A comparison of LEDGFp52 and CNTF on the in vitro growth of rat retinal ganglion cell neurites

The significance of autoantibodies to DFS70/LEDGFp75 in health and disease: integrating basic science with clinical understanding

Antinuclear autoantibodies (ANAs) displaying the nuclear dense fine speckled immunofluorescence (DFS-IIF) pattern in HEp-2 substrates are commonly observed in clinical laboratory referrals. They target the dense fine speckled autoantigen of 70 kD (DFS70), most commonly known as lens epithelium-derived growth factor p75 (LEDGFp75). Interesting features of these ANAs include their low frequency in patients with systemic autoimmune rheumatic diseases (SARD), elevated prevalence in apparently healthy individuals, IgG isotype, strong trend to occur as the only ANA specificity in serum, and occurrence in moderate to high titers. These autoantibodies have also been detected at varied frequencies in patients with diverse non-SARD inflammatory and malignant conditions such as atopic diseases, asthma, eye diseases, and prostate cancer. These observations have recently stimulated vigorous research on their clinical and biological significance. Some studies have suggested that they are natural, protective antibodies that could serve as biomarkers to exclude a SARD diagnosis. Other studies suggest that they might be pathogenic in certain contexts. The emerging role of DFS70/LEDGFp75 as a stress protein relevant to human acquired immunodeficiency syndrome, cancer, and inflammation also points to the possibility that these autoantibodies could be sensors of cellular stress and inflammation associated with environmental factors. In this comprehensive review, we integrate our current knowledge of the biology of DFS70/LEDGFp75 with the clinical understanding of its autoantibodies in the contexts of health and disease.

Hepatoma-derived growth factor-related protein-3: a new neurotrophic and neurite outgrowth-promoting factor for cortical neurons

Hepatoma-derived growth factor-related proteins (HRPs) make up a family of six members. Hepatoma-derived growth factor-related protein-3 (HRP-3) is the only family member whose expression is almost restricted to nervous tissue. Here we show that soluble HRP-3 acts as a novel neurotrophic factor for cultured primary cortical neurons. Antibody-mediated neutralization of HRP-3 function results in neuronal degeneration. In contrast, HRP-3 as the only addition to a culture medium not supporting neuronal survival rescues neurons to an extent comparable to the addition of FCS. Besides this neuroprotective capability, the protein exerts a neurite outgrowth-promoting effect when it is presented as a coated substrate but not as a soluble factor. This study points to an important role of HRP-3 during the development of the nervous system.

Virological and cellular roles of the transcriptional coactivator LEDGF/p75

The chromatin-associated cellular proteins LEDGF/p75 and LEDGF/p52 have been implicated in transcriptional regulation, cell survival and autoimmunity. LEDGF/p75 also appears to act as a chromatin-docking factor or receptor for HIV-1 and other lentiviruses and to play a role in leukemogenesis. For both the viral and cellular roles of this protein, a key feature is its ability to act as a molecular adaptor and tether proteins to the chromatin fiber. This chapter reviews the emerging roles of LEDGF/p75 and LEDGF/p52 in diverse cellular processes and disease states.