Role of KCNK3 Dysfunction in Dasatinib-associated Pulmonary Arterial Hypertension and Endothelial Cell Dysfunction.

Pulmonary arterial (PA) hypertension (PAH) is a severe cardiopulmonary disease that may be triggered by exposure to drugs such as dasatinib or facilitated by genetic predispositions. The incidence of dasatinib-associated PAH is estimated at 0.45%, suggesting individual predispositions. The mechanisms of dasatinib-associated PAH are still incomplete. We discovered a KCNK3 gene (Potassium channel subfamily K member 3; coding for outward K+ channel) variant in a patient with dasatinib-associated PAH and investigated the impact of this variant on KCNK3 function. Additionally, we assessed the effects of dasatinib exposure on KCNK3 expression. In control human PA smooth muscle cells (hPASMCs) and human pulmonary endothelial cells (hPECs), we evaluated the consequences of KCNK3 knockdown on cell migration, mitochondrial membrane potential, ATP production, and in vitro tube formation. Using mass spectrometry, we determined the KCNK3 interactome. Patch-clamp experiments revealed that the KCNK3 variant represents a loss-of-function variant. Dasatinib contributed to PA constriction by decreasing KCNK3 function and expression. In control hPASMCs, KCNK3 knockdown promotes mitochondrial membrane depolarization and glycolytic shift. Dasatinib exposure or KCNK3 knockdown reduced the number of caveolae in hPECs. Moreover, KCNK3 knockdown in control hPECs reduced migration, proliferation, and in vitro tubulogenesis. Using proximity labeling and mass spectrometry, we identified the KCNK3 interactome, revealing that KCNK3 interacts with various proteins across different cellular compartments. We identified a novel pathogenic variant in KCNK3 and showed that dasatinib downregulates KCNK3, emphasizing the relationship between dasatinib-associated PAH and KCNK3 dysfunction. We demonstrated that a loss of KCNK3-dependent signaling contributes to endothelial dysfunction in PAH and glycolytic switch of hPASMCs.

Comparative analysis of antiproliferative and vasodilator effects of drugs for pulmonary hypertension: Extensive in vitro study in rats and human.

An effective pulmonary hypertension (PH) treatment should combine antiproliferative and vasodilator effects. We characterized a wide-range of drugs comparing their anti-proliferative vs vasodilator effects in human and rat pulmonary artery smooth muscle cells (PASMC). Key findings: 1) Approved PH drugs (PDE5 inhibitors, sGC stimulators and PGI2 agonists) are preferential vasodilators. 2) cGMP stimulators were more effective in cells derived from hypertensive rats. 3) Nifedipine acted equally as vasodilator and antiproliferative. 4) quercetin and imatinib were potent dual vasodilator/antiproliferative drugs. 5) Tacrolimus and levosimendan lacked antiproliferative effects. 6) Forskolin, pinacidil and hydroxyfasudil were more effective as antiproliferative in human cells.

Protección cardiovascular con flavonoides. Enigma farmacocinético / Cardiovascular protection by flavonoids. Pharmacokinetic mystery

Objetivos: Los flavonoides ejercen efectos beneficiosos en la prevención de las enfermedades cardiovasculares. En esta revisión trataremos de clarificar algunas preguntas fundamentales respecto a la eficacia, mecanismo de acción y biodisponibilidad de uno de los flavonoides dietéticos más abundante, la quercetina. Métodos: Se utilizó la base de datos de la National Library of Medicine, Washington, DC (MEDLINE: PubMed). Se recopilaron todos los estudios en animales y en humanos disponibles online desde la creación de la base de datos hasta Noviembre de 2015. Resultados: La quercetina produce un efecto vasodilatador y antihipertensor en modelos animales y en individuos hipertensos. Es eficaz en todos los modelos de hipertensión analizados, independientemente del origen de la hipertensión, del estado del sistema renina-angiotensina, del estrés oxidativo, del óxido nítrico y de otros factores. Paradójicamente, a pesar de ejercer efectos sistémicos biológicamente demostrables, no se encuentra en el plasma tras su administración oral y sus metabolitos circulantes muestran una débil actividad in vitro. La quercetina es extensamente metabolizada en derivados metilados y glucurono- y sulfo-conjugados, que son las formas circulantes en el plasma; y glucurono-, pero no sulfo-conjugados, pueden ser hidrolizados a nivel vascular, produciendo la aglicona matriz que se acumula en los tejidos. La conjugación es un proceso reversible y, al menos con respecto a los efectos vasodilatador y antihipertensivo, el ciclo de conjugación-deconjugación parece ser un requisito absoluto. Conclusiones: Los glucurono-conjugados transportan la quercetina y su forma metilada, y liberan en los tejidos la aglicona libre, que es el efector final

Objetives: Flavonoids have been proposed to exert beneficial effects in the prevention of cardiovascular diseases. In this review we try to clarify some fundamental questions regarding efficacy, mechanism of action and bioavailability of one of the most widely distributed flavonoids in the diet, quercetin. Methods: The database of the National Library of Medicine, Washington, DC (MEDLINE PubMed) was used and all the studies in animals and humans available from inception of the database until November 2015 were collected. Results: Quercetin exerts vasodilatory and antihypertensive effects in animal models of hypertension and hypertensive subjets. Quercetin is effective in all models of hypertension analyzed, independently of the origin of the hypertension, the status of renin-angiotensin system, oxidative stress, nitric oxide, and other factors. Paradoxically, despite exerting biologically demonstrable systemic effects, it is not found in plasma after oral administration and its circulating metabolites show weak activity in vitro. Quercetin is extensively metabolized into methylated and glucurono- and sulfo-conjugated metabolites, which are the plasma circulating forms; and glucurono-, but not sulfo-conjugates, can be hydrolyzed at the vascular level, yielding the parent aglycone which accumulates in tissues. Thus conjugation is a reversible process and, at least regarding the vasodilator and antihypertensive effects, the conjugation-deconjugation cycle appears to be an absolute requirement. Conclusions: Glucuronidated derivatives transport quercetin and its methylated form, and deliver to the tissues the free aglycone, which is the final effector

Respuesta de las arterias pulmonares de lechón al óxido nítrico y a dadores de óxido nítrico: Evolución con la edad postnatal y modulación por el estrés oxidativo / Nitric oxide- and nitric oxide donor-induced responses in piglet pulmonary arteries: Postnatal maturation and modulation by oxidative stress

En el presente estudio hemos analizado la influencia de la edad postnatal y los cambios en el nivel de estrés oxidativo sobre la vasodilatación pulmonar in vitro inducida por el NO endógeno, el NO exógeno y donadores de NO. Se han utilizado las arterias pulmonares procedentes de lechones de 1 día y de 2 semanas de edad para el registro de la fuerza contráctil. En las arterias pulmonares de lechones de 1 y 15 días de edad, el estrés oxidativo basal modula la acción vasodilatadora del NO, siendo la NAD(P)H oxidasa de la adventicia la principal fuente endógena del anión superóxido. La vasodilatación inducida por el NO de origen endotelial y por el NO exógeno aumenta con la edad, posiblemente por un incremento en la actividad de la ciclooxigenasa-1 en los primeros momentos de vida extrauterina que modularía el efecto vasodilatador del NO. Finalmente, encontramos que el NO y los donadores de NO, SNAP y nitroprusiato (SNP), difieren en la cinética y distribución regional de la liberación del NO, lo que influye en la susceptibilidad para la inactivación por el anión superóxido y por la oxihemoglobina (AU)