SNCA A53T Human

What is the SNCA A53T mutation and how is it related to Parkinson's disease?

The SNCA A53T mutation is a point mutation in the alpha-synuclein gene where alanine is replaced by threonine at position 53. This mutation is one of five identified point mutations responsible for autosomal dominant Parkinson's disease (PD) . Alpha-synuclein (encoded by SNCA) is a major component of Lewy bodies, which are neuropathological features of PD . The A53T mutation affects the protein's structure and function, contributing to disease pathogenesis, particularly in familial forms of PD where it causes early onset of symptoms .

Which regions of the alpha-synuclein protein are most affected by the A53T mutation?

Evolutionary and structural analysis has revealed that the region encompassing amino acids 32 to 58 of the N-terminal domain of SNCA is particularly critical, both functionally and in terms of disease pathogenesis . This region is part of the N-terminal lipid-binding alpha-helix domain and harbors crucial interaction sites . The A53T mutation falls within this functionally significant region, which explains its profound impact on protein stability, conformation, and pathogenic potential .

How does the SNCA A53T mutation affect cellular lipid profiles?

Lipidomic analyses have revealed specific alterations in lipid profiles associated with the SNCA A53T mutation. Research has identified that patients with this mutation show distinct changes in specific lipid classes, particularly glycerophosphatidylcholine and triradylglycerol . These alterations are consistently observed not only in patient sera but also in cellular and animal models expressing the same mutation . The relationship between alpha-synuclein and lipids is of particular interest given that alpha-synuclein is known to interact with lipid membranes, and these interactions may be disrupted by the A53T mutation .

What human cellular models are available for studying SNCA A53T?

Several human cellular models are available for SNCA A53T research. These include:

• Homozygous models (SNCA A53T/A53T): These are iPSC-derived glutamatergic neurons with the A53T mutation in both alleles of the SNCA gene . These cells mature rapidly, display glutamatergic neuron morphology, and form structural neuronal networks within 11 days post-revival .

• Heterozygous models (SNCA A53T/WT): These contain the A53T mutation in only one allele, mimicking the genetic status of most patients with familial PD caused by this mutation . These cells are also programmed to mature rapidly and form structural neuronal networks by day 10 post-revival .

Both models are generated using opti-ox deterministic programming technology, allowing for scalable production of consistently programmed cells suitable for industrial workflows and high-throughput studies .

What animal models express the human SNCA A53T mutation?

Animal models include transgenic mice and humanized A53T SNCA knockin rats. The rat model, available through Inotiv (formerly Horizon/Envigo), contains a knockin of the A53T-mutated SNCA gene that renders the rat SNCA gene non-functional . This model expresses a humanized A53T alpha-synuclein protein that includes humanized amino acids spanning positions 53-122, without expressing endogenous rat alpha-synuclein . These models were generated using CRISPR/Cas9 genome targeting strategies and are valuable for studying the in vivo effects of the A53T mutation .

How do genetically matched controls enhance experimental design in SNCA A53T research?

Genetically matched controls are critical for isolating the specific effects of the A53T mutation. Both homozygous and heterozygous cellular models can be paired with genetically matched wild-type glutamatergic neurons that share the same genetic background but express normal alpha-synuclein . This approach allows researchers to directly investigate the effect of the alpha-synuclein mutation on cellular mechanisms and function while controlling for variation in genetic background . True comparisons between mutant and control cells provide more robust and reliable data on mutation-specific phenotypes.

What are the recommended protocols for culturing and differentiating SNCA A53T cellular models?

SNCA A53T cellular models are typically delivered in a cryopreserved format and require a two-phase process for cultivation after revival :

• Stabilization Phase: This initial 4-day period after thawing allows cells to recover and adapt to culture conditions .

• Maintenance Phase: During this subsequent period, neurons mature and develop their phenotypic characteristics .

Cells are experiment-ready as early as 2 days post-revival, with structural neuronal networks forming by days 10-11 . Specific media compositions and culture conditions should be optimized based on the particular experimental endpoints and should follow recommendations provided by the cell source to ensure optimal cell viability and phenotypic expression.

How should researchers approach lipidomic analysis of SNCA A53T models?

For comprehensive lipidomic analysis of SNCA A53T models, researchers should:

• Employ unbiased lipidomic approaches that can detect a wide range of lipid species (e.g., the study in search result #1 analyzed 530 lipid species from 34 lipid classes) .

• Use both machine learning algorithms and traditional statistics for data analysis to identify the most discriminatory lipid changes .

• Compare findings across multiple model systems (patient samples, cellular models, and animal models) to validate biological relevance .

• Focus particular attention on glycerophosphatidylcholine and triradylglycerol classes, which have shown consistent alterations in SNCA A53T contexts .

