Effects of histone methyltransferase inhibitor on the polarization of peritoneal macrophages in septic mice / 中华危重病急救医学

ABSTRACT

Objective? To?investigate?the?effect?of?histone?methyltransferase?(EZH2)?inhibitor?on?the?polarization??of?peritoneal?macrophages?in?septic?mice.? Methods? Thirty-six?healthy?male?C57BL/6J?mice?were?divided?into?three?groups?by?random?number?table?method?(n?=?12)?sham?operated?group?(Sham?group),?sepsis?model?group?(CLP?group)??and?EZH2?inhibitor?treatment?group?(CLP+3-DZNeP?group).?Sepsis?animal?model?was?established?by?cecum?ligation?and?puncture?(CLP);?Sham?group?was?challenged?only?by?cecum?traction?without?ligation.?3-Deazaneplanocin?A?(3-DZNeP)?1?mg/kg?was?intraperitoneal?injected?24?hours?before?and?1?hour?after?CLP?in?CLP+3-DZNeP?group.?Eight?mice?in?each?group?were?sacrificed?at?24?hours?after?surgery.?The?levels?of?proinflammatory?cytokines?interleukin-6??(IL-6)?and?tumor?necrosis?factor-α(TNF-α)?in?peritoneal?lavatory?fluid?were?detected?by?high?throughput?liquid?protein?chip.?The?expression?levels?of?inducible?nitrogenase?(iNOS)?and?macrophage?mannose?receptor?(CD206)?were?analyzed?by?flow?cytometry.?Mouse?peritoneal?macrophages?were?isolated?and?purified?by?adherent?method,?the?protein?expressions?of?EZH2,?peroxisome?proliferator-activated?receptorγ(PPARγ)?were?detected?by?Western?Blot.?The?remaining?4?mice?? were?sacrificed?at?48?hours?after?surgery,?the?histopathological?changes?of?lung?and?kidney?tissue?were?evaluated?by?hematoxylin-eosin?(HE)?staining.? Results? Compared?with?Sham?group,?the?infiltration?of?inflammatory?cells?in?lung?and?kidney?of?the?CLP?group,?the?levels?of?IL-6?and?TNF-α?in?peritoneal?lavatory?fluid?were?significant?increased??[IL-6?(ng/L)?7?794.75±405.56?vs.?78.63±74.09,?TNF-α(ng/L)?147.25±25.19?vs.?18.20±5.03,?both?P?<?0.01],?the?percentage?of?M1?type?macrophages?was?significantly?increased?[iNOS+?F4/80+?(13.18±8.80)%?vs.?(1.57±0.77)%,?P?<?0.05],?and?the?protein?expression?of?EZH2?was?significantly?increased?(EZH2/GAPDH?0.84±0.11?vs.?0.11±0.03,?P?<?0.01),?while?the?protein?expression?of?PPARγ?was?significantly?decreased?(PPARγ/GAPDH?0.09±0.01?vs.?0.27±0.09,?P?<?0.01).?Compared?with?CLP?group,?the?histopathological?changes?of?lung?and?kidney?in?CLP+3-DZNeP?group?were?significantly?alleviated,?the?levels?of?IL-6?and?TNF-α?in?peritoneal?lavatory?fluid?were?significantly?decreased?[IL-6?(ng/L)?4?207.10±876.60?vs.?7?794.75±405.56,?TNF-α(ng/L)?63.00±25.37?vs.?147.25±25.19,?both?P <?0.01?],?the?percentage?of?M1?type?macrophages?was?significantly?decreased?[iNOS+?F4/80+?(3.64±0.89)%?vs.?(13.18±8.80)%,??P?<?0.05],?while?the?percentage?of?M2?type?macrophages?was?significantly?increased?[CD206+?F4/80+?(17.68±5.63)%?vs.?(7.60±3.17)%,?P?<?0.01],?the?protein?expression?of?EZH2?was?significantly?decreased?(EZH2/GAPDH?0.53±0.09?vs.?0.84±0.11,?P?<?0.05),?and?the?protein?expression?of?PPARγ?was?significantly?increased?(PPARγ/GAPDH?0.39±0.14?vs.?0.09±0.01,?P?<?0.05).? Conclusions? Sepsis?induces?high?expression?of?EZH2?in?peritoneal?macrophages,?and?may?induce?polarization?of?M1?type?macrophages?by?inhibiting?the?expression?of?PPARγ?protein.?EZH2?inhibitor?3-DZNeP?can?lessen?the?inflammatory?cytokines?release?by?inhibiting?the?M1?type?macrophages?polarization.