BATF2 enhances proinflammatory cytokine responses in macrophages and improves early host defense against pulmonary Klebsiella pneumoniae infection.

Basic leucine zipper transcription factor ATF-like 2 (BATF2) is a transcription factor that is emerging as an important regulator of the innate immune system. BATF2 is among the top upregulated genes in human alveolar macrophages treated with LPS, but the signaling pathways that induce BATF2 expression in response to Gram-negative stimuli are incompletely understood. In addition, the role of BATF2 in the host response to pulmonary infection with a Gram-negative pathogen like Klebsiella pneumoniae (Kp) is not known. We show that induction of Batf2 gene expression in macrophages in response to Kp in vitro requires TRIF and type I interferon (IFN) signaling, but not MyD88 signaling. Analysis of the impact of BATF2 deficiency on macrophage effector functions in vitro showed that BATF2 does not directly impact macrophage phagocytic uptake and intracellular killing of Kp. However, BATF2 markedly enhanced macrophage proinflammatory gene expression and Kp-induced cytokine responses. In vivo, Batf2 gene expression was elevated in lung tissue of wild-type (WT) mice 24 h after pulmonary Kp infection, and Kp-infected BATF2-deficient (Batf2-/-) mice displayed an increase in bacterial burden in the lung, spleen, and liver compared with WT mice. WT and Batf2-/- mice showed similar recruitment of leukocytes following infection, but in line with in vitro observations, proinflammatory cytokine levels in the alveolar space were reduced in Batf2-/- mice. Altogether, these results suggest that BATF2 enhances proinflammatory cytokine responses in macrophages in response to Kp and contributes to the early host defense against pulmonary Kp infection.NEW & NOTEWORTHY This study investigates the signaling pathways that mediate induction of BATF2 expression downstream of TLR4 and also the impact of BATF2 on the host defense against pulmonary Kp infection. We demonstrate that Kp-induced upregulation of BATF2 in macrophages requires TRIF and type I IFN signaling. We also show that BATF2 enhances Kp-induced macrophage cytokine responses and that BATF2 contributes to the early host defense against pulmonary Kp infection.

[Association of MDR1 gene polymorphisms with refractory epilepsy in children].

OBJECTIVE: To assess the association of single nucleotide polymorphisms of multidrug resistance gene 1 (MDR1) with refractory epilepsy in children. METHODS: Peripheral blood samples were collected from 200 children with epilepsy and 100 healthy controls. Genomic DNA was extracted and subjected to PCR amplification, agarose gel electrophoresis and target site sequencing. Genotypes of rs1922242, rs2235048, rs10808072, rs868755 and rs1202184 loci of the MDR1 gene were analyzed. RESULTS: No significant difference was found in genotypic distribution and allelic frequencies of the rs1922242, rs2235048, rs10808072 and rs868755 loci between the drug-resistant and drug-sensitive groups. For the rs1202184 locus, a significant difference in genotypic distribution was found (P=0.008). No significant difference was found in the frequencies of various haplotypes between the two groups. CONCLUSION: Genotypes of the rs1202184 locus of the MDR1 gene are associated with refractory epilepsy in children, for which the AA genotype plays a dominant role.

mTOR regulates NLRP3 inflammasome activation via reactive oxygen species in murine lupus.

