Up/Down Tuning of Poly(ionic liquid)s in Aqueous Two-Phase Systems.

Thermally induced reversible up/down migration of poly(ionic liquid)s (PILs) in aqueous two-phase systems (ATPSs) was achieved for the first time in this study. Novel ATPSs were fabricated using azobenzene (Azo)- and benzyl (Bn)-modified PILs, and their upper and lower phases could be easily tuned using the grafting degree (GD) of the Azo and Bn groups. Bn-PIL with higher GDBn could go up into the upper phase and Azo-PIL come down to the lower phase when the temperature increased (>65 °C); this behavior was reversed at lower temperatures. Moreover, a reversible two-phase/single-phase transition was realized under UV irradiation. Experimental and simulation results revealed that the difference in the hydration capacity between Bn-PIL and Azo-PIL accounted for their unique phase-separation behavior. A versatile platform for fabricating ATPSs with tunable stimuli-responsive behavior can be realized based on our findings, which can broaden their applications in the fields of smart separation systems and functional material development.

Functional characterization of an anthocyanidin reductase gene from the fibers of upland cotton (Gossypium hirsutum).

MAIN CONCLUSION: Metabolic profiling, gene cloning, enzymatic analysis, ectopic expression, and gene silencing experiments demonstrate that the anthocyanidin reductase (ANR) pathway is involved in the biosynthesis of proanthocyanidins in upland cotton. Proanthocyanidins (PAs) are oligomeric or polymeric flavan-3-ols, however, the biosynthetic pathway of PAs in cotton remains to be elucidated. Here, we report on an anthocyanidin reductase (ANR) gene from cotton fibers and the ANR pathway of PAs. Phytochemical analysis demonstrated that leaves, stems, roots, and early developing fibers produced PAs and their monomers, including (-)-epicatechin, (-)-catechin, (-)-epigallocatechin, and (-)-gallocatechin. Crude PA extractions from different tissues were boiled in Butanol:HCl. Cyanidin, delphinidin, and pelargonidin were produced, indicating that cotton PAs include diverse extension unit structures. An ANR cDNA homolog (named GhANR1) was cloned from developing fibers. The open reading frame, composed of 1,011 bp nucleotides, was expressed in E. coli to obtain a recombinant protein. In the presence of NADPH, the recombinant enzyme catalyzed cyanidin, delphinidin, and pelargonidin to (-)-epicatechin and (-)-catechin, (-)-epigallocatechin and (-)-gallocatechin, and (-)-epiafzelechin and (-)-afzelechin, respectively. The ectopic expression of GhANR11 in an Arabidopsis ban mutant allowed for the reconstruction of the ANR pathway and PA biosynthesis in the seed coat. Virus-induced gene silencing (VIGS) of GhANR11 led to a significant increase in anthocyanins and a decrease in the PAs, (-)-epicatechin, and (-)-catechin in the stems and leaves of VIGS-infected plants. Taken together, these data demonstrate that the ANR pathway contributes to the biosynthesis of flavan-3-ols and PAs in cotton.

Novel 3-arylfuran-2(5H)-one-fluoroquinolone hybrid: design, synthesis and evaluation as antibacterial agent.

3-Arylfuran-2(5H)-one, a novel antibacterial pharmacophore targeting tyrosyl-tRNA synthetase (TyrRS), was hybridized with the clinically used fluoroquinolones to give a series of novel multi-target antimicrobial agents. Thus, twenty seven 3-arylfuran-2(5H)-one-fluoroquinolone hybrids were synthesized and evaluated for their antimicrobial activities. Some of the hybrids exhibited merits from both parents, displaying a broad spectrum of activity against resistant strains including both Gram-negative and Gram-positive bacteria. The most potent compound (11) in antibacterial assay shows MIC50 of 0.11µg/mL against Multiple drug resistant Escherichia coli, being about 51-fold more potent than ciprofloxacin. The enzyme assays reveal that 11 is a potent multi-target inhibitor with IC50 of 1.15±0.07µM against DNA gyrase and 0.12±0.04µM against TyrRS, respectively. Its excellent inhibitory activities against isolated enzymes and intact cells strongly suggest that 11 deserves to further research as a novel antibiotic.

Case report: A case study of neoadjuvant immunochemotherapy for locally advanced esophageal squamous carcinoma.

