[The prediction value of combined serum levels of TMAO and TML for poor prognosis in patients with heart failure].

Objective: To evaluate the predictive value of combined serum levels of trimethylamine N-oxide (TMAO) and trimethyllysine (TML) for poor prognosis in patients with heart failure. Methods: This single-center prospective cohort study included hospitalized patients with heart failure and complete baseline data from the Department of Cardiology at Ruijin Hospital, Shanghai Jiao Tong University School of Medicine from June 2017 to December 2020. Patients were categorized into four groups based on median serum levels of TMAO and TML after admission: TMAO low level TML low level group (TMAO<9.7 µmol/L, TML<0.73 µmol/L), TMAO low level TML high level group (TMAO<9.7 µmol/L, TML≥0.73 µmol/L), TMAO high level TML low level group (TMAO≥9.7 µmol/L, TML<0.73 µmol/L) and TMAO high level TML high level group (TMAO≥9.7 µmol/L, TML≥0.73 µmol/L). The primary endpoint was a composite endpoint of cardiovascular death and readmission for heart failure. Multiple factor Cox regression analysis was conducted to evaluate the correlation between serum TMAO and TML levels and poor prognosis in patients with heart failure. Results: A total of 471 patients with heart failure were included, with an mean age of (62.5±12.0) years and a median follow-up time of 1.61 (1.06, 2.90) years. Multivariate Cox regression analysis showed that after adjusting for age, gender, and traditional risk factors, the TMAO high level TML high level group had a higher incidence of primary endpoint events compared to the TMAO low level TML low level group (HR=1.71, 95%CI 1.05-2.77, P=0.03). Conclusion: Elevated serum levels of both TMAO and TML can effectively predict the occurrence of long-term adverse events in patients with heart failure.

H4K20me3, H3K4me2 and H3K9me2 mediate the effect of ER on prognosis in breast cancer.

Previous studies have indicated that histone methylations act as mediators in the relationship between oestrogen receptor (ER) and breast cancer prognosis, yet the mediating role has never been assessed. Therefore, we investigated seven histone methylations (H3K4me2, H3K4me3, H3K9me1, H3K9me2, H3K9me3, H3K27me3 and H4K20me3) to determine whether they mediate the prognostic impact of ER on breast cancer. Tissue microarrays were constructed from 1045 primary invasive breast tumours, and the expressions of histone methylations were examined by immunohistochemistry. Multifactorial logistic regression was used to analyse the associations between ER and histone methylations. Cox proportional hazard model was performed to assess the relationship between histone methylations and breast cancer prognosis. The mediation effects of histone methylations were evaluated by model-based causal mediation analysis. High expressions of H3K9me1, H3K9me2, H3K4me2, H3K27me3, H4K20me3 were associated with ER positivity, while high expression of H3K9me3 was associated ER negativity. Higher H3K9me2, H3K4me2 and H4K20me3 levels were associated with better prognosis. The association between ER and breast cancer prognosis was most strongly mediated by H4K20me3 (29.07% for OS; 22.42% for PFS), followed by H3K4me2 (11.5% for OS; 10.82% for PFS) and least by H3K9me2 (9.35% for OS; 7.34% for PFS). H4K20me3, H3K4me2 and H3K9me2 mediated the relationship between ER and breast cancer prognosis, which would help to further elucidate the impact of ER on breast cancer prognosis from an epigenetic perspective and provide new ideas for breast cancer treatment.

L-NAC and L-NAC methyl ester prevent and overcome physical dependence to fentanyl in male rats.

