Humans and other mammalian hosts have evolved mechanisms to control the bacteria colonizing their mucosal barriers to prevent invasion. While the breach of barriers by bacteria typically leads to overt infection, increasing evidence supports a role for translocation of commensal bacteria across an impaired gut barrier to extraintestinal sites in the pathogenesis of autoimmune and other chronic, non-infectious diseases. Whether gut commensal translocation is a cause or consequence of the disease is incompletely defined. Here we discuss factors that lead to translocation of live bacteria across the gut barrier. We expand upon our recently published demonstration that translocation of the gut pathobiont can induce autoimmunity in susceptible hosts and postulate on the role of species as instigators of chronic, non-infectious diseases.
The mucosal glycocalyx of the ocular surface constitutes the point of interaction between the tear film and the apical epithelial cells. Membrane-associated mucins (MAMs) are the defining molecules of the glycocalyx in all mucosal epithelia. Long recognized for their biophysical properties of hydration, lubrication, anti-adhesion and repulsion, MAMs maintain the wet ocular surface, lubricate the blink, stabilize the tear film and create a physical barrier to the outside world. However, it is increasingly appreciated that MAMs also function as cell surface receptors that transduce information from the outside to the inside of the cell. A number of excellent review articles have provided perspective on the field as it has progressed since 1987, when molecular cloning of the first MAM was reported. The current article provides an update for the ocular surface, placing it into the broad context of findings made in other organ systems, and including new genes, new protein functions and new biological roles. We discuss the epithelial tissue-equivalent with mucosal differentiation, the key model system making these advances possible. In addition, we make the first systematic comparison of MAMs in human and mouse, establishing the basis for using knockout mice for investigations with the complexity of an in vivo system. Lastly, we discuss findings from human genetics/genomics, which are providing clues to new MAM roles previously unimagined. Taken together, this information allows us to generate hypotheses for the next stage of investigation to expand our knowledge of MAM function in intracellular signaling and roles unique to the ocular surface.
Enterococci are unusually well adapted for survival and persistence in a variety of adverse environments, including on inanimate surfaces in the hospital environment and at sites of infection. This intrinsic ruggedness undoubtedly played a role in providing opportunities for enterococci to interact with other overtly drug-resistant microbes and acquire additional resistances on mobile elements. The rapid rise of antimicrobial resistance among hospital-adapted enterococci has rendered hospital-acquired infections a leading therapeutic challenge. With about a quarter of a genome of additional DNA conveyed by mobile elements, there are undoubtedly many more properties that have been acquired that help enterococci persist and spread in the hospital setting and cause diseases that have yet to be defined. Much remains to be learned about these ancient and rugged microbes, particularly in the area of pathogenic mechanisms involved with human diseases.
Thrombospondin 1 (TSP-1) is an extracellular matrix protein that interacts with a wide array of ligands including cell receptors, growth factors, cytokines and proteases to regulate various physiological and pathological processes. Constitutively expressed by certain ocular surface tissues (e.g. corneal and conjunctival epithelium), TSP-1 expression is modulated during ocular surface inflammation. TSP-1 is an important activator of latent TGF-β, serving to promote the immunomodulatory and wound healing functions of TGF-β. Mounting research has deepened our understanding of how TSP-1 expression (and lack thereof) contributes to ocular surface homeostasis and disease. Here, we review current knowledge of the function of TSP-1 in dry eye disease, ocular allergy, angiogenesis/lymphangiogenesis, corneal transplantation, corneal wound healing and infectious keratitis.
Pathogenic variants in the X-linked gene ZC4H2, which encodes a zinc-finger protein, cause an infrequently described syndromic form of arthrogryposis multiplex congenita (AMC) with central and peripheral nervous system involvement. We present genetic and detailed phenotypic information on 23 newly identified families and simplex cases that include 19 affected females from 18 families and 14 affected males from nine families. Of note, the 15 females with deleterious de novo ZC4H2 variants presented with phenotypes ranging from mild to severe, and their clinical features overlapped with those seen in affected males. By contrast, of the nine carrier females with inherited ZC4H2 missense variants that were deleterious in affected male relatives, four were symptomatic. We also compared clinical phenotypes with previously published cases of both sexes and provide an overview on 48 males and 57 females from 42 families. The spectrum of ZC4H2 defects comprises novel and recurrent mostly inherited missense variants in affected males, and de novo splicing, frameshift, nonsense, and partial ZC4H2 deletions in affected females. Pathogenicity of two newly identified missense variants was further supported by studies in zebrafish. We propose ZC4H2 as a good candidate for early genetic testing of males and females with a clinical suspicion of fetal hypo-/akinesia and/or (neurogenic) AMC.
