bluuebunny/crossref_metadata_2025 huggingface dataset:
Interindividual Variation in Sunitinib Metabolism in Primary Human Hepatocytes
Authors: Abouda Arsany A. , Bissada Jennifer E. , Jackson Klarissa D.
Published: June 2021

Sunitinib is a multitargeted tyrosine kinase inhibitor associated with idiosyncratic hepatotoxicity. The mechanisms of this toxicity are unknown. Sunitinib is metabolized primarily by cytochrome P450 (CYP) 3A4/5 to form the major active metabolite N‐desethylsunitinib (M1). Recent studies from our lab have also shown that sunitinib undergoes oxidative defluorination via CYP1A and CYP3A enzymes to form a chemically reactive, potentially toxic quinoneimine metabolite. We hypothesized that P450 genetic variations contribute to individual differences in sunitinib metabolism and bioactivation, which may play a role in development of sunitinib‐induced hepatotoxicity. The purpose of this study was to characterize the metabolism of sunitinib in CYP3A5‐genotyped primary human hepatocytes, and evaluate the influence of genetic variation and other individual factors on metabolite formation. Commercially available human hepatocytes from individual donors were purchased from BioIVT. CYP3A5 genotype and P450 enzyme activities for each donor were provided by the company. Donor genotypes were reported as: CYP3A5*1/*1, CYP3A5*1/*3, and CYP3A5*3/*3. Sunitinib (10 uM) was incubated with the hepatocytes in suspension for 2 h, and drug metabolites were analyzed by liquid chromatography‐tandem mass spectrometry. In experiments with individual genotyped hepatocytes, M1 formation varied 13.5‐fold between donors but did not significantly differ by CYP3A5genotype. However, M1 formation was significantly higher in female donors compared to male donors. Generation of defluorinated sunitinib (M3) varied 5.6‐fold between donors but did not significantly differ by CYP3A5genotype or sex. These results suggest that donor sex, but not CYP3A5genotype, may influence the metabolism of sunitinib to the major metabolite M1. Additional studies are needed to identify the individual factors that impact the bioactivation of sunitinib to form the reactive quinoneimine product. Studies are currently underway to determine the relationship between P450 enzyme activity and sunitinib metabolite formation in individual human hepatocytes.

Support or Funding Information

This research was supported by the American Association of Colleges of Pharmacy, Lipscomb University College of Pharmacy and Health Sciences, and the National Cancer Institute of the National Institutes of Health (K01CA190711). Research reported here is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Intestinal HIF‐1α Deletion Exacerbates Alcoholic Liver Disease through Inducing Intestinal Dysbiosis and Barrier Dysfunction
Authors: Feng Wenke
Published: June 2021

Objectives

Alcoholic liver disease (ALD) is characterized by gut dysbiosis and increased gut permeability. Hypoxia Induced Factor 1α (HIF‐1α) has been implicated in transcriptional regulation of intestinal barrier integrity and inflammation. We aimed to test the hypothesis that HIF‐1α plays a critical role in gut microbiota homeostasis and the maintenance of intestinal barrier integrity in a mouse model of ALD.

Methods

Wide type (WT) and intestinal epithelial‐specific HIF‐1α knockout mice (IEhif‐1α−/−) were pair‐fed modified Lieber‐DeCarli liquid diet containing 5% (w/v) alcohol or isocaloric maltose dextrin for 24 days. Serum levels of ALT and endotoxin were determined. Fecal microbiota were assessed. Liver steatosis and injury, and intestinal barrier integrity were evaluated.

Results

Alcohol feeding increased serum levels of ALT and LPS, hepatic triglyceride concentration, and liver injury in the WT mice. These deleterious effects were exaggerated in IEhif‐1α−/− mice. Alcohol exposure resulted in greater reduction of the expression of intestinal epithelial tight junction proteins, claudin‐1 and occludin, in IEhif‐1α−/− mice. In addition, cathelicidin‐related antimicrobial peptide (CRAMP) and intestinal trefoil factor (ITF) were further decreased by alcohol in IEhif‐1α−/− mice. Metagenomic analysis showed an increased gut dysbiosis with a significantly decreased firmicutes/bacteroidetes ratio in IEhif‐1α−/− mice compared to the WT mice exposed to alcohol. An increased abundance of Akkermansia and a decreased level of Lactobacillus in IEhif‐1α−/− mice were observed. Non‐absorbable antibiotics treatment reversed the liver steatosis in both WT and IEhif‐1α−/− mice.

Conclusion

Intestinal HIF‐1α is essential for the adaptation response to alcohol exposure‐induced changes in intestinal microbiota and barrier function associated with elevated endotoxemia and hepatic steatosis and injury.

Support or Funding Information

NIH

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Bypassing Major Venous Occlusion and Duodenal Lesions in Rats, and Therapy with the Stable Gastric Pentadecapeptide BPC 157, L‐NAME and L‐arginine
Authors: Amic Fedor , Drmic Domagoj , Krezic Ivan , Zizek Helena , Peklic Marina , Klicek Robert , Pajtak Alen , Amic Enio , Perisa Marija Milkovic , Tvrdeic Ante , Blagaic Alenka Boban , Seiwerth Sven , Sikiric Predrag
Published: June 2021

Background

Up to now, application of, prototype cytoprotective agent BPC 157 induced bypassing of occlusion, in rats underwent vessels occlusions, through rapid collaterals presentation.

