Altered Fhod3 expression involved in progressive high-frequency hearing loss via dysregulation of actin polymerization stoichiometry in the cuticular plate.

Age-related hearing loss (ARHL) is a common sensory impairment with complex underlying mechanisms. In our previous study, we performed a meta-analysis of genome-wide association studies (GWAS) in mice and identified a novel locus on chromosome 18 associated with ARHL specifically linked to a 32 kHz tone burst stimulus. Consequently, we investigated the role of Formin Homology 2 Domain Containing 3 (Fhod3), a newly discovered candidate gene for ARHL based on the GWAS results. We observed Fhod3 expression in auditory hair cells (HCs) primarily localized at the cuticular plate (CP). To understand the functional implications of Fhod3 in the cochlea, we generated Fhod3 overexpression mice (Pax2-Cre+/-; Fhod3Tg/+) (TG) and HC-specific conditional knockout mice (Atoh1-Cre+/-; Fhod3fl/fl) (KO). Audiological assessments in TG mice demonstrated progressive high-frequency hearing loss, characterized by predominant loss of outer hair cells, and a decreased phalloidin intensities of CP. Ultrastructural analysis revealed loss of the shortest row of stereocilia in the basal turn of the cochlea, and alterations in the cuticular plate surrounding stereocilia rootlets. Importantly, the hearing and HC phenotype in TG mice phenocopied that of the KO mice. These findings suggest that balanced expression of Fhod3 is critical for proper CP and stereocilia structure and function. Further investigation of Fhod3 related hearing impairment mechanisms may lend new insight towards the myriad mechanisms underlying ARHL, which in turn could facilitate the development of therapeutic strategies for ARHL.

Proteome Landscape of Epithelial-to-Mesenchymal Transition (EMT) of Retinal Pigment Epithelium Shares Commonalities With Malignancy-Associated EMT.

Stress and injury to the retinal pigment epithelium (RPE) often lead to dedifferentiation and epithelial-to-mesenchymal transition (EMT). These processes have been implicated in several retinal diseases, including proliferative vitreoretinopathy, diabetic retinopathy, and age-related macular degeneration. Despite the importance of RPE-EMT and the large body of data characterizing malignancy-related EMT, comprehensive proteomic studies to define the protein changes and pathways underlying RPE-EMT have not been reported. This study sought to investigate the temporal protein expression changes that occur in a human-induced pluripotent stem cell-based RPE-EMT model. We utilized multiplexed isobaric tandem mass tag labeling followed by high-resolution tandem MS for precise and in-depth quantification of the RPE-EMT proteome. We have identified and quantified 7937 protein groups in our tandem mass tag-based MS analysis. We observed a total of 532 proteins that are differentially regulated during RPE-EMT. Furthermore, we integrated our proteomic data with prior transcriptomic (RNA-Seq) data to provide additional insights into RPE-EMT mechanisms. To validate these results, we have performed a label-free single-shot data-independent acquisition MS study. Our integrated analysis indicates both the commonality and uniqueness of RPE-EMT compared with malignancy-associated EMT. Our comparative analysis also revealed that multiple age-related macular degeneration-associated risk factors are differentially regulated during RPE-EMT. Together, our integrated dataset provides a comprehensive RPE-EMT atlas and resource for understanding the molecular signaling events and associated biological pathways that underlie RPE-EMT onset. This resource has already facilitated the identification of chemical modulators that could inhibit RPE-EMT, and it will hopefully aid in ongoing efforts to develop EMT inhibition as an approach for the treatment of retinal disease.

Inhibition of GCK-IV kinases dissociates cell death and axon regeneration in CNS neurons.

