bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 182: Increased Adipose-Derived Mesenchymal Stem Cells Counts and Pro-B-Type Natriuretic Peptide in Patients With Critical Limb Ischemia
Authors: Farres Houssam , Sutton Caroline , Zubair Abba , Dortch John D , Hakaim Albert 
Published: July 2021

Mesenchymal stem cells (MSCs) have been shown to improve regeneration of injured tissues in vivo. Several in vitro studies and animal models have demonstrated improvement in MSCs paracrine effects under hypoxic conditions. Moreover, several studies suggested that the pro B-type natriuretic peptide (pro-BNP) could be involved in the stimulation of postischemic vascular regeneration. The purpose of this study was to investigate the effect of critical limb ischemia, in a human model, on in-situ adipose derived mesenchymal stem cells (ADMSCs) and to determine whether serum levels of N-terminal pro-BNP correlate with ADMSCs counts and associated paracrine effects.
Lipoaspirate samples of ≥ 10mL were collected from ischemic limbs (ischemic group) and compared to control (without ischemia). MSCs were characterized by frequency, viability, differentiation potential, cytokines expression, and cell surface markers. Serum NT pro-BNP was measured as well.
MSCs counts were 9-to-10-fold higher in patients with ischemic limbs (mean 7952 MSC/mL ± 542) than controls (mean 790 MSC/mL ± 65). Pro-BNP levels (1878-4757 pg/mL) were approximately 8-to-26-fold higher than in age- and sex-matched controls. Furthermore, there were positive correlations between pro-BNP levels and MSCs counts in the ischemic group.
In conclusion, patients with critical limb ischemia (CLI) have higher levels of pro-BNP and MSCs counts than controls. Increased levels of pro-BNP and MSCs counts can be considered humoral and cellular surrogates of ischemia and hypoxia in patients with CLI. This supports recent studies that suggest that the increase production of peripheral BNP may be a stem cells-mediated response to stimulate angiogenesis in the ischemic skeletal muscles.
Abstract 208: Improved Vasodilatory Function in Ins2Akita Type 1 Diabetic Mice with Daily Intake of Oral L-Arginine in Combination with Salsalate
Authors: Krishnan Manikcam , Janardhanan Preethi , Gaudette Colleen , Reddick Robert , Van Haperen Rien , Natarajan Mohan , Mohan Sumathy 
Published: July 2021

Endothelial dysfunction due to deficient nitric oxide (NO) generation cause progressive vascular complications in diabetes. Our earlier findings revealed that Inhibitor kappa B kinase beta (IKK-beta) -an upstream regulator of an inflammatory mediator, nuclear factor kappa-B (NF-kB), competitively inhibits endothelial nitric oxide synthase (eNOS), the chief source of NO in blood vessels. Therefore, we investigated the influence of an inhibitor of IKK beta, salsalate in augmenting eNOS activity. The co-operative effect of L-arginine supplementation (substrate of eNOS) with salsalate intake in enhancing eNOS activity has been evaluated.
Both in vitro cell cultures and diabetic/transgenic animal models were used. Human aortic endothelial cells incubated with 25 mM glucose with or without L-arginine (2mM), the cofactor sepiapterin (100uM) and salsalate(50uM) were examined for NO production. Combined L-arginine and salsalate treatment enhanced NO production, phospho eNOS expression and eNOS-dimer vs monomer ratio. For in vivo assays, diabetic Ins2Akita mice were fed with L-arginine and salsalate for 15 weeks. Aortae of these mice exhibited increased phospho eNOS expression and increased eNOS dimer/monomer ratio. Arterial ring assays showed improved acetylcholine mediated vasodialation. Transgenic-Akita mice that overexpress human eNOS in endothelial cells (Tie-2eNOS-Ins2 Akita) generated in-house showed improved vasodialation.
In conclusion, enhancing eNOS activity in diabetic mice either by genetic modification as seen in Tie-2 eNOS-Akita mice or by nutritional approach (supplementation of L-arginine with simultaneous inhibition of IKK beta) restores normal vasodialatory function.
Abstract 209: Dimethylarginine Dimethylaminohydrolase 1 and Insulin Resistance
Authors: Piper Sophie E , Leiper James M 
Published: July 2021

