Primary Aortic Endothelial Cells Research Articles

Co-activation of Mas and pGCA receptors suppresses Endothelin-1-induced endothelial dysfunction via nitric oxide/cGMP system

BackgroundThe aortic endothelium is crucial in preserving vascular tone through endothelium-derived vasodilators and vasoconstrictors. Dysfunction in the endothelium is an early indicator of cardiovascular diseases. Our study explores the therapeutic potential of a dual-acting peptide (DAP) to co-activate Mas and pGCA receptors and restore the balance between vasodilators and vasoconstrictors on endothelial dysfunction in DOCA-salt-induced hypertensive rats. MethodsDOCA-salt was administered to male wistar rats to induce hypertension, and various parameters, including blood pressure (BP), water intake and body weight were monitored. DAP, Ang1–7, BNP, and losartan were administered to hypertensive rats for three weeks. Histological analysis and isometric tension studies were carried out to assess endothelial function. In addition to this, we used primary aortic endothelial cells for detailed mechanistic investigations. ResultsDOCA-salt administration significantly elevated systolic, diastolic, mean arterial BP, and water intake whereas, downregulated the gene expression of Mas and pGCA receptors. However, DAP co-administration attenuated BP increase, upregulated the gene expression of Mas and pGCA receptors, normalized serum and urinary parameters, and effectively reduced fibrosis, inflammation, and vascular calcification. Notably, DAP outperformed the standard drug, Losartan. Our findings indicate that DAP restores aortic function by balancing the NO and ET1-induced pathways. ConclusionCo-activating Mas and pGCA receptors with DAP mitigates vascular damage and enhances endothelial function, emphasizing its potential to maintain a delicate balance between vasodilatory NO and vasoconstrictor ET1 in endothelial dysfunction.

Content determination of seven active components of Eucommiae Cortex in aortic vascular endothelial cells of spontaneously hypertensive rats by UPLC-MS/MS

In the present study, the contents of seven active components [genipinic acid(GA), protocatechuic acid(PCA), neochlorogenic acid(NCA), chlorogenic acid(CA), cryptochlorogenic acid(CCA),(+)-pinoresinol di-O-β-D-glucopyranosid(PDG), and(+)-pinoresinol 4'-O-β-D-glucopyranoside(PG)] of Eucommiae Cortex in aortic vascular endothelial cells of spontaneously hypertensive rats(SHR) were simultaneously determined by ultra-high liquid chromatography-triple quadrupole mass spectrometry(UPLC-MS/MS). The qualified SHR models were selected. The primary aortic endothelial cells(VECs) of rats were separated and cultured by ligation and adherence, followed by subculture. After successful identification, an UPLC-MS/MS method for simultaneously determining the contents of GA, PCA, NCA, CA, CCA, PDG, PG in seven components of Eucommiae Cortex in VECs was established, including specificity, linearity, matrix effect, recovery, accuracy, precision and stability. The established method had the lo-west limit of quantification of 0.97-4.95 μg·L~(-1), accuracy of 87.26%-109.6%, extraction recovery of 89.23%-105.3%, matrix effect of 85.86%-106.2%, and stability of 86.00%-112.5%. Therefore, the established accurate UPLC-MS/MS method could rapidly and simultaneously determine the contents of the seven active components of Eucommiae Cortex in VECs of SHRs, which provided a refe-rence for the study of cellular pharmacokinetics of active components of Eucommiae Cortex extract.

Integrative analysis of Iso-Seq and RNA-seq reveals dynamic changes of alternative promoter, alternative splicing and alternative polyadenylation during Angiotensin II-induced senescence in rat primary aortic endothelial cells.

In eukaryotes, alternative promoter (AP), alternative splicing (AS), and alternative polyadenylation (APA) are three crucial regulatory mechanisms that modulate message RNA (mRNA) diversity. Although AP, AS and APA are involved in diverse biological processess, whether they have dynamic changes in Angiotensin II (Ang II) induced senescence in rat primary aortic endothelial cells (RAECs), an important cellular model for studying cardiovascular disease, remains unclear. Here we integrated both PacBio single-molecule long-read isoform sequencing (Iso-Seq) and Illumina short-read RNA sequencing (RNA-seq) to analyze the changes of AP, AS and APA in Ang II-induced senescent RAECs. Iso-Seq generated 36,278 isoforms from 10,145 gene loci and 65.81% of these isoforms are novel, which were further cross-validated by public data obtained by other techonologies such as CAGE, PolyA-Seq and 3'READS. APA contributed most to novel isoforms, followed by AS and AP. Further investigation showed that AP, AS and APA could all contribute to the regulation of isoform, but AS has more dynamic changes compared to AP and APA upon Ang II stimulation. Genes undergoing AP, AS and APA in Ang II-treated cells are enriched in various pathways related to aging or senescence, suggesting that these molecular changes are involved in functional alterations during Ang II-induced senescence. Together, the present study largely improved the annotation of rat genome and revealed gene expression changes at isoform level, extending the understanding of the complexity of gene regulation in Ang II-treated RAECs, and also provided novel clues for discovering the regulatory mechanism undelying Ang II caused vascular senescence and diseases.

