Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
1.
ACS Eng Au ; 3(3): 184-194, 2023 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-37362007

RESUMEN

A novel chemical looping (CL) process was demonstrated to produce acetaldehyde (AA) via oxidative dehydrogenation (ODH) of ethanol. Here, the ODH of ethanol takes place in the absence of a gaseous oxygen stream; instead, oxygen is supplied from a metal oxide, an active support for an ODH catalyst. The support material reduces as the reaction takes place and needs to be regenerated in air in a separate step, resulting in a CL process. Here, strontium ferrite perovskite (SrFeO3-δ) was used as the active support, with both silver and copper as the ODH catalysts. The performance of Ag/SrFeO3-δ and Cu/SrFeO3-δ was investigated in a packed bed reactor, operated at temperatures from 200 to 270 °C and a gas hourly space velocity of 9600 h-1. The CL capability to produce AA was then compared to the performance of bare SrFeO3-δ (no catalysts) and materials comprising a catalyst on an inert support, Cu or Ag on Al2O3. The Ag/Al2O3 catalyst was completely inactive in the absence of air, confirming that oxygen supplied from the support is required to oxidize ethanol to AA and water, while Cu/Al2O3 gradually got covered in coke, indicating cracking of ethanol. The bare SrFeO3-δ achieved a similar selectivity to AA as Ag/SrFeO3-δ but at a greatly reduced activity. For the best performing catalyst, Ag/SrFeO3-δ, the obtained selectivity to AA reached 92-98% at yields of up to 70%, comparable to the incumbent Veba-Chemie process for ethanol ODH, but at around 250 °C lower temperature. The CL-ODH setup was operated at high effective production times (i.e., the time spent producing AA to the time spent regenerating SrFeO3-δ). In the investigated configuration with 2 g of the CLC catalyst and 200 mL/min feed flowrate ∼5.8 vol % ethanol, only three reactors would be required for the pseudo-continuous production of AA via CL-ODH.

2.
Diagnostics (Basel) ; 12(3)2022 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-35328139

RESUMEN

BACKGROUND: A systemic inflammatory marker, the modified Glasgow prognostic score (mGPS), could predict outcomes in non-muscle-invasive bladder cancer (NIMBC). We aimed to investigate the predictive power of mGPS in oncological outcomes in HG/G3 T1 NMIBC patients undergoing Bacillus Calmette-Guérin (BCG) therapy. METHODS: We retrospectively reviewed patient's medical data from multicenter institutions. A total of 1382 patients with HG/G3 T1 NMIBC have been administered adjuvant intravesical BCG therapy, every week for 3 weeks given at 3, 6, 12, 18, 24, 30 and 36 months. The analysis of mGPS for recurrence and progression was performed using multivariable and univariable Cox regression models. RESULTS: During follow-up, 659 patients (47.68%) suffered recurrence, 441 (31.91%) suffered progression, 156 (11.28%) died of all causes, and 67 (4.84%) died of bladder cancer. At multivariable analysis, neutrophil to lymphocyte ratio [hazard ratio (HR): 7.471; p = 0.0001] and erythrocyte sedimentation rate (ESR) (HR: 0.706; p = 0.006 were significantly associated with recurrence. mGPS has no statistical significance for progression (p = 0.076). Kaplan-Meier survival analysis showed a significant difference in survival among patients from different mGPS subgroups. Five-year OS was 93% (CI 95% 92-94), in patients with mGPS 0, 82.2% (CI 95% 78.9-85.5) in patients with mGPS 1 and 78.1% (CI 95% 60.4-70) in mGPS 2 patients. Five-year CSS was 98% (CI 95% 97-99) in patients with mGPS 0, 90% (CI 95% 87-94) in patients with mGPS 1, and 100% in mGPS 2 patients. Limitations are applicable to a retrospective study. CONCLUSIONS: mGPS may have the potential to predict recurrence in HG/G3 T1 NMIBC patients, but more prospective, with large cohorts, studies are needed to study the influence of systemic inflammatory markers in prediction of outcomes in NMIBC for a definitive conclusion.

