C3a Levels Research Articles

Activation of platelets and the complement system in mice with Schistosoma-induced pulmonary hypertension.

Schistosomiasis-induced pulmonary hypertension (PH) presents a significant global health burden, yet the underlying mechanisms remain poorly understood. Here, we investigate the involvement of platelets and the complement system in the initiation events leading to Schistosoma-induced PH. We demonstrate that Schistosoma exposure leads to thrombocytopenia, platelet accumulation in the lung, and platelet activation. In addition, we observed increased plasma complement anaphylatoxins C3a and C5a, indicative of complement system activation, and elevated platelet expression of C1q, C3, decay activating factor (DAF), and complement C3a and C5a receptors. Our findings suggest the active involvement of platelets in responding to complement system signals induced by Schistosoma exposure and form the basis for future mechanistic studies on how complement may regulate platelet activation and promote the development of Schistosoma-induced PH.NEW & NOTEWORTHY Schistosomiasis-induced pulmonary hypertension (PH) is a significant global health burden, yet the underlying mechanisms remain poorly understood. We demonstrate that Schistosoma exposure leads to platelet accumulation in the lung and platelet activation. We observed increased plasma levels of C3a and C5a, indicative of complement system activation, and elevated expression of platelet complement proteins and receptors. These findings underscore the role of platelets and complement in the inflammatory responses associated with Schistosoma-induced PH.

Dynamic features of the humoral immunity in patients with acute coronary syndrome depending on the content of B lymphocytes with the CD3<sup>-</sup>CD19<sup>+</sup>CD5<sup>+</sup> phenotype, who have and have not COVID-19

The purpose of the work was to study the dynamic features of the humoral immunity in patients with acute coronary syndrome depending on the content of B lymphocytes with the CD3-CD19+CD5+ phenotype, who had and did not have COVID-19. We analyzed data on humoral immunity in men aged 40 to 65 years with acute coronary syndrome, who had and did not have COVID-19, depending on the content of B lymphocytes with the CD3-CD19+CD5+ phenotype. All patients underwent coronary angiography with further stenting of the coronary arteries. The values of lymphocytes with the CD45+CD3-CD19+ phenotype and the presence or absence of COVID-19 previously were taken into account. Using the flow cytometry method, 2 groups were gated using the pan-leukocyte marker CD45+: the subgroup of B lymphocytes CD3-CD19+CD5+ and the subgroup of B lymphocytes CD3-CD19+CD5-, B lymphocytes (CD45+CD3-CD19+). Levels of total IgA, IgG, IgM, C1-inhibitor, C3a and C5a complement components by enzyme immunoassay. After coronary artery stenting, B lymphocytes (CD3-CD19+CD5+) significantly increased in the group of people with COVID-19, with initially low levels of these cells (p 0.01) and normal cells (p 0.05). In individuals who had COVID-19 and did not have this disease, with initially decreased CD3-CD19+CD5+ cells, B lymphocytes (CD45) increased significantly (p 0.001 and p 0.05, respectively) over time (p 0.05+CD3-CD19+), B lymphocytes (CD3-CD19+CD5-). In the group of patients who recovered from COVID-19 with normal CD3-CD19+CD5+ cells, the relative number of B-lymphocytes decreased over time (p 0.01) (CD45+CD3-CD19+) and CD3-CD19+CD5- cells. In persons who had previously suffered from COVID-19, with increased CD3-CD19+CD5+ cells, the number of B-lymphocytes (CD45+) significantly (p 0.05) decreased over time CD3-CD19+), in those who did not have COVID-19 with high above-mentioned cells, immunoglobulin A significantly (p 0.05) increased. The most severe clinically was the group of people with low CD3-CD19+CD5+B cells and COVID-19 in the anamnesis.

Complement C3a/C3aR inhibition alleviates the formation of aortic aneurysm in Marfan syndrome mice

Mutations in fibrillin 1 (FBN1) is the main cause of Marfan syndrome (MFS) with thoracic aortic aneurysm (TAA) as the main complication. Activation of the complement system plays a key role in the formation of thoracic and abdominal aortic aneurysms. However, the role of the complement system in MFS-associated aortic aneurysms remains unclear. In this study, we observed increased levels of complement C3a and C5a in the plasma of MFS patients and mouse, and the increased deposition of the activated complement system product C3b/iC3b was also observed in the elastic fiber rupture zone of 3-month-old MFS mice. The expression of C3a receptor (C3aR) was increased in MFS aortas, and recombinant C3a promoted the expression of cytokines in macrophages. The administration of a C3aR antagonist (C3aRA) attenuated the development of thoracic aortic aneurysms in MFS mice. The increased inflammation response and matrix metalloproteinases activities were also attenuated by C3aRA treatment in MFS mice. Therefore, these findings indicate that the complement C3a/C3aR inhibition alleviates the formation of aortic aneurysm in Marfan syndrome mice.

Erythropoietin Effect on Complement Activation in Chronic Kidney Disease.

The complement system is an important part of innate immunity. Despite its known protective role, the complement system may contribute to increased inflammation and tissue injury in cases where its balanced activation is disrupted. The kidneys have been shown to be largely affected by complement dysregulation. The aim of the present study was to investigate the effect of erythropoietin administration, on the complement system, in chronic kidney disease patients. The study involved 20 patients with CKD who received erythropoietin and measurements of levels of complement factors C3a and C5a and complement regulatory proteins (CregPs) CD55, CD46, and CD59. An increase in serum C3a and C5a levels was observed in response to EPO therapy. The increase in C3a was statistically significant (p < 0.05) and concurrent with a statistically significant decrease in CD55 in CD4+ T cells (p < 0.05) and B cells (p < 0.05) and CD59 levels in CD4+ and CD8+ T cells (p < 0.05) at completion of EPO therapy compared with healthy controls. The above observations demonstrate that EPO induces complement activation in patients undergoing EPO therapy with a simultaneous restriction of CRegPs expression, thus possibly allowing the uncontrolled complement activation, which may contribute to tissue injury and disease progression.

Decoding the genetic landscape of juvenile dermatomyositis: insights from phosphorylation-associated single nucleotide polymorphisms.

Genome-wide association studies (GWASs) have identified genetic susceptibility loci associated with juvenile dermatomyositis (JDM). Single nucleotide polymorphisms related to phosphorylation (phosSNPs) are critical nonsynonymous mutations exerting substantial influence on gene expression regulation. The aim of this study was to identify JDM susceptibility genes in the GWAS loci by the use of phosSNPs. We explored quantitative trait loci (QTLs) among the phosSNPs associated with JDM using data from eQTL (bulk tissues and single-cell) and pQTL studies. For gene expression and protein levels significantly influenced by JDM-associated phosSNPs, we assessed their associations with JDM through MR analyses. Additionally, we conducted differential expression gene analyses, incorporating single-cell transcriptomic profiling of 6 JDM cases and 11 juvenile controls (99,396 cells). We identified 31 phosSNPs situated in the 6p21 locus that were associated with JDM. Half of these phosSNPs showed effects on gene expression in various cells and circulating protein levels. In MR analyses, we established associations between the expression levels of pivotal JDM-associated genes, including MICB, C4A, HLA-DRB1, HLA-DRB5, and PSMB9, in skin, muscle, or blood cells and circulating levels of C4A, with JDM. Utilizing single-cell eQTL data, we identified a total of 276 association signals across 14 distinct immune cell types for 28 phosSNPs. Further insights were gained through single-cell differential expression analysis, revealing differential expression of PSMB9, HLA-A, HLA-B, HLA-C, HLA-DPB1, HLA-DQA1, HLA-DQB1, and HLA-DRB1 in immune cells. The present study pinpointed phosSNPs within susceptibility genes for JDM and unraveled the intricate relationships among these SNPs, gene expression levels, and JDM.

Complete Description of the Three Pathways of the Complement System in a Series of 430 Patients with Rheumatoid Arthritis.

The complement (C) system is implicated in the etiopathogenesis of rheumatoid arthritis (RA). However, there is a lack of studies characterizing all three C pathways in RA patients. This study aimed to evaluate the association between an in-depth examination of the C system and RA patient characteristics, focusing on disease activity and the presence of rheumatoid factor and anti-citrullinated protein autoantibodies (ACPA). In a cohort of 430 RA patients, functional assays of the three C pathways (classical, alternative, and lectin) and serum levels of their components were assessed. Components included C1q (classical); factor D and properdin (alternative); lectin (lectin); C1-inhibitor; C2, C4, and C4b (classical and lectin); C3, C3a, and C4b (common); and C5, C5a, and C9 (terminal). A multivariable linear regression analysis showed significant positive correlations between C-reactive protein and C system proteins and functional assays, especially in the terminal and common pathways. Disease activity, measured by scores with or without acute phase reactants, positively correlated with the classical pathway functional test and terminal pathway products. Conversely, rheumatoid factor or ACPA presence was associated with lower classical pathway values and decreased C3a and C4b levels, suggesting complement depletion. In conclusion, RA disease activity increases C molecules and functional complement assays, while rheumatoid factor or ACPA positivity is linked to C consumption. Our study offers a detailed analysis of the complement system's role in RA, potentially guiding the development of more targeted and effective treatment strategies.

