The role of CRP and inflammation in the pathogenesis of age-related macular degeneration

NLRP3 and autophagy in retinal ganglion cell inflammation in age-related macular degeneration: potential therapeutic implications

Retinal degenerative diseases were a large group of diseases characterized by the primary death of retinal ganglion cells (RGCs). Recent studies had shown an interaction between autophagy and nucleotide-binding oligomerization domain-like receptor 3 (NLRP3) inflammasomes, which may affect RGCs in retinal degenerative diseases. The NLRP3 inflammasome was a protein complex that, upon activation, produces caspase-1, mediating the apoptosis of retinal cells and promoting the occurrence and development of retinal degenerative diseases. Upregulated autophagy could inhibit NLRP3 inflammasome activation, while inhibited autophagy can promote NLRP3 inflammasome activation, which leaded to the accelerated emergence of drusen and lipofuscin deposition under the neurosensory retina. The activated NLRP3 inflammasome could further inhibit autophagy, thus forming a vicious cycle that accelerated the damage and death of RGCs. This review discussed the relationship between NLRP3 inflammasome and autophagy and its effects on RGCs in age-related macular degeneration, providing a new perspective and direction for the treatment of retinal diseases.

Mitochondrial damage and clearance in retinal pigment epithelial cells

Age-related macular degeneration (AMD) is a devastating eye disease that causes permanent vision loss in the central part of the retina, known as the macula. Patients with such severe visual loss face a reduced quality of life and are at a 1.5 times greater risk of death compared to the general population. Currently, there is no cure for or effective treatment for dry AMD. There are several mechanisms thought to underlie the disease, for example, ageing-associated chronic oxidative stress, mitochondrial damage, harmful protein aggregation and inflammation. As a way of gaining a better understanding of the molecular mechanisms behind AMD and thus developing new therapies, we have created a peroxisome proliferator-activated receptor gamma coactivator 1-alpha and nuclear factor erythroid 2-related factor 2 (PGC1α/NFE2L2) double-knockout (dKO) mouse model that mimics many of the clinical features of dry AMD, including elevated levels of oxidative stress markers, damaged mitochondria, accumulating lysosomal lipofuscin and extracellular drusen-like structures in retinal pigment epithelial cells (RPE). In addition, a human RPE cell-based model was established to examine the impact of non-functional intracellular clearance systems on inflammasome activation. In this study, we found that there was a disturbance in the autolysosomal machinery responsible for clearing mitochondria in the RPE cells of one-year-old PGC1α/NFE2L2-deficient mice. The confocal immunohistochemical analysis revealed an increase in autophagosome marker microtubule-associated proteins 1A/1B light chain 3B (LC3B) as well as multiple mitophagy markers such as PTE-induced putative kinase 1 (PINK1) and E3 ubiquitin ligase (PARKIN), along with signs of damaged mitochondria. However, no increase in autolysosome formation was detected, nor was there a colocalization of the lysosomal marker LAMP2 or the mitochondrial marker, ATP synthase β. There was an upregulation of late autolysosomal fusion Ras-related protein (Rab7) in the perinuclear space of RPE cells, together with autofluorescent aggregates. Additionally, we observed an increase in the numbers of Toll-like receptors 3 and 9, while those of NOD-like receptor 3 were decreased in PGC1α/NFE2L2 dKO retinal specimens compared to wild-type animals. There was a trend towards increased complement component C5a and increased involvement of the serine protease enzyme, thrombin, in enhancing the terminal pathway producing C5a, independent of C3. The levels of primary acute phase C-reactive protein and receptor for advanced glycation end products were also increased in the PGC1α/NFE2L2 dKO retina. Furthermore, selective proteasome inhibition with epoxomicin promoted both nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and mitochondrial-mediated oxidative stress, leading to the release of mitochondrial DNA to the cytosol, resulting in potassium efflux-dependent activation of the absent in melanoma 2 (AIM2) inflammasome and the subsequent secretion of interleukin-1β in ARPE-19 cells. In conclusion, the data suggest that there is at least a relative decrease in mitophagy, increases in the amounts of C5 and thrombin and decreased C3 levels in this dry AMD-like model. Moreover, selective proteasome inhibition evoked mitochondrial damage and AIM2 inflammasome activation in ARPE-19 cells.

Minimal effect of sleep on the risk of age-related macular degeneration: a Mendelian randomization study

Aims

Observational studies have shown that sleep pattern is associated with age-related macular degeneration (AMD), but whether sleep pattern is a causal factor for AMD remains unclear. This study aims to use Mendelian randomization (MR) analysis to investigate the potential causal relationship between sleep traits and AMD.

Methods

This is a two-sample MR study. The single-nucleotide polymorphisms associated with AMD and early AMD were selected as the outcome from two different genome-wide association studies (GWAS): the early AMD GWAS with 14,034 cases and 91,214 controls, and AMD GWAS with 3,553 cases and 147,089 controls. The datasets of sleep duration, daytime dozing, and sleeplessness were used as exposure, which comprised nearly 0.46 million participants. Inverse-variance weighted method was used as the main result, and comprehensive sensitivity analyses were conducted to estimate the robustness of identified associations and the impact of potential horizontal pleiotropy.

