bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulated quality control in physiological regulation of cellular processes: lessons from regulated ERAD of HMG‐CoA reductase (353.3)
Authors: Neal Sonya , Ornelas Lilia , Ruckstuhl Maxwell , Singh Amanjot , Tang Xin , Vashista Nidhi , Wangeline Maggie , Hampton Randolph
Published: June 2021

Degradation of misfolded proteins occurs with extreme specificity, such that subtle changes in protein folding state can convert an otherwise stable protein into a robust substrate. E3 ligases that execute degradative protein quality control must detect a wide variety of common structural features in the absence of primary sequence similarity. While degradative quality control pathways serve a central function of removing potentially toxic misfolded proteins, the high specificity of QC degradation has been harnessed to regulate the levels of normal proteins. This idea is exemplified by cellular control of a rate‐limiting enzyme of the sterol pathway, HMG‐CoA reductase. HMGR is subject to ER‐associated protein degradation (ERAD) as part of the conserved strategy for regulated the levels of the normal protein. Studying this process helps us map the crossroad of protein quality control and protein regulation. We will describe the conserved HRD ERAD degradation pathway, and how this pathway is employed to regulate yeast HMGR isozyme Hmg2 by selective ligand‐mediated misfolding as a strategy to harness the high specificity of the HRD pathway to control sterol synthesis. A variety of new findings about this regulatory axis will be discussed and a variety of examples from diverse cellular process will be discussed that also harness protein quality control as a regulatory strategy.
Bridging protein structure and intrinsic function in cell signaling (354.3)
Authors: Sivaramakrishnan Sivaraj
Published: June 2021

A key problem in dissecting cell signaling is the numerous dynamic interactions between proteins integrated in signaling networks. While biochemical and structural studies provide detailed insights that can be exploited for drug discovery, they often ignore the complexity of the cellular environment in which small molecules need to function. In contrast, functional assays typically examine a single end‐point that can be influenced by several regulatory events. The Sivaramakrishnan lab addresses these limitations with the use of two novel technologies. First, a technique termed Systematic Protein Affinity Strength Modulation (SPASM; Sivaramakrishnan and Spudich, PNAS, 2011) provides a systems biology approach to understand the significance of individual regulatory interactions in a cellular context (Ritt et al., J. Biol. Chem, 2013; Malik et al., J. Biol. Chem, 2013). Second, protein interactions are engineered on DNA nano‐scaffolds with the goal of reconstituting multi‐protein signaling complexes in order to understand their emergent behavior. These technologies are being applied to understand several components of signaling cascades, including GPCRs and protein kinases. The talk will highlight conceptual insights gained from these methodologies, with a focus on leveraging these tools to identify highly selective allosteric modulators of cell signaling cascades.
Activity‐based proteomics ő applications for enzyme and inhibitor discovery (357.1)
Authors: Cravatt Benjamin
Published: June 2021

Genome sequencing projects have revealed that eukaryotic and prokaryotic organisms universally possess a huge number of uncharacterized enzymes. The functional annotation of enzymatic pathways thus represents a grand challenge for researchers in the genome era. To address this problem, we have introduced chemical proteomic and metabolomic technologies that globally profile enzyme activities in complex biological systems. These methods include activity‐based protein profiling (ABPP), which utilizes active site‐directed chemical probes to determine the functional state of large numbers of enzymes in native proteomes. In this lecture, I will describe the application of ABPP and complementary proteomic methods to discover and functionally annotate enzyme activities in mammalian physiology and disease. I will also present competitive ABPP platforms for developing selective inhibitors for poorly characterized enzymes and discuss ongoing challenges that face researchers interested in assigning protein function using chemoproteomic methods.
Phosphatidylinositol (4,5)‐bisphosphate regulates psychostimulant behaviors via a membrane protein interaction (358.1)
Authors: Galli Aurelio
Published: June 2021

Phosphatidylinositol (4,5)‐bisphosphate (PIP2) tightly regulates the function of ion channels and ion transporters. The human dopamine (DA) transporter (hDAT) is a key regulator of DA homeostasis and is a target of the psychostimulant amphetamine (AMPH). Here, we demonstrate that PIP2 interacts electrostatically with specific hDAT positively charged residues and that this direct electrostatic interaction facilitates AMPH‐induced, DAT‐mediated DA efflux and the psychomotor properties of AMPH. Substitution of these residues with uncharged amino acids reduces hDAT‐PIP2 interactions and AMPH‐induced DA efflux, without altering hDAT physiological function, DA uptake. We evaluated, for the first time, the significance of this interaction in vivo using locomotion as a behavioral assay in Drosophila melanogaster. Expression of mutated hDAT with reduced PIP2 interaction in DA Drosophila neurons impairs AMPH‐induced locomotion without altering basal locomotion. We present the first demonstration of how PIP2 interactions with a membrane protein regulate organismal behaviors, such as locomotion.
Structural and mechanistic insights into the SAGA coactivator complex (361.1)
Authors: Wolberger Cynthia
Published: June 2021

