bluuebunny/crossref_metadata_2025 huggingface dataset:
Postnatal changes in low birth weight piglets fed a high‐energy diet
Authors: McCauley Sydney R , Chen Ying , Oliver Katherine R , Rhoads Robert P , El‐Kadi Samer
Published: November 2023

Postnatal growth is reduced in low (LBWT) compared with normal (NBWT) birth weight piglets. Our data suggest that weight gain and fat and protein deposition are lower in LBWT compared with NBWT piglets, despite feeding equivalent amounts of the same diet. The objective of this study was to investigate growth performance, body composition, and glucose clearance in LBWT and NBWT piglets when dietary energy supplies were increased. Day old piglets (n=6) were fed either low (LE) or high‐energy (HE), isonitrogenous diets containing 80% or 100% of metabolizable energy requirements. Body composition was determined using dual energy x‐ray absorptiometry before and 11 days after initiation of feeding. Fasting intravenous glucose tolerance test (IVGTT) was administered on days 1 and 13 of the study. At termination of the experiment muscles and visceral organs were weighed. Increasing dietary energy did not significantly increase growth rate of LBWT or NBWT pigs, however LBWT pigs were consistently lower than those in the NBWT group (P<0.05). Final fat and lean mass increased in both NBWT and LBWT piglets regardless of diet (P<0.05). Liver and longissimus dorsi weights as a percentage of whole body weight were higher in piglets fed a HE compared to those fed LE diet (P <0.05). There were no differences in glucose clearance across all groups. In conclusion, increasing dietary energy does not promote growth of LBWT or NBWT piglets, in large due to an increase in digestive organ weight.
Systematic review of anthocyanins and markers of cardiovascular disease
Authors: Wallace Taylor C , Slavin Margaret , Frankenfeld Cara L
Published: November 2023

Anthocyanins are dietary flavonoids commonly consumed in the diet. Evidence from epidemiological studies suggests cardiovascular disease (CVD) preventative and therapeutic effects of anthocyanins. We systematically reviewed randomized controlled trials (RCT) testing the effects of purified anthocyanins and anthocyanin‐rich extracts on the following markers of CVD: triglycerides, total cholesterol, LDL cholesterol, HDL cholesterol, and blood pressure in both healthy and diseased populations. Eligible studies included RCT of the adult population published in English. We searched PubMed, Web of Science Core Collection, and BIOSIS Previews for relevant articles from inception until July 1, 2014. Twelve RCT representing 10 studies were included in the review. Trials ranged in size (31–152 individuals enrolled), duration (3–24 wk), and anthocyanin dose (7–640 mg/d). Supplementation with anthocyanins did not affect CVD biomarkers among healthy individuals. Triglycerides, total cholesterol, HDL cholesterol, and blood pressure were not changed among diseased individuals after anthocyanin treatment. Anthocyanin treatment did consistently decrease LDL cholesterol in diseased individuals and/or those with elevated biomarkers of CVD. No adverse effects were reported across studies at levels up to 640 mg/d. Major limitations of trials included in the qualitative analyses include short trial durations and large variability in the dose administered within the trials, among others. LDL cholesterol is an established biomarker of CVD risk, and these trials suggest that anthocyanin supplementation may decrease LDL cholesterol among individuals with elevated biomarkers, with little to no safety concerns. Longer‐duration trials assessing dose response are needed to adequately determine whether an effect of supplementation exists.

Support or Funding Information

No funding was accepted for this abstract and manuscript.
Effect of 3 Probiotic Strains on Bile Acids and Glucose Metabolism in Healthy Adults: a Randomized, Double‐Blind Placebo‐Controlled Crossover Study
Authors: Culpepper Tyler , Rowe Cassie C , Nieves Carmelo , Girard Stéphanie‐Anne , Christman Mary , Chung Soonkyu , Thompkins Thomas A , Langkamp‐Henken Bobbi
Published: November 2023

Background

Probiotics have been shown to transiently modify the intestinal microbiota by favoring the growth of endogenous bacteria possessing bile salt hydrolase (BSH) activity. The BSH activity promotes deconjugation and excretion of bile acids and shifts metabolism from cholesterol synthesis to bile formation, thereby attenuating systemic cholesterol levels and decreasing risk of cardiovascular diseases.

Objective

The aim of this study was to determine the effect of 3 different probiotic strains on bile acid and glucose metabolism.

Methods

In a randomized, double‐blind crossover study, healthy middle‐aged adults (52.6 ± 7.7 years old) with a larger waist circumference (>102 cm and >88 cm for males and females, respectively) received 1 capsule/day of Bacillus subtilis R0179 (2.5 × 109 CFU/capsule) (n=39), Lactobacillus plantarum HA 119 (5 × 109 CFU/capsule) (n=38), Bifidobacterium animalis subsp. lactis B94 (5 × 109 CFU/capsule) (n=37) or placebo for 6 wks. Following a 4‐wk washout period, participants were crossed to the other treatment (i.e. probiotic to placebo or placebo to probiotic). Stool frequency and consistency were recorded on a daily basis. Blood and stool samples were collected at the beginning and end of each intervention to measure bile acids. Serum lipids and markers of glucose metabolism were measured in the blood. Weekly measures included gastrointestinal symptoms (Gastrointestinal Symptom Rating Scale (GSRS)) and physical activity levels (Internal Physical Activity Questionnaire (IPAQ)).

Results

The change in deconjugated plasma bile acids was greater with consumption of B. subtilis R0179 (691±378nmol/L, p=0.01) and B. animalis subsp. lactis B94 (380±165nmol/L, p=0.04) than with combined placebo data (98±176nmol/L). This change was only observed in obese participants (Body Mass Index ≥ 30). Additionally, there was a trend towards an increase in HDL plasma levels during the L. plantarum HA 119 intervention (3.0±1.3mg/dL, p=0.0774) versus the placebo (−0.3±0.8mg/dL). No significant differences were observed for any probiotics for stool bile acids, other serum lipids, gastrointestinal symptoms and function, blood glucose and insulin, and physical activity levels.

