bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of sitting and calf exercise on fluid accumulation below the knees (1156.13)
Authors: Singh Bhajan , Yadollahi Azadeh , Bradley T
Published: June 2021

Background: Overnight rostral fluid shift from the legs to the neck correlates with the severity of obstructive sleep apnea (OSA) and time spent sitting. Sitting causes gravity‐dependent fluid accumulation in the legs that is counteracted by walking. However most office workers are required to sit for long periods and walking to preventing fluid accumulation in the legs is impractical. We hypothesized that sitting would cause fluid accumulation below the knees that could be attenuated by calf exercise while sitting.

Methods: We measured fluid volume (FV) below both knees using bioelectrical impedance in 10 healthy subjects (8 men, age 50.8±6.2 yrs, BMI 23.7±2.4 kg/m2). Measurements were made in the supine, erect and seated postures and while sitting for 4 hours. Subjects were studied twice, a week apart, in a randomised double cross‐over design: control ‐ no calf exercise, intervention ‐ 15 calf muscle contractions against a pedal resistance (Step‐It) every 15 min. Paired t‐tests were used to analyze changes in FV and the effect of the intervention.

Findings: Relative to the supine posture, FV below the knees increased in the erect (64.7±28.9 ml, p<0.0001) and seated postures (135.8.7±59.2 ml, p<0.0001) and after 4 hours of sitting (251.0±65.7 ml, p<0.0001). Modest exercise using the Step‐It device while sitting did not reduce fluid accumulation (control 115.2±47.0 ml, intervention 120.0±28.0 ml, p=0.72).

Conclusions: Sitting for 4 hours results in substantial fluid accumulation in the legs of healthy subjects and this is not attenuated by modest intermittent calf exercise using a Step‐It device. This fluid could serve as a reservoir for redistribution to the neck and lungs during sleep, and contribute to OSA in predisposed individuals. A higher level of calf activity may be required to reduce fluid accumulation in the legs when sitting.
The importance of the thioredoxin system in muscle mitochondrial reactive oxygen species metabolism (1159.10)
Authors: Treberg Jason , Banh Sheena , Sotiri Emianka , Zacharias Pamela , Tamanna Nahid
Published: June 2021

Mitochondria are widely recognized as a potential source of reactive oxygen species (ROS); however, mitochondria also possess a strong capacity for ROS consumption that is often underappreciated. In skeletal muscle the glutathione and thioredoxin based peroxidase systems are likely the major H2O2 consumption pathways. Here we demonstrate the thioredoxin‐based pathway is the major H2O2 consumer in isolated rat skeletal muscle mitochondria. Unlike 1‐chloro‐2,4‐dinitrobenzene, the thioredoxin reductase inhibitor auranofin does not elevate ROS production in disrupted membranes that are devoid of the capacity to consume H2O2. Inhibition of thioredoxin reductase with auranofin leads to a marked increase in apparent ROS production but no change in mitochondrial bioenergetic characteristics (oxygen consumption, membrane potential, %NAD(P)H). Moreover, auranofin also inhibits the capacity for H2O2 consumption by isolated mitochondria and does not appear to act through the inhibition of the glutathione reduction system. We conclude that the apparent increase is H2O2 release by treatment with auranofin is due to impaired matrix level thioredoxin‐dependent H2O2 consumption and not reflective of an activation of ROS production.

Grant Funding Source: Supported by Canada Research Chairs (CRC), CFI, Manitoba Research and Innovation Fund and NSERC
The enzyme nagarse modifies parameters associated with function of mechanically‐liberated mitochondria (1159.7)
Authors: Kras Katon , Willis Wayne , Barker Natalie , Czyzyk Traci , Katsanos Christos
Published: June 2021

Nagarse (N) is traditionally used to isolate mitochondria (mito) from skeletal muscle (SM). We investigated the effects of N on functional parameters of mechanically liberated mito. Mito from mouse (n = 7) gastrocnemius muscle (119‐175 mg tissue) was isolated using a glass on glass homogenizer followed by differential centrifugation. The 800g supernatant from the first centrifugation, containing mito, was divided into two equal volumes. One was exposed to N and the other was not. In each volume, mito were isolated by standard differential centrifugation. State 3 max ADP‐stimulated O2 consumption rates (Jo) were measured using polarography with malate + pyruvate + glutamate. N increased state 3 Jo, 16.1 ± 1.1 vs. 11.9 ± 1.4 nmol O2 / ml mito suspension / min; P < 0.004, while it decreased protein concentration in the final mito suspension (typically used to adjust final Jo values), 1.9 ± 0.1 vs. 2.5 ± 0.1 mg / ml; P < 0.004. Citrate synthase activity in the final mito suspension, indicative of the available mito, was not different in the preparation treated with N vs. that not treated with N (0.067 ± 0.01 vs. 0.065 ± 0.01μmol / min; P = 0.8). These findings suggest that N treatment: 1) hydrolyzes non‐mito contaminating proteins in the final mito pellet, and 2) induces apparent qualitative changes in mito function. Therefore, calculated functional parameters of mito treated with N are not directly comparable to mito not treated with N.

