Feedback regulation of coronary artery disease susceptibility gene ADTRP and LDL receptors LDLR/CD36/LOX-1 in endothelia cell functions involved in atherosclerosis

A high level of low-density lipoprotein cholesterol (LDL) is one of the most important risk factors for coronary artery disease (CAD), the leading cause of death worldwide. However, a low concentration of LDL may be protective. Genome-wide association studies revealed that variation in ADTRP gene increased the risk of CAD. In this study, we found that a low concentration of oxidized-LDL induced the expression of ADTRP. Further analyses showed that knockdown of the expression of LDL receptor genes LDLR, CD36, or LOX-1 significantly downregulated ADTRP expression, whereas overexpression of LDLR/CD36/LOX-1 markedly increased ADTRP expression through the NF-κB pathway. Like ADTRP, LDLR, CD36 and LOX-1 were all involved in endothelial cell (EC) functions relevant to the initiation of atherosclerosis. Downregulation of LDLR/CD36/LOX-1 promoted monocyte adhesion to ECs and transendothelial migration of monocytes by increasing expression of ICAM-1, VCAM-1, E-selectin and P-selectin, decreased EC proliferation and migration, and increased EC apoptosis, thereby promoting the initiation of atherosclerosis. Opposite effects were observed with the overexpression of ADTRP and LDLR/CD36/LOX-1 in ECs. Interestingly, through the NF-κB and AKT pathways, overexpression of ADTRP significantly upregulated the expression of LDLR, CD36, and LOX-1, and knockdown of ADTRP expression significantly downregulated the expression of LDLR, CD36, and LOX-1. These data suggest that ADTRP and LDL receptors LDLR/CD36/LOX-1 positively regulate each other, and form a positive regulatory loop that regulates endothelial cell functions, thereby providing a potential protective mechanism against atherosclerosis. Our findings provide a new molecular mechanism by which deregulation of ADTRP and LDLR/CD36/LOX-1 promote the development of atherosclerosis and CAD.     

CCR-NB-LRR proteins MdRNL2 and MdRNL6 interact physically to confer broad-spectrum fungal resistance in apple (Malus × domestica)

Apple leaf spot, a disease caused by Alternaria alternata f. sp. mali and other fungal species, leads to severe defoliation and results in tremendous losses to the apple (Malus × domestica) industry in China. We previously identified three RPW8, nucleotide-binding, and leucine-rich repeat domain CC_R-NB-LRR proteins (RNLs), named MdRNL1, MdRNL2, and MdRNL3, that contribute to Alternaria leaf spot (ALT1) resistance in apple. However, the role of NB-LRR proteins in resistance to fungal diseases in apple remains poorly understood. We therefore used MdRNL1/2/3 as baits to screen ALT1-inoculated leaves for interacting proteins and identified only MdRNL6 (another RNL) as an interactor of MdRNL2. Protein interaction assays demonstrated that MdRNL2 and MdRNL6 interact through their NB-ARC domains. Transient expression assays in apple indicated that complexes containing both MdRNL2 and MdRNL6 are necessary for resistance to Alternaria leaf spot. Intriguingly, the same complexes were also required to confer resistance to Glomerella leaf spot and Marssonina leaf spot in transient expression assays. Furthermore, stable transgenic apple plants with suppressed expression of MdRNL6 showed hypersensitivity to Alternaria leaf spot, Glomerella leaf spot, and Marssonina leaf spot; these effects were similar to the effects of suppressing MdRNL2 expression in transgenic apple plantlets. The identification of these novel broad-spectrum fungal resistance genes will facilitate breeding for fungal disease resistance in apple.     

An efficient Oligo-FISH painting system for revealing chromosome rearrangements and polyploidization in Triticeae

A chromosome-specific painting technique has been developed which combines the most recent approaches of the companion disciplines of molecular cytogenetics and genome research. We developed seven oligonucleotide (oligo) pools derivd from single-copy sequences on chromosomes 1 to 7 of barley (Hordeum vulgare L.) and corresponding collinear regions of wheat (Triticum aestivum L.). The seven groups of pooled oligos comprised between 10 986 and 12 496 45-bp monomers, and these then produced stable fluorescence in situ hybridization (FISH) signals on chromosomes of each linkage group of wheat and barley. The pooled oligo probes were applied to high-throughput karyotyping of the chromosomes of other Triticeae species in the genera Secale, Aegilops, Thinopyrum, and Dasypyrum, and the study also extended to some wheat-alien amphiploids and derived lines. We demonstrated that a complete set of whole-chromosome oligo painting probes facilitated the study of inter-species chromosome homologous relationships and visualized non-homologous chromosomal rearrangements in Triticeae species and some wheat-alien species derivatives. When combined with other non-denaturing FISH procedures using tandem-repeat oligos, the newly developed oligo painting techniques provide an efficient tool for the study of chromosome structure, organization, and evolution among any wild Triticeae species with non-sequenced genomes.     

A Plasmopara viticola RXLR effector targets a chloroplast protein PsbP to inhibit ROS production in grapevine

Pathogens secrete a large number of effectors that manipulate host processes to create an environment conducive to pathogen colonization. However, the underlying mechanisms by which Plasmopara viticola effectors manipulate host plant cells remain largely unclear. In this study, we reported that RXLR31154, a P. viticola RXLR effector, was highly expressed during the early stages of P. viticola infection. In our study, stable expression of RXLR31154 in grapevine (Vitis vinifera) and Nicotiana benthamiana promoted leaf colonization by P. viticola and Phytophthora capsici, respectively. By yeast two-hybrid screening, the 23-kDa oxygen-evolving enhancer 2 (VpOEE2 or VpPsbP), encoded by the PsbP gene, in Vitis piasezkii accession Liuba-8 was identified as a host target of RXLR31154. Overexpression of VpPsbP enhanced susceptibility to P. viticola in grapevine and P. capsici in N. benthamiana, and silencing of NbPsbPs, the homologs of PsbP in N. benthamiana, reduced P. capcisi colonization, indicating that PsbP is a susceptibility factor. RXLR31154 and VpPsbP protein were co-localized in the chloroplast. Moreover, VpPsbP reduced H₂O₂ accumulation and activated the ¹O₂ signaling pathway in grapevine. RXLR31154 could stabilize PsbP. Together, our data revealed that RXLR31154 reduces H₂O₂ accumulation and activates the ¹O₂ signaling pathway through stabilizing PsbP, thereby promoting disease.     

