bluuebunny/crossref_metadata_2025 huggingface dataset:
Targetting CB1 Cannabinoid Receptor for Neuroprotetion in Spinal Cord Injury
Authors: Mukhopadhyay Somnath , Sheng Huaxin
Published: June 2021

Endogenous cannabinoids expression has been shown to increase following traumatic brain injury (TBI) and spinal cord injuries (SCI). Post‐TBI treatment with endocannabinoid has been reported to produce lesser disruption of blood brain barrier, and resulted in better clinical recovery in a mouse TBI model. However, to date no report is available regarding the use of synthetic CB1 cannabinoid receptor (CB1R) agonist in enhancing post‐SCI functional recovery. In the current study we tested the efficacy of CB1R agonists for neuroprotection following SCI in mice. We hypothesized that post‐SCI pharmacologic activation of CB1R will produce neuroprotective effects for axonal damage and will result in a better recovery. Our results show that post‐SCI treatment with CB1R agonists in mice decreased matrix metalloprotease 9 (MMP‐9) activity following spinal cord injury, and ameliorate the disruption of blood spinal cord barrier (BSCB). We have also shown that post‐SCI treatment with CB1R agonists improve both functional and histological outcome. Together these results raise the possibility that CB1R can be used as therapeutic target for spinal cord injury.
Differential effects of adenosine A2A and A2B receptors on basal coronary regulation and ischemia‐induced hyperemia
Authors: Tan Xinglin , Cai Chun , Tilley Stephen L , Ledent Catherine , Krahn Thomas , Hofmann Polly A , Morrison R Ray
Published: June 2021

We determined the relative contribution of A2A and A2B adenosine receptors (AR) in basal coronary flow (CF), ischemia‐induced coronary hyperemia (CH), and ischemic postconditioning (POC)‐induced coronary protection. Isolated hearts from A2AAR knockout (A2AKO) and A2BKO and their corresponding wild‐type (WT) mice underwent 20 min global ischemia and/or POC with or without pharmacologic analogues of adenosine. Basal CF in A2AKO but not A2BKO hearts was lower than that of WT hearts. Inhibition of A2AAR with 50 nM ZM241385 attenuated basal CF in WT hearts, but inhibition of both A2AAR and A2BAR with 500 nM ZM241385 did not further reduce basal CF. Ischemia‐induced CH in A2BKO but not A2AKO hearts was lower than that of WT hearts. In WT hearts, CH was reduced by 500 nM but not 50 nM ZM241385. The selective A2BAR agonist BAY60‐6583 increased CH in A2AKO hearts, but the selective A2AAR agonist CGS21680 failed to increase CH in A2BKO hearts. For all groups, CH induced by 20 min global ischemia was lower than that induced by POC alone, or by 20 min global ischemia followed by POC. Collectively, our data indicate A2AAR but not A2BAR is involved in regulating basal CF, while A2BAR but not A2AAR is important in ischemia‐induced CH and POC‐mediated coronary protection. (Supported by HL74001 to RRM)
IL‐10 promotes cardiomyocyte survival through the activation of Akt and transcription factor Stat3
Authors: Dhingra Sanjiv , Bagchi Ashim K , Al‐Shudiefat Abd Al‐Rahman , Sharma Anita K , Singal Pawan K
Published: June 2021

We have already reported that IL‐10 prevents TNF‐α induced increase in oxidative stress and apoptosis in cardiomyocytes. Present study investigated the role of Akt and Jak/Stat pathway in IL‐10 mediated survival of cardiomyocytes. Isolated cardiomyocytes from adult Sprague Dawley rats were exposed to TNF‐α (10ng/ml), IL‐10 (10ng/ml) and TNF‐α+IL‐10 (ratio 1) for 4h. Exposure to TNF‐α resulted in decrease in cell viability and an increase in cardiomyocyte apoptosis. IL‐10 by itself had no effect, but it prevented TNF‐α induced cardiomyocyte apoptosis and enhanced the cell survival. Furthermore, IL‐10 treatment increased Akt levels within cardiomyocytes and this change was associated with an increase in Jak1 and Stat3 phosphorylation. Pre‐exposure of cells to Akt/or Stat3 inhibitor prevented IL‐10 modulation of TNF‐α induced cardiomyocyte apoptosis. Furthermore, in the presence of Akt inhibitor IL‐10 treatment was unable to induce Stat3 phosphorylation. It is concluded that Akt regulates IL‐10 mediated survival of cardiomyocytes by upregulating Stat3 phosphorylation (Supported by CIHR‐IMPACT, Canada).
Novel role of nicotinic acetylcholine receptor‐dependent signaling in macrophage survival
Authors: Tano Jean‐Yves K , Vazquez Guillermo
Published: June 2021

Atherosclerosis is a maladaptive inflammatory response of the arterial wall in which an imbalance between survival and apoptosis of lesional macrophages plays a dominant role. Reduced macrophage apoptosis in the early atherogenic stages increases lesion cellularity and volume and promotes lesion progression. Recent studies depict nicotinic acetylcholine receptors (nAchRs) as epicenters of an anti‐inflammatory response that targets lesional macrophages, but the signaling mechanisms associated with this process remain poorly understood. To gather preliminary insight into a potential link between macrophage nAchRs and signaling mechanisms involved in macrophage survival/apoptosis, we undertook a biochemical/pharmacological approach to study activation status of survival molecules in PMA‐differentiated THP‐1 macrophages (TDMs). Our studies show that treatment of TDMs with cholinergic agonists results in phosphorylation of AKT and IkBα, two critical pathways in regulation of macrophage survival. This effect is recapitulated by agonists that specifically activate nAchRs suggesting that pro‐survival signaling occurs downstream those receptors. Evaluation of macrophage apoptosis (by TUNEL and Annexin V binding assays) will determine if nAchR‐dependent survival signaling translates into reduced macrophage apoptosis. Supported by UT COM & AHA (SDG0635250N to GV)
Curcumin improves large elastic artery stiffness and reverses superoxide suppression of nitric oxide‐mediated vascular endothelial function in old mice
Authors: Howell Kate L , Fleenor Bradley S. , Zigler Melanie L. , Yoshizawa Mutsuko , Marziaz Mandy L. , Seals Douglas R. , Sindler Amy L.
Published: June 2021