N-acetyl-L-cysteine (L-NAC) is a proposed therapeutic for opioid use disorder. This study determined whether co-injections of L-NAC (500 µmol/kg, IV) or its highly cell-penetrant analogue, L-NAC methyl ester (L-NACme, 500 µmol/kg, IV), prevent acquisition of acute physical dependence induced by twice-daily injections of fentanyl (125 µg/kg, IV), and overcome acquired dependence to these injections in freely-moving male Sprague Dawley rats. The injection of the opioid receptor antagonist, naloxone HCl (NLX; 1.5 mg/kg, IV), elicited a series of withdrawal phenomena (i.e. behavioral and cardiorespiratory responses, hypothermia and body weight loss) in rats that received 5 or 10 injections of fentanyl and similar numbers of vehicle co-injections. With respect to the development of dependence, the NLX-precipitated withdrawal phenomena were reduced in rats that received had co-injections of L-NAC, and more greatly reduced in rats that received co-injections of L-NACme. In regard to overcoming established dependence, the NLX-precipitated withdrawal phenomena in rats that had received 10 injections of fentanyl (125 µg/kg, IV) were reduced in rats that had received co-injections of L-NAC, and more greatly reduced in rats that received co-injections of L-NACme beginning with injection 6 of fentanyl. This study provides compelling evidence that co-injections of L-NAC and L-NACme prevent the acquisition of physical dependence and overcome acquired dependence to fentanyl in male rats. The higher efficacy of L-NACme is likely due to its greater cell penetrability in brain regions mediating dependence to fentanyl and interaction with intracellular signaling cascades, including redox-dependent processes, responsible for the acquisition of physical dependence to fentanyl.

AMD1 promotes breast cancer aggressiveness via a spermidine-eIF5A hypusination-TCF4 axis.

BACKGROUND: Basal-like breast cancer (BLBC) is the most aggressive subtype of breast cancer due to its aggressive characteristics and lack of effective therapeutics. However, the mechanism underlying its aggressiveness remains largely unclear. S-adenosylmethionine decarboxylase proenzyme (AMD1) overexpression occurs specifically in BLBC. Here, we explored the potential molecular mechanisms and functions of AMD1 promoting the aggressiveness of BLBC. METHODS: The potential effects of AMD1 on breast cancer cells were tested by western blotting, colony formation, cell proliferation assay, migration and invasion assay. The spermidine level was determined by high performance liquid chromatography. The methylation status of CpG sites within the AMD1 promoter was evaluated by bisulfite sequencing PCR. We elucidated the relationship between AMD1 and Sox10 by ChIP assays and quantitative real-time PCR. The effect of AMD1 expression on breast cancer cells was evaluated by in vitro and in vivo tumorigenesis model. RESULTS: In this study, we showed that AMD1 expression was remarkably elevated in BLBC. AMD1 copy number amplification, hypomethylation of AMD1 promoter and transcription activity of Sox10 contributed to the overexpression of AMD1 in BLBC. AMD1 overexpression enhanced spermidine production, which enhanced eIF5A hypusination, activating translation of TCF4 with multiple conserved Pro-Pro motifs. Our studies showed that AMD1-mediated metabolic system of polyamine in BLBC cells promoted tumor cell proliferation and tumor growth. Clinically, elevated expression of AMD1 was correlated with high grade, metastasis and poor survival, indicating poor prognosis of breast cancer patients. CONCLUSION: Our work reveals the critical association of AMD1-mediated spermidine-eIF5A hypusination-TCF4 axis with BLBC aggressiveness, indicating potential prognostic indicators and therapeutic targets for BLBC.

Radical SAM Enzyme PylB Generates a Lysyl Radical Intermediate in the Biosynthesis of Pyrrolysine by Using SAM as a Cofactor.

Pyrrolysine, the 22nd amino acid encoded by the natural genetic code, is essential for methanogenic archaea to catabolize methylamines into methane. The structure of pyrrolysine consists of a methylated pyrroline carboxylate that is linked to the ε-amino group of the l-lysine via an amide bond. The biosynthesis of pyrrolysine requires three enzymes: PylB, PylC, and PylD. PylB is a radical S-adenosyl-l-methionine (SAM) enzyme and catalyzes the first biosynthetic step, the isomerization of l-lysine into methylornithine. PylC catalyzes an ATP-dependent ligation of methylornithine and a second l-lysine to form l-lysine-Nε-methylornithine. The last biosynthetic step is catalyzed by PylD via oxidation of the PylC product to form pyrrolysine. While enzymatic reactions of PylC and PylD have been well characterized by X-ray crystallography and in vitro studies, mechanistic understanding of PylB is still relatively limited. Here, we report the first in vitro activity of PylB to form methylornithine via the isomerization of l-lysine. We also identify a lysyl C4 radical intermediate that is trapped, with its electronic structure and geometric structure well characterized by EPR and ENDOR spectroscopy. In addition, we demonstrate that SAM functions as a catalytic cofactor in PylB catalysis rather than canonically as a cosubstrate. This work provides detailed mechanistic evidence for elucidating the carbon backbone rearrangement reaction catalyzed by PylB during the biosynthesis of pyrrolysine.

