Expression Of C3 Research Articles

Complement proteins detected through iTRAQ-based proteomics analysis of serum from black carp Mylopharyngodon piceus in response to experimentally induced Aeromonas hydrophila infection.

The black carp Mylopharyngodon piceus is one of the culturally important '4 famous domestic fishes' in China. Recently, infectious diseases caused by Aeromonas hydrophila have drastically altered the operation of the black carp farming industry. In the present study, isobaric tags for relative and absolute quantitation (iTRAQ) were combined with mass spectrometry analysis to screen for differentially abundant black carp serum proteins in response to experimentally induced A. hydrophila infection. A total of 86 differentially abundant proteins were quantified at 24 h post-infection, including 78 down-regulated proteins and 8 up-regulated proteins. The down-regulated proteins included complement C1q subcomponent subunit C, complement factor B/C2A, complement factor B/C2B, complement C3-Q1, complement C3, and complement C4-2. Bioinformatic analysis indicated that the differentially abundant proteins were mainly associated with complement and coagulation cascades (27.9%). Moreover, real-time PCR (qPCR) analysis revealed changes in the gene expression of both C3 and B/C2A in blood cells, liver, kidney, gills, and intestines of the black carp infected with A. hydrophila. However, mRNA expression levels did not consistently correlate with the corresponding protein levels. A polyclonal antibody was prepared using a synthetic C3 peptide. Immunofluorescence analysis showed that the expression of C3 in the kidney was increased with A. hydrophila infection. This work provides a useful characterization of the impact of A. hydrophila infection on the complement system of the black carp.

Podocytes Produce and Secrete Functional Complement C3 and Complement Factor H.

Podocytes are an important part of the glomerular filtration barrier and the key player in the development of proteinuria, which is an early feature of complement mediated renal diseases. Complement factors are mainly liver-born and present in circulation. Nevertheless, there is a growing body of evidence for additional sites of complement protein synthesis, including various cell types in the kidney. We hypothesized that podocytes are able to produce complement components and contribute to the local balance of complement activation and regulation. To investigate the relevant balance between inhibiting and activating sides, our studies focused on complement factor H (CFH), an important complement regulator, and on C3, the early key component for complement activation. We characterized human cultured podocytes for the expression and secretion of activating and regulating complement factors, and analyzed the secretion pathway and functional activity. We studied glomerular CFH and C3 expression in puromycin aminonucleoside (PAN) -treated rats, a model for proteinuria, and the physiological mRNA-expression of both factors in murine kidneys. We found, that C3 and CFH were expressed in cultured podocytes and expression levels differed from those in cultivated glomerular endothelial cells. The process of secretion in podocytes was stimulated with interferon gamma and located in the Golgi apparatus. Cultured podocytes could initiate the complement cascade by the splitting of C3, which can be shown by the generation of C3a, a functional C3 split product. C3 contributed to external complement activation. Podocyte-secreted CFH, in conjunction with factor I, was able to split C3b. Podocytes derived from a patient with a CFH mutation displayed impaired cell surface complement regulation. CFH and C3 were synthesized in podocytes of healthy C57Bl/6-mice and were upregulated in podocytes of PAN treated rats. These data show that podocytes produce functionally active complement components, and could therefore influence the local glomerular complement activation and regulation. This modulating effect should therefore be considered in all diseases where glomerular complement activation occurs. Furthermore, our data indicate a potential novel role of podocytes in the innate immune system.

Abstract 5425: Novel molecular subtypes identified in prostate cancer: Results from the SPARTAN study

