Pericytes regulate vascular immune homeostasis in the CNS.
Level 5 - mechanism / opinion, no new human data
Preclinical animal model study (Pdgfb ret/ret mice) without human data.
PubMed 33653955 · doi:10.1073/pnas.2016587118
What was done
Researchers evaluated the role of vascular pericytes in regulating CNS leukocyte trafficking using adult pericyte-deficient mice (Pdgfb ret/ret) during homeostasis and experimental autoimmune encephalomyelitis (EAE). They tested whether mortality and neuroinflammation could be rescued using fingolimod or blocking antibodies against endothelial adhesion molecules (anti-VCAM-1 and anti-ICAM-1). They also crossed pericyte-deficient mice with myelin peptide-specific T-cell receptor transgenic mice (Pdgfb ret/ret; 2D2 tg) to assess spontaneous neuroinflammatory disease.
What was found
No quantitative values, exact sample sizes, or statistical figures were provided in the abstract. Pericyte deficiency inversely correlated with vascular permissiveness to leukocyte infiltration during homeostasis and inflammation. EAE induction in Pdgfb ret/ret mice resulted in lethal, atypical EAE that was reversed by fingolimod. Anti-VCAM-1 and anti-ICAM-1 antibodies reduced leukocyte infiltration and reduced symptom severity. Furthermore, Pdgfb ret/ret; 2D2 tg mice spontaneously developed neurological symptoms with massive leukocyte infiltration into the brain.
Why it matters
This study demonstrates that pericytes actively maintain CNS vascular immune quiescence. It establishes that intrinsic endothelial and perivascular dysfunction can directly drive susceptibility to autoimmune neuroinflammatory disorders.
Limits
The findings are derived exclusively from transgenic rodent models, limiting direct generalizability to human neuroinflammatory diseases like multiple sclerosis. The abstract reports no numerical data, confidence intervals, or sample sizes.
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