DjFARP Contributes to the Regeneration and Maintenance of the Brain through Activation of DjRac1 in Dugesia japonica.

FERM, RhoGEF, and Pleckstrin domain protein (FARP) mediated RhoGTPase pathways are involved in diverse biological processes, such as neuronal development and tumorigenesis. However, little is known about their role in neural regeneration. We uncovered for the first time that FARP-Rac1 signaling plays an important role in neural regeneration in Dugesia japonica, a planarian that possesses unparalleled regenerative capacities. The planarian FARP homolog DjFARP was primarily expressed in both intact and regenerating brain and pharynx tissue. Functional studies suggested that downregulation of DjFARP with dsRNA in Dugesia japonica led to smaller brain sizes, defects in brain lateral branches, and loss of cholinergic, GABAergic, and dopaminergic neurons in both intact and regenerating animals. Moreover, the Rho GTPase DjRac1 was shown to play a similar role in neural regeneration and maintenance. Rac1 activation assay showed that DjFARP acts as a guanine nucleotide exchange factor (GEF) for DjRac1. Together, these findings indicate that the brain defects seen in DjFARP knockdown animals may be attributable to DjRac1 inactivation. In conclusion, our study demonstrated that DjFARP-DjRac1 signaling was required for the maintenance and proper regeneration of the brain in Dugesia japonica.

Recent trends in T7 phage application in diagnosis and treatment of various diseases.

The T7 phage is a virulent phage hosted by Escherichia coli, which poses no threat to animals and plants. Due to the advantages of small genome, well elucidated functional genomics, fast life cycle, and high stability, T7 phage has been widely used in many fields, including biology and medicine. In this review, we focus on the research of T7 phages in biological sciences and medicine, including the application of T7 phages and T7 phage products, T7 phage display systems, and recombinant T7 phages in the treatment and diagnosis of infectious diseases (bacteria, viruses, parasites) and tumor diseases. In addition, we also introduce the therapeutic application of T7 phage in various diseases such as allergic reaction, Alzheimer's disease, inflammatory reaction, and other diseases, and finally discuss the future direction of T7 phage application in the biomedical field.

An Overview on Functional and Structural Properties of Monomeric and Multimeric ß-Thymosin in Invertebrates.

ß-thymosin 4 (Tß4) is a prototypical actin-monomer sequestering protein that plays an important role in mammalian cells and tissues. In vertebrates, Tß4 is involved in various physiological and pathophysiological processes, such as angiogenesis, hair follicle and hair regeneration, nervous system development, inflammatory response, wound healing, tumour metastasis, and liver and heart protection. Additionally, thymosin domain-containing protein was discovered in invertebrates and was recently shown to be more homologous to Tß4. However, the structural and functional properties are more complex and diverse than those of Tß4. In this review article, we will discuss in detail the structural and functional aspects of ß-thymosin in invertebrates.

Paraflavitalea devenefica sp. nov., isolated from urban soil.

A Gram-stain-negative, rod-shaped, mesophilic, milky white-pigmented, aerobic, non-spore-forming and non-flagellated bacterium, designated strain X16T, was isolated from urban soil of Zibo, Shandong, China. According to 16S rRNA gene sequence analysis, the isolate showed highest similarities with Paraflavitalea soli 5GH32-13T (97.6 %), Pseudoflavitalea soli KIS20-3T (96.2 %), Pseudobacter ginsenosidimutans Gsoil 221T (96.0 %) and Pseudoflavitalea rhizosphaerae T16R-265T (95.8 %). The neighbour-joining tree based on 16S rRNA gene sequences showed that strain X16T formed a subcluster with Paraflavitalea soli 5GH32-13T, and the subcluster was closely related to Pseudoflavitalea soli KIS20-3T, Pseudobacter ginsenosidimutans Gsoil 221T and Pseudoflavitalea rhizosphaerae T16R-265T. Strain X16T also formed a subcluster with Paraflavitalea soli 5GH32-13T in phylogenetic tree based on genomic sequences. The polar lipids are phosphatidylethanolamine, two unknown aminolipids, two unknown aminophospholipids, two unknown lipids and two unknown phospholipids. The major quinone of strain X16T is menaquinone-7 and the main fatty acids (>10 % of total fatty acids) of strain X16T are iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1 G. The genome length of strain X16T is 8.7 Mb with a DNA G+C content of 47.4 %. ANI values among strain X16T and strain Paraflavitalea soli 5GH32-13T, Pseudobacter ginsenosidimutans Gsoil 221T, and Pseudoflavitalea rhizosphaerae T16R-265T are 78.1, 70.7, 70.6 %, respectively. On the basis of the results of the polyphasic characterization presented in this study, it is concluded that strain X16T represents a novel species. Besides, strain X16T can detoxify high toxicity selenite [Se(IV)] to low toxicity elemental selenium [Se(0)], for which the name Paraflavitale devenefica sp. nov. is proposed. The type strain is X16T (=KACC 21698T=GDMCC1.1757T).

