Coordinated Regulation of Myelination by Growth Factor and Amino-acid Signaling Pathways / 神经科学通报·英文版

Myelin-forming oligodendrocytes in the central nervous system (CNS) and Schwann cells in the peripheral nervous system (PNS) are essential for structural and functional homeostasis of nervous tissue. Albeit with certain similarities, the regulation of CNS and PNS myelination is executed differently. Recent advances highlight the coordinated regulation of oligodendrocyte myelination by amino-acid sensing and growth factor signaling pathways. In this review, we discuss novel insights into the understanding of differential regulation of oligodendrocyte and Schwann cell biology in CNS and PNS myelination, with particular focus on the roles of growth factor-stimulated RHEB-mTORC1 and GATOR2-mediated amino-acid sensing/signaling pathways. We also discuss recent progress on the metabolic regulation of oligodendrocytes and Schwann cells and the impact of their dysfunction on neuronal function and disease.

Human Platelet-Rich Plasma-Derived Exosomes Promote the Proliferation of Schwann Cells Cultured in Vitro / 中国医学科学院学报

Objective To investigate the effect of human platelet-rich plasma-derived exosomes(PRP-exos)on the proliferation of Schwann cell(SC)cultured in vitro. Methods PRP-exos were extracted by polymerization-precipitation combined with ultracentrifugation.The morphology of PRP-exos was observed by transmission electron microscopy,and the concentration and particle size distribution of PRP-exos were determined by nanoparticle tracking analysis.Western blotting was employed to determine the expression of the marker proteins CD63,CD81,and CD9 on exosome surface and the platelet membrane glycoprotein CD41.The SCs of rats were isolated and cultured,and the expression of the SC marker S100β was detected by immunofluorescence staining.The fluorescently labeled PRP-exos were co-cultured with SCs in vitro for observation of their interaction.EdU assay was employed to detect the effect of PRP-exos on SC proliferation,and CCK-8 assay to detect the effects of PRP-exos at different concentrations(0,10,20,40,80,and 160 μg/ml)on SC proliferation. Results The extracted PRP-exos appeared as uniform saucer-shaped vesicles with the average particle size of(122.8±38.7)nm and the concentration of 3.5×1012 particles/ml.CD63,CD81,CD9,and CD41 were highly expressed on PRP-exos surface(P<0.001,P=0.025,P=0.004,and P=0.032).The isolated SCs expressed S100β,and PRP-exos could be taken up by SCs.PRP-exos of 40,80,and 160 μg/ml promoted the proliferation of SCs,and that of 40 μg/ml showed the best performance(all P<0.01). Conclusions High concentrations of PRP-exos can be extracted from PRP.PRP-exos can be taken up by SCs and promote the proliferation of SCs cultured in vitro.

Cellular Schwannoma of Buccal Mucosa: A Rare Histopathological Variant

Introduction: Schwannoma (Neurilemmoma) is a benign neoplasm that develop from schwann cells in the peripheral nerve sheath. It commonly occurs as an encapsulated, slow-growing and generally solitary lesion. Cellular schwannoma is a rare histopathological variant of schwannoma. Case Presentation: Here, we discuss a case of 44-year-old female patient who reported with the chief complaint of swelling in the left upper back cheek region for the past 2 years. Histopathological and immunohistochemical analysis confirmed the diagnosis as cellular schwannoma. Management and prognosis: Surgical excision of the lesion was performed and no recurrence was reported after 1 year of follow up. Conclusion: Cellular schwannoma a rare intraoral benign tumor, needs to be differentiated from other malignant tumor with a careful approach for a prompt diagnosis and proper management of the lesion

Research status of the role of Schwann cells in leprosy immunity / 公共卫生与预防医学

Mycobacterium leprae is virtually non-toxic. After invading the human body, it can grow and reproduce in large quantities in the tissues but does not cause any clinical symptoms. The manifestations of skin, mucous membrane and peripheral nerve damage of leprosy are mainly caused by the immune response of the body to the leprae. Schwann cells can support and nourish nerve fibers. As an important parasitic site of leprosy bacteria, Schwann cells are closely related to leprosy immunity, and the research on these cells is of great significance.