Type 2 diabetes is a prevalent metabolic condition and is the result of an impaired response to insulin. Insulin resistance and type 2 diabetes are clearly associated with obesity and the secondary cardiovascular complications of this condition are serious and life threatening.
Asymemetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthases and increased levels are seen in multiple pathologies. Increased plasma levels of ADMA have been associated with patients with type 2 diabetes, insulin resistance and obesity, although a causal link between ADMA and diabetes has not been established. Dimethylarginine dimethylaminohydrolase (DDAH) is the enzyme that catalyses the metabolism of ADMA. There are two isoforms of the enzyme which are both involved in the control of ADMA and NO.
The interplay of insulin with NO release is well established but the initial causes for the onset of insulin resistance are not well defined. Elevated levels of ADMA are linked to insulin resistance and transgenic mice that over-express ddah1 show increased insulin sensitivity. Of note is that metformin, an insulin sensitising drug that is widely used in the treatment of insulin resistance, reduces plasma glucose and ADMA concentrations.
In order to elucidate the physiological role of DDAH1 in glucose homeostasis we investigated the glucose handling in a ddah1 global knockout model.
Intra-peritoneal glucose tolerance tests in ddah1 global knockout mice demonstrate insulin resistance. Baseline plasma glucose levels were 25% higher in ddah1 knockouts and peak levels were 53% higher in ddah1 knockouts. The kinetics of plasma glucose accumulation and clearance in ddah1 knockout mice suggests dysfunction in both the liver and skeletal muscle. On a normal chow diet, hepatocyte specific ddah1 knockout mice and skeletal muscle specific ddah1 knockout mice show no insulin resistance. On a high fat diet however the hepatocyte specific ddah1 knockout mice show significant insulin resistance and lower metabolic rate than their fat fed wild-type counterparts.
These studies demonstrate for the first time a causal link between ADMA accumulation and insulin resistance. Furthermore these data establish DDAH1 activity is a significant regulator of insulin resistance.
Abstract 328: Capillary Formation and Autologous Regulation of Androgen Receptor Expression in Endothelial Progenitor Cells by DHT: Potential Implications for EPC-Mediated Cardiovascular Repair in Men
Authors: Plutino Yuliya , Barchiesi Federica , Simigdala Nikiana , Imthurn Bruno , Dubey Raghvendra 
Published: July 2021

Therapeutic use of Endothelial Progenitor Cells (EPCs) is known to repair and protect against cardiovascular damage. Since androgens are associated with cardiovascular protection in men, we investigated the mechanism(s) by which androgens (dihydrotestosterone; DHT) can modulate androgen receptor (AR) dependent EPC activity.
Tube/capillary formation and androgen receptor expression by cultured EPCs was assessed using 2D-cultures/co-cultures, western blotting and RT-PCR.
Treatment with DHT (100nM) induced capillary/tube formation by EPCs (≈179±3%; p<.05 vs control) and these effects were attenuated by AR antagonist flutamide and AR siRNA. DHT (10-100nM) up-regulated AR protein expression and this effect was abrogated by AR antagonist flutamide (1μM), AR silencing siRNA and cycloheximide (protein synthesis inhibitor). Compared to AR protein, DHT did not induce AR mRNA expression and DHT-induced AR expression was not blocked by the transcription inhibitor actinomycin-D (10ng/ml). Treatment with proteasome inhibitor MG132 (100nM) mimicked the effects of DHT on AR protein expression, moreover, when combined with DHT, the stimulatory effects on AR expression were additive. To ascertain the role of protein stabilization in mediating AR up-regulation in EPCs, the effects of MG132 and DHT on Raf-1, which is known to undergo proteasomal degradation, were assessed. Treatment with MG132, but not DHT, increased Raf-1 expression in EPCs. Moreover, the stimulatory effects of DHT on capillary formation were enhanced in presence of MG132. These findings suggest that DHT up-regulates AR expression and function in EPCs via protein stabilization, however, participation of other pathways cannot be ruled out.
In EPCs, DHT induces capillary formation via AR and regulates AR expression in an autologous fashion. Since, androgens induce endothelial growth, and most patients receiving EPCs for cardiovascular repair are older, the low endogenous levels of androgens would decrease the potential of stem cell mediated tissue repair. More importantly, pretreatment of patients or priming of EPCs with androgens/DHT, as well as co-administration of DHT with EPCs may potentiate ARs and EPC mediate cardiovascular tissue repair in men.
Abstract 35: Plasma Fibronectin is a Vital Supportive Factor in Hemostasis and a Unique Self-Limiting Regulator in Thrombosis
Authors: Wang Yiming , Reheman Adili , Spring Christopher , Kalantari Jalil , Marshall Alexandra , Wolberg Alisa , Gross Peter , Weitz Jeffrey , Rand Margaret , Freedman John , Mosher Deane , Ni Heyu 
Published: July 2021

