TRB3 mediates vascular remodeling by activating the MAPK signaling pathway in hypoxic pulmonary hypertension

Liraglutide ameliorates high glucose-induced vascular endothelial injury through TRIB3/NF-κB signaling pathway

As one of the most commonly used antidiabetic medications clinically, liraglutide is involved in the protection of vascular endothelium, and whether it can relieve high glucose-induced vascular endothelial damage was unknown. This study aims to address the response of liraglutide (LIRA) on human umbilical vein endothelial cells, as well as to elucidate its possible underlying mechanism. We established a vascular endothelial cell injury model by exposing human umbilical vein endothelial cells (HUVECs) to high glucose, and used LIRA pretreatment before HG treatment to address the endothelial protective effect of LIRA. Our results suggest that LIRA prevented HG-induced HUVEC apoptosis, oxidative stress, inflammasome activation, and pyroptosis. Furthermore, silencing of tribbles homolog 3 (TRIB3) could markedly reduce HG-induced HUVEC apoptosis, ROS level, the expressions of TXNIP, cleaved caspase3, NLRP3, and caspase1, indicating TRIB3 inhibition protected HUVECs against HG-induced vascular endothelial injury. In addition, LIRA restrained NF-κB/IκB-α signaling pathway activation in HUVECs. Thus, LIRA appears to mitigate HG-induced apoptosis, oxidative stress, inflammasome activation, and pyroptosis in HUVECs via regulating the TRIB3/NF-κB/IκB-α signaling pathway. Our study provides new insight into the mechanisms underlying the protective activity of LIRA against the vascular endothelial injury in diabetic vascular complication.

Neutrophils facilitate the epicardial regenerative response after zebrafish heart injury

Despite extensive studies on endogenous heart regeneration within the past 20 years, the players involved in initiating early regeneration events are far from clear. Here, we assessed the function of neutrophils, the first-responder cells to tissue damage, during zebrafish heart regeneration. We detected rapid neutrophil mobilization to the injury site after ventricular amputation, peaking at 1-day post-amputation (dpa) and resolving by 3 dpa. Further analyses indicated neutrophil mobilization coincides with peak epicardial cell proliferation, and recruited neutrophils associated with activated, expanding epicardial cells at 1 dpa. Neutrophil depletion inhibited myocardial regeneration and significantly reduced epicardial cell expansion, proliferation, and activation. To explore the molecular mechanism of neutrophils on the epicardial regenerative response, we performed scRNA-seq analysis of 1 dpa neutrophils and identified enrichment of the FGF and MAPK/ERK signaling pathways. Pharmacological inhibition of FGF signaling indicated its' requirement for epicardial expansion, while neutrophil depletion blocked MAPK/ERK signaling activation in epicardial cells. Ligand-receptor analysis indicated the EGF ligand, hbegfa, is released from neutrophils and synergizes with other FGF and MAPK/ERK factors for induction of epicardial regeneration. Altogether, our studies revealed that neutrophils quickly motivate epicardial cells, which later accumulate at the injury site and contribute to heart regeneration.

Chronic intermittent hypoxia-induced oxidative stress activates TRB3 and phosphorylated JNK to mediate insulin resistance and cell apoptosis in the pancreas

This study explores the potential mechanisms of obstructive sleep apnoea (OSA) complicates type 2 diabetes mellitus (T2DM) by which chronic intermittent hypoxia (CIH) induces insulin resistance and cell apoptosis in the pancreas through oxidative stress. Four- and eight-week CIH rat models were established, and Tempol (100 mg/kg/d), was used as an oxidative stress inhibitor. This study included five groups: 4-week CIH, 4-week CIH-Tempol, 8-week CIH, 8-week CIH-Tempol and normal control (NC) groups. Fasting blood glucose and insulin levels were measured in the serum. The expression levels of 8-hidroxy-2-deoxyguanosine (8-OHdG), tribbles homologue 3 (TRB3), c-Jun N-terminal kinase (JNK), phosphorylated JNK (p-JNK), insulin receptor substrate-1 (IRS-1), phosphorylated IRS-1 (Ser307) (p-IRS-1ser307 ), protein kinase B (AKT), phosphorylated AKT (Ser473) (p-AKTser473 ), B cell lymphoma protein-2 (Bcl-2), cleaved-caspase-3 (Cl-caspase-3), and the islet cell apoptosis were detected in the pancreas. CIH induced oxidative stress in the pancreas. Compared with that in the NC group and CIH-Tempol groups individually, the homeostasis model assessment of insulin resistance (HOMA-IR) and apoptosis of islet cells was increased in the CIH groups. CIH-induced oxidative stress increased the expression of p-IRS-1Ser307 and decreased the expression of p-AKTSer473 . The expression levels of TRB3 and p-JNK were higher in the CIH groups than in both the CIH-Tempol and NC groups. Meanwhile, the expressions of Cl-caspase-3 and Bcl-2 were upregulated and downregulated, respectively, in the CIH groups. Hence, the present study demonstrated that CIH-induced oxidative stress might not only induce insulin resistance but also islet cell apoptosis in the pancreas through TRB3 and p-JNK.

