TNF-α-mediated microRNA-136 induces differentiation of myeloid cells by targeting NFIA

miRNAs as key modulators between normal cells and tumor microenvironment interactions

The tumor microenvironment (TME) is well-defined target for understanding tumor progression and various cell types. Major elements of the tumor microenvironment are the followings: endothelial cells, fibroblasts, signaling molecules, extracellular matrix, and infiltrating immune cells. MicroRNAs (miRNAs) are a group of small noncoding RNAs with major functions in the gene expression regulation at post-transcriptional level that have also appeared to exerts key functions in the cancer initiation/progression in diverse biological processes and the tumor microenvironment. This study summarized various roles of miRNAs in the complex interactions between the tumor and normal cells in their microenvironment.

MicroRNAs/LncRNAs Modulate MDSCs in Tumor Microenvironment

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous group of immature cells derived from bone marrow that play critical immunosuppressive functions in the tumor microenvironment (TME), promoting cancer progression. According to base length, Non-coding RNAs (ncRNAs) are mainly divided into: microRNAs (miRNAs), lncRNAs, snRNAs and CircRNAs. Both miRNA and lncRNA are transcribed by RNA polymerase II, and they play an important role in gene expression under both physiological and pathological conditions. The increasing data have shown that MiRNAs/LncRNAs regulate MDSCs within TME, becoming one of potential breakthrough points at the investigation and treatment of cancer. Therefore, we summarize how miRNAs/lncRNAs mediate the differentiation, expansion and immunosuppressive function of tumor MDSCs in TME. We will then focus on the regulatory mechanisms of exosomal MicroRNAs/LncRNAs on tumor MDSCs. Finally, we will discuss how the interaction of miRNAs/lncRNAs modulates tumor MDSCs.

Characterization of a genomic region 8 kb downstream of GFI1B associated with myeloproliferative neoplasms

A genomic locus 8 kb downstream of the transcription factor GFI1B (Growth Factor Independence 1B) predisposes to clonal hematopoiesis and myeloproliferative neoplasms. One of the most significantly associated polymorphisms in this region is rs621940-G. GFI1B auto-represses GFI1B, and altered GFI1B expression contributes to myeloid neoplasms. We studied whether rs621940-G affects GFI1B expression and growth of immature cells. GFI1B ChIP-seq showed clear binding to the rs621940 locus. Preferential binding of various hematopoietic transcription factors to either the rs621940-C or -G allele was observed, but GFI1B showed no preference. In gene reporter assays the rs621940 region inhibited GFI1B promoter activity with the G-allele having less suppressive effects compared to the C-allele. However, CRISPR-Cas9 mediated deletion of the locus in K562 cells did not alter GFI1B expression nor auto-repression. In healthy peripheral blood mononuclear cells GFI1B expression did not differ consistently between the rs621940 alleles. Long range and targeted deep sequencing did not detect consistent effects of rs621940-G on allelic GFI1B expression either. Finally, we observed that myeloid colony formation was not significantly affected by either rs621940 allele in 193 healthy donors. Together, these findings show no evidence that rs621940 or its locus affect GFI1B expression, auto-repression or growth of immature myeloid cells.

Comparative profiling of exosomal miRNAs in human adult peripheral and umbilical cord blood plasma by deep sequencing

Aim: To assess differential expression profiles of miRNAs in exosomes derived from human peripheral blood (PB) and umbilical cord blood (UCB). Materials & methods: Small RNA sequencing was performed to characterize the miRNA expression in plasma exosomes processed from UCB of five healthy newborns and PB of five normal adult volunteers, and differentially expressed miRNAs were further analyzed. Results: A total of 65 exosomal miRNAs, including 46 upregulated and 19 downregulated, showed differential expression between UCB and PB. Target genes of these miRNAs were mainly enriched in signaling pathways associated with pregnancy, cancers, cell mobility and nervous system. Conclusion: Exosomal miRNAs may have essential roles in the biological functions of UCB, suggesting the therapeutic and biomarker potentials of exosomes in UCB.

MicroRNA networks regulate the differentiation, expansion and suppression function of myeloid-derived suppressor cells in tumor microenvironment

Myeloid-derived suppressor cells (MDSCs), one heterogeneous population of immature myeloid cells, have suppressive function on immune response during tumor, inflammation, infection and autoimmune diseases. The molecular mechanism underlying expansion and function of MDSCs is becoming appreciated to manipulate immune response in the diseases. MicroRNA (miRNAs) as one short noncoding RNAs, are involved in regulating cell proliferation, differentiation and maturation. However, it needs to be further studied how miRNAs mediate the development and function of MDSC in association with cancer and other diseases. In the review, we report and discuss recent studies that miRNAs networks regulate the differentiation, expansion and suppression function of MDSCs in tumor microenvironment or other diseases through different signaling pathways. Those studies may provide one novel potential approach for tumor immunotherapy.