Results

Through MR analysis, we found that sleep duration was significantly associated with AMD (OR = 0.983, 95% CI = 0.970-0.996, P-value = 0.01). We also found suggestive evidence for the association of genetically predicted sleep duration with early AMD, which showed a consistent direction of effect with a marginal significance (OR = 0.724, 95% CI = 0.503-1.041, P-value = 0.08). Sensitivity analyses further supported the robustness of the causal relationship between sleep duration and AMD. However, we were unable to determine the relationship between daytime dozing or sleeplessness and AMD (including early AMD) (P-value > 0.05).

Conclusion

Sleep duration affects the causal risk for AMD; that is, longer sleep duration reduces the risk of AMD, while shorter sleep duration increases the risk of AMD. Although the influence is minimal, keeping adequate sleep duration is recommended, especially for patients with intermediate or advanced AMD.

Metabolomics and Biomarkers in Retinal and Choroidal Vascular Diseases

The retina is one of the most important structures in the eye, and the vascular health of the retina and choroid is critical to visual function. Metabolomics provides an analytical approach to endogenous small molecule metabolites in organisms, summarizes the results of “gene-environment interactions”, and is an ideal analytical tool to obtain “biomarkers” related to disease information. This study discusses the metabolic changes in neovascular diseases involving the retina and discusses the progress of the study from the perspective of metabolomics design and analysis. This study advocates a comparative strategy based on existing studies, which encompasses optimization of the performance of newly identified biomarkers and the consideration of the basis of existing studies, which facilitates quality control of newly discovered biomarkers and is recommended as an additional reference strategy for new biomarker discovery. Finally, by describing the metabolic mechanisms of retinal and choroidal neovascularization, based on the results of existing studies, this study provides potential opportunities to find new therapeutic approaches.

Osteoarthritis Is Associated With an Increased Risk of Age-Related Macular Degeneration: A Population-Based Longitudinal Follow-Up Study

Aims

To investigate the long-term risk of age-related macular degeneration (AMD) in persons with osteoarthritis (OA).

Methods

This retrospective cohort study first enrolled 71,609 subjects diagnosed with OA, and 236,169 without such a diagnosis between January 1, 2002 and December 31, 2005, from the Longitudinal Health Insurance Database 2005. All were aged 40–69. After excluding subjects who had pre-existing AMD and/or who had missing socioeconomic data, frequency matching by sex and age was performed. This resulted in there being 60,274 subjects in each of the final matched OA and non-OA groups. The study participants were followed up to the occurrence of AMD, death, or the end of 2011. We used Cox proportional-hazards regression to estimate the impact of OA on the risk of developing AMD, and performed subgroup analyses stratified by sex and age.

Results

The median follow-up time was 8.9 years, with an interquartile range of 1.4 years. The incidence rate of AMD in the OA group was 2.77 per 1,000 person-years [95% confidence interval (CI), 2.62–2.92], and in the non-OA group, 2.06 per 1,000 person-years (95% CI, 1.94–2.19). The adjusted hazard ratio (HR) of AMD for the OA group was therefore 1.30 (95% CI, 1.20–1.41). In the subgroup analysis stratified by sex for the OA group, the adjusted HRs of AMD were 1.29 in the women's stratum and 1.31 in the men's. When stratified by age, the adjusted HRs of AMD for the younger (40–54 years) and older (55–69 years) strata were 1.28 and 1.31, respectively.

Conclusions

Persons with OA have an increased risk of developing AMD, regardless of age and sex.

The Efficacy and Safety of Brolucizumab for the Treatment of nAMD: A Systematic Review and Meta-Analysis

Introduction: As demonstrated in pivotal clinical trials, brolucizumab can be used to treat neovascular age-related macular degeneration (nAMD) because it antagonizes vascular endothelial growth factor (VEGF) in the vitreous. However, brolucizumab may cause retinal vasculitis obliterans in the presence of inflammation in the eyes. In the present study, a meta-analysis of randomized controlled trials (RCTs) was conducted to evaluate the efficacy and safety of brolucizumab.

Methods:ClinicTrail.gov., Embase, Cochrane Library, and PubMed were retrieved from inception until 31 December 2021 for RCTs assessing the efficacy and safety of brolucizumab. Changes in best corrected visual acuity (BCVA) and central sub-field thickness (CSFT) and incidence of adverse events, serious adverse events, and serious ocular adverse events were extracted from eligible RCTs. A meta-analysis was performed using RevMan 5.4.1.