Comparative Study of the Effects of Dietary-Free and -Bound Nε-Carboxymethyllysine on Gut Microbiota and Intestinal Barrier.

Nε-carboxymethyllysine (CML) is produced by a nonenzymatic reaction between reducing sugar and ε-amino group of lysine in food and exists as free and bound forms with varying digestibility and absorption properties in vivo, causing diverse interactions with gut microbiota. The effects of different forms of dietary CML on the gut microbiota and intestinal barrier of mice were explored. Mice were exposed to free and bound CML for 12 weeks, and colonic morphology, gut microbiota, fecal short-chain fatty acids (SCFAs), intestinal barrier, and receptor for AGE (RAGE) signaling cascades were measured. The results indicated that dietary-free CML increased the relative abundance of SCFA-producing genera including Blautia, Faecalibacterium, Agathobacter, and Roseburia. In contrast, dietary-bound CML mainly increased the relative abundance of Akkermansia. Moreover, dietary-free and -bound CML promoted the gene and protein expression of zonula occludens-1 and claudin-1. Additionally, the intake of free and bound CML caused an upregulation of RAGE expression but did not activate downstream inflammatory pathways due to the upregulation of oligosaccharyl transferase complex protein 48 (AGER1) expression, indicating a delicate balance between protective and proinflammatory effects in vivo. Dietary-free and -bound CML could modulate the gut microbiota community and increase tight-junction expression, and dietary-free CML might exert a higher potential benefit on gut microbiota and SCFAs than dietary-bound CML.

Trimethyllysine Reader Proteins Exhibit Widespread Charge-Agnostic Binding via Different Mechanisms to Cationic and Neutral Ligands.

In the last 40 years, cation-π interactions have become part of the lexicon of noncovalent forces that drive protein binding. Indeed, tetraalkylammoniums are universally bound by aromatic cages in proteins, suggesting that cation-π interactions are a privileged mechanism for binding these ligands. A prominent example is the recognition of histone trimethyllysine (Kme3) by the conserved aromatic cage of reader proteins, dictating gene expression. However, two proteins have recently been suggested as possible exceptions to the conventional understanding of tetraalkylammonium recognition. To broadly interrogate the role of cation-π interactions in protein binding interactions, we report the first large-scale comparative evaluation of reader proteins for a neutral Kme3 isostere, experimental and computational mechanistic studies, and structural analysis. We find unexpected widespread binding of readers to a neutral isostere with the first examples of readers that bind the neutral isostere more tightly than Kme3. We find that no single factor dictates the charge selectivity, demonstrating the challenge of predicting such interactions. Further, readers that bind both cationic and neutral ligands differ in mechanism: binding Kme3 via cation-π interactions and the neutral isostere through the hydrophobic effect in the same aromatic cage. This discovery explains apparently contradictory results in previous studies, challenges traditional understanding of molecular recognition of tetraalkylammoniums by aromatic cages in myriad protein-ligand interactions, and establishes a new framework for selective inhibitor design by exploiting differences in charge dependence.

Acetyl-methyllysine marks chromatin at active transcription start sites.

