bluuebunny/crossref_metadata_2025 huggingface dataset:
Orchestrating aging across a troubled soma
Authors: Dillin Andrew
Published: November 2023

As an organism ages, its proteins face an increasing severity in the challenges they receive from extrinsic and intrinsic environmental perturbations [1, 2]. Chaperones become dysregulated, while the degradation machineries stop working properly. The protein accumulates damage and starts to misfold. At this point, the cell needs to mount a response to restore its homeostasis; however, the stress response machinery that it typically relies upon when faced with such challenges has lost its capacity to function [1, 2].

This breakdown, however, does not lead to complete disorder. As the organism ages, it exhibits a degree of correlated, recognizable, and predictable changes to its physiology over time. These changes can occur synchronously across multiple tissues and organs. The phenotypic changes of aging occur in a type of concert, rather than in isolation, suggesting the residual participation of the endocrine system in the onset of age‐related phenotypes [3, 4]. The demise of the cell thus most often occurs within the context of the simultaneous demise of the whole organism.

Our lab focuses on the questions of why an aging organism begins to lose control over the integrity of its proteome, and how this loss is communicated across its various tissues. We have taken the unique approach of breaking down a cell into its small and canonically‐autonomous parts – its suborganelles and subcompartments – such that we can take a larger step back to ask how those smaller portions can communicate both with each other and with the organism as a whole. Our approaches have required us to diversify the contexts in which we ask questions: we work on model systems ranging from stem cells and nematodes to mice. We have developed and applied techniques that allow us to manipulate signaling pathways or proteins within a single tissue, cell, or an organelle within a single cell so that we can observe how that small perturbation might reverberate and effect the physiology of the whole of the organism.

In our research, we have found that the stress response pathways that ensure proteome maintenance are not restricted to cell autonomous events, but can be communicated across an organism. We have reported that this is found for the unfolded protein response of the mitochondria (UPRMT), and now find distinct signaling events for the UPR of the endoplasmic reticulum (UPRER) and the cytosolic heat shock response (HSR). Collectively, we have discovered at least three distinct signaling events that report upon proteome form and function across an organism. Our evidence strongly suggests that intracellular and even organelle‐specific stress can be communicated extracellularly via a regulated, endocrine‐like process to impinge on the aging process and health
Targeting mTOR signaling to promote healthy longevity
Authors: Kaeberlein Matt
Published: November 2023

The FDA approved drug rapamycin is a specific inhibitor of mTOR that increases lifespan and healthspan in rodents. Nevertheless, important questions exist regarding the translational potential of rapamycin and other mTOR inhibitors for human aging, and the optimal dose, duration, and mechanisms of action remain to be determined. Here I will report on the effects of short‐term treatment with rapamycin in middle‐aged mice and companion dogs. We find that transient treatment with rapamycin is sufficient to increase life expectancy by more than 50% and improve measures of healthspan in middle‐aged mice. This treatment is associated with a remodelling of the gut microbiome and a dramatic shift in the cancer spectrum of female mice. In dogs, we have defined a dose of rapamycin that is well tolerated, and initial results are consistent with improvements in age‐associated cardiac function. These data suggest that a transient treatment with rapamycin may yield robust health benefits in mice, dogs, and perhaps humans.
Electron cryomicroscopy of rotary ATPases
Authors: Rubinstein John L.
Published: November 2023

Ion‐translocating rotary ATPases serve either as adenosine triphosphate (ATP) synthases, using energy from a transmembrane ion motive force to create the cell's supply of ATP, or as transmembrane ion pumps that are powered by ATP hydrolysis. The members of this family of enzymes each contain two rotary motors: one that couples ion translocation to rotation and one that couples rotation to ATP synthesis or hydrolysis. Our group uses electron cryomicroscopy (cryo‐EM) of single protein particles to study the structures of rotary ATPases. We also work to develop new methods for cryo‐EM to facilitate these studies. Our recent studies have not only illuminated the structures of these fascinating molecular motors at unprecedented resolution, but have also started to uncover their dynamics through computational isolation of the different conformations of the enzymes that exist simultaneously in solution. This lecture will describe the latest structures we have determined for the mitochondrial ATP synthase and proton pumping V‐ATPase, and what we have learned about how these enzymes function and how they interact with molecules that affect their activities.

Support or Funding Information

Canadian Institutes of Health Research, Canada Research Chairs
Innovations in Biotechnology Graduate Education
Authors: Jamison‐McClung Denneal S.
Published: November 2023

Today's graduate students in biotechnology have a range of career options in the public and private sectors, including academia, industry, government and non‐profit organizations. It is not enough to be excellent researchers and university classroom teachers in today's job market; graduate students must develop a suite of transferrable professional skills that transcend STEM disciplines and academic norms.

The trend toward interdisciplinary graduate education and public‐private research collaborations roughly 30 years prompted the formation of the UC Davis Biotechnology Program in 1986, and the subsequent launch of a formal doctoral degree program, the Designated Emphasis in Biotechnology (DEB) in 1997. Since that time the DEB has grown into the largest interdisciplinary degree program on campus, with a “steady‐state” of over 200 students from 29 different disciplines.

