bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pretreated with Evans blue can prevent mast cell degranulation and compound 48/80 induced anaphylaxis
Authors: Chen Yu‐Tong , Lin Shiuan‐Yea , Lue Sheng‐I , Lu Tzong‐Shi , Fu Yaw‐Syan 
Published: November 2023

This study demonstrated that pretreated with Evans blue could prevent hypotension, plasma leakage, mesenteric mast cells degranulation induced by compound 48/80, but only prevent mast cells degranulation by substance P. Sprague‐Dawley rats were cannulated for monitoring arterial blood pressure, and femoral vein was cannulated for i.v. injected with substance P (3 μg/kg) and compound 48/80 (200 μg/kg) by syringe pump over 2 min to induced systemic inflammation. Half of animals were pretreated with i.v. injection of a dose of Evans blue (50 mg/kg) 20 sec prior to the drug infusion, and the remaining half of animals were post‐treated with same dose Evans blue after drug infusion immediately. The result of our study showed Evans blue pretreatment could complete inhibit compound 48/80‐induced hypotension, peripheral mast cell degranulation, and edema formation in various organs including the airways, esophagus, and skin. The pretreatment of Evans blue only had few effects on hypotension and plasma leakage induced by substance P, but could prevent the mesenteric mast cell degranulation. In conclusion, Evans blue pretreatment could inhibit the mast cells degranulation and that may be the main mechanism for prevent animals from C48/80‐triggered anaphylaxis and systemic inflammation.Support or Funding InformationKMU‐TP104E34, KMU‐O105001
Validation of the doubly labeled water method using integrated cavity output spectroscopy against isotope ratio mass spectrometry and whole‐room indirect calorimetry
Authors: Melanson Edward L. , Plasqui Guy , Wouters Loek , Kohrt Wendy S. , Swibas Tracy , Catenacci Vicki A. , Speakman John R. , Berman Elena S. 
Published: November 2023

BackgroundThe doubly‐labeled water (DLW) method is the gold standard methodology for determination of free‐living energy expenditure. Isotope enrichments have traditionally been determined by isotope ratio mass spectrometry (IRMS), but new technologies are emerging, such as off‐axis integrated cavity output spectroscopy (OA‐ICOS). We have previously shown that compared to IRMS, OA‐ICOS provides comparable isotope enrichments of standard waters and of human urine samples, and to carbon dioxide (CO2) production measured using whole‐room indirect calorimetry (IC). In this study, we compared CO2 production in humans measured using OA‐ICOS and IRMS to simultaneous whole‐room indirect calorimetry (IC) measurements over a period of 7 days.Methods12 subjects (5 male, 7 female; age=24 to 63 yrs.; body mass index=19.4 to 46.4 kg/m2) were studied for 7 consecutive days in the IC. Prior to entry on the first day, subjects consumed an oral dose of 0.25 g H218O (95% APE) and 0.14 g 2H2O (99.8% APE) per kg of total body water (estimated as 73% of fat free mass, measured using Dual X‐ray Absorptiometry). Urine samples were obtained daily, and the samples on day 1 and 8 were used to measure average CO2 production over the 7 days using both OA‐ICOS and IRMS.ResultsAverage estimated CO2 production by IC, TIWA, and IRMS was 413.6±69.4, 400.6±74.5, and 385.5±71.1 L/day (P=0.03), respectively (mean±SD). Post‐hoc comparisons indicated significant differences in CO2 production between IRMS and IC (95% confidence interval of difference = +3.7 to +52.5 L/min), but not between TIWA and IC (−11.4 to 37.5 L/min) or TIWA and IRMS (−9.3 to 39.5 L/min). CO2 production measured with the different instruments were significantly correlated: TIWA vs. IC (r=0.89), IRMS vs. IC (r=0.93), IRMS vs. TIWA (r=0.86).ConclusionsOA‐ICOS produces valid measurements of CO2 production compared to IC, and comparable results to IRMS. OA‐ICOS provides a valid and viable alternative to IRMS for DLW studies in humans.Support or Funding InformationThis work was supported by NIH SBIR 1R43DK093362‐01, The Colorado Nutrition and Obesity Research Center (P30 DK048520) and Colorado Clinical and Translational Science Institute (UL1 TR000154).
Experimental approaches for studying cell water and volume regulation in apoptotic cells
Authors: Model Michael A 
Published: November 2023

