Anti-angiogenic and anti-inflammatory effects of SERPINA3K on corneal injury

A novel tissue-engineered corneal epithelium based on ultra-thin amniotic membrane and mesenchymal stem cells

Currently, in vitro cultured corneal epithelial transplantation is effective in treating limbal stem cell dysfunction (LSCD). Selecting carriers is crucial for constructing the corneal epithelium through tissue engineering. In this study, the traditional amniotic membrane (AM) was modified, and mesenchymal stem cells (MSCs) were inoculated into the ultra-thin amniotic membrane (UAM) stroma to construct a novel UAM-MSC tissue-engineered corneal epithelial carrier, that could effectively simulate the limbal stem cells (LSCs) microenvironment. The structure of different carriers cultured tissue-engineered corneal epithelium and the managed rabbit LSCD model corneas were observed through hematoxylin-eosin staining. Cell phenotypes were evaluated through fluorescence staining, Western blotting, and RT-qPCR. Additionally, cell junction genes and expression markers related to anti-neovascularization were evaluated using RT-qPCR. Corneal epithelium cell junctions were observed via an electron microscope. The tissue-engineered corneal epithelium culture medium was analyzed through mass spectrometry. Tissue-engineered corneal epithelial cells expanded by LSCs on UAM-MSCs had good transparency. Simultaneously, progenitor cell (K14, PNCA, p63) and corneal epithelial (PAX6) gene expression in tissue-engineered corneal epithelium constructed using UAM-MSCs was higher than that in corneal epithelial cells amplified by UAM and de-epithelialized amniotic membrane. Electron microscopy revealed that corneal epithelial cells grafted with UAM-MSCs were closely connected. In conclusion, the UAM-MSCs vector we constructed could better simulate the limbal microenvironment; the cultured tissue-engineered corneal epithelium had better transparency, anti-neovascularization properties, closer intercellular connections, and closer resemblance to the natural corneal epithelial tissue phenotype.

Role of Serine Protease Inhibitors A1 and A3 in Ocular Pathologies

Serine protease inhibitors A1 (SerpinA1) and A3 (SerpinA3) are important members of the serpin family, playing crucial roles in the regulation of serine proteases and influencing various physiological processes. SerpinA1, also known as α-1-antitrypsin, is a versatile glycoprotein predominantly synthesized in the liver, with additional production in inflammatory and epithelial cell types. It exhibits multifaceted functions, including immune modulation, complement activation regulation, and inhibition of endothelial cell apoptosis. SerpinA3, also known as α-1-antichymotrypsin, is expressed both extracellularly and intracellularly in various tissues, particularly in the retina, kidney, liver, and pancreas. It exerts anti-inflammatory, anti-angiogenic, antioxidant, and antifibrotic activities. Both SerpinA1 and SerpinA3 have been implicated in conditions such as keratitis, diabetic retinopathy, age-related macular degeneration, glaucoma, cataracts, dry eye disease, keratoconus, uveitis, and pterygium. Their role in influencing metalloproteinases and cytokines, as well as endothelial permeability, and their protective effects on Müller cells against oxidative stress further highlight their diverse and critical roles in ocular pathologies. This review provides a comprehensive overview of the etiology and functions of SerpinA1 and SerpinA3 in ocular diseases, emphasizing their multifaceted roles and the complexity of their interactions within the ocular microenvironment.

Exploring the Role of Lycium barbarum Polysaccharide in Corneal Injury Repair and Investigating the Relevant Mechanisms through In Vivo and In Vitro Experiments

Lycium barbarum polysaccharide (LBP) is the main active component of Fructus Lycii, exhibiting various biological activities. This study aims to explore the protective effects of LBP on human corneal epithelial cells (HCEC) and a rat corneal injury model. Potential target points for LBP improving corneal injury repair were screened from public databases, and functional and pathway enrichment analyses of core targets were conducted using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Rat corneal alkali burns and HCEC oxidative stress injury models were established, and the results were validated through slit lamp examination, HE staining, TUNEL assay, immunofluorescence, CCK-8 assay, flow cytometry, scratch assay, and qRT-PCR methods. In the context of database retrieval, identification of 10 LBP monosaccharide components and 50 corneal injury repair-related targets was achieved. KEGG pathway analysis suggested that LBP might regulate the IL-17 and TNF signaling pathways through targets such as JUN, CASP3, and MMP9, thereby improving corneal damage. In vivo and in vitro experimental results indicated that LBP could reduce the increase of inflammation index scores (p < 0.05), inflammatory cell density (p < 0.01), TUNEL-positive cells (p < 0.01), corneal opacity scores (p < 0.01), and expression of corneal stromal fibrosis-related proteins α-SMA, FN, and COL (p < 0.01) caused by chemical damage to rat corneas. LBP inhibited oxidative stress-induced decreases in cell viability (p < 0.001) and migration healing ability (p < 0.01) in HCECs, reducing apoptosis rates (p < 0.001), ROS levels (p < 0.001), and the expression of inflammatory factors TNF-α and IL-6 (p < 0.01). qRT-PCR results demonstrated that LBP intervention decreased the mRNA levels of JUN, CASP3, and MMP9 in H2O2-induced alkaline-burned corneas and HCECs (p < 0.01).The integrated results from network pharmacology and validation experiments suggest that the inhibitory effects of LBP on apoptosis, inflammation, and fibrosis after corneal injury may be achieved through the suppression of the TNF and IL-17 signaling pathways mediated by JUN, CASP3, and MMP9.

Rapamycin inhibits corneal inflammatory response and neovascularization in a mouse model of corneal alkali burn

Alkali burn-induced corneal injury often causes inflammation and neovascularization and leads to compromised vision. We previously reported that rapamycin ameliorated corneal injury after alkali burns by methylation modification. In this study, we aimed to investigate the rapamycin-medicated mechanism against corneal inflammation and neovascularization. Our data showed that alkali burn could induce a range of different inflammatory response, including a stark upregulation of pro-inflammatory factor expression and an increase in the infiltration of myeloperoxidase- and F4/80-positive cells from the corneal limbus to the central stroma. Rapamycin effectively downregulated the mRNA expression levels of tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), toll-like receptor 4 (TLR4), nucleotide binding oligomerization domain-like receptors (NLR) family pyrin domain-containing 3 (NLRP3), and Caspase-1, and suppressed the infiltration of neutrophils and macrophages. Inflammation-related angiogenesis mediated by matrix metalloproteinase-2 (MMP-2) and rapamycin restrained this process by inhibiting the TNF-α upregulation in burned corneas of mice. Rapamycin also restrained corneal alkali burn-induced inflammation by regulating HIF-1α/VEGF-mediated angiogenesis and the serum cytokines TNF-α, IL-6, Interferon-gamma (IFN-γ) and granulocyte-macrophage colony-stimulating factor (GM-CSF). The findings of this study indicated rapamycin may reduce inflammation-associated infiltration of inflammatory cells, shape the expression of cytokines, and balance the regulation of MMP-2 and HIF-1α-mediated inflammation and angiogenesis by suppressing mTOR activation in corneal wound healing induced by an alkali injury. It offered novel insights relevant for a potent drug for treating corneal alkali burn.

