bluuebunny/crossref_metadata_2025_split huggingface dataset:
The mechanisms related to the cardioprotective effects of protein kinase C epsilon (PKC ε‐) peptide inhibitor in ischemia/reperfusion (I/R) injury when given at reperfusion
Authors: Chen Qian , Kay Helen Young , Teng Jane , Burkhart Samantha , Zambrano Christopher , Krass Samuel , Adams Jovan , Grilli Christopher , Guglielmello Giuseppe , Brue Richard , Young Lindon Howard 
Published: June 2021

PKC is a key enzyme involved in I/R injury. Previously, we showed that PKC ε− significantly restored postreperfused cardiac function up to 99% in polymorphonuclear leukocytes (PMNs, 200×106) induced myocardial I/R injury rat model. In this study, we further investigated the effect of PKC ε− on cardiac I/R injury and the underlying mechanisms. Compared to I/R+PMN hearts, we found that PKC ε− treated I/R+PMN hearts exhibited less cell injury and significantly lower PMN vascular adherence/infiltration in 45 min posterperfused heart tissue by using triphenyltetrazolium chloride staining, hemoxylin & eosin stain and myeloperoxidase assay. Furthermore, expression of endothelial adhesion molecules (i.e., intercellular adhesion molecule‐1; ICAM‐1) which contributes to PMN adherence/infiltration was also significantly decreased by 47±5% (P<0.05). Moreover, the NOS inhibitor, NG‐nitro‐L‐arginine methyl ester, did not block the cardioprotection of PKC ε−. However, PKC ε− (0.4 mg/Kg) significantly decreased hydrogen peroxide release during reperfusion in an in vivo femoral I/R model. Therefore, cardioprotection of PKC ε− is possibly related to attenuating ICAM‐1 expression, PMN adherence/infiltration and oxidative stress during reperfusion.This study was supported by NHLBI Grant 1R15HL‐76235‐01 and Center For Chronic Disorders Of Aging at PCOM.
INSULAR CORTEX NORADRENERGIC NEUROTRANSMISSION MODULATES THE BAROREFLEX IN RATS.
Authors: Alves Fernando Henrique Ferrari , Crestani Carlos Cesar , de Aguiar Correa Fernando Morgan 
Published: June 2021

Previous study from our laboratory indicated that bilateral microinjections of CoCl2 into the IC evoked reversible decrease in the bradycardiac reflex, suggesting that synapses in the IC modulates the parasympathetic component of the baroreflex. Thus the aim of the present study was to verify the participation of the IC‐noradrenergic neurotransmission in the modulation of the parasympathetic limb of the baroreflex.Microinjection of selective noradrenergic á1‐adrenoceptor antagonist WB4101 into the IC caused a shift of the reflex threshold pressure bradycardiac responses to MAP increases toward higher MAP values (F=5, p<0.05), without affecting baroreflex gain (F=0.08, p>0.05). The effect of WB 4101 was reversible and the HR response returned to pre‐injection levels after 60 min (p>0.05). However, bilateral microinjection of the selective noradrenergic á2‐receptors antagonist RX821002 (F= 0,006, p> 0.05) did not affected baroreflex responses.Our data indicate that noradrenergic á1‐receptors in the IC are involved in the modulation of the parasympathetic baroreflex component. Financial support: FAEPA, CNPq
Sympathetic innervation of the skin in type 2 diabetes mellitus
Authors: Strom Nicholas Alan , Roberts Shelly K , Kingsley‐Berg Shirley A , Charkoudian Nisha 
Published: June 2021

