bluuebunny/crossref_metadata_2025 huggingface dataset:
Phytosterols Have Limited Direct Effect on Hepatocyte Transporter Expression but Synergize with Endotoxin to Enhance Kupffer Cell Inflammatory Response
Authors: Guthrie Gregory , Tackett Bryan , Stoll Barbara , Martin Camilia , Burrin Doug
Published: November 2023

Phytosterols, non‐nutritive components of soybean oil‐based lipid emulsions (SO), have been implicated in the development of parenteral nutrition associated liver disease (PNALD). Phytosterols may drive the pathogenesis of PNALD through a two‐hit mechanism: suppression of hepatic bile clearance through downregulation of the bile salt export pump (BSEP) and increased hepatic inflammation. Inflammation can further suppress BSEP and potentially the ATP‐binding cassette transporters ABCG5/8, the hepatic phytosterol clearance transporter, creating a feed‐forward loop leading to further hepatic injury. Two nuclear hormone receptors, Farnesoid X Receptor (FXR) and Liver X Receptor (LXR) regulate bile acid metabolism and have been shown to suppress the inflammatory response. The aim of our study was to first, determine if the hepatic transport dysfunction and inflammatory response is hepatocyte independent or requires activation of the resident macrophages, Kupffer cells; second, determine if ligand‐mediated activation of FXR and LXR can restore inflammation‐induced suppression of transporter function. Preterm piglets were administered parenteral nutrition for 10 d containing SO lipid emulsion. On day 10, piglets were given an 8‐h infusion of saline or LPS (10 μg*kg−1*h−1). In a separate experiment, primary hepatocytes and Kupffer cells were isolated from neonatal piglets. Cells were treated with media supplemented with 1% SO with or without the addition of a phytosterol mixture containing β‐sitosterol, stigmasterol, and campesterol. After incubation for 24 h, cells were additionally treated with FXR ligand Obeticholic acid (OCA), or LXR ligand GW3694 in the presence or absence of 50 ng/mL LPS or 10 ng/mL IL‐1β for 24 h. In piglets, administration of LPS lead to a significant suppression of BSEP and ABCG5/8 expression compared to saline infused piglets. In cell culture, administration of IL‐1β, but not LPS or phytosterols, led to suppression of both BSEP and ABCG5/8. In hepatocytes co‐treated with IL‐1β and OCA or GW3694, only BSEP expression was rescued. In Kupffer cells, phytosterols alone failed to activate expression of cytokines, however, when treated with both LPS and phytosterols increased cytokine expression significantly more than with LPS alone. From this study, we conclude inflammation can suppress the transporters for bile acid and phytosterol clearance. Our in vitro data shows that Kupffer cells are susceptible to enhanced activation of cytokine expression by phytosterols when cells are primed with LPS. These results suggest that phytosterols may contribute to the progression of liver disease through inflammation.

Support or Funding Information

American Society of Parenteral and Enteral Nutrition Rhoads Research Foundation, National Institute of Health Grant DK‐094616
Vitamin A Supplementation Redirects the Flow of Retinyl Esters from Peripheral to Central Organs in Neonatal Rats Raised under Vitamin A‐Marginal Conditions
Authors: Hodges Joanna K. , Tan Libo , Green Michael H , Ross A. Catharine
Published: November 2023

Background

Vitamin A (VA, retinol) supplementation is used to reduce child mortality in countries with high rates of malnutrition. Existing research suggests that neonates (<1 mo old) may have a limited capacity to store VA in organs other than the liver; however, the knowledge about VA distribution and kinetics in individual non‐hepatic organs is limited.

Objective

We examined retinol uptake and turnover in non‐hepatic organs, including the skin, brain and adipose tissue, in neonatal rats without and after VA supplementation in the amount equivalent to that which has been given to human infants.

Methods

Sprague‐Dawley neonatal rats (n = 104) were nursed by mothers fed a VA‐marginal diet (0.35 mg retinol/kg diet) and treated on postnatal day (P) 4 with an oral dose of either VA (6 μg retinyl palmitate/g body weight) or canola oil (control), both containing 1.8 μCi of [3H]retinol. Subsequently, pups (n = 4/group/time) were euthanized at 13 times from 30 min to 24 d after dosing. The fractional and absolute transfer of chylomicron retinyl esters (CM‐REs), retinol‐binding protein‐bound retinol (RBP‐ROH) and total retinol were estimated in WinSAAM.

Results

VA supplementation redirected the flow of CM‐REs from peripheral to central organs and accumulated mainly in the liver. The RBP‐ROH released from the liver was acquired mainly by the peripheral tissues but not retained efficiently causing repeated recycling of retinol between plasma and tissues (541 vs. 5 times in the supplemented vs. control group) and its rapid turnover in all organs, except the brain and white adipose tissue. Retinol stores in the liver lasted for ~2 weeks before being gradually transferred to other organs.

Conclusions

Vitamin A supplementation administered in a single high dose during the first few days after birth is readily acquired but not retained in the peripheral tissues of neonatal rats suggesting that a more frequent, lower‐dose supplementation may be necessary to maintain adequate VA levels in the rapidly developing neonatal organs.

