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Acceso Abierto Corrosión localizada del acero inoxidable austenítico en medio de cultivo celular y evaluación de la citotoxicidad de los iones liberados(2021) Parisi, Julieta Marcia; Castrogiovanni, Daniel; Grau, Jorge Enrique; Gregorutti, Ricardo Walter; Elsner, Cecilia InésEl acero inoxidable austenítico ASTM F745 ha sido sometido a corrosión localizada en medio de cultivo celular y solución acuosa de NaCl, cuyas concentraciones de cloruro fueron 4413,2 mg L-1 y 5423,1 mg L-1, respectivamente. Se ha observado que la susceptibilidad a la corrosión localizada fue menor en el medio de cultivo debido a su menor contenido de cloruros. El Fe fue el metal más liberado en ambos medios durante el proceso de corrosión. Las concentraciones fueron 0,570 mg L-1 en la solución acuosa de NaCl y 0,480 mg L-1 en el medio de cultivo. Las concentraciones de Cr y Mo fueron similares en ambos medios, habiendo sido 0,040 mg L-1 y 0,010 mg L-1, respectivamente, mientras que Ni solo se detectó en la solución acuosa de NaCl, 0,100 mg L-1. Estas concentraciones de iones liberados no provocaron efectos citotóxicos en células similares a osteoblastos. - Artículo
Acceso Abierto Identification of llama KRTAP7-1 and KRTAP8-1 fiber genes and polymorphism screening(2019) Daverio, Maria Silvana; Anello, Melina; Alcolea Ersinger, Victoria; Álvarez, Solange; Frank, Eduardo; Vidal Rioja, Lidia Beatriz; Di Rocco, FlorenciaKeratin-associated proteins (KAP) are one of the main structural components of hair fiber. Within this protein group, high glycine tyrosine (HGT)-KAP play a crucial role in the definition of their physical-mechanical properties. Polymorphisms in HGT genes have been associated with the variation of different wool traits in sheeps and goats. The Argentine llama is a fiber-producing animal which is valued by the textile industry. However, the genes encoding for fiber proteins have not yet been identified in this species. Here, we focus on studying the HGT-KRTAP7-1 and KRTAP8-1 genes and their variation using the High Resolution Melting (HRM) technique in a sample of 117 llamas. Four single nucleotide polymorphisms (SNPs) were detected in KRTAP7-1, two of which were non-synonymous substitutions leading to amino acid changes in the protein. Of the 5 polymorphisms identified in KRTAP8-1, c.1-5A > G was located in the Kozak sequence, known to regulate protein synthesis level. The other four, two SNPs and one double nucleotide polymorphism (DNP), were found in the coding region and produced three amino acid replacement: c.43 T > C and c.45C > A (p.Y15Q), c.46 G > T (p.G16W) and c.173 A > G (p.Y58C). In summary, most of the polymorphisms found in both KRTAP7-1 and KRTAP8-1 genes produce non-conservative amino acid changes involving tyrosine and glycine residues, which are essential to maintain HGT protein properties. Therefore, these mutations as well as the regulatory SNP here identified could modify the fiber characteristics. We discuss the possible impact of these polymorphisms on KAP7-1 and KAP8-1 structure and/or interaction with other fiber proteins. - Artículo
Acceso Abierto Characterization and expression analysis of KIT and MITF-M genes in llamas and their relation to white coat color(2019) Anello, Melina; Daverio, Maria Silvana; Silbestro, Miguel Osvaldo; Vidal Rioja, Lidia Beatriz; Di Rocco, FlorenciaThe llama (Lama glama) is a fiber-producing species that presents a wide range of coat colors, among which white is one of the most important for the textile industry. However, there is little information about the molecular mechanisms that control the white phenotype in this species. In domestic mammals, a white coat is usually produced by mutations in the KIT proto-oncogene receptor tyrosine kinase (KIT) and microphthalmia-associated transcription factor (MITF) genes. In this work we have sequenced and described the coding regions of KIT and MITF-M, the melanocyte-specific isoform, and the two transcriptional variants MITF-M( ) and MITF-M(+). Moreover, we studied the expression of these genes in the skin of white and colored llamas. Although no variants were revealed to be associated with white coat color, significant differences between phenotypes were observed in the expression levels of KIT and MITF-M. Interestingly, white llamas expressed less MITF-M(+) than did colored ones, which is consistent with a consequent reduction in the synthesis of melanin. Even though our results indicate that downregulation of KIT and MITF-M expression is involved in white phenotype production in llamas, the causative gene of white coat color remains unknown. - Artículo
