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1.
Int J Mol Sci ; 24(3)2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36769284

RESUMO

The Hedgehog (HH) signaling network is one of the main regulators of invertebrate and vertebrate embryonic development. Along with other networks, such as NOTCH and WNT, HH signaling specifies both the early patterning and the polarity events as well as the subsequent organ formation via the temporal and spatial regulation of cell proliferation and differentiation. However, aberrant activation of HH signaling has been identified in a broad range of malignant disorders, where it positively influences proliferation, survival, and therapeutic resistance of neoplastic cells. Inhibitors targeting the HH pathway have been tested in preclinical cancer models. The HH pathway is also overactive in other blood malignancies, including T-cell acute lymphoblastic leukemia (T-ALL). This review is intended to summarize our knowledge of the biological roles and pathophysiology of the HH pathway during normal T-cell lymphopoiesis and in T-ALL. In addition, we will discuss potential therapeutic strategies that might expand the clinical usefulness of drugs targeting the HH pathway in T-ALL.


Assuntos
Proteínas Hedgehog , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Humanos , Proteínas Hedgehog/metabolismo , Linfopoese , Linfócitos T/metabolismo , Transdução de Sinais/fisiologia
2.
Int J Mol Sci ; 24(5)2023 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-36902375

RESUMO

Neuromuscular junctions (NMJs) are specialized synapses, crucial for the communication between spinal motor neurons (MNs) and skeletal muscle. NMJs become vulnerable in degenerative diseases, such as muscle atrophy, where the crosstalk between the different cell populations fails, and the regenerative ability of the entire tissue is hampered. How skeletal muscle sends retrograde signals to MNs through NMJs represents an intriguing field of research, and the role of oxidative stress and its sources remain poorly understood. Recent works demonstrate the myofiber regeneration potential of stem cells, including amniotic fluid stem cells (AFSC), and secreted extracellular vesicles (EVs) as cell-free therapy. To study NMJ perturbations during muscle atrophy, we generated an MN/myotube co-culture system through XonaTM microfluidic devices, and muscle atrophy was induced in vitro by Dexamethasone (Dexa). After atrophy induction, we treated muscle and MN compartments with AFSC-derived EVs (AFSC-EVs) to investigate their regenerative and anti-oxidative potential in counteracting NMJ alterations. We found that the presence of EVs reduced morphological and functional in vitro defects induced by Dexa. Interestingly, oxidative stress, occurring in atrophic myotubes and thus involving neurites as well, was prevented by EV treatment. Here, we provided and validated a fluidically isolated system represented by microfluidic devices for studying human MN and myotube interactions in healthy and Dexa-induced atrophic conditions-allowing the isolation of subcellular compartments for region-specific analyses-and demonstrated the efficacy of AFSC-EVs in counteracting NMJ perturbations.


Assuntos
Líquido Amniótico , Vesículas Extracelulares , Humanos , Junção Neuromuscular/patologia , Atrofia Muscular/patologia , Músculo Esquelético/patologia , Células-Tronco
3.
Int J Mol Sci ; 23(9)2022 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-35563358

RESUMO

BACKGROUND: Neuroinflammation is involved in neuronal cell death that occurs in neurodegenerative diseases such as Alzheimer's disease (AD). Microglia play important roles in regulating the brain amyloid beta (Aß) levels, so immunomodulatory properties exerted by mesenchymal stem cells may be exploited to treat this pathology. The evidence suggests that the mechanism of action of human amniotic fluid stem cells (hAFSCs) is through their secretome, which includes exosomes (exo). METHODS: We examined the effect of exosomes derived from human amniotic fluid stem cells (hAFSCs-exo) on activated BV-2 microglia cells by lipopolysaccharide (LPS) as a neuroinflammation model. To investigate the exo effect on the interplay between AD neurons and microglia, SH-SY5Y neuroblastoma cells treated with Aß were exposed to a conditioned medium (CM) obtained from activated BV-2 or co-culture systems. RESULTS: We found that the upregulation of the markers of pro-inflammatory microglia was prevented when exposed to hAFSC-exo whereas the markers of the anti-inflammatory macrophage phenotype were not affected. Interestingly, the hAFSC-exo pretreatment significantly inhibited the oxidative stress rise and apoptosis occurring in the neurons in presence of both microglia and Aß. CONCLUSION: We demonstrated that hAFSC-exo mitigated an inflammatory injury caused by microglia and significantly recovered the neurotoxicity, suggesting that hAFSC-exo may be a potential therapeutic agent for inflammation-related neurological conditions, including AD.


