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1.
Stroke ; 55(2): 288-295, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38174568

RESUMEN

BACKGROUND: Understanding sex differences in stroke care is important in reducing potential disparities. Our objective was to explore sex differences in workflow efficiency, treatment efficacy, and safety in the AcT trial (Alteplase Compared to Tenecteplase). METHODS: AcT was a multicenter, registry-linked randomized noninferiority trial comparing tenecteplase (0.25 mg/kg) with alteplase (0.9 mg/kg) in acute ischemic stroke within 4.5 hours of onset. In this post hoc analysis, baseline characteristics, workflow times, successful reperfusion (extended Thrombolysis in Cerebral Infarction score ≥2b), symptomatic intracerebral hemorrhage, 90-day functional independence (modified Rankin Scale score, 0-1), and 90-day mortality were compared by sex. Mixed-effects regression analysis was used adjusting for age, stroke severity, and occlusion site for outcomes. RESULTS: Of 1577 patients treated with intravenous thrombolysis (2019-2022), 755 (47.9%) were women. Women were older (median, 77 [68-86] years in women versus 70 [59-79] years in men) and had a higher proportion of severe strokes (National Institutes of Health Stroke Scale score >15; 32.4% versus 24.9%) and large vessel occlusions (28.7% versus 21.5%) compared with men. All workflow times were comparable between sexes. Women were less likely to achieve functional independence (31.7% versus 39.8%; unadjusted relative risk, 0.80 [95% CI, 0.70-0.91]) and had higher mortality (17.7% versus 13.3%; unadjusted relative risk, 1.33 [95% CI, 1.06-1.69]). Adjusted analysis showed no difference in outcomes between sexes. CONCLUSIONS: Differences in prognostic factors of age, stroke severity, and occlusion site largely accounted for higher functional dependence and mortality in women. No sex disparities were apparent in workflow quality indicators. Given the integration of the AcT trial into clinical practice, these results provide reassurance that no major sex biases are apparent in acute stroke management throughout participating Canadian centers. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03889249.


Asunto(s)
Accidente Cerebrovascular Isquémico , Tenecteplasa , Activador de Tejido Plasminógeno , Femenino , Humanos , Masculino , Canadá , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Tenecteplasa/efectos adversos , Activador de Tejido Plasminógeno/efectos adversos , Resultado del Tratamiento , Flujo de Trabajo , Estudios Multicéntricos como Asunto , Ensayos Clínicos Controlados Aleatorios como Asunto , Estudios de Equivalencia como Asunto
2.
Stroke ; 55(3): 524-531, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38275116

RESUMEN

BACKGROUND: Recent evidence from thrombolysis trials indicates the noninferiority of intravenous tenecteplase to intravenous alteplase with respect to good functional outcomes in patients with acute stroke. We examined whether the health-related quality of life (HRQOL) of patients with acute stroke differs by the type of thrombolysis treatment received. In addition, we examined the association between the modified Rankin Scale score 0 to 1 and HRQOL and patient-reported return to prebaseline stroke functioning at 90 days. METHODS: Data were from all patients included in the AcT trial (Alteplase Compared to Tenecteplase), a pragmatic, registry-linked randomized trial comparing tenecteplase with alteplase. HRQOL at 90-day post-randomization was assessed using the 5-item EuroQOL questionnaire (EQ5D), which consists of 5 items and a visual analog scale (VAS). EQ5D index values were estimated from the EQ5D items using the time tradeoff approach based on Canadian norms. Tobit regression and quantile regression models were used to evaluate the adjusted effect of tenecteplase versus alteplase treatment on the EQ5D index values and VAS score, respectively. The association between return to prebaseline stroke functioning and the modified Rankin Scale score 0 to 1 and HRQOL was quantified using correlation coefficient (r) with 95% CI. RESULTS: Of 1577 included in the intention-to-treat analysis patients, 1503 (95.3%) had complete data on the EQ5D. Of this, 769 (51.2%) were administered tenecteplase and 717 (47.7%) were female. The mean EQ5D VAS score and EQ5D index values were not significantly higher for those who received intravenous tenecteplase compared with those who received intravenous alteplase (P=0.10). Older age (P<0.01), more severe stroke assessed using the National Institutes of Health Stroke Scale (P<0.01), and longer stroke onset-to-needle time (P=0.004) were associated with lower EQ5D index and VAS scores. There was a strong association (r, 0.85 [95% CI, 0.81-0.89]) between patient-reported return to prebaseline functioning and modified Rankin Scale score 0 to 1 Similarly, there was a moderate association between return to prebaseline functioning and EQ5D index (r, 0.45 [95% CI, 0.40-0.49]) and EQ5D VAS scores (r, 0.42 [95% CI, 0.37-0.46]). CONCLUSIONS: Although there is no differential effect of thrombolysis type on patient-reported global HRQOL and EQ 5D-5L index values in patients with acute stroke, sex- and age-related differences in HRQOL were noted in this study. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03889249.


Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Humanos , Femenino , Masculino , Activador de Tejido Plasminógeno , Tenecteplasa/efectos adversos , Fibrinolíticos , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Calidad de Vida , Isquemia Encefálica/tratamiento farmacológico , Isquemia Encefálica/inducido químicamente , Canadá , Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/inducido químicamente , Terapia Trombolítica , Resultado del Tratamiento
3.
J Lipid Res ; 64(2): 100324, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36586437

RESUMEN

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease with increased risk in patients with metabolic syndrome. There are no FDA-approved treatments, but FXR agonists have shown promising results in clinical studies for NAFLD management. In addition to FXR, fibroblast growth factor receptor FGFR4 is a key mediator of hepatic bile acid synthesis. Using N-acetylgalactosamine-conjugated siRNA, we knocked down FGFR4 specifically in the liver of mice on chow or high-fat diet and in mouse primary hepatocytes to determine the role of FGFR4 in metabolic processes and hepatic steatosis. Liver-specific FGFR4 silencing increased bile acid production and lowered serum cholesterol. Additionally, we found that high-fat diet-induced liver steatosis and insulin resistance improved following FGFR4 knockdown. These improvements were associated with activation of the FXR-FGF15 axis in intestinal cells, but not in hepatocytes. We conclude that targeting FGFR4 in the liver to activate the intestinal FXR-FGF15 axis may be a promising strategy for the treatment of NAFLD and metabolic dysfunction.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Animales , Ratones , Ácidos y Sales Biliares/metabolismo , Factores de Crecimiento de Fibroblastos/metabolismo , Hepatocitos/metabolismo , Hígado/metabolismo , Ratones Endogámicos C57BL , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Receptores Citoplasmáticos y Nucleares/metabolismo
4.
Stroke ; 54(11): 2766-2775, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37800372

RESUMEN

BACKGROUND: The AcT (Alteplase Compared to Tenecteplase) randomized controlled trial showed that tenecteplase is noninferior to alteplase in treating patients with acute ischemic stroke within 4.5 hours of symptom onset. The effect of time to treatment on clinical outcomes with alteplase is well known; however, the nature of this relationship is yet to be described with tenecteplase. We assessed whether the association of time to thrombolysis treatment with clinical outcomes in patients with acute ischemic stroke differs by whether they receive intravenous tenecteplase versus alteplase. METHODS: Patients included were from AcT, a pragmatic, registry-linked, phase 3 randomized controlled trial comparing intravenous tenecteplase to alteplase in patients with acute ischemic stroke. Eligible patients were >18 years old, with disabling neurological deficits, presenting within 4.5 hours of symptom onset, and eligible for thrombolysis. Primary outcome was modified Rankin Scale score 0 to 1 at 90 days. Safety outcomes included 24-hour symptomatic intracerebral hemorrhage and 90-day mortality rates. Mixed-effects logistic regression was used to assess the following: (a) the association of stroke symptom onset to needle time; (b) door (hospital arrival) to needle time with outcomes; and (c) if these associations were modified by type of thrombolytic administered (tenecteplase versus alteplase), after adjusting for age, sex, baseline stroke severity, and site of intracranial occlusion. RESULTS: Of the 1538 patients included in this analysis, 1146 (74.5%; 591 tenecteplase and 555 alteplase) presented within 3 hours versus 392 (25.5%; 196: TNK and 196 alteplase) who presented within 3 to 4.5 hours of symptom onset. Baseline patient characteristics in the 0 to 3 hours versus 3- to 4.5-hour time window were similar, except patients in the 3- to 4.5-hour window had lower median baseline National Institutes of Health Stroke Severity Scale (10 versus 7, respectively) and lower proportion of patients with large vessel occlusion on baseline CT angiography (26.9% versus 18.7%, respectively). Type of thrombolytic agent (tenecteplase versus alteplase) did not modify the association between continuous onset to needle time (Pinteraction=0.161) or door-to-needle time (Pinteraction=0.972) and primary clinical outcome. Irrespective of the thrombolytic agent used, each 30-minute reduction in onset to needle time was associated with a 1.8% increase while every 10 minutes reduction in door-to-needle time was associated with a 0.2% increase in the probability of achieving 90-day modified Rankin Scale score 0 to 1, respectively. CONCLUSIONS: The effect of time to tenecteplase administration on clinical outcomes is like that of alteplase, with faster administration resulting in better clinical outcomes. REGISTRATION: URL: https://classic. CLINICALTRIALS: gov; Unique identifier: NCT03889249.


Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Adolescente , Humanos , Isquemia Encefálica/tratamiento farmacológico , Isquemia Encefálica/inducido químicamente , Fibrinolíticos , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Tenecteplasa/efectos adversos , Terapia Trombolítica/métodos , Activador de Tejido Plasminógeno , Resultado del Tratamiento
5.
Antimicrob Agents Chemother ; 67(7): e0046223, 2023 07 18.
Artículo en Inglés | MEDLINE | ID: mdl-37310224

RESUMEN

HIV-1 integrase-LEDGF allosteric inhibitors (INLAIs) share the binding site on the viral protein with the host factor LEDGF/p75. These small molecules act as molecular glues promoting hyper-multimerization of HIV-1 IN protein to severely perturb maturation of viral particles. Herein, we describe a new series of INLAIs based on a benzene scaffold that display antiviral activity in the single digit nanomolar range. Akin to other compounds of this class, the INLAIs predominantly inhibit the late stages of HIV-1 replication. A series of high-resolution crystal structures revealed how these small molecules engage the catalytic core and the C-terminal domains of HIV-1 IN. No antagonism was observed between our lead INLAI compound BDM-2 and a panel of 16 clinical antiretrovirals. Moreover, we show that compounds retained high antiviral activity against HIV-1 variants resistant to IN strand transfer inhibitors and other classes of antiretroviral drugs. The virologic profile of BDM-2 and the recently completed single ascending dose phase I trial (ClinicalTrials.gov identifier: NCT03634085) warrant further clinical investigation for use in combination with other antiretroviral drugs. Moreover, our results suggest routes for further improvement of this emerging drug class.


Asunto(s)
Infecciones por VIH , Inhibidores de Integrasa VIH , Integrasa de VIH , Humanos , Replicación Viral , Inhibidores de Integrasa VIH/farmacología , Inhibidores de Integrasa VIH/uso terapéutico , Antivirales/farmacología , Integrasa de VIH/metabolismo , Infecciones por VIH/tratamiento farmacológico , Regulación Alostérica
6.
Lancet ; 400(10347): 161-169, 2022 07 16.
Artículo en Inglés | MEDLINE | ID: mdl-35779553

RESUMEN

BACKGROUND: Intravenous thrombolysis with alteplase bolus followed by infusion is a global standard of care for patients with acute ischaemic stroke. We aimed to determine whether tenecteplase given as a single bolus might increase reperfusion compared with this standard of care. METHODS: In this multicentre, open-label, parallel-group, registry-linked, randomised, controlled trial (AcT), patients were enrolled from 22 primary and comprehensive stroke centres across Canada. Patients were eligible for inclusion if they were aged 18 years or older, with a diagnosis of ischaemic stroke causing disabling neurological deficit, presenting within 4·5 h of symptom onset, and eligible for thrombolysis per Canadian guidelines. Eligible patients were randomly assigned (1:1), using a previously validated minimal sufficient balance algorithm to balance allocation by site and a secure real-time web-based server, to either intravenous tenecteplase (0·25 mg/kg to a maximum of 25 mg) or alteplase (0·9 mg/kg to a maximum of 90mg; 0·09 mg/kg as a bolus and then a 60 min infusion of the remaining 0·81 mg/kg). The primary outcome was the proportion of patients who had a modified Rankin Scale (mRS) score of 0-1 at 90-120 days after treatment, assessed via blinded review in the intention-to-treat (ITT) population (ie, all patients randomly assigned to treatment who did not withdraw consent). Non-inferiority was met if the lower 95% CI of the difference in the proportion of patients who met the primary outcome between the tenecteplase and alteplase groups was more than -5%. Safety was assessed in all patients who received any of either thrombolytic agent and who were reported as treated. The trial is registered with ClinicalTrials.gov, NCT03889249, and is closed to accrual. FINDINGS: Between Dec 10, 2019, and Jan 25, 2022, 1600 patients were enrolled and randomly assigned to tenecteplase (n=816) or alteplase (n=784), of whom 1577 were included in the ITT population (n=806 tenecteplase; n=771 alteplase). The median age was 74 years (IQR 63-83), 755 (47·9%) of 1577 patients were female and 822 (52·1%) were male. As of data cutoff (Jan 21, 2022), 296 (36·9%) of 802 patients in the tenecteplase group and 266 (34·8%) of 765 in the alteplase group had an mRS score of 0-1 at 90-120 days (unadjusted risk difference 2·1% [95% CI - 2·6 to 6·9], meeting the prespecified non-inferiority threshold). In safety analyses, 27 (3·4%) of 800 patients in the tenecteplase group and 24 (3·2%) of 763 in the alteplase group had 24 h symptomatic intracerebral haemorrhage and 122 (15·3%) of 796 and 117 (15·4%) of 763 died within 90 days of starting treatment INTERPRETATION: Intravenous tenecteplase (0·25 mg/kg) is a reasonable alternative to alteplase for all patients presenting with acute ischaemic stroke who meet standard criteria for thrombolysis. FUNDING: Canadian Institutes of Health Research, Alberta Strategy for Patient Oriented Research Support Unit.


