METTL3 (Methyltransferase Like 3)-Dependent N6-Methyladenosine Modification on Braf mRNA Promotes Macrophage Inflammatory Response and Atherosclerosis in Mice.

BACKGROUND: Atherosclerosis is a chronic inflammatory disease, in which macrophages determine the progression of atherosclerotic plaques. However, no studies have investigated how METTL3 (methyltransferase like 3) in macrophages affects atherosclerotic plaque formation in vivo. Additionally, whether Braf mRNA is modified by METTL3-dependent N6-methyladenosine (m6A) methylation remains unknown. METHODS: We analyzed single-cell sequencing data of atherosclerotic plaques in mice fed with a high fat diet for different periods. Mettl3fl/fl Lyz2cre Apoe-/- mice and littermate control Mettl3fl/fl Apoe-/- mice were generated and fed high fat diet for 14 weeks. In vitro, we stimulated peritoneal macrophages with ox-LDL (oxidized low-density lipoprotein) and tested the mRNA and protein expression levels of inflammatory factors and molecules regulating ERK (extracellular signal-regulated kinase) phosphorylation. To find METTL3 targets in macrophages, we performed m6A-methylated RNA immunoprecipitation sequencing and m6A-methylated RNA immunoprecipitation-qPCR. Further, point mutation experiments were used to explore m6A-methylated adenine. Using RNA immunoprecipitation assay, we explored m6A methylation-writing protein bound to Braf mRNA. RESULTS: In vivo, METTL3 expression in macrophages increased with the progression of atherosclerosis. Myeloid cell-specific METTL3 deletion negatively regulated atherosclerosis progression and the inflammatory response. In vitro, METTL3 knockdown or knockout in macrophages attenuated ox-LDL-mediated ERK phosphorylation rather than JNK (c-Jun N-terminal kinase) and p38 phosphorylation and reduced the level of inflammatory factors by affecting BRAF protein expression. The negative regulation of inflammation response caused by METTL3 knockout was rescued by overexpression of BRAF. In mechanism, METTL3 targeted adenine (39725126 in chromosome 6) on the Braf mRNA. Then, YTHDF1 could bind to m6A-methylated Braf mRNA and promoted its translation. CONCLUSIONS: Myeloid cell-specific Mettl3 deficiency suppressed hyperlipidemia-induced atherosclerotic plaque formation and attenuated atherosclerotic inflammation. We identified Braf mRNA as a novel target of METTL3 in the activation of the ox-LDL-induced ERK pathway and inflammatory response in macrophages. METTL3 may represent a potential target for the treatment of atherosclerosis.

E3 ligase RNF99 negatively regulates TLR-mediated inflammatory immune response via K48-linked ubiquitination of TAB2.

Innate immunity is the first line to defend against pathogenic microorganisms, and Toll-like receptor (TLR)-mediated inflammatory responses are an essential component of innate immunity. However, the regulatory mechanisms of TLRs in innate immunity remain unperfected. We found that the expression of E3 ligase Ring finger protein 99 (RNF99) decreased significantly in peripheral blood monocytes from patients infected with Gram negative bacteria (G-) and macrophages stimulated by TLRs ligands, indicating the role of RNF99. We also demonstrated for the first time, the protective role of RNF99 against LPS-induced septic shock and dextran sodium sulfate (DSS)-induced colitis using RNF99 knockout mice (RNF99-/-) and bone marrow-transplanted mice. In vitro experiments revealed that RNF99 deficiency significantly promoted TLR-mediated inflammatory cytokine expression and activated the NF-κB and MAPK pathways in macrophages. Mechanistically, in both macrophages and HEK293 cell line with TLR4 stably transfection, RNF99 interacted with and degraded TAK1-binding protein (TAB) 2, a regulatory protein of the kinase TAK1, via the lysine (K)48-linked ubiquitin-proteasomal pathway on lysine 611 of TAB2, which further regulated the TLR-mediated inflammatory response. Overall, these findings indicated the physiological significance of RNF99 in macrophages in regulating TLR-mediated inflammatory reactions. It provided new insight into TLRs signal transduction, and offered a novel approach for preventing bacterial infections, endotoxin shock, and other inflammatory ills.

An intersegmental single-cell profile reveals aortic heterogeneity and identifies a novel Malat1+ vascular smooth muscle subtype involved in abdominal aortic aneurysm formation.

