Background:Intestinal barrier plays key roles in maintaining intestinal homeostasis.Inflammation damage can severely destroy the intestinal integrity of mammals.This study was conducted to investigate the protective e...Background:Intestinal barrier plays key roles in maintaining intestinal homeostasis.Inflammation damage can severely destroy the intestinal integrity of mammals.This study was conducted to investigate the protective effects of embelin and its molecular mechanisms on intestinal inflammation in a porcine model.One hundred sixty 21-day-old castrated weaned pigs(Duroc×Landrace×Yorkshire,average initial body weight was 7.05 d to four groups and fed with a basal diet o±0.28 kg,equal numbers of castrated males and females)were allotter a basal diet containing 200,400,or 600 mg embelin/kg for 28 d.The growth performance,intestinal inflammatory cytokines,morphology of jejunum and ileum,tight junctions in the intestinal mucosa of piglets were tested.IPEC-1 cells with overexpression of P300/CBP associating factor(PCAF)were treated with embelin,the activity of PCAF and acetylation of nuclear factor-κB(NF-κB)were analyzed to determine the effect of embelin on PCAF/NF-κB pathway in vitro.Results:The results showed that embelin decreased(P<0.05)serum D-lactate and diamine oxidase(DAO)levels,and enhanced the expression of ZO-1,occludin and claudin-1 protein in jejunum and ileum.Moreover,the expression levels of critical inflammation molecules(interleukin-1β,interleukin-6,tumor necrosis factor-α,and NF-κB)were downregulated(P<0.05)by embelin in jejunal and ileal mucosa.Meanwhile,the activity of PCAF were down-regulated(P<0.05)by embelin.Importantly,transfection of PCAF siRNAs to IPEC-1 cell decreased NF-κB activities;embelin treatment downregulated(P<0.05)the acetylation and activities of NF-κB by 31.7%-74.6%in IPEC-1 cells with overexpression of PCAF.Conclusions:These results suggested that embelin ameliorates intestinal inflammation in weaned pigs,which might be mediated by suppressing the PCAF/NF-κB signaling pathway.展开更多
Background:Fascin is crucial for cancer cell filopodium formation and tumor metastasis,and is functionally regulated by post-translational modifications.However,whether and how Fascin is regulated by acetylation remai...Background:Fascin is crucial for cancer cell filopodium formation and tumor metastasis,and is functionally regulated by post-translational modifications.However,whether and how Fascin is regulated by acetylation remains unclear.This study explored the regulation of Fascin acetylation and its corresponding roles in filopodium formation and tumor metastasis.Methods:Immunoprecipitation and glutathione-S-transferase pull-down assays were performed to examine the interaction between Fascin and acetyltransferase P300/CBP-associated factor(PCAF),and immunofluorescence was used to investigate their colocalization.An in vitro acetylation assay was performed to identify Fascin acetylation sites by using mass spectrometry.A specific antibody against acetylated Fascin was generated and used to detect the PCAF-mediated Fascin acetylation in esophageal squamous cell carcinoma(ESCC)cells using Western blotting by overexpressing and knocking down PCAF expression.An in vitro cell migration assay was performed,and a xenograft model was established to study in vivo tumor metastasis.Live-cell imaging and fluorescence recovery after photobleaching were used to evaluate the function and dynamics of acetylated Fascin in filopodium formation.The clinical significance of acetylated Fascin and PCAF in ESCC was evaluated using immunohistochemistry.Results:Fascin directly interacted and colocalized with PCAF in the cytoplasm and was acetylated at lysine 471(K471)by PCAF.Using the specific antiAcK471-Fascin antibody,Fascin was found to be acetylated in ESCC cells,and the acetylation level was consequently increased after PCAF overexpression and decreased after PCAF knockdown.Functionally,Fascin-K471 acetylation markedly suppressed in vitro ESCC cell migration and in vivo tumor metastasis,whereas Fascin-K471 deacetylation exhibited a potent oncogenic function.Moreover,Fascin-K471 acetylation reduced filopodial length and density,and lifespan of ESCC cells,while its deacetylation produced the opposite effect.In the filipodium shaft,K471-acetylated Fascin displayed rapid dynamic exchange,suggesting that it remained in its monomeric form owing to its weakened actinbundling activity.Clinically,high levels of AcK471-Fascin in ESCC tissues were strongly associated with prolonged overall survival and disease-free survival of ESCC patients.Conclusions:Fascin interacts directly with PCAF and is acetylated at lysine 471 in ESCC cells.Fascin-K471 acetylation suppressed ESCC cell migration and tumor metastasis by reducing filopodium formation through the impairment of its actin-bundling activity.展开更多
