• Asian-Australasian Journal of Animal Sciences
• /
• 제28권9호
• /
• pp.1354-1361
• /
• 2015

The complement system is a part of the natural immune regulation mechanism against invading pathogens. Complement activation from three different pathways (classical, lectin, and alternative) leads to the formation of C5-convertase, an enzyme for cleavage of C5 into C5a and C5b, followed by C6, C7, C8, and C9 in membrane attack complex. The C9 is the last complement component of the terminal lytic pathway, which plays an important role in lysis of the target cells depending on its self-polymerization to form transmembrane channels. To address the association of C9 with traits related to disease resistance, the complete porcine C9 cDNA was comparatively sequenced to detect single nucleotide polymorphisms (SNPs) in pigs of the breeds Hampshire (HS), Duroc (DU), Berlin miniature pig (BMP), German Landrace (LR), Pietrain (PIE), and Muong Khuong (Vietnamese potbelly pig). Genotyping was performed in 417 $F_2$ animals of a resource population (DUMI: $DU{\times}BMP$) that were vaccinated with Mycoplasma hyopneumoniae, Aujeszky diseases virus and porcine respiratory and reproductive syndrome virus at 6, 14 and 16 weeks of age, respectively. Two SNPs were detected within the third exon. One of them has an amino acid substitution. The European porcine breeds (LR and PIE) show higher allele frequency of these SNPs than Vietnamese porcine breed (MK). Association of the substitution SNP with hemolytic complement activity indicated statistically significant differences between genotypes in the classical pathway but not in the alternative pathway. The interactions between eight time points of measurement of complement activity before and after vaccinations and genotypes were significantly different. The difference in hemolytic complement activity in the both pathways depends on genotype, kind of vaccine, age and the interaction to the other complement components. These results promote the porcine C9 (pC9) as a candidate gene to improve general animal health in the future.

• The Korean Journal of Pain
• /
• 제37권2호
• /
• pp.91-106
• /
• 2024

The mechanisms of the chronic pain and depression comorbidity have gained significant attention in recent years. The complement system, widely involved in central nervous system diseases and mediating non-specific immune mechanisms in the body, remains incompletely understood in its involvement in the comorbidity mechanisms of chronic pain and depression. This review aims to consolidate the findings from recent studies on the complement system in chronic pain and depression, proposing that it may serve as a promising shared therapeutic target for both conditions. Complement proteins C1q, C3, C5, as well as their cleavage products C3a and C5a, along with the associated receptors C3aR, CR3, and C5aR, are believed to have significant implications in the comorbid mechanism. The primary potential mechanisms encompass the involvement of the complement cascade C1q/C3-CR3 in the activation of microglia and synaptic pruning in the amygdala and hippocampus, the role of complement cascade C3/C3a-C3aR in the interaction between astrocytes and microglia, leading to synaptic pruning, and the C3a-C3aR axis and C5a-C5aR axis to trigger inflammation within the central nervous system. We focus on studies on the role of the complement system in the comorbid mechanisms of chronic pain and depression.

• Macromolecular Research
• /
• 제12권1호
• /
• pp.46-52
• /
• 2004

In a continuation of our previous studies on blood compatibility profiles of anion-substituted poly(vinyl alcohol) (PVA) membranes, in which hydroxyl groups have been replaced with carboxymethyl (C-PVA) and sulfonyl groups (S-PVA), we have studied the activation of complement components and the changes in white cell and platelet count in vitro and compared them with those of unmodified PVA, Cuprophane, and low-density polyethylene. Complement activation of fluid phase components, C3a, Bb, iC3b, and SC5b-9, and of bound phases, C3c, C3d, and SC5b-9, were assessed by enzyme-linked immunosorbent assay (ELISA) and immunoblot, respectively. The changes in the number of white cells and platelets following complement activation were counted using a Coulter counter. C-PVA and S-PVA activated C3 to a lesser extent than did PVA, which we attribute to the diminished level of surface nucleophiles of the samples. In addition, C- and S-PVA exhibit increased inhibition of Bb production, resulting in a decrease in the extent of C5 activation. Consequently, because of the reduced activation of C3 and C5, C- and S-PVA samples cause marked decreases in the SC5b-9 levels in plasma. We also found that the negatively charged sulfonate and carboxylate groups of the samples cause a greater extent of adsorbtion of the positively charged anaphylatoxins, C3a and C5a, because of strong electrostatic attraction, which in turn provides an inhibition of chemotaxis and activation of leukocytes. The ability to inhibit complement production, together with the binding ability of anaphylatoxins of the C- and S-PVA samples, leads to a prominent decrease in lysis of leukocytes as well as activation of platelets.