Evolution and Structure of API5 and Its Roles in Anti-Apoptosis.

Apoptosis, also named programmed cell death, is a highly conserved physiological mechanism. Apoptosis plays crucial roles in many life processes, such as tissue development, organ formation, homeostasis maintenance, resistance against external aggression, and immune responses. Apoptosis is regulated by many genes, among which Apoptosis Inhibitor-5 (API5) is an effective inhibitor, though the structure of API5 is completely different from the other known Inhibitors of Apoptosis Proteins (IAPs). Due to its high expression in many types of tumors, API5 has received extensive attention, and may be an effective target for cancer treatment. In order to comprehensively and systematically understand the biological roles of API5, we summarized the evolution and structure of API5 and its roles in anti-apoptosis in this review.

The Wnt/Ca2+ signaling pathway is essential for the regeneration of GABAergic neurons in planarian Dugesia japonica.

The growth and differentiation of neurons are critical events in the establishment of proper neuron connectivity and function. Planarians have a remarkable ability to completely regenerate a functional nervous system from a pluripotent stem cell population. Thus, planarians provide a powerful model to identify genes required for neuronal differentiation in vivo. The Wnt/Ca2+ signaling pathway is crucial for cancer development, arousing inflammatory responses, and neurodegeneration. We analyzed the expression patterns and RNAi phenotypes for members of the Wnt/Ca2+ signaling pathway in the planarian, Dugesia japonica. The expression of DjWnt5a, DjPLC-ß, DjCamKII, and DjCaln during regeneration was surprisingly similar and revealing in the regenerated brain. RNAi knockdown of DjWnt5a, DjPLC-ß, DjCamKII, and DjCaln led to defects in regenerated brains including brain partial deletions, incompact phenotypes at the posterior of the new brain, and lateral branches, which could not regenerate. Furthermore, the expressions of GAD and the number of GABAergic neurons decreased. Together, these results suggest that the Wnt/Ca2+ signaling pathway is required for GABAergic neuron regeneration.

Potential targets for intervention against doxorubicin-induced cardiotoxicity based on genetic studies: a systematic review of the literature.

Cardiotoxicity is a well-known adverse effect of doxorubicin (Dox) administration, but the underlying molecular mechanism of this effect is not fully understood. Over the past two decades, considerable efforts have focused on the potential molecular targets of cardiotoxicity in the hope that novel targeted therapies will be generated to attenuate Dox-induced cardiotoxicity. Here, we provide a comprehensive overview of genetically modified animals that show enhanced or reduced susceptibility to the cardiotoxic effects of Dox. We focused on the process by which the molecules involved in DNA damage, oxidative stress, apoptosis, autophagy and necrosis are affected in the presence of Dox. We also present a protein-protein interaction network and explain the contribution of the components to the process of Dox-induced cardiotoxicity. More importantly, data from the literature have indicated that PI3Kγ and Rac1 are potential targets with therapeutic advantages in cancer therapy; molecules that target these proteins can simultaneously attenuate Dox-induced cardiotoxicity and enhance its anticancer activity. This review highlights the potential molecular targets that are critical regulators involved in Dox-mediated cardiotoxicity, thus providing further insight into the development of potential treatment strategies to prevent the cardiotoxic effects and enhance the anticancer efficiency of Dox in cancer patients.

