bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating a novel role of LARP along the algal TOR pathway
Authors: Slone Danielle R. , Smythers Amanda L. , Hicks Leslie M. , Kolling Derrick R. 
Published: May 2022

Over the last few decades, global warming has become an increasingly desperate rallying cry for the need to find and optimize efficient renewable energy sources.1 Microalgae are considered apromising source of energy because they contain a high concentration of lipids, but due to inefficiencies in their lipid production, microalgae cannot produce enough biofuel to replace current fuel needs.2Chlamydomonas reinhardtiiis a unicellular green alga that is a great candidate for manipulation and an excellent model organism used to better understand algal metabolic pathways and improve biofuels. Our previous research has shown that inhibiting the target of rapamycin (TOR) kinase of C. reinhardtii with AZD8055 causes the growth of the cell cultures to stagnate, the photosynthetic efficiency to decrease, as well as a direct link between oxidative signaling and the upregulation of TAGs.3 Additionally, our work has indicated that La‐related protein 1 (LARP1) is a TOR target and involved in propagating the intracellular response following inhibition. In mammalian systems, LARP1 interacts directly with mTOR and regulates protein synthesis by binding and stabilizing mRNA before recruiting polysomes to initiate translation. LARP1 is essential in mammalian systems, and deficiencies lead to inhibited growth, defects, and increased apoptosis. However, LARP1 deficiency in C. reinhardtii does not cause the same phenotype, indicating a distinct uncharacterized role in phototrophic organisms.This study seeks to understand this role by using a LARP1 knockout mutant to compare the physiological changes following inhibition with the parent strain. Both strains were assessed for biochemical composition, cell size, and photosynthetic electron fluxes. Together, these data support LARP1 as a regulator of protein degradation along the TOR pathway. The differential delineation of metabolic processes in LARP1 knockouts provides a framework for further TOR pathway characterization in phototrophic eukaryotes.Literature References1 IPCC, 2014: Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, R.K. Pachauri and L.A. Meyer (eds.)]. IPCC, Geneva, Switzerland, 151 pp.2 Sharma, Kalpesh K., Holger Schuhmann, and Peer M. Schenk.. High Lipid Induction in Microalgae for Biodiesel Production. 2012. Energies. 5:1532‐1553.3 Ford, M. M., Smythers, A. L., McConnell, E. W., Lowery, S. C., Kolling, D. R. J., & Hicks, L. M. (2019). Inhibition of TOR in Chlamydomonas reinhardtii leads to rapid cysteine oxidation reflecting sustained physiological changes. Cells, 8(10), 1171.
Fatty Acid‐Binding Proteins Respond Differently When Interacting with Endogenous Cannabinoids under High Pressure
Authors: Rosario Irving , Azad Roksana , Lai May Poh , Gagne Donald , Wang Hsin , Katz Francine S. , Gardner Kevin H. , Stark Ruth E. 
Published: May 2022

Liver‐type and intestinal fatty acid‐binding proteins (LFABP and IFABP, respectively) are both located in enterocytes, but their different functions are demonstrated by phenotypic differences observed in knockout mice for either protein. Though the two proteins are structurally similar, they differ significantly in their ligand‐binding cavities. The region of a protein with the greatest conformational variability is often found in the area surrounding the ligand‐binding cavity to enable an induced fit to a specific substrate. We used solution NMR spectroscopy while applying increasing pressure to investigate the interaction of these two proteins with ligand, in the hopes of capturing transient intermediate conformations of the protein and to identify potential on‐pathway states for substrate binding that would not otherwise be seen under standard conditions.Our initial experiments showed apo‐ and ligand‐bound IFABP remains stable under increasing pressure, up to 2500 bar. In contrast, apo‐LFABP and LFABP with anandamide completely unfolds at 1750 bar. Interestingly, the presence of oleate and arachidonic acid stabilizes LFABP, making it resistant to unfolding at high pressure. Our results show that this stabilization is ligand specific, correlating with the ligand binding affinities we determined previously. This trend suggests that specific protein/ligand interactions within the cavity are required for stability.To make a more detailed analysis of which residues are involved in binding, we generated plots of the pressure‐dependence of backbone 15N and 1H chemical shifts of LFABP and IFABP in either apo‐ or holo‐ form. Two regions of the protein were most responsive to changes in pressure as assessed by the nonlinear chemical shifts changes: i) the conformationally flexible portal and ii) a region of the ligand‐binding cavity we had previously reported as involved in the specificity of binding endocannabinoid ligands. This finding is consistent with the requirement of the conformational variability in these regions for ligand binding. We are currently performing a comprehensive analysis of these effects for the interaction of both proteins with a range of structurally related endogenous cannabinoids.
NVS‐HD1 preserves the mitochondria function and increase glucose uptake in C2C12 myoblasts exposed to lipopolysaccharide (LPS)‐induced inflammatory response
Authors: Wang Jianguo , Zhao Thomas , Slate‐Romano John , Zhao Ting C. 
Published: May 2022