We tested the hypothesis that curcumin, a polyphenol found in the Indian spice turmeric, improves age‐associated large elastic artery stiffness and vascular endothelial dysfunction. Old control C57 male mice (27 mo, n=8) had greater aortic pulse wave velocity (aPWV) vs. young control (6 mo n=7) (448 ± 15 vs. 349 ± 15 cm/s, p < 0.05) and 4 wk of curcumin supplemented chow (0.2%) reduced aPWV in old mice (396 ± 15 cm/s, n=8). Old control mice had impaired ex‐vivo carotid artery endothelium‐dependent dilation (EDD) to acetylcholine (ACh) vs. young (79 ± 3 vs. 93 ± 2%), mediated by a smaller nitric oxide (NO) component (EDD to ACh + LNAME minus EDD to ACh alone, 39 ± 11 vs 74 ± 6%) (both p < 0.05). Curcumin restored EDD in old mice (92 ± 1%) by restoring its NO component (61 ± 7%). Incubation with the superoxide dismutase mimetic, TEMPOL, selectively improved EDD in old control mice (91 ± 3%, p < 0.05), but had no effect in the other groups. Endothelium‐independent dilation did not differ between groups. Superoxide production (electron paramagnetic resonance spectroscopy) from aortic rings of old mice was greater vs. young control (7748 ± 897 vs. 4820 ± 492, p < 0.05), and was markedly reduced with curcumin supplementation (2486 ± 533, p < 0.05). Curcumin may be a novel therapeutic nutraceutical agent to destiffen large elastic arteries, restore NO‐mediated vascular endothelial function and reduce arterial superoxide production with aging.
A novel mechanism of Coenzyme Q10 protects against human endothelial cells from oxidative stress‐induced by modulating NO‐related pathways
Authors: Tsai Kun‐Ling , Chiou Shih‐Hwa
Published: June 2021

Background

Atherosclerosis is a chronic inflammatory disease of the vessel wall associated with oxidized low‐density lipoprotein (oxLDL)‐induced apoptosis of endothelial cells. Coenzyme Q10 (Co Q10), a potent antioxidant and a critical intermediate of the electron transport chain, has been reported to inhibit LDL oxidation and thus the progression of atherosclerosis. However, its molecular mechanisms on endothelial cells remain still unclarified.

Methods

In this study, primary human umbilical vein endothelial cell cultures (HUVECs) treated with oxLDL were used to explore the protective effects of Co Q10.

Results

Our results showed that Co Q10 attenuated the oxLDL‐induced generation of ROS and improved the antioxidant capacity. Co Q10 also attenuated the oxLDL‐mediated down‐regulation of endothelial nitric oxide synthase (eNOS) and up‐regulation of inducible nitric oxide synthase (iNOS). In addition, Co Q10 suppressed oxLDL‐activated NF‐κB and downstream inflammatory mediators, including expression of adhesion molecules, release of pro‐inflammatory cytokines, and the adherence of monocytic THP‐1 cells. Moreover, Co Q10 attenuated oxLDL‐altered pro‐apoptotic responses. The inhibitor of eNOS and iNOS as well as NO enhancer were used to clean up the mechanism involved in the protective effects.

Conclusion

These results provide new insight into the possible molecular mechanisms by which Co Q10 protects against atherogenesis by NO‐related pathways.
Effects of phosphorylation at Tyr‐659 in endothelial nitric oxide synthase on its interaction with calmodulin and catalytic activity
Authors: Tran Quang‐Kim , Persechini Anthony , Giles Jennifer
Published: June 2021

eNOS phosphorylation at Tyr‐657 (659 in the bovine sequence) was recently shown to inhibit NO production in cells. Here we show the in vitro effects of Tyr‐659 phosphorylation on eNOS activity and interaction with calmodulin (CaM). Phosphomimetic substitution (Asp) at Tyr‐659 abolishes eNOS cytochrome C reductase activity and NADPH oxidase activity. Adding single or combined Asp substitutions at Ser‐617, Ser‐635, and Ser‐1179 does not change this effect. Single Asp mutation at Tyr‐659 substantially increases the Ca2+ sensitivity for eNOS‐CaM binding, lowering the EC50(Ca2+) for this interaction from 180 ± 2 nM to 45 ± 1.4 nM (p<0.001). Adding Asp substitutions at Ser‐617, Ser‐635, and Ser‐1179 attenuates this effects, increasing EC50(Ca2+) values to ~ 80 nM (p<0.001). Treatment of either wild‐type or S617/1179DeNOS with purified proline‐rich tyrosine kinase (PYK‐2) abolishes eNOS activity, which is restored by ~ 70% by treatment of PYK2‐pretreated eNOS with tyrosine phosphatase. The data suggest that phosphorylation at Tyr‐659 abolishes eNOS activity yet turns the synthase into a very sensitive CaM‐binding protein that can bind CaM at very low basal Ca2+ concentration in cells.
Relationship Between Exercise Capacity And Heart Rate Variability In Trained And Untrained Individuals
Authors: Khanna Deepesh , Kreider Richard B , Tonkin P , Cowan P , Rasmussen Chris
Published: June 2021

PURPOSE

To examine the relationship between exercise capacity and measures of heart rate variability (HRV) in trained and untrained males and to determine whether different types of training affect (HRV) in a different manner.

METHODS

Thirty‐nine male athletes and non‐athletes (21.2±3 yr.) performed a graded maximal exercise test using the Bruce treadmill protocol. Ambulatory Holter monitor was used to record (HRV). The relationship between time to exhaustion and measures of (HRV) were determined using correlation analysis. Additionally, (HRV) for endurance trained, anaerobic‐trained, or non‐trained subjects were compared using one‐way analysis of variance.

