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1.
Biomater Adv ; 161: 213894, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38796956

RESUMO

Engineering of scaffolds for bone regeneration is often inspired by the native extracellular matrix mimicking its composite fibrous structure. In the present study, we used low loadings of diatomite earth (DE) biosilica to improve the bone regeneration potential of gelatin electrospun fibrillar microenvironments. We explored the effect of increasing the DE content from 1 % to 3 % and 5 %, respectively, on the physico-chemical properties of the fibrous scaffolds denoted FG_DE1, FG_DE3, FG_DE5, regarding the aqueous media affinity, stability under simulated physiological conditions, morphology characteristics, and local mechanical properties at the surface. The presence of biosilica generated composite structures with lower swelling degrees and higher stiffness when compared to gelatin fibers. Increasing DE content led to higher Young modulus, while the stability of the protein matrix in PBS, at 37 °C, over 21 was significantly decreased by the presence of diatomite loadings. The best preosteoblast response was obtained for FG_DE3, with enhanced mineralization during the osteogenic differentiation when compared to the control sample without diatomite. 5 % DE in FG_DE5 proved to negatively influence cells' metabolic activity and morphology. Hence, the obtained composite microfibrillar scaffolds might find application as osteoblast-responsive materials for bone tissue engineering.


Assuntos
Gelatina , Osteoblastos , Engenharia Tecidual , Alicerces Teciduais , Gelatina/química , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Alicerces Teciduais/química , Engenharia Tecidual/métodos , Animais , Terra de Diatomáceas/química , Osteogênese/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Camundongos , Regeneração Óssea/efeitos dos fármacos , Linhagem Celular , Microambiente Celular/efeitos dos fármacos , Microfibrilas/química , Microfibrilas/metabolismo , Matriz Extracelular/metabolismo , Matriz Extracelular/química , Matriz Extracelular/efeitos dos fármacos
2.
J Funct Biomater ; 14(12)2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-38132814

RESUMO

The current study reports the use of silver (Ag) and samarium (Sm) as dopants to improve the properties of standard bioglass in terms of biological performance. This experiment considers thin films of doped bioglass obtained by pulsed laser deposition (PLD) and spin coating (SC). For both methods, some parameters were gradually varied, as the main objective was to produce a bioglass that could be used in biomedical fields. In order to study the morphology, the phase composition and other properties, the samples obtained were subjected to multiple analyses, such as thermal analysis, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared (FT-IR), Raman spectroscopy, and x-ray diffraction (XRD). Furthermore, the in vitro bioactivity of the samples, as assessed through simulated body fluid (SBF) immersion, as well as immunocytochemistry and evaluation of actin filaments, assessed through fluorescence microscopy, are reported. The results confirmed the formation of the designed vitreous target employed as the source of material in the PLD experiments only at sintering temperatures below 800 °C; this vitreous nature was preserved in the grown film as well. The presence of Ag and Ce dopants in the parent glassy matrix was validated for all stages, from powder, to target, to PLD/SC-derived coatings. Additionally, it was demonstrated that the surface topography of the layers can be adjusted by using substrates with different roughness or by modulating the processing parameters, such as substrate temperature and working pressure in PLD, rotation speed, and number of layers in SC. The developed material was found to be highly bioactive after 28 days of immersion in SBF, but it was also found to be a potential candidate for inhibiting the growth of Gram-negative bacteria and a suitable support for cell growth and proliferation.

3.
Int J Mol Sci ; 24(19)2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37834167

RESUMO

Cellular asymmetry is an important element of efficiency in the compartmentalization of intracellular chemical reactions that ensure efficient tissue function. Improving the current 3D printing methods by using cellular asymmetry is essential in producing complex tissues and organs such as the liver. The use of cell spots containing at least two cells and basement membrane-like bio support materials allows cells to be tethered at two points on the basement membrane and with another cell in order to maintain cell asymmetry. Our model is a new type of 3D bioprinter that uses oriented multicellular complexes with cellular asymmetry. This novel approach is necessary to replace the sequential and slow processes of organogenesis with rapid methods of growth and 3D organ printing. The use of the extracellular matrix in the process of bioprinting with cells allows one to preserve the cellular asymmetry in the 3D printing process and thus preserve the compartmentalization of biological processes and metabolic efficiency.


