Diclofenac Protects Cultured Human Corneal Epithelial Cells Against Hyperosmolarity and Ameliorates Corneal Surface Damage in a Rat Model of Dry Eye

Modeling dry eye with an air-liquid interface in corneal epithelium-on-a-chip

Dry eye syndrome (DES) is a complex ocular condition characterized by an unstable tear film and inadequate tear production, leading to tissue damage. Despite its common occurrence, there is currently no comprehensive in vitro model that accurately reproduce the cellular characteristics of DES. Here we modified a corneal epithelium-on-a-chip (CEpOC) model to recapitulate DES by subjecting HCE-T human corneal epithelial cells to an air-liquid (AL) interface stimulus. We then assessed the effects of AL stimulation both in the presence and absence of diclofenac (DCF), non-steroidal anti-inflammatory drug. Transcriptomic analysis revealed distinct gene expression changes in response to AL and AL_DCF, affecting pathways related to development, epithelial structure, inflammation, and extracellular matrix remodeling. Both treatments upregulated PIEZO2, linked to corneal damage signaling, while downregulating OCLN, involved in cell-cell junctions. They increased the expression of inflammatory genes (e.g., IL-6) and reduced mucin production genes (e.g., MUC16), reflecting dry eye characteristics. Metabolomic analysis showed increased secretion of metabolites associated with cell damage and inflammation (e.g., methyl-2-oxovaleric acid, 3-methyl-2-oxobutanoic acid, lauroyl-carnitine) in response to AL and even more with AL_DCF, indicating a shift in cellular metabolism. This study showcases the potential use of AL stimulus within the CEpOC to induce cellular characteristics relevant to DES.

Inflammation mechanism and anti-inflammatory therapy of dry eye

Dry eye is a widespread chronic inflammatory disease that causes fatigue, tingling, burning, and other symptoms. Dry eye is attributed to rheumatic diseases, diabetes, hormone disorders, and contact lenses, which activate inflammatory pathways: mitogen-activated protein kinases (MAPK) and nuclear factor-B (NF-κB), promote macrophage inflammatory cell and T cell activation, and inflammation factors. Clinicians use a combination of anti-inflammatory drugs to manage different symptoms of dry eye; some of these anti-inflammatory drugs are being developed. This review introduces the dry eye inflammation mechanisms and the involved inflammatory factors. We also elucidate the anti-inflammatory drug mechanism and the detection limits.

NLRP3 Inflammasome as a Potential Therapeutic Target in Dry Eye Disease

Dry eye disease (DED) is a multifactorial ocular surface disorder arising from numerous interrelated underlying pathologies that trigger a self-perpetuating cycle of instability, hyperosmolarity, and ocular surface damage. Associated ocular discomfort and visual disturbance contribute negatively to quality of life. Ocular surface inflammation has been increasingly recognised as playing a key role in the pathophysiology of chronic DED. Current readily available anti-inflammatory agents successfully relieve symptoms, but often without addressing the underlying pathophysiological mechanism. The NOD-like receptor protein-3 (NLRP3) inflammasome pathway has recently been implicated as a key driver of ocular surface inflammation, as reported in pre-clinical and clinical studies of DED. This review discusses the intimate relationship between DED and inflammation, highlights the involvement of the inflammasome in the development of DED, describes existing anti-inflammatory therapies and their limitations, and evaluates the potential of the inflammasome in the context of the existing anti-inflammatory therapeutic landscape as a therapeutic target for effective treatment of the disease.

Correlation Study Between Abnormal Morphology of Meibomian Glands and Meibum in Patients With Dry Eye Disease Under in vivo Confocal Microscopy

Objective: To observe differences in meibomian gland morphology among patients with meibomian gland dysfunction (MGD) with liquid meibum, with solid meibum, and a non-MGD group by laser scanning in vivo confocal microscopy (IVCM), and then analyze the correlation between meibomian gland abnormalities and dry eye disease. Methods: Twenty-one patients with MGD (42 eyes) with liquid meibum, 21 patients with MGD (38 eyes) with solid meibum, and 24 non-MGD patients (39 eyes) were enrolled in the study. IVCM examination and Schirmer II test were performed, and non-invasive tear-film breakup time (NIBUT) was measured. Results: Data obtained from all the patients were normally distributed; therefore, one-way analysis of variance was performed. The meibomian gland opening diameter and gland opening area of the patients with MGD were greater than those of the non-MGD patients, and values of the liquid meibum group were greater than those of the solid meibum group (F = 17.96, p < 0.001; F = 8.84, p < 0.001, respectively). Due to changes in meibomian gland opening diameter and dilation of meibomian gland acini, the acinar longest diameter and unit area of the patients with MGD were also greater than those of the non-MGD patients, and the values of the solid meibum group were greater than those of the liquid meibum group (F = 36.52, p < 0.001; F = 27.81, p < 0.001, respectively). In the aspect of acinar shortest diameter, there was no difference among the three groups (F = 0.24, P > 0.05). Highest inflammatory cell density was observed in the solid meibum group, followed by the liquid meibum group, and the non-MGD group (F = 111.54, p < 0.001). Similarly, the results of the Schirmer II test and NIBUT showed that the condition of the patients with MGD in the solid meibum group was worst, followed by that of the liquid meibum group and the non-MGD group (F = 99.57, p < 0.001; F = 11.87, p < 0.001, respectively). Conclusions: The different meibum in the patients with MGD is accompanied by different meibomian gland morphologies. Compared with the patients with liquid meibum, those with solid meibum have more obvious dilatation of meibomian glands under confocal microscopy and in these patients, the density of inflammatory cells among glands is higher, and the quality of tears is worse.

