Journal September 26, 2026 4 min read

What markers track cellular senescence?

Cellular senescence is tracked through a panel of markers rather than a single readout: cell-cycle arrest proteins, DNA damage response factors, and the senescence-associated secretory phenotype. This page summarises the

peptides-pro Editorial

Cellular senescence is a stress response defined by irreversible cell-cycle arrest, and it is tracked in the laboratory through a panel of markers rather than a single readout. The core marker classes are cell-cycle arrest proteins (p16, p21), DNA damage response factors (ATM and its phosphorylation state), and the senescence-associated secretory phenotype (SASP), a secreted mixture of inflammatory cytokines, chemokines, growth factors, and matrix-remodeling enzymes [4]. Senescence is triggered by age-associated insults including ionizing radiation and natural aging, and it occurs heterogeneously across organs [1].

The mechanistic work centres on the DNA damage response kinase ATM and its upstream regulators, with additional senescence-relevant signalling through the AMPK pathway, the GATA4–NF-κB axis, and mitochondrial fission regulators of the DRP1 family [1][7][10][11].

Research Studies

LSD1 and ATM demethylation in aged organs and senescent cells

Lysine-specific demethylase 1 (LSD1) was reported to be upregulated in aged organs and in senescent cells. In response to natural aging or ionizing radiation-induced DNA damage, LSD1 interacted with and demethylated ATM at lysine 3,016, a modification confirmed using a newly generated ATM-K3016me antibody. This modification sustained ATM phosphorylation, amplified DNA damage signalling, and promoted senescence and organ aging [1].

p16 and p21 as cell-cycle arrest markers in senescence

Irreversible cell-cycle arrest is the defining feature of the senescent state, and arrest-associated proteins are the most widely used markers for it. In the senescence literature reviewed for cancer progression, arrest is described alongside immune surveillance and paracrine signalling as one of the three routes by which senescent cells influence their environment [4].

SASP and remodeling of the tumor microenvironment

SASP comprises inflammatory cytokines, chemokines, growth factors, and matrix-remodeling enzymes that regulate the tumor microenvironment. The reviewed evidence describes SASP induction mechanisms and condition-dependent roles in cancer, and notes emerging strategies targeting senescent cells and SASP signalling [4].

ETS1/DRP1 and nucleus pulposus cell senescence in intervertebral disc degeneration

In human nucleus pulposus cells (NPCs), ETS proto-oncogene 1 (ETS1) was identified as a regulator of mitochondrial fission. ETS1 was upregulated in severe human intervertebral disc degeneration (IVDD) and correlated with disc degeneration severity and NPC senescence. Inflammatory cytokines induced ETS1 upregulation, which directly bound to the dynamin 1-like (DNM1L, encoding DRP1) promoter [7].

Nebivolol and TGF-β1-dependent endothelial senescence in hypertension

Serum from patients with hypertension causes endothelial cell damage leading to senescence and a dysfunctional phenotype. In a study of 71 patients with newly diagnosed hypertension randomly assigned to amlodipine, nebivolol, or perindopril, serum samples collected before and 6 weeks after treatment were applied to endothelial cells in vitro to assess angiogenic activity, cellular senescence, mitochondrial metabolism, and oxidative stress [8].

PQQ and mitochondrial function in skin aging models

Pyrroloquinoline quinone (PQQ) is a redox-active ortho-quinone that can participate in repeated redox cycling, protect mitochondrial function, and activate signalling associated with mitochondrial biogenesis. Mitochondrial dysfunction is described as a contributor to intrinsic skin aging, photoaging, cellular senescence, impaired extracellular-matrix homeostasis, dysregulated pigmentation, and delayed recovery after energy-based or minimally invasive procedures. The evidence base here is a narrative review of mechanistic basis and dermatologic evidence, and the authors identify major uncertainties [5].

Ergothioneine and OCTN1-dependent tissue retention

Ergothioneine (EGT) is a diet-derived sulfur-containing histidine derivative with antioxidant, anti-inflammatory, and cytoprotective properties. In humans, its absorption, tissue distribution, and long-term retention are mainly mediated by the organic cation transporter OCTN1, which may help explain its accumulation in metabolically active and stress-prone tissues. Experimental and clinical evidence links EGT to neurodegenerative, cardiovascular, metabolic, inflammatory, and age-related disorders, although its therapeutic value still requires confirmation in larger and longer-term clinical studies [3].

Bone aging as multiscale degeneration

Bone aging is described not merely as bone mass loss but as a multi-level, networked degenerative phenomenon spanning molecular, cellular, tissue, and system levels. At the macroscopic level it is characterized by declines in bone mass, microstructure, and biomechanical properties [2].

Marker comparison across senescence contexts

Marker or axis	Context in which reported	Model
LSD1 / ATM-K3016me	Aged organs, senescent cells, DNA damage response	Natural aging and ionizing radiation [1]
SASP	Tumor microenvironment remodeling	Review of cancer literature [4]
ETS1 / DRP1	Nucleus pulposus cell senescence, IVDD severity	Human NPCs [7]
TGF-β1-dependent senescence	Hypertension-induced endothelial dysfunction	Patient serum applied to ECs in vitro [8]
OCTN1-mediated retention	EGT tissue distribution	Human physiology review [3]

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