The roles of macrophage migration inhibitory factor in retinal diseases

Macrophage migration inhibitory factor(MIF),a multifunctional cytokine,is secreted by various cells and participates in inflammatory reactions,including innate and adaptive immunity.There are some evidences that MIF is involved in many vitreoretinal diseases.For example,MIF can exacerbate many types of uveitis;measurements of MIF levels can be used to monitor the effectiveness of uveitis treatment.MIF also alleviates trauma-induced and glaucoma-induced optic nerve damage.Furthermore,MIF is critical for retinal/choroidal neovascularization,especially complex neovascularization.MIF exacerbates retinal degeneration;thus,anti-MIF therapy may help to mitigate retinal degeneration.MIF protects uveal melanoma from attacks by natural killer cells.The mechanism underlying the effects of MIF in these diseases has been demonstrated:it binds to cluster of differentiation 74,inhibits the c-Jun N-terminal kinase pathway,and triggers mitogen-activated protein kinases,extracellular signal-regulated kinase-1/2,and the phosphoinositide-3-kinase/Akt pathway.MIF also upregulates Toll-like receptor 4 and activates the nuclear factor kappa-B signaling pathway.This review focuses on the structure and function of MIF and its receptors,including the effects of MIF on uveal inflammation,retinal degeneration,optic neuropathy,retinal/choroidal neovascularization,and uveal melanoma.

Neutrophil peptide 1 accelerates the clearance of degenerative axons during Wallerian degeneration by activating macrophages after peripheral nerve crush injury

Macrophages play an important role in peripheral nerve regeneration,but the specific mechanism of regeneration is still unclear.Our preliminary findings indicated that neutrophil peptide 1 is an innate immune peptide closely involved in peripheral nerve regeneration.However,the mechanism by which neutrophil peptide 1 enhances nerve regeneration remains unclear.This study was designed to investigate the relationship between neutrophil peptide 1 and macrophages in vivo and in vitro in peripheral nerve crush injury.The functions of RAW 264.7 cells we re elucidated by Cell Counting Kit-8 assay,flow cytometry,migration assays,phagocytosis assays,immunohistochemistry and enzyme-linked immunosorbent assay.Axonal debris phagocytosis was observed using the CUBIC(Clear,Unobstructed Brain/Body Imaging Cocktails and Computational analysis)optical clearing technique during Wallerian degeneration.Macrophage inflammatory factor expression in different polarization states was detected using a protein chip.The results showed that neutrophil peptide 1 promoted the prolife ration,migration and phagocytosis of macrophages,and CD206 expression on the surfa ce of macrophages,indicating M2 polarization.The axonal debris clearance rate during Wallerian degeneration was enhanced after neutrophil peptide 1 intervention.Neutrophil peptide 1 also downregulated inflammatory factors interleukin-1α,-6,-12,and tumor necrosis factor-αin invo and in vitro.Thus,the results suggest that neutrophil peptide 1 activates macrophages and accelerates Wallerian degeneration,which may be one mechanism by which neutrophil peptide 1 enhances peripheral nerve regeneration.

Th17/Treg balance and macrophage polarization ratio in lower extremity arteriosclerosis obliterans

Objective:To explore the balance of peripheral blood T helper 17 cells/regulatory T cell(Th17/Treg)ratio and the polarization ratio of M1 and M2 macrophages in lower extremity arteriosclerosis obliterans(ASO).Methods:A rat model of lower extremity ASO was established,and blood samples from patients with lower extremity ASO before and after surgery were obtained.ELISA was used to detect interleukin 6(IL-6),IL-10,and IL-17.Real-time RCR and Western blot analyses were used to detect Foxp3,IL-6,IL-10,and IL-17 expression.Moreover,flow cytometry was applied to detect the Th17/Treg ratio and M1/M2 ratio.Results:Compared with the control group,the iliac artery wall of ASO rats showed significant hyperplasia,and the concentrations of cholesterol and triglyceride were significantly increased(P<0.01),indicating the successful establishment of ASO.Moreover,the levels of IL-6 and IL-17 in ASO rats were pronouncedly increased(P<0.05),while the IL-10 level was significantly decreased(P<0.05).In addition to increased IL-6 and IL-17 levels,the mRNA and protein levels of Foxp3 and IL-10 in ASO rats were significantly decreased compared with the control group.The Th17/Treg and M1/M2 ratios in the ASO group were markedly increased(P<0.05).These alternations were also observed in ASO patients.After endovascular surgery(such as percutaneous transluminal angioplasty and arterial stenting),all these changes were significantly improved(P<0.05).Conclusions:The Th17/Treg and M1/M2 ratios were significantly increased in ASO,and surgery can effectively improve the balance of Th17/Treg,and reduce the ratio of M1/M2,and the expression of inflammatory factors.

