RESUMEN
Diabetic peripheral neuropathy (DPN) is a common nerve-damaging complication of diabetes mellitus. Effective treatments are needed to alleviate and reverse diabetes-associated damage to the peripheral nerves. Curcumin is an effective neuroprotectant that plays a protective role in DPN promoted by Schwann cells (SCs) lesions. However, the potential molecular mechanism of curcumin remains unclear. Therefore, our aim is to study the detailed molecular mechanism of curcumin-mediated SCs repair in order to improve the efficacy of curcumin in the clinical treatment of DPN. First, candidate target genes of curcumin in rat SC line RSC96 cells stimulated by high glucose were identified by RNA sequencing and bioinformatic analyses. Enrichment analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) was carried out by Metascape, followed by 8 algorithms on Cytoscape to determine 4 hub genes, namly Hmox1, Pten, Vegfa and Myc. Next, gene set enrichment analysis (GSEA) and Pearson function showed that Hmox1 was significantly correlated with apoptosis. Subsequently, qRT-PCR, MTT assay, flow cytometry, caspase-3 activity detection and westernblot showed that curcumin treatment increased RSC96 cell viability, reduced cell apoptosis, increased Hmox1, Pten, Vegfa and Myc expression, and up-regulated Akt phosphorylation level under high glucose environment. Finally, molecular docking predicted the binding site of curcumin to Hmox1. These results suggest that curcumin can reduce the apoptosis of SCs induced by high glucose, and Hmox1 is a potential target for curcumin. Our findings provide new insights about the mechanism of action of curcumin on SC as a potential treatment in DPN.
Asunto(s)
Biología Computacional , Curcumina , Neuropatías Diabéticas , Células de Schwann , Curcumina/farmacología , Animales , Neuropatías Diabéticas/tratamiento farmacológico , Neuropatías Diabéticas/metabolismo , Ratas , Células de Schwann/efectos de los fármacos , Células de Schwann/metabolismo , Apoptosis/efectos de los fármacos , Línea Celular , Simulación del Acoplamiento Molecular , Fosfohidrolasa PTEN/metabolismo , Fosfohidrolasa PTEN/genética , Glucosa/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Factor A de Crecimiento Endotelial Vascular/genética , Supervivencia Celular/efectos de los fármacos , Fármacos Neuroprotectores/farmacologíaRESUMEN
Regenerative medicine is continuously looking for new natural, biocompatible and possibly biodegradable materials, but also mechanically compliant. Chitosan is emerging as a promising FDA-approved biopolymer for tissue engineering, however, its exploitation in regenerative devices is limited by its brittleness and can be further improved, for example by blending it with other materials or by tuning its superficial microstructure. Here, we developed membranes made of chitosan (Chi) and glycerol, by solvent casting, and micro-patterned them with directional geometries having different levels of axial symmetry. These membranes were characterized by light microscopies, atomic force microscopy (AFM), by thermal, mechanical and degradation assays, and also testedin vitroas scaffolds with Schwann cells (SCs). The glycerol-blended Chi membranes are optimized in terms of mechanical properties, and present a physiological-grade Young's modulus (≈0.7 MPa). The directional topographies are effective in directing cell polarization and migration and in particular are highly performant substrates for collective cell migration. Here, we demonstrate that a combination of a soft compliant biomaterial and a topographical micropatterning can improve the integration of these scaffolds with SCs, a fundamental step in the peripheral nerve regeneration process.
Asunto(s)
Materiales Biocompatibles , Movimiento Celular , Quitosano , Módulo de Elasticidad , Glicerol , Regeneración Nerviosa , Células de Schwann , Ingeniería de Tejidos , Andamios del Tejido , Cicatrización de Heridas , Quitosano/química , Células de Schwann/citología , Glicerol/química , Animales , Materiales Biocompatibles/química , Andamios del Tejido/química , Ratas , Ingeniería de Tejidos/métodos , Microscopía de Fuerza Atómica , Ensayo de Materiales , Membranas Artificiales , Medicina Regenerativa/métodosRESUMEN
This study aimed to investigate the therapeutic potential of human adipose-derived mesenchymal stem cells (hADSCs) modified with recombinant adeno-associated virus (rAAV) carrying the vascular endothelial growth factor 165 (VEGF165) gene in peripheral nerve injury (PNI). The hADSCs were categorized into blank, control (transduced with rAAV control vector), and VEGF165 (transduced with rAAV VEGF165 vector) groups. Subsequently, Schwann cell differentiation was induced, and Schwann cell markers were assessed. The sciatic nerve injury mouse model received injections of phosphate-buffered saline (PBS group), PBS containing hADSCs (hADSCs group), rAAV control vector (control-hADSCs group), or rAAV VEGF165 vector (VEGF165-hADSCs group) into the nerve defect site. Motor function recovery, evaluated through the sciatic function index (SFI), and nerve regeneration, assessed via toluidine blue staining along with scrutiny of Schwann cell markers and neurotrophic factors, were conducted. Modified hADSCs exhibited enhanced Schwann cell differentiation and elevated expression of Schwann cell markers [S100 calcium-binding protein B (S100B), NGF receptor (NGFR), and glial fibrillary acidic protein (GFAP)]. Mice in the VEGF165-hADSCs group demonstrated improved motor function recovery compared to those in the other three groups, accompanied by increased fiber diameter, axon diameter, and myelin thickness, as well as elevated expression of Schwann cell markers (S100B, NGFR, and GFAP) and neurotrophic factors [mature brain-derived neurotrophic factor (BDNF) and glial cell-derived neurotrophic factor (GDNF)] in the distal nerve segment. rAAV-VEGF165 modification enhances hADSC potential in PNI, promoting motor recovery and nerve regeneration. Elevated Schwann cell markers and neurotrophic factors underscore therapy benefits, providing insights for nerve injury strategies.
