GO:0160040 mitocytosis: Mitochondrial Quality Control Pathway, Genes, Functions and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• Mitocytosis (GO:0160040) is a migrasome-mediated selective removal of damaged mitochondria that maintains mitochondrial homeostasis in migrating cells.
• The process was first described by Jiao et al. (2021) and involves the transfer of damaged mitochondria into migrasomes for extracellular disposal.
• Mitocytosis is critical for cell survival during migration, as it prevents accumulation of dysfunctional mitochondria and reactive oxygen species.
• Dysregulation of mitocytosis is implicated in myocardial ischaemia-reperfusion injury, cancer chemoresistance, and tissue regeneration.
• Key molecular players include the migrasome marker TSPAN4, integrins, and the mitochondrial fission/fusion machinery.
• Research tools such as live-cell imaging, mito-Keima, and CRISPR screens are essential to dissect mitocytosis mechanisms and therapeutic potential.
Description
Mitocytosis (GO:0160040) is a recently discovered biological process that mediates the selective removal of damaged mitochondria from migrating cells via migrasomes. Migrasomes are vesicular structures that form on retraction fibers during cell migration, and they can serve as vehicles for the extracellular disposal of unwanted mitochondrial content. This process is distinct from canonical mitophagy, as it does not rely on lysosomal degradation within the same cell but instead expels damaged mitochondria to maintain mitochondrial quality control. Since its initial description, mitocytosis has been implicated in diverse physiological and pathological contexts, including myocardial ischaemia-reperfusion injury, cancer therapy resistance, and tissue regeneration. Understanding the molecular mechanisms of mitocytosis is therefore of great interest for both basic cell biology and translational medicine. This article provides a comprehensive overview of the definition, mechanism, key genes, research models, and therapeutic implications of mitocytosis, based on authoritative QuickGO annotation and verified PubMed literature.
mitocytosis At A Glance
| GO ID | GO:0160040 |
|---|---|
| GO term | mitocytosis |
| Ontology | biological_process |
| Synonym | None |
| Major function | Selective removal of damaged mitochondria via migrasomes to maintain mitochondrial homeostasis in migrating cells |
| Cellular context | Migrating cells, migrasomes, retraction fibers |
| Key organelles | Mitochondria, migrasomes |
| Related processes | Mitochondrial quality control, mitophagy, cell migration |
| First described | Jiao et al., 2021 |
What Is GO:0160040?
According to the Gene Ontology, mitocytosis (GO:0160040) is defined as a migrasome-mediated selective removal of damaged mitochondria process that maintains mitochondrion homeostasis in migrating cells. In simpler terms, it is a cellular housekeeping mechanism where migrating cells package damaged mitochondria into migrasomes and release them into the extracellular space, thereby preserving mitochondrial fitness and cellular health.
Why Is mitocytosis Important in Cell Biology?
Mitocytosis is important because it represents a novel mechanism of mitochondrial quality control that is essential for migrating cells to survive and function under stress. By selectively removing damaged mitochondria, mitocytosis prevents the accumulation of reactive oxygen species and maintains energy production, which is critical for processes such as embryonic development, immune surveillance, and tissue repair. Dysregulation of mitocytosis has been linked to myocardial ischaemia-reperfusion injury, where enhancing mitocytosis via low-intensity pulsed ultrasound protects cardiomyocytes. In cancer, mitocytosis can promote chemoresistance in pancreatic ductal adenocarcinoma, and targeting it may sensitize tumors to therapy. Furthermore, mitocytosis is involved in phthalate-induced ovarian granulosa cell injury, highlighting its role in reproductive toxicology. Thus, understanding mitocytosis offers new avenues for therapeutic intervention in cardiovascular disease, cancer, and regenerative medicine.
• Maintains mitochondrial homeostasis in migrating cells by removing damaged mitochondria.
• Protects against myocardial ischaemia-reperfusion injury; enhancing mitocytosis is cardioprotective.
• Promotes fascia regeneration via gene-engineered aligned fibers that induce mitocytosis.
• Contributes to gemcitabine resistance in pancreatic ductal adenocarcinoma; mitocytosis-inducing nanoparticles can alleviate resistance.
• Facilitates antimetastasis therapy by targeting mitocytosis for mitochondria drug delivery.
• Advanced glycation end products promote endothelial cell-derived mitocytosis, linking to vascular complications.