Aims

To show that duodenal lesions induced by major venous occlusion can be attenuated by BPC 157, prototype cytoprotective agent, regardless NO system involvement.

Methods

In rats underwent superior anterior pancreaticoduodenal vein (SPDAV)‐ligation, medication was bath at the ligated SAPDV (BPC 157 10 ug, 10 ng/kg/1ml bath/rat; L‐NAME 5 mg/kg/1ml bath/rat; L‐arginine 100 mg/kg/1ml bath/rat, alone and/or together; or BPC 157 10 ug/kg instilled into rat stomach, at 1 min ligation‐time.

Results

Unlike severe course in controls, after BPC 157 application, rats commonly exhibited strong attenuation of mucosal lesion and serosal congestion, improved vessels presentation, much more interconnections, branching raised more than 60% from the initial value; inferior anterior pancreaticoduodenal vein (IAPDV) and superior mesenteric vein (SMV) were both non congested. Interestingly, while at 5 min and 30 min period alone L‐NAME and L‐arginine decreased mucosal and serosal duodenal lesions, their effect was worsening at 24 h period, no effect on the vessels collaterals and branching. Together, L‐NAME+L‐arginine antagonized each other response at any point, and thus, NO‐related effect. With BPC 157 all SAPDV‐ligated rats receiving L‐NAME and/or L‐arginine appear like rats treated with BPC 157 alone.

Conclusions

BPC 157, rapidly bypassing occlusion, rescued original duodenal flow through IAPDV to SMV flow, NO‐system related effect.

Support or Funding Information

This work was supported by the Ministry of Science, Education and Sports, Republic of Croatia [grant number 108‐1083570‐3635].

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Development of a TRPA1 Reporter Mouse Model
Authors: Kim Seol‐Hee , Bahia Parmvir , Taylor‐Clark Thomas
Published: June 2021

Transient Receptor Potential Ankyrin 1 (TRPA1) is an ion channel which is activated by environmental irritants (e.g. formaldehyde and acrolein) and pungent stimuli such as mustard oil, garlic and cinnamaldehyde. TRPA1 is known to be expressed in a subset of nociceptive sensory afferent and thus, playing an important role in defensive reflexes. However, TRPA1 has also been implicated in fibroblast, epithelial cell and smooth muscle cell function, thus it is not entirely clear the extent to which TRPA1 function is restricted to sensory neurobiology.

In the current study, we used the Flp‐FRT (flipase‐flipase recognition target) system to generate a TRPA1 reporter mouse model. We generated a TRPA1‐Flp knockin stain which incorporated Flpo after the last endogenous TRPA1 exon. Expression of Flpo was linked to the expression of endogenous TRPA1 via a 2A sequence. The TRPA1‐Flp was crossed with a tdTomato reporter strain carrying frt‐flanked STOP condon (RC::FLTG) to generate a mouse model (Flp::RC) that expresses red fluorescent protein tdTomato in TRPA1 expressing cells. Vagal sensory ganglia were collected from those animals and used for characterization. First, the vagal ganglia were cryosectioned and immunostained to determine nociceptive subtypes using anti‐TRPV1 antibody. Second, primary neurons were isolated from the vagal ganglia and used to monitor calcium influx changes after stimulation with allyl isothiocyanate (AITC), the TRPA1 agonist.

tdTomato was expressed in a subset of vagal ganglion neurons, but not in other cell types within the ganglion. The majority of the red fluorescent cells were TRPV1 positive cells and approximately 30% of TRPV1 positive cells co‐expressed TRPA1. In our functional studies, a total of 58 dissociated vagal neurons were assayed and 17 cells expressed tdTomato. Among the tdTomato expressing cells, 11 cells responded to 100 μM AITC. Additionally, 9 cells responded to AITC from 41 of non‐tdtomato expressing cells. Overall, our data suggests that the transgenic mouse model generated using Flp‐FRT system successfully labeled TRPA1 cells. Our preliminary findings suggest that the TRPA1 Flp::RC strain can be utilized in investigations involving TRPA1 ion channel physiology.

Support or Funding Information

This study is funded by National Institutes of Health Common Fund SPARC OT2 (2016–2019): “Functional mapping of peripheral and central circuits for airway protection and breathing”

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Development of Distal Nephron Diuretics Targeting Heteromeric Kir4.1/5.1 Potassium Channels
Authors: Kharade Sujay V. , Kramer Meghan , Denton Jerod S.
Published: June 2021