SerpinA3K Deficiency Reduces Oxidative Stress in Acute Kidney Injury

We previously showed that SerpinA3K is present in urine from rats and humans with acute kidney injury (AKI) and chronic kidney disease (CKD). However, the specific role of SerpinA3K during renal pathophysiology is unknown. To begin to understand the role of SerpinA3K on AKI, SerpinA3K-deficient (KOSA3) mice were studied 24 h after inducing ischemia/reperfusion (I/R) and compared to wild type (WT) mice. Four groups were studied: WT+S, WT+IR, KOSA3+S, and KOSA3+IR. As expected, I/R increased serum creatinine and BUN, with a GFR reduction in both genotypes; however, renal dysfunction was ameliorated in the KOSA3+IR group. Interestingly, the increase in UH₂O₂ induced by I/R was not equally seen in the KOSA3+IR group, an effect that was associated with the preservation of antioxidant enzymes' mRNA levels. Additionally, FOXO3 expression was initially greater in the KOSA3 than in the WT group. Moreover, the increase in BAX protein level and the decrease in Hif1a and Vegfa induced by I/R were not observed in the KOSA3+IR group, suggesting that these animals have better cellular responses to hypoxic injury. Our findings suggest that SerpinA3K is involved in the renal oxidant response, HIF1α/VEGF pathway, and cell apoptosis.

Accelerating corneal wound healing using exosome-mediated targeting of NF-κB c-Rel

The integrity of the corneal epithelium is essential for the maintenance of the physiological function of the cornea. Studies have found that inflammation greatly delays corneal wound healing. NF-κB c-Rel is preferentially expressed by immune cells and promotes the expression of inflammatory cytokines. In the current study, we sought to investigate whether c-Rel could be used as a potential therapeutic target for treating a corneal injury. Our studies reveal that expressions of c-Rel and its inflammatory targets are significantly increased in the cornea of mice with corneal injury. In addition, we find that c-Rel-deficient mice exhibit accelerated corneal wound healing and reduced expression of inflammatory cytokines. Further studies show that topical treatment on the corneal surface using nano-polymers or exosomes loaded with c-Rel-specific siRNA (siRel) can effectively accelerate regular and diabetic corneal wound healing. More importantly, we find that exosomes, as carriers of siRel, showed better efficacy than nano-polymers in treating corneal injury. We further demonstrate that exosomes secreted by mesenchymal stem cells can efficiently transfer siRNA into macrophages and dendritic cells but not T cells. Taken together, these results indicate that blocking c-Rel may represent an attracting strategy for the treatment of both regular and diabetic corneal injury.

Proteases and Their Potential Role as Biomarkers and Drug Targets in Dry Eye Disease and Ocular Surface Dysfunction

Dry eye disease (DED) is a multifactorial disorder that leads to ocular discomfort, visual disturbance, and tear film instability. DED is accompanied by an increase in tear osmolarity and ocular surface inflammation. The diagnosis and treatment of DED still present significant challenges. Therefore, novel biomarkers and treatments are of great interest. Proteases are present in different tissues on the ocular surface. In a healthy eye, proteases are highly regulated. However, dysregulation occurs in various pathologies, including DED. With this review, we provide an overview of the implications of different families of proteases in the development and severity of DED, along with studies involving protease inhibitors as potential therapeutic tools. Even though further research is needed, this review aims to give suggestions for identifying novel biomarkers and developing new protease inhibitors.

Prophylactic Instillation of Hydrogen-Rich Water Decreases Corneal Inflammation and Promotes Wound Healing by Activating Antioxidant Activity in a Rat Alkali Burn Model

Many studies have demonstrated the therapeutic effects of hydrogen in pathological conditions such as inflammation; however, little is known about its prophylactic effects. The purpose of this study is to investigate the prophylactic effects of hydrogen-rich water instillation in a rat corneal alkali burn model. Hydrogen-rich water (hydrogen group) or physiological saline (vehicle group) was instilled continuously to the normal rat cornea for 5 min. At 6 h after instillation, the cornea was exposed to alkali. The area of corneal epithelial defect (CED) was measured every 6 h until 24 h after alkali exposure. In addition, at 6 and 24 h after injury, histological and immunohistochemical observations were made and real-time reverse transcription polymerase chain reaction (RT-PCR) was performed to investigate superoxide dismutase enzyme (SOD)1, SOD2, and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) mRNA expression. CED at 12 h and the number of inflammatory infiltrating cells at 6 h after injury were significantly smaller in the hydrogen group than the vehicle group. Furthermore, SOD1 expression was significantly higher in the hydrogen group than the vehicle group at both 6 and 24 h, and the number of PGC-1α-positive cells was significantly larger in the hydrogen group than the vehicle group at 6 h after injury. In this model, prophylactic instillation of hydrogen-rich water suppressed alkali burn-induced inflammation, likely by upregulating expression of antioxidants such as SOD1 and PGC-1α. Hydrogen has not only therapeutic potential but also prophylactic effects that may suppress corneal scarring following injury and promote wound healing.

MiR-335 promotes corneal neovascularization by Targeting EGFR

Background

Corneal neovascularization (CRNV) is a severe threat to the vision of people. MicroRNA-335 (miR-335) has the function of facilitating angiogenesis. However, whether miR-335 regulates the progression of CRNV remains unclear.

Methods

The miR-335 expressions in CRNV rats induced by corneal suture and HUVECs induced by b-FGF were detected by quantitative real-time PCR. For the miR-335 function, wound healing and tube formation assays were performed. For the miR-335 mechanism, a dual-luciferase reporter gene assay was conducted. Besides, for the epidermal growth factor receptor (EGFR) function, Cell Counting Kit-8 and wound healing assays were performed. Meanwhile, the rescue assay was used to assess the miR-335/EGFR function in the migration and angiogenesis of b-FGF-treated HUVECs.

Results

Functionally, the miR-335 knockdown weakened the migration and angiogenesis of b-FGF-treated HUVECs, while the miR-335 overexpression showed an opposite trend. Mechanistically, miR-335 interacted with EGFR and negatively regulated the expression of EGFR. The rescue assay illustrated that miR-335 regulated the migration and angiogenesis of b-FGF-treated HUVECs through EGFR.

Conclusions

In general, our data confirmed that miR-335 facilitated the process of CRNV by targeting EGFR.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02481-0.

Brain vasculature disturbance in schizophrenia

PURPOSE OF REVIEW

The vascular hypothesis of schizophrenia (SZ) postulates that brain endothelial dysfunction contributes to brain pathophysiology. This review discusses recent evidence for and against this hypothesis, including data related to blood-brain barrier (BBB), brain endothelium, and brain blood supply, to provide a critical weighed update.

