Anti-inflammatory cerium-containing nano-scaled mesoporous bioactive glass for promoting regenerative capability of dental pulp cells.

AIMS: This study aimed to investigate the anti-inflammatory and odontoblastic effects of cerium-containing mesoporous bioactive glass nanoparticles (Ce-MBGNs) on dental pulp cells as novel pulp-capping agents. METHODOLOGY: Ce-MBGNs were synthesized using a post-impregnation strategy based on the antioxidant properties of Ce ions and proposed the first use of Ce-MBGNs for pulp-capping application. The biocompatibility of Ce-MBGNs was analysed using the CCK-8 assay and apoptosis detection. Additionally, the reactive oxygen species (ROS) scavenging ability of Ce-MBGNs was measured using the 2,7-Dichlorofuorescin Diacetate (DCFH-DA) probe. The anti-inflammatory effect of Ce-MBGNs on THP-1 cells was further investigated using flow cytometry and quantitative real-time polymerase chain reaction (RT-qPCR). Moreover, the effect of Ce-MBGNs on the odontoblastic differentiation of the dental pulp cells (DPCs) was assessed by combined scratch assays, RT-qPCR, western blotting, immunocytochemistry, Alizarin Red S staining and tissue-nonspecific alkaline phosphatase staining. Analytically, the secretions of tumour necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß) were detected with enzyme-linked immunosorbent assay (ELISA). RESULTS: Ce-MBGNs were confirmed to effectively scavenge ROS in THP-1-derived macrophages and DPCs. Flow cytometry and RT-qPCR assays revealed that Ce-MBGNs significantly inhibited the M1 polarization of macrophages (Mφ). Furthermore, the protein levels of TNF-α and IL-1ß were downregulated in THP-1-derived macrophages after stimulation with Ce-MBGNs. With a step-forward virtue of promoting the odontoblastic differentiation of DPCs, we further confirmed that Ce-MBGNs could regulate the formation of a conductive immune microenvironment with respect to tissue repair in DPCs, which was mediated by macrophages. CONCLUSIONS: Ce-MBGNs protected cells from self-produced oxidative damage and exhibited excellent immunomodulatory and odontoblastic differentiation effects on DPCs. As a pulp-capping agent, this novel biomaterial can exert anti-inflammatory effects and promote restorative dentine regeneration in clinical treatment. We believe that this study will stimulate further correlative research on the development of advanced pulp-capping agents.

Targeting JMJD1C to selectively disrupt tumor Treg cell fitness enhances antitumor immunity.

Regulatory T (Treg) cells are critical for immune tolerance but also form a barrier to antitumor immunity. As therapeutic strategies involving Treg cell depletion are limited by concurrent autoimmune disorders, identification of intratumoral Treg cell-specific regulatory mechanisms is needed for selective targeting. Epigenetic modulators can be targeted with small compounds, but intratumoral Treg cell-specific epigenetic regulators have been unexplored. Here, we show that JMJD1C, a histone demethylase upregulated by cytokines in the tumor microenvironment, is essential for tumor Treg cell fitness but dispensable for systemic immune homeostasis. JMJD1C deletion enhanced AKT signals in a manner dependent on histone H3 lysine 9 dimethylation (H3K9me2) demethylase and STAT3 signals independently of H3K9me2 demethylase, leading to robust interferon-γ production and tumor Treg cell fragility. We have also developed an oral JMJD1C inhibitor that suppresses tumor growth by targeting intratumoral Treg cells. Overall, this study identifies JMJD1C as an epigenetic hub that can integrate signals to establish tumor Treg cell fitness, and we present a specific JMJD1C inhibitor that can target tumor Treg cells without affecting systemic immune homeostasis.

Histone methyltransferase Nsd2 is required for follicular helper T cell differentiation.

Follicular helper T (Tfh) cells provide essential help for humoral immune response. Transcriptional factor Bcl6 is the master regulator for Tfh generation and is induced very early after T cell activation in a CD28-dependent manner, but how CD28 signal promotes Bcl6 early expression remains unknown. Here we found that CD28 signal quickly induces expression of the H3K36me2 methytransferase Nsd2, which is required for Bcl6 expression as early as the first cell division after T cell activation. Nsd2 deficiency in T cells leads to decreased Bcl6 expression, impaired Tfh generation, compromised germinal center response, and delayed virus clearance. Ectopic Bcl6 expression rescues the Tfh defect of Nsd2 KO cells. ICOS signal is dispensable for early Nsd2 induction but required for sustained Nsd2 expression, which is critical for Tfh maintenance. Overexpression of Nsd2 increases Bcl6 expression and enhances Tfh generation; 4-mo-old mice even develop spontaneous Tfh. Overall, our study reveals Nsd2 as a critical epigenetic regulator for Tfh differentiation.

C5a Induces the Synthesis of IL-6 and TNF-α in Rat Glomerular Mesangial Cells through MAPK Signaling Pathways.

