scholarly journals P2X7 Receptor Agonist 2′(3′)-O-(4-Benzoylbenzoyl)ATP Differently Modulates Cell Viability and Corticostriatal Synaptic Transmission in Experimental Models of Huntington’s Disease

2021 ◽  
Vol 11 ◽  
Author(s):  
Alberto Martire ◽  
Rita Pepponi ◽  
Francesco Liguori ◽  
Cinzia Volonté ◽  
Patrizia Popoli

Huntington’s disease (HD) is a life-threatening neurodegenerative disorder. Altered levels and functions of the purinergic ionotropic P2X7 receptors (P2X7Rs) have been found in animal and cellular models of HD, suggesting their possible role in the pathogenesis of the disease; accordingly, the therapeutic potential of P2X7R antagonists in HD has been proposed. Here we further investigated the effects of P2X7R ligands in in vitro and ex vivo HD experimental models. In ST14A/Q120 rat striatal cells, we found a reduction of P2X7R expression; however, the P2X7R agonist 2′(3′)-O-(4-benzoylbenzoyl)adenosine-5′-triphosphate (BzATP) induced cellular death, and this effect was fully reversed by the antagonist periodate-oxidized adenosine 5′-triphosphate (OxATP). Moreover, in corticostriatal slices from symptomatic R6/2 mice, BzATP reduced the synaptic transmission to a larger extent than in wild-type (WT) mice. Such an effect was accompanied by a concomitant increase of the paired-pulse ratio, suggesting a presynaptic inhibitory action. This was confirmed to be the case, since while the effects of BzATP were unaffected by the P2X7R antagonist OxATP, they were blocked by the adenosine A1 receptor (A1R) antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), suggesting possible BzATP hydrolysis to 2′(3′)-O-(4-benzoylbenzoyl)adenosine (Bz-adenosine) and consequent activation of A1Rs as a mechanism. Taken together, these data point out that 1) P2X7R expression and activity are confirmed to be altered in the presence of HD mutation; 2) in some experimental settings, such an abnormal functioning can be ascribed to presynaptic A1Rs activation.

2020 ◽  
Vol 11 (7) ◽  
Author(s):  
Alba Di Pardo ◽  
Elena Ciaglia ◽  
Monica Cattaneo ◽  
Anna Maciag ◽  
Francesco Montella ◽  
...  

Abstract The longevity-associated variant (LAV) of the bactericidal/permeability-increasing fold-containing family B member 4 (BPIFB4) has been found significantly enriched in long-living individuals. Neuroinflammation is a key player in Huntington’s disease (HD), a neurodegenerative disorder caused by neural death due to expanded CAG repeats encoding a long polyglutamine tract in the huntingtin protein (Htt). Herein, we showed that striatal-derived cell lines with expanded Htt (STHdh Q111/111) expressed and secreted lower levels of BPIFB4, when compared with Htt expressing cells (STHdh Q7/7), which correlated with a defective stress response to proteasome inhibition. Overexpression of LAV-BPIFB4 in STHdh Q111/111 cells was able to rescue both the BPIFB4 secretory profile and the proliferative/survival response. According to a well-established immunomodulatory role of LAV-BPIFB4, conditioned media from LAV-BPIFB4-overexpressing STHdh Q111/111 cells were able to educate Immortalized Human Microglia—SV40 microglial cells. While STHdh Q111/111 dying cells were ineffective to induce a CD163 + IL-10high pro-resolving microglia compared to normal STHdh Q7/7, LAV-BPIFB4 transduction promptly restored the central immune control through a mechanism involving the stromal cell-derived factor-1. In line with the in vitro results, adeno-associated viral-mediated administration of LAV-BPIFB4 exerted a CXCR4-dependent neuroprotective action in vivo in the R6/2 HD mouse model by preventing important hallmarks of the disease including motor dysfunction, body weight loss, and mutant huntingtin protein aggregation. In this view, LAV-BPIFB4, due to its pleiotropic ability in both immune compartment and cellular homeostasis, may represent a candidate for developing new treatment for HD.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Alexandra V. Goodnight ◽  
Isaac Kremsky ◽  
Sujittra Khampang ◽  
Yoon Hee Jung ◽  
James M. Billingsley ◽  
...  

