RESUMO
The blood-retinal barrier (BRB) is strongly compromised in diabetic retinopathy (DR) due to the detachment of pericytes (PCs) from retinal microvessels, resulting in increased permeability and impairment of the BRB. Western blots, immunofluorescence and ELISA were performed on adipose mesenchymal stem cells (ASCs) and pericyte-like (P)-ASCs by co-cultured human retinal endothelial cells (HRECs) under hyperglycemic conditions (HG), as a model of DR. Our results demonstrated that: (a) platelet-derived growth factor receptor (PDGFR) and its activated form were more highly expressed in monocultured P-ASCs than in ASCs, and this expression increased when co-cultured with HRECs under high glucose conditions (HG); (b) the transcription factor Nrf2 was more expressed in the cytoplasmic fraction of ASCs and in the P-ASC nuclear fraction, under normal glucose and, even more, under HG conditions; (c) cytosolic phospholipase A2 activity and prostaglandin E2 release, stimulated by HG, were significantly reduced in P-ASCs co-cultured with HRECs; (d) HO-1 protein content was significantly higher in HG-P-ASCs/HRECs than P-ASCs/HRECs; and (e) VEGF-A levels in media from HG-co-cultures were reduced in P-ASCs/HRECs with respect to ASCs/HRECs. The data obtained highlighted the potential of autologous differentiated ASCs in future clinical applications based on cell therapy to counteract the damage induced by DR.
Assuntos
Diabetes Mellitus , Retinopatia Diabética , Células-Tronco Mesenquimais , Humanos , Retinopatia Diabética/terapia , Retinopatia Diabética/metabolismo , Pericitos/metabolismo , Células Endoteliais/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Retina/metabolismo , Células-Tronco Mesenquimais/metabolismo , Glucose/metabolismo , Células Cultivadas , Diabetes Mellitus/metabolismoRESUMO
Lignans, a class of secondary metabolites found in plants, along with their derivatives, exhibit diverse pharmacological activities, including antioxidant, antimicrobial, anti-inflammatory, and antiangiogenic ones. Angiogenesis, the formation of new blood vessels from pre-existing ones, is a crucial process for cancer growth and development. Several studies have elucidated the synergistic relationship between angiogenesis and inflammation in various inflammatory diseases, highlighting a correlation between inflammation and vascular endothelial growth factor (VEGF)-induced angiogenesis. Thus, the identification of novel molecules capable of modulating VEGF effects presents promising prospects for developing therapies aimed at stabilizing, reversing, or even arresting disease progression. Lignans often suffer from low aqueous solubility and, for their use, encapsulation in a delivery system is needed. In this research, a bioinspired benzoxantene has been encapsulated in solid lipid nanoparticles that have been characterized for their pharmacotechnical properties and their thermotropic behavior. The effects of these encapsulated nanoparticles on angiogenic parameters and inflammation in VEGF-induced angiogenesis were evaluated using human brain microvascular endothelial cells (HBMECs) as a human blood-brain barrier model.
Assuntos
Barreira Hematoencefálica , Inflamação , Nanopartículas , Fator A de Crescimento do Endotélio Vascular , Humanos , Nanopartículas/química , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/patologia , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/metabolismo , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Lipídeos/química , Neovascularização Fisiológica/efeitos dos fármacos , Angiogênese , LipossomosRESUMO
Diabetic retinopathy (DR) is characterized by morphologic and metabolic alterations in endothelial cells (ECs) and pericytes (PCs) of the blood-retinal barrier (BRB). The loss of interendothelial junctions, increased vascular permeability, microaneurysms, and finally, EC detachment are the main features of DR. In this scenario, a pivotal role is played by the extensive loss of PCs. Based on previous results, the aim of this study was to assess possible beneficial effects exerted by adipose mesenchymal stem cells (ASCs) and their pericyte-like differentiated phenotype (P-ASCs) on human retinal endothelial cells (HRECs) in high glucose conditions (25 mM glucose, HG). P-ASCs were more able to preserve BRB integrity than ASCs in terms of (a) increased transendothelial electrical resistance (TEER); (b) increased expression of adherens junction and tight junction proteins (VE-cadherin and ZO-1); (c) reduction in mRNA levels of inflammatory cytokines TNF-α, IL-1ß, and MMP-9; (d) reduction in the angiogenic factor VEGF and in fibrotic TGF-ß1. Moreover, P-ASCs counteracted the HG-induced activation of the pro-inflammatory phospho-ERK1/2/phospho-cPLA2/COX-2 pathway. Finally, crosstalk between HRECs and ASCs or P-ASCs based on the PDGF-B/PDGFR-ß axis at the mRNA level is described herein. Thus, P-ASCs might be considered valuable candidates for therapeutic approaches aimed at countering BRB disruption in DR.