RECENT FINDINGS

Different studies report a consistent proportion of SZ patients showing increased BBB permeability, reflected by higher levels of albumin in the cerebral spinal fluid. Of note, this was not a result of antipsychotic medication. The high inflammatory profile observed in some SZ patients is strongly associated with increased BBB permeability to circulating immune cells, and with more severe cognitive deficiencies. Also, sex was found to interact with BBB integrity and permeability in SZ. The strongest independent genetic association with SZ has been identified in FZD1, a hypoxia-response gene that is 600-fold higher expressed in early development endothelium as compared to adult brain endothelium. Regarding brain blood supply, there is evidence to suggest alterations in proper brain perfusion in SZ. Nonetheless, ex-vivo experiments suggested that widely used antipsychotics favor vasoconstriction; thus, alterations in cerebral perfusion might be related to the patients' medication.

SUMMARY

In some patients with SZ, a vulnerable brain endothelium may be interacting with environmental stressors, such as inflammation or hypoxia, converging into a more severe SZ symptomatology. Gene expression and performance of human brain endothelium could vary along with development and the establishment of the BBB; therefore, we encourage to investigate its possible contribution to SZ considering this dynamic context.

Transient response of serpinA3 during cellular stress

We demonstrated that serpinA3c/k relocates from the cytoplasm to the apical tubular membrane (ATM) in chronic kidney disease (CKD), suggesting its secretion in luminal space in pathophysiological contexts. Here, we studied serpinA3c/k expression and secretion under different stressful conditions in vitro and in vivo. HEK-293 cells were transfected with a FLAG-tagged serpinA3c/k clone and exposed to H₂ O₂ or starvation. Both stressors induced serpinA3c/k secretion but with a higher molecular weight. Glycanase treatment established that serpinA3c/k is glycosylated. Site-directed mutagenesis for each of the four glycosylation sites was performed. During cellular stress, serpinA3c/k secretion increased with each mutant except in the quadruple mutant. In rats and patients suffering acute kidney injury (AKI), an atypical urinary serpinA3c/k excretion (uSerpinA3c/k) was observed. In rats with AKI, the greater the induced kidney damage, the greater the uSerpinA3 c/k, together with relocation toward ATM. Our findings show that: (1) serpinA3c/k is glycosylated and secreted, (2) serpinA3c/k secretion increases during cellular stress, (3) its appearance in urine reveals a pathophysiological state, and (4) urinary serpinA3 excretion could become a potential biomarker for AKI.

Tandem Mass Tag-Based Quantitative Proteomic Analysis Reveals Pathways Involved in Brain Injury Induced by Chest Exposure to Shock Waves

Recurrent chest blast exposure can lead to brain inflammation, oxidative stress, and mental disorders in soldiers. However, the mechanism that underlies brain injury caused indirectly by chest blasts remains unclear. It is urgent to find additional reliable biomarkers to reveal the intimate details of the pathogenesis of this phenomenon. We used the term tandem mass tag (TMT) labeling combined with liquid chromatography–tandem mass spectrometry (LC-MS/MS) to screen for differentially expressed proteins in rat brain at different time points after a chest blast. Data are available via ProteomeXchange with the identifier PXD025204. Gene Ontology (GO), the Kyoto Encyclopedia of Genes and Genomes (KEGG), the Database for Annotation, Visualization and Integrated Discovery (DAVID), and Cytoscape analyses were used to analyze the proteomic profiles of blast-exposed rats. In addition, we performed Western blotting to verify protein levels. We identified 6,931 proteins, of which 255 were differentially expressed and 43, 84, 52, 97, and 49 were identified in brain tissues at 12, 24, 48, and 72 h and 1 week after chest blast exposure, respectively. In this study, the GO, KEGG, Clusters of Orthologous Groups of proteins, and Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) analyses indicated that brain damage caused by chest blast exposure involved many important biological processes and signaling pathways, such as inflammation, cell adhesion, phagocytosis, neuronal and synaptic damage, oxidative stress, and apoptosis. Furthermore, Western blotting confirmed that these differentially expressed proteins and affected signaling pathways were associated with brain damage caused by chest blast exposure. This study identifies potential protein biomarkers of brain damage caused indirectly by chest blast and new targets for the treatment of this condition.

Serp-1 Promotes Corneal Wound Healing by Facilitating Re-epithelialization and Inhibiting Fibrosis and Angiogenesis

Purpose: Chemical corneal injuries carry a high morbidity and commonly lead to visual impairment. Here, we investigate the role of Serp-1, a serine protease inhibitor, in corneal wound healing.

Methods: An alkaline-induced corneal injury was induced in 14 mice. Following injury, five mice received daily topical saline application while nine mice received Serp-1 100 μL topically combined with a daily subcutaneous injection of 100 ng/gram body weight of Serp-1. Corneal damage was monitored daily through fluorescein staining and imaging. Cross sectional corneal H&E staining were obtained. CD31 was used as marker for neovascularization.

Results: Serp-1 facilitates corneal wound healing by reducing fibrosis and neovascularization while mitigating inflammatory cell infiltration with no noticeable harm related to its application.

Conclusions: Serp-1 effectively mitigates inflammation, decreases fibrosis, and reduce neovascularization in a murine model of corneal injury without affecting other organs.

Translational Relavence: Our study provides preclinical data for topical application of Serp-1 to treat corneal wounds.

Treatment of Corneal Alkali Burn with Chestnut Honey, Royal Jelly, and Chestnut Honey-Royal Jelly Mixture

Objectives:

The alkaline burn of the cornea usually results in a decreased vision with opacification. In this study, we investigated the potential role of endemic chestnut honey (CH) and royal jelly on corneal healing after an alkaline burn.

Methods:

We created an alkaline burn on the center of the corneas of four groups of Wistar rats by applying round filter paper soaked with 1 N NaOH for 30 seconds. The animals were treated with RJ, CH, RJ-CH combination and Na-Hyaluronate (Na-HA) eye drops. We performed a serial evaluation with anterior segment photography on the first, 7th, and 14th days of the experiment. Pathologic examination conducted with hematoxylin and eosin stains and immunostaining for SMA and α4β1 integrin. We evaluated the corneal healing process with a scoring system, which was estimating the degree of corneal edema, the size of the corneal ulcer, and limbal hyperemia.

Results:

There was no statistically significant difference between groups on the first, 7^th, and 14^th days concerning the healing scores (p=0.88, p=0.06, p=0.80, respectively). However, there were significantly better scores in the repeated measures of CH (p=0.012) and RJ-CH (p=0.00) groups. The RJ group and Na-HA group did not show a significant difference in repeated measures (p=0.19 and p=0.10, respectively). The α4β1 integrin levels on immunostaining showed a significant difference among groups on the 14^th day (p=0.002).

