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1.
Eur J Immunol ; 53(12): e2350454, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37621208

RESUMEN

Human immune system (HIS) mice provide a model to study human immune responses in vivo. Currently available HIS mouse models may harbor mouse Fc Receptor (FcR)-expressing cells that exert potent effector functions following administration of human Ig. Previous studies showed that the ablation of the murine FcR gamma chain (FcR-γ) results in loss of antibody-dependent cellular cytotoxicity and antibody-dependent cellular phagocytosis in vivo. We created a new FcR-γ-deficient HIS mouse model to compare host (mouse) versus graft (human) effects underlying antibody-mediated immune responses in vivo. FcR-γ-deficient HIS recipients lack expression and function of mouse activating FcRs and can be stably and robustly reconstituted with human immune cells. By screening blood B-cell depletion by rituximab Ig variants, we found that human FcγRs-mediated IgG1 effects, whereas mouse activating FcγRs were dominant in IgG4 effects. Complement played a role as an IgG1 variant (IgG1 K322A) lacking complement binding activity was largely ineffective. Finally, we provide evidence that FcγRIIIA on human NK cells could mediate complement-independent B-cell depletion by IgG1 K322A. We anticipate that our FcR-γ-deficient HIS model will help clarify mechanisms of action of exogenous administered human antibodies in vivo.


Asunto(s)
Receptores Fc , Receptores de IgG , Humanos , Ratones , Animales , Receptores de IgG/genética , Inmunoglobulina G , Citotoxicidad Celular Dependiente de Anticuerpos , Macrófagos , Proteínas del Sistema Complemento , Inmunidad Adaptativa
2.
Epilepsy Res ; 193: 107160, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37187037

RESUMEN

PURPOSE: KCNQ2 neonatal developmental and epileptic encephalopathy (NEO-DEE) is characterized by intractable seizures accompanied by an abnormal neurodevelopment. In a mouse model of NEO-DEE carrying the p.(Thr274Met) variant of Kcnq2, spontaneous generalized seizures occur unexpectedly preventing controlled studies and highlighting the necessity for a customized setup to trigger seizures on demand. We aimed to obtain a stable and objective read-out to control the efficacy of new antiepileptic drugs or to test seizure susceptibility. We developed a protocol to trigger ultrasound-induced seizures (UIS) on demand in this model. METHODS: We tested the ability of our protocol to induce seizures at four developmental stages in the Kcnq2p.(Thr274Met/+) mouse model. We mapped the activated brain regions using c-fos protein labeling 2 h after seizure induction. RESULTS: We show that the UIS have the same phenotypic expression and the same severity as spontaneous generalized seizures (SGS) in the Kcnq2-NEO-DEE mouse model. The developmental period during which mice exhibit SGS corresponds to the period during which Kcnq2p.(Thr274Met/+) mice are the most susceptible to US. C-fos labeling reveals a subset of 6 brain regions activated 2 h after the induction of the seizure. The same regions were identified in the context of seizure induction in other rodent models. CONCLUSION: This study provides a non-invasive and easy to use method to induce seizures in a Kcnq2-NEO-DEE mouse model and documents early neuronal activation in specific brain regions. This method can be used to test the efficacy of new antiepileptic approaches for this intractable form of genetic epilepsy.


Asunto(s)
Encefalopatías , Epilepsia Generalizada , Epilepsia , Ratones , Animales , Mutación , Convulsiones/diagnóstico por imagen , Convulsiones/genética , Epilepsia/genética , Encefalopatías/genética , Anticonvulsivantes , Modelos Animales de Enfermedad , Canal de Potasio KCNQ2/genética , Proteínas del Tejido Nervioso/metabolismo
3.
Dev Med Child Neurol ; 65(2): 162-170, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36056801

RESUMEN

Rett syndrome (RTT) is an X-linked neurogenetic disorder caused by mutations of the MECP2 (methyl-CpG-binding protein 2) gene. Over two decades of work established MeCP2 as a protein with pivotal roles in the regulation of the epigenome, neuronal physiology, synaptic maintenance, and behaviour. Given the genetic aetiology of RTT and the proof of concept of its reversal in a mouse model, considerable efforts have been made to design therapeutic approaches to re-express MeCP2. By being at the forefront of the development of innovative gene therapies, research on RTT is of paramount importance for the treatment of monogenic neurological diseases. Here we discuss the recent advances and challenges of promising genetic strategies for the treatment of RTT including gene replacement therapies, gene/RNA editing strategies, and reactivation of the silenced X chromosome. WHAT THIS PAPER ADDS: Recent advances shed light on the promises of gene replacement therapy with new vectors designed to control the levels of MeCP2 expression. New developments in DNA/RNA editing approaches or reactivation of the silenced X chromosome open the possibility to re-express the native MeCP2 locus at endogenous levels. Current strategies still face limitations in transduction efficiency and future work is needed to improve brain delivery.