3.
J Vis Exp ; (176)2021 10 11.
Artículo en Inglés | MEDLINE | ID: mdl-34694296

RESUMEN

The fruit fly midgut consists of multiple regions, each of which is composed of cells that carry out unique physiological functions required for the proper functioning of the gut. One such region, the copper cell region (CCR), is localized to the middle midgut and consists, in part, of a group of cells known as copper cells. Copper cells are involved in gastric acid secretion, an evolutionarily conserved process whose precise role is poorly understood. This paper describes improvements in the current protocol used to assay for acidification of the adult Drosophila melanogaster gut and demonstrates that it can be used on other species of flies. In particular, this paper demonstrates that gut acidification is dependent on the fly's nutritional status and presents a protocol based on this new finding. Overall, this protocol demonstrates the potential usefulness of studying Drosophila copper cells to uncover general principles underlying the mechanisms of gut acidification.


Asunto(s)
Proteínas de Drosophila , Drosophila , Animales , Drosophila/fisiología , Proteínas de Drosophila/fisiología , Drosophila melanogaster/fisiología , Concentración de Iones de Hidrógeno , Intestinos
4.
Future Oncol ; 17(30): 3987-3994, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34278815

RESUMEN

The objective of the current research was to explore the potential prognostic value of readily available clinical and pathologic variables in bladder cancer. The novel association found between cholesterol levels and prognosis may provide the rationale for exploring novel treatments. Patients included had histologically confirmed urothelial bladder cancer and were treated with at least 3 cycles of cisplatin-based neoadjuvant chemotherapy before radical cystectomy with lymphadenectomy. A total of 245 patients at low, intermediate and high risk, presenting with 0-1, 2 or 3-4 risk factors, including positive lymph nodes, Hb <12.8, NLR ≥2.7 and cholesterol levels ≥199, were included. Five-year cancer-specific survival rate was 0.67, 0.78 and 0.94 at high, intermediate and low risk, respectively. Total cholesterol levels at the time of cystectomy may represent a commonly assessable prognostic factor and may be incorporated in a clinically meaningful risk-group classification model.


Lay abstract This present study assessed a large group of patients with urothelial bladder cancer treated with chemotherapy followed by radical cystectomy, to capture the predictive power of commonly collected clinical, pathological and biochemical factors. The design of the study highlighted that higher cholesterol levels at the time of cystectomy were associated with shorter cancer-specific survival. This finding suggests that high blood-cholesterol levels truly have a negative influence on surviving cancer. In conclusion, total cholesterol levels at the time of cystectomy may represent a commonly assessable prognostic factor and could be incorporated into a clinically meaningful and valuable risk-group classification model.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Anciano , Quimioterapia Adyuvante , Colesterol/sangre , Cisplatino/administración & dosificación , Cistectomía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Neoplasias de la Vejiga Urinaria/mortalidad
5.
Future Sci OA ; 7(7): FSO709, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34258022

RESUMEN

AIM: To investigate the prognostic role of neutrophil percentage-to-albumin ratio (NPAR) in muscle-invasive bladder cancer (MIBC) patients treated with neoadjuvant chemotherapy (NAC) and radical cystectomy (RC). PATIENTS & METHODS: 213 patients were included. INCLUSION CRITERIA: Nonmetastatic, MIBC (cT2-T4aN0M0), at least three cycles of NAC, undergone RC and with blood count within 30 days before NAC. RESULTS: Five-years overall survival (OS) with NPAR >18 was 34.06% (95% CI: 18.3-50.5) and 65.37% (95% CI: 52.4-75.6) with NPAR <18. Five years cancer-specific survival (CSS) with NPAR >18 was 42.9% (95% CI: 23.9-60.7) and 74.5% (95% CI: 62.6-83.1) with NPAR <18 (p < 0.001). In multivariable analysis, NPAR increased OS of 1.3 points and CSS of 4.37 points. CONCLUSION: High NPAR prior to NAC seems to be a strong predictor of OS and CSS in MIBC patients treated with NAC and RC.