Doctoral students see value in the DEB training model, which includes exposure to the “business of biotech”, including bioethics, intellectual property, regulatory affairs, project management and entrepreneurship. Through coursework, seminars, one‐on‐one career mentoring and industrial internships, DEB students gain a thorough understanding of non‐academic STEM career paths and an appreciation for the importance of interdisciplinary “team science” in developing new technologies.

An overarching theme of DEB training is the development of strong communication and professional networking skills. DEB participants are presented with numerous opportunities to hone science communication skills for non‐specialist audiences (e.g. business plan competitions, K‐14 stem outreach, policy brief workshops, etc.), which is key for success in all STEM fields. This talk will elaborate on the mentoring tools and strategies we employ to help DEB doctoral students successfully transition from students to professional colleagues across a range of career paths.
Group Coaching, Grounded in Theory and Evidence, Deployed through the National Research Mentoring Network (NRMN) to Complement Research Mentoring and Increase Diversity
Authors: McGee Richard
Published: November 2023

Biomedical research training has historically relied almost exclusively on mentoring by research advisors as the vehicle for developing the talents of young scientists. Following an apprenticeship model, it affords almost a limitless array of permutations and combinations among mentors and trainees. It also allows for maximum variations in approaches to mentoring. However, it also leads to extreme variability in terms of what is ‘taught’ and opportunities made available to those in training, often leading to unpredictable outcomes, and/or underdevelopment or loss of scientific talent. This potential loss of talent can have especially high impact for individuals from underrepresented groups. As an alternative and complementary approach to more fully develop scientific talent, several variations of group coaching processes have been created and studied. All incorporate both practical and theoretical underpinnings and have established evidence of efficacy, and in one case intensive analysis through a randomized controlled trial. Based on both evidence of impact and theoretical strengths, they are now being expanded beyond their home institutions or limited missions to national impact through the National Research Mentoring Network (NRMN) funded by NIH.

This presentation will highlight the theoretical basis, designs, and impacts to date of 4 different grant writing group coaching models being deployed and compared through NRMN. The presentation will also describe the career coaching group model with an expanded focus beyond grant writing that has evolved from a randomized controlled trial. The refined career coaching model is being tested in collaboration with the American Society for Pharmacology and Experimental Therapeutics (ASPET). All of the coaching models augment and complement research and other mentoring trainees are receiving. The models also all employ coaches who are highly skilled and successful scientists, usually with extensive mentoring experience, who are provided with additional training in the respective group coaching models. The models differ in the time each group operates (ranging from 3–12 months), and the career stages and readiness of participants to be actively writing a proposal. Unique to these group coaching models, they all acknowledge and make visible the underlying social science theories and practices that influence the environments where research training takes place. Evidence to date supports these group coaching models as valuable adjuncts to classical research mentoring, with the ability to positively impact maximal development of research talent and increase contributions from underrepresented groups.

Support or Funding Information

Supported by NIH DP4 GM0096807, R01 GM107701, R35 GM118184, U54 GM119023 and ASPET Big Idea Award
Visualizing DNA Double Strand Break Repair with Single‐Molecule Microscopy
Authors: Loparo Joseph , Graham Thomas , Walter Johannes
Published: November 2023

DNA double strand breaks are an extremely toxic form of DNA damage and must be repaired to maintain genome stability. In human cells the majority of DNA double strand breaks are repaired by nonhomologous end joining (NHEJ), a versatile pathway capable of directly ligating even complicated DNA end structures. This flexibility comes with a price as the NHEJ machinery joins difficult ends in an error‐prone manner. How the NHEJ machinery assembles on DNA ends, holds the ends together and maximizes the fidelity of end joining remain open questions. In this talk I will describe how my laboratory is using single‐molecule imaging approaches in Xenopus laevis egg extracts to follow the repair of double strand DNA breaks in real time with nanometer resolution. We have found that DNA ends pass through at least two distinct synaptic states during repair. Initially ends are tethered in a long‐range synaptic state that requires Ku and DNA‐PKcs. The catalytic activity of DNA‐PKcs along with XLF and XRCC4‐LIG4 are then required to transition the DNA ends into close alignment prior to ligation. In order to understand the role of XLF and XRCC4 in this complex I will describe how we are fluorescently labeling these components and visualizing them during repair.

Support or Funding Information

This work was supported by a National Institutes of Health grant (R01GM115487) to J.J.L.
Targeting epigenetic regulation of malaria blood‐stage infections
Authors: Duraisingh Manoj
Published: November 2023

Epigenetic mechanisms control a variety of critical processes through the life‐cycle of the malaria parasite P. falciparum. In the blood‐stage of infection, this includes antigenic variation of proteins on the surface of parasite‐infected red blood cells that enable sequestration within the host microvasculature and organs, as well as the expression of genes required for transition to the transmissible sexual stage of the parasite. Key histone‐modifying enzymes have been identified as regulators of distinct transcriptional programs underlying these processes. We have focused our research on the histone deacetylases (HDACs) of P. falciparum, that enzymatically remove the acetyl group from histones to regulate transcription of specific gene sets. P. falciparum expresses one class I HDAC, two class II HDACs and two class III HDACs. We have been studying the functions of these HDACs in blood‐stage infections, to establish how they regulate different transcriptional programs and cellular processes in a ‘division of labor’. We are exploring how we can chemically target the essential functions of the P. falciparum HDACs to disrupt and halt proliferation and transmission of this deadly parasite.

