IL-1β induces IL-6 production in retinal Müller cells predominantly through the activation of p38 MAPK/NF-κB signaling pathway

Natural plant medications for the treatment of retinal diseases: The blood-retinal barrier as a clue

BACKGROUND

Retinal diseases significantly contribute to the global burden of visual impairment and blindness. The occurrence of retinal diseases is often accompanied by destruction of the blood‒retinal barrier, a vital physiological structure responsible for maintaining the stability of the retinal microenvironment. However, detailed summaries of the factors damage the blood‒retinal barrier and treatment methods involving natural plant medications are lacking.

PURPOSE

To comprehensively summarize and analyze the protective effects of active substances in natural plant medications on damage to the blood-retina barrier that occurs when retinal illnesses, particularly diabetic retinopathy, and examine their medicinal value and future development prospects.

METHODS

In this study, we searched for studies published in the ScienceDirect, PubMed, and Web of Science databases. The keywords used included natural plant medications, plants, natural herbs, blood retinal barrier, retinal diseases, diabetic retinopathy, age-related macular degeneration, and uveitis. Chinese herbal compound articles, non-English articles, warning journals, and duplicates were excluded from the analysis.

RESULTS

The blood‒retinal barrier is susceptible to high glucose, aging, immune responses, and other factors that destroy retinal homeostasis, resulting in pathological changes such as apoptosis and increased vascular permeability. Existing studies have shown that the active compounds or extracts of many natural plants have the effect of repairing blood-retinal barrier dysfunction. Notably, berberine, puerarin, and Lycium barbarum polysaccharides exhibited remarkable therapeutic effects. Additionally, curcumin, astragaloside IV, hesperidin, resveratrol, ginsenoside Rb1, luteolin, and Panax notoginseng saponins can effectively protect the blood‒retinal barrier by interfering with distinct pathways. The active ingredients found in natural plant medications primarily repair the blood‒retinal barrier by modulating pathological factors such as oxidative stress, inflammation, pyroptosis, and autophagy, thereby alleviating retinal diseases.

CONCLUSION

This review summarizes a series of plant extracts and plant active compounds that can treat retinal diseases by preventing and treating blood‒retinal barrier damage and provides reference for the research of new drugs for treating retinal diseases.

The complement system and diabetic retinopathy

Diabetic retinopathy (DR) is one of the common microvascular complications of diabetes mellitus and is the main cause of visual impairment in diabetic patients. The pathogenesis of DR is still unclear. The complement system, as an important component of the innate immune system in addition to defending against the invasion of foreign microorganisms, is involved in the occurrence and development of DR through 3 widely recognized complement activation pathways, the complement regulatory system, and many other pathways. Molecules such as C3a, C5a, and membrane attacking complex, as important molecules of the complement system, are involved in the pathologenesus of DR, either through direct damaging effects or by activating cells (microglia, macroglia, etc.) in the retinal microenvironment to contribute to the pathological damage of DR indirectly. We review the integral association of the complement system and DR to further understand the pathogenesis of DR and possibly provide a new strategy for itstreatment.

Short-term effect of intravitreal dexamethasone implant in refractory diabetic macular edema

PURPOSE

To evaluate the short-term effects (hours-days) of intravitreal dexamethasone implant (IDI) in eyes with diabetic macular edema (DME) refractory to anti-vascular endothelial growth factor (VEGF) injections.

METHODS

This was a prospective, single-arm, interventional clinical series. Eyes with DME and 3-9 injections of ranibizumab without a good response were included. Patients underwent a single IDI. Best-corrected visual acuity (BCVA) measurement, complete ophthalmic evaluation, and spectral-domain optical coherence tomography (SD-OCT) were performed at baseline, 2 h, 3 h, 24 h, 7 days, and 1 month. The main outcomes were change in central retinal thickness (CRT) on SD-OCT and BCVA.

RESULTS

Fifteen eyes of 15 patients were included. Mean CRT decreased after treatment from 515.87 µm ± 220.00 µm at baseline to 489.60 µm ± 176.53 µm after 2 h (p = 0.126), and 450.13 µm ± 163.43 at 24 h (p = 0.006). Change in BCVA was from 0.85 ± 0.44 logMAR baseline to 0.58 ± 0.37 log MAR at 1 month (p = 0.003).

CONCLUSIONS

Eyes treated with IDI showed significant decrease in CRT detectable 1 day after injection. In some patients, the effect could be observed 3 h post-implantation.

TRIAL REGISTRATION

Clinicaltrials.gov NCT05736081 . Registered 20 February 2023, Retrospectively registered.

Less is more: Self-amplifying mRNA becomes self-killing upon dose escalation in immune-competent retinal cells

In the last few years, mRNA therapeutics experienced a new wave of interest as therapy for retinal diseases. Nevertheless, despite the widespread use of mRNA vaccines in the COVID-19 pandemic, mRNA delivery to the eye is still in its infancy. Recently, our research group has demonstrated that after subretinal and intravitreal delivery of modified mRNA, the number of transfected retinal cells and protein expression per cell remains limited. In this study, we aimed to tackle this limitation by using self-amplifying mRNA (saRNA), which in theory will increase the duration and level of protein expression when only a few mRNA molecules reach their target cells. A one-on-one comparison between modified mRNA and saRNA in two immune-competent human retinal cell types, including Müller cells and retinal pigment epithelial cells, and in immune-deficient BHK-21 cells revealed that saRNA delivery induced an innate immune response blocking its own translation above a certain dose threshold. Removal of double-stranded (ds)RNA byproducts by cellulose-based purification and addition of the innate immune inhibitor B18R remarkably improved translation from saRNA through a reduction in innate immune response. Taken together, when saRNA is applied for retinal disease, the dose should be controlled and measures should be taken to limit immunogenicity.

Glial cell alterations in diabetes-induced neurodegeneration

Type 2 diabetes mellitus is a global epidemic that due to its increasing prevalence worldwide will likely become the most common debilitating health condition. Even if diabetes is primarily a metabolic disorder, it is now well established that key aspects of the pathogenesis of diabetes are associated with nervous system alterations, including deleterious chronic inflammation of neural tissues, referred here as neuroinflammation, along with different detrimental glial cell responses to stress conditions and neurodegenerative features. Moreover, diabetes resembles accelerated aging, further increasing the risk of developing age-linked neurodegenerative disorders. As such, the most common and disabling diabetic comorbidities, namely diabetic retinopathy, peripheral neuropathy, and cognitive decline, are intimately associated with neurodegeneration. As described in aging and other neurological disorders, glial cell alterations such as microglial, astrocyte, and Müller cell increased reactivity and dysfunctionality, myelin loss and Schwann cell alterations have been broadly described in diabetes in both human and animal models, where they are key contributors to chronic noxious inflammation of neural tissues within the PNS and CNS. In this review, we aim to describe in-depth the common and unique aspects underlying glial cell changes observed across the three main diabetic complications, with the goal of uncovering shared glial cells alterations and common pathological mechanisms that will enable the discovery of potential targets to limit neuroinflammation and prevent neurodegeneration in all three diabetic complications. Diabetes and its complications are already a public health concern due to its rapidly increasing incidence, and thus its health and economic impact. Hence, understanding the key role that glial cells play in the pathogenesis underlying peripheral neuropathy, retinopathy, and cognitive decline in diabetes will provide us with novel therapeutic approaches to tackle diabetic-associated neurodegeneration.

Bioactive compounds in pomace olive oil modulate the inflammatory response elicited by postprandial triglyceride-rich lipoproteins in BV-2 cells

Modulation of microglial response could be a target to reduce neuroinflammation associated with Alzheimer's disease. In this study, we propose that lipophilic bioactive molecules present in pomace olive oil (POO), transported in triglyceride-rich lipoproteins (TRLs), are able to modulate microglial high-oleic sunflower oil (HOSO, points) or pomace olive oil (POO, stripes). In order to prove this hypothesis, a randomized crossover postprandial trial was performed in 18 healthy young women. POO was assayed in opposition to high-oleic sunflower oil (HOSO), a common dietary oil which shares with POO an almost identical fatty acid composition but lacks certain biomolecules with recognized antioxidant and anti-inflammatory activities. TRLs were isolated from blood at the baseline and 2 and 4 hours postprandially and used to treat BV-2 cells to assess their ability to modulate the microglial function. We found that the intake of POO leads to the constitution of postprandial TRLs that are able to modulate the inflammatory response in microglia compared to HOSO. TRL-derived POO reduced the release of pro-inflammatory cytokines (tumor necrosis factor-α, and interleukins 1β and 6) and nitric oxide and downregulated genes codifying for these cytokines and inducible nitric oxide synthase (iNOS) in BV-2 cells. Moreover, the ingestion of POO by healthy women slightly improved glycemic control and TRL clearance throughout the postprandial phase compared to HOSO. In conclusion, we demonstrated that consuming POO results in postprandial TRLs containing lipophilic bioactive compounds capable of regulating the inflammatory response prompted by microglial activation.

