Acidic Fibroblast Growth Factor in Spinal Cord Injury

Potential therapeutic targets for Alzheimer's disease: Fibroblast growth factors and their regulation of ferroptosis, pyroptosis and autophagy

Alzheimer's disease (AD) is a progressively worsening neurodegenerative disorder characterized primarily by the deposition of amyloid beta (Aβ) plaques in the brain and the abnormal aggregation of tau protein forming neurofibrillary tangles. These pathological changes lead to impaired neuronal function and cell death, subsequently affecting the structure and function of the brain. Fibroblast growth factors (FGFs) are a group of proteins that play crucial roles in various biological processes, including cell proliferation, differentiation, and survival. This article reviews the expression and regulation of FGFs in the central nervous system and how they affect neuronal survival, as well as the changes in FGF signaling pathways and its regulation of programmed cell death in AD. It particularly focuses on the impact of FGF1, FGF2, FGF21, other members of the FGF family, and FGFR on the pathophysiological mechanisms of AD. The potential of the PI3K/AKT/GSK-3β, Wnt/β-catenin, and NF-κB signaling pathways as targets for AD treatment is also discussed. Furthermore, the relationship between FGF-regulated ferroptosis, Pyroptosis and Autophagy and AD is explored, along with the role of these mechanisms in improving the progression of AD.

Sodium Alginate/Poly (Acrylicacid) Hydrogel Composite, Potential Carrier for Fibroblast Growth Factor1 (FGF1) Delivery

Fibroblast growth factor1 is a powerful signaling molecule that plays a critical role in injury repair of diverse tissue by stimulating cell growth and angiogenesis. FGF1 has significant role in the cell fate and regulating inflammation with short half-life and poor in vivo stability. The encapsulation of the growth factor in the hydrogel led to peptide protect from the degradation and/or immune recognition and enable controlled drug delivery over a longer period of time. The aim of this study is to develop and evaluate a hydrogel carrier with adjustable release rate while maintaining bioactivity of FGF1. Here we describe an optimal ratio of sodium alginate and polyacrylic acid without additional cross linker containing optimum amount of FGF1 with the potential of sustained release to be used as a therapeutic agent. The carrier was characterized by FTIR, contact angle and swelling ratio. The activity of FGF1 after release from the hydrogel was confirmed by ELISA and Western blot. Further assessment of genes related to inflammation were evaluated by RTPCR. This hydrogel is able to deliver growth factors by restricting the essential proteins within the matrix to prevent rapid proteolysis and explosive release and is therefore widely applicable.

Recombinant Acidic Fibroblast Growth Factor Facilitates Motor Recovery and Reduces Myelomalacia in Traumatic American Spinal Injury Association Impairment Scale A Spinal Cord Injured Patients

This study aims to evaluate the potential benefits of treating spinal cord injury (SCI) patients with acidic fibroblast growth factor (aFGF), a potent neurotrophic factor that preserves neuronal survival. The study involved 12 tetraplegic patients with American Spinal Injury Association Impairment Scale (AIS) Grade A SCI who were randomly assigned to receive either a recombinant human aFGF or a placebo every 4 weeks for three doses. Participants underwent comprehensive evaluations of medical, neurological, and functional parameters at baseline and every 4 weeks after the first dose until the 48th week. The first dose was administered directly to the injury site during surgery within 6 weeks of the SCI, while the subsequent two doses were administered via lumbar puncture with a 4-week interval. The results revealed promising beneficial effects of aFGF on AIS Grade A SCI patients. The study report highlights aFGF's potential to expedite motor recovery in complete SCI patients and significantly increase the probability of a 10-point improvement when compared to the placebo group (odds ratio = 6.06, p = 0.0004). Furthermore, aFGF treatment exhibited a significant reduction (p < 0.01) in the incidence or exacerbation rate of myelomalacia, a known secondary complication following SCIs.

