Biology subjects

Rosh, I.

Publications and source records attributed to Rosh, I..

5 recordsLinked to original sources

bioRxiv2023

Synaptic dysfunction and dysregulation of extracellular matrix-related genes in dopaminergic neurons derived from Parkinson's disease sporadic patients and with GBA1 mutations

Parkinsons disease (PD) is a neurodegenerative disease with both genetic and sporadic origins. In this study, we investigated the electrophysiological properties, synaptic activity, and gene expression differences in dopaminergic (DA) neurons derived from induced pluripotent stem cells (iPSCs) of healthy controls, sporadic PD (sPD) patients, and PD patients with GBA1 mutations. Our results demonstrate reduced sodium currents and synaptic activity in DA neurons derived from PD patients with GBA1 mutations, suggesting a potential contribution to PD pathophysiology. We also observed distinct electrophysiological alterations in sPD DA neurons that were dependent on the age of disease onset. RNA sequencing analysis revealed unique dysregulated pathways in early and late-onset sPD neurons, further supporting the notion that molecular mechanisms driving PD may be different between PD patients. In agreement with our previous reports, ECM and focal adhesion genes were the top dysregulated pathways in DA neurons from sPD patients and from patients with GBA1 mutations. Overall, this study gives further confirmation that the convergent functional phenotypes of DA neurons derived from PD patients are synaptic abnormalities and at the transcriptome level, ECM and focal adhesion pathways are highly involved in PD pathology across multiple PD-associated mutations as well as sPD.

neuroscience↗

bioRxiv2022

Upregulated extracellular matrix-related genes and impaired synaptic activity in dopaminergic and hippocampal neurons derived from Parkinson's disease patients with PINK1 and PARK2 mutations

Parkinsons disease (PD) is the second most prevalent neurodegenerative disease. Primary symptoms of PD arise with the loss of dopaminergic (DA) neurons in the Substantia Nigra Pars Compacta, but it affects the hippocampus and cortex also, usually in its later stage. Approximately 15% of PD cases familial with a genetic mutation. Two of the most associated genes with autosomal recessive (AR) early-onset familial PD are PINK1 and PARK2. There is a need for in-vitro studies of these genetic mutations in order to understand the neurophysiological changes in patients neurons that may contribute to neurodegeneration. In this work, we generated and differentiated DA and hippocampal neurons from iPSCs derived from two patients with a double mutation in their PINK1 and PARK2 (one homozygous and one heterozygous) genes and assessed their neurophysiology compared to two healthy controls. We showed that the synaptic activity of PD neurons generated from patients with the PINK1 and PARK2 mutations is impaired in the hippocampus and dopaminergic neurons. Mutant dopaminergic neurons had enhanced excitatory post-synaptic activity. In addition, DA neurons with the homozygous mutation of PINK1 exhibited more pronounced electrophysiological differences compared to the control neurons. Signaling network analysis of RNA sequencing results revealed that Focal adhesion and ECM receptor pathway were the top 2 upregulated pathways in the mutant PD neurons. These phenotypes are reversed to PD phenotypes of other mutations, suggesting that the interaction of the two mutations may yield different mechanisms of PD.

neuroscience↗

bioRxiv2022

Early maturation and hyperexcitability is a shared phenotype of cortical neurons derived from different ASD-causing mutations

Autism Spectrum Disorder (ASD) is characterized mainly by social and sensory-motor abnormal and repetitive behavior patterns. Over hundreds of genes and thousands of genetic variants were reported to be highly penetrant and causative of ASD. Many of these mutations cause comorbidities such as epilepsy and intellectual disabilities (ID). In this study, we measured cortical neurons derived from induced pluripotent stem cells (iPSCs) of patients with four mutations in the genes GRIN2B, SHANK3, UBTF, as well as chromosomal duplication in the 7q11.23 region and compared them to neurons derived from a first-degree relative without the mutation. Using a whole-cell patch-clamp, we observed that the mutant cortical neurons demonstrated hyperexcitability and early maturation compared to control lines. These changes were characterized by increased sodium currents, increased amplitude and rate of excitatory postsynaptic currents (EPSCs), and more evoked action potentials in response to current stimulation in early-stage cell development (3-5 weeks post differentiation). These changes that appeared in all the different mutant lines, together with previously reported data, indicate that an early maturation and hyperexcitability may be a convergent phenotype of ASD cortical neurons.

neuroscience↗

bioRxiv2022

Generation and characterization of iPSC lines (UOHi001-A, UOHi002-A)From a patient with SHANK3 mutation and her healthy mother

Phelan-McDermid syndrome (PMS) is a rare genetic condition that causes global developmental disability, delayed or absent speech, and autism spectrum disorder. The loss of function of one copy of SHANK3, which codes for a scaffolding protein found in the postsynaptic density of synapses, has been identified as the main cause of PMS. We report the generation and characterization of two induced pluripotent stem cell (iPSC) lines derived from one patient with a SHANK3 mutation and the patients mother as a control. Both lines expressed pluripotency markers, differentiated into the three germ layers, retained the disease-causing mutation, and displayed normal karyotypes.

cell biology↗

bioRxiv2022

Reduced synaptic activity and dysregulated extracellular matrix pathways are common phenotypes in midbrain neurons derived from sporadic and mutation-associated Parkinson's disease patients

Several mutations that cause Parkinsons disease (PD) have been identified over the past decade. These account for 15-25% of PD cases; the rest of the cases are considered sporadic. Currently, it is accepted that PD is not a single monolithic disease but rather a constellation of diseases with some common phenotypes. While rodent models exist for some of the PD-causing mutations, research on the sporadic forms of PD is lagging due to a lack of cellular models. In our study, we differentiated PD patient-derived dopaminergic (DA) neurons from induced pluripotent stem cells (iPSCs) of several PD-causing mutations as well as from sporadic PD patients. Strikingly, we observed a common neurophysiological phenotype: Neurons derived from PD patients had a severe reduction in the rate of synaptic currents compared to those derived from healthy controls. While the relationship between mutations in genes such as the SNCA and LRRK2 and a reduction in synaptic transmission has been investigated before, here we show evidence that the pathogenesis of the synapses in neurons is a general phenotype in PD. Analysis of RNA sequencing results displayed changes in gene expression in different synaptic mechanisms as well as other affected pathways such as extracellular matrix-related pathways. Some of these dysregulated pathways are common to all PD patients (monogenic or idiopathic). Our data, therefore, shows changes that are central and convergent to PD and suggests a strong involvement of the tetra-partite synapse in PD pathophysiology.

neuroscience↗