Objective: To investigate the role of miR-19a/b in myocardial ischemia reperfusion injury (R/I) with its clinical significance. Methods: Our research included in 2 parts. Part 1: in H9c2 cells. miR-19a/b expression in H9c2 cells with 10 h hypoxia and 2 h re-oxygenation was detected by real-time PCR, miR-19a/b potential target gene was assessed by luciferase reporter activity assay. Part 2: in natural person. Control group,n=40 healthy subjects and AMI (acute myocardial infarction) group,n=40 relevant patients. Peripheral blood levels of miR-19a/b were detected as Part 1, cTnI were measured by chemiluminescence immune analysis and CK-MB were assessed by immune inhibition method. Results: Part 1: Compared with normal H9c2 cells, miR-19a/b expressions were increased 5.876 times and 2.761 times in H9c2 cells with 10 h hypoxia and 2 h re-oxygenation, bothP<0.01. With respectively transfected miR-19a/b mimic and inhibitor, miR-19a/b expression was up-regulated and down-regulated respectively. miR-19a/b and chromosome-10 deleted phosphatase, tensing homolog gene (PTEN) had the targeting effect. With up-regulated miR-19a/b expression, PTEN level was decreased and with down-regulated miR-19a/b expression, PTEN level was increased. Part 2: Compared with Control group, AMI group had elevated blood level of miR-19a/b,P<0.01. In AMI patients, miR-19a/b was increasing at 0-3 h of chest pain and reaching the peak at 6-12 h; CK-MB enzyme activity and cTnI content were elevating at 2-6 h of onset and reaching the peak at 24 h. Conclusion: miR-19a/b expression was up-regulated by myocardial ischemia reperfusion in H9c2 cells, PTEN was the potential target gene of miR-19a/b. Circulating miR-19a/b might be used as a new non-invasive biological marker for myocardial ischemia R/I diagnosis.

Non-conventional yeasts such as Yarrowia lipolytica, Pichia pastoris, Kluyveromyces marxianus, Rhodosporidium toruloides and Hansenula polymorpha have proven to be efficient cell factories in producing a variety of natural products due to their wide substrate utilization spectrum, strong tolerance to environmental stresses and other merits. With the development of synthetic biology and gene editing technology, metabolic engineering tools and strategies for non-conventional yeasts are expanding. This review introduces the physiological characteristics, tool development and current application of several representative non-conventional yeasts, and summarizes the metabolic engineering strategies commonly used in the improvement of natural products biosynthesis. We also discuss the strengths and weaknesses of non-conventional yeasts as natural products cell factories at current stage, and prospects future research and development trends.
Yeasts/genetics* ; Yarrowia/metabolism* ; Gene Editing ; Metabolic Engineering