Edema is a life‐threatening clinical problem in patients with congestive heart failure (HF) and chronic kidney disease (CKD). Loop diuretics are often prescribed as a first‐line therapy, but the development of loop diuretic resistance can limit the efficacy of these drugs for managing extracellular fluid volume load. A rapidly emerging body of genetic data from rodents and humans has implicated heteromeric inward rectifier potassium (Kir) channels comprised of Kir4.1 (KCNJ10) and Kir5.1 (KCNJ16) as molecular targets for a novel class of diuretics that could potentially be used to circumvent loop diuretic resistance. These channels are prominently expressed on the basolateral membrane of the distal convoluted tubule, where they participate in potassium sensing, regulation of WNK‐SPAK kinase signaling, and sodium reabsorption via the sodium‐chloride co‐transporter, NCC. Homotetrameric Kir4.1 channels are also expressed in the distal nephron; however, they comprise a minor population compared to more prevalent Kir4.1/5.1 heteromeric channels. We recently reported on the discovery of a Kir4.1 channel inhibitor, termed VU0134992, that despite its 10‐fold selectivity for Kir4.1 over Kir4.1/5.1 channels, induces diuresis, natriuresis, and kaliuresis following oral administration in rats (Kharade et al., 2018). This proof‐of‐concept data supports the notion that renal Kir4.1‐containing channels represent “druggable” targets for managing edema in HF and CKD patients. To develop selective inhibitors for probing the therapeutic potential of Kir4.1/5.1 channels, we established a fluorescence‐based, thallium flux assay for interrogating large compound libraries with high‐throughput screening (HTS). The assay was developed using stably transfected Kir4.1/5.1 cell line, is performed in 384‐well plates, and was validated for HTS by meeting a series of rigorous performance benchmarks. In a pilot screen of 6,429 compounds tested at 10 μM, we identified 29 putative inhibitors (0.5% hit rate). We are currently retesting these compounds for activity toward Kir4.1/5.1 and related Kir channels. This work should lead to the development of potent and specific small‐molecule tool compounds for exploring the integrative physiology and therapeutic potential of Kir4.1/5.1 for the treatment of hypertension and edema.

Support or Funding Information

Funding NIH R01 DK082884 and 5R21 NS073097‐01S1 to J.S.D.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Inhibition of AT2R and BK2R attenuates the effect of high K intake (HK) on thiazide‐sensitive Na‐Cl cotransporter
Authors: Zhang Dandan , Gu Li , Wu Peng , Gao Zhongxizi , Gu Ruimin , Lin Daohong , Wang Wenhui
Published: June 2021

The basolateral K channel composed of Kir4.1/Kir5.1 in the distal convoluted tubule (DCT) plays a key role in mediating the inhibitory effect of high dietary K (HK) intake on NCC activity by inhibiting the basolateral K conductance and depolarizing DCT membrane potential. Previous studies have demonstrated that the stimulation of type II angiotensin II receptor (AT2R) or bradykinin type II receptor (BK2R) inhibited the basolateral K channels in the DCT. Furthermore, the inhibition of AT2R or BK2R impairs renal K excretion by stimulating the expression of total NCC (tNCC) and phorsphor‐NCC (pNCC). This effect was induced by stimulation of the basolateral K channels because neither PD123319 (AT2R antagonist) nor HOE140 (BK2R antagonist) had a significant effect on NCC in kidney‐specific Kir4.1 knockout mice (Ks‐Kir4.1 KO). The aim of the present study is to test whether the activation of both AT2R and BK2R are required for mediating the effect of HK intake on the basolateral K channels and NCC. Feeding mice (male and female) with HK diet (2% or 10%) for overnight significantly decreased the basolateral K conductance, depolarized the DCT membrane, diminished the expression of pNCC and tNCC and decreased thiazide‐sensitive natriuresis. The deletion of Kir4.1 not only decreases the NCC activity but also abolishes the effect of overnight‐HK diet on NCC. Pretreatment of the mice with PD123319 and HOE140 stimulates the expression of both tNCC and pNCC. Moreover, the overnight HK‐induced stimulation of NCC expression was significantly attenuated in the mice pretreated with PD123319 and HOE140. In contrast, HK diet (overnight) still decreased the expression of both tNCC and pNCC in the mice pretreated with PD123319 alone. We conclude that synergistic activation of AT2R and BK2R is required for the effect of overnight HK diet on NCC activity.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The role of Kv3 channels in regulating epithelial mesenchymal transition
Authors: Sim Hunju , Lee So Yeong
Published: June 2021

Epithelial mesenchymal transition (EMT) and mesenchymal epithelial transition (MET) are closely related to cancer progression. EMT is demonstrated to alter cell adhesion and cell motility. Recently, it has been suggested that ion channels, including voltage‐gated potassium (Kv) channels are also involved in a consequence of EMT.

Dogs are recognized as effective models of cancer development and in clinical therapeutic trials. In the present study, we used canine breast cancer cells, CHMp, which have mesenchymal characteristics, to investigate the involvement of Kv3 channels in the EMT/MET processes. We found that treatment with blood depressing substance II (BDS), which is a specific Kv3 subfamily blocker, increased the expression of cytokeratin‐18, an epithelial cell marker and decreased the expression of vimentin, a mesenchymal cell marker. These results suggest that blockade of Kv3 using BDS induced MET in CHMp cells. Future research is needed to elucidate the specific mechanisms governing the relationship between Kv3 and EMT/MET.

Support or Funding Information

This research was supported by the Bio and Medical Technology Development Program of the National Research Foundation (NRF) funded by the Ministry of Science, ICT and Future Planning (NRF‐2016M3A9B6026771).

