Disrupted mitochondrial transcription factor A expression promotes mitochondrial dysfunction and enhances ocular surface inflammation by activating the absent in melanoma 2 inflammasome.

PURPOSE: Severe dry eye disease causes ocular surface damage, which is highly associated with mitochondrial dysfunction. Mitochondrial transcription factor A (TFAM) is essential for packaging mitochondrial DNA (mtDNA) and is crucial for maintaining mitochondrial function. Herein, we aimed to explore the effect of a decreased TFAM expression on ocular surface damage. METHODS: Female C57BL/6 mice were induced ocular surface injury by topical administrating benzalkonium chloride (BAC). Immortalized human corneal epithelial cells (HCECs) were stimulated by tert-butyl hydroperoxide (t-BHP) to create oxidative stress damage. HCECs with TFAM knockdown were established. RNA sequencing was employed to analyze the whole-genome expression. Mitochondrial changes were measured by transmission electron microscopy, Seahorse metabolic flux analysis, mitochondrial membrane potential, and mtDNA copy number. TFAM expression and inflammatory cytokines were determined using RT-qPCR, immunohistochemistry, immunofluorescence, and immunoblotting. RESULTS: In both the corneas of BAC-treated mice and t-BHP-induced HCECs, we observed impaired TFAM expression, accompanied by mitochondrial structure and function defects. TFAM downregulation in HCECs suppressed mitochondrial respiratory capacity, reduced mtDNA content, induced mtDNA leakage into the cytoplasm, and led to inflammation. RNA sequencing revealed the absent in melanoma 2 (AIM2) inflammasome was activated in the corneas of BAC-treated mice. The AIM2 inflammasome activation was confirmed in TFAM knockdown HCECs. TFAM knockdown in t-BHP-stimulated HCECs aggravated mitochondrial dysfunction and the AIM2 inflammasome activation, thereby further triggering the secretion of inflammatory factors such as interleukin (IL) -1ß and IL-18. CONCLUSIONS: TFAM reduction impaired mitochondrial function, activated AIM2 inflammasome and promoted ocular surface inflammation, revealing an underlying molecular mechanism for ocular surface disorders.

Rho-kinase inhibitor alleviates CD4+T cell mediated corneal graft rejection by modulating its STAT3 and STAT5 activation.

Penetrating keratoplasty remains the most common treatment to restore vision for corneal diseases. Immune rejection after corneal transplantation is one of the major causes of graft failure. In recent years, Rho-associated protein kinase (ROCK) inhibitors have been found to be associated with the activation of the STATs pathway and are widely studied in autoimmune diseases. Therefore, it may be possible that the ROCK inhibitors also participate in the local and systemic immune regulation in corneal transplantation through activation of the STATs pathway and affect the CD4+ T cell differentiation. This study aimed to explore the role of ROCK-STATs pathway in the occurrence of immune rejection in corneal transplantation by applying Y27632, a ROCK inhibitor, to the recipient mice and peripheral CD4+ T cells. We found that Y27632 significantly up-regulated the phosphorylation level of STAT5 in both spleen and lymph nodes, down-regulated the phosphorylation level of STAT3 in the CD4+ T cells in the spleen. It also increased the proportion of CD4+CD25+Foxp3+Helios+ Tregs while decreased CD4+IL17A+ -Th17 cells. Moreover, Y27632 also reduced the proportion of dendritic cells in both spleen and lymph nodes, as well as the expression level of CD86 on their surfaces in the spleen, while the proportion of macrophages was not affected. The expression levels of ROCK1, ROCK2, CD11c and IL-17A mRNA were also found to be low in the graft tissue while the expression of Helios was upregulated. Rho-kinase inhibitor can modulate the balance of Tregs/Th17 by regulating the phosphorylation levels of both STAT3 and STAT5, thereby inhibiting the occurrence of immune rejection in allogeneic corneal transplantation.

Gp130 Promotes Inflammation via the STAT3/JAK2 Pathway in Allergic Conjunctivitis.