In humans, sympathetic nerves in the skin provide tonic vasoconstrictor innervation. Although neural changes in type 2 diabetes mellitus (T2DM) are well recognized, it is unclear to what extent the activity of these vasoconstrictor nerves is altered in individuals with relatively uncomplicated T2DM. We tested the hypothesis that skin sympathetic nerve activity (SSNA) is decreased at rest in individuals with T2DM compared to healthy controls (C), and that the increase in SSNA with whole body cooling is smaller in T2DM than in C. We measured SSNA using microneurography, skin blood flow using laser‐Doppler flowmetry (LDF), and arterial pressure using Finometer in T2DM and C subjects at baseline and during 3–5 minutes of whole body cooling. LDF was measured on the foot at the site of innervation of the measured SSNA signal. Whole body cooling was followed by 35 min of local warming of the skin to 42°C to determine maximum cutaneous vascular conductance. In preliminary studies (N=3 per group), SSNA at baseline (T2DM: 22 ± 8 vs. C: 30 ± 1 bursts/min) and during whole body cooling (T2DM: 28 ± 11 vs. C: 43 ± 2 bursts/min; deltas: T2DM: + 6 ± 3 vs. C: +13 ± 1 bursts/min) tended to be lower in T2DM compared to C. Our data suggest that changes in control of SSNA in T2DM contribute to altered thermoregulatory responses in these individuals.Supported by NIH R01 HL73884 and CTSA UL1‐RR24150.
Alpha methyl tyrosine inhibits rotenone‐ and staurosporine‐induced apoptosis of adrenal chromaffin cells
Authors: Woodman Ryan , Lockette Warren 
Published: June 2021

The increased synthesis of catecholamines following traumatic brain injury (TBI) is accompanied by the generation of reactive oxygen species (ROS) that damage neuronal tissues. We hypothesized that inhibition of catecholamine synthesis and ROS formation in catecholamine‐containing neurons with alpha‐methyl tyrosine (AMT) could improve outcome in TBI. Rotenone and staurosporine induce ROS‐dependent apoptosis in adrenal chromaffin cells that synthesize catecholamines. We determined whether or not this inhibitor of catecholamine synthesis could block rotenone‐ and staurosporine‐induced apoptosis of cultured PC12 cells. Cells were incubated for 24 h with either rotenone (10 uM) or staurosporine (0.1 uM), with or without AMT (10 uM); apoptosis was quantified using a luminescent caspase activity assay, and cell viability was determined with cell counts (n = 56 for each intervention, * p < 0.01).AMT significantly reduced rotenone‐ and staurosporine‐induced apoptosis in cultured chromaffin cells and may ameliorate ROS‐induced damage in catecholaminergic neurons. (These studies were supported by Naval Medical Center, San Diego.)
The influence of aging on the in vivo properties of human patellar tendon
Authors: Dickinson Jared M , Carroll Chad C , Haus Jacob M , Lee Gary A , Hollon Christopher J , Aagaard Per , Magnusson S Peter , Trappe Todd A 
Published: June 2021

We investigated the in vivo mechanical properties of the patellar tendon in 37 men and women (11 Young, 27±1 y; 26 Old, 65±1 y). Patella and tibial displacement were monitored with ultrasonography during ramped isometric contractions of the knee extensors and magnetic resonance imaging was used to determine tendon cross‐sectional area (CSA), length, and signal intensity (SI). At maximal levels of force, deformation (15%, p=0.05), stress (23%), and strain (13%) were higher in Young compared to Old (p<0.05). However, aging did not alter the force‐deformation or stress‐strain characteristics of the patellar tendon. Tendon CSA (12%) and SI (24%) decreased with aging (p<0.05) but these differences were isolated to the mid‐region of the tendon. Independent of age, deformation (18%), stiffness (35%), stress (41%), CSA (28%), and length (11%) were greater (p<0.05) in men compared to women. After force normalization, stress (26%) and strain (22%) were higher in women compared to men (p<0.05). Declines in quadriceps muscle function with aging are not a result of changes in patellar tendon mechanical properties. The age‐associated decrease in SI indirectly suggests that the internal milieu of the tendon is altered with aging.NIH R01 AG020532 (TT), APS Postdoctoral Initiative Award (CC)
Changes in EPC levels and gene expression of homing factors in exercising human skeletal muscle
Authors: Strömberg Anna , Rullman Eric , Jansson Eva , Gustafsson Thomas 
Published: June 2021

