Sympathetic ganglia are primarily composed of noradrenergic neurons and satellite glial cells. Although both cell types originate from neural crest cells, the identities of the progenitor populations at intermediate stages of the differentiation process remain to be established. Here we report the identification in vivo of glial and neuronal progenitor cells in postnatal sympathetic ganglia, using mouse superior cervical ganglia as a model system. There are significant levels of cellular proliferation in mouse superior cervical ganglia during the first 18 days after birth. A majority of the proliferating cells express both nestin and brain lipid-binding protein (BLBP). BrdU fate-tracing experiments demonstrate that these nestin and BLBP double positive cells represent a population of glial progenitors for sympathetic satellite cells. The glial differentiation process is characterized by a marked downregulation of nestin and upregulation of S100, with no significant changes in the levels of BLBP expression. We also identify a small number of proliferating cells that express nestin and tyrosine hydroxylase, a key enzyme of catecholamine biosynthesis that defines sympathetic noradrenergic neurons. Together, these results establish nestin as a common marker for sympathetic neuronal and glial progenitor cells and delineate the cellular basis for the generation and maturation of sympathetic satellite cells. Keywords noradrenergic neurons; satellite cells; superior cervical ganglia; postnatal sympathetic developmentThe sympathetic nervous system is composed of sympathetic ganglia and the adrenal medulla, a specialized sympathetic ganglion containing secretory chromaffin cells. Sympathetic ganglia of mammals are organized into two paravertebral chains that span from cervical to sacral regions, with the ganglia being interconnected with pre-and postganglionic sympathetic nerve fibers. Sympathetic ganglia contain two major cell types, neurons and glial cells. Most mammalian sympathetic neurons use noradrenaline as a neurotransmitter and, thus, are called noradrenergic neurons. These neurons are commonly marked by their expression of tyrosine hydroxylase (TH) that catalyzes the rate-limiting step (Cocchia and Michetti, 1981).It is well established that sympathetic neurons and glia are derived from neural crest cells (Anderson, 1989;LaBonne and Bronner-Fraser, 1998;Le Douarin and Dupin, 1993), a transient, highly migratory population of multipotent stem/progenitor cells. The neural crest can be divided into four regions along the anterior-posterior axis: cranial, vagal, trunk, and lumbosacral neural crest. During sympathetic development, neural crest cells, mainly from the trunk region of the neural crest, migrate ventrally and aggregate adjacent to the dorsal aorta to form the primary sympathetic chain. A subpopulation of the cells then undergo dorsal migration to form the paravertebral sympathetic ganglia where they differentiate into sympathetic neurons and glial cells (Francis and Landis, 1999;Kirby and Gilmore...

We used fluorescence in situ hybridization (FISH) to study the positions of human chromosomes on the mitotic rings of cultured human lymphocytes, MRC-5 fibroblasts, and CCD-34Lu fibroblasts. The homologous chromosomes of all three cell types had relatively random positions with respect to each other on the mitotic rings of prometaphase rosettes and anaphase cells. Also, the positions of the X and Y chromosomes, colocalized with the somatic homologues in male cells, were highly variable from one mitotic ring to another. Although random chromosomal positions were found in different pairs of CCD-34Lu and MRC-5 late-anaphases, the separations between the same homologous chromosomes in paired late-anaphase and telophase chromosomal masses were highly correlated. Thus, although some loose spatial associations of chromosomes secondary to interphase positioning may exist on the mitotic rings of some cells, a fixed order of human chromosomes and/or a rigorous separation of homologous chromosomes on the mitotic ring are not necessary for normal mitosis. Furthermore, the relative chromosomal positions on each individual metaphase plate are most likely carried through anaphase into telophase.

Abstract-We performed an initial screen of 11 rat strains by use of a standard balloon injury to the left iliac artery to observe whether genetically determined differences existed in the development of neointimal hyperplasia. Neointimal hyperplasia was assayed 8 weeks after the vascular injury on coded microscopic sections. Statistically significant differences in the percentages of the vascular wall cross-sectional areas composed of intima (percentage intima) secondary to neointimal hyperplasia were noted among the different rat strains (PϽ0.02), with the Brown-Norway (BN), Dark Agouti, and Milan normotensive strain rats having the highest and the spontaneously hypertensive rats (SHR) having the lowest percentages of intima. In a separate experiment, F 1 hybrids of SHRϫBN strains and parental BN and SHR underwent the vascular injury, and the parental strains again showed a statistically significant difference from one another in the mean percentage of intima (PϽ0.0001). The F 1 hybrids showed an average percentage of intima intermediate between those of the parental strains. The average lumen size of the injured BN vessels were significantly smaller than that of the noninjured control vessels (Pϭ0.044), but this significance disappeared when the circular areas of these vessels were calculated without taking neointimal growth into consideration (Pϭ0.649). These results provide the groundwork for a genetic linkage analysis to identify the genes that influence the development of neointimal hyperplasia after vascular injury. (Circ Res. 1999;84:1252-1257.)

