bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of Vitis vinifera extract supplementation on electronegative low‐density lipoprotein (‐) during military training (830.33)
Authors: Daleprane Julio , Pitaluga Mário , Passos Magna , Koury Josely
Published: June 2021

The purpose of the present study was investigating the effect of Vitis Vinifera Extract supplementation on electronegative low‐density lipoprotein (LDL(‐)). Brazilian healthy military without hyperglycemia, diabetes mellitus and endocrine disease were enrolled in this study. All subjects were high physically military trained. Fifty participants (ages: 18‐23 years; total body mass: 65‐78 kg) were enrolled in a double‐blinded, placebo‐controlled study using a crossover design. The participants received either supplemental (S, 205 mg one single dose) or placebo (P) on the begging of the training. After an overnight fast samples of whole blood were taken from a group of conscripts four times: at the beginning (T0, supplementation, n = 15), after 24h of intensify military activity (T1, n = 15), at the end of 48h of military training (T3, n = 13) and after 24h of rest. LDL(‐) levels was determined by ELISA. No differences were detected on the beginning of the military training between both groups (P: 1.18±0.45 U/L and S: 1.19±0.75 U/L). The placebo group presented a increased (p<0.05) levels of LDL(‐) during military training (T1=1.89±0.69 U/L; T2=2.95±1.32 U/L; T3=3.33±0.92 U/L). In the S group there was a decreased in the levels of LDL(‐) in T1 (0.69±0.62) and a increased in T2 and T3. But when we compared P x S, S presented a reduction in levels of LDL(‐). We may conclude that a single dose of 205 mg polyphenols was able to prevent a increasing levels of LDL(‐) in young military man during a intensive military training .
Ectopic mineralization in late stage atherosclerosis of heme oxygenase‐1 deficient mice (832.11)
Authors: Rasul Amna , St.Amand Timothy , Funk Colin , Brunt Keith
Published: June 2021

Background: Heme oxygenase‐1 (HO‐1) has a role in vascular protection. Loss of HO‐1 activity has previously been shown to accelerate the onset and severity of atherosclerotic plaques, while the opposite has been reported with elevated HO‐1 activity. HO‐1 confers cytoprotection to endothelial and smooth muscle cells, yet may also limit their proliferation. The role of HO‐1 in late‐stage atherosclerotic plaque stability has not yet been examined. Hypothesis: Loss of HO‐1 cytoprotection confers plaque instability in late‐stage atherosclerotic lesions of mice. Methods: Both HO‐1 wild‐type, ApoE deficient (HO‐1+/+/ApoE‐/‐, knockout; KO) and HO‐l deficient and ApoE deficient (HO‐1‐/‐/ApoE‐/‐, double knockout; DKO) male mice were fed a Western diet for six months. Histology assessment of brachiocephalic arteries was performed to determine plaque composition. Results: Lesions from DKO‐mice were smaller, more calcified, with greater extracellular matrix (ECM) compared to KO‐mice whose lesions were larger, more lipid dense and acellular. Conclusions: HO‐1 gene disruption in mice does not lead to atherosclerotic plaque with characteristics of instability. However, highly calcified plaques are directly correlated with poor prognosis. This may have implications for patients with low levels of HO‐1, whose lesions may be clinically silent longer and in the event of rupture more deleterious.
The role of serine protease in the respiratory development (834.12)
Authors: Hsu Yu Chen , Fan Meng Ni , Huang Hsiang‐Po , Yu I‐Shing , Lin Shu‐Rung , Lin Shu‐Wha
Published: June 2021

The failure of complete diaphragm development, leading to a herniation or elevation of abdominal components into the pleural cavity, is thought to have a number of roles in the respiratory development. Here we reported a genetically modified mouse model, which have deletion in the gene coding for type II transmembrane serine protease‐1 (TMPRSS1), have defective diaphragms that mimic mild forms of the phenotypes of the diaphragm elevation in human. We notice the diaphragm of the genetically modified mouse line attached to the rib cage at a higher position compared to the wild type mice, as evidenced by the larger gap present between the subcostal margin and the diaphragm. As a result, the liver was shifted upward. Additionally, the average diameter and diaphragm area of these mice were found to be significantly smaller than those of wild type mice. While no difference in the thickness of the muscular layers was observed between the genetically modified and wild type mice, histology and morphometry analysis showed that the tendinous muscle of the genetically modified mice was significantly thinner than the wild type mice. The pulmonary functions, such as lung resistance and compliance, were also significantly impaired in the genetically modified mice. It is possible this is due to the higher position of the diaphragm and restricted expansion of the lung, since no significant differences in the weight or histology of lung tissue from hepsin KO and WT mice were detected. These observations suggest that during early development, the serine protease may play a role in maintaining structure and function of the diaphragm and we would suggest that a genetic analysis of this modified be performed in the patients of diaphragm elevation.
Protective immunotherapy against seasonal allergy in horses (834.2)
Authors: Venugopal Changaram , Prayaga Sudhirdas , Eades Susan
Published: June 2021

The study objective was to evaluate the effectiveness of active and passive immunotherapy in horses affected with recurrent airway obstruction (RAO), using a newly developed peptide and antibodies to the peptide. This peptide is part of an endogenous protein and has a sequence homology to some common environmental allergens. RAO is a type‐I immediate hypersensitivity response involving reaginic antibodies (IgE and IgG), and is a model for human asthma. Our hypothesis is that a protective immune response to asthma can be induced by active vaccination or by passive immunotherapy. Five RAO‐affected horses with a history of seasonal RAO, transpulmonary pressure >15 cm of H2O, and a clinical score (CS) of 5 and above were selected. Either of the two doses of the antibody, 0.1 mg/kg or 0.2 mg/kg, was administered subcutaneously to 2 horses each. A third dose 0.3 mg/kg was given to the fifth horse. The peptide (0.1 mg/kg) was used to vaccinate two additional RAO‐horses. After closely watching them for 2 days, they were returned to the pasture. Blood samples were collected on day 0 (pre‐immune sample), day 1 and every 7th day for two months along with clinical scores. A dose related decrease in CS was observed in horses that received antibodies. The serum antibody titer was below detection levels by ELISA. The vaccinated horses showed significant protective antibody titer when the season arrived. The study suggests that protective immunotherapy early in the season has some therapeutic potential for RAO‐affected horses.

