Peripheral blood neutrophils form highly decondensed chromatin structures, termed neutrophil extracellular traps (NETs), that have been implicated in innate immune response to bacterial infection. Neutrophils express high levels of peptidylarginine deiminase 4 (PAD4), which catalyzes histone citrullination. However, whether PAD4 or histone citrullination plays a role in chromatin structure in neutrophils is unclear. In this study, we show that the hypercitrullination of histones by PAD4 mediates chromatin decondensation. Histone hypercitrullination is detected on highly decondensed chromatin in HL-60 granulocytes and blood neutrophils. The inhibition of PAD4 decreases histone hypercitrullination and the formation of NET-like structures, whereas PAD4 treatment of HL-60 cells facilitates these processes. The loss of heterochromatin and multilobular nuclear structures is detected in HL-60 granulocytes after PAD4 activation. Importantly, citrullination of biochemically defined avian nucleosome arrays inhibits their compaction by the linker histone H5 to form higher order chromatin structures. Together, these results suggest that histone hypercitrullination has important functions in chromatin decondensation in granulocytes/neutrophils.

ARTICLE This journal isHierarchically porous carbons (HPCs) show great potentials in energy storage due to their high surface area as well as short ion transport path derived from the interconnected porous framework. However, most existing protocols highly rely on the nanocasting and soft -templating, which usually restrict the using of raw materials and thus industrial unfeasible. It still reminds a big challenge to build HPCs from crude biomass, which is abundant on the earth, through a simply one-pot approach. Inspired by leavening bread, we design a strategy to fabricate HPCs with three-dimensional (3D) hierarchical pores consisting of macro, meso, and micropores. The "leavening method" is conducted simply by mixing the biomass with KHCO3 followed by undergoing elevated temperature treatment. Besides the well-defined hierarchical structure, the as-prepared HPCs also exhibit notably large specific areas (up to 1893 m 2 g -1 ). It is noteworthy that this "leavening" strategy is widely applicable for most of biomass derivatives and biomass, including glucose, cellulose, chitin, starch, rice straw, bamboo, and etc. When evaluated as supercapacitor electrode materials in two-electrode test systems, the as-prepared HPCs exhibit an excellent electrochemical performance: specific capacitance of 253 F g -1 , almost no capacitance loss after 10 000 cycles.Scheme 1 Scheme diagram of the formation of Cx-LE: mixing the biomass with the "leavening" agents, followed by calcination under the insert gas for the synthesis of Cx-LE.A simple and universal methodology for carbon materials derived from biomass with hierarchical structure.

Developing novel and efficient catalysts is always an important theme for heterogeneous catalysis from fundamental and applied research points of view. In the past, carbon materials were used as supports for numerous heterogeneous catalysts because of their fascinating properties including high surface areas, tunable porosity, and functionality. Recently, the newly emerging N-doped carbon-supported metal catalysts have arguably experienced great progress and brought the most attention over the last decades in view of the fact that nitrogen doping can tailor the properties of carbon for various applications of interest. Compared with pristine carbon-supported metal catalysts, these catalysts normally show superior catalytic performance in many heterogeneous catalytic reactions because of the introduced various metal–support interactions from N doping. In this Perspective, we focus on the fabrication methods for N-doped carbon-supported metal catalysts and the catalytic application of these fascinating catalysts in several industrially relevant reactions, including hydrogenation, dehydrogenation, oxidation, and coupling. Notably, we try to elucidate the structure–activity correlations obtained from theoretical calculation, extensive characterization, and observed catalytic performances, thereby providing guidance for the rational design of advanced catalysts for heterogeneous catalysis.

IntroductionAlthough immune dysfunction plays a role in the pathogenesis of systemic sclerosis (SSc), involvement of T helper 17 (Th17) and T regulatory (Treg) cells remains unclear. We aimed to investigate the presence of Th17 and Treg cells in SSc patients and the role of Th17 cells in collagen production in SSc fibroblasts.MethodsWe analyzed inflammatory cell profiles in the skin of 13 SSc patients by immunohistochemistry, the percentage of Th17 and Treg cells in peripheral blood mononuclear cells (PBMCs) of 45 SSc patients and 24 healthy controls by flow cytometry, gene expression in PBMCs by real-time reverse transcription-polymerase chain reaction and interleukin-17 (IL-17) in sera and culture supernatants by enzyme-linked immunosorbent assay. We also investigated the effect of Th17 cell-derived IL-17 on fibroblast growth and collagen production.ResultsInfiltration of inflammatory cells including IL-17+ and Foxp3+ lymphocytes was detected in the skin of patients with early SSc. The percentages of circulating Th17 cells and IL-17 production were elevated in samples from patients with active SSc, whereas the percentage of circulating Treg cells was not affected. The number of Th17 cells was closely related to disease activity. IL-17 from SSc patients promoted fibroblast growth and collagen production, whereas IL-17 neutralizing antibody effectively blocked collagen production.ConclusionSSc progression might be linked to expansion of circulating Th17 cells and increased infiltration of IL-17+ cells in skin. Th17-derived IL-17 is involved in fibroblast growth and collagen production. IL-17 blocking antibody may be a useful tool for intervention in the fibrotic course of SSc.