Combined prediction of miR-210 and miR-374a for severity and prognosis of hypoxic-ischemic encephalopathy

miR-374 family is a key regulator of chronic primary pain onset

Introduction

Chronic primary pain conditions (CPPCs) are linked to catecholamine activation of peripheral adrenergic receptors. Yet, catecholamine-dependent epigenetic mechanisms, such as microRNA (miRNA) regulation of mRNA transcripts, remain largely unknown.

Objectives

We sought to identify RNA species correlated with case status in 3 pain cohorts, to validate RNAs found to be dysregulated in a mouse model of CPPC onset, and to directly test the role of adrenergic receptors in miRNA regulation. Furthermore, we tested antinociceptive effects of miR-374 overexpression.

Methods

We used RNA-seq and quantitative reverse transcription polymerase chain reaction to measure RNA expression in 3 pain cohorts. Next, we validated identified RNAs with quantitative reverse transcription polymerase chain reaction in a mouse model of CPPC onset, measuring expression in plasma, peripheral (adipose, muscle, dorsal root ganglia [DRG]), and central (spinal cord) tissues. Then, we stimulated adrenergic receptors in primary adipocyte and DRG cultures to directly test regulation of microRNAs by adrenergic signaling. Furthermore, we used in vitro calcium imaging to measure the antinociceptive effects of miR-374 overexpression.

Results

We found that one miRNA family, miR-374, was downregulated in the plasma of individuals with temporomandibular disorder, fibromyalgia syndrome, or widespread pain following a motor vehicle collision. miR-374 was also downregulated in plasma, white adipose tissue, and spinal cord from mice with multisite mechanical sensitivity. miR-374 downregulation in plasma and spinal cord was female specific. Norepinephrine stimulation of primary adipocytes, but not DRG, led to decreased miR-374 expression. Furthermore, we identified tissue-specific and sex-specific changes in the expression of predicted miR-374 mRNA targets, including known (HIF1A, NUMB, TGFBR2) and new (ATXN7, CRK-II) pain targets. Finally, we demonstrated that miR-374 overexpression in DRG neurons reduced capsaicin-induced nociceptor activity.

Conclusions

Downregulation of miR-374 occurs between adrenergic receptor activation and mechanical hypersensitivity, and its adipocyte source implicates adipose signaling in nociception. Further study of miR-374 may inform therapeutic strategies for the millions worldwide who experience CPPCs.

Searching molecular biomarkers correlating with BSID-III at 24 months in infants with neonatal hypoxic-ischemic encephalopathy

An early prediction of outcomes of neonatal hypoxic-ischemic encephalopathy (NE) is of key importance in reducing neonatal mortality and morbidity. The objectives were (i) to analyze the characteristics of miRNA expression and metabolic patterns of neonates with NE and (ii) to assess their predictive performance for neurodevelopmental outcomes. Plasma samples from moderate/severe NE patients (N = 92) of the HYPOTOP study were collected before, during, and after therapeutic hypothermia (TH) and compared to a control group (healthy term infants). The expression of miRNAs and concentrations of metabolites (hypoxia-related and energy, steroid, and tryptophan metabolisms) were analyzed. Neurodevelopmental outcomes were evaluated at 24 months postnatal age using Bayley Scales of Infant Development, ed. III, BSID-III. Differences in miRNA and metabolic profiles were found between NE vs. control infants, abnormal (i.e., mildly and moderately abnormal and severe) vs. normal, and severe vs. non-severe (i.e., normal and mildly and moderately abnormal) BSID-III. 4-Androstene-3,17-dione, testosterone, betaine, xanthine, and lactate were suitable for BSID-III outcome prediction (receiver operating characteristic areas under the curve (AUCs) ≥ 0.6), as well as 68 miRNAs (AUCs of 0.5-0.9). Significant partial correlations of xanthine and betaine levels and the expression of several miRNAs with BSID-III sub-scales were found. Conclusion: We have identified metabolites/miRNAs that might be useful to support the prediction of middle-term neurodevelopmental outcomes of NE. What is known and what is new: • The early prediction of outcomes of neonatal hypoxic-ischemic encephalopathy (NE) is of key importance in reducing neonatal mortality and morbidity. • Alterations of the metabolome and miRNAs had been observed in NE. • We performed miRNA sequencing and quantified selected metabolites (i.e., lactate, pyruvate, ketone bodies, Krebs cycle intermediates, tryptophan pathway, hypoxia-related metabolites, and steroids) by GC- and LC-MS. • Specific miRNAs and metabolites that allow prediction of middle-term neurodevelopmental outcomes of newborns with NE undergoing hypothermia treatment were identified.

MicroRNAs as biomarkers of brain injury in neonatal encephalopathy: an observational cohort study

Neonatal Encephalopathy (NE) is a major cause of lifelong disability and neurological complications in affected infants. Identifying novel diagnostic biomarkers in this population may assist in predicting MRI injury and differentiate neonates with NE from those with low-cord pH or healthy neonates and may help clinicians make real-time decisions. To compare the microRNA (miRNA) profiles between neonates with NE, healthy controls, and neonates with low cord pH. Moreover, miRNA concentrations were compared to brain injury severity in neonates with NE. This is a retrospective analysis of miRNA profiles from select samples in the biorepository and data registry at the University of Florida Health Gainesville. The Firefly miRNA assay was used to screen a total of 65 neurological miRNA targets in neonates with NE (n = 36), low cord pH (n = 18) and healthy controls (n = 37). Multivariate statistical techniques, including principal component analysis and orthogonal partial least squares discriminant analysis, and miRNA Enrichment Analysis and Annotation were used to identify miRNA markers and their pathobiological relevance. A set of 10 highly influential miRNAs were identified, which were significantly upregulated in the NE group compared to healthy controls. Of these, miR-323a-3p and mir-30e-5p displayed the highest fold change in expression levels. Moreover, miR-34c-5p, miR-491-5p, and miR-346 were significantly higher in the NE group compared to the low cord pH group. Furthermore, several miRNAs were identified that can differentiate between no/mild and moderate/severe injury in the NE group as measured by MRI. MiRNAs represent promising diagnostic and prognostic tools for improving the management of NE.

