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Glaucoma is one of the leading causes of vision loss worldwide. More and more studies have suggested that glaucoma is a complicated retinal neurovascular disease. The homeostasis imbalance of retinal neurovascular unit(RNVU)composed of neurons, glial cells and microvascular cells not only induces changes in microvascular structure and glial cells, but also affects the nerve tissue of the retina, resulting in vision loss, which there is no effective treatment to reverse, currently. Exploring the cellular composition and molecular structure of RNVU and investigating the destruction mechanism of normal cellular environment and intercellular connections in glaucoma are of great significance in exploring the pathogenesis and the treatment of glaucoma. The research progress on structural changes and dysfunction of RNVU in glaucoma are reviewed, hoping to provide new ideas for the treatment of glaucoma.
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Heterozygous loss-of-function variants of FOXP4 are associated with neurodevelopmental disorders (NDDs) that exhibit delayed speech development, intellectual disability, and congenital abnormalities. The etiology of NDDs is unclear. Here we found that FOXP4 and N-cadherin are expressed in the nuclei and apical end-feet of radial glial cells (RGCs), respectively, in the mouse neocortex during early gestation. Knockdown or dominant-negative inhibition of Foxp4 abolishes the apical condensation of N-cadherin in RGCs and the integrity of neuroepithelium in the ventricular zone (VZ). Inhibition of Foxp4 leads to impeded radial migration of cortical neurons and ectopic neurogenesis from the proliferating VZ. The ectopic differentiation and deficient migration disappear when N-cadherin is over-expressed in RGCs. The data indicate that Foxp4 is essential for N-cadherin-based adherens junctions, the loss of which leads to periventricular heterotopias. We hypothesize that FOXP4 variant-associated NDDs may be caused by disruption of the adherens junctions and malformation of the cerebral cortex.
Subject(s)
Mice , Animals , Ependymoglial Cells/physiology , Cadherins , Neurons/metabolism , Cerebral Cortex/metabolism , Cell Differentiation , Cell MovementABSTRACT
ObjectiveTo investigate the effects of Mingjing granules （MJKL） on the fibrovascular membrane of experimental wet age-related macular degeneration （nAMD） based on macrophages and glial cells and further explain the mechanism of MJKL in the treatment of nAMD. MethodThe experimental nAMD fibrovascular membrane model was established by two-stage laser photocoagulation. BN rats were randomly divided into three groups： model group， anti-vascular endothelial growth factor （VEGF） group， and MJKL + anti-VEGF group. The model group was given distilled water for intragastric administration. Anti-VEGF group was injected with leizumab injection in the vitreous cavity. MJKL + anti-VEGF group was injected with leizumab injection in the vitreous cavity， and MJKL was intragastrically administered. Ten normal BN rats were not modeled and fed as controls. After 40 days of model making， fundus lesion morphology， lesion exudation area， and MD value were observed by fundus photography （FP）， fundus angiography （FFA）， optical coherence tomography （OCT）， and retinal pigment epithelium （RPE）-choroid-sclera film. The changes in retinal structure were observed by histopathology， and the expression and distribution of F4/80， Iba-1， and GFAP were detected by immunofluorescence. The relative expression levels of F4/80， Iba-1， and GFAP mRNA were detected by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. ResultThe fibrovascular membrane model was established 40d after two-stage laser modeling. The lesion exudation area， MD value， lesion height， and lesion area in the anti-VEGF group were significantly lower than those in the model group （P<0.05）， and the retinal structural damage degree was significantly improved. Compared with the anti-VEGF group， the MJKL + anti-VEGF group significantly decreased the MD value， lesion height， and lesion area （P<0.05）， and lesion area and retinal structural damage degree were significantly improved. The fluorescence intensity of F4/80 and Iba-1 in the model group was significantly higher than that in the normal group （P<0.05）， and that in the anti-VEGF group was significantly lower than that in the model group （P<0.05）. The fluorescence intensity in the MJKL + anti-VEGF group was significantly lower than that in the anti-VEGF group （P<0.05）. The fluorescence intensity of GFAP in the model group was significantly higher than that in the normal group （P<0.05）， and that in the anti-VEGF group was significantly lower than that in the model group （P<0.05）. The relative expression levels of F4/80， Iba-1， and GFAP mRNA in the model group were significantly increased compared with the normal group （P<0.05）， and the anti-VEGF group was significantly decreased compared with the model group （P<0.05）. The relative expression levels of F4/80， Iba-1， and GFAP mRNA in the MJKL + anti-VEGF group were significantly decreased compared with those in the anti-VEGF group （P<0.05）. ConclusionMJKL combined with anti-VEGF drugs can inhibit the growth of experimental nAMD fibrovascular membrane better than anti-VEGF drugs alone， and the mechanism may be related to inhibiting the participation of macrophages and glial cells in the formation of fibrovascular membrane.
