scholarly journals Association of Complement Factor D and H Polymorphisms with Recurrent Pregnancy Loss

2019 ◽  
Vol 21 (1) ◽  
pp. 17
Author(s):  
Hee Young Cho ◽  
Han Sung Park ◽  
Eun Ju Ko ◽  
Chang Soo Ryu ◽  
Jung Oh Kim ◽  
...  
Keyword(s):  
Complement System ◽  
Pregnancy Loss ◽  
Recurrent Pregnancy Loss ◽  
Factor H ◽  
Age Related Macular Degeneration ◽  
Taqman Probe ◽  
Complement Factor ◽  
Genotype Combination ◽  
Age Related ◽  
The Complement System

Recurrent pregnancy loss (RPL) is defined as two or more consecutive pregnancy losses prior to 20 weeks of gestation, and the incidence of RPL is estimated at 1% of all pregnancies. While the etiologies of RPL are diverse, immune function is considered to be an important cause of RPL. In particular, the complement system is essential for stable development of the placenta and fetus. Moreover, complement factor D (CFD) and complement factor H (CFH) are important regulators of the complement system and are associated with diseases, such as age-related macular degeneration. Therefore, we investigated whether polymorphisms of CFD and CFH are associated with RPL in 412 women with RPL and 384 control women. Genotyping of three polymorphisms (CFD rs2230216, CFH rs1065489, and CFH rs1061170) was performed by TaqMan probe real-time PCR and PCR-restriction fragment length polymorphism. Association of three polymorphisms with RPL was evaluated by statistical analysis. The GT/TC genotype combination of CFH rs1065489 G>T/CFH rs1061170 T>C was associated with a decreased risk of RPL occurrence compared with reference genotypes (adjusted odds ratio [AOR] = 0.439; 95% confidence interval [CI] = 0.238–0.810; p = 0.008), and this association remained significant after adjustment for multiple comparisons using false discovery rate (FDR) correction (p = 0.040). In addition, the CFH rs1065489G>T polymorphism is associated with homocysteine and prolactin level and CFH rs1061170 TC genotype is related to uric acid and triglycerides level in RPL patients. Therefore, those factors could be possible clinical risk factors in RPL patients.

scholarly journals Functional expression of complement factor I following AAV-mediated gene delivery in the retina of mice and human cells

Gene Therapy ◽  
2021 ◽  
Author(s):  
Anna K. Dreismann ◽  
Michelle E. McClements ◽  
Alun R. Barnard ◽  
Elise Orhan ◽  
Jane P. Hughes ◽  
...  
Keyword(s):  
Complement System ◽  
Functional Expression ◽  
Geographic Atrophy ◽  
Age Related Macular Degeneration ◽  
Complement Factor ◽  
Factor I ◽  
Complement Factor I ◽  
Age Related ◽  
The Complement System

AbstractDry age-related macular degeneration (AMD) is characterised by loss of central vision and currently has no approved medical treatment. Dysregulation of the complement system is thought to play an important role in disease pathology and supplementation of Complement Factor I (CFI), a key regulator of the complement system, has the potential to provide a treatment option for AMD. In this study, we demonstrate the generation of AAV constructs carrying the human CFI sequence and expression of CFI in cell lines and in the retina of C57BL/6 J mice. Four codon optimised constructs were compared to the most common human CFI sequence. All constructs expressed CFI protein; however, most codon optimised sequences resulted in significantly reduced CFI secretion compared to the non-optimised CFI sequence. In vivo expression analysis showed that CFI was predominantly expressed in the RPE and photoreceptors. Secreted protein in vitreous humour was demonstrated to be functionally active. The findings presented here have led to the formulation of an AAV-vectored gene therapy product currently being tested in a first-in-human clinical trial in subjects with geographic atrophy secondary to dry AMD (NCT03846193).

scholarly journals Semi-Quantitative Multiplex Profiling of the Complement System Identifies Associations of Complement Proteins with Genetic Variants and Metabolites in Age-Related Macular Degeneration

