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.

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 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.

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.

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.

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.

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.

Association of the macrophage migration inhibitory factor promoter polymorphisms with benign lymphoepithelial lesion of lacrimal gland

AIM： To identify the association of the macrophage migration inhibitory factor （MIF） gene polymorphism with the susceptibility of benign lymphoepithelial lesions （BLEL） of the lacrimal gland. METHODS： A total of 40 BLEL of lacrimal gland cases were matched with 40 healthy subjects （HS）. Extraction the plasma and whole blood DNA of patients of lacrimal gland BLEL and HS. Elisa and polymerase chain reaction was used to determine in plasma contents of MIF and MIF gene SNP-173G〉C and STR -794 CATT（8） polymorphism, respectively. RESULTS： The MIF levels in plasma were significantly higher in patients with lacrimal gland BI.EL versus HS （P〈0.001）. The -173 G〉C MIF polymorphism was significantly associated with lacrimal gland BLEL, with a significantly higher frequency of the C allele in lacrimal gland BLEL patients compared with HS （OR=2.38, 95% C1=1.07-5.31, P=0.032）, and the -173 C/x is more frequent in patients than in HS, P=0.037. Besides, we found that the carriage rate of the MIF -173C/x is associated with higher plasma levels of MIF in the BLEI. of lacrimal gland. CONCLUSION： MIF -173G/C variants play an insidious role in susceptibility of BLEL of lacrimal gland. Otherwise,there is no statistically significant correlation exists between MIF-794 CATT （） and BLEL of lacrimal gland.

Macrophage migration inhibitory factor decreased T-type Ca^(2+) channel current through activating Src

Aims T-type Ca2+ current(ICaT)plays an important role in the pathogenesis of atrial fibrillation（AF）.The present study sought to investigate the role of Macrophage migration inhibitory factor（MIF）,a pleiotropic cytokine,in the regulation of T-type Ca2+ channel in atrium myocytes.Methods We used whole-cell voltage-clamp technique and biochemical assays to study the regulation and expression of ICa,T in mouse atrium myocytes（HL-1 cells）.Results Serum MIF concentrations was slightly increased in patients with AF compared to sinus rhythm（SR） controls.In cultured HL-1 cells, significant amounts of MIF were produced in response to hydrogen peroxide（H2O2）,but not AngiotensinⅡ（AngⅡ）. Mouse recombinant MIF（rMIF）（20 or 40 nM,24 h） suppressed peak ICa,T by-38%and-60%in a concentration-dependent manner,impaired the voltage-dependent activation of ICa,T,and down-regulated of TCC alG mRNA.Src inhibitors genistein and PPl significantly enhanced ICaT.The depression of ICa,T induced by rMIF could be reversed by genistein and PP1.Conclusions MIFis involved in the pathogenesis of AF,probably by decreasing ICa,T through impairment of the channel function and activation of c-Src kinases in atrium myocytes.

Moxibustion of Zusanli(ST36)and Shenshu(BL23)alleviates the inflammation of rheumatoid arthritis in rats through regulating macrophage migration inhibitory factor/glucocorticoids signaling

OBJECTIVE:To test the hypothesis that moxibustion may inhibit rheumatoid arthritis(RA)synovial inflammation by regulating the expression of macrophage migration inhibitory factor(MIF)/glucocorticoids(GCs).METHODS:Fifty male Sprague-Dawley rats were randomly divided into five groups(n=10 each):blank Control(CON)group,RA Model(RA)group,Moxibustion(MOX)group,MIF inhibitor(S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester(ISO-1)group,and Moxibustion+MIF inhibitor ISO-1(MOX+ISO-1)group.Rats in the ISO-1 group and ISO-1+MOX group were intraperitoneally injected with the inhibitor ISO-1.The rats in the RA group,ISO-1 group,MOX group,and ISO-1+MOX group were injected with Freund's complete adjuvant(FCA)in the right hind footpad to establish an experimental RA rat model.In the MOX group and MOX+ISO-1 group,rats were treated with Moxa.The thickness of the footpads of the rats in each group was measured at three-time points before,after modeling and after moxibustion treatment.The contents of serum MIF,corticosterone(CORT),tumor necrosis factor-α(TNF-α)and interleukin-1β(IL-1β)were detected by enzyme-linked immunosorbent assay;and the contents of synovial MIF were detected by Western blot.Hematoxylin-eosin(HE)staining method was used to observe the pathological changes of synovial tissue under a section light microscope,and pathological scoring was performed according to the grading standard of the degree of synovial tissue disease.RESULTS:Moxibustion was found to reduce the level of MIF and alleviate inflammation in RA rats in this study.In addition,after inhibiting the expression of MIF,the level of CORT increased,and the level of TNF-α decreased.Treating RA rats with inhibited MIF by moxibustion,the level of CORT was almost unchanged,but the level of TNF-α further decreased.The correlation analysis data suggested that MIF was positively related to the expression of TNF-α and negatively correlated with the expression of CORT.CONCLUSION:Reducing MIF to increase CORT and decrease TNF-α by moxibustion treatment in RA.MIF may be a factor for moxibustion to regulate the expression of CORT,but the expression of TNF-α is due to the incomplete regulation of the MIF.This study added to the body of evidence pointing to moxibustion's antiinflammatory mechanism in the treatment of RA.

