| 1. |
- Borbely, Gabor, 1981-, et al.
(author)
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The role of neurokinin A in corneal wound repair
- 2015
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In: Investigative Ophthalmology and Visual Science. - Rockville, MD, USA : Assoc Research Vision Ophthalmology Inc. - 0146-0404 .- 1552-5783. ; 56:7
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Journal article (other academic/artistic)
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| 2. |
- El-Habta, Roine, et al.
(author)
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The adipose tissue stromal vascular fraction secretome enhances the proliferation but inhibits the differentiation of myoblasts
- 2018
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In: Stem Cell Research & Therapy. - : BioMed Central. - 1757-6512. ; 9
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Journal article (peer-reviewed)abstract
- Background: Adipose tissue is an excellent source for isolation of stem cells for treating various clinical conditions including injuries to the neuromuscular system. Many previous studies have focused on differentiating these adipose stem cells (ASCs) towards a Schwann cell-like phenotype (dASCs), which can enhance axon regeneration and reduce muscle atrophy. However, the stromal vascular fraction (SVF), from which the ASCs are derived, also exerts broad regenerative potential and might provide a faster route to clinical translation of the cell therapies for treatment of neuromuscular disorders.Methods: The aim of this study was to establish the effects of SVF cells on the proliferation and differentiation of myoblasts using indirect co-culture experiments. A Growth Factor PCR Array was used to compare the secretomes of SVF and dASCs, and the downstream signaling pathways were investigated.Results: SVF cells, unlike culture-expanded dASCs, expressed and secreted hepatocyte growth factor (HGF) at concentrations sufficient to enhance the proliferation of myoblasts. Pharmacological inhibitor studies revealed that the signal is mediated via ERK1/2 phosphorylation and that the effect is significantly reduced by the addition of 100 pM Norleual, a specific HGF inhibitor. When myoblasts were differentiated into multinucleated myotubes, the SVF cells reduced the expression levels of fast-type myosin heavy chain (MyHC2) suggesting an inhibition of the differentiation process.Conclusions: In summary, this study shows the importance of HGF as a mediator of the SVF effects on myoblasts and provides further evidence for the importance of the secretome in cell therapy and regenerative medicine applications.
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| 3. |
- Erttmann, Saskia F., et al.
(author)
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Loss of the DNA Damage Repair Kinase ATM Impairs Inflammasome-Dependent Anti-Bacterial Innate Immunity
- 2016
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In: Immunity. - : Elsevier BV. - 1074-7613 .- 1097-4180. ; 45:1, s. 106-118
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Journal article (peer-reviewed)abstract
- The ATM kinase is a central component of the DNA damage repair machinery and redox balance. ATM dysfunction results in the multisystem disease ataxia-telangiectasia (AT). A major cause of mortality in AT is respiratory bacterial infections. Whether ATM deficiency causes innate immune defects that might contribute to bacterial infections is not known. Here we have shown that loss of ATM impairs inflammasome- dependent anti-bacterial innate immunity. Cells from AT patients or Atm(-/-) mice exhibited diminished interleukin-1 beta (IL-1 beta) production in response to bacteria. In vivo, Atm(-/-) mice were more susceptible to pulmonary S. pneumoniae infection in a manner consistent with inflammasome defects. Our data indicate that such defects were due to oxidative inhibition of inflammasome complex assembly. This study reveals an unanticipated function of reactive oxygen species (ROS) in negative regulation of inflammasomes and proposes a theory for the notable susceptibility of AT patients to pulmonary bacterial infection.
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| 4. |
- Roux, Sandrine Le, et al.
