bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanisms of Linear Growth Acceleration in Childhood Obesity
Authors: Serrat Maria A. , Machnicki Allison L. , Song Cassaundra A. , Evans Sarah , McCloud Darby
Published: April 2020

The obesity epidemic is alarming. Nearly one‐third of children in the Unites States are overweight or obese by the time they reach their pre‐teen years. Tall stature and accelerated bone elongation are distinctive clinical features of childhood obesity, which tend to co‐occur with painful conditions such as limb bowing, slipped epiphyses, fractures, and early onset osteoarthritis. Although linear growth rate is markedly increased, obese children paradoxically have normal circulating levels of IGF‐I, the major growth‐stimulating hormone. The causes of obesity‐induced growth acceleration remain elusive. Our lab has used a well‐established mouse model of excess dietary fat in order to examine bone elongation changes that occur with the development of juvenile obesity in young growing mice. We found, surprisingly, that brief exposure to a high‐fat diet accelerates bone elongation rate without increasing body mass or circulating IGF‐I levels. Interestingly, when we used in vivo multiphoton microscopy to measure how much systemic IGF‐I localized to growth plates in real time, we found significantly more (nearly twice as much) IGF‐I in the vasculature surrounding the growth plates of mice on a high‐fat diet relative to controls. Post‐mortem immunostaining confirmed that a high‐fat diet increased the number of activated IGF‐I receptors in the growth plate, but not total receptor number. Together, these results suggest that a high‐fat diet increases local bioavailability of IGF‐I in growth plate cartilage without altering systemic IGF‐I levels, and before changes in body mass become evident. This unique method of imaging growth factor transport in cartilage is an important advancement for addressing why linear growth is accelerated in obese children who have normal levels of systemic growth‐promoting hormones. While diets high in fat are well‐recognized for cardiovascular and metabolic complications, the role of dietary fat in bone lengthening is a novel and timely area of research. These studies may provide essential data for testing whether impeding IGF‐I actions in growth plates could be a beneficial approach for mitigating some of the deleterious skeletal consequences of childhood obesity.

Support or Funding Information

Supported by the National Institute of General Medical Sciences (1P20GM121299‐01) and National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health (1R15AR067451‐01).
The Neuroanatomy of HIV, How can Physical Activity Improve the Mental Health and Quality of Life in People Living with HIV
Authors: Rosario Martin G.
Published: April 2020

Motor‐Cognitive alterations (MCAs) are associated with HIV infection and antiretroviral therapy. These MCNAs are known to be related to the frontal lobe, cognitive and motor region involvement. MCAs create a profound negative impact on their independence causing a burden to caregivers and the health care system. MCNAs dysfunctions that impact motor speed, information processing, executive functions, attention, new learning, memory, and new information retrieval are distinct and particularly prominent traits of HIV. Furthermore, recent studies focusing on the role of HIV antiretroviral medication on MCAs revealed hypertension, depression and, peripheral neuropathy are among the top main comorbidities in Hispanic people living with HIV. All the aforementioned have a profound impact in mental health and quality of life in this individuals.

The intention of antiretroviral medication is to improve the immune system, cd4 immune cells, by keeping the virus from duplicating on its host, thus reducing viral load. Average values of CD4 cell count is the gold standard to assess the effectivity of antiretroviral medication. A recent report revealed the cd4 values as a better predictor for quality of life (FAHI) and perceived balance (ABC scale) in these individuals. The above‐mentioned study found a positive correlation between cd4 count and FAHI score and a moderate correlation with the ABC scale, pointing out the importance of cd4 values as a predictor for quality of life, mental health, and perceived balance.

Since is imperative to maintain cd4 count in normal range especially in people living with HIV, another means to improve cd4 and in turn, mental health is exercising. Evidence suggests a combination of aerobic and resistance training three times a week helped improve fitness. A report evaluating the effects of a one‐year community‐based exercise program on the immune system and fitness in individuals with HIV found significant improvement in CD4 counts. These participants did show betterment in overall strength and cardiovascular fitness. This study concluded that participation in community‐based exercise programs can help improve the immune system (increase CD4 count) in people with HIV. Thence, clinicians should encourage individuals with HIV to participate in regular exercise and acquaint them with community/recreational programs.

There is more than one path to improve mental health in people living with HIV. Taking their antiretroviral medication might keep the immune system healthy, nevertheless, alterations in mental health is still an issue. Exercise by itself has been demonstrated to boost the immune system and reduce symptoms of depression, an illness that affects most of these individuals. However, a combination of normal range of cd4 count and regular exercise gives birth to a more powerful tool to aid mental health and quality of life in people living with HIV.
Next‐gen mRNA‐enhanced Cell Therapy
Authors: Cooke John P. , Mojiri Anahita , Holgate Rhonda , Walther Brandon , Li Hongye , Stubbs Colleen , Liang Yi , Callaway Celetta , Chanda Palas , Damase Tulsi , Kettlun-Leyton Claudia , Kiss Dan , Sukhovershin Roman
Published: April 2020

A new therapeutic field is emerging as obstacles are overcome to the clinical applications of mRNA drugs. The immunogenicity of mRNA has been reduced by the use of modified nucleosides and ultra‐purification. The stability and translatability of mRNA is increased by attention to optimizing codon use, the translational ramp, the 3′ and 5′UTRs, and by adding nuclease‐resistant secondary structure. The delivery of mRNA depends upon the application, but advances in targeted nanoparticle delivery vehicles, electro‐ or mechanoporation, microneedles and scaffolds have increased the delivery of therapeutic mRNA to the desired tissue. Because mRNA is non‐integrating, it is safer for human use than DNA‐based gene therapies.

