# Local positive-function contrast; not a new production module.
name: Example - Senescent fibroblast secretory activity in wound repair
category: Module
description: >-
  A review-grounded illustration showing why a SASP node should have explicit
  biological context. This is a physiological cutaneous-wound example, not a
  universal disease mechanism or a human intervention recommendation.
notes: >-
  Source-status caveat added during follow-up: the underlying Demaria et al.
  mouse study (PMID:25499914) has a 2026 Expression of Concern
  (PMID:42412492; DOI:10.1016/j.devcel.2026.04.004). This fixture retains the
  review's reported claim to illustrate actor and context representation.
  It is not a clean positive-evidence benchmark and must not be promoted into
  production as an established mechanism without assessing that notice and
  independent supporting evidence. Exact-snippet validation does not establish
  the reliability of the underlying experiment.
pathophysiology:
- name: Senescent fibroblast PDGF-AA secretion in acute wounds
  biological_scale: CELLULAR
  description: >-
    In the acute cutaneous wound context summarized by Shakur et al.,
    senescent fibroblasts secrete PDGF-AA, promoting myofibroblast differentiation.
  cell_types:
  - preferred_term: senescent skin fibroblast
    term:
      id: CL:0002620
      label: skin fibroblast
    located_in:
      preferred_term: skin of body
      term:
        id: UBERON:0002097
        label: skin of body
  biological_processes:
  - preferred_term: cellular senescence
    term:
      id: GO:0090398
      label: cellular senescence
  downstream:
  - target: Myofibroblast differentiation during wound repair
    description: >-
      PDGF-AA from the senescent fibroblast population promotes differentiation
      of a separate, non-senescent fibroblast population. Senescence is not
      transferred to the responding cells by this edge.
    evidence:
    - reference: PMID:42518598
      supports: SUPPORT
      quote_role: REVIEW_SYNTHESIS
      evidence_source: OTHER
      snippet: >-
        In acute cutaneous wounds, senescent fibroblasts secrete PDGF-AA to
        promote differentiation of non-senescent fibroblasts into myofibroblasts,
        which are essential in driving wound contraction and collagen production
      explanation: >-
        Page 3, Immune-mediated clearance of senescent cells. This records the
        review's synthesis; it does not turn that review into primary human
        evidence. Demaria et al. (2014) is the underlying study to curate before
        promoting this example into a disease-specific entry.
- name: Myofibroblast differentiation during wound repair
  biological_scale: CELLULAR
  description: >-
    The responding non-senescent fibroblasts differentiate into myofibroblasts
    in a repair context. This downstream population is not asserted to be
    senescent, and repair is not automatically classified as pathological fibrosis.
  cell_types:
  - preferred_term: responding skin fibroblast
    term:
      id: CL:0002620
      label: skin fibroblast