RESUMO
Neuropeptides derived from larger precursor proteins are secreted as signalling molecules by neurons and regulate diverse physiological and behavioural processes in animals. Recently, we reported the discovery of ArCRZ (HNTFTMGGQNRWKAG-NH2) and ArLQ (EEKTRFPKFMRW-NH2)-novel neuropeptides in the starfish Asterias rubens that are orthologs of arthropod corazonins and molluscan luqins, respectively. However, our efforts to generate antibodies to ArCRZ and ArLQ have been unsuccessful, precluding immunohistochemical analysis of their expression. Here, we investigated an alternative experimental approach for neuropeptide immunohistochemistry by generating antibodies to peptides corresponding to the C-terminal region of the precursor proteins. As proof of principle, we generated antibodies to the C-terminal region of the precursor of the vasopressin/oxytocin-type neuropeptide asterotocin and show that these reveal immunostaining in A. rubens that is very similar to that observed with asterotocin antibodies. Furthermore, antibodies to the C-terminal region of the ArCRZ precursor (ArCRZP) and the ArLQ precursor (ArLQP) produced patterns of immunostaining consistent, respectively, with the distribution of ArCRZP and ArLQP transcripts revealed by mRNA in situ hybridisation. Detailed immunohistochemical analysis revealed widespread expression of ArCRZP and ArLQP in A. rubens, including the central nervous system, digestive system and the body wall and its associated appendages (e.g. tube feet), providing a neuroanatomical framework for investigation and interpretation of the pharmacological actions of ArCRZ and ArLQ in A. rubens. Furthermore, our findings provide a basis for use of antibodies to the C-terminal region of neuropeptide precursor proteins in other species where the production of antibodies to the bioactive neuropeptides is unsuccessful.
Assuntos
Asterias , Neuropeptídeos , Animais , Estrelas-do-Mar , Ocitocina/metabolismo , Sequência de Aminoácidos , Neuropeptídeos/metabolismo , Vasopressinas/metabolismoRESUMO
Somatostatin (SS) and allatostatin-C (ASTC) are inhibitory neuropeptides in chordates and protostomes, respectively, which hitherto were identified as orthologs. However, echinoderms have two SS/ASTC-type neuropeptides (SS1 and SS2), and here, our analysis of sequence data indicates that SS1 is an ortholog of ASTC and SS2 is an ortholog of SS. The occurrence of both SS-type and ASTC-type neuropeptides in echinoderms provides a unique context to compare their physiological roles. Investigation of the expression and actions of the ASTC-type neuropeptide ArSS1 in the starfish Asterias rubens revealed that it causes muscle contraction (myoexcitation), contrasting with myoinhibitory effects of the SS-type neuropeptide ArSS2. Our findings suggest that SS-type and ASTC-type neuropeptides are paralogous and originated by gene duplication in a common ancestor of the Bilateria, with only one type being retained in chordates (SS) and protostomes (ASTC) but with both types being retained in echinoderms. Loss of ASTC-type and SS-type neuropeptides in chordates and protostomes, respectively, may have been due to their functional redundancy as inhibitory regulators of physiological processes. Conversely, the retention of both neuropeptide types in echinoderms may be a consequence of the evolution of a myoexcitatory role for ASTC-type neuropeptides mediated by as yet unknown signaling mechanisms.
Assuntos
Músculos/metabolismo , Neuropeptídeos/metabolismo , Estrelas-do-Mar/metabolismo , Sequência de Aminoácidos , Animais , Regulação da Expressão Gênica , Estrelas-do-Mar/genéticaRESUMO
Cosmetics procedures and products combined with environmental insults and daily routines induce irreversible changes in hair. As result of damage, the hair loses some of its properties like strength, elasticity, and smoothness. Recent studies revealed the positive effects of protein-based cosmetics in providing protection to hair. Additionally, these cosmetic products have also shown a great ability to modify hair fibers. We review the effect of protein-based cosmetic formulations on hair properties like color, scent, strength, shape, and volume, highlighting the potential of keratin-based particles and keratin-fusion proteins. In the future, incorporating multifunctional proteins and peptides in the development of alternative hair formulations will result in advanced, sustainable, ecofriendly cosmetic products with a great impact on the cosmetic industry.
