Amphiregulin (AREG) stimulates human epithelial ovarian cancer (EOC) cell invasion by downregulating E-cadherin expression. YAP is a transcriptional cofactor that has been shown to regulate tumorigenesis. This study aimed to examine whether AREG activates YAP in EOC cells and explore the roles of YAP in AREG-induced downregulation of E-cadherin and cell invasion. Analysis of the Cancer Genome Atlas (TCGA) showed that upregulation of AREG and EGFR were associated with poor survival in human EOC. Treatment of SKOV3 human EOC cells with AREG induced the activation of YAP. In addition, AREG downregulated E-cadherin, upregulated Egr-1 and Slug, and stimulated cell invasion. Using gain- and loss-of-function approaches, we showed that YAP was required for the AREG-upregulated Egr-1 and Slug expression. Furthermore, YAP was also involved in AREG-induced downregulation of E-cadherin and cell invasion. This study provides evidence that AREG stimulates human EOC cell invasion by downregulating E-cadherin expression through the YAP/Egr-1/Slug signaling.

The role of programmed death ligand 1 (PD-L1) has been extensively investigated in adaptive immune system. However, increasing data show that innate immune responses are also affected by the immune checkpoint molecule. It has been demonstrated that regulation of PD-L1 signaling in macrophages may be a potential therapeutic method for acute respiratory distress syndrome (ARDS). However, the PD-L1 expression pattern in local macrophages and whole lung tissues remains mysterious, hindering optimization of the potential treatment program. Therefore, we aim to determine the PD-L1 expression pattern during ARDS. Our findings show that PD-L1 levels are markedly increased in lipopolysaccharide (LPS)-stimulated lung tissues, which might be attributable to an increase in the gene expression by immune cells, including macrophages and neutrophils. In vitro experiments are performed to explore the mechanism involved in LPS-induced PD-L1 production. We find that PD-L1 generation is controlled by transcription factors early growth response 1 (Egr-1) and CCAAT/enhancer binding protein delta (C/EBPδ). Strikingly, PD-L1 production is enhanced by phosphoinositide-3 kinase (PI3K)-protein kinase B (AKT) signaling pathway via up-regulation of Egr-1 and C/EBPδ expressions. Additionally, we observe that expressions of Egr-1 and C/EBPδ mutually reinforce each other. Moreover, we observe that PD-L1 is protective for ARDS due to its regulatory role in macrophage-associated inflammatory response. In summary, during LPS-induced ARDS, PD-L1 expression, which is beneficial for the disease, is increased via the PI3K-AKT1-Egr-1/C/EBPδ signaling pathway, providing theoretical basis for application of methods controlling PD-L1 signaling in macrophages for ARDS treatment in clinic.

Asthma is a chronic inflammatory disease with a high morbidity rate in children and significantly impacts their healthy growth. It is reported that Th2 cell-mediated airway inflammation and activated oxidative stress are involved in the pathogenesis of asthma. S14G-humanin (HNG) is a derivative of Humanin with higher activity. The present study proposes to explore the potential treating property of HNG on asthma. An asthma model was constructed in mice using ovalbumin (OVA), the mice were treated with 2.5 mg/kg and 5 mg/kg HNG for 16 days. Dramatically increased lung weight index, elevated number of monocytes, eosinophils, and neutrophils, promoted production of Th2 cytokines including interleukin-4 (IL-4), interleukin-5 (IL-5), and interleukin-13 (IL-13), and severe histological pathology were observed in OVA-challenged mice, all of which were extremely alleviated by 2.5 mg/kg and 5 mg/kg HNG. Furthermore, the increased malondialdehyde (MDA) level and declined superoxide dismutase (SOD) activity in OVA-challenged mice were abolished by 2.5 mg/kg and 5 mg/kg HNG. Lastly, the upregulated TLR4, p-NF-κB p65, and early growth response 1 (Egr-1) in lung tissues of OVA-challenged mice were pronouncedly downregulated by 2.5 mg/kg and 5 mg/kg HNG. Collectively, our data suggested that HNG ameliorated airway inflammation in asthma partially due to NF-κB and Egr-1-mediated responses.

