ABSTRACT
Resumen Los schwannomas son neoplasias derivadas de las células de Schwann de la cubierta de los nervios periféricos. Su desarrollo en la región nasosinusal es poco frecuente, especialmente a nivel septal. Su diagnóstico diferencial es variado y debe establecerse con otras causas más habituales de masa nasal unilateral. Su tratamiento es quirúrgico. Describimos el caso de un varón de 47 años con una masa nasal derecha intervenida mediante cirugía endoscópica nasosinusal y con diagnóstico anatomopatológico de schwannoma septal.
Abstract Schwannomas are tumors that proceed from Schwann cells in the cover of peripheral nerves. It is uncommon in the sinonasal area, especially in the nasal septum. The differential diagnosis is extensive and requires contemplating other more frequent causes of unilateral nasal mass. The current treatment of septal schwannoma is surgical. We report a 47-year-old male with a right nasal mass operated by endoscopic sinonasal surgery with an anatomopathological diagnosis of a nasal septal schwannoma.
Subject(s)
Humans , Male , Middle Aged , Nose Neoplasms/pathology , Nasal Septum/pathology , Neurilemmoma/pathology , Schwann Cells/pathology , Nose Neoplasms/surgery , Nose Neoplasms/diagnostic imaging , Diagnosis, Differential , Nasal Septum/surgery , Nasal Septum/diagnostic imaging , Neurilemmoma/surgery , Neurilemmoma/diagnostic imagingABSTRACT
Los Schwannomas son tumores derivados de las células de Schwann de las vainas de los nervios periféricos. Se pueden localizar en cualquier región anatómica que contenga tejido nervioso periférico, siendo más frecuentes en la región craneofacial y las extremidades. Los Schwannomas pancreáticos son entidades sumamente infrecuentes de las cuales solo se han descrito 68 casos a nivel mundial. En el presente trabajo se presenta el caso de un paciente con hallazgo incidental de tres tumores sincrónicos dentro de los cuales se encuentra un Schwannoma pancreático.Caso clínico : Paciente femenino de 66 años de edad con antecedente de diabetes mellitus tipo 1 y enfermedad diverticular pancolónica quien acude presentando cuadro clínico compatible con absceso lumbar izquierdo. Se realiza TC de abdomen y pelvis con doble contraste que evidencia extensa área de colección heterogénea en región retroperitoneal que diseca hacia región lumbar y glútea izquierda, además de la presencia de tumor hipodenso de bordes lobulados en mesogastrio. Se realiza colonoscopia que reporta lesión exofítica ulcerada en unión rectosigmoidea. El resto de paraclínicos y estudios de extensión se encontraban dentro de límites normales. Se decide resolución quirúrgica mediante drenaje percutáneo de absceso y laparotomía exploradora. Informe histopatológico: cistoadenoma seroso microquístico de cuerpo de páncreas, Schwannoma de cola de páncreas y adenocarcinoma moderadamente diferenciado de colon sigmoides.Conclusión : Los Schwannomas pancreáticos son entidades sumamente infrecuentes que pueden presentarse con una amplia variedad de manifestaciones clínicas, sin embargo, deben tenerse en cuenta como posible diagnóstico diferencial ante el hallazgo de un tumor pancreático(AU)
Schwannomas, also called Neurilemmomas or Neurinomas, are tumors derived from Schwann cells of the peripheral nerve sheaths. They can be located in any anatomical region that contains peripheral nervous tissue, being more frequent in the craniofacial region and the extremities. Pancreatic Schwannomas are extremely rare entities of which only 68 cases have been described worldwide. In the present study we present the case of a patient with an incidental finding of three synchronous tumors, including a pancreatic Schwannoma.Clinical case : A 66-year-old female patient with a history of type 1 diabetes mellitus and pancolonic diverticular disease who presented with symptoms compatible with left lumbar abscess. A double-contrast CT of the abdomen and pelvis was performed, which revealed a large area of heterogeneous collection in the retroperitoneal region that dissected towards the left lumbar and gluteal region, in addition to the presence of a hypodense tumor with lobulated borders in the mesogastrium. A colonoscopy was performed, which reported an ulcerated exophytic lesion at the rectosigmoid junction. The rest of the paraclinical and extension studies were within normal limits. Surgical resolution is decided by percutaneous abscess drainage and exploratory laparotomy. Histopathological report: microcystic serous cystadenoma of the body of the pancreas, Schwannoma of the pancreas tail, and moderately differentiated adenocarcinoma of the sigmoid colon.Conclusion : Pancreatic Schwannomas are extremely rare entities that can present with a wide variety of clinical manifestations, however, they should be taken into account as a possible differential diagnosis when a pancreatic tumor is found(AU)
