bluuebunny/crossref_metadata_2025 huggingface dataset:
Heterogeneity in human plasma Selenoprotein P: variable glycosylation status and protein length
Authors: Jackson Matthew I , Combs Gerald F
Published: June 2021

Selenoprotein P (SEPP1) is synthesized in the liver where it incorporates selenium (Se)and is exported to plasma. SEPP1 comprises 30–60% of total plasma Se, depending on the level of Se (particularly, selenomethionine) intake. The distribution of Se from plasma SEPP1 to peripheral tissues is thought to invol ve enzymatic cleavage of the carboxy terminus of the protein (which contains 9 of its 10 SeCys residues) by target cells. To date, two isoforms of human plasma SEPP1 differing in apparent molecular weight have been reported; these differed in protein length, not glycosylation status. Their relative concentrations have been suggested as indicators of cancer risk and nutritional Se status. Here, we report three additional SEPP1 isoforms in human plasma, consisting of both shortened variants and alternative glycosylation products. Utilizing three independent chemical affinity methods and immunoprecipitation, we have enriched SEPP1 from human plasma and characterized the molecular weight, isoelectric point and mass spectra of the glycoforms and their deglycosylated congeners. These novel isoforms differ in polypeptide length and glycosylation status. We expect that their distribution may reflect physiological and/or nutritional status, and are conducting further work to determine their responses to Se‐supplementation. Support – USDA/ARS.
Role of the 15kDa selenoprotein (Sep15) in colon cancer prevention
Authors: Tsuji Petra , Irons Robert , Carlson Bradley , Yoo Min‐Hyuk , Xu Xue‐Ming , Formenko Dmitri , Gladyshev Vadim , Hatfield Dolph , Davis Cindy
Published: June 2021

Selenium has cancer preventive activity that is partly mediated through selenoproteins. shRNA knockdown of Sep15 in mouse colon carcinoma CT26 cells inhibited their anchorage‐dependent and ‐independent cell growth, primary tumor growth and lung metastasis. In contrast, Sep15 knockdown in Lewis Lung carcinoma cells did not affect anchorage‐dependent or –independent growth. To investigate molecular targets, mRNA from control and knockdown CT26 cells was analyzed using Affymetrix gene chips. Ingenuity Pathways Analysis was used to analyze the 1045 genes that were significantly (p<0.0001) different between shSep15 and control cells. The two highest scored biological functions were cancer and cellular growth/proliferation. Subsequent FACS analysis confirmed a G2/M cell cycle arrest in shSep15 knockdown cells. To investigate the effect of Sep15 knockout in vivo, mice were treated with azoxymethane. Sep15 knockout mice had significantly fewer carcinogen‐induced aberrant crypt foci in their colon than control mice. These data suggest tissue specificity in the cancer protective effects of Sep15, which are mediated, at least in part, by influencing cell cycle. Furthermore, Sep15 knockout mice appear to be protected against chemically‐induced colon cancer. Funded by NCI Intramural support, the Cancer Prevention Fellowship Program and the Division of Cancer Prevention.
Selenium ablates Friend Virus induced Erythroleukemia in mice
Authors: Kaushal Naveen , Hegde Shailaja N , Hankey Pamela A , Paulson Robert F , Prabhu K. Sandeep
Published: June 2021

Selenium (Se), an essential micronutrient is reported to have anti‐inflammatory and anti‐tumorigenic properties. Recently, we have reported that anti‐inflammatory role of Se is mediated, in part, through the production of 15d‐PGJ2, a cyclopentanone prostaglandin D2 metabolite. Cyclopentanone prostaglandins, including 15d‐PGJ2, display anti‐inflammatory and anti‐proliferative properties. We hypothesize that Se acts through the production of 15d‐PGJ2 to mediate the anti‐carcinogenic effect by targeting cancer stem cells. In the current study, murine Friend‐virus (FVP) induced erythroleukemia model was used to examine the effect of Se and 15d‐PGJ2 on the ablation of spleen derived‐ leukemia stem cells (LSC), characterized by the expression of gp55, Sca, Kit, and Ter119. These cells retained the ability to proliferate in transplantation models and cause clonal leukemia. Infection of Balb/c mice fed on Se‐supplemented diets with FVP clearly protected the mice from splenomegaly; while those on Se‐deficient diet succumbed to infection. Furthermore, experiments with in‐vivo administration of 15d‐PGJ2 at physiologic doses also demonstrated a similar effect. Here we discuss the mechanisms of chemopreventive action of 15d‐PGJ2 and Se from the point of cancer stem cell apoptosis. NIH DK 077152

Grant Funding Source: NIH
Curcuminoids from tumeric (Curcuma longa) target microRNA148 and microRNA146 in their anti‐inflammatory effects in non‐cancer colon cells
Authors: Noratto Giuliana , Angel‐Morales Gabriela , Follo Armando Del , Tian Yanan , Mertens‐Talcott Susanne
Published: June 2021

The anti‐inflammatory properties of tumeric have been investigated in multiple studies, however the involvement of microRNAs in anti‐inflammatory properties of natural compounds has not been much investigated yet. We studied the potential protective effects of a standardized curcuminoid extract against inflammation induced by lipopolysacharide (LPS) in CCD‐18Co colon cells and investigated underlying miRNA based mechanisms. We investigated miRNAs 146, which is regulated by NF‐kB and involved in the regulation of the TLR4 pathway and also microRNA148a which is a regulator of pregnane X receptor (PXR) a transcription factor involved in the regulation of drug‐metabolizing enzymes and drug transporters as well as in the suppression of NF‐kB. LPS significantly induced the expression of all inflammatory biomarkers by up to 2 fold. The extract significantly reduced the expression of inflammatory biomarkers including NF‐kB, IL‐6, IL‐8, TRAF6, TLR‐4 up to 0.9, 0.2, 0.4, 0.32, and 0.1 fold of control cells. The expression of microRNA146 and 148a were increased by LPS up to 30% and reduced by curcuminoids by 30 and 25% respectively. Overall, these data confirm the anti‐inflammatory effects of curcuminoids in colon and indicate the involvement of microRNAs 146 and 148a in the anti‐inflammatory effects of curcuminoids.

