Biology subjects

Gomez-Pastor, R.

Publications and source records attributed to Gomez-Pastor, R..

9 recordsLinked to original sources

bioRxiv2026

HSF1 controls transcriptional programs that establish thalamostriatal shaft synaptic architecture and preserve cognitive flexibility

Cognitive flexibility (CF) declines during aging and is further impaired in neurodegenerative diseases such as Huntingtons disease (HD), yet the molecular mechanisms underlying these deficits remain poorly understood. Thalamostriatal (T-S) synapses are critical for CF, and we previously identified Heat Shock Factor 1 (HSF1) as a regulator of T-S density in HD. However, how HSF1 regulates T-S synapses and whether it modulates cognitive flexibility (CF) remained unclear. Here, we combined HSF1 ChIP-seq, transcriptomics, synapto-proteomics, targeted genetic manipulations and behavioral analyses to study how HSF1 regulates T-S synapses and CF. We found HSF1 directly controls a transcriptional program governing postsynaptic architecture and actin cytoskeletal dynamics, which are disrupted in aging and HD. Loss of HSF1 drives selective destabilization of actin patches at T-S shaft synapses and impaired CF decline. Our results underscore a novel function for HSF1 in the regulation of striatal neural circuits with essential implications in the neurobiology of cognitive flexibility.

neuroscience↗

bioRxiv2025

Striatal pathology in Spinocerebellar Ataxia Type 1 mice: A comparative study with Huntingtons disease

Spinocerebellar ataxia type 1 (SCA1) and Huntingtons disease (HD), are motor diseases caused by CAG expansions in ATXN1 and HTT, where SCA1 shows prominent cerebellar neurodegeneration and HD shows prominent striatal neurodegeneration, particularly in the Medium Spiny Neurons (MSNs). Since human and mouse studies demonstrate progressive striatal vulnerability in SCA1, we examined age-dependent molecular, cellular and functional striatal attributes in SCA1 (f-ATXN1146Q/2Q) knockin mice, by assessing RNA-sequencing, immunohistochemistry and electrophysiology. Striatal mRNAs are downregulated in SCA1 mice, many in common with HD mice, and specificity in MSNs is supported by the rescue of transcriptomic dysregulation with deletion of mutant Ataxin1 from MSNs. Immunohistochemistry assessed dopamine receptor 1 (D1R) and 2 (D2R) expression in indirect and direct MSNs. In HD mice (HttQ175/Q7), expression of both D1R and D2R proteins in MSNs decreased with age in parallel with their RNA levels. In the SCA1 mouse striatum, D1R protein expression decreased with age as seen in murine HD striatum. In contrast, while D2R protein level was decreased similar to D1R protein at 5-weeks of age, by 40-weeks expression of D2R protein recovered to levels recorded in WT mice. Electrophysiological assessment showed a reduction of excitatory synaptic transmission in SCA1 mouse MSNs, indicating functional deficits early in disease. In contrast to cerebellar and many other aspects of SCA1 pathology known to depend on proper nuclear localization of ATXN1 with an expanded polyglutamine, mutating ATXN1s nuclear localization failed to correct striatal MSN RNA and protein downregulations, indicating a difference in how ATXN1 exerts its pathological effects between the cerebellum and the striatum. Together, these data provide a molecular and cellular basis of striatal pathology in SCA1.

neuroscience↗

bioRxiv2025

Silmitasertib, an FDA-designated orphan CK2 Inhibitor, ameliorates neuropathology and motor dysfunction in a Huntington's disease mouse model

