bluuebunny/crossref_metadata_2025 huggingface dataset:
Almond Form and Processing Impacts Metabolizable Energy Value in Humans
Authors: Baer David J , Gebauer Sarah K , Novotny Janet A
Published: June 2021

We have previously demonstrated that the metabolizable energy (ME) of whole roasted almonds is less than that predicted by the Atwater factors, and thus lower than the value currently listed on the Nutrition Facts panel. Studies have shown that incomplete disruption of the cell wall during mastication of whole almonds leads to decreased lipid absorption, suggesting that the food matrix plays a role in determining the ME value of a food. However, data are lacking on how food structure and processing (roasting, slicing or grinding) impact the ME value of almonds. The objective of this research was to determine the ME value of different forms of almonds.

We conducted a randomized, crossover design study in healthy individuals (n = 18) to measure the ME of the following forms of almonds, within the context of a completely controlled diet (18 days each): whole, natural almonds (42 g/day); whole, roasted almonds (42 g/day); diced almonds (42 g/day); almond butter (42 g/day); and control (0 g/day). After 9 days of adaptation to each diet, participants collected all urine and fecal samples for approximately 9 days. The gross energies of the diets, almonds, urine, and feces were measured by adiabatic bomb calorimetry. The ME value of the nuts was determined using the paired‐diet approach.

Based on the measured chemical composition of the almonds fed, the estimated ME (kcal/g) by use of Atwater specific factors for whole natural almonds, whole roasted almonds, diced almonds, and almond butter was 5.91, 6.01, 6.04, and 6.18, respectively. The empirically measured ME value (kcal/g) for whole natural almonds, whole roasted almonds, and diced almonds was 4.42, 4.86, and 5.04, significantly lower than predicted (P < 0.001 for all); while the ME for almond butter was similar to predicted (6.53 kcal/g; P = 0.08). Available calories from almonds is dependent on the form in which they are consumed. Furthermore, the measured ME of whole natural almonds, whole roasted almonds, and diced almonds is significantly lower than that estimated by the Atwater factors (30.4%, 24.5%, and 22.1%, respectively).

Atwater factors (general or specific) provide inaccurate estimates of ME for almonds whether they are consumed whole, whole roasted, or chopped, whereas they are accurate for butter. It is likely that estimates of macronutrient digestibility used to develop the Atwater factors are incorrect for nuts.

Support or Funding Information

USDA and Almond Board of California
MicroRNAs as a Novel Mechanism by which Eicosapentaenoic Acid Mediates Inflammation in Diet‐Induced Obesity
Authors: Yen Erin , Wijayatunga Nadeeja , Pahlavani Mandana , Ramalingam Latha , Kottapalli Kameswara Rao , Kalupahana Nishan Sudheera , Gunaratne Preethi , Rajapakshe Kimal , Coarfa Cristian , Dharmawardhane Suranganie , Moustaid‐Moussa Naima
Published: June 2021

Obesity is associated with the expansion of adipose tissue that creates a system in which the body transitions into a prothrombotic and inflammatory state. This is in part due to an imbalance between reduced levels of anti‐inflammatory and increased levels of pro‐inflammatory adipokines secreted from adipose tissue, resulting in a chronic, low‐grade inflammation in adipose tissue. Previous studies from our laboratory have demonstrated that C57BL/6J mice fed high fat diets supplemented with the omega‐3 fatty acid eicosapentaenoic acid (HF‐EPA) exhibited lower adipose and systemic inflammation and macrophage infiltration into white adipose tissue compared to mice fed high fat diets without EPA supplementation (HF). To further dissect mechanisms mediating effects of EPA on adipocyte inflammation, we tested whether EPA regulates specific inflammatory genes (RNA‐Seq with Illumina® HiSeqTM) and microRNAs (miRNA profiling with Illumina® MiSeqTM) in visceral white adipose tissue (VAT) of mice. We identified 200 genes and 64 miRNAs that were differentially expressed (95% confidence and p<0.05) in VAT from two groups of mice fed either a HF or HF‐EPA diet for 11 weeks. QIAGEN's Ingenuity® Pathway Analysis (IPA®) was used to characterize mRNA‐miRNA pairs that were regulated by EPA. Among these, the proinflammatory miR‐221‐3p, a key miRNA determined by IPA® to be associated with diabetes mellitus, was found to be down regulated by EPA. Nuclear factor kappa B (NF‐κB), pattern recognition receptors (PRR), and nuclear factor of activated T‐cells (NFAT) pathways were among the major canonical pathways that were reduced by EPA in VAT. Moreover, expression of lipopolysaccharide (LPS), interferon gamma (INFγ), and transforming growth factor alpha (TGF‐α) were also significantly reduced in VAT of HF‐EPA compared to HF diets. We further confirmed by quantitative reverse transcription polymerase chain reaction that EPA significantly reduced miR‐221 expression by 3‐fold in VAT (p<0.05). In future studies, we will conduct mechanistic experiments in cultured adipocytes treated with saturated fatty acids (to mice HF diets) and with or without EPA to confirm miRNAs and target genes regulated by these fatty acids, using miRNA mimics and inhibitors. We conclude that global genomic studies are valuable approaches to identify new pathways regulated by omega‐3 fatty acids that may pave the way for novel targets to prevent/treat metabolic complications associated with obesity and inflammation.