Inflammasomes are protein complexes responsible for the release of IL-1 family cytokines, and they play critical roles in immunity and inflammation. The best-characterized inflammasome, the NOD-like receptor protein 3 (NLRP3) inflammasome, is involved in the development of multiple autoimmune diseases. However, the underlying mechanisms of abnormal NLRP3 inflammasome activation in systemic lupus erythematosus (SLE) remain elusive. Here, western blot analysis was used to detect the level of NLRP3 components and mTORC1/2 substrate in the kidney tissues from B6.MRL-FASlpr/J lupus mice and C57BL/6 mice, and the results showed that mammalian target of rapamycin (mTOR) complex 1/2 (mTORC1/2) and the NLRP3 inflammasome were hyperactivated in B6.MRL-FASlpr/J lupus mice. The inhibition of mTOR by INK128, a novel mTORC1/2 inhibitor, suppressed LPS/ATP and LPS/nigericin-induced NLRP3 inflammasome activation in bone marrow-derived macrophages (BMDMs) in vitro. INK128 decreased both the mRNA and protein levels of NLRP3 in an NF-κB-independent manner. Moreover, we reported for the first time that the inhibition of mTOR suppressed mitochondrial reactive oxygen species (ROS) production in BMDMs stimulated by an NLRP3 agonist. Furthermore, N-acetyl-L-cysteine, a ROS inhibitor, decreased NLRP3 expression, and rotenone, a robust ROS inducer, partially reversed the inhibitory effect of INK128 on NLRP3. These results demonstrated that mTOR regulated the activation of the NLRP3 inflammasome at least partially via ROS-induced NLRP3 expression. Importantly, in vivo data demonstrated that INK128 treatment prominently attenuated lupus nephritis and suppressed NLRP3 inflammasome activation in B6.MRL-FASlpr/J lupus mice. Taken together, our results suggest that activation of mTOR/ROS/NLRP3 signaling may contribute to the development of SLE.

Decreased CD1d level is associated with CD86 over-expression in B cells from systemic lupus erythematosus.

The disorder of B cells is one of the hallmarks of systemic lupus erythematosus (SLE). The activation state indicated by CD86 of B cells from SLE is well known, while the defect of regulatory B cells mediated by CD1d is also responsible for the process of SLE. In the present study, we focused on the relationship between B cell activation mediated by CD86 and B cell regulatory function mediated by CD1d. Our results showed that the level of CD1d in B cells was decreased during the early stages of B6.MRLlpr SLE mice and imiquimod-treated (IMQ-treated) mice, while the level of CD86 was significantly increased at the late stage. Moreover, the expression of CD1d showed a significantly negative correlation with CD86 level in B cells from IMQ-treated mice (r = -05741; P = 0.0022), B6.MRLlpr mice (r = -0.7091; P = 0.0268), and SLE patients (r = -0.4125; P = 0.0404). The in vivo and in vitro experiments with splenocytes demonstrated that CD1d signaling pathway could inhibit toll-like receptor 7 (TLR7)-induced CD86 expression of B cells. Further studies showed that this relationship also affected antibody production. Thus, our results confirmed the association of CD1d and CD86 levels in B cells from SLE, and demonstrated the importance to preserve the immunoregulatory function of B cells mediated by CD1d in the progression of SLE.

17ß-Estradiol enhances the activation of IFN-α signaling in B cells by down-regulating the expression of let-7e-5p, miR-98-5p and miR-145a-5p that target IKKε.

The activation of IFN-α signaling in B cells contributes to the pathogenesis of systemic lupus erythematosus (SLE). Many studies suggest that estrogens are closely related to the gender difference in the prevalence of SLE. However, the underlying mechanism of the interaction between estrogens and the activation of IFN-α signaling in SLE B cells remains incompletely understood. In the present study, we first found that healthy female mice showed an up-regulated type I IFN-induced gene signature in B cells compared with age-matched male mice, and an in vivo study revealed that the gender difference was related to 17ß-estradiol. Moreover, we found that 17ß-estradiol could enhance the activation of IFN-α signaling in an ERα-dependent manner by down-regulating the expression of three microRNAs, including let-7e-5p, miR-98-5p and miR-145a-5p. These microRNAs could target the 3'UTR of the IKKε-encoding gene IKBKE directly and regulate the expression of IKKε, which can promote the activation of IFN-α signaling. In addition, compared with age-matched male mice, female mice showed a higher level of IKKε and lower levels of let-7e-5p, miR-98-5p and miR-145a-5p in B cells. Moreover, peripheral blood mononuclear cells from women showed a higher level of IKKε and lower levels of let-7e-5p, miR-98-5p and miR-145a-5p compared with those from age-matched men. These data suggest that 17ß-estradiol amplifies the activation of IFN-α signaling in B cells via IKKε by down-regulating the expression of let-7e-5p, miR-98-5p and miR-145a-5p. Our findings may provide a new perspective for understanding the mechanism underlying the gender difference in the prevalence of SLE.

