AAV2-mediated and hypoxia response element-directed expression of bFGF in neural stem cells showed therapeutic effects on spinal cord injury in rats

Irisflorentin improves functional recovery after spinal cord injury by protecting the blood-spinal cord barrier and promoting axonal growth

Spinal cord injury (SCI) induces the disruption of the blood-spinal cord barrier (BSCB) and the failure of axonal growth. SCI activates a complex series of responses, including cell apoptosis and endoplasmic reticulum (ER) stress. Pericytes play a critical role in maintaining BSCB integrity and facilitating tissue growth and repair. However, the roles of pericytes in SCI and the potential mechanisms underlying the improvements in functional recovery in SCI remain unclear. Recent evidence indicates that irisflorentin exerts neuroprotective effects against Parkinson's disease; however, whether it has potential protective roles in SCI or not is still unknown. In this study, we found that the administration of irisflorentin significantly inhibited pericyte apoptosis, protected BSCB integrity, promoted axonal growth, and ultimately improved locomotion recovery in a rat model of SCI. In vitro, we found that the positive effects of irisflorentin on axonal growth were likely to be mediated by regulating the crosstalk between pericytes and neurons. Furthermore, irisflorentin effectively ameliorated ER stress caused by incubation with thapsigargin (TG) in pericytes. Meanwhile, the protective effect of irisflorentin on BSCB disruption is strongly related to the reduction of pericyte apoptosis via inhibition of ER stress. Collectively, our findings demonstrate that irisflorentin is beneficial for functional recovery after SCI and that pericytes are a valid target of interest for future SCI therapies.

Low frequency of repetitive trans-spinal magnetic stimulation promotes functional recovery after spinal cord injury in mice through inhibiting TGF-β1/Smad2/3 signaling pathway

Spinal cord injury (SCI) remains a worldwide challenge due to limited treatment strategies. Repetitive trans-spinal magnetic stimulation (rTSMS) is among the most cutting-edge treatments for SCI. However, the mechanism underlying rTSMS on functional recovery is still unclear. In this study, 8-week-old C57BL/6J female mice were used to design SCI models followed by treatment with monotherapy (1 Hz rTSMS or LY364947) or combination therapy (rTSMS + LY364947). Our results showed obvious functional recovery after monotherapies compared to untreated mice. Immunofluorescence results demonstrated that rTSMS and LY364947 modulate the lesion scar by decreasing fibrosis and GFAP and possess the effect on neural protection. In addition, rTSMS suppressed inflammation and the activation of TGFβ1/Smad2/3 signaling pathway, as evidenced by markedly reduced TGF-βRⅠ, Smad2/3, and p-Smad2/3 compared with untreated mice. Overall, it was confirmed that 1 Hz rTSMS promotes SCI recovery by suppressing the TGFβ1/Smad2/3 signaling, revealing a novel pathological mechanism of 1 Hz rTSMS intervention, and may provide potential targets for clinical treatment.

Electromagnetic Cellularized Patch with Wirelessly Electrical Stimulation for Promoting Neuronal Differentiation and Spinal Cord Injury Repair

Although stem cell therapy holds promise for the treatment of spinal cord injury (SCI), its practical applications are limited by the low degree of neural differentiation. Electrical stimulation is one of the most effective ways to promote the differentiation of stem cells into neurons, but conventional wired electrical stimulation may cause secondary injuries, inflammation, pain, and infection. Here, based on the high conductivity of graphite and the electromagnetic induction effect, graphite nanosheets with neural stem cells (NSCs) are proposed as an electromagnetic cellularized patch to generate in situ wirelessly pulsed electric signals under a rotating magnetic field for regulating neuronal differentiation of NSCs to treat SCI. The strength and frequency of the induced voltage can be controlled by adjusting the rotation speed of the magnetic field. The generated pulsed electrical signals promote the differentiation of NSCs into functional mature neurons and increase the proportion of neurons from 12.5% to 33.7%. When implanted in the subarachnoid region of the injured spinal cord, the electromagnetic cellularized patch improves the behavioral performance of the hind limbs and the repair of spinal cord tissue in SCI mice. This work opens a new avenue for remote treatment of SCI and other nervous system diseases.

Targeted Repair of Spinal Cord Injury Based on miRNA-124-3p-Loaded Mesoporous Silica Camouflaged by Stem Cell Membrane Modified with Rabies Virus Glycoprotein

Spinal cord injury (SCI) has no effective treatment modalities. It faces a significant global therapeutical challenge, given its features of poor axon regeneration, progressive local inflammation, and inefficient systemic drug delivery due to the blood-spinal cord barrier (BSCB). To address these challenges, a new nano complex that achieves targeted drug delivery to the damaged spinal cord is proposed, which contains a mesoporous silica nanoparticle core loaded with microRNA and a cloaking layer of human umbilical cord mesenchymal stem cell membrane modified with rabies virus glycoprotein (RVG). The nano complex more readily crosses the damaged BSCB with its exosome-resembling properties, including appropriate size and a low-immunogenic cell membrane disguise and accumulates in the injury center because of RVG, where it releases abundant microRNAs to elicit axon sprouting and rehabilitate the inflammatory microenvironment. Culturing with nano complexes promotes axonal growth in neurons and M2 polarization in microglia. Furthermore, it showed that SCI mice treated with this nano complex by tail vein injection display significant improvement in axon regrowth, microenvironment regulation, and functional restoration. The efficacy and biocompatibility of the targeted delivery of microRNA by nano complexes demonstrate their immense potential as a noninvasive treatment for SCI.

The beneficial effect of α-lipoic acid on spinal cord injury repair in rats is mediated through inhibition of oxidative stress: A transcriptomic analysis

BACKGROUND

Oxidative stress is a crucial factor contributing to the occurrence and development of secondary damage in spinal cord injuries (SCI), ultimately impacting the recovery process. α-lipoic acid (ALA) exhibits potent antioxidant properties, effectively reducing secondary damage and providing neuroprotective benefits. However, the precise mechanism by which ALA plays its antioxidant role remains unknown.