Circular RNA circ_0001445 alleviates the ox-LDL-induced endothelial injury in human primary aortic endothelial cells through regulating ABCG1 via acting as a sponge of miR-208b-5p

Coronary artery disease (CAD) originates from the blockage of the inner walls of the coronary arteries due to a plaque buildup. Circular RNA (circRNA) circ_0001445 has been reported to be downregulated in patients with a higher coronary atherosclerotic burden. This study is designed to explore the role and mechanism of circ_0001445 on the oxidized low-density lipoprotein (ox-LDL)-induced endothelial cell damage. Circ_0001445, microRNA-208b-5p (miR-208b-5p), and ATP-binding cassette sub-family G member 1 (ABCG1) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Inflammatory cytokines levels, cell viability, proliferation, migration were detected by Enzyme-linked immunosorbent assay (ELISA) kits, Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), and transwell assays, respectively. Protein levels were determined by western blot assay. The binding between miR-208b-5p and circ_0001445 or ABCG1 was predicted by circBank or TargetScan, and then verified by a dual-luciferase reporter, RNA Immunoprecipitation (RIP), and RNA pull-down assays. Circ_0001445 and ABCG1 were decreased, and miR-208b-5p was increased in CAD patients and ox-LDL-treated HAECs. Also, circ_0001445 overexpression could weaken ox-LDL-triggered HAEC injury by boosting proliferation, migration, and repressing inflammation andextracellular matrix (ECM). Mechanically, circ_0001445 directly targeted miR-208b-5p. Furthermore, miR-208b-5p mediated the modulation of circ_0001445 in ox-LDL-induced HAEC injury. ABCG1 acted as a direct target of miR-208b-5p, and the downregulation of miR-208b-5p relieved ox-LDL-induced HAEC damage by interacting with ABCG1. Additionally, circ_0001445 regulated ABCG1 expression by sponging miR-208b-5p. Circ_0001445 could abate ox-LDL-mediated HAEC damage by the miR-208b-5p/ABCG1 axis, providing a novel insight into the pathogenesis and treatment of CAD.

Dominant role of CACNA1D exon mutations for blood pressure regulation.

CACNA1D gene, which encodes the α1 subunit of the Cav1.3 L-type calcium channel effectively regulates intracellular Ca2+ stability. In recent years, clinical studies have shown that the CACNA1D polymorphisms were associated with hypertension. The purpose of this study was to evaluate the effects of CACNA1D exon mutation on blood pressure (BP) in Sprague-Dawley rats. The rats with CACNA1D p.D307G, CACNA1D p.V936I or CACNA1D p.R1516Q were constructed using CRISPR-Cas9 technology. SBP measurements of rats were taken for 32 weeks. Tissue morphology of rats and vasoactive substances in serum was tested. Furthermore, the effects of L-type calcium channel blocker isradipine and endothelin-1 (ET-1) inhibitor BQ-123 on BP of double mutation rats (CACNA1D p.D307G/p.R1516Q) were tested. Then we examined the effects of CACNA1D gene mutation on gene expression in human umbilical vein endothelial cells (HUVECs) and vascular smooth muscle cells (VSMCs). Elevated SBP and increased circulating ET-1 was observed in CACNA1D p.D307G mutant rats. Morphological assessments showed that the vascular, cardiac and renal remodeling could also be observed in rats with p.D307G mutant. Cav1.3 protein expression and calcineurin phosphatase activity in VSMCs of rats with CACNA1D p.D307G were increased in vitro, and the vascular ring tension test of mesenteric grade 3 arteries in CACNA1D p.D307G rats were increased in vivo. Furthermore, ET-1 expression were increased in isolated primary aortic endothelial cells in p.D307G mutant rats and transfected p.D307G mutant HUVECs. Finally, double heterozygosity rats with CACNA1D p.D307G/p.R1516Q or CACNA1D p.D307G/p.V936I further accelerated the rise of SBP compared with p.D307G mutation rats, and isradipine and BQ-123 reduced BP to the same extent in CACNA1D p.D307G/p.R1516Q rats. CACNA1D gene is key players in the regulation of blood pressure. CACNA1D mutation rat may be a new hypertension animal model.

Upregulation of Neogenin-1 by a CREB1-BAF47 Complex in Vascular Endothelial Cells is Implicated in Atherogenesis.