Single-Nucleus RNA Sequencing Reveals Cardiac Macrophage Landscape in Hypoplastic Left Heart Syndrome

Background:Hypoplastic left heart syndrome(HLHS)is one of the most challenging congenital heart diseases in clinical treatment.In cardiac tissues,resident macrophages fulfill critical functions in maintaining a stable cardiac state and have strong regenerative capacity and organ specificity.However,the molecular mechanisms of macro-phages in HLHS remained unclear.Methods:Single-nucleus RNA sequencing(snRNA-seq)data of HLHS and healthy control(donors)samples obtained from the Gene Expression Omnibus(GEO)database were normalized and clustered using the Seurat package.The“FindMarkers”function was used to screen differentially expressed genes(DEGs)between the HLHS and donor groups and to analyze the functional enrichment of the set of genes of interest.Finally,cell-cell communication,pseudotime,and single-cell regulatory network inference and cluster-ing(SCENIC)analyses were used to study the mechanisms of macrophages in HLHS.Results:Based on the snRNA-seq data of HLHS and donors,we identified a total of 9 cell clusters,among which the proportion of macrophages was significantly less in the HLHS group than in the control group.Subdivision of macrophage subpopulations(Macrophages 1,2,and 3)showed that Macrophages 1 was mainly involved in nervous system development,angiogenesis,and apoptotic processes.In addition,analysis of communication between Macro-phages 1 and cardiomyocytes revealed that ligand-acceptor pairs such as GAS6/AXL,IL6,IGF1,THY1,and L1CAM were present only in the donor group.Finally,pesudotime and SCENIC analyses demonstrated that FOXO3 and ELF2 played a critical role for Macrophages 1 to maintain cardiac function in patients with HLHS.Conclusion:Our study improved the current understanding of the molecular mechanisms of macrophage devel-opment in HLHS,showing that manipulating the regulatory role of macrophages in the heart can be a novel treat-ment for HLHS.

Growth differentiation factor 11 promotes macrophage polarization towards M2 to attenuate myocardial infarction via inhibiting Notch1 signaling pathway

Background:Myocardial infarctions(MI)is a major threat to human health especially in people exposed to cold environment.The polarization of macrophages towards different functional phenotypes(M1 macrophages and M2 macrophages)is closely related to MI repairment.The growth differentiation factor 11(GDF11)has been reported to play a momentous role in inflammatory associated diseases.In this study,we examined the regulatory role of GDF11 in macrophage polarization and elucidated the underlying mechanisms in MI.Methods:In vivo,the mice model of MI was induced by permanent ligation of the left anterior descending coronary artery(LAD),and mice were randomly divided into the sham group,MI group,and MI+GDF11 group.The protective effect of GDF11 on myocardial infarction and its effect on macrophage polarization were verified by echocardiography,triphenyl tetrazolium chloride staining and immunofluorescence staining of heart tissue.In vitro,based on the RAW264.7 cell line,the effect of GDF11 in promoting macrophage polarization toward the M2 type by inhibiting the Notch1 Signaling pathway was validated by qRT-PCR,Western blot,and flow cytometry.Results:We found that GDF11 was significantly downregulated in the cardiac tissue of MI mice.And GDF11 supplementation can improve the cardiac function.Moreover,GDF11 could reduce the proportion of M1 macrophages and increase the accumulation of M2 macrophages in the heart tissue of MI mice.Furthermore,the cardioprotective effect of GDF11 on MI mice was weakened after macrophage clearance.At the cellular level,application of GDF11 could inhibit the expression of M1 macrophage(classically activated macrophage)markers iNOS,interleukin(IL)-1β,and IL-6 in a dose-dependent manner.In contrast,GDF11 significantly increased the level of M2 macrophage markers including IL-10,CD206,arginase 1(Arg1),and vascular endothelial growth factor(VEGF).Interestingly,GDF11 could promote M1 macrophages polarizing to M2 macrophages.At the molecular level,GDF11 significantly down-regulated the Notch1 signaling pathway,the activation of which has been demonstrated to promote M1 polarization in macrophages.Conclusions:GDF11 promoted macrophage polarization towards M2 to attenuate myocardial infarction via inhibiting Notch1 signaling pathway.

