Immunohistochemical Determination of HIF, TSP-1, ADAMTS1, and ADAMTS8 Expressions in the Brains of Alzheimer's Disease Patients: A Preliminary Autopsy Study

Objective: Alzheimer's disease (AD) is a progressive neurodegenerative disease that mostly affects the elderly population. Recent studies performed in AD highlight the pathophysiological relevance of disintegrin and metalloproteinase with thrombospondin type 1-like motifs (ADAMTS) genes and their products, namely hypoxia inducible factor-1 (HIF-1) and thrombospondin-1 (TSP-1). Thus, the aim of this study was to describe and identify the distribution, characteristics, and any changes in the expression and immunoreactivity for HIF-1, TSP-1, and ADAMTS1 and 8 in AD brains. Materials and Methods: Nine patients who were autopsied in the Council of Forensic Medicine, Bursa Morgue Department in 2013, were selected. All patients were sent for autopsy to the Morgue Department within 8 h after death. At the autopsy, tissue samples of the organs were obtained for histopathological examination for determining the cause of death. Among these, two patients were clinically diagnosed with AD. Results: Immunohistochemical staining was performed, and the staining intensity/extensity was evaluated using a semi-quantitative scoring system. Median distribution (extensity) scores of the immunohistochemical staining were estimated as 2 for HIF-1, 0.67 for TSP-1, 3.11 for ADAMTS1, and 2.78 for ADAMTS8. Intensity scores were estimated as 1.22 for HIF-1, 0.56 for TSP-1, 3 for ADAMTS1, and 2.11 for ADAMTS8. Conclusion: Our study suggests that ADAMTS1 and ADAMTS8 expressions are not specific for AD. To understand and provide definitive data on all aspects of metalloproteinases, extracellular matrix proteins, and transcriptional factor effects to AD, further studies are needed, where other metalloproteinases and related molecules/enzymes should be studied.