Cell-to-cell communication is a fundamental process in every multicellular organism. In addition to membrane-bound and released factors, the sharing of cytosolic components represents a new, poorly explored signaling route. An extraordinary example of this communication channel is the direct transport of mitochondria between cells. In this review, we discuss how intercellular mitochondrial transfer can be used by cancer cells to sustain their high metabolic requirements and promote drug resistance and describe relevant molecular players in the context of current and future cancer therapy.

• Klíčová slova
• cancer, mitochondria, mitochondrial transfer, tumor microenvironment, tunneling nanotubes,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

• Klíčová slova
• cell-to-cell communication, exosomes, intercellular transfer, neurodegenerative aggregates, tunneling nanotubes,
• Publikační typ
• úvodníky MeSH

Mitochondria are organelles present in most eukaryotic cells, where they play major and multifaceted roles. The classical notion of the main mitochondrial function as the powerhouse of the cell per se has been complemented by recent discoveries pointing to mitochondria as organelles affecting a number of other auxiliary processes. They go beyond the classical energy provision via acting as a relay point of many catabolic and anabolic processes, to signaling pathways critically affecting cell growth by their implication in de novo pyrimidine synthesis. These additional roles further underscore the importance of mitochondrial homeostasis in various tissues, where its deregulation promotes a number of pathologies. While it has long been known that mitochondria can move within a cell to sites where they are needed, recent research has uncovered that mitochondria can also move between cells. While this intriguing field of research is only emerging, it is clear that mobilization of mitochondria requires a complex apparatus that critically involves mitochondrial proteins of the Miro family, whose role goes beyond the mitochondrial transfer, as will be covered in this review.

• Klíčová slova
• Miro proteins, Mitochondria, endoplasmic reticulum, intercellular transfer, mitophagy, motor proteins, respiration,
• MeSH
• aktivní transport fyziologie   MeSH
• lidé MeSH
• mitochondriální proteiny genetika   metabolismus   MeSH
• mitochondrie genetika   metabolismus   MeSH
• pyrimidiny biosyntéza   MeSH
• rho proteiny vázající GTP genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• audiovizuální média MeSH
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• mitochondriální proteiny MeSH
• pyrimidine MeSH Prohlížeč
• pyrimidiny MeSH
• rho proteiny vázající GTP MeSH

Mitochondria are organelles essential for tumor cell proliferation and metastasis. Although their main cellular function, generation of energy in the form of ATP is dispensable for cancer cells, their capability to drive their adaptation to stress originating from tumor microenvironment makes them a plausible therapeutic target. Recent research has revealed that cancer cells with damaged oxidative phosphorylation import healthy (functional) mitochondria from surrounding stromal cells to drive pyrimidine synthesis and cell proliferation. Furthermore, it has been shown that energetically competent mitochondria are fundamental for tumor cell migration, invasion and metastasis. The spatial positioning and transport of mitochondria involves Miro proteins from a subfamily of small GTPases, localized in outer mitochondrial membrane. Miro proteins are involved in the structure of the MICOS complex, connecting outer and inner-mitochondrial membrane; in mitochondria-ER communication; Ca2+ metabolism; and in the recycling of damaged organelles via mitophagy. The most important role of Miro is regulation of mitochondrial movement and distribution within (and between) cells, acting as an adaptor linking organelles to cytoskeleton-associated motor proteins. In this review, we discuss the function of Miro proteins in various modes of intercellular mitochondrial transfer, emphasizing the structure and dynamics of tunneling nanotubes, the most common transfer modality. We summarize the evidence for and propose possible roles of Miro proteins in nanotube-mediated transfer as well as in cancer cell migration and metastasis, both processes being tightly connected to cytoskeleton-driven mitochondrial movement and positioning.