Axon injury is a hallmark of many neurodegenerative diseases, often resulting in neuronal cell death and functional impairment. Dual leucine zipper kinase (DLK) has emerged as a key mediator of this process. However, while DLK inhibition is robustly protective in a wide range of neurodegenerative disease models, it also inhibits axonal regeneration. Indeed, there are no genetic perturbations that are known to both improve long-term survival and promote regeneration. To identify such a neuroprotective target, we conducted a set of complementary high-throughput screens using a protein kinase inhibitor library in human stem cell-derived retinal ganglion cells (hRGCs). Overlapping compounds that promoted both neuroprotection and neurite outgrowth were bioinformatically deconvoluted to identify specific kinases that regulated neuronal death and axon regeneration. This work identified the role of germinal cell kinase four (GCK-IV) kinases in cell death and additionally revealed their unexpected activity in suppressing axon regeneration. Using an adeno-associated virus (AAV) approach, coupled with genome editing, we validated that GCK-IV kinase knockout improves neuronal survival, comparable to that of DLK knockout, while simultaneously promoting axon regeneration. Finally, we also found that GCK-IV kinase inhibition also prevented the attrition of RGCs in developing retinal organoid cultures without compromising axon outgrowth, addressing a major issue in the field of stem cell-derived retinas. Together, these results demonstrate a role for the GCK-IV kinases in dissociating the cell death and axonal outgrowth in neurons and their druggability provides for therapeutic options for neurodegenerative diseases.

Detection and validation of novel mutations in MERTK in a simplex case of retinal degeneration using WGS and hiPSC-RPEs model.

Inherited retinal degenerations (IRDs) are a group of genetically heterogeneous conditions with a broad phenotypic heterogeneity. Here, we report detection and validation of the underlying cause of progressive retinal degeneration in a nuclear family of European descent with a single affected individual. Whole genome sequencing of the proband and her unaffected sibling identified a novel intron 8 donor splice site variant (c.1296 + 1G>A) and a novel 731 base pair deletion encompassing exon 9 (Chr2:g.112751488_112752218 del) resulting in c.1297_1451del; p.K433_G484fsTer3 in the Mer tyrosine kinase protooncogene (MERTK), which is highly expressed in the retinal pigment epithelium (RPE). The proband carried both variants in the heterozygous state, which segregated with disease in the pedigree. These MERTK variants are predicted to result in the defective splicing of exon 8 and loss of exon 9 respectively. To evaluate the impact of these novel variants, peripheral blood mononuclear cells of the proband and her parents were reprogrammed to humaninduced pluripotent stem cell (hiPSC) lines, which were subsequently differentiated to hiPSC-RPE. Analysis of the proband's hiPSC-RPE revealed the absence of both MERTK transcript and its respective protein as well as abnormal phagocytosis when compared with the parental hiPSC-RPE. In summary, whole genome sequencing identified novel compound heterozygous variants in MERTK as the underlying cause of progressive retinal degeneration in a simplex case. Further, analysis using an hiPSC-RPE model established the functional impact of novel MERTK mutations and revealed the potential mechanism underlying pathology in the proband.

Esophageal Adenocarcinoma After Antireflux Surgery in a Cohort Study From the 5 Nordic Countries.

OBJECTIVE: We aimed to clarify the long-term risk development of EAC after antireflux surgery. SUMMARY OF BACKGROUND DATA: Gastroesophageal reflux disease (GERD) increases EAC risk, but whether antireflux surgery prevents EAC is uncertain. METHODS: Multinational, population-based cohort study including individuals with GERD from all 5 Nordic countries in 1964-2014. First, EAC risk after antireflux surgery in the cohort was compared with the corresponding background population by calculating standardized incidence ratios (SIRs) with 95% confidence intervals (95% CIs). Second, multivariable Cox proportional hazards regression, providing hazard ratios (HRs) with 95% CIs, compared EAC risk in GERD patients with antireflux surgery with those with nonsurgical treatment. RESULTS: Among 942,071 GERD patients, 48,863 underwent surgery and 893,208 did not. Compared to the corresponding background population, EAC risk did not decrease after antireflux surgery [SIR 4.90 (95% CI 3.62-6.47) 1-<5 years and SIR 4.57 (95% CI 3.44-5.95) ≥15 years after surgery]. Similarly, no decrease was found for patients with severe GERD (esophagitis or Barrett esophagus) after surgery [SIR 6.09 (95% CI 4.39-8.23) 1-<5 years and SIR = 5.27 (95% CI 3.73-7.23) ≥15 years]. The HRs of EAC were stable comparing the surgery group with the nonsurgery group with GERD [HR 1.71 (95% CI 1.26-2.33) 1-<5 years and HR 1.69 (95% CI 1.24-2.30) ≥15 years after treatment], or for severe GERD [HR 1.56 (95% CI 1.11-2.20) 1-<5 years and HR 1.57 (95% CI 1.08-2.26) ≥15 years after treatment]. CONCLUSIONS: Surgical treatment of GERD does not seem to reduce EAC risk.