METHODS

We established a model of moderate spinal cord contusion in rats. Experimental rats were randomly divided into 3 distinct groups: the sham group, the model control group (SCI_Veh), and the ALA treatment group (SCI_ALA). The sham group rats were exposed only to the SC without contusion injury. Rats belonging to SCI_Veh group were not administered any treatment after SCI. Rats of SCI_ALA group were intraperitoneally injected with the corresponding volume of ALA according to body weight for three consecutive days after the surgery. Subsequently, three days after SCI, spinal cord samples were obtained from three groups of rats: the sham group, model control group, and administration group. Thereafter, total RNA was extracted from the samples and the expression of three sets of differential genes was analyzed by transcriptome sequencing technology. Real-time PCR was used to verify the sequencing results. The impact of ALA on oxidative stress in rats following SCI was assessed by measuring their total antioxidant capacity and hydrogen peroxide (H2O2) content. The effects of ALA on rat recovery following SCI was investigated through Beattie and Bresnahan (BBB) score and footprint analysis.

RESULTS

The findings from the transcriptome sequencing analysis revealed that the model control group had 2975 genes with altered expression levels when compared to the ALA treatment group. Among these genes, 1583 were found to be upregulated while 1392 were down-regulated. Gene ontology (GO) displayed significant enrichment in terms of functionality, specifically in oxidative phosphorylation, oxidoreductase activity, and signaling receptor activity. The Kyoto encyclopedia of genes and genomes (KEGG) pathway was enriched in oxidative phosphorylation, glutathione metabolism and cell cycle. ALA was found to have multiple benefits for rats after SCI, including increasing their antioxidant capacity and reducing H2O2 levels. Additionally, it was effective in improving motor function (such as 7 days after SCI, the BBB score for SCI_ALA was 8.400 ± 0.937 compared to 7.050 ± 1.141 for SCI_Veh) and promoting histological recovery after SCI (The results of HE demonstrated that the percentage of damage area in was 44.002 ± 6.680 in the SCI_ALA and 57.215 ± 3.964 in the SCI_Veh at the center of injury.). The sequence data from this study has been deposited into Sequence Read Archive (https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE242507).

CONCLUSION

Overall, the findings of this study confirmed the beneficial effects of ALA on recovery in SCI rats through transcriptome sequencing, behavioral, as well histology analyses.

Extracellular Vesicles Derived from Glioma Stem Cells Affect Glycometabolic Reprogramming of Glioma Cells Through the miR-10b-5p/PTEN/PI3K/Akt Pathway

OBJECTIVE

Glioma is one of the most prevalently diagnosed types of primary malignant brain tumors. Glioma stem cells (GSCs) are crucial in glioma recurrence. This study aims to elucidate the mechanism by which extracellular vehicles (EVs) derived from GSCs modulate glycometabolic reprogramming in glioma.

METHODS

Xenograft mouse models and cell models of glioma were established and treated with GSC-EVs. Additionally, levels and activities of PFK1, LDHA, and FASN were assessed to evaluate the effect of GSC-EVs on glycometabolic reprogramming in glioma. Glioma cell proliferation, invasion, and migration were evaluated using MTT, EdU, Colony formation, and Transwell assays. miR-10b-5p expression was determined, with its target gene PTEN and downstream pathway PI3K/Akt evaluated. The involvement of miR-10b-5p and the PI3K/Akt pathway in the effect of GSC-EVs on glycometabolic reprogramming was tested through joint experiments.

RESULTS

GSC-EVs facilitated glycometabolic reprogramming in glioma mice, along with enhancing glucose uptake, lactate level, and adenosine monophosphate-to-adenosine triphosphate ratio. Moreover, GSC-EV treatment potentiated glioma cell proliferation, invasion, and migration, reinforced cell resistance to temozolomide, and raised levels and activities of PFK1, LDHA, and FASN. miR-10b-5p was highly-expressed in GSC-EV-treated glioma cells while being carried into glioma cells by GSC-EVs. miR-10b-5p targeted PTEN and activated the PI3K/Akt pathway, hence stimulating glycometabolic reprogramming.

CONCLUSION

GSC-EVs target PTEN and activate the PI3K/Akt pathway through carrying miR-10b-5p, subsequently accelerating glycometabolic reprogramming in glioma, which might provide new insights into glioma treatment.

Fabrication of multifunctional silk nanofibril/hyaluronic acid scaffold for spinal cord repair

Bioactive scaffolds accurately mimicking the structure and composition of the extracellular matrix have garnered significant interest in tissue engineering. In this study, we developed a platform utilizing natural silk nanofibrils, hyaluronic acid, and basic fibroblast growth factor for the purpose of promoting spinal cord regeneration by creating an optimal microenvironment. The bioactive scaffold exhibited notable characteristics such as high porosity and hydrophilicity, attributed to its unique nanostructure, high connectivity, and polysaccharide composition. Furthermore, the pore size of the scaffold can be adjusted within the range of 90 μm to 120 μm by varying the content of hyaluronic acid. In vitro, human umbilical vein endothelial cells were seeded into the scaffold, demonstrating enhanced cell viability. The scaffold facilitated cell proliferation and migration. In vivo experiments on rats indicated that the scaffold had a beneficial impact on spinal cord regeneration, creating a conducive environment for motor function recovery of the rats. This effect may be attributed to the scaffold's ability to stimulate axon growth and neuronal survival, as well as inhibit the formation of glial scars, as evidenced by the decreased expression of growth associated protein-43, microtubule-associated protein 2, and neurofilament-200. This study presents a promising method to develop a feasible bioscaffold for the treatment of spinal cord injury.

Fisetin orchestrates neuroinflammation resolution and facilitates spinal cord injury recovery through enhanced autophagy in pro-inflammatory glial cells

BACKGROUND

Neuroinflammation, a critical component of the secondary injury cascade post-spinal cord injury, involves the activation of pro-inflammatory cells and release of inflammatory mediators. Resolution of neuroinflammation is closely linked to cellular autophagy. This study investigates the potential of Fisetin, a natural anti-inflammatory compound, to ameliorate neuroinflammation and confer spinal cord injury protection through the regulation of autophagy in pro-inflammatory cells.