Signal pathways related to regeneration after peripheral nerve injury / 药学实践杂志

Due to the limited self-repair ability of neurons after injury, there has been a lack of effective treatments for nerve injury in clinical practice. So, to find drugs that promote the repair after nerve injury has become a research hotspot. Schwann cells and neurons play an important role in regeneration of the peripheral nerves after injury. This review summarizes the classification of peripheral nerve injury, the signaling pathways related to peripheral nerve regeneration in Schwann cells and neurons as well as diseases related to peripheral nerve injury, and provides a basis for further exploration of the regeneration mechanism after peripheral nerve injury.

Effect of electroacupuncture combined with Schwann cell transplantation on limb locomotor ability, regional remyelination and expression of spinal CD4 and CD8 proteins in compressive spinal injury rats / 针刺研究

OBJECTIVE: To observe the effect of electroacupuncture (EA) combined with transplantation of Schwann cells (SCs) on limb locomotor, myelin sheath repair and expression of CD4 and CD8 in compressed spinal cord injury (CSCI) rats, so as to explore its mechanisms underlying improvement of CSCI. METHODS: A total of 45 female SD rats were randomly divided into normal control, model, EA, Schwann cell (SC) transplantation, and EA＋SC transplantation groups (n＝9 rats in each group). The CSCI model was established by laminectomy at T12-L2 and clip compression. Rats of the SC transplantation group accepted injection of the cultured SC suspension (2×106/6 µL) into the central, upper and lower sites of the injured spinal cord (5 mm in depth) 7-8 days after CSCI modeling. EA (2 Hz) was applied to bilateral "Zusanli" (ST36) and "Sanyinjiao" (SP6) for 10 min, once daily and 6 days a week for 3 weeks. The Basso, Beattie and Bresnahan locomotor rating scale (BBB scale) was used to evaluate the function state of CSCI. Morphological changes of the regional injured tissue were observed under light microscope after H．E. staining. The myelin sheath repair state and survival of SCs were detected by Luxol fast blue (LFB) staining and immunofluorescence histochemistry, and the expression of CD4, CD8 and P0 of the injured spinal cord was detected by Western blot. RESULTS: Compared with the normal control group, the BBB scores at the time-points of 0 d, and 1, 2, and 3 weeks were significantly decreased in the model group (P0.05). LFB staining showed a disordered arrangement of the nerve fibers in the white matter, myelinociasis and obvious decrease of the medullated fibers in the model group, and these situations were relatively milder in both EA and SC transplantation groups and obviously milder in the EA＋SC transplantation group. H．E. staining displayed that the structure of the injured region of the spinal cord was incomplete, accompanied with a large number of defect cavities and neuronal karyopyknosis in the model group, while the structure was relatively clear, with an increase of the normal neurons and fewer neuronal karyopyknosis in the EA＋SC transplantation group. Compared with the normal control group, MBP in the model group was significantly decreased (P0.05), while after the intervention and in comparison with the model group, the expression levels of P0 protein were significantly increased in the EA, SC transplantation and EA＋SC transplantation groups (P<0.05), and was significantly higher in the EA＋SC transplantation group than in both EA and SC transplantation groups (P<0.05). The expression levels of CD4 and CD8 proteins were significantly lower in the EA＋SC transplantation group than in the SC transplantation group (P<0.05)．. CONCLUSION: EA＋SCs transplantation can improve the locomotor function in CSCI rats, which may be related to its effects in increasing the survival of transplanted SCs to promote the remyelination and in reducing the immune rejecting reaction.

Apigenin protects schwann cells against the effect of high glucose-induced cell injury through inhibiting NF-κB signal pathway / 西安交通大学学报(医学版)

