bluuebunny/crossref_metadata_2025 huggingface dataset:
Long‐Term Intake of Capsiate Increases Fat Accumulation according to Reduced‐Energy Expenditure, which Is Occurred by Increased‐Immobility in Diet‐Induced Obese Mice but not in Trained.
Authors: Hwang Deunsol , Kim Jisu , Seo Jongbeom , Lim Kiwon
Published: April 2020

Purpose

Having a similar weight‐loss effect which is occurred by the sympathetic nervous stimulation of capsaicin, capsiate (CAP) began to spotlight because of its much less pungency than capsaicin’s. However, previous studies have tended to focus on short‐term (to 2 from 4 weeks) effect of CAP with normal diet. Therefore, the purpose of this study was to identify the effects of long‐term CAP intake and high‐fat diet (HFD) on energy expenditure and fat accumulation. And we also investigated whether there was a synergistic effect on fat accumulation when exercised together.

Methods

The male 8‐week‐old ICR mice were divided into 4 groups. Sed0 (sedentary; non‐trained), Sed10 (sedentary and 10 mg/kg of CAP), Tr0 (moderate intensity‐trained) and Tr10 (moderate intensity‐trained and 10 mg/kg of CAP). All mice freely accessed to water and HFD.

Treadmill training was conducted with 5times a week for 8 weeks. The exercise intensity was increased from 20 min at 13 m/min to 60 min at 16 m/min while maintaining the 8° slope. The Tr groups were administrated each supplement 30 minutes before training. Tail‐suspension test was performed by suspending a mouse from horizontal bar. Mouse was suspended by its tail for 6min, and the immobility time was measured during the last 5min, with the first minute ignored to allow for habituation.

Results

Long‐term intake of CAP did not significantly change the body weight gain in the both sedentary and trained group. However, the total food intake was significantly lower in the Sed10 than in the Sed0 and reversely greater in the Tr10 than in the Tr0. Interestingly, the total abdominal fat was significantly higher in the Sed10 than in the Sed0 and the training showed a tendency to reverse this result but there was no significant difference within the Tr group. From the resting metabolic rate results, the total energy expenditure was slightly lower in the Sed10 than in the Sed0 but there was no significant difference within both Sed and Tr group. However, there was significant difference between the Sed10 and the Tr10 but not between the Sed0 and the Tr0. From the tail suspension test results, the immobility time was significantly longer in the Sed10 than in the Sed0 and there was no significant difference within the trained group. But the BDNF protein level in the hippocampus was no different.

Conclusion

In summary, these results show that long‐term intake of CAP with HFD increased fat accumulation according to reduced‐energy expenditure, which seemed to be occurred by immobility. But the moderate intensity‐exercise reversed these results. Therefore, if CAP is used to increase energy expenditure over long periods of time, we suggest that exercise and/or dietary control should be properly combined. Furthermore, these findings provide a slight insight that long‐term intake of CAP with HFD could be assessed by the neuropathological approach.
Description and outcomes of a baccalaureate level clinically oriented gross anatomy course
Authors: Thompson Andrew R. , Giffin Bruce F.
Published: April 2020

While many universities offer some type of anatomy course at the baccalaureate level, training in clinically oriented human anatomy with a dissection component has traditionally been restricted to advanced degrees in the medical, dental, and veterinary fields. The University of Cincinnati College of Medicine (UCCOM) offers a Bachelor of Science degree in Medical Sciences to train students with a strong interest in pursuing a career in healthcare. In 2018, a human gross anatomy course was added to the curriculum that includes both lecture and lab (dissections) components and focuses on clinically relevant anatomy and medical imaging. The purpose of this study is to 1) describe the development of the course and 2) to determine if undergraduate students are able to perform at a comparable level to medical students in the content area of clinical anatomy. The latter goal was achieved by blueprinting examinations related to the limbs for the undergraduate and medical school courses at UCCOM using Bloom’s taxonomy and then comparing performance between the two groups of students. A total of 70 and 39 lecture‐examination questions for undergraduate and medical students were analyzed, respectively. Practical examinations were also considered for the limbs region.

Results demonstrate that undergraduate students perform almost identically to medical students on lecture examination questions that target the first three levels of Bloom’s Taxonomy (remember, understand, and apply). Application level questions are, however, more challenging for undergraduate students as they scored ten percent lower, on average, compared to medical students. On practical examinations, undergraduate students averaged seven percent lower than medical students. Higher‐order practical examination questions are more challenging for undergraduate students as they averaged nearly 15% lower than medical students. The average discrimination index of higher‐order practical exam questions was also larger in the undergraduate course at 0.55 compared to 0.27 with medical students. Overall, these results suggest that undergraduate students have the capacity to perform at a comparative level to medical students on advanced, clinically‐relevant gross anatomy material. However, some undergraduate students may be less equipped to handle higher‐order assessment questions.
TRPV4 mechanosensing regulates normal human lung fibroblast migration
Authors: Rahaman Suneha G. , Goswami Rishov
Published: April 2020

