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1.
Am J Gastroenterol ; 119(1): 107-115, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-37011138

RESUMO

INTRODUCTION: This study is to evaluate the safety and pharmacokinetics (PK) of larsucosterol (DUR-928 or 25HC3S) in subjects with alcohol-associated hepatitis (AH), a devastating acute illness without US Food and Drug Administration-approved therapies. METHODS: This phase 2a, multicenter, open-label, dose escalation study evaluated the safety, PK, and efficacy signals of larsucosterol in 19 clinically diagnosed subjects with AH. Based on the model for end-stage liver disease (MELD) score, 7 subjects were considered to have moderate AH and 12 to have severe AH. All subjects received 1 or 2 intravenous infusions (72 hours apart) of larsucosterol at a dose of 30, 90, or 150 mg and were followed up for 28 days. Efficacy signals from a subgroup of subjects with severe AH were compared with those from 2 matched arms of those with severe AH treated with standard of care (SOC), including corticosteroids, from a contemporaneous study. RESULTS: All 19 larsucosterol-treated subjects survived the 28-day study. Fourteen (74%) of all subjects including 8 (67%) of the subjects with severe AH were discharged ≤72 hours after receiving a single infusion. There were no drug-related serious adverse events nor early terminations due to the treatment. PK profiles were not affected by disease severity. Biochemical parameters improved in most subjects. Serum bilirubin levels declined notably from baseline to day 7 and day 28, and MELD scores were reduced at day 28. The efficacy signals compared favorably with those from 2 matched groups treated with SOC. Lille scores at day 7 were <0.45 in 16 of the 18 (89%) subjects with day 7 samples. Lille scores from 8 subjects with severe AH who received 30 or 90 mg larsucosterol (doses used in phase 2b trial) were statistically significantly lower ( P < 0.01) than those from subjects with severe AH treated with SOC from the contemporaneous study. DISCUSSION: Larsucosterol was well tolerated at all 3 doses in subjects with AH without safety concerns. Data from this pilot study showed promising efficacy signals in subjects with AH. Larsucosterol is being evaluated in a phase 2b multicenter, randomized, double-blinded, placebo-controlled (AHFIRM) trial.


Assuntos
Doença Hepática Terminal , Hepatite Alcoólica , Humanos , Projetos Piloto , Índice de Gravidade de Doença , Hepatite Alcoólica/tratamento farmacológico , Hepatite Alcoólica/diagnóstico
2.
Int J Mol Sci ; 24(1)2022 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-36613673

RESUMO

Adipose tissue is a dynamic endocrine organ, secreting a plethora of adipokines which play a key role in regulating metabolic homeostasis and other physiological processes. An altered adipokine secretion profile from adipose tissue depots has been associated with obesity and related cardio-metabolic diseases. Asprosin is a recently described adipokine that is released in response to fasting and can elicit orexigenic and glucogenic effects. Circulating asprosin levels are elevated in a number of cardio-metabolic diseases, including obesity and type 2 diabetes. In vitro studies have reported pro-inflammatory effects of asprosin in a variety of tissues. The present study aimed to further elucidate the role of asprosin in inflammation by exploring its potential effect(s) in THP-1 macrophages. THP-1 monocytes were differentiated to macrophages by 48 h treatment with dihydroxyvitamin D3. Macrophages were treated with 100 nM recombinant human asprosin, 100 ng/mL lipopolysaccharide (LPS), and 10 µM caffeic acid phenethyl ester (CAPE; an inhibitor of NFκB activation) or 1 µM TAK-242 (a Toll-like receptor 4, TLR4, inhibitor). The expression and secretion of pertinent pro-inflammatory mediators were measured by qPCR, Western blot, ELISA and Bioplex. Asprosin stimulation significantly upregulated the expression and secretion of the pro-inflammatory cytokines: tumour necrosis factor α (TNFα), interleukin-1ß (IL-1ß), IL-8 and IL-12 in vitro. This pro-inflammatory response in THP-1 macrophages was partly attenuated by the treatments with CAPE and was significantly inhibited by TAK-242 treatment. Asprosin-induced inflammation is significantly counteracted by TLR4 inhibition in THP-1 macrophages, suggesting that asprosin exerts its pro-inflammatory effects, at least in part, via the TLR4 signalling pathway.


