Whole genome sequencing for USH2A-associated disease reveals several pathogenic deep-intronic variants that are amenable to splice correction

A significant number of individuals with a rare disorder such as Usher syndrome (USH) and (non-)syndromic autosomal recessive retinitis pigmentosa (arRP) remain genetically unexplained. Therefore, we assessed subjects suspected of USH2A-associated disease and no or mono-allelic USH2A variants using whole genome sequencing (WGS) followed by an improved pipeline for variant interpretation to provide a conclusive diagnosis. One hundred subjects were screened using WGS to identify causative variants in USH2A or other USH/arRP-associated genes. In addition to the existing variant interpretation pipeline, a particular focus was put on assessing splice-affecting properties of variants, both in silico and in vitro. Also structural variants were extensively addressed. For variants resulting in pseudoexon inclusion, we designed and evaluated antisense oligonucleotides (AONs) using minigene splice assays and patient-derived photoreceptor precursor cells. Biallelic variants were identified in 49 of 100 subjects, including novel splice-affecting variants and structural variants, in USH2A or arRP/USH-associated genes. Thirteen variants were shown to affect USH2A pre-mRNA splicing, including four deep-intronic USH2A variants resulting in pseudoexon inclusion, which could be corrected upon AON treatment. We have shown that WGS, combined with a thorough variant interpretation pipeline focused on assessing pre-mRNA splicing defects and structural variants, is a powerful method to provide subjects with a rare genetic condition, a (likely) conclusive genetic diagnosis. This is essential for the development of future personalized treatments and for patients to be eligible for such treatments

Whole genome sequencing for USH2A-associated disease reveals several pathogenic deep-intronic variants that are amenable to splice correction

A significant number of individuals with a rare disorder such as Usher syndrome (USH) and (non-)syndromic autosomal recessive retinitis pigmentosa (arRP) remain genetically unexplained. Therefore, we assessed subjects suspected of USH2A-associated disease and no or mono-allelic USH2A variants using whole genome sequencing (WGS) followed by an improved pipeline for variant interpretation to provide a conclusive diagnosis. One hundred subjects were screened using WGS to identify causative variants in USH2A or other USH/arRP-associated genes. In addition to the existing variant interpretation pipeline, a particular focus was put on assessing splice-affecting properties of variants, both in silico and in vitro. Also structural variants were extensively addressed. For variants resulting in pseudoexon inclusion, we designed and evaluated antisense oligonucleotides (AONs) using minigene splice assays and patient-derived photoreceptor precursor cells. Biallelic variants were identified in 49 of 100 subjects, including novel splice-affecting variants and structural variants, in USH2A or arRP/USH-associated genes. Thirteen variants were shown to affect USH2A pre-mRNA splicing, including four deep-intronic USH2A variants resulting in pseudoexon inclusion, which could be corrected upon AON treatment. We have shown that WGS, combined with a thorough variant interpretation pipeline focused on assessing pre-mRNA splicing defects and structural variants, is a powerful method to provide subjects with a rare genetic condition, a (likely) conclusive genetic diagnosis. This is essential for the development of future personalized treatments and for patients to be eligible for such treatments.</p

Self-reported antibiotic stewardship and infection control measures from 57 intensive care units: An international ID-IRI survey

We explored the self-reported antibiotic stewardship (AS), and infection prevention and control (IPC) activities in intensive care units (ICUs) of different income settings. A cross-sectional study was conducted using an online questionnaire to collect data about IPC and AS measures in participating ICUs. The study participants were Infectious Diseases-International Research Initiative (IDI-IR) members, committed as per their institutional agreement form. We analyzed responses from 57 ICUs in 24 countries (Lower-middle income (LMI), n = 13; Upper-middle income (UMI), n = 33; High-income (HI), n = 11). This represented (similar to 5%) of centers represented in the ID-IRI. Surveillance programs were implemented in (76.9%-90.9%) of ICUs with fewer contact precaution measures in LMI ones (p = 0.02); (LMI:69.2%, UMI:97%, HI:100%). Participation in regional antimicrobial resistance programs was more significantly applied in HI (p = 0.02) (LMI:38.4%,UMI:81.8%,HI:72.2%). AS programs are implemented in 77.2% of institutions with AS champions in 66.7%. Infectious diseases physicians and microbiologists are members of many AS teams (59%&amp;50%) respectively. Unqualified healthcare professionals(42.1%), and deficient incentives(28.1%) are the main barriers to implementing AS. We underscore the existing differences in IPC and AS programs' implementation, team composition, and faced barriers. Continuous collaboration and sharing best practices on APM is needed. The role of regional and international organizations should be encouraged. Global support for capacity building of healthcare practitioners is warranted. (C) 2022 Published by Elsevier Ltd on behalf of King Saud Bin Abdulaziz University for Health Sciences

Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study

BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P &lt; 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P &lt; 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223

The reverse role of the hypothalamic paraventricular (PVN) and arcuate (ARC) nuclei in the central serotonergic regulation of the liver cytochrome P450 isoform CYP2C11

Our recent work showed that the brain serotonergic system negatively regulated liver cytochrome P450. The aim of our present research was to study the effect of damage to the serotonergic innervation of the paraventricular (PVN) or arcuate nuclei (ARC) of the hypothalamus on the neuroendocrine regulation of cytochrome P450 (CYP). Male rats received bilateral injections of the serotonergic neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) into the PVN or ARC. One week after the injection brain neurotransmitters, serum hormones (growth hormone, testosterone, corticosterone, thyroid hormones), pituitary somatostatin and liver cytochrome P450 expression and activity were measured. Lesion of the serotonergic innervation of the PVN decreased serotonin level in the hypothalamic area containing the PVN, causing an increase in growth hormone and testosterone concentrations in the blood and, subsequently, an increase in the expression (mRNA and protein level) and activity of isoform CYP2C11 in the liver. In contrast, damage to the serotonergic innervation of the ARC, which caused a decrease in serotonin level in the hypothalamic area containing the ARC, reduced the concentration of growth hormone and the expression and activity of CYP2C11. In conclusion, the obtained results show a reverse effect of the serotonergic innervation of the hypothalamic paraventricular (a negative effect) and arcuate nuclei (a positive effect) on growth hormone secretion and growth hormone-dependent CYP2C11 expression. They also suggest that CYP2C11 expression may be changed by drugs acting via the serotonergic system, their effect depending on their mechanism of action, route of administration (intracerebral, peripheral) and distribution pattern within the hypothalamus

Validation of rs2956540:G&gt;C and rs3735520:G&gt;A association with keratoconus in a population of European descent

Corneal ectasias, among which keratoconus (KC) is the single most common entity, are one of the most frequent reasons for corneal grafting in developed countries and a threatening complication of laser in situ keratomileusis. Genome-wide association studies have previously found lysyl oxidase (LOX) and hepatocyte growth factor (HGF) associated with susceptibility to KC development. The aim of our study was to validate the effects of seven single-nucleotide polymorphisms (SNPs) within LOX and HGF over KC. Unrelated Czech cases with KC of European descent (108 males and 57 females, 165 cases in total) and 193 population and gender-matched controls were genotyped using Kompetitive Allele Specific PCR assays. Fisher's exact tests were used to assess the strength of associations. Evidence for association was found for both of the tested loci. It was strongest for rs3735520:G>A near HGF (allelic test odds ratio (OR)=1.45; 95% confidence interval (CI), 1.06–1.98; P=0.018) with A allele being a risk factor and rs2956540:G>C (OR=0.69; 95% CI, 0.50–0.96; P=0.024) within LOX with C allele having a protective effect. This first independent association validation of rs2956540:G>C and rs3735520:G>A suggests that these SNPs may serve as genetic risk markers for KC in individuals of European descent

