RESUMEN
The present study delved into the chemical composition, antioxidant, and anti-inflammatory properties of three dry edible beans: Black (BL), Great Northern (GN), and Pinto (PN). The beans were soaked, cooked, and subjected to in vitro gastrointestinal (GI) digestion. BL bean exhibited significantly higher gastric (42%) and intestinal (8%) digestion rates. Comparative assessment of soluble GI-digested fractions (<3 kDa) revealed that the GN bean exhibited the highest abundance of dipeptides (P < 0.05). The BL bean fraction displayed a 4-fold increase in tripeptides (P < 0.05). Both BL and PN bean fractions are high in essential free amino acids, flavonols, and derivatives of hydroxybenzoic acid when compared to the GN bean. All the beans exhibited the ability to mitigate TNF-α-induced pro-inflammatory signaling; however, the BL bean fraction was the most effective at lowering AAPH-induced oxidative stress in HT-29 cells, followed by the GN bean (P < 0.05). In contrast, a low antioxidant effect was observed with PN beans.
Asunto(s)
Antiinflamatorios , Antioxidantes , Culinaria , Digestión , Tracto Gastrointestinal , Phaseolus , Antioxidantes/química , Antioxidantes/farmacología , Humanos , Digestión/efectos de los fármacos , Antiinflamatorios/química , Antiinflamatorios/farmacología , Phaseolus/química , Tracto Gastrointestinal/metabolismo , Tracto Gastrointestinal/efectos de los fármacos , Células HT29 , Estrés Oxidativo/efectos de los fármacos , Extractos Vegetales/química , Extractos Vegetales/farmacología , Modelos Biológicos , Semillas/químicaRESUMEN
BACKGROUND: Macrophages are highly plastic innate immune cells that play key roles in host defense, tissue repair, and homeostasis maintenance. In response to divergent stimuli, macrophages rapidly alter their functions and manifest a wide polarization spectrum with two extremes: M1 or classical activation and M2 or alternative activation. Extracellular vesicles (EVs) secreted from differentially activated macrophages have been shown to have diverse functions, which are primarily attributed to their microRNA cargos. The role of protein cargos in these EVs remains largely unexplored. Therefore, in this study, we focused on the protein cargos in macrophage-derived EVs. RESULTS: Naïve murine bone marrow-derived macrophages were treated with lipopolysaccharide or interlukin-4 to induce M1 or M2 macrophages, respectively. The proteins of EVs and their parental macrophages were subjected to quantitative proteomics analyses, followed by bioinformatic analyses. The enriched proteins of M1-EVs were involved in proinflammatory pathways and those of M2-EVs were associated with immunomodulation and tissue remodeling. The signature proteins of EVs shared a limited subset of the proteins of their respective progenitor macrophages, but they covered many of the typical pathways and functions of their parental cells, suggesting their respective M1-like and M2-like phenotypes and functions. Experimental examination validated that protein cargos in M1- or M2-EVs induced M1 or M2 polarization, respectively. More importantly, proteins in M1-EVs promoted viability, proliferation, and activation of T lymphocytes, whereas proteins in M2-EVs potently protected the tight junction structure and barrier integrity of epithelial cells from disruption. Intravenous administration of M2-EVs in colitis mice led to their accumulation in the colon, alleviation of colonic inflammation, promotion of M2 macrophage polarization, and improvement of gut barrier functions. Protein cargos in M2-EVs played a key role in their protective function in colitis. CONCLUSION: This study has yielded a comprehensive unbiased dataset of protein cargos in macrophage-derived EVs, provided a systemic view of their potential functions, and highlighted the important engagement of protein cargos in the pathophysiological functions of these EVs.
Asunto(s)
Colitis , Vesículas Extracelulares , Animales , Ratones , Macrófagos/metabolismo , Fagocitosis , Vesículas Extracelulares/metabolismo , Colitis/metabolismo , Inflamación/metabolismoRESUMEN
AIMS: As a critical regulatory point of nutrient sensing, growth and metabolism, the mechanistic target of rapamycin complex 1 (mTORC1) is poised to influence intestinal homeostasis under basal conditions and in disease state. Intestinal barrier integrity ensures tissue homeostasis by closely regulating the permeability of the epithelium to lumenal contents. The role of mTORC1 in the regulation of intestinal barrier function and permeability remains to be fully elucidated. MATERIALS AND METHODS: In this study, we employed lentivirus-mediated knockdown of mTORC1 signaling-associated proteins Raptor (regulatory-associated protein of mTOR) and TSC2 (tuberin) to ascertain the effects of constitutive activation or repression of mTORC1 activity on barrier function in Caco-2 cell monolayers. KEY FINDINGS: Results showed that the loss of Raptor concomitantly raised the transepithelial electrical resistance (TEER) and para/transcellular permeability leading to a cell monolayer that is leaky for dextran yet electrically resistant to the movement of ions. Paracellular permeability was linked to the downregulation of tight junction protein expression and enhanced autophagy. Raptor-depleted cells had the highest abundance of myosin binding subunit MYPT1 concomitantly with the lowest abundance of p-MYPT1 (Thr696) and phosphorylated myosin light chain (p-MLC, Ser19) implying that MLC phosphatase activity was increased resulting in MLC relaxation. Although rapamycin suppressed mTORC1 activity and decreased the abundance of tight junction proteins in control cells, rapamycin caused a modest increase of TEER compared to Raptor knockdown. SIGNIFICANCE: The study showed that epithelium paracellular permeability of small molecular weight dextran is dissociated from TEER.
