Nonbone Marrow CD34+ Cells Are Crucial for Endothelial Repair of Injured Artery.

[Figure: see text].

TNF-α-Induce Protein 8-Like 1 Inhibits Hepatic Steatosis, Inflammation, and Fibrosis by Suppressing Polyubiquitination of Apoptosis Signal-Regulating Kinase 1.

BACKGROUND AND AIMS: Characterized by hepatocyte steatosis, inflammation, and fibrosis, NASH is a complicated process that contributes to end-stage liver disease and, eventually, HCC. TNF-α-induced protein 8-like 1 (TIPE1), a new member of the TNF-α-induced protein 8 family, has been explored in immunology and oncology research; but little is known about its role in metabolic diseases. APPROACH AND RESULTS: Here, we show that hepatocyte-specific deletion of TIPE1 exacerbated diet-induced hepatic steatosis, inflammation, and fibrosis as well as systemic metabolic disorders during NASH pathogenesis. Conversely, hepatocyte-specific overexpression of TIPE1 dramatically prevented the progression of these abnormalities. Mechanically, TIPE1 directly interacted with apoptosis signal-regulating kinase 1 (ASK1) to suppress its TNF receptor-associated factor 6 (TRAF6)-catalyzed polyubiquitination activation upon metabolic challenge, thereby inhibiting the downstream c-Jun N-terminal kinase and p38 signaling pathway. Importantly, dramatically reduced TIPE1 expression was observed in the livers of patients with NAFLD, suggesting that TIPE1 might be a promising therapeutic target for NAFLD and related metabolic diseases. CONCLUSIONS: TIPE1 protects against hepatic steatosis, inflammation, and fibrosis through directly binding ASK1 and restraining its TRAF6-catalyzed polyubiquitination during the development of NASH. Therefore, targeting TIPE1 could be a promising therapeutic approach for NAFLD treatment.

Macrophage-derived MMP-8 determines smooth muscle cell differentiation from adventitia stem/progenitor cells and promotes neointima hyperplasia.

AIMS: Emerging evidence has suggested that adventitia stem/progenitor cells (AdSPCs) migrate into the intima of arteries in response to injury, where they differentiate towards smooth muscle cells (SMCs) and participate in neointimal hyperplasia. We have previously identified matrix metalloproteinase-8 (MMP8) as a key player in atherogenesis. In this study, we aimed to investigate the functional roles of macrophage-derived MMP8 in AdSPC differentiation and injury-induced arterial remodelling. METHODS AND RESULTS: We first observed an important role for MMP8 in SMC differentiation from embryonic stem cells, but this effect was not seen in AdSPCs. Instead, through macrophages/AdSPCs co-culture and macrophage conditional culture medium studies, we have demonstrated that the MMP8 protein secreted from macrophages promotes SMC differentiation from AdSPCs. Mechanistically, we showed that macrophage-derived MMP8 promotes SMC differentiation from AdSPCs through modulating transforming growth factor-ß activity and a disintegrin and metalloproteinase domain-containing protein 10 (ADAM10)/Notch1 signalling. We further demonstrated that the binding site for CBF1, Suppressor of Hairless, and Lag-1 (CSL) within SMC gene promoters is responsible for Notch1 mediated SMC differentiation. Finally, we demonstrated that macrophage-derived MMP8 increased injury-induced neointimal SMC hyperplasia by activating ADAM10/Notch1 signalling. CONCLUSIONS: We have identified macrophage-derived MMP8 as a regulator in SMC differentiation from AdSPCs and neointimal SMC hyperplasia in response to injury. Our data provide new insights into the roles of MMP8 in AdSPC differentiation and the pathogenesis of neointima formation in the context of angiographic restenosis, and therefore may aid in the development of novel therapeutic agents for the prevention of this disease.

Exosomes derived from oxidized LDL-stimulated macrophages attenuate the growth and tube formation of endothelial cells.