Synthesis and biological activities evaluation of sanjuanolide and its analogues.

Sanjuanolide, psorachalcone A and its seven new analogues were synthesized via a combinatorial strategy by aldol reaction. In order to investigate the effect between electron density in π-conjugated systems and biological activities, several electron-withdrawing and electron-donating groups were introduced at C-4 and the phenolic hydroxyl groups of sanjuanolide. The two natural products and its seven new analogues were investigated for their inhibitory effects against five cancer cell lines. Moreover, the hydroxyisoprenyl group may be important to maintain the biological activities of sanjuanolide.

Identification and characterization of an atypical RIG-I encoded by planarian Dugesia japonica and its essential role in the immune response.

Retinoic acid-inducible gene I (RIG-I), an RNA sensor with a conserved structure, activates the host interferon (IFN) system to produce IFNs and cytokines for eliminating pathogens upon recognizing PAMPs. However, the biological functions and the mechanism by which RIG-I regulates the innate immunity response in invertebrates are still unknown at present. Here we identified an atypical RIG-I in planarian Dugesia japonica. Sequence analysis, 3D structure modeling and phylogenetic analysis showed that this atypical protein was clustered into a single clade at the base of the tree in invertebrates, suggesting that DjRIG-I is an ancient and unique protein of the RIG-I-like receptors (RLRs). In situ hybridization analysis revealed that the DjRIG-I mRNAs were predominantly expressed in the pharynx and head of the adult and regenerative planarians. Stimulation with PAMPs induced the over-expression of DjRIG-I in planarians. The molecular simulation demonstrated that DjRIG-I formed a large hole-structure for the docking of dsRNAs, and the pull-down assay confirmed the interaction between DjRIG-I and viral analog poly(I:C). Importantly, some representative antiviral/antibacterial genes in the RIG-I-mediated IFN and P38 signaling pathway, TBK1, IRF-3, Mx, and P38, were significantly upregulated in planarians stimulated with PAMPs. Interference of the DjRIG-I expression by RNAi, inhibited the PAMPs-induced over-expression, suggesting that DjRIG-I is a key player for downstream signaling events. These results indicate that DjRIG-I triggered the intracellular signaling cascades independent of the classical CARD domains and played an essential role in the virus/bacteria-induced innate immunity of planarian.

A novel agent attenuates cardiotoxicity and improves antitumor activity of doxorubicin in breast cancer cells.

Doxorubicin (Dox) is a well-known chemotherapeutic agent used in the treatment of various cancers. However, Dox-induced cardiotoxicity limits its further clinical use. We have previously reported a small molecular named biotin-conjugated ADTM analog (BAA) that exhibits cytoprotective effects against oxidative stress-induced cell injury in cardiomyoblast H9c2 cells. Here, the protective effects of BAA, indexed by attenuation of the cardiotoxicity induced by Dox as well as synergistic antitumor activity that increases the chemotherapeutic efficacy of Dox were investigated. Our results demonstrated that BAA significantly ameliorated Dox-induced toxicity in the H9c2 cells and zebrafish models. In addition, BAA attenuated Dox-induced endoplasmic reticulum (ER) stress in H9c2 cells. An ER stress inhibitor, 4-phenylbutyric acid, reversed the protective effect of BAA in H9c2 cells. In contrast, in human breast tumor MDA-MB-231 cells, BAA significantly enhanced Dox-induced cytotoxicity through upregulating Dox-induced ER stress response. Taken together, our findings indicate that Dox combined with BAA can significantly enhance its antitumor activity in breast cancer cells and reduce its cardiotoxicity, at least in part, by mediating ER stress activation.

Identification and characterization of a TNF receptor-associated factor in Dugesia japonica.