Assuntos
Diabetes Mellitus , Retinopatia Diabética , Células-Tronco Mesenquimais , Humanos , Retinopatia Diabética/metabolismo , Pericitos/metabolismo , Células Endoteliais/metabolismo , Retina/metabolismo , Células-Tronco Mesenquimais/metabolismo , Barreira Hematorretiniana/metabolismo , Glucose/metabolismo , RNA Mensageiro/metabolismo , Diabetes Mellitus/metabolismoRESUMO
There is substantial experimental and clinical interest in providing effective ways to both prevent and slow the onset of hearing loss. Auditory hair cells, which occur along the basilar membrane of the cochlea, often lose functionality due to age-related biological alterations, as well as from exposure to high decibel sounds affecting a diminished/damaged auditory sensitivity. Hearing loss is also seen to take place due to neuronal degeneration before or following hair cell destruction/loss. A strategy is necessary to protect hair cells and XIII cranial/auditory nerve cells prior to injury and throughout aging. Within this context, it was proposed that cochlea neural stem cells may be protected from such aging and environmental/noise insults via the ingestion of protective dietary supplements. Of particular importance is that these studies typically display a hormetic-like biphasic dose-response pattern that prevents the occurrence of auditory cell damage induced by various model chemical toxins, such as cisplatin. Likewise, the hormetic dose-response also enhances the occurrence of cochlear neural cell viability, proliferation, and differentiation. These findings are particularly important since they confirmed a strong dose dependency of the significant beneficial effects (which is biphasic), whilst having a low-dose beneficial response, whereas extensive exposures may become ineffective and/or potentially harmful. According to hormesis, phytochemicals including polyphenols exhibit biphasic dose-response effects activating low-dose antioxidant signaling pathways, resulting in the upregulation of vitagenes, a group of genes involved in preserving cellular homeostasis during stressful conditions. Modulation of the vitagene network through polyphenols increases cellular resilience mechanisms, thus impacting neurological disorder pathophysiology. Here, we aimed to explore polyphenols targeting the NF-E2-related factor 2 (Nrf2) pathway to neuroprotective and therapeutic strategies that can potentially reduce oxidative stress and inflammation, thus preventing auditory hair cell and XIII cranial/auditory nerve cell degeneration. Furthermore, we explored techniques to enhance their bioavailability and efficacy.
Assuntos
Surdez , Neurobiologia , Humanos , Polifenóis/farmacologia , Polifenóis/uso terapêutico , Cóclea , Envelhecimento/fisiologiaRESUMO
The stria vascularis (SV) contributes to cochlear homeostasis and consists of three layers, one of which contains the blood-labyrinthic barrier (BLB), with a large number of bovine cochlear pericytes (BCPs). Cisplatin is a chemotherapeutic drug that can damage the SV and cause hearing loss. In this study, cell viability, proliferation rate, cytotoxicity and reactive oxygen species production were evaluated. The protein content of phospho-extracellular signal-regulated kinases (ERK) 1/2, total ERK 1/2, phospho-cytosolic phospholipase A2 (cPLA2), total cPLA2 and cyclooxygenase 2 (COX-2) and the release of prostaglandin E2 (PGE2) and vascular endothelial growth factor (VEGF) from BCPs were analyzed. Finally, the protective effect of platelet-derived growth factor (PDGF-BB) on BCPs treated with cisplatin was investigated. Cisplatin reduced viability and proliferation, activated ERK 1/2, cPLA2 and COX-2 expression and increased PGE2 and VEGF release; these effects were reversed by Dexamethasone. The presence of PDGF-BB during the treatment with cisplatin significantly increased the proliferation rate. No studies on cell regeneration in ear tissue evaluated the effect of the PDGF/Dex combination. The aim of this study was to investigate the effects of cisplatin on cochlear pericytes and propose new otoprotective agents aimed at preventing the reduction of their vitality and thus maintaining the BLB structure.
