OBJECTIVETo explore the characteristics in CFHR1 concentration and the frequency of CFHR1 gene polymorphisms of patients with type 2 diabetes mellitus (T2DM) based on the high level of complement factor H (CFH) expression among such patients and the similarity between CFHR1 and CFH in terms of sequence and functions.

METHODSFifty T2DM patients and 30 healthy controls were selected. The plasma samples were separated by pI with OFFGEL electrophoresis following solution digestion. Further separation and identification were carried out on a Nano HPLC-Chip-MS/MS system. Differentially expressed proteins were identified by comparison. Enzyme-linked immunosorbent assay (ELISA) was used to validate the result. Genomic DNA of the two groups was extracted. Polymerase chain reaction and sequencing were used to determine the single nucleotide polymorphisms in the 6 exons of the CFHR1 gene.

RESULTSThe CFHR1 level in plasma of T2DM patients were significantly higher than that of the healthy controls (P=2.78× 10). A significant difference in allelic frequencies of rs12406079 of the fifth exon of the CFHR1 gene was found between the two groups (χ=5.692, P=0.017).

CONCLUSIONThe concentration of CFHR1 and frequencies of CFHR1 gene polymorphisms among patients with T2DM differ significantly from healthy subjects. Polymorphisms of the CFHR1 gene are associated with T2DM.

Complement C3b Inactivator Proteins ; genetics ; metabolism ; Diabetes Mellitus, Type 2 ; genetics ; metabolism ; Female ; Genotype ; Humans ; Male ; Middle Aged ; Polymorphism, Single Nucleotide

No abstract available.
Complement Factor H*

Complement Factor H ; genetics ; Hemolytic-Uremic Syndrome ; genetics ; Humans

BACKGROUND: We determined the changes of complement regulator gene expression in the amyloid-beta1-42(A beta1-42) and interferon-gamma(IFN-gamma)-stimulated human astrocytoma cell line. METHODS: The human astrocytoma cell line, U373MG, was stimulated with IFN-gamma(62.5-1,000U/ml) in the presence or absence of aggregated A beta1-42(1-20micrometer) for 24 hours. Messenger RNA expression of C1 inhibitor(C1-INH), complement factor I(CFI), clusterin, vitronectin, decay accelerating factor(DAF), membrane cofactor protein(MCP), and CD59 was measured by quantitative real-time reverse transcriptase-PCR. RESULTS: IFN-gamma(final concentration, 500U/ml) markedly increased the expression of mRNA for C1-INH in a time dependent fashion. A beta1-42(final concentration, 2micrometer) induced a slight increase in the expression of C1-INH. Messenger RNAs for CFI and clusterin were minimally increased, but other regulators were unchanged or decreased by either A beta1-42 or IFN-gamma. IFN-gamma overrode A beta1-42-induced mRNA expression of C1-INH when the cells were treated with these two reagents together. CONCLUSION: Among the complement regulator genes in the human astrocytoma cell line, U373MG, only C1-INH was significantly up-regulated by IFN-gamma with or without A beta1-42 administration.
Alzheimer Disease ; Aminopeptidases ; Amyloid beta-Peptides ; Astrocytoma ; Cell Line ; Clusterin ; Complement Factor I ; Complement System Proteins ; Genes, Regulator ; Humans ; Indicators and Reagents ; Interferon-gamma ; Interferons ; Membranes ; RNA, Messenger ; Vitronectin

Autoantibodies ; Child ; Complement Factor H ; immunology ; Female ; Hemolytic-Uremic Syndrome ; immunology ; Humans

We experienced a living donor liver transplantation for a 26-month-old girl with complement factor H deficiency. Complement factor H is a plasma protein that regulates the activity of the complement pathway. Complement overactivity induced by complement factor H deficiency is associated with atypical hemolytic uremic syndrome. Liver transplantation can be the proper treatment for this condition. During the liver transplantation of these patients, prevention of the complement overactivation is necessary. Minimizing complement activation, through the use of modalities such as plasma exchange before the surgery and transfusion of fresh frozen plasma throughout the entire perioperative period, may be the key for successful liver transplantation in these patients.
Child, Preschool ; Complement Activation ; Complement Factor H* ; Complement System Proteins ; Female ; Hemolytic-Uremic Syndrome* ; Humans ; Liver Transplantation* ; Living Donors* ; Perioperative Period ; Plasma ; Plasma Exchange

