Organocatalyzed Photoelectrochemistry for the Generation of Acyl and Phosphoryl Radicals through Hydrogen Atom-Transfer Process.

An organocatalyzed photoelectrochemical method for the generation of acyl and phosphoryl radicals from formamides, aldehydes, and phosphine oxides has been developed. This protocol utilizes 9,10-phenanthrenequinone (PQ) as both a molecular catalyst and a hydrogen atom-transfer (HAT) reagent, eliminating the requirement for external metal-based reagents, HAT reagents, and oxidants. The generated acyl radicals can be applied to a range of radical-mediated transformation reactions, including C-H carbamoylation of heteroarenes, intermolecular tandem radical cyclization of CF3-substituted N-arylacrylamides, as well as intramolecular cyclization reactions. The use of acyl radicals in these transformations offers an efficient and sustainable approach to accessing structurally diverse carbonyl compounds.

Effects of dual-gene modification on biological characteristics of vascular endothelial cells and their significance as reserving cells for chronic wound repair.

bFGF is a commonly used and reliable factor for improving chronic wound healing, and hSulf-1 expression is abundant in surrounding cells of chronic wound tissue and vascular endothelial cells, which can reverse the effect of bFGF and inhibit the signalling activity of cell proliferation. In this study, an adenovirus, Ad5F35ET1-bFGF-shSulf1, was designed for establishing the dual-gene modified vascular endothelial cells, which were used as the repair cells for skin chronic wound. Ad5F35ET1-bFGF-shSulf1 infected ECV304 cells in vitro and mediated the overexpression of bFGF and the knockdown of hSulf-1, which effectively activated the AKT and ERK signal transduction pathways, facilitate cell proliferation and migration, with the cell viability to 128.29% at 72 h after infection, compared to 66.65%, 73.74%, 87.63%, 103.14% in the blank control, Ad5F35ET1-EGFP-shNC, Ad5F35ET1-shSulf1, Ad5F35ET1-bFGF groups, respectively. In the rat ear skin injury model, the wound healing was significantly accelerated in the Ad5F35ET1-rbFGF-shrSulf1 group compared to the blank control group (p = 0.0046), Ad5F35ET1-EGFP-shNC group (p = 0.0245), Ad5F35ET1-shrSulf group (p = 0.0426), and Ad5F35ET1-rbFGF group (p = 0.2853). The results demonstrated that this strategy may be a candidate therapy for chronic injury repair.

Crenobacter intestini sp. nov., Isolated from the Intestinal Tract of Konosirus punctatus.

A novel Gram-stain-negative bacterium, designated strain GY 70310T, was isolated from the intestinal tract of Konosirus punctatus collected from Minjiang River, China. Cells of the strain were rod-shaped and motile with a single polar flagellum. The result of 16S rRNA gene sequence analyses showed that strain GY 70310T was moderately related to Crenobacter luteus YIM 78141T (94.7%), Paludibacterium paludis KBP-21T (93.8%) and Crenobacter cavernae K1W11S-77T (93.0%). The draft genome of strain GY 70310T consisted of 3.4 Mbp with DNA G+C content of 66.3 mol%, which possessed genes putatively encoding nitrate reductase, nitrite oxidoreductase and urease. The novel strain showed a whole genome average nucleotide identity (OrthoANI) value of 77.1% and a digital DNA-DNA hybridization (dDDH) value of 22.4% with Crenobacter luteus DSM 27258T, followed by Crenobacter cavernae K1W11S-77T with OrthoANI and dDDH values of 76.4% and 20.6%, respectively. The major fatty acids (>10%) were identified as summed feature 3 (C16:1ω6c and/or iso-C15:0 2-OH, C16:1ω7c), C16:0 and C18:1ω7c. The major respiratory quinone was ubiquinone-8 (Q-8). The polar lipids comprised diphosphatidylglycerol, phosphatidylethanolamine, one unidentified aminophospholipid, one unidentified lipid and one unidentified phospholipid. On the basis of phylogenetic analyses, genotypic and chemotaxonomic characteristics, strain GY 70310T represents a novel species of the genus Crenobacter, for which the name Crenobacter intestini sp. nov., is proposed. The type strain is GY 70310T (= CGMCC 1.16821T = KCTC 62945T = NBRC 113900T).

DNA sequencing and CRISPR-Cas9 gene editing for target validation in mammalian cells.

