Human keratinocyte (HK) motility plays an important role in the re-epithelialization of human skin wounds. Extracellular matrices (ECMs) and serum growth factors (GFs) are the two main stimuli that control HK migration. ECMs and GFs bind to their cognate receptors and activate distinct, yet overlapping, signaling networks. The SPECIFIC function of ECMs versus GFs in the control of HK migration remains unclear, Our preliminary studies indicate that ECMs, but not GFs, initiate migration. The ECM-induced migration, however, is partial and non-directional, while GFs' role appears to direct and optimize migration. Our hypothesis is that HK migration on connective tissue is initiated by ECMs, which work in concert with GFs to optimize the molility and provide directionality. Here, we propose to study the signaling mechanisms of ECM-initiated random motility and growth factor-optimized directional motility. The focus of these studies will be on the signal transduction by a collagen matrix without GFs (random migration) and by a collagen matrix plus GFs (directional and optimal migration). Specifically, we will: 1) study the role of the Rho family GTPases in HK migration by a collagen matrix in the presence or absence of GFs. Different Rho family GTPase members have distinct functions in the regulation of the actin cytoskeleton and cell migration. Their functions in HK motility are not clear. Both pharmacological and genetic approaches will be used to study these GTPases in HKs; 2) study how p38-MAPK and PKC-delta regulate random versus directional migration. Our recent findings show that p38-MAPK and PKC-delta are independently required for HK motility on a collagen matrix (in press). Here, we will further investigate the specific function of these two pathways in the integrin and the growth factor receptor signaling in HKs; 3) identify and characterize HK migration-linked genes by a novel """"""""TGF-beta block"""""""" approach. We will take advantage of the fact that TGF-beta blocks proliferation but not migration in HKs. cRNAs from TGF-beta- treated 1) non-migrating HKs, 2) randomly migrating HKs, and 3) directionally migrating HKs will be subjected to DNA microarray analysis. The microarray-identified genes will be further subjected to a """"""""pathway-screening"""""""" approach to narrow down the Rac1-p38-MAPK pathway- and the PKC-delta pathway-induced genes. These studies collectively will shed new light on the molecular mechanisms of wound re-epithelialization.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
1R01GM066193-01
Application #
6535001
Study Section
Surgery, Anesthesiology and Trauma Study Section (SAT)
Program Officer
Ikeda, Richard A
Project Start
2002-07-01
Project End
2006-06-30
Budget Start
2002-07-01
Budget End
2003-06-30
Support Year
1
Fiscal Year
2002
Total Cost
$281,531
Indirect Cost
Name
University of Southern California
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
041544081
City
Los Angeles
State
CA
Country
United States
Zip Code
90089
Guo, Jiacong; Jayaprakash, Priyamvada; Dan, Jian et al. (2017) PRAS40 Connects Microenvironmental Stress Signaling to Exosome-Mediated Secretion. Mol Cell Biol 37:
Zou, M; Bhatia, A; Dong, H et al. (2017) Evolutionarily conserved dual lysine motif determines the non-chaperone function of secreted Hsp90alpha in tumour progression. Oncogene 36:2160-2171
Dong, Hangming; Zou, Mengchen; Bhatia, Ayesha et al. (2016) Breast Cancer MDA-MB-231 Cells Use Secreted Heat Shock Protein-90alpha (Hsp90?) to Survive a Hostile Hypoxic Environment. Sci Rep 6:20605
Bhatia, Ayesha; O'Brien, Kathryn; Chen, Mei et al. (2016) Keratinocyte-Secreted Heat Shock Protein-90alpha: Leading Wound Reepithelialization and Closure. Adv Wound Care (New Rochelle) 5:176-184
Bhatia, Ayesha; O'Brien, Kathryn; Chen, Mei et al. (2016) Dual therapeutic functions of F-5 fragment in burn wounds: preventing wound progression and promoting wound healing in pigs. Mol Ther Methods Clin Dev 3:16041
Woodley, David T; Wysong, Ashley; DeClerck, Brittany et al. (2015) Keratinocyte Migration and a Hypothetical New Role for Extracellular Heat Shock Protein 90 Alpha in Orchestrating Skin Wound Healing. Adv Wound Care (New Rochelle) 4:203-212
Jayaprakash, Priyamvada; Dong, Hangming; Zou, Mengchen et al. (2015) Hsp90? and Hsp90? together operate a hypoxia and nutrient paucity stress-response mechanism during wound healing. J Cell Sci 128:1475-80
O'Brien, Kathryn; Bhatia, Ayesha; Tsen, Fred et al. (2014) Identification of the critical therapeutic entity in secreted Hsp90? that promotes wound healing in newly re-standardized healthy and diabetic pig models. PLoS One 9:e113956
Tsen, Fred; Bhatia, Ayesha; O'Brien, Kathryn et al. (2013) Extracellular heat shock protein 90 signals through subdomain II and the NPVY motif of LRP-1 receptor to Akt1 and Akt2: a circuit essential for promoting skin cell migration in vitro and wound healing in vivo. Mol Cell Biol 33:4947-59
Li, Wei; Tsen, Fred; Sahu, Divya et al. (2013) Extracellular Hsp90 (eHsp90) as the actual target in clinical trials: intentionally or unintentionally. Int Rev Cell Mol Biol 303:203-35

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