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Corenblum, M. J.

Publications and source records attributed to Corenblum, M. J..

4 recordsLinked to original sources

Bioenergetic and Protein Processing Imbalances Synergize in iPSC-Dopamine neurons from Individuals with Idiopathic Parkinsons Disease

Patient induced pluripotent stem cell (iPSC)-based models represent a powerful human system to gain insights into the etiopathology of Parkinsons disease (PD). Here, we study several iPSC-derived dopamine neuron (iPSC-DAN) lines, from individuals with idiopathic PD, which is the most common form of PD. Specifically, using iPSC-DAN differentiated for 50-55 days, we performed an in-depth analysis of different bioenergetic pathways and cellular quality control mechanisms in the cells. Our results showed wide ranging impairments in oxidative phosphorylation (OXPHOS), glycolysis and creatine kinase pathways in the PD dopamine (DA) neurons. Specifically, the PD neurons exhibited reduced oxygen consumption rates (OCR) at baseline and after challenges with mitochondrial inhibitors, as well as decreased glycolytic reserves measured via ECAR. This translated to lower OCR:ECAR ratios signifying more reliance on glycolysis vs OXPHOS in the PD cells. Moreover, a mislocalization of creatine kinase B to mitochondria was seen in the PD cells. These energetic changes synergized with the enhanced expression of mitochondrial fission proteins, disrupted mitophagy and oxidative stress. Additionally, the PD neurons contained more monomeric, phosphorylated and aggregated forms of alpha synuclein and displayed reduced viability. Ultrastructural examination through immuno-electron microscopy showed more alpha synuclein gold particles directly associated with mitochondria and packing autophagic vesicles. In essence, these data capture a web of key changes in human iPSC-DAN from idiopathic PD subjects associated with neuronal degeneration.

neuroscience↗

Acute E2/P4 loss compromises the biology and function of neurogenic niches during a vulnerable female aging period

Effects of aging on neural stem progenitor cells (NSPCs) have been studied in males, but less is known in females. Here we comparatively assess female NSPC biology, both in the subventricular zone and hippocampal dentate gyrus niches, across different ages of F344 rats (2, 6, 9 and 14 months). The rats were ovariectomized (OVX) or remained Intact at each of the aging stages, to assess the role of the female sex hormones, estradiol (E2) and progesterone (P4). Results show that while age-dependent decays become prominent at 14 months, ovariectomy-induced E2/P4 loss markedly reduces neurogenesis and associated behavioral function, earlier, at 9 months of age. Coinciding with this pattern of neurogenic decline, we also detect adaptive changes in estrogen and progesterone receptor expression, antioxidant expression, and brain E2/P4 levels. Fundamentally, these results reveal specific female time-periods, when the brain is sensitive to age and E2/P4 loss, potentially setting-up for disease susceptibility.

neuroscience↗

The 5-HT1F Receptor Agonist Lasmiditan improves Cognition and Ameliorates Associated Cortico-Hippocampal Pathology in Aging Parkinsonian Mice

While the etiopathology of Parkinsons disease (PD) is complex, mitochondrial dysfunction is established to have a central role. Thus, mitochondria have emerged as targets of therapeutic interventions aiming to slow or modify PD progression. We have previously identified serotonergic 5-HT1F receptors as novel mediators of mitochondrial biogenesis (MB) - the process of producing new mitochondria. Given this, here, we assessed the therapeutic potential of the FDA-approved 5-HT1F receptor agonist, lasmiditan, in a chronic progressive PD model (Thy1-aSyn line 61 mice). It was observed that systemic lasmiditan exhibited robust brain penetration and reversed cognitive deficits in young (4-5.5 months old) Thy1-aSyn mice (1mg/kg, every other day). Anxiety-like behavior was also improved while motor function remained unaffected. These behavioral changes were associated with enhanced MB and mitochondrial function, paired with reduced alpha-synuclein aggregation particularly in cortico-hippocampal regions. Furthermore, in older (10-11.5 months old) mice, although the effects were milder, daily lasmiditan administration increased MB and bettered cognitive abilities. In essence, these findings indicate that repurposing lasmiditan could be a potent strategy to address PD-related cognitive decline.

neuroscience↗

Parallel Neurodegenerative Phenotypes in Sporadic Parkinsons Disease Fibroblasts and Midbrain Dopamine Neurons

Understanding the mechanisms causing Parkinsons disease (PD) is vital to the development of much needed early diagnostics and therapeutics for this debilitating condition. Here, we report cellular and molecular alterations in skin fibroblasts of late-onset sporadic PD subjects, that were recapitulated in matched induced pluripotent stem cell (iPSC)-derived midbrain dopamine (DA) neurons, reprogrammed from the same fibroblasts. Specific changes in growth, morphology, reactive oxygen species levels, mitochondrial function, and autophagy, were seen in both the PD fibroblasts and DA neurons, as compared to their respective controls. Additionally, significant alterations in alpha synuclein expression and electrical activity were also noted in the PD DA neurons. Interestingly, although the fibroblast and neuronal phenotypes were similar to each other, they also differed in their nature and scale. Furthermore, statistical analysis revealed novel associations between various clinical measures of the PD subjects and the different fibroblast and neuronal data. In essence, these findings encapsulate spontaneous, in-tandem, disease-related phenotypes in both sporadic PD fibroblasts and iPSC-based DA neurons, from the same patient, and generates an innovative model to investigate PD mechanisms with a view towards rational disease stratification and precision treatments.

neuroscience↗