Cell therapies, including stem cell therapies for regenerative medicine, may be enhanced by mRNA‐based strategies. For example, in immunodeficient mice bearing a human B cell lymphoma, chimeric antigen receptor T (CART) cell therapy against the tumor was improved by treating the CART cells with human telomerase mRNA (hTERT mRNA). Treatment with hTERT mRNA increased telomere length of CART cells; reduced senescence of the cells with expansion; increased therapeutic cell product; and increased the anti‐tumor effect in vivo. Similarly, the ability of mesenchymal stem cells (MSCs) to induce angiogenesis in ischemic tissue was enhanced by increasing MSC telomerase activity and telomere length.

Induced pluripotent stem cells (iPSCs) can be generated using mRNA encoding the Yamanaka factors, avoiding the viral integration of DNA encoding these factors. The lack of integration and its potential off‐target effects may be beneficial for iPSC‐derived cells for regenerative applications. Furthermore, mRNA encoding lineage‐determination factors can facilitate directed differentiation of these iPSCs to the therapeutic cells of choice. Alternatively, mRNA encoding the differentiation factors of choice can be administered directly to the tissue in scaffolds or nanocarriers to enhance endogenous cellular regenerative processes.

Because mRNA constructs encoding any protein of interest can be generated rapidly in a cGMP fashion, and because many effective delivery vehicles are also now cGMP capable, mRNA therapeutics is a fast, flexible, and disruptive technology that has great promise in the field of regenerative medicine and cell therapy.
Moonlighting Proteins Where Changing Shape Promotes Changing Function
Authors: Jeffery Constance
Published: April 2020

Several hundred proteins have been found to have multiple, unrelated functions. These moonlighting proteins can switch between functions through many different methods. Changes in quaternary structure and changes in conformation of a subunit are often involved. Some proteins can switch between functions when binding of a ligand causes a relatively small change in the protein conformation. For example, in some moonlighting enzymes that are also transcription factors, ligand binding can turn on the transcription factor function by causing a change in a protein’s DNA binding affinity. Other moonlighting enzymes undergo a large conformational change to uncover a previously buried functional site. Some proteins go through complete refolding of a domain or the entire protein subunit in order to perform a second function. For some proteins, called morpheeins, refolding of a protein subunit leads to an alternative quaternary structure that has a second function. Examples will be described where different subunit conformations and quaternary structures result in different protein functions.

Support or Funding Information

The author thanks the University of Illinois Center for Cancer Research for funding in support of research in the Jeffery lab.
Identification and Characterization of a Novel CREB‐H‐induced Hepatokine Implicating in Lipid Metabolism
Authors: Chan Chi Ping , Chan Pearl , Lui Wing Yu , Cheng Yun , Jin Dong-Yan
Published: April 2020

CREB‐H, a crucial transcription factor highly expressed in liver and small intestine, is critically involved in transactivation of lipid metabolism genes. CREB‐H is induced transcriptionally by fasting and has been implicated in triglyceride clearance. Hypertriglyceridemia observed in patients carrying loss‐of‐function CREB‐H mutations and in CREB‐H‐null mice is a proof of CREB‐H importance in lipid homeostasis. To decode the CREB‐H enigma in lipid homeostasis, we set off to discover and characterize new CREB‐H targets. Here, we identified a novel CREB‐H‐induced secretory protein, named Faci2, which might represent a novel hepatokine implicating in lipid metabolism and various metabolic disorders. Significant induction of Faci2 by active CREB‐HΔTC was observed in both animals and cultured cells. Additionally, endogenous hepatic expression of Faci2 in mice was highly induced by fasting in which CREB‐H is crucially required. Strikingly, forced hepatic expression of Faci2 by adeno‐associated virus in mice altered their lipid homeostasis. Animal weight gain and serum triglyceride level were significantly reduced whereas serum non‐esterified fatty acid level was elevated. Besides, Faci2 overexpression in cells or exogenous supplementation of purified Faci2 protein to cells boosted intracellular triglyceride level which is suggestive of extracellular signaling function of Faci2 in lipid homeostasis. Altogether, we have discovered a novel hepatokine induced by CREB‐H and shown that Faci2 plays an important role in lipid homeostasis. Our work sheds light on the biological significance of a novel CREB‐H‐induced hepatokine in lipid homeostasis. The new knowledge gained will instruct future development of therapeutics for various metabolic diseases such as non‐alcoholic fatty liver disease and dyslipidemias.
RNA Binding Protein ZFP36L1 Regulates Alcoholic Steatohepatitis in Mice
Authors: Patial Sonika , Saini Yogesh , Bathula Chandra
Published: April 2020

