Distribution and characteristics of telocytes as nurse cells in the architectural organization of engineered heart tissues

Interstitial Cajal-like cells are a distinct type of interstitial cell with a wide distribution in mammalian organs and tissues,and have been given the name"telocytes".Recent studies have demonstrated the potential roles of telocytes in heart development,renewal,and repair.However,further research on the functions of telocytes is limited by the complicated in vivo environment.This study was designed to construct engineered heart tissue(EHT)as a three-dimensional model in vitro to better understand the role of telocytes in the architectural organization of the myocardium.EHTs were constructed by seeding neonatal cardiomyocytes in collagen/Matrigel scaffolds followed by culture under persistent static stretch.Telocytes in EHTs were identified by histology,toluidine blue staining,immunofluorescence,and transmission electron microscopy.The results from histology and toluidine blue staining demonstrated widespread putative telocytes with compact toluidine blue-stained nuclei,which were located around cardiomyocytes.Prolongations from the cell bodies showed a characteristic dichotomous branching pattern and formed networks in EHTs.Immunofluorescence revealed positive staining of telocytes for CD34 and vimentin with typical moniliform prolongations.A series of electron microscopy images further showed that typical telocytes embraced the cardiomyocytes with their long prolongations and exhibited a marked appearance of nursing cardiomyocytes during the construction of EHTs.This finding highlights the great importance of telocytes in the architectural organization of EHTs.It also suggests that EHT is an appropriate physical and pathological model system in vitro to study the roles of telocytes during heart development and regeneration.     

Immunogenicity analysis following human immunodeficiency virus recombinant DNA and recombinant vaccinia virus Tian Tan prime-boost immunization

This study assessed and compared the immunogenicity of various immunization strategies in mice using combinations of recombinant DNA(pCCMp24) and recombinant attenuated vaccinia virus Tian Tan(rddVTT-CCMp24).Intramuscular immunization was performed on days 0(prime) and 21(boost).The immunogenicity of the vaccine schedules was determined by measuring human immunodeficiency virus(HIV)-specific binding antibody levels and cytokine(interleukin-2 and interleukin-4) concentrations in peripheral blood,analyzing lymphocyte proliferation capacity against HIV epitopes and CD4 + /CD8 + cell ratio,and monitoring interferon-gamma levels at different times post-immunization.The results showed that pCCMp24,rddVTT-CCMp24 and their prime-boost immunization induced humoral and cellular immune responses.The pCCMp24/rddVTT-CCMp24 immunization strategy increased CD8 + T cells and induced more IFN-γ-secreting cells compared with single-shot rDNA.The prime-boost immunization strategy also induced the generation of cellular immunological memory to HIV epitope peptides.These results demonstrated that prime-boost immunization with rDNA and rddVTT-CCMp24 had a tendency to induce greater cellular immune response than single-shot vaccinations,especially IFN-γ response,providing a basis for further studies.     

Biomechanism of impact resistance in the woodpecker’s head and its application

The woodpecker does not suffer head/eye impact injuries while drumming on a tree trunk with high acceleration(more than 1000×g) and high frequency.The mechanism that protects the woodpecker’s head has aroused the interest of ornithologists,biologists and scientists in the areas of mechanical engineering,material science and electronics engineering.This article reviews the literature on the biomechanisms and materials responsible for protecting the woodpecker from head impact injury and their applications in engineering and human protection.     

Adaptation to visual stimulation modifies the burst firing property of V1 neurons

The mean firing rate of visual cortical neurons is reduced after prolonged visual stimulation, but the underlying process by which this occurs as well as the biological significance of this phenomenon remains unknown. Computational neuroscience studies indicate that high-frequency bursts in stimulus-driven responses can be transmitted across synapses more reliably than isolated spikes, and thus may carry accurate stimulus-related information. Our research examined whether or not adaptation affects the burst firing property of visual cortical neurons by examining changes in the burst firing changes of V1 neurons during adaptation to the preferred visual stimulus. The results show that adaptation to prolonged visual stimulation significantly decreased burst frequency (bursts/s) and burst length (spikes/burst), but increased burst duration and the interspike interval within bursts. These results suggest that the adaptation of V1 neurons to visual stimulation may result in a decrease of feedforward response gain but an increase of functional activities from lateral and/or feedback connections, which could lead to a reduction in the effectiveness of adapted neurons in transmitting information to its driven neurons.     

Dawn of ocular gene therapy:implications for molecular diagnosis in retinal disease

Personalized medicine aims to utilize genomic information about patients to tailor treatment.Gene replacement therapy for rare genetic disorders is perhaps the most extreme form of personalized medicine,in that the patients’ genome wholly determines their treatment regimen.Gene therapy for retinal disorders is poised to become a clinical reality.The eye is an optimal site for gene therapy due to the relative ease of precise vector delivery,immune system isolation,and availability for monitoring of any potential damage or side effects.Due to these advantages,clinical trials for gene therapy of retinal diseases are currently underway.A necessary precursor to such gene therapies is accurate molecular diagnosis of the mutation(s) underlying disease.In this review,we discuss the application of Next Generation Sequencing(NGS) to obtain such a diagnosis and identify disease causing genes,using retinal disorders as a case study.After reviewing ocular gene therapy,we discuss the application of NGS to the identification of novel Mendelian disease genes.We then compare current,array based mutation detection methods against next NGS-based methods in three retinal diseases:Leber’s Congenital Amaurosis,Retinitis Pigmentosa,and Stargardt’s disease.We conclude that next-generation sequencing based diagnosis offers several advantages over array based methods,including a higher rate of successful diagnosis and the ability to more deeply and efficiently assay a broad spectrum of mutations.However,the relative difficulty of interpreting sequence results and the development of standardized,reliable bioinformatic tools remain outstanding concerns.In this review,recent advances NGS based molecular diagnoses are discussed,as well as their implications for the development of personalized medicine.     

