Differential expression of VGLUT3 in laboratory mouse strains: Impact on drug‐induced hyperlocomotion and anxiety‐related behaviors

The atypical vesicular glutamate transporter VGLUT3 is present in subpopulations of GABAergic interneurons in the cortex and the hippocampus, in subgroups of serotoninergic neurons in raphe nuclei, and in cholinergic interneurons in the striatum. C56BL/6N mice that no longer express VGLUT3 (VGLUT3^?/?) display anxiety‐associated phenotype, increased spontaneous and cocaine‐induced locomotor activity and decreased haloperidol‐induced catalepsy. Inbred mouse strains differ markedly in their sensitivity to anxiety and behavioral responses elicited by drugs. The purpose of this study was to investigate strain differences in VGLUT3 expression levels and its potential correlates with anxiety and reward‐guided behaviors. Five inbred mouse lines were chosen according to their contrasted anxiety and drugs sensitivity: C57BL/6N, C3H/HeN, DBA/2J, 129/Sv, and BALB/c. VGLUT3 protein expression was measured in different brain areas involved in reward or mood regulation (such as the striatum, the hippocampus, and raphe nuclei) and genetic variations in Slc17a8, the gene encoding for VGLUT3, have been explored. These five inbred mouse strains express very different levels of VGLUT3, which cannot be attributed to the genetic variation of the Slc17a8 locus. Furthermore, mice behavior in the open field, elevated plus maze, spontaneous‐ and cocaine‐induced locomotor was highly heterogeneous and only partially correlated to VGLUT3 levels. These data highlight the fact that one single gene polymorphism could not account for VGLUT3 expression variations, and that region specific VGLUT3 expression level variations might play a key role in the modulation of discrete behaviors.     

(Pro)renin receptor accelerates development of sarcopenia via activation of Wnt/YAP signaling axis

To extend life expectancy and ensure healthy aging, it is crucial to prevent and minimize age‐induced skeletal muscle atrophy, also known as sarcopenia. However, the disease's molecular mechanism remains unclear. The age‐related Wnt/β‐catenin signaling pathway has been recently shown to be activated by the (pro)renin receptor ((P)RR). We report here that (P)RR expression was increased in the atrophied skeletal muscles of aged mice and humans. Therefore, we developed a gain‐of‐function model of age‐related sarcopenia via transgenic expression of (P)RR under control of the CAG promoter. Consistent with our hypothesis, (P)RR‐Tg mice died early and exhibited muscle atrophy with histological features of sarcopenia. Moreover, Wnt/β‐catenin signaling was activated and the regenerative capacity of muscle progenitor cells after cardiotoxin injury was impaired due to cell fusion failure in (P)RR‐Tg mice. In vitro forced expression of (P)RR protein in C2C12 myoblast cells suppressed myotube formation by activating Wnt/β‐catenin signaling. Administration of Dickkopf‐related protein 1, an inhibitor of Wnt/β‐catenin signaling, and anti‐(P)RR neutralizing antibody, which inhibits binding of (P)RR to the Wnt receptor, significantly improved sarcopenia in (P)RR‐Tg mice. Furthermore, the use of anti‐(P)RR neutralizing antibodies significantly improved the regenerative ability of skeletal muscle in aged mice. Finally, we show that Yes‐associated protein (YAP) signaling, which is coordinately regulated by Wnt/β‐catenin, contributed to the development of (P)RR‐induced sarcopenia. The present study demonstrates the use of (P)RR‐Tg mice as a novel sarcopenia model, and shows that (P)RR‐Wnt‐YAP signaling plays a pivotal role in the pathogenesis of this disease.     

Population and Single-Cell Analysis of Human Cardiogenesis Reveals Unique LGR5 Ventricular Progenitors in Embryonic Outflow Tract

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Hsa_circ_0002577 promotes endometrial carcinoma progression via regulating miR-197/CTNND1 axis and activating Wnt/β-catenin pathway

Circular RNA (circRNA) is involved in a wide range of life processes including tumorigenesis. However, the molecular mechanisms of circRNA in endometrial carcinoma (EC) carcinogenesis remain unclear. In the present study, we aimed to investigate the potential modulation of hsa_circ_0002577 on EC progression. Here, we showed that hsa_circ_0002577 expression was significantly upregulated in EC tissues, and high hsa_circ_0002577 expression was associated with advanced FIGO stage, lymph node metastasis, and poor overall survival rate of EC patients. In function assays, we demonstrated that hsa_circ_0002577 knockdown significantly reduced EC cells proliferation, migration, invasion ability in vitro and decreased tumor growth in vivo. In mechanism study, we revealed that hsa_circ_0002577 might act as a sponge for miR-197, and CTNND1 was revealed to be a target gene of miR-197. In addition, we revealed that the oncogenic effects of hsa_circ_0002577 were attributed to the regulation of miR-197/CTNND1/Wnt/β-catenin axis. Taken together, we indicated that hsa_circ_0002577 could play critical functions by hsa_circ_0002577/miR-197/CTNND1/Wnt/β-catenin signaling pathway, which served as a novel therapeutic application for EC treatment.     

