bluuebunny/crossref_metadata_2025 huggingface dataset:
Sexual dimorphism in AngII/AT1R‐mediated cognitive and cardiovascular dysfunction in a mouse model of Alzheimer’s Disease
Authors: Foroozandeh Parisa , Yang Liping , Lee Gloria , Sabharwal Rasna
Published: May 2022

Alzheimer’s disease (AD) is the most common form of dementia in the elderly population (>65 years). AD is pathologically characterized by the presence of amyloid‐beta plaques (Aβ) and neurofibrillary tangles (Tau) in the brain. Progressive increases in systolic blood pressure (SBP) and BP variability (BPV) with aging, likely contribute to cognitive decline. Moreover, blockade of angiotensin II (AngII) actions on type 1 receptors (AT1R) has been shown to be effective against dementia and autonomic dysfunction. Therefore, we hypothesized that enhanced AngⅡ/AT1R signaling contributes to cognitive and cardiovascular/autonomic decline in AD. Apolipoprotein E4 (ApoE4) is the most prevalent genetic risk factor associated with AD. In this study, we have utilized human ApoE4‐knockin (E4) and human ApoE3‐knockin (E3) mice. SBP and heart rate (HR) were measured by telemetry in E3 (n=7) and E4 (n=11) mice beginning from 10 weeks to 70 weeks of age. BPV was calculated as SD of BP, while resting cardiac sympathetic tone was estimated as the HR response to b‐adrenergic receptor antagonist propranolol (2 mg/kg, IP). Quantitative polymerase chain reaction (qPCR) was used to measure expression of AT1R in the hippocampus (HC; brain site for learning and memory), paraventricular nucleus of hypothalamus (PVN; brain site for cardiovascular/autonomic regulation), left ventricle (LV; heart) and skeletal muscle (SKM; quadriceps). At 10 weeks of age, there were no significant differences in SBP, BPV, sympathetic tone and cognition (Barnes maze) between E3 and E4 mice. Notably, female E4 mice exhibited increases in SBP, increases in BPV, exaggerated sympathetic tone, and cognitive decline >40 weeks of age (p<0.05 vs. E4 males). Moreover, AngⅡ in cerebrospinal fluid (CSF) was markedly increased in female E4 mice (p<0.05 vs.E4 males). In contrast, E3 mice did not exhibit significant sex differences with aging. At 10 weeks of age, AT1R expression in HC, PVN and LV was greater in the female E4 mice, and continued to increase further with aging (p<0.01‐0.0001 vs.male E4 and E3 mice). Surprisingly, AT1R expression in the LV of E4 female mice was 10‐times higher versus other tissues, despite normal cardiac function (mouse echocardiography). Collectively, the data from this study suggests that enhanced AngⅡ/AT1R signaling in the female ApoE4 carriers, contributes to cardiovascular and cognitive decline with aging.
Lipin Expression Correlates to Differences in Phospholipid Profiles in Drug‐Resistant Prostate Cancer Cells
Authors: Finnerty Morgan C. , Cummings Brian S.
Published: May 2022

PURPOSE

The association between clinical outcomes of prostate cancer progression and lipid remodeling is not well understood. Although it is known that increases in select circulating lipids correlate to decreased patient survival, the mechanisms mediating alterations in these lipids are not fully explained. We addressed this gap‐in‐knowledge using in vitro models of non‐cancerous, hormone‐sensitive, castration‐resistant prostate cancer (CRPC), and docetaxel resistant (DR) CRPC cell lines combined with quantitative HPLC‐ESI‐Orbitrap‐MS lipidomic analysis.

HYPOTHESIS

We hypothesized that the expression of lipin (phosphatidic acid phosphatase), an enzyme mediating the conversion of phosphatidic acid to diacylglycerol, correlates to changes in lipidomic profiles in prostate cancer cells. We further hypothesized that the lipidomic profile of metastatic CRPC cell lines (PC‐3 and DU‐145) will shift as they are undergoing multiple treatments of docetaxel.

METHODS

Lipids were isolated using the Bligh‐Dyer extraction from non‐cancerous, hormone‐sensitive, CRPC, and DR‐CRPC cell lines. Lipids were initially analyzed using an untargeted shotgun approach (ESI‐MS), followed by a targeted‐based quantitative HPLC‐ESI‐Orbitrap‐MS approach. Post data acquisition were based on multiple methods including isotope, carbon number (to internal standards) and ionization efficiency‐based corrections. Online resources and software's utilized included MetaboAnalyst, LIPIDMATCH, LIPID MAPS, XCMS, and MZmine.

Lipin‐1 expression in cells was determined using immunoblot analysis. Docetaxel‐sensitive traits were obtained after five treatments of 1 nM docetaxel between passages of the CRPC cell line PC‐3. Results were demonstrated by a 3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐Diphenyltetrazolium Bromide (MTT) assay.

RESULTS

Our data showed significant changes in the abundance of lipid species between the various cell lines and a correlation between select lipid species and the progression of prostate cancer. Prominent among these were the levels of phosphatidic acid (PA) and diacylglycerol (DAG). Most notably, PA levels in cells tended to inversely correlate with DAG levels. These levels correlated to the decreased expression on lipin, specifically lipin‐1.

CONCLUSIONS

Distinct phospholipid classes were observed to have increased levels in prostate cancer cells, as compared to non‐cancer cells. The protein expression of lipin‐1 in most prostate cell lines correlated to the abundance of PA, excluding the DR cell lines. This suggests that altered lipin expression correlates to decreased survival. Additionally, dosing the parent and treated PC‐3 cells with a range of docetaxel indicated that the 5x1nM treated cells had a larger cytotoxic effect to docetaxel, as compared to the non‐treated cells.

