scholarly journals Glial Purinergic Signaling in Neurodegeneration

2021 ◽  
Vol 12 ◽  
Author(s):  
Marie J. Pietrowski ◽  
Amr Ahmed Gabr ◽  
Stanislav Kozlov ◽  
David Blum ◽  
Annett Halle ◽  
...  

Purinergic signaling regulates neuronal and glial cell functions in the healthy CNS. In neurodegenerative diseases, purinergic signaling becomes dysregulated and can affect disease-associated phenotypes of glial cells. In this review, we discuss how cell-specific expression patterns of purinergic signaling components change in neurodegeneration and how dysregulated glial purinergic signaling and crosstalk may contribute to disease pathophysiology, thus bearing promising potential for the development of new therapeutical options for neurodegenerative diseases.

2016 ◽  
Vol 74 (10) ◽  
pp. 849-854
Author(s):  
Paulo Victor Sgobbi de Souza ◽  
Wladimir Bocca Vieira de Rezende Pinto ◽  
Flávio Moura Rezende Filho ◽  
Acary Souza Bulle Oliveira

ABSTRACT Motor neuron disease is one of the major groups of neurodegenerative diseases, mainly represented by amyotrophic lateral sclerosis. Despite wide genetic and biochemical data regarding its pathophysiological mechanisms, motor neuron disease develops under a complex network of mechanisms not restricted to the unique functions of the alpha motor neurons but which actually involve diverse functions of glial cell interaction. This review aims to expose some of the leading roles of glial cells in the physiological mechanisms of neuron-glial cell interactions and the mechanisms related to motor neuron survival linked to glial cell functions.


Development ◽  
2000 ◽  
Vol 127 (12) ◽  
pp. 2515-2522 ◽  
Author(s):  
M. Hojo ◽  
T. Ohtsuka ◽  
N. Hashimoto ◽  
G. Gradwohl ◽  
F. Guillemot ◽  
...  

Neurons and glial cells differentiate from common precursors. Whereas the gene glial cells missing (gcm) determines the glial fate in Drosophila, current data about the expression patterns suggest that, in mammals, gcm homologues are unlikely to regulate gliogenesis. Here, we found that, in mouse retina, the bHLH gene Hes5 was specifically expressed by differentiating Muller glial cells and that misexpression of Hes5 with recombinant retrovirus significantly increased the population of glial cells at the expense of neurons. Conversely, Hes5-deficient retina showed 30–40% decrease of Muller glial cell number without affecting cell survival. These results indicate that Hes5 modulates glial cell fate specification in mouse retina.


2019 ◽  
Vol 20 (23) ◽  
pp. 5879 ◽  
Author(s):  
Sumaira Pervaiz ◽  
Anja Kopp ◽  
Lisa von Kleist ◽  
Tobias Stauber

The volume-regulated anion channel (VRAC) plays an important role in osmotic cell volume regulation. In addition, it is involved in various physiological processes such as insulin secretion, glia-neuron communication and purinergic signaling. VRAC is formed by hetero-hexamers of members of the LRRC8 protein family, which consists of five members, LRRC8A-E. LRRC8A is an essential subunit for physiological functionality of VRAC. Its obligate heteromerization with at least one of its paralogues, LRRC8B-E, determines the biophysical properties of VRAC. Moreover, the subunit composition is of physiological relevance as it largely influences the activation mechanism and especially the substrate selectivity. However, the endogenous tissue-specific subunit composition of VRAC is unknown. We have now developed and applied a quantitative immunoblot study of the five VRAC LRRC8 subunits in various mouse cell lines and tissues, using recombinant protein for signal calibration. We found tissue-specific expression patterns of the subunits, and generally relative low expression of the essential LRRC8A subunit. Immunoprecipitation of LRRC8A also co-precipitates an excess of the other subunits, suggesting that non-LRRC8A subunits present the majority in hetero-hexamers. With this, we can estimate that in the tested cell lines, the number of VRAC channels per cell is in the order of 10,000, which is in agreement with earlier calculations from the comparison of single-channel and whole-cell currents.


