bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determining the retinoic acid response element in the liver glucokinase gene promoter using deletion and linker‐scan analysis
Authors: Li Rui , Chen Guoxun 
Published: June 2021

Glucokinase is a key enzyme of hepatic glucose utilization when plasma glucose level is high. We have reported that retinoids in a liver derived lipophilic extract synergized with insulin to induce the expression of the glucokinase gene (Gck) in primary rat hepatocytes. Experiments were designed to determine the retinoic acid response element (RARE) in Gck promoter. We have shown that retinoic acid (RA) activated the minimal luciferase reporter construct containing 234‐bp (−237/−3, Gck‐234‐WT‐LUC) of the Gck promoter sequence both in primary rat hepatocytes and INS‐1 insulinoma cells. A series of reporter constructs containing overlapping 10‐ to 12‐bp scramble mutations covering the nucleotide sequence from −237 to −3 were made to narrow down the RARE to a 20‐bp region. Subsequently, a series of 5‐ to 6‐bp linker‐scan scramble mutations covering the entire 20‐bp region were made to narrow down the RARE to a 5‐bp region. RA induced Gck‐234‐WT‐LUC activity by 2.74±0.25‐fold in INS‐1 cells. The scramble mutation covering the sequence −177/−173 destroyed the RA‐induced luciferase activity. Moreover, single nucleotide mutations at −177, −176, and −175 significantly impaired the response of the reporter constructs to RA treatment. We conclude that the RA‐induced Gck transcription is mediated by a transcription activator associated with the RARE sequence covering −177/−175 of the liver Gck promoter.Grant Funding Source: American Heart Association
Knockout of CYP4f14 causes severe perturbations in vitamin E metabolism and results in tissue accumulation of vitamin E in the mouse
Authors: Bardowell Sabrina Anne , Duan Faping , Swanson Joy E. , Manor Danny , Parker Robert S. 
Published: June 2021

Vitamin E is a family of eight naturally‐occurring lipophilic antioxidants, of which one, α‐tocopherol (TOH), selectively accumulates in vertebrate tissues. Cytochrome P450‐4F2 (CYP4F2), an ω‐hydroxylase, is the only enzyme shown to metabolize vitamin E in humans. We identified CYP4f14 as a functional murine ortholog of CYP4F2, via cloning, cell culture expression and activity assays. We then investigated the effect of its deletion on vitamin E metabolism and status in vivo. Cyp4f14‐null mice exhibited substrate‐specific reductions in microsomal vitamin E‐ω‐hydroxylase capacity ranging from 93% (γ‐TOH) to 48% (γ‐tocotrienol). In vivo data obtained from metabolic cage studies showed whole‐body reductions in metabolism of γ‐TOH by 90% and 68% for δ‐ and α‐TOH. While fecal excretion of TOHs increased in null mice, partially compensating for the metabolic deficit, Cyp4f14‐null mice fed a soybean oil diet for 6 weeks hyper‐accumulated γ‐TOH in tissues but were otherwise apparently normal. We conclude that Cyp4f14 is the major, but not the only, vitamin E‐ω‐hydroxylase in mice. Its disruption significantly impairs whole‐body vitamin E metabolism and alters the widely‐conserved phenotype of selective tissue deposition of α‐TOH. This model and its derivatives should prove valuable in determining the in vivo biological potential of specific TOHs and tocotrienols. Funded by NIH DK067494.Grant Funding Source: NIH DK067494
Neural crest derivation of the bony skull of the Mexican axolotl
Authors: Piekarski Nadine , Hanken James 
Published: June 2021

Contributions of the cranial neural crest to cartilages and bones of the skull have been revealed in great detail in one amniote model using the quail‐chick‐chimeric system. Yet, the extent to which patterns of embryonic derivation are evolutionary conserved or labile remains an intriguing question, given the extensive variability in skull morphology observed among craniates. Amphibians are a non‐amniote tetrapod group with a highly derived skull morphology and ontogeny. Recent technical advances now enable us to derive fate maps at a level of detail previously known only from avian studies. We employ embryonic transplantations, using GFP‐transgenic axolotls as donors, to document the nature and extent of neural crest contribution to the adult osteocranium. Comparison of axolotl with results available from chicken, mouse and Xenopus reveals that different species show mosaics of conserved and variable patterns of embryonic derivation. The recently reported rostral inversion of neural crest‐derived adult cartilages in Xenopus is not a feature common to all amphibians, but instead may be uniquely associated with the extreme posthatching metamorphosis characteristic of most anurans.Grant Funding Source: MCZ
p300‐dependent acetylation of Histone H3 at lysine 56 is required for cardioprotection and DNA damage response
Authors: Jain Sumit , Wei JianQin , Bishopric Nanette H. 
Published: June 2021