Grant Funding Source: Supported by NIH/NIDDK RO1 DK094062
Dipeptidyl peptidase‐4 inhibitor lowers PPARγ agonist‐induced body weight gain by affecting food intake, fat mass and beige/brown fat but not fluid retention (1160.9)
Authors: Fu Yiling , Masuda Takahiro , Eguchi Akiko , Czogalla Jan , Rose Michael , Kuczkowski Alexander , Gerasimova Maria , Feldstein Ariel , Scadeng Miriam , Vallon Volker
Published: June 2021

DPP‐4 inhibitors are anti‐diabetic drugs that enhance renal Na+ and fluid excretion. We tested whether the DPP‐4 inhibitor alogliptin (ALG) ameliorates PPARγ agonists pioglitazone (PGZ)‐induced fluid retention and body weight (BW) gain. Male Sv129 mice were treated with vehicle, PGZ (220mg/kg diet), ALG (300mg/kg diet) or PGZ+ALG for 14 days (n=8‐10/group). PGZ+ALG prevented the PGZ‐induced BW increase, but did not affect fluid retention as determined by bioimpedance spectroscopy (BIS). BIS showed that ALG alone had no effect on fat mass (FM), but enhanced the FM lowering effect of PGZ; MRI analysis confirmed the latter and showed reductions in visceral and inguinal subcutaneous (sc) white adipose tissue (WAT). ALG, but not PGZ, decreased food intake and plasma free fatty acid concentrations. PGZ, but not ALG, increased mRNA expression of thermogenesis mediator UCP1 in epididymal WAT. PGZ+ALG increased the expression of brown‐fat‐like “beige” cell marker TMEM26 in scWAT and interscapular brown adipose tissue and increased rectal temperature versus vehicle. All mentioned differences were statistically significant. In summary, DPP‐4 inhibition did not attenuate PPARγ agonist‐induced fluid retention, but prevented BW gain by reducing FM. This involved ALG‐inhibition of food intake and was associated with synergistic effects of PPARγ agonism and DPP‐4 inhibition on beige/brown fat cells and thermogenesis.
Leukemia inhibitory factor stimulates muscle glucose uptake by a PI3‐kinase dependent pathway that is maintained in white muscle in obesity (1162.4)
Authors: Brandt Nina , O'Neill Hayley , Kleinert Maximilian , Schjerling Peter , Steinberg Gregory , Richter Erik , Jorgensen Sebastian
Published: June 2021

OBJECTIVE: To investigates the metabolic effects of leukemia inhibitory factor (LIF) in mouse skeletal muscle.

METHODS: Effects of LIF on muscle glucose transport, palmitate oxidation and cellular signaling were investigated in soleus and extensor digitorum longus (EDL) muscles from chow and highfat diet fed wildtype (WT) mice or chow fed muscle‐specific AMPKα2 kinase‐dead (KD) and suppressors of cytokine signaling (SOCS) 3 muscle‐specific knockout mice.

RESULTS: LIF increased muscle glucose transport in a dose‐ and time‐dependent manner. LIF increased Akt Ser473‐P, whereas AMPK Thr172‐P was unaffected. Incubation of muscles from KD or WT mice with Wortmannin, LY294002 and Parthenolide demonstrated that PI3‐kinase, but not AMPK, was essential for LIF‐stimulated glucose transport. Incubation with Rapamycin and AZD8055 demonstrated that mammalian target of rapamycin complex (mTORC)2 and not mTORC1 is necessary for LIF‐stimulated glucose transport. LIF‐stimulated glucose transport was maintained in EDL muscle from obese insulin resistant mice. Lack of SOCS3 did not affect LIF‐stimulated glucose uptake.

CONCLUSIONS: LIF acutely increases muscle glucose transport by a mechanism involving the PI3‐kinase/mTORC2/Akt pathway which is maintained in EDL muscle from obese insulin resistant mice.
ATP release induced by electrical stimuli increase ROS production and RyR glutathionylation via P2Y1‐PKC‐NOX2 in skeletal muscle fibers (1164.5)
Authors: Díaz Alexis , Campos Cristian , Jaimovich Enrique , Espinosa Alejandra
Published: June 2021

During exercise, skeletal muscle produces ROS via NOX2 while inducing some adaptations associated with contractile activity; the signals involved in this mechanism are debated.

ATP is released from skeletal muscle during electrical stimulation and can signal autocrinely through purinergic receptors, we hypothesized that it may influence ROS production. The aim of this work was to measure ROS production induced by electrical stimulation and extracellular ATP. Electrical stimulation triggered a ROS transient increase in muscle fibers. The ROS production was mimicked by extracellular ATP and was prevented by CBX and suramin, antagonists of pannexin channel and purinergic receptors respectively. MRS2365, a P2Y1 receptor agonist induced a large signal while UTPyS (P2Y2 agonist) elicited a much smaller signal that was mimicked using ATP plus MRS2179, an antagonist of P2Y1. Inhibitors suggest that ROS production induced by ES or extracellular ATP was mediated by NOX2 via PKC. Extracellular ATP induced glutathionylation of RyR via NOX2. Electrical stimulation increase ROS production via P2Y1‐NOX2 and this effect appears to be involved in the regulation of RyR oxidation and thus in the regulation of calcium signaling in skeletal muscle fibers.

Grant Funding Source: ACT 1111, Fondecyt 11090301
Effect of sub‐occipital release and systemic acetylsalicylic acid administration on pain perception and autonomic reflex responses to pain (1170.9)
Authors: Metzler‐Wilson Kristen , Schaub Andrew , Vrable Abby , Krause B. , Wilson Thad
Published: June 2021

To determine the autonomic effects of sub‐occipital release (SOR) during experimentally induced pain, 16 healthy subjects (8 women, 8 men) experienced ischemic (forearm post‐exercise muscle ischemia; PEMI) and cold (hand cold pressor test; CPT) pain. Heart rate (HR; ECG) and mean arterial blood pressure (MAP; photoplethysmography) were measured. SOR or a sham control (modified yaw; 30 cycles/min) was performed in the final min of experimental pain. PEMI caused increases in MAP of 23±2 and 20±2 mmHg, but no differences were observed with the addition of either SOR or yaw. PEMI modestly elevated HR during ischemia, followed by a significant reduction with SOR (‐3±2 bpm) and yaw (‐4±2 bpm) from baseline, but no differences were observed between treatment and sham. CPT increased MAP (11±1 and 9±2 mmHg) and HR (10±2 and 8±3 bpm) prior to SOR and yaw. Neither treatment nor sham blunted MAP increases (SOR = 25±2, yaw = 22±2 mmHg) to CPT, but both decreased HR (SOR = 3±2, yaw = 2±2 bpm) from baseline. To further probe potential mechanisms, systemic acetylsalicylic acid (ASA; 967 mg) was given 60 min prior to testing to reduce prostaglandin (PG) synthesis. ASA blunted pain perception but did not alter cardiovascular changes to PEMI and did not interact with SOR or yaw. These data indicate that that both SOR and sham may be affecting the parasympathetic nervous system via a non‐PG mechanism.

