Migrasomes, a novel organelle first reported by Professor Li Yu’ s team in 2015, are vesicular structures with diameters ranging from 0.5 to 3 micrometers that form on the retraction fibers at the rear of migrating cells. These structures contain various biomolecules such as proteins, nucleic acids, and lipids, along with numerous small vesicles, each approximately 50 nanometers in diameter. Migrasomes act as conduits for information and material exchange between cells and their microenvironments, participating in essential physiological and pathological processes such as embryonic development, angiogenesis, immune responses, and tumorigenesis. In recent years, as the mechanisms and biological functions of migrasomes have been elucidated, a methodological framework for studying migrasomes has gradually emerged, laying the foundation for further research advancements.

Migrasomes possess a distinctive morphology and have a lifespan of several hours, making them well-suited for high-quality optical microscopy imaging. Therefore, optical imaging systems have become the most direct and reliable method for detecting and analyzing migrasomes. Based on published studies and the authors’ own research experiences, this article outlines a protocol for observing migrasomes using optical microscopy. It also summarizes the information on proteins, dyes, and antibodies that can be used to label migrasomes, and details the steps for constructing an in vitro migrasome reconstitution system. These protocols provide a basic operational guide for high-quality migrasome observation. However, given the diversity of research objectives and the complexity of migrasomes, the authors recommend that researchers may need to tailor the experimental procedures to their specific needs. As our understanding of migrasomes deepens and technologies evolve, the methodologies for migrasome imaging are expected to be continuously updated, thereby facilitating further advances in migrasome biology. The work entitled “Seeing is believing: observation of migrasomes” was published on Biophysics Reports (published on February 2, 2024).

Image:Migrasome images of Tetraspanin4-GFP over-expressed L929 cells were collected by confocal microscopy at a proper focal plane or improper (Upper or Lower) focal plane. Scale bar, 10 m.

Reference: Yuwei, H. and Y. Li (2024). "Seeing is believing: observation of migrasomes." Biophysics Reports 9: 1-15.   http://www.biophysics-reports.org/en/article/doi/10.52601/bpr.2023.230024

Key points:

Step-by-step Procedure

l Cell culture protocol for migrasome observation.

l Labeling of migrasomes using fluorescent proteins, dyes, and antibodies.

l Purification and insertion of proteins onto liposomes for in vitro reconstitution.

l Imaging of migrasomes and statistical analysis.

Advantages and Limitations

Ø Standardized protocol for observing migrasomes.

Ø Provides analysis of migrasome characteristics and supports biogenesis research.

Ø In vitro system offers new perspectives on migrasome formation mechanisms.

Ø Statistical methods provide objective judgments on impacts on migrasomes.

About Biophysics Reports

Biophysics Reports is an international, open-access journal that serves as a worldwide forum, which publishes novel theories, methods, and protocols, as well as significant improvements in basic research techniques across multidisciplinary areas of the biological and biomedical sciences. The article types include: Commentaries, Methods, Protocols, Research articles, and Reviews.The Editor-in-Chief is Academician Tao Xu from Institute of Biophysics, Chinese Academy of Sciences (CAS). Biophysics Reports has been indexed by PubMed Central, SCOPUS, CSCD etc.

Lysosomes are critical for cellular degradation, characterized by their acidic pH and array of hydrolytic enzymes. They degrade materials through endocytosis, phagocytosis, and autophagy, recycling essential components. Lysosomes also participate in vital cellular processes, and their dysfunction contributes to diseases such as lysosomal storage diseases, neurodegenerative disorders, and cancer. Research methods and tools have been developed to study lysosomes in cultured cells, C. elegans, and mice, key model systems. In cultured cells, lysosomes can be characterized and their functions investigated. C. elegans, with its short life cycle and genetic tools, offers a straightforward model for studying lysosomes in development and aging. In mice, transgenic models expressing lysosomal proteins provide insights into lysosomal function in vivo. While the well-established tools will continue to contribute to the study of lysosomal biology, it is necessary to develop novel assays for a better understanding of lysosomal functions in diverse physiological and pathological conditions. The methods and techniques summarized in this review provide a foundation for understanding lysosomal biology and exploring potential therapeutic targets. The review entitled “Exploring lysosomal biology: current approaches and methods” was published on Biophysics Reports (published on January, 2024).

Key points:

l Studying Lysosomes in Cultured Cells: Antibodies, pH-sensitive dyes, and genetically-encoded sensors are employed to identify lysosomes and study their acidification, maturation, integrity, and numbers.

l Using C. elegans as a Model to Study Lysosomes: Genetic fluorescent reporters are utilized to track lysosomal maturation, acidification, and degradation activity, as well as to investigate damaged lysosomes.

l Studying Lysosomes in Mice: Histological and in vivo imaging studies in mice offer an understanding of lysosomal function at the organism level.

Image: Commonly  used  fluorescent  dyes  and  protein  markers  for  lysosomes.  

Reference:Qiuyuan, Y. and Y. Chonglin (2024). "Exploring lysosomal biology: current approaches and methods." Biophysics Reports 9: 1-10. http://dx.doi.org/10.52601/bpr.2023.230028

About Biophysics Reports

Biophysics Reports is an international, open-access journal that serves as a worldwide forum, which publishes novel theories, methods, and protocols, as well as significant improvements in basic research techniques across multidisciplinary areas of the biological and biomedical sciences. The article types include: Commentaries, Methods, Protocols, Research articles, and Reviews.The Editor-in-Chief is Academician Tao Xu from Institute of Biophysics, Chinese Academy of Sciences (CAS). Biophysics Reports has been indexed by PubMed Central, SCOPUS, CSCD etc.