Acceso Abierto TYR Gene in Llamas: Polymorphisms and Expression Study in Different Color Phenotypes(2019) Anello, Melina; Daverio, Maria Silvana; Fernández, Estefania; Daverio, Maria Silvana; Vidal Rioja, Lidia Beatriz; Di Rocco, FlorenciaTyrosinase, encoded by TYR gene, is an enzyme that plays a major role in mammalian pigmentation. It catalyzes the oxidation of L-dihydroxy-phenylalanine (DOPA) to DOPA quinone, a precursor of both types of melanin: eumelanin and pheomelanin. TYR is commonly known as the albino locus since mutations in this gene result in albinism in several species. However, many other TYR mutations have been found to cause diluted phenotypes, like the Himalayan or chinchilla phenotypes in mice. The llama (Lama glama) presents a wide variety of coat colors ranging from non-diluted phenotypes (eumelanic and pheomelanic), through different degrees of dilution, to white. To investigate the possible contribution of TYR gene to coat color variation in llamas, we sequenced TYR exons and their flanking regions and genotyped animals with diluted, non-diluted, and white coat, including three blue-eyed white individuals. Moreover, we analyzed mRNA expression levels in skin biopsies by qPCR. TYR coding region presented nine SNPs, of which three were non-synonymous, c.428A > G, c.859G > T, and c.1490G > T. We also identified seven polymorphisms in non-coding regions, including two microsatellites, an homopolymeric repeat, and five SNPs: one in the promoter region (c.1-26C > T), two in the 30 -UTR, and two flanking the exons. Although no complete association was found between coat color and SNPs, c.1-26C > T was partially associated to diluted phenotypes. Additionally, the frequency of the G allele from c.428A > G was significantly higher in white compared to non-diluted. Results from qPCR showed that expression levels of TYR in white llamas were significantly lower (p < 0.05) than those in diluted and non-diluted phenotypes. Screening for variation in regulatory regions of TYR did not reveal polymorphisms that explain such differences. However, data from this study showed that TYR expression levels play a role in llama pigmentation. - Artículo
Acceso Abierto NAT2 and oral clefts: evaluation of genetic risk and the relative importance of embryo and maternal genotypes(2019) Santos, María Rita; Campaña, Hebe Edith; Jurado Medina, Laura Smeldy; Sala, Camila; Muzzio, Marina; López-Camelo, Jorge Santiago; Bailliet, GracielaNon-syndromic cleft lip with or without cleft palate (NSCLP) is a congenital malformation that shows the characteristics of a multifactorial pathology. In order to describe the genetic predisposition to this disorder, NAT genes were analyzed with special interest since they codify for N-acetyltransferases, the enzymes responsible for the biotransformation of arylamines, hydrazine drugs and a great number of toxins and carcinogens present in diet, cigarette smoke and the environment. The allelic transmission of NAT2 that determines the slow acetylator phenotype in 174 trios (case-mother/father) from ECLAMC (Latin American Collaborative Study of Congenital Malformations) maternities in Argentina was evaluated. The *4, *5B, *6, and *7 variants by PCR-RFLP were analyzed. A higher risk for the 5B*5B* genotypes (OR=2. 24; p=0.050) was found, at the expense of the cases from Patagonia, without the influence of the maternal genotype. - Documento de conferencia