Protective effect of evolocumab on Müller cells in the rat retina under hyperglycaemic and hypoxic conditions

AIMS

In this study, rat retinal Müller cells (RMCs) were cultured in vitro to investigate the protective mechanism of evolocumab on rat RMCs in diabetes mellitus (DM) and the expression of relevant inflammatory factors.

METHODS

The expression of proprotein convertase subtilisin/kexin type 9 (PCSK9) in the retinal tissues of diabetic rats was detected by immunohistochemistry. Sprague-Dawley (SD) rats at 5-7 d of life were selected as the source of RMCs and divided equally into three groups of 12 rats/24 eyes each. The effect of CoCl2 and evolocumab on the cellular activity of RMCs was determined by CCK-8 assay. The effect of CoCl2 and evolocumab on the migration level of RMCs after 72 h was measured by scratch test and the expression of various proteins after 72 h was measured by Western blot.

RESULTS

In STZ rats, the expression of PCSK9 was significantly upregulated in the retina, especially in the inner nuclear layer, which is mainly composed of RMCs. High glucose and CoCl2 stimulation markedly elevated PCSK9 and GFAP expression at the protein level in RMCs (P < 0.05). Evolocumab treatment (100 μg/ml) reduced the expression and secretion of inflammatory factors in stimulated RMCs (P < 0.05). Furthermore, evolocumab downregulates toll-like receptor-4 (TLR-4) levels and inhibited nuclear transcription factor-κB (NF-κB) phosphorylation in RMCs (P < 0.05).

CONCLUSIONS

Evolocumab protects against inflammation in RMCs, at least in part, by negatively regulating the activation of the TLR-4/NF-κB signalling pathway. Evolocumab may be a promising anti-inflammatory therapy for ocular fundus diseases, such as DR.

Glutathione trisulfide prevents lipopolysaccharide-induced retinal inflammation via inhibition of proinflammatory cytokine production in glial cells

We aimed to investigate the impact of glutathione trisulfide (GSSSG) on lipopolysaccharide (LPS)-induced inflammation in retinal glia. Inflammatory responses in mouse-derived glial cells and Wistar rat retinas were stimulated with administration of LPS. Cell survival and proinflammatory cytokine production were examined using the Calcein-AM assay, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Retinal microglia were visualized with immunohistochemistry for Iba1. Administration of LPS (10 µg/mL) or GSSSG (less than 100 µM) did not affect survival of cultured primary Müller cells and established microglial cells (BV-2). RT-qPCR and ELISA indicated that GSSSG inhibited LPS-induced gene upregulation and protein secretion of proinflammatory cytokines in these glial cells and rat retinas. GSSSG inhibited LPS-induced activation of TGF-β-activated kinase 1 (TAK1), which is an upstream kinase of NF-κB, in BV-2 cells. Finally, in vivo experiments indicated that intravitreal administration of GSSSG but not its relative glutathione disulfide (GSSG) inhibited LPS (500 ng)-induced accumulation of Iba1-immunopositive microglia in rat retinas. Taken together, GSSSG has the potential to prevent pathogenesis of inflammation-associated ocular diseases by inhibiting proinflammatory cytokine expression in retinal glial cells.

Suppressing Inflammation for the Treatment of Diabetic Retinopathy and Age-Related Macular Degeneration: Dazdotuftide as a Potential New Multitarget Therapeutic Candidate

Diabetic retinopathy (DR) and age-related macular degeneration (AMD) are major causes of blindness globally. The primary treatment option for DME and neovascular AMD (nAMD) is anti-vascular endothelial growth factor (VEGF) compounds, but this treatment modality often yields insufficient results, and monthly injections can place a burden on the health system and patients. Although various inflammatory pathways and mediators have been recognized as key players in the development of DR and AMD, there are limited treatment options targeting these pathways. Molecular pathways that are interlinked, or triggers of multiple inflammatory pathways, could be promising targets for drug development. This review focuses on the role of inflammation in the pathogenesis of DME and AMD and presents current anti-inflammatory compounds, as well as a potential multitarget anti-inflammatory compound (dazdotuftide) that could be a candidate treatment option for the management of DME and AMD.

Diabetic vascular diseases: molecular mechanisms and therapeutic strategies

Vascular complications of diabetes pose a severe threat to human health. Prevention and treatment protocols based on a single vascular complication are no longer suitable for the long-term management of patients with diabetes. Diabetic panvascular disease (DPD) is a clinical syndrome in which vessels of various sizes, including macrovessels and microvessels in the cardiac, cerebral, renal, ophthalmic, and peripheral systems of patients with diabetes, develop atherosclerosis as a common pathology. Pathological manifestations of DPDs usually manifest macrovascular atherosclerosis, as well as microvascular endothelial function impairment, basement membrane thickening, and microthrombosis. Cardiac, cerebral, and peripheral microangiopathy coexist with microangiopathy, while renal and retinal are predominantly microangiopathic. The following associations exist between DPDs: numerous similar molecular mechanisms, and risk-predictive relationships between diseases. Aggressive glycemic control combined with early comprehensive vascular intervention is the key to prevention and treatment. In addition to the widely recommended metformin, glucagon-like peptide-1 agonist, and sodium-glucose cotransporter-2 inhibitors, for the latest molecular mechanisms, aldose reductase inhibitors, peroxisome proliferator-activated receptor-γ agonizts, glucokinases agonizts, mitochondrial energy modulators, etc. are under active development. DPDs are proposed for patients to obtain more systematic clinical care requires a comprehensive diabetes care center focusing on panvascular diseases. This would leverage the advantages of a cross-disciplinary approach to achieve better integration of the pathogenesis and therapeutic evidence. Such a strategy would confer more clinical benefits to patients and promote the comprehensive development of DPD as a discipline.

A novel model of subretinal edema induced by DL-alpha aminoadipic acid

In this study we described a new model of subretinal edema induced by single intraocular injection of DL-alpha-aminoadipic acid (DLAAA) that can be employed to study the mechanism of retinal edema and test the efficacy or potential toxicity of treatments. The progression of subretinal edema was evaluated by fundus photography, fluorescein angiography and optical coherence tomography for up to 4 weeks following DLAAA injection. The VEGF, IL-6, TNF-α, Occludin, ZO-1, AQP4, Kir4.1, GFAP and GS levels were examined in DLAAA models by immunostaining, immumohistochemical staining and Western blot. Additionally, bulk RNA-seq was used to detect the mechanism involved in DLAAA-induced retinal Müller cellular injuries. In vivo and vitro assays were further conducted to confirm the sequencing results. Subretinal edema was successfully induced by DLAAA in New Zealand White rabbits (1.29 mg/eye) and C57BL/6 mice (50 or 100 μg/eye). Our results demonstrated that the disruption of blood-retinal-barrier, including vascular hyperpermeability, inflammation, and Müller cell dysfunction of fluid clearance, was involved in subretinal edema formation in the model. Bulk RNA-seq and in vitro studies indicated the activation of p38 MAPK signaling pathway in DLAAA models. This DLAAA-induced subretinal edema model can be used for mechanistic studies or drug screening.

Network Pharmacology and Experimental Validation to Explore the Molecular Mechanisms of Compound Huangbai Liquid for the Treatment of Acne

Background

Acne is a highly prevalent skin disease, and inflammation plays an important role. Compound Huangbai Liquid (CHL) is a classical traditional Chinese medicine (TCM) with remarkable clinical therapeutic effects on acne. However, a holistic network pharmacological approach to explain the mechanism of CHL in the treatment of acne has not been explored.

Methods

In this study, active components and action targets of Compound Huangbai Liquid were assessed via BATMAN-TCM. The target genes related to acne were extracted from GeneCards, DisGeNet and OMIM databases. Venn diagrams to predict potential targets for the treatment of acne. Protein-Protein interaction (PPI) analysis was proceeded through String database to obtain the core protein, and the protein interaction network was constructed by Cytoscape 3.9.1. Gene Ontology (Go) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed on Metascape platforms and bioinformatics.com.cn. TCM-compound-target-disease network and disease-target pathway network were constructed using Cytoscape to give the visual result. Finally, the results were further verified by establishing the mouse acne animal model.

Results

This approach identified 165 active compounds, 1117 gene targets, 156 acne-related targets, and 34 potential target proteins for the treatment of acne with CHL. The biological processes were primarily related to cellular response to lipid, response to lipopolysaccharide, and regulation of secretion. The CHL was significantly associated with ten pathways including the Chagas disease and pathways in cancer. Animal experiments showed that CHL could significantly alleviate the levels of inflammatory factors and TLR4/NF-κB/p38 MAPK signaling pathway in acne.

