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Insulin receptor substrates 1 and 2 (IRS-1 and IRS-2) are signaling adaptor proteins that participate in canonical pathways, where insulin cascade activation occurs, as well as in non-canonical pathways, in which phosphorylation of substrates is carried out by a diverse array of receptors including integrins, cytokines, steroid hormones, and others. IRS proteins are subject to a spectrum of post-translational modifications essential for their activation, encompassing phosphorylation events in distinct tyrosine, serine, and threonine residues. Tyrosine residue phosphorylation is intricately linked to the activation of the insulin receptor cascade and its interaction with SH2 domains within a spectrum of proteins, including PI3K. Conversely, serine residue phosphorylation assumes a different function, serving to attenuate the effects of insulin. In this review, we have identified over 50 serine residues within IRS-1 that have been reported to undergo phosphorylation orchestrated by a spectrum of kinases, thereby engendering the activation or inhibition of different signaling pathways. Furthermore, we delineate the phosphorylation of over 10 distinct tyrosine residues at IRS-1 or IRS-2 in response to insulin, a process essential for signal transduction and the subsequent activation of PI3K.
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Insulin signaling plays an important role in the development and progression of cancer since it is involved in proliferation and migration processes. It has been shown that the A isoform of the insulin receptor (IR-A) is often overexpressed, and its stimulation induces changes in the expression of the insulin receptor substrates (IRS-1 and IRS-2), which are expressed differently in the different types of cancer. We study the participation of the insulin substrates IRS-1 and IRS-2 in the insulin signaling pathway in response to insulin and their involvement in the proliferation and migration of the cervical cancer cell line. Our results showed that under basal conditions, the IR-A isoform was predominantly expressed. Stimulation of HeLa cells with 50 nM insulin led to the phosphorylation of IR-A, showing a statistically significant increase at 30 min (p ≤ 0.05). Stimulation of HeLa cells with insulin induces PI3K and AKT phosphorylation through the activation of IRS2, but not IRS1. While PI3K reached the highest level at 30 min after treatment (p ≤ 0.05), AKT had the highest levels from 15 min (p ≤ 0.05) and remained constant for 6 h. ERK1 and ERK2 expression was also observed, but only ERK2 was phosphorylated in a time-dependent manner, reaching a maximum peak 5 min after insulin stimulation. Although no effect on cell proliferation was observed, insulin stimulation of HeLa cells markedly promoted cell migration.
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The demand for wireless connectivity has grown exponentially over the last years. By 2030 there should be around 17 billion of mobile-connected devices, with monthly data traffic in the order of thousands of exabytes. Although the Fifth Generation (5G) communications systems present far more features than Fourth Generation (4G) systems, they will not be able to serve this growing demand and the requirements of innovative use cases. Therefore, Sixth Generation (6G) Networks are expected to support such massive connectivity and guarantee an increase in performance and quality of service for all users. To deal with such requirements, several technical issues need to be addressed, including novel multiple-antenna technologies. Then, this survey gives a concise review of the main emerging Multiple-Input Multiple-Output (MIMO) technologies for 6G Networks such as massive MIMO (mMIMO), extremely large MIMO (XL-MIMO), Intelligent Reflecting Surfaces (IRS), and Cell-Free mMIMO (CF-mMIMO). Moreover, we present a discussion on how some of the expected key performance indicators (KPIs) of some novel 6G Network use cases can be met with the development of each MIMO technology.
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BACKGROUND AND AIMS: Currently, treatments are being sought to improve the control of type II diabetes mellitus (T2DM), and inulin has been shown to be effective in reducing glucose levels and other metabolic control parameters. These effects on metabolic control may be associated with changes in the epigenetic modulation of genes of the insulin pathway. Therefore, our objective is to determine the effect of agave inulin in metabolic control parameters and in INS and IRS1 genes' methylation in T2DM patients. METHODS: This was a longitudinal experimental study with 67 Mexican participants who received an intervention of inulin agave (10 g daily) for 2 months. The methylation of the INS and IRS1 genes was determined by MSP. RESULTS: For the INS gene, we found a significant decrease in the proportions of T2DM patients with methylated DNA after inulin intervention (p = 0.0001). In contrast, the difference in the proportions of the unmethylated IRS1 gene before and after the inulin intervention was not significant (p = 0.79). On the other hand, we observed changes in the number of T2DM patients' recommended categories for metabolic control depending on the methylation of INS and IRS1 genes before and after treatment with inulin. CONCLUSION: For the first time, we report the modification in the methylation of two genes, INS and IRS1, of the insulin pathway and provide information on the possible relevant role of epigenetics as a key factor in positive changes in metabolic control parameters by inulin intake in T2DM patients.