Bioimaging of multiple elements by high‐resolution LA‐ICP‐MS reveals altered distribution of mineral elements in the nodes of rice mutants

Inter‐vascular transfer in rice (Oryza sativa) nodes is required for delivering mineral elements to developing tissues, which is mediated by various transporters in the nodes. However, the effect of these transporters on distribution of mineral elements in the nodes at a cellular level is still unknown. Here, we established a protocol for bioimaging of multiple elements at a cellular level in rice node by laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS), and compared the mineral distribution profile between wild‐type (WT) rice and mutants. Both relative comparison of mineral distribution normalized by endogenous ¹³C and quantitative analysis using spiked standards combined with soft ablation gave valid results. Overall, macro‐nutrients such as K and Mg were accumulated more in the phloem region, while micro‐nutrients such as Fe and Zn were highly accumulated at the inter‐vascular tissues of the node. In mutants of nodal Zn transporter OsHMA2, Zn localization pattern in the node tissues did not differ from that of WT; however, Zn accumulation in the inter‐vascular tissues was lower in uppermost node I but higher in the third upper node III compared with the WT. In contrast, Si deposition in the mutants of three nodal Si transporters Lsi2, Lsi3 and Lsi6 showed different patterns, which are consistent with the localization of these transporters. This improved LA‐ICP‐MS analysis combined with functional characterization of transporters will provide further insight into mineral element distribution mechanisms in rice and other plant species.     

Structural Characterization of Biomolecules through Atomistic Simulations Guided by DEER Measurements

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主要组织相容性复合体单倍型鸭抗原处理相关转运体单抗的制备

目的制备鸭抗原处理相关转运体(TAP)特异性单抗,为深入利用实验鸭开展免疫学研究提供实验材料。方法利用大肠埃希菌诱导表达主要组织相容性复合体(MHC)单倍型HBW-SPF鸭TAP蛋白肽结合区片段,表达产物经镍柱纯化后免疫BALB/c小鼠,采用ELISA技术筛选特异性单抗分泌杂交瘤细胞株。将阳性细胞株制备小鼠腹水,作为一抗,与多次截短表达TAP蛋白肽结合区进行蛋白免疫印迹试验,鉴定单抗针对的抗原表位。通过间接免疫荧光试验比较该单抗对实验鸭和鸡外周血淋巴细胞的反应性,利用免疫组织化学技术检测对SPF鸡、SPF鸭、鹌鹑、鹅和SPF猪的特异性。结果获得一株鸭TAP单抗1A6,抗原表位位于²⁹⁷NARHQMLQQAVLDATAGTGMVVQEAI³²²,对鸡和鸭外周血淋巴细胞具有免疫荧光反应性;在鸡和鸭的肠黏膜固有层检测到大量特异性信号,在猪、鹌鹑和鹅没有检测到信号。结论获得了一株具有鸡和鸭反应性的抗原转运相关体特异性的单抗,可运用于禽类实验动物在禽病学和禽免疫学方面的研究。     

马铃薯硝态氮转运蛋白基因的克隆及表达分析

该研究以马铃薯双单倍体‘DM’为材料,克隆到高亲和性硝态氮转运蛋白基因StNRT2.1的全长cDNA(JGI登录号PGSC0003DMT400002924),并对其进行表达模式和生物信息学分析,为深入探索StNRT2.1基因的生物学功能以及提高马铃薯对氮素的利用效率奠定理论基础。结果表明:(1)通过同源克隆与PCR扩增获得StNRT2.1基因cDNA全长片段,并构建pCEGFP-StNRT2.1表达载体;测序结果显示其实际所编码的蛋白质序列与数据库中目的基因蛋白质序列完全一致,表明成功克隆到StNRT2.1基因且未出现错义突变。(2)StNRT2.1基因位于马铃薯第11号染色体,cDNA序列全长1 593 bp,编码530个氨基酸,预测蛋白相对分子质量约为57.60 kD,理论等电点为9.36。(3)生物信息学分析显示,StNRT2.1由20种氨基酸组成,其中甘氨酸(Gly)所占比例最多,达到10.8%,并且主要由228个α-螺旋、27个β-折叠、87个延伸链和188个无规则卷曲构成;StNRT2.1存在功能保守结构MFS_1(PF07690)和12个跨膜螺旋结构域,且N端和C端均位于细胞膜内; StNRT2.1位于质膜上且不具有信号肽,可能为非分泌型膜蛋白。(4)以氮充足(7.5 mmol/L)水平作为对照,马铃薯幼苗经无氮(0 mmol/L)和低氮(0.75 mmol/L)处理3周后呈现出叶片发黄及植株矮化等明显表型差异。(5)qRT-PCR结果显示,在无氮条件下,马铃薯根组织中StNRT2.1基因表达量升高3.98倍,说明StNRT2.1可能为诱导型高亲和转运蛋白。     

A Protein Disulfide Isomerase Controls Neuronal Migration through Regulation of Wnt Secretion

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