Background Central serous chorioretinopathy (CSCR) is a potentially blinding choroidal disease. Despite decades of research, the pathological mechanisms of CSCR are still poorly understood. In recent years, there has been a strong emphasis on choroidal dysfunction as a primary cause of CSCR. Main Body The concept of the pachychoroid disease spectrum and pachychoroid-driven processes are central to current theories regarding the pathophysiological underpinnings of CSCR. Choroidal hyperpermeability and subsequent leakage of fluid seen in CSCR may be due to several causes. Among them are venous congestion, inflammation, mineralocorticoid receptor activation, systemic factors including hemodynamic changes, obstructive sleep apnea, phosphodiesterase inhibitor use, pregnancy, and genetic predispositions. Congestion of vortex veins that drain blood from the choroid may contribute to the dilation of Haller vessels and cause fluid leakage. Vortex veins exit the eye through the sclera; thus, increased scleral thickness has been proposed to be a factor in venous congestion. Asymmetric vortex vein drainage may similarly result in congestion of the local venous system. Vortex vein anastomoses may overload the venous system and form secondary to venous congestion. Recent studies suggest inflammation and mineralocorticoid activation may factor into the development of CSCR, though more research in these areas is called for. Systemic conditions and genetics may predispose individuals to develop CSCR. Conclusions By striving to understand the molecular and physiological mechanisms of this disease, we can better diagnose and treat CSCR to improve outcomes for patients.
Optical coherence tomography (OCT) imaging has played a pivotal role in the field of retina. This light-based, non-invasive imaging modality provides high-quality, cross-sectional analysis of the retina and has revolutionized the diagnosis and management of retinal and choroidal diseases. Since its introduction in the early 1990s, OCT technology has continued to advance to provide quicker acquisition times and higher resolution. In this manuscript, we discuss some of the most recent advances in OCT technology and techniques for choroidal and retinal diseases. The emerging innovations discussed include wide-field OCT, adaptive optics OCT, polarization sensitive OCT, full-field OCT, hand-held OCT, intraoperative OCT, at-home OCT, and more. The applications of these rising OCT systems and techniques will allow for a closer monitoring of chorioretinal diseases and treatment response, more robust analysis in basic science research, and further insights into surgical management. In addition, these innovations to optimize visualization of the choroid and retina offer a promising future for advancing our understanding of the pathophysiology of chorioretinal diseases.
Background & Aims Nonalcoholic fatty liver disease is a frequent cause of hepatic dysfunction and is now a global epidemic. This ailment can progress to an advanced form called nonalcoholic steatohepatitis (NASH) and end-stage liver disease. Currently, the molecular basis of NASH pathogenesis is poorly understood, and no effective therapies exist to treat NASH. These shortcomings are due to the paucity of experimental NASH models directly relevant to humans. Methods We used chimeric mice with humanized liver to investigate nonalcoholic fatty liver disease in a relevant model. We carried out histologic, biochemical, and molecular approaches including RNA-Seq. For comparison, we used side-by-side human NASH samples. Results Herein, we describe a “humanized” model of NASH using transplantation of human hepatocytes into fumarylacetoacetate hydrolase-deficient mice. Once fed a high-fat diet, these mice develop NAFLD faithfully, recapitulating human NASH at the histologic, cellular, biochemical, and molecular levels. Our RNA-Seq analyses uncovered that a variety of important signaling pathways that govern liver homeostasis are profoundly deregulated in both humanized and human NASH livers. Notably, we made the novel discovery that hepatocyte growth factor (HGF) function is compromised in human and humanized NASH at several levels including a significant increase in the expression of the HGF antagonists known as NK1/NK2 and marked decrease in HGF activator. Based on these observations, we generated a potent, human-specific, and stable agonist of human MET that we have named META4 (Metaphor) and used it in the humanized NASH model to restore HGF function. Conclusions Our studies revealed that the humanized NASH model recapitulates human NASH and uncovered that HGF-MET function is impaired in this disease. We show that restoring HGF-MET function by META4 therapy ameliorates NASH and reinstates normal liver function in the humanized NASH model. Our results show that the HGF-MET signaling pathway is a dominant regulator of hepatic homeostasis.