Backgroundp300 is important for transcription‐dependent DNA damage repair. Acetylation of Histone H3 at Lysine 56 (AcH3K56) by p300 has been suggested to be important for initiation of DNA damage response.HypothesisAcetyltransferase p300 loss is causally related to reduced DNA damage response during aging and genotoxic stress.Methodsp300 was knocked down in neonatal cardiac myocytes using siRNA and compared to a non‐targeting sequence. Doxorubicin (Dox) was used to model genotoxic stress. Cycloheximide (CY)(5μg/ml) was used to assess p300 stability.ResultsIn cardiac myocytes, DOX caused a p300‐HAT activity dependent rapid and sustained stabilization of p300 protein (3.7±1.9 fold vs. control at 8h; p<0.05). AcH3K56 co localized with p300 after DOX treatment. p300 knockdown increased DOX‐induced myocyte death (26.9±13.5%; p<0.05) and caspase3 cleavage, decreased AcH3K56, blunted phosphorylation of H2AX, ATM, and BRCA1, and reduced phosphorylation and acetylation of p53. Converse effects were seen with activation of p300 by HDAC inhibitors TSA and SAHA (HDACi). Further, p300KD completely abolished HDACi mediated cardioprotection and increase in AcH3K56. This could also explain accelerated aging phenotype of mice with heterozygous p300 loss.ConclusionGenotoxic stress causes a post‐transcriptional stabilization of p300 that is required for the DNA damage response and cardioprotection.The work was supported by NIH R01‐ HL7109, the Florida Heart Research Institute and AHA Pre‐doctoral fellowship to Sumit Jain.
Interplay between signal sequence recognition and N‐terminal protein modification at the ribosome exit site
Authors: Pool Martin , Nyathi Yvonne , Forte Gabriella , Stirling Colin 
Published: June 2021

Proteins destined for secretion are targeted to the endoplasmic reticulum by N‐terminal signal sequences. In contrast, the majority of cytosolic proteins are modified at their extreme N‐termini by methionine‐aminopeptidase (MetAP) and/or N‐acetylation. Both of these processes typically occur co‐translationally soon after the nascent chain emerges from the ribosome exit site.Proteins targeted by the Signal Recognition Particle‐independent targeting pathway have a strong bias against N‐terminal processing and mutations that induce such processing inhibit translocation. Detailed examination of SRP‐dependent substrates reveals that mutations that induce N‐terminal processing have no effect on ER targeting. In the context of signal anchor proteins with a long N‐terminal cytoplasmic region, methionine processing and acetylation can occur, but has no effect on translocation. In contrast, signal anchor sequences with short N‐terminal regions are inefficiently processed at their N‐termini. This is rationalized by the finding that SRP and MetAP compete for a shared binding site on the ribosome. Furthermore, we find that additional ribosome‐associated factors regulate the differential recruitment of these two factors to secretory and cytosolic ribosome nascent chains. Hence a tightly regulated interplay exists to ensure the fidelity of the early events of nascent chain processing.This work is funded by the Biotechnology and Biological Sciences Research Council.
Allosteric regulation of protein kinase PKCζ by the N‐terminal C1 domain and small compounds to the PIF‐pocket
Authors: Biondi Ricardo M. , Schulze Jörg O. , Fröhner Wolfgang , Zhang Hua , Weber Nadja , Navratil Jeanette , Amon Sabine , Hindie Valerie , Zeuzem Stefan , Jørgensen Thomas J.D. , Alzari Pedro M. , Neimanis Sonja , Engel Matthias , Lopez-Garcia Laura A. 
Published: June 2021

Protein kinases are key mediators of cellular signaling and de‐regulation of protein kinases is the cause of diseases such as cancer and diabetes. AGC kinases are regulated by phosphorylation and by N‐ and C‐terminal regions.ObjectiveUnderstand the molecular mechanism of regulation and develop novel drugs. The PIF‐pocket, present in AGC kinases, plays a central role in the mechanism of activation by phosphorylation and small compounds binding to the PIF‐pocket can activate the protein kinase PDK1 in vitro. Here, we studied the mechanism of inhibition of atypical PKCζ using molecular biology, biochemistry, synthetic chemistry of small compounds and crystallographic methods. We found that the inhibition by the N‐terminal region cannot be explained by a simple pseudosubstrate inhibitory mechanism, that the C1 domain allosterically inhibits PKCζ activity and identified an allosteric communication between the binding site of the C1 domain and the PIF‐pocket of atypical PKCs. Finally, we developed low‐molecular‐weight compounds that bind to the PIF‐pocket and allosterically inhibit PKCζ activity.Conclusionthe work establishes a central role for the PIF‐pocket on the regulation of PKCζ and allows us to envisage development of drugs targeting the PIF‐pocket that can either activate or inhibit AGC kinases. Supported by BMBF Go‐Bio, DFG (BI 1044/4‐1 and BI 1044/2‐1) and Europrofession Foundation (Germany).
Peroxisome proliferator coactivator 1a (PGC‐1a) deficiency accelerates endothelial dysfunction during chronic angiotensin II treatment by increasing mitochondrial oxidative stress and vascular aging
Authors: Jansen Thomas , Kroeller-Schoen Swenja , Daiber Andreas , Muenzel Thomas , Schulz Eberhard 
Published: June 2021

