bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of the yeast mitochondrial respiratory complex IV activity by the major isoform of the ADP‐ATP carrier
Authors: Ogunbona Oluwaseun Basit , Baile Matthew G , Claypool Steven M 
Published: November 2023

Protein‐protein interactions underlie many biological processes. The ADP/ATP carrier (AAC) forms an evolutionarily‐conserved, cardiolipin‐dependent interaction with the respiratory supercomplexes. Interestingly, in yeast lacking Aac2p the activity of respiratory complex IV (cytochrome c oxidase or COX) is reduced suggesting that this interaction is of functional significance. The regulation of COX activity and by extension, of oxidative phosphorylation by AACs is not clearly understood. Here, we leveraged a transport‐dead pathogenic AAC2 point mutant discovered in a patient with hypertrophic cardiomyopathy and mild myopathy to determine whether the reduction in complex IV activity in the absence of Aac2p reflects the absence of the interaction between AACs and components of the electron transport chain and/or the absence of nucleotide transport (i.e. Aac2p function). Using a CRISPR‐Cas9 based strategy, we established yeast strains with either an AAC2 frameshift deletion or an AAC2A137D point mutation in the presence or absence of the minor AAC isoforms, Aac1p and Aac3p. Importantly, the pathogenic A137D allele of AAC2 is expressed normally and still interacts with components of the yeast respiratory supercomplex but is unable to support growth on respiratory media due to its inability to transport ADP/ATP. Interestingly, complex IV activity is significantly reduced in yeast strains lacking Aac2p activity (P<0.05). Moreover, in the absence of Aac2p function, the expression levels of complex IV subunits encoded by the mitochondrial genome are specifically reduced. Thus these new pieces of evidence suggest that Aac2p nucleotide transport function and not the physical interaction with the respiratory supercomplexes is required for full COX activity. Mechanistically, the absence of Aac2 function specifically impairs expression of mitochondria DNA‐encoded COX subunits. Given that oxidative phosphorylation accounts for the majority of cellular ATP production, uncovering this important line of regulation is critical for further understanding of the various role the mitochondria play in healthy and diseased state.Support or Funding Information“THIS WORK WAS SUPPORTED BY AMERICAN HEART ASSOCIATION GRANT #15PRE24480066 (Oluwaseun Ogunbona) and NATIONAL INSTITUTES OF HEALTH GRANT NIH/NHLBI 1R01HL108882 ‐ 01A1 (Steven Claypool)
Acceleration of Skin Barrier Restoration via Activation of Transient Receptor Potential Vanilloid 3 (TRPV3) by Agrimonia pilosa Leaf
Authors: Nam Joohyun , Kim Woo Kyung 
Published: November 2023

The formation and maintenance of the skin barrier are controlled by the proliferation and differentiation of epidermal keratinocytes, and impaired skin barrier homeostasis resulting from abnormal keratinocyte function causes many skin disorders, including atopic dermatitis and psoriasis. Keratinocyte differentiation is regulated by intra‐ and extracellular calcium ion concentrations. Recently, it was reported that the transient receptor potential vanilloid 3 (TRPV3) ion channel is functionally expressed in human keratinocytes. Activation of TRPV3 increased intracellular calcium signaling, which in turn increased transglutaminase 1, 3 activities as well as the subsequent formation of cornified cell envelopes in the epidermis. It was also reported that activation of TRPV3 promotes epithelial cell proliferation and wound healing in oral epithelia. Thus, TRPV3 activation may be a potential therapeutic target for skin barrier recovery in various dermatological diseases. The leaves of Agrimonia pilosa Ledeb (Rosaceae, AP), which have traditionally been used in East Asia to treat conditions including sore throat, parasitic infection, and eczema, have been reported to possess anti‐inflammatory and anti‐allergic effects in lipopolysaccharide‐ and ovalbumin‐induced mouse models. We performed whole‐cell patch‐clamp and tape stripping tests to determine whether AP extract enhances barrier recovery via TRPV3 activation. We found that APH2O potently activated human TRPV3 and subsequently activated TGase activity in vitro. We also confirmed that topical application of APH2O improved the recovery of skin barrier disruption induced by tape stripping in mice. APH2O may be useful for preventing and treating skin barrier disorders, including inflammatory skin diseases such as atopic dermatitis and psoriasis.Support or Funding InformationThis research was supported by the Convergence of Conventional Medicine and Traditional Koran Medicine R&D program funded by the Ministry of Health & Welfare through the Korean Health Industry Development Institute (SHIDI) (To. JH Nam, HI15C0256).
TASK1 Channels as a pH Sensor in Mouse Adrenal Medullary cells: Analysis With Gene Knockout
Authors: INOUE Masumi , MATSUOKA Hidetada , HARADA Keita 
Published: November 2023

