RESUMO
Chagas disease is potentially life-threatening and caused by the protozoan parasite Trypanosoma cruzi. The parasite cannot synthesize some lipids and depends on the uptake of these lipids from its vertebrate and invertebrate hosts. To achieve this, T. cruzi may need to modify the physiology of the insect host for its own benefit. In this study, we investigated the interaction of T. cruzi (Y strain) with its insect vector Rhodnius prolixus and how it manipulates the vector lipid metabolism. We observed a physiological change in lipid flux in of infected insects. In the fat body of infected insects, triacylglycerol levels decreased by 80.6% and lipid storage droplet-1(LSD-1) mRNA levels were lower, when compared to controls. Lipid sequestration by infected midguts led to increased levels of 5' AMP-activated protein kinase (AMPK) phosphorylation and activation in the fat body, inhibiting the synthesis of fatty acids and stimulating their oxidation. This led to reduced lipid levels in the fat body of infected insets, despite the fact that T. cruzi does not colonize this tissue. There was a 3-fold increase, in lipid uptake and synthesis in the midgut of infected insects. Finally, our results suggest that the parasite modifies the lipid flux and metabolism of its vector R. prolixus through the increase in lipid delivery from the fat body to midgut that are then scavenge by T cruzi.
Assuntos
Doença de Chagas , Rhodnius , Trypanosoma cruzi , Animais , Doença de Chagas/parasitologia , Metabolismo dos Lipídeos , Fosfolipídeos/metabolismo , Rhodnius/parasitologia , Trypanosoma cruzi/fisiologiaRESUMO
The gut microbiota affects the host's metabolic phenotype, impacting health and disease. The gut-brain axis unites the intestine with the centers of hunger and satiety, affecting the eating behavior. Deregulation of this axis can lead to obesity onset. Litter size reduction is a well-studied model for infant obesity because it causes overnutrition and programs for obesity. We hypothesize that animals raised in small litters (SL) have altered circuitry between the intestine and brain, causing hyperphagia. We investigated vagus nerve activity, the expression of c-Fos, brain-derived neurotrophic factor (BDNF), gastrointestinal (GI) hormone receptors, and content of bacterial phyla and short-chain fatty acids (SCFAs) in the feces of adult male and female Wistar rats overfed during lactation. On the 3rd day after birth, litter size was reduced to 3 pups/litter (SL males or SL females) until weaning. Controls had normal litter size (10 pups/litter: 5 males and 5 females). The rats were killed at 5 months of age. The male and female offspring were analyzed separately. The SL group of both sexes showed higher food consumption and body adiposity than the respective controls. SL animals presented dysbiosis (increased Firmicutes, decreased Bacteroidetes) and had increased vagus nerve activity. Only the SL males had decreased hypothalamic GLP-1 receptor expression, while only the SL females had lower acetate and propionate in the feces and higher CCK receptor expression in the hypothalamus. Thus, overfeeding during lactation differentially changes the gut-brain axis, contributing to hyperphagia of the offspring of both sexes.
Assuntos
Eixo Encéfalo-Intestino , Hiperfagia/microbiologia , Tamanho da Ninhada de Vivíparos , Adiposidade , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Feminino , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Hiperfagia/metabolismo , Hiperfagia/fisiopatologia , Hipotálamo/metabolismo , Hipotálamo/fisiologia , Masculino , Proteínas Proto-Oncogênicas c-fos/metabolismo , Ratos , Ratos Wistar , Receptores da Colecistocinina/metabolismo , Nervo Vago/metabolismo , Nervo Vago/fisiologiaRESUMO
Nicotine is an endocrine disruptor and imprinting factor during breastfeeding that can cause food intake imbalance in the adulthood. As nicotine affects the intestinal microbiota, altering the composition of the bacterial communities and short-chain fatty acids (SCFAs) synthesis in a sex-dependent manner, we hypothesized that nicotine could program the gut-brain axis, consequently modifying the eating pattern of adult male and female rats in a model of maternal nicotine exposure (MNE) during breastfeeding. Lactating Wistar rat dams received minipumps that release 6 mg/kg/day of nicotine (MNE group) or saline for 14 days. The progeny received standard diet from weaning until euthanasia (26 weeks of age). We measured: in vivo electrical activity of the vagus nerve; c-Fos expression in the nucleus tractus solitarius, gastrointestinal peptides receptors, intestinal brain-derived neurotrophic factor (BDNF), SCFAs and microbiota. MNE females showed hyperphagia despite normal adiposity, while MNE males had unchanged food intake, despite obesity. Adult MNE offspring showed decreased Bacteroidetes and increased Firmicutes, Actinobacteria and Proteobacteria. MNE females had lower fecal acetate while MNE males showed higher vagus nerve activity. In summary nicotine exposure through the milk induces long-term intestinal dysbiosis, which may affect eating patterns of adult offspring in a sex-dependent manner.
