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Depression, recognized globally as a primary cause of disability, has its pathogenesis closely related to neuroinflammation and neuronal damage. Arctiin (ARC), the major bioactive component of Fructus arctii, has various pharmacological activities, such as anti-inflammatory and neuroprotective effects. Building on previous findings that highlighted ARC's capability to mitigate depression by dampening microglial hyperactivation and thereby reducing neuroinflammatory responses and cortical neuronal damage in mice, the current study delves deeper into ARC's therapeutic potential by examining its impact on hippocampal neuronal damage in depression. Utilizing both chronic unpredictable mild stress (CUMS)-induced depression model in mice and corticosterone (CORT)-stimulated PC12 cell model of neuronal damage, the techniques including Nissl staining, immunohistochemistry, western blotting, ELISA, lactate dehydrogenase assays, colony formation assays, immunofluorescence staining and molecular docking were employed to unravel the mechanisms behind ARC's neuroprotective effects. The findings revealed that ARC not only mitigates hippocampal neuropathological damage and reduces serum CORT levels in CUMS-exposed mice but also enhances cell activity while reducing lactate dehydrogenase release in CORT-stimulated PC12 cells. ARC attenuated neuroinflammatory responses and neuronal apoptosis by inhibiting the overactivation of the P2X7 receptor (P2X7R)/NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome signaling pathway, similar to the effect of A438079 (P2X7R antagonist). Interestingly, pretreatment with A438079 blocked the neuroprotective effect of ARC. Computer modeling predicted that both ARC and A438079 have strong binding with P2X7R and they have the same binding site. These results suggested that ARC may exert a neuroprotective role by binding to P2X7R, thereby inhibiting the P2X7R/NLRP3 inflammasome signaling pathway.
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ETHNOPHARMACOLOGICAL RELEVANCE: Coix seed, the dry mature seed kernel of the gramineous plant coix (Coix lacryma-jobi L. var. ma-yuen Stapf), is widely consumed as a traditional Chinese medicine and functional food in China and South Korea. We have previously demonstrated the protective effect of coixol, a polyphenolic compound extracted from coix, against Toxoplasma gondii (T. gondii) infection-induced lung injury. However, the protective effect of coixol on hepatic injury induced by T. gondii infection have not yet been elucidated. AIM OF THE STUDY: This study explores the impact of coixol on T. gondii infection-induced liver injury and elucidates the underlying molecular mechanisms. MATERIALS AND METHODS: Female BALB/c mice and Kupffer cells (KCs) were employed to establish an acute T. gondii infection model in vivo and an inflammation model in vitro. The study examined coixol's influence on the T. gondii-derived heat shock protein 70 (T.g.HSP70)/toll-like receptor 4 (TLR4)/nuclear factor (NF)-κB signaling pathway in T. gondii-infected liver macrophages. Furthermore, a co-culture system of KCs and NCTC-1469 hepatocytes was developed to observe the impact of liver macrophages infected with T. gondii on hepatocyte injury. RESULTS: Coixol notably inhibited the proliferation of tachyzoites and the expression of T.g.HSP70 in mouse liver and KCs, and attenuated pathological liver injury. Moreover, coixol decreased the production of high mobility group box 1, tumor necrosis factor-α, and inducible nitric oxide synthase by suppressing the TLR4/NF-κB signaling pathway in vitro and in vivo. Coixol also mitigated KCs-mediated hepatocyte injury. CONCLUSIONS: Coixol protects against liver injury caused by T. gondii infection, potentially by diminishing hepatocyte injury through the suppression of the inflammatory cascade mediated by the T.g.HSP70/TLR4/NF-κB signaling pathway in KCs. These findings offer new perspectives for developing coixol as a lead compound for anti-T. gondii drugs.