Support or Funding Information

Burroughs Wellcome Fund
The role of fatty acid oxidation in cardiac remodeling and acylation
Authors: Ellis Jessica
Published: November 2023

Cardiac mitochondrial metabolism has emerged as a major mediator of cell function and cardiac hypertrophic remodeling, a phenomenon observed in an array of conditions including obesity, diabetes, and hypertension. However, the metabolic and mechanistic drivers of hypertrophy remain elusive. Mitochondrial long‐chain fatty acid oxidation requires carnitine palmitoyltransferase 2 (CPT2) an obligate enzyme of the acyl‐carnitine shuttle. We have generated mice with heart and skeletal muscle‐specific‐CPT2 deficiency (Cpt2M−/−). The loss of heart and muscle CPT2 does not alter whole body energetics and adiposity; however, the Cpt2M−/− mice develop cardiac hypertrophy, dysregulated mitochondrial function, and early lethality. CPT2 deficient hearts do not develop fibrosis and are resistant to rapamycin‐induced alleviation of hypertrophic remodeling. Intriguingly, the hypertrophy occurs in the setting of 50% reduced lysine acetylation across subcellular compartments. Protein acetylation is regulated by fluctuations in mitochondrial metabolism and is a potential mediator of cardiac hypertrophic remodeling. We are exploring the role of protein acetylation in CPT2‐deficiency‐induced cardiac remodeling and mitochondrial function.
Novel Methodological Considerations Regarding the Use of Visual Analog Scale (VAS) Questionnaires to Assess Appetite Control and Satiety
Authors: Douglas Steve M , Gwin Jess A. , Leidy Heather J.
Published: November 2023

Background

VAS questionnaires are commonly used in appetite research to measure postprandial changes in hunger and fullness as markers of subsequent food intake. The current prevalence of smartphone usage provides an opportunistic platform to assess these questions. However, little is known with respect to whether the repetitive use of these questionnaires influence eating behavior or whether novel modifications in their delivery are warranted.

Objectives

To compare VAS appetite and satiety questionnaires delivered through a smartphone application vs. a commonly used computerized program and to test whether the use of these questionnaires alter subsequent eating behavior.

Methods

Twelve healthy young adults (age: 22±1 y; BMI: 22.1±0.9 kg/m2) completed the following randomized crossover design study. On five separate days, the participants came to the facility between 7–9 am and were placed in a room that was void of all time cues. Within 30 min after arrival, they were provided with a 130 kcal preload breakfast containing 30 g protein. During four of the five testing days, the participants completed VAS questionnaires (hunger, fullness, desire to eat, prospective food consumption) every 30 min for 4h using the respective appetite applications (ScaleKit) on an iPod Touch (Apple; Cupertino, CA) or netbook computer application (AVAS; Neurobehavioral Research Laboratory and Clinic; San Antonio, TX). At the end of the 4h periods, the participants were provided with an ad libitum pasta meal to consume until ‘comfortably full.’ To examine the influence of VAS assessment on subsequent eating behavior, no questionnaires were provided over the 4h period on one of the five testing days.

Results

No differences in 4h postprandial hunger, fullness, desire to eat, or prospective food consumption were observed between the smartphone application and the computer program. Additionally, no differences in energy content consumed at the subsequent eating occasions were observed between the days that included the VAS questionnaires (484 ± 50 kcal) vs. no questionnaires (500 ± 53 kcal).

Conclusions

The use of a newly developed VAS smartphone application provides similar measures of reported appetite and satiety compared to a previously validated computer program and the use of VAS questionnaires does not influence subsequent eating behavior.

Support or Funding Information

Internal Funds
Number of Episodes of Food Insecurity in Childhood Directly Impacts Risk of Overweight/Obesity by Eighth Grade
Authors: Mangini Lauren D , Zhu Yeyi , Dong Yongquan , Forman Michele R
Published: November 2023

Objective

Obesity and food insecurity represent significant public health challenges, yet their association in childhood is unclear. Our objective is to examine the relationship between the number of episodes of household food insecurity in early and mid‐childhood and risk of overweight/obesity in eighth grade.

Methods

In the prospective Early Childhood Longitudinal Study‐Kindergarten cohort, food insecurity, measured with the validated USDA 18‐item module, was quantified in episodes per year/wave, and examined across four waves. Anthropometrics were measured to calculate age‐ and sex‐specific BMI z‐scores categorized as normal or overweight/obese. BMI trajectory was analyzed by sex and episodes of food insecurity. Sex‐specific multivariable Poisson regression models estimated relative risks (RR) and 95% confidence intervals (CI) for overweight/obesity at the eighth grade, adjusting for covariates.

Results

BMI trends differed by sex and episodes of food insecurity. Compared with the food‐secure, boys with food insecurity ≥3 times had a 44% (95% CI 1.09, 1.92) higher risk of overweight/obesity at the eighth grade; and twice food‐insecure girls had a 50% (95% CI 1.10, 2.06) higher risk. Racial disparity in overweight/obesity risk only emerged among girls. High birthweight was associated with an increased risk of overweight/obesity regardless of sex, whereas low birthweight was associated with a decreased risk among girls.

Conclusions

Exposure to food insecurity predicted a higher BMIZ and was positively associated with risk of overweight/obesity dependent on sex and number of episodes of food insecurity. The American Academy of Pediatrics recommendation to screen for food insecurity is timely and may inform obesity prevention.