Support or Funding Information

Supported by NIH grant HD‐066982
Activating β‐catenin mutations and PI3KCA synergize to promote lipogenic liver tumors in mice
Authors: Tao Junyan , Zhan Na , Singh Sucha , Chen Xin , Monga Paul
Published: November 2023

In a previous study, we showed co‐expression of hMet and mutant beta‐catenin (S33Y, S45Y) in mouse liver using the sleeping beauty transposon/transposase (SB) delivered via hydrodynamic tail vein injection (HTVI) led to Hepatocellular cancer (HCC) which mimicked 10% of HCC patients by transcriptomic analysis. Since PI3KCA activation can occur downstream of hMet signaling, we co‐expressed H1047R‐mutant‐PI3KCA and β‐catenin mutants (S33Y or S45Y) using SB and HTVI. HCC was evident at 15 weeks post HTVI in the H1047R‐PI3KCA/S45Y‐β‐catenin group and at 22 weeks in the H1047R‐PI3KCA/S33Y‐β‐catenin group as compared to 6–7 weeks in hMet‐mutant‐β‐catenin studies. This delay in tumor development suggests that PI3KCA activation downstream of hMet may not be an important contributor to the hMet/beta‐catenin induced HCC. Intriguingly, all tumor cells in the PI3KCA/mutant‐β‐catenin mice displayed notable lipid accumulation. This suggests some unique features of PI3KCA and β‐catenin cooperation in HCC development. Further, introduction of dominant‐negative (dn) TCF4 at the time of PI3KCA/mutant‐β‐catenin HTVI prevented tumorigenesis. Intriguingly, co‐injection of dnTEAD2 prevented HCC in H1047R‐PI3KCA/S33Y‐β‐catenin and H1047R‐PI3KCA/S45Y‐β‐catenin model but no effect on hMet and mutant beta‐catenin model. Thus, PI3Kinase and β‐catenin cooperation results in HCC with unique characteristics such as lipogenic features and signaling involving Yap signaling. Also, the rate of tumorigenesis is notably slower than hMet‐β‐catenin model. All these findings suggest that PI3KCA is not downstream of hMet in cooperating with β‐catenin to induce HCC.
Unraveling the mechanism of ER‐associated organelle fission
Authors: Voeltz Gia K.
Published: November 2023

ER membrane contact sites (MCSs) define the position where early and late endosomes undergo constriction and fission. ER tubules are recruited to the divide between cargo sorting domains on endosomes that will then constrict and undergo fission. Our aim was to purify ER factors that regulate MCS formation and fission in animal cells. Based on the identity of the candidate proteins, we hope to be able to test hypotheses about the mechanisms used by the ER to drive organelle constriction and division at MCSs. Our strategy to identify MCS proteins was to target a promiscuous biotin ligase (BirA) to ER‐associated fission sites. BirA has a modification reach to approximately 30nm, which is ideal for bridging membrane contacts (which have a typical spacer distance of ~5–15nm). Our hybrid construct localizes as predicted and biotinylates ER proteins at MCSs in mammalian cells that we could purify and then identify by mass spec. This strategy has identified ER proteins that regulate ER‐associated endosome fission.
Pyroptosis in anti‐bacteria immunity: sensing and execution
Authors: Shao Feng
Published: November 2023

Inflammatory caspases including caspase‐1, 4, 5 and 11 are critical for cytosolic defences against bacterial infections. Caspase‐1 is activated by canonical inflammasomes that sense diverse bacterial such as flagellin or pathogen virulence activity; caspase‐4/5 in human and caspase‐11 in mice are cytosolic receptors for bacterial LPS, determining Gram‐negative bacteria‐induced septic shock. Common to inflammatory caspases activation is pyroptosis, a programmed necrotic cell death. Using genome‐wide CRISPR/Cas9 screens, we identify GSDMD as a pyroptosis substrate for all inflammatory caspases. Inflammatory caspases cleave the gasdermin D (GSDMD) protein to trigger pyroptosis. GSDMD contains a functionally important gasdermin‐N domain that is shared in the gasdermin family. The functional mechanism of action of gasdermin proteins is unknown. We show that the gasdermin‐N domains of the gasdermin proteins GSDMD, GSDMA3 and GSDMA can bind membrane lipids, phosphoinositides and cardiolipin, and exhibit membrane‐disrupting cytotoxicity in mammalian cells and artificially transformed bacteria. Gasdermin‐N moved to the plasma membrane during pyroptosis. Purified gasdermin‐N efficiently lysed phosphoinositide/cardiolipin‐containing liposomes and formed pores on membranes made of artificial or natural phospholipid mixtures. Most gasdermin pores had an inner diameter of 10~14 nm and contained 16 symmetric protomers. The crystal structure of GSDMA3 showed an autoinhibited two‐domain architecture that is conserved in the gasdermin family. Structure‐guided mutagenesis demonstrated that the liposome‐leakage and pore‐forming activities of the gasdermin‐N domain are required for pyroptosis. These findings reveal the mechanism for pyroptosis and provide insights into the roles of the gasdermin family in necrosis, immunity and diseases.
Modeling the gut microbiota with mathematical ecology
Authors: Xavier Joao
Published: November 2023

The symbiotic microbes that make up our gut microbiota protect us against pathogens of the intestinal tract. The microbiota suffers, however, when we take antibiotics to treat infections: antibiotics harm the protective symbionts, increasing the risk of gut infection by antibiotic‐resistant pathogens. We developed mathematical models of microbiota ecology to understand this paradox. We confronted our models' findings with a large longitudinal dataset from more than 1,000 hospitalized Memorial‐Sloan Kettering patients. The models described how the symbionts interact with each other to make a protective microbiota, how antibiotics perturb those interactions and how a perturbed microbiota increases the risk of infection by an antibiotic‐resistant pathogen. The realization that ecology can explain protection against infection has the potential to impact the rational design of antibiotic therapies and of microbiota transplants aimed to reduce the risk, or even treat, antibiotic‐resistant infections.