Identification and validation of drug-resistant mutations can provide important insights into the mechanism of action of a compound. Here we demonstrate the feasibility of such an approach in mammalian cells using next-generation sequencing of drug-resistant clones and CRISPR-Cas9-mediated gene editing on two drug-target pairs, 6-thioguanine-HPRT1 and triptolide-ERCC3. We showed that disrupting functional HPRT1 allele or introducing ERCC3 point mutations by gene editing can confer drug resistance in cells.

Dual actions of Meis1 inhibit erythroid progenitor development and sustain general hematopoietic cell proliferation.

Myeloid ecotropic viral integration site 1 (Meis1) forms a heterodimer with Pbx1 that augments Hox-dependent gene expression and is associated with leukemogenesis and HSC self-renewal. Here we identified 2 independent actions of Meis1 in hematopoietic development: one regulating cellular proliferation and the other involved in megakaryocyte lineage development. First, we found that endogenous Mesp1 indirectly induces Meis1 and Meis2 in endothelial cells derived from embryonic stem cells. Overexpression of Meis1 and Meis2 greatly enhanced the formation of hematopoietic colonies from embryonic stem cells, with the exception of erythroid colonies, by maintaining hematopoietic progenitor cells in a state of proliferation. Second, overexpression of Meis1 repressed the development of early erythroid progenitors, acting in vivo at the megakaryocyte-erythroid progenitor stage to skew development away from erythroid generation and toward megakaryocyte development. This previously unrecognized action of Meis1 may explain the embryonic lethality observed in Meis1(-/-) mice that arises from failure of lymphatic-venous separation and can result as a consequence of defective platelet generation. These results show that Meis1 exerts 2 independent functions, with its role in proliferation of hematopoietic progenitors acting earlier in development from its influence on the fate choice at the megakaryocyte-erythroid progenitor between megakaryocytic and erythroid development.

A non-synonymous SNP in the NOS2 associated with septic shock in patients with sepsis in Chinese populations.

Sepsis represents a systemic inflammatory response to infection and its sequelae include severe sepsis, septic shock, multiple organ dysfunction syndrome (MODS) and death. Studies in mice and humans indicate that the inducible nitric oxide synthase (iNOS, NOS2) plays an important role in the development of sepsis and its sequelae. It was reported that several single nucleotide polymorphisms (SNPs) within NOS2 could influence the production or activity of NOS2. In this study, we assessed whether SNPs within NOS2 gene were associated with severity of sepsis in Chinese populations. A case-control study was conducted, which included 299 and 280 unrelated patients with sepsis recruited from Liaoning and Jiangsu provinces in China, respectively. Six SNPs within NOS2 were genotyped using Sequenom MassARRAY system. The associations between the SNPs and risk of sepsis complications were estimated by a binary logistic regression model adjusted for confounding factors. Functional assay was performed to assess the biological significance. The GA + AA genotype of a non-synonymous SNP in the exon 16 of NOS2 (rs2297518: G>A) was significantly associated with increased susceptibility to septic shock compared with GG genotype in Liaoning population (OR = 3.29, 95% CI = 1.40-7.72, P = 0.0047). This association was confirmed in the Jiangsu population (OR = 3.49, 95% CI = 1.57-7.79, P = 0.0019). Furthermore, the functional assay performed in the immortalized lymphocyte cell lines indicated that the at-risk GA genotype had a tendency of higher NOS2 activity than the GG genotype (P = 0.32). Our findings suggest that the NOS2 rs2297518 may play a role in mediating the susceptibility to septic shock in patients with sepsis in Chinese populations.

Antiviral efficacy of RAY1216 monotherapy and combination therapy with ritonavir in patients with COVID-19: a phase 2, single centre, randomised, double-blind, placebo-controlled trial.