Shrinkage and water loss are unique features of apoptosis. Despites decades of research, their exact roles, as well as the mechanisms of development, are poorly understood. Research in this area requires the ability to measure cell volume, intracellular water content, intracellular ion concentrations and the assessment of specific membrane permeability.Cell volumeThe volumes of adherent cells can be conveniently measured by transmission‐through‐dye (TTD) microscopy. This method is based on exclusion of a strongly absorbing extracellular dye by intact cells. The method can be realized on any transmission light microscope at nearly zero cost. TTD provides accurate measurements, even on severely deformed cells (which are common during apoptosis) and is compatible with fluorescence.Cell waterCell water is another essential parameter involved in apoptosis. Apoptotic shrinkage can occur by water expulsion as well as by cell fragmentation, and to discriminate between these two mechanisms, direct water measurements must complement measurements of the cell volume. Intracellular water is directly related to the average refractive index; the latter can be obtained from the the volume (which can be determined by the TTD) and from the delay of the light wave crossing the sample. A simple and effective way to measure the phase is based on the transport‐of‐intensity equation (TIE). Two transmission brightfield images are collected at different distances to the sample, and the phase is restored by solving the TIE. A Matlab‐based code for solving TIE is available.Ion measurementsMonovalent ions play a major role in volume regulation. Because the properties of fluorescent ion probes depend on the environment, they have to be calibrated in situ. Ionophores are often used to control intracellular milieu; however, equalization of intracellular and extracellular ion concentrations would require the destruction of the membrane potential and a harsh treatment of cells. One way to avoid it is to measure the actual membrane potential y simultaneously with the ion of interest. The process can be presented by the following flow‐chart:Membrane permeabilityApotosis can alter membrane permeability not only for inorganic ions, but for certain organic substances, such as choline. Some of the common cellular stains utilize same pathways and can be used to assess the cell permeability. More work is needed to characterize the channels involved in these processes.Support or Funding InformationThe work was partially funded by KSU Research Council grant
A Lymphedema‐Inducing Mutation of Cx47, R259C, Alters Growth Pattern and Cx43 Processing in Rat Insulinoma Cells
Authors: Kanady John , Pontifex Tasha , Taylor Samantha‐Su , Simon Alexander , Burt Janis 
Published: November 2023

Connexins (Cx), proteins that mediate direct intercellular communication, are essential for normal vascular development and function. Mutations in Cx47 have been reported to underlie cases of lymphedema in humans, however the cellular and molecular mechanisms responsible for dysfunction have been largely unexplored. This study examines an orthologous mutation in mouse Cx47 to one of these lymphedema‐causing mutations, an arginine to cysteine substitution (R259C) in a highly‐conserved region of the second extracellular loop. We transfected connexin‐deficient rat insulinoma (Rin) cells with wild‐type (WT) Cx47 or Cx47R259C either alone or in combination with WT Cx43. Evaluation of cell growth was performed using light microscopy, protein expression through Western blot and immunocytochemistry, and electrical coupling via dual whole‐cell voltage clamp. Expression of Cx47 in Rin cells resulted in plexiform cell growth. Cx47R259C and Cx43/Cx47R259C coexpressing Rin cells also displayed plexiform growth patterns, but exhibited more elongated gaps between cell groups. Surprisingly, in Cx43/Cx47R259C cells a multiple banding pattern for Cx43 was detected via Western blot and full length Cx43 was conspicuously absent. Immunocytochemistry of Cx43/Cx47R259C cells revealed a diffuse cytoplasmic staining pattern for Cx43 and an absence of readily identifiable gap junction plaques. Based on initial electrophysiological recordings, Cx47‐expressing Rin cells have a low incidence of electrical coupling. Together, these preliminary data suggest that Cx47 influences cell growth, and subtle alterations in pattern occur with mutation of Cx47 at R259C. Furthermore, Cx47R259C affects cellular processing of Cx43, which may be a potential molecular mechanism by which this orthologous mutation leads to lymphatic defects in humans.Support or Funding InformationThis work was supported by the following grants: National Institutes of Health (R21HL122443) and Heart, Lung, and Blood Training Grant (T32HL007249)
Exercise Training Attenuates Vascular Smooth Muscle Remodeling of Coronary Microvasculature in Aged Heart
Authors: Hotta Kazuki , Chen Bei , Behnke Bradley J , Ghosh Payal , Alarcon David , Morgan Hannah , Cowan Morgan , Lucero Tiffani , Maraj Joshua , Haynes Anthony , Stabley John N , Delp Michael D , Muller‐Delp Judy M 
Published: November 2023