Three-dimensional automated reporter quantification (3D-ARQ) technology enables quantitative screening in retinal organoids.

The advent of stem cell-derived retinal organoids has brought forth unprecedented opportunities for developmental and physiological studies, while presenting new therapeutic promise for retinal degenerative diseases. From a translational perspective, organoid systems provide exciting new prospects for drug discovery, offering the possibility to perform compound screening in a three-dimensional (3D) human tissue context that resembles the native histoarchitecture and to some extent recapitulates cellular interactions. However, inherent variability issues and a general lack of robust quantitative technologies for analyzing organoids on a large scale pose severe limitations for their use in translational applications. To address this need, we have developed a screening platform that enables accurate quantification of fluorescent reporters in complex human iPSC-derived retinal organoids. This platform incorporates a fluorescence microplate reader that allows xyz-dimensional detection and fine-tuned wavelength selection. We have established optimal parameters for fluorescent reporter signal detection, devised methods to compensate for organoid size variability, evaluated performance and sensitivity parameters, and validated this technology for functional applications.

Sex differences in the prognosis after surgery for esophageal squamous cell carcinoma and adenocarcinoma.

Some investigations suggest a better prognosis in women compared to men with esophageal cancer but these differences are uncertain. The aim of our study was to clarify whether sex influences the prognosis after esophagectomy for esophageal squamous cell carcinoma and esophageal adenocarcinoma. A population-based and nationwide cohort study included almost all patients who underwent esophagectomy for esophageal cancer in Sweden in 1987-2010, with follow-up until 2016. Patients' sex was analyzed in relation to risk of mortality. Multivariable Cox regression provided hazard ratios (HR) with 95% confidence intervals (CI), adjusted for calendar period, age, education, comorbidity, tumor stage, neoadjuvant therapy, and surgeon volume. Among 1,816 participants, 1,024 (56%) had esophageal squamous cell carcinoma (355 [35%] women), and 792 (44%) had esophageal adenocarcinoma (103 [13%] women). Compared to men, women had a decreased overall all-cause mortality in esophageal squamous cell carcinoma (HR = 0.73, 95% CI 0.63-0.85). Stratified analyses showed decreased mortality limited to women aged >55 years (HR = 0.71, 95% CI 0.61-0.83), but in all tumor stages, particularly stages 0-I (HR = 0.54, 95% CI 0.37-0.79). Women also had decreased 90-day all-cause mortality, 5-year all-cause mortality, and 5-year disease-specific mortality in esophageal squamous cell carcinoma compared to men. For esophageal adenocarcinoma, no sex differences were found for any of the mortality outcomes. Thus, women who undergo esophagectomy for esophageal squamous cell carcinoma seem to have better prognosis than men, especially those with early tumor stages, whereas no sex differences in prognosis were found for esophageal adenocarcinoma.

All-cause and cancer-specific mortality in GORD in a population-based cohort study (the HUNT study).

