Surgical intervention combined with weight-bearing walking training promotes recovery in patients with chronic spinal cord injury: a randomized controlled study.

JOURNAL/nrgr/04.03/01300535-202412000-00032/figure1/v/2024-04-08T165401Z/r/image-tiff For patients with chronic spinal cord injury, the conventional treatment is rehabilitation and treatment of spinal cord injury complications such as urinary tract infection, pressure sores, osteoporosis, and deep vein thrombosis. Surgery is rarely performed on spinal cord injury in the chronic phase, and few treatments have been proven effective in chronic spinal cord injury patients. Development of effective therapies for chronic spinal cord injury patients is needed. We conducted a randomized controlled clinical trial in patients with chronic complete thoracic spinal cord injury to compare intensive rehabilitation (weight-bearing walking training) alone with surgical intervention plus intensive rehabilitation. This clinical trial was registered at ClinicalTrials.gov (NCT02663310). The goal of surgical intervention was spinal cord detethering, restoration of cerebrospinal fluid flow, and elimination of residual spinal cord compression. We found that surgical intervention plus weight-bearing walking training was associated with a higher incidence of American Spinal Injury Association Impairment Scale improvement, reduced spasticity, and more rapid bowel and bladder functional recovery than weight-bearing walking training alone. Overall, the surgical procedures and intensive rehabilitation were safe. American Spinal Injury Association Impairment Scale improvement was more common in T7-T11 injuries than in T2-T6 injuries. Surgery combined with rehabilitation appears to have a role in treatment of chronic spinal cord injury patients.

Comprehensive histological imaging of native microbiota in human glioma.

Mounting evidence suggests that distinct microbial communities reside in tumors and play important roles in tumor physiology. Recently, a previous study profiled the composition and localization of intratumoral bacteria using 16S ribosomal DNA (rDNA) sequencing and histological visualization methods across seven tumor types, including human glioblastoma. However, their results based on traditional histological examinations should be further validated considering potential sources of contamination originating from sample collection and processing. Here, we aim to propose a three-dimensional (3D) in situ intratumoral microbiota visualization and quantification protocol avoiding surface contamination and provide a comprehensive histological investigation on local bacteria within human glioma samples. We develop a 3D quantitative in situ intratumoral microbiota imaging strategy, combining tissue clearing, immunofluorescent labeling, optical sectioning microscopy, and image processing, to visualize bacterial lipopolysaccharide (LPS) within gliomas in a direct, contaminant-free, and unambiguous manner. Through an automated statistical algorithm, reliable signals can be distinguished for further analysis of their sizes, distribution, and fluorescence intensities. In tandem, we also combined 2D images obtained from thin-section histological methods, including immunohistochemistry and fluorescence in situ hybridization, to provide comprehensive histological imaging for local bacterial components within human glioma samples. We have, for the first time, achieved 3D quantitative imaging of bacterial LPS colonized in gliomas in a contamination-free manner within human glioma samples. We also built the multiple histological evidence chain demonstrating the irregular shapes and sparse distribution of bacterial components within human glioma samples, mostly localized near nuclear membranes or in the intercellular space. This study provides favorable evidence for the presence of microbiota in human gliomas and provides information on the feature and distribution of bacterial components. The results, along with the integrated 3D quantitative intratumoral microbiota imaging method, are promising to provide insightful information into the direct interactions between the microbial community and the host in the tumor microenvironment.

Peptide ligands targeting FGF receptors promote recovery from dorsal root crush injury via AKT/mTOR signaling.

