A novel CRISPR/Cas9-hLacI donor adapting system for dsDNA-templated gene editing / 生物工程学报

During the gene editing process mediated by CRISPR/Cas9, precise genome editing and gene knock-in can be achieved by the homologous recombination of double-stranded DNA (dsDNA) donor template. However, the low-efficiency of homologous recombination in eukaryotic cells hampers the development and application of this gene editing strategy. Here, we developed a novel CRISPR/Cas9-hLacI donor adapting system (DAS) to enhance the dsDNA-templated gene editing, taking the advantage of the specific binding of the LacI repressor protein and the LacO operator sequence derived for the Escherichia coli lactose operon. The codon-humanized LacI gene was fused as an adaptor to the Streptococcus pyogenes Cas9 (SpCas9) and Staphylococcus lugdunensis Cas9 (SlugCas9-HF) genes, and the LacO operator sequence was used as the aptamer and linked to the dsDNA donor template by PCR. The Cas9 nuclease activity after the fusion and the homology-directed repair (HDR) efficiency of the LacO-linked dsDNA template were firstly examined using surrogate reporter assays with the corresponding reporter vectors. The CRISPR/Cas9-hLacI DASs mediated genome precise editing were further checked, and we achieved a high efficiency up to 30.5% of precise editing at the VEGFA locus in HEK293T cells by using the CRISPR/SlugCas9-hLacI DAS. In summary, we developed a novel CRISPR/Cas9-hLacI DAS for dsDNA-templated gene editing, which enriches the CRISPR/Cas9-derived gene editing techniques and provides a novel tool for animal molecular design breeding researches.

Serum levels of soluble programmed death-1 and soluble programmed death-ligand 1 in chronic hepatitis B patients with clinical cure and their clinical features / 临床肝胆病杂志

Objective To investigate the serum levels of soluble programmed death-1 (sPD-1) and soluble programmed death-ligand 1 (sPD-L1) in chronic hepatitis B (CHB) patients with clinical cure, the correlation between programmed death-1 (PD-1) and lymphocytes by flow cytometry, and the recovery of hepatitis B virus (HBV)-specific immunity. Methods A total of 26 CHB patients with clinical cure, 26 treatment-naïve CHB patients, and 26 healthy controls who were diagnosed at the outpatient service of Peking University First Hospital from January to May of 2022 were enrolled, and related clinical data and peripheral blood samples were collected. ELISA was used to measure the serum levels of sPD-1 and sPD-L1, and flow cytometry was used to measure the expression of PD-1 in peripheral blood lymphocytes. CHB patients with clinical cure were compared with the treatment-naïve CHB patients and the healthy controls. The Kruskal-Wallis H test was used for comparison of non-normally distributed continuous data between three groups, and the chi-square test was used for comparison of categorical data between groups. The Pearson correlation analysis or the Spearman correlation analysis was used to investigate the correlation between two continuous variables. Results For the 26 CHB patients with clinical cure, the mean time of antiviral therapy was 8.33 years, with entecavir as the antiviral drug. The CHB patients with clinical cure had significantly higher levels of sPD-1 and sPD-L1 than the healthy controls ( P 0.05). Conclusion The serum levels of sPD-1 and sPD-L1 in treatment-naïve CHB patients are mainly associated with exhausted CD8 + T cells in peripheral blood, while there is no significant correlation between serum sPD-1/sPD-L1 and exhausted CD8 + T cells in peripheral blood in CHB patients with clinical cure.

Influencing factors for direct-acting antiviral therapy failure in treatment of hepatitis C / 临床肝胆病杂志

Objective To investigate the influencing factors for direct-acting antiviral agent (DAA) therapy failure in the treatment of hepatitis C by comparing baseline clinical data and resistance-associated substitution (RAS) in sequencing data between the patients with HCV RNA reactivation after DAA therapy and the patients with successful DAA treatment. Methods A total of 13 patients from multiple centers who failed DAA therapy from November 2019 to October 2021 were enrolled as treatment failure group, and sequencing was performed for their positive serum samples. A total of 51 patients with successful DAA treatment were enrolled as control group, and baseline clinical data and sequencing results were compared between the treatment failure group and the control group. The Mann-Whitney U test was used for comparison of non-normally distributed continuous data between groups, and the chi-square test was used for comparison of categorical data between groups; univariate and multivariate logistic regression analyses were performed to calculate odds ratio ( OR ) and investigate the influencing factors for treatment failure. Results All 12 patients with complete treatment data experienced recurrence within 1 year after the end of medication. The male patients with treatment failure had significantly higher baseline total bilirubin, direct bilirubin, and creatinine than their female counterparts ( Z =-2.517, -2.440, and -2.132, P =0.010, 0.010, and 0.038), and the patients with an age of ≤55 years ( OR =5.152, 95% confidence interval [ CI ]: 1.116-23.790, P =0.036) or genotype 3b ( OR =9.726, 95% CI : 1.325-71.398, P =0.025) had a higher probability of treatment failure. There were differences in the incidence rates of major RAS mutations on three gene fragments between the treatment failure group and the treatment success group, and the common RAS mutations detected in the treatment failure group were not detected in the treatment success group. Conclusion Age, genotype, and RAS in serum virus gene sequence are influencing factors for DAA treatment failure.