The role of plasma fibronectin (pFn) in thrombosis/hemostasis is controversial. We previously demonstrated that pFn supports thrombosis in pFn-/- mice. Interestingly, depletion of pFn in fibrinogen (Fg)/VWF-/- mice resulted in enhanced thrombus formation, revealing a functional switch of pFn in the absence of Fg/VWF. However, the mechanism controlling this switch is unknown. Furthermore, the hemostatic function of pFn is unclear.
To address these questions, we established Fg/pFn-/- and VWF/pFn-/- mice in addition to triple deficient mice (Fg/VWF/pFn-/-, TKO). TKO mice had significantly higher mortality (23.1% vs. 9.1%) and longer tail bleeding time than their pFn+ Fg/VWF-/- littermates. Autopsy revealed severe subcutaneous or abdominal bleeding. pFn depletion in Fg-/- mice also increased mortality from 5.5% to 25.6% and prolonged bleeding times; the latter effect was reversed with pFn infusion. Using intravital microscopy, we found that pFn deposition at the site of injury preceded significant platelet accumulation, suggesting that pFn is an efficient and rapid hemostatic factor. Based on thromboelastography, fibrin clots from pFn+ mice were significantly stronger than those from pFn-/- mice. Consistent with this, inferior vena cava occlusion was significantly delayed in pFn-/- mice. Under confocal microscopy, fluorescently-labeled pFn was actively recruited into the fibrin network in mouse and human plasma. Under electron microscopy, physiological levels of pFn doubled the diameter of fibrin fibers, suggesting that pFn contributes to lateral aggregation of fibrin protofibrils. Interestingly, pFn enhances platelet aggregation when linked with fibrin and inhibits aggregation when fibrin is absent. pFn therefore gradually switches from supporting hemostasis to inhibiting thrombosis and vessel occlusion following the fibrin gradient that decreases farther from the injured endothelium.
Our data established pFn as an important supportive factor in hemostasis and a unique self-limiting regulator of thrombosis, suggesting the therapeutic potential of pFn transfusion in controlling bleeding complications, particularly for those receiving antithrombotic therapy for heart attack and stroke.
Abstract 362: Genomewide Assessment of Posttranscriptional Events Orchestrated by Quaking that Determine Monocyte Fate
Authors: van der Veer Eric P 
Published: July 2021