SAGA is a transcriptional coactivator complex that is conserved across eukaryotes and carries out multiple functions during transcriptional activation and elongation, including deubiquitination of histone H2B and histone acetylation. The deubiquitinating activity of SAGA resides in a distinct subcomplex called the deubiquitinating module (DUBm), which contains the ubiquitin‐specific protease, Ubp8, bound to Sgf11, Sus1 and Sgf73. Although Ubp8 contains a canonical USP isopeptidase domain, all four DUB module proteins are required for activity. Our structural studies of the DUB module revealed an unusual arrangement of non‐globular proteins bound to Ubp8 that give rise to a highly interconnected complex, in which each protein contacts the other three. These studies shed light on the contributions of Sgf11 and Sgf73 in regulating Ubp8 activity. One of the key features of the complex is the zinc finger domain of Sgf11, which binds near the catalytic site of the USP domain of Ubp8. Mutations and deletions of the region affect both enzymatic activity and gene activation, suggesting a dual role in activating Ubp8 and chromatin targeting. Structural and solution studies of the DUB module lacking the Sgf11 zinc finger reveal a surprising role for this domain in stabilizing the overall organization and proper folding of the entire DUB module, whereas point mutations in this domain point to its role in governing interactions with the nucleosome as well with polyubiquitin chains. We will describe the implications of these finding for understanding the overall interdependence of SAGA subunits and how they are targeted to the appropriate chromatin target during transcription.
All it takes to express virulence genes (361.3)
Authors: Artsimovitch Irina , Liu Zhaokun , NandyMazumdar Monali , Tomar Sushil
Published: June 2021

Horizontal gene transfer shapes bacterial evolution, enabling adaptation to new environments, efficient pathogenesis, and acquisition of antibiotic resistance. However, expression of foreign DNA may have detrimental, and even lethal, cellular effects, and is thus tightly regulated. In Escherichia coli, NusG and its specialized paralog RfaH play opposite roles in expression of horizontally‐transferred genes: NusG cooperates with a termination factor Rho to silence transcription of foreign DNA, whereas RfaH activates several long laterally acquired operons that encode cell wall and capsule biosynthesis machineries as well as secreted toxins. RfaH‐dependent operons lack Shine‐Dalgarno elements and have many rare codons, suggesting that they are translated inefficiently. Consistently, Rho decreases expression of a model rfb operon >700 fold. RfaH, when present, eliminates Rho‐mediated polarity by three mechanisms. First, RfaH decreases RNA polymerase pausing, making it resistant to Rho. Second, RfaH excludes NusG from the transcription elongation complex, thereby inhibiting Rho‐mediating RNA release. Third, RfaH directly interacts with the ribosomal protein S10 and appears to recruit the 30S subunit to mRNA instead of a Shine‐Dalgarno element. Together, these three mechanisms ensure robust expression of RfaH‐dependent genes required for virulence in some enterobacterial pathogens. RfaH paralogs are also present on large conjugative plasmids, suggesting their broad role in activation of horizontally‐transferred genes.
Mechanistic insights on the preprotein translocase: a single molecule study (362.4)
Authors: Driessen Arnold
Published: June 2021

The heterotrimeric SecYEG complex comprises a protein‐conducting channel in the bacterial cytoplasmic membrane. SecYEG functions together with the motor protein SecA in preprotein translocation. SecYEG can also associate with a translating ribosome to mediate membrane protein insertion. We have used single molecule techniques, fluorescence spectroscopy and advanced membrane protein reconstitution methods to address mechanistic and structural questions on the protein translocase with the challenge to visualize single protein translocation events.
Metformin ameliorates diet‐induced hepatic steatosis and inflammation without altering adipose phenotype (37.1)
Authors: Woo Shih‐Lung , Xu Hang , Li Honggui , Guo Xin , Guo Ting , Qi Ting , Huo Yuqing , Wu Chaodong
Published: June 2021

Non‐alcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis and inflammation, and is closely associated with obesity. We examined the effects of metformin on hepatic steatosis and inflammation to elucidate the possible protective mechanisms of metformin actions. Wild‐type C57BL/6J mice were fed a high‐fat diet (HFD) for 12 weeks and treated with metformin (150 mg/kg/d) orally for the last four weeks of HFD feeding. We found that metformin improved glucose tolerance and insulin sensitivity, and decreased liver weight and hepatic steatosis but not adiposity of HFD‐fed mice compared with controls. Additionally, metformin increased the phosphorylation of liver AMP‐activated protein kinase (AMP) and decreased the phosphorylation of liver c‐Jun N‐terminal kinase 1 (JNK1) and the mRNA levels of lipogenic enzymes and proinflammatory cytokines. These changes were not observed in adipose tissue. In cultured hepatocytes, metformin increased AMPK phosphorylation and decreased fat deposition and inflammatory responses. In cultured macrophages, metformin partially blunted the stimulatory effects of lipopolysaccharide on JNK1 and nuclear factor kappa B p65 phosphorylation and cytokine expression. Thus, metformin protects against NAFLD largely through direct effects on decreasing hepatocyte fat deposition and on inhibiting inflammatory responses in both hepatocytes and macrophages.

Grant Funding Source: Supported by ADA, AHA, NIH
Effects of oat β‐glucan on bile salts absorption across porcine intestinal mucosa using Ussing chamber system (372.4)
Authors: Gunness Purnima , Michiels Joris , De Smet Stefaan , Vanhaecke Lynn , Gidley Mike
Published: June 2021

