Ginsenoside Rg1 Promotes the Migration of Olfactory Ensheathing Cells via the PI3K/Akt Pathway to Repair Rat Spinal Cord Injury

Ginsenoside Rg1 regulates astrocytes to promote angiogenesis in spinal cord injury via the JAK2/STAT3 signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Ginseng (Panax ginseng C. A. Mey) is a common traditional Chinese medicine used for anti-inflammation, anti-apoptosis, anti-oxidative stress, and neuroprotection. Ginsenosides Rg1, the main active components isolated from ginseng, may be a feasible therapy for spinal cord injury (SCI).

AIMS OF THE STUDY

SCI causes endothelial cell death and blood vessel rupture, ultimately resulting in long-term neurological impairment. As a result, encouraging spinal angiogenesis may be a feasible therapy for SCI. This investigation aimed to validate the capacity of ginsenoside Rg1 in stimulating angiogenesis within the spinal cord.

MATERIALS AND METHODS

Rats with SCI were injected intraperitoneally with ginsenoside Rg1. The effectiveness of ginsenoside Rg1 was assessed using the motor function score and the motor-evoked potential (MEP). Immunofluorescence techniques were applied to identify the spinal cord's angiogenesis. Angiogenic factors were examined through Western Blot (WB) and Immunohistochemistry. Oxygen-glucose deprivation (OGD) was employed to establish the hypoxia-ischemia model in vitro, and astrocytes (As) were given ginsenoside Rg1 and co-cultured with spinal cord microvascular endothelial cells (SCMECs). Immunofluorescence, wound healing test, and tube formation assay were used to identify the co-cultured SCMECs' activity. Finally, network pharmacology analysis and siRNA transfection were applied to verify the mechanism of ginsenoside Rg1 promoting angiogenesis.

RESULTS

The rats with SCI treated with ginsenoside Rg1 indicated more significant functional recovery, more pronounced angiogenesis, and higher levels of angiogenic factor expression. In vitro, the co-culture system with ginsenoside Rg1 intervention improved SCMECs' capacity for proliferating, migrating, and forming tubes, possibly by promoting the expression of vascular endothelial growth factor (VEGF) in As via the janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway.

CONCLUSION

Ginsenoside Rg1 can regulate As to promote angiogenesis, which may help to understand the mechanism of promoting SCI recovery.

Ginsenoside Rg1 reduces cardiac inflammation against myocardial ischemia/reperfusion injury by inhibiting macrophage polarization

Background

Myocardial ischemia/reperfusion (MI/R) injury is the main cause of death worldwide and poses a significant threat to cardiac health. Ginsenoside Rg1 has been shown to have inhibitory effects on inflammatory activation, oxidative stress, and cardiac injury, suggesting that Rg1 may have therapeutic effects on MI/R injury. However, the mechanism remains to be further studied.

Materials and methods

Left anterior descending coronary artery ligation was performed in Sprague-Dawley rats to construct an MI/R model in vivo. Organ index, electrocardiogram, infarct size, histopathological changes, and detection of cardiac injury and inflammatory factors in the rats were used to evaluate myocarditis, macrophage polarization, and fibrosis. We also used rat bone marrow-derived macrophages (BMDMs) to further investigate the effects of Rg1 on absent in melanoma 2 (AIM2) activation and macrophage polarization in vitro.

Results

Administration of Rg1 exhibited dose-dependent cardioprotective effects and effectively reduced MI/R injury. Rg1 significantly attenuated myocardial inflammation and inhibited M1 macrophage polarization during MI/R injury. Furthermore, Rg1 significantly reduced cardiac fibrosis in response to MI/R injury. This anti-fibrotic effect may contribute to the preservation of cardiac structure and function following an ischemic insult. Meanwhile, Rg1 effectively inhibited the activation of the AIM2 inflammasome in vitro, highlighting its potential as a key regulator of inflammatory pathways.

Conclusion

Our findings elucidate the multifaceted mechanisms underlying Rg1's cardioprotective effects, including its ability to mitigate inflammation, modulate macrophage polarization, and inhibit fibrosis.

Identification of potential biomarkers for neuromyelitis optica by quantitative proteomics

OBJECTIVE

Neuromyelitis optica (NMO) was a serious autoimmune inflammatory condition affecting the central nervous system. Currently, there was a lack of diagnostic biomarkers for AQP4-IgG-negative NMO patients.

METHODS

A comparative proteomic analysis was conducted on the CSF of 10 patients with NMO and 10 patients with non-inflammatory neurological disorders (NND) using tandem mass tagging technology. Differentially expressed proteins (DEPs) were analyzed using bioinformatic methods. The candidate proteins were then validated through ELISAs in a subsequent cohort of 160 samples, consisting of paired CSF and plasma samples from 50 NMO patients, CSF samples from 30 NND patients, and plasma samples from 30 healthy individuals.

RESULTS

We identified 389 proteins via proteomics, screening 79 DEPs. NCAM1, SST and AHSG were selected as candidate molecules for further validation. Compared to NND patients, there were decreased levels of AHSG in CSF and increased levels of NCAM1 and SST in NMO patients. The ELISA results revealed significantly higher levels of AHSG, SST and NCAM1 in the CSF of the NMO group compared to the NND group. Similarly, the serum levels of these three proteins were also higher in the NMO group compared to the healthy control group. It was found that serum NCAM1 levels significantly decreased in patients with non-relapsed NMO compared to patients with relapsed NMO and CSF NCAM1 level increased in patients with bilateral NMO compared to patients with unilateral NMO. Furthermore, CSF SST levels increased in AQP4 antibody-positive NMO patients compared to AQP4 antibody-negative patients.

INTERPRETATION

CSF NCAM1, serum NCAM1 and serum SST may serve as potential biomarkers for NMO patients and aid in the diagnosis of AQP4 antibody-negative NMO patients.

Olfactory ensheathing cells as candidate cells for chronic pain treatment

Chronic pain is often accompanied by tissue damage and pain hypersensitivity. It easily relapses and is challenging to cure, which seriously affects the patients' quality of life and is an urgent problem to be solved. Current treatment methods primarily rely on morphine drugs, which do not address the underlying nerve injury and may cause adverse reactions. Therefore, in recent years, scientists have shifted their focus from chronic pain treatment to cell transplantation. This review describes the classification and mechanism of chronic pain through the introduction of the characteristics of olfactory ensheathing cells (OECs), an in-depth discussion of special glial cells through the phagocytosis of nerve debris, receptor-ligand interactions, providing nutrition, and other inhibition of neuroinflammation, and ultimately supporting axon regeneration and mitigation of chronic pain. This review summarizes the potential and limitations of OECs for treating chronic pain by objectively analyzing relevant clinical trials and methods to enhance efficacy and future development prospects.

Kaempferol and ginsenoside Rg1 ameliorate acute hypobaric hypoxia induced lung injury based on network pharmacology analysis

Acute hypobaric hypoxia at high altitude can cause fatal non-cardiogenic high altitude pulmonary edema. Anti-inflammatory and anti-oxidant treatments appear to be a prospective way to alleviate acute hypoxia lung injury. Kaempferol (KA) and ginsenoside Rg1 (GRg1) can be isolated and purified from ginseng with anti-inflammatory, antioxidant, anti-carcinogenic, neuroprotective, and antiaging effects. However, their effects and pharmacological mechanisms on lung injury remains unclear. Network pharmacology analyses were used to explore potential targets of KA and GRg1 against acute hypobaric hypoxia induced lung injury. Rat lung tissues were further used for animal experiment verification. Among the putative targets of KA and GRg1 for inhibition of acute hypobaric hypoxia induced lung injury, AKT1, PIK3R1, PTK2, STAT3, HSP90AA1 and AKT2 were recognized as higher interrelated targets. And PI3K-AKT signaling pathway is considered to be the most important and relevant pathway. The rat experimental results showed that KA and GRg1 significantly improved histopathological changes and decreased pulmonary edema in rats with lung injury caused by acute hypobaric hypoxia. The concentrations of IL-6, TNF-α, MDA, SOD and CAT in rats treated with KA and GRg1 were significantly ameliorated. Protein and mRNA levels of PI3K and AKTI were significantly inhibited after KA administration. KA and GRg1 can lower lung water content, improve lung tissue damage, reduce the production of pro-inflammatory cytokines and the oxidative stress level.

The growth status and functions of olfactory ensheathing cells cultured on randomly oriented and aligned type-I-collagen-based nanofibrous scaffolds

Aim. The potential of olfactory ensheathing cells (OECs) as a cell therapy for spinal cord reconstruction and regeneration after injury has drawn significant attention in recent years. This study attempted to investigate the influences of nano-fibrous scaffolds on the growth status and functional properties of OECs.Methods.The ultra-morphology of the scaffolds was visualized using scanning electron microscopy (SEM). To culture OECs, donated cells were subcultured and identified with p75. Cell proliferation, apoptosis, and survival rates were measured through MTT assay, Annexin-V/PI staining, and p75 cell counting, respectively. The adhesion of cells cultured on scaffolds was observed using SEM. Additionally, the functions of OECs cultured on scaffolds were assessed by testing gene expression levels through real time polymerase chain reaction.Results.The electrospun type I collagen-based nano-fibers exhibited a smooth surface and uniform distribution. It was indicated that the proliferation and survival rates of OECs cultured on both randomly oriented and aligned type I collagen-based nano-fibrous scaffolds were higher than those observed in the collagen-coated control. Conversely, apoptosis rates were lower in cells cultured on scaffolds. Furthermore, OEC adhesion was better on the scaffolds than on the control. The expression levels of target genes were significantly elevated in cells cultured on scaffolds versus the controls.Conclusion.As a whole, the utilization of aligned collagen nanofibers has demonstrated significant advantages in promoting cell growth and improving cell function. These findings have important implications for the field of regenerative medicine and suggest that the approach may hold promise for the future therapeutic applications.

Liraglutide modulates adhesion molecules and enhances cell properties in three-dimensional cultures of olfactory ensheathing cells

Cell transplantation using olfactory ensheathing cells (OECs) is a promising approach for nerve repair but there are numerous limitations with their delivery method. Three-dimensional (3D) cell culture systems potentially offer a powerful approach for cell production and delivery options. To further optimise the use of OECs, strategies to promote cell viability and maintain cell behaviours in 3D cultures become important. We previously demonstrated an anti-diabetic drug, liraglutide, could modulate OEC migration and re-model extracellular matrix in two-dimensional (2D) cultures. In the present study, we further investigated its beneficial effects in our 3D culture system using primary OECs. OECs treated with liraglutide at 100 nM showed improved cell viability and had modulated expression of N-cadherin and β1-integrin (two important cell adhesion molecules). When formed into 3D spheroids, the pre-treated OECs generated spheroids with an increased volume and a decreased cell density compared to control spheroids. OECs that subsequently migrated out of the liraglutide pre-treated spheroids had higher capacity for migration with increased duration and length, which was attributed to a reduction in the pauses during the migration. Moreover, OECs that migrated out from liraglutide spheroids had a more bipolar morphology consistent with higher migratory capacity. In summary, liraglutide improved the viability of OECs, modulated cell adhesion molecules, and resulted in stable 3D cell constructs which conferred enhanced migratory capacity on the OECs. Overall, liraglutide may potentially improve the therapeutic use of OECs for neural repair by enhancing the generation of stable 3D constructs and increasing the migratory behaviour of OECs.

Recent advances in the combination of cellular therapy with stem cells and nanoparticles after a spinal cord injury

Background

Currently, combined therapies could help to reduce long-term sequelae of spinal cord injury (SCI); stem cell therapy at the site of injury in combination with other therapies has shown very promising results that can be transferred to the clinical field. Nanoparticles (NPs) are versatile technologies with applications to medical research for treatments of SCI since they could deliver therapeutic molecules to the target tissue and may help to reduce the side effects of non-targeted therapies. This article's purpose is to analyze and concisely describe the diverse cellular therapies in combination with NPs and their regenerative effect after SCI.

Methods

We reviewed the literature related to combinatory therapy for motor impairment following SCI that has been published by Web of Science, Scopus, EBSCO host, and PubMed databases. The research covers the databases from 2001 to December 2022.

Result

Animal models of SCI have shown that the combination of NPs plus stem cells has a positive impact on neuroprotection and neuroregeneration. Further research is required to better understand the effects and benefits of SCI on a clinical level; therefore, it is necessary to find and select the most effective molecules that are capable of exacerbating the neurorestorative effects of the different stem cells and then try them out on patients after SCI. On the other hand, we consider that synthetic polymers such as poly [lactic-co-glycolic acid] (PLGA) could be a candidate for the design of the first therapeutic strategy that combines NPs with stem cells in patients with SCI. The reasons for the selection are that PLGA has shown important advantages over other NPs, such as being biodegradable, having low toxicity levels, and high biocompatibility; In addition, researchers could control the release time and the biodegradation kinetics, and most importantly, it could be used as NMs on other clinical pathologies (12 studies on www.clinicaltrials.gov) and has been approved by the Federal Food, Drug, and Cosmetic Act (FDA).

Conclusion

The use of cellular therapy and NPs may be a worthwhile alternative for SCI therapy; however, it is expected that the data obtained from interventions after SCI reflect an important variability of molecules combined with NPs. Therefore, it is necessary to properly define the limits of this research to be able to continue to work on the same line. Consequently, the selection of a specific therapeutic molecule and type of NPs plus stem cells are crucial to evaluate its application in clinical trials.

miR-145a-5p/Plexin-A2 promotes the migration of OECs and transplantation of miR-145a-5p engineered OECs promotes the functional recovery in rats with SCI

BACKGROUND

Olfactory ensheathing cells (OECs) serve as a bridge by migrating at the site of spinal cord injury (SCI) to facilitate the repair of the neural structure and neural function. However, OEC migration at the injury site not only faces the complex and disordered internal environment but also is closely associated with the migration ability of OECs.

METHODS

We extracted OECs from the olfactory bulb of SD rats aged <7 days old. We verified the micro ribonucleic acid (miR)-145a-5p expression level in the gene chip after SCI and OEC transplantation using quantitative reverse transcription (qRT)-polymerase chain reaction (PCR). The possible target gene Plexin-A2 of miR-145a-5p was screened using bioinformatics and was verified using dual-luciferase reporter assay, Western blot, and qRT-PCR. The effect of miR-145a-5p/plexin-A2 on OEC migration ability was verified by wound healing assay, Transwell cell migration assay, and immunohistochemistry. Nerve regeneration was observed at the injured site of the spinal cord after OEC transplantation using tissue immunofluorescence and magnetic resonance imaging, diffusion tensor imaging, and the Basso-Beattie-Bresnahan locomotor rating scale were further used for imaging and functional evaluation.

RESULTS

miR-145a-5p expression in the injured spinal cord tissue after SCI considerably decreased, while Plexin-A2 expression significantly increased. OEC transplantation can reverse miR-145a-5p and Plexin-A2 expression after SCI. miR-145a-5p overexpression enhanced the intrinsic migration ability of OECs. As a target gene of miR-145a-5p, Plexin-A2 hinders OEC migration. OEC transplantation overexpressing miR-145a-5p after SCI can increase miR-145a-5p levels in the spinal cord, reduce Plexin-A2 expression in the OECs and the spinal cord tissue, and promote OEC migration and distribution at the injured site. OEC transplantation overexpressing miR-145a-5p can promote the regeneration and repair of neural morphology and neural function.

CONCLUSIONS

Our study demonstrated that miR-145a-5p could promote OEC migration to the injured spinal cord after cell transplantation by down-regulating the target gene Plexin-A2, thereby repairing the neural structure and function after SCI in rats.

Olfactory ensheathing cells and neuropathic pain

Damage to the nervous system can lead to functional impairment, including sensory and motor functions. Importantly, neuropathic pain (NPP) can be induced after nerve injury, which seriously affects the quality of life of patients. Therefore, the repair of nerve damage and the treatment of pain are particularly important. However, the current treatment of NPP is very weak, which promotes researchers to find new methods and directions for treatment. Recently, cell transplantation technology has received great attention and has become a hot spot for the treatment of nerve injury and pain. Olfactory ensheathing cells (OECs) are a kind of glial cells with the characteristics of lifelong survival in the nervous system and continuous division and renewal. They also secrete a variety of neurotrophic factors, bridge the fibers at both ends of the injured nerve, change the local injury microenvironment, and promote axon regeneration and other biological functions. Different studies have revealed that the transplantation of OECs can repair damaged nerves and exert analgesic effect. Some progress has been made in the effect of OECs transplantation in inhibiting NPP. Therefore, in this paper, we provided a comprehensive overview of the biology of OECs, described the possible pathogenesis of NPP. Moreover, we discussed on the therapeutic effect of OECs transplantation on central nervous system injury and NPP, and prospected some possible problems of OECs transplantation as pain treatment. To provide some valuable information for the treatment of pain by OECs transplantation in the future.

Ginsenoside Rg1 promotes astrocyte-to-neuron transdifferentiation in rat and its possible mechanism

INTRODUCTION

Neuronal loss caused by spinal cord injury (SCI) usually contributes to irreversible motor dysfunction. Promoting neuronal regeneration and functional recovery is vital to the repair of SCI.

AIMS

Astrocytes, activated by SCI with high proliferative capacity and proximity to neuronal lineage, are considered ideal cells for neuronal regeneration. As previous studies identified several small molecules for the induction of astrocyte-to-neuron, we confirmed that ginsenoside Rg1, a neuroprotective herb, could promote the direct transdifferentiation of astrocyte-to-neuron in rat.

METHODS AND RESULTS

Immunofluorescence staining showed that 26.0 ± 1.5% of the induced cells exhibited less astroglial properties and more neuronal markers with typical neuronal morphologies, reflecting 20.6 ± 0.9% of cholinergic neurons and 22.3 ± 1.9% of dopaminergic neurons. Western blot and qRT-PCR revealed that the induced cells had better antiapoptotic ability and Rg1-promoted neuronal transdifferentiation of reactive astrocytes might take effect through suppressing Notch/Stat3 signal pathway. In vivo, a revised SCI model treated by Rg1 was confirmed with faster functional recovery and less injury lesion cavity.

CONCLUSION

In summary, our study provided a novel strategy of direct transdifferentiation of endogenous rat reactive astrocytes into neurons with Rg1 and promotion of neuronal regeneration after SCI.

Mechanisms of ginsenosides exert neuroprotective effects on spinal cord injury: A promising traditional Chinese medicine

Spinal cord injury (SCI) is a devastating disorder of the central nervous system (CNS). It is mainly caused by trauma and reduces the quality of life of the affected individual. Ginsenosides are safe and effective traditional Chinese medicines (TCMs), and their efficacy against SCI is being increasingly researched in many countries, especially in China and Korea. This systematic review evaluated the neuroprotective effects of ginsenosides in SCI and elucidated their properties.

The effects of Ginsenosides on PI3K/AKT signaling pathway

Ginsenosides belong to a group of steroid glycosides that are extracted from the plant genus Panax (ginseng). This plant has been used for a long time for the treatment of a variety of disorders in traditional medicine. Recent studies have assessed the biological impact of Ginsenosides in cell culture or animal models. Animal studies have shown their beneficial impacts in the remedy of pathological conditions in different tissues. The ameliorating effects of Ginsenosides in diverse pathogenic conditions can be attributed to their effects on the production of reactive oxygen species. These substances mainly affect the activity of AMPK/AKT and PI3K/AKT pathways. The beneficial effects of Ginsenosides have been appraised in diabetes-related complications, spinal cord injury, cerebral ischemia, myocardial ischemia, and other disorders which are associated with oxidative stress. Moreover, these substances have been shown to interfere with the pathologic conditions during carcinogenesis. In the current study, we explain these impacts in two distinct sections including non-neoplastic conditions and neoplastic conditions.

The promoting effects of activated olfactory ensheathing cells on angiogenesis after spinal cord injury through the PI3K/Akt pathway

Objective

The aim of this study was to investigate the pro-angiogenic potential of olfactory ensheathing cells (OECs) activated by curcumin (CCM) and lipopolysaccharide (LPS) and the possible underlying mechanisms.

Methods

Vascular endothelial cells or tissues were cultured and treated with conditioned medium (CM) extracted from activated OECs activated through the addition of LPS and CCM or unactivated controls. Concomitantly, the pro-angiogenic potential of OECs was assessed in vitro by aortic ring sprouting assay, endothelial wound healing assay, CCK-8 assay, and tube formation assay. Subsequently, the OECs were co-cultured with endothelial cells to evaluate their promoting effect on endothelial cell proliferation and migration following a mechanical scratch. Moreover, the spinal cord injury (SCI) model in rats was established, and the number of endothelial cells and vascular structure in the injured area after SCI was observed with OEC transplantation. Finally, the underlying mechanism was investigated by western blot analysis of phosphorylated kinase expression with or without the MK-2206 (Akt-inhibitor).

Result

The present results showed that the activated OECs can effectively promote vascular endothelial cells' proliferation, migration, and vessel-like structure formation. Strikingly, several pro-angiogenic growth factors such as VEGF-A and PDGF-AA, which facilitate vessel formation, were found to be significantly elevated in CM. In addition, the PI3K/Akt signaling pathway was found to be involved in pro-angiogenic events caused by activated OEC CM, displaying higher phosphorylation levels in cells. In contrast, the delivery of MK2206 can effectively abrogate all the positive effects.

Conclusions

OECs activated by LPS and CCM have a pro-angiogenic effect and can effectively promote angiogenesis and improve the microenvironment at the injury site when transplanted in the injured spinal cord. This potentiated ability of OECs to provide pro-angiogenic effects is likely mediated through the PI3K/Akt pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-022-00765-y.

Ginseng extract and ginsenosides improve neurological function and promote antioxidant effects in rats with spinal cord injury: A meta-analysis and systematic review

Spinal cord injury (SCI) is defined as damage to the spinal cord that temporarily or permanently changes its function. There is no definite treatment established for neurological complete injury patients. This study investigated the effect of ginseng extract and ginsenosides on neurological recovery and antioxidant efficacies in rat models following SCI and explore the appropriate dosage. Searches were done on PubMed, Embase, and Chinese databases, and animal studies matches the inclusion criteria were selected. Pair-wise meta-analysis and subgroup analysis were performed. Ten studies were included, and the overall methodological qualities were low quality. The result showed ginseng extract and ginsenosides significantly improve neurological function, through the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale (pooled MD = 4.40; 95% CI = 3.92 to 4.88; p < 0.00001), significantly decrease malondialdehyde (MDA) (n = 290; pooled MD = −2.19; 95% CI = −3.16 to −1.22; p < 0.0001) and increase superoxide dismutase (SOD) levels (n = 290; pooled MD = 2.14; 95% CI = 1.45 to 2.83; p < 0.00001). Both low (<25 mg/kg) and high dosage (≥25 mg/kg) showed significant improvement in the motor function recovery in SCI rats. Collectively, this review suggests ginseng extract and ginsenosides has a protective effect on SCI, with good safety and a clear mechanism of action and may be suitable for future clinical trials and applications.

Optimizing Olfactory Ensheathing Cell Transplantation for Spinal Cord Injury Repair

Cell transplantation constitutes an important avenue for development of new treatments for spinal cord injury (SCI). These therapies are aimed at supporting neural repair and/or replacing lost cells at the injury site. To date, various cell types have been trialed, with most studies focusing on different types of stem cells or glial cells. Here, we review commonly used cell transplantation approaches for spinal cord injury (SCI) repair, with focus on transplantation of olfactory ensheathing cells (OECs), the glial cells of the primary olfactory nervous system. OECs are promising candidates for promotion of neural repair given that they support continuous regeneration of the olfactory nerve that occurs throughout life. Further, OECs can be accessed from the nasal mucosa (olfactory neuroepithelium) at the roof of the nasal cavity and can be autologously transplanted. OEC transplantation has been trialed in many animal models of SCI, as well as in human clinical trials. While several studies have been promising, outcomes are variable and the method needs improvement to enhance aspects such as cell survival, integration, and migration. As a case study, we include the approaches used by our team (the Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, QLD, Australia) to address the current problems with OEC transplantation and discuss how the therapeutic potential of OEC transplantation can be improved. Our approach includes discovery research to improve our knowledge of OEC biology, identifying natural and synthetic compounds to stimulate the neural repair properties of OECs, and designing three-dimensional cell constructs to create stable and transplantable cell structures.

Ginsenoside Rg1 Improves Differentiation by Inhibiting Senescence of Human Bone Marrow Mesenchymal Stem Cell via GSK-3β and β-Catenin

Objectives

To demonstrate the effect of Ginsenoside Rg1 on the differentiation of human bone marrow-derived mesenchymal stem cells (hBM-MSCs). Subsequently, a rational mechanism for the detection of Rg1 which affects mesenchymal stem cell differentiation was explored.

Methods

Flow cytometry is used for cell identification. The differentiation ability of hBM-MSCs was studied by differentiation culture. SA-β-gal staining is used to detect cell senescence levels. Western blot and immunofluorescence were used to determine protein expression levels. RT-qPCR is used to detect mRNA expression levels.

Results

Rg1 regulates the differentiation of hBM-MSCs. Differentiation culture analysis showed that Rg1 promoted cells to osteogenesis and chondrogenesis. Western blot results showed that Rg1 regulated the overactivation of the β-catenin signaling pathway and significantly adjusted the phosphorylation of GSK-3β. GSK-3β inhibitor (Licl) significantly increased Rg1-induced phosphorylation of GSK-3β, which in turn reduced Rg1-induced differentiation of hBM-MSCs.

Conclusion

Ginsenoside Rg1 can reduce the excessive activation of the Wnt pathway in senescent cells by inhibiting the phosphorylation of GSK-3β and regulate the mesenchymal stem cell differentiation ability.

Ginsenoside Rg1-induced activation of astrocytes promotes functional recovery via the PI3K/Akt signaling pathway following spinal cord injury

AIMS

To determine whether ginsenoside Rg1 is involved in scratch wound healing through altered expression of related molecules in astrocytes and improved functional recovery after spinal cord injury (SCI).

MATERIALS AND METHODS

Astrocytes were isolated from rats, followed by Rg1 treatment. The wound healing test was performed to observe the scratch wound healing in different groups. The expression of nerve growth factor (NGF), glial cell line-derived neurotrophic factor (GDNF), basic fibroblast growth factor (bFGF), and components of the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway were detected by western blot. Reverse transcription-polymerase chain reaction (RT-PCR) was used to measure the altered expression of laminin (LN) and fibronectin (FN). A revised Allen's method for the SCI model was performed, followed by Rg1 treatment. Then, functional scoring was conducted to evaluate the functional recovery. Hematoxylin-eosin (HE) staining showed changes in the void area. Finally, western blot assessed the expression of glial fibrillary acidic protein (GFAP) and chondroitin sulfate proteoglycans (CSPGs).

KEY FINDINGS

Rg1 mediated scratch wound healing through inducing an increased release of LN, FN, NGF, GDNF, and bFGF in vitro. Additionally, Rg1 activated the PI3K/Akt signaling pathway and promoted the functional recovery of hindlimb movement in rats. Furthermore, Rg1 significantly reduced the void area and downregulated the expression of GFAP and CSPGs.

SIGNIFICANCE

Rg1 not only enhanced the scratch wound repair in vitro through the release of astroglial neurotrophic factors, adhesion factors, and inhibitory factors, but it also improved the functional recovery in vivo following SCI.

Reliable cell purification and determination of cell purity: crucial aspects of olfactory ensheathing cell transplantation for spinal cord repair

Transplantation of olfactory ensheathing cells, the glia of the primary olfactory nervous system, has been trialed for spinal cord injury repair with promising but variable outcomes in animals and humans. Olfactory ensheathing cells can be harvested either from the lamina propria beneath the neuroepithelium in the nasal cavity, or from the olfactory bulb in the brain. As these areas contain several other cell types, isolating and purifying olfactory ensheathing cells is a critical part of the process. It is largely unknown how contaminating cells such as fibroblasts, other glial cell types and supporting cells affect olfactory ensheathing cell function post-transplantation; these cells may also cause unwanted side-effects. It is also, however, possible that the presence of some of the contaminant cells can improve outcomes. Here, we reviewed the last decade of olfactory ensheathing cell transplantation studies in rodents, with a focus on olfactory ensheathing cell purity. We analyzed how purification methods and resultant cell purity differed between olfactory mucosa- and olfactory bulb-derived cell preparations. We analyzed how the studies reported on olfactory ensheathing cell purity and which criteria were used to define cells as olfactory ensheathing cells. Finally, we analyzed the correlation between cell purity and transplantation outcomes. We found that olfactory bulb-derived olfactory ensheathing cell preparations are typically purer than mucosa-derived preparations. We concluded that there is an association between high olfactory ensheathing cell purity and favourable outcomes, but the lack of olfactory ensheathing cell-specific markers severely hampers the field.

Survival and Integration of Transplanted Olfactory Ensheathing Cells are Crucial for Spinal Cord Injury Repair: Insights from the Last 10 Years of Animal Model Studies

Olfactory ensheathing cells (OECs), the glial cells of the primary olfactory nervous system, support the natural regeneration of the olfactory nerve that occurs throughout life. OECs thus exhibit unique properties supporting neuronal survival and growth. Transplantation of OECs is emerging as a promising treatment for spinal cord injury; however, outcomes in both animals and humans are variable and the method needs improvement and standardization. A major reason for the discrepancy in functional outcomes is the variability in survival and integration of the transplanted cells, key factors for successful spinal cord regeneration. Here, we review the outcomes of OEC transplantation in rodent models over the last 10 years, with a focus on survival and integration of the transplanted cells. We identify the key factors influencing OEC survival: injury type, source of transplanted cells, co-transplantation with other cell types, number and concentration of cells, method of delivery, and time of transplantation after the injury. We found that two key issues are hampering optimization and standardization of OEC transplantation: lack of (1) reliable methods for identifying transplanted cells, and (2) three-dimensional systems for OEC delivery. To develop OEC transplantation as a successful and standardized therapy for spinal cord injury, we must address these issues and increase our understanding of the complex parameters influencing OEC survival.

siRNA-mediated NCAM1 gene silencing suppresses oxidative stress in pre-eclampsia by inhibiting the p38MAPK signaling pathway

Pre-eclampsia (PE), whose pathophysiology and etiology remain undefined, represents a leading consequence of fetal and maternal mortality and morbidity. Oxidative stress (OS) is recognized to involve in this disorder. In this study, we hypothesized that neural cell adhesion molecule 1 (NCAM1) gene silencing would suppress the OS in the pregnancy complicated by PE. Initially, clinical samples were collected for determination of NCAM1 expression in placental tissues and levels of OS products in blood. To assess the regulatory mechanism of NCAM1 knockdown on OS, we used small interfering RNA (siRNA) to silence NCAM1 expression in human umbilical vein endothelial cells (HUVECs). Next, cells were treated with or without hypoxia/reoxygenation to observe the level changes of OS products and p38 mitogen-activated protein kinase (p38MAPK) pathway-related genes. Finally, an evaluation of HUVEC migration and invasion abilities was conducted by wound-healing and transwell assays. Placenta of pregnancy with PE presented significantly increased NCAM1 expression in comparison to placenta of normal pregnancy. Meanwhile, enhanced OS in blood of pregnant women with PE was observed relative to women with normal pregnancy. siRNA-mediated knockdown of NCAM1 gene could inhibit the p38MAPK signaling pathway, repress OS, and promote cell migration and invasion in HUVECs, indicating that NCAM1 inhibition could reduce the influence of PE. Importantly, blocking the p38MAPK signaling pathway reversed the inhibitory role of NCAM1 gene silencing on PE. Collectively, this study defines potential role of NCAM1 gene silencing as a therapeutic target in PE through inhibiting OS and enhancing HUVEC migration and invasion by disrupting the p38MAPK signaling pathway.

Lipopolysaccharide induces human olfactory ensheathing glial apoptosis by promoting mitochondrial dysfunction and activating the JNK-Bnip3-Bax pathway

Olfactory ensheathing glia (OEG) play an important role in regulating the regeneration of an injured nervous system. However, chronic inflammation damage reduces the viability of OEG via poorly understood mechanisms. We aimed to investigate the pathological responses of OEG in response to LPS-mediated inflammation stress in vitro. The results indicated that lipopolysaccharide (LPS) treatment significantly reduced the viability of OEG in a dose-dependent fashion. Mechanistically, LPS stimuli induced mitochondrial oxidative damage, mitochondrial fragmentation, mitochondrial metabolism disruption, and mitochondrial apoptosis activation. Furthermore, we verified that LPS modulated mitochondrial apoptosis by promoting Bax upregulation, and this process was regulated by the JNK-Bnip3 pathway. Inhibition of the JNK-Bnip3 pathway prevented LPS-mediated Bax activation, thus attenuating OEG apoptosis. Altogether, our data illustrated that LPS-mediated inflammation injury evoked mitochondrial abnormalities in OEG damage via the JNK-Bnip3-Bax pathway. This finding provides a potential target to protect OEG against chronic inflammation stress.

Roles of ginsenosides in inflammasome activation

Inflammation is an innate immune response that protects the body from pathogens, toxins, and other dangers and is initiated by recognizing pathogen-associated molecular patterns or danger-associated molecular patterns by pattern-recognition receptors expressing on or in immune cells. Intracellular pattern-recognition receptors, including nucleotide-binding oligomerization domain-like receptors (NLRs), absent in melanoma 2, and cysteine aspartate–specific protease (caspase)-4/5/11 recognize various pathogen-associated molecular patterns and danger-associated molecular patterns and assemble protein complexes called “inflammasomes.” These complexes induce inflammatory responses by activating a downstream effector, caspase-1, leading to gasdermin D –mediated pyroptosis and the secretion of proinflammatory cytokines, such as interleukin (IL)-1β and IL-18. Ginsenosides are natural steroid glycosides and triterpene saponins found exclusively in the plant genus Panax. Various ginsenosides have been identified, and their abilities to regulate inflammatory responses have been evaluated. These studies have suggested a link between ginsenosides and inflammasome activation in inflammatory responses. Some types of ginsenosides, including Rh1, Rg3, Rb1, compound K, chikusetsu saponin IVa, Rg5, and Rg1, have been clearly demonstrated to inhibit inflammatory responses by suppressing the activation of various inflammasomes, including the NLRP3, NLRP1, and absent in melanoma 2 inflammasomes. Ginsenosides have also been shown to inhibit caspase-1 and to decrease the expression of IL-1β and IL-18. Given this body of evidence, the functional relationship between ginsenosides and inflammasome activation provides new insight into the understanding of the molecular mechanisms of ginsenoside-mediated antiinflammatory actions. This relationship also has applications regarding the development of antiinflammatory remedies by ginsenoside-mediated targeting of inflammasomes, which could be used to prevent and treat inflammatory diseases.