Subject(s)
Humans , Female , Aged , Schwann Cells/pathology , Neurofibrosarcoma , Carcinoma, Pancreatic Ductal , Diverticular Diseases , Colonoscopy , Colon , Cystadenoma, Serous , Nerve TissueABSTRACT
Enhancing remyelination after injury is of utmost importance for optimizing the recovery of nerve function. While the formation of myelin by Schwann cells (SCs) is critical for the function of the peripheral nervous system, the temporal dynamics and regulatory mechanisms that control the progress of the SC lineage through myelination require further elucidation. Here, using in vitro co-culture models, gene expression profiling of laser capture-microdissected SCs at various stages of myelination, and multilevel bioinformatic analysis, we demonstrated that SCs exhibit three distinct transcriptional characteristics during myelination: the immature, promyelinating, and myelinating states. We showed that suppressor interacting 3a (Sin3A) and 16 other transcription factors and chromatin regulators play important roles in the progress of myelination. Sin3A knockdown in the sciatic nerve or specifically in SCs reduced or delayed the myelination of regenerating axons in a rat crushed sciatic nerve model, while overexpression of Sin3A greatly promoted the remyelination of axons. Further, in vitro experiments revealed that Sin3A silencing inhibited SC migration and differentiation at the promyelination stage and promoted SC proliferation at the immature stage. In addition, SC differentiation and maturation may be regulated by the Sin3A/histone deacetylase2 (HDAC2) complex functionally cooperating with Sox10, as demonstrated by rescue assays. Together, these results complement the recent genome and proteome analyses of SCs during peripheral nerve myelin formation. The results also reveal a key role of Sin3A-dependent chromatin organization in promoting myelinogenic programs and SC differentiation to control peripheral myelination and repair. These findings may inform new treatments for enhancing remyelination and nerve regeneration.
Subject(s)
Animals , Axons , Chromatin/metabolism , Gene Expression Profiling , Myelin Sheath/metabolism , Nerve Regeneration/physiology , Rats , Schwann Cells/metabolism , Sciatic Nerve/injuriesABSTRACT
Los schwannomas son neoplasias predominantemente benignas y de crecimiento lento, encapsulado y generalmente solitario, que se originan a partir de las células de Schwann de la vaina del nervio periférico. En la cavidad oral su prevalencia es muy baja, siendo la localización más frecuente la lengua. El diagnóstico se basa en el estudio histopatológico. El tratamiento de elección es la exéresis quirúrgica. Reportamos un caso raro de schwannoma lingual en un joven de 12 años de edad que acude por consulta externa por aumento de volumen en región dorsal de lengua que abarca hasta región submentoniana, de 4 años de evolución, con dificultad en la deglución y pronunciación. Después de estudios histopatológicos y de imagen se confirma el diagnostico de Schwannoma lingual, es intervenido quirúrgicamente a exéresis de lesión confirmando el diagnostico. El schwannoma lingual es una neoplasia benigna poco frecuente cuyo pronóstico es excelente y con bajas tasas de recurrencia tras su exéresis quirúrgica.
Schwannomas are predominantly benign, slow-growing encapsulated and usually solitary neoplasms that arise from Schwann cells of the peripheral nerve sheath. In the oral cavity its prevalence is very low, the most common location being the tongue. Diagnosis is based on histopathological study. The treatment of choice is surgical removal. We report a rare case of lingual schwannoma in a 12-year-old boy who came to the outpatient clinic due to an increase in volume in the dorsal region of the tongue that reached the submental region of 4 years of evolution, with difficulty in swallowing and pronunciation. After histopathological and imaging studies confirmed the diagnosis of lingual Schwannoma, he underwent surgery to remove the lesion, confirming the diagnosis. Lingual schwannoma is a rare benign neoplasm whose prognosis is excellent and with low rates of recurrence after surgical removal.
Subject(s)
Humans , Male , Child , Schwann Cells , NeoplasmsABSTRACT
Resumen El tumor de células granulares es una neoplasia infrecuente, de comportamiento biológico benigno. Por lo general, se presenta entre la cuarta y sexta década de vida como una lesión solitaria, de crecimiento lento y buen pronóstico. Su histogénesis es probablemente de origen neural siendo positivo para S-100 y Enolasa Neuronal Especifica. Se muestra un caso con una localización inusual en la región axilar, las dificultades para alcanzar el diagnóstico puesto que puede confundirse con otras neoplasias, y los elementos clínicos esenciales de este tipo de tumor.
