bluuebunny/crossref_metadata_2025 huggingface dataset:
Liver Specific Ablation of Integrin Linked Kinase in Mice Results in Enhanced and Prolonged cell proliferation After Phenobarbital Administration
Authors: Donthamsetty Shashikiran , Vishakha Bhave , Bell Aaron , Mars Wendy , Yang Yu , Orr Anne , Bowen William , Michalopoulos George
Published: June 2021

This study investigates the role of ILK in hepatocyte proliferation induced by Phenobarbital (PB). WT (wild type) and ILK‐/‐ mice were given PB( 0.1% in drinking water) for 10 days. Livers were harvested on 2, 5 and 10 day during PB administration. In the ILK‐/‐ mice the liver/body weight ratio was more than double as compared to 0h at day 2 and 5 while at day 10 it was thrice. In the WT mice the increase was not dramatic and seems to have leveled off after day 2. There were slightly increased PCNA positive cells in the ILK‐/‐ animals at day 2 as compared to WT after PB administration. In the WT animals the proliferative response had come back to normal by day 5 and 10 but the ILK‐/‐ mice still had PCNA positive cells at day 5 and 10 suggesting a prolonged proliferative response. ILK‐/‐ mice also showed increased expression of key genes involved in hepatocyte proliferation at different time points during PB administration. In summarize, ECM proteins communicate with the signaling machinery of dividing cells via ILK to regulate hepatocyte proliferation and termination of the proliferative response. Lack of ILK in the hepatocytes have prolonged proliferative response to a mitogenic stimuli suggesting defect termination of proliferative response.

The work is supported by a R01 grant (5R01CA035373‐26) titled "HGF in Liver Development, Regeneration and Neoplasia"
An Fgf/Gremlin Inhibitory Feedback Loop Triggers Termination of Limb Bud Outgrowth
Authors: Sun Xin , Verheyden Jamie M.
Published: June 2021

During organ formation and regeneration a proper balance between promoting and restricting growth is critical to achieve stereotypical size. Limb bud outgrowth is driven by signals in a positive feedback loop involving fibroblast growth factor (Fgf) genes, sonic hedgehog (Shh) and Gremlin1 (Grem1). Precise termination of these signals is essential to restrict limb bud size. The current model predicts a sequence of signal termination consistent with that in chick limb buds. Our finding that the sequence in mouse limb buds is different led us to explore alternative mechanisms. By analyzing compound mouse mutants defective in genes comprising the positive loop, we uncovered genetic evidence that FGF signaling can repress Grem1 expression, revealing a novel Fgf/Grem1 inhibitory loop. This repression occurs in both mouse and chick limb buds, and is dependent on high FGF activity. These data support a mechanism where the positive Fgf/Shh loop drives outgrowth and an increase in FGF signaling, which triggers the Fgf/Grem1 inhibitory loop. The inhibitory loop then operates to terminate outgrowth signals in the order observed in either mouse or chick limb buds. Our study unveils the concept of a self‐promoting and self‐terminating circuit that may be used to attain proper tissue size in a broad spectrum of developmental and regenerative settings.
Bioengineering Strategies to Control Neural Stem/Progenitor Cell Differentiation
Authors: Shoichet Molly S , Zahir Tasneem , Kim Howard , Morshead Cindi M , Tator Charles H
Published: June 2021

Traumatic spinal cord injury is devastating, leading to lifelong paralysis with little hope of recovery based on current treatments. Neural stem/progenitor cells (NSPCs) offer the potential to promote regeneration after injury, providing a permissive environment to host cells. We have been particularly interested in sub‐acute injury models where both NSPC survival and regenerative potential are greatest. In our preliminary studies, we compared stem cells derived from the brain vs. those from the spinal cord in a transection injury model, where the stem cells were delivered in biocompatible hydrogel tubes of chitosan. Here we observed greater brain‐derived cell numbers and larger tissue bridges than spinal cord‐derived cells. In on‐going studies, we have refined our tube design to include microspheres for sustained, localized release of relevant factors. We have screened a number of factors in vitro to yield an enriched population of one cell type, either neuronal or glial. These factors are being explored for incorporation into the tubes and their impact measured on stem cell survival and differentiation in vitro and in an in vivo rat transection injury model.
From Molecules to Men – Molecular Cytogenetics in the 21st Century
Authors: Weier H.‐Ulli G
Published: June 2021

Medical Genetics and the Clinical Diagnosis of inborn or acquired genetic diseases have been influenced dramatically by the introduction of Molecular Cytogenetics. The last two decades have witnessed a dramatic shift from conventional karyotype analysis based on chromosome banding techniques to molecular, DNA sequence‐based methods for the detection of abnormalities underlying human genetic diseases. Recognizing the importance of proper characterization of chromosomal abnormalities in many fields including in vitro fertilization, early human development and placental biology, perinatal diagnosis, cancer research or accidental/environmental mutagenesis, basic as well as translational researchers, physicians, care givers and patient advocates have relied increasingly on information provided by molecular cytogenetic analyses. Highly successful translational research endeavors and academic‐commercial interactions utilizing, among others, the tools developed in the International Human Genome Project have brought these developments into the reach of the average clinical laboratory.
The Colour of Your Inside: Anatomical Body Painting
Authors: Finn Gabrielle Maria
Published: June 2021

Medical students still primarily learn anatomy from studying preserved human cadavers. These are monochrome due to the preservation process, unlike the inside of the living body.

In an effort to overcome some of the surprise at dealing with 'living colour' and introduce living anatomy, we have adopted a number of approaches. These include projection of images on the surface of the living body, using medical students as the 'canvas', and body painting of detailed renditions of anatomical features on the skin. These serve a number of purposes, most importantly it helps students to achieve greater anatomical knowledge, specifically of surface anatomy. It is often the bold use of colour that aids students recall the anatomy projected. Students' learning transfers from surface to deep through the act of being the painter (doing) and the painted (reading instructions and observing).