Asunto(s)
Cadenas Ligeras de Miosina , Rapaces , Animales , Células CACO-2 , Dextranos/metabolismo , Impedancia Eléctrica , Humanos , Mucosa Intestinal/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Cadenas Ligeras de Miosina/metabolismo , Permeabilidad , Monoéster Fosfórico Hidrolasas/metabolismo , Fosforilación , Rapaces/metabolismo , Proteína Reguladora Asociada a mTOR/metabolismo , Proteína Reguladora Asociada a mTOR/farmacología , Sirolimus/farmacología , Proteínas de Uniones Estrechas/metabolismo , Uniones Estrechas/metabolismo , Proteína 2 del Complejo de la Esclerosis Tuberosa/metabolismoRESUMEN
Although the role of mechanistic target of rapamycin complex 1 (mTORC1) in lipid metabolism has been the subject of previous research, its function in chylomicron production is not known. In this study, we created three stable human colorectal adenocarcinoma Caco-2 cell lines exhibiting normal, low, or high mTORC1 kinase activity, and used these cells to investigate the consequences of manipulating mTORC1 activity on enterocyte differentiation and chylomicron-like particle production. Constitutively active mTORC1 induced Caco-2 cell proliferation and differentiation (as judged by alkaline phosphatase activity) but weakened transepithelial electrical resistance (TEER). Repressed mTORC1 activity due to the knockdown of RPTOR significantly decreased the expression of lipogenic genes FASN, DGAT1, and DGAT2, lipoprotein assembly genes APOB and MTTP, reduced protein expression of APOB, MTTP, and FASN, downregulated the gene expression of very long-chain fatty acyl-CoA ligase (FATP2), acyl-CoA binding protein (DBI), and prechylomicron transport vesicle-associated proteins VAMP7 (vesicle-associated membrane protein 7) and SAR1B (secretion associated Ras related GTPase 1B) resulting in the repression of apoB-containing triacylglycerol-rich lipoprotein secretion. Exposure of Caco-2 cells harboring a constitutively active mTORC1 to short-chain fatty acid derivatives, R-α-lipoic acid and 4-phenylbutyric acid, downregulated chylomicron-like particle secretion by interfering with the lipidation and assembly of the particles, and concomitantly repressed mTORC1 activity with no change to Raptor abundance or PRAS40 (Thr246) phosphorylation. R-α-lipoic acid and 4-phenylbutyric acid may be useful to mitigate intestinal lipoprotein overproduction and associated postprandial inflammation.
Asunto(s)
Quilomicrones , Enterocitos , Proteínas de Unión al GTP Monoméricas , Fenilbutiratos , Proteína Reguladora Asociada a mTOR , Ácido Tióctico , Apolipoproteínas B/metabolismo , Células CACO-2 , Quilomicrones/metabolismo , Coenzima A Ligasas/metabolismo , Enterocitos/efectos de los fármacos , Enterocitos/metabolismo , Humanos , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Proteínas de Unión al GTP Monoméricas/genética , Proteínas de Unión al GTP Monoméricas/metabolismo , Fenilbutiratos/metabolismo , Fenilbutiratos/farmacología , Proteína Reguladora Asociada a mTOR/genética , Proteína Reguladora Asociada a mTOR/metabolismo , Ácido Tióctico/metabolismo , Ácido Tióctico/farmacologíaRESUMEN
AIMS: The sustained activation of intestinal mechanistic target of rapamycin complex 1 (mTORC1) brought about by repeated mucosal insult or injury has been linked to escalation of gut inflammatory response, which may progress to damage the epithelium if not controlled. This study investigated the role of mTORC1 in the response of macrophage and enterocyte to inflammatory stimuli. MATERIALS AND METHODS: We genetically manipulated human THP-1 monocytes and epithelial intestinal Caco-2 cells to generate stable cell lines with baseline, low or high mTORC1 kinase activity. The effects of THP-1 macrophage secretions onto Caco-2 cells were investigated by means of conditioned media transfer experiments. KEY FINDINGS: The priming of mTORC1 for activation promoted lipopolysaccharide (LPS)-mediated THP-1 macrophage immune response as evidenced by the stimulation of inflammatory mediators (TNFα, IL-6, IL-8, IL-1ß and IL-10). The treatment of THP-1 macrophages with LPS more than the manipulated level of mTORC1 activity of macrophages determined whether cytokine gene expression was induced in Caco-2 cells. LPS carry over was not responsible for the stimulation of Caco-2 cells' cytokine response. Knocking down Raptor in Caco-2 cells or treating Caco-2 cells with rapamycin enhanced Caco-2 TNFα gene expression revealing the anti-inflammatory role of a functional mTORC1 in intestinal epithelial cells exposed to macrophage-derived pro-inflammatory stimuli. SIGNIFICANCE: Taken together, mTORC1 differentially impacts the immune responses of THP-1-derived macrophages and Caco-2 epithelial cells when placed in a pro-inflammatory microenvironment.