REFERENCES

Ingram, L.M., et al., Identification of lipidomic profiles associated with drug‐resistant prostate cancer cells. Lipids Health Dis, 2021. 20(1): p. 15.
Characterization of Fly POLR1D Mutations in a Clinically Relevant Residue Associated with Treacher Collins Syndrome (TCS)
Authors: Pascual Haleigh G. , Belkevich Alana E. , Palumbo Ryan J. , Knutson Bruce A.
Published: May 2022

Treacher Collins Syndrome (TCS) is an extreme craniofacial disorder caused by mutations in genes important for RNA polymerase I (Pol I) transcription. Pol I is a multi‐subunit complex that transcribes ribosomal DNA (rDNA) to synthesize ribosomal RNA (rRNA). Two Pol I subunits often mutated in TCS are POLR1D and POLR1C which form a heterodimer that is important for Pol I complex assembly. Using fruit flies (D. melanogaster) as a model system, we mapped a fly POLR1D mutation that displays a severe developmental arrest phenotype in a clinically relevant residue where in a TCS patient this residue is mutated from a glycine residue to a bulky, negatively charged glutamic acid residue. In the fly mutant collection, this glycine residue is mutated to a bulkier but positively charged arginine residue. We used a simple in vitro co‐expression system to examine the biochemical impact of these mutations on fly and human POLR1D and POLR1C heterodimer formation in vitro. We also complement our in vitro work with a chimeric yeast (S. cerevisiae) model in vivo where together we found that in the same mutated residue, there is a defect that impacts heterodimer formation and Pol I and III complex integrity. Our results show that fly POLR1D is a suitable model system for human TCS mutants.
Maternal sleep disordered breathing during gestation produces sexually dimorphic autism‐relevant synaptic and behavioral aberrations in the offspring associated with excessive mTOR cortical signaling
Authors: Vanderplow Amanda M. , Kermath Baily A. , Bernhardt Cassandra R. , Gums Kimberly T. , Radcliff Abigail , Baker Tracy L. , Watters Jyoti J. , Cahill Michael E.
Published: May 2022

Sleep disordered breathing (SDB) is characterized by recurring breathing cessations during sleep, causing intermittent hypoxia (oxygen deprivation) often several hundred times per night. Obstructive sleep apnea is the most common form of SDB in pregnancy, and confers risk for detrimental maternal‐fetal outcomes. Although many of the maternal risk factors for the onset SDB during pregnancy and the development of autism spectrum disorders (ASD) in her offspring are highly overlapping (e.g., maternal obesity, advanced maternal age), no studies to date have empirically investigated the potential link between these conditions. We subjected pregnant rat dams to intermittent hypoxia or normoxia (GIH and GNX, respectively) from gestation day 10‐21 to investigate the consequences of maternal SDB on offspring neural function. We found that male GIH offspring exhibited deficits in several behaviors which were accompanied by increased pyramidal neuron dendritic spine density in the medial prefrontal cortex (PFC). These effects appear to arise from a disruption of normal developmental synaptic pruning late in childhood and persisting into early adolescence. The mTOR kinase signal transduction pathway has emerged as a critical regulator of dendritic spine formation, and dysregulation of key components of this pathway are implicated in the etiology of the increased cortical dendritic spine density of ASD. Additionally, we found that mTOR is aberrantly activated in the prefrontal cortex of male GIH offspring. Furthermore, inhibition of mTOR by rapamycin treatment significantly reduced behavioral abnormalities within GIH offspring. These findings suggest an opportunity for clinical intervention for offspring of the SDB maternal model by targeting the mTOR signaling pathway.
Effects of Beta‐Blockers on Thermal and Cardiovascular Strain of Adults With Coronary Artery Disease During Extreme Heat Events
Authors: Chaseling Georgia , Batlett Audrey‐Ann , Capon Anthony , Crandall Craig , Fiatarone Singh Maria , Bi Peng , Nigam Anil , Jay Ollie , Gagnon Daniel
Published: May 2022

Introduction

Extreme heat is associated with a greater risk of adverse cardiovascular events, especially in people with cardiovascular disease. Many patients with cardiovascular disease are prescribed beta‐blockers. Some research suggests that in young healthy adults, cardio‐selective beta‐blockers may alter heat loss capacity. However, the effects of beta‐blockers on temperature regulation in older adults during an extreme heat event are unknown. The objective of this study was to compare thermal and cardiovascular responses during simulated extreme heat events between older adults with coronary artery disease (CAD) who use and do not use beta‐blockers. It was hypothesised that the increase in heart rate and skin blood flow would be smaller in CAD patients who use beta‐blockers compared to those who do not use beta‐blockers.

Method

25 older adults (23 males/2 females) with stable CAD, 18 taking cardio‐selective beta‐blockers (BB: 66±8 y; 85.7±13.3 kg; 28.0±4.6 kg/m2) and 7 not taking beta‐blockers (NBB: 66±7 y; 77.1±14.6 kg; 26.1±3.9 kg/m2), were exposed to two 3‐hour simulated extreme heat events; one hot and humid (38°C, 60% relative humidity) and one hot and dry (45°C, 10% relative humidity). Rectal and mean skin temperatures, heart rate, and skin blood flow were continuously recorded. Whole body sweat losses were calculated from changes in nude body weight.