Asunto(s)
Arteterapia , Síndrome de Rett , Ratones , Animales , Humanos , Síndrome de Rett/terapia , Síndrome de Rett/tratamiento farmacológico , Proteína 2 de Unión a Metil-CpG/genética , Encéfalo/metabolismo , Mutación , Neuronas
4.
Nat Immunol ; 23(9): 1317-1323, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35999393

RESUMEN

An orchestrated cellular network, including adaptive lymphocytes and group 3 innate lymphoid cells (ILC3s), maintains intestinal barrier integrity and homeostasis. T cells can monitor environmental insults through constitutive circulation, scanning tissues and forming immunological contacts, a process named immunosurveillance. In contrast, the dynamics of intestinal ILC3s are unknown. Using intravital imaging, we observed that villus ILC3s were largely immotile at steady state but acquired migratory 'patrolling' attributes and enhanced cytokine expression in response to inflammation. We showed that T cells, the chemokine CCL25 and bacterial ligands regulated intestinal ILC3 behavior and that loss of patrolling behavior by interleukin-22 (IL-22)-producing ILC3s altered the intestinal barrier through increased epithelial cell death. Collectively, we identified notable differences between the behavior of ILC3s and T cells, with a prominent adaptation of intestinal ILC3s toward mucosal immunosurveillance after inflammation.


Asunto(s)
Inmunidad Innata , Linfocitos , Citocinas/metabolismo , Humanos , Inflamación/metabolismo , Mucosa Intestinal , Ligandos
5.
Nat Commun ; 13(1): 4344, 2022 07 27.
Artículo en Inglés | MEDLINE | ID: mdl-35896601

RESUMEN

Innate lymphoid cells (ILCs) include cytotoxic natural killer cells and distinct groups of cytokine-producing innate helper cells which participate in immune defense and promote tissue homeostasis. Circulating human ILC precursors (ILCP) able to generate all canonical ILC subsets via multi-potent or uni-potent intermediates according to our previous work. Here we show potential cooperative roles for the Notch and IL-23 signaling pathways for human ILC differentiation from blood ILCP using single cell cloning analyses and validate these findings in patient samples with rare genetic deficiencies in IL12RB1 and RORC. Mechanistically, Notch signaling promotes upregulation of the transcription factor RORC, enabling acquisition of Group 1 (IFN-γ) and Group 3 (IL-17A, IL-22) effector functions in multi-potent and uni-potent ILCP. Interfering with RORC or signaling through its target IL-23R compromises ILC3 effector functions but also generally suppresses ILC production from multi-potent ILCP. Our results identify a Notch->RORC- > IL-23R pathway which operates during human ILC differentiation. These observations may help guide protocols to expand functional ILC subsets in vitro with an aim towards novel ILC therapies for human disease.


Asunto(s)
Inmunidad Innata , Linfocitos , Diferenciación Celular , Humanos , Interleucina-23 , Células Asesinas Naturales , Células Progenitoras Linfoides/fisiología , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/genética , Receptores Notch/metabolismo
6.
Nat Immunol ; 22(11): 1367-1374, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34686862

RESUMEN

Group 2 innate lymphoid cells (ILC2s) represent innate homologs of type 2 helper T cells (TH2) that participate in immune defense and tissue homeostasis through production of type 2 cytokines. While T lymphocytes metabolically adapt to microenvironmental changes, knowledge of human ILC2 metabolism is limited, and its key regulators are unknown. Here, we show that circulating 'naive' ILC2s have an unexpected metabolic profile with a higher level of oxidative phosphorylation (OXPHOS) than natural killer (NK) cells. Accordingly, ILC2s are severely reduced in individuals with mitochondrial disease (MD) and impaired OXPHOS. Metabolomic and nutrient receptor analysis revealed ILC2 uptake of amino acids to sustain OXPHOS at steady state. Following activation with interleukin-33 (IL-33), ILC2s became highly proliferative, relying on glycolysis and mammalian target of rapamycin (mTOR) to produce IL-13 while continuing to fuel OXPHOS with amino acids to maintain cellular fitness and proliferation. Our results suggest that proliferation and function are metabolically uncoupled in human ILC2s, offering new strategies to target ILC2s in disease settings.


