scholarly journals CD34 Identifies a Subset of Proliferating Microglial Cells Associated with Degenerating Motor Neurons in ALS

2019 ◽  
Vol 20 (16) ◽  
pp. 3880 ◽  
Author(s):  
Mariángeles Kovacs ◽  
Emiliano Trias ◽  
Valentina Varela ◽  
Sofia Ibarburu ◽  
Joseph S. Beckman ◽  
...  

Amyotrophic lateral sclerosis (ALS) is characterized by degeneration of upper and lower motor neurons accompanied by proliferation of reactive microglia in affected regions. However, it is unknown whether the hematopoietic marker CD34 can identify a subpopulation of proliferating microglial cells in the ALS degenerating spinal cord. Immunohistochemistry for CD34 and microglia markers was performed in lumbar spinal cords of ALS rats bearing the SOD1G93A mutation and autopsied ALS and control human subjects. Characterization of CD34-positive cells was also performed in primary cell cultures of the rat spinal cords. CD34 was expressed in a large number of cells that closely interacted with degenerating lumbar spinal cord motor neurons in symptomatic SOD1G93A rats, but not in controls. Most CD34+ cells co-expressed the myeloid marker CD11b, while only a subpopulation was stained for Iba1 or CD68. Notably, CD34+ cells actively proliferated and formed clusters adjacent to damaged motor neurons bearing misfolded SOD1. CD34+ cells were identified in the proximity of motor neurons in autopsied spinal cord from sporadic ALS subjects but not in controls. Cell culture of symptomatic SOD1G93A rat spinal cords yielded a large number of CD34+ cells exclusively in the non-adherent phase, which generated microglia after successive passaging. A yet unrecognized CD34+ cells, expressing or not the microglial marker Iba1, proliferate and accumulate adjacent to degenerating spinal motor neurons, representing an intriguing cell target for approaching ALS pathogenesis and therapeutics.

2019 ◽  
Vol 33 (3) ◽  
pp. 225-231 ◽  
Author(s):  
Kazu Kobayakawa ◽  
Kyleigh Alexis DePetro ◽  
Hui Zhong ◽  
Bau Pham ◽  
Masamitsu Hara ◽  
...  

Background. We previously demonstrated that step training leads to reorganization of neuronal networks in the lumbar spinal cord of rodents after a hemisection (HX) injury and step training, including increases excitability of spinally evoked potentials in hindlimb motor neurons. Methods. In this study, we investigated changes in RNA expression and synapse number using RNA-Seq and immunohistochemistry of the lumbar spinal cord 23 days after a mid-thoracic HX in rats with and without post-HX step training. Results. Gene Ontology (GO) term clustering demonstrated that expression levels of 36 synapse-related genes were increased in trained compared with nontrained rats. Many synaptic genes were upregulated in trained rats, but Lrrc4 (coding NGL-2) was the most highly expressed in the lumbar spinal cord caudal to the HX lesion. Trained rats also had a higher number of NGL-2/synaptophysin synaptic puncta in the lumbar ventral horn. Conclusions. Our findings demonstrate clear activity-dependent regulation of synapse-related gene expression post-HX. This effect is consistent with the concept that activity-dependent phenomena can provide a mechanistic drive for epigenetic neuronal group selection in the shaping of the reorganization of synaptic networks to learn the locomotion task being trained after spinal cord injury.


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Yu-Ting Zhang ◽  
Hui Jin ◽  
Jun-Hua Wang ◽  
Lan-Yu Wen ◽  
Yang Yang ◽  
...  

Spinal cord injury (SCI) often results in death of spinal neurons and atrophy of muscles which they govern. Thus, following SCI, reorganizing the lumbar spinal sensorimotor pathways is crucial to alleviate muscle atrophy. Tail nerve electrical stimulation (TANES) has been shown to activate the central pattern generator (CPG) and improve the locomotion recovery of spinal contused rats. Electroacupuncture (EA) is a traditional Chinese medical practice which has been proven to have a neural protective effect. Here, we examined the effects of TANES and EA on lumbar motor neurons and hindlimb muscle in spinal transected rats, respectively. From the third day postsurgery, rats in the TANES group were treated 5 times a week and those in the EA group were treated once every other day. Four weeks later, both TANES and EA showed a significant impact in promoting survival of lumbar motor neurons and expression of choline acetyltransferase (ChAT) and ameliorating atrophy of hindlimb muscle after SCI. Meanwhile, the expression of neurotrophin-3 (NT-3) in the same spinal cord segment was significantly increased. These findings suggest that TANES and EA can augment the expression of NT-3 in the lumbar spinal cord that appears to protect the motor neurons as well as alleviate muscle atrophy.


