bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sympathetic transduction of blood pressure during graded lower body negative pressure
Authors: Nardone Massimo , Katerberg Carlin , Teixeira André L. , Millar Philip J. 
Published: May 2022

IntroductionCross‐sectional work has demonstrated that participants with high resting muscle sympathetic nerve activity (MSNA) have lower resting sympathetic transduction of blood pressure (BP), and a larger proportion of sympathetic bursts firing above the BP set‐point (or mean BP). However, to date, most of these observations have been evaluated between participants with different levels of resting MSNA. The objective of the current study is to evaluate the influence of acute elevations in MSNA on sympathetic transduction of BP in young healthy adults using graded lower body negative pressure (LBNP). We hypothesize that sympathetic transduction will decrease during acute elevations in MSNA due to an increased proportion of MSNA bursts firing above the BP set‐point.MethodsTen (1 female) young healthy participants underwent 8 minutes of quiet rest, followed by a graded LBNP protocol consisting of 8‐minute stages at ‐10, ‐20, and ‐30mmHg. Beat‐to‐beat heart rate and BP were quantified using single‐lead electrocardiography and finger photoplethysmography, respectively, while MSNA was quantified using fibular nerve microneurography. Sympathetic transduction was quantified in the time (signal‐averaging) and frequency (MSNA‐diastolic BP low frequency [LF: 0.04‐0.15 Hz] transfer function magnitude) domains. Tertiles of diastolic BP were determined for each participant, and the proportion of MSNA bursts firings within each BP tertile were quantified.ResultsMSNA burst frequency increased progressively during graded LBNP (from 15±7 to 17±7, 22±7, and 27±9 bursts/min; P<0.01), while the proportion of MSNA bursts firing in the highest BP tertile remained stable (19±7, 18±9, 19±9, 19±7 %; P=0.72). Sympathetic transduction of BP was unchanged during LBNP (from 2.1±1.1 to 2.3±1.5, 2.1±1.2, and 2.0±1.1 mmHg; P=0.51), while the BP responses to non‐burst cardiac cycles decreased progressively (from ‐0.7±0.5 to ‐0.9±0.5, ‐1.0±0.4, and ‐1.4±0.7 mmHg; P<0.01). The difference between burst and non‐burst cardiac cycles (from 2.8±1.4 to 3.2±1.9, 3.1±1.5, and 3.4±1.3 mmHg; P=0.26) and the MSNA‐diastolic BP transfer function magnitude (from 0.14±0.09 to 0.14±0.06, 0.14±0.06, and 0.13±0.07 au/mmHg; P=0.40) were also unchanged during LBNP. Lastly, the change in the proportion of MSNA bursts firing in the largest BP tertile was associated with the change in signal‐averaged sympathetic transduction across each stage of LBNP (r= ‐0.79, ‐0.78, ‐0.81; P≤0.01).ConclusionSympathetic transduction of diastolic BP is unchanged during graded LBNP due to the heterogenous inter‐individual responses in the gating of bursts to diastolic BP. The proportion of bursts firing at high BPs are associated with changes in sympathetic transduction of BP. The determinants of gating MSNA burst occurrence by the arterial baroreflex and its capacity for modulation warrant further study.
AKAP‐mediated regulation of extracellular matrix secretion in cardiac fibrosis
Authors: Paterek Aleksandra , Delaunay Marion , Kaiser Simon , Gautschi Ivan , Diviani Dario 
Published: May 2022

Cardiac fibroblasts represent the most abundant cell type in the myocardium and provide structural support through controlled proliferation and extracellular matrix (ECM) turnover. In response to chronic pressure overload, quiescent resident cardiac fibroblasts undergo transdifferentiation to myofibroblasts. These activated fibroblasts display increased ECM synthetic capacity and secrete large amounts of collagens. Excessive deposition of ECM results in massive interstitial fibrosis, which decreases myocardial compliance and affects electrical coupling between cardiomyocytes, causing diastolic dysfunctions and arrhythmias. In this context, deciphering the molecular mechanisms favouring increased ECM secretion and deposition in stressed hearts might be the key for the development of targeted approaches inhibiting excessive myocardial fibrosis and dysfunction.A‐kinase anchoring proteins (AKAPs) are molecular scaffolds that act as signal organizers. By recruiting and coordinating the activity of signalling enzymes in space and time they control physiological and pathological responses in cardiac cells. In this respect, our current findings suggest that AKAPs directly regulate the activity of the pathway that controls intracellular ECM protein transport and secretion in myofibroblasts. We are currently evaluating the use of molecular disruptors of selected AKAP complexes to reduce collagen secretion. These disruptors will be tested for their ability to prevent fibrosis and myocardial dysfunction in response to pressure overload.
Glial cell‐Derived, but Not Neuron‐Derived, Extracellular Vesicles May Serve as Novel Biomarkers of Acute Sport‐Related Concussion
Authors: Rath Meghan , Sayoc Jacqueline , Burns Karlee , McDevitt Jane , Fan Xiaoxuan , Tierney Ryan , Wu Jingwei , Park Joon Y. 
Published: May 2022

