bluuebunny/crossref_metadata_2025 huggingface dataset:
Transgenic mice overexpressing an endothelial‐targeted Fas‐inducing apoptosis construct exhibit pulmonary hypertension associated with marked lung arterial remodeling
Authors: Goldthorpe Heather , Parsons Sean A. , Jiang Jin-Yi , Deng Yupu , Stewart Duncan J.
Published: June 2021

Objective

Pulmonary arterial hypertension (PAH) is a lethal disease, characterized by complex vascular lesions and increased pulmonary vascular resistance. To test the hypothesis that lung EC apoptosis at the level of distal pulmonary arterioles is necessary and sufficient to cause PAH phenotype we developed a novel transgenic model.

Methods and Results

The Fas‐Induced Apoptosis (FIA) construct was expressed under the control of endothelial‐specific, Tie2 promoter in transgenic mice (i.e. EFIA mice). Two transgenic lines characterized by low and high expression levels (LE and HE, respectively) were generated. LE‐EFIA exhibited normal pulmonary hemodynamics and vascular structure at baseline; however, administration of a small molecule dimerizing agent, AP20187, resulted in lung microvascular apotosis and modest dose‐dependent increase in RVSP. Interestingly, HE‐EFIA transgenic mice showed significant elevation in baseline RVSP compared to wild‐type controls even in the absence of the AP compound (34± vs. 24±4 mm Hg, respectively; p<0.005). 40% of HE‐EFIA mice also exhibited perivascular lesions, localized to distal lung arterioles which were highly proliferative by Ki67 and EDU staining, and exhibited variable degrees of apoptosis.

Conclusion

Our data suggest that EC apoptosis is sufficient to induce PAH, which is associated with marked inflammation and remodeling of lung arterioles.
Platelet Derived Growth factor Receptor α (PDGFRα) in Liver Development
Authors: Awuah Prince , Misse Amalea , Monga Satdarshan
Published: June 2021

PDGFRα signaling is critical and indispensable during development. Global inactivation of this receptor has been shown to be embryonic lethal. The critical role of this receptor during development has been shown in certain organs including, lung and brain. Liver development is a complex and temporal process, which entails a balanced regulation of proliferation and differentiation of the bipotential stem cells (hepatoblasts) of the liver. Recently, robust PDGFRα expression was identified as early as embryonic day 11 during early liver development albeit with a gradual decrease until birth. Additional PDGF‐CC, a ligand for PDGFRα was observed during early and PDGF‐AA at late stages of hepatic development, while PDGF‐BB was expressed at all times. Using phospho‐specific antibodies to PDGFRα, temporal phosphorylation events were identified only during early hepatic development indicating downstream activation of specific pathways. PDGFRβ was also expressed during early liver development. However, double immunofluorescence studies identified hepatocyte specific hepatic nuclear factor 4 alpha (HNF4α) to colocalize with PDGFRα and not PDGFRβ. Based on ongoing proliferation, survival and differentiation of hepatoblasts and hepatocytes at early stages of hepatic development and concomitant PDGFRα signaling at the same stages, we conclude that PDGFRα may be an important mediator of these critical biological events in hepatic development. Funded by CATER fellowship (NIH T32 EB001026‐05) to PA; 1R01DK62277 and 1R01CA124414 to SPM
miR24‐2 inhibits human liver cancer growth though Smad2/Smad4‐mediated induction of P21/CIP1/WAF1
Authors: Lu Dongdong , Han Chang , Wu Tong
Published: June 2021

miR‐24‐2 has been shown as one of the most important down‐regulated miRNAs in human cancers. However, its potential implication in hepatoma has not been investigated. In this study, we showed that forced overexpression of microRNA24‐2 in human hepatoma cells (Huh7 and Hep3B) inhibited tumor cell proliferation, soft‐agar colony formation and promoted cell differentiation (P<0.01). When implanted into SCID mice, miR24‐ 2 overexpressed Huh 7 and Hep3B cells formed smaller xenograft tumors. qRT‐PCR shows that TGFβ inhibits miR24‐2 expression and mature, which leads to pim1 (the predict target of miR24‐2) accumulation. And Pim1 inhibits the binding of Smad2‐Smad4 to P21/CIP1/WAF1 promoter. Taken together, our data suggest that miR24‐2 inhibits hepatoma cell growth and this effect is at least in part through Smad2/Smad4‐mediated induction of P21/CIP1/WAF1. MiR24‐2 tumor suppressor function is abrogated by TGFβ in the development of liver cancer.
Role of glutamine synthetase as a surrogate marker in predicting β‐catenin mutated hepatoceullar carcinoma
Authors: Lee Jung Min , Singh Sucha , Monga Satdarshan PS
Published: June 2021

Wnt/β‐catenin signaling is indispensible in cell growth and proliferation, but plays a role in development of hepatocellular carcinoma (HCC) when mutation occurs and the pathway becomes aberrantly activated. Nuclear/cytoplasmic (N/C) staining of β‐catenin significantly correlates with mutation of β‐catenin, and positive staining of glutamine synthetase (GS) is also suggested as a surrogate marker of β‐catenin mutation. In this study, we aimed to elucidate the relation between N/C staining of β‐catenin and GS staining in a large number of samples from a tissue array. Immunohistochemical staining for β‐catenin and GS was performed on slides of HCC tissue array, LV2082 by Biomax©, which included 94 samples in duplicate. In β‐catenin staining, 68 (72.3%) were positive for N/C pattern, 15 (16.0%) for membranous pattern, and 10 (10.6%) were negative. In GS staining, 30 (31.9%) were positive. Out of 30 GS positive cases, 27 (90.0%) showed positivity for N/C staining of β‐catenin. GS positive tissues had a high probability of having N/C staining of β‐catenin, and therefore GS staining could be potentially used as a surrogate marker for predicting β‐catenin mutated tumors.
Profiling candidate housekeeping genes for data normalization in chronic ethanol treated rat liver regeneration model
Authors: Juskeviciute Egle , Vadigepalli Rajanikanth , Hoek Jan B.
Published: June 2021