Virological response to direct-acting antiviral therapy and changes in liver fibrosis indices in chronic hepatitis C patients with different alanine aminotransferase and aspartate aminotransferase levels in a real-world setting / 临床肝胆病杂志

ObjectiveTo investigate the virologic response to direct-acting antiviral (DAA) therapy and the changes in liver stiffness measurement (LSM), fibrosis-4 (FIB-4), and aspartate aminotransferase-to-platelet ratio index (APRI) after treatment in chronic hepatitis C (CHC) patients with different alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels at baseline in a real-world setting. MethodsCHC patients who attended the outpatient service of Department of Infectious Diseases, Peking University First Hospital, from December 2017 to May 2020 were enrolled, and virologic response rate was calculated. The Wilcoxon rank-sum test was used to compare LSM, FIB-4, and APRI between groups at baseline and at 12 weeks after treatment, and the chi-square test was used for comparison of categorical data between groups. ResultsA total of 48 CHC patients were enrolled, among whom 33.3% had abnormal ALT or AST at baseline. Among these patients, the virologic response rate was 85.4% at week 4 of treatment and 100% at the end of treatment and at 12, 24, and 48 weeks after treatment, and there were significant changes from baseline to 12 weeks after treatment in LSM ［6.1 (51-12.4) kPa vs 8.6 (5.7-16.9) kPa, Z=-1.676, P=0.043］ and APRI ［0.24(0.19-0.48) vs 0.42(0.23-1.17), Z=-2.050, P=0027］. From baseline to 12 weeks after treatment, the patients with abnormal ALT or AST at baseline had significant changes in LSM ［89(5.6-13.1) kPa vs 14.4(8.0-28.2) kPa, Z=-1.679, P=0.047］ and APRI ［0.44(0.25-0.50) vs 1.29(0.99-2.09), Z=-3.427, P=0.001］. ConclusionCHC patients achieve a high sustained virologic response rate after DAA therapy, and the patients with abnormal ALT or AST at baseline tend to have more significant improvements in LSM and APRI than those without such abnormality.

Pathogenesis and clinical prevention and treatment of osteoporosis in patients with hepatitis B / 临床肝胆病杂志

With the improvement in clinical treatment and the increase in life expectancy, the incidence rate of osteoporosis is gradually increasing in patients with hepatitis B. However, the specific mechanism of different stages of hepatitis B on osteoporosis is still complex and remains unclear, and there are few studies on the prevention and treatment of osteoporosis in patients with hepatitis B. This article reviews the pathogenesis and clinical prevention and treatment of osteoporosis in patients with hepatitis B, in order to provide better guidance for clinical management and treatment.

Research progress in characterizing multiple-target mechanisms of novel anti-Alzheimer's dimers / 中国药理学通报

Alzheimer's disease ( AD ) is a complex disease caused by environmental and genetic factors. Therefore, one-drug-multiple-target compounds represent the most promising pharmacological approaches to preventing and treating this dis-ease. We have previously designed and synthesized bis( n)-Cog-nitin, novel anti-Alzheimer's dimers derived from tacrine. Bis ( n)-Cognitin have been proven to act on multiple important AD targets, including acetylcholinesterase, β-secretase, N-methyl-D-aspartic acid receptor and neuronal nitric oxide synthase, con-currently. Moreover, Bis(n)-Cognitin could inhibit β-amyloid-induced neurotoxicity, decrease glutamate-induced excitotoxici-ty, reduce oxidative stress, improve learning and memory, and protect against neuronal apoptosis in various in vitro and in vivo models, suggesting that bis ( n )-Cognitin are potential anti-AD drug candidates.