Barbara E. Rolfe

AN EARLY PREGNANCY FACTOR DETECTED IN HUMAN SERUM BY THE ROSETTE INHIBITION TEST

Modification of maternal lymphocyte activity has been demonstrated early in pregnancy by the rosette inhibition test. Normal human lymphocytes showed a similar depression of activity after incubation in serum from pregnant women, indicating that the response was caused by a serum factor. This early pregnancy factor has been differentiated from other substances which appear later in pregnancy and which may also be involved in the suppression of the maternal response. The results of this investigation suggest that the early pregnancy factor may be necessary for the continued viability of the early embryo.

Tissue-engineered blood vessels: alternative to autologous grafts?

Although vascular bypass grafting remains the mainstay for revascularization for ischemic heart disease and peripheral vascular disease, many patients do not have healthy vessels suitable for harvest. Thus, prosthetic grafts made of synthetic polymers were developed, but their use is limited to high-flow/low-resistance conditions because of poor elasticity, low compliance, and thrombogenicity of their synthetic surfaces. To fill this need, several laboratories have produced in vivo or in vitro tissue-engineered blood vessels using molds or prosthetic or biodegradable scaffolds, but each artificial graft has significant problems. Recently, conduits have been grown in the peritoneal cavity of the same animals in which they will be grafted, ensuring no rejection, in the short time of 2 to 3 weeks. Remodeling occurs after grafting such that the tissue is almost indistinguishable from native vessels. This conduit is derived from cells of bone marrow origin, opening new possibilities in vascular modeling and remodeling.

Multimodal Polymer Nanoparticles with Combined 19F Magnetic Resonance and Optical Detection for Tunable, Targeted, Multimodal Imaging in Vivo

Understanding the complex nature of diseased tissue in vivo requires development of more advanced nanomedicines, where synthesis of multifunctional polymers combines imaging multimodality with a biocompatible, tunable, and functional nanomaterial carrier. Here we describe the development of polymeric nanoparticles for multimodal imaging of disease states in vivo. The nanoparticle design utilizes the abundant functionality and tunable physicochemical properties of synthetically robust polymeric systems to facilitate targeted imaging of tumors in mice. For the first time, high-resolution (19)F/(1)H magnetic resonance imaging is combined with sensitive and versatile fluorescence imaging in a polymeric material for in vivo detection of tumors. We highlight how control over the chemistry during synthesis allows manipulation of nanoparticle size and function and can lead to very high targeting efficiency to B16 melanoma cells, both in vitro and in vivo. Importantly, the combination of imaging modalities within a polymeric nanoparticle provides information on the tumor mass across various size scales in vivo, from millimeters down to tens of micrometers.

Detection of Fetal Wastage

Production of the pregnancy-specific protein early pregnancy factor (EPF) was monitored by the rosette inhibition test in a group of 13 nulliparous women. EPF could be detected in serum within 48 hours of fertilization; of 28 cycles in which intercourse took place at the time of ovulation, EPF was detected in 18. However, EPF production continued for more than 14 days in only four cases. Successful pregnancy was maintained in two of these while in the other two, disappearance of EPF preceded miscarriage. In the remaining 14 cases, EPF disappeared from the serum before the onset of menstruation. A high incidence of early embryonic loss is suggested.

The peritoneal cavity as a bioreactor for tissue engineering visceral organs: bladder, uterus and vas deferens.

Our objective was to produce avascular, myofibroblast‐rich tissue capsules for use as autologous grafts for hollow, smooth muscle‐walled visceral organs–bladder, uterus and vas deferens. To produce tissue for grafting, templates of the appropriate shape were implanted in the peritoneal cavities of rats or rabbits. After 2–3 weeks, the templates were removed, the encapsulating myofibroblast‐rich tissue harvested and grafted to replace resected segments of bladder, vas deferens or uterus of the same animals in which the tissue was grown. Bladder grafts showed 100% patency after 14 months and had developed a morphology similar to normal bladder. Tubes of myofibroblast tissue grafted unilaterally into resected rabbit vasa deferentia developed a morphology resembling native tissue, with sperm in the ejaculate indicative of normal function. At 12 weeks after grafting, uterine graft tissue had increased in thickness and developed the morphology of normal uterus, with endometrium overlying several layers of smooth muscle cells (myometrium‐like) which were interspersed with collagen fibrils; grafted uterine horns supported embryos to the late stages of gestation. This study shows that myofibroblast tissue produced in the peritoneal cavity is sufficiently plastic to permit differentiation of cells into bladder, vas deferens or uterine smooth muscle. As a method for producing autologous graft material for repair/replacement of these organs, this approach has many benefits over conventional and current tissue‐engineering strategies. Copyright

