Michael acceptor molecules in natural products and their mechanism of action.

Purpose: Michael receptor molecules derived from plants are biologically active due to electrophilic groups in their structure. They can target nucleophilic residues on disease-related proteins, with significant therapeutic effects and low toxicity for many diseases. They provide a good option for relevant disease treatment. The aim of this study is to summarize the existing MAMs and their applications, and lay a foundation for the application of Michael receptor molecules in life science in the future. Methods: This review summarizes the published studies on Michael receptor molecules isolated from plants in literature databases such as CNKI, Wanfang Data, PubMed, Web of Science, ScienceDirect, and Wiley. Latin names of plants were verified through https://www.iplant.cn/. All relevant compound structures were verified through PubChem and literature, and illustrated with ChemDraw 20.0. Result: A total of 50 Michael receptor molecules derived from various plants were discussed. It was found that these compounds have similar pharmacological potential, most of them play a role through the Keap1-Nrf2-ARE pathway and the NF-κB pathway, and have biological activities such as antioxidant and anti-inflammatory. They can be used to treat inflammatory diseases and tumors. Conclusion: The Michael receptor molecule has electrophilicity due to its unsaturated aldehyde ketone structure, which can combine with nucleophilic residues on the protein to form complexes and activate or inhibit the protein pathway to play a physiological role. Michael receptor molecules can regulate the Keap1-Nrf2-ARE pathway and the NF-κB pathway. Michael receptor molecules can be used to treat diseases such as inflammation, cancer, oxidative stress, etc.

Ru@N/S/TiO2/rGO: a high performance HER electrocatalyst prepared by dye-sensitization.

Hydrogen production from water-splitting is one of the most promising hydrogen production methods, and the preparation of the hydrogen evolution reaction (HER) catalyst is very important. Although Pt-based materials have the best catalytic activity for HER, their high price and scarcity greatly limit their large-scale industrial application prospects. Herein, a new method to prepare HER catalyst is described, where dyes used in dye-sensitized solar cells (DSSCs) were used as precursors. A high performance HER catalyst (Ru@N/S/TiO2/rGO, Ru nanoparticles (NPs) supported on N/S-doped TiO2/rGO hybrids) was prepared, and the stereoscopic molecular structure of the porphyrin dye, JR1, not only provides a prerequisite for the preparation of the hyperdispersed Ru NPs, but also successfully realizes N/S co-doping. The Ru@N/S/TiO2/rGO shows an excellent catalytic performance for the HER, which is almost the same as that with Pt/C. In 0.5 M H2SO4, the overpotential is 60 mV at 10 mA cm-2, and the Tafel slope is only 51 mV dec-1. In 1 M KOH, the overpotential is only 5 mV at 10 mA cm-2, and the Tafel slope is only 45 mV dec-1, and this performance is much better than most of the HER catalysts that have been reported. When Ru@N/S/TiO2/rGO is utilized as a catalyst in an alkaline water electrolyzer, a bias of only 1.52 V is able to complement overall water-splitting at 10 mA cm-2 (1.78 V, 100 mA cm-2). The molecular structure and coordination metal species of the dyes are easy to adjust, and the the stereoscopic structure is very helpful for inhibiting the aggregation of the metal NPs, and the strong anchoring effect with TiO2 or other carbon materials is also very helpful to achieve heteroatom doping. In addition, the process of dye-sensitization is simple and repeatable, and is a novel and efficient method to prepare the electrocatalyst.

Adipose mesenchymal stem cell-derived exosomes ameliorate hypoxia/serum deprivation-induced osteocyte apoptosis and osteocyte-mediated osteoclastogenesis in vitro.

Age-related skeletal changes is closely associated with imbalanced bone remodeling characterized by elevated osteocyte apoptosis and osteoclast activation. Since osteocytes are the commander of bone remodeling, attenuating increased osteocyte apoptosis may improve age-related bone loss. Exosomes, derived from mesenchymal stem cells, hold promising potential for cell-free therapy due to multiple abilities, such as promoting proliferation and suppressing apoptosis. We aimed to explore the effect of exosomes derived from adipose mesenchymal stem cell (ADSCs-exo) on osteocyte apoptosis and osteocyte-mediated osteoclastogenesis in vitro. The osteocyte-like cell line MLO-Y4 was used as a model, and apoptosis was induced by hypoxia and serum deprivation (H/SD). Our results showed that ADSCs-exo noticeably reduced H/SD-induced apoptosis in MLO-Y4 cells via upregulating the radio of Bcl-2/Bax, diminishing the production of reactive oxygen species and cytochrome c, and subsequent activation of caspase-9 and caspase-3. Additionally, ADSCs-exo lowered the expression of RANKL both at the mRNA and protein levels, as well as the ratio of RANKL/OPG at the gene level. As determined by tartrate-resistant acid phosphatase staining, reduced osteoclastogenesis was further validated in bone marrow monocytes cultured under conditioned medium from exosome-treated MLO-Y4. Together, ADSCs-exo could antagonize H/SD induced osteocyte apoptosis and osteocyte-mediated osteoclastogenesis, indicating the therapeutic potential of ADSCs-exo in age-related bone disease.

Inference of time-delayed gene regulatory networks based on dynamic Bayesian network hybrid learning method.

