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Short oligonucleotides incorporating either 1‐mercuri‐6‐phenylcarbazole, 8‐mercuri‐6‐phenylcarbazole, or 1,8‐dimercuri‐6‐phenylcarbazole C‐nucleoside in the middle of the chain have been synthesized and studied for their potential as hybridization probes for sequences containing thiopyrimidine nucleobases. All of these oligonucleotides formed very stable duplexes with complementary sequences pairing the organometallic moiety with either 2‐ or 4‐thiothymine. The isomeric monomercurated oligonucleotides were also able to discriminate between 2‐ and 4‐thiothymine based on the different melting temperatures of the respective duplexes. DFT‐optimized structures of the most stable mononuclear HgII‐mediated base pairs featured a coordinated covalent bond between HgII and either S2 or S4 and a hydrogen bond between the carbazole nitrogen and N3. The dinuclear HgII‐mediated base pairs, in turn, were geometrically very similar to the one previously reported to form between 1,8‐dimercuri‐6‐phenylcarbazole and thymine and had one HgII ion coordinated to a thio and the other one to an oxo substituent. [ABSTRACT FROM AUTHOR]

Standard and targeted cancer therapies for late-stage cancer patients almost universally fail due to tumor heterogeneity/plasticity and intrinsic or acquired drug resistance. We used the telomerase substrate nucleoside precursor, 6-thio-2'-deoxyguanosine (6-thio-dG), to target telomerase-expressing non-small cell lung cancer cells resistant to EGFR-inhibitors and commonly used chemotherapy combinations. Colony formation assays, human xenografts as well as syngeneic and genetically engineered immune competent mouse models of lung cancer were used to test the effect of 6-thio-dG on targeted therapy- and chemotherapy-resistant lung cancer human cells and mouse models. We observed that erlotinib-, paclitaxel/carboplatin-, and gemcitabine/cisplatin-resistant cells were highly sensitive to 6-thio-dG in cell culture and in mouse models. 6-thio-dG, with a known mechanism of action, is a potential novel therapeutic approach to prolong disease control of therapy-resistant lung cancer patients with minimal toxicities.

Aim: To report a case of a female patient with hemophagocytic lymphohistiocytosis (HLH) and to systematically review the available cases of the association between HLH and inflammatory bowel disease (IBD). Methods: In accordance to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, retrieval of studies was based on Medical Subject Headings and Health Sciences Descriptors, which were combined using Boolean operators. Searches were run on the electronic databases Scopus, Web of Science, MEDLINE (PubMed), Biblioteca Regional de Medicina, Latin American and Caribbean Health Sciences Literature, Cochrane Library for Systematic Reviews and Opengrey.eu. Languages were restricted to English, Spanish and Portuguese. There was no date of publication restrictions. The reference lists of the studies retrieved were searched manually. Results: The search strategy retrieved 223 references. In the final analysis, 28 references were included, with the report of 35 cases. The most common clinical finding was fever, 57% of patients had a cytomegalovirus infection and 30 patients were on thiopurines previously to HLH diagnosis. Most patients were treated with steroids and antiviral therapy. All-cause mortality was 22%. Conclusion: These findings suggest that there might be a connection of HLH to IBD, opportunistic viral infections and the use of thiopurines. Due to the severity of such disease, the clinical suspicion is paramount to early diagnosis and therapy.

Auricularia cornea has garnered attention due to its nutrition, culinary applications, and promising commercial prospects. However, there is little information available regarding the metabolic profiling of various colors strains. In this study, 642 metabolites across 64 classes were identified by LC-MS/MS to understand the metabolic variations between white, pink and dark brown strains. Notably, prenol lipids, carboxylic acids and fatty acyls accounted for 46.8 % of the total. Comparative analysis revealed 17 shared differential metabolites (DMs) among them. ACP vs ACW exhibited 17 unique metabolites, including d-arginine and maleic acid, etc. ACP vs ACB showed 5 unique metabolites, with only PS(18:1(9Z)/0:0) demonstrating up-regulation. ACB vs ACW showed 8 unique metabolites, including 4-hydroxymandelic acid and 5'-methylthioadenosine, etc. KEGG enrichment analysis highlighted pathway variations, and MetPA analysis identified key-pathways influencing DMs accumulation in A. cornea. This pioneering metabolomics study offers insights into A. cornea metabolic profiling, potential applications, and guides further research., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The design of novel 4'-thionucleoside analogues bearing a C2' stereogenic all-carbon quaternary center is described. The synthesis involves a highly diastereoselective Mukaiyama aldol reaction, and a diastereoselective radical-based vinyl group transfer to generate the all-carbon stereogenic C2' center, along with different approaches to control the selectivity of the N -glycosidic bond. Intramolecular S N 2-like cyclization of a mixture of acyclic thioaminals provided analogues with a pyrimidine nucleobase. A kinetic bias favoring cyclization of the 1',2'- anti thioaminal furnished the desired β-D-4'-thionucleoside analogue in a 7:1 ratio. DFT calculations suggest that this kinetic resolution originates from additional steric clash in the S N 2-like transition state for 1',4'- trans isomers, causing a significant decrease in their reaction rate relative to 1',4'- cis counterparts. N -glycosylation of cyclic glycosyl donors with a purine nucleobase enabled the formation of novel 2-chloroadenine 4'-thionucleoside analogues. These proprietary molecules and other derivatives are currently being evaluated both in vitro and in vivo to establish their biological profiles.