Acceso Abierto Variabilidad genética del color del iris en la población de la provincia de Buenos Aires(2018) Catanesi, Cecilia Inés; Hohl, Diana; Bezus, Brenda; Ratowiecki, JuliaEl color del iris es un rasgo fenotípico conspicuo de los humanos, que presenta variación entre individuos, en una gama que va del azul claro al marrón oscuro, y entre poblaciones de distintas partes del mundo. De origen poligénico, presenta escasa influencia del entorno, estando sujeto sólo a ciertos cambios que dependen de la edad del individuo y ciertas patologías. Los estudios científicos han identificado una serie de genes involucrados en la determinación del color de los ojos. Entre los principales genes se encuentran HERC2, IRF4, SLC24A4, SLC45A2 y TYR, los cuales presentan variaciones de un nucleótido (SNP, por Single Nucleotide Polymorphism) y se han tenido en cuenta para el desarrollo de un sistema de predicción del color en poblaciones europeas. La importancia de estudiar la variación genética de este rasgo reside en su aplicación potencial en el área de genética forense, como una herramienta de predicción de características externamente visibles. Dado que en Argentina y otros países de Latinoamérica, la determinación genética de esta característica ha sido escasamente estudiada, el proyecto apunta a describir la variación genotípica y fenotípica relacionada con el color del iris en la población de la provincia de Buenos Aires y evaluar la aplicabilidad de los métodos de tipificación que son utilizados en otras poblaciones del mundo. - Artículo
Acceso Abierto Genetic Differentiation of North-East Argentina Populations Based on 30 Binary X Chromosome Markers(2018) Di Santo Meztler, Gabriela Paula; del Palacio, Santiago; Esteban, María E.; Armoa, Isaías; Argüelles, Carina Francisca; Catanesi, Cecilia InésAlu insertions, INDELs, and SNPs in the X chromosome can be useful not only for revealing relationships among populations but also for identification purposes. We present data of 10 Alu insertions, 5 INDELs, and 15 SNPs of X-chromosome from three Argentinian north-east cities in order to gain insight into the genetic diversity of the X chromosome within this region of the country. Data from 198 unrelated individuals belonging to Posadas, Corrientes, and Eldorado cities were genotyped for Ya5DP62, Yb8DP49, Ya5DP3, Ya5NBC37, Ya5DP77, Ya5NBC491, Ya5DP4, Ya5DP13, Yb8NBC634, and Yb8NBC102 Alu insertions, for MID193, MID1705, MID3754, MID3756 and MID1540 Indels and for rs6639398, rs5986751, rs5964206, rs9781645, rs2209420, rs1299087, rs318173, rs933315, rs1991961, rs4825889, rs1781116, rs1937193, rs1781104, rs149910, and rs652 SNPs. No deviations fromHardy-Weinberg equilibrium were observed for Posadas and Corrientes. However, Eldorado showed significant values, and it was found to have an internal substructuring with two groups of different origin, one showing higher similarity with European countries, and the other with more similarities to Posadas and Corrientes. Fst pairwise genetic distances emerged for some markers among the studied populations and also between our data and those from other countries and continents. Of particular interest, Alu insertions demonstrated the most differences, and could be of use in ancestry studies for these populations, while INDELs and SNPs variation were informative for differentiation within the country. - Artículo
Embargado Polymorphisms in MC1R and ASIP genes and their association withcoat color phenotypes in llamas (Lama glama)(2016) Daverio, Maria Silvana; Rigalt, Francisco; Romero, Sandra; Vidal Rioja, Lidia Beatriz; Di Rocco, FlorenciaThe melanocortin 1-receptor (MC1R) and the agouti signaling protein (ASIP) are the major genes control-ling the type and location of pigments produced in mammals. In recent years, polymorphisms in thesegenes have been associated with coat color variation in a number of species. Llamas (Lama glama) arecharacterized by a great diversity of coat colors. However, the genetic basis of coat color determinationis still unknown. Here, we sequenced the MC1R and ASIP genes in llamas and studied the associationbetween