GSE131104
Accumulation of progerin affects the symmetry of cell division and is associated with impaired Wnt signaling and the mislocalization of nuclear envelope proteins [RNA-Seq]
Purpose: Hutchinson-Gilford progeria syndrome (HGPS) is the result of a defective form of the lamin A protein called progerin. While progerin is known to disrupt the properties of the nuclear lamina, the underlying mechanisms responsible for the pathophysiology of HGPS remain less clear. Previous studies in our laboratory have shown that progerin expression in murine epidermal basal cells results in impaired stratification and halted development of the skin. Stratification and differentiation of the epidermis is regulated by asymmetric stem cell division. Methods: Primary keratinocytes were isolated from HGPS and wild-type mice, and processed for FACS. Isolated keratinocytes were incubated with anti-a6-integrin (CD49f) and anti-CD45 (30-F11) antibodies. Samples were sorted into basal (CD45neg/CD49fhigh) and suprabasal (CD45neg/CD49flow) populations using a FACScalibur flow cytometer. After sorting, RNA was extracted and subjected to cDNA synthesis, ligation of adapters and amplification of indexed libraries. The indexed cDNA libraries were sequenced on the Illumina HiSeq 2000. The generated sequence reads were mapped to the mouse genome (mm10) using Galaxy software. Sequences were aligned to the reference genome using TopHat (Trapnell et al., 2009) and differential expression analysis was done using Cufflinks (Trapnell et al., 2012). Results: Here, we show that expression of progerin impairs stem cells ability to maintain tissue homeostasis as a result of altered cell division. Quantification of basal skin cells showed an increase in symmetric cell division that correlated with progerin accumulation in HGPS mice. Investigation of the mechanisms underlying this phenomenon revealed a putative role of Wnt/ß-catenin signaling. Further analysis suggested an alteration in the nuclear translocation of ß-catenin involving the inner and outer nuclear membrane proteins, emerin and nesprin-2. Conclusions: Taken together our results suggest a direct involvement of progerin in the transmission of Wnt signaling and normal stem cell division. These new insights into the molecular mechanisms of progerin may help develop new treatment strategies for HGPS. Overall design: Skin suprabasal and basal mRNA profiles of 4-day old wild type (WT) and bitransgenic HGPS (BT) mice were generated by sequencing using Illumina HiSeq2000.