Assuntos
Pericitos , Estria Vascular , Animais , Bovinos , Estria Vascular/metabolismo , Cisplatino/toxicidade , Cisplatino/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Becaplermina/metabolismo , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/metabolismo , Fator de Crescimento Derivado de Plaquetas/metabolismoRESUMO
SIGNIFICANCE: Contact lens (CL) wearing may cause discomfort and eye dryness. We describe here the efficacy of a synthetic polymer in protecting both the corneal epithelial cells and the CL from desiccation damage. Artificial tears containing this polymer might be helpful to treat or prevent ocular surface damage in CL wearers. PURPOSE: We aimed to investigate the protective effects of the synthetic polymer 2-methacryloyloxyethyl phosphorylcholine (poly-MPC) on corneal epithelial cells and CLs subjected to desiccation damage. METHODS: The interaction of poly-MPC with the cell membrane was evaluated on human primary corneal epithelial cells (HCE-F) by the sodium dodecyl sulfate damage protection assay or the displacement of the cell-binding lectin concanavalin A (ConA). Survival in vitro of HCE-F cells and ex vivo of porcine corneas exposed to desiccating conditions after pre-treatment with poly-MPC or hyaluronic acid (HA), hypromellose (HPMC), and trehalose was evaluated by a colorimetric assay. Soft CLs were soaked overnight in a solution of poly-MPC/HPMC and then let dry in ambient air. Contact lens weight, morphology, and transparency were periodically registered until complete dryness. RESULTS: Polymer 2-methacryloyloxyethyl phosphorylcholine and HPMC were retained on the HCE-F cell membrane more than trehalose or HA. Polymer 2-methacryloyloxyethyl phosphorylcholine, HA, and HPMC either alone or in association protected corneal cells from desiccation significantly better than did trehalose alone or in association with HA. Contact lens permeation by poly-MPC/HPMC preserved better their shape and transparency than did saline. CONCLUSIONS: Polymer 2-methacryloyloxyethyl phosphorylcholine coats and protects corneal epithelial cells and CLs from desiccation damage more efficiently compared with trehalose and as good as other reference compounds.
Assuntos
Lentes de Contato Hidrofílicas , Dessecação , Epitélio Corneano/efeitos dos fármacos , Fosforilcolina/análogos & derivados , Ácidos Polimetacrílicos/farmacologia , Falha de Prótese/efeitos dos fármacos , Animais , Células Cultivadas , Síndromes do Olho Seco/tratamento farmacológico , Humanos , Ácido Hialurônico/farmacologia , Derivados da Hipromelose/farmacologia , Fosforilcolina/farmacologia , Dodecilsulfato de Sódio/toxicidade , Suínos , Trealose/farmacologiaRESUMO
A pericyte-like differentiation of human adipose-derived mesenchymal stem cells (ASCs) was tested in in vitro experiments for possible therapeutic applications in cases of diabetic retinopathy (DR) to replace irreversibly lost pericytes. For this purpose, pericyte-like ASCs were obtained after their growth in a specific pericyte medium. They were then cultured in high glucose conditions to mimic the altered microenvironment of a diabetic eye. Several parameters were monitored, especially those particularly affected by disease progression: cell proliferation, viability and migration ability; reactive oxygen species (ROS) production; inflammation-related cytokines and angiogenic factors. Overall, encouraging results were obtained. In fact, even after glucose addition, ASCs pre-cultured in the pericyte medium (pmASCs) showed high proliferation rate, viability and migration ability. A considerable increase in mRNA expression levels of the anti-inflammatory cytokines transforming growth factor-ß1 (TGF-ß1) and interleukin-10 (IL-10) was observed, associated with reduction in ROS production, and mRNA expression of pro-inflammatory cytokines interleukin-1ß (IL-1ß) and tumor necrosis factor-α (TNF-α), and angiogenic factors. Finally, a pmASC-induced better organization of tube-like formation by retinal endothelial cells was observed in three-dimensional co-culture. The pericyte-like ASCs obtained in these experiments represent a valuable tool for the treatment of retinal damages occurring in diabetic patients.
Assuntos
Glucose/metabolismo , Células-Tronco Mesenquimais/efeitos dos fármacos , Pericitos/metabolismo , Tecido Adiposo/metabolismo , Adulto , Técnicas de Cultura de Células/métodos , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Meios de Cultivo Condicionados/farmacologia , Citocinas/metabolismo , Retinopatia Diabética/metabolismo , Feminino , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Itália , Células-Tronco Mesenquimais/metabolismo , Retina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator de Crescimento Transformador beta1/metabolismoRESUMO
Circular RNAs (circRNAs) are a large class of RNAs with regulatory functions within cells. We recently showed that circSMARCA5 is a tumor suppressor in glioblastoma multiforme (GBM) and acts as a decoy for Serine and Arginine Rich Splicing Factor 1 (SRSF1) through six predicted binding sites (BSs). Here we characterized RNA motifs functionally involved in the interaction between circSMARCA5 and SRSF1. Three different circSMARCA5 molecules (Mut1, Mut2, Mut3), each mutated in two predicted SRSF1 BSs at once, were obtained through PCR-based replacement of wild-type (WT) BS sequences and cloned in three independent pcDNA3 vectors. Mut1 significantly decreased its capability to interact with SRSF1 as compared to WT, based on the RNA immunoprecipitation assay. In silico analysis through the "Find Individual Motif Occurrences" (FIMO) algorithm showed GAUGAA as an experimentally validated SRSF1 binding motif significantly overrepresented within both predicted SRSF1 BSs mutated in Mut1 (q-value = 0.0011). U87MG and CAS-1, transfected with Mut1, significantly increased their migration with respect to controls transfected with WT, as revealed by the cell exclusion zone assay. Immortalized human brain microvascular endothelial cells (IM-HBMEC) exposed to conditioned medium (CM) harvested from U87MG and CAS-1 transfected with Mut1 significantly sprouted more than those treated with CM harvested from U87MG and CAS-1 transfected with WT, as shown by the tube formation assay. qRT-PCR showed that the intracellular pro- to anti-angiogenic Vascular Endothelial Growth Factor A (VEGFA) mRNA isoform ratio and the amount of total VEGFA mRNA secreted in CM significantly increased in Mut1-transfected CAS-1 as compared to controls transfected with WT. Our data suggest that GAUGAA is the RNA motif responsible for the interaction between circSMARCA5 and SRSF1 as well as for the circSMARCA5-mediated control of GBM cell migration and angiogenic potential.
