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Belashov AV, Zhikhoreva AA, Salova AV, Belyaeva TN, Litvinov IK, Kornilova ES, Semenova IV, Vasyutinskii OS. Automatic segmentation of lysosomes and analysis of intracellular pH with Radachlorin photosensitizer and FLIM. Biochem Biophys Res Commun 2024; 710:149835. [PMID: 38574457 DOI: 10.1016/j.bbrc.2024.149835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/17/2024] [Accepted: 03/25/2024] [Indexed: 04/06/2024]
Abstract
We report application of the fluorescence lifetime imaging microscopy (FLIM) for analysis of distributions of intracellular acidity using a chlorin-e6 based photosensitizer Radachlorin. An almost two-fold increase of the photosensitizer fluorescence lifetime in alkaline microenvironments as compared to acidic ones allowed for clear distinguishing between acidic and alkaline intracellular structures. Clusterization of a phasor plot calculated from fits of the FLIM raw data by two Gaussian distributions provided accurate automatic segmentation of lysosomes featuring acidic contents. The approach was validated in colocalization experiments with LysoTracker fluorescence in living cells of four established lines. The dependence of photosensitizer fluorescence lifetime on microenvironment acidity allowed for estimation of pH inside the cells, except for the nuclei, where photosensitizer does not penetrate. The developed method is promising for combined application of the photosensitizer for both photodynamic treatment and diagnostics.
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Affiliation(s)
- A V Belashov
- Ioffe Institute, Russian Academy of Sciences, 26, Polytekhnicheskaya, St.Petersburg, 194021, Russia
| | - A A Zhikhoreva
- Ioffe Institute, Russian Academy of Sciences, 26, Polytekhnicheskaya, St.Petersburg, 194021, Russia
| | - A V Salova
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Pr., 4, St. Petersburg, 194064, Russia
| | - T N Belyaeva
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Pr., 4, St. Petersburg, 194064, Russia
| | - I K Litvinov
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Pr., 4, St. Petersburg, 194064, Russia
| | - E S Kornilova
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky Pr., 4, St. Petersburg, 194064, Russia
| | - I V Semenova
- Ioffe Institute, Russian Academy of Sciences, 26, Polytekhnicheskaya, St.Petersburg, 194021, Russia.
| | - O S Vasyutinskii
- Ioffe Institute, Russian Academy of Sciences, 26, Polytekhnicheskaya, St.Petersburg, 194021, Russia
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2
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Tirumala NA, Redpath GMI, Skerhut SV, Dolai P, Kapoor-Kaushik N, Ariotti N, Vijay Kumar K, Ananthanarayanan V. Single-molecule imaging of stochastic interactions that drive dynein activation and cargo movement in cells. J Cell Biol 2024; 223:e202210026. [PMID: 38240798 PMCID: PMC10798859 DOI: 10.1083/jcb.202210026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 07/10/2023] [Accepted: 12/13/2023] [Indexed: 01/22/2024] Open
Abstract
Cytoplasmic dynein 1 (dynein) is the primary minus end-directed motor protein in most eukaryotic cells. Dynein remains in an inactive conformation until the formation of a tripartite complex comprising dynein, its regulator dynactin, and a cargo adaptor. How this process of dynein activation occurs is unclear since it entails the formation of a three-protein complex inside the crowded environs of a cell. Here, we employed live-cell, single-molecule imaging to visualize and track fluorescently tagged dynein. First, we observed that only ∼30% of dynein molecules that bound to the microtubule (MT) engaged in minus end-directed movement, and that too for a short duration of ∼0.6 s. Next, using high-resolution imaging in live and fixed cells and using correlative light and electron microscopy, we discovered that dynactin and endosomal cargo remained in proximity to each other and to MTs. We then employed two-color imaging to visualize cargo movement effected by single motor binding. Finally, we performed long-term imaging to show that short movements are sufficient to drive cargo to the perinuclear region of the cell. Taken together, we discovered a search mechanism that is facilitated by dynein's frequent MT binding-unbinding kinetics: (i) in a futile event when dynein does not encounter cargo anchored in proximity to the MT, dynein dissociates and diffuses into the cytoplasm, (ii) when dynein encounters cargo and dynactin upon MT binding, it moves cargo in a short run. Several of these short runs are undertaken in succession for long-range directed movement. In conclusion, we demonstrate that dynein activation and cargo capture are coupled in a step that relies on the reduction of dimensionality to enable minus end-directed transport in cellulo and that complex cargo behavior emerges from stochastic motor-cargo interactions.
