PAF enhances MMP-2 production in rat aortic VSMCs via a β-arrestin2-dependent ERK signaling pathway

Assessment of Atherosclerosis in Ischemic Stroke by means of Ultrasound of Extracranial/Intracranial Circulation and Serum, Urine, and Tissue Biomarkers

It is a common practice to take into consideration age, diabetes, smoking, treated and untreated systolic blood pressure, total cholesterol, and high-density lipoprotein cholesterol for the prediction of atherosclerosis and stroke. There are, however, ultrasound markers in use for the assessment of atherosclerosis and the evaluation of stroke risk. Two areas of investigation are of interest: the carotid artery and the intracranial arterial circulation. Again, within the domain of the carotid artery, two ultrasonic markers have attracted our attention: intima media thickness of the carotid artery and the presence of carotid plaque with its various focal characteristics. In the domain of intracranial circulation, the presence of arterial stenosis and the recruitment of collaterals are considered significant ultrasonic markers for the above-mentioned purpose. On the other hand, a series of serum, urine, and tissue biomarkers are found to be related to atherosclerotic disease. Future studies might address the issue of whether the addition of proven ultrasonic carotid indices to the aforementioned serum, urine, and tissue biomarkers could provide the vascular specialist with a better assessment of the atherosclerotic load and solidify their position as surrogate markers for the evaluation of atherosclerosis and stroke risk.

Biomarkers in the Light of the Etiopathology of IC/BPS

In this review, we focused on putatively interesting biomarkers of interstitial cystitis/bladder pain syndrome (IC/BPS) in relation to the etiopathology of this disease. Since its etiopathology is still under discussion, the development of novel biomarkers is critical for the correct classification of the patients in order to open personalized treatment options, on the one hand, and to separate true IC/BPS from the numerous confusable diseases with comparable symptom spectra on the other hand. There is growing evidence supporting the notion that the classical or Hunner-type IC (HIC) and the non-Hunner-type IC (NHIC) are different diseases with different etiopathologies and different pathophysiology at the full-blown state. While genetic alterations indicate close relationship to allergic and autoimmune diseases, at present, the genetic origin of IC/BPS could be identified. Disturbed angiogenesis and impairment of the microvessels could be linked to altered humoral signaling cascades leading to enhanced VEGF levels which in turn could enhance leucocyte and mast cell invasion. Recurrent or chronic urinary tract infection has been speculated to promote IC/BPS. New findings show that occult virus infections occurred in most IC/BPS patients and that the urinary microbiome was altered, supporting the hypothesis of infections as major players in IC/BPS. Environmental and nutritional factors may also influence IC/BPS, at least at a late state (e.g., cigarette smoking can enhance IC/BPS symptoms). The damage of the urothelial barrier could possibly be the result of many different causality chains and mark the final state of IC/BPS, the causes of this development having been introduced years ago. We conclude that the etiopathology of IC/BPS is complex, involving regulatory mechanisms at various levels. However, using novel molecular biologic techniques promise more sophisticated analysis of this pathophysiological network, resulting in a constantly improvement of our understanding of IC/BPS and related diseases.

Remifentanil preconditioning promotes liver regeneration via upregulation of β-arrestin 2/ERK/cyclin D1 pathway

Remifentanil is a potent, short-acting opioid analgesic drug that can protect tissues from ischemia and reperfusion injury though anti-inflammatory effects. However, the utility of remifentanil in liver regeneration after hepatectomy is not known. Using a 70% hepatectomy mouse model (PHx), we found that preconditioning animals with 4 μg/kg remifentanil enhanced liver regeneration through supporting hepatocyte proliferation but not through anti-inflammatory effects. These effects were also phenocopied in vitro where 40 mM remifentanil promoted the proliferation of primary mouse hepatocyte cultures. We further identified that remifentanil treatment increased the expression of β-arrestin 2 in vivo and in vitro. Demonstrating specificity, remifentanil preconditioning failed to promote liver regeneration in liver-specific β-arrestin 2 knockout (CKO) mice subjected to PHx. While remifentanil increased the expression of activated (phosphorylated)-ERK and cyclin D1 in PHx livers, their levels were not significantly changed in remifentanil-treated CKO mice nor in WT mice pretreated with the ERK inhibitor U0126. Our findings suggest that remifentanil promotes liver regeneration via upregulation of a β-arrestin 2/ERK/cyclin D1 axis, with implications for improving regeneration process after hepatectomy.