Students engage in concurrent peer‐physical examination. Students develop an understanding of what it feels like to undress and be examined, developing greater body awareness, potentially developing more empathetic physicians.

Students enjoy painting as an adjunct to didactic lectures.

Research internally supported.

Grant Funding Source

Durham University
Myocardial Infarction: How times have changed.
Authors: Addley David J.
Published: June 2021

Chest pain is the number one presenting complaint in Emergency Departments throughout the country. Over 1 Million patients are hospitalized for Acute Coronary Syndrome per year. Cardiovascular disease is the leading cause of death in the United States. We will review the current guidelines in the diagnosis and treatment of Acute Coronary Syndrome and briefly demonstrate how current tools of its diagnosis and treatment have changed from the past; from ECGs to CKs, from Troponins to BNP, from bare metal stents to drug eluding stents.
Preventing HIV in Developing Countries: Status of Biomedical Interventions
Authors: Vermund Sten H
Published: June 2021

Insights have emerged as to ongoing HIV prevention challenges.

Vaccines

The "STEP" study of a multivalent adenovirus‐vectored prime with a DNA boost did not prevent HIV; in fact, persons with prior adenovirus (+) status were infected with HIV more often than were adenovirus (‐) persons.

Microbicides

Both cellulose sulfate and Carraguard failed to prevent HIV.

Barriers

The female diaphragm was not successful in preventing HIV in Zimbabwe.

Behavior change

A meta‐analysis (Cochrane review) suggested no efficacy of abstinence‐only based behavior change (BMJ 2007).

Risk reduction for injection drug use

HIV seroincidence has declined substantially where needle exchange programs and drug addiction treatment are available.

Male circumcision

Randomized clinical trials in South Africa, Kenya, and Uganda indicated ≈50% reduction in seroincidence among circumcised men.

Control of sexually transmitted infections

The suppression of HSV‐2 with chronic acyclovir did not reduce HIV seroconversions.

Prevention of mother to child transmission

Use of 2‐3 drugs in pregnant women and use of post‐partum prophylaxis in breastfeeding infants can reduce HIV drug resistance and also can increase efficacy (PEPI study). Early therapy of HIV(+) infants is more effective than later therapy (CHER study).

Work in progress

We will highlight recent findings in the HIV Prevention Trials Network.
Roles for Rab6, Arl1 and a novel Rho protein in GCC185‐mediated vesicle tethering at the trans Golgi network
Authors: Pfeffer Suzanne R.
Published: June 2021

GCC185 is a GRIP‐domain containing Golgin that is localized to the trans Golgi network and is required for recycling of mannose 6‐phosphate receptors (MPRs) from endosomes to the Golgi (1). MPRs are present in peripheral, Rab9‐containing vesicles in cells depleted of GCC185; lysosomal hydrolases are also mis‐sorted under these conditions due to the failure of MPRs to recycle (1). GCC185 requires both Rab6 and Arl1 binding to its C‐terminus to achieve Golgi localization; Arl1 binding is enhanced by the presence of Rab6 GTPase (2). A model of the three dimensional structure of the C‐terminus of GCC185 bound to both Rab6 and Arl1 revealed an unexpected, two layer organization of the independent Arl1 and Rab6 GTPase binding sites, and highlighted the potential length with which Rab GTPases extend away from the Golgi surface (105Å; ref. 2). We report here that GCC185 binds multiple, Golgi‐associated Rab GTPases across its entire length, and the Syntaxin 16 t‐SNARE can also bind GCC185's C‐terminus at a site shared with Rab6 (3). A Rab9 binding site near the middle of GCC185 provides a new model for how Rab9‐bearing vesicles may engage this protein to achieve vesicle tethering. Moreover, we have discovered a novel Rho protein that is also required for late steps in MPR recycling to the Golgi complex. This TGN‐localized protein is another Rab9 effector and shows association with GCC185. Thus, vesicle tethering at the TGN involves an unexpectedly large number of nucleotide‐regulated processes and cooperation between a complex set of regulatory proteins. Our work continues to explore the molecular events responsible for vesicle tethering at the TGN.
Sterol Regulated Ubiquitination and Degradation of HMG CoA Reductase
Authors: DeBose‐Boyd Russell
Published: June 2021

The endoplasmic reticulum (ER) membrane protein HMG CoA reductase catalyzes reduction of HMG CoA to mevalonate, a rate‐determining step in synthesis of cholesterol and nonsterol isoprenoids such as the farnesyl and geranylgeranyl groups that become attached to many proteins. Reductase is subject to stringent feedback control through multiple mechanisms that are mediated by sterol and nonsterol end‐products of mevalonate metabolism. The current focus of research in the DeBose‐Boyd laboratory centers on the mechanism involving rapid degradation of reductase. My presentation will describe studies in which biochemical and genetic tools were used to reveal a prominent role for ER membrane proteins called Insig‐1 and Insig‐2 in reductase degradation. These studies show that accumulation of sterols triggers binding of reductase to a subset of Insigs in complex with the membrane‐bound E3 ubiquitin ligase gp78. This gp78‐Insig interaction mediates reductase ubiquitination, which marks the enzyme for degradation by proteasomes. Regulated degradation reduces the half‐life of reductase protein from 12 h in sterol‐depleted cells to less than 1 h under sterol‐replete conditions, thereby blunting cholesterol synthesis. Reductase is the molecular target of statins, the most widely used drugs for treatment of hypercholesterolemia and prevention of atherosclerosis. Degradation of reductase is an untapped avenue for clinical modulation. Thus, detailed elucidation of mechanisms for reductase degradation holds promise for development of drugs that reduce cholesterol levels and ultimately, the incidence of heart attacks.
Lysophospholipid S1P Receptors in Models of Multiple Sclerosis
Authors: Chun Jerold
Published: June 2021

