A Highly Selective and Sensitive Fluorescent Turn-Off Probe for Cu2+ Based on a Guanidine Derivative.

A new highly selective and sensitive fluorescent probe for Cu2+, N-n-butyl-4-(1'-cyclooctene-1',3',6'-triazole)-1,8-naphthalimide (L), was synthesized and evaluated. The structure of compound L was characterized via IR, ¹H-NMR, 13C-NMR and HRMS. The fluorescent probe was quenched by Cu2+ with a 1:1 binding ratio and behaved as a "turn-off" sensor. An efficient and sensitive spectrofluorometric method was developed for detecting and estimating trace levels of Cu2+ in EtOH/H2O. The ligand exhibited excitation and emission maxima at 447 and 518 nm, respectively. The equilibrium binding constant of the ligand with Cu2+ was 1.57 × 104 M-1, as calculated using the Stern.

YTE-17 inhibits colonic carcinogenesis by resetting antitumor immune response via Wnt5a/JNK mediated metabolic signaling.

The density and composition of lymphocytes infiltrating colon tumors serve as predictive factors for the clinical outcome of colon cancer. Our previous studies highlighted the potent anti-cancer properties of the principal compounds found in Garcinia yunnanensis (YTE-17), attributing these effects to the regulation of multiple signaling pathways. However, knowledge regarding the mechanism and effect of YTE-17 in the prevention of colorectal cancer is limited. In this study, we conducted isobaric tags for relative and absolute quantification (iTRAQ) analysis on intestinal epithelial cells (IECs) exposed YTE-17, both in vitro and invivo, revealing a significant inhibition of the Wnt family member 5a (Wnt5a)/c-Jun N-terminal kinase (JNK) signaling pathway. Subsequently, we elucidated the influence and mechanism of YTE-17 on the tumor microenvironment (TME), specifically focusing on macrophage-mediated T helper 17 (Th17) cell induction in a colitis-associated cancer (CAC) model with Wnt5a deletion. Additionally, we performed the single-cell RNA sequencing (scRNA-seq) on the colonic tissue from the Wnt5a-deleted CAC model to characterize the composition, lineage, and functional status of immune mesenchymal cells during different stages of colorectal cancer (CRC) progression. Remarkably, our findings demonstrate a significant reduction in M2 macrophage polarization and Th17 cell phenotype upon treatment with YTE-17, leading to the restoration of regulatory T (Treg)/Th17 cell balance in azoxymethane (AOM)/dextran sodium sulfate (DSS) model. Furthermore, we also confirmed that YTE-17 effectively inhibited the glycolysis of Th17 cells in both direct and indirect co-culture systems with M2 macrophages. Notably, our study shed light on potential mechanisms linking the non-canonical Wnt5a/JNK signaling pathway and well-established canonical ß-catenin oncogenic pathway in vivo. Specifically, we proposed that Wnt5a/JNK signaling activity in IECs promotes the development of cancer stem cells with ß-catenin activity within the TME, involving macrophages and T cells. In summary, our study undergoes the potential of YTE-17 as a preventive strategy against CRC development by addressing the imbalance with the immune microenvironment, thereby mitigating the risk of malignancies.

Dysregulation of Serum UCA1 and Its Clinical Significance in Patients with Acute Cerebral Infarction.

OBJECTIVE: To investigate the expression of lncRNA UCA1 in serum of patients with acute cerebral infarction (ACI) and its relationship with prognosis. METHODS: The serum lncRNA UCA1 level in participants was detected, and the correlation between the neurological function score (NIHSS score) of ACI patients and lncRNA UCA1 expression was analyzed. Patients were followed up at 3 months after discharge and were divided into favorable and unfavorable prognostic groups according to the modified Rankin scale (mRs). The risk factors of ACI patients with poor prognosis were analyzed, and the predictive value of each index for ACI prognosis was evaluated by ROC curve. RESULTS: The level of lncRNA UCA1 in ACI group was increased (P<0.001). ROC analysis showed that high lncRNA UCA1 expression had clinical significance for the diagnosis of ACI. Spearman correlation analysis revealed that NIHSS score was positively correlated with lncRNA UCA1 expression level in ACI group (r=0.6537, P<0.001). Hcy level and NIHSS score in poor prognosis group (n=63) were higher than those in good prognosis group (n=84), and lncRNA UCA1 level in serum in poor prognosis group was increased in comparison to good prognosis group (P<0.05). Logistic regression analysis investigated that admission NIHSS score, infarct size, and increased lncRNA UCA1 were the risk factors affecting the prognosis of ACI. CONCLUSION: Serum lncRNA UCA1 is abnormally elevated in ACI patients, and the elevated lncRNA UCA1 not only shows high accuracy in the diagnosis of ACI, but also has a certain predictive value for poor prognosis of ACI.

