male Smlr1 -LKO mice versus controls. CONCLUSIONS: We propose a role for SMLR1 in the trafficking of VLDL from the endoplasmic reticulum to the Cis-Golgi complex. While this study uncovers SMLR1 as a player in the VLDL assembly, trafficking, and secretion pathway, it also shows that NASH can occur with undisturbed glucose homeostasis and atheroprotection.


Assuntos
Aterosclerose , Lipoproteínas VLDL , Hepatopatia Gordurosa não Alcoólica , Proteoglicanos Pequenos Ricos em Leucina , Animais , Feminino , Humanos , Masculino , Camundongos , Apolipoproteínas B/sangue , Aterosclerose/sangue , Aterosclerose/genética , Aterosclerose/metabolismo , Aterosclerose/prevenção & controle , Leucina , Lipoproteínas VLDL/biossíntese , Lipoproteínas VLDL/sangue , Lipoproteínas VLDL/metabolismo , Fígado/metabolismo , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo , Proteoglicanos Pequenos Ricos em Leucina/genética , Proteoglicanos Pequenos Ricos em Leucina/metabolismo , Triglicerídeos/sangue
6.
Ann Neurol ; 93(4): 793-804, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36571388

RESUMO

OBJECTIVE: Reperfusion therapy is highly beneficial for ischemic stroke. Reduction in both infarct growth and edema are plausible mediators of clinical benefit with reperfusion. We aimed to quantify these mediators and their interrelationship. METHODS: In a pooled, patient-level analysis of the EXTEND-IA trials and SELECT study, we used a mediation analysis framework to quantify infarct growth and cerebral edema (midline shift) mediation effect on successful reperfusion (modified Treatment in Cerebral Ischemia ≥ 2b) association with functional outcome (modified Rankin Scale distribution). Furthermore, we evaluated an additional pathway to the original hypothesis, where infarct growth mediated successful reperfusion effect on midline shift. RESULTS: A total 542 of 665 (81.5%) eligible patients achieved successful reperfusion. Baseline clinical and imaging characteristics were largely similar between those achieving successful versus unsuccessful reperfusion. Median infarct growth was 12.3ml (interquartile range [IQR] = 1.8-48.4), and median midline shift was 0mm (IQR = 0-2.2). Of 249 (37%) demonstrating a midline shift of ≥1mm, median shift was 2.75mm (IQR = 1.89-4.21). Successful reperfusion was associated with reductions in both predefined mediators, infarct growth (ß = -1.19, 95% confidence interval [CI] = -1.51 to -0.88, p < 0.001) and midline shift (adjusted odds ratio = 0.36, 95% CI = 0.23-0.57, p < 0.001). Successful reperfusion association with improved functional outcome (adjusted common odds ratio [acOR] = 2.68, 95% CI = 1.86-3.88, p < 0.001) became insignificant (acOR = 1.39, 95% CI = 0.95-2.04, p = 0.094) when infarct growth and midline shift were added to the regression model. Infarct growth and midline shift explained 45% and 34% of successful reperfusion effect, respectively. Analysis considering an alternative hypothesis demonstrated consistent results. INTERPRETATION: In this mediation analysis from a pooled, patient-level cohort, a significant proportion (~80%) of successful reperfusion effect on functional outcome was mediated through reduction in infarct growth and cerebral edema. Further studies are required to confirm our findings, detect additional mediators to explain successful reperfusion residual effect, and identify novel therapeutic targets to further enhance reperfusion benefits. ANN NEUROL 2023;93:793-804.


Assuntos
Edema Encefálico , Isquemia Encefálica , Procedimentos Endovasculares , Acidente Vascular Cerebral , Humanos , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/terapia , Acidente Vascular Cerebral/complicações , Edema Encefálico/etiologia , Edema Encefálico/complicações , Resultado do Tratamento , Estudos Prospectivos , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/terapia , Isquemia Encefálica/complicações , Infarto Cerebral/diagnóstico por imagem , Infarto Cerebral/terapia , Infarto Cerebral/complicações , Reperfusão/métodos , Procedimentos Endovasculares/métodos
7.
J Biol Chem ; 298(4): 101813, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35278429

