bluuebunny/crossref_metadata_2025_split huggingface dataset:
A High Fat Diet Induces Decreased Levels of Colonic Tight Junctions and Inflammatory Cytokine Expression in Sprague Dawley Rats
Authors: Sambolin‐Escobales1 Lubriel , Nazario Madeline , Torres‐Aguiar Roberto , Cruz Myrella L , Yamamura Yasuhiro , Appleyard Caroline B , Chompre Gladys 
Published: November 2023

High fat diet consumption is associated with a variety of metabolic disorders such as diabetes, hyperlipidemia, and cardiovascular diseases among others. Also, an intake of high fat is associated with inflammation of the intestinal epithelial barrier, and characterized by increased intestinal permeability. This increased permeability is characterized by the loss of tight junctions due to decreased expression of claudin‐5 and occludin. Our preliminary data found increased colonic macroscopic damage and a trend towards increased microscopic damage in rats fed a High Fat Diet (HFD) compared with a Low Fat Diet (LFD). In addition, metagenomic analysis from HFD feces demonstrated increased bacteriodes with higher serum levels of lipopolysaccharide (LPS) in the HFD group, however it is still unclear if tight junction expression is altered.HYPOTHESISHigh fat diet will cause a lower expression of tight junction proteins, which increases membrane permeability allowing the entrance of LPS contributing to intestinal inflammation.METHODWe purified colon RNA samples from rats fed with LFD (n=14) or HFD (n=14) for 30 days. Amplification of mRNA levels of chemokine ligand (CCL2), interleukin1β (IL‐1β), tumor necrosis factor receptor alpha (TNF‐α receptor), claudin‐5 and occludin were measured to determine their total expression.RESULTSWe found a decreased expression of both claudin‐5 and occludin in the HFD rats compared with the LFD (p<0.05) suggesting damage in the epithelial membrane as expected. On the other hand, there was a trend towards lower levels of CCL2 (p=0.08), IL‐1β (p=0.06), and TNF‐α receptor (p=0.05) in the HFD compared with the LFD. In conclusion, colon is constantly exposed to bacterial components such as LPS, without triggering pro‐inflammatory immune responses suggesting an alternate molecular mechanism of evasion.CONCLUSIONSThis study helps to understand the consequences in the colon following consumption of a high fat diet.Support or Funding InformationPUCPR seed grant G12RR003050/G12MD007579, P20 GM103475‐14
Assessing Muscle Protection with Pharmacological Post‐Conditioning Agents in an Acute Ischemia Reperfusion Model
Authors: Thomas Kathryn N , Soule Charles L , Mattison Lars M , Iaizzo Paul A 
Published: November 2023

BackgroundCardiorespiratory complications remain as a primary source of morbidity in elective aortic surgeries and heart transplantations. This is in part due to induced tissue ischemia, resulting in an increased risk in reperfusion injuries. In particular, diaphragmatic dysfunction and/or atrial fibrillation produced by ischemia reperfusion (I/R) injuries contributes to clinical complications after cardiothoracic surgeries. Therefore, post‐conditioning of the diaphragm and cardiac muscles with pharmacological agents may play a critical role in conferring protection and restoring tissue function in such patients.MethodsPortions of muscle were removed from swine diaphragm (n=5) and from a human heart deemed non‐viable for transplant (n=1). The diaphragm or ventricular endocardial surface (trabeculae) were dissected into bundles, attached to force transducers, and submersed into tissue baths. Electrical stimulation was applied to the bundles, and peak forces of muscle contractions were recorded. These tissues were exposed to hypoxia followed by reoxygenation to assess resultant damage throughout a recovery period. Randomly, after the hypoxic periods, bundles were treated with given concentrations of either Omegaven fatty acid emulsions, delta‐opioid (DPDPE), and tauroursodeoxycholic acid (TUDCA).ResultsPercent changes in peak forces of the swine diaphragm and human trabeculae muscle contractions post‐conditioned with these agents and various concentrations showed no significant changes from controls (p>0.05). Non‐toxic agents with potential therapeutic benefits could be applied to various in situ animal models to provide further insights as to the dosing paradigms for full‐organ effects.ConclusionThis experimental approach with isolated muscle bundles within tissues baths has the potential to be both a time‐and cost‐effective means for screening pre‐ and post‐conditioning pharmacological agents. Further work is needed to find the drugs, dosages, and hypoxia levels necessary to determine whether the tissue baths mimic an ideal I/R model in vitro.Support or Funding InformationThis project was funded in part by IEM and Medtronic, Inc. Support for summer student research was provided by the Clinical and Translational Science Institute Advanced Research Program 2015 at the University of Minnesota.
Human Skeletal Muscle Glyoxalase‐1 Protein Expression is Attenuated with Type 2 Diabetes
Authors: Mey Jacob T , Mahmoud Abeer M , Haus Jacob M 
Published: November 2023

