When the Body Can’t Finish Repair: How Mitochondrial Energy May Link ECM Aging and Chronic Tissue Damage

Aging research often focuses on what happens inside cells—DNA damage, epigenetic clocks, or cellular senescence. But another major dimension of aging lies outside the cell, in the structure that holds tissues together: the extracellular matrix (ECM).

In recent years, researchers such as Mikołaj Ogrodnik have emphasized that aging tissues increasingly resemble a wound that never fully heals. In these tissues, we see persistent inflammation, remodeling of the extracellular matrix, fibrosis, and altered stem-cell niches. These features suggest that aging may involve a chronic repair program that fails to resolve.

This perspective shifts attention from purely intracellular mechanisms toward the microenvironment of tissues—especially the ECM. But it also raises an important question:

Why does tissue repair fail to resolve with age?

A possible answer may lie deeper—in the bioenergetic capacity of cells, particularly in the function of mitochondria.

Aging as a Tissue-Level Problem

The extracellular matrix is the structural scaffold of tissues. It consists of proteins such as collagen, elastin, and proteoglycans that provide:

• mechanical support

• signaling cues to cells

• stem-cell niche regulation

• immune and repair signaling.

With aging, this matrix undergoes striking changes:

• collagen fragmentation

• fibrosis

• increased stiffness

• chronic ECM remodeling.

These ECM alterations influence nearly every aspect of tissue function—from stem-cell renewal to immune responses.

In Ogrodnik’s work and related discussions of aging as a “wound that does not heal,” ECM deterioration is seen not merely as passive damage but as part of an ongoing repair response that never fully resolves.

Repair Is an Energy-Intensive Process

What is sometimes overlooked is that tissue repair is metabolically expensive.

Repairing the ECM requires:

• collagen synthesis

• fibroblast activation

• matrix remodeling

• angiogenesis

• immune regulation.

All of these processes require large amounts of ATP, redox balance, and metabolic intermediates, most of which ultimately come from mitochondrial metabolism.

This suggests a deeper possibility:

Aging tissues may fail to complete repair not only because of damage—but because the metabolic capacity needed to resolve that damage gradually declines.

The ERM Perspective: Bioenergetic Throughput

The Exposure-Related Malnutrition (ERM) framework proposes that chronic environmental and metabolic stressors gradually place increasing demands on the body’s bioenergetic systems.

Over tim,e this can produce mitochondrial throughput limitation—a state where the capacity of mitochondria to process substrates and generate energy becomes constrained.

When this happens, cells shift toward survival and adaptation rather than full repair.

This shift could explain many features of aging biology, including:

• cellular senescence

• epigenetic remodeling

• stem-cell dysfunction.

But it may also help explain ECM aging.

How Mitochondrial Metabolism Connects to ECM Remodeling

Several metabolic pathways directly link mitochondrial function to extracellular matrix production.

1. Proline metabolism and collagen synthesis

Collagen—the most abundant protein in the ECM—is extremely rich in proline and hydroxyproline.

Proline synthesis depends on mitochondrial metabolism because:

• it derives from glutamine and glutamate metabolism

• it requires mitochondrial redox balance

• it depends on NADH/NADPH availability.

When mitochondrial metabolism is altered, proline availability and collagen synthesis change as well.

This links mitochondrial redox metabolism directly to ECM production.

2. TCA cycle intermediates control collagen maturation

Collagen stabilization requires the enzyme prolyl hydroxylase, which depends on the metabolite α-ketoglutarate.

α-ketoglutarate is a central intermediate of the mitochondrial TCA cycle.

Thus, mitochondrial metabolism influences not only collagen production but also collagen maturation and ECM stability.

3. Redox balance influences fibroblast behavior

Fibroblasts—the cells that produce ECM—are highly sensitive to metabolic state.

Changes in mitochondrial redox balance can alter:

• fibroblast activation

• inflammatory signaling

• fibrosis pathways.

This emerging field is sometimes described as the metabolic control of fibrosis, highlighting how metabolic programs determine ECM remodeling.

A Possible Bioenergetic Explanation for ECM Aging

Putting these observations together suggests a multi-level process:

1. Chronic exposures increase metabolic demand.

2. Mitochondrial throughput gradually becomes constrained.

3. Energy available for full tissue repair declines.

4. ECM remodeling becomes incomplete.

5. Fibrosis and matrix degradation accumulate.

6. The tissue enters a chronic wound-like state.

This framework aligns remarkably well with the ECM-centered perspective emphasized by Ogrodnik and others.

In other words:

The extracellular matrix may reveal the structural footprint of deeper metabolic stress.

A Self-Reinforcing Loop

Once ECM structure begins to deteriorate, further consequences follow.

ECM degradation alters:

• stem-cell niches

• mechanical signaling

• immune activation.

These changes can amplify inflammation and metabolic demand, creating a feedback loop between tissue structure and cellular metabolism.

This loop may help explain why aging tissues often show:

• chronic inflammation

• fibrosis

• impaired regeneration.

Bridging Cellular Aging and Tissue Aging

Much of aging research focuses on cellular hallmarks such as:

• senescence

• epigenetic drift

• mitochondrial dysfunction.

At the same time, tissue-level studies highlight:

• ECM remodeling

• fibrosis

• altered microenvironments.

These two perspectives are often studied separately.

However, mitochondrial bioenergetics may provide a bridge between them.

Mitochondria influence the metabolic pathways that supply the building blocks for ECM repair. When mitochondrial throughput becomes constrained, tissue repair processes may stall—leaving behind the structural patterns of aging.

A New Way to Think About Aging

Seen from this perspective, aging may not simply be the accumulation of damage.

Instead, aging tissues may represent systems trying to repair themselves under conditions of declining bioenergetic capacity.

The extracellular matrix then becomes the visible record of this struggle—a structure continuously remodeled but never fully restored.

In that sense, Ogrodnik’s vision of aging as a wound that does not heal may reflect not only tissue damage, but also the limits of the body’s metabolic capacity to complete repair.

References:

Ogrodnik, M. Aging: the wound that never starts healing. Nat Commun 16, 8732 (2025). https://doi.org/10.1038/s41467-025-64462-3

Ogrodnik, M., Gladyshev, V.N. The meaning of adaptation in aging: insights from cellular senescence, epigenetic clocks and stem cell alterations. Nat Aging 3, 766–775 (2023). https://doi.org/10.1038/s43587-023-00447-5