Asunto(s)
Proliferación Celular , Citocinas/metabolismo , Metabolismo Energético , Inmunidad Innata , Activación de Linfocitos , Enfermedades Mitocondriales/metabolismo , Células Th2/metabolismo , Aminoácidos de Cadena Ramificada/metabolismo , Arginina/metabolismo , Estudios de Casos y Controles , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Metabolismo Energético/efectos de los fármacos , Humanos , Inmunidad Innata/efectos de los fármacos , Interleucina-33/farmacología , Activación de Linfocitos/efectos de los fármacos , Mitocondrias/metabolismo , Enfermedades Mitocondriales/diagnóstico , Enfermedades Mitocondriales/inmunología , Fenotipo , Células Th2/efectos de los fármacos , Células Th2/inmunología
7.
Pharmaceutics ; 13(8)2021 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-34452206

RESUMEN

Gene therapy represents a powerful therapeutic tool to treat diseased tissues and provide a durable and effective correction. The central nervous system (CNS) is the target of many gene therapy protocols, but its high complexity makes it one of the most difficult organs to reach, in part due to the blood-brain barrier that protects it from external threats. Focused ultrasound (FUS) coupled with microbubbles appears as a technological breakthrough to deliver therapeutic agents into the CNS. While most studies focus on a specific targeted area of the brain, the present work proposes to permeabilize the entire brain for gene therapy in several pathologies. Our results show that, after i.v. administration and FUS sonication in a raster scan manner, a self-complementary AAV9-CMV-GFP vector strongly and safely infected the whole brain of mice. An increase in vector DNA (19.8 times), GFP mRNA (16.4 times), and GFP protein levels (17.4 times) was measured in whole brain extracts of FUS-treated GFP injected mice compared to non-FUS GFP injected mice. In addition to this increase in GFP levels, on average, a 7.3-fold increase of infected cells in the cortex, hippocampus, and striatum was observed. No side effects were detected in the brain of treated mice. The combining of FUS and AAV-based gene delivery represents a significant improvement in the treatment of neurological genetic diseases.

8.
Proc Natl Acad Sci U S A ; 118(10)2021 03 09.
Artículo en Inglés | MEDLINE | ID: mdl-33649222

RESUMEN

Natural killer (NK) cells are innate effectors armed with cytotoxic and cytokine-secreting capacities whose spontaneous antitumor activity is key to numerous immunotherapeutic strategies. However, current mouse models fail to mirror the extensive immune system variation that exists in the human population which may impact on NK cell-based therapies. We performed a comprehensive profiling of NK cells in the Collaborative Cross (CC), a collection of novel recombinant inbred mouse strains whose genetic diversity matches that of humans, thereby providing a unique and highly diverse small animal model for the study of immune variation. We demonstrate that NK cells from CC strains displayed a breadth of phenotypic and functional variation reminiscent of that reported for humans with regards to cell numbers, key marker expression, and functional capacities. We took advantage of the vast genetic diversity of the CC and identified nine genomic loci through quantitative trait locus mapping driving these phenotypic variations. SNP haplotype patterns and variant effect analyses identified candidate genes associated with lung NK cell numbers, frequencies of CD94+ NK cells, and expression levels of NKp46. Thus, we demonstrate that the CC represents an outstanding resource to study NK cell diversity and its regulation by host genetics.


Asunto(s)
Antígenos Ly , Regulación de la Expresión Génica/inmunología , Células Asesinas Naturales/inmunología , Subfamília D de Receptores Similares a Lectina de las Células NK , Receptor 1 Gatillante de la Citotoxidad Natural , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo/inmunología , Animales , Antígenos Ly/genética , Antígenos Ly/inmunología , Cruzamientos Genéticos , Ratones , Ratones Endogámicos , Subfamília D de Receptores Similares a Lectina de las Células NK/genética , Subfamília D de Receptores Similares a Lectina de las Células NK/inmunología , Receptor 1 Gatillante de la Citotoxidad Natural/genética , Receptor 1 Gatillante de la Citotoxidad Natural/inmunología
9.
Blood Adv ; 5(1): 26-38, 2021 01 12.
Artículo en Inglés | MEDLINE | ID: mdl-33570622

RESUMEN

Distinct metabolic demands accompany lymphocyte differentiation into short-lived effector and long-lived memory cells. How bioenergetics processes are structured in innate natural killer (NK) cells remains unclear. We demonstrate that circulating human CD56Dim (NKDim) cells have fused mitochondria and enhanced metabolism compared with CD56Br (NKBr) cells. Upon activation, these 2 subsets showed a dichotomous response, with further mitochondrial potentiation in NKBr cells vs paradoxical mitochondrial fission and depolarization in NKDim cells. The latter effect impaired interferon-γ production, but rescue was possible by inhibiting mitochondrial fragmentation, implicating mitochondrial polarization as a central regulator of NK cell function. NKDim cells are heterogeneous, and mitochondrial polarization was associated with enhanced survival and function in mature NKDim cells, including memory-like human cytomegalovirus-dependent CD57+NKG2C+ subsets. In contrast, patients with genetic defects in mitochondrial fusion had a deficiency in adaptive NK cells, which had poor survival in culture. These results support mitochondrial polarization as a central regulator of mature NK cell fitness.