Assuntos
Adipocinas , Diabetes Mellitus Tipo 2 , Macrófagos , Receptor 4 Toll-Like , Humanos , Adipocinas/farmacologia , Diabetes Mellitus Tipo 2/metabolismo , Inflamação/metabolismo , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Receptor 4 Toll-Like/metabolismo , Células THP-1
3.
J Lipid Res ; 62: 100063, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33705741

RESUMO

The oxysterol sulfate, 25-hydroxycholesterol 3-sulfate (25HC3S), has been shown to play an important role in lipid metabolism, inflammatory response, and cell survival. However, the mechanism(s) of its function in global regulation is unknown. The current study investigates the molecular mechanism by which 25HC3S functions as an endogenous epigenetic regulator. To study the effects of oxysterols/sterol sulfates on epigenetic modulators, 12 recombinant epigenetic enzymes were used to determine whether 25HC3S acts as their endogenous ligand. The enzyme kinetic study demonstrated that 25HC3S specifically inhibited DNA methyltransferases (DNMTs), DNMT1, DNMT3a, and DNMT3b with IC50 of 4.04, 3.03, and 9.05 × 10-6 M, respectively. In human hepatocytes, high glucose induces lipid accumulation by increasing promoter CpG methylation of key genes involved in development of nonalcoholic fatty liver diseases. Using this model, whole genome bisulfate sequencing analysis demonstrated that 25HC3S converts the 5mCpG to CpG in the promoter regions of 1,074 genes. In addition, we observed increased expression of the demethylated genes, which are involved in the master signaling pathways, including MAPK-ERK, calcium-AMP-activated protein kinase, and type II diabetes mellitus pathways. mRNA array analysis showed that the upregulated genes encoded for key elements of cell survival; conversely, downregulated genes encoded for key enzymes that decrease lipid biosynthesis. Taken together, our results indicate that the expression of these key elements and enzymes are regulated by the demethylated signaling pathways. We summarized that 25HC3S DNA demethylation of 5mCpG in promoter regions is a potent regulatory mechanism.


Assuntos
Ésteres do Colesterol , Hidroxicolesteróis
4.
Fuel (Lond) ; 2642020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33364633

RESUMO

Emissions generated from the combustion of coal have been a subject of regulation by the United States Environmental Protection Agency (U.S. EPA) and State agencies for years, as they have been associated with adverse effects on human health and the environment. Over the past several decades, regulations on these facility emissions have become more stringent and have therefore caused industry to look toward new pre- and post-combustion control technologies. In more recent years, there has been a "push" toward renewable and cleaner burning alternative fuels as replacements for traditional fossil fuels. Part of this "push" has been accomplished by States and Regions offering incentives and options for renewable portfolios, which over half of the states now have in some form. The current study investigates the potential changes in both gaseous and particulate emissions from the use of a variety of woody biomass materials as a drop-in replacement for coal as compared to use of 100% bituminous coal. Four different biomass materials are blended individually with coal at 20% and 40% by mass for testing on the U.S. EPA's Multi-Pollutant Control Research Facility, a pilot-scale coal-fired facility located in Research Triangle Park, North Carolina. Emissions are calculated based on measurements from the flue gas to characterize gaseous species (CO, CO2, NOX, SO2, other acid gases, and several organic hazardous air pollutants) as well as fine and ultrafine particulate (mass, size distribution, number count, elemental carbon, organic carbon, and black carbon) and compared among each combination of fuels and 100% bituminous coal.

5.
Int J Mol Sci ; 21(20)2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33081264

RESUMO

ABCC1 and ABCC4 utilize energy from ATP hydrolysis to transport many different molecules, including drugs, out of the cell and, as such, have been implicated in causing drug resistance. However recently, because of their ability to transport signaling molecules and inflammatory mediators, it has been proposed that ABCC1 and ABCC4 may play a role in the hallmarks of cancer development and progression, independent of their drug efflux capabilities. Breast cancer is the most common cancer affecting women. In this study, the aim was to investigate whether ABCC1 or ABCC4 play a role in the proliferation or migration of breast cancer cell lines MCF-7 (luminal-type, receptor-positive) and MDA-MB-231 (basal-type, triple-negative). The effects of small molecule inhibitors or siRNA-mediated knockdown of ABCC1 or ABCCC4 were measured. Colony formation assays were used to assess the clonogenic capacity, MTT assays to measure the proliferation, and scratch assays and Transwell assays to monitor the cellular migration. The results showed a role for ABCC1 in cellular proliferation, whilst ABCC4 appeared to be more important for cellular migration. ELISA studies implicated cAMP and/or sphingosine-1-phosphate efflux in the mechanism by which these transporters mediate their effects. However, this needs to be investigated further, as it is key to understand the mechanisms before they can be considered as targets for treatment.


