Insights into the pathogenesis of hereditary angioedema using genetic sequencing and recombinant protein expression analyses

BACKGROUND: The pathogenesis of hereditary angioedema (HAE) type I and type II is linked to defective C1 esterase inhibitor (C1-INH) encoded by the SERPING1 gene. There are substantial variabilities in the clinical presentations of patients with HAE that are not directly correlated to the serum levels of C1-INH. The impact of SERPING1 variants on C1-INH expression, structure, and function is incompletely understood. OBJECTIVE: To investigate the influence of SERPING1 variants on the C1-INH expression, structure, and function of 20 patients with HAE from 14 families with no prior genetic diagnosis. METHODS: Patients underwent whole-exome sequencing (WES). If no variants were identified, whole-genome sequencing (WGS) was performed. Except for the frameshift and large deletions, each C1-INH variant was recombinantly produced and, if synthesized and secreted, was subjected to structural, oligosaccharide, and functional analyses. RESULTS: We identified 11 heterozygous variants in the SERPING1 gene, of which 5 were classified as pathogenic (E85Dfs∗63, N166Qfs∗91, K201Qfs∗56, P399A, and R466H) and 6 as variants of uncertain significance (C130W, I224S, N272del, K273del, L349F, and F471C). Three large heterozygous deletions were discovered through WGS. Our data indicate that C130W, N272del, P399A, and F471C are poorly synthesized, I224S prevents proper C1-INH folding, and K273del impairs C1-INH function by adding an additional oligosaccharide. Further evaluation suggests that compound variant P399A/L349F contributes to a more severe clinical phenotype. CONCLUSIONS: Our combined approach of WES and WGS uncovered SERPING1 gene alternations in each patient. The recombinant protein production followed by systematic antigenic, structural, and functional assessment facilitates the identification of underlying pathogenic mechanisms in HAE

The transcription factor CREB is involved in sorafenib-inhibited renal cancer cell proliferation, migration and invasion

Our previous reports showed that the cyclic-AMP-response element-binding protein (CREB) served as a proto-oncogene in the process of tumorigenesis and mediated the growth and metastatic activity of renal cancer cells. Our study, therefore, explored the role of CREB in sorafenib-inhibited cell proliferation, migration and invasion. Renal cancer cells were cultured in medium containing sorafenib for 12, 24, 48 and 72 h. The MTT assay was used to study the cytotoxic effects of sorafenib. Cell invasion and migration were assayed in wound healing and transwell experiments, respectively. Protein expression levels were evaluated by western blotting. The results show that sorafenib treatment decreased cell viability in a dose- and time-dependent manner. Sorafenib inhibited cell migration and invasion and decreased the expression of MMP-2 and MMP-9. Moreover, addition of the recombinant plasmid pCI-neo/CREB (PN) reversed the sorafenib-induced inhibition of cell proliferation, migration and invasion. These results show that CREB is associated with the sorafenib-induced inhibition of proliferation, migration and invasion

Comparative Analysis of Bearing Current in Wind Turbine Generators

Bearing current problems frequently appear in wind turbine systems, which cause wind turbines the break down and result in very large losses. This paper investigates and compares bearing current problems in three kinds of wind turbine generators, namely doubly-fed induction generator (DFIG), direct-drive permanent magnet synchronous generator (PMSG), and semi-direct-drive PMSG turbines. Common mode voltage (CMV) of converters is introduced firstly. Then stray capacitances of three kinds of generators are calculated and compared through the finite element method. The bearing current equivalent circuits are proposed and simulations of the bearing current are carried out. It is verified that the bearing currents of DFIGs are more serious than the two kinds of PMSG, while common mode current (CMC) of the direct-drive PMSG is much greater than the other two types of wind turbine generators

The Transcription Factor Creb is Involved in Sorafenib-Inhibited Renal Cancer Cell Proliferation, Migration and Invasion