STS-1 promotes IFN-α induced autophagy by activating the JAK1-STAT1 signaling pathway in B cells.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the overexpression of IFN-α. IFN-α induces autophagy via the JAK1-STAT1 signaling pathway, contributing to the pathogenesis of SLE. Recent studies reported that B cells from patients with SLE and NZB/W F1 mice had enhanced autophagy activity; however, the mechanism still remains unknown. Here, we show that the protein tyrosine phosphatase STS-1 (suppressor of T-cell receptor signaling 1) was significantly overexpressed in B cells from patients with SLE and MRL/lpr mice. Notably, STS-1 promoted IFN-α-induced autophagy in B cells by enhancing the JAK1-STAT1 signaling activation. STS-1 inhibited the phosphorylation of the E3 ubiquitin protein ligase c-cbl, and subsequently promoted IFN-α-induced phosphorylation of tyrosine kinase 2, leading to JAK1-STAT1 signaling activation. Furthermore, STAT1 and JAK1 inhibitors blocked the IFN-α-induced autophagy promoted by STS-1, indicating that STS-1 promotes IFN-α-induced autophagy via the JAK1-STAT1 signaling. Our results demonstrate the importance of STS-1 in regulating IFN-α-induced autophagy in B cells, and this could be used as a therapeutic approach to treat SLE.

TLR9-induced miR-155 and Ets-1 decrease expression of CD1d on B cells in SLE.

B cells present lipid antigens to CD1d-restricted invariant natural killer T (iNKT) cells to maintain autoimmune tolerance, and this process is disrupted in systemic lupus erythematosus (SLE). Inflammation may inhibit CD1d expression to exacerbate the pathology of lupus. However, how inflammation regulates CD1d expression on B cells is unclear in SLE. In the present study, we showed that the surface expression of CD1d on B cells from SLE mice was decreased and that stimulation of inflammatory responses through TLR9 decreased the membrane and total CD1d levels of CD1d on B cells. Moreover, inflammation-related microRNA-155 (miR-155) negatively correlated with the expression of CD1d in B cells. miR-155 directly targeted the 3'-untranslated region (3'-UTR) of CD1d upon TLR9 activation in both humans and mice. The inhibitory effects of miR-155 on CD1d expression in B cells impaired their antigen-presenting capacity to iNKT cells. In addition, Ets-1, a susceptibility gene of SLE, also directly regulated the expression of the CD1d gene at the transcriptional level. These findings provide new insight into the mechanism underlying decreased CD1d expression on B cells in SLE, suggesting that inhibition of inflammation may increase CD1d expression in B cells to ameliorate SLE via modulating iNKT cells.

17ß-estradiol contributes to the accumulation of myeloid-derived suppressor cells in blood by promoting TNF-α secretion.

