Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 45
Filtrar
1.
Br J Haematol ; 204(3): 759-773, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38253961

RESUMO

Iron deficiency (ID) and iron-deficiency anaemia (IDA) are global public health concerns, most commonly afflicting children, pregnant women and women of childbearing age. Pathological outcomes of ID include delayed cognitive development in children, adverse pregnancy outcomes and decreased work capacity in adults. IDA is usually treated by oral iron supplementation, typically using iron salts (e.g. FeSO4 ); however, dosing at several-fold above the RDA may be required due to less efficient absorption. Excess enteral iron causes adverse gastrointestinal side effects, thus reducing compliance, and negatively impacts the gut microbiome. Recent research has sought to identify new iron formulations with better absorption so that lower effective dosing can be utilized. This article outlines emerging research on oral iron supplementation and focuses on molecular mechanisms by which different supplemental forms of iron are transported across the intestinal epithelium and whether these transport pathways are subject to regulation by the iron-regulatory hormone hepcidin.


Assuntos
Anemia Ferropriva , Deficiências de Ferro , Sobrecarga de Ferro , Adulto , Criança , Feminino , Humanos , Gravidez , Ferro/metabolismo , Anemia Ferropriva/terapia , Sobrecarga de Ferro/tratamento farmacológico
2.
Nutr Health ; 27(4): 461-465, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33583247

RESUMO

BACKGROUND: A historical turning point occurred in the treatment of diarrhea when it was discovered that glucose could enhance intestinal sodium and water absorption. Adding glucose to salt water (oral rehydration solution, ORS) more efficiently replaced intestinal water and salt losses. AIM: Provide a novel hypothesis to explain why mainstream use of ORS has been strongly recommended, but weakly adopted. METHODS: Traditional (absorptive) and novel (secretory) physiological functions of glucose in an ORS were reviewed. RESULTS: Small amounts of glucose can stimulate both intestinal absorption and secretion. Glucose can exacerbate a net secretory state and may aggravate pathogen-induced diarrhea, particularly for pathogens that affect glucose transport. CONCLUSION: A hypothesis is made to explain why glucose-based ORS does not appreciably reduce diarrheal stool volume and why modern food science initiatives should focus on ORS formulations that replace water and electrolytes while also reducing stool volume and duration of diarrhea.


Assuntos
Diarreia , Soluções para Reidratação , Diarreia/terapia , Glucose , Humanos , Sódio
3.
J Nutr ; 150(5): 1100-1108, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32133527

RESUMO

BACKGROUND: Radiotherapy inadvertently affects gastrointestinal (GI) epithelial cells, causing intestinal barrier disruption and increased permeability. OBJECTIVE: We examined the effect of amino acid-based oral rehydration solution (AA-ORS) on radiation-induced changes of intestinal barrier function and epithelial tight junctions (TJs) in a randomized experimental study using a total-body irradiation (TBI) mouse model. METHODS: Eight-week-old male Swiss mice received a single-dose TBI (0, 1, 3, or 5 Gy), and subsequent gastric gavage with AA-ORS (threonine, valine, serine, tyrosine, and aspartic acid) or saline for 2 or 6 d. Intestinal barrier function of mouse ileum was characterized by electrophysiological analysis of conductance, anion selectivity, and paracellular permeability [fluorescein isothiocyanate (FITC)-dextran]. Ultrastructural changes of TJs were evaluated by transmission electron microscopy. Membrane protein and mRNA expression of claudin-1, -2, -3, -5, and -7, occludin, and E-cadherin were analyzed with western blot, qPCR, and immunohistochemistry. Nonparametric tests were used to compare treatment-dose differences for each time point. RESULTS: Saline-treated mice had a higher conductance at doses as low as 3 Gy, and as early as 2 d post-TBI compared with 0 Gy (P < 0.001). Paracellular permeability and dilution potential were increased 6 d after 5 Gy TBI (P < 0.001). Conductance decreased with AA-ORS after 2 d in 3-Gy and 5-Gy mice (P < 0.05 and P < 0.001), and on day 6 after 5 Gy TBI (P < 0.001). Anion selectivity and FITC permeability decreased from 0.73 ± 0.02 to 0.61 ± 0.03 pCl/pNa (P < 0.01) and from 2.7 ± 0.1 × 105 to 2.1 ± 0.1 × 105 RFU (P < 0.001) in 5-Gy mice treated with AA-ORS for 6 d compared with saline. Irradiation-induced ultrastructural changes of TJs characterized by decreased electron density and gap formation improved with AA-ORS. Reduced claudin-1, -3, and -7 membrane expression after TBI recovered with AA-ORS within 6 d, whereas claudin-2 decreased indicating restitution of TJ proteins. CONCLUSIONS: Radiation-induced functional and structural disruption of the intestinal barrier in mice is reversed by AA-ORS rendering AA-ORS a potential treatment option in prospective clinical trials in patients with gastrointestinal barrier dysfunction.