Grant Funding Source: ASN
Viscous dietary fibers reduce visceral adiposity, lower oxidative stress and improve glucose control in ZDF rats
Authors: Brockman David Andrew , Chen Xiaoli , Gallaher Daniel D
Published: June 2021

Viscous dietary fibers have been shown to blunt the postprandial rise in blood glucose. Previous studies in this lab have suggested that viscous dietary fibers decrease adiposity in rats with little or no change in body weight. The aim of this study was to examine the effect of consumption of viscous dietary fibers, hydroxypropyl methylcellulose (HPMC) and β‐glucans (Sustagrain), in an obese diabetic rat model. Zucker Diabetic Fatty (ZDF) rats and their lean counterparts (n=12) were fed diets containing either 5% non‐viscous cellulose, low viscosity (LV) HPMC, high viscosity (HV) HPMC or 40% Sustagrain flour. After 6 weeks of feeding, the HV HPMC group had a reduced percentage epididymal fat pad weight (visceral fat) compared to the other ZDF groups, but no differences in percentage inguinal (subcutaneous) fat pad weights were found. Fasting plasma leptin did not differ among the ZDF groups. Rats fed HPMC and Sustagrain had lower percent glycated hemoglobin and kidney weights than the cellulose group, indicating improved glycemic control. Urinary 8‐isoprostane concentrations in the ZDF cellulose, LV HPMC and Sustagrain groups were significantly higher than the lean group, but HV HPMC and lean groups did not differ. These results indicate that consumption of viscous dietary fiber can lower visceral adiposity and oxidative stress and improve diabetic control in ZDF rats. (Supported by the MN Agric Exp Station)

Grant Funding Source: MN Agric Exp Station/CHE Administative Fund
Cavity ring‐down spectrometer for total energy expenditure using doubly‐labeled water
Authors: Richman Bruce A. , Schoeller Dale A. , Thorsen Tom , Shriver Tim , Crosson Eric R.
Published: June 2021

Understanding obesity and weight control, a health problem of epidemic proportions, includes increased use of total energy expenditure (TEE) measurements using the doubly labeled water method (DLW). Unfortunately, until now, the DLW method required expensive and operationally complex isotope ratio mass spectrometry (IRMS), which has restricted the widespread use of the DLW method. To address this limitation, we developed a commercial DLW analyzer based on wavelength‐scanned cavity ring‐down spectroscopy (WS‐CRDS). This table‐top analyzer measures both isotopic ratios of water directly (δ18O/16O and δD/H). Advantages of WS‐CRDS include less user training, no chemical conversion of the water specimen, no high vacuum system, a smaller footprint, and less capital investment. We compared measurements of water and 14 sets of urine samples using both WS‐CRDS and IRMS. The within‐day precision for natural abundance and enriched water standards were 0.26‰ and 0.04‰ for δD/H and δ18O/16O for_the WS‐CRDS; compared to 0.92‰ and 0.05‰ for IRMS. The mean within‐subject difference (±SD) between instruments for total body water was 0.2±0.4 kg (CV=0.5%) and that for TEE was 22±158 kcal/d (CV=5%). The major limitation of WS‐CRDS was a memory between successive specimens for deuterium of 6%, requiring that each specimen be injected at least five times in succession. This work was supported by NIH grant R44 RR021297.
A blend of soluble fiber and resistant starch promotes feelings of fullness in humans
Authors: Klosterbuer Abby , Sanders Lisa , Potter Susan , Thomas William , Slavin Joanne
Published: June 2021

Some research suggests that high fiber foods cause greater satiety than low fiber foods. The mechanism is unclear, but may be related to the glycemic and insulin response to a meal. This randomized, double‐blind, crossover study examined differences in satiety scores and postprandial glucose and insulin concentrations among different types and combinations of fiber. On 5 occasions, subjects (n=20) consumed either a low‐fiber control breakfast or 1 of 4 breakfasts containing 25 g fiber from soluble corn fiber (SCF) or resistant starch (RS), alone or in combination with pullulan (SCF+P and RS+P), a soluble fiber. All breakfasts were equal in calories and macronutrients. Plasma glucose and insulin were measured and satiety was assessed via visual analog scales (VAS) for 3 hours after breakfast. Results were analyzed as area under the curve (AUC). The RS+P treatment caused significantly greater fullness than the control (p<0.05). While there was a trend of increased fullness with the other fiber treatments, no other significant differences in satiety were observed. Despite equal available carbohydrates, glucose and insulin AUC were significantly reduced for RS (p=0.03) and RS+P (p=0.01) compared to control. This indicates that a blend of soluble and insoluble fiber may be more effective in promoting satiety and favorably altering postprandial blood parameters. Supported by Tate & Lyle Health & Nutrition Sciences.

Grant Funding Source: Supported by Tate & Lyle Health & Nutrition Sciences
Sugar intake and cardio metabolic risk factors in high BMI African American children
Authors: Sharma Sushma , Roberts Lindsay S , Hudes Mark L , Lustig Robert H , Fleming Sharon E
Published: June 2021

Aim

To evaluate the relationship between intakes of subgroups of energy‐providing carbohydrate, and markers of cardio metabolic risk factors in high BMI African American (AA) children.