Zinc finger protein 36 like 1 (ZFP36L1) regulates mRNA levels by binding to AU‐rich elements (ARE’s) on the 3′untranslated regions (3′UTR) of specific mRNAs and enhancing their turnover. While the biochemical function of ZFP36L1 is somewhat understood, its physiological and pathological functions remain unknown. Here, we sought to investigate the roles of ZFP36L1 in liver physiology and pathology by generating liver‐specific deletion of ZFP36L1 (Zfp36l1LKO) using Cre‐loxP approach and subjecting them to alcoholic steatohepatitis. Liver‐specific loss of ZFP36L1 did not result in any aberrant phenotype in mice. However, Zfp36l1LKO mice were significantly protected from developing alcohol‐induced hepatic steatosis in Lieber‐DeCarli liquid diet‐induced model of alcoholic steatohepatitis. Serum levels of ALT did not significantly increase in Zfp36l1LKO mice upon alcohol consumption while serum levels of ALT were significantly upregulated in wild type (WT) alcohol‐treated mice. Transcriptomic analysis showed less than 170 differentially expressed transcripts in alcohol‐treated Zfp36l1LKO mice compared to greater than 500 differentially expressed transcripts in alcohol‐treated WT mice. Mechanistically, the levels of fibroblast growth factor 21 (Fgf21) mRNA were significantly increased and lipoprotein lipase (Lpl) mRNA were significantly reduced in the livers of alcohol‐treated Zfp36l1LKO mice compared to alcohol‐treated WT group. We further found evidence that Fgf21 mRNA is a direct target of ZFP36L1. FGF21 is a metabolic regulator of glucose and lipid metabolism and has been previously found to be significantly induced upon alcohol consumption and protect against alcohol‐induced liver injury. In summary, our results demonstrate that FGF21 is post‐transcriptionally regulated by ZFP36L1 in alcoholic liver injury. Modulation of levels of ZFP36L1 may be beneficial in the prevention or treatment of human alcoholic liver disease.

Support or Funding Information

Start Up Funds, LSUSVM
The complete evidence that Starling’s law responsible for many errors and misconceptions on fluid therapy in shock is wrong: The correct replacement is the hydrodynamic phenomenon of the porous orifice (G) tube
Authors: Ghanem Ahmed Nasr , Ghanem Khaled Ahmed
Published: April 2020

Introduction and objective

To report the hydrodynamic of a porous orifice (G) tube as replacement for the wrong Starling’s law.

Material and methods

Hydrodynamics of the G tube, based on capillary ultra‐structure, were studied. The effect of changing G tube orifice diameter, proximal pressure and distal pressure on the side pressure and chamber (C) pressure were evaluated. The physiological proof that the capillary works as G tube not Poiseuille’s tube is provided.

Results

Hydrodynamics of the G tube showed that proximal, akin to arterial, pressure induces a negative side pressure gradient on the G tube wall, which is negative causing suction maximum near the inlet and turn positive near the exit causing filtration. This created the rapid, autonomous magnetic field like fluid circulation phenomenon between G and C. The physiological evidence on the hind limb of sheep proves that the capillary works as G tube.

Conclusion

Hydrodynamic of the G tube challenges the role attributed to arterial pressure as a filtration force in Starling’s law. A literature review shows that oncotic pressure does not work and the law has failed to explain the capillary–ISF transfer. A concept based on the new hydrodynamic phenomenon of the G tube is proposed to replace Starling’s law. A rapid autonomous dynamic magnetic field‐like G–C circulation occurs. Factors which initiate, regulate and affect the G–C circulation, its physiological proof and relevance to clinical importance are given.’ A physiological evidence on capillary working as G tube not Poiseuille’s tube is provided.
Antihyperlipidemic, Antiperoxidative and Hypoglycemic Effects of Saponins from Solanum anguivi Lam. Fruits in Alloxan‐induced Diabetic Rats
Authors: Molehin Olorunfemi Raphael , Elekofehinti Olusola Olalekan , Oyeyemi Ajibade Oluwagbenga
Published: April 2020

Solanum anguivi Lam. fruit is commonly used in folklore medicine for the management of various diseases including diabetes in Nigeria. The present study evaluates the antihyperlipidemic, antiperoxidative, and hypoglycemic activities of saponins from Solanum anguivi fruits in alloxan‐induced diabetes rats. Diabetic rats were treated with saponin (20 – 100 mg/kg) for 21 days. Results indicated that administration of saponins significantly reduced the elevated levels of glucose, decreased total cholesterol (TC), total triglycerides (TG), low density lipoprotein (LDL) and increased high density lipoprotein (HDL) in the serum towards normalcy when compared to the diabetic control (P< 0.05). In addition, saponins exhibited strong inhibition of lipid peroxidation and increased the levels of antioxidant enzymes (superoxide dismutase and catalase) in the serum, liver and pancreas when compared to the diabetic control (P< 0.05). Our results suggest that saponins from S. anguivi fruit can enhance the hypoglycemic, hypolipidemic and antioxidant properties in alloxan‐induced diabetic rats, and may have the potential to be used in the prevention or in the management of diabetes.

Support or Funding Information

This research received no specific grant from any funding agency in the public, commercial, or not‐for‐profit sectors
Understanding the Interplay between Human Epidermal Growth Factor Receptor 2 and Neuraminidase 1 on the Regulation of Fatty Acid Binding Protein 5 in Breast Cancer Cells
Authors: McCullough Ian , Thulasiraman Padmamalini
Published: April 2020

