bluuebunny/crossref_metadata_2025 huggingface dataset:
Central Ang 1‐7 Modulates Lipolysis and Thermogenesis in Adipose Tissue.
Authors: Evangelista Fabiana , Bartness Timothy
Published: June 2021

Angiotensin 1‐7 (Ang 1‐7) attenuates metabolic dysfunction and increases sympathetic drive. We investigated the effect of third ventricular (3V) injection of Ang 1‐7 on lipolytic and thermogenic activities of adipose tissue (AT). Siberian hamsters (Experiment 1, n=18) had 3V cannulae implanted, interscapular brown AT (IBAT) temperature transponders and an intraperitoneal temperature probe. Each animal received 3V injections (200 nl) with 48h intervals: saline (S), 0.3 nmol Ang 1‐7, 3 nmol A‐779 (Mas receptor antagonist) and 0.3 nmol Ang 1‐7 + 3 nmol A‐779. IBAT temperature increased after Ang 1‐7 at 10 and 20 min, decreased after A‐779 at 60 min, and was higher after Ang 1‐7 than Ang 1‐7 + A‐779 at 20, 30 and 60 min. A‐779 and Ang 1‐7 + A‐779 decreased core temperature at 60 min compared with 10 min (p蠄0.05). In the Experiment 2, the animals (n=36) were killed 10 min later after a single injection. Blood Ang 1‐7 and glucose did not change, but Ang 1‐7 injection increased free fatty acids compared with S and A‐779, and serum glycerol compared with S (p蠄0.05). Ang 1‐7 increased p‐HSL expression compared with A‐779 (IBAT), increased p‐HSL/HSL ratio compared with other injections (IBAT) and with S in retroperitoneal white AT (RWAT; p蠄0.05), but did not change in epididymal and inguinal AT (EWAT and IWAT). ATGL was not changed in IBAT, RWAT or EWAT, but was reduced after Ang 1‐7 and A‐779 injections compared with S in IWAT (p蠄0.05). UCP‐1 protein expression did not change in IBAT. In conclusion, central Ang 1‐7 increased IBAT thermogenesis and increased cellular markers of lipolysis in IBAT and RWAT in a Mas receptor‐dependent manner, according to p‐HSL/HSL ratio. Supported by FAPESP (13/03083‐4) to FSE and NIH R37 DK35254 to TJB.
Stress tolerance in the green crab, Carcinus maenas exposed to waste water treatment plant effluent
Authors: Pelletier Gwendolyn , Goodchild Christopher , Whalen Claire , Frederich Markus
Published: June 2021

Wastewater treatment plant effluent (WTPE) is commonly discharged into marine environments. We investigated the effect of WTPE on the stress tolerance of the green crab Carcinus maenas. Crabs were placed in 5 and 20% of WTPE and incubated for 4 days and then underwent an anoxia challenge for 1 hour. 20% WTPE‐exposed crabs showed decreased treadmill running endurance (145±76 and 316±179 sec, respectively), righting response (8.9±8.4 and 3.5±5.7 sec), and oxygen consumption (0.067±0.012 and 0.064±0.009 µmol/g/min). Glutathione‐S‐transferase (GST) activity, as an indicator for oxidative stress, was increased in WTPE exposed crabs (0.9±0.46, 3.3±0.52 and 2.25±1.84 units/mg protein for control, 5% and 20%, respectively). Gene expression assessed by qPCR revealed only a 1.5 fold increase in AMP‐activated protein kinase (AMPK), as an indicator of cellular energy stress, and a 1.3 fold increase in HSP70, as a general stress marker, for the 20% WTPE treated animals. Overall, there was very little change in the selected stress parameters after exposure to WTPE, paired with anoxia. This is different than observed in a parallel study using the blue mussel, Mytilus edulis, which showed diminished performance at the whole animal and cellular level after exposure to WTPE. Our data indicate that WTPE does not diminish the performance of the green crab, but that of other species. Therefore, WTPE might aid in the success of the invasive green crab in dominating new environments. Further studies will continue to explore this.

Supported by an APS summer fellowship to G.P. and a Maine SeaGrant Project Development grant to M.F.
Chronic Sweetener Intake and its Effects on IGF‐II and IGF‐IIR Expression in the Mouse Brain.
Authors: Morales Esmeralda , Contreras Irazú , Estrada José
Published: June 2021

Chronic excessive intake of refined sugars contributes to the incidence of pathologies such as type 2 diabetes, metabolic syndrome and cardiovascular disease. Sweeteners are an alternative used to replace sugar in food. Although they are considered innocuous, recent studies have shown they may have unwanted effects in humans. The objective of this study is to determine the expression of the growth factor IGF‐II and its receptor in the central nervous system of mice supplemented with sweeteners for prolonged periods of time. Four groups of 8 week‐old mice were used: A control group (without supplementation), and three groups supplemented with either sucrose, stevia or sucralose in their drinking water. The animals were supplemented for 6 weeks. After supplementation, the brain and spinal cord were dissected and their proteins purified to determine the expression of IGF‐II or IGF‐IIR by western blot. Our results show decreased expression of IGF‐II only on brain tissue from male individuals in the stevia‐supplemented group, compared to all other groups, whereas the expression of IGF‐IIR decreased for both males and females also in the stevia group, but not in the other groups. Our results suggest that chronic intake of stevia may alter the expression of IGF‐II and IGF‐IIR in cells from the central nervous system, which may have detrimental effects on essential physiologic mechanisms in nervous tissue.
Functional Identification of Cortical and Subcortical Areas Associated with the Increase in Muscle Sympathetic Nerve Activity in Obstructive Sleep Apnoea
Authors: Macefield Vaughan , Fatouleh Rania , Lundblad Linda , McKenzie David , Macey Paul , Henderson Luke
Published: June 2021

