Background: The Zucker Diabetic Fatty (ZDF) rat is a popular model of type 2 diabetes as it develops pathologic changes in the kidney similar to human diabetic nephropathy. To identify metabolic ...pathways linked to pathologic features MALDI mass spectrometry imaging (MSI) can be a powerful platform. However, quantification of metabolites from MALDI-MSI is very challenging. Our MSI-DeepPath computational platform enables spatial quantitation of metabolites from any tissue section size.
Methods: Control and obese ZDF male rats (age 6mo, n=5/group) were studied. Spatial metabolomics analysis of kidney tissue sections was performed using MALDI-MSI at 20 µm resolution. Metabolites were detected at mass accuracy <2 ppm using Q-Exactive orbitrap MS followed by annotations using METASPACE. SygnaMap’s MSI-DeepPath computational platform was used to quantify the annotated metabolites.
Results: Of 400 metabolites annotated at m/z range 70-500 Da the top features were selected using t-test, p value and fold change analysis. The top 20 biomarkers that separated ZDF from controls included glucose, serine, histidine, and glutamate. The most significantly upregulated metabolite was tyrosinamide (8.2-fold, p=8.02 x 10-9 ). The most significant downregulated metabolite was L-threonine (0.3-fold, p=2.03 x 10-9). Pathway analysis revealed that aminoacyl-tRNA biosynthesis, galactose, glyoxylate and dicarboxylate metabolic pathways can discriminate healthy from diabetic kidney samples.
Conclusion: MSIDeepPath enables quantification of spatial metabolomics of tissue sections using MALDI-MSI data. This new tool can be applied across normal and diseased samples allowing for robust statistical analysis of spatial omics data. Using MSI-DeepPath on kidney sections from the ZDF rat we identified regulation of metabolites linked to key pathways of diabetic kidney disease.
Disclosure
L.Hejazi: None. S.Sharma: None. A.Ruiz: None. G.Zhang: None. F.C.Tucci: None. K.Sharma: Advisory Panel; Reata Pharmaceuticals, Inc., Otsuka America Pharmaceutical, Inc.
Funding
National Institutes of Health (1R43DK130732-01A1)
Diabetic kidney disease (DKD) can lead to end-stage kidney disease (ESKD) and mortality; however, few mechanistic biomarkers are available for high-risk patients, especially those without ...macroalbuminuria. Urine from participants with diabetes from the Chronic Renal Insufficiency Cohort (CRIC) study, the Singapore Study of Macro-angiopathy and Micro-vascular Reactivity in Type 2 Diabetes (SMART2D), and the American Indian Study determined whether urine adenine/creatinine ratio (UAdCR) could be a mechanistic biomarker for ESKD. ESKD and mortality were associated with the highest UAdCR tertile in the CRIC study and SMART2D. ESKD was associated with the highest UAdCR tertile in patients without macroalbuminuria in the CRIC study, SMART2D, and the American Indian study. Empagliflozin lowered UAdCR in nonmacroalbuminuric participants. Spatial metabolomics localized adenine to kidney pathology, and single-cell transcriptomics identified ribonucleoprotein biogenesis as a top pathway in proximal tubules of patients without macroalbuminuria, implicating mTOR. Adenine stimulated matrix in tubular cells via mTOR and stimulated mTOR in mouse kidneys. A specific inhibitor of adenine production was found to reduce kidney hypertrophy and kidney injury in diabetic mice. We propose that endogenous adenine may be a causative factor in DKD.
Background and Purpose
Targeting α7 nicotinic ACh receptors (nAChRs) in neuroinflammatory disorders including acute ischaemic stroke holds significant therapeutic promise. However, therapeutically ...relevant signalling mechanisms remain unidentified. Activation of neuronal α7 nAChRs triggers ionotropic signalling, but there is limited evidence for it in immunoglial tissues. The α7 ligands which are effective in reducing acute ischaemic stroke damage promote α7 ionotropic activity, suggesting a link between their therapeutic effects for treating acute ischaemic stroke and activation of α7 conductive states.