Wogonin attenuates vascular remodeling by inhibiting smooth muscle cell proliferation and migration in hypertensive rat

Wogonin, extracted from the roots of Scutellaria baicalensis Georgi, has been shown to suppress collagen deposition in spontaneously hypertensive rats (SHRs). This study was performed to investigate the role and mechanism of wogonin underlying vascular remodeling in SHRs. After injection of SHRs with 40 mg/kg of wogonin, blood pressure in rats was measured once a week. Masson's trichrome staining was conducted to observe the changes in aortas and mesenteric arteries. Vascular smooth muscle cells (VSMCs) isolated from rat thoracic aortas were treated with Angiotensin II (Ang II; 100 nM) in the presence or absence of varying concentrations of wogonin. The viability and proliferation of VSMCs were examined using Cell Counting Kit-8 assay and 5-ethynyl-2'-deoxyuridine assay, respectively. The migration of VSMCs was examined using wound healing assay and transwell assay. We found that wogonin administration alleviated hypertension, increased lumen diameter, and reduced the thickness of the arterial media in SHRs. Ang II treatment enhanced the viability of VSMCs, which was inhibited by wogonin in a concentration-dependent manner. Wogonin reversed Ang II-induced increases in the viability, proliferation, and migration of VSMCs. Moreover, wogonin inhibited Ang II-induced activation of mitogen-activated protein kinase (MAPK) signaling in VSMCs. Overall, wogonin repressed the proliferative and migratory capacity of VSMCs by regulating the MAPK signaling pathway, thereby attenuating vascular remodeling in hypertensive rats, indicating that wogonin might be a therapeutic agent for the treatment of vascular diseases.

MiR-122-5p as a potential regulator of pulmonary vascular wall cell in idiopathic pulmonary arterial hypertension

MicroRNAs (miRNAs) are versatile regulators of pulmonary arterial remodeling in idiopathic pulmonary arterial hypertension (IPAH). We herein aimed to characterize miRNAs in peripheral blood mononuclear cell (PBMC) and plasma exosomes, and investigate specific miRNA expression in pulmonary artery cells and lung tissues in IPAH. A co-dysregulated miRNA was identified from the miRNA expression profiles of PBMC and plasma exosomes in IPAH. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed the potential function of differentially expressed miRNAs. Real-time quantitative reverse transcription polymerase chain reaction was used to validate the expression of specific miRNAs in hypoxia-induced pulmonary microvascular endothelial cells (PMECs), pulmonary artery smooth muscle cells (PASMCs), pericyte cells (PCs), and lung tissues of patients with IPAH and rats. Finally, the miRNA-mRNA mechanisms of miR-122-5p were predicted. MiR-122-5p was the only co-upregulated miRNA in PBMC and plasma exosomes in patients with IPAH. Functional analysis of differentially expressed miRNAs revealed associations with the GO terms "transcription, DNA-templated," "cytoplasm," and "metal ion binding" in both PBMC and plasma exosomes, KEGG pathway MAPK signaling in PBMC, and KEGG-pathway human papillomavirus infection in plasma exosomes. Hypoxic PMECs and PCs, lung tissue of patients with IPAH, and rats showed increased expression of miR-122-5p, but hypoxic PASMCs showed decreased expression. And miR-122-5p mimics and inhibitor affected cell proliferation. Finally, miR-122-5p was found to potentially target DLAT (in lung tissue) and RIMS1 (in PMECs) in IPAH. According to the dual-luciferase assay, miR-122-5p bound to DLAT or RIMS1. In studies, DLAT imbalance was associated with cell proliferation and migration, RIMS1 is differentially expressed in cancer and correlated with cancer prognosis. Our findings suggest that the miR-122-5p is involved in various biological functions in the adjacent vascular wall cells in IPAH.