Abstract Granular cell tumor is a rare neoplasm with benign behavior. It usually occurs in the fourth to sixth decade of life as a solitary, slow growing lesion with a good prognosis. Its histogenesis is probably of neural origin, being positive for S-100 and Neuron-Specific Enolase. We demonstrate an unusual location in the axillary region, the obstacles to reaching the diagnosis since it can be confused with other malignancies, and the essential elements for clinically suspecting benign lesions of this type.
Subject(s)
Female , Adult , Schwann Cells , Granular Cell Tumor , PrognosisABSTRACT
Mucosal Schwann cell hamartoma (MSCH) is a rare benign neurogenic tumor characterized by pure S100p positive spindle cell proliferation. Most cases occur in the distal colon. Involvement of the gall bladder is exceedingly rare. There have been no reports of recurrence or a syndromic association with MSCH. Herein, we describe a case of MSCH of the gallbladder in a 55-year-old female patient with prior history of gastrointestinal neurofibromas who presented with abdominal pain. MR imaging revealed choledocholithiasis, gallbladder thickening, and marked biliary and pancreatic ductal dilation. The patient subsequently underwent cholecystectomy with choledochoduodenostomy. Histologic evaluation of the gallbladder showed diffuse expansion of the mucosa with S100p positive cells with spindly nuclei and indistinct cytoplasmic borders and diagnosis of MSCH of the gallbladder was rendered.
Subject(s)
Humans , Female , Middle Aged , Schwann Cells/pathology , Gallbladder Neoplasms/pathology , Hamartoma/pathology , Neurofibroma/pathology , NeuromaABSTRACT
BACKGROUND@#Histological and functional recovery after peripheral nerve injury (PNI) is of significant clinical value as delayed surgical repair and longer distances to innervate terminal organs may account for poor outcomes. Low-intensity extracorporeal shock wave therapy (LiESWT) has already been proven to be beneficial for injured tissue recovery on various pathological conditions. The objective of this study was to explore the potential effect and mechanism of LiESWT on PNI recovery.@*METHODS@#In this project, we explored LiESWT's role using an animal model of sciatic nerve injury (SNI). Shockwave was delivered to the region of the SNI site with a special probe at 3 Hz, 500 shocks each time, and 3 times a week for 3 weeks. Rat Schwann cells (SCs) and rat perineurial fibroblasts (PNFs) cells, the two main compositional cell types in peripheral nerve tissue, were cultured in vitro, and LiESWT was applied through the cultured dish to the adherent cells. Tissues and cell cultures were harvested at corresponding time points for a reverse transcription-polymerase chain reaction, Western blotting, and immunofluorescence staining. Multiple groups were compared by using one-way analysis of variance followed by the Tukey-Kramer test for post hoc comparisons.@*RESULTS@#LiESWT treatment promoted the functional recovery of lower extremities with SNI. More nerve fibers and myelin sheath were found after LiESWT treatment associated with local upregulation of mechanical sensitive yes-associated protein (YAP)/transcriptional co-activator with a PDZ-binding domain (TAZ) signaling pathway. In vitro results showed that SCs were more sensitive to LiESWT than PNFs. LiESWT promoted SCs activation with more expression of p75 (a SCs dedifferentiation marker) and Ki67 (a SCs proliferation marker). The SCs activation process was dependent on the intact YAP/TAZ signaling pathway as knockdown of TAZ by TAZ small interfering RNA significantly attenuated this process.@*CONCLUSION@#The LiESWT mechanical signal perception and YAP/TAZ upregulation in SCs might be one of the underlying mechanisms for SCs activation and injured nerve axon regeneration.
Subject(s)
Animals , Axons , Extracorporeal Shockwave Therapy , Nerve Regeneration , Peripheral Nerve Injuries/therapy , Rats , Schwann Cells , Sciatic Nerve , Signal TransductionABSTRACT
OBJECTIVES@#This study investigated the effects of different implant surface properties on the biological behavior of Schwann cells.@*METHODS@#Schwann cells (SCs) were cultured on three types of implant surfaces including smooth polished (SMO), sand-blasted, large grit, acid-etched (SLA), and chemically-modified SLA (modSLA). At different time points, the morphology and adhesion of SCs on the implant surfaces were observed by scanning electron microscope. Cell proliferation activity was detected by MTT method. The expression levels of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) were detected by enzyme-linked immunosorbent assay. Changes in the mRNA levels of NGF and BDNF were detected by real-time fluorescent quantitative polymerase chain reaction (PCR).@*RESULTS@#SCs adhered, stretched, and proliferated well on the three types of implant surfaces. On the 3rd, 5th, and 7th days, the OD values of the SMO group were higher than those of the SLA group and the modSLA group, and the difference was statistically significant (@*CONCLUSIONS@#Different implant surface properties have different effects on the biological behavior of SCs. Proliferation of SCs is significantly promoted by smooth surface, while secretion and gene expression of neurotrophic factors are significantly promoted by modSLA surface at early stage.