METHODS

Utilizing a rat T10 spinal cord injury model with distinct treatment groups (Sham, Fisetin-treated, and Fisetin combined with autophagy inhibitor), alongside in vitro models involving lipopolysaccharide (LPS)-stimulated microglial cell activation and co-culture with neurons, we employed techniques such as transcriptomic sequencing, histological assessments (immunofluorescence staining, etc.), molecular analyses (PCR, WB, ELISA, etc.), and behavioral evaluations to discern differences in neuroinflammation, autophagy, neuronal apoptosis, and neurological function recovery.

RESULTS

Fisetin significantly augmented autophagic activity in injured spinal cord tissue, crucially contributing to neurological function recovery in spinal cord-injured rats. Fisetin's autophagy-dependent effects were associated with a reduction in neuronal apoptosis at the injury site. The treatment reduced the population of CD68+ and iNOS+ cells, coupled with decreased pro-inflammatory cytokines IL-6 and TNF-α levels, through autophagy-dependent pathways. Fisetin pre-treatment attenuated LPS-induced pro-inflammatory polarization of microglial cells, with this protective effect partially blocked by autophagy inhibition. Fisetin-induced autophagy in the injured spinal cord and pro-inflammatory microglial cells was associated with significant activation of AMPK and inhibition of mTOR.

CONCLUSION

Fisetin orchestrates enhanced autophagy in pro-inflammatory microglial cells through the AMPK-mTOR signaling pathway, thereby mitigating neuroinflammation and reducing the apoptotic effects of neuroinflammation on neurons. This mechanistic insight significantly contributes to the protection and recovery of neurological function following spinal cord injury, underscoring the vital nature of Fisetin as a potential therapeutic agent.

Bone Marrow Mesenchymal Stem Cell-Derived Exosomes Promote the Recovery of Spinal Cord Injury and Inhibit Ferroptosis by Inactivating IL-17 Pathway

Mesenchymal stem cell (MSC)-derived exosomes are considered as alternative to cell therapy in various diseases. This study aimed to understand the effect of bone marrow MSC-derived exosomes (BMMSC-exos) on spinal cord injury (SCI) and to unveil its regulatory mechanism on ferroptosis. Exosomes were isolated from BMMSCs and the uptake of BMMSCs-exos by PC12 cells was determined using PKH67 staining. The effect of BMMSC-exos on SCI in rats was studied by evaluating pathological changes of spinal cord tissues, inflammatory cytokines, and ferroptosis-related proteins. Transcriptome sequencing was used to discover the differential expressed genes (DEGs) between SCI rats and BMMSC-exos-treated rats followed by functional enrichment analyses. The effect of BMMSC-exos on ferroptosis and interleukin 17 (IL-17) pathway was evaluated in SCI rats and oxygen-glucose deprivation (OGD)-treated PC12 cells. The results showed that particles extracted from BMMSCs were exosomes that could be taken up by PC12 cells. BMMSC-exos treatment ameliorated injuries of spinal cord, suppressed the accumulation of Fe2+, malondialdehyde (MDA), and reactive oxygen species (ROS), with the elevated glutathione (GSH). Also, BMMSC-exos downregulated the expression of acyl-CoA synthetase long chain family member 4 (ACSL4) and upregulated glutathione peroxidase 4 (GPX4) and cysteine/glutamate antiporter xCT. A total of 110 DEGs were discovered and they were mainly enriched in IL-17 signaling pathway. Further in vitro and in vivo experiments showed that BMMSC-exos inactivated IL-17 pathway. BMMSC-exos promote the recovery of SCI and inhibit ferroptosis by inhibiting the IL-17 pathway, which provides BMMSC-exos as an alternative to the management of SCI.

The TGFβ1/SMADs/Snail1 signaling axis mediates pericyte-derived fibrous scar formation after spinal cord injury

AIMS

The deposition of fibrous scars after spinal cord injury (SCI) affects axon regeneration and the recovery of sensorimotor function. It has been reported that microvascular pericytes in the neurovascular unit are the main source of myofibroblasts after SCI, but the specific molecular targets that regulate pericyte participation in the formation of fibrous scars remain to be clarified.

METHODS

In this study, a rat model of spinal cord dorsal hemisection injury was used. After SCI, epigallocatechin gallate (EGCG) was intraperitoneally injected to block the TGFβ1 signaling pathway or LV-Snail1-shRNA was immediately injected near the core of the injury using a microsyringe to silence Snail1 expression. Western blotting and RT-qPCR were used to analyze protein expression and transcription levels in tissues. Nissl staining and immunofluorescence analysis were used to analyze neuronal cell viability, scar tissue, and axon regeneration after SCI. Finally, the recovery of hind limb function after SCI was evaluated.

RESULTS

The results showed that targeted inhibition of Snail1 could block TGFβ1-induced pericyte-myofibroblast differentiation in vitro. In vivo experiments showed that timely blockade of Snail1 could reduce fibrous scar deposition after SCI, promote axon regeneration, improve neuronal survival, and facilitate the recovery of lower limb motor function.

CONCLUSION

In summary, Snail1 promotes the deposition of fibrous scars and inhibits axonal regeneration after SCI by inducing the differentiation of pericytes into myofibroblasts. Snail1 may be a promising therapeutic target for SCI.

Asiaticoside Attenuates Blood-Spinal Cord Barrier Disruption by Inhibiting Endoplasmic Reticulum Stress in Pericytes After Spinal Cord Injury

The blood-spinal cord barrier (BSCB) plays a vital role in the recovery of spinal cord function after spinal cord injury (SCI). Pericytes, pluripotent members of the neurovascular unit (NVU), receive signals from neighboring cells and are critical for maintaining CNS function. Therapeutic targets for the BSCB include endothelial cells (ECs) and glial cells, but few drugs target pericytes. This study was designed to explore whether asiaticoside has a positively effect on pericytes and the integrity of the BSCB. In this study, we found that asiaticoside could inhibit the loss of junction proteins just 1 day after SCI in vivo, but our in vitro study showed no significant differences in the expression of endothelial junction proteins between the control and asiaticoside treatment groups. We also found that asiaticoside could inhibit endoplasmic reticulum (ER) stress and pericyte apoptosis, which might be associated with the inhibition of junction protein reduction in ECs. Thus, we investigated the interactions between pericytes and ECs. Our results showed that asiaticoside could decrease the release of matrix metalloproteinase (MMP)-9 in pericytes and therefore upregulate the expression of junction proteins in ECs. Furthermore, the protective effect of asiaticoside on pericytes is related to the inhibition of ER stress via the MAPK signaling pathway. Taken together, our results demonstrate that asiaticoside treatment inhibits BSCB disruption and enhances functional recovery after SCI.

