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We generated a human induced pluripotent stem cell (iPSC) line from the peripheral blood mononuclear cells isolated from a 59-year-old male patient with Alzheimer's disease (AD). The iPSC line was meticulously characterized to confirm its pluripotency, absence of transgenes, and normal karyotype. The unexpected discovery of the M232R variant in PRNP makes this cell line a valuable resource for investigating AD pathogenesis.
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Enfermedad de Alzheimer , Células Madre Pluripotentes Inducidas , Masculino , Humanos , Persona de Mediana Edad , Células Madre Pluripotentes Inducidas/metabolismo , Enfermedad de Alzheimer/patología , Leucocitos Mononucleares/metabolismo , Línea Celular , Diferenciación Celular , Proteínas Priónicas/metabolismoRESUMEN
Law enforcement is a stressful occupation that places significant psychological demands on those serving in this role. However, little is known about the severity of work-related stress and psychological distress among law enforcement officers (LEOs) in North Carolina (NC). This cross-sectional study examined the severity of work-related stress and psychological distress among 283 LEOs in NC. The Maslach Burnout Inventory, the Operational Police Stress Questionnaire, the Depression, Anxiety, and Stress Scale, and the Post-Traumatic Stress Disorder (PTSD) Checklist were used to assess burnout, operational police stress, depression, anxiety, stress, and PTSD among LEOs. Descriptive statistics, independent t-tests, Mann-Whitney U tests, one-way ANOVA, and Kruskal-Wallis tests were performed. Rural and male LEOs reported higher burnout levels related to depersonalization (i.e., increased mental distance from one's job) compared with their urban and female counterparts. LEOs exposed to toxic materials or performing patrol duties exhibited higher operational police stress levels than those who did not. Caucasian LEOs exhibited higher depression, anxiety, and stress than their African American counterparts. Rural LEOs and LEOs who were exposed to toxic materials displayed higher levels of PTSD than their counterparts. Our findings highlight the need for increased mental health support and better working environments for LEOs.
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Numerous innovative advancements in dressing technology for wound healing have emerged. Among the various types of wound dressings available, hydrogel dressings, structured with a three-dimensional network and composed of predominantly hydrophilic components, are widely used for wound care due to their remarkable capacity to absorb abundant wound exudate, maintain a moisture environment, provide soothing and cooling effects, and mimic the extracellular matrix. Composite hydrogel dressings, one of the evolved dressings, address the limitations of traditional hydrogel dressings by incorporating additional components, including particles, fibers, fabrics, or foams, within the hydrogels, effectively promoting wound treatment and healing. The added elements enhance the features or add specific functionalities of the dressings, such as sensitivity to external factors, adhesiveness, mechanical strength, control over the release of therapeutic agents, antioxidant and antimicrobial properties, and tissue regeneration behavior. They can be categorized as natural or synthetic based on the origin of the main components of the hydrogel network. This review focuses on recent research on developing natural polysaccharide-based composite hydrogel wound dressings. It explores their preparation and composition, the reinforcement materials integrated into hydrogels, and therapeutic agents. Furthermore, it discusses their features and the specific types of wounds where applied.
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Antiinfecciosos , Hidrogeles , Hidrogeles/farmacología , Cicatrización de Heridas , Vendas Hidrocoloidales , Polisacáridos/farmacologíaRESUMEN
BACKGROUND: Peripheral artery disease is an ischemic vascular disease caused by the blockage of blood vessels supplying blood to the lower extremities. Mesenchymal stem cells (MSCs) and endothelial colony-forming cells (ECFCs) have been reported to alleviate peripheral artery disease by forming new blood vessels. However, the clinical application of MSCs and ECFCs has been impeded by their poor in vivo engraftment after cell transplantation. To augment in vivo engraftment of transplanted MSCs and ECFCs, we investigated the effects of hybrid cell spheroids, which mimic a tissue-like environment, on the therapeutic efficacy and survival of transplanted cells. METHODS: The in vivo survival and angiogenic activities of the spheroids or cell suspension composed of MSCs and ECFCs were measured in a murine hindlimb ischemia model and Matrigel plug assay. In the hindlimb ischemia model, the hybrid spheroids showed enhanced therapeutic effects compared with the control groups, such as adherent cultured cells or spheroids containing either MSCs or ECFCs. RESULTS: Spheroids from MSCs, but not from ECFCs, exhibited prolonged in vivo survival compared with adherent cultured cells, whereas hybrid spheroids composed of MSCs and ECFCs substantially increased the survival of ECFCs. Moreover, single spheroids of either MSCs or ECFCs secreted greater levels of pro-angiogenic factors than adherent cultured cells, and the hybrid spheroids of MSCs and ECFCs promoted the secretion of several pro-angiogenic factors, such as angiopoietin-2 and platelet-derived growth factor. CONCLUSION: These results suggest that hybrid spheroids containing MSCs can serve as carriers for cell transplantation of ECFCs which have poor in vivo engraftment efficiency.