Asunto(s)
Infecciones por Citomegalovirus , Citomegalovirus , Humanos , Células Asesinas Naturales , Activación de Linfocitos , Mitocondrias
10.
Epilepsia ; 61(5): 868-878, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32239694

RESUMEN

OBJECTIVE: Early onset epileptic encephalopathy with suppression-burst is one of the most severe epilepsy phenotypes in human patients. A significant proportion of cases have a genetic origin, and the most frequently mutated gene is KCNQ2, encoding Kv7.2, a voltage-dependent potassium channel subunit, leading to so-called KCNQ2-related epileptic encephalopathy (KCNQ2-REE). To study the pathophysiology of KCNQ2-REE in detail and to provide a relevant preclinical model, we generated and described a knock-in mouse model carrying the recurrent p.(Thr274Met) variant. METHODS: We introduced the p.(Thr274Met) variant by homologous recombination in embryonic stem cells, injected into C57Bl/6N blastocysts and implanted in pseudopregnant mice. Mice were then bred with 129Sv Cre-deleter to generate heterozygous mice carrying the p.(Thr274Met), and animals were maintained on the 129Sv genetic background. We studied the development of this new model and performed in vivo electroencephalographic (EEG) recordings, neuroanatomical studies at different time points, and multiple behavioral tests. RESULTS: The Kcnq2Thr274Met/+ mice are viable and display generalized spontaneous seizures first observed between postnatal day 20 (P20) and P30. In vivo EEG recordings show that the paroxysmal events observed macroscopically are epileptic seizures. The brain of the Kcnq2Thr274Met/+ animals does not display major structural defects, similar to humans, and their body weight is normal. Kcnq2Thr274Met/+ mice have a reduced life span, with a peak of unexpected death occurring for 25% of the animals by 3 months of age. Epileptic seizures were generally not observed when animals grew older. Behavioral characterization reveals important deficits in spatial learning and memory in adults but no gross abnormality during early neurosensory development. SIGNIFICANCE: Taken together, our results indicate that we have generated a relevant model to study the pathophysiology of KCNQ2-related epileptic encephalopathy and perform preclinical research for that devastating and currently intractable disease.


Asunto(s)
Disfunción Cognitiva/etiología , Epilepsia Generalizada/etiología , Canal de Potasio KCNQ2/metabolismo , Convulsiones/etiología , Animales , Encéfalo/patología , Disfunción Cognitiva/genética , Modelos Animales de Enfermedad , Electroencefalografía , Epilepsia Generalizada/genética , Femenino , Técnicas de Sustitución del Gen , Canal de Potasio KCNQ2/genética , Canal de Potasio KCNQ2/fisiología , Masculino , Aprendizaje por Laberinto , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Convulsiones/genética
11.
J Biomed Mater Res B Appl Biomater ; 106(3): 1156-1164, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-28556590

RESUMEN

Despite the worldwide high prevalence of total joint arthroplasty (TJA), life expectancy of prosthesis remains limited by mechanical and chemical constraint which promote wear debris production, surrounding tissues damage and finally prosthesis loosening. Such results could be amplified by neuro-myoelectrostimulation (NMES; widely used to reduce neuromuscular deficits observed following TJA surgery). It was previously described in an in vivo experiment that interactions between NMES and Ti6Al4V implant are deleterious for both implant and surrounding muscles. The purpose of the present study was to compare the biocompatibility of four common orthopedic biomaterials, two metallic (Ti6Al4V, CrCo) and two nonmetallic (PEEK, Al2 O3 ) alloys, fixed on rat tibial crest in which the surrounding muscles were electrostimulated. Muscle cell death rate was not found significantly increased, with or without electrical stimulation for nonmetallic implants. Contrary to Ti6Al4V alloy, the CrCo implant did not induce destruction of the surrounding muscle. However, cell viability decreased for both metallic alloys when NMES was applied but within a greater significant extent for Ti6Al4V implant. Otherwise, when NMES was applied, implant-to-bone adhesion significantly decreased for Ti6Al4V while no significant difference was found for PEEK, Al2 O3 , and CrCo. Statistical analyses reveal also a lesser adhesion strength for Ti6Al4V compared with CrCo when NMES was applied. Selecting the most suitable material in term of biocompatibility remains a major concern and non-metallic materials seems to be more appropriated in regard to electrical currents used for post TJA care. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1156-1164, 2018.