FGF-18 Protects the Injured Spinal cord in mice by Suppressing Pyroptosis and Promoting Autophagy via the AKT-mTOR-TRPML1 axis

Spinal cord injury (SCI) is a severe medical condition with lasting effects. The efficacy of numerous clinical treatments is hampered by the intricate pathophysiological mechanism of SCI. Fibroblast growth factor 18 (FGF-18) has been found to exert neuroprotective effects after brain ischaemia, but its effect after SCI has not been well explored. The aim of the present study was to explore the therapeutic effect of FGF-18 on SCI and the related mechanism. In the present study, a mouse model of SCI was used, and the results showed that FGF-18 may significantly affect functional recovery. The present findings demonstrated that FGF-18 directly promoted functional recovery by increasing autophagy and decreasing pyroptosis. In addition, FGF-18 increased autophagy, and the well-known autophagy inhibitor 3-methyladenine (3MA) reversed the therapeutic benefits of FGF-18 after SCI, suggesting that autophagy mediates the therapeutic effects of FGF-18 on SCI. A mechanistic study revealed that after stimulation of the protein kinase B (AKT)-transient receptor potential mucolipin 1 (TRPML1)-calcineurin signalling pathway, the FGF-18-induced increase in autophagy was mediated by the dephosphorylation and nuclear translocation of transcription factor E3 (TFE3). Together, these findings indicated that FGF-18 is a robust autophagy modulator capable of accelerating functional recovery after SCI, suggesting that it may be a promising treatment for SCI in the clinic.

Fibroblast growth factor 5 protects against spinal cord injury through activating AMPK pathway

Excessive productions of inflammatory cytokines and free radicals are involved in spinal cord injury (SCI). Fibroblast growth factor 5 (FGF5) is associated with inflammatory response and oxidative damage, and we herein intend to determine its function in SCI. Lentivirus was instilled to overexpress or knockdown FGF5 expression in mice. Compound C or H89 2HCl were used to suppress AMP-activated protein kinase (AMPK) or protein kinase A (PKA), respectively. FGF5 level was significantly decreased during SCI. FGF5 overexpression mitigated, while FGF5 silence further facilitated inflammatory response, oxidative damage and SCI. Mechanically, FGF5 activated AMPK to attenuate SCI in a cAMP/PKA-dependent manner, while inhibiting AMPK or PKA with pharmacological methods significantly abolished the neuroprotective effects of FGF5 against SCI. More importantly, serum FGF5 level was decreased in SCI patients, and elevated serum FGF5 level often indicate better prognosis. Our study identifies FGF5 as an effective therapeutic and prognostic target for SCI.

Exosomes from hypoxia-conditioned apical papilla stem cells accelerate angiogenesis in vitro through Notch/JAG1/VEGF signaling

Dental pulp angiogenesis is a committed step in pulp regeneration therapy, and exosomes provide a new cell-free choice for tissue regeneration. This study revealed the underlying regulatory mechanism of exosomes from stem cells of the apical papilla (SCAPs) under hypoxic state on angiogenesis of human umbilical vein endothelial cells (HUVECs) in vitro. Exosomes extracted from normoxia or hypoxia-pretreated SCAPs were co-cultured with HUVECs, and hypoxia pretreatment increased the release of exosomes and the internalization of exosomes by HUVECs. Compared to normoxic SCAPs-derived exosomes, exosomes from hypoxic SCAPs were found to promote cell proliferation and migration in HUVECs, as it was respectively determined by Cell Counting Kit-8, RT-qPCR and Transwell assay. Besides, hypoxia-educated SCAPs-exosomes especially enhanced the angiogenesis abilities of HUVECs in vitro, which were confirmed by tube formation assay and RT-qPCR detection of angiogenesis-related molecular markers. Interestingly, we found that the hypoxia inducible factor-1α (HIF-1α)/Notch1 signaling pathway was activated in hypoxic SCAPs, and protein jagged-1 (JAG1) was delivered by hypoxic SCAPs-derived exosomes to increase vascular endothelial growth factor (VEGF) production in HUVECs. Moreover, exogenous interference of JAG1 expression in HUVECs partially neutralized the activities of hypoxic SCAPs-exosomes in promoting cell proliferation, migration and tube formation of HUVECs. In summary, this study elucidates that exosomes from hypoxic SCAPs shows high potential to promote angiogenesis in vitro through the HIF-1α/JAG1/VEGF signaling cascade, which may provide a new perspective for the development of vascular reconstruction measures during dental regeneration engineering.

Akkermansia muciniphila and Lactobacillus plantarum ameliorate systemic lupus erythematosus by possibly regulating immune response and remodeling gut microbiota

Systemic lupus erythematosus (SLE), characterized by persistent inflammation, is a complex autoimmune disorder that affects all organs, challenging clinical treatment. Dysbiosis of gut microbiota promotes autoimmune disorders that damage extraintestinal organs. Modulating the gut microbiome is proposed as a promising approach for fine-running parts of the immune system, relieving systematic inflammation in multiple diseases. This study demonstrated that the administration of Akkermansia muciniphila and Lactobacillus plantarum contributed to an anti-inflammatory environment by decreasing IL-6 and IL-17 and increasing IL-10 levels in the circulation. The treatment of A. muciniphila and L. plantarum restored the intestinal barrier integrity to a different extent. In addition, both strains reduced the deposit of IgG in the kidney and improved renal function significantly. Further studies revealed distinct remodeling roles of A. muciniphila and L. plantarum administration on the gut microbiome. This work demonstrated essential mechanisms of how A. muciniphila and L. plantarum remodel gut microbiota and regulate the immune responses in the SLE mice model. IMPORTANCE Several pieces of research have demonstrated that certain probiotic strains contribute to regulating excessive inflammation and restoring tolerances in the SLE animal model. More animal trials combined with clinical studies are urgently needed to further elucidate the mechanisms for the effect of specific probiotic bacteria in preventing SLE symptoms and developing novel therapeutic targets. In this study, we explored the role of A. muciniphila and L. plantarum in ameliorating the SLE disease activity. Both A. muciniphila and L. plantarum treatment relieved the systemic inflammation and improved renal function in the SLE mouse model. We demonstrated that A. muciniphila and L. plantarum contributed to an anti-inflammatory environment by regulating cytokine levels in the circulation, restoring the intestinal barrier integrity, and remodeling the gut microbiome, however, to a different extent.

Comparative efficacy of five most common traditional Chinese medicine monomers for promoting recovery of motor function in rats with blunt spinal cord injury: a network meta-analysis

Objective

This research employed a network meta-analysis (NMA) to examine the effectiveness of five traditional Chinese medicine (TCM) monomers for promoting motor function recovery in rats with blunt spinal cord injury (SCI).

Methods

Wangfang, China National Knowledge Infrastructure, Web of Science, Embase, Chinese Scientific Journal Database, PubMed, and the Chinese Biomedical Literature Databases were searched for retrieving relevant articles published from their inception to December 2022. Two reviewers performed screening of search results, data extraction, and literature quality assessment independently.

Results

For this meta-analysis, 59 publications were included. Based on the recovery of motor function at weeks 1, 2, 3, and 4 in NMA, almost all TCM groups had significantly increased positive effects than the negative control animals. In terms of cumulative probability, the tanshinone IIA (TIIA) group ranked first in restoring motor function in the first week after blunt SCI, and the resveratrol (RSV) group ranked first during the last 3 weeks.

Conclusion

The NMA revealed that TCM monomers could effectively restore motor function in the rat model of blunt SCI. In rats with blunt SCI, TIIA may be the most effective TCM monomer during the first week, whereas RSV may be the most effective TCM monomer during the last 3 weeks in promoting motor function recovery. For better evidence reliability in preclinical investigations and safer extrapolation of those findings into clinical settings, further research standardizing the implementation and reporting of animal experiments is required.

Systematic Review Registration

https://inplasy.com/, identifier INPLASY202310070.

Targeted RASSF1A expression inhibits proliferation of HER2‑positive breast cancer cells in vitro

Human epidermal growth factor receptor 2-positive (HER2+) breast cancer, which accounts for 15-20% of all breast cancer, is associated with tumor recurrence and poor prognosis. RAS association domain family protein 1 subtype A (RASSF1A) is a tumor suppressor that is silenced in a variety of human cancers. The present study aimed to investigate the role of RASSF1A in HER2+ breast cancer and the therapeutic potential of RASSF1A-based targeted gene therapy for this malignancy. RASSF1A expression in human HER2+ breast cancer tissues and cell lines was evaluated by reverse transcription PCR and western blot analysis. The associations between tumorous RASSF1A level and tumor grade, TNM stage, tumor size, lymph node metastasis and five-year survival were examined. HER2+ and HER2-negative (HER2-) breast cancer cells were transfected with a lentiviral vector (LV-5HH-RASSF1A) that could express RASSF1A under the control of five copies of the hypoxia-responsive element (5HRE) and one copy of the HER2 promoter (HER2p). Cell proliferation was evaluated by the MTT and colony formation assays. It was found that tumorous RASSF1A level was negatively associated with tumor grade (P=0.014), TNM stage (P=0.0056), tumor size (P=0.014) and lymph node metastasis (P=0.029) and positively associated with five-year survival (P=0.038) in HER2+ breast cancer patients. Lentiviral transfection of HER2+ breast cancer cells resulted in increased RASSF1A expression and decreased cell proliferation, especially under hypoxic conditions. However, lentiviral transfection of HER2-breast cancer cells did not affect RASSF1A expression. In conclusion, these findings verified the clinical significance of RASSF1A as a tumor suppressor in HER2+ breast cancer and supported LV-5HH-RASSF1A as a potential targeted gene therapy for this malignancy.

Piezo1 (Piezo-Type Mechanosensitive Ion Channel Component 1)-Mediated Mechanosensation in Macrophages Impairs Perfusion Recovery After Hindlimb Ischemia in Mice

BACKGROUND

Angiogenesis is a promising strategy for those with peripheral artery disease. Macrophage-centered inflammation is intended to govern the deficiency of the angiogenic response after hindlimb ischemia. However, little is known about the mechanism of macrophage activation beyond signals from cytokines and chemokines. We sought to identify a novel mechanical signal from the ischemic microenvironment that provokes macrophages and the subsequent inflammatory cascade and to investigate the potential role of Piezo-type mechanosensitive ion channels (Piezo) on macrophages during this process.

METHODS

Myeloid cell-specific Piezo1 (Piezo-type mechanosensitive ion channel component 1) knockout (Piezo1^ΔMΦ) mice were generated by crossing Piezo1^fl/fl (LysM-Cre^-/-; Piezo1 flox/flox) mice with LysM-Cre transgenic mice to assess the roles of Piezo1 in macrophages after hindlimb ischemia. Furthermore, in vitro studies were carried out in bone marrow-derived macrophages to decipher the underlying mechanism.

RESULTS

We found that tissue stiffness gradually increased after hindlimb ischemia, as indicated by Young's modulus. Compared to Piezo2, Piezo1 expression and activation were markedly upregulated in macrophages from ischemic tissues in concurrence with increased tissue stiffness. Piezo1^ΔMΦ mice exhibited improved perfusion recovery by enhancing angiogenesis. Matrigel tube formation assays revealed that Piezo1 deletion promoted angiogenesis by enhancing FGF2 (fibroblast growth factor-2) paracrine signaling in macrophages. Conversely, activation of Piezo1 by increased stiffness or the agonist Yoda1 led to reduced FGF2 production in bone marrow-derived macrophages, which could be blocked by Piezo1 silencing. Mechanistically, Piezo1 mediated extracellular Ca²⁺ influx and activated Ca²⁺-dependent CaMKII (calcium/calmodulin-dependent protein kinase II)/ETS1 (ETS proto-oncogene 1) signaling, leading to transcriptional inactivation of FGF2.

CONCLUSIONS

This study uncovers a crucial role of microenvironmental stiffness in exacerbating the macrophage-dependent deficient angiogenic response. Deletion of macrophage Piezo1 promotes perfusion recovery after hindlimb ischemia through CaMKII/ETS1-mediated transcriptional activation of FGF2. This provides a promising therapeutic strategy to enhance angiogenesis in ischemic diseases.

Crosstalk between exosomes and autophagy in spinal cord injury: fresh positive target for therapeutic application

Spinal cord injury (SCI) is a very serious clinical traumatic illness with a very high disability rate. It not only causes serious functional disorders below the injured segment, but also causes unimaginable economic burden to social development. Exosomes are nano-sized cellular communication carriers that exist stably in almost all organisms and cell types. Because of their capacity to transport proteins, lipids, and nucleic acids, they affect various physiological and pathological functions of recipient cells and parental cells. Autophagy is a process that relies on the lysosomal pathway to degrade cytoplasmic proteins and organelles and involves a variety of pathophysiological processes. Exosomes and autophagy play critical roles in cellular homeostasis following spinal cord injury. Presently, the coordination mechanism of exosomes and autophagy has attracted much attention in the early efficacy of spinal cord injury. In this review, we discussed the interaction of autophagy and exosomes from the perspective of molecular mechanisms, which might provide novel insights for the early therapeutic application of spinal cord injury.

Biomaterial-Based bFGF Delivery for Nerve Repair

Diseases in the nervous system are common in the human body. People have to suffer a great burden due to huge economic costs and poor prognosis of the diseases. Many treatment modalities are now available that can make recovery better. Managing nutritional factors is also helpful for such diseases. The basic fibroblast growth factor (bFGF) is one of the major nutritional factors, which plays a crucial role in organogenesis and tissue homeostasis. It plays a role in cell proliferation, migration, and differentiation, thereby regulating angiogenesis and wound healing and repair of the muscle, bone, and nerve. The study on how to improve the stability of bFGF to increase the treatment effect for different diseases has garnered tremendous attention. Biomaterials are the popular methods to improve the stability of bFGF because they are safe for the living body as they are biocompatible. Biomaterials can be loaded with bFGF and delivered locally to achieve the goal of sustained bFGF release. In the present review, we report different types of biomaterials that are used for bFGF delivery for nerve repair and briefly report how the introduced bFGF can function in the nervous system. We aim to provide summative guidance for future studies about nerve injury using bFGF.

Analgesic effects and metabolome analyses of laser- and electro-acupuncture combined therapies in paclitaxel-induced neuropathic pain model

Introduction

Allodynia, which can be induced by paclitaxel administration, is the presence of pain as a result of a stimulus that does not usually provoke pain. Many studies have investigated the analgesic efficacy of acupuncture, including laser acupuncture (LA) and electroacupuncture (EA). Although pain-related diseases are relatively common, few studies have analyzed the analgesic effects and mechanisms of LA combined with EA. The purpose of this study was to investigate the therapeutic effect and mechanism of manual acupuncture (MA), EA, LA, and combined therapy (LA + EA) in a paclitaxel-induced allodynia rat model.

Methods

A total of 56 rats were classified into eight groups: a normal (Nor, n = 7), a control (Con, n = 7), an MA (n = 7), an EA (n = 7), a 650-nm LA (650LA, n = 7), an 830-nm LA (830LA, n = 7), a 650-nm LA combined with EA (650LA + EA, n = 7), and an 830-nm LA combined with EA group (830LA + EA, n = 7). Allodynia was induced by intraperitoneal injection of 2 mg/kg of paclitaxel every other day for a total of four times except the Nor group. Acupuncture treatments were conducted at the points of Jungwan (CV12) and Joksamni (ST36) once every other day for 6 min, for a total of nine times. Withdrawal response reaction times and force intensity of the foot were measured before the start of the experiment, after the 4th paclitaxel administration (day 8), and after the 9th and last treatment (day 15). On the 16th day, mRNA and protein expression in the spinal nerves was assessed, and a metabolome analysis of the animals' feces was performed.

Results and discussion

Our analyses show that 650LA + EA treatment resulted in an upregulation of protein expression related to pain relief and nerve regeneration, whereas 830LA + EA treatment led to significant changes in metabolomes. This study demonstrates that a combination treatment of EA and LA can suppress allodynia and promote upregulation of protein expression related to nerve regeneration and is effective in changing the intestinal microbiome. Further large-scale research is required to assess the exact mechanism underlying the therapeutic effect of this combination treatment in pain-related diseases.

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.

Network Pharmacology and Molecular Docking-Based Investigation of Potential Targets of Astragalus membranaceus and Angelica sinensis Compound Acting on Spinal Cord Injury

Background. Astragalus membranaceus (Huang-qi, AM) and Angelica sinensis (Dang-gui, AS) are common Chinese herbal medicines and have historically been used in spinal cord injury (SCI) therapies. However, the underlying molecular mechanisms of AM&AS remain little understood. The purpose of this research was to explore the bioactive components and the mechanisms of AM&AS in treating SCI according to network pharmacology and the molecular docking approach. Methods. AM&AS active ingredients were first searched from Traditional Chinese Medicine Systems Pharmacology (TCMSP) and Traditional Chinese Medicine Information Database (TCM-ID). Meanwhile, we collected relevant target genes of SCI through the GeneCards database, OMIM database, PharmGkb database, DurgBank database, and TDD database. By utilizing the STRING database, we constructed a network of protein-protein interactions (PPIs). In addition, we used R and STRING to perform GO and KEGG function enrichment analyses. Subsequently, AutoDock Vina was employed for a molecular docking study on the most active ingredients and most targeted molecules to validate the results of the network pharmacology analysis mentioned above. Result. The overall number of AM&AS active compounds identified was 22, while the number of SCI-related targets identified was 159. Then, the 4 key active ingredients were MOL000098 quercetin, MOL000422 kaempferol, MOL000354 isorhamnetin, and MOL000392 formononetin. A total of fourteen core targets were TP53, ESR1, MAPK1, MTC, HIF1A, HSP90AA1, FOS, MAPK14, STAT1, AKT1, EGFR, RELA, CCND1, and RB1. The KEGG enrichment analysis results indicated that lipid and atherosclerosis, PI3K-Akt signaling pathway, human cytomegalovirus infection, fluid shear stress, and atherosclerosis, etc., were enhanced with SCI development. Based on the analyses of docked molecules, four main active compounds had high affinity for the key targets. Conclusions. Altogether, it identified the mechanisms by which AM&AS was used for SCI treatment, namely, active ingredients, targets and signaling pathways. Consequently, further research into AM&AS treating SCI can be conducted on this scientific basis.

The roles and applications of neural stem cells in spinal cord injury repair

Spinal cord injury (SCI), which has no current cure, places a severe burden on patients. Stem cell-based therapies are considered promising in attempts to repair injured spinal cords; such options include neural stem cells (NSCs). NSCs are multipotent stem cells that differentiate into neuronal and neuroglial lineages. This feature makes NSCs suitable candidates for regenerating injured spinal cords. Many studies have revealed the therapeutic potential of NSCs. In this review, we discuss from an integrated view how NSCs can help SCI repair. We will discuss the sources and therapeutic potential of NSCs, as well as representative pre-clinical studies and clinical trials of NSC-based therapies for SCI repair.

Water Treadmill Training Ameliorates Neurite Outgrowth Inhibition Associated with NGR/RhoA/ROCK by Inhibiting Astrocyte Activation following Spinal Cord Injury

Spinal cord injury (SCI) often results in damage to or degeneration of axons. Crosstalk between astrocytes and neurons plays a pivotal role in neurite outgrowth following SCI. Rehabilitative training is a recognized method for the treatment of SCI, but the specific mechanism underlying its effect on axonal outgrowth in the central nervous system (CNS) has not yet been determined. A total of 190 adult male SD rats weighing 200–250 g were randomly divided into eight groups for use as animal models of SCI. Rats were subjected to water treadmill training (TT) for 7 or 14 d. The Basso-Beattie-Bresnahan (BBB) motor function scale, hematoxylin-eosin (HE) staining, Nissl staining, Western blotting, and immunofluorescence were used to measure tissue morphology and the degree of neurological deficit and to determine quantitative expression and accurate localization of the corresponding proteins. We found that TT decreased tissue structure damage and improved functional recovery. TT also promoted the regeneration of neurons and reduced SCI-induced apoptosis SCI around the lesion, as well as significantly increasing the expression of GAP43 and NF200 after SCI. In addition, TT significantly inhibited the injury-induced increase in the expression of proinflammatory factors. Moreover, TT reduced the activation of astrocytes and microglia, accompanied by the reduced expression of C3d and increased expression of S100A10. Finally, TT effectively reduced the level of chondroitin sulfate proteoglycan (CSPG) surrounding the lesion and inhibited the NGR/RhoA/ROCK signaling pathway in neurons after SCI. Overall, we found that TT played a novel role in recovery from SCI by promoting axonal outgrowth associated with NGR/RhoA/ROCK signaling by inhibiting astrocyte activation after SCI.

Metformin Protects against Spinal Cord Injury and Cell Pyroptosis via AMPK/NLRP3 Inflammasome Pathway

Spinal cord injury (SCI) is an extreme neurological impairment with few effective drug treatments. Pyroptosis is a recently found and proven type of programmed cell death that is characterized by a reliance on inflammatory caspases and the release of a large number of proinflammatory chemicals. Pyroptosis differs from other cell death mechanisms such as apoptosis and necrosis in terms of morphological traits, incidence, and regulatory mechanism. Pyroptosis is widely involved in the occurrence and development of SCI. In-depth research on pyroptosis will help researchers better understand its involvement in the onset, progression, and prognosis of SCI, as well as provide new therapeutic prevention and treatment options. Herein, we investigated the role of AMPK-mediated activation of the NLRP3 inflammasome in the neuroprotection of MET-regulated pyroptosis. We found that MET treatment reduced NLRP3 inflammasome activation by activating phosphorylated AMPK and reduced proinflammatory cytokine (IL-1β, IL-6, and TNF-α) release. At the same time, MET improved motor function recovery in rats after SCI by reducing motor neuron loss in the anterior horn of the spinal cord. Taken together, our study confirmed that MET inhibits neuronal pyroptosis after SCI via the AMPK/NLRP3 signaling pathway, which is mostly dependent on the AMPK pathway increase, hence decreasing NLRP3 inflammasome activation.

Microneedle-Mediated Biomimetic Cyclodextrin Metal Organic Frameworks for Active Targeting and Treatment of Hypertrophic Scars

Due to the lack of a delivery system that actively targets hypertrophic scar fibroblasts (HSFs), it is difficult to concentrate the effects of drugs on hypertrophic scars (HSs). We recently discovered that the HSF membrane has a homologous targeting effect and developed an active targeted drug delivery system for the local treatment of HSs. A diphenyl carbonate cross-linked cyclodextrin metal organic framework (CDF) containing more than 26% (w/w) quercetin (QUE) was coated with a HSF membrane (QUE@HSF/CDF) and then dispersed in Bletilla striata polysaccharide (BSP)-fabricated dissolvable microneedles (BSP-MNs-QUE@HSF/CDF) for local administration. This biomimetic nanodrug delivery system improved efficacy on HSs by regulating Wnt/β-catenin and JAK2/STAT3 pathways and reducing the expression of collagens I and III in HS, and this performance was superior to those of systems without HSF functionalization or the assistance of microneedles. Additionally, we found that BSP has synergistic effects and the microneedles have higher mechanical strength and better physical stability than microneedles made of hyaluronic acid. This currently designed drug delivery strategy integrating biomimetic nanoparticles and dissolvable microneedles is promising for applications in the fields of skin disease treatment and cosmetics.

The ROCK inhibitor Y-27632 ameliorates blood-spinal cord barrier disruption by reducing tight junction protein degradation via the MYPT1-MLC2 pathway after spinal cord injury in rats

The blood-spinal cord barrier (BSCB) is a physiological barrier between the blood and spinal cord parenchyma. This study aims to determine whether Y-27632, a Rho-associated protein kinase (ROCK) inhibitor, can protect the BSCB using in vivo models. The Evans blue fluorescence assay was used to detect leakage of the BSCB. Western blotting was used to define alterations in ROCK-related and tight junction (TJ) protein expression. Immunofluorescence triple-staining was used to evaluate histologic alterations in TJs. Locomotor function was evaluated using the open-field test, the Basso-Beattie-Bresnahan score, and footprint analysis. Two peaks of BSCB leakage after spinal cord injury (SCI) occurred at 24 h and 5 days. The ROCK inhibitor reduced the BSCB leakage at the second peak after SCI. Moreover, the ROCK inhibitor ameliorated the integrity of the BSCB and improved motor function recovery after SCI by regulating the phosphorylation of myosin phosphatase subunit-1 (MYPT1) and cofilin. ROCK inhibitors might protect the BSCB, which provides a new strategy for transitioning SCI treatment from the bench to bedside.

Parallels between the Developing Vascular and Neural Systems: Signaling Pathways and Future Perspectives for Regenerative Medicine

Neurovascular disorders, which involve the vascular and nervous systems, are common. Research on such disorders usually focuses on either vascular or nervous components, without looking at how they interact. Adopting a neurovascular perspective is essential to improve current treatments. Therefore, comparing molecular processes known to be involved in both systems separately can provide insight into promising areas of future research. Since development and regeneration share many mechanisms, comparing signaling molecules involved in both the developing vascular and nervous systems and shedding light to those that they have in common can reveal processes, which have not yet been studied from a regenerative perspective, yet hold great potential. Hence, this review discusses and compares processes involved in the development of the vascular and nervous systems, in order to provide an overview of the molecular mechanisms, which are most promising with regards to treatment for neurovascular disorders. Vascular endothelial growth factor, semaphorins, and ephrins are found to hold the most potential, while fibroblast growth factor, bone morphogenic protein, slits, and sonic hedgehog are shown to participate in both the developing vascular and nervous systems, yet have not been studied at the neurovascular level, therefore being of special interest for future research.

The role of hypoxia in stem cell regulation of the central nervous system: From embryonic development to adult proliferation

Hypoxia is involved in the regulation of various cell functions in the body, including the regulation of stem cells. The hypoxic microenvironment is indispensable from embryonic development to the regeneration and repair of adult cells. In addition to embryonic stem cells, which need to maintain their self-renewal properties and pluripotency in a hypoxic environment, adult stem cells, including neural stem cells (NSCs), also exist in a hypoxic microenvironment. The subventricular zone (SVZ) and hippocampal dentate gyrus (DG) are the main sites of adult neurogenesis in the brain. Hypoxia can promote the proliferation, migration, and maturation of NSCs in these regions. Also, because most neurons in the brain are non-regenerative, stem cell transplantation is considered as a promising strategy for treating central nervous system (CNS) diseases. Hypoxic treatment also increases the effectiveness of stem cell therapy. In this review, we firstly describe the role of hypoxia in different stem cells, such as embryonic stem cells, NSCs, and induced pluripotent stem cells, and discuss the role of hypoxia-treated stem cells in CNS diseases treatment. Furthermore, we highlight the role and mechanisms of hypoxia in regulating adult neurogenesis in the SVZ and DG and adult proliferation of other cells in the CNS.

Spinal Cord Injury Management through the Combination of Stem Cells and Implantable 3D Bioprinted Platforms

Spinal cord injury (SCI) has a major impact on affected patients due to its pathological consequences and absence of capacity for self-repair. Currently available therapies are unable to restore lost neural functions. Thus, there is a pressing need to develop novel treatments that will promote functional repair after SCI. Several experimental approaches have been explored to tackle SCI, including the combination of stem cells and 3D bioprinting. Implanted multipotent stem cells with self-renewing capacity and the ability to differentiate to a diversity of cell types are promising candidates for replacing dead cells in injured sites and restoring disrupted neural circuits. However, implanted stem cells need protection from the inflammatory agents in the injured area and support to guide them to appropriate differentiation. Not only are 3D bioprinted scaffolds able to protect stem cells, but they can also promote their differentiation and functional integration at the site of injury. In this review, we showcase some recent advances in the use of stem cells for the treatment of SCI, different types of 3D bioprinting methods, and the combined application of stem cells and 3D bioprinting technique for effective repair of SCI.

Hypoxia Response Element-Directed Expression of aFGF in Neural Stem Cells Promotes the Recovery of Spinal Cord Injury and Attenuates SCI-Induced Apoptosis

Reducing neuronal death after spinal cord injury (SCI) is considered to be an important strategy for the renovation of SCI. Studies have shown that, as an important regulator of the development and maintenance of neural structure, acidic fibroblast growth factor (aFGF) has the role of tissue protection and is considered to be an effective drug for the treatment of SCI. Neural stem cells (NSCs) are rendered with the remarkable characteristics to self-replace and differentiate into a variety of cells, so it is promising to be used in cell transplantation therapy. Based on the facts above, our main aim of this research is to explore the role of NSCs expressing aFGF meditated by five hypoxia-responsive elements (5HRE) in the treatment of SCI by constructing AAV–5HRE–aFGF–NSCs and transplanting it into the area of SCI. Our research results showed that AAV–5HRE–aFGF–NSCs can effectively restore the motor function of rats with SCI. This was accomplished by inhibiting the expression of caspase 12/caspase 3 pathway, EIF2α–CHOP pathway, and GRP78 protein to inhibit apoptosis.