Assuntos
Doença de Alzheimer , Exossomos , Células-Tronco Mesenquimais , Doença de Alzheimer/metabolismo , Líquido Amniótico/metabolismo , Peptídeos beta-Amiloides/metabolismo , Exossomos/metabolismo , Humanos , Células-Tronco Mesenquimais/metabolismo , Microglia/metabolismo , Neurônios/metabolismo
4.
Int J Mol Sci ; 22(1)2020 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-33375177

RESUMO

Background-Osteoporosis is characterized by defects in both quality and quantity of bone tissue, which imply high susceptibility to fractures with limitations of autonomy. Current therapies for osteoporosis are mostly concentrated on how to inhibit bone resorption but give serious adverse effects. Therefore, more effective and safer therapies are needed that even encourage bone formation. Here we examined the effect of extracellular vesicles secreted by human amniotic fluid stem cells (AFSC) (AFSC-EV) on a model of osteoporosis in vitro. Methods-human AFSC-EV were added to the culture medium of a human pre-osteoblast cell line (HOB) induced to differentiate, and then treated with dexamethasone as osteoporosis inducer. Aspects of differentiation and viability were assessed by immunofluorescence, Western blot, mass spectrometry, and histological assays. Since steroids induce oxidative stress, the levels of reactive oxygen species and of redox related proteins were evaluated. Results-AFSC-EV were able to ameliorate the differentiation ability of HOB both in the case of pre-osteoblasts and when the differentiation process was affected by dexamethasone. Moreover, the viability was increased and parallelly apoptotic markers were reduced. The presence of EV positively modulated the redox unbalance due to dexamethasone. Conclusion-these findings demonstrated that EV from hAFSC have the ability to recover precursor cell potential and delay local bone loss in steroid-related osteoporosis.


Assuntos
Líquido Amniótico/citologia , Vesículas Extracelulares/metabolismo , Osteoporose/metabolismo , Células-Tronco/metabolismo , Western Blotting , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Dexametasona/farmacologia , Feminino , Glutationa/metabolismo , Humanos , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Osteoporose/induzido quimicamente , Gravidez , Espécies Reativas de Oxigênio/metabolismo , Esteroides
5.
Int J Mol Sci ; 20(3)2019 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-30754633

RESUMO

The present study is the second step (concerning normal diet restoration) of the our previous study (concerning the calcium-free diet) to determine whether normal diet restoration, with/without concomitant PTH (1-34) administration, can influence amounts and deposition sites of the total bone mass. Histomorphometric evaluations and immunohistochemical analysis for Sclerostin expression were conducted on the vertebral bodies and femurs in the rat model. The final goals are (i) to define timing and manners of bone mass changes when calcium is restored to the diet, (ii) to analyze the different involvement of the two bony architectures having different metabolism (i.e., trabecular versus cortical bone), and (iii) to verify the eventual role of PTH (1-34) administration. Results evidenced the greater involvement of the trabecular bone with respect to the cortical bone, in response to different levels of calcium content in the diet, and the effect of PTH, mostly in the recovery of trabecular bony architecture. The main findings emerged from the present study are (i) the importance of the interplay between mineral homeostasis and skeletal homeostasis in modulating and guiding bone's response to dietary/metabolic alterations and (ii) the evidence that the more involved bony architecture is the trabecular bone, the most susceptible to the dynamical balance of the two homeostases.