Estrogens are strongly implicated in gender differences in immune responses by influencing the development and activation of immune cells. Recent studies have shown that myeloid-derived suppressor cells (MDSCs), derived from CD11b(+)Gr-1(+) myeloid cells under pathological conditions, play vital roles in modulating immune responses. However, it is still unknown the effects of estrogens on MDSCs. In the present study, we investigated the effects and mechanisms of estrogens on regulating the accumulation of MDSCs. It was found that, compared with male patients with systemic lupus erythematosus (SLE), female patients with SLE showed a higher frequency of MDSCs in peripheral blood mononuclear cells and a higher level of tumor necrosis factor α (TNF-α) in serum. Notably, estradiol level in the serum of female patients with SLE was positively correlated with the frequency of MDSCs. Moreover, 17ß-estradiol could promote TNF-α-induced accumulation of MDSCs in vivo by increasing the fundamental frequency of CD11b(+)Gr-1(+) cells. Furthermore, 17ß-estradiol promoted the secretion of TNF-α in vivo, which contributed to the increase of the frequency of CD11b(+)Gr-1(+) cells. In addition, it was also found that female mice showed a higher frequency of CD11b(+)Gr-1(+) cells and a higher TNF-α level in blood than the age-matched male mice. These data indicate that 17ß-estradiol contributes to the accumulation of MDSCs in blood by promoting TNF-α secretion, which increases the fundamental frequency of CD11b(+)Gr-1(+) cells. Our findings provide a new insight into the mechanism of gender difference in the prevalence of inflammation and autoimmune diseases.

Differential expression of microRNAs in decidua-derived mesenchymal stem cells from patients with pre-eclampsia.

BACKGROUND: Mesenchymal stem cells (MSCs) at maternal-fetal interface are considered to play an important role in the pathogenesis of pre-eclampsia (PE). microRNAs (miRNAs) also have an important influence on differentiation, maturation, and functions of MSCs. Our aim in this study was to determine the differential expression of miRNAs in decidua-derived MSCs (dMSCs) from severe PE and normal pregnancies. RESULTS: miRNA expression profiles in dMSCs from five patients with severe PE and five healthy pregnant women were screened using microarray. Then, bioinformatic analysis of the microarray results was performed. Out of 179 differentially expressed miRNAs, 49 miRNAs had significant (p < 0.05) differential expression of ≥ 2.0-fold changes, including 21 up-regulated and 28 down-regulated. miRNA-Gene-network and miRNA-Gene ontology (GO) -network analyses were performed. Overall, 21 up-regulated and 15 down-regulated miRNAs showed high degrees in these analyses. Moreover, the significantly enriched signaling pathways and GOs were identified. The analyses revealed that pathways associated with cell proliferation, angiogenesis, and immune functions were highly regulated by the differentially expressed miRNAs, including Wnt signaling pathway, mitogen-activated protein kinase signaling pathway, transforming growth factor beta signaling pathway, T-cell receptor signaling pathway, and B cell receptor signaling pathway. Four miRNA predicted target genes, vascular endothelial growth factor A (VEGFA), indoleamine 2,3-dioxygenase, suppression of cytokine signaling 3, and serine/threonine protein phosphatase 2A 55 kDa regulatory subunit B α isoform (PPP2R2A) were all decreased in dMSCs from patients with PE. Furthermore, the physiological roles of miR-16 and miR-136 in the down-regulation of VEGFA and PPP2R2A, respectively, were confirmed through reporter assays. CONCLUSIONS: These findings suggest that miRNAs in dMSCs may be important regulatory molecules in the development of PE.

Extremely low frequency magnetic fields inhibit adipogenesis of human mesenchymal stem cells.

It was reported that obese (Ob/Ob) mice lose their weight and fat when treated with 0.5 T direct current electromagnetic fields. We also observed that 7.5 Hz, 0.4 T rotation of extremely low frequency magnetic fields (ELF-MF) has an inhibitory effect on obesity. Mesenchymal stem cells (MSCs) are multi-potent cells capable of differentiating to different MSC lineages, including adipose. We hypothesized that inhibitory effects of ELF-MF on obesity may be related to the differentiation of MSCs to adipocytes. In the present study, we investigated the effects of 7.5 Hz, 0.4 T ELF-MF on differentiation of human umbilical cord MSCs. We found that ELF-MF inhibited adipogenic differentiation (exposed 2 h/day for 15 days) of MSCs but had no effect on osteogenic differentiation (exposed 2 h/day for 21 days). Moreover, ELF-MF inhibited adipocyte-specific expression of peroxisome proliferator-activated receptor 2 (PPARγ2). ELF-MF promoted c-Jun N-terminal kinase (JNK)-dependent intracellular signaling in MSCs. Furthermore, activation of the non-canonical Wnt pathway provoked the inhibition of PPARγ2 expression resulting in suppression of adipogenic differentiation. In addition, the effects of ELF-MF on growth and apoptosis of MSCs were not observed. Our data indicated that ELF-MF of 7.5 Hz, 0.4 T inhibited the adipogenic differentiation of MSCs via JNK-dependent Wnt signaling pathway, but had no effect on the growth and function of MSCs, suggesting the inhibitory effect of ELF-MF on obesity may be attributed to the inhibition of differentiation of MSCs into adipocytes. This study may provide a potential approach for the treatment of obesity.