Grant Funding Source: Supported by EHSP, LSU‐SVM
Influence of food allergy on the course of bronchial asthma in children (834.5)
Authors: Urazova S. , Turebaev D.
Published: June 2021

Food allergy is a common type of allergy reactions in children. At the same time, there is little explored the impact of food allergy on the development and course of bronchial asthma in children.

Objective: to study the characteristics and clinical manifestations of bronchial asthma in children.

Material. 100 children with bronchial asthma associated with food sensitization (experimental group) have been examined. The control group consisted of 60 children with bronchial asthma, who had no manifestations of food allergy. The age of patients was from 1 year to 16 years.

The results of the study.It is noted more previous (p <0,01) beginning bronchial asthma in children who had food allergens as the cause significant factors in its exacerbation in comparison to the control group. Bronchial asthma attacks in children with food sensitization were recorded in the experimental group was 1.8 times more than in control group. Severe bronchial asthma was noted in 2 times more often in children with food sensitization than in the control group. The higher level of total IgE (p<0,05) in children with bronchial asthma exacerbation to food antigens from 6 to 9 years of age was noted in comparison to control group. Gastroduodenit(38.2% and 41.3%) was dominated inthe experimental and the control group, respectivelyand eyunit, esophagitis in children with acute asthma were found in 2 times more likely than children in the control group.
Changes during development of COX 1 and 2 in heart, abdominal and thoracic aorta (837.11)
Authors: Acevedo‐Villavicencio Nallely , Arellano Monica , Ramirez‐Sanchez Israel , Mera‐Jimenez Elvia , Lopez‐Calderon Emilio , Guevara‐Balcazar Gustavo , Castillo‐Hernandez Maria
Published: June 2021

Cyclooxigenase 1 and 2 have been related in the release of prostanoids that regulate the effect of various agonists as in the case of phenylephrine, but its unknown that how this enzyme is involved in the contractile response to phenylephrine age‐dependent. The aim of this paper is to analyze changes of COX 1 and 2 involvements in the contractile response to phenylephrine in the thoracic and abdominal aorta and coronary artery of pubescent, young and old rats. It has been describe that during development there are changes in the activity of some enzymatic pathways, in this work we analyze the change in the involvement of cyclooxygenase and PGs in the contractile effect of phenylephrine with age. Methods: we used male rats of 6, 16 weeks and 1 year of age. Rats were anesthetized with pentobarbital (50 mg / kg), after that we proceeded to obtain the thoracic aorta and abdominal aorta and the heart and they were placed in an isolated organ system where we proceeded to make concentration response curves to phenylephrine. On the other hand we obtain heart and aorta for the western blot analysis and the immunohistochemistry assay of COX 1 and COX 2. Conclusions: COX1 increase during development. On the other hand COX2 decrease in the elderly stage only in thoracic aorta.

Grant Funding Source: COFAA / IPN
Assessment of cardiovascular effects in vitro and in vivo of diterpenes sclareol and manool in normal and hypertensive rats (837.7)
Authors: Vento Daniella , Celotto Andrea , Silveira Ana Paula , Sumarelli Agnes , Evora Paulo , Rodrigues Alfredo
Published: June 2021

Assessment of cardiovascular effects in vitro and in vivo of diterpenes Sclareol and Manool in normal and hypertensive rats
Daniella Alves Vento1, Andrea Carla Celotto1, Ana Paula Cassiano Silveira1, Agnes Afrodite Sumarelli1, Paulo Roberto Évora1, Alfredo José Rodrigues1
1Department of Surgery Anatomy, University of São Paulo – Ribeirão Preto, Brazil Cardiovascular diseases are causes of morbidity and mortality worldwide. The naturally compounds derived from plants, especially the diterpenes sclareol and manool are promising sources for the development of therapeutic agents for the treatment of cardiovascular diseases including hypertension. The aim of this study was to investigate the cardiovascular effect (in vitro and in vivo) of sclareol and manool in male Wistar rats. Were performed, in vitro, dose‐response curves for sclareol and manool (10‐10 to 10‐4 M) in aorta of normal rats with and without endothelium pre‐contracted with phenylephrine. The in vivo experiments were performed using normal and hypertensive rats. After anesthetized (xylazine / ketamine), the animals were cannulated femoral artery and vein for injection of the compounds and measurement of blood pressure, respectively. Doses of 10, 20 and 40mg/kg was administered as a bolus followed by checking blood pressure. In the study vascular reactivity, both as manool and sclareol promoted relaxation of 50% rings and 20% by endothelial rings without endothelium. This relaxation was inhibited by L ‐NAME. The administration of three doses of sclareol in normal rats caused a reduction in blood pressure of 25 , 25 and 30 mmHg, whereas administration of manool promoted a pressure reduction of 10, 10 and 20 mmHg. Already in hypertensive animals pressure reduction is promoted by sclareol 50 , 50 and 60 mmHg and the manool were 50 , 50 and 50 mmHg. Therefore, from the results it can be seen that sclareol and manool have vasodilatory effect mediated by nitric oxide and hypotensive, especially when blood pressure levels are elevated.
The FAAH inhibitor PF‐04457845 has THC‐like rewarding and reinstatement effects in squirrel monkeys and increases dopamine levels in the nucleus accumbens shell in rats (838.6)
Authors: Justinova Zuzana , Mascia Paola , Secci Maria , Redhi Godfrey , Piomelli Daniele , Goldberg Steven
Published: June 2021

