Purpose:Retinal ischemia in diabetic retinopathy (DR) is caused by the apoptosis of capillary pericytes and endothelial cells. In this study, we investigated the role of the Parkinson-associated protein DJ-1 (PARK7) in retinal capillary degeneration. Methods:DJ-1 levels were measured in diabetic and non-diabetic human retinas by immunostaining and Western blotting. Human retinal endothelial cells (HRECs) were cultured in high glucose or with a cytokine mixture (CM). The effect of inhibition of DJ-1 in HREC with isatin on Nε-carboxymethyl lysine (CML), inducible nitric oxide synthase (iNOS), nuclear factor erythroid 2-related factor (Nrf2), nuclear factor kappa (NF-κB), and cleaved caspase-3 was investigated. AAV2-PARK7, driven by the endothelial cell-specific Tie2 promoter, was intravitreally injected into the mouse's eyes, and the effect of the retinal transduced DJ-1 on capillaries was investigated following ischemia/reperfusion injury. Results:DJ-1 levels were observed to be reduced in human retinas with DR and in HREC cultured under high-glucose conditions. Isatin treatment increased the CML and iNOS levels in HREC. Treatment of HREC with CM promoted nuclear translocation of NF-κB and activation of caspase-3; co-treatment with isatin further exacerbated these effects. Isatin treatment significantly suppressed the CM-induced Nrf2 translocation in HREC. Intravitreal injection of AAV2-tie2-PARK7 resulted in high expression of DJ-1 in retinal capillaries and significantly reduced formation of acellular capillaries from ischemia/reperfusion injury. Conclusions:The results suggest that DJ-1 protects retinal capillary endothelial cells from damage caused by hyperglycemia and ischemia and that enhancing DJ-1 activity could be a strategy for mitigating early retinal damage in DR.

IntroductionRecurrent uveitis (RU), an autoimmune disease, is a leading cause of ocular detriment in humans and horses. Equine and human RU share many similarities including spontaneous disease and aberrant cytokine signaling. Reduced levels of SOCS1, a critical regulator of cytokine signaling, is associated with several autoimmune diseases. Topical administration of SOCS1-KIR, a peptide mimic of SOCS1, was previously correlated to reduced ocular pathologies within ERU patients.MethodsTo further assess the translational potential of a SOCS1 mimetic to treat RU, we assessed peptide-mediated modulation of immune functions in vitro, using equine peripheral blood mononuclear cells (PBMC), and in vivo through topical administration of SOCS1-KIR into the eyes of experimental (non-uveitic) horses. Equine PBMCs from non-uveitic control and ERU horses were cultured with or without SOCS1-KIR pretreatment, followed by 72 hours of mitogen stimulation. Proliferation was assessed using MTT, and cytokine production within cell supernatants was assessed by Luminex. SOCS1-KIR or carrier eye-drops were topically applied to experimental horse eyes twice daily for 21 days, followed by enucleation and isolation of ocular aqueous and vitreous humor. Histology was used to assess peptide treatment safety and localization within treated equine eyes. Cytokine secretion within aqueous humor and vitreous, isolated from experimental equine eyes, was measured by Luminex.ResultsFollowing SOCS1-KIR pretreatment, cell proliferation significantly decreased in control, but not ERU-derived PBMCs. Despite differential regulation of cellular proliferation, SOCS1-KIR significantly reduced TNFα and IL-10 secretion in PHA-stimulated control and ERU equine PBMC. SOCS1-KIR increased PBMC secretion of IL-8. Topically administered SOCS1-KIR was well tolerated. Although SOCS1-KIR was undetectable within the eye, topically treated equine eyes had significant reductions in TNFα and IL-10. Interestingly, we found that while SOCS1-KIR treatment reduced TNFα and IL-10 production in healthy and ERU PBMC, SOCS1-KIR differentially modulated proliferation, IP-10 production, and RANTES within these two groups suggesting possible differences in cell types or activation status.DiscussionTopical administration of a SOCS1 peptide mimic is safe to the equine eye and reduces ERU associated cytokines IL-10 and TNFα serving as potential biomarkers of drug efficacy in a future clinical trial.