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Long‐Term Dexamethasone Exposure Down‐Regulates Hepatic TFR1 and Reduces Liver Iron Concentration in Rats
Authors: Huifang Li
Published: June 2021

Exposure to stress is known to cause hepatic iron dysregulation, but the relationship between prolonged stress and liver iron metabolism is not yet fully understood. Thirty 13‐week‐old female Sprague–Dawley rats were randomly divided into two groups, as follows: the control group (saline‐injection) and the dexamethasone group (Dexamethasone (Dex)‐injection 0.1 mg/kg/day). After the 21‐day stress trial, the results showed that chronic Dex administration not only impaired serum corticosterone (p = 0.00) and interleukin‐6 (IL‐6) (p = 0.01) levels, but also decreased white blood cell counts (p = 0.00), and reduced blood lymphocyte counts (p = 0.00). The daily Dex‐injection also significantly reduced body weight (p < 0.01) by inhibiting food intake. Consecutive Dex administration resulted in decreased iron intake (p = 0.00), enhanced serum iron levels (p = 0.01), and increased the serum souble transferrin receptor (sTfR) content (p = 0.00) in rats. Meanwhile, long‐term Dex exposure down‐regulated duodenal cytochrome b (DCYTB) (p = 0.00) and the divalent metal transporter 1 (DMT1) (p = 0.04) protein expression, but up‐regulated ferroportin (FPN) protein expression (p = 0.04). Chronic Dex administration reduced liver iron concentration (p = 0.02) in rats. Hepatic transferrin receptor 1 (TFR1) expression was lowered at the protein level (p = 0.03), yet with uncoupled mRNA abundance in Dex‐treated rats. Enhanced iron‐regulatory protein (IRP)/iron‐responsive element (IRE) binding activity was observed, but did not line up with lowered hepatic TFR1 protein expression. This study indicates that long‐term Dex exposure reduces liver iron content, which is closely associated with down‐regulated hepatic TFR1 protein expression.

Support or Funding Information

This work was supported by grants from the National Natural Science Foundation of China (31302053), the Fundamental Research Funds for the Central Universities (KJQN201404), the Innovation Project of Jiangsu Province Postgraduate Education (2013CXLX13_292), the Priority Academic Program Development of Jiangsu Higher Education Institutions and the Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Epithelial Sodium Channel (ENaC) in Endothelium Modulates Vascular Reactivity with a High Salt Diet
Authors: Mutchler Stephanie M , Kleyman Thomas R
Published: June 2021

Recent work has shown that ENaC in the endothelium is involved in vascular dysfunction in the setting of high fat diet and increased aldosterone. However, the effects of endothelial ENaC in the setting of high salt diet (HSD) are unclear, especially in mouse models. Therefore, we aimed to investigate the effects of chronic HSD (8 weeks) on vascular health. Using pressure myography, we found that 8 weeks of HSD significantly reduced acetylcholine (Ach) responsiveness in the thoracodorsal artery (TDA) of mice. This dysfunction was ameliorated when 5mM amiloride, an ENaC inhibitor, was added to the lumen of the vessels. In vessels taken from animals fed a control diet (0.4% NaCl), the addition of amiloride had no effect on Ach‐mediated vasodilation. Additionally, amiloride did not significantly alter sodium nitroprusside or phenylephrine response in the 8 week HSD vessels, suggesting amiloride is directly affecting endothelial function, potentially through altered nitric oxide release. Mice fed an 8 week regimen of HSD had significantly higher serum [Na+] and decreased plasma aldosterone level, suggesting that increased aldosterone is not solely responsible for endothelial ENaC expression. Additionally, an endothelial‐specific deletion of gamma ENaC, generated using an inducible cre‐lox system, appears to offer protection from HSD‐induced vascular dysfunction, as three of six control animals showed decreased responsiveness to Ach with 8 weeks of HSD whereas zero of five knockout animals tested showed endothelial dysfunction. Taken together, these data demonstrate that endothelial ENaC has a role in promoting the vascular dysfunction seen with chronic high salt intake. Ongoing studies are examining the role of ENaC in modulating nitric oxide and eNOS phosphorylation status in the endothelial response to a HSD.

Support or Funding Information

NIH P30 2P30DK079307‐11, NIH T32 2T32DK061296‐16

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Stimulation of Muscarinic Receptors Activate Acid Sensing Ion Channel 1 in Isolated Mesenteric Artery Endothelial Tubes
Authors: Garcia Selina M , Herbert Lindsay M , Naik Jay S , Resta Thomas C , Jernigan Nikki L
Published: June 2021

Acid sensing ion channel 1 (ASIC1) belongs to the amiloride‐sensitive degenerin/epithelial sodium channel superfamily and is permeable to both Na+ and Ca2+. ASIC1 is expressed in vascular smooth muscle and/or endothelial cells of various vascular beds and is activated following stimulation of G protein‐coupled receptors (GPCR). In the pulmonary circulation, ASIC1 contributes to GPCR‐induced vasoconstriction and vascular smooth muscle Ca2+ influx via a store‐operated Ca2+ entry (SOCE) mechanism. In small mesenteric arteries, we have recently shown that ASIC1 contributes to acetylcholine (ACh)‐induced vasodilation and endothelial cell Ca2+ entry, however ASIC1‐mediated Ca2+ influx is not SOCE‐dependent in mesenteric artery endothelial cells. Thus, further investigation is needed to understand the mechanism by which ASIC1 is activated by GPCR in small mesenteric artery endothelial cells. Previous studies show ASIC1 is activated by arachidonic acid, therefore we hypothesized that acetylcholine stimulates ASIC1 in mesenteric artery endothelial cells through activation of phospholipase A2 (PLA2) and release of arachidonic acid. To test this hypothesis, we examined endothelial Ca2+ influx via Mn2+ quenching of fura‐2 fluorescence in freshly isolated mesenteric artery endothelial tubes. The PLA inhibitor methyl arachidonyl fluorophosphonate (MAF; 500 nM) attenuated the Ca2+ entry response to ACh, confirming that PLA2‐signaling contributes to the ACh‐induced Ca2+ entry in mesenteric artery endothelial cells. In addition, the selective inhibitor of ASIC1, psalmotoxin 1 (PcTX1; 20 nM), attenuated arachidonic acid‐induced Ca2+‐influx in mesenteric artery endothelial tubes. Although these studies suggest stimulation of muscarinic receptors activate ASIC1 through a PLA2‐arachidonic acid signaling mechanism in mesenteric endothelium, further studies are needed to identify the downstream effector of ASIC1.