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Células Madre Mesenquimatosas , Enfermedad Arterial Periférica , Humanos , Animales , Ratones , Neovascularización Fisiológica , Células Endoteliales/metabolismo , Células Madre Mesenquimatosas/metabolismo , Células Cultivadas , Isquemia/terapia , Isquemia/metabolismoRESUMEN
The specific loss of midbrain dopamine neurons (mDANs) causes major motor dysfunction in Parkinson's disease, which makes cell replacement a promising therapeutic approach1-4. However, poor survival of grafted mDANs remains an obstacle to successful clinical outcomes5-8. Here we show that the surgical procedure itself (referred to here as 'needle trauma') triggers a profound host response that is characterized by acute neuroinflammation, robust infiltration of peripheral immune cells and brain cell death. When midbrain dopamine (mDA) cells derived from human induced pluripotent stem (iPS) cells were transplanted into the rodent striatum, less than 10% of implanted tyrosine hydroxylase (TH)+ mDANs survived at two weeks after transplantation. By contrast, TH- grafted cells mostly survived. Notably, transplantation of autologous regulatory T (Treg) cells greatly modified the response to needle trauma, suppressing acute neuroinflammation and immune cell infiltration. Furthermore, intra-striatal co-transplantation of Treg cells and human-iPS-cell-derived mDA cells significantly protected grafted mDANs from needle-trauma-associated death and improved therapeutic outcomes in rodent models of Parkinson's disease with 6-hydroxydopamine lesions. Co-transplantation with Treg cells also suppressed the undesirable proliferation of TH- grafted cells, resulting in more compact grafts with a higher proportion and higher absolute numbers of TH+ neurons. Together, these data emphasize the importance of the initial inflammatory response to surgical injury in the differential survival of cellular components of the graft, and suggest that co-transplanting autologous Treg cells effectively reduces the needle-trauma-induced death of mDANs, providing a potential strategy to achieve better clinical outcomes for cell therapy in Parkinson's disease.
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Tratamiento Basado en Trasplante de Células y Tejidos , Neuronas Dopaminérgicas , Supervivencia de Injerto , Enfermedades Neuroinflamatorias , Enfermedad de Parkinson , Linfocitos T Reguladores , Tirosina 3-Monooxigenasa , Humanos , Dopamina/análogos & derivados , Dopamina/metabolismo , Neuronas Dopaminérgicas/inmunología , Neuronas Dopaminérgicas/metabolismo , Neuronas Dopaminérgicas/trasplante , Mesencéfalo/patología , Enfermedades Neuroinflamatorias/etiología , Enfermedades Neuroinflamatorias/inmunología , Enfermedades Neuroinflamatorias/prevención & control , Enfermedades Neuroinflamatorias/terapia , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/patología , Enfermedad de Parkinson/cirugía , Enfermedad de Parkinson/terapia , Tirosina 3-Monooxigenasa/deficiencia , Tirosina 3-Monooxigenasa/metabolismo , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/trasplante , Tratamiento Basado en Trasplante de Células y Tejidos/métodos , Animales , Ratones , Ratas , Oxidopamina/metabolismo , Supervivencia de Injerto/inmunología , Muerte Celular , Células Madre Pluripotentes Inducidas/citología , Células Madre Pluripotentes Inducidas/inmunología , Células Madre Pluripotentes Inducidas/metabolismo , Células Madre Pluripotentes Inducidas/trasplante , Neostriado/metabolismo , Factores de Tiempo , Proliferación Celular , Resultado del TratamientoRESUMEN
Recombinant adeno-associated virus (rAAV)-based gene therapies offer an immense opportunity for rare diseases, such as amyotrophic lateral sclerosis (ALS), which is defined by the loss of the upper and the lower motor neurons. Here, we describe generation, characterization, and utilization of a novel vector system, which enables expression of the active form of hepatocyte growth factor (HGF) under EF-1α promoter with bovine growth hormone (bGH) poly(A) sequence and is effective with intrathecal injections. HGF's role in promoting motor neuron survival had been vastly reported. Therefore, we investigated whether intrathecal delivery of HGF would have an impact on one of the most common pathologies of ALS: the TDP-43 pathology. Increased astrogliosis, microgliosis and progressive upper motor neuron loss are important consequences of ALS in the motor cortex with TDP-43 pathology. We find that cortex can be modulated via intrathecal injection, and that expression of HGF reduces astrogliosis, microgliosis in the motor cortex, and help restore ongoing UMN degeneration. Our findings not only introduce a novel viral vector for the treatment of ALS, but also demonstrate modulation of motor cortex by intrathecal viral delivery, and that HGF treatment is effective in reducing astrogliosis and microgliosis in the motor cortex of ALS with TDP-43 pathology.
