bluuebunny/crossref_metadata_2025_split huggingface dataset:
HIF‐2α mediates hypoxia‐dependent upregulation of Serpin‐B3, a marker of early liver carcinogenesis (144.7)
Authors: Cannito Stefania , Turato Cristian , Paternostro Claudia , Biasiolo Alessandra , Pontisso Patrizia , Parola Maurizio 
Published: June 2021

SERPINB3 (S‐B3), a cysteine‐proteases inhibitor up‐regulated in cirrhosis, dysplastic nodules and hepatocellular carcinoma (HCC), can trigger epithelial‐to‐mesenchymal transition (EMT) and increased invasiveness in hepatic cancer cells. In this study we have investigated whether hypoxia, through involvement of hypoxia inducible factors (HIFs), may affect S‐B3 expression by employing morphological, molecular and cell biology techniques in liver‐derived cancer cell lines, normal murine liver and liver specimens from HCC patients.Exposure of HepG2 and HUH7 cells to hypoxia resulted in S‐B3 up‐regulation in terms of mRNA, protein synthesis and release in the extracellular medium. The use of specific siRNAs and of ChIP assay revealed that S‐B3 up‐regulation is mediated by HIF‐2α (not HIF‐1α) binding to S‐B3 promoter and that this is a redox‐dependent event. The correlation between hypoxia, HIF‐2α and S‐B3 expression was supported by immunohistochemistry analysis on normal murine liver and on tumor specimens from HCV‐cirrhotic patients carrying HCC. Hypoxia, through HIF‐2α‐dependent and redox sensitive mechanisms, is the first ever described stimulus of pathophysiological relevance able to up‐regulate expression of S‐B3, a protein proposed as marker of early liver carcinogenesis.
Leukocyte cell‐derived chemotaxin 2 (LECT2) is a potential serum biomarker specific for βcatenin mutation in hepatocellular carcinoma (144.8)
Authors: Okabe Hirohisa , Delgado Evan , Min Lee , Singh Sucha , Tsung Allan , Monga Satdarshan 
Published: June 2021

Objective: Molecular characteristic of tumor is currently crucial information in terms of the sensitivity to therapeutic agent and the prediction of clinical course. The aim of this study is to identify a biomarker specific for β‐Catenin gene (CTNNB1) mutation seen in 20‐30% of patients with hepatocellular carcinoma (HCC).Methods: We looked for secreted factors specific for CTNNB1 mutation using microarray analysis previously published, and validated it using stable transfectants with β‐Catenin wild‐type (Hep3BWT) and mutated form (Hep3BS33Y). Serum level of the biomarker and genetic background of primary tumor were examined in mice with liver cancer caused by diethylnitrosamine (DEN) + phenobarbital diet, which is known to induce HCC via CTNNB1 mutation.Results: Leukocyte cell‐derived chemotaxin 2 (LECT2) is downregulated in β‐Catenin KO livers. Hep3BS33Y secreted more LECT2 and showed higher promoter activity of LECT2 compared to Hep3BWT. Mice with β‐Catenin mutated (S33Y) liver cancer showed significantly higher serum LECT2 level than control or non‐tumor bearing mice. They showed high glutamine synthetase and lect2 gene expression.Conclusion: Serum LECT2 level can be a predictive biomarker for β‐Catenin activation in HCC.
Comparison of DPP‐4 inhibition versus GLP‐1 analogue supplementation on survival and vascular complications in experimental sepsis (145.2)
Authors: Stamm Paul , Hausding Michael , Kröller‐Schön Swenja , Mader Michael , Agdauletova Saule , Mikhed Yuliya , Pfeffer Amanda , Welschof Philipp , Steven Sebastian , Oelze Matthias , Schulz Eberhard , Klein Thomas , Münzel Thomas , Daiber Andreas 
Published: June 2021

