Isadora Clivatti Furigo - Academia.edu (original) (raw)

Papers by Isadora Clivatti Furigo

Nature Communications, 2019

The original version of this Article contained an error in the spelling of the author J. Donato J... more The original version of this Article contained an error in the spelling of the author J. Donato Jr, which was incorrectly given as Donato J. Jr. This has now been corrected in both the PDF and HTML versions of the Article.

In utero exposure to maternal obesity programs a susceptibility to develop obesity. Animal models... more In utero exposure to maternal obesity programs a susceptibility to develop obesity. Animal models have shown that offspring obesity is often preceded by increased food intake, however, the mechanisms that mediate these changes are not understood. Using a mouse model of maternal diet-induced obesity we observed increased intake specifically of a high-fat pellet in adult offspring of obese mothers. Through small RNA sequencing, we identified programmed overexpression of miR-505-5p in the hypothalamus of offspring of obese mothers that is established in the fetus, and confirmed in vitro that fatty acid exposure increases expression of miR-505-5p. Pulsed SILAC analysis demonstrated protein targets of miR-505-5p are enriched in pathways involved in fatty acid metabolism. These include key components of neuronal fatty acid sensing, such as Cpt1a, that are implicated in BMI regulation in human genetic studies. Over-expression of miR-505-5p decreased neuronal fatty acid uptake and metabolis...

O comportamento agressivo maternal é desenvolvido por ratas lactantes com o intuito de preservar ... more O comportamento agressivo maternal é desenvolvido por ratas lactantes com o intuito de preservar a vida de sua prole. Nesse estudo demonstramos que a Área Hipotalâmica de Ataque (HAA), particularmente a porção ventrolateral do núcleo ventromedial (VMHvl) e a parte tuberal do hipotálamo lateral (LHAtu), apresentam um papel crítico para a expressão do comportamento, ao correlacionarmos os níveis de agressão maternal com a ativação de tais setores, e detectarmos prejuízo no comportamento em um grupo submetido a lesões citotóxicas bilaterais por NMDA circunscritas a 1/3 caudal da HAA, e em outro grupo lesões que se estenderam por 2/3 caudais do eixo rostro caudal da HAA. Os parâmetros não agressivos não apresentaram diferenças entre os grupos, assim como os comportamentos maternais, indicando que as lesões não afetaram o cuidado das fêmeas com a sua prole. Em uma análise da densidade de células Fos positivas de possíveis alvos dessas estruturas hipotalâmicas estudadas, não detectamos di...

Furigo IC. The study of the mechanisms of action of bromocriptine and prolactin antagonists to tr... more Furigo IC. The study of the mechanisms of action of bromocriptine and prolactin antagonists to treat Type 2 Diabetes Mellitus and Obesity. [Ph. D. thesis (Human Physiology)].

Endocrinology, Jan 20, 2018

Previous studies have shown that bromocriptine mesylate (Bromo) lowers blood glucose levels in ad... more Previous studies have shown that bromocriptine mesylate (Bromo) lowers blood glucose levels in adults with type 2 diabetes mellitus. However, the mechanism of action of the anti-diabetic effects of Bromo is unclear. As a dopamine receptor agonist, Bromo can alter brain dopamine activity affecting glucose control. However, Bromo also suppresses prolactin (Prl) secretion, and Prl levels modulate glucose homeostasis. Thus, the objective of the present study was to investigate whether Bromo improves insulin sensitivity via inhibition of Prl secretion. Male and female ob/ob animals (a mouse model of obesity and insulin resistance) were treated with Bromo and/or Prl. Bromo-treated ob/ob mice exhibited lower serum Prl concentration, improved glucose and insulin tolerance, as well as increased insulin sensitivity in the liver and skeletal muscle, compared to vehicle-treated mice. Prl replacement in Bromo-treated mice normalized serum Prl concentration without inducing hyperprolactinemia. Im...

Physiological Reports, 2018

Several metabolic adaptations emerge during pregnancy and continue through lactation, including i... more Several metabolic adaptations emerge during pregnancy and continue through lactation, including increases in food intake and body weight, as well as insulin and leptin resistance. These maternal adaptations are thought to play a role in offspring viability and success. Using a model of attenuated maternal metabolic adaptations induced by ablation of the Socs3 gene in leptin receptor expressing cells (SOCS3 KO mice), our study aimed to investigate whether maternal metabolic changes are required for normal offspring development, and if their absence causes metabolic imbalances in adulthood. The litters were subjected to a cross-fostering experimental design to distinguish the prenatal and postnatal effects caused by maternal metabolic adaptations. Males either born or raised by SOCS3 KO mice showed reduced body weight until 8 weeks of life. Both adult males and females born or raised by SOCS3 KO mice also had lower body adiposity. Despite that, no significant changes in energy expenditure, glucose tolerance or insulin resistance were observed. However, males either born or raised by SOCS3 KO mice showed reduced brain mass in adulthood. Furthermore, animals born from SOCS3 KO mice also had lower proopiomelanocortin fiber density in the paraventricular nucleus of the hypothalamus. In conclusion, these findings indicate that the commonly observed metabolic changes in pregnancy and lactation are necessary for normal offspring growth and brain development.

