Knockdown of PTEN promotes colon cancer progression and induces M2 macrophage polarization in the colon cancer cell environment

Objective: This article aims to study the effect of phosphate and tension homolog deleted on chromosome ten (PTEN) knockdown on colon cancer progression and macrophage polarization in the cancer environment. Materials and Methods and Results: The expression of PTEN in colon cancer tissues and colon cancer cells was significantly lower than in precancerous tissues or CCD-18Co cells, and the decrease was most evident in SW620 cells. The expressions of phosphate (p)-p38, c-Jun N-terminal kinase (JNK), activator protein 1 (AP-1), B-cell lymphoma-2 (Bcl-2) protein in colon cancer tissues and cells were significantly higher than in precancerous tissues or CCD-18Co cells (P-values < 0.05). Bcl-2-associated X (Bax) and Caspase-3 expressions in colon cancer tissues and cells were significantly lower than in precancerous tissues or CCD-18Co cells (P-values < 0.05). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was applied to measure cell viability. Transwell evaluated the cell migration and invasion ability. Si-PTEN improved the proliferation, migration, and invasion of SW620 cells (P-values < 0.05). The expression levels of arginase-1 (Arg-1), CD163, CD206 in colon cancer tissues were significantly higher than in precancerous tissues (P-values < 0.05). The cell cycle, the number of M1 and M2 double-positive cells were assessed by flow cytometry. Si-PTEN reduced the expression of tumor necrosis factor-alpha (TNF-?), interleukin-1beta (IL-1?), and inducible nitric oxide synthase (iNOS), which upregulated the expression of Arg-1, CD206, CD163, p-p38, JNK, and AP-1 (P-values < 0.05). Conclusion: Si-PTEN promoted colon cancer progression and induced the polarization of M2 tumor-associated macrophages in the colon cancer cell environment.

Effects of Total Saponins from Dioscorea Nipponica Makino on Monosodium Urate-Induced M1-Polarized Macrophages through Arachidonic Acid Signaling Pathway: An in vitro Study / 中国结合医学杂志

OBJECTIVE@#To investigate and reveal the underlying mechanism of the effect of total saponins from Dioscoreae nipponica Makino (TSDN) on the arachidonic acid pathway in monosodium urate (MSU) crystal-induced M1-polarized macrophages.@*METHODS@#M1 polarization of RAW264.7 cells were induced by 1 µ g/mL lipopolysaccharide (LPS). The methylthiazolyldiphenyl-tetrazolium bromide method was then used to screen the concentration of TSDN. MSU (500 µ g/mL) was used to induce the gouty arthritis model. Afterwards, 10 µ g/L TSDN and 8 µ mol/L celecoxib, which was used as a positive control, were added to the above LPS and MSU-induced cells for 24 h. The mRNA and protein expressions of cyclooxygenase (COX) 2, 5-lipoxygenase (5-LOX), microsomal prostaglandin E synthase derived eicosanoids (mPGES)-1, leukotriene B (LTB)4, cytochrome P450 (CYP) 4A, and prostaglandin E2 (PGE2) were tested by real-time polymerase chain reaction and Western blotting, respectively. The enzyme-linked immunosorbent assay was used to test the contents of M1 markers, including inducible nitric oxid synthase (NOS) 2, CD80, and CD86.@*RESULTS@#TSDN inhibited the proliferation of M1 macrophages and decreased both the mRNA and protein expressions of COX2, 5-LOX, CYP4A, LTB4, and PGE2 (P<0.01) while increased the mRNA and protein expression of mPGES-1 (P<0.05 or P<0.01). TSDN could also significantly decrease the contents of NOS2, CD80, and CD86 (P<0.01).@*CONCLUSION@#TSDN has an anti-inflammation effect on gouty arthritis in an in vitro model by regulating arachidonic acid signaling pathway.