the polymorphisms identified and the coat color. Sequence analysis revealed ten nonsynony-mous single nucleotide polymorphisms in the MC1R gene. Three main haplotypes were identified, none ofwhich were completely associated to a particular color phenotype. However, significant association wasdetected between the MC1R*1 haplotype and the presence of pigmented coat (P < 0.0001). Compared tothe wild allele, MC1R*1 carried two amino acid substitutions, p.G126S and p.V87 M. This last replacementoccurs at a highly conserved residue among mammals and the same substitution has been previouslyassociated to melanic phenotypes in avian species. Furthermore, two polymorphisms in ASIP exon 4, a57 bp deletion (c.325 381del) and c.292C > T that are both predicted to have a deleterious effect on theprotein, were found in homozygous state or combined in most llamas with eumelanic coat. - Artículo
Embargado Molecular characterization of the llama FGF5 gene and identification of putative loss of function mutations(2017) Daverio, M.S.; Vidal-Rioja, L.; Frank, E. N.; Di Rocco, FlorenciaLlama, the most numerous domestic camelid in Argentina, has good fiber-production ability. Although a few genes related to other productive traits have been characterized, the molecular genetic basis of fiber growth control in camelids is still poorly understood. Fibroblast growth factor 5 (FGF5) is a secreted signaling protein that controls hair growth in humans and other mammals. Mutations in the FGF5 gene have been associated with long-hair phenotypes in several species. Here, we sequenced the llama FGF5 gene, which consists of three exons encoding 813bp. cDNA analysis from hair follicles revealed the expression of two FGF5 alternative spliced transcripts, in one of which exon 2 is absent. DNA variation analysis showed four polymorphisms in the coding region: a synonymous SNP (c.210A>G), a single base deletion (c.348delA), a 12-bp insertion (c.351_352insCATATAACATAG) and a non-sense mutation (c.499C>T). The deletion was always found together with the insertion forming a haplotype and producing a putative truncated protein of 123 amino acids. The c.499C>T mutation also leads to a premature stop codon at position 168. In both cases, critical functional domains of FGF5, including one heparin binding site, are lost. All animals analyzed were homozygous for one of the deleterious mutations or compound heterozygous for both (i.e. c.348delA, c.351_352insCATATAACATAG/c.499T). Sequencing of guanaco samples showed that the FGF5 gene encodes a full-length 270-amino acid protein. These results suggest that FGF5 is likely functional in short-haired wild species and non-functional in the domestic fiber-producing species, the llama. - Artículo
Acceso Abierto Linajes paternos del Gran Chaco, un abordaje desde el ADN(2014) Jurado Medina, Laura Smeldy; Ramallo, Virginia; Calandra, Horacio; Lamenza, Guillermo; Braunstein, José; Salceda, Susana; Bailliet, GracielaLa región no recombinante del cromosoma Y ha sido exitosamente utilizada para reconocer la estructura genética de los linajes paternos de poblaciones humanas. Este trabajo se integra al proyecto multidisciplinario “De las historias étnicas a la prehistoria en el Gran Chaco”, involucra el estudio de individuos de diversa filiación étnica y se propone reconocer la estructuración en la fracción nativa de los linajes paternos. Tal información dará cuenta de la dinámica poblacional y de los patrones de distribución aportando así, elementos clarificadores de la compleja configuración de las poblaciones chaqueñas. En los 118 individuos analizados se identificaron 82 linajes, de los cuales 22% estuvieron presentes en más de un individuo dentro de una población o entre poblaciones, en ocasiones distantes geográficamente. El coeficiente de diferenciación entre poblaciones fue el mayor encontrado (FST = 21%) en linajes autóctonos de poblaciones de Argentina (FST = 3%). La red de haplotipos demuestra que los linajes presentan una subestructuración en 3 ramas principales, en cada una de las mismas participan linajes de distintos grupos, reflejando la ausencia de aislamiento entre los mismos y planteando interesantes interrogantes a la luz de los datos arqueológicos y etnolingüísticos. - Artículo