BackgroundHistone deacetylase plays a crucial role in modulating cellular survivals and metabolism. Specific HDAC isoform in the regulation of mitochondria function and glucose hemostasis in lipopolysaccharide (LPS)‐induced inflammatory response remains to be determined. We examined the effects of a newly synthesized HDAC4 inhibitor, NVS‐HD1 on cell survival and mitochondrial function in differentiated C2C12 cells.MethodsC2C12 myoblasts were cultured in DMEM medium until 80% confluency before they were subjected to differentiation medium containing 2% horse serum for 3 consecutive days. C2C12 derived myotubes were then exposed to LPS at the concentration of 10 ng/L for 24 hours. NVS‐HD1 (10 nmol/L) and vehicle (Dimethylsulfoxide, DMSO) were treated in differentiated C2C12 cells with or without LPS to define the effect of HDAC4 inhibition on mitochondrial function and glucose uptake.ResultsDifferentiated C2C12 cells decreased viability in response to LPS stress as evident by and lactate dehydrogenase leakage and 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide MTT assay. LPS‐induced inflammatory attenuated glucose uptake as comparted to vehicle control. Furthermore, differentiated C2C12 cells displayed an impairment in mitochondrial function by decreasing mitochondrial membrane potential assessed by utilizing the red‐fluorescent probe TMRM (tetramethylrhodamine, methyl ester). As compared to DMSO treatment, NVS‐HD1 resulted in improvement in cell survival rate and increased glucose uptake, in association with the preservation of mitochondria function in LPS‐induced inflammatory response.ConclusionOur finding is the first demonstration that specific HDAC4 plays a pivotal role in preserving cellular survival, glucose uptake and mitochondrial function in LPS induced inflammatory response.
Direct Observation of Na,K‐ATPase Oligomers in The Plasma Membrane of Living Cells by FRET‐FCS
Authors: Nordahl Linnea , Wennmalm Stefan , Jönsson Jakob , Elsässer Simon , Akkuratov Evgeny E. , Brismar Hjalmar 
Published: May 2022

The sodium pump, Na,K‐ATPase, is an integral plasma membrane protein, expressed in all eukaryotic cells. Na,K‐ATPase transforms chemical energy from ATP into a gradient of Na+ and K+ over the plasma membrane by actively exporting three Na+ ions and importing two K+ ions for each hydrolyzed ATP. It is responsible for maintenance of the transmembrane Na+ gradient and is the major determinant of the membrane potential. It provides the driving force for all Na+‐coupled transport processes, thereby controlling essential functions in the cell. Na,K‐ATPase is formed by three subunits alpha/beta/FXYD, where alpha is the catalytic ion‐transporting subunit, beta is a regulatory subunit and FXYD is accessory.Self‐interaction and oligomerization of the Na,K‐ATPase alpha/beta heterodimer in cell membranes has been proposed and discussed for a long time but is still an open question.Here we have used a combination of FRET and Fluorescence Correlation Spectroscopy, FRET‐FCS, in order to detect oligomers of Na,K‐ATPase. Compared to conventional cross‐correlation FCCS, FRET‐FCS is one to two orders of magnitude more sensitive when detecting oligomers. Moreover, FRET‐FCS is inherently insensitive to unbalanced labeling, which is a great advantage during live cell measurements.We hypothesized that Na,K‐ATPase can exist in a higher order oligomeric state and demonstrate the use of FRET‐FCS to test this hypothesisWe have introduced fluorescent labels by using expression of non‐canonical amino acid modified beta subunits. The FRET pair Alexa488 and Alexa647 was directly conjugated to the beta subunits using selective click chemistry. Conventional FCS measurements of labeled cells revealed the absolute density of labeled and unlabeled Na,K‐ATPase. With FRET‐FCS we could observe FRET signals and FCS curves demonstrating the existence of oligomers. Positive controls for the FRET‐FCS measurements were constructed by labeling alpha subunits with Alexa488 and beta subunits with Alexa647.Furthermore, we performed Monte Carlo simulations of Na,K‐ATPase, as monomer and as oligomer of increasing order, together with its ligands in a picket and fence diffusion model of the plasma membrane. The simulations suggest that oligomerization can have an impact on the net efficiency of the Na,K‐ATPase measured as ATP turnover.In conclusion we find that Na,K‐ATPase can be found in the plasma membrane as oligomers. Further we discuss the consequences of oligomerization and propose that it can have a regulatory effect for the Na,K‐ATPase net efficiency.
Effect of Short‐Term Estradiol Exposure on Endothelin‐B Receptor‐Mediated Vasodilation in Postmenopausal Women
Authors: Welti Laura M. , Haigh Katherine M. , McGinty Shane J. , Del Vecchio Angelica R. , Edwards David G. , Wenner Megan M. 
Published: May 2022

