bluuebunny/crossref_metadata_2025 huggingface dataset:
Developmental expression of carbonic anhydrase II in the extraembryonic membranes of oviparous and viviparous snakes
Authors: Ecay Tom W , Fregoso Santiago , Khambaty Maleka , Stewart James R
Published: June 2021

Oviparous reptile embryos receive a significant proportion of their calcium from the eggshell. For chickens, ≥ 80% of hatchling calcium originates from the shell while for oviparous snakes the shell accounts for 20–25% of hatchling calcium. The chick chorioallantois, which lies just beneath the eggshell, expresses carbonic anhydrase II (CAII) late in development. CAII is hypothesized to provide protons that are pumped out of the chorionic epithelium to acidify the inner surface of the shell, dissolving calcium carbonate and liberating calcium ions for transport to the embryo. Using immunoblotting, we determined the pattern of chorioallantoic CAII expression during the development of an oviparous (Pantherophis guttatus) and viviparous (Virginia striatula) snake to test the hypotheses that 1) oviparous snakes express a mechanism similar to chickens for dissolving shell calcium and 2) CAII is not expressed placental calcium transport in viviparous snakes. In P. guttatus, chorioallantois expression of CAII increases late in development coincident with shell calcium transport to the snake embryo, supporting hypothesis 1. In V. striatula, chorioallantoic expression of CAII also increases coincident with placental calcium transport late in development suggesting that CAII may be involved in additional chorioallantoic functions such as gas exchange and/or acid‐base balance. Supported by NSF grant IOB‐06515695.
Effects of body size and development on the hypoxia response of the caterpillar, Manduca sexta
Authors: Greenlee Kendra J , Eubanks Haleigh , Kirkton Scott D , Lee Wah‐Keat
Published: June 2021

Manduca sexta larvae tolerate hypoxia, with critical PO2s of 5 kPa. In contrast, the largest caterpillars, which can be 10,000 times larger than hatchlings, have critical PO2s as high as 15 kPa. To better understand the hypoxia response, we exposed caterpillars (range 0.006 to 6 g) to 21, 5, 3, 2, 1 or 0% O2 and measured CO2 emission. In hypoxia, the largest caterpillars (> 1 g) exhibited rhythmic body contractions, which coincided with CO2 emission peaks. To verify that these were respiratory movements and to determine how size affects the hypoxia response, we used synchrotron x‐ray imaging in conjunction with high‐speed respirometry. We exposed caterpillars (range 0.006 to 6 g) to 21, 5, 3, 2, 1 or 0% oxygen and concurrently measured CO2 emission and external and internal respiratory movements. In normoxia no caterpillars showed tracheal compressions. For small caterpillars, no body contractions or tracheal compressions were observed at any PO2. However, large caterpillars (> 1 g) in hypoxia had body contractions that correlated with CO2 emission and tracheal compressions, suggesting that larger caterpillars modulate breathing. Tracheal compression frequency did not scale with body mass in large caterpillars (>1 g), suggesting that there is a threshold body size for this behavior. This work was supported in part by NDSU, NSF EPSCoR #EPS‐00447679, NIH 2P20RR015566 and DOE W‐31‐109‐ENG‐38.
Calcium‐dependent regulation of proton signaling during a rhythmic behavior in C. elegans
Authors: Allman Erik , Nehrke Keith
Published: June 2021

In C. elegans, rhythmic defecation behavior is controlled by oscillatory Ca2+ signaling in the intestine. The first motor step in defecation requires the intestinal Na+/H+ exchanger NHX‐7, which extrudes protons through the basolateral membrane. Protons are a direct ligand for the PBO‐5 receptor on the overlying body wall muscle, and transient acidification signals the muscles to contract. This model represents the first demonstration that Na+/H+ exchangers can use protons to transmit information between cells. To test whether NHX‐7 is regulated by Ca2+ signaling, we mutated predicted Ca2+ regulatory motifs in the nhx‐7 coding region, including those for calmodulin and phosphatidylinositol 4,5‐bisphosphate binding as well as modification by various Ca2+‐activated protein kinases, then tested their ability to complement an nhx‐7(ok585) null allele. In addition, dynamic fluorescent imaging of a genetically‐encoded pH biosensor was used in these worms to measure the extent of acidification occurring between the posterior intestine and muscle cells during defecation. Finally, recombinant wildtype and mutant NHX‐7 activity was measured in tissue culture cells using conventional pharmacology and physiologic techniques. The results of these experiments provide an integrated perspective of Ca2+ and proton signaling during a model rhythmic behavior. Supported by NSF IOS0919848 (K.N.)
Designing a PBL curriculum that enhances education opportunities for general medical practitioners in Mozambique
Authors: Walker Elizabeth Reed , Billings Heather , Gomes Aurelio , Inroga Monica , Pearson John
Published: June 2021

The Catholic University of Mozambique (UCM), a private, not‐for‐profit institution serving central and northern Mozambique, established the Faculty of Medicine in Beira, Sofala Province in 2000. The first class of physicians graduated in 2007. The curriculum is based on local epidemiological profiles, and taught using problem‐based learning (PBL) methods. The mentors for PBL groups include basic science faculty and medical clinicians from the Ministry of Health Central Hospital in Beira. Quality assurance has been one of the most important concerns. Anatomy education was identified as an area of particular concern for quality assurance. To address this concern, a survey of procedures performed, complication rates, confidence in performing procedures, and self‐ratings of adequacy of anatomical background for learning new procedures were distributed to UCM graduates in district hospitals. Results are compared with surveys of physicians graduated from the established public university, Universidade Eduardo Mondlane, in Maputo, which uses a traditional lecture and laboratory format for medical education. Based on the survey results, new lessons will be prepared to address any identified weaknesses in medical education at UCM. This work was funded by Higher Education for Development: Africa ‐ U.S. Higher Education Initiative Planning Grant (AEG‐A‐00‐05‐00007‐00) sponsored by USAID.
eMentoring for Diversity in the Biosciences
Authors: Porush David , Elekonich Michelle
Published: June 2021

MentorNet (www.mentornet.net) is a 12‐yr‐old nonprofit organization devoted to helping women and minorities in science and engineering at 100 campuses achieve their career goals. Our vision is a level playing field for all talented students and a diversified global workforce in these most crucial fields. We provide a Web‐based program, refined by years of research and study (funded by NSF and others), that matches proteges with mentors and guides their one‐on‐one relationship for an extended period. We track data on our participants very closely and have recently seen an upsurge in students in the biosciences.

