Enzyme-free fluorescent DNA detection based on nucleic acid-templated click reaction via controllable synthesis of Cu2O as heterogeneous nanocatalyst.

In the field of nucleic acid amplification assays, developing enzyme-free, easy-to-use, and highly sensitive amplification approaches remains a challenge. In this work, we synthesized a heterogeneous Cu2O nanocatalyst (hnCu2O) with different particle sizes and shapes, which was used for developing enzyme- and label-free nucleic acid amplification methods based on the nucleic acid-templated azide-alkyne cycloaddition (AAC) reaction catalyzed by hnCu2O. The hnCu2O exhibited size- and shape-dependent catalytic activity, with smaller sizes and spherical-like shapes exhibiting superior activity. Spherical-like hnCu2O (61 ± 8 nm) not only achieved a ligation yield of up to 84.2 ± 3.9 % in 3 min but also exhibited faster kinetics in the nucleic acid-templated hnCu2O-catalyzed AAC reaction, with a high reaction rate of 0.65 min-1 and a half-life of 1.07 ± 0.09 min. Based on this result, we developed nucleic acid-templated click ligation linear amplification reaction (NA-CLLAR) and nucleic acid-templated click ligation exponential amplification reaction (NA-CLEAR) approach. By combining the recognition (complementary to the target sequence) and signal output (split G-quadruplex sequence) elements into a DNA probe, the NA-CLLAR and NA-CLEAR fluorescence assays achieved highly specific detection of target nucleic acids, with a detection limit of 2.8 aM based on G-quadruplex-enhanced fluorescence. This work is a valuable reference and will inspire researchers to design enzyme-free nucleic acid signal amplification strategies by developing different types of Cu(I) catalysts with improved catalytic activity.

Effect of HDAC9 on the differentiation of chicken embryonic stem cells into male germ cells.

Histone deacetylase 9 (HDAC9) is a histone deacetylase (HDAC) subtype IIa protein that deacetylates histone 3 (H3), histone 4 (H4), and nonhistone proteins in vivo to alter chromosomal shape and regulate gene transcription. There have been few studies on the regulatory influence of the HDAC9 gene on the differentiation of chicken embryonic stem cells (cESCs) into male germ cells, and the significance of HDAC9 is still unknown. Therefore, we explored the specific role of HDAC9 during differentiation of the cESCs of Jilin Luhua chickens through inhibition or overexpression. In medium supplemented with 10-5 mol/L retinoic acid (RA), cESCs were stimulated to develop into germ cells. HDAC9 and germline marker gene mRNA and protein levels were measured using qRT‒PCR and western blotting. During the differentiation of cESCs into male germ cells, overexpression of the HDAC9 gene greatly increased the mRNA and protein expression levels of the germline marker genes Stra8, Dazl, c-kit, and integrin ɑ6. The HDAC9 inhibitor TMP195 significantly decreased the mRNA and protein expression levels of the above markers. In summary, HDAC9 positively regulates the differentiation of cESCs.

Acacetin targets STING to alleviate the destabilization of the medial meniscus-induced osteoarthritis in mice.

Osteoarthritis (OA) is a common joint disorder affecting about 7% of the global population, primarily characterized by the gradual loss of articular cartilage. This degeneration results from local inflammation, matrix depletion, and direct cartilage damage. A critical element in this process is the activation of the stimulator of the interferon genes (STING) pathway. Emerging evidence highlights its potential as a therapeutic target, with natural products showing promise as inhibitors. Our study centers on Acacetin, a basic unit of polyketides known for its anti-inflammatory properties. Prior research has highlighted its potential interaction with STING based on the structure. Thus, this study aimed to assess the effectiveness of Acacetin as a STING inhibitor and its protective role against OA. In vitro experiments showed that Acacetin pretreatment not only mitigated interleukin-1ß (IL-1ß)-induced cytotoxicity but also decreased the inflammatory response and degeneration in chondrocytes stimulated IL-1ß. In vivo studies revealed that Acacetin administration significantly reduced articular cartilage destruction, abnormal bone remodeling, and osteophyte formation in a model of OA induced by destabilization of the medial meniscus (DMM). Mechanistically, Acacetin was found to interact directly with STING, and inhibit IL-1ß-induced activation of STING, along with the subsequent phosphorylation of the TBK1/NF-κB pathway in chondrocytes. In conclusion, our findings establish Acacetin as an effective inhibitor of STING that protects chondrocytes from IL-1ß-induced damage and slows the progression of OA in mice.