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Esclerosis Amiotrófica Lateral , Corteza Motora , Animales , Bovinos , Humanos , Esclerosis Amiotrófica Lateral/genética , Esclerosis Amiotrófica Lateral/terapia , Proteínas de Unión al ADN/genética , Gliosis , Factor de Crecimiento de Hepatocito/genética , Corteza Motora/patologíaRESUMEN
The hiPSC line was generated from peripheral blood mononuclear cells (PBMCs) collected from a female patient with young onset Parkinson's disease (PD), carrying on heterozygous c.1448 T > C (L483P), c1483 G > C (A495P) and c.1497 G > C (V499V) mutations in the GBA gene. The PBMCs was reprogrammed into an induced pluripotent stem cell (iPSC) line (GBA PD8 or PNUSCRi004-A hiPSCs) using non-integrative Sendai virus. The cell line, PNUSCRi004-A displayed a normal karyotype and expression of pluripotency markers capable of producing derivatives of three germ layers (Ectoderm, Endoderm and Mesoderm).
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Células Madre Pluripotentes Inducidas , Enfermedad de Parkinson , Humanos , Femenino , Células Madre Pluripotentes Inducidas/metabolismo , Reprogramación Celular , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/metabolismo , Leucocitos Mononucleares/metabolismo , Diferenciación Celular , Mutación/genéticaRESUMEN
The hiPSC line was generated from peripheral blood mononuclear cells (PBMCs) collected by a male patient with young onset Parkinson's disease, carrying on heterozygous c.680 A > G (N227S) mutation in the GBA gene. The PBMCs was reprogrammed into an induced pluripotent stem cell (iPSC) line (PNUSCRi001-A hiPSCs) using non-integrative sendai virus. The hiPSC line, PNUSCRi001-A displayed a normal karyotype and the Expression of pluripotency markers that is capable of producing derivatives of three germ layers (Ectoderm, Endoderm and Mesoderm).
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Células Madre Pluripotentes Inducidas , Enfermedad de Parkinson , Humanos , Masculino , Enfermedad de Parkinson/genética , Leucocitos Mononucleares , Mutación/genéticaRESUMEN
Aging in the peripheral nervous system (PNS) leads to its dysfunction and lowers regenerative capacity after injury. Based on the pro-regenerative effect of hepatocyte growth factor (HGF) in injured peripheral nerves, we investigated whether this growth factor is involved in the age-related degeneration of the PNS. We observed that the capacity for nerve regeneration was significantly reduced under aging conditions as indicated by the decreased level of SCG10-positive axons. Functional recovery was also impaired. We further tested whether the HGF/c-Met pathway was involved, and the activation of the c-Met receptor upon nerve injury was significantly reduced, whereas the production of HGF protein was still comparable to that in young mice. Moreover, the phosphorylation and expression of c-Jun, a key regeneration-associated gene, was also lowered in aged animals. In addition, exogenous administration of the HGF expressing plasmid DNA significantly ameliorated the pain-like behavior in young animals, however, such analgesic activity was impaired in aged mice. These data suggested that the HGF/c-Met pathway might be involved in the age-related impairment of regenerative capacity in the PNS.