In this presentation, we will describe how the program works in exemplary fashion at one institution ‐ in Las Vegas; report our findings about the bioscience ementoring to date, discuss their implications, and solicit feedback about how we can further refine and adapt our program to serve the needs of bioscience students and professions.
Para‐aminobenzoic acid is a coenzyme Q biosynthetic precursor in Saccharomyces cerevisiae
Authors: Marbois Beth Noelle , Choi Samuel , Nguyen Theresa , Hyman Kyle , Hirano Kathleen , Clarke Catherine
Published: June 2021

Respiratory electron transport in the plasma membrane of prokaryotes and in the inner mitochondrial membrane of eukaryotes is supported by the crucial lipid component, ubiquinone (coenzyme Q or Q). Qn is composed of a fully substituted benzoquinone ring and a polyisoprene tail of n units. The best‐characterized ring precursor, 4‐hydroxybenozoate (4HB), is derived from the chorismate biosynthetic pathway. Extensive work has shown that the ring carbons of 4HB are incorporated into Q6 in yeast, under the activity of an enzyme complex found in the yeast mitochondrial matrix. However, the direct precursor compounds and enzymatic steps for the generation of 4HB in yeast are unknown. Our recent findings show that para‐aminobenzoic acid (pABA) is also a precursor for Q biosynthesis. In yeast pABA is synthesized from chorismate in two steps: Abz1 amidates chorismate to form 4‐deoxyaminochorismate, and Abz2 is a lyase that forms pABA. Here we show that the production of a prenylated form of pABA is dependent on the presence of the ABZ1 gene. We also demonstrate by LC‐MSMS analyses that yeast incubated with stable isotope forms of [13C6‐ring]‐pABA or [13C6‐ring]‐4HB generate [13C6]‐coenzyme Q6. These results identify a novel biosynthetic pathway for the production of Q in yeast. This research was supported by grants from the NIH GM 45952, NSF MCB‐0919609, and by a grant S10RR024605 from the National Center for Research Resources.
A Sliding Scale Governs Mismatch Recognition and Initiation of DNA Mismatch Repair
Authors: Hingorani Manju , Zhai Jie
Published: June 2021

DNA mismatch repair (MMR) maintains genome integrity by correcting base pair errors and triggering cell cycle checkpoints following DNA damage. It follows that MMR proteins are critical for suppressing mutagenesis and defects in their function are linked to cancer. The challenging task of finding rare aberrant sites in DNA is performed by MutS proteins, which recognize mismatches/lesions in DNA and initiate a response. To understand the mechanism of action of MutS, we monitored S. cerevisiae MutSα (Msh2‐6) binding to DNA in real time and measured transient interactions that govern its search for target sites. We found that Msh2‐6 binds a multitude of sites at similar high rates (kON=107 M−1s−1), but releases them at rates that vary by 100‐fold; e.g., kOFF for G:T or O6‐MeG:T is 0.015 s−1 (t1/2=46 s), while kOFF for +3T insertion is 2 s−1 (t1/2=0.34 s). By tracking Msh2‐6 movement we found that the protein slides on DNA making rapid contact with bases, and the lifetimes of resulting Msh2‐6•DNA complexes determine their selection as target sites for MMR. Thus, the long‐lived G:T complex effectively stabilizes Msh2‐6 in an ATP‐bound form that signals MMR, whereas the short‐lived +3T complex has little effect on ATP hydrolysis. Our kinetic data reveal that Msh2‐6 literally uses a ‘sliding scale’ to distinguish target sites, and offer an underlying basis for the bias in MMR reported by previous in vivo studies. Funding: NSF.
Amino acid nutrition in fetal and neonatal growth: from animal studies to clinical applications
Authors: Wu Guoyao
Published: June 2021

Studies of porcine milk composition over 18 years ago created a new direction of amino acid research. Specifically, the discovery of arginine (Arg) deficiency in sow milk led to the identification of glutamine and proline as the major substrates for Arg synthesis in piglets. Subsequent work resulted in the recognition that Arg is deficient in preterm infants with necrotizing enterocolitis and that its supplementation can ameliorate the gut disease. Further research on the ontogeny of Arg‐synthetic enzymes in the porcine intestine led to the discovery that the Arg family of amino acids is unusually abundant in allantoic fluids of swine and sheep during early gestation when placental growth is most rapid. This novel observation provided a strong basis for the effective use of Arg to improve embryonic/fetal survival and ameliorate intrauterine growth restriction in mammals (including pigs, sheep and humans) via enhancing NO‐mediated blood flow. Additional work to elucidate the underlying mechanisms led to another discovery that Arg reduces adiposity in pigs, sheep and rats. Notably, this knowledge has been translated into the use of Arg to promote white‐fat loss and improve insulin sensitivity in obese patients with type‐2 diabetes mellitus. Thus, animal models play an important role in developing new means to prevent and treat a wide array of major human diseases. Supported by NIH, USDA, AHA, and TAMU.
Urate Responsive MarR Homolog from Agrobacterium tumefaciens
Authors: Perera Inoka Chinthana , Grove Anne
Published: June 2021