Support or Funding Information

Funding Support: USDA NIFA Grant # 11672117 and startup funds from Texas Tech University
Plasma Metabolite Profiles in Ethiopian Women following Zinc Supplementation
Authors: Barton‐Wechsler Silena , Atwell Lauren L , Bogale Alemtsehay , Choi Jaewoo , Nkrumah‐Elie Yasmeen , Stoecker Barbara , Ho Emily
Published: June 2021

Zinc is an essential mineral involved in many aspects of human health. Yet, information on the health impacts of marginal zinc deficiency is limited due to a lack of a sensitive, reliable biomarker for measuring zinc status. Previous studies have shown that serum zinc, the most commonly utilized human biomarker, does not adequately reflect zinc intake. The use of metabolomics is an emerging tool that has shown promise in biomarker discovery. A recent metabolomics analysis in Drosophila found several citric acid cycle intermediates were upregulated following zinc supplementation, but similar studies in humans are limited. The objective of this study is to identify endogenous metabolites associated with changes in zinc nutriture in humans using a novel, global (untargeted) metabolomics analysis. In a randomized, placebo‐controlled clinical trial, Ethiopian women (n=24) consuming low levels of zinc were supplemented with 20 mg zinc sulfate for 23 days. Plasma samples were obtained before and after supplementation (day 0 and day 23) for metabolomics analysis, metabolite quantification, and pathway validation. Preliminary analyses revealed significant differences in plasma metabolite profiles before and after zinc supplementation. Next steps involve identification and validation of endogenous metabolites as well as identification of associated biochemical pathways. Additional experiments will be conducted in vitro to investigate alterations in these biochemical pathways, including the citric acid cycle. These studies will provide information for novel functions of zinc and aid in characterizing a sensitive, reliable biomarker or biomarker panel for assessing zinc status in humans.

Support or Funding Information

USDA AES multistate W3002
Systemic Effects of AT‐121 as a Safe Analgesic without Abuse Liability in Primates
Authors: Ding Huiping , Kiguchi Norikazu , Czoty Paul , Nader Michael , Zaveri Nurulain , Ko Mei‐Chuan
Published: June 2021

AT‐121 is a newly developed bifunctional nociceptin/orphanin FQ peptide (NOP)/mu opioid peptide (MOP) receptor agonist that displays full efficacy on NOP receptors and partial efficacy on MOP receptors. The aim of this study was to establish the functional profile of AT‐121 as an analgesic by using several behavioral and physiological assays in rhesus monkeys (Macaca mutatta). Systemic administration of AT‐121 (0.003–0.03 mg/kg) dose‐dependently produced antinociceptive and antihypersensitive effects. Both NOP receptor antagonist J‐113397 (0.1 mg/kg) and MOP receptor antagonist naltrexone (0.03 mg/kg) equally attenuated AT‐121‐induced antinociception. These antagonist studies demonstrate that both NOP and MOP receptor components contribute to the antinociceptive effects exhibited by AT‐121 in primates. More importantly, a full antinociceptive dose (0.03 mg/kg) and a dose 10‐fold higher (0.3 mg/kg) of AT‐121 did not affect physiological functions including respiration, cardiovascular activities, and body temperature as measured by the telemetry probes (DSI, model D70‐PCTR). These findings indicate a wider therapeutic window afforded by AT‐121 as compared to MOP receptor agonists. In addition, AT‐121 did not produce reinforcing effects in monkeys under the progressive‐ratio schedule of drug self‐administration. Following repeated administration of AT‐121, monkeys did not show physiological withdrawal signs precipitated by both NOP and MOP receptor antagonists. Taken together, these translational nonhuman primate studies demonstrate that AT‐121 is an effective and safe analgesic without typical opioid‐associated side effects. Lack of reinforcing effects and acute physical dependence by AT‐121 strongly supports the therapeutic potential of selected bifunctional NOP/MOP agonists as innovative analgesics in humans.

Support or Funding Information

Supported by the US‐PHS grants DA‐032568 and DA‐035359 and the US‐DOD grant W81XWH‐13‐2‐0045.
ATP‐binding cassette (Abc) transporters and cytoprotective genes respond differentially to a hepatotoxic dose of acetaminophen in male and female mouse brain
Authors: Flores Katiria M , Renfro J Larry , Manautou Jose
Published: June 2021

The choroid plexus (CP) or blood‐cerebrospinal fluid barrier (BCSFB) and blood‐brain barrier (BBB) control the movement of drugs and metabolites between the brain and systemic circulation. Gender differences in drug excretion and detoxification mechanisms can affect therapeutic and toxic responses. For example, male mice are more susceptible to acetaminophen (APAP) induced hepatotoxicity. The Abc transporters and one of their transcription factors, nuclear factor erythroid‐2‐related factor (Nrf2), play roles in the susceptibility to APAP induced hepatotoxicity. Our aim was to examine gender differences in expression of Abc transporters, Nrf2 and related stress genes (NAD(P)H quionine oxidoreductase‐1, Nqo1, and heme oxigenase‐1, Ho‐1) in the brain and CP. We hypothesized that hepatic/renal gender‐specific patterns of these cytoprotective genes would also be present in the blood brain interfaces. In female mice, as compared to male, Abcc1‐2 and Abcc4 transporters are more strongly expressed brain, supporting our hypothesis. qRT‐PCR analysis revealed higher expression of Abcc1‐2 and Nrf2 in the female brain, but no differences in the CP. Abcc4, Ho‐1 and Nqo1 showed higher expression in female in both brain interfaces. These differences may contribute to APAP potential for neurotoxicity. We examined the differences in mRNA expression of cytoprotective genes at the brain interfaces of WT and Nrf2−/− mice following a hepatotoxic dose of APAP (400 mg/kg). APAP enhanced the expression of Abcc2 and Abcc4 in brains of male WT mice, but reduced the expression of these transporters in male Nrf2−/− mice. No changes were observed in the brains of either genotype of female mice. These data suggest that the expression of these transporters in the female mouse brain are not altered by a hepatotoxic dose of APAP and that transcription factors other than Nrf2 may be responsible for the regulation of Abc transporters in the female brain.

