title: Effects of combined radiation and burn injury on the renin-angiotensin system.
abstract: The renin-angiotensin system (RAS) plays an important role in wound repair; however, little is known pertaining to RAS expression in response to thermal injury and the combination of radiation plus burn injury (CRBI). The purpose of this study was to test the hypothesis that thermal injury modifies expression of RAS components and CRBI delayed this up-regulation of RAS. Skin from uninjured mice was compared with mice receiving local thermal injury or CRBI (injury site). Skin was analyzed for gene and protein expression of RAS components. There was an initial increase in the expression of various components of RAS following thermal injury. However, in the higher CRBI group there is an initial decrease in AT(1b)  (vasoconstriction, pro-proliferative), AT(2)  (vasodilation, differentiation), and Mas (vasodilation, anti-inflammatory) gene expression. This corresponded with a delay and decrease in AT(1) , AT(2) , and MAS protein expression in fibroblasts and keratinocytes. The reduction in RAS receptor positive fibroblasts and keratinocytes correlated with a reduction in collagen deposition and keratinocyte infiltration into the wounded area resulting in a delay of reepithelialization following CRBI. These data support the hypothesis that delayed wound healing observed in subjects following radiation exposure may be in part due to decreased expression of RAS.
authors.affiliation: School of Pharmacy, University of Southern California, Los Angeles, California 90033, USA.
authors.forename: Sachin S
authors.initials: SS
authors.lastname: Jadhav
authors.forename: Natasha
authors.initials: N
authors.lastname: Sharma
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Meeks
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Mordwinkin
authors.forename: Theresa B
authors.initials: TB
authors.lastname: Espinoza
authors.forename: Norma R
authors.initials: NR
authors.lastname: Roda
authors.forename: Gere S
authors.initials: GS
authors.lastname: DiZerega
authors.forename: Colin K
authors.initials: CK
authors.lastname: Hill
authors.forename: Stan G
authors.initials: SG
authors.lastname: Louie
authors.forename: Kathleen E
authors.initials: KE
authors.lastname: Rodgers
mesh_terms: D047228:Angiotensin II Type 1 Receptor Blockers / Q000378:metabolism; D057912:Angiotensin II Type 2 Receptor Blockers / Q000378:metabolism; D000818:Animals; D002056:Burns / Q000378:metabolism* / Q000473:pathology; D003094:Collagen / Q000378:metabolism*; D004195:Disease Models, Animal; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D015870:Gene Expression; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D011833:Radiation Injuries, Experimental / Q000378:metabolism* / Q000473:pathology; D012084:Renin-Angiotensin System; D012867:Skin / Q000293:injuries / Q000378:metabolism* / Q000473:pathology; D015854:Up-Regulation; D014945:Wound Healing
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D057912:Angiotensin II Type 2 Receptor Blockers; D003094:Collagen