Atherosclerosis is generally considered a human pathology of chronic inflammation, to which endothelial dysfunction plays an important role. Here we investigated the role of neogenin 1 (Neo-1) in oxidized low-density lipoprotein (oxLDL) induced endothelial dysfunction focusing on its transcriptional regulation. We report that Neo-1 expression was upregulated by oxLDL in both immortalized vascular endothelial cells and primary aortic endothelial cells. Neo-1 knockdown attenuated whereas Neo-1 over-expression enhanced oxLDL-induced leukocyte adhesion to endothelial cells. Neo-1 regulated endothelial-leukocyte interaction by modulating nuclear factor kappa B (NF-κB) activity to alter the expression of adhesion molecules. Neo-1 blockade with a blocking antibody ameliorated atherogenesis in Apoe −/− mice fed a Western diet. Ingenuity pathway analysis combined with validation assays confirmed that cAMP response element binding protein 1 (CREB1) and Brg1-associated factor 47 (BAF47) mediated oxLDL induced Neo-1 upregulation. CREB1 interacted with BAF47 and recruited BAF47 to the proximal Neo-1 promoter leading to Neo-1 trans-activation. In conclusion, our data delineate a novel transcriptional mechanism underlying Neo-1 activation in vascular endothelial cells that might contribute to endothelial dysfunction and atherosclerosis.

Best Practices for Authentication of Cell Lines to Ensure Data Reproducibility and Integrity.

Cell line misidentification and contamination are major contributors to the reproducibility crisis in academic research. Authentication of cell lines provides assurances of the data generated; however, commercially available cells are often not subjected to rigorous identification testing. In this study, commercially available cell lines underwent testing to confirm cell identity and purity. The methods reported here outline the best practices for cell line authentication. Briefly, a commercially available primary rabbit aortic endothelial cell line was purchased for the intent of producing target proteins necessary for generating species-specific recombinant antibodies. These rabbit-specific antibodies would then be utilized for the development of in-house enzyme-linked immunosorbent assays (ELISA) to evaluate blood-based biomarkers of vascular injury after total-body irradiation. To authenticate the cell line, cell identity and purity were determined by single tandem repeat (STR) testing, flow cytometry, polymerase chain reaction (PCR), and cytochrome c oxidase subunit 1 (CO1) DNA Barcoding in-house and/or through commercial vendors. Fresh cells obtained from a New Zealand White rabbit (Charles River, Wilmington, DE) were used as a positive control. The results of STR and flow cytometry analyses indicated the cells were not contaminated with human or mouse cells, and that the cells were not of endothelial origin. PCR demonstrated that cells were also not of rabbit origin, which was further confirmed by a third-party vendor. An unopened vial of cells was submitted to another vendor for CO1 DNA Barcoding analysis, which identified the cells as being purely of bovine origin. Results revealed that despite purchase through a commercial vendor, the cell line marketed as primary rabbit aortic endothelial cells were of bovine origin. Purity analysis found cells were misidentified rather than contaminated. Further investigation to determine the cell type was not performed. The most cost-effective and efficient methodology for confirming cell line identity was found to be CO1 DNA Barcoding performed by a commercial vendor.

Hyaluronic Acid/Collagen Nanofiber Tubular Scaffolds Support Endothelial Cell Proliferation, Phenotypic Shape and Endothelialization.

In this study, we designed and synthetized artificial vascular scaffolds based on nanofibers of collagen functionalized with hyaluronic acid (HA) in order to direct the phenotypic shape, proliferation, and complete endothelization of mouse primary aortic endothelial cells (PAECs). Layered tubular HA/collagen nanofibers were prepared using electrospinning and crosslinking process. The obtained scaffold is composed of a thin inner layer and a thick outer layer that structurally mimic the layer the intima and media layers of the native blood vessels, respectively. Compared with the pure tubular collagen nanofibers, the surface of HA functionalized collagen nanofibers has higher anisotropic wettability and mechanical flexibility. HA/collagen nanofibers can significantly promote the elongation, proliferation and phenotypic shape expression of PAECs. In vitro co-culture of mouse PAECs and their corresponding smooth muscle cells (SMCs) showed that the luminal endothelialization governs the biophysical integrity of the newly formed extracellular matrix (e.g., collagen and elastin fibers) and structural remodeling of SMCs. Furthermore, in vitro hemocompatibility assays indicated that HA/collagen nanofibers have no detectable degree of hemolysis and coagulation, suggesting their promise as engineered vascular implants.

Abstract P167: Utilization Of A Novel Artery-on-a-chip For Target Discovery And Drug Testing In Experimental Vascular Medicine

The aorta-on-a-chip (AoOC) is a micro-engineered 3D in vitro model which aims to mimic the in vivo complexity of a human aorta in terms of cell-cell interaction, tissue architecture and hemodynamic conditions, i.e., the wall shear stress (WSS) force that the blood exerts on the vessel luminal surface in the direction of blood flow.The device used to generate the AoOC consists of a resealable glass chip with an intermediate semi-permeable membrane dividing the chip into two distinct chambers. This enables the flow of different fluids under varying dynamic conditions through the respective chambers. Primary aortic endothelial cells are cultivated on a thin layer of collagen on the flat-side of the membrane, whereas primary aortic smooth muscle cells are cultured on a fibronectin layer on the well-side of the same membrane. Once cells are confluent, the glass chip is assembled and sealed due to the slight pressure applied by the chip holder which is ultimately connected to a microfluidic pressure controller. The chamber containing the endothelial cells is subjected to a high flow rate of 1.2 ml/min, equivalent to 10 dynes/cm 2 , mimicking the shear stress of the aortic wall. In contrast, the smooth muscle cells are exposed to a slow flow rate of 20 μl/min, corresponding to 0.0042 dynes/cm 2 , that simulates the physiological diffusion rate between the intima and the media layer (of the aorta), ensuring an adequate supply of nutrients to the cells.The quality of the co-culture system is assessed by immunofluorescence staining using CD31 and SM22 antibody which specifically mark ECs and SMCs attached at opposite sides of the membrane. To evaluate transcriptomic changes under different flow conditions (static vs 10dyne/cm2) cells were carefully collected at opposite site of the membrane and subjected to RNA sequencing analysis.