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@#Introduction: Astrocytes are responsible for many essential functions of neurons in CNS. It has been recognised that chronic stress affects the morphology of astrocyte. Natural antioxidant such as honey has been used as one of the therapeutic strategies to lessen the damaging effect of chronic stress on our body. Therefore, the aim of the study is to explore the effect of natural antioxidant, Tualang honey (TH) on the morphology of astrocytes following chronic stress exposure. Methods: Thirty-two male rats were randomly divided into the 4 groups: (i) control, (ii) stress, (iii) honey, (iv) stress plus honey groups.TH was administered via oral gavage at dose of 1.0 g/kg body weight pre and post experiment. Chronic stress was exposed to animals in group (ii) and (iv) for consecutive 21 days. Anti GFAP immunohistochemistry method was employed to label astrocytes in the medial prefrontal cortex. The number of GFAP+ astrocytes and several parameters related to astrocyte processes were measured. Results: The present study showed that chronic stress reduced the GFAP immunoreactive astrocyte number and percentage of GFAP immunoreactive material. Chronic stress also caused a reduction in astrocyte process ramification as indicated by a reduction in astrocyte total number of processes, average length of processes and maximum number of intersections. However, antioxidant treatment using TH could not reverse these stress-induced changes to the astrocytes. Conclusion: These results demonstrate that chronic stress decreases the number of GFAP immunoreactive astrocyte and cause shrinking of astrocyte processes in stress-sensitive brain region, but these changes cannot be reversed by antioxidant treatment.
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The majority of primary hyperparathyroidism (PHPT) are sporadic, and less than 10% of cases are hereditary or part of familial syndromes. Glial cell missing 2 (GCM2) was confirmed to be a new pathogenic gene of PHPT in 2016. At present, four GCM2 mutations have been confirmed to have certain correlations with familial or sporadic PHPT. The purpose of this review is to summarize the pathogenesis and clinical features of GCM2 mutation related primary hyperparathyroidism.
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Human cortical radial glial cells are primary neural stem cells that give rise to cortical glutaminergic projection pyramidal neurons, glial cells (oligodendrocytes and astrocytes) and olfactory bulb GABAergic interneurons. One of prominent features of the human cortex is enriched with glial cells, but there are major gaps in understanding how these glial cells are generated. Herein, by integrating analysis of published human cortical single-cell RNA-Seq datasets with our immunohistochemistical analyses, we show that around gestational week 18, EGFR-expressing human cortical truncated radial glial cells (tRGs) give rise to basal multipotent intermediate progenitors (bMIPCs) that express EGFR, ASCL1, OLIG2 and OLIG1. These bMIPCs undergo several rounds of mitosis and generate cortical oligodendrocytes, astrocytes and olfactory bulb interneurons. We also characterized molecular features of the cortical tRG. Integration of our findings suggests a general picture of the lineage progression of cortical radial glial cells, a fundamental process of the developing human cerebral cortex.
