bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing Glucocorticoid Receptor Polymorphisms in Obese Populations
Authors: Bonnet Claude‐Luvier , Dowdye Ayanah , Cohen Brian D.
Published: June 2021

The glucocorticoid receptor (GR) is part of a family of nuclear receptors that control gene expression. In the presence of the steroid hormone cortisol certain genes are expressed; the products of which control, among other things, blood pressure, serum triglycerides, and blood sugar which are often elevated in patients with obesity. Specific polymorphisms of the GR and other regulators of either GR (or the closely related mineralocorticoid receptor) such as heat shock protein 90 (HSP90) and 11β‐hydroxysteroid dehydrogenase type 1 (11βHSD1) have been found in our labs and others to be present at a higher frequency in obese populations. Our current research is investigating polymorphisms in these genes as well as the gene encoding the FK506 binding protein (FKBP) which works in conjunction with HSP90 to negatively regulate GR activity. It is hypothesized that polymorphisms may exist in the FKBP51 gene that would result in decreased activity of FKBP and subsequent overactivity of GR resulting in phenotypic hypercortisolemia. Analysis of the FKBP51 single nucleotide polymorphism RS1360780 showed a correlation with serum triglycerides, blood pressure, BMI, and weight regain in bariatric surgery patients. This finding in combination with previous results will lead to a better understanding of the genetic underpinnings of obesity and may reveal novel therapeutic approaches.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
In vivo Effects of Adipose‐Specific Deletion of Jagged 1 in Mice Administered a High Fat Diet
Authors: Langlais Audrie
Published: June 2021

Adipose tissue is a major site of lipid metabolism that works synergistically with other organs to regulate whole body energy homeostasis. Adipose tissue also modulates metabolism by secretion of adipokines such as leptin and adiponectin. Abnormalities in the differentiation and function of mature fat cells (adipocytes) are linked to metabolic disease. The evolutionarily‐conserved Notch signaling pathway is necessary for the differentiation of all cell types including adipocytes. Both inhibition and activation of Notch 1 interfere with adipose remodeling in response to nutritional stress. Although activation of the canonical Notch pathway requires binding to one of its transmembrane ligands such as Jagged‐1, the importance of the ligand itself in regulating adipose development and function has been poorly studied. Furthermore, the ability of the Jagged1 ligand to regulate adipocyte cell fate decisions directly through translocation of its intracellular domain (ICD) into the nucleus is unknown. To address these questions regarding the role of Jagged1 in maintaining metabolically healthy adipose, we generated a novel Cre‐mediated conditional knockout murine strain (ap2‐Jag1tm2Grid) to study the impact that jagged1 gene dosage has on visceral adipose depots under conditions of dietary stress. The ap2‐Jag1tm2Grid line produces progeny with three possible Jagged‐1 genotypes that result in either wild type, haploinsufficient or complete loss of Jagged1 expression in mature adipocytes. Physiological and biochemical measurements conducted on young mice representing all three genotypes after administration of either a high fat (“Western”) or standard diet for 5 weeks support our hypothesis that complete or partial loss of Jagged1 in adipocytes is detrimental to the ability of adipose to remodel and function normally in response to the intake of dietary lipids. Differences among the cohorts regarding weight gain, % visceral fat mass, fasting blood glucose, serum lipids and expression of adipokines leptin and adiponectin support a role for Jagged‐1 in maintaining proper adipose growth and metabolism. Data from this study may lead to a better understanding of how the expression level of Jagged1 influences an individual's susceptibility to obesity and metabolic disease.

Support or Funding Information

Deena J. Small, University of New England Department of Chemistry & Physics

Woon Yuen Koh, University of New England Department of Mathematical Sciences

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Sphingomyelin‐Cholesterol Complexes In Plasma Membranes
Authors: Endapally Shreya , Frias Donna , Tomchick Diana , Radhakrishnan Arun
Published: June 2021

Sphingomyelin(SM) and cholesterol are lipids that are critical for the function of animal cells. Interplay between these two lipids is important for maintaining integrity of the myelin sheath that encases axonal cells and for maintaining functionally distinct pools of cholesterol in the plasma membranes of fibroblast cells. The nature of the interaction between SM and cholesterol has been long debated, with proposals ranging from complexes of the two lipids to no specific interaction between these two lipids.

Here, we have developed a sensor to examine the interaction between SM and cholesterol in animal cell membranes. Our sensor is derived from a fungal toxin, ostreolysin A (OlyA). We find that OlyA binds to membranes of CHO‐K1 hamster cells when they contain both SM and cholesterol, but not when levels of either lipid are diminished by treatment with sphingomyelinase (which degrades SM) or cyclodextrin (which depletes cholesterol). In model membranes, OlyA shows no binding to dioleoyl‐phosphatidylcholine – cholesterol membranes even when the cholesterol concentration exceeds 50 mole%. Also, OlyA shows no binding to SM‐containing membranes when epicholesterol (a diasteromer of cholesterol) is present at concentration exceeding 50 mole%. Using X‐ray crystallography, we studied the interaction of OlyA with SM and cholesterol at the atomic level. This structural analysis combined with detailed mutagenesis led us to a single point mutation in OlyA that abolishes its cholesterol specificity while retaining SM specificity. Comparing the X‐ray structures of these two versions of lipid‐bound OlyA combined with ligand docking simulations revealed two distinct binding modes of OlyA to SM. We propose that one of these SM conformations reflects a complex with cholesterol. Studies in live cells show that this pool of SM/cholesterol complexes in plasma membrane is maintained at a constant level across a large range of cholesterol concentrations.

