-
Digestive Diseases and Sciences Mar 2023The thiopurine medications are well established in the treatment of inflammatory bowel disease (IBD). There is significant variation in levels of toxic and therapeutic... (Observational Study)
Observational Study
BACKGROUND
The thiopurine medications are well established in the treatment of inflammatory bowel disease (IBD). There is significant variation in levels of toxic and therapeutic metabolites. Current data from small or short-term studies support therapeutic drug monitoring (TDM) in assessing azathioprine (AZA) and 6-mercaptopurine (6MP). TDM of thiopurines involves measurement and interpretation of metabolites 6-TGN and 6-MMPR.
AIMS
This study aimed to assess long-cterm outcomes of patients on thiopurines following therapeutic drug monitoring.
METHODS
A multicenter retrospective observational study of outcomes post thiopurine TDM was conducted. Demographics, disease characteristics, physician global assessment, IBD therapy at baseline TDM and again at 12 months were collected. Clinical outcomes were analyzed according to TDM result, and indication for TDM including proactive and other indications.
RESULTS
The study included 541 patients. Only 39% of patients had appropriate dosing of thiopurines. AZA/6MP TDM informed a management change in 61.9%, and enabled 88.8% of the cohort to continue AZA/6MP following TDM. At 12 months following TDM the majority (74.1%) of the cohort remained on AZA/6MP. Clinical remission was higher at 12-months following thiopurines TDM (68%) compared to baseline (37%), including proactive TDM. Post TDM, 13.0% of patients were identified as shunters and commenced on thiopurine-allopurinol co-therapy.
CONCLUSION
Thiopurine TDM resulted in a change in management for the majority of patients. Post TDM significantly more patients were in remission. TDM allowed the identification of non-adherence and shunters who, without intervention, would not reach therapeutic drug levels. Proactive TDM allowed identification and management of inappropriate dosing, and was associated with increased levels of clinical remission.
Topics: Humans; Azathioprine; Mercaptopurine; Inflammatory Bowel Diseases; Retrospective Studies; Methylthioinosine; Immunosuppressive Agents
PubMed: 35687221
DOI: 10.1007/s10620-022-07556-y -
Cell Reports Apr 2022The innate immune recognition of the malaria-causing pathogen Plasmodium falciparum (P. falciparum) is not fully explored. Here, we identify the nucleoside...
The innate immune recognition of the malaria-causing pathogen Plasmodium falciparum (P. falciparum) is not fully explored. Here, we identify the nucleoside 5'-methylthioinosine (MTI), a Plasmodium-specific intermediate of the purine salvage pathway, as a pathogen-derived Toll-like receptor 8 (TLR8) agonist. Co-incubation of MTI with the TLR8 enhancer poly(dT) as well as synthetic or P. falciparum-derived RNA strongly increase its stimulatory activity. Of note, MTI generated from methylthioadenosine (MTA) by P. falciparum lysates activates TLR8 when MTI metabolism is inhibited by immucillin targeting the purine nucleoside phosphorylase (PfPNP). Importantly, P. falciparum-infected red blood cells incubated with MTI or cultivated with MTA and immucillin lead to TLR8-dependent interleukin-6 (IL-6) production in human monocytes. Our data demonstrate that the nucleoside MTI is a natural human TLR8 ligand with possible in vivo relevance for innate sensing of P. falciparum.
Topics: Humans; Malaria, Falciparum; Methylthioinosine; Nucleosides; Plasmodium falciparum; Purine-Nucleoside Phosphorylase; Purines; Toll-Like Receptor 8
PubMed: 35417716
DOI: 10.1016/j.celrep.2022.110691 -
Chemistry & Biodiversity Apr 2022In our continuous screening for bioactive microbial natural products, the culture extracts of a terrestrial Actinomycetes sp. GSCW-51 yielded two new metabolites,...
