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1.
Front Pediatr ; 12: 1401090, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38745834

RESUMO

Introduction: Necrotizing enterocolitis (NEC) is a life-threatening inflammatory disease. Its onset might be triggered by Toll-Like Receptor 4 (TLR4) activation via bacterial lipopolysaccharide (LPS). We hypothesize that a deficiency of intestinal alkaline phosphatase (IAP), an enzyme secreted by enterocytes that dephosphorylates LPS, may contribute to NEC development. Methods: In this prospective pilot study, we analyzed intestinal resection specimens from surgical NEC patients, and from patients undergoing Roux-Y reconstruction for hepatobiliary disease as controls. We assessed IAP activity via enzymatic stainings and assays and explored IAP and TLR4 co-localization through immunofluorescence. Results: The study population consisted of five NEC patients (two Bell's stage IIb and three-stage IIIb, median (IQR) gestational age 25 (24-28) weeks, postmenstrual age at diagnosis 28 (26-31) weeks) and 11 controls (unknown age). There was significantly lower IAP staining in NEC resection specimens [49 (41-50) U/g of protein] compared to controls [115 (76-144), P = 0.03]. LPS-dephosphorylating activity was also lower in NEC patients [0.06 (0-0.1)] than in controls [0.3 (0.2-0.5), P = 0.003]. Furthermore, we observed colocalization of IAP and TLR4 in NEC resection specimens. Conclusion: This study suggests a significantly lower IAP level in resection specimens of NEC patients compared to controls. This lower IAP activity suggests a potential role of IAP as a protective agent in the gut, which needs further confirmation in larger cohorts.

2.
Neurosci Lett ; 832: 137806, 2024 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-38714229

RESUMO

BACKGROUND: Trigeminal neuralgia (TN) is a common and difficult-to-treat neuropathic pain disorder in clinical practice. Previous studies have shown that Toll-like receptor 4 (TLR4) modulates the activation of the NF-κB pathway to affect neuropathic pain in rats. Voltage-gated sodium channels (VGSCs) are known to play an important role in neuropathic pain electrical activity. OBJECTIVE: To investigate whether TLR4 can regulate Nav1.3 through the TRAF6/NF-κB p65 pathway after infraorbital nerve chronic constriction injury (ION-CCI). STUDY DESIGN: ION-CCI modeling was performed on SD (Sprague Dawley) rats. To verify the success of the modeling, we need to detect the mechanical pain threshold and ATF3. Then, detecting the expression of TLR4, TRAF6, NF-κB p65, p-p65, and Nav1.3 in rat TG. Subsequently, investigate the role of TLR4/TRAF6/NF-κB pathway in ION-CCI model by intrathecal injections of LPS-rs (TLR4 antagonist), C25-140 (TRAF6 inhibitor), and PDTC (NF-κB p65 inhibitor). RESULTS: ION-CCI surgery decreased the mechanical pain threshold of rats and increased the expression of ATF3, TLR4, TRAF6, NF-κB p-p65 and Nav1.3, but there was no difference in NF-κB p65 expression. After inject antagonist or inhibitor of the TLR4/TRAF6/NF-κB pathway, the expression of Nav1.3 was decreased and mechanical pain threshold was increased. CONCLUSION: In the rat model of ION-CCI, TLR4 in the rat trigeminal ganglion regulates Nav1.3 through the TRAF6/NF-κB p65 pathway, and TLR4 antagonist alleviates neuropathic pain in ION-CCI rats.


Assuntos
Canal de Sódio Disparado por Voltagem NAV1.3 , Ratos Sprague-Dawley , Transdução de Sinais , Fator 6 Associado a Receptor de TNF , Receptor 4 Toll-Like , Animais , Receptor 4 Toll-Like/metabolismo , Fator 6 Associado a Receptor de TNF/metabolismo , Masculino , Canal de Sódio Disparado por Voltagem NAV1.3/metabolismo , Transdução de Sinais/fisiologia , NF-kappa B/metabolismo , Neuralgia do Trigêmeo/metabolismo , Ratos , Modelos Animais de Doenças , Fator de Transcrição RelA/metabolismo , Fator 3 Ativador da Transcrição/metabolismo , Limiar da Dor/fisiologia
3.
J Biol Chem ; 300(6): 107384, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38762177

RESUMO

Antimicrobial resistance poses a serious threat to human health worldwide and its incidence continues to increase owing to the overuse of antibiotics and other factors. Macrolide antibiotics such as erythromycin (EM) have immunomodulatory effects in addition to their antibacterial activity. Long-term, low-dose administration of macrolides has shown clinical benefits in treating non-infectious inflammatory respiratory diseases. However, this practice may also increase the emergence of drug-resistant bacteria. In this study, we synthesized a series of EM derivatives, and screened them for two criteria: (i) lack of antibacterial activity and (ii) ability to suppress tumor necrosis factor-α (TNF-α) production in THP-1 cells stimulated with lipopolysaccharide. Among the 37 synthesized derivatives, we identified a novel 12-membered ring macrolide EM982 that lacked antibacterial activity against Staphylococcus aureus and suppressed the production of TNF-α and other cytokines. The effects of EM982 on Toll-like receptor 4 (TLR4) signaling were analyzed using a reporter assay and Western blotting. The reporter assay showed that EM982 suppressed the activation of transcription factors, NF-κB and/or activator protein 1 (AP-1), in HEK293 cells expressing human TLR4. Western blotting showed that EM982 inhibited the phosphorylation of both IκB kinase (IKK) ß and IκBα, which function upstream of NF-κB, whereas it did not affect the phosphorylation of p38 mitogen-activated protein kinase, extracellular signal-regulated kinase, and c-Jun N-terminal kinase, which act upstream of AP-1. These results suggest that EM982 suppresses cytokine production by inhibiting phosphorylation of IKKß and IκBα, resulting in the inactivation of NF-κB.


