AIM： To examine the role of Fibrinogen-like protein 2 （fgl2）/fibroleukin in tumor development. Fgl2 has been reported to play a vital role in the pathogenesis in MHV-3 （mouse hepatitis virus） induced fulminant an...AIM： To examine the role of Fibrinogen-like protein 2 （fgl2）/fibroleukin in tumor development. Fgl2 has been reported to play a vital role in the pathogenesis in MHV-3 （mouse hepatitis virus） induced fulminant and severe hepatitis, spontaneous abortion, allo- and xenograft rejection by mediating ＂immune coagulation＂.METHODS： Tumor tissues from 133 patients with six types of distinct cancers and the animal tumor tissues from human hepatocellular carcinoma （HCC） model on nude mice （established from high metastasis HCC cell line MHCC97LM6） were obtained. RESULTS： HfgI2 was detected in tumor tissues from 127 out of 133 patients as well as tumor tissues collected from human HCC nude mice. Hfgl2 was highly expressed both in cancer cells and interstitial inflammatory cells including macrophages, NK cells, and CD8^＋ T lymphocytes and vascular endothelial cells. HfgI2 mRNA was localized in cells that expressed hfgI2 protein. Fibrin （nogen） colocalization with hfgl2 expression was determined by dual immunohistochemical staining. In vitro, IL-2 and IFN-γ, increased hfgl2 mRNA by 10-100 folds and protein expression in both THP-1 and HUVEC cell lines. One-stage clotting assays demonstrated that THP-1 and HUVEC cells expressing hfgl2 had increased procoagulant activity following cytokines stimulation. CONCLUSION： The hfgI2 contributes to the hypercoagulability in cancer and may induce tumor angiogenesis and metastasis via cytokine induction.展开更多
AIM: To examine fibrinogen-like protein 2 (fgl2) expression during taurocholate-induced acute pancreatitis progression in rats and its correlation with pancreatic injury severity. METHODS: Forty-eight male Sprague-Daw...AIM: To examine fibrinogen-like protein 2 (fgl2) expression during taurocholate-induced acute pancreatitis progression in rats and its correlation with pancreatic injury severity. METHODS: Forty-eight male Sprague-Dawley rats were randomly divided into the severe acute pancreatitis (SAP) group (n = 24) and the sham operation (SO) group (n = 24). Sodium taurocholate (4% at doses of 1 mL/kg body weight) was retrogradely injected into the biliopancreatic ducts of the rats to induce SAP. Pancreatic tissues were prepared immediately after sacrifice. At the time of sacrifice, blood was obtained for determination of serum amylase activity and isolation of peripheral blood mononuclear cells (PBMCs). Pancreatic tissue specimens were obtained for routine light microscopy including hematoxylin and eosin staining, and the severity of pancreatic injury was evaluated 1, 4 and 8 h after induction. Expression of fgl2 mRNA was measured in the pancreas and PBMCs using reverse transcription polymerase chain reaction. Expression of fgl2 protein was evaluated in pancreatic tissues using Western blotting and immunohistochemical staining. Masson staining was also performed to observe microthrombosis. RESULTS: At each time point, levels of fgl2 mRNAs in pancreatic tissues and PBMCs were higher (P < 0.05) in the SAP group than in the SO group. For pancreatic tissue in SAP vs SO, the levels were: after 1 h, 3.911 ± 1.277 vs 1.000 ± 0.673; after 4 h, 9.850 ± 3.095 vs 1.136 ± 0.609; and after 8 h, 12.870 ± 3.046 vs 1.177 ± 0.458. For PBMCs in SAP vs SO, the levels were: after 1 h, 2.678 ± 1.509 vs 1.000 ± 0.965; after 4 h, 6.922 ± 1.984 vs 1.051 ± 0.781; and after 8 h, 13.533 ± 6.575 vs 1.306 ± 1.179. Levels of fgl2 protein expression as determined by Western blotting and immunohistochemical staining were markedly up-regulated (P < 0.001) in the SAP group compared with those in the SO group. For Western blotting in SAP vs SO, the results were: after 1 h, 2.183 ± 0.115 vs 1.110 ± 0.158; after 4 h, 2.697 ± 0.090 vs 0.947 ± 0.361; and after 8 h, 3.258 ± 0.094 vs 1.208 ± 0.082. For immunohistochemical staining in SAP vs SO, the results were: after 1 h, 1.793 ± 0.463 vs 0.808 ± 0.252; after 4 h, 4.535 ± 0.550 vs 0.871 ± 0.318; and after 8 h, 6.071 ± 0.941 vs 1.020 ± 0.406. Moreover, we observed a positive correlation in the pancreas (r = 0.852, P < 0.001) and PBMCs (r = 0.735, P < 0.001) between fgl2 expression and the severity of pancreatic injury. Masson staining showed that microthrombosis (%) in rats with SAP was increased (P < 0.001) compared with that in the SO group and it was closely correlated with fgl2 expression in the pancreas (r = 0.842, P < 0.001). For Masson staining in SAP vs SO, the results were: after 1 h, 26.880 ± 9.031 vs 8.630 ± 3.739; after 4 h, 53.750 ± 19.039 vs 8.500 ± 4.472; and after 8 h, 80.250 ± 12.915 vs 10.630 ± 7.003.CONCLUSION: Microthrombosis due to fgl2 overexpression contributes to pancreatic impairment in rats with SAP, and fgl2 level may serve as a biomarker during early stages of disease.展开更多