OBJECTIVE: Gastro-oesophageal reflux is a public health concern which could have associated oesophageal complications, including adenocarcinoma, and possibly also head-and-neck and lung cancers. The aim of this study was to test the hypothesis that reflux increases all-cause and cancer-specific mortalities in an unselected cohort. DESIGN: The Nord-Trøndelag health study (HUNT), a Norwegian population-based cohort study, was used to identify individuals with and without reflux in 1995-1997 and 2006-2008, with follow-up until 2014. All-cause mortality and cancer-specific mortality were assessed from the Norwegian Cause of Death Registry and Cancer Registry. Multivariable Cox regression was used to calculate HRs with 95% CIs for mortality with adjustments for potential confounders. RESULTS: We included 4758 participants with severe reflux symptoms and 51 381 participants without reflux symptoms, contributing 60 323 and 747 239 person-years at risk, respectively. Severe reflux was not associated with all-cause mortality, overall cancer-specific mortality or mortality in cancer of the head-and-neck or lung. However, for men with severe reflux a sixfold increase in oesophageal adenocarcinoma-specific mortality was found (HR 6.09, 95% CI 2.33 to 15.93) and the mortality rate was 0.27 per 1000 person-years. For women, the corresponding mortality was not significantly increased (HR 3.68, 95% CI 0.88 to 15.27) and the mortality rate was 0.05 per 1000 person-years. CONCLUSIONS: Individuals with severe reflux symptoms do not seem to have increased all-cause mortality or overall cancer-specific mortality. Although the absolute risk is small, individuals with severe reflux symptoms have a clearly increased oesophageal adenocarcinoma-specific mortality.

Pax6 is essential for the generation of late-born retinal neurons and for inhibition of photoreceptor-fate during late stages of retinogenesis.

In the developing retina, as in other regions of the CNS, neural progenitors give rise to individual cell types during discrete temporal windows. Pax6 is expressed in retinal progenitor cells (RPCs) throughout the course of retinogenesis, and has been shown to be required during early retinogenesis for generation of most early-born cell types. In this study, we examined the function of Pax6 in postnatal mouse retinal development. We found that Pax6 is essential for the generation of late-born interneurons, while inhibiting photoreceptor differentiation. Generation of bipolar interneurons requires Pax6 expression in RPCs, while Pax6 is required for the generation of glycinergic, but not for GABAergic or non-GABAergic-non-glycinergic (nGnG) amacrine cell subtypes. In contrast, overexpression of either full-length Pax6 or its 5a isoform in RPCs induces formation of cells with nGnG amacrine features, and suppresses generation of other inner retinal cell types. Moreover, overexpression of both Pax6 variants prevents photoreceptor differentiation, most likely by inhibiting Crx expression. Taken together, these data show that Pax6 acts in RPCs to control differentiation of multiple late-born neuronal cell types.

Time latencies of Helicobacter pylori eradication after peptic ulcer and risk of recurrent ulcer, ulcer adverse events, and gastric cancer: a population-based cohort study.

