We show that
Spontaneous formation of
The site‐selective palladium‐catalyzed three‐component coupling of unactivated alkenyl carbonyl compounds, aryl‐ or alkenylboronic acids, and
- PAR ID:
- 10391583
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie
- Volume:
- 135
- Issue:
- 4
- ISSN:
- 0044-8249
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Rationale N 6‐Formyl lysine is a well‐known modification of histones and other proteins. It can also be formed as a damaged product from direct formylation of free lysine and accompanied by other lysine derivatives such as acetylated or methylated forms. In relation to the activity of cellular repair enzymes in protein turnover and to lysine metabolism, it is important to accurately quantify the overall ratio of modified lysine to free lysine.Methods N 6‐Formyl lysine was quantified using liquid chromatography/tandem mass spectrometry (LC/MS/MS) with data collected in a non‐targeted manner using positive mode electrospray ionization on a Q‐Exactive HF+Orbitrap mass spectrometer. Studies were performed with lysine and deuterated lysine spiked into protein digests and solvents to investigate the extent of spontaneous formation and matrix effects of formation ofN 6‐formyl lysine.Results N 6‐formyl lysine,N 2‐formyl lysine,N 6‐acetyl lysine, andN 2‐acetyl lysine are all formed spontaneously during sample preparation and LC/MS/MS analysis, which complicates quantification of these metabolites in biological samples.N 6‐Formyl lysine was spontaneously formed and correlated to the concentration of lysine. In the sample matrix of protein digests, 0.03% of lysine was spontaneously converted intoN 6‐formyl lysine, and 0.005% of lysine was converted intoN 6‐formyl lysine in pure run solvent.Conclusions N 6‐formyl lysine,N 6‐acetyl lysine,N 2‐formyl lysine, andN 2‐acetyl lysine needs to be subtracted from biologically formed lysine modifications when quantifying these epimetabolites in biological samples. -
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Abstract Introduction Hippocampal sclerosis of aging (HS) is a common pathology often misdiagnosed as Alzheimer's disease. We tested the hypothesis that participants with HS would have a magnetic resonance imaging (MRI)‐detectable hippocampal pattern of atrophy distinct from participants without HS, both with and without Alzheimer's disease neuropathology (ADNP).
Methods Query of the National Alzheimer's Coordinating Center database identified 198 participants with MRI and autopsy. Hippocampal subfields were segmented with FreeSurfer v6. Analysis of covariance for subfield volumes compared HS+ participants to those without HS, both with ADNP (HS–/ADNP+) and without (HS–/ADNP–).
Results HS+ participants (N = 27, 14%) showed atrophied cornu ammonis 1 (CA1; left
P < .001, ηp2 = 0.14; rightP = .001, ηp2 = 0.09) and subiculum (leftP < .001, ηp2 = 0.139; rightP = .001, ηp2 = 0.085) compared to HS–/ADNP+ (N = 100, 51%). Compared to HS–/ADNP– (N = 71, 36%), HS+ also had atrophy in subiculum (leftP < .001, ηp2 = 0.235; rightP = .002, ηp2 = 0.137) and CA1 (leftP < .001, ηp2 = 0.137; rightP = .006, ηp2 = 0.070).Discussion Subiculum and CA1 atrophy from clinical MRI may be a promising in vivo biomarker for HS.
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Summary Background Metabolomic analysis is commonly used to understand the biological underpinning of diseases such as obesity. However, our knowledge of gut metabolites related to weight outcomes in young children is currently limited.
Objectives To (1) explore the relationships between metabolites and child weight outcomes, (2) determine the potential effect of covariates (e.g., child's diet, maternal health/habits during pregnancy, etc.) in the relationship between metabolites and child weight outcomes, and (3) explore the relationship between selected gut metabolites and gut microbiota abundance.
Methods Using1H‐NMR, we quantified 30 metabolites from stool samples of 170 two‐year‐old children. To identify metabolites and covariates associated with children's weight outcomes (BMI [weight/height2], BMI
z ‐score [BMI adjusted for age and sex], and growth index [weight/height]), we analysed the1H‐NMR data, along with 20 covariates recorded on children and mothers, using LASSO and best subset selection regression techniques. Previously characterized microbiota community information from the same stool samples was used to determine associations between selected gut metabolites and gut microbiota.Results At age 2 years, stool butyrate concentration had a significant positive association with child BMI (
p ‐value = 3.58 × 10–4), BMIz ‐score (p ‐value = 3.47 × 10–4), and growth index (p ‐value = 7.73 × 10–4). Covariates such as maternal smoking during pregnancy are important to consider. Butyrate concentration was positively associated with the abundance of the bacterial genusFaecalibacterium (p ‐value = 9.61 × 10−3).Conclusions Stool butyrate concentration is positively associated with increased child weight outcomes and should be investigated further as a factor affecting childhood obesity.
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Abstract Background As sap flow research expands, new challenges such as fast sap flows or flows co-occurring with freeze/thaw cycles appear, which are not easily addressed with existing methods. In order to address these new challenges, sap flow methods capable of measuring bidirectional, high and slow sap flux densities (
F d Purpose In this study we assessed the performance of a new low-power ratio-based algorithm, the maximum heat ratio (
MHR ) method, and compare it with the widely known heat ratio (HR ) method using a cut-tree study to test it under high flows usingEucalyptus grandis trees, and a freeze/thaw experiment usingAcer saccharum trunks to test its response to fast changing stem temperatures that result in freeze/thaw cycles.Results Our results indicate that MHR and HR had a strong (R2 = 0.90) linear relationship within a
F d range of 0–45 cm3 cm−2 h−1. Using the MHR algorithm, we were able to estimate wood thermal properties and water content, while extending the measuring range of HR to approximately 0–130 (cm3cm−2 h−1). In our freeze/thaw experiment, the main discrepancy between MHR and HR was observed during freezing, where HR had consistently lowerF d (up to 10 cm3 cm−2 h−1), with respect to MHR. However, both algorithms identified similar zero flows.Conclusion Consequently, MHR can be an easy-to-implement alternative algorithm/method capable of handling extreme climatic conditions, which can also run simultaneously with HR.
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Abstract Background and aims Rice is prone to Cd uptake under aerobic soil conditions primarily due to the OsNramp5 Mn transport pathway. Unlike Cd, Mn availability in rice paddies decreases as redox potential increases. We tested whether increasing Mn concentrations in solution would decrease Cd accumulation in rice through competition between Mn and Cd for uptake and/or suppression of
OsNramp5 expression.Methods Rice was grown to maturity under Mn concentrations that spanned three orders of magnitude (0.30 to 37 μM) that corresponded to free Mn2+activities of 10–7.9to 10–5.0 M while free Cd2+activity was held as constant as achievable (10–10.2to 10–10.4 M). Plant biomass and elemental concentrations were measured in roots and shoots at each stage. Fold changes in the expression of
OsNramp5 ,OsCd1 ,OsHMA3 ,OsCCX2 , andOsYSL6 genes in vegetative and grain-filling stages of rice plants were determined.Results Competition between Mn and Cd for root uptake and accumulation in shoots was observed at the highest concentration of Mn tested.
OsNramp5 expression was significantly higher in rice plants at the vegetative stage compared to the grain-filling stage, whileOsCd1 andOsHMA3 showed the opposite. Solution Mn concentrations previously thought to be tolerable by rice grown to the vegetative stage led to Mn toxicity as plants matured.Conclusions Mn competes with Cd during uptake into rice with
OsNramp5 expression unaffected. Different translocation paths may occur for Mn and Cd within the rice plant and over the rice life cycle, withOsCCX2 correlated with shoot Cd concentration.
