C3 glomerulopathy is a disease including both dense deposit disease and C3 glomerulonephritis has an estimated prevalence of 2 to 3 per million. Originally, these pathologies were defined as glomerular pathology chara...C3 glomerulopathy is a disease including both dense deposit disease and C3 glomerulonephritis has an estimated prevalence of 2 to 3 per million. Originally, these pathologies were defined as glomerular pathology characterized by accumulation of C3 with absent or scanty immunoglobulin deposition. The keystone defect in both of these pathologies is the unregulated hyperactivity of alternative complement pathway. Specifically, in C3 glomerulopathy patients, there exists a prolongation of C3 cleavage which causes the uncontrolled alternative pathway activation. Many treatments have been investigated for treating C3 glomerulopathy to little or no avail, including calcineurin inhibitors, plasmapharesis, and anti-CD20 monoclonal antibodies. The next logical step is exploring the efficacy of anti-C5 monoclonal antibody therapy in C3 glomerulopathies to target the specific pathophysiology of this particular disease. Eculizumab is an anti-C5 monoclonal antibody that blocks the terminal step of complement activation. This drug has proven to be an effective treatment in other nephrologic pathologies that are caused by complement dysregulation. Here in this paper we discuss and present various case studies and clinical trials available that experiment with Eculizumab in patients with either dense deposit disease or C3 glomerulonephritis. In most of these patients, treatment with Eculizumab has demonstrated clinical and biochemical improvements in kidney function. These results provide encouraging evidence that suggest Eculizumab as a promising therapy for patients with C3 glomerulopathy and warrant that more extensive clinical trials can be designed as a next step.展开更多
Quantitative structure activity relationship （QSAR） studies were performed on 45 anthranilic acid derivatives for their potent allosteric inhibition activities of HCV NSSB polymerase. Genetic algorithm based genetic...Quantitative structure activity relationship （QSAR） studies were performed on 45 anthranilic acid derivatives for their potent allosteric inhibition activities of HCV NSSB polymerase. Genetic algorithm based genetic function approximation （GFA） method of variable selection was used to generate the model. Highly statistically significant model with r^2 = 0.966 and r^2cv = 0.951 was obtained when the number of descriptors in the equation was set to 5. High r^2pred value of 0.884 indicates the good predictive power of the best model. Spatial descriptors of radius of gyration （RadOfGration）, molecular volume （Vm）, length of molecule in the z dimension （Shadow-Zlength）, thermodynamic descriptors of the octanol/water partition coefficient （LogP） and molecular refractivity index （MR） showed enormous contributions to HCV NS5B polymerase inhibition. The validation of the model was done by leave-one-out （LOO） test, randomization tests and external test set prediction. The model gives insight on indispensable structural requirements for the activity and can be used to design more potent analogs against HCV NSSB polymerase.展开更多
The innate immune response is a complex process involving multiple pathogen-recognition receptors, including toll-like receptors (TLRs) and nucleotide-binding oligomerization domain (NOD)-like receptors. Complement is...The innate immune response is a complex process involving multiple pathogen-recognition receptors, including toll-like receptors (TLRs) and nucleotide-binding oligomerization domain (NOD)-like receptors. Complement is also a critical component of innate immunity. While complement is known to interact with TLR-mediated signals, the interactions between NOD-like receptors and complement are not well understood. Here we report a synergistic interaction between C5a and Nod2 signaling in RAW 264.7 marophages. Long-term treatment with muramyl dipeptide (MDP), a NOD2 ligand, enhanced C5a-mediated expression of chemokine mRNAs in RAW 264.7 cells. This