Neuropeptide Y regulates the hematopoietic stem cell microenvironment and prevents nerve injury in the bone marrow

Many reports have revealed the importance of the sympathetic nervous system (SNS) in the control of the bone marrow environment. However, the specific role of neuropeptide Y (NPY) in this process has not been systematically studied. Here we show that NPY‐deficient mice have significantly reduced hematopoietic stem cell (HSC) numbers and impaired regeneration in bone marrow due to apoptotic destruction of SNS fibers and/or endothelial cells. Furthermore, pharmacological elevation of NPY prevented bone marrow impairments in a mouse model of chemotherapy‐induced SNS injury, while NPY injection into conditional knockout mice lacking the Y1 receptor in macrophages did not relieve bone marrow dysfunction. These results indicate that NPY promotes neuroprotection and restores bone marrow dysfunction from chemotherapy‐induced SNS injury through the Y1 receptor in macrophages. They also reveal a new role of NPY as a regulator of the bone marrow microenvironment and highlight the potential therapeutic value of this neuropeptide.     

Immunomodulatory effects of umbilical cord‐derived mesenchymal stem cells

Umbilical cord blood (UCB) is of great interest as a source of stem cells for use in cellular therapies. The immunomodulatory effect of mesenchymal stem cells (MSCs) originating from bone marrow, adipose tissue and amniotic membrane has previously been reported. In this study, MSCs were isolated from UCB with the aim of evaluating their immunomodulatory effects on proliferation of PB lymphocytes by two different techniques; namely, 5‐bromo‐2‐deoxyuridine ELISA and a carboxy fluorescein diacetate succinimidyl ester flow cytometric technique. MSCs were isolated from UCB, propagated until Passage four, and then characterized for cell surface markers by flow cytometry and ability to differentiate towards osteocytes and adipocytes. Immunosuppressive effects on PB lymphocytes were examined by co‐culturing mitomycin C‐treated UCB MSCs with mitogen‐stimulated lymphocytes for 72 hr. Thereafter, proliferation of lymphocytes was detected by CFSE flow cytometry and colorimetric ELISA. The titers of cytokines in cell culture supernatant were also assayed to clarify possible mechanisms of immunomodulation. UCB MSCs suppressed mitogen‐stimulated lymphocyte proliferation, which occurs via both cell‐cell contact and cytokine secretion. Titers of transforming growth factor beta and IL 10 increased, whereas that of IFN‐γ decreased in the supernatants of co‐cultures. Thus, UCB MSCs suppress the proliferation of mitogen‐stimulated lymphocytes. However further in vivo studies are required to fully evaluate the immunomodulatory effects of UCB MSCs.     

Aging in the colonial chordate,Botryllus schlosseri

What mechanisms underlie aging? One theory, the wear-and-tear model, attributes aging to progressive deterioration in the molecular and cellular machinery which eventually lead to death through the disruption of physiological homeostasis. The second suggests that life span is genetically programmed, and aging may be derived from intrinsic processes which enforce a non-random, terminal time interval for the survivability of the organism. We are studying an organism that demonstrates both properties: the colonial ascidian, Botryllus schlosseri. Botryllus is a member of the Tunicata, the sister group to the vertebrates, and has a number of life history traits which make it an excellent model for studies on aging. First, Botryllus has a colonial life history, and grows by a process of asexual reproduction during which entire bodies, including all somatic and germline lineages, regenerate every week, resulting in a colony of genetically identical individuals. Second, previous studies of lifespan in genetically distinct Botryllus lineages suggest that a direct, heritable basis underlying mortality exists that is unlinked to reproductive effort and other life history traits. Here we will review recent efforts to take advantage of the unique life history traits of B. schlosseri and develop it into a robust model for aging research.     

Malignant mesothelioma as an oxidative stress-induced cancer: An update

Malignant mesothelioma (MM) is a relatively rare cancer that occurs almost exclusively following respiratory exposure to asbestos in humans. Its pathogenesis is closely associated with iron overload and oxidative stress in mesothelial cells. On fiber exposure, mesothelial cells accumulate fibers simultaneously with iron, which either performs physical scissor function or catalyzes free radical generation, leading to oxidative DNA damage such as strand breaks and base modifications, followed by activation of intracellular signaling pathways. Chrysotile, per se without iron, causes massive hemolysis and further adsorbs hemoglobin. Exposure to indigestible foreign materials also induces chronic inflammation, involving consistent generation of free radicals and subsequent activation of NALP3 inflammasomes in macrophages. All of these contribute to mesothelial carcinogenesis. Genomic alterations most frequently involve homozygous deletion of INK4A/4B, and other pathways such as Hippo and TGF-β pathways are also affected in MM. Recently, analyses of familial MM sorted out BAP1 as a novel responsible tumor suppressor gene, whose function is not fully elucidated. Five-year survival of mesothelioma is still ~8%, and this cancer is increasing worldwide. Connective tissue growth factor, a secretory protein creating a vicious cycle mediated by β-catenin, has been recognized as a hopeful target for therapy, especially in sarcomatoid subtype. Recent research outcomes related to microRNAs and cancer stem cells also offer additional novel targets for the treatment of MM. Iron reduction as chemoprevention of mesothelioma is helpful at least in an animal preclinical study. Integrated approaches to fiber-induced oxidative stress would be necessary to overcome this currently fatal disease.     