Pathogenesis of coxsackievirus B3-induced myocarditis： role of macrophage migration inhibitory factor

Background Macrophage migration inhibitory factor （MIF） is an upstream regulator in immune and inflammatory responses.However,its role in viral myocarditis remains unknown.In this study,we investigated the role of the MIF in coxsackievirus B3 （CVB3）-induced myocarditis.Methods Mice were randomized into two groups receiving either Eagle＇s minimal essential medium （EMEM,control group） or virus solution （infected group）.Subsets of mice in the infected group were sacrificed on days 3,7,14 and 28 after inoculation.Expression of MIF was detected using an enzyme-linked immunosorbent assay （ELISA）,reverse transcription polymerase chain reaction and immunohistochemistry.A neutralizing antibody （Ab） to MIF was injected intraperitoneally from day 0 to 7 after inoculation.Disease severity was estimated by histopathology of the heart and by the heart weight to body weight ratio,and the interleukin-1β （IL-1β） and tumor necrosis factor α （TNF-α） in the myocardium were measured by ELISA on day 14.Results The serum MIF concentration and expression levels of myocardial MIF mRNA and protein were significantly elevated in mice on days 7 and 14 post-infection.The survival rate was markedly higher and disease severity was obviously less in mice treated with anti-MIF Ab.Furthermore,MIF blockade significantly decreased the IL-1β and TNF-α in the myocarditic heart.Conclusion These results demonstrate that MIF is an important naturally occurring inflammatory cytokine in CVB3-induced myocarditis,and anti-MIF Ab may lessen the inflammatory response.

The effect of Helicobacter pylori infection on expression of macrophage migration inhibitory factor by T cells and macrophages in gastric mucosa

Background Macrophage migration inhibitory factor (MIF) plays a pivotal role in inflammatory and immune-mediated diseases. However, its molecular function and role in gastrointestinal diseases has rarely been studied and thus warrants an in-depth investigation. This study was designed and conducted to determine MIF expression in Helicobacter pylori (H. pylori)-induced gastritis and the effect of H. pylori on MIF expression in monocytes in vitro. Methods Gastric specimens of 62 patients with chronic gastritis were obtained through endoscopic biopsies. Both gastric antrum and body were examined for histopathologic changes. Positive H. pylori was determined through rapid urease test and histopathological examination. A patient was classified as H. pylori positive if both tests showed positive results. The updated Sydney System was employed to assess the severity and activity of gastric inflammation. Double immunoassaying for MIF/T-cells (CD45RO) and MIF/macrophage (KP1), as well as in situ hybridization for the expression of MIF mRNA were used for the current analysis. THP-1, a monocyte cell line, was co-incubated with H. pylori strains (ATCC26695) and subsequently examined for the expression of MIF protein and mRNA by enzyme linked immunosorbent assay and retrospective transcription-polymerase chain reaction, respectively. Results Among 62 patients with chronic gastritis, significant increase in total T-cells, MIF+ T-cells, total macrophages, MIF+ macrophages and MIF mRNA+ cells was observed in 42 H. pylori positive patients compared to H. pylori negative patients. Moreover, the increase of the MIF mRNA+ cells was highly correlated with the severity of the disease(number of MIF mRNA+cells/mm2, mild: 2834±382, moderate: 3569±123, severe: 3881±118, P<0.01). In vitro results showed that the expression of MIF protein and mRNA in monocytes was significantly increased after incubation with H. pylori strains.Conclusions Overexpression of MIF is common in H. pylori-induced gastric inflammation, which suggests MIF may play an important role in the initiation and development of this disease.