Muscle sympathetic nerve activity (MSNA) is greatly elevated in patients with obstructive sleep apnoea (OSA) during daytime wakefulness, leading to hypertension. By recording MSNA concurrently with functional Magnetic Resonance Imaging (fMRI) we aimed to identify the central processes responsible for the sympathoexcitation. Spontaneous fluctuations in MSNA were recorded via tungsten microelectrodes inserted into the peroneal nerve in 17 OSA patients and 15 age‐matched controls while lying in a 3T MRI scanner. Blood Oxygen Level Dependent (BOLD) contrast gradient echo, echo‐planar images were continuously collected in a 4 s ON, 4 s OFF protocol. Fluctuations in BOLD signal intensity covaried with the intensity of the concurrently recorded bursts of MSNA. Signal intensity in the dorsolateral PFC, medial PFC, dorsal precuneus, anterior cingulate cortex, retrosplenial cortex and caudate nucleus was higher in OSA than in controls, while in the RVLM, dorsolateral pons and medullary raphe it was lower. All of these changes were reversed following 6 months of continuous positive airway pressure, which caused a significant fall in MSNA. We conclude that the elevated MSNA in OSA results from functional changes within suprabulbar regions known to be directly or indirectly involved in the modulation of sympathetic outflow via the brainstem, as well as from functional changes within the brainstem itself.
Sympathoexcitation by Inhibition of SK Channel Activity in the Hypothalamic PVN is Attenuated by Local AT1 Receptor Blockade
Authors: Huber Michael , Gui Le , Chapp Andrew , Gu Mingjun , Zhu Jianhua , Shan Zhiying , Chen Qing‐Hui
Published: June 2021

Small conductance Ca2+ activated K+ (SK) channels act as negative feedback regulators of neuronal excitability. We have reported that SK channels expressed in the paraventricular nucleus (PVN) are involved in controlling neuronal activity, sympathetic nerve activity (SNA) and arterial pressure (AP). Blockade of SK channels in the pre‐sympathetic PVN neurons increases neuronal excitability, SNA and AP. Here we investigated the effect of angiotensin II type 1 receptor (AT1R) blockade on the sympathoexcitatory and presser responses elicited by the inhibition of SK channels in the PVN. In anesthetized rats, PVN microinjection of SK channel blocker with apamin (12.5 pmol, 50nl) (n=7) increased splanchnic SNA (SSNA) (278 ± 50%), renal SNA (RSNA) (193 ± 12%), and mean AP (MAP) (32 ± 4mmHg). Pre‐treatment with PVN injection of losartan (20 nmol), an AT1R antagonist, significantly attenuated (n=6) the elevated SSNA (129 ± 37%; p<.05 vs vehicle control), RSNA (84 ± 40%; p<.05 vs vehicle control), and MAP (10 ± 6mmHg; p<.05 vs vehicle control) after PVN injection of apamin. Pre‐treatment with PVN injection of ZD7155 (1.0 nmol), another AT1R antagonist, significantly attenuated (n=5) the elevated SSNA (112 ± 30%; p<.05 vs vehicle control), RSNA (81 ± 23%; p<.05 vs vehicle control) and MAP (7 ± 2mmHg; p<.05 vs vehicle control) elicited by PVN apamin. No significant difference was found between pretreatment with losartan and ZD7155 for SNA and MAP. Our data indicate that sympathoexcitation and pressor responses induced by inhibition of SK channel activity involve the activation of AT1R in the PVN. Support: AHA7420029 (ZYS) 2640130 (QHC).
Trimethylation of Histone 3 Lysine 4 on Hypothalamic (Pro)renin Receptor Mediates the Development of DOCA‐salt Hypertension.
Authors: Li Wencheng , Sullivan Michelle , Feng Yumei
Published: June 2021

We reported that brain (pro)renin receptor (PRR) expression is elevated in deoxycorticosterone acetate (DOCA)‐salt hypertension; however, the underlining mechanism remains unknown. To test our hypothesis that epigenetic mechanism is involved in the regulation of PRR expression in DOCA‐salt hypertension, C57Bl/6J mice were implanted with SHAM or DOCA pellet and supplied with saline for 3 weeks. Histone modifications on PRR promoter were assessed in the hypothalamus using Chromatin Immunoprecipitation assays at the end of protocol. We found an increase (fold change) in histone 3 lysine 4 trimethylation (H3K4me3) on the PRR promoter in DOCA‐salt (2.45±0.36) compared with SHAM treated mice (1.00±0.16, P<0.05), which was not altered by ICV infusion of losartan (2.33±0.27). Importantly, we found increased H3K4 methyltransferases (HMT) activity (OD/hour/mg protein), an enzyme complex responsible for H3K4 methylation, after DOCA‐salt treatment (44.54±2.09, P<0.05) compared with SHAM (28.23±2.05). To examine the contribution of H3K4me3 on PRR expression and the increased BP during DOCA‐salt hypertension, mice were treated with DOCA‐salt and ICV infused with either artificial CSF or 5'‐methylthioadenosine (MTA), a specific methyltransferase inhibitor, for 3 weeks. ICV infusion of MTA normalized the increase in H3K4me3 (0.9±0.11), HMT activity (32.3±2.38) compared with ICV aCSF in DOCA‐salt treated mice. ICV infusion of MTA attenuated PRR mRNA levels (1.4±0.1 vs. 2.4±0.2) and BP (123.1±6.3 vs. 138.5±7.4 mmHg) compared with control following DOCA‐salt treatment. In summary, H3K4me3 on PRR promoter is a key epigenetic mechanism for the up‐regulation of brain PRR and the increase in BP during salt‐sensitive hypertension.
Role of A1 and A2 Noradrenergic Neurons and Median Preoptic Nucleus in Cardiovascular Recovery Induced by Hypertonic Saline Infusion in Hypovolemic Hemorrhagic Rats
Authors: Amaral Nathalia , Naves Lara , Xavier Carlos , Pedrino Gustavo
Published: June 2021