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BACKGROUND: Infection by Toxoplasma gondii can lead to severe pneumonia, with current treatments being highly inadequate. The NLRP3 inflammasome is one member of the NOD-like receptor family with a pyrin domain, which is crucial in the innate immune defense against T. gondii. Research has shown that resveratrol (RSV) prevents lung damage caused by this infection by inhibiting the T. gondii-derived heat shock protein 70/TLR4/NF-κB pathway, thus reducing the macrophage-driven inflammatory response. However, it should be mentioned that the participation of NLRP3 inflammasome in the immune response to the lung injuries caused by T. gondii infections is not entirely clear. PURPOSE: This study aims to clarify how RSV ameliorates lung damage triggered by Toxoplasma gondii infection, with a particular focus on the pathway involving TLR4, NF-κB, and the NLRP3 inflammasome. METHODS: Both in vitro and in vivo models of infection were developed by employing the RH strain of T. gondii in BALB/c mice and RAW 264.7 macrophage cell lines. The action mechanism of RSV was explored using techniques such as molecular docking, surface plasmon resonance, ELISA, Western blot, co-immunoprecipitation, and immunofluorescence staining. RESULTS: Findings indicate that the suppression of TLR4 or NF-κB impacts the levels of proteins associated with the NLRP3 inflammasome pathway. Additionally, a significant affinity for binding between RSV and NLRP3 was observed. Treatment with RSV led to a marked reduction in the activation and formation of the NLRP3 inflammasome within lung tissues and RAW 264.7 cells, alongside a decrease in IL-1ß concentrations in the bronchoalveolar lavage fluid. These outcomes align with those seen when using the NLRP3 inhibitor CY-09. Moreover, the application of CY-09 prior to RSV negated the latter's anti-inflammatory properties. CONCLUSION: Considering insights from previous research alongside the outcomes of the current investigation, it appears that the TLR4/NF-κB/NLRP3 signaling pathway emerges as a promising target for immunomodulation to alleviate lung injury from T. gondii infection. The evidence gathered in this study lays the groundwork for the continued exploration and potential future clinical deployment of RSV as a therapeutic agent with anti-Toxoplasma properties and the capability to modulate the inflammatory response.
Assuntos
Inflamassomos , Camundongos Endogâmicos BALB C , NF-kappa B , Proteína 3 que Contém Domínio de Pirina da Família NLR , Pneumonia , Resveratrol , Receptor 4 Toll-Like , Toxoplasma , Resveratrol/farmacologia , Animais , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Camundongos , Inflamassomos/efeitos dos fármacos , Inflamassomos/metabolismo , Células RAW 264.7 , Receptor 4 Toll-Like/metabolismo , Pneumonia/tratamento farmacológico , Pneumonia/parasitologia , Toxoplasma/efeitos dos fármacos , NF-kappa B/metabolismo , Toxoplasmose/tratamento farmacológico , Pulmão/efeitos dos fármacos , Pulmão/parasitologia , Simulação de Acoplamento Molecular , Feminino , Transdução de Sinais/efeitos dos fármacos , Macrófagos/efeitos dos fármacosRESUMO
Toxoplasma gondii (T. gondii)-derived heat shock protein 70 (T.g.HSP70) is a toxic protein that downregulates host defense responses against T. gondii infection. T.g.HSP70 was proven to induce fatal anaphylaxis in T. gondii infected mice through cytosolic phospholipase A2 (cPLA2) activated-platelet-activating factor (PAF) production via Toll-like receptor 4 (TLR4)-mediated signaling. In this study, we investigated the effect of arctiin (ARC; a major lignan compound of Fructus arctii) on allergic liver injury using T.g.HSP70-stimulated murine liver cell line (NCTC 1469) and a mouse model of T. gondii infection. Localized surface plasmon resonance, ELISA, western blotting, co-immunoprecipitation, and immunofluorescence were used to investigate the underlying mechanisms of action of ARC on T. gondii-induced allergic acute liver injury. The results showed that ARC suppressed the T.g.HSP70-induced allergic liver injury in a dose-dependent manner. ARC could directly bind to T.g.HSP70 or TLR4, interfering with the interaction between these two factors, and inhibiting activation of the TLR4/mitogen-activated protein kinase/nuclear factor-kappa B signaling, thereby inhibiting the overproduction of cPLA2, PAF, and interferon-γ. This result suggested that ARC ameliorates T.g.HSP70-induced allergic acute liver injury by disrupting the TLR4-mediated activation of inflammatory mediators, providing a theoretical basis for ARC therapy to improve T.g.HSP70-induced allergic liver injury.