Support or Funding Information

Supported by NSF and NIH
Protein markers and mechanisms of Bacterial Cold Water Disease in Rainbow Trout (Oncorynchus mykiss) revealed using mass spectrometry proteomic analysis
Authors: Root Larken
Published: June 2021

Aquaculture is a rapidly expanding agricultural field, especially at the international level. One of the largest issues which arise from raising high densities of fish in a confined area is infection and rapid transmission of disease within the population. There are currently few federally approved pharmaceutical treatments for fish, making rapid and accurate diagnosis essential for maintaining healthy populations. The current study focuses on the infection of rainbow trout (Oncorynchus mykiss) by the gram‐negative bacteria Flavobacterium psychrophilum which manifests as Bacterial Cold Water Disease (BCWD). The approach involves examining the physiological effects of infection in these fish at the protein level. Using LC‐MS techniques, the majority of proteins in the kidney, spleen, plasma, and muscles at site of infection are analyzed for differential abundance between infected and control populations. Artificially infected cohorts are compared against fish taken from an active hatchery to determine whether lab results are reflected in a real‐world context. Sets of proteins which change in abundance as a response to BCWD infection make ideal candidates as bio‐markers which can be used in the development of diagnostic tools. This method also reveals the underlying mechanisms of the infection and response through gene ontology and pathway analysis. Plasma was found to have the greatest regulation in terms of significantly different protein abundance. For this reason and the relative ease of sampling plasma without fish sacrifice, plasma appears to the best tissue for diagnostic purposes. The greatest protein regulation in the plasma was seen in enzymes involved in glycolysis, actin cytoskeletal regulation, immune response, and oxidation‐reduction regulation.

Support or Funding Information

Supported by NSF Grant IOB‐1355098
The Value of Anthropometric Indices for Identifying Women with Features of Metabolic Syndrome
Authors: Welch Lucas C , Horn William , Krishnan Sridevi , Kishimura Kathleen , Que Excel , Holguin Evelyn , Keim Nancy L
Published: June 2021

BMI is a widely used anthropometric measure for identifying CVD and metabolic syndrome (MetS) risk. Two new anthropometric indices are A Body Shape Index (ABSI) and Body Roundness Index (BRI) that may provide better correlations to features of MetS.

Methods

Subject data were obtained from 91 overweight or obese (BMI 31.8 kg/m2 ± 3.7) women who screened for participation in a dietary pattern intervention study (NCT02298725). The screening consisted of collecting anthropometric, blood biomarker, and blood pressure measures. The screening measures were performed to identify participants who have metabolic syndrome.

Results

Ninety one participants were successfully screened for symptoms of metabolic syndrome. Three anthropometric indices, BMI, ABSI, and BRI, were used to find correlations with clinical measures of MetS. Fasting OGTT Glucose (FG), Two Hour OGTT Glucose (Gluc‐2Hr), Hemoglobin A1c (HbA1C), and Quantitative Insulin Sensitivity Check Index (QUICKI) did not significantly correlate with any of these indices. All of these indices had a significant correlation with Triglyceride (TG) and log HOMA (Homeostatic Model Assessment). BRI and BMI had high correlations with several blood measures that are indicative of MetS.

Out of the anthropometric indices studied, BRI was significantly correlated with TG (r=0.362), HDL (r=−0.418) and HOMA (r=0.303). BMI was significantly correlated with HOMA (r=0.400), log HOMA (r=0.405), and the Matsuda Index (r=−0.255). Although demonstrating significant correlations with several measures, ABSI had weaker correlations than both BRI and BMI in all cases.

It is also of note that there is significant difference between the mean ABSI of participants who had one or less, two, or three or more primary parameters of MetS (p=0.0008). Similarly, the mean BRI of participants in these MetS groups were also different (p<0.001).

Conclusion

In general, BRI showed a stronger relationship to dyslipidemic measures while BMI showed a stronger relationship to glucose intolerance. Both ABSI and BRI showed significant differences between participants who had ≤1 feature of MetS and those who had ≥3 features of MetS, suggesting a potential role of ABSI and BRI as anthropometric indices for predicting MetS. With our next 100 screened participants we will be using these indices to validate these relationships.

Support or Funding Information

National Dairy Council and USDA project #2032‐51530‐022.
HIV infection is associated with a lower rate of gestational weight gain and reduced neonatal length
Authors: Natamba Barnabas Kahiira , Vermeylen Francoise , Young Sera L , Griffiths Jeffrey K , Brannon Patsy M , Mehta Saurabh
Published: June 2021

Background

Adequate gestational weight gain (GWG) and neonatal growth are important, respectively, for favorable birth outcomes and survival of infants through the first year. In sub‐Saharan Africa, underlying infections, such as HIV, may adversely impact GWG and neonatal growth. We investigated trends in GWG among HIV‐infected and ‐uninfected women in northern Uganda; and, examined growth parameters of their HIV‐exposed and ‐unexposed neonates.

Methods

403 (133 HIV‐infected and on treatment vs. 270 ‐uninfected) pregnant women were recruited into this study from the antenatal clinic of Gulu Hospital. Women's height and weight were measured at enrollment (mean (±SD) gestational age =19.4 (±−3.8) weeks) and weight was measured at each follow‐up visit. After delivery, a subsample (n=246) of dyads was enrolled into a postnatal cohort. At one month postpartum, length and weight were measured and growth indicators (HAZ, WAZ and WHZ) were evaluated using the 2006 WHO standards. Other important variables were documented at recruitment using a detailed questionnaire. Multivariate regression models were employed to determine whether HIV status was associated with 1) the weekly rate of GWG and 2) neonatal indicators of growth.