• Klíčová slova
• Miro, cancer, intercellular transfer, metastasis, migration, mitochondria, respiration,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Current dogma holds that genes are the property of individual mammalian cells and partition between daughter cells during cell division. However, and rather unexpectedly, recent research has demonstrated horizontal cell-to-cell transfer of mitochondria and mitochondrial DNA in several mammalian cell culture systems. Furthermore, unequivocal evidence that mitochondrial DNA transfer occurs in vivo has now been published. While these studies show horizontal transfer of mitochondrial DNA in pathological settings, it is also possible that intercellular mitochondrial transfer is a fundamental physiological process with a role in development and tissue homeostasis.

• MeSH
• buněčné dělení genetika   MeSH
• lidé MeSH
• mezibuněčná komunikace genetika   MeSH
• mitochondriální DNA genetika   MeSH
• mitochondrie genetika   MeSH
• přenos genů horizontální genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• mitochondriální DNA MeSH

I explored the effect of genetic (cloning) and non-genetic (arrangement of the method and quality of culture serum) factors upon variability of the results obtained by using the "kiss of death" method for evaluation of intercellular communication in Chinese hamster cells V79-4. Cloning had neither quantitative (intraspecies communication) nor qualitative (interspecies communication) effects. Of the non-genetic factors, the time interval of application of transferred agent (thioguanine) after plating the cells and the agent concentration were investigated. These factors did not influence significantly the results. Intercellular communication was more intensive in a less rich medium containing bovine serum than in a richer medium containing foetal calf serum. On the basis of the results obtained I conclude that the higher variability of intercellular communication values determined by the "kiss of death" method is not due to an error in the experimental method used but probably reflects the real changes in these values that occur with time in cell populations.

• MeSH
• buněčné klony MeSH
• buněčné linie MeSH
• F faktor MeSH
• krev MeSH
• mezibuněčná komunikace * MeSH
• mezibuněčné spoje fyziologie   MeSH
• thioguanin farmakologie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• thioguanin MeSH

The scrape loading/dye transfer (SL/DT) technique is a simple functional assay for the simultaneous assessment of gap junctional intercellular communication (GJIC) in a large population of cells. The equipment needs are minimal and are typically met in standard cell biology labs, and SL/DT is the simplest and quickest of all the assays that measure GJIC. This assay has also been adapted for in vivo studies. The SL/DT assay is also conducive to a high-throughput setup with automated fluorescence microscopy imaging and analysis to elucidate more samples in shorter time, and hence can serve a broad range of in vitro pharmacological and toxicological needs.

• Klíčová slova
• Dye coupling, Dye transfer, Ex vivo assessment, Gap junctional intercellular communication assessment, High throughput, In vitro assay, Incision loading, Lucifer Yellow, Scalpel loading, Scrape loading, Tracers,
• MeSH
• dextrany metabolismus   MeSH
• fluorescenční barviva metabolismus   MeSH
• fluorescenční mikroskopie metody   MeSH
• isochinoliny metabolismus   MeSH
• kultivované buňky MeSH
• mezerový spoj metabolismus   ultrastruktura   MeSH
• mezibuněčná komunikace * MeSH
• myši MeSH
• rhodaminy metabolismus   MeSH
• Sertoliho buňky MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• dextrany MeSH
• fluorescenční barviva MeSH
• isochinoliny MeSH
• lucifer yellow MeSH Prohlížeč
• rhodamine dextran MeSH Prohlížeč
• rhodaminy MeSH

The view that genes are constrained within somatic cells is challenged by in vitro evidence, and more recently by in vivo studies which demonstrate that mitochondria with their mitochondrial DNA (mtDNA) payload not only can, but do move between cells in tumour models and in mouse models of tissue damage. Using mouse tumour cell models without mtDNA to reflect mtDNA damage, we have shown that these cells grow tumours only after acquiring mtDNA from cells in the local microenvironment resulting in respiration recovery, tumorigenesis and metastasis. Mitochondrial transfer between cells has also been demonstrated following ischaemia-induced injury in the heart and brain and in lung epithelium, and following lung inflammation. In vitro investigations suggest that stem cells may be mitochondrial donors. The ability of mitochondria to move between cells appears to be an evolutionarily-conserved phenomenon, relevant to diseases with compromised mitochondrial function including neurodegenerative, neuromuscular and cardiovascular diseases as well as cancer and ageing.