MicroRNA-181a regulates local immune balance by inhibiting proliferation and immunosuppressive properties of mesenchymal stem cells.

Mesenchymal stem cells (MSCs) exhibit extensive self-renewal potential and can modulate immunocyte activation. Our previous study reported that miR-181a expression was significantly increased in placenta from women with severe preeclampsia (PE), but the mechanisms by which miR-181a regulates MSCs are unknown. In this study, we asked if and how miR-181a regulates MSCs' proliferation and immunosuppressive properties. We found that the expression of miR-181a in the MSCs derived from the umbilical cord and decidua of PE patients increased relative to MSCs derived from normal patients. Transfection with miR-181a oligos prevented MSCs proliferation but did not affect MSCs apoptosis. Overexpression of miR-181a blocked activation of the TGF-ß signaling pathway and caused downregulation of target gene (TGFBR1 and TGFBRAP1) mRNA and protein expression. Reporter genes with putative miR-181a binding sites from the TGFBR1 and TGFBRAP1 3'-untranslated regions (3'-UTRs) were downregulated in the presence of miR-181a, suggesting that miR-181a binds to TGFBR1 and TGFBRAP1 3'-UTRs. In contrast, transfection of MSCs with miR-181a oligo enhanced expression of IL-6 and indoleamine 2,3-dioxygenase by activating p38 and JNK signaling pathways, respectively. MSCs transfected with miR-181a also enhanced the proliferation of T cells in a short-term culture. Additionally, treatment with control MSCs, but not miR-181a transfected MSCs, improved dextran sulfate sodium-induced experimental colitis, suggesting that miR-181a attenuates the immunosuppressive properties of MSCs in vivo. Together, our data demonstrate that miR-181a is an important endogenous regulator in the proliferation and immunosuppressive properties of MSCs.

Glioblastoma cellular MAP4K1 facilitates tumor growth and disrupts T effector cell infiltration.

MAP4K1 has been identified as a cancer immunotherapy target. Whether and how cancer cell-intrinsic MAP4K1 contributes to glioblastoma multiforme (GBM) progression remains unclear. We found that MAP4K1 was highly expressed in the glioma cells of human GBM specimens. High levels of MAP4K1 mRNA were prevalent in IDH-WT and 1p/19q non-codeletion gliomas and correlated with poor prognosis of patients. MAP4K1 silencing inhibited GBM cell proliferation and glioma growth. Transcriptome analysis of GBM cells and patient samples showed that MAP4K1 modulated cytokine‒cytokine receptor interactions and chemokine signaling pathway, including IL-18R and IL-6R Importantly, MAP4K1 loss down-regulated membrane-bound IL-18R/IL-6R by inhibiting the PI3K-AKT pathway, whereas MAP4K1 restoration rescued this phenotype and therefore GBM cell proliferation. MAP4K1 deficiency abolished GBM cell pro-proliferation responses to IL-18, suggesting an oncogenic role of MAP4K1 via the intrinsic IL-18/IL-18R pathway. In addition, GBM cell-derived MAP4K1 impaired T-cell migration and reduced CD8+ T-cell infiltration in mouse glioma models. Together, our findings provide novel insight into the pathological significance of GBM cell-intrinsic MAP4K1 in driving tumor growth and immune evasion by remodeling cytokine-chemokine networks.