In the present study the aim was to investigate the circulating level of EPCs defined by expression of VEGFR2 following an acute bout of exercise, as well as plasma levels and skeletal muscle gene expression of factors hypothesized to be involved in homing of EPCs.10 healthy, moderately active males performed 1 h of cycle exercise. Muscle biopsies from the m. vastus lateralis of both legs were obtained before, directly after and 2 h after the exercise bout. Blood samples for flow cytometric measure of EPC numbers and ELISA measurements of plasma protein levels were retrieved before, directly after, 30 minutes after and 2 h after the exercise bout. The circulating level of EPCs increased robustly after the exercise bout. The plasma level of G‐CSF was significantly increased directly after the bout when adjusted for plasma albumin concentration. ICAM‐1 and VEGFR2 mRNA levels were increased 2 h post exercise. The present results indicate that exercise induces recruitment of EPCs to the circulation and prepares the tissue for homing of these cells.
Xanthine Oxidase and NADPH Oxidase Induce Cardiovascular Endothelial Dysfunction During Hyperuricemia
Authors: Zhang Suhua , Huang Harer , Serpillon Sabrina , Wang Ziping , Yu Xiaohan , Hintze Thomas H. 
Published: June 2021

Hyperuricemia(HU) induces cardiovascular diseases associated with O2− production through the activation of xanthine oxidase(XO). We hypothesized that HU can induce cardiovascular endothelial dysfunction and that both XO and NADPH oxidase are involved. Three groups of SD male rats, control(C), oxonic acid(OA‐ a uricase inhibitor) and OA + allopurinol(OAA) were studied for five weeks. In the OA group, serum uric acid (SUA, mg/dl) was significantly increased (2.5 ± 0.3 vs. 0.8 ± 0.1 in C, 1.9 ± 0.1 in OAA); Systolic blood pressure(SBP, mmHg) was elevated (170 ± 4.4 vs. 144 ± 1.1 in C, 157 ± 2.8 in OAA). There was a linear correlation between SUA and SBP (R2 = 0.82). The total peripheral resistance by echocardiography was increased (P<0.05). The ability of the NO agonists BK and Cch to reduce myocardial O2 consumption (MVO2) was impaired (to 15% for BK or 20% for Cch vs.25% in C) in vitro. However, this was reversed by allopurinol administered in vivo, and restored in the presence of allopurinol, apocynin or tempol in vitro. Western blots of left ventricle showed that the protein p47, nitrotyrosine and P‐p38/p38 ratio were upregulated (P < 0.05, respectively). HU enhanced bioactivity of XO and also NADPH oxidase, by a mechanism involving the activation of p47 protein and p38 kinase. NO is consumed via reaction with O2− and subsequently the ability of NO to control MVO2 and endothelium‐dependent vasorelaxation was attenuated.Supported by HL‐PO1‐43023 grant.
Impaired autoregulation and TGF responses in NKCC1‐deficient mice
Authors: Oppermann Mona , Lorenz John , Wall Susan , Schnermann Jurgen 
Published: June 2021

To explore the role of NKCC1 in the regulation of renal hemodynamics we determined tubuloglomerular feedback (TGF) and renal blood flow (RBF) autoregulation in wild type (WT) and NKCC1‐deficient mice.Tissue‐specific basal renal blood flow (RBF) was similar in NKCC1−/− and WT mice (5.82 ± 0.27 vs. 6.20 ± 0.42 ml/min/g; p=.43), but absolute RBF was lower in NKCC1−/− as a result of a reduced kidney weight (479 vs. 603 mg; p=.003). Maximum TGF responses of stop flow pressure were markedly lower in NKCC1−/ − than WT mice (2.9 ± 0.4 vs. 12.4 ± 0.8 mmHg, p<.001) while blood pressure under anesthesia was identical (90 mm Hg). In vivo perfused loops of Henle (6 nl/min) showed unaltered distal [Cl] and absorption rates in NKCC1−/ − and WT mice (54.4 vs. 56.3 mEq/l; 719 vs. 728 pEq/min). Renal vascular resistance (RVR) of WT responded to a step increase of renal arterial pressure with a fast component (onset at 1 s, duration 6 s) and a slow component (onset at 7 s, duration 10 s) establishing full autoregulation (restoration of 100% of initial RBF) after 17s. In contrast, RVR adjustments in NKCC1−/ − mice were slower in onset and longer in duration reaching completion after 58 s.In summary, markedly reduced TGF and slower autoregulatory responses in NKCC1−/ − mice suggest that NKCC1‐mediated ion fluxes are important for maintaining the contractility of renal resistance vessels.
Impact of oxidative stress on epithelial repair and alveolar oedema, within in vitro model of lung injury
Authors: Chupin Cécile , Privé Anik , Brochiero Emmanuelle , Berthiaume Yves 
Published: June 2021