Late life exercise training reverses age‐induced coronary microvascular dysfunction; however, the cellular mechanisms that underlie this reversal have not been identified. We tested the hypothesis that exercise training attenuates age‐induced vascular smooth muscle remodeling and proliferation, thus contributing to an improvement of microvascular function in coronary arterioles from old rats. Young and old Fischer 344 rats underwent daily exercise training (15 m/min, 15° incline, 1 hr/d, 5 d/wk for 10 wks) or served as sedentary controls. At the end of training, coronary arterioles were isolated, pressurized and fixed, and subsequently cryosectioned to assess vascular smooth muscle cell number and size, and vascular smooth muscle proliferation via immunohistochemistry. Serum samples were obtained to measure circulating adiponectin, an adipokine that promotes vascular smooth muscle differentiation. Immunoblot analysis was performed on pooled arteriolar samples to assess arteriolar protein levels of adenosine monophosphate‐activated kinase (AMPK), a downstream signaling protein of adiponectin receptors, smooth muscle myosin heavy chain isoform I (SMM I), and the synthetic protein, ribosomal protein s6 (rpS6). Aging increased vascular smooth muscle cell size and correspondingly reduced the number of vascular smooth muscle cells per cross‐sectional unit of vascular smooth muscle. Aging increased vascular smooth muscle cell proliferation. Aging decreased circulating adiponectin and reduced the levels of AMPK and SMM I in coronary arterioles; whereas the level of rpS6 increased in arterioles from old rats. After exercise training, the age‐related difference in the number and size of smooth muscle cells was no longer detectable. Exercise training also decreased vascular smooth muscle cell proliferation in arterioles from old rats, and increased circulating adiponectin in both young and old rats. Exercise training increased the level of SMM I in arterioles from old rats. Age‐related differences in the arteriolar levels of AMPK and rpS6 were no longer detectable in coronary arterioles after exercise training. These results indicate that exercise training‐induced reversal of coronary microvascular dysfunction in the aged heart is linked to attenuation of smooth muscle proliferation and hypertrophy. Furthermore, the restorative effect of exercise training on coronary microvascular function may result from adiponectin‐driven changes in the vascular smooth muscle cell phenotype characterized by increased expression of contractile proteins and reduced expression of synthetic proteins.Support or Funding InformationNIH R01 HL077224 and NIH R01 HL90937
Hypertension‐induced impairment in synaptic plasticity and dysregulation of genes involved in synaptic function in the mouse hippocampus: implications for the pathogenesis of vascular cognitive impairment in aging
Authors: Valcarcel‐Ares Marta Noa , Tucsek Zsuzsanna , Tarantini Stefano , Hertelendy Peter , Giles Cory B. , Orock Albert , Sonntag William E , Wren Jonathan D , Csiszar Anna , Deak Ferenc , Ungvari Zoltan 
Published: November 2023

Strong epidemiological and experimental evidence indicate that hypertension predisposes to cognitive decline in the elderly, but the underlying mechanisms remain elusive. Long‐term potentiation (LTP), defined as a long‐lasting increase in synaptic efficacy following high‐frequency stimulation of afferent fibers, is presumed to play an important role in the establishment and storage of memories in the hippocampus. The present study was designed to characterize the effects of hypertension on synaptic plasticity and the expression of genes involved in regulation of synaptic function in the hippocampus. Hypertension was induced in 3 and 24 month old C57BL/6 mice by chronic (4 weeks) infusion of angiotensin II. To determine whether hypertension compromises neuronal mechanisms of learning and memory, extracellular recordings were performed from acute hippocampal slices using multi‐electrode arrays. Field excitatory post‐synaptic potentials (fEPSPs) were invoked through stimulation of the performant path collaterals and obtained from the dentate gyrus area. We found that hypertension was associated with significant decreases in LTP, mimicking the aging phenotype. Synaptic density was decreased by hypertension, an effect that was exacerbated by aging. In aged mice hypertension decreased protein expression of NMDAR1 and NMDAR2A, whereas expression of GLUR1 and GLUR2 were unaffected. Hippocampal mRNA expression of genes involved in synaptic function was assessed using a targeted qPCR array. The hippocampal gene expression signature observed in hypertensive mice (including altered expression of Nptx2, Bdnf, Homer1, Stxbp1 (Munc‐18), Dlg4) provides important clues for subsequent studies to elucidate the mechanisms by which hypertension may contribute to the pathogenesis and clinical manifestation of both vascular cognitive impairment (VCI) and Alzheimer's disease.Support or Funding InformationThis work was supported by grants from the American Heart Association, the National Center for Complementary and Alternative Medicine, and the National Institute on Aging
Coronary Microvascular Smooth Muscle‐Endothelial Cell Communication and Notch 3 Signaling in Type 2 Diabetes
Authors: McCallinhart Patricia E. , Clark Olivia E. , Kanai Mariko , Lilly Brenda , Trask Aaron J. 
Published: November 2023