RESULTS

Significant correlations were observed between time to exhaustion and the mean of the R‐R intervals (r = 0.51, p = 0.001) and standard deviations of R‐R intervals during 24‐h (r = −0.38, p = 0.017). Additionally, exercise capacity tended to correlate with the square root of the mean for the sum of squares of differences between adjacent R‐R intervals (52.9±24, r = 0.31, p =0.053) and in the proportion adjacent R‐R intervals having differences of 750 milliseconds (22.7±14, r =0.29, p = 0.07). No significant differences were observed between types of training or measures of HRV.

CONCLUSION

Exercise training positively affects selected measures of (HRV) and may help decrease risk of arrhythmia or sudden death.
DHA supplementation and blood lipoproteins in football athletes during heavy physical training
Authors: Crouse Stephen F , Oliver Jonathan M , Martin Steven E , Riechman Steven E , Dobson Justin , McCammon Katie , Weir David , Tanguay Jonathan , Bramhall J P
Published: June 2021

We tested the effects of supplementing 2 g/d of docosahexaenoic acid (DHA) (n=24) or placebo (n=28) on blood lipid profiles (ultracentrifugation) in collegiate football athletes (age=20±2 y, ht=73.9±2.6 in, wt=231±41 lb) during preseason training. Blood obtained after an overnight fast three different times: 1) Summer baseline (BASE) before starting supplements; 2) August, pre‐camp (PREC) after 35 d supplementation; and 3) August, post‐camp (POST) after 52 d supplementation. Nutrition assessments completed each time of blood sampling.

VAR
Placebo (n=28)
DHA (n=24)

BASE
PREC
POST
BASE
PREC
POST

TC
142 ± 6
156* ± 7
148 ± 7
153 ± 6
161* ± 7
156 ± 7

LDL
78 ± 4
85* ± 5
85* ± 5
90 ± 5
95* ± 5
98* ± 5

HDL
51 ± 2
55* ± 3
48** ± 2
50 ± 3
53* ± 3
45** ± 2

TG
110 ± 11
146 ± 19
96* ± 69
115 ± 13
112 ± 21
84* ± 10

VLDL
12 ± 1
16 ± 2
14 ± 2
12 ± 1
13 ± 2
13 ± 2

Table results (adjusted means±SE mg/dL, TC=cholesterol, TG=triglycerides) of 2(supplement)‐by‐3(time) ANCOVA (wt change & race covariates, interactions insignificant) & LSD follow‐ups across time;

= different from BASE,

=different from BASE & PREC, p<0.05).

Reduced HDL‐C and triglycerides with increased LDL‐C during camp might indicate increased cholesterol metabolism for structural repair of damaged tissue. DHA supplementation did not affect the changes in blood lipid profiles of these athletes engaged in heavy physical training.

Funding provided by Martek Biosciences Corp., Columbia, MD
The Effects of Habitual Caffeine Intake on Lean Body Mass and Strength Performance During 12‐Weeks of Resistance Exercise Training
Authors: Bui Steve , Lee Chang Woock , Lee Teak V. , Chen Vincent C.W. , Riechman Steven E.
Published: June 2021

Caffeine ingestion has been shown to potentially improve training and performance in endurance exercise. The effects of caffeine on resistance exercise training (RET) have not been thoroughly explored; however, it has been hypothesized that caffeine can limit muscle growth and recovery post‐RET. Determining whether habitual caffeine use would limit benefits (increased lean mass and strength) associated with RET would be important to those who are currently training. 58 healthy, untrained individuals (Men: 24; Women: 34; Age: 64±3y) underwent 12 weeks of whole‐body RET (8 exercises, 3d·wk−1, 3 sets 8–12 reps, 75% of one‐repetition maximum (1RM)). Three caffeine groups were created based on habitual consumption: low (L) (<150mg/kg/day), medium (M) (151–300mg/kg/day), and high (H) (>300mg/kg/day). Body composition (DEXA) and 1RM were measured before and after training. No difference in percent change in weight lifted (Leg Press: L, (67.03±54.97; M, 57.04±44.09; H, 51.57±55.17; Chest Press: L, 44.14±55.97; M, 32.96±14.64; H, 25.89±23.70; p>0.05), and percent change in lean mass were found between the groups (L, 2.27±3.55; M, 1.55±3.21; H, 2.39±2.59; p>0.05). Our data suggests that there were no negative effects from a wide range of habitual caffeine intakes on muscle response to RET. These results do not predict the effects of a single dose of caffeine on RET responses in an individual unaccustomed to caffeine.
A tyrosyl‐tRNA synthetase variant that is responsible for Dominant Intermediate Charcot‐Marie‐Tooth disorder Type C displays decreased fidelity
Authors: First Eric Allen , Froelich Clifford A. , Richardson Charles J.
Published: June 2021

Charcot‐Marie‐Tooth disorder (CMT) is the most common inherited peripheral neuropathy, affecting 1 in 2,500 people in the U.S. Mutations in over 30 different genes have been found to give rise to CMT, including the genes encoding the glycyl‐, alanyl‐, and tyrosyl‐tRNA synthetases. There is currently no cure for CMT.

Three mutations in the gene encoding the human cytoplasmic tyrosyl‐tRNA synthetase, G41R, Δ(153–156), and E196K, have been found to give rise to Dominant Intermediate Charcot‐Marie‐Tooth disorder, Type C (DI‐CMTC). Based on modeling studies, we postulated that the E196K substitution affects the fidelity of tyrosyl‐tRNA synthestase. To test this hypothesis, the ability of the E196K variant to catalyze the misacylation of noncognate tRNAs was investigated. We find that the E196K variant is ~100‐fold more efficient at aminoacylating tRNATyr variants containing a noncognate G1:C72 base pair than is the wild type enzyme. Replacing Glu 196 with alanine also decreases the fidelity of the enzyme, indicating that Glu 196 acts as an anti‐determinant to prevent the misacylation of tRNAs containing a G1:C72 base pair. This observation suggests that DI‐CMTC is due to misincorporation of tyrosine into proteins, leading to defects in either their stability or ability to fold correctly. This research is supported by MDA 4268 to EAF.
Development of RNA pol‐driven adenovirus vector expressing hepatitis C virus replicon
Authors: Kondoh Masuo , Yamagishi Yoshiaki , Yoshida Takeshi , Mizuguchi Hiroyuki , Sakamoto Naoya , Watari Akihiro , Yagi Kiyohito
Published: June 2021

