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1.
Acta Pharmacol Sin ; 2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376811

RESUMO

Monosodium urate (MSU) crystals, the etiological agent of gout, are formed in joints and periarticular tissues due to long-lasting hyperuricemia. Although MSU crystal-triggered NLRP3 inflammasome activation and interleukin 1ß (IL-1ß) release are known to have key roles in gouty arthritis, recent studies revealed that MSU crystal-induced necrosis also plays a critical role in this process. However, it remains unknown what forms of necrosis have been induced and whether combined cell death inhibitors can block such necrosis. Here, we showed that MSU crystal-induced necrosis in murine macrophages was not dependent on NLRP3 inflammasome activation, as neither genetic deletion nor pharmacological blockade of the NLRP3 pathway inhibited the necrosis. Although many cell death pathways (such as ferroptosis and pyroptosis) inhibitors or reactive oxygen species inhibitors did not have any suppressive effects, necroptosis pathway inhibitors GSK'872 (RIPK3 inhibitor), and GW806742X (MLKL inhibitor) dose-dependently inhibited MSU crystal-induced necrosis. Moreover, a triple combination of GSK'872, GW806742X, and IDN-6556 (pan-caspase inhibitor) displayed enhanced inhibition of the necrosis, which was further fortified by the addition of MCC950 (NLRP3 inhibitor), suggesting that multiple cell death pathways might have been triggered by MSU crystals. Baicalin, a previously identified inhibitor of NLRP3, inhibited MSU crystal-induced inflammasome activation and suppressed the necrosis in macrophages. Besides, baicalin gavage significantly ameliorated MSU crystal-induced peritonitis in mice. Altogether, our data indicate that MSU crystals induce NLRP3-independent necrosis, which can be inhibited by combined inhibitors for multiple signaling pathways, highlighting a new avenue for the treatment of gouty arthritis.

2.
Inflammation ; 44(4): 1229-1245, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34009550

RESUMO

The NLRP3 inflammasome is a multi-molecular complex that acts as a molecular platform to mediate caspase-1 activation, leading to IL-1ß/IL-18 maturation and release in cells stimulated by various pathogen-associated molecular patterns (PAMPs) or damage-associated molecular patterns (DAMPs). This inflammasome plays an important role in the innate immunity as its activation can further promote the occurrence of inflammation, enhance the ability of host to remove pathogens, and thus facilitate the repair of injured tissues. But if the inflammasome activation is dysregulated, it will cause the development of various inflammatory diseases and metabolic disorders. Therefore, under normal conditions, the activation of inflammasome is tightly regulated by various positive and negative signaling pathways to respond to the stimuli without damaging the host itself while maintaining homeostasis. In this review, we summarize recent advances in the major signaling pathways (including TLRs, MAPK, mTOR, autophagy, PKA, AMPK, and IFNR) that regulate NLRP3 inflammasome activation, providing a brief view of the molecular network that regulates this inflammasome as a theoretical basis for therapeutic intervention of NLRP3 dysregulation-related diseases.

3.
Methods Mol Biol ; 2321: 43-51, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34048006

RESUMO

Mouse models of bacterial sepsis are widely used in research to investigate the underlying molecular mechanisms of sepsis and to develop clinically useful therapeutic regimens. Three commonly used mouse sepsis models include (a) injection of bacterial endotoxin, (b) infusion of cultured bacteria, and (c) cecal ligation and puncture. Here we describe the induction of bacterial sepsis in mice by intraperitoneal injection of cultured live Escherichia coli cells. The severity of the sepsis can be regulated by the number of E. coli cells injected into the peritoneal cavity of mice.


Assuntos
Escherichia coli/crescimento & desenvolvimento , Sepse/microbiologia , Animais , Ceco/microbiologia , Modelos Animais de Doenças , Endotoxinas/administração & dosagem , Injeções Intraperitoneais/métodos , Ligadura/métodos , Camundongos , Camundongos Endogâmicos C57BL , Cavidade Peritoneal/microbiologia , Punções/métodos
4.
Front Immunol ; 12: 632606, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33679781

