Project description:Preclinical studies demonstrated that complement promotes tumor growth. Therefore, we sought to determine the best target for complement-based therapy among common human malignancies. High expression of 11 complement genes was linked to unfavorable prognosis in renal cell carcinoma. Complement protein expression or deposition was observed mainly in stroma, leukocytes, and tumor vasculature, corresponding to a role of complement in regulating the tumor microenvironment. Complement abundance in tumors correlated with a high nuclear grade. Complement genes clustered within an aggressive inflammatory subtype of renal cancer characterized by poor prognosis, markers of T cell dysfunction, and alternatively activated macrophages. Plasma levels of complement proteins correlated with response to immune checkpoint inhibitors. Corroborating human data, complement deficiencies and blockade reduced tumor growth by enhancing antitumor immunity and seemingly reducing angiogenesis in a mouse model of kidney cancer resistant to PD-1 blockade. Overall, this study implicates complement in the immune landscape of renal cell carcinoma, and notwithstanding cohort size and preclinical model limitations, the data suggest that tumors resistant to immune checkpoint inhibitors might be suitable targets for complement-based therapy.
Project description:BackgroundScreening abnormal pathways and complement components in the kidneys of patients with lupus nephritis (LN) and NZB/W mice may help to identify complement-related therapeutic targets for LN.MethodsKEGG and GO enrichment assays were used to analyze kidney microarray data of LN patients and NZB/W mice. Immunohistochemistry and immunofluorescence assays were used to measure renal expression of complement-related proteins and TGFβ1. Cytokines were measured using RT-qPCR and ELISA.ResultsWe screened the renal pathogenic pathways present in LN patients and NZB/W mice and selected the complement activation pathway for further study. The results indicated greater renal expression of C1qa, C1qb, C3, C3aR1, and C5aR1 at the mRNA and protein levels. C3 appeared to be a key factor in LN and the renal signaling downstream of C1 was inhibited. There were significant correlations between the expression of TGFβ1 and C3. Analysis of primary cell cultures indicated that TGFβ1 promoted the expression of C3 and that a TGFβ1 antagonist decreased the levels of C3 and C3aR. TGFβ1 inhibition significantly inhibited the deposition of complement-related factors in the kidneys of NZB/W mice.ConclusionsAt the onset of LN, there are significant increases in the renal levels of C3 and other complement pathway-related factors in patients with LN and NZB/W mice. C3 may lead to albuminuria and participate in the pathogenesis of LN. TGFβ1 promotes C3 synthesis, and TGFβ1 inhibition may block the progression of LN by inhibiting the synthesis of C3 and other complement components.
Project description:Systemic lupus erythematosus (SLE) is a rheumatic disease. Growth differentiation factor 15 (GDF-15) is a member of transforming growth factor-β superfamily. To date, association of GDF-15 with SLE pathogenesis is not clarified. This study discussed GDF-15 serum levels and gene polymorphisms in SLE patients and lupus mouse model further demonstrated the role of GDF-15 in lupus development. We conducted two independent case-control studies for SLE patients. One is to evaluate serum levels of GDF-15 in 54 SLE patients and 90 healthy controls, and the other one is to analyze gene polymorphisms of GDF-15 in 289 SLE patients and 525 healthy controls. Serum levels of GDF-15 were detected by ELISA. GDF-15 gene polymorphisms (rs1055150, rs1058587, rs1059519, rs1059369, rs1227731, rs4808793, and rs16982345) were genotyped by the Kompetitive Allele-Specific PCR (KASP) method. Addition of recombinant GDF-15 into pristane-induced lupus mice evaluated histological and serological changes. Results showed that serum levels of GDF-15 were overexpressed in SLE patients and associated with disease activity. Polymorphisms rs1055150, rs1059369, rs1059519, and rs4808793 of GDF-15 gene were related to SLE risk. Lupus mice showed splenomegaly, severe histological scores, and high levels of autoantibodies [antinuclear antibodies (ANA) and total immunoglobulin G (IgG)], whereas administration of GDF-15 into lupus mice reduced the histological changes. Percentages of CD8+, CD11b+, CD19+, CD11C+ cells, TH2 cells, and pro-inflammatory cytokines (IL-1β, IL-2, IL-4, IL-21, and IL-22) were reduced after GDF-15 treatment in lupus mice. In conclusion, GDF-15 was related to lupus pathogenesis and inhibited lupus development.