Serum macrophage migration inhibitory factor as a potential biomarker to evaluate therapeutic response in patients with allergic asthma:an exploratory study

Background:Previous studies have shown that macrophage migration inhibitory factor(MIF)is involved in the pathogenesis of asthma.This study aimed to investigate whether serum MIF reflects a therapeutic response in allergic asthma.Methods:We enrolled 30 asthmatic patients with mild-to-moderate exacerbations and 20 healthy controls,analyzing the parameter levels of serum MIF,serum total immunoglobulin E(tIgE),peripheral blood eosinophil percentage(EOS%),and fractional exhaled nitric oxide(FeNO).Lung function indices were used to identify disease severity and therapeutic response.Results:Our study showed that all measured parameters in patients were at higher levels than those of controls.After one week of treatment,most parameter levels decreased significantly except for serum tIgE.Furthermore,we found that serum MIF positively correlated with EOS%as well as FeNO,but negatively correlated with lung function indices.Receiver operator characteristic(ROC)curve analysis indicated that among the parameters,serum MIF exhibited a higher capacity to evaluate therapeutic response.The area under the curve(AUC)of MIF was 0.931,with a sensitivity of 0.967 and a specificity of 0.800.Conclusions:Our results suggested that serum MIF may serve as a potential biomarker for evaluating therapeutic response in allergic asthma with mild-to-moderate exacerbations.

Macrophage migration inhibitory factor promotes the expression of GLUT4 glucose transporter through MEF2 and Zac1 in cardiomyocytes

Background Evidences show that macrophage migration inhibitory factor （MIF） and the subtype 4 form of glucose transporter （GLUT4） participate in the process of diabetic cardiomyopathy （DCM）, however the effect of MIF on modulation of GLUT4 expression is not clear. The present study aimed to investigate the mechanism underlying the modulation of GLUT4 by MIF in cardiomyocytes. Methods The neonatal C57BL/ 6 mouse ventricular cardiomyocytes （NMVCs） were isolated for in vitro studies. Expressions of GLUT4 and the candidate GLUT4 regulation associated transcription factors in mouse myocardium and NMVCs were determined by quantitative reverse transcription PCR （qRT-PCR）, and Western blotting, respectively. The effects of screened transcription factors on mediating MIF-promoted GLUT4 expression were verified by RNA interference （RNAi） assay. Results MIF was upregulated, but GLUT4 was decreased in the diabetic myocardium of the db/db mice. MIF could enhance glucose uptake of the cultured neonatal mouse cardiomyocytes with significant upregulation of GLUT4. RT-qPCR and Western-blot assays showed that MEF2A, -2C, -2D and Zacl were significantly up-regulated in MIF-treated NMVCs. Knockdown of Zacl, MEF2A, -2C, and -2D could markedly inhibit glucose uptake and GLUT4 expression in cardiomyocytes. Moreover, Zacl was also shown directly regulated by MEF2A, -2C, and -2D, respectively. Conclusions Transcription factors Zacl and MEF2 mediate MIF-promoted GLUT4 expression in cardiomyocytes.

Macrophage migration inhibitory factor suppresses angiotensinⅡ-induced expression of fibrosis-associated genes by inactivating Smad3 and activating Nrf2 in cardiac fibroblasts