Asunto(s)
Materiales Biocompatibles , Estimulación Eléctrica , Ensayo de Materiales , Adhesividad , Aleaciones , Óxido de Aluminio/química , Animales , Artroplastia de Reemplazo , Benzofenonas , Huesos/patología , Supervivencia Celular , Cetonas/química , Masculino , Fibras Musculares Esqueléticas/patología , Músculo Esquelético/fisiología , Polietilenglicoles/química , Polímeros , Diseño de Prótesis , Ratas , Ratas Sprague-Dawley , Titanio/química
12.
Int J Mol Sci ; 18(7)2017 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-28696371

RESUMEN

Nowadays, salt consumption appears to be drastically above the recommended level in industrialized countries. The health consequences of this overconsumption are heavy since high-salt intake induces cardiovascular disease, kidney dysfunction, and stroke. Moreover, harmful interaction may also occur with orthopaedic devices because overconsumption of salt reinforces the corrosive aspect of biological tissues and favors bone resorption process. In the present study, we aimed to assess the in vivo effect of three weeks of a high-salt diet, associated (or not) with two weeks of the neuro-myoelectrostimulation (NMES) rehabilitation program on the biocompatibility of four biomaterials used in the manufacture of arthroplasty implants. Thus, two non-metallic (PEEK and Al2O3) and two metallic (Ti6Al4V and CrCo) compounds were implanted in the rat tibial crest, and the implant-to-bone adhesion and cell viability of two surrounded muscles, the Flexor Digitorum (FD) and Tibialis Anterior (TA), were assessed at the end of the experiment. Results indicated lower adhesion strength for the PEEK implant compared to other biomaterials. An effect of NMES and a high-salt diet was only identified for Al2O3 and Ti6Al4V implants, respectively. Moreover, compared to a normal diet, a high-salt diet induced a higher number of dead cells on both muscles for all biomaterials, which was further increased for PEEK, Al2O3, and CrCo materials with NMES application. Finally, except for Ti6Al4V, NMES induced a higher number of dead cells in the directly stimulated muscle (FD) compared to the indirectly stimulated one (TA). This in vivo experiment highlights the potential harmful effect of a high-salt diet for people who have undergone arthroplasty, and a rehabilitation program based on NMES.


Asunto(s)
Materiales Biocompatibles/química , Cloruro de Sodio Dietético/efectos adversos , Aleaciones , Óxido de Aluminio/química , Animales , Benzofenonas , Supervivencia Celular/efectos de los fármacos , Humanos , Cetonas/química , Masculino , Polietilenglicoles/química , Polímeros , Ratas , Ratas Sprague-Dawley , Titanio/química
13.
J Immunol ; 196(11): 4731-8, 2016 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-27183613

RESUMEN

Group 3 innate lymphoid cells (ILC3) actively participate in mucosal defense and homeostasis through prompt secretion of IL-17A, IL-22, and IFN-γ. Reports identify two ILC3 lineages: a CCR6(+)T-bet(-) subset that appears early in embryonic development and promotes lymphoid organogenesis and a CCR6(-)T-bet(+) subset that emerges after microbial colonization and harbors NKp46(+) ILC3. We demonstrate that NKp46 expression in the ILC3 subset is highly unstable. Cell fate mapping using Ncr1(CreGFP) × Rosa26(RFP) mice revealed the existence of an intestinal RFP(+) ILC3 subset (Ncr1(FM)) lacking NKp46 expression at the transcript and protein levels. Ncr1(FM) ILC3 produced more IL-22 and were distinguishable from NKp46(+) ILC3 by differential CD117, CD49a, DNAX accessory molecule-1, and, surprisingly, CCR6 expression. Ncr1(FM) ILC3 emerged after birth and persisted in adult mice following broad-spectrum antibiotic treatment. These results identify an unexpected phenotypic instability within NKp46(+) ILC3 that suggests a major role for environmental signals in tuning ILC3 functional plasticity.