An estimated 170 million people are infected with hepatitis C virus (HCV), which leads to chronic hepatic inflammation, hepatic fibrosis and hepatocellular carcinoma. Development of potent therapeutic strategies is critical for overcoming HCV, and efficient delivery of an HCV RNA replicon into cells is useful for basic and pharmaceutical studies. However, conventional assay systems for HCV infection have not been fully developed. Adenovirus (Ad) vectors have been widely used to deliver foreign genes to a variety of cell types and tissues in vitro and in vivo, as they are simple to prepare, grow to a high titer, and use for efficient transfer of genes into dividing and non‐dividing cells. However, Ad vector‐mediated assay systems for HCV replication have not been developed. In the present study, we developed an Ad vector containing an RNA pol‐dependent expression cassette and a tetracycline‐controllable RNA pol I‐dependent expression system. We prepared a hybrid promoter from the tetracycline‐responsive element and the RNA pol I promoter. Ad vector particles coding the hybrid promoter driven HCV replicon were prepared, and HCV RNA pol‐dependent HCV replication was confirmed in the cells transduced with the Ad vector coding HCV replicon. An inhibitor of HCV replication reduced HCV replication in the Ad vector‐transfected cells. To our knowledge, this is the first report on the development of an Ad vector‐mediated HCV replicon system.
TISSUE OXIDATIVE METABOLISM AFTER EXTREME HEMODILUTION WITH PEG CONJUGATED HEMOGLOBIN
Authors: Cabrales Pedro
Published: June 2021

NADH fluorometry was used as a non‐invasive technique to monitor changes in the energy state of intact tissue in the hamster window chamber model. Acute moderate isovolemic hemodilution was induced by two isovolemic hemodilution steps using 6% dextran 70kDa to 18% hematocrit (Hct). The protocol continued with an exchange transfusion to reduce erythrocytes to 75% of baseline (11% Hct) using either polyethylene glycol (PEG) maleimide conjugated hemoglobin 4 g/dl (PEG‐Hb) or a dextran (Dex70, 6 g/dl dextran 70 kDa). Systemic parameters, microvascular perfusion, functional capillary density, intravascular and interstitial oxygen tensions and intracellular NADH fluorescence were monitored. Blood pressure after extreme hemodilution was statistically significantly reduced for Dex70 when compared to PEG‐Hb. While microvascular blood flows were not different, the functional capillary density was significantly higher for PEG‐Hb compared to Dex70. Intravascular PO2 for PEG‐Hb was higher in arterioles compared to Dex70, but not different for either tissue or venular PO2. Cellular energy metabolism in the tissues was improved with PEG‐Hb. Hhemodilution to 18% Hct brings tissue oxygen delivery to the verge of inadequacy. Extreme hemodilution to 11% Hct produces tissue and anoxia, and high oxygen affinity PEG‐Hb (P50: 4 mmHg) and partially decreases anaerobic metabolism.
Organic Pollutants in Weddell Seals Blubber and Muscle Tissue from McMurdo Sound, Antarctica
Authors: Trumble Stephen J. , Robinson Eleanor , Usenko Sascha , Kanatous Shane
Published: June 2021

Blubber and muscle tissue samples were collected from different age‐class Weddell Seals (Leptonychotes weddellii) near McMurdo Sound, Antarctica in 2006. Tissue samples were analyzed for semi‐volatile organic compounds (SOCs) including current and historic‐use organochlorine pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs). SOCs were extracted from tissue samples utilizing pressurized liquid extraction with an in‐cell silica gel clean‐up and gel permeation chromatography. Extracts were analyzed using gas chromatographic mass spectrometry with electron capture negative ionization using isotope dilution and selective ion monitoring. Average triplicate recoveries using 1.5 g of whale blubber tissue and 0.25g muscle tissue was 86% ± 11%. Out of the 72 contaminants targeted in Weddell seal tissues, 10 individual SOCs were recovered in the L. dorsi whereas 22 were recovered from blubber. The most commonly recovered SOCs from all samples were cis‐chlordane, trans‐nonachlor, cis‐nonachlor, DDTs, DDEs, PCBs, and dieldrin. PBDE 47 also was recovered from the blubber of adults. DDE and DDT made up the majority of the SOCs recovered in both skeletal muscle and blubber; adult female DDT‐DDE concentrations > juveniles > adult males > pups (ANOVA, P < 0.05). DDT:DDE from adult Weddell seals reveal similar trends to Arctic species.
The Role of Peroxisome Proliferator‐Activated Receptor Alpha (PPARá) on Renal Prolyl Hydroxylase Domain‐Containing Proteins (PHD) in Response to High Salt Diet
Authors: Ozurumba Ezinne , Mathew Omana , Ranganna Katsuri , Oyekan Adebayo
Published: June 2021