6.
Transl Androl Urol ; 10(2): 626-635, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33718065

RESUMEN

BACKGROUND: An accurate and early diagnosis of bladder cancer (BC) is essential to offer patients the most appropriate treatment and the highest cure rate. For this reason, patients need to be best stratified by class and risk factors. We aimed to develop a score able to better predict cancer outcomes, using serum variables of inflammation. METHODS: A total of 1,510 high-risk non-muscle invasive bladder cancer (NMIBC) patients were included in this retrospective observational study. Patients with pathologically proven T1 HG/G3 at first TURBT were included. Systemic combined inflammatory score (SCIS) was calculated according to systemic inflammatory markers (SIM), modified Glasgow prognostic score (mGPS), and prognostic nutritional index (PNI) dichotomized (final score from 0 to 3). RESULTS: After 48 months of follow-up (IQR 40.0-73.0), 727 patients recurred (48.1%), 485 progressed (32.1%), 81 died for cancer (7.0%), and 163 died for overall causes (10.8%). Overall, 231 (15.3%) patients had concomitant Cis, 669 (44.3%) patients had multifocal pathology, 967 (64.1%) patients had tumor size >3 cm. Overall, 357 (23.6%) patients received immediate-intravesical therapy, 1,356 (89.8%) received adjuvant intravesical therapy, of which 1,382 (91.5%) received BCG, 266 (17.6%) patients received mitomycin C, 4 (0.5%) patients received others intravesical therapy. Higher SCIS was independently predictive of recurrence (hazard ratio HR 1.5, 1.3 and 2.2) and cancer specific mortality for SCIS 0 and 3 (HR: 1.61 and 2.3), and overall mortality for SCIS 0 and 3 (HR: 2.4 and 3.2). Conversely, SCIS was not associated with a higher probability of progression. CONCLUSIONS: The inclusion of the SCIS in clinical practice is simple to apply and can help improve the prediction of cancer outcomes. It can identify patients with high-grade BC who are more likely to experience disease mortality.

7.
Minerva Urol Nephrol ; 73(6): 796-802, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-33439571

RESUMEN

BACKGROUND: We aimed to test the hypothesis that the immune-modulatory effect of statins may improve survival outcomes in patients with non-muscle invasive bladder cancer (NMIBC). We focused on a cohort of patients diagnosed with high risk NMIBC, that were treated with intravesical BCG immunotherapy. METHODS: We included patients at first diagnosis of T1 high grade NMIBC after transurethral resection of bladder (TURB). All procedures were performed at 18 different tertiary institutions between January 2002 and December 2012. Univariable and multivariable models were used to test differences in terms of residual tumor, disease recurrence, disease progression and overall mortality (OM) rates. RESULTS: Overall, 1510 patients with T1 high grade NMIBC at TURB were included in our analyses. Of these, 402 (26.6%) were statin users. At multivariable analysis, statin use was associated with a higher rate of high-grade BC at re-TURB (OR: 1.37, 95%CI: 1.04-1.78; P=0.022), while at follow-up it was not independently associated with OM (HR: 0.71, 95%CI: 0.50-1.03; P=0.068) and disease progression rates (HR: 0.97, 95%CI: 0.79-1.19; P=0.753). Conversely, statin use has been shown to be independently associated with a lower risk of recurrence (HR:0.80, 95%CI: 0.67-0.95; P=0.009). The median recurrence-free survival was 47 (95%CI 40-49) months for those classified as non-statin users vs. 53 (95%CI 48-68) months in those classified as statin users. CONCLUSIONS: Statin daily intake do not compromise oncological outcomes in high risk NMIBC patients treated with BCG. Moreover, statin may have a beneficial effect on recurrence rates in this cohort of patients.


Asunto(s)
Carcinoma de Células Transicionales , Inhibidores de Hidroximetilglutaril-CoA Reductasas , Neoplasias de la Vejiga Urinaria , Carcinoma de Células Transicionales/tratamiento farmacológico , Progresión de la Enfermedad , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Recurrencia Local de Neoplasia , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico
8.
Urol Oncol ; 38(5): 459-464, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32173242