A case-control comparison of acute-phase peripheral blood gene expression in participants diagnosed with minor ischaemic stroke or stroke mimics

BACKGROUND

Past studies suggest that there are changes in peripheral blood cell gene expression in response to ischaemic stroke; however, the specific changes which occur during the acute phase are poorly characterised. The current study aimed to identify peripheral blood cell genes specifically associated with the early response to ischaemic stroke using whole blood samples collected from participants diagnosed with ischaemic stroke (n = 29) or stroke mimics (n = 27) following emergency presentation to hospital. Long non-coding RNA (lncRNA), mRNA and micro-RNA (miRNA) abundance was measured by RNA-seq, and the consensusDE package was used to identify genes which were differentially expressed between groups. A sensitivity analysis excluding two participants with metastatic disease was also conducted.

RESULTS

The mean time from symptom onset to blood collection was 2.6 h. Most strokes were mild (median NIH stroke scale score 2.0). Ten mRNAs (all down-regulated in samples provided by patients experiencing ischaemic stroke) and 30 miRNAs (14 over-expressed and 16 under-expressed in participants with ischaemic stroke) were significantly different between groups in the whole cohort and sensitivity analyses. No significant over-representation of gene ontology categories by the differentially expressed genes was observed. Random forest analysis suggested a panel of differentially expressed genes (ADGRG7 and miRNAs 96, 532, 6766, 6798 and 6804) as potential ischaemic stroke biomarkers, although modelling analyses demonstrated that these genes had poor diagnostic performance.

CONCLUSIONS

This study provides evidence suggesting that the early response to minor ischaemic stroke is predominantly reflected by changes in the expression of miRNAs in peripheral blood cells. Further work in independent cohorts particularly in patients with more severe stroke is needed to validate these findings and investigate their clinical relevance.

MicroRNA therapeutic targets in neonatal hypoxic-ischemic brain injury: a narrative review

Neonatal hypoxic-ischemic brain injury (HIBI) is a devastating injury resulting from impaired blood flow and oxygen delivery to the brain at or around the time of birth. Despite the use of therapeutic hypothermia, more than one in four survivors suffer from major developmental disabilities-an indication of the critical need for more effective therapies. MicroRNAs (miRNA) have the potential to act as biomarkers and/or therapeutic targets in neonatal HIBI as a step toward improving outcomes in this high-risk population. This review summarizes the current literature around the use of cord blood and postnatal circulating blood miRNA expression for diagnosis or prognosis in human infants with hypoxic-ischemic encephalopathy, as well as animal studies assessing endogenous brain miRNA expression and potential for therapeutic targeting of miRNA expression for neuroprotection. Ultimately, the lack of knowledge regarding brain specificity of circulating miRNAs and the temporal variability in expression currently limit the use of miRNAs as biomarkers. However, given their broad effect profile, ease of administration, and small size allowing for effective blood-brain barrier crossing, miRNAs represent promising therapeutic targets for improving brain injury and reducing developmental impairments in neonates after HIBI. IMPACT: The high morbidity and mortality of neonatal hypoxic-ischemic brain injury (HIBI) despite current therapies demonstrates a need for developing more sensitive biomarkers and superior therapeutic options. MicroRNAs have been evaluated both as biomarkers and therapeutic options after neonatal HIBI. The limited knowledge regarding brain specificity of circulating microRNAs and temporal variability in expression currently limit the use of microRNAs as biomarkers. Future studies comparing the neuroprotective effects of modulating microRNA expression must consider temporal changes in the endogenous expression to determine appropriate timing of therapy, while also optimizing techniques for delivery.

Circ_0007706 downregulation ameliorates neonatal hypoxic ischemic encephalopathy via regulating the miR-579-3p/TRAF6 axis

BACKGROUND

Neonatal hypoxic ischemic encephalopathy (HIE) is a main factor of neonatal death and permanent neurologic deficit. This study sought to investigate the functional role of hsa_circ_0007706 (circ_0007706) in modulating neonatal HIE.

METHODS

In vitro HIE cell model was established in hBMVECs under the condition of oxygen‑glucose deprivation/reperfusion (OGD/R) treatment. qRT-PCR analysis was utilized for detecting the level of circ_0007706, microRNA-579-3p (miR-579-3p) and TNF receptor-associated factor 6 (TRAF6). RNase R treatment and Oligo (dT) ₁₈ primers were employed to verify the features of circ_0007706, and nucleocytoplasmic separation was conducted for determining the location of circ_0007706. CCK-8 assay, EdU assay, and flow cytometry were carried out to measure cell proliferation and apoptosis, respectively. The protein expression of Bax, Bcl-2 and TRAF6 was detected using western blot. Meanwhile, the levels of the pro-inflammatory factors were determined via ELISA. SOD activity and MDA level were assessed via the respective kits. Besides, dual-luciferase reporter assay and RNA pull-down were used to identify the association between miR-579-3p and circ_0007706 or TRAF6.

RESULTS

Circ_0007706 was elevated in HIE newborns and OGD/R cell model. Knockdown of circ_0007706 greatly alleviated OGD/R-induced injury, inflammatory response and oxidative stress. We found that miR-579-3p was a direct target of circ_0007706, and miR-579-3p inhibitor could reverse the impact of circ_0007706 knockdown on OGD/R-caused cell damage in hBMVECs. In addition, miR-579-3p directly interacted with TRAF6, and the protective effects of miR-579-3p on OGD/R-induced injury in hBMVECs were harbored by TRAF6 overexpression. Our data indicated that circ_0007706 knockdown could downregulate the expression of TRAF6 by sponging miR-579-3p in OGD/R-treated hBMVECs.