Results: A total of six RCTs with 3,574 participants were finally involved in this meta-analysis. The changes of best corrected visual acuity (BCVA) showed no statistically significant difference between the brolucizumab-treated group and aflibercept-treated group. Brolucizumab induced higher central sub-field thickness (CSFT) reduction than the control agent (aflibercept). The incidence of adverse events was similar between the brolucizumab group and control group (OR 0.63, 95% CI 0.37 to 1.08, p = 0.09), and brolucizumab caused fewer serious adverse events (OR 0.78, 95% CI 0.63 to 0.95, p = 0.01). However, brolucizumab could lead to more serious ocular adverse events than Lucentis and aflibercept (OR 2.15, 95% CI 1.11 to 4.16, p = 0.02).

Conclusion: Brolucizumab was non-inferior to other anti-VEGF agents in improving BCVA and decreasing CSFT. But it caused more serious ocular adverse events which is worthy of special attention by ophthalmologists.

Apocynum Leaf Extract Suppresses the Progress of Atherosclerosis in Rats via the FKN/SYK/p38 Signal Pathway

To investigate the antiatherosclerotic effects of flavonoids extracted from Apocynum venetum (AVF) leaves in atherosclerotic rats and the underlying mechanisms, a total of 72 male Wistar rats were randomly divided into six groups: control group, model group, simvastatin group, low-dose AVF group, medium-dose AVF group, and high-dose AVF group. Atherosclerosis in rats was induced with a high-fat diet and an intraperitoneal injection of VD₃ once daily for three contiguous days at a total injection dose of 70 U/kg. At the end of the 13^th week, total serum cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) contents were measured. The hematoxylin-eosin (HE) staining was applied to evaluate the morphological changes. The ELISA method was used to detect related inflammatory factors and oxidative stress indicators. The corresponding protein expression and the mRNA level were detected by western blot analysis and reverse transcriptase PCR. HE staining showed that the thoracic aorta wall was thickened, and the aortic subendothelial foam cells and lipid vacuoles were reduced in the medium/high-AVF groups. Similarly, the TC, TG, LDL-C, and malondialdehyde (MDA) levels in the model group were significantly higher, but the HDL-C level and superoxide dismutase (SOD) activity were lower than those of the control group, and these effects were ameliorated by treatment with simvastatin or AVF. ELISA results showed that compared with the control group, the model group C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) results were significantly increased, and the medium AVF and high AVF could significantly reduce the expression of related inflammatory factors. The AVF inhibited intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin mRNA and related protein expression in the aorta in atherosclerotic rats. Western blot analysis also showed that AVF can significantly reduce the protein expression of fractalkine (FKN), spleen tyrosine kinase (SYK), and p38 mitogen-activated protein kinase (p38) in the rat aorta. We believe that the AVF can effectively reduce blood lipid levels in rats with atherosclerosis and delay atherosclerotic progression by inhibiting excessive inflammatory factors and inhibiting related adhesion factors. The underlying mechanism may be related to the FKN/SYK/p38 signaling pathway activity. Our results contribute to validating the traditional use of the Apocynum leaf extract in the treatment of atherosclerosis.

Comparison of Efficacy and Safety between Conbercept and Ranibizumab in Neovascular Age-Related Macular Degeneration: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Conbercept, as a novel vascular endothelial growth factor (VEGF) inhibitor, was approved for the treatment of neovascular age-related macular degeneration (nAMD) in China.

OBJECTIVE

This study aimed to compare the efficacy and safety between conbercept and ranibizumab in patients with nAMD.

METHODS

Several databases (PubMed, Web of Science, China National Knowledge Infrastructure, and WANFANG) were searched for the results of studies describing conbercept and ranibizumab for the treatment of nAMD. Sixteen randomized controlled trials including 1,224 eyes met our search criteria and were assessed.

RESULTS

Conbercept and ranibizumab had comparable effects on improving visual acuity at 3 months (standardized mean difference [SMD]: -0.19; 95% confidence interval [CI]: -0.46 to 0.08; p = 0.17) and 6-12 months (SMD: -0.01; 95% CI: -0.20 to 0.18; p = 0.90). At 3 months and 6-12 months, the differences in the change of central macular thickness in conbercept and ranibizumab groups were 1.06 μm (95% CI: -3.52 to 5.64; p = 0.65) and -0.12 μm (95% CI: -9.26 to 9.02; p = 0.98). In the short term, there was no significant difference between the 2 groups with respect to ocular adverse events (odds ratio [OR]: 0.86; 95% CI: 0.46-1.61; p = 0.63). No significant differences were observed in the recovery rate of choroidal neovascularization leakage between conbercept and ranibizumab at both 3 months (OR: 1.49; 95% CI: 0.83-2.68; p = 0.18) and 6-12 months (OR: 0.66; 95% CI: 0.18-2.43; p = 0.53). There were significant differences between conbercept and ranibizumab in terms of decreasing intraocular pressure (weighted mean difference [WMD]: -1.74; 95% CI: -2.28 to -1.20; p < 0.00001), the plasma VEGF level (WMD: -21.49; 95% CI: -26.28 to -16.70; p < 0.00001), and the C-reactive protein level (WMD: -1.16; 95% CI: -1.45 to -0.87; p < 0.00001) in the short term.