DNA-Templated Click Ligation Chain Reaction Catalyzed by Heterogeneous Cu2O for Enzyme-Free Amplification and Ultrasensitive Detection of Nucleic Acids.

Nucleic acids play a pivotal role in the diagnosis of diseases. However, rapid, cost-efficient, and ultrasensitive identification of nucleic acid targets still represents a significant challenge. Herein, we describe an enzyme-free DNA amplification method capable of achieving accurate and ultrasensitive nucleic acid detection via DNA-templated click ligation chain reaction (DT-CLCR) catalyzed by a heterogeneous nanocatalyst made of Cu2O (hnCu2O). This hnCu2O-DT-CLCR method is built on two cross-amplifying hnCu2O-catalyzed DNA-templated azide-alkyne cycloaddition-driven DNA ligation reactions that boast a fast reaction rate and a high DNA ligation yield in minutes, enabling rapid exponential amplification of specific DNA targets. This newly developed hnCu2O-DT-CLCR-enabled DNA amplification strategy is further integrated with two signal reporting mechanisms to achieve low-cost and easy-to-use biosensors: an electrochemical sensor through the conjugation of a methylene blue redox reporter to a DNA probe used in hnCu2O-DT-CLCR and a colorimetric sensor through the incorporation of the split-to-intact G-quadruplex DNAzyme encoded into hnCu2O-DT-CLCR. Both sensors are able to achieve specific detection of the intended DNA target with a limit of detection at aM ranges, even when challenged in complex biological matrices. The combined hnCu2O-DT-CLCR and sensing strategies offer attractive universal platforms for enzyme-free and yet efficient detection of specific nucleic acid targets.

Targeting EFHD2 inhibits interferon-γ signaling and ameliorates non-alcoholic steatohepatitis.

BACKGROUND & AIMS: The precise pathomechanisms underlying the development of non-alcoholic steatohepatitis (NASH, also known as metabolic dysfunction-associated steatohepatitis [MASH]) remain incompletely understood. In this study, we investigated the potential role of EF-hand domain family member D2 (EFHD2), a novel molecule specific to immune cells, in the pathogenesis of NASH. METHODS: Hepatic EFHD2 expression was characterized in patients with NASH and two diet-induced NASH mouse models. Single-cell RNA sequencing (scRNA-seq) and double-immunohistochemistry were employed to explore EFHD2 expression patterns in NASH livers. The effects of global and myeloid-specific EFHD2 deletion on NASH and NASH-related hepatocellular carcinoma were assessed. Molecular mechanisms underlying EFHD2 function were investigated, while chemical and genetic investigations were performed to assess its potential as a therapeutic target. RESULTS: EFHD2 expression was significantly elevated in hepatic macrophages/monocytes in both patients with NASH and mice. Deletion of EFHD2, either globally or specifically in myeloid cells, improved hepatic steatosis, reduced immune cell infiltration, inhibited lipid peroxidation-induced ferroptosis, and attenuated fibrosis in NASH. Additionally, it hindered the development of NASH-related hepatocellular carcinoma. Specifically, deletion of myeloid EFHD2 prevented the replacement of TIM4+ resident Kupffer cells by infiltrated monocytes and reversed the decreases in patrolling monocytes and CD4+/CD8+ T cell ratio in NASH. Mechanistically, our investigation revealed that EFHD2 in myeloid cells interacts with cytosolic YWHAZ (14-3-3ζ), facilitating the translocation of IFNγR2 (interferon-γ receptor-2) onto the plasma membrane. This interaction mediates interferon-γ signaling, which triggers immune and inflammatory responses in macrophages during NASH. Finally, a novel stapled α-helical peptide targeting EFHD2 was shown to be effective in protecting against NASH pathology in mice. CONCLUSION: Our study reveals a pivotal immunomodulatory and inflammatory role of EFHD2 in NASH, underscoring EFHD2 as a promising druggable target for NASH treatment. IMPACT AND IMPLICATIONS: Non-alcoholic steatohepatitis (NASH) represents an advanced stage of non-alcoholic fatty liver disease (NAFLD); however, not all patients with NAFLD progress to NASH. A key challenge is identifying the factors that trigger inflammation, which propels the transition from simple fatty liver to NASH. Our research pinpointed EFHD2 as a pivotal driver of NASH, orchestrating the over-activation of interferon-γ signaling within the liver during NASH progression. A stapled peptide designed to target EFHD2 exhibited therapeutic promise in NASH mice. These findings support the potential of EFHD2 as a therapeutic target in NASH.