Assuntos
Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Movimento Celular , Proliferação de Células , AMP Cíclico/metabolismo , Humanos , Lisofosfolipídeos/metabolismo , Células MCF-7 , Proteínas Associadas à Resistência a Múltiplos Medicamentos/antagonistas & inibidores , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Receptor ErbB-2/genética , Esfingosina/análogos & derivados , Esfingosina/metabolismo , Neoplasias de Mama Triplo Negativas/genética
6.
Fuel (Lond) ; 215: 572-279, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-31595088

RESUMO

Gaseous and particulate emissions generated from the combustion of coal have been associated with adverse effects on human health and the environment, and have therefore been the subject of regulation by federal and state government agencies. Detailed emission characterizations are needed to better understand the impacts of pre- and post-combustion controls on a variety of coals found in the United States (U.S.). While the U.S. Environmental Protection Agency (EPA) requires industry reporting of emissions for criteria and several hazardous air pollutants (HAPs), many of the methods for monitoring and measuring these gaseous and particulate emissions rely on time-integrated sampling techniques. Though these emissions reports provide an overall representation of day-to-day operations, they represent well-controlled operations and do not encompass real combustion events that occur sporadically. The current study not only characterizes emissions from three coals (bituminous, sub-bituminous, and lignite), but also investigates the use of instrumentation for improved measurement and monitoring techniques that provide real-time, continuous emissions data. Testing was completed using the U.S. EPA's Multi-Pollutant Control Research Facility, a pilot-scale coal-fired combustor using industry-standard emission control technologies, in Research Triangle Park, North Carolina. Emissions were calculated based on measurements from the flue gas (pre- and post-electrostatic precipitator), to characterize gaseous species (CO, CO2, O2, NOX, SO2, other acid gases, and several organic HAPs) as well as fine and ultrafine particulate (mass, size distribution, number count, elemental carbon, organic carbon, and black carbon). Comparisons of traditional EPA methods to those made via Fourier Transfer Infrared (FTIR) Spectroscopy for CO, NOX, and SO2 are also reported.

7.
Eur J Neurosci ; 46(9): 2542-2547, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28925524

RESUMO

Human aquaporin 4 (AQP4) is the primary water channel protein in brain astrocytes. Hypothermia is known to cause astrocyte swelling in culture, but the precise role of AQP4 in this process is unknown. Primary human cortical astrocytes were cultured under hypothermic (32 °C) or normothermic (37 °C) conditions. AQP4 transcript, total protein and surface-localized protein were quantified using RT-qPCR, sandwich ELISA with whole cell lysates or cell surface biotinylation, followed by ELISA analysis of the surface-localized protein, respectively. Four-hour mild hypothermic treatment increased the surface localization of AQP4 in human astrocytes to 155 ± 4% of normothermic controls, despite no change in total protein expression levels. The hypothermia-mediated increase in AQP4 surface abundance on human astrocytes was blocked using either calmodulin antagonist (trifluoperazine, TFP); TRPV4 antagonist, HC-067047 or calcium chelation using EGTA-AM. The TRPV4 agonist (GSK1016790A) mimicked the effect of hypothermia compared with untreated normothermic astrocytes. Hypothermia led to an increase in surface localization of AQP4 in human astrocytes through a mechanism likely dependent on the TRPV4 calcium channel and calmodulin activation. Understanding the effects of hypothermia on astrocytic AQP4 cell surface expression may help develop new treatments for brain swelling based on an in-depth mechanistic understanding of AQP4 translocation.


Assuntos
Aquaporina 4/metabolismo , Astrócitos/metabolismo , Calmodulina/metabolismo , Córtex Cerebral/metabolismo , Hipotermia/metabolismo , Canais de Cátion TRPV/metabolismo , Aquaporina 4/antagonistas & inibidores , Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Cálcio/metabolismo , Calmodulina/antagonistas & inibidores , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Membrana Celular/patologia , Células Cultivadas , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/patologia , Transportador 1 de Aminoácido Excitatório/metabolismo , Humanos , Hipotermia/patologia , Hipotermia Induzida , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , RNA Mensageiro/metabolismo , Canais de Cátion TRPV/agonistas
8.
Cardiovasc Diabetol ; 16(1): 147, 2017 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-29121940