Assuntos
Cosméticos , Preparações para Cabelo , Biotecnologia , Queratinas/química , Queratinas/metabolismo , PeptídeosRESUMO
Sulfakinin (SK)/cholecystokinin (CCK)-type neuropeptides regulate feeding and digestion in protostomes (e.g. insects) and chordates. Here, we characterised SK/CCK-type signalling for the first time in a non-chordate deuterostome - the starfish Asterias rubens (phylum Echinodermata). In this species, two neuropeptides (ArSK/CCK1, ArSK/CCK2) derived from the precursor protein ArSK/CCKP act as ligands for an SK/CCK-type receptor (ArSK/CCKR) and these peptides/proteins are expressed in the nervous system, digestive system, tube feet, and body wall. Furthermore, ArSK/CCK1 and ArSK/CCK2 cause dose-dependent contraction of cardiac stomach, tube foot, and apical muscle preparations in vitro, and injection of these neuropeptides in vivo triggers cardiac stomach retraction and inhibition of the onset of feeding in A. rubens. Thus, an evolutionarily ancient role of SK/CCK-type neuropeptides as inhibitory regulators of feeding-related processes in the Bilateria has been conserved in the unusual and unique context of the extra-oral feeding behaviour and pentaradial body plan of an echinoderm.
Assuntos
Colecistocinina/metabolismo , Colecistocinina/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Asterias/genética , Asterias/metabolismo , Proteínas Quinases Dependentes de Cálcio-Calmodulina , Linhagem Celular , Equinodermos , Sistema Nervoso/metabolismo , Neuropeptídeos/classificação , Neuropeptídeos/genética , Neuropeptídeos/metabolismo , Filogenia , Estrelas-do-MarRESUMO
Ohmic heating is a thermal processing method based on the application of electric fields directly into a semi-conductive medium. In this study, we explored for the first time the use of ohmic heating to obtain keratin films. The properties of the films prepared by ohmic heating and conventional heating were evaluated and compared under similar thermal profiles. A lower increase in free thiols' concentration was obtained for the keratin solutions and keratin films submitted to ohmic heating (16% increase for the keratin solution extracted from virgin hair, pH 9, submitted to ohmic heating and 23% when submitted to conventional heating). Significant differences in the swelling results were observed for the films prepared with keratin extracted from virgin hair, with a swelling decrease in about 55% for the films prepared by ohmic heating. Generally, the keratin films obtained by ohmic heating showed distinct properties comparatively to the films produced by conventional methods. The application of a fusion protein on the keratin films demonstrated their capacity to be used as substitutes to hair fibers when evaluating the potential of new cosmetic products. This work suggests that ohmic heating show potential to tailor keratin films properties depending on an intended application or functionality.
Assuntos
Condutividade Elétrica , Temperatura Alta , Queratinas/química , Membranas ArtificiaisRESUMO
Styling hair with straightening irons is a popular daily hair routine that significantly damage the hair keratin fiber due to the high temperature applied. In this study, we investigate the effect of two fusion proteins based on the human eye γD-crystallin conjugated with a keratin-based peptide (KP-Cryst Wt and KP-Cryst Mut) on hair exposed to thermal damage. The mutant form was designed to improve protein stability and promote interaction with the hair. Through the study, it was demonstrated the protection of Asian and Caucasian virgin hair's structure by the pretreatments with the KP-Cryst fusion proteins. After hair thermal exposure, a higher water content was quantified by TGA on the hair fibers pretreated with the fusion proteins (about 38% for the KP-Cryst Wt and 44% for the KP-Cryst Mut). Also, negligible alterations in hair fibers' stiffness were observed after iron application, demonstrating the proteins capacity to effectively prevent the conversion of keratin α-helix structure into ß-sheets. The results proved the capacity of the fusion proteins to bind to hair and protect it against high temperatures', supporting the development of new formulations based on the KP-Cryst proteins.
