bluuebunny/crossref_metadata_2025 huggingface dataset:
Acquisition of a Senescence‐like Phenotype in Neurons Contributing to the Pathogenesis of Hepatic Encephalopathy Due to Chronic Liver Disease
Authors: Kobs Zachary A. , Williams Elaina , Chu Christopher , Petrescu Anca , An Suyeon , Venter Juliet , DeMorrow Sharon
Published: May 2022

Background

Hepatic encephalopathy resultant from chronic liver failure (Type C HE) is associated with neurological dysfunction and hyperammonemia. In HE, senescent markers have been found in astrocytes, but research into neuronal senescence has been limited. TGFb1 is one of the senescence‐associated secretory phenotype (SASP) factors released from senescent cells, and has been shown to be upregulated in the brain in Type A HE, but its role in Type C HE is unknown. The aim of this study was to assess the role of a senescence‐like phenotype in the pathogenesis of Type C HE.

Methods

SD rats underwent bile duct ligation (BDL) surgery and C57BL/6 mice were treated with CCl4 for 16 wks to induce chronic liver failure. CCl4‐treated mice received a senolytic cocktail of Dasatinib and qercertin (D/Q via oral gavage) starting after 8 weeks of CCl4 injections. In parallel, human autopsy brain samples from patients with HE due to liver cirrhosis and age‐ and sex‐matched controls were used. Neurobehavioral testing to assess cognitive and neuromuscular function was performed. Markers of senescence (p21, p16, b‐galactosidase expression), SASPs (CCL2, TGFb1, and IL‐6) and neuroinflammation were assayed in the cerebellum and hippocampus by qPCR and immunohistochemistry.

Results

In rodent models of HE and in human autopsy samples, markers of senescence and SASP were observed in neurons of the CA1 and dentate gyrus in the hippocampus and in the purkinje cell layer in the cerebellum, regions known for their involvement in learning and memory and motor control. Treatment with D/Q reduced the number of senescent neurons, and attenuated the cognitive deficits, the neuromuscular impairment, presence of ataxia and neuroinflammation observed in the mouse model of HE.

Conclusion

Taken together, these data suggest that the acquisition of a senescent‐like phenotype in neurons in the hippocampus and cerebellum in models of Type C HE may contribute to the pathogenesis of Type C HE. Taken together our data suggests that targeting the senescence‐like phenotype in HE may be a viable option for the development of novel therapeutic strategies.
Targeting Galanin Receptor Signaling as a Novel Therapeutic Strategy for the Treatment of Fatty Liver Disease
Authors: DeMorrow Sharon , Williams Elaina , An Su Yeon , Venter Julie , Choi Won Seog , Nadeem Yusra , Chu Christopher , Petrescu Anca
Published: May 2022

Background

Non‐alcoholic fatty liver disease (NAFLD) is a common liver disease in the United States and is associated with dysregulated lipid metabolism and fat accumulation in hepatocytes (i.e. steatosis) leading to inflammation and fibrosis and cirrhosis. Galanin (Gal) is a neuropeptide with a role in food intake behavior and chronic upregulation of Gal is associated with increases in serum triglycerides, hyperinsulinemia, impaired glucose tolerance and hepatic steatosis. Targeting Gal receptor (GalR) signaling has been shown to have antifibrotic in models of cholestatic liver disease although the effects in NAFLD is unknown. The aim of this study was to evaluate the Gal/GalR axis in NAFLD and determined the effects of Gal Inhibition on the pathogenesis of NAFLD.

Methods

C57Bl6 mice were fed a western diet (WD) consisting of high fat/high sugar/high cholesterol for a total of 16 weeks. At the 4 week time point, mice were treated with the GalR1/GalR2 antagonist, M40 (1 nmol, 3X per week for the duration of the experiment), or corresponding vehicle control. Serum and liver assays of Gal, triglycerides, and cholesterol were performed using commercially available kits. The expression of Gal, GalR1, GalR2, markers of steatosis (perilipin 2, PLIN2), biliary hyperplasia (cytokeratin 19, CK19), fibrosis (collagen type 1A1, Col1A1; α‐smooth muscle actin, α‐SMA) and inflammation (chemokine C‐C motif ligand 2, CCL2; tumor necrosis factor‐α, TNFα) by qPCR and immunostaining. Liver macrophages CD11b+ and CD68+ were quantified by immunohistochemistry (IHC). Liver lipid droplets (LD) were stained with Oil Red O. In vitro, HepG2 cells were used to assess the effects of M40 on palmitate (PA)‐induced LD formation.

Results

Gal was significantly increased in the serum and liver of WD‐fed mice, with a corresponding increase in GalR1 and GalR2 expression. WD‐mice exhibited significant increase in serum transaminases, triglycerides and cholesterol compared to control mice, and M40 significantly reduced these indicators of liver injury. A drastic decrease in liver steatosis was also observed in M40‐treated WD‐mice compared to vehicle‐treated WD‐mice. M40 treatment also ameliorated WD‐induced increase in ductular reaction, fibrosis and liver inflammation in NAFLD mice. In vitro experiments confirmed that M40 decreased PA‐induced steatosis of HepG2.