Grant Funding Source: Supported by a grant from the American Osteopathic Association
H2O2 decreases ASIC1 plasma membrane localization in rat pulmonary arterial smooth muscle cells (1175.3)
Authors: Plomaritas Danielle , Herbert Lindsay , Resta Thomas , Walker Benjimen , Jernigan Nikki
Published: June 2021

Acid sensing ion channel 1 (ASIC1) mediates enhanced store operated calcium entry (SOCE) in pulmonary arterial smooth muscle cells (PASMC) and contributes to the development of chronic hypoxia (CH)‐induced pulmonary hypertension. ASIC1 is a redox sensitive ion channel, such that reducing agents increase and oxidizing agents decrease channel activity. Recent studies from our laboratory have shown that 1) hydrogen peroxide (H2O2) inhibits ASIC1‐dependent SOCE in PASMC and 2) pulmonary arterial H2O2 levels are decreased following CH which may contribute to the enhanced SOCE. Considering that H2O2 has additionally been shown to decrease ASIC1 cell surface expression in neurons, we hypothesized that H2O2 inhibits plasma membrane localization of ASIC1 in PASMC. Using a cell surface biotinylation assay, we found a 2.9 ± 0.1 fold increase in plasma membrane ASIC1 expression in PASMC from CH animals compared to control (two‐tailed P value=0.0002). In PASMC from control rats pretreatment with PEG‐catalase (250 U/ml; 1 hr at 37°C) increased and H2O2 (25 µM; 1 hr at 37°C) decreased ASIC1 surface expression compared to vehicle treated PASMC (one way ANOVA P value<0.001). We conclude that ASIC1 plasma membrane localization is inhibited by H2O2 in PASMC and this represents one potential mechanism by which the loss of H2O2 following CH enhances ASIC1‐dependent Ca2+ influx in PASMC.

Grant Funding Source: Supported by T32‐HL07736; R01‐HL111084; K01 HL092598
Excessively increased pulmonary artery systolic pressure during exercise in adults with a history of extreme premature birth is unresponsive to sildenafil (1175.8)
Authors: Mangum Tyler , Duke Joseph , Elliott Jonathan , Goodman Randall , Gladstone Igor , Lovering Andrew
Published: June 2021

Extreme preterm birth results in abnormal alveologenesis and pulmonary vasculogenesis. Abnormal pulmonary vasculature may be unable to accommodate increased cardiac output during exercise, thereby resulting in an abnormally increased pulmonary artery systolic pressure (PASP) and exercise‐induced pulmonary hemorrhage (EIPH) in adult with a history of extreme preterm birth (PRE). We hypothesized that 1) PRE would have increased PASP during exercise thereby causing EIPH and 2) oral sildenafil would reduce PASP thereby preventing EIPH. PRE (n = 2) performed exercise at 80% of max power output to exhaustion on a cycle ergometer 60 mins after 100 mg sildenafil (p.o.) and, on a separate day, without sildenafil. Age and sex matched full term controls (CON; n = 2) exercised at the same workload and for the same time as PRE. PASP was measured via ultrasonography at rest and within the last minute of exercise. Induced sputum samples were collected post‐exercise and analyzed for cellular constituents. PASP was not different at rest between groups. During exercise, PASP was greater in PRE (54 Torr) vs CONT (48 Torr) without drug, and was unchanged in PRE (59 Torr) but decreased in CONT (41 Torr), with sildenafil. There was no evidence of EIPH in either group. These data suggest that excessive PASP during exercise in PRE may be the result of abnormal pulmonary vascular architecture, which cannot be ameliorated by oral sildenafil.

Grant Funding Source: Supported by AHA Scientist Development Grant and OHSU Early Clinical Investigator Grant
Identifying genetic modifiers of autosomal recessive polycystic kidney disease (1179.1)
Authors: Flister Michael , Endres Bradley , Hoffman Matthew , Jacob Howard , Sweeney William , Avner Ellis , Moreno Carol
Published: June 2021

Autosomal recessive polycystic kidney disease (ARPKD) affects 1/20000 live births and is ~35% neonatal lethal, with ~50% of the surviving patients developing end‐stage renal disease (ESRD) within the first decade of life. ARPKD is caused by mutations in the PKHD1 gene in both humans and the orthologous rat model of ARPKD, the PCK rat. Identifying genetic modifiers of ARPKD in humans is challenging due to genetic heterogeneity and environmental variability. To circumvent this, we and others have turned to rodent models of ARPKD for candidate gene discovery. We identified 2 genetic backgrounds (FHH and SS) that attenuate ARPKD severity compared with the SD background of the original PCK rat. Compared with renal cyst formation in the SD.PCK rat (26±4), FHH.PCK (5±2; P<0.001) and SS.PCK (8±2; P<0.001) had significantly reduced cysts per renal cross‐section at 30 days of age. Reduced cyst formation was also confirmed by significantly decreased FHH.PCK (1.4±0.1g; P<0.001) and SS.PCK (1.7±0.1g; P<0.001) kidney weights compared with SD.PCK (3.1±0.2g) at 30 days of age. We hypothesized that genetic modifiers of ARPKD severity are likely shared by SS and FHH backgrounds. To identify these modifiers, renal transcripts were analyzed by microarray, which revealed 18 transcripts that concordantly changed in expression in FHH.PCK and SS.PCK kidneys (30 day), but not SD.PCK. Sequence analysis of the FHH.PCK, SS.PCK, and SD.PCK genomes showed that 5 out of 18 transcripts (Ndrg1, Hsd3b, Fmo1, Grtp1, and Proc1) reside in regions that are significantly enriched with variants that are shared by FHH.PCK and SS.PCK but not SD.PCK, suggesting the presence of common genetic modifiers of ARPKD. Collectively, these data provide 5 novel candidate modifiers of ARPKD risk for mechanistic follow‐up.
Elevation of glucose to levels associated with type I diabetes impairs bone cell mechanosignaling (1180.10)
Authors: Maung Stephanie , Wang Xiaonan , Basta‐Pljakic Jelena , Schaffler Mitchell , Spray David , Suadicani Sylvia , Thi Mia
Published: June 2021