Sodium Selenite Attenuates Balloon Injury-Induced and Monocrotaline-Induced Vascular Remodeling in Rats

Vascular remodeling (VR), induced by the massive proliferation and reduced apoptosis of vascular smooth muscle cells (VSMCs), is primarily responsible for many cardiovascular conditions, such as restenosis and pulmonary arterial hypertension. Sodium selenite (SSE) is an inorganic selenium, which can block proliferation and stimulate apoptosis of tumor cells; still, its protective effects on VR remains unknown. In this study, we established rat models with carotid artery balloon injury and monocrotaline induced pulmonary arterial hypertension and administered them SSE (0.25, 0.5, or 1 mg/kg/day) orally by feeding tube for 14 consecutive days. We found that SSE treatment greatly ameliorated the development of VR as evidenced by an improvement of its characteristic features, including elevation of the ratio of carotid artery intimal area to medial area, right ventricular hypertrophy, pulmonary arterial wall hypertrophy and right ventricular systolic pressure. Furthermore, PCNA and TUNEL staining of the arteries showed that SSE suppressed proliferation and enhanced apoptosis of VSMCs in both models. Compared with the untreated VR rats, lower expression of PCNA and CyclinD1, but higher levels of Cleaved Caspase-3 and Bax/Bcl-2 were observed in the SSE-treated rats. Moreover, the increased protein expression of MMP2, MMP9, p-AKT, p-ERK, p-GSK3β and β-catenin that occurred in the VR rats were significantly inhibited by SSE. Collectively, treatment with SSE remarkably attenuates the pathogenesis of VR, and this protection may be associated with the inhibition of AKT and ERK signaling and prevention of VSMC’s dysfunction. Our study suggest that SSE is a potential agent for treatment of VR-related diseases.

FRZB as a key molecule in abdominal aortic aneurysm progression affecting vascular integrity

Abdominal aortic aneurysm (AAA), when ruptured, results in high mortality. The identification of molecular pathways involved in AAA progression is required to improve AAA prognosis. The aim of the present study was to assess the key genes for the progression of AAA and their functional role. Genomic and clinical data of three independent cohorts were downloaded from the National Center for Biotechnology Information (NCBI) Gene Expression Omnibus (GEO) (GSE57691, GSE7084, and GSE98278). To develop AAA diagnosis and progression-related differentially expressed genes (DEGs), we used a significance analysis of microarray (SAM). Spearman correlation test and gene set analysis were performed to identify potential enriched pathways for DEGs. Only the Frizzled-related protein (FRZB) gene and chromosome 1 open reading frame 24 (C1orf24) exhibited significant down-regulation in all analyses. With FRZB, the pathways were associated with RHO GTPase and elastin fiber formation. With C1orf24, the pathways were elastic fiber formation, extracellular matrix organization, and cell–cell communication. Since only FRZB was evolutionally conserved in the vertebrates, function of FRZB was validated using zebrafish embryos. Knockdown of frzb remarkably reduced vascular integrity in zebrafish embryos. We believe that FRZB is a key gene involved in AAA initiation and progression affecting vascular integrity.

Plasma Metabolomics Analysis Identifies Abnormal Energy, Lipid, and Amino Acid Metabolism in Abdominal Aortic Aneurysms

Background

Abdominal aortic aneurysm (AAA) is a complicated aortic dilatation disease. Metabolomics is an emerging system biology method. This aim of this study was to identify abnormal metabolites and metabolic pathways associated with AAA and to discover potential biomarkers that could affect the size of AAAs.

Material/Methods

An untargeted metabolomic method was used to analyze the plasma metabolic profiles of 39 patients with AAAs and 30 controls. Multivariate analysis methods were used to perform differential metabolite screening and metabolic pathway analysis. Cluster analysis and univariate analysis were performed to identify potential metabolites that could affect the size of an AAA.

