bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Acute Hypocapnia and Respiratory Alkalosis on Neurovascular Coupling Magnitude
Authors: Ciorogariu-Ivan Anna-Maria , Bader Taylor , Keough Joanna , Donald Joshua , Leacy Jack K. , O’Halloran Ken D. , Wilson Richard J. , Jendzjowsky Nicholas , Day Trevor A. 
Published: April 2020

The brain requires well‐regulated cerebrovascular perfusion to match local metabolic demand. Regional coupling of perfusion to metabolic rate is termed neurovascular coupling (NVC). NVC remains stable during blood gas perturbations upon ascent and acclimatization to altitude, where individuals are exposed to antagonistic effects of hypoxia (vasodilation) and hypocapnia (vasoconstriction), where acid‐base variables are likely well‐compensated. Few studies have addressed the effects of acute hypocapnia and respiratory alkalosis independently. The aim of this study was to assess the specific effects of acute steady‐state hypocapnia on NVC magnitude in a laboratory setting. We recruited 10 healthy participants and instrumented the posterior cerebral artery (PCA) with a transcranial Doppler ultrasound. NVC was elicited using a standardized strobe light stimulus (6 Hz; 5×30sec on/off), and both peak and mean absolute responses from baseline (BL) were quantified. Participants were coached to hyperventilate to reach steady‐state hypocapnic steps of Δ‐5 and Δ‐10 Torr end‐tidal (PET)CO2 from baseline levels. PETCO2 levels were significantly decreased from 36.7±4.2 (BL) to 31.0±5.1 and 25.9±5.4 Torr (P<0.05), with estimated arterial pH(a) values of 7.43±0.05 (BL), 7.47±0.08 (Δ‐5) and 7.59±0.11 (Δ‐10), respectively (P<0.05). There was a significant reduction in NVC magnitude from BL (10.2±2.5 cm/s) during controlled hypocapnia at both Δ‐5 (8.3±2.6 cm/s) and Δ‐10 (8.1±2.7 cm/s) in peak PCA velocity (PCAv) (P<0.05), but no significant decrease in mean PCAv (P>0.05). Our study demonstrates that acute respiratory alkalosis attenuates peak NVC magnitude with a floor effect at Δ‐5 Torr PETCO2 (~7.47 pHa), without further attenuation at Δ‐10 (~7.59 pHa). This is one of few studies demonstrating a change in NVC with acute blood gas challenges. However, the effect is small and only observed in peak PCAv responses, with no differences between mild and more severe respiratory alkalosis.Support or Funding InformationMRU Faculty of Science and Technology, University College Cork, University of Calgary
Determining the Role of Extracellular Matrix Compliance on Facial Morphogenesis
Authors: Hanne Nicholas Jean , Hu Diane , Linde-Medina Marta , Hallgrimsson Benedikt , Marcucio Ralph S. 
Published: April 2020

We have previously found that collagen 4 and laminin are thinner in regions of the frontonasal process undergoing growth, suggesting tissue compliance may contribute to regulation of facial morphogenesis. Lysyl oxidase (LOX) initiates enzymatic crosslinking of collagen and elastin. Crosslinking in extracellular matrix fibrils increases tissue stiffness and may constrain growth in certain directions while allowing cells to exert forces required for directional growth. Our goal was to examine the distribution of lysyl oxidase in the frontonasal process (FNP) of chick embryos during growth and fusion of the palate. At Hamburger and Hamilton stage 22, LOX is present in the ectodermal basement membrane along the FNP, but at stage 26 it is present primarily in the basement membrane lining the nasal pits. LOX is also present in the lateral edges of the mesenchyme of the FNP at stage 22, but is more present in the medial and caudal mesenchyme at stage 26. These results mirror the distribution of collagen 4 and laminin, where more crosslinking was observed in regions resisting growth (like the nasal pits) and in regions where cellular forces may be generated to direct growth (ectodermal basement membrane). We next prevented initiation of crosslinking with a small‐molecule from Lathyrus odoratus, beta‐aminoproprionitrile (BAPN), which permanently binds to LOX. Ingestion of L. odoratus causes osteolathyrism, a musculoskeletal degenerative disease, and researchers have found that BAPN administered in high concentrations to embryos causes skeletal and craniofacial deformities. We found that microinjections of BAPN in the caudo‐lateral edge of the FNP at low concentrations (50, 75, and 100 ng/uL) caused mild truncation of the FNP without affecting LOX localization or increasing cell apoptosis (via TUNEL staining). Together, these results provide preliminary evidence that tissue compliance may play an important role in facial morphogenesis. Future work will utilize a LOX RNAi vector to further examine the role of extracellular matrix crosslinking on palate growth and fusion.Support or Funding InformationFunding was provided by: CIHR, and NIH, NIDCR R21‐DE028198
