Anti-VEGF Treatment in Corneal Diseases

Corneal Opacity in the United States: An American Academy of Ophthalmology IRIS® Registry (Intelligent Research in Sight) Study

PURPOSE

This study assesses the case frequencies, underlying causes, and vision outcomes in patients with a diagnosis of corneal opacity in the United States.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Patients in the IRIS® Registry (Intelligent Research in Sight) who received a diagnosis of corneal opacity between January 1, 2013, and November 30, 2020.

METHODS

The IRIS Registry contains demographic and clinical data of 79 887 324 patients who sought treatment at eye clinics during the study period. We identified patients with corneal opacity using International Classification of Diseases (ICD), Ninth and Tenth Revisions, codes of 371 (corneal scar) and H17 (corneal opacity), respectively. The analyzed data comprised demographic parameters including age, sex, race, ethnicity, and geographical location. We evaluated clinical data including laterality, cause, disease descriptors, and best-corrected visual acuity (VA) up to 1 year before the onset (± 30 days), at the time of diagnosis, and at 1 year after diagnosis (± 30 days).

MAIN OUTCOME MEASURES

Case frequencies, causes, and vision outcomes in patients with a diagnosis of corneal opacity.

RESULTS

We identified 5 220 382 patients who received a diagnosis of corneal opacity and scars using H17 (ICD, Tenth Revision) and 371.0 (ICD, Ninth Revision) codes over 7 years. The case frequency of corneal opacity during the study period was 6535 cases per 100 000 patients (6.5%). The mean age of the patients was 63.36 ± 18.14 years, and most were female (57.6%). In the cohort, 38.39% and 30.00% of patients had bilateral and unilateral corneal opacity, respectively. Most of the patients affected by corneal opacity were White (69.13%), followed by Black or African American (6.84%). Corneal dystrophies (64.66%) were the most common cause of corneal opacity in the study cohort. Visual acuity of the patients worsened significantly because of corneal opacity (0.46 ± 0.74 logarithm of the minimum angle of resolution [logMAR]) and did not improve to the baseline (0.37 ± 0.68 logMAR) after management (0.43 ± 0.77 logMAR). The multiple linear regression analysis showed worse vision outcomes in female patients (compared with male patients), and Asian, Black or African American, and American Indian or Alaska Native (compared with White) patients. Additionally, worse vision outcomes were observed in patients with opacity associated with corneal malformation, degenerative disorders, edema, injury, and ulcer compared with those with hereditary corneal dystrophy.

CONCLUSIONS

Our study showed that corneal opacity was diagnosed in 6.5% of patients in the IRIS Registry and primarily associated with corneal dystrophies. The final vision outcomes in patients with corneal opacity were significantly worse compared with baseline.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Inhibition of Experimental Corneal Neovascularization by the Tight Junction Protein ZO-1

Purpose: To explore the effects of the tight junction protein zonula occludens 1 (ZO-1) on experimental corneal neovascularization (CNV). Methods: CNV models were established in the left eyes of BALB/c mice using NaOH. Anti-ZO-1 neutralizing antibody was topically applied to the burnt corneas after modeling thrice a day for 1 week. CD31 expression was analyzed to calculate the ratio of CNV number to area using a corneal whole-mount fluorescent immunohistochemical assay. Messenger ribonucleic acid (mRNA) and protein expression levels of ZO-1, vascular endothelial growth factor (VEGF), interleukin (IL)-1β, IL-6, IL-8, IL-18, monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor alpha (TNF-α), phosphorylated protein kinase C (pPKC), and clusterin in burned corneas were detected by reverse transcriptase polymerase chain reaction (PCR) and western blot analyses. Infiltration of neutrophils, macrophages, and progenitor cells was examined by flow cytometry. Results: CNV was obviously greater in 45 s than in 15 s alkali injury group. In another experiment, CNV was obviously greater in the ZO-1 antibody group than in the vehicle-treated group. Corneal mRNA and protein expression levels of VEGF, IL-1β, IL-6, IL-8, IL-18, and MCP-1 were significantly higher in the ZO-1 antibody group than in the control group. Infiltration of neutrophils, macrophages, and progenitor cells was significantly greater in the ZO-1 antibody group than in the control group. TNF-α expression was much higher in 45 s than in 15 s alkali injury group. However, protein expression of pPKC and clusterin was much lower in 45 s than in 15 s alkali injury group. Conclusions: Anti-ZO-1 neutralizing antibody-treated mice exhibited enhanced alkali-induced CNV through enhanced intracorneal infiltration of progenitor and inflammatory cells.