RESUMO

Taraxasterol (TAS) is an active ingredient of Dandelion (Taraxacum mongolicum Hand. -Mazz.), a medicinal plant that has long been used in China for treatment of inflammatory disorders. But the underlying mechanism for its therapeutic effects on inflammatory disorders is not completely clear. Inflammasome activation is a critical step of innate immune response to infection and aseptic inflammation. Among the various types of inflammasome sensors that has been reported, NLR family pyrin domain containing 3 (NLRP3) is implicated in various inflammatory diseases and therefore has been most extensively studied. In this study, we aimed to explore whether TAS could influence NLPR3 inflammasome activation in macrophages. The results showed that TAS dose-dependently suppressed the activation of caspase-1 in lipopolysaccharide (LPS)-primed murine primary macrophages upon nigericin treatment, resulting in reduced mature interleukin-1ß (IL-1ß) release and gasdermin D (GSDMD) cleavage. TAS greatly reduced ASC speck formation upon the stimulation of nigericin or extracellular ATP. Consistent with reduced cleavage of GSDMD, nigericin-induced pyroptosis was alleviated by TAS. Interestingly, TAS time-dependently suppressed the mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) and mTORC2 signaling induced by LPS priming. Like TAS, both INK-128 (inhibiting both mTORC1 and mTORC2) and rapamycin (inhibiting mTORC1 only) also inhibited NLRP3 inflammasome activation, though their effects on mTOR signaling were different. Moreover, TAS treatment alleviated mitochondrial damage by nigericin and improved mouse survival from bacterial infection, accompanied by reduced IL-1ß levels in vivo. Collectively, by inhibiting the NLRP3 inflammasome activation, TAS displayed anti-inflammatory effects likely through regulation of the mTOR signaling in macrophages, highlighting a potential action mechanism for the anti-inflammatory activity of Dandelion in treating inflammation-related disorders, which warrants further clinical investigation.


Assuntos
Inflamassomos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Piroptose/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Esteróis/farmacologia , Serina-Treonina Quinases TOR/metabolismo , Triterpenos/farmacologia , Animais , Anti-Inflamatórios/farmacologia , Infecções Bacterianas/tratamento farmacológico , Proteínas Adaptadoras de Sinalização CARD/metabolismo , Inflamassomos/metabolismo , Lipopolissacarídeos/farmacologia , Macrófagos/metabolismo , Macrófagos/patologia , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Nigericina/farmacologia , Esteróis/uso terapêutico , Análise de Sobrevida , Triterpenos/uso terapêutico
5.
Int Immunopharmacol ; 90: 107242, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33307514

RESUMO

Colonic patches, the counterparts of Peyer's patches in the small intestine, are dynamically regulated lymphoid tissues in the colon that have an important role in defensing against microbial infections. Berberine is an isoquinoline alkaloid extracted from medicinal herbs including Rhizoma coptidis and has long been used for the treatment of infectious gastroenteritis, but its impact on the colonic lymphoid tissues (such as colonic patches) is unknown. In this study, we aimed to investigate whether berberine had any influences on the colonic patches in mice with bacterial infection. The results showed that oral berberine administration in bacterial infected mice substantially enhanced the hypertrophy of colonic patches, which usually possessed the features of two large B-cell follicles with a separate T-cell area. Moreover, the colonic patches displayed follicular dendritic cell networks within the B-cell follicles, indicative of mature colonic patches containing germinal centers. Concomitant with enlarged colonic patches, the cultured colon of infected mice treated with berberine secreted significantly higher levels of interleukin-1ß (IL-1ß), IL-6, TNF-α, and CCL-2, while NLRP3 inhibitor MMC950 or knockout of NLRP3 gene abrogated berberine-induced hypertrophy of colonic patches, suggesting the involvement of the NLRP3 signaling pathway in this process. Functionally, oral administration of berberine ameliorated liver inflammation and improved formed feces in the colon. Altogether, these results indicated that berberine was able to augment the hypertrophy of colonic patches in mice with bacterial infection probably through enhancing local inflammatory responses in the colon.


Assuntos
Infecções Bacterianas/patologia , Berberina/uso terapêutico , Colo/efeitos dos fármacos , Tecido Linfoide/efeitos dos fármacos , Doenças Peritoneais/patologia , Animais , Linfócitos B/efeitos dos fármacos , Infecções Bacterianas/tratamento farmacológico , Infecções Bacterianas/metabolismo , Colo/crescimento & desenvolvimento , Colo/patologia , Citocinas/metabolismo , Células Dendríticas/efeitos dos fármacos , Feminino , Gastroenterite/tratamento farmacológico , Tecido Linfoide/crescimento & desenvolvimento , Tecido Linfoide/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidores , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Doenças Peritoneais/tratamento farmacológico , Doenças Peritoneais/metabolismo , Linfócitos T/efeitos dos fármacos
6.
Cell Prolif ; 52(5): e12663, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31347748

RESUMO

OBJECTIVE: Induction of secondary necrosis/pyroptosis contributes to the toxicity of chemotherapeutic drugs, in which gasdermin E (GSDME) plays critical roles. This study aimed to explore whether GSDME is involved in mediating the cytotoxic effects of cisplatin and doxorubicin on mouse macrophages. METHODS: RAW 264.7 cells and bone marrow-derived macrophages (BMDMs) were treated with cisplatin or doxorubicin. Propidium iodide staining was used to assay necrosis, and immunoblotting was performed to detect protein expression. GSDME was knocked down by using small interfering RNA. Mice were injected intraperitoneally to evaluate toxicity to macrophages in vivo. Flow cytometry and immunofluorescence microscopy were adopted to analyse phenotypes of peritoneal cells. Cytokine levels were assayed by cytometric bead array. RESULTS: Both cisplatin and doxorubicin dose-dependently induced necrosis in mouse RAW 264.7 macrophages and BMDMs. Accompanying this, multiple caspases were activated, concomitant with the cleavage of poly (ADP-ribose) polymerase. Consistent with caspase-3 activation, GSDME was cleaved to generate its N-terminal fragment (GSDME-NT), thus leading to secondary necrosis/pyroptosis. Inhibition of caspase-3 significantly attenuated the generation of GSDME-NT concurrently with decreased necrosis in macrophages. GSDME knockdown also evidently decreased the necrosis in RAW 264.7 and BMDMs. Besides, cisplatin administration depleted peritoneal macrophages in mice, which was associated with caspase-3 activation and GSDME-NT generation. Consistent with the macrophage depletion, cisplatin administration significantly decreased survival of mice with bacterial infection. CONCLUSION: Chemotherapeutic cisplatin and doxorubicin exerted their cytotoxicity on macrophages partly by inducing caspase-3/GSDME-mediated secondary necrosis.