Background: Fibroblast growth factor receptors (FGFRs) are key targets for nerve regeneration and repair. The therapeutic effect of exogenous recombinant FGFs in vivo is limited due to their high molecular weight. Small peptides with low molecular weight, easy diffusion, low immunogenicity, and nontoxic metabolite formation are potential candidates. The present study aimed to develop a novel low-molecular-weight peptide agonist of FGFR to promote nerve injury repair. Methods: Phage display technology was employed to screen peptide ligands targeting FGFR2. The peptide ligand affinity for FGFRs was detected by isothermal titration calorimetry. Structural biology-based computer virtual analysis was used to characterize the interaction between the peptide ligand and FGFR2. The peptide ligand effect on axon growth, regeneration, and behavioral recovery of sensory neurons was determined in the primary culture of sensory neurons and dorsal root ganglia (DRG) explants in vitro and a rat spinal dorsal root injury (DRI) model in vivo. The peptide ligand binding to other membrane receptors was characterized by surface plasmon resonance (SPR) and liquid chromatography-mass spectrometry (LC-MS)/MS. Intracellular signaling pathways primarily affected by the peptide ligand were characterized by phosphoproteomics, and related pathways were verified using specific inhibitors. Results: We identified a novel FGFR-targeting small peptide, CH02, with seven amino acid residues. CH02 activated FGFR signaling through high-affinity binding with the extracellular segment of FGFRs and also had an affinity for several receptor tyrosine kinase (RTK) family members, including VEGFR2. In sensory neurons cultured in vitro, CH02 maintained the survival of neurons and promoted axon growth. Simultaneously, CH02 robustly enhanced nerve regeneration and sensory-motor behavioral recovery after DRI in rats. CH02-induced activation of FGFR signaling promoted nerve regeneration primarily via AKT and ERK signaling downstream of FGFRs. Activation of mTOR downstream of AKT signaling augmented axon growth potential in response to CH02. Conclusion: Our study revealed the significant therapeutic effect of CH02 on strengthening nerve regeneration and suggested a strategy for treating peripheral and central nervous system injuries.

Human Umbilical Cord-Mesenchymal Stem Cells Survive and Migrate within the Vitreous Cavity and Ameliorate Retinal Damage in a Novel Rat Model of Chronic Glaucoma.

Glaucoma is the leading cause of irreversible blindness worldwide, and pathologically elevated intraocular pressure (IOP) is the major risk factor. Neuroprotection is one of the potential therapies for glaucomatous retinal damage. Intravitreal mesenchymal stem cell (MSC) transplantation provides a viable therapeutic option, and human umbilical cord- (hUC-) MSCs are attractive candidates for cell-based neuroprotection. Here, we investigated the ability of transplanted hUC-MSCs to survive and migrate within the vitreous cavity and their neuroprotective effects on chronic glaucomatous retina. For this, we developed a chronic ocular hypertension (COH) rat model through the intracameral injection of allogeneic Tenon's fibroblasts. Green fluorescent protein-transduced hUC-MSCs were then injected into the vitreous cavity one week after COH induction. Results showed that a moderate IOP elevation lasted for two months. Transplanted hUC-MSCs migrated toward the area of damaged retina, but did not penetrate into the retina. The hUC-MSCs survived for at least eight weeks in the vitreous cavity. Moreover, the hUC-MSCs were efficient at decreasing the loss of retinal ganglion cells; retinal damage was attenuated through the inhibition of apoptosis. In this study, we have developed a novel COH rat model and demonstrated the prolonged neuroprotective potential of intravitreal hUC-MSCs in chronic glaucoma.

Macrophage polarization induced by sustained release of 7,8-DHF from aligned PLLA fibers potentially for neural stem cell neurogenesis.

Neural stem cells (NSCs)-based regenerative medicine provides unprecedented therapeutic potential in neural insults. However, NSC-based neurogenesis is strongly influenced by the inflammatory environment after injury, which is mainly modulated by macrophages' secretion effects. In this study, we adopted poly L-lactic acid (PLLA) aligned fibers to guide macrophages elongating along the fiber directions and polarizing phenotypically toward anti-inflammatory M2 type. 7,8-DHF was loaded within the fibers with a sustained and controlled release pattern to promote the polarization of the macrophages and secretion of various anti-inflammatory factors. NSCs showed enhanced neuronal differentiation in the presence of the conditioned medium (CM) from M2 macrophages cultured on the 7,8-DHF-loaded PLLA aligned fibers. Moreover, M2-CM promoted neurogenesis by enhancing neurite outgrowth of NSC-derived neurons. In summary, we provided a novel therapeutic strategy for NSC neurogenesis by manipulating macrophage classification into anti-inflammatory M2 phenotypes with the 7,8-DHF-loaded PLLA aligned fibers, existing potential applications in treating neural injuries.