Assuntos
Bioimpressão , Alicerces Teciduais , Alicerces Teciduais/química , Engenharia Tecidual , Impressão Tridimensional , Hepatócitos , Fígado
4.
Pharmaceutics ; 15(5)2023 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-37242662

RESUMO

The skin is a complex and selective system from the perspective of permeability to substances from the external environment. Microemulsion systems have demonstrated a high performance in encapsulating, protecting and transporting active substances through the skin. Due to the low viscosity of microemulsion systems and the importance of a texture that is easy to apply in the cosmetic and pharmaceutical fields, gel microemulsions are increasingly gaining more interest. The aim of this study was to develop new microemulsion systems for topical use; to identify a suitable water-soluble polymer in order to obtain gel microemulsions; and to study the efficacy of the developed microemulsion and gel microemulsion systems in the delivery of a model active ingredient, namely curcumin, into the skin. A pseudo-ternary phase diagram was developed using AKYPO® SOFT 100 BVC, PLANTACARE® 2000 UP Solution and ethanol as a surfactant mix; caprylic/capric triglycerides, obtained from coconut oil, as the oily phase; and distilled water. To obtain gel microemulsions, sodium hyaluronate salt was used. All these ingredients are safe for the skin and are biodegradable. The selected microemulsions and gel microemulsions were physicochemically characterized by means of dynamic light scattering, electrical conductivity, polarized microscopy and rheometric measurements. To evaluate the efficiency of the selected microemulsion and gel microemulsion to deliver the encapsulated curcumin, an in vitro permeation study was performed.

5.
Int J Mol Sci ; 23(24)2022 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-36555821

RESUMO

Bacterial cellulose (BC) is a unique microbial biopolymer with a huge number of significant applications in the biomedical field, including bone tissue engineering. The present study proposes to obtain and characterize BC hybrid composites with calcium phosphate as biocompatible and bioactive membranes for bone tissue engineering. BC precursor membranes were obtained in static culture fermentation, and after purification, were oxidized to obtain 2,3-dialdehyde bacterial cellulose (DABC). Calcium phosphate-BC oxidized membranes were produced by successive immersion in precursor solutions under ultrasonic irradiation. The samples were characterized for their physicochemical properties using scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy, attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy grazing incidence X-ray diffraction (GI-XRD), solid-state 13C nuclear magnetic resonance (CP/MAS 13C NMR), and complex thermal analysis. In vitro cell studies were also performed to evaluate the influence of modified morphological characteristics on cell adhesion and proliferation. The results showed an increase in porosity and biodegradability for DABC hybrid composites compared with BC. In vitro cell studies have revealed that both hybrid composites favor cell adhesion to the surface. The new BC and DABC hybrid composites with calcium phosphate could be considered promising materials for bone tissue regeneration.


Assuntos
Materiais Biocompatíveis , Celulose , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/química , Celulose/química , Engenharia Tecidual , Materiais Dentários , Bactérias/metabolismo , Microscopia Eletrônica de Varredura , Difração de Raios X , Regeneração Óssea , Fosfatos de Cálcio/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier
6.
Int J Mol Sci ; 23(13)2022 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-35806023

RESUMO

This review article explores the telocytes' roles in inflammatory bowel diseases (IBD), presenting the mechanisms and hypotheses related to epithelial regeneration, progressive fibrosis, and dysmotility as a consequence of TCs' reduced or absent number. Based on the presented mechanisms and hypotheses, we aim to provide a functional model to illustrate TCs' possible roles in the normal and pathological functioning of the digestive tract. TCs are influenced by the compression of nearby blood vessels and the degree of fibrosis of the surrounding tissues and mediate these processes in response. The changes in intestinal tube vascularization induced by the movement of the food bowl, and the consequent pH changes that show an anisotropy in the thickness of the intestinal tube wall, have led to the identification of a pattern of intestinal tube development based on telocytes' ability to communicate and modulate surrounding cell functions. In the construction of the theoretical model, given the predictable occurrence of colic in the infant, the two-layer arrangement of the nerve plexuses associated with the intestinal tube was considered to be incompletely adapted to the motility required with a diversified diet. There is resulting evidence of possible therapeutic targets for diseases associated with changes in local nerve tissue development.


