Dynamic control of proinflammatory cytokines Il-1β and Tnf-α by macrophages in zebrafish spinal cord regeneration

ABSTRACTSpinal cord injury leads to a massive response of innate immune cells (microglia, macrophages, neutrophils) both, in non-regenerating mammals and in successfully regenerating zebrafish, but the role of these immune cells in functional spinal cord regeneration in zebrafish has not been addressed. Here we show that inhibiting inflammation reduces and promoting it accelerates axonal regeneration in larval zebrafish. Mutant analyses show that peripheral macrophages, but not neutrophils or microglia, are necessary and sufficient for full regeneration. Macrophage-less irf8 mutants show prolonged inflammation with elevated levels of Il-1β and Tnf-α. Decreasing Il-1β levels or number of Il-1β+ neutrophils rescues functional regeneration in irf8 mutants. However, during early regeneration, interference with Il-1β function impairs regeneration in irf8 and wildtype animals. Inhibiting Tnf-α does not rescue axonal growth in irf8 mutants, but impairs it in wildtype animals, indicating a pro-regenerative role of Tnf-α. Hence, inflammation is tightly and dynamically controlled by macrophages to promote functional spinal cord regeneration in zebrafish.

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Long noncoding RNA MALAT1 contributes to inflammatory response of microglia following spinal cord injury via the modulation of a miR-199b/IKKβ/NF-κB signaling pathway

AJP Cell Physiology ◽

10.1152/ajpcell.00278.2017 ◽

2018 ◽

Vol 315 (1) ◽

pp. C52-C61 ◽

Cited By ~ 37

Author(s):

Heng-Jun Zhou ◽

Li-Qing Wang ◽

Duan-Bu Wang ◽

Jian-Bo Yu ◽

Yu Zhu ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Inflammatory Response ◽

Signaling Pathway ◽

Proinflammatory Cytokines ◽

Long Noncoding Rna ◽

Noncoding Rna ◽

Tnf Α ◽

Cord Injury

Long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) was widely recognized to be implicated in human cancer, vascular diseases, and neurological disorders. This study was to explore the role and underlying mechanism of MALAT1 in acute spinal cord injury (ASCI). ASCI models in adult rats were established and demonstrated by a numerical decrease in BBB scores. Expression profile of MALAT1 and miR-199b following ASCI in rats and in vitro was determined using quantitative real-time PCR. RNA pull-down assays combined with RIP assays were performed to explore the interaction between MALAT1 and miR-199b. In the present study, MALAT1 expression was significantly increased (2.4-fold that of control) in the spinal cord of the rat contusion epicenter accompanied by activation of IKKβ/NF-κB signaling pathway and an increase in the level of proinflammatory cytokines TNF-α and IL-1β. Upon treatment with LPS, MALAT1 expression dramatically increased in the microglia in vitro, but knockdown of MALAT1 attenuated LPS-induced activation of MGs and TNF-α and IL-1β production. Next, we confirmed that LPS-induced MALAT1 activated IKKβ/NF-κB signaling pathway and promoted the production of proinflammatory cytokines TNF-α and IL-1β through downregulating miR-199b. More importantly, MALAT1 knockdown gradually improved the hindlimb locomotor activity of ASCI rats as well as inhibited TNF-α, IL-1β levels, and Iba-1 protein, the marker of activated microglia in injured spinal cords. Our study demonstrated that MALAT1 was dysregulated in ASCI rats and in LPS-activated MGs, and MALAT1 knockdown was expected to attenuate ASCI through repressing inflammatory response of MGs.

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Transcutaneous Electrical Nerve Stimulation Attenuates Postsurgical Allodynia and Suppresses Spinal Substance P and Proinflammatory Cytokine Release in Rats

Physical Therapy ◽

10.2522/ptj.20130306 ◽

2015 ◽

Vol 95 (1) ◽

pp. 76-85 ◽

Cited By ~ 14

Author(s):

Yu-Wen Chen ◽

Jann-Inn Tzeng ◽

Min-Fei Lin ◽

Ching-Hsia Hung ◽

Jhi-Joung Wang

Keyword(s):

