Expressão do mRNA do gene Capn 2 e índice de apoptose de ilhotas pancreáticas de rato tratadas com fibrilas de amilina e com oligômeros de amilina de tamanho intermediário

O depósito de amilina é um achado histopatológico freqüente em pacientes portadores de diabetes melito tipo 2 (DM 2) e parece estar relacionado à disfunção da célula beta pancreática característica desta doença. Apenas as moléculas de amilina que sofrem agregação in vivo, tal como a amilina humana, são citotóxicas para as células beta, enquanto as variedades não agregantes, como a amilina de rato, não apresentam efeito deletério. Com o objetivo de compreender melhor os mecanismos de toxicidade associados à forma agregante da amilina, um projeto em andamento em nosso laboratório estudou, por micro-arranjos de cDNA, o perfil de genes modulados pela amilina humana em ilhotas pancreáticas murídeas, comparando duas situações específicas: ilhotas tratadas com fibrilas de amilina (“amilina madura”) e ilhotas tratadas com oligômeros de tamanho intermediário (“amilina fresca”), já que evidências recentes apontam para um efeito deletério apenas de oligômeros de amilina. As ilhotas foram isoladas a partir de ratos Wistar, mantidas em cultura por 24 horas e a seguir tratadas com 10

Análise de interação genética entre mutantes de eIF5A e de fatores de degradação de mRNA e busca de supressores extragênicos em S. cerevisae

O provável fator de início de tradução 5A (eIF5A) é altamente conservado de arqueas a mamíferos e sofre uma modificação pós-traducional única e essencial chamada hipusinação. Este fator já foi relacionado ao transporte nucleocitoplasmático, à degradação de mRNA e à proliferação celular. Dados recentes restabelecem uma função para eIF5A na tradução e sugerem a sua atuação na etapa de elongação ao invés de início, como originalmente proposto. Uma vez que o envolvimento de eIF5A com a degradação de mRNA ainda não foi elucidado, tornou-se interessante estudar qual a natureza desta relação. O metabolismo de mRNA é um processo complexo que envolve as etapas da tradução, repressão da tradução e degradação de mRNA. Na primeira parte deste trabalho, foi avaliada a existência de interação genética sintética entre os mutantes tif51A-1 e tif51A-3 e mutantes de fatores envolvidos com a repressão da tradução e/ou degradação de mRNA. Foi revelada uma supressão parcial do fenótipo de termossensibilidade com nocautes dos genes SBP1, DHH1 e PAT1, que codificam fatores ativadores da remoção do capacete de metilguanosina e repressores da tradução. Por outro lado, uma interação sintético doente (“synthetic sick”) entre os mutantes tif51A-1 e xrn1Δ foi observada.Os dados obtidos reforçam o envolvimento de eIF5A com a elongação da tradução, mostram que o efeito de eIF5A na degradação de mRNA é secundário e sugerem uma função para eIF5A como ativador da tradução. Na segunda etapa são apresentados os resultados do rastreamento de supressores extragênicos do mutante tif51A-1 através de deleções genômicas induzidas por transposon. Foram rastreados aproximadamente 2,2x105 transformantes... (Resumo completo, clicar acesso eletrônico abaixo)

Loss of nuclear poly(A)-binding protein 1 (PABPN1) causes defects in myogenesis and mRNA biogenesis

The nuclear poly(A)-binding protein 1 (PABPN1) is a ubiquitously expressed protein that plays a critical role in polyadenylation. Short expansions of the polyalanine tract in the N-terminus of PABPN1 lead to oculopharyngeal muscular dystrophy (OPMD), which is an adult onset disease characterized by eyelid drooping, difficulty in swallowing and weakness in the proximal limb muscles. Although significant data from in vitro biochemical assays define the function of PABPN1 in control of poly(A) tail length, little is known about the role of PABPN1 in mammalian cells. To assess the function of PABPN1 in mammalian cells and specifically in cells affected in OPMD, we examined the effects of PABPN1 depletion using siRNA in primary mouse myoblasts from extraocular, pharyngeal and limb muscles. PABPN1 knockdown significantly decreased cell proliferation and myoblast differentiation during myogenesis in vitro. At the molecular level, PABPN1 depletion in myoblasts led to a shortening of mRNA poly(A) tails, demonstrating the cellular function of PABPN1 in polyadenylation control in a mammalian cell. In addition, PABPN1 depletion caused nuclear accumulation of poly(A) RNA, revealing that PABPN1 is required for proper poly(A) RNA export from the nucleus. Together, these experiments demonstrate that PABPN1 plays an essential role in myoblast proliferation and differentiation, suggesting that it is required for muscle regeneration and maintenance in vivo.