Elucidating the mechanism of corneal epithelial cell repair: unraveling the impact of growth factors

The repair mechanism for corneal epithelial cell injuries encompasses migration, proliferation, and differentiation of corneal epithelial cells, and extracellular matrix remodeling of the stromal structural integrity. Furthermore, it involves the consequential impact of corneal limbal stem cells (LSCs). In recent years, as our comprehension of the mediating mechanisms underlying corneal epithelial injury repair has advanced, it has become increasingly apparent that growth factors play a pivotal role in this intricate process. These growth factors actively contribute to the restoration of corneal epithelial injuries by orchestrating responses and facilitating specific interactions at targeted sites. This article systematically summarizes the role of growth factors in corneal epithelial cell injury repair by searching relevant literature in recent years, and explores the limitations of current literature search, providing a certain scientific basis for subsequent basic research and clinical applications.

The role of long noncoding RNAs in ocular angiogenesis and vascular oculopathy

BACKGROUND

Long noncoding RNAs (lncRNAs) are RNA transcripts over 200 nucleotides in length that do not code for proteins. Initially considered a genomic mystery, an increasing number of lncRNAs have been shown to have vital roles in physiological and pathological conditions by regulating gene expression through diverse mechanisms depending on their subcellular localization. Dysregulated angiogenesis is responsible for various vascular oculopathies, including diabetic retinopathy, retinopathy of prematurity, age-related macular degeneration, and corneal neovascularization. While anti-VEGF treatment is available, it is not curative, and long-term outcomes are suboptimal, and some patients are unresponsive. To better understand these diseases, researchers have investigated the role of lncRNAs in regulating angiogenesis and models of vascular oculopathies. This review summarizes recent research on lncRNAs in ocular angiogenesis, including the pro-angiogenic lncRNAs ANRIL, HOTAIR, HOTTIP, H19, IPW, MALAT1, MIAT, NEAT1, and TUG1, the anti-angiogenic lncRNAs MEG3 and PKNY, and the human/primate specific lncRNAs lncEGFL7OS, discussing their functions and mechanisms of action in vascular oculopathies.

VEGF signaling: Role in angiogenesis and beyond

Angiogenesis is a crucial process for tissue development, repair, and tumor survival. Vascular endothelial growth factor (VEGF) is a key driver secreted by cancer cells, promoting neovascularization. While VEGF's role in angiogenesis is well-documented, its influence on the other aspects in tumor microenvironemt is less discussed. This review elaborates on VEGF's impact on intercellular interactions within the tumor microenvironment, including how VEGF affects pericyte proliferation and migration and mediates interactions between tumor-associated macrophages and cancer cells, resulting in PDL-1-mediated immunosuppression and Nrf2-mediated epithelial-mesenchymal transition. The review discusses VEGF's involvement in intra-organelle crosstalk, tumor metabolism, stemness, and epithelial-mesenchymal transition. It also provides insights into current anti-VEGF therapies and their limitations in cancer treatment. Overall, this review aims to provide a thorough overview of the current state of knowledge concerning VEGF signaling and its impact, not only on angiogenesis but also on various other oncogenic processes.

A Synergistic Therapy With Antioxidant and Anti-VEGF: Toward its Safe and Effective Elimination for Corneal Neovascularization

Corneal neovascularization (CNV) is one of the leading causes of blindness in the world. In clinical practice; however, it remains a challenge to achieve a noninvasive and safe treatment. Herein, a biocompatible shell with excellent antioxidant and antivascularity is prepared by co-assembly of epigallocatechin gallate/gallic acid and Cu (II). After loading glucose oxidase (GOx) inside, the shell is modified with dimeric DPA-Zn for codelivering vascular endothelial growth factor (VEGF) small interfering RNA (VEGF-siRNA). Meanwhile, the Arg-Gly-Asp peptide (RGD) peptide-engineered cell membranes coating improves angiogenesis-targeting and is biocompatible for the multifunctional nanomedicine (CEGs/RGD). After eye drops administration, CEGs/RGD targets enrichment in neovascularization and CEGs NPs enter cells. Then, the inner GOx consumes glucose with a decrease in local pH, which in turn leads to the release of EGCE and VEGF-siRNA. As a result, the nanomedicines significantly reduce angiogenesis and inhibit CNV formation through synergistic effect of antioxidant and antivascular via down-regulation of cluster of differentiation 31 and VEGF. The nanomedicine represents a safe and efficient CNV treatment through the combined effect of antioxidant/gene, which provides important theoretical and clinical significance.