Conclusion

This study revealed the multiple active components, multiple targets, and multiple pathways of CHL in the treatment of acne, which provided a new perspective for the study of the mechanism of traditional Chinese medicine in the treatment of acne.

Vitreous humor proteome: unraveling the molecular mechanisms underlying proliferative and neovascular vitreoretinal diseases

Proliferative diabetic retinopathy (PDR), proliferative vitreoretinopathy (PVR), and neovascular age-related macular degeneration (nAMD) are among the leading causes of blindness. Due to the multifactorial nature of these vitreoretinal diseases, omics approaches are essential for a deeper understanding of the pathophysiologic processes underlying the evolution to a proliferative or neovascular etiology, in which patients suffer from an abrupt loss of vision. For many years, it was thought that the function of the vitreous was merely structural, supporting and protecting the surrounding ocular tissues. Proteomics studies proved that vitreous is more complex and biologically active than initially thought, and its changes reflect the physiological and pathological state of the eye. The vitreous is the scenario of a complex interplay between inflammation, fibrosis, oxidative stress, neurodegeneration, and extracellular matrix remodeling. Vitreous proteome not only reflects the pathological events that occur in the retina, but the changes in the vitreous itself play a central role in the onset and progression of vitreoretinal diseases. Therefore, this review offers an overview of the studies on the vitreous proteome that could help to elucidate some of the pathological mechanisms underlying proliferative and/or neovascular vitreoretinal diseases and to find new potential pharmaceutical targets.

MicroRNA-150 (miR-150) and Diabetic Retinopathy: Is miR-150 Only a Biomarker or Does It Contribute to Disease Progression?

Diabetic retinopathy (DR) is a chronic disease associated with diabetes mellitus and is a leading cause of visual impairment among the working population in the US. Clinically, DR has been diagnosed and treated as a vascular complication, but it adversely impacts both neural retina and retinal vasculature. Degeneration of retinal neurons and microvasculature manifests in the diabetic retina and early stages of DR. Retinal photoreceptors undergo apoptosis shortly after the onset of diabetes, which contributes to the retinal dysfunction and microvascular complications leading to vision impairment. Chronic inflammation is a hallmark of diabetes and a contributor to cell apoptosis, and retinal photoreceptors are a major source of intraocular inflammation that contributes to vascular abnormalities in diabetes. As the levels of microRNAs (miRs) are changed in the plasma and vitreous of diabetic patients, miRs have been suggested as biomarkers to determine the progression of diabetic ocular diseases, including DR. However, few miRs have been thoroughly investigated as contributors to the pathogenesis of DR. Among these miRs, miR-150 is downregulated in diabetic patients and is an endogenous suppressor of inflammation, apoptosis, and pathological angiogenesis. In this review, how miR-150 and its downstream targets contribute to diabetes-associated retinal degeneration and pathological angiogenesis in DR are discussed. Currently, there is no effective treatment to stop or reverse diabetes-caused neural and vascular degeneration in the retina. Understanding the molecular mechanism of the pathogenesis of DR may shed light for the future development of more effective treatments for DR and other diabetes-associated ocular diseases.

Vitamin D3 preserves blood retinal barrier integrity in an in vitro model of diabetic retinopathy

The impairment of the blood retinal barrier (BRB) represents one of the main features of diabetic retinopathy, a secondary microvascular complication of diabetes. Hyperglycemia is a triggering factor of vascular cells damage in diabetic retinopathy. The aim of this study was to assess the effects of vitamin D₃ on BRB protection, and to investigate its regulatory role on inflammatory pathways. We challenged human retinal endothelial cells with high glucose (HG) levels. We found that vitamin D₃ attenuates cell damage elicited by HG, maintaining cell viability and reducing the expression of inflammatory cytokines such as IL-1β and ICAM-1. Furthermore, we showed that vitamin D₃ preserved the BRB integrity as demonstrated by trans-endothelial electrical resistance, permeability assay, and cell junction morphology and quantification (ZO-1 and VE-cadherin). In conclusion this in vitro study provided new insights on the retinal protective role of vitamin D₃, particularly as regard as the early phase of diabetic retinopathy, characterized by BRB breakdown and inflammation.

A novel role of Nano selenium and sildenafil on streptozotocin-induced diabetic nephropathy in rats by modulation of inflammatory, oxidative, and apoptotic pathways

AIMS

The present study aimed to investigate the effect of nano selenium, sildenafil, and their combination on inflammation, oxidative stress, and apoptosis in streptozotocin-induced diabetic nephropathy in rats. Herein, a new anti-inflammatory pathway for sildenafil as a high-mobility group box (HMGB1) inhibitor was proposed using the molecular docking technique.

MATERIALS AND METHODS

Rats were divided into 7 groups: normal control, control nano selenium, control sildenafil, control diabetic, diabetic+ nano selenium, diabetic+ sildenafil, diabetic+ nano selenium+ sildenafil. The effects of drugs were evaluated by measuring serum urea, creatinine, lactate dehydrogenase (LDH), levels of tumor necrosis factor-alpha (TNF-α), Interleukin 1 beta (IL-1β), HMGB1, receptor advanced glycation end product (RAGE), malondialdehyde (MDA), thioredoxin reductase (TrxR) by biochemical assays, nuclear factor-kappa b (NF-κB), toll-like receptor (TLR4) by immunohistochemistry, gene expressions of caspase 3 and monocyte chemoattractant protein (MCP-1) besides histopathological investigations of renal cells.

KEY FINDINGS

Results showed beneficial effects of 8 weeks of treatment by nano selenium and sildenafil supported by improvement in kidney function, histopathological changes, and reduction in all of these parameters. These results supported molecular docking that indicated sildenafil had a high binding score and interactions with the HMGB1 receptor.

SIGNIFICANCE

The current study demonstrated a renoprotective effect of nano‑selenium and sildenafil by interfering at multiple pathways, especially the HMGB1/NF-κB signaling pathway.

A Review of Intraocular Biomolecules in Retinal Vein Occlusion: Toward Potential Biomarkers for Companion Diagnostics

Retinal vein occlusion (RVO) is one of the most common retinal vascular diseases. The pathogenesis of RVO is multifactorial and involves a complex interplay among a variety of vascular and inflammatory mediators. Many cytokines, chemokines, growth factors, and cell adhesion molecules have been reported to be implicated. Treatments for RVO are directed at the management of underlying risk factors and vision-threatening complications, including macula edema (ME) and neovascularization. Intravitreal anti-VEGF agents are currently considered as the first-line treatment for ME secondary to RVO (RVO-ME), but a substantial proportion of patients responded insufficiently to anti-VEGF agents. Since RVO-ME refractory to anti-VEGF agents generally responds to corticosteroids and its visual outcome is negatively correlated to disease duration, prediction of treatment response at baseline in RVO-ME may significantly improve both cost-effectiveness and visual prognosis. Several bioactive molecules in the aqueous humor were found to be associated with disease status in RVO. This review aims to present a comprehensive review of intraocular biomolecules reported in RVO, including VEGF, IL-6, IL-8, MCP-1, sICAM-1, IL-12, IL-13, sVEGFR-1, sVEGFR-2, PDGF-AA, etc., highlighting their association with disease severity and/or phenotype, and their potential roles in prognostic prediction and treatment selection. Some of these molecules may serve as biomarkers for aqueous humor-based companion diagnostics for the treatment of RVO in the future.

Levosimendan Ameliorates Cardiopulmonary Function but Not Inflammatory Response in a Dual Model of Experimental ARDS

The calcium sensitiser levosimendan, which is used as an inodilator to treat decompensated heart failure, may also exhibit anti-inflammatory properties. We examined whether treatment with levosimendan improves cardiopulmonary function and is substantially beneficial to the inflammatory response in acute respiratory response syndrome (ARDS). Levosimendan was administered intravenously in a new experimental porcine model of ARDS. For comparison, we used milrinone, another well-known inotropic agent. Our results demonstrated that levosimendan intravenously improved hemodynamics and lung function in a porcine ARDS model. Significant beneficial alterations in the inflammatory response and lung injury were not detected.

Regulations of Retinal Inflammation: Focusing on Müller Glia

Retinal inflammation underlies multiple prevalent retinal diseases. While microglia are one of the most studied cell types regarding retinal inflammation, growing evidence shows that Müller glia play critical roles in the regulation of retinal inflammation. Müller glia express various receptors for cytokines and release cytokines to regulate inflammation. Müller glia are part of the blood-retinal barrier and interact with microglia in the inflammatory responses. The unique metabolic features of Müller glia in the retina makes them vital for retinal homeostasis maintenance, regulating retinal inflammation by lipid metabolism, purine metabolism, iron metabolism, trophic factors, and antioxidants. miRNAs in Müller glia regulate inflammatory responses via different mechanisms and potentially regulate retinal regeneration. Novel therapies are explored targeting Müller glia for inflammatory retinal diseases treatment. Here we review new findings regarding the roles of Müller glia in retinal inflammation and discuss the related novel therapies for retinal diseases.