• Childhood Kidney Diseases
• /
• 제26권1호
• /
• pp.58-62
• /
• 2022

Atypical hemolytic uremic syndrome (aHUS) is a rare disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury without any association with preceding diarrhea. Dysregulation of the complement system is the most common cause of aHUS, and monoclonal humanized anti-C5 antibodies are now recommended as the first-line treatment for aHUS. However, if the complement pathway is not the cause of aHUS, C5 inhibitors are ineffective. In this study, we report the second reported case of aHUS caused by DGKE mutations in Republic of Korea. The patient was an 11-month-old infant who presented with prodromal diarrhea similar to typical HUS, self-remitted with conservative management unlike complement-mediated aHUS but recurred with fever. While infantile aHUS often implies genetic dysregulation of the complement system, other rare genetic causes, such as DGKE mutation, need to be considered before deciding long-term treatment with C5 inhibitors.

• IMMUNE NETWORK
• /
• 제24권2호
• /
• pp.17.1-17.16
• /
• 2024

We have reported that anterior cruciate ligament (ACL) injury leads to the differential dysregulation of the complement system in the synovium as compared to meniscus tear (MT) and proposed this as a mechanism for a greater post-injury prevalence of post traumatic osteoarthritis (PTOA). To explore additional roles of complement proteins and regulators, we determined the presence of decay-accelerating factor (DAF), C5b, and membrane attack complexes (MACs, C5b-9) in discarded surgical synovial tissue (DSST) collected during arthroscopic ACL reconstructive surgery, MT-related meniscectomy, osteoarthritis (OA)-related knee replacement surgery and normal controls. Multiplexed immunohistochemistry was used to detect and quantify complement proteins. To explore the involvement of body mass index (BMI), after these 2 injuries, we examined correlations among DAF, C5b, MAC and BMI. Using these approaches, we found that synovial cells after ACL injury expressed a significantly lower level of DAF as compared to MT (p<0.049). In contrast, C5b staining synovial cells were significantly higher after ACL injury (p<0.0009) and in OA DSST (p<0.039) compared to MT. Interestingly, there were significantly positive correlations between DAF & C5b (r=0.75, p<0.018) and DAF & C5b (r=0.64 p<0.022) after ACL injury and MT, respectively. The data support that DAF, which should normally dampen C5b deposition due to its regulatory activities on C3/C5 convertases, does not appear to exhibit that function in inflamed synovia following either ACL injury or MT. Ineffective DAF regulation may be an additional mechanism by which relatively uncontrolled complement activation damages tissue in these injury states.

• 한국동물학회지
• /
• 제34권2호
• /
• pp.228-231
• /
• 1991

한국인 383명의 Compiement Component 6(C6)의 유전적 다형을 등전점 전기영동과 immunoblotting으로 조사하였다. 5가지 allotypes, C6 A, C6 B, C6 B2, C6 Ml, C6 M11이 나타났고, 이들의 대립유전인자 빈도는 C6*A=0.4399, C6*B=0.5144, C6*B2=0.0392로 산출되어 이는 동아시아인과 비슷하였다.

• IMMUNE NETWORK
• /
• 제21권5호
• /
• pp.36.1-36.16
• /
• 2021

Peroxiredoxins (Prxs) are ubiquitously expressed peroxidases that reduce hydrogen peroxide or alkyl peroxide production in cells. Prxs are released from cells in response to various stress conditions, and they function as damage-associated molecular pattern molecules. However, the secretory mechanism of Prxs and their roles have not been elucidated. Thus, we aimed to determine whether inflammasome activation is a secretory mechanism of Prxs and subsequently identify the effect of the secreted Prxs on activation of the classical complement pathway. Using J774A.1, a murine macrophage cell line, we demonstrated that NLRP3 inflammasome activation induces Prx1, Prx2, Prx5, and Prx6 secretion in a caspase-1 dependent manner. Using HEK293T cells with a transfection system, we revealed that the release of Prx1 and Prx2 relies on gasdermin-D (GSDMD)-mediated secretion. Next, we confirmed the binding of both Prx1 and Prx2 to C1q; however, only Prx2 could induce the C1q-mediated classical complement pathway activation. Collectively, our results suggest that inflammasome activation is a secretory mechanism of Prxs and that GSDMD is a mediator of their secretion. Moreover, secreted Prx1 and Prx2 bind with C1q, but only Prx2 mediates the classical complement pathway activation.