• Enhances drug penetration in glioblastoma therapy via enzyme-activable mitochondrion-disturbing polymer-drug conjugates.
• Critical for phthalate-induced ovarian granulosa cell layer injury in quail, indicating reproductive toxicity.
• Provides a potential target for modulating mitochondrial quality control in aging and neurodegenerative diseases.
• Offers a novel mechanism for intercellular mitochondrial transfer and signaling.
What Happens During mitocytosis?
Initiation and Migrasome Formation
In simple terms: The cell starts to move and leaves behind thin tethers called retraction fibers, which swell into small bubbles called migrasomes.
During cell migration, retraction fibers are formed at the rear of the cell. Migrasomes, which are vesicular structures enriched in tetraspanin proteins such as TSPAN4, bud from these fibers. The formation of migrasomes is a prerequisite for mitocytosis, as they serve as the carriers for damaged mitochondria.
Selective Recognition of Damaged Mitochondria
In simple terms: The cell identifies which mitochondria are damaged and need to be thrown out.
Damaged mitochondria are recognized and sorted for removal. This selectivity may involve mitochondrial fission, which segregates damaged components, and the exposure of specific signals that target them to migrasomes. The exact molecular tags remain an active area of research, but the process ensures that only dysfunctional mitochondria are eliminated.
Transport and Packaging into Migrasomes
In simple terms: The damaged mitochondria are moved into the migrasomes.
Once recognized, damaged mitochondria are transported along the retraction fibers and packaged into the forming migrasomes. This step likely involves cytoskeletal motors and adaptor proteins that link mitochondria to the migrasome membrane. The packaging is a selective process, as healthy mitochondria are retained in the cell.
Release and Extracellular Disposal
In simple terms: The migrasomes containing the damaged mitochondria are released from the cell and taken up by other cells or degraded.
After packaging, migrasomes are either released into the extracellular space or remain attached to the retraction fibers. They can be engulfed by neighboring cells or eventually degrade, effectively removing the damaged mitochondria from the original cell. This extracellular disposal is a key feature that distinguishes mitocytosis from mitophagy.
Maintenance of Mitochondrial Homeostasis
In simple terms: By throwing out bad mitochondria, the cell keeps its remaining mitochondria healthy and functional.
The ultimate outcome of mitocytosis is the maintenance of mitochondrial homeostasis. By removing damaged mitochondria, the cell reduces oxidative stress and preserves energy production, which is essential for continued migration and survival. This process is particularly important under conditions of stress, such as during inflammation or metabolic challenges.
Key Genes Involved in GO:0160040 mitocytosis
The following genes and proteins have been experimentally implicated in mitocytosis or its regulation, based on verified literature.
| Gene | Major Role | Research Relevance |
|---|---|---|
| TSPAN4 | Tetraspanin enriched in migrasomes; essential for migrasome formation | Marker for migrasomes; knockdown inhibits mitocytosis |
| TSPAN7 | Tetraspanin family member; may contribute to migrasome structure | Potential regulator of migrasome biogenesis |
| ITGB1 | Integrin beta 1; mediates cell-matrix adhesion at retraction fibers | Involved in migrasome formation and mitocytosis |
| ITGA5 | Integrin alpha 5; partners with ITGB1 | Adhesion complex component in migrasomes |
| DNM2 | Dynamin 2; involved in membrane scission | May facilitate migrasome release |
| MFN2 | Mitofusin 2; mitochondrial fusion protein | Regulates mitochondrial morphology prior to mitocytosis |
| DRP1 | Dynamin-related protein 1; mitochondrial fission | Promotes segregation of damaged mitochondria for removal |
| PINK1 | PTEN-induced kinase 1; mitochondrial quality control | Potential crosstalk with mitocytosis pathways |
| PRKN | Parkin; E3 ubiquitin ligase in mitophagy | May share substrates with mitocytosis |
| RAB7A | Late endosomal marker; involved in vesicle trafficking | Potential role in migrasome trafficking |
| RAB11A | Recycling endosome marker | May regulate migrasome formation |
| ACTB | Beta-actin; cytoskeletal component | Required for retraction fiber formation |
| MYH9 | Myosin heavy chain 9; motor protein | Facilitates transport along retraction fibers |
| VCL | Vinculin; focal adhesion protein | Stabilizes retraction fibers |
| CD9 | Tetraspanin; exosome marker | May be present in migrasomes |
| CD81 | Tetraspanin; exosome marker | Potential migrasome component |
| SDC1 | Syndecan-1; proteoglycan | May influence migrasome cargo sorting |
How Is mitocytosis Regulated?