Results

Adjusted models indicated a quadratic trend in GWG in both HIV infected and uninfected pregnant women. The rate of GWG among HIV infected women was significantly lower than that of HIV uninfected women (p=0.001). Prenatal HIV exposure was associated with significantly lower HAZ (p=0.013) and a nonsignicant trend towards lower WAZ; but, HIV exposure was not associated with WHZ at one month postpartum. HIV‐exposed neonates were more likely to be stunted (HAZ≤−2) than those who were –unexposed (adjusted odds ratio (aOR) (95%CI): 3.48 (1.29; 9.40).

Conclusion

These results provide strong justifications for studies to understand mechanisms that underlay the negative effects of HIV infection or exposure on gestational weight gain and linear growth of HIV exposed neonates in this context.

Support or Funding Information

This research was funded in part by Cornell University Weill Medical College Intercampus Seed Funds, K01 MH098902 from NIMH and USAID Cooperative Agreement AIDOAAL1000006
Human amylin proteotoxicity impairs protein biosynthesis, and alters major cellular signaling pathways in the heart, brain and liver of humanized diabetic rat model in vivo
Authors: Ilaiwy Amro , Liu Miao , Parry Traci S. , Bain James R. , Muehlbauer Mike J. , Willis Monte S. , Despa Florin
Published: June 2021

The 37 amino acid hormone Amylin is co‐secreted with insulin from β cells in the pancreas. In pre‐diabetic and obese humans, chronic amylin hyper‐secretion parallels the course of disease and is involved in the pathophysiology of beta cell destruction in the pancreas. In rats with transgenic expression of beta cell amylin (HIP), we have discovered that human amylin is prone to misfolding and has proteotoxic effects in vivo, resulting in the induction of cell death paralleling the pathophysiology of neurodegenerative disease. These misfolded proteotoxic amylin proteins are found to migrate to both the brain and heart to induce both neurologic deficits and cardiac dysfunction. In the present study, we use non‐targeted GC‐MS metabolomics analysis to investigate the metabolic consequences of amyloidogenic and cytotoxic amylin oligomers and diabetes in HIP heart, brain, liver, and plasma compared to wild type controls at 1 year of age. We identified that HIP hearts had 45 significantly altered metabolites by t‐test (p<0.05) compared to wildtype control hearts (0.1–34.3 fold different, N=8/group). Similarly, we identified 30 metabolites significantly different in the HIP brain by t‐test (p<0.05) compared to wildtype control brains (0.2–25.2 fold different (N=~10/group). HIP livers had 58 metabolites significantly altered by t‐test (p<0.05) compared to wildtype livers (0.01–99.4 fold different, N=~10/group. Pathway enrichment analysis identified a systemic alteration in protein biosynthesis in the heart and brain of HIP rats compared to wild type controls. Phenylalanine metabolism and aminoacyl‐tRNA biosynthesis were specifically decreased in heart and plasma. Tyrosine metabolism is affected across organs, including decreased tyrosine (heart), phenylalanine (heart, liver, brain), and increased fumarate (heart, liver, brain). Increased urea and urea cycle were identified in heart and liver. As protein degradation is a major up‐regulator of the urea cycle in human rat diabetic models, these findings suggest a broader connection between amylin, diabetes, protein catabolism, and effects on the urea cycle, which may contribute to the increased morbidity and mortality in diabetics at a multi‐system level beyond the effects on glucose metabolism.

Support or Funding Information

This work was supported by the National Institutes of Health (R01HL104129 to M.W.; R01HL118474 to F.D.), a Jefferson‐Pilot Corporation Fellowship (to M.W.), National Science Foundation (CBET 1357600 to F.D.), Alzheimer's Association (VMF‐15‐363458 to F.D.) and the Leducq Foundation (to M.W.).
Heat Stress Effects on the Kinetics of Olfactory Responses
Authors: Hagerty Samantha , Singletary Melissa , Globa Ludmila , Pustovyy Oleg , Morrison Edward E , Sorokulova Iryna , Vodyanoy Vitaly J
Published: June 2021

Temperature is one of the most challenging stressors, affecting human and animal health. Extreme heat stress can damage the olfactory sensory neurons. In this work, we examined the effects of elevated temperature on the kinetic properties of rat olfactory sensory receptors in vitro by the recording of electroolfactogram (EOG) of the olfactory epithelium (OE) removed from the animals before and after the heat stress at 45 ºC for 25 minutes. EOG were evoked by an odorant mixture of ethyl butyrate, eugenol, and (+) and (−) carvone. The biochemical properties of the animal blood related to heat stress were characterized. Exposure of rats to high temperature resulted in a significant increase of body temperature. The mean body temperatures of rats before and immediately after heat stress were 36.7±0.07 ºC and 40.3 ±0.17 ºC, respectively. The kinetic properties of electrical responses to odorant were significantly changed in animals subjected to heat stress. The mean half‐rise (tr)and –decay times (td) of control OE were 328±11 and 660±20 ms, respectively. The rise and decay of EOG peak amplitude after heat stress were much faster, being reduced by 175 %, and 72 %, respectively. Heat stress did not result in a change of IL‐1β; IL‐6, TNF‐α, INF‐γ cytokines level. However, a significant increase of the IL‐10 level was found in rats exposed to heat. The level of lipopolysaccharides (LPS) was significantly increased in the serum of heat‐stressed animals compared to control animals. The concentration of free vesicles in animal blood increased after exposure to heat stress from (1.4±0.2)×106 to (3.8±0.3)×106 vesicles μl−1, indicating a faster conversion of erythrocytes into echinocytes. The kinetic properties found in this work are consistent with the kinetics of cultured mouse olfactory neurons 1. The effect of elevated temperature on the kinetic properties of olfactory receptors is also consistent with those seen in other neurons2–4. Detrimental effects of elevated temperatures on olfaction are shown in other animals5. The change in kinetic properties of olfactory receptors as a result of elevated temperature is consistent with those in other neurons2–4. Cytokines were found to cause neurodegeneration of the olfactory bulb6. We conclude that heat stress causes a strong irreversible modulation of olfactory responses.

