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Articles by J. E. Faber
Total Records ( 2 ) for J. E. Faber
  S Wang , H Zhang , X Dai , R Sealock and J. E. Faber
  Rationale:

Collaterals are arteriole-to-arteriole anastomoses that connect adjacent arterial trees. They lessen ischemic tissue injury by serving as endogenous bypass vessels when the trunk of 1 tree becomes narrowed by vascular disease. The number and diameter ("extent") of native (preexisting) collaterals, plus their amount of lumen enlargement (growth/remodeling) in occlusive disease, show remarkably wide variation among inbred mouse strains (eg, C57BL/6 and BALB/c), resulting in large differences in tissue injury in models of occlusive disease. Evidence suggests similar large differences exist among healthy humans.

Objective:

To identify candidate loci responsible for genetic-dependent collateral variation.

Methods and Results:

Cerebral collateral number and diameter were determined in 221 C57BL/6xBALB/c F2 progeny, followed by linkage analysis to identify quantitative trait loci (QTL) for collateral number and diameter. Four QTL were obtained for collateral number, including epistasis between 2 loci. A QTL that was identical to the strongest QTL for collateral number on chromosome 7 (logarithm of the odds [LOD]=29, effect size=37%) was also mapped for collateral diameter (LOD=17, effect size=30%). Chromosome substitution strain analysis confirmed this locus. We also obtained a unique QTL on chromosome 11 for collateral remodeling after middle cerebral artery occlusion. Association mapping within the chromosome 7 QTL interval using collateral traits measured for 15 inbred strains delineated 172-kbp (P=0.00002) and 290-kbp (P=0.0004) regions on chromosome 7 containing 2 and 7 candidate genes, respectively.

Conclusions:

We conclude that collateral extent and remodeling are unique, highly heritable complex traits, with 1 QTL predominantly affecting native collateral number and diameter.

  D Chalothorn and J. E. Faber
 

The extent (density and diameter) of the native (preexisting) collateral circulation in healthy tissues and the capacity of collaterals to enlarge/remodel in obstructive arterial disease are important determinants of ischemic injury. Evidence suggests that these parameters vary widely from yet-to-be-identified genetic and environmental factors. Recently, a locus on chromosome 7 was linked to less recovery of perfusion after femoral artery ligation in BALB/c and A/J versus C57BL/6 mouse strains. Moreover, evidence suggested that BALB/c and A/J share an allele(s) at this locus that is different from C57BL/6 mice. Here we tested the hypothesis that differences in collateral extent and/or remodeling underlie these findings. Compared with C57BL/6, BALB/c and A/J strains have fewer native collaterals in hindlimb (also confirmed in brain)—associated with greater reduction in perfusion immediately after femoral ligation, slower recovery of perfusion, greater hindlimb use impairment, and worse ischemia. However, A/J also differed from BALB/c in a number of these parameters, including having more robust collateral remodeling. Analysis of A/J -> C57BL/6 chromosome substitution strains confirmed that a difference in an allele(s) on chromosome 7 conferred most, but not all, of the magnitude of the differences in collateral function. Additional studies of C57BL/6 x BALB/c F1 mice demonstrated that alleles of the C57BL/6 strain exert dominance for collateral traits. Finally, negative results were obtained from studies examining a previously identified candidate gene potentially responsible for these differences—Bcl2-associated athanogene-3. These findings emphasize the major contribution of genetic background to variation in the collateral circulation and its capacity to lessen ischemia in obstructive disease.

 
 
 
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