Mutation of Basic Residues R283, R286, and K288 in the Matrix Protein of Newcastle Disease Virus Attenuates Viral Replication and Pathogenicity

The matrix (M) protein of Newcastle disease virus (NDV) contains large numbers of unevenly distributed basic residues, but the precise function of most basic residues in the M protein remains enigmatic. We previously demonstrated that the C-terminus (aa 264–313) of M protein interacted with the extra-terminal (ET) domain of chicken bromodomain-containing protein 2 (chBRD2), which promoted NDV replication by downregulating chBRD2 expression and facilitating viral RNA synthesis and transcription. However, the key amino acid sites determining M’s interaction with chBRD2/ET and their roles in the replication and pathogenicity of NDV are not known. In this study, three basic residues—R283, R286, and K288—in the NDV M protein were verified to be responsible for its interaction with chBRD2/ET. In addition, mutation of these basic residues (R283A/R286A/K288A) in the M protein changed its electrostatic pattern and abrogated the decreased expression of endogenic chBRD2. Moreover, a recombinant virus harboring these mutations resulted in a pathotype change of NDV and attenuated viral replication and pathogenicity in chickens due to the decreased viral RNA synthesis and transcription. Our findings therefore provide a better understanding of the crucial biological functions of M’s basic residues and also aid in understanding the poorly understood pathogenesis of NDV

Upregulated α-actinin-1 impairs endometrial epithelial cell adhesion by downregulating NEBL in recurrent implantation failure

Summary: Poor endometrial receptivity results in embryo implantation failure. Acquisition of endometrial receptivity involves substantial structural alterations in the cytoskeleton and plasma membrane of epithelial cells, which facilitate embryo adhesion. However, the underlying molecular mechanism remains largely unknown. In this study, we identified that α-actinin-1 (ACTN1) was significantly downregulated in the mid-secretory phase of the endometrium compared with other phases; however, ACTN1 significantly increased in women with recurrent implantation failure (RIF). In Ishikawa and human endometrial epithelial cells (HEECs), ACTN1 overexpression significantly decreased NEBL levels, enhanced F-actin fiber levels, and caused a notable impairment in blastocyst adhesion, which mimicked the process of embryo adhesion. However, NEBL overexpression notably restored adhesion. Moreover, NEBL expression was reduced in patients with RIF compared with that in controls. Finally, our data showed that ACTN1 upregulation impaired endometrial receptivity in women with RIF, possibly by regulating NEBL expression and subsequent cell-adhesion capability

Schiff Base Compounds as Fluorescent Probes for the Highly Sensitive and Selective Detection of Al³⁺ Ions

Two new Schiff base fluorescent probes (L and S) were designed for selectively detecting Al3+ ions in aqueous medium. Structural characterization of the purely synthesized compounds was acquired by IR, 1H NMR and 13C NMR. Moreover, their photochromic and fluorescent behaviors have been investigated systematically by UV–Vis absorption and fluorescence spectra. The two probes have both high selectivity and sensitivity toward Al3+ ions in aqueous medium. The 2:1 stoichiometry between the Al3+ and probes was verified by Job’s plot. Moreover, the limits of detection (LOD) for Al3+ by L and S were 1.98 × 10−8 and 4.79 × 10−8 mol/L, respectively, which was much lower than most previously reported probes. The possible recognition mechanism was that the metal ions would complex with Schiff base probes because of the prevalence of the species optimal for complex formation, inhibiting the structural isomerization of conjugated double bonds (-C=N-), inhibiting the proton transfer process in the excited state of the molecules and resulting in changes of its color and fluorescence behavior. Furthermore, the probes will have potential applications for selectively, detecting Al3+ ions in the environmental system with high accuracy and providing a new strategy for the design and synthesis of multi-functional sensors

Three-Dimensional Urban Expansion Analysis of Valley-Type Cities: A Case Study of Chengguan District, Lanzhou, China

The development of cities in the vertical dimension is important in valley-type cities where physical growth is limited by terrain. However, little research has focused on three-dimensional urban expansion of valley-type cities. Lanzhou is a typical valley-type city in China and Chengguan District is the core area of Lanzhou City. This research is aimed at understanding the development of valley-type cities through the analysis of the three-dimensional urban expansion of Lanzhou Chengguan District and providing a reference for urban planning. We extracted five periods of architectural contours and height information between 1975 to 2018 with the support of multi-source remote sensing and network data. We used overlay analysis and mathematical statistical methods to analyze urban horizontal expansion and used the building density, floor area ratio, vertical expansion speed, fluctuation degree, and skyline to analyze urban vertical expansion. We found that the mode of horizontal expansion of Chengguan District shifted from adjacency to enclave through mountain area reclamation. The area with the fastest vertical expansion speed first appeared in the horizontal expansion completed area, and then in both the rapid horizontal expansion area and in the horizontal expansion completed area. Before 2007, the speed of horizontal expansion increased and reached its peak while the vertical expansion speed was relatively stable. After that, the former decreased, and the vertical expansion increased rapidly and dominated the urban development. The vertical expansion of the valley-type city gradually dominates urban development. Urban planning should consider the three-dimensional expansion, especially in the vertical dimension