Support or Funding Information

This work was supported by the Welch Foundation (I‐1793) and the American Heart Association (12SDG12040267)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Minocycline Inhibits PDGF‐BB‐induced Human Aortic Smooth Muscle Cell Proliferation and Migration via Induction of RECK
Authors: Higashi Yusuke , Srinivas Mummidi , Sukhanov Sergiy , Yoshida Tadashi , Delafontaine Patrice , Chandrasekar Bysani
Published: June 2021

Minocycline is an FDA‐approved tetracycline antibiotic that exerts anti‐inflammatory and anti‐apoptotic effects independent of its bactericidal activity. For example, it attenuates neointima formation after arterial injury and atherosclerotic plaque development in an animal model of diet‐induced atherosclerosis via inhibition of smooth muscle cell (SMC) proliferation and migration; however, the molecular mechanisms underlying this inhibition are not completely known. Here we investigated whether minocycline inhibits PDGF‐BB‐induced primary human aortic SMC (HASMC) proliferation and migration in vitro. Our results show that PDGF‐BB stimulates proliferation (~2.92‐fold, P<0.05) and migration (~1.8‐fold, P<0.05) of HASMC via a redox‐sensitive mechanism involving NOX2 (inhibited by gp91dstat) and NOX4 (inhibited by GKT137831). Reversion‐Inducing‐Cysteine‐Rich Protein with Kazal Motifs (RECK) is a cell surface expressed, membrane anchored matrix metalloproteinase inhibitor. For the first time, our results show that PDGF‐BB downregulates RECK expression in a time‐dependent manner (by ~80% at 6 h, n=3, P<0.01), but induces miR‐221 and miR‐222 expression (~1.8‐fold and ~2.23‐fold, respectively). The reporter assays revealed that both miRs bind the 3′UTR of RECK mRNA, inhibiting its expression by ~50% (P<0.01). Supporting these observations, transduction of miR‐221 or miR‐222 mimics suppress RECK expression, but their antagomirs reverse PDGF‐BB‐induced inhibition of HASMC proliferation and migration. Further investigations revealed that PDGF‐BB activates the redox‐sensitive nuclear transcription factors NF‐kB and AP‐1 in HASMC, and shRNA directed against the AP‐1 subunit c‐Jun and the p65 subunit of NF‐kB each inhibit PDGF‐BB‐induced miR‐221 or miR‐222 expression, suggesting that PDGF‐BB suppresses RECK expression in HASMC in part via AP‐1‐ and NF‐kB‐dependent miR‐221 and miR‐222 induction. Notably, minocycline increases RECK expression dose‐dependently within the therapeutic dose of 1–100 μM, and inhibits PDGF‐BB‐induced HASMC proliferation and migration. Intriguingly, silencing RECK reverses the inhibitory effects of minocycline on PDGF‐BB‐induced migration and proliferation. Together, these results demonstrate that PDGF‐BB downregulates RECK expression in HASMC via AP‐1‐ and NF‐kB‐dependent miR‐221 and miR‐222 induction, and minocycline reverses PDGF‐BB‐induced ROS generation, miR‐221 and miR‐222 induction, and RECK suppression. These findings suggest that the induction of RECK is one of the mechanisms by which minocycline exerts vasculoprotective effects.

Support or Funding Information

NIH R01‐HL‐070241 (PD)VA Merit Award I01‐BX002255 (BC)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Absence of Heme Oxygenase‐1 Accelerates Smooth Muscle Cell Gene Expressions during Embryoid Body Development from Mouse Embryonic Stem Cells
Authors: Jiang Wei‐Cheng , Lai Yan‐Liang , Lin Chen‐Yu , Yet Shaw‐Fang
Published: June 2021

Heme oxygenase (HO)‐1 is well known as a stress response protein, playing an important role for protecting cells and tissues from injury with its antioxidative and anti‐inflammatory properties. Although it possess crucial cytoprotective ability against physiological stress, the functions of HO‐1 in embryonic stem cell (ESC) differentiation remain to be elucidated. In previous study, we indicated that in the absence of HO‐1, induced pluripotent stem (iPS) cells are more sensitive to oxidant stress‐induced cell death and more prone to lose pluripotent markers without LIF. To investigate the role of HO‐1 in ESC differentiation and to eliminate the controversy of potential gene defects in iPS cells, we attempted to set up mouse HO‐1 knockout ESC lines from HO‐1 knockout blastocysts. Under the 3‐dimensional embryoid body (EB) formation from wild type D3 and HO‐1 knockout ESCs, we showed that at an early time point after EB differentiation, a lack of HO‐1 led to enhanced ROS level, accompanied with upregulations of master mesodermal regulator brachyury and endodermal marker GATA6. Furthermore, critical smooth muscle cell (SMC) transcription factor serum response factor and its coactivator myocardin were increased. Moreover, HO‐1 deficiency augmented Smad2 expression in ESCs and EBs, indicating that Smad2 not only mediates mesendoderm differentiation of mouse ESCs but also SMC development. Taken together, absence of HO‐1 contributed to higher level of mesodermal and SMC regulators, leading to accelerated and enhanced SMC marker expressions. Our results demonstrated a previously indeterminate function of HO‐1 in regulating SMC gene expressions during ESC‐EB development. More significantly, this finding may provide a novel approach to enhance SMC differentiation from ESCs.