Assuntos
Caspase 3/metabolismo , Cisplatino/farmacologia , Doxorrubicina/farmacologia , Piroptose/efeitos dos fármacos , Receptores de Estrogênio/metabolismo , Animais , Apoptose/efeitos dos fármacos , Citocinas/metabolismo , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/mortalidade , Infecções por Escherichia coli/patologia , Infecções por Escherichia coli/veterinária , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Células RAW 264.7 , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Receptores de Estrogênio/antagonistas & inibidores , Receptores de Estrogênio/genética , Taxa de Sobrevida
7.
Apoptosis ; 24(9-10): 703-717, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31175486

RESUMO

ATP acts as a canonical activator to induce NLRP3 (NOD-like receptor family, pyrin domain containing 3) inflammasome activation in macrophages, leading to caspase-1/gasdermin D (GSDMD)-mediated pyroptosis. It remains unclear whether ATP can induce pyroptosis in macrophages when the NLRP3 pathway is blocked by pathogenic infection. In this study, we used cellular models to mimic such blockade of NLRP3 activation: bone marrow-derived macrophages (BMDMs) treated with NLRP3-specific inhibitor MCC950 and RAW264.7 cells deficient in ASC (apoptosis-associated speck-like protein containing a caspase recruitment domain) expression. The results showed that ATP treatment induced lytic cell death morphologically resembling canonical pyroptosis in both MCC950-treated BMDMs and RAW264.7 cells, but did not cause the activation of caspase-1 (by detecting caspase-1p10 and mature interleukin-1ß) and cleavage of GSDMD. Instead, both apoptotic initiator (caspase-8 and -9) and executioner (caspase-3 and -7) caspases were evidently activated and gasdermin E (GSDME) was cleaved to generate its N-terminal fragment (GSDME-NT) which executes pyroptosis. The GSDME-NT production and lytic cell death induced by ATP were diminished by caspase-3 inhibitor. In BMDMs without MCC950 treatment, ATP induced the formation of ASC specks which were co-localized with caspase-8; with MCC950 treatment, however, ATP did not induced the formation of ASC specks. In RAW264.7 cells, knockdown of GSDME by small interfering RNA attenuated ATP-induced lytic cell death and HMGB1 release into culture supernatants. Collectively, our results indicate that ATP induces pyroptosis in macrophages through the caspase-3/GSDME axis when the canonical NLRP3 pathway is blocked, suggestive of an alternative mechanism for combating against pathogen evasion.


Assuntos
Trifosfato de Adenosina/farmacologia , Caspase 3/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Proteínas de Neoplasias/metabolismo , Piroptose/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Animais , Caspase 1/metabolismo , Caspase 8/metabolismo , Caspases/metabolismo , Inflamassomos/metabolismo , Macrófagos/metabolismo , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Células RAW 264.7 , Interferência de RNA
8.
Front Pharmacol ; 10: 290, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30971927

RESUMO

Evodiamine is a major ingredient of the plant Evodia rutaecarpa, which has long been used for treating infection-related diseases including diarrhea, beriberi and oral ulcer, but the underlying mechanism is unclear. Here we aimed to explore whether evodiamine influenced NLRP3 (NLR family, pyrin containing domain 3) inflammasome activation in macrophages, which is a critical mechanism for defending the host against pathogenic infections. We uncovered that evodiamine dose-dependently enhanced NLRP3 inflammasome activation in lipopolysaccharide-primed macrophages, as indicated by increased interleukin (IL)-1ß production and caspase-1 cleavage, accompanied by increased ASC speck formation and pyroptosis. Mechanistically, evodiamine induced acetylation of α-tubulin around the microtubule organization center (indicated by γ-tubulin) in lipopolysaccharide-primed macrophages. Such evodiamine-mediated increases in NLRP3 activation and pyroptosis were attenuated by activators of α-tubulin deacetylase, resveratrol and NAD+, or dynein-specific inhibitor ciliobrevin A. Small interfering RNA knockdown of αTAT1 (the gene encoding α-tubulin N-acetyltransferase) expression, which reduced α-tubulin acetylation, also diminished evodiamine-mediated augmentation of NLRP3 activation and pyroptosis. Evodiamine also enhanced NLRP3-mediated production of IL-1ß and neutrophil recruitment in vivo. Moreover, evodiamine administration evidently improved survival of mice with lethal bacterial infection, accompanied by increased production of IL-1ß and interferon-γ, decreased bacterial load, and dampened liver inflammation. Resveratrol treatment reversed evodiamine-induced increases of IL-1ß and interferon-γ, and decreased bacterial clearance in mice. Collectively, our results indicated that evodiamine augmented the NLRP3 inflammasome activation through inducing α-tubulin acetylation, thereby conferring intensified innate immunity against bacterial infection.

