We adapted filamentous phage vectors for targeted gene delivery to mammalian cells by inserting a mammalian reporter gene expression cassette (GFP) into the vector backbone and fusing the pIII coat protein to a cell targeting ligand (i.e. FGF2, EGF). Like transfection with animal viral vectors, targeted phage gene delivery is concentration, time, and ligand dependent. Importantly, targeted phage particles are specific for the appropriate target cell surface receptor. Phage have distinct advantages over existing gene therapy vectors because they are simple, economical to produce at high titer, have no intrinsic tropism for mammalian cells, and are relatively simple to genetically modify and evolve. Initially transduction by targeted phage particles was low resulting in foreign gene expression in 1-2 percent of transfected cells. We increased transduction efficiency by modifying both the transfection protocol and vector design. For example, we stabilized the display of the targeting ligand to create multivalent phagemid-based vectors with transduction efficiencies of up to 45 percent in certain cell lines when combined with genotoxic treatment. Taken together, these studies establish that the efficiency of phage-mediated gene transfer can be significantly improved through genetic modification. We are currently evolving phage vectors

Aim: To determine whether transcriptional reprogramming is capable of reversing the developmental aging of normal human somatic cells to an embryonic state. Materials & methods: An isogenic system was utilized to facilitate an accurate assessment of the reprogramming of telomere restriction fragment (TRF) length of aged differentiated cells to that of the human embryonic stem (hES) cell line from which they were originally derived. An hES-derived mortal clonal cell strain EN13 was reprogrammed by SOX2, OCT4 and KLF4. The six resulting induced pluripotent stem (iPS) cell lines were surveyed for telomere length, telomerase activity and telomere-related gene expression. In addition, we measured all these parameters in widely-used hES and iPS cell lines and compared the results to those obtained in the six new isogenic iPS cell lines. Results: We observed variable but relatively long TRF lengths in three widely studied hES cell lines (16.09–21.1 kb) but markedly shorter TRF lengths (6.4–12.6 kb) in five simil...

Use of deep neural network ensembles to identify embryonic-fetal transition markers: repression of COX7A1 in embryonic and cancer cells Use of deep neural network ensembles to identify embryonic-fetal transition markers: repression of COX7A1 in embryonic and cancer cells

Growing evidence supports the antagonistic pleiotropy theory of mammalian aging. Accordingly, changes in gene expression following the pluripotency transition, and subsequent transitions such as th...

Fibroblast growth factor 2 (FGF-2) and its receptors (FGFRs) are important regulators of bone cell function. Although FGF-2 is a major modulator of bone cell function, its expression and regulation in human osteoblasts have not been investigated. We examined FGF-2 messenger RNA (mRNA) expression and regulation in the human osteosarcoma MG-63 cells. Northern analysis revealed that MG-63 cells expressed FGF-2 mRNA transcripts of 7, 4, 2.2, and 1.3 kilobases (kb). In the absence of serum, treatment with transforming growth factor beta (TGF-beta; 0.1-10 ng/ml) increased all FGF-2 mRNA transcripts. Maximal increase was seen with 1 ng/ml of TGF-beta. TGF-beta increased FGF-2 mRNA expression within 2 h and this was sustained for 24 h. Phorbal myristate acetate (PMA; 1 microM) also increased FGF-2 mRNA at 6 h. Time course studies showed that TGF-beta did not significantly alter FGFR1 or FGFR2 mRNA expression in MG-63 cells. Western blotting with anti-human FGF-2 revealed that MG-63 cells synthesize three isoforms of FGF-2 protein of approximately 18, 22/23, and 24 kDa, which were increased after either 6 h or 24 h of treatment with TGF-beta. Increased FGF-2 mRNA and protein expression in response to TGF-beta was markedly reduced by the protein kinase A (PKA) inhibitor H-89. Immunogold labeling of MG-63 cells treated with TGF-beta showed increased labeling for FGF-2 and FGFR2 in the nuclei. In contrast, TGF-beta treatment significantly decreased FGFR1 labeling in the nuclei. These data show that TGF-beta regulates FGF-2 gene expression in human osteosarcoma cells. Furthermore, TGF-beta modulates the cellular localization of FGF-2 and its receptors.

Supercentenarians (≥110-year-old, SC) are a uniquely informative population not only because they surpass centenarians in age, but because they appear to age more slowly with fewer incidences of chronic age-related disease than centenarians. We reprogramed donor B-lymphoblastoid cell lines (LCL) derived from a 114-year-old (SC), a 43-year-old healthy disease-free control (HDC) and an 8-year-old with a rapid aging disease (Hutchinson-Gilford progeria syndrome (HGPS)) and compared SC-iPSC to HDC-iPSC and HGPS-iPSCs. Reprogramming to pluripotency was confirmed by pluripotency marker expression and differentiation to 3 germ-layers. Each iPSC clone differentiated efficiently to mesenchymal progenitor cells (MPC) as determined by surface marker expression and RNAseq analysis. We identified supercentenarian and HGPS associated gene expression patterns in the differentiated MPC lines that were not evident in the parental iPSC lines. Importantly, telomere length resetting occurred in iPSC from all donors albeit at a lower incidence in supercentenarian iPSCs. These data indicate the potential to use reprogramming to reset both developmental state and cellular age in the “oldest of the old.” We anticipate that supercentenarian iPSC and their differentiated derivatives will be valuable tools for studying the underlying mechanisms of extreme longevity and disease resistance.