Toll-like receptor 4 (TLR4) and TLR2 were shown to be activated by saturated fatty acids (SFAs) but inhibited by docosahexaenoic acid (DHA). However, one report suggested that SFA-induced TLR ...activation in cell culture systems is due to contaminants in BSA used for solubilizing fatty acids. This report raised doubt about proinflammatory effects of SFAs. Our studies herein demonstrate that sodium palmitate (C16:0) or laurate (C12:0) without BSA solubilization induced phosphorylation of inhibitor of nuclear factor-κB α, c-Jun N-terminal kinase (JNK), p44/42 mitogen-activated-kinase (ERK), and nuclear factor-κB subunit p65, and TLR target gene expression in THP1 monocytes or RAW264.7 macrophages, respectively, when cultured in low FBS (0.25%) medium. C12:0 induced NFκB activation through TLR2 dimerized with TLR1 or TLR6, and through TLR4. Because BSA was not used in these experiments, contaminants in BSA have no relevance. Unlike in suspension cells (THP-1), BSA-solubilized C16:0 instead of sodium C16:0 is required to induce TLR target gene expression in adherent cells (RAW264.7). C16:0-BSA transactivated TLR2 dimerized with TLR1 or TLR6 and through TLR4 as seen with C12:0. These results and additional studies with the LPS sequester polymixin B and in MyD88−/− macrophages indicated that SFA-induced activation of TLR2 or TLR4 is a fatty acid-specific effect, but not due to contaminants in BSA or fatty acid preparations.
Acylcarnitines activate proinflammatory signaling pathways Rutkowsky, Jennifer M; Knotts, Trina A; Ono-Moore, Kikumi D ...
American journal of physiology: endocrinology and metabolism,
06/2014, Letnik:
306, Številka:
12
Journal Article
Recenzirano
Odprti dostop
Incomplete β-oxidation of fatty acids in mitochondria is a feature of insulin resistance and type 2 diabetes mellitus (T2DM). Previous studies revealed that plasma concentrations of medium- and ...long-chain acylcarnitines (by-products of incomplete β-oxidation) are elevated in T2DM and insulin resistance. In a previous study, we reported that mixed D,L isomers of C12- or C14-carnitine induced an NF-κB-luciferase reporter gene in RAW 264.7 cells, suggesting potential activation of proinflammatory pathways. Here, we determined whether the physiologically relevant L-acylcarnitines activate classical proinflammatory signaling pathways and if these outcomes involve pattern recognition receptor (PRR)-associated pathways. Acylcarnitines induced the expression of cyclooxygenase-2 in a chain length-dependent manner in RAW 264.7 cells. L-C14 carnitine (5-25 μM), used as a representative acylcarnitine, stimulated the expression and secretion of proinflammatory cytokines in a dose-dependent manner. Furthermore, L-C14 carnitine induced phosphorylation of JNK and ERK, common downstream components of many proinflammatory signaling pathways including PRRs. Knockdown of MyD88, a key cofactor in PRR signaling and inflammation, blunted the proinflammatory effects of acylcarnitine. While these results point to potential involvement of PRRs, L-C14 carnitine promoted IL-8 secretion from human epithelial cells (HCT-116) lacking Toll-like receptors (TLR)2 and -4, and did not activate reporter constructs in TLR overexpression cell models. Thus, acylcarnitines have the potential to activate inflammation, but the specific molecular and tissue target(s) involved remain to be identified.
Introduction and hypothesis
No studies have been performed to examine the association of sexual activity and pelvic floor muscle (PFM) morphology or function during pregnancy. The aim of this study ...was to survey the frequency of sexual intercourse and examine the associations between the frequency of sexual intercourse and the PFM morphology in pregnant women of mainland China. The relationship between sexual intercourse frequency and stress urinary incontinence (SUI)-related symptoms was also evaluated.
Methods
Pregnant women in their first or second trimester were enrolled from January 2017 and November 2017. The morphology of the PFM was examined by transperineal ultrasound, and SUI-related symptoms were assessed by the International Consultation of Incontinence Questionnaire-Short Form (ICIQ-SF). Multivariable regression analyses were used to estimate coefficients 95% confidence intervals (
CI
) with adjustment for the possible effects of cofounders.
Results
In total, 323 pregnant women (mean age, 29.66 ± 4.32 years) were included in the analysis. Almost 49% of the women had no sexual intercourse during pregnancy. Compared with pregnant women who had no sexual intercourse, those who had sexual intercourse more than once a month had stronger LA th at rest (
β
= 0.59,
P
= 0.004 for two or three times per month;
β
= 0.59,
P
= 0.044 for weekly or more). No significant relationship was found between the frequency of sexual intercourse and any ICIQ-SF-related items.
Conclusions
Chinese women had inactive sexual intercourse during pregnancy. There is a slight association between increased sexual intercourse frequency and a thicker levator ani muscle in pregnant women. Future work may be directed at determining the causality of this association.