Phagocytosis is a primary determinant of pulmonary clearance of clinical Klebsiella pneumoniae isolates.

Introduction: Klebsiella pneumoniae (Kp) is a common cause of hospital-acquired pneumonia. Although previous studies have suggested that evasion of phagocytic uptake is a virulence determinant of Kp, few studies have examined phagocytosis sensitivity in clinical Kp isolates. Methods: We screened 19 clinical respiratory Kp isolates that were previously assessed for mucoviscosity for their sensitivity to macrophage phagocytic uptake, and evaluated phagocytosis as a functional correlate of in vivo Kp pathogenicity. Results: The respiratory Kp isolates displayed heterogeneity in the susceptibility to macrophage phagocytic uptake, with 14 out of 19 Kp isolates displaying relative phagocytosis-sensitivity compared to the reference Kp strain ATCC 43816, and 5 out of 19 Kp isolates displaying relative phagocytosis-resistance. Intratracheal infection with the non-mucoviscous phagocytosis-sensitive isolate S17 resulted in a significantly lower bacterial burden compared to infection with the mucoviscous phagocytosis-resistant isolate W42. In addition, infection with S17 was associated with a reduced inflammatory response, including reduced bronchoalveolar lavage fluid (BAL) polymorphonuclear (PMN) cell count, and reduced BAL TNF, IL-1ß, and IL-12p40 levels. Importantly, host control of infection with the phagocytosis-sensitive S17 isolate was impaired in alveolar macrophage (AM)-depleted mice, whereas AM-depletion had no significant impact on host defense against infection with the phagocytosis-resistant W42 isolate. Conclusion: Altogether, these findings show that phagocytosis is a primary determinant of pulmonary clearance of clinical Kp isolates.

17ß-Estradiol enhances response of mice spleen B cells elicited by TLR9 agonist.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the production of autoantibodies against nucleic acid-associated antigens. B cells play cardinal roles in SLE. Many evidences have proved estrogen contribute to the gender bias in SLE and 17ß-estradiol (E2) could accelerate the disease by regulating B cells. On the other hand, B cells express TLR9 which recognized dsDNA and played a critical role in SLE. However, the crosstalk between estrogen and TLR9 in B cells remains unknown. So we investigated the E2 effect in the presence of the TLR9 ligand CpG on mice spleen B cells. We found that the up-regulation of cell viability, life-span, co-stimulation molecules (CD40, CD86) expression, IgM secretion, TLR9 and MCM6 expression were more significant than CpG ODN or E2 stimulated alone. It may provide a new way to investigate the mechanism of how E2 modulate the B cells function in lupus.

17ß-estradiol induces CD40 expression in dendritic cells via MAPK signaling pathways in a minichromosome maintenance protein 6-dependent manner.

OBJECTIVE: The human immune system exhibits sexual dimorphism in autoimmune diseases such as systemic lupus erythematosus (SLE). Female sex hormones, including 17ß-estradiol, are strongly implicated in the gender bias in SLE. CD40 is a costimulatory molecule and plays a crucial role in modulating the immune response of effector cells. We have previously shown that 17ß-estradiol up-regulated CD40 expression and altered minichromosome maintenance protein 6 (MCM6) gene expression in dendritic cells (DCs). The mechanism of the correlation between CD40 and MCM6 in the presence of 17ß-estradiol remains unknown. This study was undertaken to elucidate this mechanism and to explain the role of MCM6 in the gender bias in SLE. METHODS: Bone marrow-derived DCs transfected with small interfering RNA (siRNA) for MCM6 were treated with 17ß-estradiol in the absence or presence of CpG. The expression levels of costimulatory molecules, activity of MAPKs, and levels of MCM6 protein were measured. Moreover, the functions of DCs, including proliferation, apoptosis, endocytosis, and cytokine production, were analyzed. In addition, levels of messenger RNA for MCM6 were detected in DCs purified from SLE patients. RESULTS: Regardless of the presence or absence of CpG, 17ß-estradiol induced CD40 expression via the activation of p38 and JNK, but not ERK. The activation of p38 and JNK enhanced MCM6 expression, which then induced CD40 expression. Suppression of MCM6 in DCs abolished the up-regulation of 17ß-estradiol-induced CD40 expression. Importantly, MCM6 expression was significantly increased in SLE patients compared with healthy controls. CONCLUSION: Our findings indicate that 17ß-estradiol induces CD40 expression in DCs via p38 and JNK MAPKs in an MCM6-dependent manner. MCM6 may be a critical mediator of sex-based differences in autoimmune disease.