Contribution of Müller Cells in the Diabetic Retinopathy Development: Focus on Oxidative Stress and Inflammation

Diabetic retinopathy is a neurovascular complication of diabetes and the main cause of vision loss in adults. Glial cells have a key role in maintenance of central nervous system homeostasis. In the retina, the predominant element is the Müller cell, a specialized cell with radial morphology that spans all retinal layers and influences the function of the entire retinal circuitry. Müller cells provide metabolic support, regulation of extracellular composition, synaptic activity control, structural organization of the blood–retina barrier, antioxidant activity, and trophic support, among other roles. Therefore, impairments of Müller actions lead to retinal malfunctions. Accordingly, increasing evidence indicates that Müller cells are affected in diabetic retinopathy and may contribute to the severity of the disease. Here, we will survey recently described alterations in Müller cell functions and cellular events that contribute to diabetic retinopathy, especially related to oxidative stress and inflammation. This review sheds light on Müller cells as potential therapeutic targets of this disease.

Based on the Network Pharmacology to Investigate the Mechanism of Qingjie Fuzheng Granules against Colorectal Cancer

Qingjie Fuzheng granules (QFG) exert an anticancer effect against colorectal cancers (CRC). However, the pharmacological molecular mechanisms are still unclear. This study was aimed to establish a simple method to predict targets of QFG against CRC by the network pharmacology strategy. 461 compounds and 1559 targets in QFG were enriched by BATMAN-TCM. 21 of the common targets were obtained by the groups of “Jun,” “Chen,” “Zuo,” and “Shi” medicine in QFG. The enrichment analyses of GO functional terms, KEGG pathway, and OMIM/TTD diseases displayed the targets in the different and complementary effects of four functional medicines in QFG. Then, 613 differential targets for QFG in CRC were identified. GO functional terms and KEGG pathway analyses showed that QFG regulated the inflammatory function and lipid metabolic process. There were also targets that played a role in the binding to the receptors in membranes, in the activation of the transportation signal, and provided pain relief by regulation of the neural related pathways. Next, the protein-protein interaction network was analyzed, and the levels of the predicted targets in CRC primary tumor were explored, and 7 candidate targets of QFG against CRC were obtained. Furthermore, with real-time PCR and enzyme-linked immunosorbent assay (ELISA) analysis, downregulation of dopamine D2 receptor (DRD2) and interleukin-6 (IL-6), and upregulation of interleukin-10 (IL-10) were identified following the treatment of QFG. At last, the survival and prognosis of the potential targets of QFG in CRC patients were analyzed by GenomicScape, and IL-6 was suggested to be an index for the regulation of QFG in CRC. These results might elucidate the possible antitumor mechanism of QFG and highlight the candidate therapeutic targets and the application direction in clinical treatment for QFG.

Treatment with Commelina communis Extract Exerts Anti-inflammatory Effects in Murine Macrophages via Modulation of the Nuclear Factor-κB Pathway

The incidence of severe inflammatory diseases caused by chronic inflammation has increased owing to unprecedented changes brought about by industrialization. In this study, we aimed to assess the effect of treatment of lipopolysaccharide- (LPS-) induced murine macrophages with Commelina communis Linne extract (CCE) on synthesis of nitric oxide (NO), hypersecretion of proinflammatory cytokines, intranuclear transition of the p65 subunit of nuclear factor- (NF-) κB, and degradation of the NF-κB inhibitor IκBα. Notably, CCE treatment did not affect cell viability even at a final concentration of 1.5 mg/mL. At a high concentration of CCE, the LPS-induced high levels of NO, tumor necrosis factor-α, interleukin- (IL-) 1β, and IL-6 were decreased via downregulation of inducible NO synthase and proinflammatory cytokine mRNA expression. Furthermore, phosphorylation of IκBα was significantly decreased upon CCE treatment, and the intranuclear transition of NF-κB p65 triggered by LPS was inhibited at a high concentration of CCE. Polyphenols and flavonoids, secondary metabolites in CCE that regulate the NF-κB pathway, may be responsible for its anti-inflammatory activity. We suggest that CCE has anti-inflammatory effects related to suppression of the NF-κB pathway and can be used to treat chronic inflammation.

Mechanism Assay of Honeysuckle for Heat-Clearing Based on Metabolites and Metabolomics

Nonsteroidal anti-inflammatory drugs (NSAIDs), such as cyclooxygenase (Cox)-1/2 inhibitor, have emerged as potent antipyretics and analgesics. However, few herbs with Cox-1/2 inhibitory activity are commonly used for heat-clearing in China. Although these are known to have antipyretic activity, there is a lack of molecular data supporting their activity. Using the traditional Chinese medicine herb honeysuckle (Hon) as an example, we explored key antipyretic active compounds and their mechanisms of action by assessing their metabolites and metabolomics. Mitogen-activated protein kinase (MAPK) 3 and protein kinase B (AKT) 1 were suggested as key targets regulated primarily by chlorogenic acid (CA) and swertiamarin (SWE). CA and SWE synergistically inhibited the production of interleukin (IL)-1 and IL-6, alleviated generation of prostaglandin E2, and played an antipyretic role equivalent to honeysuckle extract at the same dose contents within 3 h. Collectively, these findings indicated that lipopolysaccharide-induced fever can be countered by CA with SWE synergistically, allowing the substitution of a crude extract of complex composition with active compounds. Our findings demonstrated that, unlike the traditional NSAIDs, the Hon extract showed a remote and indirect mechanism for alleviating fever that depended on the phosphatidylinositol-3-kinase–AKT and MAPK pathways by regulating the principal mediator of inflammation.

Unsuspected Central Vision Decrease from Macular Ganglion Cell Loss after Posterior Segment Surgery

PURPOSE

To describe a novel post-surgical complication of circumscribed macula ganglion cell loss as an apparent cause of unsuspected vision loss following posterior segment surgery.

METHODS

Patients were seen in referral and were evaluated with comprehensive examination to include optical coherence tomography (OCT) and microperimetry.

RESULTS

All 8 patients had a sudden central vision loss following vitrectomy and many patients suspected the central loss was present even before the eye patch was removed on the first postoperative day. Of the 8, 1 had a vitrectomy with no membrane peeling while the remaining 7 had membrane peeling. The mean post-operative visual acuity was 20/200. The mean ganglion cell layer (GCL) volume was 0.69 µm3 in the involved eye and 1.035 µm3 in the fellow eye (P<.001). The global retinal nerve fiber layer (RNFL) thicknesses in the involved and fellow eyes were 81.3 and 90 µm respectively (P = .08). The outer retinal architecture was unremarkable in the involved eyes and did not appear to explain the poor acuity. The GCL volume loss was not necessarily associated with RNFL thicknesses that were in the abnormal range or in optic nerve pallor. Microperimetry showed severe depression of the threshold sensitivities.

CONCLUSION

Severe loss of the macular ganglion cells may occur after vitrectomy and is associated with central vision loss. The diagnosis is made by having a high index of suspicion when examining OCT B-scan images and by evaluating GCL volumes. The frequency of this occurrence is currently unknown.

Proteomic Phenotyping of Stimulated Müller Cells Uncovers Profound Pro-Inflammatory Signaling and Antigen-Presenting Capacity

Müller cells are the main macroglial cells of the retina exerting a wealth of functions to maintain retinal homoeostasis. Upon pathological changes in the retina, they become gliotic with both protective and detrimental consequences. Accumulating data also provide evidence for a pivotal role of Müller cells in the pathogenesis of diabetic retinopathy (DR). While microglial cells, the resident immune cells of the retina are considered as main players in inflammatory processes associated with DR, the implication of activated Müller cells in chronic retinal inflammation remains to be elucidated. In order to assess the signaling capacity of Müller cells and their role in retinal inflammation, we performed in-depth proteomic analysis of Müller cell proteomes and secretomes after stimulation with INFγ, TNFα, IL-4, IL-6, IL-10, VEGF, TGFβ1, TGFβ2 and TGFβ3. We used both, primary porcine Müller cells and the human Müller cell line MIO-M1 for our hypothesis generating approach. Our results point towards an intense signaling capacity of Müller cells, which reacted in a highly discriminating manner upon treatment with different cytokines. Stimulation of Müller cells resulted in a primarily pro-inflammatory phenotype with secretion of cytokines and components of the complement system. Furthermore, we observed evidence for mitochondrial dysfunction, implying oxidative stress after treatment with the various cytokines. Finally, both MIO-M1 cells and primary porcine Müller cells showed several characteristics of atypical antigen-presenting cells, as they are capable of inducing MHC class I and MHC class II with co-stimulatory molecules. In line with this, they express proteins associated with formation and maturation of phagosomes. Thus, our findings underline the importance of Müller cell signaling in the inflamed retina, indicating an active role in chronic retinal inflammation.

