Different expression patterns of duplicated PHANTASTICA-like genes in Lotus japonicus suggest their divergent functions during compound leaf development

Recent studies on leaf development demonstrate that the mechanism on the adaxial-abaxial polarity pattern formation could be well conserved among the far-related species, in which PHANTASTICA （PAHN）-Iike genes play important roles. In this study, we explored the conservation and diversity on functions of PHAN-Iike genes during the compound leaf development in Lotusjaponicus, a papilionoid legume. Two PHAN-Iike genes in L. japonicus, LjPHANa and LjPHANb, were found to originate from a gene duplication event and displayed different expression patterns during compound leaf development. Two mutants, reduced leafletsl （rell） and reduced leaflets3 （rel3）, which exhibited decreased adaxial identity of leaflets and reduced leaflet initiation, were identified and investigated. The expression patterns of both LjPHANs in rel mutants were altered and correlated with abnormalities of compound leaves. Our data suggest that LjPHANa and LjPHANb play important but divergent roles in regulating adaxial-abaxial polarity of compound leaves in L. japonicus.

氢键作用构建含硅嵌段共聚物超分子复合物及其自组装行为研究

通过聚二甲基硅氧烷-b-聚(2-乙烯基吡啶)(PDMS-b-P2VP,DV)与4-羟基偶氮苯(Azo)之间的氢键相互作用,构建了具有光响应的含硅嵌段共聚物(DV(Azo)x)超分子复合体系,研究了该复合体系的自组装行为.利用溶液共混法制备了具有不同4-羟基偶氮苯含量的超分子嵌段共聚物.通过傅里叶红外光谱(FTIR)、示差扫描量热仪(DSC)、小角X射线散射(SAXS)和透射电镜(TEM)等研究了小分子与共聚物之间的相互作用以及小分子含量对该复合体系自组装结构的影响规律.实验结果表明4-羟基偶氮苯与PDMS-b-P2VP中吡啶基团之间能有效形成氢键.Azo的加入会降低P2VP的玻璃化转变温度,提高P2VP嵌段的体积分数,从而导致复合物自组装结构发生层状到六方柱状再到体心立方结构的转变.而当Azo摩尔比>0.5时,Azo自身聚集比较严重,相分离结构变得无序.后续研究将关注偶氮苯分子构象变化调控薄膜态自组装结构取向行为.

A dual-responsive hyaluronic acid nanocomposite hydrogel drug delivery system for overcoming multiple drug resistance

Chemotherapy is restricted by efficient drug outflow due to the multiple drug resistance(MDR)in heterogenous nature of tumor.Herein,we present a dual-responsive hyaluronic acid(HA)nanocomposite hydrogel that can not only response to the tumor microenvironment but also enhance chemotherapy.This HA hydrogel consists of a core-shell SiO_(2)(GOD@SiO_(2)-Arg)and mesoporous silica nanoparticles(MSNs)with doxorubicin(DOX)as the cargo(DOX@MSN).It could rapidly release the GOD@SiO_(2)-Arg nanoparticles at the low p H tumor-specific environment due to the cleavage of imine bond.GOD@SiO_(2)-Arg activated by over-expressed glutathione(GSH)in tumor cells releases GOD due to the cleavage of disulfide bonds,which could oxidize glucose to produce hydrogen peroxide(H2O2)for in situ NO generation via reaction between Arg and H2O2.The validity of this study might provide a method to modulate the tumor microenvironment for enhancing chemotherapy.

Multiple Components are Integrated to Determine Leaf Complexity in Lotus japonicus

