Recently, clustered regularly interspaced palindromic repeats (CRISPR)-Cas9 derived editing tools had significantly improved our ability to make desired changes in the genome. Wild-type Cas9 protein ...recognizes the target genomic loci and induced local double strand breaks (DSBs) in the guidance of small RNA molecule. In mammalian cells, the DSBs are mainly repaired by endogenous non-homologous end joining (NHEJ) pathway, which is error prone and results in the formation of indels. The indels can be harnessed to interrupt gene coding sequences or regulation elements. The DSBs can also be fixed by homology directed repair (HDR) pathway to introduce desired changes, such as base substitution and fragment insertion, when proper donor templates are provided, albeit in a less efficient manner. Besides making DSBs, Cas9 protein can be mutated to serve as a DNA binding platform to recruit functional modulators to the target loci, performing local transcriptional regulation, epigenetic remolding, base editing or prime editing. These Cas9 derived editing tools, especially base editors and prime editors, can introduce precise changes into the target loci at a single-base resolution and in an efficient and irreversible manner. Such features make these editing tools very promising for therapeutic applications. This review focuses on the evolution and mechanisms of CRISPR-Cas9 derived editing tools and their applications in the field of gene therapy.
Vocal learning is a complex acquired social behavior that has been found only in very few animals. The process of animal vocal learning requires the participation of sensorimotor function. By ...accepting external auditory input and cooperating with repeated vocal imitation practice, a stable pattern of vocal information output is eventually formed. In parallel evolutionary branches, humans and songbirds share striking similarities in vocal learning behavior. For example, their vocal learning processes involve auditory feedback, complex syntactic structures, and sensitive periods. At the same time, they have evolved the hierarchical structure of special forebrain regions related to vocal motor control and vocal learning, which are organized and closely associated to the auditory cortex. By comparing the location, function, genome, and transcriptome of vocal learning-related brain regions, it was confirmed that songbird singing and human language-related neural control pathways have certain analogy. These common characteristics make songbirds an ideal animal model for studying the neural mechanisms of vocal learning behavior. The neural process of human language learning may be explained through similar neural mechanisms, and it can provide important insights for the treatment of language disorders.
Recently, CRISPR-based techniques have significantly improved our ability to make desired changes and regulations in various genomes. Among them, targeted base editing is one of the most powerful ...techniques in making precise genomic editing. Base editing enabled the irreversible conversion of a specific single DNA base, from C to T or and from A to G, in desired genomic loci. This technique has important implications in the study of human genetic diseases, considering that many of them resulted from point mutations. More importantly, the high efficiency of these editing tools also provided great promise in clinical applications. In this review, we discuss the recent progress and challenges of base editing tools.
We present a base editing system, in which base editors are attached to different sites of sgRNA scaffold (sgBE). Each independent sgBE has its own specific editing pattern for a given target site. ...Among tested sgBEs, sgBE-SL4, in which deaminase is attached to the last stem-loop of sgRNA, yields the highest editing efficiency in the window several nucleotides next to the one edited by BE3. sgBE enables the simultaneous editing of adenine and cytosine. Finally, in order to facilitate in vivo base editing, we extend our sgBE system to an AAV-compatible Cas9, SaCas9 (Staphylococcus aureus), and observe robust base editing.
Recent advances in CRISPR-Cas9 techniques, especially the discovery of base and prime editing, have significantly improved our ability to make precise changes in the genome. We hypothesized that ...modulating certain endogenous pathway cells could improve the action of those editing tools in mammalian cells. We established a reporter system in which a small fragment was integrated into the genome by prime editing (PE). With this system, we screened an in-house small-molecule library and identified a group of histone deacetylase inhibitors (HDACi) increasing prime editing. We also found that HDACi increased the efficiency of both cytosine base editing (CBE) and adenine base editing (ABE). Moreover, HDACi increased the purity of cytosine base editor products, which was accompanied by an upregulation of the acetylation of uracil DNA glycosylase (UNG) and UNG inhibitor (UGI) and an enhancement of their interaction. In summary, our work demonstrated that HDACi improves Cas9-mediated prime editing and base editing.
