Construction of Near-Infrared Probes with Remarkable Large Stokes Shift Based on a Novel Purine Platform for the Visualization of mtG4 Upregulation during Mitochondrial Disorder in Somatic Cells and Human Sperms.

G-quadruplex structures within the nuclear genome (nG4) is an important regulatory factor, while the function of G4 in the mitochondrial genome (mtG4) still needs to be explored, especially in human sperms. To gain a better understanding of the relationship between mtG4 and mitochondrial function, it is crucial to develop excellent probes that can selectively visualize and track mtG4 in both somatic cells and sperms. Herein, based on our previous research on purine frameworks, we attempted for the first time to extend the conjugated structure from the C-8 site of purine skeleton and discovered that the purine derivative modified by the C-8 aldehyde group is an ideal platform for constructing near-infrared probes with extremely large Stokes shift (>220 nm). Compared with the compound substituted with methylpyridine (PAP), the molecule substituted with methylthiazole orange (PATO) showed better G4 recognition ability, including longer emission (∼720 nm), more significant fluorescent enhancement (∼67-fold), lower background, and excellent photostability. PATO exhibited a sensitive response to mtG4 variation in both somatic cells and human sperms. Most importantly, PATO helped us to discover that mtG4 was significantly increased in cells with mitochondrial respiratory chain damage caused by complex I inhibitors (6-OHDA and rotenone), as well as in human sperms that suffer from oxidative stress. Altogether, our study not only provides a novel ideal molecular platform for constructing high-performance probes but also develops an effective tool for studying the relationship between mtG4 and mitochondrial function in both somatic cells and human sperms.

Clinical and molecular characteristics of RNF43 mutations as promising prognostic biomarkers in colorectal cancer.

Background: Transmembrane E3 ubiquitin ligase (RNF43) mutations are present in approximately 6-18% of colorectal cancers (CRC) and could enhance Wnt/ß-catenin signaling, which is emerging as a promising therapeutic target. This study aims to investigate the clinical and molecular characteristics and potential heterogeneity of RNF43-mutant CRC. Methods: A total of 78 patients with RNF43-mutant CRC were enrolled from July 2013 to November 2022. Demographic data, clinical characteristics, treatment regimens used, and survival outcomes were collected and analyzed. Results: Our study uncovered that patients with RNF43 mutations in the N-terminal domain (NTD; n = 50) exhibited shorter overall survival (OS; median months, 50.80 versus not reached; p = 0.043) compared to those in the C-terminal domain (CTD; n = 17). Most RNF43 mutations in NTD had positive primary lymph node status, low tumor mutation burden (TMB-L), and correlated with proficient mismatch repair (pMMR)/microsatellite stable (MSS) status. By contrast, RNF43 mutations in CTD were significantly enriched in deficient MMR (dMMR)/microsatellite instability (MSI-H) tumors with high TMB (TMB-H). N-terminal RNF43-mutated tumors harbored a hotspot variant (RNF43 R117fs), which independently predicted a significantly worse outcome in pMMR/MSS CRC with a median OS of 18.9 months. Patients with RNF43 mutations and the BRAF V600E alterations demonstrated sensitivity to BRAF/EGFR inhibitors. Moreover, we observed that pMMR/MSS patients with RNF43 R117fs mutation had a higher incidence of stage IV, ⩾2 metastatic sites, low TMB, and none of them received PD-1/PD-L1 inhibitor therapy. Conclusion: Our findings provide the first evidence that RNF43 mutations in NTD and the R117fs variant correlate with a poorer prognosis in CRC patients, providing strategies for Wnt-targeted therapy to improve clinical efficacy.

Monitoring tumour resistance to the BRAF inhibitor combination regimen in colorectal cancer patients via circulating tumour DNA.

AIMS: This study aimed to identify mechanisms of drug resistance to the combination of vemurafenib, irinotecan, and cetuximab (VIC) in BRAFV600E metastatic colorectal cancer (mCRC). METHODS: Forty-one patients with BRAFV600E mCRC from July 2018 and June 2020 were evaluated, with tissue and/or plasma samples collected. We profiled tissue and plasma samples using whole-exome sequencing and targeted sequencing of 425 cancer-relevant genes. Clinical cohort analysis from published studies was performed to consolidate our findings. RESULTS: BRAF mutant in baseline plasma and its dynamics are significantly associated with VIC-related response, and concurrent RNF43 mutation significantly sensitises tumour to VIC treatment. VIC resistance frequently involves genes in PI3K, MAPK pathway, and several novel resistance mechanisms such as TGFBR2 and SMAD4 mutations, and copy-number gains in PTK2, MYC, and GATA6 have been identified. We also firstly describe acquired altered genes in DNA damaging repair pathway, occurring in 33 % of patients after VIC treatment, and particularly, patients with this pre-treatment resistance subclones developed inferior responses, along with higher tumour mutation burden both at baseline and progression plasma. CONCLUSION: Analysis of ctDNA can provide novel insights into molecular resistance mechanisms to VIC in BRAFV600E mCRC patients, allowing accurate guidance for clinicians in personalised treatment strategies.