INTRODUCTIONIndividuals with type 2 diabetes mellitus (T2DM) present with increased levels of advanced glycation endproducts (AGEs), which have been associated with progression and complications of the disease. AGEs are known to contribute to the disruption of insulin signaling in skeletal muscle and are primarily produced in vivo by the damaging glycolytic byproduct, methylglyoxal (MG). MG is effectively detoxified by the enzyme, glyoxalase‐1 (GLO1), whose protein expression has been previously shown to be inversely related to MG‐mediated protein‐damage and AGE formation. Despite the role of skeletal muscle insulin resistance in the pathogenesis of T2DM, GLO1 protein expression has not been fully elucidated in skeletal muscle. Additionally, the metabolic effects of insulin stimulation on GLO1 protein in human skeletal muscle has not been described.PURPOSETherefore, the purpose of this study was to examine skeletal muscle GLO1 protein content in individuals with T2DM compared to lean, healthy controls (LHC). Further, we sought to examine the effects of insulin stimulation on GLO1 protein expression through in vivo and in vitro approaches that included the hyperinsulinemic‐euglycemic clamp and primary human skeletal muscle cell culture experiments, respectively.METHODSSkeletal muscle biopsies from the vastus lateralis were obtained from 7 individuals with T2DM (age: 55 ± 4 yrs, BMI: 35.6 ± 2.4 kg/m2) and 10 LHCs (age: 27 ± 1 yrs, BMI: 22.3 ± 0.8 kg/m2) during basal and insulin stimulated states of the hyperinsulinemic (40mU/m2/min)‐euglycemic (5 mM) clamp. To further investigate the effect of insulin, primary human skeletal muscle cells were incubated with 300 pM insulin (a concentration similar to that experienced during the hyperinsulinemic‐euglycemic clamp) for 0, 30, and 180 mins. GLO1 protein content in human tissue and cell culture was assessed via western blot.RESULTSIndividuals with T2DM displayed a 5.6 fold reduction (p<0.0001) in GLO1 compared to LHC at baseline. Clamp‐induced hyperinsulinemia had no significant effect on GLO1 protein expression in either group (p>0.05). In cell culture, 30 minutes of insulin stimulation increased GLO1 protein expression by 37 % (p=0.0093). Interestingly, continued insulin stimulation for 180 mins returned GLO1 protein expression to levels comparable to baseline (0 min vs 180 min, p>0.05).CONCLUSIONThese data suggest that the skeletal muscle of T2DM may be susceptible to MG‐mediated protein damage and accumulation of AGEs. Further, prolonged exposure to hyperinsulinemia may attenuate early insulin mediated increases in GLO1 expression profiles. Further study is need to elucidate the exact mechanisms of these observations.
Elevated Intramuscular Calcium Effects on Mitochondrial Biogenesis
Authors: PinaJr Dagoberto , Zhang Rui , López Jose R. , Pessah Isaac , Baar Keith 
Published: November 2023

Caffeine is known to raise intracellular calcium (Ca2+) levels in the brain; however, the effects of caffeine consumption on intramuscular Ca2+ and subsequent mitochondrial biogenesis have not been addressed in vivo.PurposeTo determine whether caffeine can increase intracellular calcium levels in skeletal muscle and stimulate mitochondrial biogenesis.MethodsMice were administered caffeine (0.2 mg/mL) through their water for 7 days. At the end of seven days of caffeine treatment, intramuscular calcium levels were determined through a modified patch clamp technique. Following determination of intramuscular calcium, muscles were excised and rapidly frozen in liquid nitrogen prior to analysis of mitochondrial protein levels by western blot. Antibodies used include p‐CAMKII Thr286 as a measure of CAMK activity, COX5, COX4, HAD, LCAD, MCAD, VLCAD, Cytochrome‐C, CD36, CPT‐1, citrate synthase, and PGC1‐α.ResultsCaffeine treatment increased intracellular Ca2+ levels (CON=113nM, CAF=156nM; p<0.05). However, the increased intramuscular Ca2+ was not sufficient to modify the levels of mitochondrial proteins (p>0.05).ConclusionCaffeine treatment increases intramuscular Ca2+ levels but is not sufficient to drive mitochondrial biogenesis. However further studies are needed to determine whether caffeine could augment the effects of endurance training on mitochondrial mass.
Generation Of A New Renal Nephrotoxicity Model By Using A Microfluidic System
Authors: Sanchez‐Romero Natalia , Arias Cristina , Martinez Laura , Torcal Pilar , Sanchez‐Zalabardo Manuel , Iñigo Pablo , Gimenez Ignacio 
Published: November 2023