Transcription factors and phytohormones have been reported to play crucial roles to regulate leaf complexity among plant species. Using the compound-leafed species Lotus japonicus, a model legume plant with five visible leaflets, we characterized four independent mutants with reduced leaf complexity, proliferating floral meristem （pfm）, proliferating floral organ-2 （pfo-2）, fused leaflets1 （ful1） and umbrella leaflets （uml）, which were further identified as loss-of-function mutants of Arabidopsis orthologs LEAFY （LFY ）, UNUSUAL FLORAL ORGANS （UFO）, CUP-SHAPED COTYLEDON 2 （CUC2） and PIN-FORMED 1 （PIN1）, respectively. Comparing the leaf development of wild-type and mutants by a scanning electron microscopy approach, leaflet initiation and/or dissection were found to be affected in these mutants. Expression and phenotype analysis indicated that PFM/LjLFY and PFO/LjUFO determined the basipetal leaflet initiation manner in L. japonicus. Genetic analysis of ful1 and uml mutants and their double mutants revealed that the CUC2-like gene and auxin pathway also participated in leaflet dissection in L. japonicus, and their functions might influence cytokinin biogenesis directly or indirectly. Our results here suggest that multiple genes were interplayed and played conserved functions in controlling leaf complexity during compound leaf development in L. japonicus.

LATHYROIDES, Encoding a WUSCHEL-Related Homeoboxl Transcription Factor, Controls Organ Lateral Growth, and Regulates Tendril and Dorsal Petal Identities in Garden Pea （Pisum sativum L.）

During organ development, many key regulators have been identified in plant genomes, which play a conserved role among plant species to control the organ identities and/or determine the organ size and shape. It is intriguing whether these key regulators can acquire diverse function and be integrated into different molecular pathways among different species, giving rise to the immense diversity of organ forms in nature. In this study, we have characterized and cloned LATHYROIDES （LATH）, a classical locus in pea, whose mutation displays pleiotropic alteration of lateral growth of organs and predominant effects on tendril and dorsal petal development. LATH encodes a WUSCHEL-related home- oboxl （WOX1） transcription factor, which has a conserved function in determining organ lateral growth among different plant species. Furthermore, we showed that LATH regulated the expression level of TENDRIL-LESS （TL）, a key factor in the control of tendril development in compound leaf, and LATH genetically interacted with LOBED STANDARD （LST）, a floral dorsal factor, to affect the dorsal petal identity. Thus, LATH plays multiple roles during organ development in pea： it maintains a conserved function controlling organ lateral outgrowth, and modulates organ identities in compound leaf and zygomorphic flower development, respectively. Our data indicated that a key regulator can play important roles in different aspects of organ development and dedicate to the complexity of the molecular mechanism in the control of organ development so as to create distinct organ forms in different species.

Engineered neutrophil apoptotic bodies ameliorate myocardial infarction by promoting macrophage efferocytosis and inflammation resolution

Inflammatory response plays a critical role in myocardial infarction(MI)repair.The neutrophil apoptosis and subsequent macrophage ingestion can result in inflammation resolution and initiate regeneration,while the therapeutic strategy that simulates and enhances this natural process has not been established.Here,we constructed engineered neutrophil apoptotic bodies(eNABs)to simulate natural neutrophil apoptosis,which regulated inflammation response and enhanced MI repair.The eNABs were fabricated by combining natural neutrophil apoptotic body membrane which has excellent inflammation-tropism and immunoregulatory properties,and mesoporous silica nanoparticles loaded with hexyl 5-aminolevulinate hydrochloride(HAL).The eNABs actively targeted to macrophages and the encapsulated HAL simultaneously initiated the biosynthesis pathway of heme to produce anti-inflammatory bilirubin after intracellular release,thereby further enhancing the anti-inflammation effects.In in vivo studies,the eNABs efficiently modulated inflammation responses in the infarcted region to ameliorate cardiac function.This study demonstrates an effective biomimetic construction strategy to regulate macrophage functions for MI repair.

Petal Development in Lotus japonicus

Previous studies have demonstrated that petal shape and size in legume flowers are determined by two separate mechanisms, dorsoventral （DV） and organ internal （IN） asymmetric mechanisms, respectively. However, little is known about the molecular mechanisms controlling petal development in legumes. To address this question, we investigated petal development along the floral DV axis in Lotus japonicus with respect to cell and developmental biology by comparing wild-type legumes to mutants. Based on morphological markers, the entire course of petal development, from initiation to maturity, was grouped to define 3 phases or 13 stages. In terms of epidermal micromorphology from adaxial surface, mature petals were divided into several distinct domains, and characteristic epidermal cells of each petal differentiated at stage 9, while epidermal cells of all domains were observed until stage 12. TCP and MIXTA-like genes were found to be differentially expressed in various domains of petals at stages 9 and 12. Our results suggest that DV and IN mechanisms interplay at different stages of petal development, and their interaction at the cellular and molecular level guides the elaboration of domains within petals to achieve their ideal shape, and further suggest that TCP genes determine petal identity along the DV axis by regulatincl MIXTA-like clene expression.