Relationship between levels of neuropeptide Substance P in periodontal disease and chronic pain: a literature review

The aim of the current review was to investigate the relationship between levels of neuropeptide Substance P in periodontal disease and chronic pain. Substance P is a neuropeptide that is directly related with pain. In periodontal disease, it is expressed during the inflammatory process, and is one of the factors responsible for bone resorption. Studies have shown that Substance P levels are highest in the gingival crevicular fluid from sites with active periodontal disease and bone loss. The persistence of these substances could be sufficient to stimulate neurogenic inflammation in susceptible tissues, and cause pain. The scientific literature shows that Substance P expressed during periodontal disease can be a risk factor for patients with systemic inflammatory pathologies, such as chronic arthritis or rheumatoid arthritis. Additional research is needed to confirm the participation of this substance in the origin of some types of chronic pain.

Ovarian superstimulation using FSH combined with equine chorionic gonadotropin (eCG) upregulates mRNA encoding proteins involved with LH receptor intracellular signaling in granulosa cells from Nelore cows

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Expressão diferencial de mRNA em células de cultivo infectadas ple herpesvírus bovino 5

Pós-graduação em Medicina Veterinária - FMVZ

Lycopene-rich tomato oleoresin modulates plasma adiponectin concentration and mRNA levels of adiponectin, SIRT1, and FoxO1 in adipose tissue of obese rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of Cardiorespiratory Fitness on PPARG mRNA Expression Using Monozygotic Twin Case Control

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

TLR2 and TLR4 polymorphisms influence mRNA and protein expression in colorectal cancer

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Elevated serum folic acid concentrations were associated with higher mRNA expression of DHFR gene in patients with hereditary spherocytosis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of functional polymorphisms in TNF-α, IL-8, and IL-10 cytokine genes on mRNA expression levels and risk of gastric cancer

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Prostaglandin receptors (EP2 and EP4) and angiotensin receptor (AGTR2) mRNA expression increases in the oviducts of Nelore cows submitted to ovarian superstimulation

Many peptides are responsible for the coordination of muscle contraction, secretion and ciliary beating of the oviduct epithelium to allow the transport of gametes and embryos, including vascular endothelial growth factors (VEGF), prostaglandins (PGs), endotelin-1 (ET-1) andangiotensinII(Ang II). The effect of reproductive biotechnologiesusedto improve embryo yield on oviduct gene expression is poorly understood. Thus, the aim of the present study was to evaluate the effect of ovarian superstimulation on the mRNA expression of the genes encoding the major peptides involved in oviduct contraction in bovine. Therefore, Nelore cows were submitted to P-36 (n = 5) or P-36/eCG (n = 5) ovarian superstimulatory protocols and a control group of cows was not submitted to any superstimulatory protocol (n = 5). The relative expression of VEGF (VEGF, Flk1, Flt1), Ang II (AGTR2, ACE1), ET1 (ET1, ECE1) and PG pathway members (PGES, EP2, EP4, COX1, COX2) was analyzed using real time RT-PCR in each of oviduct segment (infundibulum, ampulla and isthmus). All target genes were expressed in the three segments of the bovine oviduct; however, specific genes were regulated by ovarian superstimulation: EP2 and EP4 receptors mRNA was affected by P- 36/eCG protocol, in the ampulla and infundibulum, respectively; and AGTR2 mRNA was up-regulated by both the P-36/eCG and P-36 protocols in the isthmus. The upregulation of EP2, EP4 and AGTR2 expression in the superstimulated cows suggests a suitable effect of FSH and eCG on bovine oviduct physiology, coordinating the contraction in Nelore cows

Glucocorticoids are required for meal-induced changes in the expression of hypothalamic neuropeptides

