Construction of an Enzymatically Controlled DNA Nanomachine for One-Step Imaging of Telomerase in Living Cells.

Telomerase is a basic reverse transcriptase that maintains the telomere length in cells, and accurate and specific sensing of telomerase in living cells is critical for medical diagnostics and disease therapeutics. Herein, we demonstrate for the first time the construction of an enzymatically controlled DNA nanomachine with endogenous apurinic/apyrimidinic endonuclease 1 (APE1) as a driving force for one-step imaging of telomerase in living cells. The DNA nanomachine is designed by rational engineering of substrate probes and reporter probes embedded with an enzyme-activatable site (i.e., AP site) and their subsequent assembly on a gold nanoparticle (AuNP). Upon recognition and cleavage of the AP site in the substrate probe by APE1, the loop of the substrate probe unfolds, exposing telomeric primer (TP) with the 3'-OH end. Subsequently, the TP is elongated by telomerase at the 3'-OH end to generate a long telomeric product. The resultant telomeric product acts as a swing arm that can hybridize with a reporter probe to initiate the APE1-powered walking reaction, ultimately generating a significantly enhanced fluorescence signal. Notably, endogenous APE1 is used as the driving force of the DNA nanomachine, avoiding the introduction of exogenous auxiliary cofactors into the cellular microenvironment. Owing to the high kinetics and high amplification efficiency of the APE1-powered DNA nanomachine, this strategy enables one-step sensitive sensing of telomerase in vitro and in vivo. It can successfully discriminate telomerase activity between cancer cells and normal cells, screen telomerase inhibitors, and monitor the variations of telomerase activity in living cells, offering a prospective platform for molecular diagnostics and drug discovery.

Radiomics in esophagogastric junction cancer: A scoping review of current status and advances.

PURPOSE: This scoping review aimed to understand the advances in radiomics in esophagogastric junction (EGJ) cancer and assess the current status of radiomics in EGJ cancer. METHODS: We conducted systematic searches of PubMed, Embase, and Web of Science databases from January 18, 2012, to January 15, 2023, to identify radiomics articles related to EGJ cancer. Two researchers independently screened the literature, extracted data, and assessed the quality of the studies using the Radiomics Quality Score (RQS) and the METhodological RadiomICs Score (METRICS) tool, respectively. RESULTS: A total of 120 articles were retrieved from the three databases, and after screening, only six papers met the inclusion criteria. These studies investigated the role of radiomics in differentiating adenocarcinoma from squamous carcinoma, diagnosing T-stage, evaluating HER2 overexpression, predicting response to neoadjuvant therapy, and prognosis in EGJ cancer. The median score percentage of RQS was 34.7% (range from 22.2% to 38.9%). The median score percentage of METRICS was 71.2% (range from 58.2% to 84.9%). CONCLUSION: Although there is a considerable difference between the RQS and METRICS scores of the included literature, we believe that the research value of radiomics in EGJ cancer has been revealed. In the future, while actively exploring more diagnostic, prognostic, and biological correlation studies in EGJ cancer, greater emphasis should be placed on the standardization and clinical application of radiomics.

Dual-energy CT Portal Venography: Clinical Application Values and Future Opportunities.

Standard multidetector computed tomography (MDCT) uses a single X-ray tube to emit a mixed energy X-ray beam, which is received by a single detector. The difference is that dual-energy CT (DECT), a new equipment in recent years, employs a single X-ray tube or two X-ray tubes to emit two single-energy X-ray beams, which are received by a single or two detectors. The application of dual-energy technology to portal venography has become one of the research hotspots. This paper will elaborate on the clinical application values of DECT portal venography in improving portal vein image quality, distinguishing the nature of portal vein thrombus, reducing contrast agent dose and radiation dose, and will discuss the possibility of its movement from research to routine practice and future development opportunities.

Olefin skeletal rearrangement enabling access to multiarylated N-sulfonyl amidines.

A base-promoted olefin skeletal rearrangement strategy from para-quinone methides (p-QMs) and N-fluoroarenesulfonamides is reported, enabling direct nitrogen insertion of olefins to produce a series of multiarylated (Z)-N-sulfonyl amidines with complete stereoselectivity and generally good yields. Using p-QMs without o-hydroxy substituents gave triarylated N-sulfonyl amidines, whereas tetraarylated N,N'-disulfonyl amidines were synthesized with the existence of o-hydroxy groups.

Cinnamaldehyde: An effective component of Cinnamomum cassia inhibiting Helicobacter pylori.

