Kallistatin limits abdominal aortic aneurysm by attenuating generation of reactive oxygen species and apoptosis

Diagnostic and therapeutic value of human serpin family proteins

SERPIN (serine proteinase inhibitors) is an acronym for the superfamily of structurally similar proteins found in animals, plants, bacteria, viruses, and archaea. Over 1500 SERPINs are known in nature, while only 37 SERPINs are found in humans, which participate in inflammation, coagulation, angiogenesis, cell viability, and other pathophysiological processes. Both qualitative or quantitative deficiencies or overexpression and/or abnormal accumulation of SERPIN can lead to diseases commonly referred to as "serpinopathies". Hence, strategies involving SERPIN supplementation, elimination, or correction are utilized and/or under consideration. In this review, we discuss relationships between certain SERPINs and diseases as well as putative strategies for the clinical explorations of SERPINs.

Inhibition of smooth muscle cell death by Angiotensin 1-7 protects against abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) represents a debilitating vascular disease characterized by aortic dilatation and wall rupture if it remains untreated. We aimed to determine the effects of Ang 1-7 in a murine model of AAA and to investigate the molecular mechanisms involved. Eight- to 10-week-old apolipoprotein E-deficient mice (ApoEKO) were infused with Ang II (1.44 mg/kg/day, s.c.) and treated with Ang 1-7 (0.576 mg/kg/day, i.p.). Echocardiographic and histological analyses showed abdominal aortic dilatation and extracellular matrix remodeling in Ang II-infused mice. Treatment with Ang 1-7 led to suppression of Ang II-induced aortic dilatation in the abdominal aorta. The immunofluorescence imaging exhibited reduced smooth muscle cell (SMC) density in the abdominal aorta. The abdominal aortic SMCs from ApoEKO mice exhibited markedly increased apoptosis in response to Ang II. Ang 1-7 attenuated cell death, as evident by increased SMC density in the aorta and reduced annexin V/propidium iodide-positive cells in flow cytometric analysis. Gene expression analysis for contractile and synthetic phenotypes of abdominal SMCs showed preservation of contractile phenotype by Ang 1-7 treatment. Molecular analyses identified increased mitochondrial fission, elevated cellular and mitochondrial reactive oxygen species (ROS) levels, and apoptosis-associated proteins, including cytochrome c, in Ang II-treated aortic SMCs. Ang 1-7 mitigated Ang II-induced mitochondrial fission, ROS generation, and levels of pro-apoptotic proteins, resulting in decreased cell death of aortic SMCs. These results highlight a critical vasculo-protective role of Ang 1-7 in a degenerative aortic disease; increased Ang 1-7 activity may provide a promising therapeutic strategy against the progression of AAA.

Effect of Hydralazine on Angiotensin II-Induced Abdominal Aortic Aneurysm in Apolipoprotein E-Deficient Mice

The rupture of an abdominal aortic aneurysm (AAA) causes about 200,000 deaths worldwide each year. However, there are currently no effective drug therapies to prevent AAA formation or, when present, to decrease progression and rupture, highlighting an urgent need for more research in this field. Increased vascular inflammation and enhanced apoptosis of vascular smooth muscle cells (VSMCs) are implicated in AAA formation. Here, we investigated whether hydralazine, which has anti-inflammatory and anti-apoptotic properties, inhibited AAA formation and pathological hallmarks. In cultured VSMCs, hydralazine (100 μM) inhibited the increase in inflammatory gene expression and apoptosis induced by acrolein and hydrogen peroxide, two oxidants that may play a role in AAA pathogenesis. The anti-apoptotic effect of hydralazine was associated with a decrease in caspase 8 gene expression. In a mouse model of AAA induced by subcutaneous angiotensin II infusion (1 µg/kg body weight/min) for 28 days in apolipoprotein E-deficient mice, hydralazine treatment (24 mg/kg/day) significantly decreased AAA incidence from 80% to 20% and suprarenal aortic diameter by 32% from 2.26 mm to 1.53 mm. Hydralazine treatment also significantly increased the survival rate from 60% to 100%. In conclusion, hydralazine inhibited AAA formation and rupture in a mouse model, which was associated with its anti-inflammatory and anti-apoptotic properties.

