Heritability of Lung Disease Severity in Cystic Fibrosis

Rationale: Obstructive lung disease, the major cause of mortality in cystic fibrosis (CF), is poorly correlated with mutations in the disease-causing gene, indicating that other factors determine severity of lung disease

Chemopreventive effects of metformin on obesity-associated endometrial proliferation

OBJECTIVE: Obesity is a significant contributing factor to endometrial cancer risk. We previously demonstrated that estrogen-induced endometrial proliferation is enhanced in the context of hyperinsulinemia and insulin resistance. In this study we investigate whether pharmacologic agents that modulate insulin sensitivity or normalize insulin levels will diminish the proliferative response to estrogen. STUDY DESIGN: Zucker fa/fa obese rats and lean controls were used as models of hyperinsulinemia and insulin resistance. Insulin levels were depleted in ovariectomized rats following treatment with Streptozotocin (STZ), or modulated by metformin treatment. The number of BrdU incorporated cells, estrogen dependent proliferative and anti-proliferative gene expression, and activation of mTOR and Erk1/2 MAPK signaling were studied. A rat normal endometrial cell line RENE1 was used to evaluate the direct effects of metformin on endometrial cell proliferation and gene expression in vitro. RESULTS: STZ lowered circulating insulin levels in obese rats and decreased the number of BrdU labeled endometrial cells even in the presence of exogenous estrogen. Treatment with the insulin-sensitizing drug metformin attenuated estrogen-dependent proliferative expression of c-myc and c-fos in the obese rat endometrium compared to untreated controls and was accompanied by inhibition of phosphorylation of the insulin and IGF1 receptors (IRβ/IGF1R) and ERK1/2. In vitro studies indicated metformin inhibited RENE1 proliferation in a dose dependent manner. CONCLUSION: These findings suggest that drugs that modulate insulin sensitivity, such as metformin, hinder estrogen-mediated endometrial proliferation. Therefore, these drugs may be clinically useful for the prevention of endometrial cancer in obese women

Epinephrine-induced activation of LW-mediated sickle cell adhesion and vaso-occlusion in vivo

Sickle red cell (SS RBC) adhesion is believed to contribute to the process of vaso-occlusion in sickle cell disease (SCD). We previously found that the LW RBC adhesion receptor can be activated by epinephrine to mediate SS RBC adhesion to endothelial αvβ3 integrin. To determine the contribution of LW activation to vaso-occlusive events in vivo, we investigated whether in vitro treatment of SS RBCs by epinephrine resulted in vaso-occlusion in intact microvasculature after RBC infusion into nude mice. Epinephrine enhanced human SS but not normal RBC adhesion to murine endothelial cells in vitro and to endothelium in vivo, promoting vaso-occlusion and RBC organ sequestration. Murine sickle RBCs also responded to epinephrine with increased adhesion to postcapillary endothelium in nude mice. Epinephrine-induced SS RBC adhesion, vaso-occlusion, and RBC organ trapping could be prevented by the β-adrenergic receptor (β-AR) antagonist, propranolol. Infusion of soluble recombinant LW also significantly reduced adhesion and vaso-occlusion. In addition, epinephrine-treated SS RBCs induced activation of murine leukocyte adhesion to endothelium as well. We conclude that LW activation by epinephrine via β-AR stimulation can promote both SS RBC and leukocyte adhesion as well as vaso-occlusion, suggesting that both epinephrine and LW play potentially pathophysiological roles in SCD