Human epidermal growth factor receptor 2 (HER2), a member of the epidermal growth factor receptor (EGFR) family, accounts for 15–20% of breast cancer cases. HER2 is a glycosylated protein with sialic acid groups attached on the surface of the protein. Sialylated proteins can be regulated by enzymes called Neuraminidases 1 (Neu1) that catalyze the removal of sialic acid residues from glycoproteins. One of the oncogenes activated by the downstream signaling effector of the HER2 pathway is a protein called fatty acid binding protein 5 (FABP5). Elevated expression of FABP5 is correlated with poor prognosis in several carcinomas and overexpression of FABP5 prevents retinoic acid‐mediated growth suppression of mammary carcinoma cells. The objective of this study is to examine whether reducing Neu1 activity or its expression decreases HER2 activation and subsequently the downregulation of FABP5 in HER2 positive breast cancer cell line, MDA‐MB‐453. Using sialic acid assay, we quantitated the levels of sialic acid in MDA‐MB‐453 cells treated with oseltamivir phosphate, an inhibitor of Neu1 activity. Oseltamivir phosphate reduced the concentration of sialic acid in a dose‐dependent manner. Through western blot analysis, we demonstrated that suppressing the activity of Neu1 with ostelamivir phosphate in MDA‐MB‐453 cells reduced heregulin‐mediated induction of the active phosphorylated HER2 and its downstream target, FABP5. Furthermore, silencing Neu1 using siRNA reduced the expression of FABP5 protein expression in MDA‐MB‐453. Taken together, this data demonstrated that inhibition of Neu1 prevented heregulin‐induced HER2 activation, and in turn, regulated the expression of FABP5 in MDA‐MB‐453 cell line. We propose that these studies will contribute to the understanding of how Neu1 and HER2 communicate to modulate the expression of FABP5, Thus, Neu1 can be used as clinical target to improve the efficacy or sensitivity of retinoic acid in HER2+ breast cancer patients.

Support or Funding Information

Funding was obtained through the Summer Undergraduate Research Fellowship, Office of Undergraduate Research (I.M) and the Pat Capps Covey College of Allied Health Professions Start Up Fund (P.T.) from the University of South Alabama.
Transcriptional Dynamics Underpinning Muscle Senescence in Manduca sexta
Authors: Grosso Avery Del , Wone Beate , Wone Bernard W.M.
Published: April 2020

Muscle aging is a complex dynamic process that adversely affects whole‐animal metabolism and physiology. The molecular regulation of aging muscle that impacts muscle function, performance, and metabolism remains largely unknown because such studies in model organisms are prohibitively time‐ and resource‐intensive. The hawk moth, Manduca sexta, offers a unique opportunity to identify the genes that coordinate the muscle aging process. With a complete lifespan of about ten days and being similar to vertebrate muscle systems, this non‐vertebrate animal model is ideal to conduct a molecular dissection of the regulatory genes underpinning the senescence process in muscles. Here, we characterize the genome‐wide transcriptional changes by profiling gene expression from a high‐resolution time course sampling of muscle tissue from middle age to advanced age moths. Following RNA‐Sequencing of the time course tissues, we not only report differentially expressed genes across the time and day intervals, but also construct gene regulatory networks to identify candidate genes that direct the aging process. This approach will allow us to uncover novel interactions and generate new hypotheses as to the fundamental processes surrounding muscle aging. We will discuss the genes coordinating muscle senescence which include, but are not limited to, the down‐regulation of ribosome biogenesis, upregulation of Z‐band‐associated‐proteins, and down‐regulation of nicotinic acetylcholine receptors. Our results provide an unprecedented view into the complex molecular regulatory events orchestrating muscle senescence.

Support or Funding Information

South Dakota Board of Regents Competitive Research Grant #A20‐0013‐001; Nolop Institute of Medical Biology Summer Research Scholarship
Buddleja saligna Willd (Loganiaceae) Inhibits Angiotensin‐Converting Enzyme Activity in Oxidative Cardiopathy with Concomitant Modulation of Nucleotide Hydrolyzing Enzymatic Activities and Dysregulated Lipid Metabolic Pathways
Authors: Erukainure Ochuko Lucky , Matsabisa Motlalepula
Published: April 2020

Buddleja saligna Willd (Loganiaceae), mostly indigenous to South Africa is traditionally used in the treatment cardio‐dysfunctional related ailments amongst other diseases. The cardio‐protective effect of B. saligna was investigated in ferric‐induced oxidative cardiopathy. Hearts harvested from healthy male SD rats were incubated with 0.1 mM FeSO4 to induce oxidative damage and co‐incubated with B. saligna extract. Reaction mixtures without the extract served as negative control, while tissues without the extract or standard antioxidant (gallic acid) and pro‐oxidant served as the normal control. The tissues were analyzed for levels of glutathione, malondialdehyde, and nitric oxide as well as cholinergic, angiotensin‐converting enzyme (ACE), lipase, and purinergic enzymes activities, lipid profiles, fatty acid metabolic pathways and metabolites. Induction of oxidative damage significantly (p<0.05) depleted the levels of GSH, SOD, catalase, and ENTPDase activities, while concomitantly elevating the levels of MDA, NO, ACE, acetylcholinesterase, lipase and ATPase activities. These levels and activities were significantly reversed on treatment with B. saligna. Treatment with B. saligna also led to depletion of cardiac cholesterol and LDL‐c levels, while elevating triglyceride and HDL‐c level. It also depleted oxidative‐induced lipid metabolites with concomitant generation of thirteen other metabolites. B. saligna also inactivated oxidative‐induced pathways for beta oxidation of very long chain fatty acids, glycerolipid metabolism, and fatty acid elongation in mitochondria. These results suggest that B. saligna protects against ferric‐induced oxidative cardiopathy by mitigating oxidative stress, while concomitantly inhibiting ACE, acetylcholinesterase and lipase activities, and modulating lipid spectrum and dysregulated metabolic pathways.