Conclusions

The expression of Gal and its receptors GalR1 and GalR2, is enhanced in livers of mice on a WD. Treatment of WD‐fed mice with M40 reduces steatosis, intrahepatic biliary mass, fibrosis and inflammation. Therefore, targeting GalR1 and GalR2 may be a novel therapeutic option for the treatment of NAFLD.
Increased Neurovascular Vulnerability to Mild Traumatic Brain Injury in a Mouse Model of Marfan Syndrome
Authors: Curry Tala , Barrameda Mary E. , Bromberg Caitlin , Saber Maha , Rowe Rachel , Gonzales Rayna , Thomas Theresa C. , Esfandiarei Mitra
Published: May 2022

Over 69 million traumatic brain injuries (TBIs) are reported annually worldwide, where the geriatric population are at greatest risk for prolonged morbidity and mortality. Cerebrovascular aging contributes to this increased vulnerability through extracellular matrix (ECM) impairment, vascular wall weakening and stiffening, blood‐brain barrier (BBB) permeability, and exacerbated cytokine production, yet the mechanisms behind these contributions are minimally investigated. In order to study these targets efficiently and with minimal variability, an animal model presenting these cerebrovascular alterations is required. Fibrillin‐1 (Fbn1) protein plays a role in elasticity and inflammation, and its mutation is known to lead to ECM impairment and vessel wall weakening induced by increased availability in transforming growth factor‐b (TGF‐b) and downstream production of matrix metalloproteinases (MMPs)‐2/‐9. In mice, this mutation induces vascular dysfunction by 6M of age and is a well‐established model of Marfan Syndrome.

In this study, Fbn1+/‐ were utilized to test the hypothesis that Fbn1 mutation accelerates cerebrovascular rigidity, BBB permeability, and neurological alterations associated with aging, leaving the brain more vulnerable to diffuse TBI. In 6M‐ and 12M‐old Fbn1+/‐ and C57BL/6 wildtype (WT) male and female mice, posterior cerebral artery (PCA) blood flow (n=8‐10), PCA rupture point (N=3‐5/group), BBB permeability (N=2‐3/group), injury viability (N=5‐8/group), neurobehavioral severity scale (NSS) outcomes (N=10‐11/group), and microglial perturbation (N=1/group) were assessed.

Our data shows that 6M‐old Fbn1+/‐ mice have decreased PCA blood flow (p<0.05), compromised PCA wall strength (p<0.05), increased BBB permeability (p<0.05), and elevated NSS scores (p<0.05) as compared to 6M‐old WT, and similar to 12M‐old WT mice. Preliminary investigation of iba‐1 staining for microglia, a supported assessment of neuroinflammation, suggests increased microglial activation in 6M‐old Fbn1+/‐ mice compared to age‐matched WT mice. To investigate vulnerability to mild TBI (mTBI), varying pulse pressures (1.11‐1.32atm) were applied to the brains of 6M‐old WT (1.25‐1.32atm) and Fbn1+/‐ (1.17‐1.21atm) mice using midline fluid percussion injury, where Fbn1+/‐ mice required lowered pressure to induce mTBI righting reflex times (5‐10 minutes).

These data support that cerebrovascular aging contributes to outcome after TBI. Furthermore, this study demonstrates that Fbn1 mutation plays a critical role in the vulnerability of the aged brain to mTBI. Using this novel approach of a Marfan Syndrome mouse model that isolates cerebrovascular aging allows for the mechanistic study of potential Fbn1 downstream pathways that could serve as a therapeutic target for prevention and management of post‐concussive symptoms.
Closing in the skull: Drivers of ontogenetic changes in emu skulls, Dromaius novaehollandiae (Palaeognathae: Casuariidae)
Authors: To Khanh , Green Todd , Witmer Lawrence , Stocker Michelle
Published: May 2022

In modern birds (Palaeognathae and Neognathae), the adult skull combines tightly sutured and co‐ossified units with kinetic flexion zones, serving as a multitasking ‘second hand’. How the skull osteology changes postnatally in different bird lineages is underexplored, especially regarding the morphological and physiological changes across the altricial‐precocial spectrum. For example, it is unknown to what extent internal (i.e. functional biomechanics) or external (i.e. environmental) drivers influence the morphological changes observed through ontogeny and whether those same drivers persist across different lineages. We hypothesize that different regions of the skull (i.e. braincase, mandible, and face) develop skeletally mature features (e.g. suture closure, braincase shape change, robusticity) through ontogeny at different rates due to varying effects from various drivers. In this study, we qualitatively describe and quantitatively analyze, through 3D geometric‐morphometric (GMM) data, an ontogenetic series of 19 emus (Dromaius novaehollandiae), to examine the timing and rate of morphological changes in cranial elements through growth. We observed a mediolateral widening of the posterior portion of the braincase accompanied by an increase in robusticity of the posterior part of the mandible through development. The frontal‐parietal fontanelle closure time varies, with some midsize juvenile specimens having an almost completely or completely closed skull roof. This is in contrast with the feeding apparatus, where the articular and angular region of the mandible remain largely unfused in midsize specimens. Our GMM analysis showed juvenile, subadult, and adult specimens occupying distinct regions of morphospace, showing clear intraspecies variation during ontogeny. We plan on further using GMM to assess when morphological changes start to accumulate in the different regions of the skull and to compare it to our whole skull analysis for the morphological rate changes. With respect to the drivers of the ontogenetic changes, the effects of external drivers (e.g. food type, food availability) are likely small due to husbrandry consistency across emu farms. Internal drivers relating to functional biomechanics, however, may have a larger influence on the ontogenetic differences seen here in that the muscles of the feeding apparatus anchor onto the cranium, accounting for the observed differences in suturing and fontanelle closure and development of the braincase. The morphological complexity seen by including juveniles and subadults in our study highlights gaps in previous postnatal developmental studies. The universal drivers of postnatal ontogeny can be addressed further by applying this same method to other bird lineages on the altricial‐precocial spectrum, allowing us to investigate the degree to which feeding influences the morphological changes and timing to reach the adult condition.
Renal Biomarker Evaluation using Data Integration in the Age of Precision Medicine
Authors: Prokop Jeremy W.
Published: May 2022

