Crispr-Based Editing of Human Pluripotent Stem Cells for Disease Modeling.

The CRISPR system, as an effective genome editing technology, has been extensively utilized for the construction of disease models in human pluripotent stem cells. Establishment of a gene mutant or knockout stem cell line typically relies on Cas nuclease-generated double-stranded DNA breaks and exogenous templates, which can produce uncontrollable editing byproducts and toxicity. The recently developed adenine base editors (ABE) have greatly facilitated related research by introducing A/T > G/C mutations in the coding regions or splitting sites (AG-GT) of genes, enabling mutant gene knock-in or knock-out without introducing DNA breaks. In this study, we edit the AG bases in exons anterior to achieve gene knockout via the ABE8e-SpRY, which recognizes most expanded protospacer adjacent motif to target the genome. Except for gene-knockout, ABE8e-SpRY can also efficiently establish disease-related A/T-to-G/C variation cell lines by targeting coding sequences. The method we generated is simple and time-saving, and it only takes two weeks to obtain the desired cell line. This protocol provides operating instructions step-by-step for constructing knockout and point mutation cell lines.

Bi-ligand-fabricated CdS quantum dots to photo-induce aqueous-phase aldol condensation for biomass-derived carbonyl compounds.

CdS QDs were fabricated using bi-ligands 11-sulfanylundecanoic acid and proline for photo-induced aqueous-phase aldol condensation of biomass-derived furfural compounds and ketones, and they displayed acceptable selectivity, activity and recycling properties for generation of a wide range of products with diverse applications. This work facilitates understanding the molecular-level design concepts of semiconductor photocatalysts.

In Vivo Base Editing of Scn5a Rescues Type 3 Long QT Syndrome in Mice.

BACKGROUND: Pathogenic variants in SCN5A can result in long QT syndrome type 3, a life-threatening genetic disease. Adenine base editors can convert targeted A T base pairs to G C base pairs, offering a promising tool to correct pathogenic variants. METHODS: We generated a long QT syndrome type 3 mouse model by introducing the T1307M pathogenic variant into the Scn5a gene. The adenine base editor was split into 2 smaller parts and delivered into the heart by adeno-associated virus serotype 9 (AAV9-ABEmax) to correct the T1307M pathogenic variant. RESULTS: Both homozygous and heterozygous T1307M mice showed significant QT prolongation. Carbachol administration induced Torsades de Pointes or ventricular tachycardia for homozygous T1307M mice (20%) but not for heterozygous or wild-type mice. A single intraperitoneal injection of AAV9-ABEmax at postnatal day 14 resulted in up to 99.20% Scn5a transcripts corrected in T1307M mice. Scn5a mRNA correction rate >60% eliminated QT prolongation; Scn5a mRNA correction rate <60% alleviated QT prolongation. Partial Scn5a correction resulted in cardiomyocytes heterogeneity, which did not induce severe arrhythmias. We did not detect off-target DNA or RNA editing events in ABEmax-treated mouse hearts. CONCLUSIONS: These findings show that in vivo AAV9-ABEmax editing can correct the variant Scn5a allele, effectively ameliorating arrhythmia phenotypes. Our results offer a proof of concept for the treatment of hereditary arrhythmias.

Generation of a human embryonic stem cell line (WAe009-A-78) carrying homozygous TBX18 knockout.

T-Box Transcription Factor 18 is a member of the T-box family, encoding TBX18 protein. As a transcriptional repressor, it related to developmental processes of a majority of tissues and organs and plays crucial part in the embryonic development of sinoatrial node. Using an episomal vector-based CRISPR/Cas9 system, we have established a homozygous TBX18 knockout (TBX18-KO) human embryonic stem cell (hESC) line. This newly TBX18-/- hESC line display normal pluripotency, morphology, karyotype and trilineage differentiating capacity. This cell line may provide a powerful tool to investigate the role of TBX18 gene in sinoatrial node development in future.

Glycyrrhizin Inhibits PEDV Infection and Proinflammatory Cytokine Secretion via the HMGB1/TLR4-MAPK p38 Pathway.

Our previous study showed that glycyrrhizin (GLY) inhibited porcine epidemic diarrhea virus (PEDV) infection, but the mechanisms of GLY anti-PEDV action remain unclear. In this study, we focused on the anti-PEDV and anti-proinflammatory cytokine secretion mechanisms of GLY. We found that PEDV infection had no effect on toll-like receptor 4 (TLR4) protein and mRNA levels, but that TLR4 regulated PEDV infection and the mRNA levels of proinflammatory cytokines. In addition, we demonstrated that TLR4 regulated p38 phosphorylation but not extracellular regulated protein kinases1/2 (Erk1/2) and c-Jun N-terminal kinases (JNK) phosphorylation, and that GLY inhibited p38 phosphorylation but not Erk1/2 and JNK phosphorylation. Therefore, we further explored the relationship between high mobility group box-1 (HMGB1) and p38. We demonstrated that inhibition of HMGB1 using an antibody, mutation, or knockdown decreased p38 phosphorylation. Thus, HMGB1 participated in activation of p38 through TLR4. Collectively, our data indicated that GLY inhibited PEDV infection and decreased proinflammatory cytokine secretion via the HMGB1/TLR4-mitogen-activated protein kinase (MAPK) p38 pathway.

The loop rogue wave solutions for the Wadati-Konno-Ichikawa equation.

The first-order rogue wave solution with two arbitrary parameters of the Wadati-Konno-Ichikawa equation is generated based on the Darboux transformation and inverse hodograph transformation. The analyticity of first-order rogue wave solution is studied. A simple analysis shows that the parameter that denotes the amplitude of background wave plays an important role in controlling the analyticity of rogue wave solution. In particular, the rogue wave solution displays a loop-type profile when it is singular, and the general features of loop rogue waves are discussed in detail.

Theoretical and experimental evidence of non-symmetric doubly localized rogue waves.

We present determinant expressions for vector rogue wave (RW) solutions of the Manakov system, a two-component coupled nonlinear Schrödinger (NLS) equation. As a special case, we generate a family of exact and non-symmetric RW solutions of the NLS equation up to third order, localized in both space and time. The derived non-symmetric doubly localized second-order solution is generated experimentally in a water wave flume for deep-water conditions. Experimental results, confirming the characteristic non-symmetric pattern of the solution, are in very good agreement with theory as well as with numerical simulations, based on the modified NLS equation, known to model accurately the dynamics of weakly nonlinear wave packets in deep water.

Surgical treatment of Budd-Chiari syndrome: analysis of 221 cases.

BACKGROUND: Budd-Chiari syndrome (B-CS) refers to post-hepatic portal hypertension and/or inferior vena cava hypertension caused by obstruction of blood flow at the portal cardinal hepatic vein. The treatments of B-CS include operations on pathological membrane lesions, shunting and combined operations. Studies have shown that China, Japan, India and South Africa have a high incidence of B-CS. In China, the Yellow River Basin in Henan, Shandong, Jiangsu and Anhui Provinces also have a high incidence, around 10 per 100 000. METHODS: The clinical data of 221 B-CS patients were analyzed retrospectively. We focused on pathological types, surgical methods, effectiveness and complications of treatment, and follow-up. RESULTS: Based on imaging findings such as color ultrasonography, angiography or magnetic resonance angiography, the 221 patients were divided into 3 types (five subtypes): type Ia (72 patients), type Ib (20), type II (72), type IIIa (33), and type IIIb (24). Surgical procedures included balloon membranotomy with or without stent (65 patients), improved splenopneumopexy (18), radical resection of membrane and thrombus (17), inferior vena cava bypass [29, with cavocaval transflow (13) and cavoatrial transflow (16)], mesocaval shunt (41), splenocaval shunt (25), splenoatrial shunt (12), splenojugular shunt (6), and combined methods (8). The complication rate was 9.05% (20/221) and the perioperative death rate was 2.26% (5/221). All of the patients were followed up from 6 months to 5 years. The success rate was 84.6% (187/221), and the recurrence rate was 8.9% (9/101) and 13.5% (13/96) after 1- and 5-year follow-up, respectively. CONCLUSION: The rational choice of surgical treatment based on B-CS pathological typing may increase the success rate and decrease the recurrence.