Support or Funding Information

NIH/NIAID: 1 U01 AI124275 01
Do Child Eating Behaviors Moderate Relationships Between Food Parenting Practices and Child Food Preferences?
Authors: Vollmer Rachel L , Baietto Jamey
Published: November 2023

A majority of existing cross‐sectional studies examine the relationship between food parenting practices and child weight status, but this has been proposed not to be indicative of obesity risk, and therefore, food preferences may provide a better prediction of what a child may consume, and thus, obesity risk. The purpose of this study was to determine the relationship between food parenting practices and child fruit, vegetable, and high fat/sugar food preferences and how child eating behavior moderate those relationships. Parents (n=148) of children (3–7 years old) completed the Comprehensive Feeding Practices Questionnaire (CFPQ), the Preschool Adapted Food Liking Scale (PALS), and the Children's Eating Behavior Questionnaire (CEBQ). Linear regressions were used to test the study purpose with race, ethnicity, and income as covariates. Child control of eating was negatively associated with a child's preference for fruit (B= −8.16, p=.02) and child involvement was positively related to child preference for vegetables (β = .18, p = .04). Child preference for high fat/sugar foods was positively associated with parental use of food to regulate child emotions (B=10.53, p<.01), food as a reward (B=7.21, p < .001), pressure (B=5.07, p = .04), and restriction of unhealthy food (B=5.82, p = .01), and negatively associated with healthy home environment (B=−5.79, p = .05), modeling (B= −7.67, p = .01), and teaching about nutrition (B = −7.51, p = .01). Interaction models revealed that child food responsiveness moderated the relationships between parental pressure (B=7.32, p=.01) and food as reward (B=5.24, p=.02) and child preference for high fat/sugar foods. Specifically, high child food responsiveness exacerbated the relationship between pressure to eat and food as a reward and child preference for high/fat sugar foods. This study provides evidence that the effect of food parenting practices may be dependent upon child eating behaviors.

Support or Funding Information

This project was funding by Illinois State University College of Applied Science and Technology University Research Grant.
What Monitoring Strategies Are Most Successful For Promoting Weight Loss?
Authors: Jospe Michelle R , Roy Melyssa , Brown Rachel C , Williams Sheila M , Osborne Hamish R , Meredith‐Jones Kim A , McArthur Jenny R , Fleming Elizabeth E , Taylor Rachael W
Published: November 2023

Objectives

While tracking progress is one of the strongest predictors of success in healthy eating and physical activity interventions, it is uncertain whether it matters which behavior (diet, activity or weight) is being tracked. The aim of this study was to determine the effectiveness of four different monitoring strategies on weight loss, body composition, blood markers, and psychosocial indices in overweight and obese adults undertaking a 12‐month weight loss program.

Methods

250 overweight or obese adults were randomized to track either a) their weight daily, b) dietary intake using My Fitness Pal, c) hunger (using a novel method called “hunger training”), d) progress via regular face‐to‐face meetings, or a control group for 12 months. All participants received diet and exercise advice and 171 participants completed the study.

Results

All groups lost weight over the course of the intervention (typically 3.9–6.8kg) with no difference between the intervention groups and the control (all p ≥ 0.084). However, participants who tracked hunger lost significantly more weight at 1‐year than those who tracked dietary intake (3.2kg, 0.1–6.4kg, p=0.046), or who met regularly with a support person (2.9kg, 95% CI 0.8–5.1kg, p=0.008). Few significant differences were observed in eating behavior (all p≥0.111), although the face‐to‐face and hunger tracking groups reported more favorable effects on depression and anxiety at 1‐year than control participants. Adherence to the monitoring strategies (% recommended days) ranged from 29.6% for hunger training to 63.6% for attendance at the monthly face‐to‐face sessions.

Conclusions

Daily tracking of weight, food, or hunger, or regular face‐to‐face support did not result in significantly greater weight loss compared with diet and exercise advice alone. However tracking hunger may be a promising approach for encouraging weight loss.

Support or Funding Information

University of Otago Research Grant
Differences Between Organic and Conventionally Produced Milk Reduce When Both Systems Use Pasture‐feeding
Authors: Schwendel Brigitte H. , Wester Timothy J. , Morel Patrick C.H. , Fong Bertram , Tavendale Michael H. , Deadman Craig , Shadbolt Nicola M. , Otter Don E.
Published: November 2023

Milk fatty acid (FA) composition has been the main focus of comparisons between organic and conventionally produced milk. In addition, studies commonly report on differences in FA composition between grazed organic cows and housed, concentrate‐fed conventional cows. Our study investigated two farms sets, consisting of one organic and one conventional farm respectively, with each set managed similarly at the same location. We accounted for known influence factors on milk composition and selected farms that utilized Jersey×Holstein‐Friesian cows being fed > 95% forage. We investigated whether individual farm characteristics or farm system (organic or conventional) had greater influence on milk composition. Milk samples of all four farms where collected throughout the milking season (1–2 per week) and analysed for milk FA, major casein and whey proteins, free oligosaccharides, and milk fat volatiles. We demonstrated that FA composition, especially vaccenic acid, α‐linolenic acid, and conjugated linoleic acid was influenced by the farm system, independent of the farm set, as a consequence of differences in nitrogen fertilizer application. Similar to FA, system effects were observed for half of the observed oligosaccharides, however, these results cannot be explained at present and further research into the influence factors of individual bovine oligosaccharides is needed. Farm set was the dominant influence factor on protein composition, predominantly as a result of differences in pasture composition, while neither system nor farm altered milk fat volatile composition. Our observations show that individual milk compounds are affected differently by farm and system effects, and no comprehensive, universal conclusions can be drawn on differences in chemical composition between organic and conventional milk.