Previous studies showed the involvement of Median Preoptic Nucleus (MnPO) and medullary catecholaminergic neurons (A1 and A2) in cardiovascular responses to changes in plasma osmolality. The present study examines the role of A1 and A2 noradrenergic neurons and MnPO in cardiovascular recovery induced by hypertonic saline infusion (HSI) in hypovolemic hemorrhagic rats. All experiments were performed in Wistar rats. Lesions of A1 and A2 neurons were obtain by nanoinjections of anti‐DBH‐saporin (6.3 ng/60nl). In other group nanoinjections muscimol (GABA agonist ‐ 4 mM) were used to blockade MnPO. Bleeding was induced by the withdrawal of blood for over 10 min until MAP reaches approximately 60 mmHg. After 20 min of hemorrhagic period, HSI administration was performed (3M NaCl; 1.8 ml/kg; i.v). On the day of experiment, rats were anesthetized with thiopental (40 mg/kg, i.v.) and instrumented for mean arterial pressure (MAP) recording. In sham‐rats we observed a recovery of MAP (112 ± 4.6 mmHg, 10 min after HSI). The blockade of MnPO prevented restoration of MAP induced by HSI (60 ± 6.2, 10 min after HSI; p <0.05). Similar to observed in sham rats, HSI induced a recovery of MAP in A1 (101 ± 8.5 mmHg; 10 min after HSI) and A2 lesioned rats (121.4 ± 5.3 mmHg, 10 min after HSI). In A2 pressor response was greatest. The MnPO injections sites and A1 or A2 lesions extensions were confirmed by histology analysis. These results showed that the MnPO plays an important role in HSI induced resuscitation in hemorrhagic shock. However, A1 and A2 noradrenergic neurons seem not to be directly involved in the cardiovascular recovery induced by HSI in hemorrhagic rats.

Financial Support: CNPq, FAPEG
Angiotensin II Upregulates CAPON Expression via ERK‐MAPK‐CREB Pathway in the Paraventricular Nucleus of Rats with Chronic Heart Failure
Authors: Sharma Neeru , Zheng Hong , Liu Xuefei , Patel Kaushik
Published: June 2021

Elevated levels of angiotensin II (Ang II) and its receptor (AT1) in brain are responsible for increase sympatho‐excitation during heart failure (HF).Previously, we have demonstrated that higher levels of CAPON (nitric oxide synthase 1‐adaptor protein) down regulate neuronal nitric oxide synthase (nNOS) in the paraventricular nucleus (PVN) of rats with HF. The significant increase in CAPON transcript (15 folds) in the PVN of HF rats was ameliorated by Losartan treatment (10 mg/kg/day for three weeks), suggesting the involvement of AngII/AT1R signaling in transcriptional up‐regulation of CAPON. In vitro studies using NG108 cells showed that Ang II dependent increases in CAPON expression was abrogated in presence of the mitogen‐activated protein kinase/ERK kinase 1/2 inhibitor U0126. The in silico analysis of the ~7.5 kb upstream DNA sequences from the translational start site of CAPON genes identified two likely promoter elements (Promoter 2.0 Prediction Server) containing the sequences responsive (TES Software) to transcriptional factor CREB binding. Concurrently, there was activation of ERK and CREB transcriptional factors in the PVN of rats with HF as evident by increased ERK‐P/ERK (1.43±0.1 Sham. vs. 1.98±0.1 HF) and CREB‐P/CREB (1.07±0.03 Sham. vs. 1.56±0.05 HF) ratios. The siRNA‐mediated silencing of ERK and CREB in NG108 cells ameliorate Ang II mediated upregulation of CAPON further supporting the involvement of MAP kinase in facilitating CAPON up‐regulation. Taken together, our results demonstrate the involvement of the ERK1/2 pathway in selective up‐regulation of CAPON expression, possibly via activation of CREB.
Overexpression of Copper/Zinc Superoxide Dismutase (SOD1) in the Organum Vasculosum of the Lamina Terminalis (OVLT) Attenuates Chronic Angiotensin II (AngII) Hypertension in the Rat
Authors: Collister John , Taylor‐Smith Heather , Drebes Donna , Nahey David , Tian Jun , Zimmerman Matthew
Published: June 2021

Circulating angiotensin II (AngII) is sensed at brain circumventricular organs such as the subfornical organ (SFO) and organum vasculosum of the lamina terminalis (OVLT) to cause changes in sympathetic nervous system output accordingly. Previous lesion studies of either the SFO or the OVLT have shown a diminution of the hypertensive effects of chronic AngII, without providing a clear explanation as to the intracellular signaling pathway(s) involved. Additional studies have reported that overexpressing SOD1, an intracellular superoxide (O2•‐) scavenging antioxidant enzyme, in the SFO attenuates chronic AngII‐induced hypertension. Herein, we tested the hypothesis that overproduction of O2•‐ in the OVLT is also an underlying mechanism in the long‐term hypertensive effects of chronic AngII. Adenoviral vectors encoding human SOD1 (AdSOD1) or control vector (AdEmpty) were injected directly into the OVLT of rats implanted with aortic telemetric transmitters for recording of arterial pressure. After a 3 day control period of saline infusion, rats were intravenously infused with AngII (10 ng/kg/min) for ten days. Rats overexpressing SOD1 (n=5) in the OVLT had a blood pressure increase of only 12+8 mmHg after 10 days of AngII infusion while blood pressure rose 36+9 mmHg in AdEmpty‐infected rats (n=3). These results support the hypothesis that production of O2•‐in the OVLT contributes to the development of chronic AngII‐dependent hypertension.
Glucose Concentrations Influence Subfornical Organ Neuron Responsiveness to Cholecystokinin
Authors: Cancelliere Nicole , Dai Li , Ferguson Alastair
Published: June 2021

Cholecystokinin (CCK) is a peptide hormone released into the bloodstream by the small intestine in response to meal consumption. Although much is known about CCK's role in digestion, its effect on the central nervous system and role as a hunger suppressant are less well understood. Our lab has previously shown that circulating CCK is sensed by the subfornical organ (SFO), a circumventricular organ lacking a blood‐brain barrier, and may influence central autonomic control via activation of CCK2 receptors (Ahmed et al., 2014). The purpose of this study was to determine the effects of glucose concentration on the excitability of SFO neurons in response to CCK. SFO neurons from Sprague Dawley rats (125‐200g) were micro dissected, dissociated, and incubated at three different glucose concentrations (1mM, 5mM, and 10mM). Then, using whole‐cell and perforated patch current clamp recording techniques, the effects of bath application of CCK (10nM and 0.1nM) on membrane potential at these glucose concentrations (1mM, 5mM, and 10mM) were assessed. We found that at 1mM glucose, the majority of responding cells hyperpolarized (39% hyperpolarized [mean membrane potential (MMP): ‐14.8 ± 2.1 mV], n=13; vs. 18% depolarized [MMP: 6.4 ± 1.9 mV], n=6) in response to 0.1 nM CCK. In contrast at 5mM and 10mM glucose, CCK depolarized the majority of responding cells (53% and 40% depolarized [MMP: 10.3 ± 1.0 mV and 12.1 ± 2.7 mV], n=10 and n=10; vs. 21% and 24% hyperpolarized [MMP: ‐14.7 ± 3.9 mV and ‐11.6 ± 2.8 mV], n= 4 and n=6). This study suggests that circulating levels of glucose may affect central autonomic integration in the subfornical organ.