Lysine residues in histones and other proteins can be modified by post-translational modifications that encode regulatory information1. Lysine acetylation and methylation are especially important for regulating chromatin and gene expression2-4. Pathways involving these post-translational modifications are targets for clinically approved therapeutics to treat human diseases. Lysine methylation and acetylation are generally assumed to be mutually exclusive at the same residue. Here we report cellular lysine residues that are both methylated and acetylated on the same side chain to form Nε-acetyl-Nε-methyllysine (Kacme). We show that Kacme is found on histone H4 (H4Kacme) across a range of species and across mammalian tissues. Kacme is associated with marks of active chromatin, increased transcriptional initiation and is regulated in response to biological signals. H4Kacme can be installed by enzymatic acetylation of monomethyllysine peptides and is resistant to deacetylation by some HDACs in vitro. Kacme can be bound by chromatin proteins that recognize modified lysine residues, as we demonstrate with the crystal structure of acetyllysine-binding protein BRD2 bound to a histone H4Kacme peptide. These results establish Kacme as a cellular post-translational modification with the potential to encode information distinct from methylation and acetylation alone and demonstrate that Kacme has all the hallmarks of a post-translational modification with fundamental importance to chromatin biology.

Comparison of tissue distribution of free and protein bound Nɛ-carboxymethyllysine after long-term oral administration to mice.

Nɛ-Carboxymethyl-lysine (CML) is a primary advanced glycation end product that exists in the body and food as free and bound forms with different bioavailability and physiological effects. To compare the uptake, tissue distribution, and fecal excretion of dietary free and bound CML, free or bound CML were administered to healthy mice at 10 mg CML kg-1 body weight per day for 12 weeks. The results demonstrated that free CML was significantly absorbed in serum and accumulated in the colon, ileum, lung, kidneys, heart, spleen, brain, and liver after intake of free and bound CML, whereas no statistical increase was found in the accumulation of bound CML in the serum, lung, spleen, kidneys, and liver. The colon was the main tissue for the accumulation of free and total CML. Moreover, the accumulation of free CML in tissues and organs was significantly correlated with free CML levels in serum. In conclusion, consumption of bound CML caused a higher uptake, accumulation, and fecal excretion of CML in the body than intake of free CML.

Ancestral archaea expanded the genetic code with pyrrolysine.

The pyrrolysyl-tRNA synthetase (PylRS) facilitates the cotranslational installation of the 22nd amino acid pyrrolysine. Owing to its tolerance for diverse amino acid substrates, and its orthogonality in multiple organisms, PylRS has emerged as a major route to install noncanonical amino acids into proteins in living cells. Recently, a novel class of PylRS enzymes was identified in a subset of methanogenic archaea. Enzymes within this class (ΔPylSn) lack the N-terminal tRNA-binding domain that is widely conserved amongst PylRS enzymes, yet remain active and orthogonal in bacteria and eukaryotes. In this study, we use biochemical and in vivo UAG-readthrough assays to characterize the aminoacylation efficiency and substrate spectrum of a ΔPylSn class PylRS from the archaeon Candidatus Methanomethylophilus alvus. We show that, compared with the full-length enzyme from Methanosarcina mazei, the Ca. M. alvus PylRS displays reduced aminoacylation efficiency but an expanded amino acid substrate spectrum. To gain insight into the evolution of ΔPylSn enzymes, we performed molecular phylogeny using 156 PylRS and 105 pyrrolysine tRNA (tRNAPyl) sequences from diverse archaea and bacteria. This analysis suggests that the PylRS•tRNAPyl pair diverged before the evolution of the three domains of life, placing an early limit on the evolution of the Pyl-decoding trait. Furthermore, our results document the coevolutionary history of PylRS and tRNAPyl and reveal the emergence of tRNAPyl sequences with unique A73 and U73 discriminator bases. The orthogonality of these tRNAPyl species with the more common G73-containing tRNAPyl will enable future efforts to engineer PylRS systems for further genetic code expansion.

Inter- and Intraindividual Differences in the Capacity of the Human Intestinal Microbiome in Fecal Slurries to Metabolize Fructoselysine and Carboxymethyllysine.