Assuntos
Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Cálcio da Dieta/administração & dosagem , Homeostase , Hormônio Paratireóideo/administração & dosagem , Animais , Biomarcadores , Análise Química do Sangue , Peso Corporal/efeitos dos fármacos , Densidade Óssea/efeitos dos fármacos , Osso Esponjoso/efeitos dos fármacos , Osso Esponjoso/metabolismo , Suplementos Nutricionais , Imunofluorescência , Homeostase/efeitos dos fármacos , Humanos , Imuno-Histoquímica , Ratos
6.
Int J Mol Sci ; 20(22)2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31703269

RESUMO

Commercial gonadotropin-releasing hormone (GnRH) antagonists differ by 1-2 amino acids and are used to inhibit gonadotropin production during assisted reproduction technologies (ART). In this study, potencies of three GnRH antagonists, Cetrorelix, Ganirelix and Teverelix, in inhibiting GnRH-mediated intracellular signaling, were compared in vitro. GnRH receptor (GnRHR)-transfected HEK293 and neuroblastoma-derived SH-SY5Y cell lines, as well as mouse pituitary LßT2 cells endogenously expressing the murine GnRHR, were treated with GnRH in the presence or absence of the antagonist. We evaluated intracellular calcium (Ca2+) and cAMP increases, cAMP-responsive element binding-protein (CREB) and extracellular-regulated kinase 1 and 2 (ERK1/2) phosphorylation, ß-catenin activation and mouse luteinizing-hormone ß-encoding gene (Lhb) transcription by bioluminescence resonance energy transfer (BRET), Western blotting, immunostaining and real-time PCR as appropriate. The kinetics of GnRH-induced Ca2+ rapid increase revealed dose-response accumulation with potency (EC50) of 23 nM in transfected HEK293 cells, transfected SH-SY5Y and LßT2 cells. Cetrorelix inhibited the 3 × EC50 GnRH-activated calcium signaling at concentrations of 1 nM-1 µM, demonstrating higher potency than Ganirelix and Teverelix, whose inhibitory doses fell within the 100 nM-1 µM range in both transfected HEK293 and SH-SY5Y cells in vitro. In transfected SH-SY5Y, Cetrorelix was also significantly more potent than other antagonists in reducing GnRH-mediated cAMP accumulation. All antagonists inhibited pERK1/2 and pCREB activation at similar doses, in LßT2 and transfected HEK293 cells treated with 100 nM GnRH. Although immunostainings suggested that Teverelix could be less effective than Cetrorelix and Ganirelix in inhibiting 1 µM GnRH-induced ß-catenin activation, Lhb gene expression increase occurring upon LßT2 cell treatment by 1 µM GnRH was similarly inhibited by all antagonists. To conclude, this study has demonstrated Cetrorelix-, Ganirelix- and Teverelix-specific biased effects at the intracellular level, not affecting the efficacy of antagonists in inhibiting Lhb gene transcription.


Assuntos
Sinalização do Cálcio/efeitos dos fármacos , Cálcio/metabolismo , Hormônio Liberador de Gonadotropina/antagonistas & inibidores , Antagonistas de Hormônios/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Receptores LHRH/metabolismo , Animais , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Hormônio Liberador de Gonadotropina/metabolismo , Células HEK293 , Humanos , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo
7.
Int J Mol Sci ; 19(5)2018 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-29772687

RESUMO

Accumulating evidence suggests that metformin, used as an antidiabetic drug, possesses anti-cancer properties. Metformin reduced the incidence and growth of experimental tumors in vivo. In a randomized clinical trial among nondiabetic patients, metformin treatment significantly decreased the number of aberrant crypt foci compared to the untreated group with a follow-up of 1 month. In our study, HT29 cells were treated with graded concentrations of metformin, 10 mM/25 mM/50 mM for 24/48 h. We performed immunofluorescence experiments by means of confocal microscopy and western blot analysis to evaluate a panel of factors involved in apoptotic/autophagic processes and oxidative stress response. Moreover, HT29 cells treated with metformin were analyzed by a flow cytometry assay to detect the cell apoptotic rate. The results demonstrate that metformin exerts growth inhibitory effects on cultured HT29 cells by increasing both apoptosis and autophagy; moreover, it affects the survival of cultured cells inhibiting the transcriptional activation of Nuclear factor E2-related factor 2 (NRF-2) and nuclear factor-kappa B (NF-κB). The effects of metformin on HT29 cells were dose- and time-dependent. These results are very intriguing since metformin is emerging as a multi-faceted drug: It has a good safety profile and is associated with low cost and might be a promising candidate for the prevention or the treatment of colorectal cancer.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Metformina/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Biomarcadores , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/patologia , Relação Dose-Resposta a Droga , Células HT29 , Humanos , Hipoglicemiantes/farmacologia , Imuno-Histoquímica , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/metabolismo
8.
J Anat ; 230(1): 75-84, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27523886

