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1.
Toxicol In Vitro ; 92: 105660, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37591407

RESUMO

Airway remodelling occurs in chronic respiratory diseases (CRDs) such as asthma and chronic obstructive pulmonary disease (COPD). It is characterized by aberrant activation of epithelial reparation, excessive extracellular matrix (ECM) deposition, epithelial-to-mesenchymal transition (EMT), and airway obstruction. The master regulator is Transforming Growth Factor-ß (TGF-ß), which activates tissue repair, release of growth factors, EMT, increased cell proliferation, and reduced nitric oxide (NO) secretion. Due to its fundamental role in remodelling, TGF-ß is an emerging target in the treatment of CRDs. Berberine is a benzylisoquinoline alkaloid with antioxidant, anti-inflammatory, and anti-fibrotic activities whose clinical application is hampered by poor permeability. To overcome these limitations, in this study, berberine was encapsulated in monoolein-based liquid crystalline nanoparticles (BM-LCNs). The potential of BM-LCNs in inhibiting TGF-ß-induced remodelling features in human bronchial epithelial cells (BEAS-2B) was tested. BM-LCNs significantly inhibited TGF-ß-induced migration, reducing the levels of proteins upregulated by TGF-ß including endoglin, thrombospondin-1, basic fibroblast growth factor, vascular-endothelial growth factor, and myeloperoxidase, and increasing the levels of cystatin C, a protein whose expression was downregulated by TGF-ß. Furthermore, BM-LCNs restored baseline NO levels downregulated by TGF-ß. The results prove the in vitro therapeutic efficacy of BM-LCNs in counteracting TGF-ß-induced remodelling features. This study supports the suitability of berberine-loaded drug delivery systems to counteract airway remodelling, with potential application as a treatment strategy against CRDs.


Assuntos
Berberina , Humanos , Berberina/farmacologia , Remodelação das Vias Aéreas , Antioxidantes , Proliferação de Células , Células Epiteliais
2.
Antioxidants (Basel) ; 11(5)2022 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-35624737

RESUMO

Cigarette smoke is considered a primary risk factor for chronic obstructive pulmonary disease. Numerous toxicants present in cigarette smoke are known to induce oxidative stress and airway inflammation that further exacerbate disease progression. Generally, the broncho-epithelial cells and alveolar macrophages exposed to cigarette smoke release massive amounts of oxidative stress and inflammation mediators. Chronic exposure of cigarette smoke leads to premature senescence of airway epithelial cells. This impairs cellular function and ultimately leads to the progression of chronic lung diseases. Therefore, an ideal therapeutic candidate should prevent disease progression by controlling oxidative stress, inflammation, and senescence during the initial stage of damage. In our study, we explored if berberine (an alkaloid)-loaded liquid crystalline nanoparticles (berberine-LCNs)-based treatment to human broncho-epithelial cells and macrophage inhibits oxidative stress, inflammation, and senescence induced by cigarette-smoke extract. The developed berberine-LCNs were found to have favourable physiochemical parameters, such as high entrapment efficiency and sustained in vitro release. The cellular-assay observations revealed that berberine-LCNs showed potent antioxidant activity by suppressing the generation of reactive oxygen species in both broncho-epithelial cells (16HBE) and macrophages (RAW264.7), and modulating the genes involved in inflammation and oxidative stress. Similarly, in 16HBE cells, berberine-LCNs inhibited the cigarette smoke-induced senescence as revealed by X-gal staining, gene expression of CDKN1A (p21), and immunofluorescent staining of p21. Further in-depth mechanistic investigations into antioxidative, anti-inflammatory, and antisenescence research will diversify the current findings of berberine as a promising therapeutic approach for inflammatory lung diseases caused by cigarette smoking.