TNF-α Inhibitors Decrease Classical CD14hiCD16- Monocyte Subsets in Highly Active, Conventional Treatment Refractory Rheumatoid Arthritis and Ankylosing Spondylitis

Monocytes are pivotal cells in inflammatory joint diseases. We aimed to determine the effect of TNF-α inhibitors (TNFi) on peripheral blood monocyte subpopulations and their activation in ankylosing spondylitis (AS) and rheumatoid arthritis (RA) patients with high disease activity. To address this, we studied 50 (32 AS, 18 RA) patients with highly active disease with no prior history of TNFi use who were recruited and assigned to TNFi or placebo treatment for 12 weeks. Cytometric and clinical assessment was determined at baseline, four, and 12 weeks after initiation of TNFi treatment. We observed that treatment with TNFi led to a significant decrease in CD14^hiCD16- monocytes in comparison to placebo, while circulating CD14^dimCD16+ monocytes significantly increased. The TNFi-induced monocyte subset shifts were similar in RA and AS patients. While the percentage of CD14^dimCD16+ monocytes increased, expression of CD11b and CD11c integrins on their surface was significantly reduced by TNFi. Additionally, CD45RA+ cells were more frequent. The shift towards nonclassical CD14^dimCD16+ monocytes in peripheral blood due to TNFi treatment was seen in both AS and RA. This may reflect reduced recruitment of these cells to sites of inflammation due to lower inflammatory burden, which is associated with decreased disease activity.

Dihydrocapsaicin suppresses proinflammatory cytokines expression by enhancing nuclear factor IA in a NF-κB-dependent manner

BACKGROUND

Atherosclerosis is a chronic inflammatory disease and represents the leading cause of morbidity and mortality throughout the world. Accumulating evidences have showed that Dihydrocapsaicin (DHC) has been found to exert multiple pharmacological and physiological effects. Nevertheless, the effects and possible mechanism of DHC on proinflammatory response remain largely unexplained.

METHODS AND RESULTS

We found that DHC markedly upregulated NFIA and suppressed NF-κB expression in THP-1 macrophages. Up-regulation of proinflammatory cytokines induced by LPS including TNF-α, IL-1β and IL-6 were markedly suppressed by DHC treatment. We also observed that protein level of NFIA was significantly increased while NF-κB and proinflammatory cytokines were decreased by DHC treatment in apoE(-/-) mice. Lentivirus-mediated overexpression of NFIA suppressed NF-κB and proinflammatory cytokines expression both in THP-1 macrophages and plaque tissues of apoE-/- mice. Moreover, treatment with lentivirus-mediated overexpression of NFIA made the down-regulation of DHC on NF-κB and proinflammatory cytokines expression notably accentuated in THP-1 macrophages and apoE(-/-) mice. In addition, treatment with siRNA targeting NF-κB accentuated the suppression of proinflammatory cytokines by lentivirus-mediated overexpression of NFIA.

CONCLUSION

These observations demonstrated that DHC can significantly decrease proinflammatory cytokines through enhancing NFIA and inhibiting NF-κB expression and thus DHC may be a promising candidate as an anti-inflammatory drug for atherosclerosis as well as other disorders.

TNFRSF1B Is Associated with ANCA in IBD

The genetic basis of antineutrophil cytoplasmic antibody, an important biomarker of inflammatory bowel disease (IBD), has never been thoroughly examined on a genome-wide scale. In this study, we performed a 2-stage genome-wide association study (GWAS) on antineutrophil cytoplasmic antibody in IBD cases. In the 2959 IBD cases in the discovery stage, we observed an association between a variant in the gene TNFRSF1B with antineutrophil cytoplasmic antibody level (rs5745994, minor allele frequency = 0.028, beta = 18.12, 95% CI, 11.82-24.22, P = 1.89 × 10). This association was replicated in an independent cohort of 419 IBD cases (beta = 16.91, 95% CI, 6.13-27.69, P = 2.38 × 10). With a Q-value of 0.036, we performed a fixed-effect meta-analysis for the association of rs5745994 in both cohorts and observed a stronger association signal (beta = 17.81, 95% CI, 12.36-23.25, P = 8.97 × 10). TNFRSF1B gene codes for tumor necrosis factor (TNF) receptor 2 (TNFR2), thereby we examined the reported TNFRSF1B variant with serum TNFR2 level. We observed a negative association with serum TNFR2 level being 8.23 EU/mL in carriers and 9.12 EU/mL in noncarriers (P = 0.033). This finding indicates the functional role of identified TNFRSF1B variant in IBD serology and may be reflective of the underlying biological mechanisms that determine clinical expression and/or response to certain therapies.