1
|
Translational science in albuminuria: a new view of de novo albuminuria under chronic RAS suppression. Clin Sci (Lond) 2018; 132:739-758. [DOI: 10.1042/cs20180097] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 03/09/2018] [Accepted: 03/22/2018] [Indexed: 12/29/2022]
Abstract
The development of de novo albuminuria during chronic renin–angiotensin system (RAS) suppression is a clinical entity that remains poorly recognized in the biomedical literature. It represents a clear increment in global cardiovascular (CV) and renal risk that cannot be counteracted by RAS suppression. Although not specifically considered, it is clear that this entity is present in most published and ongoing trials dealing with the different forms of CV and renal disease. In this review, we focus on the mechanisms promoting albuminuria, and the predictors and new markers of de novo albuminuria, as well as the potential treatment options to counteract the excretion of albumin. The increase in risk that accompanies de novo albuminuria supports the search for early markers and predictors that will allow practising physicians to assess and prevent the development of de novo albuminuria in their patients.
Collapse
|
2
|
Nilojan J, Bathige SDNK, Thulasitha WS, Kwon H, Jung S, Kim MJ, Nam BH, Lee J. Transcriptional profiling, molecular cloning, and functional analysis of C1 inhibitor, the main regulator of the complement system in black rockfish, Sebastes schlegelii. FISH & SHELLFISH IMMUNOLOGY 2018; 75:263-273. [PMID: 29444464 DOI: 10.1016/j.fsi.2018.02.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 02/06/2018] [Accepted: 02/08/2018] [Indexed: 06/08/2023]
Abstract
C1-inhibitor (C1inh) plays a crucial role in assuring homeostasis and is the central regulator of the complement activation involved in immunity and inflammation. A C1-inhibitor gene from Sebastes schlegelii was identified and designated as SsC1inh. The identified genomic DNA and cDNA sequences were 6837 bp and 2161 bp, respectively. The genomic DNA possessed 11 exons, interrupted by 10 introns. The amino acid sequence possessed two immunoglobulin-like domains and a serpin domain. Multiple sequence alignment revealed that the serpin domain of SsC1inh was highly conserved among analyzed species where the two immunoglobulin-like domains showed divergence. The distinctiveness of teleost C1inh from other homologs was indicated by the phylogenetic analysis, genomic DNA organization, and their extended N-terminal amino acid sequences. Under normal physiological conditions, SsC1inh mRNA was most expressed in the liver, followed by the gills. The involvement of SsC1inh in homeostasis was demonstrated by modulated transcription profiles in the liver and spleen upon pathogenic stress by different immune stimulants. The protease inhibitory potential of recombinant SsC1inh (rSsC1inh) and the potentiation effect of heparin on rSsC1inh was demonstrated against C1esterase and thrombin. For the first time, the anti-protease activity of the teleost C1inh against its natural substrates C1r and C1s was proved in this study. The protease assay conducted with recombinant black rockfish C1r and C1s proteins in the presence or absence of rSsC1inh showed that the activities of both proteases were significantly diminished by rSsC1inh. Taken together, results from the present study indicate that SsC1inh actively plays a significant role in maintaining homeostasis in the immune system of black rock fish.
Collapse
Affiliation(s)
- Jehanathan Nilojan
- Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province, 63243, Republic of Korea
| | - S D N K Bathige
- Sri Lanka Institute of Nanotechnology (SLINTEC), Nanotechnology and Science Park, Mahenwatta, Pitipana, Homagama, Sri Lanka
| | - W S Thulasitha
- Department of Zoology, University of Jaffna, Jaffna, 40000, Sri Lanka
| | - Hyukjae Kwon
- Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province, 63243, Republic of Korea
| | - Sumi Jung
- Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province, 63243, Republic of Korea
| | - Myoung-Jin Kim
- Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province, 63243, Republic of Korea
| | - Bo-Hye Nam
- Biotechnology Research Division, National Institute of Fisheries Science, 408-1 Sirang-ri, Gijang-up, Gijang-gun, Busan, 46083, Republic of Korea
| | - Jehee Lee
- Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province, 63243, Republic of Korea.