Spinal Cord ◽

Substance P ◽

Proinflammatory Cytokines ◽

Nerve Stimulation ◽

Transcutaneous Electrical Nerve Stimulation ◽

Necrosis Factor Alpha ◽

Electrical Nerve Stimulation ◽

Mechanical Hypersensitivity ◽

Quick Recovery ◽

Tnf Α

BackgroundTranscutaneous electrical nerve stimulation (TENS) is often used for management of chronic pain.ObjectiveThe purpose of this study was to investigate whether TENS altered postincisional allodynia, substance P, and proinflammatory cytokines in a rat model of skin-muscle incision and retraction (SMIR).DesignThis was an experimental study.MethodsHigh-frequency (100-Hz) TENS therapy began on postoperative day 3 and was administered for 20 minutes daily to SMIR-operated rats by self-adhesive electrodes delivered to skin innervated via the ipsilateral dorsal rami of lumbar spinal nerves L1–L6 for the next 27 days. The expressions of substance P, tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1beta (IL-1β) in the spinal cord and mechanical sensitivity to von Frey stimuli (4g and 10g) were evaluated.ResultsThe SMIR-operated rats displayed a marked hypersensitivity to von Frey stimuli on postoperative day 3. In contrast to the SMIR-operated rats, SMIR-operated rats after TENS administration showed a quick recovery of mechanical hypersensitivity. On postoperative days 3, 16, and 30, SMIR-operated rats exhibited an upregulation of substance P and cytokines (TNF-α, IL-6, and IL-1β) in the spinal cord, whereas SMIR-operated rats after TENS therapy inhibited that upregulation. By contrast, the placebo TENS following SMIR surgery did not alter mechanical hypersensitivity and the levels of spinal substance P, TNF-α, IL-6, and IL-1β.LimitationsThe experimental data are limited to animal models and cannot be generalized to postoperative pain in humans.ConclusionsThe results revealed that TENS attenuates prolonged postoperative allodynia following SMIR surgery. Increased levels of spinal substance P and proinflammatory cytokines, activated after SMIR surgery, are important in the processing of persistent postsurgical allodynia. The protective effect of TENS may be related to the suppression of spinal substance P and proinflammatory cytokines in SMIR-operated rats.

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2-Bromopalmitate attenuates inflammatory pain by maintaining mitochondrial fission/fusion balance and function

Acta Biochimica et Biophysica Sinica ◽

10.1093/abbs/gmaa150 ◽

2020 ◽

Author(s):

Min Xie ◽

Menglin Cheng ◽

Bojun Wang ◽

Ming Jiao ◽

Liangzhu Yu ◽

...

Keyword(s):

Spinal Cord ◽

Proinflammatory Cytokines ◽

Inflammatory Pain ◽

Mitochondrial Fission ◽

In Vitro Study ◽

Intrathecal Administration ◽

Ros Production ◽

Tnf Α ◽

And Function

Abstract Inflammatory pain activates astrocytes and increases inflammatory cytokine release in the spinal cord. Mitochondrial fusion and fission rely on the functions of dynamin-related protein 1 (Drp1) and optic atrophy 1 (OPA1), which are essential for the synaptic transmission and plasticity. In the present study, we aimed to explore the effects of 2-bromopalmitate (2-BP), an inhibitor of protein palmitoylation, on the modulation of pain behavior. Rats were intraplantar injected with complete Freund’s adjuvant (CFA) to establish an inflammatory pain model. In the spinal cord of rats with CFA-induced inflammatory pain, the expression of astrocyte-specific glial fibrillary acidic protein (GFAP) and contents of proinflammatory cytokines IL-1β and TNF-α were increased. Mitochondrial Drp1 was increased, while OPA1 was decreased. Consequently, CFA induced reactive oxygen species (ROS) production and Bcl-2-associated X protein (BAX) expression. The intrathecal administration of 2-BP significantly reversed the pain behaviors of the inflammatory pain in rats. Moreover, 2-BP also reduced the Drp1 expression, elevated the OPA1 expression, and further reduced the GFAP, IL-1β, and TNF-α expression and ROS production. Furthermore, in vitro study proved a similar effect of 2-BP on the regulation of Drp1 and OPA1 expression. 2-BP also increased the mitochondrial membrane potential and decreased the levels of BAX, ROS, and proinflammatory cytokines. These results indicate that 2-BP may attenuate the inflammatory pain of CFA-treated rats via regulating mitochondrial fission/fusion balance and function.