Support or Funding Information

This work was funded by grants from Fonterra Cooperative Group Limited (New Zealand), Ministry of Science and Innovation (New Zealand), and the Agricultural and Marketing Research and Development Trust (AGMARDT; New Zealand)
Nanoparticles encapsulated with resveratrol induce browning of white adipocytes
Authors: Overby Haley , Zu Yujiao , Wang Shu , Zhao Ling
Published: November 2023

Functional brown adipose tissue, including classical brown adipocytes and brown‐like or beige adipocytes, which develop within white adipose tissue (WAT) in response to various stimuli, has emerged as novel targets for obesity treatment and prevention. Through browning process, beige adipocytes are induced to express UCP‐1 and become capable of thermogenesis. Identifying nutritional strategies that increase UCP‐1 and induce browning within white adipocytes is key to unlocking browning potential. Resveratrol (Res) is a well‐known polyphenol found in the skins of grapes and other fruits such as berries with anti‐inflammatory, antioxidant, and anti‐carcinogenic properties. Nanotechnology has shown great promise in encapsulating polyphenols, such as Res, to increase their solubility and stability, consequently, bioactivities. In this study, Res encapsulated in biocompatible and biodegradable lipid nanoparticles (Nano‐Res) or liposomes (Lipo‐Res), along with free Res (Res) and their respective controls (Nano‐Void or Lipo‐Void respectively) were tested at three doses (5, 10, 20 μM) in 3T3‐L1 mouse pre‐adipocytes in a 7‐day differentiation process. At the end of differentiation, the cells were subjected to thermogenic activation by isoproterenol (ISO), a β‐adrenergic receptor agonist, or the control for 6 hours. Cytotoxicity of the treatments and mRNA expression of UCP‐1, brown (PPARγ, PGC1α, PRDM16, and Cidea), beige (CD137 and Tmem26), and white marker genes (IGFBP3), as well as mitochondria related genes (Cox4a, Uqrch, Nrf, and Tfam) were measured. We report that none of the treatments showed signs of cytotoxicity at 24‐hrs and minimal toxicity at 72‐hrs. Lipo‐Res and Nano‐Res significantly induced dose‐dependent increase of UCP‐1 mRNA expression under ISO stimulated conditions compared to the controls (p<0.05). At the low dose of 5 μM Lipo‐Res significantly stimulated UCP‐1 to a higher level than free Res (p<0.05). Under both basal (non‐ISO stimulated) and ISO stimulated conditions, both Lipo‐Res and Nano‐Res dose‐dependently decreased WAT marker IGFBP3 mRNA (p<0.05) while simultaneously increasing mRNA of beige marker CD137 and brown markers PRDM16 (p<0.05). Interestingly, Lipo‐Res significantly increased Cidea expression in ISO‐stimulated conditions (p<0.05); however, Nano‐Res (and Nano‐Void) decreased Cidea expression (p<0.05). Other beige markers and mitochondrial structural genes were increased by encapsulated Res, but did not reach significance compared to the controls. Taken together, our results demonstrate that nanoencapsulation enhances Res's bioactivities in inducing browning of white adipocytes. Our results point towards promising nutritional strategies for obesity treatment and prevention.

Support or Funding Information

The work has been supported by NIH 1R15AT008733 award.
Anthocyanin profiles and contents in processed raspberries on the US market
Authors: Wu Xianli , Sun Jianghao , Ahuja Jaspreet , Haytowitz David B , Burton‐Freeman Britt , Chen Pei , Pehrsson Pamela R
Published: November 2023

Raspberries rank as the third most popular berry in the United States. Consumption of raspberries has steadily increased over the last decade in the US. Growing awareness of their nutrient density and potential health benefits of bioactive compounds including anthocyanins (ACNs) has aided this pattern. Processed raspberries are frequently used in commercial applications due to their ease of use, longer shelf‐life and peak ripeness. However, there is only limited data on ACNs in processed raspberries. In this study, ACN profiles and contents in common processed forms of raspberries (frozen, juice concentrate and puree (seeded and seedless)) on the US market were investigated. Thirty‐four nationally representative samples, including domestic and imported, were purchased either at supermarkets according to the USDA National Food and Nutrient Analysis Program (NFNAP) sampling plan or by arrangement with individual raspberry processors. The ACN analyses were performed in a HPLC‐MS system. In total, seven cyanidin or pelargonidin glycoside were identified and quantified, though different samples contained 4 to 5 of them. Cyanidin‐3‐O‐sophoroside and cyanidin‐3‐O‐glucoside were the primary ACNs detected in all samples. The ACN profiles and contents varied within the same type of processed samples and between the different processed types of raspberries. Five ACN profiles were observed in 18 frozen raspberry samples, and their total ACN contents ranged from 14.38 ± 0.81 to 38.43 ± 2.75 mg fresh weight (FW)/100 g. Four raspberry juice concentrates were found to contain the same ACNs, and the total ACN contents ranged from 30.96 ± 5.34 to 62.29 ± 3.37 mg FW/100 g. Four ACN profiles were observed in 12 raspberry puree samples and their total ACN contents ranged from 10.89 ± 0.94 to 27.11 ± 1.15 mg FW/100 g. In conclusion, seven individual ACNs of either cyanidin or pelargonidin parent structures were identified in nationally representative processed raspberry samples. The ACN profiles varied slightly but contents varied considerably among these samples, which may reflect differences in varieties, origins, processing methods and or other influential factors.