Assuntos
Citocinas , Quinase I-kappa B , Inibidor de NF-kappaB alfa , Humanos , Quinase I-kappa B/metabolismo , Fosforilação/efeitos dos fármacos , Inibidor de NF-kappaB alfa/metabolismo , Citocinas/metabolismo , Eritromicina/farmacologia , Eritromicina/química , Células THP-1 , Fator de Necrose Tumoral alfa/metabolismo , Antibacterianos/farmacologia , Antibacterianos/química , Macrolídeos/farmacologia , Macrolídeos/química , NF-kappa B/metabolismo , Transdução de Sinais/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Receptor 4 Toll-Like/metabolismo
4.
Zhongguo Zhen Jiu ; 44(4): 449-454, 2024 Apr 12.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-38621733

RESUMO

OBJECTIVES: To observe the effects of moxibustion on intestinal barrier function and Toll-like receptor 4 (TLR4)/nuclear factor-κB p65 (NF-κB p65) signaling pathway in obese rats and explore the mechanism of moxibustion in the intervention of obesity. METHODS: Fifty-five Wistar rats of SPF grade were randomly divided into a normal group (10 rats) and a modeling group (45 rats). In the modeling group, the obesity model was established by feeding high-fat diet. Thirty successfully-modeled rats were randomized into a model group, a moxibustion group, and a placebo-control group, with 10 rats in each one. In the moxibustion group, moxibustion was applied at the site 3 cm to 5 cm far from the surface of "Zhongwan" (CV 12), with the temperature maintained at (46±1 ) ℃. In the placebo-control group, moxibustion was applied at the site 8 cm to 10 cm far from "Zhongwan" (CV 12), with the temperature maintained at (38±1) ℃. The intervention was delivered once daily for 8 weeks in the above two groups. The body mass and food intake of the rats were observed before and after intervention in each group. Using ELISA methool, the levels of serum triacylglycerol (TG), total cholesterol (TC) and lipopolysaccharide (LPS) were detected and the insulin resistance index (HOMA-IR) was calculated. HE staining was used to observe the morphology of colon tissue. The mRNA expression of zonula occludens-1 (ZO-1), Occludin, Claudin-1, TLR4 and NF-κB p65 in the colon tissue was detected by quantitative real-time PCR; and the protein expression of ZO-1, Occludin, Claudin-1, TLR4 and NF-κB p65 was detected by Western blot in the rats of each group. RESULTS: Compared with the normal group, the body mass, food intake, the level of HOMA-IR, and the serum levels of TC, TG and LPS were increased in the rats of the model group (P<0.01); those indexes in the moxibustion group were all reduced when compared with the model group and the placebo-control group respectively (P<0.01, P<0.05). Compared with the normal group, a large number of epithelial cells in the mucosa of colon tissue was damaged, shed, and the inflammatory cells were infiltrated obviously in the interstitium in the rats of the model group. When compared with the model group, in the moxibustion group, the damage of the colon tissue was recovered to various degrees and there were few infiltrated inflammatory cells in the interstitium, while, the epithelial injury of the colon tissue was slightly recovered and the infiltrated inflammatory cells in the interstitium were still seen in the placebo-control group. The mRNA and protein expressions of ZO-1, Occludin and Caudin-1 were decreased in the model group compared with those in the normal group (P<0.01). When compared with the model group and the placebo-control group, the mRNA and protein expressions of these indexes were increased in the moxibustion group (P<0.01, P<0.05). In the model group, the mRNA and protein expressions of TLR4 and NF-κB p65 were increased when compared with those in the normal group (P<0.01), and the mRNA and protein expressions of these indexes were reduced in the moxibustion group when compared with those in the model group and the placebo-control group (P<0.01). CONCLUSIONS: Moxibustion can reduce the body mass and food intake, regulate the blood lipid and improve insulin resistance in the rats of obesity. It may be related to alleviating inflammatory response through improving intestinal barrier function and modulating the intestinal TLR4/NF-κB p65 signaling pathway.


Assuntos
Resistência à Insulina , Moxibustão , Ratos , Animais , NF-kappa B/genética , NF-kappa B/metabolismo , Ratos Wistar , Receptor 4 Toll-Like/genética , Lipopolissacarídeos/metabolismo , Função da Barreira Intestinal , Ocludina/metabolismo , Claudina-1/metabolismo , Transdução de Sinais , Obesidade/genética , Obesidade/terapia , RNA Mensageiro/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
5.
bioRxiv ; 2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38654826

RESUMO

During an infection, innate immune cells must adjust nature and strength of their responses to changing pathogen abundances. To determine how stimulation of the pathogen sensing TLR4 shapes subsequent macrophage responses, we systematically varied priming and restimulation concentrations of its ligand KLA. We find that different priming strengths have very distinct effects at multiple stages of the signaling response, including receptor internalization, MAPK activation, cytokine and chemokine production, and nuclear translocation and chromatin association of NFκB and IκB members. In particular, restimulation-induced TNF-α production required KLA doses equal to or greater than those used for prior exposure, indicating that macrophages can detect and adaptively respond to changing TLR4 stimuli. Interestingly, while such adaptation was dependent on the anti-inflammatory cytokine IL-10, exogenous concentrations of IL-10 corresponding to those secreted after strong priming did not exert suppressive effects on TNF-α without such prior priming, confirming the critical role of TLR4 stimulation history.

