Increased activity of the alpha 1(I) procollagen promoter in skin fibroblasts from patients with chronic eosinophilia-myalgia syndrome.

Eosinophilia-myalgia syndrome (EMS), a novel L-tryptophan-associated disease, which occurred as an epidemic in 1989, is characterized by diffuse fibrosis of the skin. The objective of these studies was to compare the in vitro expression of the gene encoding the human alpha 1(I) procollagen (COL1A1) in dermal fibroblasts derived from patients with long-standing EMS and from healthy controls. Early passage fibroblasts in culture were transiently transfected with a series of progressively 5' deleted human COL1A1 promoter-CAT reporter gene DNA constructs. Resultant CAT activity was assayed in the cytoplasmic extracts. Following transient transfection, COL1A1 promoter activity in 4/5 fibroblast cell lines derived from patients with EMS was two-to threefold greater than in matched normal fibroblasts. Deletion analysis indicated that CAT activity was highest, and displayed the greatest increase in EMS vs normal fibroblasts, with promoter constructs spanning 174 bp upstream from the COL1A1 transcription start site. The study shows increased CAT activity driven by a 174 bp fragment of COL1A1 in transiently transfected skin fibroblasts from patients with EMS even in the chronic stage of disease. These findings expand on previous observations indicating increased type I collagen gene expression in EMS fibroblasts, and suggest that fibrosis in L-tryptophan-induced EMS is associated with transcriptional activation of type I collagen gene expression, which persists even following cessation of L-tryptophan use.

Pharmacogenetic characteristics of the eosinophilia-myalgia syndrome.

This study tested the hypothesis that patterns of xenobiotic metabolism in patients with eosinophilia-myalgia syndrome (EMS) differed from healthy control subjects. We determined the genotypes of 27 EMS patients with EMS and 114 control subjects for the cytochrome P450 CYP2D6 polymorphism. The metabolic phenotypes of patients with EMS for S-mephenytoin hydroxylation (n = 17) and dapsone acetylation (n = 19) were determined and compared with 29 healthy control subjects. The incidence of the CYP2D6 poor metabolizer genotype (mutant/mutant) was 0.185 in patients with EMS and 0.061 in control subjects (Mantel-Haenszel, chi 2 = 7.213, p = 0.007). The mephenytoin S/R ratios were 0.39 +/- 0.23 in patients with EMS versus 0.18 +/- 0.13 in control subjects (p < or = 0.005). There was no difference in dapsone acetylation between the two groups. A pattern of xenobiotic metabolism may play a role in the pathogenesis of EMS, but the precise role that it plays remains unclear.

1,1'-Ethylidenebis[L-tryptophan], a contaminant implicated in L-tryptophan eosinophilia myalgia syndrome, suppresses mRNA expression of hypothalamic corticotropin-releasing hormone in Lewis (LEW/N) rat brain.

The L-tryptophan eosinophilia myalgia syndrome (L-Trp-EMS), related to ingestion of impure L-Trp, occurred in epidemic proportions in the United States in 1989. Epidemiologic studies implicated 1,1'-ethylidenebis[L-tryptophan] (EBT) as the impurity most highly associated with development of human L-Trp-EMS. We have previously shown that Lewis (LEW/N) rats fed L-Trp implicated in the L-Trp-EMS epidemic (case-associated L-Trp) develop fasciitis and perimyositis which is associated with a reduction in corticotropin-releasing hormone (CRH) mRNA expression in the hypothalamic paraventricular nucleus (PVN). In this study, we report the effects of EBT- and case-associated L-Trp on CRH mRNA expression in the hypothalamic PVN and secretion of adrenocorticotropic hormone (ACTH) and corticosterone (CORT) into the plasma over a time course of 1-6 weeks in the same rats in which we have found fascial thickening and immune cell activation induced by these compounds. Both control L-Trp and EBT stimulated the secretion of ACTH and CORT at 1-2 weeks, whereas case-associated L-Trp did not. EBT and case-associated L-Trp decreased CRH mRNA expression in the PVN at 2-6 weeks, while control L-Trp had no effect. The striking contrast in the effects of case-associated L-Trp and EBT on the HPA axis suggests that the reduction in CRH mRNA levels in the PVN seen in each case may be related to different mechanisms. It is possible that EBT suppresses CRH mRNA expression directly, in the absence of inflammation, while case-associated L-Trp may act through multiple mechanisms, including that associated with inflammation.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased type I collagen gene expression in L-tryptophan associated eosinophilia-myalgia syndrome skin fibroblasts.

OBJECTIVE: To investigate the pathogenetic mechanisms responsible for the cutaneous fibrosis in eosinophilia-myalgia syndrome (EMS) associated with L-tryptophan ingestion. METHODS: Compare in vitro type I collagen production and steady state procollagen mRNA levels in cultured skin fibroblasts derived from healthy individuals and from 5 patients with EMS and diffuse cutaneous induration. RESULTS: Cell lines derived from the affected skin from patients with EMS exhibited greater collagen production and higher steady state levels of alpha 1(I) procollagen mRNA compared with fibroblasts from age and sex matched healthy individuals. Exposure to interferon gamma reduced collagen synthesis in the EMS fibroblast lines. The rate of in vitro transcription of the COL1A1 gene was 30% higher in nuclei isolated from collagen overproducer EMS fibroblasts than in nuclei from normal fibroblasts. CONCLUSION: Fibroblasts derived from the involved skin of patients with EMS show increased expression of the alpha 1(I) procollagen gene in vitro compared to normal skin fibroblasts. The biosynthetically activated phenotype exhibited by EMS fibroblasts appears to be due, at least in part, to transcriptional activation of type I collagen gene expression. These biochemical and molecular alterations may result in accumulation of collagen and lead to the cutaneous fibrosis in EMS.