Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.34 (lipoprotein lipase)
 7,025 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hyperplasia is a major contributor to the increase in adipose tissue mass that is characteristic of obesity. However, the identity and characteristics of cells that can be committed into adipocyte lineage remain unclear. Stem cell antigen 1 (Sca-1) has been used recently as a candidate marker in the search for tissue-resident stem cells. In our quest for biomarkers of cells that can become adipocytes, we analyzed ear mesenchymal stem cells (EMSC), which can differentiate into adipocytes, osteocytes, chondrocytes, and myocytes. Our previous studies have demonstrated that EMSC abundantly expressed Sca-1. In the present study, we have analyzed the expression of adipogenic transcription factors and adipocyte-specific genes in Sca-1-enriched and Sca-1-depleted EMSC fractions. Sca-1-enriched EMSC accumulated more lipid droplets during adipogenic differentiation than Sca-1-depleted. Similarly, EMSC isolated from Sca-1(-/-) mice displayed reduced lipid accumulation relative to EMSC from wild-type controls (p < .01). Comparative analysis of the adipogenic differentiation process between Sca-1-enriched and Sca-1-depleted populations of EMSC revealed substantial differences in the gene expression. Preadipocyte factor 1, CCAAT enhancer-binding protein (C/EBP) beta, C/EBPalpha, peroxisome proliferator-activated receptor gamma2, lipoprotein lipase, and adipocyte fatty acid binding protein were expressed at significantly higher levels in the Sca-1-enriched EMSC fraction. However, the most striking observation was that leptin was detected only in the conditioned medium of Sca-1-enriched EMSC. In addition, we performed loss-of-function (Sca-1 morpholino oligonucleotide) experiments. The data presented here suggest that Sca-1 is a biomarker for EMSC with the potential to become functionally active adipocytes. Disclosure of potential conflicts of interest is found at the end of this article.
 ...
PMID:IFATS collection: Stem cell antigen-1-positive ear mesenchymal stem cells display enhanced adipogenic potential. 1859 10

There is an extensive clinical need for soft tissue filler materials, such as adipose tissue, for plastic and reconstructive surgery. Due to limitations with autologous adipose transplantation, engineered adipose tissue provides a potential alternative therapy. Embryonic germ cells form embryoid bodies and subsequent embryoid body-derived (EBD) cells have the ability to differentiate toward multiple tissue types. The objective of this study was to demonstrate that EBD cells were capable of adipogenic differentiation in vitro and in vivo using a poly(ethylene glycol)-based hydrogel scaffold. EBD cells underwent adipogenic differentiation in vitro and in vivo. Results were directly compared to adipogenic differentiation of adult bone marrow-derived mesenchymal stem cells (MSCs). Differentiated EBD cells in both monolayer and three-dimensional in vitro culture demonstrated fat granules by light microscopy, stained positive for lipids with oil red-O, and expressed adipocyte-specific genes (lipoprotein lipase [LPL], peroxisome proliferator activated receptor gamma2, and adipocyte-specific fatty acid binding protein [alphaP2]). In vivo constructs demonstrated adipogenic differentiation by alphaP2 and LPL gene expression and oil red-O staining of lipid granules. In conclusion, EBD cells are capable of differentiating toward an adipogenic lineage in vitro and in vivo. EBD cells' adipogenic differentiation is comparable to that of MSCs and demonstrate therapeutic potential for soft tissue augmentation and reconstruction.
 ...
PMID:Embryonic germ cells are capable of adipogenic differentiation in vitro and in vivo. 1867 89

Mesenchymal stem cells are pluripotent progenitors that could be found in human bone marrow. Mesenchymal stem cells are capable of renewing themselves without differentiation in long-term culture. These cells also have low immunogenicity and can suppress alloreactive T cell responses. In the current study, mesenchymal stem cells isolated and propagated previously from the bone marrow of a megaloblastic anaemia patient were tested for their capabilities to differentiate into adipocytes, chondrocytes and osteoblasts in vitro. The differentiated cells were determined by Oil Red O, Alcian Blue-PAS and Alizarin Red S staining, and reverse transcriptase-polymerase chain reaction to determine the expression of mRNA specific for adipogenesis, chondrogenesis and osteogenesis. The results showed that the fibroblast-like cells were capable of differentiating into adipocytes, chondrocytes and osteoblasts upon chemical induction. The adipocytes, chondrocytes and osteoblasts were stained positively to Oil Red O, Alcian Blue-PAS and Alizarin Red S respectively. The differentiated cells were also found to express mRNA specific for adipogenesis ('peroxisome proliferation-activated receptor gamma2' and lipoprotein lipase), chondrogenesis (collagen type II) and osteogenesis (osteocalcin, osteopontin and alkaline phosphatase). In conclusion, this research has successfully isolated fibroblast-like cells from human bone marrow and these cells demonstrated morphological, cytochemical and immunochemical characteristics similar to mesenchymal stem cells. These cells maintain their proliferative properties and could be differentiated into the mesoderm lineage. The success of this study is vital because mesenchymal stem cells can be used in cellular therapy to regenerate or replace damaged tissues, or as a vehicle for therapeutic gene delivery in the future.
 ...
PMID:In-vitro differentiation study on isolated human mesenchymal stem cells. 1910 6