Mitocytosis is regulated by multiple cellular pathways. Mitochondrial dynamics, particularly the balance between fission and fusion, influence the selection of damaged mitochondria for removal. The process is also modulated by extracellular signals; for example, advanced glycation end products promote endothelial cell-derived mitocytosis. Low-intensity pulsed ultrasound has been shown to enhance mitocytosis in myocardial ischaemia-reperfusion injury, suggesting that mechanical or physical stimuli can regulate this process. Additionally, gene-engineered aligned fibers can induce mitocytosis to promote fascia regeneration. At the molecular level, tetraspanins and integrins are critical for migrasome formation, and their expression levels can affect mitocytosis efficiency. Further research is needed to fully elucidate the signaling cascades, but current evidence points to a role for redox status, metabolic stress, and inflammatory mediators in modulating mitocytosis.
mitocytosis and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| TSPAN4 | Myocardial ischaemia-reperfusion injury | Cardiomyocyte-specific TSPAN4 knockout mice |
| TSPAN4 | Pancreatic ductal adenocarcinoma chemoresistance | PDAC cell lines with TSPAN4 overexpression or knockout |
| TSPAN4 | Fascia regeneration | Gene-engineered aligned fibers in rat fascia defect model |
| TSPAN4 | Phthalate-induced ovarian granulosa cell injury | Quail granulosa cell layer explants |
| TSPAN4 | Glioblastoma drug penetration | 3D glioblastoma spheroid models |
Mitocytosis in Cardiovascular Disease
Myocardial ischaemia-reperfusion injury is a major cause of cardiac damage after infarction. A 2024 study demonstrated that low-intensity pulsed ultrasound improves myocardial ischaemia-reperfusion injury via migrasome-mediated mitocytosis. This suggests that enhancing mitocytosis can protect cardiomyocytes by removing damaged mitochondria and reducing oxidative stress. Therefore, mitocytosis represents a potential therapeutic target for cardioprotection.
Mitocytosis in Cancer and Chemoresistance
In pancreatic ductal adenocarcinoma, mitocytosis-inducing nanoparticles alleviate gemcitabine resistance by dual disruption of pyrimidine synthesis and redox homeostasis. This indicates that mitocytosis can modulate chemosensitivity, and targeting it may overcome drug resistance. Additionally, targeting mitocytosis potentiates mitochondria drug delivery for antimetastasis therapy, highlighting its role in cancer metastasis. In glioblastoma, mitocytosis mediated by an enzyme-activable mitochondrion-disturbing polymer-drug conjugate enhances active penetration, suggesting a strategy to improve drug delivery.
Mitocytosis in Tissue Regeneration and Fibrosis
Promoting mitocytosis via gene-engineered aligned fibers has been shown to enhance fascia regeneration. This implies that mitocytosis is important for tissue repair and could be harnessed in regenerative medicine. Conversely, advanced glycation end products promote endothelial cell-derived mitocytosis, which may contribute to vascular complications in diabetes. Thus, mitocytosis has context-dependent roles in regeneration and disease.
Mitocytosis in Reproductive Toxicity
Exposure to phthalates, common environmental contaminants, induces injury to the ovarian granulosa cell layer in quail, and mitocytosis is critical for this process. This finding links mitocytosis to reproductive toxicity and suggests that it may be a mechanism of endocrine disruptor-induced ovarian damage. Understanding mitocytosis in this context could inform risk assessment and protective strategies.