Rescue and Preliminary Application of a Recombinant Newcastle Disease Virus Expressing Green Fluorescent Protein Gene

Based on the complete genome sequence of Newcastle disease virus (NDV) ZJI strain, seven pairs of primers were designed to amplify a cDNA fragment for constructing the plasmid pNDV/ZJI, which contained the full-length cDNA of the NDV ZJI strain. The pNDV/ZJI, with three helper plasmids, pCIneoNP, pCIneoP and pCIneoL, were then cotransfected into BSR-T7/5 cells expressing T7 RNA polymerase. After inoculation of the transfected cell culture supernatant into embryonated chicken eggs from specific-pathogen-free (SPF) flock, an infectious NDV ZJI strain was successfully rescued. Green fluorescent protein (GFP) gene was amplified and inserted into the NDV full-length cDNA to generate a GFP-tagged recombinant plasmid pNDV/ZJIGFP. After cotransfection of the resultant plasmid and the three support plasmids into BSR-T7/5 cells, the recombinant NDV, NDV/ZJIGFP, was rescued. Specific green fluorescence was observed in BSR-T7/5 and chicken embryo fibroblast (CEF) cells 48h post-infection, indicating that the GFP gene was expressed at a relatively high level. NDV/ZJIGFP was inoculated into 10-day-old SPF chickens by oculonasal route. Four days post-infection, strong green fluorescence could be detected in the kidneys and tracheae, indicating that the recombinant GFP-tagged NDV could be a very useful tool for analysis of NDV dissemination and pathogenesis.     

Phylogenetic Analysis of Homologous Proteins Encoded by UL2 and UL23 genes of Herpesviridae

The proteins encoded by the Herpesviridae β-gene play a critical role in the replication stage of the virus.In this paper,phylogenetic analyses provided evidence that some β-gene products,such as UL2 and UL23 from HSV1,have their homologous genes in its family,and also exist in prokaryotic organisms,indicating that these viruses appear to have been assembled over evolutionary time by numerous independent events of horizontal gene transfer.     

Expression of HSV-1 ICPO Antigen Peptide in Prokaryotic Cells and Preparation of Specific Antibody

As an immediate-early protein of herpes simplex virus, infected-cell polypeptide 0 （ICP0） exhibits complicated interactions with host cells, and its regulatory function on gene expression is of great importance. Since the ICP0 encoding sequence contains many rare codons which are absent in E.coli, and ICP0 is highly unstable in prokaryotic cells, expression of entire ICP0 in prokaryotic cells has never been reported. In order to further investigate the function of ICP0, a recombinant plasmid was constructed by subcloning a cDNA fragment encoding an amino-terminal of 105 residues of the ICP0 protein into pGEX-5x-1 vector. The resulting GST-105 fusion antigen peptide was expressed with high efficiency in E.coli. Antibodies prepared after the immunization of mice with purified fusion protein can recognize not only the denatured ICPO protein, but also the native ICPO protein with normal biological conformation.     

Nestedness of waterbird assemblages in the subsidence wetlands recently created by underground coal mining

Nestedness has been a research focus in fields of island biogeography and community ecology in recent decades. Although nestedness of faunal assemblages has been investigated in natural wetlands, it remains largely unknown whether and why waterbird communities in artificial wetlands follow n ested patter ns. We exami ned the existence of n ested ness and un derlyi ng drivers in waterbird comm un ities in subside nee wetlands that are recently created by large-scale un derground coal mining in the North China Plain. Twelve point-count surveys for waterbirds were undertaken approximately every 2 weeks in 55 subside nee wetla nds from September 2016 to April 2017. We used the metric WNODF to estimate nestedness of the assemblages. Partial Spearman rank correlations were performed to examine the association between the nestedness and habitat variables (wetland area, landscape connectivity, wetland age, and habitat diversity) as well as life-history traits (body size, clutch size, dispersal ratio, geographical range size, and migrant status) related to species exti notion risk and colon izati on rate. Waterbird assemblages in the subside nee wetla nds were significantly nested. After controlling for other independent variables, the magnitude of nestedness was significantly and negatively correlated with wetland area and species trait linked to extinction risk (i.e., geographical range size). Our results indicate that selective extinction may be the main driver of the nestedness of waterbird assemblages in our study system. However, the nestedness was not due to passive sampling, selective colonization, or habitat diversity. From a conservation viewpoint, both large wetlands and waterbirds with a small geographic range should be protected to maximize the preserved species richness.     

Geographic variation in parasitism rates of two sympatric cuckoo hosts in China

Rates of brood parasitism vary extensively among host species and populations of a single host species. In this study, we documented and compared parasitism rates of two sympatric hosts, the Oriental Reed Warbler (Acrocephalus orientalis) and the Reed Parrotbill (Paradoxornis heudei), in three populations in China. We found that the Common Cuckoo (Cuculus canorus) is the only parasite using both the Oriental Reed Warbler and Reed Parrotbill as hosts, with a parasitism rate of 22.4%-34.3% and 0%-4.6%, respectively. The multiple parasitism rates were positively correlated with local parasitism rates across three geographic populations of Oriental Reed Warbler, which implies that higher pressure of parasitism lead to higher multiple parasitism rate. Furthermore, only one phenotype of cuckoo eggs was found in the nests of these two host species. Our results lead to two conclusions: (1) The Oriental Reed Warbler should be considered the major host of Common Cuckoo in our study sites; and (2) obligate parasitism on Oriental Reed Warbler by Common Cuckoo is specialized but flexible to some extent, i.e., using Reed Parrotbill as a secondary host. Further studies focusing on egg recognition and rejection behaviour of these two host species should be conducted to test our predictions.