Endothelin (ET)‐1 contributes to endothelial dysfunction in postmenopausal women (PMW) via the ETB receptor. We have previously shown that the ETB receptor mediates vasodilation in young women, an effect that is lost in PMW. However, it is unclear if ETB receptor‐mediated dilation can be restored in PMW exposed to E2.PURPOSETo test the hypothesis that E2 exposure restores ETB receptor‐mediated vasodilation in PMW.METHODSWe tested 9 PMW (55±2 yrs, 24±3 kg/m2, 91±5 mmHg) who self‐reported natural menopause and were at least 1 year without menses. We measured vasodilation in the cutaneous microcirculation via local heating using laser Doppler flowmetry coupled with intradermal microdialysis during perfusions of lactated Ringer’s (control), ETB receptor antagonist (BQ‐788, 300nM) and ETA receptor antagonist (BQ‐123, 500nM). Cutaneous vascular conductance (CVC) was calculated during the plateau phase of local heating (42°C), and normalized to maximal vasodilation achieved by perfusion of sodium nitroprusside (28mM) and heating to 43°C. All women were tested at baseline (BL) and after 7 days of E2 (Vivelle‐Dot, 0.1mg/day, transdermal patch) administration (+E2). A two‐way repeated measures ANOVA was performed to compare %CVCmax in PMW before and after E2 exposure. Data presented are mean ± standard deviation.RESULTSE2 administration increased serum estradiol (BL: 45±29 vs +E2: 71±42 pg/mL, P<0.01) and reduced follicle stimulating hormone (BL: 71±13 vs +E2: 57±17 pg/mL, P<0.01), but there were no changes in serum progesterone (BL: 0.57±0.93 vs +E2: 0.53±0.88 pg/mL, P=0.14) nor plasma ET‐1 (BL: 1.62±0.66 vs +E2: 1.54±0.54 pg/mL, P=0.42). E2 administration had no effect on cutaneous microvascular responses (Time P=0.41, Drug P=0.17, Interaction P=0.71). At BL, vasodilatory responses to local heating were not different during control and ETB receptor antagonism (control: 83±8 vs. BQ‐788: 88±6 %CVCmax). Similarly, vasodilation was not altered at BL during ETA receptor antagonism in a subset of women (n=6, control: 83±8 vs. BQ‐123: 87±8 %CVCmax). E2 administration did not improve vasodilation in the control site (BL: 83±8 vs. +E2 85±13 %CVCmax). Furthermore, there was no effect of E2 exposure on cutaneous vasodilatory responses during perfusion of ETB (BL: 88±6 vs. +E2: 89±6 %CVCmax) nor ETA (n=6, BL: 87±8 vs +E2: 92±7 %CVCmax) receptor antagonists.CONCLUSIONThese preliminary data suggest that short‐term E2 exposure does not modulate ETB receptor function in PMW. These findings are in contrast to our observations in young women demonstrating that ETB receptors mediate vasodilation in the presence of E2. The role of alternative therapies to modulate ETB receptor function should be considered in future studies.
Normalization of the α‐1Na/K‐ATPase Signalosome Rescinds Epigenetic Modifications in NASH‐Related Hepatocellular Carcinoma
Authors: Rajan Pradeep K. , Udoh Utibe‐ Abasi S. , Sanabria Juan D. , Nakafuku Yuto , Sodhi Komal , Pierre Sandrine V. , Xie Zijian , Shapiro Joseph I. , Sanabria Juan R. 
Published: May 2022