Support or Funding Information

Supported by grant from the National Institute of Standards and Technology: 70NANB14H324
High‐Fat Diet Induced Modulation of Glutamatergic Currents in Neurons of the Dorsal Motor Nucleus of the Vagus
Authors: Clyburn Courtney E. , Browning Kirsteen N.
Published: June 2021

A high fat diet (HFD) has been shown to induce reactive gliosis in many areas of the central nervous system, including the brainstem. This gliosis, and particularly astrocyte activation, have been shown to modulate the properties of the synapse including synaptic strength. While we demonstrated previously that longer‐term exposure to a HFD affects synaptic transmission to neurons of the dorsal motor nucleus of the vagus (DMV) in rats, the effects of short‐term exposure have not been examined. The purpose of this study is to test the hypothesis that, following short periods of exposure to a HFD, astrocyte activation contributes to the modulation of synaptic transmission in the DMV.

Whole cell patch clamp recordings of DMV neurons were made from thin (300mm) brainstem slices from Sprague‐Dawley rats 4–6 years of age. Rats were fed a control diet (14% kcal from fat) throughout the study, or a HFD (60% kcal from fat) for 3–7 days prior to experimentation. The effects of fluoroacetate (100μM), an astrocyte metabolism inhibitor, on glutamatergic miniature excitatory postsynaptic currents (mEPSCs) were examined.

The short periods of exposure to HFD employed in the current study did not alter DMV neuronal properties. Since astrocytes are primarily responsible for glutamate uptake and clearance from the synapse, neurons were defined as responding to fluoroacetate if the drug induced a significant increase in mEPSC decay time. Accordingly, 7/13 HFD neurons responded to fluoroacetate, and in these neurons, both the amplitude and frequency of glutamatergic mEPSCs were decreased significantly (11.7 ± 0.85 pA in fluoroacetate vs 15.2 ± 0.85 pA in control; 0.5±0.09 vs 1.1±0.25 events per second; n=7; p<0.05 for both). In contrast, in control rats, neither the amplitude nor frequency of mEPSCs were affected by fluoroacetate, even in the 3/12 responding neurons (16.5 ± 0.55 pA vs 15.0 ± 0.1 pA; 0.8±0.25 vs 1.0±0.34 events per second; n=6; p>0.05 for both).

This study suggests that even short periods of exposure to a HFD alter astrocyte activity that subsequently modulates synaptic transmission. Fluoroacetate‐induced alterations in both frequency and amplitude of glutamatergic synaptic events suggests that this modulation occurs both presynaptically and postsynaptically. Astrocytes are known to release glycine and D‐serine, which are essential co‐factors for the NMDA receptor. While the NMDA receptor appears not to be tonically active in the DMV under normal conditions, altered astrocyte function may contribute to the increase in glutamatergic mEPSC amplitude in HFD. In total, these results indicate that short‐term exposure to a high fat diet may alter the synaptic strength in the DMV, even in the absence of HFD‐induced weight gain or peripheral inflammation. These modulations of vagal circuitry may dysregulate gastrointestinal reflexes or disrupt gastric motility.

Support or Funding Information

Funded by NIH 078364 and NSF IOS1148978
Poloxamer 188 Improves Autoresuscitation in Pigs with Severe Traumatic Hemorrhage
Authors: Martini Wenjun , Xia Hui , Dubick Michael A
Published: June 2021

Introduction

Poloxamer 188 (P188) is a copolymer surfactant. Its protective effects against ischemic injury, cardiomyopathy, and intracerebral hemorrhage have been shown in studies from rats and mice. The underlying protective mechanisms are unclear. This study investigated its effects on blood volume in pigs after severe traumatic hemorrhage and hypotensive resuscitation.

Methods

Twenty anesthetized and instrumented pigs were randomized into saline (n=10) and P188 (n=10) groups. Femur fracture was performed in each pig's left leg, followed by hemorrhage of 55% of estimated blood volume and 15 min shock period. Afterwards, pigs were resuscitated with small volume of saline (4ml/kg) or P188 (1.33 ml/kg of P188 200mg/ml, plus 2.67 ml/kg saline). Indocyanine green dye (5ml of 1mg/ml) was injected before femur and hemorrhage and 15 min after P188 administration with blood samples taken accordingly to determine changes of blood volume and Hct. Pigs were monitored for 6h or until death.

Results

All baseline measurements are similar between the two groups. Femur and hemorrhage reduced mean arterial pressure to 54±6% of baseline values and reduced blood volume from 104±4 ml/kg to 67±4 ml/kg (both p<0.05) and reduced Hct from 31±1% to28±1% in the saline resuscitated group. Less reduction was observed with P188 resuscitation in blood volume (from 98±3 ml/kg to 74±3 ml/kg, p<0.05 compared to baseline and to saline values), with a consistent larger drop in Hct (31±1% to 24±1%, p<0.05 compared to baseline and to saline values). Survival time was similar between the saline (225±45 min) and P188 (235±78 min) groups.

Conclusions

Following severe traumatic hemorrhage and small volume resuscitation in pigs, P188 improved autoresuscitation, but did not affect short term survival.

