Skin

How cells respond, adapt & remember

12 October 2026

From plant stress biology to the science of skin longevity.

In biology, no process happens in isolation. And ageing is not the result of a single mechanism.

For years of scientific work I studied how plants respond to environmental stress, analysing adaptive mechanisms, the regulation of cellular processes, and the interdependencies between metabolic and signalling pathways.

I was particularly interested in how organisms react to changing environmental conditions, how they maintain internal balance, and why similar stimuli can elicit different biological responses.

That perspective became one of the foundations of how I approach the formulation of BOGDAO cosmetics.

01. SYSTEMS BIOLOGY

Everything Is Connected.

Systems biology analyses organisms as dynamic, multi-level networks of interacting elements — from DNA and RNA, through proteins and metabolites, to cells, tissues and whole organisms.

In the classical reductionist approach we study a single gene, enzyme or receptor. Systems biology asks a different question: how do thousands of interactions among these elements produce a given biological response?

A cell’s response to a stimulus is not a simple linear reaction. It is the result of complex regulatory networks, including:

• —Gene regulatory networks — networks that regulate gene expression.
• —Protein–protein interactions — interactions between proteins.
• —Metabolic networks — networks of metabolic conversions.
• —Cell signalling pathways — pathways that transmit signals.
• —Feedback and feedforward loops — mechanisms of feedback and feedforward regulation.

A cell does not only receive signals from the environment. It constantly interprets them, integrates them and translates them into a biological response.

Biological function emerges from interactions, not isolated components.

02. HOMEOSTASIS & BIOLOGICAL RESILIENCE

The Science of Maintaining Balance.

Homeostasis is an organism’s ability to maintain relatively stable internal conditions despite changes in its surroundings.

It does not, however, mean biological invariance.

Living systems operate in a state of dynamic equilibrium, continually adjusting enzyme activity, energy metabolism, gene expression and immune responses to current needs.

Feedback mechanisms are central.

Negative feedback loops limit deviations from a given physiological state, stabilising the system. Positive feedback loops can amplify a response, allowing certain processes to start quickly — but in some conditions they can also lead to excessive activation.

In skin biology, homeostasis includes, among other things, maintaining the epidermal barrier, lipid balance, appropriate pH, hydration, the microbiome and a controlled inflammatory response.

Closely linked to homeostasis is biological resilience — the ability of a biological system to preserve function, respond to disturbance and recover equilibrium.

In the context of skin longevity, then, the point is not only how the skin looks, but also how it keeps its function over time.

03. CELLULAR STRESS & HORMESIS

When Stress Becomes a Biological Signal.

Cellular stress is not always a negative phenomenon.

Under certain conditions a small, transient stressor can switch on adaptive mechanisms that increase a cell’s capacity to cope with later challenges.

This is known as hormesis.

In plant cells, environmental stress — UV radiation, drought, salinity or temperature swings — can change the concentrations of reactive oxygen species (ROS), calcium ions and phytohormones.

ROS are not only products of oxidative damage. In controlled amounts they also act as signalling molecules, participating in the activation of defence responses.

A cell may switch on antioxidant enzymes, protective proteins, repair mechanisms and metabolic shifts.

When the intensity of stress exceeds adaptive capacity, however, the same mechanisms can lead to damage of proteins, lipids and DNA.

The biological response depends on the dose, duration and context of stress.

This principle also matters for skin biology. The skin’s capacity to adapt is finite, which is why chronic irritation, excessive exfoliation and prolonged UV exposure should not be equated with beneficial hormesis.

04. EPIGENETICS

How Cells Respond and Remember.

Epigenetics studies mechanisms that regulate gene activity without changing the DNA sequence itself.

They include, among others, DNA methylation, histone modifications and changes in chromatin organisation.

These mechanisms affect the accessibility of genetic information and can change how a cell responds to environmental signals.

In plant biology a particularly interesting phenomenon is stress memory.

After exposure to a given stimulus, some regulatory changes can persist after it has ended. As a result, later contact with similar conditions can elicit a different response — sometimes faster or stronger.

Not every stress memory is epigenetic, however, and not every epigenetic change is stable or heritable.

In human biology, epigenetic regulation plays an essential role in cell differentiation, the maintenance of cell identity and the response to environmental factors.

EPIGENETIC AGING

With age, patterns of DNA methylation and chromatin organisation change.

On the basis of specific methylation changes, so-called epigenetic clocks have been developed, used in research to estimate biological age and to analyse ageing processes.

This does not mean that a cosmetic can automatically reverse the epigenetic age of the skin. Such a claim would require direct molecular studies.

05. CELLULAR SENESCENCE & SKIN LONGEVITY

Understanding the Biology of Aging.

Skin ageing is a multifactorial process, involving changes in cellular metabolism, mitochondrial function, genome stability, cell-to-cell communication and the structure of the extracellular matrix.

One important mechanism is cellular senescence.

Senescent cells are in a state of permanent or long-term cell-cycle arrest, yet they often remain metabolically active.

Some of them produce a characteristic profile of signalling molecules known as SASP — the Senescence-Associated Secretory Phenotype.

It can include pro-inflammatory cytokines, chemokines, growth factors and enzymes that act on the extracellular matrix, including metalloproteinases.

Depending on context, senescence can serve protective functions, among them limiting the proliferation of damaged cells. Chronic accumulation of senescent cells and persistent SASP signalling, however, can contribute to tissue ageing.

In the skin these processes can affect fibroblast function, collagen and elastin metabolism, and communication between the epidermis and the dermis.

Skin longevity is not simply about slowing visible aging. It is about understanding the biological mechanisms that maintain tissue function over time.

06. MITOCHONDRIAL FUNCTION & OXIDATIVE STRESS

Energy, Signalling and Cellular Adaptation.

Mitochondria are not only structures responsible for producing ATP.

They also take part in the regulation of metabolism, redox signalling, calcium homeostasis and the cellular stress response.

With age, changes can occur in mitochondrial function, organelle quality control and the cell’s ability to maintain energy and redox balance.

Reduced efficiency of energy production, increased ROS production and weakened repair mechanisms can affect the metabolism of fibroblasts and keratinocytes, and the quality of the extracellular matrix.

At the same time, mitochondria participate in cellular signalling. Disturbed mitochondrial function is not only an energy problem — it changes how a cell interprets stress and decides on adaptation, repair or senescence.

Cellular energy and cellular signalling cannot be separated.

In formulation, that means caution toward promises of “energising mitochondria” without a mechanistic basis. What interests us is the environment in which a cell can maintain redox homeostasis — not stimulation at any cost.

07. FROM PLANT STRESS BIOLOGY TO FORMULATION

Why this knowledge changes how we design skincare.

At BOGDAO we do not treat the skin as a set of isolated receptors that can be “switched on” by a single ingredient. We treat it as a system: barrier, microbiome, metabolism, signalling and a biological memory of earlier experience.

That is why what matters is not only the presence of an active, but its dose, context, pH, emulsion structure and interactions with the rest of the formula.

The point is not to push the limits of the skin’s tolerance. The point is to support its physiology — with the same precision used to analyse networks of dependence in systems biology.

We do not try to override skin biology. We try to work with it.

Marta Bogdał

Founder & Formulation Scientist, BOGDAO