Fibrinogen-like protein 2 （fgl2）, a novel prothrombinase, is involved in microthrombosis. We examined fgl2 expression in the glomerular and tubulointerstitial capillaries and its correlation with microthromsis in ra...Fibrinogen-like protein 2 （fgl2）, a novel prothrombinase, is involved in microthrombosis. We examined fgl2 expression in the glomerular and tubulointerstitial capillaries and its correlation with microthromsis in rats with streptozocin-induced type 2 diabetic nephropathy. Our RT-PCR and immunoblotting analysis showed that fgl2 mRNA and protein levels were increased in microvascular endothelial cells of the glomeruli and renal interstitia at week 19 and became significantly elevated with the development of diabetic nephropathy （P 〈 0.01）. Fgl2 was not or only weakly expressed in the renal tissues of normal rats. Furthermore, a direct significant correlation （r = 0.543, P 〈 0.01） was found between fgl2 expression and microthrombotic capillaries in the renal tissues. Enzyme linked immunosorbent assays （ELISA） additionally showed that circulating TNF-α levels in rats with type 2 diabetes were significantly elevated and closely correlated with fgl2 expression （r = 0.871, P 〈 0.01）. Our results suggest that fgl2 may activate renal microthrombosis, thus contributing to glomerular hypertension and renal ischemia.展开更多
BACKGROUND Heterogeneous macrophages play an important role in multiple liver diseases,including viral fulminant hepatitis(VFH).Fibrinogen-like protein 2(FGL2)is expressed on macrophages and regulates VFH pathogenesis...BACKGROUND Heterogeneous macrophages play an important role in multiple liver diseases,including viral fulminant hepatitis(VFH).Fibrinogen-like protein 2(FGL2)is expressed on macrophages and regulates VFH pathogenesis;however,the underlying mechanism remains unclear.AIM To explore how FGL2 regulates macrophage function and subsequent liver injury during VFH.METHODS Murine hepatitis virus strain 3(MHV-3)was used to induce VFH in FGL2-deficient(Fgl2-/-)and wild-type(WT)mice.The dynamic constitution of hepatic macrophages was examined.Adoptive transfer of Fgl2-/-or WT bone marrowderived macrophages(BMDMs)into WT recipients with macrophages depleted prior to infection was carried out and the consequent degree of liver damage was compared.The signaling cascades that may be regulated by FGL2 were detected in macrophages.RESULTS Following MHV-3 infection,hepatic macrophages were largely replenished by proinflammatory monocyte-derived macrophages(MoMFs),which expressed high levels of FGL2.In Fgl2-/-mice,the number of infiltrating inflammatory MoMFs was reduced compared with that in WT mice after viral infection.Macrophage depletion ameliorated liver damage in WT mice and further alleviated liver damage in Fgl2-/-mice.Adoptive transfer of Fgl2-/-BMDMs into macrophage-removed recipients significantly reduced the degree of liver damage.Inhibition of monocyte infiltration also significantly ameliorated liver damage.Functionally,Fgl2 deletion impaired macrophage phagocytosis and the antigen presentation potential and attenuated the proinflammatory phenotype.At the molecular level,FGL2 deficiency impaired IRF3,IRF7,and p38 phosphorylation,along with NF-κB activation in BMDMs in response to viral infection.CONCLUSION Infiltrated MoMFs represent a major source of hepatic inflammation during VFH progression,and FGL2 expression on MoMFs maintains the proinflammatory phenotype via p38-dependent positive feedback,contributing to VFH pathogenesis.展开更多