Total Saponin Fraction of Dioscorea Nipponica Makino Improves Gouty Arthritis Symptoms in Rats via M1/M2 Polarization of Monocytes and Macrophages Mediated by Arachidonic Acid Signaling / 中国结合医学杂志

OBJECTIVE@#To explore the mechanism of effects of total saponin fraction from Dioscorea Nipponica Makino (TSDN) on M1/M2 polarization of monocytes/macrophages and arachidonic acid (AA) pathway in rats with gouty arthritis (GA).@*METHODS@#Seventy-two Sprague Dawley rats were randomly divided into 4 groups (n=18 in each): normal, model, TSDN at 160 mg/kg, and celecoxib at 43.3 mg/kg. Monosodium urate crystal (MSU) was injected into the rats' ankle joints to induce an experimental GA model. Blood and tissue samples were collected on the 3rd, 5th, and 8th days of drug administration. Histopathological changes in the synovium of joints were observed via hematoxylin and eosin (HE) staining. The expression levels of arachidonic acid (AA) signaling pathway were assessed via real-time polymerase chain reaction (qPCR) and Western blot. Flow cytometry was used to determine the proportion of M1 and M2 macrophages in the peripheral blood. An enzyme-linked immunosorbent assay (ELISA) was used to detect interleukine (IL)-1 β, tumor necrosis factor-alpha (TNF-α), IL-4, IL-10, prostaglandin E2 (PGE2), and leukotriene B4 (LTB4).@*RESULTS@#HE staining showed that TSDN improved the synovial tissue. qPCR and Western blot showed that on the 3rd, 5th and 8th days of drug administration, TSDN reduced the mRNA and protein expressions of cyclooxygenase (COX)2, microsomal prostaglandin E synthase-1 derived eicosanoids (mPGES-1), 5-lipoxygenase (5-LOX), recombinant human mothers against decapentaplegic homolog 3 (Smad3), nucleotide-binding oligomerization domain-like receptor protein 3 (NALP3), and inducible nitric oxide synthase (iNOS) in rats' ankle synovial tissues (P<0.01). TSDN decreased COX1 mRNA and protein expression on 3rd and 5th day of drug administration and raised it on the 8th day (both P<0.01). It lowered CD68 protein expression on days 3 (P<0.01), as well as mRNA and protein expression on days 5 and 8 (P<0.01). On the 3rd, 5th, and 8th days of drug administration, TSDN elevated the mRNA and protein expression of Arg1 and CD163 (P<0.01). Flow cytometry results showed that TSDN decreased the percentage of M1 macrophages while increasing the percentage of M2 in peripheral blood (P<0.05 or P<0.01). ELISA results showed that on the 3rd, 5th, and 8th days of drug administration, TSDN decreased serum levels of IL-1 β, TNF-α, and LTB4 (P<0.01), as well as PGE2 levels on days 3rd and 8th days (P<0.05 or P<0.01); on day 8 of administration, TSDN increased IL-4 serum levels and enhanced IL-10 contents on days 5 and 8 (P<0.05 or P<0.01).@*CONCLUSION@#The anti-inflammatory effect of TSDN on rats with GA may be achieved by influencing M1/M2 polarization through AA signaling pathway.

Recombinant Human Peroxiredoxin-5 Improves Anti-tumor Immunity by Inducing Macrophage Polarization / 中国生物化学与分子生物学报