RESUMO

BACKGROUND: Irisin is a hormone released mainly from skeletal muscle after exercise which increases adipose tissue energy expenditure. Adipocytes can also release irisin after exercise, acting as a local adipokine to induce white adipose tissue to take on a brown adipose tissue-like phenotype, suggesting that irisin and its receptor may represent a novel molecular target for the treatment of obesity and obesity-related diabetes. Previous reports provide conflicting evidence regarding circulating irisin levels in patients with type 2 diabetes (T2DM). METHODS: This study investigated plasma irisin concentrations in 79 T2DM individuals, assessing potential associations with measures of segmental body composition, markers of endothelial dysfunction and peripheral blood mononuclear cell telomere length (TL). RESULTS: Resting, overnight-fasted plasma irisin levels were significantly higher in this group of T2DM patients compared with levels we previously reported in healthy volunteers (p < 0.001). Moreover, plasma irisin displayed a positive correlation with body mass index (p = 0.04), body fat percentage (p = 0.03), HbA1c (p = 0.03) and soluble E-selectin (p < 0.001). A significant negative association was observed between plasma irisin and visceral adiposity (p = 0.006) in T2DM patients. Multiple regression analysis revealed that circulating soluble E-selectin levels could be predicted by plasma irisin (p = 0.004). Additionally, cultured human umbilical vein endothelial cells (HUVEC) exposed to 200 ng/ml irisin for 4 h showed a significant fourfold increase in E-selectin and 2.5-fold increase in ICAM-1 gene expression (p = 0.001 and p = 0.015 respectively), and there was a 1.8-fold increase in soluble E-selectin in conditioned media (p < 0.05). CONCLUSION: These data suggest that elevated plasma irisin in T2DM is associated with indices of adiposity, and that irisin may be involved in pro-atherogenic endothelial disturbances that accompany obesity and T2DM. Accordingly, irisin may constitute a potentially novel therapeutic opportunity in the field of obesity and cardiovascular diabetology.


Assuntos
Adiposidade/fisiologia , Índice de Massa Corporal , Diabetes Mellitus Tipo 2/sangue , Selectina E/sangue , Fibronectinas/sangue , Adulto , Idoso , Biomarcadores/sangue , Diabetes Mellitus Tipo 2/fisiopatologia , Feminino , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade
9.
Arterioscler Thromb Vasc Biol ; 34(10): 2310-20, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25147342

RESUMO

OBJECTIVE: Vascular endothelial growth factor (VEGF) has been identified as a crucial regulator of physiological and pathological angiogenesis. Among the intracellular signaling pathways triggered by VEGF, activation of the calcineurin/nuclear factor of activated T cells (NFAT) signaling axis has emerged as a critical mediator of angiogenic processes. We and others previously reported a novel role for the plasma membrane calcium ATPase (PMCA) as an endogenous inhibitor of the calcineurin/NFAT pathway, via interaction with calcineurin, in cardiomyocytes and breast cancer cells. However, the functional significance of the PMCA/calcineurin interaction in endothelial pathophysiology has not been addressed thus far. APPROACH AND RESULTS: Using in vitro and in vivo assays, we here demonstrate that the interaction between PMCA4 and calcineurin in VEGF-stimulated endothelial cells leads to downregulation of the calcineurin/NFAT pathway and to a significant reduction in the subsequent expression of the NFAT-dependent, VEGF-activated, proangiogenic genes RCAN1.4 and Cox-2. PMCA4-dependent inhibition of calcineurin signaling translates into a reduction in endothelial cell motility and blood vessel formation that ultimately impairs in vivo angiogenesis by VEGF. CONCLUSIONS: Given the importance of the calcineurin/NFAT pathway in the regulation of pathological angiogenesis, targeted modulation of PMCA4 functionality might open novel therapeutic avenues to promote or attenuate new vessel formation in diseases that occur with angiogenesis.


Assuntos
Indutores da Angiogênese/farmacologia , Calcineurina/metabolismo , ATPases Transportadoras de Cálcio/metabolismo , Células Endoteliais/efeitos dos fármacos , Músculo Esquelético/irrigação sanguínea , Neovascularização Fisiológica/efeitos dos fármacos , ATPases Transportadoras de Cálcio da Membrana Plasmática/metabolismo , Fator A de Crescimento do Endotélio Vascular/farmacologia , Animais , Proteínas de Ligação ao Cálcio , ATPases Transportadoras de Cálcio/deficiência , ATPases Transportadoras de Cálcio/genética , Movimento Celular , Proliferação de Células , Ciclo-Oxigenase 2/metabolismo , Proteínas de Ligação a DNA , Modelos Animais de Doenças , Células Endoteliais/enzimologia , Células HEK293 , Membro Posterior , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/enzimologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Isquemia/enzimologia , Isquemia/fisiopatologia , Camundongos , Camundongos Knockout , Proteínas Musculares/metabolismo , Fatores de Transcrição NFATC/genética , Fatores de Transcrição NFATC/metabolismo , ATPases Transportadoras de Cálcio da Membrana Plasmática/genética , Interferência de RNA , Transdução de Sinais , Fatores de Tempo , Transfecção
10.
J Biol Chem ; 287(14): 11516-25, 2012 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-22334691