Assuntos
Eixo Encéfalo-Intestino/efeitos dos fármacos , Comportamento Alimentar/fisiologia , Nicotina/toxicidade , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Animais , Disbiose/induzido quimicamente , Disbiose/microbiologia , Feminino , Lactação/fisiologia , Masculino , Gravidez , Ratos , Ratos WistarRESUMO
AIMS: Bisphenol A (BPA), an endocrine disruptor used in industrial applications, has been detected in both placenta and milk. We studied the effects of BPA exposure during pregnancy and lactation on body composition, palatable food intake, biochemical, hormonal and behavioral profiles of young and adult Wistar rat offspring. MAIN METHODS: Female rats were divided into: control, BPA10 (10⯵g/kg/day) and BPA50 (50⯵g/kg/day). BPA was administered by gavage to dams from gestation until the end of lactation. Euthanasia occurred at weaning [postnatal day (PN) 21] or adulthood (PN180). KEY FINDINGS: At weaning, BPA10 female pups had higher plasma cholesterol and triacylglycerol. BPA10 male pups showed lower plasma T3. BPA10 pups of both sexes had higher plasma progesterone, testosterone and estradiol. At adulthood, females of both BPA groups had lower food intake and higher insulinemia, whereas males had lower visceral fat, lower progesterone and testosterone concentrations. BPA10 females and males had lower T4 levels, while only males showed lower estradiol. BPA50 females showed lower fat mass, higher lean mass and lower corticosteronemia, while males had lower food intake. In the feeding study, BPA10 males ate more fat at 30â¯min, while BPA10 females and males ingested less fat after 12â¯h. BPA10 females showed hyperactivity while both groups showed less exploration. SIGNIFICANCE: Maternal exposure to BPA during gestation and lactation, even at low doses, induces life-long changes in the regulation of metabolic homeostasis of the progeny, affects sex steroids and thyroid hormones levels, compromises behavior, but does not lead to obesity or dyslipidemia.
Assuntos
Compostos Benzidrílicos/toxicidade , Hormônios Esteroides Gonadais/metabolismo , Exposição Materna/efeitos adversos , Fenóis/toxicidade , Comportamento Sexual/efeitos dos fármacos , Hormônios Tireóideos/metabolismo , Poluentes Ocupacionais do Ar/toxicidade , Animais , Animais Recém-Nascidos , Feminino , Masculino , Ratos , Ratos WistarRESUMO
C8-desaturated and C9-methylated glucosylceramide (GlcCer) is a fungal-specific sphingolipid that plays an important role in the growth and virulence of many species. In this work, we investigated the contribution of Aspergillus nidulans sphingolipid Δ8-desaturase (SdeA), sphingolipid C9-methyltransferases (SmtA/SmtB) and glucosylceramide synthase (GcsA) to fungal phenotypes, sensitivity to Psd1 defensin and Galleria mellonella virulence. We showed that ΔsdeA accumulated C8-saturated and unmethylated GlcCer, while gcsA deletion impaired GlcCer synthesis. Although increased levels of unmethylated GlcCer were observed in smtA and smtB mutants, ΔsmtA and wild-type cells showed a similar 9,Me-GlcCer content, reduced by 50% in the smtB disruptant. The compromised 9,Me-GlcCer production in the ΔsmtB strain was not accompanied by reduced filamentation or defects in cell polarity. When combined with the smtA deletion, smtB repression significantly increased unmethylated GlcCer levels and compromised filamentous growth. Furthermore, sdeA and gcsA mutants displayed growth defects and raft mislocalization, which were accompanied by reduced neutral lipids levels and attenuated G. mellonella virulence in the ΔgcsA strain. Finally, ΔsdeA and ΔgcsA showed increased resistance to Psd1, suggesting that GlcCer synthesis and fungal sphingoid base structure specificities are relevant not only to differentiation but also to proper recognition by this antifungal defensin.