The developmental origin, anatomical location, and other factors contribute to aortic heterogeneity in a physiological state. On this basis, vascular diseases occur at different ratios based on position specificity, even with the same risk factor. However, the continuous intersegmental aortic profile has been rarely reported at the single-cell level. To reveal aortic heterogeneity, we identified 15 cell subtypes from five continuous aortic segments by marker genes and functional definitions. The EC1 subtype highly expressed Vcam1 and Scarb2 genes in the aortic arch, which were reported to be associated with atherosclerosis. The newly identified Fbn1+ fibroblasts were found highly expressed in thoracic segments. More importantly, vascular smooth muscle cells (VSMCs) demonstrated a novel composition in which VSMC 4 marked with the gene Malat1 were mainly distributed in the abdominal segment. Malat1 knockout reduced MMPs and inflammatory factor production induced by Ang II in smooth muscle cells, and the Malat1 inhibitor exerted preventive, inhibitory, and reversing effects on AngII-induced abdominal aortic aneurysm (AAA) in vivo revealed by a series of animal experiments. Single-cell analysis of AngII-induced AAA tissues treated with or without the inhibitor further clarified the key role of Malat1+VSMC in the occurrence and progression of AAA. In summary, segmental gene expression and cell subtype features in normal aorta associated with different vascular diseases might provide potential therapeutic targets.

Synthesis of stable isotope-labelled firocoxib.

Firocoxib (ML-1,785,713) is a nonsteroidal, potent, and selective COX-2 inhibitor, approved for the control of pain and inflammation associated with osteoarthritis in dogs and horses, as well as to control postoperative pain and inflammation in dogs. We employed a six-step synthesis to prepare firocoxib-[13 C6 ] in an overall yield of 35% from the commercially available bromobenzene-[13 C6 ]. The synthetic route involved the preparation of the key intermediate phenyl-13 C6 -methyl sulfide using cesium carbonate and S-methylthiourea sulfate under transition-metal free conditions. A two-step preparation of firocoxib-[13 C,2 H3 ] via the sulfinic acid derivative of firocoxib and methyl iodide-[13 C,2 H3 ] using the procedure of Gauthier and Yoshikawa was first undertaken. However, the deuterium atoms of the methyl sulfone undergo extensive exchange in aqueous media even at neutral pH. The isotope-labelled firocoxib is intended as an internal standard for bioanalyses of firocoxib from biological matrices.

Projecting prevalence, costs and evaluating simulated interventions for diabetic end stage renal disease in a Canadian population of aboriginal and non-aboriginal people: an agent based approach.

BACKGROUND: Diabetes-related end stage renal disease (DM-ESRD) is a devastating consequence of the type 2 diabetes epidemic, both of which disproportionately affect Indigenous peoples. Projecting case numbers and costs into future decades would help to predict resource requirements, and simulating hypothetical interventions could guide the choice of best practices to mitigate current trends. METHODS: An agent based model (ABM) was built to forecast First Nations and non-First Nations cases of DM-ESRD in Saskatchewan from 1980 to 2025 and to simulate two hypothetical interventions. The model was parameterized with data from the Canadian Institute for Health Information, Saskatchewan Health Administrative Databases, the Canadian Organ Replacement Register, published studies and expert judgement. Input parameters without data sources were estimated through model calibration. The model incorporated key patient characteristics, stages of diabetes and chronic kidney disease, renal replacement therapies, the kidney transplant assessment and waiting list processes, costs associated with treatment options, and death. We used this model to simulate two interventions: 1) No new cases of diabetes after 2005 and 2) Pre-emptive renal transplants carried out on all diabetic persons with new ESRD. RESULTS: There was a close match between empirical data and model output. Going forward, both incidence and prevalence cases of DM-ESRD approximately doubled from 2010 to 2025, with 250-300 new cases per year and almost 1300 people requiring RRT by 2025. Prevalent cases of First Nations people with DM-ESRD increased from 19% to 27% of total DM-ESRD numbers from 1990 to 2025. The trend in yearly costs paralleled the prevalent DM-ESRD case count. For Scenario 1, despite eliminating diabetes incident cases after 2005, prevalent cases of DM-ESRD continued to rise until 2019 before slowly declining. When all DM-ESRD incident cases received a pre-emptive renal transplant (scenario 2), a substantial increase in DM-ESRD prevalence occurred reflecting higher survival, but total costs decreased reflecting the economic advantage of renal transplantation. CONCLUSIONS: This ABM can forecast numbers and costs of DM-ESRD in Saskatchewan and be modified for application in other jurisdictions. This can aid in resource planning and be used by policy makers to evaluate different interventions in a safe and economical manner.