BACKGROUND AND AIMS: Helicobacter pylori is associated with peptic ulcer disease and gastric cancer. Therefore we wanted to test how various lengths of delays in H pylori eradication therapy influence the risk of recurrent peptic ulcer, ulcer adverse events, and gastric cancer. METHODS: This population-based nationwide Swedish cohort study included 29,032 patients receiving H pylori eradication therapy after peptic ulcer disease in 2005 to 2013. Predefined time intervals between date of peptic ulcer diagnosis and date of eradication therapy were analyzed in relation to study outcomes. Cox regression provided hazard ratios (HRs) and 95% confidence intervals (95% CIs), adjusted for age, sex, comorbidity, history of ulcer disease, use of ulcerogenic drugs, and use of proton pump inhibitors (PPIs). RESULTS: Compared with eradication therapy within 7 days of peptic ulcer diagnosis, eradication therapy within 8 to 30, 31 to 60, 61 to 365, and >365 days corresponded with HRs of recurrent ulcer of 1.17 (95% CI, 1.08-1.25), 2.37 (95% CI, 2.16-2.59), 2.96 (95% CI, 2.76-3.16), and 3.55 (95% CI, 3.33-3.79), respectively. The corresponding HRs for complicated ulcer were 1.55 (95% CI, 1.35-1.78), 3.19 (95% CI, 2.69-3.78), 4.00 (95% CI, 3.51-4.55), and 6.14, (95% CI, 5.47-6.89), respectively. For gastric cancer the corresponding HRs were .85 (95% CI, .32-2.23), 1.31 (95% CI, .31-5.54), 3.64 (95% CI, 1.55-8.56), and 4.71 (95% CI, 2.36-9.38), respectively. CONCLUSIONS: Delays in H pylori eradication therapy after peptic ulcer diagnosis time-dependently increase the risk of recurrent ulcer, even more so for complicated ulcer, starting from delays of 8 to 30 days.

A Triple-Fluorophore-Labeled Nucleic Acid pH Nanosensor to Investigate Non-viral Gene Delivery.

There is a need for new tools to better quantify intracellular delivery barriers in high-throughput and high-content ways. Here, we synthesized a triple-fluorophore-labeled nucleic acid pH nanosensor for measuring intracellular pH of exogenous DNA at specific time points in a high-throughput manner by flow cytometry following non-viral transfection. By including two pH-sensitive fluorophores and one pH-insensitive fluorophore in the nanosensor, detection of pH was possible over the full physiological range. We further assessed possible correlation between intracellular pH of delivered DNA, cellular uptake of DNA, and DNA reporter gene expression at 24 hr post-transfection for poly-L-lysine and branched polyethylenimine polyplex nanoparticles. While successful transfection was shown to clearly depend on median cellular pH of delivered DNA at the cell population level, surprisingly, on an individual cell basis, there was no significant correlation between intracellular pH and transfection efficacy. To our knowledge, this is the first reported instance of high-throughput single-cell analysis between cellular uptake of DNA, intracellular pH of delivered DNA, and gene expression of the delivered DNA. Using the nanosensor, we demonstrate that the ability of polymeric nanoparticles to avoid an acidic environment is necessary, but not sufficient, for successful transfection.

Small-molecule-directed, efficient generation of retinal pigment epithelium from human pluripotent stem cells.

Age-related macular degeneration (AMD) is associated with dysfunction and death of retinal pigment epithelial (RPE) cells. Cell-based approaches using RPE-like cells derived from human pluripotent stem cells (hPSCs) are being developed for AMD treatment. However, most efficient RPE differentiation protocols rely on complex, stepwise treatments and addition of growth factors, whereas small-molecule-only approaches developed to date display reduced yields. To identify new compounds that promote RPE differentiation, we developed and performed a high-throughput quantitative PCR screen complemented by a novel orthogonal human induced pluripotent stem cell (hiPSC)-based RPE reporter assay. Chetomin, an inhibitor of hypoxia-inducible factors, was found to strongly increase RPE differentiation; combination with nicotinamide resulted in conversion of over one-half of the differentiating cells into RPE. Single passage of the whole culture yielded a highly pure hPSC-RPE cell population that displayed many of the morphological, molecular, and functional characteristics of native RPE.

Nordic registry-based cohort studies: Possibilities and pitfalls when combining Nordic registry data.