Conclusions

These data suggest that B. subtilis R0179 and B. animalis subsp. lactis B94 had no effect on glucose metabolism or serum cholesterol but significantly increased deconjugated plasma bile acids. It is possible that de novo bile acid synthesis was inhibited by these probiotics through the Farnesoid X Receptor (FXR) in the ileum. Additional clinical studies should be conducted to confirm these findings and explore the mechanism by which probiotics may simultaneously modulate cholesterol absorption and catabolism to bile acid.

Support or Funding Information

Lallemand Health Solutions
Plasma Trans Palmitoleic Acid and Cardiometabolic Risk factors in Youth with Type 1 Diabetes: SEARCH Nutrition Ancillary Study
Authors: The Natalie S. , King Irena B. , Crandell Jamie L. , Couch Sarah , Tzeel Benjamin , Liese Angela D. , Dabelea Dana , Mayer‐Davis Elizabeth
Published: November 2023

The identification of modifiable risk factors associated with cardiometabolic traits is critical for improving health outcomes in persons with type 1 diabetes (T1D). The adverse effects of trans fatty acids from industrial hydrogenation of oils on health outcomes are well‐documented, but less is known about the health effects of trans fatty acids produced from biohydrogenation by bacteria in ruminant gut, such as trans palmitoleic acid (TPA; 16:1n‐7t). We examined the association between plasma TPA and cardiometabolic outcomes using data from the SEARCH for Diabetes in Youth Study, an ongoing multi‐center observational cohort study of youth with diabetes diagnosed at < 20 years of age. Participants included those with physician‐diagnosed T1D and positive diabetes autoantibody (glutamic acid decarboxylase‐65 or insulinoma‐associated‐2 autoantibodies) at enrollment (n=826; diabetes duration mean=10.0 mo). Cross‐sectional, linear regression models adjusted for confounders (gender, age, diabetes duration, human leukocyte antigen risk, insulin regimen, insulin dose, race and ethnicity, study site, and maximum parental education) identified a positive association of plasma TPA with low‐density lipoprotein cholesterol (β=2.1; p=0.02), total cholesterol (β=3.1; p=0.003), and diastolic blood pressure (β=0.9; p=0.003), as well as a positive association with high‐density lipoprotein (HDL) cholesterol (β=0.8; p=0.002). No association was observed between TPA with HbA1C, insulin sensitivity, triglycerides, body mass index z‐score, systolic blood pressure, and waist circumference. An adjusted repeated measures model using a smaller sample of participants who had data at baseline and at a follow‐up visit (either 12‐ or 24‐months after baseline visit; n=379) yielded identical results. Findings suggest a differential and complex relationship of TPA on various cardiometabolic traits in youth with T1D. Additional research is needed to determine long‐term effects of plasma TPA on cardiometabolic health in youth with T1D and identify the mechanisms by which TPA may impact these traits.

Support or Funding Information

2R01DK077949‐05
High‐Fat Diet‐Induced Obesity Suppresses Adaptive Thermogenesis via Toll‐Like Receptor (TLR) 4‐Mediated Endoplasmic Reticulum Stress
Authors: Okla Meshail , Wang Wei , Chung Soonkyu
Published: November 2023

Adaptive thermogenesis is a cellular process that dissipates energy as heat, thus defending against obesity, in response to various activators such as cold. Obese subjects are less responsive to thermogenic signaling cues compared to lean subjects. Elevated levels of metabolic endotoxemia and circulating free fatty acids associated with obesity induce innate immune system and TLR4 activation, leading to the development of metabolic disorders. However, whether TLR4 activation plays a role in the adaptive thermogenesis impairment observed in obesity has not been investigated. In this study, we hypothesized that TLR4 activation in a high‐fat (HF) diet‐induced obesity model impairs adaptive thermogenesis. To test this hypothesis, C57BL/6 mice were fed either a low‐fat (LF) or HF diet for 12 weeks, followed by cold acclimation. HF diet‐mediated TLR4 activation concurred with a significant decrease in adaptive thermogenesis, brown‐specific markers, and mitochondrial‐specific markers in subcutaneous white adipose tissue (WAT). To verify the role of TLR4 in WAT browning, chronic low‐dose LPS was administrated to wild type and TLR4 knockout mice. LPS‐injected wild type mice were immune to both cold‐induced WAT browning and β3‐adrenergic receptor agonist (CL‐316,243)‐induced WAT browning, whereas TLR4 knockout mice were able to arouse thermogenesis. Chronic TLR4 activation in our mice resulted in ROS production and ER stress elevation. To understand the molecular link between TLR4 and ER stress in thermogenesis attenuation, ER stress was inactivated by either genetic deletion of CHOP or intraperitoneal injection of a chemical chaperone (PBA). Blunting ER stress protected the mice from TLR4‐induced mitochondrial degradation and rescued WAT browning. Taken together, our results indicate that TLR4 is a pivotal player in thermogenesis impairment observed in obesity. It mediates ROS production and ER stress activation, leading to mitochondrial degradation and WAT browning inhibition. In this study, we identified a novel TLR4/ER stress signaling axis associated with antagonizing WAT browning. Targeting this TLR4/ER stress axis might be efficacious in preventing defective thermogenesis observed in obesity.

