Environment-sensitive fluorescent inhibitors of histone deacetylase.

Histone deacetylases (HDACs) are proteases that can catalyze the deacetylation of histones to inhibit gene transcription. Since mutations and/or aberrant expression of various HDACs are frequently associated with human diseases, particularly cancers, HDACs are important therapeutic targets for many human tumors. However, there are still relatively few studies on HDAC small molecule fluorescent probes. Herein, we designed and synthesized a class of environment-sensitive fluorescent inhibitors with a switch mechanism to study HDAC activity. In vitro, the enzyme inhibition activity of compound 6b was comparable to the positive control drug SAHA, and it presented suitable imaging in living cells and tumor-tissue slices. This environment-sensitive fluorescent inhibitor provides a new idea for the diagnosis and treatment of HDACs-related diseases.

Bioluminescent Probe for Monitoring Endogenous Fibroblast Activation Protein-Alpha.

Fibroblast activation protein-α (FAP), as a crucial member of cell surface glycoprotein, highly expresses in reactive fibroblasts of tumors and several fibrosis diseases. It is a potential target for drug design and also reported as a prodrug strategy to increase the therapeutic window of some anticancer agents. In this work, we developed the first bioluminogenic probe for FAP with a limit-of-detection of 0.254 ng/mL, which could be applied to evaluate the FAP inhibitors in vitro. The experiments of transgenic mice and tumor-bearing nude mice validated our probe 1 could reflect the endogenous FAP level in vivo. Furthermore, this probe was successfully used to reflect FAP up-regulation in the lung homogenates of the bleomycin-induced idiopathic pulmonary fibrosis mice.

Bioluminescent Probe for Detection of Starvation-Induced Pantetheinase Upregulation.

Pantetheinase, a glycosylphosphatidylinositol (GPI) anchored enzyme, overexpresses in intestine, liver, and kidney with various biological functions such as its linkage to the inflammation and some metabolic diseases. It can hydrolyze pantetheine to cysteamine, an antioxidant, and pantothenic acid (Vitamin B5) that is an essential component of coenzyme A (CoA). Until now, very few analytic methods were developed for this enzyme, hampering the further investigation of its biological functions. In this work, we report the design, synthesis, and biological examination of a highly sensitive bioluminogenic probe for pantetheinase with a limit of detection of 1.14 ng/mL. Furthermore, animal experiments validated that our probe can be applied to detect the endogenous pantetheinase activity. To the best of our knowledge, this is the first bioluminogenic probe achieving the detection of pantetheinase level in vivo.

Aminoluciferin 4-hydroxyphenyl amide enables bioluminescence detection of endogenous tyrosinase.

Tyrosinase, a copper-containing enzyme existing widely in plants, animals and microorganisms, usually serves as an important biomarker in melanoma, and is also related to hyperpigmentation of the skin, melasma, age spots and albinism. At present, only one bioluminescent probe has been applied to image tyrosinase in cells. Thus, it's of great significance to develop a new bioluminescent probe that can detect tyrosinase in living cells and in live animals. In the current work, we report a new BL probe, TyrBP-3, which not detect tyrosinase in vitro and in living cells, but can also visualize the level of tyrosinase activity in tumors of living animals. In summary, TyrBP-3 is the first bioluminescent probe that can image tyrosinase on a cellular level. Hence, we anticipate that TyrBP-3 can be a good tool to monitor tyrosinase in complex biosystems in the future.

Visualization-Based Discovery of Vanin-1 Inhibitors for Colitis.

The main effect of Vanin-1/VNN1 is related to its pantetheinase sulfhydrylase activity, which can hydrolyze pantetheine into pantothenic acid and cysteamine. In recent studies, the enzymatic activity of vanin-1/VNN1 has been found to be essential in the development of many diseases. The study of specific vanin-1/VNN1 inhibitors can give us a deeper understanding of its role in the disease process. In this study, different skeletal inhibitors were designed and synthesized using pyrimidine amide compounds as lead compounds. In order to screen inhibitors intuitively, a fluorescent probe PA-AFC for in vitro evaluation of inhibitors was designed and synthesized in this study, which has good sensitivity and specificity. The bioluminescent probe PA-AL was then used for cellular level and in vivo inhibitor evaluation. This screening method was convenient, economical and highly accurate. Finally, these inhibitors were applied to a mouse colitis model, confirming that vanin-1 is useful in IBD and providing a new therapeutic direction.