Aflibercept Loaded Eye-Drop Hydrogel Mediated with Cell-Penetrating Peptide for Corneal Neovascularization Treatment

Corneal neovascularization (CoNV) is a major cause of visual impairment worldwide. Currently, available treatment options have limited efficacy and are associated with adverse effects due to biological barriers and clearance mechanisms. To address this challenge, a novel topical delivery system is developed-Gel 2_1&Eylea-an aflibercept-loaded eye-drop hydrogel mediated with cell-penetrating peptide 1. Gel 2_1&Eylea demonstrates superior membrane permeability, increased stability, and prolonged drug retention time on the ocular surface, and thus may improve drug efficacy. In a rabbit CoNV model, Gel 2_1&Eylea significantly reduces the density of neovascularization with no adverse effects on normal corneoscleral limbal vessels, demonstrating high efficacy and biocompatibility. This work identifies a promising treatment for CoNV which has the potential to benefit other ocular neovascular diseases.

Vascular Endothelial Growth Factor A VEGFA Inhibition: An Effective Treatment Strategy for Psoriasis

Psoriasis is an inflammatory skin disease mediated by the immune system and characterized by an inflammatory ring, also known as an epithelial immune microenvironment (EIME). The interaction between the epithelial tissue of the skin and the immune system has a crucial role in the immune cycle of psoriasis. Although the formation of new blood vessels in skin lesions provides energy support for the proliferation of epidermal keratinocytes, the role of angiogenesis in psoriasis has not been extensively studied. Vascular endothelial growth factor A (VEGFA) is a key regulator of angiogenesis that has an important role in the development of psoriasis. VEGFA promotes angiogenesis and directly stimulates epidermal keratinocytes and infiltrating immune cells, thus contributing to the progression of psoriasis. Measuring VEGFA levels to identify angiogenic characteristics in psoriasis patients may be a predictive biomarker for disease severity and response to anti-angiogenic therapy. Clinical data have shown that anti-angiogenic therapy can improve skin lesions in psoriasis patients. Therefore, this study aimed to uncover the underestimated role of blood vessels in psoriasis, explore the relationship between VEGFA and keratinocytes in the EIME, and inspire innovative drug therapies for the treatment of psoriasis.

Efficient ocular delivery of siRNA via pH-sensitive vehicles for corneal neovascularization inhibition

Corneal neovascularization (CoNV)-induced blindness is an enduring and challenging condition with limited management options. Small interfering RNA (siRNA) is a promising strategy for preventing CoNV. This study reported a new strategy using siVEGFA to silence vascular endothelial growth factor A (VEGFA) for CoNV treatment. To improve the efficacy of siVEGFA delivery, a pH-sensitive polycationic mPEG_2k-PAMA₃₀-P(DEA₂₉-D5A₂₉) (TPPA) was fabricated. TPPA/siVEGFA polyplexes enter cells via clathrin-mediated endocytosis, resulting in higher cellular uptake efficiency and comparable silencing efficiency than that of Lipofectamine 2000 in vitro. Hemolytic assays verified that TPPA safe in normal physiological environments (pH 7.4) but can easily destroy membranes in acidic mature endosomes (pH 4.0). Studies on the distribution of TPPA in vivo showed that it could prolong the retention time of siVEGFA and promote its penetration in the cornea. In a mouse model induced by alkali burn, TPPA efficiently delivered siVEGFA to the lesion site and achieved VEGFA silencing efficiency. Importantly, the inhibitory effect of TPPA/siVEGFA on CoNV was comparable to that of the anti-VEGF drug ranibizumab. Delivering siRNA using pH-sensitive polycations to the ocular environment provides a new strategy to efficiently inhibit CoNV.