BACKGROUND Crohn’s disease(CD)is an incurable intestinal disorder with unclear etiology and pathogenesis.Currently,there is a lack of specific biomarkers and drug targets for CD in clinical practice.It is essential t...BACKGROUND Crohn’s disease(CD)is an incurable intestinal disorder with unclear etiology and pathogenesis.Currently,there is a lack of specific biomarkers and drug targets for CD in clinical practice.It is essential to identify the precise pathophysiological mechanism of CD and investigate new therapeutic targets.AIM To explore a new biomarker and therapeutic target for CD and verify its role in the CD pathological mechanism.METHODS Proteomics was performed to quantify the protein profile in the plasma of 20 CD patients and 20 matched healthy controls.Hub genes among the selected differentially expressed proteins(DEPs)were detected via the MCODE plugin in Cytoscape software.The expression level of one hub gene with an immunoregulatory role that interested us was verified in the inflamed intestinal tissues of 20 CD patients by immunohistochemical analysis.After that,the effects of the selected hub gene on the intestinal inflammation of CD were identified in a CD cell model by examining the levels of proinflammatory cytokines by enzymelinked immunosorbent assays and the expression of the NF-κB signalling pathway by quantitative real-time PCR analysis and Western blot assays.RESULTS Thirty-five DEPs were selected from 393 credible proteins identified by proteomic analysis.Among the DEPs,fibrinogen-like protein 1(FGL1),which attracted our attention due to its function in the regulation of the immune response,had 1.722-fold higher expression in the plasma of CD patients and was identified as a hub gene by MCODE.Furthermore,the expression of FGL1 in the intestinal mucosal and epithelial tissues of CD patients was also upregulated(P<0.05).In vitro,the mRNA levels of FGL1 and NF-κB;the protein expression levels of FGL1,IKKα,IKKβ,p-IKKα/β,p-IκBα,and p-p65;and the concentrations of the proinflammatory cytokines IL-1β,IL-6,IL-17,and TNF-αwere increased(P<0.05)after stimulation with lipopolysaccharide,which were reversed by knockdown of FGL1 with siRNA transfection(P<0.05).Conversely,FGL1 overexpression enhanced the abovementioned results(P<0.05).CONCLUSION FGL1 can induce intestinal inflammation by activating the canonical NF-κB signalling pathway,and it may be considered a potential biomarker and therapeutic target for CD.展开更多
AIMTo determine the effect of overexpression of fibrinogen-like protein 2 (FGL2) on regulatory T cell (Treg) and effector T (Teff) cell function on T cell-induced colitis in Rag1<sup>-/-</sup> mice.METHODS...AIMTo determine the effect of overexpression of fibrinogen-like protein 2 (FGL2) on regulatory T cell (Treg) and effector T (Teff) cell function on T cell-induced colitis in Rag1<sup>-/-</sup> mice.METHODSTreg and Teff cells from fgl2<sup>-/-</sup>, fgl2<sup>+/+</sup>, and fgl2<sup>Tg</sup> mice were purified by FACS. They were studied in vitro for immunosuppressive activity and cell proliferation and in vivo for their effects on the development and prevention of T cell-induced colitis in Rag1<sup>-/-</sup> mice.RESULTSIn vitro, fgl2<sup>Tg</sup> Treg had enhanced immunosuppressive activity, and fgl2<sup>Tg</sup> Teff had reduced proliferation to alloantigen stimulation. Transfer of Teff from C57Bl/6J mice (fgl2<sup>+/+</sup>) into Rag1<sup>-/-</sup> mice produced both clinical and histologic colitis with dense infiltrates of CD3<sup>+</sup> T cells, crypt abscesses and loss of goblet cells. Fgl2<sup>Tg</sup> Treg prevented the development of T cell-induced colitis, whereas fgl2<sup>+/+</sup> and fgl2<sup>-/-</sup> Treg were only partially protective. In mice that received fgl2<sup>Tg</sup> Treg, the ratio of Foxp3<sup>+</sup> to CD3<sup>+</sup> cells was increased both in the colon and in mesenteric lymph nodes, and Teff cell proliferation as determined by staining with Ki67 was reduced. Teff cells from fgl2<sup>Tg</sup> mice did not produce colitis.CONCLUSIONHere we show that fgl2<sup>Tg</sup> Teff are hypoproliferative and do not induce colitis. We further demonstrate that fgl2<sup>Tg</sup> Treg prevent colitis in contrast to fgl2<sup>+/+</sup> Treg, which were only partially protective. These studies collectively provide a rationale for exploring the use of FGL2 or Treg expressing high levels of FGL2 in the treatment of inflammatory bowel disease.展开更多