Visual arrestin 1 (Arr1) is an essential protein for termination of the light response in photoreceptors. While mammalian Arr1s form dimers and tetramers at physiological concentrations in vitro, oligomerization in other vertebrates has not been studied. Here we examine self-association of Arr1 from two amphibian species, Xenopus laevis (xArr1) and Ambystoma tigrinum (salArr1). Sedimentation velocity analytical ultracentrifugation showed that xArr1 and salArr1 oligomerization is limited to dimers. The KD for dimer formation was 53 μM for xArr1 and 44 μM for salArr1, similar to the 69 μM KD for bovine Arr1 (bArr1) dimers. Mutations of orthologous amino acids important for mammalian Arr1 oligomerization had no impact on xArr1 dimerization. Crystallography showed that the fold of xArr1 closely resembles that of bArr1 and crystal structures in different space groups revealed two potential xArr1 dimer forms: a symmetric dimer with a C-domain interface (CC dimer), resembling the bArr1 solution dimer, and an asymmetric dimer with an N-domain/C-domain interface. Mutagenesis of residues predicted to interact in either of these two dimer forms yielded modest reduction in dimer affinity, suggesting that the dimer interfaces compete or are not unique. Indeed, small-angle X-ray scattering and protein painting data were consistent with a symmetric anti-parallel solution dimer (AP dimer) distinct from the assemblies observed by crystallography. Finally, a computational model evaluating xArr1 binding to compartment-specific partners and partitioning based on heterogeneity of available cytoplasmic spaces shows that Arr1 distribution in dark-adapted photoreceptors is largely explained by the excluded volume effect together with tuning by oligomerization.

BackgroundThe treatment of acute myeloid leukemia (AML) in older or unfit patients typically involves a regimen of venetoclax plus azacitidine (ven/aza). Toxicity and treatment responses are highly variable following treatment initiation and clinical decision-making continually evolves in response to these as treatment progresses. To improve clinical decision support (CDS) following treatment initiation, predictive models based on evolving and dynamic toxicities, disease responses, and other features should be developed. ObjectiveThis study aims to generate machine learning (ML)–based predictive models that incorporate individual predictors of overall survival (OS) for patients with AML, based on clinical events occurring after the initiation of ven/aza or 7+3 regimen. MethodsData from 221 patients with AML, who received either the ven/aza (n=101 patients) or 7+3 regimen (n=120 patients) as their initial induction therapy, were retrospectively analyzed. We performed stratified univariate and multivariate analyses to quantify the association between toxicities, hospital events, and short-term disease responses and OS for the 7+3 and ven/aza subgroups separately. We compared the estimates of confounders to assess potential effect modifications by treatment. 17 ML-based predictive models were developed. The optimal predictive models were selected based on their predictability and discriminability using cross-validation. Uncertainty in the estimation was assessed through bootstrapping. ResultsThe cumulative incidence of posttreatment toxicities varies between the ven/aza and 7+3 regimen. A variety of laboratory features and clinical events during the first 30 days were differentially associated with OS for the two treatments. An initial transfer to intensive care unit (ICU) worsened OS for 7+3 patients (aHR 1.18, 95% CI 1.10-1.28), while ICU readmission adversely affected OS for those on ven/aza (aHR 1.24, 95% CI 1.12-1.37). At the initial follow-up, achieving a morphologic leukemia free state (MLFS) did not affect OS for ven/aza (aHR 0.99, 95% CI 0.94-1.05), but worsened OS following 7+3 (aHR 1.16, 95% CI 1.01-1.31) compared to that of complete remission (CR). Having blasts over 5% at the initial follow-up negatively impacted OS for both 7+3 (P<.001) and ven/aza (P<.001) treated patients. A best response of CR and CR with incomplete recovery (CRi) was superior to MLFS and refractory disease after ven/aza (P<.001), whereas for 7+3, CR was superior to CRi, MLFS, and refractory disease (P<.001), indicating unequal outcomes. Treatment-specific predictive models, trained on 120 7+3 and 101 ven/aza patients using over 114 features, achieved survival AUCs over 0.70. ConclusionsOur findings indicate that toxicities, clinical events, and responses evolve differently in patients receiving ven/aza compared with that of 7+3 regimen. ML-based predictive models were shown to be a feasible strategy for CDS in both forms of AML treatment. If validated with larger and more diverse data sets, these findings could offer valuable insights for developing AML-CDS tools that leverage posttreatment clinical data.

