Exosome subpopulations: The isolation and the functions in diseases

Two roads diverged in a cell: insights from differential exosome regulation in polarized cells

Exosomes are extracellular vesicles involved in intercellular signaling, carrying various cargo from microRNAs to metabolites and proteins. They are released by practically all cells and are highly heterogenous due to their origin and content. Several groups of exosomes are known to be involved in various pathological conditions including autoimmune, neurodegenerative, and infectious diseases as well as cancer, and therefore a substantial understanding of their biogenesis and release is crucial. Polarized cells display an array of specific functions originated from differentiated membrane trafficking systems and could lead to hints in untangling the complex process of exosomes. Indeed, recent advances have successfully revealed specific regulation pathways for releasing different subsets of exosomes from different sides of polarized epithelial cells, underscoring the importance of polarized cells in the field. Here we review current evidence on exosome biogenesis and release, especially in polarized cells, highlight the challenges that need to be combatted, and discuss potential applications related to exosomes of polarized-cell origin.

Hsa_circ_0001359 in Serum Exosomes: A Promising Marker to Predict Bronchopulmonary Dysplasia in Premature Infants

Objective

This prospective study is to explore the role of specific circRNAs in predicting the development of bronchopulmonary dysplasia (BPD).

Methods

From July 1, 2021 to December 1, 2021, peripheral blood samples were collected from 62 premature infants with gestational age (GA) ≤32 weeks on the 7th, 14th, and 28th day after birth. Then, on the 28th day, the included infants were divided into the BPD group and the non-BPD group according to the definition of BPD. Serum exosomal circRNAs from peripheral blood were identified, sequenced, and compared between the BPD and non-BPD groups at different time points. Specific differentially expressed circRNAs were further verified from another 42 enrolled premature infants (GA ≤32 weeks). The classical lung biological markers in serum were also measured simultaneously.

Results

Hsa_circ_0001359 in serum exosomes showed continuous differential expression between the BPD group and the non-BPD group on the 7th, 14th, and 28th day. Compared with that, classical lung biological markers like IL-6, IL-33, KL-6, and ET-1 did not exhibit continuous differences. Moreover, the expression of hsa_circ_0001359 on day 7 had a higher predictive value in predicting BPD (area under curve:0.853, 95% CI:0.738-0.968; adjusted odds ratio:6.033, 95% CI:2.373-13.326). The calibration curve further showed the mean absolute error = 0.033, mean squared error = 0.00231, and quantile of absolute error = 0.058.

Conclusion

Hsa_circ_0001359 in serum exosomes is a promising marker for predicting BPD in preterm infants with gestational age ≤32 weeks.

Recent progress of exosomal lncRNA/circRNA-miRNA-mRNA axis in lung cancer: implication for clinical application

Lung cancer is the leading cause of death among malignant tumors in the world. High lung cancer mortality rate is due to most of patients diagnosed at advanced stage. The Liquid biopsy of lung cancer have received recent interest for early diagnosis. One of the components of liquid biopsy is the exosome. The exosome cargos non-coding-RNAs, especially long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and microRNAs (miRNAs). The lung cancer derived exosomal non-coding RNAs play the pivotal roles of lung cancer in carcinogenesis, diagnosis, therapy, drug resistance and prognosis of lung cancer. Given ceRNA (competitive endogenous RNA) mechanism, lncRNA or circRNA can act as ceRNA to compete to bind miRNAs and alter the expression of the targeted mRNA, contributing to the development and progression of lung cancer. The current research progress of the roles of the exosomal non-coding-RNAs and the interplay of ceRNAs and miRNAs in mediated lung cancer is illustrated in this article. Hence, we presented an experimentally validated lung cancer derived exosomal non-coding RNAs-regulated target gene axis from already existed evidence in lung cancer. Then LncRNA/circRNA-miRNA-mRNA axis may be a potential target for lung cancer treatment and has great potential in the diagnosis and prognosis of lung cancer.

Outer Membrane Vesicles Released from Garlic Exosome-like Nanoparticles (GaELNs) Train Gut Bacteria that Reverses Type 2 Diabetes via the Gut-Brain Axis

Gut microbiota function has numerous effects on humans and the diet humans consume has emerged as a pivotal determinant of gut microbiota function. Here, a new concept that gut microbiota can be trained by diet-derived exosome-like nanoparticles (ELNs) to release healthy outer membrane vesicles (OMVs) is introduced. Specifically, OMVs released from garlic ELN (GaELNs) trained human gut Akkermansia muciniphila (A. muciniphila) can reverse high-fat diet-induced type 2 diabetes (T2DM) in mice. Oral administration of OMVs released from GaELNs trained A. muciniphila can traffick to the brain where they are taken up by microglial cells, resulting in inhibition of high-fat diet-induced brain inflammation. GaELNs treatment increases the levels of OMV Amuc-1100, P9, and phosphatidylcholines. Increasing the levels of Amuc-1100 and P9 leads to increasing the GLP-1 plasma level. Increasing the levels of phosphatidylcholines is required for inhibition of cGas and STING-mediated inflammation and GLP-1R crosstalk with the insulin pathway that leads to increasing expression of Insulin Receptor Substrate (IRS1 and IRS2) on OMV targeted cells. These findings reveal a molecular mechanism whereby OMVs from plant nanoparticle-trained gut bacteria regulate genes expressed in the brain, and have implications for the treatment of brain dysfunction caused by a metabolic syndrome.

Application of exosomes in tumor immunity: recent progresses

Exosomes are small extracellular vesicles secreted by cells, ranging in size from 30 to 150 nm. They contain proteins, nucleic acids, lipids, and other bioactive molecules, which play a crucial role in intercellular communication and material transfer. In tumor immunity, exosomes present various functions while the following two are of great importance: regulating the immune response and serving as delivery carriers. This review starts with the introduction of the formation, compositions, functions, isolation, characterization, and applications of exosomes, and subsequently discusses the current status of exosomes in tumor immunotherapy, and the recent applications of exosome-based tumor immunity regulation and antitumor drug delivery. Finally, current challenge and future prospects are proposed and hope to demonstrate inspiration for targeted readers in the field.