Huntingtons disease (HD) is a devastating autosomal dominant neurodegenerative disease that manifests with progressive motor, cognitive, and psychological impairments. HD is caused by a polyQ (CAG) repeat expansion in the huntingtin (HTT) gene, leading to the misfolding and aggregation of mutant HTT protein (mHTT) and the preferential degeneration of the striatum. Previously in our lab, we identified Protein Kinase CK2 as an important kinase involved in the pathophysiology of HD. Specifically, the alpha prime catalytic subunit of CK2 (CK2) is upregulated in HD, and genetic depletion of CK2 in HD mice results in improved motor behavior, decreased mutant Htt aggregation, and improved neuronal function. Silmitasertib (CX-4945) is an FDA designated orphan drug that inhibits CK2. This study aims to investigate whether CX-4945 treatment ameliorates HD pathology. We treated prodromal and late symptomatic HD mice, and used a variety of immunohistochemical, biochemical, physiological and behavioral approaches. We found that CX-4945 presented benefits in the amelioration of HD pathophysiology in both treated groups. Importantly, we found CX-4945 decreased mHtt aggregation, increased DARPP-32 expression and excitatory synapse density, restored homeostatic astrocyte phenotypes and ameliorated neuroinflammation and microgliosis, altogether resulting in improved motor behavior. These results support CX-4945 as a strong candidate for a targeted therapy to treat HD.

neuroscience↗

bioRxiv2025

Protein kinase CK2 alpha prime as a dual modulator of immune signaling and synaptic dysfunction in Tauopathy

Tauopathies are a group of neurodegenerative diseases characterized by tau accumulation, neuroinflammation, and synaptic dysfunction, yet effective treatments remain elusive. Protein Kinase CK2 has been previously associated with different aspects of tau pathology but genetic evidence for the contribution of CK2 to tauopathy remained lacking. Here, we show CK2, one of the two catalytic subunits of CK2, as a novel regulator of tau-mediated neurodegeneration. We found that CK2 expression is elevated in postmortem brains of dementia patients and in the hippocampus of PS19 tauopathy mice, especially in neurons and microglia. Using genetic haploinsufficiency in PS19 mice, we demonstrated that reduced CK2 levels significantly decrease phosphorylated tau and total tau burden in the hippocampus and cortex. CK2 depletion also attenuated microglial activation, pro-inflammatory cytokine production, and microglia synaptic engulfment, enhanced synaptic gene expression, synaptic density, and LTP. Importantly, CK2 depletion rescued cognitive deficits assessed in the Barnes maze. These effects appear to be mediated through both neuronal and glial functions and may involve CK2-dependent modulation of tau-associated phosphorylation and neuroinflammatory and immune signaling pathways. One Sentence summaryThis study highlights CK2 as a key node at the intersection of tau pathology, synaptic dysfunction, and neuroimmune signaling.

neuroscience↗

bioRxiv2024

Enhanced Hippocampal Spare Capacity in Q175DN Mice Despite Elevated mHTT Aggregation

BackgroundHuntingtons disease (HD) is a neurodegenerative disease resulting in devastating motor, cognitive, and psychiatric deficits. The striatum is a brain region that controls movement and some forms of cognition and is most significantly impacted in HD. However, despite well-documented deficits in learning and memory in HD, knowledge of the potential implication of other brain regions such as the hippocampus remains limited. ObjectiveHere, we study the comparative impact of enhanced mHTT aggregation and neuropathology in the striatum and hippocampus of two HD mouse models. MethodsWe utilized the zQ175 as a control HD mouse model and the Q175DN mice lacking the PGK-Neomycin cassette generated in house. We performed a comparative characterization of the neuropathology between zQ175 and Q175DN mice in the striatum and the hippocampus by assessing HTT aggregation, neuronal and glial pathology, chaperone expression, and synaptic density. ResultsWe showed that Q175DN mice presented enhanced mHTT aggregation in both striatum and hippocampus compared to zQ175. Striatal neurons showed a greater susceptibility to enhanced accumulation of mHTT than hippocampal neurons in Q175DN despite high levels of mHTT in both regions. Contrary to the pathology seen in the striatum, Q175DN hippocampus presented enhanced spare capacity showing increased synaptic density, decreased Iba1+ microglia density and enhanced HSF1 levels in specific subregions of the hippocampus compared to zQ175. ConclusionsQ175DN mice are a valuable tool to understand the fundamental susceptibility differences to mHTT toxicity between striatal neurons and other neuronal subtypes. Furthermore, our findings also suggest that cognitive deficits observed in HD animals might arise from either striatum dysfunction or other regions involved in cognitive processes but not from hippocampal degeneration.

neuroscience↗

bioRxiv2024

Identification of CK2α' selective inhibitors by the screening of an allosteric-kinase-inhibitor-like compound library