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Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/genética , Inulina/metabolismo , Metilación , Insulina/metabolismo , México , Proteínas Sustrato del Receptor de Insulina/genética , Proteínas Sustrato del Receptor de Insulina/metabolismoRESUMEN
BACKGROUND: Insulin resistance (IR) is a condition in which the response of organs to insulin is impaired. IR is an early marker of metabolic dysfunction. However, IR also appears in physiological contexts during critical developmental windows. The molecular mechanisms of physiological IR are largely unknown in both sexes. Sexual dimorphism in insulin sensitivity is observed since early stages of development. We propose that during periods of accelerated growth, such as around weaning, at postnatal day 20 (p20) in rats, the kinase S6K1 is overactivated and induces impairment of insulin signaling in its target organs. This work aimed to characterize IR at p20, determine its underlying mechanisms, and identify whether sexual dimorphism in physiological IR occurs during this stage. METHODS: We determined systemic insulin sensitivity through insulin tolerance tests, glucose tolerance tests, and blood glucose and insulin levels under fasting and fed conditions at p20 and adult male and female Wistar rats. Furthermore, we quantified levels of S6K1 phosphorylated at threonine 389 (T389) (active form) and its target IRS1 phosphorylated at serine 1101 (S1101) (inhibited form). In addition, we assessed insulin signal transduction by measuring levels of Akt phosphorylated at serine 473 (S473) (active form) in white adipose tissue and skeletal muscle through western blot. Finally, we determined the presence and function of GLUT4 in the plasma membrane by measuring the glucose uptake of adipocytes. Results were compared using two-way ANOVA (With age and sex as factors) and one-way ANOVA with post hoc Tukey's tests or t-student test in each corresponding case. Statistical significance was considered for P values < 0.05. RESULTS: We found that both male and female p20 rats have elevated levels of glucose and insulin, low systemic insulin sensitivity, and glucose intolerance. We identified sex- and tissue-related differences in the activation of insulin signaling proteins in p20 rats compared to adult rats. CONCLUSIONS: Male and female p20 rats present physiological insulin resistance with differences in the protein activation of insulin signaling. This suggests that S6K1 overactivation and the resulting IRS1 inhibition by phosphorylation at S1101 may modulate to insulin sensitivity in a sex- and tissue-specific manner. Video Abstract.
Insulin regulates the synthesis of carbohydrates, lipids and proteins differently between males, and females. One of its primary functions is maintaining adequate blood glucose levels favoring glucose entry in muscle and adipose tissue after food consumption. Insulin resistance (IR) is a condition in which the response of organs to insulin is impaired. IR is frequently associated with metabolic dysfunction such as inflammation, obesity, or type 2 diabetes. However, physiological IR develops in healthy individuals during periods of rapid growth, pregnancy, or aging by mechanisms not fully understood. We studied the postnatal development, specifically around weaning at postnatal day 20 (p20) of Wistar rats. In previous works, we identified insulin resistance during this period in male rats. This work aimed to characterize IR at p20, determine its underlying mechanisms, and identify whether sexual dimorphism in physiological IR occurs during this stage. We found that p20 rats of both sexes have elevated blood glucose and insulin levels, low systemic insulin sensitivity, and glucose intolerance. We identified differences in insulin-regulated protein activation (S6K1, IRS1, Akt, and GLUT4) between sexes in different tissues and adipose tissue depots. Studying these mechanisms and their differences between males and females is essential to understanding insulin actions and their relationship with the possible development of metabolic diseases in both sexes.
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Resistencia a la Insulina , Animales , Glucemia/metabolismo , Femenino , Glucosa/metabolismo , Insulina/metabolismo , Proteínas Sustrato del Receptor de Insulina/metabolismo , Masculino , Fosforilación , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas , Ratas Wistar , Serina/metabolismo , Caracteres Sexuales , Treonina/metabolismoRESUMEN
Full plastome sequences for land plants have become readily accessible thanks to the development of Next Generation Sequencing (NGS) techniques and powerful bioinformatic tools. Despite this vast amount of genomic data, some lineages remain understudied. Full plastome sequences from the highly diverse (>1,500 spp.) subfamily Tillandsioideae (Bromeliaceae, Poales) have been published for only three (i.e., Guzmania, Tillandsia, and Vriesea) out of 22 currently recognized genera. Here, we focus on core Tillandsioideae, a clade within subfamily Tillandsioideae, and explore the contribution of individual plastid markers and data categories to inform deep divergences of a plastome phylogeny. We generated 37 high quality plastome assemblies and performed a comparative analysis in terms of plastome structure, size, gene content and order, GC content, as well as number and type of repeat motifs. Using the obtained phylogenetic context, we reconstructed the evolution of these plastome attributes and assessed if significant shifts on the evolutionary traits' rates have occurred in the evolution of the core Tillandsioideae. Our results agree with previously published phylogenetic hypotheses based on plastid data, providing stronger statistical support for some recalcitrant nodes. However, phylogenetic discordance with previously published nuclear marker-based hypotheses was found. Several plastid markers that have been consistently used to address phylogenetic relationships within Tillandsioideae were highly informative for the retrieved plastome phylogeny and further loci are here identified as promising additional markers for future studies. New lineage-specific plastome rearrangements were found to support recently adopted taxonomic groups, including large inversions, as well as expansions and contractions of the inverted repeats. Evolutionary trait rate shifts associated with changes in size and GC content of the plastome regions were found across the phylogeny of core Tillandsioideae.