Support or Funding Information

National Health Research Institutes and Central Government S&T grant, Taiwan (106‐0324‐01‐10‐07), Ministry of Science and Technology of Taiwan (MOST 104‐2320‐B‐400‐006‐MY3 and MOST 106‐3114‐Y‐043‐021), and National Health Research Institutes of Taiwan (CS‐106‐PP‐05).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
A pharmacological model of TRPA1‐mediated nociception in zebrafish larvae for therapeutic discovery
Authors: Ko Mee Jung , Ganzen Logan C. , Leung Yuk Fai , van Rijn Richard M.
Published: June 2021

Nearly 50 million people in the United States currently suffer from chronic pain disorder (CPD). CPD accompanies unrelieved and persistent pain lasting longer than 3 months. For many patients, current medications inadequately treat their symptoms or come with significant adverse effects, suggesting the need to find novel treatments. One novel therapeutic target for CPD is a calcium channel called Transient Receptor Potential channel subfamily A1 (TRPA1). However, the lack of robust in vivo models to investigate TRPA1 has been perceived as a challenge to drug discovery. Zebrafish model has been utilized for discovering neuroactive compounds. Their increased locomotive/swimming behavior upon TRPA1 activation has been interpreted as a nociceptive‐like phenotype. To increase the robustness of this model, we employed a less volatile and less neurotoxic TRPA1 agonist. We validated TRPA1‐mediated responses by a selective TRPA1 antagonist. Here, we first characterized the basic pharmacology of mouse and zebrafish TRPA1 ligands in HEK293 cells transiently expressing TRPA1. We used FLIPR®‐based calcium assay to record calcium influx, which is a measure of TPPA1 function. Additionally, we measured swimming behavior of zebrafish larvae (5 days post‐fertilization) following TRPA1 activation using a ViewPoint Zebrabox. In our studies, treatment with 100 μM TRPA1 agonist (ASP7663) increased calcium influx in HEK293 cells and swimming behavior of zebrafish larvae. Pre‐incubation of TRPA1 antagonist (HC030031) ablated in vitro calcium influx in a dose‐dependent manner and TRPA1‐mediated locomotive behavior in zebrafish larvae. Our findings validate that the zebrafish larvae can act as an in vivo model to investigate TRPA1‐targeted drugs for CPD. The increased robustness of our model will allow for a successful target‐based drug screening.

Support or Funding Information

The current research has been funded by a Collaborative Research Award from the Purdue Institute of Integrative Neuroscience (PIIN).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Cinnamic Acid Derivatives as Novel Antinociceptives for Acute Pain
Authors: Priebe Alaini , Hunke Megan , Hyde Olivia , Martinez Wuilian , Capellen Caleb , Sonawane Yogesh , Chandra Surabhi , Natarajan Amarnath , Pattabiraman Mahesh
Published: June 2021

Search for alternate pain medications has gained more importance in the past few years due to nervous system related side‐effects with opioids, gastrointestinal dysfunction associated with non‐steroidal anti‐inflammatory drugs (NSAIDs), and cardiovascular anomalies with cyclo‐oxygenase‐2 inhibitors (COX‐2). Phytomedicine has been quite effective for treatment of pain, as these have been used for generations in regional communities, and tend to lack any major side‐effects. A dimer of cinnamic acid, Incarvillateine (INCA), derived from the Chinese herb Incarvillea sinensis, has its primary antinociceptive action through the adenosine receptor. Adenosine‐mediated analgesia has become an attractive target as it has the least side‐effects. We hypothesized that derivatives of cinnamic acid dimers, which structurally mimic INCA, show potent antinociceptive action, and their effect is mediated through adenosine receptor action. Compounds were synthesized using novel cavitand‐mediated photodimerization method, which utilizes a macromolecule (gamma‐cyclodextrin) to control the excited state reactivity of photoactive compounds to yield target tetra‐substituted cyclobutanes (dimers). The dimers generated so far show significant suppression of formalin‐induced acute pain in mice hind paw. Antinociceptive effect of ferulic acid dimer and 3‐methoxy cinnamic acid dimer was observed primarily in the inflammatory phase, and the dimer binds to the adenosine 3 receptors (as revealed by computer modeling). The pain suppressing response of these dimers was similar to that observed with indomethacin, an anti‐inflammatory drug. Even though morphine was more effective than the synthesized dimers in reducing neurogenic and inflammatory pain, there was no visible neurogenic side‐effects observed with administration of the dimers as commonly observed with morphine, which suggests a primary non‐opioid action. Our further characterization and selection of INCA analogs, with predominant adenosine receptor action, will help us to generate a new class of antinociceptives with precise chemical modifications using CMP methodology.

Support or Funding Information

UNK Undergraduate Research Fellowship (AP, MH, WM, CC); Great Plains IDeA CTR Pilot Grant (MP, SC)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Contribution of p62/SQSTM1 to PDGF‐BB‐induced myofibroblast‐like phenotypic transition in vascular smooth muscle cells lacking Smpd1 gene
Authors: Zhang Peng , Chen Jiajie , Guan Yinglu , Li Xiang , Li Pin‐Lan , Zhang Yang
Published: June 2021