Circulating ghrelin elevates abdominal adiposity by a mechanism independent of its central orexigenic activity. In this study we tested the hypothesis that peripheral ghrelin induces a depot-specific increase in white adipose tissue (WAT) mass in vivo by GH secretagogue receptor (GHS-R(1a))-mediated lipolysis. Chronic iv infusion of acylated ghrelin increased retroperitoneal and inguinal WAT volume in rats without elevating superficial sc fat, food intake, or circulating lipids and glucose. Increased retroperitoneal WAT mass resulted from adipocyte enlargement probably due to reduced lipid export (ATP-binding cassette transporter G1 mRNA expression and circulating free fatty acids were halved by ghrelin infusion). In contrast, ghrelin treatment did not up-regulate biomarkers of adipogenesis (peroxisome proliferator-activated receptor-gamma2 or CCAAT/enhancer binding protein-alpha) or substrate uptake (glucose transporter 4, lipoprotein lipase, or CD36) and although ghrelin elevated sterol-regulatory element-binding protein 1c expression, WAT-specific mediators of lipogenesis (liver X receptor-alpha and fatty acid synthase) were unchanged. Adiposity was unaffected by infusion of unacylated ghrelin, and the effects of acylated ghrelin were abolished by transcriptional blockade of GHS-R(1a), but GHS-R(1a) mRNA expression was similar in responsive and unresponsive WAT. Microarray analysis suggested that depot-specific sensitivity to ghrelin may arise from differential fine tuning of signal transduction and/or lipid-handling mechanisms. Acylated ghrelin also induced hepatic steatosis, increasing lipid droplet number and triacylglycerol content by a GHS-R(1a)-dependent mechanism. Our data imply that, during periods of energy insufficiency, exposure to acylated ghrelin may limit energy utilization in specific WAT depots by GHS-R(1a)-dependent lipid retention.
 ...
PMID:Ghrelin induces abdominal obesity via GHS-R-dependent lipid retention. 1929 44

The effect of cell density on the adipogenic differentiation of human bone marrow-derived mesenchymal stem cells (MSCs) was investigated by using a patterning technique to induce the formation of a cell density gradient on a micropatterned surface. The adipogenic differentiation of MSCs at a density gradient from 5 x 10(3) to 3 x 10(4) cells/cm2 was examined. Lipid vacuoles were observed at all cell densities after 1-3 weeks of culture in adipogenic differentiation medium although the lipid vacuoles were scarce at the low cell density and abundant at the high cell density. Real-time RT-PCR analysis showed that adipogenesis marker genes encoding peroxisome proliferator-activated receptor gamma2 (PPARgamma2), lipoprotein lipase (LPL), and fatty acid binding protein-4 (FABP4) were detected in the MSCs cultured at all cell densities. The results suggest that there was no apparent effect of cell density on the adipogenic differentiation of human MSCs.
 ...
PMID:Effect of cell density on adipogenic differentiation of mesenchymal stem cells. 1930 72

Three kinds of photoreactive polyelectrolytes of polyallylamine (PAAm), poly(acrylic acid) (PAAc), and poly(vinyl alcohol) (PVA) were synthesized by the introduction of azidophenyl groups in the respective polymers. The photoreactive PAAm, PAAc, and PVA were micropatterned on polystyrene surfaces by photolithography. Observation with optical microscopy and scanning probe microscopy demonstrated the formation of a striped pattern of polyelectrolytes with a width of 200 microm. The micropatterned polyelectrolytes swelled in water. The micropatterned surfaces were used for cell culture of mesenchymal stem cells (MSCs) and their effects on adipogenic differentiation were investigated. The MSCs adhered to and proliferated evenly on the PAAm- and PAAc-patterned surfaces while they formed a cell pattern on the PVA-patterned surface. The PAAm-, PAAc-grafted, and polystyrene surfaces supported cell adhesion while the PVA-grafted surface did not. When cultured in adipogenic differentiation medium, the adipogenic differentiation of MSCs on the polyelectrolyte-patterned surfaces was demonstrated by the formation of lipid vacuoles and gene expression analysis. Oil Red-O-positive cells showed an even distribution on the PAAm- and PAAc-patterned surfaces, while they showed a pattern on the PVA-patterned surface. The fraction of Oil RedO-positive cells increased with culture time. The MSCs cultured on the PAAm-, PAAc-grafted, and polystyrene surfaces in adipogenic differentiation medium expressed the adipogenesis marker genes of peroxisome proliferator-activated receptor gamma2 (PPARgamma2), lipoprotein lipase (LPL), and fatty acid binding protein 4 (FABP4). These results indicate that the PAAm-, and PAAc-grafted, and polystyrene surfaces supported the adipogenesis of MSCs while a PVA-grafted surface did not.
 ...
PMID:Adipogenic differentiation of mesenchymal stem cells on micropatterned polyelectrolyte surfaces. 1944 1


<< Previous 1 2 3 4