Abstract MP14: Endothelial Cullin3 Mutation Causes Decreased Nitric Oxide (NO) Bioavailability And Vascular Dysfunction Through Protein Phosphatase 2A

Mutations in CULLIN3 gene (in-frame deletion of exon 9, termed Cul3Δ9) cause human hypertension (HT) driven by a combination of renal tubular and vascular mechanisms. To test the importance of endothelial Cul3 in vivo , we bred the conditionally activatable Cul3Δ9 mice with tamoxifen-inducible Tie2-CRE ERT2 mice. The resultant mice (E-Cul3Δ9) developed arterial stiffening (pulse wave velocity, 3.7±0.3 vs 2.7±0.1 m/s, n=5-7, p<0.05) and a trend towards elevated nighttime blood pressure (peak systolic BP, E-Cul3Δ9 136±3 vs control 128±3 mmHg, n=9-11) that were not associated with any alterations in locomotion, food/water intake or sleep/wake behaviors. No difference was seen in daytime BP. To determine whether vascular remodeling impairs baroreflex function, we performed power spectral analysis. Heart rate (HR), low frequency/high frequency ratio of HR variability, and baroreflex gain were comparable between control and E-Cul3Δ9 mice, suggesting no change in cardiac sympathetic nerve activity. However, low frequency amplitude of arterial pressure variability (16±4 vs 7±2 mmHg 2 , n=5-9, p<0.05) at night was markedly augmented in E-Cul3Δ9 mice, suggesting increased sympathetic activity in vascular tone regulation. Consistently, E-Cul3Δ9 mice exhibited impaired endothelial-dependent relaxation in carotid artery (max ACh relaxation: 69% vs 84%, n=5-7, p<0.05) and cerebral resistance basilar artery (41% vs 77%, n=4-6, p<0.05). However, no dilatory impairment in mesenteric resistance artery and no difference in smooth muscle function were observed, suggesting that the effects of Cul3Δ9 are arterial bed specific. Expression of Cul3Δ9 in primary mouse aortic endothelial cells markedly decreased wild type Cul3 protein, phosphorylated eNOS and NO production. Protein phosphatase (PP) 2A, a known Cul3 substrate, dephosphorylates eNOS. Therefore, we determined whether impaired eNOS activity was attributable to PP2A. Cul3Δ9-induced impairment of eNOS activity was rescued by a selective PP2A inhibitor okadaic acid (4nM), but not by a PP1 inhibitor tautomycetin (4nM). Thus, CUL3 mutations in the endothelium may contribute to human HT in part through decreased endothelial NO bioavailability, arterial stiffening and secondary sympathoexcitation.

Oxidized GAPDH transfers S-glutathionylation to a nuclear protein Sirtuin-1 leading to apoptosis

AimsS-glutathionylation is a reversible oxidative modification of protein cysteines that plays a critical role in redox signaling. Glutaredoxin-1 (Glrx), a glutathione-specific thioltransferase, removes protein S-glutathionylation. Glrx, though a cytosolic protein, can activate a nuclear protein Sirtuin-1 (SirT1) by removing its S-glutathionylation. Glrx ablation causes metabolic abnormalities and promotes controlled cell death and fibrosis in mice. Glyceraldehyde 3-phosphate dehydrogenase (GAPDH), a key enzyme of glycolysis, is sensitive to oxidative modifications and involved in apoptotic signaling via the SirT1/p53 pathway in the nucleus. We aimed to elucidate the extent to which S-glutathionylation of GAPDH and glutaredoxin-1 contribute to GAPDH/SirT1/p53 apoptosis pathway. ResultsExposure of HEK 293T cells to hydrogen peroxide (H2O2) caused rapid S-glutathionylation and nuclear translocation of GAPDH. Nuclear GAPDH peaked 10–15 min after the addition of H2O2. Overexpression of Glrx or redox dead mutant GAPDH inhibited S-glutathionylation and nuclear translocation. Nuclear GAPDH formed a protein complex with SirT1 and exchanged S-glutathionylation to SirT1 and inhibited its deacetylase activity. Inactivated SirT1 remained stably bound to acetylated-p53 and initiated apoptotic signaling resulting in cleavage of caspase-3. We observed similar effects in human primary aortic endothelial cells suggesting the GAPDH/SirT1/p53 pathway as a common apoptotic mechanism. ConclusionsAbundant GAPDH with its highly reactive-cysteine thiolate may function as a cytoplasmic rheostat to sense oxidative stress. S-glutathionylation of GAPDH may relay the signal to the nucleus where GAPDH trans-glutathionylates nuclear proteins such as SirT1 to initiate apoptosis. Glrx reverses GAPDH S-glutathionylation and prevents its nuclear translocation and cytoplasmic-nuclear redox signaling leading to apoptosis. Our data suggest that trans-glutathionylation is a critical step in apoptotic signaling and a potential mechanism that cytosolic Glrx controls nuclear transcription factors.