Asunto(s)
Antígenos Ly/inmunología , Inmunidad Innata/inmunología , Intestinos/inmunología , Linfocitos/inmunología , Receptor 1 Gatillante de la Citotoxidad Natural/inmunología , Animales , Células Cultivadas , Intestinos/citología , Linfocitos/citología , Ratones , Ratones Transgénicos , Fenotipo
14.
PLoS One ; 11(1): e0146873, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26761710

RESUMEN

AIM OF THE STUDY: High-salt consumption has been widely described as a risk factor for cardiovascular, renal and bone functions. In the present study, the extent to which high-salt diet could influence Ti6Al4V implant surface characteristic, its adhesion to rat tibial crest, and could modify muscle cell viability of two surrounding muscles, was investigated in vivo. These parameters have also been assessed following a NMES (neuro-myoelectrostimulation) program similar to that currently used in human care following arthroplasty. RESULTS: After a three-week diet, a harmful effect on titanium implant surface and muscle cell viability was noted. This is probably due to salt corrosive effect on metal and then release of toxic substance around biologic tissue. Moreover, if the use of NMES with high-salt diet induced muscles damages, the latter were higher when implant was added. Unexpectedly, higher implant-to-bone adhesion was found for implanted animals receiving salt supplementation. CONCLUSION: Our in vivo study highlights the potential dangerous effect of high-salt diet in arthroplasty based on titanium prosthesis. This effect appears to be more important when high-salt diet is combined with NMES.


Asunto(s)
Músculos/fisiología , Prótesis e Implantes , Cloruro de Sodio Dietético/efectos adversos , Titanio/química , Aleaciones , Animales , Artroplastia , Presión Sanguínea , Supervivencia Celular , Materiales Biocompatibles Revestidos , Dieta , Estimulación Eléctrica , Masculino , Músculos/patología , Oseointegración/fisiología , Implantación de Prótesis , Ratas , Ratas Sprague-Dawley , Factores de Riesgo , Propiedades de Superficie , Tibia/patología
15.
J Biomed Mater Res B Appl Biomater ; 103(8): 1594-601, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25533414

RESUMEN

Electrical currents have deleterious effects on biomedical metallic implants. However, following arthroplasty, neuro-myoelectrostimulation (NMES) is often used in patient rehabilitation. Such a rehabilitation technique could compromise patient recovery through deleterious effects on metallic alloys and biological tissues. The purpose of our study was to assess the effects of NMES on a Ti6Al4V implant placed in a rat tibial crest and the surrounding muscle tissues. This in vivo study allowed to bring to the fore the prosthesis behavior under mechanical and electromagnetic loads induced by NEMS stimulation. After 3 weeks, implant-to-bone adhesion significantly decreased in stimulated animals compared with nonstimulated animals. Surface mapping indicated titanium implant degradation after NMES. Furthermore, NMES alone did not induce muscle damage contrary to that found in implanted animals. The muscle damage rate was significantly higher in implanted and stimulated animals compared with implanted-only animals. It seems obvious that rehabilitation programs using the NMES technique could induce early deterioration of biomaterial employed for surgical implants. Clinicians should reconsider the use of NMES as a rehabilitation technique for patients with titanium prostheses.


Asunto(s)
Sustitutos de Huesos , Ensayo de Materiales , Células Musculares/metabolismo , Músculo Esquelético/metabolismo , Prótesis e Implantes , Tibia/metabolismo , Titanio , Aleaciones , Animales , Células Musculares/patología , Músculo Esquelético/patología , Ratas , Tibia/patología
16.
Eur J Immunol ; 44(11): 3380-91, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25142413

RESUMEN

To study gene functions specifically in NKp46+ cells we developed novel Cre mice allowing for conditional gene targeting in cells expressing Ncr1 (encoding NKp46). We generated transgenic Ncr1(greenCre) mice carrying an EGFPcre fusion under the control of a proximal Ncr1 promoter that faithfully directed EGFPcre expression to NKp46+ cells from lymphoid and nonlymphoid tissues. This approach allowed for direct detection of Cre-expressing NKp46+ cells via their GFP signature by flow cytometry and histology. Cre was functional as evidenced by the NKp46+ cell-specific expression of RFP in Ncr1(greenCre) Rosa-dtRFP reporter mice. We generated Ncr1(greenCre) Il2rg(fl/fl) mice that lack NKp46+ cells in an otherwise intact hematopoietic environment. Il2rg encodes the common gamma chain (γc ), which is an essential receptor subunit for cytokines (IL-2, -4, -7, -9, -15, and -21) that stimulate lymphocyte development and function. In Ncr1(greenCre) Il2rg(fl/fl) mice, NK cells are severely reduced and the few remaining NKp46+ cells escaping γc deletion failed to express GFP. Using this new NK-cell-deficient model, we demonstrate that the homeostasis of NKp46+ cells from all tissues (including the recently described intraepithelial ILC1 subset) requires Il2rg. Finally, Ncr1(greenCre) Il2rg(fl/fl) mice are unable to reject B16 lung metastases demonstrating the essential role of NKp46+ cells in antimelanoma immune responses.


