The role of CD44 protein in synapse phagocytosis by astrocytes in vitro

• Autorzy: Chwedorowicz A. , Kaza B. , Zareba-Koziol M. , Konopka A. , Wilczynski G.M. , Dzwonek J.
• Języki publikacji: EN

Abstrakty

EN

INTRODUCTION: CD44 adhesion molecule is highly expressed in astrocytes but its role in these cells is unknown. Recently a novel function of astrocytes in the brain in synapse phagocytosis has been described but the molecular mechanisms underlying these processes remain largely unknown. Phagocytic receptors MEGF10 and MERTK have been shown to be involved in this phenomenon. However, CD44 was shown to act as phagocytic receptor in macrophages. We hypothesized that CD44 can regulate phagocytosis in astrocytes and can be involved in synapse elimination. To investigate the role of CD44 in astrocyte-mediated synapse pruning, we used an in vitro engulfment assay, where astrocytes were cultured in the presence of synaptoneurosomes. We investigated whether altered CD44 expression level in astrocytes influence the efficiency of engulfement of synaptoneurosomes conjugated with a pH‑sensitive fluorescent dye. AIM(S): The aim of our work was to determine whether CD44 protein regulates synapse phagocytosis by astrocytes in vitro. METHOD(S): To check if CD44 regulates synapse phagocytosis by astrocytes we used primary astrocytes cultures in vitro that were transfected with specific CD44shRNA to knockdown CD44 expression or controls (empty pSuper). Astrocytes were cultured in the presence of synaptoneurosomes conjugated with pHrodo fluorescent dye. The amount of synaptoneurosomes engulfed by astrocytes were monitored in living cells with the use of confocal microscopy. Three-dimentional reconstructions of astrocytes and analysis of engulfed puncta were performed using Imaris software. Live imaging of transfected cells before and after incubation with fluorescently labaled synaptoneurosomes were performed. RESULTS: We observed significantly higher number of engulfed puncta inside CD44 depleted cells comparing to controls. CONCLUSIONS: Our results suggest that CD44 inhibits phagocytosis of synaptoneurosomes by astrocytes. FINANCIAL SUPPORT: The work was supported by the National Science Center grant No 2015/17/B/ NZ4/02540.

• Wydawca: -
• Czasopismo: Acta Neurobiologiae Experimentalis
• Rocznik: 2017
• Tom: 77
• Numer: Suppl.1
• Opis fizyczny: p.106-107

Twórcy

autor

Chwedorowicz A.

• Institute of Experimental Biology, Department of Neurophysiology, Laboratory of Molecular and Systemic Neuromorphology, Warsaw, Poland

autor

Kaza B.

• Institute of Experimental Biology, Neurobiology Center, Laboratory of Molecular Neurobiology, Warsaw, Poland

autor

Zareba-Koziol M.

• Institute of Experimental Biology, Department of Molecular and Cellular Neurobiology, Laboratory of Cell Biophysics, Warsaw, Poland

autor

Konopka A.

• Institute of Experimental Biology, Department of Neurophysiology, Laboratory of Molecular and Systemic Neuromorphology, Warsaw, Poland

autor

Wilczynski G.M.

• Institute of Experimental Biology, Department of Neurophysiology, Laboratory of Molecular and Systemic Neuromorphology, Warsaw, Poland

autor

Dzwonek J.

• Institute of Experimental Biology, Department of Neurophysiology, Laboratory of Molecular and Systemic Neuromorphology, Warsaw, Poland