Objective: To investigate the protective effects of apigenin against the cell injury of schwann cells cultured with high glucose so as to provide preliminary experimental basis for treatment of diabetic peripheral neuropathy by apigenin. Methods: RSC96 cells were primarily cultured and randomly divided into three groups respectively treated with 5.6 mmol/L glucose as the control group; with 50mmol /L glucose as high glucose (HG) group; and with HG in the presence of 0.1, 1.0, and 10.0 μmol/L apigenin as Api group. Cell viability of RSC96 cells was detected by CCK-8 assay. Cell apoptosis was detected by flow cytometry. The effects of apigenin on the expression levels of NGF and TNF-α in RSC96 cells cultured with high glucose were detected by ELISA assay. The protein and mRNA expression levels of Bcl-2, Bax, NF-κB, p-NF-κB, and NF-κB were examined by Western blotting and qRT-PCR. Results: Compared with that of HG group, apigenin at low concentrations (≤1.0 μmol/L) significantly increased cell viability in the dose-dependent manner (P<0.05), but apigenin of 10.0 μmol/L had no obvious effect on cell viability of high glucose-induced RSC96 cells; apigenin of 1.0 μmol/L remarkably inhibited high glucose-induced RSC96 cell apoptosis. Apigenin remarkably increased the protein and mRNA expression levels of Bcl-2 in glucose-induced RSC96 cells (P<0.05), but decreased the Bax protein and mRNA expression levels (P<0.05). Moreover, apigenin significantly increased the NGF expression level, and decreased TNF-α expression (P<0.05). In addition, apigenin notably suppressed the phosphorylation level of NF-κB (P<0.05). Conclusion: Apigenin can increase cell viability, inhibit cell apoptosis, and regulate the expression levels of NGF and TNF-α in high glucose-induced schwann cells. Its potential mechanism is possibly related with inhibiting NF-κB signal pathway.

Intraparotid facial nerve schwannomas

Schwannoma is a benign tumor rarely found in the head and neck and much less commonly found in the intraparotid facial nerve. It is a slow-growing encapsulated tumor originating from the Schwann cells or axonal nerve sheath. It can occur anywhere along the course of the facial nerve. Patients may present with symptoms of facial palsy, but the most common presenting symptom is an asymptomatic swelling. Diagnosis is usually difficult before surgical removal and histopathological examination. We report a rare case of intraparotid facial nerve schwannoma in a 57-year-old female who had sustained a mass of the right preauricular area for 3 years. She reported no pain or facial muscle weakness. Enhanced computed tomography findings revealed the impression of pleomorphic adenoma. However, intraoperative gross findings were not characteristic of pleomorphic adenoma, and a frozen biopsy was performed resulting in the impression of a nerve sheath tumor. We performed an extracapsular surgical excision without parotidectomy. Permanent histopathology and immunohistochemistry reports diagnosed the mass as schwannoma. There were no complications including facial palsy after surgery. No recurrence was found at 6 months after surgery

Schwann Cells Enhance Penetration of Regenerated Axons into Three-Dimensional Microchannels

Nerve regeneration after injury requires proper axon alignment to bridge the lesion site and myelination to achieve functional recovery. Transplanted scaffolds with aligned channels, have been shown to induce axon growth to some extent. However, the penetration of axons into the microchannels remain a challenge, influencing the functional recovery of regenerated nerves. We previously demonstrated that the size of microchannels exerts significant impact on Schwann cells (SCs) migration. Here we demonstrate that migration of SCs promotes, significantly, the dorsal root ganglion (DRG) neurons to extend axons into three-dimensional channels and form aligned fascicular-like axon tracts. Moreover, the migrating SCs attach and wrap around the aligned axons of DRG neurons in the microchannels and initiate myelination. The SCs release growth factors that provide chemotactic signals to the regenerating axons, similar to the response achieved with nerve growth factor (NGF), but with the additional capability of promoting myelination, thereby demonstrating the beneficial effects of including SCs over NGF alone in enhancing axon penetration and myelination in three-dimensional microchannels.

The effect of gestational diabetes mellitus on sciatic nerve in adult offspring rats / Efecto de la diabetes mellitus gestacional sobre el nervio ciático en ratas adultas

Gestational diabetes mellitus (GDM) is one form of diabetes affect approximately 7 % of pregnancies. Diabetic peripheral neuropathy (DPN) is a common complication of diabetes that is associated with loss of nerve fibers, myelin abnormalities and significant decrease in the expression of myelin basic protein (MBP) in peripheral nerves. This study was done to determine the effect of induced diabetes during pregnancy on sciatic nerve in adult rat offspring. In this study, wistar rats' dams were allocated to control and diabetic groups. Diabetic rats were received 40 mg/kg/body weight of streptozotocin (STZ) on the first day of gestation. Six offspring of each group were randomly selected on 12 weeks postnatal and histopathological changes in their nerve tissue were examined through H&E staining and transmission electron microscopy. Furthermore, the expression of MBP in sciatic nerve was examined by immunohistochemistry. We found that the myelinated fiber number of sciatic nerve in offspring of diabetic rats was reduced compared to the controls, but this difference was not significant. The average thickness of the myelin sheath of sciatic nerve fibers in the control and GDM was 97.1±0.1and 94.1±0.2 µm, respectively that the difference was not statistically significant. The expression of MBP protein in the myelin sheath of both groups was similar. TEM results showed that myelin sheath of diabetic offspring had not any changes compared to control. Atrophy of axons and schwannocytus (Schwann cells) alterations were not observed in diabetic offspring. Induction of diabetes during pregnancy reduced the number of nerve fibers and thickness of the myelin sheath. But it has no effect on MBP expression and schwannocytus morphology.