1994 ◽  
Vol 266 (5) ◽  
pp. C1301-C1312 ◽  
Author(s):  
V. L. Herrera ◽  
T. Cova ◽  
D. Sassoon ◽  
N. Ruiz-Opazo

Na(+)-K(+)-activated adenosine triphosphatase (Na(+)-K(+)-ATPase) is the integral membrane protein that maintains the Na(+)-K(+) electrochemical gradient across the plasma membrane. Because of the importance of the Na(+)-K(+) electrochemical gradient to fundamental and specialized cell functions, we investigated the cell-specific modulation of Na(+)-K(+)-ATPase alpha-subunit isoform (alpha 1, alpha 2, and alpha 3) gene expression in different stages of postimplantation mouse embryos and neonatal rat tissues by in situ hybridization with use of isoform-specific rat-derived antisense RNA probes. At early organogenesis (9.5-10.5 days postcoitus), we demonstrated generalized coexpression of alpha 1- and alpha 2-isoforms throughout the mouse embryo with greater levels in the developing but already functional heart, in contrast to the distinct spatially restricted alpha 3-isoform gene expression in the early developing neural tube. At midorganogenesis (15.5-16.5 days postcoitus), differential spatial variation in alpha 1-, alpha 2-, and alpha 3-isoform gene expression was already evident in all organs. Interestingly, region-specific expression patterns within single cell types were noted throughout development and were exemplified by 1) alpha 3-isoform gene expression in marginal cells of the 10.5-day-postcoitus developing neural tube; 2) alpha 1-, alpha 2-, and alpha 3-isoform gene expression in cerebellar granular cells of the 4-day-old rat brain; and 3) alpha 1- and alpha 3-isoform gene expression in 4-day-old rat ventricular cardiomyocytes. These isoform-specific changes in cellular and regional Na(+)-K(+)-ATPase alpha-isoform gene expression may play an active role in development and specialized cell functions.


2021 ◽  
Vol 15 ◽  
Author(s):  
Junko Nio-Kobayashi ◽  
Tetsuya Itabashi

Galectins are β-galactoside-binding lectins consisting of 15 members in mammals. Galectin-1,-3,-4,-8, and -9 are predominantly expressed in the central nervous system (CNS) and regulate various physiological and pathological events. This review summarizes the current knowledge of the cellular expression and role of galectins in the CNS, and discusses their functions in neurite outgrowth, myelination, and neural stem/progenitor cell niches, as well as in ischemic/hypoxic/traumatic injuries and neurodegenerative diseases such as multiple sclerosis. Galectins are expressed in both neurons and glial cells. Galectin-1 is mainly expressed in motoneurons, whereas galectin-3-positive neurons are broadly distributed throughout the brain, especially in the hypothalamus, indicating its function in the regulation of homeostasis, stress response, and the endocrine/autonomic system. Astrocytes predominantly contain galectin-1, and galectin-3 and−9 are upregulated along with its activation. Activated, but not resting, microglia contain galectin-3, supporting its phagocytic activity. Galectin-1,−3, and -4 are characteristically expressed during oligodendrocyte differentiation. Galectin-3 from microglia promotes oligodendrocyte differentiation and myelination, while galectin-1 and axonal galectin-4 suppress its differentiation and myelination. Galectin-1- and- 3-positive cells are involved in neural stem cell niche formation in the subventricular zone and hippocampal dentate gyrus, and the migration of newly generated neurons and glial cells to the olfactory bulb or damaged lesions. In neurodegenerative diseases, galectin-1,-8, and -9 have neuroprotective and anti-inflammatory activities. Galectin-3 facilitates pro-inflammatory action; however, it also plays an important role during the recovery period. Several ligand glycoconjugates have been identified so far such as laminin, integrins, neural cell adhesion molecule L1, sulfatide, neuropilin-1/plexinA4 receptor complex, triggering receptor on myeloid cells 2, and T cell immunoglobulin and mucin domain. N-glycan branching on lymphocytes and oligodendroglial progenitors mediated by β1,6-N-acetylglucosaminyltransferase V (Mgat5/GnTV) influences galectin-binding, modulating inflammatory responses and remyelination in neurodegenerative diseases. De-sulfated galactosaminoglycans such as keratan sulfate are potential ligands for galectins, especially galectin-3, regulating neural regeneration. Galectins have multitudinous functions depending on cell type and context as well as post-translational modifications, including oxidization, phosphorylation, S-nitrosylation, and cleavage, but there should be certain rules in the expression patterns of galectins and their ligand glycoconjugates, possibly related to glucose metabolism in cells.


