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Significance Age-related macular degeneration (AMD) affects approximately one-third of Americans over 70 and is characterized by lipoprotein-rich sub-retinal pigmented epithelium (sub-RPE) deposits. Substantial evidence has emerged that implicates complement factor H (CFH) in the pathogenesis of AMD. Here, we conduct an in vivo analysis to elucidate the role of CFH in AMD pathology. We show that ( i ) CFH and lipoproteins compete for binding in the sub-RPE extracellular matrix such that decreasing CFH leads to lipoprotein accumulation and sub-RPE deposit formation; and ( ii ) detrimental complement activation within sub-RPE deposits leads to RPE damage and vision loss. This new understanding of the complicated interactions of CFH in development of AMD-like pathology paves the way for identifying more targeted therapeutic strategies for AMD. Complement factor H (CFH) is a major susceptibility gene for age-related macular degeneration (AMD); however, its impact on AMD pathobiology is unresolved. Here, the role of CFH in the development of AMD pathology in vivo was interrogated by analyzing aged Cfh ⁺/⁻ and Cfh ⁻/⁻ mice fed a high-fat, cholesterol-enriched diet. Strikingly, decreased levels of CFH led to increased sub-retinal pigmented epithelium (sub-RPE) deposit formation, specifically basal laminar deposits, following high-fat diet. Mechanistically, our data show that deposits are due to CFH competition for lipoprotein binding sites in Bruch’s membrane. Interestingly and despite sub-RPE deposit formation occurring in both Cfh ⁺/⁻ and Cfh ⁻/⁻ mice, RPE damage accompanied by loss of vision occurred only in old Cfh ⁺/⁻ mice. We demonstrate that such pathology is a function of excess complement activation in Cfh ⁺/⁻ mice versus complement deficiency in Cfh ⁻/⁻ animals. Due to the CFH-dependent increase in sub-RPE deposit height, we interrogated the potential of CFH as a previously unidentified regulator of Bruch’s membrane lipoprotein binding and show, using human Bruch’s membrane explants, that CFH removes endogenous human lipoproteins in aged donors. Thus, advanced age, high-fat diet, and decreased CFH induce sub-RPE deposit formation leading to complement activation, which contributes to RPE damage and visual function impairment. This new understanding of the complicated interactions of CFH in AMD-like pathology provides an improved foundation for the development of targeted therapies for AMD.

We report a novel case of severe bilateral panuveitis with hypopyon secondary to rifabutin and cobicistat drug interaction in the setting of human immunodeficiency virus (HIV) infection and latent tuberculosis (TB). A 63-year-old woman presented with bilateral conjunctival injection and decreasing vision of 5 days’ duration. She had a history of well-controlled HIV infection, latent TB, and non-alcoholic steatohepatitis for which she was inadvertently being treated, due to a pharmacy error, concurrently with the anti-TB medicine rifabutin and the highly active antiretroviral therapy combination Genvoya® (elvitegravir 150 mg – cobicistat 150 mg – emtricitabine 200 mg – tenofovir alafenamide 10 mg). Ocular examination was significant for bilateral panuveitis with hypopyon. Blood, cerebrospinal fluid, and vitreous analysis were negative for infectious or rheumatologic abnormalities. Rifabutin was discontinued and the patient was treated with intravenous followed by oral steroids as an outpatient with eventual resolution of symptoms. This unique case of rifabutin-cobicistat drug interaction highlights the association between rifabutin drug levels and ocular inflammation and expands the potential presentation of rifabutin-associated uveitis to include bilateral panuveitis with hypopyon.

Decay accelerating factor (DAF) plays a complex role in the immune system through complement-dependent and -independent regulation of innate and adaptive immunity. Over the past five years there has been accumulating evidence for a significant role of DAF in negatively regulating adaptive T-cell responses and autoimmunity in both humans and experimental models. This review discusses the relationship between DAF and the complement system and highlights major advances in our understanding of the biology of DAF in human disease, particularly systemic lupus erythematosus. The role of DAF in regulation of idiopathic and environmentally induced systemic autoimmunity is discussed including studies showing that reduction or absence of DAF is associated with autoimmunity. In contrast, DAF-mediated T cell activation leads to cytokine expression consistent with T regulatory cells. This is supported by studies showing that interaction between DAF and its molecular partner, CD97, modifies expression of autoimmunity promoting cytokines. These observations are used to develop a hypothetical model to explain how DAF expression may impact T cell differentiation via interaction with CD97 leading to T regulatory cells, increased production of IL-10, and immune tolerance.

