N-Acyl homoserine lactone (AHL) quorum sensing (QS) controls expression of over 200 genes in Pseudomonas aeruginosa. There are two AHL regulatory systems: the LasR-LasI circuit and the RhlR-RhlI system. We mapped transcription termination sites affected by AHL QS in P. aeruginosa, and in doing so we identified AHL-regulated small RNAs (sRNAs). Of interest, we noted that one particular sRNA was located within the rhlI locus. We found that rhlI, which encodes the enzyme that produces the AHL N-butanoyl-homoserine lactone (C4-HSL), is controlled by a 5′ untranslated region (UTR)-derived sRNA we name RhlS. We also identified an antisense RNA encoded opposite the beginning of the rhlI open reading frame, which we name asRhlS. RhlS accumulates as wild-type cells enter stationary phase and is required for the production of normal levels of C4-HSL through activation of rhlI translation. RhlS also directly posttranscriptionally regulates at least one other unlinked gene, fpvA. The asRhlS appears to be expressed at maximal levels during logarithmic growth, and we suggest RhlS may act antagonistically to the asRhlS to regulate rhlI translation. The rhlI-encoded sRNAs represent a novel aspect of RNA-mediated tuning of P. aeruginosa QS. IMPORTANCE The opportunistic human pathogen Pseudomonas aeruginosa possesses multiple quorum sensing systems that regulate and coordinate production of virulence factors and adaptation to different environments. Despite extensive research, the regulatory elements that play a role in this complex network are still not fully understood. By using several RNA sequencing techniques, we were able to identify a small regulatory RNA we named RhlS. RhlS increases translation of RhlI, a key enzyme in the quorum sensing pathway, and represses the fpvA mRNA encoding one of the siderophore pyoverdine receptors. Our results highlight a new regulatory layer of P. aeruginosa quorum sensing and contribute to the growing understanding of the role regulatory RNAs play in bacterial physiology.

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The purpose of this study was to investigate the association between gender and primary open-angle glaucoma (POAG) among African Americans and to assess demographic, systemic, and behavioral factors that may contribute to differences between genders. The Primary Open-Angle African American Glaucoma Genetics (POAAGG) study had a case-control design and included African Americans 35 years and older, recruited from the greater Philadelphia, Pennsylvania. Diagnosis of POAG was based on evidence of both glaucomatous optic nerve damage and characteristic visual field loss. Demographic and behavioral information, history of systemic diseases and anthropometric measurements were obtained at study enrollment. Gender differences in risk of POAG were examined using multivariate logistic regression. A total of 2,290 POAG cases and 2,538 controls were included in the study. The percentage of men among cases was higher than among controls (38.6% vs 30.3%, P<0.001). The subjects’ mean age at enrollment was significantly higher for cases compared to controls (70.2±11.3 vs. 61.6±11.8 years, P<0.003). Cases had lower rates of diabetes (40% vs. 46%, P<0.001), higher rates of systemic hypertension (80% vs. 72%, P<0.001), and lower body mass index (BMI) (29.7±6.7 vs. 31.9±7.4, P<0.001) than controls. In the final multivariable model, male gender was significantly associated with POAG risk (OR, 1.64; 95% CI, 1.44–1.87; P<0.001), after adjusting for age, systemic hypertension, diabetes, and BMI. Within the POAAGG study, men were at higher risk of having POAG than women. Pending genetic results from this study will be used to better understand the underlying genetic variations that may account for these differences.

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Background: It is currently unclear whether primary open-angle glaucoma (POAG) affects neurological functions outside of vision, such as cognition. Objective: This study examined the association between POAG and cognitive impairment in African Americans. Methods: Masked interviewers administered the Montreal Cognitive Assessment (MoCA) to patients enrolled in the Primary Open-Angle African American Glaucoma Genetics (POAAGG) study at the Scheie Eye Institute. Cases were further assessed for retinal nerve fiber layer (RNFL) thickness and visual field (VF) loss. Univariate and multivariate linear regression analyses were performed to compare mean MoCA score between cases and controls and to assess the association between POAG severity and MoCA score. Results: A total of 137 patients completed the MoCA, including 70 cases and 67 controls. The mean age ± SD was 68.7 ± 11.2 years for cases and 65.7 ± 10.4 years for controls (p = 0.11). The mean MoCA total score (out of 30 points) was 20.3 among POAG cases and 21.3 among controls (mean difference = –1.03, 95% confidence interval, CI = –2.54 to 0.48, p = 0.18). After adjusting for age, gender, education level, diabetes, hypertension, and smoking status, the mean difference in the MoCA total score between cases and controls was –0.64 (95% CI = –1.72 to 0.45, p = 0.25). Among cases, more VF loss was associated with lower total MoCA score for mean deviation (adjusted linear trend p = 0.02) and VF index (adjusted linear trend p = 0.03). There was no significant association between average RNFL thickness and total MoCA score. Conclusions: POAG cases and controls had similar neurocognitive function as measured by the MoCA. Among POAG cases, worse VF loss was associated with lower MoCA. Future studies are needed to further elucidate the clinical effect of neuropathy in POAG.

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