Methods

A cross sectional analysis was performed on data from a sample of 9–11 year old children (n=80) with BMI greater then the 85th percentile. Fasting hematological and biochemical values for selected markers were related to carbohydrates intake.

Results

After adjusting for gender, pubertal stage and WC, multivariate regression analysis showed that higher intakes of carbohydrate energy (fat and protein held constant) were associated with higher VLDL‐C, IDL‐C, TG and hepatic insulin resistance (HOMA‐IR). After dividing carbohydrate into non‐sugar versus sugars, both groups contributed to increased VLDL‐C, IDL‐C & TG whereas increased sugars accounted for the higher HOMA‐IR and lower adipocyte FA insulin sensitivity (ISI‐FFA). Further dividing sugar into the food group showed that sugar from the candy/soda was associated with increased TG and sugars from the fruit and dairy was associated with lower ISI‐FFA.

Conclusions

Increased intakes of carbohydrates from many subgroups are significantly associated with increases in key markers of cardio metabolic risk in high BMI AA children. This analysis suggests that increases in many types and sources of carbohydrate energy may be detrimental to cardio metabolic health in children.
The effects of macronutrient self‐selection and sucrose form on energy intake, body composition, and aspects of the metabolic syndrome in rats
Authors: Apolzan John W. , Harris Ruth B.S.
Published: June 2021

The effects of macronutrient self‐selection and sucrose form on energy intake, percent body fat, insulin tolerance, and fasting serum triacylglycerol (TG) were determined in young adult male Sprague Dawley rats over 21 days. In experiment one, 24 rats were weight matched to control (chow), sucrose (chow and 30% sucrose solution), or choice (chow, 30% sucrose solution, and lard) diets. Energy intake of sucrose rats was 25% chow and 75% sucrose while energy intake of choice rats was 27% chow, 32% sucrose, and 41% lard. Energy intake, body weight gain, and percent body fat were higher in the sucrose (1872±31 kcal/21d, 44±5 g/21d, 9.4±0.7%) and choice (1894±45 kcal/21d, 50±6 g/21d, 11.2±0.7%) rats than controls (1260±31 kcal/21d, 11±4 g/21d, 5.2±0.4%). Choice rats were less insulin sensitive than control or sucrose animals. TG were higher in sucrose (105±4 mg/dL) than control (58±4 mg/dL) or choice (75±9 mg/dL) rats. In experiment two, 16 rats were weight matched to either a 20% protein, 35.5% sucrose, 34.5% starch, and 10% fat diet or a 20% protein, 70% sucrose, and 10% fat diet. There were no differences in energy intake, body weight gain, percent body fat, insulin sensitivity, or fasting TG after 21 days. Thus, liquid, but not solid dietary sucrose promotes obesity. Macronutrient self‐selection influences the development of specific aspects of the metabolic syndrome independent of adiposity.

Support: NIH R01 DK53903
Development and validation of an algorithm to establish a total antioxidant capacity database of U.S. diet
Authors: Floegel Anna , Kim Dae‐Ok , Chung Sang‐Jin , Song Won O. , Koo Sung I. , Chun Ock K.
Published: June 2021

The present study was designed to develop and validate an algorithm to estimate total antioxidant capacity (TAC) of the U.S. diet. Vitamin C equivalent antioxidant capacities (VCEAC) of individual antioxidant nutrients and 50 popular antioxidant‐rich food items in the U.S. diet were determined by 2,2′‐azino‐bis‐3‐ethylbenzthiazoline‐6‐sulphonic acid (ABTS) assay. According to the algorithm, theoretical TAC for each food item was calculated as the sum of the product of antioxidant content and antioxidant capacities of individual antioxidant nutrients. The top ten TAC food items in the U.S. diet according to standard serving size were blueberry > plum > green tea > strawberry > green tea (decaffeinated) > red wine > grape juice > black tea > cherry > grape. Major contributors to TAC were total phenolics (r = 0.952, p < 0.001) and flavonoids content (r = 0.827, p < 0.001) of 50 food items. Theoretical TAC was positively correlated with experimental TAC (r = 0.833, p < 0.01) and with TAC from the USDA database for the oxygen radical absorbance capacity (ORAC) (r = 0.484, p < 0.01, n = 44). This study validates that TAC measurement based on VCEAC can be employed to establish a TAC database of the U.S. diet. In future studies, TAC of the U.S. diet can be calculated and linked to biomarkers of chronic disease.

Grant Funding Source: Supported by Beginning Grant in Aid (BGIA) No. 0865092E from the American Heart Association and University of Connecticut Faculty Large Grant
Determining BMI cut points based on excess percent body fat in US children and adolescents
Authors: Nguyen Tuan T , Butte Nancy F , Nicklas Theresa A
Published: June 2021

Current cut points for overweight were derived statistically from BMI distribution. The study aimed at determining age‐, gender‐, and ethnic‐specific BMI cut points based on excess body fat in US children and adolescents aged 8–17 years, who participated in the National Health and Nutrition Examination Surveys (NHANES) 1999–2004. Excess body fat was defined as % body fat ≥ 25% in boys and ≥ 30% for girls. Receiver operating characteristic curves were used to define optimal BMI levels for excess % body fat by age, gender and ethnicity. Logarithmic regression across age groups was used to predict optimal BMI cut points. Sensitivities and specificities for the detection of elevated % body fat were compared with the 85th percentiles of the CDC BMI growth charts. Optimal BMI cut points increased with the order from non‐Hispanic white, Mexican American, to non‐Hispanic black boys; Mexican American, non‐Hispanic‐white, to non‐Hispanic‐black girls. Compared to the 85th percentiles of the CDC BMI growth charts, these optimal BMI cut points had lower sensitivities and higher specificities in boys (except for < 10‐year‐old whites) and had higher sensitivities and lower specificities in girls (except for blacks). The ethnic variation in optimal cut points based on excess % body fat suggests a more specific BMI guideline to identify children with excess body fat.
Pre‐ and postnatal arsenic exposure and growth of infants and young children: a cohort study in rural Bangladesh
Authors: Saha Kuntal K. , Hamadani Jena D. , Rasmussen Kathleen M. , Vahter Marie
Published: June 2021