3.
Front Pharmacol ; 13: 857864, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35450034

RESUMO

Background: Polysaccharide peptide (PSP) extract of Coriolus versicolor (L.) Quél. (1886) (Trametes; Polyporaceae) is increasingly used in cancer to support the immune system. However, its interaction with tamoxifen is unknown. Aim of the study: To investigate the effect of a PSP extract on the pharmacokinetics, biochemical parameters, and depletion of tamoxifen. Methods: The pharmacokinetic and biochemical parameters of tamoxifen (20 mg/mL oral single dose and repeated dosing for 12 days) was investigated in female Sprague Dawley rats with or without PSP (340 mg/kg orally for 7 days) (n = 5 per group). Tamoxifen (5 µM) depletion rate with PSP (10-100 µg/mL) was measured in female rat hepatic microsomes in vitro. Results: Compared to tamoxifen alone, the time to reach maximum concentration (Tmax) significantly increased by 228% (4.15 ± 1.15 versus 13.6 ± 2.71 h) in the single tamoxifen dose with PSP and 93% (6 ± 2.17 versus 11.6 ± 0.4 h) in the repeated tamoxifen dosing with PSP (p < 0.05). No significant changes in the area-under-curve and maximum concentration were observed in the single dose and repeated tamoxifen dosing plus PSP compared to tamoxifen alone. Pharmacodynamically, the repeated tamoxifen dosing with PSP maintained 19 out of 23 hepatic, renal and cardiac biochemical serum parameters in rats compared to untreated rats (p > 0.05). PSP extract did not significantly alter in vitro intrinsic clearance of tamoxifen compared to tamoxifen control. Conclusion: With the increased use of PSP as an adjunct therapy, this study highlights the importance of clinician's knowledge of its interaction with tamoxifen to avoid compromising clinical actions and enhancing clinical therapy.

4.
Curr Mol Pharmacol ; 14(3): 321-332, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33494692

RESUMO

Hypoxia is an integral part of the tumor microenvironment, caused primarily due to rapidly multiplying tumor cells and a lack of proper blood supply. Among the major hypoxic pathways, HIF-1 transcription factor activation is one of the widely investigated pathways in the hypoxic tumor microenvironment (TME). HIF-1 is known to activate several adaptive reactions in response to oxygen deficiency in tumor cells. HIF-1 has two subunits, HIF-1ß (constitutive) and HIF-1α (inducible). The HIF-1α expression is largely regulated via various cytokines (through PI3K-ACT-mTOR signals), which involves the cascading of several growth factors and oncogenic cascades. These events lead to the loss of cellular tumor suppressant activity through changes in the level of oxygen via oxygen-dependent and oxygen-independent pathways. The significant and crucial role of HIF in cancer progression and its underlying mechanisms have gained much attention lately among the translational researchers in the fields of cancer and biological sciences, which have enabled them to correlate these mechanisms with various other disease modalities. In the present review, we have summarized the key findings related to the role of HIF in the progression of tumors.


Assuntos
Translocador Nuclear Receptor Aril Hidrocarboneto , Subunidade alfa do Fator 1 Induzível por Hipóxia , Neoplasias , Translocador Nuclear Receptor Aril Hidrocarboneto/metabolismo , Hipóxia Celular/fisiologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias/patologia , Oxigênio/metabolismo , Microambiente Tumoral
5.
J Environ Pathol Toxicol Oncol ; 38(3): 205-216, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31679308

RESUMO

Artemisia vulgaris is a traditional Chinese herb believed to have a wide range of healing properties; it is traditionally used to treat numerous health ailments. The plant is commonly called mugwort or riverside wormwood. The plant is edible, and in addition to its medicinal properties, it is also used as a culinary herb in Asian cooking in the form of a vegetable or in soup. The plant has garnered the attention of researchers in the past few decades, and several research studies have investigated its biological effects, including antioxidant, anti-inflammatory, anticancer, hypolipidemic, and antimicrobial properties. In this review, various studies on these biological effects are discussed along with the tests conducted, compounds involved, and proposed mechanisms of action. This review will be of interest to the researchers working in the field of herbal medicine, pharmacology, medical sciences, and immunology.


Assuntos
Artemisia/química , Fitoterapia , Extratos Vegetais/farmacologia , Anti-Infecciosos/farmacologia , Anti-Inflamatórios/farmacologia , Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Hipolipemiantes/farmacologia , Plantas Medicinais/química
6.
Curr Diab Rep ; 19(5): 22, 2019 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-30905013