Neuroscience, 2017

Previous studies have shown that leptin resistance is a key feature that leads to gestational met... more Previous studies have shown that leptin resistance is a key feature that leads to gestational metabolic adaptions. We hypothesized that leptin sensitivity in the ventromedial nucleus of the hypothalamus (VMH) plays a critical role regulating gestational metabolic changes. In the present study, we generated a mouse model carrying ablation of the suppressor of cytokine signaling 3 (SOCS3) in steroidogenic factor-1 (SF1) cells, which include the VMH, in order to investigate whether increased leptin sensitivity in this neuronal population prevents at least part of the metabolic changes typically observed during gestation and lactation. As predicted by the inhibitory effects of SOCS3 in leptin signaling, pregnant SF1 SOCS3 KO mice exhibited increased leptin sensitivity in the VMH, since an acute leptin injection induced a 95% increase in the STAT3 phosphorylation in this nucleus, compared to control animals (p = 0.02). Despite that, SF1 SOCS3 KO mice showed similar weight gain, food intake, hypothalamic neuropeptide expression and serum leptin levels during pregnancy compared to control littermates. Unexpectedly, SF1 SOCS3 KO mice exhibited glucose intolerance during pregnancy. SF1 SOCS3 KO mice also presented a lower body weight (-3%; p < 0.05) during mid and late lactation, although food intake, litter size and offspring growth were not affected. Our findings suggest that increased leptin sensitivity in the VMH causes modest metabolic effects and is not sufficient to prevent major metabolic adaptations of pregnancy and lactation.

Brain structure & function, Jan 19, 2018

The signal transducer and activator of transcription 5 (STAT5) is a transcription factor recruite... more The signal transducer and activator of transcription 5 (STAT5) is a transcription factor recruited by numerous cytokines. STAT5 is important for several physiological functions, including body and tissue growth, mammary gland development, immune system and lipid metabolism. However, the role of STAT5 signaling for brain functions is still poorly investigated, especially regarding cognitive aspects. Therefore, the objective of the present study was to investigate whether brain STAT5 signaling modulates learning and memory formation. For this purpose, brain-specific STAT5 knockout (STAT5 KO) mice were studied in well-established memory tests. Initially, we confirmed a robust reduction in STAT5a and STAT5b mRNA levels in different brain structures of STAT5 KO mice. STAT5 KO mice showed no significant alterations in metabolism, growth, somatotropic axis and spontaneous locomotor activity. In contrast, brain-specific STAT5 ablation impaired learning and memory formation in the novel obje...

Journal of Endocrinology, 2017

Many hormones/cytokines are secreted in response to exercise and cytokine signaling may play a pi... more Many hormones/cytokines are secreted in response to exercise and cytokine signaling may play a pivotal role in the training adaptations. To investigate the importance of cytokine signaling during vertical ladder climbing, a resistance exercise model, we produced mice lacking SOCS3 protein exclusively in steroidogenic factor-1 (SF1) cells (SF1 Socs3 KO mice). SF1 expression is found in steroidogenic cells of the adrenal cortex and gonads, as well as in neurons of the ventromedial nucleus of the hypothalamus. Histological markers of the fetal adrenal zone (or X-zone in rodents) were still present in adult males and postpartum SF1 Socs3 KO females, suggesting a previously unrecognized effect of SOCS3 on the terminal differentiation of the adrenal gland. This change led to a distinct distribution of lipid droplets along the adrenal cortex. Under basal conditions, adult SF1 Socs3 KO mice exhibited similar adrenal weight, and plasma ACTH and corticosterone concentrations. Nonetheless, SF1...

Molecular and cellular endocrinology, Jun 15, 2017

Previous studies have shown that kisspeptin neurons are important mediators of prolactin's ef... more Previous studies have shown that kisspeptin neurons are important mediators of prolactin's effects on reproduction. However, the cellular mechanisms recruited by prolactin to affect kisspeptin neurons remain unknown. Using whole-cell patch-clamp recordings of brain slices from kisspeptin reporter mice, we observed that 20% of kisspeptin neurons in the anteroventral periventricular nucleus was indirectly depolarized by prolactin via an unknown population of prolactin responsive neurons. This effect required the phosphatidylinositol 3-kinase signaling pathway. No effects on the activity of arcuate kisspeptin neurons were observed, despite a high percentage (70%) of arcuate neurons expressing prolactin-induced STAT5 phosphorylation. To determine whether STAT5 expression in kisspeptin cells regulates reproduction, mice carrying Stat5a/b inactivation specifically in kisspeptin cells were generated. These mutants exhibited an early onset of estrous cyclicity, indicating that STAT5 tra...