Embargado Genetic diversity and conservation status of managed vicuña (Vicugna vicugna) populations in Argentina(Springer International Publishing, 2016) Anello, Melina; Daverio, María Silvana; Romero, S. R.; Rigalt, F.; Silbestro, Miriam Beatriz; Vidal Rioja, Lidia Beatriz; Di Rocco, FlorenciaThe vicuña (Vicugna vicugna) was indiscriminately hunted for more than 400 years and, by the end of 1960s, it was seriously endangered. At that time, a captive breeding program was initiated in Argentina by the National Institute of Agricultural Technology (INTA) with the aim of preserving the species. Nowadays, vicuñas are managed in captivity and in the wild to obtain their valuable fiber. The current genetic status of Argentinean vicuña populations is virtually unknown. Using mitochondrial DNA and microsatellite markers, we assessed levels of genetic diversity of vicuñapopulations managed in the wild and compared it with a captive population from INTA. Furthermore, we examined levels of genetic structure and evidence for historical bottlenecks. Overall, all populations revealed high genetic variability with no signs of inbreeding. Levels of genetic diversity between captive and wild populations were not significantly different, although the captive population showed the lowest estimates of allelic richness, number of mitochondrial haplotypes, and haplotype diversity. Significant genetic differentiation at microsatellite markers was found between free-living populations from Jujuy and Catamarca provinces. Moreover, microsatellite data also revealed genetic structure within the Catamarca management area. Genetic signatures of past bottlenecks were detected in wild populations by the Garza Williamson test. Results from this study are discussed in relation to the conservation and management of the species. - Artículo
Acceso Abierto Effect of Pioglitazone on the Fructose-Induced Abdominal Adipose Tissue Dysfunction(Hindawi Publishing Corporation, 2012) Alzamendi, Ana; Giovambattista, Andrés; Garcia, María Elisa; Rebolledo, Oscar R.; Gagliardino, Juan José; Spinedi, EduardoAim. To test the potential role of PPARγ in the endocrine abdominal tissue dysfunction induced by feeding normal rats with a fructose rich diet (FRD) during three weeks. Methodology. Adult normal male rats received a standard commercial diet (CD) or FRD, (10% in drinking water) without or with pioglitazone (PIO) (i.p. 0.25mg/Kg BW/day; CD-PIO and FRD-PIO). Thereafter, we measured circulating metabolic, endocrine, and oxidative stress (OS) markers, abdominal adipose tissue (AAT) mass, leptin (LEP) and plasminogen activator inhibitor-1 (PAI-1) tissue content/expression, and leptin release by isolated adipocytes incubated with different concentrations of insulin. Results. Plasma glucose, insulin, triglyceride, TBARS, LEP, and PAI-1 levels were higher in FRD rats; PIO coadministration fully prevented all these increments. AAT adipocytes from FRD rats were larger, secreted a higher amount of LEP, and displayed decreased sensitivity to insulin stimulation; these effects were significantly ameliorated by PIO. Whereas AAT LEP and PAI-1 (mRNA) concentrations increased significantly in FRD rats, those of insulin-receptor-substrate- (IRS-) 1 and IRS-2 were reduced. PIO coadministration prevented FRD effects on LEP, PAI-1, and IRS-2 (fully) and IRS-1 (partially) mRNAs in AAT. Conclusion. PPARγ would play a relevant role in the development of the FRD-induced metabolicendocrine dysfunction. - Artículo