Assuntos
Adenosina Trifosfatases/genética , Movimento Celular , Proteínas Cromossômicas não Histona/genética , Glioblastoma/irrigação sanguínea , Glioblastoma/patologia , Neovascularização Patológica/patologia , RNA Circular/metabolismo , Fatores de Processamento de Serina-Arginina/metabolismo , Apoptose , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Proliferação de Células , Células Endoteliais/patologia , Regulação Neoplásica da Expressão Gênica , Glioblastoma/genética , Glioblastoma/metabolismo , Humanos , Motivos de Nucleotídeos , Prognóstico , RNA Circular/genética , Fatores de Processamento de Serina-Arginina/genética , Células Tumorais CultivadasRESUMO
Graphene oxide (GO) is a bidimensional novel material that exhibits high biocompatibility and angiogenic properties, mostly related to the intracellular formation of reactive oxygen species (ROS). In this work, we set up an experimental methodology for the fabrication of GO@peptide hybrids by the immobilization, via irreversible physical adsorption, of the Ac-(GHHPH)4-NH2 peptide sequence, known to mimic the anti-angiogenic domain of the histidine-proline-rich glycoprotein (HPRG). The anti-proliferative capability of the graphene-peptide hybrids were tested in vitro by viability assays on prostate cancer cells (PC-3 line), human neuroblastoma (SH-SY5Y), and human retinal endothelial cells (primary HREC). The anti-angiogenic response of the two cellular models of angiogenesis, namely endothelial and prostate cancer cells, was scrutinized by prostaglandin E2 (PGE2) release and wound scratch assays, to correlate the activation of inflammatory response upon the cell treatments with the GO@peptide nanocomposites to the cell migration processes. Results showed that the GO@peptide nanoassemblies not only effectively induced toxicity in the prostate cancer cells, but also strongly blocked the cell migration and inhibited the prostaglandin-mediated inflammatory process both in PC-3 and in HRECs. Moreover, the cytotoxic mechanism and the internalization efficiency of the theranostic nanoplatforms, investigated by mitochondrial ROS production analyses and confocal microscopy imaging, unraveled a dose-dependent manifold mechanism of action performed by the hybrid nanoassemblies against the PC-3 cells, with the detection of the GO-characteristic cell wrapping and mitochondrial perturbation. The obtained results pointed out to the very promising potential of the synthetized graphene-based hybrids for cancer therapy.
Assuntos
Grafite/farmacologia , Nanocompostos/química , Neoplasias/terapia , Neovascularização Patológica/terapia , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Terapia Baseada em Transplante de Células e Tecidos/tendências , Células Endoteliais/efeitos dos fármacos , Grafite/química , Humanos , Masculino , Neoplasias/patologia , Neovascularização Patológica/patologia , Neuroblastoma/terapia , Estresse Oxidativo/efeitos dos fármacos , Neoplasias da Próstata/terapia , Espécies Reativas de Oxigênio/metabolismoRESUMO
Vascular pericytes are an important cellular component in the tumor microenvironment, however, their role in supporting cancer invasion is poorly understood. We hypothesized that PDGF-BB could be involved in the transition of human retinal pericytes (HRPC) in cancer-activated fibroblasts (CAF), induced by the 92.1 uveal melanoma (UM) cell line. In our model system, HRPC were conditioned by co-culturing with 92.1UM for 6 days (cHRPC), in the presence or absence of imatinib, to block PDGF receptor-ß (PDGFRß). The effects of the treatments were tested by wound healing assay, proliferation assay, RT-PCR, high-content screening, Western blot analysis, and invasion assay. Results showed profound changes in cHRPC shape, with increased proliferation and motility, reduction of NG2 and increase of TGF-ß1, α-SMA, vimentin, and FSP-1 protein levels, modulation of PDGF isoform mRNA levels, phospho-PDGFRß, and PDGFRß, as well as phospho-STAT3 increases. A reduction of IL-1ß and IFNγ and an increase in TNFα, IL10, and TGF-ß1, CXCL11, CCL18, and VEGF mRNA in cHRPC were found. Imatinib was effective in preventing all the 92.1UM-induced changes. Moreover, cHRPC elicited a significant increase of 92.1UM cell invasion and active MMP9 protein levels. Our data suggest that retinal microvascular pericytes could promote 92.1UM growth through the acquisition of the CAF phenotype.