Soluble dietary fibres (SDFs) such as oat β‐glucan decrease blood triglycerides and cholesterol. The current lead hypothesis is that this is caused by slowing the re‐absorption of bile salts (BS), possibly by SDF causing an increase in the barrier properties of the unstirred water layer lining the epithelium of the small intestine (SI) by adhering and/or penetrating between the microvilli, thus hindering the uptake of BS. Pigs used as a human model were fed on a control diet (n=6) and a diet containing 10% oat βG (n=6) for 27‐29 d. The SI was sectioned into proximal, mid jejunum and terminal ileum. Each section was prepared and mounted in triplicate into 18 Ussing chambers. Glycodeoxycholate (GDC) and fluorescein isothiocyanate‐labelled dextran (FITC‐dextran (4kDa), to check for tissue integrity) with or without oat βG were added to the mucosal side of the chambers and samples for GDC and FITC‐dextran analyses taken from the serosal side, every 20 min for 80 min. Fresh tissue and tissues after diffusion experiment in the Ussing chambers were fixed for microscopic comparison. The preliminary GDC results show that (1) there is a decrease in the amount of GDC diffusing across the epithelium with the βG diet compared to the control diet, (2) ileal passage is different to passage across the jejunum, and (3) added βG to the mucosal side causes a reduction in the absorption of GDC in the terminal ileum of pigs from the control diet and a reduction in both the proximal jejunum and terminal ileum for tissues from the βG diet. The Ussing chamber seems to be a useful system to test hypotheses on how SDF reduces the diffusion of BS across the epithelium of the SI and thereby helps to understand the mechanisms and properties of SDF required for lipid management and consequent reduction in risk for cardiovascular disease.

Grant Funding Source: Supported by ARC Centre of Excellence in Plant Cell Walls
Genistein promotes a gene expression profile characteristic of brown rather than white adipocytes and increases Sirt1 expression in mouse NIH3T3‐L1 cells (372.7)
Authors: Aziz Sadat , Wakeling Luisa , Hesketh John , Ford Dianne
Published: June 2021

Various possible benefits have been attributed to the dietary isoflavone genistein. In common with resveratrol, which may act via sirtuin 1 (Sirt1), these benefits include protection from diet‐induced obesity. We thus aimed to determine if genistein affected adipogenesis and/or Sirt1 expression using a cell culture model.

NIH3T3‐L1 cells were differentiated into adipocytes (from 48 h post‐confluence, taken as day 0) in the presence or absence of genistein. Gene expression was measured by RT‐qPCR.

A low concentration of genistein (10 µM) and/or shorter exposure (days 0‐12) promoted differentiation to white adipocytes, indicated by large fat droplets and increased expression of adipocyte marker genes (Acaca (acetyl Co‐A carboxylase‐α), Fasn (fatty acid synthase), Fabp4 (fatty acid binding protein 4), Lipe (hormone sensitive lipase), Retn (resistin), Rarres2 (chemerin)). However, at higher concentrations of genistein (50‐100 µM) and/or after longer exposure (days 0‐12) cells had smaller fat droplets and lower expression of these genes, coupled with increased expression of Sirt1 and of genes characteristic of brown adipocytes (Ucp1 (uncoupling protein 1) and Cebpb (CCAAT/enhancer binding protein‐β)).

Dietary genistein may thus protect against obesity by encouraging the development of brown, rather than white, adipose tissue, possibly through a mechanism involving Sirt1.

Grant Funding Source: Kurdistan Regional Government
Differential impacts of high fat and high Se diets on tissue lipid profiles of young adult and old wild‐type and GPX1‐/‐ mice (374.5)
Authors: Zhao Zeping , Kim Jonggun , Lei Xin Gen
Published: June 2021

Our previous research has demonstrated hyperinsulinemia and elevated lipogenesis by feeding pigs and rats with Se at 3.0 mg/kg of diet. This study was to determine the impacts of a moderately high Se (1.0 vs. 0.3 mg/kg as selenite) and(or) high fat (60 vs. 16% energy from fat) on lipid profiles in plasma, adipose and liver tissues of young adult (2‐4 mo of age) and old (6‐10 mo of age) wild‐type (WT) and GPX1‐/‐ (KO) male mice. A total of 80 mice were divided into 4 parallel (genotype by age) experiments (n = 5/group) and fed one of 4 diets for 6 wk. Body weight was elevated (P < 0.05) by the high fat diet in old WT and young KO mice, but decreased by high Se diet (P < 0.05) in young WT mice. Both high fat and Se intakes enhanced (P < 0.05) plasma glucose concentrations in old WT mice. High Se intake decreased plasma non‐esterified fatty acids (NEFA) concentrations in young WT mice. There was little effect of high fat or Se intake on plasma lipid profiles of KO mice. Adipose tissue concentrations of triglycerides, cholesterol, and NEFA were consistently elevated by high fat and Se in both young WT and KO mice. In comparison, such effects of the dietary treatments on adipose tissue of old WT and KO mice or on liver of all 4 groups of mice were less obvious or consistent. In conclusion, our results revealed a uniquely high response of adipose tissue lipid profile to dietary intakes of high fat and Se and a strong interaction of age by GPX1 knockout on the response (NIH DK 53018).

Grant Funding Source: (NIH DK 53018).
Human milk oligosaccharides protect bladder epithelial cells against uropathogenic E. coli and Streptococcus agalactiae infections (38.5)
Authors: Lin Ann , Autran Chloe , Espanola Sophia , Lewis Amanda , Bode Lars , Nizet Victor
Published: June 2021

Urinary tract infection (UTI) is primarily caused by uropathogenic E. coli (UPEC) and sometimes Streptococcus agalactiae (GBS). Recurrent infection that can progress to life‐threatening renal failure has remained as a serious global health concern in infants. Human milk oligosaccharides (HMOs) have been detected in urine of breast‐fed, but not formula‐fed neonates. We investigated the antimicrobial properties and mechanisms HMOs deploy to elicit protection in human bladder epithelial cells. We found HMO‐pretreated epithelial cells were significantly more resistant to invasion by UPEC CFT073, a prototypic strain causing urosepsis. However, HMO pre‐treatment had no significant effect in interfering with UPEC adhesion. Conversely, HMO pre‐treated cells suffer significantly less GBS COH‐1 adhesion and invasion. This result was recapitulated in vivo, in which significantly less GBS was recovered from the bladder of mice treated with HMOs. While HMOs do not play a role in maintaining host cell viability during GBS infection, we found HMOs treatment rapidly UPEC‐mediated host cell cytotoxicity. Moreover, the sialic acid‐containing fraction of HMOs reduced UPEC‐mediated MAPK and NF‐κB activation. Collectively, we showed that HMOs protect the urinary tract from microbial infection, and may be a contributing mechanism underlying the epidemiological evidence of reduced UTI incidence in breast‐fed infants.