Extracellular vesicles (EVs) are released by cells of the central nervous system as a result of injury, including sport‐related concussion (SRC). Neurons, astrocytes, and oligodendrocytes have been shown to release EVs following brain injury and during pathological processes. The OBJECTIVE of this study was to evaluate circulating glial cell‐derived and neuronal‐derived EVs as novel biomarkers for acute SRC.METHODSCirculating EVs containing astrocyte‐specific glial fibrillary acidic protein (GFAP+EV), oligodendrocyte‐specific myelin oligodendrocyte glycoprotein (MOG+EV), and neuron specific enolase (NSE+EV) were analyzed in contact‐sport athletes with or without SRC (18‐29 yo, Control: n = 10, SRC: n = 7). Sodium citrate‐treated blood samples were obtained from athletes with SRC within 48‐hours of injury and from control athletes free of SRC for more than one year. Samples were double‐centrifuged to obtain platelet‐poor plasma and stored at ‐80°C until analyzed. Quantification of EVs was performed using a spectral flow cytometer. The study was approved by Temple University’s IRB, and all athletes provided written informed consent. Shapiro‐Wilk tests were used to determine if concentrations were normally distributed. Independent t‐tests were used to compare group means if samples showed normal distribution. Mann‐Whitney U tests were conducted if samples were not normally distributed. For correlational analysis, Pearson’s correlational coefficient was used for samples with normal distribution, while Spearman’s rank was used for nonnormally distributed samples. The Eta coefficient was used to assess correlations between gender and EV concentrations.RESULTSWe found that plasma concentrations of GFAP+EVs and MOG+EVs were significantly elevated in athletes with SRC within 48 hours of injury (GFAP+EVs t‐test: t = 5.77, p < 0.0001; MOG+EVs Mann‐Whitney U = 2.00, p = 0.0004) compared to athlete controls. Plasma concentrations of NSE+EVs were not significantly different between athletes with acute SRC and athlete controls (t‐test: t = 0.20, p = 0.85). None of the EV concentrations were significantly correlated with history of prior SRC, age, or gender.CONCLUSION. Glial cell‐derived EV concentrations were significantly higher among athletes with acute SRC compared to controls, while neuron‐derived EVs did not differ. Our results suggest that analysis of brain cell‐specific EVs may shed new light on a way to leverage EV‐based biomarker discovery for SRC.
The scaffold protein Shoc2 controls ERK1/2‐driven neural crest development by balancing the expression of extracellular matrix components
Authors: Norcross Rebecca G. , Abdelmoti Lina , Landestoy Daileen , Tussey Olivia , Galperin Emilia 
Published: May 2022

Dysregulation of the extracellular‐signal‐regulated kinase 1/2 (ERK1/2) pathway results in common developmental syndromes – RASopathies. Our lab studies a RASopathy called Noonan syndrome with loose anagen hair (NSLAH). This RASopathy is caused by mutations in a critical regulator of the ERK1/2 pathway, Shoc2. Patients harboring shoc2mutations have structural deficiencies common among RASopathies (e.g., altered pigmentation, craniofacial defects, valve disorders). Many NSLAH features could involve defects in the development of neural crest (NC).Zebrafish provide an excellent system for studying neural crest development because of their transparency and highly conserved molecular pathways. Therefore, we utilized the zebrafish model to study the role of Shoc2‐mediated signals in NC development. We found that the loss of Shoc2 affects the expression of the transcription factors prdm1a, pax7, and foxd3‐ all required for the neural plate border formation in zebrafish. The loss of Shoc2 also led to the irregular expression of sox10, the global regulator of NC formation. Moreover, embryos depleted of Shoc2 displayed altered expression of dlx2a, a key transcription factor for the maintenance of cranial NCCs and their migration. We observed that loss of Shoc2 impaired the expression of the transcription factor inducing commitment to cartilage fate, promoting the activation of cartilage‐specific genes in the forebrain and the pharyngeal arch regions, and regulating chondrocyte stacking, sox9a. Moreover, the loss of the Shoc2‐ERK1/2 axis hindered the terminal differentiation of NCCs and resulted in the reduced number of NCC‐derived Schwann cells and pigment cells, including iridophores. Finally, our global assessment of the transcription programs affected by the loss of the Shoc2‐ERK1/2 signals revealed striking differences in the expression of a significant number of extracellular matrix proteins and proteoglycans, including collagen2aI, and aggrecans a and b ‐ all of which are critical for chondrocyte differentiation and maturation.Together, our data suggest that the Shoc2‐ERK1/2 signaling axis is critical for the development, specification/differentiation, and morphogenesis of the NC‐derived tissues. Our study is the first to define that Shoc2‐mediated ERK1/2 signals regulate NC development. Future inquiries into the mechanisms by which Shoc2 controls embryogenesis will significantly advance our understanding of the mechanisms underlying pathological causes of NSLAH and, ultimately, other RASopathies.
Uterine Fibroids ‐ Why Aren't We Talking About Them?
Authors: Wallace Kedra , Bouldin Sheila 
Published: May 2022