RESUMO

PURPOSE OF REVIEW: Type 1 diabetes (T1D) occurs when there is destruction of beta cells within the islets of Langerhans in the pancreas due to autoimmunity. It is considered a complex disease, and different complications can surface and worsen the condition if T1D is not managed well. Since it is an incurable disease, numerous treatments and therapies have been postulated in order to control T1D by balancing hyperglycemia control while minimizing hypoglycemic episodes. The purpose of this review is to primarily look into the current state of the available immunological therapies and their advantages for the treatment of T1D. RECENT FINDINGS: Over the years, immunological therapy has become the center of attraction to treat T1D. Immunomodulatory approaches on non-antigens involving agents such as cyclosporine A, mycophenolate mofetil, anti-CD20, cytotoxic T cells, anti-TNF, anti-CD3, and anti-thymocyte globulin as well as immunomodulative approaches on antigens such as insulin, glutamic acid decarboxylase, and heat shock protein 60 have been studied. Aside from these two approaches, studies and trials have also been conducted on regulatory T cells, dendritic cells, interleukin 2, interleukin 4, M2 macrophages, and rapamycin/interleukin 2 combination therapy to test their effects on patients with T1D. Many of these agents have successfully suppressed T1D in non-obese diabetic (NOD) mice and in human trials. However, some have shown negative results. To date, the insights into the management of the immune system have been increasing rapidly to search for potential therapies and treatments for T1D. Nevertheless, some of the challenges are still inevitable. A lot of work and effort need to be put into the investigation on T1D through immunological therapy, particularly to reduce complications to improve and enhance clinical outcomes.


Assuntos
Diabetes Mellitus Tipo 1 , Animais , Humanos , Imunoterapia , Insulina , Camundongos Endogâmicos NOD , Fator de Necrose Tumoral alfa
7.
Biomed Pharmacother ; 108: 1188-1200, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30372820

RESUMO

BACKGROUND: Type 1 diabetes mellitus (T1DM) is an autoimmune disorder characterized by T cell-mediated self-destruction of insulin-secreting islet ß cells. Management of T1DM is challenging and complicated especially with conventional medications. Gene therapy has emerged as one of the potential therapeutic alternatives to treat T1DM. This review primarily focuses on the current status and the future perspectives of gene therapy in the management of T1DM. A vast number of the studies which are reported on gene therapy for the management of T1DM are done in animal models and in preclinical studies. In addition, the safety of such therapies is yet to be established in humans. Currently, there are several gene level interventions that are being investigated, notably, overexpression of genes and proteins needed against T1DM, transplantation of cells that express the genes against T1DM, stem-cells mediated gene therapy, genetic vaccination, immunological precursor cell-mediated gene therapy and vectors. METHODS: We searched the current literature through searchable online databases, journals and other library sources using relevant keywords and search parameters. Only relevant publications in English, between the years 2000 and 2018, with evidences and proper citations, were considered. The publications were then analyzed and segregated into several subtopics based on common words and content. A total of 126 studies were found suitable for this review. FINDINGS: Generally, the pros and cons of each of the gene-based therapies have been discussed based on the results collected from the literature. However, there are certain interventions that require further detailed studies to ensure their effectiveness. We have also highlighted the future direction and perspectives in gene therapy, which, researchers could benefit from.


Assuntos
Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/terapia , Terapia Genética , Animais , Ensaios Clínicos como Assunto , Diabetes Mellitus Tipo 1/prevenção & controle , Engenharia Genética , Humanos , Imunoterapia , Vacinação
8.
J Sci Food Agric ; 98(13): 4793-4806, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29656381

RESUMO

Cowpea (Vigna unguiculata) is a legume consumed as a high-quality plant protein source in many parts of the world. High protein and carbohydrate contents with a relatively low fat content and a complementary amino acid pattern to that of cereal grains make cowpea an important nutritional food in the human diet. Cowpea has gained more attention recently from consumers and researchers worldwide as a result of its exerted health beneficial properties, including anti-diabetic, anti-cancer, anti-hyperlipidemic, anti-inflammatory and anti-hypertensive properties. Among the mechanisms that have been proposed in the prevention of chronic diseases, the most proven are attributed to the presence of compounds such as soluble and insoluble dietary fiber, phytochemicals, and proteins and peptides in cowpea. However, studies on the anti-cancer and anti-inflammatory properties of cowpea have produced conflicting results. Some studies support a protective effect of cowpea on the progression of cancer and inflammation, whereas others did not reveal any. Because there are only a few studies addressing health-related effects of cowpea consumption, further studies in this area are suggested. In addition, despite the reported favorable effects of cowpea on diabetes, hyperlipidemia and hypertension, a long-term epidemiological study investigating the association between cowpea consumption and diabetes, cardiovascular disease and cancer is also recommended. © 2018 Society of Chemical Industry.