RESUMO
The present research relates to a fusion protein comprising a chromogenic blue ultramarine protein (UM) bound to a keratin-based peptide (KP). The KP-UM fusion protein explores UM chromogenic nature together with KP affinity towards hair. For the first time a fusion protein with a chromogenic nature is explored as a hair coloring agent. The KP-UM protein colored overbleached hair, being the color dependent on the formulation polarity. The protein was able to bind to the hair cuticle and even to penetrate throughout the hair fibre. Molecular dynamics studies demonstrated that the interaction between the KP-UM protein and the hair was mediated by the KP sequence. All the formulations recovered the mechanical properties of overbleached hair and KP-UM proved to be safe when tested in human keratinocytes. Although based on a chromogenic non-fluorescent protein, the KP-UM protein presented a photoswitch phenomenon, changing from chromogenic to fluorescent depending on the wavelength selected for excitation. KP-UM protein shows the potential to be incorporated in new eco-friendly cosmetic formulations for hair coloration, decreasing the use of traditional dyes and reducing its environmental impact.
Assuntos
Tinturas para Cabelo/metabolismo , Queratinas/metabolismo , Proteínas/metabolismo , Proteínas Recombinantes/metabolismo , Animais , Antozoários , Cor , Cabelo/metabolismo , Humanos , Peptídeos/metabolismoRESUMO
BACKGROUND: Vasopressin/oxytocin (VP/OT)-type neuropeptides are well known for their roles as regulators of diuresis, reproductive physiology and social behaviour. However, our knowledge of their functions is largely based on findings from studies on vertebrates and selected protostomian invertebrates. Little is known about the roles of VP/OT-type neuropeptides in deuterostomian invertebrates, which are more closely related to vertebrates than protostomes. RESULTS: Here, we have identified and functionally characterised a VP/OT-type signalling system comprising the neuropeptide asterotocin and its cognate G-protein coupled receptor in the starfish (sea star) Asterias rubens, a deuterostomian invertebrate belonging to the phylum Echinodermata. Analysis of the distribution of asterotocin and the asterotocin receptor in A. rubens using mRNA in situ hybridisation and immunohistochemistry revealed expression in the central nervous system (radial nerve cords and circumoral nerve ring), the digestive system (including the cardiac stomach) and the body wall and associated appendages. Informed by the anatomy of asterotocin signalling, in vitro pharmacological experiments revealed that asterotocin acts as a muscle relaxant in starfish, contrasting with the myotropic actions of VP/OT-type neuropeptides in vertebrates. Furthermore, in vivo injection of asterotocin had a striking effect on starfish behaviour-triggering fictive feeding where eversion of the cardiac stomach and changes in body posture resemble the unusual extra-oral feeding behaviour of starfish. CONCLUSIONS: We provide a comprehensive characterisation of VP/OT-type signalling in an echinoderm, including a detailed anatomical analysis of the expression of both the VP/OT-type neuropeptide asterotocin and its cognate receptor. Our discovery that asterotocin triggers fictive feeding in starfish provides important new evidence of an evolutionarily ancient role of VP/OT-type neuropeptides as regulators of feeding in animals.