| |
Collapse
|
3
|
Abstract
The complement system normally eliminates bacteria and has a protective effect. However, in an inflammatory setting such as sepsis, an exaggerated or insufficient activation of this cascade can have deleterious effect through the activation of glial cells, secretion of proinflammatory cytokines and generation of other toxic products. The aim of the present study was to investigate the role of the complement cascade in septic encephalopathy, through the passive injection of endotoxin/lipopolysaccharide (LPS) into mice overexpressing the potent complement inhibitor, CR1-related y (Crry-tg). Increased gliosis occurred in brains of endotoxemic mice. Concomitant with this, there was a significant rise in mRNA expression of GFAP, CD45 and proinflammatory molecules, TLR4, TNF-alpha and NO, in these brains. Consistent with the capacity of these inflammatory mediators, there was increased apoptosis as determined by DNA fragmentation and TUNEL staining on LPS treatment, which occurred through the Akt pathway. In addition, there was increased water content in brain, similar to cerebral edema observed in sepsis. Relative to wild-type mice, complement-inhibited mice had an attenuated inflammatory response, decreased edema and reduced apoptosis. Therefore, we demonstrate for the first time that the complement cascade appears to be one of the key players that cause brain pathology in an endotoxemic setting and therefore is a viable therapeutic target.
Collapse
|
4
|
Alexander JJ, Zwingmann C, Jacob A, Quigg R. Alteration in kidney glucose and amino acids are implicated in renal pathology in MRL/lpr mice. Biochim Biophys Acta Mol Basis Dis 2007; 1772:1143-9. [DOI: 10.1016/j.bbadis.2007.07.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2007] [Revised: 07/16/2007] [Accepted: 07/23/2007] [Indexed: 12/25/2022]
|
5
|
Alexander JJ, Jacob A, Bao L, Macdonald RL, Quigg RJ. Complement-dependent apoptosis and inflammatory gene changes in murine lupus cerebritis. THE JOURNAL OF IMMUNOLOGY 2006; 175:8312-9. [PMID: 16339572 DOI: 10.4049/jimmunol.175.12.8312] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The role of complement activation in the brains of MRL/lpr lupus mice was determined using the potent C3 convertase inhibitor, CR1-related y (Crry), administered both as an overexpressing Crry transgene and as Crry-Ig. Prominent deposition of complement proteins C3 and C9 in brains of MRL/lpr mice was indicative of complement activation and was significantly reduced by Crry. Apoptosis was determined in brain using different independent measures of apoptosis, including TUNEL staining, DNA laddering, and caspase-3 activity, all of which were markedly increased in lupus mice and could be blocked by inhibiting complement with Crry. Complement activation releases inflammatory mediators that can induce apoptosis. The mRNA for potentially proinflammatory proteins such as TNFR1, inducible NO synthase, and ICAM-1 were up-regulated in brains of lupus mice. Crry prevented the increased expression of these inflammatory molecules, indicating that the changes were complement dependent. Furthermore, microarray analysis revealed complement-dependent up-regulation of glutamate receptor (AMPA-GluR) expression in lupus brains, which was also validated for AMPA-GluR1 mRNA and protein. Our results clearly demonstrate that apoptosis is a prominent feature in lupus brains. Complement activation products either directly and/or indirectly through TNFR1, ICAM-1, inducible NO synthase, and AMPA-GluR, all of which were altered in MRL/lpr mouse brains, have the potential to induce such apoptosis. These findings present the exciting possibility that complement inhibition is a therapeutic option for lupus cerebritis.
Collapse
Affiliation(s)
- Jessy J Alexander
- Section of Nephrology, Department of Medicine, University of Chicago, IL 60637, USA.