2021 ◽  
Vol 11 (12) ◽  
pp. 1256
Author(s):  
I. Erkin Acar ◽  
Esther Willems ◽  
Eveline Kersten ◽  
Jenneke Keizer-Garritsen ◽  
Else Kragt ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Complement System ◽  
Genetic Variants ◽  
Factor H ◽  
Age Related Macular Degeneration ◽  
Complement Protein ◽  
Complement Proteins ◽  
New Associations ◽  
Age Related ◽  
The Complement System

Age-related macular degeneration (AMD) is a major cause of vision loss among the elderly in the Western world. The complement system has been identified as one of the main AMD disease pathways. We performed a comprehensive expression analysis of 32 complement proteins in plasma samples of 255 AMD patients and 221 control individuals using mass spectrometry-based semi-quantitative multiplex profiling. We detected significant associations of complement protein levels with age, sex and body-mass index (BMI), and potential associations of C-reactive protein, factor H related-2 (FHR-2) and collectin-11 with AMD. In addition, we confirmed previously described associations and identified new associations of AMD variants with complement levels. New associations include increased C4 levels for rs181705462 at the C2/CFB locus, decreased vitronectin (VTN) levels for rs11080055 at the TMEM97/VTN locus and decreased factor I levels for rs10033900 at the CFI locus. Finally, we detected significant associations between AMD-associated metabolites and complement proteins in plasma. The most significant complement-metabolite associations included increased high density lipoprotein (HDL) subparticle levels with decreased C3, factor H (FH) and VTN levels. The results of our study indicate that demographic factors, genetic variants and circulating metabolites are associated with complement protein components. We suggest that these factors should be considered to design personalized treatment approaches and to increase the success of clinical trials targeting the complement system.

scholarly journals CFH Loss in Human RPE Cells Leads to Inflammation and Complement System Dysregulation via the NF-κB Pathway

2021 ◽  
Vol 22 (16) ◽  
pp. 8727
Author(s):  
Angela Armento ◽  
Tiziana L. Schmidt ◽  
Inga Sonntag ◽  
David A. Merle ◽  
Mohamed Ali Jarboui ◽  
...  
Keyword(s):  
Complement System ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Factor H ◽  
Age Related Macular Degeneration ◽  
Complement Factor ◽  
Major Pathway ◽  
Rpe Cells ◽  
Age Related

Age-related macular degeneration (AMD), the leading cause of vision loss in the elderly, is a degenerative disease of the macula, where retinal pigment epithelium (RPE) cells are damaged in the early stages of the disease, and chronic inflammatory processes may be involved. Besides aging and lifestyle factors as drivers of AMD, a strong genetic association to AMD is found in genes of the complement system, with a single polymorphism in the complement factor H gene (CFH), accounting for the majority of AMD risk. However, the exact mechanism of CFH dysregulation confers such a great risk for AMD and its role in RPE cell homeostasis is unclear. To explore the role of endogenous CFH locally in RPE cells, we silenced CFH in human hTERT-RPE1 cells. We demonstrate that endogenously expressed CFH in RPE cells modulates inflammatory cytokine production and complement regulation, independent of external complement sources, or stressors. We show that loss of the factor H protein (FH) results in increased levels of inflammatory mediators (e.g., IL-6, IL-8, GM-CSF) and altered levels of complement proteins (e.g., C3, CFB upregulation, and C5 downregulation) that are known to play a role in AMD. Moreover, our results identify the NF-κB pathway as the major pathway involved in regulating these inflammatory and complement factors. Our findings suggest that in RPE cells, FH and the NF-κB pathway work in synergy to maintain inflammatory and complement balance, and in case either one of them is dysregulated, the RPE microenvironment changes towards a proinflammatory AMD-like phenotype.

scholarly journals The role of complement system and other inflammatory factors in the development of age-related macular degeneration