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Dorsal Root Crush in Adult Mice to Study Spinal Cord Regeneration

BIO-PROTOCOL ◽

10.21769/bioprotoc/bio101.2460 ◽

2018 ◽

Vol 8 (1) ◽

Author(s):

Hyukmin Kim ◽

Harun Noristani ◽

Seung Han ◽

Young-Jin Son

Keyword(s):

Spinal Cord ◽

Dorsal Root ◽

Spinal Cord Regeneration ◽

Adult Mice

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The PI3K/Akt/FOXO3a pathway regulates regeneration following spinal cord injury in adult rats through TNF-α and p27kip1 expression

International Journal of Molecular Medicine ◽

10.3892/ijmm.2018.3459 ◽

2018 ◽

Cited By ~ 4

Author(s):

Honghui Lu ◽

Li-Hai Zhang ◽

Lin Yang ◽

Pei-Fu Tang

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Adult Rats ◽

P27kip1 Expression ◽

Tnf Α ◽

Cord Injury

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Do proinflammatory cytokines play a role in clozapine-associated glycometabolism disorders?

Psychopharmacology ◽

10.1007/s00213-021-05824-9 ◽

2021 ◽

Author(s):

Tongtong Zhao ◽

Kai Zhang ◽

Yelei Zhang ◽

Yating Yang ◽

Xiaoshuai Ning ◽

...

Keyword(s):

Blood Glucose ◽

Side Effects ◽

Proinflammatory Cytokines ◽

Peripheral Blood ◽

Animal Experiments ◽

Pancreatic Tissue ◽

Mouse Serum ◽

Healthy Controls ◽

Immunological Mechanisms ◽

Tnf Α

Abstract Rationale and objective Clozapine (CLZ) is the most effective drug for treatment-resistant schizophrenia but is associated with many side effects, including glycometabolism disorders. Immunological mechanisms may be involved in the development of clozapine side effects. Research relating the immunomodulatory effects of clozapine and its early markers to clinically relevant adverse events is needed to reduce the harmful side effects of clozapine. This study aimed to investigate the role of proinflammatory cytokines in clozapine-associated glycometabolism disorders. Methods We measured the effect of a range of doses of clozapine on glycometabolism-related parameters and proinflammatory cytokines levels in mice peripheral blood. We also examined the differences between these indicators in the peripheral blood of clozapine-treated schizophrenia patients and healthy controls. Furthermore, we detected proinflammatory cytokines expression in mice pancreatic tissue. Results Following clozapine administration, glucagon significantly decreased in mouse serum, and proinflammatory cytokine IL-β levels markedly increased. Clozapine reliably increased proinflammatory cytokines (IL-1β, IL-6, and TNF-α) expression in murine pancreatic tissue. Compared with healthy controls, clozapine-treated patients’ BMI, blood glucose, and proinflammatory cytokines (IL-1β, IL-6, and TNF-α) increased significantly. In clozapine-treated patients, a higher clozapine daily dosage was associated with higher levels of the proinflammatory cytokines IL-1β and IL-6, and a significant positive correlation was observed between blood glucose levels and the proinflammatory cytokines IL-6 and TNF-α. Conclusion Findings from animal experiments and clinical trials have shown clear evidence that clozapine has a regulatory effect on immune-related proinflammatory cytokines and influences glycometabolism indicators.

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Short-chain fatty acids contribute to neuropathic pain via regulating microglia activation and polarization

Molecular Pain ◽

10.1177/1744806921996520 ◽

2021 ◽

Vol 17 ◽

pp. 174480692199652

Author(s):

Feng Zhou ◽

Xian Wang ◽

Baoyu Han ◽

Xiaohui Tang ◽

Ru Liu ◽

...