Exosomes derived from MDR cells induce cetuximab resistance in CRC via PI3K/AKT signaling­mediated Sox2 and PD­L1 expression.

The anti-EGFR antibody cetuximab is used as a first-line targeted therapeutic drug in colorectal cancer. It has previously been reported that the efficacy of the EGFR antibody cetuximab is limited by the emergence of acquired drug resistance. In our previous study the transmissibility effect of exosomes from drug resistant tumor cells to sensitive tumor cells was identified. It can therefore be hypothesized that drug resistant cells might affect neighboring and distant cells via regulation of exosome composition and behavior. However, the mechanism of exosomes in KRAS-wild-type colorectal cancer (CRC) remains unknown. In the present study, functional analysis of overall survival post-diagnosis in patients with KRAS wild-type and those with mutant CRC was performed using human CRC specimens. Furthermore, it was demonstrated that multidrug resistance (MDR) cancer cell-derived exosomes were potentially a key factor, which promoted cetuximab-resistance in CRC cells and reduced the inhibitory effect of cetuximab in CRC xenograft models. The Cell Counting Kit-8 and colony formation assays were performed to assess the effects of exosomes derived from CRC/MDR cells on cetuximab resistance. Sphere formation assay results demonstrated that exosomes derived from CRC/MDR cells altered the self-renewal and multipotential ability of stem-cell-associated markers and facilitated resistance to cetuximab in cetuximab-sensitive cells. Furthermore, exosomes derived from CRC/MDR cells decreased sensitivity to cetuximab via the activation of PI3K/AKT signaling, which promoted Sox2 and programmed death-ligand 1 (PD-L1) mRNA and protein expression according to reverse transcription-quantitative PCR, western blotting and immunohistochemistry analyses, as well as apoptosis resistance both in vitro and in vivo according to a TUNEL assay. In conclusion, the results of the present study demonstrated that exosomes derived from CRC/MDR cells may promote cetuximab resistance in KRAS wild-type cells via activation of the PI3K/AKT signaling pathway-mediated expression of Sox2 and PD-L1, which will be useful for investigating a potential clinical target in predicting cetuximab resistance.

Pulsatilla Decoction and its bioactive component ß-peltatin induce G2/M cell cycle arrest and apoptosis in pancreatic cancer.

BACKGROUND: Pancreatic cancer (PAC), a malignancy that is fatal and commonly diagnosed at a late stage. Despite considerable advancements in cancer treatment, the survival rate of PAC remains largely consistent for the past 60 years. The traditional Chinese medicine formula Pulsatilla Decoction (PD) has been clinically used to treat inflammatory diseases for millennia and recently as a supplementary anti-cancer treatment in China. However, the bioactive ingredients and mechanisms underlying its anti-cancer effect remains unclear. METHODS: The composition and quality control of PD were verified through analysis by high performance liquid chromatography. Cell viability was determined using Cell Counting Kit-8 assay. The cell cycle distribution was analyzed through PI staining and flow cytometry analysis, while apoptotic cells were measured by double staining with Annexin V-FITC and PI. We used immunoblotting to examine protein expressions. The in vivo effects of ß-peltatin and podophyllotoxin were evaluated on a subcutaneously-xenografted BxPC-3 cell nude mice model. RESULTS: The current study demonstrated that PD markedly inhibited PAC cell proliferation and triggered their apoptosis. Four herbal PD formula was then disassembled into 15 combinations of herbal ingredients and a cytotoxicity assay showed that the Pulsatillae chinensis exerted the predominant anti-PAC effect. Further investigation indicated that ß-peltatin was potently cytotoxic with IC50 of ~ 2 nM. ß-peltatin initially arrested PAC cells at G2/M phase, followed by apoptosis induction. Animal study confirmed that ß-peltatin significantly suppressed the growth of subcutaneously-implanted BxPC-3 cell xenografts. Importantly, compared to podophyllotoxin that is the parental isomer of ß-peltatin but clinically obsoleted due to its severe toxicity, ß-peltatin exhibited stronger anti-PAC effect and lower toxicity in mice. CONCLUSIONS: Our results demonstrate that Pulsatillae chinensis and particularly its bioactive ingredient ß-peltatin suppress PAC by triggering cell cycle arrest at G2/M phase and apoptosis.

Preparation of polyvinyl alcohol/chitosan nanofibrous films incorporating graphene oxide and lanthanum chloride by electrospinning method for potential photothermal and chemical synergistic antibacterial applications in wound dressings.

