MicroRNAs and hypoxia inducible factor have extensive and important biological functions, both of them play an important regulatory role in angiogenesis. The interaction between them has an important significance for the profound understanding of the regulatory mechanism of angiogenesis. This article mainly summarizes the mutual regulation of microRNA and hypoxia inducible factor and its effect on angiogenesis in recent years.

Objective To investigate the dynamic changes of serum insulin-like growth factor-1 (IGF-1) in acute traumatic brain injury (TBI) as well as their correlations with the initial severity of TBI and prognosis.Methods A total of 229 patients with acute TBI admitted from September 2014 to June 2016 were retrospectively studied.Patients were further classified as mild TBI group (GCS 13-15 points),moderate TBI group (GCS 9-12 points) and severe TBI group (GCS 3-8 points) according to Glasgow coma score (GCS).The control group consisted of 30 healthy subjects.The prognosis was evaluated by using Glasgow outcome scale (GOS) at 6 months after TBI.The IGF-1 levels were further tested at days 1,3,5,7 and 14 and their correlations with the initial GCS and GOS at 6 months after injury were evaluated.Results (1) The serum IGF-1 levels of mild,moderate and severe TBI group at all time points were significantly lower than those of the control group (P ＜ 0.05);the serum IGF-1 levels of severe and moderate TBI groups at all time points after injury were significantly lower than those of the mild TBI group (P ＜0.05);the serum IGF-1 levels of the severe group at days 1,3,5 and 7 d after injury were lower than those of the moderate TBI group (P＜0.05).(2) IGF-1 levels were significantly different between the two groups (P ＜ 0.05) at different time points during the follow-up of 6 months.(3)IGF-1 levels were positively correlated with both GCS and GOS at the acute stage of TBI and sub-acute stage following TBI (P ＜ 0.05).Conclusion The dynamic changes of serum IGF-1 levels in patients with acute TBI are related to both initial severity of TBI and the neurological outcomes and can be used as a reliable biomarker for early severity assessment and prognostic prediction of TBI.