All organisms utilize S -adenosyl-l-methionine (SAM) as a key co-substrate for the methylation of biological molecules, the synthesis of polyamines, and radical SAM reactions. When these processes occur, 5'-deoxy-nucleosides are formed as byproducts such as S -adenosyl-l-homocysteine, 5'-methylthioadenosine (MTA), and 5'-deoxyadenosine (5dAdo). A prevalent pathway found in bacteria for the metabolism of MTA and 5dAdo is the dihydroxyacetone phosphate (DHAP) shunt, which converts these compounds into dihydroxyacetone phosphate and 2-methylthioacetaldehyde or acetaldehyde, respectively. Previous work in other organisms has shown that the DHAP shunt can enable methionine synthesis from MTA or serve as an MTA and 5dAdo detoxification pathway. Rather, the DHAP shunt in Escherichia coli ATCC 25922, when introduced into E. coli K-12, enables the use of 5dAdo and MTA as a carbon source for growth. When MTA is the substrate, the sulfur component is not significantly recycled back to methionine but rather accumulates as 2-methylthioethanol, which is slowly oxidized non-enzymatically under aerobic conditions. The DHAP shunt in ATCC 25922 is active under oxic and anoxic conditions. Growth using 5-deoxy-d-ribose was observed during aerobic respiration and anaerobic respiration with Trimethylamine N-oxide (TMAO), but not during fermentation or respiration with nitrate. This suggests the DHAP shunt may only be relevant for extraintestinal pathogenic E. coli lineages with the DHAP shunt that inhabit oxic or TMAO-rich extraintestinal environments. This reveals a heretofore overlooked role of the DHAP shunt in carbon and energy metabolism from ubiquitous SAM utilization byproducts and suggests a similar role may occur in other pathogenic and non-pathogenic bacteria with the DHAP shunt., Importance: The acquisition and utilization of organic compounds that serve as growth substrates are essential for Escherichia coli to grow and multiply. Ubiquitous enzymatic reactions involving S-adenosyl-l-methionine as a co-substrate by all organisms result in the formation of the 5'-deoxy-nucleoside byproducts, 5'-methylthioadenosine and 5'-deoxyadenosine. All E. coli possess a conserved nucleosidase that cleaves these 5'-deoxy-nucleosides into 5-deoxy-pentose sugars for adenine salvage. The DHAP shunt pathway is found in some extraintestinal pathogenic E. coli , but its function in E. coli possessing it has remained unknown. This study reveals that the DHAP shunt enables the utilization of 5'-deoxy-nucleosides and 5-deoxy-pentose sugars as growth substrates in E. coli strains with the pathway during aerobic respiration and anaerobic respiration with TMAO, but not fermentative growth. This provides an insight into the diversity of sugar compounds accessible by E. coli with the DHAP shunt and suggests that the DHAP shunt is primarily relevant in oxic or TMAO-rich extraintestinal environments., Competing Interests: The authors declare no conflict of interest.

