Investigating the effect of lncRNA HOTAIR on apoptosis induced by myocardial ischemia-reperfusion injury

Spotlight on HOX cluster‑embedded antisense lncRNAs in cardiovascular diseases (Review)

Atherosclerosis is a complex and chronic inflammatory disease driven by multiple pathophysiological processes that are responsible for diverse cardiovascular events. Atherosclerotic cardiovascular disease, despite substantial triumphs in primary and secondary prevention, remains a dominant epidemic that impairs human health. Therefore, deciphering the pathogenesis of atherosclerosis will provide a real‑world translational understanding. Homeobox cluster‑embedded antisense long non‑coding RNAs (HOX‑lncRNAs), a nascent class of lncRNA molecules with versatile roles in cancer, can also orchestrate various cell functions in cardiovascular disorders and have thus captured the attention of many researchers. Subsequently, numerous studies have demonstrated the role of HOX‑lncRNAs as potential modulators of atherosclerosis. Nevertheless, given that the understanding of HOX‑lncRNAs in atherosclerosis is only just emerging, ongoing research must be initiated to thoroughly pinpoint such causal roles. The present review aimed to highlight the important contributions of HOX‑lncRNAs to atherosclerosis and other pivotal biological processes related to cardiovascular disease. The review concludes with a discussion of the limitations, outlook, challenges and possible solutions associated with HOX‑lncRNAs in atherosclerosis. Looking forward, this may lead to extraordinary breakthroughs in revealing the molecular underpinnings of HOX‑lncRNAs and may offer a promising yet challenging landscape for robust therapeutic strategies for atherosclerosis and/or associated cardiovascular disorders.

Ferrostatin-1 attenuates hypoxic-ischemic brain damage in neonatal rats by inhibiting ferroptosis

Background

Hypoxic-ischemic brain damage (HIBD) is a type of brain damage that is caused by perinatal asphyxia and serious damages the central nervous system. At present, there is no effective drug for the treatment of this disease. Besides, the pathogenesis of HIBD remains elusive. While studies have shown that ferroptosis plays an important role in HIBD, its role and mechanism in HIBD are yet to be fully understood.

Methods

The HIBD model of neonatal rats was established using the Rice-Vannucci method. A complete medium of PC12 cells was adjusted to a low-sugar medium, and the oxygen-glucose deprivation model was established after continuous hypoxia for 12 h. Laser Doppler blood flow imaging was used to detect the blood flow intensity after modeling. 2,3,5-triphenyl tetrazolium chloride staining was employed to detect ischemic cerebral infarction in rat brain tissue, and hematoxylin and eosin staining and transmission electron microscopy were used to observe brain injury and mitochondrial damage. Immunofluorescence was applied to monitor the expression of GFAP. Real-time quantitative polymerase chain reaction, western blot, and immunofluorescence were utilized to detect the expression of messenger RNA and protein. The level of reactive oxygen species (ROS) in cells was detected using the ROS detection kit.

Results

The results showed that ferrostatin-1 (Fer-1) significantly alleviated the brain injury caused by hypoxia and ischemia. Fer-1 significantly increased the expression of SLC3A2, SLC7A11, ACSL3, GSS, and GPX4 (P<0.05) and dramatically decreased the expressions of GFAP, ACSL4, TFRC, FHC, FLC, 4-HNE, HIF-1α, and ROS (P<0.05).

Conclusions

Fer-1 inhibits ferroptosis and alleviates HIBD by potentially targeting the GPX4/ACSL3/ACSL4 axis; however, its specific mechanism warrants further exploration.

Ginsenoside Rg3 improves microcystin-induced cardiotoxicity through the miR-128-3p/MDM4 axis

Microcystin (MC) is the byproduct of cyanobacteria metabolism that is associated with oxidative stress and heart damage. This study aimed to investigate the effect of ginsenoside Rg3 on MC-induced cardiotoxicity. A mouse model of myocardial infarction was constructed by oral MC administration. H9C2 cells were used for in vitro analysis. Cellular oxidative stress, apoptosis, and the relationship between miR-128-3p and double minute 4 protein (MDM4) were analyzed. MiR-128-3p expression was upregulated in vitro and in vivo after MC treatment, which was downregulated after Rg3 treatment. Left ventricular ejection fraction (LVEF) and left ventricular systolic pressure (LVSP) were increased and left ventricular end-diastolic pressure (LVEDP) was decreased after Rg3 treatment. Moreover, Rg3 alleviated MC-induced pathological changes and apoptosis in myocardial tissues. Meanwhile, Rg3 treatment decreased the lactate dehydrogenase (LDH) and malondialdehyde (MDA) levels and inhabited cell apoptosis and oxidative stress in MC-treated myocardial cells. MiR-128-3p overexpression attenuated the protective effect of Rg3 on MC-induced cardiotoxicity. MiR-128-3p negatively regulated MDM4 expression. This study revealed that Rg3 alleviated MC-induced cardiotoxicity through the miR-128-3p/MDM4 axis, which emphasized the potential of Rg3 as a therapeutic agent for MC-induced cardiotoxicity, and miR-128-3p as a target for the Rg3 therapy.

lncRNA HOTAIR promotes ROS generation and NLRP3 inflammasome activation by inhibiting Nrf2 in diabetic retinopathy

BACKGROUND

Diabetic retinopathy (DR) is a microvascular complication associated with damage to the retina due to inflammation induced by high glucose. Activation of the NLRP3 inflammasome plays a critical role in DR and its prevention is beneficial to patients. However, the regulation of long non-coding RNA (lncRNA) in NLRP3 inflammasome activation of DR is incompletely understood. So, this study aimed to uncover the functional and regulatory mechanism of the lncRNA HOTAIR in NLRP3 inflammasome activation in Dr.