Assuntos
Doenças Inflamatórias Intestinais , Telócitos , Fibrose , Humanos , Doenças Inflamatórias Intestinais/patologia , Telócitos/patologia
7.
J Clin Med ; 10(24)2021 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-34945118

RESUMO

BACKGROUND: Faecal microbiota transplant (FMT) is a highly effective therapy for recurrent Clostridioides difficile infection (rCDI) with cure rates ranging between 85 and 92%. The FMT role for primary Clostridioides difficile infection (CDI) has yet to be settled because of limited data and small-sample studies presented in the current literature. Our study goals were to report the risk factors and the risk of recurrence after FMT for each CDI episode (first, second, and third) and to explore if there is a role of FMT in primary severe CDI. METHODS: We conducted a retrospective study to analyze the clinical characteristics and the outcomes of 96 FMT patients with a prior 10 day course of antibiotic treatment in the medical records, of which 71 patients with recurrent CDI and 25 patients with a primary CDI. RESULTS: The overall primary cure rate in our study was 88.5% and the primary cure rate for the severe forms was 85.7%. The data analysis revealed 5.25%, 15.15%, and 27.3% FMT recurrence rates for primary, secondary, and tertiary severe CDI. The risk of recurrence was significantly associated with FMT after the second and the third CDI severe episodes (p < 0.05), but not with FMT after the first severe CDI episode. CONCLUSIONS: This study brings new data in supporting the FMT role in CDI treatment, including the primary severe CDI, however, further prospective and controlled studies on larger cohorts should be performed in this respect.

8.
Brain Sci ; 11(9)2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34573189

RESUMO

BACKGROUND: Urinary tract infections (UTIs) are considered common facilitating factors, along with other infections, in triggering febrile seizures (FS). The main purpose of our study was to identify specific inflammatory patterns of UTI cases from other infections in a specific cluster, using a combination of inflammatory biomarkers to differentiate UTIs from other bacterial diseases triggering FS. METHOD: This prospective study included a number of 136 patients with 197 distinct FS events, from patients hospitalized in the Pediatric Clinical Hospital Sibiu, among which 10.2% were diagnosed with UTIs. RESULTS: In one-third of the patients with UTIs (20 cases), the symptoms were limited to fever and FS. Using two-step cluster analysis, a distinct UTI inflammatory pattern has emerged: highest platelet values (PLT), median value 331 × 103/mm3 and intermediate C-reactive protein (CRP), median value 15 mg/dL, platelet distribution width (PDW), median value 9.65%, platelet-large cell ratio (P-LCR), median value 14.45%, mean platelet volume (MPV), median value 8.60 fL and neutrophil-to-lymphocyte values (NLR), median value 3.64. Furthermore, higher PDW (median value 12.25%), P-LCR (median value 28.55%), MPV (median value 10.40 fL), CRP (median value 74.00 mg/dL) and NLR values (median value 4.11) were associated mainly (85.7%) with bacterial lower respiratory infections. UTIs were highly unlikely in these patients with significantly increased CRP values and normal values of platelet indices. CONCLUSIONS: Considering the nonspecific clinical picture of UTIs at an early age, to optimize the management of FS, a fast diagnosis of UTI is mandatory. The analysis of the inflammatory biomarker clusters (rather than individual parameters) correlated with urine leukocyte and nitrite stick evaluation for specific age groups could help in identifying even oligosymptomatic UTIs patients. The study limitation (20 UTI cases) recommends future multicentric trials on larger datasets to validate the model.

9.
Polymers (Basel) ; 12(8)2020 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-32806530

RESUMO

In this work, composite fibers connected in three-dimensional porous scaffolds were fabricated by electrospinning, starting from polycaprolactone and inorganic powders synthesized by the sol-gel method. The aim was to obtain materials dedicated to the field of bone regeneration, with controllable properties of bioresorbability and bioactivity. The employed powders were nanometric and of a glass-ceramic type, a fact that constitutes the premise of a potential attachment to living tissue in the physiological environment. The morphological characterization performed on the composite materials validated both the fibrous character and oxide powder distribution within the polymer matrix. Regarding the biological evaluation, the period of immersion in simulated body fluid led to the initiation of polymer degradation and a slight mineralization of the embedded particles, while the osteoblast cells cultured in the presence of these scaffolds revealed a spatial distribution at different depths and a primary networking tendency, based on the composites' geometrical and dimensional features.