Fibrinogen-like 2(FGL2) encompasses a transmembrane(m FGL2) and a soluble(s FGL2) form with differential tertiary structure and biological activities. Typically, m FGL2 functions as prothrombinase that is capable of i...Fibrinogen-like 2(FGL2) encompasses a transmembrane(m FGL2) and a soluble(s FGL2) form with differential tertiary structure and biological activities. Typically, m FGL2 functions as prothrombinase that is capable of initiating coagulation in tissue without activation of the blood clotting cascade, whereas s FGL2 largely acts as an immunosuppressor that can repress proliferation of alloreactive T lymphocytes and maturation of bone marrow dendritic cells. Protein sequences of FGL2 exhibit evolutionary conservation across wide variety of species, especially at the carboxyl terminus that contains fibrinogen related domain(FRED). The FRED of FGL2 confers specificity and complexity in the action of FGL2, including receptor recognition, calcium affiliation, and substrate binding. Constitutive expression of FGL2 during embryogenesis and in mature tissues suggests FGL2 might be physiologically important. However, excessive induction of FGL2 under certain medical conditions(e.g. pathogen invasion) could trigger complement activation, inflammatory response,cellular apoptosis, and immune dysfunctions. On the other hand, complete absence of FGL2 is also detrimental as lack of FGL2 can cause autoimmune glomerulonephritis and acute cellular rejection of xenografts. All these roles involve m FGL2, s FGL2, or their combination. Although it is not clear how m FGL2 is cleaved off its host cells and secreted into the blood, circulating s FGL2 has been found correlated with disease severity and viral loading among patients with human hepatitis B virus or hepatitis C virus infection. Further studies are warranted to understand how FGL2 expression is regulated under physiological and pathological conditions. Even more interesting is to determine whether m FGL2 can fulfill an immunoregulatory role through its FRED at carboxyl end of the molecule and, and vice versa, whether s FGL2 is procoagulant upon binding to a target cell. Knowledge in this area should shed light on development of s FGL2 as an alternative immunosuppressive agent for organ transplantation or as a biomarker for predicting disease progression, monitoring therapeutic effects, and targeting FGL2 for repression in ameliorating fulminant viral hepatitis.展开更多
Partial hepatectomy is a first-line treatment for hepatocellular carcinoma.Within 2 weeks following partial hepatectomy,specific molecular pathways are activated to promote liver regeneration.Nevertheless,residual mic...Partial hepatectomy is a first-line treatment for hepatocellular carcinoma.Within 2 weeks following partial hepatectomy,specific molecular pathways are activated to promote liver regeneration.Nevertheless,residual microtumors may also exploit these pathways to reappear and metastasize.Therapeutically targeting molecules that are differentially regulated between normal cells and malignancies,such as fibrinogen-like protein 1(FGL1),appears to be an effective approach.The potential functions of FGL1 in both regenerative and malignant cells are discussed within the ambit of this review.While FGL1 is normally elevated in regenerative hepatocytes,it is normally downregulated in malignant cells.Hepatectomy does indeed upregulate FGL1 by increasing the release of transcription factors that promote FGL1,including HNF-1α and STAT3,and inflammatory effectors,such as TGF-β and IL6.This,in turn,stimulates certain proliferative pathways,including EGFR/Src/ERK.Hepatectomy alters the phase transition of highly differentiated hepatocytes from G0 to G1,thereby transforming susceptible cells into cancerous ones.Activation of the PI3K/Akt/mTOR pathway by FGL1 allele loss on chromosome 8,a tumor suppressor area,may also cause hepatocellular carcinoma.Interestingly,FGL1 is specifically expressed in the liver via HNF-1α histone acetylase activity,which triggers lipid metabolic reprogramming in malignancies.FGL1 might also be involved in other carcinogenesis processes such as hypoxia,epithelial-mesenchymal transition,immunosuppression,and sorafenib-mediated drug resistance.This study highlights a research gap in these disciplines and the necessity for additional research on FGL1 function in the described processes.展开更多
基金The Natural Science Foundation of China,NSFC (30672380,30571643)National Key Basic Research Program of China (2007CB512900,2005CB522901,2005CB522507)11th Five-Year Plan Key Project (2006BAI05A07)