Asunto(s)
Citocinas/metabolismo , Células Epiteliales/metabolismo , Mediadores de Inflamación/metabolismo , Intestinos/citología , Macrófagos/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Células CACO-2 , Medios de Cultivo Condicionados/farmacología , Citocinas/genética , Citoprotección/efectos de los fármacos , Células Epiteliales/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Lipopolisacáridos/farmacología , Activación de Macrófagos/efectos de los fármacos , Macrófagos/efectos de los fármacos , Modelos Biológicos , Transducción de Señal/efectos de los fármacos , Células THP-1 , Proteína 2 del Complejo de la Esclerosis Tuberosa/metabolismoRESUMEN
The mechanistic target of rapamycin complex 1 (mTORC1) signaling is the prototypical pathway regulating protein synthesis and cell proliferation. The level of mTORC1 activity is high in intestinal stem cells located at the base of the crypts and thought to gradually decrease as transit-amplifying cells migrate out of the crypts and differentiate into enterocytes, goblet cells or enteroendocrine cells along the epithelium. The unknown mechanism responsible for the silencing of intestinal epithelium mTORC1 during cell differentiation was investigated in Caco-2 cells, which spontaneously differentiate into enterocytes in standard growth medium. The results show that TSC2, an upstream negative regulator of mTORC1 was central to mTORC1 silencing in differentiated Caco-2 cells. AMPK-mediated activation of TSC2 (Ser1387) and repression of Raptor (Ser792), an essential component of mTORC1, were stimulated in differentiated Caco-2 cells. ERK1/2-mediated repression of TSC2 (Ser664) seen in undifferentiated Caco-2 cells was lifted in differentiated cells. IRS-1-mediated activation of AKT (Thr308) phosphorylation was stimulated in differentiated Caco-2 cells and may be involved in cross-pathway repression of ERK1/2. Additionally, PRAS40 (Thr246) phosphorylation was decreased in differentiated Caco-2 cells compared to undifferentiated cells allowing dephosphorylated PRAS40 to displace Raptor thereby repressing mTORC1 kinase activity.
Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Mucosa Intestinal/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/antagonistas & inhibidores , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Proteína 2 del Complejo de la Esclerosis Tuberosa/metabolismo , Proteínas Adaptadoras Transductoras de Señales/química , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Células CACO-2 , Diferenciación Celular , Regulación hacia Abajo , Humanos , Mucosa Intestinal/citología , Sistema de Señalización de MAP Quinasas , Modelos Biológicos , Fosforilación , Proteína Reguladora Asociada a mTOR/química , Proteína Reguladora Asociada a mTOR/metabolismo , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismoRESUMEN
The mechanistic target of rapamycin complex 1 (mTORC1) is a central modulator of inflammation and tumorigenesis in the gastrointestinal tract. Growth factors upregulate mTORC1 via the PI3K/AKT and/or Ras/MAPK signal pathways. Curcumin (CUR), a polyphenol found in turmeric roots (Curcuma longa) can repress mTORC1 kinase activity in colon cancer cell lines; however, key aspects of CUR mechanism of action remain to be elucidated including its primary cellular target. We investigated the molecular effects of physiologically attainable concentration of CUR (20 µM) in the intestinal lumen on mTORC1 signaling in Caco-2 cells. CUR markedly inhibited mTORC1 kinase activity as determined by the decreased phosphorylation of p70S6K (Thr389, -99%, P < 0.0001) and S6 (Ser235/236, -92%, P < 0.0001). Mechanistically, CUR decreased IRS-1 protein abundance (-80%, P < 0.0001) thereby downregulating AKT phosphorylation (Ser473, -94%, P < 0.0001) and in turn PRAS40 phosphorylation (Thr246, -99%, P < 0.0001) while total PRAS40 abundance was unchanged. The use of proteasome inhibitor MG132 showed that CUR-mediated loss of IRS-1 involved proteasomal degradation. CUR lowered Raptor protein abundance, which combined with PRAS40 hypophosphorylation, suggests CUR repressed mTORC1 activity by inducing compositional changes that hinder the complex assembly. In addition, CUR activated AMPK (Thr172 phosphorylation, P < 0.0001), a recognized repressor of mTORC1, and AMPK upstream regulator LKB1. Although cargo adapter protein p62 was decreased by CUR (-49%, P < 0.004), CUR did not significantly induce autophagy. Inhibition of AKT/mTORC1 signaling by CUR may have lifted the cross-inhibition onto MAPK signaling, which became induced; p-ERK1/2 (+670%, P < 0.0001), p-p38 (+1433%, P < 0.0001). By concomitantly targeting IRS-1 and AMPK, CUR's mechanism of mTORC1 inhibition is distinct from that of rapamycin.
Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Proteínas Sustrato del Receptor de Insulina/deficiencia , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Proteínas Quinasas Activadas por AMP/genética , Células CACO-2 , Curcumina , Activación Enzimática/efectos de los fármacos , Activación Enzimática/genética , Humanos , Proteínas Sustrato del Receptor de Insulina/metabolismo , Sistema de Señalización de MAP Quinasas/genética , Diana Mecanicista del Complejo 1 de la Rapamicina/genéticaRESUMEN
Widely accessible food phytochemicals such as curcumin have been reported to have anti-inflammatory and anticarcinogenic properties. However, curcumin has poor absorption in the gut, and piperine has been of interest as a dietary compound that can enhance curcumin bioavailability. The aim of this study was to develop and optimize a technique using reversed-phase chromatography with multi-wavelength detection for the simultaneous measurement of curcumin and piperine in various biological matrices. Emodin was used as an internal standard. Protein precipitation and liquid-liquid extraction based on acetonitrile provided good recovery of these analytes. A 150 mm × 4.6 mm I.D. Luna C18 column was used under isocratic conditions to separate curcumin, piperine, and emodin with baseline resolution, and with good separation from other sample components, in as little as 4 min. The detection limits for curcumin and piperine were 3 and 7 ng/mL, respectively. This method has been used to quantitate these compounds in samples such as human intestinal epithelial cell lysates and mouse plasma or GI tissues in research aimed at examining the bioavailability of curcumin in the presence of piperine.
Asunto(s)
Alcaloides/sangre , Benzodioxoles/sangre , Cromatografía de Fase Inversa/métodos , Curcumina/análisis , Piperidinas/sangre , Alcamidas Poliinsaturadas/sangre , Alcaloides/química , Alcaloides/farmacocinética , Animales , Benzodioxoles/química , Benzodioxoles/farmacocinética , Disponibilidad Biológica , Cromatografía Líquida de Alta Presión , Curcumina/química , Curcumina/farmacocinética , Emodina , Humanos , Límite de Detección , Modelos Lineales , Masculino , Ratones , Piperidinas/química , Piperidinas/farmacocinética , Alcamidas Poliinsaturadas/química , Alcamidas Poliinsaturadas/farmacocinética , Reproducibilidad de los ResultadosRESUMEN
The persistent activation of intestinal mechanistic target of rapamycin complex 1 (mTORC1) triggered by mucosal stress has been linked to deregulation of the gut immune response resulting in intestinal inflammation and cell death. The present study investigated the regulatory properties of food-derived mTORC1 modulators, curcumin, and piperine, toward the polarization of stimulated macrophages and the differentiation of monocytes at two mTORC1 activity levels (baseline and elevated). To that end, we created stable human THP-1 monocytes exhibiting normal or constitutively active mTORC1. Curcumin or its combination with piperine, but not piperine alone, suppressed mTORC1 kinase activity, curtailed lipopolysaccharide-mediated inflammatory response of THP-1 macrophages, and repressed macrophage activation by inhibiting signaling pathways involved in M1 (mTORC1) and M2 (mTORC2 and cAMP response element binding protein) polarization. The effects of piperine in the curcumin/piperine combination were modest overall, indicating it was curcumin that modulated differentiating monocytes into acquiring a M0 macrophage phenotype characterized by low inflammatory cytokine output.