Detection of a pathogen is crucial prior to all prophylaxis and post exposure treatment, as it can prevent further disease manifestation. In this study, we have developed a nucleic acid pre-amplification based CRISPR diagnostic for detection and surveillance of Bacillus anthracis Sterne. Strand Invasion Based isothermal Amplification (SIBA) platform and Cas12a (CRISPR endo-nuclease) was used to develop CRISPR-SIBA, a multifaceted diagnostic platform. SIBA was employed as the isothermal pre-amplification platform. CRISPR-Cas12a based collateral trans-cleavage reaction was used to ensure and enhance the specificity of the system. Efficiency of the detection system was evaluated by detecting Bacillus anthracis Sterne in complex wastewater sample backgrounds. Previously reported, Prophage 3, Cya and Pag genes of Bacillus anthracis were used as targets for this assay. The amplification system provided reliable and specific detection readout, with a sensitivity limit of 100 colony forming units in 40 min. The endpoint fluorescence from CRISPR collateral cleavage reactions gave a detection limit of 10 5 to 10 6 CFUs. The experiments conducted in this study provide the evidence for SIBA's applicability and compatibility with CRISPR-Cas system and its efficiency to specifically detect Bacillus anthracis Sterne. CRISPR-SIBA can be translated into developing cost-effective diagnostics for pathogens in resource constrained settings., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Aim: While the United States is becoming increasingly Multiracial, much is still unknown about the behavioral health of these growing new generations of Multiracial Americans. To narrow this research gap, this study investigated the prevalence/frequency of substance use and major depressive episodes [MDE] among non-Hispanic Multiracial [NHM] adolescents compared to their non-Hispanic White [NHW] counterparts and whether racial differences vary by socioeconomic status., Methods: We analyzed data from the 2015-2019 National Survey on Drug Use and Health (N = 3,645 NHM and 34,776 NHW adolescents aged 12-17). Average Marginal Effects derived from logistic regression and negative binomial regression were used to examine (1) differences in six outcomes (past-month use of alcohol, cannabis, or drugs other than cannabis [DOTC], past-year MDE, and the frequency of alcohol and cannabis use among past-month users) by Multiracial status; (2) the moderation effect of family income on these associations., Results: Compared to high-income NHW adolescents, high-income NHM adolescents reported significantly higher prevalence of past-month cannabis and DOTC use, and past-year MDE. No racial differences were observed at other income levels. Furthermore, moderation analyses indicated that the effect of Multiracial status on MDE was larger in the highest income group compared to the lowest income group., Conclusion: Our findings suggested that NHM adolescents, particularly those from high income families, exhibit increased prevalence of drug use and depression than NHW adolescents. As the US becomes more diverse, there is a need to further examine the social and structural factors driving the identified racial differences., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Disruption of the immune system during embryonic brain development by environmental chemicals was proposed as a possible cause of neurodevelopmental disorders. We previously found adverse effects of di-n-octyltin dichloride (DOTC) on maternal and developing immune systems of rats in an extended one-generation reproductive toxicity study according to the OECD 443 test guideline. We hypothesize that the DOTC-induced changes in the immune system can affect neurodevelopment. Therefore, we used in-vivo MRI and PET imaging and genomics, in addition to behavioral testing and neuropathology as proposed in OECD test guideline 443, to investigate the effect of DOTC on structural and functional brain development. Male rats were exposed to DOTC (0, 3, 10, or 30 mg/kg of diet) from 2 weeks prior to mating of the F0-generation until sacrifice of F1-animals. The brains of rats, exposed to DOTC showed a transiently enlarged volume of specific brain regions (MRI), altered specific gravity, and transient hyper-metabolism ([ 18 F]FDG PET). The alterations in brain development concurred with hyper-responsiveness in auditory startle response and slight hyperactivity in young adult animals. Genomics identified altered transcription of key regulators involved in neurodevelopment and neural function (e.g. Nrgrn , Shank3 , Igf1r , Cck , Apba2 , Foxp2 ); and regulators involved in cell size, cell proliferation, and organ development, especially immune system development and functioning (e.g. LOC679869 , Itga11 , Arhgap5 , Cd47 , Dlg1 , Gas6 , Cml5 , Mef2c ). The results suggest the involvement of immunotoxicity in the impairment of the nervous system by DOTC and support the hypothesis of a close connection between the immune and nervous systems in brain development.

The role of the DMRT family in male sex determination and differentiation is significant, but its regulatory role in spotted knifejaw with Y fusion chromosomes remains unclear. Through genome-wide scanning, transcriptome analysis, qPCR, FISH, and RNA interference (RNAi), we investigated the DMRT family and the dmrt1-based sex regulation network. Seven DMRTs were identified (DMRT1/2 (2a,2b)/6, DMRT4/5, DMRT3), and dmrt gene dispersion among chromosomes is possibly driven by three whole-genome duplications. Transcriptome analysis enriched genes were associated with sex regulation and constructed a network associated with dmrt1. qPCR and FISH results showed the expression dimorphism of sex-related genes in dmrt-related regulatory networks. RNAi experiments indicated a distinct sex regulation mode in spotted knifejaw. Dmrt1 knockdown upregulated male-related genes (sox9a, sox9b, dmrt1, amh, amhr2) and hsd11b2 expression, which is critical for androgen synthesis. Amhr2 is located on the heterozygous chromosome (Y) and is specifically localized in primary spermatocytes, and is extremely upregulated after dmrt1 knockdown which suggested besides the important role of dmrt1 in male differentiation, the amhr2 along with amhr2/amh system, also play important regulatory roles in maintaining high expression of the hsd11b2 and male differentiation. This study aims to further investigate sex regulatory mechanisms in species with fusion chromosomes., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