Purpose The aim of this study was to determine whether a patient navigator program can address patient-reported barriers to eye care and to understand patient perceptions of a patient navigator program in ophthalmology. Design This is a retrospective cohort study and cross-sectional patient survey. Subjects and Methods A cohort of patients was recruited from a single academic ophthalmology department in the Mid-Atlantic region. Patients included in the study had received referral to the patient navigator program in the first quarter of 2022. Our patient navigator program provided patients with resources to address barriers to care such as transportation and financial assistance. Outcomes of the study included indications for referral, case resolution rate, and patient satisfaction. Results In total, 130 referrals for 125 adult patients were included. The mean ± standard deviation age was 59 ± 17 years, 54 (44%) were male, 77 were white (62%), and 17 patients (14%) were uninsured. Common reasons for referral were transportation (52, 40%), insurance (34, 26%), and financial assistance (18, 14%). Among the 130 cases referred, 127 (98%) received an intervention from the patient navigator, who was able to resolve the referring issue in 90% of cases (117/130). Among 113 patients contacted for a follow-up telephone survey, 56 (50%) responded. Patients rated the program highly at a mean Likert rating of 4.87 out of 5. Moreover, 72% (31/43) of respondents stated their interactions with the patient navigator assisted them with taking care of their eyes. Conclusions A patient navigator program can address barriers to eye care by connecting patients with community resources.
Demise of the retinal pigment epithelium (RPE) caused by etiologies such as age‐related macular degeneration is a major underlying factor leading to vision loss. Cell death can occur through two major pathways: apoptosis and necrosis/necroptosis. In the former, Fas/FasL death receptor signaling induces apoptosis, but its role in human RPE cell death is not thoroughly elucidated. In the latter, reactive oxygen species (ROS) can induce necrosis/necroptosis. Additionally, Hepatocyte Growth Factor (HGF) is a potent growth and survival factor for epithelial cells, but its functional role in RPE is not well characterized, especially its ability to protect RPE cells from death and to induce their growth. Accordingly, we hypothesized that HGF/Met protects human RPE cells from Fas‐promoted apoptosis and H2O2‐induced necrosis/necroptosis. We analyzed whether the HGF receptor (Met) is expressed in human and non‐human primate (NHP) eye tissue via western blot analysis and immunohistochemistry. To determine whether HGF/Met protects RPE cells against death induced by Fas/FasL and H2O2, we utilized gain‐ and loss‐of‐function models, cell survival assays and gene expression analysis (RNAseq). Human ARPE‐19 cell line was treated with various combinations of HGF, Met kinase inhibitor SU11274 (SU), FasL or H2O2. Cell growth and survival was determined via MTT assay. Met, Akt, and Erk activation were analyzed by western blot. Western blot analysis and immunohistochemistry confirmed Met activity and signaling in human and NHP eye tissue, including in the RPE cell layer. We found that HGF elicited Met stimulation and signaling culminating in activation of its downstream effectors Akt and Erk, proteins involved in two major pathways controlling cell survival and proliferation. We also uncovered that HGF inhibited FasL‐ and ROS‐induced killing of RPE. Conversely, inhibiting Met signaling rendered RPE susceptible to cell death induced by FasL and H2O2. Global gene expression analysis using an RNAseq approach revealed that HGF controls expression of numerous genes governing RPE cell growth, metabolism, and survival to name a few. In particular, HGF significantly upregulated 400 and repressed expression of 420 genes six hours post‐treatment; at 24 hours post‐treatment, HGF upregulated 291 and downregulated expression of 260 genes. Expression of 11,000 genes was unchanged. Our studies establish that HGF and Met play a major role in promoting the survival and homeostasis of RPE cells by inhibiting two major pathways of RPE cell death. Our findings suggest HGF/Met is a potential druggable target for therapeutic management of RPE‐related human ocular diseases.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.