Knockdown of lncRNA TUG1 alleviates diabetic retinal vascular dysfunction through regulating miR-524-5p/FGFR2

Roles of noncoding RNAs in diabetic retinopathy: Mechanisms and therapeutic implications

Diabetic retinopathy (DR) is a microvascular complication of diabetes that leads to vision loss. The striking features of DR are hard exudate, cotton-wool spots, hemorrhage, and neovascularization. The dysregulated retinal cells, encompassing microvascular endothelial cells, pericytes, Müller cells, and adjacent retinal pigment epithelial cells, are involved in the pathological processes of DR. According to recent research, oxidative stress, inflammation, ferroptosis, pyroptosis, apoptosis, and angiogenesis contribute to DR. Recent advancements have highlighted that noncoding RNAs could regulate diverse targets in pathological processes that contribute to DR. Noncoding RNAs, including long noncoding RNAs, microRNAs (miRNA), and circular RNAs, are dysregulated in DR, and interact with miRNA, mRNA, or proteins to control the pathological processes of DR. Hence, modulation of noncoding RNAs may have therapeutic effects on DR. Small extracellular vesicles may be valuable tools for transferring noncoding RNAs and regulating the genes involved in progression of DR. However, the roles of noncoding RNA in developing DR are not fully understood; it is critical to summarize the mechanisms for noncoding RNA regulation of pathological processes and pathways related to DR. This review provides a fundamental understanding of the relationship between noncoding RNAs and DR, exploring the mechanism of how noncoding RNA modulates different signaling pathways, and pave the way for finding potential therapeutic strategies for DR.

Diabetes and diabetic associative diseases: An overview of epigenetic regulations of TUG1

The epigenetic regulation of lncRNA TUG1 has garnered significant attention in the context of diabetes and its associated disorders. TUG1's multifaceted roles in gene expression modulation, and cellular differentiation, and it plays a major role in the growth of diabetes and the issues that are related to it due to pathological processes. In diabetes, aberrant epigenetic modifications can lead to dysregulation of TUG1 expression, contributing to disrupted insulin signaling, impaired glucose metabolism, and beta-cell dysfunction. Moreover, it has been reported that TUG1 contributes to the development of problems linked to diabetes, such as nephropathy, retinopathy, and cardiovascular complications, through epigenetically mediated mechanisms. Understanding the epigenetic regulations of TUG1 offers novel insights into the primary molecular mechanisms of diabetes and provides a possible path for healing interventions. Targeting epigenetic modifications associated with TUG1 holds promise for restoring proper gene expression patterns, ameliorating insulin sensitivity, and mitigating the inception and development of diabetic associative diseases. This review highlights the intricate epigenetic landscape that governs TUG1 expression in diabetes, encompassing DNA methylation and alterations in histone structure, as well as microRNA interactions.

A Mini-review on New Developments in Nanocarriers and Polymers for Ophthalmic Drug Delivery Strategies

The eye is an important and vital organ of the human body consisting of two segments - anterior and posterior segments and these segments are associated with many diseases. This review elaborates upon the various eye-related diseases with their medications and carriers used to deliver them. Delivery strategies include drugs encapsulated into liposomes, polymeric micelles of drugs, solid lipid nanoparticles, nanostructured lipid carriers, nano emulsions, and Nanosuspension used to improve penetrating properties, bioavailability, and residence time of the drugs as examples available in the literature. With regard to this, different forms of ocular drug delivery are classified and elaborated. Additionally, the possibility of addressing the physical and chemical complexities of ocular diseases and how they could be overcome with environmentally stable nanoformulations are briefly discussed. Enhanced drug delivery efficiency with various novel pharmaceuticals along with enhanced uptake by different routes/modes of drug administration. Current advancements in drug carrier systems, i.e., nanocarriers, have shown promise for improving the retention time, drug permeation and prolonging the duration of release of the drug in the ocular site. Bio-degradable polymers investigated for the preparation of nanocarriers for the entrapment of drugs and to enhance the efficacy through improved adherence of tissue in the eye, sustained release measures, enhanced bioavailability, lower toxicity, and targeted delivery is applicable. This review covers the introduction of various nanocarriers and polymers for ocular drug delivery with the purpose of enhancing the absorption, retention and bioavailability of medications in the eye.

FGFR2 modulates the Akt/Nrf2/ARE signaling pathway to improve angiotensin II-induced hypertension-related endothelial dysfunction

BACKGROUND

Fibroblast growth factor receptor (FGFR)2 expression was decreased in hypertension patients while its role in hypertension was not explored. This experiment aimed to investigate the expression ofFGFR2 in angiotensin II (Ang II)-induced human umbilical vein endothelial cells (HUVECs) and the role of FGFR2 in improving AngII-induced hypertension-related endothelial dysfunction.