RESUMO

The timetable of effects on bone repair of the active fraction-parathyroid hormone, PTH(1-34), was analytically investigated from the morphometric viewpoint in 3-month-old male Sprague-Dawley rats, whose femurs were drilled at mid-diaphyseal level (transcortical holes). The animals were divided into groups with/without PTH(1-34) administration, and sacrificed at different times (10, 28, 45 days after surgery). The observations reported here need to be framed in the context of our previous investigations regarding bone histogenesis (Ferretti et al. Anat Embryol. 2002; 206: 21-29) in which we demonstrated the occurrence of two successive bone-forming processes during both skeletal organogenesis and bone repair, i.e. static and dynamic osteogenesis: the former (due to stationary osteoblasts, haphazardly grouped in cords) producing preliminary bad quality trabecular bone, the latter (due to typical polarized osteoblasts organized in ordered movable laminae) producing mechanically valid bone tissue. The primary function of static osteogenesis is to provide a rigid scaffold containing osteocytes (i.e. mechano-sensors) for osteoblast laminae acting in dynamic osteogenesis. In the present work, histomorphometric analysis revealed that, already 10 days after drilling, despite the holes being temporarily filled by the same amount of newly formed trabecular bone by static osteogenesis independently of the treatment, the extent of the surface of movable osteoblast-laminae (covering the trabecular surface) was statistically higher in animals submitted to PTH(1-34) administration than in control ones; this datum strongly suggests the effect of PTH(1-34) alone in anticipating the occurrence of dynamic osteogenesis involved in the production of good quality bone (with more ordered collagen texture) more suitable for loading. This study could be crucial in further translational clinical research in humans for defining the best therapeutic strategies to be applied in recovering severe skeletal lesions, particularly as regards the time of PTH(1-34) administration.


Assuntos
Fêmur/efeitos dos fármacos , Fêmur/patologia , Osteogênese/efeitos dos fármacos , Hormônio Paratireóideo/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/patologia , Osso e Ossos/fisiologia , Fêmur/fisiologia , Masculino , Osteogênese/fisiologia , Ratos , Ratos Sprague-Dawley , Resultado do Tratamento , Cicatrização/fisiologia
9.
J Anat ; 231(6): 823-834, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28925539

RESUMO

Hitherto, the role of the osteocyte as transducer of mechanical stimuli into biological signals is far from settled. In this study, we used an appropriate model represented by the cortex of Xenopus laevis long bone diaphysis lacking (unlike the mammalian one) of vascular structures and containing only osteocytes inside the bone matrix. These structural features allow any change of protein profile that might be observed upon different experimental conditions, such as bone adaptation to stress/mechanical loading, to be ascribed specifically to osteocytes. The study was conducted by combining ultrastructural observations and two-dimensional electrophoresis for proteomic analysis. The osteocyte population was extracted from long bones of lower limbs of amphibian skeletons after different protocols (free and forced swimming). The experiments were performed on 210 frogs subdivided into five trials, each including free swimming frogs (controls) and frogs submitted to forced swimming (stressed). The stressed groups were obliged to swim (on movable spheres covering the bottom of a pool on a vibrating plate) continuously for 8 h, and killed 24 h later along with the control groups. Long bones free of soft tissues (periosteum, endosteum and bone marrow), as well as muscles of posterior limbs, were processed and analyzed for proteins differentially expressed or phosphorylated between the two sample groups. The comparative analysis showed that protein phosphorylation profiles differ between control and stressed groups. In particular, we found in long bones of stressed samples that both Erk1/2 and Akt are hyperphosphorylated; moreover, the different phosphorylation of putative Akt substrates (recognized by specific Akt phosphosubstrates-antibody) in stressed vs. control samples clearly demonstrated that Akt signaling is boosted by forced swimming (leading to an increase of mechanical stress) of amphibian long bones. In parallel, we found in posterior limb muscles that the expression of heat shock protein HSP27 and HSP70 stress markers increased upon the forced swimming condition. Because the cortexes of frog long bones are characterized by the presence of only osteocytes, all our results establish the suitability of the X. laevis animal model to study the bone response to stress conditions mediated by this cell type and pave the way for further analysis of the signaling pathways involved in these signal transduction mechanisms.