6.
Ren Fail ; 46(1): 2313176, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38482886

RESUMO

OBJECTIVE: This study was designed to observe the effect of toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) pathway activity on sepsis-associated acute kidney injury (SA-AKI), thereby providing new considerations for the prevention and treatment of SA-AKI. METHODS: The rats were divided into Sham, cecal ligation and puncture (CLP), CLP + vehicle, and CLP + TAK-242 groups. Except the Sham group, a model of CLP-induced sepsis was established in other groups. After 24 h, the indicators related to kidney injury in blood samples were detected. The pathological changes in the kidneys were observed by hematoxylin-eosin staining, and tubular damage was scored. Oxidative stress-related factors, mitochondrial dysfunction-related indicators in each group were measured; the levels of inflammatory factors in serum and kidney tissue of rats were examined. Finally, the expression of proteins related to the TLR4/NF-κB signaling pathway was observed by western blot. RESULTS: Compared with the CLP + vehicle and CLP + TAK-242 groups, the CLP + TAK-242 group reduced blood urea nitrogen (BUN), creatinine (Cr), cystatin-C (Cys-C), reactive oxygen species (ROS), malondialdehyde (MDA), and inflammatory factors levels (p < 0.01), as well as increased superoxide dismutase (SOD) activity of CLP rats (p < 0.01). Additionally, TAK-242 treatment improved the condition of CLP rats that had glomerular and tubular injuries and mitochondrial disorders (p < 0.01). Further mechanism research revealed that TAK-242 can inhibit the TLR4/NF-κB signaling pathway activated by CLP (p < 0.01). Above indicators after TAK-242 treatment were close to those of the Sham group. CONCLUSION: TAK-242 can improve oxidative stress, mitochondrial dysfunction, and inflammatory response by inhibiting the activity of TLR4/NF-κB signaling pathway, thereby preventing rats from SA-AKI.


Assuntos
Injúria Renal Aguda , Doenças Mitocondriais , Sepse , Sulfonamidas , Ratos , Animais , NF-kappa B/metabolismo , Receptor 4 Toll-Like/metabolismo , Transdução de Sinais , Injúria Renal Aguda/tratamento farmacológico , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/prevenção & controle , Sepse/complicações , Sepse/tratamento farmacológico , Sepse/metabolismo
7.
Exp Anim ; 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38508727

RESUMO

Transient receptor potential vanilloid 1 (TRPV1), a ligand-gated cation channel, is a receptor for vanilloids on sensory neurons and is also activated by capsaicin, heat, protons, arachidonic acid metabolites, and inflammatory mediators on neuronal or non-neuronal cells. However, the role of the TRPV1 receptor in pro-inflammatory cytokine secretion and its potential regulatory mechanisms in lipopolysaccharide (LPS)-induced inflammation has yet to be entirely understood. To investigate the role and regulatory mechanism of the TRPV1 receptor in regulating LPS-induced inflammatory responses, bone marrow-derived macrophages (BMDMs) harvested from wild-type (WT) and TRPV1 deficient (Trpv1-/-) mice were used as the cell model. In WT BMDMs, LPS induced an increase in the levels of tumor necrosis factor-α, interleukin-1ß, inducible nitric oxide synthase (iNOS), and nitric oxide, which were attenuated in Trpv1-/- BMDMs. Additionally, the phosphorylation of IκBα and mitogen-activated protein kinases, as well as the translocation of NF-κB and AP-1, were all decreased in LPS-treated Trpv1-/- BMDMs. Immunoprecipitation assay revealed that LPS treatment increased the formation of TRPV1-TLR4-CD14 complex in WT BMDMs. Genetic deletion of TRPV1 in BMDMs impaired the LPS-triggered immune-complex formation of TLR4, MyD88, and IRAK, all of which are essential regulators in LPS-induced activation of the TLR4 signaling pathway. Moreover, genetic deletion of TRPV1 prevented the LPS-induced lethality and pro-inflammatory production in mice. In conclusion, the TRPV1 receptor may positively regulate the LPS-mediated inflammatory responses in macrophages by increasing the interaction with the TLR4-CD14 complex and activating the downstream signaling cascade.