9.
Front Immunol ; 10: 72, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30761140

RESUMO

Microtubules play critical roles in regulating the activation of NLRP3 inflammasome and microtubule-destabilizing agents such as colchicine have been shown to suppress the activation of this inflammasome. However, it remains largely unknown whether paclitaxel, a microtubule-stabilizing agent being used in cancer therapy, has any influences on NLRP3 inflammasome activation. Here we showed that paclitaxel pre-treatment greatly enhanced ATP- or nigericin-induced NLRP3 inflammasome activation as indicated by increased release of cleaved caspase-1 and mature IL-1ß, enhanced formation of ASC speck, and increased gasdermin D cleavage and pyroptosis. Paclitaxel time- and dose-dependently induced α-tubulin acetylation in LPS-primed murine and human macrophages and further increased ATP- or nigericin-induced α-tubulin acetylation. Such increased α-tubulin acetylation was significantly suppressed either by resveratrol or NAD+ (coenzyme required for deacetylase activity of SIRT2), or by genetic knockdown of MEC-17 (gene encoding α-tubulin acetyltransferase 1). Concurrently, the paclitaxel-mediated enhancement of NLRP3 inflammasome activation was significantly suppressed by resveratrol, NAD+, or MEC-17 knockdown, indicating the involvement of paclitaxel-induced α-tubulin acetylation in the augmentation of NLRP3 inflammasome activation. Similar to paclitaxel, epothilone B that is another microtubule-stabilizing agent also induced α-tubulin acetylation and increased NLRP3 inflammasome activation in macrophages in response to ATP treatment. Consistent with the in vitro results, intraperitoneal administration of paclitaxel significantly increased serum IL-1ß levels, reduced bacterial burden, dampened infiltration of inflammatory cells in the liver, and improved animal survival in a mouse model of bacterial infection. Collectively, our data indicate that paclitaxel potentiated NLRP3 inflammasome activation by inducing α-tubulin acetylation and thereby conferred enhanced antibacterial innate responses, suggesting its potential application against pathogenic infections beyond its use as a chemotherapeutic agent.


Assuntos
Imunidade Inata/efeitos dos fármacos , Inflamassomos/metabolismo , Macrófagos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Paclitaxel/farmacologia , Acetilação/efeitos dos fármacos , Acetiltransferases/genética , Animais , Infecções Bacterianas/imunologia , Linhagem Celular , Modelos Animais de Doenças , Epotilonas/farmacologia , Técnicas de Silenciamento de Genes , Humanos , Interleucina-1beta/sangue , Interleucina-1beta/metabolismo , Camundongos , Proteínas dos Microtúbulos/genética , Microtúbulos/efeitos dos fármacos , Microtúbulos/metabolismo , Nigericina/farmacologia , Paclitaxel/administração & dosagem , Piroptose/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Células THP-1 , Tubulina (Proteína)/metabolismo
10.
Apoptosis ; 24(3-4): 312-325, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30710195

RESUMO

Gasdermin E (GSDME) has an important role in inducing secondary necrosis/pyroptosis. Upon apoptotic stimulation, it can be cleaved by activated caspase-3 to generate its N-terminal fragment (GSDME-NT), which executes pyroptosis by perforating the plasma membrane. GSDME is expressed in many human lung cancers including A549 cells. Paclitaxel and cisplatin are two representative chemotherapeutic agents for lung cancers, which induce apoptosis via different action mechanisms. However, it remains unclear whether they can induce GSDME-mediated secondary necrosis/pyroptosis in lung A549 cancer cells. Here we showed that both paclitaxel and cisplatin evidently induced apoptosis in A549 cells as revealed by the activation of multiple apoptotic markers. Notably, some of the dying cells displayed characteristic morphology of secondary necrosis/pyroptosis, by blowing large bubbles from the cellular membrane accompanied by caspase-3 activation and GSDME-NT generation. But the ability of cisplatin to induce this phenomenon was much stronger than that of paclitaxel. Consistent with this, cisplatin triggered much higher activation of caspase-3 and generation of GSDME-NT than paclitaxel, suggesting that the levels of secondary necrosis/pyroptosis correlated with the levels of active caspase-3 and GSDME-NT. Supporting this, caspase-3 specific inhibitor (Ac-DEVD-CHO) suppressed cisplatin-induced GSDME-NT generation and concurrently reduced the secondary necrosis/pyroptosis. Besides, GSDME knockdown significantly inhibited cisplatin- but not paclitaxel-induced secondary necrosis/pyroptosis. These results indicated that cisplatin induced higher levels of secondary necrosis/pyroptosis in A549 cells than paclitaxel, suggesting that cisplatin may provide additional advantages in the treatment of lung cancers with high levels of GSDME expression.


