bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exogenous Ubiquitin Improves Cardiac Function and Reduces Inflammatory Response Following Myocardial Ischemia/Reperfusion Injury
Authors: Scofield Stephanie L.C. , Lim Kristina A. , Dalal Suman , Singh Mahipal , Singh Krishna 
Published: November 2023

Ischemia/reperfusion (I/R) model represents a clinically relevant animal model to parallel the inflammatory and remodeling response associated with myocardial infarction. Ubiquitin (UB) is a small molecular weight protein best known for its role in the proteasomal degradation of damaged proteins. Previously, our lab demonstrated that sympathetic stimulation increases extracellular levels of UB independent of necrosis, and extracellular UB ameliorates the adverse effects of chronic sympathetic stimulation, namely: increases in workload, function and myocyte apoptosis. Here we tested the hypothesis that extracellular UB decreases inflammatory response in the heart, thereby playing a protective role in myocardial ischemia/reperfusion injury. This study used 8–12 week male C57Bl/6 mice. One day prior to ischemia/reperfusion injury, mice were infused with vehicle (saline) or UB (1μg/g/h) using micro‐osmotic pumps which osmotically released UB over 3 days. The hearts were subject to ischemia for 45 min followed by reperfusion for 3 days. Heart function was assessed by m‐mode echocardiography and measured in terms of percent fractional shortening (%FS) and ejection fraction (%EF). Infarct size was determined using Masson's trichrome staining of heart sections. Inflammatory response was measured using hematoxylin and eosin (H&E) staining, and by immunohistochemical staining using anti‐neutrophil and anti‐F4/80 (macrophage) antibodies. Infarct size was significantly smaller in UB‐infused group (% of LV infarcted; Vehicle‐I/R, 26.7±4.4; UB‐I/R, 13.0±2.7*; *P<0.05 vs Vehicle‐I/R; n=5). Echocardiographic analyses showed that I/R decreases heart function as measured by decreased %FS and %EF versus sham. UB treatment significantly improved %FS (Sham, 37.9±2.8; UB, 34.9±1.3; Vehicle‐I/R, 28.3±1.1*; UB‐I/R, 33.0±1.8$; *p<0.05 vs Sham $p<0.05 vs Vehicle‐I/R; n=6–7) and %EF (Sham, 68.5±3.6; UB, 64.9±3.6; Vehicle‐I/R, 55.6±1.8*; UB‐I/R, 62.4±2.6$; *p<0.05 vs Sham $p<0.05 vs Vehicle‐I/R; n=6–7) when compared to Vehicle‐I/R group. H&E staining showed a significant decrease in inflammatory cells in UB‐I/R group (total infiltrates per 0.1mm2; Vehicle‐I/R, 106.6±15.9; UB‐I/R, 46.5±6.8*; *p<0.05 vs Vehicle‐I/R; n=3). Likewise, the number of neutrophils and macrophages was significantly lower in UB‐infused hearts following I/R injury. These data suggest that exogenous UB decreases infarct size, improves heart function and decreases inflammatory response following I/R injury. Thus, exogenous UB plays a protective role in myocardial I/R injury, possibly by limiting the extent of inflammatory response.Support or Funding InformationSupported by Department of Veterans Affairs (BX002332), NIH R15HL129140 (NHLBI) and Institutional Research and Improvement account.
SIRT1 Activator II Protects against Myocardial Injury in High Fat Diet‐Induced Diabetic Mice
Authors: Boini Krishna M , Raghunathan Suchi , McConnell Bradley , Koka Saisudha 
Published: November 2023

Cardiovascular diseases are a leading cause of death and disability in diabetic patients. Recent studies suggest that switching gears towards survival and longevity factors such as sirtuins induce protection against cardiovascular complications in diabetic patients. The present study investigated the effect of SIRT1 activator II on myocardial injury in high fat diet‐induced type 2 diabetic mice. Adult C57BL/6J mice (n=16/group) were fed a normal chow diet (ND‐10 Kcal % fat) or high‐fat diet (HFD‐60 Kcal % fat) for 6 months. Body weights and blood glucose levels were monitored. Glucose tolerance tests were performed after dietary intervention to confirm the development of type 2 diabetes. A subset of HFD mice were treated with SIRT1 Activator II for 4 weeks. Plasma was collected from mice to measure plasma glucose, insulin and lipid parameters such as total cholesterol, HDL and LDL/vLDL. Subsequently mice hearts were isolated and subjected to 20 min ischemia and 40 min reperfusion (I/R). SIRT1 Activator II treatment significantly reduced the body weight (42.5±1.1 g vs 50.9±1.5 g; p<0.05), fasting plasma glucose levels (210.1±24.6 mg/dl vs 354.7±19.7 mg/dl; p<0.05) and insulin (3.97±1.45 ng/ml vs 12.11±2.01 ng/ml; p<0.02) compared to untreated HFD group. SIRT1 activator II treatment improved the lipid profile in HFD mice. Functional recovery after I/R in the ex vivo Langendorff perfusion model was significantly lower in HFD fed mice than ND fed mice. SIRT1 activator II treated mouse hearts demonstrated better cardiac function recovery and had significant reduction of the necrotic markers creatine kinase and lactate dehydrogenase. SIRT1 activator II significantly reduced the infarct size (22.08±2.2% vs 35.418±3.79% p<0.01) in HFD fed mice following I/R injury. Additionally, SIRT1 Activator II treatment suppressed expression of proinflammatory cytokines in HFD fed mice. In conclusion, our findings suggest that SIRT1 activator II prevents the detrimental effects of diet‐induced type 2 diabetes and could be a safe therapeutic intervention for ischemic heart diseases in diabetic patients.Support or Funding InformationDK104031
The Role of Cardiac Lineage Protein 1 (CLP1) on Inflammatory and Fibrotic Responses following Myocardial Infarction
Authors: Ghobrial Christine , Salciccioli Louis , Stewart Mark 
Published: November 2023

Cardiovascular disease is one of the leading causes of death worldwide. Atherosclerosis, for example, can contribute to loss of blood supply to the heart, and damage or destroy cardiomyocytes. Sufficient damage leads to heart failure. Cardiomyocyte loss results in a process of remodeling, which includes inflammatory responses that remove debris, followed by fibroblast transdifferentiation to replace muscle tissue. Cardiac lineage protein 1 (CLP1) is a regulatory protein that is involved in directing cardiac development (Huang, et al. Gene. 2002;121(6):559–72). We studied whether CLP1 plays a role in remodeling the heart following permanent left anterior descending artery (LAD) occlusion in mice. Specifically, we sought to determine the role of CLP1 in the development of fibrosis in cardiac tissue, and to changes in the expression activity of Smad3 and NFkB, key transcription factors which are involved in myocardial infarction.All mice were imaged using echocardiography preoperatively and once a week, postoperatively. Wildtype and CLP1+/− mice either underwent sham surgery or LAD occlusion (Gao, et al. Circ Res. 2010;107(12):445–1453). The hearts were harvested at 1 week or at 4 weeks following surgery and were processed for histological analysis of fibrosis or for biochemical and immunohistochemical analysis of inflammatory pathways involved in myocardial infarction.Wildtype and CLP1+/− hearts exhibit cardiac remodeling, as measured by percent of collagen deposition both above and below the ligation. CLP+/− hearts had a lower amount of remodeling both above and below the ligation following ischemic injury compared to wildtype 1 week following permanent LAD occlusion. However, at 4 weeks following ischemic damage, there was a significantly greater amount of remodeling in the CLP1+/− mice compared to wildtype mice both above and below the ligature. Immunofluorescence staining showed increased pSmad3 and pNFkB activation and translocation into the nucleus in the infarcted zone following ischemic damage in both wildtype and in CLP1+/− hearts. Cardiac function in CLP1+/− mice was worse in comparison to the wildtype, as measured by fractional shortening and by ejection fraction both 1 week and 4 weeks following MI. There was not a statistically significant difference in LVmass between CLP1+/− and wildtype mice.Our data suggest that CLP1 limits the remodeling response by possibly delaying the fibrotic phase of myocardial infarction injury. This may result from a prolonged inflammatory period, and a delay in collagen deposition in the infarcted area, thus resulting in a poorer functional recovery after ischemic damage. Limiting the duration of inflammation may result in a better prognosis following myocardial infarction.
Lower Limb Venous Distension Reflex and Orthostatic Tolerance in Young Healthy Humans
Authors: Cui Jian , Blaha Cheryl , Herr Michael D. , Sinoway Lawrence I. 
Published: November 2023