Multiplexed electrochemical nucleic acid sensor based on visible light-mediated metal-free thiol-yne click reaction for simultaneous detection of different nucleic acid targets.

Simultaneous detection of multiple tumor biomarkers with a simple and low-cost assay is crucial for early cancer detection and diagnosis. Herein, we presented a low-cost and simple assay for multiplexed detection of tumor biomarkers using a spatially separated electrodes strategy. The sensor is fabricated based on a metal-free thiol-yne click reaction, which is mediated by visible light, on commercially available indium tin oxide (ITO) electrodes. Four biomarkers, including p53 DNA, Brca2 DNA, K-ras DNA, and MicroRNA-204 RNA, were used as model analytes, and the corresponding oligonucleotide probes were modified on the desired electrode units sequentially with 530 nm irradiation light in the presence of photosensitizer Eosin Y. By this visible light-mediated coupling reaction, oligonucleotide probe densities of up to 9.2 ± 0.7 × 1010 molecules/cm2 were readily obtained on the ITO electrode surface. The proposed multiplexed E-NA sensor could detect four different nucleic acid targets concurrently without crosstalk among adjacent electrodes and was also successfully applied for detecting targets in a 20% fetal calf serum sample. The detection limits for p53 DNA, Brca2 DNA, K-ras DNA, and MicroRNA-204 RNA were 0.72 nM, 0.97 nM, 2.15 nM, and 1.73 nM, respectively. The developed approach not only has a great potential for developing cost-effective biosensors on affordable substrates for nucleic acid target detection, but also be easily extended to detect other targets by modifying the specific oligonucleotide probes anchored on the electrode.

Glutathione-Responsive and Hydrogen Sulfide Self-Generating Nanocages Based on Self-Weaving Technology To Optimize Cancer Immunotherapy.

As an ideal drug carrier, it should possess high drug loading and encapsulation efficiency and precise drug targeting release. Herein, we utilized a template-guided self-weaving technology of phase-separated silk fibroin (SF) in reverse microemulsion (RME) to fabricate a kind of hyaluronic acid (HA) coated SF nanocage (HA-gNCs) for drug delivery of cancer immunotherapy. Due to the hollow structure, HA-gNCs were capable of simultaneous encapsulation of the anti-inflammatory drug betamethasone phosphate (BetP) and the immune checkpoint blockade (ICB) agent PD-L1 antibody (αPD-L1) efficiently. Another point worth noting was that the thiocarbonate cross-linkers used to strengthen the SF shell of HA-gNCs could be quickly broken by overexpressed glutathione (GSH) to reach responsive drug release inside tumor tissues accompanied by hydrogen sulfide (H2S) production in one step. The synergistic effect of released BetP and generated H2S guaranteed chronological modulation of the immunosuppressive tumor microenvironment (ITME) to amplify the therapeutic effect of αPD-L1 for the growth, metastasis, and recurrence of tumors. This study highlighted the exceptional prospect of HA-gNCs as a self-assistance platform for cancer drug delivery.

Single-atom Mo-tailored high-entropy-alloy ultrathin nanosheets with intrinsic tensile strain enhance electrocatalysis.