• Klíčová slova
• bioenergetics, cancer, disease, intercellular mitochondrial trafficking, mitochondria, mitochondrial DNA damage, rho zero cells,
• MeSH
• biogeneze organel MeSH
• lidé MeSH
• mitochondriální DNA genetika   metabolismus   MeSH
• mitochondrie genetika   metabolismus   patologie   MeSH
• nádorové mikroprostředí MeSH
• nádory genetika   metabolismus   patologie   MeSH
• pohyb buněk * MeSH
• poškození DNA MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• mitochondriální DNA MeSH

Gap junctional intercellular communication (GJIC) is a vital cellular process required for maintenance of tissue homeostasis. In vitro assessment of GJIC represents valuable phenotypic endpoint that could be effectively utilized as an integral component in modern toxicity testing, drug screening or biomedical in vitro research. However, currently available methods for quantifying GJIC with higher-throughputs typically require specialized equipment, proprietary software and/or genetically engineered cell models. To overcome these limitations, we present here an innovative adaptation of traditional, fluorescence microscopy-based scrape loading-dye transfer (SL-DT) assay, which has been optimized to simultaneously evaluate GJIC, cell density and viability. This multiparametric method was demonstrated to be suitable for various multiwell microplate formats, which facilitates an automatized image acquisition. The assay workflow is further assisted by an open source-based software tools for batch image processing, analysis and evaluation of GJIC, cell density and viability. Our results suggest that this approach provides a simple, fast, versatile and cost effective way for in vitro high-throughput assessment of GJIC and other related phenotypic cellular events, which could be included into in vitro screening and assessment of pharmacologically and toxicologically relevant compounds.

• MeSH
• fluorescenční mikroskopie metody   MeSH
• krysa rodu Rattus MeSH
• kultivované buňky MeSH
• mezerový spoj * MeSH
• mezibuněčná komunikace * MeSH
• molekulární zobrazování metody   MeSH
• počet buněk * MeSH
• počítačové zpracování obrazu metody   MeSH
• viabilita buněk * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Dysregulation of gap junction intercellular communication (GJIC) is recognized as one of the key hallmarks for identifying non-genotoxic carcinogens (NGTxC). Currently, there is a demand for in vitro assays addressing the gap junction hallmark, which would have the potential to eventually become an integral part of an integrated approach to the testing and assessment (IATA) of NGTxC. The scrape loading-dye transfer (SL-DT) technique is a simple assay for the functional evaluation of GJIC in various in vitro cultured mammalian cells and represents an interesting candidate assay. Out of the various techniques for evaluating GJIC, the SL-DT assay has been used frequently to assess the effects of various chemicals on GJIC in toxicological and tumor promotion research. In this review, we systematically searched the existing literature to gather papers assessing GJIC using the SL-DT assay in a rat liver epithelial cell line, WB-F344, after treating with chemicals, especially environmental and food toxicants, drugs, reproductive-, cardio- and neuro-toxicants and chemical tumor promoters. We discuss findings derived from the SL-DT assay with the known knowledge about the tumor-promoting activity and carcinogenicity of the assessed chemicals to evaluate the predictive capacity of the SL-DT assay in terms of its sensitivity, specificity and accuracy for identifying carcinogens. These data represent important information with respect to the applicability of the SL-DT assay for the testing of NGTxC within the IATA framework.

• Klíčová slova
• carcinogenesis, carcinogens, gap junction intercellular communication, scrape loading-dye transfer,
• MeSH
• barvicí látky metabolismus   MeSH
• biotest metody   MeSH
• buněčné linie MeSH
• fluorescenční mikroskopie metody   MeSH
• játra patologie   MeSH
• karcinogeny MeSH
• krysa rodu Rattus MeSH
• kultivované buňky MeSH
• mezerový spoj metabolismus   MeSH
• mezibuněčná komunikace účinky léků   fyziologie   MeSH
• testy karcinogenity metody   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• barvicí látky MeSH
• karcinogeny MeSH