Lysophospholipids are small, signaling lipids that are best known through the chemical species sphingosine 1‐phosphate (S1P) and lysophosphatidic acid (LPA). These molecules have been implicated in an increasingly broad range of physiological and pathophysiological roles with therapeutic potential and mediated by cell surface G protein‐coupled receptors. A compound called FTY720 (Fingolimod, Novartis) was identified for its immunosuppressive‐like properties. FTY720 is phosphorylated to "FTY‐P", which has been reported to be a high‐affinity, non‐selective agonist for multiple S1P receptors. FTY720 has entered Phase III human trials for the treatment of Multiple Sclerosis (MS), reflecting in part efficacious effects observed in the animal model called Experimental Autoimmune Encephalomyelitis (EAE). Mechanistic EAE studies utilizing conditional genetics and receptor selective pharmacology support novel modes of action on defined S1P receptors. FTY720 (Fingolimod) may represent the first example of a human medicine functioning through lysophospholipid receptor signaling mechanisms. Supported by the NIH (NS048478) and a grant from Novartis Pharma, AG.
Effects of dietary resistant starch on body fat in three different types of mice
Authors: Zhou Jun , Martin Roy J , Tulley Richard T , Raggio Anne M , Shen Li , Lissy Elizabeth , McCutcheon Kathleen L , Keenan Michael J
Published: June 2021

Resistant starch (RS) is a dietary fermentable fiber, which decreases dietary energy density and causes fermentation in the lower gut. We previously showed dietary RS decreases body fat in rats. The current studies examined the effects in lean and obese mice. In a 12 week study, the effect of RS on body fat was compared in C57Bl/6J (lean) mice to two control diets: regular control diet or the control diet that had equal energy density as the RS diet (EC). All test diets had 7% (wt/wt) dietary fat. In a 16 week study, the effect of RS on body fat was compared with EC in lean mice and two obese mouse models. All mice were fed control or RS diet for 6 weeks with 7% dietary fat. At week 7, the dietary fat was increased to 11% for half of the mice. The pH of cecal contents was measured as an indicator of RS fermentation.

Results

Compared with EC, RS decreased body fat and improved glucose tolerance in lean mice, but not in obese mice. RS decreased RER in both lean and obese mice. Dietary fat did not interfere with these results. The pH of cecal contents in RS fed mice was decreased for lean mice but not for obese mice, implying the impaired RS fermentation in obese mice.

Conclusion

1) decreased body fat by RS is not simply due to dietary energy dilution in lean mice, and 2) along with their inability to ferment RS, RS fed obese mice did not show decreased body fat. Supported by the NIH.
Comparison of the satiety effect of protein, fat and carbohydrate preloads with the same energy, volume and palatability.
Authors: Tomé Daniel , Potier Mylène , Fromentin Gilles , Lesdema Aurélie , Benamouzig Robert , Martin‐Rouas Christine , Marsset‐Baglieri Agnès
Published: June 2021

Numerous studies have shown that a protein proload more efficiently induces satiety than fat and carbohydrate. However, there are still some contradictions because of the diversity of designs employed: energy density, volume, palatability, texture of the preloads and the fact that they are common foods or not. The aim of this study was to compare the effect on satiety of different liquid preloads constituted only by protein, fat or carbohydrate in very controlled conditions.

56 subjects have participated to 4 randomised test days, one day per macronutrient and a control day. In each test day, they had to consume the preload entirely (245kcal; 250mL) and their food intake was mesured during the next meals. The volunteers were separed in two groups: the first one (T0) consumed the preload immediatly before lunch and the second one (T1) one hour before.

Whatever the delay, no difference was found on food intake at lunch between the 3 different preloads. In the 2 groups, energy intake of preload and lunch was higher after lipid preload than in the control conditions. In the T0 group, the same result was observed with the protein preload.

Our results do not confirm the higher satiety effect of proteins, may be because we used non common foods as preloads. According to the concept of learned satiety, the results could not be the same if the subjects were previously familiarised to the uncommon tested preloads.
Low carbohydrate diets alter hormones known to mediate central regulation of appetite
Authors: Stadler Diane D , Lin Yueh‐Han , Jordan Julia , Horgan Angela , Clemmons Aaron , Gerhard Glenn
Published: June 2021

Very low carbohydrate (CHO) diets (VLCD) are effective at inducing weight loss due in part to a sense of food disinterest. Those consuming VLCD reduce their energy intake by an average of 25‐30% yet do not feel hungry. To explain this modified eating behavior we characterized 24 h profiles of hormones known to mediate central regulation of appetite in healthy obese adults. Subjects consumed a standard research diet (~50% CHO) for 2 weeks and then were randomly assigned to ad libitum VLCD (n=9; ~4% CHO) or high complex CHO (HCD, n=13; ~58% CHO) research diets for 6 weeks. Blood samples were collected over 24 h at the end of each diet phase. Insulin, leptin, and total ghrelin concentrations were measured in 28 samples and area under the curve (AUC) was calculated for each analyte. Differences in change from baseline in AUC were compared between groups by ANOVA and LSD analysis. Changes in 24 h AUC‐insulin (‐401 ± 119 vs ‐80 ± 38; p< 0.01), 12 h AUC‐leptin (‐0.82 ± 0.23 vs ‐0.26 ± 0.19; p<0.04) and 4 h AUC‐total ghrelin (373 ± 181 vs ‐44 ± 56; p<0.03) were different between VLCD and HCD groups, respectively. Patterns of change over 24 h at 6 weeks were also different between groups for each analyte. These findings suggest that VLCD and HCD differentially impact hormones that influence regulation of appetite and may help explain differences in weight loss between diets, at least in the short term. Supported by PHS grants UL1RR024140 & 5R21AT002753.
Iron fortified milk distributed by a Mexican National program improves the intellectual performance in a cohort of children when consumed 12‐24 mo of age. An effectiveness study.
Authors: Villalpando Salvador , Shamah‐Levy Teresa , Cuevas‐Nasú Lucía , Mundo‐Rosas Verónica , Salazar Coronel Aracelí A.
Published: June 2021

Objective

To evaluate the intellectual performance of a cohort of children consuming iron fortified milk distributed by federal program LICONSA at 7 years of age.