Assuntos
Vigna/química , Vigna/metabolismo , Animais , Dieta Saudável , Humanos , Valor Nutritivo , Compostos Fitoquímicos/química , Compostos Fitoquímicos/metabolismo , Sementes/metabolismo
9.
PLoS One ; 11(1): e0146881, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26799072

RESUMO

Polysaccharopeptide (PSP), from Coriolus versicolor, has been used widely as an adjuvant to chemotherapy with demonstrated anti-tumor and broad immunomodulating effects. While PSP's mechanism of action still remains unknown, its enhanced immunomodulatory potential with acacia gum is of great interest. Acacia gum, which also contains polysaccharides and glycoproteins, has been demonstrated to be immunopotentiating. To elucidate whether PSP directly activates T-cell-dependent B-cell responses in vivo, we used a well-established hapten carrier system (Nitrophenyl-chicken gamma globulin (NP-CGG)). 6-week C57BL/6 male mice were immunised with 50 µg of NP25-CGG alum precipitate intraperitoneally. Mice were gavaged daily with 50 mg/kg PSP in a vehicle containing acacia gum and sacrificed at days 0, 4, 7, 10, 14 and 21. ELISA was used to measure the total and relative hapten-specific anti-NP IgA, IgM and IgG titre levels compared to the controls. It was found that PSP, combined with acacia gum, significantly increased total IgG titre levels at day 4 (P< 0.05), decreased IgM titre levels at days 4 and 21 (P< 0.05) with no alterations observed in the IgA or IgE titre levels at any of the time points measured. Our results suggest that while PSP combined with acacia gum appears to exert weak immunological effects through specific T-cell dependent B-cell responses, they are likely to be broad and non-specific which supports the current literature on PSP. We report for the first time the application of a well-established hapten-carrier system that can be used to characterise and delineate specific T-cell dependent B-cell responses of potential immunomodulatory glycoprotein-based herbal medicines combinations in vivo.


Assuntos
Anticorpos/sangue , Linfócitos B/imunologia , Goma Arábica/farmacologia , Proteoglicanas/imunologia , Linfócitos T/imunologia , gama-Globinas/imunologia , Adjuvantes Imunológicos/farmacologia , Animais , Anticorpos/imunologia , Haptenos/imunologia , Imunização , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Imunoterapia/métodos , Ativação Linfocitária/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias/terapia , Nitrofenóis/imunologia , Fenilacetatos/imunologia , Proteoglicanas/farmacologia , Trametes/imunologia
10.
J Pharm Pharm Sci ; 18(4): 424-33, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26626244

RESUMO

PURPOSE: Circulating microparticles have been highlighted as biomarkers of cardiovascular disease state and progression. The aim of this study was to evaluate the effects of curcumin on microparticle release from endothelial cells undergoing TNF-induced cell activation and apoptosis. METHODS: This study evaluated the effects of curcumin on microparticle release, cytotoxicity, apoptosis, cell adhesion molecule expression and monocyte adhesion in EAhy926 human endothelial cells. RESULTS: The results showed that the numbers of microparticles were increased by tumour necrosis factor (TNF) or the combination of TNF and cycloheximide (CHX). Curcumin attenuated microparticle release caused by TNF or TNF plus CHX treatments. The pretreatment by curcumin not only negated the accelerated cell death and apoptosis caused by TNF and CHX, but also diminished TNF-induced cell activation, as assessed by reduced surface expression of intercellular adhesion molecule 1, and adhesion of monocytes to endothelial monolayers. CONCLUSION: Curcumin reduced microparticle release from endothelial cells undergoing cell activation and apoptosis, which supports its protective role in TNF-associated endothelial dysfunction, and highlights its potential use as a nutraceutical agent for vascular inflammatory diseases. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.