Asunto(s)
Curcumina/farmacología , Citocinas/metabolismo , Macrófagos/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Alcaloides/farmacología , Animales , Antiinflamatorios no Esteroideos/farmacología , Benzodioxoles/farmacología , Diferenciación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Curcuma/química , Humanos , Inmunidad/efectos de los fármacos , Lipopolisacáridos/efectos adversos , Activación de Macrófagos/efectos de los fármacos , Monocitos/metabolismo , Fenotipo , Piper nigrum/química , Piperidinas/farmacología , Alcamidas Poliinsaturadas/farmacología , Transducción de Señal/efectos de los fármacos , Células THP-1RESUMEN
The constitutive activation of the mechanistic target of rapamycin complex 1 (mTORC1) leads to the overproduction of apoB-containing triacylglycerol-rich lipoproteins in HepG2 cells. R-α-lipoic acid (LA) and 4-phenylbutyric acid (PBA) have hypolipidemic function but their mechanisms of action are not well understood. Here, we reported that LA and PBA regulate hepatocellular lipid metabolism via distinct mechanisms. The use of SQ22536, an inhibitor of adenylyl cyclase, revealed cAMP's involvement in the upregulation of CPT1A expression by LA but not by PBA. LA decreased the secretion of proprotein convertase subtilisin/kexin type 9 (PCSK9) in the culture media of hepatic cells and increased the abundance of LDL receptor (LDLR) in cellular extracts in part through transcriptional upregulation. Although PBA induced LDLR gene expression, it did not translate into more LDLR proteins. PBA regulated cellular lipid homeostasis through the induction of CPT1A and INSIG2 expression via an epigenetic mechanism involving the acetylation of histone H3, histone H4, and CBP-p300 at the CPT1A and INSIG2 promoters.
RESUMEN
Phytosterols are natural health-promoting bioactive compounds; however, phytosterols have very limited bioavailability due to their crystalline lipophilic structure. With the aim of improving bioaccessibility, low-crystallinity phytosterol nanoparticles were generated by supercritical carbon dioxide (SC-CO2 ) impregnation of phytosterols into nanoporous starch aerogels (NSAs). The in vitro bioaccessibility of the phytosterol nanoparticles (35%) was significantly higher than that of the crude phytosterols (3%) after sequential oral, gastric, and intestinal digestion. The percentages of starch hydrolysis were not different among the various NSA preparations and reached to 64% after sequential digestion. The zeta potential of the phytosterol nanoparticles was higher compared to that of crude phytosterols in the micellar phase; indicating higher stability. The findings of this study support the use of NSA to produce nanoparticles of reduced crystallinity to improve the bioaccessibility of the lipophilic bioactive compounds. PRACTICAL APPLICATIONS: This novel process can decrease the size and crystallinity of phytosterols and thus improve phytosterols' bioavailability. It is a blueprint to apply to other water insoluble food bioactives. This novel approach may (i) improve the health benefits of water-insoluble bioactives; (ii) enable food manufacturers to add water-insoluble bioactives into low- and high-fat foods to produce health-promoting foods; and (iii) enhance the cost-benefit ratio of water insoluble bioactives.
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Nanopartículas/química , Fitosteroles/química , Fitosteroles/metabolismo , Almidón/química , Humanos , Micelas , Modelos Biológicos , Nanoporos , Tamaño de la PartículaRESUMEN
Dextran sulfate sodium (DSS) present in the tissues of DSS-treated laboratory animals inhibits quantitative real-time qPCR (RT-qPCR) and thus may be source of experimental errors. A recent systematic review concluded that the reporting of experimental method was insufficient in a majority of DSS studies and contributed to the poor reproducibility of experiments. Here we compared two DSS cleanup protocols applied to mouse tissue RNA preparations based on silica membrane spin column and lithium chloride precipitation. In absence of cleanup, exogenous DSS significantly inhibited reverse transcription and cDNA amplification at concentrations of 5â¯×â¯10-3â¯g/L and above during the quantification of IL8 mRNA levels in THP-1 macrophages. Silica membrane spin columns removed DSS from mouse RNA preparations and eliminated DSS-induced inhibition of qPCR. Mouse RNA isolated from DSS-treated tissues and purified with silica membrane spin columns was suitable for RT-qPCR and assessment of inflammatory biomarkers.
Asunto(s)
Biomarcadores/análisis , Colitis/metabolismo , Inflamación/metabolismo , ARN Mensajero/aislamiento & purificación , Error Científico Experimental , Manejo de Especímenes/métodos , Animales , Colitis/inducido químicamente , Citocinas/genética , Sulfato de Dextran , Humanos , Inflamación/inducido químicamente , Masculino , Ratones , Ratones Endogámicos C57BL , ARN Mensajero/análisis , Células THP-1RESUMEN
In the past two decades, significant advances have been made in the etiology of lipid disorders. Concomitantly, the discovery of liporegulatory functions of certain short-chain fatty acids has generated interest in their clinical applications. In particular, butyric acid (BA) and its derivative, 4-phenylbutyric acid (PBA), which afford health benefits against lipid disorders while being generally well tolerated by animals and humans have been assessed clinically. This review examines the evidence from cell, animal and human studies pertaining to the lipid-regulating effects of BA and PBA, their molecular mechanisms and therapeutic potential. Collectively, the evidence supports the view that intakes of BA and PBA benefit lipid homeostasis across biological systems. We reviewed the evidence that BA and PBA downregulate de novo lipogenesis, ameliorate lipotoxicity, slow down atherosclerosis progression, and stimulate fatty acid ß-oxidation. Central to their mode of action, BA appears to function as a histone deacetylase (HDAC) inhibitor while PBA acts as a chemical chaperone and/or a HDAC inhibitor. Areas of further inquiry include the effects of BA and PBA on adipogenesis, lipolysis and apolipoprotein metabolism.