Glucocorticoid deficiency is associated with a decrease of food intake. Orexigenic peptides, neuropeptide Y (NPY) and agouti related protein (AgRP), and the anorexigenic peptide proopiomelanocortin (POMC), expressed in the arcuate nucleus of the hypothalamus (ARC), are regulated by meal-induced signals. Orexigenic neuropeptides, melanin-concentrating hormone (MCH) and orexin, expressed in the lateral hypothalamic area (LHA), also control food intake. Thus, the present study was designed to test the hypothesis that glucocorticoids are required for changes in the expression of hypothalamic neuropeptides induced by feeding. Male Wistar rats (230-280 g) were subjected to ADX or sham surgery. ADX animals received 0.9% NaCl in the drinking water, and half of them received corticosterone in the drinking water (B: 25 mg/L, ADX + B). Six days after surgery, animals were fasted for 16 h and they were decapitated before or 2 h after refeeding for brain tissue and blood collections. Adrenalectomy decreased NPY/AgRP and POMC expression in the ARC in fasted and refed animals, respectively. Refeeding decreased NPY/AgRP and increased POMC mRNA expression in the ARC of sham and ADX + B groups, with no effects in ADX animals. The expression of MCH and orexin mRNA expression in the LHA was increased in ADX and ADX + B groups in fasted condition, however there was no effect of refeeding on the expression of MCH and orexin in the LHA in the three experimental groups. Refeeding increased plasma leptin and insulin levels in sham and ADX + B animals, with no changes in leptin concentrations in ADX group, and insulin response to feeding was lower in this group. Taken together, these data demonstrated that circulating glucocorticoids are required for meal-induced changes in NPY, AgRP and POMC mRNA expression in the ARC. The lower leptin and insulin responses to feeding may contribute to the altered hypothalamic neuropeptide expression after adrenalectomy. (C) 2012 Elsevier Ltd. All rights reserved.

Altered Neurotrophin, Neuropeptide, Cytokines and Nitric Oxide Levels in Autism

Introduction: Modifications in neurotrophins, neuropeptides, cytokines and nitric oxide (NO) levels in autism may represent different biological aspects of the disease. In the present study we investigate simultaneously all these variables as an attempt to clarify their interrelationships in autism. Methods: Plasma levels of vasoactive intestinal peptide (VIP), neurotrophin-3 (NT-3), cytokines and nitric oxide (NO) were determined in children with DSM-IV autistic disorder (n = 24) and in age- and gender-matched healthy controls (n = 24). VIP, NT-3, IFN-gamma and IL-1 beta levels were measured by ELISA, TNF-alpha, IL-10, IL-6, IL-4, IL-2 were evaluated by flow cytometry, and NO by Griess reaction. Results: Plasma levels of VIP, IFN-gamma and NO were significantly higher and NT-3 plasma levels were significantly lower in children with autism, compared to the healthy subjects. In children with autism there was a positive correlation between plasma levels of NO and IFN-gamma. Discussion: Our results indicate the presence of altered levels of neurotrophin and neuropeptide in infantile autism and provide additional evidence that higher levels of IFN-gamma may be associated with increased oxidative stress in autism.

Phenotypic alterations of neuropeptide Y and calcitonin gene-related peptide-containing neurons innervating the rat temporomandibular joint during carrageenan-induced arthritis

The aim of this study was to identify immunoreactive neuropeptide Y (NPY) and calcitonin gene-related peptide (CGRP) neurons in the autonomic and sensory ganglia, specifically neurons that innervate the rat temporomandibular joint (TMJ). A possible variation between the percentages of these neurons in acute and chronic phases of carrageenan-induced arthritis was examined. Retrograde neuronal tracing was combined with indirect immunofluorescence to identify NPY-immuno-reactive (NPY-IR) and CGRP-immunoreactive (CGRP-IR) neurons that send nerve fibers to the normal and arthritic temporomandibular joint. In normal joints, NPY-IR neurons constitute 78 +/- 3%, 77 +/- 6% and 10 +/- 4% of double-labeled nucleated neuronal profile originated from the superior cervical, stellate and otic ganglia, respectively. These percentages in the sympathetic ganglia were significantly decreased in acute (58 +/- 2% for superior cervical ganglion and 58 +/- 8% for stellate ganglion) and chronic (60 +/- 2% for superior cervical ganglion and 59 +/- 15% for stellate ganglion) phases of arthritis, while in the otic ganglion these percentages were significantly increased to 19 +/- 5% and 13 +/- 3%, respectively. In the trigeminal ganglion, CGRP-IR neurons innervating the joint significantly increased from 31 +/- 3% in normal animals to 54 +/- 2% and 49 +/- 3% in the acute and chronic phases of arthritis, respectively. It can be concluded that NPY neurons that send nerve fibers to the rat temporomandibular joint are located mainly in the superior cervical, stellate and otic ganglia. Acute and chronic phases of carrageenan-induced arthritis lead to an increase in the percentage of NPY-IR parasympathetic and CGRP-IR sensory neurons and to a decrease in the percentage of NPY-IR sympathetic neurons related to TMJ innervation.