Fibroblast growth factors in the management of spinal cord injury

Spinal Cord Injury Management Based on Microglia-Targeting Therapies

Spinal cord injury is a complicated medical condition both from the clinician's point of view in terms of management and from the patient's perspective in terms of unsatisfactory recovery. Depending on the severity, this disorder can be devastating despite the rapid and appropriate use of modern imaging techniques and convenient surgical spinal cord decompression and stabilization. In this context, there is a mandatory need for novel adjunctive therapeutic approaches to classical treatments to improve rehabilitation chances and clinical outcomes. This review offers a new and original perspective on therapies targeting the microglia, one of the most relevant immune cells implicated in spinal cord disorders. The first part of the manuscript reviews the anatomical and pathophysiological importance of the blood-spinal cord barrier components, including the role of microglia in post-acute neuroinflammation. Subsequently, the authors present the emerging therapies based on microglia modulation, such as cytokines modulators, stem cell, microRNA, and nanoparticle-based treatments that could positively impact spinal cord injury management. Finally, future perspectives and challenges are also highlighted based on the ongoing clinical trials related to medications targeting microglia.

The role of small extracellular vesicles and microRNA as their cargo in the spinal cord injury pathophysiology and therapy

Spinal cord injury (SCI) is a devastating condition with a complex pathology that affects a significant portion of the population and causes long-term consequences. After primary injury, an inflammatory cascade of secondary injury occurs, followed by neuronal cell death and glial scar formation. Together with the limited regenerative capacity of the central nervous system, these are the main reasons for the poor prognosis after SCI. Despite recent advances, there is still no effective treatment. Promising therapeutic approaches include stem cells transplantation, which has demonstrated neuroprotective and immunomodulatory effects in SCI. This positive effect is thought to be mediated by small extracellular vesicles (sEVs); membrane-bound nanovesicles involved in intercellular communication through transport of functional proteins and RNA molecules. In this review, we summarize the current knowledge about sEVs and microRNA as their cargo as one of the most promising therapeutic approaches for the treatment of SCI. We provide a comprehensive overview of their role in SCI pathophysiology, neuroprotective potential and therapeutic effect.

Neurophysiological, histological, and behavioral characterization of animal models of distraction spinal cord injury: a systematic review

Distraction spinal cord injury is caused by some degree of distraction or longitudinal tension on the spinal cord and commonly occurs in patients who undergo corrective operation for severe spinal deformity. With the increased degree and duration of distraction, spinal cord injuries become more serious in terms of their neurophysiology, histology, and behavior. Very few studies have been published on the specific characteristics of distraction spinal cord injury. In this study, we systematically review 22 related studies involving animal models of distraction spinal cord injury, focusing particularly on the neurophysiological, histological, and behavioral characteristics of this disease. In addition, we summarize the mechanisms underlying primary and secondary injuries caused by distraction spinal cord injury and clarify the effects of different degrees and durations of distraction on the primary injuries associated with spinal cord injury. We provide new concepts for the establishment of a model of distraction spinal cord injury and related basic research, and provide reference guidelines for the clinical diagnosis and treatment of this disease.

Function of GSK‑3 signaling in spinal cord injury (Review)

Spinal cord injury (SCI) is a major social problem with a heavy burden on patient physiology and psychology. Glial scar formation and irreversible neuron loss are the two key points during SCI progression. During the acute phase of spinal cord injury, glial scars form, limiting the progression of inflammation. However, in the subacute or chronic phase, glial scarring inhibits axon regeneration. Following spinal cord injury, irreversible loss of neurons leads to further aggravation of spinal cord injury. Several therapies have been developed to improve either glial scar or neuron loss; however, few therapies reach the stage of clinical trials and there are no mainstream therapies for SCI. Exploring the key mechanism of SCI is crucial for finding further treatments. Glycogen synthase kinase-3 (GSK-3) is a widely expressed kinase with important physiological and pathophysiological functions in vivo. Dysfunction of the GSK-3 signaling pathway during SCI has been widely discussed for controlling neurite growth in vitro and in vivo, improving the proliferation and neuronal differentiation of endogenous neural stem cells and functional recovery from spinal cord injury. SCI can decrease the phosphorylated (p)/total (t)-GSK-3β ratio, which leads to an increase in apoptosis, whereas treatment with GSK-3 inhibitors can promote neurogenesis. In addition, several therapies for the treatment of SCI involve signaling pathways associated with GSK-3. Furthermore, signaling pathways associated with GSK-3 also participate in the pathological process of neuropathic pain that remains following SCI. The present review summarized the roles of GSK-3 signaling in SCI to aid in the understanding of GSK-3 signaling during the pathological processes of SCI and to provide evidence for the development of comprehensive treatments.

Blood-spinal cord barrier disruption in degenerative cervical myelopathy

Degenerative cervical myelopathy (DCM) is the most prevalent cause of spinal cord dysfunction in the aging population. Significant neurological deficits may result from a delayed diagnosis as well as inadequate neurological recovery following surgical decompression. Here, we review the pathophysiology of DCM with an emphasis on how blood-spinal cord barrier (BSCB) disruption is a critical yet neglected pathological feature affecting prognosis. In patients suffering from DCM, compromise of the BSCB is evidenced by elevated cerebrospinal fluid (CSF) to serum protein ratios and abnormal contrast-enhancement upon magnetic resonance imaging (MRI). In animal model correlates, there is histological evidence of increased extravasation of tissue dyes and serum contents, and pathological changes to the neurovascular unit. BSCB dysfunction is the likely culprit for ischemia-reperfusion injury following surgical decompression, which can result in devastating neurological sequelae. As there are currently no therapeutic approaches specifically targeting BSCB reconstitution, we conclude the review by discussing potential interventions harnessed for this purpose.