There are few effective treatments for small cell lung cancer (SCLC) underscoring the need for innovative therapeutic approaches. This study focuses on exploiting telomerase, a critical SCLC dependency as a therapeutic target. A prominent characteristic of SCLC is their reliance on telomerase activity, a key enzyme essential for their continuous proliferation. Here we utilize a nucleoside analog, 6-Thio-2'-deoxyguanosine (6TdG) currently in phase II clinical trials, that is preferentially incorporated by telomerase into telomeres leading to telomere dysfunction. Using preclinical mouse and human derived models we find low intermittent doses of 6TdG inhibit tumor growth and reduce metastatic burden. Anti-tumor efficacy correlates with a reduction in a subpopulation of cancer initiating like cells (CICs) identified by their expression of L1CAM/CD133 and highest telomerase activity. 6TdG treatment also leads to activation of innate and adaptive anti-tumor responses. Mechanistically, 6TdG depletes CICs and induces type-I interferon signaling leading to tumor immune visibility by activating tumor cell STING signaling. We also observe increased sensitivity to irradiation after 6TdG treatment in both syngeneic and humanized SCLC xenograft models both of which are dependent on the presence of host immune cells. This study underscores the immune-enhancing and metastasis-reducing effects of 6TdG, employing a range of complementary in vitro and in vivo SCLC preclinical models providing a potential therapeutic approach to SCLC., (© 2024. The Author(s).)

Increasing evidence confirms that histone modification plays a critical role in preserving long-term immunological memory. Immune priming is a novel form of immunological memory recently verified in invertebrates. Toll-like receptor (TLR) signaling and cytokines have been reported to be involved in the immune priming of the Pacific oyster Crassostrea gigas . In the present study, the expression of Toll-like receptor 3 ( Cg TLR3), myeloid differentiation factor 88-2 ( Cg Myd88-2) and interleukin 17-1 ( Cg IL17-1) was found to be elevated in the hemocytes of C. gigas at 6 h after the secondary stimulation with Vibrio splendidus , which was significantly higher than that at 6 h after the primary stimulation ( p < 0.05). A significant increase in histone H3 lysine 4 trimethylation (H3K4me3) enrichment was detected in the promoter region of the Cg TLR3 gene at 7 d after the primary stimulation with inactivated V. splendidus ( p < 0.05). After the treatment with a histone methyltransferase inhibitor (5'-methylthioadenosine, MTA), the level of H3K4me3 at the promoter of the Cg TLR3 gene decreased significantly at 7 d after the primary stimulation with inactivated V. splendidus ( p < 0.05), and the expression of Cg TLR3, Cg MyD88-2 and Cg IL17-1 was significantly repressed at 6 h after the secondary stimulation with V. splendidus ( p < 0.05). Conversely, the treatment with monomethyl fumarate (MEF, an inhibitor of histone demethylases) resulted in a significant increase in H3K4me3 enrichment levels at the Cg TLR3 promoter at 7 d after the primary stimulation ( p < 0.05), and the expression of Cg TLR3, Cg MyD88-2 and Cg IL17-1 was observed to increase significantly at 6 h after the secondary stimulation ( p < 0.05). These results suggested that H3K4me3 regulated MyD88-dependent TLR signaling in the hemocytes of C. gigas , which defined the role of histone modifications in invertebrate immune priming.

Dietary patterns and corresponding gut microbiota profiles are associated with various health conditions. A diet rich in polyphenols, primarily plant-based, has been shown to promote the growth of probiotic bacteria in the gastrointestinal tract, subsequently reducing the risk of metabolic disorders in the host. The beneficial effects of these bacteria are largely due to the specific metabolites they produce, such as short-chain fatty acids and membrane proteins. In this study, we employed a metabolomics-guided bioactive metabolite identification platform that included bioactivity testing using in vitro and in vivo assays to discover a bioactive metabolite produced from probiotic bacteria. Through this approach, we identified 5'-methylthioadenosine (MTA) as a probiotic bacterial-derived metabolite with anti-obesity properties. Furthermore, our findings indicate that MTA administration has several regulatory impacts on liver functions, including modulating fatty acid synthesis and glucose metabolism. The present study elucidates the intricate interplay between dietary habits, gut microbiota, and their resultant metabolites.