Abstract Background Huntington’s Disease (HD) is a fatal neurodegenerative disorder caused by a CAG repeat expansion, resulting in a mutant huntingtin protein. While it is now clear that astrocytes are affected by HD and significantly contribute to neuronal dysfunction and pathogenesis, the alterations in the transcriptional and epigenetic profiles in HD astrocytes have yet to be characterized. Here, we examine global transcription and chromatin accessibility dynamics during in vitro astrocyte differentiation in a transgenic non-human primate model of HD. Results We found global changes in accessibility and transcription across different stages of HD pluripotent stem cell differentiation, with distinct trends first observed in neural progenitor cells (NPCs), once cells have committed to a neural lineage. Transcription of p53 signaling and cell cycle pathway genes was highly impacted during differentiation, with depletion in HD NPCs and upregulation in HD astrocytes. E2F target genes also displayed this inverse expression pattern, and strong associations between E2F target gene expression and accessibility at nearby putative enhancers were observed. Conclusions The results suggest that chromatin accessibility and transcription are altered throughout in vitro HD astrocyte differentiation and provide evidence that E2F dysregulation contributes to aberrant cell-cycle re-entry and apoptosis throughout the progression from NPCs to astrocytes.


2021 ◽  
Vol 14 ◽  
Author(s):  
Sean Austin O. Lim ◽  
D. James Surmeier

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder that initially manifests itself in the striatum. How intrastriatal circuitry is altered by the disease is poorly understood. To help fill this gap, the circuitry linking spiny projection neurons (SPNs) to cholinergic interneurons (ChIs) was examined using electrophysiological and optogenetic approaches in ex vivo brain slices from wildtype mice and zQ175+/− models of HD. These studies revealed a severalfold enhancement of GABAergic inhibition of ChIs mediated by collaterals of indirect pathway SPNs (iSPNs), but not direct pathway SPNs (dSPNs). This cell-specific alteration in synaptic transmission appeared in parallel with the emergence of motor symptoms in the zQ175+/− model. The adaptation had a presynaptic locus, as it was accompanied by a reduction in paired-pulse ratio but not in the postsynaptic response to GABA. The alterations in striatal GABAergic signaling disrupted spontaneous ChI activity, potentially contributing to the network dysfunction underlying the hyperkinetic phase of HD.


Author(s):  
I. Luísa Ferreira ◽  
Catarina Carmo ◽  
Luana Naia ◽  
Sandra I. Mota ◽  
A. Cristina Rego

2001 ◽  
Vol 31 (1) ◽  
pp. 3-14 ◽  
Author(s):  
L. W. HO ◽  
J. CARMICHAEL ◽  
J. SWARTZ ◽  
A. WYTTENBACH ◽  
J. RANKIN ◽  
...  

Background. Huntington's disease (HD) is a fatal neurodegenerative disorder with an autosomal dominant mode of inheritance. It leads to progressive dementia, psychiatric symptoms and an incapacitating choreiform movement disorder, culminating in premature death. HD is caused by an increased CAG repeat number in a gene coding for a protein with unknown function, called huntingtin. The trinucleotide CAG codes for the amino acid glutamine and the expanded CAG repeats are translated into a series of uninterrupted glutamine residues (a polyglutamine tract).Methods. This review describes the epidemiology, clinical symptomatology, neuropathological features and genetics of HD. The main aim is to examine important findings from animal and cellular models and evaluate how they have enriched our understanding of the pathogenesis of HD and other diseases caused by expanded polyglutamine tracts.Results. Selective death of striatal and cortical neurons occurs. It is likely that the HD mutation confers a deleterious gain of function on the protein. Neuronal intranuclear inclusions containing huntingtin and ubiquitin develop in patients and transgenic mouse models of HD. Other proposed mechanisms contributing to neuropathology include excitotoxicity, oxidative stress, impaired energy metabolism, abnormal protein interactions and apoptosis.Conclusions. Although many interesting findings have accumulated from studies of HD and other polyglutamine diseases, there remain many unresolved issues pertaining to the exact roles of intranuclear inclusions and protein aggregates, the mechanisms of selective neuronal death and delayed onset of illness. Further knowledge in these areas will inspire the development of novel therapeutic strategies.