Support or Funding Information

Supported by National Heart, Lung, and Blood Institute Grants R01 HL‐111084 (to N.L. Jernigan), T32 HL007736 (to T.C. Resta), and American Heart Association Grant 18TPA34110281 (to N.L. Jernigan).

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Magnetic resonance hyperpolarisation imaging detects early myocardial dysfunction in a porcine model of right ventricular heart failure
Authors: Agger Peter , Hyldebrandt Janus Adler , Hansen Esben Søvsø Szocska , Omann Camilla , Bøgh Nikolaj , Waziri Farhad , Nielsen Per Mose , Laustsen Christoffer
Published: June 2021

Background

Early detection of heart failure is important for timely treatment. During development of heart failure adaptive, intracellular processes that evolve prior to macro‐anatomic pathology could provide an early signal of impending heart failure. Therefore, metabolic alterations following cardiac dysfunction would appear early in disease progression. We hypothesised that metabolic imaging with hyperpolarised magnetic resonance can detect early development of heart failure before conventional echocardiography detects cardiac dysfunction.

Methods and Results

Five 8.5 kg piglets were subjected to pulmonary banding and subsequently examined by [1‐13C]pyruvate hyperpolarisation, conventional magnetic resonance imaging, echocardiography, and blood samples every four weeks for 16 weeks. They were compared with a weight matched, healthy control group. Conductance catheter examination at the end of the study showed impaired right ventricular systolic function along with compromised left ventricular diastolic function. After 16 weeks we saw a significant decrease in the left ventricular conversion ratio of pyruvate/bicarbonate from 0.13 (0.04) in controls to 0.07 (0.02) in animals with pulmonary banding, and a significant increase in the lactate/bicarbonate ratio to 3.47 (1.57) versus 1.34 (0.81) in controls. NT‐proBNP was increased by more than 300%, while cardiac index was reduced to 2.8 (0.95) l/min/m2 versus 3.9(0.95)in controls. Echocardiography revealed no changes.

Conclusion

Hyperpolarisation detected a shift towards anaerobic metabolism in early stages of right ventricular dysfunction as evident by an increased lactate/bicarbonate ratio. Dysfunction was confirmed with conductance catheter assessment, but could not be detected by echocardiography. Hyperpolarisation holds a promising future in clinical assessment of heart failure in both acquired and congenital heart disease.

Support or Funding Information

The study is funded by the Danish Children Heart Foundation.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Propofol Does Not Attenuate the Cardioprotective Effect of Mild Hypothermia in Swine
Authors: Zimmer Henry , Techiryan George , Smith Cody , Canty John M , Weil Brian R
Published: June 2021

Objective

Previous experimental studies have demonstrated that mild reductions in body temperature can decrease infarct size in the setting of acute myocardial infarction (MI). However, it has been suggested that the cardioprotective effects of mild hypothermia and other conditioning interventions are attenuated by concomitant administration of propofol. To address this issue, we evaluated the relationship between body temperature and infarct size in propofol‐anesthetized swine subjected to prolonged myocardial ischemia and reperfusion.

Methods

Swine (n=17) were anesthetized with propofol (10 mg/kg/hour) and subjected to a 60‐minute balloon occlusion of the distal left anterior descending coronary artery (LAD) in the closed‐chest state. Serum cTnI values were quantified by a porcine‐specific ELISA at baseline and 1‐hour after reperfusion. Infarct size (triphenyl tetrazolium chloride) and ischemic area‐at‐risk (AAR; phthalocyanine blue during coronary re‐occlusion) were assessed post‐mortem 3‐hours (n=2), 24 hours (n=5), or 7 days (n=10) after reperfusion.

Results

Direct, statistically significant (p<0.01) correlations were observed between body temperature at reperfusion and infarct size relative to AAR (r=0.75), infarct size relative to LV mass (r=0.70), and serum cTnI 1‐hour after reperfusion (r=0.78). When animals were divided into two groups based on median body temperature at reperfusion (37.5 °C), animals with a body temperature <37.5 °C exhibited significantly smaller infarcts and lower serum cTnI values than animals with a body temperature > 37.5 °C (Table). Importantly, low body temperature‐related reductions in infarct size were observed in the absence of group differences in the duration of reperfusion, LV mass, and ischemic AAR.

Conclusion

These results demonstrate that the cardioprotective effect of mild hypothermia is not attenuated in the setting of propofol anesthesia. Furthermore, the marked reduction in infarct size associated with relatively minor diminutions in body temperature provides further support for the notion that even modest reductions in body temperature within a normothermic range may be an effective approach to limit infarct size in patients with acute MI.