Results

At the end of the 3‐h hot and humid heat exposure, relative to pre‐exposure baseline the change in heart rate (BB: +7±5 bpm; NBB: +11±9 bpm, p=0.20), rectal (BB: +0.57±0.27°C; NBB: +0.60±0.31°C, p=0.76) and mean skin (BB: +5.1±1.2°C; NBB: +5.1±1.1°C, P=0.91) temperatures, and whole body sweat losses (BB: 771±480 g; NBB: 798±172 g, p=0.88) did not differ between groups. The change in skin blood flow from baseline was greater in the NBB (+32±23 arbitrary units) compared to the BB (+9±7 arbitrary units; p=0.01) group. At the end of the 3‐h hot and dry heat exposure, the increase in heart rate (BB: +9±8 bpm; NBB: +9±5 bpm, p=0.93), rectal (BB: +0.61±0.40°C; NBB: +0.62±0.22°C, p=0.91) and mean skin (BB: +5.9±0.9°C; NBB: +5.7±1.3°C; p=0.79) temperatures, whole body sweat losses (BB: 1252±174 g; NBB: 1207±169, p=0.56) and skin blood flow (BB: +26±22 arbitrary units; NBB: +26±39 arbitrary units; p=0.98) from baseline did not differ between groups.

Conclusion

Our preliminary evidence indicates that cardio‐selective beta‐blocker use does not alter thermal or cardiovascular strain in adults with stable coronary artery disease during simulated hot and humid or hot and dry extreme heat events.
SUN11602, a novel bFGF mimetic, exerts neuroprotective effects in Parkinson's disease
Authors: Casili Giovanna , Ardizzone Alessio , Bova Valentina , Campolo Michela , Lanza Marika , Filippone Alessia , Paterniti Irene , Esposito Emanuela
Published: May 2022

Parkinson's disease (PD) is the second most frequent neurodegenerative disease, with a large prevalence in industrialized countries. The etiopathogenesis of PD is multifactorial and not yet fully known, however, in the last few decades, scientific world advised the establishment of a neuroinflammatory state among the possible risk factors. In this field, basic fibroblast growth factor/fibroblast growth factor receptor 1 (bFGF/FGFR1) could be a promising way to treat CNS‐mediated inflammation; however, the use of bFGF as a therapeutic agent is limited by its side effects.

The novel synthetic compound SUN11602 exhibited neuroprotective activities like bFGF, but demonstrating greater safety, thus constituting a potential candidate for the treatment of neurodegenerative diseases including PD. In this perspective, this study aimed to evaluate the effect of SUN11602 administration in a murine model of MPTP‐induced PD. PD was induced by intraperitoneal injection of MPTP (80 mg/kg). SUN11602 (1, 2.5, and 5 mg/kg) was administered daily by oral gavage starting from 24 hours after the first administration of MPTP, mice were sacrificed 7 days after MPTP induction. The results obtained showed that SUN11602 administration significantly reduced the alteration of PD hallmarks, attenuating the neuroinflammatory state via modulation of glial activation, NF‐kB pathway and cytokine overexpression. Furthermore, we demonstrated that SUN11602 treatment rebalanced Ca2+ overload in neurons by regulating Ca2+‐binding proteins, inhibiting the apoptotic cascade. Therefore, considering these findings, SUN11602 could be considered a valuable pharmacological strategy for PD.
Centromere Innovations with a Mouse Species
Authors: Pandey Nootan , Gambogi Craig , Dawicki‐McKenna Jennine , Arora Uma , Logsdon Glennis , Ma Jun , Lamelza Piero , Lampson Michael A. , Dumont Beth , Black Ben E.
Published: May 2022

Mammalian centromeres direct faithful genetic inheritance at cell division and are typically found in regions of highly repetitive DNA, such as a‐satellite in humans and minor satellite in many mouse species. In the house mouse M. musculus, the 120 bp DNA monomers are nearly identical (~95%) to each other, and CENP‐A nucleosomes containing the centromeric histone H3 variant, CENP‐A, are positioned with their center position, the nucleosomal dyad, within the DNA recognition element for the sequence‐specific DNA‐binding protein, CENP‐B. We find that CENP‐B‐/‐ mice have precisely the same positioning of CENP‐A nucleosomes as CENP‐B+/+ mice, indicating a potential role for DNA sequence in the positioning of CENP‐A nucleosomes. M. pahari diverged from M. musculus ~ 4 M years ago and has been reported to have a different general DNA sequence organization at centromeres, so we sought to determine the features of centromeric chromatin that were conserved between these species. We found that, on most M. pahari centromeres, CENP‐B is of very low abundance but is extremely enriched on a single chromosome. Using multiple genomic strategies, we identified the most abundant centromere repeat in M. pahari that we term pi‐satellite, which is ~189 bp long and organized into tandem repeat arrays. Chromosomes harboring pi‐satellite lack CENP‐B boxes entirely. Additionally, we employed a more sophisticated strategy to identify a less abundant centromere satellite that contains the CENP‐B box. This variant exhibits greater homogenization, is 188 bp long, and is found exclusively on the single centromere containing extremely high levels of CENP‐B. This centromere also recruits more constitutive heterochromatin, marked by H3K9me3, consistent with a role for CENP‐B in driving pericentromeric heterochromatin. Together, these findings reveal that a mouse species is undergoing dramatic molecular differences directed by evolutionary innovations in centromere DNA sequence.
Locus coeruleus noradrenergic neurons mediate panic‐like escape response elicited by CO2
Authors: Ripamonte Gabriel C. , Fonseca Elisa M. , Vilella‐Costa Heloisa H. , Zangrossi Helio , Bícego Kênia C. , Plummer Nicholas W. , Jensen Patricia , Gargaglioni Luciane H.
Published: May 2022