Supported by the Canadian Institutes of Health Research
Dipeptidyl‐peptidase IV mRNA Expression with Exercise and Amino Acid Supplementation
Authors: Neidert Leslie , Mobley Christopher , Roberts Michael , Kluess Heidi
Published: June 2021

Dipeptidyl‐peptidase IV (DPP‐IV) is an enzyme circulating in the plasma, but the sources of plasma DPP‐IV are unknown. Plasma DPP‐IV is higher in individuals with high lean mass. Research showed that DPP‐IV is released from skeletal muscle as a myokine, making muscle a possible source of plasma DPP‐IV, but the stimulus for release is unknown. We hypothesized that acute exercise and amino acid or protein feeding would increase skeletal muscle DPP‐IV mRNA, and that the combination would have a synergistic effect. Male Wistar rats (~250 g) were fed 0.054 g leucine (LEU), 0.50 g whey (WP), or water (PLA) following 4 sets of 8 electrically‐stimulated unilateral plantarflexor contractions (EX). Contralateral un‐stimulated legs were used as a control condition (CTL). Gastrocnemius muscles were harvested 3 and 6 h post‐stimulation, real time PCR was performed to determine the change in DPP‐IV mRNA expression, and all data was normalized to PLA‐CTL muscles as fold‐change values. Relative to PLA‐CTL: a) PLA‐EX increased DPP‐IV mRNA 1.3‐fold at 3 h (p = 0.03); b) LEU‐CTL increased DPP‐IV mRNA 2.4‐fold at 3 h (p = 0.01), but declined to 1.3‐fold at 6 h (p = 0.27); c) LEU‐EX increased DPP‐IV mRNA 1.3‐fold at 3 h (p = 0.18), but fell below PLA‐CTL by 6 h (p = 0.12); d) WP‐CTL increased DPP‐IV mRNA 3.6‐fold by 3 h (p = 0.01) and remained 3.1‐fold elevated at 6 h (p = 0.001) ; and e) WP+EX increased DPP‐IV mRNA 1.9‐fold at 3 h (p =0.01) and remained elevated 3.1‐fold at 6 h (p = 0.01). DPP‐IV mRNA expression increased following muscle contraction and LEU and WP feeding, although WP appears to potently stimulate DPP‐IV mRNA expression regardless of muscle contraction. Future research should address if chronic WP supplementation chronically elevates DPP‐IV secretion from skeletal muscle.
Heat shock protein‐70‐mediated mild heat preconditioning attenuates heat injury in cardiomyocytes by inhibiting Cathepsin B pathway
Authors: Lin Cheng‐Hsien , Hsu Shu‐Fen
Published: June 2021

In H9c2 cardiomyocytes, preinduction of heat shock protein (HSP) 70 significantly attenuates heat induced myocardial apoptosis. However, the underlying mechanisms of the beneficial effects of HSP70 pre‐induction in preventing myocardium apoptosis remain unclear. Herein, we investigated whether Cathepsin B is involved in cardiomyocyte apoptosis caused by hyperthermic injury (HI) and HSP70 protects these cells from HI‐induced apoptosis mediated by Cathepsin B. HI was produced in H9C2 cells by putting them in a circulating 43 °C water bath for 120 min, whereas preinduction of HSP70 was produced in H9C2 cells by mild heat preconditioning 8 h before the start of HI. It was found that HI caused both cardiomyocyte apoptosis and increased Cathepsin B activity in H9C2 cells. E‐64‐c (Cathepsin B inhibitor) significantly reduced HI induced H9c2 apoptosis. Preinduction of HSP70 by mild heat preconditioning or inhibition of HSP70 by Triptolide also significantly attenuated or exacerbated respectively both the apoptosis and increased Cathepsin B activity in H9C2 cells. Furthermore, the beneficial effect of preinduction of HSP70 by mild heat preconditioning in reducing both cell apoptosis and increased Cathepsin B activity caused by HI can be significantly reduced by Triptolide preconditioning. These results indicate that Cathepsin B is involved in HI induced cardiomyocyte apoptosis in H9C2 cells and HSP70 protects these cells from HI induced cardiomyocyte apoptosis through Cathepsin B pathways.
Oxidative stress impairs NO‐dependent cutaneous vasodilation but not NO‐dependent sweating in young adults during high intensity exercise
Authors: Meade Robert , Fujii Naoto , McGinn Ryan , Paull Gabrielle , Akbari Pegah , Kenny Glen
Published: June 2021