Project description:Glycosylation is one of the most common forms of protein post-translational modification, but is also the most complex. Dealing with glycoproteins in structure model building, refinement, validation and PDB deposition is more error-prone than dealing with nonglycosylated proteins owing to limitations of the experimental data and available software tools. Also, experimentalists are typically less experienced in dealing with carbohydrate residues than with amino-acid residues. The results of the reannotation and re-refinement by PDB-REDO of 8114 glycoprotein structure models from the Protein Data Bank are analyzed. The positive aspects of 3620 reannotations and subsequent refinement, as well as the remaining challenges to obtaining consistently high-quality carbohydrate models, are discussed.
Project description:Peptidylarginine deiminases (PADs) are a family of calcium-dependent enzymes that are involved in a variety of human disorders, including cancer and autoimmune diseases. Although targeting PAD4 has shown no benefit in sepsis, the role of PAD2 remains unknown. Here, we report that PAD2 is engaged in sepsis and sepsis-induced acute lung injury in both human patients and mice. Pad2-/- or selective inhibition of PAD2 by a small molecule inhibitor increased survival and improved overall outcomes in mouse models of sepsis. Pad2 deficiency decreased neutrophil extracellular trap (NET) formation. Importantly, Pad2 deficiency inhibited Caspase-11-dependent pyroptosis in vivo and in vitro. Suppression of PAD2 expression reduced inflammation and increased macrophage bactericidal activity. In contrast to Pad2-/-, Pad4 deficiency enhanced activation of Caspase-11-dependent pyroptosis in BM-derived macrophages and displayed no survival improvement in a mouse sepsis model. Collectively, our findings highlight the potential of PAD2 as an indicative marker and therapeutic target for sepsis.
Project description:Cutaneous squamous cell carcinoma (cSCC) is the most prevalent metastatic skin cancer. Previous studies have demonstrated the autocrine role of complement components in cSCC progression. We have investigated factor D (FD), the key enzyme of the alternative complement pathway, in the development of cSCC. RT-qPCR analysis of cSCC cell lines and normal human epidermal keratinocytes (NHEKs) demonstrated significant up-regulation of FD mRNA in cSCC cells compared to NHEKs. Western blot analysis also showed more abundant FD production by cSCC cell lines. Significantly higher FD mRNA levels were noted in cSCC tumors than in normal skin. Strong tumor cell-associated FD immunolabeling was detected in the invasive margin of human cSCC xenografts. More intense tumor cell-specific immunostaining for FD was seen in the tumor edge in primary and metastatic cSCCs, in metastases, and in recessive dystrophic epidermolysis bullosa-associated cSCCs, compared with cSCC in situ, actinic keratosis and normal skin. FD production by cSCC cells was dependent on p38 mitogen-activated protein kinase activity, and it was induced by interferon-γ and interleukin-1β. Blocking FD activity by Danicopan inhibited activation of extracellular signal-regulated kinase 1/2 and attenuated proliferation of cSCC cells. These results identify FD as a novel putative biomarker and therapeutic target for cSCC progression.