N-Arylsulfonyl-α-amino carboxamides are potent and selective inhibitors of the chemokine receptor CCR10 that show efficacy in the murine DNFB model of contact hypersensitivity.

Compound 1 ((4-amino-3,5-dichlorophenyl)-1-(4-methylpiperidin-1-yl)-4-(2-nitroimidazol-1-yl)-1-oxobutane-2-sulfonamido) was discovered to be a 690nM antagonist of human CCR10 Ca2+ flux. Optimization delivered (2R)-4-(2-cyanopyrrol-1-yl)-S-(1H-indol-4-yl)-1-(4-methylpiperidin-1-yl)-1-oxobutane-2-sulfonamido (eut-22) that is 300 fold more potent a CCR10 antagonist than 1 and eliminates potential toxicity, mutagenicity, and drug-drug-interaction liabilities often associated with nitroaryls and anilines. eut-22 is highly selective over other GPCR's, including a number of other chemokine receptors. Finally, eut-22 is efficacious in the murine DNFB model of contact hypersensitivity. The efficacy of this compound provides further evidence for the role of CCR10 in dermatological inflammatory conditions.

Unrelated donors are associated with improved relapse-free survival compared to related donors in patients with myelodysplastic syndrome undergoing reduced intensity allogeneic stem cell transplantation.

Reduced intensity allogeneic stem cell transplantation (RI alloSCT) is a potentially curative treatment approach for patients with myelodysplastic syndrome (MDS). It is currently unclear if older related donors are better than younger unrelated donors for patients with MDS undergoing RI alloSCT. We retrospectively studied 53 consecutive MDS patients who underwent RI alloSCT between April 2007 and June 2014 and evaluated associations between donor type and outcomes with adjustment for significant covariates. 34 patients (median age: 64 years) and 19 patients (median age: 60 years) received allografts from unrelated and related donors, respectively. Unrelated donors were younger than related donors (median age: 32 vs. 60 years, P < 0.0001). There were no significant differences in baseline disease characteristics of patients receiving allografts from related or unrelated donors. Patients who received allografts from unrelated donors had a lower relapse risk (adjusted hazard ratio [aHR] = 0.35, P = 0.012) and improved relapse-free survival (aHR = 0.47, P = 0.018). HLA mismatched unrelated donors were associated with a higher risk of grade 2-4 acute graft versus host disease (GVHD) (HR = 4.64, P = 0.002) without an accompanying increase in the risk of non-relapse mortality (P = 0.56). Unrelated donors provided a higher mean CD8 cell dose (P = 0.014) and were associated with higher median donor T cell chimerism at day 60 (P = 0.003) and day 100 (P = 0.03). In conclusion, patients with MDS who received allografts from unrelated donors had a lower risk of relapse and improved relapse-free survival when compared to patients who received allografts from related donors. These findings should be confirmed in a prospective study. Am. J. Hematol. 91:883-887, 2016. © 2016 Wiley Periodicals, Inc.

High Graft CD8 Cell Dose Predicts Improved Survival and Enables Better Donor Selection in Allogeneic Stem-Cell Transplantation With Reduced-Intensity Conditioning.