Non-HLA Antibodies and Epitope Mismatches in Kidney Transplant Recipients With Histological Antibody-Mediated Rejection

BackgroundCorrelation between antibody-mediated rejection (ABMR) and circulating HLA donor-specific antibodies (HLA-DSA) is strong but imperfect in kidney transplant (KT) recipients, raising the possibility of undetected HLA-DSA or non-HLA antibodies contributing to ABMR. Detailed evaluation of the degree of HLA matching together with the identification of non-HLA antibodies in KT may help to decipher the antibody involved.MethodsWe retrospectively assessed patients with transplant biopsies scored following Banff’15 classification. Pre- and post-transplant serum samples were checked for HLA and non-HLA antibodies [MICA-Ab, angiotensin-II type-1-receptor (AT1R)-Ab, endothelin-1 type-A-receptor (ETAR)-Ab and crossmatches with primary aortic endothelial cells (EC-XM)]. We also analyzed HLA epitope mismatches (HLA-EM) between donors and recipients to explore their role in ABMR histology (ABMRh) with and without HLA-DSA.ResultsOne-hundred eighteen patients with normal histology (n = 19), ABMRh (n = 52) or IFTA (n = 47) were studied. ABMRh patients were HLA-DSApos (n = 38, 73%) or HLA-DSAneg (n = 14, 27%). Pre-transplant HLA-DSA and AT1R-Ab were more frequent in ABMRh compared with IFTA and normal histology cases (p = 0.006 and 0.003), without differences in other non-HLA antibodies. Only three ABMRhDSAneg cases showed non-HLA antibodies. ABMRhDSAneg and ABMRhDSApos cases showed similar biopsy changes and graft-survival. Both total class II and DRB1 HLA-EM were associated with ABMRhDSApos but not with ABMRhDSAneg. Multivariate analysis showed that pre-transplant HLA-DSA (OR: 3.69 [1.31–10.37], p = 0.013) and AT1R-Ab (OR: 5.47 [1.78–16.76], p = 0.003) were independent predictors of ABMRhDSApos.ConclusionsIn conclusion, pre-transplant AT1R-Ab is frequently found in ABMRhDSApos patients. However, AT1R-Ab, MICA-Ab, ETAR-Ab or EC-XM+ are rarely found among ABMRhDSAneg patients. Pre-transplant AT1R-Ab may act synergistically with preformed or de novo HLA-DSA to produce ABMRhDSApos but not ABMRhDSAneg. HLA epitope mismatch associates with ABMRhDSApos compared with ABMRhDSAneg, suggesting factors other than HLA are responsible for the damage.

FC 128NON-HLA ANTIBODIES AND EPLET MISMATCHES IN KIDNEY TRANSPLANT RECIPIENTS WITH A HISTOLOGICAL PICTURE OF ANTIBODY-MEDIATED REJECTION WITH AND WITHOUT HLA DONOR-SPECIFIC ANTIBODIES

Abstract Background and Aims Correlation between antibody-mediated rejection (ABMR) and HLA donor-specific antibodies (DSA) is strong but imperfect in kidney transplant (KT) recipients, raising the possibility of other detrimental antibodies contributing to ABMR. The role of non-HLA antibodies on outcomes is not well known. Method We retrospectively assessed KT biopsies scored according to Banff’15 classification. Pre- and post-KT serum samples were checked for HLA and non-HLA antibodies (MICA-Ab, angiotensin II type 1 receptor (AT1R)-Ab, endothelin-1 type A receptor (ETAR)-Ab and crossmatches with primary aortic endothelial cells (EC-XM)). We also analyzed HLA epitope mismatches between donors and recipients. Results One-hundred eighteen patients with normal (n=19), ABMR histology (n=52) or IFTA (n=47) in their biopsy were studied. Graft survival was worse in ABMR patients (p=0.003). Pre-KT HLA-DSA were more frequent in ABMR cases (p=0.006). At biopsy, 73% ABMR patients had HLA-DSA (p<0.001). Pre-KT AT1R-Ab were more frequent in ABMR compared with IFTA and normal cases (p=0.003), without differences in other non-HLA antibodies. Fourteen patients with histological ABMR (27%) had no detectable HLA-DSA post-KT and only 3 had non-HLA Ab. However, these ABMR-DSA- cases showed similar biopsy changes and graft survival compared with ABMR-DSA+. Pre- or post-KT non-HLA antibodies other than AT1R-Ab were detected similarly in ABMR and in normal or IFTA cases. Both total class II and DRB1 epitope mismatches were associated with postransplant DSA and ABMR-DSA+. Multivariate analysis showed that both pre-KT HLA-DSA and AT1R-Ab (DSA: OR: 3.39 [1.20-9.59], p=0.021; AT1R-Ab: OR: 5.31 [1.75-16.10], p=0.003) were strong independent predictors of postransplant ABMR-DSA+ (Table 1). Conclusion Despite highly prevalent HLA-DSA before and after transplantation in KT with histological ABMR, 27% of cases did not show circulating HLA-DSA. Pre-KT AT1R-Ab associated with ABMR-DSA+, but not MICA-Ab, ETAR-Ab or EC-XM+. Any of them associated significantly with ABMR-DSA-. Epitope mismatch predicted both postransplant DRB-DSA and ABMR-DSA+. Detection of pre-KT HLA-DSA and/or AT1R-Ab, together with HLA epitope mismatch assessment, are valuable tools for better DSA and ABMR prediction in KT patients.

