MicroRNA-100 Mediates Hydrogen Peroxide-Induced Apoptosis of Human Retinal Pigment Epithelium ARPE-19 Cells

MiR-6837-3p protected retinal epithelial cells from oxidative stress by targeting E2F6

AIM

The mechanism of age-related macular degeneration (AMD) is a complex illness that is not fully understood. Therefore, the aim of this study was to investigate the expression patterns of miR-6837-3p in retinal epithelial cells.

METHODS

H2O2 was used to treat ARPE-19 cells for 2, 4 and 6 h to mimic the in vivo environment of AMD. MiR inhibitors and mimics were used to inhibit or overexpress miR-6837-3p in H2O2-treated ARPE-19 cells, respectively. Then, CCK8 assay, flow cytometry, and wound healing assays were conducted to assess the effects of miR-6837-3p on the behaviors of ARPE-19 cells, including cell growth, apoptosis, cycle progression, and migration. Finally, microRNA database prediction and luciferase reporter assays were used to demonstrate that miR-6837-3p targets the downstream gene E2F6.

RESULTS

H2O2 induced a decrease in cell viability and an increase in ROS levels in a time-dependent manner. Additionally, overexpression of miR-6837-3p increased cell viability and suppressed apoptosis in ARPE-19 cells treated with H2O2. Meanwhile, increased miR-6837-3p promoted cell cycle progression and cell migration of ARPE-19 cells. Finally, miR-6837-3p exerted anti-apoptosis and anti-oxidative stress effects by inhibiting the expression of E2F6 in ARPE-19 cells.

CONCLUSIONS

The MiR-6837-3p/E2F6 axis might be a target for the treatment of AMD to improve ARPE-19 cell function.

miR‑100: A key tumor suppressor regulatory factor in human malignant tumors (Review)

MicroRNA (miRNA/miR)‑100 is a crucial tumor‑suppressive miRNA that serves a pivotal role in the initiation and progression of various malignancies. miR‑100 regulates cancer cell proliferation, migration, invasion and apoptosis by targeting oncogenes, and acts as a molecular sponge to regulate long non‑coding RNAs and circular RNAs, thereby influencing processes such as glycolysis, autophagy and resistance to chemotherapy/radiotherapy. Furthermore, miR‑100 suppresses tumor progression by modulating key signaling pathways, including the PI3K/AKT and Wnt/β‑catenin signaling pathways. miR‑100 exhibits potential for early cancer diagnosis, particularly in cancer types such as gastric and lung cancer, where it can serve as a non‑invasive biomarker for early screening. As a therapeutic target, restoring miR‑100 expression can enhance the efficacy of chemotherapy or targeted therapy, thereby improving patient prognosis. Although challenges remain in its clinical application, including delivery systems and safety concerns, ongoing research suggests that miR‑100 holds promise for personalized treatment and early diagnosis. Given that cancer remains a global health challenge, research on miR‑100 provides hope for cancer therapy, particularly in China, where the mortality rates of malignancies such as gastric, lung and liver cancer continue to rise, further emphasizing its potential for clinical translation.

MiRNA-100 ameliorates diabetes mellitus-induced erectile dysfunction by modulating autophagy, anti-inflammatory, and antifibrotic effects

BACKGROUND

Diabetes mellitus-induced erectile dysfunction (DMED) has become a common disease in adult men that can seriously reduce the quality of life of patients, and new therapies are urgently needed. miRNA-100 has many targets and can induce autophagy and reduce fibrosis by inhibiting the mTOR pathway and the TGF-β pathway. However, no research has been conducted with miR-100 in the field of DMED, and the specific mechanism of action is still unclear.

OBJECTIVES

To ascertain the effects of miR-100 on corpus cavernosum tissue of DMED rats and vascular endothelial cells in a high glucose environment and to elucidate the relevant mechanisms in autophagy, fibrosis and inflammation to find a new approach for the DMED therapy.

