Different effects of 25-kDa amelogenin on the proliferation, attachment and migration of various periodontal cells

Previous studies have assumed that amelogenin is responsible for the therapeutic effect of the enamel matrix derivative (EMD) in periodontal tissue healing and regeneration. However, it is difficult to confirm this hypothesis because both the EMD and the amelogenins are complex mixtures of multiple proteins. Further adding to the difficulties is the fact that periodontal tissue regeneration involves various types of cells and a sequence of associated cellular events including the attachment, migration and proliferation of various cells. In this study, we investigated the potential effect of a 25-kDa recombinant porcine amelogenin (rPAm) on primarily cultured periodontal ligament fibroblasts (PDLF), gingival fibroblasts (GF) and gingival epithelial cells (GEC). The cells were treated with 25-kDa recombinant porcine amelogenin at a concentration of 10 μg/mL. We found that rPAm significantly promoted the proliferation and migration of PDLF, but not their adhesion. Similarly, the proliferation and adhesion of GF were significantly enhanced by treatment with rPAm, while migration was greatly inhibited. Interestingly, this recombinant protein inhibited the growth rate, cell adhesion and migration of GEC. These data suggest that rPAm may play an essential role in periodontal regeneration through the activation of periodontal fibroblasts and inhibition of the cellular behaviors of gingival epithelial cells.     

Characterizing the functional significance of the neonatal rat vibrissae prior to the onset of whisking

The present series of experiments assessed how information from the whiskers controls and modulates infant rat behavior during early learning and attachment. Passive vibrissal stimulation can elicit behavioral activity in pups throughout the first two postnatal weeks, although orienting to the source of stimulation is evident only after ontogenetic emergence of whisking. In addition, while pups were capable of demonstrating learning in a classical conditioning paradigm pairing vibrissa stimulation with electric shock, no corresponding changes were detected in the anatomy of the barrel cortex as determined by cytochrome oxidase (CO) staining. Finally, the role of whiskers in a more naturalistic setting was determined in postnatal day (PN)3-5 and PN11-12 pups. Our results showed that both nipple attachment and huddling were disrupted in whisker-clipped PN3-5 pups but only marginally altered in PN11-12 pups. Together, these results suggest that the neonatal whisker system is behaviorally functional and relevant for normal mother-infant interactions, though it lacks the sophistication of a mature whisker system that evokes very specific and directed responses.     

Factors affecting the adhesion and uptake of an oculo-genital strain of Chlamydia trachomatis to McCoy cells

Abstract We have studied adhesion and uptake of C. trachomatis serovar E in McCoy cells under various infection conditions. Adhesion and uptake of chlamydiae was completed about 3 h after the initiation of stationary infection at 37°C, but ingestion of cell membrane-attached organisms was finished within 0.5 h at 37°C. Reincubated chlamydiae, not attached after 3 h at 37°C, attached readily to fresh McCoy cell monolayers, but to a lesser extent than the original inoculum. Our results indicate that the lack of further attachment after 3 h incubation at 37°C under stationary infection conditions has complex causes, involving both host cell and parasite. Centrifugation did not affect the uptake of chlamydiae already bound to the cell membrane, suggesting that the uptake phase of C. trachomatis serovar E by McCoy cells is unaffected by centrifugation.     

Early stress predicts age at menarche and first birth,adult attachment,and expected lifespan