Conclusion:

We found better corneal healing after treatment with the RJ-CH containing eye drops concerning corneal healing sore and α4β1 integrin staining.

Neuroprotective Effects of Serpina3k in Traumatic Brain Injury

Traumatic brain injury (TBI) is a major cause of disability and mortality worldwide, in part resulting from secondary apoptosis of neurons in peri-contusion areas. Serpina3k, a serine protease inhibitor, has been shown to inhibit apoptosis in injury models. In this study, we investigated the anti-apoptotic function of serpina3k in vivo using a mouse model of TBI, as well as the underlying neuroprotective mechanism in vitro using the SH-SY5Y human neuroblastoma cell line. TBI was induced in adult male C57BL/6 mice using controlled cortical impact. Serpina3k protein was intravenously administered at a concentration of 0.5 mg/kg twice daily for up to 14 days. SH-SY5Y cells were subjected to biaxial stretch injury and then treated with different concentrations of serpina3k. We found that endogenous serpina3k protein levels were elevated in peri-contusion areas of the mouse brain following TBI. Serpina3k-treated mice had fewer apoptotic neurons, lower levels of oxidative stress, and showed greater recovery of neurological deficits relative to vehicle-treated mice. Meanwhile, in the SH-SY5Y cell injury model, serpina3k at an optimal concentration (150 nM) inhibited the generation of intracellular reactive oxygen species, abrogated changes of the mitochondrial membrane potential, and reduced the phospho-extracellular regulated protein kinases (p-ERK)/ERK, phospho-P38 (p-P38)/P38, B cell lymphoma (Bcl)-2-associated X protein/Bcl-2, and cleaved caspase-3/caspase-3 ratios, thereby reducing the apoptosis rate. These results demonstrate that serpina3k exerts a neuroprotective function following TBI and thus has therapeutic potential.

SerpinA3 in the Early Recognition of Acute Kidney Injury to Chronic Kidney Disease (CKD) transition in the rat and its Potentiality in the Recognition of Patients with CKD

Recognizing patients at early phases of chronic kidney disease (CKD) is difficult, and it is even more challenging to predict acute kidney injury (AKI) and its transition to CKD. The gold standard to timely identify renal fibrosis is the kidney biopsy, an invasive procedure not usually performed for this purpose in clinical practice. SerpinA3 was identified by high-resolution-mass-spectrometry in urines from animals with CKD. An early and progressive elevation of urinary SerpinA3 (uSerpinA3) was observed during the AKI to CKD transition together with SerpinA3 relocation from the cytoplasm to the apical tubular membrane in the rat kidney. uSerpinA3/alpha-1-antichymotrypsin was significantly increased in patients with CKD secondary to focal and segmental glomerulosclerosis (FSGS), ANCA associated vasculitis (AAV) and proliferative class III and IV lupus nephritis (LN). uSerpinA3 levels were independently and positively associated with renal fibrosis. In patients with class V LN, uSerpinA3 levels were not different from healthy volunteers. uSerpinA3 was not found in patients with systemic inflammatory diseases without renal dysfunction. Our observations suggest that uSerpinA3 can detect renal fibrosis and inflammation, with a particular potential for the early detection of AKI to CKD transition and for the differentiation among lupus nephritis classes III/IV and V.

Elevated Kallikrein-binding protein in diabetes impairs wound healing through inducing macrophage M1 polarization

Background

The accumulation of M1-polarized macrophages and excessive inflammation are important in the pathogenesis of diabetic foot ulcer (DFU). However, the underlying mechanism of DFU pathogenesis and the crucial regulators of DFU are less well known. Our previous study reported that kallikrein-binding protein (KBP), an angiogenesis inhibitor, was significantly upregulated in diabetic patients compared to its levels in controls. The effects of KBP on monocyte chemotaxis and macrophage M1 polarization were elucidated in this study.

Methods

Plasma KBP levels and monocyte counts were assessed by ELISA and flow cytometry. Wound closure rates in different groups were monitored daily. The phenotype and recruitment of macrophages were measured by real-time PCR, western blot and immunofluorescence assays. The expression of Notch and NF-κB signalling pathway members was determined by the methods mentioned above. ChIP and dual-luciferase reporter gene assays were employed to explore the binding and transcriptional regulation of Hes1 and iNOS.

Results

We found that plasma KBP levels and circulating monocytes were elevated in diabetic patients compared to those in nondiabetic controls, and both were higher in diabetic patients with DFU than in diabetic patients without DFU. KBP delayed wound healing in normal mice; correspondingly, KBP-neutralizing antibody ameliorated delayed wound healing in diabetic mice. Circulating monocytes and macrophage infiltration in the wound were upregulated in KBP-TG mice compared to those in control mice. KBP promoted the recruitment and M1 polarization of macrophages. Mechanistically, KBP upregulated iNOS by activating the Notch1/RBP-Jκ/Hes1 signalling pathway. Hes1 downregulated CYLD, a negative regulator of NF-κB signalling, and then activated the IKK/IκBα/NF-κB signalling pathway.

Conclusions

Our findings demonstrate that KBP is the key regulator of excessive inflammation in DFUs and provide a novel target for DFU therapy.

Electronic supplementary material

The online version of this article (10.1186/s12964-019-0376-9) contains supplementary material, which is available to authorized users.

Transcriptome Profiling of Neovascularized Corneas Reveals miR-204 as a Multi-target Biotherapy Deliverable by rAAVs

Corneal neovascularization (NV) is the major sight-threatening pathology caused by angiogenic stimuli. Current drugs that directly target pro-angiogenic factors to inhibit or reverse the disease require multiple rounds of administration and have limited efficacies. Here, we identify potential anti-angiogenic corneal microRNAs (miRNAs) and demonstrate a framework that employs discovered miRNAs as biotherapies deliverable by recombinant adeno-associated viruses (rAAVs). By querying differentially expressed miRNAs in neovascularized mouse corneas induced by alkali burn, we have revealed 39 miRNAs that are predicted to target more than 5,500 differentially expressed corneal mRNAs. Among these, we selected miR-204 and assessed its efficacy and therapeutic benefit for treating injured corneas. Our results show that delivery of miR-204 by rAAV normalizes multiple novel target genes and biological pathways to attenuate vascularization of injured mouse cornea. Importantly, this gene therapy treatment alternative is efficacious and safe for mitigating corneal NV. Overall, our work demonstrates the discovery of potential therapeutic miRNAs in corneal disorders and their translation into viable treatment alternatives.