Perception of the Chaldean Population Towards Whole Body Donation
Authors: Gappy Mavis , Barremkala Malli , Farr A. Celeste 
Published: April 2020

INTRODUCTIONThe use of human donors for anatomic dissection is a long‐held tradition in medical education. The majority of donors are Caucasian which leads to a lack of racial diversity among the body donors. The aim of this project is to determine the knowledge, attitude, and perception of the Chaldean population towards whole‐body donation. By understanding the perspectives of the Chaldeans relative to whole body donation programs, we may be able to explain their lack of participation in the donation programs.METHODSFocus groups were held to ascertain the participants understanding of the body donation process, willingness to donate, and influencing factors. Chaldeans over the age of 18 were invited to participate in the study. During the focus groups, audio recordings were collected for transcription and analysis of responses. They were recruited from the Southeast area of Michigan, which has one of the largest Chaldean communities in the country. Five focus groups have been conducted with a total of 30 participants between the ages of 18–50.RESULTSA majority of participants reported that they did not know about the whole‐body donation process and were more familiar with organ donation. They generally agreed that whole‐body donation is valuable for education yet they would prefer organ donation. For either donation type, they generally believed in the conspiracy theory that the healthcare worker would let them die to get their body or organs. The factors influencing their decision to donate are family, providing a benefit to society, religion, having a funeral, and being cremated. The participants were unsure whether Catholicism permits whole‐body donation or cremation (negative factor). The consensus among the groups was that they would never do whole‐body donation but might donate their organs.CONCLUSIONThe results reveal that participants are unwilling to participate in whole body donation programs mostly because of the lack of knowledge on the whole‐body donation process and a conflation with organ donation. Participants commented that they would be interested in more education regarding whole‐body donation. Anatomy dissection programs that are planning to improve diversity in their cadaver population should talk to Chaldean religious leaders to get a further understanding of the religious implication of whole‐body donation and engage in educational programs in the community that reflect and respect those views. Furthermore, education should explain the difference between whole‐body donation and organ donation and the benefits of these donations while also addressing the related conspiracy theory.
L‐Plastin, a Novel Regulator of Microglial Activation in Parkinson’s disease
Authors: Budge Kevin , Richardson Jason , Safadi Fayez 
Published: April 2020

Parkinson’s disease (PD) is the second most prevalent neurodegenerative disease worldwide behind Alzheimer’s disease. One prominent feature of PD is the marked loss of dopaminergic and motor dysfunction. Currently, there are no therapies to effectively slow disease progression. Neuroinflammation is a major contributing factor in neurodegeneration diseases including PD. Microglia, a type of glial cell, are primary regulators of neuroinflammation and these cells are capable of assuming activation states ranging from inflammatory to anti‐inflammatory and reparative. Thus methods to combat microglial inflammation or promote microglial anti‐inflammatory and reparative effects show promise as treatments to slow neurodegeneration. L‐plastin (LPL) is an acting bundling protein and other research has shown that LPL plays a role in osteoclast function, T‐cell activation, and it may be involved in the NLRP3 inflammasome activation in macrophages. It has been shown in osteoclasts, that LPL phosphorylation at serine 5 plays a role in sealing zone formation. Using a peptide inhibitor to block