This study aims to investigate the mechanism of Mahuang Lianqiao Chixiaodou Decoction(MHLQ) and its main active components in treating immunoglobin A nephropathy(IgAN). The rat model of IgAN was established by a combination of measures including gavage of bovine serum albumin, subcutaneous injection of carbon tetrachloride, and tail vein injection of lipopolysaccharide. The modeled rats were randomized into model, low-, medium-, and high-dose(1.773, 3.545, and 7.090 g·kg~(-1), respectively) MHLQ, phillyrin(PHI, 0.020 g·kg~(-1)), pseudoephedrine(PSE, 0.020 g·kg~(-1)), and losartan potassium(LP, 9.003 mg·kg~(-1)) groups, and Wistar rats were used as the control. Rats were administrated with corresponding drugs by gavage, and those in the control and model groups received an equal volume of normal saline. All the groups were treated for 4 consecutive weeks. Urine, serum, liver, and kidney samples were collected from rats in each group at the end of drug administration. The 24 h urine protein and renal function were examined, and staining was performed to observe the pathological changes in the renal tissue. The immunofluorescence assay was employed to detect the expression of IgA and complement C3/C3b/C3c in the renal tissue. Electron microscopy was employed to observe the ultrastructure of the renal tissue. Enzyme-linked immunosorbent assay was performed to determine the expression of complement C3 and sublytic C5b-9 in the serum and renal tissue. Western blot was performed to determine the expression levels of hepatic and renal complement C3/C3b/C3c, C5/C5a, C5b-9, and complement factor B(CFB). Immunohistochemistry(IHC) was employed to measure the expression of complement C3 in the renal tissue. The results showed that compared with the control group, the model group had elevated levels of blood urea nitrogen and serum creatinine, proliferation of glomerular mesangial cells and extracellular matrix, and glomerular deposition of IgA immune complexes or electron-dense material. In addition, the model group showcased increased serum C3 levels and up-regulated expression of CFB, C3/C3b/C3c, C5/C5a, and C5b-9 in the renal tissue and C3/C3b/C3c and C5b-9 in the hepatic tissue. After treatment with MHLQ and its active components, all of the above indexes were reversed. In conclusion, MHLQ and its active components can improve the renal function and reduce the deposition of immune complexes and pathological damage in the renal tissue of the rat model of IgAN by inhibiting the alternative pathway complement activation.
Animals ; Drugs, Chinese Herbal/administration & dosage* ; Glomerulonephritis, IGA/genetics* ; Rats ; Male ; Disease Models, Animal ; Rats, Wistar ; Complement Activation/drug effects* ; Kidney/immunology* ; Humans

Sepsis-associated coagulopathy refers to extensive coagulation activation accompanied by a high risk of bleeding and organ failure. In severe cases, it is manifested as disseminated intravascular coagulation (DIC) and leads to multiple organ dysfunction syndrome (MODS). Complement is an important component of the innate immune system and plays an important role in defending against invasion of pathogenic microorganisms. The early pathological process of sepsis involves excessive activation of the complement system, which forms an extremely complex network through interactions with the coagulation, kinin and fibrinolytic system, amplifying and exacerbating the systemic inflammatory response. In recent years, it has been suggested that uncontrolled complement activation system can exacerbate sepsis-associated coagulation dysfunction or even DIC, indicating the potential value of intervening in the complement system in the treatment of septic DIC, and related research progress is reviewed in this article in order to provide new ideas for the discovery of sepsis-associated coagulopathy therapy drugs.
Humans ; Blood Coagulation Disorders ; Complement Activation ; Blood Coagulation ; Multiple Organ Failure ; Sepsis

CD55 Antigens ; Complement Activation ; Humans ; Membrane Cofactor Protein ; Pemphigoid, Bullous ; Recombinant Fusion Proteins