(author)
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Transforming Growth Factor Beta 1 Modulates the Functional Expression of the Neurokinin-1 Receptor in Human Keratocytes
- 2016
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In: Current Eye Research. - : Informa UK Limited. - 0271-3683 .- 1460-2202. ; 41:8, s. 1035-1043
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Journal article (peer-reviewed)abstract
- PURPOSE: Transforming growth factor beta 1 (TGF-β1) is a cytokine involved in a variety of processes, such as differentiation of fibroblasts into myofibroblasts. TGF-β1 has also been shown to delay the internalization of the neurokinin-1 receptor (NK-1 R) after its activation by its ligand, the neuropeptide substance P (SP). NK-1 R comprises two naturally occurring variants, a full-length and a truncated form, triggering different cellular responses. SP has been shown to affect important events in the cornea - such as stimulating epithelial cell proliferation - processes that are involved in corneal wound healing and thus in maintaining the transparency of the corneal stroma. An impaired signaling through NK-1 R could thus impact the visual quality. We hypothesize that TGF-β1 modulates the expression pattern of NK-1 R in human corneal stroma cells, keratocytes. The purpose of this study was to test that hypothesis.METHODS: Cultures of primary keratocytes were set up with cells derived from healthy human corneas, obtained from donated transplantation graft leftovers, and characterized by immunocytochemistry and Western blot. Immunocytochemistry for TGF-β receptors and NK-1 R was performed. Gene expression was assessed with real-time polymerase chain reaction (qPCR).RESULTS: Expression of TGF-β receptors was confirmed in keratocytes in vitro. Treating the cells with TGF-β1 significantly reduced the gene expression of NK-1 R. Furthermore, immunocytochemistry for NK-1 R demonstrated that it is specifically the expression of the full-length isotype of the receptor that is reduced after treatment with TGF-β1, which was also confirmed with qPCR using a specific probe for the full-length receptor.CONCLUSIONS: TGF-β1 down-regulates the gene expression of the full-length variant of NK-1 R in human keratocytes, which might impact its signaling pathway and thus explain the known delay in internalization after activation by SP seen with TGF-β1 treatment.
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| 5. |
- Sloniecka, Marta, et al.
(author)
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Acetylcholine decreases formation of myofibroblasts and excessive extracellular matrix components production in an in vitro human corneal fibrosis model
- 2018
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In: Investigative Ophthalmology and Visual Science. - : The Association for Research in Vision and Ophthalmology, Inc.. - 0146-0404 .- 1552-5783. ; 59:9
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Journal article (other academic/artistic)abstract
- Purpose : Acetylcholine (ACh) is a neurotransmitter present in corneal stroma and produced by keratocytes. It has been shown to play a role in processes important for wound healing. Based on literature and our previous studies, we hypothesize that ACh regulates expression of extracellular matrix (ECM) components that are overexpressed during fibrosis, such as collagens, proteoglycans, fibronectin and metalloproteinases, in a protective manner during corneal fibrosis, i.e. decreasing their expression.Methods : Primary keratocytes were isolated from healthy human corneas obtained from the local cornea bank and grown in presence of 10% fetal bovine serum in order to obtain corneal fibroblasts. A corneal fibrosis in vitro model, in which fibroblasts are stimulated with transforming growth factor beta 1 (TGF-β1) and stable vitamin C, was used throughout this study. Contractile ability of myofibroblasts was tested using a cell contraction assay. Gene expression of ECM components (collagen I, collagen III, collagen V and lumican), markers of fibrosis (α-smooth muscle actin [α-SMA] and fibronectin), and metalloproteinases (MMP2, MMP9 and MMP12) were assessed by qRT-PCR. Intracellular production and secretion of pro-collagen I and lumican was determined by ELISA. α-SMA protein expression was assessed by western blot.Results : ACh decreased the contractile ability of the newly formed myofibroblasts. ACh significantly decreased gene expression of collagen I, collagen III and collagen V in myofibroblasts. Moreover, ACh treated cells produced and secreted less pro-collagen I. Gene expression of lumican was unaffected by ACh treatment up to day 2 but significantly decreased by day 4. However, no differences in lumican protein level, both intracellular and secreted, were found. ACh downregulated expression of both α-SMA and fibronectin genes. Additionally, α-SMA protein expression was also diminished in ACh treated cells. Furthermore, ACh treatment resulted in downregulation of MMP2, MMP9 and MMP12 genes.Conclusions : Our results are consistent with our hypothesis that ACh regulates expression of various collagens, lumican, fibronectin and metalloproteinases during corneal fibrosis in vitro, in a way that it diminishes their expression, both on RNA and protein levels. In conclusion, ACh seems to provide protection against formation of fibrosis in human cornea.