| | | | | | | | | |
Collapse
|
6
|
Yu CY, Chung EK, Yang Y, Blanchong CA, Jacobsen N, Saxena K, Yang Z, Miller W, Varga L, Fust G. Dancing with complement C4 and the RP-C4-CYP21-TNX (RCCX) modules of the major histocompatibility complex. ACTA ACUST UNITED AC 2004; 75:217-92. [PMID: 14604014 DOI: 10.1016/s0079-6603(03)75007-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The number of the complement component C4 genes varies from 2 to 8 in a diploid genome among different human individuals. Three quarters of the C4 genes in Caucasian populations have the endogenous retrovirus, HERV-K(C4), in the ninth intron. The remainder does not. The C4 serum proteins are highly polymorphic and their concentrations vary from 100 to approximately 1000 microg/ml. There are two distinct classes of C4 protein, C4A and C4B, which have diversified to fulfill (a) the opsonization/immunoclearance purposes and (b) the well-known complement function in the killing of microbes by lysis and neutralization, respectively. Many infectious and autoimmune diseases are associated with complete or partial deficiency of C4A and/or C4B. The adverse effects of high C4 gene dosages, however, are just emerging, as the concepts of human C4 genetics are revised and accurate techniques are applied to distinguish partial deficiencies from differential expression caused by unequal C4A and C4B gene dosages and gene sizes. This review attempts to dissect the sophisticated genetics of complement C4A and C4B. The emphases are on the qualitative and quantitative diversities of C4 genotypes and phenotypes. The many allotypic variants and the processed products of human and mouse C4 proteins are described. The modular variation of C4 genes together with the serine/threonine nuclear kinase gene RP, the steroid 21-hydroxylase CYP21, and extracellular matrix protein TNX (RCCX modules) are investigated for the effects on homogenization of C4 protein polymorphisms, and on the unequal genetic crossovers that knocked out the functions of CYP21 and/or TNX. Furthermore, the influence of the endogenous retrovirus HERV-K(C4) on C4 gene expression and the dispersal of HERV-K(C4) family members in the human genome are discussed.
Collapse
Affiliation(s)
- C Yung Yu
- Center for Molecular and Human Genetics, Columbus Children's Research Institute, 700 Children's Drive, Columbus, OH 43205-2696, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Banda NK, Kraus DM, Muggli M, Bendele A, Holers VM, Arend WP. Prevention of collagen-induced arthritis in mice transgenic for the complement inhibitor complement receptor 1-related gene/protein y. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 171:2109-15. [PMID: 12902517 DOI: 10.4049/jimmunol.171.4.2109] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The objective of these studies was to examine collagen-induced arthritis (CIA) in C57BL/6 mice transgenic for the rodent complement regulatory protein complement receptor 1-related gene/protein y (Crry) (Crry-Tg), a C3 convertase inhibitor. The scores for clinical disease activity and for histological damage in the joints were both significantly decreased in Crry-Tg mice in comparison to wild-type (WT) littermates. The production of both IgG1 and IgG2a anti-collagen Abs was reduced in the Crry-Tg mice, although spleen cell proliferation in response to collagen type II was not altered. The production of IFN-gamma, TNF-alpha, and IL-1beta by LPS-stimulated spleen cells was decreased, and IL-10 was increased, in cells from Crry-Tg mice in comparison to WT. The steady-state mRNA levels for IFN-gamma, TNF-alpha, and IL-1beta were all decreased in the joints of Crry-Tg mice in comparison to WT. The synovium from Crry-Tg mice without CIA contained the mRNA for the Crry transgene, by RT-PCR, and the synovium from transgenic mice with CIA exhibited little deposition of C3 protein by immunohistological analysis. These results suggest that suppression of CIA in Crry-Tg mice may be due to enhanced synthesis of Crry locally in the joint with decreased production of proinflammatory cytokines.
