PPARß/δ-dependent MSC metabolism determines their immunoregulatory properties.

Mesenchymal stem cell (MSC)-based therapy is being increasingly considered a powerful opportunity for several disorders based on MSC immunoregulatory properties. Nonetheless, MSC are versatile and plastic cells that require an efficient control of their features and functions for their optimal use in clinic. Recently, we have shown that PPARß/δ is pivotal for MSC immunoregulatory and therapeutic functions. However, the role of PPARß/δ on MSC metabolic activity and the relevance of PPARß/δ metabolic control on MSC immunosuppressive properties have never been addressed. Here, we demonstrate that PPARß/δ deficiency forces MSC metabolic adaptation increasing their glycolytic activity required for their immunoregulatory functions on Th1 and Th17 cells. Additionally, we show that the inhibition of the mitochondrial production of ATP in MSC expressing PPARß/δ, promotes their metabolic switch towards aerobic glycolysis to stably enhance their immunosuppressive capacities significantly. Altogether, these data demonstrate that PPARß/δ governs the immunoregulatory potential of MSC by dictating their metabolic reprogramming and pave the way for enhancing MSC immunoregulatory properties and counteracting their versatility.

Esferocitosis hereditaria: presentación y evolución en un lactante menor: reporte de un caso / Hereditary spherocytosis: presentation and evolution in an infant: report of a case

Introducción: La esferocitosis hereditaria es la causa más común de anemia hemolítica crónica en Estados Unidos y Europa, con una incidencia de 1 cada 5.000 nacimientos. Se debe a una alteración de la membrana eritrocitaria. Los pacientes afectados pueden permanecer asintomáticos, con una hemólisis mínima, o desarrollar una anemia hemolítica severa. Presentación del caso: Lactante menor de 3 meses, con antecedentes de ictericia neonatal prolongada hasta la fecha de la consulta en policlínico de San Ignacio por regurgitación postprandial. Se realiza hemograma por presentar intensa palidez e ictericia, detectándose anemia severa, signos de hemólisis de eritrocitos e hiperbilirrubinemia de tipo indirecta. Se decide su hospitalización en Hospital Clínico Herminda Martin (HCHM), encontrándose hipoactivo, sin otros síntomas. Se transfunden 50cc de glóbulos rojos, evolucionando favorablemente. Durante la hospitalización se averigua el antecedente de prima que hace 6 años fue esplenectomizada por cuadros de anemia hemolítica recurrente durante 5 años. Se decide alta, tratamiento con ácido fólico e interconsulta con hematólogo. Discusión: Aunque la esferocitosis hereditaria se trata de la anemia hemolítica congénita más frecuente en Chile, su diagnóstico se dificulta de no conocerse antecedentes familiares o si no existe reticulocitosis ni esplenomegalia (como en este caso), lo que lleva a pensar en otras causas de anemia. Por esto, fue de importancia el antecedente familiar conocido tras su ingreso, pues orientó a un diagnóstico que en este caso no tenía una presentación típica.

Introduction: Hereditary spherocytosis is a common cause of hemolytic anemia due to an alteration of the erythrocyte membrane. Affected patients can remain asymptomatic, with a minimum hemolysis, or develop a severe hemolytic anemia. It is transferred as an autosomal dominant disease, less frequent as an autosomal recessive one, or with no medical history in the family. Case report: 3 month-old infant, with a medical history of neonatal ictericy lengthy so far, consultation at San Ignacio polyclinic because of a postprandial regurgitation, a hemogramis carried out by presenting intense paleness and ictericy, detecting severe anemia and indirect hyperbilirubinemia. It is decided to hospitalize him into Herminda Martin Clinic Hospital, being hypoactive, with no other symptoms. 50 cc red corpuscles are transfused, progressing favorably. During hospitalization it is found out the medical history of a cousin who was splenectomized due to hemolytic anemia symptoms recurring for 5 years. It is decided the discharge with a folic acid treatment and an interconsult with a hematologist. Discussion: Although the hereditary spherocytosis is the congenital hemolytic anemia more frequent in Chile, its diagnosis turns more complicated for an unknown medical history in the family, or if it does not present reticulocytosis nor splenomegaly (as in this case), which leads to think of other causes of anemia. Because of that it was very important the medical history of the family known after his admission into the hospital, because it directed towards a diagnosis that in this case did not have a typical presentation.