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Affiliation(s)
| | - Gregory Michael Ian Redpath
- EMBL Australia Node in Single Molecule Science, Department of Molecular MedicineSchool of Biomedical Sciences, University of New South Wales, Sydney, Australia
| | - Sarah Viktoria Skerhut
- EMBL Australia Node in Single Molecule Science, Department of Molecular MedicineSchool of Biomedical Sciences, University of New South Wales, Sydney, Australia
| | - Pritha Dolai
- International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Bengaluru, India
| | | | - Nicholas Ariotti
- Electron Microscopy Unit, University of New South Wales, Sydney, Australia
| | - K. Vijay Kumar
- International Centre for Theoretical Sciences, Tata Institute of Fundamental Research, Bengaluru, India
| | - Vaishnavi Ananthanarayanan
- EMBL Australia Node in Single Molecule Science, Department of Molecular MedicineSchool of Biomedical Sciences, University of New South Wales, Sydney, Australia
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Litvinov IK, Belyaeva TN, Salova AV, Aksenov ND, Chelushkin PS, Solomatina AI, Tunik SP, Kornilova ES. The Dual Luminescence Lifetime pH/Oxygen Sensor: Evaluation of Applicability for Intravital Analysis of 2D- and 3D-Cultivated Human Endometrial Mesenchymal Stromal Cells. Int J Mol Sci 2023; 24:15606. [PMID: 37958592 PMCID: PMC10650141 DOI: 10.3390/ijms242115606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 10/16/2023] [Accepted: 10/23/2023] [Indexed: 11/15/2023] Open
Abstract
The oxygenation of cells and tissues and acidification of the cellular endolysosomal system are among the major factors that ensure normal functioning of an organism and are violated in various pathologies. Recording of these parameters and their changes under various conditions is an important task for both basic research and clinical applications. In the present work, we utilized internalizable dual pH/O2 lifetime sensor (Ir-HSA-FITC) based on the covalent conjugation of human serum albumin (HSA) with fluorescein isothiocyanate (FITC) as pH sensor and an orthometalated iridium complex as O2 sensor. The probe was tested for simultaneous detection of acidification level and oxygen concentration in endolysosomes of endometrial mesenchymal stem/stromal cells (enMSCs) cultivated as 2D monolayers and 3D spheroids. Using a combined FLIM/PLIM approach, we found that due to high autofluorescence of enMSCs FITC lifetime signal in control cells was insufficient to estimate pH changes. However, using flow cytometry and confocal microscopy, we managed to detect the FITC signal response to inhibition of endolysosomal acidification by Bafilomycin A1. The iridium chromophore phosphorescence was detected reliably by all methods used. It was demonstrated that the sensor, accumulated in endolysosomes for 24 h, disappeared from proliferating 2D enMSCs by 72 h, but can still be recorded in non-proliferating spheroids. PLIM showed high sensitivity and responsiveness of iridium chromophore phosphorescence to experimental hypoxia both in 2D and 3D cultures. In spheroids, the phosphorescence signal was detected at a depth of up to 60 μm using PLIM and showed a gradient in the intracellular O2 level towards their center.
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Affiliation(s)
- Ilia K. Litvinov
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky av. 4, 194064 Saint-Petersburg, Russia; (I.K.L.); (T.N.B.); (A.V.S.); (N.D.A.)
| | - Tatiana N. Belyaeva
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky av. 4, 194064 Saint-Petersburg, Russia; (I.K.L.); (T.N.B.); (A.V.S.); (N.D.A.)
| | - Anna V. Salova
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky av. 4, 194064 Saint-Petersburg, Russia; (I.K.L.); (T.N.B.); (A.V.S.); (N.D.A.)
| | - Nikolay D. Aksenov
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky av. 4, 194064 Saint-Petersburg, Russia; (I.K.L.); (T.N.B.); (A.V.S.); (N.D.A.)
| | - Pavel S. Chelushkin
- Institute of Chemistry, St. Petersburg State University, Universitetskii av., 26, 198504 Saint-Petersburg, Russia; (P.S.C.); (A.I.S.)
| | - Anastasia I. Solomatina
- Institute of Chemistry, St. Petersburg State University, Universitetskii av., 26, 198504 Saint-Petersburg, Russia; (P.S.C.); (A.I.S.)
| | - Sergey P. Tunik
- Institute of Chemistry, St. Petersburg State University, Universitetskii av., 26, 198504 Saint-Petersburg, Russia; (P.S.C.); (A.I.S.)
| | - Elena S. Kornilova
- Institute of Cytology, Russian Academy of Sciences, Tikhoretsky av. 4, 194064 Saint-Petersburg, Russia; (I.K.L.); (T.N.B.); (A.V.S.); (N.D.A.)