AimTo generate a biomimicking cell culture system to study the toxicity caused by exposure to cisplatin and the process of reparation‐regeneration after the injury, in proximal tubule cells grown in microfluidic devices.MethodsPrimary cultures of human proximal tubule cells (hPTPC) are generated from healthy tissue isolated from nephrectomy specimens. The hPTPC are cultured on conventional cell culture containers or inside the channels in polysterene microfluidic devices. Morphological and biochemical characterization of the cultured cells is performed by using PCR, immunofluorescence (IF) and immunocytochemistry (ICC) to verify the expression of selected proximal tubule and epithelial markers.Confluent hPTPC monolayers are exposed to six cisplatin concentrations in the 0–300 uM range. Cisplatin citotoxicity is assessed by determining three parameters in two different optical reactions: the first assay combines PrestoBlue reagent, a cell viability indicator, with a gamma‐glutamyl transferase 1 (GGT1) substrate. GGT1 is a specific luminal border enzyme in hPTPC and is responsible for the bioactivation of cisplatin into a more potent toxin. In the second assay, cell number is estimated through nuclear DNAstaining with crystal violet.ResultsThe phenotyping techniques have been optimized to work with the small volumes and cell numbers present in microfluidic devices. Biochemical characterization of hPTPC through multiplex analysis of phenotypic markers shows these cells retain the most relevant PT markers when cultured in microfluidic channels.Cisplatin exhibits cytotoxicity on hPTPC when grown on multiwell plates or microfluidic channels. The EC50 was found to be 30–50 μM for the three parameters determined in our assay. Maximal effects were observed in approximately 48–72h after exposure to cisplatin. Our data suggest that hPTPC cultures do not possess autoregenerative capacity. The cytotoxicity model has been successfully adapted for its use in microfluidic devices, with preliminary data showing no change in hPTPC sensitivity to cisplatin.Conclusions
The phenotypic characterization of our hPTPC confirms typical characteristics of proximal tubule, and its preservation in cells cultured on microfluidic channels.
The effects of cisplatin are time and concentration dependent. Simultaneous reading of assays for cell viability, enzymatic activity, and cell numbers in hPTPC allow us to perform studies of renal toxicity and repair in cells grown inside microfluidic devices.
This is the first step towards a cell culture model for the study of proximal tubule physiology and physiopathology under biomimicking conditions that will include exposure to flow‐mediated shear stress.
Support or Funding InformationSpain's Ministerio de Economía, grant DPI2011‐28262/C02 and fellowship BEP‐2012‐059562 (to NS‐R)
The Effects of Fasting and Refeeding on Regulating NLRP3 Inflammasome Activation in Asthmatic Subjects
Authors: Nguyen An , Li Jessica , Kwarteng‐Siaw Miriam , Traba Javier , Han Kim , Sack Michael 
Published: November 2023