Post-stroke depression (PSD) negatively affects the prognosis of post-stroke animals. Ramelteon has neuroprotection for chronic ischemia animals, but the effect and the biological mechanism of it on PSD is still unclear. This study explored the effects of ramelteon with prophylactic administration on blood-brain barrier in rats with middle cerebral artery occlusion (MCAO) and the oxygen-glucose deprivation/reperfusion (OGD/R) bEnd.3 cells and found that ramelteon pretreatment improved the depressive-like behaviors and decreased infarct area in MCAO rats. Also, this study found ramelteon pretreatment improved viability and inhibited permeability in OGD/R cells. In addition, this study found that MCP-1, TNF-α, and IL-1 levels were raised in the MCAO rats and that occludin protein and mRNA levels were decreased in the MCAO and the OGD/R models, while the Egr-1 level was up-regulated. All of these were antagonized by ramelteon pretreatment. In addition, overexpression of Egr-1 could reverse the effect of 100 nM ramelteon pretreatment on FITC and occludin levels in OGD/R cells. In short, this study has demonstrated that the protective effect on PSD of ramelteon pretreatment on MCAO rats is related to the development of BBB permeability and that ramelteon regulates occludin to protect the BBB by inhibiting Egr-1.

Previous studies have shown that 3-day d-amphetamine (AMPH) treatment effectively induced conditioned place preferences (CPP) and impaired pair bonding behaviors in prairie voles (Microtus ochrogaster). Using this established animal model and treatment regimen, we examined the effects of the demonstrated threshold rewarding dose of AMPH on various behaviors and their potential underlying neurochemical systems in the brain of female prairie voles. Our data show that 3-day AMPH injections (0.2 mg/kg/day) impaired social recognition and decreased depressive-like behavior in females without affecting their locomotion and anxiety-like behaviors. AMPH treatment also decreased neuronal activation indicated by the labeling of the early growth response protein 1 (Egr-1) as well as the number of neurons double-labeled for Egr-1 and corticotrophin-releasing hormone (CRH) in the dentate gyrus (DG) of the hippocampus and paraventricular nucleus of the hypothalamus (PVN) in the brain. Further, AMPH treatment decreased the number of neurons double-labeled for Egr-1 and tyrosine hydroxylase (TH) but did not affect oxytocinergic neurons in the PVN or cell proliferation and neurogenesis markers in the DG. These data not only demonstrate potential roles of the brain CRH and dopamine systems in mediating disrupted social recognition and depressive-like behaviors by AMPH in female prairie voles, but also further confirm the utility of the prairie vole model for studying interactions between psychostimulants and social behaviors.

Exosomes (Exos) extracted from human adipose mesenchymal stromal/stem cells (hAD-MSCs) have been reported as therapeutic tools for tissue repair, but how they regulate angiogenesis of endothelial cells remains unknown. In this study, hAD-MSCs were isolated, and early growth response factor-1, Smooth muscle and endothelial cell enriched migration/differentiation-associated long-noncoding RNA (lncRNA-SENCR), and vascular endothelial growth factor-A (VEGF-A) overexpression or knockdown was achieved. Exos extracted from hAD-MSCs (hADSC-Exos) were co-cultured with human umbilical vein endothelial cells (HUVECs) to detect the effects of EGR-1, lncRNA-SENCR, and VEGF-A on angiogenesis and the relationships between EGR-1, lncRNA-SENCR, Dyskerin pseudouridine synthase 1 (DKC1), and VEGF-A. An in vivo experiment verified the effect of hADSC-Exos on the wound healing process. hADSC-Exos substantially promoted the proliferation, migration, and angiogenesis of HUVECs, which could be reversed by short-hairpin RNA SENCR (shSENCR) transfection. hADSC-Exos had elevated expression of EGR-1, which bound to the lncRNA-SENCR promoter. The suppressive effect of Exo-shEGR1 on HUVECs was counteracted by SENCR overexpression. LncRNA-SENCR was shown to interact with DKC1. Overexpression of DKC1 or lncRNA-SENCR maintained stable VEGF-A expression. Overexpression of VEGF-A reversed the suppressive effect of shSENCR on HUVECs. Consistent results were obtained in mice in vivo. Overall, hADSC-Exo EGR-1 upregulates lncRNA-SENCR expression to activate the DKC1/VEGF-A axis, facilitating the wound-healing process by increasing angiogenesis.