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Mutation in the glucocerebrosidase encoding gene 1 (GBA) is one of the most frequent causes of Parkinson's disease (PD). Herein, we obtained peripheral blood mononuclear cells (PBMCs) from a patient with PD with a heterozygous c.475C > T (p.R159W) mutation in the GBA gene, and generated an induced pluripotent stem cell (iPSC) line (GBA PD9 or PNUSCRi002-A hiPSCs) using a non-integrative Sendai virus. The iPSC line expressed pluripotency markers (OCT4, NANOG, SSEA-4, TRA-1-60) and displayed differentiation properties in the three germ layers (ectoderm, endoderm, and mesoderm). Additionally, the patient had a normal karyotype.
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Glucosilceramidasa , Células Madre Pluripotentes Inducidas , Enfermedad de Parkinson , Humanos , Leucocitos Mononucleares , Mutación/genética , Enfermedad de Parkinson/genética , Línea Celular , Glucosilceramidasa/genéticaRESUMEN
Chronic neuropathic pain is caused by dysfunction of the peripheral nerves associated with the somatosensory system. Mesenchymal stem cells (MSCs) have attracted attention as promising cell therapeutics for chronic pain; however, their clinical application has been hampered by the poor in vivo survival and low therapeutic efficacy of transplanted cells. Increasing evidence suggests enhanced therapeutic efficacy of spheroids formed by three-dimensional culture of MSCs. In the present study, we established a neuropathic pain murine model by inducing a chronic constriction injury through ligation of the right sciatic nerve and measured the therapeutic effects and survival efficacy of spheroids. Monolayer-cultured and spheroids were transplanted into the gastrocnemius muscle close to the damaged sciatic nerve. Transplantation of spheroids alleviated chronic pain more potently and exhibited prolonged in vivo survival compared to monolayer-cultured cells. Moreover, spheroids significantly reduced macrophage infiltration into the injured tissues. Interestingly, the expression of mouse-origin genes associated with inflammatory responses, Ccl11/Eotaxin, interleukin 1A, tumor necrosis factor B, and tumor necrosis factor, was significantly attenuated by the administration of spheroids compared to that of monolayer. These results suggest that MSC spheroids exhibit enhanced in vivo survival after cell transplantation and reduced the host inflammatory response through the regulation of main chronic inflammatory response-related genes.
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Dolor Crónico , Células Madre Mesenquimatosas , Neuralgia , Animales , Dolor Crónico/metabolismo , Inflamación/genética , Inflamación/metabolismo , Células Madre Mesenquimatosas/metabolismo , Ratones , Neuralgia/metabolismo , Neuralgia/terapia , Esferoides Celulares/metabolismo , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Hepatocyte growth factor (HGF) is a multifunctional protein that plays a critical role in the angiogenic, neurotrophic, antifibrotic, and antiapoptotic activities of various cell types. It has been previously reported that intramuscular injection of pCK-HGF-X7 (or VM202), a plasmid DNA designed to express both native isoforms of human HGF (Pyun et al., 2010), significantly reduced the level of neuropathic pain in clinical studies as well as in a variety of animal models. In clinical studies, it has been observed that pCK-HGF-X7 appeared to give much higher pain-relieving effects in subjects not taking pregabalin or gabapentin, α2δ1 calcium channel blockers frequently prescribed for reducing pain in patients with diabetic peripheral neuropathy. In this study, we tested the effects of gabapentin on HGF-mediated pain reduction and nerve regeneration in vivo. Consistent with the data from clinical studies, gabapentin administration inhibited the pain reduction and axon regeneration effects mediated by HGF expression from pCK-HGF-X7. In the context of nerve regenerative effects, treatment with gabapentin or EGTA, a Ca2+ chelator, inhibited HGF-mediated axon outgrowth of injured sciatic nerves in vivo. Taken together, i.m. injection of HGF-encoding plasmid DNA ameliorated pain symptoms and enhanced the regeneration of injured nerves, and these therapeutic effects of HGF were significantly hindered by gabapentin treatment, suggesting the possible involvement of Ca2+ in the pro-regenerative activities of native HGF derived from treatment with pCK-HGF-X7.