Assuntos
Antineoplásicos/farmacologia , Caspase 3/metabolismo , Cisplatino/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Paclitaxel/farmacologia , Piroptose/efeitos dos fármacos , Receptores de Estrogênio/metabolismo , Células A549 , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Neoplasias Pulmonares/metabolismo , Necrose/tratamento farmacológico , Necrose/metabolismo
11.
Front Immunol ; 8: 1409, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29163487

RESUMO

The flavonoid baicalin has been reported to possess potent anti-inflammatory activities by suppressing inflammatory signaling pathways. However, whether baicalin can suppress the activation of NOD-like receptor (NLR) family, pyrin containing domain 3 (NLRP3) inflammasome in macrophages is largely unknown. Here, we showed that baicalin treatment dose-dependently inhibited adenosine triphosphate (ATP) or nigericin-induced NLRP3 inflammasome activation, as revealed by the decreased release of mature interleukin (IL)-1ß, active caspase-1p10, and high-mobility group box-1 protein from lipopolysaccharide (LPS)-primed bone marrow-derived macrophages. The formation of ASC specks, a critical marker of NLRP3 inflammasome assembly, was robustly inhibited by baicalin in the macrophages upon ATP or nigericin stimulation. All these inhibitory effects of baicalin could be partly reversed by MDL12330A or H89, both of which are inhibitors of the protein kinase A (PKA) signaling pathway. Consistent with this, baicalin strongly enhanced PKA-mediated phosphorylation of NLRP3, which has been suggested to prevent ASC recruitment into the inflammasome. Of note, the PKA inhibitor H89 could block baicalin-induced NLRP3 phosphorylation on PKA-specific sites, further supporting PKA's role in this process. In addition, we showed that when administered pre and post exposure to Escherichia coli infection baicalin treatment significantly improved mouse survival in bacterial sepsis. Baicalin administration also significantly reduced IL-1ß levels in the sera of bacterial infected mice. Altogether, our results revealed that baicalin inhibited NLRP3 inflammasome activation at least partly through augmenting PKA signaling, highlighting its therapeutic potential for the treatment of NLRP3-related inflammatory diseases.

12.
Oncotarget ; 8(1): 95-109, 2017 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-27980220

RESUMO

The isoquinoline alkaloid berberine possesses many pharmacological activities including antibacterial infection. Although the direct bactericidal effect of berberine has been documented, its influence on the antibacterial functions of macrophages is largely unknown. As inflammasome activation in macrophages is important for the defense against bacterial infection, we aimed to investigate the influence of berberine on inflammasome activation in murine macrophages. Our results showed that berberine significantly increased ATP-induced inflammasome activation as reflected by enhanced pyroptosis as well as increased release of caspase-1p10 and mature interleukin-1ß (IL-1ß) in macrophages. Such effects of berberine could be suppressed by AMP-activated protein kinase (AMPK) inhibitor compound C or by knockdown of AMPKα expression, indicating the involvement of AMPK signaling in this process. In line with increased IL-1ß release, the ability of macrophages to kill engulfed bacteria was also intensified by berberine. This was corroborated by the in vivo finding that the peritoneal live bacterial load was decreased by berberine treatment. Moreover, berberine administration significantly improved survival of bacterial infected mice, concomitant with increased IL-1ß levels and elevated neutrophil recruitment in the peritoneal cavity. Collectively, these data suggested that berberine could enhance bacterial killing by augmenting inflammasome activation in macrophages through AMPK signaling.


Assuntos
Trifosfato de Adenosina/metabolismo , Berberina/farmacologia , Inflamassomos/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/fisiologia , Trifosfato de Adenosina/farmacologia , Animais , Infecções Bacterianas/imunologia , Infecções Bacterianas/metabolismo , Infecções Bacterianas/microbiologia , Feminino , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/fisiologia , Camundongos , Viabilidade Microbiana/imunologia , Infiltração de Neutrófilos/imunologia , Neutrófilos/imunologia , Neutrófilos/metabolismo , Neutrófilos/microbiologia
13.
Front Immunol ; 8: 1919, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29354128