The light-sensitive photoreceptors in the retina are extremely metabolically demanding and have the highest density of mitochondria of any cell in the body. Both physiological and pathological retinal vascular growth and regression are controlled by photoreceptor energy demands. It is critical to understand the energy demands of photoreceptors and fuel sources supplying them to understand neurovascular diseases. Retinas are very rich in lipids, which are continuously recycled as lipid-rich photoreceptor outer segments are shed and reformed and dietary intake of lipids modulates retinal lipid composition. Lipids (as well as glucose) are fuel substrates for photoreceptor mitochondria. Dyslipidemia contributes to the development and progression of retinal dysfunction in many eye diseases. Here, we review photoreceptor energy demands with a focus on lipid metabolism in retinal neurovascular disorders.
SUMMARY is a diverse and rugged genus colonizing the gastrointestinal tract of humans and numerous hosts across the animal kingdom. Enterococci are also a leading cause of multidrug-resistant hospital-acquired infections. In each of these settings, enterococci must contend with changing biophysical landscapes and innate immune responses in order to successfully colonize and transit between hosts. Therefore, it appears that the intrinsic durability that evolved to make enterococci optimally competitive in the host gastrointestinal tract also ideally positioned them to persist in hospitals, despite disinfection protocols, and acquire new antibiotic resistances from other microbes. Here, we discuss the molecular mechanisms and regulation employed by enterococci to tolerate diverse stressors and highlight the role of stress tolerance in the biology of this medically relevant genus.
The presentation of idiopathic intracranial hypertension (IIH) in pediatric populations has several important distinctions from that in adults, especially among prepubertal patients, in which there is no apparent association with gender or obesity. Pediatric patients are more likely to be asymptomatic or present with atypical symptoms than their adult counterparts, posing a diagnostic challenge in some cases. It is important to be aware of the ways in which diagnostic criteria for IIH are modified from that of adults. Ideal treatment practices and the natural history of pediatric IIH remain unclear. Acetazolamide is the mainstay of medical treatment, but some patients with significant visual loss may require surgical intervention. Multicenter studies to accrue a large number of cases and future prospective studies will help to better define pediatric IIH and to formulate consensus guidelines for treatment and management of these patients.
Amblyopia refers to visual impairment resulting from perturbations in visual experience during visual development, typically secondary to strabismus, uncorrected refractive error, and/or deprivation. Amblyopia has traditionally been considered a cortical disease, but the depth of our understanding of this complex neurodevelopmental condition is limited by our ability to appreciate structural pathophysiology in the visual pathway. Recent advances in Optical Coherence Tomography (OCT) have facilitated numerous studies of the structural changes in the retina and optic nerve, thereby expanding our appreciation for the pathogenesis of this condition. In this review, we summarize findings from studies evaluating retinal, retinal nerve fiber layer, and choroidal thickness changes in patients with amblyopia. Focusing on the largest and most recent studies, we discuss common limitations and confounding variables in these studies. We summarize recent advances in ocular imaging technology and reconcile the findings of early histological reports with those of structural OCT in amblyopia.
Mutationally constrained epitopes of variable pathogens represent promising targets for vaccine design but are not reliably identified by sequence conservation. In this study, we employed structure-based network analysis, which applies network theory to HIV protein structure data to quantitate the topological importance of individual amino acid residues. Mutation of residues at important network positions disproportionately impaired viral replication and occurred with high frequency in epitopes presented by protective human leukocyte antigen () class I alleles. Moreover, CD8 T cell targeting of highly networked epitopes distinguished individuals who naturally control HIV, even in the absence of protective alleles. This approach thereby provides a mechanistic basis for immune control and a means to identify CD8 T cell epitopes of topological importance for rational immunogen design, including a T cell-based HIV vaccine.