Purpose: Allergic conjunctivitis (AC) is a common allergic condition worldwide that requires accurate screening and early diagnosis. We found that gp130 is essential for AC, as gp130 levels are elevated in AC. Therefore, this study aimed to elucidate the functions and the possible underlying mechanisms of gp130 in AC. Methods: To compare mRNA expression profiles, the conjunctival tissues of BALB/c mice with ovalbumin (OVA)-induced AC were subjected to RNA-sequencing (RNA-seq) analysis followed by bioinformatic analysis. A nonrandomized study involving 57 patients with AC and 24 sex- and age-matched healthy individuals was conducted. A protein chip was used to detect cytokine levels in patient tears. Differentially expressed proteins in patient serum were detected using label-free quantitative mass spectrometry. Histamine-stimulated conjunctival epithelial cells (HConEpiCs) were used to construct a cell model. LMT-28 which can inhibit gp130 phosphorylation was dropped onto the murine ocular surface, and the resulting symptoms were observed. Results: Gp130 is upregulated in the conjunctival tissues of OVA-induced mice, the serum and tears of patients, and the histamine-stimulated HConEpiCs. Signal transducer and activator of transcription 3 (STAT3) and Janus kinase 2 (JAK2) were upregulated in the conjunctival tissues of mice with OVA-induced AC and in HConEpiCs. Ocular surface inflammation was significantly relieved in LMT-28-treated mice. The expression of IgE, IL-4, IL-5, and IL-13 in serum of LMT-28-treated mice decreased. The number of mast cells in conjunctival tissue was decreased compared with OVA-induced mice. Conclusions: Gp130 may play an important role in AC via the gp130/JAK2/STAT3 pathway. Inhibiting gp130 phosphorylation alleviates ocular surface inflammation in mice, presenting a potential treatment approach for AC.

Mechanosensitive channel Piezo1 is an essential regulator in cell cycle progression of optic nerve head astrocytes.

Optic nerve head (ONH) astrocytes provide structural and metabolic support to neuronal axons in developmental, physiological, and pathological progression. Mechanosensitive properties of astrocytes allow them to sense and respond to mechanical cues from the local environment. We confirmed that ONH astrocytes express the mechanosensitive ion channel Piezo1 in vivo. By manipulating Piezo1 knockdown or overexpression in vitro, we found that Piezo1 is necessary but insufficient for ONH astrocyte proliferation. Loss of Piezo1 can lead to cell cycle arrest at G0/G1 phase, a possible mechanism involving decreased yes-associated protein (YAP) nuclear localization and downregulation of YAP-target cell cycle-associated factors, including cyclin D1 and c-Myc. Gene ontology enrichment analysis of differential expression genes from RNA-seq data indicates that the absence of Piezo1 affects biological processes involving cell division. Our results demonstrate that Piezo1 is an essential regulator in cell cycle progression in ONH astrocytes.

TIGIT-Fc Prolongs Corneal Allograft Survival in Mice by Upregulating TIGIT/CD226 Expression and the Proportion of Helios + Foxp3 + Treg Cells.

BACKGROUND: Reduction of graft rejection remains key issue for supporting long-term graft retention after corneal transplantation. The relevance of Treg in reduction of corneal allografts rejection has been demonstrated. It has been recently reported that in addition to Foxp3, Helios is also considered to be a marker of activated Treg. Helios + Foxp3 + Treg are considered to be the true immunosuppressive Treg. TIGIT is an immunosuppressive costimulatory molecule that was found to be highly expressed on the surface of Helios + Foxp3 + Treg. METHODS: In this study, we aimed to explore whether supplementing TIGIT would result in an expansion and activation of Helios + Foxp3 + Treg thus to mediate an immune tolerance following corneal transplantation by administering topically and systemically TIGIT-Fc treatment in murine models. RESULTS: TIGIT-Fc treatment significantly improved the survival of corneal allograft compared with the control group. TIGIT-Fc treatment increased TIGIT/CD226 expression, the proportion of Helios + Foxp3 + Treg cells and an enhanced ex vivo suppressive effect from peripheral lymph nodes isolated Treg cells. Furthermore, the expression of Helios in corneal grafts was upregulated, whereas expression of CD226 and production of aqueous interferon-γ and VEGF were reduced by TIGIT-Fc treatment. CONCLUSIONS: TIGIT-Fc treatment could specifically upregulate Helios + Foxp3 + Treg-mediated immune response after allogeneic corneal transplantation via TIGIT/CD226-CD155 pathway which improves the survival of allografts.

Isotretinoin Impairs the Secretory Function of Meibomian Gland Via the PPARγ Signaling Pathway.