Methods

586 infants 12‐24 mo of age were randomly assigned to receive 400 mL/d, for 1 year, containing either 5.3 (FM) or 0.2 (NFM) mg of iron. A control group never received milk from the program (C). Iron status indicators were superior in FM at 6 and 12 mo follow‐up. When children were 7 years of age, 82% of the original sample was recovered and intellectual performance was evaluated using WISC test.

Results

Global (100 p), execution (111p) and verbal (89p) scales were significantly greater in FM than in NFM (95.7, 107, 84 pp) and than in C (95, 107, 82.8 pp) respectively (p range 0.01‐0.001).

Conclusions

Effectiveness of the program for intellectual improvement is benefited 5 million beneficiaries.

Supported by Liconsa, and Ministry of Social Development SEDESOL.
Assessing the roles of various retinoid‐metabolizing CYP enzymes in liver disease
Authors: D'Ambrosio Diana N. , Kluwe Johannes , Yang Jian Zhang , Jacobs Matt , Schwabe Robert F. , Blaner William S.
Published: June 2021

Development of liver disease (LD) is associated with progressive depletion of hepatic stellate cell (HSC) retinoid‐storing lipid droplets. It is not clear whether this loss is the result of increased hepatic mobilization of retinol or increased retinoid catabolism by hepatic cytochrome P450 (CYP) enzymes. Wild type (WT) mice were treated with CCl4 as a model of experimentally induced hepatic fibrosis (EIHF). We did not observe any alterations in the expression of genes encoding proteins involved in retinoid transport in the livers of WT mice in response to CCl4. However, we did find that EIHF is accompanied by an approximate 4‐fold elevation in CYP26A1 and CYP2S1 mRNA levels. Because retinol uptake and storage in the liver involves both hepatocytes and HSCs, we were interested in understanding how each cell type may contribute to the progression of LD. We isolated hepatocytes and HSCs from the livers of WT mice and generated CYP expression profiles for each cell type. HSCs have approximately 50‐fold higher levels of CYP2S1 mRNA relative to hepatocytes, whereas CYP26A1 is highly expressed in hepatocytes. The high expression of CYP2S1 in HSCs and its induction in EIHF provides evidence for a role of this cytochrome in the progression of LD. Thus, the loss of HSC lipid droplets in LD may arise from increased CYP‐mediated retinoid catabolism and not increased retinol mobilization from the liver.

Grant Funding Source

R01 DK079221
Effects of high vitamin A intake on adipose tissue vitamin A levels in mice with impaired capacity for hepatic vitamin A storage
Authors: Yang Jian Zhang , Wongsiriroj Nuttaporn , D'Ambrosio Diana N. , Blaner William S.
Published: June 2021

Both lecithin:retinol acyltransferase‐ (Lrat−/−) and cellular retinol‐binding protein type I‐ (CrbpI−/−) deficient mice have impaired hepatic vitamin A storage capacity. To gain insight into relationships between hepatic and adipose vitamin A storage, Lrat−/−, CrbpI−/− and Lrat−/−/CrbpI−/− mice were maintained for 4 wks on the basal AIN‐93M diet or this diet supplemented with 25‐fold excess retinol. Liver and adipose retinol/retinyl ester levels were determined by HPLC. Regardless of diet, no retinyl esters were detected in livers of Lrat−/− and Lrat−/−/CrbpI−/− mice; whereas wild type and CrbpI−/− mice respectively had levels of 363±60 and 162±41 on the basal diet and 4272±828 and 763±267 nmol/g on the excess diet. Adipose tissue total retinol levels for Lrat−/−, CrbpI−/−, Lrat−/−/CrbpI−/− and wild type mice fed the basal diet were respectively 10.2±3.1, 9.9±1.4, 8.2±0.4 and 3.2±0.3 nmol/g. On the excess diet the levels for Lrat−/−, CrbpI−/−, Lrat−/−/CrbpI−/− and wild type mice were respectively 153.6±27.2, 137.7± 43.8, 145.9±16.6, and 34.9±4.7 nmol/g. Thus, impaired capacity to store vitamin A in liver increased adipose accumulation of vitamin A for both basal and excess diet groups.
Effects of cytosolic RIP140 in adipocyte glucose uptake
Authors: Lin Yi‐Wei , Ho Ping‐Chih , Gupta Pawan , Tsui Yao‐Chen , Ha Sung Gil , Tsai Nien‐Pei , Wei Li‐Na
Published: June 2021

Receptor interacting protein 140 (RIP140) is a versatile transcriptional co‐repressor and plays roles in metabolic processes. Our previous studies showed that protein kinase C epsilon (PKC epsilon) could trigger RIP140 export to the cytoplasm through coordination of phosphorylation and arginine‐methylation. Here, we found that the expression of cytosolic RIP140 decreased basal and insulin‐stimulated glucose uptake in 3T3‐L1 adipocyte. Targeting PKC epsilon by siRNA or specific inhibitor, a trigger inhibiting RIP140 translocation to cytoplasm, also improves glucose uptake. In RIP140 null adipocyte, re‐expression of RIP140 mutant mimicking PKC epsilon stimulated phosphorylation decreased insulin‐stimulated glucose uptake. Re‐expressing RIP140 mutant deficient in PKC epsilon stimulated phosphorylation had no effects on insulin‐stimulated glucose uptake. These results indicate nuclear PKC epsilon activation promotes RIP140 export from nucleus to cytoplasm, and the cytosolic RIP140 exerts a novel activity in the cytoplasm to regulate glucose uptake and insulin sensitivity in adipocyte.