TLR2 and TLR4 Are Expressed in Epiretinal Membranes: Possible Links with Vitreous Levels of Complement Fragments and DAMP-Related Proteins.

Previous studies reported the expression of toll-like receptors (TLRs), merely TLR2 and TLR4, and complement fragments (C3a, C5b9) in vitreoretinal disorders. Other than pathogens, TLRs can recognize endogenous products of tissue remodeling as damage-associated molecular pattern (DAMPs). The aim of this study was to confirm the expression of TLR2 and TLR4 in the fibrocellular membranes and vitreal fluids (soluble TLRs) of patients suffering of epiretinal membranes (ERMs) and assess their association with disease severity, complement fragments and inflammatory profiles. Twenty (n = 20) ERMs and twelve (n = 12) vitreous samples were collected at the time of the vitrectomy. Different severity-staged ERMs were processed for: immunolocalization (IF), transcriptomic (RT-PCR) and proteomics (ELISA, IP/WB, Protein Chip Array) analysis. The investigation of targets included TLR2, TLR4, C3a, C5b9, a few selected inflammatory biomarkers (Eotaxin-2, Rantes, Vascular Endothelial Growth Factor (VEGFA), Vascular Endothelial Growth Factor receptor (VEGFR2), Interferon-γ (IFNγ), Interleukin (IL1β, IL12p40/p70)) and a restricted panel of matrix enzymes (Matrix metalloproteinases (MMPs)/Tissue Inhibitor of Metallo-Proteinases (TIMPs)). A reduced cellularity was observed as function of ERM severity. TLR2, TLR4 and myD88 transcripts/proteins were detected in membranes and decreased upon disease severity. The levels of soluble TLR2 and TLR4, as well as C3a, C5b9, Eotaxin-2, Rantes, VEGFA, VEGFR2, IFNγ, IL1β, IL12p40/p70, MMP7 and TIMP2 levels were changed in vitreal samples. Significant correlations were observed between TLRs and complement fragments and between TLRs and some inflammatory mediators. Our findings pointed at TLR2 and TLR4 over-expression at early stages of ERM formation, suggesting the participation of the local immune response in the severity of disease. These activations at the early-stage of ERM formation suggest a potential persistence of innate immune response in the early phases of fibrocellular membrane formation.

Astrocyte-secreted C3 signaling impairs neuronal development and cognition in autoimmune diseases

Neuromyelitis optica (NMO) arises from primary astrocytopathy induced by autoantibodies targeting the astroglial protein aquaporin 4 (AQP4), leading to severe neurological sequelae such as vision loss, motor deficits, and cognitive decline. Mounting evidence has shown that dysregulated activation of complement components contributes to NMO pathogenesis. Complement C3 deficiency has been shown to protect against hippocampal neurodegeneration and cognitive decline in neurodegenerative disorders (e.g., Alzheimer's disease, AD) and autoimmune diseases (e.g., multiple sclerosis, MS). However, whether inhibiting the C3 signaling can ameliorate cognitive dysfunctions in NMO remains unclear. In this study, we found that the levels of C3a, a split product of C3, significantly correlate with cognitive impairment in our patient cohort. In response to the stimulation of AQP4 autoantibodies, astrocytes were activated to secrete complement C3, which inhibited the development of cultured neuronal dendritic arborization. NMO mouse models exhibited reduced adult hippocampal newborn neuronal dendritic and spine development, as well as impaired learning and memory functions, which could be rescued by decreasing C3 levels in astrocytes. Mechanistically, we found that C3a engaged with C3aR to impair neuronal development by dampening β-catenin signalling. Additionally, inhibition of the C3-C3aR-GSK3β/β-catenin cascade restored neuronal development and ameliorated cognitive impairments. Collectively, our results suggest a pivotal role of the activation of the C3-C3aR network in neuronal development and cognition through mediating astrocyte and adult-born neuron communication, which represents a potential therapeutic target for autoimmune-related cognitive impairment diseases.

Serum proteomic analysis uncovers novel serum biomarkers for depression.