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The plastid genome of flowering plants generally shows conserved structural organization, gene arrangement, and gene content. While structural reorganizations are uncommon, examples have been documented in the literature during the past years. Here we assembled the entire plastome of Bignonia magnifica and compared its structure and gene content with nine other Lamiid plastomes. The plastome of B. magnifica is composed of 183,052 bp and follows the canonical quadripartite structure, synteny, and gene composition of other angiosperms. Exceptionally large inverted repeat (IR) regions are responsible for the uncommon length of the genome. At least four events of IR expansion were observed among the seven Bignoniaceae species compared, suggesting multiple expansions of the IRs over the SC regions in the family. A comparison with 6,231 other complete plastomes of flowering plants available on GenBank revealed that the plastome of B. magnifica is the longest Lamiid plastome described to date. The newly generated plastid genome was used as a source of selected genes. These genes were combined with orthologous regions sampled from other species of Bignoniaceae and all gene alignments concatenated to infer a phylogeny of the family. The tree recovered is consistent with known relationships within the Bignoniaceae.
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Genoma de Plastidios , FilogeniaRESUMEN
BACKGROUND: Understanding local anopheline vector species and their bionomic traits, as well as related human factors, can help combat gaps in protection. METHODS: In San José de Chamanga, Esmeraldas, at the Ecuadorian Pacific coast, anopheline mosquitoes were sampled by both human landing collections (HLCs) and indoor-resting aspirations (IAs) and identified using both morphological and molecular methods. Human behaviour observations (HBOs) (including temporal location and bed net use) were documented during HLCs as well as through community surveys to determine exposure to mosquito bites. A cross-sectional evaluation of Plasmodium falciparum and Plasmodium vivax infections was conducted alongside a malaria questionnaire. RESULTS: Among 222 anopheline specimens captured, based on molecular analysis, 218 were Nyssorhynchus albimanus, 3 Anopheles calderoni (n = 3), and one remains unidentified. Anopheline mean human-biting rate (HBR) outdoors was (13.69), and indoors (3.38) (p = 0.006). No anophelines were documented resting on walls during IAs. HBO-adjusted human landing rates suggested that the highest risk of being bitten was outdoors between 18.00 and 20.00 h. Human behaviour-adjusted biting rates suggest that overall, long-lasting insecticidal bed nets (LLINs) only protected against 13.2% of exposure to bites, with 86.8% of exposure during the night spent outside of bed net protection. The malaria survey found 2/398 individuals positive for asymptomatic P. falciparum infections. The questionnaire reported high (73.4%) bed net use, with low knowledge of malaria. CONCLUSION: The exophagic feeding of anopheline vectors in San Jose de Chamanga, when analysed in conjunction with human behaviour, indicates a clear gap in protection even with high LLIN coverage. The lack of indoor-resting anophelines suggests that indoor residual spraying (IRS) may have limited effect. The presence of asymptomatic infections implies the presence of a human reservoir that may maintain transmission.
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Culicidae/parasitología , Malaria Falciparum/epidemiología , Malaria Vivax/epidemiología , Mosquitos Vectores/parasitología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Anopheles/parasitología , Niño , Preescolar , Estudios Transversales , Ecuador/epidemiología , Femenino , Humanos , Malaria Falciparum/parasitología , Malaria Vivax/parasitología , Masculino , Persona de Mediana Edad , Proyectos Piloto , Plasmodium falciparum/fisiología , Plasmodium vivax/fisiología , Prevalencia , Riesgo , Encuestas y Cuestionarios , Adulto JovenRESUMEN
In cities, the achievement of waste-related legal requirements and the main drivers of Integrated Sustainable Waste Management (ISWM) need adequate indicators and adaptable-to-case tools and strategies. In this work, we combine Material Flow Analysis (MFA) and waste characterizations to develop a mass balance table to design, calculate and analyse indicators related to the formal and informal waste sub-circuits of Tandil, a medium-sized city of the Buenos Aires province (Argentina). Results show that global recovery is very low (2.3% ± 0.16) and mainly driven by the Informal Recovery Sector (IRS). Also, the IRS strategy is more effective, recovering 40% ± 8.0 of its targeted materials from non-household sources. Regarding each material recovery performance, results show significant differences. For paper and board, recovery exceeds 20%. For HDPE, Tetra brik and Ferrous Metals are lower than 1%. In the case of PET and Glass, 9.6 and 9.0% of what is generated in households is recovered, respectively. However, the global recovery rate of each material is different: 2.9% ± 0.4 for PET and 5.5% ± 1.4 for Glass. Our research show that strategies in place are insufficient regarding legislation in force. Even a hypothetically 100% effectiveness in them will account only for 20.9% ± 2.1 of global recovery. Addressing organic waste, therefore, is imperative. Considering the current province law provision of final disposal diversion, accounting for the work of the IRS is key because they recover more waste than the official strategy. Regarding open dumps eradication, we estimate that up to 17% of generated waste is incorrectly final disposed through private skips illegally dumped. A tracking system for skips could avoid this situation.
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Eliminación de Residuos , Administración de Residuos , Argentina , Ciudades , Reciclaje , Residuos SólidosRESUMEN
A pro-inflammatory environment is characteristic of obesity and polycystic ovary syndrome (PCOS). This environment through cytokines secretion negatively affects insulin action. Endometria from women with both conditions (obesity and PCOS) present high TNF-α level and altered insulin signaling. In addition, these patients present reproductive failures that could be associated to an abnormal endometrial function. Here, TNF-α and IL-6 effects on insulin signaling pathway were evaluated. Serum and endometrial IL-6, phospho-IRS1-S270 (inactive form) and phospho-IRS1-Y612 (active form) levels were evaluated in women with: Normal-Weight, Obesity and Obesity-PCOS. In endometrial cells under hyperandrogenic/hyperinsulinic conditions resembling PCOS, it was evaluated IL-6/TNF-α effects on phospho-IRS1-S270, phospho-IRS1-Y612, phospho-AKT-S473 levels, and S6K and JNK activation (IRS1-inactivating molecules). In obesity groups, diminution of IRS1-active form was observed, being more significantly in Obesity-PCOS; whereas, IRS1-inactive form increased in Obesity-PCOS. Serum and endometrial IL-6 were higher in Obesity-groups compared to Normal-Weight. In endometrial cells, TNF-α increases phospho-IRS1-S270, while IL-6 decreases phospho-IRS1-Y612. Importantly, TNF-α and IL-6 promote S6K and JNK activation; TNF-α increases and IL-6 decreases phospho-AKT-S473 levels. Thus, pro-inflammatory cytokines in endometrium could negatively influence insulin signaling by different mechanisms: TNF-α promotes activation of IRS1-inactivating kinases, whereas, IL-6 decreases IRS1 and AKT activation. Moreover, when obesity and PCOS are present the disruption of insulin signaling is aggravated. These effects could explain endometrial abnormal function and reproductive failures observed in women with obesity and PCOS.
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Endometrio/metabolismo , Proteínas Sustrato del Receptor de Insulina/metabolismo , Interleucina-6/farmacología , Obesidad/metabolismo , Síndrome del Ovario Poliquístico/metabolismo , Factor de Necrosis Tumoral alfa/farmacología , Adulto , Línea Celular , Endometrio/efectos de los fármacos , Endometrio/patología , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Interleucina-6/metabolismo , Obesidad/patología , Fosforilación/efectos de los fármacos , Síndrome del Ovario Poliquístico/patología , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Adulto JovenRESUMEN
BACKGROUND: Free fatty acid receptor 1 (FFAR1) is G-protein coupled receptor predominantly expressed in pancreatic ß-cells that is activated by a variety of free fatty acids (FFAs). Once activated, it promotes glucose-stimulated insulin secretion (GSIS). However, increased levels of FFAs lead to lipotoxicity, inducing loss of ß-cell function. FFAR1 plays a key role in the development of type 2 diabetes (T2D), and previous studies have indicated the importance of developing anti-diabetic therapies against FFAR1, although its role in the regulation of ß-cell function remains unclear. The present study investigated the role of FFAR1 under lipotoxic conditions using palmitic acid (PA). The rat insulinoma 1 clone 832/13 (INS-1 832/13) cell line was used as a model as it physiologically resembles native pancreatic ß-cells. Key players of the insulin signaling pathway, such as mTOR, Akt, IRS-1, and the insulin receptor (INSR1ß), were selected as candidates to be analyzed under lipotoxic conditions. RESULTS: We revealed that PA-induced lipotoxicity affected GSIS in INS-1 cells and negatively modulated the activity of both IRS-1 and Akt. Reduced phosphorylation of both IRS-1 S636/639 and Akt S473 was observed, in addition to decreased expression of both INSR1ß and FFAR1. Moreover, transient knockdown of FFAR1 led to a reduction in IRS-1 mRNA expression and an increase in INSR1ß mRNA. Finally, PA affected localization of FFAR1 from the cytoplasm to the perinucleus. CONCLUSIONS: In conclusion, our study suggests a novel regulatory involvement of FFAR1 in crosstalk with mTOR-Akt and IRS-1 signaling in ß-cells under lipotoxic conditions.
