RESUMEN
BACKGROUND: Sickle cell disease patients display priapism that may progress to erectile dysfunction. However, little is known about the pathophysiological alterations of corpus cavernosum in sickle cell disease. OBJECTIVE: Thus, this study aimed to evaluate the functional and molecular alterations of sympathetic machinery and nitric oxide-cyclic guanosine monophosphate signaling pathway in Townes transgenic sickle cell disease mice. METHODS: Concentration-response curves to contractile (phenylephrine) and relaxant agents (acetylcholine and sodium nitroprusside) were obtained in corpus cavernosum strips from sickle and C57BL/6 (control) mice. Neurogenic contractions and nitrergic relaxations were obtained using electrical-field stimulation. Measurements of endothelial nitric oxide synthase (eNOS), neuronal nitric oxide synthase (nNOS), phosphodiesterase-5 (PDE5) and α1A-, α1B- and α1D-adrenoceptor mRNA expressions and reactive-oxygen species were performed. Tyrosine hydroxylase phosphorylated at Ser-31 and total tyrosine hydroxylase protein expressions in cavernosal tissues were also measured. RESULTS: The neurogenic contractions were higher in the sickle cell disease group, in association with elevated tyrosine hydroxylase phosphorylated at Ser-31 and total tyrosine hydroxylase protein expression, as well as increased tyrosine hydroxylase mRNA expression. Likewise, phenylephrine-induced contractions were greater in the sickle mice, whereas α1A-, α1B- and α1D-adrenoceptor mRNA expression remained unchanged. Cavernosal relaxations to acetylcholine, sodium nitroprusside and EFS were higher in sickle mice, accompanied by decreased eNOS and nNOS, along with lower PDE5 mRNA expression. An increase of about 40% in reactive-oxygen species generation in corpus cavernosum from sickle mice was also detected. CONCLUSION: Our study shows that decreased nitric oxide bioavailability in erectile tissue due to increased oxidative stress leads to both sympathetic hyperactivity and dysregulation of nitric oxide signaling in corpus cavernosum from Townes sickle mice.
Asunto(s)
Anemia de Células Falciformes/fisiopatología , Estrés Oxidativo , Pene/fisiopatología , Sistema Nervioso Simpático/fisiopatología , Tirosina 3-Monooxigenasa/metabolismo , Acetilcolina/farmacología , Anemia de Células Falciformes/genética , Anemia de Células Falciformes/metabolismo , Animales , Western Blotting , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 5/genética , Fosfodiesterasas de Nucleótidos Cíclicos Tipo 5/metabolismo , Relación Dosis-Respuesta a Droga , Estimulación Eléctrica , Expresión Génica/efectos de los fármacos , Técnicas In Vitro , Masculino , Ratones Endogámicos C57BL , Ratones Transgénicos , Óxido Nítrico Sintasa de Tipo I/genética , Óxido Nítrico Sintasa de Tipo I/metabolismo , Óxido Nítrico Sintasa de Tipo III/genética , Óxido Nítrico Sintasa de Tipo III/metabolismo , Nitroprusiato/farmacología , Pene/efectos de los fármacos , Pene/inervación , Fosforilación/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Receptores Adrenérgicos/genética , Receptores Adrenérgicos/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Tirosina 3-Monooxigenasa/genética , Vasodilatadores/farmacologíaRESUMEN
UNLABELLED: Enteric pathogens such as enterohemorrhagic Escherichia coli (EHEC) and Citrobacter rodentium, which is largely used as a surrogate EHEC model for murine infections, are exposed to several host neurotransmitters in the gut. An important chemical exchange within the gut involves the neurotransmitters epinephrine and/or norepinephrine, extensively reported to increase virulence gene expression in EHEC, acting through two bacterial adrenergic sensors: QseC and QseE. However, EHEC is unable to establish itself and cause its hallmark lesions, attaching and effacing (AE) lesions, on murine enterocytes. To address the role of these neurotransmitters during enteric infection, we employed C. rodentium Both EHEC and C. rodentium harbor the locus of enterocyte effacement (LEE) that is necessary for AE lesion formation. Here we show that expression of the LEE, as well as that of other virulence genes in C. rodentium, is also activated by epinephrine and/or norepinephrine. Both QseC and QseE are required for LEE gene activation in C. rodentium, and the qseC and qseE mutants are attenuated for murine infection. C. rodentium has a decreased ability to colonize dopamine ß-hydroxylase knockout (Dbh(-/-)) mice, which do not produce epinephrine and norepinephrine. Both adrenergic sensors are required for C. rodentium to sense these neurotransmitters and activate the LEE genes during infection. These data indicate that epinephrine and norepinephrine are sensed by bacterial adrenergic receptors during enteric infection to promote activation of their virulence repertoire. This is the first report of the role of these neurotransmitters during mammalian gastrointestinal (GI) infection by a noninvasive pathogen. IMPORTANCE: The epinephrine and norepinephrine neurotransmitters play important roles in gut physiology and motility. Of note, epinephrine and norepinephrine play a central role in stress responses in mammals, and stress has profound effects on GI function. Bacterial enteric pathogens exploit these neurotransmitters as signals to coordinate the regulation of their virulence genes. The bacterial QseC and QseE adrenergic sensors are at the center of this regulatory cascade. C. rodentium is a noninvasive murine pathogen with a colonization mechanism similar to that of EHEC, enabling the investigation of host signals in mice. The presence of these neurotransmitters in the gut is necessary for C. rodentium to fully activate its virulence program, in a QseC/QseE-dependent manner, to successfully colonize its murine host. Our study data provide the first example of epinephrine and norepinephrine signaling within the gut to stimulate infection by a bacterial pathogen in a natural animal infection.