Background Macrophage migration inhibitory factor （MIF） is a key pro-inflammatory cytokine, exhibiting antioxidant properties. However, the role of MIF in cardiac fibrosis is not well known. In the present study, the effects of MIF on Smad3 and Nrf2 signalings in cardiac fibroblasts were investigated. Methods Cardiac fibroblasts were isolated from 1-3 days old C57BL/6 mice, and the cardiac fibroblasts from passage 2 to 4 were used in this study. Expression of fibrosis-associated Collal, Col3al and oL-SMA in mouse cardiac fibroblasts was de- tected by immunofluorescence staining and Western-blot assay, respectively. Intracellular oxidants in mouse car- diac fibroblasts were measured by using the probe dichlorofluoroscindiacetate （DCFH-DA） under confocal mi- croscopy. Western-blot assay was also used to detect Smad3 and Nrf2, antioxidant proteins, MLL and HCF-1 in mouse cardiac fibroblasts. Results Immunofluorescence staining and Western- blot assay showed that MIF could markedly inhibit fibrosis-associated Collal, Col3al and oL-SMA expression in cardiac fibroblasts. DCFH- DA staining revealed that MIF can efficiently decrease reactive oxygen species （ROS） level in Ang-II-induced cardiac fibroblasts. Additionally, Smad3 activation was inhibited, but transcription factor Nrf2 and the downstream antioxidant genes, including HO-1, SOD-l, SOD2, Trx-2 and e-NOS, were increased in MIF-treated cardiac fibroblasts. MLL and HCF-lwere up-regulated by MIF, and either MLL knockdown or HCF-1 knock- down could consistently suppress Nrf2 expression in cardiac fibroblasts. Conclusions MIF possesses anti-fibro- sis effect by inactivating Smad3 and activating Nrf2 in cardiac fibroblasts.

Involvement of macrophage migration inhibitory factor in pathogenesis of atrial fibrillation as a redox-sensitive cytokine

Macrophage migration inhibitory factor tory processes,and inflammation is known to play an （MIF） is a pleiotropic cytokine that controls inflamma important role in the pathogenesis of atrial fibrillation （AF）. The present study sought to investigate whether MIF played an important role in the pathogenesis of AF. Methods MIF protein and mRNA levels in specimens of human right atrial appendage（from patients with AF or sinus rhythm） or atrium myocytes （HL-1 cells） were assayed using enzyme-linked immunosorbent assay （ELISA）, real time PCR and Western blot, respectively. Results MIF expression levels were increased in AF when compared to SR. In cultured HL-1 cells, significant amounts of MIF were produced in response to hydrogen peroxide （H2O2）. H2O2-induced MIF production increased in a dose-dependent manner and was completely abolished in the presence of catalase. The H2O2-induced MIF production was completely inhibited by tyrosine kinase inhibitor genistein and PP1. Conclusions These results implicate MIF might be involved in the pathogensis of AF as a redox-sensitive cytokine.

Integrative omics analysis identifies macrophage migration inhibitory factor signaling pathways underlying human hepatic fibrogenesis and fibrosis

The genetic basis underlying liver fibrosis remains largely unknown.We conducted a study to identify genetic alleles and underlying pathways associated with hepatic fibrogenesis and fibrosis at the genome-wide level in 121 human livers.By accepting a liberal significance level of P<1e-4,we identified 73 and 71 candidate loci respectively affecting the variability in alpha-smooth muscle actin(a-SMA)levels(fibrogenesis)and total collagen content(fibrosis).The top genetic loci associated with the two markers were BAZA1 and NOL10 for a-SMA expression and FAM46A for total collagen content(P<1e-6).We further investigated the relationship between the candidate loci and the nearby gene transcription levels(cis-expression quantitative trait loci)in the same liver samples.We found that 44 candidate loci for a-SMA expression and 44 for total collagen content were also associated with the transcription of the nearby genes(P<0.05).Pathway analyses of these genes indicated that macrophage migration inhibitory factor(MIF)related pathway is significantly associated with fibrogenesis and fibrosis,though different genes were enriched for each marker.The association between the single nucleotide polymorphisms,MIF and a-SMA showed that decreased MIF expression is correlated with increased a-SMA expression,suggesting that variations in MIF locus might affect the susceptibility of fibrogenesis through controlling MIF gene expression.In summary,our study identified candidate alleles and pathways underlying both fibrogenesis and fibrosis in human livers.Our bioinformatics analyses suggested MIF pathway as a strong candidate involved in liver fibrosis,thus further investigation for the role of the MIF pathway in liver fibrosis is warranted.The study was reviewed and approved by the Institutional Review Board(IRB)of Wayne State University(approval No.201842)on May 17,2018.