Background: Dipeptidyl peptidase [DPP]‐4 inhibitors are a new class of drug for the treatment of hyperglycemia and recent studies revealed anti‐inflammatory effects of these gliptins in experimental atherosclerosis and septic animals. Therefore the aim of the present study was to compare the effect of gliptins and a direct glucagon‐like peptide (GLP)‐1 analogue on survival and complications in septic shock models.Methods: Mice or rats were treated prophylactically with linagliptin, sitagliptinor liraglutide for 4‐7 days. Lipopolysaccharide (LPS, 10, 17.5 or 20 mg/kg i.p.) was injected on day 3 or 6 of treatment to induce septic shock. Another control group consisted of DPP‐4‐/‐ mice. Survival was monitored over time in response to high dose LPS and vascular function, nitrosyl‐iron hemoglobin in whole blood or oxidative stress were measured 24 hours after the injection of a sub‐lethal dose of LPS. The Gehan‐Breslow‐Wilcoxon‐Test was used for statistical analysis of Kaplan‐Meier curves.Results: Linagliptin and liraglutide therapy or DPP‐4 deficiency improved the survival of mice in the state of a septic shock. Liraglutide improved vascular dysfunction in septic rats without improvement of inflammatory parameters such as nitrosyl‐iron hemoglobin in whole blood or leukocyte‐dependent oxidative stress. Vascular dysfunction and other septic complications were improved by linagliptin and less efficiently by sitagliptin associated with less inflammation.Conclusion: The results reported here on the improvement in the survival of septic animals could provide additional evidence for the potential clinical use of linagliptin and liraglutide, not only for the therapy of diabetic but also septic patients.
Monocyte‐derived macrophages as an active HIV‐1 viral reservoir in patients receiving suppressive cART (145.4)
Authors: Jusino Shirley 
Published: June 2021

Macrophages play a crucial role in HIV‐1 latency and persistent viremia, especially in the establishment of viral reservoir, even when the patients are receiving suppressive cART. Macrophages are long‐lived cells that are resistant to the cytopathic effects of viral replication. Due to their abundant distribution and capacity to migrate into tissues we hypothesized that they can contribute to the maintenance of known viral reservoirs such as that in CD4+ T cells. We differentiated the infected monocytes of four HIV‐ infected patients taking anti‐retroviral therapy to create macrophages. Infected PBMC (peripheral blood mononuclear cells) were cultured for ten days in presence of macrophage colony stimulating factor. After differentiation, the monocyte‐derived macrophages (MDM) were co‐cultured with phytohemagglutinin (PHA)‐activated CD8+‐depleted PBMC’s from healthy patients for four weeks. Supernatants were harvested and analyzed for viral RNA using a sensitive reverse‐transcriptase PCR assay using HIV‐1 gag gene primers. Sequencing of the C2V3 region of the env gene from each patient revealed a 99.6% match with WT HXB2 using HIV Sequence Database (Los Alamos National Laboratory). Results demonstrate that after differentiation into macrophages the infected MDM can still harbor the proviral DNA and were able to release replicate competent virions in the supernatant. Future directions include performing cell to cell infection assay. These findings will be employed in an ex‐vivo model to further analyze HIV‐1 infection and transmission in order to demonstrate whether tissue macrophages are a true viral reservoir in HIV‐1 patients under suppressive cART.Grant Funding Source: NIH Grant R25‐096955
GPCR kinase‐6 inhibits neutrophil infiltration but mediates bacterial killing during lung bacterial infection (145.5)
Authors: Parameswaran Narayanan , Packiriswamy Nandakumar , Lee Taehyung 
Published: June 2021