ObjectivePGC‐1a is an important mediator of mitochondrial biogenesis and function. We have previously shown that the AMP‐activated protein kinase (AMPK) protects endothelial cells against oxidative stress by preservation of mitochondrial function in a PGC‐1a dependent manner. Since dysfunctional mitochondria might be involved in the pathogenesis of vascular disease, we investigated the effects of in vivo PGC‐1a deficiency during chronic angiotensin II (ATII) treatment.Methods and ResultsDeletion of PGC‐1a had no effect on endothelial function or mitochondrial mass in aortic tissue under basal conditions. However, chronic ATII infusion resulted in mild endothelial dysfunction, which was significantly impaired in PGC‐ 1a knockout mice. In parallel, oxidative stress was increased in aortic rings from ATII‐treated PGC‐1a knockout mice while serum antioxidative capacity was decreased. By using the mitochondrial specific superoxide dye mitoSOX and complex I inhibitor rotenone, we identified the mitochondrial respiratory chain as the major PGC‐1a dependent ROS source in vivo. In accordance with the prominent role of mitochondrial ROS for the signalling events leading to vascular aging and apoptosis, we found increased expression of p16INK4 and Chk‐2 as markers of cell senescence as well as increased TUNEL‐staining accompanied by activation of the JNK pathway in aortas from ATII treated PGC‐1a knockout mice.ConclusionsPGC‐1a deficiency impairs endothelial function during chronic ATII infusion by increasing mitochondrial ROS production, resulting in premature vascular aging and apoptosis.
CARDIOTONIC STERIODS INDUCE STRESS SIGNALING IN PREECLAMSIA: A TRANSLATIONAL APPROACH WITH IN VIVO, IN VITRO, AND PATIENT STUDIES
Authors: Uddin Mohammad Nasir , Horvat Darijana , Allen Steven R , Jones Richard O , Zawieja David C , Kuehl Thomas J 
Published: June 2021

ObjectiveCardiotonic steroids (CS): marinobufagenin (MBG), ouabain (OUB) and cinobufatalin (CINO) are endogenous inhibitors of Na+/K+ ATPase. MBG is associated with preeclampsia (preE). We evaluated the effect of CS on stress signaling in pregnant rats, cytotrophoblast (CTB), and preE patients.Methods(i) Five groups of rats were studied: nonpregnant (C, n= 10); normal pregnant (NP, n = 10); pregnant rats given saline to drink and desoxycorticosterone acetate injection (PDS; preE rat model, n = 10); NP injected with MBG (NPM, n = 10); and NP injected with CINO (NPC, n = 10). We analyzed the stress signaling in all groups. (ii) Effects of CS on stress signaling in CTB were assessed. (iii) MBG and stress proteins were assayed in urine samples from 17 PreE and 23 NP patients.Results(i) Placental expression of Gadd45a, caspase 3 & 8, sFlt‐1, sFlt‐1R, & p38 were significantly higher in PDS, NPM, and NPC rats compared to NP. (ii) Expression of Gadd45a, sFlt‐1, IL‐6, 8‐IP & p38 were significantly upregulated in ≥1nM CS‐treated cells compared to vehicle‐ and 0.1 nM‐ treated cells. RNAi‐mediated inhibition of Gadd45a attenuated CS‐induced CTB stress signaling. (iii) Urinary MBG levels were significantly higher in preE patients compared to NP. Angiogenic imbalance was observed in preE patients compared to NP.ConclusionsWe demonstrated that CS induce the stress signaling in (i) NP rats; (ii) CTB cells; and (iii) preE patients.
Microbial composition and in vitro fermentation patterns of human milk oligosaccharides and prebiotics differ between formula‐fed and sow‐reared piglets
Authors: Li Min , Laura Bauer L , Chen Xin , Wang Mei , Kuhlenschmidt Theresa B , Kuhlenschmidt Mark S , Fahey George C , Donovan Sharon M 
Published: June 2021