A biomimetic shock model on the effect of endothelial aging on vascular barrier properties.

Aging is characterized by a decline in cellular function, which has an adverse effect on the biologic response to injury. Both aging and trauma/hemorrhagic shock (T/HS) increase oxidative stress which impairs the vascular endothelium (EC) and glycocalyx (EG). The additive effect of aging on EC and EG damage following T/HS are unknown. This was studied in an in vitro model. Confluent endothelial cell monolayers from primary aortic endothelial cells from 10-week-old mice ("young" cells) or primary aortic cells from 65-week-old mice ("aged" cells) were established in microfluidic devices (MFDs) and perfused at constant shear conditions overnight. Mouse endothelial cell monolayers were then exposed to hypoxia/reoxygenation alone and/or epinephrine or norepinephrine. Endothelial glycocalyx degradation was indexed as well as subsequent endothelial injury/activation. Aged endothelial cells showed increase glycocalyx shedding and subsequent loss of glycocalyx thickness. This lead to a more pronounced level of EC injury/activation compared with young endothelial cells. Although exposure to biomimetic shock conditions exacerbated both endothelial glycocalyx shedding and endothelial injury in both aged and young endothelial cells, the effect was significantly more pronounced in aged cells. Advanced age is associated with worse outcomes in severely injured trauma patients. Our study demonstrates that there is increased EG shedding and a diminished EG layer in aged compared to "young" endothelial cell layers. Biomimetic shock conditions lead to an even greater impairment of the endothelial glycocalyx in aged versus young endothelial cell monolayers. It appears that these effects are a consequence of aging related oxidative stress at both baseline and shock conditions. This exacerbates shock-induced endotheliopathy and may contribute to untoward effects on patient outcomes in this population.

Human Tissue Kallikrein 1 Is Downregulated in Elderly Human Prostates and Possesses Potential In Vitro Antioxidative and Antifibrotic Effects in Rodent Prostates.

Objective The aim of the present study was to investigate the protective effects and mechanisms of KLK1 on aging-related prostate alterations and search clues about the application of KLK1 to the treatment of human BPH. Methods Thirty-six rats including 26 male wild-type SD rats and 10 transgenic rats were fed to 3- or 18-month-old and divided into three groups: young WTR (yWTR) as the control (n = 16), aged WTR (aWTR) (n = 10), and aged TGR (aTGR) (n = 10). The prostates of the three groups of rats (10 rats per group) were harvested to evaluate the levels of KLK1 expression, oxidative stress, fibrosis, and involved signaling pathways, such as NO/cGMP, COX-2/PTGIS/cAMP, and TGF-β1/RhoA/ROCK1, via quantitative PCR, Western blot, histological examinations, and ELISA. Moreover, the remaining 6 yWTRs were sacrificed to obtain primary prostate fibroblast and aortic endothelial cells, and a coculture system was built with the cells for the verification of above signaling pathways in vitro. And the direct effects of bradykinin on prostate cells were detected by MTT experiment. Prostate specimens of 47 patients (age from 48 to 92 years) undergoing BPH surgery were collected after approval. Histological examinations and KLK1 IHC were preformed to analyze the relationship between KLK1 expression and age and prostate fibrosis. Results The human KLK1 gene only existed and was expressed in aTGR. The prostate of young rats expressed more KLK1 than the aged and the expression of KLK1 in prostate decreased with age in humans (r = −0.347, P = 0.018). Compared to the aWTR group, the yWTR and aTGR groups showed milder fibrosis, less oxidative stress, upregulated NO/cGMP, and COX-2/PTGIS/cAMP signaling pathways and inhibited TGF-β1/RhoA/ROCK1 signaling pathway. In the coculture system, KLK1 suppressed TGF-β1-mediated fibroblast-to-myofibroblast transdifferentiation via cleaving LMWK to produce the BK which upregulate eNOS expression and NO production in endothelial cells. BK not only slightly stimulated the proliferation ability of prostatic stromal cells but also upregulated iNOS and inhibited TGF-β1 expression in them. Conclusion KLK1 protects prostate from oxidative stress and fibrosis via amplified NO/cGMP signal in aged rats. The decrease of KLK1 expression with aging is laying the groundwork for the application of KLK1 to the treatment of human BPH. The current experimental data showed that the side effects of KLK1 on the prostate cell were not obvious.