Accumulating evidence indicate a critical role of acid sphingomyelinase (gene symbol Smpd1), a lysosomal hydrolase metabolizes sphingomyelin into ceramide, in controlling autophagic flux and vascular smooth muscle cell (SMC) homeostasis in atherogenesis. However, it remains elusive whether or not acid sphingomyelinase and autophagy play a modulatory role in SMC transition towards myofibroblast phenotype and extracellular matrix remodeling. In primary cultured SMCs from mouse coronary arteries, we demonstrated that PDGF‐BB stimulation produced an augmented proliferation in Smpd1−/− SMCs compared to Smpd1+/+ SMCs. More interestingly, PDGF‐BB induced more pronounced upregulation of fibroblast specific protein (FSP‐1), deposition of collagen type I, and expression of TGFβ1 in SMCs when Smpd1 is deleted. The increases in fibroblast markers in Smpd1−/− SMCs by PDGF‐BB were also accompanied by markedly elevated inflammatory status as shown by increased release of inflammatory cytokines (IL6 and IL18), expression of ICAM‐1, and monocyte adhesion. These data suggest that PDGF‐BB promotes a phenotypic transition in SMCs toward a myofibroblast‐like phenotype in the absence of acid sphingomyelinase function. Mechanistically, PDGF‐BB induced an exacerbated accumulation of autophagy substrate p62 in Smpd1−/− SMCs compared to Smpd1+/+ SMCs. In addition to impaired autophagic flux, autophagosome formation in Smpd1−/− SMCs was also suppressed by PDGF‐BB due to prolonged activation of Akt‐mTOR signaling, which further contributes to exacerbated p62 accumulation. Lastly, Akt inhibition or p62 gene silencing attenuated PDGF‐BB‐induced phenotypic changes observed in Smpd1−/− SMCs. Together, our data demonstrate, for the time, a p62‐dependent myofibroblast‐like phenotypic transition in Smpd1−/− SMCs, which indicates that acid sphingomyelinase‐regulated autophagy signaling plays a crucial role in maintaining the arterial smooth muscle homeostasis.

Support or Funding Information

National Heart, Lung, and Blood Institute grants (HL122769, HL122937) and the Young Scientists Fund of National Nature Science Foundation of China (No. 81202095).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Limonene‐induced Activation of A2A Adenosine Receptors Reduces Airway Inflammation and Reactivity in a Mouse Model of Asthma
Authors: Narke Deven , Siddiquee Armaan , Patel Mehaben , Kurade Mangesh , Mustafa S Jamal , Ledent Catherine , Ponnoth Dovenia S.
Published: June 2021

Animal models of asthma have shown that limonene (terpene in citrus fruits) reduces inflammation and airway reactivity. However, the mechanism of these effects is unknown. We hypothesized that limonene activates A2A adenosine receptors (A2AAR) to produce its effects in asthma, after comparing Glide scores for limonene (−5.19) and A2AAR agonist CGS 21680 (−8.43). We investigated the effects of limonene on lung inflammation and airway responsiveness to methacholine (MCh) as well NECA (nonselective adenosine analog) in A2AAR knock‐out (A2AKO) and wild‐type (WT) mice. Mice were divided into control (CON) and allergen sensitized‐challenged (SEN) groups, and were sensitized i.p. on days 1, 6 with 20 μg ovalbumin (OVA) followed by 5% OVA aerosol challenges on days 11–13 (n=6 mice per group). Limonene was administered as an inhalation prior to allergen challenges in one group of allergic mice for both WT and KO (SEN+LIM). Whole body plethysmography (measuring airway responsiveness as enhanced pause, Penh) and bronchoalveolar lavage (BAL) studies were performed. Airway responsiveness to MCh (48 mg/ml) in WT SEN group was significantly lowered with limonene treatment (420±92.57% in SEN vs. 56.23±25% in SEN+LIM). However, limonene did not have an effect in A2AKO (553±85% in SEN vs. 588±34% in SEN+LIM). NECA‐induced increased airway responsiveness was attenuated in limonene‐treated WT SEN mice (1002±161 in SEN vs. 250±226%, p<0.05) while no effect was observed in A2AKO groups (541±44% in SEN vs. 528±147% in SEN+LIM). Differential BAL cell analysis showed that limonene reduced levels of eosinophils in WT SEN (70.66±2.6% in SEN vs. 28.66±1.45% in SEN+LIM, p<0.05) while no difference was observed in A2AKO (76.33±1.35% in SEN vs 79±0.69% in SEN+LIM). These data suggest that limonene‐induced reduction in airway inflammation and airway reactivity occurs via activation of A2AAR.

Support or Funding Information

Long Island University start‐up funding (DSP)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Cerebral Blood Flow Responses to a Memory Test in Young and Older Habitual Exercisers
Authors: Carl Alexandra E. , Miller Kathleen B. , Howery Anna J. , Eisenmann Nicole A. , Corkery Adam T. , Barnes Jill N.
Published: June 2021

In a healthy brain, the cerebral microvessels respond to increased metabolic demand by vasodilating to increase blood flow. Reduced cerebrovascular responses to stimuli are indicative of impaired cerebrovascular functioning, and this mismatch may be a mechanism underlying age‐related reductions in cognition. The purpose of this study was to investigate how the cerebral blood flow (CBF) response to a metabolic stimulus differs between young and older participants. It has been shown that older adults have lower CBF response to chemical stimuli compared to young adults, and we hypothesized there would also be age‐associated differences in the CBF response to metabolic stimuli. We evaluated 15 young (25±1 y) and 11 older (64±1 y) habitual exercisers. Participants were instrumented with a transcranial Doppler ultrasound to measure middle cerebral artery velocity (MCAv) and a Finometer to measure beat‐to‐beat mean arterial pressure (MAP) at baseline and during two difficulty levels of the n‐back memory test. Cerebrovascular conductance index (CVCi) was calculated as MCAv/MAP. There were no group differences in BMI or resting heart rate. The older adults had a significantly higher MAP at rest compared with young adults (96±4 mmHg vs. 86±2 mmHg, respectively; p<0.05). There were no differences in MCAv at baseline. However, baseline CVCi was lower in the older adults compared with young adults (0.55±0.04 cm/s/mmHg vs. 0.70±0.06 cm/s/mmHg respectively; p<0.05). There were no differences in MCAv during either level of the test. During the level 1 test, older adults had higher MAP compared with young adults (111±6 mmHg vs. 96±3 mmHg respectively; p<0.05). During the level 2 test, the older adults again demonstrated augmented MAP compared with young adults (108±5 mmHg vs. 94±3 mmHg; p<0.05). Interestingly, older adults had a greater percent increase in CVCi compared with young adults during the level 2 test (13±3% vs. 7±2% respectively; p<0.05). Thus, while older adults had lower baseline CVCi and lower CVCi during the test, they had a greater increase in CVCi during the higher difficulty test. In summary, there were no age‐associated differences in baseline MCAv or change in MCAv during the cognitive tests, yet MAP was higher in the older adults. Therefore, our results suggest that the CBF response to an acute cognitive challenge is similar in young and older adults, but the regulatory mechanism may be different.