Our recent work showed that nitric oxide (NO)‐dependent sweating and cutaneous vasodilation are diminished in young males during intermittent exercise at high (700 W) relative to moderate (400 W) rates of metabolic heat production. We tested the hypothesis that this impairment results from increased oxidative stress during high intensity exercise. On separate days, nine young (24 ± 2 years) healthy males performed two 30 min bouts of semi‐recumbent cycling in the heat (35°C, 20% RH) at a rate of metabolic heat production of i) 500 W or ii) 700 W. The first and second exercise bouts were followed by 20 and 40 min of recovery, respectively. Forearm local sweat rate (LSR) and cutaneous vascular conductance (CVC) were measured at 4 skin sites that were continuously perfused via intradermal microdialysis with: 1) lactated Ringer's solution (Control), 2) 10 mM ascorbate (ASC, antioxidant), 3) 10 mM L‐NG‐Nitroarginine methyl ester (L‐NAME, non‐selective NO synthase inhibitor), or 4) 10 mM ASC + 10 mM L‐NAME. During moderate intensity exercise (i.e., 500 W), L‐NAME and ASC + L‐NAME reduced LSR and CVC compared to the Control site (all P < 0.05), while no effect of ASC was observed (all P > 0.05). Conversely, high intensity exercise performed at 700 W did not result in differences in LSR between treatment sites (P = 0.85). However, compared to Control, CVC was elevated at the ASC (all P < 0.05) while it was reduced at the L‐NAME (all P < 0.05) and ASC + L‐NAME (all P < 0.05) sites. Altogether these results suggest that oxidative stress impairs NO‐dependent cutaneous vasodilation but not LSR during intense exercise. Support: Natural Sciences and Engineering Research Council of Canada.
Roles of Brown Adipose Tissue in Seasonal Variations of Thermogenesis in Men
Authors: Saito Masayuki , Yoneshiro Takeshi , Matsushita Mami
Published: June 2021

Objective

Brown adipose tissue (BAT), a site of non‐shivering thermogenesis, plays a role in body temperature regulation during cold exposure. The incidence and activity of human BAT show seasonal variations, being low in summer and high in winter. In the present study, we examined a possible role of BAT to seasonal variations in whole‐body energy expenditure (EE) and thermoregulation.

Methods and Results

Forty‐five healthy male volunteers underwent FDG‐PET/CT after 2‐h cold exposure at 19ºC in winter to estimate their maximal BAT activity, and were divided into high (n=30) and low (n=15) activity groups. Cold‐induced thermogenesis (CIT), the difference in EE at 27 and 19ºC, of the high activity group was higher in winter than summer (185.6 kcal/d v.s. 18.3 kcal/d, P < 0.001) whereas that of the low activity group unchanged (90.6 kcal/d, ‐46.5 kcal/d). The temperature of the eardrum (Tear) and the skin (Tskin) in the supraclavicular region close to BAT during cold exposure dropped more in the low activity group than the high activity group in winter, but not in summer. In contrast, the Tskin response in the other two regions distant from BAT was similar in the two groups in either season.

Conclusions

CIT increased from summer to winter in a BAT‐dependent manner, in parallel with cold‐induced changes in Tear/Tskin, indicating a significant role of BAT in the seasonal changes in EE and thermal response to cold exposure.
Central Control of Neurogenic Fever Following Subarachnoid Hemorrhage
Authors: Tupone Domenico , Cetas Justin
Published: June 2021

Subarachnoid hemorrhage (SAH) is a devastating form of stroke that is associated with autonomic dysfunction including neurogenic fever (NF) that contributes to an increase in mortality and worse outcomes. Drugs that inhibit cyclooxygenase (COX) are generally ineffective in treating NF which suggesting a different central mediator for the generation of NF than prostaglandins. The aim of this work was to determine in a rat model of SAH if (1) the generation of NF requires the same central thermogenic control and (2) the same thermogenic organs, as that required for the generation of PGE2 mediated fever.

In urethane chloralose‐anesthetized Wistar rats direct injection of blood into the subarachnoid space evoked an increase of brown adipose tissue sympathetic nerve activity (BAT SNA) and thermogenesis leading to a rapid increase in core temperature. Inhibition of central regions important for cold‐evoked and PGE2‐mediated thermogenesis, such as the dorsal medial hypothalamus and medullary raphe pallidus, promptly blocked the NF response. However the use of a COX inhibitor to prevent the production of PGE2, failed to completely inhibit NF.

We demonstrate for the first time that NF following SAH requires the same central neuronal thermoregulatory circuit and thermogenic organs involved in the generation of PGE2 mediated fever. A significant component of NF appears to be dependent on a different trigger than PGE2.

Merit Award Department of Veterans Affairs
Quantitative 4D Flow MRI during Hypoxia Identifies Non‐uniform Cerebrovascular Dysfunction in Young Adults with Metabolic Syndrome
Authors: Kellawan Jeremy , Harrell John , Roldan‐Alzate Alejandro , Wieben Oliver , Schrage William
Published: June 2021

Metabolic Syndrome (MetSyn) increases the risk of developing cerebrovascular diseases (e.g. stroke). We tested the hypothesis that MetSyn impairs cerebral dilation to hypoxia, and the attenuation would be observed primarily in the middle cerebral arteries. Macroscopic cerebral blood flow (CBF) was measured with a novel 4D Flow MRI approach at 3T using radial undersampling to quantify regional vasodilation to isocapnic hypoxia in 10 healthy controls (Con, 29±4 yrs) and 8 MetSyn patients (38±8 yrs). Blood pressure, O2 Saturation (SaO2), end‐tidal CO2 was measured and Cerebral Vascular Conductance (CVC=CBF/blood pressure*100mmHg) was calculated for five intracranial arteries: Middle [MCA] x2, Anterior [ACA] x2, and Basilar [BA] (ml/min/100mmHg). Hypoxia (5 min steady state) lowered SaO2 to ~85±2% (Fi O2 =0.1). End‐tidal CO2 was maintained (36±1 mmHg). Baseline CVC was 25% lower in MetSyn (750±57 Con vs. 562±75 MetSyn, p=0.03). Hypoxia increased total CVC (p<0.001) but the increase was 50% lower in MetSyn (Δ 127±18 Con vs. 62±22 MetSyn, p=0.03). Hypoxic dilation differed substantially by region: the greatest relative impairment occurred in ACA (Δ 20±4 Con vs. 8±3 MetSyn, p=0.02). CVC in the MCA (Δ 29±7 vs. 15±6, p=0.08) and BA (Δ 28±6 vs. 17±8, p=0.13) were not significantly lower in MetSyn. Therefore, MetSyn patients exhibit impaired hypoxic vasodilator responses with the negative effects directed more to regions of the brain supplied by the ACA. This non‐uniform cerebrovascular dysfunction occurs early in adulthood, which may contribute to poor cerebral vascular outcomes in MetSyn.
Acute Natural Cocoa Consumption Improves Cerebral Vasodilatory Capacity in College‐Aged African Americans
Authors: Patik Jordan , Hurr Chansol , Harrison Michelle , Brothers R Matthew
Published: June 2021