Complement C5a inhibition reduces atherosclerosis in ApoE−/− mice

The complement C5a receptor, CD88, is present on many of the cells found within human atherosclerotic plaques, but little is known about the role of C5a in atherogenesis. Using real‐time PCR, we determined that ApoE–/– mice fed a normal diet express more aortic CD88 mRNA compared with controls, and this increase coincides with atherosclerotic lesion development (P< 0.001 for 3‐ vs. 25‐wk‐old animals). Conversely, mRNA expression of the alternative C5a receptor, C5L2, in aortas of ApoE–/– mice, was lower than controls at all time points. Using immunohistochemistry, we confirmed the presence of CD88 on macrophages, smooth muscle cells, and activated endothelial cells in plaques from brachiocephalic arteries. Treatment of ApoE–/– mice with a CD88 antagonist (PMX53; 3 mg/kg s.c. 3×/wk plus 1 mg/kg/d p.o.) for 25 wk reduced lesion size and lipid content in the plaque by ~40% (P<0.05). Our study provides evidence for a proatherogenic role for C5a and identifies the CD88 antagonist PMX53 as a potential antiatherosclerotic drug.—Manthey, H. D., Thomas, A. C., Shiels, I. A., Zernecke, A., Woodruff, T. M., Rolfe, B., Taylor, S. M. Complement C5a inhibition reduces atherosclerosis in ApoE–/– mice. FASEB J. 25, 2447–2455 (2011). www.fasebj.org

Enhanced effects of low molecular weight heparin intercalated with layered double hydroxide nanoparticles on rat vascular smooth muscle cells.

Surgical procedures to remove atherosclerotic lesions and restore blood flow also injure the artery wall, promoting vascular smooth muscle cell (SMC) phenotypic change, migration, proliferation, matrix production and ultimately, restenosis of the artery. Hence identification of effective anti-restenotic strategies is a high priority in cardiovascular research, and SMCs are a key target for intervention. This paper presents the in vitro study of layered double hydroxides (LDHs) as drug delivery system for an anti-restenotic drug (low molecular weight heparin, LMWH). The cytotoxicity tests showed that LDH itself had very limited toxicity at concentrations below 50 microg/mL over 6-day incubation. LDH nanoparticles loaded with LMWH (LMWH-LDHs) were prepared and tested on rat vascular SMCs. When conjugated to LDH particles, LMWH enhanced its ability to inhibit SMC proliferation and migration, with greater than above 60% reduction compared with the control (growth medium) over 3 or 7-day incubation. Cellular uptake studies showed that compared with LMWH alone, LMWH-LDH hybrids were internalized by SMCs more rapidly, and uptake was sustained over a longer time, possibly revealing the mechanisms underlying the enhanced biological function of LMWH-LDH. The results suggest the potential of LMWH-LDH as an efficient anti-restenotic drug for clinical application.

Ovum Factor: A First Signal of Pregnancy?

ABSTRACT: Previous studies have shown that, in the mouse, a factor is produced by the fertilized ovum within 24 h of mating. It cooperates with prolactin to stimulate ovarian production of component B of early pregnancy factor (EPF). This paper presents an initial characterization of the substance, termed ovum facor (OF).

Cellular plasticity of inflammatory myeloid cells in the peritoneal foreign body response.

Implantation of sterile foreign objects in the peritoneal cavity of an animal initiates an inflammatory response and results in encapsulation of the objects by bone marrow-derived cells. Over time, a multilayered tissue capsule develops with abundant myofibroblasts embedded in extracellular matrix. The present study used the transgenic MacGreen mouse to characterize the time-dependent accumulation of monocyte subsets and neutrophilic granulocytes in the inflammatory infiltrate and within the tissue capsule by their differential expression of the csf1r-EGFP transgene, F4/80, and Ly6C. As the tissue capsule developed, enhanced green fluorescent protein-positive cells changed from rounded to spindle-shaped morphology and began to co-express the myofibroblast marker alpha-smooth muscle actin. Expression increased with time: at day 14, 11.13 +/- 0.67% of tissue capsule cells co-expressed these markers, compared with 50.77 +/- 12.85% of cells at day 28. The importance of monocyte/macrophages in tissue capsule development was confirmed by clodronate-encapsulated liposome removal, which resulted in almost complete abrogation of capsule development. These results confirm the importance of monocyte/macrophages in the tissue response to sterile foreign objects implanted in the peritoneal cavity. In addition, the in vivo plasticity of peritoneal macrophages and their ability to transdifferentiate from a myeloid to mesenchymal phenotype is demonstrated.

Monoclonal antibodies to early pregnancy factor perturb tumour cell growth

The pregnancy‐associated substance early pregnancy factor (EPF) has previously been reported as a product of tumours of germ cell origin. More recently EPF (or an EPF‐related substance, tEPF) has also been detected in the serum of patients bearing tumours of non‐germ cell origin. We report here the production of tEPF by a variety of cultured transformed and tumour cell lines, of both germ and non‐germ cell origin. Antibodies specific for EPF remove all tEPF activity from tumour cell conditioned medium, tEPF production is found to be associated with cell division; tEPF is no longer detected after growth arrest or differentiation. Co‐culture of tumour cells with increasing doses of anti‐EPF monoclonal antibodies resulted in a significant, dose‐dependent decrease in rate of cell growth and viability. Similar anti‐EPF concentrations had no effect on the concanavalin A induced proliferation of mouse spleen cells. These studies suggest, therefore, that tEPF is a growth‐regulated product of cultured tumour and transformed cells. These cells are also dependent upon tEPF for continued growth, i.e. tEPF is acting in the autocrine mode.