bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ampakines Increase Spinal Respiratory Motor Output after Cervical Spinal Cord Injury in Rats
Authors: Streeter Kristi , Gonzalez‐Rothi Elisa , Sandhu Milap , Baekey David , Greer John , Fuller David 
Published: November 2023

Glutamatergic synaptic transmission is a fundamental component of the neural drive to breathe, and α‐Amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid receptor (AMPAR) mediated synaptic currents contribute to respiratory rhythmogenesis and respiratory motoneuron depolarization during inspiration. Ampakines are a class of synthetic compounds initially designed to enhance AMPAR‐mediated glutamatergic neurotransmission related to cognition, learning and memory. Ampakines are also a potent respiratory stimulant, particularly during conditions of suppressed respiratory motor output. While ampakines have been safely used in clinical studies, to our knowledge they have never been evaluated with respect to neurological disorders that compromise breathing, such as cervical spinal cord injury (SCI). Therefore, we aimed to test the hypothesis that ampakines increase respiratory motor output following cervical spinal cord injury. To test this hypothesis, we gave ampakine CX717 to urethane anesthetized rats (15–30 mg/kg, i.v.) with chronic (2–8 wks) cervical (C2) hemi‐section injury (C2Hx) or mid‐cervical (C3/C4) lateral contusion injury. In preliminary experiments, ampakines caused a rapid and robust increase in phrenic motor output ipsilateral to the injury and also increased contralateral phrenic motor output to a lesser extent. Responses were similar across time points post‐injury. In addition, we observed that i.v. ampakine caused a rapid change in the discharge of spinal interneurons below the spinal injury in the vicinity of the phrenic motor pool (C4). These initial results indicate that ampakine CX717 can stimulate respiratory motor output following cervical spinal cord injury, and also alters the activity of the mid‐cervical propriospinal network.Support or Funding InformationFunding: 1R01NS080180‐01A1 (DF) and 1F32NS095620‐01 (KS)
Impact of Free‐Living Nutrition Intervention on Microbiome in College Students at Risk for Disease: FRUVEDomic Pilot Study
Authors: Famodu Oluremi A , Cuff Christopher F , Cockburn Andrew , Downes Marianne T , Murray Pamela J , McFadden Joseph W , Colby Sarah E , Morrell Jesse S , Olfert I Mark , Olfert Melissa D. 
Published: November 2023

ObjectiveWe tested the hypothesis that an 8 week, free‐living nutrition intervention (emphasizing increased fruits and vegetables) in 18–28 year old college students “at risk” for Metabolic Syndrome (MetS) will result in significant changes in microbiome and improve health indicators.MethodsThirty‐seven subjects were recruited at West Virginia University and randomized into one of three groups: Half fruit & vegetables (“Fruved”); “Fruved” plus low‐refined carbohydrate (Fruved+LowCHO); and “Fruved” plus low‐fat (Fruved+LowFat). Venous blood and stool samples were collected pre and post intervention. Alterations in the fecal microbiome were assessed using high throughput sequencing.ResultsAll individuals significantly decreased empty calories (p<0.0001) and increased fiber (p<0.001) and cups of fruit and vegetable (p<0.0001) after 8 weeks, with no differences between groups. Improvements in weight, waist circumference, systolic blood pressure and body fat significantly decreased in all individuals (p<0.05, p<0.0001, p<0.01 and p<0.05 respectively). Additionally, insulin sensitivity improved (p<0.05) and total cholesterol decreased (p<0.05) after intervention. Alpha diversity was found across individuals, but no differences were seen across groups. Although not significant, individuals at “lower‐risk” for MetS at the beginning of the intervention had lower Bacteroidetes and higher Firmicutes than those considered “higher‐risk”. After the nutrition intervention, trends were seen with decreasing Bacteroidetes and increasing Firmicutes in all “at‐risk” groups, however there was no significant differences seen (p=0.109).Conclusions and ImplicationsSpecific profiles in phylum level microbiota for those considered “at‐risk” of MetS were identified, with individuals of “higher‐risk” having a higher Firmicutes to Bacteroidetes ratio before the intervention, typically associated with obesity and inflammation. Healthy diet produced significant microbiota changes in the “higher‐risk” versus “lower‐risk” for MetS and improved cardiovascular health in all individuals. Future analysis needs to include investigation at the family level of microbiome, as well as between treatment groups in order to identifying markers among “at risk” individuals which may help to direct precision medicine approaches and generate individually tailored nutrition prescription.Support or Funding InformationFunding provided by the WV Clinical and Translational Science Institute (NIH/MIGMS Award Number U54GM104942) and the WVU Mountains of Excellence Pilot Grant Program
Zinc and ZIP14 (Slc39a14) are Required for Adaptation to ER stress in Mouse Liver
Authors: Kim Min‐Hyun , Aydemir Tolunay Beker , Cousins Robert J. 
Published: November 2023