M2 macrophages mediate fibrotic scar formation in the early stages after cerebral ischemia in rats

In the central nervous system, the formation of fibrotic scar after injury inhibits axon regeneration and promotes repair. However, the mechanism underlying fibrotic scar formation and regulation remains poorly understood. M2 macrophages regulate fibrotic scar formation after injury to the heart, lung, kidney, and central nervous system. However, it remains to be clarified whether and how M2 macrophages regulate fibrotic scar formation after cerebral ischemia injury. In this study, we found that, in a rat model of cerebral ischemia induced by middle cerebral artery occlusion/reperfusion, fibrosis and macrophage infiltration were apparent in the ischemic core in the early stage of injury(within 14 days of injury). The number of infiltrated macrophages was positively correlated with fibronectin expression. Depletion of circulating monocyte-derived macrophages attenuated fibrotic scar formation. Interleukin 4(IL4) expression was strongly enhanced in the ischemic cerebral tissues, and IL4-induced M2 macrophage polarization promoted fibrotic scar formation in the ischemic core. In addition, macrophage-conditioned medium directly promoted fibroblast proliferation and the production of extracellular matrix proteins in vitro. Further pharmacological and genetic analyses showed that sonic hedgehog secreted by M2 macrophages promoted fibrogenesis in vitro and in vivo, and that this process was mediated by secretion of the key fibrosis-associated regulatory proteins transforming growth factor beta 1 and matrix metalloproteinase 9. Furthermore, IL4-afforded functional restoration on angiogenesis, cell apoptosis, and infarct volume in the ischemic core of cerebral ischemia rats were markedly impaired by treatment with an sonic hedgehog signaling inhibitor, paralleling the extent of fibrosis. Taken together, our findings show that IL4/sonic hedgehog/transforming growth factor beta 1 signaling targeting macrophages regulates the formation of fibrotic scar and is a potential therapeutic target for ischemic stroke.

Brain-derived neurotrophic factor mediates macrophage migration inhibitory factor to protect neurons against oxygen-glucose deprivation

Macrophage migration inhibitory factor(MIF)is a chemokine that plays an essential role in immune system function.Previous studies suggested that MIF protects neurons in ischemic conditions.However,few studies are reported on the role of MIF in neurological recovery after ischemic stroke.The purpose of this study is to identify the molecular mechanism of neuroprotection mediated by MIF.Human neuroblastoma cells were incubated in Dulbecco’s modified Eagle’s medium under oxygen-glucose deprivation(OGD)for 4 hours and then returned to normal aerobic environment for reperfusion(OGD/R).30 ng/mL MIF recombinant(30 ng/mL)or ISO-1(MIF antagonist;50μM)was administered to human neuroblastoma cells.Then cell cultures were assigned to one of four groups:control,OGD/R,OGD/R with MIF,OGD/R with ISO-1.Cell viability was analyzed using WST-1 assay.Expression levels of brain-derived neurotrophic factor(BDNF),microtubule-associated protein 2(MAP2),Caspase-3,Bcl2,and Bax were detected by western blot assay and immunocytochemistry in each group to measure apoptotic activity.WST-1 assay results revealed that compared to the OGD/R group,cell survival rate was significantly higher in the OGD/R with MIF group and lower in the OGD/R with ISO-1 group.Western blot assay and immunocytochemistry results revealed that expression levels of BDNF,Bcl2,and MAP2 were significantly higher,and expression levels of Caspase-3 and Bax were significantly lower in the MIF group than in the OGD/R group.Expression levels of BDNF,Bcl2,and MAP2 were significantly lower,and expression levels of Caspase-3 and Bax were significantly higher in the ISO-1 group than in the OGD/R group.MIF administration promoted neuronal cell survival and induced high expression levels of BDNF,MAP2,and Bcl2(anti-apoptosis)and low expression levels of Caspase-3 and Bax(pro-apoptosis)in an OGD/R model.These results suggest that MIF administration is effective for inducing expression of BDNF and leads to neuroprotection of neuronal cells against hypoxic injury.