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Células Secretoras de Insulina/efectos de los fármacos , Metabolismo de los Lípidos/efectos de los fármacos , Ácido Palmítico/toxicidad , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Animales , Apoptosis , Línea Celular , Células Secretoras de Insulina/metabolismo , Ratas , Transducción de SeñalRESUMEN
The IGF1R/IRS1 signaling is activated in acute lymphoblastic leukemia (ALL) and can be targeted by the pharmacological inhibitors NT157 (IGF1R-IRS1/2 inhibitor) and OSI-906 (IGF1R/IR inhibitor). Here we investigate the cellular and molecular effects of NT157 and OSI-906 in ALL cells. NT157 and OSI-906 treatment reduced viability, proliferation and cell cycle progression in ALL cell lines. Similarly, in primary samples of patients with ALL, both OSI-906 and NT157 reduced viability, but only NT157 induced apoptosis. NT157 and OSI-906 did not show cytotoxicity in primary samples from healthy donor. NT157 and OSI-906 significantly decreased Jurkat cell migration, but did not modulate Namalwa migration. Consistent with the more potent effect of NT157 on cells, NT157 significantly modulated expression of 25 genes related to the MAPK signaling pathway in Jurkat cells, including oncogenes and tumor suppressor genes. Both compounds inhibited mTOR and p70S6K activity, but only NT157 inhibited AKT and 4-EBP1 activation. In summary, in ALL cells, NT157 has cytotoxic activity, whereas OSI-906 is cytostatic. NT157 has a stronger effect on ALL cells, and thus the direct inhibition of IRS1 may be a potential therapeutic target in ALL.
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Antineoplásicos/farmacología , Imidazoles/farmacología , Proteínas Sustrato del Receptor de Insulina/antagonistas & inhibidores , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Fosfatidilinositol 3-Quinasa/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Pirazinas/farmacología , Pirogalol/análogos & derivados , Receptor IGF Tipo 1/antagonistas & inhibidores , Sulfonamidas/farmacología , Serina-Treonina Quinasas TOR/metabolismo , Adulto , Anciano , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Humanos , Proteínas Sustrato del Receptor de Insulina/metabolismo , Células Jurkat , Persona de Mediana Edad , Terapia Molecular Dirigida , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimología , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Pirogalol/farmacología , Receptor IGF Tipo 1/metabolismo , Transducción de Señal , Células Tumorales Cultivadas , Adulto JovenRESUMEN
Conjugated linoleic acid (CLA) constitutes a group of isomers derived from linoleic acid. Diverse studies have suggested that these unsaturated fatty acids have beneficial effects on human health. However, it has also been reported that their consumption can generate alterations in hepatic tissue. Thus, in the present study, we evaluated the effect of two of the major isomers of CLA, cis-9, trans-11-CLA and trans-10, cis-12-CLA, in the regulation of insulin signaling in a hepatic cell model, clone 9 (C9). We found that the two isomers decrease insulin-stimulated phosphorylation of the main proteins involved in insulin signaling, such as Akt at Ser473 and Thr308, the insulin receptor at Tyr1158, IRS-1 at Tyr632, and GSK-3 at Ser9/21. Protein expression, however, was unaffected. Interestingly, both isomers of CLA promoted phosphorylation and activation of PKCε. Inhibition of PKCε activity by a dominant-negative form or knockdown of endogenous PKCε prevented the adverse effects of CLA isomers on insulin-induced Akt phosphorylation. Additionally, we also found that both isomers of CLA increase phosphorylation of IRS-1 at Ser612, a mechanism that probably underlies the inhibition of IRS-1 signaling by PKCε. Using confocal microscopy, we found that both isomers of CLA induced lipid accumulation in C9 cells with the presence of spherical cytosolic vesicles, suggesting their identity as neutral lipid droplets. These findings indicate that cis-9, trans-11-CLA and trans-10, cis-12-CLA isomers could have a significant role in the development of insulin resistance in hepatic C9 cells through IRS-1 serine phosphorylation, PKCε activation, and hepatic lipid accumulation.