Assuntos
Osso e Ossos/fisiologia , Modelos Animais , Osteócitos/fisiologia , Xenopus laevis/fisiologia , Animais , Proteômica , Estresse Mecânico
10.
Metab Eng ; 26: 1-16, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25149266

RESUMO

Rifamycins are mainstay agents in treatment of many widespread diseases, but how an improved rifamycin producer can be created is still incompletely understood. Here, we describe a comparative genomic approach to investigate the mutational patterns introduced by the classical mutate-and-screen method in the genome of an improved rifamycin producer. Comparing the genome of the rifamycin B overproducer Amycolatopsis mediterranei HP-130 with those of the reference strains A. mediterranei S699 and U32, we identified 250 variations, affecting 227 coding sequences (CDS), 109 of which were HP-130-specific since they were absent in both S699 and U32. Mutational and transcriptional patterns indicated a series of genomic manipulations that not only proved the causative effect of mutB2 (coding for methylmalonyl-CoA mutase large subunit) and argS2 (coding for arginyl tRNA synthetase) mutations on the overproduction of rifamycin, but also constituted a rational strategy to genetically engineer a reference strain into an overproducer.


Assuntos
Actinobacteria/genética , Arginina-tRNA Ligase/genética , Genoma Bacteriano/genética , Engenharia Metabólica/métodos , Metilmalonil-CoA Mutase/genética , Rifamicinas/metabolismo , Actinobacteria/classificação , Mapeamento Cromossômico/métodos , Hibridização Genômica Comparativa/métodos , Marcação de Genes/métodos , Melhoramento Genético/métodos , Especificidade da Espécie , Regulação para Cima/genética
11.
J Anat ; 224(6): 659-68, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24689495

RESUMO

To study the expression level of a panel of pro/anti-apoptotic factors and inflammation-related receptors in chondral fragments from patients undergoing surgical treatment for intra-articular calcaneal fractures, cartilage fragments were retrieved from calcaneal fractures of 20 patients subjected to surgical treatment. Primary cultures were performed using chondral fragments from fractured and control patients. Chondrocyte cultures from each patient of the fractured and control groups were subjected to immunofluorescence staining and quantitatively analyzed under confocal microscopy. Proteins extracted from the cultured chondrocytes taken from the fractured and control groups were processed for Western blot experiments and densitometric analysis. The percentage of apoptotic cells was determined using the cleaved PARP-1 antibody. The proportion of labelled cells was 35% for fractured specimens, compared with 7% for control samples. Quantification of caspase-3 active and Bcl-2 proteins in chondrocyte cultures showed a significant increase of the apoptotic process in fractured specimens compared with control ones. Fractured chondrocytes were positively stained for ChemR23 with statistically significant differences with respect to control samples. Densitometric evaluation of the immunoreactive bands confirmed these observations. Human articular chondrocytes obtained from patients with intra-articular calcaneal fractures express higher levels of pivotal pro-apoptotic factors, and of the chemo-attractive receptor ChemR23, compared with control cultures. On the basis of these observations, the authors hypothesize that consistent prolonged chondrocyte death, associated with the persistence of high levels of pro-inflammatory factors, could enhance the deterioration of cartilage tissue with consequent development of post-traumatic arthritis following intra-articular bone fracture.