RESUMO

High plasma lipid levels have been demonstrated to increase cardiovascular disease risk. Despite advances in treatments to decrease plasma lipids, additional therapeutics are still needed because many people are intolerant or nonresponsive to these therapies. We previously showed that increasing cellular levels of microRNA-30c (miR-30c) using viral vectors or liposomes reduces plasma lipids and atherosclerosis. In this study, we aimed to synthesize potent miR-30c analogs that can be delivered to hepatoma cells without the aid of viral vectors and lipid emulsions. We hypothesized that modification of the passenger strand of miR-30c would increase the stability of miR-30c and augment its delivery to liver cells. Here, we report the successful synthesis of a series of miR-30c analogs by using different chemically modified nucleosides. In these analogs, we left the active sense strand untouched so that its biological activity remained unaltered, and we modified the passenger strand of miR-30c to enhance the stability and uptake of miR-30c by hepatoma cells through phosphorothiorate linkages and the addition of GalNAc. We show that these analogs significantly reduced apolipoprotein B secretion in Huh-7 human hepatoma cells and human primary hepatocytes without affecting apolipoprotein A1 secretion and cellular lipid levels. Our results provide a proof of concept that the passenger strand of miR-30c can be modified to increase its stability and delivery to cells while retaining the potency of the sense strand. We anticipate these miR-30c analogs will be useful in the development of more efficacious analogs for the treatment of hyperlipidemias and cardiovascular diseases.


Assuntos
Apolipoproteínas B , Carcinoma Hepatocelular , Hepatócitos , Neoplasias Hepáticas , Apolipoproteínas B/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Células Cultivadas , Hepatócitos/efeitos dos fármacos , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , MicroRNAs/farmacologia
8.
J Biol Chem ; 298(3): 101685, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35131264

RESUMO

Most mammalian phospholipids contain a saturated fatty acid at the sn-1 carbon atom and an unsaturated fatty acid at the sn-2 carbon atom of the glycerol backbone group. While the sn-2 linked chains undergo extensive remodeling by deacylation and reacylation (Lands cycle), it is not known how the composition of saturated fatty acids is controlled at the sn-1 position. Here, we demonstrate that lysophosphatidylglycerol acyltransferase 1 (LPGAT1) is an sn-1 specific acyltransferase that controls the stearate/palmitate ratio of phosphatidylethanolamine (PE) and phosphatidylcholine. Bacterially expressed murine LPGAT1 transferred saturated acyl-CoAs specifically into the sn-1 position of lysophosphatidylethanolamine (LPE) rather than lysophosphatidylglycerol and preferred stearoyl-CoA over palmitoyl-CoA as the substrate. In addition, genetic ablation of LPGAT1 in mice abolished 1-LPE:stearoyl-CoA acyltransferase activity and caused a shift from stearate to palmitate species in PE, dimethyl-PE, and phosphatidylcholine. Lysophosphatidylglycerol acyltransferase 1 KO mice were leaner and had a shorter life span than their littermate controls. Finally, we show that total lipid synthesis was reduced in isolated hepatocytes of LPGAT1 knockout mice. Thus, we conclude that LPGAT1 is an sn-1 specific LPE acyltransferase that controls the stearate/palmitate homeostasis of PE and the metabolites of the PE methylation pathway and that LPGAT1 plays a central role in the regulation of lipid biosynthesis with implications for body fat content and longevity.


Assuntos
Aciltransferases , Palmitatos , Fosfatidilcolinas , Estearatos , Aciltransferases/metabolismo , Animais , Carbono , Ácidos Graxos , Mamíferos/metabolismo , Camundongos , Camundongos Knockout , Palmitatos/metabolismo , Fosfatidilcolinas/metabolismo , Fosfatidiletanolaminas , Estearatos/metabolismo
9.
J Biol Chem ; 298(10): 102411, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36007616

