Cystamine and cysteamine increase brain levels of BDNF in Huntington disease via HSJ1b and transglutaminase.
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ABSTRACT:
SUBMITTER: Borrell-Pages M
PROVIDER: S-EPMC1430359 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:The catalytic activity of transglutaminase 2 (TG2), a ubiquitously expressed mammalian enzyme, is regulated by multiple post-translational mechanisms. Because elevated activity of TG2 in the extracellular matrix is associated with organ-specific diseases such as celiac disease and renal fibrosis, there is growing therapeutic interest in inhibitors of this enzyme. Cystamine, a symmetric disulfide compound, is one of the earliest reported TG2 inhibitors. Despite its widespread use as a tool compound to block TG2 activity in vitro and in vivo, its mechanism of action has remained unclear. Here, we demonstrate that cystamine irreversibly inhibits human TG2 ( kinh/ Ki = 1.2 mM-1 min-1) via a mechanism fundamentally distinct from those proposed previously. Through mass spectrometric disulfide mapping and site-directed mutagenesis, we show that cystamine promotes the formation of a physiologically relevant disulfide bond between Cys370 and Cys371 that allosterically abrogates the catalytic activity of human TG2. This discovery led us to evaluate clinically useful thiol ? disulfide oxidants for TG2 inhibitory activity. It is demonstrated that disulfiram, a relatively safe oral thiuram disulfide, is a fairly potent TG2 inhibitor ( kinh/ Ki = 8.3 mM-1 min-1) and may therefore provide a practical tool for clinically validating this emerging therapeutic target in intestinal disorders such as celiac disease.
| S-EPMC6008213 | biostudies-literature
Project description:Huntington Disease (HD) is a dominantly inherited, relentlessly progressive neurodegenerative disease. Caused by a polyglutamine expansion in the mutant huntingtin protein (mhtt), HD pathogenesis impairs function in the cerebral cortex and in medium spiny neurons of the striatum and involves transcriptional dysregulation of a number of genes. Of these genes, silencing of genes related to mitochondrial function is believed to explain metabolic dysfunction in rodent models of HD. Here we show that transglutaminase 2 (TG2), which is upregulated in HD, exacerbates transcriptional dysregulation by acting as a selective corepressor of nuclear genes. TG2 inhibition by RNA knockdown, genetic deletion, or administration of a novel irreversible, peptide-based TG2 inhibitor (ZDON) de-repressed two established regulators of mitochondrial function, PGC-1? and cytochrome c in a cell model of HD. TG2 must localize to non-coding or coding regions of these mitochondrial metabolic genes to silence their transcription. As expected, TG2 inhibition reversed the increased susceptibility of HD mouse cells and human HD myoblasts to the mitochondrial toxin, 3-nitroproprionic acid (3-NP); however, protection mediated by TG2 inhibition was not associated with improved mitochondrial bioenergetics. Indeed, an unbiased array analysis indicated that TG2 inhibition leads to normalization of not only mitochondrial genes but of nearly 40% of genes that are dysregulated in HD mouse striatal neurons, including chaperone and histone genes. Indeed, TG2 interacts directly with Histone 3 in the nucleus. Moreover, TG2 inhibition significantly attenuated photoreceptor degeneration in a Drosophila model of HD and protected mouse HD striatal neurons (YAC128) from NMDA- induced toxicity. Altogether these findings demonstrate that TG2 mediates its deleterious effects in HD by contributing to broad transcriptional dysregulation of genes representing many cellular functions. These studies define a novel HDAC-independent epigenetic strategy for treating neurodegeneration. To evaluate the effect of TG2 inhibition (treatment with ZDON, Boc-DON, CystamineA, and Control) in striatal cell lines from a transgenic model of Huntington disease (Q111) vs. control (Q7). One sample (WT.boc.3, 4068264015_G) failed the QC test and was excluded from further analyses.