RESUMEN

OBJECTIVES: The aim of this multicenter study was to investigate the prognostic role of type 2 diabetes mellitus (T2DM) comorbidity in a large multi-institutional cohort of patients with primary T1HG/G3 non-muscle-invasive bladder cancer (NMIBC) treated with transurethral resection of the bladder (TURB). MATERIALS AND METHODS: A total of 1,172 patients with primary T1 HG/G3 who had NMIBC on re-TURB and who received adjuvant intravesical bacillus Calmette-Guérin therapy with maintenance were included. Endpoints were recurrence-free survival and progression-free survival. RESULTS: A total of 231 (19.7%) of patients had T2DM prior to TURB. Five-year recurrence-free survival estimates were 12.5% in patients with T2DM compared to 36% in patients without T2DM, P < 0.0001. Five-year PFS estimates were 60.5% in patients with T2DM compared to 70.2% in patients without T2DM, P = 0.003. T2DM was independently associated with disease recurrence (hazard ratio = 1.41; 95% confidence interval = 1.20-1.66, P < 0.001) and progression (hazard ratio = 1.27; 95% confidence interval = 0.99-1.63, P < 0.001), after adjusting for other known predictive factors such as tumor size, multifocality, T1G3 on re-TURB, body mass index, lymphovascular invasion, and neutrophil-to-lymphocytes ratio. CONCLUSIONS: Given the potential implications for management, prospective validation of this finding along with translational studies designed to investigate the underlying biology of such an association are warranted.


Asunto(s)
Adyuvantes Inmunológicos/uso terapéutico , Vacuna BCG/uso terapéutico , Cistectomía , Diabetes Mellitus Tipo 2/complicaciones , Neoplasias de la Vejiga Urinaria/complicaciones , Neoplasias de la Vejiga Urinaria/terapia , Anciano , Quimioterapia Adyuvante , Cistectomía/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Clasificación del Tumor , Invasividad Neoplásica , Estadificación de Neoplasias , Pronóstico , Supervivencia sin Progresión , Estudios Retrospectivos , Uretra , Neoplasias de la Vejiga Urinaria/patología
9.
Nature ; 574(7779): 559-564, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31645735

RESUMEN

Although glucose-sensing neurons were identified more than 50 years ago, the physiological role of glucose sensing in metazoans remains unclear. Here we identify a pair of glucose-sensing neurons with bifurcated axons in the brain of Drosophila. One axon branch projects to insulin-producing cells to trigger the release of Drosophila insulin-like peptide 2 (dilp2) and the other extends to adipokinetic hormone (AKH)-producing cells to inhibit secretion of AKH, the fly analogue of glucagon. These axonal branches undergo synaptic remodelling in response to changes in their internal energy status. Silencing of these glucose-sensing neurons largely disabled the response of insulin-producing cells to glucose and dilp2 secretion, disinhibited AKH secretion in corpora cardiaca and caused hyperglycaemia, a hallmark feature of diabetes mellitus. We propose that these glucose-sensing neurons maintain glucose homeostasis by promoting the secretion of dilp2 and suppressing the release of AKH when haemolymph glucose levels are high.


Asunto(s)
Encéfalo/metabolismo , Drosophila melanogaster/citología , Drosophila melanogaster/metabolismo , Glucagón/metabolismo , Glucosa/metabolismo , Insulina/metabolismo , Neuronas/metabolismo , Animales , Axones/metabolismo , Encéfalo/anatomía & histología , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/anatomía & histología , Glucosa/análisis , Hormonas de Insectos/metabolismo , Masculino , Inhibición Neural , Vías Nerviosas , Neuropéptidos/química , Neuropéptidos/metabolismo , Neurotransmisores/metabolismo , Oligopéptidos/metabolismo , Ácido Pirrolidona Carboxílico/análogos & derivados , Ácido Pirrolidona Carboxílico/metabolismo
10.
Clin Genitourin Cancer ; 16(6): 445-452, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30077463