2021 ◽  
Vol 12 ◽  
Author(s):  
Fangliang Guo ◽  
Xiaolong Zheng ◽  
Ziyu He ◽  
Ruoying Zhang ◽  
Song Zhang ◽  
...  

Spinal cord injury (SCI) is a devastating condition that results in severe motor, sensory, and autonomic dysfunction. The L-/T-type calcium channel blocker nimodipine (NMD) exerts a protective effect on neuronal injury; however, the protective effects of long-term administration of NMD in subjects with SCI remain unknown. Thus, the aim of this study was to evaluate the role of long-term treatment with NMD on a clinically relevant SCI model. Female rats with SCI induced by 25 mm contusion were subcutaneously injected with vehicle or 10 mg/kg NMD daily for six consecutive weeks. We monitored the motor score, hind limb grip strength, pain-related behaviors, and bladder function in this study to assess the efficacy of NMD in rats with SCI. Rats treated with NMD showed improvements in locomotion, pain-related behaviors, and spasticity-like symptoms, but not in open-field spontaneous activity, hind limb grip strength or bladder function. SCI lesion areas and perilesional neuronal numbers, gliosis and calcitonin gene-related peptide (CGRP+) fiber sprouting in the lumbar spinal cord and the expression of K+–Cl− cotransporter 2 (KCC2) on lumbar motor neurons were also observed to further explore the possible protective mechanisms of NMD. NMD-treated rats showed greater tissue preservation with reduced lesion areas and increased perilesional neuronal sparing. NMD-treated rats also showed improvements in gliosis, CGRP+ fiber sprouting in the lumbar spinal cord, and KCC2 expression in lumbar motor neurons. Together, these results indicate that long-term treatment with NMD improves functional recovery after SCI, which may provide a potential therapeutic strategy for the treatment of SCI.


2018 ◽  
Author(s):  
Virginia B. Garcia ◽  
Matthew D. Abbinanti ◽  
Ronald M. Harris-Warrick ◽  
David J. Schulz

ABSTRACTSpinal cord injury (SCI) causes widespread changes in gene expression of the spinal cord, even in the undamaged spinal cord below the level of the lesion. Less is known about changes in the correlated expression of genes after SCI. We investigated gene co-expression networks among voltage-gated ion channel and neurotransmitter receptor mRNA levels using quantitative RT-PCR in longitudinal slices of the mouse lumbar spinal cord in control and chronic SCI animals. These longitudinal slices were made from the ventral surface of the cord, thus forming slices relatively enriched in motor neurons or interneurons. We performed absolute quantitation of mRNA copy number for 50 ion channel or receptor transcripts from each sample, and used multiple correlation analyses to detect patterns in correlated mRNA levels across all pairs of genes. The majority of channels and receptors changed in expression as a result of chronic SCI, but did so differently across slice levels. Furthermore, motor neuron enriched slices experienced an overall loss of correlated channel and receptor expression, while interneuron slices showed a dramatic increase in the number of positively correlated transcripts. These correlation profiles suggest that spinal cord injury induces distinct changes across cell types in the organization of gene co-expression networks for ion channels and transmitter receptors.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Sara Berjaoui ◽  
Mónica Povedano ◽  
Paula Garcia-Esparcia ◽  
Margarita Carmona ◽  
Ester Aso ◽  
...  

Inflammatory changes are analyzed in the anterior spinal cord and frontal cortex area 8 in typical spinal-predominant ALS cases. Increased numbers of astrocytes and activated microglia are found in the anterior horn of the spinal cord and pyramidal tracts. Significant increased expression ofTLR7,CTSS, andCTSCmRNA and a trend to increased expression ofIL10RA,TGFB1, andTGFB2are found in the anterior lumbar spinal cord in ALS cases compared to control cases, whereasC1QTNF7andTNFRSF1AmRNA expression levels are significantly decreased.IL6is significantly upregulated andIL1Bshows a nonsignificant increased expression in frontal cortex area 8 in ALS cases. IL-6 immunoreactivity is found in scattered monocyte-derived macrophages/microglia and TNF-αin a few cells of unknown origin in ALS cases. Increased expression and abnormal distribution of IL-1βoccurred in motor neurons of the lumbar spinal cord in ALS. Strong IL-10 immunoreactivity colocalizes with TDP-43-positive inclusions in motor neurons in ALS cases. The present observations show a complex participation of cytokines and mediators of the inflammatory response in ALS consistent with increased proinflammatory cytokines and sequestration of anti-inflammatory IL-10 in affected neurons.


