Expression of miR-210 mediated by adeno-associated virus performed neuroprotective effects on a rat model of acute spinal cord injury

Tenuigenin activates the IRS1/Akt/mTOR signaling by blocking PTPN1 to inhibit autophagy and improve locomotor recovery in spinal cord injury

ETHNOPHARMACOLOGICAL RELEVANCE

Tenuigenin (TEN) is a main pharmacologically active component of Polygala tenuifolia Willd. (Polygalaceae), which has shown neuroprotective functions in Alzheimer's disease. Moreover, TEN also demonstrated an anti-oxidative impact in an in vitro model of Parkinson's disease, reducing damage and loss of dopaminergic neurons.

AIM

This work focuses on the impact of TEN on locomotor recovery following spinal cord injury (SCI) and underpinning molecules involved.

METHODS

A rat model of SCI was generated, and the rats were treated with TEN, oe-PTPN1 (PTP non-receptor type 1), a protein kinase B (Akt)/mammalian target of rapamycin (mTOR) antagonist LY294002, or an autophagy inhibitor 3-methyladenine (3-MA). Subsequently, locomotor function was detected. Pathological changes and neuronal activity in the spinal cord tissues were analyzed by hematoxylin and eosin staining, Nissl staining, and TUNEL assays. Protein expression of Beclin-1 and microtubule associated protein 1 light chain 3 beta (LC3B)-II/LC3B-I, PTPN1, IRS1, mTOR, and phosphorylated Akt (p-Akt) was analyzed by western blot assays. The LC3B expression was further examined by immunofluorescence staining.

RESULTS

Treatment with TEN restored the locomotor function of SCI rats, reduced the cavity area and cell apoptosis, upregulated growth-associated protein 43 and neurofilament 200, and decreased the Beclin-1 and LC3B-II/LC3B-I levels in the spinal cord. TEN suppressed PTPN1 protein level, while PTPN1 suppressed IRS1 protein to reduce the p-Akt and mTOR levels. Either PTPN1 overexpression or LY294002 treatment blocked the promoting effect of TEN on SCI recovery. However, treatment with 3-MA suppressed autophagy, which consequently rescued the locomotor function and reduced neuron loss induced by PTPN1.

CONCLUSION

This study demonstrates that TEN suppresses autophagy to promote function recovery in SCI rats by blocking PTPN1 and rescuing the IRS1/Akt/mTOR signaling.

MicroRNA‑378: An important player in cardiovascular diseases (Review)

Cardiovascular disease (CVD) is a common chronic clinical condition and is the main cause of death in humans worldwide. Understanding the genetic and molecular mechanisms involved in the development of CVD is essential to develop effective prevention strategies and therapeutic measures. An increasing number of CVD‑related genetic studies have been conducted, including those on the potential roles of microRNAs (miRs). These studies have demonstrated that miR‑378 is involved in the pathological processes of CVD, including those of myocardial infarction, heart failure and coronary heart disease. Despite the potential importance of miR‑378 CVD, a comprehensive summary of the related literature is lacking. Thus, the present review aimed to summarize the findings of previous studies on the roles and mechanisms of miR‑378 in a variety of CVDs and provide an up‑to date basis for further r research targeting the prevention and treatment of CVDs.

miRNA Therapy in Laboratory Models of Acute Spinal Cord Injury in Rodents: A Meta-analysis

miRNA therapy is popularly investigated in treating acute spinal cord injury (SCI) and offers a significant prospect for the treatment of acute SCI. We aimed to provide pre-clinical validations of miRNA in the treatment of SCI. A systematic search of EMBASE, PubMed, Web of Science, the Cochrane Library, and Scopus databases was performed. Rats, which were the most used animals (70%, n = 46 articles), receiving miRNA therapy got prominent recovery in SCI models [BBB score, SMD 3.90, 95% CI 3.08-4.73, p < 0.01]. Locomotor function of fore and hind limbs in SCI mice receiving miRNA therapy (30%, n = 19 articles) [grip strength, SMD 3.22, 95% CI 2.14-4.26; p < 0.01; BBB score, SMD 3.47, 95% CI 2.38-4.56, p < 0.01; BMS, SMD 2.27, 95% CI 1.34-3.20, p < 0.01] also recovered better than mice in control group. Then, we conducted the subgroup analysis and did find that high-quality articles trended to report non-therapeutic effect of miRNA. Furtherly, we analyzed 46 miRNAs, including 9 miRNA families (miR-21-5p/34a-3p/124-3p/126-3p/223-3p/543-3p/30-3p/136-3p/15-5p), among which miR-30-3p/136-3p/15-5p family were not effective in recovering locomotor function of rats. Conclusively, miRNAs are curative drugs for SCI, however, appropriate miRNA carrier and which miRNA is the most efficacious for SCI should be furtherly investigated.