PURPOSE: To compare mycophenolate mofetil (MMF) to methotrexate (MTX) as corticosteroid-sparing therapy for ocular inflammatory diseases. DESIGN: Retrospective analysis of cohort study data. METHODS: Participants were identified from the Systemic Immunosuppressive Therapy for Eye Diseases Cohort Study. Demographic and clinical characteristics were obtained via medical record review. The study included 352 patients who were taking single-agent immunosuppression with MTX or MMF at 4 tertiary uveitis clinics. Marginal structural models (MSM)-derived statistical weighting created a virtual population with covariates and censoring patterns balanced across alternative treatments. With this methodological approach, the results estimate what would have happened had none of the patients stopped their treatment. Survival analysis with stabilized MSM-derived weights simulated a clinical trial comparing MMF vs MTX for noninfectious inflammatory eye disorders. The primary outcome was complete control of inflammation on prednisone ≤10 mg/day, sustained for ≥30 days. RESULTS: The time to success was shorter (more favorable) for MMF than MTX (hazard ratio = 0.68, 95% confidence interval: 0.46-0.99). Adjusting for covariates, the proportion achieving success was higher at every point in time for MMF than MTX from 2 to 8 months, then converges at 9 months. The onset of corticosteroid-sparing success took more than 3 months for most patients in both groups. Outcomes of treatment (MMF vs MTX) were similar across all anatomic sites of inflammation. The incidence of stopping therapy for toxicity was similar in both groups. CONCLUSIONS: Our results suggest that, on average, MMF may be faster than MTX in achieving corticosteroid-sparing success in ocular inflammatory diseases.
PURPOSE: To present the process of cultural and psychometric adaptation, and clinical validation of a new version in the Spanish language of the Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8). MATERIALS AND METHODS: The translation-retro-translation method was applied to the CLDEQ-8 questionnaire. Two independent native Spanish-speaking translators adapted the questionnaire from English to Spanish, and then a committee of experienced clinicians (CE) evaluated the semantic equivalence and designed a Spanish version of the CLDEQ-8 questionnaire. The resulting translated version was tested conducting a pilot study in contact lens users and assessing their perception and overall understanding of the terminology. The results were analyzed and a final version was designed. The final version was retro-translated to English by a native English-speaking translator and compared with the original CLDEQ-8 version to confirm there were no meaningful differences. To clinically validate the new instrument, a prospective study was conducted to apply the new Spanish CLDEQ-8 to 50 contact lens users. RESULTS: Fifty patients were studied with an average age of 21.50 ± 1.66 years. The average CLDEQ-8 score was 13.28 ± 6.81 points (range 1-31). The internal consistency (Cronbach's alpha) was 0.89, with a corrected index of homogeneity >0.50 for all evaluated items. CONCLUSIONS: The process of trans-cultural adaptation of the questionnaire CLDEQ-8 resulted in the elaboration of a reliable and much needed instrument capable of measuring frequency and intensity of dry eye symptoms in Spanish-speaking contact lens users.
The presence of optic nerve swelling in pediatric patients is a frequent cause for referral to pediatric ophthalmologists and neuro-ophthalmologists because this finding can be the harbinger of serious neurologic disease including brain tumor, demyelinating disease, infiltrative disease of the optic nerve, or idiopathic intracranial hypertension. Optic nerve head drusen (ONHD) are common and can be particularly difficult to distinguish from true optic nerve swelling in pediatric patients because the ONHD are typically buried beneath the substance of the optic nerve. Correct identification of ONHD is relevant because of the visual morbidity associated with this condition and because of the need to distinguish pseudopapilledema secondary to ONHD from true optic nerve swelling. A variety of imaging modalities may be employed to evaluate for the presence of ONHD, including ultrasound, optical coherence tomography (OCT), enhanced depth imaging-OCT, fluorescein angiography, fundus autofluorescence, and optical coherence tomography angiography. To date, there is no consensus as to which of these techniques is most accurate and which should be part of a standardized evaluation for children suspected of ONHD. This review examines the recent literature analyzing these diagnostic tools and summarizes data regarding best practices for identifying ONHD.