Repair of lung injury is a complex process including epithelial growth, alveolar clearance and down‐regulation of inflammatory response. The impacts of oxidative stress in this process are still unknown. To study this question, we developed an in vitro model of lung injury to characterise the molecular and cellular mechanisms of distal lung epithelial repair. Alveolar epithelial cells in primary culture were submitted to oxidative stress with bleomycin (B : 12,5–150mU/ml) or DMNQ (D : 2,5–15μM). Bleomycin and DMNQ inhibit the epithelial repair (24–48h) following a mechanical injury in a time and concentration dependent manner (p<0,0001). These agents also decrease by 60% and 80% respectively the cell migration in Boyden's chamber (p<0,0001) and decrease cell proliferation measured as thymidine 3H incorporation by 95% and 70% (p<0,0001). These results show that oxidative stress has an impact on alveolar epithelial cell repair by inhibiting the cell migration and proliferation processes. The impact of bleomycin on the ionic transport was studied in Ussing chamber. The treatment decreases by 37% the total as well as amiloride‐sensitive transepithelial current (p<0,05). Basolateral permeabilisation in presence of a Na gradient shows that the epithelial Na channel (ENaC) is not involved in this decrease. The oxidative stress therefore in addition to inhibiting epithelial repair also decreases the Na transport involved in lung liquid clearance.Supported by RSR‐FRSQ, CCFF, CIHR.
A systems biology approach for the validation of eQTL in obesity
Authors: Estrada‐Smith Daria , Munoz Gloria , Wang Shilang , Sorensen Peter , Dobrin Radu , Rawls John , Pomp Daniel 
Published: June 2021

M16 mice are polygenic obese models created by 27 generations of selection for weight gain from an ICR background. Recent transcriptional analysis of adipose and hypothalamus from ~300 M16 × ICR F2 animals identified expression variants (eQTL) and cross‐tissue co‐expression networks of coordinately expressed genes that regulate many processes including satiety, circadian oscillations and stress responses.The purpose of this project is to experimentally validate effects of eQTL and genes in co‐expression networks on obesity phenotypes. Approaches include a Zebrafish screen of morhpholinos, over‐expression and expression knock down by RNAi in adipocyte differentiation, and sequence analysis of regulatory regions. Preliminary results suggest a significant effect of several candidate genes on fat utilization and storage in Zebrafish morpholinos. Sequence analysis of regulatory intervals show variations that alter transcription factor binding sites. These differences may underlie changes in the regulation of gene expression in obese mice. Studies on changes in adipocyte differentiation as a consequence of altered expression levels are just being initiated. Given the biological complexity of fat accretion and energy regulation, a systems biology approach utilizing cumulative statistical and experimental methods may provide needed insight into the molecular basis of obesity.
BD™ Heparin Binding Plate: An Introduction to its Applications
Authors: Wiles Michelle , Whittle Jason David , Novak Christopher 
Published: June 2021

BD™ Heparin Binding Plate: An Introduction to its ApplicationsUntil now researchers have been constrained by the inability to immobilise heparin and heparan sulphate onto solid supports without having to first modify the molecule in some way – e.g. biotinylation or conjugation to a carrier protein. The BD™ Heparin Binding Plate (formerly EpranEx), allows researchers to simply and efficiently immobilise these molecules without modification, retaining their functional ability to interact with other biomolecules. Numerous heparin fractions and a range of heparan sulphates have been successfully bound to the plate. Heparin‐binding molecules (IL8 and LINK_TSG6) were used to demonstrate the functional activity of several heparin fractions with reproducible results (n=24). Binding capacity of the plate was determined to be 200 ng/well using 35S heparin. The BD™ Heparin Binding Plate facilitates the development of novel assays to study the wide range of biological functions that involve the participation of heparin or heparan sulphate.
Human CD4+ effector memory T cells are pre‐sensitized to Fas‐induced apoptosis due to more efficient receptor signaling
Authors: Cruz Anthony C , Ramaswamy Madhu , Siegel Richard M 
Published: June 2021