Sustained activation of the FGF1-MEK-ERK pathway inhibits proliferation, invasion and migration and enhances radiosensitivity in mouse angiosarcoma cells

Angiosarcoma is a rare refractory soft-tissue tumor with a poor prognosis and is treated by radiotherapy. The fibroblast growth factor 1 (FGF1) mutant, with enhanced thermostability due to several substituted amino acids, inhibits angiosarcoma cell metastasis, yet the mechanism of action is unclear. This study aims to clarify the FGF1 mutant mechanism of action using ISOS-1 mouse angiosarcoma cells. The wild-type FGF1 or FGF1 mutant was added to ISOS-1 cells and cultured, evaluating cell numbers over time. The invasive and migratory capacity of ISOS-1 cells was assessed by transwell analysis. ISOS-1 cell radiosensitivity was assessed by colony formation assay after X-ray irradiation. To examine whether mitogen-activated protein kinase (MEK) inhibitor counteracts the FGF1 mutant effects, a combination of MEK inhibitor and FGF1 mutant was added to ISOS-1 cells and cultured. The FGF1 mutant was observed to inhibit ISOS-1 cell proliferation, invasion and migration by sustained FGF1 signaling activation. A MEK inhibitor suppressed the FGF1 mutant-induced inhibition of proliferation, invasion and migration of ISOS-1 cells. Furthermore, the FGF1 mutant enhanced radiosensitivity of ISOS-1 cells, but MEK inhibition suppressed the increased radiosensitivity. In addition, we found that the FGF1 mutant strongly inhibits actin polymerization, suggesting that actin cytoskeletal dynamics are closely related to ISOS-1 cell radiosensitivity. Overall, this study demonstrated that in ISOS-1 cells, the FGF1 mutant inhibits proliferation, invasion and migration while enhancing radiosensitivity through sustained activation of the MEK-mediated signaling pathway.

Pathophysiology of Spinal Cord Injury and Tissue Engineering Approach for Its Neuronal Regeneration: Current Status and Future Prospects

A spinal cord injury (SCI) is a very debilitating condition causing loss of sensory and motor function as well as multiple organ failures. Current therapeutic options like surgery and pharmacotherapy show positive results but are incapable of providing a complete cure for chronic SCI symptoms. Tissue engineering, including neuroprotective or growth factors, stem cells, and biomaterial scaffolds, grabs attention because of their potential for regeneration and ability to bridge the gap in the injured spinal cord (SC). Preclinical studies with tissue engineering showed functional recovery and neurorestorative effects. Few clinical trials show the safety and efficacy of the tissue engineering approach. However, more studies should be carried out for potential treatment modalities. In this review, we summarize the pathophysiology of SCI and its current treatment modalities, including surgical, pharmacological, and tissue engineering approaches following SCI in preclinical and clinical phases.

Transcription Profiling of a Revealed the Potential Molecular Mechanism of Governor Vessel Electroacupuncture for Spinal Cord Injury in Rats

OBJECTIVE

This study aimed to identify differentially expressed genes (DEGs) by transcriptome analysis to elucidate a potential mechanism by which governor vessel electroacupuncture (GV-EA) promotes neuronal survival, axonal regeneration, and functional recovery after complete transection spinal cord injury (SCI).

METHODS

Sham, control, or GV-EA group adult female Sprague Dawley rats underwent a complete transection SCI protocol. SCI area RNA-seq investigated the DEGs of coding and noncoding RNAs 7 days post-SCI. Gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) enrichment analyses were used to classify DEGs functions, to explain a possible molecular mechanism. Immunofluorescence and BBB (Basso, Beattie, and Bresnahan) score were used to verify a GV-EA treatment effect following SCI.

RESULTS

GV-EA treatment could regulate the expression of 173 mRNA, 260 lncRNA, and 153 circRNA genes among these DEGs resulted by SCI. GO enrichment analysis showed that the DEGs were most enriched in membrane, actin binding, and regulation of Toll-like receptor signaling pathway. KEGG pathway analysis showed enriched pathways (e.g. , Toll-like receptors, MAPK, Hippo signaling). According to the ceRNA network, miR-144-3p played a regulatory role by interacting with lncRNA and circRNA. GV-EA also promoted the injured spinal cord neuron survival, axonal regeneration, and functional improvement of hind limb locomotion.

CONCLUSION

Results of our RNA-seq suggest that post-SCI GV-EA may regulate characteristic changes in transcriptome gene expression, potential critical genes, and signaling pathways, providing clear directions for further investigation into the mechanism of GV-EA in subacute SCI treatment. Moreover, we found that GV-EA promotes neuronal survival, nerve fiber extension, and motor function recovery in subacute SCI.