GPCR kinases (GRKs) are serine/threonine kinases known to be critical players in desensitization of GPCRs. Recent studies have implicated GRKs in a number of different physiological and pathophysiological processes including biased signaling from GPCRs as well as signaling from receptors other than non‐GPCRs. In this study we examined the role of GRK6 (one of the seven GRKs) in E. Coli‐induced lung infection and inflammation model using wild type and GRK6 deficient mice. Intra‐tracheal instillation of E. Coli led to enhanced infiltration of neutrophils into lung tissue of GRK6 deficient mice compared to wild type mice. Enhanced neutrophil infiltration was associated with enhanced IL‐17 expression in the GRK6 deficient lung following infection. Interestingly, even though there was increased neutrophil infiltration, the bacterial persistence and the subsequent mortality were significantly higher in the GRK6 deficient mice. Intriguingly our studies also reveal that GRK6 deficient neutrophils are inefficient in bacterial killing, suggesting that the observed phenotype of increased bacterial load and mortality is likely due to defective bacterial clearance by GRK6 deficient neutrophils. Our studies reveal a previously unrecognized and novel role of GRK6 in bacterial clearance in lung infection model.Grant Funding Source: Supported by NIH
Enteropathogen‐induced toxicity of gut‐microbiota in C. elegans: a new model to investigate mechanisms of post‐infectious intestinal disorders (145.7)
Authors: Gerbaba Teklu , Gupta Pratyush , Wang Xin , Rioux Kevin , Hansen Dave , Buret Andre 
Published: June 2021

Giardia leads to Irritable Bowel Syndrome via obscure mechanisms. We hypothesized that this may due in part to Giardia‐induced changes in microbiota. Using C. elegans as a model, we found that Giardia and commensal E. coli (E. coli HB101) synergistically paralyze and kill C. elegans, while Giardia or bacteria alone did not. Giardia also induced lethal paralysis when co‐incubated with attenuated C. rodentium (ESPF and MAP mutants), with gut mucosal microbiota from healthy human donors, or with mucosal microbiota from inflamed UC (ulcerative colitis) sites, but not with microbiota from non‐inflamed UC sites. The killing effect of Giardia required direct contact of live E. coli with C. elegans. Upon exposure to Giardia and/or C. elegans, E. coli HB101 exhibited distinct genome‐wide expression patterns. A total of 180 genes, including genes for flagella biosynthesis (FliP, FliL), biofilm formation (BssR, BssS), and hydrogen sulfide biosynthesis (CysJ, CysI, CysD, CysN, CysH, CysC), were differentially expressed (>2 fold). Expression data suggests decreased biofilm formation and increased anti‐stress response in E. coli upon exposure to C. elegans, and decreased sulfate reduction upon exposure to Giardia or Giardia and C. elegans. Deletion of the Cysteine B gene (positive regulator of the hydrogen sulfide biosynthesis genes) in E. coli was sufficient to induce lethal paralysis in C. elegans. In conclusion, Giardia alters gut‐microbiota homeostasis by modulating expression of genes in commensal bacteria.Grant Funding Source: NSERC
A novel mechanism for protecting the arthritic joint: microparticles deliver Annexin A1 into cartilage (146.8)
Authors: Headland Sarah , Norling Lucy , Patel Hetal , Dalli Jesmond , Kelly Stephen , Pitzalis Costantino , Dell'Accio Francesco , Perretti Mauro 
Published: June 2021