It has been shown that patients with insulin dependent diabetes mellitus (IDDM; Type 1 diabetes) manifest a range of bone problems, including increased risk for bone fractures and defective bone healing. However, the underlying mechanisms are still not well understood. Given that the maintenance of skeletal integrity in response to daily physical activity relies homeostasis between bone forming cells, osteoblasts, and the primary load sensing cells, osteocytes, we hypothesized that bone loss in Type 1 diabetes is primarily triggered by exposure to high glucose levels which in turn compromises ability of bone cells to perceive and respond to mechanical loading as a result of altered expression of mechanosignaling mediators: specific purinergic receptor (P2Rs) and pannexin 1 (Panx1) channels. Our in situ (Akita, Type 1 diabetic and age‐matched wild type mouse model) morphometric analysis and in vitro (MLO‐Y4 osteocytes and MOB‐C osteoblasts) findings indicate that exposure to elevated glucose (10 days in α‐MEM containing 450 mg/dL (25 mM) glucose) alters P2R (specifically P2Y2R, P2Y4R and P2X7R) and Panx1 expression in both osteoblastic and osteocytic cells and blunts proper Ca2+ signaling in response to oscillatory fluid shear stress mechanical loading. Our findings indicate that Type 1 diabetes impairs the proper response of bone cells to mechanical loads, which is required to maintain bone health.

Grant Funding Source: Supported by DK091466; DK081435; AR057139
Epithelial cell modeling: standards‐based simulation experiments (1180.4)
Authors: Nickerson David , Hamilton Kirk , Beard Daniel , Hunter Peter
Published: June 2021

We have developed a simulation tool, get‐simulator, for performing simulation experiments with user‐defined epithelial cell models. Users are able to define their epithelial cell model de novo or through the assembly of pre‐existing modules. Existing cell models may also be re‐used in new simulation experiments. Cell models are encoded in the CellML format (http://cellml.org) and the SED‐ML format (http://sed‐ml.org) descriptions of the simulation experiments. SED‐ML allows a given collection of models to be instantiated into one or more specific computational tasks to be executed in order to generate unambiguously defined outputs. In addition to the models and simulation experiment descriptions themselves, get‐simulator makes use of relevant annotations of these source data to enable the automatic generation of executable code for each of the required computational tasks. Following the execution of these tasks, the user is presented with the resulting outputs defined in the SED‐ML document. get‐simulator and example models are available from https://bitbucket.org/get under a free and open‐source license.

Grant Funding Source: Supported by the Virtual Physiological Rat Project, NIH grant [P50‐GM094503].
The consumption of beef vs. soy lunch meals on food cravings and cortico‐limbic brain regions controlling food motivation/reward in healthy adults (120.5)
Authors: Ortinau Laura , Lasley Tyler , Douglas Steve , Shafer Rebecca , Leidy Heather
Published: June 2021

Objective: To determine whether protein source, specifically comparing beef vs. soy‐rich foods, alters food cravings and neural responses controlling food motivation and reward in healthy adults. Methods: Using a randomized, crossover design, 23 healthy adults (age 23 ± 1 y; BMI: 23.4 ± 0.6 kg/m2) consumed, on separate days, 400 kcal beef vs. soy‐based lunch meals that were 1) matched for macronutrient and fiber content or 2) matched for serving size (which allowed macronutrient and fiber content to vary). Pre and post‐lunch food craving questionnaires and food cue‐stimulated functional MRI (fMRI) brain scans were completed. Results: When comparing macronutrient and fiber‐matched meals, the consumption of beef tended to reduce post‐lunch cravings for sweet foods vs. soy (P=0.09) and tended to reduce hippocampal brain activation vs. soy (P=0.08). When comparing serving size‐matched meals, the consumption of beef tended to reduce post‐lunch cravings for sweet foods vs. soy (P=0.08) and reduced anterior cingulate and insular brain activation vs. soy (both, P<0.05). Conclusions: Taken together, these data suggest that protein source significantly alters the signals that control food cravings and reward with the consumption of beef‐rich foods leading to greater reductions in sweet cravings and cortico‐limbic activation in regions controlling food motivation/reward compared to soy‐rich foods.

Grant Funding Source: Supported by The Beef Checkoff
Effect of dietary resistant starch on the inhibition of preneoplasia in azoxymethane‐induced A/J mouse model (123.5)
Authors: Birt Diane , Nelson Bridget , Cray Nicole , Ai Yongfeng , Jane Jay‐Lin
Published: June 2021

Colorectal cancer (CRC) occurrence is believed to be affected by diet and lifestyle factors. Resistant starch, a type of dietary fiber, is resistant to normal digestion in the small intestine and is instead available for fermentation in the larger intestine by gut microbes. Four starches, varying in digestibility resistance, were used: normal control cornstarch (CS), native high amylose cornstarch (HA7), high amylose complexed with octenyl succinic anhydride (OS‐HA7), and high amylose complexed with stearic acid (SA‐HA7). Preneoplastic lesions were induced in male A/J mice with azoxymethane (AOM), a known colon carcinogen, and saline was used as a control. Treatment groups of mice were fed one of the experimental diets for 10 weeks. Colons were collected and analyzed for common preneoplastic lesions aberrant crypt foci (ACF) and mucin‐depleted foci (MDF). It was hypothesized that the SA‐HA7 diet would provide the greatest inhibition of preneoplasia as it contained the greatest resistant starch content, allowing for greater fermentation and greater production of SCFA. Body weights were recorded weekly. The saline and AOM treated, OS‐HA7 fed mice were not significantly different in body weights at any week. The OS‐HA7‐AOM group, however, was significantly different from all other groups at weeks 7, 12, and 17. The mice fed the SA‐HA7 diet actually had the greatest number of ACF compared to the other diet groups. The HA7 diet had the lowest number of ACF but was not significantly different from the SA‐HA7 diet (p=0.09). No MDF were observed in any of the diet groups. The results from this study suggest that the SA‐HA7 diet may enhance preneoplasia rather than inhibit it if ACF are reliable biomarkers for CRC. Long term studies are needed to determine the impact of resistant starch on CRC.

