47XXY and 47XXX in Scleroderma and Myositis

Objective

We undertook this study to examine the X chromosome complement in participants with systemic sclerosis (SSc) as well as idiopathic inflammatory myopathies.

Methods

The participants met classification criteria for the diseases. All participants underwent single‐nucleotide polymorphism typing. We examined X and Y single‐nucleotide polymorphism heterogeneity to determine the number of X chromosomes. For statistical comparisons, we used χ² analyses with calculation of 95% confidence intervals.

Results

Three of seventy men with SSc had 47,XXY (P = 0.0001 compared with control men). Among the 435 women with SSc, none had 47,XXX. Among 709 men with polymyositis or dermatomyositis (PM/DM), seven had 47,XXY (P = 0.0016), whereas among the 1783 women with PM/DM, two had 47,XXX. Of 147 men with inclusion body myositis (IBM), six had 47,XXY, and 1 of the 114 women with IBM had 47,XXX. For each of these myositis disease groups, the excess 47,XXY and/or 47,XXX was significantly higher compared with in controls as well as the known birth rate of Klinefelter syndrome or 47,XXX.

Conclusion

Klinefelter syndrome (47,XXY) is associated with SSc and idiopathic inflammatory myopathies, similar to other autoimmune diseases with type 1 interferon pathogenesis, namely, systemic lupus erythematosus and Sjögren syndrome.

21-aminosteroid and 2-(aminomethyl)chromans inhibition of arachidonic acid-induced lipid peroxidation and permeability enhancement in bovine brain microvessel endothelial cell monolayers

Selected 21-aminosteroids (U74500A, U74006F, and U74389G) and a 2-(aminomethyl)chromans (U78517F) were tested for their efficacy in preventing arachidonate-induced lipid peroxidation and permeability alterations in brain microvessel endothelial cells (BMECs). The 21-aminosteroids and 2-(aminomethyl)chromans were effective in varying degrees in inhibiting (U74500A = U78517F > U74006F = U74389G) concentration- and time-dependent arachidonate-induced thiobarbituric acid reactive substances (TBARS) production by BMECs. Arachidonate produced a corresponding concentration-dependent increase in BMEC monolayer permeability to the membrane impermeant marker, sucrose. Pretreatment of BMEC monolayers with either the 21-aminosteroids or the 2-(aminomethyl)chromans completely blocked the arachidonate-induced increase in permeability to sucrose. Our results demonstrated that these membrane-associating antioxidants were particularly effective in preventing both arachidonic acid-induced lipid peroxidation and permeability changes in BMEC monolayers. However, concentrations of some antioxidants that only partially inhibited TBARS production, completely inhibited the arachidonic acid-induced enhancement in BMEC monolayer permeability. Therefore, arachidonic acid-induced effects on BMEC permeability were likely due in part to both lipid peroxidation and direct or indirect effects of the fatty acid on membrane integrity. This study provides further support for the application of primary cultures of BMECs as a useful in vitro system to evaluate mechanisms through which mediators of disease or injury states compromise blood-brain barrier integrity.

Leucine enkephalin effects on paracellular and transcellular permeation pathways across brain microvessel endothelial cell monolayers

Leucine enkephalin (YGGFL) effects on markers for transcellular and paracellular permeation across the blood-brain barrier (BBB) were investigated in vitro with bovine brain microvessel endothelial cell (BMEC) monolayers in primary culture. Intact YGGFL, but not metabolites of YGGFL, stimulated BMEC uptake of lucifer yellow (LY), a marker for fluid-phase endocytosis, in a concentration-dependent manner. However, D-[Ala2]-leucine enkephalin (YAGFL), a YGGFL analogue that altered BMEC monolayer permeability, had no effect on LY uptake. In part, these results suggested that YGGFL's effects on fluid-phase uptake might not relate directly to enhanced BMEC transcellular permeability in the presence of the peptide. The measurement of the fluorescence anisotropy of membrane-bound diphenyl-hexatriene probes did not show substantial peptide-induced changes in membrane lipid packing order (i.e., membrane fluidity) and indicated a limited role for membrane perturbations in YGGFL-induced changes in BMEC monolayer permeability. Conversely, the apparent permeability coefficients showed size-dependent YGGL-induced alterations for passage of membrane-impermeant substances across BMEC monolayers. The apparent permeability coefficients of low-molecular-weight (low-mol-wt) molecules (mannitol, sucrose, and fluorescein) were increased on exposure to YGGFL. The apparent permeability coefficients for high-mol-wt molecules, FITC dextran conjugates (4, 20, and 71.6 Kd), were not affected by exposure to YGGFL. Transmission electron micrographs of lanthanum (Stoke's radius, 10 A) exclusion from BMEC intercellular junctions supported these observations. Collectively, results from this study suggest that YGGFL enhanced BMEC permeability either by altering paracellular openings or through formation of a small pore in the monolayers to allow preferential penetration of low-mol-wt or small molecular size (< 10 A) substances.