Nitroreductase-Based "Turn-On" Fluorescent Probe for Bacterial Identification with Visible Features.

Among pathogenic bacteria, Escherichia coli, Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa were the six leading causes for the deaths associated with antibiotic resistance in 2019. Although new treatment options are urgently needed, the precise identification of the bacterial species remains pivotal for an accurate diagnosis and effective treatment. Clinically, mass spectrometry is used to distinguish these bacteria based on their protein mass pattern at the genus and species level. Herein, we report an alternative approach to identify these bacteria using the nitroreductase-based "turn-on" fluorescent probes (ETH1-NO2 and ETH2-NO2), with potential visual indicators for the six individual bacteria species. The limits of detection (LODs) of the probes for NTRs are 0.562 (ETH1-NO2) and 0.153 µg/mL (ETH2-NO2), respectively. They respond effectively to both Gram-positive and Gram-negative bacteria, with the lowest LOD at 1.2 × 106 CFU/mL for E. coli. In particular, different bacteria show noticeable difference in the apparent color of ETH1-NO2 samples, allowing possible identification of these bacteria visually. In addition, ETH1-NO2 also has potential applications in bacterial fluorescence imaging. Thus, our study provides an alternative approach for bacteria identification and new reagents for bacteria imaging.

A Cyanine Dye for Highly Specific Recognition of Parallel G-Quadruplex Topology and Its Application in Clinical RNA Detection for Cancer Diagnosis.

G-quadruplex (G4), an unconventional nucleic acid structure, shows polymorphism in its topological morphology. The parallel G4 topology is the most prevalent form in organisms and plays a regulatory role in many biological processes. Designing fluorescent probes with high specificity for parallel G4s is important but challenging. Herein, a supramolecular assembly of the anionic cyanine dye SCY-5 is reported, which selectively identifies parallel G4 topology. SCY-5 can clearly distinguish parallel G4s from other G4s and non-G4s, even including hybrid-type G4s with parallel characteristics. The high specificity mechanism of SCY-5 involves a delicate balance between electrostatic repulsion and π-π interaction between SCY-5 and G4s. Using SCY-5, cellular RNA extracted from peripheral venous blood was quantitatively detected, and a remarkable increase in RNA G4 content in cancer patients compared to healthy volunteers was confirmed for the first time. This study provides new insights for designing specific probes for parallel G4 topology and opens a new path for clinical cancer diagnosis using RNA G4 as a biomarker.

Design and Screening of Fluorescent Probes Based upon Hemicyanine Dyes for Monitoring Mitochondrial Viscosity in Living Cells.

Viscosity, at the subcellular level, plays a crucial role as a physicochemical factor affecting microenvironment homeostasis. Abnormal changes in mitochondrial viscosity often lead to various diseases in the organism. Based on the twisted intramolecular charge transfer mechanism, four hemicyanine dye fluorescent probes (HT-SA, HT-SA-S, HT-Bzh, and HT-NA) were designed and synthesized for viscosity response. The single bond between the nitrogen-containing heterocycle and the carbon-carbon double in the structure of the probe bond served as the viscosity response site. Finally, the probe HT-Bzh was screened as the optimal mitochondrial viscosity probe according to its responsiveness, targeting, and interference resistance. The fluorescence intensity of the probe HT-Bzh increased 22-fold when the viscosity was increased from 13.75 to 811.2 cP. In summary, all four viscosity probes we have developed can be used in different applications depending on the external environment, providing a valuable reference for the design of potential tools to address viscosity monitoring in biological systems.

G-quadruplex in mitochondria as a possible biomarker for mitophagy detection.

Mitochondrial autophagy (mitophagy) is a key physiological process that maintains the homeostasis of mitochondrial quality and quantity. Monitoring mitophagy is of great significance for detecting cellular abnormalities and developing therapeutic drugs. However, there are still very few biomarkers specifically developed for monitoring mitophagy. Here, we propose for the first time that mitochondrial G-quadruplex may serve as a biomarker for mitophagy detection, and develope a fluorescent light-up probe AMTC to monitor mitophagy in live cells. During mitophagy, AMTC fluorescence is significantly enhanced, but once mitophagy is inhibited, its fluorescence immediately decreases. The fluorescence behavior of AMTC implicates an increase in the formation of mitochondrial G-quadruplex during mitophagy. This inference has also been supported by the other two G-quadruplex probes. Taken together, this work provides a new possible biomarker and detection tool for the study of mitophagy.

SARS-CoV-2 vaccination in androgen sensitive phenotypes - A study on associated factors for SARS-CoV-2 vaccination and its adverse effects among androgenetic alopecia and benign prostate hyperplasia patients.

Background: Androgen sensitivity, which was established as the leading etiology of androgenetic alopecia (AGA) and benign prostatic hyperplasia (BPH), plays an important role in SARS-CoV-2 infection. Vaccination is essential for AGA and BPH patients in view of the high risk from SARS-CoV-2 infection. Purpose: We aimed to investigate the associated factors for SARS-CoV-2 vaccination and its side effects in populations with AGA and BPH. Method: We collected the data on SARS-CoV-2 vaccination and adverse reactions of male AGA and BPH patients visited the outpatient of Xiangya hospital by telephone and web-based questionnaires. Vaccination rate and adverse reactions were compared by different vaccine types and use of anti-androgen therapy. Result: A total of 457 AGA patients and 397 BPH patients were recruited in this study. Among which, 92.8% AGA patients and 61.0% BPH patients had at least the first dose of SARS-CoV-2 vaccination (p < 0.001). Having comorbidities and use of anti-androgen therapy increased the risk of un-vaccination among AGA by 2.875 and 3.729 times, respectively (p < 0.001). Around 31.1% AGA patients and 9.5% BPH patients presented adverse reactions, which were mostly mild. Anti-androgen therapy increased the inclination of injection site pain after vaccination (18.7% vs 11.9%; OR: 1.708, 95% CI: 1.088-2.683, p = 0.019). Conclusion: Co-existence of other systemic diseases and anti-androgen therapy were the limiting factors for SARS-CoV-2 unvaccination, especially in AGA patients. The importance of SARS-CoV-2 vaccines should be strengthened and popularized in androgen sensitive phenotypes.

Peripheral blood circulating microRNA-4636/-143 for the prognosis of cervical cancer.

Cervical cancer is the third leading cause of female death in the world. Serum microRNAs (miRNAs) are currently considered to be valuable as noninvasive cancer biomarkers, but their role in the prognosis of cervical cancer has not been elucidated. We aimed to find serum miRNAs that can be used as prognostic factors for cervical cancer. A traumatic pathological biopsy is the only reliable method for determining the severity of cervical cancer currently. Thus, noninvasive diagnostic markers are needed. The serological expression of candidate miRNAs were measured in 90 participants, including 60 patients with cervical cancer and 50 patients with cervical intraepithelial neoplasia. Two patients with cervical cancer were excluded from the study because of lack of data. miRNAs were evaluated by quantitative reverse transcription polymerase chain reaction. miR-143/-4636 appeared specific for cervical cancer compared with cervical intraepithelial neoplasia (P < .001). The classification performance of validated miRNAs for cervical cancer [Area under the receiver operating characteristic curve (AUC) = 0.942] was better than that reached by squamous cell carcinoma antigen (SCC-Ag; AUC = 0.727). Poor-differentiation group has lower miR-143/-4636 levels in serum (P < .05). miR-4636 level was correlated gross tumor volume and the depth of invasion (P < .0001). In our study, we found a combination of miR-143 and miR-4636 that is independently and strongly associated with cervical cancer prognosis and can be used as a clinically prognostic factor.