RESUMO

Sphingomyelin (SM) is an abundant plasma membrane and plasma lipoprotein sphingolipid. We previously reported that ATP-binding cassette family A protein 1 (ABCA1) deficiency in humans and mice decreases plasma SM levels. However, overexpression, induction, downregulation, inhibition, and knockdown of ABCA1 in human hepatoma Huh7 cells did not decrease SM efflux. Using unbiased siRNA screening, here, we identified that ABCA7 plays a role in the biosynthesis and efflux of SM without affecting cellular uptake and metabolism. Since loss of function mutations in the ABCA7 gene exhibit strong associations with late-onset Alzheimer's disease across racial groups, we also studied the effects of ABCA7 deficiency in the mouse brain. Brains of ABCA7-deficient (KO) mice, compared with WT, had significantly lower levels of several SM species with long chain fatty acids. In addition, we observed that older KO mice exhibited behavioral deficits in cognitive discrimination in the active place avoidance task. Next, we performed synaptic transmission studies in brain slices obtained from older mice. We found anomalies in synaptic plasticity at the intracortical synapse in layer II/III of the lateral entorhinal cortex but not in the hippocampal CA3-CA1 synapses in KO mice. These synaptic abnormalities in KO brain slices were rescued with extracellular SM supplementation but not by supplementation with phosphatidylcholine. Taken together, these studies identify a role of ABCA7 in brain SM metabolism and the importance of SM in synaptic plasticity and cognition, as well as provide a possible explanation for the association between ABCA7 and late-onset Alzheimer's disease.


Assuntos
Doença de Alzheimer , Cognição , Córtex Entorrinal , Plasticidade Neuronal , Esfingomielinas , Animais , Humanos , Camundongos , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Córtex Entorrinal/metabolismo , Esfingomielinas/biossíntese , Camundongos Knockout
10.
Cancer Immunol Immunother ; 72(12): 4221-4234, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37940720

RESUMO

Renal cell carcinoma is an immunogenic tumour with a prominent dysfunctional immune cell infiltrate, unable to control tumour growth. Although tyrosine kinase inhibitors and immunotherapy have improved the outlook for some patients, many individuals are non-responders or relapse despite treatment. The hostile metabolic environment in RCC affects the ability of T-cells to maintain their own metabolic programme constraining T-cell immunity in RCC. We investigated the phenotype, function and metabolic capability of RCC TILs correlating this with clinicopathological features of the tumour and metabolic environment at the different disease stages. Flow cytometric analysis of freshly isolated TILs showed the emergence of exhausted T-cells in advanced disease based on their PD-1high and CD39 expression and reduced production of inflammatory cytokines upon in vitro stimulation. Exhausted T-cells from advanced stage disease also displayed an overall phenotype of metabolic insufficiency, characterized by mitochondrial alterations and defects in glucose uptake. Nanostring nCounter cancer metabolism assay on RNA obtained from 30 ccRCC cases revealed significant over-expression of metabolic genes even at early stage disease (pT1-2), while at pT3-4 and the locally advanced thrombi stages, there was an overall decrease in differentially expressed metabolic genes. Notably, the gene PPARGC1A was the most significantly down-regulated gene from pT1-2 to pT3-4 RCC which correlated with loss of mitochondrial function in tumour-infiltrating T-cells evident at this tumour stage. Down-regulation of PPARGC1A into stage pT3-4 may be the 'tipping-point' in RCC disease progression, modulating immune activity in ccRCC and potentially reducing the efficacy of immunotherapies in RCC and poorer patient outcomes.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Carcinoma de Células Renais/patologia , Neoplasias Renais/patologia , Recidiva Local de Neoplasia , Progressão da Doença , Imunidade
11.
Hepatology ; 76(1): 78-93, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34626126

RESUMO

BACKGROUND AND AIMS: High plasma lipid/lipoprotein levels are risk factors for various metabolic diseases. We previously showed that circadian rhythms regulate plasma lipids and deregulation of these rhythms causes hyperlipidemia and atherosclerosis in mice. Here, we show that global and liver-specific brain and muscle aryl hydrocarbon receptor nuclear translocator-like 1 (Bmal1)-deficient mice maintained on a chow or Western diet developed hyperlipidemia, denoted by the presence of higher amounts of triglyceride-rich and apolipoprotein AIV (ApoAIV)-rich larger chylomicron and VLDL due to overproduction. APPROACH AND RESULTS: Bmal1 deficiency decreased small heterodimer partner (Shp) and increased microsomal triglyceride transfer protein (MTP), a key protein that facilitates primordial lipoprotein assembly and secretion. Moreover, we show that Bmal1 regulates cAMP-responsive element-binding protein H (Crebh) to modulate ApoAIV expression and the assembly of larger lipoproteins. This is supported by the observation that Crebh-deficient and ApoAIV-deficient mice, along with Bmal1-deficient mice with knockdown of Crebh, had smaller lipoproteins. Further, overexpression of Bmal1 in Crebh-deficient mice had no effect on ApoAIV expression and lipoprotein size. CONCLUSIONS: These studies indicate that regulation of ApoAIV and assembly of larger lipoproteins by Bmal1 requires Crebh. Mechanistic studies showed that Bmal1 regulates Crebh expression by two mechanisms. First, Bmal1 interacts with the Crebh promoter to control circadian regulation. Second, Bmal1 increases Rev-erbα expression, and nuclear receptor subfamily 1 group D member 1 (Nr1D1, Rev-erbα) interacts with the Crebh promoter to repress expression. In short, Bmal1 modulates both the synthesis of primordial lipoproteins and their subsequent expansion into larger lipoproteins by regulating two different proteins, MTP and ApoAIV, through two different transcription factors, Shp and Crebh. It is likely that disruptions in circadian mechanisms contribute to hyperlipidemia and that avoiding disruptions in circadian rhythms may limit/prevent hyperlipidemia and atherosclerosis.