- Higher School of Biomedical Systems and Technologies, Peter the Great St. Petersburg Polytechnic University, Khlopina Str. 11, 195251 Saint-Petersburg, Russia
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Litvinov I, Salova A, Aksenov N, Kornilova E, Belyaeva T. Microenvironmental Impact on InP/ZnS-Based Quantum Dots in In Vitro Models and in Living Cells: Spectrally- and Time-Resolved Luminescence Analysis. Int J Mol Sci 2023; 24:ijms24032699. [PMID: 36769021 PMCID: PMC9916881 DOI: 10.3390/ijms24032699] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 01/15/2023] [Accepted: 01/21/2023] [Indexed: 02/04/2023] Open
Abstract
Quantum dots (QDs) have attracted great attention as tools for theranostics that combine the possibility of simultaneous biological target visualization and medicine delivery. Here, we address whether core/shell InP/ZnS QDs (InP-QDs) may be an alternative to toxic Cd-based QDs. We analyze InP-QD photophysical characteristics in cell culture medium, salt solutions, and directly in the cells. It was demonstrated that InP-QDs were internalized into endolysosomes in HeLa and A549 cells with dynamics similar to Cd-based QDs of the same design, but the two cell lines accumulated them with different efficiencies. InP-QDs were reliably detected in the endosomes despite their low quantum yields. Cell culture medium efficiently decreased the InP-QD photoluminescence lifetime by 50%, acidic pH (4.0) had a moderate effect (20-25% reduction), and quenching by salt solutions typical of intra-endosomal medium composition resulted in a decrease of about 10-15%. The single-vesicle fluorescence-lifetime imaging microscopy analysis of QDs inside and outside the cells shows that the scatter between endosomes in the same cell can be significant, which indicates the complex impact of the abovementioned factors on the state of InP-QDs. The PI test and MTT test demonstrate that InP-QDs are toxic for both cell lines at concentrations higher than 20 nM. Possible reasons for InP-QD toxicity are discussed.
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Affiliation(s)
- Ilia Litvinov
- Institute of Cytology, Russian Academy of Sciences,194064 Saint Petersburg, Russia
| | - Anna Salova
- Institute of Cytology, Russian Academy of Sciences,194064 Saint Petersburg, Russia
| | - Nikolay Aksenov
- Institute of Cytology, Russian Academy of Sciences,194064 Saint Petersburg, Russia
| | - Elena Kornilova
- Institute of Cytology, Russian Academy of Sciences,194064 Saint Petersburg, Russia
- Higher School of Biomedical Systems and Technologies, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia
- Correspondence: ; Tel.: +7-921-302-59-05
| | - Tatiana Belyaeva
- Institute of Cytology, Russian Academy of Sciences,194064 Saint Petersburg, Russia
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Time- and Spectrally-Resolved Photoluminescence Study of Alloyed Cd xZn 1-xSe yS 1-y/ZnS Quantum Dots and Their Nanocomposites with SPIONs in Living Cells. Int J Mol Sci 2022; 23:ijms23074061. [PMID: 35409422 PMCID: PMC8999546 DOI: 10.3390/ijms23074061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 03/30/2022] [Accepted: 04/04/2022] [Indexed: 12/18/2022] Open
Abstract
Magnetic-luminescent composites based on semiconductor quantum dots (QDs) and superparamagnetic iron oxide nanoparticles (SPIONs) can serve as a platform combining visualization and therapy. Here, we report the construction of QD-SPION nanocomposites based on synthesized SPIONs and alloyed QDs (CdxZn1−xSeyS1−y)/ZnS solubilized with L-cysteine molecules. The study of the spectral-luminescence characteristics, the kinetics of luminescence decay show the composite’s stability in a solution. After incubation with HeLa cells, QDs, SPIONs, and their composites form clusters on the cell surface and associate with endosomes inside the cells. Component-wise analysis of the photoluminescence decay of cell-associated QDs/SPIONs provides information about their localization and aggregate status.