Macrophage migration inhibitory factor as a potential prognostic factor in gastric cancer

AIM:To investigate macrophage migration inhibitory factor(MIF) expression and its clinical relevance in gastric cancer,and effects of MIF knockdown on proliferation of gastric cancer cells. METHODS:Tissue microarray containing 117 samples of gastric cancer and adjacent non-cancer normal tissues was studied for MIF expression by immunohistochemistry(IHC) semiquantitatively,and the association of MIF expression with clinical parameters was analyzed. MIF expression in gastric cancer cell lines was detected by reverse transcriptionpolymerase chain reaction(RT-PCR) and Western blot. Two pairs of si RNA targeting the MIF gene(MIF si-1 and MIF si-2) and one pair of scrambled si RNA as a negative control(NC) were designed and chemically synthesized. All si RNAs were transiently transfected in AGS cells with OligofectamineTM to knock down the MIF expression,with the NC group and mock group(OligofectamineTM alone) as controls. At 24,48,and 72 h after transfection,MIF m RNA was analyzed by RTPCR,and MIF and proliferating cell nuclear antigen(PCNA) proteins were detected by Western blot.The proliferative rate of AGS cells was assessed by methylthiazolyl tetrazolium(MTT) assay and colony forming assay.RESULTS:The tissue microarray was informative for IHC staining,in which the MIF expression in gastric cancer tissues was higher than that in adjacent noncancer normal tissues(P < 0.001),and high level of MIF was related to poor tumor differentiation,advanced T stage,advanced tumor stage,lymph node metastasis,and poor patient survival(P < 0.05 for all). After si RNA transfection,MIF m RNA was measured by real-time PCR,and MIF protein and PCNA were assessed by Western blot analysis. We found that compared to the NC group and mock group,MIF expression was knocked down successfully in gastric cancer cells,and PCNA expression was downregulated with MIF knockdown as well. The cell counts and the doubling times were assayed by MTT 4 d after transfection,and colonies formed were assayed by colony forming assay 10 d after transfection; all these showed significant changes in gastric cancer cells transfected with specific si RNA compared with the control si RNA and mock groups(P < 0.001 for all).CONCLUSION:MIF could be of prognostic value in gastric cancer and might be a potential target for small-molecule therapy.

Early treadmill exercise increases macrophage migration inhibitory factor expression after cerebral ischemia/reperfusion

The neuroprotective function of macrophage migration inhibitory factor(MIF) in ischemic stroke was rarely evaluated.This study aimed to investigate the effects of early treadmill exercise on recovery from ischemic stroke and to determine whether these effects are associated with the expression levels of MIF and brain-derived neurotrophic factor(BDNF) in the ischemic area.A total of 40 male Sprague-Dawley rats were randomly assigned to the ischemia and exercise group [middle cerebral artery occlusion(MCAO)-Ex,n = 10),ischemia and sedentary group(MCAO-St,n = 10),sham-surgery and exercise group(Sham-Ex,n= 10),or sham-surgery and sedentary group(Sham-St,n = 10).The MCAO-Ex and MCAO-St groups were subjected to MCAO for 60 minutes,whereas the Sham-Ex and Sham-St groups were subjected to an identical operation without MCAO.Rats in the MCAO-Ex and Sham-Ex groups then ran on a treadmill for 30 minutes once a day for 5 consecutive days.After reperfusion,the hanging time tested by the wire hang test was longer and the relative fractional anisotropy determined by MRI was higher in the peri-infarct region of the MCAO-Ex group compared with the MCAO-St group.The expression levels of MIF and BDNF in the peri-infarct region were upregulated in the MCAO-Ex group.Increased MIF and BDNF levels were positively correlated with relative fractional anisotropy changes in the peri-infarct region.There was no significant difference in the levels of MIF and BDNF in the peri-infarct region between the Sham-Ex and Sham-St groups.Our study demonstrated that early exercise(initiated 48 hours after the MCAO) could improve motor and neuronal recovery after ischemic stroke.Furthermore,the increased levels of MIF and BDNF in the peri-infarct region(penumbra) may be one of the mechanisms of enhanced neurological function recovery.All experiments were approved by the Institutional Animal Care and Use Committee in Asan Medical Center in South Korea(2016-12-126).

IMMUNOHISTOCHEMICAL OBSERVATION OF MACROPHAGE COLONY STIMULATING FACTOR AND ITS RECEPTOR IN BREAST CANCER AND HEPATOMA TISSUES

Objective: To study the potential role of cellular macrophage colony-stimulating factor (cM-CSF) and cellular macrophage colony-stimulating factor receptor (cM-CSF-R) with breast cancer and hepatoma and search the way for clinical application. Methods: Frozen surgical specimens from 48 breast cancer patients, including 29 cases of histological grade II and 19 eases of grade III, and 16 hepatoma patients were investigated by Avidin Biotin Complex (ABC) immunohistochemical assay with anti-M-CSF monoclonal antibody (Mab) and anti-M-CSF-R Mab. Pathohistological examination was performed as well. Results: cM-CSF and cM-CSF-R were detected in tested specimens. The expression levels of cM-CSF and cM-CSF-R in grade III group were higher than in grade II group and more higher than control group hyperplasia of breast. Hepatoma tissues also showed higher expression level of cM-CSF and cM-CSF-R than normal adult and fetal liver. Conclusion: Breast cancer and hepatoma tissues presented higher expression levels of cM-CSF and cM-CSF-R than control and expression level might be related with tumor’s process.