Support or Funding Information

The National Heart Lung and Blood Institute (HL‐061610), the American Heart Association (17SDG33660200), the National Center for Advancing Translational Sciences (UL1TR001412), the Department of Veterans Affairs (1IO1BX002659), the New York State Department of Health (NYSTEM CO24351, the UB Center for Undergraduate Research and Creative Activities, and the Albert and Elizabeth Rekate Fund in Cardiovascular Medicine.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Hydrogen Sulfide Protects Against Sepsis‐Induced Myocardial Dysfunction by Inhibiting inflammation and Endoplasmic Reticulum Stress
Authors: Wu Yuming , Chen Yuhong , Jin Sheng , Teng Xu , Tian Danyang
Published: June 2021

Hydrogen sulfide (H2S) is involved in the regulation of several physiologic processes and pathophysiologic conditions. However, the role of H2S in the development of Sepsis‐induced myocardial dysfunction (SIMD) remains unknown. In the present study, 10 patients with SIMD and 10 healthy controls were examined to investigate the role of H2S in SIMD. Compared with the Control group, the plasma levels of cardiac troponin I (cTnI), creatine kinase (CK), tumour necrosis factor‐α (TNF‐α) and interleukin‐1β (IL‐1β) were significantly higher in the SIMD group, but left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) were significantly lower. Furthermore, the plasma level of H2S was lower in the SIMD group, and the level of H2S was linearly correlated with the levels of LVEF and LVFS. Subsequently, we established a mouse model of SIMD induced by lipopolysaccharide (LPS) and used the H2S donor NaHS to clarify the role of H2S in the development of SIMD. LPS‐treated mice exhibited decreased levels of LVEF and LVFS and increased myocardial damage as well as increased levels of TNF‐α, IL‐1β, cTnI and CK. In addition, the protein levels of Toll‐like receptor (TLR)4 and endoplasmic reticulum stress (ERS) markers were over expressed in the SIMD mice; these changes were more severe in cystathionine γ‐lyase (CSE) knockout (CSE KO) mice. NaHS, which was administered intraperitoneally 3h after LPS treatment, could improve cardiac damage and strongly attenuated LPS‐induced inflammation and ERS in the SIMD mice. Overall, these findings indicate that H2S can protect against SIMD by inhibiting inflammation and ERS through the TLR4 signalling pathway.

Support or Funding Information

This study was supported by the National Natural Science Foundation of China (Grant 31671185, 31171098, 31871154).

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Catestatin Improves Insulin Sensitivity by Promoting M1‐M2 Polarization and Inhibiting Obesity‐Induced Macrophage Infiltration and Gluconeogenesis in Liver
Authors: Mahata Sushil Kumar , Ying Wei , Muntjewerff Elke M , Mahata Sumana , Nicolasen Mara J.T. , Das Soumita , Bandyopadhyay Gautam Kumar , van den Bogaart Geert
Published: June 2021

Objective

Components of the innate and adaptive immune system are affected in obesity and Type 2 diabetes (T2D) and inflammation participates in the pathogenesis of T2D. The activation of the resident Kupffer cells and monocyte (Mc)‐derived recruited macrophages (McMΦs) in the liver contributes to obesity‐induced insulin resistance (IR) and T2D. Here, we sought to determine whether the Chromogranin A (CgA) peptide Catestatin (CST: human CgA352–372) regulates recruitment of macrophages and modulates metabolism in insulin‐resistant diet‐induced obese (DIO) mice as well as M1–M2 polarization in human monocytes.

Methods and Results

CST treatment of DIO mice diminished the expression of gluconeogenic genes, attenuated expression of pro‐inflammatory genes, increased expression of anti‐inflammatory genes in McMΦs, and inhibited infiltration of McMΦs, leading to improvement of insulin sensitivity. To gain better insights into the mechanism of action of CST, we isolated CD14+ subsets of monocytes from buffy coats from healthy individuals. The monocytes were cultured with M‐CSF towards undifferentiated MΦs and subsequently polarized towards pro‐inflammatory and anti‐inflammatory phenotypes with GM‐CSF, IFN‐γ and LPS or M‐CSF and IL4, respectively. RNA sequencing of proinflammatory MΦs revealed that CST decreased expression of proinflammatory genes in proinflammatory (e.g., IL23A, FCRLA, and IL1A) as well as in anti‐inflammatory MΦs (e.g., IL11RA, SP140, NLRCS, and TRIM34). In anti‐inflammatory macrophages, CST increased expression of anti‐inflammatory genes. Consistent with gene expression, CST exposure to anti‐inflammatory MΦs enhanced IL‐10 production but not in pro‐inflammatory MΦs, whereas CST inhibited TNFα and IL‐6 production in both cultures.

Conclusion

We conclude that (i) CST attenuated macrophage mediated inflammation, resulting in improved insulin sensitivity in obese mice. (ii) CST promoted M1–M2 polarization by decreasing expression of proinflammatory cytokines and increasing expression of ant‐iinflammatory cytokines.

Support or Funding Information

Supported by grants from the VA (I01BX000323 to S.K.M.), and the NWO Gravitation Programme 2013 (ICI‐024.002.009 to G.v.d.B.), and a Vidi grant from the Netherlands Organization for Scientific Research (NWO‐ALW VIDI 864.14.001 to G.v.d.BG.v.d.B.).

