Uveitis-mediated immune cell invasion through the extracellular matrix of the lens capsule

Immunoregulatory Properties of Immune Cells that Associate with the Lens Capsule Surface during Acute and Resolution Phases of Experimental Autoimmune Uveitis

Inflammation in the eye is tightly regulated to prevent vision impairment and irreversible blindness. Emerging evidence shows that immune cells are specifically recruited to the lens capsule in response to autoimmune uveitis, yet the potential that they have a role in regulating this inflammatory disease remained unexplored. Here, using an immunolocalization approach combined with high-resolution confocal microscopy, we investigated whether the immune cells that become stably associated with the lens capsule in the eyes of C57BL/6J mice with experimental autoimmune uveitis (EAU) have an immunoregulatory phenotype. These studies revealed that during the acute phase of uveitis, at day 18 after disease induction, the immune cells specifically recruited to the lens capsule included those with putative anti-inflammatory, proresolution roles, such as regulatory T cells (FoxP3+CD4+) and M2 macrophages (CD68+ arginase 1+IL-10+). The frequency of these lens capsule-associated immunomodulatory phenotypes increased at day 35 after induction, during the resolution phase of EAU inflammation. At this later stage of resolution, most of the macrophages expressed CD206, a mannose receptor responsible for removing inflammatory molecules, in addition to arginase 1 and IL-10. Our results suggest a previously unknown role for the lens as a site for recruitment of immune cells whose role is to suppress inflammation, promote resolution, and maintain remission of EAU.

Associations of severe liver diseases with cataract using data from UK Biobank: a prospective cohort study

Background

Liver disease is linked to series of extrahepatic multisystem manifestations. However, little is known about the associations between liver and eye diseases, especially cataract, the global leading cause of blindness. We aimed to investigate whether severe liver diseases, including non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), viral hepatitis, and liver fibrosis and cirrhosis, were associated with an increased risk of the cataract.

Methods

A total of 326,558 participants without cataract at baseline enrolled in the UK Biobank between 2006 and 2010 were included in this prospective study. The exposures of interest were severe liver diseases (defined as hospital admission), including NAFLD, ALD, viral hepatitis and liver fibrosis and cirrhosis. The outcome was incident cataract. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs). Each liver disease was first treated as a binary time-varying variable to investigate its association with cataract, and then was treated as a ternary time-varying variable to examine the recent (liver disease within 0-5 years) vs. long-term (liver disease > 5 years) state associations with the risk of cataract.

Findings

After a median follow-up of 13.3 years (interquartile range, 12.5-14.0 years), 37,064 individuals were documented as developing cataract. Higher risk of cataract was found in those with severe NAFLD (HR, 1.47; 95% CI, 1.33-1.61), ALD (HR, 1.57; 95% CI, 1.28-1.94) and liver fibrosis and cirrhosis (HR, 1.58; 95% CI, 1.35-1.85), but not in individuals with viral hepatitis when exposure was treated as a binary time-varying variable (P = 0.13). When treating exposure as a ternary time-varying variable, an association between recently diagnosed viral hepatitis and cataract was also observed (HR, 1.55; 95% CI, 1.07-2.23). Results from the combined model suggested they were independent risk factors for incident cataract. No substantial changes were found in further sensitivity analyses.

Interpretation

Severe liver diseases, including NAFLD, ALD, liver fibrosis and cirrhosis and recently diagnosed viral hepatitis, were associated with cataract. The revelation of liver-eye connection suggests the importance of ophthalmic care in the management of liver disease, and the intervention precedence of patients with liver disease in the early screening and diagnosis of cataract.

Funding

National Natural Science Foundation of China, Science and Technology Innovation Action Plan of Shanghai Science and Technology Commission, Clinical Research Plan of Shanghai Shenkang Hospital Development Center, Shanghai Municipal Key Clinical Specialty Program, the Guangdong Basic and Applied Basic Research Foundation and Shenzhen Science and Technology Program.

Translational regulation of cell invasion through extracellular matrix-an emerging role for ribosomes

Many developmental and physiological processes require cells to invade and migrate through extracellular matrix barriers. This specialized cellular behavior is also misregulated in many diseases, such as immune disorders and cancer. Cell invasive activity is driven by pro-invasive transcriptional networks that activate the expression of genes encoding numerous different proteins that expand and regulate the cytoskeleton, endomembrane system, cell adhesion, signaling pathways, and metabolic networks. While detailed mechanistic studies have uncovered crucial insights into pro-invasive transcriptional networks and the distinct cell biological attributes of invasive cells, less is known about how invasive cells modulate mRNA translation to meet the robust, dynamic, and unique protein production needs of cell invasion. In this review we outline known modes of translation regulation promoting cell invasion and focus on recent studies revealing elegant mechanisms that expand ribosome biogenesis within invasive cells to meet the increased protein production requirements to invade and migrate through extracellular matrix barriers.

Immune Responses Induced at One Hour Post Cataract Surgery Wounding of the Chick Lens

While the lens is an avascular tissue with an immune-privileged status, studies have now revealed that there are immune responses specifically linked to the lens. The response to lens injury, such as following cataract surgery, has been shown to involve the activation of the resident immune cell population of the lens and the induction of immunomodulatory factors by the wounded epithelium. However, there has been limited investigation into the immediate response of the lens to wounding, particularly those induced factors that are intrinsic to the lens and its associated resident immune cells. Using an established chick embryo ex vivo cataract surgery model has made it possible to determine the early immune responses of this tissue to injury, including its resident immune cells, through a transcriptome analysis. RNA-seq studies were performed to determine the gene expression profile at 1 h post wounding compared to time 0. The results provided evidence that, as occurs in other tissues, the resident immune cells of the lens rapidly acquired a molecular signature consistent with their activation. These studies also identified the expression of many inflammatory factors by the injured lens that are associated with both the induction and regulation of the immune response.

Immune Cells Localize to Sites of Corneal Erosions in C57BL/6 Mice

Recurrent epithelial erosions develop in the cornea due to prior injury or genetic predisposition. Studies of recurrent erosions in animal models allow us to gain insight into how erosions form and are resolved. While slowing corneal epithelial cell migration and reducing their proliferation following treatment with mitomycin C reduce erosion formation in mice after sterile debridement injury, additional factors have been identified related to cytokine expression and immune cell activation. The relationship between recruitment of immune cells to the region of the cornea where erosions form and their potential roles in erosion formation and/or erosion repair remains unexplored in the C57BL/6 mouse recurrent erosion model. Here, high resolution imaging of mouse corneas was performed at D1, D7, and D28 after dulled-blade debridement injury in C57BL/6 mice. Around 50% of these mice have frank corneal erosions at D28 after wounding. A detailed assessment of corneas revealed the involvement of M2 macrophages in both frank and developing erosions at early stages of their formation.