Thermogels containing sulfated hyaluronan as novel topical therapeutics for treatment of ocular surface inflammation

The development of long lasting therapeutic agents is critically important for efficient treatment of chronic diseases. We herein report a rational strategy to develop a therapeutic thermogel featured with prolonged anti-inflammatory and corneal-protective effects. Specifically, a hyaluronic acid with different sulfation degrees and an amine-terminated poly(N-isopropylacrylamide) are conjugated to achieve the thermogels. In vitro studies reveal that the thermogels are highly biocompatible to statens seruminstitut rabbit cornea cells and their anti-inflammatory properties are strongly dependent on the sulfation degree. In a rabbit model of ocular inflammation, single-dose topical administration of a thermogel formulation could repair defects in corneal epithelium (∼99% thickness restored), prevent corneal cell apoptosis (∼68.3% cells recovered), and suppress ocular surface inflammation (∼4-fold decrease) for a follow-up period of 7 days. This high treatment efficacy of the thermogel can be attributed to its potent inhibition in selectin-mediated leukocyte infiltration as well as effective corneal protection. These findings show a great promise for topical treatment of ocular inflammation and advancement of ophthalmic formulations using the bioactive thermogel as a therapeutic component that is not rapidly cleared from the eye and thus considerably reduces administration times.

•

Sulfated hyaluronan thermogels served as intrinsic therapeutic agents.

•

Thermogels exert inhibitory effects on selectin-mediated leukocyte infiltration.

•

Sulfation degree is a key to achieve superior therapeutic thermogels.

•

Highly sulfated agent reveals potent anti-inflammatory/corneal-protective effects.

•

Single dose reduces corneal inflammation by 4-folds at 7 days post-instillation.

Trends in Topical Prescriptional Therapy for Old Patients With Dry Eye Disease in Six Major Areas of China: 2013-2019

The prevalence of dry eye disease (DED) in old patients are high, corresponding to a substantial economic burden. In this cross-sectional study, we analyzed the trends in the topical prescriptional treatment of old patients with DED in six major areas of China. Information on topical drug prescriptions for DED patients aged above 60 years was extracted from the Hospital Prescription Analysis Cooperative Program of China database. Trends in yearly prescriptions and cost were analyzed. The data were further stratified by patient age and sex, drug class, and specific drug. A total of 130,734 prescriptions from 52 hospitals located in six major areas of China were analyzed. The number of prescripptions per year for patients with DED increased from 13,308 in 2013 to 22,074 in 2019, with a corresponding increase in cost of all topical drugs from 1,490,014 Chinese Yuan (CNY) to 2,618,206 CNY. Drugs for the treatment of DED accounted for the largest proportion of the total cost in each year. Ocular lubricants were the main pharmacotherapy agent. Sodium hyaluronate use increased over time, and the drug was used by 65.9% of patients by the end of the study. Pranoprofen was the second most frequently used drug. The most frequently used drugs for co-incident disease were antimicrobials. Treatment patterns for DED haven’t changed, and the most frequently used drug combination was sodium hyaluronate and pranoprofen. In summary, prescription for old patients with DED and the cost of treatment are increasing. Ocular lubricants are the main treatment option, while sodium hyaluronate is the most frequently used drug. The observed trends can lead to more efficient allocation of health care resources in China.

Structure based peptide design, molecular dynamics and MM-PBSA studies for targeting C terminal dimerization of NFAT5 DNA binding domain

NFAT5 as a transcription factor with an established role in osmotic stress response, has also been revealed to be active under numerous settings, including pathological conditions such as diabetic microvascular complications, chronic arthritis and cancer. Despite these links, current strategies for downregulating NFAT5 activity only relies on indirect modulators, not directly targeting NFAT5, itself. With this study, through using a computational approach, an original peptide was explored to directly target C terminal dimerization of NFAT5 RHR, located in its DNA binding domain. At first, homodimeric NFAT5 RHR bound to its consensus DNA was used for prediction of a preliminary peptide sequence. Possible amino acid replacements for this preliminary peptide were predicted for optimization, which was followed by addition of a cell penetrating peptide sequence. These attempts yielded a small peptide library, which was further investigated for peptide affinities towards C terminal of NFAT5 RHR through molecular docking, 50 ns and 250 ns molecular dynamics simulations, followed by estimation of MM-PBSA based relative binding free energies. Results indicated that after receiving mutations on the preliminary peptide sequence for optimization, a unique peptide could target C terminal dimerization region of NFAT5 RHR through using its cell penetrating peptide sequence. In conclusion, this is the first study presenting computational evidence on identification of a novel peptide capable of directly targeting NFAT5 dimerization. Besides, future implications of these observations were also discussed in terms of methodology and possible applications.

Imprinted hydrogels with LbL coating for dual drug release from soft contact lenses materials

A combined strategy to control the release of two drugs, one anti-inflammatory (diclofenac sodium, DCF) and one antibiotic (moxifloxacin hydrochloride, MXF), from a soft contact lens (SCL) material, was assessed. The material was a silicone-based hydrogel, which was modified by molecular imprinting with MXF and coated by the layer-by-layer (LbL) method using natural polyelectrolytes: alginate (ALG), poly-l-lysine (PLL) and hyaluronate (HA), crosslinked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). Imprinting was used to increase the amount of MXF loaded and to sustain its release, while the LbL coating acted as a diffusion barrier for DCF and improved the surface properties. The drugs were loaded by soaking in a DCF + MXF dual solution. High hydrostatic pressure (HHP) was successfully applied in the sterilization of the drug-loaded hydrogels. The transmittance, refractive index, wettability and ionic permeability of the hydrogels remained within the required levels for SCLs application. The concentrations of the released DCF and MXF stayed above the IC₅₀ and the MIC (for S. aureus and S. epidermidis) values, for 9 and 10 days, respectively. No ocular irritancy was detected by the HET-CAM test. NIH/3T3 cell viability demonstrated that the drug-loaded hydrogels were not toxic, and cell adhesion was reduced.

Long-acting mucoadhesive thermogels for improving topical treatments of dry eye disease

Dry eye disease (DED) is the most common ocular disorder that causes persistent discomfort and blurry vision in patients. Despite pharmacotherapy strategies, the current topical administration of eye drops remains a great challenge owing to their low bioavailability and short residence time. Herein, we demonstrate an effective topical treatment of DED via rational design of a long-acting and mucoadhesive drug delivery system. Specifically, the drug carrier is a chemically ternary material system consisting of gelatin that serves as an enzyme-mediated degradable matrix, poly(N-isopropylacrylamide) as a thermo-responsive regulator, and lectin Helix pomatia agglutinin as a mucus-binding component. The long-acting drug release performance is exploited via initiator effects during the synthesis of the thermo-responsive polymer, while the mucoadhesive feature is inherited from the mucus-binding material. In a rabbit model of DED, a pharmacotherapy based on one-time topical administration of epigallocatechin gallate-loaded carrier onto the cul-de-sac could effectively repair the defective corneal epithelium via mitigating cellular inflammation, oxidative stress, and cell apoptosis for a sustained period over 14 days. These findings on the initiator and synergy effects in the development of the advanced ophthalmic formulation show great promise for efficient management of complex ocular diseases by a simple topical administration route.

Potential Role of Gene Regulator NFAT5 in the Pathogenesis of Diabetes Mellitus

Nuclear factor of activated T cells 5 (NFAT5), a Rel/nuclear factor- (NF-) κB family member, is the only known gene regulator of the mammalian adaptive response to osmotic stress. Exposure to elevated glucose increases the expression and nuclear translocation of NFAT5, as well as NFAT5-driven transcriptional activity in vivo and in vitro. Increased expression of NFAT5 is closely correlated with the progression of diabetes in patients. The distinct structure of NFAT5 governs its physiological and pathogenic roles, indicating its opposing functions. The ability of NFAT5 to maintain cell homeostasis and proliferation is impaired in patients with diabetes. NFAT5 promotes the formation of aldose reductase, pathogenesis of diabetic vascular complications, and insulin resistance. Additionally, NFAT5 activates inflammation at a very early stage of diabetes and induces persistent inflammation. Recent studies revealed that NFAT5 is an effective therapeutic target for diabetes. Here, we describe the current knowledge about NFAT5 and its relationship with diabetes, focusing on its diverse regulatory functions, and highlight the importance of this protein as a potential therapeutic target in patients with diabetes.

Idebenone has preventative and therapeutic effects on pulmonary fibrosis via preferential suppression of fibroblast activity

Alveolar epithelial injury induced by reactive oxygen species (ROS) and abnormal collagen production by activated fibroblasts (myofibroblasts) is involved in the onset and exacerbation of idiopathic pulmonary fibrosis (IPF). Compared with alveolar epithelial cells, lung fibroblasts, especially myofibroblasts, exhibit an apoptosis-resistance phenotype (apoptosis paradox) that appears to be involved in IPF pathogenesis. Thus, we screened for chemicals eliciting preferential cytotoxicity of LL29 cells (lung fibroblasts from an IPF patient) compared with A549 cells (human lung alveolar epithelial cell line) from medicines already in clinical use. We identified idebenone, a synthetic analogue of coenzyme Q10 (CoQ₁₀, an antioxidant) that has been used clinically as a brain metabolic stimulant. Idebenone induced cell growth inhibition and cell death in LL29 cells at a lower concentration than in A549 cells, a feature that was not observed for other antioxidant molecules (such as CoQ₁₀) and two IPF drugs (pirfenidone and nintedanib). Administration of idebenone prevented bleomycin-induced pulmonary fibrosis and increased pulmonary ROS levels. Importantly, idebenone also improved pulmonary fibrosis and lung function when administered after the development of fibrosis, whereas administration of CoQ₁₀ similarly prevented bleomycin-induced pulmonary fibrosis, but had no effect after its development. Administration of idebenone, but not CoQ₁₀, suppressed bleomycin-induced increases in lung myofibroblasts. In vitro, treatment of LL29 cells with idebenone, but not CoQ₁₀, suppressed TGF-β–induced collagen production. These results suggest that in addition to antioxidant activity, idebenone exerts inhibitory activity on the function of lung fibroblasts, with the former activity being preventative and the latter therapeutic for bleomycin-induced fibrosis. Thus, we propose that idebenone may be more therapeutically beneficial for IPF patients than current treatments.

Alpha-Lipoic Acid Ameliorates Radiation-Induced Lacrimal Gland Injury through NFAT5-Dependent Signaling

Dry eye syndrome related to radiation therapy is relatively common and can severely impair a patient’s daily life. The nuclear factor of activated T cells 5(NFAT5) is well known for its osmoprotective effect under hyperosmolar conditions, and it also has immune-modulating functions. We investigated the role of NFAT5 and the protective effect of α-lipoic acid(ALA) on radiation-induced lacrimal gland (LG) injuries. Rats were assigned to control, ALA only, radiation only, and ALA administered prior to irradiation groups. The head and neck area, including the LG, was evenly irradiated with 2 Gy/minute using a photon 6-MV linear accelerator. NFAT5 expression was enhanced and localized in the LG tissue after irradiation and was related to cellular apoptosis. ALA had a protective effect on radiation-induced LG injury through the inhibition of NFAT5 expression and NFAT5-dependent signaling pathways. Functional radiation–induced damage of the LG and cornea was also restored with ALA treatment. NFAT5 expression and its dependent signaling pathways were deeply related to radiation-induced dry eye, and the condition was improved by ALA treatment. Our results suggest a potential role of NFAT5 and NF-κB in the proinflammatory effect in LGs and cornea, which offers a target for new therapies to treat dry eye syndrome.

Dry Eye Disease: Emerging Approaches to Disease Analysis and Therapy

Dry eye disease (DED) is among the most common ocular disorders affecting tens of millions of individuals worldwide; however, the condition remains incompletely understood and treated. Valuable insights have emerged from multidisciplinary approaches, including immunometabolic analyses, microbiome analyses, and bioengineering. Furthermore, we have seen new developments in clinical assessment approaches and treatment strategies in the recent past. Here, we review the emerging frontiers in the pathobiology and clinical management of DED.

Dynamics, ultrastructure and gene expression of human in vitro organized testis cells from testicular sperm extraction biopsies

STUDY QUESTION

Is it possible to induce in vitro reorganization of primary human testis cells from testicular sperm extraction (TESE) biopsies, maintain their long-term cultivation in a 2D system and identify cellular compositions?

SUMMARY ANSWER

In vitro reorganization of primary human testis cells from TESE biopsies and their long-term cultivation on uncoated cell culture dishes is feasible and the cellular compositions can be uncovered through gene expression and microscopic analyses.

WHAT IS KNOWN ALREADY

It has been shown in the rodent model that mixtures of testicular cell types are able to reassemble into clusters when cultivated on different kinds of surfaces or three-dimensional matrices. Two recent publications demonstrated the ability of primary human testicular cells to assemble into testicular organoids and their cultivation for a period of 3-4 weeks.

STUDY DESIGN SIZE, DURATION

Primary human testis cells from TESE biopsies from 16 patients were reorganized in vitro and the clusters were cultivated long term on uncoated cell culture dishes, providing a solid ground for in vitro spermatogenesis. Gene expression analysis as well as fluorescence/transmission electron microscopy (TEM) were employed to uncover the cellular composition of the clusters.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Testis biopsies from adult, normogonadotropic patients displaying full spermatogenesis (n = 11), hypospermatogenesis (n = 2), predominantly full spermatogenesis with some hypospermatogenic tubules (n = 1), meiotic arrest (n = 1) or mixed atrophy (n = 1) were enzymatically digested and dispersed cells were cultivated on 96-well plates or chamber dishes as aggregate-free cell suspensions. Time-lapse imaging of cluster formation was performed over a period of 48 h. For receptor tyrosine kinase inhibition of cluster formation, cells were treated twice with K252a within 2-3 days. Immunofluorescence staining and confocal microscopy was carried out on clusters after 1-3 weeks of cultivation to identify the presence of Sertoli cells (SC) (SOX9), peritubular myoid cells (SMA), Leydig cells (LC) (STAR), undifferentiated spermatogonia (FGFR3), differentiating spermatogonia/spermatocytes (DDX4) and postmeiotic germ cells (PRM1). Single clusters from four patients and a pool of eight larger clusters from another patient were manually picked and subjected to quantitative real-time PCR to evaluate the presence of SC (SOX9, AR), LC (INSL3, STAR, HSD3B1), peritubular myoid cells (ACTA2), fibroblasts (FSP1), endothelial cells (CD34), macrophages (CD68), undifferentiated spermatogonia (FGFR3), differentiating spermatogonia/spermatocytes (DDX4) and postmeiotic germ cells (PRM1). Finally, an ultrastructural investigation was conducted based on TEM of clusters from six different patients, among them 3-month cultivated large clusters from two patients.

MAIN RESULTS AND THE ROLE OF CHANCE

Quantitative PCR-based analysis of single-picked testicular cell clusters identified SC, peritubular myoid cells, endothelial cells, fibroblasts, macrophages, spermatids and LC after 1, 2 or 3 weeks or 3 months of cultivation. Immunofluorescence positivity for SC and peritubular myoid cells corroborated the presence of these two kinds of testis niche cells. In addition, round as well as elongated spermatids were frequently encountered in 1 and 2 weeks old clusters. Transmission electron microscopical classification confirmed all these cell types together with a few spermatogonia. Macrophages were found to be of the proinflammatory M1 subtype, as revealed by CD68+/CD163-/IL6+ expression. Time-lapse imaging uncovered the specific dynamics of cluster fusion and enlargement, which could be prevented by addition of protein kinase inhibitor K252a.

LARGE SCALE DATA

N/A.

LIMITATIONS REASON FOR CAUTION

Cell composition of the clusters varied based on the spermatogenic state of the TESE patient. Although spermatids could be observed with all applied methods, spermatogonia were only detected by TEM in single cases. Hence, a direct maintenance of these germ cell types by our system in its current state cannot be postulated. Moreover, putative dedifferentiation and malignant degeneration of cells in long-term cluster cultivation needs to be investigated in the future.

WIDER IMPLICATIONS OF THE FINDINGS

This work demonstrates that the reorganization of testicular cells can be achieved with TESE biopsies obtained from men enroled in a standard clinical assisted reproduction program. The formed clusters can be cultivated for at least 3 months and are composed, to a large extent, of the most important somatic cell types that are essential to support spermatogenesis. These findings may provide the cellular basis for advances in human in vitro spermatogenesis and/or the possibility for propagation of spermatogonia within a natural stem cell niche-like environment.

STUDY FUNDING AND COMPETING INTERESTS

The project was funded by a DFG grant to K.v.K. (KO 4769/2-1). The authors declare they have no conflicts of interest.

Epigallocatechin Gallate-Loaded Gelatin-g-Poly(N-Isopropylacrylamide) as a New Ophthalmic Pharmaceutical Formulation for Topical Use in the Treatment of Dry Eye Syndrome

Given that biodegradable in situ gelling delivery systems may have potential applications in the design of ophthalmic pharmaceutical formulations, this study, for the first time, aims to develop gelatin-g-poly(N-isopropylacrylamide) (GN) carriers for topical epigallocatechin gallate (EGCG) administration in the treatment of dry eye disease (DED). By temperature triggered sol-gel phase transition of copolymers, EGCG-loaded GN was prepared at 32 °C and characterized by FTIR, NMR, and HPLC analyses. Results of WST-1 and live/dead assays showed that GN materials have good compatibility with corneal epithelial cells. Gradual biodegradation of delivery carriers allowed sustained release of EGCG without drug toxicity. Anti-inflammatory and antioxidant activity studies also indicated effective therapeutic drug levels at each time point within 3 days of release. In a rabbit dry eye model, corneal epithelial defects was ameliorated by treatment with single-dose administration of EGCG-containing GN. Furthermore, drug molecules released from carrier materials could prevent further tear evaporation and loss of mucin-secreting goblet cells in diseased animals. Our findings suggest that GN carrier is responsible for enhanced pharmacological efficacy of topically instilled EGCG, thereby demonstrating the benefits of using biodegradable in situ gelling delivery system to overcome the drawbacks of limited dry eye relief associated with eye drop dosage form.

Protective and therapeutic effect of felodipine against bleomycin-induced pulmonary fibrosis in mice

Idiopathic pulmonary fibrosis (IPF) involves alveolar epithelial injury and abnormal collagen production caused by activated fibroblasts; transforming growth factor (TGF)-β1 is implicated in this activation. In this study, we screened for chemicals capable of inhibiting TGF-β1-induced collagen production in cultured fibroblasts from medicines already in clinical use. We selected felodipine based on its extent of collagen production inhibition, clinical safety profile, and other pharmacological activity. Felodipine is a dihydropyridine Ca²⁺ channel blocker that has been used clinically to treat patients with high blood pressure. Felodipine suppressed collagen production within LL29 cells in the presence of TGF-β1, but not in its absence. Intratracheal administration of felodipine prevented bleomycin-induced pulmonary fibrosis, alteration of lung mechanics and respiratory dysfunction. Felodipine also improved pulmonary fibrosis, as well as lung and respiratory function when administered after fibrosis development. Furthermore, administration of felodipine suppressed a bleomycin-induced increase in activated fibroblasts in the lung. We also found other dihydropyridine Ca²⁺ channel blockers (nifedipine and benidipine) inhibited collagen production in vitro and partially prevented bleomycin-induced pulmonary fibrosis, alteration of lung mechanics and respiratory dysfunction in vivo. We propose that these Ca²⁺ channel blockers may be therapeutically beneficial for IPF patients.

Suppression of NFAT5-mediated Inflammation and Chronic Arthritis by Novel κB-binding Inhibitors

Nuclear factor of activated T cells 5 (NFAT5) has been implicated in the pathogenesis of various human diseases, including cancer and arthritis. However, therapeutic agents inhibiting NFAT5 activity are currently unavailable. To discover NFAT5 inhibitors, a library of > 40,000 chemicals was screened for the suppression of nitric oxide, a direct target regulated by NFAT5 activity, through high-throughput screening. We validated the anti-NFAT5 activity of 198 primary hit compounds using an NFAT5-dependent reporter assay and identified the novel NFAT5 suppressor KRN2, 13-(2-fluoro)-benzylberberine, and its derivative KRN5. KRN2 inhibited NFAT5 upregulation in macrophages stimulated with lipopolysaccharide and repressed the formation of NF-κB p65-DNA complexes in the NFAT5 promoter region. Interestingly, KRN2 selectively suppressed the expression of pro-inflammatory genes, including Nos2 and Il6, without hampering high-salt-induced NFAT5 and its target gene expressions. Moreover, KRN2 and KRN5, the latter of which exhibits high oral bioavailability and metabolic stability, ameliorated experimentally induced arthritis in mice without serious adverse effects, decreasing pro-inflammatory cytokine production. Particularly, orally administered KRN5 was stronger in suppressing arthritis than methotrexate, a commonly used anti-rheumatic drug, displaying better potency and safety than its original compound, berberine. Therefore, KRN2 and KRN5 can be potential therapeutic agents in the treatment of chronic arthritis.

•

We identify a novel NFAT5 suppressor KRN2, 13-(2-fluoro)-benzylberberine, and its derivative KRN5 to inhibit NFAT5 activity.

•

KRN2 inhibits the transcriptional activation of NFAT5 and the pro-inflammatory responses.

•

KRN2 and KRN5 suppress experimentally induced arthritis in mice.

NFAT5 has been implicated in the pathogenesis of arthritis. However, therapeutic agents specifically inhibiting NFAT5 activity are currently unavailable. To discover NFAT5 inhibitors, a library of > 40,000 chemicals was screened, leading to the discovery of novel berberine-based NFAT5 suppressors, KRN2 and its oral derivative KRN5. KRN2 inhibited the transcriptional activation of NFAT5 by blocking NF-κB binding to the NFAT5 promoter region, thereby reducing the expression of pro-inflammatory genes. Moreover, KRN2 and KRN5 ameliorated experimentally induced arthritis in mice without serious adverse effects. Therefore, we propose that KRN2 and KRN5 may be potential therapeutic agents in the treatment of chronic arthritis.