Protein Kinase CK2 is a holoenzyme composed of two regulatory subunits (CK2{beta}) and two catalytic subunits (CK2 and CK2). CK2 controls several cellular processes including proliferation, inflammation, and cell death. However, CK2 and CK2 possess different expression patterns and substrates and therefore impact each of these processes differently. Elevated CK2 participates in the development of cancer, while increased CK2 has been associated with neurodegeneration, especially Huntingtons disease (HD). HD is a fatal disease for which no effective therapies are available. Genetic deletion of CK2 in HD mouse models has ameliorated neurodegeneration. Therefore, pharmacological inhibition of CK2 presents a promising therapeutic strategy for treating HD. However, current CK2 inhibitors are unable to discriminate between CK2 and CK2 due to their high structural homology, especially in the targeted ATP binding site. Using computational analyses, we found a potential Type IV ("D" pocket) allosteric site on CK2 that contained different residues than CK2 and was distal from the ATP binding pocket featured in both kinases. With this potential allosteric site in mind, we screened a commercial library containing [~]29,000 allosteric-kinase-inhibitor-like compounds using a CK2 activity-dependent ADP-GloTM Kinase assay. Obtained hits were counter-screened against CK2 revealing two CK2 selective compounds. These two compounds might serve as the basis for further medicinal chemistry optimization for the potential treatment of HD.

biochemistry↗

bioRxiv2021

Striatal compartmentalization and clustering of different subtypes of astrocytes is altered in the zQ175 Huntington's disease mouse model

Huntingtons disease (HD) is a devastating neurodegenerative disease that primarily affects the striatum, a brain region that controls movement and some forms of cognition. Dysfunction and loss of medium spiny neurons of the striatum is accompanied by astrogliosis (increased astrocyte density and pathology). For decades, astrocytes were considered a homogeneous cell type, but recent transcriptomic analyses revealed astrocytes are a heterogeneous population classified into multiple subtypes depending on the expression of different gene markers. Here, we studied whether three different striatal astrocyte subtypes expressing glutamine synthetase (GS), glial fibrillary acidic protein (GFAP), or S100 calcium-binding protein B (S100B) are differentially altered in HD. We conducted a comparative immunofluorescence analysis in the striatum of WT and the heterozygous zQ175 HD mouse model and found that the expression and abundance of GFAP+ and S100B+ astrocytes increased in zQ175 mice, while GS+ astrocytes showed no alteration. We then explored whether there was a differential spatial distribution of any of these subtypes within the striatum. We developed a systematic brain compartmentalization approach and found that while GS+ and S100B+ astrocytes were more homogeneously distributed throughout the striatum in zQ175 mice, GFAP+ astrocytes preferentially accumulated in the dorsomedial and dorsolateral striatum, which are regions associated with goal-directed and habitual behaviors. Additionally, GFAP+ astrocytes in zQ175 mice showed increased clustering, a parameter that indicates increased proximity and that is associated with localized inflammation and/or neurodegeneration. Our data suggest a differential susceptibility in both increased density and striatal compartmentalization of different subtypes of astrocytes in zQ175. These results highlight new potential implications for our understanding of astrocyte pathology in HD.

neuroscience↗

bioRxiv2021

In vivo MR spectroscopy reflects synapse density in a Huntington's disease mouse model