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CRISPR-Cas9-derived prime editors and base editors are powerful tools in precise genome editing. We demonstrate that HDAC inhibition increases the efficiency of prime editors and base editors, which advances our understanding of regulating endogenous mechanisms to improve genome editing.
Family doctors in rural China are the main force for primary health care, but the workforce has not been well stabilized in recent years. Surface acting is an emotional labor strategy with a ...disparity between inner feelings and emotional displays, provoking negative effects such as emotional exhaustion, occupational commitment reduction, and, consequently, increasing turnover rate. With the Conservation of Resources theory, this study explores how the surface acting of rural family doctors affects turnover intention through emotional exhaustion and investigates what role occupational commitment plays in this relationship.
With a valid response rate of 93.89%, 953 valid data were collected by an anonymous self-administered questionnaire survey in December 2021 in Shandong Province, China. Cronbach's Alpha and confirmatory factor analysis (CFA) were used to estimate reliability and construct validity, respectively. The PROCESS macro in SPSS was performed to analyze the mediating and moderated mediation effects of surface acting, emotional exhaustion, occupational commitment, and turnover intention.
Reliability and validity indicated that the measurement instruments were acceptable. Surface acting had a direct positive effect on turnover intention (β = 0.481, 95% CI 0.420, 0.543). Emotional exhaustion partially mediated the effect of surface acting on turnover intention (indirect effect: 0.214, 95% CI 0.175, 0.256). Occupational commitment moderated the effect of emotional exhaustion on turnover intention (β = - 0.065, 95% CI - 0.111, - 0.019), and moderated the indirect effect of surface acting on turnover intention via emotional exhaustion (index of moderated mediation: - 0.035).
Emotional exhaustion partially mediates the relationship between surface acting and turnover intention among family doctors in rural China, and occupational commitment moderates the direct effect of emotional exhaustion on turnover intention and further moderates the mediating effect. Policymakers should pay more attention to the effects of emotional labor and emotional resource depletion on the stability of rural health human resources.
Cisplatin-based concurrent chemoradiotherapy has been identified as the primary and standard treatment for locally advanced nasopharyngeal carcinoma (NPC). However, the side effects of cisplatin ...affect the compliance to therapy. Thus, the search for a platinum-based substitute for NPC has always been a research focus. However, there is a variability in the efficacy of different platinum-based chemotherapies in the treatment of NPC. We performed a meta-analysis to compare the efficacy and safety of cisplatin-based regimens and other platinum-based derivatives (carboplatin, nedaplatin, and lobaplatin) for locally advanced NPC.
PubMed, EMBASE, Cochrane Library, Web of Science, and ClinicalTrials.gov were systematically searched for all potentially eligible clinical trials as of February 15, 2022. The pooled hazard ratios, risk ratio, and 95% confidence interval were calculated using Review Manager Software version 5.4.
A total of 1,907 patients with locally advanced NPC were eligible from the 1,265 retrieved records. This systematic review included eight articles, six of which were randomized controlled clinical trials. There was no significant difference in the 3- and 5-year overall survival, progression-free survival, distant metastasis-free survival, and locoregional relapse-free survival between cisplatin-based chemotherapy and other platinum-based chemotherapy. Severe acute hematological side effects (≥ grade 3) during treatment, such as neutropenia, leukopenia, and thrombocytopenia, were equivalent in both groups. However, the incidence of anemia was higher in patients receiving other platinum-based chemotherapies. The risk of nausea, vomiting and weight loss was higher in the cisplatin group; however, there was no significant difference in the other non-hematological and late side effects between the two groups.
Other types of platinum-based chemotherapies are as effective as cisplatin-based chemotherapy in the treatment of locally advanced NPC, thus acting as potential alternatives to cisplatin. Further studies providing high-level evidence are needed.