Asunto(s)
Antígenos Ly/genética , Células Asesinas Naturales/inmunología , Neoplasias Pulmonares/secundario , Melanoma Experimental/patología , Receptor 1 Gatillante de la Citotoxidad Natural/genética , Animales , Antígenos Ly/biosíntesis , Linfocitos B/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Proteínas Fluorescentes Verdes/genética , Subunidad gamma Común de Receptores de Interleucina/genética , Neoplasias Pulmonares/inmunología , Melanoma Experimental/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptor 1 Gatillante de la Citotoxidad Natural/biosíntesis
17.
Biomaterials ; 35(24): 6248-58, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24814425

RESUMEN

The present study is designed to assess the properties of a new degradable PLA-b-PHEMA block copolymer hydrogel and its therapeutic effectiveness after implantation following a thoracic spinal cord hemisection on rats. Degradable characteristics and porous aspect of the scaffold are respectively analyzed by the evaluation of its mass loss and by electron microscopy. The biomaterial toxicity is measured through in vitro tests based on motoneuron survival and neurite growth on copolymer substrate. Functional measurements are assessed by the Basso, Beattie and Bresnahan (BBB) and the Dynamic Weight Bearing (DWB) tests during 8 weeks post-surgery. Histological analyses are achieved to evaluate the presence of blood vessels and axons, the density of the glial scar, the inflammatory reaction and the myelination at the lesion site and around it. The results indicate that the synthetic PLA-b-PHEMA block copolymer is a non-toxic and degradable biomaterial that provides support for regenerating axons and seems to limit scar tissue formation. Additionally, the implantation of the porous PLA-b-PHEMA scaffold enhances locomotor improvement. The observed functional recovery highlights the potential benefits of plain tissue engineering material, which can further be optimized by bioactive molecule functionalization or transplanted cell encapsulation.


Asunto(s)
Ácido Láctico/farmacología , Polihidroxietil Metacrilato/farmacología , Polímeros/farmacología , Implantación de Prótesis , Traumatismos de la Médula Espinal/patología , Cicatrización de Heridas/efectos de los fármacos , Animales , Ácido Láctico/química , Ácido Láctico/toxicidad , Masculino , Actividad Motora/efectos de los fármacos , Neuritas/efectos de los fármacos , Neuritas/metabolismo , Poliésteres , Polihidroxietil Metacrilato/química , Polihidroxietil Metacrilato/toxicidad , Polímeros/química , Polímeros/toxicidad , Porosidad , Presión , Ratas Sprague-Dawley , Recuperación de la Función/efectos de los fármacos , Traumatismos de la Médula Espinal/fisiopatología , Traumatismos de la Médula Espinal/cirugía , Andamios del Tejido/química , Soporte de Peso
18.
PLoS One ; 9(2): e89953, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24587147

RESUMEN

The purpose of the study was to highlight the acute motor reflex adaptation and to deepen functional deficits following a middle cerebral artery occlusion-reperfusion (MCAO-r). Thirty-six Sprague-Dawley rats were included in this study. The middle cerebral artery occlusion (MCAO; 120 min) was performed on 16 rats studied at 1 and 7 days, respectively (MCAO-D1 and MCAO-D7, n = 8 for each group). The other animals were divided into 3 groups: SHAM-D1 (n = 6), SHAM-D7 (n = 6) and Control (n = 8). Rats performed 4 behavioral tests (the elevated body swing test, the beam balance test, the ladder-climbing test and the forelimb grip force) before the surgery and daily after MCAO-r. H-reflex on triceps brachii was measured before and after isometric exercise. Infarction size and cerebral edema were respectively assessed by histological (Cresyl violet) and MRI measurements at the same time points than H-reflex recordings. Animals with cerebral ischemia showed persistent functional deficits during the first week post-MCAO-r. H-reflex was not decreased in response to isometric exercise one day after the cerebral ischemia contrary to the other groups. The motor reflex regulation was recovered 7 days post-MCAO-r. This result reflects an acute sensorimotor adaptation at the spinal level after MCAO-r.