Support or Funding Information

This research did not receive any specific grant from funding agencies in the public, commercial, or not‐for‐profit sectors. Ms. Mangini and Dr. Forman are supported by the David Bruton, Jr. Centennial Professorship funds. David Bruton, Jr. had no role in the design, analysis or writing of this article.
The Influence of Hydromineral Balance on Mood in Humans: A Randomised Controlled Trial
Authors: Young Hayley Anne , Cousins Alecia , Benton David
Published: November 2023

Regular salt intake is required for the maintenance of mineral ‐ fluid balance, although excessive intake is pathophysiological. Humans typically consume vastly more salt (sodium chloride) than is physiologically required yet the introduction of policies to reduce intake have met with only limited success. Despite this, the antecedents of salt intake are under investigated. An animal literature suggests that reducing salt increases anxiety, stress, or depression, however, human data are sparse. The aim was to determine in humans whether the consumption of salt, with or without water influenced mood. 100 young adults were exposed to a temperature of 30°C for four hours. In a 2 × 2 design participants either did or did not drink two 150ml glasses of water with either a sodium chloride (150mg) or placebo capsule. Changes in mood, thirst, body temperature, and body weight and urine osmolality were monitored. Participants reported being more energetic, more agreeable, and less depressed when they consumed salt. In addition, when participants consumed water they were less fatigued, more agreeable and less depressed. With anxiety there was a Salt × Water interaction; consuming salt resulted in a less anxiety but only in those who also consumed water. Neither salt nor water influenced ratings of confusion or confidence. These findings represent the first experimental data in humans supporting an influence of hydromineral balance on mood.
MicroRNAs in the Pathogenesis of Lipogenic Diet Induced Hyperlipidemia and Insulin Resistance
Authors: Su Qiaozhu , Sud Neetu , Pan Kaichao
Published: November 2023

Fructose is a highly lipogenic sugar which can alter energy metabolism and trigger metabolic disorders. MicroRNAs (miRNAs) are noncoding RNAs with a length of 19 to 25 nt and are involved in posttranscriptional gene regulation by binding to the 3′‐untranslated regions of their target mRNA and impacting diverse cellular processes, such as metabolic inflammation and energy metabolism. Regulation of miRNAs is tissue and cell type specific in which a single miRNA can target numerous mRNA sequences and each mRNA can be targeted by multiple miRNAs. This unique regulatory property enables miRNAs to simultaneously regulate several groups of mRNAs within a signaling pathway or network and generate powerful impact on diverse cellular processes. Thus, identification of miRNA expression profiles and their relevant target genes offers great potential to delineate the molecular pathogenesis of metabolic diseases. In this study, our objective was to comprehensively explore the regulatory roles of miRNAs in the onset of hyperlipidemia and insulin resistance induced by high fructose. Determination of the miRNA profile by illumina small RNA sequencing identified a set of miRNAs (forty six miRNAs) in mouse livers whose expression profiles were significantly altered by high‐fructose feeding. Among them, nineteen miRNAs were significantly upregulated whereas the other twenty six were downregulated compared to the control chow‐fed mice. Computational prediction and functional analysis further revealed that ten of these miRNAs, including miR‐19b‐3p, miR‐101a‐3p ‐3p, miR‐30a‐5p, miR‐223‐3p, miR‐378a‐3p, miR‐33‐5p, miR‐145a‐3p, miR‐128‐3p, miR‐125b‐5p and miR‐582‐3p, assembled as a regulatory network that collaboratively and repeatedly targets multiple key metabolic signaling molecules involved in inflammatory stress (e.g., PPARα and LXRα), lipid and lipoprotein metabolism (e.g., SREBP‐1/2 and apoB), and insulin signaling (e.g., IRS‐1 and FOXO1). Quantitative real‐time PCR analysis further confirmed that alterations of miRNAs were associated with the changes of the mRNA abundances of their target genes, indicating the pathogenic impact of the altered miRNAs on fructose induced metabolic disorders. Genetic depletion of miR‐378a protected mice from fructose induced insulin resistance whereas overexpression of miR‐378a resulted in inflammatory stress in hepatocytes. In conclusion, our study unveils a novel hepatic miRNA regulatory network that was altered by high‐fructose feeding. Manipulating the abundance of the key miRNAs in this network prevents the onset of hyperlipidemia and insulin resistance induced by high‐fructose diet. This novel finding provides mechanistic insights into the interaction between miRNAs and their target genes in the development of metabolic syndrome. It may further provide rationale for pharmaceutically targeting these miRNAs in the prevention and treatment of nutritional associated metabolic diseases.