Purpose: To investigate the effects of isotretinoin on the ocular surface and to explore the possible mechanisms. Methods: Rats were treated with isotretinoin 20 mg/kg/d for five months and tested monthly for tear secretion, fluorescein staining, and infrared photography. After five months of treatment, tissues were harvested for routine staining to evaluate the morphological changes; and real-time polymerase chain reaction, Western blot, and immunohistochemistry to study the expression of associated genes and their products such as forkhead box protein O1 (FoxO1), forkhead box protein O3, peroxisome proliferator-activated receptor γ (PPARγ), adipose differentiation-related protein, elongation of very long chain fatty acids protein 4, fatty acid binding protein 4, matrix metalloproteinase-9, and interleukin-6. Results: Systemically, isotretinoin-treated rats have a significantly lower body weight that controls and apparent skin damage. Locally, although there was no alteration in tear secretion, a significant corneal involvement indicated by increased fluorescein staining scores, and also the contrast of meibomian gland was significantly reduced but no significant atrophy of the acinus was found. In addition, isotretinoin causes a decrease in conjunctival goblet cells. Furthermore, isotretinoin treatment did not cause the upregulation of FoxO1 and inflammation related genes but significantly suppressed the expression of PPARγ pathway. Conclusions: Isotretinoin does not cause a significant atrophy of the acinus and a significant change of FoxO1 expression in the meibomian gland. Isotretinoin causes meibomian gland dysfunction, affecting meibocyte differentiation and qualitative and quantitative changes in the meibum, through PPARγ pathway.

Demodex folliculorum Infestation in Meibomian Gland Dysfunction Related Dry Eye Patients.

Objective: To report the influence of Demodex folliculorum (D. folliculorum) infestation in patients with meibomian gland dysfunction (MGD) related dry eye and the associations of the infestation with MGD related dry eye. Methods: Eyelashes (three from the upper eyelid and three from the lower eyelid) from 119 eyes of 119 patients diagnosed with MGD related dry eye were examined under a light microscope. There were 68 eyes of 68 patients with MGD related dry eye and D. folliculorum infestation (Demodex positive group) and 51 eyes of 51 patients without infestation (Demodex negative group). All patients completed an Ocular Surface Disease Index (OSDI) questionnaire and underwent tests for dry eye and MGD. The tests included fluorescein tear breakup time (TBUT), corneal fluorescein staining, Schirmer I test (SIT), lid margin abnormalities, meibum expression assessment, and meibomian gland dropout. Results: The scores for OSDI, corneal fluorescein staining, lid margin abnormalities, meibum expression, and meibomian gland dropout were significantly higher (all P < 0.05), while TBUT was significantly shorter in the Demodex positive group compared to the Demodex negative group (P = 0.020). The SIT values did not significantly differ between groups. Chalazion was significantly more prevalent in the Demodex positive group. The number of D. folliculorum was positively correlated with all three MGD parameters (P ≤ 0.035), OSDI; corneal fluorescein scores, and it was inversely correlated with BUT. The correlation for SIT was R 2 = 0.075 (P = 0.064). Conclusion: Demodex folliculorum infestation is possibly one of the key contributors in the pathogenesis of MGD related dry eye, and a higher prevalence of chalazion was found in D. folliculorum infected patients. The possible causal role of D. folliculorum infestation needs to be further studied.

Total IgE in tears accurately reflects the severity and predicts the prognosis of seasonal allergic conjunctivitis.

BACKGROUND: Although immunoglobulin E (IgE) increases significantly in tears and serum during seasonal allergic conjunctivitis (SAC), it is unclear whether tear total IgE can reflect the severity and prognosis of SAC more accurately than serum total IgE. We aimed to investigate the usefulness of measuring the total IgE in tears to evaluate the severity and determine the treatment of SAC. METHODS: This prospective, nonrandomized study involved 55 patients with SAC and 10 age- and sex-matched healthy controls. Serum and tears were collected before and after treatment to analyze the total IgE. SAC patients received the same topical anti-allergy treatment and were followed-up every 2 weeks for 1 month. The relationship of tear and serum total IgE concentrations with pollen concentrations and symptom severity before and after treatment was assessed. RESULTS: The total IgE concentration in tears was higher in SAC patients than in healthy participants with significant correlations between tear and serum total IgE concentrations. The total IgE concentration in tears, but not in serum, correlated with the pollen concentration and severity of ocular symptoms and reactions in SAC. Treatment-associated improvements in symptoms and reactions in SAC correlated with decreased concentrations of the tear total IgE. Patients with disease recurrence following treatment demonstrated significantly higher tear total IgE concentrations than patients with no recurrence. CONCLUSION: The total tear IgE level can indicate the severity and predict the prognosis of SAC more accurately than the serum total IgE.

Assessment of Eyelid Pressure Using a Novel Pressure Measurement Device in Patients With Moderate-to-Severe Dry Eye Disease.