Subject(s)
Humans , Astrocytes , Cell Differentiation , Cerebral Cortex , Neuroglia , OligodendrogliaABSTRACT
Objective:To investigate the effects of Bifidobacterium animalis subsp. lactis BB-12 on hippocampal neuroinflammation and cognitive function of mice after whole brain radiotherapy. Methods:A total of sixty male C57BL/6J mice aged 7-8 weeks were randomly divided into 5 groups with 12 mice in each group: control group (Con group), probiotic group (BB-12 group), irradiation group (IR group), irradiation and Memantine group (IR+ Memantine group), irradiation and probiotic group (IR+ BB-12 group). The model of radiation-induced brain injury of mice was established by 10 Gy whole brain radiotherapy with a medical linear accelerator. Y-maze test was used to evaluate the cognitive function. The activation of microglia and astrocytes was observed by immunofluorescence staining. The expressions of inflammatory cytokines interleukin-1β (IL-1β), IL-6 and tumor necrosis factor-α (TNF-α) were detected by quantitative real-time reverse transcription polymerase chain reaction (QRT-PCR) and Western blot.Results:Y-maze test showed that, compared with Con group, the percentage of the times of reaching the novel arm in the total times of the three arms decreased significantly in the IR group ( t=5.04, P<0.05). BB-12 mitigated radiation-induced cognitive dysfunction ( t=4.72, P<0.05). Compared with Con group, the number ( t=3.05, 7.18, P<0.05) and circularity index ( t=6.23, 2.52, P<0.05) of Iba1 and GFAP positive cells were increased, the microglia and astrocytes were activated in the hippocampus of IR group, but these alterations were eliminated by BB-12. After whole brain IR, the mRNA and protein expression levels of inflammatory cytokines IL-1β, IL-6 and TNF-α in the hippocampus of mice were significantly increased compared with Con group ( tmRNA =4.10, 3.04, 4.18, P<0.05; tprotein=11.49, 7.04, 8.42, P<0.05), which were also significantly reduced by BB-12 compared with IR group ( tmRNA=4.20, 3.40, 2.84, P<0.05; tprotein=6.36, 4.03, 3.75, P<0.05). Conclusions:Bifidobacterium animalis BB-12 can suppress neuroinflammation mediated by microglia and astrocytes in the hippocampus of mice after radiotherapy and alleviates IR-induced cognitive dysfunction. Therefore, BB-12 has potential application in alleviating radiation induced brain injury.
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Objective:To explore the perivascular activation of reactive pericytes after status epilepticus(SE), and the relationship between pericytes and glial cells in proliferation and function.Methods:Eighty rats were randomly divided into control group( n=16) and model group( n=64, 16 for each group in SE1d, SE3d, SE7d, SE28d). The SE model was induced by intraperitoneal injection of lithium chloride and pilocarpine, and hematoxylin-eosin staining was performed on brain tissue sections to observe basic pathological changes.Use immunohistochemistry and Western blot to detect(neuron-glial antigen 2, NG2) expression, and use immunofluorescence technology to double stain NG2 and(glial fibrillary acidic protein, GFAP) to observe their relationship. Results:In the model group, the neurons were arranged disorderly, losing the ribbon structure, and the neurons appeared degeneration and necrosis.It was observed that the nuclei of the neurons were blurred, and the cytoplasm was agglomerated.There were more glial cells proliferation.Compared with the control group, it was found in model group that NG2 showed a dynamic high expression after SE( P<0.05). The number of pericytes increased significantly, reaching a peak at 7d, and the results of Western blot were consistent with the results of histochemistry( P<0.05). The aggregation of glial cells were induced in the surrounding area, and pericytes participated in the signal transduction of glial cells. Conclusion:Pericytes can induce the aggregation of glial cells and participate in the repairment in the form of glial scars after SE brain injury.
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ObjectiveTo investigate whether Xiayuxue decoction exerts an anti-liver fibrosis effect by inhibiting glial cell line-derived neurotrophic factor (GDNF). MethodsA total of 24 C57BL/6 mice were randomly divided into control group, model group, and Xiayuxue decoction group. The mice in the model group and the Xiayuxue decoction group were given intraperitoneal injection of 10% CCl4, and those in the Xiayuxue decoction group were given 0.4678 g/kg Xiayuxue decoction by gavage since week 4. The liver function parameters alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured, and liver histopathology was observed. Immunohistochemistry was used to measure the protein expression of alpha-smooth muscle actin (α-SMA) and GDNF. GFP-Col-HSC and human primary hepatic stellate cells (HSCs) were treated with GDNF (10 ng/ml), and HSC activation was measured. A one-way analysis of variance was used for comparison of continuous data between multiple groups, and the least significant difference t-test was used for further comparison between two groups. ResultsCompared with the control group, the model group had significant increases in the levels of ALT and AST, and compared with the model group, the Xiayuxue decoction group had significant reductions in the levels of ALT and AST (all P＜0.01). Liver histopathology showed that the model group had marked inflammatory cell infiltration and formation of fibrous septa by proliferated collagen fibers, and the Xiayuxue decoction group had loose fibrous septa and alleviated inflammatory cell infiltration. Immunohistochemistry showed that compared with the control group, the model group had significant increases in the expression of α-SMA and GDNF (both P＜0.01), which were observed in fibrous septa, and compared with the model group, the Xiayuxue decoction group had significant reductions in the expression of α-SMA and GDNF (both P＜0.05). Western blotting showed that the control group had relatively low expression of GDNF in liver tissue, the formation of liver fibrosis at week 6 of CCl4 modeling, and an around 10-fold increase in the expression of GDNF, and the Xiayuxue decoction group had significantly inhibited protein expression of GDNF (P＜0.01); there were significant increases in the expression of α-SMA and collagen type I α1 (Col1) in mice with liver fibrosis, with significant reductions in α-SMA and Col1 after treatment with Xiayuxue decoction (all P＜0.01). The in vitro experiment showed that GDNF induced the significant increases in the protein expression of α-SMA and Col1 in HSCs, which was significantly inhibited by Xiayuxue decoction (all P＜0.01). ConclusionThe expression of GDNF is significantly upregulated in the formation of liver fibrosis. GDNF can induce HSC activation, and Xiayuxue decoction can exert an anti-liver fibrosis effect by inhibiting GDNF.
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The capacity for neurogenesis in the adult mammalian brain is extremely limited and highly restricted to a few regions, which greatly hampers neuronal regeneration and functional restoration after neuronal loss caused by injury or disease. Meanwhile, transplantation of exogenous neuronal stem cells into the brain encounters several serious issues including immune rejection and the risk of tumorigenesis. Recent discoveries of direct reprogramming of endogenous glial cells into functional neurons have provided new opportunities for adult neuro-regeneration. Here, we extensively review the experimental findings of the direct conversion of glial cells to neurons in vitro and in vivo and discuss the remaining issues and challenges related to the glial subtypes and the specificity and efficiency of direct cell-reprograming, as well as the influence of the microenvironment. Although in situ glial cell reprogramming offers great potential for neuronal repair in the injured or diseased brain, it still needs a large amount of research to pave the way to therapeutic application.
Subject(s)
Animals , Cellular Reprogramming , Nerve Regeneration , Neurogenesis , Neuroglia , NeuronsABSTRACT
Mouse cortical radial glial cells (RGCs) are primary neural stem cells that give rise to cortical oligodendrocytes, astrocytes, and olfactory bulb (OB) GABAergic interneurons in late embryogenesis. There are fundamental gaps in understanding how these diverse cell subtypes are generated. Here, by combining single-cell RNA-Seq with intersectional lineage analyses, we show that beginning at around E16.5, neocortical RGCs start to generate ASCL1
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The capacity for neurogenesis in the adult mammalian brain is extremely limited and highly restricted to a few regions, which greatly hampers neuronal regeneration and functional restoration after neuronal loss caused by injury or disease. Meanwhile, transplantation of exogenous neuronal stem cells into the brain encounters several serious issues including immune rejection and the risk of tumorigenesis. Recent discoveries of direct reprogramming of endogenous glial cells into functional neurons have provided new opportunities for adult neuro-regeneration. Here, we extensively review the experimental findings of the direct conversion of glial cells to neurons in vitro and in vivo and discuss the remaining issues and challenges related to the glial subtypes and the specificity and efficiency of direct cell-reprograming, as well as the influence of the microenvironment. Although in situ glial cell reprogramming offers great potential for neuronal repair in the injured or diseased brain, it still needs a large amount of research to pave the way to therapeutic application.
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When ischemia or hemorrhagic stroke occurs, astrocytes are activated by a variety of endogenous regulatory factors to become reactive astrocytes. Subsequently, reactive astrocytes proliferate, differentiate, and migrate around the lesion to form glial scar with the participation of microglia, neuron-glial antigen 2(NG2) glial cells, and extracellular matrix. The role of glial scars at different stages of stroke injury is different. At the middle and late stages of the injury, the secreted chondroitin sulfate proteoglycan and chondroitin sulfate are the main blockers of axon regeneration and nerve function recovery. Targeted regulation of glial scars is an important pathway for neurological rehabilitation after stroke. Chinese medicine has been verified to be effective in stroke rehabilitation in clinical practice, possibly because it has the functions of promoting blood resupply, anti-inflammation, anti-oxidative stress, inhibiting cell proliferation and differentiation, and benign intervention in glial scars. This study reviewed the pathological process and signaling mechanisms of glial scarring after stroke, as well as the intervention of traditional Chinese medicine upon glial scar, aiming to provide theoretical reference and research evidence for developing Chinese medicine against stroke in view of targeting glial scarring.
