Development of recombinant <Emphasis Type="Italic">Yarrowia lipolytica</Emphasis> producing virus-like particles of a fish nervous necrosis virus

Nervous necrosis virus (NNV) causes viral encephalopathy and retinopathy, a devastating disease of many species of cultured marine fish worldwide. In this study, we used the dimorphic non-pathogenic yeast Yarrowia lipolytica as a host to express the capsid protein of red-spotted grouper nervous necrosis virus (RGNNV-CP) and evaluated its potential as a platform for vaccine production. An initial attempt was made to express the codon-optimized synthetic genes encoding intact and N-terminal truncated forms of RGNNV-CP under the strong constitutive TEF1 promoter using autonomously replicating sequence (ARS)-based vectors. The full-length recombinant capsid proteins expressed in Y. lipolytica were detected not only as monomers and but also as trimers, which is a basic unit for formation of NNV virus-like particles (VLPs). Oral immunization of mice with whole recombinant Y. lipolytica harboring the ARS-based plasmids was shown to efficiently induce the formation of IgG against RGNNV-CP. To increase the number of integrated copies of the RGNNV-CP expression cassette, a set of 26S ribosomal DNA-based multiple integrative vectors was constructed in combination with a series of defective Ylura3 with truncated promoters as selection markers, resulting in integrants harboring up to eight copies of the RGNNV-CP cassette. Sucrose gradient centrifugation and transmission electron microscopy of this high-copy integrant were carried out to confirm the expression of RGNNV-CPs as VLPs. This is the first report on efficient expression of viral capsid proteins as VLPs in Y. lipolytica, demonstrating high potential for the Y. lipolytica expression system as a platform for recombinant vaccine production based on VLPs.     

Administration of vitamin E attenuates airway inflammation through restoration of Nrf2 in a mouse model of asthma

Accumulating evidence reveals that ROS is one of the key mediators that contribute to the development of asthma. Studies on antioxidants have shown to have beneficial effects on asthma management. However, we still do not know the precise mechanism, and the effects depend on age. This study was conducted to assess the levels of ROS and the effect of antioxidants in younger and older mice using an eosinophilic asthma model. We analyzed airway hyperresponsiveness (AHR), cytokines in bronchoalveolar lavage fluid (BALF), inflammatory cell counts, and the expression levels of NFκB, Nrf2, EPx, and EDN in the lung tissue, as well as the level of ROS in the lung tissue and BALF. The degree of eosinophilia and the levels of IL-5, ROS, and NFκB were significantly increased, whereas the endogenous levels of vitamin E and Nrf2 were decreased in the lung and BALF in the older mice compared to younger mice. The administration of vitamin E attenuated AHR, airway inflammation, and the level of IL-13 and ROS and enhanced the Nrf2 level in the older mice compared to the younger mice. Taken together, vitamin E treatment may have the therapeutic potential through restoration of the Nrf2 level, especially in elderly asthma.     

Photodynamic therapy and tumor imaging of hypericin-treated squamous cell carcinoma

Background

The use of cellular and cordless telephones has increased dramatically during the last decade. There is concern of health problems such as malignant diseases due to microwave exposure during the use of these devices. The brain is the main target organ.

Methods

Since the second part of the 1990's we have performed six case-control studies on this topic encompassing use of both cellular and cordless phones as well as other exposures. Three of the studies concerned brain tumours, one salivary gland tumours, one non-Hodgkin lymphoma (NHL) and one testicular cancer. Exposure was assessed by self-administered questionnaires.

Results

Regarding acoustic neuroma analogue cellular phones yielded odds ratio (OR) = 2.9, 95 % confidence interval (CI) = 2.0–4.3, digital cellular phones OR = 1.5, 95 % CI = 1.1–2.1 and cordless phones OR = 1.5, 95 % CI = 1.04–2.0. The corresponding results were for astrocytoma grade III-IV OR = 1.7, 95 % CI = 1.3–2.3; OR = 1.5, 95 % CI = 1.2–1.9 and OR = 1.5, 95 % CI = 1.1–1.9, respectively. The ORs increased with latency period with highest estimates using > 10 years time period from first use of these phone types. Lower ORs were calculated for astrocytoma grade I-II. No association was found with salivary gland tumours, NHL or testicular cancer although an association with NHL of T-cell type could not be ruled out.