In vivo delivery of genome-modifying enzymes holds significant promise for therapeutic applications and functional genetic screening. Delivery to endogenous tissue stem cells, which provide an enduring source of cell replacement during homeostasis and regeneration, is of particular interest. Here, we use a sensitive Cre/lox fluorescent reporter system to test the efficiency of genome modification following in vivo transduction by adeno-associated viruses (AAVs) in tissue stem and progenitor cells. We combine immunophenotypic analyses with in vitro and in vivo assays of stem cell function to reveal effective targeting of skeletal muscle satellite cells, mesenchymal progenitors, hematopoietic stem cells, and dermal cell subsets using multiple AAV serotypes. Genome modification rates achieved through this system reached >60%, and modified cells retained key functional properties. This study establishes a powerful platform to genetically alter tissue progenitors within their physiological niche while preserving their native stem cell properties and regulatory interactions.
Purpose: Allergic rhinitis (AR) affects ~20% of the population worldwide. The objectives of this study were to evaluate the safety and efficacy of iodixanol nasal solution (Nasapaque) for AR treatment, using the Allergen BioCube (ABC), an environmental exposure unit. Iodixanol is a commonly used contrast media agent that shows efficacy on the signs and symptoms of AR. Patients and methods: Seventy-three adult subjects with AR were randomized to iodixanol or placebo treatment in a double-masked efficacy and safety study conducted outside of ragweed pollen season. In-office treatment was administered after BioCube ragweed pollen exposure, and again 8 days later prior to ragweed exposure. Nasal and ocular efficacy and safety assessments were conducted before and after treatment. Results: Iodixanol treatment resulted in statistically significantly lower total nasal symptom scores as compared to placebo at several time points post-treatment and ABC exposure. Individual nasal and ocular symptoms, notably nasal itching and ocular itching, showed evidence of lower scores in the iodixanol group. Peak nasal inspiratory flow (PNIF) improved (9%-16%) with iodixanol from baseline as compared to PNIF in the placebo group which ranged from 3% worsening to improvement of 2%. Few (9) adverse events occurred. Conclusion: Iodixanol nasal solution demonstrated efficacy for relief of several nasal and ocular allergic rhinoconjunctivitis signs and symptoms, and was safe and well tolerated in this early Phase II exploratory trial. Further studies with iodixanol are warranted. Allergy challenge models such as the ABC provide valuable assessments of allergen exposures and drug efficacies. Study Identification Number: NCT02377895.
Neutrophil-mediated inflammation plays a critical role in corneal damage following injury or infection. Previous studies demonstrated that membrane-bound FasL (mFasL) induces neutrophil chemokine production. However, the extracellular domain of mFasL is normally cleaved by matrix metalloproteinases to release a soluble form of FasL (sFasL) and sFasL antagonizes mFasL-mediated chemokine production. Therefore, we hypothesized that sFasL could be used to prevent neutrophil-mediated corneal inflammation associated with injury and bacterial keratitis. To test this hypothesis, GFP-only, sFasL-GFP, or mFasL-GFP were expressed in the corneal stroma of C57BL/6 mice, using intra-stromal injections of plasmid DNA or adenoviral vectors (AV) and the role of mFasL and sFasL in corneal inflammation was examined in models of corneal injury and LPS-induced keratitis. Our work addresses an important area of disagreement in the field of FasL, with regard to the mechanism by which sFasL regulates ocular inflammation. Herein, we demonstrate that an intrastromal injection of GFP-only, sFasL-GFP, or mFasL-GFP plasmid DNA resulted in GFP expression throughout the corneal stroma for up to two weeks with little to no evidence of inflammation in the GFP-only and sFasL-GFP groups and mild corneal inflammation in the mFasL-GFP group. Similarly, following epithelial debridement, corneas expressing GFP-only or sFasL-GFP showed no significant signs of corneal inflammation, with clear corneas at 15 days post debridement. By contrast, epithelial debridement of corneas expressing mFasL-GFP triggered persistent corneal inflammation and the development of central corneal opacities that was blocked by sFasL. Similar to the mFasL-GFP plasmid DNA, intrastromal injection of mFasL-GFP AV triggered mild corneal inflammation, but it was transient and resolved by day 10 with corneas remaining clear out to 30 days post injection. Nevertheless, intrastromal expression of mFasL-GFP AV exacerbated LPS-induced keratitis, corneal opacity, and neovascularization, while sFasL-GFP AV expression prevented LPS-induced keratitis, resulting in a clear cornea. Histological analysis of corneas with LPS-induced keratitis revealed a robust infiltration of macrophages and neutrophils and sFasL expression specifically blocked the neutrophil influx. Overall, our data demonstrate that stromal expression of mFasL is inflammatory, while sFasL is non-inflammatory, and opposes the effects of mFasL in mouse models of epithelial debridement and LPS-induced keratitis. These data demonstrate that a delicate balance between sFasL and mFasL regulates ocular inflammation. This study further identifies sFasL as a potent inhibitor of neutrophil-mediated corneal damage, and supports the potential use of sFasL in the treatment of neutrophil-mediated keratitis. These results strongly support the hypothesis that, in the immune privileged environment of the eye, the isoform of FasL regulates immune privilege and determines the extent of inflammation: mFasL promotes inflammation and sFasL blocks inflammation.