Long non-coding RNA (lncRNA) nuclear enriched abundant transcript 1 (NEAT1) promotes the inflammation and apoptosis of otitis media with effusion through targeting microRNA (miR)-495 and activation of p38 MAPK signaling pathway

Long non-coding RNA (lncRNA) plays a vital role in human inflammatory diseases. Our study aimed to investigate the function of lncRNA nuclear-enriched abundant transcript 1 (NEAT1) in otitis media with effusion (OME). The mRNA levels of NEAT1 and miR-495 were measured by RT-qPCR. The protein levels of p38 MAPK were detected by western blot. The levels of inflammatory cytokines were examined by ELISA. CCK-8 and flow cytometry assays were used to evaluate the cell viability and apoptosis, respectively. The interaction between NEAT1 and miR-495 was determined by luciferase reporter and RIP assays. NEAT1 was highly expressed in OME, and silencing of NEAT1 facilitated the cell proliferation and suppressed levels of inflammatory cytokines and cell apoptosis in LPS-induced HMEECs. Moreover, miR-495 was confirmed as a downstream target of NEAT1. Functional assays revealed that NEAT1 promoted the OME by targeting miR-495. It was further demonstrated that NEAT1 could activate the p38 MAPK signaling pathway by regulating miR-495, and the p38 MAPK inhibitor restored the effects of NEAT1 overexpression on the inflammation levels, cell proliferation, and apoptosis. Our study revealed that lncRNA NEAT1 served as a ceRNA to activate p38 MAPK signaling by targeting miR-495 in OME, which may offer a new target for OME treatment.

Cyanidin-3-o-glucoside (C3G) inhibits vascular leakage regulated by microglial activation in early diabetic retinopathy and neovascularization in advanced diabetic retinopathy

Cyanidin-3-O-glucoside (C3G) is a kind of anthocyanin which shows strong anti-inflammation, anti-tumor and anti-oxidant properties. This paper was designed to explore the potential effects of C3G on diabetic retinopathy (DR). C57BL/6 mice were administrated with streptozotocin (STZ) or vehicle control for the establishment of diabetic models. To simulate hyperglycemia and hypoxia, D-glucose (30 mM) and CoCl₂ (200 μm/l) were utilized to treat HRECs, respectively. The migration, invasion, inflammation and tube formation abilities of cells were evaluated with the adoption of wound healing, transwell, ELISA and tube formation assays, respectively. Besides, immunofluorescence staining was utilized to detect proliferation and retinal vessels. Evans blue permeation assay were performed to evaluate the vascular leakage in DR mice. Moreover, western blot and qPCR were used to quantify the mRNA and protein expressions of ionized calcium-binding adapter molecule (Iba)-1 and tight junction proteins. Results showed that C3G alleviated the inflammation, microglial activation and angiogenesis in DR mice. Moreover, the proliferation and inflammation of BV2 cells induced by high glucose (HG) were suppressed by C3G. Evans blue permeation assay demonstrated the potency of C3G in attenuating vascular leakage. In addition, C3G suppressed the migration, invasion and angiogenesis of human retinal endothelial cells (HRECs) DR model in vitro.By confirming the role of C3G in inhibiting vascular leakage regulated by microglia activation in early DR and angiogenesis in advanced DR, this study pointed out the potential of C3G as a therapeutic drug for DR management.

Isorhamnetin attenuates high-fat and high-fructose diet induced cognitive impairments and neuroinflammation by mediating MAPK and NFκB signaling pathways

Isorhamnetin (ISO), a flavonoid compound isolated from sea-buckthorn (Hippophae rhamnoides L.) fruit, has anti-inflammatory effects. However, the effects of ISO on neuroinflammation and cognitive function are still unclear. The purpose of this study was to evaluate the protective effect of ISO on cognitive impairment in obese mice induced by a high-fat and high fructose diet (HFFD). It has been found that oral administration of ISO (0.03% w/w and 0.06% w/w) for 14 weeks significantly reduced the body weight, food intake, liver weight, liver lipid level, and serum lipid level of HFFD-fed mice. ISO can also significantly prevent HFFD-induced neuronal working, spatial, and long-term memory impairment. Notably, the ISO treatment activated the CREB/BDNF pathway and increased neurotrophic factors in the brains of mice. Furthermore, ISO inhibited HFFD-induced microglial overactivation and down-regulated inflammatory cytokines in both serum and the brain. It can also inhibit the expression of p-JNK, p-p38, and p-NFκB protein in the mouse brain. In conclusion, these results indicated that ISO mitigated HFFD-induced cognitive impairments by inhibiting the MAPK and NFκB signaling pathways, suggesting that ISO might be a plausible nutritional intervention for metabolic syndrome-related cognitive complications.

Selective activation of pro-anti-IL-1β antibody enhances specificity for autoinflammatory disorder therapy

Canakinumab is a fully human monoclonal antibody that specifically neutralizes human interleukin (IL)-1β and has been approved by the US Food and Drug Administration for treating different types of autoinflammatory disorders such as cryopyrin-associated periodic syndrome, tumor necrosis factor receptor-associated periodic syndrome and systemic juvenile idiopathic arthritis. However, long-term systemic neutralization of IL-1β by Canakinumab may cause severe adverse events such as serious upper respiratory tract infections and inflammation, thereby decreasing the quality of life of patients. Here, we used an IgG1 hinge as an Ab lock to cover the IL-1β-binding site of Canakinumab by linking with matrix metalloprotease 9 (MMP-9) substrate to generate pro-Canakinumab that can be specifically activated in the inflamed regions in autoinflammatory diseases to enhance the selectivity and safety of treatment. The Ab lock significantly inhibited the IL-1β-binding by 68-fold compared with Canakinumab, and MMP-9 completely restored the IL-1β neutralizing ability of pro-Canakinumab within 60 min and blocked IL-1β-downstream signaling and IL-1β-regulated genes (i.e., IL-6). It is expected that MMP-9 cleavable and efficient Ab lock will be able to significantly enhance the selective reaction of Canakinumab at the disease site and reduce the on-target toxicities of Canakinumab during systemic circulation, thereby showing potential for development to improve the safety and quality of life of patients with autoinflammatory disorders in the future.

African pygmy hedgehog adenovirus: Virus replication, virus-induced cytopathogenesis and activation of mitogen-activated protein kinase signaling pathways in infected MDCK cells

We examined several aspects of African hedgehog adenovirus (AhAdv-1) that was isolated from an African pygmy hedgehog, including: replication kinetics of, virus-induced cytopathic effect (CPE), activation status of mitogen-activated protein kinase (MAPK) signaling pathways, and possible roles of these signaling pathways in virus replication and virus-induced CPE in MDCK cells. AhAdv-1 efficiently replicated and induced CPE in infected cells and caused accumulation of cleaved caspase-3 at 24 h post-infection (p.i.), suggesting apoptosis induction. Analysis of several intracellular signal transduction pathways, which are involved in apoptosis, showed activation of p38 MAPK, Akt and ERK1/2 pathways at 3 h p.i., and upregulation of phosphorylated SAPK/JNK at 24 h p.i. Although p38 MAPK inhibitor and SAPK/JNK inhibitor suppressed activation of the respective pathways in infected cells, they did not inhibit virus-induced CPE. Treatment of infected cells with inhibitor of the Akt pathway, the p38 pathway, the SAPK/JNK pathway or the ERK pathway revealed that inhibitors of p38 pathway inhibited viral replication by real-time PCR and TCID₅₀ assay in infected MDCK cells, suggesting that AhAdv-1 uses p38 pathway for multiplication in infected cells.

Identification of the Key Role of NF-κB Signaling Pathway in the Treatment of Osteoarthritis With Bushen Zhuangjin Decoction, a Verification Based on Network Pharmacology Approach

This study aimed to identify whether the NF-κB signaling pathway plays a key role in the treatment of osteoarthritis (OA) with Bushen Zhuangjin Decoction (BZD) based on a typical network pharmacology approach (NPA). Four sequential experiments were performed: 1) conventional high-performance liquid chromatography (HPLC), 2) preliminary observation of the therapeutic effects of BZD, 3) NPA using three OA-related gene expression profiles, and 4) verification of the key pathway identified by NPA. Only one HPLC-verified compound (paeoniflorin) was identified from the candidate compounds discovered by NPA. The genes verified in the preliminary observation were also identified by NPA. NPA identified a key role for the NF-κB signaling pathway in the treatment of OA with BZD, which was confirmed by conventional western blot analysis. This study identified and verified NF-κB signaling pathway as the most important inflammatory signaling pathway involved in the mechanisms of BZD for treating OA by comparing the NPA results with conventional methods. Our findings also indicate that NPA is a powerful tool for exploring the molecular targets of complex herbal formulations, such as BZD.