Assuntos
Becaplermina/genética , Melanoma/metabolismo , Pericitos/metabolismo , Receptor beta de Fator de Crescimento Derivado de Plaquetas/genética , Neoplasias Uveais/metabolismo , Fibroblastos Associados a Câncer/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Técnicas de Cocultura , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Mesilato de Imatinib/farmacologia , Metaloproteinase 9 da Matriz/genética , Melanoma/tratamento farmacológico , Melanoma/genética , Melanoma/patologia , Proteínas de Neoplasias/genética , Pericitos/efeitos dos fármacos , Pericitos/patologia , Retina/metabolismo , Retina/patologia , Fator de Crescimento Transformador beta1/genética , Microambiente Tumoral/efeitos dos fármacos , Neoplasias Uveais/tratamento farmacológico , Neoplasias Uveais/genética , Neoplasias Uveais/patologia , CicatrizaçãoRESUMO
Early blood retinal barrier (BRB) dysfunction induced by hyperglycemia was related to increased pro-inflammatory activity of phospholipase A2 (PLA2) and the upregulation of vascular endothelial growth factor A (VEGF-A). Here, we tested the role of VEGF-A in high glucose (HG)-induced damage of human retinal endothelial cells (HRECs) mediated by Ca++-dependent (cPLA2) and Ca++-independent (iPLA2) PLA2s. HRECs were treated with normal glucose (5 mM, NG) or high glucose (25 mM, HG) for 48 h with or without the VEGF-trap Aflibercept (Afl, 40 µg/mL), the cPLA2 inhibitor arachidonoyl trifluoromethyl ketone (AACOCF3; 15 µM), the iPLA2 inhibitor bromoenol lactone (BEL; 5 µM), or VEGF-A (80 ng/mL). Both Afl and AACOCF3 prevented HG-induced damage (MTT and LDH release), impairment of angiogenic potential (tube-formation), and expression of VEGF-A mRNA. Furthermore, Afl counteracted HG-induced increase of phospho-ERK and phospho-cPLA2 (immunoblot). VEGF-A in HG-medium increased glucose toxicity, through upregulation of phospho-ERK, phospho-cPLA2, and iPLA2 (about 55%, 45%, and 50%, respectively); immunocytochemistry confirmed the activation of these proteins. cPLA2 knockdown by siRNA entirely prevented cell damage induced by HG or by HG plus VEGF-A, while iPLA2 knockdown produced a milder protective effect. These data indicate that VEGF-A mediates the early glucose-induced damage in retinal endothelium through the involvement of ERK1/2/PLA2 axis activation.
Assuntos
Retinopatia Diabética/metabolismo , Células Endoteliais/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Fosfolipases A2/metabolismo , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular/metabolismo , Inibidores da Angiogênese/farmacologia , Ácidos Araquidônicos/farmacologia , Células Cultivadas , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/patologia , Endotélio Vascular/citologia , Glucose/toxicidade , Humanos , Inibidores de Fosfolipase A2/farmacologia , Receptores de Fatores de Crescimento do Endotélio Vascular , Proteínas Recombinantes de Fusão/farmacologiaRESUMO
Angiogenesis is involved in many pathological states such as progression of tumours, retinopathy of prematurity and diabetic retinopathy. The latter is a more complex diabetic complication in which neurodegeneration plays a significant role and a leading cause of blindness. The vascular endothelial growth factor (VEGF) is a powerful pro-angiogenic factor that acts through three tyrosine kinase receptors (VEGFR-1, VEGFR-2 and VEGFR-3). In this work we studied the anti-angiogenic effect of quercetin (Q) and some of its derivates in human microvascular endothelial cells, as a blood retinal barrier model, after stimulation with VEGF-A. We found that a permethylated form of Q, namely 8MQPM, more than the simple Q, is a potent inhibitor of angiogenesis both in vitro and ex vivo. Our results showed that these compounds inhibited cell viability and migration and disrupted the formation of microvessels in rabbit aortic ring. The addition of Q and more significantly 8MQPM caused recoveries or completely re-establish the transendothelial electrical resistance (TEER) to the control values and suppressed the activation of VEGFR2 downstream signalling molecules such as AKT, extracellular signal-regulated kinase, and c-Jun N-terminal kinase. Taken together, these data suggest that 8MQPM might have an important role in the contrast of angiogenesis-related diseases.