African Americans (AA) have increased risk for cerebral vascular disease including stroke and Alzheimer's disease relative to Caucasian Americans (CA). We recently reported that relatively young AA have attenuated cerebral vasodilatory response during rebreathing‐induced hypercapnia relative to CA. This study tested the hypothesis that acute natural cocoa (NC) consumption (13g NC) restores this response in AA. 14 college‐aged AA and 14 age / sex / body mass matched CA underwent a rebreathing protocol while cerebral blood velocity (CBFV) was measured before and 2 hr post consumption of a NC‐containing drink or an isocaloric NC‐free placebo (randomized order, single‐blinded). Cerebral vascular conductance (CVCI) was calculated as CBFV / MAP. The response to rebreathing was expressed as % of baseline CVCI (% CVCI). Following NC consumption the total range of increase and the maximal increase in %CVCI during hypercapnia was increased in the AA (P<0.01 for both variables) whereas there was no effect of NC consumption in the CA (P>0.05 for both variables). Following NC consumption the cerebral vascular responses were similar between AA and CA (P>0.05 for all variables). Consumption of the placebo beverage had no effect on cerebral vascular function in either cohort (P>0.05 for all variables). These data support the hypothesis that NC consumption can acutely augment cerebral vasodilatory capacity in AA.

This study was supported by institutional start‐up funds awarded to R. Matthew Brothers. The beverages were generously provided by the Hershey Company; Hershey, Pennsylvania.
Effect of Interleukin‐10 and Laminar Shear Stress on African American Human Umbilical Vein Endothelial Cells
Authors: Babbitt Dianne , Kim Ji‐Seok , Forrester Steven , Brown Michael , Park Joon‐Young
Published: June 2021

African Americans (AA) have a predisposition to heightened systemic inflammation and a high prevalence of hypertension. The purpose of this study was to evaluate the influence of interleukin‐10 (IL‐10) and laminar shear stress (LSS) on AA endothelial cells by measuring total endothelial nitric oxide synthase (eNOS) protein expression and its activated, phosphorylated form (p‐eNOS) at Serine 1177, as well as nitric oxide (NO) levels, in response to IL‐10 incubation and high physiological levels of LSS, used as a mimetic for aerobic exercise training (AEXT). Human umbilical vein endothelial cells (HUVEC) from an AA donor were cultured. The experimental conditions included Static, Static with IL‐10 Incubation, LSS at 20 dynes/cm2, and LSS at 20 dynes/cm2 with IL‐10 Incubation. Western blotting was used to measure eNOS and p‐eNOS protein expression in the cells. A modified Griess assay was used to measure NO production in the cell culture media. There were significant increases in p‐eNOS, eNOS, and NO in the LSS at 20 dynes/cm2 and LSS at 20 dynes/cm2 with IL‐10 Incubation experimental conditions when compared to the Static experimental condition. There were no other statistically significant differences, demonstrating that IL‐10 did not have an additive effect on eNOS activity in the present study. The significant increases in p‐eNOS, eNOS, and NO as a result of LSS in AA HUVECs suggest that AEXT may be a viable, nonpharmacologic method to improve vascular inflammation status and vasodilation, and thereby contribute to reduction of hypertension in the AA population.

AHA Scientist Development Grants 12SDG12070327

NIH Grant RO1 [HL085497]
The Angiotensin AT2 Receptor Modulates Adipose Epidermal Growth Factor Signaling to Control Resting Metabolic Rate
Authors: Littlejohn Nicole , Weidemann Benjamin , Markan Kathleen , Pearson Nicole , Naber Meghan , Morgan Donald , Potthoff Matthew , Rahmouni Kamal , Sigmund Curt , Grobe Justin
Published: June 2021

Transgenic “sRA” mice with brain renin‐angiotensin system hyperactivity express human renin via the synapsin promoter and human angiotensinogen via its own promoter. These mice exhibit an elevated resting metabolic rate (RMR) that is normalized by replacement of circulating angiotensin II (ANG), but the thermogenic tissue and ANG receptors involved are unknown. sRA mice exhibited a robust and specific elevation in uncoupling protein 1 (UCP1) expression and glucose uptake in inguinal adipose tissue. Chronic infusion of the AT2 receptor (AT2R) agonist, CGP‐42112a (CGP) into sRA mice increased weight gain and normalized RMR and inguinal UCP1 but had no effect on food intake or digestive efficiency. RMR suppression by CGP was not mediated through modulation of adipose sympathetic nervous activity or natriuretic peptide signaling. RNAseq‐based analyses implicated interference with epidermal growth factor (EGF) signaling in RMR‐suppressing effects of CGP in sRA mice. In wildtype C57 mice, CGP attenuated the RMR stimulatory effects of EGF. Finally, AT2‐deficient mice on the C57 background exhibited increased RMR compared to control mice. Collectively these results implicate the AT2R, acting upon inguinal fat to modulate EGF signaling, in the control of RMR.
Persistent Low Grade Inflammation is linked to Metabolic Dysfunction in HIV‐positive South African Females
Authors: Kruger Maritza , Coetser Alicia , Nell Theo
Published: June 2021