文摘AIM： To examine the role of Fibrinogen-like protein 2 （fgl2）/fibroleukin in tumor development. Fgl2 has been reported to play a vital role in the pathogenesis in MHV-3 （mouse hepatitis virus） induced fulminant and severe hepatitis, spontaneous abortion, allo- and xenograft rejection by mediating ＂immune coagulation＂.METHODS： Tumor tissues from 133 patients with six types of distinct cancers and the animal tumor tissues from human hepatocellular carcinoma （HCC） model on nude mice （established from high metastasis HCC cell line MHCC97LM6） were obtained. RESULTS： HfgI2 was detected in tumor tissues from 127 out of 133 patients as well as tumor tissues collected from human HCC nude mice. Hfgl2 was highly expressed both in cancer cells and interstitial inflammatory cells including macrophages, NK cells, and CD8^＋ T lymphocytes and vascular endothelial cells. HfgI2 mRNA was localized in cells that expressed hfgI2 protein. Fibrin （nogen） colocalization with hfgl2 expression was determined by dual immunohistochemical staining. In vitro, IL-2 and IFN-γ, increased hfgl2 mRNA by 10-100 folds and protein expression in both THP-1 and HUVEC cell lines. One-stage clotting assays demonstrated that THP-1 and HUVEC cells expressing hfgl2 had increased procoagulant activity following cytokines stimulation. CONCLUSION： The hfgI2 contributes to the hypercoagulability in cancer and may induce tumor angiogenesis and metastasis via cytokine induction.
文摘AIM: To examine fibrinogen-like protein 2 (fgl2) expression during taurocholate-induced acute pancreatitis progression in rats and its correlation with pancreatic injury severity. METHODS: Forty-eight male Sprague-Dawley rats were randomly divided into the severe acute pancreatitis (SAP) group (n = 24) and the sham operation (SO) group (n = 24). Sodium taurocholate (4% at doses of 1 mL/kg body weight) was retrogradely injected into the biliopancreatic ducts of the rats to induce SAP. Pancreatic tissues were prepared immediately after sacrifice. At the time of sacrifice, blood was obtained for determination of serum amylase activity and isolation of peripheral blood mononuclear cells (PBMCs). Pancreatic tissue specimens were obtained for routine light microscopy including hematoxylin and eosin staining, and the severity of pancreatic injury was evaluated 1, 4 and 8 h after induction. Expression of fgl2 mRNA was measured in the pancreas and PBMCs using reverse transcription polymerase chain reaction. Expression of fgl2 protein was evaluated in pancreatic tissues using Western blotting and immunohistochemical staining. Masson staining was also performed to observe microthrombosis. RESULTS: At each time point, levels of fgl2 mRNAs in pancreatic tissues and PBMCs were higher (P < 0.05) in the SAP group than in the SO group. For pancreatic tissue in SAP vs SO, the levels were: after 1 h, 3.911 ± 1.277 vs 1.000 ± 0.673; after 4 h, 9.850 ± 3.095 vs 1.136 ± 0.609; and after 8 h, 12.870 ± 3.046 vs 1.177 ± 0.458. For PBMCs in SAP vs SO, the levels were: after 1 h, 2.678 ± 1.509 vs 1.000 ± 0.965; after 4 h, 6.922 ± 1.984 vs 1.051 ± 0.781; and after 8 h, 13.533 ± 6.575 vs 1.306 ± 1.179. Levels of fgl2 protein expression as determined by Western blotting and immunohistochemical staining were markedly up-regulated (P < 0.001) in the SAP group compared with those in the SO group. For Western blotting in SAP vs SO, the results were: after 1 h, 2.183 ± 0.115 vs 1.110 ± 0.158; after 4 h, 2.697 ± 0.090 vs 0.947 ± 0.361; and after 8 h, 3.258 ± 0.094 vs 1.208 ± 0.082. For immunohistochemical staining in SAP vs SO, the results were: after 1 h, 1.793 ± 0.463 vs 0.808 ± 0.252; after 4 h, 4.535 ± 0.550 vs 0.871 ± 0.318; and after 8 h, 6.071 ± 0.941 vs 1.020 ± 0.406. Moreover, we observed a positive correlation in the pancreas (r = 0.852, P < 0.001) and PBMCs (r = 0.735, P < 0.001) between fgl2 expression and the severity of pancreatic injury. Masson staining showed that microthrombosis (%) in rats with SAP was increased (P < 0.001) compared with that in the SO group and it was closely correlated with fgl2 expression in the pancreas (r = 0.842, P < 0.001). For Masson staining in SAP vs SO, the results were: after 1 h, 26.880 ± 9.031 vs 8.630 ± 3.739; after 4 h, 53.750 ± 19.039 vs 8.500 ± 4.472; and after 8 h, 80.250 ± 12.915 vs 10.630 ± 7.003.CONCLUSION: Microthrombosis due to fgl2 overexpression contributes to pancreatic impairment in rats with SAP, and fgl2 level may serve as a biomarker during early stages of disease.