Our previous reports showed that the cyclic-AMP-response element-binding protein (CREB) served as a proto-oncogene in the process of tumorigenesis and mediated the growth and metastatic activity of renal cancer cells. Our study, therefore, explored the role of CREB in sorafenib- -inhibited cell proliferation, migration and invasion. Renal cancer cells were cultured in medium containing sorafenib for 12, 24, 48 and 72 h. The MTT assay was used to study the cytotoxic effects of sorafenib. Cell invasion and migration were assayed in wound healing and transwell experiments, respectively. Protein expression levels were evaluated by western blotting. The results show that sorafenib treatment decreased cell viability in a dose- and time-dependent manner. Sorafenib inhibited cell migration and invasion and decreased the expression of MMP-2 and MMP-9. Moreover, addition of the recombinant plasmid pCI-neo/ CREB (PN) reversed the sorafenib-induced inhibition of cell proliferation, migration and invasion. These results show that CREB is associated with the sorafenib-induced inhibition of proliferation, migration and invasion

Recent Progress and Future Prospect of CRISPR/Cas-Derived Transcription Activation (CRISPRa) System in Plants

Genome editing technology has become one of the hottest research areas in recent years. Among diverse genome editing tools, the Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated proteins system (CRISPR/Cas system) has exhibited the obvious advantages of specificity, simplicity, and flexibility over any previous genome editing system. In addition, the emergence of Cas9 mutants, such as dCas9 (dead Cas9), which lost its endonuclease activity but maintains DNA recognition activity with the guide RNA, provides powerful genetic manipulation tools. In particular, combining the dCas9 protein and transcriptional activator to achieve specific regulation of gene expression has made important contributions to biotechnology in medical research as well as agriculture. CRISPR/dCas9 activation (CRISPRa) can increase the transcription of endogenous genes. Overexpression of foreign genes by traditional transgenic technology in plant cells is the routine method to verify gene function by elevating genes transcription. One of the main limitations of the overexpression is the vector capacity constraint that makes it difficult to express multiple genes using the typical Ti plasmid vectors from Agrobacterium. The CRISPRa system can overcome these limitations of the traditional gene overexpression method and achieve multiple gene activation by simply designating several guide RNAs in one vector. This review summarizes the latest progress based on the development of CRISPRa systems, including SunTag, dCas9-VPR, dCas9-TV, scRNA, SAM, and CRISPR-Act and their applications in plants. Furthermore, limitations, challenges of current CRISPRa systems and future prospective applications are also discussed

Contributions of intestine and plasma to the presystemic bioconversion of Vicagrel, an acetate of clopidogrel

Purpose: To investigate the contributions of intestine and plasma to the presystemic bioconversion of vicagrel, and track its subsequent bioconversion to 2-oxo-clopidogrel in vivo and in vitro to rationalize the design of vicagrel, an acetate analogue of clopidogrel. Methods: The concentration-time profiles of 2-oxo-clopidogrel and active metabolite (AM) in presystem and circulation system was determined in the cannulated rats. Also, the rat intestinal S9 and human intestinal microsomes were conducted to examine the formation of 2-oxo-clopidogrel and AM. Meanwhile, the esterases in plasma and intestinal fractions responsible for the bioconversion of vicagrel to 2-oxo-clopidogrel were screened by the esterase inhibition and recombinant esterases. Results: The intestine was responsible for the formation of 2-oxo-clopidogrel and AM in vivo and in vitro, where carboxylesterases 2 (CE2) contributed greatly to the vicagrel cleavage during absorption. Other related esterases in plasma were paraoxonases (PON), carboxylesterases 1 (CE1) and butyrylcholine esterases (BChE). Conclusion: The findings rationalized the prodrug design hypothesis that vicagrel could overcome the extensive invalid hydrolysis of clopidogrel by the hepatic CE1 but experience the extensive hydrolysis to 2-oxo-clopidogrel and subsequent oxidation to AM in the intestine. This also supported the theory of improved pharmacological activity through facilitated formation of 2-oxo-clopidogrel, thus warranting much needed future clinical pharmacokinetic studies of vicagrel