2010-04-08 | E-GEOD-21237 | biostudies-arrayexpress
Project description:Huntington Disease (HD) is a dominantly inherited, relentlessly progressive neurodegenerative disease. Caused by a polyglutamine expansion in the mutant huntingtin protein (mhtt), HD pathogenesis impairs function in the cerebral cortex and in medium spiny neurons of the striatum and involves transcriptional dysregulation of a number of genes. Of these genes, silencing of genes related to mitochondrial function is believed to explain metabolic dysfunction in rodent models of HD. Here we show that transglutaminase 2 (TG2), which is upregulated in HD, exacerbates transcriptional dysregulation by acting as a selective corepressor of nuclear genes. TG2 inhibition by RNA knockdown, genetic deletion, or administration of a novel irreversible, peptide-based TG2 inhibitor (ZDON) de-repressed two established regulators of mitochondrial function, PGC-1α and cytochrome c in a cell model of HD. TG2 must localize to non-coding or coding regions of these mitochondrial metabolic genes to silence their transcription. As expected, TG2 inhibition reversed the increased susceptibility of HD mouse cells and human HD myoblasts to the mitochondrial toxin, 3-nitroproprionic acid (3-NP); however, protection mediated by TG2 inhibition was not associated with improved mitochondrial bioenergetics. Indeed, an unbiased array analysis indicated that TG2 inhibition leads to normalization of not only mitochondrial genes but of nearly 40% of genes that are dysregulated in HD mouse striatal neurons, including chaperone and histone genes. Indeed, TG2 interacts directly with Histone 3 in the nucleus. Moreover, TG2 inhibition significantly attenuated photoreceptor degeneration in a Drosophila model of HD and protected mouse HD striatal neurons (YAC128) from NMDA- induced toxicity. Altogether these findings demonstrate that TG2 mediates its deleterious effects in HD by contributing to broad transcriptional dysregulation of genes representing many cellular functions. These studies define a novel HDAC-independent epigenetic strategy for treating neurodegeneration.
2010-04-08 | GSE21237 | GEO
Project description:Caused by a polyglutamine expansion in the huntingtin protein, Huntington's disease leads to striatal degeneration via the transcriptional dysregulation of a number of genes, including those involved in mitochondrial biogenesis. Here we show that transglutaminase 2, which is upregulated in HD, exacerbates transcriptional dysregulation by acting as a selective corepressor of nuclear genes; transglutaminase 2 interacts directly with histone H3 in the nucleus. In a cellular model of HD, transglutaminase inhibition de-repressed two established regulators of mitochondrial function, PGC-1alpha and cytochrome c and reversed susceptibility of human HD cells to the mitochondrial toxin, 3-nitroproprionic acid; however, protection mediated by transglutaminase inhibition was not associated with improved mitochondrial bioenergetics. A gene microarray analysis indicated that transglutaminase inhibition normalized expression of not only mitochondrial genes but also 40% of genes that are dysregulated in HD striatal neurons, including chaperone and histone genes. Moreover, transglutaminase inhibition attenuated degeneration in a Drosophila model of HD and protected mouse HD striatal neurons from excitotoxicity. Altogether these findings demonstrate that selective TG inhibition broadly corrects transcriptional dysregulation in HD and defines a novel HDAC-independent epigenetic strategy for treating neurodegeneration.
| S-EPMC3068019 | biostudies-literature
Project description:Host-directed therapies are emerging as a promising tool in the curing of difficult-to-treat infections, such as those caused by drug-resistant bacteria. In this study, we aim to test the potential activity of the FDA- and EMA-approved drugs cysteamine and cystamine against Mycobacterium abscessus. In human macrophages (differentiated THP-1 cells), these drugs restricted M. abscessus growth similar to that achieved by amikacin. Here, we use the human ex vivo granuloma-like structures (GLS) model of infection with the M. abscessus rough (MAB-R) and smooth (MAB-S) variants to study the activity of new therapies against M. abscessus. We demonstrate that cysteamine and cystamine show a decrease in the number of total GLSs per well in the MAB-S and MAB-R infected human peripheral blood mononuclear cells (PBMCs). Furthermore, combined administration of cysteamine or cystamine with amikacin resulted in enhanced activity against the two M. abscessus morpho variants compared to treatment with amikacin only. Treatment with cysteamine and cystamine was more effective in reducing GLS size and bacterial load during MAB-S infection compared with MAB-R infection. Moreover, treatment with these two drugs drastically quenched the exuberant proinflammatory response triggered by the MAB-R variant. These findings showing the activity of cysteamine and cystamine against the R and S M. abscessus morphotypes support the use of these drugs as novel host-directed therapies against M. abscessus infections.
