Autophagosomes in the cell

Autophagosomes (green) together with microtubules (red) and DAPI (blue) in SH-SY5Y neuroblastoma cells.

Autophagosomes play a crucial role in recycling, by degrading cellular components and providing building blocks for renewal och cell components. Last year, we published a post about autophagy, which was the subject of the 2016 Nobel Prize in Physiology and Medicine.

We show, for the first time, images of HPA antibodies that co-localize with the autophagosomes. These membrane bound vesicles are involved in degradation of cellular constituents through a process called autophagy. The protein detected is localized to the autophagosomes (green) in SH-SY5Y cells, a human neuroblastoma cell line from neural tissue.

Autophagy is a non-specific, bulk degradation process crucial to all living cells so that cellular components can be broken down and recycled (Dowaidar et al. 2017). Autophagosomes form in the close proximity of Endoplasmic reticulum, whose involvement is not entirely understood (Nishimura et al. 2017).

At the beginning of the process isolation membranes called phagophores are formed at the phagophore assembly site. The phagophores are then elongated and engulf, for example damaged proteins or organelles along with a portion of the cytosol to form mature autophagosomes (Sarkar et al. 2009). Ultimately, the mature autophagosomes fuse with the lysosome to form the degradative autophaolysosomes. In short, autophagosomes carry their cargo to the lysosomes where proteins, carbohydrates, lipids and even whole organelles are digested (Cudjoe et al. 2017).

The autophagic process occurs in cells at basal level and in response to stimuli such as starvation, chemotherapy and radiotherapy (Cudjoe et al. 2017). In recent years, autophagy has become a field of rapidly growing interest because of its essential function in all living cells. Defects or deregulation of the process are observed in several conditions including infections, neurodegenerative, cardiovascular and immune disorders, diabetes and cancer (Lippai & Szatmári 2017).

Written by: Anna Bäckström