Asunto(s)
Isquemia Encefálica , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Anciano , Isquemia Encefálica/complicaciones , Isquemia Encefálica/tratamiento farmacológico , Canadá , Femenino , Fibrinolíticos/uso terapéutico , Humanos , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Masculino , Sistema de Registros , Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/etiología , Tenecteplasa , Activador de Tejido Plasminógeno/uso terapéutico , Resultado del Tratamiento
7.
J Lipid Res ; 62: 100096, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34280453

RESUMEN

Proprotein convertase subtilisin/kexin type 9 (PCSK9) promotes lysosomal degradation of the LDL receptor and is a key regulator of cholesterol metabolism. After the liver, the small intestine is the second organ that highly expresses PCSK9. However, the small intestine's ability to secrete PCSK9 remains a matter of debate. While liver-specific PCSK9-deficient mice present no PCSK9 in systemic blood, human intestinal Caco-2 cells can actively secrete PCSK9. This raises the possibility for active intestinal secretion via the portal blood. Here, we aimed to determine whether enterocytes can secrete PCSK9 using in vitro, ex vivo, and in vivo approaches. We first observed that PCSK9 secretion from Caco-2 cells was biphasic and dependent on Caco-2 maturation status. Transcriptional analysis suggested that this transient reduction in PCSK9 secretion might be due to loss of SREBP2-mediated transcription of PCSK9. Consistently, PCSK9 secretion was not detected ex vivo in human or mouse intestinal biopsies mounted in Ussing chambers. Finally, direct comparison of systemic versus portal blood PCSK9 concentrations in WT or liver-specific PCSK9-deficient mice confirmed the inability of the small intestine to secrete PCSK9 into the portal compartment. Altogether, our data demonstrate that mature enterocytes do not secrete PCSK9 and reinforce the central role of the liver in the regulation of the concentration of circulating PCSK9 and consequently of cellular LDL receptors.


Asunto(s)
Proproteína Convertasa 9/metabolismo , Animales , Células CACO-2 , Diferenciación Celular , Células Cultivadas , Humanos , Intestino Delgado/citología , Intestino Delgado/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Proproteína Convertasa 9/sangre , Proproteína Convertasa 9/deficiencia
8.
Arterioscler Thromb Vasc Biol ; 40(9): 2084-2094, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32673528

RESUMEN

OBJECTIVE: Increased postprandial lipemia (PPL) is an independent risk factor for atherosclerotic cardiovascular diseases. PCSK9 (Proprotein convertase subtilisin kexin type 9) is an endogenous inhibitor of the LDLR (low-density lipoprotein receptor) pathway. We previously showed that PCSK9 inhibition in mice reduces PPL. However, the relative contribution of intracellular intestinal PCSK9 or liver-derived circulating PCSK9 to this effect is still unclear. Approach and Results: To address this issue, we generated the first intestine-specific Pcsk9-deficient (i-Pcsk9-/-) mouse model. PPL was measured in i-Pcsk9-/- as well as in wild-type and streptozotocin-induced diabetic mice following treatment with a PCSK9 monoclonal antibody (alirocumab). Blocking the circulating form of PCSK9 with alirocumab significantly reduced PPL, while overexpressing human PCSK9 in the liver of full Pcsk9-/- mice had the opposite effect. Alirocumab regulated PPL in a LDLR-dependent manner as this effect was abolished in Ldlr-/- mice. In contrast, i-Pcsk9-/- mice did not exhibit alterations in plasma lipid parameters nor in PPL. Finally, PPL was highly exacerbated by streptozotocin-induced diabetes mellitus in Pcsk9+/+ but not in Pcsk9-/- mice, an effect that was mimicked by the use of alirocumab in streptozotocin-treated Pcsk9+/+ mice. CONCLUSIONS: Taken together, our data demonstrate that PPL is significantly altered by full but not intestinal PCSK9 deficiency. Treatment with a PCSK9 monoclonal antibody mimics the effect of PCSK9 deficiency on PPL suggesting that circulating PCSK9 rather than intestinal PCSK9 is a critical regulator of PPL. These data validate the clinical relevance of PCSK9 inhibitors to reduce PPL, especially in patients with type 2 diabetes mellitus.


Asunto(s)
Diabetes Mellitus Experimental/sangre , Diabetes Mellitus Tipo 2/sangre , Hiperlipidemias/sangre , Intestinos/enzimología , Lípidos/sangre , Proproteína Convertasa 9/sangre , Animales , Anticuerpos Monoclonales Humanizados/farmacología , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/enzimología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/enzimología , Hiperlipidemias/enzimología , Hiperlipidemias/genética , Hiperlipidemias/prevención & control , Hipolipemiantes/farmacología , Intestinos/efectos de los fármacos , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Inhibidores de PCSK9 , Periodo Posprandial , Proproteína Convertasa 9/deficiencia , Proproteína Convertasa 9/genética , Receptores de LDL/genética , Receptores de LDL/metabolismo
9.
Blood ; 132(11): 1193-1197, 2018 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-30064978