A 53-year-old male presented with a bony lesion over the superior orbital rim increasing in size over several months. CT imaging showed a circumscribed, osseous lesion involving the outer table of the right frontal bone and superior orbital rim with a honeycomb appearance. Anterior orbitotomy revealed an osseous lesion along the superior orbital rim with purple cavernous spaces. Histopathological examination demonstrated cavernous vascular channels with variably-sized lumens and variably-thickened vascular walls interspersed among bony trabeculae consistent with an osseous cavernous hemangioma.
AIM: To systematically review whether the increased fluctuation of intraocular pressure (IOP) is a risk factor for open angle glaucoma (OAG) progression. METHODS: Scientific studies relevant to IOP fluctuation and glaucoma progression were retrieved from MEDLINE, EMBASE and CENTRAL databases, and were listed as references in this paper. The hazard ratio (HR) was calculated by using fixed or random-effects models according to the heterogeneity of included studies. RESULTS: Individual data for 2211 eyes of 2637 OAG patients in fourteen prospective studies were included in this Meta-analysis. All studies were longitudinal clinical studies with follow-up period ranging from 3 to 8.5y. The combined HR was 1.23 (95%CI 1.04-1.46, =0.02) for the association between IOP fluctuation and glaucoma onset or progression with the evidence of heterogeneity (<0.1). Subgroup analyses with different types of IOP fluctuation were also evaluated. Results indicated that the summary HR was 0.98 (95%CI 0.78-1.24) in short-term IOP fluctuation group, which showed no statistical significance with heterogeneity, whereas, the combined HR was 1.43 (95%CI 1.13-1.82, =0.003) in long-term IOP fluctuation group without homogeneity. Sensitivity analysis further showed that the pooled HR was 1.10 (95%CI 1.03-1.18, =0.004) for long-term IOP fluctuation and visual function progression with homogeneity among studies (=0.3). CONCLUSION: Long-term IOP fluctuation can be a risk factor for glaucoma progression based on the presented evidence. Thus, controlling the swing of IOP is crucial for glaucoma or glaucoma suspecting patients.
PURPOSE: To evaluate microstructural retinal abnormalities on spectral domain optical coherence tomography (SD-OCT) imaging of eyes with Coats disease. METHODS: This is a multicenter, retrospective study in which SD-OCT images of patients with treatment-naive Coats disease were correlated with clinical examination and visual acuity and, when available, followed longitudinally over time. RESULTS: Macular SD-OCT of 27 eyes with Coats disease revealed intraretinal edema (59%), intraretinal exudates (67%), subretinal fluid (37%), subretinal exudate (48%), ellipsoid zone disruption (52%), external limiting membrane disruption (41%), and subfoveal nodule (26%). All these microstructural abnormalities correlated with worse baseline and final visual acuities (P < 0.05) on univariate analysis, except for intraretinal edema which exhibited a nonstatistically significant trend toward worse baseline visual acuity (P = 0.16). Within stage 2b eyes, external limiting membrane disruption and subretinal nodule on SD-OCT were associated with worse baseline visual acuity (P = 0.02 for both), and there was a trend toward worse final visual acuity with external limiting membrane disruption and subretinal nodule (P = 0.17 for both) and worse baseline (P = 0.08) and final (P = 0.13) visual acuities with ellipsoid zone disruption. No microstructural abnormalities were noted on OCT of fellow eyes. CONCLUSION: Spectral domain OCT can identify microstructural abnormalities in Coats disease that are associated on univariate analysis with worse baseline visual acuity and visual prognosis. Further larger studies are necessary.