CONCLUSION

Conbercept was similar to ranibizumab in terms of efficacy and safety for the treatment of nAMD in China. Further studies with longer term observation are needed to support this conclusion.

Exogenous administration of hydrogen sulfide alleviates homocysteine induced inflammation in ARPE-19 cells

Plasma homocysteine (Hcy) is an independent risk factor for Age related macular degeneration (AMD) and an inducer of inflammation. Homocysteine catabolism releases hydrogen sulfide (H₂S). H₂S has controversial effects on inflammation. In this study we have analysed the endogenous and exogenous H₂S in modulating inflammation using adult retinal pigment epithelial (ARPE-19) cells as an in vitro model for AMD. ARPE-19 cells were treated with various concentrations of Hcy (15, 30 and 50 μM) for 3 h. Expression of Hcy transulfuration genes (CBS, CSE) by qPCR and western blot. H₂S levels were measured using Free Radical Analyzer System (WPI, USA). The inflammatory markers (IL-6 and IL-8) were evaluated using real-time PCR and ELISA. Hcy exposure increased CBS protein expression, hydrogen sulfide levels and pro-inflammatory cytokines, modulating CBS by silencing did not alter H₂S levels, but inhibition of CSE with PAG inhibited H₂S production and decreased cytokine (IL-6 and IL-8) levels. On the contrary exogenous supply of hydrogen sulfide with NaHS and by compound 1c showed anti-inflammatory effects even in the presence of Hcy. This study shows that exogenous delivery of H₂S decreases inflammation in retinal pigment epithelial cells on exposure to Hcy in ARPE-19 cells.

Oxidative Stress and Mitochondrial Damage in Dry Age-Related Macular Degeneration Like NFE2L2/PGC-1α -/- Mouse Model Evoke Complement Component C5a Independent of C3

Aging-associated chronic oxidative stress and inflammation are known to be involved in various diseases, e.g., age-related macular degeneration (AMD). Previously, we reported the presence of dry AMD-like signs, such as elevated oxidative stress, dysfunctional mitophagy and the accumulation of detrimental oxidized materials in the retinal pigment epithelial (RPE) cells of nuclear factor erythroid 2-related factor 2, and a peroxisome proliferator-activated receptor gamma coactivator 1-alpha (NFE2L2/PGC1α) double knockout (dKO) mouse model. Here, we investigated the dynamics of inflammatory markers in one-year-old NFE2L2/PGC1α dKO mice. Immunohistochemical analysis revealed an increase in levels of Toll-like receptors 3 and 9, while those of NOD-like receptor 3 were decreased in NFE2L2/PGC1α dKO retinal specimens as compared to wild type animals. Further analysis showed a trend towards an increase in complement component C5a independent of component C3, observed to be tightly regulated by complement factor H. Interestingly, we found that thrombin, a serine protease enzyme, was involved in enhancing the terminal pathway producing C5a, independent of C3. We also detected an increase in primary acute phase C-reactive protein and receptor for advanced glycation end products in NFE2L2/PGC1α dKO retina. Our main data show C5 and thrombin upregulation together with decreased C3 levels in this dry AMD-like model. In general, the retina strives to mount an orchestrated inflammatory response while attempting to maintain tissue homeostasis and resolve inflammation.

Associations of sleep apnoea with glaucoma and age-related macular degeneration: an analysis in the United Kingdom Biobank and the Canadian Longitudinal Study on Aging

BACKGROUND

Sleep apnoea, a common sleep-disordered breathing condition, is characterised by upper airway collapse during sleep resulting in transient hypoxia, hypoperfusion of the optic nerve, and spike in intracranial pressure. Previous studies have reported conflicting findings on the association of sleep apnoea with glaucoma, and there are limited reports on the link between sleep apnoea and age-related macular degeneration (AMD).

METHODS

Middle-aged and older participants from the longitudinal United Kingdom (UK) Biobank (n = 502,505) and the Canadian Longitudinal Study on Aging (CLSA; n = 24,073) were included in this analysis. Participants in the UK Biobank and the CLSA were followed for 8 and 3 years, respectively. Participants with diagnosed glaucoma or AMD at baseline were excluded from the analysis. In the UK Biobank, sleep apnoea and incident cases of glaucoma and AMD were identified through hospital inpatient admission, primary care records, and self-reported data. Multivariable Cox proportional hazards models were used to explore associations of sleep apnoea with incidence of glaucoma or AMD.