Simulated results from a detailed elementary reaction mechanism for methane-containing species in flames consisting of nitrogen (NOx), C1 or C2 fuels are presented, and compared with reduced mechanism;this mechanism h...Simulated results from a detailed elementary reaction mechanism for methane-containing species in flames consisting of nitrogen (NOx), C1 or C2 fuels are presented, and compared with reduced mechanism;this mechanism have been constructed with the analysis of the rate sensitivity matrix f (PCAF method), and the computational singular perturbation (CSP). The analysis was performed on solutions of unstrained adiabatic premixed flames with detailed chemical kinetics described by GRI 3.0 for methane including NOx formation. A 9-step reduced mechanism for methane has been constructed which reproduces accurately laminar burning velocities, flame temperatures and mass fraction distributions of major species for the whole flammability range. Many steady-state species are also predicted satisfactorily. This mechanism is especially for lean flames. This mechanism is accurate for a wide range of the equivalence ratio (1, 0.9, 0.8, and 0.7) and for pressures as high as 40 atm to 60 atm. For both fuels, the CSP algorithm automatically pointed to the same steady-state species as those identified by laborious analysis or intuition in the literature and the global reactions were similar to well established previous methane-reduced mechanisms. This implies that the method is very well suited for the study of complex mechanisms for heavy hydrocarbon combustion.展开更多
Tumor metastasis represents the main causes of cancer-related death.Our recent study showed that chemokine CCL18 secreted from tumor-associated macrophages regulates breast tumor metastasis,but the underlying mechanis...Tumor metastasis represents the main causes of cancer-related death.Our recent study showed that chemokine CCL18 secreted from tumor-associated macrophages regulates breast tumor metastasis,but the underlying mechanisms remain less clear.Here, we show that ARF6 GTPase-activating protein ACAP4 regulates CCL18-elicited breast cancer cell migration via the acetyltransferase PCAF-mediated acetylation.CCL18 stimulation elicited breast cancer cell migration and invasion via PCAF-dependent acetylation.ACAP4 physically interacts with PCAF and is a cognate substrate of PCAF during CCL18 stimulation.The acetylation site of ACAP4 by PCAF was mapped to Lys311 by mass spectrometric analyses.Importantly,dynamic acetylation of ACAP4 is essential for CCL18-induced breast cancer cell migration and invasion,as overexpression of the persistent acetylation-mimicking or nonacetylatable ACAP4 mutant blocked CCL18-elicited cell migration and invasion.Mechanistically,the acetylation of ACAP4 at Lys311 reduced the lipid-binding activity of ACAP4 to ensure a robust and dynamic cycling of ARF6-ACAP4 complex with plasma membrane in response to CCL18 stimulation.Thus,these results present a previously undefined mechanism by which CCL18-elicited acetylation of the PH domain controls dynamic interaction between ACAP4 and plasma membrane during breast cancer cell migration and invasion.展开更多
基金supported by the National Natural Science Foundation of China(Grant no.32072742)National Key Research and Development Program(Grant no.2021YFD1300300)the Fellowship of China Postdoctoral Science Foundation(grant no.2022M711274)。
