GPNMB regulates M2 polarization of microglia thereby alleviating nerve injury after cerebral ischemic stroke through PI3K/Akt pathway / 中国免疫学杂志

Objective:To investigate the mechanism by which glycoprotein non-transferable melanin B(GPNMB)regulates microglia M2 polarization to reduce nerve damage after cerebral ischemic stroke(CIS).Methods:SD rats were used for establishment of middle cerebral artery occlusion(MCAO)model.Neurons,astrocytes and microglia were cultured under oxygen and glucose depri-vation(OGD)conditions,and the expression of GPNMB in tissues and cells were measured by Western blot.Gpnmb wrapped with adeno-associated virus(AAV)or shRNA-Gpnmb were injected into rat brain tissues for overexpression or inhibition of GPNMB,modified neurological deficit score(mNSS),Rotarod fatigue test and tape removal test were used to evaluate rat nerve function,the proportion of cerebral infarction was determined by TTC staining,microglia M1/M2 polarization markers were detected by immunofluorescence and RT-PCR,and the expression of Phosphatidylinositol 3-kinase(PI3K)/Serine/threonine kinase(Akt)pathway was determined by Western blot.Microglia was cultured under OGD conditions in vitro,Gpnmb was overexpressed and PI3K expression were inhibited by LY294002,and M1/M2 polarization markers were measured.Results:Compared with normal rats or normal cultured cells,the expres-sion of GPNMB in MCAO model or OGD-intervened microglia was up-regulated(P<0.05);when Gpnmb was overexpressed in the brain tissue of MCAO rats,the mNSS score decreased,the Rotarod time of latency to fall lengthened,the contact time and removal time shortened in the tape removal test,the proportion of cerebral infarction decreased,the M1 polarization level of microglia decreased while the M2 polarization level increased,PI3K/Akt pathway activated,and these difference were statistically significant(P<0.05);inhibition of PI3K reversed the effect of overexpression of Gpnmb on promoting M2 polarization of microglia in vitro(P<0.05).Conclusion:GPNMB promotes M2 polarization of microglia by activating the PI3K/Akt pathway,thereby reducing nerve damage after CIS.

Application of Linear Regression Model of Gpnmb Gene in Rat Injury Time Estimation / 法医学杂志

OBJECTIVES@#To investigate the effects of injury time, postmortem interval (PMI) and postmortem storage temperature on mRNA expression of glycoprotein non-metastatic melanoma protein B (Gpnmb), and to establish a linear regression model between Gpnmb mRNA expression and injury time, to provide aimed at providing potential indexes for injury time estimation.@*METHODS@#Test group SD rats were anesthetized and subjected to blunt contusion and randomly divided into 0 h, 4 h, 8 h, 12 h, 16 h, 20 h and 24 h groups after injury, with 18 rats in each group. After cervical dislocation, 6 rats in each group were collected and stored at 0 ℃, 16 ℃ and 26 ℃, respectively. The muscle tissue samples of quadriceps femoris injury were collected at 0 h, 12 h and 24 h postmortem at the same temperature. The grouping method and treatment method of the rats in the validation group were the same as above. The expression of Gpnmb mRNA in rat skeletal muscle was detected by RT-qPCR. The Pearson correlation coefficient was used to evaluate the correlation between Gpnmb mRNA expression and injury time, PMI, and postmortem storage temperature. SPSS 25.0 software was used to construct a linear regression model, and the validation group data was used for the back-substitution test.@*RESULTS@#The expression of Gpnmb mRNA continued to increase with the prolongation of injury time, and the expression level was highly correlated with injury time (P<0.05), but had little correlation with PMI and postmortem storage temperature (P>0.05). The linear regression equation between injury time (y) and Gpnmb mRNA relative expression (x) was y=0.611 x+4.489. The back-substitution test proved that the prediction of the model was accurate.@*CONCLUSIONS@#The expression of Gpnmb mRNA is almost not affected by the PMI and postmortem storage temperature, but is mainly related to the time of injury. Therefore, a linear regression model can be established to infer the time of injury.