Support or Funding Information

NIH 1P20GM104320
High Phosphorus Diet Mitigates Impairments in Lipid and Glucose Metabolism Associated with Diet‐Induced Obesity in Male Sprague Dawley Rats
Authors: Bassil Maya , Zeeni Nadine , Farran Natalie , Obeid Omar
Published: November 2023

Phosphorus (P) nutrition status was found to be inversely related to obesity and metabolic syndrome in observational studies and this is thought to be mediated through an effect of P on liver metabolism (Obeid, 2013). This study thus aims at investigating whether P diet supplementation prevents the metabolic abnormalities associated with diet induced obesity in a controlled animal study. Thirty Sprague‐Dawley adult male rats (mean weight = 201±3g) were allocated into 3 equal groups receiving either a balanced diet (control), high fat diet with regular P concentration of 0.3% (HF) or high fat, high P (0.9%) diet (HFHP). Study lasted for 12 weeks, during which body weight and food intake were measured biweekly and intraperitoneal glucose tolerance test (IPGTT) was performed at the beginning (week2) and end (week 11) of the study. Rats were then sacrificed after 10‐hour fast, abdominal fat and liver were collected and weighed and serum samples were isolated from venous blood drawn from the inferior vena cava. Serum insulin, cholesterol, triglycerides as well as liver enzymes (ALP and ALT) were measured. High fat diet resulted in a significantly higher body weight gain, food intake and liver weight compared with control, irrespective of P supplementation. HF group had higher abdominal fat (0.44±0.12g) compared to control (0.21±0.06g) but this was not observed in HFHP group (0.29±0.10g). IPGTT results at week11 showed similar baseline glucose among groups but significantly (p=0.05) higher glucose at 2 hours post glucose injection in HF group (127±4.2mg/dl) vs. control (113±5.2 mg/dl) indicating glucose intolerance. P supplementation normalized glycemia at 2 hours in HFHP group (113±5.4 mg/dl). Fasting insulin increased significantly (p=0.008) in HF (2.8±0.4ng/ml) vs. control (1.2±0.4ng/ml) but was not different in HFHP group (2.2±0.5ng/ml). High fat induced obesity significantly (p<0.05) increased serum cholesterol, triglycerides and ALP in HF group (46.1±3.9mg/dl, 38.8±4.4mg/dl and 192.8±55.9U/l, respectively) compared to control (19.8±2.7mg/dl, 26.0.1±3.7mg/dl and 76.6±7.3U/l, respectively) but P supplementation in HFHP prevented this increase. In conclusion, high P diet appears to protect against lipid and glucose abnormalities and liver toxicity associated with diet induced obesity in rats. We suggest that P increases hepatic ATP, which drives the shift from lipid synthesis to glycogen and protein synthesis. Further analysis on the liver tissues will help in identifying the exact mechanisms.

Support or Funding Information

The study was funded by the Lebanese American University
Incorporation of Almonds in a Cholesterol‐lowering Diet Improves non‐ABCA1‐mediated Cholesterol Efflux in Normal Weight Adults
Authors: Berryman Claire E. , Fleming Jennifer A. , Kris‐Etherton Penny M.
Published: November 2023

We previously showed that a cholesterol‐lowering diet with almonds, substituted for an isocaloric high‐CHO snack, maintains greater HDL‐C concentrations. However, recent evidence suggests that the cardioprotective effects of HDL may be more dependent on function than absolute HDL‐C levels. Therefore, a randomized, 2‐period (6 wk/period), crossover, controlled‐feeding study was designed to investigate the effects of 1.5 oz./d almonds vs. a calorie‐matched, high CHO snack, within the context of a cholesterol‐loweringdiet, on measures of global and transporter‐specific [ATP‐binding cassette (ABC)sub‐family A1 and non‐ABCA1 (global minus ABCA1 transporter)] cholesterol efflux. Differences in nutrient profiles of the control (CON: 58% CHO, 15%PRO, 26% FAT, no almonds/d) and almond (ALD: 51% CHO, 16% PRO, 32% FAT, 1.5 oz. of almonds/d) diets were due to nutrients inherent to each snack and did not differ in saturated fat or cholesterol. Participants (n=48) were generally healthy adults (mean ± SD, BMI: 26 ± 3 kg/m2; HDL‐C: 55 ± 16 mg/dL) with elevated LDL‐C (149 ± 20 mg/dL). There were no significant treatment effects of ALD vs. CON on global (10.2 ± 1.8 vs. 10.0 ± 1.7%, respectively) or transporter‐specific (ABCA1: 2.8 ± 1.2vs. 2.7 ± 1.2% and non‐ABCA1: 7.4 ± 1.3 vs. 7.3 ± 1.1%, respectively) cholesterol efflux (P >0.05). However, subgroup analyses revealed that responses to diet were dependent on body mass [diet treatment × baseline BMI category (BMI <25 vs. ≥ 25 kg/m2), P=0.02] and, in normal weight participants (n=14), the almond diet preservednon‐ABCA1 efflux (8.3 ± 1.7 vs. 7.8 ± 1.0%; P=0.01) compared to the control diet; this effect did not persist in overweight and obese (n=34) participants (ALD:7.0 ± 0.2 vs. CON: 7.1 ± 0.2%; P=0.93). Body mass appears to influence responsiveness to dietary manipulations; specifically, when almonds (1.5 oz./d) are incorporated in a cholesterol‐lowering diet, individuals with a normal BMI, but not those who are overweight or obese, show improved non‐ABCA1‐mediatedcholesterol efflux, an important step in the anti‐atherogenic reverse cholesterol transport pathway.