Asunto(s)
Ácido Butírico/farmacología , Metabolismo de los Lípidos/efectos de los fármacos , Fenilbutiratos/farmacología , Adipogénesis/efectos de los fármacos , Animales , Aterosclerosis/tratamiento farmacológico , Aterosclerosis/metabolismo , Ácido Butírico/metabolismo , Ácido Butírico/uso terapéutico , Inhibidores de Histona Desacetilasas/metabolismo , Inhibidores de Histona Desacetilasas/uso terapéutico , Humanos , Fenilbutiratos/metabolismo , Fenilbutiratos/uso terapéuticoRESUMEN
mTORC1 signaling is the prototypical pathway regulating protein synthesis and cell proliferation. mTORC1 is active in stem cells located at the base of intestinal crypts but silenced as transit-amplifying cells differentiate into enterocytes or secretory cells along the epithelium. After an insult or injury, self-limiting and controlled activation of mTORC1 is critical for the renewal and repair of intestinal epithelium. mTORC1 promotes epithelial cell renewal by driving cryptic stem cell division, and epithelial cell repair by supporting the dedifferentiation and proliferation of enterocytes or secretory cells. Under repeated insult or injury, mTORC1 becomes constitutively active, triggering an irreversible return to stemness, cell division, proliferation, and inflammation among dedifferentiated epithelial cells. Epithelium-derived cytokines promulgate inflammation within the lamina propria, which in turn releases inflammatory factors that act back on the epithelium where undamaged intestinal epithelial cells participate in the pervading state of inflammation and become susceptible to tumorigenesis.
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Carcinogénesis/metabolismo , Carcinogénesis/patología , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patología , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Cicatrización de Heridas , Animales , HumanosRESUMEN
Inflammatory bowel disease (IBD) is a chronic, inflammatory condition of the gastrointestinal tract. Patients with IBD present with debilitating symptoms that alter the quality of life and can develop into severe complications requiring surgery. Epidemiological evidence indicates Westernized societies have an elevated IBD burden when compared with Asian societies. Considering the stark contrast between the typical Western and Eastern dietary patterns, it is postulated that differences in food and lifestyle contribute to lower IBD incidence in Asian countries. Soybeans (Glycine max), which are consumed in high quantities and as various preparations in Eastern societies, contain a wealth of natural, biologically active compounds that include isoflavones, bioactive peptides, protease inhibitors, and phytosterols, among many others. These compounds have been shown to improve human health, and preclinical evidence suggests they have potential to improve the prognosis of IBD. This review summarizes the current state of evidence regarding the effects and the mechanisms of action of these soybean-derived bioactive compounds in experimental models of IBD.
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Dieta/métodos , Glycine max/química , Enfermedades Inflamatorias del Intestino/dietoterapia , Fitoquímicos/uso terapéutico , Dieta Occidental/efectos adversos , Humanos , Incidencia , Enfermedades Inflamatorias del Intestino/epidemiología , Enfermedades Inflamatorias del Intestino/etiología , Isoflavonas/uso terapéutico , Estilo de Vida , Calidad de VidaRESUMEN
Persistent activation of the mechanistic target of rapamycin complex 1 (mTORC1) is linked to sustained inflammation and progression of colorectal cancer. Widely available dietary phenolics, curcumin and piperine are purported to have antiinflammatory and anticarcinogenic activities through yet-to-be-delineated multitarget mechanisms. Piperine is also known to increase the bioavailability of dietary components, including curcumin. The objective of the study was to determine whether curcumin and piperine have individual and combined effects in the setting of gut inflammation by regulating mTORC1 in human intestinal epithelial cells. Results show that curcumin repressed (a) mTORC1 activity (measured as changes in the phosphorylation state of p70 ribosomal protein S6 kinase B1 and 40S ribosomal protein S6) in a dose-dependent manner (2.5-20 µM, P<.007) and (b) synthesis of nascent proteins. Piperine inhibited mTORC1 activity albeit at comparatively higher concentrations than curcumin. The combination of curcumin + piperine further repressed mTORC1 signaling (P<.02). Mechanistically, curcumin may repress mTORC1 by preventing TSC2 degradation, the conserved inhibitor of mTORC1. Results also show that a functional mTORC1 was required for the transcription of TNFα as Raptor knockdown abrogated TNFα gene expression. Curcumin, piperine and their combination inhibited TNFα gene expression at baseline but failed to do so under conditions of mTORC1 hyperactivation. TNFâ-induced cyclooxygenase-2 expression was repressed by curcumin or curcumin + piperine at baseline and high mTORC1 levels. We conclude that curcumin and piperine, either alone or in combination, have the potential to down-regulate mTORC1 signaling in the intestinal epithelium with implications for tumorigenesis and inflammation.