During pregnancy, maternal arsenic exposure via drinking water is associated with fetal loss, small size at birth, infant morbidity and mortality. In contrast, little is known about the effects of pre‐ and postnatal arsenic exposure on growth of infants and young children. We studied this in 2372 infants born to mothers enrolled in a large community‐based intervention trial in rural Bangladesh. Arsenic exposure was assessed by arsenic metabolites in mothers' (8 and 30 wk of gestation) and children's (18 mo) urine, measured by hydride generation on line with AAS or ICP‐MS. Children's weight and length were measured monthly in the first and quarterly in the second year. General linear models were used to examine the association of arsenic exposure with child growth adjusted for potential confounders. Median (interquartile range) urinary arsenic of mothers at 8 and 30 wk of gestation was 81μg/L (37–207 μg/L) and 84 μg/L (42–230 μg/L), respectively. Children's urinary arsenic at 18 mo was 34 μg/L (18–79 μg/L). Neither maternal nor child urinary arsenic was associated with attained weight, length, and anthropometric indices. Thus, despite high exposure, there was no effect of arsenic on growth during infancy and early childhood. It remains unknown whether other manifestations of arsenic exposure on child health and development will appear as they get older. (This study was funded by Sida, EU PHIME and Karolinska Institutet)
Aberrations of methyl group and homocysteine metabolism during the progression of diabetes in the ZDF rat
Authors: Williams Kelly T. , Schalinske Kevin L.
Published: June 2021

Altered methyl group and homocysteine (Hcy) metabolism was tissue‐specific, non‐transient, and preceded hepatic DNA hypomethylation in STZ‐induced type 1 diabetes. Similar perturbations occur in the Zucker (type 2) diabetic fatty (ZDF) rat, but the tissue specificity and effect of disease progression are unknown. ZDF and lean rats were killed at 12 and 21 wk of age. At 12 wk, hepatic glycine N‐methyltransferase (GNMT), methionine synthase, and cystathionine β‐synthase (CBS) activity/abundance were increased, whereas plasma Hcy was decreased in ZDF rats. At 21 wk, GNMT was induced in liver and kidney. In liver only, there was a trend toward increased CBS protein abundance (78%, p = 0.080) and betaine‐Hcy methyltransferase mRNA expression (~100%, p = 0.098). Phosphatidylethanolamine methyltransferase activity tended to be lower in ZDF liver (p =0.071) despite an increase (p < 0.05) in mRNA expression. Hcy levels were decreased in plasma and kidney, but not in liver, at 12 and 21 wk. Elevated glutathione concentrations in liver and kidney at 12 wk, and in kidney at 21 wk, suggests altered regulation of redox homeostasis. Hepatic genomic DNA was hypermethylated at 12 and 21 wk, with a trend toward increased DNMT1 mRNA expression (p = 0.08) at 21 wk. In summary, alterations of methyl group and Hcy metabolism, redox status, and epigenetic regulation result during the progression of type 2 diabetes. Support: Am. Heart Assn.
Genetic polymorphisms in bovine ferroportin are associated with longissimus dorsi muscle iron content
Authors: Duan Qing , Reecy James , Tait Richard , Liu Qi , van Eenennam Allison , Mateescu Raluca , Garmyn Andrea , Beitz Donald
Published: June 2021

We hypothesized that genetic polymorphisms in ferroportin (Fpn), the only known cellular iron exporter, could influence muscle iron content. The objective of this study was to identify single nucleotide polymorphisms (SNPs) in the exons and flanking regions of the bovine Fpn gene and to evaluate the extent to which they were associated with beef iron content. Longissimus dorsi muscle samples were collected from 1086 head of purebred Angus cattle for iron quantification and DNA extraction. All exons and flanking regions of Fpn were sequenced. Eight novel SNPs were identified, among which NC 007300: g.19208 C>T genotype was associated significantly with iron content (P < 0.005). Cattle with the g.19208 TT genotype had significantly higher amount of iron compared with those with the g.19208 CC and CT genotypes (P < 0.005). Sequence analysis showed that this locus might be part of an intron enhancer, potentially influencing pre‐mRNA splicing regulation. Similar significant associations of iron content were observed for three other SNPs. In conclusion, the SNPs identified may be used as DNA markers for muscle iron content.

Research support: PFIZER Animal Genetics Division

Grant Funding Source: PFIZER Animal Genetics Division
A TRUNCATED FORM OF THE SOYBEAN 7S GLOBULIN ALFA PRIME SUBUNIT UP‐REGULATES LDL RECEPTORS IN HEP G2 CELLS
Authors: Lovati Maria Rosa , Manzoni Cristina , Duranti Marcello , Morazzoni Paolo
Published: June 2021