8.
Cardiovasc Diagn Ther ; 14(1): 158-173, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38434564

RESUMO

Background: Doxorubicin (Dox) can induce cardiotoxicity, thereby restricting the utility of this potent drug. Herein, the study ascertained the mechanism of the N6-methyladenosine (m6A) demethylase fat mass and obesity-associated protein (FTO) in pyroptosis and inflammation during Dox-induced heart failure (HF). Methods: Serum samples were collected from HF patients for detection of the expression of FTO and toll-like receptor 4 (TLR4). Dox-treated H9C2 cardiomyocytes were chosen for in vitro HF modeling, followed by measurement of FTO and TLR4 expression. Cardiomyocytes were detected for viability, apoptosis, spatial distribution of NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3), and the levels of lactic dehydrogenase, inflammatory factors, oxidative stress markers, and pyroptosis-related proteins. The m6A levels of mRNA were examined. RNA immunoprecipitation (RIP) and mRNA stability measurement were used to determine mRNA and protein expression, and RNA m6A dot blot and methylated-RIP assay were performed to detect m6A methylation levels. The expression of p-NF-κB p65 and p-IκB-α was measured by western blotting. Results: In the serum of HF patients, FTO was elevated while TLR4 was decreased. Dox treatment reduced FTO expression and increased m6A methylation levels and TLR4 expression in H9C2 cells. Overexpression of FTO and knockdown of TLR4 reduced apoptosis, cytotoxicity, inflammation, pyroptosis, oxidative stress, NLRP3 co-localization, and fluorescence intensity in Dox-induced H9C2 cells. Mechanistically, FTO resulted in reduced binding activity of YTHDF1 to TLR4 mRNA via m6A demethylation of TLR4, thus declining TLR4, p-NF-κB p65, and p-IκB-α expression. TLR4 knockdown counteracted the effects of FTO knockdown on Dox-induced H9C2 cells. Conclusions: FTO alleviated Dox-induced HF by blocking the TLR4/NF-κB pathway.

9.
Phytomedicine ; 128: 155344, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38493721

RESUMO

BACKGROUND: Among adults, stroke is the main causes of mortality and permanent disability. Neuroinflammation is one of the main causes of stoke-mediated neuronal death. Our previous study revealed that (E)-5-(2-(Quinolin-4-yl) vinyl) benzene-1, 3-diol (RV01), a quinolinyl analog of resveratrol, inhibits microglia-induced neuroinflammation and safeguards neurons from inflammatory harm. The preventive role of RV01 in ischemic stroke and its underlying cellular mechanisms and molecular targets remain poorly understood. PURPOSE: To investigate whether RV01 alleviates ischemia-reperfusion (I/R) injury by inhibiting microglia-mediated neuroinflammation and determine the potential molecular mechanisms and targets by which RV01 inhibits the I/R-mediated microglia activation. METHODS: Rat middle cerebral artery occlusion and reperfusion (MCAO/R) and BV-2 or primary microglial cells oxygen-glucose deprivation and reperfusion (OGD/R) models were established. The neurological behavior scores, 2, 3, 5-triphenyl tetrazolium chloride staining and immunofluorescence were used to detect the neuroprotective effect of RV01 in the MCAO/R rats. In addition, the mRNA expression levels of IL-6, TNF-α, and IL-1ß were detected to reveal the antineuroinflammatory effect of RV01. Moreover, a western blot assay was performed to explore the protein expression changes in NF-κB-mediated neuroinflammation. Finally, we identified TLR4 as an RV01 target through molecular docking, drug sensitivity target stability analysis, cellular thermal shift analysis, and surface plasmon resonance techniques. RESULTS: RV01 reduced the infarct volume and neurological deficits, increased the rotarod duration, and decreased the number of rightward deflections in the MCAO/R rats. RV01 inhibited the NF-κB signaling pathway in vitro and in vivo, as demonstrated by the reduction in the transcription factor p65-mediated expression of several inflammatory factors including IL-6, TNF-α, and IL-1ß. Further studies showed that its protective effect was associated with targeting the TLR4 protein. Notably, the anti-inflammatory effect of RV01 was markedly reinforced by the TLR4 knockdown, but inhibited by the overexpression of TLR4. Results revealed that the conditioned medium derived from the RV01-treated BV-2 cells significantly decreased the OGD/R-mediated neuronal damage. CONCLUSION: Our results are the first to reveal the protective effects of RV01 on cerebral ischemia, depending on its inhibitory effect on the NF-κB pathway by targeting TLR4. RV01 could be a potential protective agent in ischemic stroke treatment.


Assuntos
Anti-Inflamatórios , Infarto da Artéria Cerebral Média , Microglia , Fármacos Neuroprotetores , Ratos Sprague-Dawley , Traumatismo por Reperfusão , Resveratrol , Receptor 4 Toll-Like , Animais , Receptor 4 Toll-Like/metabolismo , Masculino , Infarto da Artéria Cerebral Média/tratamento farmacológico , Traumatismo por Reperfusão/tratamento farmacológico , Microglia/efeitos dos fármacos , Resveratrol/farmacologia , Fármacos Neuroprotetores/farmacologia , Ratos , Anti-Inflamatórios/farmacologia , AVC Isquêmico/tratamento farmacológico , Modelos Animais de Doenças , NF-kappa B/metabolismo , Doenças Neuroinflamatórias/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Simulação de Acoplamento Molecular
10.
Chem Pharm Bull (Tokyo) ; 72(2): 226-233, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38417868

RESUMO

Vizantin, 6,6'-bis-O-(3-nonyldodecanoyl)-α,α'-trehalose, has been developed as a safe immunostimulator on the basis of a structure-activity relationship study with trehalose 6,6'-dicorynomycolate. Our recent study indicated that vizantin acts as an effective Toll-like receptor-4 (TLR4) partial agonist to reduce the lethality of an immune shock caused by lipopolysaccharide (LPS). However, because vizantin has low solubility in water, the aqueous solution used in in vivo assay systems settles out in tens of minutes. Here, vizantin was chemically modified in an attempt to facilitate the preparation of an aqueous solution of the drug. This paper describes the concise synthesis of a water-soluble vizantin analogue in which all the hydroxyl groups of the sugar unit were replaced by sulfates. The vizantin derivative displayed micelle-forming ability in water and potent TLR-4 partial agonist activity.