Surgical intervention combined with weight-bearing walking training improves neurological recoveries in 320 patients with clinically complete spinal cord injury: a prospective self-controlled study.

Although a large number of trials in the SCI field have been conducted, few proven gains have been realized for patients. In the present study, we determined the efficacy of a novel combination treatment involving surgical intervention and long-term weight-bearing walking training in spinal cord injury (SCI) subjects clinically diagnosed as complete or American Spinal Injury Association Impairment Scale (AIS) Class A (AIS-A). A total of 320 clinically complete SCI subjects (271 male and 49 female), aged 16-60 years, received early (≤ 7 days, n = 201) or delayed (8-30 days, n = 119) surgical interventions to reduce intraspinal or intramedullary pressure. Fifteen days post-surgery, all subjects received a weight-bearing walking training with the "Kunming Locomotion Training Program (KLTP)" for a duration of 6 months. The neurological deficit and recovery were assessed using the AIS scale and a 10-point Kunming Locomotor Scale (KLS). We found that surgical intervention significantly improved AIS scores measured at 15 days post-surgery as compared to the pre-surgery baseline scores. Significant improvement of AIS scores was detected at 3 and 6 months and the KLS further showed significant improvements between all pair-wise comparisons of time points of 15 days, 3 or 6 months indicating continued improvement in walking scores during the 6-month period. In conclusion, combining surgical intervention within 1 month post-injury and weight-bearing locomotor training promoted continued and statistically significant neurological recoveries in subjects with clinically complete SCI, which generally shows little clinical recovery within the first year after injury and most are permanently disabled. This study was approved by the Science and Research Committee of Kunming General Hospital of PLA and Kunming Tongren Hospital, China and registered at ClinicalTrials.gov (Identifier: NCT04034108) on July 26, 2019.

The Effect of Spinal Cord Injury on Beta-Amyloid Plaque Pathology in TgCRND8 Mouse Model of Alzheimer's Disease.

BACKGROUND: The accumulation and aggregation of Aß as amyloid plaques, the hallmark pathology of the Alzheimer's disease, has been found in other neurological disorders, such as traumatic brain injury. The axonal injury may contribute to the formation of Aß plaques. Studies to date have focused on the brain, with no investigations of spinal cord, although brain and cord share the same cellular components. OBJECTIVE: We utilized a spinal cord transection model to examine whether spinal cord injury acutely induced the onset or promote the progression of Aß plaque 3 days after injury in TgCRND8 transgenic model of AD. METHODS: Spinal cord transection was performed in TgCRND8 mice and its littermate control wild type mice at the age of 3 and 20 months. Immunohistochemical reactions/ELISA assay were used to determine the extent of axonal damage and occurrence/alteration of Aß plaques or levels of Aß at different ages in the spinal cord of TgCRND8 mice. RESULTS: After injury, widespread axonal pathology indicated by intra-axonal co-accumulations of APP and its product, Aß, was observed in perilesional region of the spinal cord in the TgCRND8 mice at the age of 3 and 20 months, as compared to age-matched non-TgCRND8 mice. However, no Aß plaques were found in the TgCRND8 mice at the age of 3 months. The 20-month-old TgCRND8 mice with established amyloidosis in spinal cord had a reduction rather than increase in plaque burden at the lesion site compared to the tissue adjacent to the injured area and corresponding area in sham mice following spinal cord transection. The lesion site of spinal cord area was occupied by CD68 positive macrophages/ activated microglia in injured mice compared to sham animals. These results indicate that spinal cord injury does not induce the acute onset and progression of Aß plaque deposition in the spinal cord of TgCRND8 mice. Conversely, it induces the regression of Aß plaque deposition in TgCRND8 mice. CONCLUSION: The findings underscore the dependence of traumatic axonal injury in governing acute Aß plaque formation and provide evidence that Aß plaque pathology may not play a role in secondary injury cascades following spinal cord injury.

Engineering Microenvironment for Endogenous Neural Regeneration after Spinal Cord Injury by Reassembling Extracellular Matrix.

