Inhibition of microRNA‐129‐5p expression ameliorates ultraviolet ray‐induced corneal epithelial cell injury via upregulation of EGFR

Bone morphogenetic protein 4 inhibits corneal neovascularization by blocking NETs-induced disruption to corneal epithelial barrier

Corneal neovascularization (CoNV) is the second leading cause of visual impairment worldwide, and current drugs have certain limitations. Inflammatory response is the core pathological process of CoNV. Neutrophil extracellular traps (NETs) are generated after neutrophil activation, which promotes neovascularization. Prior studies demonstrated that bone morphogenetic protein 4 (BMP4) could significantly reduce inflammation and CoNV formation, its exact molecular mechanism remains unclear. Therefore, we stimulated human peripheral blood neutrophils with phorbol myristate acetate (PMA) or deoxyribonuclease I (DNase I) to induce or inhibit NETs formation. By using corneal sutures and subconjunctival injections of NETs or DNase I, rat CoNV models were established. Compared with the suture group, NETs formation and inflammatory cell infiltration in the corneal stroma were significantly increased, corneal edema was aggravated, and the length, area and diameter of CoNV were significantly enhanced in the NETs group. Furthermore, by curetting the corneal epithelial apical junctional complexes (AJCs), a crucial component in preserving the function of the corneal epithelial barrier, we discovered that the damage of AJCs had a significant role in inducing CoNV formation. NETs could induce CoNV formation by injuring corneal epithelial AJCs. Finally, by comparing the aforementioned indicators after the intervention of BMP4, BMP4 inhibitor Noggin and NADPH oxidase (NOX) inhibitor, we finally demonstrated that BMP4 could inhibit NETs-induced inflammation and corneal epithelial AJC injury, repair corneal epithelial barrier function and eventually inhibit CoNV formation by blocking NOX-2-dependent NETs formation.

Restoration of corneal epithelial barrier function: A possible target for corneal neovascularization

Corneal neovascularization (CoNV) is the second leading common cause of vision impairment worldwide and is a blinding pathological alteration brought on by ocular trauma, infection, and other factors. There are some limitations in the treatment of CoNV, hence it's critical to look into novel therapeutic targets. The corneal epithelial barrier, which is the initial barrier of the ocular surface, is an important structure that shields the eye from changes in the internal environment or invasion by the external environment. This study sought to collate evidence on the regulation of corneal epithelial barrier injury on the activation of vascular endothelial cells (VECs), basement membrane (BM) degradation, differentiation, migration, and proliferation of VECs, vascular maturation and stability, and other key processes in CoNV, so as to provide a novel concept for CoNV therapy targeting corneal epithelial barrier repair.

Role of non‑coding RNAs in UV‑induced radiation effects (Review)

Ultraviolet (UV) is divided into UVA (long-wave, 320-400 nm), UVB (middle-wave, 280-320 nm) and UVC (short-wave, 100-280 nm) based on wavelength. UV radiation (UVR) from sunlight (UVA + UVB) is a major cause of skin photodamage including skin inflammation, aging and pigmentation. Accidental exposure to UVC burns the skin and induces skin cancer. In addition to the skin, UV radiation can also impair visual function. Non-coding RNAs (ncRNAs) are a class of functional RNAs that do not have coding activity but can control cellular processes at the post-transcriptional level, including microRNA (miRNA), long non-coding RNA (lncRNA) and circulatory RNA (circRNA). Through a review of the literature, it was determined that UVR can affect the expression of various ncRNAs, and that this regulation may be wavelength specific. Functionally, ncRNAs participate in the regulation of photodamage through various pathways and play pathogenic or protective regulatory roles. In addition, ncRNAs that are upregulated or downregulated by UVR can serve as biomarkers for UV-induced diseases, aiding in diagnosis and prognosis assessment. Therapeutic strategies targeting ncRNAs, including the use of natural drugs and their extracts, have shown protective effects against UV-induced photodamage. In the present review, an extensive summarization of previous studies was performed and the role and mechanism of ncRNAs in UV-induced radiation effects was reviewed to aid in the diagnosis and treatment of UV-related diseases.