This study focuses on selecting suitable housekeeping genes (HKGs) to normalize gene expression data in the regenerating liver of the rats subjected to chronic ethanol treatment. Rats were fed a liquid diet containing 36% of total calories derived from ethanol for 5 weeks; for pair‐fed controls ethanol calories were replaced by carbohydrates. After five weeks, rats were subjected to 70% PHx and liver samples were collected at 1, 6, 12, 24, 36 and 48 h after the surgery.

Our global gene expression analysis indicates that almost 50% of hepatic genes are differentially expressed within the first 24 h after PHx. The ideal HKGs should be expressed at a constant level during different stages of liver regeneration and be unaffected by chronic ethanol treatment. We analyzed expression levels of 35 candidate HKGs using a high throughput microfluidic qPCR platform. This set included both traditional HKGs (Actb, Gapdh) and novel candidates selected based on our global gene expression data. Gene expression analysis using modified geNorm algorithm showed that only five of these genes could be considered suitable HKGs in this model. Results of our gene expression data analysis were significantly affected by the choice of HKGs. Our newly characterized HKGs improved the patterns identified for the cell cycle pathway demonstrating the functional validity of our approach.

Supported by AA018873, AA008714, AA014986, AA017261.
Effect of immuno modulator metallopeptide (IMMP) in acute toxic hepatitis induced with CCI4 in rats
Authors: Rodríguez-Fragoso Lourdes , Torres-Aguilar Lorena , Reyes-Esparza Jorge
Published: June 2021

Toxic hepatitis is a disease caused mainly by drugs or toxic agents. The IMMP is a drug with immunomodulatory properties and positive effects on the liver damage induced by autoimmune mechanisms and viral infections in patients and experimental models. For the study used 62 male Wistar rats (200 g), the animals were divided into twelve groups: 3control groups, 3 groups with IMMP, 3 groups with CCl4‐induced damage, and 3 groups treated with IMMP and damaged with CCl4. The IMMP was administered ip. at a dose of (100ng/Kg) and CCl4 was administered orally in single dose (4g/Kg). Animals were sacrificed at 24, 48 and 72 hours after CCl4 administration, we evaluated the levels of liver enzymes, glycogen, lymphocyte populations, glutathione, complete blood count (CBC) and liver weight. The IMMP restored alkaline phosphatase values in liver function tests, also stimulated the production of glutathione. The IMMP did not alter the levels of glycogen and lipid peroxidation in liver tissue damage. The IMMP showed a tendency to re‐establish normal values in CBC and liver weight. CD8+ and CD4+ lymphocytes increased with IMMP. In conclusion, the IMMP partially modified, acute toxic hepatitis.
Developing a completely biological tissue‐engineered blood vessel for clinical use
Authors: L'Heureux Nicolas
Published: June 2021

In the 1990's, biomaterials were considered an integral part of the new field of tissue engineering, particularly in projects where mechanical functions were important. However, these foreign scaffolds often significantly limited in vivo performance because they interfered with physiological functions (immune, remodeling, mechanical). Our goal was to grow a completely biological human blood vessel in the hope that it could be positively remodeled by the recipient's body.

Using normal adult skin fibroblasts, we developed an approach termed Tissue Engineering by Self‐Assembly (TESA) in which sheets of cell‐synthesized extracellular matrix and living cells are assembled into strong complex tissues. Multilamellar tubes where developed as autologous vascular grafts for hemodialysis access. These vessels displayed promising mechanical properties including burst pressures that surpassed those of human arteries. Phase I/II clinical trials have shown promising safety and efficacy results even in a high‐risk patient population. Early clinical results with a second‐generation graft (allogeneic, non‐living) support the feasibility of this more widely available design. A third generation graft, based on cell‐synthesized threads and textile technologies, can be produced three times fasters. This truly biocompatible “biomaterial” can mimic the conjunctive component of many tissues and organs.
Non‐coding RNAs: From scientist to patient and back
Authors: Carlin George
Published: June 2021