Tumor cells can use different strategies to suppress the immune system and disable them for killing tumor cells. Previous studies have shown that recombinant human peroxiredoxin-5 (hPRDX5) can activate the normal anti-tumor immune, so as to control and eliminate the tumor cells, but its exact mechanism of action needs to be studied in depth. The study aimed to investigate whether hPRDX5 exerts its anti-tumor activity by activating or reversing the polarization state of mouse macrophages RAW264. 7 cells. The results of CCK8 showed that different doses of hPRDX5 could significantly enhance the viability of macrophage compared with the control group (P < 0. 001); The results of Nitric oxide (NO) test showed that hPRDX5 significantly enhanced NO secretion levels in RAW264. 7 cells (P < 0. 001); ELISA experiments revealed that hPRDX5 promotes TNF-α (P<0. 01) and IL-6 (P<0. 001) secretion in RAW264. 7 cells; Flow cytometry revealed that hPRDX5 increased the expression of antigen differentiation cluster (CD) 80 (P < 0. 01) and inducible nitric oxide oxide synthase (iNOS) (P < 0. 001) in RAW264. 7 cells, and reduced the expression of CD206 (P < 0. 001) in RAW264. 7 cells induced by tumor conditional culture solution (TCS); Lactate dehydrogenase (LDH) experiments revealed that hPRDX5 can increase the killing activity of mouse macrophages on mouse pancreatic cancer Panc02 cells. hPRDX5 is able to activate mouse macrophage RAW264. 7 cells, promotes its M1-type polarization, reverses M2-type polarization, and exerts antitumor activity through the immune-enhancing effect.

Digoxin alleviates pulmonary fibrosis by inhibiting macrophage M2 polarization via regulating mTORC2-IRF4 signaling pathway / 中国药理学通报

Aim To investigate the protective effect of digoxin (Dig) on the bleomycin (BLM)-induced pulmonary fibrosis in mice and the underlying mechanism. Methods Pulmonary fibrosis model was established by intratracheal instillation of BLM (5 mg · kg

Tetrahydropalmatine alleviated diabetic neuropathic pain by inhibiting activation of microglia via p38 MAPK signaling pathway / 中国中药杂志

Neuropathic pain is one of the common complications of diabetes. Tetrahydropalmatine(THP) is a main active component of Corydalis Rhizoma with excellent anti-inflammatory and pain-alleviating properties. This study aims to investigate the therapeutic effect of THP on diabetic neuropathic pain(DNP) and the underlying mechanism. High-fat and high-sugar diet(4 weeks) and streptozotocin(STZ, 35 mg·kg~(-1), single intraperitoneal injection) were employed to induce type-2 DNP in rats. Moreover, lipopolysaccharide(LPS) was used to induce the activation of BV2 microglia in vitro to establish an inflammatory cellular model. Fasting blood glucose(FBG) was measured by a blood glucose meter. Mechanical withdrawal threshold(MWT) was assessed with von Frey filaments, and thermal withdrawal latency(TWL) with hot plate apparatus. The protein expression levels of OX42, inducible nitric oxide synthase(iNOS), CD206, p38, and p-p38 were determined by Western blot, the fluorescence expression levels of OX42 and p-p38 in the dorsal horn of the rat spinal cord by immunofluorescence, the mRNA content of p38 and OX42 in rat spinal cord tissue by qRT-PCR, and levels of nitric oxide(NO), interleukin-1β(IL-1β), interleukin-6(IL-6), tumor necrosis factor-α(TNF-α), interleukin-10(IL-10), and serum fasting insulin(FINS) by enzyme-linked immunosorbent assay(ELISA). RESULTS:: showed that the mo-del group demonstrated significant decrease in MWT and TWL, with pain symptoms. THP significantly improved the MWT and TWL of DNP rats, inhibited the activation of microglia and p38 MAPK signaling pathway in rat spinal cord, and ameliorated its inflammatory response. Meanwhile, THP promoted the change of LPS-induced BV2 microglia from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype, suppressed the activation of the p38 MAPK signaling pathway, decreased the expression levels of inflammatory factors NO, IL-1β, IL-6, and TNF-α, and increased the expression level of anti-inflammatory factor IL-10. The findings suggested that THP can significantly ameliorate the pain symptoms of DNP rats possibly by inhibiting the inflammatory response caused by M1 polarization of microglia via the p38 MAPK pathway.