Subject(s)
Humans , Astrocytes , Axons/pathology , Cicatrix/pathology , Gliosis/pathology , Medicine, Chinese Traditional , Nerve Regeneration , Stroke/drug therapyABSTRACT
BACKGROUND: The mechanism of electroacupuncture on multi-acupoints in the treatment of peripheral facial paralysis is still unknown. Glial cell-derived neurotrophic factor (GDNF) is currently the most effective factor in promoting the survival of motoneurons in vitro, and the PI3K/AKT pathway plays an important role in protecting damaged motoneurons. There is yet no research on GDNF/PI3K/AKT pathway involved in electroacupuncture promoting facial nerve regeneration in rabbits. OBJECTIVE: To observe the effect of electroacupuncture on regeneration after peripheral facial nerve crush injury, and to explore the protective mechanism of electroacupuncture on facial motoneurons through the GDNF/PI3K/AKT signaling pathway. METHODS: Sixty-six adult healthy New Zealand white rabbits provided by the Animal Experimental Center of Southwest Medical University were randomly divided into a normal group and a model group. The facial nerves on the right side in the model group were subjected to a crush injury. Then the animal models were randomly divided into a model control group and an electroacupuncture group. Animals in the model control group recovered naturally, while those in the electroacupuncture group underwent electroacupuncture at Yifeng, Jiache, Sibai, Dicang, Yangbai, and Quanliao acupoints daily for 30 minutes. The improvement of facial paralysis symptoms in experimental animals were observed and scored. Tissue samples were directly taken form the normal group, and pons tissues with facial neurons were taken in the model group at 1, 4, 7, 14, and 28 days postoperatively. The morphologies of facial motoneurons and Nissl bodies were observed by hematoxylin-eosin staining and Nissl staining, respectively. Immunohistochemical techniques and western blot assay were used to detect the protein expression of GDNF, PI3K, AKT, and p-AKT in the facial motoneurons. The study protocol was approved by the Animal Ethics Committee of Southwest Medical University with approval No. 20170120001. RESULTS AND CONCLUSION: The symptoms of facial paralysis were that the animal’s mouth was drooped at the affected side, with lodging tentacles and the movement being weakened, and the eyelids that could not be lifted, which recovered faster and more completely in the electroacupuncture group than the model control group. The morphological changes of facial neurons and changes of Nissl bodies in the electroacupuncture group were lighter than those in the model control group. At each time point postoperatively, the stronger GDNF immune response could be seen in the electroacupuncture group, and the number of GDNF-positive cells was higher than that of the model control group except 1 day postoperatively (P < 0.001). The expressions of GDNF, PI3K, p-AKT proteins in the facial motoneurons were significantly increased in the electroacupuncture group compared with the model control group (P < 0.05; P < 0.01; P < 0.001). To conclude, electroacupuncture can effectively treat the peripheral facial paralysis caused by the crushed injury of facial nerve and promote the recovery of facial neurons. The up-regulation of GDNF expression in the facial motoneurons and the activation of PI3K/AKT signaling pathway may be the underlying protective mechanism of electroacupuncture.
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BACKGROUND: Glial cell line derived neurotrophic factor (GDNF) plays an important role in inducing differentiation of bone marrow mesenchymal stem cells (BMSCs) in vitro and promoting neurological function recovery in rats with spinal cord injury. OBJECTIVE: To observe potential molecular mechanisms of differentiation of BMSCs overexpressing GDNF gene and promoting neurological function recovery after spinal cord injury in rats. METHODS: (1) BMSCs transfected with recombinant target gene adenovirus were divided into Ad-GDNF-GFP transfection group, Ad-GFP transfection group and non-transfection group. Microtubule-associated protein 2 and neuron-specific enolase expression levels were detected by immunofluorescence in each group. Western blot assay was used to detect the expression of GDNF, Wnt3a and Wnt7a protein in each group. (2) The rat spinal cord injury model was prepared by modified Allen method. The 45 Sprague-Dawley rat models were randomly divided into three groups. GDNF-BMSCs, BMSCs and PBS were transplanted into the site of spinal cord injury. The motor function recovery of rats was evaluated 4 weeks after operation. The morphological changes of spinal cord were observed by hematoxylin-eosin staining. The local neuron-specific enolase, Synapsin I and glial fibrillary acidic protein were analyzed with immunohistochemistry. The expression levels of Bcl-2 and tumor necrosis factor-α protein were detected by western blot assay. RESULTS AND CONCLUSION: (1) BMSCs overexpressing GDNF gene could differentiate into neuron-like cells and express neuron-specific enolase and microtubule-associated protein 2 in vitro in the Ad-GDNF-GFP transfection group. The expression of Wnt3a and Wnt7a protein was significantly higher in the Ad-GDNF-GFP transfection group than in the Ad-GFP transfection group and non-transfection group. (2) The Basso, Beattie and Bresnahan score in GDNF-BMSCs group was significantly increased and the stenosis area was significantly reduced at 4 weeks after transplantation. The expression of glial fibrillary acidic protein and tumor necrosis factor-α in GDNF-BMSCs group was significantly lower than that in BMSCs and PBS transplantation groups, but the expression levels of neuron-specific enolase, Synapsin I and Bcl-2 were significantly higher than those in the BMSCs and PBS transplantation groups. (3) Wnt signaling pathway participates in the procession of differentiating into mature neurons derived from BMSCs overexpressing GDNF gene. After transplantation, the effects of BMSCs transplantation on spinal cord injury were improved by decreasing local inflammatory reaction, apoptosis and glial scar formation and promoting axonal regeneration.
