164 - Cross-Species Platelet Comparison To Inform Neonatal Transfusion Practices Reveals Developmentally Regulated Metabolism and Inflammation Pathways

Publication Number: 2158.164

Christopher Thom, CHOP/UPenn, Philadelphia, PA, United States; Xinyue Ma, University at Buffalo, BUFFALO, NY, United States; Henry A.. Feldman, Boston Children's Hospital, Boston, MA, United States; Kathleen E. McGrath, University of Rochester School of Medicine and Dentistry, Rochester, NY, United States; Preeti Maurya, University of Rochester, Rochester, NY, United States; Hossein Fazelinia, Childrens Hospital of Philadelphia, Philadelphia, PA, United States; Lynn A. Spruce, Children's Hospital of Philadelphia, Philadelphia, PA, United States; Daniel O'Reilly, University College Dublin, Dublin, Dublin, Ireland; James Palis, Golisano Children's Hospital at The University of Rochester Medical Center, Rochester, NY, United States; Craig N. Morrell, University of Rochester School of Medicine and Dentistry, Rochester, NY, United States; Martha Sola-Visner, Harvard Medical School, Boston, MA, United States; Donald E.. Mager, University at Buffalo, SUNY, Buffalo, NY, United States; Patricia Davenport, Boston Children's Hospital, Boston, MA, United States

Background: Liberal platelet transfusions paradoxically increase major bleeding and mortality in preterm infants. Recent proteomic data show developmental mismatches between neonatal and adult human platelets, suggesting that functionally hyperreactive adult platelets may disrupt preterm physiology (Thom & Davenport et al, JTH 2023). Preclinical models are essential to understand and manage this problem, but it remains unclear which developmentally altered platelet molecules and pathways in humans are conserved in mice.

Objective: We aimed to define proteins and pathways differing between neonatal and adult mouse platelets and identify developmentally regulated signatures consistent across mice and humans.

Design/Methods: Proteomes of resting neonatal and adult mouse platelets were analyzed by mass spectrometry (Fig. 1A). We applied sparse principal component analysis (sPCA) and TransPath-C, a machine learning-based cross-species pathway classifier (Carroll et al, Integr Biol 2021, Fig. 1B), to identify conserved developmental changes in mouse and human platelets.

Results: Among 2,889 quantified proteins, 157 differed between adult and neonatal mouse platelets (padj < 0.05, fold change>1.5). Adult platelets from both species were enriched for inflammatory molecules and pathways, including β2M and CXCL12 (Fig. 1C-D). Some functional markers diverged between species (e.g., P-Selectin increased in adult mouse platelets but not in humans). Given these discrepancies, we focused on pathways showing consistent developmental regulation.

sPCA and TransPath-C revealed conserved enrichment of growth factor (VEGF), inflammatory (IL6), platelet activation (GPVI), and metabolic (Krebs cycle) pathways in adult vs neonatal platelets (Fig. 1E). Neonatal platelets displayed greater Krebs cycle activity, while IL6 signaling predominated in adults, despite species-specific protein differences (e.g., ACO1, STAT5; Fig. 1F-G).

Conclusion(s): Clinically informative neonatal transfusion models must recapitulate developmental differences in platelet hemostatic and immune functions observed in humans. Our findings define molecular features distinguishing neonatal from adult platelets and identify cross-species pathways linked to platelet reactivity and inflammation. These conserved signatures highlight translationally relevant targets and provide a framework to align murine and human biology, improving the developmental and disease relevance of preclinical research.

Pathway comparison of mouse and human platelet proteomes reveals developmentally regulated changes conserved across species.
A. Principal component (PC) analysis of neonatal (Neo) and adult (Ad) murine platelet proteomes.
B. Schematic overview of the TransPath-C method.
C. Heat map depicting select protein abundance in human platelet samples. Proteins that were previously investigated in Thom & Davenport et al, JTH 2023 are highlighted with a red star.
D. Heat map depicting select protein abundance in murine platelet samples. Proteins that were previously investigated in Thom & Davenport et al, JTH 2023 are highlighted with a red star.
E. Pathways with non-zero loadings in sPC3. Salmon indicates pathway enrichment in adult platelets. Cyan indicates pathway enrichment in neonatal platelets.
F. KREB pathway comparison in human and mouse platelets. Red indicates higher protein abundance in neonatal platelets, blue indicates higher protein abundance in adult platelets.
G. Graphical representation of select proteins in the IL6 pathway. Red indicates higher protein abundance in neonatal platelets, blue indicates higher protein abundance in adult platelets.