Decades of work have given nephrology a handful of strong biomarkers of acute kidney injury (AKI), including clinical serum creatinine, blood urea nitrogen levels, and urine proteinuria. To refine the location of AKI to different regions of the nephron, proteins such as Albumin, NGAL, and KIM‐1 have been critical. Yet, many of our classical nephrology biomarkers are rarely evaluated considering broad patient pathologies and environmental factors such as viral infection. Millions of data points can inform on AKI in the data age. Thus, we have performed a systematic data analysis of ~10,000 blood sample precision transcriptomes for broad pathologies, ~200 RNA‐Seq samples for human AKI, the Comparative Toxicogenomics Database, Human Protein Atlas, GTEx, and our custom cell culture models of kidney response followed by advanced sequencing including direct RNA‐Seq. This data integration work elucidated biomarkers such as KIM‐1 can be elevated in blood due to viral infections and environmental contributors. In some patients, the elevation of KIM‐1 in the urine occurs due to blood activation and urine proteinuria instead of tubule secretion. However, refining KIM‐1 data with blood RNA‐Seq allows for identifying isoform switches that correlate to AKI and tubule damage.

Further work in our data integration shows that RNA specific to tubule cells or podocytes can be observed in patient blood during AKI, suggesting a promising observable measure of detailed cell types damaged that may contribute to AKI. Finally, integrating our human GWAS and expression quantitative trait loci (eQTLs) for kidney traits elucidates the ability to map response eQTLs and mechanisms from easier to obtain blood samples that can be critical in defining AKI and chronic kidney diseases. Thus, continued revaluation of kidney biomarkers in the big data age can bring nephrology into the forefront of precision medicine.
Moderate‐to‐Vigorous Physical Activity and Time‐Restricted Eating are Predictors of Fat Mass Loss in Overweight and Obese Females Following an Eight‐Week Exercise and Dietary Intervention
Authors: Kotarsky Christopher J. , Johnson Nathaniel R. , Mahoney Sean J. , Mitchell Steven L. , Schimek Regina L. , Stastny Sherri N. , Hackney Kyle J.
Published: May 2022

Background

The American College of Sports Medicine recommends 300 minutes of moderate or 150 minutes of vigorous physical activity (MVPA) per week, in combination with proper nutrition, to obtain substantial health benefits and weight loss. Fasting dietary strategies, such as time‐restricted eating (TRE), combined with resistance exercise have been shown to reduce fat mass and maintain or increase lean mass. Concurrent exercise, the inclusion of aerobic and resistance exercise, and TRE may be a valid method for preserving lean mass during weight loss while simultaneously reducing disease risk and improving functional performance.

Objective

The purpose of this investigation was to determine whether average time spent in MVPA, an indicator of concurrent exercise training volume, was a predictor of fat mass loss in physically inactive overweight and obese females following an eight‐week dietary and concurrent exercise intervention, regardless of dietary group allocation. We hypothesized that MVPA will predict decreases in fat mass observed during the intervention.

Methods

Stepwise linear regression determined the relationship between MVPA and fat mass loss. A total of 18 females (mean ± SD; age 43.7 ± 7.3 years; BMI 29.7 ± 2.3 kgm2) were included in the analysis. Body and fat mass were assessed pre‐ and post‐exercise and dietary intervention using dual‐energy x‐ray absorptiometry. Dietary intakes were estimated using three‐day dietary logs and ESHA software at weeks one, four, and seven. Dietary group allocation was recorded as “1” for TRE and “0” for normal eating. Dietary group, age (years), height (cm), pre‐intervention body and fat mass (kg), average time spent in MVPA (min/week), average energy intake (kcal/day), and average carbohydrate, fat, and protein intake (g/day) were included in the analysis. Age was self‐reported and MVPA was assessed at weeks two, five, and eight using accelerometry.

Results

Our model explained 55.7% of the variance in fat mass changes (F2, 15= 9.424; p = 0.002). Stepwise analysis indicated that reductions in fat mass were predicted first by participation in TRE (β ± SE; ‐1.739 ± 0.451; p = 0.002) and then by time spent in MVPA (β ± SE; ‐0.004 ± 0.002; p = 0.044).

Conclusion

Time spent in MVPA and TRE were predictors of fat mass loss following eight weeks of dietary and concurrent exercise intervention. The significance of MVPA to the model indicates that concurrent exercise contributes to fat loss regardless of dietary pattern.
Synthesis and Conformational Analysis of APP O ‐Glycopeptides Bearing the Tn Antigen
Authors: Cudic Mare , Singh YashoNandini
Published: May 2022

Objective

To perform a conformational analysis of APP glycopeptides by CD spectroscopy and evaluate the impact of site specific mucin‐type O‐glycosylation and/or unique patterns of O‐glycan clusters proximal to secretase cleavage sites on the APP’s secondary structure.

