Background Allergic conjunctivitis (AC) is an inflammation caused by a hypersensitive immune reaction of conjunctiva to external allergens. The microRNA (miRNA) miR-146a has been reported to suppress the exacerbation of inflammation. However, the underlying influence and mechanism of miR-146a in AC has not been completely elucidated. Methods We first successfully established an AC mouse model and AC cell model. After each model was treated based on the experimental purposes, miR-146a, FOXP3, and homeodomain-interacting protein kinases 3 (HIPK3) expressions were estimated by reverse transcription quantitative polymerase chain reaction (RT-qPCR). The levels of immunoglobulin E (IgE), tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), interleukin-4 (IL-4), and transforming growth factor-β (TGF-β) were assessed using enzyme-linked immunosorbent assay (ELISA) kits; the related proteins were analyzed by western blot, immunofluorescence, or immunohistochemistry (IHC) assays; the interaction between miR-146a and HIPK3 were validated by a dual-luciferase reporter gene assay; and the inflammatory infiltration was certified by hematoxylin and eosin (H&E) staining. Results Our results indicated that miR-146a and FOXP3 were downregulated in AC model mice. Meanwhile, miR-146a overexpression could upregulate FOXP3 and inhibit inflammatory response in TGF-β-induced thymocytes. Besides, our results testified that HIPK3, as a target gene of miR-146a, could reverse miR-146a-mediated FOXP3 upregulation and inflammation inhibition. Moreover, we discovered that miR-146a could downregulate p-STAT3 by targeting HIPK3, and activation of STAT3 also could reverse miR-146a-mediated inflammation suppression in TGF-β-induced thymocytes. More importantly, miR-146a could ameliorate inflammatory infiltration and downregulate HIPK3 and p-STAT3 in AC model mice. Conclusions We demonstrated a possible protective mechanism by the miR-146a/HIPK3/STAT3 axis, by which decrease of miR-146a could aggravate the inflammation of AC.

Diabetic retinopathy (DR) is a frequently occurring microvascular complication induced by long-term hyperglycemia. Pericyte-endothelial cell crosstalk is critical for maintaining vascular homeostasis and remodeling; however, the molecular mechanism underlying that crosstalk remains unknown. In this study, we explored the crosstalk that occurs between endothelial cells and pericytes in response to diabetic retinopathy. Pericytes were stimulated with cobalt chloride (CoCl2) to activate the HIF pathway. Hypoxia-stimulated pericytes were cocultured with high glucose- (HG-) induced endotheliocytes. Cell viability was determined using the CCK-8 assay. Western blot studies were performed to detect the expression of proteins associated with apoptosis, hypoxia, and inflammation. ELISA assays were conducted to analyze the release of IL-1β and IL-18. We performed a circRNA microarray analysis of exosomal RNAs expressed under normoxic or hypoxic conditions. A FISH assay was performed to identify the location of circEhmt1 in pericytes. Chromatin immunoprecipitation (CHIP) was used to identify the specific DNA-binding site on the NFIA-NLRP3 complex. We found that pericyte survival was negatively correlated with the angiogenesis activity of endotheliocytes. We also found that hypoxia upregulated circEhmt1 expression in pericytes, and circEhmt1 could be transferred from pericytes to endotheliocytes via exosomes. Moreover, circEhmt1 overexpression protected endotheliocytes against HG-induced injury in vitro. Mechanistically, circEhmt1 was highly expressed in the nucleus of pericytes and could upregulate the levels of NFIA (a transcription factor) to suppress NLRP3-mediated inflammasome formation. Our study revealed a critical role for circEhmt1-mediated NFIA/NLRP3 signaling in retinal microvascular dysfunction and suggests that signaling pathway as a target for treating DR.

BACKGROUNDTo understand the prevalence of diabetic retinopathy (DR) in Shenzhen and to analyze the risk factors for the occurrence and development of DR. Based on the comprehensive information system for diabetes prevention and control in the communities of Shenzhen in 2019, six community health service centers in Shenzhen were used as research sites to carry out multicenter, cross-sectional screening studies.METHODSCluster random sampling was used to collect data from 904 patients with diabetes in Shenzhen. The occurrence of DR and vision-threatening diabetic retinopathy (VTDR) was analyzed, and multivariate logistic regression was performed to analyze the risk factors for DR and VTDR. EpiData version 3.1 (EpiData Association, Odense, Denmark) statistical software was used to build a database, and Statistical Package for the Social Sciences (SPSS) version 25.0 (IBM Corp., Armonk, N.Y., USA) was used to sort up and analyze the data.RESULTSThe prevalence of DR among diabetic patients in Shenzhen was 18.58% [95% confidence interval (CI): 16.13-21.3%], and the prevalence of VTDR was 2.43% (95% CI: 1.57-1.2%). The prevalence of DR and VTDR was higher in males than in females. Logistic regression analysis showed that age, disease duration, medication mode, and the occurrence of diabetic peripheral neuropathy (DPN) were associated with the incidence of DR in diabetic patients, and that disease duration, the occurrence of DPN, and diabetic nephropathy were associated with the occurrence of VTDR.CONCLUSIONSThe prevalence of DR in the communities of Shenzhen is high. Age, disease duration, medications, and DPN are the major risk factors for the occurrence of DR.