Asunto(s)
Diferenciación Celular , Dependovirus , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas , Traumatismos de los Nervios Periféricos , Células de Schwann , Factor A de Crecimiento Endotelial Vascular , Humanos , Dependovirus/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo , Factor A de Crecimiento Endotelial Vascular/genética , Células Madre Mesenquimatosas/metabolismo , Células Madre Mesenquimatosas/citología , Animales , Traumatismos de los Nervios Periféricos/terapia , Traumatismos de los Nervios Periféricos/metabolismo , Traumatismos de los Nervios Periféricos/genética , Células de Schwann/metabolismo , Ratones , Regeneración Nerviosa , Tejido Adiposo/citología , Tejido Adiposo/metabolismo , Vectores Genéticos , Nervio Ciático/lesiones , Nervio Ciático/patología , MasculinoRESUMEN
Perineural invasion (PNI) is a new approach of cervical cancer invasion and metastasis, involving the cross-talk between tumor and nerve. However, the initiating signals and cellular interaction mechanisms of PNI remain largely elusive. The nerve-sparing radical hysterectomy (NSRH) proposed to improve postoperative quality of life is only applicable to cervical cancer patients without PNI. Therefore, it is important to elucidate the underlying mechanisms initiating PNI, and suggest the effective biomarkers to predict PNI before NSRH surgery. Here, we found that PNI is the characteristic of advanced cervical cancer, and Schwann cells were the antecedent cells that initiating PNI. Further, neuropeptide neuromedin B (NMB) produced by cervical cancer cells was determined to induce PNI by reprogramming Schwann cells, including driving their morphological and transcriptional changes, promoting their proliferation and migration, and initiating PNI by secreting CCL2 and directing axon regeneration. Mechanistically, cervical cancer cells-produced NMB activated its receptor NMBR in Schwann cells, and opened the T-type calcium channels to stimulate Ca2+ influx through PKA signaling, which could be blocked by the inhibitor. Clinically, combined examination of serum NMB and CCL2 levels was suggested to effectively predict PNI in cervical cancer patients. Our data demonstrate that cervical cancer-produced NMB initiates the reprograming of Schwann cells, which then direct axon regeneration, thus causing PNI onset. The elevated serum NMB and CCL2 levels may be useful for the decision-making to nerve sparing during hysterectomy surgery of cervical cancer patients.
Asunto(s)
Invasividad Neoplásica , Neuroquinina B , Células de Schwann , Neoplasias del Cuello Uterino , Células de Schwann/metabolismo , Células de Schwann/patología , Neoplasias del Cuello Uterino/metabolismo , Neoplasias del Cuello Uterino/patología , Femenino , Humanos , Animales , Neuroquinina B/metabolismo , Neuroquinina B/análogos & derivados , Ratones , Movimiento Celular , Proliferación Celular , Línea Celular TumoralRESUMEN
BACKGROUND: Neuroblastoma (NB) is a heterogeneous embryonal malignancy and the deadliest tumor of infancy. It is a complex disease that can result in diverse clinical outcomes. In some children, tumors regress spontaneously. Others respond well to existing treatments. But for the high-risk group, which constitutes approximately 40% of all patients, the prognosis remains dire despite collaborative efforts in basic and clinical research. While its exact cellular origin is still under debate, NB is assumed to arise from the neural crest cell lineage including multipotent Schwann cell precursors (SCPs), which differentiate into sympatho-adrenal cell states eventually producing chromaffin cells and sympathoblasts. METHODS: To investigate clonal development of neuroblastoma cell states, we performed haplotype-specific analysis of human tumor samples using single-cell multi-omics, including joint DNA/RNA sequencing of sorted single cells (DNTR-seq). Samples were also assessed using immunofluorescence stainings and fluorescence in-situ hybridization (FISH). RESULTS: Beyond adrenergic tumor cells, we identify subpopulations of aneuploid SCP-like cells, characterized by clonal expansion, whole-chromosome 17 gains, as well as expression programs of proliferation, apoptosis, and a non-immunomodulatory phenotype. CONCLUSION: Aneuploid pre-malignant SCP-like cells represent a novel feature of NB. Genetic evidence and tumor phylogeny suggest that these clones and malignant adrenergic populations originate from aneuploidy-prone cells of migrating neural crest or SCP origin, before lineage commitment to sympatho-adrenal cell states. Our findings expand the phenotypic spectrum of NB cell states. Considering the multipotency of SCPs in development, we suggest that the transformation of fetal SCPs may represent one possible mechanism of tumor initiation in NB with chromosome 17 aberrations as a characteristic element.