Replication of SNP associations with keratoconus in a Czech cohort

<div><p>Introduction</p><p>Keratoconus is a relatively frequent disease leading to severe visual impairment. Existing therapies are imperfect and clinical management may benefit from improved understanding of mechanisms leading to this disease. We aim to investigate the replication of 11 single nucleotide polymorphisms (SNPs) with keratoconus.</p><p>Methods</p><p>SNPs from loci previously found in association with keratoconus were genotyped in 165 keratoconus cases of Caucasian Czech origin (108 males and 57 females) and 193 population and gender-matched controls. They included rs1536482 (<i>COL5A1)</i>, rs4839200 (<i>KCND3)</i>, rs757219 and rs214884 (<i>IMMP2L)</i>, rs1328083 and rs1328089 (<i>DAOA)</i>, rs2721051 (<i>FOXO1)</i>, rs4894535 (<i>FNDC3B)</i>, rs4954218 (<i>MAP3K19</i>, <i>RAB3GAP1)</i>, rs9938149 (<i>ZNF469)</i> and rs1324183 (<i>MPDZ)</i>. A case-control association analysis was assessed using Fisher’s exact tests.</p><p>Results</p><p>The strongest association was found for rs1324183 (allelic test OR = 1.58; 95% CI, 1.10–2.24, p = 0.01). Statistically significant values were also obtained for rs2721051 (allelic test OR = 1.72; 95% CI, 1.07–2.77, p = 0.025) and rs4954218 (allelic test OR = 1.53; 95% CI, 1.01–2.34; p = 0.047) which showed an opposite effect direction compared to previously reported one.</p><p>Conclusion</p><p>Independent replication of association between two SNPs and keratoconus supports the association of these loci with the risks for the disease development, while the effect of rs4954218 warrants further investigation. Understanding the role of the genetic factors involved in keratoconus etiopathogenesis may facilitate development of novel therapies and an early detection.</p></div

Analyzed SNPs and results of their association testing with keratoconus in a Czech case-control panel.

<p>Analyzed SNPs and results of their association testing with keratoconus in a Czech case-control panel.</p

Increased nuclear DNA damage precedes mitochondrial dysfunction in peripheral blood mononuclear cells from Huntington's disease patients

Huntington’s disease (HD) is a progressive neurodegenerative disorder primarily afecting the basal ganglia and is caused by expanded CAG repeats in the huntingtin gene. Except for CAG sizing, mitochondrial and nuclear DNA (mtDNA and nDNA) parameters have not yet proven to be representative biomarkers for disease and future therapy. Here, we identifed a general suppression of genes associated with aerobic metabolism in peripheral blood mononuclear cells (PBMCs) from HD patients compared to controls. In HD, the complex II subunit SDHB was lowered although not sufciently to afect complex II activity. Nevertheless, we found decreased level of factors associated with mitochondrial biogenesis and an associated dampening of the mitochondrial DNA damage frequency in HD, implying an early defect in mitochondrial activity. In contrast to mtDNA, nDNA from HD patients was four-fold more modifed than controls and demonstrated that nDNA integrity is severely reduced in HD. Interestingly, the level of nDNA damage correlated inversely with the total functional capacity (TFC) score; an established functional score of HD. Our data show that PBMCs are a promising source to monitor HD progression and highlights nDNA damage and diverging mitochondrial and nuclear genome responses representing early cellular impairments in HD

Vascular Effects of Low-Dose ACE2 Inhibitor MLN-4760&mdash;Benefit or Detriment in Essential Hypertension?

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infects host cells through angiotensin-converting enzyme 2 (ACE2). Concurrently, the product of ACE2 action, angiotensin 1&ndash;7 (Ang 1&ndash;7), binds to Mas receptors within the cardiovascular system and provides protective effects. Therefore, it is crucial to reveal the role of ACE2 inhibition, especially within pre-existing cardiovascular pathologies. In our study, we imitated the action of SARS-CoV-2 in organisms using the low dose of the ACE2 inhibitor MLN-4760 with the aim of investigating to what degree ACE2 inhibition is detrimental to the cardiovascular system of spontaneously hypertensive rats (SHRs), which represent a model of human essential hypertension. Our study revealed the complex action of MLN-4760 in SHRs. On the one hand, we found that MLN-4760 had (1) (pro)obesogenic effects that negatively correlated with alternative renin-angiotensin system activity and Ang 1&ndash;7 in plasma, (2) negative effects on ACE1 inhibitor (captopril) action, (3) detrimental effects on the small arteries function and (4) anti-angiogenic effect in the model of chick chorioallantoic membrane. On the other hand, MLN-4760 induced compensatory mechanisms involving strengthened Mas receptor-, nitric oxide- and hydrogen sulfide-mediated signal transduction in the aorta, which was associated with unchanged blood pressure, suggesting beneficial action of MLN-4760 when administered at a low dose