AIMS: All five Nordic countries (Denmark, Finland, Iceland, Norway and Sweden) have nationwide registries with similar data structure and validity, as well as personal identity numbers enabling linkage between registries. These resources provide opportunities for medical research that is based on large registry-based cohort studies with long and complete follow-up. This review describes practical aspects, opportunities and challenges encountered when setting up all-Nordic registry-based cohort studies. METHODS: Relevant articles describing registries often used for medical research in the Nordic countries were retrieved. Further, our experiences of conducting this type of study, including planning, acquiring permissions, data retrieval and data cleaning and handling, and the possibilities and challenges we have encountered are described. RESULTS: Combining data from the Nordic countries makes it possible to create large and powerful cohorts. The main challenges include obtaining all permissions within each country, usually in the local language, and retrieving the data. These challenges emphasise the importance of having experienced collaborators within each country. Following the acquisition of data, data management requires the understanding of the differences between the variables to be used in the various countries. A concern is the long time required between initiation and completion. CONCLUSIONS: Nationwide Nordic registries can be combined into cohorts with high validity and statistical power, but the considerable expertise, workload and time required to complete such cohorts should not be underestimated.

Association Between Laparoscopic Antireflux Surgery and Recurrence of Gastroesophageal Reflux.

Importance: Cohort studies, mainly based on questionnaires and interviews, have reported high rates of reflux recurrence after antireflux surgery, which may have contributed to a decline in its use. Reflux recurrence after laparoscopic antireflux surgery has not been assessed in a long-term population-based study of unselected patients. Objectives: To determine the risk of reflux recurrence after laparoscopic antireflux surgery and to identify risk factors for recurrence. Design and Setting: Nationwide population-based retrospective cohort study in Sweden between January 1, 2005, and December 31, 2014, based on all Swedish health care and including 2655 patients who underwent laparoscopic antireflux surgery according to the Swedish Patient Registry. Their records were linked to the Swedish Causes of Death Registry and Prescribed Drug Registry. Exposures: Primary laparoscopic antireflux surgery due to gastroesophageal reflux disease in adults (>18 years). Main Outcomes and Measures: The outcome was recurrence of reflux, defined as use of antireflux medication (proton pump inhibitors or histamine2 receptor antagonists for >6 months) or secondary antireflux surgery. Multivariable Cox regression was used to assess risk factors for reflux recurrence. Results: Among all 2655 patients who underwent antireflux surgery (median age, 51.0 years; interquartile range, 40.0-61.0 years; 1354 men [51.0%]) and were followed up for a median of 5.6 years, 470 patients (17.7%) had reflux recurrence; 393 (83.6%) received long-term antireflux medication and 77 (16.4%) underwent secondary antireflux surgery. Risk factors for reflux recurrence included female sex (hazard ratio [HR], 1.57 [95% CI, 1.29-1.90]; 286 of 1301 women [22.0%] and 184 of 1354 men [13.6%] had recurrence of reflux), older age (HR, 1.41 [95% CI, 1.10-1.81] for age ≥61 years compared with ≤45 years; recurrence among 156 of 715 patients and 133 of 989 patients, respectively), and comorbidity (HR, 1.36 [95% CI, 1.13-1.65] for Charlson comorbidity index score ≥1 compared with 0; recurrence among 180 of 804 patients and 290 of 1851 patients, respectively). Hospital volume of antireflux surgery was not associated with risk of reflux recurrence (HR, 1.09 [95% CI, 0.77-1.53] for hospital volume ≤24 surgeries compared with ≥76 surgeries; recurrence among 38 of 266 patients [14.3%] and 271 of 1526 patients [17.8%], respectively). Conclusions and Relevance: Among patients who underwent primary laparoscopic antireflux surgery, 17.7% experienced recurrent gastroesophageal reflux requiring long-term medication use or secondary antireflux surgery. Risk factors for recurrence were older age, female sex, and comorbidity. Laparoscopic antireflux surgery was associated with a relatively high rate of recurrent gastroesophageal reflux disease requiring treatment, diminishing some of the benefits of the operation.

Haemochromatosis and gastrointestinal cancer.