Bone morphogenetic protein 4 thermosensitive hydrogel inhibits corneal neovascularization by repairing corneal epithelial apical junctional complexes

Corneal neovascularization (CNV) is a heavy attribute of blinding disease changes. Existing medications need numerous infusions and have a limited absorption. Investigating novel drugs with safety, efficacy, and convenience is crucial. In this study, we developed a bone morphogenetic protein 4 (BMP4)-loaded poloxamer-oxidized sodium alginate (F127-OSA) thermosensitive hydrogel. The 14 % F127-OSA hydrogel transformed from sol to gel at 31-32 °C, which might extend the application period on the ocular surface. The hydrogel's porous structure and uniform dispersion made it possible for drugs to release gradually. We used a suture-induced rat CNV model to investigate the mechanism of CNV inhibition by hydrogel. We discovered that F127-OSA hydrogel loaded with BMP4 could significantly reduce the length and area of CNV, relieve corneal edema, and stop aberrant epithelial cell proliferation. The hydrogel's efficacy was superior to that of the common solvent group. Additionally, BMP4 thermosensitive hydrogel repaired ultrastructure, including microvilli, intercellular junctions, and damaged apical junctional complexes (AJCs), suggesting a potential mechanism by which the hydrogel prevented CNV formation. In conclusion, our investigation demonstrates that F127-OSA thermosensitive hydrogel loaded with BMP4 can repair corneal epithelial AJCs and is a promising novel medication for the treatment of CNV.

miR-129-5p/FGF2 Axis is Associated with Homocysteine-induced Human Umbilical Vein Endothelial Cell Injury

PURPOSE

Homocysteine (Hcy)-induced endothelial cell injury is a key event in atherosclerosis pathogenesis. In this study, we aimed to explore the mechanisms underlying Hcy-induced endothelial injury by assessing the effects of Hcy on endothelial cell proliferation and the microRNA (miR)-129-5p/fibroblast growth factor 2 (FGF2) axis.

METHODS

Human umbilical vein endothelial cells (HUVECs) were treated with Hcy to construct an endothelial cell injury model. Expression levels of FGF2 in Hcy-induced HUVECs were determined using quantitative real-time polymerase chain reaction and western blotting. An FGF2 overexpression lentiviral vector was constructed to upregulate FGF2 expression in HUVECs via lentivirus transduction. A cell counting kit-8 assay was used to explore the effects of FGF2 overexpression on HUVEC proliferation. An upstream regulatory miRNA was predicted, and its targetbinding relationship with FGF2 was evaluated using a dual-luciferase reporter assay.

RESULTS

We found that FGF2 expression in HUVECs was inhibited by Hcy treatment. Lentivirus transduction led to the overexpression of FGF2 in HUVECs, which significantly reversed the effect of Hcy on endothelial cell proliferation. miR-129-5p was experimentally validated as an upstream regulator of FGF2, and its decreased levels in HUVECs led to increased FGF2 expression. In addition, HUVEC proliferation was enhanced by the knockdown of miR-129-5p, and this effect was reversed by Hcy treatment.

CONCLUSION

Taken together, the results of this study revealed that Hcy inhibits FGF2 expression in HUVECs, and FGF2 is regulated by upstream miR-129-5p to improve the effect of Hcy on endothelial cell proliferation.

Limbal Epithelial Stem Cells in the Diabetic Cornea

Continuous replenishment of the corneal epithelium is pivotal for maintaining optical transparency and achieving optimal visual perception. This dynamic process is driven by limbal epithelial stem cells (LESCs) located at the junction between the cornea and conjunctiva, which is otherwise known as the limbus. In patients afflicted with diabetes, hyperglycemia-induced impairments in corneal epithelial regeneration results in persistent epithelial and other defects on the ocular surface, termed diabetic keratopathy (DK), which progressively diminish vision and quality of life. Reports of delayed corneal wound healing and the reduced expression of putative stem cell markers in diabetic relative to healthy eyes suggest that the pathogenesis of DK may be associated with the abnormal activity of LESCs. However, the precise role of these cells in diabetic corneal disease is poorly understood and yet to be comprehensively explored. Herein, we review existing literature highlighting aberrant LESC activity in diabetes, focusing on factors that influence their form and function, and emerging therapies to correct these defects. The consequences of malfunctioning or depleted LESC stocks in DK and limbal stem cell deficiency (LSCD) are also discussed. These insights could be exploited to identify novel targets for improving the management of ocular surface complications that manifest in patients with diabetes.