Study on Potential Differentially Expressed Genes in Idiopathic Pulmonary Fibrosis by Bioinformatics and Next-Generation Sequencing Data Analysis

Idiopathic pulmonary fibrosis (IPF) is a chronic progressive lung disease with reduced quality of life and earlier mortality, but its pathogenesis and key genes are still unclear. In this investigation, bioinformatics was used to deeply analyze the pathogenesis of IPF and related key genes, so as to investigate the potential molecular pathogenesis of IPF and provide guidance for clinical treatment. Next-generation sequencing dataset GSE213001 was obtained from Gene Expression Omnibus (GEO), and the differentially expressed genes (DEGs) were identified between IPF and normal control group. The DEGs between IPF and normal control group were screened with the DESeq2 package of R language. The Gene Ontology (GO) and REACTOME pathway enrichment analyses of the DEGs were performed. Using the g:Profiler, the function and pathway enrichment analyses of DEGs were performed. Then, a protein-protein interaction (PPI) network was constructed via the Integrated Interactions Database (IID) database. Cytoscape with Network Analyzer was used to identify the hub genes. miRNet and NetworkAnalyst databaseswereused to construct the targeted microRNAs (miRNAs), transcription factors (TFs), and small drug molecules. Finally, receiver operating characteristic (ROC) curve analysis was used to validate the hub genes. A total of 958 DEGs were screened out in this study, including 479 up regulated genes and 479 down regulated genes. Most of the DEGs were significantly enriched in response to stimulus, GPCR ligand binding, microtubule-based process, and defective GALNT3 causes HFTC. In combination with the results of the PPI network, miRNA-hub gene regulatory network and TF-hub gene regulatory network, hub genes including LRRK2, BMI1, EBP, MNDA, KBTBD7, KRT15, OTX1, TEKT4, SPAG8, and EFHC2 were selected. Cyclothiazide and rotigotinethe are predicted small drug molecules for IPF treatment. Our findings will contribute to identification of potential biomarkers and novel strategies for the treatment of IPF, and provide a novel strategy for clinical therapy.

A ring N(CH3)2-based derivative of resveratrol inhibits pulmonary vascular remodeling in hypoxia pulmonary hypertension

Pulmonary artery smooth muscle cells (PASMCs) phenotypic switching and pulmonary artery endothelial cells (PAECs) endothelial-mesenchymal transition (EndMT) are important in promoting pulmonary hypertension (PH)-pulmonary vascular remodeling (PVR). Resveratrol can efficiently inhibit the proliferation of PASMCs, but its application is limited due to its low bioavailability and solubility. In this study, we modified resveratrol to assess the role of A ring N(CH3)2-based derivatives of resveratrol (Res4) in PVR-PASMCs phenotypic switching and PVR-PAECs EndMT. Chemical methods were used for the preparation of Res4; NMRS and HPLC were used to authenticate Res4. Mice developed PVR after 4 weeks of hypoxia (10% O2). Res4 (50 mg/kg/d) attenuated right ventricular systolic pressure, right ventricular hypertrophy, and PVR. PASMCs developed phenotypic switching and PAECs developed EndMT after 2 days of hypoxia (3% O2). Res4 (10 μM) could inhibit PASMCs and PAECs viability. Res4 could decrease proliferating cell nuclear antigen (PCNA) and osteopontin (OPN) expression, and increase α-smooth muscle actin (α-SMA) and vimentin expression in PASMCs. It could also decrease PCNA, α-SMA, vimentin expression and increase platelet endothelial cell adhesion molecule (CD31) expression in PAECs. Notably, Res4 inhibited the phosphorylation levels of mitogen-activated protein kinase kinase (MEK), extracellular signal-regulated protein kinase (ERK), Jun-N-terminal kinase (JNK), and p38 kinase in hypoxia-treated PASMCs and PAECs, indicating MAPK pathway may be involved in Res4-induced inhibition of PASMCs phenotypic switching and PAECs EndMT. Our data demonstrated that Res4 exerts antiproliferative effects by regulating PASMCs phenotypic switching and PAECs EndMT. Res4 may be potentially used as a drug against PH-PVR.