Nanotexture and crystal phase regulation for synergistic enhancement in re-endothelialization on medical pure titanium surface

Re-endothelialization has been recognized as a promising strategy to address the tissue hyperplasia and subsequent restenosis which are major complications associated with vascular implant/interventional titanium devices. However, the uncontrollable over-proliferation of smooth muscle cells (SMCs) limits the clinical application of numerous modified strategies. Herein, a novel modified strategy involving with a two-step anodic oxidation and annealing treatment was proposed to achieve rapid re-endothelialization function regulated by regular honeycomb nanotexture and specific anatase phase on the titanium surface. Theoretical calculation revealed that the presence of nanotexture reduced the polar component of surface energy, while the generation of anatase significantly enhanced the polar component and total surface energy. Meanwhile, the modified surface with regular nanotexture and anatase phase produced positive effect on the expression of CD31, VE-Cadherin and down-regulated α-SMA proteins expression, indicating excellent capacity of pro-endothelial regeneration and inhibition of SMCs proliferation and migration. One-month in vivo implantation in rabbit carotid arteries further confirmed that modified tube implant surface effectively accelerated confluent endothelial monolayer formation and promoted native-like endothelium tissue regeneration. By contrast, original titanium tube implant induced a disorganized tissue proliferation in the lumen with a high risk of restenosis. Collectively, this study opens us an alternative route to achieve the function that selectively promotes endothelial cells (ECs) growth and suppresses SMCs on the medical titanium surface, which has a great potential in facilitating re-endothelialization on the surface of blood-contacting titanium implant

Cell-free fat extract improves ovarian function and fertility in mice with premature ovarian insufficiency

Abstract Background Premature ovarian insufficiency (POI) is a refractory disease that seriously affects the reproductive health of women and is increasing in incidence and prevalence globally. There is enormous demand to improve fertility in women with POI, while there is still lack of effective therapeutic methods in clinic. Cell-free fat extract (CEFFE) has been reported to contain thousands of active proteins which possess the ability to promote tissue repair in other diseases. In our study, we aimed to observe the efficacy and biosecurity of CEFFE on the repair of ovarian function and fertility of mice with POI and further explore the underlying mechanism. Methods In vivo, POI mice model, established by cyclophosphamide (CTX, 120 mg/kg) and busulfan (BUS, 12 mg/kg), was treated with CEFFE via the tail vein every two days for 2 weeks. Then, the weight of ovaries, estrous cycle and follicle count by H&E staining were measured. The content of AMH, E2 and FSH in serum was measured by Enzyme-linked immunosorbent assay. Fertility was evaluated by the number of oocytes retrieved, the development of embryos in vitro and the litter size. Biosecurity of parent mice and their pups were examined by body mass and visceral index. The proliferation and apoptosis of cells in ovaries were examined by immunohistochemistry and transmission electron microscopy. Furthermore, the mRNA-Seq of mouse ovarian granulosa cells was performed to explore underlying mechanism of CEFFE. In vitro, KGN cell line and human primary ovarian granulosa cells (hGCs) were treated with 250 μM CTX for 48 h with/without CEFFE. The proliferative ability of cells was detected by cell counting kit-8 assay (CCK-8) and EDU test; the apoptosis of cells was detected by TUNEL and flow cytometry. Results CEFFE recovered the content of AMH, E2 and FSH in serum, increased the number of follicles and the retrieved oocytes of POI mice (P < 0.05). CEFFE contributed to the development of embryos and improved the litter size of POI mice (P < 0.05). There was no side effect of CEFFE on parent mice and their pups. CEFFE contributed to the proliferation and inhibited the apoptosis of mouse granulosa cells in ovary, as well as in human ovarian granulosa cells (including KGN cell line and hGCs) (P < 0.05). Conclusions The treatment of CEFFE inhibited the apoptosis of granulosa cells and contributed to the recovery of ovarian function, as well as the fertility of mice with POI