2000 ◽  
Vol 93 (2) ◽  
pp. 266-275 ◽  
Author(s):  
Bassam Hadi ◽  
Y. Ping Zhang ◽  
Darlene A. Burke ◽  
Christopher B. Shields ◽  
David S. K. Magnuson

Object. The aims of this study were to investigate further the role played by lumbar spinal cord interneurons in the generation of locomotor activity and to develop a model of spinal cord injury suitable for testing neuron replacement strategies. Methods. Adult rats received intraspinal injections of kainic acid (KA). Locomotion was assessed weekly for 4 weeks by using the Basso, Beattie, and Bresnahan (BBB) 21-point locomotor scale, and transcranial magnetic motor evoked potentials (MMEPs) were recorded in gastrocnemius and quadriceps muscles at 1 and 4 weeks. No changes in transcranial MMEP latency were noted following KA injection, indicating that the descending motor pathways responsible for these responses, including the alpha motor neurons, were not compromised. Rats in which KA injections included much of the L-2 segment (10 animals) showed severe locomotor deficits, with a mean BBB score of 4.5 ± 3.6 (± standard deviation). Rats that received lesions rostral to the L-2 segment (four animals) were able to locomote and had a mean BBB score of 14.6 ± 2.6. Three rats that received only one injection bilaterally centered at L-2 (three animals) had a mean BBB score of 3.2 ± 2. Histological examination revealed variable loss of motor neurons limited to the injection site. There was no correlation between motor neuron loss and BBB score. Conclusions. Interneuron loss centered on the L-2 segment induces lasting paraplegia independent of motor neuron loss and white matter damage, supporting earlier suggestions that circuitry critical to the generator of locomotor activity (the central pattern generator) resides in this area. This injury model may prove ideal for studies of neuron replacement strategies.


1982 ◽  
Vol 30 (5) ◽  
pp. 425-435 ◽  
Author(s):  
K A Carson ◽  
M M Mesulam

Eight methods for the electron microscopic demonstration of horseradish peroxidase (HRP) labeling have been compared in adjacent series of vibratome sections of mouse lumbar spinal cord. The tracer, a HRP-wheat germ agglutinin (WGA) conjugate, was injected into the gastrocnemius muscle complex. Following retrograde axonal transport to the lumbar motor neurons and transganglionic anterograde transport of the tracer to the dorsal horn, the HRP activity was demonstrated in eight series of adjacent sections of lumbar spinal cord using eight methods. These included procedures using tetramethylbenzidine (TMB), benzidine dihydrochloride (BDHC), o-tolidine, paraphenylenediamine-pyrocatechol (PPD-PC), and 4 methods using 3,3'-diaminobenzidine (DAB). All eight methods were able to demonstrate both retrograde labeling of motor neurons and transganglionic anterograde transport into the dorsal horn. However, there were differences in the appearance of the various reaction products under the electron microscope. In addition, differences in the distribution of the reaction products were observed by both light and electron microscopy. The largest distribution of reaction product was observed with TMB. BDHC and o-tolidine were next, followed by the DAB procedures and PPD-PC. The TMB, BDHC, and o-tolidine reaction products were all found to be suitable for electron microscopy. The TMB reaction product was electron dense and had a very distinctive crystalloid appearance that made identification of HRP-labeled neuronal profiles easy and unequivocal.


2021 ◽  
Author(s):  
Jack Humphrey ◽  
Sanan Venkatesh ◽  
Rahat Hasan ◽  
Jake T Herb ◽  
Katia de Paiva Lopes ◽  
...  

Amyotrophic lateral sclerosis (ALS) is a progressively fatal neurodegenerative disease affecting motor neurons in the brain and spinal cord. We used 380 post-mortem tissue RNA-seq transcriptomes from 154 ALS cases and 49 control individuals from cervical, thoracic, and lumbar spinal cord segments to investigate the gene expression response to ALS. We observed an increase in microglia and astrocyte expression, accompanied by a decrease in oligodendrocytes. By creating a gene co-expression network in the ALS samples, we identify several activated microglia modules that negatively correlate with retrospective disease duration. We map molecular quantitative trait loci and find several potential ALS risk loci that may act through gene expression or splicing in the spinal cord and assign putative cell-types for FNBP1, ACSL5, SH3RF1 and NFASC. Finally, we outline how repeat expansions that alter splicing of C9orf72 are tagged by common variants, and use this to suggest ATXN3 as a putative risk gene.


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