Metal-organic frameworks (MOFs) have attracted remarkable attention for their distinguished structural designability. Precisely controlling the particle size and improving the structural stability of ...MOF nanoparticles influence their catalytic activity significantly. In this study, six acids (nitric, hydrochloric, formic, acetic, succinic, and citric acids) were used as modulators to prepare bimetallic MIL-101 (Cr, Sn) (MIL stands for Materials of Institut Lavoisier) via a microwave-assisted hydrothermal method. Changes in volumetric, structural, stability, and catalytic properties, size, and shape of MIL-101 (Cr, Sn) were examined using scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, and N2 adsorption–desorption measurements. All modulators altered the MOF properties. Compared with other samples, acetic acid as a modulator mildly altered the MOF morphology by narrowing their particle size distribution, enhancing the specific surface area, and significantly improving their water and thermal stabilities. The addition of acetic acid was suitable for the catalytic conversion of glucose to 5-hydroxymethylfurfural (5-HMF), achieving a 43.1% 5-HMF yield with 91.4% glucose conversion in a mixed solution of γ-valerolactone and saturated salt water at 150 °C after 30 min.
Phthalate esters (PAEs) may act as estrogen receptor agonists, and their relationship with precocious puberty is a global health concern. However, their role in isolated premature thelarche (IPT) ...progression remains unclear. We conducted a cohort study investigating the relationship between IPT progression and urinary PAE metabolites. Girls with IPT aged 6-8 years were regularly followed up every three months for one year. Clinical data and urine PAE metabolite levels were collected. Participants who progressed to central precocious puberty (CPP) or early puberty (EP) had significantly higher ovarian volume, breast Tanner stage, and levels of the creatinine-adjusted urinary secondary oxidized di-2-ethylhexyl phthalate (DEHP) metabolites (Σ
DEHP). Breast Tanner stage (odds ratio OR = 7.041, p = 0.010), ovarian volume (OR = 3.603, p = 0.019), and Σ
DEHP (OR = 1.020, p = 0.005) were independent risk factors for IPT progression. For each 10 µg/g/Cr increase in the urine level of Σ
DEHP, the risk of progression from IPT to CPP/EP within one year increased by 20%. This study demonstrated that the breast Tanner stage, ovarian volume, and Σ
DEHP in urine were independent risk factors for IPT progression, and Σ
DEHP may be associated with the progression of IPT to CPP or EP.
LMNA mutations are responsible for a variety of genetic disorders, including muscular dystrophy, lipodystrophy, and certain progeroid syndromes, notably Hutchinson-Gilford Progeria. Although a number ...of clinical features of these disorders are suggestive of accelerated aging, it is not known whether cells derived from these patients exhibit cellular phenotypes associated with accelerated aging. We examined a series of isogenic skin fibroblast lines transfected with
LMNA constructs bearing known pathogenic point mutations or deletion mutations found in progeroid syndromes. Fibroblasts overexpressing mutant lamin A exhibited accelerated rates of loss of telomeres and shortened replicative lifespans, in addition to abnormal nuclear morphology. To our surprise, these abnormalities were also observed in lines overexpressing wild-type lamin A. Copy number variants are common in human populations; those involving
LMNA, whether arising meiotically or mitotically, might lead to progeroid phenotypes. In an initial pilot study of 23 progeroid cases without detectable
WRN or
LMNA mutations, however, no cases of altered
LMNA copy number were detected. Nevertheless, our findings raise a hypothesis that changes in lamina organization may cause accelerated telomere attrition, with different kinetics for overexpession of wild-type and mutant lamin A, which leads to rapid replicative senescence and progroid phenotypes.
Abstract
Estrogen can promote the acceleration of bone maturation and phthalate esters (PAEs) have estrogen-mimicking effects. We investigated whether PAEs are associated with the acceleration of ...bone age (BA) in girls with early onset of puberty (EOP). This case–control study enrolled 254 girls with EOP from the Endocrinology Department at Shenzhen Children’s Hospital between December 2018 and August 2019. Ultra-performance liquid chromatography and tandem mass spectrometry were used to analyze the 10 metabolites of PAEs (mPAEs) in urine samples. BA was measured using an artificial intelligence system. BA exceeding the chronological age (CA) by > 2 years (BA-CA ≥ 2 years) was referred to as significant BA advancement. Participants were divided into groups A (BA-CA ≥ 2 years; case group) and B (BA-CA < 2 years; control group). Propensity score matching (PSM) was performed for both groups in a 1:2 ratio with a caliper of 0.25. To identify potential dose–response relationships between PAEs exposure and BA advancement, we grouped the participants after PSM according to the tertiles of the mPAE concentrations. After PSM, 31 and 62 girls in groups A and B were selected. The concentration of Mono-ethyl phthalate (MEP) in group A was significantly higher than in group B (11.83 μg/g vs. 7.11 μg/g,
P
< 0.05); there was no significant difference in the levels of other mPAEs between the groups. The degree of BA advancement and proportion of significantly advanced BA in the lowest, middle, and highest tertiles of the MEP sequentially increased, as well as in the lowest, middle, and highest tertiles of Mono-(2-ethyl-5-carboxypentyl) phthalate; however, these were only statistically different between the highest and lowest MEP tertiles (both
P
< 0.05). For the remaining mPAEs, differences in the degree of BA advancement among the lowest, middle, and highest tertiles, as well as differences in the proportion of significantly advanced BA among the lowest, middle, and highest tertiles, were not significant (all
P
> 0.05). Our findings suggested that MEP was positively associated with BA advancement in girls with EOP. Exposure to PAEs may promote accelerated bone maturation.
