Publications

BACKGROUND

Cardiovascular disease (CVD) is an increasing cause of morbidity and mortality in HIV-infected patients. However, it is controversial whether HIV infection contributes to accelerated atherosclerosis independent of traditional CVD risk factors.

METHODS

Cross-sectional study of HIV-infected participants and controls without pre-existing CVD from the study of Fat Redistribution and Metabolic Change in HIV Infection (FRAM) and the Multi-Ethnic Study of Atherosclerosis (MESA). Preclinical atherosclerosis was assessed by carotid intima-medial thickness (cIMT) measurements in the internal/bulb and common regions in HIV-infected participants and controls after adjusting for traditional CVD risk factors.

RESULTS

For internal carotid, mean IMT was 1.17 +/- 0.50 mm for HIV-infected participants and 1.06 +/- 0.58 mm for controls (P < 0.0001). After multivariable adjustment for demographic characteristics, the mean difference of HIV-infected participants vs. controls was 0.188 mm [95% confidence interval (CI) 0.113-0.263, P < 0.0001]. Further adjustment for traditional CVD risk factors modestly attenuated the HIV association (0.148 mm, 95% CI 0.072-0.224, P = 0.0001). For the common carotid, HIV infection was independently associated with greater IMT (0.033 mm, 95% CI 0.010-0.056, P = 0.005). The association of HIV infection with IMT was similar to that of smoking, which was also associated with greater IMT (internal 0.173 mm, common 0.020 mm).

CONCLUSION

Even after adjustment for traditional CVD risk factors, HIV infection was accompanied by more extensive atherosclerosis measured by IMT. The stronger association of HIV infection with IMT in the internal/bulb region compared with the common carotid may explain previous discrepancies in the literature. The association of HIV infection with IMT was similar to that of traditional CVD risk factors, such as smoking.

Neutralization of the normally acidic stratum corneum (SC) has deleterious consequences for permeability barrier homeostasis and SC integrity/cohesion attributable to serine proteases (SPs) activation leading to deactivation/degradation of lipid-processing enzymes and corneodesmosomes (CD). As an elevated pH compromises SC structure and function, we asked here whether SC hyperacidification would improve the structure and function. We lowered the pH of mouse SC using two polyhydroxyl acids (PHA), lactobionic acid (LBA), or gluconolactone (GL). Applications of the PHA reduced the pH at all levels of SC of hairless mouse, with further selective acidification of SC membrane domains, as shown by fluorescence lifetime imaging. Hyperacidification improved permeability barrier homeostasis, attributable to increased activities of two key membrane-localized, ceramide-generating hydrolytic enzymes (beta-glucocerebrosidase and acidic sphingomyelinase), which correlated with accelerated extracellular maturation of SC lamellar membranes. Hyperacidification generated "supernormal" SC integrity/cohesion, attributable to an SP-dependent decreased degradation of desmoglein-1 (DSG1) and the induction of DSG3 expression in lower SC. As SC hyperacidification improves the structure and function, even of normal epidermis, these studies lay the groundwork for an assessment of the potential utility of SC acidification as a therapeutic strategy for inflammatory dermatoses, characterized by abnormalities in barrier function, cohesion, and surface pH.

Membrane transporters play crucial roles in the cellular uptake and efflux of an array of small molecules including nutrients, environmental toxins, and many clinically used drugs. We hypothesized that common genetic variation in the proximal promoter regions of transporter genes contribute to observed variation in drug response. A total of 579 polymorphisms were identified in the proximal promoters (-250 to +50 bp) and flanking 5' sequence of 107 transporters in the ATP Binding Cassette (ABC) and Solute Carrier (SLC) superfamilies in 272 DNA samples from ethnically diverse populations. Many transporter promoters contained multiple common polymorphisms. Using a sliding window analysis, we observed that, on average, nucleotide diversity (pi) was lowest at approximately 300 bp upstream of the transcription start site, suggesting that this region may harbor important functional elements. The proximal promoters of transporters that were highly expressed in the liver had greater nucleotide diversity than those that were highly expressed in the kidney consistent with greater negative selective pressure on the promoters of kidney transporters. Twenty-one promoters were evaluated for activity using reporter assays. Greater nucleotide diversity was observed in promoters with strong activity compared to promoters with weak activity, suggesting that weak promoters are under more negative selective pressure than promoters with high activity. Collectively, these results suggest that the proximal promoter region of membrane transporters is rich in variation and that variants in these regions may play a role in interindividual variation in drug disposition and response.

Pseudomonas aeruginosa is responsible for potentially life-threatening infections in individuals with compromised defense mechanisms and those with cystic fibrosis. P. aeruginosa infection is notable for the appearance of a humoral response to some known antigens, such as flagellin C, elastase, alkaline protease, and others. Although a number of immunogenic proteins are known, no effective vaccine has been approved yet. Here, we report a comprehensive study of all 262 outer membrane and exported P. aeruginosa PAO1 proteins by a modified protein microarray methodology called the nucleic acid-programmable protein array. From this study, it was possible to identify 12 proteins that trigger an adaptive immune response in cystic fibrosis and acutely infected patients, providing valuable information about which bacterial proteins are actually recognized by the immune system in vivo during the natural course of infection. The differential detections of these proteins in patients and controls proved to be statistically significant (P<0.01). The study provides a list of potential candidates for the improvement of serological diagnostics and the development of vaccines.