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Neuralgia , Traumatismos de los Nervios Periféricos , Analgésicos/farmacología , Analgésicos/uso terapéutico , Animales , Axones/metabolismo , ADN/genética , ADN/farmacología , Modelos Animales de Enfermedad , Gabapentina/farmacología , Gabapentina/uso terapéutico , Terapia Genética , Factor de Crecimiento de Hepatocito/genética , Factor de Crecimiento de Hepatocito/farmacología , Factor de Crecimiento de Hepatocito/uso terapéutico , Humanos , Regeneración Nerviosa , Neuralgia/tratamiento farmacológico , Traumatismos de los Nervios Periféricos/tratamiento farmacológicoRESUMEN
Inspired by natural materials, we developed an antibacterial surface on titanium (Ti) using hydrothermal etching techniques and examined the effect of treated time on oxide layer formation, its antibacterial properties, and surface defects. Hydrothermal etching was conducted on Grade 2 commercially pure Ti immersed in 5M NaOH at 250 °C during a range of time of 0-12 h. Nanopillars generated on the surface had ~100 nm thickness, which resulted in decreased attachment and rupturing of the attached bacteria. The results also showed that 6 h and 8 h of etching time provided a desirable uniform nanopillar structure with the most effective prevention of bacterial adherence on the surface. Multiscale SEM observations revealed that the longer the etching was conducted, the more cracks propagated, which led to an increase in dissociated fragments of the oxide layer. In the 12 h of etching, a higher density of bacterial adherence was observed than that of the untreated and the shorter time treated samples, indicating that etching took longer than 10 h worsened the antibacterial properties of the nano-patterned surface of Ti. This study demonstrated that the optimal time duration is 6-8 h for the oxide layer formation to maximize antibacterial activity and minimize cracking formation on the surface. For future studies, we suggest exploring many possible conditions to generate a more uniform nanopattern without structural defects to secure the integration between a newly deposited oxide layer and the substrate.
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Insulin-like growth factor-1 (IGF-1) plays a significant role in the development of various organs, and several studies have suggested that IGF-1 isoforms, IGF-1 Ea and IGF-1 Ec, are expressed in skeletal muscle to control its growth. In this study, we designed a novel nucleotide sequence, IGF-1-X10, consisting of IGF-1 exons and introns to simultaneously express both IGF-1 Ea and IGF-1 Ec. When transfected into human cells, the expression of both isoforms was observed at the transcript and protein levels. In an animal study, intramuscular injection of plasmid DNA comprising IGF-1-X10 induced the expression of IGF-1 Ea and IGF-1 Ec, leading to the production of functional IGF-1 protein. Finally, the efficacy of this plasmid DNA was tested in a cardiotoxin (CTX)-mediated muscle injury model and age-related muscle atrophy model. We found that IGF-1-X10 increased the muscle mass and controlled several key factors involved in the muscle atrophy program in both models. Taken together, these data suggest that IGF-1-X10 may be utilized in the form of gene therapy for the treatment of various muscle diseases related to IGF-1 deficiency.
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Factor I del Crecimiento Similar a la Insulina , Enfermedades Musculares , Animales , Humanos , Factor I del Crecimiento Similar a la Insulina/genética , Factor I del Crecimiento Similar a la Insulina/metabolismo , Músculo Esquelético/metabolismo , Atrofia Muscular , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Plásmidos/genética , Enfermedades Musculares/metabolismo , ADNRESUMEN
To fully realize the potential of human pluripotent stem cells (hPSCs) for both therapeutic and research purposes, it is critical to follow an efficient and reliable in vitro differentiation method that is based on optimal physical, chemical and developmental cues. This highly reproducible protocol describes how to grow hPSCs such as human induced pluripotent and embryonic stem cells in a physically confined area ('spot') and efficiently differentiate them into a highly enriched population of healthy and functional midbrain dopamine progenitors (mDAPs) and midbrain dopamine neurons (mDANs). The protocol takes 28 d, during which cells first grow and differentiate in spots for 14 d and then are replated and further differentiated for a further 14 d as a monolayer culture. We describe how to produce mDAPs, control the quality of cells and cryopreserve mDAPs without loss of viability. Previously we showed that mDANs generated by this 'spotting'-based method exhibit gene expression and (electro)physiological properties typical of A9 mDANs lost in Parkinson's disease brains and can rescue motor defects when transplanted into the striatum of 6-hydroxydopamine-lesioned rats. This protocol is scalable for production of mDAPs under good manufacturing practice conditions and was also previously successfully used to generate cells for the first autologous cell replacement therapy of a patient with Parkinson's disease without the need for immune suppression. We anticipate this protocol could also be readily adapted to use spotting-based culture to further optimize the differentiation of hPSC to alternative differentiated cell types.