Gene regulatory networks (GRNs) research reveals complex life phenomena from the perspective of gene interaction, which is an important research field in systems biology. Traditional Bayesian networks have a high computational complexity, and the network structure scoring model has a single feature. Information-based approaches cannot identify the direction of regulation. In order to make up for the shortcomings of the above methods, this paper presents a novel hybrid learning method (DBNCS) based on dynamic Bayesian network (DBN) to construct the multiple time-delayed GRNs for the first time, combining the comprehensive score (CS) with the DBN model. DBNCS algorithm first uses CMI2NI (conditional mutual inclusive information-based network inference) algorithm for network structure profiles learning, namely the construction of search space. Then the redundant regulations are removed by using the recursive optimization algorithm (RO), thereby reduce the false positive rate. Secondly, the network structure profiles are decomposed into a set of cliques without loss, which can significantly reduce the computational complexity. Finally, DBN model is used to identify the direction of gene regulation within the cliques and search for the optimal network structure. The performance of DBNCS algorithm is evaluated by the benchmark GRN datasets from DREAM challenge as well as the SOS DNA repair network in Escherichia coli, and compared with other state-of-the-art methods. The experimental results show the rationality of the algorithm design and the outstanding performance of the GRNs.

Accurate prediction of subcellular location of apoptosis proteins combining Chou's PseAAC and PsePSSM based on wavelet denoising.

Apoptosis proteins subcellular localization information are very important for understanding the mechanism of programmed cell death and the development of drugs. The prediction of subcellular localization of an apoptosis protein is still a challenging task because the prediction of apoptosis proteins subcellular localization can help to understand their function and the role of metabolic processes. In this paper, we propose a novel method for protein subcellular localization prediction. Firstly, the features of the protein sequence are extracted by combining Chou's pseudo amino acid composition (PseAAC) and pseudo-position specific scoring matrix (PsePSSM), then the feature information of the extracted is denoised by two-dimensional (2-D) wavelet denoising. Finally, the optimal feature vectors are input to the SVM classifier to predict subcellular location of apoptosis proteins. Quite promising predictions are obtained using the jackknife test on three widely used datasets and compared with other state-of-the-art methods. The results indicate that the method proposed in this paper can remarkably improve the prediction accuracy of apoptosis protein subcellular localization, which will be a supplementary tool for future proteomics research.

[Clinical research on angiogenesis in colorectal carcinoma and expression of CK20 mRNA in peripheral blood].

OBJECTIVE: To investigate the correlation between microvessel density (MVD) and expression of vascular endothelial growth factor (VEGF) in tissues of colorectal carcinoma and the micrometastasis of tumor cells in these patients' peripheral blood. METHODS: The MVD and expression of VEGF were evaluated immunohistochemically while the micrometastasis of tumor cells in these patients' peripheral blood was detected by RT-PCR method. RESULTS: The average count of MVD in high and middle differentiation grade was 30.2 +/- 12.7, while in low differentiation grade 86.6 +/- 19.1. The expression of VEGF was positive in 26 patients (44.8%). The MVD and positive expression of VEGF were correlated to differentiations. stage and metastasis of colorectal carcinoma. CK(20) mRNA was found in peripheral blood of 32 patients (55.2%) and the positive rate was up to 60.4% 48 hours after operation, among which positive rate in the radical resection group was 47.7% and in the non-radical resection group 85.7%. 11 out of 21 patients positive in CK(20) mRNA turned to negative 7-14 d after radical resection, while 11 out of 12 patients remained positive at the same time after non-radical resection. The expression of CK(20) mRNA was correlated to the stage and metastasis of the cancer. The MVD and positive expression of VEGF were higher in patients with positive expression of CK(20) mRNA. CONCLUSIONS: The MVD and positive expression of VEGF were correlated to differentiation, stage and metastasis of colorectal carcinoma. The angiogenesis in tissues of colorectal carcinoma was closely related to the micrometastasis of tumor cells in these patients' peripheral blood. The detecting of CK(20)mRNA by RT-PCR may be a sensitive method for evaluating the micrometastasis colorectal carcinoma in peripheral blood and help in prognosis prediction, effect assessment and guidance of multipurpose therapy.

[Clinical significance of expression of VEGF and bFGF in thyroid carcinoma].

OBJECTIVE: To study the clinical significance of expression of VEGF and bFGF in thyroid carcinoma. METHODS: Immunohistochemical SP technic was used to investigate the expression of VEGF and bFGF in 90 cases of papillary carcinoma, 14 cases of undifferentiated carcinoma, 10 cases of normal thyroid tissue. RESULTS: The positive rate of VEGF and bFGF in thyroid carcinoma was 63.5% and 59.6% respectively, Which was significantly higher than that in normal thyroid tissue (P < 0.01); The positive rate of VEGF and bFGF in undifferentiated carcinoma was 92.9% and 85.7% respectively, which was significantly higher than that in papillary carcinoma (P < 0.05); The positive rate of expression of VEGF and bFGF was correlated with lymph gland metastasis (P < 0.05); A positive correlation between these two expresses existed in thyroid carcinoma (gamma = 0.596, P < 0.05). CONCLUSION: VEGF and bFGF can be regarded as a parameter to evaluate the biological behavior and prognosis of thyroid carcinoma.