FAAH inhibitors (like URB597), that increase brain levels of anandamide, OEA and PEA, show promise for treatment of several neuropsychiatric disorders, including addiction. We previously showed that URB597, unlike THC and anandamide, is not rewarding in squirrel monkeys (Justinova et al., 2008). Here we assessed abuse liability of the FAAH inhibitor PF‐04457845, currently in clinical testing for treatment of cannabis withdrawal. In squirrel monkeys trained to self‐administer anandamide (FR10 schedule, 60‐s timeout), PF‐04457845 maintained higher numbers of self‐administered injections per session and higher rates of responding than vehicle at doses of 3 and 10 µg/kg/injection. The cannabinoid CB1 inverse agonist/antagonist rimonabant (0.3 mg/kg, i.m.) blocked self‐administration of the peak dose of PF‐04457845 (10 µg/kg/injection). In abstinent monkeys that had previously self‐administered THC, PF‐04457845 caused moderate reinstatement of drug‐seeking behavior over a narrow dose range. In rats, PF‐04457845, unlike URB597, significantly increased extracellular dopamine levels in the accumbens shell, but similarly to URB597 did not show THC‐like subjective effects. Thus, FAAH inhibitors can produce a spectrum of outcomes ranging from no evidence of rewarding, reinstatement or dopaminergic effects (URB597) to significant self‐administration, reinstatement and accumbal dopamine release (PF‐04457845).
Studies of the neurochemistry underlying swimming forces in Daphnia magna (839.8)
Authors: Sneed Raesean , Beckman Matthew
Published: June 2021

Daphnia magna are keystone species in freshwater lakes and ponds. Because they are consumed by fish in aquatic environments they are important to the health of freshwater bodies. Their ability to evade predation is central to their survival. Daphnids are also an emerging model organism in toxicogenomics and behavioral pharmacology. The major aim of this study is to understand the role that environmental temperature plays in shaping the neurochemistry underlying the maximum power stroke exerted by the second antennae—the mechanism for swimming in daphnids. In order to measure the forces produced by swimming daphnids we developed a low‐cost method for determining micronewton‐range swimming forces produced by tethered daphnids. To measure the power stroke, daphnids were tethered to custom‐made, calibrated force transducers composed of fine plastic filaments embedded in glass micropipettes held by a positioner. Two perspective video imaging was carried out to measure forces associated with swimming. Two populations of Daphnia magna were studied: one group was raised at 20°C and a second group was reared at 28°C. The data reveal an increase in the maximum power‐stroke among the daphnids raised at 28°C compared to 20°C. Further studies aim to delineate any neurochemical changes involved in this adaptation. These studies are providing insight into the role that environmental temperature plays in shaping the motor control and physiology of swimming behavior in Daphnia, a new model organism.

Grant Funding Source: Supported by The Augsburg McNair and NorthStar STEM Programs and the Eppley Foundation for Research
Etodolac, a racemic nonsteroidal anti‐inflammatory drug, exhibits low gastrointestinal toxicity: relation to the effects of the enantiomers (840.13)
Authors: Takeuchi Koji , Amagase Kikuko
Published: June 2021

Etodolac, a racemic (LR) nonsteroidal anti‐inflammatory drug (NSAID), has higher gastric safety compared to other conventional NSAIDs. However, it remains unknown whether the LR etodolac shows less adverse action in the small intestine. In the present study, we examined the effect of etodolac, both L/R and the enantiomers (S and R) on the gastric and small intestinal mucosa. Methods: Male SD rats were used. Etodolac (5‐50 mg/kg), both LR, S and R, was given p.o. in 18 h‐fasted or non‐fasted rats, and the stomach or the small intestine was examined for lesions 4 or 24 h later, respectively. Results: LR‐etodolac and S‐etodolac dose‐dependently caused lesions in both the stomach and small intestine, yet the effect of the former was much less potent compared to the latter. R‐etodolac did not cause damage even at 50 mg/kg. On the other hand, pretreatment with R‐etodolac dose‐dependently prevented the development of gastric lesions induced by indomethacin. The mucosal PGE2 content in the stomach and small intestine was significantly decreased by both LR‐etodolac and S‐etodolac, but not R‐etodolac. Conclusion: These results suggest that LR‐etodolac has less ulcerogenic properties in the gastrointestinal mucosa and showed that this safety profile of LR‐etodolac may be explained by the mucosal protective action of R‐etodolac.
Characterization of voltage‐operated and non‐voltage‐operated calcium channels in endothelin‐induced vasoconstriction of rat cerebral arteries (841.6)
Authors: Mamo Yohannes , Ziogas James , Soeding Paul , Angus James , Wright Christine
Published: June 2021

Endothelin‐1 (ET‐1) is a potential mediator of the pathogenesis of cerebral vasospasm. This study analysed the role of voltage‐operated calcium channels (VOCC) and non‐VOCC in ET‐1‐ induced vasoconstriction of rat cerebral arteries.

Rat isolated cerebral arteries (320‐430 µm i.d.) (anterior cerebral, middle cerebral, posterior communicating and basilar) were investigated using wire myography. ET‐1 concentration‐contraction response curves were constructed in arteries in calcium‐free medium or in the presence of nifedipine, NNC 55‐0396 or SK&F 96365 to inhibit the L‐type VOCC, T‐type VOCC and non‐VOCC, respectively. The ability of these antagonists to reverse the ET‐1‐induced contraction was also tested.

Neither inhibition of calcium channels nor removal of calcium altered the potency (pEC50) of ET‐1, but the maximum effects of ET‐1 (Emax) were variably attenuated. ET‐1 caused a small contraction (11‐22%) in calcium‐free solution. Nifedipine (1 µM) significantly decreased the Emax only in the middle cerebral artery, while NNC 55‐0396 (1 µM) and SK&F 96365 (30‐100 µM) attenuated the Emax in all cerebral arteries. Combination of nifedipine with SK&F 96365 more moderately decreased the Emax. Both nifedipine and SK&F 96365 reversed the ET‐1‐induced pre‐contraction in all arteries.