This work was supported by DA11190, DA11806, DK54733, DK60521, K02‐DA13926 to L.‐N. W.
Zip6 attenuation reduces intracellular zinc pools and potentiates oncogenesis in T47D cells
Authors: Lopez Veronica , Kelleher Shannon L
Published: June 2021

The etiology of breast cancer is unknown; however, compelling evidence implicates dysregulation of zinc (Zn) homeostasis in breast tumor cells. Studies have suggested that over‐expression of Zip6 may be a useful prognostic marker for breast cancer. We hypothesized that aberrant Zip6 expression dysregulates intracellular Zn pools affecting cellular function. Using Q‐PCR, we determined Zip6 gene expression was 2‐fold lower in tumorigenic (T47D) compared with normal human breast (HME) cells, while Zip6 protein abundance was significantly higher (30%) compared with HME cells. Zip6 protein localized exclusively on the plasma membrane in HME cells. In contrast, ~90% of Zip6 protein was located intracellularly in T47D cells. Zip6 attenuation in T47D cells resulted in decreased cytoplasmic Zn pools (28%) as assessed by a luciferase reporter construct. Vesicular and mitochondrial Zn pools were also lower in Zip6‐attenuated cells assessed by FluoZin‐3 AM and RhodZin‐3 fluorophores, respectively. Functionally, this resulted in decreased Bax oligomerization, cytoplasmic cytochrome C release and caspase activities and a concomitant decrease in E‐cadherin mRNA but increased cell number, vimentin mRNA and tumor formation. Together our data suggest that subtle alterations in the cellular Zn microenvironment potentiate oncogenesis through influencing cellular adhesion in tumor cells.
Prenatal Exposure to Disrupted Methyl Metabolism Affects Expression & Allele‐Specific Methylation of H19/Igf2 in Brain
Authors: Wade Rachel E , Boersma Heather , Devlin Angela M
Published: June 2021

Epigenetic processes may play a role in the metabolic programming associated with prenatal nutrition. We studied the effect of prenatal exposure to disrupted maternal methyl metabolism on expression and allele‐specific methylation of H19/Igf2 in brain. H19/Igf2 expression is regulated by a differentially methylated domain (DMD). We studied F1 hybrid offspring from male Cast/EiJ mice and female C57BL6/J mice [with (Cbs+/‐) and without (Cbs+/+) heterozygous disruption of the cystathionine‐ß ‐synthase gene] fed a control or high methionine/low folate (HH) diet during pregnancy. The F1 hybrid offspring were then fed the control or HH diet from weaning for 6 weeks. Independent of prenatal diet, Cbs+/‐ x Cast mice fed the post‐weaning HH diet had higher (P<0.001) plasma homocysteine than Cbs+/+ x Cast mice fed the control diet. This was accompanied by higher (P<0.05) S‐adenosylhomocysteine (SAH), lower (P<0.01) S‐adenosylmethionine/SAH ratios, and lower (P<0.01) Igf2 mRNA in brain. Mice exposed to the prenatal and post‐weaning HH diet had higher (P=0.05) H19 mRNA, lower H19/Igf2 mRNA ratios, and higher (P<0.05) paternal and maternal allele DMD methylation in brain than mice not exposed to the prenatal HH diet. These findings show that prenatal exposure to disrupted maternal methyl metabolism is associated with differential methylation and expression of H19/Igf2 and suggests a role for methyl metabolism in metabolic programming.

Grant Funding Source

CIHR/Sick Kids Foundation, Heart & Stroke Foundation
Unbalanced Fatty Acid Nutrition High in n‐3 Fatty Acids During Early Development Programs Intestinal Permeability and Later Susceptibility to Experimentally‐Induced Colitis in Rats
Authors: Innis Sheila M , Dai Chuanbin , Jacobson Kevan
Published: June 2021

Intrauterine and early postnatal life are periods of physiological plasticity, when adverse environmental events may have long‐lasting effects. The n‐6 and n‐3 fatty acids are important membrane components, precursors for eicosanoids, and ligands for transcription factors. We investigated whether the n‐6 and n‐3 fatty acid supply in gestation and milk‐feeding had enduring effects on colonic barrier integrity and mucosal responsiveness to a chemical insult in rats. Rats were fed diets identical in all nutrients except fatty acids, with 20 % energy from safflower oil to provide high linoleic acid (LA, 18:2n‐6), canola oil with balanced LA and á‐linolenic acid (ALA, 18:3n‐3), or safflower plus fish oil to provide eicosapentaenoic acid (EPA, 20:5n‐3) and docosahexaenoic acid (DHA, 22:6n‐3) throughout gestation and lactation. Male offspring were weaned to chow, and colitis was induced with dinitrobenzene sulfonic acid at 3‐mth age. At 15 days age, colonic crypt depth was highest in the safflower, but paracellular permeability was highest in the fish oil group. Reduced colonic crypt depth and impaired paracellular permeability persisted in fish oil group at 3 mth, with more severe inflammatory response. We show a maternal diet high in n‐3, but low in n‐6 fatty acids has lasting deleterious effects on colonic barrier integrity, predisposing to an exaggerated inflammatory response in later life. Funded by NSERC.
Metabolic syndrome risk is associated with higher CRP levels in young adults
Authors: Morrell Jesse Stabile , Burke Joanne D , Lofgren Ingrid E , Reilly Ruth A
Published: June 2021