The accumulation of unfolded or misfolded proteins in the endoplasmic reticulum (ER) induces the unfolded protein response (UPR). UPR leads cells to adaptation against ER stress by improving protein folding capacity and by attenuating the translation of mRNA. However, if stress is too severe or cells fail to maintain cellular functions, ER stress‐mediated apoptosis is triggered. Zinc, an essential mineral, has been known to be required for normal ER function. Zinc restriction can induce the UPR in vitro, suggesting a role for zinc transport in ER stress. Zinc transporter ZIP14 (Slc39a14) is abundantly expressed in liver. ZIP14 transports extracellular and organellar zinc into the cytosol of cells. We found ZIP14 expression was highly increased in mouse liver by treatment with tunicamycin, a potent ER stress inducer. However, the precise roles of zinc and/or ZIP14 in the UPR are unclear. Here we report that Zip14−/− (KO) mice injected with tunicamycin had a higher apoptosis level with impaired adaptation to ER stress in comparison to wild type (WT) mice. During UPR activation, the liver of WT mice accumulated extra zinc. This response was not observed in KO mice. Zip14 KO mice expressed higher levels of ATF4 (Activating Transcription Factor 4) and CHOP (C/EBP homologous protein), proteins which are responsible for ER stress‐mediated apoptosis. In addition, Zip14 KO mice expressed lower levels of ER chaperones, such as GRP78 and GRP94, which help cells adapt to ER stress by improving protein folding ability. Furthermore, we injected WT mice with tunicamycin 2 weeks after feeding different levels of zinc: ZnD (<1mg Zn/kg), ZnA (30mg Zn/kg) or ZnS (180mg Zn/kg) to examine the importance of dietary zinc intake on the adaptation to ER stress. Compared to the ZnA group, mice fed with the ZnD diet showed a higher level of apoptosis with elevated expression of ATF4 and CHOP proteins. In contrast, mice fed with the ZnS diet had significantly suppressed apoptosis, suggesting zinc supplementation may be beneficial for individuals with a high risk of ER stress. In conclusion, based upon these experiments using the Zip14 KO mouse model and dietary zinc manipulation, both adequate zinc intake and functional ZIP14 are essential for adapting to ER stress by regulating the expression of proteins involved in the adaptation and apoptosis pathway of the UPR.Support or Funding InformationSupported by grant DK94244 from the National Institutes of Health.
Platelets Direct Leukocytes to their Sites of Extravasation
Authors: Zuchtriegel Gabriele , Uhl Bernd , Puhr‐Westerheide Daniel , Pörnbacher Michaela , Lauber Kirsten , Krombach Fritz , Reichel Christoph A. 
Published: November 2023

BackgroundLeukocyte recruitment from the microvasculature to the site of injury or infection is a key event in the inflammatory response. Whereas the principles of this highly complex process have been elucidated in the past decades, it remained poorly understood how these immune cells can ‘find’ their site of extravasation.ObjectiveThe objective of this study was to identify the exit points of myeloid leukocytes in the inflamed microvasculature and to characterize the mechanisms underlying the recruitment of these immune cells to these sites.Materials and methodsInteractions of platelets, neutrophils, inflammatory monocytes, and endothelial cells were analyzed by multi‐color in vivo microscopy in the cremaster muscle of male CX3CR‐1GFP/+ mice (exhibiting fluorescence‐labeled monocytes) upon stimulation with CCL2. Expression profiles of adhesion and signaling molecules in the microvasculature were assessed ex vivo by confocal microscopy in cremasteric tissue whole mounts. Different in vitro assays were used to further characterize the underlying mechanisms.ResultsUpon onset of inflammation, circulating platelets immediately adhered at distinct sites in venular microvessels enabling these cellular blood components to capture neutrophils and, in turn, inflammatory monocytes via CD40‐CD40L‐dependent interactions. In this cellular crosstalk, ligation of leukocyte PSGL‐1 by P‐selectin initiates conformational changes in surface‐expressed leukocyte integrins via ERK1/2 MAPK which subsequently promote the successive extravasation of neutrophils and inflammatory monocytes to the perivascular tissue. Conversely, blockade of this cellular partnership resulted in misguided, inefficient leukocyte responses.ConclusionHere, we report a previously unrecognized role of platelets as pathfinders navigating neutrophils and inflammatory monocytes to their exit points in the inflamed microvasculature. This platelet‐directed guidance enhances the efficacy of the leukocyte transmigration process and is essential for effective leukocytes responses.Support or Funding InformationSupported by the CRC914 (DFG)
Genetic Control of Hypertrophic Chondrocyte to Osteoblast Differentiation in Development and Skeletal Disorders
Authors: Cheah Kathryn , Au Tiffany , Wynn Sarah , Tan Tiong , Yip Raymond , Chan Danny 
Published: November 2023