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While hallmarks of rodent spermatogonia stem cell biomarkers' heterogeneity have recently been identified, their stage and subset distributions remain unclear. Furthermore, it is currently difficult to accurately identify subset-specific SSC marker distributions due to the poor nuclear morphological characteristics associated with fixation in 4% paraformaldehyde. In the present study, testicular cross-sections and whole-mount samples were Bouin fixed to optimize nuclear resolution and visualized by immunohistochemistry (IHC) and immunofluorescence (IF). The results identified an expression pattern of PLZFhighc-KITpos in A1 spermatogonia, while A2-A4-differentiating spermatogonia were PLZFlowc-KITpos. Additionally, this procedure was used to examine asymmetrically expressing GFRA1 and PLZF clones, asymmetric Apr and false clones were distinguished based on the presence or absence of TEX14, a molecular maker of intercellular bridges, despite having identical nuclear morphology and intercellular distances that were <25 μm. In conclusion, this optimized Bouin fixation procedure facilitates the accurate identification of spermatogonium subsets based on their molecular profiles and is capable of distinguishing asymmetric and false clones. Therefore, the findings presented herein will facilitate further morphological and functional analysis studies and provide further insight into spermatogonium subtypes.
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Objective@#To determine the effect of a motor-specific neurotrophic factor, glial-derived neurotrophic factor (GDNF) on motor nerve regeneration.@*Methods@#We used a nerve conduit filled with a fibrin-based delivery system that provided controlled release of GDNF during nerve regeneration. The motor branch of the rat femoral nerve was used to assess motor nerve regeneration across a 5-mm gap. Four experimental groups (n=5) were evaluated. These included GDNF with the fibrin-based delivery system (GDNF-DS group), fibrin alone(fibrin group), empty conduit (negative control group), and nerve isograft (positive control group). Nerves were harvested at 5 weeks for analysis by histomorphometry and electron microscopy.@*Results@#At 5 mm distal to the conduit or isografts, the GDNF-DS group was not significantly different from the nerve isograft group in the following histomorphometric measures: total nerve fibers, percentage of neural tissue, and nerve density. The number of nerve fibers (respectively: 1 744±274 , 1 481±288) and the percentage of nerve tissue [(14.2±3.9)%, (11.0±2.2)%] in theisograft group and the GDNF-DS group were significantly higher than that in the fibrin group and the empty conduit group [(respectively: 538±93, 535±96) and the percentage of nerve tissue respectively: (4.3±1.6)%, (3.7±0.9)%]. There were no differences in fiber width among all groups. By electron microscopy, the GDNF-DS and isograft groups also demonstrated more organized nerve architecture than the fibrin alone and empty conduit groups.@*Conclusions@#The delivery of GDNF from the fibrin-based delivery system promotes motor nerve regeneration at a level similar to an isograft in the femoral motor nerve model. This study gives insight into the potential beneficial role of GDNF in the treatment of motor nerve injuries.