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Toxoplasma , Toxoplasmose , Animais , Camundongos , Toxoplasma/metabolismo , Receptor 4 Toll-Like/metabolismo , Fator de Ativação de Plaquetas , Toxoplasmose/tratamento farmacológico , Proteínas de Choque Térmico HSP70/metabolismo , Fígado/metabolismo , Fosfolipases/metabolismoRESUMO
Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan parasite that causes pulmonary toxoplasmosis, although its pathogenesis is incompletely understood. There is no cure for toxoplasmosis. Coixol, a plant polyphenol extracted from coix seeds, has a variety of biological activities. However, the effects of coixol on T. gondii infection have not been clarified. In this study, we infected a mouse macrophage cell line (RAW 264.7) and BALB/c mice with the T. gondii RH strain to establish infection models in vitro and in vivo, respectively, to explore protective effects and potential mechanisms of coixol on lung injury caused by T. gondii infection. Anti-T. gondii effects and underlying anti-inflammatory mechanisms of coixol were investigated by real-time quantitative PCR, molecular docking, localized surface plasmon resonance, co-immunoprecipitation, enzyme-linked immunosorbent assay, western blotting, and immunofluorescence microscopy. The results show that coixol inhibits T. gondii loads and T. gondii-derived heat shock protein 70 (T.g.HSP70) expression. Moreover, coixol reduced inflammatory cell recruitment and infiltration, and ameliorated pathological lung injury induced by T. gondii infection. Coixol can directly bind T.g.HSP70 or Toll-like receptor 4 (TLR4) to disrupt their interaction. Coixol prevented overexpression of inducible nitric oxide synthase, tumor necrosis factor-α, and high mobility group box 1 by inhibiting activation of the TLR4/nuclear factor (NF)-κB signaling pathway, consistent with effects of the TLR4 inhibitor CLI-095. These results indicate that coixol improves T. gondii infection-induced lung injury by interfering with T.g.HSP70-mediated TLR4/NF-κB signaling. Altogether, these findings suggest that coixol is a promising effective lead compound for the treatment of toxoplasmosis.
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Lesão Pulmonar , Toxoplasma , Toxoplasmose , Animais , Camundongos , Toxoplasma/metabolismo , NF-kappa B/metabolismo , Receptor 4 Toll-Like/metabolismo , Lesão Pulmonar/tratamento farmacológico , Simulação de Acoplamento Molecular , Toxoplasmose/tratamento farmacológico , Transdução de Sinais , Proteínas de Choque Térmico HSP70/metabolismoRESUMO
BACKGROUND: Toxoplasma gondii is an opportunistic protozoan that can infect host to cause toxoplasmosis. We have previously reported that resveratrol (RSV) has protective effects against liver damage in T. gondii infected mice. However, the effect of RSV on lung injury caused by T. gondii infection and its mechanism of action remain unclear. PURPOSE: In this work, we studied the protective effects of RSV on lung injury caused by T. gondii infection and explored the underlying mechanism. METHODS: Molecular docking and localized surface plasmon resonance assay were used to detect the molecular interactions between RSV and target proteins. In vitro, the anti-T. gondii effects and potential anti-inflammatory mechanisms of RSV were investigated by quantitative competitive-PCR, RT-PCR, ELISA, Western blotting and immunofluorescence using RAW 264.7 cells infected with tachyzoites of T. gondii RH strain. In vivo, the effects of RSV on lung injury caused by T. gondii infection were assessed by observing pathological changes and the expression of inflammatory factors of lung. RESULTS: RSV inhibited T. gondii loads and T. gondii-derived heat shock protein 70 (T.g.HSP70) expression in RAW 264.7 cells and lung tissues. Moreover, RSV interacts with T.g.HSP70 and toll-like receptor 4 (TLR4), respectively, and interferes with the interaction between T.g.HSP70 and TLR4. It also inhibited the overproduction of inducible nitric oxide synthase, TNF-α and high mobility group protein 1 (HMGB1) by down-regulating TLR4/nuclear factor kappa B (NF-κB) signaling pathway, which is consistent with the effect of TLR4 inhibitor CLI-095. In vivo, RSV improved the pathological lung damage produced by T. gondii infection, as well as decreased the number of inflammatory cells in bronchoalveolar lavage fluid and the release of HMGB1 and TNF-α. CONCLUSION: These findings indicate that RSV can inhibit the proliferation of T. gondii and T.g.HSP70 expression both in vitro and in vivo. RSV can inhibit excessive inflammatory response by intervening T.g.HSP70 and HMGB1 mediated TLR4/NF-κB signaling pathway activation, thereby ameliorating lung injury caused by T. gondii infection. The present study provides new data that may be useful for the development of RSV as a new agent for the treatment of lung damage caused by T. gondii infection.