Keyword(s):

Spinal Cord ◽

Neuropathic Pain ◽

Thermal Hyperalgesia ◽

Short Chain Fatty Acids ◽

Antibiotic Administration ◽

Tnf Α ◽

Microglia Polarization ◽

Inflammatory Phenotype ◽

Phenotype Markers ◽

Anti Inflammatory

Microglia activation and subsequent pro-inflammatory responses play a key role in the development of neuropathic pain. The process of microglia polarization towards pro-inflammatory phenotype often occurs during neuroinflammation. Recent studies have demonstrated an active role for the gut microbiota in promoting microglial full maturation and inflammatory capabilities via the production of Short-Chain Fatty Acids (SCFAs). However, it remains unclear whether SCFAs is involved in pro-inflammatory/anti-inflammatory phenotypes microglia polarization in the neuropathic pain. In the present study, chronic constriction injury (CCI) was used to induce neuropathic pain in mice, the mechanical withdrawal threshold, thermal hyperalgesia were accomplished. The levels of microglia markers including ionized calcium-binding adaptor molecule 1 (Iba1), cluster of differentiation 11b (CD11b), pro-inflammatory phenotype markers including CD68, interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and anti-inflammatory phenotype markers including CD206, IL-4 in the hippocampus and spinal cord were determined on day 21 after CCI. The results showed that CCI produced mechanical allodynia and thermal hyperalgesia, and also increased the expressions of microglia markers (Iba1, CD11b) and pro-inflammatory phenotype markers (CD68, IL-1β, and TNF-α), but not anti-inflammatory phenotype marker (CD206, IL-4) in the hippocampus and spinal cord, accompanied by increased SCFAs in the gut. Notably, antibiotic administration reversed these abnormalities, and its effects was also bloked by SCFAs administration. In conclusion, data from our study suggest that CCI can lead to mechanical and thermal hyperalgesia, while SCFAs play a key role in the pathogenesis of neuropathic pain by regulating microglial activation and subsequent pro-inflammatory phenotype polarization. Antibiotic administration may be a new treatment for neuropathic pain by reducing the production of SCFAs and further inhibiting the process of microglia polarization.

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Systemic Inflammation and the Breakdown of Intestinal Homeostasis Are Key Events in Chronic Spinal Cord Injury Patients

International Journal of Molecular Sciences ◽

10.3390/ijms22020744 ◽

2021 ◽

Vol 22 (2) ◽

pp. 744

Author(s):

David Diaz ◽

Elisa Lopez-Dolado ◽

Sergio Haro ◽

Jorge Monserrat ◽

Carlos Martinez-Alonso ◽

...

Keyword(s):

Spinal Cord ◽

Spinal Cord Injury ◽

Bacterial Translocation ◽

Binding Protein ◽

Gut Barrier ◽

Chronic Spinal Cord Injury ◽

Fatty Acid Binding ◽

Tnf Α ◽

Cord Injury ◽

Subset Distribution

Our aim was to investigate the subset distribution and function of circulating monocytes, proinflammatory cytokine levels, gut barrier damage, and bacterial translocation in chronic spinal cord injury (SCI) patients. Thus, 56 SCI patients and 28 healthy donors were studied. The levels of circulating CD14+highCD16−, CD14+highCD16+, and CD14+lowCD16+ monocytes, membrane TLR2, TLR4, and TLR9, phagocytic activity, ROS generation, and intracytoplasmic TNF-α, IL-1, IL-6, and IL-10 after lipopolysaccharide (LPS) stimulation were analyzed by polychromatic flow cytometry. Serum TNF-α, IL-1, IL-6 and IL-10 levels were measured by Luminex and LPS-binding protein (LBP), intestinal fatty acid-binding protein (I-FABP) and zonulin by ELISA. SCI patients had normal monocyte counts and subset distribution. CD14+highCD16− and CD14+highCD16+ monocytes exhibited decreased TLR4, normal TLR2 and increased TLR9 expression. CD14+highCD16− monocytes had increased LPS-induced TNF-α but normal IL-1, IL-6, and IL-10 production. Monocytes exhibited defective phagocytosis but normal ROS production. Patients had enhanced serum TNF-α and IL-6 levels, normal IL-1 and IL-10 levels, and increased circulating LBP, I-FABP, and zonulin levels. Chronic SCI patients displayed impaired circulating monocyte function. These patients exhibited a systemic proinflammatory state characterized by enhanced serum TNF-α and IL-6 levels. These patients also had increased bacterial translocation and gut barrier damage.

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