Protease inhibitors (PIs) is linked to adverse metabolic/anthropometric derangements, increasing the risk for cardiovascular diseases (CVD) onset in HIV‐infected individuals. As limited information is available regarding such PI‐mediated effects in the South African context, this cross‐sectional study evaluated an HIV‐positive female population (20‐40 years) in the Cape Winelands Health District. Participants were classed into: a) HIV‐negative, b) HAART‐naïve, and c) PI‐treated groups that underwent basic anthropometrical evaluations (weight, height, body mass index [BMI], hip circumference, waist circumference), and bioelectrical impedance measurements (fat mass, visceral adipose tissue and subcutaneous adipose tissue). An assessment of circulating biomarkers for inflammation (C‐reactive protein [CRP]) and metabolic dysfunction (leptin) was also completed. These data reveal that females from all three groups displayed elevated waist‐to‐hip ratios, with those on PI treatment exhibiting increased vs. matched controls. Moreover, HIV‐positive individuals displayed strong positive correlations between CRP and leptin (r=0.71) and leptin and BMI (r=0.85; p<0.05), and moderate positive correlations between leptin and total fat (r=0.61), CRP and total fat (r=0.49), as well as CRP and BMI (r=0.67). Our data show that persistent low grade inflammation is strongly linked to metabolic dysfunction and obesity in relatively young HIV‐positive South African females. Such changes therefore place female HIV‐positive individuals at increased risk for the future development of CVD that will require an integrated clinical strategy to help counter this growing threat.
Chronic Adrenergic Stress Causes Adrenergic β‐3 Receptor Up‐regulation in White Adipose Tissue of Burn Patients
Authors: Saraf Manish , Herndon David , Porter Craig , Chondronikola Maria , Chao Tony , Toliver Kinsky Tracy , Radhakrishnan Ravi , Sidossis Labros
Published: June 2021

Chronic adrenergic stress results in the browning of subcutaneous white adipose tissue (WAT), i.e. increased oxidative capacity and uncoupling protein 1 (UCP1) expression in rodents and possibly in humans. There are multiple adrenergic receptors that could mediate this response. The aim of this study was to determine if severe burn injury increases β3‐adrenergic receptors (β3AR) in human WAT.
Subcutaneous WAT was collected from ten burned (11±3 yrs; 59±21% total body surface area burned) on two separate occasions (10±8 (early) and 34±24 (late) days post injury) and five non‐burn children (10 ± 5 years). Whole body metabolic rate and WAT thermogenesis were measured. Histology, immunohistochemistry, ELISA and q‐PCR were performed in WAT.
Resting energy expenditure rate (35±5.9 vs 45±7 Kcal/kg/day), p<0.01) and WAT mitochondrial respiration (1.5±0.3 vs. 0.56±0.1 pmol/sec/mg, p<0.05) were higher in late after burn compared to early after burn, respectively, suggesting increased whole body and adipose tissue oxygen consumption. β3AR mRNA and protein expression in WAT progressively increased over time post burn. Further, UCP1 (p<0.01), but not UCP2, UCP3 and UCP4, mRNA expression was higher in WAT at later, compared to early, times post‐burn. Similarly, UCP1 protein was significantly increased in the late burn group compared to healthy controls (22.9±4.5ng/mg vs 2.7±0.3; P<0.001). In summary, WAT β3AR up‐regulation in WAT is associated with increased UCP1 and oxygen consumption in WAT and increased whole body oxygen consumption. The possible contribution of β3ARs to browning of WAT in humans with severe burns is being investigated.
The Intakes of Salt and Dietary Sodium among Chinese Adults
Authors: Yu Dongmei , Fang Hongyun , Zhao Liyun
Published: June 2021

Objective

To describe the age‐standardized mean population intake of salt and sodium in Chinese adults in 2010‐2012.

Methods

Data is from the Chinese Nutrition and Health Surveillance in 2010‐2012. A stratified multistage cluster sampling was used from 31 provinces, autonomous regions, and municipalities and selected 150 districts/counties. The sample was selected through the method of Probability Proportion to Size (PPS). The study objects were adults aged 18 and over. The average of salt and dietary sodium intake was calculated based on dietary measurement. The investigation conducted a strict quality control. Age‐standardized results were calculated using the population data from the National Bureau of Statistics in 2009.

Results

The mean intake of salt was 10.4 g and it was higher in men (11.1g) than that of in women (9.6g). The highest salt intake was the age group of 40‐49, 50‐59 and 60‐69. The adults in rural (10.8g) had a higher salt intake than that of urban (10.0g). An average of salt intake was increased gradually in big city, medium /small city, rural and poor rural. The mean intake of salt was 5335.7mg and it was higher for men (5744.9 mg) than for women (4918.9 mg). The age groups of 40‐49, 50‐59 and 60‐69 had higher sodium intake. The adults in rural (5352.3 mg) had a slightly higher sodium intake than urban (5319.5 mg). Overall, the mean intake of sodium in medium/ small city, rural and poor rural was similar while big city was lowest.

Conclusions

In 2010‐2012, the mean salt and sodium intake among Chinese adults was still in a very high level.
Trends of consumption of foods containing added sugars and associated factors among adults of 9 provinces in China
Authors: Zhao Liyun , Yu Dongmei , Li Donghua
Published: June 2021

Objective

To analysis the status of consumption of added sugar foods and its associated factors among adults in 9 provinces in China from 1997 to 2009.

Methods

Data resource was from China Health and Nutrition Survey. The information of consumption of added sugars foods was based on 24 hours food recall. A multi level model is used for analyzing the influence factors.

Results

The consumption of added sugars foods in adults was increased during 1997(8.9%) to 2009(25.4%). The intake is higher in female and the group of 18‐44 was the highest. Urban adults showed a higher intake than that of rural. The main consumption time is breakfast and the main consumption location is at home in China from 1997 to 2009. The intake of beverage was 3.5%, 0.9%, 2.6%, 3.9% and 16.1% in 1997, 2000, 2004, 2006 and 2009, respectively. Three levels of logistic regression model showed that the factors influencing the consumption of sugary food intake were urban or rural areas, age, gender, level of education and household income.