Normobaric hypoxia shows enhanced FOXO1 signaling in obese mouse gastrocnemius muscle linked to metabolism and muscle structure and neuromuscular innervation

Skeletal muscle relies on mitochondria for sustainable ATP production, which may be impacted by reduced oxygen availability (hypoxia). Compared with long-term hypoxia, the mechanistic in vivo response to acute hypoxia remains elusive. Therefore, we aimed to provide an integrated description of the Musculus gastrocnemius response to acute hypoxia. Fasted male C57BL/6JOlaHsd mice, fed a 40en% fat diet for six weeks, were exposed to 12% O2 normobaric hypoxia or normoxia (20.9% O2) for six hours (n = 12 per group). Whole-body energy metabolism and the transcriptome response of the M. gastrocnemius were analyzed and confirmed by acylcarnitine determination and Q-PCR. At the whole-body level, six hours of hypoxia reduced energy expenditure, increased blood glucose and tended to decreased the respiratory exchange ratio (RER). Whole-genome transcriptome analysis revealed upregulation of forkhead box-O (FOXO) signalling, including an increased expression of tribbles pseudokinase 3 (Trib3). Trib3 positively correlated with blood glucose levels. Upregulated carnitine palmitoyltransferase 1A negatively correlated with the RER, but the significantly increased in tissue C14-1, C16-0 and C18-1 acylcarnitines supported that β-oxidation was not regulated. The hypoxia-induced FOXO activation could also be connected to altered gene expression related to fiber-type switching, extracellular matrix remodeling, muscle differentiation and neuromuscular junction denervation. Our results suggest that a six-hour exposure of obese mice to 12% O2 normobaric hypoxia impacts M. gastrocnemius via FOXO1, initiating alterations that may contribute to muscle remodeling of which denervation is novel and warrants further investigation. The findings support an early role of hypoxia in tissue alterations in hypoxia-associated conditions such as aging and obesity.

Restoration of miR-328a-5p function curtails hypoxic pulmonary hypertension through a mechanism involving PIN1/GSK3β/β-catenin axis

Recent evidence has highlighted the involvement of microRNAs (miRs) in hypoxic pulmonary hypertension (PH), which can be induced under hypoxic conditions. We intend to explore whether the miR-328a-5p/PIN1 axis affects hypoxic PH by regulating the GSK3β/β-catenin signaling pathway. The GEO database was retrieved to single out key miRs affecting hypoxic PH. It was observed that downregulation of miR-328a-5p occurred in hypoxia-induced PH samples. The binding affinity between miR-328a-5p to PIN1 was predicted by a bioinformatics tool and verified using a dual luciferase reporter gene assay. Rat primary pulmonary artery smooth muscle cells (PASMCs) were exposed to hypoxia for in vitro cell experiments. miR-328a-5p could target and downregulate PIN1 expression, leading to suppressed GSK3β/β-catenin activation. In addition, GSK3β/β-catenin inactivation curtailed hypoxia-induced vascular inflammatory responses and proliferation and migration in PASMCs in vitro. A hypoxic PH model was established in SD rats to observe the effects of miR-328a-5p on hemodynamic parameters and right heart remodeling. It was demonstrated in vivo that miR-328a-5p downregulated PIN1 expression to suppress GSK3β/β-catenin signaling, thereby reducing the vascular inflammatory response and alleviating disease progression in hypoxia-induced PH rats. The evidence provided by our study highlighted the involvement of miR-328a-5p in the translational suppression of PIN1 and the blockade of the GSK3β/β-catenin signaling pathway, resulting in attenuation of hypoxic PH progression.

4-Terpineol attenuates pulmonary vascular remodeling via suppressing PI3K/Akt signaling pathway in hypoxia-induced pulmonary hypertension rats