OBJECTIVEHepatocellular carcinoma (HCC) is one of the most aggressive human cancers and is characterized by an acquisition of multiple abnormal phenotypes driven by genetic and epigenetic alterations. Epigenetic changes including DNA methylation and histone modification are associated with uncontrolled cell growth and proliferation, and even initiation and progression of HCC from chronic inflammation with or without fibrosis in the liver. Among others, non‐alcoholic steatohepatitis (NASH) and alcoholic steatohepatitis (ASH) are two major risk factors as both of them may develop cirrhosis and hepatocellular carcinoma (HCC) if left untreated. Most of the existing clinical and experimental reports provide only a snapshot of abnormal histone modifications in HCC rather than their dynamic changes. This makes it difficult to elucidate the significance of these changes in the development of HCC. Therefore, the objective of the present study is to investigate the role of histone acetylation/methylation mediated alterations using in vitro cell line and high fat diet animal model of non‐alcoholic steatohepatitis (NASH)‐derived liver carcinogenesis.HypothesisMost of the existing clinical and experimental reports provide only a snapshot of abnormal histone modifications in HCC rather than their dynamic changes. Hence, the present study hypothesised that the histone acetylation/methylation disturbances mediated by the α‐1Na/K‐ATPase signalosome may help to elucidate the significance of these changes in the development of HCC.METHODSIn vitro studies were done using two human HCC cell lines, complemented with our in vivo murine models of NASH and NASH‐HCC. Experimental groups were exposed to pNaKtide, a selective α‐1 subunit signalling inhibitor. Acetylated/tri methylated H3K9 in cell lysates and liver homogenates were measured by ELISA, and their expression by confocal microscopy on immuno‐stained livers. Significant differences among groups were established at p<0.05 using ANOVA/t‐test.RESULTSEpigenetic changes in cell lines and liver malignancies correlated with morphological changes in NASH progression to malignancy. Acetylated and tri‐methylated H3K9 were significantly increased in untreated cells and livers when compared with pNaKtide treated cells and animals (p<0.05). Quantitative analysis of H3acetylK9 and H3tri‐methyl K9 proteins on confocal images from cells and livers confirmed our findings.CONCLUSIONSNormalization of the α‐1Na/K‐ATPase signalosome in human HCC cell lines and murine NASH‐HCC results epigenomic reprogramming.
Network mapping of asynchronous student interactions in online discussion boards
Authors: Downey Ryan 
Published: May 2022

The recent movement towards asynchronous learning activities in higher education has transformed student and educator interactions. However, as the efficacy of such approaches are unknown, many educators must rely on personal experience and peer anecdotes regarding student engagement without underlying data to inform assessment. As educators transition from pandemic‐driven pedagogy to sustainable models of course design, the use of course‐based analytics can help instructors understand the ways in which students are interacting with asynchronous activities and each other.To develop fluency in reading and understanding scientific journal articles and to provide an interactive forum for discussions between students, weekly discussion boards were assigned in a graduate‐level neuroscience course. Based on an assigned article, each student was required to post an original response to the reading and reply to two posts made by their peers. These discussion board interactions were analyzed to form a social network map of asynchronous student interactions. Of the 27 students initially enrolled in the course, 24 completed it. The 3 students that did not complete the course were included as nodes and edges but excluded from statistical analysis.During the 9‐week semester (9 original posts, 18 required peer replies), students responded well to instructions about ensuring that the majority of posts received peer interaction, with 91.5% of all original posts receiving at least one reply and 28.7% of posts receiving 3 or more replies. Prestige or indegrees, measured as the average number of replies each student received, was 17.96 (SD 6.39). Centrality or outdegrees, measured as the average number of replies each student made, was 17.92 (SD 1.64). Students connected to an average of 45% (SD 0.07) of their peers. There was no correlation between student quiz performance and either prestige or centrality. Students that tended to post earlier saw a non‐significant trend to receive more peer replies than those who tended to post later. This trend became significant (p < 0.001) when analyzing the correlation between absolute post order and number of replies rather than the average post order of each student.These findings provide evidence regarding student engagement behaviors as they pertain to online discussion boards. Students generally did not exceed the mandated minimums for full points, and in some cases, self‐reported through end‐of‐semester feedback that they strategically engaged either to maximize earned points or to minimize overall effort. Collectively, in their feedback, the students provided deep and nuanced feedback on the activity experience. Overall, while many students noted the time required and initial difficulty in regularly reading scientific literature, 92% of responses indicated that the student found value and utility in reading and discussing the scientific papers in this format, supporting the use of this activity in future versions of this course.
Novel HDL mimicking targeted drug delivery system for the treatment of Ewing Sarcoma
Authors: Sabnis Nirupama A. , Raut Sangram , Nagarajan Bhavani , Lacko Andras , Lothstein Leonard , Fudala Rafal 
Published: May 2022