Relationship between the higher inflammatory cytokines level in the aqueous humor of Fuchs uveitis syndrome and the presence of cataract

BACKGROUND

This study aims to compare the levels of intraocular cytokines between Fuchs uveitis syndrome (FUS) eyes and the senile cataract eyes. The association between inflammatory cytokine levels and cataract severity in FUS is evaluated to find the possible mechanism of cataract in FUS eyes.

METHODS

A retrospective study of 28 eyes with FUS was performed. Auxiliary examinations were performed, including ophthalmic examinations, laser flare-cell photometry, and levels of inflammatory cytokines in the aqueous humor were measured. The control group included 25 eyes with senile cataract. Data on the aqueous humor inflammatory cytokines were compared between the two groups. The association between the aqueous humor cytokine levels and severity of posterior subcapsular cataract was assessed.

RESULTS

There were 28 eyes with FUS in 27 patients. Unilateral involvement was noted in 26 patients (96.30%). Stellate keratic precipitates (KPs) were noted in 16 eyes (57.14%). Heterochromia was observed in 21.43% of affected eyes. Posterior subcapsular cataract (PSC) was observed in 16 of the 28 eyes. Eyes with FUS had significantly higher aqueous humor (AH) cytokine levels (VEGF, bFGF, IL-6, IL-8 and IL-10) compared with the control eyes (P < 0.05). There was a statistically significant positive correlation between the severity of cataract and IL-6 and IL-8 levels in the AH (τ = 0.664 and 0.634, respectively; P = 0.001, P = 0.002, respectively).

CONCLUSIONS

Expression of VEGF, bFGF, IL-6, IL-8 and IL-10 in the AH of FUS patients was significantly higher than in senile cataract eyes, and the aqueous humor levels of IL-6 and IL-8 were significantly positively associated with the severity of posterior subcapsular cataract. Our results imply that an inflammation mechanism may be involved in the early development of cataract in FUS.

VEGF-Independent Activation of Müller Cells by the Vitreous from Proliferative Diabetic Retinopathy Patients

Proliferative diabetic retinopathy (PDR), a major complication of diabetes mellitus, results from an inflammation-sustained interplay among endothelial cells, neurons, and glia. Even though anti-vascular endothelial growth factor (VEGF) interventions represent the therapeutic option for PDR, they are only partially efficacious. In PDR, Müller cells undergo reactive gliosis, produce inflammatory cytokines/chemokines, and contribute to scar formation and retinal neovascularization. However, the impact of anti-VEGF interventions on Müller cell activation has not been fully elucidated. Here, we show that treatment of MIO-M1 Müller cells with vitreous obtained from PDR patients stimulates cell proliferation and motility, and activates various intracellular signaling pathways. This leads to cytokine/chemokine upregulation, a response that was not mimicked by treatment with recombinant VEGF nor inhibited by the anti-VEGF drug ranibizumab. In contrast, fibroblast growth factor-2 (FGF2) induced a significant overexpression of various cytokines/chemokines in MIO-M1 cells. In addition, the FGF receptor tyrosine kinase inhibitor BGJ398, the pan-FGF trap NSC12, the heparin-binding protein antagonist N-tert-butyloxycarbonyl-Phe-Leu-Phe-Leu-Phe Boc2, and the anti-inflammatory hydrocortisone all inhibited Müller cell activation mediated by PDR vitreous. These findings point to a role for various modulators beside VEGF in Müller cell activation and pave the way to the search for novel therapeutic strategies in PDR.

Bone Morphogenetic Protein-2 Induces Non-Canonical Inflammatory and Oxidative Pathways in Human Retinal Endothelial Cells

The mechanisms of diabetic retinopathy (DR), are not yet fully understood. We previously demonstrated an upregulation of retinal bone morphogenetic protein-2 (BMP2) in experimental diabetes and in retinas of diabetic human subjects. The purpose of current study was to investigate the role of non-canonical inflammatory pathway in BMP2-induced retinal endothelial cell (REC) barrier dysfunction. For this purpose, we used RT-PCR and western blotting to evaluate the levels of BMP2 signaling components (BMP2, BMP4, BMP receptors), VEGF, phosphorylated p38 MAPK and NFκB, and oxidative stress markers in cultured human retinal endothelial cells (HRECs) subjected to BMP2 (50ng/ml) for up to 24 h. Also, effect of high glucose (HG, 30mM D-glucose) on the expression of BMP2 and its downstream genes was examined in HRECs. H2-DCF is a fluorogenic dye that measures the levels of cellular reactive oxygen species (ROS) was used to measure the pro-oxidative effect of BMP2. Moreover, we evaluated the effect of inhibiting p38 and VEGF signaling on BMP2-induced HRECs barrier dysfunction by measuring the trans-endothelial cell electrical resistance (TER) using electric cell-substrate impedance sensing (ECIS). We also tested the effect of HG on the integrity of HRECs barrier in the presence or absence of inhibitors of BMP2 signaling. Our data reveals that BMP2 and high glucose upregulates BMP components of the BMP signaling pathway (SMAD effectors, BMP receptors, and TGFβ ligand itself) and induces phosphorylation of p38 MAPK and NFκB with nuclear translocation of NFκB. Inhibition of p38 or NFκB attenuated BMP2-induced VEGF expression and barrier dysfunction in HRECs. Also, inhibition of VEGFR2 attenuated BMP2-induced barrier dysfunction. Moreover, BMP2 induces generation of ROS and endothelial nitric oxide synthase (eNOS) expression and activity in HRECs. Finally, HG upregulated BMP2 and its downstream genes (SMAD, BMP4, ALKs, and TGF-β) in HRECs and BMP2 inhibitors attenuated HG-induced HRECs barrier dysfunction. Our results suggest that in addition to the regular canonical SMAD signaling BMP2 induces non-canonical inflammatory pathway in HRECs via activation of p38/NFκB pathway that causes the upregulation of VEGF and the disruption of HRECs. Inhibition of BMP2 signaling is a potential therapeutic intervention to preserve endothelial cell barrier function in DR.

The innate immune system in diabetic retinopathy

The prevalence of diabetes has been rising steadily in the past half-century, along with the burden of its associated complications, including diabetic retinopathy (DR). DR is currently the most common cause of vision loss in working-age adults in the United States. Historically, DR has been diagnosed and classified clinically based on what is visible by fundoscopy; that is vasculature alterations. However, recent technological advances have confirmed pathology of the neuroretina prior to any detectable vascular changes. These, coupled with molecular studies, and the positive impact of anti-inflammatory therapeutics in DR patients have highlighted the central involvement of the innate immune system. Reminiscent of the systemic impact of diabetes, immune dysregulation has become increasingly identified as a key element of the pathophysiology of DR by interfering with normal homeostatic systems. This review uses the growing body of literature across various model systems to demonstrate the clear involvement of all three pillars of the immune system: immune-competent cells, mediators, and the complement system. It also demonstrates how the relative contribution of each of these requires more extensive analysis, including in human tissues over the continuum of disease progression. Finally, although this review demonstrates how the complex interactions of the immune system pose many more questions than answers, the intimately connected nature of the three pillars of the immune system may also point to possible new targets to reverse or even halt reverse retinopathy.

Vaccinia Virus Protein B18R: Influence on mRNA Immunogenicity and Translation upon Non-Viral Delivery in Different Ocular Cell Types

In the last few years, interest has grown in the use of nucleic acids as an ocular therapy for retinal genetic diseases. Recently, our research group has demonstrated that mRNA delivery could result in effective protein expression in ocular cells following subretinal injection. Yet, although mRNA therapy comes with many advantages, its immunogenicity resulting in hampered mRNA translation delays development to the clinic. Therefore, several research groups investigate possible strategies to reduce this innate immunity. In this study, we focus on B18R, an immune inhibitor to suppress the mRNA-induced innate immune responses in two ocular cell types. We made use of retinal pigment epithelial (RPE) cells and Müller cells both as immortalized cell lines and primary bovine cells. When cells were co-incubated with both B18R and mRNA-MessengerMAX lipoplexes we observed an increase in transfection efficiency accompanied by a decrease in interferon-β production, except for the Müller cells. Moreover, uptake efficiency and cell viability were not hampered. Taken together, we showed that the effect of B18R is cell type-dependent but remains a possible strategy to improve mRNA translation in RPE cells.

Berberine suppresses bone loss and inflammation in ligature-induced periodontitis through promotion of the G protein-coupled estrogen receptor-mediated inactivation of the p38MAPK/NF-κB pathway

OBJECTIVE

This study aimed to explore the protective actions of berberine on inflammation, and alveolar bone loss in ligature-induced periodontitis, as well as its mechanism of action METHODS: Micro-computed tomography was conducted to analyze the alveolar bone loss, and hematoxylin and eosin staining was carried out to observe the histopathological changes and inflammation status. Furthermore, enzyme linked immunosorbent assay (ELISA) was conducted to evaluate the levels of TNF-α, IL-1β, and IL-10, as well as western blots to determine the levels of GPR30 and the activity of the p38MAPK/NF-κB pathway.