Microparticles (MPs), subcellular vesicles released from most eukaryotic cells, play important roles in inflammation. We found abundant endogenous neutrophil MPs present in rheumatoid arthritis (RA) synovial fluid compared to paired plasma analyses. These neutrophil MPs were highly enriched in Annexin A1 (AnxA1), a potent anti‐inflammatory protein. Addition of in vitro generated AnxA1+ve neutrophil MPs to IL‐1‐stimulated 3D chondrocyte cultures, rodent cartilage explants, or injected intra‐articularly in a model of inflammatory arthritis, surprisingly, afforded protection from arthritogenesis. This was evidenced by reduced matrix degradation and inflammatory mediator production and an increase in matrix‐synthesis gene expression, effects mediated primarily by AnxA1 and its receptor FPR2/ALX. Current dogma dictates that cartilage is an impenetrable avascular matrix through which metabolites must diffuse; we present the first evidence that MPs can access chondrocytes through the cartilage in vivo. Adoptive transfer of fluorescently labeled mouse neutrophils i.v. into mice at the peak of arthritis demonstrated abundant presence of MPs within arthritic cartilage (wrists, digits), but not intact (femoral head) cartilage, or in naïve mice. With this data we propose that MPs enriched with AnxA1 could offer therapeutic possibilities in the protection of cartilage in situ in arthritis patients.Grant Funding Source: Supported by The Oliver Bird Rheumatism Programme, The Nuffield Foundation; The Wellcome Trust
Sequence of vascular patterning and gene transcription in the chick chorioallantoic membrane (15.1)
Authors: Ysasi Alexandra , Belle Janeil , Bennett Robert , Wagner Willi , Chamoto Kenji , Gibney Barry , Ackermann Maximilian , Konerding Moritz , Tsuda Akira , Mentzer Steven 
Published: June 2021

Introduction: The chick chorioallantoic membrane (CAM) is a well‐established model of both vasculogenesis and angiogenesis; however, little is known about the genetic control of vascular patterning in the CAM.Methods: Using recent advances in chicken genomics, we investigated the relative expression of 84 angiogenesis genes during the growth and remodeling of the CAM microcirculatory network. Chick embryos, cultured ex ovo, were studied during embryonic development days (EDD) 8‐14. UV laser microdissection was used to harvest capillary plexus and 1st, 2nd, and 3rd order conducting vessels for qRT‐PCR analysis.Results: Two transcription peaks were observed between EDD 8 and 14. The first peak occurred prior to EDD 10 and was correlated with maturation of capillary meshwork. The dominant gene expressed during this developmental phase was Epas1. The second peak occurred on EDD 12 and was correlated with growth of the 1st and 2nd order conducting vessels. Dominant transcription peaks were observed in Tgfb3, Timp3, Fn1, F3, Col18a1, Itgb3, Ptk2, Mdk, Sphk1 and Notch1. Nrp2, Mdk, Tgfb3, and Vegfa demonstrated bimodal regulation with peak expression on EDD 9 and 12.Conclusion: We observed bimodal transcriptional activity of the chick CAM during vascular network development. The peaks correlated with the initial maturation of the capillary meshwork followed by expansion of the 1st and 2nd order conducting vessels. These results provide insights into the genetic control of vascular patterning.
Mitochondrial respiratory capacity is not markedly reduced in end‐stage human heart failure (15.6)
Authors: Holzem Katherine , Vinnakota Kalyan , Ravikumar Vinod , Beard Dan , Efimov Igor 
Published: June 2021

Objectives. We aimed to assess mitochondrial (Mt) substrate respiratory capacities in human donor (D) versus failing (F) hearts.Background. Heart failure (HF) is the end‐stage of cardiovascular disease, in which the heart can no longer sustain systemic metabolic demands. During HF progression, the heart switches energy substrate utilization from preferential use of fatty acids (FA) towards greater glucose consumption. We hypothesized that impaired Mt FA respiratory capacity may contribute to this substrate utilization shift.Methods. We isolated intact Mt from left ventricular (LV) tissue collected from D (n=7) and end‐stage F (F, n=9) human hearts and measured Mt respiration. Briefly, hearts were recovered in the operating room and cardioplegically arrested. Mt were isolated via differential centrifugation, and respiration measurements were collected with an oxygraph cell using ADP (350 μM) and pyruvate + malate (PM, 10 mM/2 mM) or palmitoylcarnitine (PC, 25 μM) as substrates.Results. For both substrates, we calculated the apparent capacity for oxidative phosphorylation (State 3) and respiratory control ratios (State 3/4 and State 3/2). In contrast with our hypothesis, Mt capacities for oxidative phosphorylation were not significantly reduced for F compared with D hearts for PM (195.9 ± 19.1 vs 158.8 ± 9.0 nM O2/min/mg, p = 0.12) or PC (122 ± 23.0 vs 91.9 ± 14.4 nM O2/min/mg, p = 0.19). Respiratory control ratios were also not different between D and F heart groups for either substrate. To control for myocardial Mt content, we assessed citrate synthase (CS) specific activity in LV muscle homogenates from the same hearts used for respiration measurements, which were consistent between D and F myocardium (14.5 ± 2.4 vs 14.7 ± 1.8 U/g).Conclusions. Mt respiratory capacities are not markedly impaired in end stage human HF for either glycolytic or FA substrates. Thus, the substrate utilization switch in HF does not appear to be the result of impaired Mt FA oxidation.Grant Funding Source: Supported by NHLBI R01HL11439501A1
Entamoeba histolytica induces caspase‐4/11 activation in inflammasome signaling (152.5)
Authors: Quach Jeanie , Mortimer Leanne , Moreau France , Chadee Kris 
Published: June 2021