Fibroblast migration is recognized as a critical process in wound healing and fibrosis. Although the influence of both a biomechanical signal (e.g., matrix stiffness) and a biochemical signal (e.g., transforming growth factor beta1; TGFbeta1), are essential for fibroblast migration, the molecular mechanisms by which migratory signals are transduced are poorly understood. Here, we report that TRPV4, an ion channel in the transient receptor potential vanilloid family, and which is a mechanosensor, is required for both TGFbeta1‐ and matrix stiffness‐induced migratory response (chemotaxis, durotaxis, scratch wound closure, and adhesion) of normal human lung fibroblasts. Furthermore, TRPV4 antagonism by a selective small molecule inhibitor abrogates calcium influx, stiffness‐induced stress fiber formation, and both TGFbeta1 and matrix stiffness‐induced focal adhesion kinase (FAK) activation. Moreover, we show that TRPV4 activity is required for stiffness‐induced force generation in migrating fibroblasts as determined by Traction Force Microscopy analysis. Taken together, these results suggest that TRPV4 and FAK interact to drive fibroblast migration by potentiating TGFbeta1 signaling in a manner dependent on matrix stiffness. Successful manipulations of the TRPV4 activity may be a novel therapeutic approach to the treatment of fibrotic diseases.

Support or Funding Information

This work was supported by NIH (1R01EB024556‐01) and NSF (CMMI‐1662776) grants.
Ramipril Blunt Glycerol‐induced Acute Renal Failure in Rats Through its Anti‐apoptosis, Anti‐inflammatory, Anti‐oxidant, and Renin‐inhibiting Properties
Authors: Adedapo Adeolu Alex , Ehizogie Osaretin Ruth , Falayi Olufunke Olubunmi , Oyagbemi Ademola Adetokunbo , Ogunpolu Blessing Seun , Omobowale Temidayo Olutayo , Oguntibeju Oluwafemi Omoniyi , Yakubu Momoh Audu
Published: April 2020

Acute Kidney Injury (AKI) is a sudden episode of kidney failure or kidney damage that happens within a few hours or a few days and causes a buildup of waste products in the blood making it hard for the kidney to keep the right balance of fluid in the body. It affects other organs such as the heart, brain and lungs (Schrier et al., 2004). Renal tubular damage is a pathological characteristic of AKI. Currently, animal models of glycerol‐induced AKI are widely used [Mousleh et al 2018]. Glycerol injection into the muscle causes the release of myoglobin and other muscle contents into the circulation, ultimately resulting in AKI. Studies have demonstrated that the pathogenesis of glycerol‐induced AKI involves myoglobin toxicity [Gburek et al 2003; Reeder and Wilson 2005], reactive oxygen species (ROS) [Wu et al 2017], inflammation [
Al Asmari et al 2017], apoptosis [Wang et al 2011] and redox‐active iron [Wu et al 2017].

In this study ramipril and pioglitazone (reference drug) were evaluated for their potential therapy in glycerol‐induced AKI in rats. Twenty animals divided into four groups of five animals per group were used. Group I served as control while group II received glycerol on day 8 only. Groups III and IV were administered with pioglitazone and ramipril for 7 days respectively and on day 8 received glycerol. On day 9 blood samples were collected for serum biochemical analysis of markers of oxidative stress, enzymatic and non‐enzymatic antioxidants, creatinine and blood urea nitrogen. Animals were sacrificed thereafter; and kidney tissues were harvested for histopathology and immunohistochemistry. Expression of caspase 3, renin receptor, NK‐KB, and KIM‐1 were carried out.

Results from this study show that ramipril and pioglitazone significantly inhibited markers of oxidative stress while also significantly increased the levels of enzymatic and non‐enzymatic anti‐oxidant markers. These drugs caused decreased levels of creatinine and BUN. Histopathologically, there were massive infiltration of leucocytes and congestion of the kidney in toxicant group, but the ramipril treated group showed a milder condition. In immunohistochemistry, the two drugs significantly inhibited the expressions of the four proteins, which were highly expressed in the toxicant group.

This study thus showed that ramipril and pioglitazone have nephroprotective effect and thus has ability to blunt acute kidney injury through their anti‐inflammatory, anti‐apoptosis, anti‐renin and anti‐oxidant properties.

Support or Funding Information

This study was supported with a grant (TETFUND/DESS/NRF/UI IBADAN/STI/VOL. 1/B2.20.11) received from the National Research Foundation of the Tertiary Education Trust Fund (TETFUND), Abuja, Nigeria.
Peptide‐stabilized nanomaterials for drug delivery and cancer therapy
Authors: DRAGULSKA SYLWIA ANNA , POURSHARIFI MINA , CHENG YING , Martignetti JOHN , MIESZAWSKA ANETA JOANNA
Published: April 2020

Peptides are increasingly applied in medical field, including applications in cancer therapies, cardiovascular diseases, but also in metabolic disorders and in the development of antibiotics. There are over a hundred of small‐peptide therapeutics undergoing clinical trials. The big advantage of small peptides is their fast and easy synthesis, modification and low cost. In addition, they are biodegradable, which greatly facilitates their biological and pharmaceutical applications. Importantly, short peptides that include phenylalanine residue were found to have self‐assembling properties that could be used to stabilize nanostructures. The goal of this study is to develop peptide‐stabilized nanoparticle–based system for delivery of anticancer agents at high dosages. This work explores self‐assembling tri‐ and hexapeptides as a coating material for polymeric and oil‐based nanoparticles and delivery of cytotoxic platinum‐based drug as well as antiangiogenic combretastatine A4 (CA4). The nanoparticles have spherical morphology and the size, confirmed with transmission electron microscope, is ~ 100 nm. This size range is suitable for clinical applications, as small‐sized nanoparticles extravasate through leaky tumor vasculature into the tumor’s interstitium: a phenomenon known as enhanced permeability and retention (EPR) effect or passive targeting. The components of the nanoparticles are biocompatible and biodegradable and amino acids have an FDA Generally Recognized As Safe (GRAS) status, which reduces future barriers clinical applications of the proposed nanoparticles.
Nogo‐B deficiency inhibits high‐fat diet‐induced obesity by reducing NF‐κB‐mediated inflammation
Authors: Wang Xiaolin , Zhao Dan , Duan Yajun , Yang Xiaoxiao , Chen Yuanli , Han Jihong
Published: April 2020