Long non-coding RNA MALAT1 regulates cell proliferation and apoptosis via miR-135b-5p/GPNMB axis in Parkinson's disease cell model

BACKGROUNDS: Parkinson's disease (PD) is a common age-related neurodegenerative disorder worldwide. This research aimed to investigate the effects and mechanism underlying long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in PD. METHODS: SK-N-SH and SK-N-BE cells were treated with MPP+ to establish the MPP+-stimulated cell model of PD, and MALAT1 expression was determined. Then, the effects of MALAT1 depletion on cell proliferation and apoptosis were determined in the MPP+-stimulated cell model of PD. Besides, the correlations between microRNA-135b-5p (miR-135b-5p) and MALAT1 or glycoprotein nonmetastatic melanoma protein B (GPNMB) in MPP+-stimulated cell model of PD were explored. RESULTS: MALAT1 was increasingly expressed and downregulation of MALAT1 promoted cell proliferation while inhibited apoptosis in MPP+-stimulated cells. Besides, miR-135b-5p was a target of MALAT1 and directly targeted to GPNMB. Further investigation indicated that suppression of MALAT1 regulated cell proliferation and apoptosis by miR-135b-5p/GPNMB axis. CONCLUSION: Our findings reveal that MALAT1/miR-135b-5p/GPNMB axis regulated cell proliferation and apoptosis in MPP+-stimulated cell model of PD, providing a potential biomarker and therapeutic target for PD.

Glycoprotein nonmetastatic melanoma protein B accelerates tumorigenesis of cervical cancer in vitro by regulating the Wnt/ß-catenin pathway

Cervical cancer is one of the most common cancers among women around the world. However, the underlying mechanism involved in cervical cancer progression is incompletely known. In the present study, we determined the role of glycoprotein nonmetastatic melanoma protein B (GPNMB) in tumorigenesis of cervical cancer. According to the GEO database, we found that GPNMB expression was significantly higher in cervical cancer than in normal cervix epithelium. A similar pattern was observed in GPNMB expression in cultured cervical cancer cells and normal cervical epithelial cells. Compared with the control, GPNMB knockdown significantly decreased the proliferation and migration capacity, but enhanced the apoptosis capacity of SiHa and HeLa cells. Additionally, the activity of MMP-2 and MMP-9 were aberrantly increased in SiHa and HeLa cells compared with normal cervical epithelial cells, whereas their activities were strongly inhibited by GPNMB siRNA. Furthermore, Wnt/β-catenin signaling was activated by GPNMB in SiHa and HeLa cells. Increased MMP-2/MMP-9 expression was suppressed by Dkk-1, inhibitor of Wnt/β-catenin signaling, while it was enhanced by stimulator BIO. The proliferation, migration, and apoptosis capacity of HeLa cells were found to be affected by Dkk-1 and BIO to different extents. In conclusion, we demonstrated that GPNMB contributed to the tumorigenesis of cervical cancer, at least in part, by regulating MMP-2/MMP-9 activity in tumor cells via activation of canonical Wnt/β-catenin signaling. This might be a potential therapeutic target for treating human cervical cancer.

Differences of Gpnmb expression in M1 and M2 bone marrow-derived macrophages in mouse / 中华微生物学和免疫学杂志