Assuntos
Inibidores da Angiogênese/farmacologia , Barreira Hematorretiniana/efeitos dos fármacos , Endotélio Vascular/metabolismo , Éteres Metílicos/farmacologia , Neovascularização Patológica/tratamento farmacológico , Quercetina/farmacologia , Fator A de Crescimento do Endotélio Vascular/farmacologia , Animais , Barreira Hematorretiniana/patologia , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Endoteliais/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Masculino , Éteres Metílicos/química , Neovascularização Patológica/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-jun/metabolismo , Quercetina/análogos & derivados , Quercetina/química , Coelhos , Retina/citologia , Transdução de Sinais/efeitos dos fármacos , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Receptor 3 de Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
Pericytes are branched cells located in the wall of capillary blood vessels that are found throughout the body, embedded within the microvascular basement membrane and wrapping endothelial cells, with which they establish a strong physical contact. Pericytes regulate angiogenesis, vessel stabilization, and contribute to the formation of both the blood-brain and blood-retina barriers by Angiopoietin-1/Tie-2, platelet derived growth factor (PDGF) and transforming growth factor (TGF) signaling pathways, regulating pericyte-endothelial cell communication. Human pericytes that have been cultured for a long period give rise to multilineage progenitor cells and exhibit mesenchymal stem cell (MSC) features. We focused our attention on the roles of pericytes in brain and ocular diseases. In particular, pericyte involvement in brain ischemia, brain tumors, diabetic retinopathy, and uveal melanoma is described. Several molecules, such as adenosine and nitric oxide, are responsible for pericyte shrinkage during ischemia-reperfusion. Anti-inflammatory molecules, such as IL-10, TGFß, and MHC-II, which are increased in glioblastoma-activated pericytes, are responsible for tumor growth. As regards the eye, pericytes play a role not only in ocular vessel stabilization, but also as a stem cell niche that contributes to regenerative processes in diabetic retinopathy. Moreover, pericytes participate in melanoma cell extravasation and the genetic ablation of the PDGF receptor reduces the number of pericytes and aberrant tumor microvessel formation with important implications for therapy efficacy. Thanks to their MSC features, pericytes could be considered excellent candidates to promote nervous tissue repair and for regenerative medicine.
Assuntos
Encéfalo/fisiologia , Microvasos/fisiologia , Pericitos/fisiologia , Regeneração/fisiologia , Retina/fisiologia , Vasos Retinianos/fisiologia , Animais , Barreira Hematoencefálica/fisiologia , Barreira Hematorretiniana/fisiologia , Encéfalo/irrigação sanguínea , Humanos , Microvasos/citologia , Pericitos/citologiaRESUMO
The aim of the present study was to investigate, in the Statens Seruminstitut Rabbit Cornea (SIRC) cell line, the presence of epithelial and fibroblastic markers, comparing their levels with those of the human Retinal Pigmented Epithelial (ARPE-19) cell line, and the Human Keratocyte (HK) cell line, respectively. SIRC cells, often described as of epithelial origin, are used as a corneal epithelial barrier model to study the permeability of ophthalmic drugs. However, they show a morphology that is more consistent with a fibroblastic cell phenotype, similar to corneal keratocytes. Our comparative analyses of cell type specific markers demonstrated that SIRC do not express cytokeratins 19 and 16 (typical of ARPE-19) and cytokeratin 9 (typical of HK); they do express cytokeratins 3 and 18 common to all three cell lines, and cytokeratin 12 typical of ARPE-19. Tight junction proteins were absent in HK, and lower in SIRC than in ARPE-19. All cell lines expressed the markers lumican and vimentin, with SIRC expressing intermediate levels between HK and ARPE-19; alpha-SMA was highly expressed in all lines. These markers, considered typical of fibroblasts, can be, however, expressed by epithelial cells during wound healing. These results might suggest that long-term in vitro cultivation of cell lines leads to a derangement of their specific phenotype, most likely due to genetic and epigenetic factors. This could be the reason why SIRC cells came to exhibit a hybrid nature between epithelial and fibroblastic cells.