Assuntos
Micropartículas Derivadas de Células/metabolismo , Curcumina/farmacologia , Células Endoteliais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/administração & dosagem , Anexina A5/química , Apoptose/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Moléculas de Adesão Celular/metabolismo , Linhagem Celular , Células Endoteliais/metabolismo , Humanos , Monócitos/efeitos dos fármacos , Monócitos/metabolismo
11.
Int J Cardiol ; 171(2): 231-42, 2014 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-24388544

RESUMO

BACKGROUND: The aim of this study was to investigate the protective effects of gallic acid, a common phenolic compound naturally present in food and nutraceuticals, on endothelial cell death and the mechanisms involved. METHODS: Endothelial cell death was induced by the combination of homocysteine, adenosine and tumour necrosis factor (TNF) in human vascular endothelial cells (EAhy926 and HBEC-5i cells). The protective effects of gallic acid were evaluated against cytotoxicity, apoptosis and microparticle release. Underlying mechanisms were further investigated focusing on the involvement of DNA methyltransferase 1 (DNMT1) and proteasome activities. RESULTS: Our results showed that gallic acid dose-dependently arrested cytotoxicity in EAhy926 and HBEC-5i cells induced by the combination. Gallic acid showed anti-apoptotic effects and reduced the formation of microparticles. Notably, gallic acid reversed DNMT1 depletions at the protein level. The cytoprotective and anti-apoptotic effects of gallic acid were counteracted by the pre-treatment with DNMT1 inhibitor, 5-aza-2-deoxycytidine (5-aza-dC). Treatment with gallic acid led to the accumulation of ubiquitinated protein aggregates and the reduction in chymotrypsin-like proteasome activities indicating proteasome inhibition. CONCLUSION: Our results demonstrate for the first time that gallic acid is capable of protecting endothelial cells from injury induced by the combination of homocysteine, adenosine and TNF, at least in part, by restoring the depletion of DNMT1 and inhibiting proteasome activities.


Assuntos
DNA (Citosina-5-)-Metiltransferases/metabolismo , Células Endoteliais/efeitos dos fármacos , Ácido Gálico/farmacologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteassoma/farmacologia , Adenosina/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Citoproteção/efeitos dos fármacos , DNA (Citosina-5-)-Metiltransferase 1 , Interações Medicamentosas , Células Endoteliais/enzimologia , Células Endoteliais/patologia , Citometria de Fluxo , Homocisteína/toxicidade , Células Endoteliais da Veia Umbilical Humana , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Fator de Necrose Tumoral alfa/toxicidade , Vasodilatadores/toxicidade
12.
J Pharm Pharm Sci ; 16(2): 342-51, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23958203

RESUMO

PURPOSE: Fatty liver disease, a hepatic manifestation of metabolic syndrome, is one of the major causes of chronic liver diseases. Epidemiological studies suggest that regular light-to-moderate ethanol consumption lowers the risk of developing metabolic disorders including dislipidemia, insulin resistance, type 2 diabetes and fatty liver disease. However, the mechanism(s) of the protective effect of light-to-moderate ethanol consumption on the liver remains unknown. METHODS: In the present study, we investigated the effects of light (6%, 0.94 g/kg/day) and moderate (12%, 1.88 g/kg/day) ethanol feeding in rats for 3 weeks on the circulating and hepatic biochemical profiles and on the hepatic protein expression and phosphorylation status of adenosine monophosphate-activated protein kinase-α (AMPK-α) and other down-stream targets of this enzyme including sterol regulatory element-binding protein-1 (SREBP-1), SREBP cleavage-activating protein (SCAP) and 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMG-CoA reductase). RESULTS: Despite no significant difference in food-intake among the groups, light ethanol treatment significantly increased the body weight compared to control rats. Serum glucose, insulin, total cholesterol, triglycerides, phospholipids and hepatic cholesterol and triglycerides were not significantly different among the groups. However, serum free fatty acids were significantly reduced with light ethanol treatment. Both light and moderate ethanol treatment significantly increased the hepatic levels of phosphorylated AMPK-α protein and this was associated with significant reduction of SREBP-1 protein expression, suggesting an enhanced fatty acid oxidation. In addition, light ethanol treatment significantly decreased the SCAP protein expression in the liver. However, liver HMG-CoA protein expression was not significantly different with ethanol consumption. CONCLUSION: Chronic light-to-moderate ethanol consumption increased AMPK activation which was associated with decreased expression of SREBP-1 and SCAP in the liver. Thus, our studies provide mechanistic evidence for the earlier epidemiological studies that indicate light-to-moderate ethanol intake lowers the risk of development of fatty liver disease and other metabolic disorders. Our studies demonstrate that the protective effects of light-to-moderate ethanol arise at least in part by increased phosphorylation of AMPK-α and decreased SREBP-1 expression in the liver. Further studies are warranted to determine the effects of light-to-moderate ethanol on intracellular up-stream and down-stream targets of AMPK and also on the implications of light-to-moderate ethanol in protecting non-alcoholic fatty liver disease.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Etanol/administração & dosagem , Fígado/efeitos dos fármacos , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Hidroximetilglutaril-CoA Redutases/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Fígado/metabolismo , Masculino , Proteínas de Membrana/metabolismo , Ratos , Ratos Sprague-Dawley
13.
Cell Physiol Biochem ; 30(3): 805-14, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22868254

