Exosomes are nanometer-sized extracellular vesicles that contain various molecules (DNA, RNA, proteins, lipids). They can be released from almost all cell types and play a vital role in intercellular communication. Scientists have taken advantage of the unique properties of exosomes to promote clinical diagnostics and therapeutics development. Here, we give a brief introduction to the applications of exosomes in diagnostics. Besides, to aid in exosome research, Creative Biolabs is offering a comprehensive array of exosome-related services.

Rationale

Exosomes have a unique and complex composition. Thousands of proteins have been identified, which include membrane transporters, fusion proteins, heat shock proteins, tetraspanins, biogenesis proteins, etc. Besides, exosomes are rich in lipids, including cholesterol, sphingolipids, phospholipids, and bisphosphonates, some of which are important for exosomal functions. Moreover, exosomes also contain nucleic acids such as mRNAs and miRNAs, which may be shuttled to recipient cells and affect their protein production. However, under pathological conditions, the composition of exosomes could be altered, which makes exosomes and their compositions potential disease markers for diagnosis and prognosis.

Fig.1 Proteins and RNAs commonly found within exosomes. (Peterson, 2015)

Diseases & Biomarkers

Over the past few years, numerous studies have demonstrated that exosomes contain nucleic acids and proteins implicated in cancer as well as neurodegenerative, metabolic, infectious, and other diseases. These studies highlight the prospects of using exosomes as diagnostic tools to enhance early detection. Besides, exosomes can also be used as a prognostic tool, to differentiate between different types of diseases that have similar symptoms, and to monitor treatment. Table 1 lists altered protein or RNA cargo in body fluid-derived exosomes from patients with a broad range of diseases, covering central nervous system diseases, cancers, liver and kidney diseases. These exosomes are isolated from easily attainable biofluids such as blood and urine, which offers them many advantages over tissue biopsy approaches：

• Easily attainable samples and do no harm to human body
• Continuous, long-term monitoring of patient response to a therapy over the course of treatment
• Reveal comprehensive molecular information about a tumor without taking tissue from the tumor
• Sample diversity: blood, CSF, plasma, serum, urine, saliva, ascites fluid

Table.1 Exosomes and exosomal cargo as biomarker for diseases. (Lässer, 2015)

Procedures for Diagnosis

The general procedures for exosome diagnosis require the following key steps:

• Exosomes are firstly isolated from biofluids with appropriate isolation and purification tools. Creative Biolabs offers exosome isolation and purification services from sources such as cell cultures, plasma, urine, serum, CSF, ascites fluid, and saliva. We utilize ultracentrifugation, microfiltration, size exclusion chromatography, and immunoaffinity tools to isolate exosome in a high-quantity manner.
• Then, the contents of exosomes are isolated and analyzed using different analytical techniques. Creative Biolabs offers exosome profiling services to analyze the exosomal contents such as RNA, proteins, and cfDNA. Frequently used molecular techniques for nucleic acids profiling include PCR, qPCR, microarray, and next-generation sequencing (NGS). Protein contents can be determined using proteomic techniques such as mass spectrometry. We also offer exosome proteomics, and lipidomics and metabolomics analysis services.

Please feel free to contact us if you are interested in our services.

References:

1. Peterson, M.F.; et al. Integrated systems for exosome investigation. Methods. 2015, 87:31-45.
2. Lässer C. Exosomes in diagnostic and therapeutic applications: biomarker, vaccine and RNA interference delivery vehicle. Expert Opinion on Biological Therapy. 2015, 15(1):103-17.

Related Services:

• Therapeutic Application of Exosomes
• Vaccine Development
• Stem Cell-derived Exosomes