response was dependent on NOD2 expression and was associated with a decrease in expression of C5L2, a receptor for C5a which acts as a negative modulator of C5a receptor (C5aR) activity. MDP amplified C5a-mediated phosphorylation of p38 MAPK. Treatment of RAW264.7 cells with an inhibitor of p38 attenuated the synergistic effects of C5aon MDP-primed cells on MIP-2, but not MCP-1, mRNA. In contrast, inhibition of AKT prevented C5a stimulation of MCP-1, but not MIP-2, mRNA, in MDP-primed cells. Taken together, these data demonstrated a synergistic interaction between C5a and NOD2 in the regulation of chemokine expression in macrophages, associated with a down-regulation of C5L2, a negative regulator of C5a receptor activity.展开更多
AIM： To determine whether complement membrane attack complex （C5b-9） has a pathogenic role in tubuloin-terstitial injury in a renal disease model characterized by acute highly selective proteinuria. METHODS： Prote...AIM： To determine whether complement membrane attack complex （C5b-9） has a pathogenic role in tubuloin-terstitial injury in a renal disease model characterized by acute highly selective proteinuria. METHODS： Protein-overload nephropathy （PON） was induced in adult female Piebald-Viral-Glaxo rats with or without complement C6 defciency （C6- and C6＋） by daily intraperitoneal injections of bovine serum albumin （BSA, 2 g/d）, and examined on days 2, 4 and 8.RESULTS： Groups with PON developed equivalent levels of heavy proteinuria within 24 h of BSA injection. In C6＋ rats with PON, the tubulointerstitial expression of C5b-9 was increased and localized predominantly to the basolateral surface of tubular epithelial cells （TECs）, whereas it was undetectable in C6- animals. TEC proliferation （as assessed by the number of BrdU＋cells） increased by more than 50-fold in PON, peaking on day 2 and declining on days 4 to 8. There was a trend for a reduction in the number of BrdU＋ TECs on day 4 in the C6- PON group （ P = 0.10 compared to C6＋） but not at any other time-point. Kidney enlargement, TEC apoptosis （TUNEL＋ cells） and markers of tubular injury （tubule dilatation, loss of TEC height, protein cast formation） were not altered by C6 deficiency in PON. Interstitial monocyte （ED-1＋ cell） accumulation was partially reduced in C6- animals with PON on day 4 （ P = 0.01） but there was no change in myofbroblast accumulation. CONCLUSION： These data suggest that C5b-9 does not mediate tubulointerstitial injury in acute glomerular diseases characterized by selective proteinuria.展开更多
Using isoelective focusing in immobilized pH gradients and immunoblot, C3 phenotypes (F, FS, S) and C3 HAV4-1 monoclonal (F±S±) phenotypes were performed in 90 patients with IgA glomerulonephrits,(G.N.).incl...Using isoelective focusing in immobilized pH gradients and immunoblot, C3 phenotypes (F, FS, S) and C3 HAV4-1 monoclonal (F±S±) phenotypes were performed in 90 patients with IgA glomerulonephrits,(G.N.).including 49 IgA G. N.hypertensive (H.T.) patients and 41 IgA G. N. normotensive (N.T.) patients, and in 224 normal subjects (N.S.). A significant difference of C3 phenotype distribution between both IgA G. N.(hypertensive and normotensive) and N. S. was .found (P<0.01,P<0.01respectively).In monoclonal C3 HAV4-1(±) distribution significant difference between IgA H. T.and N.S.was observed (P<0.01). Furthermore, F and S allele .frequency of IgA G. N. including HT and NT is significantly. different (P<0.05). This data suggests that hypertensive patients with IgA G. N. seems to be related io the abnormal C3 genetic factors and if this gene distributions can be used as a predictor for the prognosis still needs futher investigations.展开更多