Maintenance of bone throughout life requires continuous renewal of osteoblasts (Ob). Osteoblasts, originating from the perichondrium, accompany vascular invasion and lay down endochondral bone to replace cartilage. Using a genetic recombination lineage tracing approach in mice, we showed recently that hypertrophic chondrocytes (HCs), rather than being terminally differentiated cells fated to undergo apoptosis, can become osteogenic cells in fetal and postnatal endochondral bones and persist into adulthood. Moreover, the chondrocyte‐to‐osteoblast transition also occurs in bone repair. However, how the transition of HCs to osteoblasts is controlled molecularly, and the contribution of dysfunction in this process to skeletal dysplasia is not known. Heterozygous human SOX9 mutations cause the skeletal malformation syndrome campomelic dysplasia (CD). Complete inactivation of the Sox9 gene in mice results in failure of cartilage formation, presumably because of failure to express SOX9 target genes such as extracellular matrix genes, Col2a1, Col9a1, Col11a2 and aggrecan. Because all the SOX9 mutations are heterozygous, are distributed throughout the gene and appear to cause loss of function, the CD phenotype has been attributed to haploinsufficiency of SOX9. However SOX9 proteins containing an intact HMG box and a truncated activation domain may act as dominant negatives by competition with the wild‐type for binding to target genes and interfere with interaction with partner factors via the transactivation domain. The mutant proteins may also gain new function (neomorphic). We aimed to understand the underlying mechanism whereby such mutations in SOX9 cause CD and asked whether the HC to Ob transition is compromised as part of the disease pathogenesis. To address these questions, we generated a conditional mouse model of CD by knocking‐in a mouse equivalent of the human CD SOX9 Y440X nonsense mutation (Sox9Y440X), leading to truncation of the protein in the transactivation domain. We found that heterozygous Sox9Y440X/+ mice, display the phenotypic hallmarks of human CD, such as skeletal malformation, inner ear defects, except sex reversal. We compared the phenotypes of mice heterozygous for the Sox9Y440X and for the null allele. We found that Sox9Y440X heterozygous mutants displayed a more severe skeletal phenotype especially with respect to campomelia (bowing of limbs) than in Sox9−/+ mice. Since Sox9 is known to inhibit chondrocyte hypertrophy and osteoblast differentiation, we asked whether the chondrocyte to osteoblast transition is affected in the CD mutants. Molecular phenotyping and lineage tracing experiments implicate abnormality in HH signaling in CD mutants that impacts on the HC to osteoblast transition resulting in abnormal osteogenesis that underlies the campomelia phenotype.Support or Funding InformationResearch Grants Council Hong Kong and University Grants Council of Hong Kong [AoE/M‐04/04 & T12‐708/12‐N]
Direct Transformation of Chondrocytes into Bone Cells: Outside of the Box
Authors: Feng Jerry 
Published: November 2023