Assuntos
Asterias/genética , Neuropeptídeos/genética , Sequência de Aminoácidos , Animais , Asterias/fisiologia , Comportamento Alimentar/fisiologia , Neuropeptídeos/química , Neuropeptídeos/metabolismo , Filogenia , Alinhamento de SequênciaRESUMO
Neuropeptides in deuterostomian invertebrates that have an Asn-Gly motif (NG peptides) have been identified as orthologs of vertebrate neuropeptide-S (NPS)-type peptides and protostomian crustacean cardioactive peptide (CCAP)-type neuropeptides. To obtain new insights into the physiological roles of NG peptides in deuterostomian invertebrates, here we have characterized the NG peptide signaling system in an echinoderm-the starfish Asterias rubens. The neuropeptide NGFFYamide was identified as the ligand for an A. rubens NPS/CCAP-type receptor, providing further confirmation that NG peptides are orthologs of NPS/CCAP-type neuropeptides. Using mRNA in situ hybridization, cells expressing the NGFFYamide precursor transcript were revealed in the radial nerve cords, circumoral nerve ring, coelomic epithelium, apical muscle, body wall, stomach, and tube feet of A. rubens, indicating that NGFFYamide may have a variety of physiological roles in starfish. One of the most remarkable aspects of starfish biology is their feeding behavior, where the stomach is everted out of the mouth over the soft tissue of prey. Previously, we reported that NGFFYamide triggers retraction of the everted stomach in A. rubens and here we show that in vivo injection of NGFFYamide causes a significant delay in the onset of feeding on prey. To investigate roles in regulating other aspects of starfish physiology, we examined the in vitro effects of NGFFYamide and found that it causes relaxation of acetylcholine-contracted apical muscle preparations and induction of tonic and phasic contraction of tube feet. Furthermore, analysis of the effects of in vivo injection of NGFFYamide on starfish locomotor activity revealed that it causes a significant reduction in mean velocity and distance traveled. Interestingly, experimental studies on mammals have revealed that NPS is an anxiolytic that suppresses appetite and induces hyperactivity in mammals. Our characterization of the actions of NGFFYamide in starfish indicates that NPS/NG peptide/CCAP-type signaling is an evolutionarily ancient regulator of feeding and locomotion.
RESUMO
Asparaginase reduces the levels of asparagine in blood, which is an essential amino acid for the proliferation of lymphoblastic malign cells. Asparaginase converts asparagine into aspartic acid and ammonia. The accumulation of ammonia in the bloodstream leads to hyperammonemia, described as one of the most significant side effects of asparaginase therapy. Therefore, there is a need for asparaginase formulations with the potential to reduce hyperammonemia. We incorporated 2 % of therapeutic enzyme in albumin-based capsules. The presence of asparaginase in the interface of bovine serum albumin (BSA) capsules showed the ability to hydrolyze the asparagine and retain the forming ammonia at the surface of the capsules. The incorporation of Poloxamer 407 in the capsule formulation further increased the ratio aspartic acid/ammonia from 1.92 to 2.46 (and 1.10 from the free enzyme), decreasing the levels of free ammonia. This capacity to retain ammonia can be due to electrostatic interactions and retention of ammonia at the surface of the capsules. The developed BSA/asparaginase capsules did not cause significant cytotoxic effect on mouse leukemic macrophage cell line RAW 264.7. The new BSA/asparaginase capsules could potentially be used in the treatment of acute lymphoblastic leukemia preventing hyperammonemia associated with acute lymphoblastic leukemia (ALL) treatment with asparaginase.
Assuntos
Amônia/metabolismo , Antineoplásicos/metabolismo , Asparaginase/metabolismo , Cápsulas/metabolismo , Portadores de Fármacos/metabolismo , Soroalbumina Bovina/metabolismo , Ultrassonografia , Animais , Antineoplásicos/toxicidade , Asparaginase/toxicidade , Bovinos , Sobrevivência Celular/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Camundongos , Células RAW 264.7RESUMO
Daily rhythms of feeding regulators are currently arousing research interest due to the relevance of the temporal harmony of endocrine regulators for growth and welfare in vertebrates. However, it is unknown the leptin circadian pattern in fish. The aim of this study is to investigate if leptin (gLep-aI and gLep-aII) expression is rhythmic in goldfish (Carassius auratus) liver and brain, and if such rhythms are driven by feeding time through a food entrainable oscillator. Fish maintained under 12-h light:12-h dark photoperiod and a scheduled feeding time showed 24-h locomotor activity and glycaemia rhythms. Moreover, hepatic gLep-aI and brain gLep-aI and gLep-aII expression were rhythmic with different daily profiles, showing a postprandial increase of leptin expression in the liver but not in the brain. Under constant light and different feeding regimes (scheduled fed at 10:00, 22:00 or randomly fed), feeding time synchronized daily rhythms in locomotor activity, glycaemia and clock gene expression (gPer1a, gPer3 and gCry3), but the rhythmic expression of hepatic gLep-aI and brain gLep-aII only remained in fed fish at 10:00. In summary, daily rhythms of leptin expression in goldfish are differently regulated at central and peripheral level, and they are not directly driven by clock genes. The role of food entrained oscillators on leptin expression rhythms in fish remains to be demonstrated.