The newly discovered differential expression in numerous tissues, key cellular processes and multiple diseases for several families of long and short non‐codingRNAs (ncRNAs, RNAs that do not codify for proteins but for RNAs with regulatory functions), including the already famous class of microRNAs (miRNAs) strongly suggest that the scientific and medical communities have significantly underestimated the spectrum of ncRNAs whose altered expression has significant consequences in diseases. MicroRNA and other short or long non‐codingRNAs alterations are involved in the initiation, progression and metastases of human cancer. The main molecular alterations are represented by variations in gene expression, usually mild and with consequences for a vast number of target protein coding genes. The causes of the widespread differential expression of non‐codingRNAs in malignant compared with normal cells can be explained by the location of these genes in cancer‐associated genomic regions, by epigenetic mechanisms and by alterations in the processing machinery. MicroRNA and other short or long non‐codingRNAs expression profiling of human tumors has identified signatures associated with diagnosis, staging, progression, prognosis and response to treatment. In addition, profiling has been exploited to identify non‐codingRNAs that may represent downstream targets of activated oncogenic pathways or that are targeting protein coding genes involved in cancer. Recent studies proved that miRNAs and non‐coding ultraconserved genes are main candidates for the elusive class of cancer predisposing genes and that other types of non‐codingRNAs participate in the genetic puzzle giving rise to the malignant phenotype. Last, but not least, the shown expression correlations of these new ncRNAs with cancer metastatic potential and overall survival rates suggest that at least some member of these novel classes of molecules could potentially find use as biomarkers or novel therapeutics in cancers and other diseases.
Translating insights from development into regenerative medicine with a focus on Wnt Biology
Authors: Helms Jill Ann
Published: June 2021

Substantial progress has been made towards understanding the molecular machinery governing skeletal tissue development, repair, and remodeling. The next challenge is to determine how these findings can be translated into therapeutic strategies to enhance skeletal tissue regeneration. Such therapeutic strategies are oftentimes built upon the basic principles underlying bone development, because it has become increasingly evident that the mechanisms controlling fetal bone formation are similar to the mechanisms regulating adult bone repair and bone remodeling. Only the time scale and the extent/distribution of bone‐forming activity are different. For example, bone remodeling is a life‐long process that occurs within every skeletal element. Conversely, injury‐induced bone repair occurs within a compressed time frame and in a precise location. The cellular and molecular machinery governing osteoblast and osteoclast function, however, are indistinguishable. Consequently, studies that investigate how undifferentiated cells choose a chondrogenic or an osteogenic fate during fetal development provide a “window” into that same decision that occurs as part of adult repair and remodeling. Likewise, high bone mass diseases and osteoporosis are part of a continuum of bone remodeling, representing the extremes of too little or too much bone mass. With this perspective in mind, I will discuss a new perspective we have developed regarding skeletogenesis, viewing it as a cellular program that extends from the fetal period through to the end of life. I will focus on the roles of one pathway in particular, the Wnt family of secreted proteins, and how we have developed a therapeutic strategy to stimulate skeletal healing that is built on the well‐established role for Wnt signaling in stem cell self‐renewal, proliferation, and osteogenic differentiation.
Transcriptional and epigenetic regulation of lung development and regeneration
Authors: Morrisey Edward
Published: June 2021

Development of the respiratory system is controlled by a myriad of transcription factors and signaling pathways that interact to regulate various aspects of cell differentiation. The result is a highly organized system of airways closely aligned with the pulmonary vasculature that is required for postnatal respiration. How these transcription factors and signaling pathways interact to promote cell lineage fate and differentiation is poorly understood but likely involves epigenetic mechanisms. Our lab has recently focused on epigenetic mechanisms that regulate cell differentiation in the developing and regenerating lung. Published and unpublished data from our lab support important roles for miRNAs and HDAC mediated mechanisms that drive cell type differentiation in a spatial and temporal specific fashion in the developing lung. Moreover, some of these pathways play critical roles in lung regeneration and may provide important new therapeutic targets for human lung disease.
Stem cell‐derived motoneurons: Tools for studying motoneuron disease and motoneuron development
Authors: Rafuse Victor , Soundararajan Praba , Toma Jeremy
Published: June 2021

Ten years ago, Tom Jessell and colleagues demonstrated for the first time that mouse embryonic stem (ES) cells can be directed to differentiate into motoneurons by simply treating them in culture with two mitogens, retinoic acid and a sonic hedgehog (Shh) agonist. Since this seminal discovery there has been an explosion of research using motoneurons derived from human and mouse ES cells, as well as induced pluripotent stem (iPS) cells, to study motoneuron disease and development. My presentation will first focus on developmental studies where we exploited the fact that mouse ES cell‐derived motoneurons differentiate into a single subclass of motoneurons that selectively innervate postural muscles lining the vertebral column. We show that ES cell‐derived motoneurons are an ideal model system to examine intracellular signaling cascades regulating motor axon guidance during embryogenesis. Second, I will describe a novel in vitro model system to study synapse formation at the neuromuscular junction using ES cell‐derived motoneurons and chick myotube co‐cultures. Finally, I will explore the use of motoneurons directly derived from fibroblasts as a tool to study motoneuron diseases.
Secreted growth factors from human epicardial‐derived precursor cells protect against progressive injury after myocardial ischemia with reperfusion by preventing vascular rhexis
Authors: Spees Jeffrey L
Published: June 2021

Paracrine effects are thought to provide many benefits of cardiac stem/progenitor cell administration, but the key secreted factors and physiological mechanism(s) of their action are poorly understood. Epicardial‐derived precursor cells (EDPCs) support cardiac development, repair and remodeling after injury, in part through paracrine activity. Accordingly, we determined whether factors secreted by human EDPCs into conditioned medium (EPI CdM) would protect jeopardized cardiac tissue after myocardial infarction (MI) with reperfusion. Injection of human EPI CdM markedly reduced infarct size (by 50%) in multiple mouse strains, even after 4 hours of ischemia. Combined depletion of HGF, VEGFA, and SDF‐1 from EPI CdM prior to treatment showed that it protected jeopardized myocardium by preventing the loss of vascular integrity (rhexis) after reperfusion. Our results demonstrate that the paracrine effects of EDPCs are likely to occur through the concerted effects of multiple secreted factors. Based on its ability to protect against vascular rhexis, EPI CdM or a combination of its ligands may provide an effective treatment for acute MI.
Myocardial Notch Signaling Reprograms Cardiomyoctes to a Conduction‐Like Phenotype
Authors: Rentschler Stacey , Yen Alberta , Lu Jia , Petrenko Nataliya , Patel Vickas V , Fishman Glenn I , Epstein Jonathan A
Published: June 2021