Acceso Abierto Oral Metformin Treatment Prevents Enhanced Insulin Demand and Placental Dysfunction in the Pregnant Rat Fed a Fructose-Rich Diet(Hindawi Publishing Corporation, 2012) Alzamendi, Ana; Del Zotto, Héctor; Castrogiovanni, Daniel; Romero, José; Giovambattista, Andrés; Spinedi, EduardoThe intake of a fructose-rich diet (FRD) in the normal female rat induces features similar to those observed in the human metabolic syndrome phenotype. We studied the impact of FRD administration to mothers on pregnancy outcome. On gestational day (Gd) zero rats were assigned to either group: ad libitum drinking tap water alone (normal diet, ND) or containing fructose (10% w/vol; FRD) through pregnancy; all rats were fed a Purina chow diet ad libitum ND and FRD rats were daily cotreated or not with metformin (60 mg/Kg/day oral; ND + MF and FRD + MF) and submitted to a high glucose load test on Gd 14. Additionally, placentas from different groups were studied on Gd 20. Data indicated that: (1) although FRD rats well tolerated glucose overload, their circulating levels of insulin were significantly higher than in ND rats; (2) the mesometrial triangle blood vessel area was significantly lower in placentas from FRD than ND dams; (3) the detrimental effects of FRD administration to mothers were ameliorated by metformin cotreatment. Our study suggests that excessive intake of fructose during pregnancy enhanced the risk for developing gestational diabetes and subsequent preeclampsia, and that metformin prevented the poor pregnancy outcome induced by FRD. - Revisión
Acceso Abierto Is Ghrelin Synthesized in the Central Nervous System?(MDPI (Multidisciplinary Digital Publishing Institute), 2017) Cabral, Agustina; López Soto, Eduardo Javier; Epelbaum, Jacques; Perelló, MarioGhrelin is an octanoylated peptide that acts via its specific receptor, the growth hormone secretagogue receptor type 1a (GHSR-1a), and regulates a vast variety of physiological functions. It is well established that ghrelin is predominantly synthesized by a distinct population of endocrine cells located within the gastric oxyntic mucosa. In addition, some studies have reported that ghrelin could also be synthesized in some brain regions, such as the hypothalamus. However, evidences of neuronal production of ghrelin have been inconsistent and, as a consequence, it is still as a matter of debate if ghrelin can be centrally produced. Here, we provide a comprehensive review and discussion of the data supporting, or not, the notion that the mammalian central nervous system can synthetize ghrelin. We conclude that no irrefutable and reproducible evidence exists supporting the notion that ghrelin is synthetized, at physiologically relevant levels, in the central nervous system of adult mammals. - Artículo
Acceso Abierto Fructose Rich Diet-Induced High Plasminogen Activator Inhibitor-1 (PAI-1) Production in the Adult Female Rat: Protective Effect of Progesterone(MDPI (Multidisciplinary Digital Publishing Institute), 2012) Castrogiovanni, Daniel; Alzamendi, Ana; Ongaro, Luisina; Giovambattista, Andrés; Gaillard, Rolf; Spinedi, EduardoThe effect of progesterone (P4) on fructose rich diet (FRD) intake-induced metabolic, endocrine and parametrial adipose tissue (PMAT) dysfunctions was studied in the adult female rat. Sixty day-old rats were i.m. treated with oil alone (control, CT) or containing P4 (12 mg/kg). Rats ate Purina chow-diet ad libitum throughout the entire experiment and, between 100 and 120 days of age drank ad libitum tap water alone (normal diet; CT-ND and P4-ND) or containing fructose (10% w/v; CT-FRD and P4-FRD). At age 120 days, animals were subjected to a glucose tolerance test or decapitated. Plasma concentrations of various biomarkers and PMAT gene abundance were monitored. P4-ND (vs. CT-ND) rats showed elevated circulating levels of lipids. CT-FRD rats displayed high (vs. CT-ND) plasma concentrations of lipids, leptin, adiponectin and plasminogen activator inhibitor-1 (PAI-1). Lipidemia and adiponectinemia were high (vs. P4-ND) in P4-FRD rats. Although P4 failed to prevent FRD-induced hyperleptinemia, it was fully protective on FRD-enhanced plasma PAI-1 levels. PMAT leptin and adiponectin mRNAs were high in CT-FRD and P4-FRD rats. While FRD enhanced PMAT PAI-1 mRNA abundance in CT rats, this effect was absent in P4 rats. Our study supports that a preceding P4-enriched milieu prevented the enhanced prothrombotic risk induced by FRD-elicited high PAI-1 production. - Artículo