Assuntos
Encéfalo/metabolismo , Ritmo Circadiano/fisiologia , Comportamento Alimentar , Regulação da Expressão Gênica , Carpa Dourada/metabolismo , Leptina/metabolismo , Fígado/metabolismo , Animais , Carpa Dourada/crescimento & desenvolvimento , Leptina/genética , Luz , Atividade Motora , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Oleoylethanolamide (OEA) is a bioactive lipid mediator, produced in the intestine and other tissues, which is involved in energy balance regulation in mammals, modulating feeding and lipid metabolism. The purpose of the present study was to investigate the presence and possible role of OEA in feeding regulation in goldfish (Carassius auratus). We assessed whether goldfish peripheral tissues and brain contain OEA and their regulation by nutritional status. OEA was detected in all studied tissues (liver, intestinal bulb, proximal intestine, muscle, hypothalamus, telencephalon and brainstem). Food deprivation (48 h) reduced intestinal OEA levels and levels increased upon re-feeding, suggesting that this compound may be involved in the short-term regulation of food intake in goldfish, as a satiety factor. Next, the effects of acute intraperitoneal administration of OEA on feeding, swimming and plasma levels of glucose and triglycerides were analysed. Food intake, swimming activity and circulating triglyceride levels were reduced by OEA 2 h post-injection. Finally, the possible interplay among OEA and other feeding regulators (leptin, cholecystokinin, ghrelin, neuropeptide Y, orexin and monoamines) was investigated. OEA actions on energy homeostasis in goldfish could be mediated, at least in part, through interactions with ghrelin and the serotonergic system, as OEA treatment reduced ghrelin expression in the intestinal bulb, and increased serotonergic activity in the telencephalon. In summary, our results indicate for the first time in fish that OEA could be involved in the regulation of feeding, swimming and lipid metabolism, suggesting a high conservation of OEA actions in energy balance throughout vertebrate evolution.
Assuntos
Ingestão de Alimentos/efeitos dos fármacos , Endocanabinoides/metabolismo , Endocanabinoides/farmacologia , Metabolismo dos Lipídeos/fisiologia , Neuropeptídeos/metabolismo , Ácidos Oleicos/metabolismo , Ácidos Oleicos/farmacologia , Hormônios Peptídicos/metabolismo , Animais , Glicemia , Endocanabinoides/análise , Privação de Alimentos/fisiologia , Carpa Dourada , Injeções Intraperitoneais , Ácidos Oleicos/análise , Natação/fisiologia , Triglicerídeos/sangueRESUMO
Several key functions of ghrelin are well conserved through vertebrate phylogeny. However, some of ghrelin's effects are contradictory and among teleosts only a limited number of species have been used in functional studies on food intake and foraging-related behaviors. Here we investigated the long-term effects of ghrelin on food intake, growth, swimming activity and aggressive contest behavior in one year old wild brown trout (Salmo trutta) using intraperitoneal implants. Food intake and swimming activity were individually recorded starting from day 1, and aggressive behavior was tested at day 11, after ghrelin implantation. Body weight and growth rate were measured from the beginning to the end of the experiment. Triglycerides and lipase activity in muscle and liver; monoaminergic activity in the telencephalon and brainstem; and neuropeptide Y (NPY) mRNA levels in the hypothalamus were analyzed. Ghrelin treatment was found to increase food intake and growth without modifying lipid deposition or lipid metabolism in liver and muscle. Ghrelin treatment led to an increased foraging activity and a trend towards a higher swimming activity. Moreover, ghrelin-treated fish showed a tendency to initiate more conflicts, but this motivation was not reflected in a higher ability to win the conflicts. No changes were observed in monoaminergic activity and NPY mRNA levels in the brain. Ghrelin is therefore suggested to act as an orexigenic hormone regulating behavior in juvenile wild brown trout. These actions are accompanied with an increased growth without the alteration of liver and muscle lipid metabolism and they do not seem to be mediated by changes in brain monoaminergic activity or hypothalamic expression of NPY.