Research related to chronic disease risk prevalence in young adults is lacking. The Young Adult Health Risk Screening Initiative, begun in 2005, is an ongoing cross‐sectional investigation of chronic disease risk in college‐age adults (18‐24) at the University of New Hampshire. Metabolic syndrome (MetS) in relation to C‐reactive protein (CRP) levels was examined in a subset of 88 college‐age men. Fasting glucose, triglycerides, HDL‐C and CRP were measured by fingerstick (Cholestech® LDX). Blood pressure, height, weight, and waist circumference were measured according to standard protocols. MetS criteria include abdominal obesity (waist circum. = 40 in), hypertrigylceridemia (= 150 mg/dl), low HDL‐C (< 40 mg/dl), hypertension (= 130 mm Hg systolic or = 85 mm Hg systolic), and elevated glucose (= 100 mg/dl). Mean CRP levels were 1.3 ± 0.2 mg/L; mean number of MetS criteria was 1.4 ± 0.1. CRP levels were higher among young men with BMI = 25 as compared to those with BMI < 25 (1.6 vs. 0.8 mg/L, p < 0.05). CRP levels were higher among participants with abdominal obesity (1.9 vs. 1.1 mg/L, p < 0.01) and elevated glucose (2.4 vs. 0.8 mg/dl, p < 0.01). After controlling for BMI, recent cold symptoms, and family history of heart disease, CRP levels were positively related to the number of MetS criteria (r2=0.27, p < 0.05). Findings suggest that the inflammatory marker CRP is associated with MetS criteria in young, college‐age men.

Supported in part by the UNH Dietetic Internship.

Grant Funding Source

None
Acute consumption of walnuts decreases CRP levels in healthy individuals, with high CRP
Authors: Grieger Jessica A , West Sheila G , Kris‐Etheron Penny M
Published: June 2021

Elevated C‐reactive protein increases risk for diabetes, hypertension and CVD. Dietary fatty acids, nutrients and bioactives, including antioxidants, modulate many risk factors for CVD, chronically and acutely. Walnuts are a rich source of antioxidants, unsaturated fats, and bioactives. In a randomized, cross‐over postprandial study, we evaluated the acute effects of whole walnuts (85 g) vs. walnut components (skins: 5.6 g; nut meat: 34 g; oil: 51 g) on CRP in healthy adults with moderate hypercholesterolemia. Blood samples were taken at fasting, and 0.5, 1, 2, 4, and 6 hr post meal. Fifteen participants completed the study (mean (SD) age: 49.8 (8.7) yrs; BMI: 29.3 (3.6) kg/m^2;). Four, five and six participants had low (<3 mg/L), normal (1‐3 mg/L) and high (>3 mg/L) fasting CRP concentrations, respectively. Whole walnut consumption reduced CRP at 1 hr (mean ?: ‐1.1 ± 0.7 mg/L, P=.012) in those who had high CRP, compared to an increase in those with low CRP (mean ?: +1.3 ± 0.6 mg/L). CRP also decreased at 1 hr following nut meat consumption in those with high (‐1.1 ± 0.3 mg/L, P=.040) vs. low CRP. Sustained reductions in CRP at 2, 4 and 6 hr also were found in those who had high vs. normal and low CRP levels (all P=0.005). There were no effects of walnut skins or oil on CRP. Consumption of whole walnuts and walnut meat decreases the postprandial inflammatory response in individuals with elevated CRP, which may reduce risk for CVD.
Pilot testing automatic mobile phone imaging coupled with 24 hour recalls: Image Diet Day
Authors: Arab Lenore , Burke Jeffrey Aaron , Estrin Deborah
Published: June 2021

Dietary recalls are subject to intrusions and omissions of foods due to imperfect memory. To remedy this we coupled automated imaging with a computer assisted 24‐hour recall for feasibility in 14 subjects. Mobile phones worn around the neck were programmed to autonomously capture and transmit images every 10 seconds. A website presented these the following day to subjects conducting a web based 24‐hour recall. Logistic issues included IRB concerns, proper phone positioning, adequate energy reserves to continually transmit images and development of user‐friendly software to present a manageable number of images. Phone usage was monitored through transmitted images. Subjective responses to their experience with the camera showed 79% of participants having no technical problems. 93% found the images to be helpful. Across these users there were 110 distinct eating episodes and 11,090 images uploaded. There was an average of 101 images per episode, ranging from a max of 775 to a minimum of 1; reflecting the diversity of short snacks and longer meals across study participants. Image processing filters developed to prune out under‐exposed, over‐exposed, and blurry images introduced only seconds of processing overhead. Participants provided invaluable feedback on their experiences with the phones, how to improve the camera phones, how to support their wear and concerns about their operation.
Protein Intake and Incident Frailty in the Women's Health Initiative Observational Study
Authors: Beasley Jeannette M , LaCroix Andrea Z , Neuhouser Marian L , Huang Ying , Tinker Lesley F , Woods Nancy F , Michael Yvonne , Curb J David , Prentice Ross L
Published: June 2021