Oxidized low-density lipoprotein (oxLDL) has a critical role in the development of atherosclerosis. The participation of oxLDL­stimulated macrophages has been well­established in atherosclerosis, however the underlying mechanisms are unclear. Macrophage­derived exosomes are actively released and are involved in numerous physiological and pathological processes. However, the function of exosomes secreted by oxLDL­stimulated macrophages in atherosclerosis remains unknown. Exosomes from oxLDL­treated macrophages and controls were co­cultured with endothelial cells and the exosomes were taken up by endocytosis. Cell Counting Kit­8 and tube formation assay results revealed that exosomes derived from oxLDL­stimulated macrophages reduced the growth and tube formation ability of endothelial cells. Suppression of exosomal secretion by oxLDL­stimulated macrophages rescued the growth and tube formation ability of endothelial cells. Therefore, the results of the present study indicate that oxLDL­stimulated macrophages may attenuate the growth and tube formation of endothelial cells, at least in part through exosomal transfer. This may provide novel targets for the development of atherosclerosis therapeutics.

Individualized dual antiplatelet therapy based on platelet function testing in patients undergoing percutaneous coronary intervention: a meta-analysis of randomized controlled trials.

BACKGROUND: High on-treatment platelet reactivity (HPR) represents a strong risk factor for thrombotic events after PCI. We aim to evaluate the efficacy and safety of individualizing intensified dual antiplatelet therapy (DAPT) in PCI-treated patients with HPR based on platelet function testing (PFT). METHODS: Electronic databases were searched for randomized control trials that reported the clinical outcomes of using an intensified antiplatelet protocol with P2Y12 receptor inhibitor comparing with standard maintenance dose of clopidogrel on the basis of platelet function testing. Clinical endpoints were assessed. RESULTS: From 2005 to 2016, thirteen clinical studies comprising 7290 patients were included for analysis. Compared with standard antiplatelet therapy with clopidogrel, the intensified protocol based on platelet function testing was associated with a significant reduction in major adverse cardiovascular events (RR:0.55, 95% CI: 0.36-0.84, p = 0.005), cardiovascular death (RR:0.60, 95% CI: 0.38-0.96, p = 0.03), stent thrombosis (RR:0.58, 95% CI: 0.36-0.93, p = 0.02) and target vessel revascularization (RR:0.33, 95% CI: 0.14-0.76, p = 0.009). No significant difference was found in the rate of bleeding events between intensified and standard protocol. CONCLUSIONS: Compared with standard clopidogrel therapy, individualized intensified antiplatelet therapy on the basis of platelet reactivity testing reduces the incidence of cardiovascular events in patient undergoing PCI, without increasing the risk of bleeding.

Association of the HNF1A polymorphisms and serum lipid traits, the risk of coronary artery disease and ischemic stroke.

BACKGROUND: Hepatocyte nuclear factor-1α gene (HNF1A) single nucleotide polymorphisms (SNPs) have been associated with serum lipid traits in several previous genome-wide association studies. However, little is known about such associations in the Chinese populations. The present study aimed to determine the association of the HNF1A rs1169288, rs2259820, rs2464196 and rs2650000 SNPs and serum lipid traits, the risk of coronary artery disease (CAD) and ischemic stroke (IS). METHODS: The genotypes of the four SNPs in 562 CAD and 521 IS patients, as well as 594 healthy controls, were detected using the Snapshot technology. RESULTS: The genotype and allele distribution of the four SNPs was not different between controls and CAD or IS patients (p > 0.05 for all). rs1169288, rs2259820 and rs2464196 SNPs were significantly associated with serum lipid levels in both controls and CAD patients (p < 0.004-0.009). rs2259820 and rs2464196 SNPs were significantly associated with a lower risk of CAD [odds ratio (OR) = 0.64, 95% confidence interval (CI) = 0.44-0.91, p = 0.015 and OR =0.62, 95% CI = 0.43-0.89, p = 0.010, respectively]. Significant linkage disequilibrium was noted among the four SNPs (r2  > 0.5, D' > 0.8). The haplotype of rs1169288A-rs2259820C-rs2464196G-rs2650000A was associated with an increased risk of CAD (OR =1.95, 95% CI: 1.13-3.37, p = 0.015). Interactions of SNP-SNP (rs1169288-rs2464196-rs2650000) and haplotype-environment on the risk of CAD (A-C-G-A-smoking) or IS (A-C-G-A-sex and A-T-A-C-alcohol consumption) were also observed among these SNPs. CONCLUSIONS: These findings suggest that the HNF1A polymorphisms may be the genetic risk factors for CAD and IS.