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Dobner J, Simons IM, Rufinatscha K, Hänsch S, Schwarten M, Weiergräber OH, Abdollahzadeh I, Gensch T, Bode JG, Hoffmann S, Willbold D. Deficiency of GABARAP but not its Paralogs Causes Enhanced EGF-induced EGFR Degradation. Cells 2020; 9:E1296. [PMID: 32456010 PMCID: PMC7291022 DOI: 10.3390/cells9051296] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 05/19/2020] [Accepted: 05/20/2020] [Indexed: 12/20/2022] Open
Abstract
The γ-aminobutyric acid type A receptor-associated protein (GABARAP) and its close paralogs GABARAPL1 and GABARAPL2 constitute a subfamily of the autophagy-related 8 (Atg8) protein family. Being associated with a variety of dynamic membranous structures of autophagic and non-autophagic origin, Atg8 proteins functionalize membranes by either serving as docking sites for other proteins or by acting as membrane tethers or adhesion factors. In this study, we describe that deficiency for GABARAP alone, but not for its close paralogs, is sufficient for accelerated EGF receptor (EGFR) degradation in response to EGF, which is accompanied by the downregulation of EGFR-mediated MAPK signaling, altered target gene expression, EGF uptake, and EGF vesicle composition over time. We further show that GABARAP and EGFR converge in the same distinct compartments at endogenous GABARAP expression levels in response to EGF stimulation. Furthermore, GABARAP associates with EGFR in living cells and binds to synthetic peptides that are derived from the EGFR cytoplasmic tail in vitro. Thus, our data strongly indicate a unique and novel role for GABARAP during EGFR trafficking.
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Affiliation(s)
- Jochen Dobner
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany; (J.D.); (I.M.S.)
| | - Indra M. Simons
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany; (J.D.); (I.M.S.)
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (M.S.); (O.H.W.); (I.A.); (S.H.)
| | - Kerstin Rufinatscha
- Department of Gastroenterology, Hepatology and Infectiology, University Hospital, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany; (K.R.); (J.G.B.)
| | - Sebastian Hänsch
- Department of Biology, Center for Advanced Imaging (CAi), Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany;
| | - Melanie Schwarten
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (M.S.); (O.H.W.); (I.A.); (S.H.)
| | - Oliver H. Weiergräber
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (M.S.); (O.H.W.); (I.A.); (S.H.)
| | - Iman Abdollahzadeh
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (M.S.); (O.H.W.); (I.A.); (S.H.)
- Institute of Biological Information Processing: Molecular and Cell Physiology (IBI-1), Forschungszentrum Jülich, 52425 Jülich, Germany;
| | - Thomas Gensch
- Institute of Biological Information Processing: Molecular and Cell Physiology (IBI-1), Forschungszentrum Jülich, 52425 Jülich, Germany;
| | - Johannes G. Bode
- Department of Gastroenterology, Hepatology and Infectiology, University Hospital, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany; (K.R.); (J.G.B.)
| | - Silke Hoffmann
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (M.S.); (O.H.W.); (I.A.); (S.H.)
| | - Dieter Willbold
- Institut für Physikalische Biologie, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany; (J.D.); (I.M.S.)
- Institute of Biological Information Processing: Structural Biochemistry (IBI-7), Forschungszentrum Jülich, 52425 Jülich, Germany; (M.S.); (O.H.W.); (I.A.); (S.H.)
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Yang KH, Kim GT, Choi S, Yoon SY, Kim JW. 1‑Palmitoyl‑2‑linoleoyl‑3‑acetyl‑rac‑glycerol ameliorates EGF‑induced MMP‑9 expression by promoting receptor desensitization in MDA‑MB‑231 cells. Oncol Rep 2020; 44:241-251. [PMID: 32377695 PMCID: PMC7254954 DOI: 10.3892/or.2020.7599] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 04/08/2020] [Indexed: 12/12/2022] Open
Abstract
Activated epidermal growth factor receptors (EGFRs) are crucial for inducing metastasis in cancer cells by promoting matrix metalloproteinase (MMP) expression. The present study was designed to investigate the effects of 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (PLAG) on MMP expression in epidermal growth factor (EGF)-stimulated breast cancer cells in vitro. EGF stimulation induced internalization of its cognate receptor, EGFR, for stimulus-desensitization. These internalized receptors, complexed with the ubiquitin ligase c-Cbl and EGFR pathway substrate 15 (EPS15) (for degradation), were evaluated by confocal microscopy at 5–90 min time intervals. During intracellular trafficking of EGFRs, EGF-induced signaling cascades were analyzed by examining EGFR and SHC phosphorylation. Modulation of MMP expression was assessed by evaluating the activity of transcription factor AP-1 using a luciferase assay. PLAG accelerated the assembly of EGFRs with c-Cbl and EPS15 and promoted receptor degradation. This faster intracellular EGFR degradation reduced AP-1-mediated MMP expression. PLAG stimulation upregulated thioredoxin-interacting protein (TXNIP) expression, and this mediated the accelerated receptor internalization. This PLAG-induced increase in EGFR trafficking was blocked in TXNIP-silenced cells. By downregulating MMP expression, PLAG effectively attenuated EGF-induced mobility and invasiveness in these cancer cells. These data suggest that PLAG may be a potential therapeutic agent for blocking metastasis.