Intermedin inhibits lipopolysaccharide-induced polarization of macrophages by activating AMPK signaling pathway / 中国药理学通报

Aim To evaluate the mechanism by which intermdin(IMD)inhibits lipopolysaccha ride(LPS)-induced polarization in RAW264.7 cells.Methods RAW264.7 cells were divided into control groups, LPS groups, LPS+IMD groups, LPS+IMD+Compound C groups.The mRNA expressions of tumor necrosis factor-α,(TNF-α,), CD86, inducible nitric oxide synthase(iNOS), Arginase-1(Arg-1)and CD206 were detected by Realtime-PCR.The protein expressions of p-AMPK, AMPK, TNF-α, intereukin-6(IL-6)and intereukin-10(IL-10)were detected by Western blot.The proportion of CD86+ M1 type cells was detected by Flow cytometry.In addition, the expression levels of supernatant cytokines, including IL-6 and TNF-α, were detected by ELISA.Results Compared with control and LPS groups, IMD treatment could up-regulate the expression level of p-AMPK and the ratio of p-AMPK/AMPK.LPS promoted M1 polarization, since the expressions of CD86, TNF-α and iNOS increased, while the expressions of CD206 and Arg-1 decreased by LPS induction.The proportion of M1 type cells increased and the secretion of TNF-α, IL-6 in the cell supernatant increased.And IMD treatment could inhibit the polarization of M1 induced by LPS.These effects were reversed by Compound C, an inhibitor of AMPK.Conclusion IMD can inhibit the M1-type polarization of LPS-induced macrophages by activating AMPK signaling pathway.

Mechanism of Total Saponins from Dioscoreae Nipponicae Rhizoma to Treat Gouty Arthritis by Regulating M1/M2 Polarization of Macrophages / 中国实验方剂学杂志

Objective:To illustrate the effect of M1/M2 polarization of macrophages on gouty arthritis models induced with monosodium urate and reveal the molecular mechanism of total saponins from Dioscoreae Nipponicae Rhizoma to treat gouty arthritis. Method:A total of 72 male SD rats were randomly divided into four groups： normal group， model group， total saponin group （160 mg·kg^-1）， celecoxib group （43.3 mg·kg^-1）， with 18 rats in each group. Gouty arthritis models were induced by injecting monosodium urate into ankle joints bilaterally. Histopathology changes of ankle joints were observed by hematoxylin-eosin（HE） staining. Immunohistochemistry method was used to detect the protein expression change of CD68， interleukin-4（IL-4）， inducible nitric oxide synthase （iNOS） and transforming growth factor-<italic>β</italic>₁（TGF-<italic>β</italic>₁）. Result:HE staining results showed that the inflammation of the model group was most obvious on the third day after modeling， and the disease was in the acute stage. On day 5， the inflammation was alleviated， and on day 8， the inflammation was still present but close to normal. The total saponin group and celecoxib group could improve the pathological changes of synovial tissue， and the effect of total saponin group was more obvious. Immunohistochemical results were as follows. Compared with the normal group. The expression of CD68 and iNOS in the model group increased on the 3rd，5th and 8th day of administration （<italic>P</italic><0.01）. Compared with the model group， the total saponins group could reduce the expression of CD68 and iNOS （<italic>P</italic><0.05，<italic>P</italic><0.01）on the 3rd day of administration， and significantly reduced them expression on the 5th and 8th days （<italic>P</italic><0.01）. Compared with the normal group， IL-4 and TGF-<italic>β</italic>₁ expression were increased in the model group when the drug was given for three days（<italic>P</italic><0.01）. Total saponin group could enhance IL-4 expression（<italic>P</italic><0.05）and decreased the TGF-<italic>β</italic>₁ expression（<italic>P</italic><0.01）. Compared with normal group， the expression of IL-4 in the model group decreased on the 5th and 8th day of administration （<italic>P</italic><0.01）， and the expression of TGF-<italic>β</italic>₁ in the model group decreased on the 5th day of administration（<italic>P</italic><0.01）. Compared with the model group， the total saponins group could increase the expression of IL-4 and TGF-<italic>β</italic>₁ at 5 d and 8 d after administration （<italic>P</italic><0.01）. Conclusion:Total saponins from Dioscoreae Nipponicae Rhizoma has the potential effect to treat gouty arthritis by regulating M1/M2 polarization.