Support or Funding Information

P20 GM104320‐01A
Barriers to Healthcare Seeking and Provision Among African American Adults in the Rural Mississippi Delta: Community and Provider Perspectives
Authors: Connell Carol , Yadrick Kathy , Wang Sherry
Published: November 2023

The objective of this project was to identify barriers to healthcare seeking and healthcare provision among rural African American adults in the Mississippi Delta from the perspective of volunteer community health advisors (CHAs), community residents, and healthcare providers. Ten focus groups (20 males, 37 females) were conducted with CHAs and community residents from nine counties in one public health district. An additional focus group was conducted with healthcare providers (3 males, 2 females, 4 African American, 1 Other) from medical clinics and a hospital located in the same public health district. Two key informant interviews were also conducted with a district public health officer and a chairman of a local health advocacy foundation board of directors. All interviews were transcribed and data were analyzed using the constant comparative method to identify major themes and sub‐themes related to barriers to healthcare seeking and provision. Findings were broadly categorized as structural and interpersonal barriers with structural barriers encompassing issues of poverty (unemployment/underemployment), lack of health insurance, rurality (such as lack of transportation and medical specialists), perceptions of racism, and medical mistrust. Interpersonal barriers included fear of a serious medical diagnosis, gender socialization (going to the doctor as a sign of weakness among men) and age (not going to see the doctor until age 50 for first screening). Differences also emerged in the perceptions between community members and healthcare providers. While both groups were critical of medical insurance, providers viewed insurance guidelines as restricting their ability to provide the most current treatment. Community members and some CHAs viewed providers as conspiring with insurance and pharmaceutical companies to receive “kick‐backs.” Additionally, whereas racism emerged as a major structural barrier in the community interviews, this topic was not mentioned in any of the provider interviews. Results indicate significant efforts are needed to overcome both structural and interpersonal barriers to healthcare seeking and provision in order to reduce health disparities.

Support or Funding Information

This project was funded through a Patient‐Centered Outcomes Research Institute (PCORI) Eugene Washington PCORI Engagement Award (1514‐USM). The statements presented in this abstract are solely the responsibility of the authors and do not necessarily represent the views of PCORI, its Board of Governors or Methodology Committee.
Dietary fat/cholesterol‐sensitive PKCbeta‐RB signaling: Potential role in diet‐induced NASH/HCC axis
Authors: Mehta Devina , Sif Said D , Jacob Samson T , Ghoshal Kalpana D , Mehta Kamal Deep , Huang Wei
Published: November 2023

Hepatocellular carcinoma (HCC) is a frequent form of cancer with a poor prognosis. Recent studies suggest that abnormal lipid metabolism may play an essential role in nonalcoholic steatohepatitis (NASH) development and oncogenesis of HCC. Excess dietary cholesterol intake has been shown to cause development of experimental NASH in different animal models, especially in the setting of a concurrent high‐fat diet. Despite knowledge that Western‐style high‐fat and high‐cholesterol diet is a risk factor in the development of NASH and subsequent progression to HCC, diet‐induced signaling changes implicated in NASH/HCC axis are not well understood. Understanding molecular mechanisms altered by diet is crucial for developing preventive and therapeutic strategies. We previously assessed whether metabolic adaptation to high‐fat/cholesterol diet is associated with changes in hepatic PKCβ expression and also studied the consequence of PKCβ deficiency on diet‐induced hepatic cholesterol homeostasis. We reported that diets enriched with high‐fat and high‐cholesterol (with or without bile acid), shown to produce NASH and HCC, induce hepatic PKCβ expression, and a systemic loss of PKCβ promotes hepatic cholesterol accumulation in response to such diets. These results support the possibility that PKCβ is a physiological transducer of dietary fat/cholesterol and plays a critical role in hepatic adaptation to such diets. Here, we sought to determine how PKCβ and diet functionally interact during tumorigenesis. We examined effects of dietary fat/cholesterol on the PKCβ phosphorylation of retinoblastoma (RB) protein and family members, as well as compared PKCβ expression in human HCC versus normal tissue. We show that diet‐induced hepatic PKCβ expression is accompanied by increased phosphorylation of specific residues of RB protein in a time‐dependent manner. Intriguingly, PKCβ−/− livers exhibited reduced phospho‐RB and RB protein levels, which ultimately resulted in increased transcription of RB gene. It is also accompanied by reduced RBL‐1 with no significant effect on RBL‐2 protein level. To investigate the potential effect of PKCβ deficiency on DNA content of preneoplastic livers, flow cytometric analysis was conducted on hepatocytes obtained from high‐fat/cholesterol diet‐fed WT and PKCβ−/− mice. We also report reduced expression of PKCβ in HCC compared to an adjacent non‐tumorous liver in human patients. These results raise an interesting possibility that diet‐induced PKCβ activation represents an important mediator in the functional wiring of cholesterol metabolism and tumorigenesis through modulating stability of cell cycle‐associated proteins. Identification of PKCβ as a cellular relay in diet‐mediated change in RB functions can define the signaling events that could participate in diet‐induced oncogenesis.

Support or Funding Information

The Ohio State University College of Medicine Research Funds
Reduced Leucine Availability Inhibits the Growth of Bone Sarcomas by Stimulating the Fuel Sensing Enzyme AMPK
Authors: Martin Shailer , Boyer Michael , Ananieva Elitsa
Published: November 2023