The advanced glycation endproduct carboxymethyllysine and its precursor fructoselysine are present in heated, processed food products and are considered potentially hazardous for human health. Upon dietary exposure, they can be degraded by human colonic gut microbiota, reducing internal exposure. Pronounced interindividual and intraindividual differences in these metabolic degradations were found in anaerobic incubations with human fecal slurries in vitro. The average capacity to degrade fructoselysine was 27.7-fold higher than that for carboxymethyllysine, and degradation capacities for these two compounds were not correlated (R2 = 0.08). Analysis of the bacterial composition revealed that interindividual differences outweighed intraindividual differences, and multiple genera were correlated with the individuals' carboxymethyllysine and fructoselysine degradation capacities (e.g., Akkermansia, Alistipes).

Anti-Inflammatory Activity of CIGB-258 against Acute Toxicity of Carboxymethyllysine in Paralyzed Zebrafish via Enhancement of High-Density Lipoproteins Stability and Functionality.

Background: Hyperinflammation is frequently associated with the chronic pain of autoimmune disease and the acute death of coronavirus disease (COVID-19) via a severe cytokine cascade. CIGB-258 (Jusvinza®), an altered peptide ligand with 3 kDa from heat shock protein 60 (HSP60), inhibits the systemic inflammation and cytokine storm, but the precise mechanism is still unknown. Objective: The protective effect of CIGB-258 against inflammatory stress of N-ε-carboxymethyllysine (CML) was tested to provide mechanistic insight. Methods: CIGB-258 was treated to high-density lipoproteins (HDL) and injected into zebrafish and its embryo to test a putative anti-inflammatory activity under presence of CML. Results: Treatment of CML (final 200 µM) caused remarkable glycation of HDL with severe aggregation of HDL particles to produce dysfunctional HDL, which is associated with a decrease in apolipoprotein A-I stability and lowered paraoxonase activity. Degradation of HDL3 by ferrous ions was attenuated by a co-treatment with CIGB-258 with a red-shift of the Trp fluorescence in HDL. A microinjection of CML (500 ng) into zebrafish embryos resulted in the highest embryo death rate, only 18% of survivability with developmental defects. However, co-injection of CIGB-258 (final 1 ng) caused the remarkable elevation of survivability around 58%, as well as normal developmental speed. An intraperitoneal injection of CML (final 250 µg) into adult zebrafish resulted acute paralysis, sudden death, and laying down on the bottom of the cage with no swimming ability via neurotoxicity and inflammation. However, a co-injection of CIGB-258 (1 µg) resulted in faster recovery of the swimming ability and higher survivability than CML alone injection. The CML alone group showed 49% survivability, while the CIGB-258 group showed 97% survivability (p < 0.001) with a remarkable decrease in hepatic inflammation up to 50%. A comparison of efficacy with CIGB-258, Infliximab (Remsima®), and Tocilizumab (Actemra®) showed that the CIGB-258 group exhibited faster recovery and swimming ability with higher survivability than those of the Infliximab group. The CIGB-258 group and Tocilizumab group showed the highest survivability, the lowest plasma total cholesterol and triglyceride level, and the infiltration of inflammatory cells, such as neutrophils in hepatic tissue. Conclusion: CIGB-258 ameliorated the acute neurotoxicity, paralysis, hyperinflammation, and death induced by CML, resulting in higher survivability in zebrafish and its embryos by enhancing the HDL structure and functionality.

Associations of plasma carnitine, lysine, trimethyllysine and glycine with incident ischemic stroke: Findings from a nested case-control study.