Assuntos
Fatores de Transcrição ARNTL/metabolismo , Aterosclerose , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Hiperlipidemias , Animais , Apolipoproteínas A/metabolismo , Aterosclerose/metabolismo , Camundongos , Camundongos Endogâmicos C57BL
12.
Curr Atheroscler Rep ; 25(5): 209-217, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36913170

RESUMO

PURPOSE OF REVIEW: This review is aimed at providing an overview of new developments in gene editing technology, including examples of how this technology has been used to develop cell models for studying the effects of gene ablation or missense mutations on lipoprotein assembly and secretion. RECENT FINDINGS: CRISPR/Cas9-mediated gene editing is superior to other technologies because of its ease, sensitivity, and low off-target effects. This technology has been used to study the importance of microsomal triglyceride transfer protein in the assembly and secretion of apolipoprotein B-containing lipoproteins, as well as to establish causal effects of APOB gene missense mutations on lipoprotein assembly and secretion. CRISPR/Cas9 technology is anticipated to provide unprecedented flexibility in studying protein structure and function in cells and animals and to yield mechanistic insights into variants in the human genome.


Assuntos
Apolipoproteínas B , Lipoproteínas , Animais , Humanos , Edição de Genes
13.
BJU Int ; 131(1): 73-81, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35986901

RESUMO

OBJECTIVES: To report the management outcomes of men with ≤20-mm small testicular masses (STMs) and to identify clinical and histopathological factors associated with malignancy. PATIENTS AND METHODS: A retrospective analysis of men managed at a single centre between January 2010 and December 2020 with a STM ≤20 mm in size was performed. RESULTS: Overall, 307 men with a median (interquartile range [IQR]) age of 36 (30-44) years were included. Of these, 161 (52.4%), 82 (26.7%), 62 (20.2%) and 2 men (0.7%) underwent surveillance with interval ultrasonography (USS), primary excisional testicular biopsy (TBx) or primary radical orchidectomy (RO), or were discharged, respectively. The median (IQR) surveillance duration was 6 (3-18) months. The majority of men who underwent surveillance had lesions <5 mm (59.0%) and no lesion vascularity (67.1%) on USS. Thirty-three (20.5%) men undergoing surveillance had a TBx based on changes on interval USS or patient choice; seven (21.2%) were found to be malignant. The overall rate of malignancy in the surveillance cohort was 4.3%. The majority of men who underwent primary RO had lesions ≥10 mm (85.5%) and the presence of vascularity (61.7%) on USS. Nineteen men (23.2%) who underwent primary TBx (median lesion size 6 mm) had a malignancy confirmed on biopsy and underwent RO. A total of 88 men (28.7%) underwent RO, and malignancy was confirmed in 73 (83.0%) of them. The overall malignancy rate in the whole STM cohort was 23.8%. Malignant RO specimens had significantly larger lesion sizes (median [IQR] 11 [8-15] mm, vs benign: median [IQR] 8 [5-10] mm; P = 0.04). CONCLUSIONS: Small testicular masses can be stratified and managed based on lesion size and USS features. The overall malignancy rate in men with an STM was 23.8% (4.3% in the surveillance group). Surveillance should be considered in lesions <10 mm in size, with a TBx or frozen-section examination offered prior to RO in order to preserve testicular function.