Subject(s)
Dental Implants , Schwann Cells , Surface Properties , TitaniumABSTRACT
PURPOSE@#Wallerian degeneration (WD) is an antegrade degenerative process distal to peripheral nerve injury. Numerous genes are differentially regulated in response to the process. However, the underlying mechanism is unclear, especially the early response. We aimed at investigating the effects of sciatic nerve injury on WD via CLDN 14/15 interactions in vivo and in vitro.@*METHODS@#Using the methods of molecular biology and bioinformatics analysis, we investigated the molecular mechanism by which claudin 14/15 participate in WD. Our previous study showed that claudins 14 and 15 trigger the early signal flow and pathway in damaged sciatic nerves. Here, we report the effects of the interaction between claudin 14 and claudin 15 on nerve degeneration and regeneration during early WD.@*RESULTS@#It was found that claudin 14/15 were upregulated in the sciatic nerve in WD. Claudin 14/15 promoted Schwann cell proliferation, migration and anti-apoptosis in vitro. PKCα, NT3, NF2, and bFGF were significantly upregulated in transfected Schwann cells. Moreover, the expression levels of the β-catenin, p-AKT/AKT, p-c-jun/c-jun, and p-ERK/ERK signaling pathways were also significantly altered.@*CONCLUSION@#Claudin 14/15 affect Schwann cell proliferation, migration, and anti-apoptosis via the β-catenin, p-AKT/AKT, p-c-jun/c-jun, and p-ERK/ERK pathways in vitro and in vivo. The results of this study may help elucidate the molecular mechanisms of the tight junction signaling pathway underlying peripheral nerve degeneration.
Subject(s)
Animals , Claudins , Nerve Regeneration , Peripheral Nerve Injuries , Rats , Schwann Cells/pathology , Sciatic Nerve , Wallerian Degeneration/pathologyABSTRACT
Introducción: El schwannoma (neurinoma o neurilemoma) es un tumor benigno originado en la vaina de mielina de los nervios periféricos a partir de la células de Schwann. En su variedad benigna es el tumor más frecuente dependiente de esta estructuras. Se manifiesta entre la tercera y quinta década de vida, sin distinción de género. La localización axilar es extremadamente infrecuente, constituyendo el 5% de todos los casos reportados. Los schwannomas son tumores bien delimitados y de lento crecimiento. La presentación más frecuente es como masa palpable o por la sintomatología clínica correspondiente al territorio de inervación del nervio afectado. Es importante tener en cuenta que estas lesiones puedes formar parte de cuadros clínicos de base genética más complejos como la neurofibromatosis, entre otros. El método diagnóstico de elección es la resonancia magnética nuclear. El tratamiento consiste en la extirpación de la lesión tratando de preservar la función de la estructura nerviosa afectada. Objetivo: El objetivo del presente trabajo es realizar el reporte de un caso de lesión compatible con schwannoma axilar y realizar un revisión de la literatura.
Introduction: Schwannoma (neurinoma or neurilemoma) is a benign tumor originated in myelin sheath of peripheral nerves from schwann cells. In its benign variety, it is the most frequent tumor dependent of these structures. It appears between the third and fifth decade of life without distinction of geder. Axillary location is extremely rare, accounting for 5% of all reported cases. Schwqnnomas are well-defide, slow-growing tumors. The most frequent presentation is as palpabel mass or due to the clinical symptoms corresponding to the innervation territory of the affected nerve. It's important to know that these lesions can be part of more complex genetic-based clinical cases such as neurofibromatosis. The diagnostic method of choice is magnetic resonance imaging. Treatment cosists of excising the lesion, trying to preserve the function of the affected nerve structure. Objetive: The aim of this report is to describe our experience with one case of axillary schwannoma diagnosed in our institution and to perform a review of the literature.