Support or Funding Information

Supported by the Almond Board of California.
Ldlr−/− Mice Lacking PEMT Have Elevated Plasma Trimethylamine‐oxide Levels But Are Protected From High Fat Diet‐Induced Atherosclerosis.
Authors: Jacobs Rene , Zia Yumna , Rajabi Ala , Mi Si , Leonard Kelly‐Ann , Zhao Yuan‐Yuan , Field Catherine , Curtis Jonathan , van der Veen Jelske
Published: November 2023

Background

Phosphatidylethanolamine N‐methyltransferase (PEMT) is a hepatic enzyme that converts phosphatidylethanolamine into phosphatidylcholine (PC) via three methylation reactions. The PEMT pathway makes 30% of the PC required in the liver and is the only de novo source of choline. PEMT deficient mice are protected against atherosclerosis when bred with either the Ldlr−/− and Apoe−/− mice. PEMT deficiency causes decreased VLDL secretion, plasma LDL levels and homocysteine, which are risk factors for atherosclerosis. Recently, choline supplementation was shown to enhance atherosclerosis in ApoE−/− mice and was dependent on the conversion of choline to trimethylamine (TMA) by the microbial flora in the gut, which was oxidized to trimethylamine N‐oxide (TMAO) by hepatic enzymes. In addition, plasma choline and TMAO have been associated with increased risk of CVD in multiple cohort studies. The purpose of this study was to examine the effects of dietary choline supplementation on plasma TMAO levels, and investigate whether choline supplementation eliminates the atheroprotective effect of PEMT deficiency in LDLR−/− mice

Methods

We performed two sets of experiments: In first experiment, 10–12 week old Pemt+/+/Ldlr−/− and Pemt−/−/Ldlr−/− mice were fed a chow diet for 12 weeks. In the second experiment, Pemt+/+/Ldlr−/− and Pemt−/−/Ldlr−/− mice were fed a 40% high‐fat/0.5% cholesterol diet (HFD) supplemented with either 3 or 10 g/kg choline for 12 weeks.

Results

PEMT+/+/Ldlr−/− and PEMT−/−/Ldlr−/− mice do not develop atherosclerosis on chow diet and there was no difference in plasma cholesterol between genotypes. When fed a HFD, PEMT−/−/Ldlr−/− mice are protected against atherosclerosis as compared to PEMT+/+/Ldlr−/− mice. Interestingly, choline supplementation did not increase atherosclerosis in the PEMT−/−/Ldlr−/− mice. Plasma cholesterol levels were reduced in PEMT−/−/Ldlr−/−, which did not increase on choline supplementation. Surprisingly, PEMT−/−/Ldlr−/− mice have elevated TMAO levels, which was reduced to control levels by choline supplementation. Furthermore, liver histology showed that PEMT−/−/Ldlr−/− mice developed fatty liver that was improved by choline supplementation.

Conclusion

Choline supplementation does not reverse the protection of PEMT−/−/Ldlr−/− mice against atherosclerosis. PEMT−/−/Ldlr−/− mice have high TMAO levels and fatty liver on HFD. Surprisingly, choline supplementation normalized TMAO levels and reduced the fatty liver. Therefore, plasma TMAO levels are not associated with atherosclerosis but may be associated with fatty liver disease.

Support or Funding Information

Funding: ALMA, NSERC and CIHR
Loss of Dsg2 Promotes Tumorigenesis in Pancreatic Cancer Cells through ERK Activation
Authors: Huetz Katharina , Waschke Jens , Spindler Volker
Published: November 2023

The ability to maintain cell‐cell adhesion is crucial for tissue integrity and organization. Accordingly, loss of cohesiveness plays a critical role in cancer invasion and metastasis. Desmosomes are cell junctions providing strong intercellular adhesive strength and dysregulation of desmosomal constituents was shown to contribute to cancer progression through altered cell signaling pathways.

Here, we focused on the cadherin‐type adhesion molecules desmoglein 2 (Dsg2) and desmocollin 2 (Dsc2), building up the desmosomal core. siRNA‐mediated knock down of Dsg2 but not Dsc2 resulted in loss of cell cohesion and enhanced migration of pancreatic adenocarcinoma cells (AsPC‐1). We established stable Dsg2 knockdown cell lines in which loss of Dsg2 caused an increase in cell migration and enhanced invasion through extracellular matrix without influencing cell proliferation.

To identify potential pathways regulated by Dsg2, we screened major kinases and detected the activity of ERK to be significantly enhanced in Dsg2‐deficient cells. Consequently, inhibition of ERK phosphorylation in Dsg2 knockdown cells led to normalized migration. Interestingly, loss of Dsg2 was accompanied with reduced levels of the desmosomal adapter protein and transcriptional regulator plakoglobin, whereas other desmosomal molecules were not altered. Consistent with this observation, in initial experiments overexpression of plakoglobin rescued enhanced migration induced by silencing of Dsg2. These results indicate that loss of Dsg2 promotes tumorigenic behavior of pancreatic cancer cells by regulation of ERK activity and the levels of plakoglobin.
Keratin Filaments Regulate Binding Properties of the Desmosomal Adhesion Molecule Desmoglein 3
Authors: Vielmuth Franziska , Loschke Fanny , Magin Thomas M. , Waschke Jens , Spindler Volker
Published: November 2023

Desmosomes are supramolecular protein complexes required for strong intercellular adhesion. Accordingly, they are most abundant in tissues exposed to pronounced mechanical stress, such as the epidermis. In desmosomes, the interaction with adjacent cells is provided by desmosomal cadherins which are intracellularly linked with the intermediate filament cytoskeleton by several adapter proteins. Using atomic force microscopy (AFM) on living keratinocytes, we recently showed that binding forces of the desmosomal cadherin desmoglein 3 (Dsg3) are not uniformly distributed but are higher at cell borders compared to cell surface areas. In view of the compromised adhesion resulting from intermediate filament loss, we here tested the relevance of keratins, the intermediate filament proteins of epithelial cells, for the binding properties of Dsg3.

In cultured human keratinocytes, Dsg3, the adapter molecule desmoplakin and keratin filaments, assembles on the cell surface away from junctions. Murine keratinocytes lacking all keratin filaments (KtyII ko) displayed reduced intercellular adhesion compared to controls (KtyII wt). Surprisingly, the protein levels and membrane localization of Dsg3 was increased in KtyII cells. In line with this, by using AFM, a higher frequency of Dsg3‐mediated binding events was observed in Ktyll ko cells. However, the binding forces of individual Dsg3‐mediated binding events were significantly reduced compared to KtyII wt cells.