Results

Forty-five different metabolites were identified with an orthogonal projection to latent squares-discriminant analysis model and the differences between them in the patients with AAAs and the control group were compared. A variable importance in the projection score >1 and P<0.05 were considered statistically significant. In patients with AAAs, the pathways involving metabolism of alanine, aspartate, glutamate, D-glutamine, D-glutamic acid, arginine, and proline; tricarboxylic acid cycling; and biosynthesis of arginine are abnormal. The progression of an AAA may be related to 13 metabolites: citric acid, 2-oxoglutarate, succinic acid, coenzyme Q1, pyruvic acid, sphingosine-1-phosphate, platelet-activating factor, LysoPC (16: 00), lysophosphatidylcholine (18: 2(9Z,12Z)/0: 0), arginine, D-aspartic acid, and L- and D-glutamine.

Conclusions

An untargeted metabolomic analysis using ultraperformance liquid chromatography-tandem mass spectrometry identified metabolites that indicate disordered metabolism of energy, lipids, and amino acids in AAAs.

CTRP9 induces macrophages polarization into M1 phenotype through activating JNK pathway and enhances VSMCs apoptosis in macrophages and VSMCs co-culture system

Inflammation plays a critical role in the development of atherosclerosis (AS), which has been identified as a major predisposing factor for stroke. Macrophages and VSMCs are associated with plaque formation and progression. Macrophages can dynamically change into two main functional phenotypes, namely M1 and M2, they can produce either pro-inflammatory or anti-inflammatory factors which may affect the outcome of inflammation. As a member of CTRPs family, CTRP9 has been reported play important protective roles in the cardiovascular system. However, whether CTRP9 can regulate macrophage activation status in inflammatory responses and have effect on VSMCs behaviors in co-culture system have not been fully investigated. In the present study, using peritoneal macrophages treated with CTRP9, we found that CTRP9 facilitated macrophages towards M1 phenotype, promoted TNF-α secretion and MMPs expression. CTRP9 showed synergistic effect with LPS in inducing M1 macrophages. In macrophages-VSMCs co-culture system, apoptosis and down-regulated proliferation of VSMCs were accelerated with CTRP9-treated macrophages. Then we attempted to explore the underlying molecular mechanisms of CTRP9 resulting in M1 activation. The c-Jun NH2-terminal kinases (JNK) are members of the mitogen activated protein kinases (MAPK) family, plays a central role in the cell stress response, with outcomes ranging from cell death to cell proliferation and survival. We found JNK expression was upregulated following CTRP9 stimulation, and inhibiting JNK phosphorylation level was associated with decreased expression of M1 markers and TNF-α concentration. Moreover, VSMCs apoptosis were ameliorated after inhibition of JNK. These results suggested that CTRP9 may promote macrophage towards M1 activation status through JNK signaling pathway activation.

Thymoquinone suppresses platelet-derived growth factor-BB-induced vascular smooth muscle cell proliferation, migration and neointimal formation

The excessive proliferation and migration of vascular smooth muscle cells (VSMCs) are mainly responsible for vascular occlusion diseases, such as pulmonary arterial hypertension and restenosis. Our previous study demonstrated thymoquinone (TQ) attenuated monocrotaline‐induced pulmonary arterial hypertension. The aim of the present study is to systematically examine inhibitory effects of TQ on platelet‐derived growth factor‐BB (PDGF‐BB)–induced proliferation and migration of VSMCs in vitro and neointimal formation in vivo and elucidate the potential mechanisms. Vascular smooth muscle cells were isolated from the aorta in rats. Cell viability and proliferation were measured in VSMCs using the MTT assay. Cell migration was detected by wound healing assay and Transwell assay. Alpha‐smooth muscle actin (α‐SMA) and Ki‐67‐positive cells were examined by immunofluorescence staining. Reactive oxygen species (ROS) generation and apoptosis were measured by flow cytometry and terminal deoxyribonucleotide transferase–mediated dUTP nick end labelling (TUNEL) staining, respectively. Molecules including the mitochondria‐dependent apoptosis factors, matrix metalloproteinase 2 (MMP2), matrix metalloproteinase 9 (MMP9), PTEN/AKT and mitogen‐activated protein kinases (MAPKs) were determined by Western blot. Neointimal formation was induced by ligation in male Sprague Dawley rats and evaluated by HE staining. Thymoquinone inhibited PDGF‐BB–induced VSMC proliferation and the increase in α‐SMA and Ki‐67‐positive cells. Thymoquinone also induced apoptosis via mitochondria‐dependent apoptosis pathway and p38MAPK. Thymoquinone blocked VSMC migration by inhibiting MMP2. Finally, TQ reversed neointimal formation induced by ligation in rats. Thus, TQ is a potential candidate for the prevention and treatment of occlusive vascular diseases.