Obesity has become a public health issue that impairs life quality and increases health‐care costs. It also increases risk of health complications, such as insulin resistance, type 2 diabetes and cardiovascular diseases. Numerous studies have shown that obesity is accompanied by chronic inflammation which aggravates obesity and obesity‐associated complications. Nogo‐B, an endoplasmic reticulum‐residential protein, regulates ER morphology. It can be secreted into blood and exerts its biological effects in various tissues. Herein we report that human serum Nogo‐B level is positively correlated to body‐mass index, serum triglyceride and total cholesterol levels. In wild type mice, Nogo‐B expression was regulated by different metabolic conditions, indicating Nogo‐B may play an important role in the development of obesity and other metabolic diseases. In Nogo‐B knockout mice, Nogo‐B deficiency protected mice against high‐fat diet (HFD)‐induced obesity. Mechanistically, Nogo‐B deficiency decreased lipid accumulation in the liver by activating AKT and AMPKα pathways to enhance insulin sensitivity and lipid oxidation. In adipose tissue, lack of Nogo‐B expression facilitated the browning of adipocytes, indicating enhanced energy expenditure. Moreover, Nogo‐B deficiency inhibited ectopic lipid accumulation and increased mitochondria biogenesis in skeletal muscle by upregulating PGC‐1α, PPARα and phosphorylated AMPKα. The results of protein array assay indicated that Nogo‐B deficiency significantly decreased levels of serum proinflammatory cytokines induced by HFD. It also reduced infiltration of macrophages into multiple tissues, such as liver, white adipose tissue, brown adipose tissue and islets. The percentages of anti‐inflammatory M2 macrophages in WAT and BAT were notably upregulated in Nogo‐B KO mice, which was associated with reduced proinflammation M1 macrophages. Furthermore, Nogo‐B deficiency enhanced NF‐κB p65 degradation via lysosome pathway and reduced NF‐κB p65 translocation via TLR4 pathway. Taken together, our study demonstrates that Nogo‐B deficiency protects mice against HFD‐induced obesity, which is associated with inhibition of inflammatory cytokine expression, macrophages infiltration and M1 macrophage transformation by reducing NF‐κB p65 expression and translocation. Our study also suggests that Nogo‐B functions as a metabolic and inflammatory regulator and it may be a potential drug target for obesity treatment.
Strong Antimicrobial Activity of Hydroxamic Acids and Newly Synthesized Derivatives
Authors: Antunes Daniel Ignacio D. , Aslanian Robert G. , Aqani Omar , Desai Harshal , Bendaoud Meriem
Published: April 2020

Antibiotic resistant pathogenic bacteria are a growing worldwide health concern according to the Centers for Disease Control and Prevention. These bacteria are responsible for most of the infectious diseases and healthcare‐associated infections in hospitals (HAIs). The need for new therapeutic approaches using novel antimicrobial compounds is becoming vital as the number of infections caused by antibiotic resistant strains of bacteria such as Staphylococcus aureus and Staphylococcus epidermis has drastically increased. The focus of this study is to test newly designed and synthesized therapeutic agents for antimicrobial properties. Several hydroxamic acids and analogs synthesized by the Chemistry Department at New Jersey City University were tested for antibacterial activity against eight ATCC strains of human and plant pathogenic microorganisms. The antimicrobial activity of each compound was evaluated using the disk‐diffusion assay and the liquid broth assay. All compounds displayed a various spectrum of antibacterial activity. Compounds with the strongest antimicrobial effect were selected for further characterization to determine the minimal inhibitory concentration using serial dilution and absorbance reading. A subset of compounds with antimicrobial effects against plant pathogens were further tested for cytotoxicity and the ability to prevent fruit and vegetable bacterial infections. Future work will focus on using a cell‐culture‐based assay to test the remaining compounds for animal cell cytotoxicity.

Support or Funding Information

This research was done under the support of the U.S. Education Department Title III Part F HSI Grant # P031C160155, the NSF IUSE (Improving Undergraduate STEM Education) Award #

1611843, and the New Jersey City University Separately Budgeted Research Fund.
Preeclamptic Fetal Programming Alters Neuroinflammatory and Cardiovascular Consequences of Endotoxemia in Sex Specific Manners
Authors: Abuiessa Salwa Aburageh , Wedn Abdalla M. , El-Gowilly Sahar M. , Helmy Mai M. , El-Mas Mahmoud M.
Published: April 2020