Subject(s)
Schwann Cells , Peripheral Nerves , Therapeutics , Magnetic Resonance Imaging , Neurofibromatoses , Neoplasms , NeurilemmomaABSTRACT
El schwannoma es un tumor primario, habitualmente, benigno, procedente de las células de Schwann, productoras de la vaina de mielina que recubre los nervios periféricos. Constituye menos del 10 % de los tumores intracraneales y es infrecuente en la edad pediátrica.Se presenta a un paciente de 6 años y 11 meses de edad, previamente sano, con antecedente de cefalea holocraneana intermitente asociado a proptosis y disminución de la agudeza visual del ojo izquierdo, epífora y estrabismo, con evidencia tomográfica de una masa retroocular. Se realizó la exéresis macroscópicamente completa, con diagnóstico anatomopatológico de schwannoma orbitario
Schwannoma is a usually benign primary tumor. It develops from the Schwann cells, which produce the myelin sheath that surrounds the peripheral nerves. It represents less than 10 % of the intracranial tumors, and it is infrequent in the pediatric age.We hereby present a 6-year-and-11-month-old previously healthy patient, with a history of intermittent generalized cephalea associated with proptosis and a diminished visual acuity of the left eye, epiphora and strabismus, with radiological evidence of retro-ocular mass. A macroscopically complete exeresis was performed, with an anatomopathological diagnosis of orbital schwannoma
Subject(s)
Humans , Male , Child , Schwann Cells , Neurilemmoma/diagnostic imaging , Orbit/injuries , Exophthalmos , Neoplasms , Neurilemmoma/surgeryABSTRACT
A hanseníase é uma doença infecciosa, desmielinizante, que pode levar à incapacidades e deformidades físicas permanentes. Dados anteriores demonstraram que Mycobacterium leprae, o agente etiológico da doença, consegue modular a biologia das células de Schwann. Um ponto ainda não elucidado é se o dano neural na hanseníase é causado diretamente pelo bacilo ou se é dependente do infiltrado inflamatório. Sabe-se que durante os episódios reacionais, o aumento de citocinas pró-inflamatórias, como IFN-γ, pode contribuir para o incremento do dano neural por um mecanismo ainda desconhecido e, uma correlação positiva entre concentrações séricas de TNF-α e desmielinização em pacientes com hanseníase já foi demonstrada. IFN-γ e TNF-α são citocinas capazes de induzir a expressão de Indoleamina 2,3 dioxigenase (IDO1), enzima chave na regulação da via das quinureninas, em diversos tipos celulares como monócitos, macrófagos e células dendríticas. Diversos estudos envolvendo patologias do sistema nervoso central apontam que as quinureninas produzidas pela degradação do triptofano podem ter uma função neurotóxica, mas pouco se sabe sobre o envolvimento de IDO1 e seus metabólitos na patogênese de doenças do sistema nervoso periférico. O presente estudo teve como objetivo avaliar a possível contribuição de IDO1 e seus metabólitos na neuropatia hanseniana. Inicialmente foi demonstrado que M. leprae aumenta a expressão de IDO1 em células de Schwann primárias e da linhagem ST88-14. No entanto, o bacilo não é capaz de aumentar a atividade de IDO1 em células de Schwann da linhagem ST88-14.
Foi observado que as citocinas pró-inflamatórias IFN-γ e TNF-α isoladamente não são capazes de induzir a expressão proteica de IDO1, mas aumentam significativamente sua atividade em células ST88-14. Em associação com M. leprae, IFN-γ exerce um forte estímulo na indução da atividade enzimática de IDO1. A infecção com M. leprae diminui a expressão gênica de Quinurenina aminotransferase II (AADAT), sugerindo que o mesmo possa estar direcionando a via para a produção de metabólitos neurotóxicos como o ácido quinolínico (QUINA), 3-hidroxiquinurenina (3-HK) e ácido 3-hidroxiantranílico (3HAA). A análise de viabilidade celular demonstrou que 3-HAA é capaz de induzir apoptose em células ST88-14 e, a análise por ELISA, dos sobrenadantes de 24h de cultura, demonstrou que M. leprae viável induz aumento na concentração do metabólito ácido quinurênico (KYNA) que é significativamente reduzida na presença de IFN-γ, enquanto IFN-γ aumenta significativamente a concentração de QUINA, principalmente quando associado à M. leprae morto. Foi observado um aumento na atividade de IDO1 em soro de pacientes com neuropatia hanseniana em relação a pacientes com outras neuropatias periféricas. Uma correlação positiva foi observada entre a atividade de IDO1 e a gravidade do dano neural, conforme avaliado pelo exame de eletroneuromiografia. Em conjunto, os dados apresentados sugerem o envolvimento da via das quinureninas no dano neural na hanseníase. (AU)
Subject(s)
Humans , Schwann Cells , Indoleamine-Pyrrole 2,3,-Dioxygenase , Kynurenine , Leprosy , Mycobacterium lepraeABSTRACT