Nucleotide-binding oligomerization domain-containing proteins (Nods) are intracellular pattern recognition receptors recognizing conserved moieties of bacterial peptidoglycan through their ...leucine-rich repeats domain. The agonists for Nods activate proinflammatory signaling pathways, including NF-κB pathways. The results from our previous studies showed that the activation of TLR4 and TLR2, leucine-rich repeat-containing pattern recognition receptors, were differentially modulated by saturated and n-3 polyunsaturated fatty acids in macrophages and dendritic cells. Here, we show the differential modulation of NF-κB activation and interleukin-8 (IL-8) expression in colonic epithelial cells HCT116 by saturated and unsaturated fatty acids mediated through Nods proteins. Lauric acid (C12:0) dose dependently activated NF-κB and induced IL-8 expression in HCT116 cells, which express both Nod1 and Nod2, but not detectable amounts of TLR2 and TLR4. These effects of lauric acid were inhibited by dominant negative forms of Nod1 or Nod2, but not by dominant negative forms of TLR2, TLR4, and TLR5. The effects of lauric acid were also attenuated by small RNA interference targeting Nod1 or Nod2. In contrast, polyunsaturated fatty acids, especially n-3 polyunsaturated fatty acids, inhibited the activation of NF-κB and IL-8 expression induced by lauric acid or known Nods ligands in HCT116. Furthermore, lauric acid induced, but docosahexaenoic acid inhibited lauric acid- or Nod2 ligand MDP-induced, Nod2 oligomerization in HEK293T cells transfected with Nod2. Together, these results provide new insights into the role of dietary fatty acids in modulating inflammation in colon epithelial cells. The results suggest that Nods may be involved in inducing sterile inflammation, one of the key etiological conditions in the development of many chronic inflammatory diseases.
Nod2 is an intracellular pattern recognition receptor that detects a conserved moiety of bacterial peptidoglycan and subsequently
activates proinflammatory signaling pathways. Mutations in Nod2 have ...been implicated to be linked to inflammatory granulomatous
disorders, such as Crohn's disease and Blau syndrome. Many phytochemicals possess anti-inflammatory properties. However, it
is not known whether any of these phytochemicals might modulate Nod2-mediated immune responses and thus might be of therapeutic
value for the intervention of these inflammatory diseases. In this report, we demonstrate that curcumin, a polyphenol found
in the plant Curcuma longa , and parthenolide, a sesquiterpene lactone, suppress both ligand-induced and lauric acid-induced Nod2 signaling, leading
to the suppression of nuclear factor-κB activation and target gene interleukin-8 expression. We provide molecular and biochemical
evidence that the suppression is mediated through the inhibition of Nod2 oligomerization and subsequent inhibition of downstream
signaling. These results demonstrate for the first time that curcumin and parthenolide can directly inhibit Nod2-mediated
signaling pathways at the receptor level and suggest that Nod2-mediated inflammatory responses can be modulated by these phytochemicals.
It remains to be determined whether these phytochemicals possess protective or therapeutic efficacy against Nod2-mediated
inflammatory disorders.
DNA double-strand breaks (DSBs) are a highly mutagenic and potentially lethal damage that occurs in all organisms. Mammalian cells repair DSBs by homologous recombination and non-homologous end ...joining, the latter requiring DNA-dependent protein kinase (DNA-PK). Werner syndrome is a disorder characterized by genomic instability, aging pathologies and defective WRN, a RecQ-like helicase with exonuclease activity. We show that WRN interacts directly with the catalytic subunit of DNA-PK (DNA-PKCS), which inhibits both the helicase and exonuclease activities of WRN. In addition we show that WRN forms a stable complex on DNA with DNA-PKCS and the DNA binding subunit Ku. This assembly reverses WRN enzymatic inhibition. Finally, we show that WRN is phosphorylated in vitro by DNA-PK and requires DNA-PK for phosphorylation in vivo, and that cells deficient in WRN are mildly sensitive to ionizing radiation. These data suggest that DNA-PK and WRN may function together in DNA metabolism and implicate WRN function in non-homologous end joining.
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