RESUMO

The control of cellular water flow is mediated by the aquaporin (AQP) family of membrane proteins. The structural features of the family and the mechanism of selective water passage through the AQP pore are established, but there remains a gap in our knowledge of how water transport is regulated. Two broad possibilities exist. One is controlling the passage of water through the AQP pore, but this only has been observed as a phenomenon in some plant and microbial AQPs. An alternative is controlling the number of AQPs in the cell membrane. Here, we describe a novel pathway in mammalian cells whereby a hypotonic stimulus directly induces intracellular calcium elevations through transient receptor potential channels, which trigger AQP1 translocation. This translocation, which has a direct role in cell volume regulation, occurs within 30 s and is dependent on calmodulin activation and phosphorylation of AQP1 at two threonine residues by protein kinase C. This direct mechanism provides a rationale for the changes in water transport that are required in response to constantly changing local cellular water availability. Moreover, because calcium is a pluripotent and ubiquitous second messenger in biological systems, the discovery of its role in the regulation of AQP translocation has ramifications for diverse physiological and pathophysiological processes, as well as providing an explanation for the rapid regulation of water flow that is necessary for cell homeostasis.


Assuntos
Aquaporina 1/metabolismo , Espaço Intracelular/metabolismo , Osmose , Água/metabolismo , Animais , Astrócitos/citologia , Astrócitos/metabolismo , Cálcio/metabolismo , Calmodulina/metabolismo , Tamanho Celular , Células HEK293 , Homeostase , Humanos , Cinética , Fosforilação , Proteína Quinase C/química , Proteína Quinase C/metabolismo , Transporte Proteico , Ratos , Canais de Cátion TRPC/antagonistas & inibidores , Canais de Cátion TRPC/metabolismo
11.
bioRxiv ; 2023 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-37649909

RESUMO

One limitation on the ability to monitor health in older adults using Magnetic Resonance (MR) imaging is the presence of implants, where the prevalence of implantable devices (orthopedic, cardiac, neuromodulation) increases in the population, as does the pervasiveness of conditions requiring MRI studies for diagnosis (musculoskeletal diseases, infections, or cancer). The present study describes a novel multiphysics implant modeling testbed using the following approaches with two examples: - an in-silico human model based on the widely available Visible Human Project (VHP) cryo-section dataset; - a finite element method (FEM) modeling software workbench from Ansys (Electronics Desktop/Mechanical) to model MR radio frequency (RF) coils and the temperature rise modeling in heterogeneous media. The in-silico VHP Female model (250 parts with an additional 40 components specifically characterizing embedded implants and resultant surrounding tissues) corresponds to a 60-year-old female with a body mass index (BMI) of 36. The testbed includes the FEM-compatible in-silico human model, an implant embedding procedure, a generic parameterizable MRI RF birdcage two-port coil model, a workflow for computing heat sources on the implant surface and in adjacent tissues, and a thermal FEM solver directly linked to the MR coil simulator to determine implant heating based on an MR imaging study protocol. The primary target is MR labeling of large orthopaedic implants. The testbed has very recently been approved by the US Food and Drug Administration (FDA) as a medical device development tool (MDDT) for 1.5 T orthopaedic implant examinations.