RESULTS

Berberine distinctly suppressed alveolar bone loss and inflammation in rats exposed to ligature-induced periodontitis. As well as this, berberine significantly decreased the levels of phosphorylated p38MAPK and phosphorylated NF-κB 65 through upregulating the GRP30 protein levels, this protective effects of berberine were reversed by injection of G15, along with the upregulated activity of the p38MAPK/NF-κB pathway in rats with periodontitis.

CONCLUSIONS

Berberine had a clear inhibitory effect on alveolar bone loss and inflammation in rats exposed to ligature-induced periodontitis, and its putative mechanism of action was attributed to the downregulation of the activity of the P38MAPK/NF-κB pathway, mediated by the G Protein-coupled estrogen receptor.

Monomeric C-reactive protein affects cell injury and apoptosis through activation of p38 mitogen-activated protein kinase in human coronary artery endothelial cells

C-reactive protein (CRP) is an important predictor of cardiovascular events and plays a role in vascular inflammation and vessel damage. The aim of this study was to investigate the effect of pentameric CRP (pCRP) and monomeric CRP (mCRP) on the production of atherosclerosis-re-lated factors in cultured human coronary artery endothelial cells (HCAECs). HCAECs were treated with pCRP, mCRP, p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580, or transfected with p38 MAPK siRNA. Western blotting was performed to detect the expression of vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2), intercellular adhesion molecule-2 (ICAM-2) and vascular cell adhe-sion molecule-1 (VCAM-1). Proliferation, damage, and apoptosis of HCAECs were examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, lactate dehydrogenase (LDH), and flow cytometry, respectively. mCRP suppressed VEGF and COX-2 expression and enhanced ICAM-2 and VCAM-1 expression in HCAECs, in both dose-dependent and time-dependent manner. Except at 100 μg/ml concen-tration and 20-hour or 24-hour incubation, pCRP had no apparent effects. mCRP but not pCRP induced HCAEC injury and phosphorylation of p38 MAPK, and the inhibitor SB203580 reversed the effects of mCRP. mCRP promotes injury and apoptosis of HCAECs through a p38 MAPK-dependent mechanism, which provides a new therapy for the injury of HCAECs in atherosclerosis.

Adenovirus 7 Induces Interlukin-6 Expression in Human Airway Epithelial Cells via p38/NF-κB Signaling Pathway

Human Adenovirus (AdV) infection is very common and usually has a significant impact on children. AdV-induced inflammation is believed to be one of the main causes of severe symptoms. However, an inflammatory response profile in the airway in AdV-infected children is still lacking, and the mechanism underlying AdV-induced inflammation in the airway is also poorly understood. In the current study, we determined the expression of a panel of inflammation cytokines in the airway samples from AdV 7 infected children and further investigated the molecular mechanism underlying AdV 7-induced cytokine expression. Our results showed that eight out of 13 tested inflammatory cytokines were significantly increased in nasal washes of AdV 7-infected children comparing to healthy control, with IL-6 showing the highest enhancement. AdV 7 infection of bronchial epithelial cell line and primary airway epithelial cells confirmed that AdV 7 increased IL-6 mRNA and protein expression in an infection dose-dependent manner. Promoter analysis revealed that AdV 7 infection transactivated IL-6 promoter and a NF-κB binding site in IL-6 promoter was involved in the transactivation. Further analysis showed that upon AdV 7 infection, NF-κB p65 was phosphorylated and translocated into nucleus and bound onto IL-6 promoter. Signaling pathway analysis revealed that p38/NF-κB pathway was involved in AdV 7 infection induced IL-6 elevation. Taken together, our study shows that AdV 7 infection triggers the expression of a range of inflammatory cytokines including IL-6 in the airway of infected children, and AdV 7 enhances IL-6 expression by transactivating IL-6 promoter via p38/NF-κB signaling pathway. Findings of our current study have provided more information toward a better understanding of AdV-induced airway inflammation, which might also benefit the development of intervention strategies.

Effect of Ultrafine Powderization and Solid Dispersion Formation via Hot-Melt Extrusion on Antioxidant, Anti-Inflammatory, and the Human Kv1.3 Channel Inhibitory Activities of Angelica gigas Nakai

Angelica gigas Nakai (AGN) was first processed by ultrafine grinding technology and hot-melt extrusion (HME). The potential antioxidant and anti-inflammatory activities of AGN with a different process were compared, and the effect on the human Kv1.3 potassium channel was detected. The process of ultrafine powderization on AGN significantly increased the total phenolic and flavonoid contents, antioxidant activity, and DNA damage protective effect. On the contrary, AGN solid dispersion (AGN-SD) based on Soluplus^® showed the highest inhibitory effect on NO production and the human Kv1.3 channel. In addition, AGN-SD inhibited the production of prostaglandin E2 and intracellular reactive oxygen species and the mRNA expression of inducible nitric oxide synthase, cyclooxygenase-2, interleukin 1β, and interleukin 6. Taken together, these results suggest that ultrafine powderization and solid dispersion formation via HME can significantly improve the biological activities of AGN. The results also suggested that ultrafine powderization and HME may be developed and applied in the pharmaceutical industry.

Emerging corticosteroid delivery platforms for treatment of diabetic macular edema

INTRODUCTION

Diabetic macular edema (DME) is a leading cause of vision impairment. Low-grade inflammation is thought to play a critical role in its pathogenesis. Although vascular endothelial growth factor inhibitors are used first-line, not all eyes with DME respond optimally and may respond better to corticosteroids. Currently corticosteroids for DME are given intravitreally and require regular monitoring. There is an unmet need for longer lasting therapies and/or effective noninvasive therapies such as those given via oral or topical routes.

AREAS COVERED

This review discusses emerging corticosteroid delivery platforms for DME treatment. A literature search of investigational novel therapeutic steroid delivery platform in DME was conducted. Results are presented from preclinical, phase 1,2 & 3 clinical trials of various drug delivery systems using new technologies such as Solubilizing Nanoparticle technology, Mucus Penetrating Particles technology and Particle Replication In Non-wetting Templates. These new platforms aim to deliver corticosteroids effectively via topical, episcleral, subtenon, oral, and intravitreal routes.

EXPERT OPINION

These novel drug delivery platforms have the potential to lead to noninvasive or minimally invasive therapies and may overcome the shortcomings of current pharmacotherapy. However, larger comparative trials are needed for these agents to be added to the current armamentarium in DME management.

PG545 alleviates diabetic retinopathy by promoting retinal Müller cell autophagy to inhibit the inflammatory response

Diabetic retinopathy (DR), a major cause of blindness in working-age people, is attributed to the inflammatory response of retinal Müller cells (RMCs). The heparanase inhibitor PG545 plays proautophagic and anti-inflammatory roles. Intraperitoneal injection of PG545 at a dose of 20 mg/kg/d clearly reduced diabetes-induced body weight changes and fasting blood glucose levels in mice. PG545 also mitigated the reduction in retinal thickness and the formation of microaneurysms by promoting autophagy to inhibit the inflammatory response. In vitro, PG545 stimulated autophagy to downregulate the inflammatory response in high glucose-induced primary adult mouse RMCs. These data suggest that PG545 mitigates DR by promoting RMC autophagy to inhibit the inflammatory response.

Colchicine prevents atrial fibrillation promotion by inhibiting IL-1β-induced IL-6 release and atrial fibrosis in the rat sterile pericarditis model

A few clinical trials have recently reported the potential effect of colchicine in preventing post-operative atrial fibrillation (POAF) and early atrial fibrillation (AF) recurrence after catheter pulmonary vein isolation. However, the molecular mechanisms through which colchicine inhibits AF remain unclear. We aim to assess the anti-AF effect of colchicine in the rat sterile pericarditis (SP) model and to investigate its molecular mechanisms. SP was induced in Sprague-Dawley rats by the epicardial application of sterile talc. Treatment with colchicine or vehicle began 1 d before pericardiotomy. AF was induced by transesophageal burst pacing on day 3 after surgery. Treatment with colchicine reduced the duration of AF and the probability of induction of AF in SP rats. The dose of 0.5 mg kg^-1·day^-1 had the best effect. Such treatment also reduced neutrophil infiltration, the mRNA expression of IL-6, TGF-β, and TNF-α, atrial fibrosis, fibrosis related genes, and signal molecules (STAT3, P38, and AKT). Meanwhile, the release of IL-1β (4-24 h) and IL-6 (4-72 h) in atria after surgery was significantly inhibited by colchicine. In cultured rat cardiac fibroblasts, colchicine treatment inhibited IL-1β-induced expression of IL-6, which was accompanied by significantly decreased phosphorylation of P38, AKT, JNK, and NFκB. Interestingly, the supplementation of IL-6 abolished the anti-AF effect of colchicine in SP rats. Colchicine prevents AF in SP rats through the inhibition of IL-1β-induced IL-6 release and subsequent atrial fibrosis. However, further studies are required to investigate whether colchicine inhibits POAF through other mechanisms.

