[Frontiers in Bioscience E4, 1986-1998, January 1, 2012]

Localization and distribution of wolframin in human tissues

Maria De Falco1, Lucrezia Manente2, Angela Lucariello2, Gianluca Baldi3, Paola Fiore4,Vincenza Laforgia1, Alfonso Baldi4, Alessandro Iannaccone5, Antonio De Luca2

1Department of Biological Sciences, Section of Evolutionary and Comparative Biology, University of Naples "Federico II", Naples, Italy, 2Department of Medicine and Public Health, Section of Human Anatomy, Second University of Naples, Naples, Italy, 3Hospital of Nocera Inferiore" Umberto I", Service of Ophthalmology, Nocera Inferiore, Italy, 4Department of Biochemistry "F. Cedrangolo", Section of Pathologic Anatomy, Second University of Naples, Naples, Italy, 5Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, TN, USA


1. Abstract
2. Introduction
3. Materials and methods
3.1. Generation of a polyclonal antibody against wolframin
3.2.Dot blot
3.3. Human cell lines
3.4. Protein extraction and western blotting analysis
3.5. Normal foetal and adult human tissues
3.6. Immunohistochemistry
4. Results
4.1. Antibody characterization
4.2. Western blot analysis
4.3. Wolframin localization in foetal human tissues
4.4. Wolframin localization in adult human tissues
5. Discussion
6. Acknowledgments
7. References


Wolframin is a transmembrane glycoprotein of 890 aminoacids, encoded by WFS1 gene. WFS1 mutations are responsible for Wolfram syndrome, an autosomal recessive disorder. In the present paper, we first characterized the polyclonal wolframin antibody by dot blot. Secondly, we verified antibody specificity by western blotting using different human cell lines. Thirdly, we studied wolframin localization in human foetal (14-35 weeks) and adult tissues by immunohistochemistry. Wolframin expression was distributed in many organs, with different tissue and cell localization and expression levels. In foetal systems, wolframin expression was faint at 14-16 weeks and increased when development proceeded. In adult human tissues a variable positive staining was observed in both simple and stratified epithelia. A moderate wolframin expression was observed in liver and in the endocrine portion of the pancreas. In conclusion, our data suggest that this protein may have important roles in a number of different tissues, including many that are not known to be affected by WFS1-linked diseases. The immunopositivity in adult human tissues suggests that it may function maintaining physiological cellular homeostasis.