Suppression of Fibroblast Growth Factor Receptor-5 (FGFR5) has no Impact on Axon Regeneration after SCI

One of the most common forms of the mammalian central nervous system (CNS) injuries is spinal cord injury (SCI), and any lesion to the CNS can result in a lifelong functional impairment since CNS axons cannot regenerate. The relative axon regenerating genes following spinal SCI were examined using the regenerative SN, pSN + DC, and non-regenerating DC lesion models. By using qRT-PCR, we discovered that fibroblast growth factor receptor-5 (FGFR5) was 4.2-fold more highly expressed in non-regeneration lesions compared to intact control and regenerating animals. Furthermore, in cultured dorsal root ganglion neurons (DRGN), short interfering RNA (siRNA)-mediated knockdown of FGFR5 had no effect on DRGN neurite outgrowth, indicating that the gene's suppression has no effect on axon regeneration and may play other roles in the CNS besides axon regeneration.

Enzyme-Mediated Nerve Growth Factor Release from Nanofibers Using Gelatin Microspheres

Spinal cord injury is a complex environment, with many conflicting growth factors present at different times throughout the injury timeline. Delivery of multiple growth factors has received mixed results, highlighting a need to consider the timing of delivery for possibly antagonistic growth factors. Cell-mediated degradation of delivery vehicles for delayed release of growth factors offers an attractive way to exploit the highly active immune response in the spinal cord injury environment. In this study, growth factor-loaded gelatin microspheres (GMS) combined with methacrylated hyaluronic acid (MeHA) were electrospun to create GMS fibers (GMSF) for delayed release of growth factors (GFs). GMS were successfully combined with MeHA while electrospinning, with an average fiber diameter of 365 ± 10 nm and 44% ± 8% fiber alignment. GMSF with nerve growth factor (NGF) was tested on dissociated chick dorsal root ganglia cells. We further tested the effect of M1 macrophage-conditioned media (M1CM) to simulate macrophage invasion after spinal cord injury for cell-mediated degradation. We hypothesized that neurons grown on GMSF with loaded NGF would exhibit longer neurites in M1CM, showing a release of functional NGF, as compared with controls. GMSF in M1CM was significantly different from MeHA in serum-free media (SFM) and M0-conditioned media (M0CM), as well as GMSF in M0CM (p < 0.05). Moreover, GMSF + NGF in all media conditions were significantly different from MeHA in SFM and M0CM (p < 0.05). The goal of this study was to develop a biomaterial system where drug delivery is triggered by immune response, allowing for more control and longer exposure to encapsulated drugs. The spinal cord injury microenvironment is known to have a robust immune response, making this immune-medicated drug release system particularly significant for directed repair.

Immune response following traumatic spinal cord injury: Pathophysiology and therapies

Traumatic spinal cord injury (SCI) is a devastating condition that is often associated with significant loss of function and/or permanent disability. The pathophysiology of SCI is complex and occurs in two phases. First, the mechanical damage from the trauma causes immediate acute cell dysfunction and cell death. Then, secondary mechanisms of injury further propagate the cell dysfunction and cell death over the course of days, weeks, or even months. Among the secondary injury mechanisms, inflammation has been shown to be a key determinant of the secondary injury severity and significantly worsens cell death and functional outcomes. Thus, in addition to surgical management of SCI, selectively targeting the immune response following SCI could substantially decrease the progression of secondary injury and improve patient outcomes. In order to develop such therapies, a detailed molecular understanding of the timing of the immune response following SCI is necessary. Recently, several studies have mapped the cytokine/chemokine and cell proliferation patterns following SCI. In this review, we examine the immune response underlying the pathophysiology of SCI and assess both current and future therapies including pharmaceutical therapies, stem cell therapy, and the exciting potential of extracellular vesicle therapy.

Dual Role of Fibroblast Growth Factor Pathways in Sleep Regulation

Sleep plays an important function in neuro-immuno-endocrine homeostasis. Sleep disorders have been associated with an increased risk of metabolic and cognitive impairments. Among different factors that have an effect on sleep metabolism, a growing body of literature has investigated growth factors in the course of sleep quality and disorders. A good example of growth factors is fibroblast growth factors (FGFs), which are a large family of polypeptide growth factors. Evidence has shown that FGFs are involved in the modulation of sleep-wake behavior by their receptor subtypes and ligands, e.g., FFG1 plays an important role in the quality of sleep through somnogenic effects, while the high level of FGF23 is associated with secondary disorders in shift workers. Therefore, a controversial effect of FGFs can be seen in the course of sleep in physiologic and pathologic conditions. Further investigation on this topic would help us to understand the role of FGFs in sleep disorders as a therapeutic option and biomarker.

Molecular approaches for spinal cord injury treatment

Injuries to the spinal cord result in permanent disabilities that limit daily life activities. The main reasons for these poor outcomes are the limited regenerative capacity of central neurons and the inhibitory milieu that is established upon traumatic injuries. Despite decades of research, there is still no efficient treatment for spinal cord injury. Many strategies are tested in preclinical studies that focus on ameliorating the functional outcomes after spinal cord injury. Among these, molecular compounds are currently being used for neurological recovery, with promising results. These molecules target the axon collapsed growth cone, the inhibitory microenvironment, the survival of neurons and glial cells, and the re-establishment of lost connections. In this review we focused on molecules that are being used, either in preclinical or clinical studies, to treat spinal cord injuries, such as drugs, growth and neurotrophic factors, enzymes, and purines. The mechanisms of action of these molecules are discussed, considering traumatic spinal cord injury in rodents and humans.

Metformin Attenuates Ferroptosis and Promotes Functional Recovery of Spinal Cord Injury

BACKGROUND

Ferroptosis is involved in traumatic spinal cord injury (SCI), and its inhibition may improve functional recovery after traumatic SCI. This study investigated whether metformin (Met) can have a neuroprotective effect in SCI repair by inhibiting ferroptosis.

METHODS

We assessed functional change to determine the long-term effects after intraperitoneal injection of Met in SCI rats with the Basso-Beattie-Bresnahan locomotor rating scale. Malondialdehyde level and relative expression of key proteins, inflammatory cytokines, and nuclear factor E2-related factor 2 signalling molecules were determined in SCI rats and PC12 cells exposed to FeCl₃ solution.

RESULTS

Met treatment decreased the contents of malondialdehyde, regulated the levels of inflammatory factors, activated the nuclear factor E2-related factor 2 signalling pathway, and improved long-term outcomes by ameliorating SCI-induced locomotor deficits. In vitro studies further confirmed the beneficial and antiferroptotic actions of Met partly through activation of nuclear factor E2-related factor 2 signalling.

CONCLUSION

Met can have a neuroprotective effect on SCI repair partly through antiferroptotic effects.

Biomaterial-Mediated Factor Delivery for Spinal Cord Injury Treatment

Spinal cord injury (SCI) is an injurious process that begins with immediate physical damage to the spinal cord and associated tissues during an acute traumatic event. However, the tissue damage expands in both intensity and volume in the subsequent subacute phase. At this stage, numerous events exacerbate the pathological condition, and therein lies the main cause of post-traumatic neural degeneration, which then ends with the chronic phase. In recent years, therapeutic interventions addressing different neurodegenerative mechanisms have been proposed, but have met with limited success when translated into clinical settings. The underlying reasons for this are that the pathogenesis of SCI is a continued multifactorial disease, and the treatment of only one factor is not sufficient to curb neural degeneration and resulting paralysis. Recent advances have led to the development of biomaterials aiming to promote in situ combinatorial strategies using drugs/biomolecules to achieve a maximized multitarget approach. This review provides an overview of single and combinatorial regenerative-factor-based treatments as well as potential delivery options to treat SCIs.

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.

Novel Thermosensitive Hydrogel Promotes Spinal Cord Repair by Regulating Mitochondrial Function

The repair of spinal cord injury (SCI) is still a tough clinical challenge and needs innovative therapies. Mitochondrial function is significantly compromised after SCI and has emerged as an important factor causing neuronal apoptosis and hindering functional recovery. In this study, umbilical cord mesenchymal stem cells (UCMSC), which are promising seed cells for nerve regeneration, and basic fibroblast growth factor (bFGF) that have been demonstrated to have a variety of effects on neural regeneration were jointly immobilized in extracellular matrix (ECM) and heparin-poloxamer (HP) to create a polymer bioactive system that brings more hope and possibility for the treatment of SCI. Our results in vitro and in vivo showed that the UCMSC-bFGF-ECM-HP thermosensitive hydrogel has good therapeutic effects, mainly in reducing apoptosis and improving the mitochondrial function. It showed promising utility for the functional recovery of impaired mitochondrial function by promoting mitochondrial fusion, reducing pathological mitochondrial fragmentation, increasing mitochondrial energy supply, and improving the metabolism of MDA, LDH, and ROS. In addition, we uncovered a distinct molecular mechanism underlying the protective effects associated with activating p21-activated kinase 1 (PAK1) and mitochondrial sirtuin 4 (SIRT4) by the UCMSC-bFGF-ECM-HP hydrogel. The expansion of new insights into the molecular relationships between PAK1 and SIRT4, which links the mitochondrial function in SCI, can lay the foundation for future applications and help to provide promising interventions of stem-cell-based biological scaffold therapies and potential therapeutic targets for the clinical formulation of SCI treatment strategies.

Progression in translational research on spinal cord injury based on microenvironment imbalance

Spinal cord injury (SCI) leads to loss of motor and sensory function below the injury level and imposes a considerable burden on patients, families, and society. Repair of the injured spinal cord has been recognized as a global medical challenge for many years. Significant progress has been made in research on the pathological mechanism of spinal cord injury. In particular, with the development of gene regulation, cell sequencing, and cell tracing technologies, in-depth explorations of the SCI microenvironment have become more feasible. However, translational studies related to repair of the injured spinal cord have not yielded significant results. This review summarizes the latest research progress on two aspects of SCI pathology: intraneuronal microenvironment imbalance and regenerative microenvironment imbalance. We also review repair strategies for the injured spinal cord based on microenvironment imbalance, including medications, cell transplantation, exosomes, tissue engineering, cell reprogramming, and rehabilitation. The current state of translational research on SCI and future directions are also discussed. The development of a combined, precise, and multitemporal strategy for repairing the injured spinal cord is a potential future direction.

Advanced approaches to regenerate spinal cord injury: The development of cell and tissue engineering therapy and combinational treatments

Spinal cord injury (SCI) is a central nervous system (CNS) devastate event that is commonly caused by traumatic or non-traumatic events. The reinnervation of spinal cord axons is hampered through a myriad of devices counting on the damaged myelin, inflammation, glial scar, and defective inhibitory molecules. Unfortunately, an effective treatment to completely repair SCI and improve functional recovery has not been found. In this regard, strategies such as using cells, biomaterials, biomolecules, and drugs have been reported to be effective for SCI recovery. Furthermore, recent advances in combinatorial treatments, which address various aspects of SCI pathophysiology, provide optimistic outcomes for spinal cord regeneration. According to the global importance of SCI, the goal of this article review is to provide an overview of the pathophysiology of SCI, with an emphasis on the latest modes of intervention and current advanced approaches for the treatment of SCI, in conjunction with an assessment of combinatorial approaches in preclinical and clinical trials. So, this article can give scientists and clinicians' clues to help them better understand how to construct preclinical and clinical studies that could lead to a breakthrough in spinal cord regeneration.

Application and progress of three-dimensional bioprinting in spinal cord injury

Spinal cord injury (SCI) is a central nervous system disorder that can lead to sensory and motor dysfunction, which can seriously increase pressure and economic burden on families and societies. The current SCI treatment is mainly to stabilize the spine, prevent secondary damage, and control inflammation. Drug treatment is limited to early, large-scale use of steroids to reduce the effects of edema after SCI. In short, there is no direct treatment for SCI. Recent 3D bioprinting development provides a new solution for SCI treatment: a series of spinal cord bionic scaffolds are being developed to improve spinal cord function after injury. This paper reviews the pathophysiological characteristics of SCI, current treatment methods, and the progress of 3D bioprinting in SCI. Finally, its challenges and prospects in SCI treatment are summarized.

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.

Disease-specific glycosaminoglycan patterns in the extracellular matrix of human lung and brain

A wide variety of diseases throughout the mammalian organism is characterized by abnormal deposition of various components of the extracellular matrix (ECM), including the heterogeneous family of glycosaminoglycans (GAGs), which contribute considerably to the ECM architecture as part of the so-called proteoglycans. The GAG's unique sulfation pattern, derived from highly dynamic and specific modification processes, has a massive impact on critical mediators such as cytokines and growth factors. Due to the strong connection between the specific sulfation pattern and GAG function, slight alterations of this pattern are often associated with enormous changes at the cell as well as at the organ level. This review aims to investigate the connection between modifications of GAG sulfation patterns and the wide range of pathological conditions, mainly focusing on a range of chronic diseases of the central nervous system (CNS) as well as the respiratory tract.

GDF-11 Protects the Traumatically Injured Spinal Cord by Suppressing Pyroptosis and Necroptosis via TFE3-Mediated Autophagy Augmentation

Spinal cord injury (SCI) refers to a major worldwide cause of accidental death and disability. However, the complexity of the pathophysiological mechanism can result in less-effective clinical treatment. Growth differentiation factor 11 (GDF-11), an antiageing factor, was reported to affect the development of neurogenesis and exert a neuroprotective effect after cerebral ischaemic injury. The present work is aimed at investigating the influence of GDF-11 on functional recovery following SCI, in addition to the potential mechanisms involved. We employed a mouse model of spinal cord contusion injury and assessed functional outcomes via the Basso Mouse Scale and footprint analysis following SCI. Using western blot assays and immunofluorescence, we analysed the levels of pyroptosis, autophagy, necroptosis, and molecules related to the AMPK-TRPML1-calcineurin signalling pathway. The results showed that GDF-11 noticeably optimized function-related recovery, increased autophagy, inhibited pyroptosis, and alleviated necroptosis following SCI. Furthermore, the conducive influences exerted by GDF-11 were reversed with the application of 3-methyladenine (3MA), an autophagy suppressor, indicating that autophagy critically impacted the therapeutically related benefits of GDF-11 on recovery after SCI. In the mechanistic study described herein, GDF-11 stimulated autophagy improvement and subsequently inhibited pyroptosis and necroptosis, which were suggested to be mediated by TFE3; this effect resulted from the activity of TFE3 through the AMPK-TRPML1-calcineurin signalling cascade. Together, GDF-11 protects the injured spinal cord by suppressing pyroptosis and necroptosis via TFE3-mediated autophagy augmentation and is a potential agent for SCI therapy.

Engineered basic fibroblast growth factor-overexpressing human umbilical cord-derived mesenchymal stem cells improve the proliferation and neuronal differentiation of endogenous neural stem cells and functional recovery of spinal cord injury by activating the PI3K-Akt-GSK-3β signaling pathway

Objectives

To investigate the safety for clinic use and therapeutic effects of basic fibroblast growth factor (bFGF)-overexpressing human umbilical cord-derived mesenchymal stem cells (HUCMSCs) in mice with completely transected spinal cord injury (SCI).

Methods

Stable bFGF-overexpressing HUCMSCs clones were established by electrotransfection and then subjected to systematic safety evaluations. Then, bFGF-overexpressing and control HUCMSCs were used to treat mice with completely transected SCI by tail intravenous injection. Therapeutic outcomes were then investigated, including functional recovery of locomotion, histological structures, nerve regeneration, and recovery mechanisms.

Results

Stable bFGF-overexpressing HUCMSCs met the standards and safety of MSCs for clinic use. In the mouse SCI model, stable bFGF-overexpressing HUCMSCs markedly improved therapeutic outcomes such as reducing glial scar formation, improving nerve regeneration and proliferation of endogenous neural stem cells (NSCs), and increasing locomotion functional recovery of posterior limbs compared with the control HUCMSCs group. Furthermore, bFGF-overexpressing HUCMSCs promoted the proliferation and neuronal differentiation of NSCs in vitro through the PI3K-Akt-GSK-3β pathway.

Conclusion

bFGF-overexpressing HUCMSCs meet the requirements of clinical MSCs and improve evident therapeutic outcomes of mouse SCI treatment, which firmly supports the safety and efficacy of gene-modified MSCs for clinical application.

Corticospinal Motor Circuit Plasticity After Spinal Cord Injury: Harnessing Neuroplasticity to Improve Functional Outcomes

Spinal cord injury (SCI) is a devastating condition that affects approximately 294,000 people in the USA and several millions worldwide. The corticospinal motor circuitry plays a major role in controlling skilled movements and in planning and coordinating movements in mammals and can be damaged by SCI. While axonal regeneration of injured fibers over long distances is scarce in the adult CNS, substantial spontaneous neural reorganization and plasticity in the spared corticospinal motor circuitry has been shown in experimental SCI models, associated with functional recovery. Beneficially harnessing this neuroplasticity of the corticospinal motor circuitry represents a highly promising therapeutic approach for improving locomotor outcomes after SCI. Several different strategies have been used to date for this purpose including neuromodulation (spinal cord/brain stimulation strategies and brain-machine interfaces), rehabilitative training (targeting activity-dependent plasticity), stem cells and biological scaffolds, neuroregenerative/neuroprotective pharmacotherapies, and light-based therapies like photodynamic therapy (PDT) and photobiomodulation (PMBT). This review provides an overview of the spontaneous reorganization and neuroplasticity in the corticospinal motor circuitry after SCI and summarizes the various therapeutic approaches used to beneficially harness this neuroplasticity for functional recovery after SCI in preclinical animal model and clinical human patients' studies.

The Regenerative Potential of bFGF in Dental Pulp Repair and Regeneration

Regenerative endodontic therapy intends to induce the host’s natural wound-healing process, which can restore the vitality, immunity, and sensitivity of the inflammatory or necrotic pulp tissue destroyed by infection or trauma. Myriads of growth factors are critical in the processes of pulp repair and regeneration. Among the key regulatory factors are the fibroblast growth factors, which have turned out to be the master regulators of both organogenesis and tissue homeostasis. Fibroblast growth factors, a family composed of 22 polypeptides, have been used in tissue repair and regeneration settings, in conditions as diverse as burns, ulcers, bone-related diseases, and spinal cord injuries. Meanwhile, in dentistry, the basic fibroblast growth factor is the most frequently investigated. Thereby, the aim of this review is 2-fold: 1) foremost, to explore the underlying mechanisms of the bFGF in dental pulp repair and regeneration and 2) in addition, to shed light on the potential therapeutic strategies of the bFGF in dental pulp–related clinical applications.

Multimodal treatment combining cold atmospheric plasma and acidic fibroblast growth factor for multi-tissue regeneration

Cold atmospheric plasma (CAP) is an emerging technology for biomedical applications, exemplified by its antimicrobial and antineoplastic potentials. On the contrary, acidic fibroblast growth factor (aFGF) has been a long-standing potent mitogen for cells from various origins. In this study, we are the first to develop a multimodal treatment combining the aforementioned physicochemical and pharmacological treatments and investigated their individual and combined effects on wound healing, angiogenesis, neurogenesis, and osteogenesis. This work was performed at the tissue, cellular, protein, and gene levels, using histochemical staining, flow cytometry, ELISA, and PCR, respectively. Depending on the type of target tissue, various combinations of aforementioned methods were used. The results showed that the enhancement on would healing and angiogenesis by CAP and aFGF were synergistic. The former was manifested by increased murine fibroblast proliferation and reduced cutaneous tissue inflammation, whereas the latter by upregulated proangiogenic markers in vivo, for example, CD31, VEGF, and TGF-β, and downregulated antiangiogenic proteins in vitro, for example, angiostatin and angiopoietin-2, respectively. In addition, aFGF outperformed CAP during neurogenesis, which was evidenced by superior neurite outgrowth, while CAP exceeded aFGF in osteogenesis which was demonstrated by more substantial bone nodule formation. These novel findings not only support the fact that CAP and aFGF are both multipotent agents during tissue regeneration, but also highlight the potential of our multimodal treatment combining the individual advantages of CAP and aFGF. The versatile administration route, that is, topical and/or systemic, might further broaden its applications.

Fibroblast Growth Factors as Tools in the Management of Neuropathic Pain Disorders

Neuropathic pain is caused by a damage to or dysfunction of the somatosensory nervous system. The main mechanisms underlying neuropathic pain include ectopic activity in nociceptive nerves, peripheral and central sensitization, impaired inhibitory modulation, and microglial activation. Fibroblast growth factors (FGFs) make up a large family of growth factors that mediate neural development, metabolism, and function through three main key signaling pathways, including RAS/MAP kinase pathway, PI3 kinase/Akt pathway, and PLCγ. An association between the members of the FGF system and the improvement of neuropathic pain has become evident, recently. These signaling molecules may be expected to provide new drug targets for the treatment of neuropathic pain. To the best of our knowledge, it is the first study that reviews the relationship between some members of the FGF system and neuropathic pain.

Acute spinal cord injury: Pathophysiology and pharmacological intervention (Review)

Spinal cord injury (SCI) is one of the most debilitating of all the traumatic conditions that afflict individuals. For a number of years, extensive studies have been conducted to clarify the molecular mechanisms of SCI. Experimental and clinical studies have indicated that two phases, primary damage and secondary damage, are involved in SCI. The initial mechanical damage is caused by local impairment of the spinal cord. In addition, the fundamental mechanisms are associated with hyperflexion, hyperextension, axial loading and rotation. By contrast, secondary injury mechanisms are led by systemic and cellular factors, which may also be initiated by the primary injury. Although significant advances in supportive care have improved clinical outcomes in recent years, a number of studies continue to explore specific pharmacological therapies to minimize SCI. The present review summarized some important pathophysiologic mechanisms that are involved in SCI and focused on several pharmacological and non‑pharmacological therapies, which have either been previously investigated or have a potential in the management of this debilitating injury in the near future.

Planet of the AAVs: The Spinal Cord Injury Episode

The spinal cord injury (SCI) is a medical and life-disrupting condition with devastating consequences for the physical, social, and professional welfare of patients, and there is no adequate treatment for it. At the same time, gene therapy has been studied as a promising approach for the treatment of neurological and neurodegenerative disorders by delivering remedial genes to the central nervous system (CNS), of which the spinal cord is a part. For gene therapy, multiple vectors have been introduced, including integrating lentiviral vectors and non-integrating adeno-associated virus (AAV) vectors. AAV vectors are a promising system for transgene delivery into the CNS due to their safety profile as well as long-term gene expression. Gene therapy mediated by AAV vectors shows potential for treating SCI by delivering certain genetic information to specific cell types. This review has focused on a potential treatment of SCI by gene therapy using AAV vectors.

Mechanisms driving the initiation and direction of endothelial sprouting in organotypic co-culture of aorta and spinal cord tissues

The resumption of blood supply in spinal cord (SC) after injury is a prerequisite of its recovery. To expose the mechanisms of damaged SC revascularization we have used an organotypic SC/aortic fragments (AF) co-culture where, as we showed previously, damaged SC tissue induces AF cell sprouting but repels them away. Supplementation of culture medium with exogenous VEGF-A₁₆₅ redirects the migrating aortic endothelial cells towards SC tissue. This effect and the pattern of sFlt1 expression (a soluble form of VEGFR1) suggest that the low level of SC-secreted VEGF and the presence of sFlt1 in SC slices together prevent the migration of aortic CD31⁺ cells to the SC in the absence of exogenous VEGF. VEGF-A₁₆₅ supplementation sequesters this inhibitory activity of sFlt1 by direct binding thus allowing CD31⁺ cell migration in to SC tissue. Proteome analysis has shown that migration/proliferation of CD31⁺ and αSMA⁺ aortic cells in neuronal culture medium used in our SC/AF model (which obstruct sprouting by itself) was resumed by combined action of several pro- (aFGF, bFGF, Osteopontin, TF, IGFBP2, SDF1) and anti-angiogenic (Endostatin/Collagen18) factors. The mutual influence of AF and SC tissues is a key factor balancing these factors and thus driving endothelial sprouting in SC injury zone.

Pharmacological management of secondary spinal cord injury

Introduction: Secondary spinal cord injury (SCI) sets on immediately after trauma and, despite prompt treatment, may become chronic. SCI is a complex condition and presents numerous challenges to patients and physicians alike, also considering the lack of an approved pharmacological therapy.Areas covered: This review describes the pathophysiological mechanisms leading to secondary SCI to highlight possible targets for pharmacological therapy. Furthermore, an extensive search of the literature on different databases (PubMed, Google scholar, Embase, and Scopus) and of the current clinical trials (clinicaltrials.gov) was performed to investigate the current outlook for the pharmacological management of SCI. Only drugs with performed or ongoing clinical trials were considered.Expert opinion: Pharmacological therapy aims to improve motor and sensory function in patients. Overall, drugs are divided into neuroprotective compounds, which aim to limit the damage induced by the pro-inflammatory and pro-apoptotic milieu of SCI, and neuroregenerative drugs, which induce neuronal and axonal regrowth. While many compounds have been trialed with promising results, none has yet completed a stage III trial and has been approved for the pharmacological management of SCI.

Mechanisms and repair strategies for white matter degeneration in CNS injury and diseases

White matter degeneration is an important pathophysiological event of the central nervous system that is collectively characterized by demyelination, oligodendrocyte loss, axonal degeneration and parenchymal changes that can result in sensory, motor, autonomic and cognitive impairments. White matter degeneration can occur due to a variety of causes including trauma, neurotoxic exposure, insufficient blood flow, neuroinflammation, and developmental and inherited neuropathies. Regardless of the etiology, the degeneration processes share similar pathologic features. In recent years, a plethora of cellular and molecular mechanisms have been identified for axon and oligodendrocyte degeneration including oxidative damage, calcium overload, neuroinflammatory events, activation of proteases, depletion of adenosine triphosphate and energy supply. Extensive efforts have been also made to develop neuroprotective and neuroregenerative approaches for white matter repair. However, less progress has been achieved in this area mainly due to the complexity and multifactorial nature of the degeneration processes. Here, we will provide a timely review on the current understanding of the cellular and molecular mechanisms of white matter degeneration and will also discuss recent pharmacological and cellular therapeutic approaches for white matter protection as well as axonal regeneration, oligodendrogenesis and remyelination.

Programmed cell death in spinal cord injury pathogenesis and therapy

Spinal cord injury (SCI) always leads to functional deterioration due to a series of processes including cell death. In recent years, programmed cell death (PCD) is considered to be a critical process after SCI, and various forms of PCD were discovered in recent years, including apoptosis, necroptosis, autophagy, ferroptosis, pyroptosis and paraptosis. Unlike necrosis, PCD is known as an active cell death mediated by a cascade of gene expression events, and it is crucial for elimination unnecessary and damaged cells, as well as a defence mechanism. Therefore, it would be meaningful to characterize the roles of PCD to not only enhance our understanding of the pathophysiological processes, but also improve functional recovery after SCI. This review will summarize and explore the most recent advances on how apoptosis, necroptosis, autophagy, ferroptosis, pyroptosis and paraptosis are involved in SCI. This review can help us to understand the various functions of PCD in the pathological processes of SCI, and contribute to our novel understanding of SCI of unknown aetiology in the near future.

Programmed cell death in spinal cord injury pathogenesis and therapy

Spinal cord injury (SCI) always leads to functional deterioration due to a series of processes including cell death. In recent years, programmed cell death (PCD) is considered to be a critical process after SCI, and various forms of PCD were discovered in recent years, including apoptosis, necroptosis, autophagy, ferroptosis, pyroptosis and paraptosis. Unlike necrosis, PCD is known as an active cell death mediated by a cascade of gene expression events, and it is crucial for elimination unnecessary and damaged cells, as well as a defence mechanism. Therefore, it would be meaningful to characterize the roles of PCD to not only enhance our understanding of the pathophysiological processes, but also improve functional recovery after SCI. This review will summarize and explore the most recent advances on how apoptosis, necroptosis, autophagy, ferroptosis, pyroptosis and paraptosis are involved in SCI. This review can help us to understand the various functions of PCD in the pathological processes of SCI, and contribute to our novel understanding of SCI of unknown aetiology in the near future.

Spinal Reflex Recovery after Dorsal Rhizotomy and Repair with Platelet-Rich Plasma (PRP) Gel Combined with Bioengineered Human Embryonic Stem Cells (hESCs)

Dorsal root rhizotomy (DRZ) is currently considered an untreatable injury, resulting in the loss of sensitive function and usually leading to neuropathic pain. In this context, we recently proposed a new surgical approach to treat DRZ that uses platelet-rich plasma (PRP) gel to restore the spinal reflex. Success was correlated with the reentry of primary afferents into the spinal cord. Here, aiming to enhance previous results, cell therapy with bioengineered human embryonic stem cells (hESCs) to overexpress fibroblast growth factor 2 (FGF2) was combined with PRP. For these experiments, adult female rats were submitted to a unilateral rhizotomy of the lumbar spinal dorsal roots, which was followed by root repair with PRP gel with or without bioengineered hESCs. One week after DRZ, the spinal cords were processed to evaluate changes in the glial response (GFAP and Iba-1) and excitatory synaptic circuits (VGLUT1) by immunofluorescence. Eight weeks postsurgery, the lumbar intumescences were processed for analysis of the repaired microenvironment by transmission electron microscopy. Spinal reflex recovery was evaluated by the electronic Von Frey method for eight weeks. The transcript levels for human FGF2 were over 37-fold higher in the induced hESCs than in the noninduced and the wildtype counterparts. Altogether, the results indicate that the combination of hESCs with PRP gel promoted substantial and prominent axonal regeneration processes after DRZ. Thus, the repair of dorsal roots, if done appropriately, may be considered an approach to regain sensory-motor function after dorsal root axotomy.

Intrathecal Injection of SIRT1-modified Human Mesenchymal Stem Cells Alleviates Neuropathic Pain in Rat

Accumulating evidence has elucidated that human mesenchymal stem cells (hMSCs) exert profound analgesic effects on numerous animal models of neuropathic pain, including drug-induced peripheral nerves, diabetes-induced neuropathy, and chronic constriction injury. We aimed to address whether forcing expression of sirtuin 1 (SIRT1) can enhance the efficacy of hMSCs on alleviation of pain sensation. A rat model of chronic constriction injury (CCI) mimicking peripheral nerve injury was incorporated in the study. Paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) testing were used to measure pain-related behavior. Our results demonstrated that SIRT1 was decreased post-CCI surgery. Compared to hMSCs-control implantation, the hMSCs-SIRT1 (hMSCs overexpressing SIRT1) implantation exhibited superior effects on reducing pro-inflammatory cytokine levels in serum and spinal dorsal horn, while ameliorating neuropathic pain in CCI rat. Engineering hMSCs such as overexpressing SIRT1 may serve as a promising strategy for the treatment of patients with neuropathic pain.

Growth factors-based therapeutic strategies and their underlying signaling mechanisms for peripheral nerve regeneration

Peripheral nerve injury (PNI), one of the most common concerns following trauma, can result in a significant loss of sensory or motor function. Restoration of the injured nerves requires a complex cellular and molecular response to rebuild the functional axons so that they can accurately connect with their original targets. However, there is no optimized therapy for complete recovery after PNI. Supplementation with exogenous growth factors (GFs) is an emerging and versatile therapeutic strategy for promoting nerve regeneration and functional recovery. GFs activate the downstream targets of various signaling cascades through binding with their corresponding receptors to exert their multiple effects on neurorestoration and tissue regeneration. However, the simple administration of GFs is insufficient for reconstructing PNI due to their short half‑life and rapid deactivation in body fluids. To overcome these shortcomings, several nerve conduits derived from biological tissue or synthetic materials have been developed. Their good biocompatibility and biofunctionality made them a suitable vehicle for the delivery of multiple GFs to support peripheral nerve regeneration. After repairing nerve defects, the controlled release of GFs from the conduit structures is able to continuously improve axonal regeneration and functional outcome. Thus, therapies with growth factor (GF) delivery systems have received increasing attention in recent years. Here, we mainly review the therapeutic capacity of GFs and their incorporation into nerve guides for repairing PNI. In addition, the possible receptors and signaling mechanisms of the GF family exerting their biological effects are also emphasized.

Current strategies for therapeutic drug delivery after traumatic CNS injury

Therapeutic strategies for traumatic injuries in the central nervous system (CNS) are largely limited to the efficiency of drug delivery. Despite the disrupted blood-CNS barrier during the early phase after injury, the drug administration faces a variety of obstacles derived from homeostatic imbalance at the injury site. In the late phase after CNS injury, the restoration of the blood-CNS barrier integrity varies depending on the injury severity resulting in inconsistent delivery of therapeutics. This review intends to characterize those different challenges of the therapeutic delivery in acute and chronic phases after injury and discuss recent advances in various approaches to explore novel strategies for the treatment of traumatic CNS injury.

Strategies and prospects of effective neural circuits reconstruction after spinal cord injury

Due to the disconnection of surviving neural elements after spinal cord injury (SCI), such patients had to suffer irreversible loss of motor or sensory function, and thereafter enormous economic and emotional burdens were brought to society and family. Despite many strategies being dealing with SCI, there is still no effective regenerative therapy. To date, significant progress has been made in studies of SCI repair strategies, including gene regulation of neural regeneration, cell or cell-derived exosomes and growth factors transplantation, repair of biomaterials, and neural signal stimulation. The pathophysiology of SCI is complex and multifaceted, and its mechanisms and processes are incompletely understood. Thus, combinatorial therapies have been demonstrated to be more effective, and lead to better neural circuits reconstruction and functional recovery. Combinations of biomaterials, stem cells, growth factors, drugs, and exosomes have been widely developed. However, simply achieving axon regeneration will not spontaneously lead to meaningful functional recovery. Therefore, the formation and remodeling of functional neural circuits also depend on rehabilitation exercises, such as exercise training, electrical stimulation (ES) and Brain-Computer Interfaces (BCIs). In this review, we summarize the recent progress in biological and engineering strategies for reconstructing neural circuits and promoting functional recovery after SCI, and emphasize current challenges and future directions.

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.

The Influence of Neuron-Extrinsic Factors and Aging on Injury Progression and Axonal Repair in the Central Nervous System

In the aging western population, the average age of incidence for spinal cord injury (SCI) has increased, as has the length of survival of SCI patients. This places great importance on understanding SCI in middle-aged and aging patients. Axon regeneration after injury is an area of study that has received substantial attention and made important experimental progress, however, our understanding of how aging affects this process, and any therapeutic effort to modulate repair, is incomplete. The growth and regeneration of axons is mediated by both neuron intrinsic and extrinsic factors. In this review we explore some of the key extrinsic influences on axon regeneration in the literature, focusing on inflammation and astrogliosis, other cellular responses, components of the extracellular matrix, and myelin proteins. We will describe how each element supports the contention that axonal growth after injury in the central nervous system shows an age-dependent decline, and how this may affect outcomes after a SCI.

Therapeutic repair for spinal cord injury: combinatory approaches to address a multifaceted problem

The recent years saw the advent of promising preclinical strategies that combat the devastating effects of a spinal cord injury (SCI) that are progressing towards clinical trials. However, individually, these treatments produce only modest levels of recovery in animal models of SCI that could hamper their implementation into therapeutic strategies in spinal cord injured humans. Combinational strategies have demonstrated greater beneficial outcomes than their individual components alone by addressing multiple aspects of SCI pathology. Clinical trial designs in the future will eventually also need to align with this notion. The scenario will become increasingly complex as this happens and conversations between basic researchers and clinicians are required to ensure accurate study designs and functional readouts.

Astrocytic YAP Promotes the Formation of Glia Scars and Neural Regeneration after Spinal Cord Injury

Yes-associated protein (YAP) transcriptional coactivator is negatively regulated by the Hippo pathway and functions in controlling the size of multiple organs, such as liver during development. However, it is not clear whether YAP signaling participates in the process of the formation of glia scars after spinal cord injury (SCI). In this study, we found that YAP was upregulated and activated in astrocytes of C57BL/6 male mice after SCI in a Hippo pathway-dependent manner. Conditional knockout (KO) of yap in astrocytes significantly inhibited astrocytic proliferation, impaired the formation of glial scars, inhibited the axonal regeneration, and impaired the behavioral recovery of C57BL/6 male mice after SCI. Mechanistically, the bFGF was upregulated after SCI and induced the activation of YAP through RhoA pathways, thereby promoting the formation of glial scars. Additionally, YAP promoted bFGF-induced proliferation by negatively controlling nuclear distribution of p27^Kip1 mediated by CRM1. Finally, bFGF or XMU-MP-1 (an inhibitor of Hippo kinase MST1/2 to activate YAP) injection indeed activated YAP signaling and promoted the formation of glial scars and the functional recovery of mice after SCI. These findings suggest that YAP promotes the formation of glial scars and neural regeneration of mice after SCI, and that the bFGF-RhoA-YAP-p27^Kip1 pathway positively regulates astrocytic proliferation after SCI.SIGNIFICANCE STATEMENT Glial scars play critical roles in neuronal regeneration of CNS injury diseases, such as spinal cord injury (SCI). Here, we provide evidence for the function of Yes-associated protein (YAP) in the formation of glial scars after SCI through regulation of astrocyte proliferation. As a downstream of bFGF (which is upregulated after SCI), YAP promotes the proliferation of astrocytes through negatively controlling nuclear distribution of p27^Kip1 mediated by CRM1. Activation of YAP by bFGF or XMU-MP-1 injection promotes the formation of glial scar and the functional recovery of mice after SCI. These results suggest that the bFGF-RhoA-YAP-p27^Kip1 axis for the formation of glial scars may be a potential therapeutic strategy for SCI patients.

Therapeutic approaches of trophic factors in animal models and in patients with spinal cord injury

Trophic factors are naturally produced by different tissues that participate in several functions such as the intercellular communication, in the development, stability, differentiation and regeneration at the cellular level. Specifically, in the case of spinal injuries, these factors can stimulate neuronal recovery. They are applied both in experimental models and in clinical trials in patients. The trophic factors analysed in this review include gonadotropin-releasing hormone (GnRH), thyrotropin-releasing hormone (TRH), growth hormone (GH), melatonin, oestrogens, the family of fibroblast growth factors (FGFs), the family of neurotrophins and the glial cell-derived neurotrophic factor (GDNF). There are some trophic (neurotrophic) factors that already been tested in patients with spinal cord injury (SCI), but only shown partial recovery effect. It is possible that, the administration of these trophic factors together with physical rehabilitation, act synergistically and, therefore, significantly improve the quality of life of patients with SCI.

Spinal cord injury: pathophysiology, treatment strategies, associated challenges, and future implications

Axonal regeneration and formation of tripartite (axo-glial) junctions at damaged sites is a prerequisite for early repair of injured spinal cord. Transplantation of stem cells at such sites of damage which can generate both neuronal and glial population has gained impact in terms of recuperation upon infliction with spinal cord injury. In spite of the fact that a copious number of pre-clinical studies using different stem/progenitor cells have shown promising results at acute and subacute stages, at the chronic stages of injury their recovery rates have shown a drastic decline. Therefore, developing novel therapeutic strategies are the need of the hour in order to assuage secondary morbidity and effectuate improvement of the spinal cord injury (SCI)-afflicted patients' quality of life. The present review aims at providing an overview of the current treatment strategies and also gives an insight into the potential cell-based therapies for the treatment of SCI.

Filling the Gap: Neural Stem Cells as A Promising Therapy for Spinal Cord Injury

Spinal cord injury (SCI) can lead to severe motor, sensory and social impairments having a huge impact on patients’ lives. The complex and time-dependent SCI pathophysiology has been hampering the development of novel and effective therapies. Current treatment options include surgical interventions, to stabilize and decompress the spinal cord, and rehabilitative care, without providing a cure for these patients. Novel therapies have been developed targeting different stages during trauma. Among them, cell-based therapies hold great potential for tissue regeneration after injury. Neural stem cells (NSCs), which are multipotent cells with inherent differentiation capabilities committed to the neuronal lineage, are especially relevant to promote and reestablish the damaged neuronal spinal tracts. Several studies demonstrate the regenerative effects of NSCs in SCI after transplantation by providing neurotrophic support and restoring synaptic connectivity. Therefore, human clinical trials have already been launched to assess safety in SCI patients. Here, we review NSC-based experimental studies in a SCI context and how are they currently being translated into human clinical trials.

Glycosaminoglycans from Alzheimer's disease hippocampus have altered capacities to bind and regulate growth factors activities and to bind tau

Glycosaminoglycans (GAGs), including heparan sulfates and chondroitin sulfates, are major components of the extracellular matrix. Upon interacting with heparin binding growth factors (HBGF), GAGs participate to the maintaintenance of tissue homeostasis and contribute to self-healing. Although several processes regulated by HBGF are altered in Alzheimer’s disease, it is unknown whether the brain GAG capacities to bind and regulate the function of HBGF or of other heparin binding proteins, as tau, are modified in this disease. Here, we show that total sulfated GAGs from hippocampus of Alzheimer’s disease have altered capacities to bind and potentiate the activities of growth factors including FGF-2, VEGF, and BDNF while their capacity to bind to tau is remarkable increased. Alterations of GAG structures and capacities to interact with and regulate the activity of heparin binding proteins might contribute to impaired tissue homeostasis in the Alzheimer’s disease brain.