Life history theory suggests that in risky and uncertain environments the optimal reproductive strategy is to reproduce early in order to maximize the probability of leaving any descendants at all. The fact that early menarche facilitates early reproduction provides an adaptationist rationale for our first two hypotheses: that women who experience more risky and uncertain environments early in life would have (1) earlier menarche and (2) earlier first births than women who experience less stress at an early age. Attachment theory and research provide the rationale for our second two hypotheses: that the subjective early experience of risky and uncertain environments (insecurity) is (3) part of an evolved mechanism for entraining alternative reproductive strategies contingent on environmental risk and uncertainty and (4) reflected in expected lifespan. Evidence from our pilot study of 100 women attending antenatal clinics at a large metropolitan hospital is consistent with all four hypotheses: Women reporting more troubled family relations early in life had earlier menarche, earlier first birth, were more likely to identify with insecure adult attachment styles, and expected shorter lifespans. Multivariate analyses show that early stress directly affected age at menarche and first birth, affected adult attachment in interaction with expected lifespan, but had no effect on expected lifespan, where its original effect was taken over by interactions between age at menarche and adult attachment as well as age at first birth and adult attachment. We discuss our results in terms of the need to combine evolutionary and developmental perspectives and the relation between early stress in general and father absence in particular. This work was supported by The University of Melbourne Department of Obstetrics and Gynaecology. James S. Chisholm is Professor in the School of Anatomy and Human Biology at the University of Western Australia. He is an anthropologist whose interests lie in the fields of human behavioral biology, evolutionary ecology, life history theory, and parental investment theory, where he focuses on infant social-emotional development, the development of reproductive strategies, and the integration of evolutionary, developmental, and cultural psychology and public health. Julie A. Quinlivan is Associate Professor in Obstetrics and Gynaecology at the University of Melbourne and Head of the Maternity Care Program at the Royal Women’s Hospital, Melbourne. Her interests are teenage pregnancy, domestic violence, child abuse prevention, and high-risk pregnancy. Rodney W. Petersen is Senior Lecturer in Obstetrics and Gynaecology at the University of Melbourne and Senior Consultant in Obstetrics and Gynaecology at the Royal Women’s Hospital and Sunshine Hospital in Melbourne. His interests are in psychosocial aspects of women’s health and cancer. David A. Coall is a Ph.D. student in the School of Anatomy and Human Biology at the University of Western Australia. His main interest lies in the application of evolutionary theory within an epidemiological framework. He is currently working on the synthesis of life history theory, parental investment theory, and parent-offspring conflict theory in exploring factors that influence variation in human birth weight and placental weight.     

中华绒螯蟹胚胎附着系统的结构和形成机制

利用透射电镜和扫描电镜技术研究了中华绒螯蟹(Eriocheir sinensis)胚胎附着系统的结构及形成机制。中华绒螯蟹受精卵附着在雌性腹肢内肢的携卵刚毛上。该附着系统由三个连续部分组成:卵膜、卵柄和被膜,后者覆盖在携卵刚毛的绒毛上。研究结果显示:中华绒螯蟹的成熟胚胎由三层明显的卵膜组成,即E1、E2和E3层,但胚胎附着系统的卵柄及被膜仅为外层(E1)。卵巢中成熟卵的卵膜仅由E1层组成,E1分为两个亚层(E1a′、E1b′)。胚胎附着系统的形成与雌蟹的行为、腹肢粘液腺分泌的粘液、卵膜的超微结构及各层的变化有关。受精卵刚从生殖孔中排出时,卵膜(E1a′、E1b′)并不能直接粘附在携卵绒毛上。产卵后不久,雌蟹腹肢粘液腺分泌粘液的量增多,E1a′、E1b′的结构发生变化,表现为边界模糊,卵膜出现很强的粘性。在产卵后约60min E1层又明显分为两个亚层(E1a、E1b),同时排卵后雌蟹腹部的携卵绒毛不断地运动,这种运动促使携卵绒毛外的被膜形成。随着E1层亚结构的变化,E2层也开始形成,当E1新的两个亚层出现时,部分区域的E1层与E2层发生分离,卵柄开始形成,并牢固地附着在携卵绒毛上。被膜、卵柄与卵膜最外层的结构相同,均由E1层构成[动物学报51(5):852-861,2005]。     

盐度对企鹅珍珠贝足丝分泌的影响

企鹅珍珠贝（Pteria penguin）是生产附壳珍珠的大型海水经济贝类,其依靠强壮的足丝将自身固定在硬质基底上,抵抗水流的冲击和抵御被捕食等。足丝分泌和足丝的形状很容易受到环境的影响,本实验采用盐度30为低盐度组、盐度35为中盐度组和盐度40为高盐度组,研究这3种盐度对企鹅珍珠贝足丝分泌、足丝直径和足丝拉力的影响,通过单因素方差分析法（LSD法）分析这三个足丝相关指标在3种盐度组间是否存在显著性差异。结果显示,3种盐度下企鹅珍珠贝足丝附着率无显著差异,但在整个实验周期72 h内,中盐度组的足丝分泌总数为（48.7 ± 15.1）根,显著高于低盐度组的（24.7 ± 5.0）根和高盐度组的（13.3 ± 1.5）根。在实验的前6 h内,中盐度组的足丝首次附着率显著高于低盐度组和高盐度组（P < 0.05）,但在后续的12 h、18 h、30 h、42 h、54 h和66 h这6个时间点,3个盐度组的足丝首次附着率均无显著性差异。足丝直径未受盐度变化的影响,但盐度对足丝拉力具有显著影响,中盐度组的足丝拉力显著高于低盐度组和高盐度组（P < 0.05）。上述结果表明,企鹅珍珠贝为适应一定范围内盐度的改变,会在短时间内通过抑制足丝分泌来减少能量消耗,随着对环境的适应足丝分泌会恢复。盐度影响足丝分泌且对足丝拉力影响显著,但对足丝直径无明显影响。本研究可以为企鹅珍珠贝养殖及珍珠插核培育提供理论基础。     