Life-Long Hyperbilirubinemia Exposure and Bilirubin Priming Prevent In Vitro Metabolic Damage

Background: Unconjugated bilirubin (UCB) is more than the final product of heme catabolism. Mildly elevated systemic bilirubin concentrations, such as in Gilbert syndrome (GS), protect against various oxidative stress-mediated and metabolic diseases, including cardiovascular disease, type 2 diabetes mellitus, metabolic syndrome, cancer, and age-related disease. The Gunn rat is an animal model of hereditary hyperbilirubinemia widely used in assessing the effect of high serum bilirubin concentration in various organs. The present work aims to understand if life-long hyperbilirubinemia and bilirubin-priming might contribute to protection against atherosclerosis and diabetic nephropathy (DN) at the cellular level. Methods: Primary aortic endothelial cells and podocytes obtained from hyperbilirubinemic homozygous jj and normobilirubinemic heterozygous Nj Gunn rats were exposed to Palmitic Acid (PA) and Angiotensin II (Ang II), respectively, and the effects on cell viability and the activation of damage-related metabolic pathways evaluated. Results were validated on immortalized H5V and HK2 cells exposed to damage after UCB pretreatment. Results: In both primary cell models, cells obtained from jj Gunn rats showed as significantly higher than Nj Gunn rats at any dose of the toxic agent. Reduction in CHOP expression and IL-6 release was observed in jj primary aortic endothelial cells exposed to PA compared to Nj cells. The same occurred on H5V pretreated with Unconjugated bilirubin. Upon Ang II treatment, primary podocytes from jj Gunn rats showed lower DNA fragmentation, cleaved caspase-3, and cleaved PARP induction than primary podocytes from Nj Gunn rats. In HK2 cells, the induction by Ang II of HIF-1α and LOXl2 was significantly reduced by UCB pretreatment. Conclusion: Our data suggest that in models of atherosclerosis and DN life–long hyperbilirubinemia exposure or bilirubin-priming significantly contribute to decrease the injury by enhancing thecellular defensive response,

Melatonin Promotes Heterotopic Ossification Through Regulation of Endothelial-Mesenchymal Transition in Injured Achilles Tendons in Rats.

Although heterotopic ossification (HO) has been reported to be a common complication of the posttraumatic healing process, the underlying mechanism remains unknown. Endothelial-mesenchymal transition (EndMT) is known to play a role in HO, and our recent study observed that neuroendocrine signals can promote HO by modulating EndMT. Melatonin, a neuroendocrine hormone secreted mainly by the pineal gland, has been documented to perform its function in the skeletal system. This study aimed at describing the expression of melatonin during the formation of HO in rat models of Achilles tendon injury and to further investigate its role in regulating EndMT in HO. Histological staining revealed the expression of melatonin throughout the formation of heterotopic bone in injured Achilles tendons, and the serum melatonin levels were increased after the initial injury. Double immunofluorescence showed that the MT2 melatonin receptor was notably expressed at the sites of injury. Micro-CT showed the enhancement of heterotopic bone volume and calcified areas in rats treated with melatonin. Additionally, our data showed that melatonin induced EndMT in primary rat aortic endothelial cells (RAOECs), which acquired traits including migratory function, invasive function and EndMT and MSC marker gene and protein expression. Furthermore, our data exhibited that melatonin promoted the osteogenic differentiation of RAOECs undergoing EndMT in vitro. Importantly, inhibition of the melatonin-MT2 pathway by using the MT2 selective inhibitor 4-P-PDOT inhibited melatonin-induced EndMT and osteogenesis both in vivo and in vitro. In conclusion, these findings demonstrated that melatonin promoted HO through the regulation of EndMT in injured Achilles tendons in rats, and these findings might provide additional directions for the management of HO.

Exosomal LINC00174 derived from vascular endothelial cells attenuates myocardial I/R injury via p53-mediated autophagy and apoptosis

In this study, we aim to investigate the regulation of specific long non-coding RNAs (lncRNAs) on the progression of ischemia/reperfusion (I/R) injury. We identified and characterized the exosomes derived from mouse primary aortic endothelial cells. Subsequently, we found that these exosomes expressed typical exosomal markers and high levels of LINC00174, which significantly ameliorated I/R-induced myocardial damage and suppressed the apoptosis, vacuolation, and autophagy of myocardial cells. Mechanistic approaches revealed that LINC00174 directly interacted with SRSF1 to suppress the expression of p53, thus restraining the transcription of myocardin and repressing the activation of the Akt/AMPK pathway that was crucial for autophagy initiation in I/R-induced myocardial damage. Moreover, this molecular mechanism was verified by in vivo study. In summary, exosomal LINC00174 generated from vascular endothelial cells repressed p53-mediated autophagy and apoptosis to mitigate I/R-induced myocardial damage, suggesting that targeting LINC00174 may be a novel strategy to treat I/R-induced myocardial infarction.

