bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibition of Pulmonary Anti‐Bacterial Defense by IFN‐γ Induced During Influenza Virus Infection
Authors: Sun Keer , Metzger Dennis W.
Published: June 2021

Secondary bacterial infection often follows pulmonary virus infection and is a common cause of severe disease in humans, yet the mechanisms responsible for this viral‐bacterial synergy in the lung are only poorly understood. We found that pulmonary IFN‐γ produced during T cell responses to influenza infection inhibited initial bacterial clearance from the lung by alveolar macrophages. This suppression of phagocytosis then led to enhanced susceptibility to secondary pneumococcal infection, which could be prevented by IFN‐γ neutralization following influenza infection. Inoculation of exogenous IFN‐γ i.n. to naive mice mimicked viral infection and led to decreased bacterial killing. Thus, IFN‐γ, while likely facilitating induction of specific anti‐influenza immunity, suppresses innate protection against extracellular bacterial pathogens in the lung. (Supported by NIH grant RO1 AI 41715)
TNF‐related apoptosis‐inducing ligand (TRAIL) expression on CD8+ T cells helps control primary influenza virus infections
Authors: Brincks Erik L. , Legge Kevin L , Griffith Thomas S
Published: June 2021

Clearance of primary influenza virus infection is mediated by influenza‐specific CD8+ T cells, which promote recovery by killing infected cells via perforin‐ and FasL‐mediated mechanisms. Recently, TRAIL expression was reported on NK and T cells after influenza infection, suggesting a role for TRAIL‐induced apoptosis in the immune response to influenza. We hypothesize that influenza‐specific CD8+ T cells kill infected cells via TRAIL/DR5 interactions during the immune response to influenza virus infection. We show that infection of TRAIL−/− mice results in increased morbidity and antigen load compared to TRAIL+/+ mice. After infection, TRAIL is upregulated on pulmonary CD8+ T cells in an influenza‐specific manner, and infected cells show increased DR5 expression relative to uninfected cells. Interestingly, pulmonary CD8+ T cells in TRAIL−/− mice have decreased in vivo killing capacity compared to those in TRAIL+/+ mice. Further, transfer of CD8+ T cells from TRAIL+/+ mice, but not TRAIL−/− mice, primed with a sub‐lethal dose of influenza rescues recipient mice from lethal influenza virus infection. These data suggest that TRAIL is an important component of CD8+ T cell immunity to influenza virus infection, and that TRAIL deficiency decreases the cytotoxicity of CD8+ T cells and diminishes their ability to protect from lethal doses of influenza. Supported by: NIH (R21 AI072032), & AHA predoctoral fellowship.
Vaccination‐induced mortality in perforin‐deficient mice: Implications in the vaccination of patients with familial hemophagocytic lymphohistiocytosis
Authors: Pham Nhat‐Long Lam , Badovinac Vladimir P , Harty John
Published: June 2021

Hemophagocytic lymphohistiocytosis (HLH) is a life‐threatening condition, often triggered by viral infection and characterized by severe hyperinflammation caused by uncontrolled proliferation of activated lymphocytes and histiocytes. Mutations in perforin gene have been linked to familial HLH2 in humans. Naïve perforin‐deficient (PKO) BALB/c mice survive primary LCMV infection, but fail to clear the virus and become persistently infected. However, PKO mice previously vaccinated with LCMV dominant NP118 epitope rapidly succumb to LCMV challenge and die. Massive expansion of NP118‐specific CD8+ T cells and dysregulated cytokine production contribute to the mortality. We hypothesized that the number of NP118‐specific memory CD8+ T cells at the time of LCMV challenge would determine the CD8+ T cell expansion and mortality in these mice. To test this, we generated different numbers of stable memory NP118‐CD8+ T cells in PKO mice. In contrast to our starting hypothesis, all these mice succumb to the LCMV challenge, despite having different levels of NP118‐specific memory CD8+ T cells at the time of LCMV challenge. These results may impact the utility of vaccination of fHLH patients.
Effects of Antiretroviral Protease Inhibitors on Live Poxvirus‐mediated Target Antigen Expression
Authors: Yu Qigui , Shikuma Cecilia , Shiramizu Bruce , Yewdell Jonathan W. , Moss Bernaid , Hu Ningjie
Published: June 2021

Background: Live poxvirus‐based HIV‐1 vaccines have been tested as therapeutic vaccines and live highly attenuated strains of modified vaccinia Ankara (MVA) has been evaluated as an alternative vaccine against smallpox in HIV‐1‐infected individuals receiving antiretroviral therapy (ART). The objective of this study was to determine the affect of ART on poxvirus‐mediated target antigen expression, processing, and presentation. Methods: Using a recombinant EGFP‐expressing VV (EGFP‐VV), we studied the efficiency of virus‐mediated protein expression in primary human monocytes in the presence of HIV‐1 protease inhibitors (PIs). Results: The PI, atazanavir, significantly inhibited EGFP expression in primary human monocytes infected with EGFP‐VV. Further studies demonstrated that atazanavir could block VV‐induced activation of PI3K signaling pathway in monocytes. PI3K was the most critical pathway among four cellular signaling pathways (PI3K, p38 MAKP, JNK, and ERK) examined in antigen expression by VV‐infected cells, as blocking the PI3K pathway with the specific inhibitor LY294002 at 25 μM exhibited 90.1% decrease of EGFP expression compared to non‐inhibitor‐treated control (DMSO).