PPARá is a transcription factor that modulates renal function and protective in cardiorenal diseases. PHD is an oxygen sensor that regulates oxygen consumption in the kidney. Upon injury, PHD expression is downregulated as an adaptive response reprogramming glucose metabolism to more anerobic ATP production through PPARá activation. However, the role of PPARá in regional PHD expression under basal and stimulated conditions is unknown. Since PPARá and PHD1 are differentially but reciprocally expressed in the renal cortex (C) and medulla (M), this study tested the hypothesis that salt loading promotes a regional adaptive reduction in PHD expression by a mechanism dependent on PPARá. In PPARá WT and KO mice placed on low (0.03% NaCl; LS) or high salt (8% NaCl, HS) diet for 9 days, water and sodium balance were greater in mice placed on HS diet but these are not different between WT and KO mice. PHD1 expression was greater in the M than the C (93+8%) In WT mice but lower in KO mice (25+3%) under LS condition. HS diet did not affect PHD1 expression in the C or M of WT mice but PHD1 expression was reduced equally (52+6%) in the C and M of KO mice. HS diet effect in KO mice was such that reduction in PHD1 expression was greater in the M (81+8% vs 54+5% [cortex]). These data revealed the M as the site of PPARá/PHD interaction and that salt load elicited a region‐selective decrease in PHD1 expression in the renal medulla by a PPARá‐independent mechanism.
TonEBP/OREBP is activated by hypoxia: Role in renal Ischemia and Reperfusion
Authors: IRARRAZABAL CARLOS E , Villanueva Sandra , Michea Luis , Carreno Juan E , Lozano Mauricio , Cortes Andres
Published: June 2021

The present paradigm describe that hypertonicity in the kidney medulla increases activity of the transcription factor TonEBP/OREBP, resulting in cell protection. Additionally, kidney medulla is also hypoxic (10–18mmHg), however there is not information about the effect of hypoxia on TonEBP/OREBP. Using in vivo and in vitro models, we evaluate the effect of low partial pressure of oxygen (PaO2) on TonEBP/OREBP activity. We find that 1) Reduction in PaO2 increased the TonEBP/OREBP expression in primary cell culture from medulla of rat kidney and HEK293 cells. 2) Anoxia increased the transcriptional activity and nuclear translocation of TonEBP/OREBP in HEK293 cells. 3) TonEBP/OREBP Knock down increased the cell death induced by hypoxia. 4) TonEBP/OREBP and HIF‐1α expression were increased in kidney (cortex and medulla) from rat subjected to experimental model of ischemic and reperfusion (I/R). 5) Experimental I/R increased the TonEBP/OREBP‐target gene aldose reductase (AR). 6) TonEBP/OREBP activators, ATM and p110α, were induced in rat kidney (cortex and medulla) in the same timing of TonEBP/OREBP. These results demonstrate by first time the TonEBP/OREBP is induced by hypoxia and it has a potential protective role against ischemic damage.
Dexamethasone regulates a noncanonical hormone response element in the endothelin‐1 (edn1) gene
Authors: Stow Lisa R , Gumz Michelle L , Voren George E , Wingo Charles S , Cain Brian D
Published: June 2021

The mineralocorticoid aldosterone stimulates edn1 mRNA in renal collecting duct (CD) cells by a mechanism involving the mineralocorticoid receptor (MR) and the glucocorticoid receptor (GR). The goal of the present study was to determine if dexamethasone, a synthetic glucocorticoid, regulated edn1 in murine inner medullary CD (mIMCD‐3) cells. Dexamethasone (1 μM) induced a 3.48±0.19 fold increase in edn1 mRNA, whereas aldosterone (1 μM) induced a 2.53±0.17 fold increase in edn1 mRNA. Similar results were obtained from mpkCCDc14 cells. RU486 inhibition of GR completely blocked dexamethasone action on edn1. Similarly, 24h transfection of siRNA against GR blunted approximately 50% of edn1 mRNA. However, blockade of MR with either spironolactone or siRNA had no effect on dexamethasone‐induced edn1. DNA affinity purification studies revealed that dexamethasone or aldosterone resulted in GR binding to the same hormone response element in the edn1 promoter. The edn1 hormone response element is a noncanonical sequence containing 3 binding half‐sites. Mutation analysis revealed a single high affinity half‐site that was important for both MR and GR binding. In summary, dexamethasone regulates CD edn1 expression and this interaction may be relevant for the clinical use of dexamethasone. Support by American Heart Association fellowship to LRS and NIH R01DK82680 to BDC and CSW.
Cardiorespiratory effects of chronic hyperoxia in neonatal rats
Authors: van Heerden Eliza S , Bavis Ryan W
Published: June 2021

Rats reared in hyperoxia (60% O2) from birth exhibit abnormal respiratory control: normoxic ventilation is reduced at 4 and 7 d of age (i.e., P4 and P7), but not at P14, and the hypoxic ventilatory response (HVR) is blunted at P7 and P14, but not at P4 (Bavis et al. J Appl Physiol 109: 796–803, 2010). To determine whether these respiratory deficits impair tissue O2 delivery, arterial O2 saturation (SpO2) and heart rate were measured by pulse oximetry at P4 and P14 for rats reared in 60% O2 (Hyperoxia) or 21% O2 (Control). At P4, Hyperoxia rats had lower SpO2 (93.0±1.3 vs. 98.8±0.2%; mean±SEM) and lower heart rates (332±10 vs. 380±9 bpm) while in normoxia than Controls. SpO2 was also lower in Hyperoxia rats at P14, but to a lesser extent (97.0±0.4 vs. 98.7±0.1%); heart rate was not different from Controls at P14. When exposed to hypoxia (12% O2), the drop in SpO2 was greater in Hyperoxia rats than Controls; however, this difference was more pronounced at P14 (ΔSpO2 = −42±2 vs. −24±2% in Controls), consistent with the blunted HVR of Hyperoxia rats at this age. Hyperoxia rats also had lower hematocrits at P4 and P14 and smaller hearts at P4. Therefore, Hyperoxia rats do not appear to compensate for low SpO2 and heart rate by increasing blood O2 capacity or stroke volume. Together, these data suggest that tissue O2 delivery is compromised during both normoxia and acute hypoxia in neonatal rats reared in hyperoxia. Supported by NIH grant HL‐083972.
New theory of breathing control: a complex model integrates multi‐systems
Authors: Sun Xingguo , Guo Zhiyong
Published: June 2021

INTRODUCTION

Although many prior studies have addressed the mechanism of breathing control, this topic remains a challenging and complex research area. Most prior studies have utilized average measurements over a period of time, however Band et al reported the ΔpH(PCO2)/Δt was a breathing control factor.