La diabetes mellitus gestacional (DMG) es una forma de diabetes que afecta aproximadamente al 7 % de los embarazos. La neuropatía periférica diabética (NPD) es una complicación frecuente de la diabetes asociada a la pérdida de fibras nerviosas, anomalías de la mielina y disminución significativa de la expresión de la proteína básica de mielina (PBM) en los nervios periféricos. Este estudio se realizó para determinar el efecto de la diabetes inducida durante el embarazo en el nervio ciático en descendientes de ratas adultas. Las ratas Wistar madres fueron asignadas a los grupos control y diabéticas. Las ratas diabéticas recibieron 40 mg/kg/peso corporal de estreptozotocina (STZ) el primer día de gestación. Seis descendientes de cada grupo fueron seleccionados al azar en la semana 12 postnatal y los cambios histopatológicos en su tejido nervioso se examinaron a través de tinción H-E y microscopía electrónica de transmisión. Además, la expresión de PBM en el nervio ciático se examinó mediante inmunohistoquímica. Se encontró que el número de fibras mielinizadas de nervio ciático en descendientes de ratas diabéticas se redujo en comparación con los controles, pero esta diferencia no fue significativa. El espesor medio de la vaina de mielina de las fibras nerviosas ciáticas en el control y DMG fue de 97,1±0,1 y 94,1±0,2 µm, respectivamente, y la diferencia no fue estadísticamente significativa. La expresión de la proteína PBM en la vaina de mielina de ambos grupos fue similar. Los resultados del TEM mostraron que la vaina de mielina de la descendencia diabética no tuvo ningún cambio en comparación con el control. La atrofia de los axones y las alteraciones de los schwannocitos (células de Schwann) no se observaron en descendientes diabéticos. La inducción de diabetes durante el embarazo redujo el número de fibras nerviosas y el grosor de la vaina de mielina. Pero no tiene ningún efecto sobre la expresión de PBM y la morfología de las schwannocitos.

Pyrroloquinoline quinone inhibited oxidative stress induced-apoptosis of Schwann cells via mitochondrial apoptotic signaling pathway in vitro / 中华整形外科杂志

Objective@#To investigate the mechanisms of Pyrroloquinoline quinone (PQQ) against oxidative stress induced apoptosis in Schwann cells (SCs).@*Methods@#SCs were cultured in vitro, identified by S-100 immunofluorence staining. SCs were divided into control group, H2O2 induced group, H2O2 + PQQ treated group. CCK-8 assay was used to detect cell proliferation. Apoptosis was detected by flow cytometry with Annecin V-FITC/PI staining, mitochondrial transmembrane potential was detected by flow cytometry with JC-1 labeled staining, cytochrome C (CytC), Bax and Caspase-9 protein levels was detected by Western blot analysis.@*Results@#In this study, the S-100 positive cells were more than 95%, cell proliferation was decreased in H2O2 induced SCs, apoptotic rate was increased, mitochondrial transmembrane potential was decreased, CytC, Bax and Caspase-9 protein levels were increased. After PQQ added, cell proliferation was increased, apoptotic rate decreased, mitochondrial transmembrane potential increased, CytC, Bax and Caspase-9 protein levels decreased.@*Conclusions@#PQQ protects SCs from oxidative induced apoptosis by inhibiting mitochondrial signaling pathway.