The identification of depression primarily relies on the clinical symptoms and psychiatric evaluation of the patient, in the absence of objective and quantifiable biomarkers within clinical settings. This study aimed to explore potential serum biomarkers associated with depression. Serum samples from a training group comprising 48 depression patients and 48 healthy controls underwent proteomic analysis. Magnetic bead-based weak cation exchange (MB-WCX) and MALDI-TOF-MS were used in combination. To screen the differential peaks, ClinProTools software was employed. The proteins were identified using LC-MS/MS. ELISA was employed to confirm the expression of entire protein in the serum of the verification cohort, which encompassed 48 individuals who had been diagnosed with Depression and 48 healthy controls who were collected prospectively. Subsequently, logistic regression analysis was conducted to determine the diagnostic efficacy of the aforementioned predictors. Five potential biomarker peaks indicating depression were identified in serum samples (peak 1, m/z: 1868.21; peak 2, m/z: 1062.35; peak 3, m/z: 1452.12; peak 4, m/z: 1208.72; peak 5, m/z: 1619.58). All of these peaks had higher expression in the pre-therapy group and were confirmed to be Tubulin beta chain (TUBB), Inter-alpha-trypsin inhibitor heavy chain H4 (ITIH4), Complement component 3 (C3), and Complement C4A precursor (C4A) by ELISA validation. Multivariate logistic regression analysis revealed that serum levels of TUBB, ITIH4, C3, and C4A were significant independent risk factors for the development of depression. Depression is a prevalent psychiatric condition. Timely detection is challenging, resulting in poor prognoses for patients. Our study on plasma proteomics for depression demonstrated that TUBB, ITIH4, C3, and C4A differentiate between depression patients and healthy controls. The proteins that were identified could potentially function as biomarkers for the diagnosis of depression. Pinpointing these biomarkers could enable early identification of depression, which would advance precise treatment.

Complement activation is associated with right ventricular dysfunction and the severity of pulmonary embolism: links with prothrombotic state.

Little is known about the role of complement activation in acute pulmonary embolism (PE). We investigated whether complement activation is associated with the severity of acute PE, along with the associated prothrombotic state, systemic inflammation and neutrophil extracellular traps (NETs) formation. We studied 109 normotensive, non-cancer PE patients (aged 58.1±15.0 years). On admission prior to initiation of anticoagulation, plasma soluble complement components, i.e., C3a and sC5b-9, were measured with enzyme-linked immunosorbent assay (ELISA), along with thrombin generation, fibrinolysis proteins (plasminogen, antiplasmin, plasminogen activator inhibitor-1), factor VIII (FVIII) activity, and fibrin clot properties, including clot permeability (Ks, a measure of clot density) and clot lysis time (CLT). Moreover, we determined inflammatory markers and citrullinated histone H3, a specific marker of NETs formation. Patients in the lower tertile of C3a (≤1.45 ng/mL, n=37) had lower simplified Pulmonary Embolism Severity Index (sPESI) values and were less likely to have right ventricular (RV) dysfunction compared to the remaining subjects. The former subgroup also had 13% lower FVIII activity, but not fibrinogen, interleukin-6, fibrinolysis proteins, and thrombin generation. Plasma C3a levels correlated inversely with Ks and positively with CLT indicating formation of denser and poorly lysable clots in subjects with elevated C3a. Despite a positive association between C3a and sC5b-9, the latter parameter was solely associated with higher FVIII, but not with other variables. We showed that in acute PE enhanced complement activation characterizes patients with poorer short-term prognosis who display prothrombotic fibrin clot properties and elevated FVIII, which supports the involvement of complement proteins in acute thromboembolism.

Sample processing time but not storage time affects complement activation markers C4a, C4d, C3a, iC3b, Bb, C5a, and sC5b-9 levels in EDTA-plasma of individuals at clinical high-risk for psychosis