RESULTS

During the 8-year follow-up in the UK Biobank, glaucoma incidence rates per 1000 person-years were 2.46 and 1.59 for participants with and without sleep apnoea, and the AMD incidence rates per 1000 person-years were 2.27 and 1.42 for participants with and without sleep apnoea, respectively. Multivariable adjusted hazard ratios of glaucoma and AMD risk for sleep apnoea were 1.33 (95% confidence interval [CI] 1.10-1.60, P = 0.003) and 1.39 (95% CI 1.15-1.68, P <  0.001) relative to participants without sleep apnoea. In the CLSA cohort, disease information was collected through in-person interview questionnaires. During the 3-year follow-up, glaucoma incidence rates per 1000 person-years for those with and without sleep apnoea were 9.31 and 6.97, and the AMD incidence rates per 1000 person-years were 8.44 and 6.67, respectively. In the CLSA, similar associations were identified, with glaucoma and AMD odds ratios of 1.43 (95% CI 1.13-1.79) and 1.39 (95% CI 1.08-1.77), respectively, in participants with sleep apnoea compared to those without sleep apnoea (both P <  0.001).

CONCLUSIONS

In two large-scale prospective cohort studies, sleep apnoea is associated with a higher risk of both glaucoma and AMD. These findings indicate that patients with sleep apnoea might benefit from regular ophthalmologic examinations.

Age-Related Macular Degeneration: What Do We Know So Far?

Ageing is a natural process that everyone experiences and nobody is an exception. With ageing, our body experiences physiological changes. In this article, the focus is made on the physiological changes of our eyes related to ageing and age-related macular degeneration (AMD), which is the most common cause of incurable visual impairment in developed countries. With ageing populations increasing in many countries, more and more patients will have AMD in a foreseeable future. In Eastern Europe, blindness due to AMD, currently, is approximately 20% and there has been an increasing trend depicted in the future. Generally, AMD can be divided into early stages and two forms in an advanced (late) stage. Advanced AMD form includes neovascular AMD (wet) and geographic atrophy (late dry), both of these are associated with substantial, progressive visual impairment. The pathogenesis of AMD is complex and, by far, not completely understood. Multiple factors have been studied, for example: environmental factor, genetic factor (complement factor H), lifestyle. It has been proved that they are linked to higher the risk of developing of AMD, however, the actual pathogenesis is not yet formulated. AMD progression can also be a culprit to certain biochemical events and molecular changes linked to inflammation and pathological angiogenesis. In nowadays, we do have diagnostic methods for both early and late forms of AMD as well as ways to prevent progression of early AMD and wet AMD. However, until now, there is still no treatment for dry AMD. This article is a brief review of AMD and may hopefully lead to some future directions in early diagnostic methods and treating dry AMD.

Pregnancy as a model for aging

The process of aging can be defined as the sum accumulation of damages and changes in metabolism during the life of an organism, due to both genetic predisposition and stochastic damage. During the gestational period and following parturition, similar damage can be seen due to the strenuous effect on the maternal body, exhibited on both the physiological and cellular level. In this review, we will focus on the similar physiological and cellular characteristics exhibited during pregnancy and aging, including induction of and response to oxidative stress, inflammation, and degradation of telomeres. We will evaluate any similar processes between aging and pregnancy by comparing common biomarkers, pathologies, and genetic and epigenetic effects, to establish the pregnant body as a model for aging. This review will approach the connection both in respect to current theories on aging as a byproduct of natural selection, and regarding unrelated biochemical similarities between the two, drawing on existing studies and models in humans and other species where relevant alike. Furthermore, we will show the response of the pregnant body to these changes, and through that illuminate unique areas of potential study to advance our knowledge of the maladies relating to aging and pregnancy, and an avenue for solutions.

The Association of Serum Iron-Binding Proteins and the Antioxidant Parameter Levels in Age-Related Macular Degeneration

PURPOSE

Age-related macular degeneration (AMD) is the leading cause of the irreversible central visual loss among the elderly in the developed countries. Iron is considered a potent generator of the oxidative damage whose levels increase with age, potentially exacerbating the age-related diseases. The aim of this study was to assess the serum values of iron, and iron-binding proteins (transferrin, ferritin, and haptoglobin) in patients with AMD along with the parameters of the antioxidant defense: superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase, and total antioxidant status (TAS), in order to analyze the possible impact of iron and iron-binding proteins to the development of oxidative stress in AMD patients, and the association of the selected parameters with the AMD. In addition, the aim was to examine the gender differences and calculate the cutoff points of tested parameters that could be associated with AMD.

MATERIAL AND METHODS

A cross-sectional study included 55 AMD patients aged 71.7 ± 7.36 years and 65 aged-matched control subjects aged 70.25 ± 6.46 years.

RESULTS

Significantly lower ferritin (P = 0.025), SOD (P = 0.026), GPx (P = 0.019), and TAS (P < 0.004) values were found in patients with AMD compared to the controls (P < 0.05). Significant association of GPx < 27 U/gHb (odds ratio [OR]: 1.13; 95% confidence interval [CI] 0.78-2.10; P = 0.049), TAS < 1.25 mmol/L (OR: 5.77; 95% CI 0.98-367.0; P < 0.000), ferritin < 84.8 pg/mL (OR: 2.52; 95% CI 1.37-4.62; P = 0.002), and haptoglobin<1.51 g/L (OR: 1.94; 95% CI 1.05-3.56; P = 0.031) was found with the AMD. According to receiver operating characteristic curve analysis, ferritin concentration <84.8 pg/L, GPx < 27 U/gHb, and TAS < 1.25 mmol/L have sufficient predictive ability for AMD.