Abstract Background: Results from SPARTAN, a phase III placebo (PBO)-controlled study in patients (pts) with nonmetastatic castration-resistant prostate cancer (nmCRPC), show that apalutamide (APA) plus ongoing androgen deprivation therapy (ADT) significantly improves metastasis-free survival (MFS) compared with PBO + ADT. This analysis investigated the effects of APA in biologically distinct molecular subclasses of prostate cancer defined by gene expression profiles. Methods: Gene expression profiles (DECIPHER® prostate test, San Diego, CA) were generated from 233 archival primary prostate tumors; data were summarized based on 160 predefined gene signatures indicative of clinical prognosis and prostate cancer-related biology. Unsupervised consensus clustering identified sets of co-regulated expression signatures, and associations between signature expression, treatment, and signature-treatment interaction with MFS were evaluated using Kaplan-Meier analysis and Cox proportional hazards models. Results: Four co-regulated expression signature classes, each with distinct biological pathway functions, were identified. Class C1 included prognosis-related (risk) signatures; C2 included steroid homeostasis-related signatures; C3 included hormonal therapy nonresponsive basal and neuroendocrine-like signatures; C4 included immune and stromal signatures. Increased C1 expression was associated with shorter MFS in the PBO group (HR [95% CI], 2.18 [1.11-4.28], p = 0.02), while it was associated with longer MFS in the APA group (interaction HR [95% CI], APA vs PBO, 0.36 [0.14-0.95], p = 0.04). Similarly, increased C2 expression was associated with shorter MFS in the PBO group (HR [95% CI], 1.42 [1.02-1.98], p = 0.04), while it was associated with longer MFS in the APA group (interaction HR [95% CI], APA vs PBO, 0.57 [0.35-0.93], p = 0.02). Although there is no significant interaction effect between signature and treatment in C3, pts with low expression of C3 (adeno-like) showed longer MFS on APA vs PBO (HR [95% CI], 0.23 [0.13-0.40], p < 0.0001) compared with high-C3-expressing neuroendocrine-like tumors. Increased C4 expression was associated with decreased risk of metastasis in the APA group (HR [95% CI], 0.55 [0.35-0.86], p = 0.008) compared with PBO (interaction HR [95% CI], APA vs PBO, 0.53 [0.28-0.98], p = 0.04). Conclusion: Expression signatures were clustered into 4 correlated unique biological subclasses. Clinical benefit of APA + ADT was observed in pts with expression profiles with high risk (C1), C2, C3, or C4 compared with PBO + ADT. Citation Format: Clemente Aguilar, Michael Gormley, Shibu Thomas, Paul N. Mainwaring, David Olmos, Fred Saad, Simon Chowdhury, Elai Davicioni, Yang Liu, Deborah S. Ricci, Angela Lopez-Gitlitz, Margaret K. Yu, Matthew R. Smith, Eric J. Small, Felix Feng. Novel molecular subtypes identified in prostate cancer: Results from the SPARTAN study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5425.

RETRACTED: Two Cu(II)-based coordination polymers: Photocatalytic dye degradation and treatment activity combined with BDNF modified bone marrow mesenchymal stem cells on craniocerebral trauma via increasing complement C3 expression

Abstract Two novel mixed-ligand Cu(II) coordination polymers (CPs) {[Cu2(edpc)2(ga)2]·2H2O}n (1) and {[Cu(edpc)(bpdc)]·0.25(H2O)}n (2) (H2ga = glutaric acid, edpc = 9-ethyl-2,6-di-pyridin-4-yl-9H-carbazole, H2bpdc = biphenyl-4,4′-dicarboxylic acid) have been solvothermally formed through a π-conjugated carbazole-containing pyridine ligand under the presence of auxiliary ligands (H2ga for the complex 1 and H2bpdc for complex 2). Due to its good water stability of complex 2, it was applied in the photocatalytic rhodamine B (RhB), methylene blue (MB) and methyl orange (MO) degradation in unclean water, and the possible pathway of photocatalytic degradation was researched. Whether the compounds could enhance the treatment activity of the BDNF modified bone marrow mesenchymal stem cells (BMSC) against craniocerebral trauma was then evaluated. The recognition of the craniocerebral trauma mice was assessed by Morris water maze (MWM). The viability of the nerve cells in the brain was evaluated by Cell Counting Kit-8 (CCK-8). Then the enzyme-linked immuno sorbent assay (ELISA) detection was performed to detect the release content of the brain-originated neurotrophic factor and nerve promoting factor β in peripheral regions of cerebral hemorrhage. Finally, the expression levels of the complement C3 receptor on the nerve cells in the brain was also determined.

In Vivo Assessment of Cell Death and Nigrostriatal Pathway Integrity Following Continuous Expression of C3 Transferase