Collapse
MESH Headings
- Animals
- Arthritis, Experimental/genetics
- Arthritis, Experimental/immunology
- Arthritis, Experimental/pathology
- Arthritis, Experimental/prevention & control
- Autoantibodies/biosynthesis
- Autoantibodies/blood
- Cattle
- Collagen Type II/administration & dosage
- Collagen Type II/immunology
- Complement Inactivator Proteins/genetics
- Cytokines/biosynthesis
- Female
- Hindlimb
- Immunoglobulin G/biosynthesis
- Immunoglobulin G/blood
- Immunohistochemistry
- Injections, Intradermal
- Lymph Nodes/cytology
- Lymph Nodes/immunology
- Lymphocyte Activation/genetics
- Lymphocyte Subsets/immunology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- RNA, Messenger/analysis
- Receptors, Complement/biosynthesis
- Receptors, Complement/genetics
- Receptors, Complement 3b/genetics
- Spleen/cytology
- Spleen/immunology
- Spleen/metabolism
Collapse
Affiliation(s)
- Nirmal K Banda
- Division of Rheumatology, University of Colorado Health Sciences Center, Denver, CO 80262. BolderPATH, Boulder, CO 80309, USA
| | | | | | | | | | | |
Collapse
|
8
|
Aslam M, Guthridge JM, Hack BK, Quigg RJ, Holers VM, Perkins SJ. The extended multidomain solution structures of the complement protein Crry and its chimeric conjugate Crry-Ig by scattering, analytical ultracentrifugation and constrained modelling: implications for function and therapy. J Mol Biol 2003; 329:525-50. [PMID: 12767833 DOI: 10.1016/s0022-2836(03)00492-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Complement receptor-related gene/protein y (Crry) is a cell membrane-bound regulator of complement activation found in mouse and rat. Crry contains only short complement/consensus repeat (SCR) domains. X-ray and neutron scattering was performed on recombinant rat Crry containing the first five SCR domains (rCrry) and mouse Crry with five SCR domains conjugated to the Fc fragment of mouse IgG1 (mCrry-Ig) in order to determine their solution structures at medium resolution. The radius of gyration R(G) of rCrry was determined to be 4.9-5.0 nm, and the R(G) of the cross-section was 1.2-1.5 nm as determined by X-ray and neutron scattering. The R(G) of mCrry-Ig was 6.6-6.7 nm, and the R(G) of the cross-section were 2.3-2.4 nm and 1.3 nm. The maximum dimension of rCrry was 18 nm and that for mCrry-Ig was 26 nm. The neutron data indicated that rCrry and mCrry-Ig have molecular mass values of 45,000 Da and 140,000 Da, respectively, in agreement with their sequences, and sedimentation equilibrium data supported these determinations. Time-derivative velocity experiments gave sedimentation coefficients of 2.4S for rCrry and 5.4S for mCrry-Ig. A medium-resolution model of rCrry was determined using homology models that were constructed for the first five SCR domains of Crry from known crystal and NMR structures, and linked by randomly generated linker peptide conformations. These trial-and-error calculations revealed a small family of extended rCrry structures that best accounted for the scattering and ultracentrifugation data. These were shorter than the most extended rCrry models as the result of minor bends in the inter-SCR orientations. The mCrry-Ig solution data were modelled starting from a fixed structure for rCrry and the crystal structure of mouse IgG1, and was based on conformational searches of the hinge peptide joining the mCrry and Fc fragments. The best-fit models showed that the two mCrry antennae in mCrry-Ig were extended from the Fc fragment. No preferred orientation of the antennae was identified, and this indicated that the accessibility of the antennae for the molecular targets C4b and C3b was not affected by the covalent link to Fc. A structural comparison between Crry and complement receptor type 1 indicated that the domain arrangement of Crry SCR 1-3 is as extended as that of the CR1 SCR 15-17 NMR structure.
Collapse
Affiliation(s)
- Mohammed Aslam
- Department of Biochemistry and Molecular Biology, Darwin Building, University College London, Gower Street, London WC1E 6BT, UK
| | | | | | | | | | | |
Collapse
|
9
|
Wyss-Coray T, Yan F, Lin AHT, Lambris JD, Alexander JJ, Quigg RJ, Masliah E. Prominent neurodegeneration and increased plaque formation in complement-inhibited Alzheimer's mice. Proc Natl Acad Sci U S A 2002; 99:10837-42. [PMID: 12119423 PMCID: PMC125059 DOI: 10.1073/pnas.162350199] [Citation(s) in RCA: 328] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2002] [Accepted: 06/11/2002] [Indexed: 01/08/2023] Open
Abstract
Abnormal accumulation of beta-amyloid (Abeta) in Alzheimer's disease (AD) is associated with prominent brain inflammation. Whereas earlier studies concluded that this inflammation is detrimental, more recent animal data suggest that at least some inflammatory processes may be beneficial and promote Abeta clearance. Consistent with these observations, overproduction of transforming growth factor (TGF)-beta1 resulted in a vigorous microglial activation that was accompanied by at least a 50% reduction in Abeta accumulation in human amyloid precursor protein (hAPP) transgenic mice. In a search for inflammatory mediators associated with this reduced pathology, we found that brain levels of C3, the central component of complement and a key inflammatory protein activated in AD, were markedly higher in hAPP/TGF-beta1 mice than in hAPP mice. To assess the importance of complement in the pathogenesis of AD-like disease in mice, we inhibited C3 activation by expressing soluble complement receptor-related protein y (sCrry), a complement inhibitor, in the brains of hAPP mice. Abeta deposition was 2- to 3-fold higher in 1-year-old hAPP/sCrry mice than in age-matched hAPP mice and was accompanied by a prominent accumulation of degenerating neurons. These results indicate that complement activation products can protect against Abeta-induced neurotoxicity and may reduce the accumulation or promote the clearance of amyloid and degenerating neurons. These findings provide evidence for a role of complement and innate immune responses in AD-like disease in mice and support the concept that certain inflammatory defense mechanisms in the brain may be beneficial in neurodegenerative disease.