Support or Funding Information

Supported by National Institute of Health grant HL118154, and the American Physiological Society Undergraduate Research Excellence Fellowship.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Influence of Aging on Central Artery Stiffness and Cerebral Vascular Function Following an Acute Hypertensive Stimulus
Authors: Rosenberg Alexander Jacob , Shroeder Elizabeth C. , Grigoriadis Georgios , Wee Sang Ouk , Griffith Garett J. , Fernhall Bo , Baynard Tracy
Published: June 2021

Aging decreases cerebral blood flow and increases cerebral pulsatility. High‐intensity resistance exercise (RE) has been shown to acutely increase blood pressure (BP) and reduce cerebral blood velocity (CBv), resulting in greater flow pulsatility in the cerebral circulation, potentially injuring cerebral microvasculature. Understanding the relationship between aging and cerebral blood flow regulation in response to a hypertensive physiological stress (e.g. RE), is important due to its association with increased risk of cerebrovascular events in older adults.

Objective

To examine the effect of age on cerebral blood flow dynamics following acute RE in young and older adults.

Methods

Young (n=35, 26 yrs, BMI: 23.8 kg/m2) and older (n=26, 60 yrs, BMI: 30.1 kg/m2) adults performed maximal leg‐extension/flexion RE (3×10 rep), with hemodynamic measurements obtained pre and post‐RE (immediate, 5‐, 30‐min). CBv was measured via transcranial Doppler. Central pulse wave velocity (PWV) was acquired by an automated ambulatory BP cuff. Common carotid artery beta‐stiffness index (β) and blood flow pulsatility were measured by ultrasonography. Continuous beat‐to‐beat heart rate (HR), cardiac output (Q), blood pressure (SBP, DBP, MAP, PP) and end‐tidal CO2 were also measured.

Results

Mean and diastolic CBv increased immediately post‐RE in the young (interaction, p<0.05) and decreased below baseline at 5‐min post‐RE (p<0.05) in both groups. Older adults had a greater increase in CBv pulsatility immediate post‐RE (interaction, p<0.05) compared to the young, but continued to rise at 5‐min post‐RE only in the young (interaction, p<0.05). MAP was higher and carotid pulsatility was lower in the older group and increased immediate post‐RE (p<0.05) in both groups. PWV increased immediate post‐RE (p<0.05), and remained elevated at 5‐min post‐RE in the young (interaction, p<0.05). There were no changes in β.

Conclusions

Immediately following the cessation of the hypertensive stimulus, an increase in aortic arterial stiffness and BP occurred, accompanied by an increase in carotid and cerebral pulsatility. Despite obtaining higher BP during the stimulus in the older group, mean and diastolic CBv did not increase post‐RE, resulting in greater cerebral pulsatility in older adults. This differential age response indicates reduced cerebral hemodynamic responsiveness to an acute increase in BP with aging.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effects of fragrance inhalation of essential oil on control of blood pressure and muscle sympathetic nerve activity in humans
Authors: Kawai Eriko , Hanno Genta , Takeda Ryosuke , Ota Akemi , Morita Emiko , Imai Daiki , Suzuki Yuta , Yokoyama Hisayo , Okazaki Kazunobu
Published: June 2021

Aims

We recently reported that inhalation of fragrance of Grapefruit essential oil increased blood pressure (BP) while that of Marjoram essential oil decreased BP in humans. In this study, we investigated the effects of fragrance inhalation of Grapefruit and Marjoram essential oil on control of BP and muscle sympathetic nerve activity (MSNA), and also cardiovagal and sympathetic baroreflex function.

Methods

Thirteen healthy subjects participated in each trial of this study. The experiment was performed in the supine position. Subjects breathed blank air through a face mask for 10 min as baseline. Then, they inhaled air with the fragrance of Grapefruit or Marjoram essential oil from Douglas bags for 10 min. Throughout the trial, MSNA (peroneal nerve, microneurography), beat‐by‐beat heart rate and BP, and breath‐by‐breath respiratory variables were recorded continuously.

Results

By inhalation of the fragrance of Grapefruit essential oil, diastolic BP increased at 8 to 10 min of inhalation (64 ± 9 mmHg) compared to baseline (62 ± 9 mmHg), whereas MSNA burst rate remained unchanged at the period of inhalation (14.2 ± 8.5 bursts/min) from baseline (13.2 ± 7.0 bursts/min). Cardiovagal (10.8 ± 5.6 vs. 11.9 ± 9.6 ms/mmHg) or sympathetic baroreflex sensitivity (−0.84 ± 0.61 vs. −1.03 ± 0.78 au/mmHg) remained unchanged from baseline at the period of inhalation. On the other hand, by inhalation of the fragrance of Marjoram essential oil, diastolic BP increased at 8 to 10 min of inhalation (61 ± 7 mmHg) compared to baseline (60 ± 8 mmHg) against our previous studies, while MSNA burst rate remained unchanged at the period of inhalation (14.0 ± 8.5 bursts/min) from baseline (12.0 ± 9.4 bursts/min). Cardiovagal (12.0 ± 7.3 vs. 14.9 ± 13.1 ms/mmHg) or sympathetic baroreflex sensitivity (−1.06 ± 0.65 vs. −0.97 ± 0.54 au/mmHg) remained unchanged from baseline at the period of inhalation. Heart rate and respiratory variables remained unchanged in both trials.