2018 ◽  
Vol 99 (4) ◽  
pp. 657-664
Author(s):  
E A Abdulaeva
Keyword(s):  
Macular Degeneration ◽  
Complement System ◽  
Genetic Factors ◽  
Alternative Pathway ◽  
Factor H ◽  
Age Related Macular Degeneration ◽  
Inflammatory Factors ◽  
Complement Factor ◽  
Age Related

The article is a review of literature on the role of complement system and inflammatory factors in the development of age-related macular degeneration. The review uses materials of domestic and foreign researchers. The clinical characteristics of age-related macular degeneration are presented, the role of genetic factors, complement factors, biomarkers of inflammation and alternative pathway of complement activation in the pathogenesis and risk of age-related macular degeneration is determined. Age-related macular degeneration is a chronic progressive multifactorial disease that affects macular area of the retina and is the main cause of loss of central vision in patients of older age group. The most important genetic factors are chromosome 1 (1q32) including complement factor H and complement factor H related genes and chromosome 10 (10q31). Variants associated with a moderate effect on developmental risk were identified in C3, complement factor I and complement factor B genes. In the pathogenesis of age-related macular degeneration, the key role is played by the damaged regulation of the alternative complement pathway. Single nucleotide polymorphisms in complement genes that affect the risk of development of age-related macular degeneration are predominantly involved in the alternative pathway of activation of the complement system. In pathomorphological studies, the initial localization of the pathological process of this pathology was established to be a complex of retinal pigment epithelium, Bruch’s membrane, and choriocapillaries followed by loss of photoreceptor function. The review of studies of systemic inflammatory biomarkers, cytokines, vascular endothelial growth factors in peripheral blood, blood serum, aqueous humour at various stages and forms of age-related macular degeneration is presented.

scholarly journals Associations of the intestinal microbiome with the complement system in age-related macular degeneration

2019 ◽  
Author(s):  
Denise Corinne Zysset-Burri ◽  
Irene Keller ◽  
Lieselotte E. Berger ◽  
Carlo R. Largiadèr ◽  
Matthias Wittwer ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Complement System ◽  
Age Related Macular Degeneration ◽  
Classification Model ◽  
Intestinal Microbiome ◽  
Complement Factor ◽  
Age Related ◽  
Potential Biomarker ◽  
The Complement System ◽  
Deficient Mice

Abstract Background: Age-related macular degeneration (AMD) is a leading cause of severe vision loss in the aged population. The etiology of AMD is multifactorial and includes nutritional factors, genetic variants mainly in the complement pathway, environmental risk factors and alterations in the intestinal microbiome. However, it remains largely unexplored whether there is an interdependency of these factors leading to the development of AMD. To investigate this issue, a comprehensive shotgun metagenomics analysis of 57 AMD and 58 healthy controls as well as of 16 complement C3 deficient mice and 16 wildtypes was performed. Single nucleotide polymorphisms (SNPs) in the complement factors were assessed with pre-designed TaqMan® SNP genotyping assays. Results: The composition of the intestinal microbiome differed significantly between AMD patients and controls. Whereas the class Negativicutes was more abundant in patients, the genus Oscillibacter and Bacteroides species had a significantly higher prevalence in persons without AMD. While SNPs within the complement factor B gene were more abundant in controls, SNPs within the high temperature requirement A serine peptidase 1 and complement factor H (CFH) genes were associated with AMD. Using a classification model, Negativicutes was identified as a potential biomarker for AMD and furthermore, it positively correlated with CFH. In addition, similar taxonomic features were identified that distinguished wildtype mice from C3 deficient mice. Conclusion: The composition of the intestinal microbiome differs between AMD patients and controls as well as between C3 deficient mice and wildtype mice. Moreover, since the phylum Firmicutes has been identified as potential biomarker for AMD and positively correlates with the genetic risk factor CFH, the study suggests an association between the intestinal microbiome and the complement system in AMD.

scholarly journals CFH loss in human RPE cells leads to inflammation and complement system dysregulation via the NF-ƙB pathway