Objective To investigate the differences of glycoprotein non-metastatic melanoma b (Gpnmb) expression between M1 and M2 bone marrow-derived macrophages (BMMφs) in mouse.Meth-ods Primary BMMφs were cultured and then identified by immunofluorescence staining for F 4/80 and flow cytometry testing of CD11b.Interferon-γand lipopolysaccharide were used to induce differentiation of BMMφs towards M1 macrophages and interleukin-4 was adopted to induce differentiation of M 2 macropha-ges.Realtime PCR was performed to analyze mRNA expressions of tumor necrosis factor (TNF-α), induc-ible NO synthase (iNOS), macrophage mannose receptor (MMR), arginase-1 (Arg-1) and Gpnmb.Pro-teins of Gpnmb and MMR were detected by double immunofluorescence staining , Western blot and flow cy-tometry.Results (1) Immunofluorescence staining showed high expression of F 4/80 in BMMφs and flow cytometry results showed that CD11b was expressed in 92.7%±6.1% of BMMφs, suggesting that primary BMMφs were successfully cultured.(2) Compared with M0 BMMφs, mRNAs of TNF-αand iNOS were highly up-regulated in M1 BMMφs (both P<0.01), and mRNAs of MMR and Arg-1 were highly up-regula-ted in M2 BMMφs (both P<0.01), indicating that differentiation of BMMφs towards M1 and M2 BMMφs were successfully induced .(3) Expressions of Gpnmb mRNA and Gpnmb protein were predominantly up-regulated in M2 BMMφs in comparison with those in M0 and M1 BMMφs (both P<0.01).Gpnmb and MMR were co-expressed in M2 BMMφs and 83.2%±9.7% of MMR positive BMMφs expressed Gpnmb. Conclusion Gpnmb expression is significantly increased in M 2 macrophages than that in M 1 macrophages in vitro, indicating that Gpnmb which takes part in the differentiation of macrophages might be used as a marker for identification of M 1 and M2 macrophages .

Effect of glycoprotein (transmembrane) nonmetastatic melanoma protein B on the proliferation and migration of as well as melanogenesis in melanoma cells / 中华皮肤科杂志

Objective To estimate the effect of glycoprotein (transmembrane) nonmetastatic melanoma protein B (GPNMB) on the proliferation and migration of as well as melanogenesis in melanoma cells.Methods The expression of GPNMB was detected by immunofluorescence assay in two melanoma cell lines M14 and G-361,as well as in primary human melanocytes.Then,the three kinds of cells each were classified into three groups:experimental group treated with small interfering RNA targeting GPNMB (GPNMB-siRNA),negative control group treated with the negative control siRNA,blank control group remaining untreated.Methyl thiazolyl tetrazolium (MTT) assay,transwell invasion assay and spectrophotometry were performed to evaluate cell proliferation activity,invasion potential and melanin levels,respectively.Statistical analysis was done using Student's t test.Results GPNMB was expressed in both melanoma cells and melanocytes.The transfection with GPNMB-siRNA down-regulated the mRNA and protein expressions of GPNMB in,and markedly suppressed the proliferation and migration of,melanoma cells.In detail,the proliferative activity (expressed as the absorbence value at 570 nm) of M14 and G361 cells was reduced by 35％ and 40％ respectively,the migration activity of M14 and G361 cells by 49％ and 51％ respectively,and the melanin levels in melanocytes,M14 cells and G361 cells by 73％,82％ and 69％ respectively,in the experiment group compared with those in the blank control group.Conclusions The siRNA-mediated silencing of GPNMB could effectively inhibit the proliferation of,invasion of and melanogenesis in melanoma cells,which suggests that GPNMB plays critical roles in the initiation and progression of melanoma.

Expression of Gpnmb in NK Cell Development from Hematopoietic Stem Cells

BACKGROUND: Molecular mechanisms of natural killer (NK) cell development from hematopoietic stem cells (HSCs) have not been clearly elucidated, although the roles of some genes in NK cell development have been reported previously. Thus, searching for molecules and genes related NK cell developmental stage is important to understand the molecular events of NK cell development. METHODS: From our previous SAGE data-base, Gpnmb (Glycoprotein non-metastatic melanoma protein B) was selected for further analysis. We confirmed the level of mRNA and protein of Gpnmb through RT-PCR, quantitative PCR, and FACS analysis. Then we performed cell-based ELISA and FACS analysis, to know whether there are some molecules which can bind to Gpnmb. Using neutralizing antibody, we blocked the interaction between NK cells and OP9 cells, and checked IFN-gamma production by ELISA kit. RESULTS: Gpnmb expression was elevated during in vitro developmental stage and bound to OP9 cells, but not to NK precursor cells. In addition, we confirmed that the levels of Gpnmb were increased at NK precursor stage in vivo. We confirmed syndecan4 as a candidate of Gpnmb's binding molecule. When the interaction between NK cells and OP9 cells were inhibited in vitro, IFN-gamma production from NK cells were reduced. CONCLUSION: Based on these observations, it is concluded that Gpnmb has a potential role in NK cell development from HSCs.