Antiangiogenic effects of catalpol on rat corneal neovascularization

To investigate the effects of catalpol on corneal neovascularization (CNV) and associated inflammation, eye drops (5 mM catalpol or PBS) were administered four times daily to alkali-burn rat models of CNV and inflammation. Clinical evaluations of CNV and the degree of inflammation were performed on days 0, 4, 7, 10 and 14 under slit lamp microscopy. Eyes were collected on day 14 and prepared for hematoxylin and eosin, and immunofluorescence staining; corneal cell apoptosis was investigated via terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) staining. Protein expression levels of angiogenic and proinflammatory factors, including vascular endothelial growth factor (VEGF), pigment epithelium-derived factor (PEDF), tumor necrosis factor-α (TNF-α) and necrosis factor-κB (NF-κB) were determined by western blotting. The effects of catalpol on cell proliferation were investigated in vitro using human umbilical vein endothelial cells (HUVECs) and a Cell Counting kit-8 (CCK-8); alterations in migration and tube formation were investigated via HUVEC wound closure and tube formation assays. HUVEC viability and proliferative ability were inhibited in a dose-dependent manner; catalpol also decreased HUVEC cell migration and tube forming ability. Within alkali-burn rat models, decreased inflammation and CNV was associated with catalpol administration; as demonstrated with TUNEL, corneal cell apoptosis was decreased in response to catalpol. Western blot analysis revealed reduced protein expression levels of VEGF and TNF-α; however, PEDF and phosphorylated-NF-κB p65 were increased due to catalpol administration. The present study demonstrated the inhibitory effects exerted by catalpol on CNV and inflammation within alkali-burned rat models. Topical application of catalpol in vivo was associated with reduced CNV and inflammation; therefore, catalpol may be considered an anti-inflammatory agent for the clinical treatment of CNV.

A novel peptide specifically binding to VEGF receptor suppresses angiogenesis in vitro and in vivo

Vascular endothelial growth factor (VEGF), one of the most important angiogenic factors, plays an essential role in both physiological and pathological angiogenesis through binding to VEGF receptors (VEGFRs). Here we report a novel peptide designated HRHTKQRHTALH (peptide HRH), which was isolated from the Ph.D. -12 phage display library using VEGFR-Fc fusion protein as the bait. This peptide was found to dose-dependently inhibit the proliferation of human umbilical vein endothelial cells stimulated by VEGF. The anti-angiogenesis effect of the HRH peptide was further confirmed in vivo using the chick chorioallantoic membrane assay, which was also dose-dependent. Besides, peptide HRH was proved to inhibit corneal neovascularization in an alkali-burnt rat corneal model and a suture-induced rat corneal model. Taken together, these findings suggest that the HRH peptide can inhibit angiogenesis both in vitro and in vivo. Consequently, the HRHTKQRHTALH peptide might be a promising lead peptide for the development of potential angiogenic inhibitors.

Current and Upcoming Therapies for Ocular Surface Chemical Injuries

Chemical injuries frequently result in vision loss, disfigurement, and challenging ocular surface complications. Acute interventions are directed at decreasing the extent of the injury, suppressing inflammation, and promoting ocular surface re-epithelialization. Chronically, management involves controlling inflammation along with rehabilitation and reconstruction of the ocular surface. Future therapies aimed at inhibiting neovascularization and promoting ocular surface regeneration should provide more effective treatment options for the management of ocular chemical injuries.

PEP-1-FK506BP inhibits alkali burn-induced corneal inflammation on the rat model of corneal alkali injury

FK506 binding protein 12 (FK506BP) is a small peptide with a single FK506BP domain that is involved in suppression of immune response and reactive oxygen species. FK506BP has emerged as a potential drug target for several inflammatory diseases. Here, we examined the protective effects of directly applied cell permeable FK506BP (PEP-1-FK506BP) on corneal alkali burn injury (CAI). In the cornea, there was a significant decrease in the number of cells expressing pro-inflammation, apoptotic, and angiogenic factors such as TNF-α, COX-2, and VEGF. Both corneal opacity and corneal neovascularization (CNV) were significantly decreased in the PEP-1-FK506BP treated group. Our results showed that PEP-1-FK506BP can significantly inhibit alkali burn-induced corneal inflammation in rats, possibly by accelerating corneal wound healing and by reducing the production of angiogenic factors and inflammatory cytokines. These results suggest that PEP-1-FK506BP may be a potential therapeutic agent for CAI. [BMB Reports 2015; 48(11): 618-623]

Role of heparin and non heparin binding serpins in coagulation and angiogenesis: A complex interplay

Pro-coagulant, anti-coagulant and fibrinolytic pathways are responsible for maintaining hemostatic balance under physiological conditions. Any deviation from these pathways would result in hypercoagulability leading to life threatening diseases like myocardial infarction, stroke, portal vein thrombosis, deep vein thrombosis (DVT) and pulmonary embolism (PE). Angiogenesis is the process of sprouting of new blood vessels from pre-existing ones and plays a critical role in vascular repair, diabetic retinopathy, chronic inflammation and cancer progression. Serpins; a superfamily of protease inhibitors, play a key role in regulating both angiogenesis and coagulation. They are characterized by the presence of highly conserved secondary structure comprising of 3 β-sheets and 7-9 α-helices. Inhibitory role of serpins is modulated by binding to cofactors, specially heparin and heparan sulfate proteoglycans (HSPGs) present on cell surfaces and extracellular matrix. Heparin and HSPGs are the mainstay of anti-coagulant therapy and also have therapeutic potential as anti-angiogenic inhibitors. Many of the heparin binding serpins that regulate coagulation cascade are also potent inhibitors of angiogenesis. Understanding the molecular mechanism of the switch between their specific anti-coagulant and anti-angiogenic role during inflammation, stress and regular hemostasis is important. In this review, we have tried to integrate the role of different serpins, their interaction with cofactors and their interplay in regulating coagulation and angiogenesis.

MK2 inhibitor reduces alkali burn-induced inflammation in rat cornea

MK2 activation by p38 MAPK selectively induces inflammation in various diseases. We determined if a MK2 inhibitor (MK2i), improves cornea wound healing by inhibiting inflammation caused by burning rat corneas with alkali. Our study, for the first time, demonstrated that MK2i inhibited alkali burn-induced MK2 activation as well as rises in inflammation based on: a) blunting rises in inflammatory index, inflammatory cell infiltration, ED1⁺ macrophage and PMN⁺ neutrophil infiltration; b) suppressing IL-6 and IL-1β gene expression along with those of macrophage inflammatory protein-1α (MIP-1α), intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1); c) reducing angiogenic gene expression levels and neovascularization (NV) whereas anti-angiogenic PEDF levels increased. In addition, this study found that MK2i did not affect human corneal epithelial cell (HCEC) proliferation and migration and had no detectable side effects on ocular surface integrity. Taken together, MK2i selectively inhibited alkali burn-induced corneal inflammation by blocking MK2 activation, these effects have clinical relevance in the treatment of inflammation related ocular surface diseases.

Therapeutic effects of topical netrin-4 in a corneal acute inflammatory model

AIM

To evaluate the therapeutic effect of netrin-4 on the early acute phase of inflammation in the alkali-burned eye.