The complement system is an important part of the innate immune system and plays a key role in inflammatory processes. Concentrations of complement activation fragments in plasma are markers of systemic activation and have been found to be altered in a wide range of diseases. Some plasma activation marker levels can be influenced by sample processing and storage time. We quantified seven complement activation markers (C4a, C4d, C3a, iC3b, Bb, C5a, and sC5b-9 (TCC)) in EDTA-plasma as part of a multi-centre clinical study analysing complement activation in individuals with clinical high-risk (CHR) for psychosis compared with healthy controls. Samples had been collected, processed, and subsequently stored at -80°C over a period of 9.5–13.6 years, according to a standard operating protocol (SOP). Complement activation markers were quantified using commercially available and standardised enzyme-linked immunosorbent assays (ELISA). In a post hoc analysis of variables affecting the analyses we investigated the impact of EDTA-to-freezer processing time (<1–7.35 hours) and freezer storage time (9.5–13.6 years). EDTA-to-freezer processing time moderately correlated positively with C4a, C3a, iC3b and sC5b-9 levels. Storage time at -80°C was not significantly correlated with any complement activation marker. This study provides valuable insight into the impact of sample processing and long-term sample storage in complement activation marker studies. The results suggest that storage time in -80°C is not a confounding factor affecting non-specific complement activation in EDTA-plasma. Sample-processing time does moderately affect the levels of some complement activation markers. This should be considered as a co-variate when analysing complement activation marker levels. Further, the impact may vary for healthy or clinical samples where immune activation is part of the pathology. These findings are important when planning large-scale clinical studies that include quantification of complement components and its activation fragments as biomarkers. It supports the collection of EDTA-plasma and fast sample processing to be included into a study standard operating procedure.

Clinical values of serum C5a in Alzheimer’s disease patients with different dementia stages

Alzheimer’s disease (AD) is characterized by abnormal inflammatory responses, and complement C5a (C5a) is known to initiate inflammation. This study aimed to investigate the associations between serum C5a, inflammatory responses, and cognitive function in AD patients. A total of 242 AD patients and 132 age-matched controls were included. Enzyme-linked immunosorbent assay revealed increased levels of C5a, interleukin (IL)-4, IL-6, IL-10, IL-1β, and tumor necrosis factor (TNF)-α with advancing stages of AD. Pearson correlation coefficient and receiver operating characteristic curve revealed positive correlations between serum C5a levels, inflammatory cytokine levels, Neuropsychiatric Inventory (NPI) and Activities of Daily Living (ADL) scores, and negative correlations with Mini-mental State Examination (MMSE) and Montreal cognitive assessment (MoCA) scores. Serum C5a above 68.68 pg/mL could aid in the diagnosis of AD. Multivariable logistic analysis revealed that serum C5a was an independent risk factor for IL-1β/IL-6/IL-10/TNF-α and an independent protective factor for IL-4. Higher serum C5a levels were associated with lower MMSE and MoCA scores. In conclusion, elevated serum C5a levels were beneficial for AD diagnosis and predictive of inflammation and cognitive dysfunction.

Enhancing prognostic prediction of invasive candidiasis among cancer patients with a serum C5a-based scoring model.

Invasive candidiasis poses a life-threatening risk, and early prognosis assessment is vital for timely interventions to reduce mortality. Serum C5a levels have recently been linked to prognosis, but confirmation in cancer patients is pending. We detected the concentrations of serum C5a in hospitalized cancer patients with invasive candidiasis from 2020 to 2023, and retrospectively analyzed the clinical data. 372 cases were included in this study, with a 90-day mortality rate of 21.8%. Candida albicans (48.7%) remained the predominant pathogen, followed by Candida glabrata (25.5%), Candida tropicalis (12.4%), and Candida parapsilosis (8.3%). Gastrointestinal cancer was the most diagnosed pathology type (37.6%). Serum C5a demonstrated a noteworthy correlation with 90-day mortality, and employing a cutoff value of 36.7ng/ml revealed significantly higher 90-day mortality in low-C5a patients (41.2%) compared to high-C5a patients (6.3%) (p < 0.001). We also identified no source control, no surgery, metastasis, or chronic renal failure independently correlated with the 90-day mortality. Based on this, a prognostic model combining C5a and clinical parameters was constructed, which performed better than models built solely on C5a or clinical parameters. Furthermore, we weighted scores to each parameter in the model and presented diagnostic sensitivity and specificity corresponding to different score points calculated by the model. We constructed a prognostic scoring model including serum C5a and clinical parameters, which would contribute to precise prognosis assessment and benefit the outcome among cancer patients.

Inflammation and tissue remodeling mediator expression during gingivitis: A comparison between experimental, naturally occurring gingivitis, and periodontal health.