BACKGROUND: Atypical hemolytic uremic syndrome (aHUS) involves dysregulation of the complement system, but whether this also occurs in thrombotic thrombocytopenic purpura (TTP) remains unclear. Although these conditions are difficult to differentiate clinically, TTP can be distinguished by low (<10%) ADAMTS13 activity. The aim was to identify the differences in complement activation products between TTP and aHUS and investigate ADAMTS13 activity as a prognostic factor in aHUS. METHODS: We analyzed patients with thrombotic microangiopathy diagnosed as TTP (N=48) or aHUS (N=50), selected from a Korean registry (N=551). Complement activation products in the plasma samples collected from the patients prior to treatment and in 40 healthy controls were measured by ELISA. RESULTS: The levels of generalized (C3a), alternate (factor Bb), and terminal (C5a and C5b-9) markers were significantly higher (all P<0.01) in the patients than in the healthy controls. Only the factor Bb levels significantly differed (P=0.008) between the two disease groups. In aHUS patients, high normal ADAMTS13 activity (≥77%) was associated with improved treatment response (OR, 6.769; 95% CI, 1.605–28.542; P=0.005), remission (OR, 6.000; 95% CI, 1.693–21.262; P=0.004), exacerbation (OR, 0.242; 95% CI, 0.064–0.916; P=0.031), and disease-associated mortality rates (OR, 0.155; 95% CI, 0.029–0.813; P=0.017). CONCLUSION: These data suggest that complement biomarkers, except factor Bb, are similarly activated in TTP and aHUS patients, and ADAMTS13 activity can predict the treatment response and outcome in aHUS patients.
Atypical Hemolytic Uremic Syndrome ; Biomarkers ; Complement Activation ; Complement System Proteins ; Enzyme-Linked Immunosorbent Assay ; Humans ; Mortality ; Plasma ; Purpura, Thrombotic Thrombocytopenic ; Thrombotic Microangiopathies

Atypical hemolytic uremic syndrome (aHUS), a rare form of thrombotic microangiopathy, is distinguished from the typical form by the absence of a preceding verotoxin-producing Escherichia coli infection. Notably, aHUS occurs in association with genetic or acquired disorders causing dysregulation of the alternative complement pathway. Patients with aHUS may show the presence of anti-complement factor H (CFH) autoantibodies. This acquired form of aHUS (anti-CFH-aHUS) primarily affects children aged 9–13 years. We report a case of a 13-year-old Lao girl with clinical features of aHUS (most likely anti-CFH-aHUS). The initial presentation of the patient met the classical clinical triad of thrombotic microangiopathy (microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury) without preceding diarrheal illness. Low serum levels of complement 3 and normal levels of complement 4 indicated abnormal activation of the alternative complement pathway. Plasma infusion and high-dose corticosteroid therapy resulted in improvement of the renal function and hematological profile, although the patient subsequently died of infectious complications. This is the first case report that describes aHUS (possibly anti-CFH-aHUS) in Laos.
Adolescent ; Anemia, Hemolytic ; Atypical Hemolytic Uremic Syndrome ; Autoantibodies ; Child ; Complement C3 ; Complement C4 ; Complement Factor H ; Complement Pathway, Alternative ; Female ; Humans ; Immunosuppression ; Kidney ; Laos ; Plasma ; Shiga-Toxigenic Escherichia coli ; Thrombocytopenia ; Thrombotic Microangiopathies

C3 glomerulopathy is a renal disorder involving dysregulation of alternative pathway complement activation. In most instances, a membranoproliferative pattern of glomerular injury with a prevalence of C3 deposition is observed by immunofluorescence microscopy. Dense deposit disease (DDD) and C3 glomerulonephritis (C3GN) are subclasses of C3 glomerulopathy that are distinguishable by electron microscopy. Highly electron-dense transformation of glomerular basement membrane is characteristic of DDD. C3GN should be differentiated from post-infectious glomerulonephritis and other immune complex-mediated glomerulonephritides showing C3 deposits.
Complement Activation ; Complement Pathway, Alternative ; Dichlorodiphenyldichloroethane ; Glomerular Basement Membrane ; Glomerulonephritis ; Glomerulonephritis, Membranoproliferative ; Microscopy, Electron ; Microscopy, Fluorescence ; Pathology ; Prevalence