Aberrant expression of PAFAH1B3 associates with poor prognosis and affects proliferation and aggressiveness in hypopharyngeal squamous cell carcinoma

Background

Hypopharyngeal squamous cell carcinoma (HSCC) is among the most lethal tumors encountered in the head and neck, and currently lacks satisfactory therapeutic targets. Platelet activating factor acetylhydrolase 1B3 (PAFAH1B3), a cancer-relevant metabolic driver, is reported to play a critical role in controlling tumorigenesis and aggressiveness in several types of cancers. However, the role of PAFAH1B3 in HSCC progression has not yet been identified.

Methods

The expression pattern of PAFAH1B3 was examined using immunohistochemistry in 83 HSCC tumor tissues and 44 paired adjacent non-tumor samples. Univariate and multivariate analyses were conducted to explore its association with prognosis of HSCC. In vitro loss-of-function assays were performed to explore the impact of PAFAH1B3 knockdown on the biological phenotype of the human HSCC cell line, ie, FaDu cells.

Results

PAFAH1B3 was overly expressed in the HSCC tumor tissues compared with the adjacent non-tumor samples. Moreover, high expression of PAFAH1B3 was positively correlated with cervical lymph node metastasis. PAFAH1B3 overexpression was associated with poor outcome in HSCC, but it was not an independent prognostic indicator. Furthermore, in vitro loss-of function experiments demonstrated that PAFAH1B3 knockdown suppressed cell proliferation by inducing apoptosis and disrupting cell cycle process, and the migratory and invasive capacities were also attenuated in the absence of PAFAH1B3.

Conclusion

This study for the first time demonstrated the clinical value and the role of PAFAH1B3 in the biological function of HSCC. This work suggested that PAFAH1B3 might serve as a potential therapeutic target for HSCC patients.

Prognostic Value of MicroRNAs in Coronary Artery Diseases: A Meta-Analysis

PURPOSE

Coronary artery diseases (CADs) are the leading causes of death in the world. Recent studies have reported that differentially expressed microRNAs (miRNAs) are associated with prognosis or major adverse cardiac events (MACEs) in CAD patients. In a previous meta-analysis, the authors made serious mistakes that we aimed to correct through an updated systematic review and meta-analysis of the prognostic value of altered miRNAs in patients with CADs.

MATERIALS AND METHODS

We performed a systematic search of MEDLINE (from inception to May 2017) and EMBASE (from inception to May 2017) for English-language publications. Studies of CADs with results on miRNAs that reported survival data or MACEs were included. Data were extracted from each publication independently by two reviewers.

RESULTS

After reviewing 515 articles, a total eight studies were included in this study. We measured pooled hazard ratios (HRs) and 95% confidence intervals (CIs) of miRNA 133a with a fixed-effect model (pooled HR, 2.35; 95% CI, 1.56-3.55). High expression of miRNA 133a, 208b, 126, 197, 223, and 122-5p were associated with high mortality. Additionally, high levels of miRNA 208b, 499-5p, 134, 328, and 34a were related with MACEs.

CONCLUSION

The present study confirmed that miRNA 133a, which was associated with high mortality in CAD patients, holds prognostic value in CAD. More importantly, this study corrected issues raised against a prior meta-analysis and provides accurate information.

