ABSTRACT
Therapeutic interventions in reproductive biology have relied largely on steroids and antisteroids which act to regulate gene expression in target tissues. Whilst their use has transformed women's lives, few conceptual advances have been made in contraceptive technology, no means identified to improve human implantation and no new strategies developed for the treatment of benign gynaecology. A novel alternative is direct gene transfer to the organ of interest. As a first step to achieving this goal in the uterus, we used reporter gene constructs to transfect mouse endometrium in vivo and human endometrial epithelial cells in vitro. We injected DNA-liposome complexes into the uterine lumen of mice on day 2 of pseudopregnancy and detected reporter gene activity 2 days later. The liposomes used were a 3:1 (w/w) mixture of 2,3-dioleyloxy-N-[2(sperminecarboxamido) ethyl]-N-N-dimethyl-1-propanaminium trifluoroacetate and dioleoylphosphatidyl ethanolamine. Freshly isolated human endometrial epithelial cells were successfully transfected in vitro with similar DNA-liposome complexes. These data suggest that endometrial gene transfer may be effective in humans. This may lead to the development of new therapeutic agents, including contraceptives, for the improvement of women's health.
Subject(s)
Endometrium/enzymology , Gene Transfer Techniques , beta-Galactosidase/genetics , Animals , Cells, Cultured , DNA/administration & dosage , Epithelium/enzymology , Female , Histocytochemistry , Humans , Liposomes , Mice , Mice, Inbred BALB C , Pregnancy , PseudopregnancyABSTRACT
The pulpal response to orthodontic force is thought to involve cell damage, inflammation, and wound healing. These situations are likely to be associated with the release of angiogenic growth factors. We therefore investigated human dental pulps to determine if angiogenic changes could be detected after orthodontic force application. Fifteen premolar teeth were treated with straight-wire fixed orthodontic appliances for two weeks, and comparisons were made with 15 untreated control premolar teeth from the same subjects. The teeth were extracted and sectioned. The pulps were removed, divided into 1-mm sections, embedded in collagen, and cultured in growth media for up to four weeks. Cultures were examined daily, by light microscopy, for growth and number of microvessels. Apparent microvessels were observed within five days. Confirmation of microvessel identification was by electron microscopy for endothelial cell morphology. There were significantly greater numbers of microvessels at day five and day ten of culture in the pulp explants from orthodontically treated teeth compared with those from the pulps of control teeth. These results are consistent with the hypothesis that there is an increase in angiogenic growth factors in the pulp of orthodontically moved teeth.
Subject(s)
Dental Pulp/blood supply , Neovascularization, Physiologic , Tooth Movement Techniques , Angiogenesis Inducing Agents/metabolism , Bicuspid , Culture Techniques , Humans , Microcirculation , Microscopy, Electron , Time FactorsABSTRACT
The regulation of angiogenesis in the ovarian follicle and corpus luteum is unclear. Steroids are produced at very high concentrations in these tissues and we therefore examined the effect of steroids on angiogenesis in vitro. Explants of rat aorta were embedded in collagen gel and cultured in serum-free medium. Capillary-like microvessels were produced from the explants and microvessel number and length were measured in the presence and absence of steroids. At a concentration of 10 micrograms/ml, cortisol, progesterone, 17 alpha-hydroxyprogesterone and medroxyprogesterone acetate produced degeneration of microvessels after 7 days of steroid treatment (P < 0.01). Androstenedione and tetrahydro-S-(11-deoxytetrahydrocortisol) (tetrahydro S) produced degeneration at a slower rate: androstenedione inhibited microvessel growth after 11 days (P < 0.01) and tetrahydro S after 14 days (P < 0.05). Oestriol had no effect on microvessels; oestrone had a slow degenerative effect with significant inhibition seen after 14 days (P < 0.01). Oestradiol-17 beta at a concentration of 10 micrograms/ml completely inhibited microvessel growth from the explant cultures (P < 0.01) while at 1 microgram/ml it caused degenerative effects on growing microvessels. The effects of oestradiol and cortisol were reversible on removal of steroid-containing medium and replacement with 10% serum. We conclude that oestradiol may modulate angiogenesis in tissues in which the steroid concentration is high.