Support or Funding Information

US Army Medical Research and Materiel Command
Effects of Systemic Hypercapnia and Orexin on Gastric Motility and Respiration in Rats
Authors: Sherwood Jacob William , Landon Carol , Dean Jay
Published: June 2021

The theory of pneumogastric ventilation predicts that systemic hypercapnia causes a primary pulmonary hypercapnic ventilatory response (HCVR) that is supplemented by a secondary gastric ventilatory response that work together to remove excess CO2 from the body. Gastric ventilation consumes arterialized CO2 during increased production and secretion of gastric acid. In the stomach lumen, CO2 is reconstituted and “ventilated” out through the esophagus, mixed in the oropharynx with pulmonary gas and “exhaled”. Activation of gastric ventilation occurs during CO2 retention in a hypercapnic environment or with alveolar hypoventilation such as COPD. Both pulmonary and gastric ventilatory responses are integrated and coordinated at the level of the caudal solitary complex (cSC), mediated in large part by the vagus nerve (Dean, 2011, Resp Physiol Neurobiol 175(2): 189–209). Central chemoreceptors in the cSC or stimulated by both CO2/H+ and orexin. Likewise, CO2/H+ and orexin stimulate pulmonary ventilation and gastric acid secretion. In fact, hypercapnia causes an increase in production of orexin, which helps maintain the HCVR during wakefulness (Nattie et al, 2010, J Appl Physiol 89: 153–162). Consistent with the theory of pneumogastric ventilation, we found that hypercapnia causes an acute decrease in gastric pH. We do not know, however, how hypercapnia affects gastric motility. Accordingly, we implanted male Sprague‐Dawley rats with the DSI 4‐ET Telemetry unit to measure ECG, respiratory rate via diaphragmatic EMG (dEMG), and gastric EMG (gEMG) to measure gastric motility. Following recovery from surgery, we then subjected them to step‐wise increases in ambient CO2 (30 min/step) starting with air, 5% CO2 in air, 10% CO2 in air, and recovery in air. We also tested the effects of orexin on gastric motility during normocapnia using a lateral tail vein IV injection of orexin‐A. Histamine was used as a positive control for gastric motility. Our findings show that in air, gEMG activity occurs roughly every 15 seconds with bursts lasting 3–4 seconds. Graded hypercapnia caused a graded decrease in the amplitude of periodic gEMG bursts (5% CO2) that stopped completely in 10% CO2. Recovery in air rapidly returns gEMG activity to normal. As expected, dEMG increased with increasing CO2. Similarly, orexin‐A causes an immediate decrease in gEMG activity. We postulate that CO2 activates cSC neurons causing vagally‐mediated relaxation of gastric smooth muscle and increase in gastric acid production to ventilate gastric CO2 during systemic hypercapnia.

Support or Funding Information

ONR N000141310405 & N000141612537
Episode Frequency Determines the Impact of Chronic Intermittent Hypoxia on Phrenic Long Term Facilitation
Authors: Gonzalez‐Rothi Elisa Janine , Perim Raphael Rodrigues , Tadjalli Arash , Simon Alec K , Ciesla Marissa , Mitchell Gordon S
Published: June 2021

Acute intermittent hypoxia (AIH) elicits a form of spinal, phrenic motor plasticity known as phrenic long‐term facilitation (pLTF). Preconditioning with chronic intermittent hypoxia (CIH) as might be experienced during sleep disordered breathing, has conflicting effects on pLTF. For example, preconditioning with CIH consisting of 5 min hypoxic episodes with 5 min intervals (12 hours per night; 7 days) enhances AIH induced pLTF (Ling et al., 2001). Conversely, 8 hours of intermittent hypoxia consisting of 2 min episodes with 2 min intervals 16 hours prior to AIH abolishes pLTF through a mechanism that requires systemic inflammation and spinal p38 MAP kinase activation (Huxtable et al., 2015). We hypothesized that this differential response resulted from differences in the frequency hypoxic episodes (6 versus 15 per hour), versus the cumulative duration (1 versus 7 days) or timing (day versus night) of intermittent hypoxia. Thus, we compared the impact of intermittent hypoxia presented for 7 consecutive days, 8 hours per day (IH‐7). The three experimental groups were: 1) 5 min episodes of 10.5% O2 with 5 min normoxic intervals (6 episodes/hour, 8 hours/day, 7 days; IH‐7‐5min); 2) 2 min hypoxic episodes (10.5% O2) with 2 minute normoxic intervals (15 episodes/hour, 8 hours/day, 7 days; IH‐7‐2 min); and 3) naïve rats exposed to normoxia (21% O2; 8hrs/day, 7 days; sham). Neurophysiology experiments conducted 16 hours after the final day of IH‐7 enabled assessment of AIH‐induced phrenic and hypoglossal long‐term facilitation. In comparison with sham rats, rats preconditioned with IH‐7‐5 exhibited normal pLTF expression (45% baseline; p < 0.05). In rats preconditioned with IH‐7‐2, pLTF was abolished (7% baseline; p> 0.05). Mean arterial pressure was elevated in rats exposed to IH‐7‐2 (10mmHg), but not IH‐7‐5. Thus, the impact of CIH on pLTF and arterial blood pressure is highly dependent on the frequency of hypoxic episodes. An important transition in impact of CIH from pro‐plasticity to pro‐inflammatory/pathogenic (Dale et al., 2014) occurs between 6 and 15 episodes per hour, consistent with previous literature reports (Navarette‐Opazo et al., 2014).