Support or Funding Information

This work was supported by research funding from the National Research Foundation; and the Department of Science and Innovation (DSI) through the IKS‐Based Technology Innovations, Pretoria, South Africa
Prohibitin‐1 plays a multifaceted role in mediating luteinizing hormone‐induced steroidogenesis in Leydig cells.
Authors: Bassi Geetika , Mishra Suresh
Published: April 2020

Leydig cells (LCs) present in the interstitium between seminiferous tubules in the testis are responsible for the biosynthesis of testosterone from cholesterol in response to luteinizing hormone (LH) from the pituitary. The principal pathways of testosterone biosynthesis, the identities of the main steroidogenic enzymes, and genetic disorders of most of these enzymes have been elucidated. However, many important questions related to LH signaling and cholesterol transport remain unknown. For example, the mechanisms of StAR‐mediated cholesterol transport from the outer mitochondrial membrane to cytochrome P450 side chain cleavage (P450scc or Cyp11a1) enzyme in the inner mitochondrial membrane, which is a critical step in steroidogenesis, remain elusive. It is conceivable that we are missing some important players involved in this process.

Prohibitin‐1 (PHB1) is a pleiotropic protein with cell compartment‐specific functions, including the phosphorylation‐dependent membrane signaling and mitochondrial chaperone, which appears to require heterodimerization with its homologous protein prohibitin‐2 (PHB2) in the inner mitochondrial membrane. Previously, we have reported transgenic mouse models expressing PHB1 (PHB‐Tg) or Y114F‐PHB1 (mPHB‐Tg) from the fatty acid binding protein‐4 (Fabp4) gene promoter. During their phenotypic characterization, unexpectedly, we found that male mPHB‐Tg mice, but not PHB‐Tg mice, have high testosterone levels. Subsequent analysis revealed that it was due to leaky overexpression of m/PHB1 in LCs. This prompted us to investigate whether LH regulates PHB1 in LCs. A dose and time‐dependent effect of human chorionic gonadotropin, hCG (pituitary analog of LH) was found on PHB1 expression levels in LCs. To define the cell compartment‐specific role of PHB1 in LCs, we investigated the functional status of LH signaling in testes/LCs and ultrastructure of LCs from transgenic mice. A difference in phospho‐ERK levels was found between PHB‐Tg and mPHB‐Tg, which was higher in mPHB1 expressing cells. A similar effect was found in PHB1 manipulated MA‐10 cells (a model LC line). A parallel change in ultrastructural features of LCs (mitochondrial structure and lipid droplets) was found in PHB and mPHB overexpressing cells. Moreover, co‐immunoprecipitation experiments showed that PHB1 and PHB2 interact with P450scc and/or StAR. Analysis of PHBs protein sequences revealed the presence of multiple CRAC and/or CARC motifs (cholesterol recognition motifs) in both proteins. In aggregate, this finding suggests that PHB1 is a LH regulated protein in LCs and plays a multifaceted role in LH‐induced steroidogenesis, including ERK activation and potentially in the functional coupling of StAR and P450scc across mitochondrial membrane for steroidogenesis. The scope of our findings is broad because the basics of cholesterol transport across mitochondrial membranes are similar in different steroidogenic tissues.
Enhancing Abiotic Stress Response via a Kalanchoe fedtschenkoi NF‐Y Transcription Factor in C3 Plants
Authors: Malwattage Naleeka Randani Mohotti , Garcia Travis M. , Cushman John C. , Wone Bernard W. M.
Published: April 2020

Global crop production is expected to decrease because of increasing abiotic stressors including extremes in temperature, water, light intensity, nutrients, and radiation due to climate change and anthropogenic activities. Increased abiotic stressors will alter the metabolism in C3 plants and thus negatively affect their growth and productivity. Developing C3 crop varieties with improved abiotic stress tolerances emerges as the most sustainable solution towards ensuring global food security under the predicted climate change scenario. Crassulacean Acid Metabolism (CAM) plants are considered well‐adapted to drought, heat, increased light intensities, higher UV irradiation, and are far more water‐use efficient compared to C3 photosynthesis plants. The use of abiotic stress‐responsive transcription factors (TFs) from CAM plants is one feasible approach to improve crop production under adverse abiotic stress conditions. We have identified a NF‐YB TF from the heat‐tolerant obligate CAM plant Kalanchoe fedtschenkoi as a possible regulator of abiotic stresses. This NF‐Y is a ubiquitous transcription factor that is expressed as one of three possible isoforms NF‐YA, NF‐YB, or NF‐YC. Their isoforms interact to form a heterotrimeric complex with each subunit playing key roles in the abiotic stress responses including drought, heat, freezing, and salinity. We are functionally characterizing this KfNF‐YB via overexpression in Arabidopsis thaliana to determine its role in abiotic stress responses. Preliminary results following in vitro salinity stress assay of T2 transgenic lines after 12 days in MS media with 200 mM NaCl indicate increased root growth, whereas the wild type had retarded root growth. In addition, transgenic lines had higher biomass dry weight compared to wild type after 12 days. T2 lines also have increased rosette size in two‐week old transgenic A. thaliana compared to wild type. We will discuss the implications of the preliminary results as a potential strategy to enhance multiple abiotic stress tolerance responses in C3 plants.