We and others showed that venous distension induced by saline infusion into veins of an arterially occluded arm evokes reflex increases in muscle sympathetic nerve activity (MSNA) and blood pressure (BP) in humans (i.e. venous distension reflex). Our recent report also shows that suction of arterially occluded limb (forearm or lower leg) evokes significant increases in MSNA and BP, which are induced by the vascular distension in the limbs. We postulate that venous distension reflex will be activated when humans stand. We speculate that the individual differences in the venous distension reflex may contribute to the individual differences in the orthostatic tolerance. Thus, we hypothesized that the orthostatic tolerance would be related with the MSNA response to the lower limb suction. Fifteen healthy subjects (8M, 7F, 26 ± 1 yrs, 172 ± 3 cm, 69 ± 4 kg) were tested in supine position. One of the subject's lower legs was inserted into an airtight pressure tank. An arterial occlusion cuff was put on the mid thigh (~10–15 cm above the level of the suction tank). MSNA (in the opposite limb), ECG, and BP (Finometer) were recorded throughout the study. After the arterial occlusion cuff on the mid thigh was inflated (250 mmHg), limb suction (‐100 mmHg) is applied for 2 min. Limb occlusion without suction was used as a control trial. In a separate visit, the individual's orthostatic tolerance was assessed using a graded lower body negative pressure (LBNP) tolerance test (from 20 up to 70 mmHg, no MSNA). Mean arterial BP (MAP, 78.9 ± 1.1 to 86.9 ± 1.7 mmHg) and MSNA (18.5 ± 1.9 to 23.6 ± 2.0 bursts/min) significantly (both P < 0.05) increased during the suction of a leg, while heart rate was not significantly different from the baseline. Occlusion alone did not significantly alter MSNA. The magnitude of the MSNA response to single leg suction at 100 mmHg was then compared to the orthostatic tolerance index for that subject. The orthostatic tolerance index positively correlated (R = 0.636, P = 0.011) with the MSNA response seen with suction during occlusion. The presented data suggest that the venous distension reflex strength correlates with the level of orthostatic tolerance. Thus, we speculate that lower limb venous distension reflex engagement increases the sympathetic responses during orthostatic challenge and serves to maintain BP with postural stress.Support or Funding InformationSupported by American Heart Association Grant 15GRNT24480051 (Cui), National Institutes of Health Grants P01 HL096570 (Sinoway) and UL1 TR000127 (Sinoway).
Presynaptic organization of CaV2 channels with specific vesicle pools in SCG vs rat tail artery
Authors: Kalkhoran Somayeh Mojard , Walia Jag , Gershome Cynthia , Chow Sarah HJ , Poburko Damon 
Published: November 2023

Peripheral sympathetic nerves co‐release multiple neurotransmitters to modulate the activity of their target organ, for example mediating physiological regulation of cardiac contractility and systemic vascular tone. However, the release of “co‐released” transmitters like norepinephrine (NE) and ATP can be differentially regulated, for example by relying on specific isoforms of voltage‐gated Ca2+ channels (CaV), and we previously reported that NE‐ and ATP‐containing vesicles segregate in pools that preferentially co‐localize with specific CaV2 isoforms in rat tail artery. Whether this observation generalizes to other sympathetic nerves is not known, but it is of fundamental importance to understanding the molecular biology of sympathetic co‐release.OBJECTIVETo determine whether specific isoforms of CaV selectively associate with pools of vesicles enriched with transporters for NE or ATP in multiple peripheral sympathetic nerves.METHODSWe performed epifluorescence imaging of intact rat tail artery and cultured superior cervical ganglia (SCG) neurons, comparing the localization and intensity correlation of CaV2.1, CaV2.2, and CaV2.3 with vesicle markers for NE (VMAT2) and ATP (VNUT/SlC17A) containing vesicles or suitable surrogate markers.RESULTSWe confirmed that VMAT2 and VNUT are often but not always found in the same varicosities. While VMAT2 is broadly distributed in varicosity, VNUT localizes as discrete puncta at the perimeter of varicosity and does not co‐localize with synaptagmin1 in SCG neurons, similar rat artery nerves. CaV2.3 and CaV2.1, like VNUT, localize to the periphery of the varicosities, while CaV2.2 more closely mimics to the distribution of VMAT2. These findings mirror our observations in rat tail artery, in which NE release is most sensitive to CaV2.2 inhibition and ATP‐mediated contraction is blocked by CaV2.3 inhibition.CONCLUSIONWe show that synaptic organization of CaV2 isoforms with specific pools of vesicle in a cultured nerve system closely recapitulates that found in vivo. This observation further validates cultured SCG neurons as an experimentally tractable and physiologically revenant model to study presynaptic cell biology relevant to the regulation of both cardiac output and vasoregulation.Support or Funding Information1. Natural Sciences and Engineering Research Council of Canada.2. Canadian Foundation for Innovation
Acute and Chronic Increases in Sodium and Cardiac Vagal Baroreflex Sensitivity
Authors: Babcock Matthew C , Watso Joseph , Brian Michael S , Edwards David G , Stocker Sean D , Wenner Megan M , Farquhar William B 
Published: November 2023