文摘Background:Intestinal barrier plays key roles in maintaining intestinal homeostasis.Inflammation damage can severely destroy the intestinal integrity of mammals.This study was conducted to investigate the protective effects of embelin and its molecular mechanisms on intestinal inflammation in a porcine model.One hundred sixty 21-day-old castrated weaned pigs(Duroc×Landrace×Yorkshire,average initial body weight was 7.05 d to four groups and fed with a basal diet o±0.28 kg,equal numbers of castrated males and females)were allotter a basal diet containing 200,400,or 600 mg embelin/kg for 28 d.The growth performance,intestinal inflammatory cytokines,morphology of jejunum and ileum,tight junctions in the intestinal mucosa of piglets were tested.IPEC-1 cells with overexpression of P300/CBP associating factor(PCAF)were treated with embelin,the activity of PCAF and acetylation of nuclear factor-κB(NF-κB)were analyzed to determine the effect of embelin on PCAF/NF-κB pathway in vitro.Results:The results showed that embelin decreased(P<0.05)serum D-lactate and diamine oxidase(DAO)levels,and enhanced the expression of ZO-1,occludin and claudin-1 protein in jejunum and ileum.Moreover,the expression levels of critical inflammation molecules(interleukin-1β,interleukin-6,tumor necrosis factor-α,and NF-κB)were downregulated(P<0.05)by embelin in jejunal and ileal mucosa.Meanwhile,the activity of PCAF were down-regulated(P<0.05)by embelin.Importantly,transfection of PCAF siRNAs to IPEC-1 cell decreased NF-κB activities;embelin treatment downregulated(P<0.05)the acetylation and activities of NF-κB by 31.7%-74.6%in IPEC-1 cells with overexpression of PCAF.Conclusions:These results suggested that embelin ameliorates intestinal inflammation in weaned pigs,which might be mediated by suppressing the PCAF/NF-κB signaling pathway.
基金National Natural Science Foundation of China,Grant/Award Numbers:81872372,81902469Natural Science Foundation of China-Guangdong Joint Fund,Grant/Award Number:U0932001+2 种基金National Cohort of Esophageal Cancer of China,Grant/Award Number:2016YFC0901400China Postdoctoral Science Foundation,Grant/Award Number:2018M6431342020 Li Ka Shing Foundation Cross-Disciplinary Research Grant,Grant/Award Number:2020LKSFG07B。
文摘Background:Fascin is crucial for cancer cell filopodium formation and tumor metastasis,and is functionally regulated by post-translational modifications.However,whether and how Fascin is regulated by acetylation remains unclear.This study explored the regulation of Fascin acetylation and its corresponding roles in filopodium formation and tumor metastasis.Methods:Immunoprecipitation and glutathione-S-transferase pull-down assays were performed to examine the interaction between Fascin and acetyltransferase P300/CBP-associated factor(PCAF),and immunofluorescence was used to investigate their colocalization.An in vitro acetylation assay was performed to identify Fascin acetylation sites by using mass spectrometry.A specific antibody against acetylated Fascin was generated and used to detect the PCAF-mediated Fascin acetylation in esophageal squamous cell carcinoma(ESCC)cells using Western blotting by overexpressing and knocking down PCAF expression.An in vitro cell migration assay was performed,and a xenograft model was established to study in vivo tumor metastasis.Live-cell imaging and fluorescence recovery after photobleaching were used to evaluate the function and dynamics of acetylated Fascin in filopodium formation.The clinical significance of acetylated Fascin and PCAF in ESCC was evaluated using immunohistochemistry.Results:Fascin directly interacted and colocalized with PCAF in the cytoplasm and was acetylated at lysine 471(K471)by PCAF.Using the specific antiAcK471-Fascin antibody,Fascin was found to be acetylated in ESCC cells,and the acetylation level was consequently increased after PCAF overexpression and decreased after PCAF knockdown.Functionally,Fascin-K471 acetylation markedly suppressed in vitro ESCC cell migration and in vivo tumor metastasis,whereas Fascin-K471 deacetylation exhibited a potent oncogenic function.Moreover,Fascin-K471 acetylation reduced filopodial length and density,and lifespan of ESCC cells,while its deacetylation produced the opposite effect.In the filipodium shaft,K471-acetylated Fascin displayed rapid dynamic exchange,suggesting that it remained in its monomeric form owing to its weakened actinbundling activity.Clinically,high levels of AcK471-Fascin in ESCC tissues were strongly associated with prolonged overall survival and disease-free survival of ESCC patients.Conclusions:Fascin interacts directly with PCAF and is acetylated at lysine 471 in ESCC cells.Fascin-K471 acetylation suppressed ESCC cell migration and tumor metastasis by reducing filopodium formation through the impairment of its actin-bundling activity.