Granular corneal dystrophy (GCD) is featured by corneal deposits of transforming growth factor beta-induced gene (TGFBI) mediated by the TGF-β (transforming growth factor-β)/Smad signaling. However, the roles of c-Jun amino-terminal kinase (JNK) pathway in GCD pathogenesis remains unexplored, which was investigated in this study. JNK signaling activation and inhibition in primary corneal fibroblasts were obtained by treatments with anisomycin and SP600125, respectively. Protein abundance and phosphorylation were detected by immunoblotting. Cell viability and apoptosis were analyzed by CCK-8 and flow cytometry respectively. TGFBI deposit and autophagy progression were assessed by immunofluorescence. The results found that JNK1 expression and phosphorylation were greatly increased in corneal tissues from GCD2 patients. JNK signaling activation impaired the viability and promoted apoptosis and autophagy processes in primary corneal fibroblasts, along with Smad2/3 phosphorylation, TGFBI accumulation and Bcl-2 suppression. Autophagy related proteins, such as ATG5 (autophagy related 5), ATG12 (autophagy related 12) and LC3B (microtubule-associated protein 1 light chain 3 beta), were also increased in anisomycin or TGF-β1 treated corneal fibroblasts. However, SP600125 effectively reversed the above effect induced by TGF-β1 treatment in corneal fibroblasts, including the TGF-β-induced autophagy progression. The results suggested that JNK signaling was activated in GCD2 corneal tissues, and it mediated the TGF-β-induced TGFBI protein accumulation and apoptosis of corneal fibroblasts during GCD2 pathogenesis.

Diabetic retinopathy (DR) is one of the most severe complications of diabetes mellitus, and retinal endoplasmic reticulum stress (ERS) plays an important role in the pathogenesis of DR. However, the exact mechanisms by which ERS mediates DR remain unclear. In this study, human retinal vascular endothelial cells (RVECs) were cultured in high-glucose (HG) medium to mimic the environment of DR. The expression of long non-coding RNA (lncRNA)-metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) was determined by quantitative real time PCR. ERS markers (glucose-regulated protein 78 [GRP78] and C/EBP homologous protein [CHOP]) were measured by immunofluorescence and western blotting. Cell viability was analyzed by the CCK-8 assay. The angiogenesis of RVECs was evaluated by tube formation assays. The levels of pro-inflammation cytokines TNF-α and IL-6 in RVECs were determined by ELISA assays. We found that exposure to HG levels upregulated MALAT1 and GRP78 expression in RVECs. While, GRP78 overexpression strengthened CHOP expression, cell proliferation suppression, capillary morphogenesis and inflammation in HG-treated RVECs. Importantly, knockdown of MALAT1 reversed HG-induced cell proliferation suppression, inhibited capillary morphogenesis, and inflammation in RVECs, and those effects were reversed by GRP78 overexpression. These results suggest that MALAT1 promotes HG-induced angiogenesis and inflammation in RVECs by upregulating ER stress, and might be target for treating DR.

Bromhexine was reported to relieve the symptoms of Sjogren Syndrome at an early stage. However, the underlying mechanism remains unclear. Here, we administered bromhexine at low doses in human primary conjunctival fornix epithelial cells, and found it stimulated MUC5AC secretion and lipid droplet production. Expression of the metabolism-related gene CHML was also upregulated by bromhexine treatment, and REP2, the protein produced by the CHML gene, was induced. These results suggest that bromhexine is a potential candidate eye drop drug for the treatment of multiple types of dry eye disease, not only limited to the treatment of dry eyes in Sjogren Syndrome.