Conclusions

The fragrance stimulation of Grapefruit essential oil increased BP without increase in MSNA nor modulating cardiovagal and sympathetic control of BP in humans.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Role of A1 and A2B Adenosine receptors in Angiotensin II dependent hypertension in mice.
Authors: Yadav Vishal R. , Zhou Zhichao , Teng Bunyen , Mustafa S. Jamal S.
Published: June 2021

Our recent finding showed that acute angiotensin (ANG) II stimulation enhanced A1 adenosine receptor (AR) dependent cytochrome P450 (Cyp) 4A mediated contraction in mouse mesenteric arteries (MA). In addition, A2BAR dependent and partly KATP channel mediated relaxation was reduced. These data suggest a possible interaction between ANG II and ARs at a vascular level, which may play a role in ANG II dependent hypertension (Yadav et. al. Br J Pharmacol. 2015).

We used ANG II (1000 ng/kg/min, 28 days) infused mouse model of hypertension in WT, A1 and A2B AR KO mice. Non‐invasive tail cuff method was used to measure mean arterial blood pressure (MABP). Aorta as a conduit and MA (second order) as a resistance artery were chosen for muscle tension studies. Protein expression in aortas and MAs were analyzed by western blot.

Infusion of ANG II increased MABP in mice. Particularly, in ANG II infused WT mice, MABP (mmHg, mean ± SE) at day 0 was 77.1 ± 1.7 which increased to 119.9 ± 5.6 on day 28 (p<0.05). Importantly, in A1 and A2B KO mice, increase in MABP was significantly attenuated. At day 28, in A1AR KO ANG II mice MABP was 98.5 ± 6 and in A2B KO ANG II mice was 96.3 ± 6.8.

Higher expression of A1AR (~155%) and Cyp4A (~50%) was noted in hypertensive MAs compared to control. Expression of A1AR and Cyp4A was significantly increased in WT aorta of hypertensive and control mice.

In MAs, CCPA‐induced contraction was reduced in hypertensive mice but NECA induced relaxation was comparable. Pinacidil (KATP channel opener) induced relaxation was significantly lower (−25% at 100 nM) in MAs of hypertensive mice. Importantly, in A1 and A2BAR KO mice MAs, pinacidil induced responses were comparable in control and ANG II groups. CCPA (A1AR agonist) ‐induced concentration (% PE) was reduced (~15% at 100 nM, p<0.01) in aorta of hypertensive mice compared to control. NECA, non‐selective AR agonist, produced higher (~ −15% at 10 μM, p<0.05) relaxation in aorta of hypertensive mice. Our histological analysis of aorta showed significantly reduced elastin to collagen ratio and higher media to lumen ratio suggesting vascular remodeling in ANG II hypertensive mice.

In conclusion, our data revealed important roles for A1 and A2B AR dependent signaling in ANG II induced hypertension. Reduced pinacidil induced relaxation of resistance arteries may aid vascular contraction and blood pressure. Further studies involving pharmacological inhibitors and genetic models (ANGII KOs) are required to understand the interaction between ANG II and ARs at vascular level in the development of hypertension.

Support or Funding Information

Supported from NIH grant HL 027339.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Chronic High Salt Intake Reduces Protein Expression of Tumor Necrosis Factor‐alpha Receptor Type 1 in Renal Cortical Tissue of Mice Lacking the Gene for Endothelial Nitric Oxide Synthase
Authors: Majid Dewan Syed Abdul , Prieto Minolfa C. , Chamberlain Cameron M. , Castillo Alexander
Published: June 2021

As tumor necrosis factor‐alpha (TNF‐α) induces natriuresis via activation of its receptor type 1 (TNFR1), its mechanistic role in the development of salt sensitive hypertension (SSH) is not yet clearly defined. We have shown earlier that chronic high salt (HS) intake increase, but non‐specific pharmacological inhibition of nitric oxide synthase (NOS) isoforms decreases TNFR1 protein expression in the kidney. Here we examined the hypothesis that such decrease in TNFR1 protein expressions are specific to inhibition of the endothelial isoform of NOS (eNOS), which is the main isoform linked to the development of SSH. Experiments were performed in mice lacking the gene for eNOS (eNOSKO) as well as in wildtype (C57BL6) mice (n=6–7 in each group; 8–9 weeks of age) chronically fed either normal (NS; 0.4% NaCl) or HS (4% NaCl) containing diet for 3 weeks. Systemic BP had measured using tail‐cuff plethysmography and urine collections for 24 hours had performed using metabolic cages at the start of the experiment and at the end of every week during the experimental period. After sacrificing the mice at the end of the treatment period, the kidneys were isolated and processed for tissue analysis. Immunohistochemical analysis of TNFR1 and TNFR2 protein expressions in renal cortical tissues had performed using appropriate antibodies. The staining as well as intensity of TNFR1 and TNFR2 immunoreactivity in renal cortical sections had analyzed using NIS Elements Software AR, which allowed a computerized determination of the area of positive staining and the intensity of immunoreactivity. In the basal condition, the mean BP in eNOSKO mice was higher (89± 0.8 vs 76 ±2.1 mmHg) than that in WT mice. There is no change in BP after 3 wks of NS or HS intake in WT, but HS intake for similar period in eNOSKO increased BP (107±3.6 vs 88 + 0.9 mmHg) compared to the baseline value. As expressed in percent area of positive staining, it was observed that TNFR1 immunoreactivity is lower in eNOSKO mice compared to WT mice both in NS (1.4± 0.2% vs 2.7± 0.6%; P<0.05) and HS (1.8± 0.2% vs 4.1 ± 0.5%; P<0.01) intake conditions. The intensity of TNFR1 immunoreactivity also showed the similar results. However, TNFR2 immunoreactivity was minimal in both strains of mice. Collectively, these data indicate that TNFR1 activity is downregulated in the kidney in the condition of eNOS deficiency that minimizes sodium excretion during HS intake leading to the development of SSH induced by oxidative stress conditions.