It has been widely accepted that hypertrophic chondrocytes undergo apoptosis prior to endochondral bone formation during limb development and long bone growth. Furthermore, it is generally believed that chondrogenesis is a separate physiological process from osteogenesis, although both processes are closely linked. However, new studies suggest that chondrocytes directly transform into bone cells during long bone formation using a cell lineage tracing approach. To extend the current study, we initially revealed only modest numbers of apoptotic cells but high levels of anti‐apoptotic Bcl‐2 expression in hypertrophic chondrocytes of growth plates, indicating that most of hypertrophic chondrocytes do not go apoptosis. Next, we revealed dividing hypertrophic chondrocytes by BrdU staining, and high alkaline phosphatase activity (early bone marker). Furthermore, ex vivo culture of newborn cartilage on a chick chorioallantoic membrane showed that after 5 days the cells on the periphery of the explants had begun to express Col1 (bone marker) and to produce bone‐like matrices. The cartilage‐specific cell lineage tracing approach in triple mice containing Rosa 26tdTomato (tracing marker), 2.3 Col1GFP (bone cell marker), and Aggrecan CreERT2 (one‐time Tamoxifen‐induced) or Col10‐Cre (activated from E14.5 throughout adult stage) proved the direct transformation of chondrocytes into bone cells in vivo. Importantly, deletion of Bmpr1a in chondrocytes (via crossing Bmpr1a and Aggrecan CreERT2 with one‐time Tamoxifen‐induction) leads to a lack of metaphysis, delayed ossification and malformed epiphysis. As a result, these mice displayed a short status and deformed knee joint. This finding supports the novel concept that the chondrogenesis is an initial phase of endochondrogenesis (phase one to build a health cartilage template for future bone formation), in which some of these chondrocytes go apoptosis, some divide, and many of them become bone cells. In phase two, most chondrocytes directly transform into bone. Taken together, this multi‐pronged approach not only demonstrates that a majority of chondrocytes directly transform into bone cells, but also challenge the dogma that chondrogenesis is a separated process from osteogenesis during endochondral bone formation.Support or Funding Information(This study was partially supported by NIH grants DE025014 and R56DE022789 to JQF).
Translating the Trypanosome Surface
Authors: Ferguson Michael A.J. , Güther Maria Lucia S. 
Published: November 2023

This talk will cover our current understanding of the African trypanosome cell surface, and in particular the biosynthesis and roles of protein N‐glycosylation and glycosylphosphatidylinositol (GPI) membrane anchoring in this organism.The peculiarities of these post‐translational modifications, and associated nucleotide sugar metabolic pathways, provide drug discovery opportunities for trypanosomiasis.The desire to exploit these, and several other, discoveries led groups at The University of Dundee to establish a Drug Discovery Unit that both translates parasite biology through to preclinical candidates and develops drug candidates phenotypically, performing drug target deconvolution at the end of the process. Examples of both approaches will be given.The Drug Discovery Unit capabilities established for parasitic diseases are also applied to innovative targets in several other therapeutic areas, and some of these will be briefly mentioned.Support or Funding InformationWe are particularly grateful to The Wellcome Trust, which has supported our work on trypanosomatids since 1988. We also thank all of our colleagues in the Division of Biological Chemistry & Drug Discovery and the Drug Discovery Unit who's work we are drawing on in this overview. Finally, we thank Alice and C.C. Wang for the great honor of giving this award lecture.
Piecing Together New Insight Into Glycosidases: structure and imaging
Authors: Davies Gideon 
Published: November 2023

Glycosidases are key players in all aspects of glycobiology. They provide mechanistic paradigms for enzyme action, they are crucial to cellular function and they provide tractable and validated drug targets. In this lecture I will present recent work on diverse enzymes under current study in my group focusing on:

New 3‐D structures, defining the topology for new CAZy families (1), and their insights into enzyme specificity and the conformational analysis of enzyme action (reviewed in 2)
Enzyme inhibition (for example 3), including applications in disease processes
Activity‐based imaging of enzyme levels in mammalian cell systems (4)
The power of chemistry and of mechanism‐based inhibitors to probe the structure and function of eukaryotic glycosidases will be central to the talk.Support or Funding InformationGJD is supported by the BBSRC, Alzheimer's Research UK, and the ERC.
Supplementation with dietary EPA/DHA influences red blood cell fatty acid desaturase estimates and reflects tissue changes in fatty acids in systemic organs
Authors: Davidson Emily Ann , Pickens Charles Austin , Fenton Jenifer 
Published: November 2023