The tumor necrosis factor (TNF) superfamily consists of a wide variety of inflammatory cytokine, including cell-bound and secreted proteins. These TNFs function through binding and activation of the TNF receptors for modulating TNF-associated intracellular signals. A set of mammalian TNF receptor-associated factors (TRAFs) that have emerged as the major signal transducers for the TNF receptor superfamily, play an important role in both adaptive and innate immunity. However, the existence of TRAFs and their biological functions in planarian are still unknown. In this study, a new member of TRAFs, DjTRAF2, was identified in planarian Dugesia japonica. Phylogenetic analysis revealed that DjTRAF2 could be a new member of the invertebrate TRAF2 family. Sequence analysis showed that the open reading frame of DjTRAF2 had 1353 bp in length and encoded a putative protein of 450 amino acids with a predicted molecular mass of ~51.8 kDa and an isoelectric point of 7.052. Whole-mount in situ hybridization showed that DjTRAF2 was predominantly expressed in adult and regenerative pharynx, which is an important immune organ of planarian. Quantitative real-time PCR revealed that the transcriptional level of DjTRAF2 was significantly up-regulated after induced by pathogen-associated molecular patterns (polyinosinic-polycytidylic acid, lipopolysaccharide, peptidoglycan and ß-glucan), suggesting that DjTRAF2 is involved in the immune response against pathogen invasion. Collectively, these results demonstrated that DjTRAF2 might play important roles in the innate immunity of planarian.

Mitochondria-Targeting Small Molecules Effectively Prevent Cardiotoxicity Induced by Doxorubicin.

Doxorubicin (Dox) is a chemotherapeutic agent widely used for the treatment of numerous cancers. However, the clinical use of Dox is limited by its unwanted cardiotoxicity. Mitochondrial dysfunction has been associated with Dox-induced cardiotoxicity. To mitigate Dox-related cardiotoxicity, considerable successful examples of a variety of small molecules that target mitochondria to modulate Dox-induced cardiotoxicity have appeared in recent years. Here, we review the related literatures and discuss the evidence showing that mitochondria-targeting small molecules are promising cardioprotective agents against Dox-induced cardiac events.

14-3-3 α and 14-3-3 ζ contribute to immune responses in planarian Dugesia japonica.

14-3-3 proteins are a family of highly conserved acidic proteins that regulate cellular processes. They act as a kind of important signaling molecules taking part in many crucial decisions throughout the development process. We have isolated and characterized two members of the 14-3-3 family, namely, Dj14-3-3 α and Dj14-3-3 ζ in the planarian Dugesia japonica. The Dj14-3-3 α and ζ genes encode polypeptides of 260 and 255 amino acids respectively. We have proved that the Dj14-3-3 α and ζ genes were especially expressed in the pharynx in adult and regenerating planarians by in situ hybridization and they were not involved in regeneration process. Besides, Dj14-3-3 α and ζ genes can compensate each other in planarians by RNA interference. The Dj14-3-3 α and ζ were significantly up-regulated expression when planarians were stimulated with the pathogen-associated molecular patterns including lipopolysaccharide (LPS), peptidoglycan (PGN), ß-Glu and Poly (I:C), indicating that the Dj14-3-3 α and ζ may be involved in the immune responses.

First identification and functional analysis of a histidine triad nucleotide binding protein in an invertebrate species Haliotis diversicolor supertexta.

Histidine triad nucleotide binding protein (HINT) represents the most ancient and widespread branches in the histidine triad superfamily. HINT plays an important role in many biological processes especially in cell biology, and it has been found in a wide variety of species. However, the functional attributes of HINT homologues in invertebrates have not yet been reported. Here we identified a HINT homologue in abalone, which we named ab-HINT. The ab-HINT shows significant structural and functional similarities to mammalian HINT. RT-PCR and western blot analysis show that ab-HINT is ubiquitously expressed in abalone tissues and highly expressed in hemocyte and gills. In addition, significant up-regulation of ab-HINT was observed after LPS or Poly I:C challenge. Immunostainings suggest that ab-HINT is expressed predominantly in epithelial cells and mainly localized in the cytoplasmic compartment. Studies of the effect on cell apoptosis indicate that ab-HINT can trigger hemocytes apoptosis and p53 is involved in this process. These results conclude that ab-HINT is involved in the immune response of abalone and may be a potential pro-apoptotic factor. To the best of our knowledge, this is the first identification and characterization of a HINT homologue in invertebrates.