MarR family transcriptional regulators are extensively studied for their involvement in modulating a vast number of metabolic and response pathways in bacteria and archaea. The natural ligands for many of the ligand responsive homologs of this family are elusive due to their low affinity or broad spectrum of selectivity. We have previously identified urate to be the natural ligand for HucR, a MarR homolog in Deinococcus radiodurans, and identified amino acid residues involved in binding of urate and the mechanism of eliciting DNA binding antagonism. Sequence analysis shows that a subset of MarR homologs conserves these residues in an all‐or‐none fashion suggesting that they would accept urate as their ligand. Using Agrobacterium tumefaciens‐encoded PecS as a model we show that these homologs specifically interact with urate and exhibit attenuated DNA binding as a result. PecS binds with sub‐nanomolar affinity to the intergenic region between pecS and pecM genes as a dimer of dimers on the same face of DNA and addition of urate dissociates them from the cognate DNA while allowing the transcription of both genes. Urate is produced as a byproduct of oxidative burst in plant immunity against invading bacteria. PecS response to urate may result in an upregulation of defence mechanisms and secretion of beneficial antioxidants to protect pathogenic bacteria. This work is supported by NSF (MCB‐0744240).
Vitamin D/calcium‐mediated apoptosis in cancer cells and adipocytes
Authors: Sergeev Igor N
Published: June 2021

1,25(OH)2D3 (1,25D) regulates variety of signaling pathways via intracellular Ca2+. Modulating apoptosis is emerging as a strategy for treatment and prevention of cancer and obesity. Cellular Ca2+ has been implicated in triggering apoptosis, however vitamin D/Ca2+‐dependent targets involved in apoptotic signaling have not been identified. We investigated mechanisms of 1,25D‐induced Ca2+ signaling and Ca2+‐mediated apoptosis in cancer cells and adipocytes. The results obtained demonstrate that 1,25D regulates Ca2+ entry from the extracellular space, Ca2+ mobilization from intracellular stores and intracellular Ca2+buffering. We have also shown that that the apoptotic Ca2+ signal represents a sustained increase in [Ca2+]i reaching elevated, but not cytotoxic levels. The apoptotic Ca2+ signal induced by 1,25D in breast cancer cells and mature adipocytes is associated with activation of Ca2+‐dependent μ‐calpain and Ca2+/calpain‐dependent caspase‐12. Activation of these proteases appears to be sufficient for execution of apoptosis. Normal mammary epithelial cells are resistant to induction of apoptosis with 1,25D due to their large Ca2+ buffering capacity. These results indicate that 1,25D‐induced cellular Ca2+ signal can act as an apoptotic initiator that directly recruits Ca2+‐dependent apoptotic effectors capable of executing apoptosis. Supported by USDA 2009‐35200‐05008 and SD00H325.
Changes in vitamin D status of female Soldiers during basic combat training
Authors: Andersen Nancy Ellen , Karl J. Philip , Diaz Jennifer E , Cable Sonya J , Williams Kelly W , Rood Jennifer C , Young Andrew J , Lieberman Harris R , McClung James P
Published: June 2021

Vitamin D is an essential nutrient for maintaining bone health. Recent data suggest that changes in vitamin D status might influence stress fracture prevalence. Although stress fracture is considered a health risk for Soldiers undergoing military training, no study has documented vitamin D status in that population. This longitudinal study aimed to determine the effects of basic combat training (BCT) on 25‐hydroxyvitamin D (25(OH)D) and parathyroid hormone (PTH) levels in female Soldiers. Serum 25(OH)D and PTH were measured in 74 fasted Soldier volunteers before and after a 9 wk BCT course between August and October in Columbia, SC. In the total study population, 25(OH)D levels decreased (72.9 ± 30.0 vs 63.3 ± 19.8 nmol/L, p<0.05) and PTH levels increased ([mean ± SD] 36.2 ± 15.8 vs 47.5 ± 21.2 pg/mL, p<0.05) during BCT. Ethnicity affected changes in vitamin D status (group‐by‐time interaction, p<0.05); 25(OH)D decreased by 10 ± 27% (89.23 ± 29.3 vs 74.87 ± 17.0, p<0.05) in non‐Hispanic whites, 15 ± 18% (74.07 ± 15.1 vs 63.27 ± 14.2, p<0.05) in Hispanic whites, but did not change in non‐Hispanic blacks. Ethnicity did not affect BCT‐induced changes in PTH. These data indicate that vitamin D status in female Soldiers may decline during military training. Future studies should ascertain whether this decline affects bone health. Research supported by MRMC.
Hormonal and body composition changes associated with amelioration of diet‐induced obesity by deoxynivalenol in the mouse
Authors: Hattori Kazuo , Flannery Brenna , Amuzie Chidoze , Pestka James
Published: June 2021

Consumption of the mycotoxin deoxynivalenol (DON) ameliorates weight gain in diet‐induced obese (DIO) mice. DON's therapeutic effects in DIO mice were related to food intake, body fat mass, lean weight and selected obesity‐related plasma hormones. Female B6C3F1 mice were fed 10% kcal control (CON) diet or 45 and 60% kcal high fat diets (HFD). After obesity induction (94 d), half of each high fat group was continued on same diet and the other half fed HFD containing 10 ppm DON from day 94 to 148. HFD‐DON‐fed mouse body weights decreased rapidly to that of CON by day 105 and maintained at that level thereafter. Food intake by the HFD‐DON‐fed groups significantly decreased as compared to HFD from day 98 and 101 concurrently with robust decreases in body weight. MRI data revealed that fat mass and body fat percentages of the HFD‐DON‐fed mice rapidly decreased to those of CON while reduced lean weights were detectable day 122. HFD‐DON‐fed mice had decreased plasma levels of insulin‐like growth factor 1 (IGF‐1) compared to HFD. HFD‐fed mice exhibited increases in plasma insulin and leptin which were suppressed in HFD‐DON‐fed mice. Accordingly, DON‐induced body weight reduction in DIO mice is accompanied by decreased body fat mass and lean weight. These effects correspond to both decreased food intake and marked reductions in plasma IGF‐1, insulin and leptin. Supported by USDA Agreement No. 59‐0790‐4‐119/PHS Grant ES03358.
Discretionary energy, added sugars, and beverage choice by U.S. adults: Results from What We Eat in America (WWEIA)/NHANES 2005–2006
Authors: Sebastian Rhonda , Enns Cecilia Wilkinson , Goldman Joseph , Moshfegh Alanna
Published: June 2021