Conclusion

Sugary food consumption among adults is increasing in 1997‐2009 in 9 provinces in China.
Epigenetic Silencing of Netrin is associated with Memory Loss by High Methionine, Low Folate and Vitamin B6/B12 containing diet
Authors: Kalani Anuradha , Kamat Pradip , Lominadze David , Tyagi Neetu
Published: June 2021

High methylation is known to silence genes of many proteins, which can be associated with changes in cognitive function. Loss of memory due to epigenetic modifications, called memory‐epigenetics was studied. We hypothesized that high methionine (met) diet leads to memory impairment by increasing global DNA methylation and therefore, silencing the netrin gene, which encodes the glycoprotein involved in neurogenesis, axonal guidance and maintenance of the synaptic plasticity. Wild type (C57BL/6J) mice were fed diet containing excess met (1.2%), low‐folate (0.08 mg/kg), vitamin B6 (0.01 mg/kg), and B12 (10.4 μg/kg) for 6 weeks. Mice were weekly examined for memory function. Our results using a passive avoidance test confirmed a loss in fear motivated long‐term memory starting from 4th week of diet. The loss of memory was associated with an increase in global DNA methylation in brain samples of mice fed with diet. We found a time‐dependent decrease in netrin protein expression and an increase in methylation of netrin gene promoter, defined by restriction digestion and PCR analysis, in mice fed with diet. The increase in methylation of netrin gene promoter was validated by high resolution melting analysis. In addition, it was found that the level of netrin receptor DCC (deleted in colon cancer) was decreased in mice on diet. Taken together, these results confirm that diet containing high met, low folate and vitamin B6/B12 can induce defects in learning and memory. Furthermore, the data indicates that decrease in netrin level due to hypermethylation of its gene promoter can be associated with memory loss. This work was supported by NIH grant HL107640‐NT.
Linagliptin, a dipeptidylpeptidase 4 inhibitor, ameliorates indomethacin‐induced enteropathy via GLP‐2 pathway
Authors: Akiba Yasutada , Kaunitz Jonathan
Published: June 2021

Glucagon‐like peptide‐2 (GLP‐2) is an intestinotrophic hormone secreted from enteroendocrine L cells. We have reported that dipeptidylpeptidase 4 (DPP4) inhibition prevents formation and promotes healing of indomethacin (IND)‐induced small intestinal ulcers in rats via GLP‐2 release and GLP‐2 receptor activation. We thus further examined the effect of the clinical DPP4 inhibitor linagliptin (LNG) on IND‐induced enteropathy.

Small intestinal ulcers were induced by IND treatment (10 mg/kg, sc) in rats. LNG (0.1 – 5 mg/kg) was given once before IND for prevention, and for healing, once daily for 2 days starting 1 day after IND treatment.

LNG treatment dose‐dependently reduced ulcer scores, accompanied by an increase of portal venous GLP‐2 concentrations. LNG promoted ulcer healing of IND‐induced intestinal ulcers. LNG‐induced healing was reversed by a GLP‐2 receptor antagonist. Ulcer healing was further accelerated by co‐treatment with L‐alanine plus inosinate, an umami taste receptor agonist. Compared to LNG, the DPP4 inhibitor NVP‐728, metabolized in the kidney, had a little effect on the enteropathy, suggesting that a long‐acting, entero‐hepatically circulated DPP4 inhibitor may be more efficacious in the prevention of intestinal mucosal damage.

These results confirm our previous study that DPP4 inhibition prevents ulceration and promotes ulcer healing of NSAID‐induced enteropathy, enhanced by the luminal umami taste receptor activation, suggesting that GLP‐2 release enhanced by DPP4 inhibition and nutrient receptor activation is useful for the treatment of NSAID‐induced enteropathy.

Supported by Boehringer Ingelheim, VA Merit Review, NIH R01 DK54221
The Role of Suppressor of Cytokine Signalling 3 (SOCS3) in the Regulation of Intestinal Epithelial Cell Turnover in a Helminth Model
Authors: Shaw Elisabeth , Smith Emily , Else Kathryn , Rigby Rachael
Published: June 2021

Gastrointestinal epithelial cells (IEC) act as a first line of defence against invading pathogens and are replenished every 4‐5 days. An increase in IEC turnover aids the expulsion of intestinal pathogens including helminth infection. SOCS3 limits IEC proliferation with its loss associated with hyperproliferation and increased tumour growth in intestinal injury and cancer models. This study investigates SOCS3 effects on IEC turnover, outcome of infection and biochemical changes in response to infection in an in vivo Trichuris muris model.

Mice with IEC SOCS3 conditional knockdown and controls were infected with T. muris. Crypt depth, cell proliferation rates, worm burden and immune response were assessed. Protein expression assessed by western blotting or immunohistochemistry.

Increased SOCS3 expression was observed in cecum of T. muris susceptible vs. resistant mice strains. This supported our hypothesis that increased SOCS3 may limit IEC turnover and parasite expulsion. IEC deletion of SOCS3 did not lead to resistance to infection although a trend towards increased expulsion, compared to controls, was observed. At 35 days post infection an increase in proliferation of cells in cecal crypts was observed with no change in crypt depth in knockdown animals, supporting an increase in cell turnover. No difference in crypt dynamics was apparent in early stages of T. muris infection. Loss of SOCS3 was associated with altered indoleamine 2,3‐dioxygenase (IDO) expression in goblet cells.

During parasitic challenge SOCS3 modulates IEC proliferation, potentially via a mechanism mediated though altered IDO.

Medical Research Council G1100211/1
Variations on the Traditional Anatomy Practical Examination: Faculty and Student Perceptions of Assessment Strategies at a New Medical School
Authors: White Erin , Devine Jessica
Published: June 2021

The Frank H. Netter MD School of Medicine, in its inaugural year, provided a case study for observing methods of anatomy assessment. Anatomy was taught to first year medical students as part of an integrated curriculum, during which four anatomy practical exams were administered. While each exam employed a common steeplechase format, notable variations were implemented as different faculty members took their turn leading the coursework and designing assessments; these included differences in question format, proportion of higher versus lower order questioning, and timing and procedures. Interviews and focus groups were conducted to compare perceptions between and among students and faculty regarding the effectiveness of the various exams for measuring student learning outcomes. Among the faculty, professors reported varying goals for students, and, accordingly, core anatomy faculty endorsed the format of exam(s) with which they were most intimately involved but acknowledged not all goals were formally assessed. Students' perceptions of course goals were also mixed and when asked which variation they thought demonstrated the best or fairest assessment, students were divided among the four exams. Furthermore, students identified the respective strengths of the exams in assessing different skills, but disagreed on which of those skills fell within the scope of the course. Given the range of faculty goals, no single exam could be deemed most effective, suggesting a combination of formats be explored for future assessments. In addition, further study is needed to determine if improved communication of goals would ensure students have the same expectations as faculty for learning outcomes.