Alzheimer’s disease (AD) is characterized by the accumulation of the neurotoxic deposits of β‐amyloid peptide (Aβ) within the brain along with hyperphosphorylated and cleaved forms of the microtubule‐associated tau protein. Genetic, biochemical, and behavioral research suggest that physiologic generation of the Aβ forming fibrils stems from the proteolytic processing of the amyloid precursor protein (APP), a type 1 transmembrane glycoprotein, by β‐ and γ‐secretases. A small percent of AD is also caused by single genetic mutations that are passed down through families known as familial AD (FAD). The Swedish double mutation (Lys670Asn/Met671Leu), located near the N‐terminus region of Aβ results in a major increase in the total output of Aβ40 and Aβ42 by providing a better substrate for the β‐secretase enzyme. Recent findings suggest possible role of O‐glycosylation in APP’s proteolytic processing. However, due to the inherited complexity of protein glycosylation, the effect of O‐glycans on APP function, and its subsequent role in AD pathogenesis, remains challenging. Our preliminary data suggest that a unique type of O‐glycosylation, on the phenolic hydroxyl group of the tyrosine (Tyr681) can induce conformational change in APP and affect its proteolytic processing fate towards the amyloidogenic pathway. Intrigued by the number of mucin‐type O‐glycan sites that have been reported for APP in the proximity of β‐secretase site, we focused on three sites in this study, Thr663, Ser667 and Tyr681, modified with the simplest mucin‐type structure, O‐α‐GalNAc (Tn), to obtain an initial account of its direct impact on protein’s secondary structure. The APP glycopeptide models incorporating β‐ and α‐secretases sites, along with their Swedish‐double mutated versions, and the non‐glycosylated counterparts were synthesized by Fmoc solid phase peptide synthesis approach. Circular dichroism (CD) was used to analyze the secondary structure of peptides and evaluate the role of peptide environment on inducing conformational changes. The spectra were further analysed for secondary structure estimations by Beta Structure Selection (BeStSel) method, specifically designed for the analysis of beta sheet‐rich proteins. Our results show that conformation is strongly dependent on external conditions in the peptide environment such as buffer ions and solvent polarity as well as its internal modifications such as sequence length, O‐glycosylation, and Swedish mutation.
Microfluidic Fabrication and Characterization of Radiopaque Barium Sulfate Polyethylene Glycol‐Based Hydrogel Microspheres
Authors: Dharmesh Ether , Stealey Samuel , Zustiak Silviya P.
Published: May 2022

The objective of this study was to fabricate and characterize monodisperse polyethylene glycol (PEG)‐based barium sulfate hydrogel microspheres for applications in prostatic hyperplasia and prostate cancer treatments. Currently, catheter embolization procedures used in prostatic hyperplasia treatments employ non‐opaque microspheres with a tracer dye, which can result in off‐target embolization. The goal of this study was to fabricate monodisperse, radiopaque microspheres that can be easily tracked via microcomputed tomography (microCT) during embolization procedures. The hydrogel microspheres were fabricated using 4‐arm PEG‐Acrylate macromer and PEG‐dithiol crosslinker solutions in a custom‐designed microfluidic chip that allowed for on‐chip mixing and gelation of a timed‐gelation system, greatly improving bead fabrication throughput and reproducibility. Microspheres were loaded with 1 μm barium sulfate particles and bovine serum albumin to aid in barium suspension. Microspheres were imaged both before and after washing with buffer using an inverted microscope to measure microsphere diameter and degradation. Settling of barium sulfate solutions was measured qualitatively in microcentrifuge tubes. Monodisperse, barium sulfate loaded‐hydrogel microspheres were produced, the size of which could be controlled by modulating the inlet flow rates of the dispersed and continuous phases. Furthermore, the results show that the opacity of the barium sulfate microspheres increased with increased barium sulfate concentration. In conclusion, the results indicate that this study successfully fabricated monodisperse and opaque barium sulfate PEG‐based hydrogel microspheres. Future experiments will evaluate the radiopacity under microCT, swelling and degradation properties, and injectability of the hydrogel microspheres to help further confirm the application of these microspheres in catheter embolization procedures.
Design and Development of Site Specific Null Allosteric Ligands for γ‐Aminobutyric Acid Type A Receptor as Reversal Agents for General Anesthesia
Authors: Koinas Dimosthenis A. , Wu Bo , Zhou Xiaojuan , Pajak Anthony Y. , Miller Keith W. , Bruzik Karol S.
Published: May 2022

The γ‐aminobutyric acid type A receptors (GABA(A)Rs) are the main inhibitory neurotransmitter receptors in the CNS. They control the synaptic and extrasynaptic GABA‐mediated inhibitory signals in the brain. They are the target of general anesthetics, sedatives and anticonvulsants. Our overall goal is to design and develop site specific Null Allosteric Ligands (NALs) for GABA(A)Rs as reversal agents of these actions. For example, faster recovery from general anesthesia is associated with less postoperative anesthesia‐related complications such as memory loss and confusion. Whereas flumazenil is a NAL that binds to the benzodiazepine site in the extracellular domain’s (ECD) α+/γ‐ interface, there are no known NALs that bind to the transmembrane domain (TMD) sites. We adopted a strategy based on the structures of etomidate, flavanols and barbiturates as starting points, while utilizing computational docking, SAR studies and radioligand binding assays to assist in the design and development of the new agents. Here, we report the first NAL that binds to the TMD of GABA(A)Rs and that antagonizes the action of R‐mTFD‐MPAB (it binds to the TMD at the α+/β− and γ+/β− interfaces), while having a marginal effect on the binding of the agonist, [3H]muscimol. The development of the first NAL(s) targeting the TMD of GABA(A)Rs will aid in understanding GABAergic actions in the CNS, support the mechanistic studies on GABA(A)Rs and potentially lead to reversal agents for general anesthesia and sedation.
Computational and Biophysical Analysis of RNA/Protein Complexes in Histone mRNA Degradation
Authors: Lackey Patrick , Shine Morgan , Mackenstein Nicole , Pellegrene Kendy , Evanseck Jeffrey D. , Mihailescu Mihaela R.
Published: May 2022