Sodium hyaluronate promotes proliferation, autophagy, and migration of corneal epithelial cells by downregulating miR-18a in the course of corneal epithelial injury

Corneal epithelium can resist the invasion of external pathogenic factors to protect the eye from external pathogens. Sodium hyaluronate (SH) has been confirmed to promote corneal epithelial wound healing. However, the mechanism by which SH protects against corneal epithelial injury (CEI) is not fully understood. CEI model mice were made by scratching the mouse corneal epithelium, and in vitro model of CEI were constructed via curettage of corneal epithelium or ultraviolet radiation. The pathologic structure and level of connective tissue growth factor (CTGF) expression were confirmed by Hematoxylin and Eosin staining and immunohistochemistry. CTGF expression was detected by an IHC assay. The levels of CTGF, TGF-β, COLA1A, FN, LC3B, Beclin1, and P62 expression were monitored by RT-qPCR, ELISA, Western blotting or immunofluorescence staining. Cell proliferation was detected by the CCK-8 assay and EdU staining. Our results showed that SH could markedly upregulate CTGF expression and downregulate miR-18a expression in the CEI model mice. Additionally, SH could attenuate corneal epithelial tissue injury, and enhance the cell proliferation and autophagy pathways in the CEI model mice. Meanwhile, overexpression of miR-18a reversed the effect of SHs on cell proliferation and autophagy in CEI model mice. Moreover, our data showed that SH could induce the proliferation, autophagy, and migration of CEI model cells by downregulating miR-18a. Down-regulation of miR-18a plays a significant role in the ability of SH to promote corneal epithelial wound healing. Our results provide a theoretical basis for targeting miR-18a to promote corneal wound healing.

The impact of sensory neuropathy and inflammation on epithelial wound healing in diabetic corneas

Diabetic peripheral neuropathy (DPN) is the most common complication of diabetes, with several underlying pathophysiological mechanisms, some of which are still uncertain. The cornea is an avascular tissue and sensitive to hyperglycemia, resulting in several diabetic corneal complications including delayed epithelial wound healing, recurrent erosions, neuropathy, loss of sensitivity, and tear film changes. The manifestation of DPN in the cornea is referred to as diabetic neurotrophic keratopathy (DNK). Recent studies have revealed that disturbed epithelial-neural-immune cell interactions are a major cause of DNK. The epithelium is supplied by a dense network of sensory nerve endings and dendritic cell processes, and it secretes growth/neurotrophic factors and cytokines to nourish these neighboring cells. In turn, sensory nerve endings release neuropeptides to suppress inflammation and promote epithelial wound healing, while resident immune cells provide neurotrophic and growth factors to support neuronal and epithelial cells, respectively. Diabetes greatly perturbs these interdependencies, resulting in suppressed epithelial proliferation, sensory neuropathy, and a decreased density of dendritic cells. Clinically, this results in a markedly delayed wound healing and impaired sensory nerve regeneration in response to insult and injury. Current treatments for DPN and DNK largely focus on managing the severe complications of the disease. Cell-based therapies hold promise for providing more effective treatment for diabetic keratopathy and corneal ulcers.

α-MSH ameliorates corneal surface dysfunction in scopolamine-induced dry eye rats and human corneal epithelial cells via enhancing EGFR expression

Dry eye (DE) is a chronic, multifactorial ocular surface disease associated with visual disturbance, tear film instability, hyperosmolarity, ocular surface inflammation and damage. Effective intervention is necessary to control this disease. In this study we topically applied α-melanocyte stimulating hormone (α-MSH) on the ocular surface of scopolamine-induced DE rats and found that it promoted tear secretion, reduced tear breakup time and fluorescein sodium staining and increased the number of conjunctival goblet cells. To investigate the mechanism, protein array was conducted, which showed that α-MSH exerted its effects via epithelial growth factor receptor (EGFR) in the JAK-STAT signaling pathway. Furthermore, in vitro experiments showed that α-MSH protected human corneal epithelial cells (hCECs) by maintaining their migration ability and viability and decreasing apoptosis. However, blockade of EGFR abolished these protective effects. Moreover, α-MSH decreased the level of autophagy in benzalkonium chloride (BAC)-stressed hCECs via EGFR. These results demonstrated that α-MSH ameliorated lesions and restored ocular surface functions by upregulating EGFR expression.

Long noncoding RNA MALAT1 sponges miR-129-5p to regulate the development of bronchopulmonary dysplasia by increasing the expression of HMGB1

OBJECTIVE

To explore the function and mechanism of long noncoding RNA (lncRNA) metastasis associated lung adenocarcinoma transcript 1 (MALAT1) in bronchopulmonary dysplasia.

METHODS

Alveolar epithelial cell line BEAS-2B was used as the cell model. The role of MALAT1 and microRNA miR-129-5p in regulating cellular viability and migration were examined by using the CCK-8 and Transwell assays, respectively, in vitro. The luciferase reporter assay and real-time (RT)-PCR were performed to confirm that miR-129-5p was a target of MALAT1. ELISA was conducted to validate MALAT1 and show that miR-129-5p regulated the gene encoding high-mobility group protein 1 (HMGB1).

