Obesity (Silver Spring)
April 2009
The nuclear hormone receptor peroxisome proliferator-activated receptor-gamma (PPAR-gamma) functions as the "master switch" in adipocyte development and is important in regulating glucose metabolism. PPAR-gamma is rapidly degraded in adipocytes by the ubiquitin proteasome pathway under basal and ligand-activated conditions. Proteasome inhibition increases PPAR-gamma activity, indicating disposal of PPAR-gamma by the ubiquitin proteasome system regulates PPAR-gamma activity.
View Article and Find Full Text PDFHuman adenovirus Ad-36 is causatively and correlatively linked with animal and human obesity, respectively. Ad-36 enhances differentiation of rodent preadipocytes, but its effect on adipogenesis in humans is unknown. To indirectly assess the role of Ad-36-induced adipogenesis in human obesity, the effect of the virus on commitment, differentiation, and lipid accumulation was investigated in vitro in primary human adipose-derived stem/stromal cells (hASC).
View Article and Find Full Text PDFObjective: To characterize equine adipose tissue-derived stromal cell (ASC) frequency and growth characteristics and assess of their adipogenic and osteogenic differentiation potential.
Study Design: In vitro experimental study.
Animals: Horses (n=5; aged, 9 months to 5 years).
Adipose tissue serves as a source of adipokines and cytokines with both local and systemic actions in health and disease. In this study, we examine the hypothesis that multipotent human adipose-derived stem cells (ASCs), capable of differentiating along the adipocyte, chondrocyte, and osteoblast pathways, contribute to adipose tissue-derived cytokine secretion. Following exposure to basic fibroblast growth factor (bFGF) or epidermal growth factor (EGF), the ASCs significantly increase their secretion of hepatocyte growth factor (HGF), a cytokine implicated in hematopoiesis, vasculogenesis, and mammary epithelial duct formation.
View Article and Find Full Text PDFObjectives: To characterize equine bone marrow (BM)-derived mesenchymal stem cell (MSC) growth characteristics and frequency as well as their adipogenic and osteogenic differentiation potential.
Study Design: In vitro experimental study.
Animals: Foals (n=3, age range, 17-51 days) and young horses (n=5, age range, 9 months to 5 years).
Mouse lines with targeted disruption of the cocaine amphetamine-related transcript (CART), melanocortin receptor 3 (MCR3), or melanocortin receptor 4 (MCR4) were used to assess the role of each component in mediating the anorectic and metabolic effects of leptin, and in regulating the partitioning of nutrient energy between fat and protein deposition. Leptin was administered over a 3 day period using either intraperitoneal or intracerebroventricular routes of injection. The absence of MCR4 blocked leptin's ability to increase UCP1 mRNA in both brown and white adipose tissue, but not its ability to reduce food consumption.
View Article and Find Full Text PDFAlu elements have inserted in the human genome throughout primate evolution. A small number of Alu insertions have occurred after the divergence of humans from nonhuman primates and therefore should not be present in nonhuman primate genomes. Most of these recently integrated Alu elements are contained with a series of discrete Alu subfamilies that are related to each other based upon diagnostic nucleotide substitutions.
View Article and Find Full Text PDFA comprehensive analysis of two Alu Y lineage subfamilies was undertaken to assess Alu-associated genomic diversity and identify new Alu insertion polymorphisms for the study of human population genetics. Recently integrated Alu elements (283) from the Yg6 and Yi6 subfamilies were analyzed by polymerase chain reaction (PCR), and 25 of the loci analyzed were polymorphic for insertion presence/absence within the genomes of a diverse array of human populations. These newly identified Alu insertion polymorphisms will be useful tools for the study of human genomic diversity.
View Article and Find Full Text PDFThe L1 Ta subfamily of long interspersed elements (LINEs) consists exclusively of human-specific L1 elements. Polymerase chain reaction-based screening in nonhuman primate genomes of the orthologous sites for 249 human L1 Ta elements resulted in the recovery of various types of sequence variants for approximately 12% of these loci. Sequence analysis was employed to capture the nature of the observed variation and to determine the levels of gene conversion and insertion site homoplasy associated with LINE elements.
View Article and Find Full Text PDFHuman forensic casework requires sensitive quantitation of human nuclear DNA from complex sources. Widely used commercially available systems detect both nonhuman and human primate DNA, often require special equipment, and have a detection limit of approximately 0.1ng.
View Article and Find Full Text PDFLong and short interspersed elements (LINEs and SINEs) are retroelements that make up almost half of the human genome. L1 and Alu represent the most prolific human LINE and SINE families, respectively. Only a few Alu elements are able to retropose, and the factors determining their retroposition capacity are poorly understood.
View Article and Find Full Text PDFThe Ta (transcribed, subset a) subfamily of L1 LINEs (long interspersed elements) is characterized by a 3-bp ACA sequence in the 3' untranslated region and contains approximately 520 members in the human genome. Here, we have extracted 468 Ta L1Hs (L1 human specific) elements from the draft human genomic sequence and screened individual elements using polymerase-chain-reaction (PCR) assays to determine their phylogenetic origin and levels of human genomic diversity. One hundred twenty-four of the elements amenable to complete sequence analysis were full length ( approximately 6 kb) and have apparently escaped any 5' truncation.
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