OBJECTIVE: To assess a novel eyelid pressure measurement device and study the relationship between eyelid pressure and ocular surface parameters of moderate-to-severe dry eye disease (DED). METHODS: The present study included 70 eyes of 35 moderate-to-severe DED patients. All subjects were subjected to the following examinations for DED assessment: Ocular Surface Disease Index (OSDI) questionnaire, tear meniscus height (TMH), lipid layer thickness (LLT), number of partial blink (PB), total blink (TB) and partial blink rate (PBR), fluorescein tear breakup time (FBUT), corneal fluorescein staining (CFS), lid margin abnormality, meibum expression assessment (meibum score), meibomian gland dropout (MGd) and Schirmer I test. Pressure of the upper eyelid was measured thrice with the novel pressure measurement device. Repeatability of the device was evaluated by intraclass correlation coefficient (ICC). Safety of the device was evaluated by observing ocular adverse reactions of each subject prior to measurement, at day 1 and day 7 following measurement. Correlations between eyelid pressure and ocular surface parameters of moderate-to-severe DED were analyzed by using Pearson correlation coefficient and Kendall's tau-b correlation coefficient. RESULTS: ICC of the measurement results in our study was 0.86. There was no abnormality presenting in all subjects recorded prior to measurement, 1 and 7 days following measurement. The eyelid pressure was significantly correlated with PBR (r = 0.286, P = 0.016), FBUT (r = -0.331, P = 0.005), CFS (r = 0.528, P = 0.000), lid margin abnormality (r = 0.408, P = 0.011) and MGd (r = 0.226, P = 0.016) in moderate-to-severe DED patients, but not significantly correlated with OSDI score (r = 0.016, P = 0.912), TMH (r = -0.002, P = 0.988), meibum score (r = -0.196, P = 0.317), LLT (r = 0.114, P = 0.346), PB (r = 0.116, P = 0.338), TB (r = 0.074, P = 0.544), meibum score (r = -0.196, P = 0.317) and Schirmer I test (r = 0.028, P = 0.821). CONCLUSION: The novel pressure measurement device exhibited good repeatability and safety in measuring eyelid pressure. Significant correlations were noted between the eyelid pressure and PBR, FBUT, CFS, lid margin abnormality and MGd in moderate-to-severe DED. The measurement of eyelid pressure combined with ocular surface parameters may be valuable for the assessment of DED.

H. pylori infection alters repair of DNA double-strand breaks via SNHG17.

Chronic infections can lead to carcinogenesis through inflammation-related mechanisms. Chronic infection of the human gastric mucosa with Helicobacter pylori is a well-known risk factor for gastric cancer. However, the mechanisms underlying H. pylori-induced gastric carcinogenesis are incompletely defined. We aimed to screen and clarify the functions of long noncoding RNAs (lncRNAs) that are differentially expressed in H. pylori-related gastric cancer. We found that lncRNA SNHG17 was upregulated by H. pylori infection and markedly increased the levels of double-strand breaks (DSBs). SNHG17 overexpression correlated with poor overall survival in patients with gastric cancer. The recruitment of NONO by overabundant nuclear SNHG17, along with the role of cytoplasmic SNHG17 as a decoy for miR-3909, which regulates Rad51 expression, shifted the DSB repair balance from homologous recombination toward nonhomologous end joining. Notably, during chronic H. pylori infection, SNHG17 knockdown inhibited chromosomal aberrations. Our findings suggest that spatially independent deregulation of the SNHG17/NONO and SNHG17/miR-3909/RING1/Rad51 pathways upon H. pylori infection promotes tumorigenesis in gastric cancer by altering the DNA repair system, which is critical for the maintenance of genomic stability. Upregulation of SNHG17 by H. pylori infection might be an undefined link between cancer and inflammation.

Liquid crystal filled dual-channel self-calibration optical-fiber surface plasmon resonance thermometer.

In this paper, we propose and demonstrate a dual-channel self-calibration multimode optical-fiber surface plasmon resonance thermometer. The structure of this thermometer is mainly composed by dual sensing channels, in which one channel is coated with a gold layer surrounded by liquid crystal (LC), and the other is prepared with bilayers of silver and thin indium tin oxide (ITO) layer. The gold channel is the main channel, and the channel of the ITO layer with high refractive index is viewed as a configuration of self-calibration. The experimental results of the system show that the temperature sensitivities are 1.006 nm/°C in the range of 20°C-34°C and 0.058 nm/°C in the range of 35°C-80°C. In particular, at the phase transition temperature 34.5°C of changing from the nematic to the isotropic phase of the LC, the temperature sensitivity shows a step increase of 6.8 nm with a unit temperature change. This structure can be highly advantageous for temperature controlling and alarming in laboratory monitoring and industrial production.

