MicroRNA-194 Regulates the Development and Differentiation of Sensory Patches and Statoacoustic Ganglion of Inner Ear by Fgf4

MicroRNA-194-5p/Heparin-binding EGF-like growth factor signaling mediates dexamethasone-induced activation of pseudorabies virus in rat pheochromocytoma cells

Pseudorabies virus (PRV) is a neurotropic virus, which infects a wide range of mammals. The activity of PRV is gradually suppressed in hosts that have tolerated the primary infection. Increased glucocorticoid levels resulting from stressful stimuli overcome repression of PRV activity. However, the host cell mechanism involved in the activation processes under stressful conditions remains unclear. In this study, infection of rat PC-12 pheochromocytoma cells with neuronal properties using PRV at a multiplicity of infection (MOI) = 1 for 24 h made the activity of PRV be the relatively repressed state, and then incubation with 0.5 μM of the corticosteroid dexamethasone (DEX) for 4 h overcomes the relative repression of PRV activity. RNA-seq deep sequencing and bioinformatics analyses revealed different microRNA and mRNA profiles of PC-12 cells with/without PRV and/or DEX treatment. qRT-PCR and western blot analyses confirmed the negative regulatory relationship of miRNA-194-5p and its target heparin-binding EGF-like growth factor (Hbegf); a dual-luciferase reporter assay revealed that Hbegf is directly targeted by miRNA-194-5p. Further, miRNA-194-5p mock transfection contributed to PRV activation, Hbegf was downregulated in DEX-treated PRV infection cells, and Hbegf overexpression contributed to returning activated PRV to the repression state. Moreover, miRNA-194-5p overexpression resulted in reduced levels of HBEGF, c-JUN, and p-EGFR, whereas Hbegf overexpression suppressed the reduction caused by miRNA-194-5p overexpression. Overall, this study is the first to report that changes in the miR-194-5p-HBEGF/EGFR pathway in neurons are involved in DEX-induced activation of PRV, laying a foundation for the clinical prevention of stress-induced PRV activation.

Exosomes from mmu_circ_0001052-modified adipose-derived stem cells promote angiogenesis of DFU via miR-106a-5p and FGF4/p38MAPK pathway

Background

Diabetic foot ulcer (DFU) is a chronic infectious disease caused by diabetes mellitus (DM). Angiogenesis plays the decisive role in wound healing of DFU. Adipose-derived stem cells (ADSCs) can ameliorate angiogenesis in DFU by exosomes. This study aims to determine the mechanism of exosomes from mmu_circ_0001052-modified ADSCs in angiogenesis of DFU.

Methods

HUVECs were induced by high glucose and mice stimulated using STZ injection during high-fat feeding, which were treated with exosomes derived from mmu_circ_0001052-modified ADSCs. Real-time PCR determined the expression of gene and western blot determined protein levels. Proliferation, migration, apoptosis and angiogenesis of HUVECs were studied by MTT assay, transwell test, flow cytometry and tube formation experiment, respectively. Histological lesion of wound was determined by HE staining.

Results

The expression of circ_0001052 was upregulated in ADSCs and miR-106a-5p elevated in high glucose-induced HUVECs. Exosomal mmu_circ_0001052 significantly accelerated wound healing in mice with DFU. Also, exosomal mmu_circ_0001052 evoked the reduction of miR-106a-5p and the elevation of FGF4 in high glucose-induced HUVECs and wound tissue of DFU mice. Exosomal mmu_circ_0001052 was determined to sponge miR-106a-5p that targeted FGF4 in DFU. In high glucose-induced HUVECs, exosomal mmu_circ_0001052 inhibited apoptosis and miR-106a-5p expression, and meanwhile promoted proliferation, migration, angiogenesis and expressions of FGF4, VEGF and p-p38/p38, which were reversed by miR-106a-5p elevation.

Conclusion

Mmu_circ_0001052 in ADSCs-derived exosomes promote angiogenesis of DFU via miR-106a-5p and FGF4/p38MAPK pathway.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-03015-7.

MiR-194-5p serves as a potential biomarker and regulates the proliferation and apoptosis of hippocampus neuron in children with temporal lobe epilepsy

BACKGROUND

The aim of the present study is to explore the expression level and the clinical significance of miR-194-5p to the children with temporal lobe epilepsy, and investigate its functions in regulating cell behaviors of hippocampal neurons.

METHODS

The expression level of miR-194-5p was detected in the serum of 59 temporal lobe epilepsy (TLE) children and 63 healthy children. To further study the role of miR-194-5p in the development of TLE in children, the epileptiform discharge model was established in rat hippocampal neurons to mimic TLE conditions in children. Receiver operator characteristic (ROC) curves and area under the ROC curve were established to evaluate the diagnostic value of serum microRNAs to the differentiation of the TLE group and healthy group. The influence of miR-194-5p on the proliferation and apoptosis of hippocampus neurons was examined by using MTT and flow cytometric apoptosis assay. Luciferase reporter assay was performed to confirm the target gene of miR-194-5p.

RESULTS

The result demonstrated that miR-194-5p was significantly dysregulated in plasma of TLE patients. Analysis of ROCs showed that the miR-194-5p had high specificity and sensitivity in the diagnosis of the TLE in children. The expression of miR-194-5p was found to increase in the hippocampal cells cultured in the magnesium-free medium through quantitative real-time polymerase chain reaction. Hyper-expressed of miR-194-5p reversed TLE-induced reduction for the cell viability, and inhibited the cell apoptosis induced by TLE. Insulin-like growth factor 1 receptor (IGF1R) was proved to be a direct target gene of miR-194-5p.

CONCLUSION

MiR-194-5p is a likely potential biomarker and treatment target of TLE in children. IGF1R might be involved in the regulatory role of miR-194-5p in hippocampus neuron apoptosis.

Age-related transcriptome changes in Sox2+ supporting cells in the mouse cochlea

Background

Inner ear supporting cells (SCs) in the neonatal mouse cochlea are a potential source for hair cell (HC) regeneration, but several studies have shown that the regeneration ability of SCs decreases dramatically as mice age and that lost HCs cannot be regenerated in adult mice. To better understand how SCs might be better used to regenerate HCs, it is important to understand how the gene expression profile changes in SCs at different ages.

Methods

Here, we used Sox2^GFP/+ mice to isolate the Sox2+ SCs at postnatal day (P)3, P7, P14, and P30 via flow cytometry. Next, we used RNA-seq to determine the transcriptome expression profiles of P3, P7, P14, and P30 SCs. To further analyze the relationships between these age-related and differentially expressed genes in Sox2+ SCs, we performed gene ontology (GO) analysis.

Results

Consistent with previous reports, we also found that the proliferation and HC regeneration ability of isolated Sox2+ SCs significantly decreased as mice aged. We identified numerous genes that are enriched and differentially expressed in Sox2+ SCs at four different postnatal ages, including cell cycle genes, signaling pathway genes, and transcription factors that might be involved in regulating the proliferation and HC differentiation ability of SCs. We thus present a set of genes that might regulate the proliferation and HC regeneration ability of SCs, and these might serve as potential new therapeutic targets for HC regeneration.

Conclusions

In our research, we found several genes that might play an important role in regulating the proliferation and HC regeneration ability of SCs. These datasets are expected to serve as a resource to provide potential new therapeutic targets for regulating the ability of SCs to regenerate HCs in postnatal mammals.

Tackling Aging by Using miRNA as a Target and a Tool

miRNA is a class of short noncoding RNA that regulates gene expression at the post-transcriptional level. Evidence of age-associated changes in miRNA expression has been collected in models ranging from nematodes to humans; however, there has been little discussion of how to turn our knowledge of miRNA biology into antiaging therapy. This opinion article provides a snapshot of our current understanding of the roles of miRNA in modulating the aging process. We discuss major chemical techniques for modifying the miRNA structure as well as developing delivery systems for intervention. Finally, technical needs to be met for bench-to-clinic translation of miRNA-based interventions are highlighted for future research.