Two‐pore K+ (2PK) channels constitute one of the K+ channel families, comprising 15 isoforms in humans. These isoforms, which are divided into six subfamilies, form a homodimer or heterodimer channel with isoforms in the same or different subfamilies. We have elucidated that acidosis induces catecholamine secretion through inhibiting TASK (TWIK‐related acid‐sensitive K+)‐like channels in rat adrenal medullary (AM) cells. TASK channels belong to the TASK subfamily in 2PK, comprising TASK1, TASK3, and TASK5. The expression of TASK1, but not TASK3, in rat AM cells was recognized by immunoblotting. However, RNAs for both TASK1 and TASK3 were clearly recognized with RT‐PCR in the rat adrenal medulla. Furthermore, in‐situ hybridization studies in mouse adrenal glands, strong and weak signals for TASK1 mRNAs were detected in adrenal cortex and adrenal medulla, respectively, and strong signals for TASK3 were recognized in both adrenal cortex and adrenal medulla. Thus, the present experiment was aimed to elucidate the molecular identity of TASK channels in mouse AM cells with the knockout (KO) of TASK genes. The perforated patch clamp technique was used to record the whole‐cell current. The inward current reversibly developed in response to step changes in external pH from 7.4 to 6.0 in wild‐type AM cells. The amplitudes of this acidosis‐induced current were well approximated by a logistic equation with IC50 of pH7.07. The pH‐dependent production of current was abolished by the genetic depletion of TASK1, but not TASK3. However, the holding current level at −50 mV and the slope conductance over the voltage range of −50 mV to −70 mV did not significantly differ between in wild‐type and TASK1‐KO AM cells. Immunocytochemistry revealed that TASK1‐like immunoreactivities (IRs) were mainly present at the cell periphery in wild‐type AM cells, but not in TASK1‐KO. TASK3‐like IRs were rarely detected in wild‐type AM cells and not enhanced in TASK1‐KO. A decrease in external solution induced catecholamine secretion in wild‐type AM cells, but not TASK1‐KO. These results indicate that TASK1 channels function as a pH sensor in mouse AM cells.Support or Funding InformationGrants from Japan Society for the Promotion of Science and The Salt Science Research Foundation
Brain Perivascular Macrophages Contribute to Developing Hypertension via Sensing Chronic Peripheral Inflammation
Authors: Iyonaga Takeshi , Shinohara Keisuke , Kishi Takuya , Tsutsui Hiroyuki , Hirooka Yoshitaka 
Published: November 2023

BackgroundRecent studies suggest an association between inflammation and hypertension. The essential pathophysiological mechanism by which peripheral inflammation induces sympathetic hyperactivity and blood pressure elevation is not fully clarified. Sympathetic nerve activity is regulated by the brain, which is separated from various peripheral substances by the blood brain barrier (BBB). Brain perivascular macrophages in the BBB can transfer peripheral inflammatory information to the brain. Therefore, we investigated whether peripheral proinflammatory cytokines accompany the development of hypertension, and if so, whether or not brain perivascular macrophage depletion attenuates the increase in blood pressure in hypertensive animal models.Methods and ResultsPeripheral proinflammatory interleukin‐6 levels measured by enzyme‐linked immunosorbent assay did not differ between young pre‐hypertensive spontaneously hypertensive rats (SHR) and control Wistar Kyoto rats (WKY, 8‐week‐old SHR 64.8±9.5 pg/ml vs. 8‐week‐old WKY 42.8±9.5 pg/ml, p=0.15, respectively, n=4 for each). In adult hypertensive SHR, however, the interleukin‐6 level was significantly greater than that in WKY (12‐week‐old SHR 112.5±15.2 pg/ml vs. 12‐week‐old WKY 62.4±15.2 pg/ml, p<0.05, n=5 for each). Clodronate, a unique agent that induces apoptosis of perivascular macrophages, was administered intracerebroventricularly to 6‐week‐old SHR to investigate the role of brain perivascular macrophages in blood pressure elevation in SHR. Although established natural history of blood pressure in SHR clearly showed that mean arterial pressure would be elevated to approximately 120–125 mmHg at 8 weeks of age, intracerebrovantricular injection of clodronate successfully attenuated telemetered mean blood pressure elevation from 6 to 8 weeks of age (from 113.3±4.2 mmHg to 114.7±4.2 mmHg, n=2) in SHR.ConclusionBrain perivascular macrophages potentially contribute to developing hypertension via sensing chronic peripheral inflammation.
The Sex‐Specific Impact of Aging on the Blood Pressure Response to Exercise
Authors: Trinity Joel Douglas , Layec Gwenael , Hart Corey R , Richardson Russell S 
Published: November 2023