This study sought to determine associations between compliance with selected recommendations and beverage choices of U.S. adults. A nationally representative sample of men and women age >18 y (n = 4,405) with one complete 24‐hour dietary recall in What We Eat in America/NHANES 2005–2006 was analyzed. Respondents were grouped based on how closely their intakes met recommendations for discretionary energy (MyPyramid) and added sugars (American Heart Association). Regression procedures were used to detect associations between compliance and beverage intakes. For both men and women, significant inverse associations (p <0.01) were found between discretionary energy compliance and (a) intakes of regular soft drinks and beer, and (b) the likelihood of drinking those beverages. Compared to adults with low added sugars compliance, those with high compliance had lower mean intakes of sugar‐sweetened beverages and were more likely to consume 100% juice, low‐calorie drinks, water, and tea without caloric additions. High compliers to both recommendations who did report energy‐dense, nutrient‐poor beverages consumed lesser amounts than did low compliers. Beverage choices of adults adhering most closely to national recommendations for discretionary energy and added sugars may be characterized as lower in calories and/or higher in nutrient content. Funding source: ARS, USDA.
Association of Bone Mineral Density with Lean Mass and Fat Mass
Authors: Hooshmand Shirin , Chai Sheau C. , Saadat Raz L. , Arjmandi Bahram H.
Published: June 2021

Obese individuals hold an increased risk of chronic diseases such as CVD. We reported that a relationship exists between BMI and indices of CVD risk in postmenopausal women. To investigate the relationship between BMI and chronic diseases, we measured CRP level, a marker of inflammation, in 132 postmenopausal women. Participants were divided into three groups based on their BMI values: 1) normal (18.5–24.9); 2) overweight (25–29.9); and 3) obese (>30). BMI was positively correlated with CRP. In addition, overweight and obese individuals had higher serum levels of CRP compared to individuals with normal BMI. In contrast to existing relationship of higher BMI and higher incidence of chronic diseases, studies have shown that osteoporosis is the only chronic disease that has negative correlation with BMI. To investigate this relation, we evaluated the correlation between BMI and BMD in this population. BMI was positively correlated with BMD which means a negative correlation with osteoporosis; however, when we examined the correlation between BMD and components of body composition including fat mass and lean mass; BMD was highly correlated with lean mass but not with fat mass. Although these data supports the notion that individuals with higher BMI have lower risk of osteoporosis, break down of body composition clearly demonstrate that the credit for this correlation should be given to lean mass and not fat mass.

Grant Funding Source: USDA
INFANT FEEDING PATTERNS OF MULTIETHNIC MOTHERS
Authors: Daida Yihe , Novotny Rachel
Published: June 2021

Breastfeeding is the optimal method of infant feeding and many factors influence infant feeding methods. The purpose of this study is to describe how multiethnic mothers in Hawaii fed their infants, and factors associated with breastfeeding. This abstract utilizes cross‐sectional data from the Female Adolescent Maturation (FAM) Study, where healthy Asian and White adolescents were selected from the Kaiser Permanente database. Participants’ mothers completed a questionnaire on how they fed the FAM participants. Feeding patterns (breastfed yes/no, duration and type of feeding), birth information, parental education and mother's ethnicities were reported by participants’ mothers. Mother's ethnicity in percentage, as well as classification into Asian, White and Other categories were used for analyses. Birth weight was significantly different between the ethnic groups. Asians had the highest mean years of education and more Asians initiated breastfeeding at birth, though Whites breastfed for the longest duration. After controlling for parental education and mother's age at delivery, mother's education, birth weight and Other ethnicity were positively associated with breastfeeding duration. Gestational age was inversely associated with duration of breastfeeding (R2=27.8%). Further investigation is needed to understand how maternal ethnicity and education influence infant feeding practices. [Supported by USDA #9900700 & NIH/NCRR/RCMI Award# P20RR11091]
Asian ancestry and birth length are associated with height among females during adolescence
Authors: Oshiro Caryn , Grove John , Novotny Rachel
Published: June 2021

Greater rate of height gain during adolescence and greater attained height in adulthood have been identified as risk factors for later breast cancer risk. The Female Adolescent Maturation studies (FAM1, 2, 3) examined adolescent diet, physical activity, maturation and their relationship with body size. We examined the association of early life factors with mean height gain between FAM1 to 2 (9–16yrs, n=99), and FAM2 to 3 (11–19yrs, n=63) and attained height in girls at FAM3 (13–19yrs, n = 63). Attained height was defined as height in girls at FAM3. Information on birth parameters (weight, length, gestational age) and type of infant feeding were obtained via questionnaire. Mean height gain was 4.66 cm/yr (FAM1 to 2) and 2.4 cm/yr (FAM2 to 3). Although mean height gain was not significantly different between Asian and white ancestral groups, mean attained height was different (p = 0.0002). Lower % Asian ancestry predicted greater FAM 2 to 3 height gain (p=0.02, R= 0.52) adjusting for age and birth parameters. Attained height was regressed on age, % Asian ancestry, birth parameters, and age at menarche. Longer birth length was associated with greater attained height in girls at FAM3 (p=0.002, R=0.33). No effect of feeding or gestational age was observed on height gain or attained height. In conclusion, birth length and Asian ancestry are associated with attained height and gain in height during adolescence, respectively. USDA Grant # 99‐00700; NIH/NCRR/RCMI P20 RR119091 award; CRCH Developmental Funds; DOD Grant # BC032028
TNF‐α induced alterations in the Wnt signaling cascade: a potential mechanism for obesity‐associated colorectal tumorigenesis
Authors: Brooks Ryan S , Ciappio Eric D , Bennett Grace , Crott Jimmy W , Mason Joel B , Liu Zhenhua
Published: June 2021