Asunto(s)
Perfilación de la Expresión Génica , Neuroblastoma , Células de Schwann , Análisis de la Célula Individual , Humanos , Neuroblastoma/genética , Neuroblastoma/patología , Neuroblastoma/metabolismo , Células de Schwann/metabolismo , Células de Schwann/patología , Transcriptoma , Regulación Neoplásica de la Expresión Génica , Hibridación Fluorescente in SituRESUMEN
Diabetic peripheral neuropathy (DPN) is a complication of diabetes mellitus that lacks specific treatment, its high prevalence and disabling neuropathic pain greatly affects patients' physical and mental health. Schwann cells (SCs) are the major glial cells of the peripheral nervous system, which play an important role in various inflammatory and metabolic neuropathies by providing nutritional support, wrapping axons and promoting repair and regeneration. Increasingly, high glucose (HG) has been found to promote the progression of DPN pathogenesis by targeting SCs death regulation, thus revealing the specific molecular process of programmed cell death (PCD) in which SCs are disrupted is an important link to gain insight into the pathogenesis of DPN. This paper is the first to review the recent progress of HG studies on apoptosis, autophagy, pyroptosis, ferroptosis and necroptosis pathways in SCs, and points out the crosstalk between various PCDs and the related therapeutic perspectives, with the aim of providing new perspectives for a deeper understanding of the mechanisms of DPN and the exploration of effective therapeutic targets.
Asunto(s)
Neuropatías Diabéticas , Células de Schwann , Células de Schwann/metabolismo , Células de Schwann/patología , Humanos , Neuropatías Diabéticas/terapia , Neuropatías Diabéticas/patología , Neuropatías Diabéticas/metabolismo , Neuropatías Diabéticas/etiología , Animales , Apoptosis , Muerte Celular , Autofagia/fisiología , Necroptosis/fisiologíaRESUMEN
Neuritin, also known as candidate plasticity gene 15 (CPG15), was first identified as one of the activity-dependent gene products in the brain. Previous studies have been reported that Neuritin induces neuritogenesis, neurite arborization, neurite outgrowth and synapse formation, which are involved in the development and functions of the central nervous system. However, the role of Neuritin in peripheral nerve injury is still unknown. Given the importance and necessity of Schwann cell dedifferentiation response to peripheral nerve injury, we aim to investigate the molecular mechanism of Neuritin steering Schwann cell dedifferentiation during Wallerian degeneration (WD) in injured peripheral nerve. Herein, using the explants of sciatic nerve, an ex vivo model of nerve degeneration, we provided evidences indicating that Neuritin vividly accelerates Schwann cell dedifferentiation. Moreover, we found that Neuritin promotes Schwann cell demyelination as well as axonal degeneration, phagocytosis, secretion capacity. In summary, we first described Neuritin acts as a positive regulator for Schwann cell dedifferentiation and WD after peripheral nerve injury.