Background:Neovascular age-related macular degeneration(AMD)and polypoidal choroidal vasculopathy(PCV)are sight-threatening maculopathies with both environmental and genetic risk factors.We have previously shown relat...Background:Neovascular age-related macular degeneration(AMD)and polypoidal choroidal vasculopathy(PCV)are sight-threatening maculopathies with both environmental and genetic risk factors.We have previously shown relative risks posed by genes of the complement pathways to neovascular AMD and PCV.Methods:In this study,we investigated the haplotype-tagging single nucleotide polymorphisms(SNPs)in the complement component 5(C5)gene in 708 unrelated Chinese individuals:200 neovascular AMD patients,233 PCV patients and 275 controls.Six tagging SNPs in C5 were genotyped.Univariate single SNP association analysis,haplotype-based association analysis and gene-gene interaction analysis between C5 and other AMD-associated genes were performed.Results:The results revealed none of the six tagging SNPs of the C5 gene had a significant association with neovascular AMD or PCV(P>0.05).We also found insignificant haplotype-based association,and no significant SNPSNP interaction between C5 and other genes(including C2-CFB-RDBP-SKIV2L,SERPING1,CETP,ABCG1,PGF,ANGPT2,CFH and HTRA1)for neovascular AMD and PCV.Conclusions:This study showed no statistical significance in the genetic association of C5 with neovascular AMD or PCV in a Hong Kong Chinese population.Further studies in large samples from different populations are warranted to elucidate the role of C5 in the genetic susceptibility of AMD and PCV.展开更多
The complement C5 anaphylatoxin receptor is a member of the seven transmembrane-spanning G protein-coupled receptor superfamily that signals through Gcxi and Gtz16. C5aR is mostly expressed on neutrophils, macrophages...The complement C5 anaphylatoxin receptor is a member of the seven transmembrane-spanning G protein-coupled receptor superfamily that signals through Gcxi and Gtz16. C5aR is mostly expressed on neutrophils, macrophages and endothelial cells. C5a and C5aR interaction plays an important role in numerous biological effects such as in vivo cytokine storm which results in inflammatory damage. Considering the limitation of collection of human peripheral blood neutrophils and their short half life, the stably transfected cell line for studying the biological effects of C5aR is needed. In this study, we transfected C5aR gene into Molt-4 cell line and examined the function of ectopic C5aR. Our results showed stable expression of the C5aR in Molt-4 cell line and their interaction with human C5a induced ERKI/2 phosphorylation, Ca＋＋ influx. This stable transfected cell line may provide a useful tool for studying signal pathways related to C5a and C5aR interplay and antibody development specific for C5aR. Cellular ＆ Molecular Immunology.展开更多
文摘C3 glomerulopathy is a disease including both dense deposit disease and C3 glomerulonephritis has an estimated prevalence of 2 to 3 per million. Originally, these pathologies were defined as glomerular pathology characterized by accumulation of C3 with absent or scanty immunoglobulin deposition. The keystone defect in both of these pathologies is the unregulated hyperactivity of alternative complement pathway. Specifically, in C3 glomerulopathy patients, there exists a prolongation of C3 cleavage which causes the uncontrolled alternative pathway activation. Many treatments have been investigated for treating C3 glomerulopathy to little or no avail, including calcineurin inhibitors, plasmapharesis, and anti-CD20 monoclonal antibodies. The next logical step is exploring the efficacy of anti-C5 monoclonal antibody therapy in C3 glomerulopathies to target the specific pathophysiology of this particular disease. Eculizumab is an anti-C5 monoclonal antibody that blocks the terminal step of complement activation. This drug has proven to be an effective treatment in other nephrologic pathologies that are caused by complement dysregulation. Here in this paper we discuss and present various case studies and clinical trials available that experiment with Eculizumab in patients with either dense deposit disease or C3 glomerulonephritis. In most of these patients, treatment with Eculizumab has demonstrated clinical and biochemical improvements in kidney function. These results provide encouraging evidence that suggest Eculizumab as a promising therapy for patients with C3 glomerulopathy and warrant that more extensive clinical trials can be designed as a next step.