Notch signaling has previously been shown to play an essential role in regulating cell fate decisions in many systems. We hypothesized that Notch may be involved in directing the progressive lineage restriction of cardiomyocytes into specialized conduction cells. In murine hearts where Notch signaling is activated within the myocardium from early development onwards, Notch promotes a conduction‐like phenotype as evidenced by ectopic expression of conduction system‐specific genes, as well as cell autonomous changes in cellular electrophysiology. Activation of Notch in newborn ventricular cardiomyocytes from Contactin2‐EGFP transgenic mice, which specifically labels conduction cells, demonstrates Notch‐induced changes in “chamber” ventricular cardiomyocytes consistent with a phenotypic switch to Purkinje‐like cells, including transcriptional changes, action potential prolongation and hyperpolarization of the resting membrane potential. Taken together, this suggests that Notch can instruct the differentiation of cardiac progenitors into specialized conduction‐like cells and that this plasticity remains in late‐stage cardiomyocytes, which has potential implications for engineering of specialized cardiovascular tissues.

Grant Funding Source: Career Award for Medical Scientists Burroughs Wellcome Fund and K08 HL107449‐01 to SR, U01 HL100405‐1 to JAE
Control of Growth by the mTOR Pathway
Authors: Sabatini David
Published: June 2021

mTOR is the target of the immunosuppressive drug rapamycin and the central component of a nutrient‐ and hormone‐sensitive signaling pathway that regulates cell growth and proliferation. We now appreciate that this pathway becomes deregulated in many human cancers and has an important role in the control of metabolism and aging. We have identified two distinct mTOR‐containing proteins complexes, one of which regulates growth through S6K and another that regulates cell survival through Akt. These complexes, mTORC1 and mTORC2, define both rapamycin‐sensitive and insensitive branches of the mTOR pathway. I will discuss new results from our lab on the regulation and functions of the mTORC1 and mTORC2 pathways.
Dissecting Cellular Necrosis Pathways
Authors: Wang Xiaodong
Published: June 2021

The programmed necrosis induced by TNF‐α family of cytokines requires the activities of the receptor interacting serine‐threonine kinases RIP1 and RIP3. Such form of cell death has now recognized to have important roles in animal development, tissue damage response, and innate immunity against microbes. How RIP kinases cause cell death is not known. In this meeting, I plan to discuss our recent progress in dissecting the molecular pathway downstream of RIP3 activation using a combination of tools from chemical biology, biochemistry and live cell imaging. We are able to map a necrotic pathway with discrete biochemical steps leading to the characteristic changes associated with necrosis. Moreover, we have identified a necrosis execution step that seems to be the convergent point of multiple necrosis pathways including necrosis induced by reactive oxygen species (ROS) and calcium overload.
Fungal SREBPs: Hypoxic Transcription Factors Required for Pathogenesis
Authors: Espenshade Peter
Published: June 2021

Sterol regulatory element binding proteins (SREBPs) are membrane‐bound transcription factors that control cellular lipid homeostasis. Fungal SREBPs additionally act as hypoxic transcription factors and are required for adaptation to low oxygen environments. Studies in opportunistic fungal pathogens revealed that SREBPs are required for virulence in mouse models of disease, making the SREBP pathway an antifungal therapeutic target. Our studies in fission yeast defined two independent mechanisms by which oxygen controls SREBP activity and identified molecular machinery essential for SREBP pathway function. These studies reveal important similarities and differences between fungi and mammals that have implications for treatment of fungal disease.
Linking the DEAD‐box RNA helicase Ded1p to cellular RNA targets
Authors: Jankowsky Eckhard
Published: June 2021

RNA helicases are ubiquitous, highly conserved enzymes that participate in nearly all aspects of eukaryotic RNA metabolism. In vitro, helicases bind or remodel RNA or RNA‐protein complexes in an ATP‐dependent fashion, but how these activities are used in the cellular function of these enzymes has remained elusive. This is mainly because RNA targets and binding sites on these targets are not known. Here, we identify RNA targets and binding sites of the yeast DEAD‐box RNA helicase Ded1p, using an approach that combines in vivo crosslinking, affinity purification and Next Generation Sequencing. Ded1p had been implicated in translation initiation, and we find that the enzyme binds to essentially all expressed mRNAs, at multiple sites on each RNA. While the binding sites do not show identifiable sequence motifs, different binding sites on a given RNA can form short helices, and mutational analysis of the binding sites in select mRNA supports the existence of these interactions. Our data suggest that Ded1p acts as a general translation initiation factor and that the enzyme impacts higher order structure of mRNAs.
Group II intron architecture and its implications for the development of eukaryotic splicing systems
Authors: Pyle Anna Marie
Published: June 2021