7S soy globulin and its alfa prime subunit have been shown to positively modulate the LDL receptor activity both in vitro and in vivo. The aim of the study was to evaluate the effect of a truncated form of alfa prime subunit (t alfa prime), obtained by a biotechnological approach, on cell cholesterol homeostasis. Hep G2 cells were incubated in the presence/absence of the whole alfa prime subunit (3.5×10−6M) or the t alfa prime at concentration of 10−5 M and 10−6M. A dose‐dependent increase (P<0.05) in the up‐regulation of the LDL receptor was detected in cells exposed to t alfa prime versus that found in controls. Moreover, the LDL uptake (+ 185%) and degradation (+ 156%) of cells tested to the higher dose of t alfa prime (8×10−6M) was similar to that found in cells incubated with 1 M simvastatin. These results were confirmed by a dose‐dependent increase in the SREBP2, PCSK9 and LDL‐R mRNAs. Hep G2 cells exposed to t alfa prime for 24 h showed an increased uptake of fluorescent LDL versus both whole alfa prime and controls, as detected by fluorescente microscopy: the fuorescence intensity was proportional to the amount of LDL uptaked by the cells as confirmed by FACS analysis. These findings open new prospects in the studies aimed at identifying the regulatory peptide/s from soybean proteins and the mechanism/s involved in this biological response, in view of their potential utilization as nutraceutics.
Wolfberry Supplements Prevent the Development of Hepatic Steatosis
Authors: Lin Dingbo , Jiang Yu , Zhang Yunong , Ortiz Edlin , Medeiros Denis M.
Published: June 2021

Objective

To determine if wolfberry supplements prevent the development of hepatic steatosis.

Methods

Male C57BL/6J mice, at 6 weeks of age, were fed 45 kcal % fat diets (high fat diets) for up to 28 weeks (10 mice for each group). Two groups of mice had their diets supplemented with either 1 % or 5 % (w/w) wolfberry fruits; and there was a high fat diet control group without any added fruit. In addition, there was a group of mice fed 10 kcal % fat diets only as a low fat diet control. Body weight and food consumption were monitored weekly. Development of hepatic steatosis and cellular biochemical alterations were determined at 8, 18, and 28 weeks of dietary treatments. Western blotting was used to determined activation of AMP‐activated protein kinase (AMPK), sirtuin 1 (SIRT1), acetyl‐CoA carboxylase (ACC), and endoplasmic reticulum (ER) stress in the liver tissues.

Results

Mice fed high fat diets (45 kcal % fat) developed obesity and hepatic steatosis as early as 8 weeks of treatment. Wolfberry supplements, at both levels, completely prevented hepatic steatosis occurring, whereas it was present in high fat diet controls, but not in low fat diet controls. Wolfberry supplements activated AMPK, inhibited ACC, but SIRT1 level was not altered. Wolfberry addition prevented high fat diet‐triggered ER stress through inhibition of GRP78/BiP and protein kinase‐like endoplasmic reticulum kinase (PERK).

Conclusions

Wolfberry fruits prevent high fat diet‐induced hepatic steatosis most likely through a rebalance of cellular energy homeostasis, control of fatty acid synthesis, and diminishing cellular ER stress.

Support: National Institutes of Health COBRE Grant P20‐RR‐017686 to D. L.

Grant Funding Source: National Institutes of Health COBRE Grant P20‐RR‐017686
Preoperative carbohydrate loading in patients undergoing coronary artery bypass or spinal surgery
Authors: Tran Susan , Wolever Thomas M.S. , Errett Lee E. , Ahn Henry , Mazer C. David , Keith Mary
Published: June 2021

Surgery induces a state of insulin resistance (IR) which may be aggravated by current fasting practices. Oral preoperative carbohydrate (CHO) loading may reduce postoperative IR and subsequently complications. The current study was designed to determine whether CHO loading would blunt the development of postoperative IR, reduce preoperative discomfort and improve clinical outcomes in elective coronary artery bypass or spinal surgical patients. Thirty‐eight patients were randomized to receive a CHO supplement the evening before (100g CHO) and two hours prior to surgery (50g CHO) or fast for 12 hours preoperatively. Insulin sensitivity was measured using the short insulin tolerance test and homeostasis model assessment (HOMA). Patient discomfort was measured immediately before surgery using visual analog scales. Insulin sensitivity was not significantly different between groups. However, the treated group experienced a significantly smaller rise in glucose levels following surgery (p=0.03) and had higher postoperative HOMA‐β scores (p=0.02). Supplemented patients were also significantly less thirsty (p=0.01), hungry (p=0.04) and anxious (p=0.01) before surgery and experienced a significantly shorter hospital stay (p=0.008). CHO loading improved outcomes, warranting re‐evaluation of fasting practices in this population. This research was supported by a CIHR student fellowship.
Starch chemistry affects the kinetics of glucose and SCFA absorption, and insulin and incretin release in pigs
Authors: Regmi Prajwal R. , Matte J. Jacques , van Kempen Theo A. T. G. , Zijlstra Ruurd T.
Published: June 2021

The objective was to understand the role of starch chemistry on kinetics of glucose and SCFA absorption, and on insulin and incretin release. Four purified starches (crystallinity, 24 to 40%; granule size, 12 to 229 sq. μm; amylose, 0 to 80%; resistant starch, 1.9 to 70.2%; reflected by max. rate of in vitro digestion: from slow, 0.22; 0.38; 1.02; to rapid digestible, 1.92%/min) were included at 70% in diets fed to 4 porto‐arterial catheterized pigs (38.7 ± 1.7 kg BW). Slow vs. rapid digestible starch lowered (P<0.05) postprandial (PP) net portal appearance (NPA) of glucose 53%, insulin and C‐peptide (peak and 0.5 to 1 h) 55%, NPA glucose to insulin ratio (2 to 10 h) 71%, portal GIP (2 to 2.5 h) 81%, and GLP‐1 (1.5 to 2 h) 36%, and it increased (P<0.01) NPA of SCFA 196%. Incremental area under the curve (iAUC) of insulin NPA was linearly positively related (P<0.01) with iAUC of glucose (R2=0.49) and incretins NPA (R2=0.27) and iAUC of incretin NPA was similarly related with iAUC of glucose (R2=0.78) and SCFA NPA (R2=0.35) in a regression model. Addition of predicted gastric emptying in the model improved the relation of iAUC of insulin NPA with iAUC of incretins and glucose NPA (R2=0.86). Conclusion: slow digestible starch reduces glucose and insulin responses and increases SCFA absorption. Glucose absorption, incretin release, and gastric emptying appear important factors for insulin release.