Surgical Management of Bilateral Limbal Stem Cell Deficiency

At the age of 43 years-old, a man was left with bilateral limbal stem cell deficiency after an ocular alkaline burn with lime, which resulted in corneal opacification. After multiple unsuccessful surgical attempts to restore vision, including penetrating keratoplasties and Boston keratoprosthesis, visual acuity was counting fingers in the left eye. At 73 years of age, the patient underwent another surgery in his left eye. Cauterization of neovessels and removal of the vascular pannus were followed by partial excision of Tenon's capsule. Penetrating keratoplasty was followed by an intrastromal injection of anti-VEGF (vascular endothelial growth factor), and the ocular surface was covered with amniotic membrane. Postoperatively, the graft was clear with no signs of inflammation; vision improved to 20/50 and remained stable throughout the following two years. Herein we describe some adjunctive procedures that might have delayed failure and rejection of the corneal graft. This case demonstrates the difficulties in treating bilateral limbal stem cell deficiency in a tertiary eye care center with no capacity to perform stem cell therapy.

Development of Osthole-Loaded Microemulsions as a Prospective Ocular Delivery System for the Treatment of Corneal Neovascularization: In Vitro and In Vivo Assessments

Osthole (OST), a natural coumarin compound, has shown a significant inhibitory effect on corneal neovascularization (CNV). But, its effect on treating CNV is restricted by its water insolubility. To overcome this limitation, an OST-loaded microemulsion (OST-ME) was created to improve the drug's therapeutic effect on CNV after topical administration. The OST-ME formulation comprised Capryol-90 (CP-90), Cremophor® EL (EL-35), Transcutol-P (TSP) and water, and sodium hyaluronate (SH) was also included to increase viscosity. The OST-ME had a droplet size of 16.18 ± 0.02 nm and a low polydispersity index (0.09 ± 0.00). In vitro drug release from OST-ME fitted well to the Higuchi release kinetics model. Cytotoxicity assays demonstrated that OST-ME was not notably toxic to human corneal epithelial cells (HCECs), and the formulation had no irritation to rabbit eyes. Ocular pharmacokinetics studies showed that the areas under the concentration-time curves (AUC0-t) in the cornea and conjunctiva were 19.74 and 63.96 μg/g*min after the administration of OST-ME, both of which were 28.2- and 102.34-fold higher than those after the administration of OST suspension (OST-Susp). Moreover, OST-ME (0.1%) presented a similar therapeutic effect to commercially available dexamethasone eye drops (0.025%) on CNV in mouse models. In conclusion, the optimized OST-ME exhibited good tolerance and enhanced 28.2- and 102.34-fold bioavailability in the cornea and conjunctiva tissues compared with suspensions in rabbit eyes. The OST-ME is a potential ocular drug delivery for anti-CNV.

Liposome-trimethyl chitosan nanoparticles codeliver insulin and siVEGF to treat corneal alkali burns by inhibiting ferroptosis

Alkali burns are potentially blinding corneal injuries. Due to the lack of available effective therapies, the prognosis is poor. Thus, effective treatment methods for corneal alkali burns are urgently needed. Codelivery nanoparticles (NPs) with characteristics such as high bioavailability and few side effects have been considered effective therapeutic agents for ocular diseases. In this study, we designed a new combination therapy using liposomes and trimethyl chitosan (TMC) for the codelivery of insulin (INS) and vascular endothelial growth factor small interfering RNA (siVEGF) to treat alkali-burned corneas. We describe the preparation and characterization of siVEGF-TMC-INS-liposome (siVEGF-TIL), drug release characteristics, intraocular tracing, pharmacodynamics, and biosafety. We found that siVEGF-TIL could inhibit oxidative stress, inflammation, and the expression of VEGF in vitro and effectively maintained corneal transparency, accelerated epithelialization, and inhibited corneal neovascularization (CNV) in vivo. Morever, we found that the therapeutic mechanism of siVEGF-TIL is possibly relevant to the inhibition of the ferroptosis signaling pathway by metabolomic analysis. In general, siVEGF-TIL NPs could be a safe and effective therapy for corneal alkali burn.