Effect of leonurine on peritoneal macrophages M1/M2 phenotypic differentiation via inhibiting overactivation of NLRP3 inflammasome / 药学实践杂志

Objective To find the effect of leonurine on LPS-induced macrophages activation and its potential mechanism. Methods Mouse primary peritoneal macrophages were isolated and pretreated for 24 h with LPS and leonurine. MTT assay was used to detect the cell viability of macrophages. The production of IL-1β, IL-6, TNF-α and IL-18 in culture medium were tested by ELISA, and the production of NO was detected by Griess reagent. The mRNA expression of NLRP3, ASC, caspase-1, TNF-α, iNOS, Arg-1 and CD206 were detected by RT-PCR, and the protein expression of NLRP3, ASC and caspase-1 were detected by Western blotting. Results LPS can significantly increase the releases of NO、IL-1β、IL-6、TNF-α and IL-18 from macrophages. Leonurine can suppress the expression of pro-inflammatory factor levels, such as IL-1β (P<0.05), IL-18 (P<0.05), NO(P<0.05), IL-6(P<0.05) and TNF-α (P<0.05). Leonurine can decrease the activation of macrophage as well as the expression of NLRP3 Inflammasome.Protein expressions of NLRP3、ASC、caspase-1 were mitigated. Conclution Leonurine exerts beneficial effects through M1/M2 phenotypic differentiation of peritoneal macrophage via inhibiting overactivation of NLRP3 inflammasome. These findings suggest that leonurine might have a therapeutic potential for pelvic inflammatory disease.

Construction of a curcumin-siRNA co-delivery system based on mesoporous silica and its effect on M2-type polarization of macrophages / 口腔疾病防治

Objective @#To fabricate a co-delivery system of curcumin (CUR) and siRNA based on mesoporous silica nanoparticles (MSN) and investigate its potential application in inducing macrophage M2 polarization.@*Methods@# MSNs were synthesized using the conventional sol-gel method. The interior mesochannels were occupied by small-molecule CUR, while the exterior surface was adsorbed by cationic polymeric polyethyleneimine (PEI) to link the negatively charged siRNA molecules to formulate the (CUR@MSN)PEI/siRNA co-delivery system. The formulation process was monitored by transmission electron microscopy(TEM). The MTT assay was used to evaluate the cytotoxicity in RAW264.7 cells under various concentrations of nanoparticles. Confocal laser scanning microscopy and TEM were used to observe cell internalization using FAM-labeled siRNA. GAPDH-targeting siRNA was used to prepare nanoparticles and then was transfected into RAW264.7 cells to observe the silencing efficiency of target genes. The knockdown efficiency was examined by real-time quantitative PCR. The related control groups were untreated cells, CUR delivery only and the co-delivery of CUR and siRNA negative control. By loading miRNA-130a-3p antisense oligonucleotide (ASO) to transfect RAW264.7 cells, the effects on the polarization of macrophages were observed. The M2 polarization marker arginase 1 (Arg-1) was measured by western blotting. The related control groups were untreated cells, CUR delivery only and co-delivery of CUR and miRNA negative control. @* Results @# The (CUR@MSN)PEI/siRNA co-delivery system was successfully formulated. The nanoparticles exhibited dose-dependent cytotoxicity, and the cell viability was maintained over 90% when the nanoparticle concentration was less than 10 μg/mL. A high cell uptake efficiency was observed, and the target gene knockdown efficiency was greater than 80% (P < 0.05 vs. all the other groups). The CUR delivery-only group and co-delivery of the CUR-and miRNA-negative control group improved Arg-1 expression ~ 3-fold (P < 0.05 vs. untreated cells). Using the co-delivery of CUR and ASO, synergistic effects were obtained, and Arg-1 expression was increased ~ 8-fold (P < 0.05 vs. all the other groups).@*Conclusion @#The CUR-siRNA co-delivery system can effectively transfect macrophages and synergistically induce M2 polarization.

