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Mastroberardino, P. G.

Publications and source records attributed to Mastroberardino, P. G..

5 recordsLinked to original sources

RNA sequence analysis of somatic mutations in aging and Parkinson's Disease

Parkinsons Disease (PD) is an age-related neurodegenerative disorder that has been associated with increased DNA damage. To test if PD is associated with increased somatic mutations, we analyzed RNA-seq data in whole blood from 5 visits of the Parkinsons Progression Markers Initiative for clonally amplified somatic variants. Comprehensive analysis of RNA-sequencing data revealed a total of 5,927 somatic variants (2.4 variants per sample on average). Mutation frequencies were significantly elevated in PD subjects as compared to age-matched controls at the time of the last visit. This was confirmed by RNA analysis of substantia nigra. By contrast, the fraction of carriers with clonal hematopoiesis, was significantly reduced in old PD patients as compared to old healthy controls. These results indicate that while the overall mutation rate is higher in PD, specific clonally amplified mutations are protective against PD, as has been found for Alzheimers Disease.

genetics↗

Orthogonal analysis of mitochondrial function in Parkinson's disease patients

The etiopathology of Parkinsons disease has been associated with mitochondrial defects at genetic, laboratory, epidemiological, and clinical level. These converging lines of evidence suggest that mitochondrial defects are systemic and causative factors in the pathophysiology of PD, rather than being mere correlates. Understanding mitochondrial biology in PD at granular level is therefore crucial from both basic science and translational perspectives. In a recent study, we investigated mitochondrial alterations in fibroblasts obtained from PD patients assessing mitochondrial function in relation to clinical measures. Our findings demonstrated that the magnitude of mitochondrial alterations parallels disease severity. In this study, we extend these investigations to blood cells and dopamine neurons derived from induced pluripotent stem cells reprogrammed from PD patients. To overcome the inherent metabolic heterogeneity of blood cells, we focused our analyses on metabolically homogeneous, accessible, and expandable erythroblasts. Our results confirm the presence of mitochondrial anomalies in erythroblasts and induced dopamine neurons. Consistent with our previous findings in fibroblasts, we observed that mitochondrial alterations are reversible, as evidenced by enhanced mitochondrial respiration when PD erythroblasts were cultured in a galactose medium that restricts glycolysis. This observation indicates that suppression of mitochondrial respiration may constitute a protective, adaptive response in PD pathogenesis. Notably, this effect was not observed in induced dopamine neurons, suggesting their distinct bioenergetic behavior. In summary, we provide additional evidence for the involvement of mitochondria in the disease process by demonstrating mitochondrial abnormalities in additional cell types relevant to PD. These findings contribute to our understanding of PD pathophysiology and may have implications for the development of novel biomarkers and therapeutic strategies.

neuroscience↗

Reduced frequency of clonal hematopoiesis in Parkinson's disease

To test if clonal hematopoiesis of indeterminate potential (CHIP) is associated with the incidence of Parkinsons Disease (PD), we analyzed blood whole exome sequencing data from 171 healthy controls and 335 PD subjects in the Parkinsons Progression Markers Initiative. We observed an age-related increase of CHIP carriers in the healthy controls. Surprisingly, the percentage of CHIP carriers was significantly lower in old PD patients than in age-matched controls.

genetics↗

TWIST1 controls cellular senescence and energy metabolism in mesenchymal stem cells

Mesenchymal stem cells (MSC) are promising cells for regenerative medicine therapies, because they can differentiate towards multiple cell lineages. However, heterogeneity in differentiation capacity is one of the main drawbacks that limit their use clinically. Differences in the occurrence of cellular senescence and in the expression of the senescence associated secretory phenotype (SASP) in MSC populations contribute to their heterogeneity. Here, we show the involvement of TWIST1 expression in the regulation of MSC senescence, demonstrating that silencing of TWIST1 in MSCs increased the occurrence of senescence. These senescent MSCs had a SASP that was different from irradiation-induced senescent MSCs. In addition, metabolic evaluation performed by the Seahorse XF apparatus showed that both TWIST1 silencing-induced and irradiation-induced senescent MSCs had a higher oxygen consumption compared to control MSCs, while TWIST1 silencing-induced senescent MSCs had a low extracellular acidification rate compared to the irradiation-induced senescent MSCs. Overall, our data indicate how TWIST1 regulation influences senescence in human MSCs and that TWIST1 silencing-induced senescence is characterized by a specific expression of the SASP and the metabolic state.

cell biology↗

Peripheral mitochondrial function correlates with clinical severity in idiopathic Parkinson’s disease

BackgroundParkinson disease is an intractable disorder with heterogeneous clinical presentation that may reflect different underlying pathogenic mechanisms. Surrogate indicators of pathogenic processes correlating with clinical measures may assist in better patients stratification. Mitochondrial function - which is impaired in and central to PD pathogenesis - may represent one of such surrogate indicators.\n\nMethodsMitochondrial function was assessed by respirometry experiment in fibroblasts derived from idiopathic patients (n=47) in normal conditions and in experimental settings that do not permit glycolysis and therefore force energy production through mitochondrial function. Respiratory parameters and clinical measures were correlated with bivariate analysis. Machine learning based classification and regression trees were used to classify patients on the basis of biochemical and clinical measures. Effects of mitochondrial respiration on alpha-synuclein stress was assessed monitoring the protein phosphorylation in permitting versus restrictive glycolysis conditions.\n\nResultsBioenergetics properties in peripheral fibroblasts correlate with clinical measures in idiopathic patients and correlation is stronger with predominantly non-dopaminergic signs. Bioenergetics analysis under metabolic stress, in which energy is produced solely by mitochondria, shows that patients fibroblasts can augment respiration, therefore indicating that mitochondrial defects are reversible. Forcing energy production through mitochondria, however, favors alpha-synuclein stress in different cellular experimental systems. Machine learning-based classification identified different groups of patients in which increasing disease severity parallels higher mitochondrial respiration.\n\nConclusionSuppression of mitochondrial activity in Parkinson disease may be an adaptive strategy to cope with concomitant pathogenic factors. Moreover, mitochondrial measures are potential biomarkers to follow disease progression.

neuroscience↗