RESUMEN

INTRODUCTION: The aim of this multicenter study was to investigate the prognostic role of neutrophil-to-lymphocyte ratio (NLR) and to validate the NLR cutoff of 3 in a large multi-institutional cohort of patients with primary T1 HG/G3 non-muscle-invasive bladder cancer (NMIBC). PATIENTS AND METHODS: The study period was from January 2002 through December 2012. A total of 1046 patients with primary T1 HG/G3 who had NMIBC on re-transurethral bladder resection (TURB) who received adjuvant intravesical bacillus Calmette-Guérin therapy with maintenance from 13 academic institutions were included. Endpoints were time to disease, and recurrence-free (RFS), progression-free (PFS), overall (OS), and cancer-specific survival (CSS). RESULTS: A total of 512 (48.9%) of patients had NLR ≥ 3 prior to TURB. High pretreatment NLR was associated with female gender and residual T1HG/G3 on re-TURB. The 5-year RFS estimates were 9.4% (95% confidence interval [CI], 6.8%-12.4%) in patients with NLR ≥ 3 compared with 58.8% (95% CI, 54%-63.2%) in patients with NLR < 3; the 5-year PFS estimates were 57.1% (95% CI, 51.5%-62.2%) versus 79.2% (95% CI, 74.7%-83%; P < .0001); the 10-year OS estimates were 63.6% (95% CI, 55%-71%) versus 66.5% (95% CI, 56.8%-74.5%; P = .03); the 10-year CSS estimates were 77.4% (95% CI, 68.4%-84.2%) versus 84.3% (95% CI, 76.6%-89.7%; P = .004). NLR was independently associated with disease recurrence (hazard ratio [HR], 3.34; 95% CI, 2.82-3.95; P < .001), progression (HR, 2.18; 95% CI, 1.71-2.78; P < .001) and CSS (HR, 1.65; 95% CI, 1.02-2.66; P = .03). The addition of NLR to a multivariable model that included established features increased its discrimination for predicting of RFS (+6.9%), PFS (+1.8%), and CSS (+1.7%). CONCLUSIONS: Pretreatment NLR ≥ 3 was a strong predictor for RFS, PFS, and CSS in patients with primary T1 HG/G3 NMIBC. It could help in the decision-making regarding intensity of therapy and follow-up.


Asunto(s)
Linfocitos , Recurrencia Local de Neoplasia/diagnóstico , Neutrófilos , Neoplasias de la Vejiga Urinaria/mortalidad , Administración Intravesical , Adulto , Anciano , Anciano de 80 o más Años , Vacuna BCG/uso terapéutico , Quimioterapia Adyuvante/métodos , Cistectomía , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Femenino , Humanos , Recuento de Linfocitos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/patología , Recurrencia Local de Neoplasia/prevención & control , Pronóstico , Estudios Retrospectivos , Neoplasias de la Vejiga Urinaria/sangre , Neoplasias de la Vejiga Urinaria/patología , Neoplasias de la Vejiga Urinaria/terapia
11.
Urol Int ; 101(1): 7-15, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29975950

RESUMEN

INTRODUCTION: The aim of this multicenter study was to investigate the prognostic impact of residual T1 high-grade (HG)/G3 tumors at re-transurethral resection (TUR of bladder tumor) in a large multi-institutional cohort of patients with primary T1 HG/G3 bladder cancer (BC). PATIENTS AND METHODS: The study period was from January 2002 to -December 2012. A total of 1,046 patients with primary T1 HG/G3 and who had non-muscle invasive BC (NMIBC) on re-TUR followed by adjuvant intravesical Bacillus Calmette-Guerin (BCG) therapy with maintenance were included. Endpoints were time to disease recurrence, progression, and overall and cancer-specific death. RESULTS: A total of 257 (24.6%) patients had residual T1 HG/G3 tumors. The presence of concomitant carcinoma in situ, multiple and large tumors (> 3 cm) at first TUR were associated with residual T1 HG/G3. Five-year recurrence-free survival (RFS), progression-free survival (PFS), overall survival (OS), and cancer-specific survival (CSS) were 17% (CI 11.8-23); 58.2% (CI 50.7-65); 73.7% (CI 66.3-79.7); and 84.5% (CI 77.8-89.3), respectively, in patients with residual T1 HG/G3, compared to 36.7% (CI 32.8-40.6); 71.4% (CI 67.3-75.2); 89.8% (CI 86.6-92.3); and 95.7% (CI 93.4-97.3), respectively, in patients with NMIBC other than T1 HG/G3 or T0 tumors. Residual T1 HG/G3 was independently associated with RFS, PFS, OS, and CSS in multivariable analyses. CONCLUSIONS: Residual T1 HG/G3 tumor at re-TUR confers worse prognosis in patients with primary T1 HG/G3 treated with maintenance BCG. Patients with residual T1 HG/G3 for primary T1 HG/G3 are very likely to fail BCG therapy alone.