Conclusion

We found for all studied phone types an increased risk for brain tumours, mainly acoustic neuroma and malignant brain tumours. OR increased with latency period, especially for astrocytoma grade III-IV. No consistent pattern of an increased risk was found for salivary gland tumours, NHL, or testicular cancer.     

Similar hypotensive responses to resistance exercise with and without blood flow restriction

Low intensity resistance exercise (RE) with blood flow restriction (BFR) has gained attention in the literature due to the beneficial effects on functional and morphological variables, similar to those observed during traditional RE without BFR, while the effects of BFR on post-exercise hypotension remain unclear. The aim of the present study was to compare the blood pressure (BP) response of trained normotensive individuals to RE with and without BFR. In this cross-over randomized trial, eight male subjects (23.8 ± 4 years, 74 ± 3 kg, 174 ± 4 cm) completed two exercise protocols: traditional RE (3 x 10 repetitions at 70% one-repetition maximum [1-RM]) and low intensity RE (3 x 15 repetitions at 20% 1-RM) with BFR. Blood pressure measurements were performed after 15 min of seated rest (0), immediately after and 10 min, 20 min, 30 min, 40 min, 50 min and 60 min after the experimental sessions. Similar hypotensive effects for systolic BP (SBP) were observed for both protocols (P < 0.05) after exercise, with no differences between groups (P > 0.05) and no statistically significant difference for diastolic BP (P > 0.05). These results suggest that in normotensive trained individuals, both traditional RE and RE with BFR induce hypotension for SBP, which is important to prevent cardiovascular disturbances.     

Disentangling the relative importance of climate,size and competition on tree growth in Iberian forests: implications for forest management under global change

Most large‐scale multispecies studies of tree growth have been conducted in tropical and cool temperate forests, whereas Mediterranean water‐limited ecosystems have received much less attention. This limits our understanding of how growth of coexisting tree species varies along environmental gradients in these forests, and the implications for species interactions and community assembly under current and future climatic conditions. Here, we quantify the absolute effect and relative importance of climate, tree size and competition as determinants of tree growth patterns in Iberian forests, and explore interspecific differences in the two components of competitive ability (competitive response and effect) along climatic and size gradients. Spatially explicit neighborhood models were developed to predict tree growth for the 15 most abundant Iberian tree species using permanent‐plot data from the Spanish Second and Third National Forest Inventory (IFN). Our neighborhood analyses showed a climatic and size effect on tree growth, but also revealed that competition from neighbors has a comparatively much larger impact on growth in Iberian forests. Moreover, the sensitivity to competition (i.e. competitive response) of target trees varied markedly along climatic gradients causing significant rank reversals in species performance, particularly under xeric conditions. We also found compelling evidence for strong species‐specific competitive effects in these forests. Altogether, these results constitute critical new information which not only furthers our understanding of important theoretical questions about the assembly of Mediterranean forests, but will also be of help in developing new guidelines for adapting forests in this climatic boundary to global change. If we consider the climatic gradients of this study as a surrogate for future climatic conditions, then we should expect absolute growth rates to decrease and sensitivity to competition to increase in most forests of the Iberian Peninsula (in all but the northern Atlantic forests), making these management considerations even more important in the future.     

Akt phosphorylates Sec24: new clues into the regulation of ER-to-Golgi trafficking

Regulation of protein transport within the early secretory pathway is a relatively unexplored area. Here, we propose a new player in the control of protein transport from the endoplasmic reticulum (ER) to the Golgi. Akt is an important signaling kinase whose functioning is perturbed in diseases such as cancer and diabetes. We discovered that Akt phosphorylates Sec24, an essential coat protein II (COPII) component involved in mediating cargo selection for ER-to-Golgi trafficking. We discuss how this finding may provide new insights into the regulation of protein transport.