Assuntos
Glicolipídeos , Lipopolissacarídeos , Trealose/análogos & derivados , Lipopolissacarídeos/farmacologia
11.
Artigo em Inglês | MEDLINE | ID: mdl-38361356

RESUMO

BACKGROUND: Cinnamic acid, an active compound in cinnamon spp., has anti-inflammatory and antioxidant characteristics and is favorable in managing inflammatory bowel diseases. OBJECTIVES: Evaluate cinnamic acid's effects on colitis in rats. METHODS: To induce colitis in experimental rats, excluding the sham group, a 4% intrarectal solution of acetic acid was administered. The rats were then given oral doses of cinnamic acid at 30, 45, and 90 mg/kg for two days. The animals were assessed for macroscopic and microscopic changes, and the levels of inflammatory mediators such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and myeloperoxidase (MPO) were measured using Eliza kits. Additionally, real-time PCR was performed to examine the gene level of toll-like receptor 4 (TLR-4) in the colon. RESULTS: Effective reduction of inflammation in acetic acid-induced colitis was achieved through Cinnamic acid administration at doses of 45 and 90 mg/kg. The decrease was achieved by inhibiting the activities of TNF-α, IL-6, and MPO while downregulating the expression of TLR-4. It is important to note that macroscopic and microscopic evaluations were significant in determining the effectiveness of cinnamic acid in reducing inflammation. CONCLUSION: Downregulation of inflammatory cytokines and TLR-4 expression may contribute to cinnamic acid's anti-inflammatory effect.


Assuntos
Ácido Acético , Anti-Inflamatórios , Cinamatos , Colite , Modelos Animais de Doenças , Peroxidase , Receptor 4 Toll-Like , Animais , Masculino , Ratos , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Cinamatos/farmacologia , Cinamatos/uso terapêutico , Colite/tratamento farmacológico , Colite/induzido quimicamente , Colo/efeitos dos fármacos , Colo/patologia , Colo/metabolismo , Interleucina-6/metabolismo , Peroxidase/metabolismo , Ratos Wistar , Receptor 4 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
12.
Artigo em Inglês | MEDLINE | ID: mdl-38204244

RESUMO

INTRODUCTION: Toll-like receptor 4(TLR4) is a receptor that traditionally plays an important role in immunomodulation (regulation of the immune system) and the initiation of proinflammatory responses. TLR4 is used in the body to recognize molecular patterns of pathogens or damaged cells from outside. However, in recent years, it has also become clear that TLR4 can affect the immune system and the function of stem cells, especially mesenchymal stem cells. Therefore, understanding how TLR4 signaling works at the cellular and molecular level and using this knowledge in regenerative medicine could be potentially useful, especially in the treatment of adipose- derived mesenchymal stem cells (ADMSCs). How these cells can use TLR4 signaling when used to increase their regenerative potential and repair tissues is an area of research. AIMS: This study aims to elucidate the multifaceted role of TLR4-mediated signaling in ADMSCs. METHOD: Employing a comprehensive set of assays, including MTT for cell viability, flow cytometry for surface marker expression, and gene expression analysis, we demonstrate that TLR4 activation significantly modulates key aspects of ADMSC biology. Specifically, TLR4 signaling was found to regulate ADMSCs proliferation, surface marker expression, and regenerative capacity in a dose- and time-dependent manner. Furthermore, TLR4 activation conferred cytoprotective effects against Doxorubicin (DOX)-induced cellular apoptosis. RESULT: These findings suggest that TLR4 signaling could be used to enhance the regenerative abilities of ADMSCs and enable ADMSC-based therapies to be used more effectively for tissue engineering and therapeutic purposes. CONCLUSION: However, it is important to note that research in this area needs more details and clinical studies.

13.
Neurosci Res ; 204: 34-45, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38278218

RESUMO

Histones organize DNA within cellular nuclei, but they can be released from damaged cells. In peripheral tissues extracellular histones act as damage-associated molecular patterns (DAMPs) inducing pro-inflammatory activation of immune cells. Limited studies have considered DAMP-like activity of histones in the central nervous system (CNS); therefore, we studied the effects of extracellular histones on microglia, the CNS immunocytes, and on neuronal cells. Both the linker histone H1 and the core histone H3 induced pro-inflammatory activation of microglia-like cells by upregulating their secretion of NO and cytokines, including interferon-γ-inducible protein 10 (IP-10) and tumor necrosis factor-α (TNF). The selective inhibitors MMG-11 and TAK-242 were used to demonstrate involvement of toll-like receptors (TLR) 2 and 4, respectively, in H1-induced NO secretion by BV-2 microglia. H1, but not H3, downregulated the phagocytic activity of BV-2 microglia. H1 was also directly toxic to all neuronal cell types studied. We conclude that H1, and to a lesser extent H3, when released extracellularly, have the potential to act as a CNS DAMPs. Inhibition of the DAMP-like effects of extracellular histones on microglia and their neurotoxic activity represents a potential strategy for combating neurodegenerative diseases that are characterized by the adverse activation of microglia and neuronal death.