The aim of this study is to evaluate the immune regulation and tissue remodeling responses during experimental gingivitis (EG) and naturally occurring gingivitis (NG) to provide a comprehensive analysis of host responses. Gingival crevicular fluid (GCF) was obtained from 2 human studies conducted in university settings. The EG study enrolling 26 volunteers provided controls for the baseline (Day 0) from healthy disease-free participants, while Day 21 (the end of EG induction of the same group) was used to represent EG. Twenty-six NG participants age-matched with those of the EG group were recruited. GCF samples were analyzed for 39 mediators of inflammatory/immune responses and tissue remodeling using commercially available bead-based multiplex immunoassays. The differences in GI and mediator expression among groups were determined at a 95% confidence level (p ≤ 0.05) by a 2-way analysis of variance (ANOVA) with a post-hoc Tukey's test. Our findings showed that EG had a greater gingival index than NG and was healthy (p<0.01 of all comparisons). Furthermore, EG showed significantly higher levels of MPO (p<0.001), CCL3 (p<0.05), and IL-1B (p<0.001) than NG. In contrast, NG had increased levels of MIF (p<0.05), Fractalkine (p<0.001), angiogenin (p<0.05), C3a (p<0.001), BMP-2 (p<0.001), OPN (p<0.05), RANKL (p<0.001), and MMP-13 (p<0.001) than EG. Consistent with the findings from chronic (NG) versus acute (EG) inflammatory lesions, these data reveal that NG displays greater immune regulation, angiogenesis, and bone remodeling compared to EG.

Abstract PO5-25-05: Crosstalk between adipocyte and tumor cells with ESR1 mutations via adipsin enhances tumor growth

Abstract While endocrine therapies have shown clinical benefits for breast cancer with ESR1 mutations, resistance development is a significant challenge. Evidence suggests that the complement system is critical to tumor development, and recent studies highlight the role of adipsin in breast cancer growth. In a previous study, we characterized the role of complement pathway-mediated adipsin in ESR1 mutant cell lines (Y537S and D538G), identifying the upregulation of adipsin, C3, and C3aR in ESR1 mutant cells. The interaction between C3a and C3aR enhanced ESR1 mutant cell growth, and inhibiting C3aR abolished cell growth and increased apoptosis. Combining C3aR inhibitors with fulvestrant or CDK4/6 inhibitors had a synergistic inhibitory effect on ESR1 mutant cells. Our findings suggest that the complement pathway plays a role in ESR1 mutant cell proliferation and that C3aR is a potential target to mitigate ESR1 mutant breast cancer growth and metastasis. Additionally, we demonstrated the critical role of the feedback loop of adipsin in ESR1 mutant cell growth in adipocyte crosstalk. Using differentiated mouse 3T3-L1 adipocytes induced with tumor-conditioned media from ESR1 mutant cells, we observed the upregulation of adipsin, C3, and C3a in the adipocyte secretome, which enhanced C3a levels. Blocking the interaction between C3a and C3aR in ESR1 mutant cells using a C3aR inhibitor significantly inhibited ESR1 mutant cell growth compared to wild-type cells and enhanced apoptosis. Our findings suggest that upregulation of adipsin from ESR1 mutant cells and adipocytes in crosstalk increases tumor cell growth. Future studies will investigate the critical role of adipsin's auto- and paracrine effects in breast cancer with ESR1 mutations. Citation Format: Artem Belyakov, Kideok Jin. Crosstalk between adipocyte and tumor cells with ESR1 mutations via adipsin enhances tumor growth [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-25-05.

Post-COVID Trajectory of Pentraxin 3 Plasma Levels Over 6 Months and Their Association with the Risk of Developing Post-Acute Depression and Anxiety.

Clinical manifestations of coronavirus disease 2019 (COVID-19) often persist after acute disease resolution. Underlying molecular mechanisms are unclear. The objective of this original article was to longitudinally measure plasma levels of markers of the innate immune response to investigate whether they associate with and predict post-COVID symptomatology. Adult patients with previous severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection during the first pandemic wave who underwent the 6-month multidisciplinary follow-up were included. Plasma levels of pentraxin 3 (PTX3), the complement components C3a and C5a, and chitinase-3 like-protein-1 (CHI3L1) were measured at hospital admission during acute disease (baseline) and at 1 and 6 months after hospital discharge. Associations with post-COVID-19 sequelae at 6 months were investigated using descriptive statistic and multiple regression models. Ninety-four COVID-19 patients were included. Baseline PTX3, C5a, C3a, and CHI3L1 did not predict post-COVID-19 sequelae. The extent of the reduction of PTX3 over time (delta PTX3) was associated with lower depressive and anxiety symptoms at 6 months (both p < 0.05). When entering sex, age, need for intensive care unit or non-invasive ventilation during hospital stay, psychiatric history, and baseline PTX3 as nuisance covariates into a generalized linear model (GLM), the difference between baseline and 6-month PTX3 levels (delta PTX3) significantly predicted depression (χ2 = 4.66, p = 0.031) and anxiety (χ2 = 4.68, p = 0.031) at 6 months. No differences in PTX3 levels or PTX3 delta were found in patients with or without persistent or new-onset other COVID-19 symptoms or signs at 6 months. Plasma levels of C3a, C5a, and CHI3L1 did not correlate with PTX3 levels at either time point and failed to associate with residual or de novo respiratory or systemic clinical manifestations of the disease at 6 months. A lower reduction of plasma PTX3 after acute COVID-19 associates with the presence of depression and anxiety, suggesting an involvement of inflammation in post-COVID-19 psychopathology and a potential role of PTX3 as a biomarker.