RESUMO

CPT-11 is a first-line chemotherapeutic agent for the treatment of colorectal cancer in clinic. Previous studies including ours have demonstrated that CPT-11 is, however, toxic to the intestinal epithelium and resident peritoneal macrophages. By interacting with B1 cells, the resident peritoneal macrophages play critical roles in the maintenance of gastrointestinal homeostasis. It remains therefore elusive whether these peritoneal innate immune cells could be rebuilt spontaneously or artificially after being impaired by CPT-11 administration. In this study, we found that mouse resident peritoneal macrophages, namely the large peritoneal macrophages (LPMs) with a CD11b+F4/80hiGATA6+ phenotype, and B1 (CD19+CD23-) cells were depleted by intraperitoneal (i.p.) CPT-11 treatment within 1 week, but reappeared from day 14 after CPT-11 treatment. However, the recovery processes of these innate immune cells were slow, as their counts could not be fully recovered even 2 months later, when compared with that of vehicle-treated control group. Interestingly, in the peritoneal cavity of the mice treated with CPT-11, the cell counts of LPMs and B1 cells were significantly increased after adoptive transfer with syngeneic peritoneal exudate cells (PECs) from healthy mice. Adoptive transfer with bone marrow cells also slightly increased, although not significantly, the cell counts of LPMs and B1 cells in CPT-11-treated mice. The survival rate of bacterial infected mice was significantly reduced by i.p. CPT-11 treatment in comparison with vehicle-treated or untreated control groups. Besides, oral administration of CPT-11 also had a delayed toxicity on the resident peritoneal macrophages. Our results suggest that CPT-11 has prolonged deleterious effects on peritoneal innate immune cells but adoptive transfer with PECs may accelerate their recovery processes, highlighting the potential of adoptive cell transfer as an avenue to counteract the adverse effects of this chemotherapeutic agent.

14.
Front Pharmacol ; 8: 975, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29375379

RESUMO

The NLRP3 inflammasome plays a critical role in mediating the innate immune defense against pathogenic infections, but aberrant activation of NLRP3 inflammasome has been linked to a variety of inflammatory diseases. Thus targeting the NLRP3 inflammasome represents a promising therapeutic for the treatment of such diseases. Scutellarin is a flavonoid isolated from Erigeron breviscapus (Vant.) Hand.-Mazz. and has been reported to exhibit potent anti-inflammatory activities, but the underlying mechanism is only partly understood. In this study, we aimed to investigate whether scutellarin could affect the activation of NLRP3 inflammasome in macrophages. The results showed that scutellarin dose-dependently reduced caspase-1 activation and decreased mature interleukin-1ß (IL-1ß) release in lipopolysaccharide (LPS)-primed macrophages upon ATP or nigericin stimulation, indicating that scutellarin inhibited NLRP3 inflammasome activation in macrophages. Consistent with this, scutellarin also suppressed pyroptotic cell death in LPS-primed macrophages treated with ATP or nigericin. ATP or nigericin-induced ASC speck formation and its oligomerization were blocked by scutellarin pre-treatment. Intriguingly, scutellarin augmented PKA-specific phosphorylation of NLRP3 in LPS-primed macrophages, which was completely blocked by selective PKA inhibitor H89, suggesting that PKA signaling had been involved in the action of scutellarin to suppress NLRP3 inflammasome activation. Supporting this, the inhibitory effect of scutellarin on NLRP3 inflammasome activation was completely counteracted by H89 or adenyl cyclase inhibitor MDL12330A. As NLRP3-dependent release of IL-1ß has a critical role in sepsis, the in vivo activity of scutellarin was assayed in a mouse model of bacterial sepsis, which was established by intraperitoneally injection of a lethal dose of viable Escherichia coli. Oral administration of scutellarin significantly improved the survival of mice with bacterial sepsis. In line with this, scutellarin treatment significantly reduced serum IL-1ß levels and attenuated the infiltration of inflammatory cells in the liver of E. coli-infected mice. These data indicated that scutellarin suppressed NLRP3 inflammasome activation in macrophages by augmenting PKA signaling, highlighting its potential therapeutic application for treating NLRP3-related inflammatory diseases.

15.
Front Immunol ; 7: 597, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28018360

RESUMO

Adenosine triphosphate (ATP) is released by bacteria and host cells during bacterial infection as well as sterile tissue injury, acting as an inducer of inflammasome activation. Previous studies have shown that ATP treatment leads to AMP-activated protein kinase (AMPK) activation. However, it is unclear whether AMPK signaling has been involved in the regulation of ATP-induced inflammasome activation and subsequent pyroptosis. In this study, we aimed to investigate this issue in lipopolysaccharide-activated murine macrophages. Our results showed that AMPK signaling was activated in murine macrophages upon ATP treatment, which was accompanied by inflammasome activation and pyroptosis as evidenced by rapid cell membrane rupture as well as mature interleukin (IL)-1ß and active caspase-1p10 release. The ATP-induced inflammasome activation and pyroptosis were markedly suppressed by an AMPK inhibitor compound C or small-interfering RNA-mediated knockdown of AMPKα, but could be greatly enhanced by metformin (a well-known AMPK agonist). Importantly, metformin administration increased the mortality of mice with bacterial sepsis, which was likely because metformin treatment enhanced the systemic inflammasome activation as indicated by elevated serum and hepatic IL-1ß levels. Collectively, these data indicated that the AMPK signaling positively regulated ATP-induced inflammasome activation and pyroptosis in macrophages, highlighting the possibility of AMPK-targeting therapies for inflammatory diseases involving inflammasome activation.

