Reservoir competence of various rodents for the lyme disease Spirochete Borrelia spielmanii

To determine whether the pathogenic Lyme disease spirochete Borrelia spielmanii is adapted exclusively to garden dormice, we compared the reservoir competence of various rodent species for this spirochete, including sympatric and peridomestic rodents. The different kinds of rodents varied in their attractiveness to nymphal ticks and their level of susceptibility to tick-borne B. spielmanii infection, but only the edible dormouse appeared to be refractory. Although hazel dormice and Norway rats became infectious to ticks somewhat later than did garden dormice, they remained infectious for a longer period of time. During the course of a tick season, garden and hazel dormice contributed theoretically more than twice as many B. spielmanii-infected ticks than the somewhat less susceptible Norway rats and wood or yellow-necked mice. Hazel dormice appeared to be extraordinarily competent as reservoir hosts for B. spielmanii. Because peridomestic rodents proved to be reservoir competent, urban foci of transmission of B. spielmanii may affect the health of townspeople.     

An integrin-binding N-terminal peptide region of TIMP-2 retains potent angio-inhibitory and anti-tumorigenic activity in vivo

Tissue inhibitor of metalloproteinases-2 (TIMP-2) inhibits angiogenesis by several mechanisms involving either MMP inhibition or direct endothelial cell binding. The primary aim of this study was to identify the TIMP-2 region involved in binding to the previously identified receptor integrin α3β1, and to determine whether synthetic peptides derived from this region retained angio-inhibitory and tumor suppressor activity. We demonstrated that the N-terminal domain of TIMP-2 (N-TIMP-2) binds to α3β1 and inhibits vascular endothelial growth factor-stimulated endothelial cell growth in vitro, suggesting that both the α3β1-binding domain and the growth suppressor activity of TIMP-2 localize to the N-terminal domain. Using a peptide array approach we identify a 24 amino acid region of TIMP-2 primary sequence, consisting of residues Ile43-Ala66, which shows α3β1-binding activity. Subsequently we demonstrate that synthetic peptides from this region compete for TIMP-2 binding to α3β1 and suppress endothelial growth in vitro. We define a minimal peptide sequence (peptide 8-9) that possesses both angio-inhibitory and, using a murine xenograft model of Kaposi's sarcoma, anti-tumorigenic activity in vivo. Thus, both the α3β1-binding and the angio-inhibitory activities co-localize to a solvent exposed, flexible region in the TIMP-2 primary sequence that is unique in amino acid sequence compared with other members of the TIMP family. Furthermore, comparison of the TIMP-2 and TIMP-1 protein 3-D structures in this region also identified unique structural differences. Our findings demonstrate that the integrin binding, tumor growth suppressor and in vivo angio-inhibitory activities of TIMP-2 are intimately associated within a unique sequence/structural loop (B-C loop).     

Composition and structure elucidation of human milk glycosaminoglycans

To date, there is no complete structural characterization of human milk glycosaminoglycans (GAGs) available nor do any data exist on their composition in bovine milk. Total GAGs were determined on extracts from human and bovine milk. Samples were subjected to digestion with specific enzymes, treated with nitrous acid, and analyzed by agarose-gel electrophoresis and high-performance liquid chromatography for their structural characterization. Quantitative analyses yielded ～7 times more GAGs in human milk than in bovine milk. In particular, galactosaminoglycans, chondroitin sulfate (CS) and dermatan sulfate (DS), were found to differ considerably from one type of milk to the other. In fact, hardly any DS was observed in human milk, but a low-sulfated CS having a very low charge density of 0.36 was found. On the contrary, bovine milk galactosaminoglycans were demonstrated to be composed of ～66% DS and 34% CS for a total charge density of 0.94. Structural analysis performed by heparinases showed a prevalence of fast-moving heparin over heparan sulfate, accounting for ～30-40% of total GAGs in both milk samples and showing lower sulfation in human (2.03) compared with bovine (2.28). Hyaluronic acid was found in minor amounts. This study offers the first full characterization of the GAGs in human milk, providing useful data to gain a better understanding of their physiological role, as well as of their fundamental contribution to the health of the newborn.     

Epigenetic Reprogramming of Human Embryonic Stem Cells into Skeletal Muscle Cells and Generation of Contractile Myospheres

1. Download : Download full-size image

Highlights? hESCs are resistant to MyoD-mediated myogenic conversion ? BAF60C is the limiting factor for activation of skeletal myogenesis in hESCs ? BAF60C instructs MyoD for activation of target genes in hESCs ? Epigenetically committed hESCs are suitable for generation of contractile myospheres     

Survival in HIV-Infected Patients after a Cancer Diagnosis in the cART Era: Results of an Italian Multicenter Study

Objectives

We studied survival and associated risk factors in an Italian nationwide cohort of HIV-infected individuals after an AIDS-defining cancer (ADC) or non-AIDS-defining cancer (NADC) diagnosis in the modern cART era.