Ehlers-Danlos syndrome (EDS) VIII is an autosomal dominant inherited connective tissue disorder characterized by intractable periodontal inflammation, absence of gingiva, pretibial plaques, skin hyperextensibility, joint hypermobility, and tissue fragility with onset in the childhood or adolescence. In a recent report, heterozygous variants of the C1R or C1S related to the classical complement pathway were identified in families with history of EDS VIII. The current report describes a Korean 34-year-old female carrying a novel missense variant of C1R c.925T>G (p.Cys309Gly) and exhibiting early severe periodontitis, skin fragility, and joint hypermobility. The patient also had frontal, parietal, and temporal white matter brain lesions without definite vascular abnormalities on brain magnetic resonance imaging, which have not been surveyed meticulously in EDS VIII. Considering the genetic alteration of classic complement pathways in this condition, it is necessary to carefully observe multisystemic inflammation processes such as changes in brain white matter.
Adolescent ; Adult ; Brain ; Complement C1r ; Complement Pathway, Classical ; Complement System Proteins ; Connective Tissue ; Ehlers-Danlos Syndrome ; Female ; Gingiva ; Humans ; Inflammation ; Joint Instability ; Magnetic Resonance Imaging ; Periodontitis ; Rabeprazole ; Skin ; White Matter

Glial cells are receiving much attention since they have been recognized as important regulators of many aspects of brain function and disease. Recent evidence has revealed that two different glial cells, astrocytes and microglia, control synapse elimination under normal and pathological conditions via phagocytosis. Astrocytes use the MEGF10 and MERTK phagocytic pathways, and microglia use the classical complement pathway to recognize and eliminate unwanted synapses. Notably, glial phagocytosis also contributes to the clearance of disease-specific protein aggregates, such as β-amyloid, huntingtin, and α-synuclein. Here we reivew recent findings showing that glial cells are active regulators in brain functions through phagocytosis and that changes in glial phagocytosis contribute to the pathogenesis of various neurodegenerative diseases. A better understanding of the cellular and molecular mechanisms of glial phagocytosis in healthy and diseased brains will greatly improve our current approach in treating these diseases.
Astrocytes ; Brain* ; Complement Pathway, Classical ; Microglia ; Neurodegenerative Diseases ; Neuroglia* ; Phagocytosis ; Protein Aggregates ; Synapses

The complement system is an innate immune defense machinery comprising components that deploy rapid immune responses and provide efficient protection against foreign invaders and unwanted host elements. The complement system is activated upon recognition of pathogenic microorganisms or altered self-cells by exclusive pattern recognition molecules (PRMs), such as collectins, ficolins and pentraxins. Recent accumulating evidence shows that the different classes of effector PRMs build up a co-operative network and exert synergistic effects on complement activation. In this review, we describe our updated view of the crosstalk between previously unlinked PRMs in complement activation and the potential pathogenic effects during infection and inflammation.
Collectins ; Complement Activation* ; Complement System Proteins* ; Inflammation

C3 glomerulopathy (C3G) is a recently defined pathological entity characterized by C3 accumulation with absent or scant immunoglobulin deposition, leading to variable glomerular inflammation. The clinical presentation of patients with C3G is highly variable, as they may present with symptoms ranging from microscopic or mild proteinuria to full-blown nephrotic syndrome, with or without renal impairment. However, there is no consensus recommendation for specific treatment in children with C3G. Recently, new therapies have been suggested to target complement pathways, owing to an improvement in the understanding of the pathogenesis of C3G. C3G complement blockade with eculizumab, a monoclonal antibody targeted against complement C5, inhibits activation of the alternative complement pathway. We could not use eculizumab owing to its high price; thus, we administered oral prednisolone and mycophenolate mofetil (MMF). MMF was replaced with cyclosporine because proteinuria persisted, with a consistently low serum C3 level; we tapered off the prednisolone because of a Cushingoid appearance and amenorrhea. Thereafter, proteinuria improved, and the serum C3 level returned to normal. Thus, we report the effectiveness of cyclosporine in a patient with C3G and an inadequate response to prednisolone and MMF, who was detected via school urinary screening.
Amenorrhea ; Child* ; Complement C5 ; Complement Pathway, Alternative ; Complement System Proteins ; Consensus ; Cyclosporine* ; Female* ; Humans ; Immunoglobulins ; Inflammation ; Mass Screening ; Nephrotic Syndrome ; Prednisolone ; Proteinuria