Grant Funding Source: Canadian Institutes of Health Research (CIHR)
The effect of BMI on the immunoglobulin subclass response to influenza vaccination (382.1)
Authors: Neidich Scott , Milner J , Xiao Ping‐jie , Patel Nikita , Mensah‐Biney Kevin , Hudgens Michael , Beck Melinda
Published: June 2021

Vaccination with influenza vaccine is the best method to prevent or lessen infection with influenza virus. While obesity is an independent risk factor for developing severe influenza infection, the efficacy of influenza vaccine in obese humans is an emerging research area. We have previously demonstrated that serum titers of influenza vaccine specific IgG has a steeper decline one year post vaccination in an obese population compared with healthy weight individuals. To determine if subclasses of immunogloblulin (Ig) IgG or total IgM were also impaired in an obese population post influenza vaccination, we assessed the immunoglobulin response to influenza vaccination in adults. Patients visiting the UNC Family Practice Health Center to receive the 2012‐2013 seasonal trivalent influenza vaccine (TIV) were invited to participate in this study. A blood sample was drawn prior to receiving the vaccine, as well as thirty days post vaccination. Height and weight measurements were used to calculate BMI. Using an ELISA, pre and post vaccination serum samples were analyzed for TIV‐specific IgM, IgG1, IgG2, IgG3, IgG4, as well as total IgG. We report here that obesity was associated with a lower IgG1 response post vaccination in 18‐35 year old participants compared with healthy weight and overweight individuals. Participants above the age of 61 had decreased levels of IgM and IgG3, compared to younger participants, regardless of weight status. These data suggest that immunoglobulin subclasses are independently affected by weight status and age and may play a role in the increased susceptibility to severe influenza infection found in obese individuals.

Grant Funding Source: Supported by the National Institutes of Health
n‐3 Polyunsaturated fatty acids reduce Th17 polarization by decreasing responsiveness to interleukin‐6 (382.3)
Authors: Allen M. Jeannie , Fan Yang‐Yi , Monk Jennifer , Hou Tim , Barhoumi Rola , McMurray David , Chapkin Robert
Published: June 2021

CD4+ effector T cell subsets (e.g., Th1, Th17) are implicated in autoimmune and inflammatory disorders such as multiple sclerosis, psoriasis and rheumatoid arthritis. We have demonstrated that n‐3 polyunsaturated fatty acids (PUFA), when supplied in the diet or in fat‐1 transgenic mice which generate n‐3 PUFA de novo, suppress CD4+ T cell activation and differentiation into pathogenic Th17 cells. We hypothesized that n‐3 PUFA alter the response of CD4+ T cells to IL‐6 in a lipid raft membrane‐dependent fashion. IL‐6 induces Th17 polarization and signals through the membrane‐bound signal transducer, gp130. Upon activation, naïve splenic CD4+ T cells from fat‐1 mice exhibited significantly lower surface expression of the IL‐6 Receptor (IL‐6R). However, the release of soluble IL‐6R was unaffected by treatment. We observed a significant decrease in the association of gp130 with lipid rafts in activated fat‐1 CD4+ T cells and a 35% reduction in gp130 homodimerization, an obligate requirement for downstream signaling. The phosphorylation of STAT3, a downstream target of IL‐6‐dependent signaling, was also decreased in response to exogenous IL‐6 in fat‐1 CD4+ T cells. Our results suggest that n‐3 PUFA suppress Th17 cell differentiation, in part, by reducing membrane raft‐dependent responsiveness to IL‐6, an essential polarizing cytokine.

Grant Funding Source: Supported by the NIH and USDA‐Vegetable Crop Improvement Center
Adipose transcriptomics reveals novel genes and lincRNAs modified by n‐3 PUFA supplementation and human‐evoked endotoxemia (383.1)
Authors: Ferguson Jane , Xue Chenyi , Ballantyne Rachel , Gosai Sager , Li Mingyao , Reilly Muredach
Published: June 2021

Long‐chain omega‐3 polyunsaturated fatty acids (n‐3 PUFA) may be protective in cardiometabolic disease through modulation of chronic low‐grade systemic and adipose inflammation. However the effect of n‐3 PUFA supplementation on resting biomarkers is subtle; intervention studies often lack power to detect significant effects. The objective of the present study was to use unbiased adipose transcriptomics and evoked endotoxemia in human as a powerful model for genomic discovery in n‐3 PUFA supplementation and inflammation. We collected adipose tissue biopsies from healthy individuals before and after n‐3 PUFA supplementation (3600mg/day EPA/DHA) for 6‐8 weeks compared with placebo (N=8 per group), and following an inflammatory challenge (LPS 0.6 ng/kg).Using unbiased transcriptomics (RNASeq) we profiled adipose tissue gene expression before and after n‐3 PUFA supplementation, and after LPS challenge. We discovered a number of genes and lincRNAs that were significantly regulated by n‐3 PUFA supplementation, including down‐regulation of inflammatory genes (IL1RN, IFI30, PLA2G7), lipid‐related genes (ELOVL6, NCEH1) and novel lincRNA (linc‐ARF6‐1). Further, the transcriptomic response to LPS differed between the n‐3 PUFA and the placebo group. We found increased up‐regulation of S100A8 and S100A9 in n‐3 PUFA compared with placebo; these pro‐inflammatory and inflammasome‐activating genes protect against pathogens through formation of their heterodimer, calprotectin. Thus, a novel mechanism of n‐3 PUFA protective effects in vivo may be through increased expression of S100A8 and S100A9 in response to innate immune activation. Unbiased transcriptomics is a powerful genomic discovery tool in the context of nutritional intervention and evoked inflammatory phenotypes.

