Faculty Bibliography

We previously found that certain hair proteins were soluble by means of a partial extraction method. In this study, we demonstrate that the amount of soluble proteins internally formed in permed and bleached hair, labile proteins, is a useful index for hair damage assessment. Compared to tensile property changes, this index rose in widely dynamic ranges as the time of either permanent waving or bleaching treatments increased. The amount of labile proteins was much larger than that of proteins eluted into perming and bleaching lotions. However, the labile proteins showed electrophoretic profiles similar to those of the eluted proteins. These results suggest that a portion of the stable proteins in normal hair was transformed into labile proteins upon permanent waving and bleaching treatments. Consequently, permed and bleached hair tends to release the resultant labile proteins

The Sonic hedgehog (Shh)-Gli signaling pathway regulates development of many organs, including teeth. We cloned a novel gene encoding a transcription factor that contains a zinc finger domain with highest homology to the Gli family of proteins (61-64% amino acid sequence identity) from incisor pulp. Consistent with this sequence conservation, gel mobility shift assays demonstrated that this new Gli homologous protein, GliH1, could bind previously characterized Gli DNA binding sites. Furthermore, transfection assays in dental pulp cells showed that whereas Gli1 induces a nearly 50-fold increase in activity of a luciferase reporter containing Gli DNA binding sites, coexpression of Gli1 with Gli3 and/or GliH1 results in inhibition of the Gli1-stimulated luciferase activity. In situ hybridization analysis of mouse embryos demonstrated that GliH1 expression is initiated later than the three Gli genes and has a more restricted expression pattern. GliH1 is first detected diffusely in the limb buds at 10.0 days post coitus and later is expressed in the branchial arches, craniofacial interface, ventral part of the tail, whisker follicles and hair, intervertebral discs, teeth, eyes and kidney. LacZ was inserted into the GliH1 allele in embryonic stem cells to produce mice lacking GliH1 function. While this produced indicator mice for GliH1-expression, analysis of mutant mice revealed no discernible phenotype or required function for GliH1. A search of the Celera Genomics and associated databases identified possible gene sequences encoding a zinc finger domain with approximately 90% homology to that of GliH1, indicating there is a family of GliH genes and raising the possibility of overlapping functions during development

OBJECTIVE: To examine whether spindle morphologic features imaged with the LC-PolScope (Cambridge Research and Instrumentation, Woburn, MA) in living human oocytes matured in vitro can be used to predict chromosome configuration and select oocytes with normal chromosomes. DESIGN: Morphological study. SETTING: Academic IVF clinic. PATIENT(S): Women undergoing oocyte retrieval for ICSI treatment. INTERVENTION(S): Oocytes were examined after in vitro maturation. MAIN OUTCOME MEASURE(S): The study examined meiotic spindle morphologic features and chromosome alignments. RESULT(S): After culture for 22 to 24 hours, 77.1% of oocytes reached metaphase II stage, with 51.9% of oocytes showing birefringent spindles. Confocal microscopy revealed that 71% of oocytes with the birefringent spindles had normal chromosome alignment, and 29% of oocytes with birefringent spindles and all oocytes without birefringent spindles had abnormal microtubule organization and abnormal chromosome alignment. CONCLUSION(S): The spindle images obtained with the PolScope in living human oocytes are coordinate with those in fixed oocytes as imaged by confocal microscopy. Spindle images with the PolScope can be applied to human in vitro fertilization to help predict chromosomally normal oocytes for insemination

OBJECTIVE: To explore the inhibitory effect of human endostatin gene mediated by retroviral vector on the growth of human liver carcinoma. METHODS: A recombinant retroviral plasmid containing human endostatin gene and signal peptide was engineered and transferred into PA317 cells to produce retrovirus. Human liver carcinoma cells (SMMC7721) were infected with the above retrovirus to build a stable endostatin-transfected liver carcinoma cell line (SMMC-endo). The control liver carcinoma cell line (SMMC-pLncx) was developed in a similar way except that the plasmid was replaced by an empty retroviral vector. Immunohistochemistry and Western blot were used to test the expression and secretion of human endostatin. The biological activity of the expressed human endostatin was assessed by endothelial cell proliferation assay. The growth rates of SMMC-endo and control SMMC-pLncx cells in vivo and in vitro were also observed. RESULTS: The expression and secretion of human endostatin by endostatin-transfected SMMC-endo cells were confirmed by immunohistochemistry and Western blot. Compared with the control group, concentrated supernatant of SMMC-endo cells remarkably inhibited the proliferation of human umbilical vein endothelial cells by 48%, significantly higher than the inhibition by the control (10.2%; P < 0.01). The endostatin-transfected SMMC-endo cells had similar in vitro growth rates to SMMC-pLncx cells. The in vivo experiment showed that the growth rate of SMMC-endo cells was slowed. Only in 3 out of 5 mice were tumors formed and flank tumors of SMMC-endo cells were 94.5% smaller than those of control cells 22 days after inoculation into nude mice (P < 0.001). CONCLUSIONS: Gene transfer of human endostatin mediated by retroviral vector is an effective form of cancer therapy

Presenilin 1 (PS1), presenilin 2, and nicastrin form high molecular weight complexes that are necessary for the endoproteolysis of several type 1 transmembrane proteins, including amyloid precursor protein (APP) and the Notch receptor, by apparently similar mechanisms. The cleavage of the Notch receptor at the 'S3-site' releases a C-terminal cytoplasmic fragment (Notch intracellular domain) that acts as the intracellular transduction molecule for Notch activation. Missense mutations in the presenilins cause familial Alzheimer's disease by augmenting the 'gamma-secretase' cleavage of APP and overproducing one of the proteolytic derivatives, the Abeta peptide. Null mutations in PS1 inhibit both gamma-secretase cleavage of APP and S3-site cleavage of the Notch receptor. Mice lacking PS1 function have defective Notch signaling and die perinatally with severe skeletal and brain deformities. We report here that a genetic modifier on mouse distal chromosome 1, coinciding with the locus containing Nicastrin, influences presenilin-mediated Notch S3-site cleavage and the resultant Notch phenotype without affecting presenilin-mediated APP gamma-site cleavage. Two missense substitutions of residues conserved among vertebrates have been identified in nicastrin. These results indicate that Notch S3-site cleavage and APP gamma-site cleavage are distinct presenilin-dependent processes and support a functional interaction between nicastrin and presenilins in vertebrates. The dissociation of Notch S3-site and APP gamma-site cleavage activities will facilitate development of gamma-secretase inhibitors for treatment of Alzheimer's disease