Naïve T cells activated through acute antigen stimulation expand and contract independently of the presence of the death receptor Fas. However, Fas‐FasL interactions play a critical role in TCR‐induced apoptosis of activated CD4+ T cells. Fas deficiency prompts the accumulation of CD44+ memory phenotype T cells in mice, suggesting Fas may play a more prominent role in apoptosis of memory T cells. The sensitivity of cells derived from naïve versus memory CD4+ T cells to Fas‐induced apoptosis has not been addressed. We compared the susceptibility of purified naïve versus memory human CD4+ T cells, both directly ex vivo and after in vitro activation and expansion, to undergo Fas‐induced apoptosis.Remarkably, effector memory phenotype (CD27− CCR7−) cells were the most sensitive to non‐crosslinked anti‐Fas induced cell death. We have previously shown a correlation between lipid raft‐associated Fas and susceptibility to undergo apoptosis. Memory cells have increased lipid raft‐associated Fas surface protein versus naïve cells, which could account for increased sensitivity to Fas. Memory cells have more efficient assembly and activation of proximal Fas signaling components, including FADD and Caspase 8. These results suggest that effector memory cells have more efficient proximal Fas signaling and are intrinsically more sensitive to Fas‐induced apoptosis, possibly due to lipid raft localiztion of Fas.
Strong expression of CD99 on human plasma cells, triggering homotypic aggregation
Authors: Park Seo‐Jeong , Park Young S. , Kang Soon‐Suk , Kim Youngji , Park Seong Hoe , Park Chan‐Sik 
Published: June 2021

Plasma cells are terminally differentiated antibody producing cells. Recently, signaling molecules controlling plasma cell functions have been recognized as a crucial component of humoral immune response. We have established ex‐vivo plasma cell culture system. CD99 is a 32kD type I transmembrane protein that is highly expressed on hematopoietic precursor cells and some malignant neoplasms. CD99 is known to be involved in cell adhesion, migration, apoptosis and secretion. We report that CD99 is strongly expressed on developing human plasma cells. These findings were also consistent with immunohistochemistry and flow cytometric results on in vivo plasma cells and plasmacytoma. Engagement of the CD99 molecule by monoclonal antibodies, DN16 and YG32, triggered homotypic aggregation of plasma cell line RPMI8226. These observations suggest that CD99 may play a critical role in humoral immune response by controlling adhesion or migration of plasma cells.This study was supported by a grant of the Korea Health 21 R & D Project, Ministry of Health & Welfare, Republic of Korea. (Project No.: A040004)
TGFb and IL2 maintain helminth‐induced FOXP3 expression and increase relative FOXP3 levels in murine gut lamina propria CD8 T cells
Authors: Stoyanoff Korynn , Blum Arthur , Hang Long , Setiawan Tommy , Weinstock Joel V. 
Published: June 2021