Data from short‐term clinical trials suggest current protein recommendations may not be optimal for elderly individuals, but few data are available from population‐based cohorts. We prospectively evaluated the association between protein intake and incident frailty in the WHI‐OS. Postmenopausal women aged 65‐79 years at baseline who were free of frailty and with plausible self‐reported energy intakes (600‐5000 kcal/day) by Food Frequency Questionnaire (FFQ) were included. Protein intake was measured at baseline using the WHI FFQ and energy and protein intake were corrected for measurement error using regression calibration equations estimated from biomarker data. After three‐years of follow‐up, frailty was defined as having at least three components: low physical function, exhaustion, low physical activity, and unintended weight loss. Multinomial logistic regression models estimated associations for both uncalibrated and calibrated protein intake. Among the 24,417 eligible women, 3,298 (13.5%) developed frailty. After adjustment for confounders, a 20% increase in uncalibrated protein intake (%kcal) was associated with a 12% (95% CI: 8% to 16%) decrease in frailty, while a 20% increase in calibrated protein was associated with a 32% (95% CI: 23% to 44%) decrease in frailty. Insufficient protein intake may be an intervention target for frailty prevention. Funded by NHLBI and NIA.
Rapid reversal of human intestinal ischemia‐reperfusion induced damage by shedding of injured enterocytes and reepithelialisation
Authors: Grootjans Joep , Derikx Joep PM , Matthijsen Robert A , Thuijls Geertje , de Bruïne Adriaan P , van Bijnen Annemarie A , van Dam Ronald M , Buurman Wim A , Dejong Cornelis HC
Published: June 2021

Intestinal ischemia reperfusion (I‐IR) has primarily been studied in animal models whereas human data on I‐IR are scarce. We developed a harmless human experimental model aiming to unravel the sequelae of human small I‐IR.

In this model, an isolated part of jejunum, to be removed for surgical reasons, was subjected in vivo to various ischemic periods by vascular clamping, followed by reperfusion. Damage to the intestinal barrier was objectified with immunohistochemistry for morphology (H/E), tight junction proteins (TJ) ZO‐1 and Claudin‐3, apoptosis marker M30, cytokines and neutrophil activation products. To assess epithelial cell damage, arteriovenous (V‐A) concentration differences of Intestinal‐Fatty Acid Binding Protein (I‐FABP) were measured.

Jejunal histology revealed the appearance of subepithelial spaces after 30 minutes ischemia (fig 1B, normal tissue: fig 1A) with loss of TJ. Mean (SEM) I‐FABP release significantly increased immediately upon reperfusion (fig 2: 290 (46) to 3997 (554) pg/ml, p<0.001). After 25 minutes reperfusion massive apoptosis and shedding of damaged enterocytes into the lumen was seen (fig 1C). Within 60 minutes of reperfusion the epithelial barrier was fully restored, while debris of apoptotic, shedded enterocytes was found in the lumen (fig 1D). This study revealed a unique gut‐specific mechanism of the reversal of IR‐induced intestinal damage.
Lactobacillus rhamnosus prevents inflammatory signaling in immature murine intestines via generation of reactive oxygen species
Authors: Lin Patricia , Berardinelli Andrew , Nasr Tala , Ray Laurie , Hansen Jason , Neish Andrew
Published: June 2021

Immature intestinal defense plays a key role in the pathogenesis of necrotizing enterocolitis (NEC), a devastating disease of premature infants. Here, we show that inflammatory responses in neonatal mouse intestines increase during postnatal maturation with peak responses occurring at 2 weeks of life. Furthermore, we show that these inflammatory responses can be prevented by prior oral administration of the probiotic Lactobacillus rhamnosus (LGG). Probiotic bacteria can block inflammatory responses in adult intestinal epithelia by inducing generation of reactive oxygen species (ROS) which inhibit NF‐¿B activation through oxidative inactivation of the Cul‐1 neddylation enzyme, Ubc12. To determine whether LGG can reduce exaggerated inflammatory responses in immature intestines via a similar mechanism, we measured the effect of LGG on GSH oxidation and loss of neddylated Cul‐1 in immature murine small intestines. Intestines from immature mice gavage fed LGG exhibited increased GSH oxidation and Cul‐1 deneddylation reflecting local ROS generation and its resultant Ubc12 inactivation, respectively. These studies indicate that LGG can reduce inflammatory signaling in immature intestines by inducing local ROS generation and may be a mechanism by which probiotic bacteria can prevent NEC in premature infants.
Evidence for leukocyte JAM‐A—mediated regulation of intestinal inflammation
Authors: Peatman Eric James , Capaldo Christopher , Nava Porfirio , Lee Winston , Williams Ifor , Parkos Charles
Published: June 2021

Junctional adhesion molecule‐A (JAM‐A) is an adhesion molecule expressed on epithelial, endothelial, and hematopoietic cells that has been shown to play a role in the regulation of intestinal permeability and cell migration. Recent studies have demonstrated that deficiency of JAM‐A in mice (JAM‐A−/−) results in enhanced intestinal mucosal permeability and inflammation, however, the role of JAM‐A in different cell types potentially contributing to the above observed intestinal phenotype is not well defined. In this study, we used bone marrow (BM) chimeras to observe that: 1) Loss of tissue‐derived JAM‐A, but not hematopoietic JAM‐A, leads to increased intestinal permeability; 2) Mice with compromised intestinal barrier function (JAM‐A−/−) implanted with wild‐type (WT) BM developed severe clinical disease and mucosal injury during experimental colitis. Extent of injury and immune cell infiltration was significantly greater than that observed in JAM‐A−/− mice or chimera controls; 3) WT mice with JAM‐A−/− BM showed significantly lower levels of disease and mucosal injury during colitis than WT mice or chimera controls. Collectively, these findings suggest that loss of JAM‐A on leukocytes results in an impaired, but protective response to mucosal inflammation. Research was supported by T32 and R01 grants from the NIH.
The Homeostatic Pressure Exerted by Stem Cells in Degenerative or Injured CNS Environments
Authors: Snyder Evan Y.
Published: June 2021