Serum and ascites levels of macrophage migration inhibitory factor, TNF-α and IL-6 in patients with chronic virus hepatitis B and hepatitis cirrhosis

Objective: To study the potential role of macrophage migration inhibitory factor (MIF), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in the development of chronic virus hepatitis B (CH) and hepatitis cirrhosis (HC). Methods: The serum concentrations of MIF, TNF-α and IL-6 in 18 patients with chronic virus hepatitis B and in 14 patients with hepatitis cirrhosis without as- citic fluid, and the serum and ascites cytokine con- centrations in 22 HC patients with ascitic fluid were detected by enzyme linked immunity sorbed assay. Results: The cytokine concentrations of the patients were significantly higher than those of the controls. The serum levels of MIF, TNF-α and IL-6 of the 22 patients with ascitic fluid were higer than those of 14 HC patients without ascites. In the 18 patients with CH, the serum cytokine concentrations were the low- est. The serum cytokine concentrations of the 22 HC patients with ascites were significantly higher than those of the 14 HC patients without ascites (P< 0. 01). Their serum cytokine concentrations were sig- nificantly higher than those in the 18 patients with CH (P<0. 01). The concentration of IL-6 in ascites was the highest among all the groups. The serum le- vels of MIF, TNF-α and IL-6 are correlated with al- anine aminotransferase (ALT) in the patients with CH, but not in those with HC with or without asci- tes. Conclusions: These results indicated that MIF, TNF- α and IL-6 may participate in the pathological process of CH and cirrhosis, that IL-6 seems to play an important role in ascites formation, and that se- rum levels of MIF, TNF-α and IL-6 appear to reflect the severity of tissue injury in HBV disease.

CO-EXPRESSION OF MACROPHAGE COLONY-STIMULATING FACTOR WITH ITS RECEPTOR IN HUMAN HEPATOMA CELLS AND ITS POTENTIAL ROLES

Objective: To investigate the potential role of macrophage colony-stimulating factor (M-CSF) and macrophage colony-stimulating factor receptor (M-CSF-R) on the growth of human hepatoma cells. Methods: Specimens of different origin, including tissues of human hepatocellular carcinoma (HCC), human fetal liver (FL) and normal liver (NL), the hepatoma cell lines, as well as the peripheral blood mononuclear cells (PBMC) from patients with HCC or liver metastatic tumor (LMT), were used to detect the expression levels of M-CSF and M-CSF-R by ABC immunohistochemistry staining and reverse transcription polymerase chain reaction methods the expression levels of M-CSF and M-CSF-R. Influence of monoclonal antibody against M-CSF (B5) or M-CSF-R (RE2) on proliferation ability of hepatoma cell linesin vitro was also studied. Results: The results showed that hepatoma tissues produced elevated levels of both M-CSF and M-CSF-R compared with those of fetal liver (P<0.001). The M-CSF/M-CSF-R expression levels of PBMC from hepatoma patients were higher than those of LMT patients (P<0.01,P<0.05) and the normal people (P<0.001). The hepatoma cell lines showed strong positive for M-CSF and M-CSF-R production. Both B5 and RE2 displayed a dose-dependent inhibitory effect on the growth and proliferation of hepatoma cells. Conclusion: The study indicates a co-expression model for M-CSF-R in hepatoma cells, suggesting an involvement of M-CSF/M-CSF-R in growth signaling of those malignant cells. The M-CSF/M-CSF-R seems to function through an autonomy mechanism in human hepatoma.

Cloning and mRNA expression of macrophage migration inhibitory factor (MIF) gene of large yellow croaker (P seudosciaena crocea)

Mammalian macrophage migration inhibitory factor （MIF） plays an important role as an indispensable mediator in the pathogenesis of inflammatory disease like septicemia, but little is known about the role of MIF homologue in fish septicemia. The authors have cloned the MIF homologue in large yellow croaker Pseudosciaena crocea （LycMIF） using RACE approach. The full-length cDNA of LycMIF was 634 bases and contained an ORF of 345 bases encoding a protein of 115 amino acid residues. As demonstrated by RT-PCR and QRT-PCR assay, MIF mRNAs were constitutively expressed in 11 selected tissues and were abundant in brain and liver. Moreover, the LycMIF transcripts in the liver and head kidney were responsive to bacteria infection and could be significantly up-regulated. Our results provide the first direct evidence that fish MIF was implicated in pathogenesis of fish vibrosis and play an important role in response to bacteria infection.