Conclusions: The HIV‐1 protease inhibitor, atazanavir, significantly inhibited EGFP expression in primary human monocytes infected with EGFP‐VV, probably through blockage of PI3K pathway.
NK Cells Dominate the Immunopathogenesis of Fatal Ehrlichiosis
Authors: Crossley Emily C , Stevenson Heather L , Ismail Nahed , Walker David H
Published: June 2021

Human monocytic ehrlichiosis (HME) is a potentially lethal, tick‐transmitted infection caused by the obligately intracellular bacterium Ehrlichia chaffeensis. C57BL/6 mice model severe HME when infected with Ixodes ovatus Ehrlichia (IOE); they succumb to a toxic‐shock like syndrome mediated in part by TNF and CD8+ T cells and characterized by lymphopenia and by liver apoptosis and necrosis. CD4+ T cells mediate a protective IFN‐γresponse. The aim of this study was to compare the contribution of NK cells to that of T cells in the pathogenesis of ehrlichiosis. Flow cytometry was used to track splenic NK cells (NK1.1+, CD3−), NKT cells (NK1.1+, CD3+), T cells (CD3+, NK1.1−) and monocytes (CD11b+, NK1.1−) over the course of disease; these populations failed to expand but rather contracted before the animals’ death. Furthermore, splenic NK cells produced more IFN‐γ, TNF, granzyme B and Fas than did NKT or T cells. We depleted NK cells with anti‐asialo GM1 immune serum and observed reduced serum concentrations of IFN‐γ, TNF, and IL‐10 by ELISA, lower bacterial burdens in the spleen, liver, and lung by real‐time PCR, and attenuated liver injury by histopathology. Our data indicate that NK cells, rather than T cells, are the dominant contributors to the pathogenic immune response against IOE infection.
Helminth‐induced alternatively activated macrophages enhance susceptibility to tuberculosis
Authors: Potian Julius Andrew , Bhatt Kamlesh , McBride Amanda , Gause William , Salgame Padmini
Published: June 2021

Regions of the world with high incidence of tuberculosis (TB) are also endemic for helminthic diseases. The impact of the Th2 response elicited by helminthic infections, which may alter the Th1 response necessary for the protection to TB, is poorly understood. Co‐infection of BALB/c mice with the nematode Nippostrongylus brasiliensis (Nb) followed by virulent Erdman strain of Mtb via aerosolization demonstrated at 4 and 7 weeks post‐Mtb infection, significantly higher bacterial burden in co‐infected mice compared to mice infected with Mtb alone. This correlated with an increase in expression of Th2 cytokines, IL‐4 and IL‐10, as well as markers for alternative macrophage activation (AAMφ) in co‐infected mice. Co‐infection of IL‐4 Rα−/− mice restored bacterial burden to wild‐type levels. Ongoing studies will determine the mechanism by which AAMφ alter the immune response to Mtb. Taken together, these results demonstrate that helminthic infection leads to development of AAMφ, which may ultimately modulate the ability of the host to mount an effective immune response to TB.
Intrathecal antibody production in the Theiler's murine encephalomyelitis model of multiple sclerosis
Authors: Pachner Andrew Rudolf , Brady Jennifer , Narayan Kavitha
Published: June 2021

Objective: To assess the role of intrathecal antibody production (ITAbP) in a murine model of multiple sclerosis(MS).

Background: ITAbP is a hallmark of MS, but is poorly understood. Infection of mice with Theiler's murine encephalomyelitis virus (TMEV) results in a progressive disabling demyelinating disease resembling MS, but the role of antibody in central nervous system(CNS) injury in this model is unknown.

Design/Methods: ITAbP in TMEV‐induced demyelinating disease(TMEV‐IDD) was measured using ELISpot for IgG‐producing cells and RT‐PCR for IgG1 mRNA, viral load was determined by RT‐PCR for TMEV RNA, and CNS injury was measured by Rotarod analysis of infected mice. Demyelination and immunoglobulin deposition were assayed histologically in the spinal cord by luxol fast blue and immunofluorescent staining, respectively.

Results‐Robust ITAbP was present in 85% of infected mice and correlated positively with CNS injury and viral load. Demyelination and immunoglobulin deposition in injured tissue was prominent in mice with ITAbP.

Conclusions/Relevance: ITAbP and immunoglobin deposition is highly associated with CNS injury in a murine viral model of MS. These data provide evidence that intrathecally produced antibody may contribute to CNS injury.
CD4+CD25+FoxP3+ T Regulatory Cells Play a Critical Role in Tolerance to Pancreatic Islets Engineered to Display on Their Surface an Exogenous FasL Protein
Authors: Yolcu Esma S. , Zhao Hong , Bandura‐Morgan Laura , Lacelle Chantale , Askenasy Nadir , Shirwan Haval
Published: June 2021

Objective: We have shown that islets engineered to display on their surface a chimeric form of FasL with streptavidin (SA‐FasL) induce robust localized tolerance when transplanted into allogeneic recipients. The objective of this study was to elucidate mechanisms of tolerance in this model.

Methods: RIP‐OVA BALB/c islets were engineered by cell surface modification with biotin followed by the display of chimeric SA‐FasL. SA‐FasL‐engineered islets were transplanted into streptozotocin diabetic C57BL/6 mice under transient cover of rapamycin. Graft recipients were adoptively transferred with OT‐I TCR transgenic T cells and analyzed for donor‐specific proliferation, clonal deletion, and increased frequencies of T regulatory cells (Treg).

Results: Long‐term recipients generated a normal proliferative and cytokine response to donor antigens, demonstrating lack of systemic tolerance. Graft acceptance involved clonal deletion of alloreactive T cells within the kidney draining lymph nodes early post‐transplantation. Although analysis of CD4+CD25+FoxP3+ Treg cells did not revealed their increased frequency in the periphery as compared with rejecting controls, in vivo depletion of Treg cells using an antibody to CD25 early or late post‐transplantation resulted in prompt rejection of tolerated grafts.