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Resistencia a la Insulina , Ácidos Linoleicos Conjugados/metabolismo , Hígado/citología , Proteína Quinasa C-epsilon/metabolismo , Animales , Línea Celular , Activación Enzimática , Insulina/metabolismo , Isomerismo , Hígado/metabolismo , Fosforilación , Proteínas Proto-Oncogénicas c-akt/metabolismo , RatasRESUMEN
BACKGROUND: Free fatty acid receptor 1 (FFAR1) is G-protein coupled receptor predominantly expressed in pancreatic ß-cells that is activated by a variety of free fatty acids (FFAs). Once activated, it promotes glucose-stimulated insulin secretion (GSIS). However, increased levels of FFAs lead to lipotoxicity, inducing loss of ß-cell function. FFAR1 plays a key role in the development of type 2 diabetes (T2D), and previous studies have indicated the importance of developing anti-diabetic therapies against FFAR1, although its role in the regulation of ß-cell function remains unclear. The present study investigated the role of FFAR1 under lipotoxic conditions using palmitic acid (PA). The rat insulinoma 1 clone 832/13 (INS-1 832/13) cell line was used as a model as it physiologically resembles native pancreatic ß-cells. Key players of the insulin signaling pathway, such as mTOR, Akt, IRS-1, and the insulin receptor (INSR1ß), were selected as candidates to be analyzed under lipotoxic conditions. RESULTS: We revealed that PA-induced lipotoxicity affected GSIS in INS-1 cells and negatively modulated the activity of both IRS-1 and Akt. Reduced phosphorylation of both IRS-1 S636/639 and Akt S473 was observed, in addition to decreased expression of both INSR1ß and FFAR1. Moreover, transient knockdown of FFAR1 led to a reduction in IRS-1 mRNA expression and an increase in INSR1ß; mRNA. Finally, PA affected localization of FFAR1 from the cytoplasm to the perinucleus. CONCLUSIONS: In conclusion, our study suggests a novel regulatory involvement of FFAR1 in crosstalk with mTOR-Akt and IRS-1 signaling in ß-cells under lipotoxic conditions.
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Animales , Ratas , Ácido Palmítico/toxicidad , Receptores Acoplados a Proteínas G/metabolismo , Células Secretoras de Insulina/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Metabolismo de los Lípidos/efectos de los fármacos , Serina-Treonina Quinasas TOR/metabolismo , Transducción de Señal , Línea Celular , Apoptosis , Células Secretoras de Insulina/metabolismoRESUMEN
Obesity is accompanied by a low-grade inflammation state, characterized by increased proinflammatory cytokines levels such as tumor necrosis factor alpha (TNFα) and interleukin-1 beta (IL-1ß). In this regard, there exists a lack of studies in hepatic tissue about the role of TNFα receptor 1 (TNFR1) in the context of obesity and insulin resistance during the progression of nonalcoholic fatty liver disease (NAFLD). The aim of this work was to evaluate the effects of high-caloric feeding (HFD) (40% fat, for 16 weeks) on liver inflammation-induced apoptosis, insulin resistance, hepatic lipid accumulation and its progression toward nonalcoholic steatohepatitis (NASH) in TNFR1 knock-out and wild-type mice. Mechanisms involved in HFD-derived IL-1ß release and impairment of insulin signaling are still unknown, so we determined whether IL-1ß affects liver insulin sensitivity and apoptosis through TNFα receptor 1 (TNFR1)-dependent pathways. We showed that knocking out TNFR1 induces an enhanced IL-1ß plasmatic release upon HFD feed. This was correlated with higher hepatic and epididymal white adipose tissue mRNA levels. In vivo and in vitro assays confirmed an impairment in hepatic insulin signaling, in part due to IL-1ß-induced decrease of AKT activation and diminution of IRS1 levels, followed by an increase in inflammation, macrophage (resident and recruited) accumulation, hepatocyte apoptotic process and finally hepatic damage. In addition, TNFR1 KO mice displayed higher levels of pro-fibrogenic markers. TNFR1 signaling disruption upon an HFD leads to an accelerated progression from simple steatosis to a more severe phenotype with many NASH features, pointing out a key role of TNFR1 in NAFLD progression.
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Dieta Alta en Grasa/efectos adversos , Enfermedad del Hígado Graso no Alcohólico/etiología , Receptores Tipo I de Factores de Necrosis Tumoral/metabolismo , Animales , Apoptosis/genética , Insulina/metabolismo , Resistencia a la Insulina , Interleucina-1beta/metabolismo , Hígado/metabolismo , Hígado/patología , Macrófagos/metabolismo , Macrófagos/patología , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Enfermedad del Hígado Graso no Alcohólico/patología , Receptores Tipo I de Factores de Necrosis Tumoral/genética , Transducción de SeñalRESUMEN
Current low participation rates in vector control programmes in Arequipa, Peru complicate the control of Chagas disease. Using focus groups (n = 17 participants) and semi-structured interviews (n = 71) conducted in March and May 2013, respectively, we examined barriers to and motivators of household participation in an indoor residual spray (IRS) campaign that had taken place one year prior in Arequipa. The most common reported barriers to participation were inconvenient spray times due to work obligations, not considering the campaign to be necessary, concerns about secondary health impacts (e.g. allergic reactions to insecticides), and difficulties preparing the home for spraying (e.g. moving heavy furniture). There was also a low perception of risk for contracting Chagas disease that might affect participation. The main motivator to participate was to ensure personal health and well-being. Future IRS campaigns should incorporate more flexible hours, including weekends; provide appropriate educational messages to counter concerns about secondary health effects; incorporate peer educators to increase perceived risk to Chagas in community; obtain support from community members and leaders to build community trust and support for the campaign; and assist individuals in preparing their homes. Enhancing community trust in both the need for the campaign and its operations is key.
