PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 10361997

Commentary: aging, differentiation-dependent gene expression, and fat cell function.

J L Kirkland
View original source ↗Export metadata ↓

Abstract

The source did not provide an abstract. Follow the original record for more information.

Explore related subjects

AdipocytesAdipose TissueAgingAnimalsCCAAT-Enhancer-Binding ProteinsCell DifferentiationDNA-Binding ProteinsEnhancer Elements, GeneticGene Expression RegulationLeucine ZippersMacaca mulattaNuclear ProteinsPhenotypeRNA, MessengerReceptors, Cytoplasmic and NuclearSterol Regulatory Element Binding Protein 1Transcription FactorsZinc FingersCommentJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

J L Kirkland. 1999. Commentary: aging, differentiation-dependent gene expression, and fat cell function.. https://doi.org/10.1093/gerona%2F54.5.b189

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2001

Upregulation of uncoupling protein homologues in skeletal muscle but not adipose tissue in posttraumatic insulin resistance.

Metabolic alterations after surgical stress include peripheral insulin resistance and increased utilization of fat as a fuel substrate. An up-regulation of skeletal muscle uncoupling proteins (UCPs) has been associated with physiologic states of insulin resistance and enhanced fat metabolism in rodents. We examined whether posttraumatic insulin resistance induced the UCPs in gastrocnemius and soleus muscle and white adipose tissue in an experimental model of surgical trauma. Insulin sensitivity was significantly reduced in isolated soleus muscles but unchanged in adipocytes after trauma. In traumatized rats, mRNA and protein contents of UCP2 and UCP3 and were significantly increased in both muscle types. UCP2 protein content in adipose tissue was unaltered by surgical stress. Circulating NEFAs and glycerol were reduced after surgical trauma. We hypothesize that the changes in UCP2 and UCP3 gene and protein expression are involved in the regulation of substrate utilization in posttraumatic insulin resistance.

Adipocytes↗
PubMed2001

Proteolytic cleavage product of 30-kDa adipocyte complement-related protein increases fatty acid oxidation in muscle and causes weight loss in mice.

Adipocyte complement-related protein (30 kDa) (Acrp30), a secreted protein of unknown function, is exclusively expressed in differentiated adipocytes; its mRNA is decreased in obese humans and mice. Here we describe novel pharmacological properties of the protease-generated globular head domain of Acrp30 (gAcrp30). Acute treatment of mice with gAcrp30 significantly decreased the elevated levels of plasma free fatty acids caused either by administration of a high fat test meal or by i.v. injection of Intralipid. This effect of gAcrp30 was caused, at least in part, by an acute increase in fatty acid oxidation by muscle. As a result, daily administration of a very low dose of gAcrp30 to mice consuming a high-fat/sucrose diet caused profound and sustainable weight reduction without affecting food intake. Thus, gAcrp30 is a novel pharmacological compound that controls energy homeostasis and exerts its effect primarily at the peripheral level.

Adipocytes↗
PubMed2001

Stabilizing insulin-like growth factor-I in poly(D,L-lactide-co-glycolide) microspheres.

This study aimed at developing a controlled drug delivery system for recombinant human insulin-like growth factor-I (IGF-I) for localized delivery in bone healing. IGF-I was microencapsulated into an end-group uncapped 14 kDa poly(D,L-lactide-co-glycolide) 50:50 (PLGA 50:50) by solvent extraction from a W(1)/O/W(2) dispersion. Prior to encapsulation, IGF-I was exposed to ultrasonication in a water/dichloromethane dispersion, and its stability tested in the presence and absence of various excipients in the W(1) phase. HPLC and RIA were used for the assessment of IGF-I stability. Microencapsulated IGF-I was tested again for its structural intactness and also for in vitro release from various formulations containing appropriate co-encapsulated excipients. A specific fat cell assay was used to determine the biological activity of released IGF-I. Moderate ultrasonic treatment of aqueous IGF-I/dichloromethane mixtures caused approx. 50% IGF-I degradation. However, IGF-I was fully protected when bovine serum albumin, succinylated gelatin or poly(ethyleneglycol) were added to the aqueous IGF-I. Co-encapsulation of these excipients protected efficiently the protein upon microencapsulation. IGF-I release from microsphere formulations was sustained for up to 13 days featuring a moderately pulsatile pattern, depending on the microsphere composition. Typically, the amounts of IGF-I released within the first 24 h (burst) and during the second release pulse were in the order of 20 and 40%, respectively, of the total dose. The biological activity of released IGF-I was confirmed at selected time-points by the fat cell assay. In conclusion, the developed microspheres proved to be suitable to release biologically intact IGF-I over up to 13 days, a time-period considered to be relevant to promote bone fracture healing.

Adipocytes↗