Aging affects nearly every part of the body, including our bones.
As people age, bones become thinner, weaker, and more prone to fractures. Recovery also takes longer, making broken bones a serious health concern for many older adults.
Now, researchers in Germany have uncovered clues about why bones lose strength with age. Their findings may also point to a way to slow or even reverse some of those changes.
Why Bones Become More Fragile With Age
Scientists at the Max Planck Institute for Biology of Aging and the CECAD Cluster of Excellence for Aging Research at the University of Cologne focused on stem cells found in bone marrow.
These mesenchymal stem cells, or MSCs, help produce bone, cartilage, and fat cells.
The team wanted to understand why these cells become less effective as we age.
Their research centered on epigenetics, a system that controls gene activity without changing the underlying DNA sequence.
You can think of epigenetics as a set of switches that turn genes on or off.
As stem cells age, those switches can change.
The researchers compared bone marrow stem cells from young and older mice. They found significant age-related changes in the cells’ epigenomes.
Many of the affected genes play important roles in bone formation and maintenance.
Rejuvenating Bone Stem Cells
Lead researcher Dr. Andromachi Pouikli said the team wanted to understand why aging stem cells produce less bone tissue and contribute to increasing fat accumulation in the bone marrow.
To test whether they could reverse those changes, the researchers treated bone marrow stem cells with a solution containing sodium acetate.
The treatment altered the cells’ epigenetic landscape and improved access to genes involved in bone production.
The results were striking.
The treated stem cells became more active and produced more bone cells.
“This treatment impressively caused the epigenome to rejuvenate, improving stem cell activity and leading to higher production of bone cells,” Pouikli said.
The findings suggest that age-related changes in stem cells may not be permanent. In some cases, researchers may be able to restore more youthful function.
Could the Same Approach Work in People?
The team also wanted to know whether similar changes occur in humans.
To answer that question, they analyzed bone marrow stem cells collected from patients who underwent hip surgery.
The researchers found the same age-related epigenetic changes seen in mice.
That discovery strengthens the possibility that similar biological processes contribute to bone aging in people.
However, researchers caution that the work remains in its early stages.
The study did not test sodium acetate treatments in people, and many questions remain about safety, effectiveness, and long-term outcomes.
A Potential New Approach to Healthy Aging
Although this research is still preliminary, it offers valuable insight into how aging affects stem cells and bone health.
Rather than focusing solely on the symptoms of aging bones, the study explores the underlying biological mechanisms that drive those changes.
If future studies confirm these findings, researchers may eventually develop therapies that help maintain stronger bones later in life.
Such treatments could reduce fractures, improve mobility, and help older adults remain independent for longer.
For now, the study provides an encouraging glimpse into how stem cell and aging research may one day help address one of the most common challenges of growing older.
The findings were published in the journal Nature Aging.
Mechenchyma stem cells (MSCs) capable of self renewal and differentiation into variety of cell types. As they have low immunogenicity and can be safely transplanted autologously or allogenically. Thus, MSCs have many potential applications in cell-based therapy for various of disease states. However, MSCs of elderly people tend to gradually lose their regenerative potential with a concomitant increase in cellular dysfunction and replicative exhausted are considered hallmarks of aging. The inability of MSCs proliferate infinitely may undergo a limited number of population doubling before becoming senescent. Therefore, cells from age of donors are poor performance with reduced proliferative capacity and differentiation potential form a major factor to determine the lifespan and quality of MSCs. In addition, MSCs acquire senescent phenotype tend to loss their stem cell characteristics and stop from dividing, this pose negative impacts on immunomodulatory and differentiation capacity leading to reduce efficacy followong administration. As a result of DNA replication errors and exposure to endogenous or exogenous mutagens may cause DNA damage. The accumulation of DNA damage may induce irreversible cell cycle arrest and onset of senescent. The process of senescent cause mitochondria dysfunction and increase production of ROS which may induce DNA damage and accelerate telomere erosion. The absence of efficient repair mechanisms in DNA mitochondria (mtDNA) may increase mutation rate of mtDNA compared to nuclear DNA. Mitochondria has important roles in cellular function, it involves energy production, intracellular homeostasis, calcium balance and metabolisms. The impair on DNA repairing capacity of mitochondria cause most of the neurodegenerative diseases in elderly population.
There are several strategies to rejuvenate senescent MSCs: 1)iPSC derived MSCs can be passaged more than 40 times without exhibiting features of senescent. They retain donor-specific DNA replication profile while tissue -specific senescent associated with age–related patterns are erased during reprogramming. 2)Modulated through several key signaling molecules. Mitochondria SIRTs act as stress sensors and regulate protein networks to coordinate the stress responses. Overexpression of SIRTs as a potential strategy to prevent MSCs from aging 3)Genetics engineering to slow MSCs aging. Ectopic expression of telomerase reverse transcriptase in MSCs extend their replicative lifespan, preserved a normal karyotype, promote telomere elongation and abolished senensent without loss of differentiation potential. 4)Pharmacologic approaches and cytokine supplementation for delaying senescent. The restoring cytosolic acetyl-CoA levels by acetate supplementation to rescue the osteogenesis defects of elderly.
All cells require growth factors for survival, growth, differentiation and behavior. The removal of growth factor from a dependent cell does not always result in simple growth arrest but can in some cases lead to the rapid initiation of cellular program of self-destruction or apoptosis. Given the basic conditions for survival, subsequent growth factor-mediatd cell responses involve changes in proliferative activity, differentiation state, or behavior practice. Lack of growth factors may halt the development state of cell, alteration the availability of stimuli, the level of functional receptors, the composition of signaling transduction network, or the response capability of ultimate targets of signal transduction. Therefore, the precipitation of cellular program in cell has great impact in the generation of transformed phenotype such as senescent of cells and hence of cancer. As men and women attain the stage of menopause, lack of growth factors and growth hormones are cause of concern to alter the integrity of cells and generate many kinds of severe illnesses and diseases. The healthy lifestyle, diets and nutrition supplemention may provide additional support to improve the health of cells for functioning.