CONCLUSION

Significantly reduced capacity of the antioxidant defense system and iron-binding storage proteins (ferritin) found in AMD could have an important role in the development of increase oxidative stress in AMD patients.

The association of enzymatic and non-enzymatic antioxidant defense parameters with inflammatory markers in patients with exudative form of age-related macular degeneration

There are evidence that oxidative stress and inflammation are involved in the pathogenesis of the age-related macular degeneration (AMD). The aim of this study was to analyze the antioxidant defense parameters and inflammatory markers in patients with exudative form of AMD (eAMD), their mutual correlations and association with the specific forms of AMD. The cross-sectional study, included 75 patients with the eAMD, 31 patients with the early form, and 87 aged-matched control subjects. Significantly lower SOD, TAS and albumin values and higher GR, CRP and IL-6 were found in the eAMD compared to the early form (p<0.05). Significant negative correlations were found between GPx and fibrinogen (r = -0.254), TAS and IL-6 (r = -0.999) and positive correlations between uric acid and CRP (r = 0.292), IL-6 and uric acid (r = 0.398) in the eAMD. A significant association of CRP (OR: 1.16, 95% CI: 1.03-1.32, p = 0.018), fibrinogen (OR: 2.21, 95% CI: 1.14-4.85, p = 0.021), TAS (OR: 7.45, 95% CI: 3.97-14.35, p = 0.0001), albumin (OR: 1.25, 95% CI: 1.11-1.41, p = 0.0001) and uric acid (OR: 1.006, 95% CI: 1.00-1.02, p = 0.003) was found with the eAMD. In conclusion it may be suggested, there is a significant impairment of antioxidant and inflammatory parameter levels in eAMD patients. In addition, significant association exists between the tested inflammatory markers and antioxidant parameters with late-eAMD.

Potential relationship between periodontal diseases and eye diseases

Periodontal diseases are inflammatory lesions initiated by oral bacteria and lead to the destruction of the supporting structures of the teeth (gingiva, periodontal ligament and alveolar bone) in susceptible patient. Via several biological mechanisms, periodontal diseases have been associated with multiple systemic diseases, such as rheumatoid arthritis, diabetes, cardiovascular diseases, Alzheimer's disease and adverse pregnancy outcomes. Similarly certain eye diseases have been associated with systemic diseases of the inflammatory pathway. We hypothesized that periodontal diseases are associated with eye diseases. Thus using literature data we find that several studies have reported that eye disorders are associated with the presence of periodontal diseases. But the mechanisms of this relationship are not clear. However the innate immune response involvement, the sharing of similar risk factors in pathogenesis and the changes of eye choroid thickness may be suggested as several hypotheses to explain this potential association.

Impact of Cocoa Consumption on Inflammation Processes-A Critical Review of Randomized Controlled Trials

Background: Cocoa flavanols have strong anti-inflammatory properties in vitro. If these also occur in vivo, cocoa consumption may contribute to the prevention or treatment of diseases mediated by chronic inflammation. This critical review judged the evidence for such effects occurring after cocoa consumption. Methods: A literature search in Medline was performed for randomized controlled trials (RCTs) that investigated the effects of cocoa consumption on inflammatory biomarkers. Results: Thirty-three RCTs were included, along with 9 bolus and 24 regular consumption studies. Acute cocoa consumption decreased adhesion molecules and 4-series leukotrienes in serum, nuclear factor κB activation in leukocytes, and the expression of CD62P and CD11b on monocytes and neutrophils. In healthy subjects and in patients with cardiovascular diseases, most regular consumption trials did not find any changes except for a decreased number of endothelial microparticles, but several cellular and humoral inflammation markers decreased in patients suffering from type 2 diabetes and impaired fasting glucose. Conclusions: Little evidence exists that consumption of cocoa-rich food may reduce inflammation, probably by lowering the activation of monocytes and neutrophils. The efficacy seems to depend on the extent of the basal inflammatory burden. Further well-designed RCTs with inflammation as the primary outcome are needed, focusing on specific markers of leukocyte activation and considering endothelial microparticles as marker of vascular inflammation.