Epidemiological studies consistently implicate obesity as an important risk factor for several types of cancer, and the data is particularly compelling for colorectal cancer. However, the underlying mechanism is not defined. This study investigated whether Wnt‐signaling, a critical pathway in colorectal carcinogenesis, is upregulated by the inflammatory cytokine, TNF‐α, which has been found to be elevated in obesity. Obesity was induced in C57BL6 mice using a high‐fat diet (60% kcal). TNF‐α protein in the colon, determined by ex vivo culture of the colon followed by ELISA of the media, was significantly elevated (p<0.05) in obese mice. Phospho‐GSK3β, which is an important intermediary in Wnt signaling and which has been reported to be induced by TNF‐α, was elevated by immunohistochemistry in the colonic mucosa of obese mice. Significant elevations of β‐catenin protein as well as increased c‐myc mRNA were evident in the colonic mucosa of the obese mice (p<0.05), and are also consistent with Wnt activation. These results demonstrate that obesity elevates colonic levels of TNF‐α and provide evidence that it may activate Wnt‐signaling in that organ. (This material is based on work supported by the USDA under agreement no. 58‐1950‐7‐707 and by the Prevent Cancer Foundation)
Sex differences in plasma amino acid and fat free mass responses to military training
Authors: Pasiakos Stefan M , Margolis Lee M , Karl J Philip , Rood Jennifer C , Cable Sonya J , Williams Kelly W , Young Andrew J , McClung James P
Published: June 2021

Diet, exercise, and energy status influence amino acid (AA) availability and contribute to the regulation of skeletal muscle mass. Whether altering these factors through training influence plasma AA levels and the maintenance of muscle mass in young adults has not been determined. This study assessed body composition and plasma AA levels in US Army recruits (n=209, 118 males, 91 females, 23 ± 5 yr) at baseline and every three weeks during basic combat training (BCT). Body weight decreased in men but remained stable in women during BCT (sex‐by‐time interaction, P < 0.05). Fifty‐eight percent of recruits gained fat free mass (FFM) during BCT, with more (P < 0.05) females (88%) gaining FFM then males (36%). Total plasma AA levels increased (P < 0.05) during BCT, with greater (P < 0.05) increases observed in females (17%) then in males (4%). Essential amino acids (EAA) and branched‐chain amino acids (BCAA) levels were increased (P < 0.05) in females but did not change in males (sex‐by‐time interaction, P < 0.05). Independent of sex, changes in EAA and individual BCAA levels from baseline were associated (P < 0.05) with changes in FFM, with greater (P < 0.05) increases in AA concentrations observed for those who gained FFM. This data demonstrates the differential FFM and plasma AA responses to military training in males and females. Supported by USAMRMC.
Effect of maternal methyl diet on epigenetic changes and mammary carcinogenesis in offspring
Authors: Bae Sajin , Cho Kyongshin , Mabasa Lawrence , Walters Mark William , Park Chung S
Published: June 2021

Maternal nutrition influences the offspring's growth and metabolism while also affecting the susceptibility to diet‐related diseases such as cancer in adulthood. Lipotropes (choline, methionine, folic acid, and vitamin B12) play a role in DNA methylation, an epigenetic mechanism controlling the expression of genes involved in cell growth and metabolism. We studied the effects of a maternal lipotrope‐additive diet (LAD) on epigenetic changes and mammary cancer risk in female rat offspring. Dams were fed either a control diet (CD) or LAD during gestation and lactation. Their female offspring were weaned onto the CD and used for: 1) analysis of DNA methylation and gene expression in mammary tissues, and 2) a mammary carcinogenesis experiment using nitrosomethylurea. We observed a significant increase of 22% in global DNA methylation and a tendency toward decreased mRNA expression of the DNA methyltransferase1 gene in the LAD group. The offspring of the LAD‐fed dams also showed an increased latency period of 17%, along with decreased tumor incidence (27%), tumor numbers (57%), and tumor volume (33%). Our study suggests in utero and early postnatal exposure to LAD increases global DNA methylation in mammary glands, while also reducing mammary tumorigenesis. Future studies will be required to establish the detailed mechanisms responsible. Supported in part by a US Department of Defense grant.

Grant Funding Source : U.S. Department of Defense
Influence of consumption of allyl isothiocyanate or cabbage and mustard on DNA integrity in humans
Authors: Charron Craig S. , Clevidence Beverly A. , Albaugh George P. , Kramer Matthew , Vinyard Bryan T. , Milner John A. , Novotny Janet A.
Published: June 2021

