Hyperlipidemia is a risk factor for clinically significant thrombotic events in cardiovascular diseases.Platelet reactivity in hyperlipidemic conditions is enhanced when platelet scavenger receptor CD36 recognizes oxi...Hyperlipidemia is a risk factor for clinically significant thrombotic events in cardiovascular diseases.Platelet reactivity in hyperlipidemic conditions is enhanced when platelet scavenger receptor CD36 recognizes oxidized lipids in oxidized low-density lipoprotein(ox-LDL)particles,a process that induces atherothrombosis.Sulforaphane(SFN)is a dietary isothiocyanate enriched in cruciferous vegetables and exerts multiple biological activities.The current study sought to investigate the efficacy of SFN on platelet hyperreactivity under hyperlipidemic conditions in vitro and in vivo.Using a series of platelet functional assays in human platelets in vitro,we demonstrated that SFN attenuated ox-LDL-increased platelet aggregation and activation(surface CD62P expression).Mechanistically,studies using pharmacological inhibitors clarified that these inhibitory effects of SFN were mainly modulated by down-regulating CD36-mediated activation of Src kinases,leading to enhanced activation of cyclic adenosine monophosphate/protein kinase A(cAMP/PKA)signaling,and resultant inhibition of NADPH oxidase 2(NOX2)-dependent generation of reactive oxygen species(ROS).Moreover,12-week supplementation of SFN-enriched broccoli sprout extract(BSE,0.06%diet)in hyperlipidemic C57BL/6J mice also decreased platelet hyperreactivity.Studies using pharmacological inhibitors of CD36,protein kinase A(PKA)and NOX2 showed that the efficacy of BSE supplementation was mainly through modulating CD36-mediated the cAMP/PKA/NOX2 signaling.Thus,through modulating the cAMP/PKA/NOX2 pathway and attenuating CD36-mediated platelet hyperreactivity,SFN may play important protective roles in atherothrombosis under hyperlipidemic conditions.展开更多
Background Konjac oligosaccharide(KOS),which is produced through the degradation of konjac glucomannan via enzymatic,chemical,or physical treatments,has been found to have laxative effects.The current study aimed to e...Background Konjac oligosaccharide(KOS),which is produced through the degradation of konjac glucomannan via enzymatic,chemical,or physical treatments,has been found to have laxative effects.The current study aimed to elucidate the mechanisms underlying the laxative effect of KOS.Methods KOS was administered by gavage to wild-type and 5-hydroxytryptamine 4 receptor(5-HT4R)-knockout C57BL/6 mice subjected to loperamide-induced constipation for four weeks.Following treatment,feces,blood,small intestine,colonic tissue,and intestinal contents were collected.Constipation-related parameters,gastrointestinal hormones,and Ca2+concentrations were evaluated.Histopathological changes were examined via hematoxylin and eosin staining.Immunofluorescence staining,Western blotting,and immunohistochemical staining were performed to detect the 5-HT4R/cyclic adenosine monophosphate(cAMP)/protein kinase A(PKA)pathway.Isolated smooth muscle cells(SMCs)were treated with KOS and GR113808(a 5-HT4R antagonist),morphologically observed under an inverted microscope,and identified byα-SMA immunofluorescence staining.Cell viability was assessed via CCK-8 assays.5-HT4R/cAMP/PKA/p-CREB pathway activity in SMCs was detected via Western blotting.Results KOS alleviated loperamide-induced constipation in mice.KOS activated the 5-HT4R/cAMP/PKA/p-CREB pathway in loperamide-induced constipated mice.The protective effect of KOS was significantly diminished in 5-HT4R−/−mice.KOS promoted the proliferation of SMCs by activating the 5-HT4R/cAMP/PKA/p-CREB signaling pathway.Conclusion KOS improves loperamide-induced constipation by activating the 5-HT4R/cAMP/PKA/p-CREB signaling pathway.展开更多
基金supported by the National Natural Science Foundation of China(82003451 and 82003455)Yunnan Fundamental Research Projects(202101AT070033)the Start-Up Fund for Introduction of High-level Talents to Dali University(YBS2021015).
文摘Hyperlipidemia is a risk factor for clinically significant thrombotic events in cardiovascular diseases.Platelet reactivity in hyperlipidemic conditions is enhanced when platelet scavenger receptor CD36 recognizes oxidized lipids in oxidized low-density lipoprotein(ox-LDL)particles,a process that induces atherothrombosis.Sulforaphane(SFN)is a dietary isothiocyanate enriched in cruciferous vegetables and exerts multiple biological activities.The current study sought to investigate the efficacy of SFN on platelet hyperreactivity under hyperlipidemic conditions in vitro and in vivo.Using a series of platelet functional assays in human platelets in vitro,we demonstrated that SFN attenuated ox-LDL-increased platelet aggregation and activation(surface CD62P expression).Mechanistically,studies using pharmacological inhibitors clarified that these inhibitory effects of SFN were mainly modulated by down-regulating CD36-mediated activation of Src kinases,leading to enhanced activation of cyclic adenosine monophosphate/protein kinase A(cAMP/PKA)signaling,and resultant inhibition of NADPH oxidase 2(NOX2)-dependent generation of reactive oxygen species(ROS).Moreover,12-week supplementation of SFN-enriched broccoli sprout extract(BSE,0.06%diet)in hyperlipidemic C57BL/6J mice also decreased platelet hyperreactivity.Studies using pharmacological inhibitors of CD36,protein kinase A(PKA)and NOX2 showed that the efficacy of BSE supplementation was mainly through modulating CD36-mediated the cAMP/PKA/NOX2 signaling.Thus,through modulating the cAMP/PKA/NOX2 pathway and attenuating CD36-mediated platelet hyperreactivity,SFN may play important protective roles in atherothrombosis under hyperlipidemic conditions.
文摘Background Konjac oligosaccharide(KOS),which is produced through the degradation of konjac glucomannan via enzymatic,chemical,or physical treatments,has been found to have laxative effects.The current study aimed to elucidate the mechanisms underlying the laxative effect of KOS.Methods KOS was administered by gavage to wild-type and 5-hydroxytryptamine 4 receptor(5-HT4R)-knockout C57BL/6 mice subjected to loperamide-induced constipation for four weeks.Following treatment,feces,blood,small intestine,colonic tissue,and intestinal contents were collected.Constipation-related parameters,gastrointestinal hormones,and Ca2+concentrations were evaluated.Histopathological changes were examined via hematoxylin and eosin staining.Immunofluorescence staining,Western blotting,and immunohistochemical staining were performed to detect the 5-HT4R/cyclic adenosine monophosphate(cAMP)/protein kinase A(PKA)pathway.Isolated smooth muscle cells(SMCs)were treated with KOS and GR113808(a 5-HT4R antagonist),morphologically observed under an inverted microscope,and identified byα-SMA immunofluorescence staining.Cell viability was assessed via CCK-8 assays.5-HT4R/cAMP/PKA/p-CREB pathway activity in SMCs was detected via Western blotting.Results KOS alleviated loperamide-induced constipation in mice.KOS activated the 5-HT4R/cAMP/PKA/p-CREB pathway in loperamide-induced constipated mice.The protective effect of KOS was significantly diminished in 5-HT4R−/−mice.KOS promoted the proliferation of SMCs by activating the 5-HT4R/cAMP/PKA/p-CREB signaling pathway.Conclusion KOS improves loperamide-induced constipation by activating the 5-HT4R/cAMP/PKA/p-CREB signaling pathway.