A hallmark of amebiasis is acute intestinal inflammation dominated by secretions of pro‐inflammatory cytokines from macrophages. Entamoeba histolytica (Eh) in contact with macrophages activates caspase‐1 by the inflammasome complex resulting in the maturation of IL‐1β and ‐18. The role of inflammatory caspase‐4, ‐5, ‐12 in humans, and caspase‐11, ‐12 in mice are less understood. Caspase‐11, the murine ortholog of caspase‐4, mediates non‐canonical inflammasome activation, suggesting that caspase‐4 may have similar roles. As caspase‐4 might be an immune sensor in Eh infection the aim of this study was to identify the requirements for Eh‐induced caspase‐4/11 activation. Macrophages were treated with live Eh, soluble Eh proteins and secreted components derived from viable Eh. Only live Eh activated caspase‐1, ‐4, and ‐11 in a contact‐dependent manner. Blockade of Eh Gal‐lectin adhesin inhibited binding to macrophages and caspase‐1, ‐4 and ‐11 secretions. Interestingly, cysteine protease 5, another protein critical for Eh virulence, was required for caspase‐1 inflammasome activation but not for caspase‐4/11 activation. To summarize, caspase‐4/11 activation occurred in a contact‐dependent manner and the requirements for their activation are different from caspase‐1, arguing for distinct, non‐redundant roles. Determining how Eh activates these caspases may lead to new therapeutics to treat amebiasis.Grant Funding Source: Supported by NSERC
Targeted angiotensin converting enzyme over‐expression in myelomonocytes prevents cognitive decline in Alzheimer’s‐like disease (153.3)
Authors: Bernstein Kenneth , Koronyo Yosef , Shen Xiao , Fuchs Sebastien , Koronyo‐Hamaoui Maya 
Published: June 2021

The cognitive decline in Alzheimer's disease (AD) is associated with elevated brain levels of amyloid β‐protein (Aβ), particularly Aβ1‐42. Angiotensin‐converting enzyme (ACE) can enzymatically degrade Aβ1‐42 and its overexpression in myelomonocytic cells enhances their immune function. To examine the effect of targeted ACE overexpression on AD, we crossed ACE10/10 mice, which over express ACE in myelomonocytic cells, with the double‐transgenic APPSWE/PS1ΔE9 mouse model of AD (AD+). At 7 months, soluble Aβ1‐42 was reduced by 44% (136 vs 245 pg/mg) and Aβ1‐40 was reduced by 32% (21 vs 31 pg/mg). Plaque burden was reduced by as much as 79% (13 vs 62 103mm2) and insoluble Aβ1‐42 by 64% (189 vs 521 pg/mg). There was also a substantial reduction in astrogliosis (49‐57% at 7 months, 50% at 13 months). AD+ACE10/10 mice demonstrated less overall brain infiltrating cells, consistent with less AD pathology, though ACE‐overexpressing monocytes and macrophages were increasingly abundant surrounding and engulfing Aβ plaque. At 11 and 12 months, AD+ACE10/WT and AD+ACE10/10 mice were virtually equivalent to non‐AD mice in cognitive ability as assessed by maze‐based behavioral tests. This study shows that an enhanced immune response, coupled with increased myelomonocytic cell expression of ACE, resulted in essentially complete prevention of the cognitive decline observed in a murine model of AD.Grant Funding Source: Supported by HL088000, HL110353, and the C.A.R.T fund, UL1TR000124,
Hydrocephalic mouse models of primary ciliary dyskinesia have strain dependent defects in brain morphology and physiology (153.5)
Authors: Finn Rozzy , Lee Lance 
Published: June 2021