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| 6. |
- Sloniecka, Marta, et al.
(author)
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Acetylcholine decreases formation of myofibroblasts and excessive extracellular matrix production in an in vitro human corneal fibrosis model
- 2020
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In: Journal of Cellular and Molecular Medicine (Print). - : John Wiley & Sons. - 1582-1838 .- 1582-4934. ; 24:8, s. 4850-4862
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Journal article (peer-reviewed)abstract
- Acetylcholine (ACh) has been reported to play various physiological roles, including wound healing in the cornea. Here, we study the role of ACh in the transition of corneal fibroblasts into myofibroblasts, and in consequence its role in the onset of fibrosis, in an in vitro human corneal fibrosis model. Primary human keratocytes were obtained from healthy corneas. Vitamin C (VitC) and transforming growth factor-β1 (TGF-β1) were used to induce fibrosis in corneal fibroblasts. qRT-PCR and ELISA analyses showed that gene expression and production of collagen I, collagen III, collagen V, lumican, fibronectin (FN) and alpha-smooth muscle actin (α-SMA) were reduced by ACh in quiescent keratocytes. ACh treatment furthermore decreased gene expression and production of collagen I, collagen III, collagen V, lumican, FN and α-SMA during the transition of corneal fibroblasts into myofibroblasts, after induction of fibrotic process. ACh inhibited corneal fibroblasts from developing contractile activity during the process of fibrosis, as assessed with collagen gel contraction assay. Moreover, the effect of ACh was dependent on activation of muscarinic ACh receptors. These results show that ACh has an anti-fibrotic effect in an in vitro human corneal fibrosis model, as it negatively affects the transition of corneal fibroblasts into myofibroblasts. Therefore, ACh might play a role in the onset of fibrosis in the corneal stroma.
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| 7. |
- Słoniecka, Marta, et al.
(author)
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Acetylcholine enhances keratocyte proliferation through muscarinic receptor activation.
- 2015
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In: International Immunopharmacology. - : Elsevier BV. - 1567-5769 .- 1878-1705. ; 29:1, s. 57-62
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Journal article (peer-reviewed)abstract
- Acetylcholine (ACh), a classical neurotransmitter, has been shown to be present in various non-neuronal cells, including cells of the eye, such as corneal epithelium and endothelium, and to have widespread physiological effects such as cytoskeleton reorganization, cellular proliferation, differentiation, and apoptosis. The aim of this study was to investigate the effect of ACh on corneal keratocyte proliferation, and the underlying mechanisms, in order to explore its possible effect in corneal wound healing. Primary culture of human keratocytes was established from donated corneas. Cell viability and fraction of proliferating cells were detected by MTS assay and BrdU incorporation ELISA, respectively. Expression of proliferative markers, PCNA and Ki-67, was detected by western blot and immunocytochemistry. Activation of the MAPK/Erk signaling pathway and its involvement in ACh-enhanced proliferation was determined by western blot analysis, MTS, and BrdU ELISA. We found that ACh enhanced keratocyte proliferation even at low concentrations. Stimulation of proliferation was mediated through activation of muscarinic ACh receptors (mAChRs). Western blot analysis revealed that ACh stimulation of keratocytes upregulated the expression of PCNA and Ki-67, and Ki-67 immunocytochemistry showed that ACh-treated cells were in an active phase of the cell cycle. ACh activated MAPK signaling, and this step was crucial for the ACh-enhanced proliferation, as inhibition of the MAPK pathway resulted in ACh having no proliferative effect. In conclusion, ACh enhances keratocyte proliferation and might thus play a role in proper corneal wound healing.
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| 8. |
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| 9. |
- Sloniecka, Marta, 1983-, et al.