ETHNOPHARMACOLOGICAL RELEVANCE: Cinnamomum cassia Presl (Cinnamomum cassia) is a common traditional Chinese medicine, which can promote the secretion and digestion of gastric juice, improve the function of gastrointestinal tract. Cinnamaldehyde (CA) is a synthetic food flavoring in the Chinese Pharmacopoeia. AIM OF THE STUDY: This study aimed to search for the active ingredient (CA) of inhibiting H. pylori from Cinnamomum cassia, and elucidate mechanism of action, so as to provide the experimental basis for the treatment of H. pylori infection with Cinnamomum cassia. MATERIALS AND METHODS: It's in vitro and in vivo pharmacological properties were evaluated based on minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and an acute gastric inflammation model in mice infected with H. pylori. Drug safety was evaluated using the CCK8 method and high-dose administration in mice. The advantageous characteristics of CA in inhibiting H. pylori were confirmed using acidic conditions and in combination with the antibiotics. The mechanism underlying the action of CA on H. pylori was explored using scanning electron microscopy (SEM), adhesion experiments, biofilm inhibition tests, ATP and ROS release experiments, and drug affinity responsive target stability (DARTS) screening of target proteins. The protein function and target genes were verified by molecular docking and Real-Time quantitative reverse transcription PCR (qRT-PCR). RESULTS: The results demonstrated that CA was found to be the main active ingredient against H. pylori in Cinnamomum cassia in-vitro tests, with a MIC of 8-16 µg/mL. Moreover, CA effectively inhibited both sensitive and resistant H. pylori strains. The dual therapy of PPI + CA exhibited remarkable in vivo efficacy in the acute gastritis mouse model, superior to the standard triple therapy. DARTS, molecular docking, and qRT-PCR results suggested that the target sites of action were closely associated with GyrA, GyrB, AtpA, and TopA, which made DNA replication and transcription impossible, then leading to inhibition of bacterial adhesion and colonization, suppression of biofilm formation, and inhibition ATP and enhancing ROS. CONCLUSIONS: This study demonstrated the suitability of CA as a promising lead drug against H. pylori, The main mechanisms can target GyrA ect, leading to reduce ATP and produce ROS, which induces the apoptosis of bacterial.

In vitro fermentation characteristics of polysaccharides from coix seed and its effects on the gut microbiota.

Coix seed polysaccharides had received increasing attention due to their diverse biological activities. In this study, a homogeneous polysaccharide (CSPW) was extracted and purified from coix seed. Furthermore, the saliva-gastrointestinal digestion and fecal fermentation behavior of CSPW were simulated in vitro. The results showed that CSPW was mainly composed of glucose. It cannot be degraded by the simulated salivary and intestinal digestive system, but can be degraded by the simulated gastric digestive system. After fermentation for 24 h, CSPW promoted the production of short-chain fatty acids (SCFAs), with acetic acid, propionic acid and n-butyric acid being the main metabolites. In addition, CSPW could significantly regulate the composition and microbial diversity of gut microbiota by increasing the relative abundance of beneficial bacteria, such as Limosilicactobacillus, Bifidobacterium and Collinsella. Finally, further analysis of functional prediction revealed that amino acid metabolism, nucleotide metabolism and carbohydrate metabolism were the most important pathways for CSPW to promote health. In summary, our findings suggested that CSPW could potentially be used as a good source of prebiotics because it can be used by gut microbiota to produce SCFAs and regulate the gut microbiota.

Long-term spatial distribution and implication of black and brown carbon in the Tibetan Plateau.

Black carbon (BC) and brown carbon (BrC) over the high-altitude Tibetan Plateau (TP) can significantly influence regional and global climate change as well as glacial melting. However, obtaining plateau-scale in situ observations is challenging due to its high altitude. By integrating reanalysis data with on-site measurements, the spatial distribution of BC and BrC can be accurately estimated using the random forest algorithm (RF). In our study, the on-site observations of BC and BrC were successively conducted at four sites from 2018 to 2021. Ground-level BC and BrC concentrations were then obtained at a spatial resolution of 0.25° × 0.25° for three periods (including Periods-1980, 2000, and 2020) using RF and multi-source data. The highest annual concentrations of BC (1363.9 ± 338.7 ng/m3) and BrC (372.1 ± 96.2 ng/m3) were observed during Period-2000. BC contributed a dominant proportion of carbonaceous aerosol, with concentrations 3-4 times higher than those of BrC across the three periods. The ratios of BrC to BC decreased from Period-1980 to Period-2020, indicating the increasing importance of BC over the TP. Spatial distributions of plateau-scale BC and BrC concentrations showed heightened levels in the southeastern TP, particularly during Period-2000. These findings significantly enhance our understanding of the spatio-temporal distribution of light-absorbing carbonaceous aerosol over the TP.

Effect of steam explosion pretreatment on the fermentation characteristics of polysaccharides from tea residue.