New Theory

Lung breath generated oscillations of arterial O2, CO2 and H+ signals via carotid body and aorta arch (“fast”) and medullary chemo‐receptors (“slow”,~20s) are integrated in the respiratory control center to stimulate the next (another) breath. The peripheral chemo‐receptors (carotid body and aorta arch) are sensitive to oscillation information [ΔPO2(SO2)/Δt, ΔPCO2/Δt, Δ[H]/Δt] without time delay, central chemo‐receptors are sensitive to the mean (averaged) level of the signals with ~20s delay due to the oscillation information blunted by the tissue diffusing step. The effect of central sensors control the “GAIN” of oscillation information from the sensors at carotid body and aorta arch and/or central integrative system. The respiratory integrative center in the central nervous system integrates the input from these fast and slow sensors, and combines that information from the two sensors to generate the next breath.

CONCLUSIONS

Lung breath generated O2, CO2 and [H+] oscillations generates the next breath via two fast sensors (carotid and aorta) and central medullary censor control the “gain” of breath with longer time delay in collaboration with an integrative respiratory center.
Global proteomic profiling of vasopressin‐dependent nuclear localization
Authors: Schenk Laura Katharina , Pisitkun Trairak , Miller Lance , Sandoval Pablo , Hoffert Jason , Knepper Mark
Published: June 2021

Vasopressin regulates the expression of many genes in the renal collecting duct. To identify mediators, we have carried out LC‐MS/MS profiling of cytoplasm, soluble nuclear compartment, and nuclear pellet of collecting duct mpkCCD cells. Stable isotope labeling (SILAC) was used for relative quantification of tryptic peptides in vasopressin‐treated (1h dDAVP, 0.1nM) compared to control cells. There were no measurable differences in total protein content. We identified 5776 peptides corresponding to 1074 proteins in the soluble nuclear compartment. 49 proteins were either decreased or increased in abundance (SILAC isotope ratio ≤0.7 or ≥1.3). In the nuclear pellet, we identified 57749 peptides (1383 proteins). 224 of these showed altered abundance in presence of dDAVP. Altered proteins are candidates to play a regulatory role on gene expression upon dDAVP treatment, e.g. regarding aquaporin‐2, whether changes are due to nuclear translocation or post‐translational modification. One example is the CREB‐regulated transcription coactivator 1 (Crtc1) protein, which is increased in the soluble nuclear compartment in response to vasopressin.
Structural Basis For Antigenic Peptide Precursor Processing by the Endoplasmic Reticulum Aminopeptidase ERAP1
Authors: Nguyen Tina T , Chang Shih‐Chung , Evnouchidou Irini , York Ian , Zikos Christos , Rock Kenneth L. , Goldberg Alfred L , Stratikos Efstratios , Stern Lawrence J
Published: June 2021

ERAP1 trims antigen precursors to fit into MHC class I proteins. To perform this function, ERAP1 has unique substrate preferences, trimming long peptides while sparing shorter ones. To identify the structural basis for ERAP1's unusual properties, we determined the X‐ray crystal structure of human ERAP1 bound to bestatin. The structure reveals an open conformation with a large interior compartment. An extended groove originating from the enzyme's catalytic center can accommodate long peptides and has features that explain ERAP1's broad specificity for antigenic peptide precursors. Structural and biochemical analysis suggest a mechanism for ERAP1's length‐dependent trimming activity, whereby binding of long but not short substrates induces a conformational change with reorientation of a key catalytic residue towards the active site. ERAP1's unique structural elements suggest how a generic aminopeptidase structure has been adapted for the specialized function of trimming antigenic precursors.
An economical technique for replicating biocompatible microfabricated devices with rigid high aspect ratio features
Authors: Cookson Scott Warren , Saldivar Enrique
Published: June 2021

Here we report the development of an economical replication technique for generating high‐resolution copies of microfabricated devices containing high aspect ratio features. The method is highly reproducible and compatible with devices manufactured using any standard microfabrication technology, provided that the device geometry can be fully captured by replica molding. First, a polydimethylsiloxane (PDMS) replica of the original device is generated using soft lithography techniques. Second, a slow‐cure epoxy is cast against the PDMS replica to recreate the original geometry with submicron resolution. Next, a copper base layer is sputtered upon the flexible epoxy scaffold and nickel is electrodeposited to increase durability. Finally, thin films of titanium and gold are deposited to confer biocompatibility. As this method relies on the use of inexpensive polymers and commercially‐established metallization techniques, it is well‐suited for the economical mass replication of high‐value microfabricated parts. The technique is demonstrated by generating accurate replicas of micron‐scale silicon structures with aspect ratios of 1:125. Funding source: Gary & Mary West Foundation
Functional studies with Ki‐1/57 protein and structural analyses of human protein RACK1
Authors: de Almeida Gonçalves Kaliandra , Borges Julio Cesar , da Silva Julio Cesar , Saito Angela , Bressan Gustavo Costa , Torriani Iris Concepcion Linares , Kobarg Jorg
Published: June 2021

The Ki‐1/57 protein has been discovered through the cross reactivity of the monoclonal antibody Ki‐1 in Hodgkin lymphoma cells. Recent studies have identified sumoylation as important post‐translational modification that regulates the biological functions of protein. In sumoylation, SUMO (small ubiquitin‐like modifier) is covalently attached to a lysine residue in a ΨKXE sequence (where Ψ is a large hydrophobic residue and X represents any amino acid). Furthermore, we found that Ki‐1/57 is a target for sumoylation in vitro and in vivo. The study objective was to generate mutants of the protein Ki‐1/57 to try identify which lysine residue are covalently attached to Sumo. RACK1(receptor of activated kinase 1) was isolated in a yeast two‐hybrid screen to interact with the protein Ki‐1/57. We performed a biophysical analysis of human RACK1 with the aim of obtaining low resolution structural information. Small angle X‐ray scattering (SAXS) experiments demonstrated that human RACK1 is globular and monomeric in solution. Fluorescence spectroscopy experiments after titration of Ki‐1/57(122–413) in solution with RACK1 and sedimentation equilibrium experiments showed that this association is strong.