Bone sarcomas are tumors that commonly originate from the bone and the cartilage. Although rare, bone sarcomas are associated with high mortality in children and adolescents due to their unresponsiveness to traditional treatments. One novel approach to address this resistance is to explore the role of leucine metabolism in bone sarcoma cellular proliferation and protein synthesis. The essential amino acid, leucine, stimulates protein synthesis via complex 1 of the mammalian target of rapamycin (mTORC1) and is thus important for cell growth and proliferation. The intracellular concentrations of leucine are regulated at the level of leucine degradation. The first step in leucine degradation is the reversible transamination of leucine catalyzed by the mitochondrial (BCATm) and the cytosolic (BCATc) branched chain aminotransferases. The objective of this research was to explore whether changes in leucine availability enforced by inhibition of leucine uptake or leucine degradation would impact the growth and protein synthesis of the human bone sarcoma cell line 143B. We hypothesized that the leucine antagonist, N‐acetyl‐leucine‐amide (NALA), would inhibit the cellular growth and protein synthesis of the bone sarcoma cells, while the BCATc inhibitor, gabapentin, would have an effect opposite to that of NALA, through the inhibition of leucine degradation. To test this hypothesis, we treated 143B cells with different concentrations of NALA (0,12.5, 25, and 50mM) or gabapentin (0, 5, and 50mM) for twenty‐four hours, and measured the following: cellular growth, protein content, and the activation of mTORC1 and the fuel‐sensing enzyme AMP‐activated protein kinase (AMPK). Our results revealed that both NALA and gabapentin inhibited the bone sarcoma cellular growth and protein content in concentration dependent manner. However, while NALA stimulated AMPK, gabapentin inhibited AMPK, as evidenced by changes in the phosphorylation of AMPK. The observed changes in AMPK indicate that leucine may impact the energy status and the growth of bone sarcomas by modulating the activation state of AMPK. Because activation of AMPK inhibits anabolic processes and cancer growth, a therapeutic approach aimed at reducing leucine availability may be one novel solution to treat bone cancer patients.

Support or Funding Information

IOER ‐startup, Des Moines University (Ananieva, EA)
Folic acid content of diets during pregnancy imprint early post‐partum hepatic methyl‐metabolism and insulin resistance in Wistar rat dams
Authors: Pannia Emanuela , Ho Mandy , Yang Neil , Chatterjee Diptendu , Hammoud Rola , Kubant Ruslan , Anderson G. Harvey
Published: November 2023

Intake recommendations for folic acid (FA, synthetic form of folate) are often exceeded by 2.5–7‐fold in North America, raising concern for its potential adverse effects on maternal and child health. In Wistar rats, high (10×) but non‐toxic FA intakes during pregnancy lead to obesity, insulin resistance and dysregulation of central and peripheral energy metabolism‐related genes in both offspring and dams later‐in‐life. Moreover, high FA fed to rat offspring post‐weaning was reported to induce inhibitory effects on hepatic methyl‐metabolism, limiting the conversion of FA to its biologically active form methyltetrahydrofolate (MTHF). This study examined the effects of dose of FA in maternal diets on early post‐partum phenotype (body weight and food intake), folate status, methyl metabolism in liver, and insulin resistance in the dams.

During pregnancy, Wistar rats (n=12/group) were fed an AIN‐93G diet containing five levels of FA: 0× (deficient), 1× (recommended, 2mg FA/kg), 2.5× (moderate), 5× (high) and 10× (very high). Dams were fed the recommended diet during lactation and their first week post‐weaning and then terminated. At 1‐week post‐weaning, mRNA expression of methyl metabolism‐related genes in liver, including folate receptor (FolR), Mthf reductase (Mthfr), betaine‐homocysteine S‐methyltransferase (Bhmt) and methionine synthase (Mtr) were assessed by real‐time qPCR. Unmetabolized FA and folate metabolites were analyzed in blood and liver by high performance liquid chromatography (HPLC). Fasting plasma glucose and insulin levels were measured, and insulin resistance was evaluated via surrogate index: the homeostatic model assessment insulin resistance (HOMA‐IR).

The results show a lasting effect of the diets consumed during pregnancy on the dams four weeks after giving birth. Dams fed 0X, 5× and 10X‐FA during pregnancy had lower hepatic mRNA expression of Mthfr (2.2‐fold, p<0.0001) and Mtr (3.5‐fold, p<0.001) compared to control and showed no change in folate status in liver. However, deficient and very high FA maternal diets led to higher MTHF in blood compared to control suggestive of dysregulation of one‐carbon pathways. Dams fed 5X‐FA also showed higher plasma insulin (p<0.01) and HOMA‐IR (p<0.05) then dams fed the control diet, indicative of the development of insulin resistance. Body weight, food intake and unmetabolized FA levels were not affected by maternal diets at 1‐week post‐weaning.

In conclusion, deficient or excess FA in diets consumed during pregnancy imprinted methyl‐metabolism and insulin regulation in the dam to 1‐week post‐weaning, which may contribute to their long‐term adverse effects as previously found in the dams.

Support or Funding Information

Canadian Institute of Health Research, Institute of Nutrition, Metabolism and Diabetes (CIHR‐INMD), Reference MOP‐130286
School nutrition programs and policies, dietary intake, and obesity: The Healthy Communities Study
Authors: Au Lauren E , Woodward‐Lopez Gail , Gurzo Klara , Kao Janice , Crawford Patricia , Ritchie Lorrene D
Published: November 2023