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Proteína HMGB1 , Lesão Pulmonar , Toxoplasma , Animais , Camundongos , Toxoplasma/metabolismo , Receptor 4 Toll-Like/metabolismo , Proteína HMGB1/metabolismo , Resveratrol/farmacologia , NF-kappa B/metabolismo , Lesão Pulmonar/tratamento farmacológico , Fator de Necrose Tumoral alfa , Simulação de Acoplamento Molecular , Proteínas de Choque Térmico HSP70RESUMO
BACKGROUND: Toxoplasma gondii (T. gondii) is a neurotropic obligate intracellular parasite that can activate microglial and promote neuronal apoptosis, leading to central nervous system diseases. The NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome signaling complex plays a key role in inducing neuroinflammation. Our previous studies have found that ginsenoside Rh2 (GRh2) inhibits T. gondii infection-induced microglial activation and neuroinflammation by downregulating the Toll-like receptor 4/nuclear factor-kappa B signaling pathway. However, whether GRh2 reduces T. gondii infection-induced neuronal injury through actions on microglial NLRP3 inflammasome signaling has not yet been clarified. METHODS: In this study, we employed T. gondii RH strain to establish in vitro and in vivo infection models in BV2 microglia cell line and BALB/c mice. Molecular docking, localized surface plasmon resonance assay, quantitative competitive-PCR, ELISA, western blotting, flow cytometric analysis, and immunofluorescence were performed. RESULTS: Our results showed that GRh2 alleviated neuropathological damage and neuronal apoptosis in cortical tissue of T. gondii-infected mice. GRh2 and CY-09 (an inhibitor of NLRP3) exhibited potent anti-T. gondii effects through binding T. gondii calcium-dependent protein kinase 1 (TgCDPK1). GRh2 decreased Iba-1 (a specific microglial marker) and NLRP3 inflammasome signaling pathway-related protein expression by binding NLRP3. Co-culture of microglia/primary cortical neurons revealed that T. gondii-induced microglial activation caused neuronal apoptosis, but GRh2 reduced this effect, consistent with the effects of CY-09. CONCLUSION: Taken together, our results show that GRh2 has a protective effect against T. gondii infection-induced neuronal injury by binding TgCDPK1 and NLRP3 to inhibit NLRP3 inflammasome signaling pathway in microglia.
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Toxoplasma , Toxoplasmose , Animais , Camundongos , Inflamassomos/metabolismo , Microglia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Receptor 4 Toll-Like/metabolismo , Simulação de Acoplamento Molecular , Toxoplasma/metabolismo , Transdução de Sinais , Camundongos Endogâmicos BALB C , Proteínas NLR/metabolismo , Neurônios/metabolismoRESUMO
BACKGROUND: Maternal Toxoplasma gondii (T. gondii) infection during pregnancy has been associated with various mental illnesses in the offspring. Ginsenoside Rh2 (GRh2) is a major bioactive compound obtained from ginseng that has an anti-T. gondii effect and attenuates microglial activation through toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) signaling pathway. GRh2 also alleviated tumor-associated or lipopolysaccharide-induced depression. However, the effects and potential mechanisms of GRh2 on depression-like behavior in mouse offspring caused by maternal T. gondii infection during pregnancy have not been investigated. METHODS: We examined GRh2 effects on the depression-like behavior in mouse offspring, caused by maternal T. gondii infection during pregnancy, by measuring depression-like behaviors and assaying parameters at the neuronal and molecular level. RESULTS: We showed that GRh2 significantly improved behavioral measures: sucrose consumption, forced swim time and tail suspended immobility time of their offspring. These corresponded with increased tissue concentrations of 5-hydroxytryptamine and dopamine, and attenuated indoleamine 2,3-dioxygenase or enhanced tyrosine hydroxylase expression in the prefrontal cortex. GRh2 ameliorated neuronal damage in the prefrontal cortex. Molecular docking results revealed that GRh2 binds strongly to both TLR4 and high mobility group box 1 (HMGB1). CONCLUSION: This study demonstrated that GRh2 ameliorated the depression-like behavior in mouse offspring of maternal T. gondii infection during pregnancy by attenuating the excessive activation of microglia and neuroinflammation through the HMGB1/TLR4/NF-κB signaling pathway. It suggests that GRh2 could be considered a potential therapy in preventing and treating psychiatric disorders in the offspring mice of mothers with prenatal exposure to T. gondii infection.