Established and Emerging Therapies in Acute Spinal Cord Injury

Acute spinal cord injury (SCI) is devastating for patients and their caretakers and has an annual incidence of 20–50 per million people. Following initial assessment with appropriate physical examination and imaging, patients who are deemed surgical candidates should undergo decompression with stabilization. Earlier intervention can improve neurological recovery in the post-operative period while allowing earlier mobilization. Optimized medical management is paramount to improve outcomes. Emerging strategies for managing SCI in the acute period stem from an evolving understanding of the pathophysiology of the injury. General areas of focus include ischemia prevention, reduction of secondary injury due to inflammation, modulation of the cytotoxic and immune response, and promotion of cellular regeneration. In this article, we review established, emerging, and novel experimental therapies. Continued translational research on these methods will improve the feasibility of bench-to-bedside innovations in treating patients with acute SCI.

Synaptic Cell Adhesion Molecule 3 (SynCAM3) Deletion Promotes Recovery from Spinal Cord Injury by Limiting Glial Scar Formation

Synaptic cell adhesion molecules (SynCAMs) play an important role in the formation and maintenance of synapses and the regulation of synaptic plasticity. SynCAM3 is expressed in the synaptic cleft of the central nervous system (CNS) and is involved in the connection between axons and astrocytes. We hypothesized that SynCAM3 may be related to the astrocytic scar (glial scar, the most important factor of CNS injury treatment) through extracellular matrix (ECM) reconstitution. Thus, we investigated the influence of the selective removal of SynCAM3 on the outcomes of spinal cord injury (SCI). SynCAM3 knock-out (KO) mice were subjected to moderate compression injury of the lower thoracic spinal cord using wild-type (WT) (C57BL/6JJc1) mice as controls. Single-cell RNA sequencing analysis over time, quantitative real-time polymerase chain reaction (qRT-PCR) analysis, and immunohistochemistry (IHC) showed reduced scar formation in SynCAM3 KO mice compared to WT mice. SynCAM3 KO mice showed improved functional recovery from SCI by preventing the transformation of reactive astrocytes into scar-forming astrocytes, resulting in improved ECM reconstitution at four weeks after injury. Our findings suggest that SynCAM3 could be a novel therapeutic target for SCI.

Fabrication Techniques of Nerve Guidance Conduits for Nerve Regeneration

Neuronal loss and axonal degeneration after spinal cord injury or peripheral injury result in the loss of sensory and motor functions. Nerve regeneration is a complicated and medical challenge that requires suitable guides to bridge nerve injury gaps and restore nerve function. Due to the hostility of the microenvironment in the lesion, multiple conditions should be fulfilled to achieve improved functional recovery. Many nerve conduits have been fabricated using various natural and synthetic polymers. The design and material of the nerve guide conduits were carefully reviewed. A detailed review was conducted on the fabrication method of the nerve guide conduit for nerve regeneration. The typical fabrication methods used to fabricate nerve conduits are dip coating, solvent casting, micropatterning, electrospinning, and additive manufacturing. The advantages and disadvantages of the fabrication methods were reported, and research to overcome these limitations was reviewed. Extensive reviews have focused on the biological functions and in vivo performance of polymeric nerve conduits. In this paper, we emphasize the fabrication method of nerve conduits by polymers and their properties. By learning from the existing candidates, we can advance the strategies for designing novel polymeric systems with better properties for nerve regeneration.

An Assessment of Which Sociodemographic and Spinal Cord Injury-Specific Characteristics Influence Engagement With Experimental Therapies and Participation in Clinical Trials

Background: Although a number of experimental therapies for spinal cord injury (SCI) have recently emerged, few authors have examined the goals of individuals with SCI considering experimental therapies, and none have determined whether sociodemographic and injury-specific characteristics influence that engagement. Objectives: To determine (a) the goals of individuals with SCI who are considering experimental therapies; (b) whether sociodemographic factors, injury-specific characteristics, and concerns over adverse events influence those goals and/or participation in experimental therapies and clinical trials; and (c) whether people with SCI feel they have adequate information about experimental therapies and clinical trials. Methods: An online survey that yielded 364 responses. Results: Most respondents (83.7%) had sought information about experimental therapies, and just under half (47.8%) had received one. The most frequently cited functional goals were improvement in bowel and bladder function and elimination of dysreflexia (60.4%). Several goals were influenced by age and level and completeness of injury, and most respondents (93.4%) wanted more information about experimental therapies. Just over one-third (34.6%) of respondents had participated in a clinical trial, and nearly all (96.9%) wanted more information about them. Having received experimental therapies and participated in clinical trials was positively correlated with seeking SCI-specific care from an SCI specialist rather than from a primary care physician. Most (83.9%) respondents would avoid or be reluctant to engage with a medical center if they were made aware of harm done to trial participants. Conclusion: This work suggests that there are unmet information needs among people with SCI, specifically pertaining to experimental therapies and clinical trials. It also reveals that improved access to SCI specialists may enhance access to novel treatments and research efforts. Being made aware of harm to trial participants may influence the decision of individuals with SCI to seek care at or enroll in trials at these clinical sites.

Diamond Concept as Principle for the Development of Spinal Cord Scaffold: A Literature Review

INTRODUCTION: Spinal cord injury (SCI) has been bringing detrimental impacts on the affected individuals. However, not only that, it also brings a tremendous effect on the socioeconomic and health-care system. Treatment regimen and strategy for SCI patient have been under further research. DISCUSSION: The main obstacles of regeneration on neuronal structure are the neuroinflammatory process and poor debris clearance, causing a longer healing process and an extensive inflammation process due to this particular inflammatory process. To resolve all of the mentioned significant issues in SCIs neuronal regeneration, a comprehensive model is necessary to analyze each step of progressive condition in SCI. In this review, we would like to redefine a comprehensive concept of the “Diamond Concept” from previously used in fracture management to SCI management, which consists of cellular platform, cellular inductivity, cellular conductivity, and material integrity. The scaffolding treatment strategy for SCI has been widely proposed due to its flexibility. It enables the physician to combine another treatment method such as neuroprotective or neuroregenerative or both in one intervention. CONCLUSION: Diamond concept perspective in the implementation of scaffolding could be advantageous to increase the outcome of SCI treatment.

The Application of an Omentum Graft or Flap in Spinal Cord Injury

Background: Spinal cord injury (SCI) causes a primary injury at the lesion site and triggers a secondary injury and prolonged inflammation. There has been no definitive treatment till now. Promoting angiogenesis is one of the most important strategies for functional recovery after SCI. The omentum, abundant in blood and lymph vessels, possesses the potent ability of tissue regeneration. Methods: The present work examines the efficacy of autologous omentum, either as a flap (with vascular connection intact) or graft (severed vascular connection), on spinal nerve regeneration. After contusive SCI in rats, a thin sheath of omentum was grafted to the injured spinal cord. Results: Omental graft improved behavior scores significantly from the 3rd to 6th week after injury (6th week, 5.5 ± 0.5 vs. 8.6 ± 1.3, p < 0.05). Furthermore, the reduction in cavity and the preservation of class III β-tubulin-positive nerve fibers in the injury area was noted. Next, the free omental flap was transposed to a completely transected SCI in rats through a pre-implanted tunnel. The flap remained vascularized and survived well several weeks after the operation. At 16 weeks post-treatment, SCI rats with omentum flap treatment displayed the preservation of significantly more nerve fibers (p < 0.05) and a reduced injured cavity, though locomotor scores were similar. Conclusions: Taken together, the findings of this study indicate that treatment with an omental graft or transposition of an omental flap on an injured spinal cord has a positive effect on nerve protection and tissue preservation in SCI rats. The current data highlight the importance of omentum in clinical applications.

Reduction in post-spinal cord injury spasticity by combination of peripheral nerve grafting and acidic fibroblast growth factor infusion in monkeys

OBJECTIVE

Spasticity is a frequent complication after spinal cord injury (SCI), but the existing therapies provide only limited relief and are associated with adverse reactions. Therefore, we aimed to develop a novel strategy to ameliorate the spasticity induced by SCI.

METHODS

This nonrandomized controlled study used a repeated measurement design. The study involved four monkeys, two of which served as controls and only underwent spinal cord hemisection surgery at the T8 spine level. The other two monkeys underwent transplantation of sural nerve segments into the injured sites and long-term infusion of acidic fibroblast growth factor (aFGF). All monkeys received postoperative exercise training and therapy.

RESULTS

The combined therapy substantially reduced the spasticity in leg muscle tone, patella tendon reflex, and fanning of toes. Although all monkeys showed spontaneous recovery of function over time, the recovery in the controls reached a plateau and started to decline after 11 weeks.

CONCLUSIONS

The combination of peripheral nerve grafting and aFGF infusion may serve as a complementary approach to reduce the signs of spasticity in patients with SCI.

Biomaterials and strategies for repairing spinal cord lesions

Spinal cord injury (SCI) causes intractable disease and leads to inevitable physical, financial, and psychological burdens on patients and their families. SCI is commonly divided into primary and secondary injury. Primary injury occurs upon direct impact to the spinal cord, which leads to cell necrosis, axon disruption, and vascular loss. This triggers pathophysiological secondary injury, which has several phases: acute, subacute, intermediate, and chronic. These phases are dependent on post-injury time and pathophysiology and have various causes, such as the infiltration of inflammatory cells and release of cytokines that can act as a barrier to neural regeneration. Another unique feature of SCI is the glial scar produced from the reactive proliferation of astrocytes, which acts as a barrier to axonal regeneration. Interdisciplinary research is investigating the use of biomaterials and tissue-engineered fabrication to overcome SCI. In this review, we discuss representative biomaterials, including natural and synthetic polymers and nanomaterials. In addition, we describe several strategies to repair spinal cord injuries, such as fabrication and the delivery of therapeutic biocomponents. These biomaterials and strategies may offer beneficial information to enhance the repair of spinal cord lesions.

Acidic fibroblast growth factor attenuates type 2 diabetes-induced demyelination via suppressing oxidative stress damage

Prolonged type 2 diabetes mellitus (T2DM) produces a common complication, peripheral neuropathy, which is accompanied by nerve fiber disorder, axon atrophy, and demyelination. Growing evidence has characterized the beneficial effects of acidic fibroblast growth factor (aFGF) and shown that it relieves hyperglycemia, increases insulin sensitivity, and ameliorates neuropathic impairment. However, there is scarce evidence on the role of aFGF on remodeling of aberrant myelin under hyperglycemia condition. Presently, we observed that the expression of aFGF was rapidly decreased in a db/db T2DM mouse model. Administration of exogenous aFGF was sufficient to block acute demyelination and nerve fiber disorganization. Furthermore, this strong anti-demyelinating effect was most likely dominated by an aFGF-mediated increase of Schwann cell (SC) proliferation and migration as well as suppression of its apoptosis. Mechanistically, the beneficial biological effects of aFGF on SC behavior and abnormal myelin morphology were likely due to the inhibition of hyperglycemia-induced oxidative stress activation, which was most likely activated by kelch-like ECH-associated protein 1 (Keap1)/nuclear factor erythroid-derived-like 2 (Nrf2) signaling. Thus, this evidence indicates that aFGF is a promising protective agent for relieving myelin pathology through countering oxidative stress signaling cascades under diabetic conditions.

How individuals with spinal cord injury in the United States access and assess information about experimental therapies and clinical trials: results of a clinical survey

STUDY DESIGN

An internet-based survey.

OBJECTIVES

To determine how individuals with spinal cord injury (SCI) access information about experimental therapies and clinical trials. To understand which factors influence receipt of and perceived trustworthiness of that information.

SETTING

Two academic medical centers and an SCI organization.

METHODS

Demographic information frequencies and percentages were calculated then analyzed using chi-square tests for independence. Fisher's exact test of independence was used to assess significance for contingency tables with categories containing expected counts below five.

RESULTS

Three hundred sixty four persons with SCI participated in the survey. Most felt confident in their ability to evaluate SCI-specific information from a variety of sources, though SCI organizations and the medical literature were deemed the most reliable. Information from SCI specialists was deemed more credible than that from non-SCI specialists, but only 53.6% of participants had access to them. Nearly all (89.0%) respondents who had sought information about experimental therapies had found it online, while 51.4% of those who had participated in a clinical trial had been contacted by a research team. Only 8.4% of participants felt their medical teams offered them sufficient information about experimental therapies and clinical trials. Wealthier and more educated respondents were more knowledgeable about health-related resources on the internet. Nearly all participants (96.9%) expressed interest in learning more about trials related to SCI.

CONCLUSIONS

There is an information deficit among people with SCI pertaining to experimental therapies and clinical trials. It is exacerbated by lack of income, education, and access to SCI specialists.

Resolvin D3 Promotes Inflammatory Resolution, Neuroprotection, and Functional Recovery After Spinal Cord Injury

Resolvins, a new family from the endogenous specialized pro-resolving mediators (SPMs), promote the resolution of the inflammatory response. Resolvin D3 (RvD3), a docosahexaenoic acid (DHA) product, has been known to suppress the inflammatory response. However, the anti-inflammatory and neuroprotective effects of RvD3 are not known in a model of spinal cord injury (SCI). Here, we investigated the anti-inflammatory and neuroprotective effect of RvD3 in a mouse model of SCI. Processes associated with anti-inflammation and angiogenesis were studied in RAW 264.7 cells and the human brain endothelial cell line hCMEC/D3, respectively. Additionally, female C57BL/6 mice were subjected to moderate compression SCI (20-g weight compression for 1 min) followed by intrathecal injection of vehicle or RvD3 (1 μg/20 μL) at 1 h post-SCI. RvD3 decreased the lipopolysaccharide (LPS)-induced production of inflammatory mediators and nitric oxide (NO) in RAW 264.7 cells and promoted an angiogenic effect in the hCMEC/D3 cell line. Treatment with RvD3 improved locomotor recovery and reduced thermal hyperalgesia in SCI mice compared with vehicle treatment at 14 days post-SCI. Remarkably, RvD3-treated mice exhibited reduced expression of inflammatory cytokines (TNF-α, IL6, IL1β) and chemokines (CCL2, CCL3). Also, RvD3-treated mice exhibited increased expression of tight junction proteins such as zonula occludens (ZO)-1 and occludin. Furthermore, immunohistochemistry showed a decreased level of gliosis (GFAP, Iba-1) and neuroinflammation (CD68, TGF-β) and enhanced neuroprotection. These data provide evidence that intrathecal injection of RvD3 represents a promising therapeutic strategy to promote inflammatory resolution, neuroprotection, and neurological functional recovery following SCI.

Thermosensitive heparin-poloxamer hydrogel encapsulated bFGF and NGF to treat spinal cord injury

The application of growth factors (GFs) for treating chronic spinal cord injury (SCI) has been shown to promote axonal regeneration and functional recovery. However, direct administration of GFs is limited by their rapid degradation and dilution at the injured sites. Moreover, SCI recovery is a multifactorial process that requires multiple GFs to participate in tissue regeneration. Based on these facts, controlled delivery of multiple growth factors (GFs) to lesion areas is becoming an attractive strategy for repairing SCI. Presently, we developed a GFs‐based delivery system (called GFs‐HP) that consisted of basic fibroblast growth factor (bFGF), nerve growth factor (NGF) and heparin‐poloxamer (HP) hydrogel through self‐assembly mode. This GFs‐HP was a kind of thermosensitive hydrogel that was suitable for orthotopic administration in vivo. Meanwhile, a 3D porous structure of this hydrogel is commonly used to load large amounts of GFs. After single injection of GFs‐HP into the lesioned spinal cord, the sustained release of NGF and bFGF from HP could significantly improve neuronal survival, axon regeneration, reactive astrogliosis suppression and locomotor recovery, when compared with the treatment of free GFs or HP. Moreover, we also revealed that these neuroprotective and neuroregenerative effects of GFs‐HP were likely through activating the phosphatidylinositol 3 kinase and protein kinase B (PI3K/Akt) and mitogen‐activated protein kinase/extracellular signal‐regulated kinase (MAPK/ERK) signalling pathways. Overall, our work will provide an effective therapeutic strategy for SCI repair.