Molecular characteristics of porcine alpha-synuclein splicing variants

eEF1A1 regulates the expression and alternative splicing of genes associated with Parkinson's disease in U251 cells

BACKGROUND

Eukaryotic elongation factor 1A1 (eEF1A1) is an RNA-binding protein that is associated with PARK2 activity in cells, suggesting a possible role in Parkinson's disease (PD).

OBJECTIVE

To clear whether eEF1A1 plays a role in PD through transcriptional or posttranscriptional regulation.

METHODS

The GSE68719 dataset was downloaded from the GEO database, and the RNA-seq data of all brain tissue autopsies were obtained from 29 PD patients and 44 neurologically normal control subjects. To inhibit eEF1A1 from being expressed in U251 cells, siRNA was transfected into those cells, and RNA-seq high-throughput sequencing was used to determine the differentially expressed genes (DEGs) and differentially alternative splicing events (ASEs) resulting from eEF1A1 knockdown.

RESULTS

eEF1A1 was significantly overexpressed in PD brain tissue in the BA9 area. GO and KEGG enrichment analyses revealed that eEF1A1 knockdown significantly upregulated the expression of the genes CXCL10, NGF, PTX3, IL6, ST6GALNAC3, NUPR1, TNFRSF21, and CXCL2 and upregulated the alternative splicing of the genes ACOT7, DDX10, SHMT2, MYEF2, and NDUFAF5. These genes were enriched in pathways related to PD pathogenesis, such as apoptosis, inflammatory response, and mitochondrial dysfunction.

CONCLUSION

The results suggesting that eEF1A1 involved in the development of PD by regulating the differential expression and alternative splicing of genes, providing a theoretical basis for subsequent research.

Selecting the Best Animal Model of Parkinson's Disease for Your Research Purpose: Insight from in vivo PET Imaging Studies

Parkinson's disease (PD) is a debilitating neurodegenerative multisystem disorder leading to motor and non-motor symptoms in millions of individuals. Despite intense research, there is still no cure, and early disease biomarkers are lacking. Animal models of PD have been inspired by basic elements of its pathogenesis, such as dopamine dysfunction, alpha-synuclein accumulation, neuroinflammation and disruption of protein degradation, and these have been crucial for a deeper understanding of the mechanisms of pathology, the identification of biomarkers, and evaluation of novel therapies. Imaging biomarkers are non-invasive tools to assess disease progression and response to therapies; their discovery and validation have been an active field of translational research. Here, we highlight different considerations of animal models of PD that can be applied to future research, in terms of their suitability to answer different research questions. We provide the reader with important considerations of the best choice of model to use based on the disease features of each model, including issues related to different species. In addition, positron emission tomography studies conducted in PD animal models in the last 5 years are presented. With a variety of different species, interventions and genetic information, the choice of the most appropriate model to answer research questions can be daunting, especially since no single model recapitulates all aspects of this complex disorder. Appropriate animal models in conjunction with in vivo molecular imaging tools, if selected properly, can be a powerful combination for the assessment of novel therapies and developing tools for early diagnosis.

Benzo(a)pyrene exposure in utero exacerbates Parkinson's Disease (PD)-like α-synucleinopathy in A53T human alpha-synuclein transgenic mice

BACKGROUND

Previous work indicated that benzo[a]pyrene (B(a)P) exposure in utero might adversely affect neurodevelopment and cause Parkinson's Disease (PD)-like symptoms. However, the effect of utero exposure to B(a)P on PD-like α-synucleinopathy and the mechanism under are unclear.

OBJECTIVE

The A53T human alpha-synuclein (α-syn) transgenic mice (M83^+/-) were used in this study to gain insights into the role of B(a)P exposure in utero in the onset of α-syn pathology and neuronal damage.

METHOD

Timed-pregnant M83^+/- dams were exposed to 1) corn oil (vehicle) or 2) 5 mg/kg bw/d B(a)P or 3) 20 mg/kg bw/d B(a)P at gestational day 10-17 by oral gavage and then the SNCA transcription, α-syn accumulation and aggregation, neuroinflammation and nigral dopaminergic neurodegeneration of 60-day-old pups were evaluated.

RESULT

SNCA mRNA and α-syn protein expression in the midbrain of 60 days adult mice were found to be remarkably elevated after B(a)P exposure in utero, the protein degradation capacity was injured (in 20 mg/kg dose group) and α-syn aggregation could be observed in the substantia nigra (SN); Enhanced Iba1 expression in the midbrain and microglial activation (in 20 mg/kg dose group) in the SN were also figured out; Besides, dopaminergic neurons in the SN of 60 days adult mice were significantly decreased.

CONCLUSIONS

Our findings demonstrated that B(a)P exposure in utero could exacerbate α-syn pathology and induce activation of microglia which might further lead to dopaminergic neuronal loss in the SN.