MicroRNA-221-5p Promotes Ricin Toxin-induced Inflammation via PI3K/Akt signaling pathway by targeting COL4a5.

Ricin toxin (RT) is one of the most lethal type II ribosome-inactivating proteins (RIP), and is classified as a potential bioterror agent due to its severe cytotoxicity and high availability. The toxicity of RT is dependent on both dose and route of exposure. Increasing evidence demonstrates that sub-lethal RT induces acute inflammation and increases the release of pro-inflammatory cytokines. However, current studies on mechanism of RT-induced inflammation are limited. In this study, to evaluate the relationship between miRNAs and RT-induced inflammation, RNA sequencing (RNA-Seq) was used to analyze the expression of miRNAs and mRNAs in RT-treated RAW264.7 macrophage cells. A total of 14 significantly differently expressed (DE) miRNAs and 323 miRNA-mRNA interaction pairs were predicted by bioinformatics analysis. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed that majority of those interaction pairs were involved in PI3K/Akt pathway. In addition, overexpression of miR-221-5p promoted the inflammatory response by inhibiting the mRNA expression of COL4a5. This work contributes to our understanding of RT-induced inflammation and demonstrates the potential role of miRNAs in innate immunity, which may be regarded as potential targets in developing therapies for RT poisoning.

The COL-4A1 polypeptide destroy endothelial cells through the TGF-ß/PI3K/AKT pathway.

Preeclampsia (PE) is commonly considered as a placental disorder in pregnancy. Until now, the etiology and pathological mechanism of PE have remained ambiguous. Although PE can lead to a variety of maternal and infant complications, there are still no effective treatments. This study aimed to explore the correlation between the novel polypeptide COL-4A1 and PE, and to identify the underlying mechanism by which this polypeptide may function and to explore new therapeutic targets for PE. A rat model of PE was established and used to verify the function of the polypeptide COL-4A1 in vivo. Additionally, human umbilical vascular endothelial cells (HUVECs) were cultured with or without COL-4A1 and TNF-α (20 ng/ml). Cell Counting Kit-8 (CCK-8), wound-healing, Transwell and tube formation assays were used to evaluate cell proliferation, migration and angiopoiesis. RNA sequencing and mass spectrometry were conducted to explore the underlying downstream mechanism of COL-4A1. In vivo, COL-4A1 increased blood pressure and elevated the risk of fetal growth restriction (FGR) which was induced by lipopolysaccharide (LPS) in the rat model. In vitro, COL-4A1 significantly inhibited the proliferation and migration of HUVECs. After culture with COL-4A1, compared to control group the adhesive ability and level of reactive oxygen species (ROS) were enhanced and tube formation ability was decreased. Furthermore, Western blotting (WB) and pull-down assays were conducted to explore the underlying mechanism by which COL-4A1 functions, and the TGF-ß/PI3K/AKT pathway was identified as the potential pathway involved in its effects. In summary, these results revealed that the polypeptide COL-4A1 caused PE-like symptoms in cells and a rat model. Through the TGF-ß/PI3K/AKT pathway, COL-4A1 interferes with the pathogenesis of PE. Thus COL-4A1 is expected to become a potential target of PE, providing a basis for exploring the treatment of PE.

Glomerulopathy induced by immunization with a peptide derived from the goodpasture antigen α3IV-NC1.