An exaggerated increase in blood pressure (BP) during exercise has been linked to cardiovascular disease (CVD) and may precede the onset of overt CVD. Importantly, the prevalence of CVD is not evenly distributed between men and women across the lifespan and the impact of age and sex on the BP response to exercise remains unclear. Therefore, utilizing an integrative approach, this study examined central and peripheral hemodynamic responses and skeletal muscle metabolic responses to moderate intensity leg exercise in 40 activity‐matched young (n=20, 23±1 yr) and old (n=20, 73±2 yr) subjects. Central hemodynamics (finometer), popliteal artery blood flow (Doppler ultrasound), and skeletal muscle metabolic parameters (phosphorous magnetic resonance spectroscopy, 31P‐MRS) were measured during 5 min of submaximal dynamic plantar flexion exercise. Exaggerated exercise‐induced increases in systolic BP (SBP) and mean arterial pressure (MAP) were evident only in the old women (SBP: Δ47±6 mmHg, MAP: Δ30±4 mmHg) as all other groups exhibited similar increases in SBP (old men: Δ27±8; young men: Δ25±4; young women: Δ22±3 mmHg) and MAP (old men: Δ16±5; young men: Δ22±4; young women: Δ17±2 mmHg). Furthermore, unlike the young women, the old women failed to exhibit a reduction total peripheral resistance during exercise (young women: Δ −2.8±0.5, old women: Δ 1.0±1.0 mmHg/L/min, p < 0.05). Aging, independent of sex, was associated with attenuated central hemodynamic changes in stroke volume and cardiac output, while popliteal blood flow, O2 delivery, and high energy phosphate levels were similar between young and old. In conclusion, the combination of aging and the female sex results in an exaggerated BP response to exercise, likely a result of sustained elevations in total peripheral resistance during dynamic exercise.Support or Funding InformationThis project was supported by the American Heart Association (14SDG1850039) and the VA office of Research and Development (1IK2RX001215, E1433‐P, E1697‐R).
Housing temperature alters glucose metabolism in response to short‐term overfeeding in lean mice
Authors: Clayton Zachary Stephen , McCurdy Carrie 
Published: November 2023

While diet induced obesity is an established risk factor for the development of insulin resistance, the exact mechanisms that initiate the insulin resistant phenotype are unknown. Systemic insulin resistance and glucose intolerance have been observed in as little as three days of high‐fat diet (HFD) feeding in lean mice. In most laboratories, mice are housed between 20–24°C, which is below their lower critical temperature (~30°C). Increased thermal stress has been shown to increase browning of white adipose tissue, alter lipid trafficking and impair immune function, which may lead to confounding results in metabolic data. Additionally, food intake and energy expenditure, two factors that significantly impact metabolic health, decrease with increasing ambient temperature. Thus, it is imperative to compare the metabolic and behavioral outcomes of high‐fat fed mice across typical housing temperature (22°C) and at their critical temperature (30°C). We hypothesized that mice will become glucose intolerant in as little as one day of HFD, and mice housed at 22°C will be protected from acute HFD induced impairments in glucose tolerance. To test this, we have studied an acute (1, 3 and 5 days) time‐course of either high‐fat feeding (45% Cal from fat) or low‐fat feeding (10% Cal from fat) in lean mice, at 22°C and 30°C. We observed a significant increase in glucose area under the curve (AUC) (P < 0.01) as soon as one day of HFD, which was not augmented by three or five days of HFD, without accompanied change in weight or body composition. However, separating our data by housing temperature, a significant increase in glucose AUC after one day of high‐fat feeding is only seen in mice housed at 30°C. Furthermore, the glucose AUC following one day of HFD at 30°C is similar to the glucose AUC observed after 5 days of HFD at 30°C. Behavioral outcomes such as food intake (significantly increased P < 0.01), oxygen consumption (significantly decreased (P < 0.05), and physical activity (significantly decreased P < 0.01) were also affected by one day of HFD relative to controls, and results were not exacerbated across three and five days. Taken together, we have shown that mice become glucose intolerant in as little as one day of HFD, and that the temperature at which the mice are housed is critical to accurately determining the metabolic phenotype.Support or Funding InformationNIH DK095926‐01
Treatment with Streptozotocin (STZ) causes hypoglycemia and alters the stability of reference genes for real‐time PCR analysis in the liver of channel catfish
Authors: Nevarez Ericka , Ordonez‐Castillo Norelia , Spainhour Rebekah , Kobayashi Yass 
Published: November 2023