Assuntos
Apoptose/fisiologia , Calcâneo/lesões , Condrócitos/metabolismo , Fraturas Ósseas/metabolismo , Receptores de Quimiocinas/biossíntese , Adulto , Western Blotting , Cartilagem Articular/metabolismo , Cartilagem Articular/patologia , Separação Celular , Células Cultivadas , Condrócitos/patologia , Feminino , Imunofluorescência , Fraturas Ósseas/patologia , Humanos , Masculino , Microscopia Confocal , Pessoa de Meia-Idade , Regulação para Cima , Adulto Jovem
12.
ScientificWorldJournal ; 2013: 630869, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24348178

RESUMO

Promyelocytic leukemia zinc finger protein (PLZF) is a protein involved in various signaling, growth regulatory, and differentiation pathways, including development/function of some T cells. Here, we aimed at the detection of PLZF during colorectal carcinogenesis, using immunofluorescence, and at the evaluation of the colocalization of PLZF with CD2 and CD56 positive cells (T, γ δ , NK, and NKT cells), using confocal-microscopy, along colorectal carcinogenesis, since its earliest stages, that is, dysplastic aberrant crypt foci (ACF). Furthermore, we analyzed PLZF in the normal colonic mucosa (NM) according to anthropometric parameters of the subject. NM exhibited strong CD56 fluorescent staining. This infiltration was lost in both ACF and colorectal carcinoma (CRC), while PLZF presence increased from NM to ACF and CRC. Strong association was found between CD56+ colonic mucosa cell infiltration and body mass index. Interestingly, an increased stromal PLZF-reactivity was present in NM of obese subjects. This study shows that overexpression of PLZF and exclusion of NK cells in dysplastic microenvironment are very early events in the stepwise sequence leading to CRC and that lower levels of CD56+ cells in NM, together with increased levels of PLZF+ cells, can be a reflection of colon cancer risk due to obesity.


Assuntos
Tamanho Corporal , Transformação Celular Neoplásica/metabolismo , Colo/metabolismo , Neoplasias Colorretais/etiologia , Mucosa Intestinal/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Adulto , Idoso , Biomarcadores , Antígenos CD2/metabolismo , Antígeno CD56/metabolismo , Transformação Celular Neoplásica/genética , Colonoscopia , Neoplasias Colorretais/patologia , Feminino , Expressão Gênica , Humanos , Imuno-Histoquímica , Mucosa Intestinal/patologia , Fatores de Transcrição Kruppel-Like/genética , Masculino , Microscopia Confocal , Pessoa de Meia-Idade , Proteína com Dedos de Zinco da Leucemia Promielocítica , Ligação Proteica , Risco
13.
Bone ; 173: 116790, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37182755

RESUMO

The present letter to editor comments the manuscript entitled "Targeting osteocytes vs osteoblasts" by Y. Kitase and M. Prideaux, where we underlie the importance morphology in choosing Cre experimental models for targeting osteoblasts vs osteocytes.


Assuntos
Osteoblastos , Osteócitos , Integrases , Osteogênese
14.
Stem Cell Rev Rep ; 19(8): 2994-2995, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37721658

RESUMO

The present letter to editor comments on the manuscript entitled "Assembling the Puzzle Pieces. Insights for in Vitro Bone Remodeling" by O. Krasnova & I. Neganova; in this context, we underlie the importance of in vivo models to corroborate in vitro bone remodeling systems.