The study objective was to examine the association between the school nutrition environment and children's dietary intake and weight status in an observational sample of 5,138 U.S. children ages 4–15 years recruited from 130 communities in the Healthy Communities Study. The study includes information obtained on school characteristics (school participation in state and federal nutrition programs, school wellness committee and coordinator, and district food‐related school wellness policies), measurements of children's dietary practices (dietary screener and dietary behaviors related to child obesity), and measured child height and weight to calculate BMI z‐score. Hierarchical statistical models were generated to relate school nutrition policies and programs to dietary outcomes and BMI z‐score, adjusted for individual‐level covariates (e.g., child race/ethnicity, household income, maximum parent education, maximum parent employment), community covariates (e.g., region, minority status, urbanicity), and school and community level clustering. Children in schools where wellness committees were more active, i.e. met at least once in the past year, compared to children in schools where wellness committees were less active, i.e. met less than once per year, children had 0.10 lower BMI z‐scores (95% CI: −0.17, −0.02; P=0.02) and consumed breakfast on 0.14 more days/week (95% CI: 0.02, 0.25; P=0.02). Schools with farm to school programs compared to schools without such programs had children with a lower frequency of intake of energy dense foods by −0.19 times/day (95% CI: −0.33, −0.05; P=0.01). The presence of the USDA's Team Nutrition Initiative also was associated with an increase in children's intake of 0.14 servings/day of fruits and vegetables (95% CI: 0.00002, 0.14; P=0.05) compared to schools that did not have the program. In pair‐wise comparisons (at a 5% procedure‐wise error rate), schools with wellness committees that met more than once in the past year compared to schools with wellness committees that did not meet, children had significantly lower added sugar intake (−0.78 tsp/day) and significantly lower sugar intake from sugar‐sweetened beverages (−0.43 tsp/day). Overall, improved child diet and weight outcomes were found when schools had an active wellness committee, involvement in a farm to school program, and/or participated in the USDA's Team Nutrition Initiative.

Support or Funding Information

Supported by: NHLBI #1K01HL131630 and RWJF HER #73272.
Serum Alkylresorcinols as Biomarkers of Dietary Gluten Exposure in Celiac disease
Authors: Ross Alastair , Choung Rok Seon , Marietta Eric V , Van Dyke Carol T , Murray Joseph A
Published: November 2023

Background

Therapy for celiac disease (CD) mainly relies on following a gluten‐free diet (GFD); however, a serum marker for gluten intake has yet to be established.

Aims

To evaluate the utility of alkylresorcinol concentrations for detecting gluten intake in studies of human and mouse.

Methods

Alkylresorcinol concentrations were compared among treated CD patients (n=34), untreated CD patients (n=36), and controls (n=33). Furthermore, 7 additional CD patients whose serum samples were available at diagnosis and after GFD were evaluated. In mice studies, alkylresorcinol concentrations were compared in the serum of 5 mice fed a regular chow and 10 mice fed lifelong with a gluten‐free chow. In addition, the effect of adding gluten on changes of alkylresorcinol concentrations was also evaluated.

Results

Total alkylresorcinol concentrations were significantly lower in treated CD patients (median [IQR], 3 (2–8) nmol/L), compared to untreated CD patients (median [IQR], 32 [11–74] nmol/L; P<.0001) or healthy controls (median [IQR], 54 [23–112] nmol/L; P<.0001). Moreover, alkylresorcinol concentrations in CD patients significantly decreased after introduction of a GFD (median, 34 nmol/L at diagnosis vs. 5 nmol.L after GFD, p=0.02). In the mice, median (IQR) total alkylresorcinol concentrations in serum samples of mice fed lifelong with a gluten‐free chow was 1.8 (1.6–2.3) nmol/L, which was further significantly increased to 16 (11–22) nmol/L after 8 days of feeding with the gluten free chow that had gluten added to it. (p=.008).

Conclusion

Serum alkylresorcinol concentrations could be a useful marker for dietary gluten in CD.

Support or Funding Information

No funding to report.
Differences in Nutritional Intake and Bone Health Among Adults With and Without Celiac Disease: Data From The National Health and Nutrition Examination Survey, 2009–2012
Authors: Habel Lara , Frankenfeld Cara L. , Gallo Sina , Moshfegh Alanna J. , Slavin Margaret
Published: November 2023

Background

Celiac disease is a gastrointestinal malabsorptive disorder characterized by intestinal villous atrophy and triggered by an autoimmune response to gluten, leading to malnutrition and secondary conditions including osteoporosis. There is still a scarcity of information on the nutritional intake of adults with celiac disease as it relates to their bone health.

Objective

To evaluate differences in nutritional intake of calcium, vitamin D, and phosphorus; serologic concentrations of these nutrients; and bone health among adults with and without celiac disease.

Design

Cross‐sectional data was retrieved from the National Health and Nutrition Examination Survey (NHANES) cycles 2009–10 and 2011–12. Data including self‐reported dietary and supplement intake from 24‐hour recalls, serologic nutrient status, and dual x‐ray absorptiometry (DXA) scans were collected from 34 serologically positive (EMA+) adults with celiac disease. The participants were an average age of 43 years old (range 20–74 years). Results were compared with those of 9,496 control subjects using multiple linear regression modelling controlled for age, sex, and race/ethnicity.

Results

Adults with celiac disease consumed significantly more total calcium (Ca) and phosphorus (P) than the control group (1514 mg Ca/day vs. 1165 mg Ca/day, p = 0.008, and 1726 mg P/day vs. 1429 mg P/day, p = 0.022). They had significantly higher serum phosphorus concentrations than the controls (4.0 vs. 3.7 mg/dL, p = 0.008). No differences in serologic concentrations of calcium or 25(OH)D were identified. Lower bone mineral density (BMD) of the femoral neck was found in the adults with celiac disease than the controls (0.768 g/cm2 vs. 0.834 g/cm2, p = 0.049).