Congenital hydrocephalus results from accumulation of cerebrospinal fluid (CSF) and causes severe neurological damage, but the underlying causes are not well understood. Hydrocephalus is associated with primary ciliary dyskinesia (PCD), a pediatric syndrome caused by dysfunction of motile cilia that can also result in sinusitis, male infertility, and situs inversus. We have investigated the causes of hydrocephalus in mouse models of PCD lacking the Pcdp1 and Spef2 proteins. Both models develop gross, lethal hydrocephalus on the C57BL/6J (B6) background but not on 129S6/SvEvTac (129). Histological and immunohistochemical analyses demonstrate that both mutants on B6 have ventricular dilatation, sloughing of ciliated ependyma, disrupted axon myelination, and increased gliosis, indicating significant injury to the cerebral cortex. In contrast, both mutants on both the B6 and 129 backgrounds exhibit perturbed CSF flow despite an absence of substantial morphological defects on 129. These findings indicate that abnormal cilia‐driven flow is not the sole determinant of PCD‐associated hydrocephalus and suggest that there are genetic modifiers that generally influence susceptibility to congenital hydrocephalus.Grant Funding Source: Supported by the NIH (1P20GM103620‐01A1)
Hyperhomocysteinemia inhibits mouse early postnatal neurogenesis, the role of oxidative stress (153.6)
Authors: Zhang Lixiao 
Published: June 2021

HHcy is a risk factor of cardiovascular disease and neurodegenerative disease. There is a strong correlation between HHCY and cognitive disorders or Alzheimer's disease. Patients with Cystathionine‐β‐synthase (CBS) deficiency suffer from mental retardation and psychiatric complications, which begins from neonatal period, suggesting a role of HHcy in neural development. In this study, we investigate the effect of HHcy on early postnatal brain development and related molecular mechanisms. We found that severe HHcy markedly reduce body weight, whole brain size, hippocampal volume and neuron number in dentate gyrus of hippocampus in mouse with CBS gene deficiency, starting from postnatal 7 days. Since neurogenesis is critical for early postnatal hippocampus development, we examined BrdU incorporation in hippocampus of CBS‐/‐ mouse and found that severe HHcy decreased BrdU and NeuN (neuron marker) double positive cells in dentate gyrus starting from postnatal 7 days, a time point matching the occurrence of hippocampus developmental defect. Next, we examined neural progenitor cells (NPC) proliferation in cultured NPC isolated from neonatal mouse hippocampus. We found that DL‐Hcy (200umol) decreased neurosphere size, a standard index of NPC proliferation, without affecting NPC cell death (as demonstrated by cell viability assay with 7‐AAD staining). Further, Hcy increases of cytosolic but not mitochondria ROS production in cultured NPC by electron‐spin resonance (ESR) measurement. ROS scavenger, superoxide dismutase (SOD), reverses Hcy‐induced cytosolic ROS generation and inhibition of cultured NPC proliferation. In conclusion, HHcy impairs early postnatal hippocampal development and neurogenesis, at least in part, via cytosolic oxidative stressGrant Funding Source: NIH