Experimental Approach
This hypothesis was tested using a transient middle cerebral artery occlusion (MCAO) model of acute ischaemic stroke, NS6740, a known selective non‐ionotropic agonist of α7 nAChRs and 4OH‐GTS‐21, a partial α7 agonist. NS6740‐like ligands exhibiting low efficacy/potency for ionotropic activity will be referred to as non‐ionotropic agonists or “metagonists”.
Key Results
4OH‐GTS‐21, used as a positive control, significantly reduced neurological deficits and brain injury after MCAO as compared to vehicle and NS6740. By contrast, NS6740 was ineffective in identical assays and reversed the effects of 4OH‐GTS‐21 when these compounds were co‐applied. Electrophysiological recordings from acute hippocampal slices obtained from NS6740‐injected animals demonstrated its remarkable brain availability and protracted effects on α7 nAChRs as evidenced by sustained (>8 h) alterations in α7 ionotropic responsiveness.
Conclusion and Implications
These results suggest that α7 ionotropic activity may be obligatory for therapeutic efficacy of α7 ligands after acute ischaemic stroke yet, highlight the potential for selective application of α7 ligands to disease states based on their mode of receptor activation.
Highlights • TAK-242 prevents LPS evoked TNF release from RAW267.4 cells and male and female macrophages. • IV, IT, and IP TAK-242 administration prevents LPS-induced allodynia in males. • TLR4 ...deficiency and TAK-242 treatment prevents the delayed onset of formalin-induced tactile allodynia in both sexes. • TAK-242 does not reverse established tactile allodynia in the current experiments.
NASH causes a tremendous health care burden in the United States. A glucagon-like peptide-1 agonist, semaglutide (Sema), treatment resulted in hepatic steatosis reduction in clinical trials of NASH. ...Lysophosphatidic acid receptor 1 antagonists are known to have antifibrotic effects in several organs. We tested Sema and a novel lysophosphatidic acid receptor 1 antagonist, EPGN2154, individually and in combination to evaluate their efficacy for NASH remission in preclinical models.
In the present study, we used (1) C57Bl6/J wild-type mice fed on a high-fat, high-carbohydrate (HFHC) diet for 16 weeks and (2) leptin-deficient mice (ob/ob) fed on an Amylin liver NASH diet for 16 weeks. After 16 weeks, the mice were randomly distributed in equal numbers in (1) no-drug, (2) EPGN2154, (3) Sema, and (4) EPGN2154+Sema treatment groups for 8 additional weeks at a dosage of 10 mg/kg body weight for EPGN2154 (oral gavage, 5 days a week) and 6.17 μg/kg body weight of Sema (subcutaneous injection every alternate day, 3 days a week).
In the wild-type-high-fat, high-carbohydrate model, we observed the most body weight loss in the EPGN2154+Sema combination group compared to the other treatment groups. All groups led to a significant reduction in alanine transaminase levels when compared to high-fat, high-carbohydrate-fed wild type. However, no significant difference in alanine transaminase levels was observed among the treatment groups. In the ob/ob mice study, Sema did not cause body weight loss. Moreover, the EPGN2154 and the combination groups had a lower NAFLD Activity Score and incidence of advanced-stage hepatic fibrosis than the Sema group.
EPGN2154 demonstrated a hepato-protective effect independent of body weight loss in preclinical NASH models.