Support or Funding Information

Supported by National Processed Raspberry Council
Factors Shaping Breastfeeding Support Benefits in Workplaces: Perspectives of Human Resources Managers
Authors: Uribe Alexandra Luisa MacMillan , Bolton Tracie Ann , Woelky Kaitland , Olson Beth H
Published: November 2023

Breastfeeding (BF) has significant health benefits over formula for the mother and infant. Health professionals recommend mothers breastfeed exclusively for the first 6 months of life and continue, with complementary foods, to at least 1 year. Working women do not breastfeed as long as those not employed, and yet 58% of women with a child <1 year are in the labor force. In 2010, as part of the Affordable Care Act, federal legislation mandated employers provide a non‐restroom space and unpaid time for BF employees to pump. The US Department of Health and Human Services “Business Case for Breastfeeding” program outlines additional supports, achievable with minimal investment, helpful to BF employees. Few companies provide additional supports, which may contribute significantly to lack of BF success and public health improvements. Gaining an understanding of how Human Resources Managers (HRMs) determine which benefits to provi‐‐de is crucial for gaining inclusion of more comprehensive supports. The purpose of this study was to compare and contrast factors that shape decisions regarding overall employee benefits versus BF support. Fifteen semi‐structured, in‐depth interviews were conducted with HRMs from Michigan companies, who had previously responded to a BF support survey. A‐priori codes based on a theoretical model informed by organizational behavior theories was used, followed by grounded codes from emergent themes. The major themes included: (1) HRMs' primary concern was meeting the needs of their employees, regardless of type of benefit. (2) Offering general benefits standard for the majority of employees (e.g. health insurance) was viewed as essential to recruitment and retention, whereas BF benefits were viewed as discretionary benefits. (3) The federal mandate brought awareness to BF in the workplace; however, providing additional BF supports versus only the mandated supports was strongly influenced by HRMs' perception of employee need. These results indicate a discrepancy in the perceived value of BF supports between companies that provide benefits and health professionals; companies view it as a family‐friendly accommodation whereas health professionals see it as a health benefit. Communications to HRMs should include information on the unrecognized need for BF support, the variety of supports available with a relatively small investment, and the health benefits. However, communications may be more effective if also framed within the HRMs' context, e.g. as a benefit helpful to positioning a company as family‐friendly, which companies express as important to the recruitment and retention of employees.
Synergistic Effects of Platelet Activating Factor and TNF‐α in Promoting Intestinal Epithelial Migration and Mucosal Wound Repair
Authors: Siuda Dorothée , Quirós Miguel , O'Leary Monique , Brazil Jennifer , Hinrichs Benjamin , Neish Andrew , Parkos Charles , Nusrat Asma
Published: November 2023

The epithelial barrier plays a pivotal role in controlling mucosal homeostasis. In response to injury, epithelial cells migrate and proliferate to cover denuded mucosal surfaces. Inflammatory mediators released at sites of mucosal injury by infiltrating immune cells and the epithelium have been proposed to influence wound repair mechanisms. We observed upregulation of pro‐inflammatory mediators Platelet Activating Factor (PAF) and Tumor Necrosis Factor alpha (TNF‐α) in healing colonic mucosal wounds. PAF signaling in epithelial cells is mediated by a G‐protein coupled receptor, platelet activating factor receptor (PAFR). In vitro studies demonstrated that PAFR signaling in response to PAF promotes intestinal epithelial cell migration and wound repair by the generation of reactive oxygen species and phosphorylation of focal adhesion kinase (FAK) at sites of cell‐matrix contacts. Epithelial pro‐repair properties of PAF were markedly augmented by exposure to TNF‐α and IFN‐γ and mechanistically linked to cytokine‐enhanced expression of epithelial PAFR. Complementary in vivo analyses of biopsy induced colonic mucosal wound closure revealed delayed mucosal wound healing in PAFR−/− mice compared to wildtype mice. These results support a pro‐repair effect of PAFR signaling in intestinal mucosal wounds that is potentiated by inflammatory cytokine TNF‐α and IFN‐γ signaling. Our findings delineate a novel cross‐talk between PAFR and pro‐inflammatory cytokines at sites of mucosal wounds that serves to coordinate epithelial repair and restore the mucosal barrier integrity.

Support or Funding Information

R01‐DK089763‐05A1: Formyl peptide receptors as mediators of intestinal mucosal homeostasis, National Institutes of Health; SI2282/1‐1, German Research Foundation
Histone demethylase KDM5B is critical for PI3K‐AKT‐mTOR signaling and stemness of melanoma
Authors: Yan Qin , Zhang Shang‐Min , Meeth Katrina , Micevic Goran , Bosenberg Marcus
Published: November 2023

Epigenetic states are critical for the maintenance of cancer stem cells, which drive tumor initiation, relapse, and metastasis. Recent studies have suggested histone demethylase KDM5B is crucial for the plasticity of melanoma stem‐cell like subpopulations. Utilizing a series of human‐relevant mouse melanoma models, we previously identified two types of mouse melanoma propagating cells (MPCs). Based on these findings, we hypothesized that KDM5B is critical for the maintenance of MPCs. Indeed, we found that knockdown of KDM5B decreased MPC populations. Consistent with these results, knockdown of KDM5B decreased clonogenicity of these mouse melanoma cells. These phenotypes were linked to decreased PI3K‐AKT‐mTOR signaling. These results strongly suggest that KDM5B regulates melanoma formation and progression, and its inhibition could be combined with immune checkpoint blockade to treat melanoma.

Support or Funding Information

Department of Defense Peer Reviewed Cancer Research Program Award W81XWH‐13‐1‐0235 and W81XWH‐16‐1‐030, Melanoma Research Foundation Career Development Award, Yale Comprehensive Cancer Center pilot grant, and Yale SPORE in Skin Cancer Developmental Research Award
The Influence of ENPP1 Expression in Mucosal Tissues
Authors: Curtis Valerie , Wang Ruth , Battista Kayla , Lee J. Scott , Colgan Sean
Published: November 2023

Previous work has established that extracellular adenosine signaling is protective in mucosal inflammation and promotes the resolution of ongoing inflammation. The sources of extracellular adenosine include enzymatic processing from nucleotides, such as ATP and AMP, which can be liberated from a variety of cell types, including leukocytes. Guided by a microarray screen of hypoxia‐inducible genes in mucosal epithelial cells, we identified the strong induction of ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) in a time‐dependent manner. ENPP1 is a type II transmembrane glycoprotein that can hydrolyze ATP and diadenosine triphosphate (Ap3A) to AMP and inorganic pyrophosphate. ENPP1, present on the surface of chondrocytes, has been extensively studied for its role in tissue mineralization. Its potential role in the resolution of mucosal inflammation via AMP generation has yet to be determined. Presently, we have established that ENPP1 mRNA is expressed in T84 and Caco‐2 intestinal epithelial cells, and this expression can be upregulated by conditions that drive epithelial metabolism (e.g., exposure to the short chain fatty acid butyrate). Likewise, studies in mouse intestinal epithelial cells lacking the transcription factor HIF‐1a revealed significantly diminished expression of ENPP1. In parallel, it was revealed that activated human neutrophils are a source of Ap3A, previously thought to be made primarily by platelets. These studies indicate that Ap3A and ENPP1 at the mucosal surface may function to provide an additional source of adenosine, sub‐serving its role in inflammatory resolution.

Support or Funding Information

This work was supported by NIH grants DK50189, HL60569 and DK95491 and by grants from the Crohn's and Colitis Foundation of America.
Autophagy regulates hepatocellular senescence
Authors: Huda Nazmul , Khambu Bilon , Chen Xiaoyun , Yin Xiao‐Ming
Published: November 2023

Autophagy and senescence are two distinct but functionally intertwined stress mediated cellular process. In advanced human liver disease there is widespread senescence in hepatocytes. Several lines of evidence showed that the hepatocyte senescence was associated closely with fibrosis stage and an adverse outcome in chronic liver disease. Mechanism that establishes the relationship between autophagy and senescence in liver is unclear. In this study we have used mice whose hepatocytes lack Atg7 (and thus autophagy) to elucidate the precise trigger that induce senescence and the pathway leading to senescence mechanism. Here we report evidence that autophagy deficient hepatocytes showed higher expression of senescence associated factors including p15, p21, CDKN3, & HP1γ compared to wildtype. Autophagy defects activated the oxidative stress and DNA damage responses in hepatocytes. Moreover, the autophagy deficiency caused significantly increase in β‐galactosidase activity, and SASP phenotype in hepatocytes.

Conclusion

Dysregulation of autophagy causes senescence in hepatocytes, which can contribute to the pathology of the autophagy‐deficient liver.

Support or Funding Information

NIH, R21AA 021450 and R01AA021751; Department of Pathology and Laboratory Medicine Indiana University School of Medicine Indianapolis, IN 46202
RNA Granule Organization
Authors: Lehmann Ruth , Trcek Tatjana , Grosch Markus , Shroff Hari , Lionnet Timothée
Published: November 2023

Germ granules, specialized ribonucleoprotein particles, are a hallmark of all germ cells. In Drosophila, an estimated 200 mRNAs are enriched in the germ plasm, and some of these have important, often conserved roles in germ cell formation, specification, survival and migration. How mRNAs are spatially distributed within a germ granule and whether their position defines functional properties is unclear. We have used single‐molecule FISH and structured illumination microscopy, a super resolution approach, to show that mRNAs are spatially organized within the granule whereas core germ plasm proteins, such as Vasa, Oskar, Tudor and Aubergine are distributed evenly throughout the granule. Multiple copies of single mRNAs self‐organize into “homotypic clusters” that occupy defined positions within the granule. This organization, which is maintained during embryogenesis and independent of the translational or degradation activity of mRNAs, reveals new regulatory mechanisms for germ plasm mRNA‐protein that may be applicable to other mRNA granules.