• Consider the pathogenic significance of identified lipid changes by correlating them with functional outcomes or disease progression markers .

How should researchers validate phenotypes across multiple SNCA A53T clones?

To ensure robust findings, researchers should:

• Study multiple independent clones of the specific disease model to account for clonal variation and obtain a more comprehensive understanding of mutation effects .

• Compare results between homozygous and heterozygous models to assess gene dosage effects .

• Utilize detailed characterization data and bulk RNA sequencing data to select appropriate clones for specific research questions .

• Perform parallel experiments across different clones to distinguish mutation-specific phenotypes from clone-specific artifacts .

• Consider the impact of cellular heterogeneity on disease phenotypes by analyzing cell-to-cell variation within and between clones .

This multi-clone approach increases confidence that observed phenotypes are truly related to the A53T mutation rather than artifacts of a particular genetic background or clonal derivation process.

What key phenotypes should be measured when characterizing SNCA A53T models?

Based on comprehensive characterization studies of SNCA A53T models, researchers should assess:

• Behavioral phenotypes: In animal models, these include open field tests, GI motility, beam walk performance, and fine motor kinematics. Sex-specific differences should be noted, as some studies have observed female phenotypes at 4 months and male phenotypes at 18 months .

• Biochemical markers: These include quantification of rat and human SNCA mRNA levels, as well as total, soluble, and insoluble alpha-synuclein protein levels .

• Neurochemical analysis: Measure dopamine and dopamine metabolite levels, particularly in the striatum .

• Histological assessments: Include staining for tyrosine hydroxylase, phosphorylated alpha-synuclein (pS129), total alpha-synuclein, phosphorylated tau (pTau/AT8), and glial markers (GFAP, Iba-1) in relevant brain regions .

• Peripheral markers: Include assessment of alpha-synuclein in peripheral tissues such as colon and duodenum, and banking of peripheral blood mononuclear cells for biomarker studies .

How can multi-omics approaches enhance our understanding of SNCA A53T pathogenesis?

Multi-omics approaches combine different types of high-throughput molecular analyses to provide a more comprehensive understanding of disease mechanisms:

• Integrate lipidomics with transcriptomics, proteomics, and metabolomics to create a comprehensive molecular profile of SNCA A53T models .

• Utilize bioinformatics and machine learning algorithms to identify patterns and relationships across different omics datasets that may not be apparent when analyzing each dataset in isolation .

• Apply pathway and network analyses to map how lipid alterations interact with changes in gene expression, protein levels, and metabolic profiles .

• Correlate multi-omics findings with functional and phenotypic data to establish causal relationships and identify potential therapeutic targets .

• Compare multi-omics profiles across different model systems (cellular, animal, and patient samples) to identify conserved pathogenic mechanisms .

This integrated approach can reveal novel insights into how the A53T mutation affects multiple cellular processes and identify potential intervention points for therapeutic development.

What is the evolutionary significance of the region containing the A53T mutation?

The region containing the A53T mutation (amino acids 32-58) has acquired critical functional significance through the course of sarcopterygian evolutionary history . Evolutionary analysis has revealed:

• Strong purifying selection acting on the entire synuclein family, indicating functional conservation .

• Epistatic influence of lineage-specific substitutions that have shaped the functional importance of this region .

• The critical nature of this region not only for evolutionary conservation but also for protein stability and proper conformation .

• The presence of crucial interaction sites within this region that mediate alpha-synuclein's biological functions and pathological interactions .

Understanding the evolutionary context of this region provides insights into why mutations in this specific location have such profound effects on protein function and disease pathogenesis.

How do lipid alterations in SNCA A53T models compare to other genetic forms of Parkinson's disease?

While the search results primarily focus on SNCA A53T, researchers should consider how lipid alterations in this model compare to other genetic forms of PD:

• Conduct comparative lipidomic analyses across different genetic PD models, including other SNCA mutations (E46K, H50Q, G51D, A53E) and mutations in genes like LRRK2, GBA, PINK1, and PRKN .

• Identify common and distinct lipid alterations across different genetic forms to distinguish general PD-associated lipid changes from mutation-specific effects .

• Correlate specific lipid alterations with particular aspects of disease phenotypes (e.g., onset age, progression rate, symptom profile) to understand their clinical relevance .

• Investigate whether different genetic forms of PD converge on common lipid-related pathways or represent distinct pathogenic mechanisms with unique lipid signatures .

• Explore potential gene-lipid interactions that may explain varying disease penetrance and expressivity among carriers of the same mutation .

This comparative approach can help identify both shared pathogenic mechanisms and unique aspects of SNCA A53T-related neurodegeneration, potentially informing more targeted therapeutic strategies.