(author)
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Acetylcholine induces proliferation of keratocytes through activation of muscarinic receptors
- 2015
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In: Investigative Ophthalmology and Visual Science. - : Association for Research in Vision and Ophthalmology. - 0146-0404 .- 1552-5783. ; 56:7
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Journal article (other academic/artistic)abstract
- Purpose: The corneal wound healing response is a complex process involving cytokine-mediated interactions between epithelial cells, keratocytes of the stroma, corneal nerves, tear film, and cells of the immune system. The outcome of the response plays a critical role in the preservation of corneal transparency after injury. The wound healing cascade includes epithelial surface closure, keratocyte apoptosis, proliferation and migration, formation of myofibroblasts, and stromal remodeling. Acetylcholine (ACh) is regarded as a classical neurotransmitter. However, cells outside of the nervous system have been shown to contain and release ACh. It has been reported that ACh stimulates fibroblast and epithelial cells to proliferate, has an anti-inflammatory effect in macrophages, and upregulates collagen gene expression in fibroblasts. ACh, its muscarinic receptors (mAChRs) and choline acetyltransferase (ChAT; the enzyme responsible for synthesizing ACh) have been shown to be present in corneal epithelium. However, their role in the corneal stroma and corneal injury has not been extensively studied. We hypothesize that ACh, upon injury, induces corneal stroma cell proliferation, thus promoting the process of wound healing.Methods: Primary human corneal stroma cells were derived from healthy corneas obtained from the local cornea bank. Immunocytochemistry was performed to delineate intracellular presence of ChAT and to characterize mAChRs. Crystal violet and MTS assay were used to asses ACh induced cell proliferation. Expression of the proliferation markers PCNA and Ki67 was analyzed by western blot. To determine what type of ACh receptors are involved in ACh induced proliferation, atropine and mecamylamine were used to block muscarininc or nicotinic ACh receptors, respectively.Results: Stromal cells expressed ChAT as well as mAChRs of subtypes M1, M3, M4, and M5. Stimulation of stromal cells with ACh led to increased cell viability and metabolic activity. Expression of PCNA and Ki67 was upregulated in ACh treated cells. Furthermore, mAChRs were the receptor group primarily involved in ACh induced proliferation.Conclusions: Corneal stroma cells express ChAT and mAChRs. ACh induces stroma cell proliferation through mainly mAChRs, which suggest that ACh may play an important role in corneal wound healing i.e. wound closure and generation on myofibroblasts.
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| 10. |
- Sloniecka, Marta, et al.
(author)
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Antiapoptotic Effect of Acetylcholine in Fas-Induced Apoptosis in Human Keratocytes
- 2016
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In: Investigative Ophthalmology and Visual Science. - : Association for Research in Vision and Ophthalmology (ARVO). - 0146-0404 .- 1552-5783. ; 57:14, s. 5892-5902
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Journal article (peer-reviewed)abstract
- PURPOSE. To investigate the possible antiapoptotic effect of acetylcholine (ACh) in Fas-mediated apoptosis of primary human keratocytes in vitro, and to explore the underlying mechanism. METHODS. Primary human keratocytes were isolated from healthy corneas. Fas ligand (FasL) was used to induce apoptosis in keratocytes. Cell death was assessed by ELISA. Activity of caspase-3, -7, -8, and -9 was measured with luminescent caspase activity assays. Expression of nuclear factor-kappa B (NF-kappa B) gene was assessed with RT-quantitative (q)PCR. Cytochrome c release apoptosis assay kit was used to extract mitochondria and cytosol. Cytochrome c release, cleavage of Bid, and expression of B-cell lymphoma 2 (Bcl-2) were determined by Western blot. RESULTS. Cell death ELISA revealed that ACh is able to reduce Fas-induced apoptosis in keratocytes. Analysis of the activity of effector caspases-3 and -7 showed that ACh, when added to Fas-treated cells, decreases the activation of both these enzymes. The activity of initiator caspases -8 and -9 also decreased when ACh was added to Fas-treated cells. This antiapoptotic effect of ACh was dependent on ACh concentration and activation of muscarinic ACh receptors. Analysis of the antiapoptotic mechanisms triggered by ACh showed that ACh downregulates expression of FasL-induced NF-kappa B RNA expression, upregulates expression of antiapoptotic protein Bcl-2, downregulates expression of proapoptotic protein Bad, reduces cytochrome c release, and prevents proapoptotic Bid protein cleavage. CONCLUSIONS. Acetylcholine has an antiapoptotic effect in a Fas-apoptosis model of human primary keratocytes in vitro. It is therefore possible that ACh may play a role in corneal wound healing, by modulating its initiation phase.
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