In conclusion, ET‐1 causes potent contraction by differentially activating both VOCC and non‐VOCC in rat cerebral arteries.
Rgs16 is an early marker of pancreatic ductal adenocarcinoma (842.7)
Authors: Ocal Ozhan , Heath Blake , Rivera Lee , Pashkov Victor , Swift Galvin , Brekken Rolf , Wilkie Thomas
Published: June 2021

Pancreatic ductal adenocarcinoma (PDA) is the fourth leading cause of cancer related deaths. Limited progress has been made in developing effective therapy for PDA. Compounding this challenge has been the lack of a systematic and robust in vivo screen for effective drug combinations. Kras mutations (e.g. KrasG12D) are found in over 90% of human PDA and occur early in tumor progression. Protein kinase and G‐Protein Coupled Receptor (GPCR) signaling can initiate Ras activation. Regulators of G‐protein Signaling (RGS) proteins are coincidence detectors that can be induced by and integrate multiple inputs to feedback regulate GPCR signaling. We previously described Rgs16 expression during embryonic and postnatal pancreas development in pancreatic progenitors, endocrine cells and ductal‐associated cells. Here, we show that the Rgs16::GFP transgene is a KrasG12D dependent marker of all stages of neoplasia in the p48Cre; LSL‐KrasG12D; Cdkn2af/f PDA mice. Although KrasG12D is expressed in embryonic pancreas progenitor cells and in all mature acinar cells, Rgs16::GFP expression in tumors first emerges in ductal Pancreatic Intraepithelial Neoplasms as early as 12 days post birth. The distribution and intensity of expression is proportional to and coincident with tumor burden. Rgs16::GFP expression in acinar cells of distal lobes initiates only after tumor occlusion of proximal ducts. The gene expression signature of primary PDA cells in culture obtained via RNA‐seq is closely related to embryonic progenitors of pancreatic ducts and endocrine cells. PDA cells in culture are highly sensitive to the chemotherapic drug gemcitabine mediated cell death. In a proof‐of‐principle for drug screens, we find PDA weanling mice treated with gemcitabine and Nab‐paclitaxel for two weeks have significantly lower Rgs16::GFP expression and reduced tumor size and occurrence. Rgs16::GFP is a novel in vivo reporter of PDA progression and sensitivity to new drug regimens that inhibit Kras mediated oncogenesis.

Grant Funding Source: Supported by NCI‐CA161624.
Ric‐8A deletion as tumor suppressor of oncogenic G‐protein alpha subunit alleles (842.8)
Authors: Patel Bharti , Tall Gregory
Published: June 2021

Constitutively‐active Q209L (QL) mutations in Gαq and Gα11 were found in 83% of human ocular melanomas. Ectopically expressed Gα11‐QL drove metastatic melanoma from xenografted melan‐a cells. No therapeutics target the melanoma‐driving mutant G proteins. Ric‐8A and Ric‐8B are molecular chaperones required for Gα subunit biosynthesis and maintenance of cellular Gαq/11 levels. Blocking Ric‐8A function may represent a viable means to attenuate the abundance of mutant, oncogenic G proteins. To test this, we created a Ric‐8A conditional knockout mouse. Homofloxed Ric‐8A mouse embryonic fibroblasts (MEFs) were isolated and transduced by lentivirus to express Cre‐recombinase and induce a Ric‐8A knockout (KO). Dramatic decreases in endogenous Gαi/o and Gαq/11 subunit levels were observed in Ric‐8A KO MEFs. Ric‐8A KO and control MEFs were examined for known cytotoxicity elicited by Gα11‐QL overexpression. Cell growth rates were measured and correlated to cytotoxic cell death measured by lactate dehydrogenase activity in culture media. Ric‐8A induced KO in MEFs reduced expressed Gα11‐QL levels and rescued cytotoxicity. To study the effect of Ric‐8A gene ablation on suppression of GNA11‐QL‐driven mouse melanoma, a Ric‐8A homofloxed mouse with melanocyte‐specific, tamoxifen‐inducible Cre‐recombinase was created. Inducible Ric‐8A KO melanocytes were immortalized and stably transduced with GNA11‐QL. Melanocytes will be xenografted in immunodeficient mice to induce Gα11‐QL driven melanoma. The efficacy of tamoxifen‐induced Ric‐8A deletion in injected melanocytes (or derived tumors) to inhibit the Gα11‐QL‐dependent melanoma will be examined. Tumor growth rates, metastases, and Kaplan‐Meier survival analyses will be presented. We anticipate that Ric‐8A KO‐dependent Gα abundance decrease will attenuate oncogenic Gα11‐QL driven melanoma and increase survival. Our work will establish the tenability of Ric‐8A as a potential drug target for disease caused by mutant G proteins.

Grant Funding Source: Supported by NIH grant RGM088242A
Identification of novel inhibitors of RGS6 through an alpha screen highthroughput campaign (843.14)
Authors: Bodle Christopher , Fisher Rory , Roman David
Published: June 2021

G Protein Coupled Receptors (GPCRs) are highly targeted proteins for drug discovery, with over 50% of all drugs on the market targeting these receptors. Regulator of G Protein Signaling (RGS) Proteins regulate the signaling cascade of GPCRs by accelerating the intrinsic GTPase activity of G protein alpha subunits and returning the heterotrimeric G protein to its inactive state. Larger RGS proteins can regulate a number of ancillary signaling cascades as well through additional biding motifs. RGS proteins have emerged as attractive targets for drug design, both by targeting their GTPase dependent and independent activity. RGS6 is one such RGS protein. RGS6 has been shown to be important in several disease states. Our lab employed alpha screen technology to identify novel inhibitors of RGS6 by screening for compounds which disrupt the protein:protein interaction between Gαo and the RH domain of RGS6. The RH domain of RGS6 was purified largely as described previously, and its activity was determined via a Malachite Green free phosphate detection assay. Assay robustness was determined resulting in a z‐score of 0.60. The screen yielded 5 compounds which inhibited the RGS6 RH : Gαo interaction at greater than 40%. Dose response curves were determined which resulted in three compounds with double‐digit micromolar IC50’s.
Sigma receptors mitigate Aβ‐potentiated calcium dysfunction during ischemia (846.7)
Authors: Behensky Adam , Cuevas Javier
Published: June 2021