The effects of diet and age on in vitro fermentation of human milk oligosaccharides (HMO), lacto‐N‐neotetraose (LNnT), and three prebiotics (2:1 polydextrose / galactooligosaccharides and short‐chain fructooligosaccharides) by microbiota from the ascending colon of 9‐ and 17‐day‐old (do) formula‐fed (FF) and sow‐reared (SR) piglets were assessed. Short chain fatty acid (SCFA) concentrations were determined following 0, 2, 4, 8 and 12 h of incubation. LNnT fermentation produced more total SCFA, acetate and butyrate than the other substrates, whereas more propionate was produced from HMO. Total SCFA, acetate and propionate concentration were greater in FF and 9 do pigs, while SR produced more butyrate than FF. Microbiota was assessed by 16S rRNA gene V3 region denaturing gradient gel electrophoresis and realtime PCR. Microbial structures differed among the four groups before fermentation, with higher counts of Bifidobacterium in SR, and Clostridium cluster IV, XIVa and Bacteroides vulgatus in FF. Lactobacillus counts were higher in 9‐ than 17‐do pigs, regardless of diet. Bifidobacterium, Bacteroides, and clostridial species were increased after 8 and 12 h fermentation on most substrates. In summary, piglet diet and age affected gut microbiota composition and the fermentation patterns. HMO have potential prebiotic effects as evidenced by SCFA production and modulation of the microbiota (NIH R01 HD061929).Grant Funding Source : NIH
Nutritional Assessment of Omani Patients with diabetes and Chronic Kidney Disease a case control study
Authors: Waly Mostafa , Ali Amanat , Al-Kalbani Shabib , Al-Maskari Masoud 
Published: June 2021

BackgroundChronic kidney disease (CKD) is a serious complication in patients with chronic uncontrolled type 2 diabetes mellitus (T2DM).ObjectiveThis study aimed to evaluate the nutritional status of T2DM patients undergoing hemodialysis.Materials and MethodsA cross‐sectional study conducted in the main Renal Dialysis Center, Muscat, Oman. The subjects were 96 Omani adults undergoing hemodialysis (48 with T2DM and 48 with no T2DM diagnosis).ResultsThe study subjects (62% male and 38% female) had a comparable mean age of 51± 8 years. As judged by body mass index, 86% of patients were underweight and 14% were average weight. Base line laboratory tests were comparable for all patients with the exception of fasting glucose and glycosylated hemoglobin (HbA1C) that were higher among T2DM patients. Nutritional status was assessed using the subjective global assessment score (SGA) that revealed that in T2DM patients 22% were severely malnourished, 25% were mild to moderately malnourished and 36% were normal as compared to the other group without T2DM (8% severely malnourished, 25% mild to moderately malnourished and 67% normal).ConclusionNutritional status was well controlled in CKD patients without T2DM and it deteriorated in CKD patients with T2DM. It is suggested that an appropriate intervention program must be introduced to improve the nutritional status of CKD patients with T2DM.
Effects of Camellia‐Oil Enriched Diet on Oxidative Stress and Oxidized LDL‐C in Hypercholesterolemic Subjects
Authors: Bumrungpert Akkarach , Pavadhgul Patcharanee , Chusri Sirimano , Kalpravidh Ruchaneekorn 
Published: June 2021

Camellia oil or tea seed oil is commonly used as an adjuvant in medicine. It is rich in mono‐unsaturated fatty acids (MUFA), vitamin E and phytochemicals. The objective of this study was to determine effects of camellia oil consumption on oxidative stress and LDL‐C oxidation in hypercholesterolemic subjects. The study design was a randomized, single‐blind controlled trial. Subjects with hypercholesterolemic were randomly divided into 2 groups.The treatment group (n = 25) was provided camellia‐ oil enriched diet and the control group (n = 25) was provided diet cooked with soybean oil 3 meals/day for 8 weeks. Biomarkers of oxidative stress including glutathione (GSH) and malondialdehyde (MDA) and LDL‐C oxidation were assessed before and after intervention. Camellia oil consumption significantly decreased MDA (11.2%) whereas GSH was not changed compared with the control group. Moreover, camellia oil group demonstrated a statistically significant reduction of oxidized LDL‐C (8.7%) compared with the control group. In conclusion, these data indicate that the consumption of camellia‐ oil enriched diet could decrease oxidative stress and LDL‐C oxidation in hypercholesterolemic subjects. (Supported by Thailand Research Fund)
Relationship of cognitive function with plasma homocysteine, folate, vitamin B12 levels and nutrient intake in cognitively impaired elderly
Authors: Kim Ggotpin , Kim Hyesook , Kim Yoonsun , Kim Hee Jung , Son Jung In , Kim Seong Yoon , Chang Namsoo 
Published: June 2021