Funding Source: ALMA, Provimi, Alberta Pulse Growers
Endothelial p120‐catenin regulation of leukocyte transmigration is not due to inhibition of RhoA
Authors: Alcaide Pilar , Newton Gale , Vincent Peter , Luscinskas Francis W
Published: June 2021

Leukocyte transendothelial migration (TEM) is a complex process involving cytoskeletal remodeling controlled by several signaling pathways including RhoGTPases. Previous studies have shown that VE‐Cadherin (VE‐Cad) forms a complex with α‐,β‐,γ‐, and p120‐catenins, and that during TEM, this VE‐cad complex disassociates to form a transient gap. p120‐catenin (p120) over expression stabilized VE‐cad surface expression and prevented leukocyte TEM. This process was dependent on changes in VE‐cad tyrosine phosphorylation. Based on reports that p120‐catenin overexpression in fibroblasts inhibits RhoA and activates Rac and Cdc42, we speculated that a similar process may occur in human endothelial cells (HEC) and was responsible for blocking TEM. HEC overexpressing p120GFP or Adv‐GFP were treated with α‐thrombin or medium, lysed, and assayed for RhoA, Rac and Cdc42 activity. Neither overexpression of p120 or GFP affected basal activity of these GTPases. Thrombin induced a significant increase in both GTP‐loaded Rho‐A and actin stress fibers in both GFP and p120GFP transduced HEC. Our data provide evidence that regulation of VE‐Cad gap formation and TEM by p120 does not involve inhibition of RhoA activity. Supported by NIH HL053993 & HL094706.
Bone morphogenetic protein signaling is essential for correct vascularization of lungs and kidneys
Authors: Yao Yucheng , Jumabay Medet , Wang Anthony , Bostrom Kristina I
Published: June 2021

Vascularization of growing organs is a highly coordinated process. Matrix Gla Protein (MGP) is expressed in lungs and kidneys during organ growth and inhibits bone morphogenetic protein (BMP)‐4 and ‐7, essential for both lung and kidney formation and angiogenesis. We hypothesized that BMP signaling is essential for correct organ vascularization. MGP deficient and MGP transgenic mice were used to study BMP signaling and vascularization in lungs and kidneys. Micro CT imaging showed a dramatic increase in vascular formation with evidence of abnormal arteriovenous connection in MGP deficient mice, whereas vascular growth was inhibited in MGP transgenic mice. Expression of activin‐like kinase receptor (ALK)1, ALK2, ALK5 and VEGF, known to be induced by BMP in endothelial cells, was significantly increased in MGP deficiency, but decreased when MGP was overexpressed. Unexpectedly, similar changes occurred in the type II epithelial lung cells and the mesenchymal kidney cells, suggesting that this system may coordinate vessel growth with the growth of organ‐specific elements. The levels of BMP‐4 and BMP‐7 did not significantly change, although BMP‐7 appeared to play a more important role in kidney vascularization. We conclude that timely inhibition of BMP‐4 and ‐7 by MGP in lungs and kidneys is essential for appropriate organ vascularization.

Research support: NIH/NHLBI, AHA.
An alternative step‐wise mechanism for arterial and venous differentiation in mammals
Authors: Wang Rong A. , Kim Yung Hae , Lindskog Henrik , Gallardo Salvador Guevara , Jelin Eric
Published: June 2021

Arterial and venous (AV) differentiation is critical for vascular homeostasis. To understand the mechanism of AV differentiation, we studied the developing dorsal aorta (DA) and cardinal vein (CV) pair. Using transgenic mice, we found that the primordial DA and CV assembled without Notch signaling. Furthermore, the primordial DA was composed of endothelial cells (ECs) lacking arterial markers, suggesting it forms before arterial specification. Later, the primordial DA and CV expressed both arterial and venous markers. We thus propose a model of mammalian AV differentiation, distinct from the current model, where primordial vessels emerge before AV specification, transiently harbor both arterial and venous ECs, and then mature into the ultimate arteries and veins with uniform AV identities.

This work was supported by NIH R01 HL075033 to R.A.W., and by a generous grant from the Foundation for Accelerated Vascular Research. This work was also supported in part by a Swedish Research Council Postdoctoral Fellowship to H.L, T32 HL007544 to S.G.G. and NIH F32 HL097400 to E.J.
MEF2 activity is required for maintenance of endothelial barrier function and vessel integrity
Authors: Schwarz John J , Adam Alejandro P , Herron Crystal R , Vincent Peter A
Published: June 2021

Transcription factors of the MEF2 family are critical regulators of the development and physiology of several organ systems. We are investigating their role in the endothelium by the combined endothelial‐specific deletion of Mef2c and global deletion of Mef2a. This results in hemorrhage and death during embryonic development, indicating that the MEF2s are required for vessel integrity. We explored the possibility that the MEF2s are critical for endothelial barrier function by blocking MEF2 activity in a mature monolayer of human dermal microvascular endothelial cells (HDMEC) with an adenovirus expressing a dominant negative MEF2 (DN‐MEF2). Expression of DN‐MEF2 decreased the barrier function of EC monolayers as assessed by changes in transendothelial resistance (TEER) beginning 30 hrs post infection and produced gaps in the endothelial junctions as assessed by immunofluorescence to ZO‐1 and VE‐cadherin. We also found that the thrombin‐induced increase in permeability was enhanced by DN‐MEF2 prior to the onset of increased basal permeability. These results demonstrate that the MEF2s play a role in the regulation of endothelial monolayer integrity.