Histone mRNA is the only known metazoan mRNA that is not polyadenylated at its 3’ end; instead, it ends in a highly conserved stem‐loop. This stem‐loop and its protein binding partner, the stem‐loop binding protein (SLBP), control every aspect of histone mRNA metabolism. As the cell prepares to degrade histone mRNA in the cytoplasm towards the end of S‐phase, both of these elements are modified; the mRNA is trimmed by 3’ human exonuclease (3’hExo) and uridylated by a terminal uridylyl transferase, while SLBP is dephosphorylated. The trimming and uridylation process creates uridylated intermediates that differ in length as the histone mRNA begins to undergo degradation, while the dephosphorylation of SLBP destabilizes the protein. Both of these events are associated with histone mRNA degradation, their exact roles in histone mRNA metabolism are not fully understood. In this study, we seek to characterize how these changes to SLBP and histone mRNA affect the stability of the ternary SLBP/3’hEXO/mRNA complex using both computational and experimental methods. To computationally characterize the effects of uridylation on stability of the ternary complex, we performed molecular dynamics simulations (1 µs) using AMBER force fields and Nanoscale Molecular Dynamics (NAMD). To experimentally characterize these observations, we used a fluorescence‐based EMSA competition assay to measure the proteins’ difference in affinity for the wild‐type stem‐loop and uridylated intermediates. Through these experiments, we have gained valuable insight into the role of both the uridylation of histone mRNA and the dephosphorylation of SLBP at the beginning of histone mRNA degradation.
Altered gut microbiome structure and its association with inflammation markers in patients with Crohn’s disease in comparison to healthy siblings
Authors: Hu Jun , Cheng Sijing , Chen Wanning , Yao Jiayin , Li Yichen , Wang Wenxia , Huang Yibo , Zhu Lixin , Zhu Ruixin , Zhi Min
Published: May 2022

Background

Previous studies reported inconsistent results regarding altered gut microbiome in patients with Crohn's disease (CD), likely due to the large impact of genetic polymorphisms and environmental factors on the structure of the gut microbiota. We aim to investigate the altered microbiome in CD with a cohort that minimizes the impact of irrelevant genetic and environmental factors on the gut microbiota.

Method

Stool samples and clinical records were collected from 91 patients withCD and their healthy siblings in the Sixth Affiliated Hospital of Sun Yat‐sen University in Guangzhou, China, between March 2014 and December 2018. Fecal DNA was isolated and the V5‐V6 region of the 16S rRNA gene was sequenced on a MiSeq platform. Data was processed with QIIME2. Spearman analysis was performed to identify the microbial features correlated with inflammatory markers.

Result

Compared to healthy siblings, CD patients exhibited reduced alpha diversities based on the metrics of Chao1, Shannon, and observed speciesat the ASV level (P<0.05). Beta diversity was significantly different between study groups according to UniFrac based principle coordinate analysis (P<0.001). Altered abundances were observed at various taxonomic levels comparing between CD patients and their healthy siblings, including increased abundance in Escherichia‐Shigella and Veillonella, and decreased abundance in Lachnospiraceae, Prevotella 9 and Faecalibacterium in CD patients. Spearman analysis identified significant correlations between Escherichia‐ Shigella and Lachnospiraceae with inflammatory markers erythrocyte sedimentation rate, C‐reactive protein, and white blood cell count (Fig.1).

Discussion

By comparing between CD patients with their siblings, the impact of the compounding genetic and environmental factors on the gut microbita was minimized. This approach allowed the identification of CD specific microbial fearures that are correlated with inflammatory markers. Further study along this line may establish CD specific microbial targets for diagnostic and therapeutic purposes.
Comparing the Effects of 30‐ and 60‐min of Acute Whole‐Body Passive Heat Stress on Peripheral Vascular Function in Older Adults
Authors: Pizzey Faith K. , Ruediger Stefanie L. , Koep Jodie L. , Askew Christopher D. , Coombes Jeff S. , Bailey Tom G.
Published: May 2022

Introduction

Macro‐ and microvascular dysfunction elevate the risk of cardiovascular disease (CVD). Heat therapy has the potential to improve vascular health and reduce CVD risk, but the optimal length of heat stress exposure is unknown. We hypothesized that 1) acute whole body heat stress (WBHS) would increase vascular function and 2) a longer WBHS period (30‐ vs 60‐min) would elicit a greater effect.

Methods

20 older adults (10 female; 64±7 y) underwent two separate periods of WBHS (30‐ vs 60‐min) via water perfused suit (48°C) in a randomized, counterbalanced design. Macrovascular function via flow‐mediated dilation (FMD) and microvascular function via skin reactive hyperemia (SKBF RH) were assessed before (PRE) and after (POST) WBHS. Core (Tcore; rectal) and skin (Tskin; 6‐site average) temperatures were monitored throughout. Repeated measures ANOVA were used to assess the effect of time (PRE vs POST) and visit (30‐ vs 60‐min) on all outcomes.

Results

Tcore and Tskin increased after both WBHS periods (Tcore: 30‐min, PRE: 36.4±0.3, POST: 36.6±0.3°C; 60‐min, PRE: 36.4±0.3, POST: 36.8±0.2°C, p=0.001; Tskin: 30‐min, PRE: 33.5±0.6, POST: 36.3±0.4°C, p<0.0005; 60‐min, PRE: 33.2±0.5°C, POST: 36.6±0.5°C, p<0.0005). FMD% was unchanged (30‐min, PRE: 8.5±5.1%, POST: 7.1±4.2%; 60‐min, PRE: 7.7±3.9%, POST: 6.6±4.3%; p=0.10) after both WBHS periods. During RH, brachial artery shear rate area under the curve was higher after 30‐ (PRE: 17.08±9.57, POST: 26.34±13.06·10‐3 AUC; p=0.003) but not 60‐min (PRE: 21.06±12.30, POST: 27.83±19.32·10‐3 AUC; p=0.186). Total SKBFAUC increased following both 30‐ (PRE: 6.31±3.22, POST: 12.82±6.44·10‐3 AUC; p<0.0005) and 60‐min (PRE: 6.01±3.24, POST: 9.609±4.882·10‐3 AUC; p=0.037), whereas peak SKBF fluxAUC increased following 30‐ (PRE: 1.86±1.54, POST: 4.15±3.07·10‐3 AUC; p=0.001) but not 60‐min (PRE: 1.58±1.31, POST: 2.93±2.77·10‐3 AUC; p=0.1113) of WBHS.

Discussion

Up to 60‐min of acute WBHS does not change macrovascular function in older adults. Interestingly, WBHS might increase downstream microvascular functional capacity. The changes in microvascular function following 30‐min of WBHS may reflect early markers of the benefits of repeated whole body heat stress.
Augmented and Virtual Reality in Anatomical Education and its Evaluation: Quality Matters
Authors: Swic Sebastian , Alkhammash Leena , Krebs Claudia
Published: May 2022

Introduction and Objective

Many studies have described augmented and virtual reality (AR/VR) teaching in anatomy as having great potential. However, for this potential to be realized, deeper exploration of the offered evidence in AR/VR tool evaluation is required. While the body of evidence may be increasing to support the use of AR/VR, the purpose of this review is to examine the gaps in implementing and evaluating AR/VR anatomical education. The focus of many reviews is on the technology with less emphasis on instructional design. This review aims to pave the way for future researchers to provide evidence based, rigorously evaluated and validated anatomical educational tools that will truly be helpful.

Materials and Methods

A literature search was conducted using search terms related to AR/VR anatomical educational tool evaluation. Included studies were evaluated for quality of research.

Results

Gaps in AR/VR anatomy education evaluation studies included lack of user‐focused design process, minimal to no re‐iterations of AR/VR anatomy educational methods, high risk of bias, low validity, and lack of standardized protocols.

Conclusion

In order to successfully and sustainably incorporate AR/VR into institutional educational curricula, high quality, comprehensive, standardized protocols of evaluation and user‐centred design approaches to meet instructional and curricular goals are required.

Significance/Implication

AR/VR is becoming increasingly available as a tool in anatomy education. It is a promising but relatively new frontier, and as such there is an increased pressure to seek out high quality evidence regarding its efficacy. These protocols must reflect a user‐centered, iterative process that begets high quality anatomical educational tools which would reliably and reproducibly lead to higher quality educational outcomes.
Acyl Homoserine Lactone Analogs as Potential Inhibitors of Quorum Sensing
Authors: Blancas Adrian , Conrad Laura M.
Published: May 2022

Gram negative bacteria are difficult to treat and are becoming increasingly resistant to conventional antibiotics. Pseudomonas aeruginosa is one such bacterium that causes opportunistic infections in hospital settings and has been recognized by the CDC and WHO as a looming threat to public health due to few treatment options and the rise of antibiotic resistance. A promising strategy to combat antibiotic resistance is to focus on virulence, rather than growth. In an antivirulence approach, the goal is to compromise the bacterium’s pathogenicity so that it is easier for the host’s immune system to clear the infection. Many Gram negative bacteria like P. aeruginosa and Chromobacterium violaceum use a LuxIR quorum sensing system to control virulence, where the LuxI synthase makes an acyl homoserine lactone signal that is detected by the LuxR transcriptional regulator, leading to the upregulation of virulence genes. One way to block virulence is to disrupt the production of the quorum sensing signaling molecules. In this study we have designed, synthesized and structurally characterized a series of potential small molecule inhibitors of the CviI synthase from C. violaceum as a model system for the more complex P. aeruginosa system. CviI converts a hexanoyl‐acyl carrier protein (hexanoyl‐ACP) and S‐adenosylmethionine (SAM) to a C6‐homoserine lactone (C6‐HSL). The potential inhibitors were designed to mimic the structural moieties of the acyl‐ACP starting material and the C6‐HSL product. The appropriate chain length should give specificity for the CviI synthase over other LuxI homologs. By varying the head group, the hope is to find an inhibitor that maximizes the affinity for the acyl‐ACP binding pocket, inhibiting the enzyme from making the C6‐HSL signal. An advantage of our methodology is that the synthesis only requires one step, which enables a quick production of a library to elucidate structure‐activity relationships. In future experiments, these compounds will be assayed in C. violaceum to determine if they possess anti‐quorum sensing and, specifically, anti‐CviI activity. The information gained could serve as a guide for future quorum sensing inhibitor development for P. aeruginosa and other Gram negative pathogens.
Liver‐specific Deletion Of Small Heterodimer Partner Alters Enterohepatic Bile Acid Levels And Promotes Bile Acid‐Mediated Proliferation In Male Mice
Authors: Shaw Ryan P. , Kolyvas Peter , Dang Nathanlown , Anakk Sayee
Published: May 2022