The post-transcriptional events that enable monocytes to home to sites of vascular injury, and subsequently differentiate into macrophages within atherosclerotic lesions are poorly understood. We discovered that the mRNA and protein levels of the RNA-binding protein Quaking (QKI) are augmented in CD14+ myeloid cells extracted from advanced human atherosclerotic plaques (4.2-fold upregulated vs. early lesions; p<0.01). This prompted us to investigate how the RNA-binding properties of QKI could influence monocyte fate.
Our approach was to examine, at a genome-wide level, how altering the expression levels of QKI could impact pre-mRNA splicing, expression, and localization upon differentiation of human monocytes into Mf. For this, we employed both array-based gene expression analyses as well as next-generation sequencing techniques (RNA-seq) of THP-1 monocytic cells as well as CD14+ monocytes derived from the peripheral blood of a unique, QKI haploinsufficient subject (with sibling control). Despite low expression levels of QKI in monocytes, the abrogation of QKI in these cells perturbed cellular adhesion and the ensuing establishment of the cytoskeletal architecture. Interestingly, our investigation of post-transcriptional events that are associated with the conversion of the monocyte to a macrophage, uncovered: 1) 536 alternative splicing events (p<0.05) that are directly mediated by binding of QKI proximal to the splice site (QBS)(Fig. 1A); and 2) 1214 differentially expressed genes (minimally +/- 1.5-fold; p<0.05) that indicate that QKI modulates monocyte activation and differentiation by regulating inflammation, cell growth and survival, RNA editing and lipid metabolism via activation of the LXR/RXR pathway (Fig. 1B).
Collectively, our data illustrate the post-transcriptional events that drive monocyte to macrophage differentiation, and identify the RNA-binding protein QKI as an orchestrator of this inflammatory response.
Abstract 460: Characterization of Glycated Albumin Isolated From Poorly Controlled Diabetic Patients and Its Role in Macrophage Cholesterol Efflux
Authors: Machado-Lima Adriana , Oliveira Erika R , Iborra Rodrigo T , Castilho Gabriela , Nakandakare Edna R , Corrêa-Giannella Maria Lucia C , Traldi Pietro , Porcu Simona , Roverso Marco , Lapolla Annunziata , Passarelli Marisa 
Published: July 2021

Advanced glycation end products (AGE) are elevated in diabetes mellitus (DM) and predict the development of atherosclerosis. In vitro produced AGE-albumin induces oxidative stress that is linked to the reduction in ABCA-1 levels and cholesterol efflux mediated by apo A-I and HDL-subfractions, leading to macrophage cholesterol accumulation.
We characterized the glycation level/profile of human serum albumin (HSA) isolated by fast protein liquid chromatography from poorly controlled type 1 (DM1) and type 2 (DM2) diabetes mellitus patients (HbA1c > 8%) in comparison to control (C) individuals, and how these AGE-albumin can interfere in macrophage lipid accumulation.
The glycation level of HSA from C, DM1 and DM2 was analyzed by MALDI mass spectrometry and was similar between DM1 and DM2-HSA. An increased mean mass was observed in DM1-HSA (68,544 ± 192 Da; n=6) and DM2-HSA (68,547 ± 132 Da; n=6) compared to C-HSA (67,846 ± 301 Da; n=6), reflecting the condensation of at least 8 and 5 units of glucose, respectively. The tryptic digestion of C-HSA generated a number of peptide species higher than those originated from DM1 and DM2-HSA.
Macrophages isolated from peritoneal wild-type mice were treated for 18 h with C, DM1 or DM2-HSA in order to measure the 14C-cholesterol efflux and the mRNA expression of NOX-4 (NADPHoxidase4), ABCA-1 (Abca1) and ABCG-1 (Abcg1). Data were compared by one-way ANOVA and Dunnet′s post test.
In comparison to cells treated with C-HSA the expression of NADPHoxidase4 (p<0.05; n=3) mRNA was increased after cell treatment with DM1 (3.2x) and DM2-HSA (0.7x), confirming oxidative stress. Abcg1 mRNA was reduced by DM2-HSA (26%; p<0.05; n=3); Abca1 mRNA was unchanged but ABCA-1 protein content was greatly reduced (82 and 25%, respectively in DM1 and DM2-HAS; p<0.05; n=12). The % of apo A-I mediated cholesterol efflux was impaired in DM1 (1.3 ± 0.3) and DM2-HSA-treated cells (2.4 ± 0.5) as compared to C-HSA (4.4 ± 0.5; n= 5; p<0.05).
The level of advanced glycation that takes place in vivo was similar between DM1 and DM2-HSA and induced macrophage oxidative stress and impairment in cholesterol efflux that may contribute to atherogenesis in DM.