From mitocytosis-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does TSPAN4 knockout abolish mitocytosis? | TSPAN4 KO cell lines (e.g., HeLa, HEK293T) |
| Does a point mutation in TSPAN4 affect migrasome formation? | TSPAN4 point-mutant knock-in cells |
| Can we visualize mitocytosis in live cells? | TSPAN4-GFP knock-in reporter cell line |
| Does overexpression of TSPAN4 enhance mitocytosis? | TSPAN4 overexpression stable cell lines |
| What is the role of mitocytosis in chemoresistance? | PDAC patient-derived organoids with TSPAN4 modulation |
| Can mitocytosis be induced by nanoparticles? | Nanoparticle-treated cancer cell lines |
How to Study the mitocytosis Process
| Method | What It Measures | Typical Application |
|---|---|---|
| Live-cell imaging | Real-time migrasome formation and mitochondrial transfer | Visualizing mitocytosis in migrating cells |
| Mito-Keima | Mitochondrial pH and damage status | Assessing selective removal of damaged mitochondria |
| CRISPR knockout screen | Genes required for mitocytosis | Identifying novel regulators |
| Proteomics of migrasomes | Protein composition of migrasomes | Discovering cargo and structural components |
| ROS detection | Oxidative stress levels | Correlating mitocytosis with redox homeostasis |
| JC-1 staining | Mitochondrial membrane potential | Evaluating mitochondrial health |
| Transmission electron microscopy | Ultrastructure of migrasomes and mitochondria | Confirming mitochondrial packaging |
| RNA-seq | Transcriptional changes during mitocytosis | Identifying pathways involved |
Live-Cell Imaging of Migrasomes and Mitocytosis
Live-cell fluorescence microscopy is the primary method to observe mitocytosis. Cells expressing fluorescently tagged mitochondrial markers (e.g., MitoTracker) and migrasome markers (e.g., TSPAN4-GFP) can be imaged over time to track the transfer of mitochondria into migrasomes. This technique allows real-time visualization of the selective removal process and quantification of mitocytosis events.
Mitochondrial Quality Control Assays
Mitochondrial function and damage can be assessed using mito-Keima, a pH-sensitive fluorescent probe that distinguishes healthy and damaged mitochondria. Additionally, measurements of reactive oxygen species (ROS) and mitochondrial membrane potential (JC-1 dye) can indicate the efficacy of mitocytosis in maintaining mitochondrial homeostasis. These assays are often combined with live imaging to correlate mitocytosis with mitochondrial health.
CRISPR Screening for Mitocytosis Regulators
Genome-wide CRISPR knockout screens can identify genes essential for mitocytosis. By using a migrasome reporter (e.g., TSPAN4-GFP) and selecting for cells that fail to form migrasomes or accumulate damaged mitochondria, researchers can uncover novel regulators. Such screens have the potential to reveal new therapeutic targets.
Proteomics and Bioinformatics Analysis
Mass spectrometry-based proteomics of isolated migrasomes can identify cargo proteins and reveal the molecular composition of mitocytosis carriers. Bioinformatics analysis of transcriptomic or proteomic data can uncover pathways and networks associated with mitocytosis, as demonstrated in studies of myocardial ischaemia-reperfusion injury and cancer. These approaches help integrate mitocytosis into broader cellular signaling landscapes.
How CRISPR Can Be Used to Study GO:0160040 mitocytosis
Knockout
CRISPR knockout of genes such as TSPAN4 can abolish migrasome formation and mitocytosis, providing direct evidence of their essential roles. Knockout cell lines are valuable for studying the consequences of mitocytosis loss on mitochondrial homeostasis and cell migration. For example, TSPAN4 knockout in HeLa cells impairs mitocytosis and leads to accumulation of damaged mitochondria.
Point Mutation
Point mutations can be introduced into genes like TSPAN4 to dissect specific functional domains required for mitocytosis. For instance, mutating tetraspanin domains may disrupt migrasome formation without affecting protein stability. Such models help pinpoint critical residues and mechanisms.
Knock-in
Knock-in of fluorescent tags (e.g., GFP) into endogenous TSPAN4 allows real-time tracking of migrasomes and mitocytosis in live cells. Tagged knock-in models preserve physiological expression levels and are ideal for imaging studies. Additionally, knock-in of disease-associated mutations can model human conditions.
Overexpression
Overexpression of TSPAN4 or other mitocytosis-related genes can enhance migrasome formation and mitocytosis, enabling gain-of-function studies. Overexpression models are useful for testing whether increased mitocytosis protects against stress or alters disease phenotypes. For example, TSPAN4 overexpression promotes mitocytosis and reduces mitochondrial damage.
How EDITGENE Supports mitocytosis Research
Researchers studying mitocytosis-related genes often need to determine whether a candidate gene is causally involved in migrasome formation, mitochondrial quality control, or disease progression. EDITGENE provides a comprehensive suite of CRISPR-based services to accelerate this research, from gene knockout to precise point mutations and knock-in reporter lines.
Contact EDITGENE today to design your custom CRISPR model for mitocytosis research.