Immunobiology and signaling pathways of cancer stem cells: implication for cancer therapy

Cancer stem cells (CSCs) need to survive cancer treatments with a specific end goal to provide new, more differentiated, metastatic-prone cancerous cells. This happens through diverse signals delivered within the tumor microenvironment where ample evidence indicates that altered developmental signaling pathways play an essential role in maintaining CSCs and accordingly the survival and the progression of the tumor itself. This review summarizes findings on the immunobiological properties of CSCs as compared with cancerous non-stem cells involving the expression of immunological molecules, cytokines and tumor antigens as well as the roles of the Notch, Wnt and Hedgehog pathways in the brain, breast and colon CSCs. We concluded that if CSCs are the main driving force behind tumor support and growth then understanding the molecular mechanisms and the immunological properties directing these cells for immune tolerance is of great clinical significance. Such knowledge will contribute to designing better targeted therapies that could prevent tumor recurrence and accordingly significantly improve cancer treatments and patient survival.     

Genetic Diversity and Pathogenicity of Fusarium oxysporum f.sp. melonis Races from Different Areas of Italy

Fusarium wilt caused by Fusarium oxysporum f.sp. melonis (FOM) is a devastating disease of melon worldwide. Pathogenicity tests performed with F. oxysporum isolates obtained from Italian melon‐growing areas allowed to identify thirty‐four FOM isolates and the presence of all four races. The aims of this work were to examine genetic relatedness among FOM isolates by race determination and to perform phylogenetic analyses of identified FOM races including also other formae speciales of F. oxysporum of cucurbits. Results showed that FOM race 1,2 was the most numerous with a total of eighteen isolates, while six and nine isolates were identified as race 0 and 1, respectively, and just one isolate was assigned to race 2. Phylogenetic analysis was performed by random amplified polymorphic DNA (RAPD) profiling and by translation elongation factor‐1α (TEF‐1α) sequencing. The analysis of RAPD profiles separated FOM races into two distinct clades. Clade 1, which included races 0, 1 and 1,2, was further divided into ‘subclade a’ which grouped almost all race 1,2 isolates, and into ‘subclade b’ which included race 0 and 1 isolates. Clade 2 comprised only race 2 isolates. The phylogenetic analysis based on TEF‐1α separated FOM from the other formae speciales of F. oxysporum. Also with TEF‐1α analysis, FOM races 0, 1 and 1,2 isolates grouped in one single clade clearly separated from FOM race 2 isolates which grouped closer to F. oxysporum f.sp. cucumerinum. RAPD technique was more effective than TEF‐1α in differentiating FOM race 1,2 isolates from those belonging to the closely related races 0 and 1. Both phylogenetic analyses supported the close relationship between the three different FOM races which might imply the derivation from one another and the different origin of FOM race 2.     

Combination of inflammation-related cytokines promotes long-term muscle stem cell expansion

Muscle stem cells (MuSCs, satellite cells) are the major contributor to muscle regeneration. Like most adult stem cells, long-term expansion of MuSCs in vitro is difficult. The in vivo muscle regeneration abilities of MuSCs are quickly lost after culturing in vitro, which prevents the potential applications of MuSCs in cell-based therapies. Here, we establish a system to serially expand MuSCs in vitro for over 20 passages by mimicking the endogenous microenvironment. We identified that the combination of four pro-inflammatory cytokines, IL-1α, IL-13, TNF-α, and IFN-γ, secreted by T cells was able to stimulate MuSC proliferation in vivo upon injury and promote serial expansion of MuSCs in vitro. The expanded MuSCs can replenish the endogenous stem cell pool and are capable of repairing multiple rounds of muscle injuries in vivo after a single transplantation. The establishment of the in vitro system provides us a powerful method to expand functional MuSCs to repair muscle injuries.     

积水和网孔大小对青藏高原高寒沼泽化草甸优势种黑褐苔草叶片凋落物早期分解的影响

2013年5月,在青藏高原高寒沼泽化草甸收集优势种黑褐苔草(Carex atrofusca)立枯体凋落物。6月初,选择3个样带:长期积水带、周期性积水带和无积水带,并结合凋落物分解袋的方法,在每个样带区设置网孔大小分别为大(4.5 mm)、中(2.0 mm)、小(0.1mm)的3种凋落物分解袋,研究积水状态和网孔大小对凋落物早期分解的影响。结果显示:长期积水显著抑制凋落物的分解,而周期性积水和无积水环境中凋落物的质量损失率在大、中、小网孔凋落物袋中没有显著性的差异;网孔显著影响凋落物质量损失率,表现为大网孔中网孔小网孔;在早期分解过程中,凋落物的氮、磷均表现为富集;积水状态显著影响凋落物分解后氮、磷的富集;网孔大小对凋落物氮富集的影响显著,而对磷富集的影响不显著;积水状态和网孔大小对凋落物氮富集影响的交互作用极显著,但对磷富集没有显著的交互作用。研究发现,积水状态和网孔大小影响高寒沼泽化草甸凋落物分解以及氮、磷养分动态,由于不同网孔对凋落物分解的影响可用来反映不同土壤生物对凋落物分解的影响,因此,积水和土壤生物对维持高寒沼泽化草甸生态系统的结构和功能起着非常重要的作用。     

Multiplex ligation-dependent probe amplification for identification of correctly targeted murine embryonic stem cell clones

Following locus-specific genome editing of mouse embryonic stem cells (ESCs), the identification of correctly targeted clones remains a challenge. We applied multiplex ligation-dependent probe amplification (MLPA) to screen for homologous recombination-based genomic integration of a knockout construct in which part of a gene is deleted. All candidate ESCs thereby identified were subsequently validated by conventional methods. Thus, MLPA represents a highly reliable as well as cost- and time-efficient alternative to currently applied methods such as Southern blotting and polymerase chain reaction (PCR)-based approaches. It is also applicable to knockin recombination strategies and compatible with the CRISPR/Cas9 system and other genome editing strategies.