| S-EPMC9866335 | biostudies-literature
Project description:Huntington disease (HD) is a neurodegenerative disease caused by a CAG trinucleotide repeat expansion in the huntingtin (HTT) gene. Therapeutics that lower HTT have shown preclinical promise and are being evaluated in clinical trials. However, clinical assessment of brain HTT lowering presents challenges. We have reported that mutant HTT (mHTT) in the CSF of HD patients correlates with clinical measures, including disease burden as well as motor and cognitive performance. We have also shown that lowering HTT in the brains of HD mice results in correlative reduction of mHTT in the CSF, prompting the use of this measure as an exploratory marker of target engagement in clinical trials. In this study, we investigate the mechanisms of mHTT clearance from the brain in adult mice of both sexes to elucidate the significance of therapy-induced CSF mHTT changes. We demonstrate that, although neurodegeneration increases CSF mHTT concentrations, mHTT is also present in the CSF of mice in the absence of neurodegeneration. Importantly, we show that secretion of mHTT from cells in the CNS followed by glymphatic clearance from the extracellular space contributes to mHTT in the CSF. Furthermore, we observe secretion of wild type HTT from healthy control neurons, suggesting that HTT secretion is a normal process occurring in the absence of pathogenesis. Overall, our data support both passive release and active clearance of mHTT into CSF, suggesting that its treatment-induced changes may represent a combination of target engagement and preservation of neurons.SIGNIFICANCE STATEMENT: Changes in CSF mutant huntingtin (mHTT) are being used as an exploratory endpoint in HTT lowering clinical trials for the treatment of Huntington disease (HD). Recently, it was demonstrated that intrathecal administration of a HTT lowering agent leads to dose-dependent reduction of CSF mHTT in HD patients. However, little is known about how HTT, an intracellular protein, reaches the extracellular space and ultimately the CSF. Our findings that HTT enters CSF by both passive release and active secretion followed by glymphatic clearance may have significant implications for interpretation of treatment-induced changes of CSF mHTT in clinical trials for HD.
| S-EPMC7842749 | biostudies-literature
Project description:Mammalian transglutaminases (TGs) catalyze calcium-dependent irreversible posttranslational modifications of proteins and their enzymatic activities contribute to the pathogenesis of several human neurodegenerative diseases. Although different transglutaminases are found in many different tissues, the TG6 isoform is mostly expressed in the CNS. The present study was embarked on/undertaken to investigate expression, distribution and activity of transglutaminases in Huntington disease transgenic rodent models, with a focus on analyzing the involvement of TG6 in the age- and genotype-specific pathological features relating to disease progression in HD transgenic mice and a tgHD transgenic rat model using biochemical, histological and functional assays. Our results demonstrate the physical interaction between TG6 and (mutant) huntingtin by co-immunoprecipitation analysis and the contribution of its enzymatic activity for the total aggregate load in SH-SY5Y cells. In addition, we identify that TG6 expression and activity are especially abundant in the olfactory tubercle and piriform cortex, the regions displaying the highest amount of mHTT aggregates in transgenic rodent models of HD. Furthermore, mHTT aggregates were colocalized within TG6-positive cells. These findings point towards a role of TG6 in disease pathogenesis via mHTT aggregate formation.