Group II introns are self‐splicing RNA molecules that have played an important role in the evolution of terrestrial genome organization. After splicing, free group II introns are liberated into the cell, where they behave as mobile genetic elements that insert themselves into new RNA or DNA sites. As a result of this behavior, the introns have spread throughout bacteria and eukaryotic lineages, diversifying organisms through the insertion of new introns and by evolving into new types of splicing machinery. The eukaryotic spliceosome is believed to have evolved from an ancestral group II intron that was absorbed during an early endosymbiont event. The functional relationship between group II introns and the spliceosome has long been supported by similarities in splicing mechanism and conserved RNA secondary structures. Recent crystallographic studies of group II introns have provided a high resolution view of active‐site organization, resulting in additional evidence that group II‐like components lie within the catalytic heart of the eukaryotic spliceosome.
Small molecule “on” and “off” switches for autophagy
Authors: Xia Hongguang , Liu Junli , Kim Minsu , Li Ying , Vakifahmetoglu-Norberg Helin , Ma Dawei , Yuan Junying
Published: June 2021

Autophagy, a lysosome‐dependent catabolic process involved in the turnover of cellular components, mediates normal homeostasis during development and protects multicellular eukaryotes from neurodegeneration, cancer and other diseases. However, the mechanisms regulating autophagy under normal nutritional conditions most frequently encountered by cells in organisms under physiological conditions remain unknown. During the past four years, we have used small molecules as tools to explore the regulatory mechanisms that lead to both activation (“on”) and inhibition (“off”) of autophagy in mammalian cells. We have discovered a molecular mechanism for small molecules which can act as an “on” switch for activating autophagy by regulating intracellular Ca2+ current and calpain1 regulated ATG5 cleavage under normal nutritional conditions. Furthermore, we have explored the targeting mechanism of spautin‐1, a small molecule “off” switch for autophagy, and discovered a novel protein deubiquitination mechanism that regulates the turnover of Vps34 complexes, the class III PI3 kinase that plays an essential role in mediating autophagy. Using spautin‐1 as a tool, we elucidated an unexpected connection beclin1, the class III PI3 kinase and tumor suppressor p53, providing an important molecular mechanism that directly links autophagy with tumor suppression.
Using C. elegans to dissect fat and feeding regulatory pathways
Authors: Ashrafi Kaveh
Published: June 2021

Fat regulation involves a complex interplay between feeding centers in the nervous system and the transport, storage and mobilization of fat in the periphery. Using mutagenesis and genome‐wide RNAi studies, we previously identified over 400 genes that regulate fat levels in C. elegans. These include components of neuroendocrine signaling, channels and transporters, transcription, metabolism and many genes with previously unassigned functions. Our findings highlight the shared ancestry of C. elegans and mammalian fat regulation. More importantly, this work identifies hundreds of new genes that participate in novel fat regulatory pathways. We have now undertaken the daunting task of understanding the modes of function of these fat regulatory genes within the context of intact organisms. These genes affect functions as diverse as metabolism and behavior.

I will discuss our latest findings in dissecting the neural circuits that modulate feeding behavior and fat metabolism in C. elegans. These data will include roles for the C. elegans counterparts of human obesity genes as well as utility of C. elegans in identifying novel small molecule entities that modulate fat metabolism
The Mediator of RNA Polymerase II Transcription: Links to Transcription Elongation and Leukemogenesis
Authors: Conaway Joan W , Takahashi Hidehisa , Parmely Tari J. , Tomomori-Sato Chieri , Sato Shigeo , Conaway Ronald C.
Published: June 2021

Promoter proximal pausing by initiated RNA polymerase II (Pol II) and regulated release of paused polymerase into productive elongation has emerged as a major mechanism of transcription activation. Reactivation of paused Pol II has been shown to correlate with recruitment of a Super‐Elongation Complex or SEC that contains the transcription elongation factors ELL/EAF and P‐TEFb, as well as a collection of additional proteins encoded by genes involved in translocations with the MLL gene in leukemia. Our lab has recently obtained evidence for a role of human Mediator in recruiting SEC and another ELL/EAF‐containing complex to genes. In particular, we have shown that a conserved N‐terminal domain in the Mediator subunit Med26 provides docking sites for ELL/EAF, P‐TEFb, and associated proteins as well as the general initiation factor TFIID. Our findings are consistent with the model that Med26 functions as a molecular switch that interacts first with the Pol II initiation complex through direct interactions with TFIID and then “exchanges” TFIID for complexes containing elongation factors ELL/EAF and P‐TEFb to facilitate the transition of Pol II into the elongation stage of transcription.
Inhibitors of heat shock proteins in cancer treatment
Authors: Chiosis Gabriela
Published: June 2021

In many diseases, among which cancer and neurodegeneration, the development of a pathogenic phenotype is associated with dysregulation of multiple pathways and molecules. To adapt, cells co‐opt heat shock proteins (HSPs) to help maintain a functional cellular state under the transforming pressure. As such, cancer cells often express high levels of several HSPs, which augment the aggressiveness of these tumors and also allow the cells to survive lethal conditions, including killing by therapies. In addition to conferring resistance to treatment, elevated HSP expression also facilitates cancer by inhibiting programmed cell death and by promoting autonomous growth. Among the major HSPs are Hsp90 and Hsp70, proteins that act in an interconnected but also distinct fashion to regulate the malignant phenotype. Consequently, approaches that target these HSPs are especially powerful in treating cancer and in overcoming resistance to current treatments. This talk will present some of our efforts in the design, development and clinical translation of these inhibitors as potential novel therapies in cancer.
Cultivating Class Discussions and Interest in Scientific Research Through the Acknowledgment of Cultural Dichotomies
Authors: Martin Estralita M.E.
Published: June 2021