RESUMO

Disruption to the vascular homoeostasis is detrimental in vascular diseases. This study examined how the combination of homocysteine, adenosine and tumor necrosis factor-alpha (TNF-α) influenced endothelial cell survival. In cultured human-derived cardiovascular (EA.hy926) and cerebrovascular (HBEC-5i) endothelial cells, cell death events were initiated by TNF-α (0.1-10 ng/mL) only when both homocysteine (0.5 mM) and adenosine (0.5 mM) were present. The accelerated cell death events induced by the combination were triggered through excessive apoptosis. This was evident by membrane phospholipid phosphatidylserine externalisation, cell shrinkage and DNA fragmentation, as well as an increase in the expressions and occurrence of active caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP) positive cells. Collectively, homocysteine, adenosine and TNF-α are interrelated in the survival of endothelial cells, and this co-existence should be considered in future drug development for cardiovascular and cerebrovascular diseases.


Assuntos
Adenosina/toxicidade , Apoptose/efeitos dos fármacos , Homocisteína/toxicidade , Fator de Necrose Tumoral alfa/toxicidade , Caspase 3/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos da radiação , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Endotélio Vascular/citologia , Humanos , Poli(ADP-Ribose) Polimerases/metabolismo
14.
FASEB J ; 20(13): 2214-22, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17077298

RESUMO

The phosphoinositide-dependent kinase PDK1 activates the serum- and glucocorticoid-inducible kinase isoforms SGK1, SGK2, and SGK3 and protein kinase B, which in turn are known to up-regulate a variety of sodium-coupled transporters. The present study was performed to explore the role of PDK1 in amino acid transport. As mice completely lacking functional PDK1 are not viable, mice expressing 10-25% of PDK1 (pdk1(hm)) were compared with their wild-type (WT) littermates (pdk1(wt)). Body weight was significantly less in pdk1(hm) than in pdk1(wt) mice. Despite lower body weight of pdk1(hm) mice, food and water intake were similar in pdk1(hm) and pdk1(wt) mice. According to Ussing chamber experiments, electrogenic transport of phenylalanine, cysteine, glutamine, proline, leucine, and tryptophan was significantly smaller in jejunum of pdk1(hm) mice than in pdk1(wt) mice. Similarly, electrogenic transport of phenylalanine, glutamine, and proline was significantly decreased in isolated perfused proximal tubules of pdk1(hm) mice. The urinary excretion of proline, valine, guanidinoacetate, methionine, phenylalanine, citrulline, glutamine/glutamate, and tryptophan was significantly larger in pdk1(hm) than in pdk1(wt) mice. According to immunoblotting of brush border membrane proteins prepared from kidney, expression of the Na+-dependent neutral amino acid transporter B(0)AT1 (SLC6A19), the glutamate transporter EAAC1/EAAT3 (SLC1A1), and the transporter for cationic amino acids and cystine b(0,+)AT (SLC7A9) was decreased but the Na+/proline cotransporter SIT (SLC6A20) was increased in pdk1(hm) mice. In conclusion, reduction of functional PDK1 leads to impairment of intestinal absorption and renal reabsorption of amino acids. The combined intestinal and renal loss of amino acids may contribute to the growth defect of PDK1-deficient mice.