The Notch signaling pathway, via cell‐cell communication, is critical during normal vascular development and homeostasis, and it is known to regulate vascular smooth muscle (VSMC) phenotype, including proliferation. The current study tested the hypothesis that VSMC‐endothelial cell (EC) Notch 3/Jagged 1 signaling is aberrant to account for adverse remodeling and stiffness observed in type 2 diabetic coronary resistance microvessels (CRMs). Low‐passage primary coronary VMSCs were isolated from normal and type 2 diabetic db/db mice and were either mono‐ or co‐cultured with normal or type 2 diabetic human coronary microvascular endothelial cells (hCMECs), respectively (n=4–6 per group). In separate experiments, normal (n=3) and diabetic db/db CRMs (n=3) were isolated, mounted, and perfusion pressure fixed on a pressure myograph. The size and frequency of fenestrae in the internal elastic laminas of intact CRMs were assessed using Alexa Fluor 633 hydrazide on a confocal microscope. Coronary VSMCs isolated from db/db mice expressed higher Notch 3 mRNA (2.12±0.10 vs. 1.00±0.20; p<0.01) compared to normal. Co‐culture of coronary VSCMs with hCMECs caused a robust induction of Notch 3 expression in normal VSMCs (3.67±0.60 vs. 1.00, p<0.001), which was exacerbated in coronary VSMCs isolated from db/db mice (5.52±0.51 vs. 3.67±0.60, p<0.05). Alpha‐smooth muscle actin (α‐SMA) trended lower in db/db coronary VSMCs (p=0.07), while co‐culture with hCMECs did not alter α‐SMA expression. Diabetic hCMECs expressed lower Jagged 1 mRNA compared to normal (0.58±0.04 vs. 1.00±0.07; p<0.01); co‐culture of hCMECs and coronary VSMCs caused a robust reduction in Jagged 1 expression in normal cells (0.63±0.06 vs. 1.00±0.07, p<0.001), while no further reduction was observed in co‐cultured diabetic cells. The number of fenestrae in the internal elastic lamina was reduced in diabetic CRMs (0.028±0.005 vs. 0.040±0.001 fen/μm2, p<0.05), while the size of the fenestrae remained unchanged. These data show that Notch3/Jagged 1 expression and VSMC differentiation are altered in diabetic coronary resistance microvessel cells, and VSMC‐EC contact via co‐culture induces differential dysregulation of Notch3/Jagged1 signaling. The data further show a reduction in the number of fenestrae in db/db CRMs, suggesting that the opportunity for Notch3/Jagged1 signaling to occur in vivo may be reduced to contribute to adverse remodeling and stiffness observed in those blood vessels.Support or Funding InformationAHA 15UFEL22760002 to MK; NIH K99HL116769 and NCH to AJT.
Myocardium From the Left and Right Ventricles of Human Hearts Have Similar Mechanical Properties
Authors: Blair Cheavar A , Guglin Maya , Stromberg Arnold , Campbell Kenneth S 
Published: November 2023

The left and right ventricles (LV and RV) of human hearts generate different pressures. It is not clear if this difference in pressure reflects the arrangement of cells in each ventricle, or the force generating capacity of individual myocytes. Thus, the aim of this study is to test the hypothesis that cells from the RV and LV of human hearts have different mechanical properties. Chemically permeabilized multicellular preparations from both ventricles of explanted hearts from patients with heart failure (n=12) and patients without a history of heart failure (non‐failing samples) (n=6) were attached between a force transducer and a motor to determine mechanical properties. Similar to prior data from our laboratory, heart failure reduced isometric force and maximum power by ~40% (p<0.001) and ~30% (p=0.004) respectively. Heart failure also increased pCa50 from ~5.41 to ~5.55 (p=0.006). None of these properties differed between the LV and the RV samples (all p‐values > 0.05). There were no significant interactions between heart failure status and region. These data imply that myocardium from the left and right ventricles has comparable mechanical properties and that heart failure impacts both ventricles in a similar way. Interventricular differences in chamber function are most likely to reflect structural effects as opposed to the intrinsic contractile properties of the cells.Support or Funding Information

