Premium
Differential Gene Expression Analysis of Brain Tissue RNA From Mucolipidosis IV Knockout Mice
Author(s) -
Chacon Jonathan,
Rosas Lauren,
Cuajungco Math P.
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2018.32.1_supplement.788.7
Subject(s) - biology , gene , gene expression , transcriptome , gene knockdown , microbiology and biotechnology , zinc finger , rna , gene expression profiling , transmembrane protein , genetics , transcription factor , receptor
Mucolipidosis IV (MLIV) is an autosomal recessive disorder that is characterized by progressive neuronal and retinal degeneration. MLIV is caused by loss of function mutations in the human Mucolipin‐1 ( MCOLN1 ) gene, whose protein product, Transient Receptor Potential Mucolipin‐1 (TRPML1), serves as a lysosomal non‐selective cation channel. We have previously reported abnormal zinc levels in MLIV patient fibroblasts, human MCOLN1 ‐knockdown cells, and Mcoln1 ‐knockout (KO) mouse brain tissues. Collectively, these observations suggest that the loss of cellular zinc homeostasis may play an underlying role in MLIV pathogenesis. To investigate whether these irregularities are reflected in the gene expression patterns of zinc buffering and transport proteins, we performed RNA sequencing (RNA‐seq) to analyze the brain transcriptome of three Mcoln1 KO mice and three wild‐type (WT) littermate controls. Gene ontology data revealed significant differential gene expression in the category of “Zinc Ion Transmembrane Transporter Activity.” Gene cluster analyses of zinc transport and zinc buffering genes revealed a distinct reduction in brain transcript levels of solute carrier 30a3 ( Slc30a3 ; also known as the efflux zinc transporter, ZnT3 ) and transmembrane ( Tmem )‐163 genes in KO mice, both of which facilitate zinc transport within neuronal synaptic vesicles. Comparison of RNA‐seq data between individual assembly and combined assembly of KO and WT sequencing reads showed distinct transcript‐level variability that could be explained by inter‐subject differences. Validation using real‐time quantitative polymerase chain reaction (qPCR) confirmed this effect. Nevertheless, both RNA‐seq and qPCR results consistently showed a decrease in ZnT3 transcript levels in KO mice compared to WT littermate control mice. These data imply that abnormal ZnT3 expression could be a mitigating factor for the observed zinc dyshomeostasis in MLIV cells. Overall, our findings suggest that the loss of human TRPML1 protein function perturbs the expression of specific genes necessary for intracellular zinc homeostasis. Future studies will investigate whether the reduction of ZnT3 transcript levels also reflect decreased protein levels in brain tissues of MLIV KO versus control mice. Support or Funding Information This work was funded by NIH R15 NS101594 and NIH R25 MD010397. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .