Tumour-associated myeloid cells expressing IL-10R2/IL-22R1 as a potential biomarker for diagnosis and recurrence of pancreatic ductal adenocarcinoma.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with a poor survival rate, largely due to the lack of early diagnosis. Although myeloid cells are crucial in the tumour microenvironment, whether their specific subset can be a biomarker of PDAC progression is unclear. METHODS: We analysed IL-22 receptor expression in PDAC and peripheral blood. Additionally, we analysed gene expression profiles of IL-10R2+/IL-22R1+ myeloid cells and the presence of these cells using single-cell RNA sequencing and murine orthotropic PDAC models, respectively, followed by examining the immunosuppressive function of IL-10R2+/IL-22R1+ myeloid cells. Finally, the correlation between IL-10R2 expression and PDAC progression was evaluated. RESULTS: IL-10R2+/IL-22R1+ myeloid cells were present in PDAC and peripheral blood. Blood IL-10R2+ myeloid cells displayed a gene expression signature associated with tumour-educated circulating monocytes. IL-10R2+/IL-22R1+ myeloid cells from human myeloid cell culture inhibited T cell proliferation. By mouse models for PDAC, we found a positive correlation between pancreatic tumour growth and increased blood IL-10R2+/IL-22R1+ myeloid cells. IL-10R2+/IL-22R1+ myeloid cells from an early phase of the PDAC model suppressed T cell proliferation and cytotoxicity. IL-10R2+ myeloid cells indicated tumour recurrence 130 days sooner than CA19-9 in post-pancreatectomy patients. CONCLUSIONS: IL-10R2+/IL-22R1+ myeloid cells in the peripheral blood might be an early marker of PDAC prognosis.

Changes in Human Tear Proteome Following Topical Treatment of Dry Eye Disease: Cyclosporine A Versus Diquafosol Tetrasodium.

Purpose: To compare the changes in human tear proteome and clinical effects following topical cyclosporine A (CsA) 0.05% or diquafosol tetrasodium (DQS) 3% treatment of dry eye disease (DED), and to identify biomarkers for determining disease severity and treatment effectiveness in DED. Methods: A total of 18 patients were diagnosed with non-Sjögren DED. Nine patients in each group were treated with topical CsA 0.05% or DQS 3% for 4 weeks. Tear samples were collected after evaluation of tear breakup time, corneal and conjunctival erosion staining, and results of Schirmer's test 1 before and after treatment. Proteomes were characterized using liquid chromatography mass spectrometry, and proteins exhibiting a fold change >1.5 or <0.67 (P < 0.05) were considered differentially expressed (DEP). Results: A total of 794 proteins were identified, with no significant difference observed between pretreatment and posttreatment conditions. Proteomic analysis identified 54 and 106 DEPs between treatment groups (CsA and DQS, respectively), with gene ontology analysis indicating that both treatments enhanced innate and adaptive immune responses and cellular detoxification. Protein-network analysis showed that inflammation associated with the immune response was primarily responsible for the therapeutic process in both groups. Conclusions: These results provide insight into the broad scope of changes at the ocular surface in DED and indicated that although both drugs improved the clinical parameters, the activated tear-specific biomarkers differed significantly between treatments. Our findings suggest that the DEPs identified here and those correlated with the clinical parameters might represent candidate biomarkers for DED.

Comparison of Ocular Surface Mucin Expression After Topical Ophthalmic Drug Administration in Dry Eye-Induced Mouse Model.

PURPOSE: To determine the mucinogenic effect of dry eye (DE) treatment drugs currently in use, we compared the levels of mucin production and inflammatory cytokine expression on the ocular surfaces using a DE-induced mice model. METHODS: C57BL/6 mice were separated into 6 groups: a control group, DE-induced mice with the vehicle and treated with cyclosporine A (CsA), rebamipide (Reb), diquafosol tetrasodium (DQS), or prednisolone (Pred). The mRNA expression of MUC 1, 4, 16, 5AC, and proinflammatory cytokines on the corneal epithelia were determined by quantitative real-time polymerase chain reaction. Expression of each MUC was evaluated using flow cytometry and immunohistostaining. Conjunctival goblet cells were analyzed through periodic acid-Schiff (PAS) staining. RESULTS: Desiccating stress significantly decreased both mRNA and protein levels of all MUCs in the cornea. CsA mainly enhanced MUC5AC, with an increase in PAS-positive cells, whereas DQS chiefly increased membrane-associated mucins (MM). However, Reb only minimally increased expression of MUC5AC and Pred only increased MUC4. MUC16 did not show any significant change in any group. On the contrary, the mRNA levels of interleukin (IL)-1ß, -6, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ were increased in the DE corneas of the control mice and were reduced by all treatments; in particular, IL-6 was significantly suppressed. CONCLUSION: Topical DQS and CsA not only ameliorated ocular surface inflammation under desiccating stress but also upregulated both MM and secretory mucins (SM) and contributed to conjunctival goblet cell recovery, compared to Reb and Pred. Both anti-inflammatory and secretory factors should be considered simultaneously when measuring the treatment effect of DE drugs.

Downregulation of IL-7 and IL-7R Reduces Membrane-Type Matrix Metalloproteinase 14 in Granular Corneal Dystrophy Type 2 Keratocyte.

Purpose: Granular corneal dystrophy type 2 (GCD2) is caused by a point mutation (R124H) in the TGF-ß-induced gene (TGFBI). However, the mechanisms underlying the accumulation of TGF-ß-induced protein (TGFBIp) are poorly understood. Therefore, we evaluated the signaling cascade affecting the expression of TGFBIp using patient-derived cells. Methods: Keratocyte primary cultures were prepared from corneas from the eye bank or from heterozygous or homozygous patients with GCD2 after penetrating or lamellar keratoplasty. GCD2 diagnoses were based on the results of a DNA analysis for the R124H TGFßI mutation. Keratocytes were treated with various cytokines and then analyzed using quantitative PCR (qPCR) array, qPCR, flow cytometry, ELISA, and Western blotting. Results: TGFBI expression was counterregulated by IL-7 in corneal fibroblasts. IL-7 expression was significantly reduced in corneal fibroblasts from patients with GCD2. TGF-ß and TGFBI expression were reduced on IL-7 treatment in corneal fibroblasts. Interestingly, the interplay between TGF-ß and IL-7 was regulated by the RANKL/RANK signaling cascade. Also, IL-7 regulates the expression of a membrane-type matrix metalloproteinase (MT-MMP), which plays a crucial role in migration and neovascularization in the cornea. Conclusions: These studies demonstrate that impaired IL-7 expression in patients with GCD2 affects disease pathogenesis via a failure to control TGF-ß expression. The RANKL/RANK axis regulates TGF-ß and TGFBI expression via IL-7-mediated MT-MMP regulation in corneal fibroblasts. These findings improve our understanding of the pathogenesis of GCD2.

Corneal lymphangiogenesis facilitates ocular surface inflammation and cell trafficking in dry eye disease.

PURPOSE: While the normal cornea has limited innervation by the lymphatic system, chronic immune-inflammatory disorders such as dry eye (DE) can induce lymphangiogenesis in the ocular surface. Using a conditional knock-down murine model, Lyve-1Cre;VEGFR2flox mice, this study investigated the role of lymphangiogenesis in the pathophysiology of DE. METHODS: DE was induced in both wild type (WT) B6 and Lyve-1Cre;VEGFR2flox mice. Tissue immunostaining and volumetric gross measurements were used to assess changes in the ocular surface, skin, and lymph nodes (LNs). The expression of lymphangiogenic factors (TNF-α, IL-6/-8/-12/-17, VEGF-C/-D, IFN-γ, VEGFR-2/-3, Lyve-1, and podoplanin) and the frequency of immune cells (CD4, CD11b, and CD207) on the ocular surface and lacrimal glands were quantified by real-time polymerase chain reaction and flow cytometry. RESULTS: Compared to WT mice, there were fewer lymphatic vessels and a reduction in lymphangiogenic markers in the ocular surface and skin of Lyve-1Cre;VEGFR2flox mice. After DE induction, mRNA levels of TNF-α, IL-8, and IFN-γ were significantly reduced in Lyve-1Cre;VEGFR2flox mice compared to WT mice (p < .01). Surprisingly, the LNs from Lyve-1Cre;VEGFR2flox mice with DE were significantly smaller and populated by fewer dendritic cells and effector T cells than those from WT mice (p < .001). Furthermore, immunostaining showed corneal nerves in the DE-induced Lyve-1Cre;VEGFR2flox mice were notably intact like in the naïve condition. CONCLUSIONS: Inhibition of lymphangiogenesis in the cornea effectively attenuates not only the inflammatory response including trafficking of immune cells but also preserves corneal nerves under desiccating stress. Corneal lymphangiogenesis might be a contributing factor in deterioration on the ocular surface homeostasis.

Langerhans cells prevent subbasal nerve damage and upregulate neurotrophic factors in dry eye disease.

The functional role of Langerhans cells (LCs) in ocular surface inflammation and nerve damage in dry eye (DE) disease has yet to be determined. This study was performed to investigate this relationship through both clinical study on DE patients and in vivo mouse models with induced DE disease. In a cross-sectional case-control study (54 eyes of DE patients; 34 eyes of control patients), average cell density, area, and process length of LCs were measured using confocal microscopy. Data were analyzed to determine whether changes in LCs are correlated with subbasal nerve plexus (SNP) parameters (nerve density, beading, and tortuosity). In DE patients, SNP density marginally decreased and nerve beading and tortuosity were significantly increased compared to the control group. The total number of LCs significantly increased in DE patients, and some LCs with elongated processes were found to be attached to nerve fibers. Interestingly, nerve loss and deformation were correlated with inactivation of LCs. In an in vivo experiment to elucidate the role of LCs in ocular surface inflammation and corneal nerve loss, we used a genetically modified mouse model (CD207-DTR) that reduced the population of CD207 (Langerin) expressing cells by injection of diphtheria toxin. In CD207-depleted mice with DE disease (CD207-dDTR+DE), corneal nerves in the central region were significantly decreased, an effect that was not observed in wild-type (WT)+DE mice. In CD207-dDTR+DE mice, infiltration of CD4+, CD19+, CD45+, and CD11b+ cells into the ocular surface was increased, as confirmed by flow cytometry. Increased IL-17 and IFN-γ mRNA levels, and decreased expression of neurotrophic factors and neurotransmitters, were also found in the CD207-dDTR+DE mice. These data support a functional role for LCs in negatively regulating ocular surface inflammation and exhibiting a neuroprotective function in DE disease.

The Effect of TNF-α Blocker HL036337 and Its Best Concentration to Inhibit Dry Eye Inflammation.

PURPOSE: Dry eye syndrome is commonly thought of as an inflammatory disease, and we have previously presented data showing the effectiveness of topical TNF-α blocker agents for the treatment of this condition. The purpose of this study was to investigate the effectiveness of the TNF-α blocking agent HL036337 compared to cyclosporine A for the treatment of dry eye induced inflammation in order to establish whether HL036337 represents a more effective method for suppressing inflammation. The efficacy of HL036337 and cyclosporine A was determined using an experimental murine dry eye model. METHODS: The TNF-α blocker HL036337 is a modified form of TNF receptor I. Using dry eye induced C57BL/6 mice (n = 45), corneal erosion was measured at day 4 and 7 after topical treatment with cyclosporine A or HL036337. To determine the effective treatment dose, 0.25, 0.5, 1, 2.5, and 5 mg/mL of HL036337 were topically administered twice per day to dry eye induced murine corneas for 1 week. RESULTS: The optimal concentration of the TNF-α blocker HL036337 for treatment of dry eye induced corneal erosion was determined to be 1 mg/mL. Dry eye induced corneal erosion was improved after 1 week with topically applied cyclosporine A and HL036337 at 1 mg/mL. CONCLUSIONS: HL036337 administered topically at 1 mg/mL effectively improved corneal erosion induced by dry eye. This finding may also suggest that inhibition of TNF-α can improve dry eye syndrome.

Gr-1intCD11b+ myeloid-derived suppressor cells accumulate in corneal allograft and improve corneal allograft survival.

We identified the characteristics of myeloid-derived suppressor cells (MDSCs) and investigated their mechanism of induction and their functional role in allograft rejection using a murine corneal allograft model. In mice, MDSCs coexpress CD11b and myeloid differentiation antigen Gr-1. Gr-1+CD11b+ cells infiltrated allografted corneas between 4 d and 4 wk after surgery; however, the frequencies of Gr-1+CD11b+ cells were not different between accepted and rejected allografts or in peripheral blood or BM. Of interest, Gr-1intCD11b+ cells, but not Gr-1hiCD11b+ cells, infiltrated the accepted graft early after surgery and expressed high levels of immunosuppressive cytokines, including IL-10, TGF-ß, and TNF-related apoptosis-inducing ligand. This population remained until 4 wk after surgery. In vitro, only high dose (>100 ng/ml) of IFN-γ plus GM-CSF could induce immunosuppressive cytokine expression in Gr-1intCD11b+ cells. Furthermore, adoptive transfer of Gr-1intCD11b+ cells reduced T cell infiltration, which improved graft survival. In conclusion, high-dose IFN-γ in allograft areas is essential for development of Gr-1intCD11b+ MDSCs in corneal allografts, and subtle environmental changes in the early period of the allograft can result in a large difference in graft survival.

Activation of Dll4/Notch Signaling and Hypoxia-Inducible Factor-1 Alpha Facilitates Lymphangiogenesis in Lacrimal Glands in Dry Eye.

PURPOSE: By using hypoxia-inducible factor-1 alpha conditional knockout (HIF-1α CKO) mice and a dry eye (DE) mouse model, we aimed to determine the role played by delta-like ligand 4 (Dll4)/Notch signaling and HIF-1α in the lymphangiogenesis of lacrimal glands (LGs). METHODS: C57BL/6 mice were housed in a controlled-environment chamber for DE induction. During DE induction, the expression level of Dll4/Notch signaling and lymphangiogenesis in LGs was measured by quantitative RT-PCR, immunoblot, and immunofluorescence staining. Next, lymphangiogenesis was measured after Dll4/Notch signal inhibition by anti-Dll4 antibody or γ-secretase inhibitor. Using HIF-1α CKO mice, the expression of Dll4/Notch signaling and lymphangiogenesis in LGs of DE-induced HIF-1α CKO mice were assessed. Additionally, the infiltration of CD45+ cells in LGs was assessed by immunohistochemical (IHC) staining and flow cytometry for each condition. RESULTS: DE significantly upregulated Dll4/Notch and lymphangiogenesis in LGs. Inhibition of Dll4/Notch significantly suppressed lymphangiogenesis in LGs. Compared to wild-type (WT) mice, DE induced HIF-1α CKO mice showed markedly low levels of Dll4/Notch and lymphangiogenesis. Inhibition of lymphangiogenesis by Dll4/Notch suppression resulted in increased CD45+ cell infiltration in LGs. Likewise, CD45+ cells infiltrated more in the LGs of HIF-1α CKO DE mice than in non-DE HIF-1α CKO mice. CONCLUSIONS: Dll4/Notch signaling and HIF-1α are closely related to lymphangiogenesis in DE-induced LGs. Lymphangiogenesis stimulated by Dll4/Notch and HIF-1α may play a role in protecting LGs from DE-induced inflammation by aiding the clearance of immune cells from LGs.

Dry eye-induced CCR7+CD11b+ cell lymph node homing is induced by COX-2 activities.

PURPOSE: We aimed to determine the role of CCR7+CD11b+ cell lymph node (LN) homing and T-cell differentiation in dry eye (DE)-induced immunopathogenesis and investigate the therapeutic effects of cyclooxygenase-2 (COX-2) and prostaglandin E2/eicosanoid-prostanoid (PGE2/EP) inhibitors against DE. METHODS: Six-week-old female C57BL/6 mice were housed in a controlled-environment chamber and administered topical selective COX-2 inhibitors or EP2 antagonists. Expression of major histocompatibility complex (MHC)-IIhigh, CD11b+, CCR7+, IFN-γ+, IL-17+, and CD4+ in the corneas and draining LNs was evaluated using flow cytometry. Mixed lymphocyte reactions (MLRs) with carboxyfluorescein diacetate succinimidyl ester labeling and intracellular cytokine staining were used to verify DE-induced corneal dendritic cell function. mRNA expression of COX-2, EPs, and proinflammatory cytokines in ocular surface was evaluated using quantitative RT-PCR and immunohistochemical staining. RESULTS: Dry eye significantly increased MHC-IIhighCD11b+ and CCR7+CD11b+ cells in the cornea and LNs, and MLR revealed CCR7+CD11b+ cells from DE corneas stimulated IL-17+CD4+ cell proliferation. mRNA levels of COX-2, EP2, IFN-γ, TNF-α, IL-6, and IL-17 were significantly higher in DE ocular surface but were suppressed by topical COX-2 inhibitors and EP2-specific blockers. Immunohistochemical staining showed COX-2 and matrix metalloproteinase expression in DE corneal epithelia that was diminished by both topical treatments. Furthermore, both topical treatments significantly reduced frequencies of MHC-IIhigh, CD11b+, and CCR7+CD11b+ cells in the corneas and LNs, but also IL-17+CD4+ cells in LNs. CONCLUSIONS: Topical COX-2/EP2 treatment reduces CCR7+CD11b+ cells on the ocular surface with inhibition of cellular LN homing and suppresses Th17 immune response, suggesting the COX-2/PGE2/EP axis contributes to immuno-inflammatory pathogenesis on the ocular surface and may be a novel therapeutic target in DE.

Anti-hyperlipidemic Effect of Polyphenol Extract (Seapolynol(™)) and Dieckol Isolated from Ecklonia cava in in vivo and in vitro Models.

The inhibitory effect of polyphenol extracts (Seapolynol(™), SPN) of the marine brown algae Ecklonia cava and dieckol, a major component of SPN, on hyperlipidemia was investigated in ICR mice fed a high-fat diet (HFD) for five weeks. For analysis of the anti-hyperlipidemic effects of SPN and dieckol, these two agents were given orally on a daily basis to HFD-fed mice for four weeks, starting one week after the beginning of HFD feeding. Groups administered with SPN as well as dieckol showed lower body weight gains than the HFD only group. Administration of SPN and dieckol also resulted in a significant reduction of the level of total cholesterol (TCHO), triglyceride (TG), and low-density lipoprotein (LDL) cholesterol in the serum of HFD-fed mice. In Oil Red O staining using 3T3-L1 preadipocytes, it was shown that both SPN and dieckol markedly inhibited lipid accumulation of 3T3-L1 cells. Furthermore, SPN and dieckol (50 µg/mL) significantly inhibited 3-hydroxyl-methyl glutaryl coenzyme A (HMGCoA) reductase activity in vitro. Taken together, these results suggest that polyphenols of Ecklonia cava (SPN) and dieckol reduce body weight gain and fat accumulation in HFD-induced obese mice, and that their hypolipidemic effect is related to the inhibition of adipogenesis of adipocytes and HMGCoA reductase activity.