BACKGROUND & AIMS: Carnitine biosynthesis has been related to fatty acid oxidation, a process probably exerting neuroprotective effects. However, the role of carnitine biosynthesis in the development of ischemic stroke (IS) remains unclear. We aimed to examine the associations between plasma markers of carnitine biosynthesis and the IS risk. METHODS: We performed a case-control study nested in a community-based cohort (2013-2018, n = 16457). The study included 321 incident cases of IS and 321 controls matched by age and gender. Carnitine, lysine, trimethyllysine (TML), glycine, and their ratios were measured/calculated in the baseline plasma samples using ultra-high performance liquid chromatography-tandem mass-spectrometry (UHPLC-MS/MS). Conditional logistic regression analyses were used to calculate odds ratios (ORs) and their 95% confidence intervals (CIs). RESULTS: Plasma carnitine, lysine, TML, and glycine were not significantly associated with the IS risk, although a gradually reduced risk was observed across the increasing tertiles of glycine. Notably, the ratios of glycine/carnitine, glycine/lysine, and glycine/TML were all inversely associated with the IS risk. Compared to the lowest tertiles, the corresponding odds ratios for the highest tertiles were 0.60 (95% CI: 0.40-0.91), 0.63 (95% CI: 0.42-0.94), and 0.63 (95% CI: 0.42-0.95), respectively, after adjustment for body mass index, smoking, hypertension, family history of stroke, estimated glomerular filtration rate and total cholesterol. Repeating the analyses by excluding the first two years of follow-up did not materially alter the risk associations for the ratios of glycine/lysine and glycine/carnitine. CONCLUSIONS: Increased ratios of plasma glycine to carnitine, lysine, and TML were associated with a lower risk of incident IS. Our observational findings suggest that the homeostasis of circulating carnitine, lysine, TML, and glycine may involve in the pathogenesis of IS.

Bi-allelic variants in DOHH, catalyzing the last step of hypusine biosynthesis, are associated with a neurodevelopmental disorder.

Deoxyhypusine hydroxylase (DOHH) is the enzyme catalyzing the second step in the post-translational synthesis of hypusine [Nε-(4-amino-2-hydroxybutyl)lysine] in the eukaryotic initiation factor 5A (eIF5A). Hypusine is formed exclusively in eIF5A by two sequential enzymatic steps catalyzed by deoxyhypusine synthase (DHPS) and deoxyhypusine hydroxylase (DOHH). Hypusinated eIF5A is essential for translation and cell proliferation in eukaryotes, and all three genes encoding eIF5A, DHPS, and DOHH are highly conserved throughout eukaryotes. Pathogenic variants affecting either DHPS or EIF5A have been previously associated with neurodevelopmental disorders. Using trio exome sequencing, we identified rare bi-allelic pathogenic missense and truncating DOHH variants segregating with disease in five affected individuals from four unrelated families. The DOHH variants are associated with a neurodevelopmental phenotype that is similar to phenotypes caused by DHPS or EIF5A variants and includes global developmental delay, intellectual disability, facial dysmorphism, and microcephaly. A two-dimensional gel analyses revealed the accumulation of deoxyhypusine-containing eIF5A [eIF5A(Dhp)] and a reduction in the hypusinated eIF5A in fibroblasts derived from affected individuals, providing biochemical evidence for deficiency of DOHH activity in cells carrying the bi-allelic DOHH variants. Our data suggest that rare bi-allelic variants in DOHH result in reduced enzyme activity, limit the hypusination of eIF5A, and thereby lead to a neurodevelopmental disorder.

Diabetic nephropathy patients show hyper-responsiveness to N6-carboxymethyllysine.

The aim of this study was to evaluate the impact of N6-carboxymethyllysine (CML) on NF-κB gene expression and tumor necrosis factor (TNF) production in diabetic nephropathy. This was an observational study comprised of three groups: diabetic nephropathy (n=30), type II diabetes mellitus (n=28), and healthy volunteers (n=30). Blood samples collected from the study participants were cultured for 24 h in the presence of CML or an appropriate control. After incubation, the cultures were centrifuged to separate the cells from the conditioned media. cDNA was prepared from the cell pellet and used to quantify NF-κB gene expression by quantitative real-time polymerase chain reaction (PCR). The conditioned media were used to measure TNF production by enzyme-linked immunosorbent assay (ELISA). The CML-induced fold change in NF-κB gene expression was significantly different among the study groups (P=5.4×10-5). Also, the CML-induced fold change in TNF levels was significantly different among the three groups (P=4.3×10-8). These results imply that patients with diabetic nephropathy and type II diabetes mellitus showed an elevated response to CML.

Ketoprofen lysine salt has a better gastrointestinal and renal tolerability than ketoprofen acid: A comparative tolerability study in the Beagle dog.