Persistencia de epónimos en terminologia histologica / Eponyms persistence in terminologia histologica

El uso de epónimos aún es una práctica frecuentemente utilizada entre médicos clínicos y académicos para referirse a las distintas estructuras en histología. A pesar de los esfuerzos por parte de la comunidad morfológica por desarraigarlos del lenguaje médico, hoy en día se encuentran, inclusive presentes en Terminologia Histologica, tal como en los casos de Schannocytus (H2.00.06.2.02003) referente a la Célula de Schwann; Complexus golgiensis (H1.00.01.3.0146) referente al Aparato de Golgi, Cellula panethensis (H3.04.03.0.00017) referente a la Célula de Paneth, y Neuron purkinjense (H3.11.03.4.01015) referente a la Neurona de Purkinje, que aluden a los investigadores Theodor Schwann, Camillo Golgi, Joseph Paneth y Jan Evangelista Purkinje, respectivamente. El objetivo del presente estudio fue realizar un análisis de los términos antes nombrados desde un punto de vista lingüístico y proponer nuevas denominaciones, siguiendo los parámetros establecidos en la Terminología, en la cual los nombres de las estructuras deben tener un valor informativo, estar escritos en latín como lengua base y eliminar el uso de los epónimos. Los términos analizados, se refieren a nombres de células u organelos frecuentemente utilizados en textos educativos, sin embargo, son poco descriptivos, muchos de ellos con raíces netamente griegas y otros neologismos, cuyas denominaciones, por consenso y en honor a investigadores connotados han perdurado en el tiempo. Proponemos modificaciones con respecto a su denominación, así como a sus derivados, utilizando términos procedentes del latín. En resumen, pretendemos que con estos antecedentes iniciales puedan entregarse argumentos que permitan seguir unificando criterios y que ellos puedan ser considerados por los expertos que conforman el Programa Federativo Internacional de Terminología Anatómica y, como bien se señala, permitir el establecimiento de diálogo con los miembros de la Federación Internacional de Asociaciones de Anatomistas e ir mejorando la comunicación científica entre los diferentes actores de las ciencias morfológicas.

Eponyms are still frequently used among clinicians and scholars to refer to the various structures in histology. Despite efforts by the morphological community to eradicate eponyms from medical language, nowadays they are practical, and even present in Terminologia Histologica (TH), such as in the case of Schannocytus (H2.00.06.2.02003) concerning the term Schwann cell; Complexus golgiensis (H1.00.01.3.0146) relating to the Golgi apparatus, Cellula panethensis (H3.04.03.0.00017) concerning the Paneth cell and Neuron purkinjense (H3.11.03.4.01015), the term Purkinje neuron which refers to researchers Theodor Schwann, Camillo Golgi, Joseph Paneth and Jan Evangelist Purkinje, respectively. The aim of this study was to conduct an analysis of these terms from a linguistic point of view and propose new Latin names, following guidelines established in the terminology wherein the names of structures must, have an informative value, be written in Latin as a base language, and eliminate the use of eponyms. The terms analyzed, refer to cells or organelles names frequently used, they have limited descriptive value, many with purely Greek roots and other neologisms, which names have endured over time in honor of renowned researchers. Using terms from Larin, we propose modifications with respect to classification and derivatives. In conclusion, we hope that with this introduction, the information to consolidate standards will be considered by the experts of the Federal International Committee on Anatomical Terminology and further, initiate a dialogue with International Federation of Associations of Anatomists members, while encouraging ongoing communication between the various players of morphological sciences.

Role of hydrogen gas in regulating of poly (ADP-ribose) polymerase-1 dependent cell death in rat Schwann cells / 中华危重病急救医学