Asunto(s)
Desdiferenciación Celular , Neuropéptidos , Fosfatidilinositol 3-Quinasas , Proteínas Proto-Oncogénicas c-akt , Células de Schwann , Nervio Ciático , Transducción de Señal , Serina-Treonina Quinasas TOR , Degeneración Walleriana , Células de Schwann/metabolismo , Células de Schwann/patología , Degeneración Walleriana/metabolismo , Degeneración Walleriana/patología , Animales , Serina-Treonina Quinasas TOR/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Neuropéptidos/metabolismo , Neuropéptidos/genética , Nervio Ciático/lesiones , Nervio Ciático/metabolismo , Nervio Ciático/patología , Proteínas Ligadas a GPI/metabolismo , Proteínas Ligadas a GPI/genética , Ratas , Traumatismos de los Nervios Periféricos/metabolismo , Traumatismos de los Nervios Periféricos/patología , Ratas Sprague-Dawley , Axones/metabolismo , Axones/patología , Masculino , Fagocitosis , RatonesRESUMEN
The sympathetic nervous system controls bodily functions including vascular tone, cardiac rhythm, and the "fight-or-flight response". Sympathetic chain ganglia develop in parallel with preganglionic motor nerves extending from the neural tube, raising the question of whether axon targeting contributes to sympathetic chain formation. Using nerve-selective genetic ablations and lineage tracing in mouse, we reveal that motor nerve-associated Schwann cell precursors (SCPs) contribute sympathetic neurons and satellite glia after the initial seeding of sympathetic ganglia by neural crest. Motor nerve ablation causes mispositioning of SCP-derived sympathoblasts as well as sympathetic chain hypoplasia and fragmentation. Sympathetic neurons in motor-ablated embryos project precociously and abnormally towards dorsal root ganglia, eventually resulting in fusion of sympathetic and sensory ganglia. Cell interaction analysis identifies semaphorins as potential motor nerve-derived signaling molecules regulating sympathoblast positioning and outgrowth. Overall, central innervation functions both as infrastructure and regulatory niche to ensure the integrity of peripheral ganglia morphogenesis.
Asunto(s)
Ganglios Simpáticos , Neuronas Motoras , Cresta Neural , Células de Schwann , Sistema Nervioso Simpático , Animales , Sistema Nervioso Simpático/embriología , Ratones , Neuronas Motoras/fisiología , Células de Schwann/metabolismo , Cresta Neural/citología , Cresta Neural/metabolismo , Ganglios Simpáticos/citología , Ganglios Espinales , Semaforinas/metabolismo , Semaforinas/genética , Ratones Transgénicos , Neuroglía/metabolismo , FemeninoRESUMEN
Neurofibromatosis Type 1 (NF1) is a complex genetic disorder characterized by the development of benign neurofibromas, which can cause significant morbidity in affected individuals. While the molecular mechanisms underlying NF1 pathogenesis have been extensively studied, the development of effective therapeutic strategies remains a challenge. This paper presents the development and validation of a novel biomaterial testing model to enhance our understanding of NF1 pathophysiology, disease mechanisms and evaluate potential therapeutic interventions. Our long-term goal is to develop an invitro model of NF1 to evaluate drug targets. We have developed an in vitro system to test the cellular behavior of NF1 patient derived cells on electroconductive aligned nanofibrous biomaterials with electrical stimulatory cues. We hypothesized that cells cultured on electroconductive biomaterial will undergo morphological changes and variations in cell proliferation that could be further enhanced with the combination of exogenous electrical stimulation (ES). In this study, we developed electrospun Hyaluronic Acid-Carbon Nanotube (HA-CNT) nanofiber scaffolds to mimic the axon's topographical and bioelectrical cues that influence neurofibroma growth and development. The cellular behavior was qualitatively and quantitively analyzed through immunofluorescent stains, Alamar blue assays and ELISA assays. Schwann cells from NF1 patients appear to have lost their ability to respond to electrical stimulation in the development and regeneration range, which was seen through changes in morphology, proliferation and NGF release. Without stimulation, the conductive material enhances NF1 SC behavior. Wild-type SC respond to electrical stimulation with increased cell proliferation and NGF release. Using this system, we can better understand the interaction between axons and SC that lead to tumor formation, homeostasis and regeneration.
Asunto(s)
Proliferación Celular , Estimulación Eléctrica , Ácido Hialurónico , Nanotubos de Carbono , Células de Schwann , Células de Schwann/metabolismo , Nanotubos de Carbono/química , Humanos , Ácido Hialurónico/química , Nanofibras/química , Neurofibromatosis 1/patología , Neurofibromatosis 1/metabolismo , Andamios del Tejido/química , Células Cultivadas , Materiales Biocompatibles/químicaRESUMEN
Plexiform neurofibromas (PNFs) are a prevalent and severe phenotype associated with NF1, characterized by a high teratogenic rate and potential for malignant transformation. The growth and recurrence of PNFs are attributed to aberrant proliferation and migration of Nf1-deficient Schwann cells. Protein tyrosine phosphatase receptor S (PTPRS) is believed to modulate cell migration and invasion by inhibiting the EMT process in NF1-derived malignant peripheral nerve sheath tumors. Nevertheless, the specific role of PTPRS in NF1-derived PNFs remains to be elucidated. The study utilized the GEO database and tissue microarray to illustrate a decrease in PTPRS expression in PNF tissues, linked to tumor recurrence. Furthermore, the down- and over-expression of PTPRS in Nf1-deficient Schwann cell lines resulted in the changes of cell migration and EMT processes. Additionally, RTK assay and WB showed that PTPRS knockdown can promote EGFR expression and phosphorylation. The restoration of EMT processes disrupted by alterations in PTPRS levels in Schwann cells can be achieved through EGFR knockdown and EGFR inhibitor. Moreover, high EGFR expression has been significantly correlated with poor prognosis. These findings underscore the potential role of PTPRS as a tumor suppressor in the recurrence of PNF via the regulation of EGFR-mediated EMT processes, suggesting potential targets for future clinical interventions.