12.
Carcinogenesis ; 33(12): 2362-8, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22962307

RESUMO

Cancer is caused by defects in the signalling mechanisms that govern cell proliferation and apoptosis. It is well known that calcium-dependent signalling pathways play a critical role in cell regulation. A tight control of calcium homeostasis by transporters and channel proteins is required to assure a proper functioning of the calcium-sensitive signal transduction pathways that regulate cell growth and apoptosis. The plasma membrane calcium ATPase 2 (PMCA2) has been recently identified as a negative regulator of apoptosis that can play a significant role in cancer progression by conferring cells resistance to apoptosis. We have previously reported an inhibitory interaction between PMCA2 and the calcium-activated signalling molecule calcineurin in breast cancer cells. Here, we demonstrate that disruption of the PMCA2/calcineurin interaction in a variety of human breast cancer cells results in activation of the calcineurin/NFAT pathway, upregulation in the expression of the pro-apoptotic protein Fas Ligand and in a concomitant loss of cell viability. Reduction in cell viability is the consequence of an increase in cell apoptosis. Impairment of the PMCA2/calcineurin interaction enhances paclitaxel-mediated cytotoxicity of breast tumoral cells. Our results suggest that therapeutic modulation of the PMCA2/calcineurin interaction might have important clinical applications to improve current treatments for breast cancer patients.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Calcineurina/fisiologia , Paclitaxel/farmacologia , ATPases Transportadoras de Cálcio da Membrana Plasmática/fisiologia , Linhagem Celular Tumoral , Proteína Ligante Fas/análise , Genes p53 , Humanos , Fatores de Transcrição NFATC/fisiologia , Ligação Proteica/efeitos dos fármacos , Transdução de Sinais
13.
Biochim Biophys Acta ; 1813(5): 802-9, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21334384

RESUMO

Adiponectin is an abundantly circulating adipokine, orchestrating its effects through two 7-transmembrane receptors (AdipoR1 and AdipoR2). Steroidogenesis is regulated by a variety of neuropeptides and adipokines. Earlier studies have reported adipokine mediated steroid production. A key rate-limiting step in steroidogenesis is cholesterol transportation across the mitochondrial membrane by steroidogenic acute regulatory protein (StAR). Several signalling pathways regulate StAR expression. The actions of adiponectin and its role in human adrenocortical steroid biosynthesis are not fully understood. The aim of this study was to investigate the effects of adiponectin on StAR protein expression, steroidogenic genes, and cortisol production and to dissect the signalling cascades involved in the activation of StAR expression. Using qRT-PCR, Western blot analysis and ELISA, we have demonstrated that stimulation of human adrenocortical H295R cells with adiponectin results in increased cortisol secretion. This effect is accompanied by increased expression of key steroidogenic pathway genes including StAR protein expression via ERK1/2 and AMPK-dependent pathways. This has implications for our understanding of adiponectin receptor activation and peripheral steroidogenesis. Finally, our study aims to emphasise the key role of adipokines in the integration of metabolic activity and energy balance partly via the regulation of adrenal steroid production. This article is part of a Special Issue entitled: 11th European Symposium on Calcium.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Adiponectina/farmacologia , Córtex Suprarrenal/citologia , Córtex Suprarrenal/enzimologia , Hidrocortisona/biossíntese , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Fosfoproteínas/metabolismo , Adiponectina/metabolismo , Apoptose/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Hidrocortisona/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Fosfoproteínas/genética , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Adiponectina/genética , Receptores de Adiponectina/metabolismo , Fatores de Tempo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
14.
Int J Biochem Cell Biol ; 143: 106135, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34896612

RESUMO

Epidemiological studies show that higher circulating levels of odd chain saturated fatty acids (FA: C15:0 and C17:0) are associated with lower risk of metabolic disease. These odd chain saturated fatty acids (OCSFA) are produced by α-oxidation in peroxisomes, de novo lipogenesis, from the diet and by gut microbiota. Although present at low concentrations, they are of interest as potential targets to reduce metabolic disease risk. To determine whether OCSFA are affected by obesogenic diets, we have investigated whether high dietary fat intake affects the frequency of OCSFA-producing gut microbiota, liver lipid metabolism genes and circulating OCSFA. FA concentrations were determined in liver and serum from pathogen-free SPF C57BL/6 J mice fed either standard chow or a high fat diet (HFD; 60% calories as fat) for four and twelve weeks. Post-mortem mouse livers were analysed histologically for fat deposition by gas chromatography-mass spectrometry for FA composition and by qPCR for the lipid metabolic genes fatty acid desaturase 2 (FADS2), stearoyl CoA desaturase 1 (SCD1), elongation of long-chain fatty acids family member 6 (ELOVL6) and 2-hydroxyacyl-CoA lyase 1 (HACL). Gut microbiota in faecal pellets from the ileum were analysed by 16S RNA sequencing. A significant depletion of serum and liver C15:0 (>50%; P < 0.05) and liver C17:0 (>35%; P < 0.05) was observed in HFD-fed SPF mice in parallel with hepatic fat accumulation after four weeks. In addition, liver gene expression (HACL1, ELOVL6, SCD1 and FADS2) was lower (>50%; P < 0.05) and the relative abundance of beneficial C3:0-producing gut bacteria such as Akkermansia, Lactobacillus, Bifidobacterium was lower after HFD in SPF mice. In summary, high dietary fat intake reduces serum and liver OCSFA, OCSFA-producing gut microbiota and is associated with impaired liver lipid metabolism. Further studies are required to identify whether there is any beneficial effect of OCSFA and C3:0-producing gut bacteria to counter metabolic disease.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Ácidos Graxos/metabolismo , Animais , Masculino , Camundongos
15.
Med Sci (Basel) ; 10(4)2022 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-36278523

