Protective effect of epigenetic silencing of CyclinD1 against spinal cord injury using bone marrow-derived mesenchymal stem cells in rats

Injectable and Photocurable Gene Scaffold Facilitates Efficient Repair of Spinal Cord Injury

RNA interference-based gene therapy has led to a strategy for spinal cord injury (SCI) therapy. However, there have been high requirements regarding the optimal gene delivery vector for siRNA-based SCI gene therapy. Here, we developed an injectable and photocurable lipid nanoparticle GelMA (PLNG) hydrogel scaffold for controlled dual siRNA delivery at the SCI wound site. The prepared PLNG scaffold could efficiently protect and retain the bioactivity of the siRNA nanocomplex. It facilitated sustainable siRNA release along with degradation in 7 days. After loading dual siRNA targeting phosphatase and tensin homologue (PTEN) and macrophage migration inhibitory factor (MIF) simultaneously, the locally administered siRNAs/PLNG scaffold efficiently improved the Basso mouse scale (BMS) score and recovered ankle joint movement and plantar stepping after treatment with only three doses. We further proved that the siRNAs/PLNG scaffold successfully regulated the activities of neurons, microglia, and macrophages, thus promoting neuron axon regeneration and remyelination. The protein array results suggested that the siRNAs/PLNG scaffold could increase the expression of growth factors and decrease the expression of inflammatory factors to regulate neuroinflammation in SCI and create a neural repair environment. Our results suggested that the PLNG scaffold siRNA delivery system is a potential candidate for siRNA-based SCI therapy.

Subacute and Chronic Spinal Cord Injury: A Scoping Review of Epigenetics and Secondary Health Conditions

Background

Epigenetics studies the impact of environmental and behavioral factors on stable phenotypic changes; however, the state of the science examining epigenomic mechanisms of regulation related to secondary health conditions (SHCs) and neuroepigenetics in chronic spinal cord injury (SCI) remain markedly underdeveloped.

Objective

This scoping review seeks to understand the state of the science in epigenetics and secondary complications following SCI.

Methods

A literature search was conducted, yielding 277 articles. The inclusion criteria were articles (1) investigating SCI and (2) examining epigenetic regulation as part of the study methodology. A total of 23 articles were selected for final inclusion.

Results

Of the 23 articles 52% focused on histone modification, while 26% focused on DNA methylation. One study had a human sample, while the majority sampled rats and mice. Primarily, studies examined regeneration, with only one study looking at clinically relevant SHC, such as neuropathic pain.

Discussion

The findings of this scoping review offer exciting insights into epigenetic and neuroepigenetic application in SCI research. Several key genes, proteins, and pathways emerged across studies, suggesting the critical role of epigenetic regulation in biological processes. This review reinforced the dearth of studies that leverage epigenetic methods to identify prognostic biomarkers in SHCs. Preclinical models of SCI were genotypically and phenotypically similar, which is not reflective of the heterogeneity found in the clinical population of persons with SCI. There is a need to develop better preclinical models and more studies that examine the role of genomics and epigenomics in understanding the diverse health outcomes associated with traumatic SCI.

MiR-31 improves spinal cord injury in mice by promoting the migration of bone marrow mesenchymal stem cells

Background

Stem cell transplantation therapy is a potential approach for the repair of spinal cord injuries and other neurodegenerative diseases, but its effectiveness is hampered by the low rate of targeted migration of cells to the area of injury. The aim of this study was to investigate the effects of miR-31 on the migration of bone marrow mesenchymal stem cells (BMSCs) and the regulation of MMP-2 and CXCR4 expression in vitro and in vivo.

Methods

eGFP-expressing BMSCs were isolated and cultured for subsequent experiments. The experiments were divided into three groups: control group, miR-31agomir group, and miR-31antagomir group. Proliferation was analyzed using CCK-8 and flow cytometry; cell migration in vitro was analyzed using wound-healing and transwell assays. The mouse SCI model was prepared by the impact method, and cells were transplanted (3 groups, 12 per group). Relevant inflammatory factors were detected by ELISA. The BMS score was used to evaluate the functional recovery of the mouse spinal cord and the frozen section was used to analyze the cell migration ability in vivo. The in vitro and in vivo expression levels of MMP-2 and CXCR4 were evaluated by Western blot and immunohistochemical staining.

Results

In vitro experiments showed that cells in the miR-31agomir group exhibited enhanced cell proliferation (P<0.05, P<0.001) and migration (P<0.001) and upregulated protein expression levels of CXCR4 (P<0.01) and MMP-2 (P<0.001) compared with cells in the control group. The results of in vivo experiments showed that the expression of pro-inflammatory factors was reduced after cell transplantation treatment. Cells in the miR-31agomir group showed enhanced cell-targeted migration ability (P<0.001), improved the function of damaged tissues (P<0.001), and upregulated CXCR4 and MMP-2 expression compared to the control group (P<0.001).

Conclusion

Our experiment demonstrated that miR-31 could promote the migration of BMSCs and miR-31 could repair and improve the function of damaged tissues in SCI.

Using Network Pharmacology to Systematically Decipher the Potential Mechanisms of Jisuikang in the Treatment of Spinal Cord Injury

Objective

To identify the potential pharmacological targets of Jisuikang (JSK) for the treatment of spinal cord injury (SCI) using network pharmacology.

Methods

The bioactive compounds of JSK herbs and their corresponding potential SCI targets were obtained from three traditional Chinese medicine (TCM) databases. SCI-related therapeutic target genes were obtained from the Comparative Toxicogenomics Database and the GeneCards Database. The common target genes between the JSK compounds and SCI-related therapeutic targets were screened using GO/KEGG functional enrichment and protein-protein interaction (PPI) analyses to identify hub genes and their categories of biological function. Gene expression distribution and receiver operating characteristic curve (ROC) analyses were used to identify probable SCI-related target genes. Molecular docking was used to quantify molecular interactions between target genes and the bioactive compounds of JSK.

Results

A total of 183 JSK bioactive compounds and 197 target genes for the treatment of SCI were screened and assessed. The target genes were enriched primarily in drug metabolism and in inflammation-related biological processes. Ten genes with statistical significance were identified as therapeutic SCI-related target genes of JSK. Molecular docking experiments demonstrated that the proteins of these 10 genes docked with binding energies of less than −5 kcal/mol with the bioactive compounds in JSK.

Conclusion

This study showed that the anti-SCI effects of JSK may be mediated through numerous bioactive components, multiple gene targets, and inflammation-related pathways and provided potential novel targets for directed therapies for treating SCI. These results provide a foundation for further experimental investigations into treatment options for SCI.

Cotransplantation with RADA16-PRG-Self-Assembled Nanopeptide Scaffolds, Bone Mesenchymal Stem Cells and Brain-Derived Neurotrophic Factor-Adeno-Associated Virus Promote Functional Repair After Acute Spinal Cord Injury in Rats

We transplanted RADA16-PRG self-assembled nanopeptide scaffolds (SAPNSs), bone mesenchymal stem cells (BMSCs), and a brain-derived neurotrophic factor (BDNF)-expressing adeno-associated virus (AAV) into rats subjected to acute spinal cord injury (SCI) to investigate the effects of these transplantations on acute SCI repair and explore their mechanisms. Forty-eight SCI rats were randomly divided into four groups: BBR, BR, B, and NC groups. Seven and 28 days after SCI, evoked potentials (EPs) and BBB scores were assessed to evaluate the recovery of rats' motor behavior and sensory function after injury. HE and toluidine blue staining were performed to investigate the histological structure of the spinal cord tissue of rats from each group, and immunofluorescence staining was used to observe the red fluorescent protein (RFP) intensity of BMSCs and glial fibrillary acidic protein (GFAP) and neurofilament (NF) in the damaged area in each group. RT-PCR was utilized to detect the expression levels of the BDNF, GFAP, and neuron-specific enolase (NSE) genes in the injured area in each group. The results showed that cotransplantation of RADA16-PRG-SAPNs, BMSCs, and BDNF-AVV promoted the spinal cord's motor and sensory function of SCI rats; increased levels of BMSCs, inhabited glial cells proliferation, and promoted neurons proliferations in the injured area; and increased NF, BDNF, and NSE levels and decreased its GFAP in the injured area. Thus, cotransplantation of RADA16-PRG-SAPNS, BMSCs, and BDNF-AAV can prolong the survival time of BMSCs in rats, reduce the postoperative scarring caused by glial proliferation, and promote the migration and proliferation of neurons in the injured area, resulting in the promotion of functional repair after acute SCI.

Future Perspectives in Spinal Cord Repair: Brain as Saviour? TSCI with Concurrent TBI: Pathophysiological Interaction and Impact on MSC Treatment

Traumatic spinal cord injury (TSCI), commonly caused by high energy trauma in young active patients, is frequently accompanied by traumatic brain injury (TBI). Although combined trauma results in inferior clinical outcomes and a higher mortality rate, the understanding of the pathophysiological interaction of co-occurring TSCI and TBI remains limited. This review provides a detailed overview of the local and systemic alterations due to TSCI and TBI, which severely affect the autonomic and sensory nervous system, immune response, the blood-brain and spinal cord barrier, local perfusion, endocrine homeostasis, posttraumatic metabolism, and circadian rhythm. Because currently developed mesenchymal stem cell (MSC)-based therapeutic strategies for TSCI provide only mild benefit, this review raises awareness of the impact of TSCI-TBI interaction on TSCI pathophysiology and MSC treatment. Therefore, we propose that unravelling the underlying pathophysiology of TSCI with concomitant TBI will reveal promising pharmacological targets and therapeutic strategies for regenerative therapies, further improving MSC therapy.

Progress in Stem Cell Therapy for Spinal Cord Injury

Background

Spinal cord injury (SCI) is one of the serious neurological diseases that occur in young people with high morbidity and disability. However, there is still a lack of effective treatments for it. Stem cell (SC) treatment of SCI has gradually become a new research hotspot over the past decades. This article is aimed at reviewing the research progress of SC therapy for SCI.

Methods

Review the literature and summarize the effects, strategies, related mechanisms, safety, and clinical application of different SC types and new approaches in combination with SC in SCI treatment.

Results

A large number of studies have focused on SC therapy for SCI, most of which showed good effects. The common SC types for SCI treatment include mesenchymal stem cells (MSCs), hematopoietic stem cells (HSCs), neural stem cells (NSCs), induced pluripotent stem cells (iPSCs), and embryonic stem cells (ESCs). The modes of treatment include in vivo and in vitro induction. The pathways of transplantation consist of intravenous, transarterial, nasal, intraperitoneal, intrathecal, and intramedullary injections. Most of the SC treatments for SCI use a number of cells ranging from tens of thousands to millions. Early or late SC administration, application of immunosuppressant or not are still controversies. Potential mechanisms of SC therapy include tissue repair and replacement, neurotrophy, and regeneration and promotion of angiogenesis, antiapoptosis, and anti-inflammatory. Common safety issues include thrombosis and embolism, tumorigenicity and instability, infection, high fever, and even death. Recently, some new approaches, such as the pharmacological activation of endogenous SCs, biomaterials, 3D print, and optogenetics, have been also developed, which greatly improved the application of SC therapy for SCI.

Conclusion

Most studies support the effects of SC therapy on SCI, while a few studies do not. The cell types, mechanisms, and strategies of SC therapy for SCI are very different among studies. In addition, the safety cannot be ignored, and more clinical trials are required. The application of new technology will promote SC therapy of SCI.

Virtual Screening of Potential Anti-fatigue Mechanism of Polygonati Rhizoma Based on Network Pharmacology

BACKGROUND AND OBJECTIVE

A large number of people are facing the danger of fatigue due to the fast-paced lifestyle. Fatigue is common in some diseases, such as cancer. The mechanism of fatigue is not definite. Traditional Chinese medicine is often used for fatigue, but the potential mechanism of Polygonati Rhizoma (PR) is still not clear. This study attempts to explore the potential anti-fatigue mechanism of Polygonati Rhizoma through virtual screening based on network pharmacology.

METHODS

The candidate compounds of PR and the known targets of fatigue are obtained from multiple professional databases. PharmMapper Server is designed to identify potential targets for the candidate compounds. We developed a Herbal medicine-Compound-Disease-Target network and analyzed the interactions. Protein-protein interaction network is developed through the Cytoscape software and analyzed by topological methods. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment are carried out by DAVID Database. Finally, we develop Compound-Target-Pathway network to illustrate the anti-fatigue mechanism of PR.

RESULTS

This approach identified 12 active compounds and 156 candidate targets of PR. The top 10 annotation terms for GO and KEGG were obtained by enrichment analysis with 35 key targets. The interaction between E2F1 and PI3K-AKT plays a vital role in the anti-fatigue effect of PR due to this study.

CONCLUSION

This study demonstrates that PR has multi-component, multi-target and multipathway effects.