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Enfermedad de Chagas/prevención & control , Participación de la Comunidad/psicología , Participación de la Comunidad/estadística & datos numéricos , Vivienda , Insecticidas , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Grupos Focales , Conocimientos, Actitudes y Práctica en Salud , Accesibilidad a los Servicios de Salud , Humanos , Masculino , Persona de Mediana Edad , Motivación , Perú , Investigación Cualitativa , Medición de Riesgo , Adulto JovenRESUMEN
Sepsis survivors frequently develop late cognitive impairment. Because little is known on the mechanisms of post-septic memory deficits, there are no current effective approaches to prevent or treat such symptoms. Here, we subjected mice to severe sepsis induced by cecal ligation and puncture (CLP) and evaluated the sepsis-surviving animals in the open field, novel object recognition (NOR), and step-down inhibitory avoidance (IA) task at different times after surgery. Post-septic mice (30 days post-surgery) failed in the NOR and IA tests but exhibited normal performance when re-evaluated 45 days after surgery. Cognitive impairment in post-septic mice was accompanied by reduced hippocampal levels of proteins involved in synaptic plasticity, including synaptophysin, cAMP response element-binding protein (CREB), CREB phosphorylated at serine residue 133 (CREBpSer133), and GluA1 phosphorylated at serine residue 845 (GluA1pSer845). Expression of tumor necrosis factor α (TNF-α) was increased and brain insulin signaling was disrupted, as indicated by increased hippocampal IRS-1 phosphorylation at serine 636 (IRS-1pSer636) and decreased phosphorylation of IRS-1 at tyrosine 465 (IRS-1pTyr465), in the hippocampus 30 days after CLP. Phosphorylation of Akt at serine 473 (AktpSer473) and of GSK3 at serine 9 (GSK3ßpSer9) were also decreased in hippocampi of post-septic animals, further indicating that brain insulin signaling is disrupted by sepsis. We then treated post-septic mice with liraglutide, a GLP-1 receptor agonist with insulinotropic activity, or TDZD-8, a GSK3ß inhibitor, which rescued NOR memory. In conclusion, these results establish that hippocampal inflammation and disrupted insulin signaling are induced by sepsis and are linked to late memory impairment in sepsis survivors.
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Encéfalo/metabolismo , Disfunción Cognitiva/metabolismo , Insulina/metabolismo , Sepsis/metabolismo , Transducción de Señal/fisiología , Animales , Encéfalo/patología , Disfunción Cognitiva/etiología , Disfunción Cognitiva/patología , Conducta Exploratoria/fisiología , Masculino , Ratones , Sepsis/complicaciones , Sepsis/patologíaRESUMEN
Insulin-like growth factor 1 (IGF1) and its receptor IGF1R regulate normal cell growth and contribute to cell transformation through activation of downstream signaling pathways. In fibroblast cells, insulin receptor substrate 1 (IRS1), through IGF1 signaling, was found to be the key protein for nuclear translocation of ß-catenin and MYC transcription activation. We herein investigated the IRS1/ß-catenin axis in acute lymphoblastic leukemia (ALL) cells. Samples were obtained from 45 patients with ALL and 13 healthy donors. ALL cell lines were used. Gene expression was measured by quantitative PCR. Protein expression, associations, and cellular localization were evaluated by immunoprecipitation, subcellular fractionation, and confocal microscopy. Cells were submitted to IGF1 stimulation and/or IGF1R pharmacological inhibition (OSI-906). IRS1, ß-catenin, and MYC mRNA expression were significantly elevated in ALL patients, compared to normal controls. MYC mRNA expression positively correlated with ß-catenin and IRS1. Increased age and MYC expression negatively affected overall survival by univariate analysis. Total and phospho-IGF1R and IRS1, MYC and ß-catenin protein expression were higher in ALL cells, compared to normal peripheral blood mononuclear cells (PBMC). IRS1 and ß-catenin were found to be colocalized in the nuclei and the cytoplasm of ALL cell lines, whereas both proteins were only slightly detected in the cytoplasm of normal PBMC. In Jurkat cells, a constitutive IRS1 and ß-catenin protein interaction were observed; OSI-906 treatment decreased IGF1R tyrosine phosphorylation, IRS1 expression and phosphorylation, nuclear translocation of ß-catenin, IRS1 and ß-catenin association, and MYC protein expression. In conclusion, the IRS1/ß-catenin axis is activated in ALL cells. J. Cell. Biochem. 118: 1774-1781, 2017. © 2016 Wiley Periodicals, Inc.