ProblemUterine fibroids (UFs) are smooth muscle tumors that are located in the uterus. Even though these tumors are mostly benign, they are the most common gynecological disorder; estimated to affect 70‐80% of women by the age of 50. Black women are disproportionately affected by UFs as UFs appear earlier in black women, the symptoms are often more severe and black women often wait longer to receive treatment and have more surgical complications relative to non‐black women. The epidemiology for UFs is unclear, however being of black race, hypertensive, obese, and pre‐menopausal increases the risk of developing UFs.DataData from the COMPARE‐UF (Comparing Options for Management: Patient‐centered Results for UF) multi‐site observational registry indicated that black women with UFs who received hysterectomy’s (uterus removal) for treatment had a lower health related quality of life (HRQoL) compared to white women receiving the same procedure. In a separate analysis from this same population we also published data indicating that black women with UFs were more likely to have a surgery that was not a hysterectomy, unless they were treated in Mississippi (MS). We have previously published data from patients treated for UFs in MS and have reported that relative to women with abnormal uterine bleeding but no UF’s, women with UFs had significantly more hypertension but no change in body mass index. We also reported that circulating factors associated with hypertension (ET‐1 and sFlt‐1) were significantly increased among women with UF's relative to women with abnormal uterine bleeding.RationaleAs MS ranks among the highest in the nation for hypertension, and black people per capita the likelihood for an increased prevalence of UFs is high. The combination of these studies and our own studies indicate that black women with UFs who reside in the rural South may be more affected and have lower HRQoL to black women with UFs who live in more urban areas. While the medical and surgical options are limited for UFs, data is beginning to emerge indicating geographical differences that elude to a different problem.Proposed SolutionHere in MS, we have proposed a patient navigator program (EMPOWER‐UF) to help educate women on the different treatment options available and to help women navigate the health care system. It is our belief that the combination of a patient navigator and a patience decision aid, adapted for women with UFs, could increase health literacy and improve the shared decision making process. The combination of these events will lead to an increased satisfaction in decision making regarding UF treatment choice and an increase in HRQoL.
19F‐NMR shows that active site aromatic residues in CYP121 of Mycobacterial tuberculosisplay a dual role in substrate interaction and protein structure
Authors: Campomizzi Christopher S. , Estrada D. Fernando F. 
Published: May 2022