基金supported by CGICC Medical Science Research Supporting Program (No.08010022)National Program on Key BasicResearch Project of China (No. 2007CB512000,Sub-Project No.2007CB512005)
文摘Fibrinogen-like protein 2 （fgl2）, a novel prothrombinase, is involved in microthrombosis. We examined fgl2 expression in the glomerular and tubulointerstitial capillaries and its correlation with microthromsis in rats with streptozocin-induced type 2 diabetic nephropathy. Our RT-PCR and immunoblotting analysis showed that fgl2 mRNA and protein levels were increased in microvascular endothelial cells of the glomeruli and renal interstitia at week 19 and became significantly elevated with the development of diabetic nephropathy （P 〈 0.01）. Fgl2 was not or only weakly expressed in the renal tissues of normal rats. Furthermore, a direct significant correlation （r = 0.543, P 〈 0.01） was found between fgl2 expression and microthrombotic capillaries in the renal tissues. Enzyme linked immunosorbent assays （ELISA） additionally showed that circulating TNF-α levels in rats with type 2 diabetes were significantly elevated and closely correlated with fgl2 expression （r = 0.871, P 〈 0.01）. Our results suggest that fgl2 may activate renal microthrombosis, thus contributing to glomerular hypertension and renal ischemia.
基金Supported by the National Science and Technology Major Project,No.2017ZX10202201and the National Natural Science Foundation of China,No.NSFC 81700529。
文摘BACKGROUND Heterogeneous macrophages play an important role in multiple liver diseases,including viral fulminant hepatitis(VFH).Fibrinogen-like protein 2(FGL2)is expressed on macrophages and regulates VFH pathogenesis;however,the underlying mechanism remains unclear.AIM To explore how FGL2 regulates macrophage function and subsequent liver injury during VFH.METHODS Murine hepatitis virus strain 3(MHV-3)was used to induce VFH in FGL2-deficient(Fgl2-/-)and wild-type(WT)mice.The dynamic constitution of hepatic macrophages was examined.Adoptive transfer of Fgl2-/-or WT bone marrowderived macrophages(BMDMs)into WT recipients with macrophages depleted prior to infection was carried out and the consequent degree of liver damage was compared.The signaling cascades that may be regulated by FGL2 were detected in macrophages.RESULTS Following MHV-3 infection,hepatic macrophages were largely replenished by proinflammatory monocyte-derived macrophages(MoMFs),which expressed high levels of FGL2.In Fgl2-/-mice,the number of infiltrating inflammatory MoMFs was reduced compared with that in WT mice after viral infection.Macrophage depletion ameliorated liver damage in WT mice and further alleviated liver damage in Fgl2-/-mice.Adoptive transfer of Fgl2-/-BMDMs into macrophage-removed recipients significantly reduced the degree of liver damage.Inhibition of monocyte infiltration also significantly ameliorated liver damage.Functionally,Fgl2 deletion impaired macrophage phagocytosis and the antigen presentation potential and attenuated the proinflammatory phenotype.At the molecular level,FGL2 deficiency impaired IRF3,IRF7,and p38 phosphorylation,along with NF-κB activation in BMDMs in response to viral infection.CONCLUSION Infiltrated MoMFs represent a major source of hepatic inflammation during VFH progression,and FGL2 expression on MoMFs maintains the proinflammatory phenotype via p38-dependent positive feedback,contributing to VFH pathogenesis.
