A promoter that drives gene expression preferentially in male transgenic rats.

Gender-preferential gene expression is a widespread phenomenon in humans. It is important to study how gender differences influence the pathogenesis of various diseases and response to specific drugs. The aim of this study is to determine if the mouse albumin enhancer/promoter may serve as the promoter to introduce gender-preferential gene expression in transgenic animals.

Transplantation of human undifferentiated embryonic stem cells into a myocardial infarction rat model.

Human embryonic stem (hES) cells hold great therapeutic potential for cell transplantation. To date, it remains uncertain whether undifferentiated hES cells can differentiate into cardiac lineage in vivo during myocardial infarction. Here we provide the first report that undifferentiated hES cells can survive in rat hearts during myocardial infarction without the formation of teratoma using undifferentiated green fluorescent protein (GFP)-transgenic hES cells.

Impaired expression of PPAR gamma protein contributes to the exaggerated growth of vascular smooth muscle cells in spontaneously hypertensive rats.

Peroxisome proliferator-activated receptor gamma (PPAR gamma), a member of the nuclear receptor family, has been implicated in the regulation of vascular smooth muscle cell (VSMC) growth; however, the underlying mechanisms are still not fully understood. We hypothesized that PPAR gamma functional deficiency may contribute to the enhanced proliferation of VSMC associated with hypertension in spontaneously hypertensive rats (SHR). We observed that PPAR gamma mRNA level in SHR VSMC was 3 approximately 4 fold higher than that from Wistar-Kyoto rats (WKY), but the protein expression levels of PPAR gamma are significantly lower in SHR than WKY VSMC, suggesting an impaired control of PPAR gamma protein expression in SHR VSMC.

Peroxisome proliferator-activated receptors and the cardiovascular system.

Insulin resistance syndrome (also called syndrome X) includes obesity, diabetes, hypertension, and dyslipidemia and is a complex phenotype of metabolic abnormalities. The disorder poses a major public health problem by predisposing individuals to coronary heart disease and stroke, the leading causes of mortality in Western countries. Given that hypertension, diabetes, dyslipidemia, and obesity exhibit a substantial heritable component, it is postulated that certain genes may predispose some individuals to this cluster of cardiovascular risk factors.

Peroxisome proliferator-activated receptor delta is up-regulated during vascular lesion formation and promotes post-confluent cell proliferation in vascular smooth muscle cells.

Although peroxisome proliferator-activated receptor (PPAR) delta is widely expressed in many tissues, the role of PPARdelta is poorly understood. In this study, we report that PPARdelta was up-regulated in vascular smooth muscle cells (VSMC) during vascular lesion formation. By using Northern blot analysis, we demonstrated that PPARdelta was increased by 3-4-fold in VSMC treated with platelet-derived growth factor (PDGF) (20 ng/ml).