This study investigated the relationship of cognitive function with plasma homocysteine (Hcy), folate, vitamin B12 levels and nutrient intake. A total of 321 subjects, including 121 normal subjects, 100 each from mild cognitive impairment (MCI) and Alzheimerˈs disease (AD) patients participated in this study (age 60 yrs and over). Diagnostic assessments were administered using the Korean version of Consortium to Establish a Registry for Alzheimerˈs Disease. Dietary intake was assessed using 24‐hour recall. Mean plasma Hcy level was higher in AD and MCI compared to normal subjects. AD group also had higher proportion of hyperhomocysteinemia and folate deficiency. Plasma Hcy level was negatively correlated with plasma folate and vitamin B12 levels, total intake of vitamin B2, vitamin B6, folate, vitamin B12, vitamin C and vitamin E. Multiple regression analysis with covariates revealed that plasma Hcy level was negatively, whereas plasma folate level, total intake of vitamin B2, vitamin B6, folate, vitamin C, vitamin E and beta‐carotene were positively associated with cognitive function. The results suggest that plasma Hcy, B vitamins and antioxidants intake are associated with cognitive function, and plasma Hcy level is negatively correlated with B vitaminsˈ nutritional status and antioxidants intake.This work was supported by the Brain Korea 21 project.
Participation in the food stamp program, food insecurity and HIV‐disease among low income HIV+ adults in Miami
Authors: Hatsu Irene , Campa Adriana , Huffman Fatma , Johnson Paulette , Thomlison Barbara , Barr Shakira , Williams Shawn , Baum Marianna K 
Published: June 2021

ObjectiveThe objective of this pilot study is to define the relationship between participation in the food stamp program, food security and stage of disease in HIV+ adults.MethodsTwenty one HIV+ patients were consented. Demographics, dietary intake and food security status were obtained using questionnaires. Disease stage and other health parameters were obtained from laboratory reports. Anthropometrics were taken. SPSS was used for analysis.ResultsThe participants were mostly male (71%), African American (66.7%), had a high school education or lower (67%) and monthly income ≤$1,000 (66%). Although all were eligible, only about half (52%) received food stamps, and 57.1% (n=12) were food insecure. Of those receiving food stamps, 45.5% were food insecure compared to 70% of those not receiving food stamps. There was a significant positive correlation between participation in the food stamp program and feeling food secure (r=0.54, p<0.039) after controlling for age, gender, quality of life and lean body mass. Moreover, those who were food insecure had significantly lower CD4 count compared to food secure individuals (578 vs. 249 p<0.005).ConclusionFood insecurity is prevalent among HIV+ adults. Participation in the food stamp program significantly improves food security and is associated with slower HIV disease progression. A study with a larger sample size is needed to support these findings.
Genetic variation in TAS1R2 taste receptor and sweet taste perception and sugar intake
Authors: Dias Andre Gautam , El-Sohemy Ahmed 
Published: June 2021

Taste is one of the primary determinants of food intake and variation in genes affecting taste pathways may influence taste perception and food intake. The TAS1R2 protein is part of the putative TAS1R2/TAS1R3 sweet taste receptor and likely plays a primary role in detecting sugars. Our objective was to determine whether single nucleotide polymorphisms (SNPs) in the TAS1R2 gene affect sweet (sucrose) taste (n = 95) and intake of sugars (n=535). Sucrose taste thresholds were determined using a 3 alternative forced choice staircase model with solutions ranging from 9 ×10−6 to 0.5 mol/L. Genotypes for 23 SNPs in the TAS1R2 gene were extracted from an Affymetrix 6.0 chip. Sucrose and total sugar intake was calculated using a 196 item semi‐quantitative food frequency questionnaire. A general linear model was used to compute differences between genotypes. The rs12075191 (A>G) SNP was associated with sucrose taste and intake. Carriers of the A allele had lower taste thresholds (7.00 ± 1.65 vs 9.27 ± 0.63 mmol/L, p=0.058), lower total sugar intake (111.2 ± 7.3 vs 125.9 ± 2.4 grams, p = 0.05) and lower sucrose intake(41.1 ± 3.4 vs 48.7 ± 1.1 grams, p=0.03) than TT homozygotes. These results show that the rs12075191 SNP in the TAS1R2 gene modifies both sweet taste perception and sugar intake.Grant Funding Source : The Advanced Food and Materials Network