Delta‐5‐desaturase (D5D) and delta‐6‐desaturase (D6D) are critical in polyunsaturated fatty acid (PUFA) metabolism. D5D and D6D catalyze the conversion of linoleic acid (LA) into arachidonic acid (AA) and that of alpha‐linolenic acid (ALA) into eicosapentaenoic acid (EPA). Altered PUFA desaturation (i.e., increased D6D and decreased D5D) can exacerbate inflammatory responses. Supplementation with the long chain PUFAs (LCPUFAs) EPA and DHA can influence PUFA metabolism and decrease pro‐inflammatory responses. Furthermore, changes in D5D and D6D activity are associated with obesity, type‐2 diabetes, and dysregulated metabolism. The objective of this study was to determine how increasing dietary EPA and DHA alters the D5D and D6D enzyme activity estimates (EAEs) in the RBC (red blood cell) and systemic tissues. In this study, mice were fed control plus three diets with increasing percent of energy (%en) derived from EPA+DHA. Dietary levels reflected recommended intakes of fish/fish oil by the American Heart Association. These doses translated to 0.1%en, 0.675%en, and 1.8%en from dietary EPA+DHA. Phospholipid (PL) fatty acids (FAs) were isolated from heart, skeletal muscle, spleen, lung, adipose tissue, and RBCs. PL FAs were converted to FA methyl esters and analyzed using gas chromatography. D5D and D6D EAEs were calculated using the ratio of arachidonic/dihomo‐gamma linolenic acid (DGLA) and DGLA/linoleic acid, respectively. We observed a positive correlation between RBC D5D EAEs and tissue D5D EAEs across all tissues. RBC D6D EAEs were positively correlated with muscle and negatively correlated with adipose D6D EAEs. D5D and D6D EAEs varied with EPA+DHA supplementation. When comparing the control vs the 1.8%en EPA+DHA diets, a significant decrease in D5D EAE was observed in heart (−42.51%), lung (−54.99%), spleen (−51.46%), and adipose (−78.06%). No significant difference was observed in muscle D5D EAE. Muscle D6D EAE significantly decreased (−39.95%). In adipose tissue, D6D was significantly increased compared to control (+97.80%). No significant dietary effect on D6D EAE was observed in heart, lung, or spleen with supplementation. RBC desaturase EAEs are reflective of tissue desaturase EAEs. Interestingly, RBC desaturase EAEs remained reflective of tissue desaturase EAEs despite changes in mean D5D and D6D EAEs after EPA+DHA supplementation. The high correlation between RBC desaturase EAEs and tissue desaturase EAEs with increasing dietary EPA and DHA, indicates RBC D5D and D6D EAEs are accurate non‐invasive methods to assess tissue PUFA metabolism. Future studies should investigate the usefulness of RBC desaturases in assessing tissues desaturases in disease models such as obesity, type‐2 diabetes, and metabolic syndrome and how EPA+DHA may alter fatty acid metabolism to favor an anti‐inflammatory profile.Support or Funding InformationResearch Support: NIH R03CA142000
Mammary Gland Structure and Functional Changes in Mouse Model of Chronic Gestational Alcohol Exposure
Authors: Amos‐Kroohs Robyn M , Cheng Adrienne A , Clugston Robin D , Huang Ting‐Ni , Yen Chi‐Liang Eric , Blaner William S , Smith Susan M 
Published: November 2023

Little research has been done regarding the effects of moderate ethanol exposure (PAE) on mammary gland development and subsequent milk production during lactation. Pregnant C57/Bl6J females were exposed to 3 g/kg alcohol (EtOH) from gestational day (GD) 12.5 to 17.5 in two half doses, two hours apart using isocaloric maltodextrin (MD) as controls. Most EtOH litters did not have milkspots at lactation day two (L2) suggesting that dam lactation or pup nursing was negatively affected after PAE. Mammary glands were collected from subsequent EtOH dams on L2 and were found to weigh less than MD dams (p<0.05). Carmine staining of mammary glands revealed decreased density of ducts and tubules compared with MD mammary glands preliminarily suggesting abnormal or delayed maturation. Further investigation using weigh‐suckle‐weigh methods discovered that milk letdown during a bout of nursing was significantly decreased in EtOH compared with MD litters at L2 (p<0.05). Mammary glands, liver, and adipose tissue of dams were collected for histology, fatty acid composition and retinoic acid stores, as numerous studies document the adverse effects of alcohol on vitamin A and fatty acid metabolism. Milk was collected from these dams in order to determine composition, particularly fatty acid, protein, and lactose. H & E staining in EtOH mammary glands revealed collapsed lobules and immature ducts, as well as decreased adipose stores shown by Oil Red O staining. However, retinoic acid and fatty acid composition were unaltered between groups. Although total protein concentration did not differ in the milk, free fatty acid composition was significantly altered (p<0.05), suggesting that PAE interferes with de novo synthesis of fatty acids into milk. Further studies will characterize that pathway after PAE as well as determine the lactose content and protein profile in milk and mammary gland. Hormonal changes will also be investigated because PAE has been shown to affect prolactin and progesterone which are essential for initiation of lactation. These studies are essential for determining how lactation after PAE affects nutrition and growth in populations where it is common for the affected child to remain with the birth mother.Support or Funding InformationAA11085, AA22999, T32DK007665