Intraocular coccidioidomycosis is a rare condition, with the most commonly reported presentation being an idiopathic iritis in patients who live in or have traveled thorough endemic areas. A paucity of reports exists describing the chorioretinal manifestations of coccidioidomycosis. Here we report a case of unilateral coccidioidal chorioretinitis and meningoencephalitis in an AIDS patient that led to near complete unilateral loss of vision. A 48-year-old Hispanic female with poorly controlled HIV/AIDS in southern California presented with a three-week history of headache, nausea, vomiting, right eye blurry vision, and a one-day history of subjective fever. Examination of the right eye revealed vitritis and several large chorioretinal lesions scattered throughout the periphery and macula with optic disc pallor. Serum coccidioidomycoses complement fixation (CF) was positive (titers of 1 : 256). Neuroimaging revealed a new area of enhancement in the left anterior frontal lobe consistent with meningoencephalitis. The patient was treated with intravenous fluconazole and intravitreal voriconazole with resolution of systemic symptoms and vitritis but persistence of unilateral, severe chorioretinal scarring and vision loss. In conclusion, in spite of the rarity of intraocular coccidioidomycosis, one must carry a degree of suspicion for this vision- and life-threatening condition as a potential etiology of chorioretinitis in individuals with pertinent risk factors.

Little is known about sialic acids of the human retina, despite their integral role in self/non-self-discrimination by complement factor H (CFH), the alternative complement pathway inhibitor. A custom sialoglycan microarray was used to characterize the sialic acid-binding specificity of native CFH or recombinant molecules where IgG Fc was fused to CFH domains 16-20 (contains a sialic acid-binding site), domains 6-7 (contains a glycosaminoglycan-binding site) or the CFH-related proteins (CFHRs) 1 and 3. We analyzed macular and peripheral retinal tissue from post-mortem ocular globes for amount, type, and presentation (glycosidic linkage type) of sialic acid in individuals with age-related macular degeneration (AMD) and age-matched controls using fluorescent lectins and antibodies to detect sialic acid and endogenous CFH. Released sialic acids from neural retina, retinal pigmented epithelium (RPE) cells and the Bruch's membrane (BrM) were labelled with 1,2-diamino-4,5-methylenedioxybenzene-2HCl (DMB), separated and quantified by high-performance liquid chromatography (DMB-HPLC). Both native CFH and the recombinant CFH domains 16-20 recognized Neu5Ac and Neu5Gc that is α2-3-linked to the underlying galactose. 4- -Actylation of sialic acid and sulfation of GlcNAc did not inhibit binding. Different linkage types of sialic acid were localized at different layers of the retina. The greatest density of α2-3-sialic acid, which is the preferred ligand of CFH, did not colocalize with endogenous CFH. The level of sialic acids at the BrM/choroid interface of macula and peripheral retina of individuals with AMD were significantly reduced. The sialome of the human retina is altered in AMD. This can affect CFH binding and consequently, alternative complement pathway regulation.

Regenerative therapies for retinal diseases include cell and gene therapy modalities that are targeted to the subretinal space. Several recent clinical trials have shown that the morbidity of surgical access is the major limitation of safe subretinal space delivery. We aimed to develop an image-guided procedure for minimally invasive subretinal access (MISA) as a platform to deliver therapeutic agents for the treatment of degenerative retinal diseases. We engineered prototypes of a novel common-path swept source optical coherence tomography (CP-SSOCT)-enabled needle, coaxial guide (COG), and subretinal access cannula (SAC). We pilot tested the MISA procedure in bovine eyes and porcine ocular surgery. A- and M-mode scan recordings of and animal eye models demonstrated that CP-SSOCT imaging from the scleral side ( ) was capable of identifying the retinal laminae and the sub-retinal space. We show results from porcine MISA surgeries (N=4) using the novel CP-SSOCT-enabled sub-retinal injection needle, COG, and SAC through the transscleral approach. The MISA approach enabled subretinal device placement in the posterior pole, however, cases of retinal incarceration and retinal perforation were encountered. We describe a novel CP-SSOCT-guided subretinal access approach that, with further optimization, may be useful in regenerative retinal surgery.

Complement factor H (CFH) is a major susceptibility gene for age-related macular degeneration (AMD); however, its impact on AMD pathobiology is unresolved. Here, the role of CFH in the development of AMD pathology in vivo was interrogated by analyzing aged Cfh+/- and Cfh-/- mice fed a high fat, cholesterol-enriched diet. Strikingly, decreased levels of CFH led to increased sub-retinal pigmented epithelium (RPE) deposit formation, specifically basal laminar deposits, following high fat diet. Mechanistically, our data show that deposits are due to CFH competition for lipoprotein binding sites in Bruch’s membrane. Interestingly and despite sub-RPE deposit formation occurring in both Cfh+/- and Cfh-/- mice, RPE damage accompanied by loss of vision occurred only in old Cfh+/- mice. We demonstrate that such pathology is a function of excess complement activation and C5a production, associated with monocyte recruitment, in Cfh+/- mice versus complement deficiency in Cfh-/- animals. Due to the CFH dependent increase in sub-RPE deposit height we interrogated the potential of CFH as a novel regulator of Bruch’s membrane lipoprotein binding and show, using human Bruch’s membrane explants, that CFH removes endogenous human lipoproteins in aged donors. Interestingly, although the CFH H402 variant shows altered binding to BrM, this does not affect its ability to remove endogenous lipoproteins. This new understanding of the complicated interactions of CFH in AMD-like pathology provides an improved foundation for the development of targeted therapies for AMD.

