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Nature Chemical Biology Oct 2020The NUDIX hydrolase NUDT15 was originally implicated in sanitizing oxidized nucleotides, but was later shown to hydrolyze the active thiopurine metabolites,...
The NUDIX hydrolase NUDT15 was originally implicated in sanitizing oxidized nucleotides, but was later shown to hydrolyze the active thiopurine metabolites, 6-thio-(d)GTP, thereby dictating the clinical response of this standard-of-care treatment for leukemia and inflammatory diseases. Nonetheless, its physiological roles remain elusive. Here, we sought to develop small-molecule NUDT15 inhibitors to elucidate its biological functions and potentially to improve NUDT15-dependent chemotherapeutics. Lead compound TH1760 demonstrated low-nanomolar biochemical potency through direct and specific binding into the NUDT15 catalytic pocket and engaged cellular NUDT15 in the low-micromolar range. We also employed thiopurine potentiation as a proxy functional readout and demonstrated that TH1760 sensitized cells to 6-thioguanine through enhanced accumulation of 6-thio-(d)GTP in nucleic acids. A biochemically validated, inactive structural analog, TH7285, confirmed that increased thiopurine toxicity takes place via direct NUDT15 inhibition. In conclusion, TH1760 represents the first chemical probe for interrogating NUDT15 biology and potential therapeutic avenues.
Topics: Binding Sites; Cell Line; Drug Design; Drug Development; Escherichia coli; Humans; Inorganic Pyrophosphatase; Models, Molecular; Protein Binding; Protein Conformation; Pyrophosphatases; Structure-Activity Relationship
PubMed: 32690945
DOI: 10.1038/s41589-020-0592-z -
Cell Death & Disease Feb 2023Impaired protein N-glycosylation leads to the endoplasmic reticulum (ER) stress, which triggers adaptive survival or maladaptive apoptosis in renal tubules in diabetic...
Impaired protein N-glycosylation leads to the endoplasmic reticulum (ER) stress, which triggers adaptive survival or maladaptive apoptosis in renal tubules in diabetic kidney disease (DKD). Therapeutic strategies targeting ER stress are promising for the treatment of DKD. Here, we report a previously unappreciated role played by ENTPD5 in alleviating renal injury by mediating ER stress. We found that ENTPD5 was highly expressed in normal renal tubules; however, ENTPD5 was dynamically expressed in the kidney and closely related to pathological DKD progression in both human patients and mouse models. Overexpression of ENTPD5 relieved ER stress in renal tubular cells, leading to compensatory cell proliferation that resulted in hypertrophy, while ENTPD5 knockdown aggravated ER stress to induce cell apoptosis, leading to renal tubular atrophy and interstitial fibrosis. Mechanistically, ENTPD5-regulated N-glycosylation of proteins in the ER to promote cell proliferation in the early stage of DKD, and continuous hyperglycemia activated the hexosamine biosynthesis pathway (HBP) to increase the level of UDP-GlcNAc, which driving a feedback mechanism that inhibited transcription factor SP1 activity to downregulate ENTPD5 expression in the late stage of DKD. This study was the first to demonstrate that ENTPD5 regulated renal tubule cell numbers through adaptive proliferation or apoptosis in the kidney by modulating the protein N-glycosylation rate in the ER, suggesting that ENTPD5 drives cell fate in response to metabolic stress and is a potential therapeutic target for renal diseases.
Topics: Animals; Humans; Mice; Glycosylation; Kidney; Kidney Tubules; Oncogene Proteins; Pyrophosphatases; Endoplasmic Reticulum Stress
PubMed: 36849424
DOI: 10.1038/s41419-023-05685-4 -
Communications Biology Nov 2020Guanosine 3',5'-bis(pyrophosphate) (ppGpp) functions as a second messenger in bacteria to adjust their physiology in response to environmental changes. In recent years,...
Guanosine 3',5'-bis(pyrophosphate) (ppGpp) functions as a second messenger in bacteria to adjust their physiology in response to environmental changes. In recent years, the ppGpp-specific hydrolase, metazoan SpoT homolog-1 (Mesh1), was shown to have important roles for growth under nutrient deficiency in Drosophila melanogaster. Curiously, however, ppGpp has never been detected in animal cells, and therefore the physiological relevance of this molecule, if any, in metazoans has not been established. Here, we report the detection of ppGpp in Drosophila and human cells and demonstrate that ppGpp accumulation induces metabolic changes, cell death, and eventually lethality in Drosophila. Our results provide the evidence of the existence and function of the ppGpp-dependent stringent response in animals.
