Biology subjects

Yan, W. X.

Publications and source records attributed to Yan, W. X..

3 recordsLinked to original sources

bioRxiv2020

Effects of Sodium tanshinone IIA sulfonate on H9C2 cardiomyocyte injury induced by sodium arsenite

Arsenic is a grade I human carcinogen that can cause kinds of damage to the body. The heart is one of the main target organs of arsenic damage, but the preventive and curative measures underlying arsenic poisoning are not clear. To investigate the effect of tanshinone IIA sulfonate (STS) on the injury of H9C2 cardiomyocytes induced by NaAsO2,H9C2 cardiomyocyteswere divided into four groups where control group with general medium, arsenic (As) group received sodium arsenite (NaAsO2)-containing general medium, STS pretreatment+As group and finally the STS alone group. Compared with the control group, different concentrations of STS had no significant effect on the cell viability (n = 6, P > 0.05); Compared with the control group, there was no significant change in the viability of cells treated with arsenic for 12 h after STS pretreatment for 6 h (n = 6, P > 0.05),the viability of cells treated with NaAsO2 alone was decreased(n = 6, P < 0.05);Compared with the control group, the cell viability was decreased after STS pretreatment for 12h and arsenic for 24h, the cell viability of NaAsO2 group was also decreased, the viability of NaAsO2 cells was lower than that of STS pretreated for 12h with NaAsO2 for 24h(n=6,p<0.05).The content of Caspase 3/7 in the NaAsO2 group was higher than that in the STS and NaAsO2 group and the Control group and STS group after 12h, the differences were statistically significant(n=6,p<0.05).After STS pretreatment for 12h and NaAsO2 for 24 h, there was no significant difference in Caspase 8 content between NaAsO2 group and other groups(n=6,P>0.05) As a result, Sodium tanshinone IIA sulfonate can attenuate the injury of H9C2 cardiomyocytes induced by sodium arsenite.

cell biology↗

bioRxiv2016

Engineered Cpf1 Enzymes with Altered PAM Specificities

The RNA-guided endonuclease Cpf1 is a promising tool for genome editing in eukaryotic cells1-5. Compared to other genome editing platforms, Cpf1 offers distinct advantages, such as the ability to easily target multiple genes simultaneously3, as well as low rates of off-target activity4, 5. However, the Acidaminococcus sp. BV3L6 Cpf1 (AsCpf1), which has been successfully harnessed for genome editing, can only robustly cleave target sites preceded by a TTTV protospacer adjacent motif (PAM), which may limit its practical utility. To address this limitation, we used a structure- guided saturation mutagenesis screen to increase the targeting range of Cpf1. We engineered two variants of AsCpf1 with the mutations S542R/K607R and S542R/K548V/N552R that can cleave target sites with TYCV/CCCC and TATV PAMs, respectively, with enhanced activities in vitro and in human cells. Genome-wide assessment of off-target activity indicated that these variants retain a high level of DNA targeting specificity, which can be further improved by introducing mutations in non-PAM-interacting domains. Together, these variants increase the targeting range of AsCpf1 to one cleavage site for every ~8.7 bp in non-repetitive regions of the human genome, providing a useful addition to the CRISPR/Cas genome engineering toolbox.

synthetic biology↗

bioRxiv2016

BLISS: quantitative and versatile genome-wide profiling of DNA breaks in situ

We present a method for genome-wide DNA double-strand Breaks (DSBs) Labeling In Situ and Sequencing (BLISS) which, compared to existing methods, introduces several key features: 1) high efficiency and low input requirement by in situ DSB labeling in cells or tissue sections directly on a solid surface; 2) easy scalability by performing in situ reactions in multi-well plates; 3) high sensitivity by linearly amplifying tagged DSBs using in vitro transcription; and 4) accurate DSB quantification and control of PCR biases by using unique molecular identifiers. We demonstrate the ability to use BLISS to quantify natural and drug-induced DSBs in low-input samples of cancer cells, primary mouse embryonic stem cells, and mouse liver tissue sections. Finally, we applied BLISS to compare the specificity of CRISPR-associated RNA-guided endonucleases Cas9 and Cpf1, and found that Cpf1 has higher specificity than Cas9. These results establish BLISS as a versatile, sensitive, and efficient method for genome-wide DSB mapping in many applications.

molecular biology↗