The hyperproliferation of pulmonary arterial smooth muscle cells (PASMCs) plays a pivotal role in pulmonary arterial remodeling (PAR) of hypoxia-induced pulmonary hypertension (HPH). 4-Terpineol is a constituent of Myristic fragrant volatile oil in Santan Sumtang. Our previous study found that Myristic fragrant volatile oil alleviated PAR in HPH rats. However, the effect and pharmacological mechanism of 4-terpineol in HPH rats remain unexplored. Male Sprague-Dawley rats were exposed to hypobaric hypoxia chamber (simulated altitudes of 4500 m) for 4 weeks to establish an HPH model in this study. During this period, rats were intragastrically administrated with 4-terpineol or sildenafil. After that, hemodynamic indexes and histopathological changes were assessed. Moreover, a hypoxia-induced cellular proliferative model was established by exposing PASMCs to 3% O2. PASMCs were pretreated with 4-terpineol or LY294002 to explore whether 4-terpineol targeted PI3K/Akt signaling pathway. The PI3K/Akt-related proteins expression was also accessed in lung tissues of HPH rats. We found that 4-terpineol attenuated mPAP and PAR in HPH rats. Then, cellular experiments showed 4-terpineol inhibited hypoxia-induced PASMCs proliferation via down-regulating PI3K/Akt expression. Furthermore, 4-terpineol decreased the p-Akt, p-p38, and p-GSK-3β protein expression, as well as reduced the PCNA, CDK4, Bcl-2 and Cyclin D1 protein levels, while increasing levels of cleaved caspase 3, Bax, and p27kip1in lung tissues of HPH rats. Our results suggested that 4-terpineol mitigated PAR in HPH rats by inhibiting the proliferation and inducing apoptosis of PASMCs through suppression of the PI3K/Akt-related signaling pathway.

Insights into Endothelin Receptors in Pulmonary Hypertension

Pulmonary hypertension (PH) is a disease which affects the cardiopulmonary system; it is defined as a mean pulmonary artery pressure (mPAP) > 20 mmHg as measured by right heart catheterization at rest, and is caused by complex and diverse mechanisms. In response to stimuli such as hypoxia and ischemia, the expression and synthesis of endothelin (ET) increase, leading to the activation of various signaling pathways downstream of it and producing effects such as the induction of abnormal vascular proliferation during the development of the disease. This paper reviews the regulation of endothelin receptors and their pathways in normal physiological processes and disease processes, and describes the mechanistic roles of ET receptor antagonists that are currently approved and used in clinical studies. Current clinical researches on ET are focused on the development of multi-target combinations and novel delivery methods to improve efficacy and patient compliance while reducing side effects. In this review, future research directions and trends of ET targets are described, including monotherapy and precision medicine.

TRIB3 promoter 33 bp VNTR is associated with the risk of cerebrovascular disease in type 2 diabetic patients

Previous studies have demonstrated that TRIB3 is closely related to insulin resistance, metabolic disorders and vascular diseases. Recently, it was reported that a 33 bp variable number of tandem repeats (VNTR) located in the TRIB3 promoter could considerably alter its transcriptional activity. Nonetheless, whether the shift of TRIB3 transcriptional activity has the effect of inducing diabetic vascular complications is still unclear. Therefore, in our study, we aimed to explore the relationship between the TRIB3 33bp VNTR and diabetic vascular complications. The TRIB3 33bp VNTR polymorphisms were determined by PCR and Sanger sequencing, a total of 798 eligible Chinese patients with type 2 diabetes (T2DM) were included in our study and then evaluated with clinical data. After adjusting for age, gender, BMI, smoking history, drinking history and duration of diabetes, we found that the high number of 33 bp tandem repeats (repeats>8) was significantly associated with an increase in the risk of cerebrovascular diseases compared with the low number of 33 bp tandem repeats (repeats≤6) in patients with T2DM(OR 2.66, 95% CI 1.29–5.47, p = 0.008). The intermediate number of 33bp tandem repeats (6 < repeat≤8) was markedly associated with a decreased risk of diabetic retinopathy compared with the low number of tandem repeats (OR 0.65, 95% CI 0.46–0.91, p = 0.012). Adjusting for gender, age and BMI, there was a significant difference in DBP levels among patients with the number of different 33 bp tandem repeats (Low vs. Intermediate vs. High, 81.6 ± 12.8 vs. 79.8 ± 12.4 vs. 78.7 ± 12.6 mmHg; p = 0.045). Subgroup analysis found that TRIB3 VNTR was significantly correlated with the difference in systolic blood pressure (SBP) in T2DM patients taking ACEI/ARB drugs (Low vs. Intermediate vs. High, 146.27 ± 18.23 vs. 140.01 ± 19.91 vs. 140.77 ± 18.64 mmHg; p = 0.018). Our results indicated that TRIB3 promoter 33bp VNTR is related to vascular diseases in T2DM patients, and may serve as a new biomarker for individualized prevention and therapy of T2DM.