Objective To investigate the protective effects and underlying molecular mechanisms of hydrogen (H2) on high glucose-induced poly (ADP-ribose) polymerase-1 (PARP-1) dependent cell death (PARthanatos) in primary rat Schwann cells. Methods Cultured primary rat Schwann cells were randomly divided into five groups: blank control group (C group), H2 control group (H2 group), high osmotic control group (M group), high glucose treatment group (HG group), and H2 treatment group (HG+H2 group). The cells in H2 group and HG+H2 group were cultured with saturated hydrogen-rich medium containing 0.6 mmol/L of H2, and those in three control groups were cultured with low sugar DMEM medium containing 5.6 mmol/L of sugar, and the cells in HG and HG+H2 groups were given 44.4 mmol/L of glucose in addition (the medium containing 50 mmol/L of glucose), the cells in C group and H2 group were given the same volume of normal saline, and the cells in M group were given the same volume of mannitol. Cytotoxicity was evaluated using lactate dehydrogenase (LDH) release rate assays after treatment for 48 hours in each group. The contents of peroxynitrite (ONOO-) and 8-hydroxy-2-deoxyguanosine (8-OHdG) reflecting oxidative stress injury and DNA damage were detected by enzyme linked immunosorbent assay (ELISA). Poly (ADP-ribose) (PAR) protein expression was analyzed by Western Blot, and immunofluorescence staining was used to determine the nuclear translocation of the apoptosis-inducing factor (AIF). Results The cytotoxicity in HG and HG+H2 groups was significantly increased as compared with that of C group [LDH release rate: (61.40±2.89)%, (42.80±2.32)% vs. (9.92±0.38)%, both P < 0.01], the levels of ONOO- and 8-OHdG were markedly elevated [ONOO- (ng/L): 853.58±51.00, 553.11±38.66 vs. 113.56±14.22; 8-OHdG (ng/L): 1 177.37±60.97, 732.06±54.29 vs. 419.67±28.77, all P < 0.01], and the PAR protein expression was up-regulated (A value: 0.603±0.028, 0.441±0.010 vs. 0.324±0.021, both P < 0.01). The cytotoxicity, the levels of ONOO- and 8-OHdG, and PAR expression in HG+H2 group were significantly lower than those of the HG group (all P < 0.01). There were no significant differences in above parameters between H2 group as well as M group and C group. It was shown by immunofluorescence that AIF was expressed in the cytoplasm in C group, H2 group and M group, AIF was expressed in the whole cell in HG group, and the expression in the nucleus was particularly increased. A small amount of AIF expression was found in the nucleus of HG+H2 group, which indicated that high glucose could promote the AIF nuclear translocation, and that hydrogen-rich medium could prevent the process of translocation. Conclusions High glucose levels could enhance DNA damage that enhance PARthanatos in primary rat Schwann cells. However, H2 can not only reduce DNA damage of injured cells, but also inhibit the special death process, reduce the cell toxicity, all of which have protective effects.

Tetramethylpyrazine protects Schwann cells from ischemia-like injury and increases cell survival in cold ischemic rat nerves

Tetramethylpyrazine (TMP), a major active ingredient of Ligusticum wallichi Franchat extract (a Chinese herb), exhibits neuroprotective properties in ischemia. In this study, we assessed its protective effects on Schwann cells (SCs) by culturing them in the presence of oxygen glucose deprivation (OGD) conditions and measuring cell survival in cold ischemic rat nerves. In the OGD-induced ischemic injury model of SCs, we demonstrated that TMP treatment not only reduced OGD-induced cell viability losses, cell death, and apoptosis of SCs in a dose-dependent manner, and inhibited LDH release, but also suppressed OGD-induced downregulation of Bcl-2 and upregulation of Bax and caspase-3, as well as inhibited the consequent activation of caspase-3. In the cold ischemic nerve model, we found that prolonged cold ischemic exposure for four weeks was markedly associated with the absence of SCs, a decrease in cell viability, and apoptosis in preserved nerve segments incubated in University of Wisconsin solution (UWS) alone. However, TMP attenuated nerve segment damage by preserving SCs and antagonizing the decrease in nerve fiber viability and increase in TUNEL-positive cells in a dose-dependent manner. Collectively, our results indicate that TMP not only provides protective effects in an ischemia-like injury model of cultured rat SCs by regulating Bcl-2, Bax, and caspase-3, but also increases cell survival and suppresses apoptosis in the cold ischemic nerve model after prolonged ischemic exposure for four weeks. Therefore, TMP may be a novel and effective therapeutic strategy for preventing peripheral nervous system ischemic diseases and improving peripheral nerve storage.