Support or Funding Information

Howard Hughes Medical Institute and NICHD
New insights into intravascular lipolysis and new causes of hypertriglyceridemia
Authors: Young Stephen G. , Beigneux Anne , Fong Loren , Ploug Michael
Published: November 2023

GPIHBP1, a GPI‐anchored protein of capillary endothelial cells, is crucial for the lipolytic processing of triglyceride‐rich lipoproteins (TRLs). GPIHBP1 binds lipoprotein lipase (LPL) in the interstitial spaces and shuttles the enzyme to its site of action in the capillary lumen. GPIHBP1 is also required for the margination of TRLs along capillaries—so that lipolytic processing can proceed. Finally, the binding of LPL to GPIHBP1 reduces the spontaneous unfolding of LPL's catalytic domain, thereby stabilizing LPL catalytic activity. GPIHBP1 mutations cause severe hypertriglyceridemia; the majority are missense mutations that interfere with the proper conformation of GPIHBP1's LU (Ly6‐uPAR) domain and thereby abolish the capacity of GPIHBP1 to bind and transport LPL. Recent studies have shown that GPIHBP1 is also highly to the pathogenesis of acquired forms of hypertriglyceridemia.

Support or Funding Information

Leducq Foundation; National Heart, Lung, and Blood Institute
Geranylgeranyl‐Regulated, ER‐to‐Golgi Transport of UBIAD1: Implications for Cholesterol Homeostasis and Schnyder Corneal Dystrophy
Authors: DeBose‐Boyd Russell A.
Published: November 2023

Multiple feedback mechanisms converge on the ER (endoplasmic reticulum)‐localized enzyme HMG CoA reductase, which catalyzes a key step in synthesis of cholesterol and essential nonsterol isoprenoids including Fpp (farnesyl pyrophosphate) and GGpp (geranylgeranyl pyrophosphate), which can become attached to many proteins and are utilized in synthesis of dolichol, ubiquinone, heme, and vitamin K2. One mechanism for feedback control of reductase involves sterol‐induced ubiquitination, which marks the enzyme for ERAD (ER‐associated degradation) that is augmented by GGpp, but not by Fpp. Here, we show that sterols trigger binding of a subset of reductase molecules to UBIAD1 (UbiA prenyltransferase domain‐containing protein‐1), a prenyltransferase that utilizes GGpp to synthesize the vitamin K2 menaquinone‐4. Sterol‐induced binding to UBIAD1 protects reductase from accelerated degradation, permitting continued synthesis of nonsterol isoprenoids in sterol‐replete cells. GGpp triggers release of UBIAD1 from reductase, allowing for maximal ERAD of reductase.

Mutations in UBIAD1 cause SCD (Schnyder corneal dystrophy), an autosomal dominant eye disease in humans characterized by corneal accumulation of cholesterol. SCD‐associated mutants of UBIAD1 resist GGpp‐induced displacement from reductase and thereby inhibit its sterol‐accelerated ERAD. In the course of our studies, we discovered that GGpp also stimulates translocation of UBIAD1 from the ER to Golgi. SCD‐associated mutants of UBIAD1 are refractory to GGpp‐induced translocation to the Golgi and remain sequestered in ER membranes where they inhibit reductase ERAD in a dominant‐negative fashion. These results support a model that posits upon sensing GGpp depletion in membranes of the ER, UBIAD1 becomes trapped in the organelle and inhibits reductase ERAD so as to stimulate mevalonate synthesis for replenishment of GGpp. This novel sensing mechanism directly controls ERAD of reductase and becomes disrupted in SCD, which likely contributes to the accumulation of cholesterol that characterizes the eye disease.

Support or Funding Information

This work is supported by NIH grants HL20948, GM112409, and GM119180.
Bromodomain and Extraterminal (BET) Proteins Regulate Hepatocyte Proliferation in Hepatocyte‐Driven Liver Regeneration
Authors: Russell Jacquelyn Olivia , Ko Sungjin , Shin Donghun , Monga Satdarshan Paul
Published: November 2023

Bromodomain and extraterminal (BET) proteins are epigenetic readers capable of binding to the acetylated lysine tails of histones, where they recruit key components of the basic transcriptional machinery to promote transcriptional activation of a wide variety of genes. Aberrant epigenetic gene regulation has been identified in many human malignancies, including genetic mutations in BET proteins. Excitingly, small molecule inhibitors of BET proteins, such as JQ1, have shown efficacy in preclinical models of various hematological and solid tumors without widespread toxicity to normal tissues. Importantly, JQ1 was shown to inhibit cell growth of hepatocellular carcinoma (HCC) cell lines. BET proteins have also been shown to regulate cell proliferation in non‐tumor settings. We recently showed BET proteins regulate biliary‐driven liver regeneration. Therefore, we sought to study the roles of BET proteins in other models of liver regeneration. Since two‐thirds partial hepatectomy (PHx) in rodents and acetaminophen (APAP)‐induced liver injury in both zebrafish and mice are well‐established models to study the mechanisms of hepatocyte proliferation, we set out to determine if JQ1 could inhibit liver regeneration by blocking hepatocyte proliferation in the PHx and APAP‐injury models. We injected mice with JQ1 either 2 or 16 hours post‐PHx in order to determine the kinetics of BET protein activation and harvested animals at approximately 45 hours post‐surgery, as hepatocyte proliferation in mice peaks around 36–48 hours post‐PHx. We demonstrate here that animals treated with JQ1 after PHx display notably increased liver injury with elevated transaminases and a near‐complete inhibition of hepatocyte proliferation. Treatment with JQ1 after sham surgery did not induce liver injury in mice. Levels of Cyclin D1 mRNA and protein were reduced in 16 hour post‐PHx JQ1 injected animals, and were even further reduced if JQ1 was injected 2 hours post‐PHx. Zebrafish larvae treated with JQ1 after APAP‐induced liver injury also displayed impaired hepatocyte proliferation. Therefore our results show that BET proteins regulate hepatocyte proliferation‐driven liver regeneration and establish a model to determine the mechanisms by which BET proteins promote hepatocyte proliferation.