Degree of expression of inflammatory proteins in the amniotic cavity, but not prior obstetric history, is associated with the risk severity for spontaneous preterm birth after rescue cerclage for cervical insufficiency

PROBLEM

To examine whether the severity of spontaneous preterm birth (SPTB) risk after rescue cerclage for acute cervical insufficiency (CI) is linked to the degree of inflammatory response in the amniotic fluid (AF) based on the concentrations of various inflammatory proteins and prior obstetric history.

METHOD OF STUDY

We conducted a retrospective cohort study of 65 singleton pregnant women (17-25 weeks) who underwent rescue cerclage following the diagnosis of acute CI and were subjected to amniocentesis. EN-RAGE, IL-6, IL-8, and IP-10 as inflammatory mediators and kallistatin, MMP-2/8, and uPA as extracellular matrix remodeling-related molecules were assayed in the AF using ELISA. The level of each inflammatory mediator was divided into quartiles.

RESULTS

Intra-amniotic inflammation (IAI; AF IL-6 level ≥2.6 ng/mL) was independently associated with SPTB after cerclage placement. The odds of SPTB at < 32 weeks, even after adjusting for confounders, increased significantly with each increasing quartile of baseline AF levels for each inflammatory mediator (p for trend < .05). Kaplan-Meier survival curves showed that the cerclage-to-delivery intervals were significantly shorter as the quartiles of AF EN-RAGE and MMP-8 increased (log-rank test, p < .01 each). Neither previous term birth nor prior PTB was associated with SPTB risk or cerclage-to-delivery interval after rescue cerclage. Multiparous women who experience CI after term birth showed significantly elevated levels of MMP-8 and reduced kallistatin levels in the AF.

CONCLUSION

In patients with CI, SPTB risk (especially risk severity) after rescue cerclage is associated with the degree of the inflammatory response in AF as well as the presence of IAI but not with prior obstetric history.

MiR-125b and SATB1-AS1 might be shear stress-mediated therapeutic targets

The aim of the study was to explore the potential molecular mechanism associated with shear stress on abdominal aortic aneurysm (AAA) progression. This study performed RNA sequencing on AAA patients (SQ), AAA patients after endovascular aneurysm repair (EVAR, SH), and normal controls (NC). Furthermore, we identified the differentially expressed microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNA (cirRNAs) and constructed competing endogenous RNA (ceRNA) networks. Finally, 164 differentially expressed miRNAs, 179 co-differentially expressed lncRNAs, and 440 co-differentially expressed circRNAs among the three groups were obtained. The differentially expressed miRNAs mainly enriched in 325 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. Target genes associated with co-differentially expressed genes among the group of SH, SQ, and NC mainly enriched in 66 KEGG pathways. LncRNA-miRNA-mRNA interactions, including 15 lncRNAs, 63 miRNAs and 57 mRNAs, was constructed. CircRNA-miRNA-mRNA ceRNA network included 79 circRNAs, 21 miRNAs, and 49 mRNAs. Among them, KLRC2 and CSTF1, targeted by miR-125b, participated in cell-mediated immunity regulation. MiR-320-related circRNAs and SATB1-AS1 serving as the sponge of miRNAs, such as has-circ-0129245, has-circ-0138746, and has-circ-0139786, were hub genes in ceRNA network. In conclusion, AAA patients might be benefit from EVAR based on various pathways and some molecules, such as miR-125b and SATB1-AS1, related with shear stress.

Moxonidine Increases Uptake of Oxidised Low-Density Lipoprotein in Cultured Vascular Smooth Muscle Cells and Inhibits Atherosclerosis in Apolipoprotein E-Deficient Mice

This study aimed to investigate the effect of the sympatholytic drug moxonidine on atherosclerosis. The effects of moxonidine on oxidised low-density lipoprotein (LDL) uptake, inflammatory gene expression and cellular migration were investigated in vitro in cultured vascular smooth muscle cells (VSMCs). The effect of moxonidine on atherosclerosis was measured by examining aortic arch Sudan IV staining and quantifying the intima-to-media ratio of the left common carotid artery in apolipoprotein E-deficient (ApoE^-/-) mice infused with angiotensin II. The levels of circulating lipid hydroperoxides in mouse plasma were measured by ferrous oxidation-xylenol orange assay. Moxonidine administration increased oxidised LDL uptake by VSMCs via activation of α2 adrenoceptors. Moxonidine increased the expression of LDL receptors and the lipid efflux transporter ABCG1. Moxonidine inhibited mRNA expression of inflammatory genes and increased VSMC migration. Moxonidine administration to ApoE^-/- mice (18 mg/kg/day) decreased atherosclerosis formation in the aortic arch and left common carotid artery, associated with increased plasma lipid hydroperoxide levels. In conclusion, moxonidine inhibited atherosclerosis in ApoE^-/- mice, which was accompanied by an increase in oxidised LDL uptake by VSMCs, VSMC migration, ABCG1 expression in VSMCs and lipid hydroperoxide levels in the plasma.