Knockdown of circular RNA hsa_circ_0003204 inhibits oxidative stress and apoptosis through the miR-330-5p/Nod2 axis to ameliorate endothelial cell injury induced by low-density lipoprotein.

IntroductionAtherosclerosis (AS) is the leading cause of cardiovascular disease. Circular RNA hsa_circ_0003204 (hsa_circ_0003204) was elevated in oxidized low-density lipoprotein (ox-LDL)-induced human umbilical vein endothelial cells. However, the role and molecular mechanism of hsa_circ_0003204 in the AS process have not been studied.Material and methodsHuman primary aortic endothelial cells (HAECs) were treated with low-density lipoprotein (ox-LDL) to establish the AS model. The viability of ox-LDL-induced HAECs was assessed by counting kit-8 (CCK8) assay. Reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD) levels in ox-LDL-induced HAECs supernatant were evaluated with the relevant kits. The apoptosis of ox-LDL-induced HAECs was determined via flow cytometry assay. The expression of hsa_circ_0003204, miR-330-5p, and nucleotide-binding oligomerization domain 2 (Nod2) was analyzed through quantitative real-time polymerase chain reaction (qRT-PCR). The relationship between hsa_circ_0003204 or Nod2 and miR-330-5p was verified by dual-luciferase reporter assay. Protein level of Nod2 was detected using western blot analysis.ResultsHsa_circ_0003204 and Nod2 were upregulated while miR-330-5p was decreased in ox-LDL-induced HAECs. Hsa_circ_0003204 depletion restrained the oxidative stress and apoptosis of ox-LDL-induced HAECs. Notably, hsa_circ_0003204 regulated Nod2 expression via sponging miR-330-5p in HAECs. Moreover, miR-330-5p inhibition restored the constraint of the oxidative stress and apoptosis of ox-LDL-induced HAECs caused by hsa_circ_0003204 silencing. Additionally, miR-330-5p targeted Nod2 and Nod2 enhancement abolished the repressive effects of miR-330-5p overexpression on the oxidative stress and apoptosis of ox-LDL-induced HAECs.ConclusionsHsa_circ_0003204 exhaustion mitigated endothelial cell injury through suppressing the oxidative stress and apoptosis in ox-LDL-induced HAECs via the miR-330-5p/Nod2 axis.

Abstract P086: Endothelial Cullin3 Mutation Causes Vascular Dysfunction, Arterial Stiffening, And Hypertension

Mutations in CULLIN3 gene (causing in-frame deletion of exon 9, termed Cul3Δ9) cause human hypertension (HT), which is driven by a combination of renal tubular and vascular mechanisms. We have previously shown that disruption of Cullin3 (CUL3) in vascular smooth muscle impairs nitric oxide (NO) signaling and vasodilation through decreased cGMP bioavailability, strongly supporting a role of vascular CUL3 in blood pressure (BP) regulation. To test the importance of endothelial Cul3 in vivo , we bred the conditionally activatable Cul3Δ9 mice with tamoxifen-inducible Tie2-CRE ERT2 mice. Four weeks after tamoxifen, the resultant mice (E-Cul3Δ9) developed nocturnal HT (Night time peak systolic BP, E-Cul3Δ9: 135±3 vs Control: 124±3 mmHg) and arterial stiffening (pulse wave velocity, 3.7±0.3 vs 2.7±0.1 m/s). No difference was seen in daytime BP. To determine whether vascular remodeling impairs baroreflex function, we performed power spectral analysis. Heart rate (HR), low frequency/high frequency ratio of HR variability, and baroreflex gain were comparable between control and E-Cul3Δ9 mice, suggesting there was no change in cardiac sympathetic nerve activity. However, low frequency amplitude of arterial pressure variability (16±4 vs 7±2 mmHg 2 ) at night was markedly augmented in E-Cul3Δ9 mice, suggesting increased sympathetic activity in vascular tone regulation. Consistently, E-Cul3Δ9 mice exhibited impaired endothelial-dependent relaxation in carotid artery (Max ACh relaxation: 69% vs 84%) and cerebral resistance basilar artery (41% vs 77%). No difference in smooth muscle function was observed. Expression of Cul3Δ9 in primary mouse aortic endothelial cells markedly decreased wild type Cul3 protein, phosphorylated eNOS, and NO production. Because protein phosphatase 2A (PP2A) is a known Cul3 substrate which dephosphorylates eNOS, we determined whether impaired eNOS activity was attributable to PP2A. Cul3Δ9-induced impairment of eNOS activity was rescued by a selective PP2A inhibitor Okadaic Acid (4 nM), but not by a Protein Phosphatase 1 inhibitor Tautomycetin (4 nM). Thus, CUL3 mutations in the endothelium contribute to human HT in part through decreased NO bioavailability, endothelial dysfunction and secondary sympathoexcitation.