Support or Funding Information

This work is funded by South Dakota Board of Regents Grant #A18‐0015‐001 to BWM Wone and supported in part by U. S. Department of Energy, Office of Science, Genomic Science Program under award #DE‐SC0008834 to JC Cushman.
WNT Receptor Requirements for Dishevelled Phosphorylation
Authors: Hollis Katie , Zhong Alex , Stevens Payton , Diegel Cassandra , Michalski Megan , Williams Bart
Published: April 2020

The Dishevelled (DVL) protein is a key component of WNT signaling that relays signals from receptors to downstream effectors. It has been shown that following WNT ligand binding to Frizzled (FZD) receptors, DVL is recruited to the membrane and is phosphorylated. Downstream signals of WNT require the presence of DVL. Since FZD receptors are the known receptor for WNT ligands, it has been assumed, but not shown that Wnt‐stimulated DVL phosphorylation is dependent on a FZD receptor. Since there are 19 WNTs, 10 FZDs, 3 DVLs and co‐receptors, such as LRP5/6 and ROR1/2, that play a role in Wnt signaling, it is suspected that the specific combination that forms the signaling complex determines the downstream signaling output. Most WNTs have been shown to activate canonical, β‐catenin dependent signaling, whereas WNT5a can stimulate multiple non‐canonical effector pathways such as planar cell polarity and calcium signaling. We hypothesize that the specific receptors, whether it be ROR1/2 or a particular FZD, that bind to WNT5a determine the non‐canonical pathway that is activated. In order to look further downstream, our primary objective is to determine which receptors are required in response to WNT5a to activate DVL phosphorylation.

By using cellular models missing key proteins in the WNT signaling complex, we can determine their individual functions and redundancies. To study WNT‐FZD‐DVL interactions, we are utilizing cell lines which lack all ten FZDs (FZDless), ROR1/2 (Rorless), or DVL1/2/3 (DVLless) and assessing relative expression and phosphorylation of DVL. DVL expression is decreased in RORless cells and ROR1 and ROR2 expression are decreased in DVLless cells. LGK974 Porcupine inhibitor treatment to inhibit endogenous WNT secretion also reduces DVL expression in wildtype cells. In comparison, overexpression of the FZD2 receptor, results in increased ROR2 expression. FZDless cells show no phosphorylation of DVL under endogenous WNT stimulation or in the presence of WNT conditioned media (CM). In contrast, RORless cells show DVL phosphorylation under endogenous WNT expression, but not with LGK974 and subsequent WNT5a CM treatment.

In conclusion, expression and phosphorylation of DVL are dependent on the expression of specific WNT receptors. WNT‐induced DVL phosphorylation is dependent on the presence of FZD receptors but expression of ROR receptors is not necessary. However, these requirements are dependent on the particular WNT ligand in question. WNT5a not only requires FZD receptors to stimulate DVL phosphorylation, but also requires ROR receptors. Overall, these findings demonstrate the intricacies of WNT signaling and lends itself to further investigation of these receptor requirements.

Support or Funding Information

Van Andel Institute Graduate School Fellowship
Expression and Crystallization of Adenosine Deaminase Acting on tRNA
Authors: Hurdle Carolyn M. , Macbeth Mark R.
Published: April 2020

Adenosine Deaminase tRNA Specific 1 (ADAT1) is an enzyme in the adenosine deaminase acting on RNA (ADAR) family that causes site‐specific adenosine mutation in eukaryotic tRNA. tRNA deamination by ADAT1 changes the adenosine nucleotide to an inosine, impacting the control of specific genetic programs. These enzymes do not have double stranded RNA binding motifs like that of the ADARs but instead share the catalytic domain of the ADAR. While structures for several ADAR enzymes have been determined, there are no structures for ADAT1. This research seeks to determine the structure of the ADAT1 enzyme from C. albicans. The enzyme contains conserved residues that are proposed to bind Zn2+and the inositol hexakisphosphate co‐factor, yet it has truncations that are in non‐conserved regions when compared to ADAT1 genes from other organisms. The Candida gene has been subcloned and will be expressed in S. cerevisiae. Through crystallization and X‐ray diffraction, a structure will be determined and the mechanism of substrate recognition and catalysis will be evaluated.

Support or Funding Information

Holcomb Awards Committee Grant (MRM, 2019)
Investigating the Intestine‐Specific Role of Small Heterodimer Partner
Authors: Nguyen James , Riessen Ryan , Rodriguez-Otero Jannette , Anakk Sayeepriyadarshini
Published: April 2020

Bile Acid (BA) is an essential physiological detergent synthesized in the liver and secreted into the intestine to help digest and absorb dietary lipids and nutrients. After aiding in digestion, BAs are reabsorbed and recycled back to the liver in a process called enterohepatic recirculation. Nuclear receptor called Small Heterodimer Partner (SHP) plays a fundamental role in coordinating this process. Although extensively studied in the liver, the role for SHP has not been elucidated in the intestine. Therefore, we generated and characterized the intestinal‐specific Shp knockout (IShpKO) mice. We challenged the control Floxed Shp (f/f Shp) and IShpKO with 1% Cholic Acid (CA) diet for 5 days and collected the liver and the intestine in fed and 6 hour fasted conditions. The gross phenotype (i.e. body weight change, liver‐to‐body weight ratio, intestinal length) was not altered with the loss of Shp but showed alterations when challenged with CA diet. Notably, the BA levels were increased in both the serum and intestine while triglyceride levels were increased in the serum under the absence of Shp on 1% CA diet. Despite changes in BA levels, the transcript levels of transporters and BA synthetic genes in the liver maintained their suppression upon CA feeding. This result suggests that loss of intestinal Shp does not affect liver Shp functions. However, we found that Shp‐mediated regulation of BA homeostasis was different in fed versus 6 hour fasted states. In contrast, the mRNA transcript levels in the intestine revealed that the loss of Shp misregulated the expression of BA regulators and transporters. Furthermore, region‐specific expression analysis revealed that many of the transporters and essential BA regulators including Shp are expressed in the ileum. Also, serum triglyceride levels were higher in the IShpKO group with and without excess CA diet after olive oil gavage, suggesting either (i) increased expression of fatty acid transporters or (ii) leaky gut secondary to excess BAs in IShpKO mice. To test the pathological consequence of Shp deletion in the intestine, we challenged mice with 2% Dextran sulfate Sodium (DSS) to induce colitis and found that IShpKO mice were more susceptible to intestinal damage. Taken together, we showed that Shp is a major regulator of intestinal barrier and nutrient absorption.