Intro: The immune system limits gut inflammation. H. polygyrus is a murine intestinal helminth. In lamina propria (Lp), H. polygyrus infection up‐regulates a marker of Tregs, FOXP3, in CD8+T cells and induces Th2 and regulatory cytokines. This study examined if worm‐induced cytokines enhance FOXP3 expression.Method: Reporter mice, which express a FOXP3‐EGFP fusion protein, were infected with H. polygyrus. After 2 wks, Lp mononuclear cells (LPMC) were isolated. Unfractionated LPMC and FACS sorted EGFP+ and EGFP− T cells were cultured 48hr with or without various cytokines (IL10, TGFb, IL2, IL4). Cells then were stained for CD8 and Thy1.2 and analyzed for FOXP3 expression with FACS. Controls included cells from littermates without worms.Results: In LPMC from worm‐infected mice, TGFb/IL2 together increased FOXP3+CD8+ T cell number and degree of expression: 2.23 ± 0.21, p = 0.002, N = 5 fold increase in number, 1.78 ± 0.18, p = 0.0065, N = 3 fold change in degree of expression. Mesenteric lymph node or spleen cells were unaffected. EGFP− LPMC cultured with TGFb/IL2 did not turn +. EGFP+ cells cultured alone lose FOXP3. TGFb/IL2 added to these cultures maintained FOXP3 expression.Discussion: H. polygyrus infection abrogates colitis. Lp CD8+ T cells limit gut inflammation. TGFb/IL2, induced in the gut by worms, maintain but do not induce high FOXP3 levels in CD8+ Tregs and may promote regulation. (DK38327, 058755, 034928)
The mechanism of synergy between cell‐mediated and humoral immune responses in protection against acute respiratory pathogens
Authors: Kirimanjeswara Girish Soorappa , Metzger Dennis W 
Published: June 2021

To maintain the sterility of the lungs, cell‐mediated and humoral responses (CMI and HI) co‐operate to rapidly eliminate pathogens. The importance of interactions between the two arms of immune responses for protection against intracellular pathogens is well appreciated but not understood. Therefore, the objective of this study was to elucidate the mechanism of synergy between CMI and HI in enhancing microbicidal activities of phagocytes. Using a mouse model of respiratory tularemia, we observed that specific antibodies in concert with IFN‐γ rapidly eliminated intracellular Francisella tularensis. Similarly, IFN‐γ‐activated, but not resting alveolar macrophages (AMs) mediated rapid killing of opsonized bacteria. Further analysis revealed that both FcγR and IFN‐γR dependent signaling events were necessary and led to enhanced RNS and ROS generation, which were also essential for bacterial killing. In addition, differential trafficking of opsonized bacteria within AMs was found to be necessary. Studies to determine the compartment where opsonized bacteria are killed by activated AMs and the cellular events that result in the formation of these compartments are currently in progress. These results establish a potential mechanism to explain the synergy between CMI and HI and provide an opportunity for intervention to augment the efficacy of antibodies and vaccines.PO1 AI056320U54 AI057158γ
Dietary fat modulates intestinal absorption of luminal gut antigens
Authors: Eckhardt Erik , Ghoshal Sarbani , Ward Martin , Woodward Jerold , de Villiers Willem 
Published: June 2021

BACKGROUND: Mesenteric lymph nodes (MLN) are important for proper immune responses to gut antigens. Dietary long‐chain fat stimulates mesenteric lymph flow and lymphatic secretion of chylomicrons (CM) which have been shown to bind lipopolysaccharides (LPS) and amphiphilic peptides.HYPOTHESIS: CM formation promotes intestinal absorption of LPS and peptidic antigens.METHODS: Antigen absorption was measured in mice and CaCo‐2 cells, absorbed ovalbumin (OVA) was detected by adoptive T‐cell (DO11.10) transfer.RESULTS: Fasted mice gavaged with LPS absorbed 3‐times more LPS into blood and MLN when subsequently gavaged with triolein than with tributyrin. This was abolished by an inhibitor of CM formation, Pluronic L‐81. Absorbed LPS was associated with plasma CM remnants. CaCo‐2 cells pretreated with LPS secreted more LPS from cell‐associated pools into basolateral medium when stimulated with oleic acid than with butyric acid; this was also Pl‐81 sensitive. MLN P38 MAPK phosphorylation was higher after gavage with triolein than with tributyrin. Balb/C mice adoptively transfered with CFSE‐labeled DO11.10 CD4 T‐cells and gavaged with OVA and triolein had markedly more CFSE‐labeled cells in MLN and spleen than mice gavaged with OVA and tributyrin; T‐cell proliferation was also elevated.CONCLUSION: Dietary fat may affect the intestinal immune system by modulating absorption and MLN delivery of gut antigens.