Polymorphisms in the GCKR are associated with serum lipid traits, the risk of coronary artery disease and ischemic stroke.

The present study was to determine the association of two single nucleotide polymorphisms (SNPs) in the glucokinase regulator gene (GCKR) and serum lipid levels, and the risk of coronary artery disease (CAD) and ischemic stroke (IS). Genotypes of the GCKR rs1260326 and rs8179206 in 1736 unrelated subjects (CAD, 584; IS, 555; and healthy controls; 597) were determined by the Snapshot technology platform. The genotypic and allelic frequencies of rs1260326 and rs8179206 were not different among the three groups (P > 0.05). The subjects with rs1260326TT genotype had higher serum low-density lipoprotein cholesterol (LDL-C) levels in controls, and higher triglyceride (TG) levels in CAD patients than the subjects with CC and CT genotypes after adjustment for age, sex, body mass index, blood pressure, alcohol consumption, and cigarette smoking (P < 0.05). The rs1260326TT genotype was also associated with decreased risk of IS in females (OR = 0.37, 95% CI: 0.18-0.76, P = 0.007). The present study shows that the GCKR rs1260326TT genotype is associated with high LDL-C in controls, high TG levels in CAD patients, and a decreased risk of IS in females.

Association of polymorphisms in the MAFB gene and the risk of coronary artery disease and ischemic stroke: a case-control study.

BACKGROUND: The v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog B gene (MAFB) has been associated with serum lipid levels in the Eurpean population, but little is known about such association in the Chinese population or in atherosclerosis-related patients. Therefore, the purpose of the present study was to assess the association of the single nucleotide polymorphisms (SNPs) in the MAFB and serum lipid levels and the risk of coronary artery disease (CAD) and ischemic stroke (IS) in the Chinese population. METHODS: A total of 1,065 unrelated patients (CAD, 525 and IS, 540) and 539 healthy controls were recruited in this study. Genotypes of the MAFB rs2902940 and rs6102059 SNPs were determined by the Snapshot technology platform. RESULTS: The rs2902940AA genotype was associated with an increased risk of CAD (adjusted OR = 1.63, 95% CI = 1.07-2.48, P = 0.023) and IS (adjusted OR = 1.69, 95% CI = 1.09-2.61, P = 0.017). The rs2902940GA/AA genotypes were also associated with an increased risk of CAD (adjusted OR = 1.56, 95% CI = 1.04-2.32, P = 0.030 for GA/AA vs. GG) and IS (adjusted OR = 1.72, 95% CI = 1.14-2.60, P = 0.010 for GA/AA vs. GG). Significant interactions were observed only in those with higher body mass index (BMI), hypertension and diabetes (P < 0.05). The subjects with rs2902940GA/AA genotypes in controls had lower serum ApoAI levels than the subjects with GG genotype (P = 0.024). CONCLUSIONS: The rs2902940A allele carriers in the MAFB conferred a decreased serum ApoAI level in controls and an increased risk of CAD and IS. The rs2902940GA/AA genotypes interacted with higher BMI, hypertension and diabetes to contribute the risk of CAD and IS.

Reactive oxygen species in vascular formation and development.