Allyl isothiocyanate (AITC), which is derived from Brassica vegetables, is associated with anti‐cancer effects, though much evidence is from cell studies. A feeding study was conducted to investigate the effect of AITC on DNA integrity in vivo. Adults (n=46) consumed AITC, AITC‐rich foods (cabbage and mustard (C/M)), or a control diet for 10 d each in a crossover design. Volunteers were genotyped for the deleted or functional alleles of GSTM1 and GSTT1, and SNPs Asp312Asn and Lys751Gln in the DNA repair gene XPD. Ten day intake of neither AITC nor C/M resulted in significant differences in DNA strand breaks in peripheral blood mononuclear cells (LSmean % DNA in tail ± SEM: 4.8±0.6 for control, 5.7±0.7 for AITC, 5.3±0.6 for C/M). However, both AITC and C/M increased DNA strand breaks 3 h post‐consumption (%DNA in tail: 3.2±0.7 for control, 8.3±1.7 for AITC, 8.0±1.7 for C/M), and this difference disappeared at 6 h (4.2±0.9 for control, 5.7±1.2 for AITC, 5.5±1.2 for C/M). Genotypes for GSTM1, GSTT1, and XPD were not associated with treatment effects. In summary, DNA damage appeared to be induced in the short term by AITC and AITC‐rich products, but that damage disappeared quickly. Funded by USDA and NCI.
Regulatory effects of curcumin on FOXO3a in THP‐1 monocytes/macrophages
Authors: Zingg Jean-Marc , Hasan Syeda Tahira , Cowan Danica , Ricciarelli Roberta , Azzi Angelo , Meydani Mohsen
Published: June 2021

Forkhead box O3a (FOXO3a) is a transcription factor centrally involved in regulating several stress resistance and lipid transport genes. Here we investigated whether the dietary curcumin, a polyphenol in turmeric spice, can modulate FOXO3a activity and the accumulation of lipids in monocytes/macrophages, a process important in atherogenesis. Curcumin in vitro increased the expression of two lipid transport genes, the fatty acids transporter CD36/FAT and the fatty acids binding protein 4 (FABP4/aP2), leading to increased lipid levels in THP‐1 monocytes and macrophages. Curcumin increased FOXO3a activity by 2‐fold, as measured using a FOXO3a‐luciferase reporter gene, possibly as a result of influencing FOXO3a phosphorylation and nuclear translocation. In contrast to the in vitro results, supplementing the high fat diet of LDL receptor knockout mice with curcumin for four months reduced the expression of CD36, aP2, and ATP binding cassette transporter A1 (ABCA1) expression, and lowered the lipid levels in peritoneal macrophages, suggesting involvement of additional regulatory mechanisms in vivo. Thus, the modulation of FOXO3a activity by curcumin could be a mechanism to modulate lipid‐induced stress in the inflammatory cells of the vascular system and reduce the risk for cardiovascular disease. Supported by USDA Contract #58‐1950‐7‐707, and by NIFA/USDA Contract #2010‐65200‐20395.
Low‐dose endotoxemia as a human model of inflammation
Authors: Flock Mike R , Skulas-Ray Ann C , Prabhu K. Sandeep , Fleming Jennifer A , Kris-Etherton Penny M
Published: June 2021

Inflammation is important in the pathology of many diseases. We examined the safety and efficacy of a low dose in vivo endotoxin challenge (0.6 ng/kg intravenous lipopolysaccharide) for inducing inflammation in humans. Healthy men (n=6) were randomized to a 2‐period, saline placebo‐controlled, crossover design. Blood samples were taken at 0 (pre‐injection), 1, 2, 3, 4, 6, 12, 24, 48, 72, and 120 hours post‐injection. All meals were standardized and controlled for the first 12 hours. A mixed linear model demonstrated a treatment by time interaction for TNF‐α, IL‐6, and hs‐CRP (p < 0.0001 for all) and post hoc analyses, after adjustment for multiple comparisons, indicated several time specific differences (p < 0.05). TNF‐α increased versus placebo at 1, 2, 3, and 4 hours post‐injection (19.8 vs 0.9, 27.9 vs 0.9, 13.4 vs 0.9, and 7.1 vs 0.9 pg/mL, respectively). Similarly, IL‐6 increased at 2, 3, and 4 hours versus placebo (21.7 vs 0.9, 25.1 vs 2.0, and 16.4 vs 2.7 pg/mL, respectively). Serum hs‐CRP increased at 12, 24, 48, and 72 hours versus placebo (9.3 vs 0.7, 16.7 vs 0.7, 8.3 vs 0.8, and 4.6 vs 1.2 mg/dL, respectively). Our findings demonstrate the safety and efficacy of a low dose endotoxin challenge to induce inflammation as evident by increases in TNF‐α, IL‐6, and hs‐CRP. Thus, the endotoxemia model can be used to characterize metabolic changes during inflammation and identify interventions to ameliorate inflammation.

Grant Funding Source: USDA
Suppression of Skeletal Muscle Inflammation by Muscle Stem Cells
Authors: Proto Jonathan , Lu Aiping , Imbrogno Kayla , Tang Ying , Robbins Paul , Wang Bing , Huard Johnny
Published: June 2021

Recently, we have reported that intramuscular (i.m.) injection of muscle‐derived stem cells (MDSCs) heterozygous for the NF‐kB subunit p65 (p65+/−) reduces host inflammation and fiber necrosis following muscle injury more so than wild type (WT) MDSC injection. In vitro inflammation assays demonstrated that MDSCs secrete factors that modulate cytokine expression in LPS‐activated macrophages, and genetic reduction of p65 enhances this effect. We have also found that the anti‐inflammatory protein hepatocyte growth factor is more highly expressed in p65+/−cells. In order to investigate the impact of these observations in vivo, we performed i.m. injections of WT or p65+/−MDSCs into WT mouse muscle 24 hrs post injury. We followed cell fate at 1, 3, and 7 days post‐injection. At 24 hrs we observed a higher number of engrafting WT cells, but a higher percentage of proliferating (Ki67+) p65+/− MDSCs. By 3, and 7 days, the number of p65+/−MDSCs exceeded that of WT cells. These preliminary results suggest a novel role for NF‐kB in stem cells, one in which the anti‐inflammatory properties of MDSCs are regulated by NF‐kB via growth factor expression and cell proliferation kinetics.

