Effect of trinucleotide repeat expansion on the expression of TCF4 mRNA in Fuchs' endothelial corneal dystrophy

Purpose: CTG trinucleotide repeat (TNR) expansion is frequently found in transcription factor 4 (TCF4) in Fuchs' endothelial corneal dystrophy (FECD), though the effect of TNR expansion on FECD pathophysiology remains unclear. The purpose of this study was to evaluate the effect of TNR expansion on TCF4 expression in corneal endothelium of patients with FECD. Methods: Peripheral blood DNA and Descemet membrane with corneal endothelium were obtained from 203 German patients with FECD. The CTG TNR repeat length in TCF4 was determined by short tandem repeat (STR) assays and Southern blotting using genomic DNA. Genotyping of rs613872 in TCF4 was performed by PCR. TCF4 mRNA levels in corneal endothelium were evaluated by quantitative PCR using three different probes. Control corneal endothelial samples were obtained from 35 non-FECD subjects. Results: The STR assay and Southern blotting showed that 162 of the 203 patients with FECD (80%) harbored CTG trinucleotide repeat lengths larger than 50. Quantitative PCR using all three probes demonstrated that TCF4 mRNA is significantly upregulated in the corneal endothelium of patients with FECD, regardless of the presence of TNR expansion. However, the length of the TNR tended to show a positive correlation with TCF4 expression level. No correlation was shown between the genotype of TCF4 SNP, rs613872, and the level of TCF4 expression. Conclusions: Our findings showed that TCF4 mRNA is upregulated in the corneal endothelium of patients with FECD. Further studies on the effects of TCF4 upregulation on corneal endothelial cell function will aid in understanding the pathophysiology of FECD

The Timing of Daily Demand for Goods and Services – Multivariate Probit Estimates and Microsimulation Results for an Aged Population with German Time Use Diary Data

Though consumption research provides a broad spectrum of theoretical and empirical founded results, studies based on a daily focus are missing. Knowledge about the individual timing of daily demand for goods and services, opens – beyond a genuine contribution to consumption research – interesting societal and macro economic as well as individual personal and firm perspectives: it is important for an efficient timely coordination of supply and demand in the timing perspective as well as for a targeted economic, social and societal policy for a better support of the every day coordination of life. Last not least, the individual daily public and private living situations will be visible, which are of particular importance for the social togetherness in family and society. Our study contributes to the timing of daily consumption for goods and services with an empirical founded microanalysis on the basis of more than 37.000 individual time use diaries of the nationwide Time Budget Survey of the German Federal Statistical Office 2001/02. We describe the individual timing of daily demand for goods and services for important socio-demographic groups like for women and men, the economic situation with income poverty and daily working hour arrangements. The multivariate microeconometric explanation of the daily demand for goods and services is based on a latent utility maximizing approach over a day. We estimate an eight equation Multivariate/Simultaneous Probit Model, which allows the decision for multiple consumption activities in more than one time period a day. The estimates quantify effects on the timing of daily demand by individual socio-economic variables, which encompasses, personal, household, regional characteristics as well as daily working hour arrangements within a flexible labour market. The question about individual effects of an aged society on the timing of daily demand for goods and services is analyzed with our microsimulation model ServSim and a population forecast for 2020 by the German Federal Statistical Office. Main result: There are significant differences in explaining the timing of daily demand for goods compared to services on the one hand and in particular for different daily time periods. The conclusion: without the timing aspects an important and significant dimension for understanding individual consumption behaviour and their impacts on other individual living conditions would be missing

Gene expression in the corneal endothelium of Fuchs endothelial corneal dystrophy patients with and without expansion of a trinucleotide repeat in TCF4.

Fuchs Endothelial Corneal Dystrophy (FECD) is a late onset, autosomal dominant eye disease that can lead to loss of vision. Expansion of a CTG trinucleotide repeat in the third intron of the transcription factor 4 (TCF4) gene is highly associated with FECD. However, only about 75% of FECD patients in the northern European population possess an expansion of this repeat. The remaining FECD cases appear to be associated with variants in other genes. To better understand the pathophysiology of this disease, we compared gene expression profiles of corneal endothelium from FECD patients with an expanded trinucleotide repeat (RE+) to those that do not have a repeat expansion (RE-). Comparative analysis of these two cohorts showed widespread RNA mis-splicing in RE+, but not in RE- samples. Quantitatively, we identified 39 genes in which expression was significantly different between RE+ and RE- samples. Examination of the mutation profiles in the RE- samples did not find any mutations in genes previously associated with FECD, but did reveal one sample with a rare variant of laminin subunit gamma 1 (LAMC1) and three samples with rare variants in the gene coding for the mitochondrial protein peripheral-type benzodiazepine receptor-associated protein 1 (TSPOAP1)

Genomic Southern Blot of DNA samples from normal control (lanes 1, 4, 7 and 8) and FECD patients (lanes 2, 3, 5, 6, 9–11).

<p>Lanes 12 and 13 are laboratory control samples that have not been evaluated for FECD. Note that the samples in lanes 2, 3 and 6 are from FECD patients that do not have the repeat expansion. The samples in lanes 5, 9, and 10 are samples from FECD cases with repeat expansion over 1500 repeats. Lane L contains sizing standards.</p

A comparison of TGC repeat length in TCF4 between FECD cases and normal controls.

*<p>p<0.001 for FECD cases vs. controls by Fisher's exact test.</p

DNA sequence surrounding the trinucleotide repeat in the intron of the <i>TCF4</i> gene on chromosome 18.

<p>The trinucleotide repeat region is shown in red, and PCR primer sequences used for sizing the repeat region are underlined. This version of the sequence comes from the human reference sequence and contains 25 TGC repeats.</p