Support or Funding Information

National Institutes of Health (NIH) Research Grant Program (R01)
Kolaviron offered a novel cardioprotection against ischemic/reperfusion injury by modulation of Akt/protein kinase B (PKB)/p38MAPK/Caspase 3/poly‐ADP‐ribose polymerase signaling pathway
Authors: Oyagbemi Ademola Adetokunbo , Bester Dirk , Esterhuyse Johan , Farombi Ebenezer Olatunde
Published: April 2020

Free radical generation and oxidative stress have been implicated in the pathogenesis and pathophysiology of ischemic/reperfusion injury. Kolaviron is a bioflavonoid with arrays of biological and pharmacological activities. The study was designed to investigate the modulatory role of Kolaviron on ischemic/reperfusion injury in experimental animal models. Twenty male Wistar albino rats were randomly divided into two groups of ten rats per group: Group 1 received corn oil as a vehicle (Control) and rats in Group 2 were pre‐treated with Kolaviron at 200 mg/kg for 4 weeks. After 4 weeks of Kolaviron administration, hearts were excised and mounted on the working heart perfusion system. Western blot analysis for protein expressions was carried out on frozen heart samples. Results revealed significant (p < 0.05) reduction in the activity of cardiac catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx)with concomitant reduction in oxygen radical absorbance capacity (ORAC) in ischemic rat heart of Control compared to group pre‐treated with Kolaviron. Similarly, intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) contents were significantly elevated in control compared to Kolaviron pre‐treated rats. Western blot showed that pre‐treatment with Kolaviron significantly increased total Akt/protein kinase B (PKB), phosphorylated Akt/PKB at serine 473 with concomitant significant reduction in the expressions of p38 mitogen‐activated protein kinase (p38MAPK), Caspase 3, and cleaved poly adenosine diphosphate ribose polymerase (PARP). Taken together, Kolaviron offered significant cardioprotection via free radical scavenging activity and upregulation of pro‐survival signaling pathway.
Hypothalamus mediates cardioinhibitory pathway from the paraventricular nucleus of the thalamus
Authors: Puigbonet Maria E. , Li Zhaohui , Ciriello John
Published: April 2020

The paraventricular nucleus of the thalamus (PVT) is known to function as a site of integration of brainstem, limbic and cortical afferent information involved in affective behaviors, and visceral and homeostatic regulation. This study investigated the role of the hypothalamus in mediating the arterial pressure (AP) and heart rate (HR) changes elicited by activation of PVT neurons. In the first series of experiments, cardiovascular responsive sites were identified in PVT using L‐glutamate (Glu; 10 nl, 0.25 M) microinjections in chloralose‐anesthetized Wistar rats. Glu injections in the anterior PVT elicited decreases in mean AP (MAP, −20 ± 3 mmHg) and HR (−15 ± 5 bpm). In the second series, iontophoretic injections of the anterograde tract tracer PHA‐L (2.5%) were made at these depressor sites in the anterior PVT in Wistar rats. Within the hypothalamus, PHA‐L labelled fibers and presumptive terminals were predominantly found bilaterally in and around the anterior, dorsolateral and the ventromedial parvocellular components of the paraventricular nucleus of the hypothalamus (PVH). A few scattered PHA‐L labelled fibers were also observed within the posterior magnocellular component of PVH, the supraoptic nucleus, the lateral and dorsomedial hypothalamic areas, and the area of the tuber cinereum. In the final series, bilateral microinjection (100 nl) of either the synaptic blocker CoCl2, the non‐specific Glu antagonist kynurenic acid or the selective NMDA receptor antagonists 2‐amino‐5‐phosphonovalerate were made into the PVH in chloralose‐anesthetized Wistar rats. Injections of these compounds did not significantly alter the resting level of AP or HR. However, all injected compounds attenuated the MAP responses (grouped data; −15 ± 5 mmHg; p<0.01), and completely blocked the HR responses (grouped data, −3 ± 5 bpm; p<0.01) to PVT neuronal activation (control responses; MAP, −25 ± 3 mmHg; HR, −19 ± 7). These data suggest that PVT functions to alter cardiac sympathoinhibitory responses associated with arousal, stress, and affective behaviors through a glutamatergic pathway relaying in PVH.

Support or Funding Information

Supported in part by the Heart and Stroke Foundation of Ontario
Differential regulation of cardiomyocyte cohesion by signaling pathways involve ERK1/2 or Plakoglobin
Authors: Shoykhet Maria , Trenz Sebastian , Kempf Ellen , Schinner Camilla , Yeruva Sunil , Waschke Jens
Published: April 2020