Genetically selected channel catfish for increased growth often develops phenotype similar to human obesity, suggesting that channel catfish may be a model organism to investigate human metabolic disorders. Streptozotocin (STZ) treatment induces hyperglycemia in mammals and some fish species. However, the effects of STZ treatment on blood glucose level as well as other physiological parameters in channel catfish have never been examined in detail. In this study, we tested the hypothesis that treatment with STZ affects body weight, blood glucose level, and hepatic expression of house‐keeping genes. Juvenile channel catfish (28.3 ± 2g) were treated with 0, 3.6, 36, 180, or 360 mg/kg STZ intraperitoneally on day 0 (n=4 fish/treatment). On day 7, blood glucose level was measured and blood, liver, muscle and brain samples were collected. Expression of five common housekeeping genes (beta‐macroglobulin, alpha‐tubulin, 18s ribosomal RNA, beta‐actin, and GAPDH) were measured using real‐time PCR. The weight of fish did not change between days 0 and 7 among all treatments. Blood glucose levels were lower in fish treated with 180 or 360 mg/kg STZ compared to fish treated with 0 mg/kg STZ. Treatment with STZ at higher doses altered expression of 4 housekeeping genes. Expression of beta‐macroglobulin, alpha‐tubulin, and beta‐actin mRNA was higher in fish treated with higher doses of STZ compared to 0 mg/kg STZ. In contrast, expression of GAPDH mRNA tended to be less in 360 mg/kg STZ than 0 mg/kg STZ. Expression of 18s rRNA was not affected by STZ treatment. Rather than causing hyperglycemia, treatment with high doses of STZ decreased blood glucose level in channel catfish, suggesting a difference in glucose metabolism exists between channel catfish and humans.Support or Funding InformationThis study is supported by APS IOSP fellowship program and Kansas Idea Network of Biomedical Research Excellence (P20GM10348).
MicroRNA‐214–Mediated Suppression of Endothelial‐Notch2 Signaling Potentiates Vascular Endothelial Cell Migration and Proliferation in Pulmonary Arterial Hypertension
Authors: Sahoo Sanghamitra , Sembrat John C , Goncharova Elena A , Rojas Mauricio , Pagano Patrick J 
Published: November 2023