Abstract Although it is known that SOCS1 can modulate JAK/STAT signaling through both its kinase inhibitory region (KIR) and SOCS box domain, and limit toll-like receptor (TLR) induced inflammation via the SOCS1 box domain, the relative contribution of the KIR domain to TLR regulation is not well understood. In this study, we utilized peptide mimics of SOCS1 KIR to study the effect of the KIR domain in modulating TLR7 and interferon γ (IFNγ) signaling in murine primary macrophages and cell lines. We found that SOCS1 KIR mimetics were able to inhibit, by up to 50%, the inflammatory signatures associated with TLR7 stimulation, IFNγ stimulation, and the enhanced IFNγ-induced gene signature, mediated by TLR7 and IFNγ co-treatment. While inhibition of IFNg mediated activation correlated with reduced Y701 phosphorylation on STAT1 and Y705 phosphorylation on STAT3, the inhibition of TLR7-induced inflammation and the TLR7-enhanced IFNγ-induced gene signature coincided with a reduction in both Y701 and S727 phosphorylation on the STAT1 transactivation domain. Altogether, we report for the first time a novel role of the SOCS1 KIR domain in regulating TLR7-mediated, and TLR7-enhanced IFNγ-mediated, inflammation.

Background: The treatment of acute myeloid leukemia (AML) in older or unfit patients typically involves a regimen ofvenetoclax plus azacitidine (ven/aza). Toxicity and treatment responses are highly variable following treatment initiation andclinical decision-making continually evolves in response to these as treatment progresses. To improve clinical decision support(CDS) following treatment initiation, predictive models based on evolving and dynamic toxicities, disease responses, and otherfeatures should be developed.Objective: This study aims to generate machine learning (ML)-based predictive models that incorporate individual predictorsof overall survival (OS) for patients with AML, based on clinical events occurring after the initiation of ven/aza or 7+3 regimen.Methods: Data from 221 patients with AML, who received either the ven/aza (n=101 patients) or 7+3 regimen (n=120 patients)as their initial induction therapy, were retrospectively analyzed. We performed stratified univariate and multivariate analyses toquantify the association between toxicities, hospital events, and short-term disease responses and OS for the 7+3 and ven/azasubgroups separately. We compared the estimates of confounders to assess potential effect modifications by treatment. 17ML-based predictive models were developed. The optimal predictive models were selected based on their predictability anddiscriminability using cross-validation. Uncertainty in the estimation was assessed through bootstrapping.Results: The cumulative incidence of posttreatment toxicities varies between the ven/aza and 7+3 regimen. A variety of laboratoryfeatures and clinical events during the first 30 days were differentially associated with OS for the two treatments. An initialtransfer to intensive care unit (ICU) worsened OS for 7+3 patients (aHR 1.18, 95% CI 1.10-1.28), while ICU readmission adverselyaffected OS for those on ven/aza (aHR 1.24, 95% CI 1.12-1.37). At the initial follow-up, achieving a morphologic leukemia freestate (MLFS) did not affect OS for ven/aza (aHR 0.99, 95% CI 0.94-1.05), but worsened OS following 7+3 (aHR 1.16, 95% CI1.01-1.31) compared to that of complete remission (CR). Having blasts over 5% at the initial follow-up negatively impacted OSfor both 7+3 (P<.001) and ven/aza (P<.001) treated patients. A best response of CR and CR with incomplete recovery (CRi) wassuperior to MLFS and refractory disease after ven/aza (P<.001), whereas for 7+3, CR was superior to CRi, MLFS, and refractorydisease (P<.001), indicating unequal outcomes. Treatment-specific predictive models, trained on 120 7+3 and 101 ven/aza patientsusing over 114 features, achieved survival AUCs over 0.70.Conclusions: Our findings indicate that toxicities, clinical events, and responses evolve differently in patients receiving ven/azacompared with that of 7+3 regimen. ML-based predictive models were shown to be a feasible strategy for CDS in both forms ofAML treatment. If validated with larger and more diverse data sets, these findings could offer valuable insights for developingAML-CDS tools that leverage posttreatment clinical data