CONCLUSION

This study demonstrated that circ_0007706 knockdown assuaged HIE-induced injury by decreasing TRAF6 expression via targeting miR-579-3p.

Diagnostic and Therapeutic Roles of the "Omics" in Hypoxic-Ischemic Encephalopathy in Neonates

Perinatal asphyxia and neonatal encephalopathy remain major causes of neonatal mortality, despite the improved availability of diagnostic and therapeutic tools, contributing to neurological and intellectual disabilities worldwide. An approach using a combination of clinical data, neuroimaging, and biochemical parameters is the current strategy towards the improved diagnosis and prognosis of the outcome in neonatal hypoxic-ischemic encephalopathy (HIE) using bioengineering methods. Traditional biomarkers are of little use in this multifactorial and variable phenotype-presenting clinical condition. Novel systems of biology-based "omics" approaches (genomics, transcriptome proteomics, and metabolomics) may help to identify biomarkers associated with brain and other tissue injuries, predicting the disease severity in HIE. Biomarker studies using omics technologies will likely be a key feature of future neuroprotective treatment methods and will help to assess the successful treatment and long-term efficacy of the intervention. This article reviews the roles of different omics as biomarkers of HIE and outlines the existing knowledge of our current understanding of the clinical use of different omics molecules as novel neonatal brain injury biomarkers, which may lead to improved interventions related to the diagnostic and therapeutic aspects of HIE.

Prognostic neurobiomarkers in neonatal encephalopathy

Therapeutic hypothermia is now standard-care for infants with moderate-severe neonatal encephalopathy (NE), and improves brain damage on neuroimaging, and neurodevelopmental outcomes. Critically, for effective neuroprotection, hypothermia should be started within 6 h from birth. There is compelling evidence to suggest that a proportion of infants with mild NE have material risk of developing brain damage and poor outcomes. This cohort is increasingly being offered therapeutic hypothermia, despite lack of trial evidence for its benefit. In current practice, infants need to be diagnosed within 6 h of birth for therapeutic treatment, compared to retrospective NE grading in the pre-hypothermia era. This presents challenges as NE is a dynamic brain disorder that can worsen or resolve over time. Neurological symptoms of NE can be difficult to discern in the first few hours after birth, and confounded by analgesics and anesthetic treatment. Using current enrolment criteria, a significant number of infants with NE that would benefit from hypothermia are not treated, and vice versa, infants are receiving mild hypothermia when its benefit will be limited. Better biomarkers are needed to further improve management and treatment of these neonates. In the present review, we examine the latest research, and highlight a central limitation of most current biomarkers: that their predictive value is consistently greatest after most neuroprotective therapies are no longer effective.

Gingerol ameliorates neuronal damage induced by hypoxia-reoxygenation via the miR-210/brain-derived neurotrophic factor axis

The specific mechanism of gingerol in cerebral ischemia remains unknown. A neuroprotective function for miR-210 in cerebral ischemia has been identified. The brain-derived neurotrophic factor (BDNF)-mediated signaling pathway protects against cerebral ischemic injury. This investigation aimed to determine whether gingerol plays a neuroprotective role in cerebral ischemia via the miR-210/BDNF axis. N2a cells subjected to 10 h of hypoxia and 4 h of reoxygenation were treated with 5, 10, or 20 μmol/L gingerol. The levels of viability, apoptosis, and proteins in N2a cells were determined using MTT assays, flow cytometry, and western blotting, respectively. The binding relationship between BDNF and miR-210 was studied using a dual luciferase reporter assay. The expression levels of miR-210 and BDNF were determined using qPCR. Gingerol repressed the increase in apoptosis and decrease in viability observed in response to hypoxia/reoxygenation. Gingerol increased Bcl-2, BDNF, and TrkB levels and reduced Bax and cleaved caspase 3 levels after hypoxia/reoxygenation. Gingerol evoked decreased expression of miR-210. Inhibition of miR-210 resulted in increased viability and reduced apoptosis along with increased levels of Bcl-2, BDNF, and TrkB and reduced levels of Bax and cleaved caspase 3 after hypoxia/reoxygenation. Additionally, the miR-210 mimic reversed changes induced by gingerol. The cotransfection of the miR-210 mimic and wild type BDNF led to decreased luciferase activity. BDNF was negatively regulated by miR-210. BDNF siRNA reversed these changes evoked by miR-210 inhibition. Gingerol ameliorated hypoxia/reoxygenation-stimulated neuronal damage by regulating the miR-210/BDNF axis, indicating that gingerol is worthy of further application in cerebral ischemia therapy.

Cord blood microRNA-376c and microRNA-1268a as biomarkers for neonatal hypoxic-ischaemic encephalopathy: a diagnostic accuracy study

Background

Hypoxic-ischaemic encephalopathy (HIE) is one of the most common causes of morbidity and mortality among neonates. There is a critical need for non-invasive novel biomarkers to detect HIE early, predict its outcomes and monitor its progression. We conducted this observational study to assess the relative expression of miRNA-376c and miRNA-1268a in cord blood as potential diagnostic and prognostic biomarkers for HIE.

Methods

A total of 100 neonates divided into two independent groups were included. The case group included 50 neonates with HIE, while the control group included 50 matched healthy neonates. Relative expressions of miRNA-376c and miRNA-1268a were measured in whole cord blood at birth using real-time PCR.

Results

Compared with the control group, patients with HIE had a significantly lower median level of miRNA-376c (0.168, IQR=0.011–0.411 vs 1, IQR=0.80–1.20) and a higher median level of miRNA-1268a (13.46, IQR=2.7–22.8 vs 1, IQR=0.4–1.6). Comparing neonates with HIE who survived versus those who did not survive, no statistically significant difference between the groups in terms of miRNA-376c and miRNA-1268a (p=0.124 and p=0.279) was elicited. Our diagnostic analysis showed that, at 0.90 points, miRNA-376c has a sensitivity and a specificity of 88% and 68.40%, with an area under the curve of 84%. At 2.70 points, miRNA-1268a has a sensitivity and a specificity of 76% and 100%, with an area under the curve of 96%.

Conclusion

The relative expression of miRNA-376c and miRNA-1268a was altered in the cord blood of neonates with HIE. In addition, they have moderate diagnostic accuracy in detecting HIE.

Neuronal let-7b-5p acts through the Hippo-YAP pathway in neonatal encephalopathy

Despite increasing knowledge on microRNAs, their role in the pathogenesis of neonatal encephalopathy remains to be elucidated. Herein, we identify let-7b-5p as a significant microRNA in neonates with moderate to severe encephalopathy from dried blood spots using next generation sequencing. Validation studies using Reverse Transcription and quantitative Polymerase Chain Reaction on 45 neonates showed that let-7b-5p expression was increased on day 1 in neonates with moderate to severe encephalopathy with unfavourable outcome when compared to those with mild encephalopathy. Mechanistic studies performed on glucose deprived cell cultures and the cerebral cortex of two animal models of perinatal brain injury, namely hypoxic-ischaemic and intrauterine inflammation models confirm that let-7b-5p is associated with the apoptotic Hippo pathway. Significant reduction in neuronal let-7b-5p expression corresponded with activated Hippo pathway, with increased neuronal/nuclear ratio of Yes Associated Protein (YAP) and increased neuronal cleaved caspase-3 expression in both animal models. Similar results were noted for let-7b-5p and YAP expression in glucose-deprived cell cultures. Reduced nuclear YAP with decreased intracellular let-7b-5p correlated with neuronal apoptosis in conditions of metabolic stress. This finding of the Hippo-YAP association with let-7b needs validation in larger cohorts to further our knowledge on let-7b-5p as a biomarker for neonatal encephalopathy.

Using next generation sequencing of dried blood spots and subsequent validation, Ponnusamy et al identify let-7b-5p as an elevated microRNA in neonates with moderate to severe encephalopathy. Using cell culture and murine models of perinatal brain injury they demonstrate that the effects of let-7b-5p are elicited via the Hippo-YAP pathway, which should be validated in large neonate cohorts to expand our understanding of let-7b-5p as a biomarker for neonatal encephalopathy.

MicroRNA-410 serves as a candidate biomarker in hypoxic-ischemic encephalopathy newborns and provides neuroprotection in oxygen-glucose deprivation-injured PC12 and SH-SY5Y cells

BACKGROUND

MicroRNA-410 (miR-410) has been found to be deregulated in neonatal hypoxic-ischemic encephalopathy (HIE). However, the clinical significance and biological function of miR-410 remain largely elusive. This study aims to investigate the expression and diagnostic performance of miR-410 in HIE newborns, and explores the neuroprotective effect of miR-410 in an oxygen-glucose deprivation (OGD)-induced cell injury model.

METHODS

Expression of miR-410 was examined using quantitative real-time PCR, and its diagnostic performance was evaluated using a receiver operating characteristic analysis. We used OGD-injured PC12 and SH-SY5Y cells to construct an in vitro HIE model. The effect of miR-410 on OGD-induced cell injury was analyzed by assessing cell viability and apoptosis. Enzyme-linked immunosorbent assay was used to evaluate inflammation in cell model. A target gene was assessed according to the luciferase reporter assay.

RESULTS

Serum miR-410 expression was significantly decreased in HIE newborns and OGD-injured cell model. The reduced miR-410 expression served as a biomarker for the diagnosis and progression of HIE. The OGD-induced impaired cell viability, enhanced cell apoptosis, and activated neuroinflammation were abrogated by the overexpression of miR-140 in both PC12 and SH-SY5S cells. Regarding the mechanisms underlying the function of miR-410, phosphatase and tensin homolog (PTEN) was proposed as a direct target of miR-410.

CONCLUSION

All data revealed that serum downregulated miR-410 in HIE serves as candidate diagnostic biomarker, and that miR-410 exerts a neuroprotective role in OGD-injured cells by improving cell viability and inhibiting cell apoptosis through targeting PTEN.

Intrauterine growth restriction followed by oxygen support uniquely interferes with genetic regulators of myelination

Intrauterine growth restriction (IUGR) and oxygen exposure in isolation and combination adversely affect the developing brain, putting infants at risk for neurodevelopmental disability including cerebral palsy. Rodent models of IUGR and postnatal hyperoxia have demonstrated oligodendroglial injury with subsequent white matter injury (WMI) and motor dysfunction. Here we investigate transcriptomic dysregulation in IUGR with and without hyperoxia exposure to account for the abnormal brain structure and function previously documented. We performed RNA sequencing and analysis using a mouse model of IUGR and found that IUGR, hyperoxia, and the combination of IUGR with hyperoxia (IUGR/hyperoxia) produced distinct changes in gene expression. IUGR in isolation demonstrated the fewest differentially expressed genes compared to control. In contrast, we detected several gene alterations in IUGR/hyperoxia; genes involved in myelination were strikingly downregulated. We also identified changes to specific regulators including TCF7L2, BDNF, SOX2, and DGCR8, through Ingenuity Pathway Analysis, that may contribute to impaired myelination in IUGR/hyperoxia. Our findings show that IUGR with hyperoxia induces unique transcriptional changes in the developing brain. These indicate mechanisms for increased risk for WMI in IUGR infants exposed to oxygen and suggest potential therapeutic targets to improve motor outcomes.Significance StatementThis study demonstrates that perinatal exposures of IUGR and/or postnatal hyperoxia result in distinct transcriptomic changes in the developing brain. In particular, we found that genes involved in normal developmental myelination, myelin maintenance, and remyelination were most dysregulated when IUGR was combined with hyperoxia. Understanding how multiple risk factors lead to WMI is the first step in developing future therapeutic interventions. Additionally, because oxygen exposure is often unavoidable after birth, an understanding of gene perturbations in this setting will increase our awareness of the need for tight control of oxygen use to minimize future motor disability.

Aberrant expression of miR-199a in newborns with hypoxic-ischemic encephalopathy and its diagnostic and prognostic significance when combined with S100B and NSE

Neonatal hypoxic-ischemic encephalopathy (HIE) is a disorder mainly due to asphyxia during the perinatal period, and late diagnosis leads to high mortality. In this study, the expression of microRNA-199a (miR-199a) in HIE newborns was investigated, as well as its clinical significance in HIE diagnosis and prognosis. Circulating levels of S100B and NSE in HIE newborns were measured using enzyme-linked immunosorbent assay, and the expression of miR-199a was analyzed using quantitative real-time PCR. The diagnostic value of miR-199a, S100B and NSE was evaluated using the receiver operating characteristic (ROC) analysis, and their prognostic value was assessed by the evaluation of Gesell intellectual development of the HIE newborns. HIE newborns possessed significantly increased levels of S100B and NSE and decreased miR-199a (all P < 0.01). The Neonatal Behavioral Neurological Assessment (NBNA) score of HIE newborns was negatively correlated with S100B and NSE, while was positively correlated miR-199a. The ROC analysis results showed the diagnostic value of serum miR-199a, and the combined detection of miR-199a, S100B and NSE could obtained the highest diagnostic accuracy in HIE newborns. miR-199a expression was lowest in newborns with severe HIE, and it had diagnostic potential to distinguish HIE cases with different severity. Regarding the prognosis of neonatal HIE, the correlation of miR-199a, S100B, NSE with Gesell intellectual development was found in HIE newborns. The decreased miR-199a in HIE newborns serves as a potential diagnostic biomarker and may help to improve the diagnostic and prognostic value of S100B and NSE in neonatal HIE.

Dysregulation of miR-374a is involved in the progression of diabetic retinopathy and regulates the proliferation and migration of retinal microvascular endothelial cells

Clinical relevance: microRNAs (miRNAs) have been reported to be involved in the progression of various diseases.Background: This study evaluated the expression and clinical value of miR-374a in diabetic retinopathy (DR) patients and analysed the effects of miR-374a on the progression of DR.Methods: Subjects were divided into four groups: healthy control, type 2 diabetes mellitus without DR (NDR), proliferation DR (PDR) and non-proliferation DR (NPDR). Real-time polymerase chain reaction (qRT-PCR) was detected in the serum miR-374a levels of the subjects. The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of miR-374a in DR patients. Pearson correlation was used to analyse the correlation between miRNA and clinical indicators of patients. High glucose (HG) in treatment of human retinal microvascular endothelial cells (HRMECs). The effects of miR-374a on cell proliferation and migration induced by HG were detected.Results: Serum miR-374a was progressively accelerated in patients with NDR, NPDR and PDR than in healthy controls. Moreover, miR-374a can significantly distinguish between NDR and DR patients. Among DR patients, miR-374a can differentiate PDR patients from NPDR patients. Serum miR-374a was positively correlated with diabetes duration, fasting plasma glucose (FPG), glycosylated haemoglobin (HbA1c), and homoeostasis model assessment of insulin resistance (HOMA-IR) in DR patients. HG-induced proliferation and migration of HRMECs was inhibited by reduction of miR-374a.Conclusion: Dysregulation of miR-374a is involved in the progression of DR and serves a regulatory role in retinal, which can be used as a promising diagnostic biomarker for DR.

Brain Development in Infants of Mothers With Gestational Diabetes Mellitus: A Diffusion Tensor Imaging Study

OBJECTIVE

The objective of this study was to investigate clinical neurocognitive performance and microstructural white matter (WM) alterations in infants of mothers with gestational diabetes mellitus (GDM) using diffusion tensor imaging.

MATERIALS AND METHODS

Infants (corrected gestational age, 33.42-36.00 weeks) of mothers with GDM (n = 31) and gestational age- and sex-matched unexposed controls (n = 31) accomplished 3-T diffusion tensor imaging scans and neurocognitive tests. Diffusion tensor imaging measures, mainly referring to fractional anisotropy (FA) values, were compared between 2 groups, and within-group analysis of correlation between FA values and neurocognitive testing outcomes in GDM-exposed infants was conducted subsequently.

RESULTS

Fractional anisotropy was significantly decreased in the splenium of corpus callosum, posterior limb of internal capsule, thalamus in infants of mothers with GDM when compared with controls (P < 0.05), reflecting microstructural WM abnormalities in the GDM group. Decreased FA was associated with worse neurocognitive performance in the exposed group (P < 0.05).

CONCLUSIONS

Individuals of mothers with GDM showed microstructural WM abnormalities in different brain regions, which were significantly related to worse neurocognitive performance. This might reveal that GDM directly insults the brain development of the offspring.

Vof-16 knockout improves the recovery from hypoxic-ischemic brain damage of neonatal rats

Hypoxic-ischemic encephalopathy (HIE) results in high neonatal mortality and severe neurological impairments, and its underlying molecular mechanism underwent extensive investigations. Long non-coding RNA (lncRNA) is considered to be an important regulator on brain development and many neurological diseases. Currently, little is known about the role of Vof-16 (lncRNA) in HIE. We detected the relative expression level of Vof-16 in the cortex and hippocampus of hypoxic-ischemic (HI) models whose successful establishment was verified by TTC staining. Then, Vof-16 knockout rats were generated using the CRISPR/Cas engineering technology to search the specific function of the Vof-16 through a series of behavioral evaluations including Neurological severity scores (NSS), Y-maze test, Morris water maze (MWW) test, open field test, and Rotarod test. The results demonstrated the expression of Vof-16 was substantially up-regulated in the cortex and hippocampus of rats with HI injury. Importantly, Vof-16 knockout facilitated the recovery from long-term HI induced nerve damage and neurobehavioral dysfunctions. In conclusion, this study suggests Vof-16 knockout is a promising treatment target for neonatal HIE.

Body temperature-dependent microRNA expression analysis in rats: rno-miR-374-5p regulates apoptosis in skeletal muscle cells via Mex3B under hypothermia

Forensic diagnosis of fatal hypothermia is considered difficult because there are no specific findings. Accordingly, exploration of novel fatal hypothermia-specific findings is important. To elucidate the molecular mechanism of homeostasis in hypothermia and identify novel molecular markers to inform the diagnosis of fatal hypothermia, we focused on microRNA expression in skeletal muscle, which plays a role in cold-induced thermogenesis in mammals. We generated rat models of mild, moderate, and severe hypothermia, and performed body temperature-dependent microRNA expression analysis of the iliopsoas muscle using microarray and quantitative real-time PCR (qRT-PCR). The results show that rno-miR-374-5p expression was significantly induced only by severe hypothermia. Luciferase reporter assay and qRT-PCR results indicated that Mex3B expression was regulated by rno-miR-374-5p and decreased with decreasing body temperature. Gene ontology analysis indicated the involvement of Mex3B in positive regulation of GTPase activity. siRNA analysis showed that Mex3B directly or indirectly regulated Kras expression in vitro, and significantly changed the expression of apoptosis-related genes and proteins. Collectively, these results indicate that rno-miR-374-5p was activated by a decrease in body temperature, whereby it contributed to cell survival by suppressing Mex3B and activating or inactivating Kras. Thus, rno-miR-374-5p is a potential supporting marker for the diagnosis of fatal hypothermia.

Role of Sirtuin-1 in Neonatal Hypoxic-Ischemic Encephalopathy and Its Underlying Mechanism

BACKGROUND Neonatal hypoxic-ischemic encephalopathy (HIE) is a dreaded disease and one of the leading causes of severe neurological dysfunction in neonates. The present study explored the functions of Sirtuin-1 (SIRT1) in neonatal HIE. MATERIAL AND METHODS A HIE neonatal rat model was generated to determine SIRT1 levels in brain tissues. Cell apoptosis and cell viability were analyzed by flow cytometry and MTT assay. qRT-PCR and Western blot analysis were used to assess gene mRNA and protein levels. Subsequently, the effect of SIRT1 on HIE was investigated in vitro by constructing an oxygen-glucose deprivation (OGD) cell model. RESULTS The effective construction of the HIE rat model was confirmed by the enhanced brain cell apoptosis and the increased expression of HIE-related molecular markers, including S100 calcium-binding protein B (S100B) and neuron-specific enolase (NSE). SIRT1 expression was downregulated in HIE rat brain tissues. These findings indicated that SIRT1 was downregulated in neuronal cells subjected to OGD. In addition, enhanced cell viability and reduced cell apoptosis were observed, suggesting that SIRT1 overexpression relieved OGD-induced neuronal cell injury. Transfection with SIRT1-siRNA further increased OGD-induced neuronal cell injury, evidenced by decreased cell viability and enhanced cell apoptosis. Finally, SIRT1 overexpression significantly downregulated p-p65 protein expression. CONCLUSIONS Our findings revealed that SIRT1 may be a novel and promising therapy target for HIE treatment.

MicroRNA-374 is a potential diagnostic biomarker for atherosclerosis and regulates the proliferation and migration of vascular smooth muscle cells

Background

The occurrence and development of atherosclerosis (AS) are closely related to the abnormality of vascular smooth muscle cells (VSMCs), and multiple microRNAs (miRNAs) have been reported to participate in the pathogenesis of AS. This study explored the expression and clinical value of miR-374 in the serum of AS patients, and analyzed its effect on the proliferation and migration of VSMCs.

Methods

The expression levels of miR-374 in the serum of 102 asymptomatic patients with AS and 89 healthy patients were detected by fluorescence quantitative PCR. The diagnostic value of miR-374 was evaluated through the receiver operating characteristic (ROC) curve. What's more, CCK-8 and Transwell assays were used to analyze the effects of miR-374 on the proliferation and migration of VSMCs.

Results

The expression level of miR-374 in the serum of AS patients was significantly higher than that of the control group. At the same time, the expression of miR-374 in AS patients was positively correlated with carotid intima-media thickness (CIMT). The area under the ROC curve is 0.824. Furthermore, overexpression of miR-374 significantly promoted the proliferation and migration of VSMCs, whereas reducing miR-374 inhibited the proliferation and migration of VSMCs.

Conclusions

The high expression of miR-374 may be a potential diagnostic marker for AS, and overexpression of miR-374 may play a role in AS by promoting the proliferation and migration of VSMCs.

Temporally Altered miRNA Expression in a Piglet Model of Hypoxic Ischemic Brain Injury

Hypoxic ischemic encephalopathy (HIE) is the most frequent cause of acquired infant brain injury. Early, clinically relevant biomarkers are required to allow timely application of therapeutic interventions. We previously reported early alterations in several microRNAs (miRNA) in umbilical cord blood at birth in infants with HIE. However, the exact timing of these alterations is unknown. Here, we report serial changes in six circulating, cross-species/bridging biomarkers in a clinically relevant porcine model of neonatal HIE with functional analysis. Six miRNAs—miR-374a, miR-181b, miR-181a, miR-151a, miR-148a and miR-128—were significantly and rapidly upregulated 1-h post-HI. Changes in miR-374a, miR-181b and miR-181a appeared specific to moderate-severe HI. Histopathological injury and five miRNAs displayed positive correlations and were predictive of MRS Lac/Cr ratios. Bioinformatic analysis identified that components of the bone morphogenic protein (BMP) family may be targets of miR-181a. Inhibition of miR-181a increased neurite length in both SH-SY5Y cells at 1 DIV (days in vitro) and in primary cultures of rat neuronal midbrain at 3 DIV. In agreement, inhibition of miR-181a increased expression of BMPR2 in differentiating SH-SY5Y cells. These miRNAs may therefore act as early biomarkers of HIE, thereby allowing for rapid diagnosis and timely therapeutic intervention and may regulate expression of signalling pathways vital to neuronal survival.

Deregulated miR-384 serves as a biomarker in neonatal hypoxic-ischemic encephalopathy and alleviates microglia-mediated neuroinflammation

Microglia-mediated neuroinflammation is important in the pathogenesis of neonatal hypoxic-ischemic encephalopathy (HIE). This study aimed to investigate the expression of microRNA-384 (miR-384) in HIE newborns and evaluate the clinical and functional role of miR-384 in HIE diagnosis and neuroinflammation. The expression of miR-384 was estimated using quantitative real-time PCR. The levels of proinflammatory cytokines were examined using ELISA. Receiver operating characteristic (ROC) analysis was applied to evaluate the diagnostic performance of miR-384. The oxygen-glucose deprivation (OGD) experiment was adopted to activate primary neonatal microglia. A putative target of miR-384 was analyzed by bioinformatics prediction and a luciferase reporter assay. The expression of miR-384 was decreased in the serum of HIE newborns and OGD-induced activated microglia. Serum miR-384 had relatively high diagnostic accuracy for the screening of HIE cases from healthy newborns and the differentiation between newborns with different HIE severities. The OGD-induced increase in microglial neuroinflammation was significantly attenuated by the overexpression of miR-384, and AKT3, as a downstream target of miR-384, was inhibited by miR-384 in activated microglia. The data of this study demonstrated that decreased serum miR-384 expression may be a novel noninvasive biomarker for the diagnosis and progression of neonatal HIE. miR-384 can inhibit the neuroinflammation in activated microglia, which may be mediated by targeting AKT3.

Clinical Implications of Epigenetic Dysregulation in Perinatal Hypoxic-Ischemic Brain Damage

Placental and fetal hypoxia caused by perinatal hypoxic-ischemic events are major causes of stillbirth, neonatal morbidity, and long-term neurological sequelae among surviving neonates. Brain hypoxia and associated pathological processes such as excitotoxicity, apoptosis, necrosis, and inflammation, are associated with lasting disruptions in epigenetic control of gene expression contributing to neurological dysfunction. Recent studies have pointed to DNA (de)methylation, histone modifications, and non-coding RNAs as crucial components of hypoxic-ischemic encephalopathy (HIE). The understanding of epigenetic dysregulation in HIE is essential in the development of new clinical interventions for perinatal HIE. Here, we summarize our current understanding of epigenetic mechanisms underlying the molecular pathology of HI brain damage and its clinical implications in terms of new diagnostic, prognostic, and therapeutic tools.

Validation of Altered Umbilical Cord Blood MicroRNA Expression in Neonatal Hypoxic-Ischemic Encephalopathy

Importance

Neonatal hypoxic-ischemic encephalopathy (HIE) remains a significant cause of neurologic disability. Identifying infants suitable for therapeutic hypothermia (TH) within a narrow therapeutic time is difficult. No single robust biochemical marker is available to clinicians.

Objective

To assess the ability of a panel of candidate microRNA (miRNA) to evaluate the development and severity of encephalopathy following perinatal asphyxia (PA).

Design, Setting, and Participants

This validation study included 2 cohorts. For the discovery cohort, full-term infants with PA were enrolled at birth to the Biomarkers in Hypoxic-Ischemic Encephalopathy (BiHiVE1) study (2009-2011) in Cork, Ireland. Encephalopathy grade was defined using early electroencephalogram and Sarnat score (n = 68). The BiHiVE1 cohort also enrolled healthy control infants (n = 22). For the validation cohort, the BiHiVE2 multicenter study (2013-2015), based in Cork, Ireland (7500 live births per annum), and Karolinska Huddinge, Sweden (4400 live births per annum), recruited infants with PA along with healthy control infants to validate findings from BiHiVE1 using identical recruitment criteria (n = 80). The experimental design was formulated prior to recruitment, and analysis was conducted from June 2016 to March 2017.

Main Outcomes and Measures

Alterations in umbilical cord whole-blood miRNA expression.

Results

From 170 neonates, 160 were included in the final analysis. The BiHiVE1 cohort included 87 infants (21 control infants, 39 infants with PA, and 27 infants with HIE), and BiHiVE2 included 73 infants (control [n = 22], PA [n = 26], and HIE [n = 25]). The BiHiVE1 and BiHiVE2 had a median age of 40 weeks (interquartile range [IQR], 39-41 weeks) and 40 weeks (IQR, 39-41 weeks), respectively, and included 56 boys and 31 girls and 45 boys and 28 girls, respectively. In BiHiVE1, 12 candidate miRNAs were identified, and 7 of these miRNAs were chosen for validation in BiHiVE2. The BiHiVE2 cohort showed consistent alteration of 3 miRNAs; miR-374a-5p was decreased in infants diagnosed as having HIE compared with healthy control infants (median relative quantification, 0.38; IQR, 0.17-0.77 vs 0.95; IQR, 0.68-1.19; P = .009), miR-376c-3p was decreased in infants with PA compared with healthy control infants (median, 0.42; IQR, 0.21-0.61 vs 0.90; IQR, 0.70-1.30; P = .004), and mir-181b-5p was decreased in infants eligible for TH (median, 0.27; IQR, 0.14-1.41) vs 1.18; IQR, 0.70-2.05; P = .02).

Conclusions and Relevance

Altered miRNA expression was detected in umbilical cord blood of neonates with PA and HIE. These miRNA could assist diagnostic markers for early detection of HIE and PA at birth.

The latest progress on miR-374 and its functional implications in physiological and pathological processes

Non‐coding RNAs (ncRNAs) have been emerging players in cell development, differentiation, proliferation and apoptosis. Based on their differences in length and structure, they are subdivided into several categories including long non‐coding RNAs (lncRNAs >200nt), stable non‐coding RNAs (60‐300nt), microRNAs (miRs or miRNAs, 18‐24nt), circular RNAs, piwi‐interacting RNAs (26‐31nt) and small interfering RNAs (about 21nt). Therein, miRNAs not only directly regulate gene expression through pairing of nucleotide bases between the miRNA sequence and a specific mRNA that leads to the translational repression or degradation of the target mRNA, but also indirectly affect the function of downstream genes through interactions with lncRNAs and circRNAs. The latest studies have highlighted their importance in physiological and pathological processes. MiR‐374 family member are located at the X‐chromosome inactivation center. In recent years, numerous researches have uncovered that miR‐374 family members play an indispensable regulatory role, such as in reproductive disorders, cell growth and differentiation, calcium handling in the kidney, various cancers and epilepsy. In this review, we mainly focus on the role of miR‐374 family members in multiple physiological and pathological processes. More specifically, we also summarize their promising potential as novel prognostic biomarkers and therapeutic targets from bench to bedside.

The role of microRNAs in newborn brain development and hypoxic ischaemic encephalopathy

Neonates can develop hypoxic-ischaemic encephalopathy (HIE) due to lack of blood supply or oxygen, resulting in a major cause of death and disability among term newborns. However, current definitive treatment of therapeutic hypothermia, will only benefit one out of nine babies. Furthermore, the mechanisms of HIE and therapeutic hypothermia are not fully understood. Recently, microRNAs (miRNAs) have become of interest to many researchers due to their important role in post-transcriptional control and deep evolutionary history. Despite this, role of miRNAs in newborns with HIE remains largely unknown due to limited research in this field. Therefore, this review aims to understand the role of miRNAs in normal brain development and HIE pathophysiology with reliance on extrapolated data from other diseases, ages and species due to current limited data. This will provide us with an overview of how miRNAs in normal brain development changes after HIE. Furthermore, it will indicate how miRNAs are affected specifically or globally by the various pathophysiological events. In addition, we discuss about how drugs and commercially available agents can specifically target certain miRNAs as a mechanism of action and potential safety issue with off-target effects. Improving our understanding of the role of miRNAs on the cellular response after HIE would enhance the success of effective diagnosis, prognosis, and treatment of newborns with HIE.

Cholesterol cholelithiasis: part of a systemic metabolic disease, prone to primary prevention

Cholesterol gallstone disease have relationships with various conditions linked with insulin resistance, but also with heart disease, atherosclerosis, and cancer. These associations derive from mechanisms active at a local (i.e. gallbladder, bile) and a systemic level and are involved in inflammation, hormones, nuclear receptors, signaling molecules, epigenetic modulation of gene expression, and gut microbiota. Despite advanced knowledge of these pathways, the available therapeutic options for symptomatic gallstone patients remain limited. Therapy includes oral litholysis by the bile acid ursodeoxycholic acid (UDCA) in a small subgroup of patients at high risk of postdissolution recurrence, or laparoscopic cholecystectomy, which is the therapeutic radical gold standard treatment. Cholecystectomy, however, may not be a neutral event, and potentially generates health problems, including the metabolic syndrome. Areas covered: Several studies on risk factors and pathogenesis of cholesterol gallstone disease, acting at a systemic level have been reviewed through a PubMed search. Authors have focused on primary prevention and novel potential therapeutic strategies. Expert commentary: The ultimate goal appears to target the manageable systemic mechanisms responsible for gallstone occurrence, pointing to primary prevention measures. Changes must target lifestyles, as well as experimenting innovative pharmacological tools in subgroups of patients at high risk of developing gallstones.

Biomarkers in neonatal hypoxic-ischemic encephalopathy-Review of the literature to date and future directions for research

The widespread introduction of therapeutic hypothermia as a standard of care in hypoxic-ischemic encephalopathy (HIE) has brought increasing pressure on clinicians to make an early and accurate assessment of the degree of hypoxic injury (HI) that has occurred and the severity of the encephalopathy that will ensue. No single blood-based marker is currently robust enough to detect significant HI or predict outcome. However, research in the field has been active in the last 10 years and we know that HIE is associated with predictable alterations in the expression of a number of inflammatory proteins, neuron-specific proteins, metabolite pathways, and microRNA. These alterations evolve quickly over the first hours and days of life. Predictive power varies depending on the timing of measurement of the biomarker, the sample type, and the case mix of the cohort examined. Combining clinical data with biochemical measurements is currently the most likely path toward improved detection and prediction of outcome in neonatal HIE.