Related Experiment Video
Updated: Apr 5, 2026
08:01
Stimulation of Notch Signaling in Mouse Osteoclast Precursors
Published on: February 28, 2017
8.5K
Telomerase activity promotes osteoblast differentiation by modulating IGF-signaling pathway
Hamid Saeed1,2, Weimin Qiu3, Chen Li4
1Molecular Endocrinology Laboratory (KMEB), Department of Endocrinology and Metabolism, Medical Biotechnology Center, Odense University Hospital & University of Southern Denmark, SDU, 5000, Odense C, Denmark. hamid.pharmacy@pu.edu.pk.
Biogerontology
|August 12, 2015
Summary
Telomere maintenance through telomerase is crucial for bone health. Impaired insulin-like growth factor (IGF) signaling due to telomerase deficiency reduces osteoblast function and bone formation.
Area of Science:
- Cell Biology
- Bone Biology
- Aging Research
Background:
- Telomerase activity's role in age-related bone decline is understudied.
- Previous work showed telomerase overexpression enhances osteoblast differentiation.
Purpose of the Study:
- Investigate signaling pathways of telomerase in osteoblastic cells.
- Elucidate telomerase's regulatory mechanisms in bone formation.
Main Methods:
- Comparative microarray and Western blot analysis of telomerase-overexpressing and primary human bone marrow skeletal stem cells (hMSC).
- Analysis of osteoblastic cells from telomerase-deficient (Terc(-/-)) mice.
- Assessment of insulin-like growth factor (IGF) signaling components and alkaline phosphatase (ALP) activity.
Main Results:
- Telomerase overexpression upregulated IGF signaling components in hMSC.
- Increased IGF-induced AKT phosphorylation and ALP activity observed in hMSC-TERT.
- Telomerase deficiency reduced IGF signaling, serum IGF1/IGFBP3, and skeletal IGF gene expression in mice.
- Impaired IGF1-induced osteoblast differentiation in Terc(-/-) MSC.
Conclusions:
- Impaired IGF/AKT signaling contributes to reduced bone mass in telomerase-deficient cells.
- Telomerase influences bone formation via the IGF signaling pathway.
Related Concept Videos
01:16TGF - β Signaling Pathway
11.0K
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...
11.0K
01:17Hormones and Bone Tissue
4.2K
The endocrine system produces and secretes hormones, which interact with the skeletal system. These hormones control bone growth, maintain bone once it is formed, and remodel it.
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...
4.2K
01:31Osteoclasts in Bone Remodeling
4.8K
Osteoclasts are cells responsible for bone resorption and remodeling. They originate from hematopoietic progenitor cells present in the bone marrow. Numerous progenitor cells fuse to form multinucleated cells, each with 10-20 nuclei. A single osteoclast has a diameter of 150 to 200 µM. These cells have ruffled borders that break down the underlying bone tissue and release minerals such as calcium into the blood in bone resorption. Osteoclasts cling to bones with their ruffled edges during...
4.8K
01:24Regulation of Angiogenesis and Blood Supply
4.0K
Rapidly dividing tumors, embryos, and wounded tissues require more oxygen than usual, lowering the oxygen concentration in the blood. At low oxygen or hypoxic conditions, an oxygen-sensitive transcription factor called the hypoxia-inducible factor 1 or HIF1 is activated. HIF1 is a dimeric protein of alpha (ɑ) and beta (β) subunits. Under optimal oxygen conditions, HIF1β is present in the nucleus while HIF1ɑ remains in the cytosol. HIF1ɑ is hydroxylated by prolyl...
4.0K
01:22PI3K/mTOR/AKT Signaling Pathway
6.4K
The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast, mTORC2 consists of a...
6.4K
02:41Telomeres and Telomerase
28.7K
In eukaryotic DNA replication, a single-stranded DNA fragment remains at the end of a chromosome after the removal of the final primer. This section of DNA cannot be replicated in the same manner as the rest of the strand because there is no 3’ end to which the newly synthesized DNA can attach. This non-replicated fragment results in gradual loss of the chromosomal DNA during each cell duplication. Additionally, it can induce a DNA damage response by enzymes that recognize single-stranded...
28.7K