Topics: Animals; Bacteria; Drosophila melanogaster; Guanosine Pentaphosphate; Guanosine Tetraphosphate; Pyrophosphatases; Second Messenger Systems; Signal Transduction
PubMed: 33188280
DOI: 10.1038/s42003-020-01368-4 -
Bone Dec 2021Awareness for hypophosphatemic rickets has increased in the last years, based on the availability of specific medical treatments. Autosomal recessive hypophosphatemic... (Review)
Review
Awareness for hypophosphatemic rickets has increased in the last years, based on the availability of specific medical treatments. Autosomal recessive hypophosphatemic rickets type 2 (ARHR2) is a rare form of hypophosphatemic rickets, which is known to develop in survivors of generalized arterial calcification of infancy (GACI). Both disorders are based on a deficiency of ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) and present with a high clinical variability and a lack of a phenotype-genotype association. ARHR2 is characterized by phosphate wasting due to elevated fibroblast growth factor 23 (FGF23) levels and might represent a response of the organism to minimize ectopic calcification in individuals with ENPP1-deficiency. This report reviews the recent clinical and preclinical data on this ultra-rare disease in childhood.
Topics: Familial Hypophosphatemic Rickets; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Humans; Phosphates; Phosphoric Diester Hydrolases; Pyrophosphatases; Rickets, Hypophosphatemic
PubMed: 34252603
DOI: 10.1016/j.bone.2021.116111 -
Cell Cycle (Georgetown, Tex.) Jul 2020Hepatocellular carcinoma (HCC) has a poor prognosis, owing to its high potential for growth and metastasis. In this study, we aimed to investigate the roles of in human...
Hepatocellular carcinoma (HCC) has a poor prognosis, owing to its high potential for growth and metastasis. In this study, we aimed to investigate the roles of in human HCCcell growth and metastasis. We analyzed the expression level in human HCC tissues paired normal tissues in the Oncomine database, and assessed the relationship between the expression levels with HCC patient's overall survival and the prognostic value of in human HCC by Kaplan-Meier survival analysis. Real-time PCR and Western Blot were used to examine the expression levels of in normal liver cell line (LO2) and human HCC cell lines (SMCC-7721, HepG2, Huh7, MHCC-97 H, and LM3). Through lentivirus infection, we established human HCC stable cell lines (Huh7 and LM3) overexpressing . Then, we detected these cell viability, colony , and invasion. Subsequently, we performed the gene set enrichment analysis (GSEA) for the RNA-seq data of HCC patients from TCGA. Finally, we examined the expression level of several oncogenes, including CCNB1, PKM2, MMP7, and MMP9, in these cells via real-time PCR assay. Here, we found thatis significantly downregulated in the human HCC tissues paired normal tissues. Furthermore, the high expression level of is associated with better clinical outcomes in human HCC. Overexpression of inhibitscell growth and metastasis in human HCC cells, and expression levels negatively correlate with cell cycle and metastasis in HCC tissues. Moreover, the level of is negatively correlated with CCNB1, PKM2, MMP7, and MMP9 in human HCC cells and HCC tissues. These findings highlight a novel tumor suppressor in human HCC growth and metastasis, and provide a promising diagnostic and prognostic factor for humanHCC.
Topics: Carcinoma, Hepatocellular; Cell Cycle; Cell Movement; Cell Proliferation; Cell Survival; Gene Expression Regulation, Neoplastic; Humans; Inorganic Pyrophosphatase; Liver Neoplasms; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasm Proteins; Treatment Outcome; Tumor Stem Cell Assay
PubMed: 32578511
DOI: 10.1080/15384101.2020.1783472 -
Molecular Plant Pathology Mar 2021Plant viruses typically have highly condensed genomes, yet the plant-pathogenic viruses Cassava brown streak virus, Ugandan cassava brown streak virus, and Euphorbia... (Review)
Review
Plant viruses typically have highly condensed genomes, yet the plant-pathogenic viruses Cassava brown streak virus, Ugandan cassava brown streak virus, and Euphorbia ringspot virus are unusual in encoding an enzyme not yet found in any other virus, the "house-cleaning" enzyme inosine triphosphatase. Inosine triphosphatases (ITPases) are highly conserved enzymes that occur in all kingdoms of life and perform a house-cleaning function by hydrolysing the noncanonical nucleotide inosine triphosphate to inosine monophosphate. The ITPases encoded by cassava brown streak virus and Ugandan cassava brown streak virus have been characterized biochemically and are shown to have typical ITPase activity. However, their biological role in virus infection has yet to be elucidated. Here we review what is known of viral-encoded ITPases and speculate on potential roles in infection with the aim of generating a greater understanding of cassava brown streak viruses, a group of the world's most devastating viruses.