Differential Serum Proteomic Signatures between Acute Aortic Dissection and Acute Myocardial Infarction

Acute aortic dissection (AAD) and acute myocardial infarction (AMI) are both severe cardiovascular diseases that may cause sudden death. However, whether serum proteins are differentially expressed between AAD and AMI remains unclear. Here, we aimed to explore serum protein profiles between AAD and AMI patients. A total of 75 serum samples were collected, including AAD patients without AMI (n = 25), AMI patients without AAD (n = 25), and normal subjects (n = 25). Protein identities and expression levels were assessed by LC-MS/MS analysis and a label-free quantitation method, respectively. After depletion of albumin and IgG, a total of 117 proteins with differential expression (fold change ≥2 or ≤−2.0, p < 0.05) were identified, of which 60 were upregulated and 57 were downregulated in AAD sera as compared to AMI sera. Bioinformatic analysis revealed that the differentially expressed serum proteins were mainly derived from exosomes and the extracellular space, and their molecular functions and biological processes were primarily involved in the activity of transporters and complements and the immune response. In addition, the serum level of Cadherin-5, an identified protein with significant regulation in AAD, was further evaluated by ELISA and the results showed that Cadherin-5 in AAD sera was higher that in AMI and healthy sera. Collectively, these findings reveal the differential serum protein profiles between AAD and AMI, which may reflect the divergent pathophysiological progression between the two cardiovascular diseases.

N1-Methyladenosine (m1A) Regulation Associated With the Pathogenesis of Abdominal Aortic Aneurysm Through YTHDF3 Modulating Macrophage Polarization

Objectives

This study aimed to identify key AAA-related m1A RNA methylation regulators and their association with immune infiltration in AAA. Furthermore, we aimed to explore the mechanism that m1A regulators modulate the functions of certain immune cells as well as the downstream target genes, participating in the progression of AAA.

Methods

Based on the gene expression profiles of the GSE47472 and GSE98278 datasets, differential expression analysis focusing on m1A regulators was performed on the combined dataset to identify differentially expressed m1A regulatory genes (DEMRGs). Additionally, CIBERSORT tool was utilized in the analysis of the immune infiltration landscape and its correlation with DEMRGs. Moreover, we validated the expression levels of DEMRGs in human AAA tissues by real-time quantitative PCR (RT-qPCR). Immunofluorescence (IF) staining was also applied in the validation of cellular localization of YTHDF3 in AAA tissues. Furthermore, we established LPS/IFN-γ induced M1 macrophages and ythdf3 knockdown macrophages in vitro, to explore the relationship between YTHDF3 and macrophage polarization. At last, RNA immunoprecipitation-sequencing (RIP-Seq) combined with PPI network analysis was used to predict the target genes of YTHDF3 in AAA progression.

Results

Eight DEMRGs were identified in our study, including YTHDC1, YTHDF1-3, RRP8, TRMT61A as up-regulated genes and FTO, ALKBH1 as down-regulated genes. The immune infiltration analysis showed these DEMRGs were positively correlated with activated mast cells, plasma cells and M1 macrophages in AAA. RT-qPCR analysis also verified the up-regulated expression levels of YTHDC1, YTHDF1, and YTHDF3 in human AAA tissues. Besides, IF staining result in AAA adventitia indicated the localization of YTHDF3 in macrophages. Moreover, our in-vitro experiments found that the knockdown of ythdf3 in M0 macrophages inhibits macrophage M1 polarization but promotes macrophage M2 polarization. Eventually, 30 key AAA-related target genes of YTHDF3 were predicted, including CD44, mTOR, ITGB1, STAT3, etc.

Conclusion

Our study reveals that m1A regulation is significantly associated with the pathogenesis of human AAA. The m1A “reader,” YTHDF3, may participate in the modulating of macrophage polarization that promotes aortic inflammation, and influence AAA progression by regulating the expression of its target genes.