Effect of Ermiaosan on M1/M2 Polarization of Bone Marrow Derived-macrophages / 中国实验方剂学杂志

Objective:To explore the effect of Ermiaosan（EMS） on the polarization of M1 by lipopolysaccharide（LPS）+interferon(IFN)-γ and M2 induced by interleukin(IL)-4+IL-13 in rat bone marrow-derived macrophages. Method:Macrophages from rat bone marrow were extracted in vitro, stimulated by macrophage colony stimulating factor(M-CSF), induced to macrophages (marked by F4/80), stimulated by LPS+IFN-γ and induced to polarize to M1，while stimulated by IL-4+IL-13 and induced to polarize to M2. After adding different concentrations of EMS (0.2，0.4，0.8 g·L-1), the phenotypes of M1 and M2 were detected by immunofluorescence, and the effect of EMS on M1(marked by CD68 and iNOS)/M2(marked by CD206 and Arginase) polarization of macrophages from rat bone marrow was detected. Result:Compared with control group, LPS + IFN-γ could increase the polarization of M1 (P<0.01)，while IL-4+IL-13 could increase the polarization of M2 (P<0.01); compared with LPS+IFN-γ/IL-4+IL-13 group, EMS (0.2，0.4，0.8 g·L-1) could inhibit the polarization of M1 induced by LPS+IFN -γ for 24 hours (P<0.05), but had no significant effect on polarization of M2 induced by IL-4+IL-13. Conclusion:EMS can inhibit M1 polarization induced by LPS+IFN - γ, but has no effect on M2 polarization induced by IL-4+IL-13.

Inhibition effect of SUMOylation of peroxisome proliferator activated receptor γ1 on macrophage M2 polarization / 上海交通大学学报（医学版）

Objective • To investigate the role and the regulation mechanism of SUMOylation of peroxisome proliferator activated receptor γ1 (PPARγ1) in macrophage M2 polarization induced by interleukin-4 (IL-4). Methods • To investigate the SUMOylation of PPARγ1 and identify its SUMOylated site, immunoprecipitation (IP) with anti-FLAG/HA antibody and Western blotting were used after plasmids FLAG-PPARγ1-WT/mutant and HA-SUMO1 being co-transfected into HEK293T cells. To determine SENP1 can de-SUMOylate PPARγ1, IP was used when HEK293T cells were co-transfected by FLAG-PPARγ1-WT, HA-SUMO1 and RGS-SENP1-WT, or SENP1 mutant plasmids. The change of the endogenous SUMOylation of PPARγ1 during M2 polarization was checked by IP and Western blotting by using PPARγ or SUMO1 antibodies in cell lysates of RAW264.7 cells and primary peritoneal macrophages induced by IL-4. The expression of some M2 related marker genes were detected by real-time quantitative polymerase chain reaction in PPARγ1-WT/mutants stably-overexpressed RAW264.7 cells. Chromatin immunoprecipitation (ChIP) experiment was used to confirm the different ability of binding to the promoter of arginase (Arg1) between PPARγ1-WT and PPARγ1-K77R. Results • It has been identified that the major SUMOylated site of PPARγ1 was Lys77, which could be de-SUMOylated by SENP1. The endogenous SUMOylation of PPARγ1 decreased when macrophage polarized to M2 macrophage induced by IL-4. The expression of Arg1 increased in PPARγ1-K77R stably-overexpressed RAW264.7 cells. PPARγ1-K77R easily bound to the promoter of Arg1 gene, showing more transcription activity. Conclusion • De-SUMOylation of PPARγ1 at Lys77 can enhance its transcription activity by promoting the expression of Arg1 gene, which is involved in the regulation of macrophage M2 polarization.