RO1‐HL77870
Hepatocyte Nuclear Factor 4 alpha (HNF4α) is involved in regulation of hepatocyte proliferation
Authors: Apte Udayan , Bell Aaron , Walesky Chad , Edwards Genea , Wolfe Andy
Published: June 2021

HNF4α is the master regulator of hepatocyte differentiation and controls expression of a wide variety of hepatocyte‐specific genes. Here we report that HNF4α is involved in inhibiting hepatocyte proliferation. Decreased HNF4α expression was observed in hepatocyte specific integrin linked kinase knockout mice (ILK‐KO), which have sustained cell proliferation resulting in hepatomegaly. Following partial hepatectomy (PH), the ILK‐KO mice exhibited enhanced hepatocyte proliferation resulting in 60% higher liver mass as compared to their pre‐PH liver mass. The increased proliferation in ILK‐KO mice after PH was accompanied by further decrease in HNF4α expression. Further analysis revealed decrease in expression of HNF4α targets such as p21 and claudin1, which are involved in cell‐cycle regulation in ILK‐KO livers. Hepatocyte specific knockdown of HNF4α in HNF4α‐floxed mice using Cre recombinase carried by a adeno‐associated virus 8 (AAV‐8) vector resulted in induction of cell proliferation accompanied by decreased expression of p21 and claudin1. Over‐expression of rat HNF4α in JM1 cells resulted in decreased proliferation of these cells. Taken together, these data indicate that HNF4α plays an anti‐proliferative role in hepatocytes and may be involved in termination of liver regeneration.
Inhibition of RE‐1 silencing transcription factor (REST) inhibits survival and proliferation of primary hepatocytes under the influence of hepatocye growth factor (HGF) and epidermal growth factor (EGF)
Authors: Bhave Vishakha S. , Bowen William C. , Paranjpe Shirish G. , Donthamsetty Shashikiran , Michalopoulos George K.
Published: June 2021

The objective of the present work was to test the expression and role of REST in primary hepatocytes under the influence of growth factors HGF and EGF. REST (also known as neuron restriction silencing factor NRSF) has previously been shown to maintain self renewal and pluripotency in mouse embryonic stem cells by maintaining the expression of self renewal regulators like Oct3/4, Nanog, cMyc, and Klf4. Primary rat hepatocytes undergo dedifferentiation and proliferation in the presence of hepatocyte growth medium (containing HGF and EGF). Primary hepatocytes were cultured with or without HGF and EGF. Plates were harvested at 0, 2, 4, 6, 8, and 10 days for mRNA and protein. REST mRNA and protein were upregulated along with stem cell markers like Oct3/4, Nanog, cMyc, and Klf4 in the presence of HGF and EGF. When REST was inhibited in these hepatocytes using shRNA for REST, these hepatocytes did not proliferate and died as compared to cells treated with the shRNA of luciferase, suggesting that REST expression is important for survival and proliferation of primary hepatocytes under the influence of HGF and EGF. The expression of stem cell markers in the REST inhibited hepatocytes is yet to be determined. This work is supported by 5R01CA103958‐05 titled HGF and signaling pathways in hepatic tissue assembly.
S‐adenosylmethionine Down Regulates Blood Alcohol Level
Authors: Bardag‐Gorce Fawzia , Oliva Joan , Fong Stephanie , Wong Wesley , French Barbara A , Li Jun , French Samuel W
Published: June 2021

Alcohol consumption raises blood alcohol levels (BALs), and causes an increase in the enzymes that metabolize ethanol, primarily alcohol dehydrogenase (ADH), acetaldehyde dehydrogenase (ALDH), and cytochrome P450 (CYP2E1). Recently, s‐adenosylmethionine (SAMe) was observed to reduce acute BALs. The question is what is the mechanism involved in this reduction of BAL by SAMe feeding? To answer this question we investigated the changes in ethanol metabolizing enzymes and the epigenetic changes that regulate these changes in acute binge drinking and chronic drinking. In the chronic model, rats were fed ethanol and SAMe for 1 month using the intragastric tube feeding model. In the acute models, rats were fed a bolus containing ethanol with or without SAMe and were sacrificed at 3 or 12 hours after the bolus. Western blot analyses showed that SAMe significantly induced ADH levels in the 3h liver samples. However, SAMe did not affect the changes in ADH levels for the 12h acute experiment or in the chronic experiment. Since SAMe is a methyl donor, it was suspected that the ADH gene expression change was due to a histone modification. Dimethylated histone 3 lysine 4 (H3K4me2), a modification responsible for gene expression activation, was found to be significantly increased by SAMe in the acute experiments. These results correlate with the low BAL found in the acute experiment and support the concept that SAMe is a promising modulator of gene expression caused by high levels of ethanol. Supported by NIH/NIAAA 8116.
Mathematical modeling used to understand vascular remodeling
Authors: Pries Axel R. , Secomb Timothy W
Published: June 2021

Vascular adaptation to metabolic and hemodynamic signals is a dynamic process defining vascular structure and function. While many components of these reactions, e.g. vascular responses to reduced oxygen or increased shear stress have been investigated in experimentally, exclusive biological approaches have some limitations: long term structural adaptation is difficult to investigate and most experiments are focussed at testing a given cause‐effect hypothesis. Mathematical modelling can complement biological experiments and result in additional insight. For vascular remodeling of vessel diameter and vessel wall mass, a minimal set of relevant signals can be defined including oxygen partial pressure, shear stress and circumferential stress. Using this approach and comparing experimental distributions of diameter and blood flow with model predictions, a number of hypotheses could be derived: A single set of response characteristics governs adaptation of all microvessels. Information transfer along vessels (conduction) is necessary to maintain functionally adequate perfusion. Inadequate distribution of blood and oxygen in tumor microcirculation results from compromised conduction. Spatial heterogeneity of perfusion and demand results from adaptation and topological network heterogeneity. Oxygen sensing for structural adaptation is located in the vascular wall.
Aging‐induced collateral impairment: role of arterial rarefaction, decreased eNOS expression/signaling, and increased susceptibility of endothelial cells to apoptosis
Authors: Epstein Stephen Edward , Wang Jinsong , Peng XinZhi , Zhuang Zhenwu , Simons Michael , Xue Zhenyi , Burnett Mary Susan
Published: June 2021

Despite positive animal studies, clinical angiogenesis trial outcomes have been disappointing. Because 1) aging impairs ischemia‐induced collaterogenesis in animals, and 2) patients targeted for angiogenesis therapy are older, we determined whether aging‐induced changes in collateral phenotype could contribute to the disappointing clinical results.