Recurrent uveitis (RU) is a leading cause of ocular decrement in both humans and horses, which can lead to blindness. Equine recurrent uveitis (ERU) serves as the only spontaneous model for human RU as the eye destruction in both diseases is guided by a dysregulated cytokine milieu mediated by T lymphocytes. We have recently shown that the topical administration of a peptide (SOCS1-KIR), which mimics a natural regulator of cytokine signaling, was correlated with a reduction in clinical pathology when applied to the eye of horses with ERU. This administration was without any observed toxicity. The purpose of this study is to establish the intraocular presence of topical SOCS1-KIR treatment. As such, we administered SOCS1-KIR to the eye of experimental horses (lacking ocular pathology) to evaluate peptide localization and detection of a biological signature. SOCS1-KIR peptide, that was intravitreally-injected, was readily detectable within the retina by immunofluorescence. Although we were unable to detect topically administered SOCS1-KIR by immunofluorescence, topical administration reduced levels of TNFa and IL-10 in the aqueous humor of treated eyes. Additionally, we found that SOCS1-KIR modulated TNFa, IL-6, IL-10, RANTES, and IL-8 levels within activated healthy equine PBMC. Together these results suggest a novel biological signature that is mediated by topical SOCS1-KIR administration to the equine eye that has implications for translation to the clinical setting. This work was supported by the Grayson Jockey Club grant

Glucose metabolism in the retina is carefully orchestrated, with glucose being delivered to photoreceptors from the choroidal circulation through the retinal pigmented epithelium (RPE). In photoreceptors, glucose is processed principally by aerobic glycolysis, from which the lactate byproduct is provided to the RPE and Müller glia for their energetic needs. In this study, we utilize a modified arrestin1 protein to enhance the glycolytic output of lactate from rod photoreceptors through disinhibition of enolase1 activity with the goal being to use this increased lactate production as a gene-agnostic approach to slowing retinal degeneration. Mouse arrestin1 with E362G/D363G amino acid substitutions (referred to as “ArrGG”) was packaged into AAV and tested for safety and for efficacy in increasing retinal lactate production. Overexpression of ArrGG in C57BL/6J mice did not result in any detectable changes in either electroretinogram (ERG) function or photoreceptor survival as measured by outer nuclear layer (ONL) thickness. However, mouse retinas expressing ArrGG showed a ∼25% increase in the rate of lactate secretion. Therefore, AAV-ArrGG was delivered intravitreally to heterozygous P23H rhodopsin knockin mice (RhoP23H/+) to determine if enhancing glycolysis in photoreceptors can slow retinal degeneration in this animal model of retinitis pigmentosa. We found that the expression of ArrGG in these mice slowed the decline of both scotopic and photopic ERG function. Correspondingly, there was significant preservation of ONL thickness in RhoP23H/+ mice treated with ArrGG compared with controls. In conclusion, our studies show that expressing ArrGG in C57BL/6J mouse retina results in an increase in lactate production, consistent with an upregulation of glycolysis. In the P23H rhodopsin model of retinitis pigmentosa, the expression of ArrGG led to significant preservation of photoreceptor function and slowing of retinal degeneration. These findings suggest that enhancing glycolysis by targeting increased enolase1 activity with a modified arrestin1 in photoreceptors may offer a therapeutic approach to slowing retinal degeneration.

A pathologic feature of late-onset retinal degeneration caused by the S163R mutation in C1q-tumor necrosis factor-5 (C1QTNF5) is the presence of unusually thick deposits between the retinal pigmented epithelium (RPE) and the vascular choroid, considered a hallmark of this disease. Following its specific expression in mouse RPE, the S163R mutant exhibits a reversed polarized distribution relative to the apically secreted wild-type C1QTNF5, and forms widespread, prominent deposits that gradually increase in size with aging. The current study shows that S163R deposits expand to a considerable thickness through a progressive increase in the basolateral RPE membrane, substantially raising the total RPE height, and enabling their clear imaging as a distinct hyporeflective layer by noninvasive optical coherence tomography in advanced age animals. This phenotype bears a striking resemblance to ocular pathology previously documented in patients harboring the S163R mutation. Therefore, a similar viral vector-based gene delivery approach was used to also investigate the behavior of P188T and G216C, two novel pathogenic C1QTNF5 mutants recently reported in patients for which histopathologic data are lacking. Both mutants primarily impacted the RPE/photoreceptor interface and did not generate basal laminar deposits. Distinct distribution patterns and phenotypic consequences of C1QTNF5 mutants were observed in vivo, which suggested that multiple pathobiological mechanisms contribute to RPE dysfunction and vision loss in this disorder.