RESUMEN

Von Willebrand factor (VWF) modulates factor VIII (FVIII) clearance and the anti-FVIII immune response. Despite the high affinity that defines the FVIII/VWF interaction, association/dissociation kinetics dictates 2% to 5% FVIII being present as free protein. To avoid free FVIII when studying the FVIII-VWF complex in vivo, we designed a FVIII-nanobody fusion protein, with the nanobody part being directed against VWF. This fusion protein, designated FVIII-KB013bv, had a 25-fold higher affinity compared with B-domainless FVIII (BDD-FVIII) for VWF. In vitro analysis revealed full cofactor activity in 1-stage clotting and chromogenic assays (activity/antigen ratio 1.0 ± 0.3 and 1.1 ± 0.3, respectively). In vivo, FVIII-013bv displayed a twofold increased mean residence time compared with BDD-FVIII (3.0 hours vs 1.6 hours). In a tail clip-bleeding assay performed 24 hours after FVIII infusion, blood loss was significantly reduced in mice receiving FVIII-KB013bv vs BDD-FVIII (15 ± 7 µL vs 194 ± 146 µL; P = .0043). Unexpectedly, when examining anti-FVIII antibody formation in FVIII-deficient mice, the immune-response toward FVIII-KB013bv was significantly reduced compared with BDD-FVIII (1/8 vs 14/16 mice produced anti-FVIII antibodies after treatment with FVIII-KB013bv and BDD-FVIII, respectively). Our data show that a stabilized interaction between FVIII and VWF is associated with a prolonged survival of FVIII and a reduced immune response against FVIII.


Asunto(s)
Formación de Anticuerpos/efectos de los fármacos , Autoanticuerpos , Factor VIII , Proteínas Recombinantes de Fusión , Anticuerpos de Dominio Único/farmacología , Factor de von Willebrand , Animales , Autoanticuerpos/inmunología , Autoanticuerpos/metabolismo , Factor VIII/inmunología , Factor VIII/farmacocinética , Factor VIII/farmacología , Ratones , Ratones Mutantes , Proteínas Recombinantes de Fusión/inmunología , Proteínas Recombinantes de Fusión/farmacocinética , Proteínas Recombinantes de Fusión/farmacología , Factor de von Willebrand/inmunología , Factor de von Willebrand/metabolismo
10.
Curr Diab Rep ; 20(11): 64, 2020 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-33057854

RESUMEN

PURPOSE OF REVIEW: The objective of this review is to provide up-to-date and comprehensive discussion of tissue-specific fructose metabolism in the context of diabetes, dyslipidemia, and nonalcoholic fatty liver disease (NAFLD). RECENT FINDINGS: Increased intake of dietary fructose is a risk factor for a myriad of metabolic complications. Tissue-specific fructose metabolism has not been well delineated in terms of its contribution to detrimental health effects associated with fructose intake. Since inhibitors targeting fructose metabolism are being developed for the management of NAFLD and diabetes, it is essential to recognize how inability of one tissue to metabolize fructose may affect metabolism in the other tissues. The primary sites of fructose metabolism are the liver, intestine, and kidney. Skeletal muscle and adipose tissue can also metabolize a large portion of fructose load, especially in the setting of ketohexokinase deficiency, the rate-limiting enzyme of fructose metabolism. Fructose can also be sensed by the pancreas and the brain, where it can influence essential functions involved in energy homeostasis. Lastly, fructose is metabolized by the testes, red blood cells, and lens of the eye where it may contribute to infertility, advanced glycation end products, and cataracts, respectively. An increase in sugar intake, particularly fructose, has been associated with the development of obesity and its complications. Inhibition of fructose utilization in tissues primary responsible for its metabolism alters consumption in other tissues, which have not been traditionally regarded as important depots of fructose metabolism.


Asunto(s)
Diabetes Mellitus , Enfermedad del Hígado Graso no Alcohólico , Fructosa/efectos adversos , Humanos , Hígado , Enfermedad del Hígado Graso no Alcohólico/etiología , Obesidad/etiología
11.
J Biol Chem ; 293(16): 6172-6186, 2018 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-29507092