Support or Funding Information

Supported by: K12HD055929 (EGR), 1R01HL69084 (GSM); 1R01HL511198 (GSM)
Intraspinal microstimulation induced respiratory phase resetting
Authors: Sunshine Michael Daniel , Ganji Comron Nassar , Reier Paul J , Moritz Chet Thomas , Fuller David D
Published: June 2021

Electrical stimulation of the spinal cord can activate somatic motor circuits after spinal cord injury. In particular, stimulation of the dorsal spinal cord has translated into clinical use due to the relatively low invasiveness. Modeling studies indicate that dorsal activation of motor pathways occurs through excitation of afferent projections to spinal motor pools. However, because spinal stimulation does not always allow for activation of discrete neuronal populations, off target effects are often observed. In ongoing studies, our group is investigating intraspinal microstimulation as a tool to activate respiratory motoneurons with possible application to spinal cord injury. Currently it is unclear if and how intraspinal stimulation will alter the pattern of respiratory output produced by the brainstem. However, activation of ascending respiratory‐related afferent fibers in cervical dorsal white matter or spinobulbar projections from cervical interneurons has the potential to modulate the respiratory pattern. Here we tested the hypothesis that intraspinal microstimulation in the dorsal but not ventral mid‐cervical spinal cord would rapidly alter the timing of inspiratory discharge. Diaphragm, external intercostal, and sternocleidomastoid electromyography activity was recorded in N=6 anesthetized and ventilated spinal intact adult rats. Following unilateral laminectomy from C2‐T1 a 10×2 grid was established by dividing the rostrocaudal exposed cord into ten sites with the two stimulus tracts located 0.5 and 1mm lateral to midline. A tungsten electrode was gradually advanced from the dorsal spinal surface to depth of 1800–2400μm with 10–90 μA currents (0.3 ms per phase, biphasic pulses) delivered every 600 μm. Dorsal stimulation (average simulation depth of 478 μm) resulted in an abrupt increase in respiratory rate (breaths per minute) at~13% of tested sites. Of the sites that triggered increases in respiratory rate, 54% were located at the dorsal surface (i.e., depths of 0 μm). These initial results indicate that intraspinal stimulation of the dorsal cervical spinal cord can trigger rapid changes in respiratory rate, presumably via activation of ascending pathways which innervate brainstem respiratory neurons.

Support or Funding Information

FUNDING: 1R01NS080180‐01A1 (DDF), NICHD: T32‐HD043730 (MDS), Department of Defense W81XWH‐14‐1‐0625 (PJR)
High‐altitude Adaptation and Hypoxia Signaling in Deer Mice
Authors: Scott Graham R. , Ivy Catherine M. , Tate Kevin B. , Velotta Jonathan P. , Schweizer Rena M. , Cheviron Zachary A.
Published: June 2021

The hypoxic and cold environment at high altitudes requires that endothermic animals sustain high rates of O2 consumption for both locomotion and thermogenesis while facing a diminished O2 supply. Recent evidence suggests that genes in the hypoxia inducible factor (HIF) pathway have been targeted by natural selection and have contributed to evolutionary adaptation to high altitudes in several species. Here, we examine the role of hypoxia signaling in high‐altitude adaptation in deer mice (Peromyscus maniculatus). Maximal O2 consumption (VO2max) in hypoxia is augmented in high‐altitude populations, underpinned by increases in pulmonary O2 extraction, arterial O2 saturation, cardiac output, and tissue O2 extraction compared to low‐altitude populations. Highlanders also maintain higher heart rates during deep hypoxia at rest. Associated with the population differences in physiology is extreme allele frequency variation in a non‐synonymous single nucleotide polymorphism in Epas1, the gene encoding HIF‐2α. Transcriptome scans indicate that these differences in Epas1 allele frequency stem from a history of spatially varying selection between high and low altitudes. RNA‐Seq measurements of gene expression in the left ventricle show that transcriptomic variation in HIF target genes is correlated to VO2max. Furthermore, comparisons of the hypoxia response between mice with different Epas1 genotypes (captured from an admixed population on the summit Mount Evans CO) show that the high‐altitude Epas1 allele is associated with higher heart rates in deep hypoxia, but that it has no association with variation in breathing or blood haemoglobin content. Our results therefore suggest that changes in hypoxia signaling contribute to high‐altitude adaptation in deer mice.

Support or Funding Information

Supported by NSERC of Canada and the USA National Science Foundation
Mitochondria‐derived Small Non‐coding RNAs in Extreme Anoxia Tolerance
Authors: Riggs Claire Louise , Podrabsky Jason Earl
Published: June 2021

Mitochondria are critical sensors of oxygen and play a major role in the regulation of the cellular response to oxygen deprivation. Understanding mitochondrial function during transitions into and out of anoxia in species that can tolerate anoxia may lend new insights into the role that mitochondria play in cellular homeostasis in response to fluctuating levels of oxygen. The objective of this study was to examine the potential role of small RNAs in long‐term vertebrate anoxia tolerance. Expression patterns of small RNAs were determined using RNAseq in the most anoxia tolerant vertebrate, embryos of the annual killifish Austrofundulus limnaeus. Anoxia tolerance varies during development in this species in a way that allows for the comparison of developmental stages with extreme anoxia tolerance to stages with a more typical vertebrate anoxia tolerance. Embryos of 4 different developmental stages were exposed to anoxia, followed by aerobic recovery, and small RNA expression was determined with Illumina RNAseq under aerobic conditions, anoxia, and during aerobic recovery. A large proportion of the differentially expressed small RNAs were found to be encoded in the mitochondrial genome. About 12% of the unique small RNAs identified were encoded within the mitochondrial genome, and around 20% of the highly differentially expressed RNAs in response to anoxia were mitochondrial in origin. Of the differentially expressed sequences mapping to the mitochondrial genome, small RNAs derived from mitochondrial tRNAs were particularly enriched, with sequences up‐regulated during anoxia and aerobic recovery from anoxia. These small RNAs of interest localize to anoxia sensitive tissues, such as the brain and heart, providing further evidence for a potential role in supporting anoxia tolerance. These same small RNAs have been detected in cell cultures derived from A. limnaeus embryos, by RNAseq and in situ hybridization. Cell culture expression patterns corroborated whole‐embryo sequence expression patterns. This work highlights a potential new class of small RNAs derived from the mitochondrial genome that may act to mediate and coordinate the physiological response to anoxia in this species. Further understanding the biology of these mitochondrially‐derived small RNAs and their role in anoxia tolerance may provide novel insight into combating cellular damage induced by heart attack and stroke, two lethal consequences of heart disease in humans.