Striatal medium spiny neurons are highly susceptible in Huntingtons disease (HD), resulting in progressive synaptic perturbations that lead to neuronal dysfunction and death. Non-invasive imaging techniques, such as proton magnetic resonance spectroscopy (1H-MRS), are used in HD mouse models and patients with HD to monitor neurochemical changes associated with neuronal health. However, the association between brain neurochemical alterations and synaptic dysregulation is unknown, limiting our ability to monitor potential treatments that may affect synapse function. We conducted in vivo longitudinal 1H-MRS in the striatum followed by ex-vivo analyses of excitatory synapse density of two synaptic circuits disrupted in HD, thalamo-striatal (T-S) and cortico-striatal (C-S) pathways, to assess the relationship between neurochemical alterations and changes in synapse density. We used the zQ175(Tg/0) HD mouse model as well as zQ175 mice lacking one allele of CK2(zQ175(Tg/0):CK2(+/-)), a kinase previously shown to regulate synapse function in HD. Longitudinal analyses of excitatory synapse density showed early and sustained reduction in T-S synapses in zQ175 mice, preceding C-S synapse depletion, which was rescued in zQ175:CK2(+/-). Changes in T-S and C-S synapses were accompanied by progressive alterations in numerous neurochemicals between WT and HD mice. Linear regression analyses showed C-S synapse number positively correlated with 1H-MRS-measured levels of GABA while T-S synapse number positively correlated with levels of alanine, phosphoethanolamine and lactate, and negatively correlated with total creatine levels. These associations suggest that these neurochemical concentrations measured by 1H-MRS may facilitate monitoring circuit-specific synaptic dysfunction in the zQ175 mouse model and in other HD pre-clinical studies. Significance StatementThe pathogenic events of many neurodegenerative diseases including HD are triggered by reductions in number of synapses. Therefore, in vivo measures that reflect synapse number represent a powerful tool to monitor synaptic changes in numerous brain disorders. In this study, we showed that non-invasive in vivo 1H-MRS reflects excitatory synapse number in the striatum of the zQ175 mouse model of HD. The combination of longitudinal 1H-MRS and immunofluorescence synapse detection revealed that distinct neurochemical levels significantly correlated with different striatal glutamatergic synaptic input pathways, suggesting that 1H-MRS could distinguish circuit-dependent synapse changes in HD. These results provide potential neurochemical biomarkers to monitor synaptic changes in future pre-clinical trials with HD models.

neuroscience↗

bioRxiv2020

Protein kinase CK2 alpha prime and alpha-synuclein constitute a key regulatory pathway in Huntington's disease

BackgroundHuntingtons Disease (HD) is a neurodegenerative disorder caused by a CAG trinucleotide repeat expansion in the HTT gene for which no therapies are available. This mutation causes HTT protein misfolding and aggregation, preferentially affecting medium spiny neurons (MSNs) of the basal ganglia. Transcriptional perturbations in synaptic genes and neuroinflammation are key processes that precede MSN dysfunction and motor symptom onset. Understanding the interplay between these processes is crucial to develop effective therapeutic strategies to treat HD. We investigated whether protein kinase CK2, a kinase upregulated in MSNs in HD and previously associated with Parkinsons disease (PD), participates in the regulation of neuroinflammation and synaptic function during HD progression. MethodsWe used the heterozygous knock-in zQ175 HD mouse model and compared that to zQ175 mice lacking one allele of CK2. We performed neuropathological analyses using immunohistochemistry, cytokine proteome profiling, RNA-seq analyses in the striatum, electrophysiological recordings, and behavioral analyses. We also used the murine immortalized striatal cell lines STHdhQ7 and STHdhQ111 and studied the expression of various synaptic genes dysregulated by CK2. ResultsWe showed that CK2 haploinsufficiency in zQ175 mice ameliorated neuroinflammation, HTT aggregation, transcriptional alterations, excitatory synaptic transmission, and motor coordination deficits. RNA-seq analyses also revealed a connection between -syn, a protein associated with PD, and the transcriptional perturbations mediated by CK2 in HD. We also found increased -syn serine 129 phosphorylation (pS129--syn), a post-translational modification linked to -synucleinopathy, in the nuclei of MSNs in zQ175 mice and in patients with HD. Levels of pS129--syn were ameliorated in zQ175 lacking one allele of CK2. ConclusionsOur data demonstrated that CK2 contributes to transcriptional dysregulation of synaptic genes and neuroinflammation in zQ175 mice and its depletion improved several HD-like phenotypes in this mouse model. These effects were related to increased phosphorylation of S129--syn in the striatum of HD mice, suggesting that CK2 contributes to worsening HD by mediating synucleinopathy. Our study highlights a possible convergent mechanism of neurodegeneration between HD and PD and suggests targeting CK2 as a potential therapeutic strategy to ameliorate synaptic dysfunction in HD as well as other neurodegenerative diseases.

neuroscience↗