Project description:BackgroundGastric cancer (GC) is one of the most prevalent cancer types that reduce human life expectancy. The current tumor-node-metastasis (TNM) staging system is inadequate in identifying higher or lower risk of GC patients because of tumor heterogeneity. Research shows that complement plays a dual role in the tumor development and progression of GC.MethodsWe downloaded GC data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). A complement-related risk signature was constructed through bioinformatics analysis. Subsequently, the predictive ability of this signature was validated with GSE84437 dataset, and a nomogram integrating risk score and common clinical factors was established. Besides, we evaluated the association of risk score with the immune and stromal cell infiltration in TCGA. Furthermore, immunotherapy response prediction and drug susceptibility analysis were conducted to access the ability of the risk signature in predicting the therapeutic effect.ResultsA complement-related gene (CRG) signature, based on six genes (SPLG, C9, ITIH1, ZFPM2, CD36, and SERPINE1), was established. In both the training and validation sets, the overall survival of GC patients in the high-risk group was lower than that of the low-risk group, and the nomogram to predict the 1-, 2-, and 3-year survival rates of GC patients was developed. In addition, CIBERSORT algorithm showed the high-risk patients had higher levels of immune cell infiltration than low-risk patients, and the ESTIMATE results implied that the high-risk group had more stromal component in tumor microenvironment. Besides, compared to the low-risk group, there were higher expressions of most immune checkpoint genes and HLA genes in the high-risk group, and the high-risk patients showed higher sensitivity to the chemotherapy and targeted drugs (axitinib, dasatinib, pazopanib, saracatinib, sunitinib and temsirolimus).ConclusionsThe novel CRG signature may act as a reliable, efficient tool for prognostic prediction and treatment guidance in future clinical practice.
Project description:From detailed assessments of electronic structure, we find that a combination of significantly quantal elements, six of seven atoms being hydrogen, becomes a stable metal at a pressure approximately 1/4 of that required to metalize pure hydrogen itself. The system, LiH(6) (and other LiH(n)), may well have extensions beyond the constituent lithium. These hypothetical materials demonstrate that nontraditional stoichiometries can considerably expand the view of chemical combination under moderate pressure.
Project description:BackgroundIn the absence of sex and recombination, genomes are expected to accumulate deleterious mutations via an irreversible process known as Muller's ratchet, especially in the case of polyploidy. In contrast, no genome-wide mutation accumulation was detected in a transcriptome of facultative apomictic, hexaploid plants of the Ranunculus auricomus complex. We hypothesize that mutations cannot accumulate in flowering plants with facultative sexuality because sexual and asexual development concurrently occurs within the same generation. We assume a strong effect of purging selection on reduced gametophytes in the sexual developmental pathway because previously masked recessive deleterious mutations would be exposed to selection.ResultsWe test this hypothesis by modeling mutation elimination using apomictic hexaploid plants of the R. auricomus complex. To estimate mean recombination rates, the mean number of recombinants per generation was calculated by genotyping three F1 progeny arrays with six microsatellite markers and character incompatibility analyses. We estimated the strength of purging selection in gametophytes by calculating abortion rates of sexual versus apomictic development at the female gametophyte, seed and offspring stage. Accordingly, we applied three selection coefficients by considering effects of purging selection against mutations on (1) male and female gametophytes in the sexual pathway (additive, s = 1.000), (2) female gametophytes only (s = 0.520), and (3) on adult plants only (sporophytes, s = 0.212). We implemented recombination rates into a mathematical model considering the three different selection coefficients, and a genomic mutation rate calculated from genome size of our plants and plant-specific mutation rates. We revealed a mean of 6.05% recombinants per generation. This recombination rate eliminates mutations after 138, 204 or 246 generations, depending on the respective selection coefficients (s = 1.000, 0.520, and 0.212).ConclusionsOur results confirm that the empirically observed frequencies of facultative recombination suffice to prevent accumulation of deleterious mutations via Muller's ratchet even in a polyploid genome. The efficiency of selection is in flowering plants strongly increased by acting on the haplontic (reduced) gametophyte stage.
Project description:Liver cancer is the sixth most common cancer and the fourth most fatal cancer in the world. Immunotherapy has already achieved modest results in the treatment of liver cancer. Meanwhile, the novel and optimal combinatorial strategies need further research. The complement system, which consists of mediators, receptors, cofactors and regulators, acts as the connection between innate and adaptive immunity. Recent studies demonstrate that complement system can influence tumor progression by regulating the tumor microenvironment, tumor cells, and cancer stem cells in liver cancer. Our review concentrates on the potential role of the complement system in cancer treatment, which is a promising strategy for killing tumor cells by the activation of complement components. Conclusions: Our review demonstrates that complement components and regulators might function as biomarkers and therapeutic targets for liver cancer diagnosis and treatment.