CYP121 is an essential cytochrome P450 enzyme (CYP) from Mycobacterium tuberculosis.CYP121 mediates an atypical phenol‐coupling reaction that converts cyclodityrosine (cYY) into mycocylosin. Our lab has previously employed a 19F nuclear magnetic resonance (NMR) label, 3‐bromo‐1,1,1‐trifluoroacetone (BTFA), to study dynamics of the FG‐loop, a region connecting the F and G‐helices. In other CYPs, the FG‐loop region has been implicated in active site access and substrate recognition. The 19F‐NMR spectrum for the FG‐loop in CYP121 is heterogeneous, suggesting that in solution there are multiple conformations. Upon titration of cYY, the signal converges to a single peak representing a bound state. Interestingly, this labeling site exists approximately 20 angstroms away from the active site heme, where ligand binding is typically measured in CYPs by UV‐visible spectroscopy. Crystal structures show an invariable protein structure with ligands clustered near the FG‐helices, away from the heme.Here we investigate the specificity of this interaction site by expanding our use of 19F labeling. Supplementing cells with 5‐fluoroindole (5‐FI) during recombinant protein expression, 19F was incorporated into each tryptophan residue of CYP121. This method of labeling allowed for four tryptophan residues to be monitored, which span the entire protein structure. Notably, two residues, Trp‐182 and Trp‐380, are located adjacent to the CYP121 homodimer interface. The 19F‐NMR spectrum contains three distinct signals, two of which are equal in intensity, and a third which has been determined to be two overlapping resonances. Addition of cYY causes a shift of equilibrium in the spectra, with the overlapped resonances resolving and resulting in four peaks of roughly equal area and intensity. These results suggest that only the active site residue Trp‐182 is affected by the addition of cYY. Using this labeling scheme, we also tested alanine substitutions of Trp‐182 and another active site aromatic residue, Phe‐168. 19F‐NMR spectra from these mutants indicate a general perturbation of the structure, with only one Trp residue left unaffected. Since Trp‐182 extends into a hydrophobic pocket of CYP121 (suggesting a structural role), additional substitutions were made using tyrosine and leucine side chains. The conservative W182Y mutant yielded similar disorder as seen when replaced with alanine, while W182L results a partially restored spectrum. Interestingly, both mutants bind substrate in a similar manner as wild‐type when measured by UV‐visible spectroscopy, although with weakened affinity.These findings indicate that while Phe‐168 and Trp‐182 are involved in substrate interaction, they also play a role in the fold of the protein, with mutagenesis causing long range changes in structure.
Microautophagy catabolizes lipid droplets in liver hepatocytes via the small GTPase Rab5 and is connected to alcoholic fatty liver
Authors: Rozeveld Cody N. , Mehall Bridget , Casey Carol , McNiven Mark , Schott Micah 
Published: May 2022

Introduction and ObjectiveAlcohol consumption has increased dramatically in recent years, representing a significant challenge to human health in metabolic disease. The leading cause of alcohol‐related death is alcohol‐associated liver disease (AALD), which is present at early stages (i.e. steatosis) in 90% of heavy drinkers. During early AALD, liver hepatocytes accumulate large stores of triglycerides in the form of lipid droplets (LDs). Under normal conditions, degradative lysosomes form direct contacts with LDs and catabolize lipid via microlipophagy, a specialized autophagic pathway utilizing the lipid‐degrading enzyme lysosomal acid lipase (LAL). However, the trafficking mechanisms that govern LD‐lysosome contacts during microlipophagy are poorly understood. Several promising candidates exist within the Rab family of small GTPases, which are well‐known to direct the trafficking of intracellular vesicles and LDs. Moreover, previous studies suggest that Rab proteins play central roles in LD catabolism. Thus, the OBJECTIVE of this study was to investigate novel Rab proteins that might be impaired by EtOH leading to altered LD dynamics and microautophagy.Materials and MethodsTo this end, we utilized RNAi gene silencing, subcellular fractionation, Western blot analysis, and high‐resolution microscopy to define Rabs that might target LDs to lysosomes during microlipophagy. To mimic alcoholic fatty liver, cellular and animal models of alcohol consumption were also used. Changes in LD‐lysosome interaction were measured by quantitative confocal microscopy following pharmacological inhibition of LAL by LAListat.ResultsFirst, confocal microscopy revealed that GFP‐Rab5, an early endosomal Rab GTPase, localizes to hepatocellular LDs consistent with proteomic and Western blot analyses showing abundant levels of Rab5 in biochemically isolated LDs. Importantly, siRNA knockdown of Rab5 in cultured hepatocytes showed substantial increases in total LD area (2‐fold) and LD number (1.6‐fold), and also blocked the catabolism of LDs in lipid‐loaded cells. Finally, Rab5 knockdown nearly completely abolished microlipophagy as measured by fluorescent LD accumulation in lysosomes following LAListat treatment. The dissociation of LDs from lysosomes in Rab5 knockdown cells was strikingly similar to the defect observed in EtOH‐fed hepatocytes. Together, these findings suggest that Rab5 is a key mediator of targeting LDs to the lysosome compartment for catabolism and may be a target of EtOH insult.Significance/ImplicationThis study sheds light on new molecular mechanisms of microlipophagy that are affected by chronic alcohol consumption. These mechanisms may represent promising avenues for future therapeutic development toward mitigating hepatic steatosis and slowing the progression of AALD.
Experience in the application of remote anesthesia in Callorhinus ursinus
Authors: Nikitina Anastasia , Gaponova Viktoriya , Bukina Lidiya , Trushkin Vyacheslav , Burkanov Vladimir 
Published: May 2022