Mutations in RHO, the gene for rhodopsin, account for a large fraction of autosomal-dominant retinitis pigmentosa (adRP). Patients fall into two clinical classes, those with early onset, pan retinal photoreceptor degeneration, and those who experience slowly progressive disease. The latter class of patients are candidates for photoreceptor-directed gene therapy, while former may be candidates for delivery of light-responsive proteins to interneurons or retinal ganglion cells. Gene therapy for RHO adRP may be targeted to the mutant gene at the DNA or RNA level, while other therapies preserve the viability of photoreceptors without addressing the underlying mutation. Correcting the RHO gene and replacing the mutant RNA show promise in animal models, while sustaining viable photoreceptors has the potential to delay the loss of central vision and may preserve photoreceptors for gene-directed treatments.

PURPOSEThere are currently limited objective criteria to help assist physicians in determining whether an individual patient with acute myeloid leukemia (AML) is likely to do better with induction with either standard 7 + 3 chemotherapy or targeted therapy with venetoclax plus azacitidine. The study goal was to address this need by developing exploratory clinical decision support methods.PATIENTS AND METHODSUnivariable and multivariable analysis as well as comparison of a range of machine learning (ML) predictors were performed using cohorts of 120 newly diagnosed 7 + 3-treated AML patients compared with 101 venetoclax plus azacitidine-treated patients.RESULTSA variety of features in the two patient cohorts were identified that may potentially correlate with short- and long-term outcomes, toxicities, and other considerations. A subset of these diagnostic features was then used to develop ML-based predictors with relatively high areas under the curve of short- and long-term outcomes, hospital stays, transfusion requirements, and toxicities for individual patients treated with either venetoclax/azacitidine or 7 + 3.CONCLUSIONPotential ML-based approaches to clinical decision support to help guide individual patients with newly diagnosed AML to either 7 + 3 or venetoclax plus azacitidine induction therapy were identified. Larger cohorts with separate test and validation studies are necessary to confirm these initial findings.

Equine recurrent uveitis (ERU) is a painful and debilitating autoimmune disease and represents the only spontaneous model of human recurrent uveitis (RU). Despite the efficacy of existing treatments, RU remains a leading cause of visual handicap in horses and humans. Cytokines, which utilize Janus kinase 2 (Jak2) for signaling, drive the inflammatory processes in ERU that promote blindness. Notably, suppressor of cytokine signaling 1 (SOCS1), which naturally limits the activation of Jak2 through binding interactions, is often deficient in autoimmune disease patients. Significantly, we previously showed that topical administration of a SOCS1 peptide mimic (SOCS1-KIR) mitigated induced rodent uveitis. In this pilot study, we test the potential to translate the therapeutic efficacy observed in experimental rodent uveitis to equine patient disease. Through bioinformatics and peptide binding assays we demonstrate putative binding of the SOCS1-KIR peptide to equine Jak2. We also show that topical, or intravitreal injection of SOCS1-KIR was well tolerated within the equine eye through physical and ophthalmic examinations. Finally, we show that topical SOCS1-KIR administration was associated with significant clinical ERU improvement. Together, these results provide a scientific rationale, and supporting experimental evidence for the therapeutic use of a SOCS1 mimetic peptide in RU.