Assuntos
Aspergillus nidulans/metabolismo , Glucosilceramidas/metabolismo , Glucosiltransferases/metabolismo , Microdomínios da Membrana/metabolismo , Antifúngicos/química , Aspergillus nidulans/genética , Aspergillus nidulans/crescimento & desenvolvimento , Defensinas/metabolismo , Glucosilceramidas/química , Glucosilceramidas/genética , Glucosiltransferases/química , Glucosiltransferases/genética , Metilação , Metiltransferases/genética , Oxirredutases/metabolismo , Esfingolipídeos/química , Esfingolipídeos/metabolismoRESUMO
Leishmaniasis is a set of clinically distinct infectious diseases caused by Leishmania, a genus of flagellated protozoan parasites, that affects ~12 million people worldwide, with ~2 million new infections annually. Plants are known to produce substances to defend themselves against pathogens and predators. In the genus Lycopersicon, which includes the tomato, L. esculentum, the main antimicrobial compound is the steroidal glycoalkaloid α-tomatine. The loss of the saccharide side-chain of tomatine yields the aglycone tomatidine. In the present study, we investigated the effects of tomatidine on the growth, mitochondrial membrane potential, sterol metabolism, and ultrastructure of Leishmania amazonensis promastigotes. Tomatidine (0·1 to 5 µM) inhibited parasite growth in a dose-dependent manner (IC(50)=124±59 nM). Transmission electron microscopy revealed lesions in the mitochondrial ultrastructure and the presence of large vacuoles and lipid storage bodies in the cytoplasm. These structural changes in the mitochondria were accompanied by an effective loss of mitochondrial membrane potential and a decrease in ATP levels. An analysis of the neutral lipid content revealed a large depletion of endogenous 24-alkylated sterols such as 24-methylene-cholesta-5, 7-dien-3ß-ol (5-dehydroepisterol), with a concomitant accumulation of cholesta-8, 24-dien-3ß-ol (zymosterol), which implied a perturbation in the cellular lipid content. These results are consistent with an inhibition of 24-sterol methyltransferase, an important enzyme responsible for the methylation of sterols at the 24 position, which is an essential step in the production of ergosterol and other 24-methyl sterols.
Assuntos
Antiparasitários/farmacologia , Leishmania/efeitos dos fármacos , Esteróis/biossíntese , Tomatina/análogos & derivados , Trifosfato de Adenosina/metabolismo , LDL-Colesterol/química , LDL-Colesterol/metabolismo , Radioisótopos do Iodo/química , Leishmania/metabolismo , Leishmania/ultraestrutura , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Tomatina/química , Tomatina/farmacologiaRESUMO
Leishmaniasis is a tropical disease caused by protozoan parasites of the genus Leishmania which affects 12 million people worldwide. The discovery of drugs for the treatment of leishmaniasis is a pressing concern in global health programs. The aim of this study aim was to evaluate the leishmanicidal effect of piperine and its derivatives/analogues on Leishmania amazonensis. Our results showed that piperine and phenylamide are active against promastigotes and amastigotes in infected macrophages. Both drugs induced mitochondrial swelling, loose kinetoplast DNA, and led to loss of mitochondrial membrane potential. The promastigote cell cycle was also affected with an increase in the G1 phase cells and a decrease in the S-phase cells, respectively, after piperine and phenylamide treatment. Lipid analysis of promastigotes showed that piperine reduced triglyceride, diacylglycerol, and monoacylglycerol contents, whereas phenylamide only reduced diacylglycerol levels. Both drugs were deemed non toxic to macrophages at 50 µM as assessed by XTT (sodium 2,3,-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)-carbonyl]-2H-tetrazolium inner salt), Trypan blue exclusion, and phagocytosis assays, whereas low toxicity was noted at concentrations higher than 150 µM. None of the drugs induced nitric oxide (NO) production. By contrast, piperine reduced NO production in activated macrophages. The isobologram analysis showed that piperine and phenylamide acted synergistically on the parasites suggesting that they affect different target mechanisms. These results indicate that piperine and its phenylamide analogue are candidates for development of drugs for cutaneous leishmaniasis treatment.