PURPOSE: To characterize the impact of graft T-cell composition on outcomes of reduced-intensity conditioned (RIC) allogeneic hematopoietic stem-cell transplantation (alloHSCT) in adults with hematologic malignancies. PATIENTS AND METHODS: We evaluated associations between graft T-cell doses and outcomes in 200 patients who underwent RIC alloHSCT with a peripheral blood stem-cell graft. We then studied 21 alloHSCT donors to identify predictors of optimal graft T-cell content. RESULTS: Higher CD8 cell doses were associated with a lower risk for relapse (adjusted hazard ratio [aHR], 0.43; P = .009) and improved relapse-free survival (aHR, 0.50; P = .006) and overall survival (aHR, 0.57; P = .04) without a significant increase in graft-versus-host disease or nonrelapse mortality. A cutoff level of 0.72 × 10(8) CD8 cells per kilogram optimally segregated patients receiving CD8(hi) and CD8(lo) grafts with differing overall survival (P = .007). Donor age inversely correlated with graft CD8 dose. Consequently, older donors were unlikely to provide a CD8(hi) graft, whereas approximately half of younger donors provided CD8(hi) grafts. Compared with recipients of older sibling donor grafts (consistently containing CD8(lo) doses), survival was significantly better for recipients of younger unrelated donor grafts with CD8(hi) doses (P = .03), but not for recipients of younger unrelated donor CD8(lo) grafts (P = .28). In addition, graft CD8 content could be predicted by measuring the proportion of CD8 cells in a screening blood sample from stem-cell donors. CONCLUSION: Higher graft CD8 dose, which was restricted to young donors, predicted better survival in patients undergoing RIC alloHSCT.

Indole RSK inhibitors. Part 1: discovery and initial SAR.

A series of inhibitors for the 90 kDa ribosomal S6 kinase (RSK) based on an 1-oxo-2,3,4,5-tetrahydro-1H-[1,4]diazepino[1,2-a]indole-8-carboxamide scaffold were identified through high throughput screening. An RSK crystal structure and exploratory SAR were used to define the series pharmacophore. Compounds with good cell potency, such as compounds 43, 44, and 55 were identified, and form the basis for subsequent kinase selectivity optimization.

Epidemiology of diabetes mellitus among First Nations and non-First Nations adults.

BACKGROUND: First Nations people in Canada experience a disproportionate burden of type 2 diabetes mellitus. To increase our understanding of this evolving epidemic, we compared the epidemiology of diabetes between First Nations and non-First Nations adults in Saskatchewan from 1980 to 2005. METHODS: We used administrative databases to perform a population-based study of diabetes frequency, incidence and prevalence in adults by ethnic background, year, age and sex. RESULTS: We identified 8275 First Nations and 82,306 non-First Nations people with diabetes from 1980 to 2005. Overall, the incidence and prevalence of diabetes were more than 4 times higher among First Nations women than among non-First Nations women and more than 2.5 times higher among First Nations men than among non-First Nations men. The number of incident cases of diabetes was highest among First Nations people aged 40-49, while the number among non-First Nations people was greatest in those aged 70 or more years. The prevalence of diabetes increased over the study period from 9.5% to 20.3% among First Nations women and from 4.9% to 16.0% among First Nations men. Among non-First Nations people, the prevalence increased from 2.0% to 5.5% among women and from 2.0% to 6.2% among men. By 2005, almost 50% of First Nations women and more than 40% of First Nations men aged 60 or older had diabetes, compared with less than 25% of non-First Nations men and less than 20% of non-First Nations women aged 80 or older. INTERPRETATION: First Nations adults are experiencing a diabetes epidemic that disproportionately affects women during their reproductive years. This ethnicity-based pattern suggests diverse underlying mechanisms that may include differences in the diabetogenic impact of gestational diabetes.

Low temperature 65Cu NMR spectroscopy of the Cu+ site in azurin.

(65)Cu central-transition NMR spectroscopy of the blue copper protein azurin in the reduced Cu(I) state, conducted at 18.8 T and 10 K, gave a strongly second order quadrupole perturbed spectrum, which yielded a (65)Cu quadrupole coupling constant of +/-71.2 +/- 1 MHz, corresponding to an electric field gradient of +/-1.49 atomic units at the copper site, and an asymmetry parameter of approximately 0.2. Quantum chemical calculations employing second order Møller-Plesset perturbation theory and large basis sets successfully reproduced these experimental results. Sensitivity and relaxation times were quite favorable, suggesting that NMR may be a useful probe of the electronic state of copper sites in proteins.

Discovery and SAR of novel Naphthyridines as potent inhibitors of spleen tyrosine kinase (SYK).

The discovery of novel 5,7-disubstituted[1,6]naphthyridines as potent inhibitors of Spleen Tyrosine Kinase (SYK) is discussed. The SAR reveals the necessity for a 7-aryl group with preference towards para substitution and that this in combination with 5-aminoalkylamino substituents further improved the potency of the compounds. The initial SAR as well as a survey of the other positions is discussed in detail.