Preparation of PLCL/ECM nerve conduits by electrostatic spinning technique and evaluationin vitroandin vivo.

Objective. Artificial nerve scaffolds composed of polymers have attracted great attention as an alternative for autologous nerve grafts recently. Due to their poor bioactivity, satisfactory nerve repair could not be achieved. To solve this problem, we introduced extracellular matrix (ECM) to optimize the materials.Approach.In this study, the ECM extracted from porcine nerves was mixed with Poly(L-Lactide-co-ϵ-caprolactone) (PLCL), and the innovative PLCL/ECM nerve repair conduits were prepared by electrostatic spinning technology. The novel conduits were characterized by scanning electron microscopy (SEM), tensile properties, and suture retention strength test for micromorphology and mechanical strength. The biosafety and biocompatibility of PLCL/ECM nerve conduits were evaluated by cytotoxicity assay with Mouse fibroblast cells and cell adhesion assay with RSC 96 cells, and the effects of PLCL/ECM nerve conduits on the gene expression in Schwann cells was analyzed by real-time polymerase chain reaction (RT-PCR). Moreover, a 10 mm rat (Male Wistar rat) sciatic defect was bridged with a PLCL/ECM nerve conduit, and nerve regeneration was evaluated by walking track, mid-shank circumference, electrophysiology, and histomorphology analyses.Main results.The results showed that PLCL/ECM conduits have similar microstructure and mechanical strength compared with PLCL conduits. The cytotoxicity assay demonstrates better biosafety and biocompatibility of PLCL/ECM nerve conduits. And the cell adhesion assay further verifies that the addition of ECM is more beneficial to cell adhesion and proliferation. RT-PCR showed that the PLCL/ECM nerve conduit was more favorable to the gene expression of functional proteins of Schwann cells. Thein vivoresults indicated that PLCL/ECM nerve conduits possess excellent biocompatibility and exhibit a superior capacity to promote peripheral nerve repair.Significance.The addition of ECM significantly improved the biocompatibility and bioactivity of PLCL, while the PLCL/ECM nerve conduit gained the appropriate mechanical strength from PLCL, which has great potential for clinical repair of peripheral nerve injuries.

The response of Dual-leucine zipper kinase (DLK) to nocodazole: Evidence for a homeostatic cytoskeletal repair mechanism.

Genetic and pharmacological perturbation of the cytoskeleton enhances the regenerative potential of neurons. This response requires Dual-leucine Zipper Kinase (DLK), a neuronal stress sensor that is a central regulator of axon regeneration and degeneration. The damage and repair aspects of this response are reminiscent of other cellular homeostatic systems, suggesting that a cytoskeletal homeostatic response exists. In this study, we propose a framework for understanding DLK mediated neuronal cytoskeletal homeostasis. We demonstrate that low dose nocodazole treatment activates DLK signaling. Activation of DLK signaling results in a DLK-dependent transcriptional signature, which we identify through RNA-seq. This signature includes genes likely to attenuate DLK signaling while simultaneously inducing actin regulating genes. We identify alterations to the cytoskeleton including actin-based morphological changes to the axon. These results are consistent with the model that cytoskeletal disruption in the neuron induces a DLK-dependent homeostatic mechanism, which we term the Cytoskeletal Stress Response (CSR) pathway.

Recent advances in enhances peripheral nerve orientation: the synergy of micro or nano patterns with therapeutic tactics.

Several studies suggest that topographical patterns influence nerve cell fate. Efforts have been made to improve nerve cell functionality through this approach, focusing on therapeutic strategies that enhance nerve cell function and support structures. However, inadequate nerve cell orientation can impede long-term efficiency, affecting nerve tissue repair. Therefore, enhancing neurites/axons directional growth and cell orientation is crucial for better therapeutic outcomes, reducing nerve coiling, and ensuring accurate nerve fiber connections. Conflicting results exist regarding the effects of micro- or nano-patterns on nerve cell migration, directional growth, immunogenic response, and angiogenesis, complicating their clinical use. Nevertheless, advances in lithography, electrospinning, casting, and molding techniques to intentionally control the fate and neuronal cells orientation are being explored to rapidly and sustainably improve nerve tissue efficiency. It appears that this can be accomplished by combining micro- and nano-patterns with nanomaterials, biological gradients, and electrical stimulation. Despite promising outcomes, the unclear mechanism of action, the presence of growth cones in various directions, and the restriction of outcomes to morphological and functional nerve cell markers have presented challenges in utilizing this method. This review seeks to clarify how micro- or nano-patterns affect nerve cell morphology and function, highlighting the potential benefits of cell orientation, especially in combined approaches.

Dental Pulp Stem Cell-Derived Exosomes Promote Sciatic Nerve Regeneration via Optimizing Schwann Cell Function.

Repair strategies for injured peripheral nerve have achieved great progresses in recent years. However, the clinical outcomes remain unsatisfactory. Recent studies have found that exosomes secreted by dental pulp stem cells (DPSC-exos) have great potential for applications in nerve repair. In this study, we evaluated the effects of human DPSC-exos on improving peripheral nerve regeneration. Initially, we established a coculture system between DPSCs and Schwann cells (SCs) in vitro to assess the effect of DPSC-exos on the activity of embryonic dorsal root ganglion neurons (DRGs) growth in SCs. We extracted and labeled human DPSC-exos, which were subsequently utilized in uptake experiments in DRGs and SCs. Subsequently, we established a rat sciatic nerve injury model to evaluate the therapeutic potential of DPSC-exos in repairing sciatic nerve damage. Our findings revealed that DPSC-exos significantly promoted neurite elongation by enhancing the proliferation, migration, and secretion of neurotrophic factors by SCs. In vivo, DPSC-exos administration significantly improved the walking behavior, axon regeneration, and myelination in rats with sciatic nerve injuries. Our study underscores the vast potential of DPSC-exos as a therapeutic tool for tissue-engineered nerve construction.

Strategies to enhance the ability of nerve guidance conduits to promote directional nerve growth.

Severely damaged peripheral nerves will regenerate incompletely due to lack of directionality in their regeneration, leading to loss of nerve function. To address this problem, various nerve guidance conduits (NGCs) have been developed to provide guidance for nerve repair. However, their clinical application is still limited, mainly because its effect in promoting nerve repair is not as good as autologous nerve transplantation. Therefore, it is necessary to enhance the ability of NGCs to promote directional nerve growth. Strategies include preparing various directional structures on NGCs to provide contact guidance, and loading various substances on them to provide electrical stimulation or neurotrophic factor concentration gradient to provide directional physical or biological signals.

Boundary cap neural crest stem cells promote angiogenesis after transplantation to avulsed dorsal roots in mice and induce migration of endothelial cells in 3D printed scaffolds.

Dorsal root avulsion injuries lead to loss of sensation and to reorganization of blood vessels (BVs) in the injured area. The inability of injured sensory axons to re-enter the spinal cord results in permanent loss of sensation, and often also leads to the development of neuropathic pain. Approaches that restore connection between peripheral sensory axons and their CNS targets are thus urgently need. Previous research has shown that sensory axons from peripherally grafted human sensory neurons are able to enter the spinal cord by growing along BVs which penetrate the CNS from the spinal cord surface. In this study we analysed the distribution of BVs after avulsion injury and how their pattern is affected by implantation at the injury site of boundary cap neural crest stem cells (bNCSCs), a transient cluster of cells, which are located at the boundary between the spinal cord and peripheral nervous system and assist the growth of sensory axons from periphery into the spinal cord during development. The superficial dorsal spinal cord vasculature was examined using intravital microscopy and intravascular BV labelling. bNCSC transplantation increased vascular volume in a non-dose responsive manner, whereas dorsal root avulsion alone did not decrease the vascular volume. To determine whether bNCSC are endowed with angiogenic properties we prepared 3D printed scaffolds, containing bNCSCs together with rings prepared from mouse aorta. We show that bNCSC do induce migration and assembly of endothelial cells in this system. These findings suggest that bNCSC transplant can promote vascularization in vivo and contribute to BV formation in 3D printed scaffolds.

Neutrophil-inflicted vasculature damage suppresses immune-mediated optic nerve regeneration.

In adult mammals, injured retinal ganglion cells (RGCs) fail to spontaneously regrow severed axons, resulting in permanent visual deficits. Robust axon growth, however, is observed after intra-ocular injection of particulate ß-glucan isolated from yeast. Blood-borne myeloid cells rapidly respond to ß-glucan, releasing numerous pro-regenerative factors. Unfortunately, the pro-regenerative effects are undermined by retinal damage inflicted by an overactive immune system. Here, we demonstrate that protection of the inflamed vasculature promotes immune-mediated RGC regeneration. In the absence of microglia, leakiness of the blood-retina barrier increases, pro-inflammatory neutrophils are elevated, and RGC regeneration is reduced. Functional ablation of the complement receptor 3 (CD11b/integrin-αM), but not the complement components C1q-/- or C3-/-, reduces ocular inflammation, protects the blood-retina barrier, and enhances RGC regeneration. Selective targeting of neutrophils with anti-Ly6G does not increase axogenic neutrophils but protects the blood-retina barrier and enhances RGC regeneration. Together, these findings reveal that protection of the inflamed vasculature promotes neuronal regeneration.

Ca2+/Calmodulin-Dependent Protein Kinase II Enhances Retinal Ganglion Cell Survival But Suppresses Axon Regeneration after Optic Nerve Injury.

Neuroprotection after injury or in neurodegenerative disease remains a major goal for basic and translational neuroscience. Retinal ganglion cells (RGCs), the projection neurons of the eye, degenerate in optic neuropathies after axon injury, and there are no clinical therapies to prevent their loss or restore their connectivity to targets in the brain. Here we demonstrate a profound neuroprotective effect of the exogenous expression of various Ca2+/calmodulin-dependent protein kinase II (CaMKII) isoforms in mice. A dramatic increase in RGC survival following the optic nerve trauma was elicited by the expression of constitutively active variants of multiple CaMKII isoforms in RGCs using adeno-associated viral (AAV) vectors across a 100-fold range of AAV dosing in vivo. Despite this neuroprotection, however, short-distance RGC axon sprouting was suppressed by CaMKII, and long-distance axon regeneration elicited by several pro-axon growth treatments was likewise inhibited even as CaMKII further enhanced RGC survival. Notably, in a dose-escalation study, AAV-expressed CaMKII was more potent for axon growth suppression than the promotion of survival. That diffuse overexpression of constitutively active CaMKII strongly promotes RGC survival after axon injury may be clinically valuable for neuroprotection per se. However, the associated strong suppression of the optic nerve axon regeneration demonstrates the need for understanding the intracellular domain- and target-specific CaMKII activities to the development of CaMKII signaling pathway-directed strategies for the treatment of optic neuropathies.

Skin Reinnervation by Collateral Sprouting Following Spared Nerve Injury in Mice.

Following peripheral nerve injury, denervated tissues can be reinnervated via regeneration of injured neurons or collateral sprouting of neighboring uninjured afferents into denervated territory. While there has been substantial focus on mechanisms underlying regeneration, collateral sprouting has received less attention. Here, we used immunohistochemistry and genetic neuronal labeling to define the subtype specificity of sprouting-mediated reinnervation of plantar hindpaw skin in the mouse spared nerve injury (SNI) model, in which productive regeneration cannot occur. Following initial loss of cutaneous afferents in the tibial nerve territory, we observed progressive centripetal reinnervation by multiple subtypes of neighboring uninjured fibers into denervated glabrous and hairy plantar skin of male mice. In addition to dermal reinnervation, CGRP-expressing peptidergic fibers slowly but continuously repopulated denervated epidermis, Interestingly, GFRα2-expressing nonpeptidergic fibers exhibited a transient burst of epidermal reinnervation, followed by a trend towards regression. Presumptive sympathetic nerve fibers also sprouted into denervated territory, as did a population of myelinated TrkC lineage fibers, though the latter did so inefficiently. Conversely, rapidly adapting Aß fiber and C fiber low threshold mechanoreceptor (LTMR) subtypes failed to exhibit convincing sprouting up to 8 weeks after nerve injury in males or females. Optogenetics and behavioral assays in male mice further demonstrated the functionality of collaterally sprouted fibers in hairy plantar skin with restoration of punctate mechanosensation without hypersensitivity. Our findings advance understanding of differential collateral sprouting among sensory neuron subpopulations and may guide strategies to promote the progression of sensory recovery or limit maladaptive sensory phenomena after peripheral nerve injury.

[Research progress in functional regeneration methods and mechanisms of taste buds].

Gustation is one of the most important human senses. Taste dysfunctions, which may be due to aging, tongue cancer surgery, radiotherapy and chemotherapy, affect life quality. That is why the need for taste bud regeneration has received more attention. At present, research on development and renewal of taste cells provides a basis for taste bud regeneration; molecular mechanisms related to taste bud regeneration are being continuously uncoverd, aiding in the identification of more accurate targets for therapy. New methods such as nerve regeneration, tissue engineering, and cytokine therapy have emerged. The author reviews the mechanism and the latest methods of taste bud regeneration of lingual epithelium, aiming to open new horizions for the prevention and treatment of gustatory diseases, and provide theoretical references for its regeneration.

TREM2 deficiency impairs the energy metabolism of Schwann cells and exacerbates peripheral neurological deficits.

Triggering receptor expressed on myeloid cells-2 (TREM2) has been implicated in susceptibility to neurodegenerative disease. Schwann cells (SCs), the predominant glial cell type in the peripheral nervous system (PNS), play a crucial role in myelination, providing trophic support for neurons and nerve regeneration. However, the function of TREM2 in SCs has not been fully elucidated. Here, we found that TREM2 is expressed in SCs but not in neurons in the PNS. TREM2 deficiency leads to disruption of glycolytic flux and oxidative metabolism in SCs, impairing cell proliferation. The energy crisis caused by TREM2 deficiency triggers mitochondrial damage and autophagy by activating AMPK and impairing PI3K-AKT-mTOR signaling. Combined metabolomic analysis demonstrated that energic substrates and energy metabolic pathways were significantly impaired in TREM2-deficient SCs. Moreover, TREM2 deficiency impairs energy metabolism and axonal growth in sciatic nerve, accompanied by exacerbation of neurological deficits and suppression of nerve regeneration in a mouse model of acute motor axonal neuropathy. These results indicate that TREM2 is a critical regulator of energy metabolism in SCs and exerts neuroprotective effects on peripheral neuropathy. TREM2 deficiency impairs glycolysis and oxidative metabolism in Schwann cells, resulting in compromised cell proliferation. The energy crisis caused by TREM2 deficiency induces mitochondrial damage and autophagy by activating AMPK and impairing PI3K-AKT-mTOR signaling. Moreover, TREM2 deficiency disrupts the energy metabolism of the sciatic nerve and impairs support for axonal regeneration, accompanied by exacerbation of neurological deficits and suppression of nerve regeneration in a mouse model of acute motor axonal neuropathy (by FigDraw).

Oriented Graphene Oxide Scaffold Promotes Nerve Regeneration in vitro and in vivo.

Background: Treating peripheral nerve injuries (PNI) with defects remains challenging in clinical practice. The commercial conduits have shown suboptimal nerve regeneration and functional recovery due to their basic tubular design without electroactive and oriented topographical cues. Purpose: To develop a new scaffold with oriented microstructure and electroactive Graphene oxide (GO) and investigate its' therapeutic effect on nerve regeneration in vitro and in vivo. Methods: This study employed a straightforward approach to co-spin PCL and GO, yielding an oriented hybrid nanofibrous scaffold known as the O-GO/PCL scaffold. The physical and chemical properties of nanofibrous scaffold were tested by scanning electron microscopy (SEM), transmission electron microscope (TEM), tensile test and so on. Primary Schwann cells (SCs) and dorsal root ganglia (DRG) were used to investigate the impact of the newly developed scaffolds on the biological behavior of neural cells in vitro. Transcriptome sequencing (mRNA-seq) was employed to probe the underlying mechanisms of the synergistic effect of electroactive GO and longitudinal topographic guidance on nerve regeneration. Furthermore, the developed O-GO/PCL scaffold was utilized to bridge a 10-mm sciatic nerve defect in rat, aiming to investigate its therapeutic potential for peripheral nerve regeneration in vivo. Results and discussion: The SEM and TEM revealed that the newly developed O-GO/PCL scaffold showed longitudinally oriented microstructure and GO particles were homogenously and uniformly distributed inside the nanofibers. Primary SCs were utilized to assess the biocompatibility of the GO-based scaffold, revealing that negligible cytotoxicity when GO concentration does not exceed 0.5%. In vitro analysis of nerve regeneration demonstrated that axons in the O-GO/PCL group exhibited an average length of 1054.88 ± 161.32 µm, significant longer than those in the other groups (P < 0.05). Moreover, mRNA sequencing results suggested that the O-GO/PCL scaffold could enhance nerve regeneration by upregulating genes associated with neural regeneration, encompassing ion transport, axon guidance and cell-cell interactions. Most importantly, we employed the O-GO/PCL scaffold to repair a 10-mm sciatic nerve defect in rat, resulting in augmented nerve regeneration, myelination, and functional recovery. Conclusion: The O-GO/PCL scaffold with oriented microstructure and electroactive GO represents a promising heral nerve reconstruction.

Targeting Vasohibins to Promote Axon Regeneration.

Treatments accelerating axon regeneration in the nervous system are still clinically unavailable. However, parthenolide promotes adult sensory neurons' axon growth in culture by inhibiting microtubule detyrosination. Here, we show that overexpression of vasohibins increases microtubule detyrosination in growth cones and compromises growth in culture and in vivo. Moreover, overexpression of these proteins increases the required parthenolide concentrations to promote axon regeneration. At the same time, the partial knockdown of endogenous vasohibins or their enhancer SVBP in neurons facilitates axon growth, verifying them as pharmacological targets for promoting axon growth. In vivo, repeated intravenous application of parthenolide or its prodrug di-methyl-amino-parthenolide (DMAPT) markedly facilitates the regeneration of sensory, motor, and sympathetic axons in injured murine and rat nerves, leading to acceleration of functional recovery. Moreover, orally applied DMAPT was similarly effective in promoting nerve regeneration. Thus, pharmacological inhibition of vasohibins facilitates axon regeneration in different species and nerves, making parthenolide and DMAPT the first promising drugs for curing nerve injury.

Cell Heterogeneity and Variability in Peripheral Nerve after Injury.

With the development of single-cell sequencing technology, the cellular composition of more and more tissues is being elucidated. As the whole nervous system has been extensively studied, the cellular composition of the peripheral nerve has gradually been revealed. By summarizing the current sequencing data, we compile the heterogeneities of cells that have been reported in the peripheral nerves, mainly the sciatic nerve. The cellular variability of Schwann cells, fibroblasts, immune cells, and endothelial cells during development and disease has been discussed in this review. The discovery of the architecture of peripheral nerves after injury benefits the understanding of cellular complexity in the nervous system, as well as the construction of tissue engineering nerves for nerve repair and axon regeneration.

Remyelination in the Central Nervous System.

The inability of the mammalian central nervous system (CNS) to undergo spontaneous regeneration has long been regarded as a central tenet of neurobiology. However, while this is largely true of the neuronal elements of the adult mammalian CNS, save for discrete populations of granule neurons, the same is not true of its glial elements. In particular, the loss of oligodendrocytes, which results in demyelination, triggers a spontaneous and often highly efficient regenerative response, remyelination, in which new oligodendrocytes are generated and myelin sheaths are restored to denuded axons. Yet remyelination in humans is not without limitation, and a variety of demyelinating conditions are associated with sustained and disabling myelin loss. In this work, we will (1) review the biology of remyelination, including the cells and signals involved; (2) describe when remyelination occurs and when and why it fails, including the consequences of its failure; and (3) discuss approaches for therapeutically enhancing remyelination in demyelinating diseases of both children and adults, both by stimulating endogenous oligodendrocyte progenitor cells and by transplanting these cells into demyelinated brain.

Rab32 facilitates Schwann cell pyroptosis in rats following peripheral nerve injury by elevating ROS levels.

BACKGROUND: Peripheral nerve injury (PNI) is commonly observed in clinical practice, yet the underlying mechanisms remain unclear. This study investigated the correlation between the expression of a Ras-related protein Rab32 and pyroptosis in rats following PNI, and potential mechanisms have been explored by which Rab32 may influence Schwann cells pyroptosis and ultimately peripheral nerve regeneration (PNR) through the regulation of Reactive oxygen species (ROS) levels. METHODS: The authors investigated the induction of Schwann cell pyroptosis and the elevated expression of Rab32 in a rat model of PNI. In vitro experiments revealed an upregulation of Rab32 during Schwann cell pyroptosis. Furthermore, the effect of Rab32 on the level of ROS in mitochondria in pyroptosis model has also been studied. Finally, the effects of knocking down the Rab32 gene on PNR were assessed, morphology, sensory and motor functions of sciatic nerves, electrophysiology and immunohistochemical analysis were conducted to assess the therapeutic efficacy. RESULTS: Silencing Rab32 attenuated PNI-induced Schwann cell pyroptosis and promoted peripheral nerve regeneration. Furthermore, our findings demonstrated that Rab32 induces significant oxidative stress by damaging the mitochondria of Schwann cells in the pyroptosis model in vitro. CONCLUSION: Rab32 exacerbated Schwann cell pyroptosis in PNI model, leading to delayed peripheral nerve regeneration. Rab32 can be a potential target for future therapeutic strategy in the treatment of peripheral nerve injuries.

[Nerve Transfers in Peripheral Nerve Lesions]. / Nerventransfers bei peripheren Nervenläsionen.

BACKGROUND: Lesions of peripheral nerves of the upper extremities often lead to persistent, serious limitations in motor function and sensory perception. Affected patients suffer from both private and professional restrictions associated with long-term physical, psychological and socioeconomic consequences. INDICATION: An early indication for a nerve transfer shortens the reinnervation distance and improves the growing of motor and sensory axons into the target organ to facilitate early mobility and sensitivity. When planning the timepoint of the surgical procedure, the distance to be covered by reinnervation as well as the morbidities of donor nerves must be considered individually. RESULTS: Nerve transfers can achieve earlier and safer reinnervation to improve motor and sensory functions after nerve injuries in the upper extremity.

Appropriate dosage, timing, and site of intramuscular injections of brain-derived neurotrophic factor (BDNF) promote motor recovery after facial nerve injury in rats.

INTRODUCTION/AIMS: Daily intramuscular injections of fibroblast growth factor 2 (FGF2) but not of brain-derived neurotrophic factor (BDNF) significantly improve whisking behavior and mono-innervation of the rat levator labii superioris (LLS) muscle 56 days after buccal nerve transection and suture (buccal-buccal anastomosis, BBA). We explored the dose-response of BDNF, FGF2, and insulin growth factor 2 (IGF2) on the same parameters, asking whether higher doses of BDNF would promote recovery. METHODS: After BBA, growth factors were injected (30 µL volume) daily into the LLS muscle over 14, 28, or 56 days. At 56 days, video-based motion analysis of vibrissal whisking was performed and the extent of mono- and poly-reinnervation of the reinnervated neuromuscular junctions (NMJs) of the muscle determined with immunostaining of the nerve with ß-tubulin and histochemical staining of the endplates with Alexa Fluor 488-conjugated α-bungarotoxin. RESULTS: The dose-response curve demonstrated significantly higher whisking amplitudes and corresponding increased mono-innervation of the NMJ in the reinnervated LLS muscle at concentrations of 20-30 µg/mL BDNF administered daily for 14-28 days after BBA surgery. In contrast, high doses of IGF2 and FGF2, or doses of 20 and 40 µg/mL of BDNF administered for 14-56 days had no effect on either whisking behavior or in reducing poly-reinnervation of endplates in the muscle. DISCUSSION: These data suggest that the re-establishment of mono-innervation of whiskerpad muscles and the improved motor function by injections of BDNF into the paralyzed vibrissal musculature after facial nerve injury have translation potential and promote clinical application.

Peripheral neural interfaces: Skeletal muscles are hyper-reinnervated according to the axonal capacity of the surgically rewired nerves.

Advances in robotics have outpaced the capabilities of man-machine interfaces to decipher and transfer neural information to and from prosthetic devices. We emulated clinical scenarios where high- (facial) or low-neural capacity (ulnar) donor nerves were surgically rewired to the sternomastoid muscle, which is controlled by a very small number of motor axons. Using retrograde tracing and electrophysiological assessments, we observed a nearly 15-fold functional hyper-reinnervation of the muscle after high-capacity nerve transfer, demonstrating its capability of generating a multifold of neuromuscular junctions. Moreover, the surgically redirected axons influenced the muscle's physiological characteristics, by altering the expression of myosin heavy-chain types in alignment with the donor nerve. These findings highlight the remarkable capacity of skeletal muscles to act as biological amplifiers of neural information from the spinal cord for governing bionic prostheses, with the potential of expressing high-dimensional neural function for high-information transfer interfaces.

The involvement of Neuregulin-1 in the process of facial nerve injury repair through the utilization of dental pulp stem cells.

BACKGROUND: Facial nerve injury often results in poor prognosis due to the challenging process of nerve regeneration. Neuregulin-1, a human calmodulin, is under investigation in this study for its impact on the reparative capabilities of Dental Pulp Stem Cells (DPSCs) in facial nerve injury. METHODS: Lentivirus was used to transfect and construct Neuregulin-1 overexpressed DPSCs. Various techniques assessed the effects of Neuregulin-1: osteogenic induction, lipid induction, Reverse Transcription Polymerase Chain Reaction, Western Blot, Cell Counting Kit-8 assay, wound healing, immunofluorescence, Phalloidin staining, nerve stem action potential, Hematoxylin-eosin staining, transmission electron microscopy, and immunohistochemistry. RESULTS: Neuregulin-1 effectively enhanced the proliferation, migration, and cytoskeletal rearrangement of DPSCs, while simultaneously suppressing the expression of Ras homolog gene family member A (RhoA) and Microfilament actin (F-actin). These changes facilitated the neural differentiation of DPSCs. Additionally, in vivo experiments showed that Neuregulin-1 expedited the restoration of action potential in the facial nerve trunk, increased the thickness of the myelin sheath, and stimulated axon regeneration. CONCLUSION: Neuregulin-1 has the capability to facilitate the repair of facial nerve injuries by promoting the regenerative capacity of DPSCs. Thus, Neuregulin-1 is a significant potential gene in the reparative processes of nerve damage.