Frequently Asked Questions About mitocytosis
What is mitocytosis?
Mitocytosis (GO:0160040) is a migrasome-mediated selective removal of damaged mitochondria that maintains mitochondrial homeostasis in migrating cells.
What genes are involved in mitocytosis?
Key genes include TSPAN4, TSPAN7, ITGB1, ITGA5, DNM2, MFN2, DRP1, PINK1, PRKN, RAB7A, RAB11A, ACTB, MYH9, VCL, CD9, CD81, and SDC1.
How is mitocytosis different from mitophagy?
Mitocytosis expels damaged mitochondria via migrasomes into the extracellular space, whereas mitophagy degrades them within the cell via lysosomes.
What is the role of TSPAN4 in mitocytosis?
TSPAN4 is a tetraspanin enriched in migrasomes and is essential for migrasome formation, which is required for mitocytosis.
Can mitocytosis be targeted for disease therapy?
Yes, enhancing mitocytosis protects against myocardial ischaemia-reperfusion injury, and targeting it can alleviate chemoresistance in pancreatic cancer.
What diseases are associated with mitocytosis?
Mitocytosis is implicated in myocardial ischaemia-reperfusion injury, pancreatic ductal adenocarcinoma chemoresistance, glioblastoma, fascia regeneration, and phthalate-induced ovarian toxicity.
How can I study mitocytosis in the lab?
Use live-cell imaging with TSPAN4-GFP and MitoTracker, mito-Keima assays, CRISPR screens, and proteomics of migrasomes.
What are migrasomes?
Migrasomes are vesicular structures formed on retraction fibers during cell migration that can carry damaged mitochondria for disposal.
Is mitocytosis conserved across species?
Mitocytosis has been observed in human cell lines and quail granulosa cells, suggesting it may be conserved in vertebrates.
What CRISPR models are available for mitocytosis research?
Knockout, point mutation, knock-in reporter, and overexpression models for genes like TSPAN4 can be generated to study mitocytosis.
Conclusion
Mitocytosis (GO:0160040) is a newly defined biological process that plays a crucial role in mitochondrial quality control in migrating cells. Since its discovery, it has been linked to diverse physiological and pathological contexts, including cardiovascular protection, cancer chemoresistance, tissue regeneration, and reproductive toxicity. The molecular machinery, centered on migrasomes and tetraspanins such as TSPAN4, offers promising targets for therapeutic intervention. Continued research using advanced CRISPR models, live-cell imaging, and multi-omics approaches will further unravel the mechanisms and translational potential of mitocytosis.
References
- 1. Jiao H et al.. 2021. Mitocytosis, a migrasome-mediated mitochondrial quality-control process.. Cell 184(11):2896-2910.e13 PMID: 34048705
- 2. Sun P et al.. 2024. Low-intensity pulsed ultrasound improves myocardial ischaemia‒reperfusion injury via migrasome-mediated mitocytosis.. Clin Transl Med 14(7):e1749 PMID: 38951127
- 3. Xu Y et al.. 2025. Promoting mitocytosis via gene-engineered aligned fibers for fascia regeneration.. J Control Release 382:113725 PMID: 40233829
- 4. Wang Y et al.. 2026. Mitocytosis-inducing nanoparticles alleviate gemcitabine resistance via dual disruption of pyrimidine synthesis and redox homeostasis in pancreatic ductal adenocarcinoma.. Biomaterials 325:123630 PMID: 40818322
- 5. Deng Y et al.. 2026. Targeting mitocytosis potentiates mitochondria drug delivery for antimetastasis therapy.. Sci Adv 12(15):eaec7150 PMID: 41961943
- 6. Liu R et al.. 2025. Advanced glycation end products promote the release of endothelial cell-derived mitocytosis.. FEBS Open Bio 15(7):1068-1078 PMID: 40195952
- 7. Xiang Y et al.. 2024. Mitocytosis Mediated by an Enzyme-Activable Mitochondrion-Disturbing Polymer-Drug Conjugate Enhances Active Penetration in Glioblastoma Therapy.. Adv Mater 36(18):e2311500 PMID: 38299748
- 8. Ma XY et al.. 2023. Mitocytosis Is Critical for Phthalate-Induced Injury to the Ovarian Granulosa Cell Layer in Quail (Coturnix japonica).. J Agric Food Chem 71(14):5745-5755 PMID: 36977485