Grant Funding Source: Supported by NIH R01‐HL‐113147, UL1RR024134, P20‐DK 019525, P50‐HL‐083799
Population nutrition research at the frontiers: an examination of recent literature (384.1)
Authors: Pelletier David , Pham Judy
Published: June 2021

The profound health, social and economic consequences of nutrition problems, and their multisectoral causes and solutions, creates a need for broadened research agendas at multiple scales to complement research on the biology and behavior of individuals that has been the foundation of nutritional sciences. A recent paper identified several dimensions for the frontiers of population nutrition research and suggested that research is already moving in these directions. These dimensions relate to why, what, who and how we study and the disciplinary foundations for this research. This paper reports on a systematic examination of recent literature to quantify research in relation to these dimensions. We examined 968 papers published in 2012 from 6 nutrition journals, 4 public health journals and 3 food policy journals. Each paper was coded on the presence or absence of Mode 2 (frontier) characteristics as defined in previous work. Mode 2 characteristics were identified in 7% of the 762 papers from the nutrition journals, 36% of the 77 food/nutrition papers in the public health journals and 100% of the 129 food/nutrition papers in the food policy journals. Of the Mode 2 papers in nutrition and public health journals, 70‐80% had a focus on broad topics such as national policy, workforce development, programs, schools and global issues and 30‐40% met each of the other Mode 2 criteria such as the actor focus (other than consumer), non‐traditional methods and engaged or participatory approaches. These data indicate that Mode 2 food/nutrition research is fairly common in public health and food policy journals but is a relatively small proportion of papers in nutrition journals. The increasing societal attention to nutrition creates opportunities for greatly expanding Mode 2 population nutrition research.
Behavioural measures of nutrition related cognitive development in rural Gambia: studies from birth to 24 months of age (389.1)
Authors: Lloyd‐Fox Sarah , Halliday Drew , Maris Helen , Begus Katarina , Darboe Momodou , Prentice Andrew , Moore Sophie , Elwell Clare
Published: June 2021

The Mullen Scales of Early Learning is a developmental assessment battery which can be administered from birth to five years of age to separately assess gross motor, fine motor, receptive language, expressive language, and visual receptive abilities. Scores for each subscale as well as an overall composite score are typically computed based on a comparison to Western norms. The aim of this work was to adapt the Mullen Scales for use at a field station in rural Africa as an assessment tool for cognitive function in nutrition based studies. We also examine associations between behavioural performance and anthropometric growth indices in young infants.

A committee of native, dual‐language speakers and trained Mullen administrators reviewed and adapted the Mullen assessment for use in The Gambia. Adaptations included the linguistic translation of the item‐by‐item verbal prompts and the substitution of culturally inappropriate stimuli.

We studied infants longitudinally at two time points between the age of 9‐17 months, and a separate group of toddlers at 18‐24 months of age. In addition to behavioural assessment, we collected anthropometric measurements and generated z‐scores based on WHO standards. An analysis of the relationship between growth and cognitive development revealed several significant associations over the first two years of life; in particular there were significant correlations with the language subscales. These results suggest that early language development is associated with growth markers in Gambian infants. The trajectories of several growth measures appear to decline steadily across the first 2 years of life, with associations to impaired behavioural performance already apparent from around the first year. These associations are difficult to examine in earlier infancy as the efficacy of behavioural measures at this age is limited. Optical imaging may be a viable solution to this problem, by providing an objective measure of cognitive function from birth.

Grant Funding Source: Bill and Melinda Gates Foundation
Multiple micronutrient powders reduce stunting and anemia and improve language development among full‐term low birth weight children in Bangladesh (389.3)
Authors: Shafique Sohana , Singla Daisy , Aboud Frances , Jolly Saira , Zlotkin Stanley
Published: June 2021

Objective: Explore efficacy of 22‐element micronutrient powders (MNP) plus nutrition, health and hygiene education (NHHE) to reduce stunting and anemia, and improve mental development among low birth weight (LBW) infants. Methods: Prospective community‐based cluster‐randomized trial, conducted among 244 full‐term LBW infants from 6‐12 months (mo) in rural Bangladesh. A total of 24 clusters were randomly assigned to two groups: i) NHHE plus MNP (to be provided with available complementary food); ii) NHHE only. Capillary blood was collected at 6 and 12mo using HemoCue. At ~18mo cognitive and language scores of children were assessed using Bayley Scales of Infant and Toddler Development III (n=186). Results: At 12 mo, compared to ‘NHHE only’, infants in ‘NHHE+MNP’ had significantly lower proportion of stunting (55.9% vs 33.6%, p<0.001) and anemia (23.9% vs 11.7%, p<0.001). Mean Hb concentration in the ‘NHHE+MNP’infants increased from 93.8±10.8 g/L at 6mo to 109.8±12.3 g/L at 12mo (p<0.05), whereas no such difference was found in ‘NHHE only’ group. Expressive language scores were significantly higher among ‘NHHE+MNP’ compared with ‘NHHE only’ (p<0.01; d=0.45). There were no differences between groups on cognitive or receptive language scores. Conclusion: Use of broad range micronutrient powders effectively reduce stunting and anemia and improve expressive language among term LBW children.