Collapse
Affiliation(s)
- Tony Wyss-Coray
- Gladstone Institute of Neurological Disease, University of California, San Francisco, CA 94141, USA.
| | | | | | | | | | | | | |
Collapse
|
10
|
Bao L, Haas M, Boackle SA, Kraus DM, Cunningham PN, Park P, Alexander JJ, Anderson RK, Culhane K, Holers VM, Quigg RJ. Transgenic expression of a soluble complement inhibitor protects against renal disease and promotes survival in MRL/lpr mice. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 168:3601-7. [PMID: 11907125 DOI: 10.4049/jimmunol.168.7.3601] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
To investigate the role of complement in lupus nephritis, we used MRL/lpr mice and a transgene overexpressing a soluble complement regulator, soluble CR1-related gene/protein y (sCrry), both systemically and in kidney. Production of sCrry in sera led to significant complement inhibition in Crry-transgenic mice relative to littermate transgene negative controls. This complement inhibition with sCrry conferred a survival advantage to MRL/lpr mice. In a total of 154 animals, 42.5% transgene-negative animals had impaired renal function (blood urea nitrogen > 50 mg/dl) compared with 16.4% mice with the sCrry-producing transgene (p < 0.001). In those animals that died spontaneously, MRL/lpr mice with the sCrry-producing transgene did not die of renal failure, while those without the transgene did (blood urea nitrogen values of 46.6 +/- 9 and 122 +/- 29 mg/dl in transgene-positive and transgene-negative animals, respectively; p < 0.001). Albuminuria was reduced in those transgenic animals in which sCrry expression was maximally stimulated (urinary albumin/creatinine = 12.4 +/- 4.3 and 36.9 +/- 7.7 in transgene-positive and transgene-negative animals, respectively; p < 0.001). As expected in the setting of chronic complement inhibition, there was less C3 deposition in glomeruli of sCrry-producing transgenic mice compared with transgene-negative animals. In contrast, there was no effect on glomerular IgG deposition, levels of anti-dsDNA Ab and rheumatoid factor, or spleen weights between the two groups. Thus, long-term complement inhibition reduces renal disease in MRL/lpr mice, which translates into improved survival. MRL/lpr mice in which complement is inhibited still have spontaneous mortality, yet this is not from renal disease.
Collapse
Affiliation(s)
- Lihua Bao
- Department of Medicine, Section of Nephrology, University of Chicago, Chicago, IL 60637, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Alexander JJ, Hack BK, Cunningham PN, Quigg RJ. A protein with characteristics of factor H is present on rodent platelets and functions as the immune adherence receptor. J Biol Chem 2001; 276:32129-35. [PMID: 11406620 DOI: 10.1074/jbc.m101299200] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Complement-coated particles interact with specific immune adherence receptors (IAR). In primates, this function is served by complement receptor 1 (CR1) on erythrocytes. In contrast, rodent platelets bear IAR distinct from CR1, the identity of which was studied here. A 150-kDa C3b-binding protein was isolated from rat platelets, which had immunochemical and biochemical identity to plasma factor H. Immunofluorescence microscopy and flow cytometry demonstrated that factor H was present on the surface of rat and mouse platelets, which could be removed by treatment with neuraminidase. Sheep erythrocytes bearing C3b underwent immune adherence with rat and mouse platelets, which was blocked with anti-factor H F(ab')(2) antibodies, but not with antibodies binding to the complement regulator, Crry, on the platelet surface. By reverse transcription-polymerase chain reaction using rat platelet RNA and primers designed from mouse factor H, a 472-base pair product was generated that was identical in sequence to that produced from rat liver RNA. The translated protein product was 85% similar to mouse liver factor H. The 3'-nucleotide sequence from platelets predicted a soluble factor H protein. By Northern analysis, liver and platelets had identically sized factor H mRNA. Thus, rat and mouse platelets have a membrane protein with characteristics of factor H that is linked via sialic acid residues and functions as the IAR. Whether platelet factor H is acquired by passive adsorption from sera and/or is produced by platelets remains to be determined.