Small heterodimer partner (Shp) regulates several metabolic processes, including bile acid levels, but lacks the conserved DNA binding domain. Phylogenetic analysis revealed conserved genetic evolution of Shp, Fxr, Cyp7a1 and Cyp27a1, underscoring the importance of these molecules in maintaining bile acid homeostasis. Shp, although primarily studied as a downstream target of Farnesoid X Receptor (Fxr), has a distinct hepatic role that is poorly understood. Here we report that liver‐specific Shp knockout (LShpKO) mice have impaired negative feedback of Cyp7a1 and Cyp8b1 upon bile acid challenge and demonstrate that a single copy of the Shp gene is sufficient to maintain this response. LShpKO mice also exhibit elevated total bile acid pool with higher bile acid fraction in the intestine mimicking the 1% cholic acid (CA) fed control mice. Agonistic activation of Fxr (GW4064) in the LShpKO did not alter the elevated basal expression of Cyp8b1 but lowered Cyp7a1 expression. We found that deletion of Shp led to an enrichment of distinct motifs and pathways associated with circadian rhythm, amino and carboxylic acid metabolism, copper ion transport, and DNA synthesis. LShpKO livers displayed a higher basal proliferation that was exacerbated specifically with bile acid challenge but not with another liver mitogen, TCPOBOP (TC). Overall, our data indicate that hepatic SHP uniquely regulates certain proliferative and metabolic cues.
Expression of Key Modulators of Serotonergic Neurotransmission after Chronic Metformin Treatment
Authors: Greene Susan M. , Bordas Blanka , Alcala Gloria‐Andrea , Sanchez Yatzil R. , Penta Mithil K. , Honan Lauren E. , Gomez Jorge A. , Ginsburg Brett C. , Daws Lynette C. , Gould Georgianna G.
Published: May 2022

Despite metformin’s popularity as a treatment for metabolic and developmental disorders its mechanisms of action are still unknown. The goals of this project were to (1) assess the behavioral benefits of chronic metformin treatment alone for core autism symptoms, (2) assess if metformin acts on melanocortin 4 (MCR4) receptors in the brain to alter hormone levels in serum, and (3) to determine if metformin increases brain levels of peroxisome proliferator‐activated receptors α, δ, and γ (PPARs), which modulate insulin signaling throughout the body and increase in the liver with chronic metformin treatment. Since BTBR social behavior is enhanced by selective serotonin reuptake inhibitors (SSRIs) such as sertraline, and their chronic use reduces or otherwise alters receptor and transporter expression in the brain, we hypothesized that with chronic metformin treatment, expression of key regulators of serotonin neurotransmission such as the serotonin transporter (SERT) or organic cation transporters (OCTs) responsible for serotonin clearance would be reduced. Also, given prior evidence that chronic SSRI treatment increases serotonin levels in brain extracellular fluid, we hypothesized that expression of serotonin receptors such as 5‐HT2A among others would be reduced. This compensatory response occurs with chronic SSRI treatments. To explore these hypotheses BTBR T+ Itpr3tf/J (BTBR) and C57BL/6J (C57) mice were given chronic metformin treatment for six weeks, with behavior tests concluding in week 5, before euthanasia and blood and brain collection. With chronic metformin we found social interaction preference and social dominance were enhanced in male but not female BTBR mice. Blood serum was analyzed for hormonal changes, with C57 metformin treated mice seeing a reduction in corticosterone compared to controls. PPARδ was lower for metformin treated female C57 mice than control females, while PPARγ was found to be different between strain controls. Chronic metformin elevated blood glucose levels in female but not male mice. Male mice showed no changes in MCR 4 or SERT expression. Immunohistochemistry revealed an increase in OCT3 labeling in the brain of a BTBR male treated with metformin compared to a BTBR control male. The density of 5‐HT2A receptors was decreased in the anterior olfactory nucleus for BTBR mice following chronic metformin treatment. Overall, these findings indicate chronic metformin treatments that enhance social behaviors in male, but not female BTBR mice also have divergent effects on blood sugar among sexes. We did not find any evidence of chronic metformin treatment altering MCR4 or SERT but there was a decrease in 5‐HT2A expression. Effects on hormones were not present for BTBR mice but corticosterone was lower for C57 metformin treated males than controls, and metformin may increase OCT expression in BTBR males.
ACE2 Ubiquitination in the Paraventricular Nucleus of the Hypothalamus Contributes to Angiotensin‐II‐Induced Hypertension in Mice
Authors: Mohammed Mazher , Elgazzaz Mona , Berdasco Clara , Lakkappa Navya , Awoal Md Abdul , Mobasheran Parnia , Filipeanu Catalin , Lazartigues Eric
Published: May 2022