Circulating mortalin in blood and activation of the alternative complement pathway as risk indicators in COVID-19 infection.

Mortalin/GRP75 is a ubiquitous mitochondrial chaperone related to the cytosolic heat shock protein 70. It protects cells from various types of damages and from senescence. Our goal was to determine whether COVID-19 patients have circulating mortalin in their blood and to assess its prognostic value in anticipating disease severity. Mortalin was determined by ELISA in the sera of 83 COVID-19 patients enrolled in the study. Patients were categorized into 4 groups: critical patients who died (FATAL) or required intensive care and survived (ICU), patients of mild severity (hospitalized but not critical) who required nasal oxygen support (HOSP+O2), and patients who did not need oxygen therapy (HOSP). The mortalin concentration in the serum of all COVID-19 patients in the cohort was 194-2324 pg/mL. A comparison of the mortalin levels by peak severity among the various patient groups showed a highly significant difference between the HOSP and FATAL groups and a significant difference between the HOSP and the ICU groups. COVID-19 patients who eventually failed to survive had at hospitalization a markedly higher level of mortalin in their sera. Cox regression analysis revealed a high mortality hazard (HR=3.96, p<0.01) in patients with high mortalin circulating levels (above the median, ≥651 pg/mL). This was confirmed in survival curve analysis (Kaplan-Meier; p=0.0032, log-rank test). Mortalin remained an independent predictor of mortality even after adjusting for age and sex or various complement activation products. Complement activation data collected in an earlier study in the same cohort was compared regarding the mortalin levels. Patients with higher circulating mortalin levels also had higher levels of complement C3a but reduced levels of properdin. This is the first report on circulating mortalin in COVID-19 patients. Higher mortalin levels were associated with more severe illnesses and a higher risk of death. We claim that quantifying the blood levels of mortalin and activated complement proteins will provide important information on the prognosis of COVID-19 patients and will serve as a useful tool for guiding their clinical management and treatment.

Idiopathic multicentric Castleman disease - TAFRO results in high levels of mTOR activator SVEP1, tissue factor, and endotheliopathy

AbstractIdiopathic multicentric Castleman disease (iMCD) is an inflammatory disease associated with a cytokine storm, activation of the PI3K/AKT/mTOR pathway, coagulopathy, and increased risk of thrombosis. The mechanisms underlying these pathologic processes remain elusive. We studied novel markers of mTOR activation and thrombosis in 1 patient with typical features of iMCD with TAFRO (thrombocytopenia, anasarca, fevers, reticulin myelofibrosis, and organomegaly) syndrome (iMCD-TAFRO). Plasma levels of SVEP1 (Sushi, von Willebrand factor type A, epidermal growth factor, and pentraxin domain–containing 1 protein), a newly identified mTOR activator associated with cardiovascular diseases and dementia, in addition to cytokines, chemokines and components of the coagulation cascade and complement system were evaluated by enzyme-linked immunosorbent assay (ELISA) and arrays. Compared with healthy controls, a 15-fold increase in SVEP1 was observed. High levels of factor VIIa/antithrombin and microparticles expressing functional tissue factor (TF) were detected. The anticoagulants thrombomodulin and soluble endothelial protein C receptor were elevated, indicating shedding from endothelial cells. Plasminogen activator inhibitor 1 was increased, consistent with hypofibrinolysis, whereas high levels of C3b and C5a are in keeping with complement activation. Furthermore, markers of endothelial cell activation (e.g. von Willebrand factor, angiopoietin-2), cell adhesion molecules, and angiogenesis mediators were upregulated. SVEP1 emerges as a potential mechanism of mTOR activation in iMCD-TAFRO, while multiple pathways influence coagulopathy. Immunothrombosis emerges as a potential therapeutic target for iMCD.

