Accumulation of alpha-synuclein has been associated with neurodegenerative disorders, such as Lewy body disease and multiple system atrophy. We previously showed that expression of wild-type human alpha-synuclein in transgenic mice results in motor and dopaminergic deficits associated with inclusion formation. To determine whether different levels of human alpha-synuclein expression from distinct promoters might result in neuropathology mimicking other synucleopathies, we compared patterns of human alpha-synuclein accumulation in the brains of transgenic mice expressing this molecule from the murine Thy-1 and platelet-derived growth factor (PDGF) promoters. In murine Thy-1-human alpha-synuclein transgenic mice, this protein accumulated in synapses and neurons throughout the brain, including the thalamus, basal ganglia, substantia nigra, and brainstem. Expression of human alpha-synuclein from the PDGF promoter resulted in accumulation in synapses of the neocortex, limbic system, and olfactory regions as well as formation of inclusion bodies in neurons in deeper layers of the neocortex. Furthermore, one of the intermediate expressor lines (line M) displayed human alpha-synuclein expression in glial cells mimicking some features of multiple system atrophy. These results show a more widespread accumulation of human alpha-synuclein in transgenic mouse brains. Taken together, these studies support the contention that human alpha-synuclein expression in transgenic mice might mimic some neuropathological alterations observed in Lewy body disease and other synucleopathies, such as multiple system atrophy.

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Abstract-Although maternal-fetal cholesterol transfer may serve to compensate for insufficient fetal cholesterol biosynthesis under pathological conditions, it may have detrimental consequences under conditions of maternal hypercholesterolemia leading to preatherosclerotic lesion development in fetal aortas. Maternal cholesterol may enter fetal circulation by traversing syncytiotrophoblast and endothelial layers of the placenta. We hypothesized that endothelial cells (ECs) of the fetoplacental vasculature display a high and tightly regulated capacity for cholesterol release. Using ECs isolated from human term placenta (HPECs), we investigated cholesterol release capacity and examined transporters involved in cholesterol efflux pathways controlled by liver-X-receptors (LXRs). HPECs demonstrated 2.5-fold higher cholesterol release to lipid-free apolipoprotein (apo)A-I than human umbilical vein ECs (HUVECs), whereas both cell types showed similar cholesterol efflux to high-density lipoproteins (HDLs). Interestingly, treatment of HPECs with LXR activators increased cholesterol efflux to both types of acceptors, whereas no such response could be observed for HUVECs. In line with enhanced cholesterol efflux, LXR activation in HPECs increased expression of ATP-binding cassette transporters ABCA1 and ABCG1, while not altering expression of ABCG4 and scavenger receptor class B type I (SR-BI). Inhibition of ABCA1 or silencing of ABCG1 decreased cholesterol efflux to apoA-I (Ϫ70%) and HDL 3 (Ϫ57%), respectively. Immunohistochemistry localized both transporters predominantly to the apical membranes of placental ECs in situ. Thus, ECs of human term placenta exhibit unique, efficient and LXR-regulated cholesterol efflux mechanisms. We propose a sequential pathway mediated by ABCA1 and ABCG1, respectively, by which HPECs participate in forming mature HDL in the fetal blood. (Circ Res. 2009;104:600-608.)Key Words: maternal-fetal cholesterol transfer Ⅲ endothelial cells Ⅲ HDL Ⅲ liver X receptors C holesterol is indispensable during fetal development. 1 It has been long assumed that most, if not all, cholesterol required for fetal growth is synthesized de novo by the fetus itself, thus making it autonomous from maternal or placental cholesterol supply. However, several lines of evidence have cast doubt on this notion. 2,3 Fetuses that lack the ability to synthesize cholesterol, such as those with the Smith-LemliOpitz syndrome, are, nevertheless, born with low levels of tissue and plasma cholesterol, indicating that they have acquired maternal cholesterol in utero. 4 Recent exciting studies demonstrated a strong correlation between the size and number of atherosclerotic lesions in human fetal arteries with maternal cholesterol levels. 5,6 Moreover, maternal hypercholesterolemia also modified early predictors of cardiovascular disease in the offspring, thus corroborating the concept of developmental programming of adult disease in human. 7 Considering that progression of atherosclerosis in adults takes ages, these striking resu...

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Aims/hypothesis: The human placenta is a complex organ situated at the interface between mother and foetus that separates maternal from foetal blood. The placental surfaces exposed to the two bloodstreams are different, i.e. trophoblasts and endothelial cells are in contact with the maternal and foetal circulation, respectively. Both cell types produce high insulin receptor levels. The aim of the present study was to test the hypothesis that spatiotemporal changes in insulin receptor expression in trophoblasts from first trimester to the endothelium at term shift the control of insulin-dependent processes from mother to foetus. Methods: Global microarray analysis of primary trophoblasts from first trimester and term human placentas and endothelial cells from term human placentas cultured under hyperinsulinaemic and control conditions identified different sets of regulated genes in trophoblasts and endothelial cells. Results: Insulin effects on placental gene expression underwent developmental changes from trophoblasts in the first trimester to endothelial cells at term that were paralleled by changes in levels of activated insulin receptors. The changes in gene regulation were both quantitative (i.e. magnitude of effect) and qualitative (i.e. specific genes affected and direction of regulation). Conclusions/interpretation: This spatio-temporal shift in insulin sensitivity throughout pregnancy allows maternal and foetal insulin to regulate different processes within the placenta at different gestational stages, facilitated by compartmentalisation of the insulin response. Thus, by altering the levels and function of insulin receptors in space and time, control of insulin-dependent processes in the human placenta will change from mother to foetus throughout gestation. This will be of particular interest in conditions associated with altered maternal or foetal insulin levels, i.e. diabetes mellitus or intrauterine growth restriction.