M1-polarized macrophages are involved in chronic inflammatory diseases, including nonalcoholic fatty liver disease (NAFLD). However, the mechanisms responsible for the activation of macrophages in NAFLD have not been fully elucidated. This study aimed at investigating the physiological mechanisms by which extracellular vesicles (EVs)-encapsulated microRNA-9-5p (miR-9-5p) derived from lipotoxic hepatocytes might activate macrophages in NALFD. After blood sample and cell collection, EVs were isolated and identified followed by co-culture with macrophages. Next, the palmitic acid-induced cell and high fat diet-induced mouse NALFD models were established to explore the in vitro and in vivo effects of EVs-loaded miR-9-5p on NAFLD as evidenced by inflammatory cell infiltration and inflammatory reactions in macrophages. Additionally, the targeting relationship between miR-9-5p and transglutaminase 2 (TGM2) was identified using dual-luciferase reporter gene assay. miR-9-5p was upregulated in the NAFLD-EVs, which promoted M1 polarization of THP-1 macrophages. Furthermore, miR-9-5p could target TGM2 to inhibit its expression. Downregulated miR-9-5p in NAFLD-EVs alleviated macrophage inflammation and M1 polarization as evidenced by reduced levels of macrophage inflammatory factors, positive rates of CD86+ CD11b+, and levels of macrophage surface markers in vitro. Moreover, the effect of silencing of miR-9-5p was replicated in vivo, supported by reductions in TG, TC, AST and ALT levels and attenuated pathological changes. Collectively, lipotoxic hepatocytes-derived EVs-loaded miR-9-5p downregulated the expression of TGM2 and facilitated M1 polarization of macrophages, thereby promoting the progression of NAFLD. This highlights a potential therapeutic target for treating NAFLD.
© The author(s).

Acute lymphoblastic leukemia (ALL) affects both children and adults. However, the prognosis of the two cohorts is quite different. The present aim was to review and evaluate one potential cause of why survival is poorer in adult ALL than pediatric ALL via fluorescence in situ hybridization (FISH). Clinical significant features were analyzed in 282 ALL cases. FISH was performed to study mixed lineage leukemia (MLL) translocation and the Philadelphia (Ph) chromosome in newly diagnosed patients, and was used to detect trisomy 4 or 10 and the translocation ETS leukemia-acute myeloid leukemia 1 (TEL-AML1) fusion gene. The overall survival/event-free survival (OS/EFS) outcome of adult ALL and pediatric ALL was analyzed using Kaplan-Meier analysis. Adult ALL had a higher median leukocyte count and lower hemoglobin level than pediatric ALL. FISH revealed that Ph positivity (Ph+) was associated with the high-risk feature of older age. In pediatric ALL, trisomy 4 or 10 was present in 71/207 cases (34.3%), while the TEL-AML1 fusion gene was present in 16/207 cases (7.7%). By contrast, there were very few such positive cases in adult ALL. Survival analysis revealed that, in adult ALL, the 3-year OS and EFS rates were higher in the Ph-negative group than in the Ph+ group. Adult or pediatric ALL is an independent prognostic factor of OS. The present analysis of the clinical and biological features between adult and pediatric ALL indicates that adult ALL has a poorer prognosis than pediatric ALL based on Ph+ status and presence of trisomy 4 or 10. Ph+ ALL is an independent prognosis factor of ALL. FISH may serve an important role in the comparison of prognostic factors in adult and pediatric ALL.

Hematopoietic stem cells (HSCs) give rise to diverse cell types in the blood system, yet our molecular understanding of the early trajectories that generate this enormous diversity in humans remains incomplete. Here, we leverage Drop-seq, a massively parallel single-cell RNA sequencing (scRNA-seq) approach, to individually profile 20,000 progenitor cells from human cord blood, without prior enrichment or depletion for individual lineages based on surface markers. Our data reveal a transcriptional compendium of progenitor states in human cord blood, representing four committed lineages downstream from HSC, alongside the transcriptional dynamics underlying fate commitment. We identify intermediate stages that simultaneously co-express "primed" programs for multiple downstream lineages, and also observe striking heterogeneity in the early molecular transitions between myeloid subsets. Integrating our data with a recently published scRNA-seq dataset from human bone marrow, we illustrate the molecular similarity between these two commonly used systems and further explore the chromatin dynamics of "primed" transcriptional programs based on ATAC-seq. Finally, we demonstrate that Drop-seq data can be utilized to identify new heterogeneous surface markers of cell state that correlate with functional output.
© 2018 The Authors. Published under the terms of the CC BY 4.0 license.

Inflammation is a part of the initial process leading to atherosclerosis and cholesterol crystals (CC), found in atherosclerotic plaques, which are known to induce complement activation. The pentraxins C-reactive protein (CRP), long pentraxin 3 (PTX3), and serum amyloid P component (SAP) are serum proteins associated with increased risk of cardiovascular events and these proteins have been shown to interact with the complement system. Whether the pentraxins binds to CC and mediate downstream complement-dependent inflammatory processes remains unknown. Binding of CRP, PTX3, and SAP to CC was investigated in vitro by flow cytometry and fluorescence microscopy. CRP, PTX3, and SAP bound to CC in a concentration-dependent manner. CRP and PTX3 interacted with the complement pattern recognition molecule C1q on CC by increasing the binding of both purified C1q and C1q in plasma. However, CRP was the strongest mediator of C1q binding and also the pentraxin that most potently elevated C1q-mediated complement activation. In a phagocytic assay using whole blood, we confirmed that phagocytosis of CC is complement dependent and initiated by C1q-mediated activation. The pathophysiological relevance of the in vitro observations was examined in vivo in human atherosclerotic plaques. CRP, PTX3, and SAP were all found in atherosclerotic plaques and were located mainly in the cholesterol-rich necrotic core, but co-localization with the terminal C5b-9 complement complex was only found for CRP. In conclusion, this study identifies CRP as a strong C1q recruiter and complement facilitator on CC, which may be highly relevant for the development of atherosclerosis.