Collapse
Affiliation(s)
- J J Alexander
- Section of Nephrology, Department of Medicine, The University of Chicago, Chicago, Illinois 60637, USA.
| | | | | | | |
Collapse
|
12
|
Schiller B, Cunningham PN, Alexander JJ, Bao L, Holers VM, Quigg RJ. Expression of a soluble complement inhibitor protects transgenic mice from antibody-induced acute renal failure. J Am Soc Nephrol 2001; 12:71-79. [PMID: 11134252 DOI: 10.1681/asn.v12171] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Crry is a potent complement regulator in rodents that inhibits C3 convertases. In rats, intrarenal arterial injection of anti-glomerular endothelial cell (GEN) antibodies leads to complement-dependent microvascular injury and acute renal failure. In this study, a mouse variant of this model and the effects of complement inhibition were examined. Transgenic mice that overexpressed soluble Crry systemically and in their kidneys were studied. Anti-GEN IgG was injected intravenously into eight Crry transgenic mice and seven transgene-negative littermates (which were used as control animals). Thirty h after injection, blood urea nitrogen (BUN) levels were 30.3 +/- 4.4 and 114.8 +/- 23.5 mg/dl for transgene-positive and -negative animals, respectively (P = 0.012). Four of five transgene-negative animals with BUN levels of > 100 mg/dl were anuric; the remaining animal exhibited minimal albuminuria and no detectable urinary C3. In animals with renal failure, glomerular capillary collapse and tubular necrosis were observed. There was significant tubular staining for C3 in transgene-negative animals, with cellular and basal distributions, both of which were statistically greater than those in transgene-positive animals. Tubular cell C3 staining was strongly correlated with BUN values (r = 0.83, P < 0.001), as was C9 staining (r = 0.56, P = 0.037), suggesting that complement activation to the C5b-9 membrane attack complex had a casual role in renal failure. Thus, systemic injection of anti-GEN antibodies into mice leads to acute renal failure, with glomerular and tubular injury. Animals that overexpress soluble Crry in renal tubules and elsewhere are protected from the acute renal failure that occurs in this model, which ultimately seems to develop because of complement activation focused on tubules.
Collapse
Affiliation(s)
- Brigitte Schiller
- Department of Medicine, Section of Nephrology, The University of Chicago, Chicago, Illinois
| | - Patrick N Cunningham
- Department of Medicine, Section of Nephrology, The University of Chicago, Chicago, Illinois
| | - Jessy J Alexander
- Department of Medicine, Section of Nephrology, The University of Chicago, Chicago, Illinois
| | - Lihua Bao
- Department of Medicine, Section of Nephrology, The University of Chicago, Chicago, Illinois
| | - V Michael Holers
- Department of Medicine, Division of Rheumatology, University of Colorado Health Sciences Center, Denver, Colorado
| | - Richard J Quigg
- Department of Medicine, Section of Nephrology, The University of Chicago, Chicago, Illinois
| |
Collapse
|
13
|
Sahu A, Lambris JD. Complement inhibitors: a resurgent concept in anti-inflammatory therapeutics. IMMUNOPHARMACOLOGY 2000; 49:133-48. [PMID: 10904113 DOI: 10.1016/s0162-3109(00)80299-4] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In addition to its essential role in immune defense, the complement system contributes to tissue damage in many clinical conditions. Thus, there is a pressing need to develop therapeutically effective complement inhibitors to prevent these adverse effects. This concept, though old, received little scientific attention until recently. Data from animal models of diseases that have been produced using complement-deficient, knockout, and transgenic animals, as well as data demonstrating that complement proteins are produced in many important tissue sites (including the brain) have attracted the interest of many basic research scientists and applied scientists from the biotechnology field and larger pharmaceutical firms. This resurgence of interest has generated a wealth of new information in the field of complement inhibition. In this article, we comprehensively review up-to-date information in the field of complement inhibitors.
Collapse
Affiliation(s)
- A Sahu
- Protein Chemistry Laboratory, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia 19104, USA
| | | |
Collapse
|