The bacterial exoenzyme C3 transferase (C3) irreversibly inhibits RhoA GTPase leading to stimulation of axonal outgrowth in injured neurons. C3 has been used successfully in models of neurotrauma and shows promise as an option to support cell survival and axonal growth of dopaminergic (DA) neurons in Parkinson’s disease (PD) cell therapy. Whether the continuous expression of C3 in DA neurons is well-tolerated is unknown. To assess the potential neurotoxicity of sustained expression of C3 in DA neurons, we generated Cre recombinase-dependent adeno-associated viral vectors (AAV) for targeted C3 delivery to DA neurons of the mouse substantia nigra pars compacta (SNc). The effect of continuous expression of C3 on DA neurons was assessed by immunohistochemistry and compared to that of Enhanced Yellow Fluorescent Protein (EYFP) as negative controls. We did not find significant reduction of tyrosine hydroxylase (TH) expression levels nor the presence of cleaved activated caspase 3. Astrocytic activation as determined by GFAP expression was comparable to EYFP controls. To evaluate the impact of C3 expression on striatal terminals of the nigrostriatal pathway, we compared the rotational behavior of wildtype mice injected unilaterally with either C3 or 6-hydroxydopamine (6-OHDA). Mice injected with C3 exhibited similar ipsiversive rotations to the site of injection in comparison to control mice injected with EYFP and significantly fewer ipsiversive rotations compared to 6-OHDA lesioned mice. Non-significant difference between C3 and EYFP controls in behavioral and histological analyses demonstrate that transduced DA neurons express C3 continuously without apparent adverse effects, supporting the use of C3 in efficacy studies targeting DA neurons.

Identification of DEGs and transcription factors involved in H. pylori-associated inflammation and their relevance with gastric cancer.

BackgroundPrevious studies have indicated that chronic inflammation linked to H. pylori infection is the leading causes for gastric cancer (GC). However, the exact mechanism is not entirely clear until now.PurposeTo identify the key molecules and TFs involved in H. pylori infection and to provide new insights into H. pylori-associated carcinogenesis and lay the groundwork for the prevention of GC.ResultsGO and KEGG analysis revealed that the DEGs of Hp+-NAG were mainly associated with the immune response, chemokine activity, extracellular region and rheumatoid arthritis pathway. The DEGs of Hp+-AG-IM were related to the apical plasma membrane, intestinal cholesterol absorption, transporter activity and fat digestion and absorption pathway. In Hp+-NAG network, the expression of TNF, CXCL8, MMP9, CXCL9, CXCL1, CCL20, CTLA4, CXCL2, C3, SAA1 and FOXP3, JUN had statistical significance between normal and cancer in TCGA database. In Hp+-AG-IM network the expression of APOA4, GCG, CYP3A4, XPNPEP2 and FOXP3, JUN were statistically different in the comparison of normal and cancer in TCGA database. FOXP3 were negatively associated with overall survival, and the association for JUN was positive.ConclusionThe current study identified key DEGs and their transcriptional regulatory networks involved in H. pylori-associated NAG, AG-IM and GC and found that patients with higher expressed FOXP3 or lower expressed JUN had shorter overall survival time. Our study provided new directions for inflammation-associated oncogenic transformation involved in H. pylori infection.

In vivo effects on the immune function of fathead minnow (Pimephales promelas) following ingestion and intraperitoneal injection of polystyrene nanoplastics

Nanoplastics (1–100 nm) are potentially the most hazardous litter in the environment. Recent scientific studies have documented their toxic effects at the cellular and molecular levels, but knowledge underlying mechanisms of their toxicity is still scarce. Nanoplastics are known for their ability to induce immune and inflammatory responses as well as generating reactive oxygen species. While some studies have addressed the immunotoxicity of nanoplastics in vitro and on in vivo in fish after intraperitoneal injection, no information is available on adult fish after ingestion of a contaminated prey. The present study is the first to attempt to address the immunotoxicity of nanoplastics in adult fish after trophic transfer. Pimephales promelas is a well-established bioindicator species to study the immunotoxicity of nanoparticles and the innate immune responses of fish. This study aims to assess the in vivo innate immune response of adult P. promelas following exposure to polystyrene nanoplastics by measuring the gene expression of ncf, nox2, mst1 and c3; these genes are related with the immune function of neutrophils, macrophages and complement in fish. Two target organs (liver and head kidney) and two routes of exposure (IP- injection and ingestion) were analyzed. After 48 h of exposure, polystyrene nanoplastics were encountered in the liver and kidney of both IP-injection and ingestion exposed fish, and significantly affected the innate immune system of P. promelas by downregulating the gene expression ncf, mst1, and c3 in liver and kidney. Significant difference between treatments was only observed for the gene expression of nfc in liver. Results of this study indicate that polystyrene nanoplastics can exhibit immunotoxicity in fish through an environmentally relevant route of exposure, interfering with the synthesis and function of neutrophils, macrophages, and complement of P. promelas in their principal hematopoietic tissues, which may potentially compromise its ability to survive in nature.