Assuntos
Ingestão de Alimentos/efeitos dos fármacos , Grelina/farmacologia , Natação , Truta/crescimento & desenvolvimento , Agressão/efeitos dos fármacos , Animais , Monoaminas Biogênicas/metabolismo , Peso Corporal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Implantes de Medicamento , Grelina/administração & dosagem , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Músculos/efeitos dos fármacos , Músculos/metabolismo , Neuropeptídeo Y/biossíntese , Truta/metabolismoRESUMO
INTRODUCTION: Atypical ankle patterns of muscle activity during gait are commonly reported in patients with stroke. These findings can be due to changes between tibialis anterior (TA) and soleus (SOL) coactivation mechanisms. OBJECTIVE: To compare the electromyographic activity (EMGa) of SOL and TA muscles and antagonist coactivation (C) level in the contralateral (CONTRA) and ipsilateral (IPSI) limbs to the side of the stroke lesion during the stance phase of the gait cycle. METHODS: Twelve subjects with a stroke episode participated in this study. The electromyographic signal of TA and SOL and ground reaction forces were acquired while subjects walked at their self-selected speed. Values of ground reaction forces were used to divide the stance phase of gait into initial contact, midstance, and terminal stance. In each sub-phase, the magnitude of TA and SOL was calculated as well as the level of the antagonist C. RESULTS: Although no statistical differences were found, mean values of SOL EMGa were lower in the IPSI limb in all stance phases in relation to the CONTRA limb, and the opposite was observed in the TA EMGa. Moreover, higher mean levels of antagonist C were only found during the initial contact sub-phase in the CONTRA limb and in the other sub-phases in the IPSI limb. Besides, statistical differences were observed only during midstance. CONCLUSION: In stroke subjects, the antagonist C level during midstance of gait may reflect the dysfunction of the neuronal system over the IPSI limb.
Assuntos
Tornozelo/fisiopatologia , Marcha/fisiologia , Contração Muscular/fisiologia , Músculo Esquelético/fisiopatologia , Acidente Vascular Cerebral/fisiopatologia , Fenômenos Biomecânicos , Eletromiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/fisiologiaRESUMO
Background: Cardiovascular risk factors must be controlled since childhood. Aim: To assess the association of carotid intima media thickness (CIMT) with the components of the metabolic syndrome in Children. Material and Methods: Cross sectional assessment of 299 children aged 11.5 ± 0.9years (58% women) with and without metabolic syndrome components. Anthropometric parameters and blood pressure were measured and a blood sample was obtained to measure blood glucose and lipids. CIMT was measured using high resolution ultrasound. Results: Ninety three percent of children were post puberal, 64% were overweight and 25% had metabolic syndrome. Mean and maximum CIMT correlated with systolic blood pressure (r = 0.21 and 0.21 respectively p < 0.01). Children with a CIMTover the 75th percentile had higher blood pressure and lower HDL cholesterol. A stepwise logistic regression accepted both variables as predictors of CIMT with odds ratios for mean CIMT of 1.46 (1.19-1-79) and 0.81 (0.7-0.94) perfive units of change, respectively. Conclusions: In this group of children systolic blood pressure and HDL cholesterol are associated to CIMT.