Support or Funding Information

COBRE‐ P30GM103337 & Tulane Bridge Fund

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Nitric Oxide and Sympatholysis in Rat Soleus Feed Arteries
Authors: Whitaker Madelyn , Heckle Tanner , Jasperse Jeffrey
Published: June 2021

Previous evidence indicates that nitric oxide (NO), acidity, and ATP may all mediate functional sympatholysis. First, we hypothesized that in rat soleus muscle feed arteries, sympatholytic NO is released from vascular endothelial cells by increased shear stress and acts through a guanylyl cyclase intracellular signaling pathway. Second, we hypothesized that NO, acidity and ATP would inhibit sympathetic signaling in a cumulative fashion. Soleus feed arteries (n = 12 per group) were isolated from male Sprague‐Dawley rats and cannulated on two glass micropipettes for in vitro videomicroscopy. We measured the constriction response to the adrenergic agonist phenylephrine (PE; 10−9 M to 10−4 M, 0.5 log increments) in the presence of varying levels of the nitric oxide donor sodium nitroprusside (SNP; 0 nM, 100 nM and 100 mM), shear stress (0 dy/cm2, 25 dy/cm2, and 135 dy/cm2), SNP + ODQ (30 mM), an inhibitor of guanylyl cyclase, and ATP (1 mM and 100 mM) and decreased pH (7.1 and 6.5). SNP reduced constriction to PE in a dose‐dependent manner (maximum constriction 77.3 % vs. 70.7 % and 56.7 %), indicating that NO interferes with sympathetic constriction. ODQ restored PE‐induced constriction (PE alone 77.5%; with SNP 67.6%; with SNP + ODQ 83.5%), indicating that NO causes sympatholysis through a guanylyl cyclase signaling pathway. However, shear stress did not reduce constriction to PE (67.6 % vs. 68.1 %, and 67.6 %), indicating that increased shear stress during exercise is not the source of the NO causing sympatholysis. Finally, SNP alone reduced constriction to PE (maximum constriction 77.3% vs. 70.7% and 56.7%) as much as SNP + low pH (83.5% vs. 71.4% and 59.1%) or SNP + ATP + low pH (75.7% vs. 70.1% and 61.6%), indicating that these sympatholytic agents do not have a cumulative sympatholytic effect. We conclude that nitric oxide acting through guanylyl cyclase causes sympatholysis, but the source of the nitric oxide during exercise is not shear stress‐induced endothelial cell activation.

Support or Funding Information

Dee Anna Smith Fund for Women in STEM and the Seaver Research Council of Pepperdine University.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
GsMTx4 Reduces the Pressor Response during Dynamic Hindlimb Muscle Stretch in Decerebrate Rats
Authors: Sanderson Bailey C. , Rollins Korynne S. , Kempf Evan A. , Hopkins Tyler D. , Butenas Alec L. , Ade Carl J. , Copp Steven W.
Published: June 2021

The exercise pressor reflex, which is activated by mechanical and metabolic stimuli arising from within contracting skeletal muscles, contributes to the increase in blood pressure that occurs during exercise. GsMTx4, a mechano‐gated channel inhibitor that is partially selective for piezo channels, was recently found to reduce the pressor response during static rat hindlimb muscle stretch, a maneuver that is commonly used to study the mechanical component of the exercise pressor reflex. However, the GsMTx4‐induced reduction of the pressor response was limited to the initial phase (i.e., the first ~5 sec) of the stretch when muscle length was changing. That finding may reflect the rapid deactivation kinetics of piezo2 channels and the possibility that they do not contribute importantly to the later phases of a static stretch when muscle length is not changing. To investigate this possibility, we tested the hypothesis that in decerebrate, unanesthetized rats, GsMTx4 would reduce the pressor response throughout the duration of a 1 Hz dynamic hindlimb muscle stretch protocol that produced repeated changes in muscle length. Young adult male Sprague‐Dawley rats (n=12) had a jugular vein and both common carotid arteries cannulated. The left calcaneus was cut and the triceps surae muscles were linked by string to a force transducer. The pressor response during 30 seconds of 1 Hz dynamic stretch was measured before and after the injection of 10 μg of GsMTx4 into the arterial supply of the left hindlimb. We found that GsMTx4 reduced the peak pressor response during dynamic stretch (control: 15±4, GsMTx4: 5±2 mmHg, p=0.047, n=7). Moreover, the effect of GsMTx4 on the pressor response was evident throughout the duration of the dynamic stretch protocol. GsMTx4 did not, however, reduce the pressor response that resulted from the hindlimb arterial injection of 24 mmol lactic acid (control: 32±5, post‐GsMTx4: 29±4 mmHg, p=0.53) which indicates that GsMTx4 did not block voltage‐gated sodium channels in our experiments. Furthermore, the injection of GsMTx4 into the jugular vein (n=5) had no effect on the pressor response during dynamic stretch (control: 19±6, GsMTx4: 19±4, p=0.98). This finding indicates that when GsMTx4 was injected into the arterial supply of the hindlimb its effect on the pressor response during stretch was due to its actions on the peripheral endings of the sensory neurons. Our present findings suggest that piezo channels, most likely piezo2 channels, contribute to the pressor response throughout the duration of dynamic hindlimb muscle stretch in decerebrate rats.