The formation of a fluid-filled cystic cavity after spinal cord injury (SCI) is a major obstacle for neural regeneration. In this study, the post-SCI cavity was bridged by a functional self-assembling peptide (F-SAP) nanofiber hydrogel coupled with growth factor "cocktail". A sustained release of growth factors was achieved by carefully tailoring the physical hindrances and charge-induced interactions between the growth factors and the peptide nanofibers. Such an engineering microenvironment elicited axon regeneration, as determined by tracing of the descending pathway in the dorsal columns and immunochemical detection of regenerating axons beyond the lesion. Furthermore, the dynamic spatiotemporal activation line of endogenous NSCs (eNSCs) after severe SCI was thoroughly investigated. The results indicated that the growth factor-coupled F-SAP greatly facilitated eNSC proliferation, neuronal differentiation, maturation, myelination, and more importantly, the formation of interconnection with severed descending corticospinal tracts. The robust endogenous neurogenesis essentially led to the recovery of locomotion and electrophysiological properties. In conclusion, the growth factor-coupled F-SAP nanofiber hydrogel elucidated the therapeutic effect of eliciting endogenous neurogenesis by locally reassembling an extracellular matrix.

Microvascular endothelial cells engulf myelin debris and promote macrophage recruitment and fibrosis after neural injury.

The clearance of damaged myelin sheaths is critical to ensure functional recovery from neural injury. Here we show a previously unidentified role for microvessels and their lining endothelial cells in engulfing myelin debris in spinal cord injury (SCI) and experimental autoimmune encephalomyelitis (EAE). We demonstrate that IgG opsonization of myelin debris is required for its effective engulfment by endothelial cells and that the autophagy-lysosome pathway is crucial for degradation of engulfed myelin debris. We further show that endothelial cells exert critical functions beyond myelin clearance to promote progression of demyelination disorders by regulating macrophage infiltration, pathologic angiogenesis and fibrosis in both SCI and EAE. Unexpectedly, myelin debris engulfment induces endothelial-to-mesenchymal transition, a process that confers upon endothelial cells the ability to stimulate the endothelial-derived production of fibrotic components. Overall, our study demonstrates that the processing of myelin debris through the autophagy-lysosome pathway promotes inflammation and angiogenesis and may contribute to fibrotic scar formation.

Sphingosine 1-phosphate stimulates eyelid closure in the developing rat by stimulating EGFR signaling.

In many mammals, the eyelids migrate over the eye and fuse during embryogenesis to protect the cornea from damage during birth and early life. Loss-of-function mutations affecting the epidermal growth factor receptor (EGFR) signaling pathway cause an eyes-open-at-birth (EOB) phenotype in rodents. We identified an insertional mutation in Spinster homolog 2 (Spns2) in a strain of transgenic rats exhibiting the EOB phenotype. Spns2, a sphingosine 1-phosphate (S1P) transporter that releases S1P from cells, was enriched at the tip of developing eyelids in wild-type rat embryos. Spns2 expression or treatment with S1P or any one of several EGFR ligands rescued the EOB Spns2 mutant phenotype in vivo and in tissue explants in vitro and rescued the formation of stress fibers in primary keratinocytes from mutants. S1P signaled through the receptors S1PR1, S1PR2, and S1PR3 to activate extracellular signal-regulated kinase (ERK) and EGFR-dependent mitogen-activated protein kinase kinase kinase 1 (MEKK1)-c-Jun signaling. S1P also induced the nuclear translocation of the transcription factor MAL in a manner dependent on EGFR signaling. MAL and c-Jun stimulated the expression of the microRNAs miR-21 and miR-222, both of which target the metalloprotease inhibitor TIMP3, thus promoting metalloprotease activity. The metalloproteases ADAM10 and ADAM17 stimulated EGFR signaling by cleaving a membrane-anchored form of EGF to release the ligand. Our results outline a network by which S1P transactivates EGFR signaling through a complex mechanism involving feedback between several intra- and extracellular molecules to promote eyelid fusion in the developing rat.

MiR-137-3p rescue motoneuron death by targeting calpain-2.

