MiR-140-5p targets Prox1 to regulate the proliferation and differentiation of neural stem cells through the ERK/MAPK signaling pathway

Mesenchymal Stem Cell-Derived Extracellular Vesicles Alleviate Brain Damage Following Subarachnoid Hemorrhage via the Interaction of miR-140-5p and HDAC7

Subarachnoid hemorrhage (SAH) triggers severe neuroinflammation and cognitive impairment, where microglial M1 polarization exacerbates the injury and M2 polarization mitigates damage. Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs), carrying microRNA (miR)-140-5p, offer therapeutic promise by targeting the cAMP/PKA/CREB pathway and modulating microglial responses, demonstrating a novel approach for addressing SAH-induced brain injury. This research explored the role of miR-140-5p delivered by MSC-EVs in mitigating brain damage following SAH. Serum from SAH patients and healthy individuals was analyzed for miR-140-5p and cAMP levels. The association between miR-140-5p levels, brain injury severity, and patient survival was examined, along with the target relationship between miR-140-5p and histone deacetylases 7 (HDAC7). MSC-EVs were characterized for their ability to cross the blood-brain barrier and modulate the HDAC7/AKAP12/cAMP/PKA/CREB axis, reducing M1 polarization and inflammation. The therapeutic effect of MSC-EV-miR-140-5p was demonstrated in an SAH mouse model, showing reduced neuronal apoptosis and improved neurological function. This study highlights the potential of MSC-EV-miR-140-5p in mitigating SAH-induced neuroinflammation and brain injury, providing a foundation for developing MSC-EV-based treatments for SAH.

Survivin enhances hippocampal neurogenesis and cognitive function in Alzheimer's disease mouse model

AIMS

Cognitive impairment is associated with reduced hippocampal neurogenesis; however, the causes of decreased hippocampal neurogenesis remain highly controversial. Here, we investigated the role of survivin in the modulation of hippocampal neurogenesis in AD.

METHODS

To investigate the effect of survivin on neurogenesis in neural stem cells (NSCs), we treated mouse embryonic NSCs with a survivin inhibitor (YM155) and adeno-associated viral survivin (AAV-Survivin). To explore the potential role of survivin expression in AD, AAV9-Survivin or AAV9-GFP were injected into the dentate gyrus (DG) of hippocampus of 7-month-old wild-type and 5XFAD mice. Cognitive function was measured by the Y maze and Morris water maze. Neurogenesis was investigated by BrdU staining, immature, and mature neuron markers.

RESULTS

Our results indicate that suppression of survivin expression resulted in decreased neurogenesis. Conversely, overexpression of survivin using AAV-Survivin restored neurogenesis in NSCs that had been suppressed by YM155 treatment. Furthermore, the expression level of survivin decreased in the 9-month-old 5XFAD compared with that in wild-type mice. AAV-Survivin-mediated overexpression of survivin in the DG in 5XFAD mice enhanced neurogenesis and cognitive function.

CONCLUSION

Hippocampal neurogenesis can be enhanced by survivin overexpression, suggesting that survivin could serve as a promising therapeutic target for the treatment of AD.

The Establishment and Optimization of a Chicken Primordial Germ Cell Induction Model Using Small-Molecule Compounds

In recent years, inducing pluripotent stem cells to differentiate into functional primordial germ cells (PGCs) in vitro has become an important method of obtaining a large number of PGCs. However, the instability and low induction efficiency of the in vitro PGC induction system restrict the application of PGCs in transgenic animal production, germplasm resource conservation and other fields. In this study, we successfully established a two-step induction model of chicken PGCs in vitro, which significantly improved the formation efficiency of PGC-like cells (PGCLCs). To further improve the PGC formation efficiency in vitro, 5025 differentially expressed genes (DEGs) were obtained between embryonic stem cells (ESCs) and PGCs through RNA-seq. GO and KEGG enrichment analysis revealed that signaling pathways such as BMP4, Wnt and Notch were significantly activated during PGC formation, similar to other species. In addition, we noted that cAMP was activated during PGC formation, while MAPK was suppressed. Based on the results of our analysis, we found that the PGC formation efficiency was significantly improved after activating Wnt and inhibiting MAPK, and was lower than after activating cAMP. To sum up, in this study, we successfully established a two-step induction model of chicken PGCs in vitro with high PGC formation efficiency, which lays a theoretical foundation for further demonstrating the regulatory mechanism of PGCs and realizing their specific applications.

Pax6 affects Ras-Raf-ERK1/2 in mouse aging brain

Pax6, a transcription factor and multifunctional protein, changes during aging. It also interacts with regulator proteins involved in cell metabolism and survival signalling pathways including Ras-GAP. Many forms of Ras, Raf and ERK1/2 are known but information on their region-specific expression patterns are unavailable from brain during aging. Therefore, it has been intended to evaluate expressions of Pax6 and forms of Ras, Raf, ERK1/2 in hippocampus, caudate nucleus, amygdale, cerebral cortex, cerebellum and olfactory lobe. Association of Pax6 with Ras, Raf and ERK1/2 was evaluated in co-culture (PC-12, C6-glia, U-87 MG) of neuroglia cell lines. Impacts of Pax6 were evaluated by siRNA mediated knockdown and expression patterns Ras-Raf-Erk1/2. Analysis of activities of Pax6 and impacts of 5'AMP, wild-type and mutant ERK were done by RT-PCR and luciferase reporter assay. Results indicate age-dependent changes of Pax6, Ras, Raf, ERK1/2 in different regions of brain of young and old mice. Erk1/2 shows synergistic activities to Pax6.

Differential Expression of MicroRNA (MiR-27, MiR-145) among Dental Pulp Stem Cells (DPSCs) Following Neurogenic Differentiation Stimuli

This study sought to evaluate the expression of previously identified microRNAs known to regulate neuronal differentiation in mesenchymal stem cells (MSCs), including miR-27, miR-125, miR-128, miR-135, miR-140, miR-145, miR-218 and miR-410, among dental pulp stem cells (DPSCs) under conditions demonstrated to induce neuronal differentiation. Using an approved protocol, n = 12 DPSCs were identified from an existing biorepository and treated with basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF), which were previously demonstrated to induce neural differentiation markers including Sox1, Pax6 and NFM among these DPSCs. This study revealed that some microRNAs involved in the neuronal differentiation of MSCs were also differentially expressed among the DPSCs, including miR-27 and miR-145. In addition, this study also revealed that administration of bFGF and EGF was sufficient to modulate miR-27 and miR-145 expression in all of the stimulus-responsive DPSCs but not among all of the non-responsive DPSCs-suggesting that further investigation of the downstream targets of these microRNAs may be needed to fully evaluate and understand these observations.

miR-6216 Regulates Neural Stem Cell Proliferation by Targeting RAB6B

Neural stem cells (NSCs) are a class of self-renewing, multipotent and undifferentiated progenitor cells that retain the capacity to both glial and neuronal lineages. MicroRNAs (miRNAs) are small non-coding RNAs that play an important role in stem cell fate determination and self-renewal. Our previous RNA-seq data indicated that the expression of miR-6216 was decreased in denervated hippocampal exosomes compared with normal. However, whether miR-6216 participates in regulating NSC function remains to be elucidated. In this study, we demonstrated that miR-6216 negatively regulates RAB6B expression. Forced overexpression of miR-6216 inhibited NSC proliferation, and overexpression of RAB6B promoted NSC proliferation. These findings suggest that miR-6216 played an important role in regulating NSC proliferation via targeting RAB6B, and improve the understanding of the miRNA-mRNA regulatory network that affects NSC proliferation.

The involvement and therapeutic potential of lncRNA Kcnq1ot1/miR-34a-5p/Sirt1 pathway in arsenic trioxide-induced cardiotoxicity

BACKGROUND/AIMS

Arsenic trioxide (ATO) is the first-line therapeutic drug for acute promyelocytic leukemia. However, the cardiotoxicity of ATO limits its clinical application. This study aims to explore the long noncoding RNA (lncRNA) involved molecular mechanism in ATO-induced cardiotoxicity and to identify available prevention strategies.

METHODS

ATO was administered to mice or primary cultured mouse cardiomyocytes. Small interfering RNA targeting lncRNA Kcnq1ot1 (si-Kcnq1ot1) was used to knockdown lncRNA Kcnq1ot1. MiR-34a-5p mimic and antisense morpholino oligonucleotide targeting miR-34a-5p (AMO-34a-5p) were used to upregulate and downregulate the expression of miR-34a-5p, respectively. TUNEL staining was conducted to detect cell DNA damage. Flow cytometry assay was used to detect cell apoptosis. Western blot was conducted to detect Bcl-2, Bax and Sirt1 protein expression. Real-time PCR was used to detect lncRNA Kcnq1ot1, miR-34a-5p, and Sirt1 mRNA expression. Dual-luciferase reporter assay was performed to validate the predicted binding site.

RESULTS

ATO induced apoptosis in cardiomyocytes both in vivo and in vitro. Simultaneously, the expression of lncRNA Kcnq1ot1 and Sirt1 was downregulated, and miR-34a-5p was upregulated. MiR-34a-5p has binding sites with lncRNA Kcnq1ot1 and Sirt1. Knockdown of lncRNA Kcnq1ot1 induced apoptosis of cardiomyocytes, with increased miR-34a-5p and decreased Sirt1 expression. Inhibition of miR-34a-5p attenuated si-Kcnq1ot1-induced apoptosis in cardiomyocytes. Therefore, the lncRNA Kcnq1ot1/miR-34a-5p/Sirt1 signaling pathway is involved in ATO-induced cardiotoxicity. Propranolol alleviated ATO-induced apoptosis in cardiomyocytes both in vivo and in vitro, which was related to the lncRNA Kcnq1ot1/miR-34a-5p/Sirt1 signaling pathway.

CONCLUSION

The lncRNA Kcnq1ot1/miR-34a-5p/Sirt1 pathway is involved in ATO-induced cardiotoxicity. Propranolol can attenuate ATO-induced cardiotoxicity at least partially through the lncRNA Kcnq1ot1/miR-34a-5p/Sirt1 pathway. Combined administration with propranolol may be a new strategy for alleviating the cardiotoxicity of ATO.

Non-Coding RNAs in the Regulation of Hippocampal Neurogenesis and Potential Treatment Targets for Related Disorders

Non-coding RNAs (ncRNAs), including miRNAs, lncRNAs, circRNAs, and piRNAs, do not encode proteins. Nonetheless, they have critical roles in a variety of cellular activities-such as development, neurogenesis, degeneration, and the response to injury to the nervous system-via protein translation, RNA splicing, gene activation, silencing, modifications, and editing; thus, they may serve as potential targets for disease treatment. The activity of adult neural stem cells (NSCs) in the subgranular zone of the hippocampal dentate gyrus critically influences hippocampal function, including learning, memory, and emotion. ncRNAs have been shown to be involved in the regulation of hippocampal neurogenesis, including proliferation, differentiation, and migration of NSCs and synapse formation. The interaction among ncRNAs is complex and diverse and has become a major topic within the life science. This review outlines advances in research on the roles of ncRNAs in modulating NSC bioactivity in the hippocampus and discusses their potential applications in the treatment of illnesses affecting the hippocampus.

circAFF1 enhances intracerebral hemorrhage induced neuronal ferroptosis by targeting miR-140-5p to regulate GSK-3β mediated Wnt/β-catenin signal pathway

OBJECTIVE

Ferroptosis is a newly emerged form of cell apoptosis and one of the characters of intracerebral hemorrhage (ICH). Currently there are limited therapeutic approaches for ICH. This study aims to explore the possible regulatory mechanism of ferroptosis in ICH.

METHODS

Hemoglobin (Hb) was used to treat neurons to mimic ICH cell model. The cell viability was assessed by CCK-8 assay. The contents of iron ion, reactive oxygen species (ROS), malondialdehyde (MDA) and glutathione (GSH) were also measured. The expressions of ferroptosis related proteins were determined by qRT-PCR and Western blot. The interaction among circAFF1, GSK-3β and miR-140-5p was verified. In vivo ICH models were established and assessed using mNSS. The morphology and wet/dry ratio of brain were also observed and calculated.

RESULTS

circAFF1 was highly expressed in ICH cell model. Knockdown of circAFF1 attenuated Hb-induced neuronal ferroptosis, as evidenced by inhibiting cell viability, ROS, MDA and iron ion, and promoting GDH levels, which can be counteracted by miR-140-5p knockdown. circAFF1 can target miR-140-5p, and GSK-3β was a target gene of miR-140-5p. The effect of miR-140-5p on neuronal ferroptosis can be reversed by GSK-3β overexpression. In vivo experiments identified knockdown of circAFF1 suppress ICH injury and inhibits neuronal ferroptosis through regulating miR-140-5p/GSK-3β axis.

CONCLUSION

circAFF1 knockdown can suppress neuronal ferroptosis in vivo to attenuate ICH injury, which was associated with its targeting with miR-140-5p to up-regulate GSK-3β and to suppress Wnt/β-catenin signal pathway.

Optimal therapeutic conditions for the neural stem cell-based management of ischemic stroke: a systematic review and network meta-analysis based on animal studies

BACKGROUND

In order to promote the clinical translation of preclinical findings, it is imperative to identify the most optimal therapeutic conditions and adopt them for further animal and human studies. This study aimed to fully explore the optimal conditions for neural stem cell (NSC)-based ischemic stroke treatment based on animal studies.

METHODS

The PubMed, Ovid-Embase, and Web of Science databases were searched in December 2021. The screening of search results, extraction of relevant data, and evaluation of study quality were performed independently by two reviewers.

RESULTS

In total, 52 studies were included for data analysis. Traditional meta-analysis showed that NSCs significantly reduced the modified neurological severity score (mNSS) and volume of cerebral infarct in animal models of ischemic stroke. Network meta-analysis showed that allogeneic embryonic tissue was the best source of NSCs. Further, intracerebral transplantation was the most optimal route of NSC transplantation, and the acute phase was the most suitable stage for intervention. The optimal number of NSCs for transplantation was 1-5×10⁵ in mouse models and 1×10⁶ or 1.8×10⁶ in rat models.

CONCLUSIONS

We systematically explored the therapeutic strategy of NSCs in ischemic stroke, but additional research is required to develop optimal therapeutic strategies based on NSCs. Moreover, it is necessary to further improve and standardize the design, implementation, measuring standards, and reporting of animal-based studies to promote the development of better animal experiments and clinical research.

Targeting the Erk1/2 and autophagy signaling easily improved the neurobalst differentiation and cognitive function after young transient forebrain ischemia compared to old gerbils

The hippocampal neurogenesis occurs constitutively throughout adulthood in mammalian species, but declines with age. In this study, we overtly found that the neuroblast proliferation and differentiation in the subgranular zone and the maturation into fully functional and integrated neurons in the granule-cell layer in young gerbils following cerebral ischemia/reperfusion was much more than those in old gerbils. The neurological function and cognitive and memory-function rehabilitation in the young gerbils improved faster than those in the old one. These results demonstrated that, during long term after cerebral ischemia/reperfusion, the ability of neurogenesis and recovery of nerve function in young animals were significantly higher than that in the old animals. We found that, after 14- and 28-day cerebral ischemia/reperfusion, the phosphorylation of MEK1/2, ERK1/2, p90RSK, and MSK1/2 protein levels in the hippocampus of young gerbils was significantly much higher than that of old gerbils. The levels of autophagy-related proteins, including Beclin-1, Atg3, Atg5, and LC3 in the hippocampus were effectively maintained and elevated at 28 days after cerebral ischemia/reperfusion in the young gerbils compared with those in the old gerbils. These results indicated that an increase or maintenance of the phosphorylation of ERK1/2 signal pathway and autophagy-related proteins was closely associated with the neuroblast proliferation and differentiation and the process of maturation into neurons. Further, we proved that neuroblast proliferation and differentiation in the dentate gyrus and cognitive function were significantly reversed in young cerebral ischemic gerbils by administering the ERK inhibitor (U0126) and autophagy inhibitor (3MA). In brief, following experimental young ischemic stroke, the long-term promotion of the neurogenesis in the young gerbil’s hippocampal dentate gyrus by upregulating the phosphorylation of ERK signaling pathway and maintaining autophagy-related protein levels, it overtly improved the neurological function and cognitive and memory function.

SENP2-PLCβ4 signaling regulates neurogenesis through the maintenance of calcium homeostasis

Neurogenesis plays a critical role in brain physiology and behavioral performance, and defective neurogenesis leads to neurological and psychiatric disorders. Here, we show that PLCβ4 expression is markedly reduced in SENP2-deficient cells and mice, resulting in decreased IP₃ formation and altered intracellular calcium homeostasis. PLCβ4 stability is regulated by the SUMO-dependent ubiquitin-mediated proteolytic pathway, which is catalyzed by PIAS2α and RNF4. SUMOylated PLCβ4 is transported to the nucleus through Nup205- and RanBP2-dependent pathways and regulates nuclear signaling. Furthermore, dysregulated calcium homeostasis induced defects in neurogenesis and neuronal viability in SENP2-deficient mice. Finally, SENP2 and PLCβ4 are stimulated by starvation and oxidative stress, which maintain calcium homeostasis regulated neurogenesis. Our findings provide mechanistic insight into the critical roles of SENP2 in the regulation of PLCβ4 SUMOylation, and the involvement of SENP2-PLCβ4 axis in calcium homeostasis regulated neurogenesis under stress.