Diapedesis and LFA-1 mediate tissue immune cell effector activity via intrinsic complement C3 licensing

Abstract Intracellularly generated and autocrine-functioning complement component C3 is a critical integral part of normal human CD4+ Th1 and cytotoxic CD8+ T cells responses. Increased or decreased intracellular C3 result in autoimmunity and infections, respectively. The mechanisms regulating intracellular C3 expression are, however, undefined. By comparing transcriptomes from blood and tissue, we identified the complement system, including C3, as one of the most significantly enriched biological pathways in tissue-occupying cells of human macrophages, CD4+ and CD8+ T cells. By leveraging a novel C3 reporter mouse, we confirmed that C3 gene transcription is a feature of immune cells in tissues, is induced during trans-endothelial diapedesis, and is dependent on the integrin intercellular adhesion molecule (ICAM)-1 liganding lymphocyte function-associated antigen (LFA)-1. Consequently, monocytes and T cells from patients with leukocyte adhesion deficiency (LAD)-1 had reduced C3 and diminished effector activities, which could be rescued proportionally by normalization of intracellular C3. In synovia of patients with rheumatoid arthritis (RA), C3 transcript expression by CD4+ T cells was linearly associated with disease severity and acted as a biomarker distinguishing inflamed versus uninflamed RA. Our study defines the integrin network as a novel and key controller of intracellular complement, demonstrates that perturbations in the LFA-1–C3 axis contribute to primary human immunodeficiency and identifies T cell C3 production as a biomarker of the severity of autoimmunity.

Effect of Hyperbaric Oxygen on Tissue Damage and Expression of Adhesion Molecules and C3 in a Rat Model of Renal Ischemia-Reperfusion Injury After Kidney Transplantation.

BackgroundThe aim of this study was to investigate the protective effect and mechanism of hyperbaric oxygen (HBO) in a rat model of renal ischemia-reperfusion injury following kidney transplantation.Material/MethodsSprague Dawley rats were randomly divided into 3 groups (n=18): sham group, kidney transplantation group, and HBO treatment group. Six rats in each group were sacrificed at 1, 3, and 5 hours after reperfusion, and serum and renal tissue were then collected. The serum creatinine levels and histopathological changes of the renal tissue were detected. ICAM-1, VCAM-1, and C3 expression levels were also detected by immunohistochemical staining or real-time polymerase chain reaction.ResultsRenal function was damaged in the kidney transplantation group and the HBO treatment group compared with sham group (P<0.05). Renal histopathological changes, including tubular cell swelling, tubular dilatation, and hyaline casts, were remarkably reduced in the HBO treatment group compared to the kidney transplantation group. In the immunohistochemical examination, the expression levels of ICAM-1, VCAM-1, and C3 were obviously increased in the kidney transplantation group and the HBO treatment group; moreover, the levels in the HBO treatment group were significantly lower than in the kidney transplantation group (P<0.05). In addition, the ICAM-1 and C3 mRNA levels were increased in the kidney transplantation group and HBO treatment group, but the levels of in the HBO treatment group them were significantly decreased compared to the kidney transplantation group that at 3 and 5 hours after reperfusion (P<0.05).ConclusionsHBO treatment exerted a protective effect on renal function through inhibition of adhesion molecule overexpression and complement system activation in a rat model of renal ischemia-reperfusion injury after kidney transplantation.

Screening for protective antigens of Cyprinid herpesvirus 2 and construction of DNA vaccines

BackgroundIn recent years, crucian carp hematopoietic necrosis caused by Cyprinid herpesvirus 2 (CyHV-2) infection has caused an enormous economic loss to the aquaculture industry. MethodsIn this study antigenic epitope analysis was performed on the membrane proteins of CyHV-2, and 8 antigen-rich peptide fragments were selected for prokaryotic expression. Then, the immunogenicity of the recombinant proteins was analyzed. On this basis, DNA vaccines were constructed for immunization of hybridized Prussian carps. The protective effect of DNA vaccines against challenge in hybridized Prussian carps was evaluated. ResultsThe results showed that all 8 recombinant proteins were successfully expressed. Among the recombinant proteins, ORF16, tORF25, tORF64, and ORF146, gave a positive serum reaction with CyHV-2. Of the four proteins used for the immunization of silver crucian carps, the antibody titer induced by tORF25 was the highest. The DNA vaccine, pEGFP-N1-ORF25, was constructed based on ORF25 and able to induce production of specific antibodies in carps, while up-regulating the expression of MHCⅠ, IL-1β, C3, and TF-A in the kidneys of carps. Moreover, the immunoprotective rate was increased to 70% in hybridized Prussian carps. ConclusionThe results showed that the DNA vaccine constructed based on the ORF25 gene had a greater immune protective effect and can be used as a candidate vaccine for immunoprotection against CyHV-2.

