Designing a Brightness-Restored Rhodamine Derivative by the Ortho-Compensation Effect for Assessing Drug-Induced Acute Kidney Injury.

Effective monitoring of essential bioindicators with high-contrast fluorescence imaging is highly crucial to reveal the pathological progression of diseases. However, most reported probes based on asymmetric amino-rhodamine (ARh) derivatives are often limited in practical application due to the low signal-to-noise ratios. Herein, a new fluorophore, 3-methoxy-amino-rhodamine (3-MeOARh), with improved fluorescence quantum yield (0.51 in EtOH) is designed and synthesized by introducing methoxy group in the ortho-position of amino in asymmetric amino-rhodamine. Notably, the good properties of the ortho-compensation effect further effectively enable the construction of an activatable probe with a high signal-to-noise ratio. As a proof of concept, the probe (3-MeOARh-NTR) was successfully synthesized for nitroreductase detection with high selectivity, excellent sensitivity, and good stability. More importantly, the relationship between drug-induced kidney hypoxia and elevated nitroreductase concentration was first uncovered in living tissues through high-contrast imaging. Therefore, the study presents the activatable probe for kidney hypoxia imaging while highlighting the 3-MeOARh structure with a satisfactory signal-to-noise ratio. It is believed that 3-MeOARh can serve as an efficient platform for activatable probe construction to reveal the pathological progression of different diseases.

MiR-22 restrains proliferation of rheumatoid arthritis by targeting IL6R and may be concerned with the suppression of NF-κB pathway.

It has demonstrated that miR-22 overexpression can suppress the inflammation process of rheumatoid arthritis (RA) in synoviocytes. But, the underlying mechanism of miR-22 expression in regulating RA is still not well illustrated. In this study, we investigated the functional role and underlying mechanism of miR-22 in regulating RA. Human RA fibroblast-like synoviocyte (FLS) cell line MH7A cells was transfected by miR-22 mimic and its control. CCK8 was utilized to detect cell proliferation. Cell apoptosis was analyzed by flow cytometry. MH7A cells stimulating with interleukin-1ß (IL-1ß) were transfected with miR-22 mimic. Quantitative real time polymerase chain reaction (qRT-PCR) and western blot assays were utilized to detect mRNA and protein expression. miR-22 targets were predicted and validated by Targetscan and luciferase reporter assay. We revealed that miR-22 showed downregulated expression in MH7A after stimulation with IL-1ß. Additionally, miR-22 overexpression suppressed the proliferation and facilitated apoptosis in MH7A cells. IL6R was a target of miR-22. Besides, miR-22 overexpression inhibited the expression of IL6R and also suppressed inflammatory pathway NF-κB. These results indicated that miR-22 overexpression could restrain the activity of inflammation cells in RA by targeting IL6R and might be concerned with the inhibition of NF-κB pathway.

Color-Tunable and Stimulus-Responsive Luminescent Liquid Crystalline Polymers Fabricated by Hydrogen Bonding.

Luminescent liquid crystalline polymers (LLCPs) show extensive application potentials, such as liquid crystal displays and circularly polarized luminescence. In this work, we employ a hydrogen-bonding strategy different from the traditional covalent-bonding method to fabricate LLCPs. First, the acceptor and donor of hydrogen bonding, (4,4'-dibutanoxy tetraphenylethylene)-1-pyridine (PTPEC4) and poly(2-vinyl terephthalic acid) (PPA), respectively, are successfully synthesized. Then, mixtures with different molar ratios ( x's) of PTPEC4 to PPA are used to prepare a series of LLCPs [denoted as PPA(PTPEC4) x]. The resultant LLCPs show a smectic A phase ( x ≥ 0.8), a columnar nematic phase (0.6 ≤ x ≤ 0.05), and an amorphous state ( x = 0.025), depending on the x value. Meanwhile, all polymers exhibit typical aggregation-induced emission behavior. More interestingly, with the variation of the PTPEC4 content, the series of LLCPs show different colors, that is, the emission peak red shifts from 510 nm ( x = 1.0) to 551 nm ( x = 0.025). Furthermore, because of the reversible protonation effect of the N atom of pyridine in PTPEC4 by the strong proton acid, PPA(PTPEC4) x shows reversible color transformation. This work provides a new method to construct LLCPs with different emission colors and reversible color transformation.