Support or Funding Information

NSF IOS 1354549; NSF GRFP DGE 1057604
Dietary Depletion of Bovine Milk Exosomes Elicits Changes in Amino Acid Metabolism in C57BL/6 Mice
Authors: Leiferman Amy L. , Aguilar Ana , Mutai Ezra , Adamec Jiri , Zempleni Janos
Published: June 2021

Background

Exosomes are small, cargo‐containing vesicles that are secreted by donor cells to elicit changes in gene expression and metabolism in recipient cells. We have discovered that dietary exosomes from bovine milk can be absorbed by non‐bovine species; studies in murine C2C12 myotube cell cultures suggest that bovine exosomes promote the growth of myofibers.

Hypothesis

The dietary intake of bovine milk exosomes alters amino acid metabolism, and possibly muscle protein accretion, in non‐bovine species.

Significance

The dietary intake of exosomes might promote muscle protein accretion in patients with sarcopenia and low‐birth‐weight babies.

Methods

C57BL/6 mice, age 3 weeks, were fed an exosome‐depleted (Exo−) AIN93G‐based diet for four weeks; controls were fed an exosome‐sufficient (Exo+) diet. Livers were harvested. The hepatic metabolome was assessed by non‐targeted LC/MS‐MS and by peak intensity analysis; the hepatic transcriptome was assessed by RNAseq using an Illumina HiSeq2500 platform. A second cohort of mice was fed Exo− or Exo+ diets for 4–6 weeks for subsequent analysis of grip strength, respiratory exchange ratio (RER), feeding and activity patterns; skeletal muscle samples are currently analyzed by RNAseq. Statistical significance was assessed using unpaired, two‐tailed t‐test.

Results

Hepatic concentrations of several amino acids were significantly higher (up to 18 times) in mice fed the Exo− diet than in Exo+ controls (Fig. 1). The mRNA expression of branched chain amino acid (BCAA) transporters 1 (cytoplasm) and 2 (mitochondria) was greater in mice fed Exo− compared to Exo+ (n.s. for BCAT2; Fig. 2). The RER was not affected by feeding, whereas grip strength was a moderate 5% higher in Exo+ vs. Exo− females after only 4 weeks of feeding (n.s.; not shown). The trend toward a greater grip strength was not caused by differences in food and water consumption or physical activity, which were not significantly different between treatment groups in females.

Conclusion & future plans

Diets defined by their bovine milk exosome content alter amino acid metabolism in mice. Future studies will investigate protein metabolism by using stable isotopes, and assess muscle protein accretion in response to stimuli such as muscle wasting.

Support or Funding Information

NIFA 2015‐67017‐23181, NIFA 2016‐67001‐25301/NIH DK107264, NIH 1P20GM104320, the Gerber Foundation, and USDA Hatch Act and W3002.
Curcumin and piperine inhibit mTORC1 signaling in intestinal epithelial cells
Authors: Moreau Regis , Kaur Harleen
Published: June 2021

Persistent mTORC1 activation is not only linked to metabolic disorders but also cancer and inflammation by inducing transcription and translation of pro‐inflammatory cytokines. Gastrointestinal cancers are frequently associated with chronic inflammation and excessive secretion of IL‐6 family cytokines, which promote tumorigenesis through persistent activation of PI3K/mTORC1 pathway. Curcumin is the major natural phenol in turmeric, Curcuma longa. Curcumin inhibits a number of different molecules that play a role in inflammation such as TNFα, cyclooxygenase‐2, inducible nitric oxide synthase. Curcumin like many other dietary phenolic compounds has poor bioavailability in part due to extensive metabolism in the intestinal mucosa. Piperine, one of the major components of black pepper, has been shown to increase the bioavailability of dietary phenolics including curcumin. The long‐term objective of the study is to determine whether curcumin and piperine have individual and combined effects in the prevention of gut inflammation via inhibition of mTORC1 in Caco‐2 and HT‐29 cells. Results show that curcumin inhibited mTORC1 activity (phosphorylation state of its downstream targets, ribosomal protein S6 kinase β‐1 and ribosomal protein S6) in a dose dependent manner (ribosomal protein S6 phosphorylation: −52% at 2.5 μM, −84% at 20 μM, P<0.05). Piperine inhibited mTORC1 activity in its own right (ribosomal protein S6 kinase β‐1 phosphorylation: −84% at 2.5 μM, −91% at 20 μM, P<0.05). The combination of curcumin + piperine further inhibited the mTORC1 signaling. mTORC1 activity was markedly elevated (+2600%) in undifferentiated vs. differentiated Caco‐2 cells. Since epithelium dedifferentiation precedes the release of pro‐inflammatory cytokines and the neoplastic process, we are investigating the link between mTORC1 and the pro‐inflammatory cascade in these cells, and how curcumin +/− piperine mitigate these events. We conclude that widely available dietary phenolics, curcumin and piperine, have the potential to regulate the mTOR pathway in the intestine. While curcumin and piperine inhibit mTORC1 signaling independently of each other by mechanisms yet to be characterized, piperine may also indirectly potentiate curcumin activity through enhancement of its bioavailability.

Support or Funding Information

Supported by USDA‐NIFA.