The role of Wnt/mTOR signaling in spinal cord injury

Blueprints for healing: central nervous system regeneration in zebrafish and neonatal mice

In adult mammals, including humans, neurons, and axons in the brain and spinal cord are inherently incapable of regenerating after injury. Studies of animals with innate capacity for regeneration are providing valuable insights into the mechanisms driving tissue healing. The aim of this review is to summarize recent data on regeneration mechanisms in the brain and spinal cord of zebrafish and neonatal mice. We infer that elucidating these mechanisms and understanding how and why they are lost in adult mammals will contribute to the development of strategies to promote central nervous system regeneration.

Tibetan medicine Wuwei Leze powder improves inflammatory mediated metabolic disorders and bone damage in collagen-induced arthritis rats

ETHNOPHARMACOLOGICAL RELEVANCE

Wuwei Leze Powder (WLP, སླྱེ་ཏྱེསལྔ་ཐང།) is a classic Traditional Tibetan medicine formula, which has certain clinical efficacy for rheumatoid arthritis (RA). Nevertheless, the pharmacological effects and potential therapeutic mechanisms of WLP on RA remain unclear.

AIM OF THE STUDY

The present study aimed to investigate the potential pharmacological mechanisms of anti- RA effect of WLP.

MATERIALS AND METHODS

The chemical constituents of WLP were analyzed by UPLC-Q-TOF-MS. A collagen-induced arthritis (CIA) rat model was established to evaluate the swelling, arthritis index. Pathohistological staining and micro-CT were employed to evaluate the therapeutic effects of WLP. Subsequently, serum metabolomic analysis was conducted to elucidate the potential biomarkers and pathways. Finally, an enzyme-linked immunosorbent assay, along with immunofluorescence, RT-qPCR and western blotting, were utilized to verify the anti-RA mechanism of WLP.

RESULTS

A total of 109 chemical constituents from WLP were identified by UPLC-Q-TOF-MS. WLP reduced paw swelling, arthritis scores and organ index in the CIA rat model. Histopathological staining and micro-CT observed WLP possesses both anti-inflammatory and bone-protective properties. Subsequently, serum metabolomics identified 12 potential biomarkers, mainly related to amino acid metabolism and the mTOR signaling pathway. ELISA showed that WLP can regulate abnormal levels of inflammatory cytokines (IL-4, IL-10, TNF-α, IL-6, INF-γ and IL-17). Immunofluorescence demonstrated that WLP could regulate the expression of MMP-1, MMP-9, MMP-13 and RANKL. The effect of WLP on the expression of Wnt3a, Wnt10b, β-catenin, RANKL, OPG, p65 and MMP-9 were verified using RT-qPCR and WB, thereby elucidating the anti-arthritis mechanism of WLP.

CONCLUSION

The possible mechanism underlying the anti-RA of WLP involves the downregulation of the Wnt/RANKL/NF-κB axis, the restoration of abnormal host metabolite levels, the suppression of synovitis responses, and the attenuation of bone erosion. Considering the high variability of plant materials, the present study takes a batch of WLP as an example, which inevitably has limitations.

Pectolinarin Promotes Functional Recovery after Spinal Cord Injury by Regulating Microglia Polarization Through the PI3K/AKT Signaling Pathway

After spinal cord injury (SCI), microglia polarization plays an important role in spinal cord recovery and axon regeneration. In this study, we conducted mRNA microarrays to identify genes associated with different microglial phenotypes. The results showed a correlation between microglial polarization and the PI3K/AKT signaling pathway, a key regulator of inflammatory responses. In addition, we found that Pectolinarin (PTR) could effectively inhibit lipopolysaccharide (LPS)-induced M1 polarization of microglia and facilitate their transition to the M2 phenotype by directly suppressing the PI3K/AKT signaling pathway. In our established animal model of SCI, it was confirmed that PTR treatment induced microglial polarization towards the M2 phenotype, resulting in reduced fibrous scar formation, enhanced myelin reconstitution, and improved axonal regeneration. In conclusion, targeting the PI3K/AKT signaling pathway with PTR presents a promising new direction for SCI treatment.

Recent advances on signaling pathways and their inhibitors in spinal cord injury

Spinal cord injury (SCI) is a serious and disabling central nervous system injury. Its complex pathological mechanism can lead to sensory and motor dysfunction. It has been reported that signaling pathway plays a key role in the pathological process and neuronal recovery mechanism of SCI. Such as PI3K/Akt, MAPK, NF-κB, and Wnt/β-catenin signaling pathways. According to reports, various stimuli and cytokines activate these signaling pathways related to SCI pathology, thereby participating in the regulation of pathological processes such as inflammation response, cell apoptosis, oxidative stress, and glial scar formation after injury. Activation or inhibition of relevant pathways can delay inflammatory response, reduce neuronal apoptosis, prevent glial scar formation, improve the microenvironment after SCI, and promote neural function recovery. Based on the role of signaling pathways in SCI, they may be potential targets for the treatment of SCI. Therefore, understanding the signaling pathway and its inhibitors may be beneficial to the development of SCI therapeutic targets and new drugs. This paper mainly summarizes the pathophysiological process of SCI, the signaling pathways involved in SCI pathogenesis, and the potential role of specific inhibitors/activators in its treatment. In addition, this review also discusses the deficiencies and defects of signaling pathways in SCI research. It is hoped that this study can provide reference for future research on signaling pathways in the pathogenesis of SCI and provide theoretical basis for SCI biotherapy.

Applications of Stem Cell-Derived Extracellular Vesicles in Nerve Regeneration

Extracellular vesicles (EVs), including exosomes, microvesicles, and other lipid vesicles derived from cells, play a pivotal role in intercellular communication by transferring information between cells. EVs secreted by progenitor and stem cells have been associated with the therapeutic effects observed in cell-based therapies, and they also contribute to tissue regeneration following injury, such as in orthopaedic surgery cases. This review explores the involvement of EVs in nerve regeneration, their potential as drug carriers, and their significance in stem cell research and cell-free therapies. It underscores the importance of bioengineers comprehending and manipulating EV activity to optimize the efficacy of tissue engineering and regenerative therapies.

Therapeutic Potential of Natural Compounds from Herbs and Nutraceuticals in Alleviating Neurological Disorders: Targeting the Wnt Signaling Pathway

As an important signaling pathway in multicellular eukaryotes, the Wnt signaling pathway participates in a variety of physiological processes. Recent studies have confirmed that the Wnt signaling pathway plays an important role in neurological disorders such as stroke, Alzheimer's disease, and Parkinson's disease. The regulation of Wnt signaling by natural compounds in herbal medicines and nutraceuticals has emerged as a potential strategy for the development of new drugs for neurological disorders. Purpose: The aim of this review is to evaluate the latest research results on the efficacy of natural compounds derived from herbs and nutraceuticals in the prevention and treatment of neurological disorders by regulating the Wnt pathway in vivo and in vitro. A manual and electronic search was performed for English articles available from PubMed, Web of Science, and ScienceDirect from the January 2010 to February 2023. Keywords used for the search engines were "natural products,″ "plant derived products,″ "Wnt+ clinical trials,″ and "Wnt+,″ and/or paired with "natural products″/″plant derived products", and "neurological disorders." A total of 22 articles were enrolled in this review, and a variety of natural compounds from herbal medicine and nutritional foods have been shown to exert therapeutic effects on neurological disorders through the Wnt pathway, including curcumin, resveratrol, and querctrin, etc. These natural products possess antioxidant, anti-inflammatory, and angiogenic properties, confer neurovascular unit and blood-brain barrier integrity protection, and affect neural stem cell differentiation, synaptic formation, and neurogenesis, to play a therapeutic role in neurological disorders. In various in vivo and in vitro studies and clinical trials, these natural compounds have been shown to be safe and tolerable with few adverse effects. Natural compounds may serve a therapeutic role in neurological disorders by regulating the Wnt pathway. This summary of the research progress of natural compounds targeting the Wnt pathway may provide new insights for the treatment of neurological disorders and potential targets for the development of new drugs.

Key Mutant Genes and Biological Pathways Involved in Aspirin Resistance in the Residents of the Chinese Plateau Area

INTRODUCTION

Aspirin is used to prevent and treat cardiovascular diseases; however, some patients develop aspirin resistance.

AIM

We aimed to explore the potential molecular mechanisms underlying aspirin resistance in people living in the Chinese plateau area.

METHODS

In total, 91 participants receiving aspirin treatment from the Qinghai plateau area were divided into the aspirin resistance and aspirin sensitivity groups. Genotyping was performed using the Sequence MASSarray. Differentially mutated genes between the two groups were analyzed using MAfTools. The annotation of differentially mutated genes was conducted based on the Metascape database.

RESULTS AND DISCUSSION

In total, 48 differential SNP and 22 differential InDel mutant genes between the aspirin resistance and aspirin sensitivity groups were screened using Fisher's exact test (P < 0.05). After the χ2 test, a total of 21 SNP mutant genes, including ZFPL1 and TLR3, and 19 InDel mutant genes were found to be differentially expressed between the two groups (P < 0.05). Functional analysis revealed that these differential SNP mutations were mainly enriched in aspirin resistance pathways, such as the Wnt signaling pathway. Furthermore, these genes were related to many diseases, including various aspirin indications.

CONCLUSION

This study identified several genes and pathways that could be involved in arachidonic acid metabolic processes and aspirin resistance progression, which will provide a theoretical understanding of the molecular mechanism of aspirin resistance.

The Role of Resveratrol on Spinal Cord Injury: from Bench to Bedside

Spinal cord injury (SCI) is a severe and disabling injury of the central nervous system, with complex pathological mechanisms leading to sensory and motor dysfunction. Pathological processes, such as oxidative stress, inflammatory response, apoptosis, and glial scarring are important factors that aggravate SCI. Therefore, the inhibition of these pathological processes may contribute to the treatment of SCI. Currently, the pathogenesis of SCI remains under investigation as SCI treatment has not progressed considerably. Resveratrol, a natural polyphenol with anti-inflammatory and antioxidant properties, is considered a potential therapeutic drug for various diseases and plays a beneficial role in nerve damage. Preclinical studies have confirmed that signaling pathways are closely related to the pathological processes in SCI, and resveratrol is believed to exert therapeutic effects in SCI by activating the related signaling pathways. Based on current research on the pathways of resveratrol and its role in SCI, resveratrol may be a potentially effective treatment for SCI. This review summarizes the role of resveratrol in promoting the recovery of nerve function by regulating oxidative stress, inflammation, apoptosis, and glial scar formation in SCI through various mechanisms and pathways, as well as the deficiency of resveratrol in SCI research and the current and anticipated research trends of resveratrol. In addition, this review provides a background for further studies on the molecular mechanisms of SCI and the development of potential therapeutic agents. This information could also help clinicians understand the known mechanisms of action of resveratrol and provide better treatment options for patients with SCI.

Rehabilitation: Neurogenic Bone Loss after Spinal Cord Injury

Osteoporosis is a common skeletal disorder which can severely limit one's ability to complete daily tasks due to the increased risk of bone fractures, reducing quality of life. Spinal cord injury (SCI) can also result in osteoporosis and sarcopenia. Most individuals experience sarcopenia and osteoporosis due to advancing age; however, individuals with SCI experience more rapid and debilitating levels of muscle and bone loss due to neurogenic factors, musculoskeletal disuse, and cellular/molecular events. Thus, preserving and maintaining bone mass after SCI is crucial to decreasing the risk of fragility and fracture in vulnerable SCI populations. Recent studies have provided an improved understanding of the pathophysiology and risk factors related to musculoskeletal loss after SCI. Pharmacological and non-pharmacological therapies have also provided for the reduction in or elimination of neurogenic bone loss after SCI. This review article will discuss the pathophysiology and risk factors of muscle and bone loss after SCI, including the mechanisms that may lead to muscle and bone loss after SCI. This review will also focus on current and future pharmacological and non-pharmacological therapies for reducing or eliminating neurogenic bone loss following SCI.

Sexually dimorphic extracellular vesicle responses after chronic spinal cord injury are associated with neuroinflammation and neurodegeneration in the aged brain

BACKGROUND

Medical advances have made it increasingly possible for spinal cord injury (SCI) survivors to survive decades after the insult. But how SCI affects aging changes and aging impacts the injury process have received limited attention. Extracellular vesicles (EVs) are recognized as critical mediators of neuroinflammation after CNS injury, including at a distance from the lesion site. We have previously shown that SCI in young male mice leads to robust changes in plasma EV count and microRNA (miR) content. Here, our goal was to investigate the impact of biological sex and aging on EVs and brain after SCI.

METHODS

Young adult age-matched male and female C57BL/6 mice were subjected to SCI. At 19 months post-injury, total plasma EVs were isolated by ultracentrifugation and characterized by nanoparticle tracking analysis (NTA). EVs miR cargo was examined using the Fireplex® assay. The transcriptional changes in the brain were assessed by a NanoString nCounter Neuropathology panel and validated by Western blot (WB) and flow cytometry (FC). A battery of behavioral tests was performed for assessment of neurological function.

RESULTS

Transcriptomic changes showed a high number of changes between sham and those with SCI. Sex-specific changes were found in transcription networks related to disease association, activated microglia, and vesicle trafficking. FC showed higher microglia and myeloid counts in the injured tissue of SCI/Female compared to their male counterparts, along with higher microglial production of ROS in both injured site and the brain. In the latter, increased levels of TNF and mitochondrial membrane potential were seen in microglia from SCI/Female. WB and NTA revealed that EV markers are elevated in the plasma of SCI/Male. Particle concentration in the cortex increased after injury, with SCI/Female showing higher counts than SCI/Male. EVs cargo analysis revealed changes in miR content related to injury and sex. Behavioral testing confirmed impairment of cognition and depression at chronic time points after SCI in both sexes, without significant differences between males and females.

CONCLUSIONS

Our study is the first to show sexually dimorphic changes in brain after very long-term SCI and supports a potential sex-dependent EV-mediated mechanism that contributes to SCI-induced brain changes.

The efficacy of intrathecal methyl-prednisolone for acute spinal cord injury: A pilot study

Study design

Randomized clinical trial.

Objectives

To evaluate the safety and effectiveness of intrathecal methyl-prednisolone compared to intravenous methyl-prednisolone in acute spinal cord injuries.

Setting

Imam Reza Hospital, Tabriz University of Medical Sciences.

Methods

Patients meeting our inclusion and exclusion criteria were enrolled in the study and divided randomly into two treatment arms: intrathecal and intravenous. Standard spinal cord injury care (including surgery) was given to each patient based on our institutional policy. Patients were then assessed for neurological status (based on ASIA scores, Frankel scores) and complications for six months and compared to baseline status after injury. To better understand the biological bases of methyl-prednisolone on spinal cord injuries, we measured two biomarkers for oxidative stress (serum malondialdehyde and total antioxidant capacity) in these patients at arrival and day three after injury.

Results

The present study showed no significant difference between the treatment arms in neurological status (sensory scores or motor scores) or complications. However, the within-group analysis showed improvement in neurological status in each treatment arm within six months. Serum malondialdehyde and total antioxidant capacity were analyzed, and no significant difference between the groups was seen.

Conclusion

This is the first known clinical trial investigating the effect of intrathecal MP in acute SCI patients. Our finding did not show any significant differences in complication rates and neurological outcomes between the two study arms. Further studies should be conducted to define the positive and negative effects of this somehow novel technique in different populations as well.

Activation of Wnt/Beta-Catenin Signaling Pathway as a Promising Therapeutic Candidate for Cerebral Ischemia/Reperfusion Injury

Stroke is one of the leading causes of mortality, and survivors experience serious neurological and motor behavioral deficiencies. Following a cerebral ischemic event, substantial alterations in both cellular and molecular activities occur because of ischemia/reperfusion injury. Wnt signaling is an evolutionarily conserved signaling pathway that has been manifested to play a key role in embryo development and function maintenance in adults. Overactivation of Wnt signaling has previously been investigated in cancer-based research studies. Recently, abnormal Wnt signaling activity has been observed in ischemic stroke, which is accompanied by massive blood–brain barrier (BBB) disruption, neuronal apoptosis, and neuroinflammation within the central nervous system (CNS). Significant therapeutic effects were observed after reactivating the adynamic signaling activity of canonical Wnt signaling in different cell types. To better understand the therapeutic potential of Wnt as a novel target for stroke, we reviewed the role of Wnt signaling in the pathogenesis of stroke in different cell types, including endothelial cells, neurons, oligodendrocytes, and microglia. A comprehensive understanding of Wnt signaling among different cells may help to evaluate its potential value for the development of novel therapeutic strategies based on Wnt activation that can ameliorate complications and improve functional rehabilitation after ischemic stroke.