Maximizing CRISPRi efficacy and accessibility with dual-sgRNA libraries and optimal effectors.

CRISPR interference (CRISPRi) enables programmable, reversible, and titratable repression of gene expression (knockdown) in mammalian cells. Initial CRISPRi-mediated genetic screens have showcased the potential to address basic questions in cell biology, genetics, and biotechnology, but wider deployment of CRISPRi screening has been constrained by the large size of single guide RNA (sgRNA) libraries and challenges in generating cell models with consistent CRISPRi-mediated knockdown. Here, we present next-generation CRISPRi sgRNA libraries and effector expression constructs that enable strong and consistent knockdown across mammalian cell models. First, we combine empirical sgRNA selection with a dual-sgRNA library design to generate an ultra-compact (1-3 elements per gene), highly active CRISPRi sgRNA library. Next, we compare CRISPRi effectors to show that the recently published Zim3-dCas9 provides an excellent balance between strong on-target knockdown and minimal non-specific effects on cell growth or the transcriptome. Finally, we engineer a suite of cell lines with stable expression of Zim3-dCas9 and robust on-target knockdown. Our results and publicly available reagents establish best practices for CRISPRi genetic screening.

Prevalence and risk factors of metabolic syndrome among adults in Hainan Province / 中国热带医学

@#Abstract: Objective　This study aims to explore the prevalence and risk factors of metabolic syndrome (MS) among the adults in Hainan Province, and to provide scientific basis for MS prevention and control. Methods　A multi-stage cluster random sampling method was applied to select 3 690 permanent residents aged 18 years and above in Hainan Province. The survey was conducted by trained investigators using household appointments and centralized surveys. A questionnaire survey, physical measurement, and laboratory examination were conducted after the collection of blood samples. The processed samples were then tested by a quality-controlled laboratory. Finally, we analysed the prevalence of metabolic syndrome (MS) and its relationship with population characteristics and health-related behaviors. Results　The crude prevalence of MS in the population aged 18 and above in Hainan province was 19.46% and the standardized prevalence was 13.21%, with a higher rate in urban areas (22.21%) than in rural areas (18.13%). The prevalence of MS increased with age (P<0.001), and there were significant differences in MS prevalence among different marital and occupational statuses (P<0.01). Logistic regression results indicated that the age groups of 40-<50 years (OR=2.986, 95%CI:1.355-6.580), 50-<60 years (OR=3.739, 95%CI: 1.715-8.151), 60-<70 years (OR=3.890, 95%CI: 1.769-8.556), 70 years and above (OR=3.927, 95%CI: 1.758-8.771), technical, transportation and production personnel (OR=1.579, 95%CI: 1.033-2.412), retired (OR=1.788, 95%CI: 1.415-2.259), unemployed (OR=1.503, 95%CI: 1.044-2.165), smoking cessation (OR=1.582, 95%CI: 1.162-2.154), insufficient intake of fruits and vegetables (OR=1.196, 95%CI: 1.005-1.422), and insufficient physical activity (OR=1.437, 95%CI: 1.155-1.787) were all associated with the prevalence of MS. Among the investigated subjects, 30.22% of them had one abnormal component, with hyperglycemia being the highest (54.44%); 24.25% of them had two abnormal components, with "hyperglycemia + hypertension" being the highest (33.30%); and 19.46% had three or more components, with "overweight/obesity + hyperglycemia + hypertension" being the highest (24.79%). Conclusions　The prevalence of MS in Hainan Province is on the rise, and effective lifestyle intervention measures are needed to reduce the risk of MS.

Analysis of the monitoring results of death causes of permanent residents in Hainan, 2014-2020 / 中国热带医学

@#Abstract: Objective　To understand the general situation of death causes of permanent residents in Hainan Province from 2014 to 2020, analyze the causes of death, and provide scientific basis for the formulation of policies related to healthy Hainan. Methods The Hainan Provincial Population Death Information Registration and Management System was used to report data, and the death information of permanent residents in Hainan Province from 2014 to 2020 was obtained. Excel 2010 and SPSS 26.0 software were applied to perform statistical analysis related to the indicators including crude mortality rate, standardized mortality rate, ranking of causes of death, and composition ratio; the standardized mortality rate was calculated based on the data of the 2010 National Census Data. Results　From 2014 to 2020, the average annual resident population of Hainan Province was 9 175 300, and average annual resident population at each of the eight monitoringp oints is 297 100， anaverage of 83 878 cumulative deaths were reported, the annual total mortality rate was 504.09/100 000, the standard mortality rate was 618.69/100 000. The standardized mortality rates of male and female were 806.18/100 000 and 444.36/100 000 respectively (P<0.01). The mortality rate of all age groups showed that the crude mortality rate of 0~<1 years old group showed a decreasing trend with the passage of time, and the crude mortality rate was significantly higher than that of other age groups. From the age of 20, with the increase of age, the overall crude mortality rate of residents keeps increasing. The crude death rate increases rapidly after the age of 65, and peaks especially after the age of 85. The leading causes of death were circulatory diseases, tumors and respiratory diseases. From 2014 to 2020, the mortality rate of circulatory diseases and tumors, the two main causes of death, was more than 100/100 000. Conclusion　Chronic non-communicable diseases are still the first cause of death among permanent residents in Hainan Province. Targeted intervention and treatment of chronic non-communicable diseases is beneficial to reduce their mortality.