Os cimentos dentários e ortopédicos são utilizados amplamente em diversas aplicações clínicas. Novos cimentos vêm sendo propostos visando à preservação ou regeneração tecidual. Contudo, pouco se conhece sobre o papel desses biomateriais na regeneração nervosa. As células mais comumente envolvidas na regeneração nervosa são as células de Schwann (SCs) sendo sua principal função o suporte aos axônios através da liberação de fatores de crescimento e isolamento axonal através da formação da bainha de mielina. Como estratégia da presente pesquisa, foi estudado um cimento à base da quitosana com adição de substâncias que podem atuar sinergicamente na resposta celular nervosa, tais como, as nanopartículas (NPs) de hidroxiapatita e o óxido de zinco, visto que têm propriedades bioativas e biocondutoras, além de promoverem a condução de prolongamento axonal. A doxiciclina (Dox) foi acrescida como antimicrobiano, potente inibidora de metaloproteinases (MMPs) e estimuladora da diferenciação celular no processo de regeneração tecidual. Assim, as propriedades físico-químicas e biológicas do cimento de nano-hidroxiapatita, quitosana, óxido de zinco e doxiciclina foram avaliadas, bem como a capacidade de promover um ambiente favorável para as células nervosas periféricas. Os cimentos foram caracterizados físico-químicamente mediante a determinação do pH, tempo de presa e solubilidade, lixiviação de íons cálcio, liberação controlada de doxiciclina, difração de Raios X, Termogravimetria (TG), espectroscopia Raman, molhabibidade, e testes de atividade biológica, para assim também serem avaliados em contato com células nervosas de Schwann (HS-Sch-2). O cimento apresentou pH neutro (7,0), tempo de presa de 5,7 ± 0,22 minutos, solubilidade menor que 3%, lixiviação de cálcio de 8,14 ± 0,71 mg L-1 após 14 dias, estabilidade térmica e a análise espectroscópica ratificou a presença e diferenciação das estruturas químicas dos componentes do cimento coerentemente com as imagens das análises microscópicas. Além disso, o cimento se mostrou hidrofílico, teve efeito hemolítico baixo (17%), obteve alta citocompabilidade celular em fibroblastos ATCC 3T3 (72%) e ação antimicrobiana. O cimento aumentou significativamente o crescimento das células de Schwann, 48,6% a mais do que o grupo controle (p≤0.05), e maior capacidade metabólica na análise mitótica quando em contato com este material (33%). Pode-se concluir que o cimento proposto à base de quitosana contendo hidroxiapatita e óxido de zinco nanoparticulados com adição de doxiciclina obteve efeito bioativo em células de Schwann promovendo, assim, o crescimento e a atividade mitótica celular, sendo então um biomaterial promissor para estudos de remielinização de nervos periféricos e regeneração nervosa in vivo.
Dental and orthopedic cements are used widely in several clinical applications. New cements have been proposed aimed the tissue preservation or regeneration. Nevertheless, nerve regeneration is not well known. The cells most commonly used in nerve regeneration are Schwann cells (SCs) which represent glial cells in the peripheral nervous system, their main function being supporting axons by releasing growth factors and axonal isolation through the formation of the myelin sheath. As a strategy of this research, chitosan-based cement was studied with the addition of substances that can act synergistically in the nervous cell response, such as the hydroxyapatite and zinc oxide nanoparticles (NPs), since they have bioactive and bioconductive properties; in addition to furthermore, they promote the conduction of axonal prolongation. Doxycycline (Dox) was added as an antimicrobial, a potent inhibitor of MMPs, a stimulator of cell differentiation in the tissue regeneration process. Thus, the physical-chemical and biological properties of nanohydroxyapatite, chitosan, zinc oxide and doxycycline cements were evaluated, as well as the ability to promote a favorable environment for peripheral nerve cells. Blocks of cements were characterized physically and chemically by determining pH, setting time and solubility, calcium ions leaching, controlled release of doxycycline, X-ray diffraction, Thermogravimetry (TG), Raman spectroscopy, wetness, and biological activity tests, so they can also be evaluated in contact with Schwann nerve cells (HS-Sch-2). The cement showed neutral pH (7.0), setting time of 5.7 ± 0.22 minutes, solubility less than 3%, calcium leaching of 8.14 ± 0.71 mg L-1 after 14 days, stability thermal and spectroscopic analysis confirmed the presence and differentiation of the chemical structures of the cement components coherently with the images of the microscopic analysis. In addition, the cement was shown to be hydrophilic, had a low hemolytic effect (17%), and obtained high cell cytocompatibility in ATCC 3T3 fibroblasts (72%) and antimicrobial action. The cement significantly increased the growth of Schwann cells, 48.6% more than the control group (p≤0.05), and greater metabolic capacity in the mitotic analysis when in contact with this material (33%). It can be concluded that the proposed chitosan-based cement containing hydroxyapatite and zinc oxide nanoparticulated with the addition of doxycycline has a bioactive effect in Schwann cells, thus promoting cell growth and mitotic activity, thus being a promising biomaterial for studies of remyelinization of peripheral nerves and nerve regeneration in vivo.