RESUMO

BACKGROUND: Guidelines for the management of polycystic ovary syndrome (PCOS) focus on lifestyle changes, incorporating exercise. Whilst evidence suggests that aerobic exercise may be beneficial, less is known about the effectiveness of resistance training (RT), which may be more feasible for those that have low fitness levels and/or are unable to tolerate/participate in aerobic exercise. OBJECTIVES: To identify the available evidence on RT in women with PCOS and to summarise findings in the context of a scoping review. ELIGIBILITY CRITERIA: Studies utilising pre-post designs to assess the effectiveness of RT in PCOS; all outcomes were included. SOURCES OF EVIDENCE: Four databases (PubMed, CENTRAL, CINAHL and SportDiscus) were searched and supplemented by hand searching of relevant papers/reference lists. CHARTING METHODS: Extracted data were presented in tables and qualitatively synthesised. RESULTS: Searches returned 42 papers; of those, 12 papers were included, relating to six studies/trials. Statistical changes were reported for multiple pertinent outcomes relating to metabolic (i.e., glycaemia and fat-free mass) and hormonal (i.e., testosterone and sex hormone-binding globulin) profiles. CONCLUSIONS: There is a striking lack of studies in this field and, despite the reported statistical significance for many outcomes, the documented magnitude of changes are small and the quality of the evidence questionable. This highlights an unmet need for rigorously designed/reported and sufficiently powered trials.


Assuntos
Síndrome do Ovário Policístico , Treinamento Resistido , Humanos , Feminino , Síndrome do Ovário Policístico/terapia , Globulina de Ligação a Hormônio Sexual , Estilo de Vida , Testosterona
17.
Nat Rev Endocrinol ; 17(9): 534-548, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34172940

RESUMO

The past 50 years have seen a growing ageing population with an increasing prevalence of type 2 diabetes mellitus (T2DM); now, nearly half of all individuals with diabetes mellitus are older adults (aged ≥65 years). Older adults with T2DM present particularly difficult challenges. For example, the accentuated heterogeneity of these patients, the potential presence of multiple comorbidities, the increased susceptibility to hypoglycaemia, the increased dependence on care and the effect of frailty all add to the complexity of managing diabetes mellitus in this age group. In this Review, we offer an update on the key pathophysiological mechanisms associated with T2DM in older people. We then evaluate new evidence relating particularly to the effects of frailty and sarcopenia, the clinical difficulties of age-associated comorbidities, and the implications for existing guidelines and therapeutic options. Our conclusions will focus on the effect of T2DM on an ageing society.


Assuntos
Envelhecimento/fisiologia , Diabetes Mellitus Tipo 2/terapia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiologia , Fragilidade/complicações , Fragilidade/epidemiologia , Fragilidade/terapia , Humanos , Prevalência , Sarcopenia/complicações , Sarcopenia/epidemiologia , Sarcopenia/terapia
18.
Cytokine Growth Factor Rev ; 60: 120-132, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34108103

RESUMO

White adipose tissue is a dynamic endocrine organ that releases an array of adipokines, which play a key role in regulating metabolic homeostasis and multiple other physiological processes. An altered adipokine secretion profile from adipose tissue depots frequently characterizes obesity and related cardio-metabolic diseases. Asprosin is a recently discovered adipokine that is released in response to fasting. Following secretion, asprosin acts - via an olfactory G-protein coupled receptor and potentially via other unknown receptor(s) - on hepatocytes and agouti-related peptide-expressing neurons in the central nervous system to stimulate glucose secretion and promote appetite, respectively. A growing body of both in vitro and in vivo studies have shown asprosin to exert a number of effects on different metabolic tissues. Indeed, asprosin can attenuate insulin signalling and promote insulin resistance in skeletal muscle by increasing inflammation and endoplasmic reticulum stress. Interestingly, asprosin may also play a protective role in cardiomyocytes that are exposed to hypoxic conditions. Moreover, clinical studies have reported elevated circulating asprosin levels in obesity, type 2 diabetes and other obesity-related cardio-metabolic diseases, with significant associations to clinically relevant parameters. Understanding the spectrum of the effects of this novel adipokine is essential in order to determine its physiologic role and its significance as a potential therapeutic target and/or a biomarker of cardio-metabolic disease. The present review offers a comprehensive overview of the published literature on asprosin, including both clinical and preclinical studies, focusing on its role in metabolism and cardio-metabolic disease.