Grant Funding Source: Department of Defense
Hypoxia‐induced compression of the tracheal system in the caterpillar, Manduca sexta
Authors: Greenlee Kendra J , Socha John J , Eubanks Haleigh B , Lee Wah-Keat , Kirkton Scott D
Published: June 2021

Abdominal pumping in caterpillars has only been documented during molting. Here, with synchrotron x‐ray imaging and high‐speed flow‐through respirometry, we show that Manduca sexta caterpillars contract their bodies in response to hypoxia, which results in significant compression of the tracheal system. Tracheal compression induced by abdominal contraction appears to be the driving force for external gas exchange, as evidenced by the high correlation between CO2 emission peaks and external body movements. Both frequency and diameter of tracheal compression increased with body mass as caterpillars increased in age. However, abdominal pumping was only observed in larger, older caterpillars (> 0.2 g body mass), suggesting that the hypoxia response varies with ontogeny. As insects increased in size, the fraction of tracheal system structures in the head increased, but not as much as would be predicted based on geometric scaling. The fraction of the body occupied by tracheae in the prothorax and last abdominal segment remain constant throughout ontogeny. Furthermore, diameter of major tracheae either do not vary with body mass or do not increase as much as expected, suggesting that trade‐offs between non‐respiratory structures result in smaller tracheae than would be expected based on geometric scaling. (Supported by NSF, NIH‐NCRR and US DOE)
Mitochondrial DNA haplotype association in mice selectively bred for high voluntary wheel running
Authors: Wone Bernard , Schutz Heidi , Meek Thomas H. , Garland Theodore
Published: June 2021

Mitochondrial DNA (mtDNA) haplotypes have been associated with various human and rodent phenotypes, such as nonshivering thermogenesis capacity, learning capability, and disease risk. Although the mammalian mtDNA control region (D‐loop) is highly polymorphic, D‐loops in laboratory mice are apparently identical, and variation occurs elsewhere in the mitochondrial genome – mainly between nucleotide base pairs 9820 and 9830. In fact, this region has been associated with reactive oxygen species (ROS) production. We hypothesized that the capacity for high levels of wheel running activity would be associated with mtDNA haplotype. To test this, we analyzed the polymorphic region of the mitochondrial genome in ~ 10 mice from each of 4 replicate lines selectively bred for 54 generations for high voluntary wheel running and from 4 non‐selected control lines. Sequencing of this polymorphic region revealed a variable number of adenine repeat insertions within and among the lines of mice. Four lines were fixed with 9 adenine repeats, two were fixed with 10, and 2 were variable with 9–11 adenine repeat insertions. These adenine repeat insertions will be tested for correlations with body mass, litter size, and wheel running activity. This system may provide an experimental model to dissect the physiological processes linking mtDNA single nucleotide polymorphisms to exercise activity. Supported by NSF IOS‐1121273 to TG.
Effects of Varying Exercise Intensities on GDNF Expression and Neuromuscular Junction Morphology
Authors: Gyorkos Amy Morrison , McCullough Monica , Spitsbergen John
Published: June 2021

Glial cell‐line derived neurotrophic factor (GDNF) supports and maintains the neuromuscular system during development and through adulthood by promoting neuroplasticity. The aim of this study was to determine if different intensities of exercise can promote changes in GDNF expression and neuromuscular junction (NMJ) morphology in slow‐ and fast‐twitch muscles. Rats were randomly assigned to a low intensity run‐training (run group), higher intensity swim‐training (swim group), or control group. GDNF protein content increased in both soleus (SOL) and extensor digitorum longus (EDL) following run‐training and in EDL following swim‐training determined by enzyme‐linked immunosorbent assay. NMJ morphology was analyzed by measuring α‐bungarotoxin labeled post‐synaptic end plates. GDNF and total end plate area were positively correlated. End plate area decreased in EDL of run group and increased in SOL of swim group. Run group was able to alter plasticity by significantly increasing the number of end plates in EDL. The higher intensity swim‐training elicited more dispersed synapses in SOL and less dispersion in EDL. The results indicate that GDNF expression may be altered depending on exercise intensity and fiber phenotype potentially inducing NMJ plasticity. This work was supported by NIH grant 1 R15 AG022908‐01A2, NSF grant DBI 0552517 and Western Michigan University.
Exploring CO2 permeability of plant aquaporins
Authors: Qin Xue , Hu Honghong , Schroeder Julian I , Boron Walter F
Published: June 2021

Previous work showed that tobacco aquaporin can mediate CO2 transport and has significant function in photosynthesis and in stomatal opening. However, the CO2 permeability of aquaporins in Arabidopsis had not been fully investigated. Here we study the CO2 permeability of aquaporins expressed in Arabidopsis. We monitored cell swelling under hypotonic conditions to compute osmotic water permeability (Pf), and used microelectrodes to monitor the maximum rise in extracellular surface pH (ΔpHS) caused by CO2 influx into Xenopus oocytes (an index of CO2 permeability). When exposed to CO2, oocytes injected with different subclasses of plant aquaporins had different ΔpHS changes compared with day‐matched H2O‐injected oocytes. Under hypotonic conditions, oocytes injected with different subclasses of plant aquaporins also exhibit different water permeability. In addition, when the plant aquaporins are co‐expressed with other candidate regulators of CO2 transport, we also observed different modulation of ΔpHS. In conclusion, these data implicate a plant aquaporin in Arabidopsis, in the transport not only of water but also of CO2, and raise the possibility of the regulation of CO2 permeability. Funded by AHA 11POST7670014 & ONR N00014‐ 08‐10532.
Recombinant erythropoietin administration reduces exercise‐induced deline in regional cerebral oxygenation at 4500 m
Authors: Muza Stephen Raymond , Jones Juli E. , Fulco Charles S. , Beidleman Beth A. , Staab Janet E.
Published: June 2021