Grant Funding Source: supported by USDA‐AFRI
Improvement of learning and memory by sprouted garlic extract through antioxidant activity in mouse model (124.8)
Authors: Zakharova Alexandra , Seo Ji Yeon , Kim Seong Soon , Kang Hye Ryung , Kim Bo Ram , Woo Ji Eun , Kim Mi Hye , Han Mi Kyung , Kim Jong‐Sang
Published: June 2021

Garlic is known for its biological function including anticancer, antioxidant, anti‐inflammation and anti‐bacterial activities. This study was conducted to examine comparatively neuroprotective and memory improving effects of sprouted garlic extract and garlic extract. Garlic was sprouted for 1, 2, 3, 4, 5, 6 days and extracted with 100% ethanol. The antioxidant activity of sprouted garlic extract was assessed by various in vitro assays. The effect of sprouted garlic extract on intracellular ROS levels and cell viability were measured in murine hippocampal HT22 cells. Sprouted garlic extracts showed cytoprotective effect, and reduced intracellular ROS levels in the cells insulted with glutamate. Based on these results, we were interested in examining if sprouted garlic extract prevents the scopolamine‐induced memory impairment in mice, using Y‐maze, Morris water maze and passive avoidance tests. The current study demonstrated that sprouting of garlic enhanced the antioxidant activity depending on the period, with the highest activity at 5 days of sprouting. Additionally, our data indicated that sprouted garlic treatment was effective in improving the memory and cognition deficits triggered by scopolamine treatment. Henceforth, further mechanism study of sprouted garlic extracts would be needed.

Grant Funding Source: Supported by NRF‐2010‐0027204 and 2011‐0009782 and IPET (High Value‐added Food TechnologyDevelopment Program, 2012, 112066‐3), S. Korea
Does adult weight scale as height squared? An across gender and race‐ethnicity analysis (130.1)
Authors: Heymsfield Steven , Thomas Diana , Peterson Courtney , Heo Moonseong , Hong Sangmo , Choi Woong
Published: June 2021

A key and often‐challenged BMI assumption is that weight (W) scales to height (H) squared across men, women, and all race‐ethnic groups. This hypothesis was tested in similarly conducted US and Korean HANES studies that included 7309 men and 6204 women with complete DXA scans for %fat and regional body mass (head, trunk, arms, legs), and who were non‐Hispanic (NH) white, NH black, Mexican American, or Korean. Gender and race/ethnicity‐specific H powers were derived with log(W) as allometric regression model dependent variable and log(H) as independent variable with adjustments for log(age) and log(%fat). H powers (±SE; table) all centered around 2.0; no significant sex‐race/ethnicity differences in H powers were present at a 2‐sided 0.05 significance level. Relative to W, regional mass H powers scaled in the sequence: legs (~2.2) > arms (~1.9) & trunk (~2.0) > head (~0.8). W thus scales very close to 2.0 across men, women, and the evaluated race/ethnicity groups and reflects the weighted scaling of different body regions. Weight adjusted for H2 is an appropriate means of adjusting W for between‐individual H differences regardless of gender or race/ethnicity.

H Powers

H Power±SE
NH White
NH Black
Mex Am
Korean

Men
1.97±0.08
2.03±0.15
2.16±0.12
1.96±0.04

95% CI
1.81‐2.14
1.74‐2.32
1.86‐2.35
1.88‐2.04

Women
2.12±0.08
2.19±0.14
2.10±0.10
2.09±0.05

95% CI
1.97‐2.26
1.92‐2.46
1.90‐2.30
2.00‐2.19
TRPM5 is a target in the modulation of taste perception and insulin secretion (133.4)
Authors: Philippaert Koenraad , Vennekens Rudi
Published: June 2021

TRPM5 is a monovalent cation selective ion channels, activated by an increase of the intracellular Ca2+ concentration. Physiologically, TRPM5 is a key player in the transduction of taste signals and plays a role in the release of insulin from pancreatic ß‐cells. To date no pharmacological tools are available to evaluate the potential of TRPM5 as drug target for taste modulation or as insulin secretagogue. Here we show that the TRPM5 ion channel has potential as a target to stimulate insulin secretion in a mouse model We present a new class of compounds capable of potentiating TRPM5 signaling and analyze their working mechanism. We show activation of TRPM5 in a heterologous overexpression system and in a murine animal model. We show potentiation of sweet and bitter taste in a TRPM5 dependent way, using a two bottle preference test. Furthermore we observe increased glucose induced activity in the insulin secreting islets of Langerhans upon perfusion with our activator. These effects were completely abolished in TRPM5 knock‐out mice. In the high fat fed mouse, a model for type II diabetes, we showed that activating TRPM5 with our compound allows them to maintain a healthier glucose metabolism and delays the development of diabetes.
Metabolic syndrome in TLR5 deficient mice is associated with microbiota dependent MUFA enriched hepatic lipids (133.6)
Authors: Chassaing Benoit , Kumar Manish , Gewirtz Andrew , Vijay‐Kumar Matam
Published: June 2021