The precise structural integration of single-atom and high-entropy-alloy features for energy electrocatalysis is highly appealing for energy conversion, yet remains a grand challenge. Herein, we report a class of single-atom Mo-tailored PdPtNiCuZn high-entropy-alloy nanosheets with dilute Pt-Pt ensembles and intrinsic tensile strain (Mo1-PdPtNiCuZn) as efficient electrocatalysts for enhancing the methanol oxidation reaction catalysis. The as-made Mo1-PdPtNiCuZn delivers an extraordinary mass activity of 24.55 A mgPt-1 and 11.62 A mgPd+Pt-1, along with impressive long-term durability. The planted oxophilic Mo single atoms as promoters modify the electronic structure of isolated Pt sites in the high-entropy-alloy host, suppressing the formation of CO adsorbates and steering the reaction towards the formate pathway. Meanwhile, Mo promoters and tensile strain synergistically optimize the adsorption behaviour of intermediates to achieve a more energetically favourable pathway and minimize the methanol oxidation reaction barrier. This work advances the design of atomically precise catalytic sites by creating a new paradigm of single atom-tailored high-entropy alloys, opening an encouraging pathway to the design of CO-tolerance electrocatalysts.

Tuberculosis ineection might increase the risk f invasive candidiasis in an immmunocompetent patient / Tuberculose pode aumentar o risco de candidíase invasiva em paciente imunocompetente

Deep Candida infections commonly occur in immunosuppressed patients. A rare case of a multiple deep organ infection with Candida albicans and spinal tuberculosis was reported in a healthy young man. The 19-year-old man complained of month-long fever and lower back pain. He also had a history of scalded mouth syndrome. Coinfection with Mycobacterium tuberculosis and Candida albicans was diagnosed using the culture of aspirates from different regions. Symptoms improved considerably after antifungal and antituberculous therapy. This case illustrates that infection with tuberculosis might impair the host's immune system and increase the risk of invasive candidiasis in an immunocompetent patient.

As infecções profundas por Candida ocorrem geralmente em pacientes imunossuprimidos. Relatamos caso raro de infecções profundas em múltiplos órgãos por Candida albicans e neuro tuberculose em homem jovem saudável. Um jovem de 19 anos de idade queixou-se de febre e lombalgia há um mês. Relatava ainda histórico de síndrome da boca escaldada. Foi diagnosticada co-infecção por Mycobacterium tuberculosis e Candida albicans em cultura do aspirado de diferentes regiões do organismo. Os sintomas melhoraram significativamente após a terapia antifúngica e antituberculosa. Este caso é apresentado para mostrar que a tuberculose pode prejudicar o sistema imune do hospedeiro e aumentar o risco de candidíase invasiva em paciente imunocompetente.

Listeria monocytogenes meningitis in an immunocompetent adult: a case report / Listeria monocytogenes meningite em um adulto imunocompetente: relato de caso

Listeria monocytogenes (L. monocytogenes) is an uncommon cause of bacterial meningitis in immunocompetent adults. Patients with immunosuppression are at increased risk of developing serious invasive diseases, particularly meningitis. We describe a case of meningitis caused by L. monocytogenes in an immunocompetent and previously healthy 34-year-old adult. The patient received treatment with intravenous ampicillin plus amikacin and made a full recovery. L. monocytogenes should be suspected in immunocompetent adults with bacterial meningitis who fail to respond to empirical antibiotic treatment.

Listeria monocytogenes (L. monocytogenes) é uma causa rara de meningite bacteriana em adultos imunocompetentes. Pacientes com imunossupressão têm maior risco de desenvolver graves doenças invasivas, especialmente a meningite. Descrevemos um caso de meningite por L. monocytogenes em um adulto imunocompetente e previamente sadio com idade de 34 anos. O paciente recebeu tratamento com ampicilina intravenosa mais amicacina e fez uma recuperação completa. L. monocytogenes deve ser suspeitada em imunocompetentes adultos com meningite bacteriana que não respondem ao tratamento antibiótico empírico.