Methods

Multi-center, retrospective, observational study of HIV patients included in the MASTER Italian Cohort with a cancer diagnosis from January 1998 to September 2012. Malignancies were divided into ADC or NADC on the basis of the Centre for Disease Control-1993 classification. Recurrence of cancer and metastases were excluded. Survivals were estimated according to the Kaplan-Meier method and compared according to the log-rank test. Statistically significant variables at univariate analysis were entered in a multivariate Cox regression model.

Results

Eight hundred and sixty-six cancer diagnoses were recorded among 13,388 subjects in the MASTER Database after 1998: 435 (51%) were ADCs and 431 (49%) were NADCs. Survival was more favorable after an ADC diagnosis than a NADC diagnosis (10-year survival: 62.7%±2.9% vs. 46%±4.2%; p = 0.017). Non-Hodgkin lymphoma had lower survival rates than patients with Kaposi sarcoma or cervical cancer (10-year survival: 48.2%±4.3% vs. 72.8%±4.0% vs. 78.5%±9.9%; p<0.001). Regarding NADCs, breast cancer showed better survival (10-year survival: 65.1%±14%) than lung cancer (1-year survival: 28%±8.7%), liver cancer (5-year survival: 31.9%±6.4%) or Hodgkin lymphoma (10-year survival: 24.8%±11.2%). Lower CD4+ count and intravenous drug use were significantly associated with decreased survival after ADCs or NADCs diagnosis. Exposure to cART was found to be associated with prolonged survival only in the case of ADCs.

Conclusions

cART has improved survival in patients with an ADC diagnosis, whereas the prognosis after a diagnosis of NADCs is poor. Low CD4+ counts and intravenous drug use are risk factors for survival following a diagnosis of ADCs and Hodgkin lymphoma in the NADC group.     

Innovative functional cAMP assay for studying G protein-coupled receptors: application to the pharmacological characterization of GPR17

In this work, an innovative and non-radioactive functional cAMP assay was validated at the GPR17 receptor. This assay provides a simple and powerful new system to monitor G protein-coupled receptor activity through change in the intracellular cAMP concentration by using a mutant form of Photinus pyralis luciferase into which a cAMP-binding protein moiety has been inserted. Results, expressed as EC₅₀ or IC₅₀ values for agonists and antagonists, respectively, showed a strong correlation with those obtained with [³⁵S]GTPγS binding assay, thus confirming the validity of this approach in the study of new ligands for GPR17. Moreover, this method allowed confirming that GPR17 is coupled with a G_αi.     

Metabolic reprogramming in cancer: unraveling the role of glutamine in tumorigenesis

Increased glutaminolysis is now recognized as a key feature of the metabolic profile of cancer cells, along with increased aerobic glycolysis (the Warburg effect). In this review, we discuss the roles of glutamine in contributing to the core metabolism of proliferating cells by supporting energy production and biosynthesis. We address how oncogenes and tumor suppressors regulate glutamine metabolism and how cells coordinate glucose and glutamine as nutrient sources. Finally, we highlight the novel therapeutic and imaging applications that are emerging as a result of our improved understanding of the role of glutamine metabolism in cancer.     

Asexual blood stages of Plasmodium falciparum exhibit signs of secondary necrosis, but not classical apoptosis after exposure to febrile temperature (40 C)

It has been shown by others that after cultures of Plasmodium falciparum were exposed to a febrile temperature of 40 C, parasitemia was reduced in the subsequent generation, suggesting a temperature-induced inhibition of trophozoites and schizonts. In the current study, influences unique to cultivation were ruled out, demonstrating that 40 C impacted the parasites directly. Metabolic profiling of DNA synthesis, protein synthesis, and glucose utilization clearly indicated that febrile temperatures had a direct effect on parasite development, beginning 20-24 hr after erythrocyte invasion. The mechanism of parasite death was investigated for evidence of temperature-induced apoptosis. Lack of typical physiological hallmarks, namely, caspase activation, characteristic mitochondrial membrane potential changes, and DNA degradation as indicated by DNA laddering, eliminated 'classical' apoptosis as a mechanism of parasite death. Parasites dying under the influence of heat, staurosporine, and chloroquine initially appeared pyknotic by light and electron microscopy (as in apoptosis), but eventual swelling and lysis of the food vacuole membrane led to secondary necrosis. Chloroquine did induce DNA laddering, but it was later attributed to occult white blood cell contaminants. While not apoptosis, the results do not rule out other forms of temperature-induced programmed cell death.