Grant Funding Source: Bill & Melinda Gates Foundation to FHI 360, through the Alive & Thrive Small Grants Program managed
Lycopene and its metabolite apo‐10’‐lycopenoic acid suppressed high‐fat diet‐induced hepatic steatosis in beta‐carotene‐9’,10’‐oxygenase knockout mice (39.3)
Authors: IP Blanche , Liu Chun , Smith Donald , von Lintig Johannes , Wang Xiang‐Dong
Published: June 2021

Prevalence of non‐alcoholic fatty liver disease is associated with the current obesity epidemic. Lycopene (LYC), which can generate apo‐10’‐lycopenoic acid (APO10LA) endogenously by beta‐carotene‐9’,10’‐oxygenase (BCO2), has been shown to modulate adipose and hepatic lipid metabolism. We examined whether BCO2 is essential for LYC’s biological effects. 12‐week supplementation of either LYC (100 mg/kg diet) or APO10LA (10 mg/kg diet) inhibited high‐fat diet (HFD)‐induced hepatic steatosis (by 77% vs 63% respectively) in BCO2‐knockout (BCO2‐KO) mice. APO10LA‐mediated steatosis suppression was associated with up‐regulated hepatic sirtuin 1 protein expression, and reduced de novo lipogenic markers (Scd1 gene; AMPK, ACC phosphorylation). These APO10LA‐mediated effects were absent in the LYC group. Intriguingly, LYC induced gene expression involved in fatty acid (FA) uptake (Lpl, Fatp4), FA β‐oxidation (Pparα, Lcad), and mitochondrial uncoupling (Ucp3) in mesenteric adipose tissue (MAT), and these LYC‐mediated effects were not present in APO10LA‐fed mice. Importantly, MAT Lpl and Ucp3 expressions were negatively correlated with hepatic steatosis, suggesting that LYC may reduce FA delivery from MAT to the liver. Taken together, this data provided novel insights that LYC and APO10LA may inhibit HFD‐induced steatosis in BCO2‐KO mice through differential mechanisms.

Grant Funding Source: USDA/ARS grant 1950‐51000‐074S
Using verbal protocol to examine the comprehension and use of nutrition facts tables among young Canadians (390.8)
Authors: Shen‐Tu Grace , Hobin Erin , Sheeshka Judy , O'Brien Mary , McVey Gail , Hammond David
Published: June 2021

OBJECTIVES: To explore how young Canadians engage with, understand, and use serving size and %DV information on current and modified Nutrition Facts Tables (NFts).

METHODS: 26 participants aged 16‐24 years were recruited. Participants were randomly assigned to two NFts, one with high (蠅15%DV) and one with low (≤5%DV) sodium amount, altered to one of the 6 conditions: 1) Current NFts; 2) Standardized serving sizes (SSS); 3) High/Low (H/L) descriptors beside % Daily Value (%DV) for negative nutrients; 4) SSS + H/L descriptors; 5) H/L and color beside %DV; and 6) SSS + H/L and color. Participants completed a skill‐based questionnaire using the “think aloud” technique. Content analysis was used to examine how participants interpret, define, compare, and manipulate information in NFts.

RESULTS: Exploration of participants’ thought processes identified barriers to understanding and using the current NFt. The barriers include failure to understand %DV, difficulty in manipulating %DV to compare nutrients across various serving sizes, and confusion about how to use NFt to choose foods. Analysis also revealed that the barriers mentioned above can be addressed by standardizing serving sizes on NFts and adding simple descriptors and/or colors to %DV information.

CONCLUSIONS: SSS and H/L descriptors or color coded %DV information assists young people in understanding and using NFts when comparing and choosing foods.
Children’s intake of candy while in the absence of hunger exceeds USDA SoFAS limits (47.4)
Authors: Rollins Brandi , Savage Jennifer , Birch Leann
Published: June 2021

Children’s intake of candy has increased over the past three decades, and is a source of added sugars and empty calories in middle childhood. However, little is known about the factors that influence children’s intake of candy. We examined children’s (ages 5‐8) intake of candy while in the absence of hunger in a laboratory setting, and evaluated individual differences in children’s candy intake. Children (n=66) were provided with a standard lunch consisting of a sandwich, milk, and apple slices; following lunch, each child self‐reported on their hunger level, and if not hungry, they were provided with free access to11 types of candy (e.g. solid chocolate bars, lollipops). Children’s height/weight were measured. On average, children consumed 198 kcals (SD = 118.8; range 0 to 464) of candy following a standard lunch, amounting to ~15.2% of the USDA estimated calorie needs for the average sedentary 4‐8 year old. Children’s energy intake from chocolate candies (M=102.3, SD=101.1; range 0 to 385) and non‐chocolate candies (M=96.7, SD=72.9; range 0 to 332) did not differ. In addition, no differences were observed by child gender, age, or BMI. Overall, our results indicate that children’s intake of candy in a free access condition and while in the absence of hunger exceeds the maximum limit (8‐9%) suggested by the USDA for calories from solid fats and added sugars (SoFAS).