ANTIGEN ASSOCIATION OF J6-1 CELL MEMBRANE ASSOCIATEDFACTOR RECEPTOR WITH MACROPHAGE COLONYSTIMULATING FACTOR RECEPTOR

Objective: To verify the antigen association of MAF-J6-1 receptor with M-CSFR and to further study the role of M-CSF and its receptor mediated juxtacrine in promoting leukemic cell proliferation. Methods: Monoclonal antibody (McAb) of MAF-J6-1R RE2 and polyclonal antibody (PolyAb) of rhM-CSFR were prepared. The specificity of McAb RE2 to M-CSFR was confirmed by indirect ELISA, cross-neutralizing assay with J6-1 cell colony formation and neutralization test by ELISA. Results: the reactive activity of purified RE2 to M-CSFR was over 1: 16000. The inhibitory activity of M-CSFR and MAF-J6-1R could be blocked by RE2 and anti-M-CSFR antibody. The reactivity of RE2 to M-CSFR could be reduced by M-CSFR. Conclusion: The specificity of RE2 to M-CSFR was confirmed and the antigen association of MAF-J6-1R with M-CSFR was proved. It suggests that M-CSF and its receptor mediated auto-juxtacrine stimulation could be an operative mechanism in either leukemia or nonhematological malignancies.

Upregulation of macrophage migration inhibitory factor and calgizzarin by androgen in TM4 mouse Sertoli cells

Aim： To identify proteins induced by androgen in Sertoli cells during spermatogenesis. Methods： We analyzed protein profiles in TM4 Sertoli cells treated with dihydrotestosterone （DHT） using surface enhanced laser desorption ionization time-of-flight mass spectrometry （SELDI-TOF-MS）. Results： We found increases in the expression of a 5.0-kDa protein at 15 min, an 11.3-kDa protein at 24 h and 4.3 kDa, 5.7 kDa, 5.8 kDa, 9.95 kDa and 9.98 kDa proteins at 48 h after the treatment. In contrast, the expression of 6.3 kDa and 8.6 kDa proteins decreased at 30 min, and 4.9 kDa, 5.0 kDa, 12.4 kDa and 19.8 kDa proteins at 48 h after the treatment. The ll.3-kDa protein was identified as macrophage migration inhibitory factor （MIF） known to having various functions. The 9.98-kDa protein was identified as calgizzarin related to calcium channels. The timing of their expression suggests that MIF and calgizzarin are involved in late regulation of spermatogenesis in Sertoli cells by androgen. Conclusion： MIF and calgizzarin are two important androgen-responsive proteins produced by Sertoli cells and they might play a role in regulating spermatogenesis.

Macrophage migration inhibitory factor regulates proliferation of gastric cancer cells via the PI3K/Akt pathway

AIM:To investigate the effects of macrophage migration inhibitory factor (MIF) on proliferation of human gastric cancer MGC-803 cells and expression of cyclin D1 and p27Kip1 in them,and further determine whether the effects are related to the PI3K/Akt signal transduction pathway. METHODS:Gastric cancer MGC-803 cells were cultured and then treated with 50 μg/L recombinant human MIF (rhMIF) with and without a PI3K inhibitor,LY294002 (25 μmol/L). MTT assay was used to detect the prolifer-ation of MGC-803 cells. Cell cycle was detected by flow cytometry. Expression of cyclin D1 and p27Kip1 mRNA was by reverse transcription-polymerase chain reaction. Protein expression of phosphorylated Akt (p-Akt),Akt,cyclin D1 and p27Kip1 was examined by immunocyto-chemistry and Western blotting. RESULTS:rhMIF signifi cantly stimulated the prolifera-tion of MGC-803 cells and cell cycle progression from G1 phase to S phase in a concentration-and time-de-pendent manner. After the MGC-803 cells were treated with rhMIF for 24 h,the expression of cyclin D1 was signifi cantly up-regulated compared with the cells not treated with rhMIF at both mRNA and protein levels(0.97 ± 0.02 vs 0.74 ± 0.01,P = 0.002; 0.98 ± 0.05 vs 0.69 ± 0.04,P = 0.003). The p27Kip1 was down-regulated but only statistically significant at the protein level. rhMIF significantly increased the expression of p-Akt,which reached the peak at 30 min,but did not affect the expression of Akt. However,LY294002 inhibited all the effects of rhMIF.CONCLUSION:Macrophage MIF increases the proliferation of gastric cancer cells,induces the expression of cyclin D1 at the transcriptional level and inhibits the expression of p27Kip1 at the post-transcriptional level via the PI3K/Akt pathway.