Due to the widespread use of non-steroidal anti-inflammatory drugs (NSAIDs), the incidence of NSAID-associated adverse events has increased exponentially over the past decades. Ketoprofen (ketoprofen acid, KA) is a widely used NSAID and, like with other NSAIDs, its use can be associated with adverse effects that especially involve the gastrointestinal tract and the kidney. The salification of KA with L-lysine has led to the synthesis of ketoprofen lysine salt (KLS), which is characterized by higher solubility and a more rapid gastrointestinal absorption compared to KA. Previous studies have reported that KLS has also an increased gastric tolerance in vitro, and this is due to the inhibition of lipid peroxidation and reactive oxygen species scavenging effects of L-lysine. Here, we report in vivo tolerability/toxicity studies that were conducted prior seeking KLS marketing authorization, in which we compared KLS and KA safety profile, focusing in particular on the evaluation of the gastrointestinal and renal tolerability of the drugs administered orally to dogs. Our results demonstrate that KLS has an increased in vivo gastrointestinal tolerability compared to KA and show, for the first time, that KLS has also increased in vivo renal tolerability compared to KA, thus supporting the concept that L-lysine may counteract NSAID-induced oxidative stress-mediated gastrointestinal and renal injury.

Association of pentosidine and homocysteine levels with number of teeth present in Japanese postmenopausal women.

INTRODUCTION: Little is known about whether substances inducing tissue protein degeneration in the oral cavity are associated with the number of teeth present in postmenopausal women. We sought to investigate the association of urinary pentosidine and serum homocysteine levels with the number of teeth and subsequent tooth loss in Japanese postmenopausal women. MATERIALS AND METHODS: Among participants in the Nagano Cohort Study, 785 postmenopausal women (mean age, 68.1 years) participated in the present study. The number of teeth was re-counted at the time of follow-up in 610 women. Poisson regression analysis was used to investigate differences in the number of teeth among quartiles of pentosidine or homocysteine, adjusting for covariates that correlated with the number of teeth. A Cox proportional hazard model was used to evaluate the association of subsequent tooth loss with pentosidine or homocysteine levels. RESULTS: Pentosidine quartiles were not associated with the number of teeth at baseline. Participants in the highest homocysteine quartile had significantly fewer teeth at baseline than those in the third and lowest quartiles (p < 0.001 for both). Those in the second quartile had fewer teeth than those in the third (p = 0.001) and lowest (p < 0.001) quartiles. An increased risk of tooth loss during follow-up was significantly associated with higher urinary pentosidine (hazard ratio = 1.073 for 10 pmol/mgCre; p = 0.001). CONCLUSION: Postmenopausal women with higher homocysteine levels had fewer teeth at baseline. A higher pentosidine concentration increased the risk of subsequent tooth loss. High pentosidine or homocysteine concentrations may be associated with tooth loss in postmenopausal women.

Correlation Analysis of CML, sRAGE, and esRAGE and the Measure of Atherosclerosis of Coronary Heart Disease.

Objective: To investigate the correlation between CML, sRAGE, and esRAGE and the measure of atherosclerosis of coronary heart disease. Methods: From June 2019 to December 2021, there were 100 patients in all suffering from coronary heart disease (CHD) selected as the observation group. On the basis of Gensini score, they were divided into mild group (Gensini score < 12 points), moderate group (12 points ≤ Gensini score ≤60 points), and severe group (Gensini score > 60). Apart from that, 50 normal people staying in our hospital for physical examination were chosen as the control group in the meantime. N in each group was detected and compared ε-Carboxymethyl lysine (CML), soluble advanced glycation end product receptor (sRAGE), and endogenous secretory advanced glycation end product receptor (esRAGE). Pearson correlation coefficient was adapted to assay the relevance between CML, sRAGE, and esRAGE, as well as the degree of atherosclerosis in CHD. Receiver operator characteristic (ROC) curve was applied to during the evaluation of the diagnosis of CML, sRAGE, and esRAGE, as well as their combined detection of severe atherosclerosis in CHD. Results: In contrast with the control group, the level of serum CML together with sRAGE in the observation group was considerably elevated, while the level of esRAGE appeared in a downward trend (P < 0.05). The level of serum CML and sRAGE was directly proportional to the measure of atherosclerosis in CHD, while the level of esRAGE was inversely proportional to the measure of atherosclerosis in CHD (P < 0.05). That is to say that serum CML and sRAGE were positive in matter of the measure of atherosclerosis in CHD, while esRAGE negatively appertains to the measure of atherosclerosis in CHD (P < 0.05). Serum CML, sRAGE, and esRAGE could effectively diagnose severe atherosclerosis in CHD, and the combined detection sensitivity (89.79%), specificity (77.16%), accuracy (86.12%), positive predictive value (86.63%), negative predictive value (88.59%), and area under ROC curve (AUC) (0.924) were higher (P < 0.05). Conclusion: CML and sRAGE, as well as esRAGE, are bound up with the degree of atherosclerosis in CHD, which is conducive to clinical diagnosis and treatment.