The anti-scarring effect of corneal stromal stem cell therapy is mediated by transforming growth factorβ3

Background:Corneal stromal stem cells(CSSC)reduce corneal inflammation,prevent fibrotic scarring,and regenerate transparent stromal tissue in injured corneas.These effects rely on factors produced by CSSC to block the fibrotic gene expression.This study investigated the mechanism of the scar-free regeneration effect.Methods:Primary human CSSC(hCSSC)from donor corneal rims were cultivated to passage 3 and co-cultured with mouse macrophage RAW264.7 cells induced to M1 pro-inflammatory phenotype by treatment with interferonγand lipopolysaccharides,or to M2 anti-inflammatory phenotype by interleukin-4,in a Transwell system.The timecourse expression of human transforming growth factorβ3(hTGFβ3)and hTGFβ1 were examined by immunofluorescence and qPCR.TGFβ3 knockdown for>70%in hCSSC[hCSSC-TGFβ3(si)]was achieved by small interfering RNA transfection.Naïve CSSC and hCSSC-TGFβ3(si)were transplanted in a fibrin gel to mouse corneas,respectively,after wounding by stromal ablation.Corneal clarity and the expression of mouse inflammatory and fibrosis genes were examined.Results:hTGFβ3 was upregulated by hCSSC when co-cultured with RAW cells under M1 condition.Transplantation of hCSSC to wounded mouse corneas showed significant upregulation of hTGFβ3 at days 1 and 3 post-injury,along with the reduced expression of mouse inflammatory genes(CD80,C-X-C motif chemokine ligand 5,lipocalin 2,plasminogen activator urokinase receptor,pro-platelet basic protein,and secreted phosphoprotein 1).By day 14,hCSSC treatment significantly reduced the expression of fibrotic and scar tissue genes(fibronectin,hyaluronan synthase 2,Secreted protein acidic and cysteine rich,tenascin C,collagen 3a1 andα-smooth muscle actin),and the injured corneas remained clear.However,hCSSC-TGFβ3(si)lost these anti-inflammatory and anti-scarring functions,and the wounded corneas showed intense scarring.Conclusion:This study has demonstrated that the corneal regenerative effect of hCSSC is mediated by TGFβ3,inducing a scar-free tissue response.

Fruit size control by a zinc finger protein regulating pericarp cell size in tomato

Fruit size is largely defined by the number and size of cells in the fruit.Endoreduplication–a specialized cell cycle–is highly associated with cell expansion during tomato fruit growth.However,how endoreduplication coupled with cell size is regulated remains poorly understood.In this study,we identified a zinc finger gene SlPZF1(Solanum lycopersicum PERICARP-ASSOCIATED ZINC FINGER PROTEIN 1)that was highly expressed in the pericarp of developing fruits.Plants with altered SlPZF1 expression produced smaller fruits due to the reduction in cell size associated with weakened endoreduplication.Overexpressing SlPZF1 delayed cell division phase by enhancing early expression of several key cell cycle regulators including SlCYCD3;1 and two plant specific mitotic cyclin-dependent protein kinase(SlCDKB1 and SlCDKB2)in the pericarp tissue.Furthermore,we identified 14 putative SlPZF1 interacting proteins(PZFIs)via yeast two hybrid screening.Several PZFIs,including Pre-mRNA-splicing factor(SlSMP1/PZFI4),PAPA-1-like conserved region family protein(PZFI6),Fanconi anemia complex components(PZFI3 and PZFI10)and bHLH transcription factor LONESOME HIGHWAY(SILHW/PZFI14),are putatively involved in cell cycle regulation.Our results demonstrate that fruit growth in tomato requires balanced expression of the novel cell size regulator SlPZF1.