Asunto(s)
Movimiento Celular , Transición Epitelial-Mesenquimal , Receptores ErbB , Neurofibroma Plexiforme , Células de Schwann , Humanos , Línea Celular Tumoral , Receptores ErbB/metabolismo , Receptores ErbB/genética , Regulación Neoplásica de la Expresión Génica , Recurrencia Local de Neoplasia/patología , Recurrencia Local de Neoplasia/genética , Neurofibroma Plexiforme/patología , Neurofibroma Plexiforme/genética , Neurofibroma Plexiforme/metabolismo , Neurofibromatosis 1/genética , Neurofibromatosis 1/metabolismo , Neurofibromatosis 1/patología , Neurofibromina 1/genética , Neurofibromina 1/metabolismo , Fosforilación , Proteínas Tirosina Fosfatasas Clase 2 Similares a Receptores/genética , Proteínas Tirosina Fosfatasas Clase 2 Similares a Receptores/metabolismo , Células de Schwann/metabolismo , Células de Schwann/patología , Transducción de SeñalRESUMEN
Peripheral nerve injury is a major societal concern. Black phosphorus (BP) has inherent advantages over cell-based therapies in regenerative medicine. However, controlling spontaneous degradation and size-dependent cytotoxicity remains challenging and poses difficulties for clinical translation. In this study, we constructed zero-dimensional BP quantum dots (QDs) modified with antioxidant ß-carotene and comprehensively investigated them in Schwann cells (SCs) to elucidate their potential for peripheral nerve repair. In vitro experiments demonstrated that BPQD@ß-carotene has an inappreciable toxicity and good biocompatibility, favoring neural regrowth, angiogenesis, and inflammatory regulation of SCs. Furthermore, the PI3K/Akt and Ras/ERK1/2 signaling pathways were activated in SCs at the genetic, protein, and metabolite levels. The BPQD@ß-carotene-embedded GelMA/PEGDA scaffold enhanced functional recovery by promoting axon remyelination and regeneration and facilitating intraneural angiogenesis in peripheral nerve injury models of rats and beagle dogs. These results contribute to advancing knowledge of BP nanomaterials in tissue regeneration and show significant potential for application in translational medicine.
Asunto(s)
Antioxidantes , Regeneración Nerviosa , Traumatismos de los Nervios Periféricos , Fósforo , Puntos Cuánticos , Ratas Sprague-Dawley , Células de Schwann , Animales , Regeneración Nerviosa/efectos de los fármacos , Puntos Cuánticos/química , Traumatismos de los Nervios Periféricos/metabolismo , Traumatismos de los Nervios Periféricos/tratamiento farmacológico , Traumatismos de los Nervios Periféricos/patología , Antioxidantes/farmacología , Antioxidantes/química , Ratas , Perros , Fósforo/química , Células de Schwann/efectos de los fármacos , Células de Schwann/metabolismo , Masculino , Células CultivadasRESUMEN
Electrical excitability-the ability to fire and propagate action potentials-is a signature feature of neurons. How neurons become excitable during development and whether excitability is an intrinsic property of neurons remain unclear. Here, we demonstrate that Schwann cells, the most abundant glia in the peripheral nervous system, promote somatosensory neuron excitability during development. We find that Schwann cells secrete prostaglandin E2, which is necessary and sufficient to induce developing somatosensory neurons to express normal levels of genes required for neuronal function, including voltage-gated sodium channels, and to fire action potential trains. Inactivating this signaling pathway in Schwann cells impairs somatosensory neuron maturation, causing multimodal sensory defects that persist into adulthood. Collectively, our studies uncover a neurodevelopmental role for prostaglandin E2 distinct from its established role in inflammation, revealing a cell non-autonomous mechanism by which glia regulate neuronal excitability to enable the development of normal sensory functions.