Tetrametilpirazina (TMP), o principal componente do extrato de Ligusticum wallichi Franchat (erva chinesa), apresenta propriedades neuroprotetoras na isquemia. Nesse estudo, avaliamos seus efeitos protetores nas células de Schwann (SC), cultivando-as na presença de condições de depleção de oxigênio da glicose (OGD) e medindo a sobrevivência dos nervos de ratos isquêmicos pelo resfriamento. No modelo de lesão isquêmica em SC induzida por OGD, demonstramos que o tratamento com TMP não somente reduziu as perdas de viabilidade celular induzida por OGD, a morte celular, a apoptose de SC dose-dependente e inibiu a liberação de LDH, mas, também, suprimiu a infra-regulação do Vcl-2 e a supra-regulação de Bax e caspase-3, e inibiu a consequente ativação da caspase-3. No modelo de nervo isquêmico por resfriamento, observamos que a exposição prolongada ao resfriamento por quatro semanas estava, marcadamente, associada com a ausência de SC, com o decréscimo da viabilidade celular e a apoptose em segmentos de nervo incubados na solução da Universidade de Wisconsin apenas. Entretanto, a TMP atenuou o dano no segmento do nervo preservando SC e antagonizando a diminuição da viabilidade da fibra nervosa e o aumento das células TUNEL-positiva de modo dose-dependente. De forma conjunta, nossos resultados indicam que o TMP não só fornece efeitos protetores em um modelo de dano semelhante à isquemia de SC de ratos cultivados pela regulação de BCl-2, Bax e caspase 3, mas, também, aumenta a sobrevivência celular e suprime a apoptose no modelo de isquemia por resfriamento por exposição prolongada por quatro semanas. Então, TMP pode ser uma estratégia terapêutica eficaz para prevenir doenças isquêmicas do sistema nervoso periférico e melhora a armazenagem do nervo periférico.

Differentiation of adipose-derived stem cells into Schwann-like cells: fetal bovine serum or human serum? / 대한해부학회지

Access to autologous Schwann cells is limited due to lack of donor site and its difficult isolation and culture. Therefore, one of the possible ways to obtain to Schwann cells is to differentiate mesenchymal stem cells into glial pathway using various materials and protocols. The aim of this study was to compare the effects of fetal bovine serum and human serum on Schwann cell differentiation of adipose-derived stem cells to choose the best serum for use in future research. For this purpose, after isolation of human adipose-derived stem cells, it was characterized and differentiated into Schwann cell lineage using two protocols which one of them contained fetal bovine serum and the other human serum. At the end, morphological evaluation declared an increased detachment of cells in response to human serum. On the other side, immunocytochemistry showed that there was a significant increase in the number of cells expressing glial fibrillary acidic proteins and S100 in fetal bovine serum-treated group when compared to human serum-treated one (P<0.05). It was concluded that fetal bovine serum was more effective than allogeneic human serum in Schwann cell differentiation of adipose-derived stem cells.

Repairment of sciatic nerve defect by Schwann cell of adult rat combined with acellular nerve grafts / 器官移植

Objective To investigate clinical efficacy of tissue-engineered artificial nerve grafts constructed by acellular nerve grafts combined with adult rat Schwann cell (SC)in the treatment of peripheral nerve injury.Methods SCs were isolated and cultured from the distal nerves of adult Sprague Dawley (SD) rats with 1-week Wallerian degeneration and then combined with acellular nerve grafts to construct tissue-engineered artificial nerve.All rats were divided into acellular nerve graft containing SCs (SC group)and nerve graft containing no cells groups (control group),five animals in each group.At 2-,4-and 8-week after surgery,sciatic function index (SFI)of the affected side was compared between two groups.At postoperative 8 weeks,nerve conduction of sciatic nerve of the injured side,recovery rate of triceps surae wet weight and other relevant parameters were equally compared between two groups.Results In the SC group,SFI of the affected side at 2-,4-and 8-week after surgery,nerve conduction of sciatic nerve at the injured side and recovery rate of triceps surae wet weight at postoperative 8 weeks were significantly better compared with those in the control group (all in P <0.05).Conclusions Combined use of adult rat SCs and acellular nerve grafts effectively repairs peripheral nerve defects and accelerates functional recovery of injured nerves.

Induction of Schwann cell-like differentiation in bone mesenchymal stem cell of adult rat in vitro / 器官移植