Topics: Manihot; Plant Diseases; Potyviridae; Pyrophosphatases; Viral Proteins; Inosine Triphosphatase
PubMed: 33471956
DOI: 10.1111/mpp.13021 -
Pediatrics International : Official... Jul 2021
Topics: Asian People; Humans; Mercaptopurine; Pyrophosphatases
PubMed: 34219339
DOI: 10.1111/ped.14558 -
Spectrochimica Acta. Part A, Molecular... Jan 2023A highly sensitive and selective sensor for the quantitative assay of inorganic pyrophosphatase (PPase) activity was developed based on a fluorescence "turn-off"...
A highly sensitive and selective sensor for the quantitative assay of inorganic pyrophosphatase (PPase) activity was developed based on a fluorescence "turn-off" strategy. Carbon quantum dots@Cu(II)-based metal-organic framework nanotubes (CQDs@Cu-MOF) with length less than 300 nm and width less than 20 nm were synthesized. CQDs in the nanotubes exhibited weak fluorescence owing to static quenching. The coordination reaction between pyrophosphate ion (PPi) and Cu(II) decomposed CQDs@Cu-MOF and led to the release of CQDs, of which the fluorescence recovered. In the presence of PPase, the hydrolysis of PPi generated phosphate ion (Pi). CQDs@Cu-MOF remained their structural stability and the fluorescence turned off. The fluorescence intensity difference of the mixture of CQDs@Cu-MOF and PPi in the absence and presence of PPase (-ΔF) was proportional to the PPase concentration from 0.1 to 5 mU mL and that from 5 to 50 mU mL, and a limit of detection at 0.03 mU mL was obtained. PPase activity in human serum was analyzed using the proposed fluorescence sensor and the recovery values were found to vary from 95.0% to 104 %.
Topics: Carbon; Diphosphates; Fluorescence; Humans; Inorganic Pyrophosphatase; Metal-Organic Frameworks; Nanotubes, Carbon; Pyrophosphatases; Quantum Dots
PubMed: 36027790
DOI: 10.1016/j.saa.2022.121771 -
Plant Biology (Stuttgart, Germany) Nov 2019Cellular pyrophosphate (PPi) homeostasis is vital for normal plant growth and development. Plant proton-pumping pyrophosphatases (H -PPases) are enzymes with different... (Review)
Review
Cellular pyrophosphate (PPi) homeostasis is vital for normal plant growth and development. Plant proton-pumping pyrophosphatases (H -PPases) are enzymes with different tissue-specific functions related to the regulation of PPi homeostasis. Enhanced expression of plant H -PPases increases biomass and yield in different crop species. Here, we emphasise emerging studies utilising heterologous expression in yeast and plant vacuole electrophysiology approaches, as well as phylogenetic relationships and structural analysis, to showcase that the H -PPases possess a PPi synthesis function. We postulate this synthase activity contributes to modulating and promoting plant growth both in H -PPase-engineered crops and in wild-type plants. We propose a model where the PPi synthase activity of H -PPases maintains the PPi pool when cells adopt PPi-dependent glycolysis during high energy demands and/or low oxygen environments. We conclude by proposing experiments to further investigate the H -PPase-mediated PPi synthase role in plant growth.
Topics: Arabidopsis; Arabidopsis Proteins; Diphosphates; Inorganic Pyrophosphatase; Pyrophosphatases
PubMed: 31081197
DOI: 10.1111/plb.13007 -
ChemMedChem Nov 2021Inhibition of membrane-bound pyrophosphatase (mPPase) with small molecules offer a new approach in the fight against pathogenic protozoan parasites. mPPases are absent...
Inhibition of membrane-bound pyrophosphatase (mPPase) with small molecules offer a new approach in the fight against pathogenic protozoan parasites. mPPases are absent in humans, but essential for many protists as they couple pyrophosphate hydrolysis to the active transport of protons or sodium ions across acidocalcisomal membranes. So far, only few nonphosphorus inhibitors have been reported. Here, we explore the chemical space around previous hits using a combination of screening and synthetic medicinal chemistry, identifying compounds with low micromolar inhibitory activities in the Thermotoga maritima mPPase test system. We furthermore provide early structure-activity relationships around a new scaffold having a pyrazolo[1,5-a]pyrimidine core. The most promising pyrazolo[1,5-a]pyrimidine congener was further investigated and found to inhibit Plasmodium falciparum mPPase in membranes as well as the growth of P. falciparum in an ex vivo survival assay.
Topics: Dose-Response Relationship, Drug; Humans; Molecular Structure; Pyrazoles; Pyrimidines; Pyrophosphatases; Structure-Activity Relationship
PubMed: 34459148
DOI: 10.1002/cmdc.202100392