The NLRP3 inflammasome is linked to inflammatory diseases including asthma. Interestingly, we have shown that fasting (24 hours) blunts and refeeding (3 hours after a meal) activates the NLRP3 inflammasome in peripheral blood mononuclear cells (PBMCs) from normal volunteers and that the serum extracted at the fasted and refed time points can recapitulate this effect in THP‐1 macrophage cells. At the same time it has also been found that intermittent fasting reduces asthma exacerbations in a clinical study. Based on this we have begun to evaluate whether fasting and refeeding regulate the NLRP3 inflammasome in mild to moderate asthmatic subjects exposed to a 24 hour fasting and 2.5 hour refeeding protocol. Preliminary studies in the first 8 study participants have been analyzed. Interestingly, the asthma subjects (n=3) who were not treated with inhaled steroids showed a 24% increase in refeeding activation of the NLRP3 inflammasome as measured by IL‐1β release as was found in the normal volunteers. However, the asthma subjects (n=5) who were treated with inhaled corticosteroids did not show an induction of the inflammasome with refeeding (rather a 39% reproduction in IL‐1β release compared to fasting). When comparing the serum from the asthmatic subjects, the results were opposite to the normal controls where serum from fasting subjects showed increased IL‐1β release in response to inflammasome triggering compared to serum from the fed state. Interestingly, the baseline IL‐1β levels were markedly elevated in the asthmatic subjects serum compared to the normal controls. These preliminary data suggest that: (i) inhaled steroids have systemic effects and disrupt the immune modulatory effects of fasting and refeeding; (ii) the basal inflammatory milieu evident in asthma disrupts the nutrient‐deprivation effect on blunting the NLRP3 inflammasome.Support or Funding InformationCardiovascular and Pulmonary Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD USA.Biomedical Research Training Program for Individuals from Underrepresented Groups (BRTPUG), National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD USA.
Comparison of Hypoglossal Motoneuron Transgene Expression following Single vs Dual Tongue Injection of AAV9‐CBA‐GFP
Authors: Doyle Brendan M. , Turner Sara M.F. , Johnson Bobbi , Streeter Kristi A. , Falk Darin J. , Mandel Ronald J. , Byrne Barry J. , Fuller David D. 
Published: November 2023

Retrograde transport of viral vectors following intramuscular injection allows for targeted gene delivery to motoneuron pools. Gene delivery to the hypoglossal (XII) motoneurons is of potential interest in disorders involving impaired tongue muscle control such as dysphagia, dysarthria, and possibly obstructive sleep apnea. Using a murine model of Pompe disease, our group has shown that a single intramuscular injection of 1.00e11 vector genomes (vg) of recombinant adeno‐associated virus serotype 9 (AAV9) into the base of the tongue produces sustained transgene expression in a subset of XII motoneurons. Here we investigated whether distributing the virus over a broader portion of the tongue via two near‐simultaneous injections would increase XII motoneuron transduction as compared to a single injection. Four week old 129SVE mice were anesthetized and administered either a unilateral, single 20μL injection (n=2) or bilateral, 10μL injections (n=2) to the anterior base of the tongue targeting the insertion point for the genioglossus muscle. In both cases, a total of 1.00e11 vg of AAV9 encoding green fluorescent protein (GFP) with expression driven by the chicken β‐actin promotor (AAV9‐CBA‐GFP) was given. The medulla was histologically evaluated 6 weeks after tongue injection; GFP was detected using immunohistochemistry. Robust XII motoneuron GFP expression was observed in the caudal XII nucleus after either single or dual AAV9 injection; initial observations suggest no differences in XII motoneuron transduction between the two delivery methods. With both approaches, GFP expression was primarily restricted to XII motoneurons, but was also sporadically present in neurons throughout the medulla. The data confirm that tongue injection of AAV9 drives robust transgene expression in the XII motoneuron pool, and suggest that expression is similar whether using the single or dual injection approach.Support or Funding Information2R01HD052682‐06A1
Effect of SCI on Learning and Memory; Age, Gender and Species Differences?
Authors: Kempisty Rachel A , Zimmer M. Beth 
Published: November 2023

Spinal cord injury (SCI) results in damage to neurons that connect the brain to all areas of the body leading to disturbances in sensory and motor signals below the injury site. A few studies also show that neural changes occur above the site of injury and memory is affected. Preliminary data in our lab showed that the acquisition phase of learning was altered 2 weeks after injury in young male rats. This study hypothesized that older rats may not recover as quickly as young rats from SCI and therefore SCI may lead to more significant alterations in learning and memory. Older, female Sprague Dawley rats were anesthetized with ketamine and xylazine and a C2 hemisection (n=14) or a sham surgery (n=10) was performed. Rats were allowed to recover for 2 weeks before learning and memory was assessed with the Morris Water Maze. Rats completed 4 trials a day for 5 days followed by a probe trial. Results obtained were analyzed and compared to preliminary data that used young, male Long Evans rats. The results showed that SCI injured rats took longer to acquire new memories compared to sham controls, however this was only significant in young male Long Evans rats. The differences between the two groups of animals may be due to age, gender or species. Current studies are aimed at determining why SCI did not affect learning and memory in older, female Sprague Dawley rats.Support or Funding InformationThis work was funded by a Ferris Student Research Fellowship (RAK), the Dean's Student Research Grant (RAK), a Ferris Foundation Merit Award (MBZ) and a Ferris Faculty Grant (MBZ).
Teaching Muscle Recruitment using Applied Technology in High School Students
Authors: Cole Shelby N , Hayslip Rachel , Jarrett Steven , Miller Breena , Doades Shelby , Gurovich Alvaro N 
Published: November 2023