Assuntos
Histonas , Microglia , Neurônios , Histonas/metabolismo , Animais , Microglia/metabolismo , Microglia/efeitos dos fármacos , Camundongos , Neurônios/metabolismo , Neurônios/efeitos dos fármacos , Citocinas/metabolismo , Doenças Neuroinflamatórias/metabolismo , Linhagem Celular , Óxido Nítrico/metabolismo
14.
Brain ; 147(3): 1025-1042, 2024 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-37787114

RESUMO

Progress in the development of effective chemotherapy is producing a growing population of patients with acute and chronic painful chemotherapy-induced peripheral neuropathy (CIPN), a serious treatment-limiting side effect for which there is currently no US Food and Drug Administration-approved treatment. CIPNs induced by diverse classes of chemotherapy drugs have remarkably similar clinical presentations, leading to the suggestion they share underlying mechanisms. Sensory neurons share with immune cells the ability to detect damage associated molecular patterns (DAMPs), molecules produced by diverse cell types in response to cellular stress and injury, including by chemotherapy drugs. DAMPs, in turn, are ligands for pattern recognition receptors (PRRs), several of which are found on sensory neurons, as well as satellite cells, and cells of the immune system. In the present experiments, we evaluated the role of two PRRs, TLR4 and RAGE, present in dorsal root ganglion (DRG), in CIPN. Antisense (AS)-oligodeoxynucleotides (ODN) against TLR4 and RAGE mRNA were administered intrathecally before ('prevention protocol') or 3 days after ('reversal protocol') the last administration of each of three chemotherapy drugs that treat cancer by different mechanisms (oxaliplatin, paclitaxel and bortezomib). TLR4 and RAGE AS-ODN prevented the development of CIPN induced by all three chemotherapy drugs. In the reversal protocol, however, while TLR4 AS-ODN completely reversed oxaliplatin- and paclitaxel-induced CIPN, in rats with bortezomib-induced CIPN it only produced a temporary attenuation. RAGE AS-ODN, in contrast, reversed CIPN induced by all three chemotherapy drugs. When a TLR4 antagonist was administered intradermally to the peripheral nociceptor terminal, it did not affect CIPN induced by any of the chemotherapy drugs. However, when administered intrathecally, to the central terminal, it attenuated hyperalgesia induced by all three chemotherapy drugs, compatible with a role of TLR4 in neurotransmission at the central terminal but not sensory transduction at the peripheral terminal. Finally, since it has been established that cultured DRG neurons can be used to study direct effects of chemotherapy on nociceptors, we also evaluated the role of TLR4 in CIPN at the cellular level, using patch-clamp electrophysiology in DRG neurons cultured from control and chemotherapy-treated rats. We found that increased excitability of small-diameter DRG neurons induced by in vivo and in vitro exposure to oxaliplatin is TLR4-dependent. Our findings suggest that in addition to the established contribution of PRR-dependent neuroimmune mechanisms, PRRs in DRG cells also have an important role in CIPN.


Assuntos
Antineoplásicos , Neuralgia , Humanos , Estados Unidos , Animais , Ratos , Bortezomib , Oxaliplatina/toxicidade , Receptor 4 Toll-Like , Neuralgia/induzido quimicamente , Células Receptoras Sensoriais , Oligodesoxirribonucleotídeos , Paclitaxel , Antineoplásicos/toxicidade
15.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-1006551

RESUMO

ObjectiveMolecular docking and animal experiments were employed to explore the protective effect and mechanism of Da Chengqitang (DCQD) on intestinal barrier in septic mice. MethodText mining method was used to screen the active ingredients in DCQD. AutoDock Tools and Discovery Studio were used to study the interactions of active components with the core target proteins [claudin-1, tumor necrosis factor (TNF)-α, interleukin (IL)-6, endogenous antimicrobial peptide mCRAMP, Toll-like receptor 4 (TLR4), and myeloid differentiation primary response gene 88 (MyD88)] in sepsis. Fifty C57BL/6 mice were randomized into sham, model, low- and high-dose (4 g∙kg-1 and 8 g∙kg-1) DCQD, and ulinastatin groups (n=10). Before, during, and after the day of modeling surgery, each group was administrated with corresponding drugs. The mice in other groups except the model group were subjected to modeling by cecal ligation and puncture. Enzyme-linked immunosorbent assay (ELISA) was used measure the serum level of D-lactic acid to assess intestinal mucosa permeability. Hematoxylin-eosin staining was employed to observe the histopathological changes in the ileum and assess the intestinal mucosal damage and inflammatory infiltration. Western blotting was employed to determine the expression levels of tight junction proteins claudin-1 and occludin in the ileal tissue, which were indicative of the bowel barrier function. The TNF-α and IL-6 levels were measured by ELISA to assess the intestinal inflammation. The expression of mCRAMP in the ileal tissue was observed by immunohistochemistry. The mRNA levels of mCRAMP, TLR4, and MyD88 in mouse ileal tissue were determined by Real-time polymerase chain reaction, on the basis of which the mechanism of DCQD in protecting the intestinal barrier of septic mice was explored. ResultMolecular docking results showed that most of the 10 active ingredients of DCQD that were screened out by text mining could bind to sepsis targets by van der Waals force, hydrogen bonding, and other conjugated systems. The results of animal experiments showed that compared with the model group, low- or high-dose DCQD lowered the D-lactic acid level in the serum (P<0.01), alleviated damage to the ileal tissue and mucosal edema, protected the small intestine villus integrity, reduced inflammatory cell infiltration, promoted the expression of claudin-1 (P<0.01), lowered the IL-6 level (P<0.01), up-regulated the mRNA and protein levels of mCRAMP (P<0.01), and down-regulated the mRNA and protein levels of TLR4 and MyD88 (P<0.01) in the ileal tissue. In addition, high-dose DCQD lowered the TNF-α level and promoted the expression of occludin in the ileum tissue (P<0.01), and low-dose DCQD up-regulated the protein level of occludin in the ileum tissue (P<0.05). ConclusionDCQD has a protective effect on intestinal barrier in septic mice. It can reduce intestinal inflammation, repair intestinal mucosal damage, improve the tight junction protein level, and reduce intestinal mucosal permeability by up-regulating the mRNA and protein levels of mCRAMP and the down-regulating the expression of genes in the TLR4/MyD88 pathway.