Inflammatory and Fibrogenic Factors in Proliferative Vitreoretinopathy Development

Purpose

Proliferative vitreoretinopathy (PVR) occurs in 5%-10% of rhegmatogenous retinal detachment cases and is the principle cause for failure of retinal reattachment surgery. Although there are a number of surgical adjunctive agents available for preventing the development of PVR, all have limited efficacy. Discovering predictive molecular biomarkers to determine the probability of PVR development after retinal reattachment surgery will allow better patient stratification for more targeted drug evaluations.

Methods

Narrative literature review.

Results

We provide a summary of the inflammatory and fibrogenic factors found in ocular fluid samples during the development of retinal detachment and PVR and discuss their possible use as molecular PVR predictive biomarkers.

Conclusions

Studies monitoring the levels of the above factors have found that few if any have predictive biomarker value, suggesting that widening the phenotype of potential factors and a combinatorial approach are required to determine predictive biomarkers for PVR.

Translational Relevance

The identification of relevant biomarkers relies on an understanding of disease signaling pathways derived from basic science research. We discuss the extent to which those molecules identified as biomarkers and predictors of PVR relate to disease pathogenesis and could function as useful disease predictors. (http://www.umin.ac.jp/ctr/ number, UMIN000005604).

Effects of Coconut Water on Retina in Diabetic Rats

Coconut water (CW) is a natural aseptic nutritious beverage, containing several biologically active compounds. This study aimed to determine the antiretinopathy effects of CW on diabetic Sprague Dawley (SD) rats using streptozotocin (STZ) and explore its potential mechanism. After allowing the rats to acclimatize for 7 days, 48 healthy adult male SD rats were selected and randomly divided into 4 groups, involving control (Ctrl), diabetic rats (DM), diabetic rats treated with CW (DM-CW), and diabetic rats treated with glibenclamide (DM-Gli). The diabetic models were established by an intraperitoneal injection of STZ (60 mg/kg). The Ctrl group was injected with an equal volume of sodium citrate solution. The experiment was totally conducted during 20 weeks, and then, all rats were sacrificed. The serum levels of superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) were measured; additionally, the activities of interleukin-6 (IL-6) and intercellular adhesion molecule-1 (ICAM-1) in the retina were investigated using biochemical assays. Hematoxylin and eosin (H&E) staining was performed to observe pathological changes of retinal tissues. In presence of treatment with CW, serum level of MDA was decreased, while serum levels of SOD and GSH-Px were increased; besides, the activities of IL-6 and ICAM-1 in the retina were reduced compared with the DM group. The antiretinopathy feature of CW was confirmed by the increased number of neurons in the ganglion cell layer (GCL), total retina thickness (TRT), and thickness of the retinal nuclear layer (RNL) in diabetic rats. CW can be protective against diabetic retinopathy (DR), and its effects are comparable to Gli. The possible underlying mechanism may be partly explained by decreasing oxidative stress and anti-inflammatory activities in the retina. However, further research should be conducted to reveal the exact mechanism.

Endothelial Dysfunction in Diabetic Retinopathy

Diabetic retinopathy (DR) is a diabetic complication which affects retinal function and results in severe loss of vision and relevant retinal diseases. Retinal vascular dysfunction caused by multifactors, such as advanced glycosylation end products and receptors, pro-inflammatory cytokines and chemokines, proliferator-activated receptor-γ disruption, growth factors, oxidative stress, and microRNA. These factors promote retinal endothelial dysfunction, which results in the development of DR. In this review, we summarize the contributors in the pathophysiology of DR for a better understanding of the molecular and cellular mechanism in the development of DR with a special emphasis on retinal endothelial dysfunction.

The protective effects of lycopus lucidus turcz in diabetic retinopathy and its possible mechanisms

The aim of the present study was to investigate the effect of Lycopus lucidus Turcz (LT) on diabetic retinopathy (DR) and its underlying mechanisms. SD rats and human retinal microvascular endothelial cells (HRECs) were applied for establishment DR model. HE and TUNEL staining were used to evaluate the pathological changes and apoptosis of retinal ganglion cells. Additionally, retinal vessels were detected by immunofluorescence staining with CD31 and VEGF. The function of BRB was observed using Evans blue. Moreover, the oxidative stress, inflammation and angiogenesis associated factors were measured respectively. The expression of p38-MAPK/NF-κB signalling proteins were detected by Western blot. The results demonstrated that pathological changes and retinal optic disc cells apoptosis in retinas of diabetic rats, both of which were reduced in the LT-treated group. And LT treatment attenuated the levels of oxidative stress, inflammation and angiogenesis factors. Importantly, the expression levels of p-p38, p-ERK, p-JNK and NF-κB were decreased. After treatment with TNF-α combined with LT, the levels of inflammatory factors were decreased but higher than the negative control. Taken together, the results suggested that LT treatment is of therapeutic benefit by ameliorating oxidative stress, inflammation and angiogenesis of DR via p38-MAPK/NF-κB signaling pathway.

The peroxisome proliferator-activated receptor-β/δ antagonist GSK0660 mitigates retinal cell inflammation and leukostasis

Diabetic retinopathy (DR) is triggered by retinal cell damage stimulated by the diabetic milieu, including increased levels of intraocular free fatty acids. Free fatty acids may serve as an initiator of inflammatory cytokine release from Müller cells, and the resulting cytokines are potent stimulators of retinal endothelial pathology, such as leukostasis, vascular permeability, and basement membrane thickening. Our previous studies have elucidated a role for peroxisome proliferator-activated receptor-β/δ (PPARβ/δ) in promoting several steps in the pathologic cascade in DR, including angiogenesis and expression of inflammatory mediators. Furthermore, PPARβ/δ is a known target of lipid signaling, suggesting a potential role for this transcription factor in fatty acid-induced retinal inflammation. Therefore, we hypothesized that PPARβ/δ stimulates both the induction of inflammatory mediators by Müller cells as well the paracrine induction of leukostasis in endothelial cells (EC) by Müller cell inflammatory products. To test this, we used the PPARβ/δ inhibitor, GSK0660, in primary human Müller cells (HMC), human retinal microvascular endothelial cells (HRMEC) and mouse retina. We found that palmitic acid (PA) activation of PPARβ/δ in HMC leads to the production of pro-angiogenic and/or inflammatory cytokines that may constitute DR-relevant upstream paracrine inflammatory signals to EC and other retinal cells. Downstream, EC transduce these signals and increase their synthesis and release of chemokines such as CCL8 and CXCL10 that regulate leukostasis and other cellular events related to vascular inflammation in DR. Our results indicate that PPARβ/δ inhibition mitigates these upstream (MC) as well as downstream (EC) inflammatory signaling events elicited by metabolic stimuli and inflammatory cytokines. Therefore, our data suggest that PPARβ/δ inhibition is a potential therapeutic strategy against early DR pathology.

Cyclosporine A eyedrops with self-nanoemulsifying drug delivery systems have improved physicochemical properties and efficacy against dry eye disease in a murine dry eye model

PURPOSE

We aimed to compare the physicochemical properties and in vivo efficacy of commercially available nanoemulsion cyclosporine A (CsA) eyedrops in benzalkonium chloride (BAC)-induced dry eye disease (DED).

METHODS

Particle size analysis was performed on conventional 0.05% CsA (Restasis, C-CsA) and two new types of 0.05% CsA eyedrops based on a self-nanoemulsifying drug delivery system (SNEDDS, SNEDDS-N and -T). Turbidometry, pH measurements and instability indices of each CsA solution were measured. DED was induced with BAC, and animals were treated with vehicle or CsA preparations. Tear volume and fluorescein staining scores were evaluated on days 7 and 14. Eyes were enucleated and subjected to IHC, TUNEL staining, periodic acid-Schiff (PAS) staining, real-time PCR and western blotting.

RESULTS

Both SNEDDSs had lower and more uniform particle size distribution than C-CsA, and a similar optical density to phosphate-buffered saline and stable pH, in contrast to the high turbidity and unstable pH of C-CsA. Aqueous tear volume and fluorescein staining scores were improved in C-CsA- and SNEDDS-treated mice. Numbers of PAS-positive goblet cells and levels of inflammatory mediators were decreased by both C-CsA and SNEDDS, although SNEDDS resolved inflammation more effectively than C-CsA.

CONCLUSIONS

Cyclosporine A eyedrops with SNEDDS have improved physicochemical properties and treatment efficacy in BAC-induced DED.