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Objective To determine the effect of a motor-specific neurotrophic factor,glial-derived neurotrophic factor (GDNF) on motor nerve regeneration.Methods We used a nerve conduit filled with a fibrin-based delivery system that provided controlled release of GDNF during nerve regeneration.The motor branch of the rat femoral nerve was used to assess motor nerve regeneration across a 5-mm gap.Four experimental groups (n =5) were evaluated.These included GDNF with the fibrin-based delivery system (GDNFDS group),fibrin alone(fibrin group),empty conduit (negative control group),and nerve isograft (positive control group).Nerves were harvested at 5 weeks for analysis by histomorphometry and electron microscopy.Results At 5 mm distal to the conduit or isografts,the GDNF-DS group was not significantly different from the nerve isograft group in the following histomorphometric measures:total nerve fibers,percentage of neural tissue,and nerve density.The number of nerve fibers (respectively:1 744 ± 274,1 481 ± 288)and the percentage of nerve tissue [(14.2 ± 3.9) ％,(11.0 ± 2.2) ％] in theisograft group and the GDNFDS group were significantly higher than that in the fibrin group and the empty conduit group [(respectively:538 ± 93,535 ± 96) and the percentage of nerve tissue respectively:(4.3 ± 1.6) ％,(3.7 ± 0.9) ％].There were no differences in fiber width among all groups.By electron microscopy,the GDNF-DS and isograft groups also demonstrated more organized nerve architecture than the fibrin alone and empty conduit groups.Conclusions The delivery of GDNF from the fibrin-based delivery system promotes motor nerve regeneration at a level similar to an isograft in the femoral motor nerve model.This study gives insight into the potential beneficial role of GDNF in the treatment of motor nerve injuries.
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Objective To investigate the effect of the interaction between satellite glial cells and neurons in the trigeminal ganglion of trigeminal neuralgia (TN) rat model. Methods In the TN rat model (n = 24) induced by trigeminal root entry zone chronic compression and sham group (n = 24), immunofluorescence and Western blotting were used to detect the expression of myelin basic protein (MBP), glial fibrillary acidic protein (GFAP) and of P75 neurotrophic factor receptor (P75) in the trigeminal ganglion. Results The expression of P75NTR in TN group was higher than that in the sham operation group, especially on the post-operation day (POD) 7 and 14 (P<0.01). The expression of MBP in the TN group was decreased after operation, which were significant lower than that in the sham operation group on POD 7 and 14 (P<0.05). While the expression of immunoreactive GFAP in the satellite glial cells in the TN group was higher than that in the sham operation group from POD 7 to POD 21 after operation (P<0.01). Conclusion The changes of MBP and P75NTR expression in neurons and the activation of satellite glial cells in trigeminal ganglion of the TN animal model may affect the interaction of neuron-satellite glial cells, which may be involved in the nociceptive information transmission from orofacial area to the central nervous system in the TN rats.
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Spinal cord injury (SCI) causes axonal damage and demyelination, neural cell death, and comprehensive tissue loss, resulting in devastating neurological dysfunction. Neural stem/progenitor cell (NSPCs) transplantation provides therapeutic benefits for neural repair in SCI, and glial cell line-derived neurotrophic factor (GDNF) has been uncovered to have capability of stimulating axonal regeneration and remyelination after SCI. In this study, to evaluate whether GDNF would augment therapeutic effects of NSPCs for SCI, GDNF-encoding or mock adenoviral vector-transduced human NSPCs (GDNF-or Mock-hNSPCs) were transplanted into the injured thoracic spinal cords of rats at 7 days after SCI. Grafted GDNF-hNSPCs showed robust engraftment, long-term survival, an extensive distribution, and increased differentiation into neurons and oligodendroglial cells. Compared with Mock-hNSPC- and vehicle-injected groups, transplantation of GDNF-hNSPCs significantly reduced lesion volume and glial scar formation, promoted neurite outgrowth, axonal regeneration and myelination, increased Schwann cell migration that contributed to the myelin repair, and improved locomotor recovery. In addition, tract tracing demonstrated that transplantation of GDNF-hNSPCs reduced significantly axonal dieback of the dorsal corticospinal tract (dCST), and increased the levels of dCST collaterals, propriospinal neurons (PSNs), and contacts between dCST collaterals and PSNs in the cervical enlargement over that of the controls. Finally grafted GDNF-hNSPCs substantially reversed the increased expression of voltage-gated sodium channels and neuropeptide Y, and elevated expression of GABA in the injured spinal cord, which are involved in the attenuation of neuropathic pain after SCI. These findings suggest that implantation of GDNF-hNSPCs enhances therapeutic efficiency of hNSPCs-based cell therapy for SCI.