Obesity (leptin deficiency) is associated with elevated monounsaturated fatty acids (MUFA) specifically palmitoleate (C16:1) and oleate (C18:1) in tissue neutral lipids. Toll Like Receptor 5 (TLR5), an innate immune receptor for bacterial flagellin is required for gut microbiota homeostasis. Accordingly, mice lacking TLR5 (TLR5KO) develop spontaneous low‐grade gut inflammation and metabolic syndrome, which are microbiota dependent. Here, we examined whether metabolic syndrome in TLR5KO mice is associated with elevated MUFA levels. We analyzed fatty acid composition of total lipid (TL), triglycerides (TG), cholesterol esters (CE) and phospholipid (PL) fractions of the tissue lipids in age and gender matched TLR5KO and their WT littermates. We also analyzed MUFA levels in high‐fat fed, TLR2 or 4 deficient TLR5KO, calorie restricted, microbiota ablated, germ‐free (GF) and conventionalized GF‐WT mice transplanted with either WT or TLR5KO microbiota. TLR5KO mice displayed elevated hepatic TG and CE and substantially elevated C18:1 in TL, TG and CE but not in PL when compared to WT mice. Interestingly, in TLR5KO mice C16:1 levels were comparable to WT mice. Such elevated C18:1 was restricted to hepatic lipids and not in serum and adipose tissue lipids. The elevated C18:1 was also observed in high fat fed and calorie restricted TLR5KO mice. In addition, deletion of TLR2/4 did not prevent accumulation of C18:1 in TLR5KO mice hepatic lipids. However, in microbiota‐ablated (via antibiotics) as well as GF TLR5KO mice, C18:1 levels were comparable to WT mice. Finally, the pronounced C18:1 accumulation in hepatic lipids was recapitulated in GF‐WT mice transplanted with microbiota from TLR5KO mice than WT microbiota recipients. Collectively, these data demonstrate that gut microbiota dysbiosis in TLR5KO mice drives hepatic lipogenesis probably via generating precursors for MUFA (short chain fatty acids) that may result in hepatic insulin resistance finally culminating into metabolic syndrome.

Grant Funding Source: NIH K01 and R03
Skeletal muscle fat accumulation and increased fatty acid saturation are related to worsening glucose control in older adults (133.8)
Authors: Dunville Keagan , Kim Jung Eun , Li Junjie , Conley Travis , Cheng Ji‐Xin , Talavage Thomas , Couture Cortni , Campbell Wayne
Published: June 2021

Increased inter‐muscular adipose tissue (IMAT) content and intra‐myocellular lipid (IMCL) fatty acid saturation (FAS) are implicated in insulin resistance (IR), but potential relationships require further investigation because of limited data. This study examined the associations between IMAT content, IMCL FAS, and fasting plasma glucose concentrations in 10 men and women, age range 65‐76 y, plasma glucose 101±11 mg/dL (range 87‐114 mg/dL). Thigh muscle and adipose tissue volumes (magnetic resonance imaging) and the FAS of vastus lateralis IMCL (from muscle biopsies using Coherent Anti‐scattering Raman Spectroscopy and Spontaneous Raman Spectroscopy) were quantified. IMAT volume, standardized with respect to muscle tissue volume (ratio 0.10±0.02), was positively correlated with the ratio of saturated to unsaturated fatty acids in IMCL (r=0.709, p=0.02). IMAT volume and IMCL FAS were both positively associated with plasma glucose concentration (β=300.6, p=0.02, and β=105.4, p=0.02, respectively). These results suggest that inter‐muscular fat accumulation and increased myocellular fatty acid saturation are related to each other and both may contribute to worsening glucose control.

Grant Funding Source: Supported by NIH UL1 TR000006, Purdue Ingest Behav Res Ctr, Amer Egg Board, Dairy Res Inst
TGFβ activates insulin‐like growth factor 1‐mediated signaling pathway in human liver cancer cells (144.9)
Authors: Ungerleider Nathan , Han Chang , Wu Tong
Published: June 2021

Transforming growth factor β (TGFβ) potently inhibits the growth of human epithelial cells. However, neoplastic epithelial cells become resistant to TGFβ‐mediated mitoinhibition, and the mechanisms for this alteration during tumorigenesis are not fully understood. In this study, we demonstrate that TGFβ sensitises PLC/PRF/5 cells (Human hepatocellular carcinoma cell line) to insulin‐like growth factor 1 (IGF1), and enhances cell survival in the presence of sorafenib, a therapeutic agent used to treat advanced stage HCC. Firstly, we observed that TGFβ significantly increased mRNA and protein expression of insulin like growth factor 1 receptor (IGF1R) in PLC cells. To test how this result would affect IGF1 signaling, PLC cells were treated with TGFβ for up to 72 hrs, then treated with IGF1 for 30 min. PLC cells pretreated with TGFβ had a much greater response to IGF1 treatment, exhibiting significantly increased levels of pIGF1R and pAkt compared with IGF1 treatment only. Since IGF1 is a pro‐survival mitogen, we further tested whether an increase in IGF1 sensitivity would reduce apoptosis in the presence of sorafenib. The cells were treated with TGFβ for 48 hrs before the incubation with sorafenib for up to 24 hrs. We found that TGFβ pretreatment led to a significant reduction in both cleaved caspase 7 and cleaved PARP, and a significant increase in cell viability compared with sorafenib treatment only. Taken together, our data suggest that TGFβ can regulate the survival of HCC cells via the activation of IGF1 pro‐survival pathway and prevent Sorfafenib‐induced apoptosis.