Repeated hormonal induction of spermiation affects the stress but not the immune response in pikeperch (Sander lucioperca)

Hormonal induction of spermiation, previously reported to be immunogenic in fishes, is a common hatchery practice in pikeperch, Sander lucioperca. The aim of the present study was to investigate the effects of repeated induction of spermiation in pikeperch, following application of either human chorionic gonadotropin (hCG) or salmon gonadoliberine analogue (sGnRHa) on sperm quality indices as well as on immune and stress response. Mature males of pikeperch (n = 7 per group) were stimulated twice with five days between injections of either hCG (hCG; 500 IU kg−1), sGnRHa (sGnRHa; 50 μg kg−1) or NaCl (control group; 1 ml kg−1) to assess spermatozoa motility with a computer-assisted sperm analysis (CASA) system. During second sampling, blood plasma was sampled for humoral innate immune (peroxidase and lysozyme activities, ACH50), stress (cortisol, glucose) and endocrine (testosterone) markers. In addition, the head kidney was dissected to assay the expression of several immune genes (such as il1, c3, hamp, tnf-α and lys genes). The results indicate that hormonal treatment significantly increased sperm production. Sperm sampled after the hormonal treatment maintained its quality throughout the study, regardless of the sampling time. However, it appears that the application of hCG induced elevated cortisol and glucose plasma levels compared to the control group. Almost all immune markers, except the relative expression of hepcidin (hamp gene), were unaffected by the two hormones applied. The results showed that the induction treatment of spermiation processes in pikeperch resulted in an important physiological stress response for which the intensity varied according to the hormonal agent used. However, this stress response (more profound following application of hCG) was weakly associated with innate immune functions. On the other hand, a significant negative correlation between the expression of several important immune markers (peroxidase activity, relative expression of c3 and il1 genes) and sperm quality indices indicates significant involvement of immune status on sperm quality. The results obtained shed light on immune-system-induced modifications to sperm quality. The data presented here highlight the need for careful revision of broodstock management and selection practices where welfare status as well as individual predispositions of fish to cope with the stress should be taken under the consideration.

Diapedesis-Induced Integrin Signaling via LFA-1 Facilitates Tissue Immunity by Inducing Intrinsic Complement C3 Expression in Immune Cells

Intrinsic complement C3 activity is integral to human T helper type 1 (Th1) and cytotoxic Tcell responses. Increased or decreased intracellular C3 results in autoimmunity and infections, respectively. The mechanisms regulating intracellular C3 expression remain undefined. We identified complement, including C3, as among the most significantly enriched biological pathway in tissue-occupying cells. We generated C3-reporter mice and confirmed that C3 expression was a defining feature of tissue-immunecells, including Tcells and monocytes, occurred during transendothelial diapedesis, and depended on integrin lymphocyte-function-associated antigen 1 (LFA-1) signals. Immune cells from patients with leukocyte adhesion deficiency type 1 (LAD-1) had reduced C3 transcripts and diminished effector activities, which could be rescued proportionally by intracellular C3 provision. Conversely, increased C3 expression by Tcells from arthritis patients correlated with disease severity. Our study defines integrins as key controllers of intracellular complement, demonstrates that perturbations in the LFA-1-C3-axis contribute to primary immunodeficiency, and identifies intracellular C3 as biomarker of severity in autoimmunity.

Estrogen enhances the proliferation and migration of ovarian cancer cells by activating transient receptor potential channel C3