In locally advanced esophageal cancer, the controversy over the two traditional treatment modalities, neoadjuvant radiotherapy and neoadjuvant chemotherapy, has been unending and also challenged by the addition of neoadjuvant immunotherapy. Neoadjuvant immunotherapy has led to an increasing diversity of neoadjuvant combination treatment modalities, among which neoadjuvant immunochemotherapy has emerged, with current clinical studies initially demonstrating its efficacy and safety. We report a case of a patient with locally advanced esophageal cancer who underwent two cycles of neoadjuvant immunochemotherapy and successful surgery and achieved a pathological complete response (pCR). A 73-year-old elderly female patient presented with progressive dysphagia for more than 1 month with an Eastern Cooperative Oncology Group (ECOG) score of 1. After completing gastroscopy + pathological biopsy, chest enhanced CT, barium esophageal meal, PET-CT, and other related examinations, the clinical diagnosis was thoracic segmental esophageal poorly differentiated squamous carcinoma cT2N2M0 stage III. After a multidisciplinary discussion of the comprehensive treatment plan, two cycles of neoadjuvant therapy were given on February 16, 2023, and March 9, 2023, and the treatment plan was as follows: cisplatin 30 mg d1-3 + albumin paclitaxel 200 mg d1 and 100 mg d8 + sintilimab 200 mg d4, q3w. After the neoadjuvant therapy, the patient underwent an imaging examination. The chest enhanced CT suggested that the lesion range was significantly reduced compared with the previous scan, and mediastinal lymph nodes were partially reduced. Then, thoracoscopic radical esophageal cancer surgery was performed on April 23, 2023. pCR was achieved by pathological evaluation, and the postoperative diagnosis was thoracic segmental esophageal hypofractionated squamous carcinoma ypT0N0M0. Two cycles of adjuvant immunochemotherapy were performed after surgery on May 30, 2023, and June 21, 2023, and the regimen was as follows: cisplatin 30 mg d1-3 + albumin paclitaxel 200 mg d1 and 100 mg d8 + sindilizumab 200 mg d4, q3w. As of the latest review on March 20, 2024, the patient was not seen to have any significant postoperative complications and remains in a state of complete response (CR). Neoadjuvant immunochemotherapy has positive significance for the treatment of patients with locally advanced esophageal cancer. Whether neoadjuvant immunochemotherapy can replace neoadjuvant synchronous radiotherapy is a future direction of research, which needs to be further verified by more reliable clinical trials.

[Cloning, prokaryotic expression and characterization of lysine decarboxylase gene from Huperzia serrata].

Huperzine A is a promising drug to treat Alzheimer's disease (AD). To date, its biosynthetic pathway is still unknown. Lysine decarboxylase (LDC) has been proposed to catalyze the first-step of the biosynthesis of huperzine A. To identify and characterize LDCs from Huperzia serrata, we isolated two LDC fragments (LDC1 and LDC2) from leaves of H. serrata by RT-PCR and then cloned them into pMD 19-T vector. Sequence analysis showed that LDC1 and LDC2 genes shared 95.3% identity and encoded the protein of 212 and 202 amino acid residues respectively. Thus, we ligated LDC genes into pET-32a(+) to obtain recombinant expressing vectors pET-32a(+)/LDC1 and pET-32a(+)/LDC2 respectively. We further introduced two expression vectors into Escherichia coli BL21(DE3) and cultured positive colonies of E. coli in liquid LB medium. After inducing for 4 hours with 260 µg/mL IPTG at 30 degrees C, soluble recombinant Trx-LDC1 and Trx-LDC2 were obtained and isolated for purification using a Ni-NTA affinity chromatography. We incubated purified recombinant proteins with L-lysine in the enzyme reaction buffer at 37 degrees C and then derived the reaction products using dansyl chloride. It was found that both Trx-LDC1 and Trx-LDC2 had decarboxylase activity, could convert L-lysine into cadaverine by way of thin layer chromatography assay. Further, bioinformatics analysis indicated that deduced LDC1 and LDC2 had different physicochemical properties, but similar secondary and three-dimensional structures.

Proteomic analyses of Sirt1-mediated cisplatin resistance in OSCC cell line.

Oral squamous cell carcinoma (OSCC) accounts for about 90% of malignant oral lesions, and is recognized as the third most common cancer in developing nations and the sixth most common cancer worldwide. While chemotherapy remains the primary treatment for both resectable and advanced OSCC, most OSCC are naturally resistant to anticancer drugs, rendering new therapeutic avenues in dire need. Sirt1, a class III histone deacetylase, was linked to cisplatin resistance in several cancer types; however, the underlying mechanism is still unclear. Here, we demonstrated that overexpression of Sirt1 survived OSCC cell line Tca8113 under cisplatin treatment. Notably, BML-210, a chemical inhibitor of class III histone deacetylase, significantly abolished Sirt1-mediated cisplatin resistance in Tca8113 cells. Further, inactivation of endogenic Sirt1 by nicotinamide markedly increased chemo-sensitivity in cisplatin resistant sub-cell line Tca8113/CDDP. Proteomic strategy was applied to profile the differentially expressed proteins between pcDNA3.1-Sirt1- and mock vector-treated Tca8113 cells. Among 54 spots identified, 31 proteins were up-regulated and 23 proteins were down-regulated upon Sirt1 expression. Expression of four proteins with most significant alteration, including Annexin A4, Stathmin, SOD2 and thioredoxin, were validated by both RT-PCR and Western blot. Finally, we showed that Sirt1 could prevent cisplatin-induced ROS accumulation in Tca8113 cells. Our findings are considered as a significant step toward a better understanding of Sirt1-mediated cisplatin resistance.