Our data for the first time show that keratins, potentially by anchorage to the desmosomal complex, regulate binding properties of desmosomal cadherins and therefore provide new insights into the mechanisms of desmosomal adhesion.
Resolution Agonist 15‐epi‐Lipoxin A4 Directs FPR2 to Expedite Healing Phase Post‐Myocardial Infarction
Authors: Kain Vasundhara , Liu Fei , Kozlovskaya Veronika , Ingle Kevin A , Khedkar Santosh , Prabhu Sumanth D , Kharlampieva Eugenia , Halade Ganesh V
Published: November 2023

Post‐myocardial infarction (MI), overactive inflammation remodels the left ventricle (LV) to cause heart failure, marked with reduced levels of resolution markers such as 15‐epi‐Lipoxin A4 (15‐epi LXA4). However, the role of 15‐epi LXA4 in acute inflammatory response and resolving phase post‐MI is unclear. We hypothesize that 15‐epi‐LXA4 with liposomal fusion (Lipo‐15‐epi‐LXA4) or free 15‐epi‐LXA4 will expedite the resolving phase in post‐MI inflammation. 8 to 12 week old male C57BL/6 mice were subjected to permanent coronary artery ligation. Lipo‐15‐epi‐LXA4 or 15‐epi‐LXA4 (1ug/kg/day) was injected 3 hours post‐MI for day (d)1 or until d5. Mice with no treatment served as MI‐control and mice with no‐MI were used as d0 naïve controls. In‐vitro experiment using peritoneal macrophages showed 15‐epi‐LXA4 activated formyl peptide receptor (FPR2/ALX) and GPR120 on alternative macrophages, but inhibited GPR40 on classical macrophages. The 15‐epi‐LXA4 injected mice displayed reduced LV‐ and lung mass‐to‐body weight ratios and increased fractional shortening at d5 post‐MI. In acute phase (d1), 15‐epi‐LXA4 primes neutrophil infiltration with a robust increase of Ccl2 (FPR2/ALX) (all p<0.05) expression compared to MI‐control group. During resolving phase (d5), 15‐epi‐LXA4 initiated the rapid clearance of neutrophils with persistent activation of FPR2/ALX in both LV and spleen with inhibition of GPR40. 15‐epi‐LXA4 increased transcripts of proresolving markers Arg‐1 and Ym‐1 at d5 post‐MI (all p<0.05) in the infarcted LV. Post‐MI splenic activation and reduced kidney inflammation was marked by an increase in expression of Mrc‐1/CD206 and Ym‐1 (both p<0.05) as well as a decreased level of NGAL and plasma creatinine, respectively in 15‐epi‐LXA4 group. In summary, 15‐epi‐LXA4 initiates the resolving phase early to remit uncontrolled inflammation post‐MI, thereby reduced LV dysfunction.

Support or Funding Information

This work was supported by grants from National Institutes of Health (NIH)‐NCCAM R00AT006704, Michigan Regional Comprehensive Metabolomics Resource Core and UAB start‐up fund to G.V.H
Serum miRNAs as potential biomarkers for early prediction of type 1 diabetes
Authors: Yin Congcong , Weiland Matthew , Li Jia , She Ruicong , Zhou Li , Mi Qingsheng
Published: November 2023

Background

The incidence of type 1 diabetes (T1D), a T cell‐mediated beta cell destructive autoimmune disease, has been increasing about 3–4% annually for several decades. Individuals at risk for T1D are diagnosed at a late stage when the possibility for disease prevention is absent. Autoantibodies (AA) to islet antigens such as islet antigen (IA)‐2, IA‐2b, and glutamate decarboxylase (GAD65) appear earlier before T1D onset and are used for early T1D prediction. However, the appearance of islet AA marks a relatively late stage of the autoimmune process and therefore is not suitable for early disease intervention. More importantly AA lack causal relationship with the pathogenesis of T1D. Therefore, there is an urgent need for better (increased specificity/sensitivity) and earlier (predating autoantibodies) markers for the prediction of AA development. MicroRNAs (miRNAs) have emerged as an important regulatory factors in pancreatic β‐cell development, homeostasis, function, and in a variety of immune cell development, differentiation and function. Our recent study showed that miRNAs regulate T1D development and serum miRNAs are potential biomarkers for T1D progression in mouse models. Our objective here is to identify specific serum miRNA biomarkers for earlier and better prediction of individuals at risk for T1D in human.

Method

We performed serum miRNA expressions profiles in 35 AA positive (IAA and ICA) non‐T1D subjects and 40 AA negative relative subjects from the Diabetes Prevention Trial‐Type 1 (DPT‐1) cohort, using the TaqMan low‐density arrays. miRNAs with changed expression level were further confirmed by a single TaqMan RT‐PCR.

Result

9 miRNAs (miR‐146a, miR‐561 and miR‐548a‐3p, miR‐184 and miR‐200a) were down‐regulated and 2 miRNAs (miR‐30c and miR‐487a) are up‐regulated in the serum of AA+ non‐T1D subjects compared to that from AA‐ subjects (two‐sample t‐test P<0.05). In addition, a cluster of five miRNAs (miR‐146a, miR‐197, miR‐193b, miR‐574‐3p, and miR‐561) was identified to clearly separate AA+ subjects from AA‐ subjects with higher sensitivity and specificity ( LASSO logistic regression). miRNA target and pathway prediction analyses revealed that some of these miRNAs are related to immune function and beta‐cell homeostasis and potentially involved in autoimmune processes.

Conclusion

We have identified distinct serum miRNA expressions profiles in AA+ subjects compared to AA‐ subjects. These serum miRNAs could serve as potential biomarkers for early prediction of autoimmune processes in individuals at risk for T1D, which need to be further confirmed in the future studies.