Arrhythmogenic cardiomyopathy (AC) is a heart disease caused by mutations in genes encoding for desmosomal proteins such as desmoglein 2 (Dsg2) and plakoglobin (Pg) and partially paralleled with skin defects. However, therapy is symptomatic to limit arrhythmia since the mechanisms by which desmosomal components control cardiomyocyte adhesion and function are largely unknown. We have previously shown that adrenergic signaling and PKC enhance cardiomyocyte adhesion, the further of which is dependent on phosphorylation of Pg at S665. Here, we define a set of signaling pathways differentially regulating cardiomyocyte adhesion under basal as well as hyper‐adhesive, i.e., Ca2+‐ independent conditions, both of which are known to be important for epidermal integrity. In cardiomyocyte cell and cardiac slice cultures, adrenergic signaling, activation of PKC and inhibition of p38MAPK enhanced cardiomyocyte adhesion, which we refer to as positive adhesiotropy, and induced hyper‐adhesion. Positive adhesiotropy was paralleled by activation of and dependent on ERK1/2, whereas Pg phosphorylation and Dsg2 recruitment to cell junctions were induced by adrenergic signaling only. In contrast, inhibition of ERK signaling did not affect hyper‐adhesion. Finally, in heart slices from mice deficient for Pg, which displayed a strong AC phenotype, PKC activation and p38MAPK inhibition but not adrenergic signaling enhanced cardiomyocyte adhesion. Taken together, these results demonstrate that cardiomyocyte adhesion is tightly regulated by signaling mechanisms, which are in part off‐set in Pg‐dependent AC.

Support or Funding Information

DFG grant to Jens Waschke with grant number WA2474/11‐1
Anatomy for All: Accommodations for a Variety of Situations
Authors: Muchlinski Magdalena N. , Nelsen Sylvia M. , Buckley Chrys , Deane Andrew S.
Published: April 2020

Medical institutions of learning should be commended on their efforts to diversify matriculating student populations. As a result of increased university inclusion, healthcare educators are often called upon to modify their educational strategies to accommodate our increasingly diverse student body. Although a deficit in any sensory system can put a student at a disadvantage in the gross anatomy lab, visual deficits are by far the most debilitating. Gross anatomy is foundational to all aspects of medicine and is inherently biased towards visual learning. Students with neurotypical sensory systems often rely on vision to not only learn a structure’s location, but also rely on visual recall of atlas images to navigate through vision‐biased anatomy exams (i.e., students are typically not allowed to touch identified structures). Normal sighted students have difficulty identifying a cranial nerve or artery, a task made that much more difficult for one who may be legally blind. Here the authors present case studies of how to accommodate students with two types of visual impairments, bilateral coloboma and albinism. We interviewed and/or accommodated students that were legally blind, defined as a visual acuity (central vision) of 20/200 or worse in the best seeing eye or a visual field (peripheral vision) that is limited to only 20 degrees. Various strategies were used to enhance both the didactic and laboratory learning experiences, but this presentation focuses on exploring the ways we can help visually‐impaired students navigate cadaveric specimens since these learning tools best approximate future patients. As the students and their evaluators navigated their individual curricula, protocols were developed to maintain testing parity and fairness to best serve future students. We provided visually‐impaired students with dedicated assistants (tutors or faculty guides) with prior gross anatomy training to facilitate studying, dissection, and/or exams. These assistants served as an interface between the student and the dissection group, as well as between the student and the cadaver. “Reasonable accommodations” were also put into place, such as: palpation of specimens, oral descriptors of anatomical boundaries, and image‐based exams (which allowed for a picture/feature to be enlarged). The most helpful tool was palpation, which allowed learners to recall the “visual” map (proprioceptive/tactile map) of the body they had created during the learning process by tracing the course of structures with their hands. With the help of the visually‐impaired students, we hope our case studies serve as a model for the future education and evaluation of students with visual impairments.
miRNA‐Mediated Suppression of a Cardioprotective Cardiokine as a Novel Mechanism Exacerbating Post‐MI Remodeling by Sleep Breathing Disorders
Authors: Du Yunhui , Wei Yongxiang , Christopher Theodore , Lopez Bernard , Ma Xinliang , Wang Yajing
Published: April 2020

Background

Obstructive sleep apnea (OSA), a sleep breathing disorder in which chronic intermittent hypoxia (CIH) is the primary pathology, is associated with multiple cardiovascular diseases. However, whether and how CIH may affect cardiac remodeling following myocardial infarction (MI) remains unknown.

Methods and Results

Adult male mice were subjected to MI (4 weeks) with and without CIH (4 or 8 weeks). CIH prior to MI (CIH+MI) had no significant effect upon post‐MI remodeling. However, double CIH exposure (CIH+MI+CIH) or CIH only during the MI period (MI+CIH) significantly exacerbated pathologic remodeling and reduced survival rate. Mechanistically, CIH activated TGF‐b/Smad signaling and enhanced cardiac epithelial to mesenchymal transition, markedly increasing post‐MI cardiac fibrosis. Transcriptome analysis revealed that, among 15 genes significantly downregulated (MI+CIH versus MI), Ctrp9 (a novel cardioprotective cardiokine) was one of the most significantly inhibited genes. Rt‐PCR/Western analysis confirmed that cardiomyocyte Ctrp9 expression was significantly reduced in MI+CIH mice. RNA‐seq, Rt‐PCR, and dual‐luciferase reporter assays identified that miR‐214‐3p is a novel Ctrp9 targeting miRNA. Its upregulation is responsible for Ctrp9 gene suppression in MI+CIH. Finally, AAV9‐mediated cardiac‐specific Ctrp9 overexpression or rCTRP9 administration inhibited TGF‐b/Smad and Wnt/β‐catenin pathways, attenuated interstitial fibrosis, improved cardiac function, and enhanced survival rate in MI+CIH animals.

Conclusions

This study provides the first evidence that MI+CIH upregulates miR‐214‐3p, suppresses cardiac CTRP9 expression, and exacerbates cardiac remodeling, suggesting that CTRP9 may be a novel therapeutic target against pathologic remodeling in MI patients with OSA.