Conclusion: Tolerance to SA‐FasL‐engineered islets is localized to the graft and involves clonal deletion of alloreactive T cells early post‐transplantation followed by generation/induction of Treg cells that maintain tolerance. NIH (R21 DK61333, R01 AI47864, R21 AI057903, R21 HL080108), JDRF (1‐2001‐328), and ADA (1‐05‐JF‐56).
Donor‐specific memory CD4 T cells provide help for alloantibody production in the absence of CD40/CD154 interactions and germinal center formation
Authors: Rabant Marion , Gorbacheva Victoria , Zhang Qi‐Wei , Kolkin Mark , Valujskikh Anna
Published: June 2021

CD40 signaling is essential for immunoglobulin class switching in response to T‐dependent antigens. We investigated whether memory CD4 T cell help can be delivered in the absence of CD40/CD154 interactions.

We used either polyclonal alloreactive memory CD4 T cells from C57BL/6 (B6, H‐2b) recipients of C3H (H‐2k) skin allografts or TCR transgenic Mar memory CD4 T cells reactive to male HYDby peptide. Wild type B6 or CD40−/− female mice injected with naïve or memory CD4 T cells received heterotopic heart transplants from male C3H donors, donor‐reactive serum alloAb titers were determined by flow cytometry.

We observed that memory but not naïve CD4 T cells induced high titers of donor‐specific IgG Ab in wild type B6 recipients treated with anti‐CD154 mAb MR1. After adoptive transfer into CD40−/− mice, memory, but not naïve CD4 cells provided help to CD40−/− B cells to produce donor‐reactive IgG1, IgG2a, IgG2b and IgG3 as early as 1 week post transplant. Despite high titers of serum IgG, PNA and B220 staining revealed no germinal center formation in the spleens of CD40−/− recipients containing memory CD4 T cells. AlloAb production was not affected by the treatment of CD40−/− recipients with MR1 Ab or anti‐ICOS mAb, indicating that the memory CD4 T cell help to CD40−/− B cells was independent of CD154 engagement by an alternative ligand or ICOS/B7RP‐1 pathway.

In summary, donor‐specific memory CD4 T cells can initiate alloAb response in CD40‐deficient heart allograft recipients. Thus, therapeutic interruption of CD40/CD154 signaling may fail to efficiently block de novo alloantibody production in T cell sensitized transplant patients.
Chlamydia pneumoniae infection accelerates rat cardiac allograft chronic rejection but does not impact graft survival in the absence of alloreactivity
Authors: Wagner Cynthia Reed , Yin Qiang , Corless Christopher L , Ybarra Noel , Bonneval Aimee , Manoharan Minsha , Hinrichs David J
Published: June 2021

Chlamydia pneumoniae (Cpn) infection has been associated with graft chronic rejection (CR) in human heart and liver transplant recipients, though the high frequency of human Cpn infection confounds such studies. Therefore, we tested whether Cpn infection accelerates CR in a rat cardiac allograft model. F344 rat hearts were heterotopically transplanted into Lewis recipients, either treated with CsA or previously made chimeric with F344 bone marrow cells. Cpn administration resulted in disseminated infection. The allografts were palpated daily until pulsation was no longer detectable (graft failure), or post‐operative day (POD) 120 (maximum study length). F344 allografts in Lewis recipients infected with Cpn on POD 1, POD 7, or PODs 1 and 19 failed significantly earlier than those in the control group. Preexisting recipient infection also significantly accelerated CR, while preexisting donor infection did not accelerate CR. Accelerated CR required infectious Cpn. Chimeric Lewis rat recipients rejected third party allografts, but did not reject F344 allografts regardless of recipient Cpn infection. Therefore rat cardiac allograft recipient Cpn infection, either prior to, at the time of, or a week following transplantation, accelerates CR but does not impact graft survival in the absence of alloreactivity. Supported by Merit Review Funds, Dept. of Veterans Affairs.
Cellular analysis of B cell activation in the rainbow trout.
Authors: Zwollo Patty , Mott Katrina , Rosato Pam , Haines Ashley , Coyner Kristin
Published: June 2021

Teleosts including the rainbow trout provide an interesting animal model, as they do not possess bone marrow or lymph node tissue. In trout, the anterior kidney is the main site for B lymphogenesis throughout life. Our lab uses expression patterns of B cell‐specific transcription factors as markers to investigate B cell development and activation in the trout. In mammalian species, transcription factors Pax5 and XbpI provide accurate markers for the terminal differentiation stages of B cells. Pax5 is expressed in mature and plasmablast stages but absent from plasma cells, while XbpI is not induced until the activated B cell stage. In this study we wished to investigate the activation stages of trout B cells using expression patterns for Pax5, XbpI, membrane and secreted immunoglobulin. In order to determine activation states in individual B cells, fixed and permeabilized trout immune cells were analyzed by flow cytometry using Pax5, XbpI, and Ig specific antibodies. This approach lead to the detection of three major B cell activation stages in trout immune tissues: the resting mature B cell stage, the activated B or plasmablast stage, and the plasma cell stage. Different immune tissues had different frequencies of each activation stage. While freshly isolated trout spleen and PBLs contained mostly resting mature B cells, anterior and posterior kidney tissues contained significant populations of Ig‐secreting cells. LPS‐activation lead to increased frequencies of activated B cells in spleen, but not PBL, while anterior and posterior kidney lose their Ig‐secreting cells. Our studies show for the first time that Pax5, XbpI, and IgM markers can be used in flow cytometric analyses to distinguish between resting B cells, activated B cells, and plasma cells of the rainbow trout. This research was funded through an AREA grant from the NIH.
Coordinated p27 Kip1 expression as a function of distance between crypts ‐ Potential inter‐crypt signaling
Authors: Hong Mee Young , Baladandayuthapani Veerabhadran , Li Yehua , Carroll Raymond J , Turner Nancy D. , Lupton Joanne R
Published: June 2021