Assuntos
Neoplasias Testiculares , Masculino , Humanos , Adulto , Feminino , Neoplasias Testiculares/cirurgia , Neoplasias Testiculares/diagnóstico , Estudos Retrospectivos , Orquiectomia , Secções Congeladas , Edema , Equipe de Assistência ao Paciente
14.
BJU Int ; 132(3): 337-342, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37169730

RESUMO

OBJECTIVE: To report the oncological survival outcomes of men with penile sarcomatoid squamous cell carcinoma (sSCC). PATIENTS AND METHODS: A retrospective analysis of men with penile sSCC diagnosed between January 2010 and January 2020 in a single centre was conducted. Disease-specific (DSS), recurrence-free (RFS) and metastasis-free (MFS) survival were evaluated. Outcomes were compared with a non-sarcomatoid penile SCC cohort matched to age, type of surgery and tumour stage. Kaplan-Meier plots were used to estimate survival outcomes. RESULTS: In all, 1286 men were diagnosed with penile SCC during the study period and of these 38 (3%) men had sSCC. The median (interquartile range) age and follow-up was 70 (57-81) years and 16 (7-44) months, respectively. Operations performed included: circumcision, one (2.6%); wide local excision, four (10.5%); glansectomy, 11 (29%); partial penectomy, 10 (26%); subtotal/total penectomy, 12 (32%). The Kaplan-Meier estimated 12-, 24- and 36-month DSS was 62% (vs non-sarcomatoid, 67%), 43% (vs non-sarcomatoid, 67%) and 36% (vs non-sarcomatoid, 67%), respectively (P = 0.03). The Kaplan-Meier estimated 12- and 24-month RFS was 47% (vs non-sarcomatoid, 60%) and 28% (vs non-sarcomatoid, 55%), respectively (P = 0.01). The MFS was 52% (vs non-sarcomatoid, 62%) at 12 months and 37% (vs non-sarcomatoid, 57%) at 24 months (P = 0.04). CONCLUSIONS: Sarcomatoid differentiation was associated with a lower DSS, RFS and MFS. Due to the rarity of its incidence and aggressiveness, expert histological review and multidisciplinary management is required in a specialist penile cancer centre.

15.
BMC Geriatr ; 23(1): 536, 2023 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-37667196

RESUMO

OBJECTIVES: The relationship between handgrip strength (HGS) and quality of life is inconsistent. The purpose of this study was to investigate the potential association between HGS and quality of life in the settings of ageing and Alzheimer's disease (AD). METHODS: We investigated the HGS, CASP-12 (control, autonomy, self-realization, and pleasure) measure of quality of life, and physical capacity in European adults above 50, including controls (n = 38,628) and AD subjects (n = 460) using the survey of health, ageing, and retirement in Europe (SHARE; 2022). RESULTS: AD subjects exhibited lower HGS and CASP-12 scores than controls (both p < 0.05). Participants with higher CASP-12 quartiles had higher HGS in controls but not in AD subjects. A linear positive relation was found between HGS and CASP-12 in controls (0.0842, p < 0.05) but not in AD subjects (0.0636, p = 0.091). There was no effect of gender on this finding. Lastly, we found significant negative associations of difficulties walking, rising from chair, climbing stairs, and fatigue with CASP-12 scores in controls and AD subjects (all p < 0.05). CONCLUSIONS: Altogether, HGS was not associated with quality of life in individuals with AD. Conversely, difficulties in activities of daily living seem to be negatively associated with quality of life; thus, strategies are recommended to improve physical capacity.


Assuntos
Doença de Alzheimer , Qualidade de Vida , Humanos , Atividades Cotidianas , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/epidemiologia , Força da Mão , Europa (Continente)/epidemiologia
16.
PLoS Genet ; 16(8): e1008941, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32760060

RESUMO

Apolipoprotein B-containing lipoproteins (B-lps) are essential for the transport of hydrophobic dietary and endogenous lipids through the circulation in vertebrates. Zebrafish embryos produce large numbers of B-lps in the yolk syncytial layer (YSL) to move lipids from yolk to growing tissues. Disruptions in B-lp production perturb yolk morphology, readily allowing for visual identification of mutants with altered B-lp metabolism. Here we report the discovery of a missense mutation in microsomal triglyceride transfer protein (Mtp), a protein that is essential for B-lp production. This mutation of a conserved glycine residue to valine (zebrafish G863V, human G865V) reduces B-lp production and results in yolk opacity due to aberrant accumulation of cytoplasmic lipid droplets in the YSL. However, this phenotype is milder than that of the previously reported L475P stalactite (stl) mutation. MTP transfers lipids, including triglycerides and phospholipids, to apolipoprotein B in the ER for B-lp assembly. In vitro lipid transfer assays reveal that while both MTP mutations eliminate triglyceride transfer activity, the G863V mutant protein unexpectedly retains ~80% of phospholipid transfer activity. This residual phospholipid transfer activity of the G863V mttp mutant protein is sufficient to support the secretion of small B-lps, which prevents intestinal fat malabsorption and growth defects observed in the mttpstl/stl mutant zebrafish. Modeling based on the recent crystal structure of the heterodimeric human MTP complex suggests the G865V mutation may block triglyceride entry into the lipid-binding cavity. Together, these data argue that selective inhibition of MTP triglyceride transfer activity may be a feasible therapeutic approach to treat dyslipidemia and provide structural insight for drug design. These data also highlight the power of yolk transport studies to identify proteins critical for B-lp biology.