Complement proteins in blood recognize charged particles. The anionic phospholipid (aPL) cardiolipin binds both complement proteins C1q and factor H. C1q is an activator of the complement classical pathway, while factor H is an inhibitor of the alternative pathway. To examine opposing effects of C1q and factor H on complement activation by aPL, we surveyed C1q and factor H binding, and complement activation by aPL, either coated on microtitre plates or in liposomes. Both C1q and factor H bound to all aPL tested, and competed directly with each other for binding. All the aPL activated the complement classical pathway, but negligibly the alternative pathway, consistent with accepted roles of C1q and factor H. However, in this system, factor H, by competing directly with C1q for binding to aPL, acts as a direct regulator of the complement classical pathway. This regulatory mechanism is distinct from its action on the alternative pathway. Regulation of classical pathway activation by factor H was confirmed by measuring C4 activation by aPL in human sera in which the C1q:factor H molar ratio was adjusted over a wide range. Thus factor H, which is regarded as a down-regulator only of the alternative pathway, has a distinct role in downregulating activation of the classical complement pathway by aPL. A factor H homologue, β2-glycoprotein-1, also strongly inhibits C1q binding to cardiolipin. Recombinant globular domains of C1q A, B and C chains bound aPL similarly to native C1q, confirming that C1q binds aPL via its globular heads.
Animals ; Complement Activation ; Complement C1q ; chemistry ; metabolism ; Complement Factor H ; metabolism ; Humans ; Immunoglobulin G ; metabolism ; Mice ; Phospholipids ; chemistry ; metabolism ; Protein Binding

OBJECTIVEA R1210C mutation of complement factor H (CFH) gene has been associated with age-related macular degeneration (AMD) in Caucasian population. This study was to verify above association in Han Chinese population.

METHODSThe mutation was detected by direct sequencing in 258 patients with wet AMD and 426 matched controls.

RESULTSThe R1210C mutation has not been identified in either sample.

CONCLUSIONThe R1210C mutation in CFH gene is not associated with AMD in Han Chinese population.

Aged ; Aged, 80 and over ; Complement Factor H ; genetics ; Female ; Humans ; Macular Degeneration ; genetics ; Male ; Middle Aged ; Mutation

We have performed 3 cases of APOLT in one child and two adults. The child recipient had suffered from complement factor H deficiency since 3 months after birth and at the age of 30 months, APOLT was undertaken. Living donors of two adult recipients were affected by severe hepatic steatosis and the grafts were relatively small-for-size. After left hemihepatectomies, left lateral section and left hemilivers were transplanted orthotopically. The child recipient died of heart failure due to sepsis 7 months after transplantation, but factor H level remained nearly normal until his death. Although one adult suffered from hepatic venous stricture postoperatively, all adult recipients are alive with normal liver function for 11 and 8 months. In conclusion, although APOLT is technically demanding, APOLT may be a suitable surgical procedure in non-cirrhotic metabolic liver disease and a feasible solution for marked steatotic living donor grafts and small-for-size grafts.
Adult* ; Child ; Complement Factor H* ; Complement System Proteins* ; Constriction, Pathologic ; Heart Failure ; Humans ; Liver Diseases ; Liver Transplantation* ; Liver* ; Living Donors ; Parturition ; Sepsis ; Transplants

BACKGROUND: Atypical hemolytic uremic syndrome (aHUS) is a rare disease that is often associated with genetic defects. Mutations of complement factor H (CFH) are the most common genetic defects that cause aHUS and often result in end-stage renal disease. Since CFH is mainly produced in the liver, liver transplantation (LT) has been performed in patients with defective CFH. METHODS: The clinical courses of four kidney allograft recipients who lost their native kidney functions due to aHUS associated with a CFH mutation were reviewed. RESULTS: Subject A underwent kidney transplantation (KT) twice, aHUS recurred and the allograft kidney failed within a few years. Subject B received a KT and soon experienced a recurrence of aHUS coinciding with infection. Her allograft kidney function has worsened, and she remains on plasma infusion therapy. Subject C underwent LT followed by KT. She is doing well without plasma infusion therapy after combined LT-KT for 3 years. Subject D received KT following LT and is now recurrence-free from aHUS. CONCLUSION: In patients with aHUS associated with a CFH mutation, KT without LT was complicated with a recurrence of aHUS, which might lead to allograft loss. Conversely, LT was successful in preventing the recurrence of aHUS and thus might be another option for a recurrence-free life for aHUS patients associated with CFH mutation.
Allografts ; Atypical Hemolytic Uremic Syndrome ; Complement Factor H ; Complement System Proteins ; Humans ; Kidney Failure, Chronic ; Kidney Transplantation ; Kidney ; Liver Transplantation ; Liver ; Plasma ; Rare Diseases ; Recurrence