Novel Binding Partners and Differentially Regulated Phosphorylation Sites Clarify Eps8 as a Multi-Functional Adaptor

Eps8 is involved in both cell signalling and receptor trafficking. It is a known phosphorylation substrate for two proteins involved in the fibroblast growth factor receptor (FGFR) signalling pathway: the receptor itself and Src. Here we report a differential proteomic analysis of Eps8 aimed to identify specific FGFR and Src family kinase dependent phosphosites and co-associated phosphodependent binding partners. This study reveals a total of 22 Eps8 pTyr and pSer/Thr phosphorylation sites, including those that are dependent on Src family and FGFR kinase activity. Peptide affinity purification of proteins that bind to a selection of the pTyr phosphosites has identified a range of novel Eps8 binding partners including members of the intracellular vesicle trafficking machinery (clathrin and AP-2), proteins which have been shown to regulate activated receptor trafficking (NBR1 and Vav2), and proteins involved in receptor signalling (IRS4 and Shp2). Collectively this study significantly extends the understanding of Eps8 post-translational modification by regulated phosphorylation, identifies novel Eps8 binding partners implicated in receptor trafficking and signalling, and confirms the functions of Eps8 at the nexus of receptor signalling and vesicular trafficking.     

Fat body and hemocyte contribution to the antimicrobial peptide synthesis in <Emphasis Type="Italic">Calliphora vicina</Emphasis> R.-D. (Diptera: Calliphoridae) larvae

Antimicrobial peptides accumulated in the hemolymph in response to infection are a key element of insect innate immunity. The involvement of the fat body and hemocytes in the antimicrobial peptide synthesis is widely acknowledged, although release of the peptides present in the hemolymph from the immune cells was not directly verified so far. Here, we studied the presence of antimicrobial peptides in the culture medium of fat body cells and hemocytes isolated from the blue blowfly Calliphora vicina using complex of liquid chromatography, mass spectrometry, and antimicrobial activity assays. Both fat body and hemocytes are shown to synthesize and release to culture medium defensin, cecropin, diptericins, and proline-rich peptides. The spectra of peptide antibiotics released by the fat body and hemocytes partially overlap. Thus, the results suggest that insect fat body and blood cells are capable of releasing mature antimicrobial peptides to the hemolymph. It is notable that the data obtained demonstrate dramatic difference in the functioning of insect antimicrobial peptides and their mammalian counterparts localized into blood cells’ phagosomes where they exert their antibacterial activity.     

Haemoglobinopathy survey in an Eti-Turk village.

Blood specimens were obtained from 281 inhabitants of an Eti-Turk village with a population of about 500. Starch gel (pH 8.6) and agar gel (pH 6.45) electrophoresis were performed in 279 of the specimens. Hb S was present in 105 partially interrelated persons (37.36%), three of whom had sickle-cell anaemia. Hb E was detected in 5 persons (1.79%), one of whom was a double heterozygote for Hb S and Hb E. One Hb S+alpha-thalassaemia and 7 Hb S with elevated Hb A'2 combinations were found. The beta-thalassaemia gene prevalence was 0.0377. Hb A2 was found in 4 persons (1.42%), and Hb F was slightly increased in 37 (22.3%) persons with a normal haemoglobin picture. Erythrocyte G-6-PD deficiency was 10% among males.     

Analysis of Thisbe and Pyramus functional domains reveals evidence for cleavage of <Emphasis Type="Italic">Drosophila</Emphasis> FGFs

Background  

As important regulators of developmental and adult processes in metazoans, Fibroblast Growth Factor (FGF) proteins are potent signaling molecules whose activities must be tightly regulated. FGFs are known to play diverse roles in many processes, including mesoderm induction, branching morphogenesis, organ formation, wound healing and malignant transformation; yet much more remains to be learned about the mechanisms of regulation used to control FGF activity.     

Survey of Scalp Dermatophyte Carriage in a Day Care Center in Turkey

The prevalence of tinea capitis and the symptom-free colonisation of the scalp with dermatophytes were examined in 502 mentally retarded participants who attended day care centers in the Tarsus district, Mersin, Turkey. Between December 2006 and May 2007, a screening study was conducted in three centers on a total of 316 (62.9%) male and 186 (37.1%) female participants aged 12 ± 6.2 years. The examinations were carried out in parallel with the hairbrush, toothbrush, and cotton swab methods by inoculation onto Sabouraud glucose agar. No participant was diagnosed with tinea capitis; however, we detected three carriers, all of whom were boys aged 2–16 years. The total prevalence of carrier state was 0.6%. Of three boys, T. tonsurans was seen in two cases (66.7%), and in one case a zoophilic variant of T. mentagrophytes (33.3%) was isolated. The diagnosis was made via the hairbrush method in all three carriers. We also did a screening study on ten households of the three asymptomatic carriers. T. mentagrophytes also was isolated in a 5-year-old sister of the boy with T. mentagrophytes colonisation. All the carriers were followed-up without any antimycotic treatment. In two of the participants, the carrier state persisted at the 13th and 17th week follow-ups, and mycological clearance was documented at the 20th and 24th week for these individuals. The third case and the household’s culture were found negative at the 7- and 12-week follow-ups. Despite poor hygienic conditions and the participants’ difficulties in performing basic hygiene practices, asymptomatic carriage was found to be surprisingly less prevalent among the mentally retarded individuals.     

Germacrone improves liver fibrosis by regulating the PI3K/AKT/mTOR signalling pathway

Liver fibrosis is a primary threat to public health, owing to limited therapeutic options. Germacrone (GM) has been shown to exert various curative effects against human diseases, including liver injury. The aim of this study was to investigate the pharmacological effects of GM in the pathophysiology of hepatic fibrosis and determine its potential mechanisms of action. A liver fibrosis rat model was established via carbon tetrachloride (CCl₄) treatment, and LX-2 cells were stimulated with TGF-β1. The effects of GM on liver fibrosis and its relationship with the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signalling pathway were investigated. In the CCl₄ fibrosis-induced rat model, GM improved histological damage, inhibited the activity of hepatic α-smooth muscle actin and improved serum alanine aminotransferase and aspartate aminotransferase levels in a dose-dependent manner. GM potently inhibited hepatic stellate cells (HSCs) growth and epithelial–mesenchymal transition (EMT) progression, as reflected by the altered expression of proliferative (Ki-67, PCNA and cleaved caspase-3) and EMT-related (E-cadherin and vimentin) proteins. In TGF-β1-stimulated LX-2 cells, GM significantly inhibited the survival and activation of HSCs and induced cell apoptosis. GM also suppressed the migration ability and reversed the EMT process in HSCs. Following GM treatment, the phosphorylation of the PI3K, AKT and mTOR proteins was reduced in the liver of CCl₄-treated rats and TGF-β1-stimulated LX-2 cells, indicating that GM may attenuate hepatic fibrosis via the PI3K/AKT/mTOR signalling pathway. These outcomes highlight the anti-fibrotic effects of GM and suggest that it is a potential therapeutic agent for the treatment of liver fibrosis.