Assuntos
Proteínas de Transporte/genética , Lipídeos/genética , Lipoproteínas/genética , Triglicerídeos/genética , Animais , Fígado Gorduroso/genética , Fígado Gorduroso/patologia , Trato Gastrointestinal/metabolismo , Humanos , Imunoprecipitação , Gotículas Lipídicas/metabolismo , Lipoproteínas/metabolismo , Mutação de Sentido Incorreto/genética , Mutação Puntual/genética , Transporte Proteico/genética , Triglicerídeos/metabolismo , Peixe-Zebra/genética
17.
Neurocrit Care ; 39(3): 677-689, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36577900

RESUMO

BACKGROUND: The utility of head computed tomography (CT) in predicting elevated intracranial pressure (ICP) is known to be limited in traumatic brain injury; however, few data exist in patients with spontaneous intracranial hemorrhage. METHODS: We conducted a retrospective review of prospectively collected data in patients with nontraumatic intracranial hemorrhage (subarachnoid hemorrhage [SAH] or intraparenchymal hemorrhage [IPH]) who underwent external ventricular drain (EVD) placement. Head CT scans performed immediately prior to EVD placement were quantitatively reviewed for features suggestive of elevated ICP, including temporal horn diameter, bicaudate index, basal cistern effacement, midline shift, and global cerebral edema. The modified Fisher score (mFS), intraventricular hemorrhage score, and IPH volume were also measured, as applicable. We calculated the accuracy, positive predictive value (PPV), and negative predictive value (NPV) of these radiographic features for the coprimary outcomes of elevated ICP (> 20 mm Hg) at the time of EVD placement and at any time during the hospital stay. Multivariable backward stepwise logistic regression analysis was performed to identify significant radiographic factors associated with elevated ICP. RESULTS: Of 608 patients with intracranial hemorrhages enrolled during the study time frame, 243 (40%) received an EVD and 165 (n = 107 SAH, n = 58 IPH) had a preplacement head CT scan available for rating. Elevated opening pressure and elevated ICP during hospitalization were recorded in 48 of 152 (29%) and 103 of 165 (62%), respectively. The presence of ≥ 1 radiographic feature had only 32% accuracy for identifying elevated opening pressure (PPV 30%, NPV 58%, area under the curve [AUC] 0.537, 95% asymptotic confidence interval [CI] 0.436-0.637, P = 0.466) and 59% accuracy for predicting elevated ICP during hospitalization (PPV 63%, NPV 40%, AUC 0.514, 95% asymptotic CI 0.391-0.638, P = 0.820). There was no significant association between the number of radiographic features and ICP elevation. Head CT scans without any features suggestive of elevated ICP occurred in 25 of 165 (15%) patients. However, 10 of 25 (40%) of these patients had elevated opening pressure, and 15 of 25 (60%) had elevated ICP during their hospital stay. In multivariable models, mFS (adjusted odds ratio [aOR] 1.36, 95% CI 1.10-1.68) and global cerebral edema (aOR 2.93, 95% CI 1.27-6.75) were significantly associated with elevated ICP; however, their accuracies were only 69% and 60%, respectively. All other individual radiographic features had accuracies between 38 and 58% for identifying intracranial hypertension. CONCLUSIONS: More than 50% of patients with spontaneous intracranial hemorrhage without radiographic features suggestive of elevated ICP actually had ICP > 20 mm Hg during EVD placement or their hospital stay. Morphological head CT findings were only 32% and 59% accurate in identifying elevated opening pressure and ICP elevation during hospitalization, respectively.