Asunto(s)
Alcaloides/farmacología , Benzodioxoles/farmacología , Curcumina/farmacología , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Piperidinas/farmacología , Alcamidas Poliinsaturadas/farmacología , Factor de Necrosis Tumoral alfa/metabolismo , Células CACO-2 , Diferenciación Celular/efectos de los fármacos , Ciclooxigenasa 2/metabolismo , Sinergismo Farmacológico , Células HT29 , Humanos , Diana Mecanicista del Complejo 1 de la Rapamicina/antagonistas & inhibidores , Inhibidores de la Síntesis de la Proteína/farmacología , Transducción de Señal/efectos de los fármacos , Proteína 2 del Complejo de la Esclerosis Tuberosa/metabolismoRESUMEN
Overwhelming evidence indicates that diets rich in fruits and vegetables are protective against common chronic diseases, such as cancer, obesity and cardiovascular disease. Leafy green vegetables, in particular, are recognized as having substantial health-promoting activities that are attributed to the functional properties of their nutrients and non-essential chemical compounds. Spinach (Spinacia oleracea L.) is widely regarded as a functional food due to its diverse nutritional composition, which includes vitamins and minerals, and to its phytochemicals and bioactives that promote health beyond basic nutrition. Spinach-derived phytochemicals and bioactives are able to (i) scavenge reactive oxygen species and prevent macromolecular oxidative damage, (ii) modulate expression and activity of genes involved in metabolism, proliferation, inflammation, and antioxidant defence, and (iii) curb food intake by inducing secretion of satiety hormones. These biological activities contribute to the anti-cancer, anti-obesity, hypoglycemic, and hypolipidemic properties of spinach. Despite these valuable attributes, spinach consumption remains low in comparison to other leafy green vegetables. This review examines the functional properties of spinach in cell culture, animals and humans with a focus on the molecular mechanisms by which spinach-derived non-essential phytochemicals and bioactives, such as glycolipids and thylakoids, impart their health benefits.
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Alimentos Funcionales , Fitoquímicos/farmacología , Spinacia oleracea/química , Animales , Antiinflamatorios/farmacología , Fármacos Antiobesidad/farmacología , Anticolesterolemiantes/farmacología , Antineoplásicos/farmacología , Antioxidantes/farmacología , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Glucolípidos/farmacología , Humanos , Hipoglucemiantes/farmacología , Estrés Oxidativo/efectos de los fármacos , Ensayos Clínicos Controlados Aleatorios como Asunto , Especies Reactivas de Oxígeno/metabolismo , Tilacoides/químicaRESUMEN
Fibroblast growth factor 21 (FGF21) gene expression is altered by a wide array of physiological, metabolic, and environmental factors. Among dietary factors, high dextrose, low protein, methionine restriction, short-chain fatty acids (butyric acid and lipoic acid), and all-trans-retinoic acid were repeatedly shown to induce FGF21 expression and circulating levels. These effects are usually more pronounced in liver or isolated hepatocytes than in adipose tissue or isolated fat cells. Although peroxisome proliferator-activated receptor α (PPARα) is a key mediator of hepatic FGF21 expression and function, including the regulation of gluconeogenesis, ketogenesis, torpor, and growth inhibition, there is increasing evidence of PPARα-independent transactivation of the FGF21 gene by dietary molecules. FGF21 expression is believed to follow the circadian rhythm and be placed under the control of first order clock-controlled transcription factors, retinoic acid receptor-related orphan receptors (RORs) and nuclear receptors subfamily 1 group D (REV-ERBs), with FGF21 rhythm being anti-phase to REV-ERBs. Key metabolic hormones such as glucagon, insulin, and thyroid hormone have presumed or clearly demonstrated roles in regulating FGF21 transcription and secretion. The control of the FGF21 gene by glucagon and insulin appears more complex than first anticipated. Some discrepancies are noted and will need continued studies. The complexity in assessing the significance of FGF21 gene expression resides in the difficulty to ascertain (i) when transcription results in local or systemic increase of FGF21 protein; (ii) if FGF21 is among the first or second order genes upregulated by physiological, metabolic, and environmental stimuli, or merely an epiphenomenon; and (iii) whether FGF21 may have some adverse effects alongside beneficial outcomes.