S1P₁ Regulates M1/M2 Polarization toward Brain Injury after Transient Focal Cerebral Ischemia

M1/M2 polarization of immune cells including microglia has been well characterized. It mediates detrimental or beneficial roles in neuroinflammatory disorders including cerebral ischemia. We have previously found that sphingosine 1-phospate receptor subtype 1 (S1P₁) in post-ischemic brain following transient middle cerebral artery occlusion (tMCAO) can trigger microglial activation, leading to brain damage. Although the link between S1P₁ and microglial activation as a pathogenesis in cerebral ischemia had been clearly demonstrated, whether the pathogenic role of S1P₁ is associated with its regulation of M1/M2 polarization remains unclear. Thus, this study aimed to determine whether S1P₁ was associated with regulation of M1/M2 polarization in post-ischemic brain. Suppressing S1P₁ activity with its functional antagonist, AUY954 (5 mg/kg, p.o.), attenuated mRNA upregulation of M1 polarization markers in post-ischemic brain at 1 day and 3 days after tMCAO challenge. Similarly, suppressing S1P₁ activity with AUY954 administration inhibited M1-polarizatioin-relevant NF-κB activation in post-ischemic brain. Particularly, NF-κB activation was observed in activated microglia of post-ischemic brain and markedly attenuated by AUY954, indicating that M1 polarization through S1P₁ in post-ischemic brain mainly occurred in activated microglia. Suppressing S1P₁ activity with AUY954 also increased mRNA expression levels of M2 polarization markers in post-ischemic brain, further indicating that S1P₁ could also influence M2 polarization in post-ischemic brain. Finally, suppressing S1P₁ activity decreased phosphorylation of M1-relevant ERK1/2, p38, and JNK MAPKs, but increased phosphorylation of M2-relevant Akt, all of which were downstream pathways following S1P₁ activation. Overall, these results revealed S1P₁-regulated M1/M2 polarization toward brain damage as a pathogenesis of cerebral ischemia.

Agmatine Modulates the Phenotype of Macrophage Acute Phase after Spinal Cord Injury in Rats

Agmatine is a decarboxylated arginine by arginine decarboxylase. Agmatine is known to be a neuroprotective agent. It has been reported that agmatine works as a NMDA receptor blocker or a competitive nitric oxide synthase inhibitor in CNS injuries. In spinal cord injury, agmatine showed reduction of neuropathic pain, improvement of locomotor function, and neuroprotection. Macrophage is a key cellular component in neuroinflammation, a major cause of impairment after spinal cord injury. Macrophage has subtypes, M1 and M2 macrophages. M1 macrophage induces a pro-inflammatory response, but M2 inspires an anti-inflammatory response. In this study, it was clarified whether the neuroprotective effect of agmatine is related with the modulation of macrophage subdivision after spinal cord injury. Spinal cord injury was induced in rats with contusion using MASCIS. Animals received agmatine (100 mg/kg, IP) daily for 6 days beginning the day after spinal cord injury. The proportion of M1 and M2 macrophages are confirmed with immunohistochemistry and FACS. CD206+ & ED1+ cells were counted as M2 macrophages. The systemic treatment of agmatine increased M2 macrophages caudal side to epicenter 1 week after spinal cord injury in immunohistochemistry. M2 macrophage related markers, Arginase-1 and CD206 mRNA, were increased in the agmatine treatment group and M2 macrophage expressing and stimulated cytokine, IL-10 mRNA, also was significantly overexpressed by agmatine injection. Among BMPs, BMP2/4/7, agmatine significantly increased only the expression of BMP2 known to reduce M1 macrophage under inflammatory status. These results suggest that agmatine reduces impairment after spinal cord injury through modulating the macrophage phenotype.