Acceso Abierto Deleterious Metabolic Effects of High Fructose Intake: The Preventive Effect of Lactobacillus kefiri Administration(MDPI (Multidisciplinary Digital Publishing Institute), 2017) Zubiría, Guillermina; Gambaro, Sabrina Eliana; Rey, María Amanda; Carasi, Paula; Serradell, María de los Ángeles; Giovambattista, AndrésModern lifestyle and diets have been associated with metabolic disorders and an imbalance in the normal gut microbiota. Probiotics are widely known for their health beneficial properties targeting the gut microbial ecosystem. The aim of our study was to evaluate the preventive effect of Lactobacillus kefiri (L. kefiri) administration in a fructose-rich diet (FRD) mice model. Mice were provided with tap water or fructose-added (20% w/v) drinking water supplemented or not with L. kefiri. Results showed that probiotic administration prevented weight gain and epidydimal adipose tissue (EAT) expansion, with partial reversion of the adipocyte hypertrophy developed by FRD. Moreover, the probiotic prevented the increase of plasma triglycerides and leptin, together with the liver triglyceride content. Leptin adipocyte secretion was also improved by L. kefiri, being able to respond to an insulin stimulus. Glucose intolerance was partially prevented by L. kefiri treatment (GTT) and local inflammation (TNFα; IL1β; IL6 and INFγ) was completely inhibited in EAT. L. kefiri supplementation generated an impact on gut microbiota composition, changing Bacteroidetes and Firmicutes profiles. Overall, our results indicate that the administration of probiotics prevents the deleterious effects of FRD intake and should therefore be promoted to improve metabolic disorders. - Artículo
Acceso Abierto Relationship between the Balance of Hypertrophic/Hyperplastic Adipose Tissue Expansion and the Metabolic Profile in a High Glucocorticoids Model(2016) Zubiría, Guillermina; Alzamendi, Ana; Moreno, Griselda; Portales, Andrea Estefanía; Castrogiovanni, Daniel; Spinedi, Eduardo; Giovambattista, AndrésAdipose tissue (AT) expansion is the result of two processes: hyperplasia and hypertrophy; and both, directly or indirectly, depend on the adipogenic potential of adipocyte precursor cells (APCs). Glucocorticoids (GCs) have a potent stimulatory effect on terminal adipogenesis; while their effects on early stages of adipogenesis are largely unknown. In the present work, we study, in a model of high GC levels, the adipogenic potential of APCs from retroperitoneal AT (RPAT) and its relationship with RPAT mass expansion. We employed a model of hyper-adiposity (30- and 60-day-old rats) due to high endogenous GC levels induced by neonatal treatment with L-monosodium glutamate (MSG).We found that the RPAT APCs from 30-day-old MSG rats showed an increased adipogenic capacity, depending on the APCs’ competency, but not in their number. Analyses of RPAT adipocyte diameter revealed an increase in cell size, regardless of the rat age, indicating the prevalence of a hypertrophic process. Moreover, functional RPAT alterations worsened in 60-day-old rats, suggesting that the hyperplastic AT expansion found in 30-day-old animals might have a protective role. We conclude that GCs chronic excess affects APCs’ adipogenic capacity, modifying their competency. This change would modulate the hyperplastic/hypertrophic balance determining healthy or unhealthy RPAT expansion and, therefore, its functionality. - Artículo