From bench to clinic: Emerging therapies for corneal scarring

Corneal diseases are one of the leading causes of moderate-to-severe visual impairment and blindness worldwide, after glaucoma, cataract, and retinal disease in overall importance. Given its tendency to affect people at a younger age than other blinding conditions such as cataract and glaucoma, corneal scarring poses a huge burden both on the individuals and society. Furthermore, corneal scarring and fibrosis disproportionately affects people in poorer and remote areas, making it a significant ophthalmic public health problem. Traditional medical strategies, such as topical corticosteroids, are not effective in preventing fibrosis or scars. Corneal transplantation, the only effective sight-restoring treatment for corneal scars, is curbed by challenges including a severe shortage of tissue, graft rejection, secondary conditions, cultural barriers, the lack of well-trained surgeons, operating rooms, and well-equipped infrastructures. Thanks to tremendous research efforts, emerging therapeutic options including gene therapy, protein therapy, cell therapy and novel molecules are in development to prevent the progression of corneal scarring and compliment the surgical options currently available for treating established corneal scars in clinics. In this article, we summarise the most relevant preclinical and clinical studies on emerging therapies for corneal scarring in recent years, showing how these approaches may prevent scarring in its early development.

CXCR3 deletion aggravates corneal neovascularization in a corneal alkali-burn model

Corneal neovascularization can cause devastating consequences including vision impairment and even blindness. Corneal inflammation is a crucial factor for the induction of corneal neovascularization. Current anti-inflammatory approaches are of limited value with poor therapeutic effects. Therefore, there is an urgent need to develop new therapies that specifically modulate inflammatory pathways and inhibit neovascularization in the cornea. The interaction of chemokines and their receptors plays a key role in regulating leukocyte migration during inflammatory response. CXCR3 is essential for mediating the recruitment of activated T cells and microglia/macrophages, but the role of CXCR3 in the initiation and promotion of corneal neovascularization remains unclear. Here, we showed that the expression of CXCL10 and CXCR3 was significantly increased in the cornea after alkali burn. Compared with WT mice, CXCR3-/- mice exhibited significantly increased corneal hemangiogenesis and lymphangiogenesis after alkali burn. In addition, exaggerated leukocyte infiltration and leukostasis, and elevated expression of inflammatory cytokines and angiogenic factor were also found in the corneas of CXCR3-/- mice subjected to alkali burn. With bone marrow (BM) transplantation, we further demonstrated that the deletion of CXCR3 in BM-derived leukocytes plays a key role in the acceleration of alkali burn-induced corneal neovascularization. Taken together, our results suggest that upregulation of CXCR3 does not exhibit its conventional action as a proinflammatory cytokine but instead serves as a self-protective mechanism for the modulation of inflammation and maintenance of corneal avascularity after corneal alkali burn.

Circadian rhythms in psoriasis and the potential of chronotherapy in psoriasis management

The physiology and pathology of the skin are influenced by daily oscillations driven by a master clock located in the brain, and peripheral clocks in individual cells. The pathogenesis of psoriasis is circadian-rhythmic, with flares of disease and symptoms such as itch typically being worse in the evening/night-time. Patients with psoriasis have changes in circadian oscillations of blood pressure and heart rate, supporting wider circadian disruption. In addition, shift work, a circadian misalignment challenge, is associated with psoriasis. These features may be due to underlying circadian control of key effector elements known to be relevant in psoriasis such as cell cycle, proliferation, apoptosis and inflammation. Indeed, peripheral clock pathology may lead to hyperproliferation of keratinocytes in the basal layers, insufficient apoptosis of differentiating keratinocytes in psoriatic epidermis, dysregulation of skin-resident and migratory immune cells and modulation of angiogenesis through circadian oscillation of vascular endothelial growth factor A (VEGF-A) in epidermal keratinocytes. Chronotherapeutic effects of topical steroids and topical vitamin D analogues have been reported, suggesting that knowledge of circadian phase may improve the efficacy, and therapeutic index of treatments for psoriasis. In this viewpoint essay, we review the current literature on circadian disruption in psoriasis. We explore the hypothesis that psoriasis is circadian-driven. We also suggest that investigation of the circadian components specific to psoriasis and that the in vitro investigation of circadian regulation of psoriasis will contribute to the development of a novel chronotherapeutic treatment strategy for personalised psoriasis management. We also propose that circadian oscillations of VEGF-A offer an opportunity to enhance the efficacy and tolerability of a novel anti-VEGF-A therapeutic approach, through the timed delivery of anti-VEGF-A drugs.