Marine mammals often become entangled in various objects of anthropogenic origin floating on the surface of the water. Plastic, polyethylene, synthetic packing straps, and fishing gear threaten marine mammals in the water and on land. The study was carried out on 29 specimens of Callorhinus ursinus. We used a combined Zoletil 100 and Medetin 1% for remote sedation of injured Callorhinus ursinus to release foreign objects.Resultsthe first signs of anesthesia were recorded 3‐5 minutes after drug delivery. The difficulty of movement, coordination disorder, weakness were noted. After 5‐15 minutes, the animals lay down but reacted to touch, and their eyes were open. After 15‐20 minutes, the animals lay motionless, practically not reacting to external stimuli. Their eyes were in a half‐closed state. In this state, it is possible to carry out manipulations to remove foreign objects from the animal. The depth of narcotic sleep varied depending on the dose: mild sedation developed at Medetin 1% 0.02‐0.03 mg/kg and Zoletil 100 0.45‐0.65 mg/kg. The animals were lying down, we could approach them, but they reacted to touches and loud sounds. The eyes were open, and it was dangerous to carry out any manipulations with such animals. The seals did not fall into a deep sleep; after 30‐60 minutes without the use of antagonists, they began to move, but there was a slight impairment of coordination of movements for 1‐2 hours. Moderate sedation was observed at a dose of 0.03‐0.05 mg / kg Medetin 1% and 0.5‐0.9 mg / kg Zoletil 100. The animals lay motionless; sometimes, there was a slight twitching of their fins, whiskers, or ears during manipulation of slight pain. Eyes half‐closed. It is possible to carry out small short‐term manipulations with the animal to remove a foreign object without strong painful sensations. After 30‐60 minutes, the seals wiggled their flippers and tried to raise their heads. They began to move independently after 1‐1.5 hours. Slight impairment of coordination was noted 1.5‐2 hours after full awakening. At a dose of 0.05‐0.09 mg/kg Medetin 1% and 0.8‐2.0 mg/kg Zoletil 100, the animals lay motionless and did not react to external stimuli, even during painful manipulations or movement. This sedation is deep, suitable for painful procedures to remove foreign objects with deep skin lesions. Without the use of antagonists, such animals woke up after 1‐1.5 hours. They began to move their flippers, mustache, move around after 2.5‐3 hours. Determining the optimal doses of drugs for remote anesthesia of marine mammals is essential, both for the safe release of foreign objects from the animals and also for the people who perform this work.
Carotenoids in Orange Carrots Mitigate Against Non‐alcoholic Fatty Liver Disease Progression
Authors: Balbuena Emilio , Cheng Junrui , Eroglu Abdulkerim 
Published: May 2022

BackgroundCarotenoids are naturally occurring compounds found in brightly colored fruits and vegetables. Increased consumption of these dietary sources may alleviate the harmful effects of the high‐fat diet. They can be used as co‐adjuvant against metabolic syndrome (MetS). Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of MetS characterized by the extensive lipid deposition in the liver tissue without significant alcohol intake. Mechanistically, NAFLD results from imbalanced hepatic lipid homeostasis stemming from elevated hepatic triglyceride (TG) uptake, upregulated fatty acid (FA) synthesis, or decreased β‐oxidation.ObjectiveThe purpose of the study was to illustrate the impact of carotenoid‐rich whole foods on obesity‐associated NAFLD progression.MethodsMale C57BL/6J mice (n = 48) were randomized to one of four experimental diets for 15 weeks (n=12 animals/diet): Low‐fat diet (LFD, 10% calories from fat), high‐fat diet (HFD, 60% calories from fat), HFD with 20% white carrot powders (HFD+WC), and HFD with 20% orange carrot powders (HFD+OC). The concentrations of α‐carotene and β‐carotene in carrot powders, diet pellets, serum, liver, and feces were detected by analytical assays. Tissue histology and TG content analysis were used to depict the extent of hepatic steatosis. Western blot and qPCR were utilized to observe trends of fatty synthesis and β‐oxidation.ResultsThe HFD+OC group reduced weight gain significantly compared to the HFD group and efficiently decreased hepatic lipid accumulation based on the histological and TG analysis. We observed minimal down‐regulation of FA synthesis proteins in the HFD+OC group as depicted by Western blot and qPCR. On the other hand, the HFD+OC treatment significantly enhanced β‐oxidation proteins, possibly by promoting master regulators of hepatic lipid metabolism (i.e., p‐AMPK, PGC‐1α, PPARα).ConclusionsCarotenoids in orange carrots may decrease the severity of hepatic steatosis in NAFLD by partial inhibition of fatty acid synthesis and increased activity of β‐oxidation.