Iron overload in patients with haemochromatosis is a strong risk factor for liver cancer, but its influence on other gastrointestinal cancer risk is unclear. The aim was to assess the relative risk of luminal gastrointestinal cancer among patients diagnosed with haemochromatosis. This population-based, nationwide Swedish cohort study included patients with haemochromatosis in Sweden in 1965-2013. The incidence of gastrointestinal cancers was assessed through the Swedish Cancer Registry. The measure of relative risk was the standardised incidence ratio (SIR) with 95% confidence interval (CI), that is, the ratio of the observed number of gastrointestinal cancers in the haemochromatosis cohort divided by the expected number of such cancers, calculated from the entire corresponding background population of Sweden. Among 6,849 patients in the haemochromatosis cohort with up to 48 years of follow-up, the SIRs were 3-fold increased for oesophageal squamous cell carcinoma (SIR = 3.2, 95% CI 1.3-6.6; n = 7) and 40% increased for colon adenocarcinoma (SIR = 1.4, 95% CI 1.1-1.9; n = 54). No associations were found between haemochromatosis and the risk of adenocarcinoma of the oesophagus (SIR = 0.5, 95% CI 0.0-2.5; n = 1), stomach (SIR = 0.7, 95% CI 0.3-1.4; n = 8), small bowel (SIR = 1.2, 95% CI 0.0-6.7; n = 1) or rectum (SIR = 1.0, 95% CI 0.6-1.6; n = 21). These findings indicate that haemochromatosis increases the risk of oesophageal squamous cell carcinoma and colon adenocarcinoma, but might not influence the risk of other types of luminal gastrointestinal cancer. These findings should encourage further research examining the role of iron overload in cancer aetiology.

Effect of oral diclofenac intake on faecal calprotectin.

BACKGROUND: NSAIDs are a known source of increased faecal calprotectin (FC) levels. Currently, there is a lack of knowledge about how long it takes for an increased FC level to return to normal after NSAID intake. OBJECTIVE: The aim was to investigate how oral diclofenac intake affects FC levels and assess how long it takes for an increased FC level to return to normal after oral diclofenac intake. MATERIAL AND METHODS: Thirty healthy volunteers received diclofenac 50 mg three times daily for 14 days. Participants provided a stool sample on Days 0, 2, 4, 7, 14 during intake and Days 17, 21, 28 after discontinuation. FC levels were then followed at 7-day intervals until normalization. RESULTS: During diclofenac intake, eight participants (27%) had FC levels exceeding the upper limit of normal (median, 76 µg/g; range, 60-958 µg/g), corresponding to 8.3% of measurements. FC was not constantly increased and became normal in most participants during diclofenac intake. FC levels were on average significantly higher during intake (M = 9.5, interquartile range (IQR) = 13.4) than on baseline (M = 7.5, IQR = 0.0), p = 0.003. After discontinuation, two participants had increased FC on Days 17 and 21, respectively. No significant differences in FC levels were found between baseline and measurements after discontinuation. Two weeks after discontinuation, all participants had normal FC levels. CONCLUSIONS: Short-term oral diclofenac intake is associated with increased FC levels. However, the likelihood of an increased test result is low. Our results suggest that 2 weeks of diclofenac withdrawal is sufficient to get an uninfluenced FC test result.

Inactivation of the microRNA-183/96/182 cluster results in syndromic retinal degeneration.

The microRNA-183/96/182 cluster is highly expressed in the retina and other sensory organs. To uncover its in vivo functions in the retina, we generated a knockout mouse model, designated "miR-183C(GT/GT)," using a gene-trap embryonic stem cell clone. We provide evidence that inactivation of the cluster results in early-onset and progressive synaptic defects of the photoreceptors, leading to abnormalities of scotopic and photopic electroretinograms with decreased b-wave amplitude as the primary defect and progressive retinal degeneration. In addition, inactivation of the miR-183/96/182 cluster resulted in global changes in retinal gene expression, with enrichment of genes important for synaptogenesis, synaptic transmission, photoreceptor morphogenesis, and phototransduction, suggesting that the miR-183/96/182 cluster plays important roles in postnatal functional differentiation and synaptic connectivity of photoreceptors.