RESUMEN

Recently, a new class of HIV-1 integrase (IN) inhibitors with a dual mode of action, called IN-LEDGF/p75 allosteric inhibitors (INLAIs), was described. Designed to interfere with the IN-LEDGF/p75 interaction during viral integration, unexpectedly, their major impact was on virus maturation. This activity has been linked to induction of aberrant IN multimerization, whereas inhibition of the IN-LEDGF/p75 interaction accounts for weaker antiretroviral effect at integration. Because these dual activities result from INLAI binding to IN at a single binding site, we expected that these activities co-evolved together, driven by the affinity for IN. Using an original INLAI, MUT-A, and its activity on an Ala-125 (A125) IN variant, we found that these two activities on A125-IN can be fully dissociated: MUT-A-induced IN multimerization and the formation of eccentric condensates in viral particles, which are responsible for inhibition of virus maturation, were lost, whereas inhibition of the IN-LEDGF/p75 interaction and consequently integration was fully retained. Hence, the mere binding of INLAI to A125 IN is insufficient to promote the conformational changes of IN required for aberrant multimerization. By analyzing the X-ray structures of MUT-A bound to the IN catalytic core domain (CCD) with or without the Ala-125 polymorphism, we discovered that the loss of IN multimerization is due to stabilization of the A125-IN variant CCD dimer, highlighting the importance of the CCD dimerization energy for IN multimerization. Our study reveals that affinity for the LEDGF/p75-binding pocket is not sufficient to induce INLAI-dependent IN multimerization and the associated inhibition of viral maturation.


Asunto(s)
Inhibidores de Integrasa VIH/farmacología , Integrasa de VIH/efectos de los fármacos , VIH-1/fisiología , Ensamble de Virus/efectos de los fármacos , Integración Viral/efectos de los fármacos , Regulación Alostérica , Sitios de Unión , Línea Celular , Inhibidores de Integrasa VIH/química , Humanos , Estructura Molecular , Piridinas/química , Piridinas/farmacología , Relación Estructura-Actividad , Tiofenos/química , Tiofenos/farmacología
14.
Retrovirology ; 14(1): 50, 2017 11 09.
Artículo en Inglés | MEDLINE | ID: mdl-29121950

RESUMEN

BACKGROUND: HIV-1 Integrase (IN) interacts with the cellular co-factor LEDGF/p75 and tethers the HIV preintegration complex to the host genome enabling integration. Recently a new class of IN inhibitors was described, the IN-LEDGF allosteric inhibitors (INLAIs). Designed to interfere with the IN-LEDGF interaction during integration, the major impact of these inhibitors was surprisingly found on virus maturation, causing a reverse transcription defect in target cells. RESULTS: Here we describe the MUT-A compound as a genuine INLAI with an original chemical structure based on a new type of scaffold, a thiophene ring. MUT-A has all characteristics of INLAI compounds such as inhibition of IN-LEDGF/p75 interaction, IN multimerization, dual antiretroviral (ARV) activities, normal packaging of genomic viral RNA and complete Gag protein maturation. MUT-A has more potent ARV activity compared to other INLAIs previously reported, but similar profile of resistance mutations and absence of ARV activity on SIV. HIV-1 virions produced in the presence of MUT-A were non-infectious with the formation of eccentric condensates outside of the core. In studying the immunoreactivity of these non-infectious virions, we found that inactivated HIV-1 particles were captured by anti-HIV-specific neutralizing and non-neutralizing antibodies (b12, 2G12, PGT121, 4D4, 10-1074, 10E8, VRC01) with efficiencies comparable to non-treated virus. Autologous CD4+ T lymphocyte proliferation and cytokine induction by monocyte-derived dendritic cells (MDDC) pulsed either with MUT-A-inactivated HIV or non-treated HIV were also comparable. CONCLUSIONS: Although strongly defective in infectivity, HIV-1 virions produced in the presence of the MUT-A INLAI have a normal protein and genomic RNA content as well as B and T cell immunoreactivities comparable to non-treated HIV-1. These inactivated viruses might form an attractive new approach in vaccine research in an attempt to study if this new type of immunogen could elicit an immune response against HIV-1 in animal models.


Asunto(s)
Inhibidores de Integrasa VIH/farmacología , Integrasa de VIH/metabolismo , VIH-1/efectos de los fármacos , VIH-1/enzimología , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Piridinas/farmacología , Tiofenos/farmacología , Línea Celular , Anticuerpos Anti-VIH/inmunología , Inhibidores de Integrasa VIH/química , VIH-1/inmunología , Humanos , Piridinas/química , Tiofenos/química , Ensamble de Virus/efectos de los fármacos , Integración Viral/efectos de los fármacos , Replicación Viral/efectos de los fármacos
15.
Eur J Nucl Med Mol Imaging ; 42(3): 409-18, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25367749