METHODS

Eye drops containing netrin-4 or phosphate buffered saline (PBS) were administered to a alkali-burn-induced corneal acute inflammatory model four times daily. The clinical evaluations, including fluorescein staining and inflammatory index, were performed on day 1, 4 and 7 using slit lamp microscopy. Global specimens were collected on day 7 and processed for immunofluorescent staining. The levels of inflammatory mediators in the corneas were determined by real-time polymerase chain reaction (PCR).

RESULTS

Exogenous netrin-4 administered on rat ocular surfaces showed more improvements in decreasing fluorescein staining on day 4 and 7, and resolved alkali burn-induced corneal inflammation index on day 7 (P<0.01). The levels of IL-1β, IL-6, intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), monocyte chemotactic protein-1 (MCP-1) and macrophage inflammatory protein-1 (MIP-1) in corneas were decreased in netrin-4-treated groups (P<0.05). In addition, netrin-4 significantly reduced the expression of leukocyte common antigen 45 (CD45) in the alkali-burn cornea (P<0.001).

CONCLUSION

Topical netrin-4 accelerated wound healing and reduced the inflammation on alkali-burn rat model, suggesting a potential as an anti-inflammatory agent in the clinical to treat the acute inflammation.

Therapeutic effects of topical netrin-4 inhibits corneal neovascularization in alkali-burn rats

Netrins are secreted molecules involved in axon guidance and angiogenesis. However, the role of netrins in the vasculature remains unclear. Netrin-4 and netrin-1 have been found to be either pro- or antiangiogenic factors. Previously, we found that netrin-1 acts as an anti-angiogenic factor in rats by inhibiting alkali burn-induced corneal neovascularization. Here, we further investigate the effects of netrin-4, another member of the same netrin family, on neovascularization in vitro and in vivo. We found that netrin-4 functions similarly as netrin-1 in angiogenesis. In vitro angiogenesis assay shows that netrin-4 affected human umbilical vein endothelial cell (HUVEC) tube formation, viability and proliferation, apoptosis, migration, and invasion in a dose-dependent manner. Netrin-4 was topically applied in vivo to alkali-burned rat corneas on day 0 (immediately after injury) and/or day 10 post-injury. Netrin-4 subsequently suppressed and reversed corneal neovascularization. Netrin-4 inhibited corneal epithelial and stromal cell apoptosis, inhibited vascular endothelial growth factor (VEGF), but promoted pigment epithelium-derived factor (PEDF) expression, decreased NK-KB p65 expression, and inhibits neutrophil and macrophage infiltration. These results indicate that netrin-4 shed new light on its potential roles in treatmenting for angiogenic diseases that affect the ocular surface, as well as other tissues.

Nanoparticle-mediated expression of a Wnt pathway inhibitor ameliorates ocular neovascularization

OBJECTIVE

The deficiency of very low-density lipoprotein receptor resulted in Wnt signaling activation and neovascularization in the retina. The present study sought to determine whether the very low-density lipoprotein receptor extracellular domain (VLN) is responsible for the inhibition of Wnt signaling in ocular tissues.

APPROACH AND RESULTS

A plasmid expressing the soluble VLN was encapsulated with poly(lactide-co-glycolide acid) to form VLN nanoparticles (VLN-NP). Nanoparticles containing a plasmid expressing the low-density lipoprotein receptor extracellular domain nanoparticle were used as negative control. MTT, modified Boyden chamber, and Matrigel (™) assays were used to evaluate the inhibitory effect of VLN-NP on Wnt3a-stimulated endothelial cell proliferation, migration, and tube formation. Vldlr(-/-) mice, oxygen-induced retinopathy, and alkali burn-induced corneal neovascularization models were used to evaluate the effect of VLN-NP on ocular neovascularization. Wnt reporter mice (BAT-gal), Western blotting, and luciferase assay were used to evaluate Wnt pathway activity. Our results showed that VLN-NP specifically inhibited Wnt3a-induced endothelial cell proliferation, migration, and tube formation. Intravitreal injection of VLN-NP inhibited abnormal neovascularization in Vldlr(-/-), oxygen-induced retinopathy, and alkali burn-induced corneal neovascularization models, compared with low-density lipoprotein receptor extracellular domain nanoparticle. VLN-NP significantly inhibited the phosphorylation of low-density lipoprotein receptor-related protein 6, the accumulation of β-catenin, and the expression of vascular endothelial growth factor in vivo and in vitro.

CONCLUSIONS

Taken together, these results suggest that the soluble VLN is a negative regulator of the Wnt pathway and has antiangiogenic activities. Nanoparticle-mediated expression of VLN may thus represent a novel therapeutic approach to treat pathological ocular angiogenesis and potentially other vascular diseases affected by Wnt signaling.

Role of Protease-Inhibitors in Ocular Diseases

It has been demonstrated that the balance between proteases and protease-inhibitors system plays a key role in maintaining cellular and tissue homeostasis. Indeed, its alteration has been involved in many ocular and systemic diseases. In particular, research has focused on keratoconus, corneal wounds and ulcers, keratitis, endophthalmitis, age-related macular degeneration, Sorsby fundus dystrophy, loss of nerve cells and photoreceptors during optic neuritis both in vivo and in vitro models. Protease-inhibitors have been extensively studied, rather than proteases, because they may represent a therapeutic approach for some ocular diseases. The protease-inhibitors mainly involved in the onset of the above-mentioned ocular pathologies are: α2-macroglobulin, α1-proteinase inhibitor (α1-PI), metalloproteinase inhibitor (TIMP), maspin, SERPINA3K, SERPINB13, secretory leukocyte protease inhibitor (SLPI), and calpeptin. This review is focused on the several characteristics of dysregulation of this system and, particularly, on a possible role of proteases and protease-inhibitors in molecular remodeling that may lead to some ocular diseases. Recently, researchers have even hypothesized a possible therapeutic effect of the protease-inhibitors in the treatment of injured eye in animal models.

Signature microRNAs in human cornea limbal epithelium

This study was aimed to identify the signature microRNAs, which regulate the biological processes of corneal epithelial progenitor cell (CEPC) homeostasis and regulation through characterizing the differential expression profile of microRNAs in human limbal epithelium containing adult CEPC versus central corneal epithelium without CEPC. MicroRNA microarray had identified 37 microRNAs enriched in human corneal epithelium. Among them, nine were significantly upregulated in limbal epithelium and one in central corneal epithelium after validation by TaqMan® real-time polymerase chain reaction. In addition to our previous finding of miR-143 and 145, the expression of miR-10b, 126, and 155 was localized in limbal epithelium (LE) (predominantly basal layers) by using locked nucleic acid-based in situ hybridization. Potential target genes were predicted by TargetScan Human v6.0 and compared to the reported human cornea epithelial gene profile GSE5543. Analyzed by web-based Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and DAVID Functional Annotation Bioinformatics Resources v6.7, the downregulated genes were involved in pathways of immune response and cellular protection, apoptosis, and cell movement whereas upregulated genes with cell survival, cell-matrix interaction, and cell-cell adhesion. We found a constant occurrence of miR-143, 145, and 155 in all KEGG pathways regulating limbal epithelial events. By Ingenuity Systems (IPA®) analysis, these microRNAs could cooperatively regulate cell growth and apoptosis via tumor necrosis factor activation and MYC repression. Our findings thus suggest a unique microRNA signature existing in human limbal epithelium and participating in CEPC homeostasis.