2013 ◽  
Author(s):  
AL Bookout ◽  
Y Jeong ◽  
M Downes ◽  
RT Yu ◽  
RM Evans ◽  
...  

2020 ◽  
Vol 21 (7) ◽  
pp. 722-734
Author(s):  
Adele Soltani ◽  
Arefeh Jafarian ◽  
Abdolamir Allameh

micro (mi)-RNAs are vital regulators of multiple processes including insulin signaling pathways and glucose metabolism. Pancreatic β-cells function is dependent on some miRNAs and their target mRNA, which together form a complex regulative network. Several miRNAs are known to be directly involved in β-cells functions such as insulin expression and secretion. These small RNAs may also play significant roles in the fate of β-cells such as proliferation, differentiation, survival and apoptosis. Among the miRNAs, miR-7, miR-9, miR-375, miR-130 and miR-124 are of particular interest due to being highly expressed in these cells. Under diabetic conditions, although no specific miRNA profile has been noticed, the expression of some miRNAs and their target mRNAs are altered by posttranscriptional mechanisms, exerting diverse signs in the pathobiology of various diabetic complications. The aim of this review article is to discuss miRNAs involved in the process of stem cells differentiation into β-cells, resulting in enhanced β-cell functions with respect to diabetic disorders. This paper will also look into the impact of miRNA expression patterns on in vitro proliferation and differentiation of β-cells. The efficacy of the computational genomics and biochemical analysis to link the changes in miRNA expression profiles of stem cell-derived β-cells to therapeutically relevant outputs will be discussed as well.


2019 ◽  
Vol 20 (15) ◽  
pp. 3679 ◽  
Author(s):  
Lin Chen ◽  
Alyne Simões ◽  
Zujian Chen ◽  
Yan Zhao ◽  
Xinming Wu ◽  
...  

Wounds within the oral mucosa are known to heal more rapidly than skin wounds. Recent studies suggest that differences in the microRNAome profiles may underlie the exceptional healing that occurs in oral mucosa. Here, we test whether skin wound-healing can be accelerating by increasing the levels of oral mucosa-specific microRNAs. A panel of 57 differentially expressed high expresser microRNAs were identified based on our previously published miR-seq dataset of paired skin and oral mucosal wound-healing [Sci. Rep. (2019) 9:7160]. These microRNAs were further grouped into 5 clusters based on their expression patterns, and their differential expression was confirmed by TaqMan-based quantification of LCM-captured epithelial cells from the wound edges. Of these 5 clusters, Cluster IV (consisting of 8 microRNAs, including miR-31) is most intriguing due to its tissue-specific expression pattern and temporal changes during wound-healing. The in vitro functional assays show that ectopic transfection of miR-31 consistently enhanced keratinocyte proliferation and migration. In vivo, miR-31 mimic treatment led to a statistically significant acceleration of wound closure. Our results demonstrate that wound-healing can be enhanced in skin through the overexpression of microRNAs that are highly expressed in the privileged healing response of the oral mucosa.