RESUMEN

PURPOSE: (18)F-FDOPA PET imaging is increasingly used in the work-up of patients with neuroendocrine tumours. It has been shown to be of limited value in localizing pancreatic insulin-secreting tumours in adults with hyperinsulinaemic hypoglycaemia (HH) mainly due to (18)F-FDOPA uptake by the whole pancreatic gland. The objective of this study was to review our experience with (18)F-FDOPA PET/CT imaging with carbidopa (CD) premedication in patients with HH in comparison with PET/CT studies performed without CD premedication in an independent population. METHODS: A retrospective study including 16 HH patients who were investigated between January 2011 and December 2013 using (18)F-FDOPA PET/CT (17 examinations) in two academic endocrine tumour centres was conducted. All PET/CT examinations were performed under CD premedication (200 mg orally, 1 - 2 h prior to tracer injection). The PET/CT acquisition protocol included an early acquisition (5 min after (18)F-FDOPA injection) centred over the upper abdomen and a delayed whole-body acquisition starting 20 - 30 min later. An independent series of eight consecutive patients with HH and investigated before 2011 were considered for comparison. All patients had a reference whole-body PET/CT scan performed about 1 h after (18)F-FDOPA injection. In all cases, PET/CT was performed without CD premedication. RESULTS: In the study group, (18)F-FDOPA PET/CT with CD premedication was positive in 8 out of 11 patients with histologically proven insulinoma (73 %). All (18)F-FDOPA PET/CT-avid insulinomas were detected on early images and 5 of 11 (45 %) on delayed ones. The tumour/normal pancreas uptake ratio was not significantly different between early and delayed acquisitions. Considering all patients with HH, including those without imaging evidence of disease, the detection rate of the primary lesions using CD-assisted (18)F-FDOPA PET/CT was 53 %, showing 9 insulinomas in 17 studies performed. In the control group (without CD premedication, eight patients), the final diagnosis was benign insulinoma in four, nesidioblastosis in one, and no definitive diagnosis in the remainder. (18)F-FDOPA PET/CT failed to detect any tumour in these patients. CONCLUSION: According to our experience, CD administration before (18)F-FDOPA injection leads to low residual pancreatic (18)F-FDOPA activity preserving tumoral uptake with consequent insulinoma detection in more than half of adult patients with HH and more than 70 % of patients with a final diagnosis of insulinoma. If (18)F-FDOPA PET/CT is indicated, we strongly recommend combining CD premedication with early acquisition centred over the pancreas.


Asunto(s)
Dihidroxifenilalanina/análogos & derivados , Hiperinsulinismo/diagnóstico por imagen , Insulinoma/diagnóstico por imagen , Neoplasias Pancreáticas/diagnóstico por imagen , Tomografía de Emisión de Positrones , Radiofármacos , Tomografía Computarizada por Rayos X , Adulto , Anciano , Anciano de 80 o más Años , Carbidopa , Femenino , Humanos , Masculino , Persona de Mediana Edad , Imagen Multimodal , Premedicación
17.
Med Sci (Paris) ; 30(10): 896-901, 2014 Oct.
Artículo en Francés | MEDLINE | ID: mdl-25311025

RESUMEN

The small intestine plays a crucial role in dietary and biliary cholesterol absorption, as well as its lymphatic secretion as chylomicrons (lipoprotein exogenous way). Recently, a new metabolic pathway called TICE (trans-intestinal excretion of cholesterol) that plays a central role in cholesterol metabolism has emerged. TICE is an inducible way, complementary to the hepatobiliary pathway, allowing the elimination of the plasma cholesterol directly into the intestine lumen through the enterocytes. This pathway is poorly characterized but several molecular actors of TICE have been recently identified. Although it is a matter of debate, two independent studies suggest that TICE is involved in the anti-atherogenic reverse cholesterol transport pathway. Thus, TICE is an innovative drug target to reduce -cardiovascular diseases.


Asunto(s)
Colesterol/metabolismo , Eliminación Intestinal , Mucosa Intestinal/metabolismo , Animales , Transporte Biológico , Humanos , Lipoproteínas/metabolismo
18.
J Med Chem ; 67(8): 6610-6623, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38598312

RESUMEN

Inhibition of the biosynthesis of bacterial heptoses opens novel perspectives for antimicrobial therapies. The enzyme GmhA responsible for the first committed biosynthetic step catalyzes the conversion of sedoheptulose 7-phosphate into d-glycero-d-manno-heptose 7-phosphate and harbors a Zn2+ ion in the active site. A series of phosphoryl- and phosphonyl-substituted derivatives featuring a hydroxamate moiety were designed and prepared from suitably protected ribose or hexose derivatives. High-resolution crystal structures of GmhA complexed to two N-formyl hydroxamate inhibitors confirmed the binding interactions to a central Zn2+ ion coordination site. Some of these compounds were found to be nanomolar inhibitors of GmhA. While devoid of HepG2 cytotoxicity and antibacterial activity of their own, they demonstrated in vitro lipopolysaccharide heptosylation inhibition in Enterobacteriaceae as well as the potentiation of erythromycin and rifampicin in a wild-type Escherichia coli strain. These inhibitors pave the way for a novel treatment of Gram-negative infections.