基金supported by the National Natural Science Foundation of China (No. 30500339)Natural Science Foundation of Zhejiang Province (NO.Y407308)the Sprout Talented Project Program of Zhejiang Province (No. 2008R40G2020019)
文摘Quantitative structure activity relationship （QSAR） studies were performed on 45 anthranilic acid derivatives for their potent allosteric inhibition activities of HCV NSSB polymerase. Genetic algorithm based genetic function approximation （GFA） method of variable selection was used to generate the model. Highly statistically significant model with r^2 = 0.966 and r^2cv = 0.951 was obtained when the number of descriptors in the equation was set to 5. High r^2pred value of 0.884 indicates the good predictive power of the best model. Spatial descriptors of radius of gyration （RadOfGration）, molecular volume （Vm）, length of molecule in the z dimension （Shadow-Zlength）, thermodynamic descriptors of the octanol/water partition coefficient （LogP） and molecular refractivity index （MR） showed enormous contributions to HCV NS5B polymerase inhibition. The validation of the model was done by leave-one-out （LOO） test, randomization tests and external test set prediction. The model gives insight on indispensable structural requirements for the activity and can be used to design more potent analogs against HCV NSSB polymerase.
文摘The innate immune response is a complex process involving multiple pathogen-recognition receptors, including toll-like receptors (TLRs) and nucleotide-binding oligomerization domain (NOD)-like receptors. Complement is also a critical component of innate immunity. While complement is known to interact with TLR-mediated signals, the interactions between NOD-like receptors and complement are not well understood. Here we report a synergistic interaction between C5a and Nod2 signaling in RAW 264.7 marophages. Long-term treatment with muramyl dipeptide (MDP), a NOD2 ligand, enhanced C5a-mediated expression of chemokine mRNAs in RAW 264.7 cells. This response was dependent on NOD2 expression and was associated with a decrease in expression of C5L2, a receptor for C5a which acts as a negative modulator of C5a receptor (C5aR) activity. MDP amplified C5a-mediated phosphorylation of p38 MAPK. Treatment of RAW264.7 cells with an inhibitor of p38 attenuated the synergistic effects of C5aon MDP-primed cells on MIP-2, but not MCP-1, mRNA. In contrast, inhibition of AKT prevented C5a stimulation of MCP-1, but not MIP-2, mRNA, in MDP-primed cells. Taken together, these data demonstrated a synergistic interaction between C5a and NOD2 in the regulation of chemokine expression in macrophages, associated with a down-regulation of C5L2, a negative regulator of C5a receptor activity.
基金Supported by The United States National Institutes of Health(Nos.DK34198 and DK07467)to Dr.CouserThe Don Jacquot Fellowship(Australian and New Zealand Society of Nephrology Travelling Fellowship)+3 种基金The BJ Amos Travelling Fellowships(Westmead Hospital)The Medical Research Fund of Western AustraliaThe Fremantle Hospital Medical Research FoundationThe National Health and Medical Research Council(No.230500)to Dr.Rangan
文摘AIM： To determine whether complement membrane attack complex （C5b-9） has a pathogenic role in tubuloin-terstitial injury in a renal disease model characterized by acute highly selective proteinuria. METHODS： Protein-overload nephropathy （PON） was induced in adult female Piebald-Viral-Glaxo rats with or without complement C6 defciency （C6- and C6＋） by daily intraperitoneal injections of bovine serum albumin （BSA, 2 g/d）, and examined on days 2, 4 and 8.RESULTS： Groups with PON developed equivalent levels of heavy proteinuria within 24 h of BSA injection. In C6＋ rats with PON, the tubulointerstitial expression of C5b-9 was increased and localized predominantly to the basolateral surface of tubular epithelial cells （TECs）, whereas it was undetectable in C6- animals. TEC proliferation （as assessed by the number of BrdU＋cells） increased by more than 50-fold in PON, peaking on day 2 and declining on days 4 to 8. There was a trend for a reduction in the number of BrdU＋ TECs on day 4 in the C6- PON group （ P = 0.10 compared to C6＋） but not at any other time-point. Kidney enlargement, TEC apoptosis （TUNEL＋ cells） and markers of tubular injury （tubule dilatation, loss of TEC height, protein cast formation） were not altered by C6 deficiency in PON. Interstitial monocyte （ED-1＋ cell） accumulation was partially reduced in C6- animals with PON on day 4 （ P = 0.01） but there was no change in myofbroblast accumulation. CONCLUSION： These data suggest that C5b-9 does not mediate tubulointerstitial injury in acute glomerular diseases characterized by selective proteinuria.