In our continuous screening for bioactive microbial natural products, the culture extracts of a terrestrial Actinomycetes sp. GSCW-51 yielded two new metabolites, i. e., 5-hydroxymethyl-3-(1-hydroxy-6-methyl-7-oxooctyl)dihydrofuran-2(3H)-one (1), 5-hydroxymethyl-3-(1,7-dihydroxy-6-methyloctyl)dihydrofuran-2(3H)-one (2), and two known compounds; 5'-methylthioinosine (3), and 5'-methylthioinosine sulfoxide (4), which are isolated first time from any natural source, along with four known compounds (5-8). The structures of the new compounds were deduced by HR-ESI-MS, 1D and 2D NMR data, and in comparison with related compounds from the literature. Additionally, owing to the current COVID-19 pandemic situation, we also computationally explored the therapeutic potential of our isolated compounds against SARS-CoV-2. Compound 4 showed the best binding energies of -6.2 and -6.6 kcal/mol for M and spike proteins, respectively. The intermolecular interactions were also studied using 2-D and 3-D imagery, which also supported the binding energies as well as put several insights under the spotlight. Furthermore, Lipinski's rule of 5 was used to predict the drug likeness of compounds 1-4, which indicated all compounds obey Lipinski's rule of 5. The study of bioavailability radars of the compounds 1-4 also confirmed their drug likeness properties where all the five crucial drug likeness parameters are in color area, which is safe to be used as drugs. Our isolation and computational findings highly encourage the scientific community to do further in vitro and in vivo studies of compounds 1-4.
Topics: Actinomyces; Humans; Molecular Docking Simulation; Molecular Dynamics Simulation; Pandemics; SARS-CoV-2; Thioinosine; COVID-19 Drug Treatment
PubMed: 35213767
DOI: 10.1002/cbdv.202100843 -
Viruses Dec 2021Broad-spectrum antiviral therapies hold promise as a first-line defense against emerging viruses by blunting illness severity and spread until vaccines and...
Broad-spectrum antiviral therapies hold promise as a first-line defense against emerging viruses by blunting illness severity and spread until vaccines and virus-specific antivirals are developed. The nucleobase favipiravir, often discussed as a broad-spectrum inhibitor, was not effective in recent clinical trials involving patients infected with Ebola virus or SARS-CoV-2. A drawback of favipiravir use is its rapid clearance before conversion to its active nucleoside-5'-triphosphate form. In this work, we report a synergistic reduction of flavivirus (dengue, Zika), orthomyxovirus (influenza A), and coronavirus (HCoV-OC43 and SARS-CoV-2) replication when the nucleobases favipiravir or T-1105 were combined with the antimetabolite 6-methylmercaptopurine riboside (6MMPr). The 6MMPr/T-1105 combination increased the C-U and G-A mutation frequency compared to treatment with T-1105 or 6MMPr alone. A further analysis revealed that the 6MMPr/T-1105 co-treatment reduced cellular purine nucleotide triphosphate synthesis and increased conversion of the antiviral nucleobase to its nucleoside-5'-monophosphate, -diphosphate, and -triphosphate forms. The 6MMPr co-treatment specifically increased production of the active antiviral form of the nucleobases (but not corresponding nucleosides) while also reducing levels of competing cellular NTPs to produce the synergistic effect. This in-depth work establishes a foundation for development of small molecules as possible co-treatments with nucleobases like favipiravir in response to emerging RNA virus infections.
Topics: Adenosine Triphosphate; Amides; Animals; Antimetabolites; Antiviral Agents; Cell Line; Drug Synergism; Guanosine Triphosphate; Humans; Methylthioinosine; Mutation; Phosphoribosyl Pyrophosphate; Pyrazines; RNA Viruses; RNA, Viral; Virus Replication
PubMed: 34960780
DOI: 10.3390/v13122508 -
Biomedicine & Pharmacotherapy =... Dec 2018Colon cancer is one of the most common digestive malignant tumors that leads to high mortality worldwide, and metastasis is the primary cause of cancer-related death. It...