phosphorylation of serine 5 on LPL prevented sealing zone formation and inhibited osteoclast‐mediated bone resorption. Given the evidence that LPL may play a role in inflammasome activation in macrophages, we investigated if LPL may play a role in microglial activation. To assess the function of LPL in the microglial inflammatory response, we utilized qPCR, Western blot, and immunofluorescence techniques. We show here that lipopolysaccharide (LPS) treatment induces LPL phosphorylation at serine 5, as well as increased Lcp1 mRNA expression. Furthermore, using a TAT‐fused peptidomimetic inhibitor of LPL phosphorylation significantly reduced LPS‐induced inflammatory gene (Il‐1b, Il‐6, Tnfa) expression. For this study, an acute 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) mouse model was also used. Male (10‐week‐old) C57BL/6N mice were treated with four injections (one every two hours) of either saline or 15mg/kg of MPTP. Mice were then sacrificed two days after the last injection and striatum and hindbrain were isolated. Two days after MPTP treatment is when peak inflammation occurs in the brain. We found that Lcp1 mRNA expression was significantly increased in the striatum of MPTP‐treated mice compared to saline‐treated mice. These results suggest that LPL may play a role in the microglial inflammatory response, and that LPL inhibition may be a novel way to combat neuroinflammation and neurodegeneration. We are currently staining for phosphorylated LPL in the microglia of MPTP treated mice. Furthermore, we have obtained LPL KO mice to assess the in vivo function of LPL in mouse models of PD.Support or Funding InformationKent State University Biomedical Sciences
Striatal specific orphan GPCRs crosstalk with Dopamine D2 receptors to regulate cAMP signaling
Authors: Felsing Daniel E. , Zamora Joshua , Raval Sweta , Allen John A. 
Published: April 2020

The striatum is a subcortical brain region that performs vital functions including movement control, regulation of attention and is a critical component of the reward system. Current drug targets have displayed limited efficacy in treating striatal‐related diseases including for substance‐use disorders, schizophrenia and Parkinson’s disease. G protein‐coupled receptors (GPCRs) are valuable drug targets with ~35% of FDA approved medicines targeting these receptors. However, nearly 120 GPCRs remain orphan receptors, whose endogenous ligands, G protein signaling, and therapeutic potential are unknown. We previously conducted a comprehensive RNAseq genome‐wide survey of human tissue gene expression and identified several orphan GPCRs selectively expressed in the human striatum, namely, GPR6, 52, 88, 101, 139 and 149. Here we elucidate striatal orphan receptors that modulate G protein‐mediated cAMP signaling and examine potential signaling crosstalk between orphan receptors and dopamine D2 receptors (D2R). Biochemical and CRISPR/Cas9 knockout studies in human embryonic kidney 293 (HEK293) cells confirmed GPR6, 52 and 101 increased cyclic adenosine monophosphate (cAMP) via Gs/olf G proteins, while GPR88 decreased cAMP levels via Gi/o G proteins. Notably, when expressed alone, GPR6, 52 and 101 profoundly increased basal levels of cAMP, indicating these receptors are constitutively active. We hypothesized that GPR6, 52, and 101 may set the basal tone for cAMP that would allow robust function of the Gi/o‐coupled dopamine D2R to inhibit adenylyl cyclase and decrease cAMP. When expressed alone in HEK293 cells and without any stimulation to the adenylyl cyclase system, the cAMP inhibition window for the D2R and agonist quinpirole was minimal and difficult to reliably detect (~1000 light counts/sec, Glosensor assay). However, when the D2R was co‐expressed with either GPR6, 52, or 101, the assay window to inhibit cAMP for quinpirole was magnified by over 200X (200,000–500,000 light counts/sec), with agonist potency unchanged. These studies suggest that these striatal specific human orphan receptors may establish dynamic basal cAMP levels and this may facilitate inhibition of cAMP via Gi/o‐coupled receptors, such as the D2R. Our findings also suggest GPR6, GPR52 and GPR101 are potential drug targets to modulate cAMP signaling in striatal specific neurons, which may be therapeutic for treating several neurological and neuropsychiatric diseases.Support or Funding InformationNIDA T32 DA07287 (DEF) and RSGPT18‐ PhRMA Foundation (JAA).