文摘Using isoelective focusing in immobilized pH gradients and immunoblot, C3 phenotypes (F, FS, S) and C3 HAV4-1 monoclonal (F±S±) phenotypes were performed in 90 patients with IgA glomerulonephrits,(G.N.).including 49 IgA G. N.hypertensive (H.T.) patients and 41 IgA G. N. normotensive (N.T.) patients, and in 224 normal subjects (N.S.). A significant difference of C3 phenotype distribution between both IgA G. N.(hypertensive and normotensive) and N. S. was .found (P<0.01,P<0.01respectively).In monoclonal C3 HAV4-1(±) distribution significant difference between IgA H. T.and N.S.was observed (P<0.01). Furthermore, F and S allele .frequency of IgA G. N. including HT and NT is significantly. different (P<0.05). This data suggests that hypertensive patients with IgA G. N. seems to be related io the abnormal C3 genetic factors and if this gene distributions can be used as a predictor for the prognosis still needs futher investigations.
基金supported in part by the General Research Fund,Hong Kong(14120516[LJC])the Direct Grant of Chinese University of Hong Kong Medical Panel,Hong Kong(4054281[LJC])the Endowment Fund for Lim Por-Yen Eye Genetics Research Centre,Hong Kong.
文摘Background:Neovascular age-related macular degeneration(AMD)and polypoidal choroidal vasculopathy(PCV)are sight-threatening maculopathies with both environmental and genetic risk factors.We have previously shown relative risks posed by genes of the complement pathways to neovascular AMD and PCV.Methods:In this study,we investigated the haplotype-tagging single nucleotide polymorphisms(SNPs)in the complement component 5(C5)gene in 708 unrelated Chinese individuals:200 neovascular AMD patients,233 PCV patients and 275 controls.Six tagging SNPs in C5 were genotyped.Univariate single SNP association analysis,haplotype-based association analysis and gene-gene interaction analysis between C5 and other AMD-associated genes were performed.Results:The results revealed none of the six tagging SNPs of the C5 gene had a significant association with neovascular AMD or PCV(P>0.05).We also found insignificant haplotype-based association,and no significant SNPSNP interaction between C5 and other genes(including C2-CFB-RDBP-SKIV2L,SERPING1,CETP,ABCG1,PGF,ANGPT2,CFH and HTRA1)for neovascular AMD and PCV.Conclusions:This study showed no statistical significance in the genetic association of C5 with neovascular AMD or PCV in a Hong Kong Chinese population.Further studies in large samples from different populations are warranted to elucidate the role of C5 in the genetic susceptibility of AMD and PCV.
基金supported by the grants from the National Key Basic Research Program of China(2007CB512406)the National Natural Science Foundation of China(30571732)National"863"Fund Grant of China(2006AA02A254).
文摘The complement C5 anaphylatoxin receptor is a member of the seven transmembrane-spanning G protein-coupled receptor superfamily that signals through Gcxi and Gtz16. C5aR is mostly expressed on neutrophils, macrophages and endothelial cells. C5a and C5aR interaction plays an important role in numerous biological effects such as in vivo cytokine storm which results in inflammatory damage. Considering the limitation of collection of human peripheral blood neutrophils and their short half life, the stably transfected cell line for studying the biological effects of C5aR is needed. In this study, we transfected C5aR gene into Molt-4 cell line and examined the function of ectopic C5aR. Our results showed stable expression of the C5aR in Molt-4 cell line and their interaction with human C5a induced ERKI/2 phosphorylation, Ca＋＋ influx. This stable transfected cell line may provide a useful tool for studying signal pathways related to C5a and C5aR interplay and antibody development specific for C5aR. Cellular ＆ Molecular Immunology.