Assuntos
Doenças Cardiovasculares/etiologia , Doenças Metabólicas , Obesidade , Adipocinas , Jejum , Fibrilina-1 , Humanos , Doenças Metabólicas/etiologia , Proteínas dos Microfilamentos , Obesidade/complicações , Fragmentos de Peptídeos , Hormônios Peptídicos
19.
Front Glob Womens Health ; 2: 649104, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34816205

RESUMO

Background: Lockdown measures have been enforced globally in response to the COVID-19 pandemic. Given the comorbidity burden in women with polycystic ovary syndrome (PCOS), these lockdown measures may have a particularly negative impact on sleep health, quality of life (QoL), and depression/stress levels in this population. The aim of this study was to explore whether such potential problems were present in women with PCOS during the COVID-19 lockdown in the UK. Methods: UK women with PCOS were recruited through social media into a cross-sectional study during the COVID-19 lockdown. The study survey was delivered online, and included demographic and COVID-19 relevant questions, as well as validated questionnaires/scales, namely the Insomnia Severity Index (ISI), Depression Anxiety and Stress Scale (DASS-21), and PCOSQOL questionnaire. Results: Three hundred and thirty-three women with PCOS [median age: 30.0 (9.0) years] were recruited. Participants were dichotomized based on responses regarding the impact of COVID-19 restrictions on their sleep [negative (N = 242) vs. no/positive (N = 91) impact]. No differences were noted between groups regarding age, time since PCOS diagnosis, body mass index, or number of comorbidities. Based on the ISI, 44.2% of participants reporting a negative impact on sleep exhibited at least moderately severe clinical insomnia. Compared to those who reported no/positive effect on sleep, the participants reporting a negative impact on sleep also reported poorer QoL, based on the total PCOSQOL score, with a greater impact of PCOS and poorer mood in the corresponding PCOSQOL domains. Based on the DASS-21, the latter also had statistically higher depression and stress levels compared to the former. Finally, for this cohort significant inverse correlations were noted between the ISI and PCOSQOL scores (total and domain scores), whilst the DASS-21 and ISI scores were positively correlated (all p-values <0.001). Conclusion: The majority of recruited UK women with PCOS reported that the COVID-19 lockdown had a negative impact on their sleep, which was also associated with impaired QoL and higher depression/stress levels. Whilst further research is required, women with PCOS should be considered a vulnerable population that may experience an adverse impact on sleep, QoL and mental health well-being due to lockdown measures during the COVID-19 pandemic.

20.
Biochemistry ; 49(5): 821-3, 2010 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-20063900

RESUMO

It is well-known that the rapid flow of water into and out of cells is controlled by membrane proteins called aquaporins (AQPs). However, the mechanisms that allow cells to quickly respond to a changing osmotic environment are less well established. Using GFP-AQP fusion proteins expressed in HEK293 cells, we demonstrate the reversible manipulation of cellular trafficking of AQP1. AQP1 trafficking was mediated by the tonicity of the cell environment in a specific PKC- and microtubule-dependent manner. This suggests that the increased level of water transport following osmotic change may be due a phosphorylation-dependent increase in the level of AQP1 trafficking resulting in membrane localization.


Assuntos
Aquaporina 1/metabolismo , Membrana Celular/metabolismo , Microtúbulos/enzimologia , Proteína Quinase C/fisiologia , Aquaporina 1/genética , Linhagem Celular , Membrana Celular/enzimologia , Membrana Celular/genética , Proteínas de Fluorescência Verde/genética , Humanos , Proteínas de Fusão de Membrana/genética , Proteínas de Fusão de Membrana/metabolismo , Microtúbulos/genética , Microtúbulos/metabolismo , Pressão Osmótica/fisiologia , Transporte Proteico/genética , Transporte Proteico/fisiologia , Água/metabolismo
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