Assuntos
Biomarcadores/metabolismo , Ceratócitos da Córnea/citologia , Epitélio Corneano/citologia , Animais , Linhagem Celular , Ceratócitos da Córnea/metabolismo , Epitélio Corneano/metabolismo , Fenótipo , Coelhos , Epitélio Pigmentado da Retina/citologia , Epitélio Pigmentado da Retina/metabolismoRESUMO
Dry eye is the most prominent pathology among those involving the ocular surface: a decrease of the aqueous (less frequent) or the lipid (more frequent) component of the tear film is the cause of the diminished stability of tears that is observed in this pathology. Dry eye shows a clear distribution linked to both sex (being more frequent among women) and age (increasing with aging). Therefore, specific treatments taking into account the etiology of the disease would be desired. The role of lactoferrin and its functional mimetic lactobionic acid are reported here as a possible remedy for age-related dry eye.
Assuntos
Dissacarídeos/fisiologia , Síndromes do Olho Seco/metabolismo , Lactoferrina/fisiologia , Lágrimas/metabolismo , HumanosRESUMO
PURPOSE: Preservatives are used in multi-dose ophthalmic topical medications in order to prevent contamination by bacteria and fungi. However, prolonged use of preserved eye drops, as it may happen in dry eye or glaucoma, may damage cells of the ocular surface. Therefore, an important goal is to find preservatives with low toxicity which are mild to host cells, still able to prevent drug contamination so to maintain their sterility and efficacy. Hence, aim of this study has been to compare the relative toxicity on a rabbit corneal cell line of a new preservative, made by the association of N-hydroxy-methyl-glycinate (NIG) with disodium-ethylene diamine tetra-acetate (EDTA), with other known and widely used eye-drops preservatives. MATERIALS AND METHODS: Rabbit corneal cells (SIRC) were tested either in 96-well plates or in suspension culture. Treatments with preservatives (used at known bacteriostatic concentrations) included: benzalkonium chloride (BAK), polyquaternium-1 (PQ-1), sodium perborate (SP: NaBO3 * H2O), and NIG ± EDTA at different concentrations (0.001% and 0.002%), and different treatment times (from 30 minutes to 120 hours). At the end of treatment, cell survival was evaluated by a specific spectrophotometric method through the metabolic conversion of MTT [3-(4,5-dimethylthiazol-2-yl) 2, 5-diphenyltetrazolium bromide] into formazan crystals. RESULTS: Almost no cell toxicity was evident for NIG and SP at either concentration (0.001% or 0.002%), while a low toxicity was observed for PQ-1 (62% at the highest dose at 120 hours). BAK, as expected, showed the highest toxicity (60-80% at 30 minutes, and over 90% from eight hours onward). EDTA 0.1% alone or in combination with NIG 0.002%, showed no toxicity at 24 hours, and even resulted in cell growth promotion (46% and 38%, respectively), after 48 hours of treatment. CONCLUSIONS: These data show that the new preservative NIG/EDTA, at doses known to have effective antimicrobial properties, has a very low toxicity on corneal cells, and so it can be safely used in multi-dose eye drops.
Assuntos
Córnea/citologia , Ácido Edético/toxicidade , Conservantes Farmacêuticos/toxicidade , Sarcosina/análogos & derivados , Animais , Compostos de Benzalcônio/toxicidade , Boratos/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Soluções Oftálmicas , Polímeros/toxicidade , Coelhos , Sarcosina/toxicidadeRESUMO
BACKGROUND: The molecular nature of lipoic acid (LA) clarifies its capability of taking part to a variety of biochemical reactions where redox state is meaningful. The pivotal action of LA is the antioxidant activity due to its ability to scavenge and inactivate free radicals. Furthermore, LA has been shown to chelate toxic metals both directly and indirectly by its capability to enhance intracellular glutathione (GSH) levels. This last property is due to its ability to interact with GSH and recycle endogenous GSH. LA exhibits significant antioxidant activity protecting against oxidative damage in several diseases, including neurodegenerative disorders. Interestingly, LA is unique among natural antioxidants for its capability to satisfy a lot of requirements, making it a potentially highly effective therapeutic agent for many conditions related with oxidative damage. In particular, there are evidences showing that LA has therapeutic activity in lowering glucose levels in diabetic conditions. Similarly, LA supplementation has multiple beneficial effects on the regression of the mitochondrial function and on oxidative stress associated with several diseases and aging. AIM: The aim of the present review is to describe the molecular mechanisms underlying the beneficial effects of LA under various experimental conditions and disease and how to exploit such effect for clinical purposes. CONCLUSION: LA has pleiotropic effects in different pathways related with several diseases, its use as a potential therapeutic agent is very promising.