Asunto(s)
Factores de Crecimiento de Fibroblastos/genética , Regulación de la Expresión Génica , Animales , Estrés del Retículo Endoplásmico , Factores de Crecimiento de Fibroblastos/metabolismo , Hormonas/genética , Hormonas/metabolismo , Humanos , Hambre , MicroARNs/genética , MicroARNs/metabolismo , Hipernutrición/genética , Hipernutrición/metabolismo , Inanición/genética , Inanición/metabolismoRESUMEN
The Nod-like receptor 3 (NLRP3) inflammasome is an intracellular sensor that sets off the innate immune system in response to microbial-derived and endogenous metabolic danger signals. We previously reported that γ-tocotrienol (γT3) attenuated adipose tissue inflammation and insulin resistance in diet-induced obesity, but the underlying mechanism remained elusive. Here, we investigated the effects of γT3 on NLRP3 inflammasome activation and attendant consequences on type 2 diabetes. γT3 repressed inflammasome activation, caspase-1 cleavage, and interleukin (IL) 1ß secretion in murine macrophages, implicating the inhibition of NLRP3 inflammasome in the anti-inflammatory and antipyroptotic properties of γT3. Furthermore, supplementation of leptin-receptor KO mice with γT3 attenuated immune cell infiltration into adipose tissue, decreased circulating IL-18 levels, preserved pancreatic ß-cells, and improved insulin sensitivity. Mechanistically, γT3 regulated the NLRP3 inflammasome via a two-pronged mechanism: 1) the induction of A20/TNF-α interacting protein 3 leading to the inhibition of the TNF receptor-associated factor 6/nuclear factor κB pathway and 2) the activation of AMP-activated protein kinase/autophagy axis leading to the attenuation of caspase-1 cleavage. Collectively, we demonstrated, for the first time, that γT3 inhibits the NLRP3 inflammasome thereby delaying the progression of type 2 diabetes. This study also provides an insight into the novel therapeutic values of γT3 for treating NLRP3 inflammasome-associated chronic diseases.
Asunto(s)
Proteínas Portadoras/antagonistas & inhibidores , Cromanos/farmacología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Inflamasomas/antagonistas & inhibidores , Vitamina E/análogos & derivados , Proteínas Quinasas Activadas por AMP/inmunología , Tejido Adiposo/efectos de los fármacos , Tejido Adiposo/inmunología , Animales , Proteínas Portadoras/inmunología , Caspasa 1/metabolismo , Cromanos/inmunología , Diabetes Mellitus Tipo 2/inmunología , Inflamasomas/inmunología , Inflamación/tratamiento farmacológico , Inflamación/inmunología , Resistencia a la Insulina , Interleucina-1beta/inmunología , Lipopolisacáridos/farmacología , Macrófagos Peritoneales/efectos de los fármacos , Macrófagos Peritoneales/inmunología , Masculino , Ratones , Ratones Endogámicos NOD , Ratones Noqueados , FN-kappa B/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR , Obesidad/inmunología , Transducción de Señal/efectos de los fármacos , Transducción de Señal/inmunología , Factor de Necrosis Tumoral alfa/inmunología , Vitamina E/inmunología , Vitamina E/farmacologíaRESUMEN
The hormone-like polypeptide, fibroblast growth factor 21 (FGF21), is a major modulator of lipid and glucose metabolism and an exploratory treatment strategy for obesity related metabolic disorders. The costs of recombinant FGF21 and mode of delivery by injection are important constraints to its wide therapeutic use. The stimulation of endogenous FGF21 production through diet is being explored as an alternative approach. To that end, we examined the mechanism(s) by which serum manipulation and lipoic acid (a dietary activator of FGF21) induce FGF21 in human hepatocellular carcinoma HepG2 cells. Serum withdrawal markedly induced FGF21 mRNA levels (88 fold) and FGF21 secreted in the media (19 fold). Lipoic acid induced FGF21 mRNA 7 fold above DMSO-treated control cells and FGF21 secretion 3 fold. These effects were several-fold greater than those of PPARα agonist, Wy14643, which failed to induce FGF21 above and beyond the induction seen with serum withdrawal. The use of transcription inhibitor, actinomycin D, revealed that de novo mRNA synthesis drives FGF21 secretion in response to serum starvation. Four previously unrecognized loci in FGF21 promoter were nucleosome depleted and enriched in acetylated histone H3 revealing their role as transcriptional enhancers and putative transcription factor binding sites. FGF21 did not accumulate to a significant degree in induced HepG2 cells, which secreted FGF21 time dependently in media. We conclude that lipoic acid cell signaling connects with the transcriptional upregulation of FGF21 and it may prove to be a safe and affordable means to stimulate FGF21 production.