Asunto(s)
Infarto de la Arteria Cerebral Media/fisiopatología , Animales , Reflejo H/fisiología , Masculino , Actividad Motora/fisiología , Ratas , Ratas Sprague-Dawley , Reperfusión
19.
Behav Brain Res ; 259: 78-84, 2014 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-24200548

RESUMEN

The aim of the present study is to assess the relevance of weight-bearing distribution (DWB) measurement in freely moving rats after stroke and thoracic spinal cord injuries. Animals were divided in 2 experiments: (1) The middle cerebral artery occlusion-reperfusion (MCAO-r) experiment containing the MCAO group in which focal brain ischaemia was induced by transient MCA occlusion and (2) the thoracic hemisection experiment containing the TH group in which a spinal cord hemisection was performed at the T10 level. A Control and respective Sham groups were also included in each experiment. Not only the pressure exerted by each paw was measured but also different ratios such as: (1) the sum of the right and the left forepaws was normalized by the sum of the right and the left hindpaws (F/H), (2) the left forepaw was normalized by the right forepaw (LF/RF), (3) the left hindpaw was normalized by the right hindpaw (LH/RH). Additionally, the times spent on 3 paws and on 4 paws were measured. Only the time spent on 4 paws was shorter in the MCAO group than in the Control (p<0.001) and in the Sham (p<0.01) groups. The LH/RH ratio of the TH group at the 1st week was lower (p<0.01) than the pre-surgical value. Moreover, its F/H ratio was superior (p<0.001) to the ones of the Control and the Sham groups. Our study indicates that DWB should be more frequently used to evaluate both the severity of central nervous system traumas and the effectiveness of pharmacological and/or rehabilitation strategies.


Asunto(s)
Infarto de la Arteria Cerebral Media/fisiopatología , Daño por Reperfusión/fisiopatología , Traumatismos de la Médula Espinal/fisiopatología , Soporte de Peso/fisiología , Animales , Modelos Animales de Enfermedad , Lateralidad Funcional , Masculino , Actividad Motora/fisiología , Examen Neurológico , Ratas , Ratas Sprague-Dawley , Índice de Severidad de la Enfermedad , Factores de Tiempo
20.
Biochim Biophys Acta ; 1832(12): 2340-51, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24080196

RESUMEN

Cystic fibrosis (CF) airway epithelium is constantly subjected to injury events due to chronic infection and inflammation. Moreover, abnormalities in CF airway epithelium repair have been described and contribute to the lung function decline seen in CF patients. In the last past years, it has been proposed that anoctamin 1 (ANO1), a Ca(2+)-activated Cl(-) channel, might offset the CFTR deficiency but this protein has not been characterized in CF airways. Interestingly, recent evidence indicates a role for ANO1 in cell proliferation and tumor growth. Our aims were to study non-CF and CF bronchial epithelial repair and to determine whether ANO1 is involved in airway epithelial repair. Here, we showed, with human bronchial epithelial cell lines and primary cells, that both cell proliferation and migration during epithelial repair are delayed in CF compared to non-CF cells. We then demonstrated that ANO1 Cl(-) channel activity was significantly decreased in CF versus non-CF cells. To explain this decreased Cl(-) channel activity in CF context, we compared ANO1 expression in non-CF vs. CF bronchial epithelial cell lines and primary cells, in lung explants from wild-type vs. F508del mice and non-CF vs. CF patients. In all these models, ANO1 expression was markedly lower in CF compared to non-CF. Finally, we established that ANO1 inhibition or overexpression was associated respectively with decreases and increases in cell proliferation and migration. In summary, our study demonstrates involvement of ANO1 decreased activity and expression in abnormal CF airway epithelial repair and suggests that ANO1 correction may improve this process.


Asunto(s)
Bronquios/patología , Canales de Cloruro/metabolismo , Regulador de Conductancia de Transmembrana de Fibrosis Quística/fisiología , Fibrosis Quística/patología , Células Epiteliales/patología , Pulmón/patología , Proteínas de Neoplasias/metabolismo , Mucosa Respiratoria/patología , Adulto , Animales , Anoctamina-1 , Western Blotting , Bronquios/metabolismo , Estudios de Casos y Controles , Membrana Celular/metabolismo , Movimiento Celular , Proliferación Celular , Canales de Cloruro/genética , Cloruros/metabolismo , Fibrosis Quística/genética , Fibrosis Quística/metabolismo , Células Epiteliales/metabolismo , Humanos , Técnicas para Inmunoenzimas , Canales Iónicos/metabolismo , Pulmón/metabolismo , Ratones , Ratones Endogámicos CFTR , Persona de Mediana Edad , Proteínas de Neoplasias/genética , ARN Mensajero/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Mucosa Respiratoria/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
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