Purpose: Ocular hypertension is a significant risk factor for vision loss in glaucoma caused by the death of retinal ganglion cells (RGCs). We investigated whether small heat shock proteins (sHsps) expressed in RGCs protect those cells against ocular hypertension in mice. Methods: AAV2 vectors encoding genes for one of the following four human sHsps: HSPB1, HSPB4, HSPB5, or HSPB6 were constructed for RGC-specific expression. Ischemia/reper fusion was induced by elevating the intraocular pressure (IOP) to 120 mm Hg for one hour, followed by a rapid return to normal IOP. Microbeads (MB) were injected into the anterior chamber of mice to induce ocular hypertension. RGC death and glial activation were assessed by immunostaining for Brn3a, RBPMS, Iba1, and glial fibrillary acid protein in retinal flat mounts. RGC axonal defects were evaluated by anterograde transport of intravitreally injected cholera toxin-B. RGC function was assessed by pattern electroretinography. Results: Among the sHsps, HspB1 offered the best protection against RGC death from ischemia/reper fusion injury in the mouse retina. Intravitreal administration of AAV2-HSPB1 either two weeks before or one week after instituting ocular hyperten-sion resulted in significant prevention of RGC loss. The MB-injected mice showed RGC axonal transportation defects, but AAV2-HSPB1 administration significantly inhibited this defect. AAV2-HSPB1 prevented glial activation caused by ocular hypertension. More importantly, a single injection of AAV2-HSPB1 protected RGCs long-term in MB-injected eyes. Conclusions: The administration of AAV2-HSPB1 inhibited RGC death and axonal trans-port defects and reduced glial activation in a mouse model of ocular hypertension. Translational Relevance: Our results suggested that the intravitreal delivery of AAV2-HSPB1 could be developed as a gene therapy to prevent vision loss on a long-term basis in glaucoma patients.

Glaucoma is the leading cause of irreversible blindness worldwide. Therapies for glaucoma are directed toward reducing intraocular pressure (IOP), the leading risk factor and only reliable therapeutic target via topical medications or with procedural intervention including laser or surgery. Though topical therapeutics are typically first line, less than 50% of patients take drops as prescribed. Sustained release technologies that decrease IOP for extended periods of time are being examined for clinical use. We recently identified Stanniocalcin-1, a naturally occurring hormone, as an IOP-lowering agent. Here, we show that a single injection into the anterior chamber of mice with an adeno-associated viral vector containing the transgene of stanniocalcin-1 results in diffuse and sustained expression of the protein and produces IOP reduction for up to 6 months. As the treatment effect begins to wane, IOP-lowering can be rescued with a repeat injection. Aqueous humor dynamic studies revealed an increase in outflow facility as the mechanism of action. This first-in-class therapeutic approach has the potential to improve care and reduce the rates of vision loss in the 80 million people worldwide currently affected by glaucoma.

Amyloids are depositions of insoluble proteinaceous fibrils with β-sheet secondary structure. Many proteins can form amyloids, including immunoglobulin light chain (AL amyloid) and less frequently, immunoglobulin heavy chain (AH amyloid). AL amyloid deposition is typically associated with AL amyloidosis, a systemic condition often associated with multiple myeloma.1 AL amyloidosis can result in tumor-like accumulations of amyloid called “amyloidomas.” These occur rarely but are most frequent in the respiratory, urinary, and gastrointestinal tracts.

KAT6A syndrome is a Mendelian Disorder of the Epigenetic Machinery characterized by intellectual disability and profound expressive language impairment. This study aimed to further characterize behavior and sleep in this syndrome. 26 participants between the ages of 3 and 35 years with KAT6A syndrome were assessed via parental informant using the Adaptive Behavior Assessment System version 3 (ABAS-3), Achenbach Child or Adult Behavior Checklist (CBCL/ABCL), and a Modified Simonds and Parraga Sleep Questionnaire (MSPSQ). The ABAS reports conceptual, social, and practical domains of adaptive function as well as a general composite score for adaptive function. The CBCL/ABCL is an inventory that measures internalizing, externalizing, and DSM-oriented problem domains. The MSPSQ is a mix of qualitative and quantitative sleep information that includes behavioral and medical sleep problems. Mean values for all domains of the ABAS-3 were in the extremely low range. Additionally, sleep was very dysfunctional in this cohort. Sixty percent of respondents reported feeling there was a sleep problem, 64% take medication for sleep, and 68% have sought treatment or advice for sleep. Only 12% of these participants have sleep apnea suggesting that sleep problems in this disorder are unrelated to sleep-disordered breathing. Interestingly, there were extremely low rates of all types of behaviors reported among participants on the CBCL/ABCL. No significant differences were seen based on genotype grouping in adaptive function, sleep, or behavior. This study further delineates the phenotype of the KAT6A syndrome and emphasizes the need for supports for adaptive functioning as well as detailed attention to the behavioral aspects of sleep in this condition.