Value of serum PCSK9 for evaluating the severity in patients with type 2 diabetes mellitus and atherosclerosis

Objective:To study the value of serum PCSK9 for evaluating the severity in patients with type 2 diabetes mellitus and atherosclerosis. Methods:Type 2 diabetic patients with carotid atherosclerosis who were treated in our hospital between May 2014 and September 2016 were selected as group A (n=69), type 2 diabetic patients without carotid atherosclerosis were selected as group B (n=79) and healthy subjects were selected as group C (n=55). Serum levels of SPCSK9, lipid metabolism indexes and oxidative stress indexes of three groups of subjects were detected. Results:Serum proprotein convertase subtilisin kexin 9 (PCSK9), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), apolipoprotein B (ApoB), CyPA, paraoxonase-1 (PON-1), PON-3, malondialdehyde (MDA) and 8-iso-prostaglandin F-2α(8-iso-PGF2α) levels of group A and group B were significantly higher than those of group C (P<0.05) while high-density lipoprotein cholesterol (HDL-C) and apolipoprotein AI (ApoAI) levels were significantly lower than those of group C (P<0.05);serum PCSK9, TG, TC, LDL-C, ApoB, CyPA, PON-1, PON-3, MDA and 8-iso-PGF2αlevels of group A were significantly higher than those of group B (P<0.05) while HDL-C and ApoAI levels were significantly lower than those of group B (P<0.05);serum TG, TC, LDL-C, ApoB, CyPA, PON-1, PON-3, MDA and 8-iso-PGF2αlevels of high PCSK9 level subgroup in group A were significantly higher than those of low PCSK9 level subgroup (P<0.05) while HDL-C and ApoAI levels were significantly lower than those of low PCSK9 level subgroup (P<0.05). Conclusions:Abnormally elevated serum PCSK9 can affect lipid metabolism and enhance oxidative stress in patients with type 2 diabetes mellitus and atherosclerosis.

AGO_18b negatively regulates determinacy of spikelet meristems on the tassel central spike in maize

The maize tassel represents an indeterminate male inflorescence. The number of primordia that a given inflorescence meristem produces is related to its determinacy, i.e., capacity for continued meristem activity.Transcription factors(TFs) controlling determinacy in tassel axillary meristems are well studied in maize, and small RNAs are known to influence tassel development by repressing targets, including tassel-related TFs. As core components of the RNA-inducible silence complex(RISC),Argonaute(AGO) proteins are required for small RNAmediated repression. Here, we characterized the biological function of AGO8b, a tassel-enriched AGO. The abundance of AGO8b transcripts gradually increased during tassel development from inception to gametogenesis and were enriched in the inflorescence meristem and axillary meristems of the tassel. Repressing AGO8b expression resulted in more spikelets, which contributed to a longer central spike of the tassel. Additionally, the transcripts of several HD-ZIP Ⅲ TFs that were canonical targets of micro RNA66(miR66) accumulated in the AGO8b repressed lines. We propose that AGO8b is a negative regulator of the determinacy of inflorescence and axillary meristems, and that it acts by interacting with the miR66-HD-ZIP Ⅲ TF regulatory pathway.