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Characterizing the Sensory and Affective Phenotype of Kappa Opioid Receptor Cre Knockin Mice in Response to Chronic Variable Stress and Inflammation
Authors: Zaheer Meeraal , Kolber Benedict J.
Published: June 2021

Kappa Opioid Receptors (KORs) are an alternative opioid targeting site with the potential of targeting pain without the abuse associated with Mu Opioid Receptors (MORs). KORs have been linked to nociception and mood, and modulate responses to chemical, mechanical and thermal nociceptive stimuli. The KOR‐Cre knockin model is a novel method used to drive expression of the exogenous protein Cre recombinase using the endogenous KOR locus. While this model allows for study and visualization of KOR‐expressing cells, the full consequences of losing either one or both KOR alleles in these mice is not well characterized. We evaluated the sensory and affective phenotype of KOR‐Cre knockin homozygous and heterozygous mice before and after a 10‐day chronic variable stress (CVS) paradigm and the induction of inflammatory pain with Complete Freund's Adjuvant (CFA). We tested for mechanical (von Frey) and thermal (Hargreaves) sensory behavior, as well as depressive and anxiolytic affective behavior. We report sex‐specific differences in the sensory, but not affective phenotype in this model. We observe decreased depressive and increased anxiolytic behavior in KOR‐Cre heterozygous mice post‐CVS. Male mice exhibit mechanical hypersensitivity while both sexes of KOR‐Cre homozygous mice exhibit thermal hyposensitivity post‐CVS. Administration of CFA elicits contralateral thermal hyposensitivity in male KOR‐Cre heterozygous and female homozygous mice, while no changes in mechanical sensitivity are observed in either sex. We conclude that sex‐specific differences must be accounted for when conducting pain research, as CVS and CFA results in variation in pain incidence between sexes. Moreover, lack of activity in KOR‐Cre homozygous mice post‐CVS may result in signs of pain resilience in the absence of the receptor under stress. Furthermore, hyposensitivity post‐CFA could indicate that pain‐related function in KORs may act through a synergistic compensatory mechanism combining the activity of both MORs and KORs. Our results suggest that caution should be used when substituting KOR‐Cre heterozygous mice for WT mice. By characterizing this model, we provide a baseline for which the model can be compared to when conducting research on KOR‐positive cells.

Support or Funding Information

Research supported by NIH R25NS100118 (BJK, KJT, MC, MRM) and the APS UGRSF (MZ).

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Statin Therapy Enhances Reflex Cutaneous Vasodilation in Formerly Hypercholesterolemic Older Adults by Improving Neurovascular Coupling
Authors: Greaney Jody L , Stanhewicz Anna E , Kenney W. Larry
Published: June 2021

Reflex cutaneous vasodilation is attenuated in healthy human aging and is mediated by alterations in both central (sympathetic outflow) and peripheral (microvascular endothelial) function. Hypercholesterolemia, a primary risk factor for cardiovascular disease, is associated with increased sympathetic nervous system activity and further impairments in endothelial function. Independent of their lipid‐lowering effect, HMG‐CoA reductase inhibitors (statins) – the most commonly prescribed medication in the U.S. – reduce sympathetic outflow and augment endothelium‐dependent dilation. However, whether statin therapy improves the relation between skin sympathetic nervous system activity (SSNA) and cutaneous vascular conductance (CVC) during passive heat stress is unknown. We hypothesized that (1) hypercholesterolemic older adults would demonstrate blunted increases in both SSNA and CVC during passive heating and (2) chronic statin treatment would improve the response range and sensitivity of the SSNA:CVC relation. Reflex vasodilation was induced in 13 healthy normocholesterolemic older adults [62±2 yrs; low‐density lipoprotein (LDL) 113±7 mg/dl), 10 hypercholesterolemic older adults (60±1 yrs; LDL 183±2 mg/dl), and 10 previously hypercholesterolemic older adults now treated with a lipophilic statin (10–40 mg daily) to normalize LDL (64±1 yrs; LDL 102±2 mg/dl) using a water‐perfused suit to elevate oral temperature (Tor) by 1.0°C. SSNA (peroneal microneurography) and red cell flux (laser Doppler flowmetry) in the innervated dermatome (the dorsum of foot) were continuously measured. SSNA was normalized to, and expressed as, a percentage of baseline and CVC was calculated as flux/mean arterial pressure and expressed as a percentage of maximal CVC (local heating to 43°C). Mean arterial pressure, baseline CVC, and maximal CVC were not significantly different among groups (all p>0.05). During passive heating, the increase in SSNA was not different among groups (normal: Δ=393±96%, high: Δ=311±120%, and statin: Δ=256±90%; p=0.11). Reflex vasodilation was blunted in hypercholesterolemic adults, but not in statin‐treated adults, compared to normocholesterolemic adults (normal: 36±1%CVCmax, high: 32±1%CVCmax, and statin: 38±1%CVCmax respectively, at ΔTor=1.0°C; p<0.01). There were no differences among groups for the slope of the ΔSSNA:ΔCVC relation (normal: 0.06±0.00, high: 0.07±0.01, and statin: 0.07±0.01, p=0.91); however, this relation was shifted upward in statin‐treated adults (y‐intercept; normal: 3.1±0.9, high: 4.0±0.9, and statin: 7.3±1.3; p=0.001). These data demonstrate that chronic statin treatment improves reflex cutaneous vasodilation in formerly hypercholesterolemic older adults, in part via increases in end‐organ responsiveness to sympathetic outflow during passive heat stress.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Probiotic supplementation improves total and exogenous CHO oxidation in trained male cyclists: A randomized, double‐blind, placebo‐controlled cross‐over trial
Authors: Pugh Jamie , Wagenmakers Anton , Morton James , Doran Dominic , Fielding Barbara , Fleming Simon , Close Graeme
Published: June 2021

Background

In vitro and animal studies suggest probiotic supplementation can enhance intestinal absorption and whole body oxidation rates of glucose.