Support or Funding Information

Supported by university/departmental funds

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Duration Dependent Effects of Intermittent Hypoxia (IH) on Adult Hippocampal Neurogenesis
Authors: Nallamothu Thara , Khuu Maggie A. , Garcia Alfredo J.
Published: June 2021

Patients with sleep apnea commonly exhibit cognitive decline and injury to the hippocampal formation. Rodents exposed to IH, a primary consequence of the condition, also show impaired hippocampal based learning and memory. While these impairments correlate with suppressed long‐term potentiation, synaptic plasticity is only one process that supports normal function in this brain structure. Adult neurogenesis is also important for maintaining normal hippocampal physiology. Although Hypoxia Inducible Factor 1a (HIF1a) signaling is to important cellular development and homeostatic responses to hypoxia, chronic IH‐dependent HIF1a activity can promote pathophysiology. In this ongoing study, we test the hypothesis that IH causes HIF1a dependent signaling in neural stem cells (NSCs) to disrupt the adult neurogenesis. To follow the fate of wildtype NSCs and NSCs heterozygous for HIF1a (HIF1a+/−), we used a birth labeling strategy in transgenic mice. After labeling NSCs, we exposed mice to 0 (control), 10, or 30 days of IH. Tissue was harvested for immunohistochemical study at the 33 to 35 day time point. Relative to control, 10 days of IH increased the proportion of GCs generated from wildtype NSCs (by 23% ± 1% SEM, n=3); whereas, 30 days IH suppressed this proportion (−9% ± 2% SEM, n=2). Sholl analysis showed dendritic complexity was similar across all wildtype GCs. 30 days IH exaggerated the loss of GCs generated from HIF1a+/− NSCs (by −30% ± 5%, n=3). These findings indicate that IH has duration‐dependent effects on adult neurogenesis that impact the terminal differentiation of NSCs to GCs and involves IH‐dependent HIF1a signaling in NSCs. These findings suggest that IH‐dependent HIF1a signaling has both positive and negative effects on adult neurogenesis. This mechanism could be a contributor to the negative effects on learning and memory commonly seen in sleep apnea patients.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Progesterone induced blocking factor improves fetal growth restriction possibly by reducing inflammation and placental cytolytic NK cells in response to placental ischemia during pregnancy
Authors: Amaral Lorena M. , Cottrell Jesse N. , Cornelius Denise C. , Cunningham Mark W. , Ibrahim Tarek , LaMarca Babbette
Published: June 2021

Preeclampsia (PE), new onset hypertension, is a progesterone deficient state and is associated with an imbalance among CD4+ T lymphocytes, natural killer (NK) cells, and inflammatory cytokines which are likely culprits for decreased fetal weight during PE pregnancies. During normal pregnancy activated lymphocytes express progesterone receptors, which enable progesterone to induce a protein called progesterone induced blocking factor (PIBF). PIBF increases during normal pregnancy and has been shown to decrease inflammation and cytolytic NK cells, both of which are increased during PE. Currently, there is no effective treatment for PE except for early delivery, making PE the leading cause for premature births worldwide. We have previously shown that progesterone supplementation with 17‐OHPC improves inflammation, fetal weight and blood pressure in the preclinical RUPP rat model of PE. However the mechanism where by progesterone improves the pathophysiology of PE has never been determined. This study was designed to test the hypothesis that PIBF reduces inflammation while improving hypertension in response to placental ischemia. To test this hypothesis, PIBF (2.0 μg/mL) was administered intraperitoneally on gestation day 15 to RUPP or normal pregnant (NP) rats and on day 18 carotid catheters were inserted and on GD 19 blood pressure and samples were collected. MAP in NP rats (n=9) was 102± 3 and 110 ± 3 in NP+PIBF (n=5), 124± 3 in RUPP rats (n=4), which improved to 110±3 mmHg in RUPP+PIBF (n=8), p<0.05. Pup weight was 2.4± 0.1 g in NP, 2.5± 0.1 in NP+PIBF, 1.9±0.1 in RUPP and improved to 2.2±0.1 in RUPP+PIBF, p<0.05. Total placental NK cells were 31± 9 in NP (n=4), 31±5 in NP+PIBF (n=4), 42 ±8 in RUPP rats (n=4) and reduced to 26± 2 in RUPP+PIBF (n=6). Placental cytolytic NK cells were 0.8±0.1 in NP, 0.2±0.1 in NP+PIBF, and 1.4±0.1 in RUPP rats, which decreased to 0.4+0.1 in RUPP+PIBF, p<0.05. CD4+ T cells were decreased from 21±6 in RUPP rats (n=4) to 8±2 gate in RUPP+PIBF (n=7). Collectively, our findings demonstrate that PIBF, a produce to progesterone receptor stimulation by progesterone, could be a mechanism to improve fetal growth restriction, inflammation as indicated by CD4+ T cells and cytolytic NK cells while normalizing blood pressure in response to placental ischemia during pregnancy.

Support or Funding Information

Supported by NIH grants RO1HD067541, HL130456 and AMAG Pharmaceuticals

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.