Elevations in serum sodium (sNa+) and plasma osmolality (pOsm) have been shown to increase baroreflex sensitivity. However, the time course of these changes is not clear.PURPOSETo determine whether acute and/or chronic elevations in sNa+ and pOsm alter cardiac baroreflex sensitivity (cBRS) and heart rate variability (HRV).METHODSAn acute increase in sNa+ was achieved with a 23‐minute hypertonic saline infusion (HSI) in 14 subjects (age: 22±1 yrs, BMI: 23±1 kg/m2, 7 men). A chronic increase in sNa+ was achieved with 7 days of a high sodium diet (300 mmol/day) compared to 7 days of a low sodium diet (20 mmol/day; diet order randomized) in 16 subjects (age: 39±4 yrs, BMI: 23±1 kg/m2, 7 men). In the acute and chronic protocols, subjects lay quietly for 5 minutes while undergoing simultaneous measurement of beat‐to‐beat blood pressure (via photoplethysmography) and R‐R interval (via 3‐lead ECG). cBRS was evaluated using the sequence method. Root‐mean‐square of successive differences in R‐R interval (RMSSD) was used as an index of HRV.RESULTSHSI increased sNa+ (137.9±0.4 vs. 140.9±0.5 mEq/L, p<0.05) and pOsm (285±1 vs. 290±1 mOsm/kg H2O, p<0.05). Despite these acute increases, cBRS (26±5 vs. 27±4 ms/mmHg, p=0.73) and RMSSD (63±9 vs. 63±8 ms, p=0.99) were not different. High sodium diet similarly increased sNa+ (137.3±0.6 vs. 140.0±0.4 mEq/L, p<0.05) and pOsm (285±1 vs. 290±1 mOsm/kg H2O, p<0.05). cBRS was significantly increased on the high sodium diet (18±2 vs. 25±3 ms/mmHg, p<0.05), as was RMSSD (61±6 vs. 84±10 ms, p<0.05).CONCLUSIONThese preliminary data suggest that chronic, but not acute, elevations in sNa+ and pOsm are associated with increases in cBRS and HRV.Support or Funding InformationSupported by NIH Grant 1R01HL128388‐01A1
Non‐Invasive 3‐Dimensional Facial Modeling for the Quantification of Facial Edema
Authors: Smith Bridget , Crowell Brent , Ozgur Omar , Goetchuis Elizabeth , Newby Nate , Scott Jessica 
Published: November 2023

BACKGROUNDWith the lengthening of spaceflight mission durations, many crewmembers have experienced in‐flight and/or post‐flight visual and anatomical changes including optic‐disc edema, globe flattening, choroidal folds, and hyperopic shifts. These changes define the visual impairment/intracranial pressure (VIIP) syndrome. Although the underlying mechanism behind VIIP is unknown at this time, it is suspected that the microgravity‐induced cephalad fluid shift plays a significant role. Therefore, quantification of the microgravity‐induced fluid shifts may provide important prognostic information. However, there are limited non‐invasive tools currently available to assess volume changes and facial edema. A standardized method for quantifying the fluid shift and establishing reliability across repeated trials also remains to be clarified. Accordingly, using a commercially available Structure Sensor 3‐dimensional (3D) scanner, our lab developed a protocol to acquire and analyze 3D facial images in seated and supine positions and assessed the validity and reliability of the method. We hypothesized that within day coefficient of variation and across day coefficient of variation would be low (<5%).METHODSVolume measurement validity was assessed by acquiring and analyzing 3D scans of an object with a known volume across three trials. Reliability was assessed in 10 subjects. Structure Sensor 3D scanner (Occipital Inc., San Francisco, CA) images were obtained in two positions: upright and supine on three separate days. Images were immediately viewed on an Apple IPad with ItSeezit3D (ItSeez3D Inc., San Francisco, CA) application to ensure complete scans were obtained. Participants were instructed to look at the same spot each time to ensure constancy across scans. Analysis was completed in Rhinoceros (Robert McNeel & Associates, Seattle, WA, version 5, 64‐bit) software with a standardized technique developed by our lab.RESULTSValidity assessments yielded a mean absolute difference of 1.13 in3 . Average intra‐trial and intra‐day variability (CV) was 2.79%. Upon initial analysis, a cephalic fluid shift was evident in participants in a seated position when compared to the supine position. The mean fluid shift across participants was approximately 600 mL.CONCLUSIONOur findings indicate that the Structure Sensor 3D scanner and accompanying analysis software are valid and reliable tools in the assessment of cephalic fluid shift across different positions. This technology may be useful in identifying inter‐individual differences in cephalic fluid shifts in crewmembers. Future studies should examine the potential applications of this technology in response to a microgravity environment.
Lgr5 Stem Cell‐based organoids in human disease
Authors: Clevers Hans 
Published: November 2023

