•Antibiotics induced gut microbiota dysbiosis promotes tumor initiation in mice.•Gut microbiota disruption compromise APC-Th1 development in tumor.•Orally LPS administration rescues tumor immune surveillance in gut microbiota disrupted mice.•None of the authors have any conflict of interest.Gut microbiota is critical for maintaining body immune homeostasis and thus affects tumor growth and therapeutic efficiency. Here, we investigated the link between microbiota and tumorgenesis in a mice model of subcutaneous melanoma cell transplantation, and explored the underlying mechanism. We found disruption of gut microbiota by pretreating mice with antibiotics promote tumor growth and remodeling the immune compartment within the primary tumor. Indeed, gut microbial dysbiosis reduced the infiltrated mature antigen-presenting cells of tumor, together with lower levels of co-stimulators, such as CD80, CD86 and MHCII, as well as defective Th1 cytokines, including IFNγ, TNFα, IL12p40, and IL12p35. Meantime, splenic APCs displayed blunted ability in triggering T cell proliferation and IFNγ secretion. However, oral administration of LPS restored the immune surveillance effects and thus inhibited tumor growth in the antibiotics induced gut microbiota dysbiosis group. Taken together, these data highly supported that antibiotics induced gut microbiota dysbiosis promotes tumor initiation, while LPS supplementation would restore the effective immune surveillance and repress tumor initiation.

Sepsis is a life-threatening disease characterized by uncontrolled inflammatory responses upon pathogen infections, especially for the antibiotic-resistant strains, such as Methicillin-resistant S. aureus (MRSA). Here we demonstrated that a Mitochondria-derived peptide (MOTS-c) could significantly improve the survival rate and decrease bacteria loads in MRSA-challenged mice, accompanied with declined levels of pro-inflammatory cytokines, such as TNF-α, IL-6 and IL-1β, but with increased level of anti-inflammatory cytokine IL-10. Moreover this peptide enhanced bactericidal capacity of macrophages. Meanwhile, MOTS-c inhibited the phosphorylation mitogen-activated protein kinases (MAPK), and enhanced the expression of aryl hydrocarbon receptor (AhR) and signal transducer and activator of transcriptional 3 (STAT3) in macrophages. Overall, MOTS-c plays a beneficial role in curbing the overwhelming inflammatory bursts in the fight against MRSA infection. It may serve as a potential therapeutic agent in sepsis treatment.Highlight•MOTS-c improved survival status in mice during MRSA infection.•MOTS-c strongly enhanced bactericidal capacity of macrophages.•MOTS-c exerted an anti-inflammatory effect via suppressing MAPKs and increasing Ahr/STAT3 signaling pathways.

Activated macrophages exhibiting diverse phenotypes and various functions contribute to the pathogenesis or amelioration of different diseases like cancer, inflammation, and infectious and autoimmune diseases. However, the mechanisms of macrophage polarization in inflamed joint and its effects on rheumatoid arthritis (RA) are still not clarified. This study is designed to explore the effects of cyclophilin A (CypA) on macrophage polarization and describe the underlying mechanisms. Collagen-induced arthritis (CIA) was employed to address the pro-arthritic effects of CypA. Flow cytometry was performed to investigate the populations of M1 and M2 macrophages in synovial tissues of the mice. Knockdown or overexpression of CypA macrophage cells was used to study the functions of CypA on macrophage polarization. Western blot was carried out to examine the potential signaling pathways. We found that CypA aggravated the severity of CIA in mice, as assessed by the increase of clinical score of inflammation, cartilage damage, and bone erosion. Moreover, the level of cytokines, such as IL-6, IL-1β, and IL-17, and the number of pro-inflammatory macrophages in synovial fluid were significantly elevated. In accordance with our observation, CypA dysregulation could actually influence the M1 macrophages polarization and pro-inflammatory cytokines production. Further mechanism study disclosed that CypA could regulate the transcriptional activity of NF-κB, the pivotal transcriptional factor regulating M1 polarization, dependent of its PPIase activity. Our findings provide evidence that PPIase CypA promoted macrophages polarization toward pro-inflammatory M1 phenotype via transcriptional activating NF-κB, thus leading to aggravated arthritis.