Grant Funding Source: Supported by the National Confectioners' Association
Spatially‐resolved proteomic mapping of living cells via peroxidase‐mediated promiscuous biotinylation (473.2)
Authors: Ting Alice
Published: June 2021

Microscopy and mass spectrometry (MS)‐based proteomics are complementary techniques: the former provides spatiotemporal information in living cells, but only for a handful of recombinant proteins at a time, while the latter can detect thousands of endogenous proteins simultaneously, but only in lysed samples. In this talk, I will describe a new technology that combines the strengths of microscopy and MS by generating spatially and temporally‐resolved proteomic maps of endogenous proteins within living cells. The method relies on a genetically targetable peroxidase enzyme that biotinylates nearby proteins, which are subsequently identified by MS. We used this approach to identify 495 proteins within the human mitochondrial matrix and 145 proteins within the mitochondrial intermembrane space (IMS), including 50 proteins that have never before been assigned to mitochondria. The labeling was exceptionally specific, able to distinguish between inner membrane proteins facing the matrix versus the IMS. Our catalog also revised the sub‐mitochondrial localizations for several well‐studied proteins, with the new assignments confirmed by electron microscopy.
Mechanical force transmission at single integrin complexes in living cells (479.1)
Authors: Dunn Alexander , Mekhdjian Armen , Morimatsu Masatoshi , Adhikari Arjun
Published: June 2021

Mechanical interactions between cells and the extracellular matrix (ECM) play central roles in directing cell migration, proliferation, and stem‐cell differentiation. However, fundamental aspects of how cells detect and generate mechanical forces at the cell‐ECM interface remain poorly understood. Here we describe the use of molecular tension sensors to visualize the forces experienced by single cellular adhesion molecules with nanometer, piconewton, and second resolutions. The molecular tension sensors consist of a Förster resonant energy transfer (FRET) donor and acceptor pair separated by a protein domain that acts as an extensible spring. Sensor molecules are immobilized to an avidin‐coated glass coverslip at one end and present an integrin‐binding site at the other. Cellular integrins transmit force to the FRET pairs, resulting in decreased FRET with increasing load. We find that human foreskin fibroblasts (HFFs) adhere to sensor‐functionalized surfaces and develop focal adhesions as evidenced by paxillin localization and actin stress fiber formation. We observe a bimodal distribution of FRET efficiency values for sensor molecules beneath HFFs, with one peak corresponding to zero load and the other indicating a distribution of forces between 1 and 4 pN. The relatively narrow range of forces that we observe suggests that mechanical tension at individual adhesion complexes is subject to active feedback and control. Ongoing work makes use of molecular‐scale force measurements to elucidate the mechanically activated signaling events that underlie cell migration and adhesion.
Twist1 induces dissemination by activating an epithelial motility program that requires E‐cadherin (479.2)
Authors: Shamir Eliah , Pappalardo Elisa , Tran Phuoc , Bader Joel , Ewald Andrew
Published: June 2021

Cancer metastasis begins with dissemination of cells from an epithelial tumor. Each tumor contains many mutations and a heterogeneous cell population. As such, it has been difficult to isolate the molecular requirements for a single epithelial cell to disseminate. One posited mechanism for dissemination is activation of an epithelial to mesenchymal transition (EMT), in which repression of the cell adhesion gene E‐cadherin is considered the driving molecular event. We sought to test the sufficiency of single gene perturbations to induce dissemination in primary murine mammary epithelium. Deletion of E‐cadherin disrupted simple architecture and branching morphogenesis but rarely resulted in dissemination. In contrast, expression of the EMT transcription factor Twist1 induced rapid dissemination of cells into the extracellular matrix. Twist1 induced acute transcriptional changes in cell‐matrix adhesion genes but not in epithelial‐specific genes, including E‐cadherin. Surprisingly, knockdown of E‐cadherin inhibited Twist1‐induced single cell dissemination and promoted collective epithelial migration. We conclude that Twist1 activates an epithelial motility program without requiring a transition to mesenchymal cell fate. To date, it remains unclear why some Twist1+ cells disseminate while many remain in the epithelium. We next seek to test the sufficiency of Twist1 to induce dissemination in distinct mammary epithelial subpopulations. We anticipate that cell type‐specific differences may suggest which cells within a heterogeneous tumor have the highest metastatic potential.
Modularity in nuclear mechanotransduction and genome regulation (479.3)
Authors: Shivashankar G.V.
Published: June 2021

Mechanical signals from the extracellular matrix impinge on cellular geometry resulting in altered functional nuclear landscape and gene expression programs. These alterations regulate diverse biological processes including stem‐cell differentiation, developmental genetic programs and cellular homeostasis. How such signals are integrated to the 3D spatio‐temporal organization of the cell nucleus to elicit differential gene expression patterns are poorly understood. To investigate the biophysical principles underlying these processes, we use a multi‐disciplinary approach, combining high resolution imaging of live‐cells cultured on micro‐patterned substrates, single‐cell mechanics and genomics. I will describe some of our ongoing work that is beginning to provide quantitative and modular links between cell geometry and nuclear mechanics in regulating 3D chromosome organization and genetic information.
Targeting of Lewis‐X‐containing glycans blocks PMN transepithelial migration and increases phagocytosis and degranulation (488.3)
Authors: Brazil Jennifer , Sumagin Ronen , Lee Goo , Forrest Osric , Cummings Richard , Parkos Charles , Louis Nancy , Louis Nancy
Published: June 2021