METHODS

AngII-induced HUVECs simulated the hypertension model in vitro. The expression of FGFR2 in Ang II-induced HUVECs and transfected HUVECswas detected by RT-qPCR and western blot. The viability, apoptosis, migration and tube formation ability of Ang II-induced HUVECs were analyzed by Methyl Thiazolyl Tetrazolium (MTT) assay, flow cytometry analysis, wound healing assay and tube formation assay.Detectionof lactate dehydrogenase (LDH), caspase 3, Nitric Oxide (NO) and oxidative stress levels was conducted by assay kits and reactive oxygen species (ROS) level was detected by DCFH-DA assay. The expression of apoptosis-related proteins, protein kinase B(Akt)/nuclear factor E2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway-related proteins, phospho(p)-endothelial nitric oxide synthase (eNOS) and eNOS was determined by western blot.

RESULTS

The expression of FGFR2 was decreased in Ang II-induced HUVECs. FGFR2overexpression increased viability, suppressed apoptosis and oxidative stress, and improve endothelial dysfunction of AngII-induced HUVECs through activating the Akt/Nrf2/ARE signaling pathway. MK-2206 (Akt inhibitor) could weaken the effect of FGFR2overexpression to reduce viability, promote apoptosis and oxidative stress, and aggravate endothelial dysfunction of Ang II-inducedHUVECs.

CONCLUSION

Inconclusion, FGFR2activated the Akt/Nrf2/ARE signaling pathway to improve AngII-induced hypertension-related endothelial dysfunction.

Roles of long non-coding RNAs in angiogenesis-related diseases: Focusing on non-neoplastic aspects

Angiogenesis is a key process in organ and tissue morphogenesis, as well as growth during human development, and is coordinated by pro- and anti-angiogenic factors. When this balance is affected, the related physiological and pathological changes lead to disease. Long non-coding RNAs (lncRNAs) are an important class of non-coding RNAs that do not encode proteins, but play a dynamic role in regulating gene expression. LncRNAs have been reported to be extensively involved in angiogenesis, particularly tumor angiogenesis. The non-tumor aspects have received relatively little attention and summary, but there is a broad space for research and exploration on lncRNA-targeted angiogenesis in this area. In this review, we focus on lncRNAs in angiogenesis-related diseases other than tumors, such as atherosclerosis, myocardial infarction, stroke, diabetic complications, hypertension, osteoporosis, dermatosis, as well as, endocrine, neurological, and other systemic disorders. Moreover, multiple cell types have been implicated in lncRNA-targeted angiogenesis, but only endothelial cells have attracted widespread attention. Thus, we explore the roles of other cells. Finally, we summarize the potential research directions in the area of lncRNAs and angiogenesis that can be undertaken by combining cutting-edge technology and interdisciplinary research, which will provide new insights into the involvement of lncRNAs in angiogenesis-related diseases.

Sprouty-related proteins with EVH1 domain (SPRED2) prevents high-glucose induced endothelial-mesenchymal transition and endothelial injury by suppressing MAPK activation

Diabetic retinopathy (DR) is a common complication of diabetes, and the leading cause of blindness in adults. Sprouty-related proteins with EVH1 domain (SPRED2) play an important role in diabetes and are closely related to the lens and eye morphogenesis. This study attempted to investigate the role and related mechanism of SPRED2 in DR. DR rat model was established by administration streptozocin. Human retinal endothelial cells (HRECs) were treated with high glucose (HG) to mimic DR. The results showed that SPRED2 expression was decreased in the retinal tissues of DR rats and HG-treated HRECs. MTT assay and flow cytometry data showed that SPRED2 overexpression reduced cell viability of HG-treated HRECs. SPRED2 overexpression enhanced Caspase-3 activity and promoted apoptosis of HG-treated HRECs. Furthermore, the expressions of endothelial cell markers CD31 and E-cad were down-regulated, whereas the expressions of mesenchymal cell markers FSP1, SM22, and α-SMA were up-regulated in the HG-treated HRECs. SPRED2 overexpression reversed HG-induced endothelial–mesenchymal transition in HRECs. The expressions of tight junction components claudin 3, occludin, and ZO-1 were increased in HG-treated HRECs following SPRED2 up-regulation. In addition, SPRED2 overexpression downregulated the expression of p-ERK1/2, p-p38, and p-JNK in the HG-treated HRECs. In conclusion, this study demonstrated that SPRED2 overexpression repressed endothelial–mesenchymal transition and endothelial injury in HG-treated HRECs by suppressing MAPK signaling pathway. These findings suggested that SPRED2 may be a novel potential therapeutic target implicated in DR progression.