Assuntos
Alcaloides/uso terapêutico , Benzodioxóis/uso terapêutico , Leishmania/efeitos dos fármacos , Leishmaniose/tratamento farmacológico , Macrófagos/efeitos dos fármacos , Fitoterapia , Piper/química , Piperidinas/uso terapêutico , Alcamidas Poli-Insaturadas/uso terapêutico , Tripanossomicidas/uso terapêutico , Alcaloides/farmacologia , Amidas/farmacologia , Amidas/uso terapêutico , Benzodioxóis/farmacologia , Ciclo Celular/efeitos dos fármacos , Frutas , Glicerídeos/metabolismo , Leishmania/crescimento & desenvolvimento , Leishmania/metabolismo , Leishmaniose/parasitologia , Leishmaniose Cutânea/tratamento farmacológico , Metabolismo dos Lipídeos/efeitos dos fármacos , Macrófagos/parasitologia , Mitocôndrias/efeitos dos fármacos , Óxido Nítrico/biossíntese , Piperidinas/farmacologia , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Alcamidas Poli-Insaturadas/farmacologia , Tripanossomicidas/farmacologiaRESUMO
Lipid transport in arthropods is achieved by highly specialized lipoproteins, which resemble those described in vertebrate blood. Here we describe purification and characterization of the lipid-apolipoprotein complex, lipophorin (Lp), from adults and larvae of the cowpea weevil Callosobruchus maculatus. We also describe the Lp-mediated lipid transfer to developing oocytes. Lps were isolated from homogenates of C. maculatus larvae and adults by potassio bromide gradient and characterized with respect to physicochemical properties and lipid content. The weevil Lp (465 kDa) and larval Lp (585 kDa), with hydrated densities of 1.22 and 1.14 g/mL, contained 34 and 56 percent lipids and 9 and 7 percent carbohydrates, respectively. In both Lps, mannose was the predominant monosaccharide detected by paper chromatography. SDS-PAGE revealed two apolipoproteins in each Lp with molecular masses of 225 kDa (apolipoprotein-I) and 79 kDa (apolipoprotein-II). The lipids were extracted and analyzed by thin-layer chromatography. The major phospholipids found were phosphatidylserine, phosphatidylcholine and phosphatidylethanolamine in adult Lp, and phosphatidylcholine, phosphatidylethanolamine and sphingomyelin in larval Lp. Hydrocarbons, fatty acids and triacylglycerol were the major neutral lipids found in both Lps. Lps labeled in the protein moiety with radioactive iodine (125I-iodine) or in the lipid moiety with fluorescent lipids revealed direct evidence of endocytic uptake of Lps in live oocytes of C. maculatus.