Assuntos
Aminoácidos/administração & dosagem , Intestinos/efeitos da radiação , Soluções para Reidratação/química , Soluções para Reidratação/farmacologia , Junções Íntimas/efeitos da radiação , Animais , Hidratação , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos da radiação , Masculino , Camundongos , Permeabilidade , RNA Mensageiro , Proteínas de Junções Íntimas/genética , Proteínas de Junções Íntimas/metabolismo
4.
Mol Ther ; 27(3): 493-506, 2019 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-30713087

RESUMO

Nanoparticles (NPs) have been utilized to deliver drugs to the intestinal epithelium in vivo. Moreover, NPs derived from edible plants are less toxic than synthetic NPs. Here, we utilized ginger NP-derived lipid vectors (GDLVs) in a proof-of-concept investigation to test the hypothesis that inhibiting expression of divalent metal-ion transporter 1 (Dmt1) would attenuate iron loading in a mouse model of hereditary hemochromatosis (HH). Initial experiments using duodenal epithelial organ cultures from intestine-specific Dmt1 knockout (KO) (Dmt1int/int) mice in the Ussing chamber established that Dmt1 is the only active iron importer during iron-deficiency anemia. Further, when Dmt1int/int mice were crossed with mice lacking the iron-regulatory hormone, hepcidin (Hepc-/-), iron loading was abolished. Hence, intestinal Dmt1 is required for the excessive iron absorption that typifies HH. Additional experiments established a protocol to produce GDLVs carrying functional Dmt1 small interfering RNAs (siRNAs) and to target these gene delivery vehicles to the duodenal epithelium in vivo (by incorporating folic acid [FA]). When FA-GDLVs carrying Dmt1 siRNA were administered to weanling Hepc-/- mice for 16 days, intestinal Dmt1 mRNA expression was attenuated and tissue iron accumulation was blunted. Oral delivery of functional siRNAs by FA-GDLVs is a suitable therapeutic approach to mitigate iron loading in murine HH.


Assuntos
Hemocromatose/metabolismo , Hepcidinas/metabolismo , Nanopartículas/química , Fatores de Transcrição/metabolismo , Zingiber officinale , Animais , Feminino , Células HEK293 , Hemocromatose/genética , Hepcidinas/genética , Humanos , Ferro/metabolismo , Ferro da Dieta , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Transcrição/genética
5.
J Nutr ; 148(8): 1244-1252, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30137476

RESUMO

Background: Divalent metal-ion transporter 1 (DMT1) may transport copper, but studies to date on this topic have been equivocal. Previously, an ex vivo experiment showed that intestinal copper transport was impaired in Dmt1-mutant Belgrade rats. Objective: In this study, we tested the hypothesis that intestinal DMT1 transports copper in vivo. Methods: Intestine-specific Dmt1 knockout (Dmt1int/int) mice and normal (control) littermates (Dmt1fl/fl) were used. In study 1, intestinal copper absorption was assessed in 7-wk-old mice of both sexes and genotypes by oral-intragastric gavage of 64Cu under normal and iron-deficiency anemia (IDA) conditions. In study 2, both sexes and genotypes of 8-wk-old mice were fed diets with adequate iron concentrations [72 parts per million (ppm)] plus adequate (9 ppm) or excessive (183 ppm) copper concentrations for 4 wk. Iron- and copper-related physiologic variables were subsequently assessed. Results: Study 1 showed that intestinal copper transport was enhanced in normal (∼11% increase in males, 35% in females) and anemic (∼42% increase in males, 35% in females) Dmt1int/int mice. Study 2 showed that, with adequate copper intakes, serum ceruloplasmin (Cp) activity was decreased (by ∼29% in males and 20% in females) and spleens were enlarged (by 3-fold in both sexes) in Dmt1int/int mice. Higher dietary copper increased hepatic copper concentrations (by ∼3.3-fold in males and 1.5-fold in females), restored serum Cp activity, and mitigated the noted splenomegaly in Dmt1int/int mice. Conclusions: Copper homeostasis was disrupted in Dmt1int/int mice, particularly during IDA, despite the noted increases in intestinal copper transport. This was exemplified by the fact that extra dietary copper was required to restore serum Cp activity (a biomarker of copper status) and reduce the severity of the noted splenomegaly (which could reflect changes in erythropoietic demand) in Dmt1int/int mice. Collectively, these observations show that intestinal DMT1 is essential for the assimilation of sufficient quantities of dietary copper to maintain systemic copper homeostasis during IDA.