The CO2exposure has been used to investigate the panicogenic response in patients with panic and other anxiety disorders since these patients are more sensitive to this stimulus, and therefore, more likely to experience the “suffocation false alarm” which, in turn, triggers the panic attack. It is well described that imbalances in the modulation of Locus coeruleus noradrenaline (LC‐NE) neurotransmission are responsible for several psychiatric disorders, including panic disorder and these neurons are sensitive to changes in CO2/pH. Therefore, we investigated the participation of LC‐NE neurons in the CO2‐induced panic like scape response by using C56BL/6 mice with a conditional knockout allele of Dbh (DbhcKO) crossed with En1cre (En1CreDbhcKO ‐ LC‐NE mutants). In addition, an intermediate genotype animal of the same genetic background was used (WT DbhcKO) as well as control animals (WT/WT) of both sexes (10‐12 weeks; 20‐25 g). Mice were placed in chamber where behavioral responses such as escape (jumping/running) and time spent immobile (freezing) were recorded under 20% CO2 during 7 min. CO2‐enriched air evoked an active escape response (jumping behavior) interpreted as escape attempts. En1CreDbhcKO mutants had a blunted jumping response (P=0.001) and spent more time in freezing compared to the other groups (P<0.0001). Furthermore, En1CreDbhcKO animals had fewer racing episodes (P=0.028) compared to WT/WT animals, but not different from WT DbhcKO group, that also presented a long freezing time, little movement, and a small number of jumps. No sex difference was observed among groups. These findings suggest that noradrenaline originating from the LC has an important role in the panic‐like escape response elicited in mice by exposure to CO2 in a sex independent way.
How does S‐palmitoylation affect the Organic Anion Transporting Polypeptide 1B1 (OATP1B1)?
Authors: Villanueva Cecilia E. , Hagenbuch Bruno
Published: May 2022

Background

Organic Anion Transporting Polypeptide 1B1 (OATP1B1) is an important transporter localized to the basolateral membrane of human hepatocytes that mediates the uptake of numerous therapeutics like statins, antibiotics, and anti‐cancer agents. Previous studies from our lab suggest that OATP1B1 is localized in membrane microdomains, also known as lipid rafts, which contain various components like saturated lipids, cholesterol, and lipidated proteins. Lipidated proteins are frequently the result of S‐palmitoylation, a reversible post translational modification that adds palmitic acid (C16:0) to cysteine residues. Currently, not much is known about the potential impact of S‐palmitoylation on OATP1B1 function and localization. Aim: We hypothesize that OATP1B1 is S‐palmitoylated and that this affects its function and localization.

Methods

We measured uptake of the model substrate estradiol‐17β‐glucuronide in cells expressing OATP1B1. S‐palmitoylation was detected using an acyl‐biotin exchange (ABE) assay in combination with western blotting. To prevent S‐palmitoylation, cells were preincubated with 2‐bromopalmitate (2BP). Expression of OATP1B1 at the plasma membrane was assessed using surface biotinylation.

Results

The ABE assay demonstrated that OATP1B1 is S‐palmitoylated and that pretreatment of the cells for 18 hours with 2BP reduces S‐palmitoylation. Inhibition of S‐palmitoylation with 2BP for 18 hours also resulted in decreased OATP1B1‐mediated transport of estradiol‐17β‐glucuronide as well as in a reduction of surface expression of OATP1B1.

Summary and Conclusions

Our results demonstrate that OATP1B1 is S‐palmitoylated. Inhibition of S‐palmitoylation reduces the function and the surface expression of OATP1B1. Thus, these findings suggest that S‐palmitoylation is a post‐translational modification involved in the regulation of this important hepatic drug uptake transporter.
Modulatory capacity correlates with dietary diversity in three species of decapod crustaceans
Authors: Powell Daniel J. , Miller Alexandra I. , Kazmi Jacob S. , Bukowski‐Thall Grace , Dickinson Patsy
Published: May 2022

The central nervous systems of decapod crustaceans contains numerous amines, amino acids, and peptides that modulate the central pattern generating (CPG) circuits found within its stomatogastric nervous system (STNS) and cardiac ganglion (CG); over 30 modulators have been identified in one species of crab (C. borealis). CPGs in the STNS are responsible for internally chewing (Gastric Mill CPG) and filtering food (Pyloric CPG) into the midgut, while the CG drives the heartbeat. Neuromodulation allows these CPGs to flexibly produce a variety of output patterns; however, the variety of modulators exceeds the variety of induced output, leading us to ask why so many modulators are present. Although modulatory capacity, a measure of the extent to which a neuronal circuit can be modulated, may be solely an inherited trait, we hypothesize a functional correlation: decapods that need more behavioral flexibility utilize a broader range of modulators than those with more stereotyped behaviors. We thus predicted that decapods with broad diets would have a larger modulatory capacity in the STNS, but not the CG, than those with limited diets. To test this, we compared responses of the STNS and CG CPGs in three species of majoid crabs (Pugettia producta, Libinia emarginata, and Chionoecetes opilio) to the same neuromodulators. L. emarginata and C. opilio both have broad diets, while P. producta primarily eats kelp. With one exception, each species’ CG exhibited similar responses to all modulators. The STNS of crabs with broader diets responded similarly to all modulators, whereas the P. producta STNS showed limited responses to the same set of neuromodulators. CG responses did not follow this trend, as all crabs showed varied CG response to modulation. Modulators: Cancer borealisTachykinin Related Peptide (CabTRP), Crustacean Cardioactive Peptide (CCAP), Red Pigment Concentrating Hormone (RPCH), Myosuppressin (Myo), Oxotremorine (Oxo), Dopamine (DA), Proctolin (Proc).
>Clopidogrel Rescues the Adverse Cerebral Vascular Effects Associated with Angiotensin II‐Induced Hypertension
Authors: Kuszynski Dawn , Dorrance Anne , Lauver Adam
Published: May 2022

