Por:
Rogelio Salmona
|
Fecha:
2016
Insulin hormone is produced by pancreatic beta-cells and its biosynthesis, secretion, and intracellular degradation is tightly regulated. Newly formed SGs are preferentially released upon glucose stimulation while aged SGs are less competitive to be released and are more prompt to degradation mainly within lysosomes. The most assumed mechanism leading aged SGs to lysosome is autophagy, a degradation system for altered proteins and damaged organelles. The autophagic marker LC3 has facilitated the detection of autophagy through LC3-based biochemical and microscopic assays, as well as the possibility to experimentally manipulate the autophagy pathway. Here, we intended to establish a model for the further study of mechanism that target aged Ins-SNAPTMR-Star+ SGs to GFP-LC3+ autophagosomes in INS-1 cells by using three different approaches. Our results show that in INS-1 cells, modulation of autophagy with chemical agents can be detected by western blot. Likewise, TIRF Microscopy allowed for the detection of positive GFP-LC3+ aged Ins-SNAPTMR-Star+ objects in the cortical region of INS-1 cells. Additionally, we implemented SIM microscopy to gain more detail in the morphological aspect of autophagosomes vesicles. Despite some hints about the autophagosomal structures were uncovered through these approaches, further experiments should be performed to complement and confirm our findings. Thus, establishment of a suitable model for the study of autophagy, will allow us to further study the mechanisms behind the targeting process of aged SGs and to better understand how impairment of autophagy contributes to deterioration of pancreatic beta-cell function and subsequent onset of type 2 diabetes.