Our long-term goal is to decipher the extracellular signals that communicate across compartments to synchronize the key cells in the wound repair process. Healing requires orchestrated repopulation, regeneration, and maturation remodeling of the lost tissue, a process deficient in normal aging and numerous clinical situations including chronic ulcers and diabetes. Many of these defects occur due to failure of the wound to mature during the resolving phase. Key to this maturation is reversion of the exuberant fibroplasia and vascularity needed to heal the wounds, though the signals and mechanisms driving this are unknown. Soluble peptide factors, in addition to matrix components and other signaling elements, play major roles in wound bed signaling. During the current initial funding period, we found production late in the wound repair process of CXCR3 ligands (the ELR-negative chemokines IP-9/CXCL11 and IP-10/CXCL10). These blocked fibroblast motility by preventing rear release, thereby channeling the phenotype towards matrix contraction, and stopped endothelial cells from migrating and forming tubes in vitro and vasculature in vivo. We hypothesize that during wound repair, the CXCR3 signaling network functions in all phases, not only initiating post-wound contraction, but also triggering the resolving phase and the involution of the neovasculature and loss of fibroblasts necessary to form the mature, pauci-cellular dermis. We propose to test the following hypotheses, supported by initial experiments, to define the molecular mechanisms of these processes: I. That CXCR3 ligands are required for wound matrix maturation. We will use defined knockout mice and cell transplantation to examine wound bed matrix maturation. II. That CXCR3 signaling leads to vascular involution. The inductive role of IP-10 in vascular involution will be tested in animals, and the intracellular molecular basis will be probed in wounds. III. CXCR3 signaling reduces dermal cellularity. The molecular mode by which regenerative fibroplasia is reverted during the resolving phase will be defined in vitro and in vivo. IV. Specific CXCR3 ligands dictate distinct aspects of repair. An IP-9-devoid mouse model will determine the role of CXCR3 on basement membrane and upper dermal regeneration and a PF4-deficient mouse model will probe the basis of skin contraction that happens immediately upon wounding. These investigations will define key extracellular and intracellular molecules for wound resolution. These are potential targets for rationally designed interventions t promote normal wound healing and limit scarring.

Public Health Relevance

Failure to properly heal wounds results in significant morbidity and mortality in many patients, particularly those with diabetes, neuropathies, trauma and even those just advanced in years. Incomplete wound resolution predisposes to ulcers and skin disruption, while excessive repair results in scarring which impairs use and function. These investigations will define key extracellular and intracellular molecules that are potential targets for rationally designed interventions to promote normal wound healing and limit scarring.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM063569-08
Application #
8319496
Study Section
Special Emphasis Panel (ZRG1-SBIB-E (02))
Program Officer
Somers, Scott D
Project Start
2003-07-01
Project End
2014-08-31
Budget Start
2012-09-01
Budget End
2014-08-31
Support Year
8
Fiscal Year
2012
Total Cost
$334,092
Indirect Cost
$113,569
Name
University of Pittsburgh
Department
Pathology
Type
Schools of Medicine
DUNS #
004514360
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Bodnar, Richard J; Satish, Latha; Yates, Cecelia C et al. (2016) Pericytes: A newly recognized player in wound healing. Wound Repair Regen 24:204-14
Wells, Alan; Nuschke, Austin; Yates, Cecelia C (2016) Skin tissue repair: Matrix microenvironmental influences. Matrix Biol 49:25-36
Nuschke, Austin; Rodrigues, Melanie; Wells, Albin W et al. (2016) Mesenchymal stem cells/multipotent stromal cells (MSCs) are glycolytic and thus glucose is a limiting factor of in vitro models of MSC starvation. Stem Cell Res Ther 7:179
Nuschke, Austin; Rodrigues, Melanie; Rivera, Jaime et al. (2016) Epidermal Growth Factor Tethered to β-Tricalcium Phosphate Bone Scaffolds via a High-Affinity Binding Peptide Enhances Survival of Human Mesenchymal Stem Cells/Multipotent Stromal Cells in an Immune-Competent Parafascial Implantation Assay in Mice. Stem Cells Transl Med :
Yates, Cecelia C; Nuschke, Austin; Rodrigues, Melanie et al. (2016) Improved transplanted stem cell survival in a polymer gel supplemented with tenascin-C accelerates healing and reduces scarring of murine skin wounds. Cell Transplant :
Ma, Bo; Khazali, Ahmad; Wells, Alan (2015) CXCR3 in carcinoma progression. Histol Histopathol 30:781-92
Bodnar, Richard J; Wells, Alan (2015) Differential regulation of pericyte function by the CXC receptor 3. Wound Repair Regen 23:785-96
Stenger, Elizabeth O; Rosborough, Brian R; Mathews, Lisa R et al. (2014) IL-12hi rapamycin-conditioned dendritic cells mediate IFN-γ-dependent apoptosis of alloreactive CD4+ T cells in vitro and reduce lethal graft-versus-host disease. Biol Blood Marrow Transplant 20:192-201
Sekar, M C; Shahiwala, K; Leloup, L et al. (2014) Modulation of Epidermal Growth Factor Stimulated ERK Phosphorylation and Cell Motility by Inositol Trisphosphate Kinase. J Pharm Sci Pharmacol 1:160-164
Jamison, Joshua; Wang, James H-C; Wells, Alan (2014) PKCδ regulates force signaling during VEGF/CXCL4 induced dissociation of endothelial tubes. PLoS One 9:e93968

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