Assuntos
Adolescente , Criança , Feminino , Humanos , Masculino , Pressão Sanguínea , Doenças Cardiovasculares/etiologia , Espessura Intima-Media Carotídea , HDL-Colesterol/sangue , Síndrome Metabólica/complicações , Chile/epidemiologia , Estudos Transversais , Obesidade/complicações , Obesidade/epidemiologia , Razão de Chances , Fatores de Risco , SístoleRESUMO
The aim of the present study was to investigate how photocycle and feeding-time cues regulate the daily expression of Per1a, Per2a, Per3, and Cry3 in the goldfish hindgut. For this purpose, we studied the daily rhythmicity of these genes in fish maintained under different lighting conditions and under different feeding regimes (scheduled or not). We also studied whether the timing of just one meal is able to reset the hindgut molecular clock. In a first experiment, randomly fed fish were divided into four groups and kept under different light conditions for 30 d: 12 h light and 12 h dark (12L:12D), an inverted photoperiod (12D:12L), constant darkness (24D), and constant light (24L). In a second study, fish maintained under 24L were divided into four groups fed at different time points for 35 d: (1) fish scheduled-fed once a day (at 10:00 h); (2) fish fed with a 12-h shifted schedule (at 22:00 h), (3) fish fed at 10:00 h throughout the experiment, except the last day when fed at 22:00 h; and (4) a randomly fed group of fish. Fish were sacrificed every 6 h throughout a 24-h cycle. In both experiments, gPer1a, gPer2a, gPer3, and gCry3 transcripts were quantified using Real Time-qPCR in the hindgut. Results show the clock genes gPer1a, gPer2a, and gCry3 are synchronized by both zeitgebers, the photocycle and feeding regime, in goldfish hindgut. Moreover, such clock genes anticipate light-on and food delivery, when these cues appear in a cyclic manner. In the absence of both zeitgebers, gCry3 and gPer2a rhythmicity disappeared. In contrast, the gPer1 rhythm was maintained under 24L and random feeding conditions, but not always, suggesting that food when randomly supplied is able to reset the clock depending on other factors, such as the energetic and metabolic conditions of the fish. The expression of gPer2a was not activated during the light phase of the cycle, suggesting the hindgut of goldfish is a non-direct photosensitive organ. In contrast to the other three genes, gPer3 expression in the goldfish hindgut seemed to be dependent on the timing of the last food delivery, even in the presence of a photocycle. This gene was the only one that maintained daily rhythms under both constant lighting conditions (24D and 24L), although with lower amplitude than when a photocycle was present. This indicates that, although the acrophase (peak time) of the gPer3 expression rhythm seems to be driven by feeding time, there is an interaction of both zeitgebers, food and light, to regulate its expression. In conclusion, present data indicate: (1) the hindgut of goldfish can be synchronized in vivo by both the photocycle and feeding time; (2) food is a potent signal that entrains this peripheral oscillator; and (3) both environmental cues seems to target different elements of the molecular clock.
Assuntos
Relógios Biológicos , Comportamento Alimentar , Trato Gastrointestinal/metabolismo , Regulação da Expressão Gênica , Fotoperíodo , Animais , Proteínas CLOCK/metabolismo , Carpa Dourada/fisiologia , Iluminação , Fatores de TempoRESUMO
Leptin is a hormone involved in feeding and body weight regulation in vertebrates, but the relationship between energy status and leptin has not been clearly established in fish. The aim of this study was to investigate in a teleost, the goldfish (Carassius auratus), the tissue expression pattern of two leptins (gLep-aI and gLep-aII) and leptin receptor (gLepR); and the effect of feeding on expression of these genes. Leptin system expression in goldfish was firstly analyzed in fish under overfeeding (2 weeks) or fasting (1 week), and secondly, at different postfeeding times (0, 3, 6, 9 and 12h). Goldfish has two Lep-a paralog genes, gLep-aI was widely expressed in central and peripheral tissues, whereas gLep-aII was preferentially expressed in brain. This different distribution pattern of leptins suggests that they can play different physiological roles in goldfish. The gLepR mRNA was ubiquitous expressed, with the highest expression in the telencephalon and hypothalamus. No significant differences in the leptin system expression were found among control, overfed and fasting groups, suggesting an apparent lack of correlation between nutritional status and leptin system in goldfish. Hepatic expression of gLep-aI significantly increased 9h after feeding time, while hypothalamic leptin system expression did not change after feeding. In summary, leptin in goldfish could signal short-term changes in food intake, as postprandial satiety, but seems to be independent of fasting/overfeeding conditions in this teleost. The widespread distribution of leptins and leptin receptor in goldfish strongly supports that this hormone may have pleitropic actions in fish.