Green tea residues are the by-product of tea processing and they contain a large number of bioactive ingredients. Steam explosion has been recognized as one of the most innovative pretreatments for modifying the physicochemical characteristic of polysaccharides from lignocellulosic materials. However, the comparison of biological activity of steam exploded (SE-GTR) and unexploded (UN-GTR) green tea residue polysaccharides was still unclear, which prompted the determination of the efficacy of steam explosion in tea residue resource utilization. In this study, the effects of two extracted polysaccharides UN-GTR and SE-GTR on human gut microbiota in vitro fermentation were conducted. The results showed that after steam explosion pretreatment, SE-GTR displayed more loose and porous structures, resulting in higher polysaccharide content (2483.44±0.5 µg/mg) compared to UN-GTR (1903.56±2.6 µg/mg). In addition, after 24 h fermentation, gut microbiota produced more beneficial metabolites by SE-GTR. The largest SCFAs produced among samples was acetic acid, propionic acid and butyric acid. Furthermore, SE-GTR could regulate the composition and diversity of microbial community, increasing the abundance of beneficial bacteria, such as Bifidobacterium. These results revealed that steam explosion pretreatment could be a promising and efficient approach to enhance the antioxidant activity and bioavailability of polysaccharides isolated from tea residues.

Berberine alleviates ovarian tissue damage in mice with hepatolenticular degeneration by suppressing ferroptosis and endoplasmic reticulum stress.

OBJECTIVE: Hepatolenticular degeneration (HLD) is an autosomal recessive disorder that manifests as multiorgan damage due to impaired copper (Cu) metabolism. Female patients with HLD often experience reproductive impairments. This study investigated the protective effect of berberine against ovarian damage in toxic-milk (TX) mice, a murine model for HLD. METHODS: Mice were categorized into control group, HLD TX group (HLD group), penicillamine (Cu chelator)-treated TX group and berberine-treated TX group. Body weight, ovary weight and the number of ovulated eggs were recorded. Follicular morphology and cellular ultrastructure were examined. Total iron, ferrous iron (Fe2+) and trivalent iron (Fe3+) levels, as well as malondialdehyde (MDA), glutathione (GSH) and oxidized glutathione (GSSG), were measured in the ovaries. Western blot analysis was used to analyze the expression of proteins related to ferroptosis and endoplasmic reticulum (ER) stress. RESULTS: Ovarian tissue damage was evident in the HLD group, with a significant increase in ferroptosis and ER stress compared to the control group. This damage was inhibited by treatment with penicillamine, a Cu chelator. Compared with the HLD group, berberine increased the number of ovulations, and improved ovarian morphology and ultrastructure. Further, we found that berberine reduced total iron, Fe2+, MDA and GSSG levels, elevated GSH levels, decreased the expression of the ferroptosis marker protein prostaglandin-endoperoxide synthase 2 (PTGS2), and increased glutathione peroxidase 4 (GPX4) expression. Furthermore, berberine inhibited the expression of ER stress-associated proteins mediated by the protein kinase RNA-like ER kinase (PERK) pathway. CONCLUSION: Ferroptosis and ER stress are involved in Cu-induced ovarian damage in TX mice. Berberine ameliorates ovarian damage in HLD TX mice by inhibiting ferroptosis and ER stress. Please cite this article as: Liu QZ, Han H, Fang XR, Wang LY, Zhao D, Yin MZ, Zhang N, Jiang PY, Ji ZH, Wu LM. Berberine alleviates ovarian tissue damage in mice with hepatolenticular degeneration by suppressing ferroptosis and endoplasmic reticulum stress. J Integr Med. 2024; 22(4): 494-503.

Isobavachalcone: A redox antifungal agent impairs the mitochondria protein of Cryptococcus neoformans.

Isobavachalcone (IBC) is a natural small molecule with various biological activities; however, its inhibitory effects on Cryptococcus neoformans remain unclear. In our study, IBC showed a good antifungal effect. Through in vitro experiments, its minimum inhibitory concentration was 0.5-1 µg/mL. It exhibited the same antifungal effect as Amphotericin B in brain and lung infections in in vivo experiments. IBC also showed a synergistic antifungal effect with emodin with lower toxicity, and C. neoformans did not develop drug resistance to IBC. In the mechanistic study, significantly damaged mitochondria of C. neoformans, a significant reduction in mitochondrial membrane potential and adenosine triphosphate production, and an increase in hydrogen peroxide (H2O2) caused by IBC were observed using transmission electron microscopy. Through drug affinity-responsive target stability combined with phenotype detection, riboflavin synthases of aconitase and succinate dehydrogenase were screened. Molecular docking, quantitative polymerase chain reaction experiments, target inhibitor and agonist intervention, molecular interaction measurements, and minimum inhibitory concentration detection of the constructed expression strains revealed that IBC targeted the activity of these two enzymes, interfered by the tricarboxylic acid cycle, inhibited the production of adenosine triphosphate, blocked electron transport, reduced mitochondrial membrane potential, and induced antioxidation imbalance and reactive oxygen species accumulation, thus producing an antifungal effect. Therefore, IBC is a promising lead drug and redox antifungal agent for C. neoformans.