Objective

To determine a) whether aging alters collateral phenotype such that they are more resistant to therapeutic interventions and, if so, b) what are the contributing molecular mechanisms.

Methods and Results

Micro‐computed tomography (MicroCT) was used to assess vessel phenotype in young (4 month) and old (20 month) wildtype C57 mice under baseline conditions. Old mice had approximately 60% fewer pre‐existing arterioles ≤25μm in the calf and thigh, approximately 50% fewer arterioles >25μm in the calf, and decreased baseline endothelial nitric oxide synthase (eNOS) protein and phosphorylation at serine‐1177 (indicating both decreased eNOS expression and signaling) than young mice. To determine if this association reflected causality, we examined vessel phenotype in eNOS knockout (KO) mice; young eNOS KO mice exhibited significantly fewer arterioles than young wild‐type mice, similar to the findings in old wild‐type mice. Interestingly, endothelial cells obtained from older mice a) exhibited decreased eNOS protein and serine‐117 phosphorylation, and b) were more sensitive to an apoptotic stimulus, findings that may contribute mechanistically to vessel dropout.

Conclusions

Aging leads to arteriolar rarefaction, an effect contributed to by decreased eNOS expression and signaling, which predisposes endothelial cells to undergo apoptosis. This microvasculature rarefaction may importantly contribute to the thus‐far disappointing results of clinical angiogenesis trials.

This work was supported by NIH RO1 HL085003‐01A2.
Clinical cases based on body donors as a method to enhance radiology education and clinical relevance for gross anatomy
Authors: Gest Thomas Richard , Francois Webster
Published: June 2021

We have developed a novel method of introducing radiology education and clinical relevance into a gross anatomy course. Each summer before the beginning of gross anatomy for the first year medical students, we collect the medical histories of the body donors that will be used in the dissection labs. This past summer, we also collected whole body CT scans of each donor. We converted these scans to QuickTime movies for use on our course website (http://anatomy.med.umich.edu). These whole body CT scan movies were displayed using a novel web interface that is extremely user friendly and interactive. Selected movies were associated with relevant clinical anatomy teaching points as well as clinically oriented quiz questions. The clinical teaching points correlate with and emphasize key anatomical knowledge within the M1 curriculum. A web‐based evaluation form was used to collect student opinion on the effectiveness of this method of presenting radiology data sets in correlation with dissection of the bodies from which these data sets come. This web‐based presentation of whole body CT data correlated with whole body anatomical dissection provides a unique method to introduce first year medical students to radiology and clinical relevance of anatomy.
Evolution of an Anatomy Based Integrated Curriculum
Authors: Klement Brenda J. , Paulsen Douglas F. , Wineski Lawrence E.
Published: June 2021

A current trend in medical education is weaving basic science course content into an integrated curriculum. Our anatomy course, with regional dissection at its core, serves as the backbone for integrating our entire first year medical curriculum. The second phase of this faculty‐led task has centered upon a re‐assignment of course boundaries. Historical courses have been interwoven into a curriculum now composed of four courses, each spanning a quarter of the academic year. These courses are equal in credit hours and approximate time allotment and anatomy remains the centerpiece of each. Establishment of a curriculum management team, including course directors, subject specialists and a curriculum director, has resulted in smooth, efficient and transparent curriculum administration. Use of standardized subject exams has been preserved, but debate about how and in which course to apply the scores have resulted in a complex grading system. Electronic exam delivery has simplified the entire exam process and made course management easier. Histology lab questions are included in the electronic exams, but the format of the gross anatomy practical exam and quizzes has been maintained with minor adjustments for station numbers. We expect the curriculum to continue evolving toward full integration, retaining full regional dissection as a core element. Supported in part by NIH PO3 1B040107 and G12‐RR03034.
Beyond the bones: Reconstructing soft tissue anatomy of our ancestors
Authors: Laitman Jeffrey Todd , Marquez Samuel , Pagano Anthony Santino , Reidenberg Joy S
Published: June 2021

Anatomical reconstruction of human ancestors has largely focused upon piecing together osteological or dental fossil fragments. Indeed, the majority of studies charting evolutionary change in human anatomy have focused upon such hard‐tissue cranial or postcranial interpretations with assessments of soft‐tissue anatomy offered only infrequently. Here we present methods of reconstruction of soft‐tissue anatomy of fossil hominins ranging from early Plio‐Pleistocene australopiths to the more recent Neanderthals. Examples will be provided from our ongoing research on the head and neck – particularly the upper respiratory and digestive tracts – integrating advances from studies on the comparative and developmental biology of a range of living mammals. Such approaches have enabled us to begin to extract an appreciation of core functions such as breathing, swallowing, aeration, pressure‐control and vocalization potentials. While soft‐tissue reconstructions and functional interpretations are inherently more difficult than bony assessments, they are an essential component to gaining insight into the anatomy and behaviors of human ancestors and, indeed, our evolutionary history.