Asunto(s)
Citrobacter rodentium/patogenicidad , Infecciones por Enterobacteriaceae/microbiología , Escherichia coli Enterohemorrágica/patogenicidad , Tracto Gastrointestinal/microbiología , Regulación Bacteriana de la Expresión Génica , Fosfoproteínas/genética , Receptores Adrenérgicos/genética , Animales , Citrobacter rodentium/genética , Dopamina beta-Hidroxilasa/genética , Enterocitos/microbiología , Escherichia coli Enterohemorrágica/genética , Epinefrina/genética , Epinefrina/metabolismo , Infecciones por Escherichia coli , Proteínas de Escherichia coli/genética , Genes Bacterianos , Interacciones Huésped-Patógeno , Ratones , Ratones Noqueados , Norepinefrina/genética , Norepinefrina/metabolismo , Vasoconstrictores , Virulencia/genéticaRESUMEN
The venom gland of viperid snakes has a central lumen where the venom produced by secretory cells is stored. When the venom is lost from the gland, the secretory cells are activated and new venom is produced. The production of new venom is triggered by the action of noradrenaline on both alpha(1)- and beta-adrenoceptors in the venom gland. In this study, we show that venom removal leads to the activation of transcription factors NFkappaB and AP-1 in the venom gland. In dispersed secretory cells, noradrenaline activated both NFkappaB and AP-1. Activation of NFkappaB and AP-1 depended on phospholipase C and protein kinase A. Activation of NFkappaB also depended on protein kinase C. Isoprenaline activated both NFkappaB and AP-1, and phenylephrine activated NFkappaB and later AP-1. We also show that the protein composition of the venom gland changes during the venom production cycle. Striking changes occurred 4 and 7 days after venom removal in female and male snakes, respectively. Reserpine blocks this change, and the administration of alpha(1)- and beta-adrenoceptor agonists to reserpine-treated snakes largely restores the protein composition of the venom gland. However, the protein composition of the venom from reserpinized snakes treated with alpha(1)- or beta-adrenoceptor agonists appears normal, judging from SDS-PAGE electrophoresis. A sexual dimorphism in activating transcription factors and activating venom gland was observed. Our data suggest that the release of noradrenaline after biting is necessary to activate the venom gland by regulating the activation of transcription factors and consequently regulating the synthesis of proteins in the venom gland for venom production.
Asunto(s)
Bothrops/fisiología , Venenos de Crotálidos/metabolismo , Regulación de la Expresión Génica/fisiología , Sistema Nervioso Simpático/fisiología , Factores de Transcripción/metabolismo , Animales , Venenos de Crotálidos/química , Femenino , Masculino , FN-kappa B/genética , FN-kappa B/metabolismo , Proteínas/genética , Proteínas/metabolismo , Receptores Adrenérgicos/genética , Receptores Adrenérgicos/metabolismo , Reserpina , Factor de Transcripción AP-1/genética , Factor de Transcripción AP-1/metabolismoRESUMEN
OBJECTIVE: To evaluate the effect of diet and PPARgamma2 and beta2-adrenergic receptor genes on energy metabolism and body composition in obese women. MATERIAL AND METHODS: 60 obese women, aged 34.59 +/- 7.56 years were studied at the Department of Physiology and Nutrition at Navarra University. Anthropometric, biochemical, metabolic and molecular evaluations were carried out, and the women were submitted to short-term and long-term hypocaloric diets, varying the macronutrients. The groups were formed according to gene polymorphism, as follows: Pro12Pro(PPARgamma2)/Gln27Gln (beta2-adrenergic receptor genes) - A, Pro12Pro (PPARgamma2)/Gln27Glu (beta2-adrenergic receptor genes) - B, Pro12Pro (PPARgamma2)/ Glu27Glu (beta2-adrenergic receptor genes)-C and Pro1Ala (PPARgamma2)/Gln27Glu beta2-adrenergic receptor genes) - D. RESULTS: In group A, fat oxidation was correlated positively with body mass index (BMI), but an increase in fat and saturated fatty acids (SFA) in the diet did not reflect in increased oxidation. In group B, total fat and SFA intake did not lead to fat oxidation increase. In group C, fat and complex carbohydrates (CHO) resulted in lower fat oxidation, and long-term increase of monounsaturated fatty acid (MUFA) intake resulted in increase of CHO oxidation and smaller weight loss. In group D, greater energy expenditure was obtained after diet high in SFA in a short-term, and fat basal and postprandial oxidation correlated positively with its intake. Hypocaloric diet high in polyunsaturated fatty acid (PUFA) resulted in increase of fat oxidation. CONCLUSIONS: Polymorphism in PPARgamma2 gene resulted in increased fat oxidation, regardless of genotype of beta2-adrenergic receptor gene. It is recommended control of the total intake of fats and SFA in Pro12Pro/Gln27Gln and Pro12Pro/Gln27Glu, and complex CHO and MUFA in Pro12Pro/Glu27Glu. In Pro12Ala/Gln27Glu, AGPI intake can result in greater body weight loss.