Expression of macrophage migration inhibitory factor in Aspergillus fumigatus keratitis

AIM: To investigate the expression of macrophage migration inhibitory factor(MIF) and detect its role in the innate immune response of fungal keratitis(FK). METHODS: We collected the paraffin-embedded cornea tissues from 10 FK and 6 ocular trauma patients to explore the MIF expression by immunohistochemistry. Then we cultured telomease-immortalized human corneal epithelial cells(THCEs), stimulated by the hyphae suspension of Aspergillus fumigatus(A. fumigatus) to detect the change of MIF with or without the pretreatment of MIF inhibitor [4-Iodo-6-phenylpyrimidine(4-IPP)] by real-time polymerase chain reaction(PCR). The protein level of MIF was also tested by immunohistochemistry, and the level of tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6) mRNA were compared between normal, hyphae stimulated and 4-IPP pretreated groups by real-time PCR to study the influence of MIF on the expression of TNF-α and IL-6. Corneal severity of rats' FK models was documented by clinical scores, and real-time PCR. Western blot and immunohistochemistry were used to test the expression of MIF, TNF-α and IL-6 in rats' corneas.RESULTS: In the corneas of FK patients, there was much stronger expression of MIF than that in the normal group showed by immunohistochemistry. In cultured THCEs stimulated by A. fumigatus, the expression of MIF became stronger in both immunohistochemistry and PCR at 16, 24, 32 and 48 h post infection(p.i.; P<0.01, P<0.01, P<0.01, P<0.05). After pretreated with 4-IPP, the expression of MIF reduced at 4, 8, 16 h p.i.(P<0.05, P<0.05, P<0.05) and the downstream TNF-α and IL-6 decreased obviously(P<0.05, P<0.01). In rats with A. fumigatus keratitis, the relative mRNA and protein level of MIF increased than thosein the normal group by PCR(at 1 d: P<0.01, 3 d: P<0.01, 5 d: P<0.01), Western blot and immunohistochemistry. After blocked MIF with 4-IPP, the clinical outcomes of rat keratitis showed markedly reduced inflammatory response(P<0.01), with TNF-α and IL-6 decreased in accordance with those in THCEs by PCR(P<0.05, P<0.01). CONCLUSION: The expression of MIF increased significantly in FK patients, THCEs and rats stimulated by A. fumigatus. After blocked with 4-IPP, the expression of MIF reduced, and so did its downstream cytokines: TNF-α and IL-6. The inflammation reaction of the rats' corneas lightened after pretreated with 4-IPP. MIF may play a role in the innate immune response of the corneal resistance against A. fumigatus.

Macrophage colony-stimulating factor expressed in non-cancer tissues provides predictive powers for recurrence in hepatocellular carcinoma

AIM To investigate the role of macrophage colony-stimulating factor(M-CSF) in patients with hepatocellular carcinoma(HCC) after surgery. METHODS Expression of M-CSF, distribution of M2 macrophages(Mφs), and angiogenesis were assessed in the liver, including tumors and peritumoral liver tissues. The prognostic power of these factors was assessed. Mouse isolated hepatic Mφs or monocytes were cultured with media containing M-CSF. The concentration of vascular endothelial growth factor(VEGF) in media was assessed. Furthermore, the role of the M-CSF-matured hepatic Mφs on proliferation of the vascular endothelial cell(VEC) was investigated. RESULTS A strong correlation between the expressions of M-CSF and CD163 was observed in the peritumoral area. Also, groups with high density of M-CSF, CD163 or CD31 showed a significantly shorter time to recurrence(TTR) than low density groups. Multivariate analysis revealedthe expression of M-CSF or hepatic M2Mφs in the peritumoral area as the most crucial factor responsible for shorter TTR. Moreover, the expression of M-CSF and hepatic M2Mφs in the peritumoral area had better predictable power of overall survival. Values of VEGF in culture media were significantly greater in the hepatic Mφs compared with the monocytes. Proliferation of the VEC was greatest in the cells co-cultured with hepatic Mφs when M-CSF was present in media.CONCLUSION M-CSF increases hepatocarcinogenesis, most likely by enhancing an angiogenic factor derived from hepatic Mφ and could be a useful target for therapy against HCC.