10.
Int J Mol Sci ; 20(8)2019 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-31013625

RESUMO

The neuron-specific Elav-like Hu RNA-binding proteins were described to play an important role in neuronal differentiation and plasticity by ensuring the post-transcriptional control of RNAs encoding for various proteins. Although Elav-like Hu proteins alterations were reported in diabetes or neuropathy, little is known about the regulation of neuron-specific Elav-like Hu RNA-binding proteins in sensory neurons of dorsal root ganglia (DRG) due to the diabetic condition. The goal of our study was to analyze the gene and protein expression of HuB, HuC, and HuD in DRG sensory neurons in diabetes. The diabetic condition was induced in CD-1 adult male mice with single-intraperitoneal injection of streptozotocin (STZ, 150 mg/kg), and 8-weeks (advanced diabetes) after induction was quantified the Elav-like proteins expression. Based on the glycemia values, we identified two types of responses to STZ, and mice were classified in STZ-resistant (diabetic resistant, glycemia < 260 mg/dL) and STZ-sensitive (diabetic, glycemia > 260 mg/dL). Body weight measurements indicated that 8-weeks after STZ-induction of diabetes, control mice have a higher increase in body weight compared to the diabetic and diabetic resistant mice. Moreover, after 8-weeks, diabetic mice (19.52 ± 3.52 s) have longer paw withdrawal latencies in the hot-plate test than diabetic resistant (11.36 ± 1.92 s) and control (11.03 ± 1.97 s) mice, that correlates with the installation of warm hypoalgesia due to the diabetic condition. Further on, we evidenced the decrease of Elav-like gene expression in DRG neurons of diabetic mice (Elavl2, 0.68 ± 0.05 fold; Elavl3, 0.65 ± 0.01 fold; Elavl4, 0.53 ± 0.07 fold) and diabetic resistant mice (Ealvl2, 0.56 ± 0.07 fold; Elavl3, 0.32 ± 0.09 fold) compared to control mice. Interestingly, Elav-like genes have a more accentuated downregulation in diabetic resistant than in diabetic mice, although hypoalgesia was evidenced only in diabetic mice. The Elav-like gene expression changes do not always correlate with the Hu protein expression changes. To detail, HuB is upregulated and HuD is downregulated in diabetic mice, while HuB, HuC, and HuD are downregulated in diabetic resistant mice compared to control mice. To resume, we demonstrated HuD downregulation and HuB upregulation in DRG sensory neurons induced by diabetes, which might be correlated with altered post-transcriptional control of RNAs involved in the regulation of thermal hypoalgesia condition caused by the advanced diabetic neuropathy.


Assuntos
Proteína Semelhante a ELAV 2/genética , Proteína Semelhante a ELAV 3/genética , Proteína Semelhante a ELAV 4/genética , Gânglios Espinais/citologia , Gânglios Espinais/metabolismo , Regulação da Expressão Gênica , Células Receptoras Sensoriais/metabolismo , Animais , Biomarcadores , Glicemia , Peso Corporal , Diabetes Mellitus Experimental , Proteína Semelhante a ELAV 2/metabolismo , Proteína Semelhante a ELAV 3/metabolismo , Proteína Semelhante a ELAV 4/metabolismo , Gânglios Espinais/fisiopatologia , Imuno-Histoquímica , Camundongos , Proteínas de Ligação a RNA
11.
Int J Mol Sci ; 19(5)2018 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-29747396