Funding:
FAPESP, Brazil (2012/19112-0)
Abstract 466: Stigmasterol Accumulation in ABCG8 Knockout Mice Does Not Account for Xenosterol Toxicity
Authors: Patel Shailendra B 
Published: July 2021

Xenosterol accumulation mice deficient in sterolin function leads to significant toxicity, with infertility, decreased body fat accumulation, macrothrombocytopenia, cardiac fibrosis and premature death1, 2. The predominant xenosterols are phytosterols derived from the diet and are a mixture of sitosterol (typically 70%), campesterol (~20%) and stigmasterol (~5-10%). Although sitosterol has been shown to have some biological effect in tissue culture, only stigmasterol has been shown to have a potent biological effect, by activating the transcriptional factor, Lxr3. To delineate whether all of the toxic biological effects were mediated by stigmasterol accumulation, we designed a diet that was supplemented with highly enriched stigmasterol (>80% purity) and fed this to Abcg8 knockout mice. Stigmasterol accumulation in the plasma and tissues was comparable to the levels observed in mice fed a mixed phytosterol-enriched diet that had been shown to result in toxicity.
Over a 12-week period, both male and female Abcg8 knockout mice gained normal amounts of weight, body fat, showed no disturbances in tail-cuff measured blood pressure, and plasma analyses showed no abnormalities of platelet counts or volumes, blood glucose, plasma cholesterol, despite accumulation of stigmasterol in the plasma and tissues. Fertility testing showed no abnormalities. Gene expression analyses of livers did not show any consistent patterns, although Lxr target genes were not up-regulated.
These data do not support the concept that stigmasterol accumulation, at levels of 5-10mg/dL in plasma, account for the xenosterol-mediated toxicity observed.
1. McDaniel, A.L., H.M. Alger, J.K. Sawyer, K.L. Kelley, N.D. Kock, J.M. Brown, R.E. Temel, and L.L. Rudel, Phytosterol feeding causes toxicity in ABCG5/G8 knockout mice. Am J Pathol, 2013. 182(4): p. 1131-8.
2. Solca, C., G.S. Tint, and S.B. Patel, Dietary xenosterols lead to infertility and loss of abdominal adipose tissue in sterolin-deficient mice. J Lipid Res, 2013. 54(2): p. 397-409.
3. Yang, C., L. Yu, W. Li, F. Xu, J.C. Cohen, and H.H. Hobbs, Disruption of cholesterol homeostasis by plant sterols. J. Clin. Invest., 2004. 114(6): p. 813-22.
Abstract 484: Uptake of 18F-Fluorodeoxyglucose Detected by Positron Emission Tomography in the Abdominal Aortic Aneurysm is Correlated With Endoleaks and Predicts the Adverse Outcome of Aneurysm After Endovascular Aortic Repair
Authors: Courtois Audrey , Namur Gauthier , El Hachemi Mounia , Cremmers Etienne , Nusgens Betty , Hustinx Roland , Allaire Eric , Defraigne Jean-Olivier , Colige Alain , Sakalihasan Natzi 
Published: July 2021

