.infobox .infobox-protein
!!! Info
- Protein Name: Platelet-Derived Growth Factor Subunit B (PDGF-B)
- Gene: PDGFB
- UniProt: P01127
- Primary Receptor Bias: PDGFR-Beta Protein
- Subcellular Localization: Secreted extracellular growth factor
- Functional Axis: Pericyte recruitment, neurovascular stability, repair signaling
PDGF-B is a key PDGF ligand subunit that forms PDGF-BB homodimers or PDGF-AB heterodimers and strongly activates PDGFRB-dependent signaling.[1][2] In the CNS, this axis is foundational for pericyte recruitment, blood-brain barrier (BBB) maturation, and neurovascular homeostasis.[3][4] Because neurovascular failure is now recognized as an early and amplifying driver of cognitive and motor decline, PDGF-B has become a high-value mechanistic node in neurodegeneration research.[5][6]
PDGF-B is synthesized as a secreted dimerizing growth factor with receptor-binding surfaces that permit potent activation of PDGFRB-containing receptor complexes.[1:1][2:1] Relative to PDGF-A, PDGF-B has stronger pericyte-vascular biology coupling and is therefore more directly linked to BBB integrity and small-vessel resilience in adult brain.[3:1][4:1]
This receptor bias is central for translational planning: PDGF-B hypotheses are most defensible where vascular leakage, capillary rarefaction, or pericyte dysfunction contributes to disease progression.
Seminal developmental work showed that PDGF-B/PDGFRB signaling is required for proper pericyte coverage and BBB formation.[3:2] Experimental loss of pericyte support produces endothelial dysfunction, barrier leak, and secondary neuronal stress signatures.[3:3][4:2]
In aging brain, reduced pericyte support or signaling inefficiency contributes to BBB permeability, altered neurovascular coupling, and inflammatory amplification.[4:3][5:1] PDGF-B sits upstream of many of these changes via trophic support of mural-cell populations.
Beyond vessel stabilization, PDGF-BB can shift local tissue states toward survival and repair programs in injury models, including dopaminergic lesion paradigms relevant to Parkinson's disease.[7]
Human biomarker and imaging studies indicate BBB dysfunction is an early event in cognitive decline trajectories, and pericyte-injury signatures correlate with disease progression.[5:2][6:1] PDGF-B biology is mechanistically upstream of this phenotype, making it relevant for disease stratification and therapeutic design where neurovascular dysfunction co-occurs with amyloid/tau pathology.
Clinical translation has progressed furthest in PD, where intracerebroventricular PDGF-BB dosing has shown feasibility and acceptable early safety in small human studies.[8] Preclinical data in 6-OHDA paradigms further support neurorestorative effects and pericyte-modulating actions.[7:1] Current evidence is still early-phase, but it establishes a clinically tractable path for trophic-factor investigation.
PDGF-B pathway dysfunction is also relevant to vascular cognitive impairment and small-vessel phenotypes where BBB compromise and microvascular remodeling are central pathomechanisms.[5:3][6:2]
Direct ligand administration is the most mature strategy, with proof-of-concept human safety data in PD.[8:1] Key open questions remain around dose-exposure relationships, target tissue penetration, and long-term efficacy.
Pharmacologic efforts to restore BBB integrity by modulating PDGF-family neurovascular signaling are advancing, including strategies that tune maladaptive PDGF-CC/PDGFR pathways in acute and chronic neurologic disease.[9]
The most realistic neurodegeneration use case is combination therapy: pair PDGF-B neurovascular support with proteinopathy-directed interventions, then monitor with multimodal biomarkers (CSF vascular markers, MRI permeability metrics, cognitive/motor endpoints).[5:4][6:3]
PDGF signaling is pleiotropic and proliferative, so chronic activation requires oncologic vigilance, vascular-event monitoring, and careful exclusion criteria in older populations with cancer or pro-fibrotic risk.[1:2][10] Translational programs should include predefined stop rules for edema, inflammatory exacerbation, and off-target proliferative signals.
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Tallquist M, Kazlauskas A. PDGF signaling in cells and mice. Cytokine & Growth Factor Reviews. 2004. ↩︎ ↩︎
Bell RD, Winkler EA, Sagare AP, et al. Pericytes are required for blood-brain barrier integrity during embryogenesis. Nature. 2010. ↩︎ ↩︎ ↩︎ ↩︎
Bell RD, Winkler EA, Singh I, et al. Pericytes control key neurovascular functions and neuronal phenotype in the adult brain and during brain aging. Neuron. 2010. ↩︎ ↩︎ ↩︎ ↩︎
Nation DA, Sweeney MD, Montagne A, et al. Blood-brain barrier breakdown is an early biomarker of human cognitive dysfunction. Nature Medicine. 2019. ↩︎ ↩︎ ↩︎ ↩︎ ↩︎
Bell RD, Winkler EA, Singh I, et al. APOE4 leads to blood-brain barrier dysfunction predicting cognitive decline. Nature. 2020. ↩︎ ↩︎ ↩︎ ↩︎
Funa K, et al. Platelet-derived growth factor-BB has neurorestorative effects and modulates the pericyte response in a partial 6-hydroxydopamine lesion mouse model of Parkinson's disease. Neurobiology of Disease. 2016. ↩︎ ↩︎
Paul G, Zachrisson O, Varrone A, et al. Safety and tolerability of intracerebroventricular PDGF-BB in Parkinson's disease patients. Journal of Clinical Investigation. 2015. ↩︎ ↩︎
Su EJ, et al. Pharmacological targeting of the PDGF-CC signaling pathway for blood-brain barrier restoration in neurological disorders. Trends in Pharmacological Sciences. 2016. ↩︎
Sullivan AM, O'Keeffe GW. Trophic factors for Parkinson's disease: Where are we and where do we go from here?. European Journal of Neuroscience. 2019. ↩︎