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Células Madre Pluripotentes Inducidas , Células Madre Pluripotentes , Animales , Diferenciación Celular , Dopamina/metabolismo , Neuronas Dopaminérgicas , Humanos , Mesencéfalo , RatasRESUMEN
Bifidobacterium bifidum BGN4 has been shown to improve the immune system by regulating interleukin (IL)-6 in RAW 264.7 macrophage cells. In this study, the dead cells of B. bifidum BGN4 were produced by enzymatic and physical processing to enhance the inhibition properties of pro-inflammatory cytokines using lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Notably, the secretion levels of cytokines such as interleukin (IL)-1ß, IL-6, IL-8, and tumor necrosis factor (TNF)-α were decreased by the cell-wall disrupted extracts compared to heat-killed cells. The result suggests that the exposed interior-surface of B. bifidum BGN4 has a potential ability to regulate the immune-responses in the gastrointestinal tract due to major substances in inside-cell wall such as peptidoglycan and teichoic acids. In conclusion, the lysed and disrupted cells from the inside out of B. bifidum BGN4 have anti-inflammatory properties as paraprobiotic agents to control chronic inflammatory related-diseases.
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The most common type of spinal cord injury is the contusion of the spinal cord, which causes progressive secondary tissue degeneration. In this study, we applied genetically modified human neural stem cells overexpressing BDNF (brain-derived neurotrophic factor) (F3.BDNF) to determine whether they can promote functional recovery in the spinal cord injury (SCI) model in rats. We transplanted F3.BDNF cells via intrathecal catheter delivery after a contusion of the thoracic spinal cord and found that they were migrated toward the injured spinal cord area by MR imaging. Transplanted F3.BDNF cells expressed neural lineage markers, such as NeuN, MBP, and GFAP and were functionally connected to the host neurons. The F3.BDNF-transplanted rats exhibited significantly improved locomotor functions compared with the sham group. This functional recovery was accompanied by an increased volume of spared myelination and decreased area of cystic cavity in the F3.BDNF group. We also observed that the F3.BDNF-transplanted rats showed reduced numbers of Iba1- and iNOS-positive inflammatory cells as well as GFAP-positive astrocytes. These results strongly suggest the transplantation of F3.BDNF cells can modulate inflammatory cells and glia activation and also improve the hyperalgesia following SCI.
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Factor Neurotrófico Derivado del Encéfalo/metabolismo , Células-Madre Neurales/metabolismo , Animales , Electrofisiología , Humanos , Inmunohistoquímica , Ratas Sprague-Dawley , Recuperación de la Función/fisiología , Traumatismos de la Médula Espinal/metabolismoRESUMEN
Hepatocyte growth factor (HGF) is a neurotrophic factor and its role in peripheral nerves has been relatively unknown. In this study, biological functions of HGF and its receptor c-met have been investigated in the context of regeneration of damaged peripheral nerves. Axotomy of the peripheral branch of sensory neurons from embryonic dorsal root ganglia (DRG) resulted in the increased protein levels of HGF and phosphorylated c-met. When the neuronal cultures were treated with a pharmacological inhibitor of c-met, PHA665752, the length of axotomy-induced outgrowth of neurite was significantly reduced. On the other hand, the addition of recombinant HGF proteins to the neuronal culture facilitated axon outgrowth. In the nerve crush mouse model, the protein level of HGF was increased around the injury site by almost 5.5-fold at 24 h post injury compared to control mice and was maintained at elevated levels for another 6 days. The amount of phosphorylated c-met receptor in sciatic nerve was also observed to be higher than control mice. When PHA665752 was locally applied to the injury site of sciatic nerve, axon outgrowth and injury mediated induction of cJun protein were effectively inhibited, indicating the functional involvement of HGF/c-met pathway in the nerve regeneration process. When extra HGF was exogenously provided by intramuscular injection of plasmid DNA expressing HGF, axon outgrowth from damaged sciatic nerve and cJun expression level were enhanced. Taken together, these results suggested that HGF/c-met pathway plays important roles in axon outgrowth by directly interacting with sensory neurons and thus HGF might be a useful tool for developing therapeutics for peripheral neuropathy.