Colonic epithelial cells are arranged in patterns called crypts. There has been a conjecture that a coordinated response exists at the crypt level, i.e. that biological responses in one crypt affects the biological responses in neighboring crypts. P27Kip1 (p27) is a cyclin dependent kinase inhibitor, which arrests cell cycle progression and induces apoptosis. We hypothesized if a crypt has high p27 expression, the neighboring crypts are likely to have high p27 expression. To test the hypothesis, 20 colonic crypts in each of 12 rats were analyzed for p27 levels and the distance between the crypts were measured. The correlation between the p27 expression between the crypts were analyzed using Bayesian statistical methods. The correlation at 25 μm was 0.57 and the correlation was positive for distances up to 400 μm (p<0.05). The closer crypts were to one another the better the correlation. This observation supports the existence of inter‐crypt signaling; p27 expression in crypts which are in close proximity tend to have similar expression levels. This type of inter‐crypt signaling may be responsible for the formation of aberrant crypt foci, polyps and eventually colon adenomas. This spatial analysis is a novel mathematical approach to study of colon carcinogenesis. Funded by NIH (CA61750, CA82907, CA59034), NSBRI NASA NCC 9–58 and NIEHS P30‐ES09106.
Impact of pyridoxine (B6) deficiency on serine kinetics in the pig
Authors: House James D. , Zhang Zhenbin , Nitschmann Evan , Wykes Linda J.
Published: June 2021

The water‐soluble vitamin B6 serves a cofactor for serine hydroxymethyltransferase (SHMT), an enzyme critical to cellular one carbon flow. The current experiment was designed to test the alternate hypothesis that B6 deficiency in an animal model will reduce SHMT activity and serine flux, as measured by stable isotopic dilution protocols. Pigs (commercial genotype; initial wt = 4.7 kg; n=6/treatment) were offered a basal semi‐purified diet (20.5% casein; 3474 kcal ME/kg) containing either 0 (B6−) or 3 (B6+) mg/kg pyridoxine·HCl for a 3 week feeding period, using a pair‐feeding design. At the end of the depletion period, a 6 hr primed (90 μmole/kg)‐constant (90 μmole/kg/h) infusion of L‐[2,3,3‐2H3] serine was administered via indwelling jugular vein catheter. Blood samples (femoral vein catheter) were collected at −60, 0, 60, 120, 180, 240, 300 and 360 min. Tissues were harvested at termination and samples processed for plasma serine m+3 enrichment (GC‐MS), plasma pyridoxal‐5‐phosphate (PLP; radioimmunoassay), and liver SHMT activity. Different superscripts indicate significant differences (P<0.05) by ANOVA F‐test.

The current data allow us to accept the alternate hypothesis of a reduction in SHMT activity induced by dietary pyridoxine deficiency, with a concomitant reduction in serine flux. This reduction in serine flux may have implications for overall one‐carbon metabolism, including pathways linked to folate and sulfur amino acid metabolism. Support: Natural Sciences and Engineering Research Council of Canada (NSERC)
Does measurement define hunger, or does hunger define measurement?
Authors: Radimer Kathy
Published: June 2021

Hunger was “discovered” in the US in the 1960s, the 1980s, and again in the 2000s, but definitions and measurement have varied over time, to include physical and biochemical measures, dietary intake, food‐related behaviors, psychological conditions, and physical sensations. In the 1960s, assessment particularly focused on anthropometry and clinical symptoms, generally undertaken by medical professionals. In the 1980s, community groups tracked food pantry and soup kitchen usage and user characteristics, noting the coincidence with food stamp receipt cycles. Several efforts to develop a hunger measure were undertaken.

In the mid‐1990s, the US government held a conference to develop a U.S. measure of hunger and related conditions, bringing together previous work. Hunger was subsumed into the broader framework of “food insecurity” as the most severe category of food security, “food insecure with hunger.” In 2004–06 the Committee on National Statistics (of the National Academies) undertook a review of the US food security survey module and the measurement and reporting methods. It recommended that the word “hunger” not be used as a food security category label, because hunger is a physiological condition, not an economic or social condition. Measurement and language are inextricably entwined in the assessment and depiction of hunger in America.
Validity of the Latin American and Caribbean Household Food Security Scale (ELCSA) in Guanajuato, Mexico
Authors: Perez‐Escamilla Rafael , Paras Pablo , Hromi‐Fiedler Amber
Published: June 2021

We tested the validity of ELCSA in a representative public opinion survey of 863 households with children under 18 y old in the state of Guanajuato. ELCSA was applied to the respondents in Spanish, contained 16 items and used a reference period of 3 months. Cronbach's alpha was 0.93. Based on affirmative response prevalence, the severity of items was fully consistent with theoretical expectations. Worrying about the food supply was the most prevalent item followed by items referring to dietary quality in adults, hunger in adults, dietary quality in children and finally hunger in children. 31% of households were food secure (item additive score=0), 37% were mildly FI, 20% were moderately FI and 11% were extremely FI. Criterion validity was strong. There was an inverse dose‐response relationship between household income and level of severity of FI (p<0.001) with 32.8% of household reporting severe FI if they had a monthly income of less than US$80 compared to 0% among those earning an income ranging from US$1,600 to US$3,000. Likewise, the prevalence of severe FI was 18.9% in households where the respondent had no formal education compared to 3.3% in households where the respondent had college level education. Results suggest that ELCSA is a valid tool for assessing household FI in Mexico. Implemented by Data OPM with funding from the Government of the State of Guanajuato.
The Plateau Effect in Waist Circumference and Body Composition: The Rule of First Order Change
Authors: Hargrove James L. , Heinz Grete
Published: June 2021