A Transporter of Ibuprofen is Upregulated in MDCK I Cells under Hyperosmotic Culture Conditions

Ibuprofen is a widely used drug. It has been identified as an inhibitor of several transporters, but it is not clear if ibuprofen is a substrate of any transporter itself. In the present work, we have characterized a transporter of ibuprofen, which is upregulated by hyperosmotic culture conditions in Madin-Darby canine kidney I (MDCK I) renal cells. [(3)H]-Ibuprofen uptake rate was measured in MDCK I cell cultured under normal (300 mOsm) and hyperosmotic (500 mOsm) conditions. Hyperosmotic conditions were obtained by supplementing urea, NaCl, mannitol, or raffinose to culture medium. The effect of increased osmolarity was investigated for different incubation times. [(3)H]-Ibuprofen uptake in MDCK I cells was upregulated by hyperosmotic culture condition, and was saturable with a Km value of 0.37 ± 0.08 μM and a Vmax of 233.1 ± 17.2 pmol· cm(-2)· min(-1). Racemic [(3)H]-ibuprofen uptake could be inhibited by (R)-(-)- and (S)-(+)-ibuprofen with IC50 values of 19 μM (Log IC50 1.39 ± 0.34) and 0.47 μM (Log IC50 -0.36 ± 0.41), respectively. Furthermore, the [(3)H]-ibuprofen uptake rate was increased by decreased extracellular pH but not dependent on Na(+) or Cl(-) ions. The mRNA of Mct1, -2, -4, and -6 as well as Oat1 and -3 were not upregulated by hyperosmolarity. Our findings present strong evidence for the presence of a yet unknown ibuprofen transporter in MDCK I cells. The transporter was upregulated under hyperosmotic culture conditions, and the present study is therefore a starting point for identification of the molecular correlate and potential impact on ibuprofen disposition.

Comparison of effect of nepafenac and diclofenac ophthalmic solutions on cornea, tear film, and ocular surface after cataract surgery: the results of a randomized trial

Background

The aim of this study was to compare the effects of nepafenac ophthalmic suspension 0.1% (Nevanac) and diclofenac sodium ophthalmic solution 0.1% (Diclod) on the cornea, tear film, and ocular surface after cataract surgery.

Methods

A total of 60 eyes (60 patients) were selected for this study, with no ocular diseases other than cataract (scheduled for cataract surgery by one surgeon). Patients were randomly enrolled to receive nepafenac or diclofenac in the perioperative period, and cataract surgery was performed using torsional microcoaxial phacoemulsification and aspiration with intraocular lens implantation via a transconjunctival single-plane sclerocorneal incision at the 12 o’clock position. We compared intra- and intergroup differences preoperatively and postoperatively in conjunctival and corneal fluorescein staining scores, tear film breakup times, Schirmer’s tests, the Dry Eye Related Quality of Life Scores, and tear meniscus areas using anterior segment optical coherence tomography.

Results

The diclofenac group had significantly higher conjunctival and corneal fluorescein staining scores at 4 weeks postoperatively compared with the nepafenac group (P<0.001). Within the diclofenac group, significantly higher conjunctival and corneal fluorescein staining scores were noted at 4 weeks postoperatively than those seen preoperatively (P<0.001) and at 1 week postoperatively (P<0.001). No statistically significant differences were found in any other items.

Conclusions

Nepafenac ophthalmic suspension 0.1% is considered safe for the corneal epithelium after cataract surgery.

Ibuprofen transport in renal cell cultures: characterization of an ibuprofen transporter upregulated by hyperosmolarity

An ibuprofen transporter localizes to the apical and basolateral membrane of MDCK I cells is upregulated by hyperosmotic exposure. Ibuprofen uptake is inhibited by other NSAIDs and ibuprofen metabolites.

Lipid-Based Therapy for Ocular Surface Inflammation and Disease

Ocular surface diseases such as dry eye, allergic keratoconjunctivitis, and infection are very prevalent conditions and involve ocular surface stress and inflammation. Recently, various lipid-based therapies have been advocated for the modulation of ocular surface inflammation. Here we review the latest developments and challenges of these strategies. These include administration of essential fatty acids, cyclooxygenase (COX) inhibitors and resolvin analogs. Lipids form part of the tear film and are crucial for tear film stability; loss of tear film stability can aggravate ocular surface inflammation. Strategies to replenish tear film lipids - namely, eyelid warming and eye drops containing natural or synthetic lipids - are evaluated. Recent advances in the use of lipids as ocular drug delivery vehicles, antioxidants, and diagnostic markers are discussed.