At high altitude, exercise‐induced arterial desaturation decreases regional cerebral oxygenation (rO2Hb). Erythropoietin (EPO) potentiates endothelium‐mediated dilation of isolated, perfused rat middle cerebral arteries. To determine if EPO administration in humans mitigated the decreased cerebral rO2Hb during exercise within the first 3 h at 4500 m eight healthy male lowlanders received a subcutaneous injection of either EPO (600 IU/Kg) or a placebo (PLA) (0.9% NaCl) ~12 hr prior to ascent in a hypobaric chamber in a double‐blind, cross‐over study. We measured frontal lobe rO2 Hb by NIRS, arterial saturation (SaO2) by pulse oximetry, and PetO2 and PetCO2 by metabolic cart during rest and 50 W cycling. At 4500 m, serum EPO levels were (mean ± SD) 6 ± 2 and 720 ± 273 mU/ml for PLA and EPO trials, respectively. From rest‐to‐ exercise SaO2 decreased similarly in both trials (PLA: −6 ± 4 and EPO: −8 ± 4%), but rSO2 declined less in EPO (PLA: −2.12 ± 1.93 and EPO: −1.47 ± 2.40 μM, p=0.027), while rest and exercise PetO2 and PetCO2 were similar for both trials.

Conclusion

since PO2 and PCO2 were constant and not likely changing cerebral vasomotor activity, the smaller exercise‐induced decline in rO2Hb following EPO administration supports the hypothesis that increasing circulating EPO potentiates dilation of cerebral blood vessels at high altitude. Funding: USAMRMC. Authors’ views; not official U.S. Army or DoD policy.
Food photo records for assessing daily food intake using a smart phone application in college students
Authors: Suzuki Asuka , Pope Benjamin T , Roe Denise , Orr Barron J , Merchant Nirav C , Going Scott B , Hongu Nobuko
Published: June 2021

With the aim of developing a new dietary instrument for increasing awareness of individual's usual dietary intake and eating pattern, we evaluated an application in a smart phone with camera and internet capability called Recaller application. College students used the Recaller application to take photos of all food eaten in six days during a three week period. The following day a 24‐hour recall was administered by a dietitian, and a Recaller usability feedback questioner was filled out by each participant at the end of the study. Forty one college students (22 females; the median BMI of 22.3 kg/m2 and 19 males; median BMI of 24.6 kg/m2), median ages of 22 years participated in the study. The median number of picture taken per participant throughout the study was 84.5 for female and 66 for males. The Wilcoxon rank‐sum test revealed that there was no difference in the total number of pictures taken between females and males (p=0.0858). Most participants rated the Recaller application as extremely easy or easy to use. 50–60% of participants said they would use the application daily to track the foods they eat. The Recaller smart‐phone application has potential to be used as a nutrition assessment tool, and may be an effective and efficient technique to keep food photo records, and potentially improve diet awareness of college students.

Supported by USDA, NIFA, Human Nutrition and Obesity Program and University of Arizona, Foundation

Grant Funding Source : USDA
Effects of Maternal Nutrition Excess (MNE) on Fetal Cardiac Mitochondrial Transcripts and Protein at 0.9 G in Non‐Human Primates (NHP)
Authors: Pereira Susana P , Oliveira Paulo J , Cox Laura A , Nathanielsz Peter W , Nijland Mark J
Published: June 2021

Maternal obesity predisposes offspring to metabolic dysfunction and type‐2 diabetes, with implications in organ dysfunction, namely in the cardiovascular system. We hypothesized that MNE during gestation can impact mitochondrial biogenesis and function. Female baboons were fed regular chow (12% energy fat, n=12) or MNE diet (45% energy fat and ad libitum fructose sodas, n=5). At conception, MNE mothers were more obese and weighed more than regular chow controls. MNE fetuses were lighter (816.9±33.9g vs 675.2±35.7g) and presented a lower BMI. At 0.9G, MNE did not affect fetal heart weigth or heart:body weight ratio. Transcriptome analysis of the free wall of the 0.9 G cardiac left ventricle of MNE fetuses showed 3,033 diferently expressed genes, with more than 100 related with mitochondria. Transcripts for Complex I (NDUFB3 and NDUFB6), Complex II (SDHC), Complex IV (COX6C and COX7C), Complex IV (ATP6VOA2 and ATP5A1) and the phosphate carrier were decreased in the MNE fetus. Variations in mRNA levels were accompained by decreased protein levels of subunits from Complex III (CIII‐core I), Complex IV (COX‐II), Complex V (CV), as well as cyclophilin D. MNE induces 0.9G mitochondrial transcriptional and protein alterations in the cardiac left ventricle, which may impact normal heart development and predispose for metabolic disturbances later in life. Supported by NIH PO1 HD023150 and FCT SFRH/BD/64247/2009
Evolution and Specializations of Insect Eyes: Twisted‐Wing Insects and Larval Diving Beetles.
Authors: Buschbeck Elke K
Published: June 2021

Although most insects have compound eyes, considerable variation has evolved among their visual systems. Here I present two examples of insect eyes for which anatomical characteristics provided important clues to their functional organization. In adult male Strepsiptera large lenses and cup shaped retinae suggested the presence of small image‐forming eyes in place of ommatidia that otherwise are observed in compound eyes. Behavioral tests of the spatial resolution confirmed increased image resolution of these “eyelets”. The bizarre tubular eyes of diving beetle larvae serve as another example: here, multiple linear retinae pointed to the possibility that these eyes may be used to scan the environment. Behavioral tests showed that this indeed is the case. Moreover the ultrastructural organization of microvilli within its UV‐sensitive distal retina implied that these cells could be polarization sensitive, a functional characteristic that we have confirmed physiologically. Although most insect eyes fall into a few well‐characterized categories, anatomical studies of highly unusual eyes continue to point towards interesting novel functional organizations of visual systems. This research is supported by the National Science Foundation.