RESUMO

Voltage-gated calcium channels and estrogen receptors are essential players in uterine physiology, and their association with different calcium signaling pathways contributes to healthy and pathological conditions of the uterine myometrium. Among the properties of the various cell subtypes present in human uterine myometrium, there is increasing evidence that calcium oscillations in telocytes (TCs) contribute to contractile activity and pregnancy. Our study aimed to evaluate the effects of beta-estradiol on voltage-gated calcium channels and estrogen receptors in TCs from human uterine myometrium and to understand their role in pregnancy. For this purpose, we employed patch-clamp recordings, ratiometric Fura-2-based calcium imaging analysis, and qRT-PCR techniques for the analysis of cultured human myometrial TCs derived from pregnant and non-pregnant uterine samples. In human myometrial TCs from both non-pregnant and pregnant uterus, we evidenced by qRT-PCR the presence of genes encoding for voltage-gated calcium channels (Cav3.1, Ca3.2, Cav3.3, Cav2.1), estrogen receptors (ESR1, ESR2, GPR30), and nuclear receptor coactivator 3 (NCOA3). Pregnancy significantly upregulated Cav3.1 and downregulated Cav3.2, Cav3.3, ESR1, ESR2, and NCOA3, compared to the non-pregnant condition. Beta-estradiol treatment (24 h, 10, 100, 1000 nM) downregulated Cav3.2, Cav3.3, Cav1.2, ESR1, ESR2, GRP30, and NCOA3 in TCs from human pregnant uterine myometrium. We also confirmed the functional expression of voltage-gated calcium channels by patch-clamp recordings and calcium imaging analysis of TCs from pregnant human myometrium by perfusing with BAY K8644, which induced calcium influx through these channels. Additionally, we demonstrated that beta-estradiol (1000 nM) antagonized the effect of BAY K8644 (2.5 or 5 µM) in the same preparations. In conclusion, we evidenced the presence of voltage-gated calcium channels and estrogen receptors in TCs from non-pregnant and pregnant human uterine myometrium and their gene expression regulation by beta-estradiol in pregnant conditions. Further exploration of the calcium signaling in TCs and its modulation by estrogen hormones will contribute to the understanding of labor and pregnancy mechanisms and to the development of effective strategies to reduce the risk of premature birth.


Assuntos
Canais de Cálcio/metabolismo , Estradiol/farmacologia , Miométrio/citologia , Receptores de Estrogênio/metabolismo , Telócitos/metabolismo , Éster Metílico do Ácido 3-Piridinacarboxílico, 1,4-Di-Hidro-2,6-Dimetil-5-Nitro-4-(2-(Trifluormetil)fenil)/farmacologia , Adulto , Canais de Cálcio/genética , Sinalização do Cálcio/efeitos dos fármacos , Células Cultivadas , Regulação para Baixo/efeitos dos fármacos , Feminino , Humanos , Pessoa de Meia-Idade , Gravidez , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Telócitos/efeitos dos fármacos
12.
Adv Exp Med Biol ; 998: 255-269, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28936745

RESUMO

Circulating exosomes could arrive in distant tissues via blood circulation, thus directly communicating with target cells and rapidly regulating intracellular signalings. Circulating exosomes and exosomal cargos are critically involved in cardiovascular pathophysiology, such as cardiomyocyte hypertrophy, apoptosis, and angiogenesis. Circulating exosomes enriched with various types of biological molecules can be changed not only in the number but also in the composite cargos upon cardiac injury, such as myocardial infarction, myocardial ischemia reperfusion injury, atherosclerosis, hypertension, and sepsis cardiomyopathy, which may further influence cardiomyocyte function and contribute to the pathogenesis of cardiovascular diseases. Thus, exosome-based therapeutic strategy may be used to attenuate myocardial injury and promote cardiac regeneration and repair. Also, more preclinical and clinical studies would be needed to investigate the potential of circulating exosomes as biomarkers for the diagnosis, risk stratification, and prognosis of cardiovascular diseases.


Assuntos
Doenças Cardiovasculares/sangue , Exossomos/metabolismo , Animais , Biomarcadores/sangue , Doenças Cardiovasculares/diagnóstico , Exossomos/patologia , Humanos , Valor Preditivo dos Testes , Prognóstico
13.
Sci Rep ; 7(1): 5083, 2017 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-28698560

RESUMO

Clinical and experimental studies indicate that muscarinic acetylcholine receptors are potential pharmacological targets for the treatment of neurological diseases. Although these receptors have been described in human, bovine and rat cerebral microvascular tissue, a subtype functional characterization in mouse brain endothelium is lacking. Here, we show that all muscarinic acetylcholine receptors (M1-M5) are expressed in mouse brain microvascular endothelial cells. The mRNA expression of M2, M3, and M5 correlates with their respective protein abundance, but a mismatch exists for M1 and M4 mRNA versus protein levels. Acetylcholine activates calcium transients in brain endothelium via muscarinic, but not nicotinic, receptors. Moreover, although M1 and M3 are the most abundant receptors, only a small fraction of M1 is present in the plasma membrane and functions in ACh-induced Ca2+ signaling. Bioinformatic analyses performed on eukaryotic muscarinic receptors demonstrate a high degree of conservation of the orthosteric binding site and a great variability of the allosteric site. In line with previous studies, this result indicates muscarinic acetylcholine receptors as potential pharmacological targets in future translational studies. We argue that research on drug development should especially focus on the allosteric binding sites of the M1 and M3 receptors.