Mouse experimental autoimmune glomerulonephritis, a model of human antiglomerular basement membrane disease, depends on both Ab and T cell responses to the Goodpasture Ag noncollagenous domain 1 of the α3-chain of type IV collagen (α3IV-NC1). The aim of our study was to further characterize the T cell-mediated immune response. Repeated immunization with mouse α3IV-NC1 caused fatal glomerulonephritis in DBA/1 mice. Although two immunizations were sufficient to generate high α3IV-NC1-specific IgG titers, Ab and complement deposition along the glomerular basement membranes, and a nephrotic syndrome, two additional immunizations were needed to induce a necrotizing/crescentic glomerulonephritis. Ten days after the first immunization, α3IV-NC1-specific CD4(+) cells producing TNF-α, IFN-γ, or IL-17A were detected in the spleen. With the emergence of necrotizing/crescentic glomerulonephritis, ∼0.15% of renal CD4(+) cells were specific for α3IV-NC1. Using peptides spanning the whole α3IV-NC1 domain, three immunodominant T cell epitopes were identified. Immunization with these peptides did not lead to clinical signs of experimental autoimmune glomerulonephritis or necrotizing/crescentic glomerulonephritis. However, mice immunized with one of the peptides (STVKAGDLEKIISRC) developed circulating Abs against mouse α3IV-NC1 first detected at 8 wk, and 50% of the mice showed mild proteinuria at 18-24 wk due to membranous glomerulopathy. Taken together, our results suggest that autoreactive T cells are able to induce the formation of pathologic autoantibodies. The quality and quantity of α3IV-NC1-specific Ab and T cell responses are critical for the phenotype of the glomerulonephritis.

Lithium pretreatment reduces brain injury after intracerebral hemorrhage in rats.

OBJECTIVE: In addition to the mood-stabilizing effects of lithium in patients with bipolar disorder, recent in vitro and in vivo studies in rodents increasingly implicate that lithium may be useful for treating acute cerebral ischemia, neuroinflammatory conditions, and chronic neurodegenerative diseases. However, whether lithium has a protective effect against hemorrhagic stroke is yet unknown. To test this possibility, we attempted to determine lithium's effect on experimental intracerebral hemorrhage (ICH). METHODS: We treated adult rats with either lithium (2 mEq/kg) or saline for 3 days before inducing ICH via a stereotaxic infusion of collagenase into the left basal ganglia. Hematoma volumes, hemispheric swelling, long-term hemispheric atrophy, microglial activation, cell death, cyclooxygenase-2 expression, and behavioral outcomes were assessed. RESULTS: Per behavioral tests 2 days after ICH, the lithium-treated group recovered better than did the saline-treated group. Three days after ICH, the hematoma volumes did not differ between the groups, but hemispheric swelling was less in the lithium-treated group. Forty-two days after ICH, hemispheric atrophy was less in the lithium-treated group. Lithium reduced cell death, cyclooxygenase-2 expression, and reactive microglia in the perihematomal regions. CONCLUSION: The present study shows that lithium, via anti-inflammation, reduces the perihematomal cell death, which is associated with sensorimotor recovery after experimental ICH.

Murine membranous nephropathy: immunization with α3(IV) collagen fragment induces subepithelial immune complexes and FcγR-independent nephrotic syndrome.

Membranous nephropathy (MN) is a leading cause of nephrotic syndrome in adults and a significant cause of end-stage renal disease, yet current therapies are nonspecific, toxic, and often ineffective. The development of novel targeted therapies requires a detailed understanding of the pathogenic mechanisms, but progress is hampered by the lack of a robust mouse model of disease. We report that DBA/1 mice as well as congenic FcγRIII(-/-) and FcRγ(-/-) mice immunized with a fragment of α3(IV) collagen developed massive albuminuria and nephrotic syndrome, because of subepithelial deposits of mouse IgG and C3 with corresponding basement membrane reaction and podocyte foot process effacement. The clinical presentation and histopathologic findings were characteristic of MN. Although immunized mice produced genuine anti-α3NC1 autoantibodies that bound to kidney and lung basement membranes, neither crescentic glomerulonephritis nor alveolitis ensued, likely because of the predominance of mouse IgG1 over IgG2a and IgG2b autoantibodies. The ablation of activating IgG Fc receptors did not ameliorate injury, implicating subepithelial deposition of immune complexes and consequent complement activation as a major effector pathway. We have thus established an active model of murine MN. This model, leveraged by the availability of genetically engineered mice and mouse-specific reagents, will be instrumental in studying the pathogenesis of MN and evaluating the efficacy of novel experimental therapies.