The transepithelial migration (TEM) of neutrophils (PMN) is a histopathological hallmark of inflammatory bowel disease (IBD), yet the mechanisms controlling PMN TEM remain poorly defined. The fucosylated, terminal glycan determinant Lewis X (Lex), expressed on the glycans of PMN surface glycoproteins (including MAC‐1 and LFA‐1), has previously been implicated in adhesive interactions between PMN and endothelium. However, little is known about the role of Lex in PMN function following extravasation. Flow cytometry analyses revealed increased surface expression of Lex on human PMN following TEM, while immunohistochemistry demonstrated robust expression of PMN‐associated Lex within crypt abscesses in the colonic epithelium of individuals with IBD. Furthermore, engagement of Lex increased PMN adhesive interactions, both with other PMNs and with intestinal epithelial cells, blocking PMN chemotaxis and TEM. In addition to blocking PMN trafficking, targeting of Lex also altered post‐migratory PMN functions, increasing both PMN phagocytosis of Salmonella enterica and release of primary granules. Therefore, glycans expressing the Lex determinant represent a novel target for regulating both the trafficking of PMN into the intestinal lumen and PMN function. Further, given its robust expression in migrating PMN and during inflammation, Lex may be a rational target for modulating inflammation in IBD.

Grant Funding Source: Supported by Crohn's & Colitis Foundation of America and National Institutes of Health
Annexin A1 released from epithelial extracellular vesicles and synthetic nanoparticles promotes wound repair (488.5)
Authors: Quiros Miguel , Leoni Giovanna , Kamaly Nazila , Neumann Philipp , Nishio Hikaru , Fredman Gabrielle , Alam Mohammad , Kusters Dennis , Reutelingsperger Chris , Perretti Mauro , Parkos Charles , Farokhzad Omid , Neish Andrew , Nusrat Asma
Published: June 2021

Repair of epithelial wounds is essential for establishing intestinal mucosal homeostasis. Annexin 1 (AnxA1) promotes wound closure by activating intestinal epithelial formyl peptide receptor signaling. Here we show that AnxA1 is released from intestinal epithelial cells in extracellular vesicles (EVs). We determined that AnxA1 EV release is regulated by actin cytoskeletal dynamics and Rho GTPase signaling. EVs isolated from supernatants of epithelial cells increased reactive oxygen species generation and wound healing. Interestingly, EVs from AnxA1 null mice failed to enhance wound repair, demonstrating an important role of AnxA1 EVs in wound healing. Localized intramucosal administration of synthetic nanoparticles containing AnxA1 mimetic peptide Ac2‐26 similarly promoted colonic mucosal wound repair. Epithelial derived AnxA1 EVs represent a novel mechanism regulating wound repair and local administration of synthetic vesicles containing pro‐resolving peptides offer new therapeutic approaches to promote healing of intestinal mucosal ulcers
Enteric commensal bacteria activate formyl peptide receptor 1 to regulate intestinal epithelial homeostasis and wound repair (488.7)
Authors: Alam Ashfaqul , Leoni Giovanna , Jones Rheinallt , Nusrat Asma , Neish Andrew
Published: June 2021

Mucosal homeostasis and wound repair require epithelial proliferation and migration. Gut commensal microbiota are essential for normal intestinal development, renewal and repair. N‐formyl peptide receptors (FPRs) are G protein coupled receptors that function as pattern recognition receptors. FPR ligands include an array of peptides, lipids and small molecules derived from bacteria and the host. Intestinal epithelial cells (IECs) express functional FPRs in the cell surface plasma membrane. Recently we demonstrated that Annexin A1 and specific gut microbiota stimulate epithelial FPRs to generate reactive oxygen species which modulate cell signaling pathways critical for IEC proliferation and migration. However, it is incompletely understood how FPR1 maintains homeostasis of the gut symbionts important for mucosal wound healing. Here, we studied composition of murine mucosa‐associated microbiota in intact epithelia and endoscopic wound beds by pyrosequencing. We identified that specific species of essential gut bacteria is associated with mucosal wound bed. We also observed that FPR1 maintains homeostasis of mucosa‐associated microbiota characterized by their enrichment, composition, and spatial localization with respect to IECs. These changes are also associated with alterations in the colonic firm mucin layer, increased epithelial permeability and defective mucosal wound healing in FPR1‐/‐ mice during chronic DSS‐induced colitis. In conclusion, our study highlights a role of FPR1 in mediating important host‐microbiota interactions controlling gut mucosal homeostasis and wound repair.

Grant Funding Source: CCFA and NIH
Model students in foundation science courses improves retention and performance in undergraduate STEM programs (531.21)
Authors: Keen‐Rhinehart Erin , Bolt‐Michewicz Jilliane , Black James
Published: June 2021

The college years are a time of intense attrition from science, technology, engineering and mathematics (STEM) fields, negatively impacting the nation’s scientific capacity and economic competitiveness. Attrition is especially prominent between the first and second years of college for STEM students. Many students coming out of high school are ill prepared to perform the critical thinking and rigorous academic work required in STEM fields, and the initial gateway courses in these fields tend to favor a “weed out” philosophy, providing a less than hospitable environment in which to begin a college career. In an effort to ameliorate these two factors, we developed a supplemental peer instruction program (the Model Student Program) as a collaborative effort between the Biology Department and the Center for Academic Achievement (CAA) that allows proficient peers to help first year students digest complex material and to model the behaviors required for success in STEM at the college level. We hypothesized that this program would improve retention and performance of in the initial gateway courses required for the Biology major. Data from three consecutive years of implementing this program provides evidence of reduced attrition from the university by 50%, and improved average course grades. In addition, the students report numerous academic and social benefits from their interactions with the model student, and the model students report that they value the close working relationship with the course instructor and a better understanding of the course content. Due to the demonstrated success of the program, it is now standard practice in all foundational natural science courses, including Physics, General Chemistry and Organic Chemistry. Therefore, this program appears to be successful at helping students navigate the gateway courses required for persistence as STEM students.