Supported by: FAPESP, CNPq
Higher energy expenditure but lower physical activity levels with increasing obesity
Authors: DeLany James P , Jakicic John M , Kelley David E , Hames Kazanna C , Goodpaster Bret H
Published: June 2021

The role that physical activity plays in obesity is not clear. Furthermore, there is a dearth of information regarding the contribution of energy expenditure (EE) to severe obesity. We measured EE in 177 individuals ranging from lean to severely obese. We measured total EE (TEE) by doubly labeled water, resting EE (REE) by indirect calorimetry, activity EE (AEE) by difference, and time spent in physical activity by multisensor activity monitors.

All components of EE were elevated in obese individuals. After adjusting for differences in body composition, REE was similar in all groups. The strong relationship observed between AEE (and TEE) and body weight in the lean was blunted in the obese, particularly the Class III obese. Obese individuals spent less time engaged in physical activity (2.7 ± 1.3 vs.1.2 ± 1.0 hr/d in lean and Class III), and more time in sedentary behaviors (20.7 ± 1.5 vs. 21.8 ± 1.1 hr/d in lean and Class III).

In conclusion, although obese individuals have elevated EE, adjusted REE is normal. Using a combination of state of the art techniques allowed us to demonstrate that obese have a lower TEE and AEE in relation to their increased body weight, which can be explained by less time spent in physical activity and more time in sedentary behaviors than lean individuals. These findings support a role for low physical activity in obesity, and suggest that inactivity is a target for prevention.

Funded by Commonwealth of Pennsylvania Department of Health
Genetic variation in the vitamin D receptor (VDR) and the plasma proteome
Authors: Bailo Bibiana Garcia , Badawi Alaa , El-Sohemy Ahmed
Published: June 2021

Vitamin D deficiency has been linked to numerous diseases. 1,25(OH)2D, the active vitamin D form, binds to the nuclear vitamin D receptor (VDR) and affects target gene expression in multiple pathways. However, it is not known if genetic variants in VDR affect plasma protein levels. The objective was to explore associations between VDR variants and 54 plasma proteins belonging to disease‐associated pathways in healthy young adults (n=488). 16 genetic variants across VDR were extracted from genome‐wide data available for the study cohort. Protein concentrations were measured by a multiple reaction monitoring HPLC‐MS/MS assay. Associations between proteins and variants were explored by linear regression with an additive inheritance mode. We found 32 significant associations. The strongest association (p=5.06×10−5) was observed between rs2283342 and inter‐α‐trypsin inhibitor HC (IT) (r2=0.03, β= −0.03±0.01), a serine protease inhibitor involved in inflammation. We then examined whether serum 25(OH)D, a marker of vitamin D status, affected any associations. 25(OH)D modified the association between rs2283342 and IT, as well as associations between rs2228570 (Fok1) and several apolipoproteins. These results suggest a role for vitamin D in disease associated pathways such as inflammation and lipid metabolism. Research support from the Advanced Foods and Materials Network.

Grant Funding Source: Advanced Foods and Materials Network
Effect of zinc (Zn) deficiency on nutrient delivery to the rat fetus
Authors: Hanna Lynn A , Clegg Michael S , Gedestad Michael D , Keen Carl L
Published: June 2021

Maternal Zn deficiency can result in fetal growth retardation and reductions in fetal insulin‐like growth factor‐1 (IGF‐1). Fetal growth is driven by IGF‐1 but is also influenced by the maternal nutrient supply. Accordingly, one aim of the current study was to examine the delivery of nutrients across the placenta under conditions of Zn adequacy and deficiency. Beginning at conception rat dams consumed a Zn adequate (25 ppm Zn) or Zn deficient (0.3 ppm Zn) diet, while a third group of rats were restricted in the amount of adequate diet they received to a level equivalent to the diet consumed by the Zn deficient dams. Dams were anesthetized at GD 19.5 with isoflurane and injected with 10 μCi/kg of [14C] methyl‐aminoisobutyric acid, an amino acid analog. After 7 min, dams were euthanized and maternal serum, fetuses, and placentas were collected. Fetuses were homogenized in PBS. Aliquots of homogenate and maternal serum were precipitated with trifluoroacetic acid, and the supernates were measured for DPMs. Maternal DPM per ml serum and DPM per g fetus was similar among the groups. These data suggest that amino acid delivery was unaffected by Zn deficiency. Our previous finding indicated that fetal liver IGF‐ 1 levels are attenuated during maternal Zn deficiency. When coupled with the current findings, the data suggest that the fetal regulation of its own growth is directly compromised under conditions of Zn deficiency. This work was supported by Center for Health and Nutrition Research.
Vitamin E intake and serum concentrations in older Black and White Americans using National Health and Nutrition Examination Survey (NHANES) 2003–2006 population
Authors: Toft-Dupuy Tucker , Tangney Christy , Gregoire Mary , Bacon Cheryl
Published: June 2021

Few data are available describing the primary sources of vitamin E intake among non‐Hispanic blacks and whites. The objectives of this research were to: assess current dietary vitamin E intakes of older (≥ 50 y) non‐Hispanic black and white Americans; and describe primary food sources of alpha‐tocopherol (AT) in the diets of these adults. Based on 24‐h recalls in NHANES 2003–2006, dietary AT intakes of 2355 whites and 707 blacks were less than half the recommended dietary allowance of 15 mg AT. Men had lower dietary AT intakes than those of women and blacks had lower intakes as compared to those of whites for the first day of recalls after multivariate adjustments (both p<0.03). Among blacks, ready‐to‐eat cereal (7.2%), potato chips, corn chips, popcorn (6.8%), and nuts, seeds (6.6%) were the major contributors of vitamin E while for whites, these were ready‐to‐eat cereal (12.9%), nuts, seeds (9.6%), and mixtures mainly from grains (7.1%). In a subset of 1223, fasting serum AT did not differ by race (p=0.065) but gamma‐tocopherol concentrations were modified by race and sex interactions of which black females had the highest concentrations (p<0.044). Dietary AT intake remains inadequate among older American adults despite serum AT levels in the normal range. Encouraging the intake of nutritious vitamin E dense foods also low in PUFA such as ready‐to‐eat cereals and dark green vegetables may correct this.
Vitamin D‐Casein fortification of cheese and its bioavailability
Authors: Al-khalidi Banaz , Vieth Reinhold , Rousseau Derick , Chiu Winnie , Cockburn Moira , Bromberg Irvin
Published: June 2021