Corneal sensitivity following lacrimal gland excision in the rat

PURPOSE

Dry eye disease (DED) produces ocular pain and irritation, yet a detailed characterization of ocular sensitivity in a preclinical model of DED is lacking. The aim of the present study was to assess nociceptive behaviors in an aqueous tear deficiency model of DED in the rat.

METHODS

Spontaneous blinking, corneal mechanical thresholds, and eye wipe behaviors elicited by hypertonic saline (5.0 M) were examined over a period of 8 weeks following the unilateral excision of either the exorbital lacrimal gland or of the exorbital and infraorbital lacrimal glands, and in sham surgery controls. The effect of topical proparacaine on spontaneous blinking and of systemic morphine (0.5-3.0 mg/kg, subcutaneous [SC]) on spontaneous blinking and eye wipe responses were also examined.

RESULTS

Lacrimal gland excision resulted in mechanical hypersensitivity and an increase in spontaneous blinking in the ipsilateral eye over an 8-week period that was more pronounced after infra- and exorbital gland excision. The time spent eye wiping was also enhanced in response to hypertonic saline (5.0 M) at both 1- and 8-week time-points, but only in infra- and exorbital gland excised animals. Morphine attenuated spontaneous blinking, and the response to hypertonic saline in dry eye animals and topical proparacaine application reduced spontaneous blinking down to control levels.

CONCLUSIONS

These results indicate that aqueous tear deficiency produces hypersensitivity in the rat cornea. In addition, the increase in spontaneous blinks and their reduction by morphine and topical anesthesia indicate the presence of persistent irritation elicited by the activation of corneal nociceptors.

Global Metabonomic and Proteomic Analysis of Human Conjunctival Epithelial Cells (IOBA-NHC) in Response to Hyperosmotic Stress

"Dry eye" is a multifactorial inflammatory disease affecting the ocular surface. Tear hyperosmolarity in dry eye contributes to inflammation and cell damage. Recent research efforts on dry eye have been directed toward biomarker discovery for diagnosis, response to treatment, and disease mechanisms. This study employed a spontaneously immortalized normal human conjunctival cell line, IOBA-NHC, as a model to investigate hyperosmotic stress-induced changes of metabolites and proteins. Global and targeted metabonomic analyses as well as proteomic analysis were performed on IOBA-NHC cells incubated in serum-free media at 280 (control), 380, and 480 mOsm for 24 h. Twenty-one metabolites and seventy-six iTRAQ-identified proteins showed significant changes under at least one hyperosmotic stress treatment as compared with controls. SWATH-based proteomic analysis further confirmed the involvement of inflammatory pathways such as prostaglandin 2 synthesis in IOBA-NHC cells under hyperosmotic stress. This study is the first to identify glycerophosphocholine synthesis and O-linked β-N-acetylglucosamine glycosylation as key activated pathways in ocular surface cells under hyperosmotic stress. These findings extend the current knowledge in metabolite markers of dry eye and provide potential therapeutic targets for its treatment.

The dendrimer paradox – high medical expectations but poor clinical translation

This review was written with the intention to critically evaluate the status of dendrimers as drug carriers and find answers as to why this class of compounds has not translated into the clinic despite 40 years of research.

Hyperosmolar tears enhance cooling sensitivity of the corneal nerves in rats: possible neural basis for cold-induced dry eye pain

PURPOSE

Tear hyperosmolarity is a ubiquitous feature of dry-eye disease. Although dry-eye patients' sensitivity to cooling is well known, the effects of tear hyperosmolarity on a small amount of cooling in the corneal nerves have not been quantitatively examined. Recently reported corneal afferents, high-threshold cold sensitive plus dry-sensitive (HT-CS + DS) neurons, in rats is normally excited by strong (>4°C) cooling of the cornea, which, when applied to healthy humans, evokes the sensation of discomfort. However, corneal cooling measured between blinks does not exceed 2°C normally. Thus, we sought to determine if these nociceptors could be sensitized by hyperosmolar tears such that they are now activated by small cooling of the ocular surface.

METHODS

Trigeminal ganglion neurons innervating the cornea were extracellularly recorded in isoflurane-anesthetized rats. The responses of single corneal neurons to cooling stimuli presented in the presence of hyperosmolar (350-800 mOsm NaCl) tears were examined.

RESULTS

The HT-CS + DS neurons with thresholds averaging 4°C cooling responded to cooling stimuli presented after 15 minutes of hyperosmolar tears with thresholds of less than 1°C. The response magnitudes also were enhanced so that the responses to small (2°C) cooling emerged, where none was observed before.

CONCLUSIONS

These results demonstrate that after exposure to hyperosmolar tears, these nociceptive corneal neurons now begin to respond to the slight cooling normally encountered between blinks, enabling the painful information to be carried to the brain, which could explain the cooling-evoked discomfort in dry eye patients.