Assuntos
Encéfalo/irrigação sanguínea , Endotélio Vascular/metabolismo , Microvasos/metabolismo , Receptores Muscarínicos/metabolismo , Acetilcolina/farmacologia , Sítio Alostérico , Animais , Sítios de Ligação , Sinalização do Cálcio/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Endotélio Vascular/citologia , Camundongos Endogâmicos BALB C , Receptores Muscarínicos/química , Receptores Nicotínicos/metabolismo
14.
Int J Mol Sci ; 18(2)2017 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-28208829

RESUMO

In this review, we describe the current knowledge on calcium signaling pathways in interstitial cells with a special focus on interstitial cells of Cajal (ICCs), interstitial Cajal-like cells (ICLCs), and telocytes. In detail, we present the generation of Ca2+ oscillations, the inositol triphosphate (IP3)/Ca2+ signaling pathway and modulation exerted by cytokines and vasoactive agents on calcium signaling in interstitial cells. We discuss the physiology and alterations of calcium signaling in interstitial cells, and in particular in telocytes. We describe the physiological contribution of calcium signaling in interstitial cells to the pacemaking activity (e.g., intestinal, urinary, uterine or vascular pacemaking activity) and to the reproductive function. We also present the pathological contribution of calcium signaling in interstitial cells to the aortic valve calcification or intestinal inflammation. Moreover, we summarize the current knowledge of the role played by calcium signaling in telocytes in the uterine, cardiac and urinary physiology, and also in various pathologies, including immune response, uterine and cardiac pathologies.


Assuntos
Sinalização do Cálcio , Cálcio/metabolismo , Células do Tecido Conjuntivo/metabolismo , Telócitos/metabolismo , Animais , Sinalização do Cálcio/efeitos dos fármacos , Células do Tecido Conjuntivo/classificação , Células do Tecido Conjuntivo/ultraestrutura , Citocinas/metabolismo , Humanos , Imunofenotipagem , Inflamação/metabolismo , Inflamação/patologia , Células Intersticiais de Cajal/metabolismo , Células Intersticiais de Cajal/ultraestrutura , Fenótipo , Telócitos/ultraestrutura
15.
Semin Cell Dev Biol ; 64: 26-39, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27569187

RESUMO

Telocytes (TCs), located ubiquitously in the internal organs of vertebrates, are a heterogeneous, recently described, cell population of the stromal space. Characterized by lengthy cytoplasmic extensions that can reach tens of microns and are called telopodes (Tps), TCs are difficult to see using conventional microscopes. It was the electron microscopy which led to their first identification and Popescu's team the first responsible for the reconstructions indicating TCs 'organization' in a three-dimensional (3D) network that is believed to be accountable for the complex roles of TCs. Gradually, it became increasingly evident that TCs are difficult to characterize in terms of immunophenotype and that their phenotype is different depending on the location and needs of the tissue at one time. This review discusses the growing body of evidence accumulated since TCs were discovered and highlights how the complex interplay between TCs and stem cells might be of importance for tissue engineering and regenerative medicine.


Assuntos
Forma Celular , Telócitos/citologia , Animais , Fenômenos Eletrofisiológicos , Humanos , Imunofenotipagem , Modelos Biológicos , Proteômica , Telócitos/ultraestrutura
16.
Adv Exp Med Biol ; 913: 287-302, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27796895

RESUMO

Telocytes (TCs) are interstitial cells described in multiple structures, including the gastrointestinal tract, respiratory tract, urinary tract, uterus, and heart. Several studies have indicated the possibility that TCs are involved in the pacemaker potential in these organs. It is supposed that TCs are interacting with the neighboring muscular cells and their network contributes to the initiation and propagation of the electrical potentials. In order to understand the contribution of TCs to various excitability mechanisms, it is necessary to analyze the plasma membrane proteins (e.g., ion channels) functionally expressed in these cells. So far, potassium, calcium, and chloride currents, but not sodium currents, have been described in TCs in primary cell culture from different tissues. Moreover, TCs have been described as sensors for mechanical stimuli (e.g., contraction, extension, etc.). In conclusion, TCs might play an essential role in gastrointestinal peristalsis, in respiration, in pregnant uterus contraction, or in miction, but further highlighting studies are necessary to understand the molecular mechanisms and the cell-cell interactions by which TCs contribute to the tissue excitability and pacemaker potentials initiation/propagation.