Many college of science faculty are discouraged from using innovative methods to increase the presence of diversity in science careers. The typical scientific culture values research productivity over teaching and learning. During my work with urban science students, three methodologies have emerged as students develop mental, verbal, and physical models for understanding complex scientific phenomena. First, students’ socio‐cultural experiences and colloquialisms are incorporated into the curricula. Everything from student discourse, favorite movies, and familiar experiences are used as examples, analogies, prompts and assignments when students are asked to gather information and do research. Second, students learn through discourse and use what they know to solving novel problems. Therefore, for a number of different assignments, students are placed in groups with peers within or outside their social groups or cultural backgrounds and asked to discuss their thoughts and ideas. Finally, in order to facilitate course discussions and the construction of scientific information, students are instructed to mediate their cultural capital with their research interests. As a result of these pedagogical and conceptual approaches, students are engaged in class discussion, research, and scientific content. Students remember more and are interested in conducting collaborative scientific research.
Systems biology approach in pathway analysis of low dose flagellin induced tolerance to flagellin‐stimulated inflammation in caco‐2 cells
Authors: Li Nan , Kobeissy Firas , Quidgley Maria C , Neu Josef
Published: June 2021

Our previous study showed that low dose flagellin (LDFL) promotes tolerance to pathogenic ligand flagellin (HDFL)‐induced IL‐8 production in Caco‐2 cells. HDFL at 500 ng/ml increased IL‐8 by 19 fold and pretreatment with LDFL at 10 ng/ml reduced HDFL‐induced IL‐8 by 52%. Using a signaling pathway microarray and systems biology analysis, the toll‐like receptor (TLR) and closely related pathway genes were evaluated. Caco‐2 cells were pretreated with or without LDFL at 10 ng/ml for 24 hours, and then followed with HDFL 500 ng/mL for 48 hours. Eighty four genes in the TLR pathway were evaluated by RT PCR Array. Pathway Studio 8.0 software was used for altered pathway analysis. The network was generated using the “direct interaction” algorithm to map cellular process and interactions between altered genes. HDFL up‐regulated IL8, IL1B, CXCL10, IRAK2, I‐κB and NF‐κB. Pathway Studio analysis showed that HDFL induced cell processes including inflammation, cell death and apoptosis. Pretreatment with LDFL down‐regulated FADD, FOS, MAP4K4, MyD88, TLR2, TLR3 and TNFERSF1A compared to HDFL. These down‐regulated genes are integral for numerous cell functions including inflammatory response, cell death, apoptosis and infection. The tolerance effect to IL‐8 was accompanied by a systemic interaction of multiple genes related to inflammatory as well as other responses in the TLR pathway rather than a single gene alteration.
Flavored milk is not associated with excess weight gain in children and adolescents
Authors: Egan Kara A , McCabe George P , Martin Berdine R , Hyner Gerald C , McCabe Linda D , Weaver Connie M
Published: June 2021

In an effort to meet the dietary standards established in the HealthierUS School Challenge, numerous schools have eliminated flavored milk from cafeterias. We tested the hypothesis that intake of flavored milk would be associated with body weight and weight gain during a dairy intervention in 130 healthy and overweight 4th through 8th grade boys and girls. Using bi‐weekly dairy order records and self reported dairy consumption, we quantified milk consumption, flavored and white, over six months, and compared that with measured changes in height and weight from baseline. Both total (r = −0.17, p = 0.06) and flavored (r = −0.17, p = 0.05) milk consumption were negatively correlated with body weight at baseline. ANOVA showed no significant differences in weight gain during the follow‐up period between subjects who consumed less than 1 cup, 1 to 5 cups, or greater than 5 cups of flavored milk per week (0.50, 0.42, and 0.52 kg per month, respectively, p=0.704). Similar results were observed when assessing BMI. This study suggests that flavored milk should not be removed from school cafeterias because of the perception that it contributes to childhood obesity.

Grant Funding Source: Dairy Management Inc.
Different analysis methods reveal different effect of national school lunch program on childhood obesity in the US
Authors: Xue Hong , Wang Youfa
Published: June 2021

Background

The impact of national school lunch program (NSLP) on the US childhood obesity epidemic is controversial, while NSLP is widely viewed critical to help school children improve dietary intake and develop lifelong healthy eating habits. Using national data, we studied the effects of NSLP on childhood obesity.

Methods

National Health and Nutrition Examination Survey (NHANES) 1999–2008 data of school‐age children (5–19 y) were used in a longitudinal‐type analysis framework accounting for unobserved effects with the application of difference‐in‐differences (DID) estimator. We calculated Healthy Eating Index (HEI, USDA 2005) scores using the 24‐hour recall data to evaluate the NSLP participants’ vs non‐participants’ dietary quality.

Results

Our analysis indicates significant influence of unobservables on the estimates of the effects of NSLP on BMI and obesity. NSLP participation was associated with increased BMI‐Z score by 0.1(SE=0.04, p<0.01), but the effect disappeared after corrected for unobservable effects. NSLP participation was positively associated with dietary quality (beta=1.04, SE=0.4, p<0.05) and total fruit consumption (beta=0.41, SE=0.07, p<0.01). Calories from solid fat, alcohol and added sugar were not higher for NSLP participants.

Conclusions

Our analysis does not suggest an association between NSLP and childhood obesity. NSLP participants had a healthier diet.