Transcription factor SOX9 plays a key role in the regulation of visual cycle gene expression in the retinal pigment epithelium.

The retinal pigment epithelium (RPE) performs specialized functions to support retinal photoreceptors, including regeneration of the visual chromophore. Enzymes and carrier proteins in the visual cycle function sequentially to regenerate and continuously supply 11-cis-retinal to retinal photoreceptor cells. However, it is unknown how the expression of the visual cycle genes is coordinated at the transcriptional level. Here, we show that the proximal upstream regions of six visual cycle genes contain chromatin-accessible sex-determining region Y box (SOX) binding sites, that SOX9 and LIM homeobox 2 (LHX2) are coexpressed in the nuclei of mature RPE cells, and that SOX9 acts synergistically with orthodenticle homeobox 2 (OTX2) to activate the RPE65 and retinaldehyde binding protein 1 (RLBP1) promoters and acts synergistically with LHX2 to activate the retinal G protein-coupled receptor (RGR) promoter. ChIP reveals that SOX9 and OTX2 bind to the promoter regions of RPE65, RLBP1, and RGR and that LHX2 binds to those of RPE65 and RGR in bovine RPE. ChIP with human fetal RPE cells shows that SOX9 and OTX2 also bind to the human RPE65, RLBP1, and RGR promoters. Conditional inactivation of Sox9 in mouse RPE results in reduced expression of several visual cycle genes, most dramatically Rpe65 and Rgr. Furthermore, bioinformatic analysis predicts that multiple common microRNAs (miRNAs) regulate visual cycle genes, and cotransfection of miRNA mimics with luciferase reporter constructs validated some of the predicted miRNAs. These results implicate SOX9 as a key regulator of visual cycle genes, reveal for the first time the functional role of LHX2 in the RPE, and suggest the possible regulation of visual cycle genes by common miRNAs.

Modeling retinal dystrophies using patient-derived induced pluripotent stem cells.

Retinal degenerative disease involving photoreceptor (PR) cell loss results in permanent vision loss and often blindness. Generation of induced pluripotent stem cell (iPSC)-derived retinal cells and tissues from individuals with retinal dystrophies is a relatively new and promising method for studying retinal degeneration mechanisms in vitro. Recent advancements in strategies to differentiate human iPSCs (hiPSCs) into 3D retinal eyecups with a strong resemblance to the mature retina raise the possibility that this system could offer a reliable model for translational drug studies. However, despite the potential benefits, there are challenges that remain to be overcome before stem-cell-derived retinal eyecups can be routinely used to model human retinal diseases. This chapter will discuss both the potential of these 3D eyecup approaches and the nature of some of the challenges that remain.

Loss of GTF2I promotes neuronal apoptosis and synaptic reduction in human cellular models of neurodevelopment.

Individuals with Williams syndrome (WS), a neurodevelopmental disorder caused by hemizygous loss of 26-28 genes at 7q11.23, characteristically portray a hypersocial phenotype. Copy-number variations and mutations in one of these genes, GTF2I, are associated with altered sociality and are proposed to underlie hypersociality in WS. However, the contribution of GTF2I to human neurodevelopment remains poorly understood. Here, human cellular models of neurodevelopment, including neural progenitors, neurons, and three-dimensional cortical organoids, are differentiated from CRISPR-Cas9-edited GTF2I-knockout (GTF2I-KO) pluripotent stem cells to investigate the role of GTF2I in human neurodevelopment. GTF2I-KO progenitors exhibit increased proliferation and cell-cycle alterations. Cortical organoids and neurons demonstrate increased cell death and synaptic dysregulation, including synaptic structural dysfunction and decreased electrophysiological activity on a multielectrode array. Our findings suggest that changes in synaptic circuit integrity may be a prominent mediator of the link between alterations in GTF2I and variation in the phenotypic expression of human sociality.