SERPINA3K plays antioxidant roles in cultured pterygial epithelial cells through regulating ROS system

We recently demonstrated that SERPINA3K, a serine proteinase inhibitor, has antioxidant activity in the cornea. Here we investigated the antioxidant effects of SERPINA3K on the pterygial, which is partially caused by oxidative stress in pathogenesis. The head part of primary pterygial tissue was dissected and then cultured in keratinocyte serum-free defined medium (KSFM). The cultured pterygial epithelial cells (PECs) were treated with SERPINA3K. The cell proliferation and migration of PECs were measured and analyzed. Western blot and quantitative real-time polymerase chain reaction (PCR) assay were performed. It showed that SERPINA3K significantly suppressed the cell proliferation of PECs in a concentration-dependent manner, compared with cultured human conjunctival epithelial cells. SERPINA3K also inhibited the cell migration of PECs. Towards its underlying mechanism, SERPINA3K had antioxidant activities on the PECs by significantly inhibiting NADPH oxidase 4 (NOX4), which is an important enzyme of ROS generation, and by elevating the levels of key antioxidant factors of ROS: such as NAD(P)H dehydrogenase (quinone 1) (NQO1), NF-E2–related factor-2 (NRF2) and superoxide dismutases (SOD2). Meanwhile, SERPINA3K down-regulated the key effectors of Wnt signaling pathway: β-catenin, nonphospho-β-catenin, and low-density lipoprotein receptor-related protein 6 (LRP6). We provided novel evidence that SERPINA3K had inhibitory effects on pterygium and SERPINA3K played antioxidant role via regulating the ROS system and antioxidants.

Inhibition of pathological corneal neovascularization by a small peptide derived from human apolipoprotein (a) Kringle V

PURPOSE

The aim of this study was to evaluate the antiangiogenic activity of AU6, a novel 6-amino acid peptide derived from Kringle V of human apolipoprotein (a).

METHODS

RF/6A rhesus macaque choroid endothelial cells were used for in vitro studies. MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt] assays and modified Boyden chamber and Matrigel assays were used to evaluate the inhibitory effect of AU6 on vascular endothelial growth factor (VEGF)-stimulated endothelial cell functions, including cell proliferation, migration, and tube formation. The chick chorioallantoic membrane model, micropocket corneal neovascularization (CNV) model, and alkali burn CNV model were evaluated in vivo. Bevacizumab (Avastin), the VEGF-neutralizing antibody, and a scrambled peptide (AU6s) were used as positive and negative controls, respectively.

RESULTS

AU6 inhibited VEGF-induced RF/6A cell migration, proliferation, and tube formation. It also reduced pathological neovascularization in the chorioallantoic membrane model and in the 2 CNV models, that is, the mouse corneal micropocket model and the rat cornea alkali burn model.

CONCLUSIONS

AU6 effectively inhibited pathogenic CNV. This novel peptide shows potential as a new treatment for ocular neovascularization.

Transduced PEP-1-FK506BP ameliorates corneal injury in Botulinum toxin A-induced dry eye mouse model

FK506 binding protein 12 (FK506BP) belongs to a family of immunophilins, and is involved in multiple biological processes. However, the function of FK506BP in corneal disease remains unclear. In this study, we examined the protective effects on dry eye disease in a Botulinum toxin A (BTX-A) induced mouse model, using a cell-permeable PEP-1-FK506BP protein. PEP-1-FK506BP efficiently transduced into human corneal epithelial cells in a time- and dose-dependent manner, and remained stable in the cells for 48 h. In addition, we demonstrated that topical application of PEP-1-FK506BP was transduced into mouse cornea and conjunctiva by immunohistochemistry. Furthermore, topical application of PEP-1-FK506BP to BTX-A-induced mouse model markedly inhibited expression levels of pro-inflammatory cytokines such as interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and macrophage inhibitory factor (MIF) in corneal and conjunctival epithelium. These results suggest PEP-1-FK506BP as a potential therapeutic agent for dry eye diseases. [BMB Reports 2013; 46(2): 124-129]

Acidic/neutral amino acid residues substitution in NH2 terminal of plasminogen kringle 5 exerts enhanced effects on corneal neovascularization

PURPOSE

Recent results showed that plasminogen kringle 5 (K5) has improved inhibitory effect on human umbilical vein endothelial cells (HUVECs) viability when 5 acidic amino acids in NH2 terminal outside kringle domain were replaced by 5 serine residues (mutant K5, mK5). This study was designed to identify the enhanced antiangiogenic activity of mK5 in corneal neovascularization (CNV).

METHODS

Alkali burn-induced CNV was induced and treated with K5 and mK5 for 11 days. CNV and inflammation were evaluated by the CNV area and the inflammatory index, respectively. At the end of treatment, the corneas were removed for terminal deoxynucleotidyl transferase dUTP nick end labeling detection and immunohistochemistry. The effects of mK5 and K5 on HUVECs apoptosis were tested by MTT, BrdU, and flow cytometry. The expression levels of pigment epithelium-derived factor (PEDF) and vascular endothelial growth factor (VEGF) were detected by Western blot.

RESULTS

In a rat model of CNV induced by alkali, topical treatment with mK5 significantly decreased the neovascular area and inflammation compared with the wild-type K5-treated group. Meanwhile, mK5 and K5 specifically inhibited the HUVECs proliferation and induced vascular endothelial cell apoptosis in vitro and in vivo, and mK5 exerted higher apoptosis induction. Toward the mechanism of action, both mK5 and K5 significantly upregulated the expression of PEDF and mildly downregulated the expression of VEGF. The elevation of PEDF/VEGF ratio induced by mK5 was higher than that by K5.

CONCLUSIONS

These findings suggest that mK5 has more effective therapeutic potential in CNV than wild-type K5.

Topical administration of orbital fat-derived stem cells promotes corneal tissue regeneration

INTRODUCTION

Topical administration of eye drops is the major route for drug delivery to the cornea. Orbital fat-derived stem cells (OFSCs) possess an in vitro corneal epithelial differentiation capacity. Both the safety and immunomodulatory ability of systemic OFSC transplantation were demonstrated in our previous work. In this study, we investigated the safety, therapeutic effect, and mechanism(s) of topical OFSC administration in an extensive alkali-induced corneal wound.