Brachial plexus root avulsion (BPRA) is a type of injury that leads to motor function loss as a result of motoneurons (MNs) degeneration. Here we identified that the reduced expression of rat miR-137-3p in the ventral horn of spinal cord was associated with MNs death. However, the pathophysiological role of miR-137-3p in root avulsion remains poorly understood. We demonstrated that the calcium-activated neutral protease-2 (calpain-2) was a direct target gene of miR-137-3p with miR-137-3p binding to the 3'-untranslated region of calpain-2. Silencing of calpain-2 suppressed the expression of neuronal nitric oxide synthase (nNOS), a primary source of nitric oxide (NO). After avulsion 2 weeks, up-regulation of miR-137-3p in the spinal cord reduced calpain-2 levels and nNOS expression inside spinal MNs, resulting in an amelioration of the MNs death. These events provide new insight into the mechanism by which upregulation of miR-137-3p can impair MN survival in the BPRA.

Combination Treatment With Exogenous GDNF and Fetal Spinal Cord Cells Results in Better Motoneuron Survival and Functional Recovery After Avulsion Injury With Delayed Root Reimplantation.

When spinal roots are torn off from the spinal cord, both the peripheral and central nervous system get damaged. As the motoneurons lose their axons, they start to die rapidly, whereas target muscles atrophy due to the denervation. In this kind of complicated injury, different processes need to be targeted in the search for the best treatment strategy. In this study, we tested glial cell-derived neurotrophic factor (GDNF) treatment and fetal lumbar cell transplantation for their effectiveness to prevent motoneuron death and muscle atrophy after the spinal root avulsion and delayed reimplantation. Application of exogenous GDNF to injured spinal cord greatly prevented the motoneuron death and enhanced the regeneration and axonal sprouting, whereas no effect was seen on the functional recovery. In contrast, cell transplantation into the distal nerve did not affect the host motoneurons but instead mitigated the muscle atrophy. The combination of GDNF and cell graft reunited the positive effects resulting in better functional recovery and could therefore be considered as a promising strategy for nerve and spinal cord injuries that involve the avulsion of spinal roots.

Transplantation of Embryonic Spinal Cord Derived Cells Helps to Prevent Muscle Atrophy after Peripheral Nerve Injury.

Injuries to peripheral nerves are frequent in serious traumas and spinal cord injuries. In addition to surgical approaches, other interventions, such as cell transplantation, should be considered to keep the muscles in good condition until the axons regenerate. In this study, E14.5 rat embryonic spinal cord fetal cells and cultured neural progenitor cells from different spinal cord segments were injected into transected musculocutaneous nerve of 200-300 g female Sprague Dawley (SD) rats, and atrophy in biceps brachii was assessed. Both kinds of cells were able to survive, extend their axons towards the muscle and form neuromuscular junctions that were functional in electromyographic studies. As a result, muscle endplates were preserved and atrophy was reduced. Furthermore, we observed that the fetal cells had a better effect in reducing the muscle atrophy compared to the pure neural progenitor cells, whereas lumbar cells were more beneficial compared to thoracic and cervical cells. In addition, fetal lumbar cells were used to supplement six weeks delayed surgical repair after the nerve transection. Cell transplantation helped to preserve the muscle endplates, which in turn lead to earlier functional recovery seen in behavioral test and electromyography. In conclusion, we were able to show that embryonic spinal cord derived cells, especially the lumbar fetal cells, are beneficial in the treatment of peripheral nerve injuries due to their ability to prevent the muscle atrophy.

Tissue engineering with peripheral blood-derived mesenchymal stem cells promotes the regeneration of injured peripheral nerves.

Peripheral nerve injury repair can be enhanced by Schwann cell (SC) transplantation, but clinical applications are limited by the lack of a cell source. Thus, alternative systems for generating SCs are desired. Herein, we found the peripheral blood-derived mesenchymal stem cells (PBMSCs) could be induced into SC like cells with expressing SC-specific markers (S100, P75NTR and CNPase) and functional factors (NGF, NT-3, c-Fos, and Krox20). When the induced PBMSCs (iPBMSCs) were transplanted into crushed rat sciatic nerves, they functioned as SCs by wrapping the injured axons and expressing myelin specific marker of MBP. Furthermore, iPBMSCs seeded in an artificial nerve conduit to bridge a 10-mm defect in a sciatic nerve achieved significant nerve regeneration outcomes, including axonal regeneration and remyelination, nerve conduction recovery, and restoration of motor function, and attenuated myoatrophy and neuromuscular junction degeneration in the target muscle. Overall, the data from this study indicated that PBMSCs can transdifferentiate towards SC-like cells and have potential as grafting cells for nerve tissue engineering.

Transplantation of embryonic spinal cord neurons to the injured distal nerve promotes axonal regeneration after delayed nerve repair.

Peripheral nerve injury (PNI) usually results in poor functional recovery. Nerve repair is the common clinical treatment for PNI but is always obstructed by the chronic degeneration of the distal stump and muscle. Cell transplantation can alleviate the muscle atrophy after PNI, but the subsequent recovery of the locomotive function is seldom described. In this study, we combined cell transplantation and nerve repair to investigate whether the transplantation of embryonic spinal cord cells could benefit the delayed nerve repair. The experiment consisted of 3 stages: transection of the tibial nerve to induce 'pre-degeneration', a second surgery performed 2 weeks later for transplantation of E14 embryonic spinal cord cells or vehicle (culture medium) at the distal end of the injured nerve, and, 3 months later, the removal of the grafted cells and the cross-suturing of the residual distal end to the proximal end of a freshly cut ipsilateral common peroneal (CP) nerve. Cell survival and fate after the transplantation were investigated, and the functional recovery after the cross-suturing was compared between the groups. The grafted cells could survive and generate motor neurons, extending axons that were subsequently myelinated and forming synapses with the muscle. After the cross-suturing, the axonal regeneration from the proximal stump of the injured CP nerve and the functional recovery of the denervated gastrocnemius muscle were significantly promoted in the group receiving the cells. Our study presents a new perspective indicating that the transplantation of embryonic spinal cord neurons may be a valuable therapeutic strategy for PNI.

Self-assembly behaviors of molecular designer functional RADA16-I peptides: influence of motifs, pH, and assembly time.

In the current study, we present three designer self-assembling peptides (SAPs) by appending RADA 16-I with epitopes IKVAV, RGD, and YIGSR, which have different net charges and amphiphilic properties at neutral pH. The self-assembly of the designer SAPs is intensively investigated as a function of pH, canion type, and assembly time. The morphologies of the designer SAPs were studied by atomic force microscope. The secondary structure was investigated by circular dichroism. The dynamic viscoelasticity of designer SAP solutions was examined during titration with different alkaline reagents. Our study indicated that both electrostatic and hydrophilic/hydrophobic interactions of the motifs exhibited influences on the self-assembly, consequentially affecting the fiber morphologies and rheological properties. Moreover, NaOH induced a quicker assembly/reassembly of the designer SAPs than Tris because of its strong ionic strength. Therefore, our study gained comprehensive insight into the self-assembling mechanism as references for developing RADA 16-I-based functional SAPs.

Neuroprotective Effects of Methyl 3,4-Dihydroxybenzoate against TBHP-Induced Oxidative Damage in SH-SY5Y Cells.

This study investigated the neuroprotective effects of methyl 3,4-dihydroxybenzoate (MDHB) against t-butyl hydroperoxide (TBHP) induced oxidative damage in SH-SY5Y (human neuroblastoma cells) and the underlying mechanisms. SH-SY5Y were cultured in DMEM + 10% FBS for 24 h and pretreated with different concentrations of MDHB or N-acetyl-l-cysteine (NAC) for 4 h prior to the addition of 40 µM TBHP for 24 h. Cell viability was analyzed using the methylthiazolyltetrazolium (MTT) and lactate dehydrogenase (LDH) assays. An annexin V-FITC assay was used to detect cell apoptosis rates. The 2',7'-dichlorofluorescin diacetate (DCFH-DA) assay was used to determine intracellular ROS levels. The activities of antioxidative enzymes (GSH-Px and SOD) were measured using commercially available kits. The oxidative DNA damage marker 8-OHdG was detected using ELISA. Western blotting was used to determine the expression of Bcl-2, Bax, caspase 3, p-Akt and Akt proteins in treated SH-SY5Y cells. Our results showed that MDHB is an effective neuroprotective compound that can mitigate oxidative stress and inhibit apoptosis in SH-SY5Y cells.

Mechanistic study of TRPM2-Ca(2+)-CAMK2-BECN1 signaling in oxidative stress-induced autophagy inhibition.

Reactive oxygen species (ROS) have been commonly accepted as inducers of autophagy, and autophagy in turn is activated to relieve oxidative stress. Yet, whether and how oxidative stress, generated in various human pathologies, regulates autophagy remains unknown. Here, we mechanistically studied the role of TRPM2 (transient receptor potential cation channel subfamily M member 2)-mediated Ca(2+) influx in oxidative stress-mediated autophagy regulation. On the one hand, we demonstrated that oxidative stress triggered TRPM2-dependent Ca(2+) influx to inhibit the induction of early autophagy, which renders cells more susceptible to death. On the other hand, oxidative stress induced autophagy (and not cell death) in the absence of the TRPM2-mediated Ca(2+) influx. Moreover, in response to oxidative stress, TRPM2-mediated Ca(2+) influx activated CAMK2 (calcium/calmodulin dependent protein kinase II) at levels of both phosphorylation and oxidation, and the activated CAMK2 subsequently phosphorylated BECN1/Beclin 1 on Ser295. Ser295 phosphorylation of BECN1 in turn decreased the association between BECN1 and PIK3C3/VPS34, but induced binding between BECN1 and BCL2. Clinically, acetaminophen (APAP) overdose is the most common cause of acute liver failure worldwide. We demonstrated that APAP overdose also activated ROS-TRPM2-CAMK2-BECN1 signaling to suppress autophagy, thereby causing primary hepatocytes to be more vulnerable to death. Inhibiting the TRPM2-Ca(2+)-CAMK2 cascade significantly mitigated APAP-induced liver injury. In summary, our data clearly demonstrate that oxidative stress activates the TRPM2-Ca(2+)-CAMK2 cascade to phosphorylate BECN1 resulting in autophagy inhibition.

Lithium accelerates functional motor recovery by improving remyelination of regenerating axons following ventral root avulsion and reimplantation.

Brachial plexus injury (BPI) often involves the complete or partial avulsion of one or more of the cervical nerve roots, which leads to permanent paralysis of the innervated muscles. Reimplantation surgery has been attempted as a clinical treatment for brachial plexus root avulsion but has failed to achieve complete functional recovery. Lithium is a mood stabilizer drug that is used to treat bipolar disorder; however, its effects on spinal cord or peripheral nerve injuries have also been reported. The purpose of this study was to investigate whether lithium can improve functional motor recovery after ventral root avulsion and reimplantation in a rat model of BPI. The results showed that systemic treatment with a clinical dose of lithium promoted motor neuron outgrowth and increased the efficiency of motor unit regeneration through enhanced remyelination. An analysis of myelin-associated genes showed that the effects of lithium started during the early phase of remyelination and persisted through the late stage of the process. Efficient remyelination of the regenerated axons in the lithium-treated rats led to an earlier functional recovery. Therefore, we demonstrated that lithium might be a potential clinical treatment for BPI in combination with reimplantation surgery.

Cell Transplantation and Neuroengineering Approach for Spinal Cord Injury Treatment: A Summary of Current Laboratory Findings and Review of Literature.

Spinal cord injury (SCI) can cause severe traumatic injury to the central nervous system (CNS). Current therapeutic effects achieved for SCI in clinical medicine show that there is still a long way to go to reach the desired goal of full or significant functional recovery. In basic medical research, however, cell transplantation, gene therapy, application of cytokines, and biomaterial scaffolds have been widely used and investigated as treatments for SCI. All of these strategies when used separately would help rebuild, to some extent, the neural circuits in the lesion area of the spinal cord. In light of this, it is generally accepted that a combined treatment may be a more effective strategy. This review focuses primarily on our recent series of work on transplantation of Schwann cells and adult stem cells, and transplantation of stem cell-derived neural network scaffolds with functional synapses. Arising from this, an artificial neural network (an exogenous neuronal relay) has been designed and fabricated by us-a biomaterial scaffold implanted with Schwann cells modified by the neurotrophin-3 (NT-3) gene and adult stem cells modified with the TrkC (receptor of NT-3) gene. More importantly, experimental evidence suggests that the novel artificial network can integrate with the host tissue and serve as an exogenous neuronal relay for signal transfer and functional improvement of SCI.