BackgroundPulmonary arterial hypertension (PAH) develops when pulmonary vascular resistance rises sharply, leading to right heart failure and death. Most studies have focused on attenuating lung vessel constriction; however, little is known about the mechanisms controlling intimal proliferation and luminal obstruction. Numerous studies suggest that the Notch signaling influences vascular cell proliferation and migration, hallmark features of neointimal growth. Despite this, a role for Notch2 in PAH is entirely unknown. We previously reported that microRNA‐214 (miR‐214) causes smooth muscle cell (SMC) proliferation and de‐differentiation. In this study, we hypothesize that miR‐214 inhibits lung endothelial Notch2 resulting in increased proliferation and migration in PAH.Methods and ResultsqPCR of human pulmonary artery endothelial cells (HPAECs, Lonza) showed that hypoxia (24 hr, 1% O2) upregulated miR‐214 by ~ 2‐fold. The miR‐214 rise was concomitant with reduction in Notch2 expression (0.61±0.08‐fold vs. normoxia, p< 0.05), and activation (0.50±0.01‐fold vs. normoxia, p< 0.01, by Western blot). Immunofluorescence staining on lung sections of PAH patients showed reduced expression of Notch2 in the intima of the vessel wall compared to non‐PAH samples. qPCR of pulmonary arteries from PAH patients showed significant reductions in Notch2 mRNA (0.30±0.08‐fold vs. control patients, p<0.05). Luciferase reporter assay demonstrated miR‐214 binding to Notch2 3′UTR with a marked reduction (~90%) in activity in HEK‐293 transfected with miR‐214 mimic compared to control. miR‐214 overexpression under normoxic conditions increased HPAEC migration (1.75±0.22‐fold vs. scrambled, p< 0.05), while hypoxia‐induced migration was attenuated by miR‐214 antagomiR. Finally, HPAEC pretreatment with Notch2 siRNA under normoxic conditions increased endothelial cell migration (1.5 ±0.01‐fold vs. scrambled control, p<0.05) and decreased the expression of p21cip (0.55±0.09‐fold vs. scrambled control, p<0.05).ConclusionsThe current study identifies a new signaling axis mediated by miR‐214‐Notch2 in the human pulmonary vascular endothelium that could contribute to pathophysiological changes to the intima and the progression of pulmonary arterial hypertension.Support or Funding InformationThis work was supported by National Institutes of Health grants, R01 HL112914 and P01HL103455 (PJP), R42‐AA024003 and R01‐CA162306 (MR) and R01HL113178 (EG). The study was supported by the Institute for Transfusion Medicine and the Hemophilia Center of Western Pennsylvania.
Spirulina Extracts Improve Vascular Function of Arteries with Vascular Damage
Authors: Alameda M. Teresa , Ruiz Mireya , Villalpando Diva M. , Verdasco‐Martín Carlos M. , Plaza Ignacio , Otero Cristina , Ferrer Mercedes 
Published: November 2023

Vascular dysfunction is characterized by an unbalance between relaxing and contracting factors, usually in favor of the latest ones, that maintained along the time could lead to cardiovascular diseases, such as hypertension. On the other hand, organ culture has been described to induce phenotypic changes in endothelial cells similar to those observed in some cardiovascular pathologies. In both hypertension and in organ culture‐induced vascular damage, the release and action of nitric oxide (NO) play a pivotal role in the control of vascular function. Recently, increasing attention is paying to the use of the microalgae Spirulina for nutritional interventions due to antioxidant and anti‐inflammatory properties. Therefore, the aim of this study was to analyze the effects of aqueous Spirulina extract on the release and function of NO in these two experimental models of vascular dysfunction. For this purpose, thoracic aorta from Sprague‐Dawley (SD), spontaneously hypertensive rats (SHR) and its normotensive Wistar‐Kyoto (WKY) rats (18–20 weeks old) were used. Organ culture‐induced vascular damage was obtained by incubating aortic segments from SD rats for 20 hours at 37° C in serum free culture medium, and the effect of aqueous Spirulina extract (0.1 % w/v; for 3 h) on the NO release and on the vasodilation induced by acetylcholine (Ach) were analyzed. In aortic segments from SHR and WKY rats, the effect of Spirulina extract on NO release and on the Ach‐induced response in endothelium‐intact and endothelium‐denuded arteries were investigated. The results showed that the induced vascular damage strongly increased the release of NO, while the incubation with the Spirulina extract decreased that release up to similar levels found in intact arteries. The Ach‐induced response was not modified after vascular damage or Spirulina incubation. In aortic segments from SHR and WKY rats Spirulina extracts increased the release of NO more in arteries from SHR than that of WKY rats. In endothelium‐intact arteries, Spirulina extracts increased more the Ach‐induced response in WKY rats than in those of SHR. Conversely, in endothelium‐denuded arteries, Spirulina increased the Ach‐induced relaxation more in SHR than in those of WKY rats. These findings indicate the beneficial role of Spirulina extracts on the NO participation in the vasodilator responses of these two experimental models of vascular dysfunction, although endothelium‐independent mechanisms are also involved.M.T.A. and M.R. equally contributed to this workSupport or Funding InformationSupported by grants (to M. F.) from the Fondo de Investigaciones Sanitarias (PI1100416), Comunidad de Madrid (S2013/ABI‐2783, “INSPIRA1‐CM”) and Fondo Europeo de Desarrollo Regional.