Acceso Abierto Oral Metformin Treatment Counteracts Adipoinsular Axis Dysfunction in Hypothalamic Obese Rats(2015) Castrogiovanni, Daniel; Ongaro, Luisina; Zuburía, Guillermina; Giovambattista, Andrés; Spinedi, EduardoRats neonatally treated withmonosodiumL-glutamate (MSG) are deeply dysfunctional in adulthood. We explored the effect of an oral low dose of metformin treatment in male MSG rats on adipoinsular axis and visceral adipose tissue (VAT) dysfunctions, in both basal (nonfasting) and endotoxemia conditions. MSG rats, treated or not treated with metformin (30 days prior to experimentation), and control litter-mates (CTR) were studied at 90 days of age. Peripheral concentrations of glucose, lipids, and hormones were determined in basal and post-lipopolysaccharide (LPS) treatment conditions. Food intake and body weight (BW) were recorded and VAT mass and leptin mRNA levels were evaluated. Data indicated that MSG rats were lighter and displayed hypercorticosteronemia, hypophagia, adipoinsular axis hyperactivity, and enhanced VAT mass associated with an increased leptin gene expression. Interestingly,metformin-treatedMSG rats corrected BWcatch-up and counteracted VAT (mass and leptinmRNA level) and adipoinsular axis (basal and post-LPS) dysfunctions. Thus metformin treatment in MSG rats is able to correct several VAT and metabolic-endocrine dysfunctions. Our study suggests that a low-dose metformin therapy is effective to correct, at least in part, adipoinsular axis dysfunction in hypertrophic obese phenotypes, such as that of the human Cushing syndrome. - Artículo
Acceso Abierto Long-Term Fructose Intake Increases Adipogenic Potential: Evidence of Direct Effects of Fructose on Adipocyte Precursor Cells(2016) Zubiría, Guillermina; Alzamendi, Ana; Moreno, Griselda; Rey, María Amanda; Spinedi, Eduardo; Giovambattista, AndrésWe have previously addressed that fructose rich diet (FRD) intake for three weeks increases the adipogenic potential of stromal vascular fraction cells from the retroperitoneal adipose tissue (RPAT). We have now evaluated the effect of prolonged FRD intake (eight weeks) on metabolic parameters, number of adipocyte precursor cells (APCs) and in vitro adipogenic potential from control (CTR) and FRD adult male rats. Additionally, we have examined the direct fructose effects on the adipogenic capacity of normal APCs. FRD fed rats had increased plasma levels of insulin, triglyceride and leptin, and RPAT mass and adipocyte size. FACS studies showed higher APCs number and adipogenic potential in FRD RPAT pads; data is supported by high mRNA levels of competency markers: PPARγ2 and Zfp423. Complementary in vitro experiments indicate that fructose-exposed normal APCs displayed an overall increased adipogenic capacity. We conclude that the RPAT mass expansion observed in eight week-FRD fed rats depends on combined accelerated adipogenesis and adipocyte hypertrophy, partially due to a direct effect of fructose on APCs. - Artículo
Acceso Abierto High Risk of Metabolic and Adipose Tissue Dysfunctions in Adult Male Progeny, Due to Prenatal and Adulthood Malnutrition Induced by Fructose Rich Diet(2016) Alzamendi, Ana; Zubiría, Guillermina; Moreno, Gricelda; Portales, Andrea Estefanía; Spinedi, Eduardo; Giovambattista, AndrésThe aim of this work was to determine the effect of a fructose rich diet (FRD) consumed by the pregnant mother on the endocrine-metabolic and in vivo and in vitro adipose tissue (AT) functions of the male offspring in adulthood. At 60 days of age, rats born to FRD-fed mothers (F) showed impaired glucose tolerance after glucose overload and high circulating levels of leptin (LEP). Despite the diminished mass of retroperitoneal AT, this tissue was characterized by enhanced LEP gene expression, and hypertrophic adipocytes secreting in vitro larger amounts of LEP. Analyses of stromal vascular fraction composition by flow cytometry revealed a reduced number of adipocyte precursor cells. Additionally, 60 day-old control (C) and F male rats were subjected to control diet (CC and FC animals) or FRD (CF and FF rats) for three weeks. FF animals were heavier and consumed more calories. Their metabolic-endocrine parameters were aggravated; they developed severe hyperglycemia, hypertriglyceridemia, hyperleptinemia and augmented AT mass with hypertrophic adipocytes. Our study highlights that manipulation of maternal diet induced an offspring phenotype mainly imprinted with a severely unhealthy adipogenic process with undesirable endocrine-metabolic consequences, putting them at high risk for developing a diabetic state.
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