age analysis of neointimal hyperplasia and vascular wall transformation after balloon angioplasty. Physiol Genomics 25: 286 -293, 2006. First published January 24, 2006 doi: 10.1152/physiolgenomics.00135.2005.-Neointimal hyperplasia (NIH), a result of vascular injury, is due to the migration and proliferation of smooth muscle cells through the media and internal elastic lamina leading to vascular occlusion. We used a rat model to find the genetic regions controlling NIH after endothelial denudation in two divergent inbred strains of rats. The Brown Norway (BN) and spontaneously hypertensive rat (SHR) strains have a 2.5-fold difference in injury-induced NIH. A population of 301 F2 (SHR ϫ BN) rats underwent a standard vascular injury followed by phenotyping 8 wk after injury to identify quantitative trait loci (QTL) responsible for this strain difference. Interval mapping identified two %NIH QTL on rat chromosomes 3 and 6 [logarithm of odds (LOD) scores 2.5, 2.2] and QTL for other injured vascular wall changes on rat chromosomes 3, 4, and 15 (LOD scores 2.0 -4.6). Also, QTL for control vessel media width (MW) and media area (MA) were found on chromosome 6 with LOD scores of 2.3 and 2.5, suggesting that linkage exists between these control vessel parameters and NIH production. These results represent the first genetic analysis for the identification of NIH QTL and QTL associated with the vascular injury response.quantitative trait loci; restenosis; vascular injury; inbred strains; Brown Norway rat; spontaneously hypertensive rat INTERVENTIONS IN THE CARDIOVASCULAR system such as arterial grafts, stents, and balloon angioplasties often fail because of the development of neointimal hyperplasia (NIH). There are no effective therapies to prevent or treat this complication. For example, restenosis secondary to NIH occurs in 30 -40% of patients after balloon angioplasty for coronary artery disease (27). Drug-eluting stents reduce the occurrence of short-term NIH to 20 -30%, but the long-term efficacy of these devices is not known (27). NIH is also associated with the development of significant restenosis in 20% of patients undergoing carotid endarterectomy (1) and is a major contributor to graft failure in coronary and peripheral arteries (24).NIH is triggered by vascular endothelial cell (VEC) disruption and injury that leads to smooth muscle cell (SMC) migration to subendothelial injury sites, followed by SMC proliferation and apoptosis. Significant neointimal thickening and decreased lumen areas are seen within 2 wk after vascular injury (16, 32). However, vascular occlusion can continue after 2 wk as SMC size increases (16, 32) and proteoglycan matrix deposits continue to thicken the neointima (8,28,36,37,45). Many factors are involved in, and possibly responsible for, genetically determined variations in the NIH injury response between different strains of animals and among individual patients (1). We postulate that heritable variations in the genes for these vascular injury response elements are possible candidate...

S U M M A R Y Aneuploid cancers exhibit a wide spectrum of clinical aggressiveness, possibly because of varying chromosome compositions. To test this, karyotypes from the diploid CCD-34Lu fibroblast and the aneuploid A549 and SUIT-2 cancer lines underwent fluorescence in situ hybridization (FISH) and DAPI counterstaining. The number of DAPI-stained and FISH-identified chromosomes, 1-22, X,Y, as well as structural abnormalities, were counted and compared using the 2 , Mann-Whitney rank sum test and the Levene's equality of variance. Virtually all of the evaluable diploid CCD-34Lu karyotypes had 46 chromosomes with two normal-appearing homologues. The aneuploid chromosome numbers per karyotype were highly variable, averaging 62 and 72 for the A549 and SUIT-2 lines, respectively. However, the A549 chromosome numbers were more narrowly distributed than the SUIT-2 karyotype chromosome numbers. Furthermore, 25% of the A549 chromosomes had structural abnormalities compared to only 7% of the SUIT-2 chromosomes. The chromosomal compositions of the aneuploid A549 and SUIT-2 cancer lines are widely divergent, suggesting that diverse genetic alterations, rather than chance, may govern the chromosome makeups of aneuploid cancers.

The relationship between the apparently random chromosomal changes found in aneuploidy and the genetic instability driving the progression of cancer is not clear. We report a test of the hypothesis that aneuploid chromosomal abnormalities might be selected to preserve cell-survival genes during loss of heterozygosity (LOH) formations which eliminate tumor suppressor genes. The LOHs and structurally abnormal chromosomes present in the aneuploid LoVo (colon), A549 (lung), SUIT-2 (pancreas), and LN-18 (glioma) cancer cell lines were identified by single nucleotide polymorphisms (SNPs) and Spectral Karyotyping (SKY). The Mann-Whitney U and chi square tests were used to evaluate possible differences in chromosome numbers and abnormalities between the cell lines, with two-tailed P values of <0.01 being considered significant. The cell lines differed significantly in chromosome numbers and frequency of structurally abnormal chromosomes. The SNP analysis revealed that each cell line contained at least a haploid set of somatic chromosomes, consistent with our hypothesis that cell-survival genes are widely scattered throughout the genome. Further, over 90% of the chromosomal abnormalities seemed to be selected, often after LOH formation, for gene-dosage compensation or to provide heterozygosity for specific chromosomal regions. These results suggest that the chromosomal changes of aneuploidy are not random, but may be selected to provide gene-dosage compensation and/or retain functional alleles of cell-survival genes during LOH formation.

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