Reactive oxygen species (ROS) are derived from the metabolism of oxygen and are traditionally viewed as toxic byproducts that cause damage to biomolecules. It is now becoming widely acknowledged that ROS are key modulators in a variety of biological processes and pathological states. ROS mediate key signaling transduction pathways by reversible oxidation of certain signaling components and are involved in the signaling of growth factors, G-protein-coupled receptors, Notch, and Wnt and its downstream cascades including MAPK, JAK-STAT, NF-κB, and PI3K/AKT. Vascular formation and development is one of the most important events during embryogenesis and is vital for postnasal tissue repair. In this paper, we will discuss how ROS regulate different steps in vascular development, including smooth muscle cell differentiation, angiogenesis, endothelial progenitor cells recruitment, and vascular cell migration.

Angiotensin II promotes differentiation of mouse embryonic stem cells to smooth muscle cells through PI3-kinase signaling pathway and NF-κB.

Embryonic stem cells (ES cells), the pluripotent derivatives of the inner cell mass from blastocysts, have the capacity for unlimited growth, self-renewal and differentiation toward all types of somatic cells. Angiotensin II (Ang II), the most important effector peptide of the renin-angiotensin system, is also an angiogenesis factor. However, the potential impact of Ang II on ES cell differentiation is still unknown. In the present study, we have successfully induced the differentiation of ES cells into smooth muscle cells (SMCs) on collagen IV. Interestingly, incubation of ES cells with Ang II further promoted SMC differentiation from ES cells, which was abolished by prior treatment with Ang II type 1 (AT1) receptor antagonist losartan, but not Ang II type 2 (AT2) receptor antagonist PD123319. Moreover, we found that, in parallel with SMC specific-marker induction, the expression levels of phosphoAkt and NF-Kappa B (NF-κB) p50 were up-regulated by Ang II. Importantly, addition of phosphoinositide-3 kinase (PI3K) inhibitor LY294002 led to a marked inhibition of Ang II induced SMC specific markers, phosphoAkt and NF-κB p50 expression. Furthermore, NF-κB inhibitor BAY11-7082 can inhibit Ang II induced expression of SMC specific markers. Thus, we demonstrate for the first time that Ang II plays a promotive role in the stage of ES cell differentiation to SMCs through AT1 receptor. We further confirmed that PI3K/Akt signaling pathway and NF-κB play key roles in this process.

Inhibition of glioma cell lysosome exocytosis inhibits glioma invasion.

Cancer cells invade by secreting enzymes that degrade the extracellular matrix and these are sequestered in lysosomal vesicles. In this study, the effects of the selective lysosome lysing drug GPN and the lysosome exocytosis inhibitor vacuolin-1 on lysosome exocytosis were studied to determine their effect on glioma cell migration and invasion. Both GPN and vacuolin-1 evidently inhibited migration and invasion in transwell experiments and scratch experiments. There are more lysosomes located on the cell membrane of glioma cells than of astrocytes. GPN decreased the lysosome number on the cell membrane. We found that rab27A was expressed in glioma cells, and colocalized with cathepsin D in lysosome. RNAi-Rab27A inhibited lysosome cathepsin D exocytosis and glioma cell invasion in an in vitro assay. Inhibition of cathepsin D inhibited glioma cell migration. The data suggest that the inhibition of lysosome exocytosis from glioma cells plays an important modulatory role in their migration and invasion.

An updated view on stem cell differentiation into smooth muscle cells.

Stem cells possess the ability of self-renewal and give rise to specific cell types. The differentiation of stem cells involves environmental factors, transduction of extra and intra-cellular signals, regulation of gene expression by transcriptional factors, microRNAs and chromosome structural modifiers. Vascular SMCs play a profound role in blood vessel physiology and participate in a number of cardiovascular diseases such as atherosclerosis, hypertension and restenosis. In addition, SMCs could be a crucial cell component for vascular tissue engineering. In this review, we aim to update the recent progress on the mechanisms of SMC differentiation from stem cells, which involve reactive oxygen species, epigenetic modifiers, transcription factors and microRNAs coordinately regulated during stem cell differentiation. We will also discuss the potential application of stem cell therapy for patients with cardiovascular diseases.