• Childhood Kidney Diseases
• /
• 제10권1호
• /
• pp.45-51
• /
• 2006

저자들은 C3의 감소와 육안적 혈뇨를 보인 환아에서 현미경적 혈뇨가 지속되면서 8주 후 시행한 검사에서도 C3의 감소가 지속되어 MPGN을 의심하고 신생검 예정이었다. 추적 관찰 중 수막구균 뇌수막염이 동반되었고, C3와 C5의 지속적인 감소와 C7과 C9의 일시적인 감소를 확인하였으며, 신생검에서 1형 MPGN으로 확인되었다. 본 증례의 아쉬운 점은 nephritic factor의 존재나 factor H의 결핍을 입증하여야 하나 아직까지 국내에서는 시행되지 않아 확인은 하지 못하였다. 앞으로 국내에서도 nephritic factor나 다양한 보체계(complement profile)에 대한 검사들이 시행되어야 할 것이다. 이제까지 국내에서는 후기 보체 결핍에 의하여 수막구균 뇌수막의 발생 증례 보고는 2004년 이후 여러 차례 있었지만, MPGN 환자에서 수막구균의 감염은 국내에 보고된 바가 없다. 본 증례를 통해 저보체혈증이 지속되는 일부의 MPGN 환자에서는 수막구균 감염 위험성이 존재하며, nephritic factor 검사와 함께 후기 보체 결핍에 대한 검사가 필요하다고 생각한다. 또한 수막구균성 뇌수막염에 이환된 모든 환자에 대해서 보체 검사를 시행하고 이런 환자에서 주기적인 소변 검사를 통하여 이상이 있을시 MPGN의 가능성을 고려하여 신생검을 고려하여야 할 것이다.

• Childhood Kidney Diseases
• /
• 제21권2호
• /
• pp.160-164
• /
• 2017

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.

• Clinical and Experimental Pediatrics
• /
• 제52권6호
• /
• pp.721-724
• /
• 2009

수막구균(Meningococcus) 질환은 보체계의 이상과 관련이 있을 수 있다. 보체 7번은 5개의 말단 보체 단백질(terminal complement protein) 중 하나로 이것이 결핍되면 보체의 세포를 용해하는 작용을 잃게 되어 반복적인 감염, 특히 수막구균 감염에 대한 감수성이 증가한다. 2003년 9월 고열, 하지 동통, 두통과 점상 출혈로 외래에 내원한 11세 된 여자 환자가 입원 후 급격히 혼수 상태로 빠졌으나 즉각적인 치료로 결국 완전히 회복되었다. 환자의 최종 진단은 수막구균성 패혈증과 관절염이었다. 환자의 오빠도 비슷한 세균성 뇌수막염 가족력이 있어 저자들은 보체계 검사와 유전자 돌연변이(gene mutation)에 대해 분석하였고, 환자와 환자의 오빠는 보체 7번 유전자의 exon 4에 G394C에 돌연변이가 있는 선천성 보체 7번 결핍 환자였고, 아빠는 보인자로 밝혀졌다. 저자들은 예방적으로 4가 수막구균 백신(tetravalent polysaccharide meningococcal vaccine, $Menomune^{(R)}$ A/C/Y/W-135, Aventis Pasteur, Canada)을 3년마다 접종하기로 하였고 2004년 10월에 처음으로 접종하였다. 그러나 2006년 9월 오빠는 급성 세균성 뇌수막염(meningoencephalitis)으로 사망하였다. 이에 저자들은 2년마다 예방적 접종을 하기로 하였고, 환자는 2008년 9월에 3번째로 접종하였으며 16세 된 환자는 현재까지 건강한 상태이다. 저자들은 수막구균 감염과 보체 7번 유전자 네번째 intron의 3' 말단 splice acceptor 위치에 G to T 돌연변이(g.IVS4-1G> T)가 있는 선천성 보체 7번 결핍을 가진 한국인 한 가족을 보고하는 바이다.