Color vision in birds is mediated by four types of cone photoreceptors whose maximal sensitivities (λmax) are evenly spaced across the light spectrum. In the course of avian evolution, the λmax of the most shortwave-sensitive cone, SWS1, has switched between violet (λmax > 400 nm) and ultraviolet (λmax < 380 nm) multiple times. This shift of the SWS1 opsin is accompanied by a corresponding short-wavelength shift in the spectrally adjacent SWS2 cone. Here, we show that SWS2 cone spectral tuning is mediated by modulating the ratio of two apocarotenoids, galloxanthin and 11’,12’-dihydrogalloxanthin, which act as intracellular spectral filters in this cell type. We propose an enzymatic pathway that mediates the differential production of these apocarotenoids in the avian retina, and we use color vision modeling to demonstrate how correlated evolution of spectral tuning is necessary to achieve even sampling of the light spectrum and thereby maintain near-optimal color discrimination. The pioneering eye doctor André Rochon-Duvigneaud once wrote that “a bird is a wing guided by an eye”. With this statement, he underscored the sophistication of the bird’s eye, which surpasses our own in several respects. Compared to humans who have three types of cone photoreceptor, birds have four, meaning they can see an extra dimension of color. Birds precisely tune their violet-, blue-, green- and red-sensitive cones by coupling light-sensitive proteins with light-filtering pigments called carotenoids. This combination of sensors and filters increases the number of colors a bird can see. Another exceptional aspect of bird vision is that some species – for example finches and sparrows – can see ultraviolet (UV) light. This ability results from a change in the light-sensitive protein within the violet cone photoreceptor that shifts its sensitivity towards UV light. This expansion of vision into the UV is complemented by a shift in the sensitivity of the blue cone photoreceptor. However, it is not well understood exactly how the sensitivity of the blue cone is shifted and how this shift impacts color vision. To find answers to these questions, Toomey et al. characterized the light-filtering carotenoid pigments from bird species with violet or UV sensitivity, and used computational models of bird vision to predict how these pigments affect the number of colors a bird can see. This approach revealed that blue cone sensitivity is fine-tuned through a change in the chemical structure of the light-filtering carotenoid pigments within the photoreceptor. Computational models also indicated the sensitivity of the violet and blue cones must shift in a coordinated manner to maximize the number of colors a bird can see. These results suggest that both blue and violet cone cells have been fine-tuned during evolution to enhance color vision in birds. An important next step is to investigate the underlying molecular mechanisms that coordinate the modification of the carotenoid pigments and the tuning of light-sensitive proteins in a wide range of bird species.

The emergence of macrosystems ecology (MSE), which focuses on regional- to continental-scale ecological patterns and processes, builds upon a history of long-term and broad-scale studies in ecology. Scientists face the difficulty of integrating the many elements that make up macrosystems, which consist of hierarchical processes at interacting spatial and temporal scales. Researchers must also identify the most relevant scales and variables to be considered, the required data resources, and the appropriate study design to provide the proper inferences. The large volumes of multi-thematic data often associated with macrosystem studies typically require validation, standardization, and assimilation. Finally, analytical approaches need to describe how cross-scale and hierarchical dynamics and interactions relate to macroscale phenomena. Here, we elaborate on some key methodological challenges of MSE research and discuss existing and novel approaches to meet them.

An ultralow-standby-power technology has been developed in both 0.18-µm and 0.13-µm lithography nodes for embedded and standalone SRAM applications. The ultralow-leakage sixtransistor (6T) SRAM cell sizes are 4.81 µm^sup 2^ and 2.34 µm^sup 2^, corresponding respectively to the 0.18-µm and 0.13-µm design dimensions. The measured array standby leakage is equal to an average cell leakage current of less than 50 fA per cell at 1.5 V, 25°C and is less than 400 fA per cell at 1.5 V, 85°C. Dual gate oxides of 2.9 nm and 5.2 nm provide optimized cell leakage, I/O compatibility, and performance. Analyses of the critical parasitic leakage components and paths within the 6T SRAM cell are reviewed in this paper. In addition to the wellknown gate-oxide leakage limitation for ULP technologies, three additional limits facing future scaled ULP technologies are discussed. [PUBLICATION ABSTRACT]