Biased Agonism/Antagonism of Cardiovascular GPCRs for Heart Failure Therapy

G protein-coupled receptors (GPCRs) are among the most important drug targets currently used in clinic, including drugs for cardiovascular indications. We now know that, in addition to activating heterotrimeric G protein-dependent signaling pathways, GPCRs can also activate G protein-independent signaling, mainly via the βarrestins. The major role of βarrestin1 and -2, also known as arrestin2 or -3, respectively, is to desensitize GPCRs, i.e., uncoupled them from G proteins, and to subsequently internalize the receptor. As the βarrestin-bound GPCR recycles inside the cell, it serves as a signalosome transducing signals in the cytoplasm. Since both G proteins and βarrestins can transduce signals from the same receptor independently of each other, any given GPCR agonist might selectively activate either pathway, which would make it a biased agonist for that receptor. Although this selectivity is always relative (never absolute), in cases where the G protein- and βarrestin-dependent signals emanating from the same GPCR result in different cellular effects, pharmacological exploitation of GPCR-biased agonism might have therapeutic potential. In this chapter, we summarize the GPCR signaling pathways and their biased agonism/antagonism examples discovered so far that can be exploited for heart failure treatment. We also highlight important issues that need to be clarified along the journey of these ligands from bench to the clinic.

Ginkgolide B Suppresses TLR4-Mediated Inflammatory Response by Inhibiting the Phosphorylation of JAK2/STAT3 and p38 MAPK in High Glucose-Treated HUVECs

Aim

Ginkgolide B is a Ginkgo biloba leaf extract that has been identified as a natural platelet-activating factor receptor (PAFR) antagonist. We investigated the effect of ginkgolide B on high glucose-induced TLR4 activation in human umbilical vein endothelial cells (HUVECs).

Methods

Protein expression was analyzed by immunoblotting. Small-interfering RNA (siRNA) was used to knock down PAFR and TLR4 expression.

Results

Ginkgolide B suppressed the expression of TLR4 and MyD88 that was induced by high glucose. Ginkgolide B also reduced the levels of platelet endothelial cell adhesion molecule-1, interleukin-6, and monocyte chemotactic protein 1. Further, we examined the association between PAFR and TLR4 by coimmunoprecipitation. The result showed that high glucose treatment caused the binding of PAFR and TLR4, whereas ginkgolide B abolished this binding. The functional analysis indicated that PAFR siRNA treatment reduced TLR4 expression, and TLR4 siRNA treatment decreased PAFR expression in high glucose-treated HUVECs, further supporting the coimmunoprecipitation data. Ginkgolide B inhibited the phosphorylation of Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) and p38 mitogen-activated protein kinase (MAPK).

Conclusion

Ginkgolide B exerted protective effects by inhibiting the TLR4-mediated inflammatory response in high glucose-treated endothelial cells. The mechanism of action of ginkgolide B might be associated with inhibition of the JAK2/STAT3 and p38 MAPK phosphorylation.

In Vivo Effects of Long-Term Cigarette Smoke Exposure on Mammary Tissue in Mice

Cigarette smoking is the leading cause of preventable death worldwide and has been linked to the development and progression of cancer. Many cohort studies have described the link between patients with breast cancer and those with long-term smoking history. Despite the claim of correlation, the mechanism by which cigarette smoke alters normal breast epithelial cells and stroma and contributes to tumor cell growth remains undefined. To investigate whether cigarette smoke promotes ductal epithelial cell hyperplasia by stimulating stromal endothelial cell proliferation, we exposed mice to cigarette smoke for 6 months. We observed epithelial proliferation, increased fibrosis, increased vascularity, and mast cell infiltration. This is the first study to look at the in vivo changes in the breast after long-term cigarette smoke exposure and provides a novel insight to understanding how cigarette smoke contributes to early changes that may contribute to tumor formation and progression. In conclusion, this study suggests that cigarette smoke modulates key stromal-epithelial interactions to support increased angiogenesis, desmoplasia, and abnormal ductal epithelial cell growth.

Alpha1a-Adrenoceptor Genetic Variant Triggers Vascular Smooth Muscle Cell Hyperproliferation and Agonist Induced Hypertrophy via EGFR Transactivation Pathway