Grant Funding Source: NIH/NCI
Endothelial cell IQGAP1 is an important regulator of the transendothelial migration of leukocytes (146.1)
Authors: Sullivan David , Muller William
Published: June 2021

In order to mount an appropriate inflammatory response, leukocytes must cross the endothelium to gain access to the target tissue and carry out their essential role. During this process (referred to as transendothelial migration, TEM) membrane from a novel endothelial cell compartment, the Lateral Border Recycling Compartment (LBRC), is delivered to the migrating leukocyte to supply it with several requisite proteins. In a proteomic screen, we discovered that IQGAP1 is associated with the LBRC and is required for its function during TEM. IQGAP1 is a large soluble scaffolding protein that integrates signals from diverse pathways to regulate cytoskeletal remodeling, Rho family GTPase activity, and other downstream readouts. Although it has been implicated in a variety of processes in other systems, its role in TEM remains unclear. In addition to being localized to the cytoplasm, in endothelial cells it is also enriched at lateral borders. Genetic ablation of IQGAP1 expression arrests leukocytes on the apical side of endothelial cells and prevents the targeted delivery of the LBRC similar to the phenotype of blocking PECAM. Expression of a full length GFP‐tagged IQGAP1 construct completely restores this defect and also shows that endothelial IQGAP1 is enriched around the leukocyte during TEM. Furthermore, using fluorescently tagged IQGAP1 truncation constructs, we have identified the domains of IQGAP that are required for its localization and function under resting conditions and during TEM. These data suggest that IQGAP1 is an important factor in the regulation of LBRC function. Preliminary studies in IQGAP1 knockout mice support a role for IQGAP in TEM in vivo.

Grant Funding Source: Supported by F32 AI084454 to DPS and R21 HL102519, R01 HL046849, and R37 HL064774 to WAM
Regulation of cardiac fibroblast population and cell fate by Scleraxis (15.2)
Authors: Bagchi Rushita , Roche Patricia , Aroutiounova Nina , Schweitzer Ronen , Czubryt Michael
Published: June 2021

Fibroblasts are cells of mesenchymal origin that constitute majority of the cardiac non‐myocyte population. They play a contributory role in development and structure of the myocardium, cellular signaling and electromechanical function of the heart‐ both in healthy and diseased conditions. Scleraxis (Scx) has been demonstrated to play a vital role in human collagen gene regulation and synthesis of extracellular matrix (ECM) components. Genetic ablation of Scx caused marked changes in the matrix composition of hearts of Scx null (KO) mice. Based on these observations, we hypothesized that the overall changes occurring in the myocardium may be due to a net change in population of the contributory synthetic fibroblasts. Using single‐cell suspensions from Scx KO and wildtype (WT) hearts, flow cytometry analysis was performed. There was a significant reduction (>40%) in DDR2 positive fibroblasts in Scx KO hearts compared to WT samples. There was also a trending decrease in the population of cells that stained positive for α‐smooth muscle actin (αSMA), a marker of activated contractile myofibroblast phenotype. Gene and protein expression analyses of fibroblast/ myofibroblast markers (vimentin, periostin, EDA‐fibronectin, SMemb) exhibited an overall downregulation of these proteins in myocardium devoid of Scx‐ thus suggesting involvement of Scx in fibroblast cell fate regulation. We hypothesized that Scx may also be responsible for modulating the process of fibroblast phenoconversion‐ a phenomenon that is known to accompany cardiac remodeling. qPCR and immunoblotting analyses of Scx KO hearts demonstrated a significant downregulation of αSMA expression. shRNA‐mediated knockdown of Scx gene expression in primary cardiac proto‐myofibroblasts resulted in marked diminution of this myofibroblast marker protein, thereby demonstrating a direct role of Scx in fibroblast phenoconversion. These findings identify Scx as a novel regulator of cardiac fibroblast population and cell fate.

Grant Funding Source: Supported by the Canadian Institutes of Health Research and St. Boniface Research Foundatio
Efferocytosis ő autophagy crosstalk in alveolar macrophages exposed to cigarette smoking (151.7)
Authors: Petrusca Daniela , Van Demark Mary , Hubbard Walter , Twigg Homer , Petrache Irina
Published: June 2021

Alveolar macrophages (AM) apoptotic cell clearance function (efferocytosis) is dysregulated in COPD due to cigarette smoke (CS) exposure via production of ceramides and sphingosine (SHP). CS also alters the maturation of the autophagosomes (AP) blocking the autophagic flux. We hypothesized that impairment of both AP maturation and efferocytosis share an identical mechanism of cytoskeletal derangement linked to HDAC6 inactivation and sphingosine accumulation. AM obtained via bronchoalveolar lavage from human smoker and non‐smoker donors or from Sprague Dawley rats exposed to CS (3 months) were subject to engulfment assays quantified by flow cytometry. HDAC6 was evaluated by real‐time PCR or Western blot. Both CS and SPH significantly impaired efferocytosis in rat and human AM (50% and 80% inhibition; p<0.05, respectively). HDAC6 protein activity was markedly impaired by CS exposure. This effect was in part mediated by SPH production, since a ceramidase inhibitor, MAPP, restored both HDAC6 levels and improved autophagic flux. Moreover, HDAC6 inhibition with BML‐281 or siRNA significantly impaired efferocytosis, as well as bafilomycin treatment, an inhibitor of AP maturation (by up to 7‐fold; p<0.05). Whole protein HDAC6 overexpression significantly restored the efferocytosis impairment induced by CS but overexpression of the HDAC6 catalytic mutant did not. These results indicate a novel role of HDAC6 in efferocytosis. The impairment of both autophagic flux and efferocytosis may be mechanistically linked at the level of sphingolipid regulation of cytoskeletal effectors activity such as HDAC6. Improvement in AP maturation may help restore efferocytosis, an essential step in the resolution of pulmonary inflammation.

Grant Funding Source: ALA RG‐1966666‐N and NIH‐HL077328
A novel approach to investigate the assembly of the NOD‐like receptor inflammasomes (152.7)
Authors: Giles Nichole , Sierecki Emma , Polinkovsky Mark , Schroder Kate , Alexandrov Kirill , Gambin Yann
Published: June 2021

The NLRP3 and NLRP12 inflammasome complexes are a subset of the Nod‐like receptor family, known to play a key role in the innate immune system. They act by activating caspase‐1 in response to pathogens, as well as endogenous and environmental stimuli. The NLRP3 inflammasome consists of the sensing protein, NLRP3, adaptor protein ASC, and pro‐caspase‐1. The proposed structure of the complex is based on the effector domains on the proteins, although the assembly of the active complex remains unclear. Even less is known about the NLRP12 inflammasome.