Stroke is the second cause of death and the leading cause of serious long‐term disability. Ischemic stroke often overlaps with diseases involving amyloid‐β (Aβ), such as Alzheimer’s and cerebral amyloid angiopathy. These comorbidities lead to potentiated responses that ultimately result in vascular dementia. The mechanism(s) contributing to this potentiation remain poorly understood. One key player in the pathobiology of stroke and Aβ toxicity is the dysregulation of intracellular calcium ([Ca2+]i) homeostasis. Experiments were carried out to determine if application of A affects the [Ca2+]i overload produced by in vitro ischemia in isolated cortical neurons. Aβ potentiated neuronal increases in [Ca2+]i following ischemia in a manner suggesting that acid‐sensing ion channels, known to promote neurodegeneration, are being functionally upregulated under these conditions. Moreover, our results showed that activation of the neuroprotective sigma (σ) receptors abolished this enhancement of [Ca2+]i overload. This preservation in Ca2+ homeostasis leads to an increase in neuronal viability. Our data give insight into a putative mechanism promoting injury when ischemia occurs in the presence of A and identify σ receptors as potential mechanism for reducing injury under these conditions.
Metabolic control points in cancer (85.3)
Authors: Jones Russell , Faubert Brandon , Dupuy Fanny , Izreig Said , Boily Gino , Griss Takla , Samborska Bozena , Siegel Peter
Published: June 2021

All cells must manage their energetic resources to survive. This is particularly true for cancer cells, which initiate changes in their cellular metabolism as they transition from a normal to a cancerous state. Tumor cells must engage pathways of cellular metabolism to generate the energy and biosynthetic intermediates required to support increased cell growth and division. In addition, for growing tumours, overcoming metabolic stress induced by nutrient limitation and/or hypoxia is a critical step for solid tumour growth. It is now appreciated that many of the predominant mutations observed in cancer also influence tumor metabolism as part of their mode of action. Here I discuss the role that cellular energy sensors ‐ notably the Liver Kinase‐B1 (LKB1) and the AMP‐activated protein kinase (AMPK) ‐ play in regulating tumor metabolism and adaptation to metabolic stress. We have found that the LKB1‐AMPK pathway negatively regulates aerobic glycolysis (the “Warburg effect”) in cancer cells, and that disruption of this pathway promotes a metabolic shift to aerobic glycolysis and supports increased cell growth. This metabolic shift is mediated by the hypoxia‐inducible factor‐1α (HIF‐1α), and silencing HIF‐1α reverses the biosynthetic and proliferative advantages conferred by reduced LKB1‐AMPK signaling. Finally, I will present evidence that AMPK activity is dynamically regulated in tumors to enhance pro‐growth metabolism, but that this pathway is required to maintain tumor cell viability in response to stress. Finally, I will discuss whether metabolic checkpoints serve “suppressive” or “supportive” roles in cancer development and/or progression.

This work was supported by grants from the CIHR (MOP‐93799) and CCSRI (700586).
Cyclic AMP reverses the pro‐fibrogenic phenotype of cardiac myofibroblasts (850.3)
Authors: Aroonsakool Nakon , Yokoyama Utako , Lu David , Patel Hemal , Insel Paul
Published: June 2021

Previous data have shown that increased cellular levels of cyclic AMP (cAMP) can prevent the transformation of cardiac fibroblast (CFs) into pro‐fibrogenic myofibroblasts (MyoFbs), a transformation that precedes increased extracellular matrix deposition and cardiac fibrosis. We have now investigated two additional roles for cAMP: 1) contribution to the MyoFb phenotype and 2) reversal of the MyoFb phenotype. We found that MyoFbs have lower cAMP content than do CFs, and in addition, have decreased mRNA and protein expression of isoforms of adenylyl cyclase (AC), including AC5 and AC6, the two major AC isoforms, and increased expression of several phosphodiesterase isoforms. Incubation of primary isolates of adult rat CFs with a pro‐fibrotic stimulus, TGFβ1 (10ng/mL, 48hr), prominently increases mRNA and protein expression of collagen Iα1, Iα2, III, α‐smooth muscle actin, plasminogen activator inhibitor‐1 and cellular contractile state. All these hallmarks of the fibrogenic state were reversed in MyoFbs incubated with 10µM forskolin (a direct AC activator). Furthermore, incubation with N6‐Phe‐cAMP (a PKA selective analog) also reversed the pro‐fibrogenic state. We conclude that MyoFbs have a lower level of cAMP and that increasing cAMP content can reverse their pro‐fibrotic state. Approaches to increase cAMP in MyoFbs may provide a means to treat cardiac fibrosis.

Grant Funding Source: NIH
Cardiac myocyte‐specific overexpression of caveolin‐3 enhances β‐adrenergic signaling and response in young and aged mice (850.8)
Authors: Busija Anna , Roth David , Insel Paul , Patel Hemal
Published: June 2021

Caveolins (Cavs) are scaffolding proteins essential to the formation of caveolae, membrane domains that compartmentalize numerous signaling molecules, including β‐adrenergic receptors (β‐ARs). A decrease in Cav proteins with aging may contribute to age‐associated loss in cardiac function. By contrast, mice with cardiac myocyte (CM)‐specific overexpression of Cav‐3 (Cav‐3 OE) have more caveolae in CMs and are protected from age‐associated cardiovascular dysfunction. β‐AR agonists increase inotropy and chronotropy but whether increased Cav‐3 expression alters β‐AR response as a means to preserve cardiovascular function with age is unknown. We treated Langendorff‐perfused hearts from young and aged transgene‐negative (TGneg) and Cav‐3 OE mice with the β‐AR agonist isoproterenol (Iso). Cav‐3 OE mice had augmented Iso‐stimulated inotropy (+dP/dt) and lusitropy (‐dP/dt) relative to TGneg, and CMs isolated from Cav‐3 OE mice have increased cAMP production and phospholamban phosphorylation in response to Iso. Moreover, aged (20‐22 month‐old) Cav‐3 OE mice have preserved β‐AR‐stimulated inotropy and lusitropy compared to age‐matched TGneg mice. Thus, increased expression of Cav‐3 enhances β‐AR‐promoted contractile function in both young and aged mice. Increase in Cav‐3 expression may be a way to enhance cardiac β‐AR response throughout the life span.