Widespread vitamin D insufficiency worldwide and increased vitamin D intake recommendations from the Institute of medicine (IOM) emphasize a need to expand vitamin D fortification practices. IOM's 2011 report almost tripled the dietary guidelines for vitamin D: from 200 IU up to 600 IU daily. Vitamin D fortification practices vary and are largely voluntary in Canada and the US. Vitamin D‐fortified cheddar cheese using emulsified vitamin D3 was found to have comparable bioavailability of vitamin D with liquid supplement. Our objectives are to establish a new protocol for vitamin D fortification via incorporation of vitamin D in casein; and to evaluate the effect of baking on bioavailability. Vitamin D3 retention in lab‐scale mozzarella cheese was 54% and the loss of vitamin D3 into the whey was 1.6%. The remaining vitamin D3 was lost during mozzarella cheese processing. Large‐scale mozzarella cheese fortified with vitamin D3 will be used to cook pizza that will be consumed by study participants. Approximately 120 subjects will be randomized to weekly servings of pizza baked with fortified mozzarella cheese either at 200 IU/serving or 28,000 IU/serving. Vitamin D levels will be compared between groups. Vitamin D fortification of cheese is a good strategy to increase intakes and may benefit public health as well as dairy industry practices.

Grant Funding Source: Dairy Farmers of Canada
Whey protein based microencapsulation for protection of Lactobacillus acidophilus in yogurt
Authors: Guo Mingruo , Zheng Zhe , Zhang Tiehua , Jiang Yujun
Published: June 2021

Whey protein based microencapsulation of probiotics such as Lactobacillus acidophilus NCFM was developed using polymerized whey proteins (PWP) in comparison with the one using sodium alginate (SA) as a control. The entrapment yield for the PWP method (89.3±4.8%) was significantly higher (p < 0.01) than the control method (73.2±1.4%). Viable counts of the culture after artificial digestions were 3.63±1.48×104, 1.83±1.10×104 and 1.35±0.72×102 cfu/mL for the PWP capsulated sample, SA treated cells and non‐microencapsulated culture, respectively. Cows’ and goats’ milk were fermented with four groups of cultures, respectively: NCFM (A); NCFM, L. delbrueckii subsp. bulgaricus and S. thermophiles (ABS); ABS and SA capsulated NCFM (ABS+SAA); ABS and PWP treated NCFM (ABS+PWPA). The viable counts of the culture decreased by 5 log counts for the yogurt fermented only with NCFM by the end of week 10, and it decreased by 8 log counts for the yogurt prepared with ABS. However, NCFM counts for yogurt samples prepared with ABS+SAA or ABS+PWPA decreased by 4 or 3 log counts, respectively. Results showed that polymerized whey protein based microencapsulation seems to be an effective technique for protection of this L. acidophilus in yogurt products. This research was financially supported by USDA Hatch (024695).
Effect of infection and selenium status on the selenotranscriptome
Authors: Neidich Scott Daniel , Golly Elizabeth Maria , Beck Melinda A
Published: June 2021

Previous work in our laboratory has shown that mice deficient in selenium develop heart pathology when infected with a normally benign coxsackievirus (CVB3/0). Many of the 24 selenoproteins present in mice are involved in protection from oxidative stress, which may be involved in limiting pathology post infection. In order to determine the effect of Se status and infection on the selenotranscriptome, we fed mice either a Se‐adequate or Se‐deficient diet for 4 weeks, followed by infection with CVB3/0. Uninfected mice in each diet group served as controls. We measured mRNA levels for 15 selenoproteins in the liver and heart daily for 10 days post infection. Selenoprotein mRNA expression was lower in Se‐deficient mice for GPx1, Sel M, Sel R, and Sel H independent of infection. During infection, mRNA levels for GPx1, GPx4, TR1, Sel K, and Sel N all exhibited increased expression, whereas GPx3, TR2, Sel M, and Sel W exhibited decreased expression, regardless of selenium status. These findings suggest that mRNA levels for a number of selenoproteins are influenced by infection and thus may play a role in protection and/or recovery from infectious disease.

Grant Funding Source : NIH
Effects of selenium supplementation and chronic inflammation on bone microarchitecture and strength in mice
Authors: Girma Abiy , Nekatebeb Hana , Peterson Sandra , Smith Brenda J , Stoecker Barbara J
Published: June 2021

Timed‐pregnant C57BL6 mice were fed a Torula yeast selenium‐depletion diet from the final days of gestation through lactation. At 23 days of age, pups were weaned and randomly assigned to the depletion diet or to diets supplemented with 0.2, 2 or 4 mg/kg diet of Se added as sodium selenate for 14 weeks. At 96–98 days of age mice were randomly assigned to placebo or to lipopolysaccharide (E. coli Serotype 0127:B8) treatment to produce chronic inflammation. Time release pellets (0 or 0.1 μg/g body weight/d) were implanted subcutaneously. Body weight was reduced by LPS 14 days after implantation but differences were no longer significant by 28 days. Bone microarchitecture was evaluated in tibia and 4th lumbar vertebra (L4) and force to compress was estimated on trabecular cores using finite element analysis (Scanco μCT40). Bone volume/total volume, connectivity density, and trabecular number were significantly reduced by LPS treatment while trabecular separation was increased by LPS treatment in both bones. In spine significant interactions affected size‐independent stiffness and von Mises stresses. Overall, chronic inflammation at a level that does not produce severe body weight loss still significantly impaired measures of bone microarchitecture and strength. (Supported by Oklahoma Center for Advancement of Science and Technology).