We used a combination of Leishmania tarentolae cell‐free expression system, AlphaScreen, and single molecule fluorescence spectroscopy to investigate the assembly of NLRP3 and NLRP12 inflammasomes. Our results suggest that the NLRP3 and NLRP12 inflammasomes have different mechanisms of assembly. We observed NLRP3 and NLRP12 forming oligomers of distinct size. While NLRP3 can bind to ASC and pro‐caspase‐1 independently, association of NLRP12 with pro‐caspase‐1 requires ASC. Interestingly, we observed that aggregation of ASC is concentration dependent and nucleation of ASC has characteristics of the seeding model proposed for prions.

Grant Funding Source: Australian Research Council
Development of lifelong learning strategies using inquiry guided learning projects in a first year anatomy course (211.6)
Authors: Bentley Danielle
Published: June 2021

Biomedical science courses are often crammed with mandatory content. As a result, students may develop passive learning strategies; relying on the instructor to ‘give them’ knowledge. For instance, students self‐report (pre‐semester survey, 10‐pt Likert) a lack of confidence in the exploration of research on a scientific topic (6.4 ± 1.1) outside of formal instruction. To evade this passivity and to promote lifelong learning strategies, Inquiry Guided Learning Projects (IGLPs) have been developed for first year Gross Anatomy; piloted in 2012, then evaluated/reformatted and integrated in 2013. Aligned with student desires to develop skills in effective communication (8.1 ± 1.8) and resource acquisition (8.5 ± 1.9) IGLPs facilitation include 4 novel Information Sessions and 3 Check‐Ins that guide students through the Information Search Process (ISP); initiation, selection, exploration, formulation, collection, and presentation. The guiding aspect was imperative, as students indicate poor self‐perceived abilities of research question selection (6.6 ± 1.7), answer exploration using peer‐review literature (6.4 ±1.2), and effective scientific communication (6.3 ± 1.5). The effect of IGLPs on change over time in student‐perceived confidence and self‐reported ability in all ISP stages will be tested with a repeated measures ANOVA. IGLPs prepare students to be active learners; confident in their ability for academic discovery following formal education.

Grant Funding Source: Supported by CIHR CGS Doctoral Research Award
An unexpected nucleolar role for FGFR2 in development and disease (213.4)
Authors: Merrill Amy , Neben Cynthia , Idoni Brian , Salva Joanna , Tuzon Creighton , Rice Judd , Krakow Deborah
Published: June 2021

Numerous skeletal birth defects arise from mutations in genes that regulate when and where osteoprogenitor cells transition from a proliferative state to one of terminal differentiation during development. Fibroblast Growth Factor Receptor 2 (FGFR2), whose mutations cause 10 distinct skeletal disorders, is one such regulator. While FGFR2 promotes both proliferation and differentiation in osteoprogenitor cells, how the receptor executes and links these opposed activities remains unclear. Our analysis of Bent Bone Dysplasia Syndrome (BBDS), a FGFR2‐disorder with excess osteoprogenitor cells and insufficient osteoblasts, has identified a nucleolar role for FGFR2 that can resolve this paradox. The unique FGFR2 mutations in BBDS enhance receptor localization to the nucleolus where it interacts with UBF1 at the ribosomal RNA promoter to activate transcription by repressing Runx2. Transcription of rRNA is the rate‐limiting step in producing ribosomes, which are the protein producing machines in all cells. A cell’s proliferative potential relies on protein synthesis and thus during differentiation lineage specific transcription factors, such as Runx2, arrest progenitor cell proliferation by inhibiting rRNA transcription. That nucleolar FGFR2 regulates transcription of Runx2 target genes suggests a novel mechanism through which the receptor links osteoprogenitor proliferation to differentiation.
Towards enhanced understanding of protein folding in the cell (219.1)
Authors: Gierasch Lila
Published: June 2021

Major challenges arise when we attempt to apply lessons from study of protein folding in vitro to folding of a protein in vivo where conditions are very different from high‐dilution test tube experiments. Strikingly, proteins generally fold successfully in vivo, even at concentrations higher than the threshold for aggregation, because the protein homeostasis network, including chaperones and degradation machinery, facilitates folding under cellular conditions. This talk will describe two aspects of the function of the protein homeostasis network: 1) Using primarily NMR, we have studied the allosteric mechanism of the Hsp70 chaperone family and found that nucleotide‐dependent substrate affinity is a consequence of ligand‐modulation of domain conformational ensembles. 2) We are exploring how the E. coli protein homeostasis network modulates protein folding. Predictions from our computational model, FoldEco (Powers et al., Cell Reports 1, 265 [2012]), are being tested experimentally. Up‐regulation of the protein homeostasis network benefited several test proteins, as did enhanced expression of the Lon degradation enzyme. Over‐expression of individual chaperones had substrate‐dependent effects. These results suggest that the cell handles the folding load of the proteome by concerted action of the proteostasis network.

Supported by NIH grants GM027616 and GM101644.
A biochemist’s journey to bioanalytical and traditional analytical chemistry (233.3)
Authors: Rohrer Jeffrey
Published: June 2021

This presentation describes a post‐doc biochemist’s journey to a 25 year career in the world of analytical instrumentation. The speaker reviews his career assumptions entering graduate school and his post‐doctoral position, and examines the personal factors that started him on his ultimate career path. The many roles that biochemists fill in analytical instrumentation companies will be described as well as the reasons that the speaker feels that biochemists often fill these roles better than other chemists. In addition to reviewing the jobs he has held during his career, the speaker will reflect on what he learned in graduate school and during his post‐doctoral position that has allowed him to be successful.