Colon cancer is one of the most common digestive malignant tumors that leads to high mortality worldwide, and metastasis is the primary cause of cancer-related death. It is well accepted that the epithelial-mesenchymal transition (EMT) plays a key role in the process of metastasis. As a cytokine that macrophage secretes, IL-6 is involved in the progression of tumors, including the invasion and metastasis via kinds of signaling pathways. However, the mechanism of interactions between IL-6, macrophage, EMT and colon cancer is not fully understood. Increased CD68 macrophages and IL-6 level were found in colon tumor as compared to normal colon tissue. Metastatic lymph node showed even more CD68 macrophages and higher IL-6 level than the primary tumor. These results suggested that macrophages and IL-6 play an important role in EMT of colon cancer. In order to investigate the effect of macrophage and IL-6 on EMT of colon cancer, we cultured human colon carcinoma cell line SW48 with conditioned medium (CM) from PMA-stimulated monocyte THP-1 cells and tested for IL-6 dependent EMT pathways. Wound healing assay and Transwell assay were used to analyze cell migration and invasion. Results showed that CM-treated SW48 cells increased IL-6 production and displayed elevated capacity of migration and invasion compared to untreated cells. Increased expressions of EMT markers (N-cadherin, Vimentin and β-catenin) and decreased expression of EMT marker(E-cadherin) were found in CM-treated SW48 cells by Western Blot. The addition of an anti-IL-6 antibody significantly inhibited the increase of EMT markers (Vimentin and β-catenin) as well as cell migration and invasion, suggesting that IL-6 played a critical role in promoting EMT of CM-treated SW48 cells. In addition, we found that the levels of p-STAT3 and p-ERK increased in CM-treated SW48 compared to untreated cells, which can be reversed by AG490, an inhibitor of JAK. In the meantime, the suppression of JAK-associated signaling pathways caused a decrease of β-catenin. In summary, our study suggested that macrophage-induced IL-6 promotes migration and invasion of colon cancer cell via Wnt/β-catenin pathway in STAT3/ERK-dependent way.
Topics: 6-Aminonicotinamide; Antineoplastic Combined Chemotherapy Protocols; Aspartic Acid; Cell Line, Tumor; Cell Movement; Colonic Neoplasms; Epithelial-Mesenchymal Transition; Humans; Interleukin-6; MAP Kinase Signaling System; Macrophages; Methylthioinosine; STAT3 Transcription Factor; THP-1 Cells; Wnt Signaling Pathway; beta Catenin
PubMed: 30243096
DOI: 10.1016/j.biopha.2018.09.067 -
Microbiology (Reading, England) Jul 2018The methionine salvage pathway (MSP) is critical for regeneration of S-adenosyl-l-methionine (SAM), a widely used cofactor involved in many essential metabolic...
The methionine salvage pathway (MSP) is critical for regeneration of S-adenosyl-l-methionine (SAM), a widely used cofactor involved in many essential metabolic reactions. The MSP has been completely elucidated in aerobic organisms, and found to rely on molecular oxygen. Since anaerobic organisms do not use O2, an alternative pathway(s) must be operating. We sought to evaluate whether the functions of two annotated MSP enzymes from Methanocaldococcus jannaschii, a methylthioinosine phosphorylase (MTIP) and a methylthioribose 1-phosphate isomerase (MTRI), are consistent with functioning in a modified anaerobic MSP (AnMSP). We show here that recombinant MTIP is active with six different purine nucleosides, consistent with its function as a general purine nucleoside phosphorylase for both AnMSP and purine salvage. Recombinant MTRI is active with both 5-methylthioribose 1-phosphate and 5-deoxyribose 1-phosphate as substrates, which are generated from phosphororolysis of 5'-methylthioinosine and 5'-deoxyinosine by MTIP, respectively. Together, these data suggest that MTIP and MTRI may function in a novel pathway for recycling the 5'-deoxyadenosine moiety of SAM in M. jannaschii. These enzymes may also enable biosynthesis of 6-deoxy-5-ketofructose 1-phosphate (DKFP), an essential intermediate in aromatic amino acid biosynthesis. Finally, we utilized a homocysteine auxotrophic strain of Methanosarcina acetivorans Δma1821-22Δoahs (HcyAux) to identify potential AnMSP intermediates in vivo. Growth recovery experiments of the M. acetivorans HcyAux were performed with known and proposed intermediates for the AnMSP. Only one metabolite, 2-keto-(4-methylthio)butyric acid, rescued growth of M. acetivorans HcyAux in the absence of homocysteine. This observation may indicate that AnMSP pathways substantially differ among methanogens from phylogenetically divergent genera.
