Sensorineural hearing loss in children with sickle cell disease.

INTRODUCTION: Sensorineural hearing loss (SNHL) has been reported to occur at increased frequency in the pediatric sickle cell disease (SCD) population, likely secondary to ototoxic medication regimens and repeat sickling events that lead to end organ damage. Risk and protective factors of SNHL in this population are not fully characterized. The objective of this study was to describe audiology results in children with SCD and the prevalence and sequelae of SNHL. METHODS: A comprehensive clinical database of 2600 pediatric SCD patients treated at 1 institution from 2010-16 was retrospectively reviewed to identify all patients who were referred for audiologic testing. Audiologic test results, patient characteristics, and SCD treatments were reviewed. RESULTS: 181 SCD children (97 male, 153 HbSS) underwent audiologic testing, with 276 total audiology encounters, ranging 1-9 per patient. Mean age at first audiogram was 8.9 ±â€¯5.2 years. 29.8% had prior cerebrovascular infarct and an additional 25.4% had prior abnormal transcranial Doppler screens documented at time of first audiogram. Overall, 13.3% had documented hearing loss, with 6.6% SNHL. Mean pure tone average (PTA) among patients with SNHL ranged from mild to profound hearing loss (Right: 43.3 ±â€¯28.9, Left: 40.8 ±â€¯29.7), sloping to more severe hearing loss at higher frequencies. CONCLUSIONS: Hearing loss was identified in a significant subset of children with SCD and the hearing loss ranged from normal to profound. Though the overall prevalence of SNHL in SCD patients was low, baseline audiology screening should be considered.

Adenotonsillectomy in children with sickle cell disease and obstructive sleep apnea.

INTRODUCTION: Obstructive sleep apnea (OSA) is prevalent and may be more severe in children with Sickle Cell Disease (SCD) compared to the general pediatric population. OBJECTIVES: The objective of this study was to describe the therapeutic effects and complications of tonsillectomy and adenoidectomy (T&A) for treatment of OSA in children with SCD. METHODS: A comprehensive database of pediatric SCD patients was reviewed to identify all patients who underwent T&A between 2010 and 2016. An IRB-approved, retrospective review of laboratory values, perioperative course, pre- and post-T&A hospital utilization, and polysomnography was conducted. RESULTS: There were 132 SCD children (108 HbSS) who underwent T&A. Mean age was 7.6 ±â€¯4.6 years. The mean baseline hemoglobin of these patients was 9.3 ±â€¯1.4 g/dL; 72.7% of patients had pre-operative transfusion, such that the mean Hb at time of T&A was 11.4 ±â€¯1.0 g/dL. The average admission length surrounding T&A was 3.5 ±â€¯1.2 days. Complications were documented in 11.4% of operative cases. Polysomnography was available in 104 pre-T&A and 45 post-T&A. The Apnea-Hypopnea Index decreased on post-T&A polysomnogram (7.6 ±â€¯8.7 vs. 1.3 ±â€¯1.9, p = 0.0001). The O2 nadir improved on post-T&A polysomnogram (81.2 ±â€¯10.8 vs. 89.3 ±â€¯7, p = 0.0003). Emergency room visits (mean events per year) decreased post-operatively (2.6 ±â€¯2.8 vs. 1.8 ±â€¯2.2, p = 0.0002). CONCLUSIONS: T&A can be a safe and effective option to treat OSA in pediatric patients with SCD and was significantly associated with reduced AHI and fewer ER visits post-operatively.

Prorenin receptor (PRR)-mediated NADPH oxidase (Nox) signaling regulates VEGF synthesis under hyperglycemic condition in ARPE-19 cells.

The stimulation of angiotensin II (Ang II), the effector peptide of renin-angiotensin system, has been reported to increase the expression of vascular endothelial growth factor (VEGF) through the activation of the Ang II type 1 receptor (AT1R). In this study, we investigated whether hyperglycemia (HG, 33 mM glucose) in ARPE-19 cells could promote the expression of VEGF independently of Ang II through prorenin receptor (PRR), via an NADPH oxidase (Nox)-dependent mechanism. ARPE-19 cells were treated with the angiotensin converting enzyme (ACE) inhibitor perindopril to block the synthesis of Ang II. Treatment with HG induced VEGF expression in ARPE-19 cells, which was attenuated by pretreatment with the inhibitors of Nox, but not those of nitric oxide synthase, xanthine oxidase and mitochondrial O2 synthesis. In addition, Nox-derived [Formula: see text] and H2O2 signaling in the regulation of VEGF was determined by using both polyethylene glycol (PEG)-catalase (CAT) and PEG-superoxide dismutase (SOD). We demonstrated that small interfering RNA (siRNA)-mediated knockdown of PRR, Nox2 and Nox4 significantly reduced the HG-induced stimulation of VEGF. On the other hand, Nox4 overexpression significantly potentiated PRR-induced stimulation of VEGF under hyperglycemia in ARPE-19 cells. Furthermore, Nox4 was shown to be associated with enhanced activities of ERK1/2 and NF-κB (p65), indicating their involvement in PRR-induced activation of VEGF under HG in ARPE-19 cells. Our results support the hypothesis that Nox4-derived reactive oxygen species (ROS) signaling is implicated in the hyperglycemia-induced increase of VEGF expression through PRR in ARPE-19 cells. However, further work is needed to evaluate the role of PRR and Nox-s in HG-induced stimulation of VEGF in vivo.

MicroRNA-152 represses VEGF and TGFß1 expressions through post-transcriptional inhibition of (Pro)renin receptor in human retinal endothelial cells.