BackgroundRecent studies have suggested that estrogen (E2) plays an important role in epithelial ovarian cancer (EOC). However, the mechanism of E2 in ovarian cancers is unclear. The purpose of this study was to investigate the effect of E2 on ovarian cancers and illuminate the mechanism of E2 in promote ovarian cancers proliferation.ResultsWe demonstrated that E2 stimulated the proliferation and invasion of ovarian cancer cells. In this study, ovarian cancer specimens were also analyzed for transient receptor potential channel C3 (TRPC3) expression; TRPC3 expression levels were higher in ovarian cancer samples than in normal ovarian tissue samples. Previous studies have shown that TRPC3 contributes to the progression of human ovarian cancer. In this study, we further investigated the interaction between E2 and TRPC3. We found that E2 stimulation enhanced the expression of TRPC3 at both the mRNA and protein levels. E2 stimulation enhanced the influx of Ca2+. Moreover, siRNA-mediated silencing of TRPC3 expression inhibited the ability of E2 to stimulate the influx of Ca2+.ConclusionsIn conclusion, TRPC3 plays a significant role in the stimulatory activity of E2 and could be a therapeutic target for the treatment of EOC. Furthermore, this study elucidates the molecular mechanism by which E2 promotes the proliferation and migration of EOC cells.

Dietary cadmium chloride impairs shell biomineralization by disrupting the metabolism of the eggshell gland in laying hens.

In this study, we identified cadmium (Cd) as a potential endocrine disruptor that impairs laying performance, egg quality, and eggshell deposition and induces oxidative stress and inflammation in the eggshell glands of laying hens. A total of 480 38-wk-old laying hens were randomly assigned into 5 groups that were fed a basal diet (control) or a basal diet supplemented with Cd (provided as CdCl2·2.5 H2O) at 7.5, 15, 30, and 60 mg Cd per kg feed for 9 wk. The results showed that, when compared with the control group, a low dose of dietary Cd (7.5 mg/kg) had positive effects on egg quality by improving albumen height, Haugh unit, yolk color, and shell thickness at the third or ninth week. However, with the increase in the dose and duration of Cd exposure, the laying performance, egg quality, and activities of eggshell gland antioxidant enzymes (catalase [CAT], glutathione peroxide [GSH-Px]), and ATPase (Na+/K+-ATPase, Ca2+-ATPase, and Mg2+-ATPase) deteriorated, and the activity of total nitric oxide synthase (T-NOS) and the level of malondialdehyde (MDA) increased significantly (P < 0.05). The histopathology and real-time quantitative PCR results showed that Cd induced endometrial epithelial cell proliferation accompanied by upregulation of the mRNA levels of progesterone receptor (PgR) and epidermal growth factor receptor (EGFR), downregulation of the mRNA levels of estrogen receptor α (ERα) and interleukin 6 (IL6), and inflammation of the eggshell gland accompanied by significantly increased expression of complement C3 and pro-inflammatory cytokine tumor necrosis factor α (TNFα) (P < 0.05). In addition, the ultrastructure of the eggshell showed that dietary supplementation with 7.5 mg/kg Cd increased the palisade layer and total thickness of the shell, but with the increase in dietary Cd supplementation (30 and 60 mg/kg) the thickness of the palisade layer and mammillary layer decreased significantly (P < 0.05), and the outer surface of the eggshell became rougher. Correspondingly, the expression of calbindin 1 (CALB1), ovocalyxin-32 (OCX-32), ovocalyxin-36 (OCX-36), osteopontin (SPP1), and ovocledidin-17 (OC-17) decreased significantly (P < 0.05) with increasing dietary Cd supplementation. Conclusively, the present study demonstrates that dietary supplementation with Cd negatively affects laying performance, egg quality, and eggshell deposition by disturbing the metabolism of eggshell glands in laying hens but has a positive effect on egg quality at low doses.

Increased expression of schizophrenia-associated gene C4 leads to hypoconnectivity of prefrontal cortex and reduced social interaction.

Schizophrenia is a severe mental disorder with an unclear pathophysiology. Increased expression of the immune gene C4 has been linked to a greater risk of developing schizophrenia; however, it is not known whether C4 plays a causative role in this brain disorder. Using confocal imaging and whole-cell electrophysiology, we demonstrate that overexpression of C4 in mouse prefrontal cortex neurons leads to perturbations in dendritic spine development and hypoconnectivity, which mirror neuropathologies found in schizophrenia patients. We find evidence that microglia-mediated synaptic engulfment is enhanced with increased expression of C4. We also show that C4-dependent circuit dysfunction in the frontal cortex leads to decreased social interactions in juvenile and adult mice. These results demonstrate that increased expression of the schizophrenia-associated gene C4 causes aberrant circuit wiring in the developing prefrontal cortex and leads to deficits in juvenile and adult social behavior, suggesting that altered C4 expression contributes directly to schizophrenia pathogenesis.