基金Supported by National Natural Science Foundation of China,No.82074431The Open Projects of the Discipline of Chinese Medicine of Nanjing University of Chinese Medicine Supported by the Subject of Academic Priority Discipline of Jiangsu Higher Education Institutions,No.ZYX03KF034Suzhou Municipal Science and Technology Bureau,No.SYSD2020253 and No.SS202085.
文摘BACKGROUND Crohn’s disease(CD)is an incurable intestinal disorder with unclear etiology and pathogenesis.Currently,there is a lack of specific biomarkers and drug targets for CD in clinical practice.It is essential to identify the precise pathophysiological mechanism of CD and investigate new therapeutic targets.AIM To explore a new biomarker and therapeutic target for CD and verify its role in the CD pathological mechanism.METHODS Proteomics was performed to quantify the protein profile in the plasma of 20 CD patients and 20 matched healthy controls.Hub genes among the selected differentially expressed proteins(DEPs)were detected via the MCODE plugin in Cytoscape software.The expression level of one hub gene with an immunoregulatory role that interested us was verified in the inflamed intestinal tissues of 20 CD patients by immunohistochemical analysis.After that,the effects of the selected hub gene on the intestinal inflammation of CD were identified in a CD cell model by examining the levels of proinflammatory cytokines by enzymelinked immunosorbent assays and the expression of the NF-κB signalling pathway by quantitative real-time PCR analysis and Western blot assays.RESULTS Thirty-five DEPs were selected from 393 credible proteins identified by proteomic analysis.Among the DEPs,fibrinogen-like protein 1(FGL1),which attracted our attention due to its function in the regulation of the immune response,had 1.722-fold higher expression in the plasma of CD patients and was identified as a hub gene by MCODE.Furthermore,the expression of FGL1 in the intestinal mucosal and epithelial tissues of CD patients was also upregulated(P<0.05).In vitro,the mRNA levels of FGL1 and NF-κB;the protein expression levels of FGL1,IKKα,IKKβ,p-IKKα/β,p-IκBα,and p-p65;and the concentrations of the proinflammatory cytokines IL-1β,IL-6,IL-17,and TNF-αwere increased(P<0.05)after stimulation with lipopolysaccharide,which were reversed by knockdown of FGL1 with siRNA transfection(P<0.05).Conversely,FGL1 overexpression enhanced the abovementioned results(P<0.05).CONCLUSION FGL1 can induce intestinal inflammation by activating the canonical NF-κB signalling pathway,and it may be considered a potential biomarker and therapeutic target for CD.
基金Supported by the Heart and Stroke Foundation of Canada,No.G-13-0002851the Canadian Institutes of Health Research Training Program in Regenerative Medicine to Bartczak A and Chruscinski Athe Ontario Graduate Scholarship in Science and Technology to Bartczak A
文摘AIMTo determine the effect of overexpression of fibrinogen-like protein 2 (FGL2) on regulatory T cell (Treg) and effector T (Teff) cell function on T cell-induced colitis in Rag1<sup>-/-</sup> mice.METHODSTreg and Teff cells from fgl2<sup>-/-</sup>, fgl2<sup>+/+</sup>, and fgl2<sup>Tg</sup> mice were purified by FACS. They were studied in vitro for immunosuppressive activity and cell proliferation and in vivo for their effects on the development and prevention of T cell-induced colitis in Rag1<sup>-/-</sup> mice.RESULTSIn vitro, fgl2<sup>Tg</sup> Treg had enhanced immunosuppressive activity, and fgl2<sup>Tg</sup> Teff had reduced proliferation to alloantigen stimulation. Transfer of Teff from C57Bl/6J mice (fgl2<sup>+/+</sup>) into Rag1<sup>-/-</sup> mice produced both clinical and histologic colitis with dense infiltrates of CD3<sup>+</sup> T cells, crypt abscesses and loss of goblet cells. Fgl2<sup>Tg</sup> Treg prevented the development of T cell-induced colitis, whereas fgl2<sup>+/+</sup> and fgl2<sup>-/-</sup> Treg were only partially protective. In mice that received fgl2<sup>Tg</sup> Treg, the ratio of Foxp3<sup>+</sup> to CD3<sup>+</sup> cells was increased both in the colon and in mesenteric lymph nodes, and Teff cell proliferation as determined by staining with Ki67 was reduced. Teff cells from fgl2<sup>Tg</sup> mice did not produce colitis.CONCLUSIONHere we show that fgl2<sup>Tg</sup> Teff are hypoproliferative and do not induce colitis. We further demonstrate that fgl2<sup>Tg</sup> Treg prevent colitis in contrast to fgl2<sup>+/+</sup> Treg, which were only partially protective. These studies collectively provide a rationale for exploring the use of FGL2 or Treg expressing high levels of FGL2 in the treatment of inflammatory bowel disease.