2010 ◽  
Vol 1 (2) ◽  
Author(s):  
Jun Wang ◽  
Cathie Pfleger ◽  
Lauren Friedman ◽  
Roselle Vittorino ◽  
Wei Zhao ◽  
...  

AbstractHuntington’s disease (HD) is a progressive neurodegenerative disorder associated with selective neuronal cell death. Abnormal aggregation of huntingtin protein with polyQ expansion has been shown to be causally linked to HD. Grape seed polyphenolic extract (GSPE) is a natural compound that has previously been shown to interfere with aggregations of proteins involved in neurological disorders, such as amyloid beta peptides (Aβ) and Tau protein. In this study we found that GSPE treatment significantly inhibits polyQ aggregation in phaeochromocytoma (PC)-12 cell line containing an ecdysone-inducible protein comprising the first 17 amino acid of huntingtin plus 103 glutamines fused with enhanced GFP. In vivo feasibility studies using the Q93httexon1 drosophila model of HD, we extended our in vitro evidence and found that flies fed with GSPE had a significantly improved lifespan compared to the control flies. Using the R6/2 rodent model of HD, we found that oral administration of 100 mg/kg/day GSPE (equivalent to 500mg per day in human) significantly attenuated the motor skill decay as well as extended the lifespan in the R6/2 mice relative to vehicle-control mice. Collectively, our studies strongly suggest that GSPE might be able to modulate the onset and/or progression of HD.


2009 ◽  
Vol 37 (6) ◽  
pp. 1270-1275 ◽  
Author(s):  
Angela Bithell ◽  
Rory Johnson ◽  
Noel J. Buckley

HD (Huntington's disease) is a late onset heritable neurodegenerative disorder that is characterized by neuronal dysfunction and death, particularly in the cerebral cortex and medium spiny neurons of the striatum. This is followed by progressive chorea, dementia and emotional dysfunction, eventually resulting in death. HD is caused by an expanded CAG repeat in the first exon of the HD gene that results in an abnormally elongated polyQ (polyglutamine) tract in its protein product, Htt (Huntingtin). Wild-type Htt is largely cytoplasmic; however, in HD, proteolytic N-terminal fragments of Htt form insoluble deposits in both the cytoplasm and nucleus, provoking the idea that mutHtt (mutant Htt) causes transcriptional dysfunction. While a number of specific transcription factors and co-factors have been proposed as mediators of mutHtt toxicity, the causal relationship between these Htt/transcription factor interactions and HD pathology remains unknown. Previous work has highlighted REST [RE1 (repressor element 1)-silencing transcription factor] as one such transcription factor. REST is a master regulator of neuronal genes, repressing their expression. Many of its direct target genes are known or suspected to have a role in HD pathogenesis, including BDNF (brain-derived neurotrophic factor). Recent evidence has also shown that REST regulates transcription of regulatory miRNAs (microRNAs), many of which are known to regulate neuronal gene expression and are dysregulated in HD. Thus repression of miRNAs constitutes a second, indirect mechanism by which REST can alter the neuronal transcriptome in HD. We will describe the evidence that disruption to the REST regulon brought about by a loss of interaction between REST and mutHtt may be a key contributory factor in the widespread dysregulation of gene expression in HD.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kim Le Cann ◽  
Alec Foerster ◽  
Corinna Rösseler ◽  
Andelain Erickson ◽  
Petra Hautvast ◽  
...  