Complement C3 overexpression activates JAK2/STAT3 pathway and correlates with gastric cancer progression

BackgroundLocalized C3 deposition is a well-known factor of inflammation. However, its role in oncoprogression of gastric cancer (GC) remains obscured. This study aims to explore the prognostic value of C3 deposition and to elucidate the mechanism of C3-related oncoprogression for GC.MethodsFrom August to December 2013, 106 GC patients were prospectively included. The regional expression of C3 and other effectors in gastric tissues were detected by WB, IHC, qRT-PCR and other tests. The correlation of localized C3 deposition and oncologic outcomes was determined by 5-year survival significance. Human GC and normal epithelial cell lines were employed to detect a relationship between C3 and STAT3 signaling pathway in vitro experiments.ResultsC3 and C3a expression were markedly enhanced in GC tissues at both mRNA and protein levels compared with those in paired nontumorous tissues. According to IHC C3 score, 65 (61.3%) and 41 (38.7%) patients had high and low C3 deposition, respectively. C3 deposition was negatively correlated with plasma levels of C3 and C3a (both P < 0.001) and positively correlated with pathological T and TNM stages (both P < 0.001). High C3 deposition was identified as an independent prognostic factor of poor 5-year overall survival (P = 0.045). In vitro C3 administration remarkably enhanced p-JAK2/p-STAT3 expression in GC cell lines but caused a reduction of such activation when pre-incubated with a C3 blocker. Importantly, C3 failed to activate such signaling in cells pre-treated with a JAK2 inhibitor.ConclusionsLocalized C3 deposition in the tumor microenvironment is a relevant immune signature for predicting prognosis of GC. It may aberrantly activate JAK2/STAT3 pathway allowing oncoprogression.Trial registrationClinicalTrials.gov, NCT02425930, Registered 1st August 2013.

Longitudinal Basal Forebrain Degeneration Interacts with TREM2/C3 Biomarkers of Inflammation in Presymptomatic Alzheimer's Disease.

Cholinergic inputs originating from the peripheral nervous system regulate the inflammatory immune responses of macrophages during clearance of blood-based pathogens. Because microglia are involved in clearing amyloid and tau pathology from the central nervous system, we hypothesized that cholinergic input originating from the basal forebrain might similarly regulate inflammatory immune responses to these pathologies in the aging brain. To explore this hypothesis, we leveraged the Alzheimer's Disease Neuroimaging Initiative dataset. Cognitively normal older male and female human adults were differentiated according to the relative concentration of phosphorylated tau and amyloid in their cerebrospinal fluid, yielding neurotypical and preclinical, cognitively healthy, subgroups. We then tracked these two groups longitudinally with structural MRI and biomarkers of inflammation, including soluble sTREM2 levels in the CSF and complement C3 expression in the blood transcriptome. Longitudinal loss of basal forebrain volume was larger in the preclinical compared with the neurotypical subgroup. Across preclinical adults, loss of basal forebrain volume was associated with greater longitudinal accumulation of sTREM2 and higher peripheral blood C3 expression. None of these relationships were attributable to degeneration in the whole-brain gray matter volume. Preclinical APOE e4 carriers exhibited the largest loss of basal forebrain volume and highest C3 expression. Consistent with the known anti-inflammatory influence of the peripheral cholinergic pathways on macrophages, our findings indicate that a loss of central cholinergic input originating from the basal forebrain might remove a key check on microglial inflammation induced by amyloid and tau accumulation.SIGNIFICANCE STATEMENT In the peripheral nervous system, cholinergic modulation holds the reactivity of macrophages to blood-based pathogens in check, promoting clearance while preventing runaway inflammation and immune-triggered cell death. Microglia are the brain's resident macrophages and play an important role in clearing accumulated amyloid and tau from neurons. Here, we demonstrate that a loss of cholinergic integrity in the CNS, indexed by longitudinal decreases of basal forebrain volume, interacts with multiple biomarkers of inflammation in cognitively normal older adults with abnormal amyloid and tau pathology. These interactions were not detected in cognitively normal older adults with "neurotypical" levels of amyloid and tau. An age-related loss of cholinergic neuromodulation may remove key checks on microglial reactivity to amyloid and tau.

Downregulation of microRNA-101-3p participates in systemic lupus erythematosus progression via negatively regulating HDAC9.