Diagnostic Value of Combined Detection via Protein Induced by Vitamin K Absence or Antagonist II, Alpha-Fetoprotein, and D-Dimer in Hepatitis B Virus-Related Hepatocellular Carcinoma.

Purpose: We aimed to explore the clinical diagnostic value of combined detection via protein induced by vitamin K absence or antagonist II (PIVKA-II), alpha-fetoprotein (AFP), and D-dimer (D-D) in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). Materials and Methods: We analyzed PIVKA-II, AFP, and D-D levels in 291 subjects comprising liver cirrhosis (LC) patients (n = 143) and HCC patients (n = 148). Receiver operating characteristic (ROC) curves were used to analyze and compare the clinical diagnostic value of the three biomarkers for HBV-related HCC alone and in combination. Results: The levels of PIVKA-II, AFP, and D-D were positively correlated with tumor size in HCC patients. The levels of PIVKA-II and AFP in early-stage HCC, advanced HCC, HBV DNA+ HCC, and HBV DNA- HCC patients were higher than those in LC patients, while the levels of D-D were lower. The area under the curve for combined detection was greater than that for single-index detection in early-stage HCC, advanced HCC, HBV DNA+ HCC, and HBV DNA- HCC patients. Conclusion: D-D may be a useful biomarker for the diagnosis of HBV-related HCC. The combined detection of PIVKA-II, AFP, and D-D had better diagnostic value for different types of HCC than the detection of individual biomarkers.

Expression and Correlation of IgG4 and IL-21 in Collagen-Induced Arthritis Rats.

PURPOSE: We explored the expression levels of IgG4 and interleukin (IL)-21 in the serum and ankle joints of collagen-induced arthritis (CIA) rats at different disease stages. MATERIALS AND METHODS: Wistar rats were randomly divided into normal and model groups, and the latter group was administered bovine type II collagen to induce arthritis. Enzyme-linked immunosorbent assay was performed at 21, 28, 35, and 42 days to detect IgG4 and IL-21 in the serum, followed by histological and immunohistochemical analyses of IgG4 and IL-21r in the ankle joint of rats. RESULTS: The contents of IgG4 and IL-21 in the serum of the CIA model group were positively correlated and increased with disease progression. The expression of IgG4 and IL-21 receptors in the ankle joint of the CIA model group was significantly higher than that in the control group. These proteins were closely related to the pathological score. The serum IL-21 level in the model group was closely related to the level of IL-21 receptor in the ankle joint. CONCLUSION: IL-21 may promote the occurrence and development of rheumatoid arthritis by combining with IL-21r to regulate the content of IgG4.

Spermidine Inhibits Joints Inflammation and Macrophage Activation in Mice with Collagen-Induced Arthritis.

PURPOSE: Spermidine (SPD) is a naturally occurring polyamine. In this study, we examined the role and possible mechanism of SPD in collagen-induced arthritis (CIA) mice. MATERIALS AND METHODS: CIA mice were intraperitoneally injected with SPD (2 and 50 mg/kg), dexamethasone (0.5 mg/kg), or saline daily for 21 days. The severity of the disease and inflammatory responses in the serum and joint tissue were assessed through macroscopic, immunohistochemical, and histological analyses. RESULTS: Macroscopic and histological results indicated that SPD protected against the development of CIA. SPD suppressed the levels of the pro-inflammatory cytokines IL-6 and IL-1ß and increased the levels of the anti-inflammatory factor IL-10 in the serum. Immunohistochemical staining showed that 50 mg/kg SPD inhibited iNOS expression in synovial macrophages in the ankle joints of CIA mice. CONCLUSION: These results suggest that SPD may protect CIA mice by inhibiting the polarization of M1 macrophages in the synovial tissue, reducing pro-inflammatory cytokines, and promoting anti-inflammatory factor release.

Flavonoid fisetin reverses impaired hippocampal synaptic plasticity and cognitive function by regulating the function of AMPARs in a male rat model of schizophrenia.

