Super-Resolution Microscopy Revealed the Lysosomal Expansion During Epigallocatechin Gallate-Mediated Apoptosis

Direct visualization of the dynamic events in lysosomes during drug-mediated programmed cell death (apoptosis) is a great challenge. This is due to the lack of resolving power of a conventional microscope and also the unavailability of a suitable multimodal probe that simultaneously can carry the drug with high loading capacity and ensure its specific internalization into lysosomes. In this work, using super-resolution microscopy, we observed the lysosomal expansion during apoptosis that was treated with epigallocatechin gallate (EGCG) conjugated to bovine serum albumin (BSA). Albumin protein is known to internalize into lysosomes via endocytosis, thus helping in the specific delivery of EGCG to the lysosomal compartment. The conjugation of EGCG to BSA not only helped in increasing the killing efficiency of cancer cells but it also reduces the side effects and produces minimal reactive oxygen species. The decrease in local viscosity helped in lysosomal expansion during apoptosis.

Automated summary

This study used super-resolution microscopy to observe lysosomal expansion during apoptosis treated with epigallocatechin gallate (EGCG) conjugated to bovine serum albumin (BSA). The conjugation of EGCG to BSA helped deliver EGCG to lysosomes specifically, increasing cancer cell killing efficiency, reducing side effects, and minimizing reactive oxygen species production. The decrease in local viscosity during apoptosis contributed to lysosomal expansion.