[Abstract ] Objective To explore the effective method of induction of Schwann cell-like differentiation in bone mesenchymal stem cell (BMSC)of adult rat in vitro.Methods Primary culture of Schwann cell and isolated culture of BMSC were separately conducted.According to different induction methods,the cells were divided into chemical induction group and co-culture induction group.The growth of Schwann cell and BMSC was observed under light microscope.These two kinds of cells were identified by immunofluorescence staining [detecting Schwann cell marker proteins:glial fibrillary acidic protein (GFAP) antibody and S-100 antibody] and flow cytometry.The shape and growth of cells in two groups were dynamically observed by light microscope.The induced differentiation was evaluated with immunofluorescence staining at 3 rd day after co-culture induction in the co-culture induction group and at 4 h and 1 st day after chemical induction in the chemical induction group.Results In the chemical induction group,the BMSC appeared typical Schwann cell-like morphology.The positive expression of GFAP antibody appeared at 4 h after preliminary induction.Meanwhile,the positive expression rate of GFAP and S-100 antibody was (80.9 ± 3.5)% and (59.0 ±1.1 )% at 1 st day after induction.The induced BMSC began to die at 2nd day after chemical induction and most of the induced BMSC had died at 3 rd day after chemical induction.At 3 rd day after co-culture induction,few induced BMSC showed obvious morphological changes like those in chemical induction group.The positive expression rate of GFAP and S-100 antibody was (89.8 ±2.4)% and (80.9 ±1.7)%. The positive expression rate of GFAP and S-100 antibody in the co-culture induction group was higher than those in the chemical induction group and the difference had statistical significance (all in P <0.01).Conclusions The co-culture induction not only has obvious effect on Schwann cell-like differentiation in BMSC,but also promotes the survival and proliferation of BMSC.Thus,co-culture induction is more safe and effective than chemical induction.

Cutaneous peripheral nerve sheath tumors in 15 dogs / 대한수의학회지

Peripheral nerve sheath tumors (PNSTs) are heterogeneous tumor groups of peripheral nerves that originate from either Schwann cells or modified Schwann cells, fibroblasts, or perineural cells. In this study, signalment and clinical data such as tumor location and size were evaluated for 15 cases of PNSTs collected from local animal hospitals. The mean age of dogs with malignant PNST was higher than that of dogs with benign PNST. Additionally, the male to female ratio in dogs with PNST was 1 : 4. In dogs with PNST, the primary sites of involvement were the hindlimb, forelimb, around the mammary glands, the neck, and the abdomen. Histiopathologic examination revealed that eight PNSTs were benign and seven were malignant. The tumor cells were composed of loosely to densely arranged interlacing bundles and wavy spindle cells arranged in short bundles, palisading, and whirling. High mitotic figures, local invasion, multifocal necrosis and atypical multinucleated giant cells were observed in malignant PNST cases. All PNSTs showed immunoreactivity for vimentin and S-100. However, only 93.3% and 73.3% were immunoreactive for NSE and GFAP, respectively. Overall, these results indicated that immunohistochemical markers such as vimentin, S-100 and NSE could help confirm the diagnosis of canine PNSTs.

Mitogen Activated Protein Kinase Family Proteins and c-jun Signaling in Injury-induced Schwann Cell Plasticity

Schwann cells (SCs) in the peripheral nerves myelinate axons during postnatal development to allow saltatory conduction of nerve impulses. Well-organized structures of myelin sheathes are maintained throughout life unless nerves are insulted. After peripheral nerve injury, unidentified signals from injured nerves drive SC dedifferentiation into an immature state. Dedifferentiated SCs participate in axonal regeneration by producing neurotrophic factors and removing degenerating nerve debris. In this review, we focus on the role of mitogen activated protein kinase family proteins (MAP kinases) in SC dedifferentiation. In addition, we will highlight neuregulin 1 and the transcription factor c-jun as upstream and downstream signals for MAP kinases in SC responses to nerve injury.

Schwannomatosis del pie / Schwannomatosis of the foot

Se describe el caso clínico de un paciente de 34 años de edad, quien presentaba múltiples schwannomas en el tercer ramo de bifurcación de la rama interna del nervio musculocutáneo, así como en los nervios colateral dorsal externo e interno del segundo y tercer dedos del pie derecho, respectivamente, atendido en el Servicio de Ortopedia del Hospital General Docente "Dr. Juan Bruno Zayas Alfonso de Santiago de Cuba. Se realizó la exéresis quirúrgica de 50 lesiones de diferentes tamaños aproximadamente. A los 45 días de operado habían desaparecido las molestias y pudo reincorporarse a sus actividades laborales habituales.

The case report of a 34-year patient who presented multiple schwannomas in the third bifurcation branch of the internal ramus of the musculocutaneous nerve, as well as in the external and internal dorsal collateral nerves of the right second and third toes, respectively, assisted in the Orthopedics Service from "Dr. Juan Bruno Zayas Alfonso" Teaching General Hospital in Santiago de Cuba is described. The surgical exeresis of 50 lesions of approximately different sizes was carried out. Fourty five days after surgery the discomfort had disappeared and he could return to his habitual working activities.