Related Experiment Video
Updated: Jul 17, 2026
07:22
Isolation and Differentiation of Stromal Vascular Cells to Beige/Brite Cells
Published on: March 28, 2013
Resolving the Two "Bony" Faces of PPAR-gamma.
Beata Lecka-Czernik1, Larry J Suva
1Department of Geriatrics, Reynolds Institute on Aging, University of Arkansas for Medical Sciences, 629 Jack Stephens Drive, Little Rock, AR 72205, USA.
PPAR Research
|January 30, 2007
Summary
Aging bone loss stems from imbalanced bone turnover. Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) drives fat cell formation and hinders bone growth, impacting bone mass.
Area of Science:
- Bone biology and aging research.
- Cellular and molecular mechanisms of bone homeostasis.
- Mesenchymal stem cell differentiation pathways.
Background:
- Aging is associated with bone loss due to reduced osteoblast and increased osteoclast activity.
- Bone marrow adipocytes increase with age, contributing to bone loss.
- Marrow mesenchymal stem cells (MSCs) differentiate into osteoblasts or adipocytes.
Purpose of the Study:
- To investigate the role of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) in regulating bone mass and marrow adiposity.
- To explore the mechanisms by which PPAR-gamma influences MSC lineage allocation.
- To understand the ligand-selective properties of PPAR-gamma in controlling bone and fat mass.
Main Methods:
- Analysis of bone turnover markers in aging bone.
- Investigating MSC differentiation in response to PPAR-gamma modulation.
- In vivo studies assessing bone mass and marrow fat content under varying PPAR-gamma activity.
Main Results:
- Increased PPAR-gamma activity in vivo promotes marrow adipocyte formation and leads to bone loss, mimicking age-related changes.
- Decreased PPAR-gamma activity results in increased bone mass.
- Evidence suggests PPAR-gamma's pro-adipocytic and anti-osteoblastic effects are ligand-dependent.
Conclusions:
- PPAR-gamma is a key regulator of bone mass and marrow fat accumulation.
- Modulating PPAR-gamma activity offers a potential therapeutic strategy for age-related bone loss.
- Ligand-specific interactions of PPAR-gamma present multifaceted mechanisms controlling bone and fat homeostasis.
Related Concept Videos
01:16TGF - β Signaling Pathway
The TGF-β signaling pathway regulates cell growth, differentiation, adhesion, motility, and development. TGF-β ligands that induce TGF-β signaling are synthesized in their latent form. Several proteases or cell surface receptors such as integrins act upon the latent form, releasing the active ligand. There are three types of mammalian TGF-βs: (TGF-β1, TGF-β2, and TGF-β3) that bind as homodimers or heterodimers to TGF-β receptors. The TGF-β receptors are of three kinds RI, RII, and RIII. The RI...
01:12GPCR Desensitization
G protein-coupled receptor (GPCR) signaling plays a crucial role in cell functioning. GPCR desensitization is an equally essential process. It allows cells to respond to changing environments and regain sensitivity to new stimuli while preventing unnecessary stimulation when no longer needed. Prolonged exposure to stimuli leads to GPCR desensitization. It involves blocking the receptors from binding and activating additional G proteins. This inhibits activation of downstream effectors, thereby...
01:31Transducer Mechanism: Nuclear Receptors
Nuclear receptors, or NRs, are unique transcription factors that regulate gene transcription and affect the cellular pathways involved in reproduction, development, or metabolism. Their ability to be stimulated by small lipophilic ligands and control vital cellular processes makes them ideal drug targets. Nearly 10-15% of currently prescribed drugs target these receptors.
About 48 different soluble family members of nuclear receptors are identified that can be divided into two main classes:
About 48 different soluble family members of nuclear receptors are identified that can be divided into two main classes:
00:59The Parathyroid Glands
The two pairs of parathyroid glands embedded within the posterior surface of the thyroid gland are restricted by a dense capsule around them. These glands comprise two distinct cell populations—parathyroid oxyphil and parathyroid principal cells- pivotal in calcium homeostasis.
Oxyphil cells, whose functions remain elusive, emerge during late puberty, adding a layer of complexity to the parathyroid gland's intricacies. In contrast, principal parathyroid cells undertake a vital role by producing...
Oxyphil cells, whose functions remain elusive, emerge during late puberty, adding a layer of complexity to the parathyroid gland's intricacies. In contrast, principal parathyroid cells undertake a vital role by producing...
01:15G Protein-coupled Receptors
G Protein-Coupled Receptors or GPCRs are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to sensory stimuli such as light, odors, hormones, cytokines, or neurotransmitters.
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
01:09GPCRs Regulate Adenylyl Cylase Activity
Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of cells.
Two...
Two...