Hypertension is a common risk factor for thrombotic diseases like heart attack and stroke. Chronic high blood pressure causes endothelial dysfunction which accelerates the atherosclerotic process resulting in plaque instability. Since hypertensive patients have an increased risk of thrombotic diseases, many are prescribed the antiplatelet drug, clopidogrel. The present study sought to determine clopidogrel’s effect on blood pressure, cerebral blood flow, and vascular remodeling in angiotensin II (Ang II)‐induced hypertensive mice. Previous results from our laboratory demonstrated that clopidogrel attenuated P2Y2‐induced vasoconstriction in cerebral arteries which could result in an increase in downstream cerebral blood flow. Therefore, we hypothesized that clopidogrel increases cerebral blood flow and decreases vascular remodeling in Ang II‐induced hypertensive mice. Ang II infusion pump implantation or sham surgeries were performed in 48 C57BL/6 mice at 16‐18 weeks of age. Ang II was infused continuously at a rate of 800ng/kg/min for 4 weeks. The mice were also administered vehicle or clopidogrel (10mg/kg/day) starting the day after surgery. Data are presented as means ± SEM, n = 8‐12 mice/group. Ang II significantly reduced blood flow, and clopidogrel‐treated mice had blood flow that was not different from either the sham or Ang II mice (sham vehicle: 305.6 ± 16.17; sham clopidogrel: 313.0 ± 15.27; Ang II vehicle: 244.1 ± 12.76; Ang II clopidogrel: 267.6 ± 14.96). Posterior cerebral arteries were harvested from animals at the end of the experiment. The outer and lumen diameters were reduced in the vessels in Ang II treated mice. However, clopidogrel treatment did not modify this vascular remodeling in the Ang II treated mice. The results suggest that clopidogrel demonstrates protective potential in hypertensive mice. Further studies are required to determine the long‐term effects of clopidogrel on hypertension associated vascular remodeling.
Fibroblast Growth Factors are Associated with Parenchymal Hemorrhagic Infarction Following ELVO
Authors: Sands Madison , Ihsan Fizra , Frank Jacqueline , McLouth Chris , Maglinger Benton , Trout Amanda , Turchan Jadwiga , Stowe Ann , Fraser Justin , Pennypacker Keith
Published: May 2022

Objective

The goal of this study was to analyze possible associations between fibroblast growth factors (FGFs) and hemorrhagic conversion (HC) in patients with acute ischemic stroke that underwent mechanical thrombectomy (MT).

Background

Emergent Large Vessel Occlusion (ELVO), often treated with MT, can lead to further complications such as HC. Little is known about predicting the risk and extent of HC. FGF‐21 and 23 are angiogenic proteins of the endocrine subfamily and are independent factors for overall risk of stroke and intracranial hemorrhage (PMID: 33967812). Comorbidities such as diabetes, obesity, hypertension, and hypercholesterolemia are also known to increase risk of HC and affect FGF levels.

Methods

The Center for Advanced Translational Stroke Science at the University of Kentucky utilizes the Blood and Clot Thrombectomy Registry and Collaboration (BACTRAC) protocol (www.clinicaltrials.gov NCT03153683) for collection of systemic (i.e. proximal to thrombus) arterial blood during a MT procedure. Blood samples collected from 61 patients were sent to Olink Proteomics for proteomic analysis. The European Cooperative Acute Stroke Study (ECASS II) grading system was used to differentiate between the types of HT: Hemorrhagic Infarction (HI 1 and 2) and Parenchymal Hemorrhagic Infarction (PH 1 and 2). Logistic regressions were used to determine the association of FGF with the subtypes of hemorrhagic conversion. Data analyses were performed using IBM SPSS Statistics.

Results

FGF‐21 and FGF‐23 were significantly higher in patients with HI versus PH‐type HC (p=0.043 and p=0.004 respectively). Logistic regression yielded a significant model for only FGF‐21 (χ2= 5.196, p=0.023). Increasing levels of FGF‐21 were associated with a decreased likelihood of having PH‐type HC. Most patients receiving TPA had decreased levels of FGF‐21 (p=0.04). Various comorbidities were tested but were not found to be significant.

Discussion

The data provides an indication that lower levels of FGF‐21 increase the odds for a worse type of hemorrhagic transformation. Lower levels of FGF‐21 are reported in patients with hypercholesterolemia and hypertension. Our study found TPA correlated with lower levels of FGF‐21. Taken together, patients with comorbidities that decrease FGF‐21 levels, such as hypertension and hypercholesterolemia, and those who receive TPA should be monitored more carefully following thrombectomy. FGF‐21 should be evaluated further as a potential biomarker for hemorrhagic transformation to administer adjunctive therapies to MT.
Sex Differences in Vascular Endothelial Function After Liver Transplant
Authors: Chavez Domenico A. , Bohmke Natalie J. , Martin Linsey , Miller Austin , Bhati Chandra , Wolver Susan , Siddiqui Mohammad S. , Kirkman Danielle L.
Published: May 2022

INTRODUCTION

Liver transplant (LT) recipients have an increased risk of developing cardiovascular disease (CVD) after transplant. Sex differences may be a significant determinant in the pathophysiology of CVD. However, sex‐differences in vascular dysfunction, an established precursor to CVD, have not been explored in LT recipients. The purpose of this study was to investigate the sex differences in vascular function and cardiometabolic risk‐factors to CVD among LT patients.