Cabozantinib is a tyrosine kinase inhibitor with anti-tumor activity in kidney cancer. However, the efficacy of cabozantinib in other renal diseases has never been reported. Here, we focused on exploring the effect of cabozantinib on diabetic nephropathy (DN). The biofunctions of cabozantinib in human renal glomerular endothelial cells (hGECs) under high glucose conditions have been investigated. We found that cabozantinib ameliorated high glucose-induced oxidative stress in hGECs with decreased production of mitochondrial reactive oxygen species (ROS) and increased glutathione peroxidase (GSH-PX) activity. Cabozantinib ameliorated high glucose-induced reduction in the expression of endothelial nitric oxide synthase (eNOS) and the production of nitric oxide (NO) in hGECs. It also suppressed the expression of pro-inflammatory mediators, interleukin-6 (IL-6) and monocyte chemokine protein 1 (MCP-1), against high glucose exposure in hGECs. Cabozantinib reduced the expression of early growth response-1 (Egr-1) in high glucose-treated hGECs, while Egr-1 overexpression abolished the protective effects of cabozantinib against high glucose in hGECs. In conclusion, cabozantinib protected hGECs from high glucose-induced oxidative stress, NO deficiency, and inflammation via regulating Egr-1. These findings suggest that cabozantinib might be used as an adjuvant to control DN.

Myocardial apoptosis induced by myocardial ischemia and hyperlipemia are the main causes of high mortality of cardiovascular diseases. It is not clear whether there is a common mechanism responsible for these two kinds of cardiomyocyte apoptosis. Previous studies demonstrated that early growth response protein 1 (EGR-1) has a pro-apoptotic effect on cardiomyocytes under various stress conditions. Here, we found that EGR-1 is also involved in cardiomyocyte apoptosis induced by both ischemia and high-fat, but how EGR-1 enters the nucleus and whether nuclear EGR-1 (nEGR-1) has a universal effect on cardiomyocyte apoptosis are still unknown. By analyzing the phosphorylation sites and nucleation information of EGR-1, we constructed different mutant plasmids to confirm that the nucleus location of EGR-1 requires Ser501 phosphorylation and regulated by JNK. Furthermore, the pro-apoptotic effect of nEGR-1 was further explored through genetic methods. The results showed that EGR-1 positively regulates the mRNA levels of apoptosis-related proteins (ATF2, CTCF, HAND2, ELK1), which may be the downstream targets of EGR-1 to promote the cardiomyocyte apoptosis. Our research announced the universal pro-apoptotic function of nEGR-1 and explored the mechanism of its nucleus location in cardiomyocytes, providing a new target for the \"homotherapy for heteropathy\" to cardiovascular diseases.

Homocysteine (Hcy) is a non-essential amino acid produced from methionine. It has been reported that high concentrations of Hcy are related to the pathogenesis of neurodegenerative diseases and induce the disruption of the blood-brain barrier (BBB) by triggering oxidative stress and inflammation. LCZ696 is a novel antihypertensive agent that has been recently reported to possess promising anti-inflammatory properties. However, whether it has a protective effect on the BBB disruption is still unknown. For the first time, in this study, we aim to investigate whether LCZ696 exerts anti-inflammatory effects on Hcy-induced injury in brain endothelial cells and explore its neuroprotective properties. In in vivo experiments, we found that treatment with LCZ696 ameliorated oxidative stress by reducing malondialdehyde (MDA) and increasing glutathione (GSH). Furthermore, LCZ696 downregulated the excessive release of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) at mRNA and protein levels. Importantly, it reversed the disruption of the BBB induced by Hcy stimulation. In the in vitro human brain microvascular endothelial cell (HBMVEC) experiments, compared to the control, the permeability of the endothelial monolayer was significantly enlarged, the expression level of occludin declined, and Egr-1 upregulated by the introduction of Hcy, and these were all reversed by the treatment with LCZ696. Lastly, we found that the protective effects of LCZ696 against Hcy-induced reduction of occludin and hyper-permeability of the endothelial monolayer were greatly abolished by the overexpression of Egr-1. Taken together, we found that LCZ696 protected against Hcy-induced impairment of BBB integrity by increasing the expression of occludin, all mediated by the inhibition of Egr-1.

Acute myocardial infarction (AMI) is a type of cardiovascular diseases that severely threatens human being, but the mechanisms have not been thoroughly clarified. Here, we detected that microRNA-15a-5p (miR-15a-5p) was up-regulated in AMI. Knockdown of miR-15a-5p reduced cell mortality in hypoxic-treated myocardial cells. In addition, we determined that glutathione peroxidase4 (GPX4) was the direct target of miR-15a-5p by luciferase reporter assay. Over-expression of miR-15a-5p strengthened ferroptosis, then aggravated myocardial cell hypoxia injury. Mechanistically, silencing transcription factor early growth response-1 (Egr-1) inhibited the level of miR-15a-5p, increased the protein expression of GPX4, accompanied by reduced ferroptosis and alleviated myocardial injury. In summary, these results provide a novel signaling pathway during the progression of acute myocardial infarction, namely Egr-1/miR-15a-5p/GPX4/ferroptosis.