Background: This study aimed to evaluate the efficacy and safety of RAY1216, a novel inhibitor of 3-chymotrypsin-like cysteine protease (3CLpro), in adults with coronavirus disease 2019 (COVID-19). Methods: This phase 2, single centre, randomised, double-blind, placebo-controlled trial included hospitalised patients between August 14, 2022, and September 26, 2022, in Sanya Central Hospital (The Third People's Hospital of Hainan Province) in China with no severe symptoms if they had laboratory-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection for not more than 120 h (5 days) and a real-time quantitative polymerase chain reaction (qPCR) cycle threshold (Ct) value of ≤30 for both the open reading frames 1 ab (ORF1ab) and nucleocapsid (N) genes within 72 h before randomisation. Half of the participants (n = 30) were randomly assigned (2:1) to receive either RAY1216 or a matched placebo three times a day (TID) for 5 days (15 doses in total), while the other half received RAY1216 plus ritonavir (RAY1216 plus RTV) or a matched placebo every 12 h for 5 days (10 doses in total). The primary endpoint was the time of viral clearance. Secondary outcomes included the changes of the SARS-CoV-2 RNA viral load, the positivity rate of the nucleic acid test, and the recovery time of clinical symptoms. A safety evaluation was performed to record and analyse all adverse events that occurred during and after drug administration as well as any cases in which dosing was halted because of these events. Clinicaltrials.gov identifier: ChiCTR2200062889. Findings: The viral shedding times in the RAY1216 and RAY1216 plus RTV groups were 166 h (95% confidence interval (CI): 140-252) and 155 h (95%CI: 131-203), respectively, which were 100 h (4.2 days) and 112 h (4.6 days) shorter than that of the placebo group, respectively (RAY1216 group vs. Placebo p = 0.0060, RAY1216 plus RTV group vs. Placebo p = 0.0001). At 24 h, 72 h, and 120 h after administration, the viral RNA loads in the RAY1216 and RAY1216 plus RTV groups were significantly less than those of the placebo groups. At 280 h (11.5 days) after administration, the nucleic acid test results in the RAY1216 and RAY1216 plus RTV groups were both negative. The common adverse events related to the investigational drugs were mild and self-limiting laboratory examination abnormalities. Interpretation: Our findings suggest that RAY1216 monotherapy and RAY1216 plus ritonavir both demonstrated significant antiviral activity and reduced the duration of COVID-19 while maintaining a satisfactory safety profile. Considering the limited clinical application of RTV, it is recommended to use RAY1216 alone to further verify its efficacy and safety. Funding: This study was sponsored by the Key Research and Development Program of China (2022YFC0868700).

Snail and the microRNA-200 family act in opposition to regulate epithelial-to-mesenchymal transition and germ layer fate restriction in differentiating ESCs.

The reprogramming of somatic cells to inducible pluripotent stem cells requires a mesenchymal-to-epithelial transition. While differentiating ESCs can undergo the reverse process or epithelial-to-mesenchymal transition (EMT), little is known about the role of EMT in ESC differentiation and fate commitment. Here, we show that Snail homolog 1 (Snail) is expressed during ESC differentiation and is capable of inducing EMT on day 2 of ESC differentiation. Induction of EMT by Snail promotes mesoderm commitment while repressing markers of the primitive ectoderm and epiblast. Snail's impact on differentiation can be partly explained through its regulation of a number of ESC-associated microRNAs, including the microRNA-200 (miR-200) family. The miR-200 family is normally expressed in ESCs but is downregulated in a Wnt-dependent manner during EMT. Maintenance of miR-200 expression stalls differentiating ESCs at the epiblast-like stem cell (EpiSC) stage. Consistent with a role for activin in maintaining the EpiSC state, we find that inhibition of activin signaling decreases miR-200 expression and allows EMT to proceed with a bias toward neuroectoderm commitment. Furthermore, miR-200 requires activin to efficiently maintain cells at the epiblast stage. Together, these findings demonstrate that Snail and miR-200 act in opposition to regulate EMT and exit from the EpiSC stage toward induction of germ layer fates. By modulating expression levels of Snail, activin, and miR-200, we are able to control the order in which cells undergo EMT and transition out of the EpiSC state.

Discovery of Small-Molecule CD33 Pre-mRNA Splicing Modulators.

CD33/Siglec 3 is a myeloid lineage cell surface receptor that is known to regulate microglia activity. Multiple genome-wide association studies (GWAS) have identified genetic variants in the CD33 gene that convey protection from late-onset Alzheimer's disease. Furthermore, mechanistic studies into GWAS-linked variants suggest that disease protection is attributed to the alternative splicing of exon 2 of the CD33 pre-mRNA. Using a phenomimetic screen, a series of compounds were found to enhance the exclusion of CD33 exon 2, acting as a chemomimetic of the GWAS-linked gene variants. Additional studies confirmed that meyloid lineage cells treated with several of these compounds have a reduced full-length V-domain containing CD33 protein, while targeted RNA-seq concordantly demonstrated that compound 1 increases exon 2 skipping in cellular mRNA pools. These studies demonstrate how pharmacological interventions can be used to manipulate disease-relevant pre-mRNA splicing and provide a starting point for future efforts to identify small molecules that alter neuroimmune function that is rooted in the human biology of neurodegenerative disease.