Assuntos
Ingestão de Alimentos/genética , Regulação da Expressão Gênica , Carpa Dourada/metabolismo , Leptina/metabolismo , Receptores para Leptina/metabolismo , Animais , Peso Corporal , Jejum/metabolismo , Feminino , Pleiotropia Genética , Carpa Dourada/genética , Hipotálamo/fisiologia , Leptina/genética , Fígado/fisiologia , Masculino , Especificidade de Órgãos , Hipernutrição/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptores para Leptina/genética , Telencéfalo/fisiologiaRESUMO
BACKGROUND: Cardiovascular risk factors must be controlled since childhood. AIM: To assess the association of carotid intima media thickness (CIMT) with the components of the metabolic syndrome in Children. MATERIAL AND METHODS: Cross sectional assessment of 299 children aged 11.5 ± 0.9 years (58% women) with and without metabolic syndrome components. Anthropometric parameters and blood pressure were measured and a blood sample was obtained to measure blood glucose and lipids. CIMT was measured using high resolution ultrasound. RESULTS: Ninety three percent of children were post puberal, 64% were overweight and 25% had metabolic syndrome. Mean and maximum CIMT correlated with systolic blood pressure (r = 0.21 and 0.21 respectively p < 0.01). Children with a CIMT over the 75th percentile had higher blood pressure and lower HDL cholesterol. A stepwise logistic regression accepted both variables as predictors of CIMT with odds ratios for mean CIMT of 1.46 (1.19-1-79) and 0.81 (0.7-0.94) per five units of change, respectively. CONCLUSIONS: In this group of children systolic blood pressure and HDL cholesterol are associated to CIMT.
Assuntos
Pressão Sanguínea , Doenças Cardiovasculares/etiologia , Espessura Intima-Media Carotídea , HDL-Colesterol/sangue , Síndrome Metabólica/complicações , Adolescente , Criança , Chile/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Obesidade/complicações , Obesidade/epidemiologia , Razão de Chances , Fatores de Risco , SístoleRESUMO
O mercúrio, elemento químico considerado não essencial a qualquer processo metabólico, é facilmente acumulado na maioria dos organismos. Ocorre naturalmente em formas orgânicas e inorgânicas, nos estados sólido, dissolvido e gasoso. Seu ciclo biogeoquímico envolve processos que ocorrem no solo, na água e na atmosfera. Em 2002, descobriu-se mercúrio elementar na zona rural do município de Descoberto, Minas Gerais, onde moram cerca de 70 famílias, e sua origem parece estar associada à exploração de ouro, que existiu na região no século 19. Neste trabalho, foram escolhidas três áreas para identificar possível contaminação da água, solo, sedimento e peixes por mercúrio, bem como para estabelecer valores de referência local e contraprova de resultados obtidos anteriormente. Verificaram-se elevadas concentrações no solo (0,26 a 0,55 mg.kg-1), sedimentos (0,13 a 0,61 mg.kg-1) e água (< 0,2 a 2,10 µg.L-1).
Mercury is a chemical element considered unessential to any metabolic process; however, it is easily accumulated in most organisms. It is naturally found in both organic and inorganic forms in solid, liquid and vapor states. Its biogeochemical cycle involves processes occurring in the soil, water and the atmosphere. In 2002, elementary mercury was found in the city of Descoberto, Minas Gerais, Brazil, where 70 families live, and its origin may be related to gold exploration that happened in this region in the 19th century. In this work, three areas were chosen to identify a possible mercury contamination of water, soil, sediment and fish samples and to establish local reference values and counter-evidence of the data previously obtained. Based on the results, high mercury concentrations in soil (0.26 to 0.55 mg.kg-1), sediments (0.13 to 0.61 mg.kg-1) and water (< 0.2 to 2,10 µg.L-1) were verified.