Asunto(s)
Potenciales de Acción , Dinoprostona , Células de Schwann , Células Receptoras Sensoriales , Animales , Células de Schwann/metabolismo , Dinoprostona/metabolismo , Ratones , Células Receptoras Sensoriales/metabolismo , Transducción de SeñalRESUMEN
Investigating disease progression, transmission of infection and impacts of Multidrug Therapy (MDT) to inhibit demyelination in leprosy involves a certain amount of difficulty in terms of the in-built uncertain complicated and complex intracellular cell dynamical interactions. To tackle this scenario and to elucidate a more realistic, rationalistic approach of examining the infection mechanism and associated drug therapeutic interventions, we propose a four-dimensional ordinary differential equation-based model. Stochastic processes has been employed on this deterministic system by formulating the Kolmogorov forward equation introducing a transition state and the quasi-stationary distribution, exact distribution analysis have been investigated which allow us to estimate an expected time to extinction of the infected Schwann cells into the human body more prominently. Additionally, to explore the impact of uncertainty in the key intracellular factors, the stochastic system is investigated incorporating random perturbations and environmental noises in the disease dissemination, proliferation and reinfection rates. Rigorous numerical simulations validating the analytical outcomes provide us significant novel insights on the progression of leprosy and unravelling the existing major treatment complexities. Analytical experiments along with the simulations utilizing Monte-Carlo method and Euler-Maruyama scheme involving stochasticity predicts that the bacterial density is underestimated due to the recurrence of infection and suggests that maintaining a drug-efficacy rate in the range 0.6-0.8 would be substantially efficacious in eradicating leprosy.
Asunto(s)
Lepra , Modelos Biológicos , Células de Schwann , Procesos Estocásticos , Humanos , Células de Schwann/microbiología , Lepra/microbiología , Lepra/tratamiento farmacológico , Conceptos Matemáticos , Método de Montecarlo , Mycobacterium lepraeRESUMEN
INTRODUCTION: Peripheral nerve injury (PNI) occurs in approximately 3% of all trauma patients and can be challenging to treat, particularly when injury is severe such as with a long-segmental gap. Although peripheral nerves can regenerate after injury, functional recovery is often insufficient, leading to deficits in the quality of life of patients with PNI. Although nerve autografts are the gold standard of care, there are several disadvantages to their use, namely a lack of autologous nerve material for repair. This has led to the pursuit of alternative treatment methods such as axon guidance channels (AGCs). Second-generation AGCs have been shown to be able to deliver growth-enhancing substrates for nerve repair directly to the injury site. Although our laboratory has had success with second-generation AGCs filled with Schwann cells (SCs), SCs have their own set of issues clinically. Because of this, we have begun to utilize SC-derived exosomes as an alternative, as they have the appropriate protein markers, associate to axons in high concentrations, and are able to improve nerve regeneration. However, it is unknown how SC-derived exosomes may react within second-generation AGCs; thus, the aim of the present study was to assess the ability of SC-derived exosomes to be loaded into a second-generation AGC and how they would distribute within it. MATERIALS AND METHODS: A total of 4 dry second-generation AGCs were loaded with SC-derived exosomes that were derived from green fluorescent protein (GFP)-labeled SCs. They were subsequently frozen and sliced before imaging. RESULTS: Here, we present findings that SC-derived exosomes can be loaded into second-generation AGCs through our established loading method utilizing negative pressure and are able to survive and equally distribute along the length of the AGC. CONCLUSIONS: Although only 4 second-generation AGCs were utilized, these findings indicate a potential use for SC-derived exosomes within second-generation AGCs to treat severe PNI. Future research should focus on exploring this in greater detail and in different contexts to assess the ability of SC-derived exosomes to survive at the site of injury and treat PNI.
Asunto(s)
Exosomas , Regeneración Nerviosa , Traumatismos de los Nervios Periféricos , Células de Schwann , Células de Schwann/fisiología , Regeneración Nerviosa/fisiología , Animales , Traumatismos de los Nervios Periféricos/terapia , Ratas , Orientación del Axón/fisiología , Axones/fisiologíaRESUMEN
Background: Inhibiting ROS overproduction is considered a very effective strategy for the treatment of peripheral nerve injuries, and Se has a remarkable antioxidant effect; however, since the difference between the effective concentration of Se and the toxic dose is not large, we synthesized a nanomaterial that can release Se slowly so that it can be used more effectively. Methods: Se@SiO2 NPs were synthesized using a mixture of Cu2-x Se nanocrystals, and the mechanism of action of Se@SiO2 NPs was initially explored by performing sequencing, immunofluorescence staining and Western blotting of cellular experiments. The mechanism of action of Se@SiO2 NPs was further determined by performing behavioral assays after animal experiments and by sampling the material for histological staining, immunofluorescence staining, and ELISA. The effects, mechanisms and biocompatibility of Se@SiO2 NPs for peripheral nerve regeneration were determined. Results: Porous Se@SiO2 was successfully synthesized, had good particle properties, and