ABSTRACT
In the past decade, many long noncoding RNAs (lncRNAs) have been identified and their in vitro functions defined, although in some cases their functions in vivo remain less clear. Moreover, unlike nuclear lncRNAs, the roles of cytoplasmic lncRNAs are less defined. Here, using a gene trapping approach in mouse embryonic stem cells, we identify Caren (short for cardiomyocyte-enriched noncoding transcript), a cytoplasmic lncRNA abundantly expressed in cardiomyocytes. Caren maintains cardiac function under pathological stress by inactivating the ataxia telangiectasia mutated (ATM)-DNA damage response (DDR) pathway and activating mitochondrial bioenergetics. The presence of Caren transcripts does not alter expression of nearby (cis) genes but rather decreases translation of an mRNA transcribed from a distant gene encoding histidine triad nucleotide-binding protein 1 (Hint1), which activates the ATM-DDR pathway and reduces mitochondrial respiratory capacity in cardiomyocytes. Therefore, the cytoplasmic lncRNA Caren functions in cardioprotection by regulating translation of a distant gene and maintaining cardiomyocyte homeostasis.
Subject(s)
DNA Damage/physiology , Heart Failure/metabolism , Organelle Biogenesis , RNA, Long Noncoding/metabolism , Animals , Cell Nucleus , Energy Metabolism , Fibroblasts , Heart Failure/pathology , Homeostasis , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Mitochondria/metabolism , Mouse Embryonic Stem Cells , Myocytes, Cardiac/metabolism , Nerve Tissue Proteins/genetics , Nerve Tissue Proteins/metabolism , RNA, Long Noncoding/genetics , RNA, Messenger/metabolismABSTRACT
INTRODUCTION: Evidence on the reliability of using procalcitonin (PCT) and high-sensitivity C-reactive protein (hs-CRP) as diagnostic markers for early-onset neonatal bacterial infections is still insufficient because of their physiological elevation during the early neonatal period. This study aimed to assess the respiratory influence of serum PCT and hs-CRP levels and evaluate their predictive value for bacterial infections during the first 72 h of life in preterm neonates. METHODS: The preterm neonates enrolled in this single-center retrospective cohort study were categorized into 3 groups: reference, infection-unlikely respiratory failure, and probable bacterial infection; their serum PCT and hs-CRP levels were assessed. Subsequently, age-specific 95th percentile curves were plotted and the median and cutoff PCT and hs-CRP levels for predicting bacterial infections at birth and 7-18, 19-36, and 37-72 h after birth were determined. Moreover, the analysis of PCT and hs-CRP with a neonatal sequential organ failure assessment (nSOFA) score was performed in very low birth weight neonates. RESULTS: Serum PCT levels were influenced by respiratory failure. A significant difference was found in the median PCT and hs-CRP levels among the 3 groups at each time point. PCT sensitivities for predicting bacterial infection were slightly higher than those of hs-CRP in each time frame during the first 72 h of life. In both PCT and hs-CRP, there was no significant difference between infants with nSOFA scores of >4 and those with nSOFA scores of ≤4. DISCUSSION/CONCLUSION: Age-specific evaluation showed that PCT has better predictive value than hs-CRP for early-onset bacterial infections in preterm neonates.
