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Updated: Aug 7, 2026
Determining Genome-wide Transcript Decay Rates in Proliferating and Quiescent Human Fibroblasts
Published on: January 2, 2018
Gene expression profiling in vLINCL CLN6-deficient fibroblasts: Insights into pathobiology
C A F Teixeira1, S Lin, M Mangas
1Unidade de Enzimologia, Instituto de Genética Médica Jacinto Magalhães, Porto, Portugal.
Abstract:
The CLN6 vLINCL is caused by molecular defects in CLN6 gene coding for an ER resident transmembrane protein whose function is unknown. In the present study gene expression profiling of CLN6-deficient fibroblasts using cDNA microarray was undertaken in order to provide novel insights into the molecular mechanisms underlying this neurodegenerative fatal disease. Data were validated by qRT-PCR. Statistically significant alterations of expression were observed for 12 transcripts. The two most overexpressed genes, versican and tissue factor pathway inhibitor 2, are related to extracellular matrix (ECM), predicting changes in ECM-related proteins in CLN6-deficient cells. Transcript profiling also suggested alterations in signal transduction pathways, apoptosis and the immune/inflammatory response. Up-regulated genes related to steroidogenesis or signalling, and the relationship between cholesterol dynamics and glycosphingolipid sorting, led to investigation of free cholesterol and gangliosides in CLN6-deficient fibroblasts. Cholesterol accumulation in lysosomes suggests a homeostasis block as a result of CLN6p deficiency. The cholesterol imbalance may affect structure/function of caveolae and lipid rafts, disrupting signalling transduction pathways and sorting cell mechanisms. Alterations in protein/lipid intracellular trafficking would affect the composition and function of endocytic compartments, including lysosomes. Dysfunctional endosomal/lysosomal vesicles may act as one of the triggers for apoptosis and cell death, and for a secondary protective inflammatory response. In conclusion, the data reported provide novel clues into molecular pathophysiological mechanisms of CLN6-deficiency, and may also help in developing disease biomarkers and therapies for this and other neurodegenerative diseases.
Insights
Molecular defects in the CLN6 gene cause a fatal neurodegenerative disease. This study reveals cholesterol accumulation and altered extracellular matrix proteins in affected cells, offering new therapeutic targets.
Area of Science:
- Cell Biology
- Neuroscience
- Genetics
Background:
- Neuronal ceroid lipofuscinosis (NCL) encompasses fatal neurodegenerative diseases.
- The CLN6 variant of NCL results from mutations in the CLN6 gene, encoding an endoplasmic reticulum (ER) transmembrane protein of unknown function.
- Understanding the molecular basis of CLN6 deficiency is crucial for developing effective therapies.
Purpose of the Study:
- To investigate the molecular mechanisms underlying CLN6-related neuronal ceroid lipofuscinosis (vLINCL).
- To identify novel molecular pathways and potential therapeutic targets by analyzing gene expression changes in CLN6-deficient cells.
Main Methods:
- Gene expression profiling of CLN6-deficient fibroblasts using cDNA microarray.
- Validation of key gene expression changes using quantitative real-time PCR (qRT-PCR).
- Biochemical analysis of free cholesterol and gangliosides in CLN6-deficient fibroblasts.
Main Results:
- Identified 12 statistically significant transcript alterations in CLN6-deficient fibroblasts.
- Observed overexpression of versican and tissue factor pathway inhibitor 2, indicating extracellular matrix (ECM) remodeling.
- Detected cholesterol accumulation in lysosomes, suggesting impaired cholesterol homeostasis and potential disruption of signaling pathways and intracellular trafficking.
- Evidence of altered apoptosis and immune/inflammatory responses.
Conclusions:
- CLN6 deficiency leads to significant alterations in ECM composition, cholesterol homeostasis, and intracellular trafficking pathways.
- Cholesterol accumulation and dysfunctional endosomal-lysosomal vesicles may contribute to apoptosis and inflammation in CLN6-related vLINCL.
- These findings provide novel insights into the pathophysiology of CLN6 deficiency and suggest potential biomarkers and therapeutic strategies for neurodegenerative diseases.