Support or Funding Information

NIH/NIDDK, XO1DK097691‐01A1 JDRF grants, 17‐2012‐678 and 2‐SRA‐2015‐122‐Q‐R
Lutein, But Not Other Carotenoids, Selectively Inhibits Breast Cancer Cell Growth Through Several Molecular Mechanisms
Authors: Swanson Haley M , Smith Joshua R , Gong Xiaoming , Rubin Lewis P
Published: November 2023

Introduction

The dietary carotenoid lutein is critical in eye and brain development and function. Its anticancer effects have been controversial, albeit understudied. We investigated effects of lutein in a wide range of receptor (+) and (−) breast cancer cell lines including difficult‐to‐treat ‘triple‐negative’ breast cancer.

Materials/Methods

Eight established breast cancer cell lines and primary human mammary epithelial cells (PmEC) were exposed to a concentration range of (1) carotenoids (β‐carotene, lutein, zeaxanthin, lycopene, astaxanthin); and (2) lutein + chemotherapy agents (paclitaxel, docetaxel). Cell proliferation was analyzed by MTT and EdU assays, and soft agar colony formation was assessed. Intracellular reactive oxygen species (ROS), cell cycle, and apoptosis were assayed by flow cytometry. Proteomic arrays and RT‐PCR profiling were used to evaluate changes in cellular protein phosphorylation and targeted gene expression, respectively.

Results

Lutein and lutein epoxide, and to a lesser extent lycopene, but not other carotenoids, significantly inhibited breast cancer cell growth and induced cancer cell apoptosis. Lutein had little apparent effect on PmEC cell proliferation or viability. Lutein‐mediated growth inhibition is quantitatively similar to that induced by chemotherapeutic agents tested. Moreover, lutein and chemotherapy act additively‐to‐synergistically to inhibit cell growth. We determined mechanisms for growth inhibition by lutein in triple‐negative breast cancer cells include: induction of G1 cell cycle arrest; increased intracellular ROS production; mutant and wild‐type p53 phosphorylation; and down‐regulation of several anti‐apoptotic proteins, including Bcl2.

Conclusions

Our findings demonstrate lutein (in concentrations attained in healthy diets) has anti‐tumor activities in human breast cancer acting via several molecular mechanisms. Lutein supplementation/fortification may be a promising nutriceutical preventive and/or adjunct therapeutic approach in a wide range of human breast cancer subtypes.

Support or Funding Information

Partially funded by TTUHSC El Paso Seed Grants (LPR, XG), a Scholarly Activity & Research Program student grant (HMS), and a Summer Accelerated Biomedical Research Internship (JRS).
Functional characterization of Isl2/coupTFIb activation targets in vascular development
Authors: Wang Yi‐Shan
Published: November 2023

Genetic and signal interaction that regulating the vein identity, intersegmental vessels (ISV) and cardinal vein pluses (CVP) patterning is still not fully understood. We previously identified the transcription factors Islet2 (Isl2) and CoupTFIb required for specification of the vein and ISV growth mediated by Notch pathway in zebrafish. To understand the molecular mechanisms behind the isl2/coupTFIb regulation, we performed the microarray experiments to identify the potential downstream targets. In this study, we focus on the potential activation targets and we confirmed several genes expressed in vessels during early development indicating those potential genes function in vascular development likely downstream of isl2/coupTFIb.

We selectively assay the functional relevance of one potential target, signal‐transducing adaptor protein 2 (stap2). Stap2 is identified as an adaptor protein that has been showed functions in a variety of cellular signal pathways in immune system, however, there is no description of stap2 functioning in vascular development so far. Our in‐situ hybridization results showed stap2 mRNA is expressed is expressed in developing vessels from 18S to 48 hpf stages, suggesting its roles in vasculization. Knockdown of stap2 by morpholino injection causes vascular defects, suggesting the role of stap2 in controlling ISV and CVP growth. We confirmed the specificity of stap2 MO knockdown by using 2nd MO interfere block splicing site, examining knockdown efficiency, and expressing stap2 mRNA to rescue stap2 morphants. AO staining and TUNEL assay showed that vascular defects do not caused by cell death, but due to the impairment of migration and/or proliferation by examining ISV integrity and ISV cell numbers in Tg(fli:neGFP; kdrl:mCherry) fish. To test molecular mechanisms of vascular defects in stap2 morphants, we examined the expression of vascular markers. We found that stap2 morphants showed a decreased expression of vascular markers flk and stabilin, consistent with the role of stap2 in vascular development. While loss of stap2 cause vascular defects, we expect overexpression of stap2 will enhance vascular growth. Overexpression of stap2 enhanced the fluorescent signals in vessels and the growth of ISV. These data suggest that stap2 is necessary and sufficient to promote vascular development.

We further examine the interaction between stap2 and Vegf signals, we showed stap2 is regulated by VEGF signals to control ISV growth. Together, we conclude that our microarray results identify many vascular genes acting downstream of isl2/coupTFIb pathway. We also showed that stap2 plays an important role for vascular development in zebrafish. Thus, our study provided an useful information for the regulating network in the field of vascular development.
The Dynamic Ontogenetic Structure of Mandibular Morphological Integration
Authors: Holmes Megan A , McNulty Margaret A. , Mussell Jason C. , DeLeon Valerie B.
Published: November 2023

Mammalian crania demonstrate conserved patterns of morphological integration and simultaneously possess varying magnitudes (degrees) of integration. Thus, it has been posited that plasticity in magnitudes of integration allow for adaptive diversification, while conserved patterns of integration reflect stabilizing selection within the population. This has not been widely tested in the mandible but could have profound implications for mandibular diversity. Here, we test these relationships in the mandible using a mouse model with a mutation that disturbs bone growth in the skull (Fgfr2C342Y). Pattern and magnitude of integration were compared between age‐matched wild‐type and mutant mice. The effect of growth was tested by comparing age groups within each genotype.

Micro‐CT scans were collected from wild‐type and mutant mouse skulls at three developmental stages: embryonic, peri‐weaning and adult (n=152). Three‐dimensional landmark coordinate data were collected from each mandible. Procrustes superimposition was applied to coordinate data to produce shape variables. Covariance matrices and scaled variance of eigenvalues were generated from shape variables and used to compare patterns and magnitudes of covariance, respectively. Significance was determined via permutation tests.