The Journal of comparative neurology, Jan 24, 2017

The habenula is an epithalamic structure differentiated into two nuclear complexes, medial (MHb) ... more The habenula is an epithalamic structure differentiated into two nuclear complexes, medial (MHb) and lateral habenula (LHb). Recently, MHb together with its primary target, the interpeduncular nucleus (IP), have been identified as major players in mediating the aversive effects of nicotine. However, structures downstream of the MHb-IP axis, including the median (MnR) and caudal dorsal raphe nucleus (DRC), may contribute to the behavioral effects of nicotine. The afferent and efferent connections of the IP have hitherto not been systematically investigated with sensitive tracers. Thus, we placed injections of retrograde or anterograde tracers into different IP subdivisions or the MnR and additionally examined the transmitter phenotype of major IP and MnR afferents by combining retrograde tract tracing with immunofluorescence and in situ hybridization techniques. Besides receiving inputs from MHb and also LHb, we found that IP is reciprocally interconnected mainly with midline structu...

Protein expression and purification, Mar 22, 2016

The human growth hormone receptor antagonist G120R-hGH precludes dimerization of GH and prolactin... more The human growth hormone receptor antagonist G120R-hGH precludes dimerization of GH and prolactin receptors and consequently JAK/STAT signaling. Some modifications in this antagonist resulted in a drug specific for the GH receptor, called Pegvisomant (Somavert(®)). However, the original G120R-hGH is usually synthesized in bacterial cytoplasm as inclusion bodies, not being a commercial product. The present work describes the synthesis and characterization of G120R-hGH secreted into bacterial periplasm and obtained with a vector based on a constitutive lambda-PL promoter. This antagonist can be useful for studies aiming at investigating the effects of a simultaneous inhibition of GH and prolactin signaling, as a potential anti-tumoral or anti-diabetic compound. G120R-hGH, synthesized using the W3110 E. coli strain, showed a yield of 1.34 ± 0.24 μg/ml/A600 (∼0.79 mg G120R-hGH/g of wet weight cells) after cultivation at 30 °C up to 3 A600 units and induction at 37 °C, for 6 h, with fina...

Endocrinology, 2016

Weight regain frequently follows interventions that reduce body weight, leading to a failure in l... more Weight regain frequently follows interventions that reduce body weight, leading to a failure in long-term obesity treatment. Inhibitory proteins of the leptin signaling pathway, such as the suppressor of cytokine signaling 3 (SOCS3), have been studied in conditions that predispose animals to obesity. However, whether SOCS3 modulates postrestriction hyperphagia and weight regain remains unknown. Mice lacking SOCS3 protein specifically in leptin receptor (LepR)-expressing cells (LepR SOCS3 knockout [KO]) were generated and studied in fasting and refeeding conditions. LepR SOCS3 KO mice exhibited increased leptin sensitivity in the hypothalamus. Notably, LepR SOCS3 KO males and females showed attenuated food intake and weight regain after 48 hours of fasting. Postrestriction hyperleptinemia was also prevented in LepR SOCS3 KO mice. Next, we studied possible mechanisms and neural circuits involved in the SOCS3 effects. SOCS3 deletion did not prevent fasting-or refeeding-induced c-Fos expression in the arcuate nucleus of the hypothalamus (ARH) nor fasting-induced increased excitability of ARH LepR-expressing cells. On the other hand, SOCS3 ablation reduced the mRNA levels of hypothalamic orexigenic neuropeptides during fasting (neuropeptide Y, agouti-related protein, orexin, and melanin-concentrating hormone). In summary, our findings suggest that increased leptin sensitivity contributes to the maintenance of a reduced body weight after food deprivation. In addition, the attenuated postrestriction food intake observed in mutant mice was not explained by fasting-induced changes in the activity of ARH neurons but exclusively by a lower transcription of orexigenic neuropeptides during fasting. These results indicate a partial dissociation between the regulation of neuronal activity and gene expression in ARH LepR-expressing cells. (Endocrinology 157: 3901-3914, 2016) T he incidence of obesity has reached epidemic proportions in the United States and worldwide (1, 2). Obesity increases the risk of cardiovascular diseases, diabetes, dyslipidemia, some types of cancer, among other comorbidities (3, 4). Consequently, obese individuals exhibit increased mortality rates and reduced quality of life (5-7). Additionally, obesity-associated diseases impose enormous health care costs on society, which have negative impacts in terms of public health (7, 8). Therefore, it is imperative to find new approaches for obesity treatment. Life style changes, including a balanced diet and regular physical activity, are the primary recommendation for preventing and treating obesity. Pharmacological and surgical approaches are also available, but these interventions,