2021 ◽  
Vol 4 (Supplement_1) ◽  
pp. 278-279
Author(s):  
M Defaye ◽  
N Abdullah ◽  
M Iftinca ◽  
C Altier

Abstract Background Long-lasting changes in neural pain circuits precipitate the transition from acute to chronic pain in patients living with inflammatory bowel diseases (IBDs). While significant improvement in IBD therapy has been made to reduce inflammation, a large subset of patients continues to suffer throughout quiescent phases of the disease, suggesting a high level of plasticity in nociceptive circuits during acute phases. The establishment of chronic visceral pain results from neuroplasticity in nociceptors first, then along the entire neural axis, wherein microglia, the resident immune cells of the central nervous system, are critically involved. Our lab has shown that spinal microglia were key in controlling chronic pain state in IBD. Using the Dextran Sodium Sulfate (DSS) model of colitis, we found that microglial G-CSF was able to sensitize colonic nociceptors that express the pain receptor TRPV1. While TRPV1+ nociceptors have been implicated in peripheral sensitization, their contribution to central sensitization via microglia remains unknown. Aims To investigate the role of TRPV1+ visceral afferents in microglial activation and chronic visceral pain. Methods We generated DREADD (Designer Receptors Exclusively Activated by Designer Drugs) mice in which TRPV1 sensory neurons can be inhibited (TRPV1-hM4Di) or activated (TRPV1-hM3Dq) in a time and tissue specific manner using the inert ligand Clozapine-N-Oxide (CNO). To test the inhibition of TRPV1 neurons in DSS-induced colitis, TRPV1-hM4Di mice were treated with DSS 2.5% or water for 7 days and received vehicle or CNO i.p. injection twice daily. To activate TRPV1 visceral afferents, TRPV1-hM3Dq mice received vehicle or CNO daily for 7 days, by oral gavage. After 7 days of treatment, visceral pain was evaluated by colorectal distension and spinal cords tissues were harvested to measure microglial activation. Results Our data validated the nociceptor specific expression and function of the DREADD in TRPV1-Cre mice. Inhibition of TRPV1 visceral afferents in DSS TRPV1-hM4Di mice was able to prevent the colitis-induced microglial activation and thus reduce visceral hypersensitivity. In contrast, activation of TRPV1 visceral afferents in TRPV1-hM3Dq mice was sufficient to drive microglial activation in the absence of colitis. Analysis of the proalgesic mediators derived from activated TRPV1-hM3Dq neurons identified ATP as a key factor of microglial activation. Conclusions Overall, these data provide novel insights into the mechanistic understanding of the gut/brain axis in chronic visceral pain and suggest a role of purinergic signaling that could be harnessed for testing effective therapeutic approaches to relieve pain in IBD patients. Funding Agencies CCCACHRI (Alberta Children’s Hospital Research Institute) and CSM (Cumming School of Medicine) postdoctoral fellowship


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Leyla A. Erozenci ◽  
Sander R. Piersma ◽  
Thang V. Pham ◽  
Irene V. Bijnsdorp ◽  
Connie R. Jimenez

AbstractThe protein content of urinary extracellular vesicles (EVs) is considered to be an attractive non-invasive biomarker source. However, little is known about the consistency and variability of urinary EV proteins within and between individuals over a longer time-period. Here, we evaluated the stability of the urinary EV proteomes of 8 healthy individuals at 9 timepoints over 6 months using data-independent-acquisition mass spectrometry. The 1802 identified proteins had a high correlation amongst all samples, with 40% of the proteome detected in every sample and 90% detected in more than 1 individual at all timepoints. Unsupervised analysis of top 10% most variable proteins yielded person-specific profiles. The core EV-protein-interaction network of 516 proteins detected in all measured samples revealed sub-clusters involved in the biological processes of G-protein signaling, cytoskeletal transport, cellular energy metabolism and immunity. Furthermore, gender-specific expression patterns were detected in the urinary EV proteome. Our findings indicate that the urinary EV proteome is stable in longitudinal samples of healthy subjects over a prolonged time-period, further underscoring its potential for reliable non-invasive diagnostic/prognostic biomarkers.


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