LC-MS/MS method for determination of r-RGD-hirudin in human plasma and its application in pharmacokinetic study.

OBJECTIVE: This study aimed to develop a simple, sensitive, and selective Liquid chromatography with a Mass spectroscopic method for simultaneous quantification of a recombinant bifunctional hirudin (r-RGD-Hirudin, Bifunctional Hirudin, BFH) in human plasma and verify its effectiveness. METHODS: The analytes and the internal standards from human plasma were extracted using the solid-phase extraction technique. The reconstituted samples were chromatographed on Waters C18 column (BEH 50 × 2.1 mm, 1.7 µm) using a mixture of 0.1% formic acid/acetonitrile (85%/15%, v/v) with gradient elution as the initial mobile phase at a flow rate of 0.3 mL/min. RESULTS: The effectiveness of the proposed method was verified over the concentration range of 10-2000 ng/mL for r-RGD-Hirudin. A linear calibration curve was obtained. The precision and accuracy of BFH in the intra- and inter-day runs fell within the range of ±15% at LQC, GMQC, MQC and HQC concentrations. The extraction recoveries and matrix effect at two quality control (QC) levels for BFH were confirmed to conform to the relevant requirement. CONCLUSION: The proposed method was successfully adapted to examine the pharmacokinetics of BFH in 40 Chinese healthy volunteers, respectively.

Topical VX-509 attenuates psoriatic inflammation through the STAT3/FABP5 pathway in keratinocytes.

BACKGROUND: Psoriasis is a chronic inflammatory disease, with lesions mainly manifesting as scaly erythematous plaques. The mild or moderate of psoriasis is the main type of patients in hospital, and topical application remains the preferred treatment option for psoriasis therapy, therefore, the development of novel topical agents has an essential role in psoriasis therapy. OBJECTIVE: To identify potential drugs for psoriasis topical treatment. METHODS: We performed drug screening by Imiquimod (IMQ)-induced psoriatic like inflammation in mouse model, followed mouse epidermis by RNA-seq to find the key molecules affecting the drug. The qRT-PCR, WB were performed to test mRNA and protein expression, and Chip assay had been conducted to examine Stat3 bound to promoter of FABP5. RESULTS: In this study, we identified VX-509, which topical application significantly attenuated IMQ-induced psoriatic like inflammation in mouse model. And then, we verified Epidermal Fatty acid binding protein (E-FABP/FABP5) was significantly decreased in VX-509 treated mouse epidermis by RNA-seq. FABP5 is a key molecule in lipid metabolism, administration of FABP5 inhibitor or knock down of FABP5 expression remarkably abrogated psoriatic inflammation as well as lipid metabolism. Mechanistically, our finding showed that VX-509 blocked IL-22 induced signaling pathway, particular in activation of Stat3. Furthermore, we identified Stat3 is a transcriptional factor associated with FABP5 promoters and VX-509 treatment remarkably attenuated IL-22-induced FABP5 expression through Stat3 in KCs. CONCLUSIONS: This study demonstrated administration of VX-509 is a potential promising topical drug for treatment of psoriasis, FABP5 is a critical targeted molecule in psoriasis therapy.

Physiological and biochemical responses of tea seedlings (Camellia sinensis) to simulated acid rain conditions.

Tea (Camellia sinensis), widely planted in the south of China, and often exposed to acid rain. However, research concerning the impacts of acid rain on physiology and biochemistry of tea plants is still scarce. In this study, we investigated the influence of simulated acid rain (SAR) on plant height, root length, photosynthetic pigment, Fv/Fm, proline, malondialdehyde, antioxidant enzyme activity, total nitrogen, caffeine, catechins, and free amino acids. Our results showed that SAR at pH 4.5 did not hinder plant development because growth characteristics, photosynthesis, and ascorbate peroxidase and catalase activities did not decrease at this pH compared to those at the other investigated pH values. However, at pH 3.5 and pH 2.5, the activities of antioxidase and concentrations of malondialdehyde and proline increased significantly in response to the decrease of photosynthetic pigments and Fv/Fm. In addition, the increase in acidity increased total nitrogen, certain amino acid content (theanine, cysteine), and decreased catechin and caffeine contents, resulting in an imbalance of the carbon and nitrogen metabolisms. Our results indicated that SAR at pH 3.5 and pH 2.5 could restrict photosynthesis and the antioxidant defense system, causing metabolic disorders and ultimately affecting plant development and growth, but SAR at pH 4.5 had no toxic effects on tea seedlings when no other stress factors are involved.

Porphyrinic Probe for Fluorescence "Turn-On" Monitoring of Cu+ in Aqueous Buffer and Mitochondria.

A zinc(II) porphyrin derivative (ZPSN) was designed and synthesized, and this probe exhibited rapid, selective and reversible binding to Cu+ for fluorescence monitoring in pure aqueous buffer. The detection mechanism is based on Cu+-activated disruption of axial coordination between the pyridyl ligand and the zinc center, which changes the molecular geometry and inhibits intramolecular electron transfer (ET), leading to fluorescence enhancement of the probe. The proposed sensing mechanism was supported by UV-vis spectroscopy/fluorescence spectral titration, NMR spectroscopy, mass spectrometry, and time-resolved fluorescence decay studies. The dissociation constant was calculated to be 6.53 × 10-11 M. CLSM analysis strongly suggested that ZPSN could penetrate live cells and successfully visualize Cu+ in mitochondria. This strategy may establish a design and offer a potential building block for construction of other metal sensors based on a similar mechanism.