could release Se slowly. CCK-8 experiments revealed that the optimal experimental doses were 100 µM H2O2 and 200 µg/mL Se@SiO2, and RNA-seq revealed that porous Se@SiO2 was associated with cell proliferation, apoptosis, and the PI3K/AKT pathway. WB showed that porous Se@SiO2 could increase the expression of cell proliferation antigens (PCNA and S100) and antiapoptotic proteins (Bcl-2), decrease the expression of proapoptotic proteins (Bax), and increase the expression of antioxidative stress proteins (Nrf2, HO-1, and SOD2). EdU cell proliferation and ROS fluorescence assays showed that porous Se@SiO2 promoted cell proliferation and reduced ROS levels. The therapeutic effect of LY294002 (a PI3K/AKT pathway inhibitor) was decreased significantly and its effect was lost when it was added simultaneously with porous Se@SiO2. Animal experiments revealed that the regenerated nerve fiber density, myelin thickness, axon area, gastrocnemius muscle wet-to-weight ratio, myofiber area, sciatic nerve function index (SFI), CMAP, apoptotic cell ratio, and levels of antioxidative stress proteins and anti-inflammatory factors were increased following the administration of porous Se@SiO2. The levels of oxidative stress proteins and anti-inflammatory factors were significantly greater in the Se@SiO2 group than in the PNI group, and the effect of LY294002 was decreased significantly and was lost when it was added simultaneously with porous Se@SiO2. Conclusion: Se@SiO2 NPs are promising, economical and effective Se-releasing nanomaterials that can effectively reduce ROS production, inhibit apoptosis and promote cell proliferation after nerve injury via the PI3K/AKT pathway, ultimately accelerating nerve regeneration. These findings could be used to design new, promising drugs for the treatment of peripheral nerve injury.
Asunto(s)
Proliferación Celular , Regeneración Nerviosa , Traumatismos de los Nervios Periféricos , Fosfatidilinositol 3-Quinasas , Proteínas Proto-Oncogénicas c-akt , Selenio , Transducción de Señal , Dióxido de Silicio , Animales , Selenio/química , Selenio/farmacología , Dióxido de Silicio/química , Dióxido de Silicio/farmacología , Traumatismos de los Nervios Periféricos/tratamiento farmacológico , Fosfatidilinositol 3-Quinasas/metabolismo , Transducción de Señal/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt/metabolismo , Regeneración Nerviosa/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Ratas , Apoptosis/efectos de los fármacos , Antioxidantes/farmacología , Antioxidantes/química , Nanopartículas/química , Masculino , Preparaciones de Acción Retardada/farmacología , Preparaciones de Acción Retardada/química , Ratas Sprague-Dawley , Estrés Oxidativo/efectos de los fármacos , Nervio Ciático/efectos de los fármacos , Nervio Ciático/lesiones , Células de Schwann/efectos de los fármacos , Células de Schwann/metabolismoRESUMEN
Underexpression, overexpression, and point mutations in peripheral myelin protein 22 (PMP22) cause most cases of Charcot-Marie-Tooth disease (CMTD). While its exact functions remain unclear, PMP22 is clearly essential for formation and maintenance of healthy myelin in the peripheral nervous system. This review explores emerging evidence for roles of PMP22 in cholesterol homeostasis. First, we highlight dysregulation of lipid metabolism in PMP22-based forms of CMTD and recently-discovered interactions between PMP22 and cholesterol biosynthesis machinery. We then examine data that demonstrates PMP22 and cholesterol co-traffic in cells and co-localize in lipid rafts, including how disease-causing PMP22 mutations result in aberrations in cholesterol localization. Finally, we examine roles for interactions between PMP22 and ABCA1 in cholesterol efflux. Together, this emerging body of evidence suggests that PMP22 plays a role in facilitating enhanced cholesterol synthesis and trafficking necessary for production and maintenance of healthy myelin.
Asunto(s)
Enfermedad de Charcot-Marie-Tooth , Colesterol , Homeostasis , Proteínas de la Mielina , Células de Schwann , Colesterol/metabolismo , Humanos , Células de Schwann/metabolismo , Proteínas de la Mielina/metabolismo , Proteínas de la Mielina/genética , Enfermedad de Charcot-Marie-Tooth/metabolismo , Enfermedad de Charcot-Marie-Tooth/genética , Animales , Vaina de Mielina/metabolismo , Metabolismo de los Lípidos , Transportador 1 de Casete de Unión a ATP/metabolismo , Transportador 1 de Casete de Unión a ATP/genética , MutaciónRESUMEN
TFEB and TFE3 (TFEB/3), key regulators of lysosomal biogenesis and autophagy, play diverse roles depending on cell type. This study highlights a hitherto unrecognized role of TFEB/3 crucial for peripheral nerve repair. Specifically, they promote the generation of progenitor-like repair Schwann cells after axonal injury. In Schwann cell-specific TFEB/3 double knock-out mice of either sex, the TFEB/3 loss disrupts the transcriptomic reprogramming that is essential for the formation of repair Schwann cells. Consequently, mutant mice fail to populate the injured nerve with repair Schwann cells and exhibit defects in axon regrowth, target reinnervation, and functional recovery. TFEB/3 deficiency inhibits the expression of injury-responsive repair Schwann cell genes, despite the continued expression of c-jun, a previously identified regulator of repair Schwann cell function. TFEB/3 binding motifs are enriched in the enhancer regions of injury-responsive genes, suggesting their role in repair gene activation. Autophagy-dependent myelin breakdown is not impaired despite TFEB/3 deficiency. These findings underscore a unique role of TFEB/3 in adult Schwann cells that is required for proper peripheral nerve regeneration.