Macrophage migration inhibitory factor protects bone marrow mesenchymal stem cells from hypoxia/ischemia-induced apoptosis by regulating lncRNA

Objective:This research was performed to explore the effect of macrophage migration inhibitory factor(MIF)on the apoptosis of bone marrow mesenchymal stem cells(BMSCs)in ischemia and hypoxia environments.Methods:The cell viability of BMSCs incubated under hypoxia/ischemia(H/I)conditions with or without pretreatment with MIF or triglycidyl isocyanurate(TGIC)was detected using cell counting kit-8(CCK-8)analysis.Plasmids containing long noncoding RNA(lncRNA)maternally expressed gene 3(MEG3)orβ-catenin small interfering RNA(siRNA)were used to overexpress or downregulate the corresponding gene,and the p53 signaling pathway was activated by pretreatment with TGIC.The influences of MIF,overexpression of lncRNA MEG3,activation of the p53 signaling pathway,and silencing ofβ-catenin on H/I-induced apoptosis of BMSCs were revealed by western blotting,flow cytometry,and terminal deoxynucleotidyl transferase(TdT)-mediated dUTP nick-end labeling(TUNEL)staining.Results:From the results of CCK-8 assay,western blotting,and flow cytometry,pretreatment with MIF significantly decreased the H/I-induced apoptosis of BMSCs.This effect was inhibited when lncRNA MEG3 was overexpressed by plasmids containing MEG3.The p53 signaling pathway was activated by TGIC,andβ-catenin was silenced by siRNA.From western blot results,the expression levels ofβ-catenin in the nucleus and phosphorylated p53(p-p53)were downregulated and upregulated,respectively,when the lncRNA MEG3 was overexpressed.Through flow cytometry,MIF was also shown to significantly alleviate the increased reactive oxygen species(ROS)level of BMSCs caused by H/I.Conclusions:In summary,we conclude that MIF protected BMSCs from H/I-induced apoptosis by downregulating the lncRNA MEG3/p53 signaling pathway,activating the Wnt/β-catenin signaling pathway,and decreasing ROS levels.

Design of Agents Interacting with Immunoregulating Proteins:Potential Inhibitors of the Phenylpyruvate Tautomerase Activity Catalysed by Macrophage Migration Inhibitory Factor (MIF)

The macrophage migration inhibitory factor has been implicated in a number ofimmune and inflammatory processes. MIF presents particular opportunities for drug design anddevelopment with potential therapeutic applications. Drug design strategies taking intoconsideration of specific stereochemical and tautomeric requirements in the interaction of MIF withsubstrates and inhibitors allow several novel structures to be designed. Our investigationssuccessfully explored the tautomeric and stereochemical aspects of new compounds of the2-phenylpyruvic acid type, both experimentally, through synthesis and structural investigations andcomputationally, through molecular mechanics and quantum mechanics calculations.

Upregulation of miR-29b contributes to the anti-fibrotic effect of macrophage migration inhibitory factor in diabetic myocardial fibrosis

Background Macrophage migration inhibitory factor （MIF） possesses proinflammatory function when secreted from the cells, and it also exhibits antioxidant properties based on its intrinsic oxidoreductase activity. However, the role of MIF in cardiac fibrosis is not well known. In the present study, the effect of MIF on fibrosis-associated gene expression and the underlying mechanism were examined. Methods The collagen content in mouse myocardium was detected by Masson staining. Expressions of MIF and fibrosis-associated Collal, Col3al and α-SMA in mouse myocardium or mouse cardiac fibroblasts were detected by quantitative real-time PCR and Western blot assay, respectively. Mature miR-29b expressions in mouse myocardium and cardiac fibroblasts were determined by real-time PCR. Smad3 activation in MIF-treated cardiac fibroblasts was also detected by Western blot assay. Results Compared with the db/m control mice, the collagen content was significantly increased in the myocardium of diabetic db/db mice. MIF was up-regulated, but miR-29b was down-regulated in the diabetic myocardium. Quantitative real-time PCR and Western blot assay showed that MIF could inhibit fibrosis-associated Collal, Col3al and α-SMA expressions in mouse cardiac fibroblasts. Smad3 activation was inhibited, but miR-29b was up-regulated in MIF-treated cardiac fibroblasts. Enforced expression of miR-29b significantly suppressed Collal, Col3al, and oL-SMA mRNA and lprotein expressions in cardiac fibroblasts. Conclusions MIF possesses the anti-fibrosis activity through inhibiting Smad3 activation and through up-regulating miR-29b expression, and miR-29b can inhibit fibrosis-associated Collal, Col3al and α-SMA expressions in cardiac fibroblasts.