Support or Funding Information

Funding was provided via the NIH CATER training grant T32 EB001026. Funding was additionally provided through the NIDDK via 5R01DK062277‐13. Support was provided by the Cellular & Molecular Pathology Graduate Program at the University of Pittsburgh.
Dramatization of Starling Forces: An Interactive Learning Approach
Authors: Connor Brian W , Carvalho Helena
Published: November 2023

Purpose

VTCSOM is a modern hybrid medical school where student learning is facilitated outside of the traditional classroom setting through active learning approaches such as Problem‐Based Learning, hands‐on workshops and lectures. When students are actively engaged during the teaching/learning process, they understand topics in a more comprehensive fashion. As the amount of information which medical students are expected to master grows, it becomes necessary to develop and implement innovative learning methodologies that help students to retain and apply complex physiological topics, rather than rote memorization. Our goal is to use dramatization to interactively teach the effects of Starling forces in the microcirculation.

Methods

A brief introduction was given on the topic of Starling forces regulating microcirculation for 23 first year medial students. One half of the group moved to an area representing the lumen of the capillary while the other half moved to an area representing the interstitium. Four to seven other students represented dynamic fluid molecules. They competed to move faster than their peers from circulation (capillary) to the interstitium or vice versa under the influence of hydrostatic and coloidosmotic pressures or a clinical vignette, as they were projected. The task for the students, behaving as fluid, was to move into or out of the space designated as capillary.

Results

In an anonymous survey, 23 students were evaluated on their knowledge of Starling forces and edema both before and after this kinetic learning approach. The pre and post‐activity surveys, which were evaluated on a 100‐point grading scale, contained the same questions randomized in a different order. An overall improvement was seen from the pre‐activity performance (χ̄ =45.4±sd=25.1; range 9–91%) to the post‐activity performance (χ̄ =77.5±sd=14.1, range 45–100%). Additionally, in a subjective question included in the post‐survey 85% of students found this activity to be an effective way of learning.

Conclusion

Integrating interactive approaches into teaching in the context of undergraduate medical education can be helpful in demonstrating challenging yet important concepts, such as fluid exchange in the microcirculation. After the activity, students showed a 32% improvement in their understanding of Starling forces and edema with a substantial decrease in variation between students. Thus, our data coincide with literature that shows active learning approaches can be effective in replacing or complementing passive learning in traditional lectures.
A Summer PhUn Week for English Language Learners
Authors: Halpin Patricia A. , Pugh R. Michael
Published: November 2023

Our ongoing hypothesis has been that PhUn Week activities can help students learn about science and build English Language skills at the same time. In the summer of 2016, twenty‐nine students in grades 7–12 who are English Language Learners took part in PhUn Week, an annual international physiology program that engages K‐12 students in physiology activities and introduces them to science careers. The participating students were enrolled in the EXCELL‐in‐STEM program (Educational Excellence for English Language Learners in Science, Technology, Engineering, and Mathematics) at the University of New Hampshire, Manchester. This was the fourth summer in which the EXCELL‐in‐STEM students took part in this project. During PhUn Week, students perform an exercise physiology experiment, led by a physiologist, in which they learn about the heart and about the scientific method. As a group these young English Language Learners create their hypothesis: exercise increases heart rate and blood pressure. To test this hypothesis, they use monitoring equipment to measure their pre‐exercise heart rate and blood pressure; then they run a prescribed distance and take post‐exercise measurements. Selected students report their results to the group. After discussion, students each year have consistently agreed that their results support their hypothesis. In addition to exploring physiology as a subject and a career through this PhUn week activity, students learn science vocabulary and the appropriate English Language structures for stating a hypothesis, asking relevant questions, and reporting their results. This foundation in the scientific method in the first week of the five‐week program prepares the students for upcoming STEM/English projects and for participation in STEM courses in their schools.
A Comparison of Student Profiles and Performance in an Introductory Non‐Majors Biology Course Offered 100% in the Classroom vs. 100% Online
Authors: Daggett Melissa A. F.
Published: November 2023

Academic institutions are under increasing pressure to provide students with online alternatives to the traditional 100% classroom format. One concern for biology faculty is whether online courses can provide students with an education comparable to one offered in the more traditional format. In this presentation, I will present the methods used to deliver an introductory non‐majors biology course that was offered simultaneously in a traditional 100% classroom format with one offered 100% online. Both formats included the same reading and homework assignments, identical postings of faculty presented lectures and similar, though not identical laboratory activities. Analysis of the student profiles along with a comparison the outcomes and performance upon completion of the courses will be presented. This presentation will not address all the concerns faculty may have in moving away from a traditional course format, but may provide information to suggest that online students are able to acquire a comparable education as students taking courses in the traditional format.