This project was designed to educate High School students on the importance of understanding muscle physiology. Forty‐seven students from 2 upper anatomy/biology classes at South Vermillion High School in Clinton, IN were exposed to the importance of muscle recruitment and how the number of motor units increases in response to an increase in weight. The primary information was presented in a PowerPoint presentation. Then, 6 Biopac MP40 were available to both classes and 4 students per system collected data. The Biopac MP40 is an interactive device used to display data using electrodes to pick‐up electrical signals released by the muscle cells (electromyography or EMG). Three electrodes were placed on each subject's dominant and then non‐dominant anterior forearm and the EMG was measured during three conditions: 1) wrist flexion without load, 2) wrist flexion with 5 Lb., and 3) wrist flexion with 10 Lb. The students were challenged to set up the Biopac MP40 system, perform the experiment, and analyze the data. Finally, during a second day of this activity, students were asked to analyze and present the collected data. The students enjoyed learning the physiological effects behind motor unit recruitment and they have ‘PhUn’ during the process.Support or Funding InformationSupported by IU AHEC 15/16 #PIU535 and APS PhUn week program
Increased muscle myofibrillar protein breakdown rates using 3‐methyl‐histidine (tau‐mHIS) stable isotopes in a Pseudomonas aeroginosa (PM) induced hyperdynamic sepsis pig model
Authors: Ten Have Gabriella A , Engelen Marielle P , Wolfe Robert R , Deutz Nicolaas E 
Published: November 2023

RationaleSepsis is characterized by severe muscle breakdown. Tau‐methyl‐histidine (mHIS) is generally considered a valuable marker of muscle myofibrillar protein breakdown. Quantitative measurement of the production of mHIS in urine is complicated due to factors like timing and correct sampling, meat‐free diet requirement, and differences in mHIS metabolism between species. Therefore, we measured whole body mHis production (WbRa) using stable isotope technology during acute sepsis in the pig. We also examined organ mHis metabolism to establish the site of mHIS production.MethodIn 13 conscious post‐absorptive pigs (±25 kg) with intravenous PM induced hyper‐dynamic sepsis and 9 healthy controls, we measured mHIS‐WbRa during a primed, constant and continuous infusion of L‐[tau‐2H3]‐mHIS stable isotope. Two hours before and between 14 and 18 hours during sepsis, we collected arterial plasma, and at 18 hours we obtained jejunum, jejunal mucosa scraping, ileum, liver, muscle and lung tissue. Enrichments of mHIS in plasma and intracellular pools were analyzed by LC‐MS/MS. WbRa was calculated with the tracer infusion rate and plasma mHIS steady state enrichment. Low mHIS enrichment in tissue in comparison to plasma enrichment defines a mHIS production site. Data are mean (SE) in nmol/kg bw/min; Fitting of plasma steady state enrichment curves, ANOVA and unpaired t‐tests were done by GraphPad Prism6.ResultsWe found increased WbRa values of mHIS 16 to 18h after sepsis induction in jejunal mucosa biopsies: 53.7(2.1) vs 37.2(1.9), p<0.0001. At t=18 h, we found low mHIS enrichments (25 (2.4)% of plasma enrichment, P<0.0001) only in muscle. Jejunum, jejunal mucosa scraping, ileum, liver, and lung tissue show higher enrichments than plasma (112(1.6)%, NS between tissues).ConclusionDuring acute severe sepsis in the pig, the increased whole body myofibrillar protein breakdown as measured in plasma during mHIS tracer infusion is fully related to muscle myofibrillar protein breakdown. We hypothesize that the use of mHIS stable isotope technology is a reliable tool to specifically measure changes in muscle myofibrillar protein breakdown in multiple species, including humans.Support or Funding InformationThis study was supported by NIH R01GM084447 and S10RR027047