Targeted genome editing tools for disease modeling and gene therapy.

The development of custom-designed nucleases (CDNs), including zinc finger nucleases (ZFNs) and transcription activator-like effector nucleases (TALENs), has made it possible to perform precise genetic engineering in many cell types and species. More recently, clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) system has been successfully employed for genome editing. These RNA-guided DNA endonucleases are shown to be more efficient and flexible than CDNs and hold great potential for applications in both biological studies and medicine. Here, we review the progress that has been made for all three genome editing technologies in modifying both cells and model organisms, compare important aspects of each approach, and summarize the applications of these tools in disease modeling and gene therapy. In the end, we discuss future prospects of the field.

A functional polymorphism in MIR196A2 is associated with risk and progression of nasopharyngeal carcinoma in the Chinese population.

BACKGROUND: Genetic variations in microRNAs may alter their processing, expression, and binding to target mRNAs, consequently affecting many cancer-related biological processes. Recently, a polymorphism rs11614913 in MIR196A2 was shown to affect the processing of the precursor microRNA into its mature forms and the repertoire of target mRNAs with which it interacts. We examined whether this polymorphism was relevant to the risk of occurrence or progression of nasopharyngeal carcinoma (NPC) in the Chinese population. METHODS: We genotyped the MIR196A2 rs11614913 in a case-control study of 1084 patients with NPC and 1036 cancer-free controls using the TaqMan assay. The genetic associations with the risk of occurrence and progression of NPC were analyzed by logistic regression. RESULTS: We observed a significantly increased occurrence of NPC associated with the rs11614913 T allele (odds ratio [OR]=1.15, 95% confidence interval [CI]=1.02-1.32, p=0.026) compared with the C allele. The T allele was also significantly associated with the advanced local tumor invasion (T3+T4 vs. T1+T2; OR=1.27, 95% CI=1.04-1.54, p=0.015) and advanced lymph node metastasis (N2+N3 vs. N0+N1; OR=1.23, 95% CI=1.02-1.49, p=0.031) of NPC compared with the C allele. Furthermore, stratified analysis indicated that the increased susceptibility to advanced lymph node metastasis of NPC related to the T allele was more pronounced in patients with a positive family history (N2+N3 vs. N0+N1; p=0.016, test for homogeneity). CONCLUSIONS: Our study suggests that the functional polymorphism rs11614913 in the MIR196A2 gene may contribute to the risk of occurrence and progression of NPC in the Chinese population.

Snail promotes the cell-autonomous generation of Flk1(+) endothelial cells through the repression of the microRNA-200 family.

Expression of the transcription factor Snail is required for normal vasculogenesis in the developing mouse embryo. In addition, tumors expressing Snail have been associated with a more malignant phenotype, with both increased invasive properties and angiogenesis. Although the relationship between Snail and vasculogenesis has been noted, no mechanistic analysis has been elucidated. Here, we show that in addition to inducing an epithelial mesenchymal transition, Snail promotes the cell-autonomous induction of Flk1(+) endothelial cells in an early subset of differentiating mouse embryonic stem (ES) cells. Cells that become Flk1+ in response to Snail have a transcriptional profile specific to Gata6+primitive endoderm, but not the early Nanog+epiblast. We further show that Snail's ability to promote Flk1(+) endothelium depends on fibroblast growth factor signaling as well as the repression of the microRNA-200 (miR-200) family, which directly targets the 3' UTRs of Flk1 and Ets1. Together, our results show that Snail is capable of inducing Flk1+ lineage commitment in a subset of differentiating ES cells through the down-regulation of the miR-200 family. We hypothesize that this mechanism of Snail-induced vasculogenesis may be conserved in both the early developing embryo and malignant cancers.

Functional polymorphism -31C/G in the promoter of BIRC5 gene and risk of nasopharyngeal carcinoma among chinese.