This study evaluated whether lithium chloride (LiCl) prevents cytoplasmic accumulation of mutant-transforming growth factor β-induced protein (Mut-TGFBI) in granular corneal dystrophy (GCD) via activation of the autophagy pathway. Levels of TGFBI and microtubule-associated protein 1A/1B-light chain 3 (LC3) in 3 GCD patients and healthy controls were analyzed by immunohistochemistry (IHC) staining and Western blot. Primary corneal fibroblasts were isolated and transfected with wild type or mutant type TGFBI over-expressed vectors, and then treated with LiCl and/or autophagy inhibitor 3-methyladenine (3-MA). Then, levels of TGFBI, glycogen synthase kinase-3 (GSK-3) and LC3-I/-II were detected. Cell viability and transmission electron microscopy assay were also performed. Levels of TGFBI and LC3 were significantly increased in GCD patients. Over-expression of mutant type TGFBI inhibited cell viability and induced autophagy in corneal fibroblasts. LiCl downregulated the expression of TGFBI in mutant type TGFBI over-expressed cells in a dose- and time-dependent manner. LiCl enhanced autophagy in mutant type TGFBI over-expressed cells and recovered cell viability in those cells. However, the effects of LiCl were partly attenuated when autophagy was suppressed by 3-MA. To summarize, treatment with LiCl inhibited the expression of TGFBI and recovery the inhibitory of mutant type TGFBI in cell viability, at least part through enhancing of autophagy. These data strongly suggest that LiCl may be useful in the treatment of GCD.

Pathological retinal neovascularization (RNV) is a leading cause of vision loss in several ocular diseases; however, the underlying molecular mechanisms involved in the development of RNV remain unclear. It has been shown that microRNAs contribute to the process of angiogenesis, which has received greater attention by investigators who study the progression of RNV. In the present study, we investigated the function of miR-126 expression in retinal neural stem cells derived from induced pluripotent stem cell (IPSs) obtained from patients with RNV. During the induction process, the levels of both miR126 and vascular endothelial growth factor C (VEGF-C) gradually decreased, while the levels of spred-1 significantly increased. The existence of conserved miR-126-binding sites in spred-1 mRNA was predicted by computational algorithms, and verified by the luciferase reporter assay. The use of miR-126 mimics revealed dramatically reduced levels of spred-1, and increased levels of VEGF. When using shRNA to target spred-1, the resultant decreased levels of spred-1 were associated with significantly enhanced levels of VEGF expression. Our results demonstrate that miR-126 promotes VEGF expression in IPS cells by suppressing spred-1 expression, which contributes to angiogenesis during the progression of RNV. These findings suggest that miR-126 and spred-1 might serve as novel molecular targets for treating RNV-related ocular diseases.

Chemotherapy-induced peripheral neuropathic pain is a major limiting factor affecting cancer patients. No effective treatment is currently available. Cinobufacini, an aqueous extract from toad skin, is a widely used anti-cancer drug in China. Clinical evidence has demonstrated the safety and effectiveness of cinobufacini in combination with chemotherapy to promote the therapeutic efficacy while alleviating side effects, especially cancer-related pain symptoms. In this study, the effects of cinobufacini were investigated in a rat model of paclitaxel-induced peripheral neuropathic pain (PIPNP) to better understand and expand its clinical application. A single injection of cinobufacini (2.5 g/kg, i.p.) alleviated pre-established PIPNP, as indicated by decreased mechanical and thermal hypersensitivity compared with paclitaxel-treated rats. Repeated cinobufacini (1.25 and 2.5 g/kg, i.p.), given during the induction of PIPNP, prevented the establishment of paclitaxel-induced mechanical and thermal hypersensitivity. This preventative effect was associated with suppressed paclitaxel-induced TRPV1 up-regulation and spinal astrocyte activation, as well as decreased production of spinal TNF-α and IL-1β. These findings reveal cinobufacini as a therapeutic potential to treat and prevent paclitaxel-induced peripheral neuropathic pain.

Aim of the Study: Blepharoptosis is a drooping of the upper eyelid, usually due to dysfunction of the levator palpebrae superioris (LPS). Recently, skeletal muscle satellite cells (SSCs) have been reported to promote the repair of damaged skeletal muscle. This study aims to investigate the potential contribution of exogenous SSCs to the regeneration of mechanically damaged LPS. Materials and Methods: Thirty-two rats were randomly divided into four groups, including control group, SSCs-treated group, SSCs-treated injury group and non-treated injury group. After rats in injury groups were artificially lacerated on both the left and right LPS, HBBS (Hank's Balanced Salt Solution) containing SSCs was injected into upper eyelid tissue. After 7 days, the LPS muscle tissues were excised. In addition, skeletal muscle cells (SMCs) and SSCs were cocultured for use as an in vitro model, and the protective effects of SSCs on cultured SMCs were also investigated. Results: Histological staining revealed that exogenous SSCs repaired the damaged muscle fibers and attenuated the fibrosis of LPS, possibly due to the increased level of IGF-1. In contrast, the level of IL-1 beta, IL-6, TGF-beta 1 and Smad2/3 (phospho-T8) were significantly reduced in the SSCs-treated group. The in vitro model using coculture of skeletal muscle cells (SMCs) and SSCs also revealed an increased level of IGF-1 and reduced level of inflammatory factors, resulting in a better cell survival rate. Conclusions: This study found that exogenous SSCs can promote the repair of LPS mechanical damage and provides new insight into the development of novel therapeutic approaches for blepharoptosis.