Corneal thinning following bevacizumab intrastromal injection for the treatment of idiopathic lipid keratopathy

Purpose

To describe the occurrence of corneal thinning in a patient following intrastromal injection of bevacizumab to treat lipid keratopathy.

Observations

A 36-year-old female presented with decreased vision in her right eye with central posterior corneal haze and underwent a treatment regimen including artificial tears, cyclosporine 0.05% drops, prednisolone 1% and oral Valacyclovir 1g with no improvement. Neovascularization was noted at 18 months follow up and treated with intrastromal bevacizumab injections at 24 months. The feeder vessel was attenuated at 3- and 6-months post-injection, but tomography indicated sustained thinning and flattening of the cornea at the injection site contributing to the development of irregular astigmatism.

Conclusions and Importance

Corneal thinning is an uncommon potential side effect of intrastromal bevacizumab injection that may affect postoperative visual acuity.

Topical application of TAK1 inhibitor encapsulated by gelatin particle alleviates corneal neovascularization

Rationale: Corneal neovascularization (CoNV) is a severe complication of various types of corneal diseases, that leads to permanent visual impairment. Current treatments for CoNV, such as steroids or anti-vascular endothelial growth factor agents, are argued over their therapeutic efficacy and adverse effects. Here, we demonstrate that transforming growth factor-β (TGF-β)-activated kinase 1 (TAK1) plays an important role in the pathogenesis of CoNV. Methods: Angiogenic activities were assessed in ex vivo and in vitro models subjected to TAK1 inhibition by 5Z-7-oxozeaenol, a selective inhibitor of TAK1. RNA-Seq was used to examine pathways that could be potentially affected by TAK1 inhibition. A gelatin-nanoparticles-encapsulated 5Z-7-oxozeaenol was developed as the eyedrop to treat CoNV in a rodent model. Results: We showed that 5Z-7-oxozeaenol reduced angiogenic processes through impeding cell proliferation. Transcriptome analysis suggested 5Z-7-oxozeaenol principally suppresses cell cycle and DNA replication, thereby restraining cell proliferation. In addition, inhibition of TAK1 by 5Z-7-oxozeaenol blocked TNFα-mediated NFκB signalling, and its downstream genes related to angiogenesis and inflammation. 5Z-7-oxozeaenol also ameliorated pro-angiogenic activity, including endothelial migration and tube formation. Furthermore, topical administration of the gelatin-nanoparticles-encapsulated 5Z-7-oxozeaenol led to significantly greater suppression of CoNV in a mouse model compared to the free form of 5Z-7-oxozeaenol, likely due to extended retention of 5Z-7-oxozeaenol in the cornea. Conclusion: Our study shows the potential of TAK1 as a therapeutic target for pathological angiogenesis, and the gelatin nanoparticle coupled with 5Z-7-oxozeaenol as a promising new eyedrop administration model in treatment of CoNV.

Deliver protein across bio-barriers via hexa-histidine metal assemblies for therapy: a case in corneal neovascularization model

Because of their high specificity and low side effects, protein drugs possess a substantial global market. However, the low bioavailability of protein is still a major obstacle to their expanded applications, which is expected to be answered with proper protein formulations. Taking corneal neovascularization (CNV) as an example, we demonstrated a co-assembled system of hexa-histidine and Ava (Avastin) with metal ions (HmA@Ava) could cross the cornea, the most important bio-barrier during the treatment of most diseases of the anterior segment in clinics. We found that the nanosized HmA@Ava efficiently encapsulated Ava with impressive loading capacity without destroying the bioactivity of Ava and assisted Ava penetration through the corneal barriers to effectively inhibit CNV development in an alkali burn rat model with sustained and pH-dependent Ava release. Our results suggested that the co-assembled strategy of protein and HmA is a proper formulation to protein drugs, with promising penetration ability to deliver protein across bio-barriers, which could open a path for topical administration of protein drugs for treatment of various ocular diseases and hold enormous potential for delivery of therapeutic proteins not only for ocular diseases but also for other diseases that require protein treatment.

•

HmA@Ava can bring protein drug, Ava, across over the primary bio-barrier of the anterior segment ​and efficiently treat CNV.

•

HmA@Ava was nanoparticles, with impressive loading capacity without destroying bioactivity of Ava ​and strong pH-dependent release.