BACKGROUND: Baculoviral inhibitor of apoptosis repeat-containing 5 (BIRC5, also called as survivin) is a member of the inhibitor of apoptosis protein (IAP) family, which plays an important role in the occurrence and progression of cancer. Recently, a polymorphism in the promoter of BIRC5, -31C/G (rs9904341), was shown to influence BIRC5 expression. METHODS: We examined whether the -31C/G was related to the risk of developing nasopharyngeal carcinoma (NPC) in a case-control population from Guangxi province in southern China, which consists of 855 patients with NPC and 1036 controls. This polymorphism was genotyped by TaqMan assay. The genetic associations with the occurrence and progression of NPC were estimated by logistic regression. RESULTS: We observed a statistically significant increased occurrence of NPC associated with the CC genotype (odds ratio [OR], 1.40; 95% confidence interval [CI], 1.13-1.73; P=0.0020) compared with the genotypes containing G allele (CG + GG genotype). However, no significant association was observed for the -31C/G with the severity of NPC (as measured by tumor-node-metastasis staging system). CONCLUSION: Our findings suggest that the functional polymorphism -31C/G in the promoter of BIRC5 gene may play a role in mediating the susceptibility to NPC among Chinese.

Genome-wide association study identifies 1p36.22 as a new susceptibility locus for hepatocellular carcinoma in chronic hepatitis B virus carriers.

To identify susceptibility variants for hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), we conducted a genome-wide association study by genotyping 440,794 SNPs in 355 chronic HBV carriers with HCC and 360 chronic HBV carriers without HCC, all of Chinese ancestry. We identified one intronic SNP (rs17401966) in KIF1B on chromosome 1p36.22 that was highly associated with HBV-related HCC and confirmed this association in five additional independent samples, consisting of 1,962 individuals with HCC, 1,430 control subjects and 159 family trios. Across the six studies, the association with rs17401966 was highly statistically significant (joint odds ratio = 0.61, P = 1.7 x 10(-18)). In addition to KIF1B, the association region tagged two other plausible causative genes, UBE4B and PGD. Our findings provide evidence that the 1p36.22 locus confers susceptibility to HBV-related HCC, and suggest that KIF1B-, UBE4B- or PGD-related pathways might be involved in the pathogenesis of this malignancy.

Mesp1 coordinately regulates cardiovascular fate restriction and epithelial-mesenchymal transition in differentiating ESCs.

Wnt signaling is required for development of mesoderm-derived lineages and expression of transcription factors associated with the primitive streak. In a functional screen, we examined the mesoderm-inducing capacity of transcription factors whose expression was Wnt-dependent in differentiating ESCs. In contrast to many inactive factors, we found that mesoderm posterior 1 (Mesp1) promoted mesoderm development independently of Wnt signaling. Transient Mesp1 expression in ESCs promotes changes associated with epithelial-mesenchymal transition (EMT) and induction of Snai1, consistent with a role in gastrulation. Mesp1 expression also restricted the potential fates derived from ESCs, generating mesoderm progenitors with cardiovascular, but not hematopoietic, potential. Thus, in addition to its effects on EMT, Mesp1 may be capable of generating the recently identified multipotent cardiovascular progenitor from ESCs in vitro.

Development of a microscopy-based assay for protein kinase Czeta activation in human breast cancer cells.

Protein kinase Czeta (PKCzeta) plays a critical role in cancer cell chemotaxis. Upon activation induced by epidermal growth factor (EGF) or chemoattractant SDF-1alpha, PKCzeta redistributes from cytosol to plasma membrane. Based on this property, we developed a rapid cell-based assay for inhibitors of ligand-induced PKCzeta activation. PKCzeta green fluorescent protein (GFP) was transfected into human breast cancer cells, MDA-MB-231, to establish a stable cell line, PKCzeta-GFP/MDA-MB-231. PKCzeta-GFP/MDA-MB-231 maintained phenotypes, such as chemotaxis, adhesion, and cell migration, similar to those of its parental cell line. Therefore it could be used as a representative cancer cell line. EGF induced translocation of PKCzeta-GFP to plasma membrane in a pattern similar to that of endogenous PKCzeta, indicative of activation of PKCzeta Translocation of PKCzeta-GFP could be easily and directly recorded by an inverted fluorescence microscope. Inhibitors of chemotaxis also impaired the translocation of PKCzeta-GFP, which further validated the biological relevance of our assay. Taken together, we have developed a simple, rapid, and reliable assay to detect the ligand-induced activation of PKCzeta in human cancer cells. This assay can be used in screening for inhibitors of PKCzeta activation, which is critically required for cancer cell chemotaxis.