Patterns of integration in the mandible were conserved between genotype at each developmental stage (R‐obs<0.5; p<0.0001), while magnitude of integration was significantly higher in the mutant mouse model (p<0.001). Interestingly, when pattern was compared among age groups, integration was no longer conserved (R‐obs<0.2; p>0.05). Magnitude of integration decreased markedly with age in the wild‐type mice but increased as mutants aged (p>0.01). The way in which traits covaried (pattern) did not alter despite a perturbation in mandibular growth. The Fgfr2C342Y mutation did however, result in a significant change in magnitude of integration. Importantly, the only instance where pattern of integration altered was between developmental periods. These results support the suggestion that pattern of integration stabilizes shape covariance in a population, and different magnitudes of integration allow for plasticity in shape. Furthermore, both pattern and magnitude change throughout ontogeny, as separate functional and developmental demands occur. Future research should consider the complex influence of pattern, magnitude and development on the diversification of mandibular shape.

Support or Funding Information

Supported by NIH #R03DE019816 and Louisiana Board of Regents Traditional Enhancement Grant
Human Achilles and Equine Navicular Apparatus: A Structural and Functional Comparison of Two Premier Enthesis Organs
Authors: Osborn Michelle L , Blas‐Machado Uriel , Uhl Elizabeth W
Published: November 2023

The equine navicular apparatus has the same structural adaptations to mechanical stress as are found in the human Achilles enthesis, which is generally characterized as being the premier functional enthesis organ. At both sites, tensile mechanical stress, especially that created by dorsiflexion of the foot, is dissipated away from the osteotendinous junction by contact of the tendon with bone proximate to the actual attachment site: on the superior tuberosity of the calcaneus in humans and the navicular bone in the horse. This arrangement allows the tendon to wrap around the bone like a pulley, thus ensuring that its angle of attachment is maintained throughout various movements of the foot. It also acts as a fulcrum, providing both the Achilles and equine deep digital flexor tendon a long lever arm and, thus, a mechanical advantage for their action on the calcaneus and third phalanx, respectively. Finally, this contact allows for the transfer of compressive force from the tendon to bone before the actual insertion site. If this compressive force is excessive, damage to the bone, as is especially well‐characterized in navicular disease, will occur. Other features of functional entheses shared by both the Achilles and the navicular apparatus include: (1) a transition from the dense fibrous tissue of the tendon to un‐calcified and calcified fibrocartilage to bone that are adaptations to withstand compression and shear; (2) the presence of fibrocartilage at the site of bending of the tendon round the bone; (3) the presence of a bursa between the bone and the tendon that acts to minimize the frictional forces, and (4) the presence of a fat pad that plays a role in minimizing pressure changes in the bursa during movements of the foot, and contains pain and pressure receptors that can monitor overloading of the enthesis. The navicular enthesis organ does have a feature that, although present in other enthesis organs, is not prominent in the Achilles, which is that the deep digital flexor tendon attaches in a pit or depression within the third phalanx. This type of attachment also facilitates the dissemination of mechanical stress away from the tendon attachment site, by providing a ridge of bone as a pulley or fulcrum right before the insertion. The comparison of these two anatomically distinct structural systems demonstrates their similar adaptations to mechanical forces, thereby illustrating the important insights gained from studying anatomic convergences and cross‐species comparisons of function.
MicroRNA regulation of early mammalian development
Authors: Parchem Ronald J
Published: November 2023

The evolutionarily conserved miR‐302 family of microRNAs is expressed during early mammalian embryonic development. Here, we report that deletion of miR‐302a‐d in mice results in a fully penetrant late embryonic lethal phenotype. Knockout embryos have an anterior neural tube closure defect associated with a thickened neuroepithelium. The neuroepithelium shows increased progenitor proliferation, decreased cell death, and precocious neuronal differentiation. mRNA profiling at multiple time points during neurulation uncovers a complex pattern of changing targets over time. Overexpression of one of these targets, Fgf15, in the neuroepithelium of the chick embryo induces precocious neuronal differentiation. Compound mutants between mir‐302 and the related mir‐290 locus have a synthetic lethal phenotype prior to neurulation. Our results show that mir‐302 helps regulate neurulation by suppressing neural progenitor expansion and precocious differentiation. Furthermore, these results uncover redundant roles for mir‐290 and mir‐302 early in development.
microRNA in cardiac arrhythmias
Authors: Wang Jun , Bai Yan , Li Na , Ye Wenduo , Zhang Min , Greene Stephanie B , Tao Ye , Chen Yiping , Wehrens Xander H. T. , Martin James F
Published: November 2023

microRNAs (miRs) are small endogenous non‐coding RNAs that function in biologic processes primarily via post‐transcriptional gene silencing. Previous genome‐wide association studies and mouse studies indicated homeobox gene Pitx2 as a predisposition gene of atrial fibrillation (AF), the most common sustained cardiac arrhythmia. To identify miRs function in AF, we performed miR expression profiling and ChIP‐sequencing (ChIP‐Seq) using different Pitx2 alleles. We found that Pitx2 positively regulates miR‐17‐92 and its homologous cluster miR‐106b‐25. Both miR‐17‐92 and miR‐106b‐25 deficient mice had pacing‐induced AF under programmed stimulation. Electrocardiogram telemetry further revealed that mice with miR‐17‐92 cardiac‐specific conditional knockout (CKO) developed prolonged PR intervals whereas mice with miR‐17‐92 cardiac‐specific CKO and miR‐106b‐25 heterozygosity developed sinoatrial node dysfunction(SND). Both arrhythmias are AF risk factors in humans. Importantly, miR‐17‐92 and miR‐106b‐25 directly repress the sinoatrial node (SAN)‐specific gene expression such as Shox2 and Tbx3. Together, these findings provided a novel insight for miR function in prevention of AF. In addition, our most recent data indicated that miR‐17‐92 is active in the cardiac conduction system (CCS) and mice with miR‐17‐92 CCS‐specific CKO had cardiac arrhythmias, indicating a miR function in the CCS homeostasis.