The association between statin use and risk of age-related macular degeneration

The aim of the present study was to evaluate the association between statin use and the risk of age-related macular degeneration (AMD). A systematic search of the PubMed, EMBASE and ISI web of science databases was used to identify eligible published literatures without language restrictions up to April 2015. Summary relative ratios (RRs) and 95% CIs were estimated using a fixed-effect or random-effects model. A total of 14 studies met the inclusion criteria and were included in this meta-analysis. No significant association was observed between statin use and the risk of any AMD (RR, 0.95; 95% CI, 0.74-1.15); and stratified analysis showed that statins had a significantly different effects on early and late stages of AMD. For early AMD, statin use significantly reduced the risk approximately 17% (RR, 0.83; 95% CI, 0.66-0.99). At the late stage, we observed a significant protective association of statin use with exudative AMD (RR, 0.90; 95% CI, 0.80-0.99), in contrast with the absent association between statins and geographic atrophy (RR, 1.16; 95% CI, 0.77-1.56). These results demonstrated that statin use was protective for early and exudative AMD. Additional large prospective cohort studies and RCTs are required to determine the potential effect of statins on AMD prevention.

CETP/LPL/LIPC gene polymorphisms and susceptibility to age-related macular degeneration

Three high-density lipoprotein (HDL)-related loci have been reported to be associated with age-related macular degeneration (AMD), but the results were inconsistent. In this study, the cholesteryl ester transfer protein (CETP) rs3764261 variant was significantly associated with an increased risk of AMD (odds ratio [OR] = 1.13, 95% confidence interval [CI]: 1.05–1.21, P < 0.001), and the hepatic lipase (LIPC) rs10468017 variant was associated with a significantly decreased risk of AMD (OR = 0.81, CI: 0.76–0.86, P < 0.001). Individuals carrying the lipoprotein lipase (LPL) rs12678919 polymorphism (A → G) had no significant change in the risk of developing AMD (OR = 1.01, CI: 0.92–1.10, P = 0.17). After adjusting for the complement factor H (CFH) gene, both CETP and LPL conferred a significantly increased AMD risk (OR_CETP = 1.17, CI: 1.08–1.26, P < 0.001; OR_LPL = 1.11, CI: 1.01–1.22, P = 0.02). Subgroup analysis based on ethnicity revealed a significant association between the CETP variant and AMD in both Americans (OR = 1.12, CI: 1.02–1.23, P = 0.01) and Europeans (OR = 1.10, CI: 1.01–1.19, P = 0.011). This meta-analysis revealed that both CETP rs3764261 and LIPC rs10468017 polymorphisms were significantly associated with AMD risk. After adjustment for the CFH gene, CETP/LPL conferred a significantly increased susceptibility to the disease, indicating potential interactions among genes in the complement system and the lipid metabolism pathway.

Efficacy and vitreous levels of topical NSAIDs

INTRODUCTION

Nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the most commonly prescribed medications and are routinely used for their analgesic, antipyretic, and anti-inflammatory properties. Because of their potent cyclooxygenase-inhibitory activity, they can inhibit pro-inflammatory prostaglandin synthesis, leading to complex inflammatory cascades. NSAIDs have been broadly used systemically for many decades and have recently become commercially available in the form of topical ophthalmic formulations. NSAIDs are weak acids with pKa values mostly between 3.5 and 4.5 and are poorly water-soluble. New, aqueous ophthalmic solutions of NSAIDs that afford better tissue penetration have recently been developed. In ophthalmological practice, topical NSAIDs are mostly used to stabilize pupillary dilation during intraocular surgery, manage postoperative pain and inflammation, and treat pseudophakic cystoid macular edema.

AREAS COVERED

This review focuses on the vitreous penetration of topical NSAIDs and their potential clinical applications in the treatment of retinal diseases.

EXPERT OPINION

A growing body of evidence suggests that NSAIDs may be beneficial in the treatment of age-related macular degeneration, diabetic retinopathy, and ocular tumors. Recent studies from our group and other authors have shown that the vitreous levels of NSAID exceed the median inhibitory concentration, which can significantly decrease vitreous PGE2 levels.

Interleukin-1β Level Is Increased in Vitreous of Patients with Neovascular Age-Related Macular Degeneration (nAMD) and Polypoidal Choroidal Vasculopathy (PCV)

Purpose

To examine the expression of pro-interleukin-1β (pro-IL-1β) and interleukin-1β (IL-1β) in the vitreous body of patients with neovascular age-related macular degeneration(nAMD), polypoidal choroidal vasculopathy (PCV), proliferative diabetic retinopathy (PDR), retinal vein occlusion (RVO) or Eales’ disease to further elucidate the role of IL-1β and inflammation in the pathogenesis of neovascular retinal disease.

Design

Prospective clinical laboratory investigation study.

Methods

All patients enrolled had vitreous hemorrhage due to nAMD, PCV, PDR, RVO or Eales’ disease that required vitrectomy. Patients were excluded for any history of active intraocular inflammation, or other ophthalmic surgery besides vitrectomy. Control samples were obtained from patients with idiopathic macular epiretinal membrane. A total of fifty vitreous samples were collected from patient during vitrectomy. Pro-IL-1β and IL-1β expression were measured by enzyme-linked immunosorbent assay (ELISA). Results were analyzed statistically using nonparametric tests.

Results

Expression of pro-IL-1β protein was increased by 2.83-fold and 9.19-fold in PCV and nAMD vitreous samples relative to control, respectively. Expression of IL-β protein was increased by 10-fold and 4.83-fold in PCV and nAMD vitreous samples relative to control, respectively.