Preeclampsia (PE)‐induced fetal programming predisposes offspring to health hazards in adult life. Here, we tested the hypothesis that preeclamptic fetal programming elicits sexually dimorphic inflammatory and cardiovascular complications to endotoxemia in adult rat offspring. Preeclampsia was induced by oral administration of of L‐NAME (50 mg/kg/day for 7 consecutive days) starting from day 14 of conception. Cardiovascular studies were performed in conscious adult male and female offspring pre‐instrumented with femoral indwelling catheters. Compared with non‐PE male counterparts, i.v. administration of lipopolysaccharide (LPS, 5 mg/kg) to PE male offspring caused significantly greater (i) falls in blood pressure, (ii) rises in heart rate and left ventricular contractility (dP/dtmax), and (iii) decreases in time‐ and frequency‐domain indices of heart rate variability. By contrast, the hypotensive and tachycardic actions of LPS in female offspring were independent of the preeclamptic state and no clear changes in heart rate variability or left ventricular function were noted. Measurement of arterial baroreflex activity by the vasoactive method revealed no sex specificity in baroreflex dysfunction induced by LPS. Immunohistochemical studies showed increased protein expression of toll‐like receptor 4 in the heart as well as in brainstem neuronal pools of the nucleus of the solitary tract and rostralventrolateral medulla in endotoxic PE male, but not female, offspring. Enhanced myocardial, but not neuronal, expression of monocyte chemoattractant protein‐1 was also demonstrated in LPS‐treated male offspring. Together, preeclamptic fetal programming aggravates endotoxic manifestations of hypotension and autonomic dysfunction in male offspring via exacerbating myocardial and neuromedullary inflammatory pathways.

Support or Funding Information

Supported by the Science and Technology Development Fund, Egypt (STDF Grants No. 14895)
Molecular Characterization of the HIRA Histone Chaperone Complex from Chaetomium thermophilum
Authors: Szurgot Mary , Marmorstein Ronen
Published: April 2020

The HIRA histone chaperone complex is an essential epigenetic regulator which deposits the histone variant H3.3 onto DNA to condense it into chromatin and to regulate the epigenetic landscape of the cell. Because the HIRA complex and H3.3 deposition is associated with areas of active transcription in the genome, HIRA dysregulation is associated with disordered development, aging, and maintenance of terminally differentiated cell types. The goal of our studies is to understand the molecular basis of H3.3‐specific histone deposition by the HIRA complex. Toward this goal, we recombinantly express orthologs of the four HIRA complex components‐ HIRA, UBN1, CABIN1, and ASF1a‐ from the thermophilic fungus Chaetomium thermophilum for biochemical and structural characterization. We show efficient recombinant expression of each subunit, determine complex stoichiometry using analytical ultracentrifugation, and begin structural analysis using a combination of X‐ray crystallography and cryo‐electron microscopy of the subunits alone, in complex, and with histones.

Support or Funding Information

Structural Biology and Molecular Biophysics Training Program, NIH 5‐T32‐GM‐008275‐29; Epigenetics of Aging and Age‐Associated Diseases P01, NIH 5P01AG031862‐12
The Effect of Glutathione on Itraconazole‐Associated Hepatocyte Toxicity in an In Vitro Canine Model
Authors: Kirk Natalie M. , Vieson Miranda D. , Selting Kimberly A. , Reinhart Jennifer M.
Published: April 2020

Background

Itraconazole (ITZ) is used to treat many fungal infections in dogs. However, therapy is associated with dose‐dependent increases in liver enzymes in up to 42% of dogs. Glutathione (GSH) precursors are commonly used to treat ITZ‐associated hepatotoxicity, although no studies have investigated the efficacy of this practice.

Objective

To identify the effect of GSH on cell survival in an in vitro model of ITZ‐associated hepatotoxicity using canine primary hepatocytes.

Methods

Using a sandwich culture technique, pooled canine primary hepatocytes were incubated for 24 hours with 10‐fold dilutions of GSH (0 to 500 μM). Following GSH pre‐incubation, the cells were exposed to 5‐fold dilutions of ITZ (0 to 50 μM). Cell viability was determined using the neutral red assay after 4 and 24 hours of ITZ exposure (n=3). The effect of ITZ concentration, time, and GSH concentration on cytotoxicity was assessed using multivariate linear regression. Hepatocyte phenotype was assessed by measurement of albumin production using an enzyme‐linked immunosorbent assay (ELISA) kit for canine albumin and morphological assessment via phase contrast microscopy.

Results

Canine hepatocyte cytotoxicity significantly increased with ITZ concentration (p<0.001) and time (p=0.004). Whereas, hepatocyte cytotoxicity significantly decreased with GSH treatment (p<0.001). Maintenance of hepatocyte phenotype was confirmed by continued production of albumin and maintenance of cell morphology over time.

Conclusions

The in vitro model demonstrates dose‐ and time‐dependent ITZ cytotoxicity. Pre‐treating with GSH provides a protective effect against cell death in this model. These results suggest that GSH precursors may have a role in the management or prevention ITZ‐associated hepatotoxicity in dogs. Clinical trials are needed to evaluate their utility for this adverse drug reaction.
A High Fat Diet in Pregnancy Modifies Mouse Maternal Behaviour
Authors: Moazzam Showall , Noorjahan Noshin , Jarmasz Jessica S. , Jin Yan , Siddiqui Tabrez J. , Cattini Peter A.
Published: April 2020

Background

About a third of pregnant women of age 20–39 are obese, which carries significant risks for the mother and fetus, and adversely impacts pregnancy outcome. Specifically, women with obesity are at increased risk for peripartum depression. Maternal behaviour in mice is influenced by changes in hormone signaling in pregnancy, which is associated with effects on adult neurogenesis in the brain. Thus, we used mouse as a model system to gain further insight into the possible relationship between overeating/obesity and brain physiology and maternal behaviour.