Dieters and weight‐lifters find that rates of weight loss or weight gain are rapid when a new training program is started, but that the rate diminishes until a plateau is reached. The plateau can be explained if anthropometric measures follow apparent first order kinetics in which change is modeled with a fixed input (food or new synthesis of body mass) and first order rate of loss. We used statistical software to test whether rates of change in body proportion from The Biology of Human Starvation by Ancel Keys et al.(1950) follow first order kinetics. The study began with 2 wks of food intake of 3400 kcal that was decreased to 1600 kcal for 24 weeks. Thereafter, food intake was increased in steps back to normal levels. Essentially all anthropometric and physiological measures showed rapid initial change that slowed as the study progressed. The data for body mass, fat mass, waist and limb girths, strength and urinary N excretion fit well to models based on first order (exponential) decline. First order rate parameters were not identical for different indices. For example, the rate parameter for waist circumference was 0.11 wk−1 but for fat mass it was 0.049 wk−1. During the refeeding phase, the regain also fit a model based on first order kinetics. The data are consistent with the concept that a number of anthropometric and physiological variables can be modeled on the assumption that change follows first order kinetics.
Anorexia, Taste and Smell Dysfunction and Cytokine Changes in the Elderly
Authors: Henkin Robert I. , Velicu Irina , Schmidt Loren
Published: June 2021

There is an epidemic of anorexia among elderly in nursing homes in the US. This anorexia is accompanied by weight loss, limitation of intake of critical nutrients and physical wasting. Attempts to remedy these events with commercial nutrient mixtures have been futile. Many of these patients have losses of taste and smell as either accompaniments or causes of their anorexia. To understand these events we hypothesized that their loss of taste and smell function were important in limiting their interest in food and drink. To test this we measured taste and smell function and several cytokines in blood, urine, saliva and nasal mucus in a group of elderly subjects. They showed decreased ability to judge intensity of tastants and odorants consistent with decreased number of taste bud and olfactory receptor cells. They also showed decreased levels of cAMP and cGMP and increased levels of TNF alpha and IL 1 in saliva and nasal mucus but not in blood or urine compared to younger subjects. These results show a decrease in growth and maturation coupled with increased apoptosis and inflammatory parameters in these sensory organs, particularly taste buds as people age. These changes may contribute to the anorexia and wasting observed among some elderly. Correction of these changes could be helpful to improve nutrtion among elderly with anorexia.
Relationship of Hypoxia to inflammation and angiogenesis
Authors: Johnson Randall S
Published: June 2021

We have undertaken a genetic investigation into the mechanisms of hypoxia‐induced release of angiogenic factors. Data will be presented illustrating the role of hypoxic response during tumorigenic progression, with an emphasis on the role of the innate immune system.
Structural changes in skeletal muscles of Ossabaw miniature swine with metabolic syndrome
Authors: Kostrominova Tatiana Y , Clark Bradley A , Alloosh Mouhamad , Wenzel James W , Sturek Michael
Published: June 2021

Ossabaw swine fed excess kcal and atherogenic diets develop metabolic syndrome (MetS) characterized by obesity, dyslipidemia, hypertension, insulin resistance, and glucose intolerance. The purpose of this study was to test the hypothesis that MetS could have a detrimental effect on skeletal muscle structure and function. Adult Ossabaw swine were fed Control (C), high fructose (F) or high fat/cholesterol/fructose (H) diets for 28 weeks. Biceps femoris and plantaris muscles were analyzed. F swine showed mild MetS, lacking increase in LDL and total cholesterol, both of which were highly up‐regulated in H swine. There were no significant differences in cross sectional areas of muscle fibers of swine on C and F diets. Ossabaw swine fed H diet showed a 20% decrease in size of Type 2B fibers in biceps femoris muscles and a 30% increase in plantaris muscles. Physiological differences between these two muscles might explain these disparate findings. H diet caused increased accumulation of intramyocellular lipid droplets. This finding correlates well with a 5‐fold increase in total plasma cholesterol of H fed Ossabaw swine and suggests a role of dyslipidemia in structural defects in MetS. Support: NIH HL013223 (MS), HL062552 (MS) and IUSM‐Northwest (TK).
Zinc modulates leptin signaling in osteoblastic MC3T3‐E1 cells through activating JAK2/STAT3 pathway
Authors: Lomeda Ria‐Ann R , Cho Young‐Eun , Choi Bong‐Hyuk , Do Myoung‐Sool , Shin Hong‐In , Choi Je‐Young , Beattie John H , Kwun In‐Sook
Published: June 2021

Leptin, a cytokine‐like hormone has been reported having a dual effect on bone formation to exert direct osteogenic effects in auto/paracrine regulation and to inhibit bone formation in hypothalamic central nerve regulation. Since Zn has been shown to mediate leptin secretion and skeletal growth, leptin can be an important candidate molecule linking Zn with bone formation. The present study investigated whether Zn deficiency induces leptin secretion thus activating leptin signaling through JAK2/STAT3 pathway in osteoblastic cells. MC3T3‐E1 cells were cultured in normal osteogenic differentiation medium or Zn‐treated media, Zn− (1 μM) and Zn+ (15 μM), both containing 5 μM TPEN as Zn chelator for 24 h. Medium leptin secretion increased in Zn− which was consistent with increased leptin mRNA and protein expression in Zn−. Again, protein expression of long form leptin receptor (OB‐Rb), which conveys leptin signal increased in Zn−. Leptin‐signaling proteins, JAK2 and STAT3 in cytosol of Zn‐deficient osteoblast activated leptin signaling, which finally showed higher phosphorylated STAT3 expression in the nucleus. Early apoptotic morphological feature was shown by TEM even under activated STAT3. Altogether, results suggest that under Zn deficiency, activated leptin signaling by pSTAT3 can be considered as a compensatory regulation for cell apoptosis under Zn deficiency. (Supported by R01‐2006‐000‐10640‐0)
A fish oil/pectin diet beneficially altered gene profiles during radiation‐enhanced colon carcinogenesis
Authors: Kim Hyemee , Turner Nancy D , Taddeo Stella S , Davidson Laurie A , Wang Naisyin , Vannucci Marina , Chapkin Robert S , Carroll Raymond J , Lupton Joanne R
Published: June 2021