METHODS

The vitreous humor was collected from the patients and detected the inflammatory and oxidative stress makers. Human retinal endothelial cells (HRECs) were cultured and stimulated in low D-glucose (5 mmol/L) or high D-glucose (20 mmol/L). Additionally, HRECs were knocked down HOTAIR with a si-RNA. Then, the NLRP3 inflammasome activation was analyzed by western blotting and pyroptosis cell imaging. The ROS was measured by specific probe. The activation of Nrf2 measured by Immunofluorescent staining. The interaction between HOTAIR and Nrf2 was evaluated by co-immunoprecipitation and RNA immunoprecipitation.

RESULTS

The expression of HOTAIR was significantly increased in the vitreous of patients with DR and in HRECs stimulated with high glucose. Furthermore, HOTAIR knockdown relieved NLRP3 inflammasome activation. More specifically, HOTAIR knockdown suppressed the expression of NLRP3, pro-caspase-1, and pro-IL-1β, as well as IL-1β maturation and pyroptosis. HOTAIR knockdown also interfered with the ROS generation induced by high glucose. Moreover, HOTAIR promoted the interaction between Nrf2 and Keap1 by binding and inactivating Nrf2.

CONCLUSION

The lncRNA HOTAIR promotes NLRP3 inflammasome activation and ROS generation by inhibiting Nrf2 in Dr.

Long non-coding RNAs and microRNAs as crucial regulators in cardio-oncology

Cancer is one of the leading causes of morbidity and mortality worldwide. Significant improvements in the modern era of anticancer therapeutic strategies have increased the survival rate of cancer patients. Unfortunately, cancer survivors have an increased risk of cardiovascular diseases, which is believed to result from anticancer therapies. The emergence of cardiovascular diseases among cancer survivors has served as the basis for establishing a novel field termed cardio-oncology. Cardio-oncology primarily focuses on investigating the underlying molecular mechanisms by which anticancer treatments lead to cardiovascular dysfunction and the development of novel cardioprotective strategies to counteract cardiotoxic effects of cancer therapies. Advances in genome biology have revealed that most of the genome is transcribed into non-coding RNAs (ncRNAs), which are recognized as being instrumental in cancer, cardiovascular health, and disease. Emerging studies have demonstrated that alterations of these ncRNAs have pathophysiological roles in multiple diseases in humans. As it relates to cardio-oncology, though, there is limited knowledge of the role of ncRNAs. In the present review, we summarize the up-to-date knowledge regarding the roles of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in cancer therapy-induced cardiotoxicities. Moreover, we also discuss prospective therapeutic strategies and the translational relevance of these ncRNAs.

lncRNA HOTAIR mediates OGD/R-induced cell injury and angiogenesis in a EZH2-dependent manner

Long non-coding RNAs (lncRNA) serve an important role in neonatal hypoxic-ischemic encephalopathy (HIE) have been reported to regulate the activity of HIE-associated proteins. The present study aimed to elucidate the role of Hox transcript antisense intergenic RNA (HOTAIR) in oxygen-glucose deprivation/reperfusion (OGD/R)-induced injury in human brain microvascular endothelial cells (hBMVECs). The levels of HOTAIR were evaluated in the serum of neonatal patients with HIE, and the effects of HOTAIR were evaluated using in vitro assays, such as reverse transcription-quantitative PCR to detect lncRNA and mRNA levels and western blot analysis to determine protein levels. Moreover, RNA immunoprecipitation assays were used to evaluate the association between HOTAIR and enhancer of zeste homolog 2 (EZH2), Cell Counting Kit-8 was used to detect cell viability, an endothelial monolayer cell permeability assay was used to analyze cell viability, TUNEL staining was used to detect the levels of apoptosis, a Transwell assay was used to evaluate cell invasion and a tube formation assay was used to analyze tube formation ability. In addition, the effects of HOTAIR and EZH2 on cell apoptosis and the invasive and tube formation abilities of hBMVECs were investigated using TUNEL, Transwell and tube formation assays, respectively. The results showed that the expression levels of HOTAIR were markedly increased both in neonatal HIE patients and in the OGD/R injury in vitro model. HOTAIR knockdown reduced hBMVEC viability, enhanced cell permeability and apoptosis, in addition to decreasing the expression levels of tight junction-related proteins, such as zonula occludens-1, occluden, Claudin5 and vascular endothelial-cadherin. However, EZH2 overexpression reversed the effects of HOTAIR silencing on hBMVECs. Additionally, HOTAIR knockdown enhanced the migratory and tube formation abilities of OGD/R-induced hBMVECs, which were also reversed by EZH2 overexpression. Overall, the present study revealed an association between the HOTAIR/EZH2 axis and brain microvascular endothelial cell injury and angiogenesis, which provides a novel insight into the molecular mechanism underlying stroke or the development of new pharmacotherapies.