METHODS

Conduit artery endothelial function was measured via flow‐mediated dilation of the brachial artery (FMDBA) with duplex ultrasound in 23 age‐matched LT patients (11 Male, 12 Female; Mean ± SEM: Age 55 ± 2 years). Aortic pressure waves were synthesized from radial artery waveforms acquired by applanation tonometry and the use of a generalized transfer function. Novel plasma based cardiometabolic risk factors were assessed with nuclear magnetic resonance spectroscopy. Lipoprotein insulin resistance index (LPIR) was calculated as a weighted combination of concentrations and particle sizes of very low‐density, low‐density, and high‐density lipoproteins. Diabetes risk index (DRI) factors LPIR and branched‐chain amino acid levels to predict the risk of type 2 diabetes. Metabolic inflammation index (INFX) combines concentrations of the inflammation biomarker GlycA and high‐density lipoprotein particle subspecies.

RESULTS

Males had lower FMDBA than females (3.98 ± 0.63 vs 6.27 ± 0.43%, p < 0.01). There were no sex differences in aortic systolic pressure (Male vs Female; 129 ± 3 vs 118 ± 5 mmHg, p = 0.09), body mass index (38 ± 2 vs 36 ± 2 kg/m2, p = 0.61), LPIR (57 ± 7 vs 55 ± 7, p = 0.89), DRI (53 ± 7 vs 44 ± 6, p = 0.38), or INFX (47 ± 2 vs 54 ± 3, p = 0.13).

CONCLUSIONS

Males had poorer vascular endothelial function compared to females following LT, suggesting that males may be more susceptible to the development of CVD after LT. However, this increased risk cannot be explained by differences in traditional cardiometabolic risk factors. Future research should identify non‐traditional CVD risk factors that contribute to sex differences in vascular function towards implementing precision medicine for the prevention and management of CVD in LT patients.
Spatially encoded GPCR signaling depends on the precise subcellular positioning of receptor‐containing endosomes
Authors: Willette Blair K. A. , Tsvetanova Nikoleta
Published: May 2022

G protein‐coupled receptors (GPCRs), which comprise the largest class of drug targets, are critical signaling proteins that translate extracellular stimuli to mediate human physiology. As such, understanding GPCR signaling cascades will provide insight into the molecular processes underlying complex physiologies, how these are perturbed in disease, and inform our ability to design more efficient therapeutics. In recent years, our lab and others have made the paradigm‐shifting discovery that GPCRs can be activated after drug‐induced internalization into endosomal compartments to generate spatially biased responses. We have found that transcriptional signaling downstream of GPCR activation is initiated strictly from intracellular receptors. However, it remains unknown how the endosome can promote such selective signaling outcomes. One possibility is that the biophysical positioning of endosomal GPCRs within the cell, specifically their proximity to the nucleus, may allow for cAMP signaling cascades that result in gene transcription. To address this, I devised a strategy to rapidly redistribute endosomes in intact cells and coupled the approach with two novel microscopy‐based optical transcriptional readouts. Specifically, I developed and optimized a chemically induced heterodimerization system that fuses endosomal embedding proteins to plus‐ or minus‐end directed molecular motors and allows their relocalization ‘on command’. To determine the impact of endosomal redistribution on transcription, I utilized either accumulation of a fluorescent cAMP transcriptional reporter or single‐molecule RNA in situ hybridization of endogenous target genes. With these complementary readouts, I show that redistributing receptor‐containing endosomes toward the cell periphery significantly inhibits GPCR‐mediated gene transcription without perturbing the biochemical composition of the endosome. In an orthogonal approach, I utilized localized optogenetic adenylyl cyclases to demonstrate that cAMP produced at or proximal to the cell periphery similarly failed to induce transcription. Lastly, I uncovered that this critical role of endosomal positioning stems in part from enhanced PDE activity around the plasma membrane. This study supports a key role for endosomal positioning in the transduction of the GPCR‐initiated signal. Ultimately, this work helps dissect what makes the endosome a unique signaling compartment and illuminate the molecular mechanisms underlying spatial selectivity of GPCR signaling.
An Electrochemical Biosensor for Detection of P.69 Pertactin Associated with B. pertussis
Authors: Allen Marissa , Bonham Andrew J.
Published: May 2022

Whooping cough caused by Bordetella pertussis can cause serious and prolonged health effects and is especially deadly in infants. Early treatment can significantly reduce the duration of illness and lead to better outcomes, but current diagnostic procedures need a relatively large patient sample and have an extended wait period for testing results. There is thus a pressing need for quick and accurate diagnosis. In response, we are developing an electrochemical DNA‐based (E‐DNA) biosensor for the rapid detection of B. pertussis. Our biosensor utilizes a DNA aptamer that targets P.69 pertactin, a well‐known adhesion factor in the outer membrane of B. pertussis. To generate this aptamer, we first obtained purified P.69 pertactin and biotinylated it. Biotinylation extent was measured via HABA assay and showed ~ 42 biotin molecules per P.69 pertactin molecule. This biotinylated protein was used for selection in a modified SELEX (systematic evolution of ligands by exponential enrichment) process, followed by high‐throughput sequencing. That analysis discovered six aptamer sequences with potential strong binding for P.69 pertactin. Potential aptamers were synthesized, and binding was confirmed via fluorescence anisotropy and gel shift assays. These techniques identified one aptamer sequence as having strong, low‐nanomolar binding affinity for P.69 pertactin. This aptamer was then computationally analyzed for likely secondary and tertiary structures, allowing identification of the minimum binding unit, and then was modified to generate a two‐state binding system. This modified aptamer sequence serves as the basis for an electrode‐tethered E‐DNA biosensor. This design will be verified against purified P.69 pertactin standards as well as B. pertussis isolates to demonstrate its potential as a rapid and accurate diagnostic biosensor for whooping cough infections.
Understanding the Structural Requirements for Hemolytic Protein Function
Authors: Massman Lilyanna , Grilley Dan
Published: May 2022