The goal of this project was to determine the effect of diet on the patterns of gene expression in exfoliated colonocytes from rats exposed to radiation (+/− 1 Gy, 1 GeV/nucleon Fe ions) and a chemical carcinogen (AOM, 2x, 15 mg/kg BW). Rats received corn oil/cellulose (CC) or fish oil/pectin (FP) diets for 3 wk prior to radiation exposure, which was followed by AOM injections 10 and 17 d later. Isolated poly A+ RNA from exfoliated colonocytes was analyzed using GE Codelink arrays. The radiation and diet interaction resulted in differences in expression of 95 genes, including five genes involved in the MAPK signaling pathway and regulation of autophagy. For example, irradiated rats consuming FP had ∼1.7 times the level of Ppm1b, a MAPK signaling suppressor, found in CC rats (P=0.036), suggesting the FP diet would suppress cell proliferation in rats exposed to radiation. With respect to autophagy, the expression of Atg7 in non‐irradiated rats consuming FP was higher than the level in CC rats (P=0.003), suggesting the FP rats would likely have elevated apoptosis via autophagy. FP may suppress cell proliferation and enhance autophagy in the colon and thereby suppress colon carcinogenesis caused by radiation and AOM. Supported by NSBRI (NASA NCC 9‐58), NIH (CA57030 and CA59034) and NIEHS (P30‐ES09106).
Paracrine effects of adipocytes on mammary epithelial cell cycle regulation
Authors: Connor Michael Keith , Walker O’Llenecia
Published: June 2021

To establish a molecular link between obesity and cancer we examined the paracrine role of adipocytes on MCF7 cell cycle regulation. Arrested MCF7 cells were treated with leptin (LEP) and adiponectin (ADIPO). p27 protein levels decreased and increased with LEP and ADIPO, respectively, suggesting adipokine‐mediated MCF7 cell cycle regulation. Addition of LEP overcame the effects of ADIPO on p27 protein levels. Selective JAK2 inhibition had no effect on LEP‐dependent cell cycle entry. Inhibition of AKT enhanced the ADIPO effects on p27 protein and prevented LEP‐dependent amelioration of ADIPO effects on p27 protein. Co‐culture of MCF7 cells with adipocytes from lean rats, which secreted low levels of LEP and high levels of ADIPO, increased p27 and decreased cyclin E protein while inducing cell cycle withdrawal, as measured by FACS analyses, in MCF7 cells. Co‐culture with adipocytes from obese rats, which secreted high LEP and low ADIPO, reduced p27 and cyclin E protein levels and induced MCF7 cell cycle entry. Addition of exogenous ADIPO to obese adipocyte co‐cultures inhibited the effects of these adipocytes on MCF7 cell cycle regulation, indicated by an increase in p27 and decrease in cyclin E protein and MCF7 cell cycle withdrawal. Our data suggest that ADIPO and LEP exert opposite effects on mammary cell cycle regulation and that altering the ratio of these adipokines has dramatic effects on MCF7 cell cycle status.
High carbohydrate diets increases the expression of SREBP‐1 in kidney
Authors: Tovar‐Palacio Claudia , Miranda‐Centeno Natalia , Ortiz Victor , Palacios‐Gonzalez Berenice , Cruz Cristino , Palacio Armando R Tovar , Torres Nimbe , Correa‐Rotter Ricardo
Published: June 2021

It has been demonstrated that consumption of high carbohydrate diets are involved in the development of obesity. However, it is not know whether the consumption of specific type of carbohydrates alter lipid metabolism in kidney, and this in turn affect kidney function. Thus the aim of this work was to study whether addition of high fructose or sucrose diets regulates differentially SREBP‐1 expression in kidney, and the metabolic changes occurring in kidney function. Thus, male Wistar rats were fed 60% fructose or sucrose diet for 180d. Weigh gain and food intake were similar. Kidney weight was higher in the fructose group in comparison with sucrose group. However, SREBP‐1 mRNA abundance was similar between both groups, but it was higher that the control groups. In addition, both groups showed higher TNFα expression than the control groups. Interestingly, fructose diet produced the appearance of microcalcifications. These results indicate the high carbohydrates diets affect kidney function.
Isolation of cranberry flavonoids and their relative antioxidant activity.
Authors: Singh Ajay P , Kalk Amanda J , Teo Albert , Vorsa Nicholi , Wilson Ted
Published: June 2021

Polyphenolic compounds in cranberry fruit and juice have been reported to exhibit many pharmacological activities including prevention of urinary tract infection, anticancer and antioxidant activity. Studies characterizating the individual components and their biological activities have been limited by difficulties in isolation of these compounds in their original native chemical state. Crude cranberry fruit polyphenolic extracts were prepared from which proanthocyanidins and flavonols were isolated with semi preparative RP‐HPLC. Spectroscopic methods i.e. UV, IR, electrospray mass spectrometry, 1D‐NMR and 2D‐NMR were used to identify proanthocyanidin monomers, dimers, trimers(PACs), quercetin(Q)‐3‐galactoside, Q‐3‐glucoside, Q‐3‐rhmanoside, myrecetin (M)‐3‐galactoside, M‐3‐rhamnoside, and Q‐3‐O‐(6″‐p‐benzoyl)‐â‐galactoside, the purity of the all above compounds was 99% w/w. Gel electrophoresis and absorption kinetics at 234 nm were used to determine that all of these compounds had an antioxidant activity that protected low density lipoproteins from oxidation by 10 micromolar cupric sulfate in a manner similar to or better than quercetin.
Within‐individual and within‐group correspondence of creatinine‐normalized urinary biomarkers of in vivo oxidation: TBARS and 8‐OHdG
Authors: Orozco Monica N , Solomons Noel W. , Schuemann Klaus , Friel James K.
Published: June 2021

Background:

Urinary biomarkers, such as TBARS or 8‐hydroxy‐d‐guanosine (8‐OHdG), are used in assessment of severe, clinical oxidative stress, but little is known about their diagnostic value within the presumptive normative range.