Asunto(s)
Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice , Ratones Noqueados , Regeneración Nerviosa , Traumatismos de los Nervios Periféricos , Células de Schwann , Células de Schwann/metabolismo , Animales , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/metabolismo , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética , Ratones , Traumatismos de los Nervios Periféricos/metabolismo , Regeneración Nerviosa/fisiología , Regeneración Nerviosa/genética , Masculino , Femenino , Autofagia/fisiología , Ratones Endogámicos C57BL , Nervio Ciático/lesionesRESUMEN
GRT-X, which targets both the mitochondrial translocator protein (TSPO) and the Kv7.2/3 (KCNQ2/3) potassium channels, has been shown to efficiently promote recovery from cervical spine injury. In the present work, we investigate the role of GRT-X and its two targets in the axonal growth of dorsal root ganglion (DRG) neurons. Neurite outgrowth was quantified in DRG explant cultures prepared from wild-type C57BL6/J and TSPO-KO mice. TSPO was pharmacologically targeted with the agonist XBD173 and the Kv7 channels with the activator ICA-27243 and the inhibitor XE991. GRT-X efficiently stimulated DRG axonal growth at 4 and 8 days after its single administration. XBD173 also promoted axonal elongation, but only after 8 days and its repeated administration. In contrast, both ICA27243 and XE991 tended to decrease axonal elongation. In dissociated DRG neuron/Schwann cell co-cultures, GRT-X upregulated the expression of genes associated with axonal growth and myelination. In the TSPO-KO DRG cultures, the stimulatory effect of GRT-X on axonal growth was completely lost. However, GRT-X and XBD173 activated neuronal and Schwann cell gene expression after TSPO knockout, indicating the presence of additional targets warranting further investigation. These findings uncover a key role of the dual mode of action of GRT-X in the axonal elongation of DRG neurons.
Asunto(s)
Axones , Ganglios Espinales , Receptores de GABA , Animales , Ganglios Espinales/metabolismo , Ganglios Espinales/citología , Ratones , Axones/metabolismo , Receptores de GABA/metabolismo , Receptores de GABA/genética , Canal de Potasio KCNQ2/metabolismo , Canal de Potasio KCNQ2/genética , Ratones Noqueados , Ratones Endogámicos C57BL , Células Cultivadas , Células de Schwann/metabolismo , Células de Schwann/efectos de los fármacos , Células de Schwann/citología , Técnicas de Cocultivo , Neuronas/metabolismo , Neuronas/efectos de los fármacosRESUMEN
The peripheral nervous system is a key regulator of cancer progression. In pancreatic ductal adenocarcinoma (PDAC), the sympathetic branch of the autonomic nervous system inhibits cancer development. This inhibition is associated with extensive sympathetic nerve sprouting in early pancreatic cancer precursor lesions. However, the underlying mechanisms behind this process remain unclear. This study aimed to investigate the roles of pancreatic Schwann cells in the structural plasticity of sympathetic neurons. We examined the changes in the number and distribution of Schwann cells in a transgenic mouse model of PDAC and in a model of metaplastic pancreatic lesions induced by chronic inflammation. Schwann cells proliferated and expanded simultaneously with new sympathetic nerve sprouts in metaplastic/neoplastic pancreatic lesions. Sparse genetic labeling showed that individual Schwann cells in these lesions had a more elongated and branched structure than those under physiological conditions. Schwann cells overexpressed neurotrophic factors, including glial cell-derived neurotrophic factor (GDNF). Sympathetic neurons upregulated the GDNF receptors and exhibited enhanced neurite growth in response to GDNF in vitro. Selective genetic deletion of Gdnf in Schwann cells completely blocked sympathetic nerve sprouting in metaplastic pancreatic lesions in vivo. This study demonstrated that pancreatic Schwann cells underwent adaptive reprogramming during early cancer development, supporting a protective antitumor neuronal response. These finding could help to develop new strategies to modulate cancer associated neural plasticity.