Therapeutic potential of small extracellular vesicles derived from mesenchymal stem cells for spinal cord and nerve injury

Neural diseases such as compressive, congenital, and traumatic injuries have diverse consequences, from benign mild sequelae to severe life-threatening conditions with associated losses of motor, sensory, and autonomic functions. Several approaches have been adopted to control neuroinflammatory cascades. Traditionally, mesenchymal stem cells (MSCs) have been regarded as therapeutic agents, as they possess growth factors and cytokines with potential anti-inflammatory and regenerative effects. However, several animal model studies have reported conflicting outcomes, and therefore, the role of MSCs as a regenerative source for the treatment of neural pathologies remains debatable. In addition, issues such as heterogeneity and ethical issues limited their use as therapeutic agents. To overcome the obstacles associated with the use of traditional agents, we explored the therapeutic potentials of extracellular vesicles (EVs), which contain nucleic acids, functional proteins, and bioactive lipids, and play crucial roles in immune response regulation, inflammation reduction, and cell-to-cell communication. EVs may surpass MSCs in size issue, immunogenicity, and response to the host environment. However, a comprehensive review is required on the therapeutic potential of EVs for the treatment of neural pathologies. In this review, we discuss the action mechanism of EVs, their potential for treating neural pathologies, and future perspectives regarding their clinical applications.

Protein tyrosine phosphatase 1B (PTP1B) as a potential therapeutic target for neurological disorders

Protein tyrosine phosphatase 1B (PTP1B) is a typical member of the PTP family, considered a direct negative regulator of several receptor and receptor-associated tyrosine kinases. This widely localized enzyme has been involved in the pathophysiology of several diseases. More recently, PTP1B has attracted attention in the field of neuroscience, since its activation in brain cells can lead to schizophrenia-like behaviour deficits, anxiety-like effects, neurodegeneration, neuroinflammation and depression. Conversely, PTP1B inhibition has been shown to prevent microglial activation, thus exerting a potent anti-inflammatory effect and has also shown potential to increase the cognitive process through the stimulation of hippocampal insulin, leptin and BDNF/TrkB receptors. Notwithstanding, most research on the clinical efficacy of targeting PTP1B has been developed in the field of obesity and type 2 diabetes mellitus (TD2M). However, despite the link existing between these metabolic alterations and neurodegeneration, no clinical trials assessing the neurological advantages of PTP1B inhibition have been performed yet. Preclinical studies, though, have provided strong evidence that targeting PTP1B could allow to reach different pathophysiological mechanisms at once. herefore, specific interventions or trials should be designed to modulate PTP1B activity in brain, since it is a promising strategy to decelerate or prevent neurodegeneration in aged individuals, among other neurological diseases. The present paper fails to include all neurological conditions in which PTP1B could have a role; instead, it focuses on those which have been related to metabolic alterations and neurodegenerative processes. Moreover, only preclinical data is discussed, since clinical studies on the potential of PTP1B inhibition for treating neurological diseases are still required.

MiRNAs as Promising Translational Strategies for Neuronal Repair and Regeneration in Spinal Cord Injury

Spinal cord injury (SCI) represents a devastating injury to the central nervous system (CNS) that is responsible for impaired mobility and sensory function in SCI patients. The hallmarks of SCI include neuroinflammation, axonal degeneration, neuronal loss, and reactive gliosis. Current strategies, including stem cell transplantation, have not led to successful clinical therapy. MiRNAs are crucial for the differentiation of neural cell types during CNS development, as well as for pathological processes after neural injury including SCI. This makes them ideal candidates for therapy in this condition. Indeed, several studies have demonstrated the involvement of miRNAs that are expressed differently in CNS injury. In this context, the purpose of the review is to provide an overview of the pre-clinical evidence evaluating the use of miRNA therapy in SCI. Specifically, we have focused our attention on miRNAs that are widely associated with neuronal and axon regeneration. “MiRNA replacement therapy” aims to transfer miRNAs to diseased cells and improve targeting efficacy in the cells, and this new therapeutic tool could provide a promising technique to promote SCI repair and reduce functional deficits.

Luminous MoS2 nanosheet-based electrochemiluminescence biosensor with biomimetic vesicle for miRNA-210 detection

In this work, a novel electrochemiluminescence (ECL) sensor has been developed to detect miRNA-210 in the serum of triple negative breast cancer (TNBC) patients. The luminous MoS₂ nanosheets were synthesized via the solvothermal method and served as ECL emitters for the first time. As a result, the ECL properties of as-prepared MoS₂ nanosheets were significantly improved. Furthermore, the biomimetic magnetic vesicles were used as capture platform in the ECL sensing strategy. Due to the highly efficient fluidity and magnetic property, the biomimetic vesicles with hairpin aptamers can capture target gene in the serum. After magnetic separation, the captured miRNA-210 can trigger the target-catalyzed hairpin assembly (CHA) sensing process on the magnetic electrode and hybridize MoS₂ nanosheets labeled probe DNA. The concentration of miRNA-210 can be quantified by the ECL enhancement of the MoS₂ nanosheets. This approach has achieved the sensitive detection for miRNA-210 in a range from 1 fM to 100 pM with the detection limit of 0.3 fM. The luminous MoS₂ nanosheets-based ECL sensing system with the biomimetic vesicles would provide a new pathway to explore 2D nanomaterials for developing a wide range of bioanalytical applications.

miR-378-3p alleviates contusion spinal cord injury by negatively regulating ATG12

MicroRNAs (miRNAs or miRs) serve essential roles in the pathogenic process of spinal cord injury (SCI). The present study investigated the role of miR-378-3p and autophagy-related 12 (ATG12) in SCI. RT-qPCR was used to detect the mRNA expression levels of miR-378-3p and ATG12. Cell viability and membrane integrity were evaluated using CCK-8 and LDH assays. For the analysis of the interaction between miR-378-3p and ATG12, a dual-luciferase reporter assay was conducted. The hindlimb function of rats was detected with the Basso, Beattie and Bresnahan score, and the motor deficit index score was used to evaluate nerve function. Using these approaches, it was identified that miR-378-3p expression was downregulated, while that of ATG12 was upregulated in SCI tissues and in cells exposed to hypoxia. Hypoxia repressed the expression of miR-378-3p via hypoxia-inducible factor 1-α. The overexpression of miR-378-3p exerted anti-apoptotic effects on nerve cells by directly repressing ATG12. The infusion of miR-378-3p improved hindlimb motor function and the neurological functions of rats with contusion SCI, which contributed to amelioration of functional deficits and the relief of contusion SCI. Therefore, it was concluded that upregulated expression of miR-378-3p in PC12 or N2A cells repressed the apoptosis of nerve cells, and the administration of miR-378-3p in model rats with contusion SCI improved neurological and motor functions.

Roles of miRNAs in spinal cord injury and potential therapeutic interventions

Spinal cord injury (SCI) affects approximately 200,000 individuals per year worldwide. There are more than 27 million people worldwide living with long-term disability due to SCI. Historically, it was thought that the central nervous system (CNS) had little ability for regeneration; however, more recent studies have demonstrated potential for repair within the CNS. Because of this, there exists a renewed interest in the discovery of novel approaches to promote regeneration in the CNS including the spinal cord. It is important to know the roles of the microRNAs (miRNAs) in modulation of pathogenesis in SCI and the potentials of the miRNA-based clinical interventions for controlling post-injury symptoms and improving functional recovery. The miRNAs, which are non-coding RNAs with an average of 22 nucleotides in length, are post-transcriptional gene regulators that cause degradation of the target mRNAs and thus negatively control their translation. This review article focuses on current research related to miRNAs and their roles in modulating SCI symptoms, asserting that miRNAs contribute to critical post-SCI molecular processes including neuroplasticity, functional recovery, astrogliosis, neuropathic pain, inflammation, and apoptosis. In particular, miR-96 provides a promising therapeutic opportunity to improve the outcomes of clinical interventions, including the way SCI injuries are evaluated and treated.