Human ADA3 regulates RARα transcriptional activity through direct contact between LxxLL motifs and the receptor coactivator pocket

The alternation/deficiency in activation-3 (ADA3) is an essential component of the human p300/CBP-associated factor (PCAF) and yeast Spt-Ada-Gcn5-acetyltransferase (SAGA) histone acetyltransferase complexes. These complexes facilitate transactivation of target genes by association with transcription factors and modification of local chromatin structure. It is known that the yeast ADA3 is required for nuclear receptor (NR)-mediated transactivation in yeast cells; however, the role of mammalian ADA3 in NR signaling remains elusive. In this study, we have investigated how the human (h) ADA3 regulates retinoic acid receptor (RAR) α-mediated transactivation. We show that hADA3 interacts directly with RARα in a hormone-dependent manner and this interaction contributes to RARα transactivation. Intriguingly, this interaction involves classical LxxLL motifs in hADA3, as demonstrated by both ‘loss’ and ‘gain’ of function mutations, as well as a functional coactivator pocket of the receptor. Additionally, we show that hADA3 associates with RARα target gene promoter in a hormone-dependent manner and ADA3 knockdown impairs RARβ2 expression. Furthermore, a structural model was established to illustrate an interaction network within the ADA3/RARα complex. These results suggest that hADA3 is a bona fide transcriptional coactivator for RARα, acting through a conserved mechanism involving direct contacts between NR boxes and the receptor’s co-activator pocket

Novel Strategy for Generation and Titration of Recombinant Adeno-Associated Virus Vectors

Recombinant adeno-associated virus (rAAV) vectors have many advantages for gene therapeutic applications compared with other vector systems. Several methods that use plasmids or helper viruses have been reported for the generation of rAAV vectors. Unfortunately, the preparation of large-scale rAAV stocks is labor-intensive. Moreover, the biological titration of rAAV is still difficult, which may limit its preclinical and clinical applications. For this study, we developed a novel strategy to generate and biologically titrate rAAV vectors. A recombinant pseudorabies virus (PrV) with defects in its gD, gE, and thymidine kinase genes was engineered to express the AAV rep and cap genes, yielding PS virus, which served as a packaging and helper virus for the generation of rAAV vectors. PS virus was useful not only for generating high-titer rAAV vectors by cotransfection with an rAAV vector plasmid, but also for amplifying rAAV stocks. Notably, the biological titration of rAAV vectors was also feasible when cells were coinfected with rAAV and PS virus. Based on this strategy, we produced an rAAV that expresses prothymosin α (ProT). Expression of the ProT protein in vitro and in vivo mediated by rAAV/ProT gene transfer was detected by immunohistochemistry and a bioassay. Taken together, our results demonstrate that the PrV vector-based system is useful for generating rAAV vectors carrying various transgenes

Prothymosin α overexpression contributes to the development of pulmonary emphysema

Emphysema is one of the disease conditions that comprise chronic obstructive pulmonary disease. Prothymosin α transgenic mice exhibit an emphysema phenotype, but the pathophysiological role of prothymosin α in emphysema remains unclear. Here we show that prothymosin α contributes to the pathogenesis of emphysema by increasing acetylation of histones and nuclear factor-kappaB, particularly upon cigarette smoke exposure. We find a positive correlation between prothymosin α levels and the severity of emphysema in prothymosin α transgenic mice and emphysema patients. Prothymosin α overexpression increases susceptibility to cigarette smoke-induced emphysema, and cigarette smoke exposure further enhances prothymosin α expression. We show that prothymosin α inhibits the association of histone deacetylases with histones and nuclear factor-kappaB, and that prothymosin α overexpression increases expression of nuclear factor-kappaB-dependent matrix metalloproteinase 2 and matrix metalloproteinase 9, which are found in the lungs of patients with chronic obstructive pulmonary disease. These results demonstrate the clinical relevance of prothymosin α in regulating acetylation events during the pathogenesis of emphysema

Oral DNA vaccine adjuvanted with cyclic peptide nanotubes induced a virus-specific antibody response in ducklings against goose parvovirus

AbstractBackground Cyclic peptide nanotubes (cPNTs) formed from the spontaneous beta-sheet stacking of peptide rings may serve as a safe and effective oral delivery vehicle/adjuvant for DNA vaccines.Aim In this study, we sought to determine if a DNA vaccine expressing the VP2 protein of goose parvovirus, adjuvanted with cPNTs, may elicit virus-specific antibody response through oral vaccination.Material and methods Forty 20-day-old Muscovy ducks were randomly assigned to two groups of 20 ducks each and vaccinated. Ducks were orally vaccinated (Day 0) and boosted (Day 1 and Day 2) or were mock-vaccinated with saline as the negative control. For immunohistochemical staining, the primary antibody used comprised a rabbit anti-GPV antibody, and the secondary antibody was a goat anti-rabbit antibody. Goat-anti-mouse-IgG was used as a tertiary antibody. IgG and IgA antibody titers in serum were analyzed by the GPV virus-coated ELISA. For IgA antibody analysis, intestine lavage was harvested too.Results A DNA vaccine, coated with cPNTs, can induce a significant antibody response in ducklings. Immunohistochemical staining of tissues from vaccinated ducklings showed that VP2 proteins can be detected in the intestines and livers for up to six weeks, confirming the antigen expression by the DNA vaccine. Antibody analysis found that this vaccine formulation was very efficient at inducing IgA antibodies in the serum and the intestinal tract.Conclusion A DNA vaccine adjuvanted with cPNTs can effectively express the antigen and can significantly induce an antibody response against goose parvovirus through oral vaccination

A Solanum incanum extract (SR-T100) regresses vulvar condyloma acuminatum and induces distinct autophagic and apoptotic responses in different types of HPV-infected cells

Abstract Background The Solanum species have been used for the treatment of warts, tumor and cancer in folk medicine. The S. incanum extract is an important traditional Chinese medicine in Taiwan since 1973. The purpose of the present study was to evaluate the efficacy and safety of Solanum incanum (synonym: Solanum undatum) extract (SR-T100), a water-soluble product primarily composed of alkaloid solamargine, for the treatment of human condyloma and to study the possible underlying anti-condyloma mechanisms. Methods We conducted a pilot study to test the effectiveness and side effects of SR-T100 gel (2.3% solamargine in Solanum incanum plant extract) for the treatment of external genital warts. We produced different types of human papillomavirus (HPV) E6/E7-infected cells by lentiviral technology and studied the differences in apoptosis and autophagy between these cells under the treatment of SR-T100. Results Nineteen (73%) of 26 patients using the SR-T100 gel exhibited a response, and 16 (61.5%) patients achieved total clearance. Only one patient showed severe (grade 3-4) skin-related side effects. SR-T100 induced mitochondria-dependent apoptosis in HPV-infected cells. Cells expressing the high-risk HPV E6/E7 type were resistant to SR-T100-induced apoptosis. SR-T100 induced a greater autophagic response in HPV 16, 18-E6/E7 cells than in HPV 6b, 11-E6/E7 cells. Autophagy inhibition enhanced SR-T100-induced apoptosis in HPV 16, 18-E6/E7 cells, whereas apoptosis inhibition enhanced SR-T100-induced autophagy in HPV 6b, 11-E6/E7 cells. Conclusions SR-T100 is effective for the treatment of human vulva condyloma, with few side effects. Compared with those with high-risk HPVs, cells with low-risk HPVs were more sensitive to SR-T100 treatment. Autophagy played a protective role in SR-T100-induced apoptosis in HPV-infected cells. Trial registration NCT01676792 ; Registered: August 29, 2012 (retrospectively registered)