Ultra‐Small Biomimetic Nanoparticles for Alzheimer’s Disease Targeted Drug Delivery
Authors: Tatiparti Katyayani , Rauf Mohd Ahmar , Sau Samaresh , Alzhrani R. , Iyer Arun 
Published: April 2020

IntroductionAlzheimer’s disease (AD) the most common form of dementia worldwide, that affects older population and the 6th leading cause of death in USA. The cost of care involved is about $234 billion. AD is marked by the presence of beta‐amyloid protein plaques outside neurons that leads to cell death and the accumulation of an abnormal intracellular neurofibrillar tangles of hyper phosphorylated τ (tau) protein. This undesired accumulation causes obstruction of nutrition and other essential molecules to the brain. There is no potential treatment in the clinic because of the lack of proper understanding of the pathogenesis, delivery challenges across the Blood‐Brain‐Barrier (BBB), and unfavorable immune responses.ChallengeIn the present research we are developing ultra‐small nanoparticles (USNPs), that are expected to (i) Enhance the circulation half‐life and minimize the side effect of therapeutics; (ii) enable transport of therapeutics across the BBB and promote their accumulation in the desired brain region; (iii) assist in reduction and clearance of beta amyloid plaques; and (iv) promote favorable immune response. In addition when USNPs are combined with an NIR‐dye it may function as a diagnostic agent. In order to test our hypothesis, we designed a new Lactoferrin (Lf) based USNP to target low‐density lipoprotein receptor‐related protein‐1 (LRP‐1) overexpressed in AD.ResultsThe TEM analysis showed well‐defined spherical Lf NPs with an ultra‐small size of ~ 20–30 nm that will allow efficient penetration/delivery across the BBB. Further, the data obtained from our preliminary studies in SH‐SY5Y and BV2 brain cells suggest a dose‐dependent cell uptake of DiD‐fluorescence labeled Lf NPs. The cytotoxicity assays on normal brain cells showed them to be safe/non‐cytotoxic with a cell viability around ~ 85–90%. Subsequently, Tauopathy was induced employing okadoic acid in SH‐SY5Y cells to mimic AD under in vitro conditions. This was followed by testing of various combinations of the protein kinase inhibitors to assess the efficacy of the combination therapy on the hyper phosphorylation of Tau protein (pTau) in the brain cells. We also developed conditioned BBB cell culture model to demonstrate the penetration of Lf USNP across the BBB. Our IHC data reveal that it can be used to deliver combination of protein kinase inhibitors into the brain to reduce the tau tangle formation. Thus far, our hypothesis is being supported by the observed results.ConclusionThe preliminary results looks very promising in the direction of AD combination therapy. The outcome for our study protend to provide a strong rationale to employ Lf USNPs to overcome the BBB for improved AD targeting of the drugs, leading to better therapy outcome.
How Comparable are 2D and 3D Methods for Measuring Bone Laminarity in Developing Pigeons?
Authors: McGuire Rylee S. , Brown Alexandra , Jonglertjanya Kittaporn , Simons Erin L. R. , Lee Andrew H. 
Published: April 2020

The cortical bone of birds contains microscopic tunnels called vascular canals, which can be classified based on orientation as: longitudinal, radial, oblique, or circumferential. Circumferential canals are hypothesized to reflect adaptation to flapping flight. This hypothesis is supported by histological surveys of birds that show the proportion of circumferential canals (laminarity) is elevated in bones thought to experience habitual torsional loads. However, the most detailed data on torsional loading during avian flight is from the pigeon, a species in which the adults show low wing bone laminarity. Nevertheless, there may still be support for biomechanical adaptation if the laminarity is greater in adults than in juveniles incapable of flight. Alternatively, if the pattern is reversed, laminar bone may simply be a juvenile trait.Laminarity has largely been analyzed using 2D histological sections, which may not accurately represent complex 3D structure. High‐resolution micro‐CT is an imaging technique that allows 3D reconstruction, providing greater accuracy and objectivity in the measurement of canal orientation. Here, we compare 2D and 3D methods to clarify how wing bone laminarity develops in pigeons.We sampled a growth series of four pigeons that were collected from a previous study. A cortical strip (1 × 3 mm) was cut from the right humerus, ulna, and radius of each bird. The strips were scanned with high resolution microCT. 