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Toxoplasma gondii (T. gondii) is a neurotropic protozoan parasite, which can cause mental and behavioural disorders. The present study aimed to elucidate the effects and underlying molecular mechanisms of sertraline (SERT) on T. gondii-induced depression-like behaviours. In the present study, a mouse model and a microglial cell line (BV2 cells) model were established by infecting with the T. gondii RH strain. In in vivo and in vitro experiments, the underlying molecular mechanisms of SERT in inhibiting depression-like behaviours and cellular perturbations caused by T. gondii infection were investigated in the mouse brain and BV2 cells. The administration of SERT significantly ameliorated depression-like behaviours in T. gondii-infected mice. Furthermore, SERT inhibited T. gondii proliferation. Treatment with SERT significantly inhibited the activation of microglia and decreased levels of pro-inflammatory cytokines such as tumour necrosis factor-alpha, and interferon-gamma, by down-regulating tumour necrosis factor receptor 1/nuclear factor-kappa B signalling pathway, thereby ameliorating the depression-like behaviours induced by T. gondii infection. Our study provides insight into the underlying molecular mechanisms of the newly discovered role of SERT against T. gondii-induced depression-like behaviours.
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Toxoplasma , Toxoplasmose , Animais , Depressão/tratamento farmacológico , Camundongos , Microglia/metabolismo , Microglia/parasitologia , Sertralina/metabolismo , Sertralina/farmacologia , Toxoplasma/fisiologia , Toxoplasmose/tratamento farmacológico , Toxoplasmose/metabolismoRESUMO
Toxoplasma gondii (T. gondii) is an obligate intracellular parasite that can cause liver diseases in the host, including hepatitis and hepatomegaly. High mobility group box 1 (HMGB1) is the main inflammatory mediator causing cell injury or necrosis. HMGB1 binds to toll like receptor 4 (TLR4), then activates the nuclear factor-κB (NF-κB) signaling pathway, which promotes the release of inflammatory factors. Our previous studies showed that HMGB1 mediated TLR4/NF-κB signaling pathway plays an important role in liver injury induced by T. gondii infection. Resveratrol (RSV) is a small polyphenol, which has anti-inflammatory, anti-cancer, anti-T. gondii effect. However, the effect of RSV on liver injury caused by T. gondii infection is unclear. This study used the RH strain tachyzoites of T. gondii to infect murine liver line, NCTC-1469 cells to establish an in vitro model and acute infection of mice for the in vivo model to explore the protective effect of RSV on liver injury induced by T. gondii infection. The results showed that RSV inhibited the proliferation of T. gondii in the liver, reduced the alanine aminotransferase/aspartate aminotransferase levels and pathological liver damage. Additionally, RSV inhibited the production of tumor necrosis factor-α, inducible nitric oxide synthase and HMGB1 by interfering with the TLR4/NF-κB signaling pathway. These results indicate that RSV can protect liver injury caused by T. gondii infection by intervening in the HMGB1/TLR4/NF-κB signaling pathway. This study will provide a theoretical basis for RSV treatment of T. gondii infection induced liver injury.
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Hepatite Animal/prevenção & controle , Fígado/efeitos dos fármacos , Resveratrol/farmacologia , Toxoplasmose/complicações , Animais , Linhagem Celular , Modelos Animais de Doenças , Feminino , Proteína HMGB1/metabolismo , Hepatite Animal/imunologia , Hepatite Animal/parasitologia , Hepatite Animal/patologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/imunologia , Hepatócitos/patologia , Humanos , Fígado/citologia , Fígado/imunologia , Fígado/patologia , Camundongos , NF-kappa B/metabolismo , Resveratrol/uso terapêutico , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Receptor 4 Toll-Like/metabolismo , Toxoplasmose/tratamento farmacológico , Toxoplasmose/imunologia , Toxoplasmose/parasitologiaRESUMO
In the title coordinaltion polymer, [Cd(C(8)H(4)O(4))(C(8)H(7)N(3))(2)](n), the Cd(II) atom, lying on a twofold rotation axis, is six-coordinated by two carboxyl-ate O atoms from two benzene-1,3-dicarboxyl-ate (m-BDC) ligands and four N atoms from two chelating 2-(2-pyrid-yl)imidazole mol-ecules, forming a slightly distorted octa-hedral geometry. The m-BDC ligand is located over a twofold rotation axis. The Cd(II) atoms are bridged by the m-BDC ligands, leading to a wave-shaped chain structure along [010]. N-Hâ¯O hydrogen bonds connect the chains.