Assuntos
Edema Encefálico , Hipertensão Intracraniana , Hemorragia Subaracnóidea , Humanos , Hipertensão Intracraniana/diagnóstico por imagem , Hipertensão Intracraniana/etiologia , Hemorragias Intracranianas/complicações , Hemorragias Intracranianas/diagnóstico por imagem , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Pressão Intracraniana
18.
Br J Neurosurg ; 37(4): 886-888, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31790284

RESUMO

INTRODUCTION: Achondroplasia is a genetic disorder known for short stature and skeletal abnormalities. CASE REPORT: We present a case of narrowing of the foramen magnum from a large opisthion extending to the spinal canal. CONCLUSION: Foramen magnum stenosis and cervicomedullary stenosis are potentially life threatening neurological manifestations of achondroplasia.


Assuntos
Acondroplasia , Compressão da Medula Espinal , Humanos , Lactente , Constrição Patológica/etiologia , Constrição Patológica/cirurgia , Forame Magno/diagnóstico por imagem , Forame Magno/cirurgia , Acondroplasia/complicações , Compressão da Medula Espinal/diagnóstico por imagem , Compressão da Medula Espinal/etiologia , Compressão da Medula Espinal/cirurgia
19.
Int J Mol Sci ; 24(22)2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-38003484

RESUMO

Apolipoprotein CII (ApocII) plays a key role in regulating lipoprotein lipase (LPL) in lipid metabolism and transport. Numerous polymorphisms within APOCII are reportedly associated with type 2 diabetes mellitus (T2DM), dyslipidemia, and aberrant plasma lipid levels. Few studies have investigated sequence variants at APOCII loci and their association with metabolic disorders. This study aimed to identify and characterize genetic variants by sequencing the full APOCII locus and its flanking sequences in a sample of the Kuwaiti Arab population, including patients with T2DM, hypertriglyceridemia, non-Arab patients with T2DM, and healthy Arab controls. A total of 52 variants were identified in the noncoding sequences: 45 single nucleotide polymorphisms, wherein five were novel, and seven insertion deletions. The minor allele frequency (MAF) of the 47 previously reported variants was similar to the global MAF and to that reported in major populations. Sequence variant analysis predicted a conserved role for APOCII with a potential role for rs5120 in T2DM and rs7133873 as an informative ethnicity marker. This study adds to the ongoing research that attempts to identify ethnicity-specific variants in the apolipoprotein gene loci and associated LPL genes to elucidate the molecular mechanisms of metabolic disorders.


Assuntos
Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/genética , Árabes/genética , Apolipoproteína C-II , Apolipoproteínas
20.
J Stroke Cerebrovasc Dis ; 32(10): 107324, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37660553

RESUMO

OBJECTIVE/AIM: To investigate the effect of cerebral microbleeds (CMBs) on the functional and safety outcomes of endovascular thrombectomy (EVT) in patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO). METHODS: This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines for systematic review and meta-analysis. We included observational studies that recruited AIS-LVO patients, used susceptibility-sensitive magnetic resonance imaging (MRI) to detect CMBs, and examined the association between them and predefined outcome events. The extracted data included study and population characteristics, risk of bias domains, and outcome measures. The outcomes of interest included functional independence, revascularization success, procedural and hemorrhagic adverse events. We conducted a meta-analysis using the Mantel-Haenszel method and calculated the risk ratios. RESULTS: Four studies with a total of 1,514 patients were included. A significant reduction in the likelihood of achieving a favorable functional outcome was observed in patients with CMBs (Risk ratio (RR) 0.69, 95% confidence interval (CI): 0.52 to 0.91, P=0.01). No significant differences were observed between the CMBs and no CMBs groups in terms of successful revascularization, mortality, intracranial hemorrhage (ICH), subarachnoid hemorrhage (SAH), and parenchymal hematoma. CONCLUSIONS: The presence of CMBs significantly reduced the likelihood of achieving functional independence post-EVT in AIS-LVO patients. However, CMBs did not impact the rates of successful revascularization, mortality, or the occurrence of various hemorrhagic events. Future research should explore the mechanisms of this association and strategies to mitigate its impact.


Assuntos
AVC Isquêmico , Hemorragia Subaracnóidea , Humanos , Trombectomia/efeitos adversos , Hemorragias Intracranianas/diagnóstico por imagem , Hemorragias Intracranianas/etiologia , Hemorragia Cerebral/diagnóstico por imagem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA