OBJECTIVE: To investigate the effects of removing microglia from spinal cord on nerve repair and functional recovery after spinal cord injury (SCI) in mice. METHODS: Thirty-nine 6-week-old female C57BL/6 mice were randomly divided into control group ( n=12), SCI group ( n=12), and PLX3397+SCI group ( n=15). The PLX3397+SCI group received continuous feeding of PLX3397, a colony-stimulating factor 1 receptor inhibitor, while the other two groups were fed a standard diet. After 14 days, both the SCI group and the PLX3397+SCI group were tested for ionized calcium binding adapter molecule 1 (Iba1) to confirm that the PLX3397+SCI group had completely depleted the spinal cord microglia. The SCI model was then prepared by clamping the spinal cord in both the SCI group and the PLX3397+SCI group, while the control group underwent laminectomy. Preoperatively and at 1, 3, 7, 14, 21, and 28 days postoperatively, the Basso Mouse Scale (BMS) was used to assess the hind limb function of mice in each group. At 28 days, a footprint test was conducted to observe the gait of the mice. After SCI, spinal cord tissue from the injury site was taken, and Iba1 immunofluorescence staining was performed at 7 days to observe the aggregation and proliferation of microglia in the spinal cord. HE staining was used to observe the formation of glial scars at the injury site at 28 days; glial fibrillary acidic protein (GFAP) immunofluorescence staining was applied to astrocytes to assess the extent of the injured area; neuronal nuclei antigen (NeuN) immunofluorescence staining was used to evaluate neuronal survival. And 5-hydroxytryptamine (5-HT) immunofluorescence staining was performed to assess axonal survival at 60 days. RESULTS: All mice survived until the end of the experiment. Immunofluorescence staining revealed that the microglia in the spinal cord of the PLX3397+SCI group decreased by more than 95% compared to the control group after 14 days of continuous feeding with PLX3397 ( P<0.05). Compared to the control group, the BMS scores in the PLX3397+SCI group and the SCI group significantly decreased at different time points after SCI ( P<0.05). Moreover, the PLX3397+SCI group showed a further decrease in BMS scores compared to the SCI group, and exhibited a dragging gait. The differences between the two groups were significant at 14, 21, and 28 days ( P<0.05). HE staining at 28 days revealed that the SCI group had formed a well-defined and dense gliotic scar, while the PLX3397+SCI group also developed a gliotic scar, but with a more blurred and loose boundary. Immunofluorescence staining revealed that the number of microglia near the injury center at 7 days increased in the SCI group than in the control group, but the difference between groups was not significant ( P>0.05). In contrast, the PLX3397+SCI group showed a significant reduction in microglia compared to both the control and SCI groups ( P<0.05). At 28 days after SCI, the area of spinal cord injury in the PLX3397+SCI group was significantly larger than that in SCI group ( P<0.05); the surviving neurons significantly reduced compared with the control group and SCI group ( P<0.05). The axonal necrosis and retraction at 60 days after SCI were more obvious. CONCLUSION The removal of microglia in the spinal cord aggravate the tissue damage after SCI and affecte the recovery of motor function in mice, suggesting that microglia played a neuroprotective role in SCI.
Animals ; Spinal Cord Injuries/surgery* ; Microglia/pathology* ; Female ; Mice ; Mice, Inbred C57BL ; Nerve Regeneration/drug effects* ; Spinal Cord/pathology* ; Pyrroles/administration & dosage* ; Aminopyridines/administration & dosage* ; Recovery of Function ; Disease Models, Animal ; Calcium-Binding Proteins/metabolism* ; Receptors, Granulocyte-Macrophage Colony-Stimulating Factor/antagonists & inhibitors* ; Microfilament Proteins/metabolism* ; Glial Fibrillary Acidic Protein/metabolism*

OBJECTIVE: To review the research progress on silk fibroin (SF)-nerve guidance conduits (NGCs) for peripheral nerve injury (PNI) repair. METHODS: To review the recent literature on PNI and SF-NGCs, expound the concepts and treatment strategies of PNI, and summarize the construction of SF-NGCs and its application in PNI repair. RESULTS: Autologous nerve transplantation remains the "gold standard" for treating severe PNI. However, it's clinical applications are constrained by the limitations of limited donors and donor area damage. Natural SF exhibits good biocompatibility, low immunogenicity, and excellent physicochemical properties, making it an ideal candidate for the construction of NGCs. SF-NGCs constructed using different technologies have been found to have better biocompatibility and bioactivity. Their configurations can facilitate nerve regeneration by enhancing regenerative guidance and axonal extension. Besides, the adhesion, proliferation and differentiation of neurons and Schwann cells related to PNI repair can be effectively promote by NGCs. This accelerates the speed of nerve regeneration and improves the efficiency of repair. In addition, SF-NGCs can be used as regenerative scaffolds to provide biological templates for nerve repair. CONCLUSION The biodegradable natural SF has been extensively studied and demonstrated promising application prospects in the field of NGCs. It might be an effective and viable alternative to the "gold standard" for PNI treatment.
Fibroins/chemistry* ; Peripheral Nerve Injuries/therapy* ; Nerve Regeneration ; Tissue Scaffolds/chemistry* ; Humans ; Guided Tissue Regeneration/methods* ; Biocompatible Materials ; Animals ; Tissue Engineering/methods* ; Schwann Cells/cytology* ; Peripheral Nerves ; Neurons/cytology*

OBJECTIVE: To review recent research progress in the use of auxiliary components of nerve conduits for the treatment of peripheral nerve injuries. METHODS: An extensive review of recent domestic and international literature was conducted to evaluate the role of auxiliary components in nerve conduits for peripheral nerve repair, with a focus on their effects and underlying mechanisms. RESULTS: By incorporating auxiliary components such as bioactive molecules, therapeutic cells, and their derivatives, nerve conduits can create a more biomimetic regenerative microenvironment. This is achieved by providing neurotrophic support, modulating the immune microenvironment, improving blood and oxygen supply, and offering directional guidance for nerve regeneration. Consequently, the nerve conduit is transformed from a simple physical scaffold into an active, bio-functional repair system, which enhances the effectiveness for PNI. CONCLUSION While nerve conduits augmented with auxiliary components demonstrate improved effectiveness, further advancements are required in drug delivery systems and the integration of cellular components. Moreover, most current studies are based on animal or in vitro experiments. Randomized controlled clinical trials are necessary to validate their clinical effectiveness.
Peripheral Nerve Injuries/surgery* ; Nerve Regeneration ; Humans ; Tissue Scaffolds ; Animals ; Guided Tissue Regeneration/methods* ; Tissue Engineering/methods* ; Biocompatible Materials ; Peripheral Nerves ; Drug Delivery Systems

In recent years, the study of single-cell transcriptome sequencing technology in the heterogeneity of astrocytes (astrocytes) after spinal cord injury (SCI) has provided new perspectives on post-traumatic nerve regeneration and repair. To provide a review on the research progress of single-cell sequencing technology in astrocytes after spinal cord injury (SCI), and to more comprehensively and deeply elaborate the application of single-cell sequencing technology in the field of astrocytes after SCI. Single-cell sequencing technology can analyse the transcriptomes of individual cells in a high-throughput manner, thus revealing fine differences in cell types and states. By using single-cell sequencing technology, the heterogeneity of astrocytes after SCI and their association with nerve regeneration and repair were revealed. In conclusion, the application of single-cell sequencing technology provides an important tool to reveal the heterogeneity of astrocytes after SCI, to further explore the mechanisms of astrocytes in SCI, and to develop intervention strategies targeting their regulatory mechanisms in order to improve the therapeutic efficacy of SCI. The discovery of changes in astrocyte transcriptome dynamics has improved researchers' understanding of spinal cord injury lesion progression and provided new insights into the treatment of spinal cord injury at different time points. To date, all of these findings need to be validated by more basic research and sufficient clinical trials. In the future, single-cell sequencing technology, through interdisciplinary collaboration with bioinformatics, computer science, tissue engineering, and clinical medicine, is expected to open a new window for the treatment of spinal cord injury.
Spinal Cord Injuries/metabolism* ; Astrocytes/cytology* ; Single-Cell Analysis/methods* ; Humans ; Animals ; Transcriptome ; Nerve Regeneration

Yes-associated protein (YAP), the key transcriptional co-factor and downstream effector of the Hippo pathway, has emerged as one of the primary regulators of neural as well as glial cells. It has been detected in various glial cell types, including Schwann cells and olfactory ensheathing cells in the peripheral nervous system, as well as radial glial cells, ependymal cells, Bergmann glia, retinal Müller cells, astrocytes, oligodendrocytes, and microglia in the central nervous system. With the development of neuroscience, understanding the functions of YAP in the physiological or pathological processes of glia is advancing. In this review, we aim to summarize the roles and underlying mechanisms of YAP in glia and glia-related neurological diseases in an integrated perspective.
Humans ; Animals ; Neuroglia/metabolism* ; Signal Transduction/physiology* ; YAP-Signaling Proteins ; Nerve Regeneration/physiology* ; Nervous System Diseases/metabolism* ; Adaptor Proteins, Signal Transducing/metabolism*

Acute mitochondrial damage and the energy crisis following axonal injury highlight mitochondrial transport as an important target for axonal regeneration. Syntaphilin (Snph), known for its potent mitochondrial anchoring action, has emerged as a significant inhibitor of both mitochondrial transport and axonal regeneration. Therefore, investigating the molecular mechanisms that influence the expression levels of the snph gene can provide a viable strategy to regulate mitochondrial trafficking and enhance axonal regeneration. Here, we reveal the inhibitory effect of microRNA-146b (miR-146b) on the expression of the homologous zebrafish gene syntaphilin b (snphb). Through CRISPR/Cas9 and single-cell electroporation, we elucidated the positive regulatory effect of the miR-146b-snphb axis on Mauthner cell (M-cell) axon regeneration at the global and single-cell levels. Through escape response tests, we show that miR-146b-snphb signaling positively regulates functional recovery after M-cell axon injury. In addition, continuous dynamic imaging in vivo showed that reprogramming miR-146b significantly promotes axonal mitochondrial trafficking in the pre-injury and early stages of regeneration. Our study reveals an intrinsic axonal regeneration regulatory axis that promotes axonal regeneration by reprogramming mitochondrial transport and anchoring. This regulation involves noncoding RNA, and mitochondria-associated genes may provide a potential opportunity for the repair of central nervous system injury.
Animals ; Zebrafish ; MicroRNAs/genetics* ; Nerve Regeneration/physiology* ; Mitochondria/metabolism* ; Zebrafish Proteins/genetics* ; Axons/metabolism* ; Signal Transduction/physiology* ; Axonal Transport/physiology* ; Nerve Tissue Proteins/genetics*

Schwann cells and macrophages are the main immune cells involved in peripheral nerve injury. After injury, Schwann cells produce an inflammatory response and secrete various chemokines, inflammatory factors, and some other cytokines to promote the recruitment and M2 polarization of blood-derived macrophages, enhancing their phagocytotic ability, and thus play an important role in promoting nerve regeneration. Macrophages have also been found to promote vascular regeneration after injury, promote the migration and proliferation of Schwann cells along blood vessels, and facilitate myelination and axon regeneration. Therefore, there is a close interaction between Schwann cells and macrophages during peripheral nerve regeneration, but this has not been systematically summarized. In this review, the mechanisms of action of Schwann cells and macrophages in each other's migration and phenotypic transformation are reviewed from the perspective of each other, to provide directions for research on accelerating nerve injury repair.
Schwann Cells/metabolism* ; Peripheral Nerve Injuries/physiopathology* ; Animals ; Macrophages/immunology* ; Nerve Regeneration/physiology* ; Humans ; Cell Movement/physiology*

Neuronal reprogramming is an innovative technique for converting non-neuronal somatic cells into neurons that can be used to replace lost or damaged neurons, providing a potential effective therapeutic strategy for central nervous system (CNS) injuries or diseases. Transcription factors have been used to induce neuronal reprogramming, while their reprogramming efficiency is relatively low, and the introduction of exogenous genes may result in host gene instability or induce gene mutation. Therefore, their future clinical application may be hindered by these safety concerns. Compared with transcription factors, small-molecule compounds have unique advantages in the field of neuronal reprogramming, which can overcome many limitations of traditional transcription factor-induced neuronal reprogramming. Here, we review the recent progress in the research of small-molecule compound-mediated neuronal reprogramming and its application in CNS regeneration and repair.
Humans ; Cellular Reprogramming/drug effects* ; Neurons/cytology* ; Animals ; Transcription Factors ; Small Molecule Libraries/pharmacology* ; Nerve Regeneration

The neurophysiological mechanisms by which exercise improves cognitive function have not been fully elucidated. A comprehensive and systematic review of current domestic and international neurophysiological evidence on exercise improving cognitive function was conducted from multiple perspectives. At the molecular level, exercise promotes nerve cell regeneration and synaptogenesis and maintains cellular development and homeostasis through the modulation of a variety of neurotrophic factors, receptor activity, neuropeptides, and monoamine neurotransmitters, and by decreasing the levels of inflammatory factors and other modulators of neuroplasticity. At the cellular level, exercise enhances neural activation and control and improves brain structure through nerve regeneration, synaptogenesis, improved glial cell function and angiogenesis. At the structural level of the brain, exercise promotes cognitive function by affecting white and gray matter volumes, neural activation and brain region connectivity, as well as increasing cerebral blood flow. This review elucidates how exercise improves the internal environment at the molecular level, promotes cell regeneration and functional differentiation, and enhances the brain structure and neural efficiency. It provides a comprehensive, multi-dimensional explanation of the neurophysiological mechanisms through which exercise promotes cognitive function.
Animals ; Humans ; Brain/physiology* ; Cognition/physiology* ; Exercise/physiology* ; Nerve Regeneration/physiology* ; Neuronal Plasticity/physiology*

Pericytes are multifunctional mural cells that surround the abluminal wall of endothelial cells and are associated with vascular development, vascular permeability, and angiogenesis. Additionally, pericytes demonstrate stem cell-like properties and contribute to neuroinflammatory processes. Pericytes have been extensively studied in the central nervous system. However, specific mechanisms underlying its involvement in various physiological and pathological conditions, especially in erectile dysfunction (ED), remain poorly understood. Advancements in in vitro and in vitro techniques, such as single-cell RNA sequencing, are expanding our understanding of pericytes. Recent studies have shown that pericyte dysfunction is considered an important factor in the pathogenesis of vascular and neurological ED. Therefore, this study aims to analyze the specific role of pericytes in ED, focusing on diabetic and neurogenic ED. This article provides a comprehensive review of research findings on PubMed from 2000 to 2023, concerning pericyte dysfunction in the process of ED, offering valuable insights, and suggesting directions for further research.
Pericytes/physiology* ; Humans ; Male ; Penis/innervation* ; Erectile Dysfunction/physiopathology* ; Nerve Regeneration/physiology* ; Neovascularization, Physiologic/physiology* ; Animals ; Angiogenesis