Grant Funding Source: Supported by NIH HL107200
Coronary endothelial dysfunction induced by Nlrp3 inflammasome activation during hypercholesterolemia: beyond inflammation (851.13)
Authors: Zhang Yang , Li Xiang , Pitzer Ashley , Li Pin‐Lan
Published: June 2021

Recent studies have shown that Nlrp3 inflammasomes function as a major intracellular molecular machinery to switch on the inflammatory response upon sensing danger signals such as elevated plasma levels of cholesterol during hypercholesterolemia (HC). The present study tested the hypothesis that endothelial Nlrp3 inflammasome activation has uncanonical direct actions on endothelial cells (ECs) producing endothelial dysfunction prior to or during inflammation, which contribute to vascular injury at early stages of atherogenesis. Endothelial dysfunction was assessed by evaluating endothelium‐dependent vasodilation (EDVD) in isolated, perfused and pressurized coronary arteries in response to bradykinin and acetylcholine. HC induced by poloxamer 407 impaired EDVD in Nlrp3+/+ mice, which was markedly ameliorated in Nlrp3‐/‐ mice. Pretreatment of coronary arteries with inflammasome products showed that IL‐1β or HMGB1 impaired EDVD in normal Nlrp3+/+ mice suggesting a detrimental effect of IL‐1β or HMGB1 on the endothelium. In contrast, HC‐induced impairment of EDVD in Nlrp3+/+ mice was attenuated when these mice were treated with caspase‐1 inhibitor WEHD or HMGB1 inhibitor glycyrrhizin, but not with IL‐1β receptor antagonist. Confocal microscopic analysis demonstrated that in Nlrp3+/+ mice, HC increased caspase‐1 activity and HMGB1 expression in coronary arterial endothelium, but did not alter the levels of IL‐1β or Mϕ marker F4/80. In cultured ECs, cholesterol crystals (CCs) activated Nlrp3 inflammasomes and increased caspase‐1 activity. Further, CCs impaired EDVD in coronary arteries from Nlrp3+/+ mice, but not in Nlrp3‐/‐ mice. Taken together, these results suggest that activation of endothelial Nlrp3 inflammasomes directly impair endothelial function beyond its canonical inflammatory effects such as Mϕ recruitment and T‐cell infiltration. This non‐inflammatory action of Nlrp3 inflammasome activation may initiate or exacerbate vascular injury during HC.

Grant Funding Source: Supported by NIH grants HL057244, HL091464 and HL075316
Cardiovagal baroreflex sensitivity is improved in children with high blood pressure after a psychosocial intervention (852.1)
Authors: Klassen Stephen , Chirico Daniele , Hood Colleen , Wade Terrance , Cairney John , O'Leary Deborah
Published: June 2021

The aim of this study was to assess the effectiveness of a Leisure and Well‐Being Model (LWM) psychosocial intervention on blood pressure (BP) regulation in children. Children with consistent BP 蠅 95th percentile and <90th percentile were grouped into high (HBP) and normal blood pressure (NBP) groups, respectively. Anthropometric data were collected along with five minutes of supine beat‐by‐beat BP and R–R interval. High frequency (HF; 0.15‐0.5 Hz) and low frequency (LF; 0.05‐0.15 Hz) power spectral indices were computed and transfer function analysis for the LF region was used to calculate baroreflex sensitivity (BRS). Pre and post‐test measures were taken one year apart. Results from 60 children (43 NBP, 17 HBP) indicated a three‐way interaction between intervention, BP status (NBP or HBP) and time (year 1 to year 2) independent of BMI (p=0.036). HBP participants receiving the intervention demonstrated an improvement in BRS from year 1 (11.4 ± 5.4 ms/mmHg) to year 2 (17.4 ± 8.5 ms/mmHg) compared to the HBP participants that did not receive the intervention (15.3 ± 8.5 ms/mmHg to 13.4 ± 6.5 ms/mmHg). These findings demonstrate that a LWM psychosocial intervention had a positive impact on BP regulation in children with elevated BP. These findings provide evidence of the importance of psychosocial determinants on autonomic regulation of BP in children.

Grant Funding Source: Heart and Stroke Foundation of Ontario
Cerebral oxidative metabolism during exhaustive exercise and recovery at sea level and high altitude (853.12)
Authors: Smith Kurt , Macleod David , Willie Christopher , Lewis Nia , Tymko Mike , Macleod Nicholas , Ikeda Keita , Day Trevor , Ainslie Philip
Published: June 2021

Cerebral oxidative carbohydrate metabolism (OCI) is reduced during moderate and exhaustive exercise at sea‐level (SL) and restored rapidly during recovery. In contrast, in normobaric hypoxia OCI remains unchanged at rest and during moderate exercise. It is unknown what happens to OCI during exhaustive exercise and recovery following partial acclimatization to high altitude (HA; 5050m). Therefore, we hypothesized that OCI will be reduced at HA compared with SL during rest, exercise and recovery. Cerebral metabolism was calculated from the arterial and jugular venous differences for oxygen (Ca‐vO2), glucose (Glua‐v), and lactate (Laca‐v) at 20,40,60,80,100% of the maximum achieved wattage (%Wmax) and during 1,2,4,6,8,10,15,20,25, and 30 minutes of recovery at both SL and HA. The OCI was calculated as an index of the cerebral molar carbohydrate uptake ratio: OCI = Ca‐vO2/Glua‐v + ½ Laca‐v. Resting OCI at HA was ~40% reduced compared with SL (4.0 ± 0.5 vs 6.7±1.0 µmol.100g‐1.min‐1, respectively). Compared to SL, exercise at HA resulted in an ~14, and 8% greater reduction in OCI from rest at 20 and 40%Wmax, an equal reduction at 60% Wmax and an ~ 25, and 29% lesser reduction at 80, and 100% Wmax. During recovery from exercise at SL, OCI remained below baseline values until 25 min whereas at HA the OCI return to baseline at 6 min. It appears that during exhaustive exercise and recovery at sea level the brain relies more on non‐oxidative metabolism than at high altitude.