Topics: Bacterial Proteins; Biosynthetic Pathways; Deoxyadenosines; Fructosephosphates; Gene Expression; Genetic Complementation Test; Kinetics; Methanocaldococcus; Methanosarcina; Methionine; Molecular Weight; Recombinant Proteins; S-Adenosylmethionine; Species Specificity; Substrate Specificity
PubMed: 29877790
DOI: 10.1099/mic.0.000670 -
Chemico-biological Interactions Sep 2017To apply an innovative LC-MS/MS method to quantify thiopurine metabolites in human hepatocytes and to associate them to cytotoxicity.
AIM
To apply an innovative LC-MS/MS method to quantify thiopurine metabolites in human hepatocytes and to associate them to cytotoxicity.
METHODS
Immortalized human hepatocytes (IHH cells) were treated for 48 and 96 h, with 1.4 × 10 M azathioprine and 1.1 × 10 M mercaptopurine, concentrations corresponding to the IC values calculated after 96 h exposure in previous cytotoxicity analysis. After treatments, cells were collected for LC-MS/MS analysis to quantify 11 thiopurine metabolites with different level of phosphorylation and viable cells were counted by trypan blue exclusion assay to determine thiopurines in vitro effect on cell growth and survival. Statistical significance was determined by analysis of variance (ANOVA).
RESULTS
Azathioprine and mercaptopurine had a significant time-dependent cytotoxic effect (p-value ANOVA = 0.012), with a viable cell count compared to controls of 55.5% and 67.5% respectively after 48 h and 23.7% and 36.1% after 96 h; no significant difference could be observed between the two drugs. Quantification of thiopurine metabolites evidenced that the most abundant metabolite was TIMP, representing 57.1% and 40.3% of total metabolites after 48 and 96 h. Total thiopurine metabolites absolute concentrations decreased over time: total mean content decreased from 469.9 pmol/million cells to 83.6 pmol/million cells (p-value ANOVA = 0.0070). However, considering the relative amount of thiopurine metabolites, TGMP content significantly increased from 11.4% cells to 26.4% (p-value ANOVA = 0.017). A significant association between thiopurine effects and viable cell counts could be detected only for MeTIMP: lower MeTIMP concentrations were associated with lower cell survival (p-value ANOVA = 0.011). Moreover, the ratio between MeTIMP and TGMP metabolites directly correlated with cell survival (p-value ANOVA = 0.037).
CONCLUSION
Detailed quantification of thiopurine metabolites in a human hepatocytes model provided useful insights on the association between thioguanine and methyl-thioinosine nucleotides with cell viability.
Topics: Azathioprine; Cell Line; Cell Survival; Chromatography, High Pressure Liquid; Hepatocytes; Humans; Mercaptopurine; Purines; Tandem Mass Spectrometry
PubMed: 28811125
DOI: 10.1016/j.cbi.2017.08.009 -
Virology Journal Jun 2017Canine distemper (CD) is a widespread infectious disease that can severely impact a variety of species in the order Carnivora, as well as non-carnivore species such as...
BACKGROUND
Canine distemper (CD) is a widespread infectious disease that can severely impact a variety of species in the order Carnivora, as well as non-carnivore species such as non-human primates. Despite large-scale vaccination campaigns, several fatal outbreaks have been reported in wild and domestic carnivore populations. This, in association with expansion of the disease host range and the development of vaccine-escape strains, has contributed to an increased demand for therapeutic strategies synergizing with vaccine programs for effectively controlling canine distemper. 6-methylmercaptopurine riboside (6MMPr) is a modified thiopurine nucleoside with known antiviral properties against certain RNA viruses.
METHODS
We tested the inhibitory effects of 6MMPr against a wild-type CDV strain infection in cell culture. We measured infectious particle production and viral RNA levels in treated and untreated CDV-infected cells. Ribavirin (RIB) was used as a positive control.
RESULTS
Here, we report for the first time the antiviral effects of 6MMPr against canine distemper virus (CDV) in vitro. 6MMPr was able to reduce viral RNA levels and to inhibit the production of infectious CDV particles. The therapeutic selectivity of 6MMPr was approximately six times higher than that of ribavirin.
CONCLUSION
Our results indicate that 6MMPr has high anti-CDV potential and warrants further testing against other paramyxoviruses, as well as clinical testing of the compound against CDV.
Topics: Animals; Antiviral Agents; Cell Line; Distemper Virus, Canine; Dogs; Methylthioinosine; Microbial Viability
PubMed: 28651549
DOI: 10.1186/s12985-017-0785-6 -
Bioorganic & Medicinal Chemistry Sep 2015MTDIA is a picomolar transition state analogue inhibitor of human methylthioadenosine phosphorylase and a femtomolar inhibitor of Escherichia coli methylthioadenosine...
MTDIA is a picomolar transition state analogue inhibitor of human methylthioadenosine phosphorylase and a femtomolar inhibitor of Escherichia coli methylthioadenosine nucleosidase. MTDIA has proven to be a non-toxic, orally available pre-clinical drug candidate with remarkable anti-tumour activity against a variety of human cancers in mouse xenografts. The structurally similar compound MTDIH is a potent inhibitor of human and malarial purine nucleoside phosphorylase (PNP) as well as the newly discovered enzyme, methylthioinosine phosphorylase, isolated from Pseudomonas aeruginosa. Since the enantiomers of some pharmaceuticals have revealed surprising biological activities, the enantiomers of MTDIH and MTDIA, compounds 1 and 2, respectively, were prepared and their enzyme binding properties studied. Despite binding less tightly to their target enzymes than their enantiomers compounds 1 and 2 are nanomolar inhibitors.
Topics: Adenine; Drug Discovery; Escherichia coli; Humans; Models, Molecular; Neoplasms; Plasmodium falciparum; Protein Binding; Pseudomonas aeruginosa; Purine-Nucleoside Phosphorylase; Pyrrolidines; Stereoisomerism
PubMed: 26260335
DOI: 10.1016/j.bmc.2015.07.059 -
Journal of Crohn's & Colitis Dec 2014The thiopurines are widely used in the treatment of inflammatory bowel disease, but are limited by poor dose-effect relationship. The objective was to assess the ability...
BACKGROUND AND AIMS
The thiopurines are widely used in the treatment of inflammatory bowel disease, but are limited by poor dose-effect relationship. The objective was to assess the ability of a novel assay, determining the mono-, di-, and triphosphates, of thioguanine as well as methylthioinosine as individual metabolites in erythrocytes, to predict clinical outcome compared to a routine assay, determining metabolites as sums.
METHODS
Samples from 79 patients with Crohn's disease or ulcerative colitis treated with azathioprine or mercaptopurine were analysed by both assays. Clinical status was determined by the Harvey-Bradshaw and Walmsley indices. The genotypes of thiopurine methyltransferase (TPMT) and inosine triphosphatase were determined.
RESULTS
TPMT wild-type patients with thioguanine nucleotide (TGN) levels below the cut-off level were more likely to have active disease when TGN was measured by the novel assay (p=0.02), and when thioguanosine triphosphate (TGTP) was measured separately (p=0.01). When TGN was measured by the routine assay the correlation was not evident (p=0.12). Neither TGN levels nor TGTP correlated to disease activity in TPMT deficient patients. Patients with methyl thioinosine nucleotide (meTIN) levels above 1500 pmol/8×10^8 RBCs were more likely to have active disease (p=0.07). We observed good correlations between the mono-, di-, and triphosphates and their respective sums (R(2)>0.88).
CONCLUSIONS
The novel TGN assay was better in predicting clinical outcome compared to the routine assay, while determination of TGTP had no clinical advantage and TGTP ratio was not correlated to disease activity.
Topics: Adolescent; Adult; Aged; Azathioprine; Cross-Sectional Studies; Drug Monitoring; Erythrocytes; Female; GTP Phosphohydrolases; Guanine Nucleotides; Humans; Immunosuppressive Agents; Inflammatory Bowel Diseases; Male; Mercaptopurine; Methylthioinosine; Middle Aged; Thioguanine; Thioinosine; Thionucleotides; Young Adult
PubMed: 25239576
DOI: 10.1016/j.crohns.2014.08.009