Brain research, Sep 16, 2016

Neurons that express the prohormone proopiomelanocortin (POMC) in the arcuate hypothalamic nucleu... more Neurons that express the prohormone proopiomelanocortin (POMC) in the arcuate hypothalamic nucleus (Arc) are engaged in the regulation of energy balance and glucose homeostasis. Additionally, POMC neurons are considered key first-order cells regulated by leptin. Interestingly, in the Arc, POMC cells that express the leptin receptor (POMC/LepR+ cells) are found side by side with POMC cells not directly responsive to leptin (POMC/LepR- cells). However, it remains unknown whether these distinct populations innervate different target regions. Therefore, the objective of the present study was to compare the projections of POMC/LepR+ and POMC/LepR- neurons. Using genetically modified LepR-reporter mice to identify leptin receptor-expressing cells and immunohistochemistry to stain POMC-derived peptides (α-MSH or β-endorphin) we confirmed that approximately 80% of Arc β-endorphin-positive neurons co-expressed leptin receptors. POMC/LepR+ and POMC/LepR- axons were intermingled in all of thei...

Molecular and Cellular Endocrinology, 2016

Several growth factors and cytokines recruit the signal transducer and activator of transcription... more Several growth factors and cytokines recruit the signal transducer and activator of transcription 5 (STAT5) signaling pathway to control cell proliferation, differentiation and apoptosis. Nonetheless, the importance of this transcription factor for brain functions is still poorly understood. Because some STAT5-inducing hormones, such as prolactin and leptin, act in the brain to regulate the expression of motivated behaviors, this signaling pathway is likely involved in behavioral modulation. Therefore, the objective of the present review was to summarize and discuss the available data regarding the possible role of central STAT5 signaling in the regulation of brain functions, especially on behavioral control. We discussed studies that investigated the importance of STAT5 signaling in the regulation of maternal and feeding behaviors. Additionally, we highlighted other behaviors that could be potentially affected by STAT5 signaling. This knowledge may help to understand how motivated behaviors are regulated at the cellular level.

Brain structure & function, Jan 12, 2016

Growth hormone (GH) exerts important biological effects primarily related to growth and metabolis... more Growth hormone (GH) exerts important biological effects primarily related to growth and metabolism. However, the role of GH signaling in the brain is still elusive. To better understand GH functions in the brain, we mapped the distribution of GH-responsive cells and identified the receptors involved in GH central effects. For this purpose, mice received an acute intraperitoneal challenge with specific ligands of the GH receptor (mouse GH), prolactin receptor (prolactin) or both receptors (human GH), and their brains were subsequently processed immunohistochemically to detect the phosphorylated form of STAT5 (pSTAT5). GH induced pSTAT5 immunoreactivity in neurons, but not in astroglial cells of numerous brain regions, including the cerebral cortex, nucleus accumbens, hippocampus, septum and amygdala. The most prominent populations of GH-responsive neurons were located in hypothalamic areas, including several preoptic divisions, and the supraoptic, paraventricular, suprachiasmatic, pe...

FURIGO, I. C. Role of the ventromedial hypothalamus and tuberalis part of the lateral hypothalamu... more FURIGO, I. C. Role of the ventromedial hypothalamus and tuberalis part of the lateral hypothalamus in maternal behavior aggression. 2012. 57 p. Masters thesis (

Alpha-ketoisocaproate (KIC) and Beta hydroxy- beta methylbutyrate (HMB) are metabolites of the am... more Alpha-ketoisocaproate (KIC) and Beta hydroxy- beta methylbutyrate (HMB) are metabolites of the amino acid leucine. The first step in HMB metabolism is the reversible transamination of leucine to KIC, which occurs mainly extrahepatically. Following this enzymatic reaction, KIC is converted to HMB by two routes: through the cytosolic enzyme KIC dioxygenase; or through formation of isovaleryl-CoA by branched-chain ketoacid dehydrogenase (BCKD) in liver, which after some steps results in HMB formation. Under normal conditions the majority of KIC is converted into isovaleryl-CoA, with approximately 5% of leucine consumed metabolized into HMB. HMB and KIC have been proposed to enhance physical performance and muscle hypertrophy via their effects on muscle proteolysis and protein synthesis. Studies investigating the mechanisms by which HMB promotes increases in strength and muscle hypertrophy are still in preliminary stages. Based on the results of these studies, it is postulated that enha...