Electrospun fibres have been widely used as skin dressings due to their unique structur. However, due to the lack of intrinsic antimicrobial activity, it is easy for the wound to become infected. Bacterial infection, which leads to chronic inflammation, severely hinders the normal process of skin regeneration. In this study, a polyvinyl alcohol/chitosan (PVA/CS) composite films with chemical sterilization and near-infrared (NIR) photothermal antibacterial activity was fabricated by electrospinning. Graphene oxide (GO), a photosensitiser, was incorporated into the films, and lanthanum chloride (Lacl3) as a chemical antibacterial agent was also doped in the electrospun films. The structure, morphology, mechanical properties, wettability, and antimicrobial and photothermal antibacterial activity of the PVA/CS-based fibre films were investigated. The results showed that the addition of Lacl3 to the PVA/CS/GO nanofibres (PVA/CS/GO-La) improved the hydrophilicity, tensile strength and resistance to elastic deformation of the nanofibres. The PVA/CS/GO-La12.5 mM sample exhibited the best antibacterial performance, showing high inhibition against Staphylococcus aureus (82% antibacterial efficacy) and Escherichia coli (99.7% antibacterial efficacy). Furthermore, the antibacterial efficacy of the films surface was further enhanced after exposure to NIR light (808 nm, 0.01 W) for 20 min. In addition, the nanofibre films showed no cytotoxicity against human skin fibroblasts (HSFs), indicating its potential application in the field of broad-spectrum antibacterial materials.

A highly sensitive and selective fluorescent probe for determination of Cu (II) and application in live cell imaging.

A highly sensitive fluorescent probe, 2­butyl­6­(2­ethylidenehydrazinyl)­1H­benzo[de]isoquinoline­1,3(2H)­dione (P) has been designed and synthesized to detect Cu2+ in CH3CN-HEPES (4:1, v/v, pH = 7.4) solution. This probe functions via a distinctive hydrolysis mechanism through Cu2+-promoted accompany by extinction of the fluorescent and other competing metal ions did not showed any interference. The limit of detection toward Cu2+ was calculated of 320 nM. Probe P was not only successfully used for the determination of trace level Cu2+ in the CH3CN-HEPES (4:1, v/v, pH = 7.4) solution, but also valid for fluorescence imaging of Cu2+ in lysosomes of 293T cells and it was applied in real water samples. This work indicated that P would be of great application prospect in environmental monitoring and medical diagnosis.

A new perylene-based fluorescent pH chemosensor for strongly acidic condition.

A highly selective and sensitive pH chemosensor N,N-bis[(2-thiophene)-ethyl]-3,4,9,10-perylene tetracarboxylic diimide (TEPTD) was designed and synthesized through Schiff-base condensation reaction. It exhibited large Stokes shifts, good water solubility, excellent selectivity and outstanding photo-stability. The pKa of the probe was 3.0, which indicated that it could be used in highly acid conditions. With the addition of H+, the fluorescence intensity increased gradually. The sensing mechanisms involved photo-induced electron transfer, protonation and deprotonation, which were confirmed by 1H NMR titration experiment with trifluoroacetic acid. The probe can be used as a convenient probe to distinguish acidic from neutral or alkaline solutions by "naked-eye".

A novel dithiourea-appended naphthalimide "on-off" fluorescent probe for detecting Hg2+ and Ag+ and its application in cell imaging.

An effective dithiourea-appended 1,8-naphthalimide fluorescent probe was designed and synthesized. This probe could recognize Hg2+ and Ag+ sensitively and selectively in neutral and alkaline conditions. Moreover, the probe detected Hg2+ alone at pH between 2 and 6. The sensing ability of the probe was explored by UV-vis, fluorescence, FTIR and 1H NMR spectroscopy. The probe was quenched by Hg2+ and Ag+ with 1:1 binding ratios in MeCN/H2O (4/1, v/v) mixed solution with binding constants of 3.76 × 104 L mol-1 and 2.47 × 104 L mol-1, respectively. The linear concentration ranges for Hg2+ and Ag+ were 0-17 µmol L-1 and 0-24 µmol L-1 with detection limits of 0.83 µmol L-1 and 1.20 µmol L-1, respectively, which allowed for the quantitative determination of Hg2+ and Ag+. The new probe, 3a, was successfully applied to the fluorescence imaging of Hg2+ and Ag+ in HepG2 cells, demonstrating its potential application in biological science. Moreover, 3a was used to measure Hg2+ and Ag+ in tap water, drinking water and ultrapure water samples. The recoveries of Hg2+ and Ag+ in water samples were 96-99% and 98-103%, respectively. Therefore, the proposed method showed promising perspectives for its application, aimed at detecting Hg2+ and Ag+ in fluorescence imaging and real water samples.