文摘Simulated results from a detailed elementary reaction mechanism for methane-containing species in flames consisting of nitrogen (NOx), C1 or C2 fuels are presented, and compared with reduced mechanism;this mechanism have been constructed with the analysis of the rate sensitivity matrix f (PCAF method), and the computational singular perturbation (CSP). The analysis was performed on solutions of unstrained adiabatic premixed flames with detailed chemical kinetics described by GRI 3.0 for methane including NOx formation. A 9-step reduced mechanism for methane has been constructed which reproduces accurately laminar burning velocities, flame temperatures and mass fraction distributions of major species for the whole flammability range. Many steady-state species are also predicted satisfactorily. This mechanism is especially for lean flames. This mechanism is accurate for a wide range of the equivalence ratio (1, 0.9, 0.8, and 0.7) and for pressures as high as 40 atm to 60 atm. For both fuels, the CSP algorithm automatically pointed to the same steady-state species as those identified by laborious analysis or intuition in the literature and the global reactions were similar to well established previous methane-reduced mechanisms. This implies that the method is very well suited for the study of complex mechanisms for heavy hydrocarbon combustion.
基金the National Natural Science Foundation of China (31430054,31621002,31320103904, 81630080,31671405,31471275,and 31501130)the National Key Research and Development Program of China (2017YFA0503600,2016YFA0100500,and 2016YFA0101202)+3 种基金the Ministry of Education (IRT_17R102,20113402130010)the Strategic Priority Research Program of Chinese Academy of Sciences (XDB19000000)National Institutes of Health Grants (CA 164133,DK115812,and DK56292)Central University Grants (WK2070000066).
文摘Tumor metastasis represents the main causes of cancer-related death.Our recent study showed that chemokine CCL18 secreted from tumor-associated macrophages regulates breast tumor metastasis,but the underlying mechanisms remain less clear.Here, we show that ARF6 GTPase-activating protein ACAP4 regulates CCL18-elicited breast cancer cell migration via the acetyltransferase PCAF-mediated acetylation.CCL18 stimulation elicited breast cancer cell migration and invasion via PCAF-dependent acetylation.ACAP4 physically interacts with PCAF and is a cognate substrate of PCAF during CCL18 stimulation.The acetylation site of ACAP4 by PCAF was mapped to Lys311 by mass spectrometric analyses.Importantly,dynamic acetylation of ACAP4 is essential for CCL18-induced breast cancer cell migration and invasion,as overexpression of the persistent acetylation-mimicking or nonacetylatable ACAP4 mutant blocked CCL18-elicited cell migration and invasion.Mechanistically,the acetylation of ACAP4 at Lys311 reduced the lipid-binding activity of ACAP4 to ensure a robust and dynamic cycling of ARF6-ACAP4 complex with plasma membrane in response to CCL18 stimulation.Thus,these results present a previously undefined mechanism by which CCL18-elicited acetylation of the PH domain controls dynamic interaction between ACAP4 and plasma membrane during breast cancer cell migration and invasion.
