Basic Science and Pathogenesis.

Background: Globose neurofibrillary tangles (NFTs) are found in subcortical areas of post-mortem brain from individuals with the second most common primary tauopathy, progressive supranuclear palsy (PSP). The degree of cognitive impairment in secondary tauopathies such as Alzheimer's disease (AD) correlates with the presence of NFTs, which originally appear in the entorhinal cortex before spreading throughout the hippocampus. In contrast, the degree of hippocampal tau pathology in PSP is thought to be limited, consistent with the view that cognitive impairment in PSP is predominantly subcortical.

Mechanical tension alters semaphorin expression in the periodontium.

Background: Periodontal remodeling requires coordinated cell movement. Semaphorins are cell-surface signals that regulate cell migration and may be differentially regulated by periodontal cells. Mechanical tension can regulate periodontal ligament (PDL) remodeling.

A simple cell motility assay demonstrates differential motility of human periodontal ligament fibroblasts, gingival fibroblasts, and pre-osteoblasts.

During periodontal regeneration, multiple cell types can invade the wound site, thereby leading to repair. Cell motility requires interactions mediated by integrin receptors for the extracellular matrix (ECM), which might be useful in guiding specific cell populations into the periodontal defect. Our data demonstrate that fibroblasts exhibit differential motility when grown on ECM proteins.

Use of microarrays to find novel regulators of periodontal ligament fibroblast differentiation.

Periodontal regeneration requires the coordinated movement and differentiation of several cell types in order to re-establish the cementum, periodontal ligament (PDL), and alveolar bone. Cells in culture are often used as model systems for mature tissues, although they may represent expanded progenitor cell populations. Comparison of transcript expression between fresh PDL tissue and PDL cell isolates by MicroArray analysis has revealed numerous molecular differences.

Transcript profiling of periodontal fibroblasts and osteoblasts.

Background: Fibroblasts are critical to the establishment and maintenance of the periodontal attachment apparatus (cementum, periodontal ligament [PDL], and bone). In order to characterize the cellular changes that accompany periodontal regeneration, better tools are necessary to distinguish periodontal ligament fibroblasts (PDLF), gingival fibroblasts, and osteoblasts. Our goal is to identify gene markers to better characterize and identify these cell types.