Cognitive deficits are the core feature of schizophrenia and effective treatment strategies are still missing. Previous studies have reported that fisetin promotes long-term potentiation (LTP) and cognitive function in normal rodents and other model animals of neurological diseases. The aim of this study was to assess the effect of fisetin on synaptic plasticity and cognitive deficits caused by a brief disruption of N-methyl-D-aspartate receptors (NMDARs) with dizocilpine (MK-801) during early development in rats. The cognitive performance was examined by the Morris water maze task and a fear conditioning test. Hippocampal synaptic plasticity was investigated by field potential recording. The expression of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPARs) and cognition-related proteins was measured by western blotting. We found that intraperitoneal administration of fisetin rescued hippocampus-dependent spatial and contextual fear memory in MK-801 rats. In parallel with these behavioral results, fisetin treatment in MK-801 rats reversed the impairment of hippocampal LTP. At the molecular level, fisetin treatment selectively increased the phosphorylation and surface expression of AMPA receptor subunit 1 (GluA1) in MK-801-treated rats. Moreover, fisetin restored the phosphorylation levels of calcium-calmodulin-dependent kinaseII (CaMKII), cAMP response element-binding protein (CREB), and the extracellular signal-regulated kinase (ERK1/2) in MK-801-treated rats. Collectively, our findings demonstrate that fisetin treatment can reverse the deficits of hippocampal synaptic plasticity and memory in a male rat model of schizophrenia by restoring the phosphorylation and surface expression of AMPAR GluA1 subunit, suggesting fisetin as a promising therapeutic candidate for schizophrenia-associated cognitive deficits.

Lipid nanoparticles co-loaded with miRNA-22 and methotrexate for enhanced anti-inflammatory response in rheumatoid arthritis.

Present investigation was aimed at developing methotrexate (MTX) and miR-22 mimics-loaded lipid nanoparticles for the effective treatment of rheumatoid arthritis. The dual therapeutics loaded nanoparticles was prepared and subjected to in vitro and in vivo characterizations. The in vivo study was performed on adjuvant- induced arthritis model. The addition of IL-1ß significantly decreased the expression of miR-22 levels in negative control groups, whereas miR-22 mimics treated cells showed significantly higher miR-22 expression compared to both the NC groups. MTX+miR-22 showed significantly lower cell viability compared to that of free MTX indicating a synergistic anti-inflammatory in the MH7A cells. To be specific, MTX/miR-22-loaded lipid nanoparticles (MTmiR-NP) showed the significantly lower cell viability compared to any other group indicating the potential of lipid nanoparticles. Consistently, MTmiR-NP exhibited a significantly higher cell apoptosis (~50%) compared to any other tested group further reiterating the nanoparticle-based combinational therapeutics. MTmiR-NP exhibited the significant reduction in the paw thickness and significantly lower arthritic score compared to all other groups on all time points. Present study clearly highlights the potential of lipid nanoparticles-based synergistic combination of MTX and miR-22 in achieving higher therapeutic response in rheumatoid arthritis treatment.

Supramolecular chirality of coordination polymers of Ag+ with a chiral thiol ligand that bears a ß-turn structure.

We report coordination polymers forming from Ag+ and a chiral thiol ligand that bears a ß-turn structure, exhibiting supramolecular chirality showing both the majority rules effect (MRE) and the racemate rules effect (RRE).

In silico, in vitro and in vivo analyses of dipeptidyl peptidase IV inhibitory activity and the antidiabetic effect of sodium caseinate hydrolysate.

The frequency (A), a novel in silico parameter, was developed by calculating the ratio of the number of truncated peptides with Xaa-proline and Xaa-alanine to all peptide fragments from a protein hydrolyzed with a specific protease. The highest in vitro DPP-IV inhibitory activity (72.7%) was observed in the hydrolysate of sodium caseinate by bromelain (Cas/BRO), and the constituent proteins of bovine casein also had relatively high A values (0.10-0.17) with BRO hydrolysis. 1CBR (the <1 kDa fraction of Cas/BRO) showed the greatest in vitro DPP-IV inhibitory activity of 77.5% and was used for in vivo test by high-fat diet-fed and low-dose streptozotocin-induced diabetic rats. The daily administration of 1CBR for 6 weeks was effective to improve glycaemic control in diabetic rats. The results indicate that the novel in silico method has the potential as a screening tool to predict dietary proteins to generate DPP-IV inhibitory and antidiabetic peptides.