Ubiquitination is a post‐translational modification of proteins where the ubiquitin moiety is covalently attached at the C‐terminus to specific lysine residues on the target protein, leading to degradation in proteasome or lysosomes. Angiotensin converting enzyme 2 (ACE2) is a transmembrane protein with a primary role in converting Angiotensin (Ang)‐II into Ang‐(1‐7) and thereby reducing blood pressure (BP). We previously reported that ACE2 undergoes internalization and degradation via ubiquitination in response to Ang‐II. Here we investigated whether ACE2 ubiquitination in the paraventricular nucleus of the hypothalamus (PVN), contributes to Ang‐II mediated hypertension in mice. Wildtype C57BL/6J (WT, n=6) and ACE2 KO (n=6) male mice were bilaterally injected into the PVN with an adeno‐associated virus vector expressing a ubiquitin resistant ACE2 mutant in which 5 lysine residues from the C‐terminus of the human ACE2 protein were replaced with arginine (hACE2‐5R). Six‐weeks later, anesthetized mice were connected to a stereotaxic setup and BP was recorded from the common carotid artery. Focal microinjections of Ang‐II (100 ng in 100 nL) were administered into PVN, and BP responses were analyzed. In another group, mice were chronically implanted subcutaneously with BP telemetry and administered Ang‐II via osmotic minipump (600 ng/kg/day) for 2‐weeks. In comparison to WT mice (n=6), acute microinjections of Ang‐II into PVN resulted in a significantly attenuated BP response in hACE2‐5R transfected WT mice (9±1 vs. 14±2 mmHg; n=6, p<0.05). A similarly attenuated response was observed in ACE2 KO mice (n=8) expressing hACE2‐5R when compared to ACE2 KO mice (7±2 vs. 16±3, n=5, p<0.05). Furthermore, chronic Ang‐II‐infused WT and ACE2 KO mice expressing hACE2‐5R exhibited a similar reduction of hypertension (125±2 and 121±1 mmHg, respectively) in comparison to their naïve WT and ACE2 KO controls (137±1 and 148±2 mmHg, respectively, p<0.05). Protein analysis revealed a significant attenuation of AT1receptor expression and increased ACE2 activity in the hypothalamus of mice transfected with hACE2‐5R in the PVN. Our results demonstrate that ACE2 is ubiquitinated by circulating Ang‐II and overexpression of ubiquitination resistant ACE2 enhances the enzyme’s activity and decreases BP in hypertensive mice.
Loss of ATAD3A contributes to NAFLD through the accumulation of lipids and damaged mitochondria
Authors: Chen Liting , Li Yuchang , Sottas Chantal , Lazaris Anthoula , Petrillo Stephanie K. , Metrakos Peter , Li Lu , Garza Samuel , Papadopoulos Vassilios
Published: May 2022

Mitochondrial ATPase ATAD3A is essential for cholesterol transport, mitochondrial structure, and cell survival. However, the relationship between ATAD3A and non‐alcoholic fatty liver disease (NAFLD) is largely unknown. In this study, we found that ATAD3A was upregulated in the progression of NAFLD in livers from rats with diet‐induced non‐alcoholic steatohepatitis (NASH) and in human livers with NAFLD. CRISPR‐Cas9 was used to delete ATAD3A function in Huh7 human hepatocellular carcinoma cells to assess the influence of ATAD3A deletion on liver cells with free cholesterol (FC) overload induced by treatment with cholesterol plus 58035, an inhibitor for acetyl‐CoA acetyltransferase, the enzyme converting FC to cholesterol ester. The results showed that ATAD3A KO exacerbated FC accumulation under FC overload in Huh7 cells. Triglyceride (TG) levels were also significantly increased in ATAD3A KO Huh7 cells under FC overload and control conditions via inhibited lipolysis mediated by upregulation of perilipin 2. Moreover, loss of ATAD3A downregulated mitophagy‐associated PTEN‐induced kinase 1 expression in Huh7 cells under FC overload and control conditions, suggesting that ATAD3A KO blocks mitophagy. Consistently, mitochondrial mass was increased in ATAD3A KO cells under FC overload as indicated by mitochondrial protein translocase of outer mitochondrial membrane 20 (TOM20). The results also showed that loss of ATAD3A impaired mitochondrial basal respiration and ATP production in Huh7 cells under FC overload, accompanied by downregulation of mitochondrial ATP synthase. In conclusion, loss of ATAD3A promotes the progression of NAFLD through the accumulation of FC, TG, and damaged mitochondria in hepatocytes.
Microbiota of Haemaphysalis longicornis Tick in Korea
Authors: Yong Tai‐Soon , Kim Ju Yeong
Published: May 2022

Ticks can transmit pathogenic bacteria, protozoa, and viruses to humans and animals. In this study, we investigated the microbiomes of Haemaphysalis longicornis according to sex and life stages. The Shannon index was significantly higher for nymphs than adult ticks. Principal coordinates analysis showed that the microbiome composition of female adult and male adult ticks were different. Notably, Coxiella‐like bacterium (AB001519), known as a tick symbiont, was found in all nymphs and female adult ticks, but only one out of 4 male adult ticks had Coxiella‐like bacterium (AB001519). In addition, Rickettsia rickettsii, Coxiella burnetii, and Anaplasma bovis were detected in this study.
Extension of the isogravimetric method for the determination of the capillary filtration coefficient CFC
Authors: Petrow Jordan M.
Published: May 2022

In 1948, J.R. Pappenheimer made the decision to allow blood pressure to act from the capillary toward the interstitium in CFC determination. With this decision, he was inevitably confronted with the fact that an interstitium with unknown properties stood in his way during CFC determination. Depending on how these properties turn out, the experimental conditions change drastically and the measurements give a wrong result. In the example of muscle tissue, contrary to expectations, the effective fitration pressure (EFP) across the capillary membrane does not remain constant in this method, but quickly drops to zero. As a result, the measurement result is calculated to be much smaller than the actual permeability of the capillary membrane.

When this problem was recognized in the method of Pappenheimer and Soto Rivera, the simpler way was chosen by allowing the pressure to act in the opposite direction, coming from the interstitium and going outward. As a first step, the tissue was flooded with fluid and then squeezed outward in a pletysmograph. A tissue model was first used to demonstrate that the EFP remained constant in this case. The new method for CFC determination has shown that the CFC in the muscle tissue can be estimated to be many times larger than the CFC measured in the past using the method of Pappenheimer and Soto Rivera.

For the muscle tissue in the rabbit experiment, a CFC= 0.130±0.012 ml/mmHg.100g was determined at that time, which was considerably larger than the data known from the literature around 0.008 ml/mmHg.100g