We study the hemolytic activity of a hemolysin protein (HpmA) secreted by the gram negative bacterium Proteus mirabilis. HpmA is the A component of a type Vb, or two‐partner, secretion pathway (TPS pathway). To cross the outer membrane, unfolded periplasmic HpmA is recognized, exported, and folded by its membrane bound cognate B component. Once secreted, HpmA displays cytotoxic activity against mammalian cells, including red blood cells. HpmA is comprised of 1577 amino acids and contains at least two functional domains – a TPS domain that targets the protein to the correct B component and a hemolytic domain. Less than 20% of the HpmA structure is known, and none of the hemolytic domain structure is known. To address this problem, we used quantitative hemolytic activity assays to determine the contributions to protein function made by different segments of the hemolytic domain. Our data show a reduction but not elimination of function as the protein is progressively truncated. We have developed two models that could explain these results – an Assembly model and an Association model that differ in the stoichiometry of HpmA needed to lyse a red blood cell. The applicability of these models to different HpmA truncations and the implications for HpmA biological structure and function are discussed.
Pharmacological effect of pinostrobin on CFTR‐mediated Cl‐ secretion and renal cyst development in in vitro model of polycystic kidney disease
Authors: Tonum Kanlayanee , Soodvilai Sunhapas
Published: May 2022

Cystic fibrosis transmembrane conductance regulator (CFTR) plays crucial role in renal cyst expansion via increase in fluid accumulation. Evidence suggests that inhibition of CFTR retard cyst development and enlargement in polycystic kidney disease (PKD). Here we investigated the pharmacological effect of pinostrobin, a bioactive natural flavonoid on CFTR‐mediated Cl‐ secretion and renal cyst expansion in in vitro model; human autosomal dominant polycystic kidney disease (ADPKD) cell line and Type I Mardin Darby Canine Kidney (MDCK) cells. Treatment with pinostrobin (10 and 50 µM) significantly reduces MDCK cyst formation and enlargement in concentration‐dependent manner. Pinostrobin reduces the number of renal cyst colonies corresponding with a decrease in cell proliferation and extracellular signal‐regulated kinases (ERK) signaling. Additionally, pinostrobin retarded cyst expansion via inhibition on CFTR‐mediated chloride secretion. The inhibitory effect of pinostrobin was not due to the decrease in cell viability and activity of Na+‐K+‐ATPase. Our findings define that pinostrobin might be the candidate for further study as the therapeutic agents for PKD treatment.
Knowledge of anatomical variants in teachers of private universities in Santiago de Chile
Authors: Nova Baeza Pablo I. , Valenzuela Juan J. , Gold Marjorie , Bruna Alejandro , Orellana Mathias
Published: May 2022

Introduction

Human Anatomy is one of the pillars for the training of professionals in the health area, which generates a great challenge for the curricular profile of the teachers who teach these courses, this in relation to the different profiles proposed by each career of the health in which human anatomy is taught, where many times this must be at the service of curricular preferences and graduation profile of each career, hence well‐prepared teachers both in normal anatomy and in anatomical variants can contribute in the anatomical and later clinical training of these students. If we talk about the knowledge of anatomical variations, remember that this is defined as a change in the normal anatomy that presents an incidence in the population of no more than 10%, since, if this incidence increases, the most appropriate term to define this condition is variability. anatomical.

Methodology

This descriptive‐observational study searched through a questionnaire of eight questions, based on seven images taken from VH Dissector Pro plus a dichotomous question, which was applied to teachers of private universities in Santiago de Chile, where these They agreed to participate voluntarily through a google form. The data obtained were analyzed by the research group through the statistical method of Shapiro Wilk.

Results

After having surveyed 33 teachers, the results found were as follows: The percentage of the results obtained was that 0% of the participants obtained 7 points, 12% obtained 6 points, 15% obtained 5 points, 9% obtained 4 points, 36% obtained 3 points, 21% obtained 2 points, 3% obtained 1 point and 3% obtained 0 points. Regarding the gender of the participants, there was no statistically significant difference in the score obtained (p = 0.21). Finally, regarding the relationship between the score and the years of teaching experience in human anatomy, a statistically significant difference was not found in favor of teachers with more years of experience (p = 0.13).