Assuntos
Remodelação Óssea
15.
Biology (Basel) ; 12(9)2023 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-37759618

RESUMO

We are witnessing the revival of the CAM model, which has already used been in the past by several researchers studying angiogenesis and anti-cancer drugs and now offers a refined model to fill, in the translational meaning, the gap between in vitro and in vivo studies. It can be used for a wide range of purposes, from testing cytotoxicity, pharmacokinetics, tumorigenesis, and invasion to the action mechanisms of molecules and validation of new materials from tissue engineering research. The CAM model is easy to use, with a fast outcome, and makes experimental research more sustainable since it allows us to replace, reduce, and refine pre-clinical experimentation ("3Rs" rules). This review aims to highlight some unique potential that the CAM-assay presents; in particular, the authors intend to use the CAM model in the future to verify, in a microenvironment comparable to in vivo conditions, albeit simplified, the angiogenic ability of functionalized 3D constructs to be used in regenerative medicine strategies in the recovery of skeletal injuries of critical size (CSD) that do not repair spontaneously. For this purpose, organotypic cultures will be planned on several CAMs set up in temporal sequences, and a sort of organ model for assessing CSD will be utilized in the CAM bioreactor rather than in vivo.

16.
Biomedicines ; 11(3)2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36979634

RESUMO

It's known that a magnesium (Mg)-deficient diet is associated with an increased risk of osteoporosis. The aim of this work is to investigate, by a histological approach, the effects of a Mg-deprived diet on the bone of 8-weeks-old C57BL/6J male mice. Treated and control mice were supplied with a Mg-deprived or normal diet for 8 weeks, respectively. Body weight, serum Mg concentration, expression of kidney magnesiotropic genes, and histomorphometry on L5 vertebrae, femurs, and tibiae were evaluated. Body weight gain and serum Mg concentration were significantly reduced, while a trend toward increase was found in gene expression in mice receiving the Mg-deficient diet, suggesting the onset of an adaptive response to Mg depletion. Histomorphometric parameters on the amount of trabecular and cortical bone, number of osteoclasts, and thickness of the growth plate in femoral distal and tibial proximal metaphyses did not differ between groups; these findings partially differ from most data present in the literature showing that animals fed a Mg-deprived diet develop bone loss and may be only in part explained by differences among the experimental protocols. However, the unexpected findings we recorded on bones could be attributed to genetic differences that may have developed after multiple generations of inbreeding.

17.
J Anat ; 221(4): 358-63, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22881388

RESUMO

Tendon lesions induce muscular atrophy, the nature of which has not yet been clearly related to lesion etiology and entity. In the present study, tendon and muscle alterations were assessed after experimental tendon lesion of the Infraspinatus muscle in young rats. The consequences of lesions differed on the basis of both extension and injured tissue vascularization, that is apoptosis and/or degeneration, differing mainly by energy demands: apoptosis requires high energy levels (proportional to vascular supply), but degeneration does not. It is well known that tendons are poorly supplied with blood compared with muscular masses, which are abundantly vascularized. Five weeks after tendon surgical section, tendon/muscle samples were taken for TUNEL and transmission electron microscopy. The structural results reported here identified different tendon/muscle alterations: degeneration of tendon without signs of apoptosis, and atrophy of muscle fibers due only to apoptosis. This led to the formulation of the following hypothetical sequence of events: a tendon lesion, not recovering quickly due to the poor tendon blood supply, results in degeneration of the injured tendon, which, in turn, induces a partial disuse of the muscle mass, which consequently atrophies (proportionally to the severity of tendon lesion) by striated muscular fiber apoptosis. The authors suggest that the different behavior of the two tissues depends on the marked difference in their vascularization.


Assuntos
Apoptose , Atrofia Muscular/patologia , Traumatismos dos Tendões/patologia , Animais , Modelos Animais de Doenças , Marcação In Situ das Extremidades Cortadas , Masculino , Microscopia Eletrônica de Transmissão , Músculo Esquelético/fisiopatologia , Músculo Esquelético/ultraestrutura , Ratos , Ratos Sprague-Dawley
18.
Calcif Tissue Int ; 90(3): 211-8, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22290503