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Proteínas Sustrato del Receptor de Insulina/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , beta Catenina/genética , Transporte Activo de Núcleo Celular/genética , Transporte Activo de Núcleo Celular/fisiología , Adolescente , Adulto , Western Blotting , Humanos , Imidazoles/farmacología , Inmunoprecipitación , Proteínas Sustrato del Receptor de Insulina/metabolismo , Microscopía Confocal , Persona de Mediana Edad , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-myc/metabolismo , Pirazinas/farmacología , ARN Mensajero/genética , Receptor IGF Tipo 1 , Receptores de Somatomedina/genética , Receptores de Somatomedina/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Adulto Joven , beta Catenina/metabolismoRESUMEN
The recurrent V617F mutation in JAK2 (JAK2V617F) has emerged as the primary contributor to the pathogenesis of myeloproliferative neoplasms (MPN). However, the lack of complete response in most patients treated with the JAK1/2 inhibitor, ruxolitinib, indicates the need for identifying pathways that cooperate with JAK2. Activated JAK2 was found to be associated with the insulin receptor substrate 2 (IRS2) in non-hematological cells. We identified JAK2/IRS2 binding in JAK2V617F HEL cells, but not in the JAK2WT U937 cell line. In HEL cells, IRS2 silencing decreased STAT5 phosphorylation, reduced cell viability and increased apoptosis; these effects were enhanced when IRS2 silencing was combined with ruxolitinib. In U937 cells, IRS2 silencing neither reduced cell viability nor induced apoptosis. IRS1/2 pharmacological inhibition in primary MPN samples reduced cell viability in JAK2V617F-positive but not JAK2WT specimens; combination with ruxolitinib had additive effects. IRS2 expression was significantly higher in CD34+ cells from essential thrombocythemia patients compared to healthy donors, and in JAK2V617F MPN patients when compared to JAK2WT. Our data indicate that IRS2 is a binding partner of JAK2V617F in MPN. IRS2 contributes to increased cell viability and reduced apoptosis in JAK2-mutated cells. Combined pharmacological inhibition of IRS2 and JAK2 may have a potential clinical application in MPN.
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Apoptosis/efectos de los fármacos , Proteínas Sustrato del Receptor de Insulina/antagonistas & inhibidores , Janus Quinasa 2/genética , Mutación/genética , Trastornos Mieloproliferativos/patología , Pirazoles/farmacología , Adulto , Anciano , Anciano de 80 o más Años , Western Blotting , Estudios de Casos y Controles , Proliferación Celular/efectos de los fármacos , Femenino , Técnica del Anticuerpo Fluorescente , Estudios de Seguimiento , Silenciador del Gen , Humanos , Técnicas para Inmunoenzimas , Inmunoprecipitación , Proteínas Sustrato del Receptor de Insulina/genética , Proteínas Sustrato del Receptor de Insulina/metabolismo , Janus Quinasa 2/metabolismo , Masculino , Persona de Mediana Edad , Trastornos Mieloproliferativos/tratamiento farmacológico , Trastornos Mieloproliferativos/genética , Estadificación de Neoplasias , Nitrilos , Pronóstico , Pirimidinas , ARN Mensajero/genética , ARN Interferente Pequeño/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto , Adulto JovenRESUMEN
Dengue is an important public health problem in the Amazon area of Peru, resulting in significant morbidity each year. As in other areas of the world, ultra-low volume (ULV) application of insecticides is the main strategy to reduce adult populations of the dengue vector Aedes aegypti, despite growing evidence of its limitations as a single control method. This study investigated the efficacy of deltamethrin S.C. applied through indoor residual spraying (IRS) of dwellings in reducing A. aegypti populations. The residual effect of the insecticide was tested by monthly bioassays on the three most common indoor surfaces found in the Amazon area: painted wood, unpainted wood and brick. The results showed that in an area with moderate levels of A. aegypti infestation, IRS dramatically reduced all immature indices the first week after deltamethrin IRS application and the adult index from 18.5 to 3.1, four weeks after intervention (p<0.05). Even though housing conditions facilitated reinfestation with A. aegypti (100% of the houses have open roof eaves, 31.5% lack sewage systems, and 60.4% collected rain in open containers), indices remained low compared to baseline 16 weeks after insecticide application. Bioassays showed that deltamethrin S.C. caused mortalities >80% 8 weeks after application on all types of surfaces. The residual effect of the insecticide was greater on brick than on wooden walls (p<0.05). Our results demonstrate that IRS can have both an immediate and sustained effect on reducing adult and immature A. aegypti populations and should be considered as an adult mosquito control strategy by dengue vector control programs.