16.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-1003409

RESUMO

ObjectiveTo explore the protective effect and mechanism of Zingiberis Rhizoma Recens alcohol extract on lipopolysaccharide (LPS)-induced acute lung injury in mice. MethodBalb/c mice were randomly divided into normal group, model group, dexamethasone group, and low- and high-dose Zingiberis Rhizoma Recens groups. Mice in the normal group were instilled with normal saline through the nose, and the other groups were instilled with normal saline containing LPS (50 μg). After 30 minutes of modeling, the dexamethasone group was gavaged with 5 mg·kg-1 of dexamethasone acetate solution, the low- and high-dose Zingiberis Rhizoma Recens groups were gavaged with different doses of (7, 14 g·kg-1) of Zingiberis Rhizoma Recens alcohol extract, and the normal group and the model group were gavaged with the same volume of water. After 24 hours of modeling, the total number of white blood cells in bronchoalceolar lavage fluid (BALF) was detected by cell counter, and the levels of the inflammatory factors including tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and superoxide dismutase (SOD), and myeloperoxidase (MPO) was detected by enzyme-linked immunosorbent assay (ELISA). Haematoxylin-eosin (HE) staining method was used to observe the pathological changes of lung tissue in each group, and the Western blot was used to detect the protein expression of nuclear transcription factor (NF)-κB p65, phosphorylation (p)-NF-κB p65, and Toll-like receptor 4 (TLR4) in lung tissue. ResultCompared with the normal group, the white blood cell count in BALF and the levels of TNF-α, IL-1β, IL-6, and MPO in the model group was increased (P<0.01), and the level of SOD was decreased (P<0.05). Pathological damage of lung tissue was obvious, and the protein expression of NF-κB p65, p-NF-κB p65, and TLR4 in lung tissue was increased (P<0.01). Compared with the model group, the white blood cell count in BALF and the levels of TNF-α, IL-1β, IL-6, and MPO in the treatment group was decreased (P<0.05,P<0.01), and the level of SOD was increased (P<0.05,P<0.01). Pathological damage of lung tissue was alleviated, and the protein expression of NF-κB p65, p-NF-κB p65, and TLR4 in lung tissue was decreased (P<0.01). ConclusionZingiberis Rhizoma Recens alcohol extract may play a protective role in LPS-induced acute lung injury in mice by inhibiting the TLR4/NF-κB signaling pathway.

17.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-1016483

RESUMO

Parkinson's disease (PD) is a common neurological degenerative disease in the middle-aged and elderly, characterized by pathological changes of progressive degeneration of dopaminergic neurons in the substantia nigra and Lewy body formation, with high prevalence and long course of disease. The drug is mainly used to treat PD in western medicine, and the early curative effect is remarkable. However, with the progression of the disease and the long-term use of the drug, the efficacy will be significantly reduced, or there may be sports complications, and the long-term efficacy is not good. As a traditional medical system, traditional Chinese medicine has a unique understanding of PD. Traditional Chinese medicine plays an important role in the treatment of PD, which is natural, mild, safe, and effective, and it can cooperate with western medicine to enhance its efficacy and reduce the adverse reactions of western medicine. The pathogenesis of PD is complex, involving multiple levels such as mitochondrial dysfunction and apoptosis. Neuroinflammation is also involved in the progressive degeneration of dopaminergic neurons in PD. The Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway is a classic inflammatory pathway, and its expression changes play an important role in the occurrence and development of inflammatory response in the body. In recent years, the research on this pathway in TCM is increasing. This paper summarized the literature of traditional Chinese and western medicine in the past 10 years and reviewed the relevant mechanism of TCM regulation of TLR4/NF-κB pathway in the treatment of PD from the aspects of TCM monomer, compound, and other TCM therapies, so as to provide some references for the search for new targets of drug therapy and gene therapy and the in-depth study of TCM prevention and treatment of PD.