High serum levels of N-epsilon-carboxymethyllysine are associated with poor coronary collateralization in type 2 diabetic patients with chronic total occlusion of coronary artery.

BACKGROUND: The formation of advanced glycation end-products (AGEs) is a crucial risk factor for the pathogenesis of cardiovascular diseases in diabetes. We investigated whether N-epsilon-carboxymethyllysine (CML), a major form of AGEs in vivo, was associated with poor coronary collateral vessel (CCV) formation in patients with type 2 diabetes mellitus (T2DM) and chronic total occlusion (CTO) of coronary artery. METHODS: This study consisted of 242 T2DM patients with coronary angiographically documented CTO. Blood samples were obtained and demographic/clinical characteristics were documented. The coronary collateralization of these patients was defined according to Rentrop or Werner classification. Serum CML levels were evaluated using ELISA assay. Receiver operating characteristic curve and multivariable regression analysis were performed. RESULTS: 242 patients were categorized into poor CCV group or good CCV group (107 vs. 135 by the Rentrop classification or 193 vs. 49 by the Werner classification, respectively). Serum CML levels were significantly higher in poor CCV group than in good CCV group (110.0 ± 83.35 vs. 62.95 ± 58.83 ng/ml by the Rentrop classification and 94.75 ± 78.29 ng/ml vs. 40.37 ± 28.69 ng/ml by Werner classification, both P < 0.001). Moreover, these CML levels were also significantly different across the Rentrop and Werner classification subgroups (P < 0.001). In multivariable logistic regression, CML levels (P < 0.001) remained independent determinants of poor CCV according to the Rentrop or Werner classification after adjustment of traditional risk factors. CONCLUSIONS: This study suggests that higher serum CML level is associated with poor collateralization in T2DM patients with CTO.

L-NAC reverses of the adverse effects of fentanyl infusion on ventilation and blood-gas chemistry.

There is an urgent need for development of drugs that are able to reverse the adverse effects of opioids on breathing and arterial blood-gas (ABG) chemistry while preserving opioid analgesia. The present study describes the effects of bolus injections of N-acetyl-L-cysteine (L-NAC, 500 µmol/kg, IV) on ventilatory parameters, ABG chemistry, Alveolar-arterial (A-a) gradient, sedation (righting reflex) and analgesia status (tail-flick latency assay) in unanesthetized adult male Sprague Dawley rats receiving a continuous infusion of fentanyl (1 µg/kg/min, IV). Fentanyl infusion elicited pronounced disturbances in (1) ventilatory parameters (e.g., decreases in frequency of breathing, tidal volume and minute ventilation), (2) ABG chemistry (decreases in pH, pO2, sO2 with increases in pCO2), (3) A-a gradient (increases that were consistent with reduced alveolar gas exchange), and (4) sedation and analgesia. Bolus injections of L-NAC given 60 and 90 min after start of fentanyl infusion elicited rapid and sustained reversal of the deleterious effects of fentanyl infusion on ventilatory parameters and ABG chemistry, whereas they did not affect the sedative or analgesic effects of fentanyl. Systemic L-NAC is approved for human use, and thus our findings raise the possibility that this biologically active thiol may be an effective compound to combat opioid-induced respiratory depression in human subjects.