Subject(s)
Schwann Cells , Stimulation, Chemical , Dental Cements , Nerve Regeneration , Doxycycline , Durapatite , ChitosanABSTRACT
BACKGROUND Although Mycobacterium leprae (ML) is well characterised as the causative agent of leprosy, the pathophysiological mechanisms underlying peripheral nerve damage still need further understanding. In vitro and in vivo studies have yielded insights into molecular mechanisms of ML interaction with Schwann cells (SC), indicating the regulation of genes and proteins crucial to neural plasticity. OBJECTIVES We aimed to investigate the effect of ML on neurotrophins expression in human SC (hSC) and mice sciatic nerves to better understand their role in leprosy neuropathy, and aiming to contribute to future therapeutic approaches. METHODS We evaluated mRNA and protein expression of BDNF, NGF, NT-3, NT-4 in hSC from amputation nerve fragments, as well as in athymic nude mice, infected by ML for eight months. FINDINGS and MAIN CONCLUSIONS Our in vitro results showed a trend to decline in NGF and BDNF mRNA in ML-treated hSC, compared to controls. The immunodetection of BDNF and NT-4 was significantly downregulated in ML-treated hSC. Conversely, ML-infected mice demonstrated upregulation of NT-3, compared to non-infected animals. Our findings indicate that ML may be involved in neurotrophins regulation, suggesting that a pathogen-related imbalance of these growth factors may have a role in the neural impairment of leprosy.
Subject(s)
Humans , Animals , Mice , Schwann Cells/metabolism , Sciatic Nerve/metabolism , Mycobacterium leprae , Nerve Growth Factors/metabolism , Mice, NudeABSTRACT
Charcot-Marie-Tooth disease (CMT) is the commonest form of inherited neuropathy and has an incidence of 1/2500. CMT1A is the commonest subtype of CMT, which is caused by duplication of peripheral myelin protein 22 (PMP22) gene and accounts for approximately 50% of CMT diagnosed by genetic testing. Duplication of PMP22 may influence the production of PMP22 mRNA and protein, and interfere with the proliferation, differentiation and apoptosis of Schwann cells. In addition, deregulation of NRG1/ErbB pathway and lipid metabolism can also lead to dysfunction of Schwann cells. Such factors may disturb the myelination process, leading to axon degeneration, muscle weakness, and atrophy subsequently. Accordingly, drug therapies for CMT1A are developed by targeting such factors. PXT3003, antisense oligonucleotides (ASOs) and small interfering RNA (siRNA) are supposed to down-regulate the level of PMP22 mRNA, while recombinant human NRG-1 (rhNRG1) and neurotrophin-3 (NT-3) may enhance Schwann cells survival and differentiation. In addition, lipid-supplemented diet may remedy the defect of lipid metabolism and maintain the proper structure of myelin. Other targeting drugs include ascorbic acid, progesterone antagonists, IFB-088, ADX71441, and ACE-083. This review is to sum up the pathogenesis of CMT1A and promising targeting drug therapies for further research.
Subject(s)
Cell Differentiation , Charcot-Marie-Tooth Disease , Genetics , Pathology , Therapeutics , Genetic Testing , Humans , Schwann Cells , Cell BiologyABSTRACT
Granular cell tumor (GCT) is a rare soft tissue neoplasm of Schwann cell origin. Most cases occur in adults; however, the precise incidence is unknown in children. GCT is usually a slow-growing, painless tumor involving the skin and soft tissues that is mostly located in the head and neck region, especially the tongue. The breast is one of the least common sites involved by GCT. This paper presents a 3-year-old girl who presented with a soft to firm, ill-defined swelling on the right breast with painful ulceration of the overlying skin. Fine needle aspiration rendered an initial diagnosis of fibrocystic change accompanied by apocrine metaplasia. Histologic evaluation of the excised breast mass revealed a benign granular cell tumor. Although rare, GCT of the breast should be included in the differential diagnosis for breast masses in pediatric patients. Proper diagnosis and timely management of this tumor are essential because of its malignant potential (<2% of cases) and high rate of local recurrence if not properly excised.
Subject(s)
Humans , Female , Child, Preschool , Breast Neoplasms/pathology , Granular Cell Tumor/pathology , Schwann Cells/pathology , S100 ProteinsABSTRACT
A gangliocytic paraganglioma is a benign tumor of the digestive system with a very low incidence. The tumor is histopathologically characterized by a triphasic pattern consisting of epithelioid, ganglion, and spindle-shaped Schwann cells. In most cases, it occurs in the second portion of the duodenum near the ampulla of Vater. We report a case of a gangliocytic paraganglioma occurring at the minor duodenal papilla (a rare location) with a concurrent adenoma of the ampulla of Vater. Both lesions were treated simultaneously using endoscopic resection. Additionally, we have presented a literature review.