This study aimed to investigate the mechanism of microRNA-101-3p (miR-101-3p) on the progression of systemic lupus erythematosus (SLE). The human peripheral blood mononuclear cells (PBMCs) were isolated from whole blood samples of SLE patients and healthy individuals, followed by cell culture and transfection. Moreover, the flow cytometry assay, quantitative real-time reverse-transcription polymerase chain reaction, Western blot, and enzyme-linked immunoassay were used to assess the effect of miR-101-3p on PBMCs. Bioinformatics analysis was conducted to predict the putative target gene of miR-101-3p, luciferase reporter gene assay, and RNA pull-down assay were applied to verify the interaction between them. Compared with healthy individuals, the expression level of miR-101-3p in PBMCs of SLE patients was significantly decreased, whereas interleukin (IL)-17A, IL-6, and interferon (IFN)-γ were remarkably increased (all P < .001). Correlation analyses showed that there were negative correlations between miR-101-3p and IL-17A, IL-6 and IFN-γ. The expression level of miR-101-3p in PBMCs of SLE patients was positively correlated with C3 expression (rs = .4075; P = .0229), while negatively associated with erythrocyte sedimentation rate (ESR) (rs = -.4238; P = .0175) and IgG expression (rs = -.4949; P = .0047). Overexpression of miR-101-3p could inhibit the differentiation of CD4 + T cells into Th17 lineage. Histone deacetylase 9 (HDAC9) was identified as a potential target gene of miR-101-3p. Furthermore, HDAC9 abolished the effect of miR-101-3p on Th17 cell differentiation and IL-17A expression in SLE. In conclusion, downregulated miR-101-3p in PBMCs of SLE patients inhibited Th17 cell differentiation by directly targeting HDAC9, which could be used as a novel therapeutic therapy for SLE treatment.

Involvement of HSP90 in ischemic postconditioning-induced cardioprotection by inhibition of the complement system, JNK and inflammation.

Purpose To investigate whether heat shock protein 90 (HSP90) is involved in complement regulation in ischemic postconditioning (IPC).Methods The left coronary artery of rats underwent 30 min of occlusion, followed by 120 min of reperfusion and treatment with IPC via 3 cycles of 30s reperfusion and 30s occlusion. The rats were injected intraperitoneally with 1 mg/kg HSP90 inhibitor geldanamycin (GA) after anesthesia. Eighty rats were randomly divided into four groups: sham, ischemia-reperfusion (I/R), IPC and IPC + GA. Myocardial infarct size, apoptosis index and the expression of HSP90, C3, C5a, tumor necrosis factor (TNF)-alpha, interleukin (IL)-1β and c-Jun N-terminal kinase (JNK) were assessed.Results Compared with the I/R injury, the IPC treatment significantly reduced infarct size, release of troponin T, creatine kinase-MB, and lactate dehydrogenase, and cardiomyocyte apoptosis. These beneficial effects were accompanied by a decrease in TNF-α, IL-1β, C3, C5a and JNK expression levels. However, all these effects were abrogated by administration of the HSP90 inhibitor GA.Conclusion HSP90 exerts a profound effect on IPC cardioprotection, and may be linked to the inhibition of the complement system and JNK, ultimately attenuating I/R-induced myocardial injury and apoptosis.

Endothelial progenitor cell transplantation alleviated ischemic brain injury via inhibiting C3/C3aR pathway in mice

Endothelial progenitor cell transplantation is a potential therapeutic approach in brain ischemia. However, whether the therapeutic effect of endothelial progenitor cells is via affecting complement activation is unknown. We established a mouse focal ischemia model (n = 111) and transplanted endothelial progenitor cells into the peri-infarct region immediately after brain ischemia. Neurological outcomes and brain infarct/atrophy volume were examined after ischemia. Expression of C3, C3aR and pro-inflammatory factors were further examined to explore the role of endothelial progenitor cells in ischemic brain. We found that endothelial progenitor cells improved neurological outcomes and reduced brain infarct/atrophy volume after 1 to 14 days of ischemia compared to the control (p < 0.05). C3 and C3aR expression in the brain was up-regulated at 1 day up to 14 days (p < 0.05). Endothelial progenitor cells reduced astrocyte-derived C3 (p < 0.05) and C3aR expression (p < 0.05) after ischemia. Endothelial progenitor cells also reduced inflammatory response after ischemia (p < 0.05). Endothelial progenitor cell transplantation reduced astrocyte-derived C3 expression in the brain after ischemic stroke, together with decreased C3aR and inflammatory response contributing to neurological function recovery. Our results indicate that modulating complement C3/C3aR pathway is a novel therapeutic target for the ischemic stroke.