Profiling analysis reveals the potential contribution of long non-coding RNAs to preterm white matter injury

Circ_19038 and lnc-AK016022 synergistically regulate Sirt1 to promote remyelination and alleviate white matter injury in preterm mice

Maternal inflammation can lead to premature birth and fetal brain damage. CircRNA_19038 and lncRNA-AK016022 have been shown to be significantly reduced in brain tissues of preterm mice, while whether they are involved in the regulation of preterm white matter injury remains to be explored. Pregnant mice were intraperitoneally injected with lipopolysaccharide (LPS) to establish a preterm brain injury model. Healthy mice born at term served as controls. Lentivirus-mediated circ_19038 overexpression vector (LV-circ_19038), LV-lnc-AK016022, LV-Sirt1 and LV-sh-Sirt1 were administered to preterm mice through the ventricles. The expression levels of circ_19038, lnc-AK016022 and Sirt1 in the brain tissues of preterm mice were significantly lower than those of full-term healthy mice, and circ_19038 and lnc-AK016022 were co-localized in the brain tissues. Upregulation of circ_19038 or/and lnc-AK016022 promoted remyelination and alleviated white matter structural damage, neuroinflammation, and long-term cognitive and motor deficits in preterm mice, and the combined effect of circ_19038 and lnc-AK016022 showed better results. Primary mouse neuronal cells were isolated to investigate the regulatory effects of circ_19038 and lnc-AK016022 on Sirt1. Circ_19038 and lnc-AK016022 jointly promoted the expression of Sirt1 by adsorbing miR-1b and miR-328, respectively. Moreover, silencing Sirt1 antagonized the beneficial effects of circ_19038 or/and lnc-AK016022 on brain white matter injury in preterm mice. In conclusion, circ_19038 and lnc-AK016022 synergistically regulated Sirt1 expression to promote remyelination and alleviate white matter injury in preterm mice.

Changes in circMyt1l/rno-let-7d-5p/brain-derived neurotrophic factor. A damaged periventricular white matter damage model in neonatal rats

OBJECTIVES

To investigate the function of circMyt1l/rno-let-7d-5p/BDNF in the white matter damage of premature rats.

METHODS

Bioinformatic analysis was used to analyze the differential expression of circMyt1l and its interacting miRNAs and mRNAs in rats with periventricular white matter damage. Rats at postnatal day 3 had their right common carotid artery permanently ligated, and were then exposed for 2 h to 6 % O2, or sham surgery and exposure to normal O2 levels (sham). CircMyt1l and rno-let-7d-5p expression was detected and BDNF protein levels were analyzed at 24, 48, and 72 h post hypoxia-ischemia.

RESULTS

Bioinformatic analysis suggested that circMyt1l, rno-let-7d-5p and BDNF interact. CircMyt1l expression decreased significantly relative to the sham-operated rats (p<0.01) in an exposure time-dependent manner. Contrastingly, rno-let-7d-5p increased significantly relative to the sham-operated rats (p<0.01) in an exposure time dependent manner. BDNF protein levels decreased significantly relative to the sham-operated rats (p<0.05) in an exposure time dependent manner.

CONCLUSIONS

The expression levels of circMyt1l/rno-let-7d-5p/BDNF are interrelated in periventricular white matter damage. Decreased circMyt1l expression of promoted the effect of rno-let-7d-5p and decreased the level of its target, BDNF.

LncRNAs and CircRNAs as Strategies against Pathological Conditions Caused by a Hypoxic/Anoxic State

Brain damage can be induced by oxygen deprivation. It is known that hypoxic or anoxic conditions can lead to changes in the expression levels of non-coding RNAs (ncRNAs), which, in turn, can be related to Central Nervous System (CNS) injuries. Therefore, it could be useful to investigate the involvement of non-coding RNAs (ncRNAs), as well as the underlying mechanisms which are able to modulate them in brain damage induced by hypoxic or anoxic conditions. In this review, we focused on recent research that associates these conditions with long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs). The results of this review demonstrate that the expression of both lncRNAs and circRNAs can be influenced by oxygen deprivation conditions and so they can contribute to inducing damage or providing neuroprotection by affecting specific molecular pathways. Furthermore, several experimental studies have shown that ncRNA activity can be regulated by compounds, thus also modifying their transcriptomic profile and their effects on CNS damages induced by hypoxic/anoxic events.

LncRNA-SNX17 Promotes HTR-8/SVneo Proliferation and Invasion Through miR-517a/IGF-1 in the Placenta of Diabetic Macrosomia

Gestational diabetes mellitus (GDM) has become a worldwide problem in recent years. Macrosomia, a primary consequence of GDM, has short-term and life-long consequences in the offspring of mothers with GDM. Our previous study showed that miR-517a was dysregulated in placenta and plasma of fetal growth restriction through inhibiting invasion of trophoblast and might be closely related with the regulation of birth weight by the placenta. To further investigate the mechanism of miR-517a, we conducted genome-wide microarray profile of lncRNAs. lncRNA-SNX17 was found to be significantly upregulated in the placenta of diabetic macrosomia by qRT-PCR, and the expression of miR-517a and IGF-1 were measured by qRT-PCR and Western blot. Interestingly, significant inverse correlations of the miR-517a with both lncRNA-SNX17 and IGF-1 expression were revealed in the placenta of diabetic macrosomia. Bioinformatic prediction also revealed that both lncRNA-SNX17 and IGF-1 possessed binding sites for miR-517a, which were then confirmed by luciferase report assay. LncRNA-SNX17 overexpression reduced the expression of miR-517a and increased the IGF-1 expression in HTR-8/SVneo human trophoblast cell line and thus enhanced the proliferation of HTR-8/SVneo. The enhancement of HTR-8/SVneo proliferation by lncRNA-SXN17 could be nullified by co-transfection of miR-517a mimics. The data suggested that lncRNA-SNX17 might promote the trophoblast proliferation through miR-517a/IGF-1 pathway and might play a role in the placentation of diabetic macrosomia.

Dissecting the Roles of LncRNAs in the Development of Periventricular White Matter Damage

Long non-coding RNA (LncRNA) has high expression in the brain. Animal studies have shown that lncRNA plays an important role in brain functions and mediates the development of many neurological diseases. However, data on the expression of lncRNAs and the clinical significance in prematurely born infants with diseases such as periventricular white matter damage (PWMD) remains scant. Here, we compared the expression of the lncRNAs in whole blood samples obtained from prematurely born infants with PWMD with samples from prematurely born infants without PWMD. Our data demonstrated differential expression of the lncRNAs between the two groups. Further, we showed that the lncRNAs play important roles in the development of PWMD. Our findings give insights into the functions of the lncRNAs in PWMD and provide evidence for the improvement of diagnostic and treatment strategies in infants with PWMD.

Long noncoding RNA H19 act as a competing endogenous RNA of Let-7g to facilitate IEC-6 cell migration and proliferation via regulating EGF

Intestinal mucosal injury is one of the most significant complications of burns. In our previous study, it was found that autophagy could alleviate burn-induced intestinal injury, but the underlying mechanisms are still unclear. Irregular expression of long noncoding RNAs (lncRNAs) is present in many diseases, including burns. However, the relationship between lncRNAs and intestinal mucosal injury requires further elucidation. In this study, we established a burn mice model and detected the expression level of autophagy-related proteins. Then, H19 content after autophagy intervention was tested in vitro and in vivo. The interaction of H19 with Let-7g and that of Let-7g with epidermal growth factor (EGF) were verified by dual-luciferase reporter assays. We found that the expression of the autophagy-associated proteins LC3-II and Beclin-1 was raised in the intestinal tract of the burn mice model. Similarly, the transfection of H19 raised autophagy levels. H19 was elevated after autophagy intervention in vitro and in vivo. H19 overexpression was able to promote IEC-6 cell migration and proliferation. Let-7g was suppressed by the overexpression of H19 and the combination of Let-7g mimic was able to abolish the physiological effect of H19. Moreover, the suppression of Let-7g increased the expression of EGF protein, which heightened IEC-6 cell migration and proliferation. Besides this, dual-luciferase assays revealed that Let-7g was a direct target of H19 as well as the EGF gene. Taken together, autophagy-mediated H19 increases in mouse intestinal tract after severe burn and functions as a sponge to Let-7g to regulate EGF, which suggests that H19 serves as a potential therapeutic target and biomarker for intestinal mucosal injury after burns.