Grant Funding Source: Canadian Graham‐Bell Scholarship, National Science and Engineering Research Council
An anatomical basis for interaction between acid‐sensing ion channel 1 and neuronal nitric oxide synthase in rat and human cerebral arteries (853.8)
Authors: Lin Li‐Hsien , Jin Jingwen , Nashelsky Marcus , Dailey Morris , Talman William
Published: June 2021

Acid‐sensing ion channel type 1 (ASIC1), which may play contribute to synaptic plasticity, memory, fear conditioning and ischemic brain injury, is found primarily in brain; but it is also expressed in isolated mouse cerebrovascular smooth muscle cells. However, ASIC1 has not been shown in intact cerebral arteries. In contrast, neuronal nitric oxide synthase (nNOS), which is responsible for synthesis of NO, is found in human and animal cerebral arteries where NO may modulate protein activity. In that NO also modulates proton‐gated currents in cultured cells expressing ASIC1, we hypothesized that ASIC1 and nNOS may be expressed in close proximity in cerebral arteries. By Western blot analysis we found that ASIC1 is expressed in cerebral arteries in rat and human. Using confocal microscopy we found that ASIC1‐immunoreactivity (IR) was present in the anterior cerebral artery (ACA), middle cerebral artery (MCA), posterior cerebral artery (PCA) and basilar artery (BA) of rat and human. Colocalization of ASIC1‐IR with IR of alpha‐smooth muscle actin confirmed that ASIC1 was located in the smooth muscle layer of cerebral arteries while nNOS‐IR was found in neighboring endothelial and adventitial layers of the ACA, MCA, PCA and BA in rat and human. The proximity of ASIC1‐IR and nNOS‐IR provides an anatomical basis for possible interactions between ASIC1 and nNOS in regulating vasomotor tone of cerebral arteries.

Grant Funding Source: Supported by NIH RO1 HL 088090 and a VA Merit Review
Heme oxygenase‐1 counteracts contrast media‐induced endothelial cell dysfunction (855.1)
Authors: Chang Chao‐Fu , Liu Xiao‐ming , Peyton Kelly , Durante William
Published: June 2021

Endothelial cell (EC) dysfunction contributes to the pathogenesis of contrast media (CM)‐induced acute kidney injury, which is a major adverse event following coronary angiography. In this study, we evaluated the effect of CM on human EC proliferation, migration, and inflammation, and determined if heme oxygenase‐1 (HO‐1) influences the biological actions of CM. We found that three distinct iodine‐based CM, including high‐osmolar (diatrizoate), low‐osmolar (iopamidol), and iso‐osmolar (iodixanol), stimulated the expression of HO‐1 protein and mRNA. The induction of HO‐1 was dependent on the concentration and duration of CM exposure and associated with an increase in NF‐E2‐related factor‐2 (Nrf2) activity and reactive oxygen species (ROS) production. CM also stimulated HO‐1 promoter activity and this was prevented by mutating the antioxidant responsive element or by overexpressing dominant‐negative Nrf2. In addition, the CM‐mediated induction of HO‐1 and activation of Nrf2 was abolished by N‐acetyl‐L‐cysteine. Finally, CM inhibited the proliferation and migration of ECs and stimulated the expression of intercellular adhesion molecule‐1 and the adhesion of monocytes on ECs. Inhibition or silencing of HO‐1 exacerbated the anti‐proliferative and inflammatory actions of CM but had no effect on the anti‐migratory effect. In conclusion, the present study demonstrates that the induction of HO‐1 via the ROS‐Nrf2 pathway counteracts the anti‐proliferative and inflammatory actions of CM. Therapeutic approaches targeting HO‐1 may provide a promising approach in preventing CM‐induced endothelial and organ dysfunction.

Grant Funding Source: Supported by NIH grant HL59976 and a grant from the Department of Health, Taipei City Government
Comparison of the antihypertensive response to selective afferent versus total renal nerve ablation in “early phase” hypertension in the Dahl salt‐sensitive rat (856.3)
Authors: Foss Jason , Osborn John
Published: June 2021

Similar to humans, renal denervation (RDNX) attenuates hypertension (HT) in the Dahl salt‐sensitive (DS) rat, yet it is unclear whether this effect is due to ablation of afferent or efferent renal nerves (or both). The present study tested the hypothesis that the antihypertensive effect of RDNX in the early phase (3 weeks of high salt diet) of DS HT is due to ablation of afferent renal nerves, specifically. DS rats on a low salt diet (0.1% NaCl) were instrumented for telemetric measurement of arterial pressure (AP) and heart rate (HR), and housed in metabolic cages for measurement of Na+ and H2O balance. Following a baseline period, rats were fed a 4% NaCl diet for the remainder of the protocol. After 3 weeks of 4% salt, rats underwent SHAM surgery (n = 10), RDNX (n = 10) or selective ablation of afferent renal nerves by periaxonal capsaicin (renal‐CAP; n = 10). 4 weeks later, rats were sacrificed and kidneys were harvested to confirm efferent (renal NE) and afferent (renal CGRP) denervation. Following treatment, AP continued to increase in all groups and, on the final day, was similar in SHAM (162 ± 5 mmHg) and renal‐CAP (160 ± 4 mmHg) rats (p>0.05), but was significantly lower in RDNX (150 ± 3 mmHg) rats (p<0.05). There were no differences between groups in any other parameter. These results suggest that the antihypertensive effect of RDNX in the early phase of DS HT is due to the ablation of efferent rather than afferent renal nerves.
BK channel β‐1 subunit deficiency exaggerates vascular fibrosis and organ damage in high fat diet‐induced obesity in mice (857.10)
Authors: Xu Hui , Garver Hannah , Phelps Jeremiah , Fernandez Roxanne , Galligan James , Fink Gregory
Published: June 2021