Conclusion

In relation to the results found in this study, we can affirm that many of the surveyed teachers do not have the knowledge of anatomical variants proposed in a virtual corpse, which calls us to pay attention to the fact that teachers should refine this probability of anatomical variation in their study or curricular profile, which can allow that by having a greater management of these variations they can transmit them to their students and with this make not only normal anatomy important, since clinically it has been reported that there are different anatomical variables that could have an incidence in the clinical area in any age range.
Conservation of Kidney Development in the Red‐eared Slider, Trachemys scripta
Authors: Boehler Hannah C. , Donohue James , Hiley Jessica , Lisonbee Kasen , Camarata Troy
Published: May 2022

Mammals, birds, and reptiles all possess a metanephric kidney in adult animals. The process of kidney development, or nephrogenesis, ceases in mammals prior to or immediately after birth. Termination of mammalian nephrogenesis is due to kidney progenitor cell populations halting self‐renewal and undergoing terminal differentiation. Our previous studies have shown in several reptile species the presence of post‐embryonic nephrogenesis accompanying embryonic‐like adult progenitor cells. It is unknown how or why kidney progenitor cell populations are lost during mammalian development but persist in reptiles. To better understand the persistence of kidney progenitor cells in reptiles, we have set out to characterize kidney development to determine if adult progenitor cell populations are a continuation of embryonic processes. We have chosen to use the red‐eared slider turtle, Trachemys scripta, as a model for reptile metanephric kidney development as this species showed the highest number of nephrogenic zones in adults. While the embryonic development of external morphology (such as head, limbs, shell) in this species has been documented, organogenesis has not been studied as thoroughly. We have utilized gross observations of morphology, histology, whole‐mount immunohistochemistry and in situ hybridization to characterize and assess the conservation of kidney development in this species. The embryonic kidney progenitor cell marker, Six2, was detected as early as stage‐15 as a linear group of metanephric mesenchyme. Little to no cytokeratin positive epithelium was detected at this stage of kidney development. As kidney development proceeds, the progenitor mesenchyme cells and adjacent ureteric bud epithelium are found in highly organized rows. Several genes known to play roles within mammalian kidney development displayed conserved expression domains in the developing T. scripta kidney. The embryonically expressed Six2 transcription factor was also detected in progenitor cells of adult kidneys. Future investigation will continue to assess kidney ontogeny in reptiles.
Role of central irisin in the cardiorespiratory and metabolic control of adult rats
Authors: Bernardes‐Ribeiro Mariana H. , Patrone Luis Gustavo A. , Bícego Kênia C. , Gargaglioni Luciane H.
Published: May 2022

Irisin has been identified as an important exercise‐induced myokine that acts in different physiological systems; however, little is known about the participation of irisin in cardiorespiratory and basal metabolic control. Therefore, the present study evaluated the effect of intracerebroventricular (icv) injection of vehicle or irisin (IR, 0.425 µg/µL) in the fourth ventricle (4V) of adult male rats on the cardiorespiratory and metabolic control during wakefulness and sleep under room air, hypercapnia (7% CO2) and hypoxia (10% O2). Our data show a tendency of reduction in basal ventilation of IR group during wakefulness (VEH: 1056.2 ± 61.8 vs IR: 816.9 ± 30.5 mL.Kg‐1.min‐1), due to a reduction in respiratory frequency (VEH: 105.1 ± 5.3 vs IR: 85.9 ± 5.1 breaths.min‐1) and a consequent decrease in arterial partial pressure of O2 (VEH: 95.1 ± 2.4 vs IR: 88.7 ± 3.1 mmHg). No difference was observed in metabolic rate; however, central IR promoted a reduction in the air convection requirement (VEH: 57.2 ± 4.7 vs IR: 39.6 ± 3.7). Regarding the cardiovascular parameters, central injection of IR caused a significant increase in heart rate during hypoxia exposure (VEH: 342.5 ± 38.0 vs IR: 406.2 ± 16.8 beats.min‐1) without changing arterial pressure. These effects were only observed in awake conditions, with no changes evidenced during sleep. No difference in cardiorespiratory and metabolic parameter were observed under CO2 exposure after central IR injection. Therefore, our preliminary results suggest that IR caused a hypoventilation under room air conditions, possibly due to a lower ventilation, increased heart rate under hypoxic conditions, suggesting that this myokine also acts in the central nervous system to modulate breathing and cardiovascular parameters.
Downregulation of Angiotensin Type 1 Receptor by Ferulic Acid in Rat Liver Epithelial Cells
Authors: Cravens Ellen , Thekkumkara Thomas , Yesudas Rekha
Published: May 2022

The renin‐angiotensin system plays a key role in the regulation of cardiovascular functions through the angiotensin type‐1 receptor (AT1R), particularly in the control of hypertension. Previous studies have shown that plant‐derived polyphenols appear to provide protection against cardiovascular diseases. However, the target or mechanism(s) involved in the protective effects of polyphenols remains unclear. Ferulic acid is a naturally occurring plant derived polyphenol with anti‐inflammatory and cardioprotective properties. We hypothesized that ferulic acid would have a pivotal role in the regulation of AT1R expression and function. In the present study, we investigated the effects of ferulic acid on AT1R expression. We used a continuously passaged rat liver epithelial cells (WB) with high levels of native AT1R expression. Cells were cultured to 80‐90% confluency and exposed to ferulic acid to determine cell viability, cell count, cell size and AT1R receptor expression. Exposure of the cells to 10□g/ml ferulic acid (IC50 concentration) resulted in a significant downregulation of AT1R cell surface expression (Figure). Consistent with the cell surface receptor downregulation we observed downregulation of immature AT1R protein in the cytosol, suggesting the downregulatory effect of ferulic acid is mediated through gene transcription. Under similar conditions, we observed no change in cell morphology, count, or total protein content. Cell viability assay and cell size assessment also indicated that ferulic acid treatment was not affecting the normal growth of these cells. Although further studies are needed to confirm these initial observations, our study demonstrated for the first time that ferulic acid inhibits the AT1R expression in WB cells demonstrating a role for polyphenol in hypertension control in part through AT1R downregulation.