Objective

To assess the ability of a high‐fat diet (HFD) versus a regular chow diet (CD), starting up to 10 weeks pre‐pregnancy, to modify glucose clearance before and during pregnancy and affect maternal behaviour in the CD1 mouse.

Approach

Two groups of 3–4 week‐old female CD1 mice were fed a HFD (fat=60 kcal%; carbohydrate=20 kcal%; protein=20 kcal%) or CD (fat=14 kcal%; carbohydrate=60 kcal%; protein=26 kcal%) and maintained on their respective diets throughout the study and weighed periodically. After at least 4 weeks of feeding on their diets, mice were allowed to breed. Glucose tolerance was tested using 2 g/kg of i.p. glucose at gestational day (GD) ‐1) after fasting (16 hours‐overnight) as well as during pregnancy at GD16.5. An even number of pregnant and non‐pregnant females were selected for each diet for maternal behaviour testing. Tests include an assessment of nest building at GD16.5–17 (use of nesting material and nest quality), and after birth pup retrieval at postpartum day (PD) 3, 4 and 5 (time of retrieval of each of the four pups within six minutes) using video capture.

Results

The HFD led to a significant increase in weight relative to mice fed a CD. HFD impaired glucose‐load clearances at GD ‐1 and 16.5 (p<0.05) compared to mice fed a CD. Mice fed on HFD performed poorly in the nest building task (p<0.01) as well as demonstrated a reduced completion rate on the pup retrieval test on PD3 (CD=8/10 vs. HFD 2/9 mice) but their retrieval response latency was improved by PD4 (CD=8/10 vs. HFD 8/9 mice) and PD5 (CD=7/10 vs. HFD 7/9 mice).

Conclusions

Initial observations suggest that a HFD for at least 4 weeks before and during pregnancy results in overweight CD1 mice with impaired glucose clearance, and a negative effect on maternal behaviour as assessed by nest‐building during pregnancy and pup retrieval postpartum; however, with regard to the latter, mice on the HFD show the ability to learn. Additional behavioural tests for locomotion, anxiety, risk avoidance and object recognition memory during or after pregnancy, as well as associated changes in hormonal signaling and adult neurogenesis are also currently under investigation.
Cannabinoid receptor‐1 expressing interneurons require postsynaptic dystroglycan for targeting during postnatal brain development
Authors: Miller Daniel S. , Wright Kevin M.
Published: April 2020

Dystroglycan is a transmembrane glycoprotein highly expressed in muscle and brain that links the extracellular matrix to the actin cytoskeleton through its two subunits, a heavily glycosylated extracellular subunit alpha dystroglycan (a‐DG), and the membrane spanning beta‐dystroglycan (b‐DG). Glycosylation of dystroglycan by at least 18 enzymes is essential for its ability to bind extracellular ligands throughout development. Mutations in genes encoding glycosyltransferases such as B4gat1 and ISPD reduce dystroglycan function and cause a spectrum of congenital muscular dystrophies characterized by muscle weakness, brain malformations, and cognitive deficits. In the brain, dystroglycan is expressed by both glia and excitatory neurons, but its specific function in neurons has remained elusive. Recently, neuronal dystroglycan was discovered to be important for the formation of presynaptic cannabinoid receptor 1 (CB1R) synapses derived from cholecystokinin (CCK) interneurons, a population of inhibitory cells in the forebrain. However, the mechanism by which dystroglycan regulates the development of CCK/CB1R+ inhibitory synapses remains unknown. In the present study, we use multiple mouse lines to determine how dystroglycan regulates CB1R+ synapse development, including mouse models of dystroglycanopathy (B4gat1, ISPD), conditional genetic deletion of dystroglycan from neurons and glia (Dag1‐cKO: Nex‐Cre, Emx‐Cre, Nestin‐Cre), and a mouse lacking the intracellular signaling domain of dystroglycan (Dag1ICD). We found that deletion of dystroglycan specifically from excitatory neurons resulted in the loss of nearly all presynaptic CB1R+ terminals within the first week after birth. Surprisingly, deletion of dystroglycan from both neurons and glia using Nestin‐Cre or Emx‐Cre resulted in abnormal targeting of CB1R+ terminals. We also find that maintenance of CB1R+ terminals in adulthood does not require full glycosylation of a‐DG or the intracellular signaling domain of b‐DG. Collectively, these results suggest that dystroglycan may be required for the proper targeting of CB1R+ synapses during postnatal brain development.