Assuntos
Anti-Inflamatórios , Antioxidantes , Ácido Tióctico , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Humanos , Transdução de Sinais , Ácido Tióctico/farmacologia , Ácido Tióctico/uso terapêuticoRESUMO
The key aspect of neonatal meningitis is related to the ability of pathogens to invade the blood-brain barrier (BBB) and to penetrate the central nervous system. In the present study we show that, in an in vitro model of BBB, on the basis of co-culturing primary bovine brain endothelial cells (BBEC) and primary bovine retinal pericytes (BRPC), Escherichia coli infection determines changes of transendothelial electrical resistance (TEER) and permeability (Pe) to sodium fluorescein. In the co-culture model, within BBEC, bacteria are able to stimulate cytosolic and Ca(2+)-independent phospholipase A2 (cPLA2 and iPLA2 ) enzyme activities. In supernatants of E. coli-stimulated co-cultures, an increase in prostaglandins (PGE2) and VEGF production in comparison with untreated co-cultures were found. Incubation with E. coli in presence of AACOCF3 or BEL caused a decrease of PGE2 and VEGF release. SEM and TEM images of BBEC and BRPC showed E. coli adhesion to BBEC and BRPC but only in BBEC the invasion occurs. VEGFR-1 but not VEGFR-2 blockade by the specific antibody reduced E. coli invasion in BBEC. In our model of BBB infection, a significant loss of BRPC was observed. Following VEGFR-1, but not VEGFR-2 blockade, or in presence of AACOCF3 or BEL, elevated TEER values, reduced permeability and BRPC loss were found. These data suggest that VEGFR-1 negatively regulates BRPC survival and its blockade protects the barrier integrity. PGs and VEGF could exert a biological effect on BBB, probably by BRPC coverage ablation, thus increasing BBB permeability. Our results show the role played by the BBEC as well as BRPC during a bacterial attack on BBB. A better understanding of the mechanisms by which E. coli enter the nervous system and how bacteria alter the communication between endothelial cells and pericytes may provide exciting new insight for clinical intervention.
Assuntos
Barreira Hematoencefálica/microbiologia , Barreira Hematoencefálica/fisiopatologia , Endotélio Vascular/patologia , Infecções por Escherichia coli/fisiopatologia , Escherichia coli/patogenicidade , Pericitos/patologia , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/fisiologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Aderência Bacteriana/fisiologia , Barreira Hematoencefálica/patologia , Bovinos , Permeabilidade da Membrana Celular/fisiologia , Sobrevivência Celular/fisiologia , Células Cultivadas , Técnicas de Cocultura , Dinoprostona/metabolismo , Modelos Animais de Doenças , Impedância Elétrica , Endotélio Vascular/microbiologia , Escherichia coli/fisiologia , Infecções por Escherichia coli/metabolismo , Infecções por Escherichia coli/patologia , Fluoresceína , Corantes Fluorescentes , Pericitos/microbiologia , Fosfolipases A2/metabolismo , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/efeitos dos fármacos , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/imunologiaRESUMO
Significance: The stria vascularis, located in the inner ear, consists of three layers, one of which is the blood-labyrinth barrier (BLB). It is formed by endothelial cells, sealed together to prevent the passage of toxic substances from the blood to the inner ear, by pericytes and perivascular-resident macrophage-like melanocyte. Recent Advances: There are various causes that lead to hearing loss, and among these are noise-induced and autoimmune hearing loss, ear disorders related to ototoxic medication, Ménière's disease, and age-related hearing loss. For all of these, major therapeutic interventions include drug-loaded nanoparticles, via intratympanic or intracochlear delivery. Critical Issues: Since many pathologies associated with hearing loss are characterized by a weakening of the BLB, in this review, the molecular mechanisms underlying the response to damage of BLB cellular components have been discussed. In addition, insight into the role of hormetic nutrients against hearing loss pathology is proposed. Future Directions: BLB cellular components of neurovascular cochlear unit play important physiological roles, owing to their impermeable function against all ototoxic substances that can induce damage. Studies are needed to investigate the cross talk occurring between these cellular components to exploit their possible role as novel targets for therapeutic interventions that may unravel future path based on the use of hormetic nutrients. Antioxid. Redox Signal. 40, 542-563.
Assuntos
Orelha Interna , Perda Auditiva , Humanos , Células Endoteliais , Cóclea , PericitosRESUMO
Following the publication of the above article, an interested reader drew to the authors' attention that, in Fig. 7 on p. 1282, a pair of the western blotting bands in the Akt blot positioned adjacent to each other looked strikingly similar. Although the authors considered that the data were correct as shown (and the Editorial Office were in agreement that it was not certain that the bands were identical), to avoid any possible confusion or suspicion, the authors requested that the figure be reprinted showing the Akt data obtained from one of the repeated experiments. The revised version of Fig. 7, containing the replacement data for the Akt western blotting data, is shown opposite. All the authors agree with the publication of this corrigendum, and are grateful to the Editor of International Journal of Molecular Medicine for allowing them the opportunity to publish this for the purposes of clarifying the presented data. [International Journal of Molecular Medicine 40: 12771284, 2017; DOI: 10.3892/ijmm.2017.3104].