Inflammatory response has been reported to contribute to the renal lesions in rat Thy-1 nephritis (Thy-1N) as an animal model of human mesangioproliferative glomerulonephritis (MsPGN). Besides C5b-9 complex, C5a is also a potent pro-inflammatory mediator and correlated to severity of various nephritic diseases. However, the role of C5a in mediating pro-inflammatory cytokine production in rats with Thy-1N is poorly defined. In the present studies, the levels of C5a, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were first determined in the renal tissues of rats with Thy-1N. Then, the expression of IL-6 and TNF-α was detected in rat glomerular mesangial cells (GMC) stimulated with our recombinant rat C5a in vitro. Subsequently, the activation of mitogen-activated protein kinase (MAPK) signaling pathways (p38 MAPK, ERK1/2 and JNK) and their roles in the regulation of IL-6 and TNF-α production were examined in the GMC induced by C5a. The results showed that the levels of C5a, IL-6 and TNF-α were markedly increased in the renal tissues of Thy-1N rats. Rat C5a stimulation in vitro could up-regulate the expression of IL-6 and TNF-α in rat GMC, and the activation of MAPK signaling pathways was involved in the induction of IL-6 and TNF-α. Mechanically, p38 MAPK activation promoted IL-6 production, while either ERK1/2 or JNK activation promoted TNF-α production in the GMC with exposure to C5a. Taken together, these data implicate that C5a induces the synthesis of IL-6 and TNF-α in rat GMC through the activation of MAPK signaling pathways.

Interleukin-17 (IL-17)-induced microRNA 873 (miR-873) contributes to the pathogenesis of experimental autoimmune encephalomyelitis by targeting A20 ubiquitin-editing enzyme.

Interleukin 17 (IL-17), produced mainly by T helper 17 (Th17) cells, is increasingly recognized as a key regulator in various autoimmune diseases, including human multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Although several microRNAs (miRNAs) with aberrant expression have been shown to contribute to the pathogenesis of MS and EAE, the mechanisms underlying the regulation of abnormal miRNA expression in astrocytes upon IL-17 stimulation remain unclear. In the present study, we detected the changes of miRNA expression profiles both in the brain tissue of EAE mice and in cultured mouse primary astrocytes stimulated with IL-17 and identified miR-873 as one of the co-up-regulated miRNAs in vivo and in vitro. The overexpression of miR-873, demonstrated by targeting A20 (TNFα-induced protein 3, TNFAIP3), remarkably reduced the A20 level and promoted NF-κB activation in vivo and in vitro as well as increasing the production of inflammatory cytokines and chemokines (i.e. IL-6, TNF-α, MIP-2, and MCP-1/5). More importantly, silencing the endogenous miR-873 or A20 gene with lentiviral vector of miR-873 sponge (LV-miR-873 sponge) or short hairpin RNA (shRNA) of A20 (LV-A20 shRNA) in vivo significantly lessened or aggravated inflammation and demyelination in the central nervous system (CNS) of EAE mice, respectively. Taken together, these findings indicate that miR-873 induced by IL-17 stimulation promotes the production of inflammatory cytokines and aggravates the pathological process of EAE mice through the A20/NF-κB pathway, which provides a new insight into the mechanism of inflammatory damage in MS.

Sublytic C5b-9 induces IL-6 and TGF-ß1 production by glomerular mesangial cells in rat Thy-1 nephritis through p300-mediated C/EBPß acetylation.

CCAAT/enhancer-binding protein (C/EBPß)-enhanced IL-6 and TGF-ß1 promoter activity and p300-mediated C/EBPß acetylation were involved in up-regulation of IL-6 and TGF-ß1 expression in GMCs attacked by sublytic C5b-9. In detail, the elements of C/EBPß binding to rat IL-6 and TGF-ß1 promoter and 3 acetylated sites of rat C/EBPß protein were first revealed. Furthermore, silencing the p300 or C/EBPß gene in rat kidney significantly reduced the production of IL-6 and TGF-ß1 and renal lesions in Thy-1N rats. Together, these data indicate that the mechanism of IL-6 and TGF-ß1 production in renal tissue of Thy-1N rats is associated with sublytic C5b-9 up-regulated p300 and p300-mediated C/EBPß acetylation as well as C/EBPß-activated IL-6 and TGF-ß1 genes.

Generation of human neutralizing monoclonal antibodies against the 2009 pandemic H1N1 virus from peripheral blood memory B lymphocytes.

The 2009 H1N1 influenza pandemic demonstrated the significance of a global health threat to human beings. Although pandemic H1N1 vaccines have been rapidly developed, passive serotherapy may offer superior immediate protection against infections in children, the elderly and immune-compromised patients during an influenza pandemic. Here, we applied a novel strategy based on Epstein-Barr virus (EBV)-immortalized peripheral blood memory B cells to screen high viral neutralizing monoclonal antibodies (MAbs) from individuals vaccinated with the 2009 pandemic H1N1 vaccine PANFLU.1. Through a massive screen of 13 090 immortalized memory B-cell clones from three selected vaccinees, seven MAbs were identified with both high viral neutralizing capacities and hemagglutination inhibition (HAI) activities against the 2009 pandemic H1N1 viruses. These MAbs may have important clinical implications for passive serotherapy treatments of infected patients with severe respiratory syndrome, especially children, the elderly and immunodeficient individuals. Our successful strategy for generating high-affinity MAbs from EBV-immortalized peripheral blood memory B cells may also be applicable to other infectious or autoimmune diseases.