Assuntos
Aminoácidos/metabolismo , Mucosa Intestinal/embriologia , Jejuno/metabolismo , Túbulos Renais Proximais/metabolismo , Proteínas Serina-Treonina Quinases/deficiência , Proteínas Serina-Treonina Quinases/genética , Proteínas Quinases Dependentes de 3-Fosfoinositídeo , Aminoácidos/sangue , Animais , Capilares/metabolismo , Ingestão de Líquidos , Ingestão de Energia , Técnicas In Vitro , Absorção Intestinal , Mucosa Intestinal/irrigação sanguínea , Camundongos , Camundongos Knockout , Microvilosidades/metabolismo , Circulação Renal
15.
Pflugers Arch ; 451(3): 437-44, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15971077

RESUMO

Xenopus oocyte coexpression experiments revealed the capacity of the serum- and glucocorticoid-inducible kinase isoform 3 (SGK3) to up-regulate a variety of transport systems including the sodium-dependent glucose transporter SGLT1. The present study explored the functional significance of SGK3-dependent regulation of intestinal transport. To this end, experiments were performed in gene targeted mice lacking functional sgk3 (sgk3(-/-)) and their wild type littermates (sgk3(+/+)). Oral food intake and fecal dry weight were significantly larger in sgk3(-/-) than in sgk3(+/+) mice. Glucose-induced current (I(g)) in Ussing chamber as a measure of Na(+) coupled glucose transport was significantly smaller in sgk3(-/-) than in sgk3(+/+) mouse jejunal segments. Fasting plasma glucose concentrations were significantly lower in sgk3(-/-) than in sgk3(+/+) mice. Intestinal electrogenic transport of phenylalanine, cysteine, glutamine and proline were not significantly different between sgk3(-/-) and sgk3(+/+) mice. In conclusion, SGK3 is required for adequate intestinal Na(+) coupled glucose transport and impaired glucose absorption may contribute to delayed growth and decreased plasma glucose concentrations of SGK3 deficient mice. The hypoglycemia might lead to enhanced food intake to compensate for impaired intestinal absorption.


Assuntos
Proteínas Imediatamente Precoces/fisiologia , Absorção Intestinal/fisiologia , Proteínas Serina-Treonina Quinases/fisiologia , Transportador 1 de Glucose-Sódio/fisiologia , Animais , Ingestão de Alimentos , Fezes , Proteínas Imediatamente Precoces/genética , Jejuno/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Serina-Treonina Quinases/genética
16.
Pflugers Arch ; 448(5): 471-7, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15156318

RESUMO

Among the sequelae of phosphate depletion is anaemia, due in part to a decreased life span of mature erythrocytes. Recent studies have disclosed that cellular stress leads to an increase of cytosolic Ca(2+) activity in erythrocytes thereby triggering cell shrinkage and breakdown of phosphatidylserine asymmetry of the cell membrane, both typical features of apoptosis. In the present experiments, phosphatidylserine exposure and cell size were measured by fluorescence-activated cell sorting (FACS) analysis of annexin binding and forward scatter, respectively. Erythrocytes from intact mice were compared with erythrocytes from mice exposed to a low-phosphate diet for 4 days. Annexin binding of freshly drawn erythrocytes was slightly but significantly enhanced by the low-phosphate diet. Furthermore, intracellular phosphate and ATP concentrations were significantly decreased in those erythrocytes whereas intracellular Ca(2+) activity was unaltered. Osmotic shock (exposure to 700 mOsm by addition of sucrose for 12 h), removal of Cl(-) (replaced by gluconate for 15 h) or removal of glucose (12 h) decreased cell volume and increased the number of annexin-binding erythrocytes. Interestingly, these effects were significantly larger in erythrocytes from phosphate-depleted animals. The experiments reveal a novel mechanism triggered by phosphate depletion that presumably contributes to the enhanced vulnerability and accelerated sequestration of erythrocytes and, thus, to anaemia.


Assuntos
Apoptose/fisiologia , Eritrócitos/fisiologia , Fosfatos/deficiência , Trifosfato de Adenosina/análise , Anemia/fisiopatologia , Animais , Anexinas/metabolismo , Tamanho Celular , Eritrócitos/química , Citometria de Fluxo , Líquido Intracelular/química , Masculino , Camundongos , Fosfatos/análise , Fosfatidilserinas/metabolismo , Fósforo na Dieta
17.
Nutr J ; 3: 3, 2004 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-15084221

RESUMO

Obesity is a multi-factorial disorder, which is often associated with many other significant diseases such as diabetes, hypertension and other cardiovascular diseases, osteoarthritis and certain cancers. The management of obesity will therefore require a comprehensive range of strategies focussing on those with existing weight problems and also on those at high risk of developing obesity. Hence, prevention of obesity during childhood should be considered a priority, as there is a risk of persistence to adulthood. This article highlights various preventive aspects and treatment procedures of obesity with special emphasis on the latest research manifolds.

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