IL-37 is a potent inhibitor of innate immunity by shifting the cytokine equilibrium away from excessive inflammation. Psoriasis is thought to be initiated by abnormal interactions between the cutaneous keratinocytes and systemic immune cells, triggering keratinocyte hyperproliferation. In the current study, we assessed IL-37 in two well-known psoriasis models: a human keratinocyte cell line (HaCaT) and the keratin 14 VEGF-A–transgenic mouse model. First, we used the HaCaT cell line, which was transiently transfected with an overexpressing IL-37 vector, and tested the effect of IL-37 on these cells using a mixture of five proinflammatory cytokines. IL-37 was effective in suppressing the production of CXCL8, IL-6, and S100A7, which were highly upregulated by the mixture of five proinflammatory cytokines. Keratin 14 VEGF-A–transgenic mice were treated with plasmid coding human IL-37 sequence–formulated cationic liposomes, and we observed potent immunosuppressive effects over the 18-d period. In this model, we observed reduced systemic IL-10 levels, local IFN-γ gene transcripts, as well as mild mast cell infiltration into the psoriatic lesions of the mice. Immunohistochemical analysis indicated that IL-37 was expressed by effector memory T cells, as well as macrophages, in human psoriatic plaques. In conclusion, our studies strongly indicate that IL-37 plays a potent immunosuppressive role in the pathogenesis of both experimental psoriasis models in vitro and in vivo by downregulating proinflammatory cytokines. Importantly, our findings highlight new therapeutic strategies that can be designed to use this immunosuppressive anti-inflammatory cytokine in psoriasis and other inflammatory cutaneous diseases.

Prenylflavonoids are valuable natural products that are widely distributed in plants. They often possess divergent biological properties, including phytoestrogenic, anti‐bacterial, anti‐tumor, and anti‐diabetic activities. The reaction catalyzed by prenyltransferases represents a Friedel–Crafts alkylation of the flavonoid skeleton in the biosynthesis of natural prenylflavonoids and often contributes to the structural diversity and biological activity of these compounds. However, only a few plant flavonoid prenyltransferases have been identified thus far, and these prenyltransferases exhibit strict substrate specificity and low catalytic efficiency. In this article, a flavonoid prenyltransferase from Sophora flavescens, SfFPT, has been identified that displays high catalytic efficiency with high regiospecificity acting on C‐8 of structurally different types of flavonoid (i.e., flavanone, flavone, flavanonol, and dihydrochalcone, etc.). Furthermore, SfPFT exhibits strict stereospecificity for levorotatory flavanones to produce (2S)‐prenylflavanones. This study is the first to demonstrate the substrate promiscuity and stereospecificity of a plant flavonoid prenyltransferase in vitro. Given its substrate promiscuity and high catalytic efficiency, SfFPT can be used as an environmentally friendly and efficient biological catalyst for the regio‐ and stereospecific prenylation of flavonoids to produce bioactive compounds for potential therapeutic applications.

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The uptake by plants from soil is one of the first steps for hexachlorocyclohexane (HCH) isomers to enter the food web. However, the HCH transformation associated with the uptake process is still not well understood. Therefore, a soil−wheat pot experiment was conducted to characterize the HCH transformation during wheat growth using compound-specific isotope analysis (CSIA) and enantiomer fractionation. The results showed that the δ 13 C and δ 37 Cl values of β-HCH remained stable in soil and wheat, revealing no transformation. In contrast, an increase of δ 13 C and δ 37 Cl values of α-HCH indicated its transformation in soil and wheat. A shift of the enantiomer fraction (EF) (−) from 0.50 to 0.35 in soil at the jointing stage and 0.35 to 0.57 at the harvest stage suggested that the preferential transformation of enantiomers varied at different growth stages. Based on the dual element isotope analysis, the transformation mechanism in the soil−wheat system was different from that in wheat in hydroponic systems. The high abundance of HCH degraders, Sphingomonas sp. and Novosphingobium sp., was detected in the α-HCH-treated rhizosphere soil, supporting the potential for biotransformation. The application of CSIA and EF allows characterizing the transformation of organic pollutants such as HCHs in the complex soil−plant systems.

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A novel lncRNA, lncRNA-IFI6, regulates antiviral innate immunity in the JFH1 HCV infection model. lncRNA-IFI6 regulates HCV infection independently of the JAK-STAT pathway. lncRNA-IFI6 exerts its regulatory function via promoter activation and histone modification of IFI6 through its spatial domain. This article is protected by copyright. All rights reserved.

PH5 is a petunia gene that encodes a plasma membrane H+-ATPase and determines the vacuolar pH. The citrate content of fruit cell vacuoles influences citrus organoleptic qualities. Although citrus could have PH5-like homologs that are involved in citrate accumulation, the details are still unknown. In this study, extensive data-mining with the PH5 sequence and PCR amplification confirmed that there are at least eight PH5-like genes (CsPH1-8) in the citrus genome. CsPHs have a molecular mass of approximately 100 kDa, and they have high similarity to PhPH5, AtAHA10 or AtAHA2 (from 64.6 to 80.9%). They contain 13–21 exons and 12–20 introns and were evenly distributed into four subgroups of the P3A-subfamily (CsPH1, CsPH2, and CsPH3 in Group I, CsPH4 and CsPH5 in Group II, CsPH6 in Group IV, and CsPH7 and CsPH8 in Group III together with PhPH5). A transcript analysis showed that CsPH1, 3, and 4 were predominantly expressed in mature leaves, whereas CsPH2 and 7 were predominantly expressed in roots, CsPH5 and 6 were predominantly expressed in flowers, and CsPH8 was predominantly expressed in fruit juice sacs (JS). Moreover, the CsPH transcript profiles differed between orange and pummelo, as well as between high-acid and low-acid cultivars. The low-acid orange “Honganliu” exhibits low transcript levels of CsPH3, CsPH4, CsPH5, and CsPH8, whereas the acid-free pummelo (AFP) has only a low transcript level of CsPH8. In addition, ABA injection increased the citrate content significantly, which was accompanied by the obvious induction of CsPH2, 6, 7, and 8 transcript levels. Taken together, we suggest that CsPH8 seems likely to regulate citrate accumulation in the citrus fruit vacuole.

In citrus, lignin overaccumulation in the juice sac results in granulation and an unpleasant fruit texture and taste. By integrating metabolic phenotyping and transcriptomic analyses, we found 702 differentially expressed genes (DEGs), including 24 transcription factors (TFs), to be significantly correlated with lignin content. CgMYB58 was further identified as a critical R2R3 MYB TF involved in lignin overaccumulation owing to its high transcript levels in Huanong Red-fleshed pummelo (HR, Citrus grandis) fruits. Transient expression of CgMYB58 led to an increase in the lignin content in the pummelo fruit mesocarp, whereas its stable overexpression significantly promoted lignin accumulation and upregulated 19 lignin biosynthetic genes. Among these genes, CgPAL1, CgPAL2, Cg4CL1, and CgC3H were directly modulated by CgMYB58 through interaction with their promoter regions. Moreover, we showed that juice sac granulation in pummelo fruits could be affected by indole-3-acetic acid (IAA) and abscisic acid (ABA) treatments. In HR pummelo, ABA significantly accelerated this granulation, whereas IAA effectively inhibited this process. Taken together, these results provide novel insight into the lignin accumulation mechanism in citrus fruits. We also revealed the theoretical basis via exogenous IAA application, which repressed the expression of CgMYB58 and its target genes, thus alleviating juice sac granulation in orchards.