Conclusion

Despite greater overall calcium and phosphorus intake, adults who tested positive for celiac disease (EMA+) had lower overall bone mass than adults without celiac disease.
Decreased Blood Lactate Concentration with Twenty‐Eight Days of Mushroom Blend Supplementation
Authors: Dudgeon Wes , Thomas D. David , Dauch William , Scheett Timothy
Published: November 2023

Objective

Dietary supplement research in animal models has suggested various strains of mushrooms, specifically Cordyceps militaris, can improve physical performance. In this study our aim was to to determine the effects of the commercially available supplement Peak O2 (Compound Solutions, USA), a blend of six mushrooms which includes Cordyceps militaris, on indices of maximal and submaximal aerobic performance following 14 and 28 days of supplementation.

Methods

Twenty‐three individuals (Mean ± standard deviation, Age = 21.4 ± 2.1 yrs, Height = 170.3 ± 7.7 cm, Body Mass = 70.8 ± 12.2 kg) participated in this randomized, blinded, placebo‐controlled study. The treatment group (M, n=12) was given 2.0 g·day−1 of mushroom blend with Gatorade (2.0 g) for flavor enhancement while the placebo group (P, n=11) received 2.0 g·day−1 color‐matched flour with Gatorade (2.0 g) for 28 days. A graded maximal cycle ergometer test was used to evaluate maximal oxygen consumption (VO2max), time to exhaustion (TTE) and heart rate recovery (HRr). The second stage of this protocol was maintained for five minutes (economy phase) to allow subjects to reach true steady state and submaximal oxygen consumption (VO2) and blood lactate concentration (BL) were assessed at the conclusion of this phase prior to subjects progressing to the next phase. Testing was conducted following 14 and 28 days of supplementation.

Results

Dependent measures t‐tests were used to evaluate changes within groups compared to baseline values. There were no changes in VO2max or TTE for either group. During the economy phase, BL decreased significantly in M after 14 days (p = 0.03) when compared to baseline and 28 days (p = 0.02) of supplementation (baseline: 2.50 ± 0.59 mmol·L−1, 14 days: 2.39 ± 0.50 mmol·L−1, 28 days: 2.21 ± 0.54 mmol·L−1). There were no changes in BL economy in the P group (pre 2.29 ± 0.7 mmol·L−1, mid 2.21 ± 0.3 mmol·L−1, post 2.32 ± 0.7 mmol·L−1).

Conclusion

These data suggest that twenty‐eight days of supplementation with 2.0 g·day−1 of Peak O2 may lower blood lactate concentration at submaximal intensity in young, apparently healthy individuals. The results offer the possibility that Peak O2 supplementation may decrease anaerobic metabolic stress during submaximal aerobic exercise.

Support or Funding Information

Partial support for this work was provided by Disruptive Nutrition, LLC.
Dose‐response Effects of Soybean Oil in Salad Dressing upon the Bioavailability of Carotenoids/Fat‐soluble Vitamins in Salad Vegetables
Authors: White Wendy S , Zhou Yang , Crane Agatha , Dixon Philip , Quadt Frits , Flendrig Leonard M
Published: November 2023

Research is needed to quantify the dose effect between added vegetable oil and carotenoid/fat‐soluble vitamin absorption from vegetables. The objectives were to evaluate the dose‐response relation between the amount of soybean oil in salad dressing and the absorption of: 1) carotenoids, phylloquinone, and tocopherols in salad vegetables; 2) retinyl palmitate formed from the provitamin A carotenoids, α‐ and β‐carotene. Women (n = 12) each consumed 5 equivalent salads containing grated carrots, cherry tomatoes, romaine lettuce and spinach. The salads with salad dressings containing 0, 2, 4, 8, or 32 g phylloquinone‐ and tocopherol‐stripped soybean oil were consumed in randomly assigned order and separated by ≥ 2 wk. The plasma chylomicron fraction was isolated from blood samples collected at baseline and 2, 3.5, 5, 7, and 9.5 h postprandially. Across the entire 0 – 32 g range, the amount of soybean oil in salad dressing was linearly related to the plasma chylomicron area under the curve (AUC) values for α‐carotene, lycopene, phylloquinone, and retinyl palmitate. Across a more limited 0 – 8 g range of soybean oil, there was a linear increase in the chylomicron AUC values for β‐carotene. The absorption of all carotenoids and fat‐soluble vitamins was highest with 32 g ingested oil (P < 0.002). For the carotenoids/fat‐soluble vitamins that showed a linear response, the slope β (soybean oil effect) varied widely between subjects. In conclusion, soybean oil in salad dressing promoted the absorption of all carotenoids and fat‐soluble vitamins from salad vegetables. For a large salad, maximal absorption required more than 8 g and up to 32 g or more of soybean oil. Linear models could be used to predict the relation between the amount of soybean oil and the absorption of α‐ and β‐carotene, lycopene, and phylloquinone, as well as that of the provitamin A conversion product, retinyl palmitate.

Support or Funding Information

Supported by Unilever R&D, Vlaardingen, the Netherlands