Human FHL2 ELISA Matched Antibody Pair

OBJECTIVES We tested the hypothesis that the developmental changes occurring in I-Kr and I-Ks can be explained by changes in the expression of ERG encoding I-Kr, and KCNQ1, the beta subunit minK, and the recently reported subunit FHL2 encoding I-Ks. BACKGROUND The delayed rectifier current contributes importantly to the developmental evolution of the canine myocardial action potential. Specifically, in left ventricular epicardial myocytes, I-Ks is absent and I-Kr is the major repolarizing current until age 4 weeks. With subsequent development, I-Ks density increases and I-Kr decreases, resulting in an altered voltage-time course of repolarization. METHODS We used Western blotting and real-time polymerase chain reaction to compare the expression of ERG, KCNQ1, minK, and FHL2 in 1-week-old pups and adult dogs. RESULTS ERG levels are high at I week and decrease significantly with age, consistent with developmental decrease in I-Kr Whereas expression of KCNQ1 and FHL2 is unchanged between the two age groups, minK is minimally expressed at I week and increases in adults, consistent with developmental increase in I-Ks. CONCLUSIONS A reduction in ERG explains the developmental decrease in I-Kr, whereas the accessory subunit minK appears to be the critical determinant of developmental evolution of I-Ks. (C) 2004 Heart Rhythm Society. All rights reserved.

Objective. Fewer than 5% of monozygotic (MZ) and dizygotic (DZ) twin pairs are clinically concordant for systemic sclerosis (SSc), yet the majority of MZ twins are concordant for antinuclear antibodies. To discover genetic versus nongenetic molecular pathways important to the pathogenesis of SSc, we compared global gene expression patterns in twins discordant for Ssc. Methods. Total RNA from dermal fibroblasts of 15 discordant twin pairs (10 MZ and 5 DZ) and 5 normal controls were used in microarray analysis. Ab-errantly expressed genes were confirmed using quantitative real-time reverse transcriptase-polymerase chain reaction. Results. Lesional and nonlesional fibroblasts from SSc patients showed no significant differences in gene expression, while SSc patients had gene profiles that were significantly different from those of unaffected DZ twins and normal controls. Unaffected MZ twins, however, were not significantly different from SSc patients. Unsupervised hierarchical clustering segregated the fibroblast samples as originating from 2 major groups. Group A contained 5 discordant MZ twin pairs, 3 affected MZ twins, and 3 affected DZ twins. Group B contained all 5 normal population controls, all 5 healthy DZ twins, 2 discordant MZ twins, and 2 discordant DZ twin pairs. Normal fibroblasts incubated with serum from an SSc-affected patient or with serum from her unaffected MZ twin sister developed the increased expression of COL1A2, SPARC, and CTGF typically seen in SSc fibroblasts. Conclusion. These results demonstrate that dermal fibroblasts from SSc patients and from 40-50% of their genetically identical but clinically unaffected MZ twins exhibit a similar gene expression pattern which can be induced in normal fibroblasts by sera from both. Thus, a stronger genetic predisposition to SSc (than can be detected clinically) is apparent at the molecular level in skin fibroblasts.