Impaired Autophagy flux in Müller cells exposed to hypoxia: in vitro and in vivo models.

SUBIRADA, P. V.; RIDANO, ME; PAZ, M.C.; FADER KAISER, C; CHIABRANDO, G. A.; SANCHEZ, M.C.

Córdoba Capital

Congreso; LII Reunion SAIB 2016; 2016

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

Hypoxia is one of the main insults in Diabetic Retinopathy(DR) and Retinopathy of Prematurity (ROP), leading to neovascularization and neurodegeneration. In this pathological context, Glial Müller Cells(GMC) has been reported to participate in retinal homeostasis maintenance by eliminating protein aggregates, activating stress proteins and detoxifying mechanisms. This study aimed to investigate whether autophagy is involved in GMC response under hypoxia. MIO-M1, a human immortalized cell line of GMC, were pre incubated with cloroquine 10u M and exposed to CoCl2 250u M for 24hs. Western blot and immunofluorescence analysis revealed increased levels of LC3B II and p62/SQTSM1but decreased colocalization of LC3 and lysotracker. In a similar experiment, MIO-M1 were exposed to 0,1%O2. In addition, autophagy flux was determined in the OIR mice model, which closely resemble ROP and DR. C57/BL6 mice exposed to 75% O2 from postnatal day (P) 7 to 12, were brought to room air (RA) for additional five(P17) or nine days(P26). Age-matched mice maintained in RA were used as control. Western blot of neural retinas showed changes in autophagy flux and glutamine syntethase, total caspase 3 and stress protein levels at p12, p17 and p26.A distinct pattern of LC3 was visualized at the end feet of GMC by inmunofluorescence staining. Our results suggest that hypoxia modifies autophagy flux in GMC.