| S-EPMC8396294 | biostudies-literature
Project description:Cysteamine is an endogenous aminothiol produced in mammalian cells as a consequence of coenzyme A metabolism through the activity of the vanin family of pantetheinase ectoenzymes. It is known to have a biological role in oxidative stress, inflammation, and cell migration. There have been several reports demonstrating anti-infective properties targeting viruses, bacteria, and even the malarial parasite. We and others have previously described broad-spectrum antimicrobial and antibiofilm activities of cysteamine. Here, we go further to demonstrate redox-dependent mechanisms of action for the compound and how its antimicrobial effects are, at least in part, due to undermining bacterial defenses against oxidative and nitrosative challenges. We demonstrate the therapeutic potentiation of antibiotic therapy against Pseudomonas aeruginosa in mouse models of infection. We also demonstrate potentiation of many different classes of antibiotics against a selection of priority antibiotic-resistant pathogens, including colistin (often considered an antibiotic of last resort), and we discuss how this endogenous antimicrobial component of innate immunity has a role in infectious disease that is beginning to be explored and is not yet fully understood.
| S-EPMC5964511 | biostudies-literature
Project description:Huntington's Disease (HD) is a devastating neurodegenerative disorder that is caused by an expanded CAG trinucleotide repeat in the Huntingtin (HTT) gene. Transcriptional dysregulation in the human HD brain has been documented but is incompletely understood. Here we present a genome-wide analysis of mRNA expression in human prefrontal cortex from 20 HD and 49 neuropathologically normal controls using next generation high-throughput sequencing. Surprisingly, 19% (5,480) of the 28,087 confidently detected genes are differentially expressed (FDR<0.05) and are predominantly up-regulated. A novel hypothesis-free geneset enrichment method that dissects large gene lists into functionally and transcriptionally related groups discovers that the differentially expressed genes are enriched for immune response, neuroinflammation, and developmental genes. Markers for all major brain cell types are observed, suggesting that HD invokes a systemic response in the brain area studied. Unexpectedly, the most strongly differentially expressed genes are a homeotic gene set (represented by Hox and other homeobox genes), that are almost exclusively expressed in HD, a profile not widely implicated in HD pathogenesis. The significance of transcriptional changes of developmental processes in the HD brain is poorly understood and warrants further investigation. The role of inflammation and the significance of non-neuronal involvement in HD pathogenesis suggest anti-inflammatory therapeutics may offer important opportunities in treating HD.
| S-EPMC4670106 | biostudies-literature
Project description:BackgroundBrain-derived neurotrophic factor is implicated in the pathophysiology of major depressive disorder and suicide. Both are partly caused by early life adversity, which reduces brain-derived neurotrophic factor protein levels. This study examines the association of brain-derived neurotrophic factor Val66Met polymorphism and brain brain-derived neurotrophic factor levels with depression and suicide. We hypothesized that both major depressive disorder and early life adversity would be associated with the Met allele and lower brain brain-derived neurotrophic factor levels. Such an association would be consistent with low brain-derived neurotrophic factor mediating the effect of early life adversity on adulthood suicide and major depressive disorder.MethodsBrain-derived neurotrophic factor Val66Met polymorphism was genotyped in postmortem brains of 37 suicide decedents and 53 nonsuicides. Additionally, brain-derived neurotrophic factor protein levels were determined by Western blot in dorsolateral prefrontal cortex (Brodmann area 9), anterior cingulate cortex (Brodmann area 24), caudal brainstem, and rostral brainstem. The relationships between these measures and major depressive disorder, death by suicide, and reported early life adversity were examined.ResultsSubjects with the Met allele had an increased risk for depression. Depressed patients also have lower brain-derived neurotrophic factor levels in anterior cingulate cortex and caudal brainstem compared with nondepressed subjects. No effect of history of suicide death or early life adversity was observed with genotype, but lower brain-derived neurotrophic factor levels in the anterior cingulate cortex were found in subjects who had been exposed to early life adversity and/or died by suicide compared with nonsuicide decedents and no reported early life adversity.ConclusionsThis study provides further evidence implicating low brain brain-derived neurotrophic factor and the brain-derived neurotrophic factor Met allele in major depression risk. Future studies should seek to determine how altered brain-derived neurotrophic factor expression contributes to depression and suicide.
| S-EPMC6007393 | biostudies-literature