RESUMO

Considering the pivotal role as bone mechanosensors ascribed to osteocytes in bone adaptation to mechanical strains, the present study analyzed whether a correlation exists between osteocyte apoptosis and bone remodeling in peculiar bones, such as human auditory ossicles and scleral ossicles of lower vertebrates, which have been shown to undergo substantial osteocyte death and trivial or no bone turnover after cessation of growth. The investigation was performed with a morphological approach under LM (by means of an in situ end-labeling technique) and TEM. The results show that a large amount of osteocyte apoptosis takes place in both auditory and scleral ossicles after they reach their final size. Additionally, no morphological signs of bone remodeling were observed. These facts suggest that (1) bone remodeling is not necessarily triggered by osteocyte death, at least in these ossicles, and (2) bone remodeling does not need to mechanically adapt auditory and scleral ossicles since they appear to be continuously submitted to stereotyped stresses and strains; on the contrary, during the resorption phase, bone remodeling might severely impair the mechanical resistance of extremely small bony segments. Thus, osteocyte apoptosis could represent a programmed process devoted to make stable, when needed, bone structure and mechanical resistance.


Assuntos
Estruturas Animais/fisiologia , Apoptose/fisiologia , Remodelação Óssea/fisiologia , Ossículos da Orelha/fisiologia , Osteócitos/fisiologia , Esclera/fisiologia , Adolescente , Adulto , Idoso , Estruturas Animais/ultraestrutura , Animais , Evolução Biológica , Embrião de Galinha , Galinhas , Ossículos da Orelha/ultraestrutura , Feminino , Humanos , Lagartos , Masculino , Pessoa de Meia-Idade , Osteócitos/ultraestrutura , Esclera/ultraestrutura , Adulto Jovem
19.
J Bone Miner Metab ; 30(6): 619-29, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22828874

RESUMO

This study analyzes the effects of different doses of ferutinin on bone loss caused by estrogen deficiency in ovariectomized rats, in comparison with estradiol benzoate. Thirty female Sprague-Dawley rats were ovariectomized and treated for 30 days from the day after ovariectomy. Static/dynamic histomorphometric analyses were performed on trabecular and cortical bone of lumbar vertebrae and femurs. Very low weight increments were recorded only in all F-OVX groups, with respect to the others. Although the great differences in weight, that could imply a decrease of bone mass in F-OVX groups compared to the control ovariectomized group (C-OVX), trabecular bone in lumbar vertebrae did not show significant differences, suggesting that ferutinin, opposing estrogen deficiency, inhibits bone resorption. Newly formed cortical bone was always low in all F-OVX groups and high in C-OVX, suggesting that it is mainly devoted in answering mechanical demands. In contrast, in distal femoral metaphyses, trabecular bone was reduced and the number of osteoclasts was increased in C-OVX with respect to all other groups, suggesting that it is mainly devoted in answering metabolic demands; moreover, ferutinin dose of 2 mg/kg seemed to be more effective than the lower doses used and estrogens, particularly in those skeletal regions with higher metabolic activity. Our results suggest that the role of ferutinin in preventing osteoporosis caused by estrogen deficiency is expressed in decreasing bone erosion; moreover, in all F-OVX groups bone turnover is very low and seems correlated to the trivial body weight increase, which, in turn, depends on ferutinin treatment.


Assuntos
Benzoatos/administração & dosagem , Reabsorção Óssea/prevenção & controle , Cicloeptanos/administração & dosagem , Osteogênese/efeitos dos fármacos , Osteoporose/tratamento farmacológico , Sesquiterpenos/administração & dosagem , Animais , Compostos Bicíclicos com Pontes/administração & dosagem , Estrogênios/deficiência , Feminino , Ovariectomia , Ratos , Ratos Sprague-Dawley
20.
Resuscitation ; 173: 182-183, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35369972

RESUMO

The present letter to editor comments the manuscript "Sex Disparities in Management and Outcomes of Cardiac Arrest Complicating Acute Myocardial Infarction in the United States." by Verghese D and coworkers." presenting some comment on sex disparities in treatment and the need for an action on medical school.


Assuntos
Parada Cardíaca , Infarto do Miocárdio , Parada Cardíaca/terapia , Humanos , Infarto do Miocárdio/complicações , Faculdades de Medicina , Estados Unidos
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