AbstractHuntington’s disease (HD) is an autosomal dominant neurodegenerative disorder caused by an expanded polyglutamine repeat in the huntingtin gene. The neuropathology of HD is characterized by the decline of a specific neuronal population within the brain, the striatal medium spiny neurons (MSNs). The origins of this extreme vulnerability remain unknown. Human induced pluripotent stem cell (hiPS cell)-derived MSNs represent a powerful tool to study this genetic disease. However, the differentiation protocols published so far show a high heterogeneity of neuronal populations in vitro. Here, we compared two previously published protocols to obtain hiPS cell-derived striatal neurons from both healthy donors and HD patients. Patch-clamp experiments, immunostaining and RT-qPCR were performed to characterize the neurons in culture. While the neurons were mature enough to fire action potentials, a majority failed to express markers typical for MSNs. Voltage-clamp experiments on voltage-gated sodium (Nav) channels revealed a large variability between the two differentiation protocols. Action potential analysis did not reveal changes induced by the HD mutation. This study attempts to demonstrate the current challenges in reproducing data of previously published differentiation protocols and in generating hiPS cell-derived striatal MSNs to model a genetic neurodegenerative disorder in vitro.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christine E. Lehman ◽  
Adam Spencer ◽  
Sarah Hall ◽  
Jeremy J. P. Shaw ◽  
Julia Wulfkuhle ◽  
...  

AbstractHead and neck cancer is the sixth most common cancer worldwide with a 5-year survival of only 65%. Targeting compensatory signaling pathways may improve therapeutic responses and combat resistance. Utilizing reverse phase protein arrays (RPPA) to assess the proteome and explore mechanisms of synergistic growth inhibition in HNSCC cell lines treated with IGF1R and Src inhibitors, BMS754807 and dasatinib, respectively, we identified focal adhesion signaling as a critical node. Focal Adhesion Kinase (FAK) and Paxillin phosphorylation were decreased as early as 15 min after treatment, and treatment with a FAK inhibitor, PF-562,271, was sufficient to decrease viability in vitro. Treatment of 3D spheroids demonstrated robust cytotoxicity suggesting that the combination of BMS754807 and dasatinib is effective in multiple experimental models. Furthermore, treatment with BMS754807 and dasatinib significantly decreased cell motility, migration, and invasion in multiple HNSCC cell lines. Most strikingly, treatment with BMS754807 and dasatinib, or a FAK inhibitor alone, significantly increased cleaved-PARP in human ex-vivo HNSCC patient tissues demonstrating a potential clinical utility for targeting FAK or the combined targeting of the IGF1R with Src. This ex-vivo result further confirms FAK as a vital signaling node of this combinatorial treatment and demonstrates therapeutic potential for targeting FAK in HNSCC patients.


2021 ◽  
Vol 22 (8) ◽  
pp. 4085
Author(s):  
Hanadi Ananbeh ◽  
Petr Vodicka ◽  
Helena Kupcova Skalnikova

Huntington’s disease (HD) is a rare hereditary autosomal dominant neurodegenerative disorder, which is caused by expression of mutant huntingtin protein (mHTT) with an abnormal number of glutamine repeats in its N terminus, and characterized by intracellular mHTT aggregates (inclusions) in the brain. Exosomes are small extracellular vesicles that are secreted generally by all cell types and can be isolated from almost all body fluids such as blood, urine, saliva, and cerebrospinal fluid. Exosomes may participate in the spreading of toxic misfolded proteins across the central nervous system in neurodegenerative diseases. In HD, such propagation of mHTT was observed both in vitro and in vivo. On the other hand, exosomes might carry molecules with neuroprotective effects. In addition, due to their capability to cross blood-brain barrier, exosomes hold great potential as sources of biomarkers available from periphery or carriers of therapeutics into the central nervous system. In this review, we discuss the emerging roles of exosomes in HD pathogenesis, diagnosis, and therapy.


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