Significant beneficial effects of 12-weeks add-on yoga therapy on antipsychotic-stabilized schizophrenia patients through epigenetic modulation: novel findings from a randomized controlled study

IntroductionComplementary and alternative therapy, especially yoga, is emerging as an important treatment modality for various complex disorders. Yoga therapy has reportedly been demonstrated to exhibit clinical benefits in schizophrenia. However, the modulatory effects of yoga therapy on the pathobiological pathways of schizophrenia are inadequately explored. Immune dysregulation is a widely recognized etiopathological construct of schizophrenia. It is not precisely known whether yoga therapy can modulate the expression of immune molecules by regulating gene expression and epigenetic processes in schizophrenia.ObjectivesTo understand the impact of 12-weeks add-on yoga therapy on the immune-inflammatory pathway in schizophrenia by examining plasma levels and gene expression levels of cytokines and complement proteins as well as by profiling promoter DNA methylation pattern of genes coding for cytokines and complement proteins.MethodsFifty-seven schizophrenia patients fulfilling DSM-V criteria were recruited into the study and randomized into Yoga therapy (n=28) and waitlist control (n=29) groups. Plasma levels of IL-1β, IL-6, IL-10, IL-17, C1q, C2, C3, C4, C5, C5a, Factor B and Factor H by Multiplex Suspension Assay, quantification of gene expression of Il1b, Il6, Il10, IL17, C3, C4 and C5 genes by quantitative PCR and promoter DNA methylation of Il1b, Il6, Il10, Il17, C3, C4 and C5 genes by pyrosequencing were carried out in all the study participants.ResultsPlasma levels of IL-1β (Z score= 2.42, p=0.02) dropped significantly and C2 (Z score= 2.24, p=0.03) levels increased after 12-weeks of yoga therapy. The expression of Il1b (Z score=2.45, p=0.01) and Il6 (Z score=2.07, p=0.04) genes were significantly downregulated, while the levels of C4 (Z score=2.23, p=0.03) gene was upregulated in schizophrenia patients of yoga therapy group. Two CpG sites in the promoter region of Il1b (all p≤0.05) and Il6 (all p≤0.05) genes and three CpG sites in the promoter region of C4 (all p&lt;0.05) gene were hypermethylated, while two CpG sites in the gene body of Il6 (all p≤0.05) gene and two CpG sites in the promoter region of Il10 (all p ≤0.05) gene were hypomethylated after 12-weeks of yoga therapy in schizophrenia patients.ConclusionsOur findings provide important insights into the mode of action of yoga therapy in schizophrenia. This study for the first time reports the epigenetic effects of yoga therapy on immune-inflammatory pathway in schizophrenia.Disclosure of InterestNone Declared

Complement C5a Receptor Signaling Alters Stress Responsiveness and Modulates Microglia Following Chronic Stress Exposure

BackgroundAccumulating evidence underscores the pivotal role of heightened inflammation in the pathophysiology of stress-related diseases, but the underlying mechanisms remain elusive. The complement system, a key effector of the innate immune system, produces the C5–cleaved activation product C5a upon activation, initiating inflammatory responses through the canonical C5a receptor 1 (C5aR1). While C5aR1 is expressed in stress-responsive brain regions, its role in stress responsiveness remains unknown. MethodsTo investigate C5a-C5aR1 signaling in stress responses, mice underwent acute and chronic stress paradigms. Circulating C5a levels and messenger RNA expression of C5aR1 in the hippocampus and adrenal gland were measured. C5aR1-deficient mice were used to elucidate the effects of disrupted C5a-C5aR1 signaling across behavioral, hormonal, metabolic, and inflammation parameters. ResultsChronic restraint stress elevated circulating C5a levels while reducing C5aR1 messenger RNA expression in the hippocampus and adrenal gland. Notably, the absence of C5aR1 signaling enhanced adrenal sensitivity to adrenocorticotropic hormone, concurrently reducing pituitary adrenocorticotropic hormone production and enhancing the response to acute stress. C5aR1-deficient mice exhibited attenuated reductions in locomotor activity and body weight under chronic stress. Additionally, these mice displayed increased glucocorticoid receptor sensitivity and disrupted glucose and insulin homeostasis. Chronic stress induced an increase in C5aR1-expressing microglia in the hippocampus, a response mitigated in C5aR1-deficient mice. ConclusionsC5a-C5aR1 signaling emerges as a key metabolic regulator during stress, suggesting that complement activation and dysfunctional C5aR1 signaling may contribute to neuroinflammatory phenotypes in stress-related disorders. The results advocate for further exploration of complement C5aR1 as a potential therapeutic target for stress-related conditions.