Assuntos
Relógios Biológicos/fisiologia , Ativação do Canal Iônico/fisiologia , Potenciais da Membrana/fisiologia , Telócitos/fisiologia , Animais , Canais de Cálcio Tipo L/genética , Canais de Cálcio Tipo L/metabolismo , Canais de Cloreto/genética , Canais de Cloreto/metabolismo , Tecido Conjuntivo/fisiologia , Regulação da Expressão Gênica , Cobaias , Humanos , Canais de Potássio KCNQ/genética , Canais de Potássio KCNQ/metabolismo , Camundongos , Técnicas de Patch-Clamp , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Ratos , Telócitos/citologia , Canais de Sódio Disparados por Voltagem/genética , Canais de Sódio Disparados por Voltagem/metabolismo
17.
Adv Protein Chem Struct Biol ; 103: 137-67, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26920689

RESUMO

Acid-sensing ion channels (ASICs) are widely expressed in the body and represent good sensors for detecting protons. The pH drop in the nervous system is equivalent to ischemia and acidosis, and ASICs are very good detectors in discriminating slight changes in acidity. ASICs are important pharmacological targets being involved in a variety of pathophysiological processes affecting both the peripheral nervous system (e.g., peripheral pain, diabetic neuropathy) and the central nervous system (e.g., stroke, epilepsy, migraine, anxiety, fear, depression, neurodegenerative diseases, etc.). This review discusses the role played by ASICs in different pathologies and the pharmacological agents acting on ASICs that might represent promising drugs. As the majority of above-mentioned pathologies involve not only neuronal dysfunctions but also microvascular alterations, in the next future, ASICs may be also considered as potential pharmacological targets at the vasculature level. Perspectives and limitations in the use of ASICs antagonists and modulators as pharmaceutical agents are also discussed.


Assuntos
Canais Iônicos Sensíveis a Ácido/genética , Doenças do Sistema Nervoso Central/tratamento farmacológico , Neurônios/efeitos dos fármacos , Doenças do Sistema Nervoso Periférico/tratamento farmacológico , Bloqueadores do Canal Iônico Sensível a Ácido/uso terapêutico , Canais Iônicos Sensíveis a Ácido/efeitos dos fármacos , Doenças do Sistema Nervoso Central/classificação , Doenças do Sistema Nervoso Central/genética , Humanos , Terapia de Alvo Molecular , Neurônios/patologia , Doenças do Sistema Nervoso Periférico/classificação , Doenças do Sistema Nervoso Periférico/genética , Agonistas de Canais de Sódio/uso terapêutico
18.
Histochem Cell Biol ; 143(1): 83-94, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25212658

RESUMO

Recently, telocytes (TCs) were described as a new cell type in the interstitial space of many organs, including myometrium. TCs are cells with very long, distinctive extensions named telopodes (Tps). It is suggested that TCs play a major role in intercellular signaling, as well as in morphogenesis, especially in morphogenetic bioelectrical signaling. However, TC plasma membrane is yet unexplored regarding the presence and activity of ion channels and pumps. Here, we used a combination of in vitro immunofluorescence and patch-clamp technique to characterize T-type calcium channels in TCs. Myometrial TCs were identified in cell culture (non-pregnant and pregnant myometrium) as cells having very long Tps and which were positive for CD34 and platelet-derived growth factor receptor-α. Immunofluorescence analysis of the subfamily of T-type (transient) calcium channels CaV3.1 and CaV3.2 presence revealed the expression of these ion channels on the cell body and Tps of non-pregnant and pregnant myometrium TCs. The expression in TCs from the non-pregnant myometrium is less intense, being confined to the cell body for CaV3.2, while CaV3.1 was expressed both on the cell body and in Tps. Moreover, the presence of T-type calcium channels in TCs from non-pregnant myometrium is also confirmed by applying brief ramp depolarization protocols. In conclusion, our results show that T-type calcium channels are present in TCs from human myometrium and could participate in the generation of endogenous bioelectric signals responsible for the regulation of the surrounding cell behavior, during pregnancy and labor.