Support or Funding Information

This work was supported by a 2012–2013 Michael Bilitch Fellowship in Cardiac Pacing and Electrophysiology from the Heart Rhythm Society (to J.W.), American Heart Association (AHA) Grant 14SDG19840000 (to J.W.), AHA Grant 12PRE11720003 (to Y.B.), AHA Grant 12BGIA12050207 (to N.L.), AHA Grant 13PRE13750003 (to W.Y.), National Institutes of Health (NIH) Grant 1F32HL105041 (to Y.T.), AHA Grant 13EIA14560061, NIH Grants R01‐HL089598 and R01‐HL091947, the Fondation Leducq Alliance for CaMKII Signaling in Heart (X.H.T.W.), NIH Grant 5R01HL118761 (to J.F.M.), NIH Grant R01DE17792 (to Y.C.), and the Vivian L. Smith foundation (J.F.M.).
Activity‐based glycosidase profiling: monitoring glycosphingolipid metabolism in health and disease
Authors: Overkleeft Herman
Published: November 2023

Activity‐based protein profiling allow the discovery and monitoring of active enzymes in their biological surroundings. An activity‐based probe (ABP) consists of a substrate analogue featuring a reactive group that binds to the enzyme (or enzyme family) of interest in a covalent and irreversible manner, as well as a reporter moiety, which can be an affinity tag, a fluorophore or a bioorthogonal tag. Enzyme families that form a covalent bond in their substrate processing are most suited for ABP design and therefore most ABP applications in the past decade have focused on ABPs for serene hydrolyses, cysteine proteases and threonine proteases. Retaining glycosidases employ a Koshland two‐step double displacement in the hydrolysis of glycosidic bonds. During the catalytic cycle a covalent bond with the substrate glycoside is formed along with expulsion of the aglycon leaving group. The natural product, cyclophellitol, is a potent mechanism‐based retaining beta‐glucosidase inhibitor that capitalises on this mechanism by forming a stable, covalent enzyme‐inhibitor adduct. Grafting a reporter molecule on cyclophellitol or its nitrogen analogue, cyclophellitol aziridine, delivers a potent and selective retaining beta‐glucosidase ABP. Variation of the cyclophellitol/cyclophellitol aziridine configuration yields ABPs selective for a variety of retaining gluycosidases including lysosomal galactocerebrosidase, lysosomal and ER alpha glucosidase and a number of retaining beta‐glucuronidases. In this contribution I will present our work on the design synthesis and application of a broad panel of retaining glycosidase ABPs. I will focus on the application of these tools in the functioning of the underlying glycosidases in health and disease, with special attention to glycosidases involved in lysosomal storage disorders.

Support or Funding Information

ERC Advanced Grand ‘CHEMBIOSPHING’ Netherlands Organization for Scientific Research
Reversible RNA Methylation In Gene Expression Regulation
Authors: He Chaun
Published: November 2023

We have discovered the first two RNA demethylases: FTO, a protein associated with human fat mass obesity and development, and ALKBH5, a protein that affects spermatogenesis in a mouse model. These two proteins catalyze oxidative demethylation of the most prevalent internal modifications of mammalian messenger RNA (mRNA) and other nuclear RNA, N6‐methyladenosine (m6A). These results indicate that reversible RNA modification could impact biological regulation analogous to the well‐known reversible DNA and histone chemical modifications. We have also identified and characterized proteins that can selectively recognize m6A‐modified mRNA and affect the translation status and lifetime of the target mRNA, as well as molecular machines that deposit the m6A methylation on nuclear RNA. Our discoveries indicate the presence of a new mode of biological regulation that depends on reversible and dynamic RNA modifications.
Snapshots Of Benzylsuccinate Synthase: Getting A Handle On Toluene Degradation
Authors: Drennan Catherine L , Funk Michael A
Published: November 2023

Anaerobic bacteria play a critical role in bioremediation of oil spills and industrial pollution. The first step in the anaerobic degradation of toluene, a major component of gasoline, is the addition of toluene to fumarate to yield benzylsuccinate. The enzyme responsible is benzylsuccinate synthase (BSS), a member of glycyl radical enzyme family, which uses free radical chemistry to break and form C‐H and C‐C bonds. Here, crystallographic snapshots of BSS are presented that allow us to consider how a glycyl radical enzyme can control substrate specificity to afford activation of the otherwise inert toluene molecule.

Support or Funding Information

This work was supported in part by the National Science Foundation Graduate Research Fellowship under Grant No. 0645960 (M.A.F.). C.L.D is a Howard Hughes Medical Institute (HHMI) Investigator.
Rqc2p and 60S ribosomal subunits mediate mRNA‐independent elongation of nascent chains
Authors: Brandman Onn
Published: November 2023

In Eukarya, stalled translation induces 40S dissociation and recruitment of the ribosome quality control complex (RQC) to the 60S subunit, which mediates nascent chain degradation. Here we report cryo‐electron microscopy structures revealing that the RQC components Rqc2p (YPL009C/Tae2) and Ltn1p (YMR247C/Rkr1) bind to the 60S subunit at sites exposed after 40S dissociation, placing the Ltn1p RING (Really Interesting New Gene) domain near the exit channel and Rqc2p over the P‐site transfer RNA (tRNA). We further demonstrate that Rqc2p recruits alanine‐ and threonine‐charged tRNA to the A site and directs the elongation of nascent chains independently of mRNA or 40S subunits. Our work uncovers an unexpected mechanism of protein synthesis, in which a protein‐‐not an mRNA‐‐determines tRNA recruitment and the tagging of nascent chains with carboxy‐terminal Ala and Thr extensions (“CAT tails”).