We have most recently been studying, an intriguing phenomena, (with possible therapeutic implications) that has begun to emerge from our observations on the behavior of neural stem cell (NSC) clones in various mouse and primate models of CNS injury & degeneration. During phases of active neurodegeneration, factors seem to be transiently elaborated to which NSCs may respond by migrating (even long distances) to degenerating regions where they attempt to restore homeostasis by a variety of mechanisms. This may include, (but is not limited to) differentiating, towards the replacement of degenerating neural cells of multiple types, not only neurons but also requisite non‐neuronal "chaperone" cells, all of which are essential for the proper development and reconstitution of function. NSC's are drawn to inflammatory niches, where they then exert anti‐inflammatory actions. These "repair mechanism" may also reflect the re‐expression of basic developmental programs (particularly during temporal "windows" following injury). There is an enormous amount of "programmed" cross‐talk between stem cells and the milieu that add complexity but also enrich therapeutic promise to the system. In addition, NSCs in their native state (as well as following genetic‐engineering) may serve as vehicles for protein delivery allowing for the possibility of simultaneous cell replacement & gene therapy (e.g., with factors that might enhance differentiation, neurite outgrowth, connectivity, neuroprotection, anti‐inflammation, anti‐scarring, and angiogenesis). Cell‐cell contact with communication through gap junctions appears to represent another mode of cross‐talk. Multi‐model approaches to most neurological conditions are likely required. The stem cell may serve as the "glue" for these. When combined with certain synthetic biomaterials, NSCs may be even more effective in "engineering" the damaged CNS towards reconstitution. Not only gene expression programs, but also an epigenetic chromatin modification programs seem critical for dictating plasticity and potency. These chromatin structures appear to influence the expression of various stemness genes, including some novel zinc finger proteins that influence the unfolding of various developmental programs along the continuum from pluripotence (as ES cells) to multipotence (as somatic stem cells, e.g., NSCs) to cell type commitment (e.g., as neural cell types).
Neurovascular development utilizes VEGF‐A signaling to regulate blood vessel ingression into the neural tube
Authors: Bautch Victoria L , Gewolb Cara , James Jennifer M
Published: June 2021

Neurovascular development requires communication between two developing organs, the neuroepithelium and embryonic blood vessels. We investigated the role of VEGF‐A signaling in the embryonic cross‐talk required for ingression of angiogenic vessel sprouts into the developing neural tube. As the neural tube develops, blood vessels enter at specific points medially and ventrally from the surrounding perineural vascular plexus. Localized ectopic expression of heparin‐binding VEGF165 or VEGF189 from the developing avian neural tube resulted in supernumerary blood vessel ingression points and disrupted vessel patterning. In contrast, localized ectopic neural expression of non‐heparin‐binding VEGF121 did not produce supernumerary blood vessel ingression points, although the vessels that entered the neural tube became dysmorphogenic. Localized loss of endogenous VEGF‐A signaling in the developing neural tube via ectopic expression of the VEGF inhibitor sFlt‐1 locally blocked blood vessel ingression. The VEGF pathway manipulations were temporally controlled and did not dramatically affected neural tube maturation and patterning, or the patterning of radial glia, indicating a direct role for neural‐derived VEGF‐A in the spatially localized molecular cross‐talk required for neurovascular development and vessel patterning in the developing neural tube.
Developmental roles of EGFL7: Vasculogenesis and male germ cell differentiation
Authors: Durrans Anna , Campagnolo Luisa , Stuhlmann Heidi
Published: June 2021

EGFL7 is expressed in mouse embryonic stem cells (ESC), endothelial cells (EC), primordial germ cells (PGC), and recently this lab has shown expression in spermatids and spermatozoa. Our aim was to investigate the role of EGFL7 during vasculogenesis. Egfl7 was knocked‐down in mouse ESCs using lentiviral constructs with siRNA and eGFP sequences. Using the in vitro embryoid body model we found that Egfl7 knock‐down (k/d) was associated with sheet‐like EC structures, consistent with studies of mouse aortic ring, and zebrafish k/d, models. Eight chimeric males derived from k/d ESC clones were crossed with WT females. Unexpectedly, transmission of the k/d construct was not seen in pups, embryos, or blastocysts. Further investigation revealed absence of eGFP+ maturing sperm cells in chimeras, suggesting that k/d of Egfl7 prevents germ cell maturation past the PGC stage. In testicular tissue presence of the Egfl7 k/d construct in ECs was associated with atrophy in 15% of the parenchyma. These results suggest a developmental role for EGFL7 in EC migration and cord‐formation during angiogenesis, and a second role during the differentiation of male germ cells. Funding provided by NIH grant R21 HL082098 to HS.
Neuropilin 1 controls cardiovascular development through neural crest cells
Authors: Ruhrberg Christiana , Maden Charlotte , Schwarz Quenten
Published: June 2021

Neural crest cells (NCCs) are highly motile embryonic stem cells that delaminate from the neural tube early in embryogenesis and give rise to several cell types in the cardiovasculature. In particular, they form the pericytes that associate with head vessels, the smooth muscle cells on the pharyngeal arch arteries and the sympathetic neurons that innervate the dorsal aorta and great arteries. Here we show that NRP1 controls NCC differentiation into smooth muscle cells on pharyngeal arch arteries and thereby promotes their remodelling into a functional arteriovenous system. Moreover, NRP1 signalling restricts NCC migration alongside intersomitic blood vessels to promote the association of sympathetic NCCs with the dorsal aorta. Accordingly, NRP1 is essential for cardiovasculature function by controlling both the morphogenesis of the great arteries and their subsequent innervation. This work was funded by the UK Medical Research Council.