METHODS

Corneal injury was created by contact of a piece of 0.5 N NaOH-containing filter paper on the corneal surface of a male Balb/c mouse for 30 s. The area of the filter paper covered the central 70% or 100% of the corneal surface. OFSCs (2 × 10(5)) in 5 μl phosphate-buffered saline (PBS) were given by topical administration (T) twice a day or by two intralimbal (IL) injections in the right cornea, while 5 μl of PBS in the left cornea served as the control.

RESULTS

Topical OFSCs promoted corneal re-epithelialization of both the limbal-sparing and limbal-involved corneal wounds. In the first three days, topical OFSCs significantly reduced alkali-induced corneal edema and stromal infiltration according to a histopathological examination. Immunohistochemistry and immunofluorescence staining revealed that transplanted cells were easily detectable in the corneal epithelium, limbal epithelium and stroma, but only some of transplanted cells at the limbal epithelium had differentiated into cytokeratin 3-expressing cells. OFSCs did not alter neutrophil (Ly6G) levels in the cornea, but significantly reduced macrophage (CD68) infiltration and inducible nitrous oxide synthetase (iNOS) production during acute corneal injury as quantified by a Western blot analysis. Continuous topical administration of OFSCs for seven days improved corneal transparency, and this was accompanied by diffuse stromal engraftment of transplanted cells and differentiation into p63-expressing cells at the limbal area. The therapeutic effect of the topical administration of OFSCs was superior to that of the IL injection. OFSCs from the IL injection clustered in the limbal area and central corneal epithelium, which was associated with a persistent corneal haze.

CONCLUSIONS

Topical OFSC administration is a simple, non-surgical route for stem cell delivery to promote corneal tissue regeneration through ameliorating acute inflammation and corneal epithelial differentiation. The limbal area serves as a niche for OFSCs differentiating into corneal epithelial cells in the first week, while the stroma is a potential site for anti-inflammation of OFSCs. Inhibition of corneal inflammation is related to corneal transparency.

Inhibition of corneal neovascularization with the combination of bevacizumab and plasmid pigment epithelium-derived factor-synthetic amphiphile INTeraction-18 (p-PEDF-SAINT-18) vector in a rat corneal experimental angiogenesis model

Bevacizumab, a 149-kDa protein, is a recombinant humanized monoclonal antibody to VEGF. PEDF, a 50-kDa glycoprotein, has demonstrated anti-vasopermeability properties. In this study, we demonstrated that the combination of bevacizumab and plasmid pigment epithelium-derived factor-synthetic amphiphile INTeraction-18 (p-PEDF-SAINT-18) has a favorable antiangiogenic effect on corneal NV. Four groups (Group A: 0 μg + 0 μg, B: 0.1 μg + 0.1 μg, C: 1 μg + 1 μg, and D: 10 μg + 10 μg) of bevacizumab + p-PEDF-SAINT-18 were prepared and implanted into the rat subconjunctival substantia propria 1.5 mm from the limbus on the temporal side. Then, 1 μg of p-bFGF-SAINT-18 was prepared and implanted into the rat corneal stroma 1.5 mm from the limbus on the same side. The inhibition of NV was observed and quantified from days 1 to 60. Biomicroscopic examination, western blot analysis and immunohistochemistry were used to analyze the 18-kDa bFGF, 50-kDa PEDF and VEGF protein expression. No inhibition activity for normal limbal vessels was noted. Subconjunctival injection with the combination of bevacizumab and p-PEDF-SAINT-18 successfully inhibited corneal NV. The bFGF and PEDF genes were successfully expressed as shown by western blot analysis, and a mild immune response to HLA-DR was shown by immunohistochemistry. We concluded that the combination of bevacizumab and p-PEDF-SAINT-18 may have more potent and prolonged antiangiogenic effects, making it possible to reduce the frequency of subconjunctival bevacizumab administration combined with a relatively safe profile and low toxicity.

Nanotechnology in corneal neovascularization therapy--a review

Nanotechnology is an up-and-coming branch of science that studies and designs materials with at least one dimension sized from 1-100 nm. These nanomaterials have unique functions at the cellular, atomic, and molecular levels. The term "nanotechnology" was first coined in 1974. Since then, it has evolved dramatically and now consists of distinct and independent scientific fields. Nanotechnology is a highly studied topic of interest, as nanoparticles can be applied to various fields ranging from medicine and pharmacology, to chemistry and agriculture, to environmental science and consumer goods. The rapidly evolving field of nanomedicine incorporates nanotechnology with medical applications, seeking to give rise to new diagnostic means, treatments, and tools. Over the past two decades, numerous studies that underscore the successful fusion of nanotechnology with novel medical applications have emerged. This has given rise to promising new therapies for a variety of diseases, especially cancer. It is becoming abundantly clear that nanotechnology has found a place in the medical field by providing new and more efficient ways to deliver treatment. Ophthalmology can also stand to benefit significantly from the advances in nanotechnology research. As it relates to the eye, research in the nanomedicine field has been particularly focused on developing various treatments to prevent and/or reduce corneal neovascularization among other ophthalmologic disorders. This review article aims to provide an overview of corneal neovascularization, currently available treatments, and where nanotechnology comes into play.

Cultivation and characterization of cornea limbal epithelial stem cells on lens capsule in animal material-free medium

A simple, reproducible, animal-material free method for cultivating and characterizing cornea limbal epithelial stem cells (LESCs) on human lens capsule (LC) was developed for future clinical transplantation. The limbal tissue explants (2×2×0.25 mm) were harvested from 77 cadavers and expanded ex vivo on either cell culture plates or LC in medium containing human serum as the only growth supplement. Cell outgrowth at the edge of the explants was observed within 24 hours of cultivation and achieved viable outgrowth (>97% viability as measured by MTT assay and flow cytometry) within two weeks. The outgrowing cells were examined by genome-wide microarray including markers of stemness (p63α, ABCG2, CK19, Vimentin and Integrin α9), proliferation (Ki-67), limbal epithelial cells (CK 8/18 and 14) and differentiated cornea epithelial cells (CK 3 and 12). Immunostaining revealed the non-hematopoietic, -endothelial and -mesenchymal stem cell phenotype of the LESCs and the localization of specific markers in situ. Cell adhesion molecules, integrins and lectin-based surface carbohydrate profiling showed a specific pattern on these cells, while colony-formation assay confirmed their clonal potency. The LESCs expressed a specific surface marker fingerprint (CD117/c-kit, CXCR4, CD144/VE-Cadherin, CD146/MCAM, CD166/ALCAM, and surface carbohydrates: WGA, ConA, RCA, PNA and AIL) which can be used for better localization of the limbal stem cell niche. In summary, we report a novel method combining the use of a medium with human serum as the only growth supplement with LC for cultivating, characterizing and expanding cornea LESCs from cadavers or alternatively from autologous donors for possible treatment of LESC deficiency.