Asunto(s)
Antibacterianos , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/síntesis química , Humanos , Bacterias Gramnegativas/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Relación Estructura-Actividad , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/síntesis química , Escherichia coli/efectos de los fármacos , Escherichia coli/enzimología , Cristalografía por Rayos X , Sinergismo Farmacológico , Células Hep G2 , Modelos Moleculares , Ácidos Hidroxámicos/química , Ácidos Hidroxámicos/farmacología , Ácidos Hidroxámicos/síntesis química , Zinc/química
19.
Int J Stroke ; 19(3): 322-330, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37731173

RESUMEN

BACKGROUND: Carotid tandem lesions ((TL) ⩾70% stenosis or occlusion) account for 15-20% of acute stroke with large vessel occlusion. AIMS: We investigated the safety and efficacy of intravenous tenecteplase (0.25 mg/kg) versus intravenous alteplase (0.9 mg/kg) in patients with carotid TL. METHODS: This is a substudy of the alteplase compared with the tenecteplase trial. Patients with ⩾70% stenosis of the extracranial internal carotid artery (ICA) and concomitant occlusion of the intracranial ICA, M1 or M2 segments of the middle cerebral artery on baseline computed tomography angiography (CTA) were included. Primary outcome was 90-day-modified Rankin Scale (mRS) 0-1. Secondary outcomes were mRS 0-2, mortality, and symptomatic ICH (sICH). Angiographic outcomes were successful recanalization (revised Arterial Occlusive Lesion (rAOL) 2b-3) on first and successful reperfusion (eTICI 2b-3) on final angiographic acquisitions. Multivariable mixed-effects logistic regression was performed. RESULTS: Among 1577 alteplase versus tenecteplase randomized controlled trial (AcT) patients, 128 (18.8%) had carotid TL. Of these, 93 (72.7%) underwent intravenous thrombolysis plus endovascular thrombectomy (IVT + EVT), while 35 (27.3%) were treated with IVT alone. In the IVT + EVT group, tenecteplase was associated with higher odds of 90-day-mRS 0-1 (46.0% vs. 32.6%, adjusted OR (aOR) 3.21; 95% CI = 1.06-9.71) compared with alteplase. No statistically significant differences in rates of mRS 0-2 (aOR 1.53; 95% CI = 0.51-4.55), initial rAOL 2b-3 (16.3% vs. 28.6%), final eTICI 2b-3 (83.7% vs. 85.7%), and mortality (18.0% vs. 16.3%) were found. SICH only occurred in one patient. There were no differences in outcomes between thrombolytic agents in the IVT-only group. CONCLUSION: In patients with carotid TL treated with EVT, intravenous tenecteplase may be associated with similar or better clinical outcomes, similar angiographic reperfusion rates, and safety outcomes as compared with alteplase.


Asunto(s)
Arteriopatías Oclusivas , Isquemia Encefálica , Procedimientos Endovasculares , Accidente Cerebrovascular , Humanos , Isquemia Encefálica/terapia , Constricción Patológica , Procedimientos Endovasculares/métodos , Fibrinolíticos/efectos adversos , Accidente Cerebrovascular/terapia , Tenecteplasa/uso terapéutico , Trombectomía/métodos , Activador de Tejido Plasminógeno/efectos adversos , Resultado del Tratamiento
20.
Stroke ; 44(3): 671-4, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23390118

RESUMEN

BACKGROUND AND PURPOSE: The use of magnetic resonance imaging (MRI) after transient ischemic attack (TIA) or minor stroke may be affected by the relative timing of imaging. We measured the impact of scanning an individual patient late versus early after TIA and minor stroke. METHODS: Two hundred sixty-three TIA or minor stroke (National Institute of Health Stroke Scale score ≤3) patients with a baseline MRI completed within 24 hours of symptom onset and a follow-up MRI at 90 days were included. Baseline and 90-day scans were assessed independently for the presence of any stroke lesions that could explain the presenting symptoms. The presence and pattern of any stroke lesions were compared at the 2 time points. RESULTS: The presence of a stroke (acute or chronic) in any location was more common on baseline MRI versus 90-day MRI (68% vs 56%; P=0.005). Thirty percent of subjects with negative scans at 90 days had a clearly identifiable stroke at baseline. When interpreted blinded to the baseline scan, the presumed relevant lesion on the 90-day MR scan was the correct lesion in only 53% patients. One-third (34%) of patients had a different lesion pattern on the baseline scan compared with the 90-day scan. Ninety percent (80/89) of these patients had more lesions on the baseline MRI and 10% (9/89) had new lesions on the 90-day MRI. CONCLUSIONS: Delayed MRI after TIA or minor stroke reduces the diagnostic yield and results in missed understanding of the lesion pattern. MRI of minor stroke and TIA patients should occur early after symptom onset, and delayed imaging should be interpreted with caution.


Asunto(s)
Ataque Isquémico Transitorio/patología , Imagen por Resonancia Magnética , Índice de Severidad de la Enfermedad , Accidente Cerebrovascular/patología , Anciano , Anciano de 80 o más Años , Encéfalo/patología , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Ataque Isquémico Transitorio/diagnóstico , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sensibilidad y Especificidad , Accidente Cerebrovascular/diagnóstico , Factores de Tiempo
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