Assuntos
Anemia Ferropriva/complicações , Proteínas de Transporte de Cátions/metabolismo , Cobre/farmacocinética , Absorção Intestinal , Intestinos/fisiologia , Deficiências de Ferro , Anemia Ferropriva/metabolismo , Animais , Disponibilidade Biológica , Ceruloplasmina/metabolismo , Cobre/metabolismo , Dieta , Feminino , Homeostase , Íons/metabolismo , Ferro/metabolismo , Fígado/metabolismo , Masculino , Camundongos Knockout , Fatores Sexuais , Esplenomegalia/prevenção & controle
6.
Pflugers Arch ; 469(9): 1093-1105, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28488023

RESUMO

Rotavirus causes severe diarrhea in small children and is typically treated using glucose-containing oral rehydration solutions; however, glucose may have a detrimental impact on these patients, because it increases chloride secretion and presumably water loss. The rotavirus enterotoxin nonstructural protein 4 (NSP4) directly inhibits glucose-mediated sodium absorption. We examined the effects of NSP4 and glucose on sodium and chloride transport in mouse small intestines and Caco-2 cells. Mouse small intestines and Caco-2 cells were incubated with NSP4114-135 in the presence/absence of glucose. Absorption and secretion of sodium and chloride, fluid movement, peak amplitude of intracellular calcium fluorescence, and expression of Ano1 and sodium-glucose cotransporter 1 were assessed. NHE3 activity increased, and chloride secretory activity decreased with age. Net chloride secretion increased, and net sodium absorption decreased in the intestines of 3-week-old mice compared to 8-week-old mice with NSP4. Glucose increased NSP4-stimulated chloride secretion. Glucose increased NSP4-stimulated increase in short-circuit current measurements (I sc) and net chloride secretion. Ano1 cells with siRNA knockdown showed a significant difference in I sc in the presence of NSP4 and glucose without a significant difference in peak calcium fluorescence intracellular when compared to non-silencing (N.S.) cells. The failure of glucose to stimulate significant sodium absorption was likely due to the inhibition of sodium-hydrogen exchange and sodium-glucose cotransport by NSP4. Since glucose enhances intestinal chloride secretion and fails to increase sodium absorption in the presence of NSP4, glucose-based oral rehydration solutions may not be ideal for the management of rotaviral diarrhea.


Assuntos
Enterotoxinas/farmacologia , Glucose/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/fisiologia , Rotavirus/metabolismo , Animais , Anoctamina-1/metabolismo , Transporte Biológico/fisiologia , Células CACO-2 , Cálcio/metabolismo , Linhagem Celular Tumoral , Cloretos/metabolismo , Glicoproteínas/metabolismo , Humanos , Masculino , Camundongos , Sódio/metabolismo , Transportador 1 de Glucose-Sódio/metabolismo , Toxinas Biológicas/metabolismo , Proteínas não Estruturais Virais/metabolismo
7.
Adv Exp Med Biol ; 977: 59-65, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28685428

RESUMO

Nausea and diarrhea are common yet inconsistent side effects of abdominal and pelvic irradiation. Their frequency, chronicity, and severity vary greatly, and the reasons for inter-subject variability are unknown. We studied the potential for radiation-induced changes in amino acid absorption and mucosal barrier function to lead to gastrointestinal toxicity. We found profound and prolonged changes in the absorption and secretion of several electrolytes and nutrients, caused by changes in transporter function, after radiation doses as low as 1 to 3 Gy. After identifying absorbed and non-absorbed amino acids, we demonstrated the role of a beneficial amino acid drink to alleviate radiation-related gastrointestinal symptoms in a mouse model.


Assuntos
Aminoácidos/administração & dosagem , Hidratação/métodos , Náusea/terapia , Pica/terapia , Lesões por Radiação/terapia , Soluções para Reidratação/uso terapêutico , Aminoácidos/farmacocinética , Animais , Modelos Animais de Doenças , Eletrólitos/farmacocinética , Absorção Gastrointestinal , Gastroenteropatias/etiologia , Gastroenteropatias/terapia , Glucose/farmacocinética , Masculino , Camundongos , Náusea/etiologia , Pica/patologia , Lesões por Radiação/complicações , Soluções para Reidratação/química
8.
Bioorg Med Chem ; 24(18): 4263-4271, 2016 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-27448774

RESUMO

In an effort to develop new drug candidates with enhanced anticancer activity, our team synthesized and assessed the cytotoxicity of a series of novel xanthone derivatives with two longer 3,6-disubstituted amine carbonyl methoxy side chains on either benzene ring in selected human cancer cell lines. An MTT assay revealed that a set of compounds with lower IC50 values than the positive control, 5-FU, exhibited greater anticancer effects. The most potent derivative (XD8) exhibited anticancer activity in MDA-MB-231, PC-3, A549, AsPC-1, and HCT116 cells lines with IC50 values of 8.06, 6.18, 4.59, 4.76, and 6.09µM, respectively. Cell cycle analysis and apoptosis activation suggested that the mechanism of action of these derivatives includes cell cycle regulation and apoptosis induction.


Assuntos
Antineoplásicos/farmacologia , Xantonas/farmacologia , Antineoplásicos/síntese química , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Caspase 7/metabolismo , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Humanos , Relação Estrutura-Atividade , Xantonas/síntese química
9.
Am J Physiol Cell Physiol ; 306(7): C687-96, 2014 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-24477233

RESUMO

The sodium-coupled glucose transporter-1 (SGLT1)-based oral rehydration solution (ORS) used in the management of acute diarrhea does not substantially reduce stool output, despite the fact that glucose stimulates the absorption of sodium and water. To explain this phenomenon, we investigated the possibility that glucose might also stimulate anion secretion. Transepithelial electrical measurements and isotope flux measurements in Ussing chambers were used to study the effect of glucose on active chloride and fluid secretion in mouse small intestinal cells and human Caco-2 cells. Confocal fluorescence laser microscopy and immunohistochemistry measured intracellular changes in calcium, sodium-glucose linked transporter, and calcium-activated chloride channel (anoctamin 1) expression. In addition to enhancing active sodium absorption, glucose increased intracellular calcium and stimulated electrogenic chloride secretion. Calcium imaging studies showed increased intracellular calcium when intestinal cells were exposed to glucose. Niflumic acid, but not glibenclamide, inhibited glucose-stimulated chloride secretion in mouse small intestines and in Caco-2 cells. Glucose-stimulated chloride secretion was not seen in ileal tissues incubated with the intracellular calcium chelater BAPTA-AM and the sodium-potassium-2 chloride cotransporter 1 (NKCC1) blocker bumetanide. These observations establish that glucose not only stimulates active Na absorption, a well-established phenomenon, but also induces a Ca-activated chloride secretion. This may explain the failure of glucose-based ORS to markedly reduce stool output in acute diarrhea. These results have immediate potential to improve the treatment outcomes for acute and/or chronic diarrheal diseases by replacing glucose with compounds that do not stimulate chloride secretion.


Assuntos
Canais de Cloreto/metabolismo , Cloretos/metabolismo , Glucose/metabolismo , Íleo/metabolismo , Mucosa Intestinal/metabolismo , Animais , Anoctamina-1 , Transporte Biológico , Células CACO-2 , Cálcio/metabolismo , Quelantes/farmacologia , Canais de Cloreto/efeitos dos fármacos , Impedância Elétrica , Humanos , Íleo/efeitos dos fármacos , Imuno-Histoquímica , Mucosa Intestinal/efeitos dos fármacos , Cinética , Masculino , Moduladores de Transporte de Membrana/farmacologia , Camundongos , Microscopia Confocal , Proteínas de Neoplasias/metabolismo , Sódio/metabolismo , Transportador 1 de Glucose-Sódio/metabolismo
10.
Adv Exp Med Biol ; 812: 149-155, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24729227

RESUMO

The tumor vascular system, which is critical to the survival and growth of solid tumors, has been an attractive target for anticancer research. Building on studies that show that some flavonoids have anticancer vascular effects, we developed and analyzed the flavonoid derivative R24 [3, 6-bis (2-oxiranylmethoxy)-9H-xanthen-9-one]. A CAM assay revealed that R24 disrupted neovascular formation; fewer dendrites were detected and overall dendritic length was shorter in the R24-treated chicken embryos. The antiproliferative effect of R24 was measured by MTT assay in A549 (lung cancer), AsPC-1 (pancreatic cancer), HCT-116 (colorectal cancer), and PC-3 (prostate cancer) cell lines. R24 reduced proliferation with an IC50 of 3.44, 3.59, 1.22, and 11.83 µM, respectively. Cell-cycle analysis and Annexin-V/propidium iodide staining showed that R24 induced apoptosis. In addition, R24 regulated intracellular ROS production in a dose-dependent manner. CM-H2DCFDA staining indicated that intracellular ROS production increased with the R24 dose. In summary, we found that R24 exhibits potent antiangiogenic and antiproliferative effects, induces apoptosis, and promotes ROS production.


Assuntos
Flavonoides/farmacologia , Neoplasias/irrigação sanguínea , Neovascularização Patológica/prevenção & controle , Espécies Reativas de Oxigênio/metabolismo , Linhagem Celular Tumoral , Humanos
11.
Am J Vet Res ; 85(1)2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38113643

RESUMO

OBJECTIVE: Right dorsal colitis causes chronic colic associated with long-term treatment with nonsteroidal antiinflammatory drugs (NSAIDs). This study was designed to determine if NSAIDs could inhibit anion transporters that protect against intestinal mucosal injury in other species. ANIMALS: 20 healthy horses. METHODS: The effects of indomethacin (INDO) and firocoxib (FIR), on short-circuit current (Isc) in mucosa from the right dorsal colon (RDC) and right ventral colon (RVC) were measured in Ussing chambers by standard electrophysiological techniques. Immunohistochemical methods were used to detect apoptosis (caspase-3) with these NSAIDs and phenylbutazone (PBZ) and to locate the NKCC1 transporter. RESULTS: The Isc in RDC and RVC incubated with INDO or FIR was increased almost 3-fold (P < .0001) by prostaglandin E2 (PGE2) through a system inhibited by loop diuretics (P < .0001). Although these findings and anion replacement studies were consistent with anion secretion, the RDC also displayed an Isc response suggestive of a unique transporter apparently absent in RVC or NSAID-free solutions. In RDC, FIR, INDO, and PBZ induced apoptosis in the lower half of crypts. However, significant differences in apoptotic index were recorded in the RDC between NSAID-treated and control tissues (no NSAID). CLINICAL RELEVANCE: The effects of NSAIDs on Isc were consistent with reduced anion secretion, which could represent the pharmacological equivalent of the transport failure responsible for Cystic Fibrosis (CF) in other species. Failure of anion secretion could interfere with buffering acid from intraluminal fermentation, which could suggest a treatment target for right dorsal colitis.


Assuntos
Colite , Doenças dos Cavalos , Animais , Cavalos , Anti-Inflamatórios não Esteroides/farmacologia , Indometacina/farmacologia , Mucosa Intestinal , Colo , Ânions/farmacologia , Colite/veterinária , Apoptose , Doenças dos Cavalos/tratamento farmacológico
12.
EClinicalMedicine ; 72: 102630, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38800804

RESUMO

Background: Diarrhoeal disease poses a significant global health challenge, especially in children under three years old. Despite the effectiveness of oral rehydration therapy (ORT), its adoption remains low. Glucose-based ORS (GORS) is the standard, but novel formulations like glucose-free amino acid-based VS002A have emerged as potential alternatives. This study aimed to compare the safety and efficacy of VS002A against the standard WHO-ORS in treating non-cholera acute watery diarrhoea in children. Methods: A triple-blind, randomized trial enrolled 310 male infants and children aged 6-36 months, who were assigned to receive WHO-ORS or VS002A over a 16-month period, from June 2021 to September 2022. Both groups received standard of care, including zinc supplementation. The Primary study outcome measured was the duration of diarrhoea. Secondary outcomes included stool output, treatment failure and adverse events. Exploratory endpoints included urinary output, body weight changes, blood biochemistry, stool microbiology and gut health biomarkers. Findings: Both VS002A and WHO-ORS were well-tolerated with a low adverse event rate. While not different statistically (p = 0.10), duration of diarrhoea was shorter in children treated with VS002A vs. WHO-ORS (65.4 h vs. 72.6 h). Similarly, stool output was also lower vs. WHO-ORS in children treated with VS002A, though not statistically different (p = 0.40). Serum citrulline levels, an indicator of gut health, were higher in the VS002A group at 24 h suggesting a potential protective effect (p = 0.06). Interpretation: The findings of this study support the non-inferiority of VS002A, a glucose-free amino acid-based ORS compared to the WHO-ORS standard of care. VS002A was shown to be safe and effective in treating non-cholera acute watery diarrhoea in young children. VS002A may offer advantages in pathogen-driven diarrhoea, supported by trends toward a lower duration of diarrhoea and stool output within the per protocol group. Furthermore, individuals with prolonged diarrhoea, severe malnutrition, environmental enteric dysfunction or have issues with obesity or insulin resistance, could benefit from a glucose-free ORS. This research contributes to addressing the persistent challenge of childhood diarrhoea by presenting an alternative glucose-free ORS formulation with potential advantages in select scenarios, offering a promising avenue for improving paediatric diarrhoea management worldwide. Funding: The study was funded by Entrinsic Bioscience, LLC., Norwood, MA, USA.

13.
Adv Exp Med Biol ; 789: 195-201, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23852495

RESUMO

Amifostine is a first-line cytoprotective drug used to prevent radiotherapy-induced or chemotherapy-induced injuries. However, its mechanism of action is not well understood. In this study, freshly harvested bone marrow cells were treated with amifostine and analyzed with a series of mitochondrial indices. In vitro results showed that bone marrow cells treated with amifostine 0.5 h before irradiation (0.5 Gy) experienced several benefits, as compared to vehicle controls, including (1) reduced reactive oxygen species levels, which reduced the production of free radicals; (2) better preservation of mitochondria, as indicated by MitoTracker-positive staining and the increased intensity of staining; (3) reduced apoptosis, as demonstrated by Annexin V staining; and (4) a better proliferation rate, as illustrated by MTT assay. Our in vitro studies showed that amifostine-treated mice exhibited (1) higher ATP production; (2) reduced plasma IL-2 levels, suppressing the immune response triggered by radiotoxicity; and (3) enhanced radiation-induced production of granulocyte colony-stimulating factor. All of these processes benefit recovery from radiation-induced damage.


Assuntos
Amifostina/farmacologia , Células da Medula Óssea/efeitos dos fármacos , Medula Óssea/efeitos dos fármacos , Citocinas/metabolismo , Mitocôndrias/efeitos dos fármacos , Protetores contra Radiação/farmacologia , Adaptação Fisiológica/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Animais , Medula Óssea/crescimento & desenvolvimento , Medula Óssea/metabolismo , Células da Medula Óssea/metabolismo , Masculino , Camundongos , Mitocôndrias/metabolismo , Espécies Reativas de Oxigênio/metabolismo
14.
Adv Exp Med Biol ; 765: 371-377, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22879058

RESUMO

Mitochondrial DNA (mtDNA) is maternally inherited and controls the oxygen-related production of adenosine-5'-triphosphate, which is transported from the mitochondria to other cellular compartments and used as energy for cellular activities. The mtDNA is physically separated from nuclear DNA (nDNA). Ionizing radiation (IR) causes the release of both mtDNA and nDNA into circulation. Our previous study demonstrated that nDNA has potential to be a biodosimeter. In this study, branched DNA technology was used to explore the alteration pattern of mtDNA after IR. C57BL/6 mice were exposed to 0, 1.5, 3, 6, 8, or 10 Gy total body irradiation; thereafter, plasma mtDNA was assessed with samples collected at 3, 6, 9, 15, 24, 48, 72, or 168 h. We found that: (1) the designed probesets were specific for mtDNA extracted from the liver, and they recognized the small amount of mtDNA mixed in the nDNA; (2) plasma mtDNA exhibited a statistically significant increase only at 6 h after 8 Gy irradiation. The alteration of mtDNA was not dose-dependent or time-dependent; hence, it is unlikely to be an effective biodosimeter.


Assuntos
Núcleo Celular/genética , Núcleo Celular/efeitos da radiação , DNA Mitocondrial/sangue , DNA Mitocondrial/genética , Lesões por Radiação/diagnóstico , Irradiação Corporal Total , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Doses de Radiação , Lesões por Radiação/sangue , Lesões por Radiação/genética , Fatores de Tempo
15.
Adv Exp Med Biol ; 789: 257-264, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23852503

RESUMO

Interleukin 11 (IL-11) is a multifunctional cytokine isolated from bone marrow (BM)-derived stromal cells that promotes hematopoiesis and prolongs the life span of lethally irradiated animals. However, the underlying mechanism for the protective effect of IL-11 on BM is unclear. In this study, we explored the effect of IL-11 on irradiated BM cells. Freshly harvested BM cells were pretreated with 20 ng/ml of recombinant IL-11 for 30 min, irradiated with a dose of 0.5 Gy, cultured for 24 h, and then subjected to several assays. In vitro data showed that, as compared to the vehicle controls, IL-11: (1) reduced the production of reactive oxygen species; (2) reduced the alteration of mitochondrial membrane potential; (3) increased MitoTracker staining, suggesting that the number of mitochondria and their functions were better maintained; and (4) reduced apoptosis of BM cells and enhanced BM cell proliferation. In vivo studies of mice pretreated with saline or 100 µg/kg of IL-11 at 12 and 2 h before 10-Gy total body irradiation (TBI) demonstrated that G-CSF and IL-6 were significantly upregulated, whereas IL-2 and IL-4 were reduced. We found that IL-11 protects mitochondrial functions, acts with G-CSF and IL-6 to stimulate the growth of radiation-damaged BM, and reduces the immune response to radiation injury.


Assuntos
Medula Óssea/efeitos dos fármacos , Medula Óssea/efeitos da radiação , Interleucina-11/farmacologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/efeitos da radiação , Lesões Experimentais por Radiação/metabolismo , Lesões Experimentais por Radiação/prevenção & controle , Animais , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Medula Óssea/metabolismo , Células da Medula Óssea/metabolismo , Células da Medula Óssea/efeitos da radiação , Processos de Crescimento Celular/efeitos dos fármacos , Processos de Crescimento Celular/efeitos da radiação , Fator Estimulador de Colônias de Granulócitos/metabolismo , Interleucina-11/metabolismo , Interleucina-6/metabolismo , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos da radiação , Camundongos , Mitocôndrias/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Irradiação Corporal Total/métodos
16.
Adv Exp Med Biol ; 789: 273-280, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23852505

RESUMO

In this study, we investigated the response of irradiated bone marrow cells to granulocyte colony-stimulating factor (G-CSF). Freshly harvested bone marrow cells were treated with either saline (vehicle control) or 20 ng/ml of G-CSF. Thereafter, cells were separated into nonirradiated (no-IR) and irradiated (IR, 0.5 Gy) groups. IR cells exhibited a higher proliferation rate in response to G-CSF, as compared to the no-IR cells. Reduced levels of reactive oxygen species indicated that G-CSF-treated IR cells produced fewer free radicals, as compared to the no-IR cells. The G-CSF-treated IR cells also had a lower apoptotic rate than their no-IR counterparts. Furthermore, G-CSF-treated IR cells exhibited less alteration of mitochondrial membrane potential, as compared to the no-IR cells. Finally, the mitochondrial number increased in the G-CSF-treated IR cells. The radiation-induced increase in plasma IL-6 in vivo could be enhanced by the administration of G-CSF. The data suggest that radiation potentiates the response of bone marrow cells to G-CSF treatment.


Assuntos
Medula Óssea/efeitos dos fármacos , Medula Óssea/efeitos da radiação , Fator Estimulador de Colônias de Granulócitos/farmacologia , Animais , Medula Óssea/metabolismo , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Células da Medula Óssea/efeitos da radiação , Radicais Livres/metabolismo , Interleucina-6/sangue , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos da radiação , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo
17.
Commun Biol ; 6(1): 1237, 2023 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-38062160

RESUMO

Assessing gastrointestinal motility lacks simultaneous evaluation of intraluminal pressure (ILP), circular muscle (CM) and longitudinal muscle (LM) contraction, and lumen emptying. In this study, a sophisticated machine was developed that synchronized real-time recordings to quantify the intricate interplay between CM and LM contractions, and their timings for volume changes using high-resolution cameras with machine learning capability, the ILP using pressure transducers and droplet discharge (DD) using droplet counters. Results revealed four distinct phases, BPhase, NPhase, DPhase, and APhase, distinguished by pressure wave amplitudes. Fluid filling impacted LM strength and contraction frequency initially, followed by CM contraction affecting ILP, volume, and the extent of anterograde, retrograde, and segmental contractions during these phases that result in short or long duration DD. This comprehensive analysis sheds light on peristalsis mechanisms, understand their sequence and how one parameter influenced the other, offering insights for managing peristalsis by regulating smooth muscle contractions.


Assuntos
Motilidade Gastrointestinal , Peristaltismo , Animais , Camundongos , Peristaltismo/fisiologia , Motilidade Gastrointestinal/fisiologia , Contração Muscular/fisiologia , Intestino Delgado
18.
World J Gastrointest Pharmacol Ther ; 14(5): 39-49, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38174291

RESUMO

BACKGROUND: Amino-acid based medical foods have shown promise in alleviating symptoms of drug induced gastrointestinal side effects; particularly, diarrhea-predominant symptoms. Irritable bowel syndrome (IBS) is a gastrointestinal disorder that affects up to 9% of people globally, with diarrhea predominant IBS (IBS-D) being the most prevalent subtype. Further trials are needed to explore potential added benefits when integrated into standard care for IBS-D. AIM: To assess the effectiveness of an amino acid-based medical food as an adjunct to standard of care for adults with IBS-D. METHODS: This is a pragmatic, real world, open label, single arm study comparing a 2-week baseline assessment to a 2-week intervention period. One hundred adults, aged 18 to 65 years, with IBS-D, according to Rome IV criteria, were enrolled after completing a 2-week baseline assessment period and received a 2-week supply of an amino acid based medical food which was consumed at home twice daily on top of their standard of care. The primary outcome was an assessment of tolerability after 2-weeks of consumption, while secondary outcomes included changes in stool consistency (Bristol Stool Form Scale), severity of abdominal pain & discomfort, symptoms of urgency, Global Improvement Survey (GIS), and the IBS severity scoring system (IBS-SSS). RESULTS: The test product was well-tolerated as each participant successfully completed the full 14-day trial, and there were no instances of dropouts or discontinuation of the study product reported. Forty percent of participants achieved a 50% or more reduction in the number of days with type 6-7 bowel movements (IBS-D stool consistency responders). Fifty-three percent of participants achieved a clinically meaningful reduction of 30% in mean weekly pain scores, and 55% experienced the same for mean weekly discomfort scores (IBS-D pain and discomfort responders). Participants experienced a mean -109.4 (95% confidence interval: -130.1, -88.8) point reduction on the IBS-SSS and 52% experienced a minimally clinically important difference of > 95 points. An IBS-SSS category shift from severe to moderate or mild occurred in 69% of participants. For functional symptoms, 76% of participants reported symptom relief on the GIS. CONCLUSION: The amino acid-based medical food was well-tolerated, when added to the standard of care, and demonstrated improvements in both overall IBS symptom severity and IBS-D symptoms within just 2 wk.

19.
Physiol Rep ; 11(10): e15681, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37217446

RESUMO

Increased gut permeability is implicated in the initiation and extent of the cytokine inflammatory response associated with exertional heat stroke (EHS). The primary objective of this study was to determine if a five amino acid oral rehydration solution (5AAS), specifically designed for the protection of the gastrointestinal lining, would prolong time to EHS, maintain gut function and dampen the systemic inflammatory response (SIR) measured during EHS recovery. Male C57/BL6J mice instrumented with radiotelemetry were gavaged with 150 µL of 5AAS or H2 O, and ≈12 h later were either exposed to an EHS protocol where mice exercised in a 37.5°C environmental chamber to a self-limiting maximum core temperature (Tc,max) or performed the exercise control (EXC) protocol (25°C). 5AAS pretreatment attenuated hypothermia depth and length (p < 0.005), which are indicators of EHS severity during recovery, without any effect on physical performance or thermoregulatory responses in the heat as determined by percent body weight lost (≈9%), max speed (≈6 m/min), distance (≈700 m), time to Tc,max (≈160 min), thermal area (≈550°C∙min), and Tc,max (42.2°C). EHS groups treated with 5AAS showed a significant decrease in gut transepithelial conductance, decreased paracellular permeability, increased villus height, increased electrolyte absorption and changes in tight junction protein expression pattern suggestive of improved barrier integrity (p < 0.05). No differences were witnessed between EHS groups in acute phase response markers of liver, circulating SIR markers, or indicators of organ damage during recovery. These results suggest that a 5AAS improves Tc regulation during EHS recovery through maintaining mucosal function and integrity.


Assuntos
Golpe de Calor , Hipotermia , Camundongos , Masculino , Animais , Hipotermia/metabolismo , Golpe de Calor/prevenção & controle , Citocinas/metabolismo , Mucosa Intestinal/metabolismo , Aminoácidos/metabolismo
20.
Cytokine ; 58(2): 169-77, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22277799

RESUMO

PURPOSE: To determine the plasma concentrations of acute responding cytokines/chemokines following 9-Gy ionizing radiation in C57BL/6 (radiation tolerant) and C3H/HeN (radiation sensitive) murine strains. METHODS AND MATERIALS: Mice (5/group) received 9-Gy total body irradiation (TBI), and the plasma from each mouse was collected at 6h or 1, 2, 4, or 10 days after TBI. A multiplex bead array was used to assess the levels of 32 cytokines/chemokines in plasma to determine their common and strain-specific temporal responses. RESULTS: The plasma levels of five cytokines/chemokines (Axl, FasL, ICAM-1, TARC, and TSLP) were beyond the detectable level. Five (VEGF, IL-2, IL-5, IL-17, and CD30) were unaffected by irradiation in either strain. Temporal patterns were similar in both murine strains for 10 of the cytokines tested, including G-CSF, IL-6, TCA-3, MCP-1, MIP-1γ, KC, CXCL 13, CXCL 16, MDC, and TIMP-1; the other 12 molecules (GM-CSF, IL-3, SCF, IL-1ß, IL-4, IL-10, IL-12p70, MIP-1α, Eotaxin, TNF-α, sTNF-R1, and CD40) showed strain-specific response patterns. While a number of cytokines had temporal response patterns following TBI, the strains exhibited quantitatively different results. CONCLUSIONS: The levels of 27 of the 32 plasma cytokines measured indicate the following: (1) different cytokine concentrations and temporal patterns in the two strains may partly explain different radiation sensitivities and sequelae following irradiation; (2) many of the cytokines/chemokines exhibit similar temporal responses in the two strains. These responses suggest the potential value of using a panel of cytokine/chemokine temporal patterns for radiation dosimetry. Although radiation doses will be difficult to quantitate due to the large variation in levels and temporal responses exhibited in the two murine strains, serial measurements of cytokines might help identify subjects exposed to radiation.


Assuntos
Quimiocinas/metabolismo , Citocinas/metabolismo , Irradiação Corporal Total , Animais , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA