scholarly journals Gut Microbiota Disorders Promote Inflammation and Aggravate Spinal Cord Injury Through the TLR4/MyD88 Signaling Pathway

2021 ◽  
Vol 8 ◽  
Author(s):  
Zijie Rong ◽  
Yuliang Huang ◽  
Honghua Cai ◽  
Min Chen ◽  
Hao Wang ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Gut Microbiota ◽  
Signaling Pathway ◽  
Nerve Cells ◽  
Inflammatory Factors ◽  
Arginase 1 ◽  
Cord Injury ◽  
Anti Inflammatory ◽  
Myd88 Signaling

Background: In spinal cord injury (SCI), systemic inflammation and the death of nerve cells in the spinal cord are life threatening. The connection between gut microbiota and signaling pathways has been a hot research topic in recent years. The Toll-like receptor 4/Myeloid differentiation factor 88 (TLR4/MyD88) signaling pathway is closely related to the inflammatory response. This study explored whether the gut microbiota imbalance could affect the TLR4/MyD88 signaling pathway to regulate SCI to provide a new basis for SCI research and treatment.Methods: An SCI model was constructed to study the influence on the injury of gut microbiota. 16S amplicon sequencing was used to identify the diversity and abundance of gut microbes. Fecal microbiota transplantation was performed in mice with SCI. ELISA was used to detect the serum levels of pro-inflammatory and anti-inflammatory factors in mice. Hematoxylin and eosin staining was used to observe SCI in mice. Immunofluorescence was used to detect the rates of loss glial fibrillary acidic protein (GFAP), neuronal nuclear protein (NeuN), and ionized calcium-binding adapter molecule 1 (IBA1) in the spinal cord as indicators of apoptosis. The expression of the TLR4/MyD88 signaling pathway was detected by qRT-PCR and western blotting.Results: Significant differences were observed in the gut microbiota of SCI mice and normal mice. The gut microbiota of SCI mice was imbalanced. The levels of pro-inflammatory cytokines tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 in SCI mice were increased, as was the level of the toxic induced nitric oxide synthase. The levels of anti-inflammatory factors IL-4, transforming growth factor-β, and IL-10 were decreased, as was the level of arginase-1. The apoptosis rates of GFAP, NeuN, and IBA1 were increased. The TLR4/MyD88 signaling pathway was activated. In the SCI group, inflammation increased after fecal transplantation, apoptosis of GFAP, NeuN, and IBA1 increased, and SCI was more serious.Conclusion: The TLR4/MyD88 signaling pathway promotes the death of nerve cells by inducing inflammation. Gut microbiota dysregulation can lead to aggravated SCI by activating the TLR4/MyD88 signaling pathway.

scholarly journals Beyond the lesion site: minocycline augments inflammation and anxiety-like behavior following SCI in rats through action on the gut microbiota

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Emma K. A. Schmidt ◽  
Pamela J. F. Raposo ◽  
Abel Torres-Espin ◽  
Keith K. Fenrich ◽  
Karim Fouad
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Spinal Cord Injury ◽  
Nervous System ◽  
Gut Microbiota ◽  
Microglial Activation ◽  
Motor Recovery ◽  
Long Term Effects ◽  
Cord Injury ◽  
Anti Inflammatory

Abstract Background Minocycline is a clinically available synthetic tetracycline derivative with anti-inflammatory and antibiotic properties. The majority of studies show that minocycline can reduce tissue damage and improve functional recovery following central nervous system injuries, mainly attributed to the drug’s direct anti-inflammatory, anti-oxidative, and neuroprotective properties. Surprisingly the consequences of minocycline’s antibiotic (i.e., antibacterial) effects on the gut microbiota and systemic immune response after spinal cord injury have largely been ignored despite their links to changes in mental health and immune suppression. Methods Here, we sought to determine minocycline’s effect on spinal cord injury-induced changes in the microbiota-immune axis using a cervical contusion injury in female Lewis rats. We investigated a group that received minocycline following spinal cord injury (immediately after injury for 7 days), an untreated spinal cord injury group, an untreated uninjured group, and an uninjured group that received minocycline. Plasma levels of cytokines/chemokines and fecal microbiota composition (using 16s rRNA sequencing) were monitored for 4 weeks following spinal cord injury as measures of the microbiota-immune axis. Additionally, motor recovery and anxiety-like behavior were assessed throughout the study, and microglial activation was analyzed immediately rostral to, caudal to, and at the lesion epicenter. Results We found that minocycline had a profound acute effect on the microbiota diversity and composition, which was paralleled by the subsequent normalization of spinal cord injury-induced suppression of cytokines/chemokines. Importantly, gut dysbiosis following spinal cord injury has been linked to the development of anxiety-like behavior, which was also decreased by minocycline. Furthermore, although minocycline attenuated spinal cord injury-induced microglial activation, it did not affect the lesion size or promote measurable motor recovery. Conclusion We show that minocycline’s microbiota effects precede its long-term effects on systemic cytokines and chemokines following spinal cord injury. These results provide an exciting new target of minocycline as a therapeutic for central nervous system diseases and injuries.

scholarly journals The Repression of the HMGB1-TLR4-NF-κB Signaling Pathway by Safflower Yellow May Improve Spinal Cord Injury

2021 ◽  
Vol 15 ◽  
Author(s):  
Lu Wang ◽  
Benson O. A. Botchway ◽  
Xuehong Liu
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Signaling Pathway ◽  
Nuclear Translocation ◽  
Inflammatory Responses ◽  
Nerve Tissue ◽  
Inflammatory Factors ◽  
Spinal Cord Tissue ◽  
Pathophysiological Mechanism ◽  
Cord Injury

Spinal cord injury (SCI) often results in abnormal sensory and motor functions. Current interventions for SCI in the clinical setting are not effective partly due to the complexity concerning its pathophysiological mechanism. In the wake of SCI, considerable inflammatory cells assemble around the injured area that induces a series of inflammatory reactions and aggravates tissue lesions, thereby affecting the recovery of the damaged nerve tissue. Therefore, the inhibition of inflammatory responses can improve the repair of the injured spinal cord tissue. Safflower Yellow (SY) is the main active ingredient of Carthamus tinctorius. SY has anti-inflammatory effect, as it can inhibit IκBα phosphorylation to impede the NF-κB signaling pathway and p53 nuclear translocation. Besides, SY can limit the release of pro-inflammatory factors, which in turn may alleviate secondary SCI and prevent further complications. In this report, we analyze the pathophysiological mechanism of SCI, the role of inflammatory responses, and how SY interferes with the HMGB1-TLR-4-NF-κB signaling pathway to attenuate inflammatory responses in SCI.

A Pivotal Role of the Nrf2 Signaling Pathway in Spinal Cord Injury: A Prospective Therapeutics Study

2020 ◽  
Vol 19 (3) ◽  
pp. 207-219
Author(s):  
Saeed Samarghandian ◽  
Ali Mohammad Pourbagher-Shahri ◽  
Milad Ashrafizadeh ◽  
Haroon Khan ◽  
Fatemeh Forouzanfar ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Signaling Pathway ◽  
Experimental Studies ◽  
Main Role ◽  
Related Factor ◽  
Nrf2 Signaling Pathway ◽  
Cord Injury ◽  
Anti Inflammatory ◽  
The Impact

The nuclear erythroid 2-related factor 2 (Nrf2) signaling pathway has a main role against oxidative stress and inflammation. Spinal Cord Injury (SCI) leads to the high secretion of inflammatory cytokines and reactive oxygen species, which disturbs nervous system function and regeneration. Several studies have indicated that the activation of the Nrf2 signaling pathway may be effective against inflammation after SCI. The experimental studies have indicated that many chemical and natural agents act as Nrf2 inducer, which inhibits the SCI progression. Thus, the finding of novel Nrf2- inducer anti-inflammatory agents may be a valuable approach in drug discovery. In the present review, we discussed the Nrf2 signal pathway and crosstalk with the NF-κB pathway and also the impact of this pathway on inflammation in animal models of SCI. Furthermore, we discussed the regulation of Nrf2 by several phytochemicals and drugs, as well as their effects on the SCI inhibition. Therefore, the current study presented a new hypothesis of the development of anti-inflammatory agents that mediate the Nrf2 signaling pathway for treating the SCI outcomes.

Interference of interleukin-1β mediated by lentivirus promotes functional recovery of spinal cord contusion injury in rats via the PI3K/AKT signaling pathway

2020 ◽  
Author(s):  
Yi-li Wang ◽  
Xi Hu ◽  
Qin-xuan Li ◽  
Li-xin Zhang ◽  
Qing-jie Xia ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Signaling Pathway ◽  
Motor Function ◽  
Akt Signaling ◽  
Inflammatory Factors ◽  
Akt Signaling Pathway ◽  
Cord Injury ◽  
Spinal Cord Contusion ◽  
Recovery Of Motor Function

Abstract Background: Spinal cord contusion (SCC) results in a series of pathophysiologic consequences such as edema, apoptosis, and inflammation. However, inflammation may also be beneficial for the recovery of motor function after SCC, but the underlying mechanisms remain incompletely elucidated. Interleukin-1 beta (IL-1β) is a pro-inflammatory factor that has synergistic effects with other inflammatory factors to aggravate spinal cord injury. Inflammatory factors have been found to activate the serine/threonine-specific protein kinase, protein kinase B (AKT) and to inhibit cell survival, but it is not clear whether inflammation upregulates the expression of IL-1β in the rat model of SCC and subsequently interferes in the phosphatidylinositol-3-kinase (PI3K)/AKT signaling pathway. Therefore, this study explored whether IL-1β affects the recovery of motor function in spinal cord injury by interfering with the PI3K/AKT signaling pathway. Method: SCC rats were established by the Allen method. The Basso Beattie Bresnahan (BBB) scoring was used to assess motor function in the spinal cord of injured rats. Quantitative polymerase chain reaction and Western blot were used to determine the expression of genes and proteins of IL-1β, PI3K, and AKT1. Immunohistochemistry and immunofluorescence were used to locate and detect IL-1β and AKT1 proteins in spinal cord tissue. To further explore the underlying mechanism of IL-1β, lentivirus was constructed by RNA interfering (RNAi) technique to inhibit the expression of IL-1β, and bioinformatics was applied to show the relationship between IL-1β and AKT1. Results: BBB scores decreased after SCC, and IL-1β and AKT1 was located in the cytoplasm of spinal cord anterior horn neurons. In the early stage of SCC, the expression level of IL-1β gene and protein in the experimental group was higher than that in the sham operated group. At the same time, expression of the AKT1 gene decreased. After expression of IL-1β mediated by lentivirus was inhibited, BBB scores increased significantly, and spinal cord motor function improved. Bioinformatic analysis revealed a relationship between IL-1β and AKT1. In addition, AKT1 gene expression was upregulated and PI3K expression was unchanged in the PI3K/AKT signaling pathway. Conclusion IL-1β not only exacerbates the inflammatory response after SCC, but also interferes with motor function. Inhibition of IL-1β may promote recovery of spinal cord injury by upregulating AKT1 in the PI3K/AKT signaling pathway, which provides a new perspective for future clinical practice in treating spinal cord injury

Bone marrow mesenchymal stem cells-derived exosomes reduce apoptosis and inflammatory response during spinal cord injury by inhibiting the TLR4/MyD88/NF-κB signaling pathway

2021 ◽  
pp. 096032712110033
Author(s):  
Liying Fan ◽  
Jun Dong ◽  
Xijing He ◽  
Chun Zhang ◽  
Ting Zhang
Keyword(s):  
Spinal Cord ◽  
Stem Cells ◽  
Bone Marrow ◽  
Spinal Cord Injury ◽  
Mesenchymal Stem Cells ◽  
Motor Function ◽  
Inflammatory Factors ◽  
Cord Injury ◽  
Marrow Mesenchymal Stem Cells ◽  
Apoptosis And Inflammation

Spinal cord injury (SCI) is one of the most common destructive injuries, which may lead to permanent neurological dysfunction. Currently, transplantation of bone marrow mesenchymal stem cells (BMSCs) in experimental models of SCI shows promise as effective therapies. BMSCs secrete various factors that can regulate the microenvironment, which is called paracrine effect. Among these paracrine substances, exosomes are considered to be the most valuable therapeutic factors. Our study found that BMSCs-derived exosomes therapy attenuated cell apoptosis and inflammation response in the injured spinal cord tissues. In in vitro studies, BMSCs-derived exosomes significantly inhibited lipopolysaccharide (LPS)-induced PC12 cell apoptosis, reduced the secretion of pro-inflammatory factors including tumor necrosis factor (TNF)-α and IL (interleukin)-1β and promoted the secretion of anti-inflammatory factors including IL-10 and IL-4. Moreover, we found that LPS-induced protein expression of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and nuclear transcription factor-κB (NF-κB) was significantly downregulated after treatment with BMSCs-derived exosomes. In in vivo studies, we found that hindlimb motor function was significantly improved in SCI rats with systemic administration of BMSCs-derived exosomes. We also observed that the expression of pro-apoptotic proteins and pro-inflammatory factors was significantly decreased, while the expression of anti-apoptotic proteins and anti-inflammatory factors were upregulated in SCI rats after exosome treatment. In conclusion, BMSCs-derived exosomes can inhibit apoptosis and inflammation response induced by injury and promote motor function recovery by inhibiting the TLR4/MyD88/NF-κB signaling pathway, which suggests that BMSCs-derived exosomes are expected to become a new therapeutic strategy for SCI.

scholarly journals Local Serpin Treatment via Chitosan-Collagen Hydrogel after Spinal Cord Injury Reduces Tissue Damage and Improves Neurologic Function

2020 ◽  
Vol 9 (4) ◽  
pp. 1221 ◽  
Author(s):  
Jacek M. Kwiecien ◽  
Liqiang Zhang ◽  
Jordan R. Yaron ◽  
Lauren N. Schutz ◽  
Christian J. Kwiecien-Delaney ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Tissue Damage ◽  
Low Dose ◽  
Dorsal Column ◽  
Neurological Deficits ◽  
Sustained Delivery ◽  
Post Surgery ◽  
Cord Injury ◽  
Anti Inflammatory

Spinal cord injury (SCI) results in massive secondary damage characterized by a prolonged inflammation with phagocytic macrophage invasion and tissue destruction. In prior work, sustained subdural infusion of anti-inflammatory compounds reduced neurological deficits and reduced pro-inflammatory cell invasion at the site of injury leading to improved outcomes. We hypothesized that implantation of a hydrogel loaded with an immune modulating biologic drug, Serp-1, for sustained delivery after crush-induced SCI would have an effective anti-inflammatory and neuroprotective effect. Rats with dorsal column SCI crush injury, implanted with physical chitosan-collagen hydrogels (CCH) had severe granulomatous infiltration at the site of the dorsal column injury, which accumulated excess edema at 28 days post-surgery. More pronounced neuroprotective changes were observed with high dose (100 µg/50 µL) Serp-1 CCH implanted rats, but not with low dose (10 µg/50 µL) Serp-1 CCH. Rats treated with Serp-1 CCH implants also had improved motor function up to 20 days with recovery of neurological deficits attributed to inhibition of inflammation-associated tissue damage. In contrast, prolonged low dose Serp-1 infusion with chitosan did not improve recovery. Intralesional implantation of hydrogel for sustained delivery of the Serp-1 immune modulating biologic offers a neuroprotective treatment of acute SCI.

An in vivo model of anti-inflammatory activity of subdural dexamethasone following the spinal cord injury

2016 ◽  
Vol 50 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Jacek M. Kwiecien ◽  
Bozena Jarosz ◽  
Wendy Oakden ◽  
Michal Klapec ◽  
Greg J. Stanisz ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Inflammatory Activity ◽  
In Vivo Model ◽  
Cord Injury ◽  
Anti Inflammatory
Sign in / Sign up

Export Citation Format

Share Document