Endovascular aortic repair (EVAR) has been applied to abdominal aortic aneurysm (AAA) to decrease and prevent morbidity and mortality due to open surgery. However, this therapeutic approach may lead to complications such as occurrence of endoleaks which may result in rupture of the aneurysm. Decisions for complementary treatment after EVAR to prevent aneurysm rupture are based on endoleak characterization and aortic diameter evolution. The presence of endoleak or enlarging diameter is however not always predictive of rupture. Recent reports support the view that 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) provides unique information on cellular metabolic activity thought to drive aneurysm expansion and rupture.
We evaluated if FDG/PET could predict the outcome of aneurysm repaired by endoprosthesis. A cohort of 56 AAA patients (55 male; mean age of 74.6 years), treated by EVAR, underwent one or several PET/CT before and/or after surgery with a total number of 108 examinations. The quantification analysis of FDG uptake was not correlated to the AAA diameter but was strongly correlated with the presence of endoleak (55% of endoleak in patients with significant FDG uptake (PET+) versus 25% in PET0). Moreover, the PET+ AAA presented symptoms such as increasing diameter of aneurysmal sac (64% in PET+ versus 33% in PET0). On the other hand, two PET+ patients underwent conversion for open surgery for rapid growth and rupture with leaking. These outcomes did not occur among the PET0 patients. Increased circulating levels of fibrinolytic factors (D-dimers, thrombin/anti-thrombin and plasmin/anti-plasmin complexes) and inflammatory cytokines IL6 and IL8, were found in patients with endoleak while the collagenase MMP1 was largely decreased. Finally, two other MMPs, MMP12 and MMP13 were correlated with the uptake level of FDG.
Altogether, these results suggest that the presence of endoleak is associated with an activation of the fibrinolytic pathway and PET positivity induces factors involved in the extracellular matrix remodeling leading to instability of the wall and its rupture. This study suggests that PET/CT might predict the negative outcome of EVAR and represent a beneficial tool for patient management.
Abstract 54: PSI Domain of ß3 Integrin Has Endogenous Thiol Isomerase Function and is a Novel Antithrombotic Therapeutic Target
Authors: Reddy Emily C , Zhu Guangheng , Chen Pingguo , Reheman Adili , Lei Xi , Li June , Xu Xiaohong , Freedman John , Ni Heyu 
Published: July 2021

Integrin αIIbβ3 plays a critical role in platelet aggregation and adhesion, key events in hemostasis and thrombosis. Integrin activation involves complex signalling events that lead to conformational changes exposing ligand-binding sites; however, mechanisms underlying integrin activation remain poorly understood. The β subunit contains a PSI domain that is highly conserved across integrins and species, though its function is unknown. Integrin β subunits are cysteine-rich and endogenous thiol isomerase activity in integrin β3 has been reported. The PSI domain contains two CXXC sequences, the active site motif of protein disulfide isomerase (PDI).
Based on this observation and the location of this domain at the knee region of the integrin, we hypothesized that integrin PSI domain has endogenous thiol isomerase function, which plays a key regulatory role in integrin conformation and function. Targeting the PSI domain may have therapeutic potential.

Using reduced, denatured RNase, a recombinant murine integrin β3 PSI domain demonstrated endogenous PDI-like activity. This PDI-like activity was dose-dependently inhibited by the PDI inhibitor, bacitracin. Mutation of either CXXC motif within the integrin β3 PSI domain reduced PDI-like activity, while removal of both CXXC motifs completely abolished this activity. We developed unique mouse anti-mouse/anti-human β3 PSI domain monoclonal antibodies (anti-PSI mAbs) that inhibited the PDI-like activity of both the murine recombinant integrin β3 PSI domain and purified human platelet β3 integrin, in a dose-dependent manner. Interestingly, the anti-PSI mAbs blocked fibrinogen to human platelet β3 integrin in a cell free system. Furthermore, anti-PSI mAbs inhibited murine and human platelet aggregation
in vitro
and
ex vivo
and inhibited murine thrombus formation
in vivo
without significantly changing bleeding time or platelet count.

In conclusion, we identified that the PSI domain has PDI function, is a fundamental regulator of platelet β3 integrin activation, and is a potential novel target for anti-thrombotic therapies. Since PSI domain is conserved in all integrin β subunits, our discovery may have broad implications for the role of integrins in cell biology of many human diseases.