•

HmA can open a path for the treatment of eye diseases and hold huge potential to protein drugs to other diseases.

Engeletin protects against cerebral ischemia/reperfusion injury by modulating the VEGF/vasohibin and Ang-1/Tie-2 pathways

Engeletin is a natural derivative of Smilax glabra rhizomilax that exhibits anti-inflammatory activity and suppresses lipid peroxidation. In the present study, we sought to elucidate the mechanistic basis for the neuroprotective and pro-angiogenic activity of engeltin in a human umbilical vein endothelial cells (HUVECs) oxygen-glucose deprivation and reoxygenation (OGD/R) model system and a middle cerebral artery occlusion (MCAO) rat model of cerebral ischemia and reperfusion injury. These analyses revealed that engeletin (10, 20, or 40 mg/kg) was able to reduce the infarct volume, increase cerebral blood flow, improve neurological function, and bolster the expression of vascular endothelial growth factor (VEGF), vasohibin-2 (Vash-2), angiopoietin-1 (Ang-1), phosphorylated human angiopoietin receptor tyrosine kinase 2 (p-Tie2), and platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31) in MCAO rats. Similarly, engeletin (100, 200, or 400 nM) markedly enhanced the migration, tube formation, and VEGF expression of HUVECs in an OGD/R model system, while the VEGF receptor (R) inhibitor axitinib reversed the observed changes in HUVEC tube formation activity and Vash-2, VEGF, and CD31 expression. These data suggested that engeletin exhibited significant neuroprotective effects against cerebral ischemia and reperfusion injury in rats, and improved cerebrovascular angiogenesis by modulating the VEGF/vasohibin and Ang-1/Tie-2 pathways.

The two-faced effects of nerves and neuropeptides in corneal diseases

Corneal nerves are instrumental to maintain cornea integrity through regulation of key physiological functions such as tear secretion, blink reflex, and neuropeptide turnover. Corneal nerve injury/stimulation can follow many insults including mechanical/chemical trauma, infections and surgeries. Nerve disruption initiates a process named neurogenic inflammation which leads to edema, pain, and recruitment and activation of leukocytes. Interestingly, leukocyte influx in the cornea can further damage nerves by releasing inflammatory mediators-including neuropeptides. The clinical outcome of neuroinflammation can be beneficial or detrimental to corneal integrity. On one side, it ensures prompt wound healing and prevents infections. On the other, prolonged and/or deranged neuroinflammation can permanently disrupt corneal integrity and impair vision. The cornea is an ideal site to study peripheral neuroinflammation and neurogenic inflammation since it receives the highest density of sensory nerves of the entire body. We will review the corneal nerve anatomy and neurochemistry, discuss the beneficial and detrimental effects of neurogenic inflammation in corneal wound healing, inflammatory processes, and pain. We will also examine the emerging remote impact of corneal nerve disruption on the trigeminal ganglion and the brain, highlighting the key role of neuropeptide Substance P. Finally, we will discuss the clinical relevance of such neuroinflammatory network in the context of severe and highly prevalent ocular diseases, including potential treatments.

Vascular endothelial growth factor-A as a promising therapeutic target for the management of psoriasis

Vascular endothelial growth factor-A (VEGF-A), the main angiogenic mediator, plays a critical role in the pathogenesis of several inflammatory immune-mediated diseases, including psoriasis. Even though anti-angiogenic therapies, such as VEGF inhibitors, are licensed for the treatment of various cancers and eye disease, VEGF-targeting interventions are not part of current psoriasis therapy. In this viewpoint essay, we argue that the existing preclinical research evidence on the role of VEGF-A in the pathogenesis of psoriasis as well as clinical observations in patients who have experienced psoriasis remission during oncological anti-VEGF-A therapy strongly suggests to systematically explore angiogenesis targeting also in the management of psoriasis. We also point out that some psoriasis therapies decrease circulating levels of VEGF-A and normalise the psoriasis-associated vascular pathology in the papillary dermis of plaques of psoriasis and that a subset of patients with constitutionally high levels of VEGF-A may benefit most from the anti-angiogenic therapy we advocate here. Given that novel, well-targeted personalised medicine therapies for the development of psoriasis need to be developed, we explore the hypothesis that VEGF-A and signalling through its receptors constitute a promising target for therapeutic intervention in the future management of psoriasis.