Related Experiment Video

Updated: May 11, 2026

In Situ Immunofluorescent Staining of Autophagy in Muscle Stem Cells
08:35

In Situ Immunofluorescent Staining of Autophagy in Muscle Stem Cells

Published on: June 12, 2017

Suppression of autophagy in osteocytes mimics skeletal aging

Melda Onal1, Marilina Piemontese, Jinhu Xiong

  • 1Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA.

The Journal of Biological Chemistry
|May 7, 2013
PubMed

Insights

Autophagy, a cellular recycling process, is crucial for maintaining bone mass. Suppressing autophagy in bone cells mimics aging, leading to reduced bone density and increased bone fragility.

Area of Science:

  • Cell Biology
  • Bone Biology
  • Aging Research

Background:

  • Bone mass naturally decreases with age, but the underlying mechanisms are not fully understood.
  • Autophagy is a vital cellular process for maintaining cellular health and homeostasis.
  • Osteocytes, the primary cells within bone, play a critical role in bone remodeling and maintenance.

Purpose of the Study:

  • To investigate the role of autophagy in osteocytes in regulating bone mass.
  • To determine if impaired autophagy in osteocytes contributes to age-related bone loss.

Main Methods:

  • Conditional deletion of the Atg7 gene (essential for autophagy) in mouse osteocytes.
  • Analysis of bone mass, microarchitecture, and cellular activity (osteoblasts and osteoclasts) in genetically modified mice.
  • Assessment of oxidative stress markers in bone tissue.

Main Results:

  • Deletion of Atg7 in osteocytes led to significantly reduced bone mass and altered bone microarchitecture (decreased cancellous bone volume and cortical thickness, increased porosity).
  • These bone changes were associated with reduced osteoblast and osteoclast numbers and decreased bone formation rates.
  • Elevated levels of oxidative stress markers were observed in the bones of mice with impaired autophagy in osteocytes.

Conclusions:

  • Suppression of autophagy in osteocytes significantly impacts bone mass and structure, mimicking many aspects of age-related bone loss.
  • A decline in autophagy within osteocytes may be a contributing factor to the reduced bone mass observed during aging.
  • Targeting autophagy in osteocytes could represent a potential therapeutic strategy for age-related bone diseases.
Keywords:
AgingAutophagyBoneMouseOsteocyteRemodeling

Related Concept Videos

Bone Disorders01:29

Bone Disorders

Aging and its effect on bone remodeling is the most common cause of bone disorders. In young and healthy people, bone deposition and resorption happen at an equal rate to maintain optimal bone health.
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...
Osteoclasts in Bone Remodeling01:31

Osteoclasts in Bone Remodeling

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 bone...
Bone Remodeling01:40

Bone Remodeling

Bone remodeling is a continuous and balanced process of bone resorption by osteoclasts and bone formation by osteoblasts. In adults, it helps maintain bone mass and calcium homeostasis. While mechanical stress can stimulate turnover as part of the normal maintenance and reparative process, several hormones also regulate bone remodeling.
The Effect of Aging on Tissues01:19

The Effect of Aging on Tissues

Several body functions deteriorate with age. The external signs of aging are easily identifiable. For example, the skin becomes dry, less elastic, and thins out, forming wrinkles. The skin of the face begins to appear looser due to a decrease in the levels of elastic and collagen fibers in the connective tissue. Additionally, melanin production in the hair follicle decreases with age, resulting in gray hair. Moreover, the senses of sight and hearing decline, so glasses and hearing aids may...
Autophagy01:27

Autophagy

Autophagy is a self-digesting process by which a cell protects itself from threats both within and outside the cell, ranging from abnormal proteins to invading bacteria. In this process, obsolete components of the cell and invading microbes are degraded by hydrolytic enzymes active in an acidic environment of the lysosomal lumen.
An autophagic pathway consists of a series of signaling events activated in response to diverse stress and physiological conditions such as food deprivation,...
Autophagic Cell Death01:18

Autophagic Cell Death

Christian de Duve discovered “autophagy,” a process in which cellular components are engulfed by membrane-bound organelles called autophagosomes. The autophagosomes then fuse with lysosomes to digest the enclosed contents. Autophagy is generally activated in cells to prevent cell death. However, cell death is triggered when the damage is beyond repair.
Autophagy and Apoptosis
Autophagy can activate apoptosis. In normal conditions, the autophagy activating protein Beclin-1 and pro-apoptotic...