Objective

This study investigated the effects of multi‐strain probiotics supplementation on substrate utilization, markers of gastrointestinal permeability and damage and subjective symptoms of discomfort and performance during endurance cycling.

Methods and Design

Nine male cyclists (age 23 ± 4 yrs, V̇O2max 62.1 ± 4.7 mL·kg−1·min−1) were randomized to two periods of daily supplementation with a probiotics capsule (25 billion CFU of Lactobacillus acidophilus (CUL60 and CUL21), Bifidobacterium bifidum (CUL20), Bifidobacterium animalis subsp. lactis (CUL34), Proven Probiotics) or placebo for four weeks, separated by a 14‐day washout period (double‐blind cross‐over trial). After each supplementation period, cyclists consumed a 10% maltodextrin solution (initial 8 mL·kg−1 bolus at commencement of exercise and 2 mL·kg−1 every subsequent 15 min) while exercising for 120 minutes at 55% Wmax. This was followed immediately by a 100 kJ time trial performance test. Markers of GI permeability, damage and GI discomfort were assessed. Oxidation rates of the ingested maltodextrin drinks were calculated from the 13C‐enrichment of plasma glucose and breath 13CO2 production during the 120 minutes exercise period.

Results

Probiotic supplementation resulted in an increase of total carbohydrate (CHO) oxidation (2.12 ± 0.30 vs 1.81 ± 0.44 g·min1, P = 0.019) and the peak oxidation of an ingested maltodextrin drink (0.84 ± 0.10 vs 0.77 ± 0.09 g·min−1 of glucose equivalents, P = 0.016) during exercise. Total fat oxidation was reduced following probiotic supplementation compared to placebo (P = 0.004). There were also significant differences in plasma insulin, NEFA and glycerol between trials. Differences between markers of GI damage and permeability were not significant, as was time trial performance (P > 0.05).

Conclusions

Probiotic supplementation enhances total and ingested CHO oxidation while simultaneously attenuating total fat oxidation during moderate intensity cycling. Probiotic supplementation did not change GI symptoms, time trial performance and markers of intestinal damage and permeability.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Value of Cadaveric Dissection in Undergraduate Medical Education: A Student's Perspective on the State of Affairs
Authors: Smith Jake
Published: June 2021

Throughout the past 15 years, medical schools around the world have interrogated the value of cadaveric dissection in anatomy courses during undergraduate medical education (UME) in light of advances in medical imaging, increasing costs of UME, decreased time allotted to anatomy education, and the availability of high‐quality prosections and models.

Proponents of dissection argue that in addition to gaining knowledge of anatomy at the basic science level, medical students develop qualities vital to the practice of medicine such as developing clinician habits‐of‐mind, understanding 3D anatomy as it relates to medical imaging, and reflecting on death and dying. Furthermore, medical students themselves feel as though dissection enhances their ability to work as a team, undergo professional development, and come to terms with death. Proponents also note that deep learning of any subject is cultivated by direct experiential learning, which may describe dissection to a greater degree than other learning modalities.

Detractors, however, argue that such qualities can be instilled in students at other times throughout UME, and that because physicians primarily interact with anatomy through medical imaging and living models, the time spent dissecting may be better spent gaining proficiency with these modalities. Other detractors have claimed that many of the benefits of dissection such as touch‐mediated learning and exposure to death and dying can be obtained through prosection. Detractors also note that dissection has been shown to be no better than other modalities in impacting student performance on anatomy exams.

This presentation will review the existing literature regarding the dissection vs prosection debate and provide perceptional feedback on both instructional methodologies from the perspective of a current medical student who has experience teaching and learning anatomy through various modalities at the undergraduate, graduate, and professional school levels.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Gender specific effects on growth, postural muscles and deep pressure sensitivity in hindlimb unloading
Authors: Chowdhury Parimal , Pathak Rupak , Griffin Robert J , Mehta Rahul , Dobretsov Maxim
Published: June 2021

Hind limb unloading is a NASA validated animal model of simulated weightlessness. The aim of this study is to test the gender‐specific effects in a hindlimb suspended rat model of microgravity.

Methods

Adult male and female rats were suspended for two weeks using two different methods. A separate group of male and female rats served as control (non‐suspended). Body weights, food and water consumption, soleus muscle weights, pressure‐pain thresholds (PPT) and insulin levels were measured.

Results

For a given gender, none of measured characteristics differed between the two suspended rats. Therefore the results with different suspension techniques were combined and pooled together for further analysis. Data show that food and water intakes were not different between genders and between control and suspended groups. Compared to control males, control female rats had the same PPT value, but weighed less, had lower soleus muscle mass and gained weight slower. HLS nearly canceled the weight gain and resulted in the development of pressure hyperalgesia in both gender groups. However, HLS‐associated soleus muscle atrophy was detected in male rats only. Furthermore, in a sub‐group of experiments in which both PPT and plasma insulin were measured, HLS was found to decrease insulin concentrations and affect pain thresholds in male rats only.

Conclusions

Overall HLS appear to influence growth, postural muscles and deep pressure sensitivity of males and it is stronger and consistent than those of female rats

Support or Funding Information

Supported by a grant from Arkansas Space Grant Consortium

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.