Generation of Mlk3 KO mice by CRISPR/Cas9 and its effect on blood pressure / 生物工程学报

To explore the effect of Mlk3 (mixed lineage kinase 3) deficiency on blood pressure, Mlk3 gene knockout (Mlk3KO) mice were generated. Activities of sgRNAs targeted Mlk3 gene were evaluated by T7 endonuclease I (T7E1) assay. CRISPR/Cas9 mRNA and sgRNA were obtained by in vitro transcription, microinjected into zygote, followed by transferring into a foster mother. Genotyping and DNA sequencing confirmed the deletion of Mlk3 gene. Real- time PCR (RT-PCR), Western blotting or immunofluorescence analysis showed that Mlk3KO mice had an undetectable expression of Mlk3 mRNA or Mlk3 protein. Mlk3KO mice exhibited an elevated systolic blood pressure compared with wild-type mice as measured by tail-cuff system. Immunohistochemistry and Western blotting analysis showed that the phosphorylation of MLC (myosin light chain) was significantly increased in aorta isolated from Mlk3KO mice. Together, Mlk3KO mice was successfully generated by CRISPR/Cas9 system. MLK3 functions in maintaining blood pressure homeostasis by regulating MLC phosphorylation. This study provides an animal model for exploring the mechanism by which Mlk3 protects against the development of hypertension and hypertensive cardiovascular remodeling.

The value of calcification and cystic lesion of CT findings in differentiating pancreatic head ductal carcinoma from mass-forming chronic pancreatitis of the pancreatic head / 实用放射学杂志

Objective To investigate the diagnostic value of calcification and cystic lesion of CT findings in differentiating pancreatic head ductal carcinoma (PHDA)from mass-forming chronic pancreatitis (MFCP)of the pancreatic head.Methods The clinic data and CT findings of 30 cases with PHDA and 24 cases with MFCP of the pancreatic head,which were confirmed by surgery and pathology were analyzed retrospectively.The images were reviewed independently by two expert radiologists with a double-blind method.An independent sample t test and chi-square test were used to compare the data of imaging findings between two groups.Results ① Calcification was found in 14 cases (58.33%)with MFCP and in 3 cases (10%)with PHDA (P＜0.001).The percentage of patchy,punctate and mixed calcification were 28.57% (n=4),14.29% (n=2)and 57.14% (n=8)in MFCP,0% (n=0),66.67% (n=2)and 33.33% (n=1) in PHDA,respectively.② Necrotic cyst was founded in 7 cases (29.17%)with MFCP and 18 cases (60%)with PHDA(P＜0.05). Pseudocysts were demonstrated in 14 cases (58.33%)with MFCP and in 3 cases (10%)with PHDA (P＜0.001).Honeycombed change with tension within or around the lesion were demonstrated only in patients with MFCP.In addition,normal tissue of the pancreas was found within the lesion in 11 cases (45.83%)of MFCP and none in PHDA,which showed significant difference between two groups.Conclusion Mixed calcification and honeycomb with tension of CT findings are of significant value in differentiating PHDA from MFCP of the pancreatic head.