2021 ◽  
Author(s):  
Angela Armento ◽  
Tiziana Luisa Schmidt ◽  
Inga Sonntag ◽  
David Merle ◽  
Mohamed-ali Jarboui ◽  
...  
Keyword(s):  
Complement System ◽  
Vision Loss ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Factor H ◽  
Age Related Macular Degeneration ◽  
Complement Factor ◽  
Major Pathway ◽  
Rpe Cells ◽  
Age Related

Age-related macular degeneration (AMD), the leading cause of vision loss in the elderly, is a degenerative disease of the macula, where retinal pigment epithelium (RPE) cells are damaged in the early stages of the disease and chronic inflammatory processes may be involved. Besides ageing and lifestyle factors as drivers of AMD, a strong genetic association to AMD is found in genes of the complement system, with a single polymorphism in the complement factor H gene (CFH), accounting for the majority of AMD risk. However, the exact mechanism by which CFH dysregulation confers such a great risk for AMD and its role in RPE cells homeostasis is unclear. To explore the role of endogenous CFH locally in RPE cells, we silenced CFH in human hTERT-RPE1 cells. We demonstrate that endogenously expressed CFH in RPE cells modulates inflammatory cytokine production and complement regulation, independent of external complement sources or stressors. We show that loss of the factor H protein (FH) results in increased levels of inflammatory mediators (e.g. IL-6, IL-8, GM-CSF) and altered levels of complement proteins (e.g. C3, CFB upregulation and C5 downregulation) that are known to play a role in AMD. Moreover, we identified the NF-ƙB pathway as the major pathway involved in the regulation of these inflammatory and complement factors. Our findings suggest that in RPE cells, FH and the NF-ƙB pathway work in synergy to maintain inflammatory and complement balance and in case either one of them is dysregulated, the RPE microenvironment changes towards a pro-inflammatory AMD-like phenotype.

scholarly journals Unravelling the effect of a potentiating anti-Factor H antibody on atypical hemolytic uremic syndrome associated factor H variants

2020 ◽  
Author(s):  
Gillian Dekkers ◽  
Mieke Brouwer ◽  
Jorn Jeremiasse ◽  
Angela Kamp ◽  
Robyn M. Biggs ◽  
...  
Keyword(s):  
Hemolytic Uremic Syndrome ◽  
Complement System ◽  
Alternative Pathway ◽  
Atypical Hemolytic Uremic Syndrome ◽  
Factor H ◽  
Age Related Macular Degeneration ◽  
Regulatory Function ◽  
Age Related ◽  
Uremic Syndrome ◽  
The Complement System

AbstractThe complement system plays an important role in our innate immune system. Complement activation results in clearance of pathogens, immune complex and apoptotic cells. The host is protected from complement-mediated damage by several complement regulators. Factor H (FH) is the most important fluid-phase regulator of the alternative pathway of the complement system. Heterozygous mutations in FH are associated with complement-related diseases such as atypical hemolytic uremic syndrome (aHUS) and age-related macular degeneration.We recently described an agonistic anti-FH monoclonal antibody that can potentiate the regulatory function of FH. This antibody could serve as a potential new drug for aHUS patients and alternative to C5 blockade by Eculizumab. However, it is unclear whether this antibody can potentiate FH mutant variants in addition to wild type FH. Here, the functionality and potential of the agonistic antibody in the context of pathogenic aHUS-related FH mutant proteins was investigated. The binding affinity of recombinant WT FH, and the FH variants, W1183L, V1197A, R1210C, and G1194D to C3b was increased upon addition of the potentiating antibody and similarly, the decay accelerating activity of all mutants is increased. The potentiating anti-FH antibody is able to restore the surface regulatory function of most of the tested FH mutants to WT FH levels. In conclusion, our potentiating anti-FH is broadly active and able to enhance both WT FH function as well as most aHUS-associated FH variants tested in this study.

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