Sphingobium chlorophenolicum dichlorohydroquinone dioxygenase (PcpA) is alkaline resistant and thermally stable.

Dichlorohydroquinone dioxygenase (PcpA) is the ring-cleavage enzyme in the PCP biodegradation pathway in Sphingobium chlorophenolicum strain ATCC 39723. PcpA dehalogenates and oxidizes 2,6-dichlorohydroquinone to form 2-chloromaleylacetate, which is subsequently converted to succinyl coenzyme A and acetyl coenzyme A via 3-oxoadipate. Previous studies have shown that PcpA is highly substrate-specific and only uses 2,6-dichlorohydroquinone as its substrate. In the current study, we overexpressed and purified recombinant PcpA and showed that PcpA was highly alkaline resistant and thermally stable. PcpA exhibited two activity peaks at pH 7.0 and 10.0, respectively. The apparent k(cat) and K(m) were measured as 0.19 ± 0.01 s(-1) and 0.24 ± 0.08 mM, respectively at pH 7.0, and 0.17 ± 0.01 s(-1) and 0.77 ± 0.29 mM, respectively at pH 10.0. Electron paramagnetic resonance studies showed rapid oxidation of Fe(II) to Fe(III) in PcpA and the formation of a stable radical intermediate during the enzyme catalysis. The stable radical was predicted to be an epoxide type dichloro radical with the unpaired electron density localized on C3.

Associations of the apolipoprotein A-I gene polymorphism and serum lipid levels in the Guangxi Hei Yi Zhuang and Han populations.

Hei Yi Zhuang is an isolated subgroup of the Zhuang minority in China. Little is known about the effects of the genetic variants on serum lipid profiles in this population. The present study was undertaken to estimate the effects of the apolipoprotein (apo) A-I gene polymorphism adjacent to the initiate transcription site (-75 bp G/A) on the serum lipid levels in the Hei Yi Zhuang and Han populations. A total of 474 subjects of Hei Yi Zhuang and 564 subjects of Han Chinese were surveyed by a stratified randomized cluster sampling. Serum lipid levels were measured, and apoA-I gene polymorphism determined by polymerase chain reaction and restriction fragment length polymorphism. The frequencies of G and A alleles were 70.25 and 29.75% in Hei Yi Zhuang, and 65.96 and 34.04% in Han (P<0.05), respectively. The genotypic frequencies in Han were significantly different between males and females, subjects with normal TG (< or =1.70 mmol/l) and those with high TG (>1.70 mmol/l), or subjects with normal apoA-I (> or =1.20 g/l) and those with abnormal apoA-I (<1.20 g/l; P<0.05-0.01), respectively. The levels of LDL-C and apoA-I in Hei Yi Zhuang were higher in GG genotype than in AA or GA genotype (P<0.05 for each), but the levels of TG was lower in AA genotype than in GA genotype (P<0.05). There were also significant differences in serum TG levels among the three genotypes in Hei Yi Zhuang (P<0.05). The levels of HDL-C in Han were higher in GG genotype than in AA genotype (P<0.05), but the levels of TG in Han were lower in GG genotype than in GA genotype (P<0.05). The levels of apoA-I in Hei Yi Zhuang and the levels of HDL-C and apoB in Han were significantly correlated with genotype (P<0.05 for all). Hypertriglyceridemia was negatively associated with genotype in Hei Yi Zhuang (P<0.01). There were significant differences in the apoA-I -75 bp G/A between the Hei Yi Zhuang and Han populations. An association of the apoAI -75 bp G/A and serum TG, LDL-C and apoA-I levels in Hei Yi Zhuang and serum TG, HDL-C and apoB levels in Han was also observed in this study.