The Habc Domain of the SNARE Vam3 Interacts with the HOPS Tethering Complex to Facilitate Vacuole Fusion

Membrane fusion at vacuoles requires a consecutive action of the HOPS tethering complex, which is recruited by the Rab GTPase Ypt7, and vacuolar SNAREs to drive membrane fusion. It is assumed that the Sec1/Munc18-like Vps33 within the HOPS complex is largely responsible for SNARE chaperoning. Here, we present direct evidence for HOPS binding to SNAREs and the H_abc domain of the Vam3 SNARE protein, which may explain its function during fusion. We show that HOPS interacts strongly with the Vam3 H_abc domain, assembled Q-SNAREs, and the R-SNARE Ykt6, but not the Q-SNARE Vti1 or the Vam3 SNARE domain. Electron microscopy combined with Nanogold labeling reveals that the binding sites for vacuolar SNAREs and the H_abc domain are located in the large head of the HOPS complex, where Vps16 and Vps33 have been identified before. Competition experiments suggest that HOPS bound to the H_abc domain can still interact with assembled Q-SNAREs, whereas Q-SNARE binding prevents recognition of the H_abc domain. In agreement, membranes carrying Vam3ΔH_abc fuse poorly unless an excess of HOPS is provided. These data suggest that the H_abc domain of Vam3 facilitates the assembly of the HOPS/SNARE machinery at fusion sites and thus supports efficient membrane fusion.     

Gene‐environment interaction influences attachment‐like style in mice

Attachment styles are established soon after birth and form the basis for a healthy psychological life during adulthood. Here, we investigated whether genetic background (i.e. isogenic strains: C57BL/6N and BALB/c) and parent‐of‐origin (i.e. reciprocal hybrids) epigenetic effects influence attachment‐like styles in mice. We discovered that a specific genetic and epigenetic assortment exerts a role on the development of a secure or insecure attachment‐like style. In particular, when biological mothers raise their pups, the attachment‐like style is mainly secure, independently of the genetic background. However, when foster mothers raise pups, the attachment‐like style can be either secure or insecure, depending on the particular genetic background, and this effect is paternally transmitted. Finally, we observed that secure attachment‐like in mice leads to greater sociability during adulthood, while insecure attachment‐like leads to reduced sociability. Our study sheds light on gene‐environment interactions that shape the attachment‐like style early in development and pave the way for a healthy psychological life.     

A Computationally Guided Protein-Interaction Screen Uncovers Coiled-Coil Interactions Involved in Vesicular Trafficking

Mapping protein-protein interactions at a domain or motif level can provide structural annotation of the interactome. The α-helical coiled coil is among the most common protein-interaction motifs, and proteins predicted to contain coiled coils participate in diverse biological processes. Here, we introduce a combined computational/experimental screening strategy that we used to uncover coiled-coil interactions among proteins involved in vesicular trafficking in Saccharomyces cerevisiae. A number of coiled-coil complexes have already been identified and reported to play important roles in this important biological process. We identify additional examples of coiled coils that can form physical associations. The computational strategy used to prioritize coiled-coil candidates for testing dramatically improved the efficiency of discovery in a large experimental screen. As assessed by comprehensive yeast two-hybrid assays, computational prefiltering retained 90% of positive interacting pairs and eliminated > 60% of negatives from a set of interaction candidates. The coiled-coil-mediated interaction network elucidated using the combined computational/experimental approach comprises 80 coiled-coil associations between 58 protein pairs, among which 21 protein interactions have not been previously reported in interaction databases and 26 interactions were previously known at the protein level but have now been localized to the coiled-coil motif. The coiled-coil-mediated interactions were specific rather than promiscuous, and many interactions could be recapitulated in a green fluorescent protein complementation assay. Our method provides an efficient route to discovering new coiled-coil interactions and uncovers a number of associations that may have functional significance for vesicular trafficking.