•We developed an aptamer-based immunoassay to detection MC-LR.•The specificity was promoted by this aptamer-MC-LR-antibody sandwich method.•A portable analyzer was used to test the chemiluminescence signals catalyzed by HRP.•It proved a simple quantitative method to detect MC-LR in the field by a single analyst.The rapid detection of microcystin-leucine-arginine (MC-LR), the most highly toxic among MCs, is significantly important to environmental and human health protection and prevention of MC-LR from being used as a bioweapon. Although aptamers offer higher affinity, specificity, and stability with MC-LR than antibodies in the immunodetection of MC-LR due to steric hindrance between two antibodies and limited epitopes of MC-LR for use in a sandwich immunoassay, no sandwich immunoassay using an aptmer has been developed for MC-LR detection. This study is aimed at developing an aptamer-antibody immunoassay (AAIA) to detect MC-LR using a portable analyzer. The aptamers were immobilized onto the glass surface of a microchamber to capture MC-LR. MC-LR and horseradish peroxidase (HRP)-labeled antibody were pulled into the microchamber to react with the immobilized aptamer. The chemiluminescence (CL) catalyzed by HRP was tested by a photodiode-based portable analyzer. MC-LR at 0.5–4.0 μg/L was detected quantitatively by the AAIA, with a CL signal sensitivity of 0.3 μg/L. The assay took less than 35 min for a single sample and demonstrated a high specificity, detecting only MC-LR, but not MC-LA, MC-YR, or nodularin-R. The recovery of two spiked real environmental samples calculated as 94.5–112.7%. Therefore, this AAIA was proved to be a rapid and simple method to detect MC-LR in the field by a single analyst.

RNA interference is an appealing and promising therapeutic approach in cancer and other diseases. Designing novel strategies aiming to increase the efficiency, duration, and reduce the off-target silencing by sense strand is of great significance for its future application clinically. Here, we report that RNA duplex with the sense strand pre-cleaved at the base between base 10 and 11 relative to the 5′ end of the antisense strand induced a target-specific RNA silencing effectively. Furthermore, different from the canonical RNA duplex, this novel RNA duplex rarely inhibits the luciferase activity in the reporter, bearing the target sequence corresponding to the sense strand, suggesting a less off-target effects of this novel strategy. Furthermore, the immune response of the novel RNA duplex induced a much milder immune response as seen from the NFkappaB activity. In addition, our newly designed RNA duplex should be easier for preservation than the asymmetric RNA duplex. Our results establish a novel method to design a new class of RNA duplex for improved RNA interference.

RNA-binding protein QKI, a member of the Signal Transduction and Activation of RNA family, is found to be essential in the blood vessel development and postnatal myelination in central nervous system (Woo et al., Oncogene 28:1176–1186, 2009; Lu et al., Nucleic Acids Res 31(15):4616–4624, 2003; Bohnsack et al., Genesis 44(2):93–104, 2006). However, its wide expression pattern suggests other fundamental roles in vivo (Kondo et al., Mamm Genome 10(7):662–669, 1999). To facilitate the understanding of QKI function in various systems, we prepared the polyclonal and monoclonal antibodies against QKI. To obtain the antigen, recombinant His-tagged QKI was expressed in Escherichia coli and highly purified by Ni2+-chelated column combined with hydrophobic and ion exchange methods. Following three types of immunizations with different adjuvants, including Freund’s, PAGE gel, and nitrocellulose membrane, only the antiserum produced with Freund’s adjuvant is effective for Western blot detection. Several McAb clones are able to recognize both endogenous and over-expressed QKI with high affinity in Western blot and immunofluorescence. The specificity of Ab was validated as weakening, and no specific signals were observed in cells with QKI knocking down. Immunohistochemistry analysis further showed positive staining of QKI in kidney where QKI mRNA was abundantly expressed, ensuring the wide applications of the QKI Abs in the ongoing mechanistic studies.

•Hyperglycemia promoted the development of CNV in diabetic mice.•Insulin could inhibit the severity of CNV induced by hyperglycemia.•Hyperglycemia promoted recruitment and incorporation of BMCs.•Hyperglycemia affected differentiation of BMCs in CNV.•Hyperglycemia enhanced the expression of VEGF and SDF-1 in RPE cells.To investigate the influence of hyperglycemia on the severity of choroidal neovascularization (CNV) in diabetic mice, especially the involvement of bone marrow-derived cells (BMCs) and underlying molecular mechanisms. The mice were randomly divided into control group, diabetes group and diabetes treated with insulin group, which were laser treated to induce CNV. The CNV severity was evaluated by fundus fluorescein angiography, HE staining and choroidal flatmount. The BMCs recruitment and differentiation in CNV were examined in GFP chimeric mice by choroidal flatmount and immunofluorescence. The bone marrow-derived mesenchymal stem cells (BMSCs) recruitment and migration were tested in vivo and in vitro. VEGF and SDF-1 production in vivo and in vitro were tested by realtime PCR and ELISA. The CNV severity and expression of VEGF and SDF-1 were enhanced in DM mice compared with control mice and that insulin treatment decreased CNV severity in DM mice. The DM mice demonstrated more BMCs and bone marrow-derived mesenchymal stem cells (BMSCs) recruited and incorporated into CNV, increased ratio of BMCs expressing endothelial cell marker or macrophage marker, and up-regulated expression of VEGF and SDF-1 in CNV. Human BMSCs migration and expression of VEGF and SDF-1 in retinal pigment epithelial (RPE) cells increased when cultured under high glucose. This study suggested that hyperglycemia enhanced the expression of VEGF and SDF-1 in RPE cells, and promoted recruitment and incorporation of BMCs and affected differentiation of BMCs in CNV, which led to more severe CNV in diabetic mice.Download high-res image (240KB)Download full-size image