PURPOSE: The (pro)renin receptor (PRR), a component of the renin-angiotensin system (RAS), plays an important role in the physiologic and pathophysiological regulation of blood pressure and fluid/electrolyte homeostasis. The RAS including the PRR has been identified in retinal endothelial cells and other ocular tissues. In this study, the potential involvement of miRNAs in the posttranscriptional regulation of PRR was investigated in human retinal endothelial cells (hRECs) under high glucose (HG) conditions. METHODS: miRNA-152 (miR-152) was identified in silico as a potential regulator of PRR, and this was confirmed by quantitative real-time PCR (qRT-PCR) and PRR 3'-untranslated region (UTR) reporter assays. Using RNA interference, both AT1R and PRR were implicated in the HG-mediated induction of vascular endothelial growth factor (VEGF), VEGF receptor 2 (VEGFR-2), and transforming growth factor ß1 (TGFß1). RESULTS: The downregulation of miR-152 was observed in hRECs and rat retinal tissues under HG conditions. In parallel, PRR (target of miR-152), VEGF, VEGFR-2, and TGFß1 at mRNA levels were elevated. However, the transfection of hRECs with miR-152 mimics in HG conditions resulted in the suppression of the PRR expression, as well as reduced VEGF, VEGFR-2, and TGFß1 production. This was reversed by transfecting cells with the antisense (antagomir) of miR-152, suggesting the glucose-induced upregulation of VEGF, VEGFR-2, and TGFß1 is mediated through PRR, and this regulation is likely achieved through the HG-mediated modulation of miRNAs. CONCLUSIONS: We have demonstrated that miR-152 interacting with PRR regulates downstream VEGF, VRGFR-2, and TGFß1 expressions in hRECs in HG conditions. These studies suggest miR-152 and PRR may play a role in the pathogenesis of diabetic retinopathy (DR).

Mutations of the ompK36 porin gene and promoter impact responses of sequence type 258, KPC-2-producing Klebsiella pneumoniae strains to doripenem and doripenem-colistin.

Doripenem-colistin exerts synergy against some, but not all, Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae strains in vitro. We determined if doripenem MICs and/or ompK36 porin gene mutations impacted the responses of 23 sequence type 258 (ST258), KPC-2-producing strains to the combination of doripenem (8 µg/ml) and colistin (2 µg/ml) during time-kill assays. The median doripenem and colistin MICs were 32 and 4 µg/ml. Doripenem MICs did not correlate with KPC-2 expression levels. Five and 18 strains had wild-type and mutant ompK36, respectively. The most common mutations were IS5 promoter insertions (n = 7) and insertions encoding glycine and aspartic acid at amino acid (aa) positions 134 and 135 (ins aa134-135 GD; n = 8), which were associated with higher doripenem MICs than other mutations or wild-type ompK36 (all P values ≤ 0.04). Bactericidal activity (24 h) was achieved by doripenem-colistin against 12%, 43%, and 75% of ins aa134-135 GD, IS5, and wild-type/other mutants, respectively (P = 0.04). Doripenem-colistin was more active in time-kill studies than colistin at 12 and 24 h if the doripenem MIC was ≤8 µg/ml (P = 0.0007 and 0.09, respectively), but not if the MIC was >8 µg/ml (P = 0.10 and 0.16). Likewise, doripenem-colistin was more active at 12 and 24 h against the wild type/other mutants than ins aa134-135 GD or IS5 mutants (P = 0.007 and 0.0007). By multivariate analysis, the absence of ins aa134-135 GD or IS5 mutations was the only independent predictor of doripenem-colistin responses at 24 h (P = 0.002). In conclusion, ompK36 genotypes identified ST258 KPC-K. pneumoniae strains that were most likely to respond to doripenem-colistin.

Global microRNA expression profiling: curcumin (diferuloylmethane) alters oxidative stress-responsive microRNAs in human ARPE-19 cells.

PURPOSE: In recent years, microRNAs (miRNAs) have been reported to play important roles in a broad range of biologic processes, including oxidative stress-mediated ocular diseases. In addition, the polyphenolic compound curcumin has been shown to possess anti-inflammatory, antioxidant, anticancer, antiproliferative, and proapoptotic activities. The aim of this study was to investigate the impact of curcumin on the expression profiles of miRNAs in ARPE-19 cells exposed to oxidative stress. METHODS: MiRNA expression profiles were measured in ARPE-19 cells treated with 20 µΜ curcumin and 200 µΜ H2O2. PCR array analysis was performed using web-based software from SABiosciences. The cytotoxicity of ARPE-19 cells was determined with the CellTiter-Blue cell viability assay. The effects of curcumin on potential miRNA targets were analyzed with quantitative real-time PCR and western blotting. RESULTS: Curcumin treatment alone for 6 h had no effect on ARPE-19 cell viability. Incubation with H2O2 (200 µM) alone for 18 h decreased cell viability by 12.5%. Curcumin alone downregulated 20 miRNAs and upregulated nine miRNAs compared with controls. H2O2 downregulated 18 miRNAs and upregulated 29 miRNAs. Furthermore, curcumin pretreatment in cells exposed to H2O2 significantly reduced the H2O2-induced expression of 17 miRNAs. As determined with quantitative real-time PCR and western blotting, curcumin increased the expression of antioxidant genes and reduced angiotensin II type 1 receptor, nuclear factor-kappa B, and vascular endothelial growth factor expression at the messenger RNA and protein levels. CONCLUSIONS: The results demonstrated that curcumin alters the expression of H2O2-modulated miRNAs that are putative regulators of antioxidant defense and renin-angiotensin systems, which have been reported to be linked to ocular diseases.