RESUMEN
Hepatocyte growth factor (HGF) promotes the neurite outgrowth of sensory neurons in developmental stages, but its role in injured peripheral nerves in adult mice remains largely been unexplored. In this study, we investigated the role of HGF in the regeneration of injured peripheral nerves using cultured dorsal root ganglions (DRGs). When cells were treated with HGF protein, the length of the neurite was increased 1.4-fold compared to the untreated control group. HGF greatly increased the level of phosphorylated STAT3 at serine 727 [pSTAT3 (Ser 727)], thereby translocating the protein to the mitochondria. HGF treatment increased the activity of mitochondrial complex I. When DRGs were cultured in the presence of U0126, a pharmacological inhibitor of Erk, the HGF-mediated increase in neurite outgrowth and the level of pSTAT3 (Ser 727) were both suppressed. Taken together, these results suggest that the HGF/c-met pathway might promote neurite outgrowth by controlling mitochondrial activity through the HGF/Erk/STAT3 axis.
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Axones/efectos de los fármacos , Quinasas MAP Reguladas por Señal Extracelular/efectos de los fármacos , Factor de Crecimiento de Hepatocito/farmacología , Mitocondrias/efectos de los fármacos , Regeneración Nerviosa/efectos de los fármacos , Proyección Neuronal/efectos de los fármacos , Factor de Transcripción STAT3/efectos de los fármacos , Células Receptoras Sensoriales/efectos de los fármacos , Animales , Axones/metabolismo , Butadienos/farmacología , Complejo I de Transporte de Electrón/efectos de los fármacos , Complejo I de Transporte de Electrón/metabolismo , Inhibidores Enzimáticos/farmacología , Quinasas MAP Reguladas por Señal Extracelular/antagonistas & inhibidores , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Ganglios Espinales/citología , Ratones , Mitocondrias/metabolismo , Nitrilos/farmacología , Traumatismos de los Nervios Periféricos/metabolismo , Fosforilación , Cultivo Primario de Células , Transporte de Proteínas , Proteínas Tirosina Quinasas Receptoras/metabolismo , Factor de Transcripción STAT3/metabolismo , Células Receptoras Sensoriales/metabolismoRESUMEN
This study examined natural composite structures within the remarkably strong exoskeleton of the southwestern ironclad beetle (Z. haldemani). Structural and nanomechanical analyses revealed that the exoskeleton's extraordinary resistance to external forces is provided by its exceptional thickness and multi-layered structure, in which each layer performed a distinct function. In detail, the epicuticle, the outmost layer, comprised 3%-5% of the overall thickness with reduced Young's moduli of 2.2-3.2 GPa, in which polygonal-shaped walls (2-3µm in diameter) were observed on the surface. The next layer, the exocuticle, consisted of 17%-20% of the total thickness and exhibited the greatest Young's moduli (â¼15 GPa) and hardness (â¼800 MPa) values. As such, this layer provided the bulk of the mechanical strength for the exoskeleton. While the endocuticle spanned 70%-75% of the total thickness, it contained lower moduli (â¼8-10 GPa) and hardness (â¼400 MPa) values than the exocuticle. Instead, this layer may provide flexibility through its specifically organized chitin fiber layers, known as Bouligand structures. Nanoindentation testing further reiterated that the various fibrous layer orientations resulted in different elastic moduli throughout the endocuticle's cross-section. Additionally, this exoskeleton prevented delamination within the composite materials by overlapping approximately 5%-19% of each fibrous stack with neighboring layers. Finally, the innermost layer, the epidermis contributing 5%-7 % of the total thickness, contains attachment sites for muscle and soft tissue that connect the exoskeleton to the beetle. As such, it is the softest region with reduced Young's modulus of â¼2-3 GPa and hardness values of â¼290 MPa. These findings can be applied to the development of innovative, fiber-reinforced composite materials.