16.
Front Pharmacol ; 7: 390, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27812336

RESUMO

Piperine is a phytochemical present in black pepper (Piper nigrum Linn) and other related herbs, possessing a wide array of pharmacological activities including anti-inflammatory effects. Previously, we demonstrated that piperine has therapeutic effects on bacterial sepsis in mice, but the underlying mechanism has not been fully elucidated. In this study, we aimed to investigate the influences of piperine on pyroptosis in murine macrophages. The results showed that piperine dose-dependently inhibited ATP-induced pyroptosis, thereby suppressing interleukin-1ß (IL-1ß) or high mobility group box-1 protein (HMGB1) release in LPS-primed bone marrow-derived macrophages and J774A.1 cells. Accompanying this, ATP-induced AMP-activated protein kinase (AMPK) activation was greatly suppressed by piperine, whereas AMPK agonist metformin counteracted piperine's inhibitory effects on pyroptosis. Moreover, piperine administration greatly reduced both peritoneal and serum IL-1ß levels in the mouse model intraperitoneally infected with Escherichia coli, suggestive of suppressing systemic inflammation and pyroptosis. Our data indicated that piperine could protect macrophages from pyroptosis and reduced IL-1ß and HMGB1 release by suppressing ATP-induced AMPK activation, suggesting that piperine may become a potential therapeutic agent against bacterial sepsis.

17.
Toxicol Appl Pharmacol ; 292: 56-64, 2016 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-26765310

RESUMO

Gossypol, a polyphenolic compound isolated from cottonseeds, has been reported to possess many pharmacological activities, but whether it can influence inflammasome activation remains unclear. In this study, we found that in mouse macrophages, gossypol induced cell death characterized by rapid membrane rupture and robust release of HMGB1 and pro-caspase-11 comparable to ATP treatment, suggesting an induction of pyroptotic cell death. Unlike ATP, gossypol induced much low levels of mature interleukin-1ß (IL-1ß) secretion from mouse peritoneal macrophages primed with LPS, although it caused pro-IL-1ß release similar to that of ATP. Consistent with this, activated caspase-1 responsible for pro-IL-1ß maturation was undetectable in gossypol-treated peritoneal macrophages. Besides, RAW 264.7 cells lacking ASC expression and caspase-1 activation also underwent pyroptotic cell death upon gossypol treatment. In further support of pyroptosis induction, both pan-caspase inhibitor and caspase-1 subfamily inhibitor, but not caspase-3 inhibitor, could sharply suppress gossypol-induced cell death. Other canonical pyroptotic inhibitors, including potassium chloride and N-acetyl-l-cysteine, could suppress ATP-induced pyroptosis but failed to inhibit or even enhanced gossypol-induced cell death, whereas nonspecific pore-formation inhibitor glycine could attenuate this process, suggesting involvement of a non-canonical pathway. Of note, gossypol treatment eliminated thioglycollate-induced macrophages in the peritoneal cavity with recruitment of other leukocytes. Moreover, gossypol administration markedly decreased the survival of mice in a bacterial sepsis model. Collectively, these results suggested that gossypol induced pyroptosis in mouse macrophages via a non-canonical inflammasome pathway, which raises a concern for its in vivo cytotoxicity to macrophages.


Assuntos
Gossipol/toxicidade , Inflamassomos/metabolismo , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/metabolismo , Piroptose/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Animais , Morte Celular/efeitos dos fármacos , Morte Celular/fisiologia , Linhagem Celular , Relação Dose-Resposta a Droga , Camundongos , Camundongos Endogâmicos C57BL , Piroptose/fisiologia , Transdução de Sinais/fisiologia
18.
Sci Rep ; 6: 18987, 2016 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-26732172

RESUMO

Mammalian target of rapamycin (mTOR) is an attractive target for new anticancer drug development. We recently developed in silico models to distinguish mTOR inhibitors and non-inhibitors. In this study, we developed an integrated strategy for identifying new mTOR inhibitors using cascaded in silico screening models. With this strategy, fifteen new mTOR kinase inhibitors including four compounds with IC50 values below 10 µM were discovered. In particular, compound 17 exhibited potent anticancer activities against four tumor cell lines, including MCF-7, HeLa, MGC-803, and C6, with IC50 values of 1.90, 2.74, 3.50 and 11.05 µM. Furthermore, cellular studies and western blot analyses revealed that 17 induces cell death via apoptosis by targeting both mTORC1 and mTORC2 within cells and arrests the cell cycle of HeLa at the G1/G0-phase. Finally, multi-nanosecond explicit solvent simulations and MM/GBSA analyses were carried out to study the inhibitory mechanisms of 13, 17, and 40 for mTOR. The potent compounds presented here are worthy of further investigation.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Simulação por Computador , Descoberta de Drogas/métodos , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Ligantes , Modelos Moleculares , Estrutura Molecular , Ligação Proteica , Relação Quantitativa Estrutura-Atividade , Serina-Treonina Quinases TOR/metabolismo
19.
Apoptosis ; 21(2): 130-42, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26531131