α_1a Adrenergic receptors (α_1aARs) are the predominant AR subtype in human vascular smooth muscle cells (SMCs). α_1aARs in resistance vessels are crucial in the control of blood pressure, yet the impact of naturally occurring human α_1aAR genetic variants in cardiovascular disorders remains poorly understood. To this end, we present novel findings demonstrating that 3D cultures of vascular SMCs expressing human α_1aAR-247R (247R) genetic variant demonstrate significantly increased SMC contractility compared with cells expressing the α_1aAR-WT (WT) receptor. Stable expression of 247R genetic variant also triggers MMP/EGFR-transactivation dependent serum- and agonist-independent (constitutive) hyperproliferation and agonist-dependent hypertrophy of SMCs. Agonist stimulation reduces contractility Using pathway-specific inhibitors we determined that the observed hyperproliferation of 247R-expressing cells is triggered via β-arrestin1/Src/MMP-2/EGFR/ERK-dependent mechanism. MMP-2-specific siRNA inhibited 247R-triggered hyperproliferation indicating MMP-2 involvement in 247R-triggered hyperproliferation in SMCs. β-arrestin1-specific shRNA also inhibited 247R-triggered hyperproliferation but did not affect hypertrophy in 247R-expressing SMCs, indicating that agonist-dependent hypertrophy is independent of β-arrestin1. Our data reveal that in different cardiovascular cells the same human receptor genetic variant can activate alternative modulators of the same signaling pathway. Thus, our findings in SMCs demonstrate that depending on the type of cells expressing the same receptor (or receptor variant), different target-specific inhibitors could be used to modulate aberrant hyperproliferative or hypertrophic pathways in order to restore normal phenotype.

SIRT1 attenuates PAF-induced MMP-2 production via down-regulation of PAF receptor expression in vascular smooth muscle cells

Silent mating type information regulation 2 homolog 1 (SIRT1) is known as a key regulator in the protection of various vascular disorders, however, no direct evidences have been reported in the progression of atherosclerosis. Considering the pivotal role of matrix metalloproteinase-2 (MMP-2) in plaque destabilization, this study investigated the role of SIRT1 on MMP-2 production in vascular smooth muscle cells (VSMCs) induced by platelet activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine). In VSMCs stimulated with resveratrol, SIRT1 activator, PAF receptor (PAFR) was internalized and then its protein levels were diminished. It was attenuated in cells pretreated with proteasome or lysosome inhibitor. Also, the degradation of PAFR in SIRT1-stimulated cells was significantly attenuated by β-arrestin2 depletion. In cells treated with nicotinamide, SIRT1 deacetylase inhibitor, PAFR internalization by resveratrol or reSIRT1 was inhibited, demonstrating that deacetylation of SIRT1 is an important step in SIRT1-induced PAFR down-regulation. Moreover, PAF-induced MMP-2 production in VSMCs and aorta was attenuated by resveratrol. In the aorta of SIRT1 transgenic mice, the PAF-induced MMP-2 expression was prominently attenuated compared to that in wild type mice. Taken together, it was suggested that SIRT1 down-regulated PAFR in VSMCs via β-arrestin2-mediated internalization and degradation, leading to an inhibition of PAF-induced MMP-2 production.

Angiotensin II increases matrix metalloproteinase 2 expression in human aortic smooth muscle cells via AT1R and ERK1/2

Increased levels of angiotensin II (Ang II) and activated matrix metalloproteinase 2 (MMP-2) produced by human aortic smooth muscle cells (human ASMCs) have recently been implicated in the pathogenesis of thoracic aortic aneurysm (TAA). Additionally, angiotensin II type 1 receptor (AT1R)-mediated extracellular signal-regulated kinase (ERK)1/2 activation contributes to TAA development in Marfan Syndrome. However, there is scant data regarding the relationship between Ang II and MMP-2 expression in human ASMCs. Therefore, we investigated the effect of Ang II on MMP-2 expression in human ASMCs and used Western blotting to identify the Ang II receptors and intracellular signaling pathways involved. Reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescence data demonstrated that Ang II receptors were expressed on human ASMCs. Additionally, Ang II increased the expression of Ang II type 2 receptor (AT2R) but not AT1R at both the transcriptional and translational levels. Furthermore, Western blotting showed that Ang II increased MMP-2 expression in human ASMCs in a dose- and time-dependent manner. This response was completely inhibited by the AT1R inhibitor candesartan but not by the AT2R blocker PD123319. In addition, Ang II-induced upregulation of MMP-2 was mediated by the activation of ERK1/2, whereas p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun N-terminal kinase (JNK) had no effect on this process. In conclusion, these results indicate that Ang II can increase the expression of MMP-2 via AT1 receptor and ERK1/2 signaling pathways in human ASMCs and suggest that antagonists of AT1R and ERK1/2 may be useful for treating TAAs.