There is little literature on the validity of kurtosis-adjusted noise energy metrics in human studies. Therefore, this study aimed to validate the application of cumulative noise exposure (CNE) ...adjusted by kurtosis in evaluating occupational hearing loss associated with non-Gaussian noise among manufacturing workers.
A cross-sectional survey was conducted on 1,558 manufacturing workers exposed to noise from five industries to collect noise exposure and hearing loss data. Both CNE and kurtosis-adjusted CNE (CNE') were collapsed into 2-dB(A)∙year bins, and the mean noise-induced permanent threshold shifts at 3, 4, and 6 kHz (NIPTS
) in each bin were calculated. The contributions of CNE and CNE' to noise-induced hearing loss (NIHL) were compared using the multiple linear regression. The degree of overlap of two linear regression equations (i.e., between CNE' and NIPTS
for non-Gaussian noise and between CNE and NIPTS
for Gaussian noise) was used to evaluate the validity of the CNE' using a stratified analysis based on age and sex.
Multiple linear regression models showed that after kurtosis adjustment, the standardized regression coefficient of CNE increased from 0.230 to 0.255, and
increased from 0.147 to 0.153. The linear relationship between NIPTS
and CNE' or CNE showed that the regression line of non-Gaussian noise was closer to that of Gaussian noise when using CNE' than using CNE. The mean difference in NIPTS
between the equations of non-Gaussian noise and Gaussian noise was significantly reduced from 4.32 to 1.63 dB HL after kurtosis adjustment (
= 12.00,
< 0.001). Through a stratified analysis, these significant decreases were observed in male and female workers, and workers aged ≥30 years old.
As a noise exposure metric combining noise energy and temporal characteristics, the kurtosis-adjusted-CNE metric was more effective than CNE alone in assessing occupational hearing loss among manufacturing workers in non-Gaussian noise environment. However, more studies are needed to verify the validity of the kurtosis-adjusted-CNE metric.
Pneumoconiosis is the most prevalent occupational disease and displays different patterns in each province of China. Clarifying specific incidence patterns and temporal trends in Zhejiang Province ...can help provide valuable information on the prevention of pneumoconiosis.
Annual reports of pneumoconiosis for Zhejiang Province from 2006 to 2020 were extracted from the National Occupational Disease and Occupational Health Information Monitoring System. The information of cases included regions, diagnosis ages, genders, exposure durations, pneumoconiosis categories and stages, the first year of exposure, enterprise industries, scales and ownerships.
Totally 6037 new cases of pneumoconiosis were reported between 2006 and 2020, which increased at first and then gradually declined since 2013. Among all pneumoconiosis cases, silicosis accounted for the majority (72.17%). Most of the cases occurred in small-scale and domestic-funded enterprises, which accounted for 71.75% and 96.97%, respectively. When analyzing the industry distribution, the cases were mainly concentrated in mining (37.12%), manufacturing (31.11%) and 'public administration and social organization' (23.94%) industry. The average diagnosis age among the pneumoconiosis cases was 55.44 years, and the median exposure duration was 11.00 years. Significantly older diagnosis age and longer exposure duration were found in females, coal workers' pneumoconiosis cases, cases with higher stages, cases with the first year of dust exposure earlier and cases from large-scale companies. In regional distribution, the top three cities reporting the most pneumoconiosis cases in Zhejiang Province were Taizhou, Quzhou and Hangzhou.
The current situation of pneumoconiosis in Zhejiang Province was still serious, and government should further strengthen the surveillance of occupational diseases and supervision of enterprises. Moreover, publicity and education regarding pneumoconiosis should be carried out to raise awareness of dust exposure risk and associated health consequences.
Let α>−1/2, we establish a Bohr phenomenon for differential operatorsΔα=(1−|x|2){1−|x|24Δ+α∑j=1nxj∂∂xj+α(n2−1−α)}. We also obtain the Bohr radius and its asymptotic properties in this setting. The ...Bohr radius equals the unique solution in (0,1) of an equation related to hypergeometric functions.
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