Lymphocyte subpopulations in Chinese women with Turner syndrome.

PURPOSE: Turner syndrome (TS) is associated with deficiency of cellular and humoral immunity. However, the characteristics of lymphocyte subpopulations in Chinese women with TS have not been reported. In this study, the percentage of lymphocyte subpopulations and the mRNA expression of some transcription factors were determined in patients with TS. The effect of the hormone substitution on lymphocyte subpopulations was also analyzed. METHODS: Thirteen Chinese TS women and eight age and sex-matched healthy volunteers were studied. The percentage and mean fluorescence intensity (MFI) of lymphocyte subpopulations including CD3+CD4+, CD3+CD8+, CD19-CD138+, CD4+CD25+FoxP3+ and CD4+CD8-IL17A+ cells were determined by flow cytometry. The mRNA expression of some transcription factors were detected by RT-PCR. RESULTS: Compared to control, the percentage of CD3+CD4+ cells was significantly reduced (p < 0.05), while the percentage of CD19-CD138+, CD4+CD25+FoxP3+ and CD4+CD8-IL17A+ cells was significantly increased in TS patients. No difference was observed in the percentage of CD3+CD8+, CD19+ B cells between TS patients and healthy volunteers, with the similar changes in the mean fluorescence intensity of these cells. The mRNA expression of some transcription factors slightly enhanced in TS patients. Estrogen therapy did not affect the percentage of lymphocyte subpopulations. CONCLUSION: These findings suggested that Turner syndrome might be associated with changes of lymphocyte subpopulations.

Strongylocentrotus nudus Eggs Polysaccharide Enhances Macrophage Phagocytosis Against E.coli Infection by TLR4/STAT3 Axis.

Antibiotics resistance is one of the most significant public health threats globally. Strategies that strengthen host defenses to control pathogen infection has become a hot research field. Macrophages are part of early host defense mechanisms, and are activated via host pattern recognition receptors (PRRs), such as Toll-like receptor 4 (TLR4), which then facilitates phagocytosis and elimination of invading pathogens. However, few activators of PRRs have been approved for clinical use because of their toxic effects. This study aimed to investigate whether Strongylocentrotus nudus eggs polysaccharide (SEP), a non-toxic extract from seafood, contributes to host defense against bacterial infection. Results showed that SEP promoted bacterial clearance by enhancing phagocytosis by macrophages during E. coli infection in vitro, but was inhibited by TLR4 specific inhibitor TAK-242, STAT3 inhibitor Stattic or blockade of CD64. In addition, SEP protected mice from E. coli induced mortality, reduced pulmonary inflammation and inhibited dissemination of bacteria to organs, while TAK-242 retarded the protection of SEP. Overall, SEP strengthened innate host defense and improved the outcome in bacterial infection, suggesting that SEP could be used as a potential immunomodulator in host-directed therapies.

Esculetin protects against early sepsis via attenuating inflammation by inhibiting NF-κB and STAT1/STAT3 signaling.

