MECANISMO MOLECULAR DE LAS ESTATINAS EN EL TRATAMIENTO DE LA ERITROCITOSIS PATOLÓGICA DE ALTURA Translated title: MOLECULAR MECHANISM OF STATINS IN THE TREATMENT OF HIGH ALTITUDE PATHOLOGICAL ERYTHROCYTOSIS

Abstract

Introducción La Eritrocitosis Patológica de Altura es la manifestación hematológica de la Enfermedad Crónica de Altura, por adaptación inadecuada a grandes alturas de genes reguladores de la eritropoyesis. Las estatinas son inhibidores de la vía del mevalonato involucrado en la regulación de la eritropoyesis. El presente trabajo describe los mecanismos moleculares de la inhibición de la eritropoyesis en pacientes con eritrocitosis patológicas. Material y métodos Se estudiaron 35 pacientes con eritrocitosis patológicas con radicatorias en las ciudades de La Paz y El Alto (3600 y 4000 msnm respectivamente). Se realizaron Cultivo de células progenitoras hematopoyéticas y Western Blot. Resultados Statins induce apoptosis of erythroid progenitors in the cell culture medium. Without the supplement of simvastatin the apoptosis was 12.3% and With simvastatin the apoptosis was 38.4% (p = 0.001). Furthermore statins inhibit the proliferation and differentiation of erythroid progenitors. Conclusiones Los mecanismos moleculares involucrados en la inhibición de la eritropoyesis son: a) Bloqueo de la isoprenilación de Rho y Ras, b) Inhibición de la fosforilación de Jak-2 y Stat-5, c) inhibición de la glicosilación del EpoR, d) Disminución de colesterol en microdominios de la membrana celular (raft lipid), e) Inducción de apoptosis a través de BCLxL y caspasa 9.

Translated abstract

Introduction The High altitude Pathological Erythrocytosis is the chronic mountain sickness hematologic manifestation by inadequate adaptation to high altitudes of genes regulating erythropoiesis. Statins are inhibitors of the mevalonate pathway involved in the regulation of erythropoiesis. This paper describes the molecular mechanisms of erythropoiesis inhibitionin patients with pathological erythrocytosis. Material and methods We studied 35 patients with pathological erythrocytosis from La Paz and El Alto city (3600 and 4000 masl respectively). Were performed hematopoietic progenitor cell culture and Western blotting. Results Statins induce apoptosis in liquid culture medium. without simvastatin erythroid progenitors from apoptosis presentarón and 12.3% in the group supplemented with simvastatin 38.4% apoptosis (p = 0.001), statins also inhibit the proliferation and differentiation of erythroid progenitors, and inhibit transcription of STAT-5. Conclusions The molecular mechanisms involved in the erythropoiesis inhibition are: a) Inhibition of Ras and Rho isoprenylation, b) Inhibition of Jak-2 and Stat-5 phosphorylation, c) inhibition of EpoR glycosylation, d) Statins reduce lipid rafts cholesterol and reduce JAK2 localization to lipid rafts, e) Induction of apoptosis through caspase 9 and BclxL.