The intestinal epithelium is the most rapidly self‐renewing tissue in adult mammals. We originally defined Lgr5 as a Wnt target gene, transcribed in colon cancer cells. Two knock‐in alleles revealed exclusive expression of Lgr5 in cycling, columnar cells at the crypt base. Using lineage tracing experiments in adult mice, we found that these Lgr5+ve crypt base columnar cells (CBC) generated all epithelial lineages throughout life, implying that they represent the stem cell of the small intestine and colon. Lgr5 was subsequently found to represent an exquisitely specific and almost ‘generic’ marker for stem cells, including in hair follicles, kidney, liver, mammary gland, inner ear tongue and stomach epithelium.Single sorted Lgr5+ve stem cells can initiate ever‐expanding crypt‐villus organoids, or so called ‘mini‐guts’ in 3D culture. The technology is based on the observation that Lgr5 is the receptor for a potent stem cell growth factor, R‐spondin. Similar 3D cultures systems have been developed for the Lgr5+ve stem cells of human stomach, liver, pancreas, prostate and kidney. Using CRISPR/Cas9 technology, genes can be efficiently modified in organoids of various origins.
Differential Effect of Testosterone Supplements on Body Composition in Young and Old Male Spontaneously Hypertensive Rats
Authors: Maranon Rodrigo Oscar , Dalmasso Carolina , Patil Chetal N , Cardozo Licy L Yanes , Juncos Luis A , Reckelhoff Jane F 
Published: November 2023

The use of testosterone supplements (T) is increasing in the US and is mainly used for conditions such as treatment of hypogonadism, to increase libido, strength, and physical resistance, and to prevent osteoporosis. While clinical and experimental evidence shows that T could improve metabolic parameters in obese men with hypogonadism, T could impair the cardiovascular system leading, for example, to elevated blood pressure. However, these data are controversial. Previously in our lab, we found that T increased blood pressure (BP) in young male spontaneously hypertensive rats (SHR), whereas in old male SHR, T had the opposite effect causing a decrease in BP. We had previously found that T improved metabolic syndrome and caused weight loss with an increase in activity in male obese Zucker rats. Whether T has an effect on body composition in young or old male SHR is unknown. In the present study, we tested the hypothesis that T in young (YSHR) and old (OSHR) male SHR changes body composition mainly by decreasing food intake and body weight. YSHR and OSHR were given testosterone propionate (22 mg/10 mm silastic pellet, sc) or placebo (empty pellets, sc), beginning at 16 weeks and 18 months of age for 6 weeks, respectively. T increased the plasma testosterone (RIA) by +2.5 fold in YSHR and +4 fold in OSHR (p<0.05). T increased plasma estradiol (RIA) by +2 fold in YSHR and 1 fold in OSHR (p<0.05). Tibia lengths were not affected by T in YSHR or OSHR. T reduced food intake in YSHR by 21% compared to YSHR+P (p<0.05), body weight by 8% (p<0.05), total water content by 19% (106±4 vs 87±6, p<0.05), and fat mass by 49% (4.9±0.6 vs 2.5±0.4 % BW, p<0.05), but had no effect on lean mass (p=NS) (all measured by ECHO MRI). Contrary to our hypothesis, while T modestly reduced FI by 12% in OSHR (26±1 vs 23±1 gr, p<0.05), there was no effect on BW, fat mass, total water content, or lean mass after 6 weeks of T supplementation. These data suggest that T supplements in young individuals can modulate body weight and FI and may contribute to an improvement in metabolic parameters. While not addressed in this study, the data also suggest that T supplementation needs to be reevaluated considering the risk for cardiovascular events in aging men who are overweight or obese.Support or Funding InformationSupported by NIH‐R01HL66072, PO1HL51971 (JFR), 14POST18640015 (ROM), EFF Endocrine Res Grant (LLY).