18.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-1016459

RESUMO

ObjectiveTo investigate the effects of Tongluo Juanbi granules on chondrocyte apoptosis and Toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)/nuclear factor-κB (NF-κB) signaling pathway of rabbits with knee osteoarthritis (KOA) and study the mechanism of Tongluo Juanbi granules in the prevention and treatment of KOA. MethodThirty New Zealand rabbits were randomly assigned to the following five groups (n=6): sham group, model group, low-dose and high-dose groups of Tongluo Juanbi granules (4.1 and 8.2 g·kg-1·d-1), and celecoxib group (10.9 mg·kg-1·d-1). The KOA model was established by destabilization of the medial meniscus (DMM) for six weeks. Six weeks after the modeling, the drug was given once a day for eight weeks. The pathological changes of cartilago articularis were observed by hematoxylin-eosin (HE) staining and Safranin O-Fast Green staining. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was performed to detect chondrocyte apoptosis. Enzyme-linked immunosorbent assay (ELISA) was used to detect the contents of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in synovial fluid. The mRNA and protein expression levels of genes related to the TLR4/MyD88/NF-κB signaling pathway were detected by real-time fluorescence quantitative polymerase chain reaction (Real-time PCR) and Western blot, respectively. ResultCompared with the sham group, the cartilago articularis of the model group significantly degenerated. Mankin's score was increased (P<0.01), and the contents of IL-1β and TNF-α in synovial fluid were increased (P<0.01). The number of apoptosis of chondrocytes was increased (P<0.01). The mRNA and protein expressions of TLR4, MyD88, and NF-κB p65 in cartilage tissue were up-regulated (P<0.01), while the mRNA and protein expressions of Bcl-2 were down-regulated (P<0.01). Compared with the model group, chondrocyte degeneration in both low-dose and high-dose groups of Tongluo Juanbi granules was improved, and Mankin's score was decreased (P<0.01). The contents of IL-1β and TNF-α were decreased (P<0.01), and the number of apoptosis of chondrocytes was decreased (P<0.01). The mRNA and protein expressions of TLR4, MyD88, and NF-κB p65 in cartilage tissue were down-regulated (P<0.01), while the mRNA and protein expressions of Bcl-2 were up-regulated (P<0.01). In addition, in the above observation indicators, the high-dose group of Tongluo Juanbi granules was significantly superior to the low-dose group of Tongluo Juanbi granules. ConclusionTongluo Juanbi granules could inhibit chondrocyte apoptosis in rabbits with KOA and improve cartilage degeneration, which may be related to inhibiting inflammatory responses mediated by TLR4/MyD88/NF-κB signaling pathway.

19.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-1013364

RESUMO

Acute pancreatitis (AP) is one of the most clinically common acute digestive disorders characterized by quick onset,rapid progression,severe condition,and high mortality. If the disease is not timely intervened in the early stage,it can develop into severe AP in the later stage,which damages the long-term quality of life and brings serious economic burden to patients and their families. However, the pathogenesis of this disease is complex and has not been fully explained. The generation and development of AP is closely related to many signaling pathways. Among them,Toll-like receptor 4(TLR4),as a transmembrane signal transduction receptor,can mediate immune response and inflammatory response,and play a key role in the occurrence and development of AP. Traditional Chinese medicine(TCM)can regulate the TLR4 signaling pathway with multiple targets,multiple effects,and multiple administration methods to inhibit inflammatory response,and effectively intervene in the progression of AP, which has gradually become a new craze for preventing and treating AP. Many studies have shown that TCM has obvious advantages in the prevention and treatment of AP. It can effectively treat AP by regulating TLR4 signaling pathway,strengthening immune resistance and defense,and inhibiting inflammatory response. Despite of the research progress,there is still a lack of comprehensive review on TCM regulation of TLR4 signaling pathway in the treatment of AP. Therefore,the literature on TCM regulation of TLR4 signaling pathway published in recent years was systematically reviewed and elaborated,aiming to provide new ideas for the treatment of AP and further drug development.

20.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-1012713

RESUMO

Ulcerative colitis (UC) is a chronic inflammatory bowel disease primarily affecting the colon and rectum, with the typical symptoms such as abdominal pain, bloody diarrhea, and tenesmus. The pathogenesis of UC remains to be fully elucidated. The disease is prone to recurrence, seriously affecting the patients' quality of life. Conventional therapies for UC have limitations, including unsatisfactory clinical efficacy, lengthy courses, and adverse reactions. Therefore, there is an urgent need to explore new therapeutic agents. Peroxisome proliferator-activated receptor gamma (PPARγ), a ligand-dependent nuclear receptor protein that plays a crucial role in maintaining intestinal homeostasis, is closely associated with the onset and development of UC. Traditional Chinese medicine (TCM) has advantages such as multi-targeting and mild side effects in the treatment of UC. Recent studies have shown that TCM can exert the therapeutic effects on UC by modulating PPARγ. The TCM methods for regulating PPARγ include clearing heat, drying dampness, moving Qi, activating blood, resolving stasis, invigorating the spleen, warming the kidney, and treating with both tonification and elimination. On one hand, TCM directly activates PPARγ or mediates signaling pathways such as nuclear factor-κB (NF-κB), mitogen-activated protein kinase (MAPK), Toll-like receptor 4 (TLR4), and regulates helper T cell 17 (Th17)/regulatory T cell (Treg) balance to promote macrophage polarization from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype, thereby inhibiting intestinal inflammation. On the other hand, TCM regulates the intestinal metabolism to activate PPARγ, lower the nitrate level, and maintain local hypoxia. In this way, it can restore the balance between specialized anaerobes and facultative anaerobes, thereby improving the gut microbiota and treating UC. This article summarizes the role of PPARγ in UC and reviews the research progress of TCM in treating UC by intervening in PPARγ in the last five years, aiming to give insights into the treatment and new drug development for UC.

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