文摘Fibrinogen-like 2(FGL2) encompasses a transmembrane(m FGL2) and a soluble(s FGL2) form with differential tertiary structure and biological activities. Typically, m FGL2 functions as prothrombinase that is capable of initiating coagulation in tissue without activation of the blood clotting cascade, whereas s FGL2 largely acts as an immunosuppressor that can repress proliferation of alloreactive T lymphocytes and maturation of bone marrow dendritic cells. Protein sequences of FGL2 exhibit evolutionary conservation across wide variety of species, especially at the carboxyl terminus that contains fibrinogen related domain(FRED). The FRED of FGL2 confers specificity and complexity in the action of FGL2, including receptor recognition, calcium affiliation, and substrate binding. Constitutive expression of FGL2 during embryogenesis and in mature tissues suggests FGL2 might be physiologically important. However, excessive induction of FGL2 under certain medical conditions(e.g. pathogen invasion) could trigger complement activation, inflammatory response,cellular apoptosis, and immune dysfunctions. On the other hand, complete absence of FGL2 is also detrimental as lack of FGL2 can cause autoimmune glomerulonephritis and acute cellular rejection of xenografts. All these roles involve m FGL2, s FGL2, or their combination. Although it is not clear how m FGL2 is cleaved off its host cells and secreted into the blood, circulating s FGL2 has been found correlated with disease severity and viral loading among patients with human hepatitis B virus or hepatitis C virus infection. Further studies are warranted to understand how FGL2 expression is regulated under physiological and pathological conditions. Even more interesting is to determine whether m FGL2 can fulfill an immunoregulatory role through its FRED at carboxyl end of the molecule and, and vice versa, whether s FGL2 is procoagulant upon binding to a target cell. Knowledge in this area should shed light on development of s FGL2 as an alternative immunosuppressive agent for organ transplantation or as a biomarker for predicting disease progression, monitoring therapeutic effects, and targeting FGL2 for repression in ameliorating fulminant viral hepatitis.
基金supported by the Doctoral Research Fund of Hubei University of Science and Technology,with project number Q201810.
文摘Partial hepatectomy is a first-line treatment for hepatocellular carcinoma.Within 2 weeks following partial hepatectomy,specific molecular pathways are activated to promote liver regeneration.Nevertheless,residual microtumors may also exploit these pathways to reappear and metastasize.Therapeutically targeting molecules that are differentially regulated between normal cells and malignancies,such as fibrinogen-like protein 1(FGL1),appears to be an effective approach.The potential functions of FGL1 in both regenerative and malignant cells are discussed within the ambit of this review.While FGL1 is normally elevated in regenerative hepatocytes,it is normally downregulated in malignant cells.Hepatectomy does indeed upregulate FGL1 by increasing the release of transcription factors that promote FGL1,including HNF-1α and STAT3,and inflammatory effectors,such as TGF-β and IL6.This,in turn,stimulates certain proliferative pathways,including EGFR/Src/ERK.Hepatectomy alters the phase transition of highly differentiated hepatocytes from G0 to G1,thereby transforming susceptible cells into cancerous ones.Activation of the PI3K/Akt/mTOR pathway by FGL1 allele loss on chromosome 8,a tumor suppressor area,may also cause hepatocellular carcinoma.Interestingly,FGL1 is specifically expressed in the liver via HNF-1α histone acetylase activity,which triggers lipid metabolic reprogramming in malignancies.FGL1 might also be involved in other carcinogenesis processes such as hypoxia,epithelial-mesenchymal transition,immunosuppression,and sorafenib-mediated drug resistance.This study highlights a research gap in these disciplines and the necessity for additional research on FGL1 function in the described processes.