BK channels regulate arterial tone. Studies done in humans and animals suggest that impaired BK channel function contributes to obesity associated hypertension due to higher myogenic tone and increased norepinephrine (NE) reactivity. In current study, we continually measured mean arterial pressure (MAP) and heart rate (HR) using radiotelemetry in high fat (HF) diet fed wild type (WT) and BK channel β1‐subunit knockout (BK β1‐KO) mice during last 11 weeks of HF‐fed. After 24 weeks on HF‐fed, body weight and blood glucose levels were similar in all mice. All mice were normotensive, but BK β1‐KO mice showed a progressive fall in HR when compared to WT mice. Atenolol (oral) or hexamethonium (ip) treatment reduced MAP and HR similarly in all mice, prazosin (oral) decreased MAP and increased HR in BK β1‐KO only. Mesenteric arteries (MA) from BK β1‐KO mice exhibited increased sensitivity to NE and BayK 8644, higher myogenic tone, increased wall thickness and smaller wall/lumen ratio compared to WT mice. BK β1‐KO mice also exhibited left ventricular hypertrophy, lower hematocrits and higher plasma creatinine levels than WT mice. Histological studies revealed more extensive collagen deposition in MA, coronary and renal arteries, myocardium and kidneys of BK β1‐KO compared to WT mice. Our results indicate that BK channel deficiency does not cause hypertension, but does promote vascular fibrosis and organ damage in HF‐fed mice.

Grant Funding Source: Supported by NIH and AHA
Novel role of HIF‐1alpha in tubular Na transport in the remnant kidney (860.7)
Authors: Singh Prabhleen , Ayoyama Koji , Pham Hai , Thomson Scott
Published: June 2021

Remnant nephrons after subtotal nephrectomy (STN) show significant hyperfiltration. We have also shown increased oxygen consumption for tubular Na reabsorption in STN leading to hypoxia. We hypothesized that this increase may be due to a relative shift in Na transport to nephron segments distal to the proximal tubule, where oxygen costs for Na transport are higher. In STN kidney, activation of HIF‐1α, master regulator of cell response to hypoxia, lowers the elevated oxygen consumption. Hence, we also examined the effect of HIF‐1α on Na transport in different nephron segments.

In the STN kidney, when adjusted for SNGFR, proximal reabsorption was lower in STN (p=0.01), and the early distal flow rate was nearly double that in shams. This was accompanied by a reduced expression of Na/H exchanger (NHE3) in the proximal tubule (p<0.05), while the expression of Na‐Cl cotransporter (NCC) in the distal tubule was increased (p<0.05). In micropuncture experiments, SNGFRs were found to be higher in STN treated with DMOG, a pharmacological HIF‐1α activator, compared to untreated STN (67±4 vs. 50±4 nl/min, p=0.01), as were the APRs (25±2 vs. 20±2 nl/min, p=0.09), but the fractional reabsorption was modestly lower (0.37 vs. 0.4). This suggests a mild effect of HIF‐1α induction on proximal reabsorption. Moreover, DMOG lowered the NHE3 expression in controls but did not have a significant effect in the STN, but significantly lowered the NCC expression in both controls and STN kidney (p<0.05). Alteration in Na transport in the thick limbs and distal tubules along with expression of NKCC2 and ENaC are currently being performed.

These data suggest that there is relative shift in Na transport to the distal segments of the nephron in early STN, which increases renal oxygen consumption required for Na transport. HIF‐1α activation improves kidney oxygen consumption by lowering Na transport in these segments, thus demonstrating a novel role of HIF‐1α in regulation of the coupling between tubular transport and metabolism.

Grant Funding Source: NIH
Influence of late N‐acetylcysteine administration on cardiac remodeling in long‐term follow‐up postinfarction rats (862.3)
Authors: Lopes V , Oliveira Junior S , Cezar M , Damatto R , Bonomo C , Pagan L , Lima A , Gomes M , Zornoff L , Okoshi K , Okoshi M , Martinez P
Published: June 2021

This study aimed to evaluate the influence of late N‐acetylcysteine (NAC) administration on cardiac remodeling in long‐term follow‐up postinfarction rats. Methods: Myocardial infarction (MI) was induced by left coronary occlusion. Four months later, rats were assigned to three groups: Sham (n=13), MI‐C (MI without treatment, n=16), and MI‐NAC (MI treated with N‐acetylcysteine, 120 mg/kg/day, n=16). Six months after surgery, cardiac structures and function were evaluated by transthoracic Doppler echocardiogram and rats were euthanized the next day. Infarct size was measured by histological analysis, and rats with small MI (< 30%) were excluded. Results: MI size did not differ between MI‐C and MI‐NAC groups (p>0.05; Student’s t test). Right ventricle (RV) and lung weight, RV/body weight (BW) and lung/BW ratios were similar between MI‐C and MI‐NAC and higher than Sham. Left ventricle diastolic diameter, left atrium (LA) diameter, and LA/BW ratio were higher in MI‐C than Sham and similar between MI‐C and MI‐NAC. The systolic function variables fractional area shortening and posterior wall shortening velocity were similar between MI‐C and MI‐NAC and both lower than Sham. Concerning diastolic function, E wave‐to‐A wave ratio was higher in MI‐C than in both Sham and MI‐NAC (Sham: 1.47±0.14; MI‐C: 4.83±2.41; MI‐NAC: 3.25±1.85; p<0.001, ANOVA and Bonferroni). Conclusion: Late N‐acetylcysteine treatment attenuates diastolic dysfunction in long‐term follow‐up postinfarction rats.

Grant Funding Source: FAPESP and CNPq