Asunto(s)
Carcinoma de Células Transicionales/patología , Recurrencia Local de Neoplasia/patología , Neoplasias de la Vejiga Urinaria/cirugía , Procedimientos Quirúrgicos Urológicos/métodos , Anciano , Anciano de 80 o más Años , Cistectomía/métodos , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Supervivencia sin Progresión , Recurrencia , Análisis de Regresión , Factores de Tiempo , Resultado del Tratamiento , Neoplasias de la Vejiga Urinaria/patología
12.
Proc Natl Acad Sci U S A ; 115(12): E2829-E2838, 2018 03 20.
Artículo en Inglés | MEDLINE | ID: mdl-29507251

RESUMEN

Sweet-insensitive Drosophila mutants are unable to readily identify sugar. In presence of wild-type (WT) flies, however, these mutant flies demonstrated a marked increase in their preference for nutritive sugar. Real-time recordings of starved WT flies revealed that these flies discharge a drop from their gut end after consuming nutritive sugars, but not nonnutritive sugars. We proposed that the drop may contain a molecule(s) named calorie-induced secreted factor (CIF), which serves as a signal to inform other flies about its nutritional value. Consistent with this, we observed a robust preference of flies for nutritive sugar containing CIF over nutritive sugar without CIF. Feeding appears to be a prerequisite for the release of CIF, given that fed flies did not produce it. Additionally, correlation analyses and pharmacological approaches suggest that the nutritional value, rather than the taste, of the consumed sugar correlates strongly with the amount (or intensity) of the released CIF. We observed that the release of this attractant signal requires the consumption of macronutrients, specifically nutritive sugars and l-enantiomer essential amino acids (l-eAAs), but it is negligibly released when flies are fed nonnutritive sugars, unnatural d-enantiomer essential amino acids (d-eAAs), fatty acids, alcohol, or salts. Finally, CIF (i) is not detected by the olfactory system, (ii) is not influenced by the sex of the fly, and (iii) is not limited to one species of Drosophila.


Asunto(s)
Drosophila/fisiología , Feromonas/metabolismo , Azúcares , Comunicación Animal , Animales , Drosophila/genética , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Femenino , Masculino , Mutación , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Valor Nutritivo , Bulbo Olfatorio/fisiología , Factores de Transcripción Paired Box/genética , Factores de Transcripción Paired Box/metabolismo , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismo , Especificidad de la Especie , Azúcares/metabolismo , Azúcares/farmacología
14.
Curr Biol ; 26(15): 1965-1974, 2016 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-27397890

RESUMEN

Hunger is a powerful drive that stimulates food intake. Yet, the mechanism that determines how the energy deficits that result in hunger are represented in the brain and promote feeding is not well understood. We previously described SLC5A11-a sodium/solute co-transporter-like-(or cupcake) in Drosophila melanogaster, which is required for the fly to select a nutritive sugar over a sweeter nonnutritive sugar after periods of food deprivation. SLC5A11 acts on approximately 12 pairs of ellipsoid body (EB) R4 neurons to trigger the selection of nutritive sugars, but the underlying mechanism is not understood. Here, we report that the excitability of SLC5A11-expressing EB R4 neurons increases dramatically during starvation and that this increase is abolished in the SLC5A11 mutation. Artificial activation of SLC5A11-expresssing neurons is sufficient to promote feeding and hunger-driven behaviors; silencing these neurons has the opposite effect. Notably, SLC5A11 transcript levels in the brain increase significantly when flies are starved and decrease shortly after starved flies are refed. Furthermore, expression of SLC5A11 is sufficient for promoting hunger-driven behaviors and enhancing the excitability of SLC5A11-expressing neurons. SLC5A11 inhibits the function of the Drosophila KCNQ potassium channel in a heterologous expression system. Accordingly, a knockdown of dKCNQ expression in SLC5A11-expressing neurons produces hunger-driven behaviors even in fed flies, mimicking the overexpression of SLC5A11. We propose that starvation increases SLC5A11 expression, which enhances the excitability of SLC5A11-expressing neurons by suppressing dKCNQ channels, thereby conferring the hunger state.


Asunto(s)
Proteínas de Drosophila/genética , Drosophila melanogaster/fisiología , Privación de Alimentos , Hambre , Canales de Potasio/genética , Proteínas de Transporte de Sodio-Glucosa/genética , Animales , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Masculino , Neuronas/metabolismo , Canales de Potasio/metabolismo , Proteínas de Transporte de Sodio-Glucosa/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA