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17 pages, 1558 KiB

Open AccessArticle

Open-Label Sulforaphane Trial in FMR1 Premutation Carriers with Fragile-X-Associated Tremor and Ataxia Syndrome (FXTAS)

by Ellery Santos, Courtney Clark, Hazel Maridith B. Biag, Si Jie Tang, Kyoungmi Kim, Matthew D. Ponzini, Andrea Schneider, Cecilia Giulivi, Federica Alice Maria Montanaro, Jesse Tran-Emilia Gipe, Jacquelyn Dayton, Jamie L. Randol, Pamela J. Yao, Apostolos Manolopoulos, Dimitrios Kapogiannis, Ye Hyun Hwang, Paul Hagerman, Randi Hagerman and Flora Tassone

Cells 2023, 12(24), 2773; https://doi.org/10.3390/cells12242773 - 5 Dec 2023

Cited by 4 | Viewed by 1417

Abstract

Fragile X (FMR1) premutation is a common mutation that affects about 1 in 200 females and 1 in 450 males and can lead to the development of fragile-X-associated tremor/ataxia syndrome (FXTAS). Although there is no targeted, proven treatment for FXTAS, research suggests that [...] Read more.

Fragile X (FMR1) premutation is a common mutation that affects about 1 in 200 females and 1 in 450 males and can lead to the development of fragile-X-associated tremor/ataxia syndrome (FXTAS). Although there is no targeted, proven treatment for FXTAS, research suggests that sulforaphane, an antioxidant present in cruciferous vegetables, can enhance mitochondrial function and maintain redox balance in the dermal fibroblasts of individuals with FXTAS, potentially leading to improved cognitive function. In a 24-week open-label trial involving 15 adults aged 60–88 with FXTAS, 11 participants successfully completed the study, demonstrating the safety and tolerability of sulforaphane. Clinical outcomes and biomarkers were measured to elucidate the effects of sulforaphane. While there were nominal improvements in multiple clinical measures, they were not significantly different after correction for multiple comparisons. PBMC energetic measures showed that the level of citrate synthase was higher after sulforaphane treatment, resulting in lower ATP production. The ratio of complex I to complex II showed positive correlations with the MoCA and BDS scores. Several mitochondrial biomarkers showed increased activity and quantity and were correlated with clinical improvements. Full article

(This article belongs to the Special Issue The Molecular Basis of Fragile X Syndrome and Other FMR1-Associated Conditions)

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13 pages, 1683 KiB

Open AccessFeature PaperArticle

Exploration of SUMO2/3 Expression Levels and Autophagy Process in Fragile X-Associated Tremor/Ataxia Syndrome: Addressing Study Limitations and Insights for Future Research

by Maria Isabel Alvarez-Mora, Glòria Garrabou, Laura Molina-Porcel, Ruben Grillo-Risco, Francisco Garcia-Garcia, Tamara Barcos, Judith Cantó-Santos and Laia Rodriguez-Revenga

Cells 2023, 12(19), 2364; https://doi.org/10.3390/cells12192364 - 26 Sep 2023

Viewed by 1008

Abstract

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder that appears in adult FMR1 premutation carriers. The neuropathological hallmark of FXTAS is an intranuclear inclusion in neurons and astrocytes. Nearly 200 different proteins have been identified in FXTAS inclusions, being the small [...] Read more.

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder that appears in adult FMR1 premutation carriers. The neuropathological hallmark of FXTAS is an intranuclear inclusion in neurons and astrocytes. Nearly 200 different proteins have been identified in FXTAS inclusions, being the small ubiquitin-related modifier 2 (SUMO2), ubiquitin and p62 the most highly abundant. These proteins are components of the protein degradation machinery. This study aimed to characterize SUMO2/3 expression levels and autophagy process in human postmortem brain samples and skin fibroblast cultures from FXTAS patients. Results revealed that FXTAS postmortem brain samples are positive for SUMO2/3 conjugates and supported the idea that SUMO2/3 accumulation is involved in inclusion formation. Insights from RNA-sequencing data indicated that SUMOylation processes are significantly upregulated in FXTAS samples. In addition, the analysis of the autophagy flux showed the accumulation of p62 protein levels and autophagosomes in skin fibroblasts from FXTAS patients. Similarly, gene set analysis evidenced a significant downregulation in gene ontology terms related to autophagy in FXTAS samples. Overall, this study provides new evidence supporting the role of SUMOylation and autophagic processes in the pathogenic mechanisms underlying FXTAS. Full article

(This article belongs to the Special Issue The Molecular Basis of Fragile X Syndrome and Other FMR1-Associated Conditions)

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22 pages, 1805 KiB

Open AccessArticle

Mortality in Women across the FMR1 CGG Repeat Range: The Neuroprotective Effect of Higher Education

by Jinkuk Hong, Robert S. Dembo, Leann Smith DaWalt, Mei Wang Baker, Elizabeth Berry-Kravis and Marsha R. Mailick

Cells 2023, 12(17), 2137; https://doi.org/10.3390/cells12172137 - 24 Aug 2023

Viewed by 1062

Abstract

Higher education has been shown to have neuroprotective effects, reducing the risk of Alzheimer’s and Parkinson’s diseases, slowing the rate of age-related cognitive decline, and is associated with lower rates of early mortality. In the present study, the association between higher education, fragile [...] Read more.

Higher education has been shown to have neuroprotective effects, reducing the risk of Alzheimer’s and Parkinson’s diseases, slowing the rate of age-related cognitive decline, and is associated with lower rates of early mortality. In the present study, the association between higher education, fragile X messenger ribonucleoprotein 1 (FMR1) cytosine–guanine–guanine (CGG) repeat number, and mortality before life expectancy was investigated in a population cohort of women born in 1939. The findings revealed a significant interaction between years of higher education and CGG repeat number. Counter to the study’s hypothesis, the effects of higher education became more pronounced as the number of CGG repeats increased. There was no effect of years of higher education on early mortality for women who had 25 repeats, while each year of higher education decreased the hazard of early mortality by 8% for women who had 30 repeats. For women with 41 repeats, the hazard was decreased by 14% for each additional year of higher education. The interaction remained significant after controlling for IQ and family socioeconomic status (SES) measured during high school, as well as factors measured during adulthood (family, psychosocial, health, and financial factors). The results are interpreted in the context of differential sensitivity to the environment, a conceptualization that posits that some people are more reactive to both negative and positive environmental conditions. Expansions in CGG repeats have been shown in previous FMR1 research to manifest such a differential sensitivity pattern. Full article

(This article belongs to the Special Issue The Molecular Basis of Fragile X Syndrome and Other FMR1-Associated Conditions)

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19 pages, 2127 KiB

Open AccessArticle

Brain Metabolomics in Fragile X-Associated Tremor/Ataxia Syndrome (FXTAS)

by Maria Jimena Salcedo-Arellano, Michael D. Johnson, Yingratana A. McLennan, Ye Hyun Hwang, Pablo Juarez, Erin Lucille McBride, Adriana P. Pantoja, Blythe Durbin-Johnson, Flora Tassone, Randi J. Hagerman and Verónica Martínez-Cerdeño

Cells 2023, 12(17), 2132; https://doi.org/10.3390/cells12172132 - 23 Aug 2023

Cited by 3 | Viewed by 1507

Abstract

The course of pathophysiological mechanisms involved in fragile X-associated tremor/ataxia syndrome (FXTAS) remains largely unknown. Previous proteomics and metabolomics studies conducted in blood samples collected from FMR1 premutation carriers with FXTAS reported abnormalities in energy metabolism, and precursors of gluconeogenesis showed significant changes [...] Read more.

The course of pathophysiological mechanisms involved in fragile X-associated tremor/ataxia syndrome (FXTAS) remains largely unknown. Previous proteomics and metabolomics studies conducted in blood samples collected from FMR1 premutation carriers with FXTAS reported abnormalities in energy metabolism, and precursors of gluconeogenesis showed significant changes in plasma expression levels in FMR1 premutation carriers who developed FXTAS. We conducted an analysis of postmortem human brain tissues from 44 donors, 25 brains with FXTAS, and 19 matched controls. We quantified the metabolite relative abundance in the inferior temporal gyrus and the cerebellum using untargeted mass spectrometry (MS)-based metabolomics. We investigated how the metabolite type and abundance relate to the number of cytosine-guanine-guanine (CGG) repeats, to markers of neurodegeneration, and to the symptoms of FXTAS. A metabolomic analysis identified 191 primary metabolites, the data were log-transformed and normalized prior to the analysis, and the relative abundance was compared between the groups. The changes in the relative abundance of a set of metabolites were region-specific with some overlapping results; 22 metabolites showed alterations in the inferior temporal gyrus, while 21 showed differences in the cerebellum. The relative abundance of cytidine was decreased in the inferior temporal gyrus, and a lower abundance was found in the cases with larger CGG expansions; oleamide was significantly decreased in the cerebellum. The abundance of 11 metabolites was influenced by changes in the CGG repeat number. A histological evaluation found an association between the presence of microhemorrhages in the inferior temporal gyrus and a lower abundance of 2,5-dihydroxypyrazine. Our study identified alterations in the metabolites involved in the oxidative-stress response and bioenergetics in the brains of individuals with FXTAS. Significant changes in the abundance of cytidine and oleamide suggest their potential as biomarkers and therapeutic targets for FXTAS. Full article

(This article belongs to the Special Issue The Molecular Basis of Fragile X Syndrome and Other FMR1-Associated Conditions)

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16 pages, 2182 KiB

Open AccessArticle

Intercorrelation of Molecular Biomarkers and Clinical Phenotype Measures in Fragile X Syndrome

by Ramkumar Aishworiya, Mei-Hung Chi, Marwa Zafarullah, Guadalupe Mendoza, Matthew Dominic Ponzini, Kyoungmi Kim, Hazel Maridith Barlahan Biag, Angela John Thurman, Leonard Abbeduto, David Hessl, Jamie Leah Randol, Francois V. Bolduc, Sebastien Jacquemont, Sarah Lippé, Paul Hagerman, Randi Hagerman, Andrea Schneider and Flora Tassone

Cells 2023, 12(14), 1920; https://doi.org/10.3390/cells12141920 - 24 Jul 2023

Viewed by 1440

Abstract

This study contributes to a greater understanding of the utility of molecular biomarkers to identify clinical phenotypes of fragile X syndrome (FXS). Correlations of baseline clinical trial data (molecular measures—FMR1 mRNA, CYFIP1 mRNA, MMP9 and FMRP protein expression levels, nonverbal IQ, body [...] Read more.

This study contributes to a greater understanding of the utility of molecular biomarkers to identify clinical phenotypes of fragile X syndrome (FXS). Correlations of baseline clinical trial data (molecular measures—FMR1 mRNA, CYFIP1 mRNA, MMP9 and FMRP protein expression levels, nonverbal IQ, body mass index and weight, language level, NIH Toolbox, adaptive behavior rating, autism, and other mental health correlates) of 59 participants with FXS ages of 6–32 years are reported. FMR1 mRNA expression levels correlated positively with adaptive functioning levels, expressive language, and specific NIH Toolbox measures. The findings of a positive correlation of MMP-9 levels with obesity, CYFIP1 mRNA with mood and autistic symptoms, and FMR1 mRNA expression level with better cognitive, language, and adaptive functions indicate potential biomarkers for specific FXS phenotypes. These may be potential markers for future clinical trials for targeted treatments of FXS. Full article

(This article belongs to the Special Issue The Molecular Basis of Fragile X Syndrome and Other FMR1-Associated Conditions)

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16 pages, 4648 KiB

Open AccessArticle

A Postmortem MRI Study of Cerebrovascular Disease and Iron Content at End-Stage of Fragile X-Associated Tremor/Ataxia Syndrome

by Jun Yi Wang, Gerard J. Sonico, Maria Jimena Salcedo-Arellano, Randi J. Hagerman and Veronica Martinez-Cerdeno

Cells 2023, 12(14), 1898; https://doi.org/10.3390/cells12141898 - 20 Jul 2023

Cited by 1 | Viewed by 1046

Abstract

Brain changes at the end-stage of fragile X-associated tremor/ataxia syndrome (FXTAS) are largely unknown due to mobility impairment. We conducted a postmortem MRI study of FXTAS to quantify cerebrovascular disease, brain atrophy and iron content, and examined their relationships using principal component analysis [...] Read more.

Brain changes at the end-stage of fragile X-associated tremor/ataxia syndrome (FXTAS) are largely unknown due to mobility impairment. We conducted a postmortem MRI study of FXTAS to quantify cerebrovascular disease, brain atrophy and iron content, and examined their relationships using principal component analysis (PCA). Intracranial hemorrhage (ICH) was observed in 4/17 FXTAS cases, among which one was confirmed by histologic staining. Compared with seven control brains, FXTAS cases showed higher ratings of T2-hyperintensities (indicating cerebral small vessel disease) in the cerebellum, globus pallidus and frontoparietal white matter, and significant atrophy in the cerebellar white matter, red nucleus and dentate nucleus. PCA of FXTAS cases revealed negative associations of T2-hyperintensity ratings with anatomic volumes and iron content in the white matter, hippocampus and amygdala, that were independent from a highly correlated number of regions with ICH and iron content in subcortical nuclei. Post-hoc analysis confirmed PCA findings and further revealed increased iron content in the white matter, hippocampus and amygdala in FXTAS cases compared to controls, after adjusting for T2-hyperintensity ratings. These findings indicate that both ischemic and hemorrhagic brain damage may occur in FXTAS, with the former being marked by demyelination/iron depletion and atrophy, and the latter by ICH and iron accumulation in basal ganglia. Full article

(This article belongs to the Special Issue The Molecular Basis of Fragile X Syndrome and Other FMR1-Associated Conditions)

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15 pages, 1865 KiB

Open AccessArticle

Activation Ratio Correlates with IQ in Female Carriers of the FMR1 Premutation

by Dragana Protic, Roberta Polli, Ye Hyun Hwang, Guadalupe Mendoza, Randi Hagerman, Blythe Durbin-Johnson, Bruce E. Hayward, Karen Usdin, Alessandra Murgia and Flora Tassone

Cells 2023, 12(13), 1711; https://doi.org/10.3390/cells12131711 - 24 Jun 2023

Cited by 1 | Viewed by 1207

Abstract

Carriers of the FMR1 premutation (PM) allele are at risk of one or more clinical conditions referred to as FX premutation-associated conditions (FXPAC). Since the FMR1 gene is on the X chromosome, the activation ratio (AR) may impact the risk, age of onset, [...] Read more.

Carriers of the FMR1 premutation (PM) allele are at risk of one or more clinical conditions referred to as FX premutation-associated conditions (FXPAC). Since the FMR1 gene is on the X chromosome, the activation ratio (AR) may impact the risk, age of onset, progression, and severity of these conditions. The aim of this study was to evaluate the reliability of AR measured using different approaches and to investigate potential correlations with clinical outcomes. Molecular and clinical assessments were obtained for 30 PM female participants, and AR was assessed using both Southern blot analysis (AR-Sb) and methylation PCR (AR-mPCR). Higher ARs were associated with lower FMR1 transcript levels for any given repeat length. The higher AR-Sb was significantly associated with performance, verbal, and full-scale IQ scores, confirming previous reports. However, the AR-mPCR was not significantly associated (p > 0.05) with these measures. Similarly, the odds of depression and the number of medical conditions were correlated with higher AR-Sb but not correlated with a higher AR-mPCR. This study suggests that AR-Sb may be a more reliable measure of the AR in female carriers of PM alleles. However, further studies are warranted in a larger sample size to fully evaluate the methylation status in these participants and how it may affect the clinical phenotype. Full article

(This article belongs to the Special Issue The Molecular Basis of Fragile X Syndrome and Other FMR1-Associated Conditions)

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Review

Jump to: Research

69 pages, 4604 KiB

Open AccessReview

Insight and Recommendations for Fragile X-Premutation-Associated Conditions from the Fifth International Conference on FMR1 Premutation

by Flora Tassone, Dragana Protic, Emily Graves Allen, Alison D. Archibald, Anna Baud, Ted W. Brown, Dejan B. Budimirovic, Jonathan Cohen, Brett Dufour, Rachel Eiges, Nicola Elvassore, Lidia V. Gabis, Samantha J. Grudzien, Deborah A. Hall, David Hessl, Abigail Hogan, Jessica Ezzell Hunter, Peng Jin, Poonnada Jiraanont, Jessica Klusek, R. Frank Kooy, Claudine M. Kraan, Cecilia Laterza, Andrea Lee, Karen Lipworth, Molly Losh, Danuta Loesch, Reymundo Lozano, Marsha R. Mailick, Apostolos Manolopoulos, Veronica Martinez-Cerdeno, Yingratana McLennan, Robert M. Miller, Federica Alice Maria Montanaro, Matthew W. Mosconi, Sarah Nelson Potter, Melissa Raspa, Susan M. Rivera, Katharine Shelly, Peter K. Todd, Katarzyna Tutak, Jun Yi Wang, Anne Wheeler, Tri Indah Winarni, Marwa Zafarullah and Randi J. Hagerman Show full author list Hide full author list

Cells 2023, 12(18), 2330; https://doi.org/10.3390/cells12182330 - 21 Sep 2023

Cited by 11 | Viewed by 5450

Abstract

The premutation of the fragile X messenger ribonucleoprotein 1 (FMR1) gene is characterized by an expansion of the CGG trinucleotide repeats (55 to 200 CGGs) in the 5’ untranslated region and increased levels of FMR1 mRNA. Molecular mechanisms leading to fragile [...] Read more.

The premutation of the fragile X messenger ribonucleoprotein 1 (FMR1) gene is characterized by an expansion of the CGG trinucleotide repeats (55 to 200 CGGs) in the 5’ untranslated region and increased levels of FMR1 mRNA. Molecular mechanisms leading to fragile X-premutation-associated conditions (FXPAC) include cotranscriptional R-loop formations, FMR1 mRNA toxicity through both RNA gelation into nuclear foci and sequestration of various CGG-repeat-binding proteins, and the repeat-associated non-AUG (RAN)-initiated translation of potentially toxic proteins. Such molecular mechanisms contribute to subsequent consequences, including mitochondrial dysfunction and neuronal death. Clinically, premutation carriers may exhibit a wide range of symptoms and phenotypes. Any of the problems associated with the premutation can appropriately be called FXPAC. Fragile X-associated tremor/ataxia syndrome (FXTAS), fragile X-associated primary ovarian insufficiency (FXPOI), and fragile X-associated neuropsychiatric disorders (FXAND) can fall under FXPAC. Understanding the molecular and clinical aspects of the premutation of the FMR1 gene is crucial for the accurate diagnosis, genetic counseling, and appropriate management of affected individuals and families. This paper summarizes all the known problems associated with the premutation and documents the presentations and discussions that occurred at the International Premutation Conference, which took place in New Zealand in 2023. Full article

(This article belongs to the Special Issue The Molecular Basis of Fragile X Syndrome and Other FMR1-Associated Conditions)

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