Esculetin, a natural derivative from the traditional and widely-used Chinese medicinal herb Cortex Fraxini, has a variety of pharmacological effects, especially in anti-inflammation. However, it is not clear whether esculetin has a therapeutic effect on sepsis. This study aimed to investigate the anti-inflammatory and protective effects of esculetin on early sepsis. The results showed that the lung injury was significantly relieved with the treatment of esculetin, accompanied with the restrained production of inflammatory factors including IL-1ß, IL-6, TNF-α, CCL2 and iNOS during the early phase of E.coli-induced sepsis. Of note, activation of NF-κB and STAT1/STAT3 signals, the main upstream signals of many inflammatory factors, were attenuated by esculetin in both lung tissues from septic mice and LPS-stimulated macrophage. These findings suggested that the protection of esculetin against early sepsis should be related to its anti-inflammatory effect, which was at least partly due to its inhibition on NF-κB and STAT1/STAT3 signaling pathway in macrophage. Thus, esculetin could serve as a potential therapeutic agent by rebalancing innate immune response in macrophage for the treatment of early sepsis.

Aesculin protects against DSS-Induced colitis though activating PPARγ and inhibiting NF-кB pathway.

Aesculin, a natural product from the traditional and widely-used Chinese medicine named Cortex fraxini, has attracted attention as a novel therapeutic modulator of inflammation. However, little is known about its effect on ulcerative colitis (UC). This study aimed to investigate the protective effects and mechanisms of aesculin on colitis. The results showed that, few cytotoxicity of aesculin were shown in vivo and in the RAW264.7 macrophages, while aesculin significantly relieved the symptoms of DSS-induced colitis and restrained the expression of inflammatory factors including iNOS, IL-1ß, TNF-α in both peritoneal macrophages and colonic tissues from DSS-induced mice and RAW264.7 macrophages. Of note, aesculin attenuated the activity of NF-κB signaling while promoted the nuclear localization of PPAR-γ in both rectal tissues from DSS-induced mice and LPS-stimulated macrophages. These findings demonstrated that the protection of aesculin against ulcerative colitis might be due to its regulation on the PPAR-γ and NF-κB pathway. Thus, aesculin could serve as a potential therapeutic agent for the treatment of ulcerative colitis.

GSKJ4 Protects Mice Against Early Sepsis via Reducing Proinflammatory Factors and Up-Regulating MiR-146a.

Sepsis, defined as life-threatening organ dysfunction, is one of the most common causes of mortality in intensive care units with limited therapeutic options. However, the mechanism underlying the regulation of epigenetics on sepsis remains largely undefined. Here we showed that JMJD3, the histone lysine demethylase, played a critical role in the epigenetic regulation of innate immunity during early sepsis. Pharmacological inhibition of JMJD3 by GSKJ4 protected mice against early septic death and reduced pro-inflammatory cytokine interleukin-1ß (IL-1ß) production as well as IL-6, tumor necrosis factor-α (TNF-α), and monocyte chemotactic protein-1 (MCP-1) expression. Interestingly, GSKJ4 up-regulated the transcription of anti-inflammatory microRNA-146a (miR-146a) in peritoneal macrophages from septic mice. Mechanistically, JMJD3 negatively regulated the transcription of miR-146a via its demethylation of H3K27me3 on the promoter of miR-146a. Moreover, the transcription of miR-146a was positively regulated by nuclear factor-κB (NF-κB) p65. Inhibition of NF-κB p65 promoted JMJD3 binding to miR-146a promoter and decreased the tri-methylation level of H3K27, while the inhibition of JMJD3 did not affect the recruitment of NF-κB p65 to miR-146a promoter. These results highlight an epigenetic mechanism by which JMJD3 was inhibited by NF-κB p65 from binding to miR-146a promoter to promote the anti-inflammatory response. Taken together, our findings uncover a key role for JMJD3 in modulating the miR-146a transcription and shed light on the JMJD3 inhibitors could be potential therapeutic agents for early sepsis therapy.