D-dopachrome tautomerase from Japanese sea bass(Lateolabrax japonicus) is a chemokine-like cytokine and functional homolog of macrophage migration inhibitory factor

D-dopachrome tautomerase(DDT),a member of the macrophage migration inhibitory factor(MIF)protein superfamily,is a newly described cytokine with chemokine-like characteristics.However,research on fish DDT remains limited.In this study,we identified a DDT homolog(LjDDT)from the Japanese sea bass,Lateolabrax japonicus.Sequence analysis showed that LjDDT had typical sequence features of known DDT and MIF homologs and was most closely related to DDT of rock bream(Oplegnathus fasciatus).LjDDT transcripts were detected in all tested tissues of healthy Japanese sea bass,with the highest expression found in the liver.Upon infection with Vibrio harveyi,LjDDT transcripts were significantly down-regulated in the three tested tissues,including the liver,spleen,and head kidney.Recombinant LjDDT(rLjDDT)and the corresponding antibody(anti-rLjDDT)were subsequently prepared.The administration of 100μg/g anti-rLjDDT had a statistically significant protective effect on the survival of V.harveyi-infected fish.Moreover,rLjDDT was able to induce the migration of monocytes/macrophages(MO/MФ)and lymphocytes both in vitro and in vivo,but without significant influence on the migration of neutrophils.rLjDDT exhibited chemotactic activity for lipopolysaccharide(LPS)-stimulated M1-type MO/MΦin vitro,but not for cAMP-stimulated M2-type MO/MΦ.Furthermore,the knockdown of LjCD74,but not LjCXCR4,significantly down-regulated the rLjDDT-enhanced migration of MO/MΦand relieved the rLjMIF-inhibited migration of MO/MΦ.These results indicate that LjCD74 may be the major chemotactic receptor of LjDDT and LjMIF in Japanese sea bass MO/MΦ.Combined rLjDDT+rLjMIF treatment had no significant effect on the migration of MsiRNA,LjCD74si-,or LjCXCR4sitreated MO/MΦcompared to the control group,suggesting that the roles of LjDDT and LjMIF may be antagonistic.In conclusion,our study demonstrates for the first time that DDT may play a role in the immune responses of fish against bacterial infection through chemotactic recruitment of MO/MΦvia mediation of CD74 as an antagonist of MIF.

DETERMINATION OF SERUM SOLUBLE MACROPHAGE COLONY-STIMULATING FACTOR RECEPTOR LEVELS IN PATIENTS WITH HEMATOLOGICAL DISEASES

Objective: To investigate the serum levels of soluble macrophage colony-stimulating factor receptor (M-CSFsR) in normal subjects and patients with hematological diseases and its clinical implications in hematological diseases. Methods: The concentration of M-CSFsR was determined by ELISA. The serum M-CSFsR was identified and characterized by immunoprecipitation and Western blotting. Results: The mean serum level of M-CSFsR of 123 normal individuals was 0.48 ng/ml ± 0.41 ng/ml. Immunoprecipitation and Western blotting assay revealed a ～ 90kD band of serum M-CSFsR. The mean serum M-CSFsR level of 60 patients with acute lymphoblastic leukemia (ALL), 36 patients with acute myeloblastic leukemia (AML), 13 patients with myelodysplastic syndrome (MDS) and 42 patients with aplastic anemia (AA) .were 0.22 ng/ml±0.23 ng/ml, 0.17 ng/ml±0.16 ng/ml, 0.19 ng/ml±0.16 ng/ml and 0.23 ng/ml±0.21 ng/ml, respectively, which were significantly lower than that of normal subjects (P=0.002 ,P<0.0001,P<0.0001 andP<0.0001). The mean serum M-CSFsR level of 51 idiopathic thrombocytopenic purpura (ITP) patients was significantly higher than that of normal subjects (2.05 ng/ml±2.75 ng/ml,P<0.0001). Conclusion: The serum M-CSFsR levels of patients with ALL, AML, MDS and AA were significantly lower, while the level of patients with ITP was significantly higher than that of normal individuals. Patients with severe ITP (platelet count<30×l09/L) had the highest M-CSFsR level. It suggested that the abnormal levels of serum M-CSFsR may associate with some hematological diseases and may contribute to the pathological process.