METHODS

Thirty rats were divided into three groups: the control group, the DMED group, and the DMED + miR-100 group. Using intraperitoneal injections of streptozotocin, all rats except the control group were modeled with diabetes mellitus, which was verified using the apomorphine (APO) test. For rats in the DMED + miR-100 group, rno-miR-100-5p agomir (50 nmol/kg, every 2 days, 6 times in total) was injected via the tail vein. After 13 weeks, the erectile function of each rat was assessed using cavernous manometry, and the corpus cavernosum tissue was harvested for subsequent experiments. For cellular experiments, human coronary microartery endothelial cells (HCMEC) were divided into four groups: the control group, the high-glucose (HG, 40 mM) group, the HG + mimic group, and the HG + inhibitor group. The cells were cultured for 6 days and collected for subsequent experiments 2 days after transfection.

RESULTS

Diabetic modeling impaired the erectile function in rats, and miR-100 reversed this effect. By measuring autophagy-related proteins such as mTOR/Raptor/Beclin1/p62/LC3B, we found that miR-100 could suppress the expression of mTOR and induce autophagy. The analysis of the eNOS/NO/cGMP axis function indicated that impaired endothelial function was improved by miR-100. By evaluating the TGF-β1/CTGF/Smad2/3 and NF-κB/TNF-α pathways, we found that miR-100 could lower the level of inflammation and fibrosis, which contributed to the improvement of the erectile function. Cellular experiments can be used as supporting evidence for these findings.

CONCLUSION

MiR-100 can improve the erectile function by inhibiting mTOR and thus inducing autophagy, improving the endothelial function through the eNOS/NO/cGMP axis, and exerting antifibrotic and anti-inflammatory effects, which may provide new ideas and directions for the treatment of DMED.

Oxidative stress in the eye and its role in the pathophysiology of ocular diseases

Oxidative stress occurs through an imbalance between the generation of reactive oxygen species (ROS) and the antioxidant defense mechanisms of cells. The eye is particularly exposed to oxidative stress because of its permanent exposure to light and due to several structures having high metabolic activities. The anterior part of the eye is highly exposed to ultraviolet (UV) radiation and possesses a complex antioxidant defense system to protect the retina from UV radiation. The posterior part of the eye exhibits high metabolic rates and oxygen consumption leading subsequently to a high production rate of ROS. Furthermore, inflammation, aging, genetic factors, and environmental pollution, are all elements promoting ROS generation and impairing antioxidant defense mechanisms and thereby representing risk factors leading to oxidative stress. An abnormal redox status was shown to be involved in the pathophysiology of various ocular diseases in the anterior and posterior segment of the eye. In this review, we aim to summarize the mechanisms of oxidative stress in ocular diseases to provide an updated understanding on the pathogenesis of common diseases affecting the ocular surface, the lens, the retina, and the optic nerve. Moreover, we discuss potential therapeutic approaches aimed at reducing oxidative stress in this context.

Immunomodulatory and Antioxidant Drugs in Glaucoma Treatment

Glaucoma, a group of diseases characterized by progressive retinal ganglion cell loss, cupping of the optic disc, and a typical pattern of visual field defects, is a leading cause of severe visual impairment and blindness worldwide. Elevated intraocular pressure (IOP) is the leading risk factor for glaucoma development. However, glaucoma can also develop at normal pressure levels. An increased susceptibility of retinal ganglion cells to IOP, systemic vascular dysregulation, endothelial dysfunction, and autoimmune imbalances have been suggested as playing a role in the pathophysiology of normal-tension glaucoma. Since inflammation and oxidative stress play a role in all forms of glaucoma, the goal of this review article is to present an overview of the inflammatory and pro-oxidant mechanisms in the pathophysiology of glaucoma and to discuss immunomodulatory and antioxidant treatment approaches.

Oxidative Stress: A Suitable Therapeutic Target for Optic Nerve Diseases?

Optic nerve disorders encompass a wide spectrum of conditions characterized by the loss of retinal ganglion cells (RGCs) and subsequent degeneration of the optic nerve. The etiology of these disorders can vary significantly, but emerging research highlights the crucial role of oxidative stress, an imbalance in the redox status characterized by an excess of reactive oxygen species (ROS), in driving cell death through apoptosis, autophagy, and inflammation. This review provides an overview of ROS-related processes underlying four extensively studied optic nerve diseases: glaucoma, Leber's hereditary optic neuropathy (LHON), anterior ischemic optic neuropathy (AION), and optic neuritis (ON). Furthermore, we present preclinical findings on antioxidants, with the objective of evaluating the potential therapeutic benefits of targeting oxidative stress in the treatment of optic neuropathies.