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Affiliation(s)
- Kwang Hoon Yang
- Cell Factory Research Center, Division of Systems Biology and Bioengineering, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Republic of Korea
| | - Guen Tae Kim
- Cell Factory Research Center, Division of Systems Biology and Bioengineering, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Republic of Korea
| | - Solji Choi
- Cell Factory Research Center, Division of Systems Biology and Bioengineering, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Republic of Korea
| | - Sun Young Yoon
- Division of Global New Drug Development, ENZYCHEM Lifesciences, Jecheon, Chungcheongbukdo 27159, Republic of Korea
| | - Jae Wha Kim
- Cell Factory Research Center, Division of Systems Biology and Bioengineering, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Republic of Korea
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Functional cycle of EEA1-positive early endosome: Direct evidence for pre-existing compartment of degradative pathway. PLoS One 2020; 15:e0232532. [PMID: 32357161 PMCID: PMC7194439 DOI: 10.1371/journal.pone.0232532] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 04/16/2020] [Indexed: 01/11/2023] Open
Abstract
Early endosomes, regarded as the main sorting station on endocytic pathway, are characterized by high frequency of homotypic fusions mediated by tethering protein EEA1. Despite intensive investigations, biogenesis of endosomes, boundaries between early and late endosomes, and process of cargo transition though them remain obscure. Here, using EGF/EGFR endocytosis as a model and confocal microscopy of fixed and live cells, we provide evidence favoring EEA1-vesicles being pre-existed vesicular compartment, that maintains its resident proteins’ level and is sensitive to biosynthetic, but not endocytic pathway disturbance. EEA1-vesicles directly fuse with incoming EGF/EGFR-vesicles into hybrid endosomes with separated EEA1- and EGFR-domains, thus providing a platform for rapid achievement of an excess of surface-derived membrane that is used to form intraluminal vesicles (ILVs). Thus, multivesicular structures colocalized with EEA1 are still early endosomes. “EEA1-cycle” ends by exclusion of EGFR-containing domains with ILVs inside that turns into MVE and restoration of initial EEA1-vesicles population.
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miR-27b promotes angiogenesis and skin repair in scalded rats through regulating VEGF-C expression. Lasers Med Sci 2020; 35:1577-1588. [PMID: 32170506 DOI: 10.1007/s10103-020-02991-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 02/26/2020] [Indexed: 12/17/2022]
Abstract
In this study, the effects of miR-27b on angiogenesis in skin repair procedure in rats with deep II degree scald were explored. The rat model of deep II scald was established. miR-27b mimics and inhibitor were injected daily at the wound site for 3 weeks. The healing of scald was observed at 0, 3, 7, 14, and 21 days after the model was established, and the pathological changes of skin were observed by HE and Masson's trichrome stains. Skin tissues were taken 14 days after the operation; CD31 and Ki-67 immunohistochemistry was exerted to evaluate neovascularization and proliferation. Human microvascular endothelial cells (HMEC-1) cells were cultured in vitro. miR-27b mimics or inhibitor was transfected to construct over-expression or inhibition cell lines. MTT assay, scratch test, and angiogenesis test were used to evaluate cell proliferation, migration, and vascular regeneration. Finally, RT-PCR and Western blot were exerted to determine the expression of vascular endothelial growth factor C (VEGF-C), epidermal growth factor (EGF) mRNAs, and protein, respectively. Control, inhibitor, mi-NC, VEGF-C, inhibitor + si-NC, and inhibitor + VEGF-C siRNA groups were used to further analyze the mechanism of miR-27b on VEGF-C; the above experiments were repeated. In contrast to model group, miR-27b inhibitor could significantly promote the healing of scalded skin, alleviate the pathological status of scalded, and promote the angiogenesis and proliferation (p < 0.05). In vitro, miR-27b inhibitor evidently promoted cell proliferation, migration, and angiogenesis and increased the expression of VEGF-C, EGF genes, and protein, while miR-27b mimics significantly reversed the above trends. Further studies shown that downregulation of miR-27b expression can promote the proliferation, migration, and angiogenesis of HMEC-1 cells by promoting the expression of VEGF-C. miR-27b promotes angiogenesis and skin repair in scalded rats through regulating VEGF-C expression.
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