Support or Funding Information

NINDS R01 NS091027 (KMW)NINDS F31 NS108522 (DSM)ARCS Fellowship (DSM)Tartar Fellowship (DSM)
Effect of ankle joint position on triceps surae motor unit firing rates
Authors: Hali Kalter , Zero Alexander M. , Fanous Jacob , Rice Charles L.
Published: April 2020

The triceps surae is an interesting model to study the effect of muscle length changes on motor unit properties for two reasons. First, the gastrocnemii components show lower motor unit discharge rates (MUDRs) when shortened by knee joint flexion as compared to an extended knee joint, whereas all other muscles studied display either higher or similar MUDRs in a shortened compared to a lengthened position. Second, the soleus receives strong afferent feedback due to its predominantly type I muscle fiber composition indicating that muscle length changes may have a great effect on its motor unit properties. The limited previous studies have not explored how changes in ankle joint position affect the triceps surae muscles. Thus, the purpose of this study was to compare MUDRs of the bi‐articular medial gastrocnemius (MG) and mono‐articular soleus at two ankle joint positions, 30° dorsiflexion and 20° plantar flexion, during the common task of plantar flexion. Four young, healthy men (~24 years old) were seated upright in a leg dynamometer with both the hip and knee joint angles at 90°. Subjects performed two ~3s isometric plantar flexion maximal voluntary contractions (MVC) at each ankle joint position. Tungsten electrodes were then used to record MUDRs from the MG and soleus during separate steady state 3–10s isometric plantar flexion contractions at 25, 50, 75, and 100% MVC at one ankle joint position. After a series of contractions, the ankle joint angle was changed and the subjects performed another series of plantar flexion contractions at each torque level. Initial ankle joint position and the order of contractions performed were randomized prior to each testing session. Subjects visited the lab multiple times to repeat the intervention in order to sample from many motor units. The mean MVC torque was 53% lower in the shortened (20° plantar flexion; 105Nm) compared to the lengthened (30° dorsiflexion; 223Nm) position. A total of 487 motor units from the MG (n=228) and soleus (n=259) were identified. Mean MG MUDRs at 25, 50, 75 and 100% MVC were lower by 8, 0, 17 and 14%, respectively in the dorsiflexed compared to the plantar flexed position. Similarly, mean soleus MUDRs were lower by 8, 12, 25 and 25% at 25, 50, 75 and 100% MVC, respectively in the dorsiflexed compared to the plantar flexed position. These preliminary findings indicate that shortening the MG and soleus by placing the ankle joint in a plantar flexed position leads to higher MUDRs as compared to a dorsiflexed position. This may serve as a compensatory mechanism for the decreased torque producing capability of the triceps surae in a shortened (plantar flexed) position.

Support or Funding Information

Funded by NSERC.
The role of bilirubin and heme metabolism in neuronal stress signaling
Authors: Paul Bindu Diana , Vasavda Chirag , Kothari Ruchita , Malla Adarsha , Ricco Cristina , Snowman Adele , Tokhunts Robert , Sedlak Thomas W. , Snyder Solomon
Published: April 2020

Bilirubin is amongst the most frequently measured peripheral metabolites, yet its roles in vivo are not totally understood. Believed to be a marker for liver function, it is now increasingly evident that bilirubin plays vital roles in the brain. Bilirubin is synthesized by Biliverdin reductase (BVR) from biliverdin, which in turn is derived from heme. BVR exists as two isoforms, BVR‐A and BVR‐B, of which BVR‐A is enriched in the brain. In addition to its role in bilirubin generation, BVR‐A is a kinase and transcription factor, and participates in several signaling pathways. Besides, these activities, the BVR pathway plays significant roles in maintenance of redox homeostasis in cells. Cell culture studies have shown that depletion of BlvrA, the gene encoding BVRA causes elevated oxidative stress and associated cellular damage. Using BlvrA−/− mice, we show that BVRA is the major enzyme responsible for bilirubin production. The gall bladders of these mice are green due to accumulation of biliverdin and inability to produce bilirubin. We analyzed the effects of bilirubin depletion in the brain using these mice. Paucity of bilirubin leads to elevated superoxide production in the brain and altered cytoprotective response to stress stimuli. These mice are defective in several antioxidant defense pathways. BlvrA mice also display a variety of behavioral abnormalities including cognitive deficits. We further show that bilirubin is a potent and direct superoxide scavenger in vivo, which accounts for its role in maintenance of redox balance. Treatment of mice with N‐methyl D‐aspartate (NMDA), an excitotoxin, results in increased neuronal death and larger lesions in BlvrA−/− mice. NMDA receptor activation is known to elevate superoxide production via the NADPH oxidases, enzymes which are known to be inhibited by the BVR‐bilirubin pathway. Taken together, our findings uncover important roles for BVR in neuroprotective processes. Modulating the BVR/bilirubin pathway may offer therapeutic benefits in neurodegenerative diseases involving redox imbalance.

Support or Funding Information

NIH grants
MH18501(to S.H.S.)
Dysregulated hydrogen sulfide metabolism links aberrant neuronal stress responses and neurodegeneration in Huntington's disease
Authors: Paul Bindu Diana , Snyder Solomon H.
Published: April 2020

Hydrogen sulfide (H2S) is a gaseous signaling molecule that plays central roles in a myriad of physiological processes ranging from response to oxidative stress and transcriptional regulation. Hydrogen sulfide is synthesized endogenously from the semi‐essential amino acid cysteine via the reverse transsulfuration pathway. Thus disrupted cysteine metabolism may also lead to aberrant H2S signaling. One of the modes by which hydrogen sulfide signals is by a posttranslational modification designated as sulfhydration/persulfidation, which occurs on reactive cysteine residues on target proteins, where the reactive SH group is converted to an SSH group. Sulfhydration is a highly prevalent modification which modifies the structure and/or activity of target proteins. Research on H2S and persulfidation is still in its infancy. We show here that H2S is generated in response to stress stimuli such as Golgi stress and oxidative stress in neurons, which modulates sulfhydration levels to modulate signaling pathways. We further show that these cytoprotective stress responses are compromised in striatal cell culture model and the R6/2 and Q175 mouse models of Huntington’s disease (HD). We have shown previously that the biosynthetic enzyme for cysteine and H2S in neurons, cystathionine g‐lyase (CSE) is depleted in HD and mediates neurodegeneraton. HD is a neurodegenerative disease which is triggered by expansion of polyglutamine repeats in the protein huntingtin, which causes it to aggregate and elicit multi‐system toxicity. Restoring H2S balance in cells mitigates neuronal dysfunction in neurodegenerative diseases such as HD. A screen for regulators of the transsulfuration pathway has resulted in identification of compounds that modulate cysteine balance and disease progression in HD.

Support or Funding Information

United States Public Health Service (USPHS) grants
DA000266 and
MH18501 to S.H.S.
Monitoring the activity and screening for selectivity of various classes of cAMP‐Phosphodiesterases (cAMP‐PDEs) using a homogenous HTS formatted bioluminescent platform
Authors: Goueli Said , Hsiao Kevin , Mondal Subhanjan , Zegzouti Hicham
Published: April 2020

Age associated decline in cognitive functioning present a monumental problem as manifested in the appearance of neurodegenerative diseases such as dementia, Alzheimer diseases, depression, and schizophrenia. Furthermore, the FDA approval of PDE‐5 inhibitors for erectile disfunction and the utility of these inhibitors in treatment of serious diseases such as pulmonary hypertension validates these group of enzymes as significant drug targets. The need to monitor the activity of these enzymes in a homogenous, easy to perform and highly reproducible, and sensitive format will be highly desirable. Towards this goal, we have developed a bioluminescent assay that monitor their activity using very low enzyme concentrations in 384‐well formats, and easy to perform protocol. We have used this assay to monitor the activity of several cAMP‐PDES such as PDE3, PDE4, and PDE10 as examples and were able to detect their activity using nanogram of enzyme concentrations. The assay enabled us to check for selectivity of various known inhibitors that are selective for their targeted enzyme. We also generated IC50 (inhibitor concentration that inhibit enzyme activity by 50%), that are similar to those reported in the literature. This assay can be also used to profile several inhibitors against various cAMP‐PDEs and thus, it may facilitate the development of novel therapeutics towards these enzymes.

Support or Funding Information

This research was supported by Promega Corp.
“Kidney and urinary metabolic profiles of monosodium glutamate consumption in Wistar rats”
Authors: Nahok Kanokwan , Thanan Raynoo , Silsirivanit Atit , Selmi Carlo , Cha’on Ubon
Published: April 2020

While its effects on human health are still debated, monosodium glutamate (MSG) has been widely used globally for at least five decades. Since there are no reliable biomarkers of MSG consumption in human, the monitoring of harmful effects of MSG intake on human health is not feasible. We aim to investigate the kidney and urinary metabolic profiles of MSG consumption in animals. Adult male Wistar rats were assigned into 4 groups, including receiving water with 1 g% MSG added, 0.34 g% NaCl added, 2.4 g% NaHCO3 and normal drinking water. Urine chemistries were analyzed before and after 2 weeks of MSG‐treatment. Urinary metabolic profile was determined after MSG supplementation using NMR technique. Kidney tissue were also investigated for ion‐exchanger genes expression including its metabolites. The results revealed that the MSG‐ and alkaline‐treated groups had significantly higher levels of urine pH, urine sodium and bicarbonate compared to controls. This corresponds to the lower expression of ion‐exchanger genes (CAII, NBC1, and AE1) involved in bicarbonate reabsorption in kidney of MSG‐ and alkaline‐treated groups compared to controls. The kidney metabolic profile of MSG and control groups were also investigated. We found that trimethylamine had significantly higher level in MSG group, whereas the higher levels of pyridoxine found in controls. In conclusion, MSG‐treated rats are able to induce alkaline urine, reduce bicarbonate reabsorption and generate the urinary metabolic profiles similar to that of alkali supplemented animals. Moreover, the urinary and kidney metabolomics revealed that there is a connection between the uremic toxin and MSG consumption in rats.

Support or Funding Information

The Royal Golden Jubilee Ph.D. Program (RGJ‐Ph.D. Program) (PHD/0124/2558). The Invitation research fund (IN62137), Faculty of Medicine, Khon Kaen University, Thailand.
Inhibiting Cytoskeletal Remodeling Increases Tension Cost in Airway Smooth Muscle
Authors: Jensen Cole , Kafaji Mustafa , Han Young , Sieck Gary
Published: April 2020