Endometrial extracellular matrix rigidity and IFNτ ensure the establishment of early pregnancy through activation of YAP

BackgroundIn mammals, early pregnancy is a critical vulnerable period during which complications may arise, including pregnancy failure. Establishment of a maternal endometrial acceptance phenotype is a prerequisite for semiheterogeneous embryo implantation, comprising the rate‐limiting step of early pregnancy.MethodsConfocal fluorescence, immunohistochemistry and western blot for nuclear and cytoplasmic protein were used to examine the activation of yes‐associated protein (YAP) in uterine tissue and primary endometrial cells. The target binding between miR16a and YAP was verified by dual‐luciferase reporter gene assay. The mouse pregnancy model and pseudopregnancy model were used to investigate the role of YAP in the maternal uterus during early pregnancy in vivo.ResultsWe showed that YAP translocates into the nucleus in the endometrium of cattle and mice during early pregnancy. Mechanistically, YAP acts as a mediator of ECM rigidity and cell density, which requires the actomyosin cytoskeleton and is partially dependent on the Hippo pathway. Furthermore, we found that the soluble factor IFNτ, which is a ruminant pregnancy recognition factor, also induced activation of YAP by reducing the expression of miR‐16a.ConclusionsThis study revealed that activation of YAP is necessary for early pregnancy in bovines because it induced cell proliferation and established an immunosuppressive local environment that allowed conceptus implantation into the uterine epithelium.     

SETD2 epidermal deficiency promotes cutaneous wound healing via activation of AKT/mTOR Signalling

ObjectivesCutaneous wound healing is one of the major medical problems worldwide. Epigenetic modifiers have been identified as important players in skin development, homeostasis and wound repair. SET domain–containing 2 (SETD2) is the only known histone H3K36 tri‐methylase; however, its role in skin wound healing remains unclear.Materials and MethodsTo elucidate the biological role of SETD2 in wound healing, conditional gene targeting was used to generate epidermis‐specific Setd2‐deficient mice. Wound‐healing experiments were performed on the backs of mice, and injured skin tissues were collected and analysed by haematoxylin and eosin (H&E) and immunohistochemical staining. In vitro, CCK8 and scratch wound‐healing assays were performed on Setd2‐knockdown and Setd2‐overexpression human immortalized keratinocyte cell line (HaCaT). In addition, RNA‐seq and H3K36me3 ChIP‐seq analyses were performed to identify the dysregulated genes modulated by SETD2. Finally, the results were validated in functional rescue experiments using AKT and mTOR inhibitors (MK2206 and rapamycin).ResultsEpidermis‐specific Setd2‐deficient mice were successfully established, and SETD2 deficiency resulted in accelerated re‐epithelialization during cutaneous wound healing by promoting keratinocyte proliferation and migration. Furthermore, the loss of SETD2 enhanced the scratch closure and proliferation of keratinocytes in vitro. Mechanistically, the deletion of Setd2 resulted in the activation of AKT/mTOR signalling pathway, while the pharmacological inhibition of AKT and mTOR with MK2206 and rapamycin, respectively, delayed wound closure.ConclusionsOur results showed that SETD2 loss promoted cutaneous wound healing via the activation of AKT/mTOR signalling.     

皖北石灰岩山地植被对地表节肢动物组成及多样性的影响

调查皖北石灰岩山地退化生态系统不同植被恢复类型地表节肢动物群落组成、类群多样性以及功能群组成,揭示退化生态系统植被恢复进程中土壤地表节肢动物群多样性变化规律及其影响因素,为石灰岩山地植被恢复成效评价提供科学依据。采用陷阱法对皖北石灰岩山地侧柏+构树混交林、酸枣+牡荆灌丛和荩草+牡荆草灌丛样地地表节肢动物群落组成、多样性以及功能群进行调查。共采节肢动物个体数11601,隶属8纲14目44科。酸枣+牡荆灌丛样地采集到节肢动物37科,占所有类群的84.1%,荩草+牡荆草灌丛和侧柏+构树混交林采集到土壤节肢动物类群为35和26科,分别占总科数的79.6%和59.1%。在目的分类单元下,直翅目、等足目和鞘翅目类群相对多度较高,而科的分类单元下,潮虫科、金龟甲科、蚁科和蟋蟀科为皖北石灰岩山地优势地表节肢动物类群。酸枣+牡荆灌丛节肢动物类群丰富度和荩草+牡荆草灌丛多样性指数最高,侧柏+构树混交林两者均最低。3个样地地表节肢动物营养功能群均以植食性为主。不同植被恢复类型间群落相似性也有变化,酸枣+牡荆灌丛和荩草+牡荆草灌丛间相似性较高,而侧柏+构树混交林与其他2种类型之间相似度均较低。研究结果表明石灰岩山地生境不同植被群落组成、数量和结构及其驱动形成的土壤理化特性、表层的凋落物数量、质量和微生境条件的变异,引起地表节肢动物群落组成、结构和多样性和营养功能群的不同。