Objective:

To assess the association between 2 urinary biomarkers of in vivo oxidation (TBARS and 8‐OHdG) in subjects undergoing a supplemental iron‐induced oxidation challenge.

Methods:

Five adult males received two 7‐d courses of: A=120 mg Fe (FeSO4) and B=120 mg Fe + 5 mL vegetable oil. Creatinine‐normalized, urinary TBARS and 8‐OHdG concentrations were quantified in 22 samples from baseline, active supplementation, and washout phases.

Results:

A significant within‐individual correlation between the urinary biomarkers was observed (Spearman r=0.465, p<0.01, n=110); kappa coefficients for the correspondence of tandem interval increments or decrements of the biomarkers concentrations ranged from 0.24 – 0.81 at individuals’ and group levels, with 4 of 6 between 0.40–0.81 (fair to very good).

Conclusions:

Within the normative range, we find intriguing within‐individual and within‐group correspondence between the two urinary biomarkers of in vivo oxidation.

Sponsored in part by the Malaysian Palm Oil Board and INF‐EMF.
Green tea improves hippocampal oxidative status during aging
Authors: Assunção Marco , Santos‐Marques Maria João , Carvalho Félix , Andrade José Paulo
Published: June 2021

Aging is associated with disruption of the redox balance leading to oxidative stress. Studies have suggested that dietary antioxidants may modify cellular redox status. As green tea (GT) contains large amounts of catechins, we intended to examine the effects of its intake on hippocampal formation redox status, a brain region especially prone to oxidative events during aging. Five 12‐month old male Wistar rats were fed with GT as the only liquid source for 7 months and results were compared to those from 12 (C12) and 19 months old (C19) controls. Oxidative markers (protein carbonyls, malondialdehyde, GSH and GSSG) and antioxidant enzyme activities [glutathione reductase (GR), glutathione S‐transferase (GST), Se‐dependent glutathione peroxidase (Se‐GPX) and superoxide dismutase (SOD)] were measured in hippocampal homogenates. GT protected hippocampal proteins and lipids against oxidation and increased GSH and decreased GSSG levels when compared to C19 rats. GR and GST were decreased by GT relatively to C19 group. There was an age‐dependent decrease in Se‐GPX that could not be altered by GT intake, whereas SOD was similar in C12 and C19 rats, being significantly increased after GT treatment. The global results confirm the neuroprotective ability of GT, showing its hippocampal specific action probably due to attenuation of age‐related redox changes. Granted by Unit 121/94 and SFRH/BD/19497/2004 from FCT.
Low concentration of anthocyanin enriched extracts from chokeberry attenuate lipid oxidation of isolated porcine coronary arteries in vitro.
Authors: Bell David Robert , Pape Bryn J , Koritnik Deanna L
Published: June 2021

We have reported previously that impaired endothelium‐dependent, NO mediated relaxation of porcine coronary arteries, resulting from either external or internal superoxide exposure, is prevented by simultaneous exposure of the arteries to chokeberry extract ( 0.05mg total anthocyanin/L). We examined whether this concentration of extract could attenuate generalized oxidation of arterial lipids in vitro. Female porcine coronary artery rings were incubated for 1–2 days in plates of sterile tissue culture media in an O2/CO2 incubator at 37Co. Exposure of rings to exogenous superoxide by pyrogallol or endogenous superoxide by inhibition of Mg/Cu SOD, at levels shown to impair NO mediated coronary relaxation, did not result in detectable accumulation of oxidized tissue lipids as assessed by TBARS formation. Following 2 days incubation of rings in tissue culture media, oxidant stress of rings from a 2hr exposure to 250uM FeSO4+15uM ascorbic acid, shown previously to produce 40% cell toxicity, produced significant formation of arterial TBARS (0.133±0.022 vs. 0.075±0.006, mean/SEM, nmol TBARS/mg prot., n = 4, p<0.05). However, TBARS formation was reduced by 27% in rings exposed to chokeberry (0.05 mgTa/L) for 4 hrs on day 1 of incubation followed by 6 hrs on day 2. We conclude that low concentration of anthocyanin enriched chokeberry extracts, previously shown to protect arterial relaxation from oxidant impairment, also protects coronary arteries from generalized oxidation of membrane lipids. Our results suggest that such extracts may provide protection of coronary arteries from oxidant injury commonly associated with cardiovascular disease.
α‐ and γ‐Tocopherol protect against lipopolysaccharide (LPS) induced hepatic injury in leptin deficient obese mice
Authors: Yeung Steven F , Chung Min‐yu , Flickinger Brent , Bruno Richard S
Published: June 2021