Subject(s)
Adenoma , Ampulla of Vater , Digestive System , Duodenum , Ganglion Cysts , Incidence , Pancreatic Ducts , Paraganglioma , Schwann CellsABSTRACT
OBJECTIVE@#To investigate the formation of gap junctions between Schwann cells derived from differentiated adipose stem cells implanted in a rat model of dyskinesia induced by brain injury and its positive effect in promoting functional recovery of the rats.@*METHODS@#In a rat model of hemiplegia induced by motor cortex injury, adipose stem cells or Schwann cells differentiated from adipose stem cells, either with or without RNAi-mediated silencing of Cx43, were transplanted orthotopically in the lesion. The recovery of the motor function of the rats was observed and scored after the transplantation. Rat brain tissues were sampled to detect the expressions of nerve growth factor (NGF) using Western blotting and RT-PCR.@*RESULTS@#All the 3 cell transplantation therapies obviously improved the motor function scores of the rats as compared with the control rats. The expression of NGF in the brain tissue was significantly lower in the control group than in the cell transplantation groups. NGF expression in the brain tissues of rats receiving transplantation of Schwann cells with Cx43 gene silencing was lower than that in rats receiving Schwann cells without Cx43 silencing, and was similar with that in rats transplanted with adipose stem cells. The results of RT-PCR showed that NGF mRNA level in the control group was significantly lower than that in the other 3 groups. NGF mRNA expression was the highest in Schwann cell group without Cx43 silencing, followed by adipose stem cell group, and then by Schwann cell group with Cx43 silencing.@*CONCLUSIONS@#In the rat model of dyskinesia induced by brain injury, transplantations of adipose stem cells and adipose stem cells-derived Schwann cells both promote the functional recovery of brain damage, in which gap junction protein Cx43 plays an important role to promote functional gap junction formation possibly by enhancing NGF expression.
Subject(s)
Animals , Brain Injuries , Dyskinesias , Gap Junctions , Rats , Rats, Sprague-Dawley , Schwann Cells , Stem CellsABSTRACT
OBJECTIVE@#To investigate the mechanism of high glucose affecting the apoptosis of schwann cells through Nox4 NADPH oxidase.@*METHODS@#The schwann cells of newborn Wistar rats were cultured in vitro. The cultured cells were divided into four groups: control group, high-glucose group, NOX4 siRNA group and control siRNA group (n=10). The WST-1 method was used to detect the cell vitality, and the DCFH-DA method was used to detect the contents of intracellular reactive oxygen free radicals (ROS). Nox4 and Caspase3 mRNA expressions were detected by real-time fluorescence quantitative RT-PCR. Nox4 and Caspase3 protein expressions were determined by Western blot.@*RESULTS@#High glucose culture up-regulated Nox4 mRNA and protein expressions of schwann cells, decreased activity of schwann cells, increased intracellular ROS content, and promoted apoptosis by increasing Caspase3 mRNA and protein expressions. NOX4 siRNA blocked the accumulation of ROS in the high glucose cultured schwann cells, and reduced the damage of glucose on cell viability, by inhibiting NOX4 gene expression. NOX4 siRNA also reduced cell apoptosis by down-regulating Caspase3 mRNA and protein expressions.@*CONCLUSION@#Nox4 was involved in the hyperglycemic-induced apoptosis of schwann cells through ROS. The regulation of Nox4 expression or function might be a new way to treat diabetic peripheral neuropathy.
Subject(s)
Animals , Apoptosis , Caspase 3 , Metabolism , Cells, Cultured , Culture Media , Glucose , NADPH Oxidase 4 , Metabolism , Rats , Rats, Wistar , Reactive Oxygen Species , Metabolism , Schwann Cells , Cell Biology , MetabolismABSTRACT
Schwannoma is a benign nerve sheath tumor composed of schwann cells. Most schwannoma arising in the middle ear are facial nerve schwannoma. In very rare occasions, schwannoma of the middle ear can arise from chorda tympani nerve. Hearing loss and tinnitus are the most common symptoms of patients with schwannoma of chorda tympani nerve and it can be treated by surgical excision. Recently, we treated a male patient with schwannoma of the chorda tympani nerve. This is the first case of schwannoma of the chorda tympani nerve reported in Korea. Herein, we present the case in detail with a review of the related literature.