RESULTS

Overexpression of MALAT1 significantly promoted cellular viability, whereas miR-129-5p had the opposite effect. miR-129-5p was shown to be a target of MALAT1, and HMGB1 could be upregulated by MALAT1 overexpression or miR-129-5p inhibition.

CONCLUSION

MALAT1 reduced the expression of miR-129-5p, promoting the viability of cells and blocking the development of bronchopulmonary dysplasia. In addition, MALAT1 increased the expression of HMGB1, which contributed to inflammation as the disease progressed.

Circ_0000345 Protects Endothelial Cells From Oxidized Low-Density Lipoprotein-Induced Injury by miR-129-5p/Ten-Eleven Translocation Axis

ABSTRACT

Circular RNAs have shown regulatory functions in atherosclerosis (AS) progression. Here, we explored the role and working mechanism of circ_0000345 in the AS cell model in vitro. Quantitative real-time polymerase chain reaction was applied to measure the enrichment of circ_0000345, microRNA-129-5p (miR-129-5p), and ten-eleven translocation-2 (TET2) messenger RNA. Cell Counting Kit 8 assay was used to analyze cell viability of human umbilical vein endothelial cells (HUVECs). Flow cytometry was conducted to assess cell apoptosis and cell cycle progression. The target relationship between miR-129-5p and circ_0000345 or TET2 was verified by the dual-luciferase reporter assay. The Western blot assay was used to analyze the protein level of TET2. Circ_0000345 abundance was reduced in serum samples of AS patients and AS cell model compared with their matching counterparts. Circ_0000345 overexpression promoted cell viability and cell cycle progression and hampered cell apoptosis in HUVECs induced by oxidized low-density lipoprotein. MiR-129-5p was a target of circ_0000345 and circ_0000345 attenuated ox-LDL-induced damage in HUVECs through sponging miR-129-5p. MiR-129-5p bound to the 3' untranslated region (3'UTR) of TET2, and miR-129-5p functioned in ox-LDL-induced HUVECs by targeting TET2. Circ_0000345 enhanced TET2 messenger RNA and protein expression through sponging miR-129-5p in HUVECs. Circ_0000345 attenuated ox-LDL-mediated injury in HUVECs through targeting miR-129-5p/TET2 axis. Increasing the levels of circ_0000345 and TET2 might be a novel insight into AS treatment.

How microRNAs affect the PD-L1 and its synthetic pathway in cancer

Programmed cell death-ligand 1 (PD-L1) is a glycoprotein that is expressed on the cell surface of both hematopoietic and nonhematopoietic cells. PD-L1 play a role in the immune tolerance and protect self-tissues from immune system attack. Dysfunction of this molecule has been highlighted in the pathogenesis of tumors, autoimmunity, and infectious disorders. MicroRNAs (miRNAs) are endogenous molecules that are classified as small non-coding RNA with approximately 20-22 nucleotides (nt) length. The function of miRNAs is based on complementary interactions with target mRNA via matching completely or incompletely. The result of this function is decay of the target mRNA or preventing mRNA translation. In the past decades, several miRNAs have been discovered which play an important role in the regulation of PD-L1 in various malignancies. In this review, we discuss the effect of miRNAs on PD-L1 expression and consider the effect of miRNAs on the synthetic pathway of PD-L1, especially during cancers.

MircoRNA-129-5p suppresses the development of glioma by targeting HOXC10

BACKGROUND

miR-129-5p has been reported to be abnormally expressed and plays an important role in the progression of various malignancies. However, its role in gliomas and its exact molecular mechanism need further research.

METHODS AND MATERIALS

RT-qPCR was performed to evaluate miR-129-5p and HOXC10 mRNA expression levels in tissues and cell lines. Cell proliferation was detected via Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU) and clone formation assays. Luciferase assays were used to validate the binding of seeds between miR-129-5p and HOXC10. A tumor xenograft model was developed to study the effect of miR-129-5p on glioma growth in vivo.

RESULTS

miR-129-5p was expressed at low levels in glioma tissues and cell lines. miR-129-5p overexpression inhibited glioma proliferation, migration and invasion. miR-129-5p negatively and directly targeted HOXC10. At the same time, HOXC10 was upregulated in glioma cancer, and HOXC10 knockdown inhibited cell proliferation, migration and invasion.

CONCLUSION

miR-129-5p inhibits glioma development by altering HOXC10 expression and may therefore serve as a new diagnostic marker and therapeutic target for glioma in the future.