Conclusions

Our results demonstrate that expression of pro-IL-1β and IL-1β proteins is higher in PCV and nAMD. The roles of pro-IL-1β and IL-1β as inflammatory mediators in the development of PCV and nAMD may be associated with photoreceptor degeneration and neovascularization which necessitates further study.

Ocular surface temperature in age-related macular degeneration

Background. The aim of this study is to investigate the ocular thermographic profiles in age-related macular degeneration (AMD) eyes and age-matched controls to detect possible hemodynamic abnormalities, which could be involved in the pathogenesis of the disease. Methods. 32 eyes with early AMD, 37 eyes with atrophic AMD, 30 eyes affected by untreated neovascular AMD, and 43 eyes with fibrotic AMD were included. The control group consisted of 44 healthy eyes. Exclusion criteria were represented by any other ocular diseases other than AMD, tear film abnormalities, systemic cardiovascular abnormalities, diabetes mellitus, and a body temperature higher than 37.5°C. A total of 186 eyes without pupil dilation were investigated by infrared thermography (FLIR A320). The ocular surface temperature (OST) of three ocular points was calculated by means of an image processing technique from the infrared images. Two-sample t-test and one-way analysis of variance (ANOVA) test were used for statistical analyses. Results. ANOVA analyses showed no significant differences among AMD groups (P value >0.272). OST in AMD patients was significantly lower than in controls (P > 0.05). Conclusions. Considering the possible relationship between ocular blood flow and OST, these findings might support the central role of ischemia in the pathogenesis of AMD.

Short duration of sleep is associated with elevated high-sensitivity C-reactive protein level in Taiwanese adults: a cross-sectional study

BACKGROUND

Elevated plasma levels of high-sensitivity C-reactive protein (hs-CRP) have been associated with increased adverse health outcomes. The aim of this study was to investigate the association of sleep duration with risk of elevated hs-CRP levels in Taiwanese adults.

METHODS

We examined the association between sleep duration and hs-CRP in 353 healthy adults recruited from the physical examination center at a regional hospital in southern Taiwan. Elevated hs-CRP was defined as a plasma level ≥ 0.20 mg/dL. Short sleep duration was defined as ≤ 5.5 h per day. Multiple logistic regression analysis was used to assess the association of short duration of sleep with elevated hs-CRP levels.

RESULTS

In this study, short duration of sleep (odds ratio [OR] = 2.20; 95% confidence interval [CI]: 1.11-4.30), aged 70 years or older (OR = 4.58; 95% CI: 1.70-12.66), menopause (OR = 2.81; 95% CI: 1.52-5.3), higher heart rate (OR = 1.38; 95% CI: 1.10-1.75), higher body mass index (OR = 1.20; 95% CI: 1.09-1.34), higher white blood cell count (OR = 1.38; 95% CI: 1.14-1.66), and higher uric acid level (OR = 1.31; 95% CI: 1.06-1.63) were significantly associated with an increased risk of elevated hs-CRP levels.

CONCLUSIONS

In this study of healthy Taiwanese adults, short duration of sleep was significantly associated with elevated hs-CRP levels. Activation of pro-inflammatory pathways might represent a mechanism by which short sleep duration affects health.

The effect of high-calorie meal consumption on oxidative stress and endothelial dysfunction in healthy male adults

Several authors have reported the association of postprandial hypertriglyceridemia with oxidative stress, systemic inflammation and endothelial dysfunction. Our aim was to investigate the effect of high-calorie meal on blood markers of oxidative stress and endothelial dysfunction and the association of APOA5 -1131T/C and -250G/A hepatic lipase (HL) polymorphisms with postprandial triglyceride response. This study included 102 healthy male volunteers. All participants consumed a high-calorie meal (823 calories, 50 g fat, 28 g protein, 60 g carbohydrates). Total cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol, hsCRP, TAS and ICAM-1 were measured at fasting state and postprandially. APOA5 -1131T/C and -250G/A HL polymorphisms were also determined. Postprandial triglycerides were significantly increased (1.4 (1.1-2.1) vs. 2.4 (1.9-3.3) mmol/l, P<0.001). Average triglyceride increase was 1.0+/-0.7 mmol/l (65 %). Concentration of triglycerides, HDL-cholesterol, LDL-cholesterol, TAS and ICAM-1 differed significantly between the fasting state and postprandial measurements (P<0.001). However, those differences were within the limits of analytical imprecision. Other parameters did not change 3 h after the meal. Triglycerides response did not differ respective to the APOA5 and HL polymorphisms. Family history of hypertension and acute myocardial infarction were associated with higher postprandial triglyceride concentrations. Postprandial hypertriglyceridemia is not associated with increased concentrations of hsCRP, TAS and ICAM-1. Furthermore, APOA5 -1131T/C and -250G/A HL polymorphisms are not associated with different postprandial triglyceride response.