The lysophosphatidic acid receptor 1 (LPAR1) is mechanistically implicated in both tumor metastasis and tissue fibrosis. Previously, metastasis was increased when fulminant fibrosis was first induced ...in mice, suggesting a direct connection between these processes. The current report examined the extent of metastasis-induced fibrosis in breast cancer model systems, and tested the metastasis preventive efficacy and fibrosis attenuation of antagonists for LPAR1 and Idiopathic Pulmonary Fibrosis (IPF) in breast and ovarian cancer models. Staining analysis demonstrated only focal, low-moderate levels of fibrosis in lungs from eleven metastasis model systems. Two orally available LPAR1 antagonists, SAR100842 and EPGN9878, significantly inhibited breast cancer motility to LPA
. Both compounds were negative for metastasis prevention and failed to reduce fibrosis in the experimental MDA-MB-231T and spontaneous murine 4T1
breast cancer metastasis models. SAR100842 demonstrated only occasional reductions in invasive metastases in the SKOV3 and OVCAR5 ovarian cancer experimental metastasis models. Two approved drugs for IPF, nintedanib and pirfenidone, were investigated. Both were ineffective at preventing MDA-MB-231T metastasis, with no attenuation of fibrosis. In summary, metastasis-induced fibrosis is only a minor component of metastasis in untreated progressive breast cancer. LPAR1 antagonists, despite
evidence of specificity and efficacy, were ineffective
as oral agents, as were approved IPF drugs. The data argue against LPAR1 and fibrosis as monotherapy targets for metastasis prevention in triple-negative breast cancer and ovarian cancer.
The discovery of novel uracil phenylethylamines bearing a butyric acid as potent human gonadotropin-releasing hormone receptor (hGnRH-R) antagonists is described. A major focus of this optimization ...was to improve the CYP3A4 inhibition liability of these uracils while maintaining their GnRH-R potency. R-4-{2-5-(2-Fluoro-3-methoxyphenyl)-3-(2-fluoro-6-trifluoromethylbenzyl)-4-methyl-2,6-dioxo-3,6-dihydro-2H-pyrimidin-1-yl-1-phenylethylamino}butyric acid sodium salt, 10b (elagolix), was identified as a potent and selective hGnRH-R antagonist. Oral administration of 10b suppressed luteinizing hormone in castrated macaques. These efforts led to the identification of 10b as a clinical compound for the treatment of endometriosis.
Intermolecular alkylation of the aziridinyl oxazole 20 using PhSO(2)CH(2)CH(2)OTf is possible despite the presence of potentially nucleophilic aziridine nitrogen. The resulting oxazolium salt 22 ...reacts with BnNMe(3)(+)CN(-) to produce the azomethine ylide 24b via electrocyclic ring opening of an oxazoline 23b. Internal cycloaddition affords 26 in 66% yield. After saponification and base-induced cleavage of the N-phenylsulfonylethyl group, conventional cyclization provides access to 33. Deprotection and DDQ oxidation completes the synthesis of the aziridinomitosene derivative 9b. The starting cis-disubstituted aziridine ester 16 can be prepared by the aza-Darzens reaction of 15 with tert-butyl chloroacetate.
Stereocontrolled Synthesis of (−)-Macrolactin A Marino, Joseph P; McClure, Michael S; Holub, David P ...
Journal of the American Chemical Society,
02/2002, Letnik:
124, Številka:
8
Journal Article
Recenzirano
The total synthesis of (−)-macrolactin A, a 24-membered macrolide, has been achieved using a newly developed 1,3-diol synthon for the introduction of two key stereogenic centers. The synthon was ...derived from sequential use of the Noyori asymmetric reduction followed by chiral sulfoxide methodology. Tellurium-derived cuprate organometallics offered an efficient and highly stereoselective means for installation of the C8 Z/E-diene, while the C15 E/E-segment was derived from a Julia−Lythgoe olefination. Yamaguchi lactonization was used to secure the macrocycle in a convergent approach with the longest linear sequence of 19 steps from Noyori alcohol 6.
SAR of lead benzothiophene H(1)-antihistamine 2 was explored to identify backup candidates with suitable pharmacokinetic profiles for an insomnia program. Several potent and selective ...H(1)-antihistamines with a range of projected half-lives in humans were identified. Compound 16d had a suitable human half-life as demonstrated in a human microdose study, but variability in pharmacokinetic profile, attributed to metabolic clearance, prevented further development of this compound. Compound 28b demonstrated lower predicted clearance in preclinical studies, and may represent a more suitable backup compound.
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