Grant Funding Source : NIH/NICHD (U54 HD070725‐01, 1R01HD064685‐01A1) and NIDDK (R01DK81335‐01A1)
Metabolic production of methylated selenium species requires adequate methylation status
Authors: Jackson Matthew I , Gabel-Jensen Charlotte , Lunge Kristoffer , Gammelgaard Bente , Combs Gerald F
Published: June 2021

Obesity negatively impacts methylation status and markers of methylation status vary according to selenium status in supplemented subjects. We have proposed that disruptions in methylation capacity induced by obesity compromise demonstrable anti‐cancer effects of Se supplementation. In order to address this hypothesis, we performed studies to determine if a systemic disruption in methylation capacity alters the distribution of methylated Se species. We intraperitoneal injected rats with selenite alone or in combination with an inhibitor of adenosylhomocysteine hydrolase (POA), and analyzed markers of methylation capacity as well as methylated Se species in various tissues. Results show that POA treatment disrupted S‐adenosylmethione (SAM):S‐adenosylhomocysteine (SAH) ratios in liver and kidney without significantly affecting homocysteine, folate or vitamin B12 concentrations. That treatment also altered, to varying degrees, the distributions of trimethylselenonium ion, a galactopyranoside selenosugar, Se‐methylselenocysteine and selenomethionine in liver, kidney and urine, demonstrating that disrupted methylation capacity affects Se metabolism. That this phenomenon may affect Se‐antitumorigenicity is suggested by the fact that these methylated Se species are metabolically related to methylselenol, which has been shown to have anti‐carcinogenic activity.
A fatty acid desaturase expression quantitative trait locus modulates response to simvastatin
Authors: Reardon Holly T. , Zhang Jimmy , Kothapalli Kumar S.D. , Kim Andrea J. , Park Woo Jung , Brenna J. Thomas
Published: June 2021

The FADS1 and FADS2 genes encode fatty acid desaturases required for synthesis of omega‐3 and omega‐6 long‐chain polyunsaturated fatty acids (LCPUFA) important in cardiovascular health. Single nucleotide polymorphisms (SNPs) in these genes are associated with many health outcomes, but mechanisms are unclear. Here, lymphoblast expression microarray results from Japanese in Tokyo International HapMap participants were associated with SNPs in the FADS gene cluster. A 10‐SNP haplotype in FADS2 present in 24% of the population was significantly associated with lower FADS1 expression. A highly conserved region coinciding with the most significant SNPs contained predicted binding sites for PPARγ and SREBP. Lymphoblasts homozygous for the major or minor haplotype were treated with agonists for these transcription factors. Minor haplotype homozygotes had 20–40% higher induction of FADS1 and FADS2 after treatment with the statin drug simvastatin or LXR agonist GW3965, suggesting enhanced responsiveness to SREBP‐1c. Sequencing of the region identified two deletion mutations within 150 bp of the putative sterol response element in minor haplotype carriers. Individuals carrying these deletions may be particularly vulnerable to low dietary LCPUFA, and may be especially responsive to statin or marine oil therapy. SUPPORT: Grant# T32HD052471 from the National Institutes of Child Health and Human Development.
Caloric restriction and exercise lower plasma triglycerides by different mechanisms
Authors: Sidossis Labros S , Bellou Elena , Maraki Maria , Siopi Aikaterini , Galani Maria , Magkos Faidon , Kavouras Stavros A
Published: June 2021

Exercise decreases plasma triglyceride (TG) concentration by increasing very low‐density lipoprotein triglyceride (VLDL‐TG) clearance. The purpose of this study was to examine the mechanism responsible for the TG‐lowering effect of dietary energy restriction. Nine young, lean women underwent tracer infusion studies in the morning after: i) one day of dietary energy restriction of 2.05±0.44 MJ (~500 kcal), ii) a single exercise bout (brisk walking at 60% of peak oxygen consumption for ~2 h; net energy expenditure of 2.0±0.4 MJ), and iii) control (no energy restriction or exercise) in a random order. Fasting plasma VLDL‐TG concentrations were significantly lower after diet (0.18±0.07 mmol/L) and exercise (0.17±0.05 mmol/L) compared to control (0.23±0.07 mmol/L). Diet decreased hepatic VLDL‐TG secretion rate by 19% (P<0.03) but did not affect clearance. In contrast, exercise increased clearance by 18% (P<0.01) but did not affect VLDL‐TG secretion rates. VLDL particle concentration was significantly lower after diet and exercise compared to control (P<0.01). HDL particle size increased after exercise but not diet (P<0.01). We conclude that dietary energy restriction and exercise decrease plasma TG by different mechanisms. This is clinically significant because it lays the foundation for an individualized approach to treating hypertriglyceridemia, based on patient preferences and abilities.
Aging is a more significant determinant of hepatic DNA methylation patterns than a Western style diet
Authors: Park Lara Kristin , Saltzman Edward , Schnitzler Gavin , Yoon Byung Woo , Parnell Laurence D. , Lai Chao Qiang , Choi Sang-Woon
Published: June 2021