Thiopurines have been widely used for the maintenance of remission or steroid sparing in patients with inflammatory bowel disease. However, potential drug-related adverse events frequently interfere with their use. Indeed, drug withdrawals associated with adverse reactions have been reported in approximately 25% of patients. To balance the efficacy, safety, and tolerability of thiopurines, regular monitoring of biomarkers (complete blood cell count, liver function test, and metabolic profiles), steady dose escalation, and pretreatment thiopurine S-methyltransferase (TPMT) genotype screening have been routinely recommended. However, the complex thiopurine metabolic pathway and individual differences attributed to pharmacogenetic diversity limit the effectiveness of these strategies in the optimization of thiopurine therapy. Recently, in an effort to facilitate more accurate and personalized prediction of thiopurine response or toxicity, novel genetic markers including NUDT15 and FTO genes were discovered. These discoveries are remarkable because TPMT screening has minimal efficacy for predicting myelosuppression especially in Asian populations, despite the fact that thee populations have a higher frequency of myelosuppression than Western populations. This review focuses on the current understanding of the metabolic pathway and the pharmacogenetics of thiopurines and suggests a personalized preventive strategy against potential adverse drug reactions to optimize their therapeutic application. [ABSTRACT FROM AUTHOR]

Starting from a commercially available thioether, we report a nine-step synthesis of a 4'-thiouridine phosphoramidite building-block. We install the uracil nucleobase using Pummerer-type glycosylation of a sulfoxide intermediate followed by a series of protecting group manipulations to deliver the desired phosphite. Notably, we introduce a 3',5'-O-di-tert-butylsilylene protecting group within a 4'-thiosugar framework, harnessing this to ensure regiospecific installation of the 2'-O-silyl protecting group. We envisage this methodology will be generally applicable to other 4'-thionucleosides and duly support the exploration of their inclusion within related nucleic acid syntheses. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: (2R,3S,4R)-2,3-O-Isopopropylidene-5-O-tert-butyldiphenylsilyl-1-(4-sulfinyl)cyclopentane: Sulfoxidation Basic Protocol 2: 2',3'-O-Isopropylidene-5'-O-tert-butyldiphenylsilyl-4'-thiouridine: Pummerer glycosylation Basic Protocol 3: 4'-Thiouridine: Deprotection Basic Protocol 4: 2'-O-tert-Butyldimethylsilyl-3',5'-di-tert-butylsiloxy-4'-thiouridine: 2',3',5'-O-silylation Basic Protocol 5: 2'-O-tert-Butyldimethylsilyl-4'-thiouridine: Selective 3'-5'-desilylation Basic Protocol 6: 2'-O-tert-Butyldimethylsilyl-5'-O-dimethoxytrityl-4'-thiouridine: 5'-O-dimethoxytritylation Basic Protocol 7: 2'-O-tert-butyldimethylsilyl-3'-O-[(2-cyanoethoxy)(N,N-diisopropylamino)phosphino]-5'-O-dimethoxytrityl-4'-thiouridine: 3'-O-phosphitylation., (© 2023 The Authors. Current Protocols published by Wiley Periodicals LLC.)

Cyclic diadenosine monophosphate (c-di-AMP) is a bacterial cyclic dinucleotide (CDN) comprising two adenosine monophosphates covalently linked by two 3',5'-phosphodiester bonds. c-di-AMP works as a second messenger, regulating many biological processes in bacteria such as cell wall homeostasis, DNA integrity, and sporulation via specific protein and/or RNA receptors. Moreover, c-di-AMP can function as an immunomodulatory agent in eukaryote cells via the stimulator of interferon genes (STING) signaling pathway. This protocol describes the chemical synthesis of two c-di-AMP analogs with a sulfur atom at the 4'-position of the furanose ring instead of an oxygen atom: c-di-4'-thioAMP (1) and cAMP-4'-thioAMP (2). Analogs 1 and 2 have resistance to phosphodiesterase-mediated degradation and are therefore useful for understanding the diverse biological phenomena regulated by c-di-AMP. In this protocol, two 4'-thioadenosine monomers are initially prepared via a Pummerer-like reaction assisted by hypervalent iodine. The CDN skeleton is then constructed through two key reactions based on phosphoramidite chemistry: dimerization of two appropriately protected nucleoside monomers to produce a linear dinucleotide, followed by macrocyclization of the resulting linear dinucleotide to form the CDN skeleton. © 2023 Wiley Periodicals LLC. Basic Protocol 1: Preparation of 4'-thioadenosine monomers 13 and 14 Basic Protocol 2: Preparation of c-di-4'-thioAMP (1) and cAMP-4'-thioAMP (2)., (© 2023 Wiley Periodicals LLC.)