Assuntos
Animais , Feminino , Hidrocarbonetos/análise , Metabolismo dos Lipídeos/fisiologia , Lipoproteínas/química , Oócitos/crescimento & desenvolvimento , Fosfolipídeos/química , Gorgulhos/química , Apolipoproteínas/química , Apolipoproteínas/isolamento & purificação , Apolipoproteínas/metabolismo , Transporte Biológico , Endocitose/fisiologia , Lipoproteínas/isolamento & purificação , Lipoproteínas/metabolismo , Oócitos/metabolismo , Oogênese/fisiologia , Fosfolipídeos/isolamento & purificação , Fosfolipídeos/metabolismo , Gorgulhos/metabolismoRESUMO
Lipid transport in arthropods is achieved by highly specialized lipoproteins, which resemble those described in vertebrate blood. Here we describe purification and characterization of the lipid-apolipoprotein complex, lipophorin (Lp), from adults and larvae of the cowpea weevil Callosobruchus maculatus. We also describe the Lp-mediated lipid transfer to developing oocytes. Lps were isolated from homogenates of C. maculatus larvae and adults by potassio bromide gradient and characterized with respect to physicochemical properties and lipid content. The weevil Lp (465 kDa) and larval Lp (585 kDa), with hydrated densities of 1.22 and 1.14 g/mL, contained 34 and 56% lipids and 9 and 7% carbohydrates, respectively. In both Lps, mannose was the predominant monosaccharide detected by paper chromatography. SDS-PAGE revealed two apolipoproteins in each Lp with molecular masses of 225 kDa (apolipoprotein-I) and 79 kDa (apolipoprotein-II). The lipids were extracted and analyzed by thin-layer chromatography. The major phospholipids found were phosphatidylserine, phosphatidylcholine and phosphatidylethanolamine in adult Lp, and phosphatidylcholine, phosphatidylethanolamine and sphingomyelin in larval Lp. Hydrocarbons, fatty acids and triacylglycerol were the major neutral lipids found in both Lps. Lps labeled in the protein moiety with radioactive iodine (125I-iodine) or in the lipid moiety with fluorescent lipids revealed direct evidence of endocytic uptake of Lps in live oocytes of C. maculatus.
Assuntos
Hidrocarbonetos/análise , Metabolismo dos Lipídeos/fisiologia , Lipoproteínas/química , Oócitos/crescimento & desenvolvimento , Fosfolipídeos/química , Gorgulhos/química , Animais , Apolipoproteínas/química , Apolipoproteínas/isolamento & purificação , Apolipoproteínas/metabolismo , Transporte Biológico , Endocitose/fisiologia , Feminino , Lipoproteínas/isolamento & purificação , Lipoproteínas/metabolismo , Oócitos/metabolismo , Oogênese/fisiologia , Fosfolipídeos/isolamento & purificação , Fosfolipídeos/metabolismo , Gorgulhos/metabolismoRESUMO
One fundamental step of Leishmania-macrophage interaction is the phase of parasite internalization through an endocytic process, with the formation of the parasitophorous vacuole (PV). The present study analyzed this process using two approaches. First, to investigate the host cell proteins which take part in this compartment, the macrophage surface was biotinilated and allowed to interact with both Leishmania forms, the PV was then isolated, and the biotinilated proteins were analyzed by Western blot. The results obtained showed that the isolated PV from macrophages infected for 60 min with infective promastigotes displayed high molecular weight proteins, 220 kDa and 180 kDa, contrary to the isolated PV obtained from amastigotes. The isolated PV from amastigotes, after 60 min interaction, displayed a faint, biotinilated protein profile, in contrast to the PV containing amastigote which, after 30 min interaction, displayed a strong protein profile in the range of 120 kDa and 40-60 kDa. The biotinilated protein profile may represent proteins distributed in the PV membrane and may also correspond to biotinilated proteins incorporated by the intracellular parasite, as observed by confocal microscopy. In a second approach, to investigate the PV phospholipid composition, macrophages were incubated with (32)P, allowed to interact with the parasites, and the isolated PV was then processed for phospholipid analysis by thin layer chromatography and scintillation counting. An increase in the levels of lysophosphatidylcholine was observed in infected macrophages. The isolated PV from infective promastigotes and amastigotes, after 60 min interaction, displayed high levels of phosphatidylcholine. Then the PV was ruptured and the intravacuolar parasite's (32)P phospholipid composition was analyzed by TLC; and labeling of the parasites was found, suggesting that phospholipids from the macrophage are transferred to the parasite. Taken together, the results obtained show that several proteins and phospholipids found in the plasma membrane of the macrophage are also found in the PV compartment.