PurposeSince their discovery as antitumor agents, anthracycline drugs such as doxorubicin have remained mainstays as an important class of chemotherapy for the treatment of a wide range of cancers including pediatric malignancies like Ewing Sarcoma (EWS). Unfortunately, their usage is limited due to cumulative dose‐dependent cardiotoxicity. Targeted drug delivery could be an important option to circumvent this problem.Experimental designOur laboratory has developed a novel reconstituted HDL drug delivery system comprised of Myristic acid conjugated Apo AI mimicking 5A peptide (Myr5A). We used a hydrophobic derivative of doxorubicin, N‐Benzyladriamycin‐14‐valerate (AD198) to engineer formulations of Myr5A‐AD198. Physico‐chemical characterization including size, zeta potential and entrapment efficiency was determined. Cytotoxic effectiveness of this formulation was tested in Ewing Sarcoma cells A673 and Cardiomyocytes, H9c2 in 2D and 3D spheroid model using CCK‐8 assays. Using Myr5A based formulation‐containing BODIPY; mechanism of uptake of payload was demonstrated by imaging. In addition, we investigated Biodistribution and payload retention in EWS tumors in xenograft NOG mice with EWS tumor model.ResultsFormulation of the Myr5A‐AD198 was stable and non‐leaky with payload entrapment efficiency of 47.6 ± 3.2%. The nanoparticles were spherical with average size of 47 ± 12 nm as observed by transmission electron microscopy (TEM). Cytotoxicity assays demonstrated that IC50 values of Myr5A‐AD198 formulation was 2.8 ± 0.4 times more effective than free AD198 in EWS cells. On the other hand, 3 times more dose was required for Cardiomyocytes with Myr5A‐AD198 formulation as compared to free AD198. Blocking the Scavenger Receptor type B1 (SR‐B1) receptors, resulted in inhibition of the uptake of payload in Myr5A formulation. Subcutaneous injection of Myr5A‐IR 780 dye in xenograft NOG mice indicated the retention of payload for up to 72 hours in tumor.ConclusionThese preclinical studies indicated a great translational potential of Myr5A‐AD198 formulation for the treatment of EWS patients due to its selective uptake mechanism and cardio‐protective effect. Longer retention of the drug in tumors as well as lower dose requirement compared to free drug gives an additional advantage. In future, the Myr5A based technology shows promise for personalized treatment options in EWS and other type of cancers as well.
Femoral neck anteversion in Xenarthra
Authors: Harper Christine M. , McAfee Robert K. , Sylvester Adam D. , Goldstein Deanna M. , Almonte Juan , Cooke Siobhán B. 
Published: May 2022

Degree of femoral neck anteversion distinguishes extinct sloth genera from each other, particularly when analyzed in combination with femoral neck angle. These data have been previously analyzed using a comparative sample including only extant sloths, which limits functional interpretations. Here, we analyze both femoral neck anteversion and femoral neck angle broadly across Xenarthrans to reconstruct the locomotor behavior of extinct Caribbean sloths.Femora of four extinct sloth genera (n=49; Acratocnus; Megalocnus; Neocnus; Parocnus) and nine extant Xenarthra genera (n=63; Bradypus; Choloepus; Cyclopes; Dasypus; Euphractus; Myrmecophaga; Pridontes; Tamandua; Tolypeutes) were surface scanned. Morphological axes representing the femoral neck, shaft, geometric axis of the femoral condyles (GA), and maximum dimension of the femoral shaft cross section at 30% of whole bone length were extracted. Degree of femoral neck anteversion was calculated relative to both the GA and cross section axes. Femoral neck angle was additionally calculated as the angle between the femoral neck and shaft axes. Non‐parametric MANOVAs with post hoc multiple comparison tests were used to test how the genera differed when the angle of femoral neck anteversion and femoral neck angle were analyzed in conjunction.Parocnusdoes not significantly differ from any of the armadillo taxa when femoral neck angle is analyzed with either of the two anteversion angles (p>0.171 for all pairwise comparisons), supporting previous suggestions that Parocnuswas largely terrestrial. This finding also indicates that Parocnus may have had similar hindlimb biomechanics to armadillos, and possibly utilized digging behaviors. Megalocnusand Acratocnusdiffer significantly from all extant Xenarthrans (p<0.043 for all pairwise comparisons), but do not exhibit significantly different morphologies from each other (p=0.911). This suggests that the two genera may have utilized similar hip mechanics; however, their locomotor repertoires cannot be accommodated within the range of those exhibited by extant Xenarthrans.