Assuntos
Canais de Cálcio Tipo T/metabolismo , Eletrofisiologia , Útero/citologia , Separação Celular , Feminino , Humanos , Imuno-Histoquímica , Células Estromais/citologia , Células Estromais/metabolismo , Útero/metabolismo
19.
Lasers Med Sci ; 29(6): 1867-74, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24870411

RESUMO

Telocytes (TCs) are a brand-new cell type frequently observed in the interstitial space of many organs (see www.telocytes.com ). TCs are defined by very long (tens of micrometers) and slender prolongations named telopodes. At their level, dilations-called podoms (~300 nm), alternate with podomers (80-100 nm). TCs were identified in a myometrial interstitial cell culture based on morphological criteria and by CD34 and PDGF receptor alpha (PDGFRα) immunopositivity. However, the mechanism(s) of telopodes formation and/or elongation and ramification is not known. We report here the low-level laser stimulation (LLLS) using a 1,064-nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser (with an output power of 60 mW) of the telopodal lateral extension (TLE) growth in cell culture. LLLS of TCs determines a higher growth rate of TLE in pregnant myometrium primary cultures (10.3 ± 1.0 µm/min) compared to nonpregnant ones (6.6 ± 0.9 µm/min). Acute exposure (30 min) of TCs from pregnant myometrium to 1 µM mibefradil, a selective inhibitor of T-type calcium channels, determines a significant reduction in the LLLS TLE growth rate (5.7 ± 0.8 µm/min) compared to LLLS per se in same type of samples. Meanwhile, chronic exposure (24 h) completely abolishes the LLLS TLE growth in both nonpregnant and pregnant myometria. The initial direction of TLE growth was modified by LLLS, the angle of deviation being more accentuated in TCs from human pregnant myometrium than in TCs from nonpregnant myometrium. In conclusion, TCs from pregnant myometrium are more susceptible of reacting to LLLS than those from nonpregnant myometrium. Therefore, some implications are emerging for low-level laser therapy (LLLT) in uterine regenerative medicine.


Assuntos
Terapia com Luz de Baixa Intensidade/métodos , Miométrio/patologia , Telócitos/patologia , Adulto , Antígenos CD34/metabolismo , Biópsia , Feminino , Humanos , Histerectomia , Lasers de Estado Sólido , Pessoa de Meia-Idade , Miométrio/efeitos da radiação , Neodímio/química , Gravidez , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Telócitos/efeitos da radiação , Útero/efeitos da radiação
20.
Cell Biochem Biophys ; 68(1): 9-23, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23723009

RESUMO

Acid-sensing ion channels (ASICs) from dorsal root ganglia (DRG) neurons are proton sensors during ischemia and inflammation. Little is known about their role in type 1 diabetes (T1D). Our study was focused on ASICs alterations determined by advanced T1D status. Primary neuronal cultures were obtained from lower (T9-T12) thoracic DRG neurons from Balb/c and TCR-HA(+/-)/Ins-HA(+/-) diabetic male mice (16 weeks of age). Patch-clamp recordings indicate a change in the number of small DRG neurons presenting different ASIC-type currents. Multiple molecular sites of ASICs are distinctly affected in T1D, probably due to particular steric constraints for glycans accessibility to the active site: (i) ASIC1 current inactivates faster, while ASIC2 is slower; (ii) PcTx1 partly reverts diabetes effects against ASIC1- and ASIC2-inactivations; (iii) APETx2 maintains unaltered potency against ASIC3 current amplitude, but slows ASIC3 inactivation. Immunofluorescence indicates opposite regulation of different ASIC transcripts while qRT-PCR shows that ASIC mRNA ranking (ASIC2 > ASIC1 > ASIC3) remains unaltered. In conclusion, our study has identified biochemical and biophysical ASIC changes in lower thoracic DRG neurons due to advanced T1D. As hypoalgesia is present in advanced T1D, ASICs alterations might be the cause or the consequence of diabetic insensate neuropathy.


Assuntos
Canais Iônicos Sensíveis a Ácido/metabolismo , Diabetes Mellitus Tipo 1/etiologia , Gânglios Espinais/citologia , Neurônios/fisiologia , Canais Iônicos Sensíveis a Ácido/genética , Animais , Células Cultivadas , Venenos de Cnidários/farmacologia , Diabetes Mellitus Tipo 1/metabolismo , Genótipo , Insulina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Neurônios/citologia , Neurônios/efeitos dos fármacos , Técnicas de Patch-Clamp , Peptídeos/farmacologia , RNA Mensageiro/metabolismo , Venenos de Aranha/farmacologia
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