We investigated how DNA methylation patterns change with aging and a Western style diet (WSD) in the liver. 2‐month old male C57BL/6 mice were randomized to control diet (CD) or WSD for either the following 6 (young) or 18 months (old). WSD is high in fat and low in fiber, vitamins and minerals. Methylation was investigated by the methylated DNA immunoprecipitation‐chip method on arrays covering all RefSeq genes and CpG islands. Modified t‐tests with the Benjamini‐Hochberg (BH) correction for multiple comparisons (α=0.05) were performed per probe for age and diet contrasts. Within n=713,168 probes, we found 17.0% and 8.7 % significant probes by age within CD and WSD, respectively. Ingenuity Pathway Analysis identified similar patterns by aging in WSD and CD with enrichment of genes in cancer, lipid metabolism, epigenetic regulation and neural function. Specifically, we observed hypermethylation of the Jumonji subunit Kdm6b and hypomethylation of Ras member Rap2a, cholesterol metabolism enzyme Hsd3b5, mitochondrial metabolism enzyme Suclg1 and multiple olfactory and vomeronasal receptors. No significant probes passed BH when comparing diets at the same age. Thus, aging has a greater effect than diet on hepatic DNA methylation patterns with enrichment of genes that may potentiate chronic disease development. Gene expression remains to be evaluated. Supported by NIH Grants R01 AG25834.

Grant Funding Source: NIH
Urinary acid excretion can predict changes in bone metabolism during space flight
Authors: Zwart Sara R. , Heer Martina , Smith Scott M.
Published: June 2021

Mitigating space flight‐induced bone loss is critical for space exploration, and a dietary countermeasure would be ideal. We present here preliminary data from a study in which we examined the role of dietary intake patterns in bone mineral loss of astronauts during space flight. Crew members (n=5) were asked to consume a prescribed diet with either a low (0.3–0.6 g/mEq) or high (1.0–1.3 g/mEq) ratio of animal protein to potassium (APro:K) before and during space flight for 4‐d periods. Diets were controlled for energy, total protein, calcium, and sodium. On the last day of each of the 4‐d controlled diet sessions, 24‐h urine samples were collected. Dietary potential renal acid load was used to predict 24‐ h urinary acid excretion, which was correlated with urinary n‐telopeptide (NTX, Pearson R = 0.99 and 0.80 for the high and low APro:K sessions, respectively, p<0.001). The amount of protein, when expressed as the percentage of total energy (but not as total grams) was also correlated with urinary NTX (R = 0.66, p<0.01). These results, from healthy individuals in a unique environment, will be important for better understanding diet and bone interrelationships during space flight as well as on Earth. The study was funded by the NASA Human Research Program.
Identification of Human‐Flavonoid Targets Using an Innovative Approach Reveals New Mechanisms Involved in Their Anti‐Inflammatory Activities
Authors: Arango Daniel , Morohashi Kengo , Yilmaz Alper , Brahimaj Bledi , Kuramochi Kouji , Grotewold Erich , Doseff Andrea I.
Published: June 2021

Flavonoids are dietary nutraceuticals with anti‐carcinogenic, chemopreventive, and anti‐inflammatory activities. We showed that apigenin, a flavone broadly found in fruits and vegetables, has anti‐inflammatory activity in vitro and in a mouse model of inflammation through the regulation of NF‐κB. However, its molecular mechanisms of action remain unknown. The goal of this study was to identify the human cellular targets of apigenin. We developed and implemented a novel approach coupling phage‐display with next‐generation sequencing (PD‐Seq) to identify human cellular targets of apigenin. Targets were validated using competition and pull down assays, with purified GST and GFP‐tagged proteins and cellular lysates. Development of a FRET‐nanosensor using a newly identified target provided insightful structure‐binding relationships of flavonoids. Molecular cell‐based studies showed that the apigenin target plays central roles in inflammation and reveals novel aspects on how nutraceuticals regulate immunity. Altogether, these results suggest that the innovative use of phage display in combination with next‐generation sequencing provides a robust method to identify novel targets of flavonoids. The findings reveal novel aspects on how nutraceuticals regulate biological activities providing better insights for the rational development of functional foods.

Grant Funding Source : This work was supported by Grants RO1HL075040‐01 and NSF‐MCB‐0542244 to AID and by OSUPHPID fellowship to DA
Pomegranate ellagitannin metabolite, Urolithin A, inhibits prostate cancer cell proliferation via inhibition of IGF‐1 signaling pathway
Authors: Vicinanza Roberto , Zhang Yanjun , Henning Susanne M. , Ma Janice , Heber David
Published: June 2021

Colonic microflora convert pomegranate ellagitannins (ETs) to ellagic acid (EA) and urolithins, primarily Urolithin A (UA). We previously demonstrated that EA and UA synergistically inhibited prostate cancer (PCa) cell growth via different mechanisms on the cell cycle. Insulin like growth factor‐1 (IGF‐1) is a potent mitogen that may activate PI3K/AKT and MAPK/ERK signaling to modulate cell cycle and proliferation. Here, we examined the effects of UA and EA on IGF‐1‐induced cell proliferation, PI3K/AKT and MAPK/ERK signaling in PCa cells. DU‐145 cells were treated for 48h with IGF‐1 (20ng/mL) with or without EA (from 3.75μM to 15μM) and UA (from 15μM to 60μM). EA and UA significantly decreased cell growth in a concentration dependent manner (p<0.001), and their combination exhibited synergism (combination index 0.378±0.043). Western blot analysis showed that EA significantly decreased basal levels of p‐ERK1/2 and p‐AKT at ser.473, while UA decreased p‐AKT at both ser.473 and thr.308. UA, but not EA, further impaired the IGF‐1‐induced AKT and ERK1/2 phosphorylation suggesting that UA inhibited cell growth by interfering with IGF‐1 signaling, providing new insights into the molecular mechanisms of ETs.