3D analysis involved segmentation, autoskeletonization, and measurement of 3D canal orientation using Avizo. For 2D analysis, five evenly spaced orthoslices were digitally extracted from each strip. Canals were fitted with ellipses and trigonometric equations were used to approximate orientation. In both 2D and 3D methods, canals were categorized and laminarity was calculated. Principal components analysis was performed to convert highly correlated variables (i.e., mass, bone length, and section modulus) into principal components (PCs). The relationship between principal components and laminarity was assessed using beta regression modeling.2D analysis overestimates laminarity among juvenile specimens. Therefore caution is warranted when applying 2D analysis to complex canal networks. Nevertheless, both methods show that the laminarity of each element significantly decreases with maturity (PC 1). Therefore, torsionally loaded bone is not necessarily more laminar. It seems laminarity is influenced by additional factors that warrant further investigation.Support or Funding InformationCollege of Graduate Studies Intramural Funding (Erin L. R. Simons & Andrew H. Lee); Kenneth A. Suarez AZCOM Summer Research Fellowship (Alexandra Brown, Kittaporn Jonglertjanya, Rylee S. McGuire)
Regulation of TAZ Expression by Cyclic Stretch
Authors: Miranda Maria Zena , Turki Razan , Kuebler Wolfgang M. , Simmons Craig A. , Kapus Andras 
Published: April 2020

It is increasingly recognized that fibrosis‐related phenotype transitions (e.g. EMT and fibrobrolast‐myofibroblast transition) are brought about by the interplay between chemical (e.g. TGFβ) and mechanical (e.g. stretch) stimuli, which, in part, act through cytoskeleton‐regulated transcription factors. Among these, the Hippo effector TAZ and the Rho/actin‐regulated myocardin‐related transcription factor (MRTF) are TGFβ‐ and mechano‐sensitive transcriptional co‐activators, which play key roles in the pathogenesis of organ fibrosis. Previously we have shown a multilevel crosstalk between TAZ and MRTF. Moreover, we found that TGFβ is a strong inducer of TAZ protein and mRNA expression, an effect mediated by p38‐dependent MRTF activation, independent of a net nuclear translocation of MRTF or TAZ. These results revealed that, in addition to TAZ nuclear translocation, the regulation of TAZ expression (a hitherto poorly characterized process) is also a critical feature of fibrogenesis. Since mechanical stimuli are prominent inducers of fibrosis, we sought to determine if cyclic stretch impacts TAZ expression and to investigate the potential role of the RhoGTPase/MRTF signaling pathway in this process. Cyclic stretch (10%, 1 Hz) increased MRTF‐transcriptional activity, measured by a CArG box‐ (cis‐element for MRTF) containing luciferase reporter construct, between 3 and 6 hr in C3H10T1/2 cells. Overexpression of Rho family small GTPases (RhoA, Rac1 and Cdc42) known to be activated by stretch and to induce MRTF translocation, were sufficient to enhance the activity of a TAZ promoter luciferase reporter (TAZ‐Luc). Consistently, cyclic stretch increased TAZ protein and mRNA expression, and activated TAZ‐Luc. TAZ‐Luc activation was abolished by MRTF inhibition or the mutation of the CArG box within the reporter (mtTAZ‐Luc). The stretch‐induced activation of TAZ expression was a universal phenomenon, since similar effects were observed in Interstitial Rat Mesenchyme Cells (IRMC) and Human Pulmonary Microvascular Endothelial Cells (HPMEC) as well. Finally, since the redox‐regulator pirin was recently suggested to be an upstream regulator of MRTF, we checked its potential involvement in the regulation of TAZ expression. While CCT‐251236, a pirin‐binding compound abolished the TGFβ‐induced TAZ expression, pirin silencing failed to recapitulate this effect. This suggests that the drug has alternative targets and MRTF can be activated in a pirin‐independent manner. Taken together, our studies show that critical chemical and mechanical fibrogenic stimuli increase TAZ expression and MRTF is a key mediator of this effect, both via classic (Rho‐mediated, translocation‐dependent) and by “non‐canonical” (phosphorylation‐induced activation) mechanisms. We propose that the ensuing rise in TAZ expression potently accelerates and exacerbates fibrogenic phenotype transitions.Support or Funding InformationKidney Foundation of Canada and Natural Sciences and Engineering Research Council of Canada (AK)