Death receptor 6 promotes ovarian cancer cell migration through KIF11.

The expression of death receptor 6 (DR6) is abnormal in some cancer types, but the function and underlying molecular mechanisms of DR6 in tumor progression are not yet clear. In the present study, our analysis of ovarian cancer RNA sequencing data from The Cancer Genome Atlas revealed that DR6 is upregulated in human ovarian cancer. We confirmed that the expression level of DR6 is upregulated in ovarian cancer tissues when compared with matched adjacent normal tissues. In addition, DR6 enhanced ovarian carcinoma cell migration ability, and decreased expression of DR6 inhibited the expression of matrix metalloprotease (MMP) 2 and MMP9, and increased the expression of E-cadherin. Additionally, DR6 shRNA caused a significant decrease in phosphoinositide-3-kinase (PI3K), phospho (p) -AKT, p-extracellular signal-regulated kinase (ERK), and p-mitogen-activated protein kinase kinase expression in SKOV3 cells. These results suggested that DR6 can enhance ovarian carcinoma cell migration ability through the mitogen-activated protein kinase/ERK and PI3K/AKT pathways. Notably, mass spectrometric analysis indicated that DR6 co-purified with kinesin family member 11 (KIF11), and we verified the interaction between KIF11 and DR6 by co-immunoprecipitation and glutathione S-transferase pull-down. Furthermore, we demonstrated that DR6 can bind tumor necrosis factor receptor-associated factor 4 (TRAF4) with co-immunoprecipitation. Overexpression of KIF11 or TRAF4 eliminated the suppression of carcinoma cell migration by DR6 knockdown. We also found that TRAF4 and KIF11 were upregulated in ovarian carcinomas and that their level of expression was positively correlated with that of DR6. The findings above suggest that DR6 may play a notable oncogenic role in ovarian malignancy by interacting with TRAF4 and KIF11, and that DR6 may be an effective therapeutic target in ovarian cancer.

Light-programmable manipulation of DC field in Laplacian Meta-devices.

Impressive progresses have been achieved in the field of metamaterial to mimic the illusion or camouflage effects in nature. These include invisible cloaks and many other cloak-based illusion meta-devices. However, to date many experiments only present single, static or discretized functionalities. The dynamical control of multiple kinds of illusion signals can only be achieved by embedding complex active sources directly connected to external stimuli, leading to limited on/off switching effect in a contact fashion. Here, we experimentally demonstrate a distinct scheme to incorporate multi-functions into one passive Laplacian DC meta-device, assisted by light illumination. It is shown that light-programmable cloaking, full illusion, and partial illusion can be achieved on the same device without physical contact of the heating pads or electric bias, at the cost of only four kinds of natural bulk materials with homogeneous parameters throughout. A DC network is fabricated to demonstrate the proof of concept, with measurement results in good agreement with the numerical simulations. The proposed scheme may open a new avenue to the non-contact multiphysical control of multi-illusion functions for Laplacian fields.

GALNT5 uaRNA promotes gastric cancer progression through its interaction with HSP90.

Recently, long noncoding RNAs (lncRNAs) have been reported to play a pivotal role in the occurrence and progression of cancer because of their unique characteristics and have therefore become an active area of cancer research. The object of this study was to screen lncRNAs that are dysregulated in gastric cancer and to investigate their potential functions. Global expression of lncRNAs in gastric cancer and adjacent normal tissues of patients was profiled using a microarray assay. We identified an lncRNA (GALNT5 uaRNA, UTR-associated RNA) that is derived from the 3'-UTR of GALNT5. This lncRNA was transcribed independently of the coding region of GALNT5 and was determined to be markedly upregulated in human gastric carcinoma relative to their corresponding normal gastric tissues by quantitative RT-PCR (qRT-PCR) analysis of tissues from 122 gastric carcinoma patients. The expression of GALNT5 uaRNA was significantly correlated with the TNM stage and with lymph node metastasis. Further results demonstrated that GALNT5 uaRNA facilitated the proliferation and migration of gastric cancer cells in vitro and promoted tumor growth in a mouse model of human gastric cancer. Our results also indicated that GALNT5 uaRNA might function in gastric cancer by binding with HSP90. Further studies indicated that the 5'-end stem-loop motifs of GALNT5 uaRNA promoted the binding of HSP90 and its client proteins, and thus inhibited ubiquitination of the clients. These results expanded our understanding of GALNT5 uaRNA as a new avenue for therapeutic intervention against gastric cancer progression.