NIH
8UL1TR000117‐02

NIH
P30GM110787

AHA
15GRNT25460003

NSF 153854
Improvement of coronary flow and cardiac function, as a function of deletion/downregulation of soluble epoxide sydrolase
Authors: Qin Jun , Kandhi Sharath , Froogh Ghezal , Jiang Houli , Sun Dong , Huang An 
Published: November 2023

To test the hypothesis that increased epoxyeicosatrienoic acids (EETs) bioavailability via the deletion of soluble epoxide hydrolase (sEH) gene improves coronary perfusion in a sex‐different manner, hearts were isolated from male (M) and female (F) wild type (WT) and sEH knockout (KO) mice and perfused with constant flow at different pre‐loads. Hearts isolated from F‐WT and F‐KO mice required significantly higher basal coronary flow to maintain the perfusion pressure at 100 mmHg than their male counterparts, suggesting a reduced basal coronary resistance in females. Increases in pre‐loads initiated a greater reduction in coronary resistance, associated with greater cardiac contraction (developed tension) in F‐WT compared to M‐WT mice. These changes became more dramatic in both sexes of sEH‐KO mice, with more predominant in F‐KO mice. Similarly, increases in cardiac work elicited greater reduction of coronary resistance in both sexes of sEH‐KO than their WT controls in a female‐favorable manner. Cardiac expression of sEH was dwonregulated in F‐WT mice, and coincided with higher cardiac EET levels in F‐WT, as well as M‐KO and F‐KO mice. Thus, the elevation of cardiac EETs, as a function of deletion or female‐specific downregulation of sEH gene, contributes significantly to increases in coronary flow and improvement of cardiac function.Support or Funding InformationThis work was supported by grant HL070653
Only Two Weeks of Physical Inactivity Induces Insulin Resistance and Impairs Glycemic Control in Older Adults
Authors: McGlory Chris , von Allmen Mark , Stokes Tanner , Phillips Stuart 
Published: November 2023

Periods of physical inactivity are known to result in deleterious consequences for skeletal muscle mass, strength, and insulin sensitivity. We propose that even transient periods of reduced activity likely have a greater impact in older individuals who often fail to fully recover. We aimed to examine the impact of two weeks of step reduction (SR), as a model of physical inactivity akin to that occurring during illness, on indices of glycemic control and muscle strength in thirteen healthy older adults (7 men, 6 women, 68 ± 3yr [all data mean±SD]). Participants underwent 7 d of monitored normal activity (pre‐SR) immediately before reducing their daily step‐count from 7379 ± 3809 to 967 ± 79 steps.d−1 for 14 d (SR), and then returning to their habitual step count for a period of 14 d (post‐SR). The HOMA‐IR and MATSUDA models of insulin resistance, and insulin sensitivity as well as glucose and insulin area under the curve GAUC and IAUC in response to an oral glucose tolerance test were assessed pre‐SR, SR, and post‐SR. Peak isometric maximal voluntary contraction (ISO‐MVCpeak), peak rate of torque development (RTDpeak) number of sit‐to‐stand cycles in 30 s, and total distance walked in 6 min were also assessed at these time points. HOMA‐IR increased from pre‐SR to SR (2.8 ± 0.3 to 3.6 ± 0.6, p<0.05) and MATSUDA decreased (3.7 ± 0.5 to 3.0 ± 0.1, p < 0.05), neither recovered at post‐SR. GAUC was not significantly different between pre‐SR (435 ± 121) and SR (467 ± 136) but was marginally lower at post‐SR (386 ± 140, p=0.05). IAUC increased from pre‐SR to SR (3796 ± 579 to 4329 ± 833, p<0.05) and, was still elevated at post‐SR (4051 ± 768, p<0.05). There was no change from pre‐SR to SR in either ISO‐MVCpeak (146 ± 34 to 148 ± 41 N.m, p>0.05), RTDpeak (2142 ± 1527 to 1956 ± 894 N.m.s−1, p>0.05), sit‐to‐stand cycles in 30 s (17 ± 5 to 16 ± 5, p>0.05) or total distance walked in 6 min (561 ± 108 to 563 ± 110 m, p>0.05). These data indicate that two weeks of SR negatively impacts indices of glycemic control in older adults that are not fully recovered after 14 d of return to habitual step count. However, indices of muscle function remained unaltered.Support or Funding InformationSupported by the Canadian Diabetes Association