Hepatic steatosis is an obesity‐triggered fatty liver disease in which the liver becomes vulnerable to oxidative insults resulting in nonalcoholic steatohepatitis (NASH). We hypothesized that α‐ or γ‐tocopherol (α‐ or γ‐T) supplementation during hepatic steatosis would decrease the progression towards LPS‐induced NASH. Five‐wk old obese (ob/ob) and lean littermate mice were fed a control, α‐T, or γ‐T supplemented diet (1000 mg/kg) for 5 wk (18 mice/genotype/diet) and then injected with LPS prior to sacrifice at 0, 1.5 or 6 h. Obese compared to lean mice had ∼40% greater (p<0.05) body weight and >3‐times hepatic lipid which were unaffected by Ts or LPS. Obese compared to lean mice had greater hepatic Ts. T supplementation further increased hepatic α‐ and γ‐T by 9.7 and 10.1‐times respectively, compared to respective obese controls. LPS reduced hepatic Ts at 6 h compared to 0 and 1.5 h in obese mice. Obese mice had higher serum alanine aminotransferase (ALT) and α‐ and γ‐T supplementation in obese mice similarly reduced LPS‐induced increases in ALT at 1.5 and 6 h. α‐ and γ‐T supplementation decreased hepatic ascorbic acid (AA) in obese mice and LPS increased AA at 6 h. These data suggest that α‐ or γ‐T protected against LPS‐induced hepatic injury in obese mice likely through a common mechanism not involving AA. Additional study is underway to define the protective mechanism of T supplementation against NASH.
Phytoestrogens protect against ER stress‐mediated neuronal toxicity in SH‐SY5Y cells
Authors: Park Youn‐Jin , Kwon Young Hye
Published: June 2021

Recent studies have suggested that disturbance of endoplasmic reticulum (ER) function in neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease renders neurons more susceptible to dysfunction and death of cell. Phytoestrogens are a diverse group of non‐steroidal compounds that occur naturally in many plants. Although several studies reported the neuroprotective effect of estrogen and phytoestrogens, their underlying cellular mechanisms have not been clear. Therefore, in the present study, we investigated the protective effect of phytoestrogen against ER stress‐induced cell death of SH‐SY5Y cells. 17ß‐Estradiol (10‐9 M) and phytoestrogens (10‐8 M genistein; 10‐8 M diadzein) showed significant protection against tunicamycin‐induced cytotoxicity of SH‐SY5Y human neuroblastoma cells. These neuroprotective effects were blocked by an estrogen receptor (antagonist, ICI 182, 780. Tunicamycin increased expression of the binding protein (Bip) mRNA and the spliced form of X‐box protein (hXbp‐1) mRNA, suggesting that the activation of the unfolded protein response (UPR). Induction of UPR was attenuated when cells were co‐treated with either 17ß‐Estradiol or phytoestrogens. Our results demonstrate that phytoestrogens are potential alternatives to estrogen in the treatment of development of neurodegenerative diseases. This study was supported by a grant from Korea Research Foundation.
The Effect of Soy Supplementation on Human Gut Microflora Community in Post‐Menopausal Women
Authors: Franz Briana , Lasrado Joanne A , Savaiano Dennis A , Nakatsu Cindy H
Published: June 2021

Soy isoflavones and their metabolites can mimic estrogen and thus, may carry health benefits for postmenopausal women as alternatives to hormone replacement therapy. Equol, a metabolite of daidzein, is suggested to be more beneficial, but to date, the bacteria responsible for this conversion have not been identified conclusively. This research was aimed at characterizing changes in the gastrointestinal microflora of post‐menopausal women with the addition of a soy bar to their diet and therein to identify organisms that might be responsible for equol production. Bacterial DNA was extracted from fecal samples collected from 6 women for 14 consecutive days, with women consuming one soy bar/d (160 mg of isoflavones) from day 8–11. Fingerprints of 16S rRNA of the microbial community for the 14‐day study period were generated using PCR‐DGGE. Results indicated that all subjects had stable microbial fingerprint profiles and there appeared to be no clear effect of soy. In contrast, analyses based on bifidobacterial‐specific primers indicated an increase in Bifidobacteria as a function of soy, in most subjects. Also, equol producers had a more diverse bifidobacterial community, even in the absence of soy. Future work will focus on characterizing members of the bifidiobacterial community qualitatively and quantitatively, and determine for the presence of organisms that have been associated with equol production.
Hemoglobin concentrations are inversely associated with erythrocyte folate concentrations in Colombian schoolchildren, especially among children with low vitamin B12 status
Authors: Arsenault Joanne E. , Mora‐Plazas Mercedes , Forero Yibby , Lopez‐Arana Sandra , Baylin Ana , Villamor Eduardo
Published: June 2021

The 2005 National Nutrition Survey of Colombia reported that 38% of schoolchildren were anemic, yet the rate of iron deficiency was 3.6%. To determine if other micronutrients may be responsible for anemia, we examined hemoglobin (Hb) concentrations in relation to serum ferritin, vitamin B12, and vitamin A, and erythrocyte folate (eFol) in 2812 children (5–12 y) from Bogota, Colombia. Mean Hb concentration was 145 (SD, 12) g/L; 4% of children were anemic (Hb <127 g/L) while 3% had low ferritin (<15 μg/L). In multivariate analysis, Hb increased with child's age, mother's age, household's socioeconomic stratum, and family income. Low ferritin was related to 3.6 g/L lower Hb (95%CI=−6.0, −1.3). There was an inverse trend in Hb by quartiles of eFol; the adjusted Hb difference between the highest and lowest eFol quartiles was −6.0 g/L (95%CI=−7.2, −4.9, p for trend <0.0001). This difference was greatest among children with B12 <148 pmol/L (−9.6 g/L), followed by children with B12 148–221 pmol/L (−8.0 g/L), and smallest in children with B12 >221 pmol/L (−5.6 g/L); p for interaction = 0.04. The impact of improving vitamin B12 status on this unexpected inverse relation between folate and hemoglobin should be examined in populations where foodstuffs are fortified with folate alone.

Funding: Harvard DRCLAS, Bogota's Secretary of Education, Colombian National Institute of Health, National University of Colombia