RESUMO

CPT-11 (Irinotecan) is a first-line chemotherapeutic agent in clinic, but it may induce side effects including diarrhea and enteritis in patients. The underlying mechanism of CPT-11's intestinal toxicity is unclear. Peritoneal resident macrophages have been reported to be important for the maintenance of intestinal homeostasis. In this study, we evaluated the cytotoxic effects of CPT-11 on mouse peritoneal resident macrophages. CPT-11 was administered intraperitoneally to mice and their peritoneal exudate cells were isolated for evaluation. CPT-11 treatment strikingly decreased the ratio of F4/80(hi)MHCII(low) large peritoneal macrophages (LPMs), which are regarded as prenatally-originated peritoneal resident macrophages. Consistent with this, the transcription factor GATA6 specifically expressed in LPMs was barely detectable in the macrophages from CPT-11-treated mice, indicative of elimination of LPMs. Such elimination of LPMs was at least partly due to CPT-induced apoptosis in macrophages, because inhibition of apoptosis by caspase-3 inhibitor z-DEVD-fmk significantly diminished the loss of GATA6(+) LPMs. As GATA6 is a transcription factor that controls expression of multiple genes regulating peritoneal B-1 cell development and translocation, elimination of GATA6(+) LPMs led to a great reduction in B-1 cells in the peritoneal cavity after CPT-11 treatment. These results indicated that CPT-11-induced apoptosis contributed to the elimination of peritoneal resident macrophages, which might in turn impair the function of peritoneal B-1 cells in maintaining intestinal homeostasis. Our findings may at least partly explain why CPT-11 treatment in cancer patients induces diarrhea and enteritis, which may provide a novel avenue to prevent such side effects.


Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Apoptose/efeitos dos fármacos , Camptotecina/análogos & derivados , Macrófagos Peritoneais/fisiologia , Animais , Antineoplásicos Fitogênicos/efeitos adversos , Camptotecina/administração & dosagem , Camptotecina/efeitos adversos , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Enterite/induzido quimicamente , Feminino , Injeções Intraperitoneais , Irinotecano , Macrófagos Peritoneais/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Células RAW 264.7
20.
Oncotarget ; 6(32): 32468-83, 2015 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-26439699

RESUMO

Pepper, a daily-used seasoning for promoting appetite, is widely used in folk medicine for treating gastrointestinal diseases. Piperine is the major alkaloid in pepper and possesses a wide range of pharmacological activities. However, the mechanism for linking metabolic and medicinal activities of piperine remains unknown. Here we report that piperine robustly boosts mTORC1 activity by recruiting more system L1 amino acid transporter (SLC7A5/SLC3A2) to the cell membrane, thus promoting amino acid metabolism. Piperine-induced increase of mTORC1 activity in resident peritoneal macrophages (pMΦs) is correlated with enhanced production of IL-6 and TNF-α upon LPS stimulation. Such an enhancement of cytokine production could be abrogated by inhibitors of the mTOR signaling pathway, indicating mTOR's action in this process. Moreover, piperine treatment protected resident pMΦs from bacterium-induced apoptosis and disappearance, and increased their bacterial phagocytic ability. Consequently, piperine administration conferred mice resistance against bacterial infection and even sepsis. Our data highlight that piperine has the capacity to metabolically reprogram peritoneal resident macrophages to fortify their innate functions against bacterial infection.


Assuntos
Alcaloides/farmacologia , Aminoácidos/metabolismo , Antibacterianos/farmacologia , Benzodioxóis/farmacologia , Infecções por Escherichia coli/prevenção & controle , Escherichia coli/efeitos dos fármacos , Ativação de Macrófagos/efeitos dos fármacos , Macrófagos Peritoneais/efeitos dos fármacos , Piperidinas/farmacologia , Alcamidas Poli-Insaturadas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Modelos Animais de Doenças , Escherichia coli/imunologia , Escherichia coli/patogenicidade , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/patologia , Feminino , Cadeia Pesada da Proteína-1 Reguladora de Fusão/metabolismo , Células HeLa , Humanos , Imunidade Inata/efeitos dos fármacos , Mediadores da Inflamação/metabolismo , Interleucina-6/metabolismo , Transportador 1 de Aminoácidos Neutros Grandes/genética , Transportador 1 de Aminoácidos Neutros Grandes/metabolismo , Lipopolissacarídeos/farmacologia , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/metabolismo , Macrófagos Peritoneais/microbiologia , Macrófagos Peritoneais/patologia , Masculino , Alvo Mecanístico do Complexo 1 de Rapamicina , Camundongos , Camundongos Endogâmicos C57BL , Complexos Multiproteicos/metabolismo , Fagocitose/efeitos dos fármacos , Células RAW 264.7 , Interferência de RNA , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Fatores de Tempo , Transfecção , Fator de Necrose Tumoral alfa/metabolismo
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