Cytoskeletal remodeling in smooth muscle occurs with activation and involves actin polymerization. Remodeling of the cortical cytoskeleton allows tethering of contractile proteins and force transmission to the extracellular matrix. Smooth muscle contraction involves cross‐bridge cycling and ATP hydrolysis, which are both sensitive to loading. During isometric activation, the rate of ATP hydrolysis is initially high but declines with time reaching a steady‐state, while peak force is maintained. Thus, tension cost, i.e., the rate of ATP hydrolysis per unit of force, decreases over time, reflecting increased efficiency of smooth muscle activation. We hypothesize that the time‐dependent decrease in ATP hydrolysis rate and tension cost is due to cytoskeletal remodeling and an increase in internal loading on cross‐bridges. In permeabilized porcine airway smooth muscle (ASM) strips, isometric force and ATP hydrolysis rate were simultaneously measured after maximum Ca2+ activation (pCa 4.0). From each animal, two ASM strips were tested: 1) Inhibition of actin polymerization and cytoskeletal remodeling using Cytochalasin‐D (Cyto‐D; treated (1 μM for 30 min); and 2) Untreated controls. Compared to untreated controls, Cyto‐D‐induced inhibition of actin polymerization reduced both peak and steady‐state isometric force by ~40%, while peak and steady‐state ATP hydrolysis rate increased by ~30% and ~20%, respectively. As a result, at peak and steady‐state, tension cost increased by ~100% and ~60%, respectively, following Cyto‐D treatment. These results support our hypothesis that the time‐dependent decrease in ATP hydrolysis rate reflects an increase in internal load on cross‐bridges via cytoskeletal remodeling. Cyto‐D inhibition of cytoskeletal remodeling impairs contractile protein tethering and thus reduces internal loading, resulting in faster cross‐bridge cycling and increased ATP hydrolysis rate.

Support or Funding Information

Supported by NIH grant HL126451(GCS), HL150890 (GCS) and the Mayo Clinic
Developing an LED‐based model of the NMJ for the undergraduate classroom
Authors: Turin Daniel Ryan , Olson Hunter Leroy , Petzold Andrew Michael
Published: April 2020

The physiology behind the transmission of a nerve signal within the neuromuscular junction (NMJ) is a complex concept that can be used as a framework to explain many other signal transduction events across physiology. These can include neurotransmitter release, membrane depolarization, and channel activity. Traditionally, complex and static drawings have been used to teach this mechanism of action to students. While useful, these images can become complicated due to the lack of physically moving parts. A simple video could be sufficient but we wanted to create a unique and memorable moving diagram that combines a static image with moving images. After developing, building, and programming the model, we used it in two different introduction to physiology classes; one aimed at pre‐professional students and one aimed at students entering non‐patient care‐related fields in the health sciences. To determine whether the model was successful, we asked students about their understanding of the material before and after exposure to the board and their interaction with the board. While there was no significant impact on their exam scores compared to classmates who did not use the model, students were generally appreciative of the model. Students noted that the model helped them to visualize the process, allowing them to learn step by step and at their own pace, however, they also suggested that the sequence of lights is slowed down and that the model be more available prior to the exam.
Mechanisms Underlying TNFα‐Induced Hyperreactivity in Airway Smooth Muscle
Authors: Kafaji Mustafa , Jensen Cole , Han Young , Delmotte Philippe , Dogan Murat , Sieck Gary
Published: April 2020

Inflammation and pro‐inflammatory cytokines (e.g., TNFα, IL‐13) induce airway smooth muscle (ASM) hyper‐reactivity and remodeling characteristic of asthma. We hypothesized that exposure to TNFα (and IL‐13) increases isometric force generation in porcine ASM via several underlying mechanisms: 1) increasing sensitivity to ACh stimulation; 2) enhancing the cytosolic Ca2+ ([Ca2+]cyt) response to ACh; 3) increasing the Ca2+ sensitivity of force generation; 4) enhancing the Ca2+‐dependent phosphorylation of myosin regulator light chain (rMLC); 5) promoting expression of non‐muscle rMLC; 6) increasing actin and myosin heavy chain (MyHC) content (i.e., the number of contractile units); and/or 7) promoting cytoskeletal remodeling (actin polymerization). Studies were performed on intact ASM strips (~1 mm wide × ~5 mm long) dissected from porcine tracheas obtained from a local abattoir. The ASM strips were placed in PSS with and without TNFα (100 ng/ml) for 24 h. The ACh concentration dependence of force generation ASM was determined (ACh range from 10 nM to 1mM), and the EC50 (i.e., the ACh concentration that produces 50% of maximal ASM force) was determined. In control, untreated ASM, the EC50 for ACh was 2.6 μM compared to 1.3 μM following TNFα treatment. We found that across all ACh concentrations, ASM force increased after TNFα treatment with an ~50% increase in maximum ASM force. The [Ca2+]cyt response induced by the EC50 [ACh] was similar in control and TNFα treated ASM. Thus, with an increase in force and no effect on [Ca2+]cyt, there was an apparent increase in Ca2+ sensitivity of force after TNFα treatment. However, in both control and TNFα treated ASM, the extent of rMLC phosphorylation induced by ACh stimulation was not affected by TNFα treatment. Importantly, the extent of rMLC phosphorylation at the ACh EC50 was comparable between control and TNFα treatment indicating no change in Ca2+ sensitivity. The expression of non‐muscle rMLC (determined by 2D gel electrophoresis) was also unaffected by TNFα treatment. Total actin and MyHC concentrations increased by ~45% following TNFα treatment; thus, the number of contractile units contributing to force increased. This was reflected by a marked increase in the Ca2+ activation of ATP consumption (cross‐bridge cycling) of ASM following TNFα treatment. Cytoskeletal remodeling was evaluated by ACh‐induced actin polymerization (F‐/G‐actin ratio) but was found to be unaffected by TNFa treatment. Together, our results show that two primary mechanisms underlie the marked increase in ASM force generation induced by 24‐h TNFα exposure: 1) an increase in ACh sensitivity, and 2) an increase in actin and MyHC concentrations (number of contractile units).

Support or Funding Information

Supported by NIH grant HL126451 (GCS) and HL150890 (GCS)