Effect of Hydrothermal (Sr)-Hydroxyapatite Coatings on the Corrosion Resistance and Mg2+ Ion Release to Enhance Osteoblastic Cell Responses of AZ91D Alloy.

The biomedical applications of Mg-based alloys are limited by their rapid corrosion rate in the body fluid. In this study, the hydrothermal synthesis is employed to produce protective bioactive hydroxyapatite coating (HAC) and strontium-substituted hydroxyapatite coating (Sr-HAC) to further enhance the corrosion resistance and in vitro biocompatibility of biodegradable AZ91D Mg alloy in physiological environments. For comparison, the brucite Mg(OH)2 prepared by the alkaline pre-treatment is designated as a control group. Experimental evidences of XRD and XPS analysis confirm that Sr2+ ions can be incorporated into HA crystal structure. It is noted that the hydrothermally synthesized Sr-HAC conversion coating composed of a specific surface topography with the nanoscaled flake-like fine crystallites is constructed on the AZ91D Mg alloy. The hydrophilicity of Mg substrate is effectively enhanced with the decrease in static contact angles after performing alkaline and hydrothermal treatments. Potentiodynamic polarization measurements reveal that the nanostructured Sr-HAC-coated specimens exhibit superior corrosion resistance than HAC and alkaline pre-treated Mg(OH)2. Moreover, immersion tests demonstrate that Sr-HAC provides favorable long-term stability for the Mg alloy with decreasing concentration of released Mg2+ ions in the SBF and the reduced corrosion rate during the immersion length of 30 days. The cells cultured on Sr-HAC specimens exhibit higher viability than those on the alkaline-pre-treated Mg(OH)2 and HAC specimens. The Sr-substituted HA coating with a nanostructured surface topography can help to stimulate the cell viability of osteoblastic cells.

Effectiveness of electroacupuncture (EA) for the treatment of urinary incontinence (UI) in patients with spinal cord injury (SCI): A protocol of systematic review of randomized controlled trials.

BACKGROUND: The objective of this study is to examine the effectiveness and safety of electroacupuncture (EA) in the treatment of urinary incontinence (UI) in patients with spinal cord injury (SCI). METHODS: All potential studies will be retrieved from the electronic databases of MEDLINE, EMBASE, Cochrane Library, PsycINFO, Web of Science, CBM, and China National Knowledge Infrastructure from origin of each database up to January 31, 2020. Additionally, we will check other resources, such as Google scholar, dissertations, conference proceedings, and reference lists of included studies. No language and publication date limitations will be considered in the literature resources search. All randomized controlled trials using EA for the treatment of UI in patients with SCI will be included. Two independent investigators will perform study selection, data extraction and study quality assessment. If any conflicts occur, we will invite a third investigator to solve them. Cochrane risk of bias will be used for study quality assessment, and RevMan 5.3 software will be employed for statistical analysis. RESULTS: This study will summarize the most recent evidence to assess the effectiveness and safety of EA for the treatment of UI in patients with SCI. CONCLUSION: The results of this study will provide helpful evidence to determine whether EA is effective and safety for the treatment of UI in patients with SCI or not. PROSPERO REGISTRATION NUMBER: PROSPERO CRD42020165562.

Neuromuscular electrical stimulation for cancer pain in children with osteosarcoma: A protocol of systematic review.

BACKGROUND: This systematic review will assess the effectiveness and safety neuromuscular electrical stimulation (NMES) for cancer pain (CP) in children with osteosarcoma. METHODS: This systematic review protocol will retrieve the following electronic databases from inception to June 1 in Cochrane Library, MEDLINE, EMBASE, Web of Science, Scopus, CNKI, and VIP database. Manual head-searching of reference lists and conference proceedings will be performed to further examine the articles of interest. No restrictions will be applied to language and publication status. We will utilize a 3-stage approach to scan titles, abstracts, and full-text studies against all eligibility criteria, and collect data from included trials. Study quality will be evaluated by the Cochrane Risk of Bias Tool. If possible, we will narratively summarize study results and carry out meta-analysis. RESULTS: This study will recapitulate the present high quality trials to appraise the effectiveness and safety of NMES for CP in children with osteosarcoma. CONCLUSION: The findings of this study will present evidence to determine whether NMES is effective and safe for CP in children with osteosarcoma.