Baculovirus-based gene silencing of Humanin for the treatment of pituitary tumors

Pituitary tumors are the most common primary intracranial neoplasms. Humanin (HN) and Rattin (HNr), a rat homolog of HN, are short peptides with a cytoprotective action. In the present study, we aimed to evaluate whether endogenous HNr plays an antiapoptotic role in pituitary tumor cells. Thus, we used RNA interference based on short-hairpin RNA (shRNA) targeted to HNr (shHNr). A plasmid including the coding sequences for shHNr and dTomato fluorescent reporter gene was developed (pUC-shHNr). Transfection of somatolactotrope GH3 cells with pUC-shHNr increased apoptosis, suggesting that endogenous HNr plays a cytoprotective role in pituitary tumor cells. In order to evaluate the effect of blockade of endogenous HNr expression in vivo, we constructed a recombinant baculovirus (BV) encoding shHNr (BV-shHNr). In vitro, BV-shRNA was capable of transducing more than 80% of GH3 cells and decreased HNr mRNA. Also, BV-shHNr increased apoptosis in transduced GH3 cells. Intratumor injection of BV-shHNr to nude mice bearing s.c. GH3 tumors increased the number of apoptotic cells, delayed tumor growth and enhanced survival rate, suggesting that endogenous HNr may be involved in pituitary tumor progression. These preclinical data suggests that the silencing of HN expression could have a therapeutic impact on the treatment of pituitary tumors.     

Bacteroides fragilis Toxin Coordinates a Pro-carcinogenic Inflammatory Cascade via Targeting of Colonic Epithelial Cells

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<Emphasis Type="Italic">Paenibacillus</Emphasis> sp. A59 GH10 and GH11 Extracellular Endoxylanases: Application in Biomass Bioconversion

The cost-efficient degradation of xylan to fermentable sugars is of particular interest in second generation bioethanol production, feed, food, and pulp and paper industries. Multiple potentially secreted enzymes involved in polysaccharide deconstruction are encoded in the genome of Paenibacillus sp. A59, a xylanolytic soil bacterium, such as three endoxylanases, seven GH43 β-xylosidases, and two GH30 glucuronoxylanases. In secretome analysis of xylan cultures, ten glycoside hydrolases were identified, including the three predicted endoxylanases, confirming their active role. The two uni-modular xylanases, a 32-KDa GH10 and a 20-KDa GH11, were recombinantly expressed and their activity on xylan was confirmed (106 and 85 IU/mg, respectively), with differences in their activity pattern. Both endoxylanases released mainly xylobiose (X2) and xylotriose (X3) from xylan and pre-treated biomasses (wheat straw, barley straw, and sweet corn cob), although only rGH10XynA released xylose (X1). rGH10XynA presented optimal conditions at pH 6, with thermal stability at 45–50 °C, while rGH11XynB showed activity in a wider range of pH, from 5 to 9, and was thermostable only at 45 °C. Moreover, GH11XynB presented sigmoidal kinetics on xylan, indicating possible cooperative binding, which was further supported by the structural model. This study provides a detailed analysis of the complete set of carbohydrate-active enzymes encoded in Paenibacillus sp. A59 genome and those effectively implicated in hemicellulose hydrolysis, contributing to understanding the mechanisms necessary for the bioconversion of this polysaccharide. Moreover, the two main free secreted xylanases, rGH10XynA and rGH11XynB, were fully characterized, supporting their potential application in industrial bioprocesses on lignocellulosic biomass.     

Ultrastructure of euspermatozoa and paraspermatozoa in the marine gastropod Adelomelon beckii (Caenogastropoda, Volutidae)

The sperm morphology of Adelomelon beckii is described by optical and transmission electron microscopy. Both euspermatozoa and paraspermatozoa were found in the specimens studied. Euspermatozoa are filiform and have an elongate nucleus capped by an acrosome. A small basal plate lies between the base of the acrosome and the nucleus. The mid-piece consists of U-shaped mitochondria wrapped helically around the central axoneme. A dense annulus at the junction of the mid-piece and glycogen piece is found, ending in a short end-piece, composed of the axoneme surrounded by a plasma membrane. Two types of paraspermatozoa are found, both vermiform but differing internally with respect to the disposition and number of axonemes, as well as to the types of secretory vesicles. We suggest the use of paraspermatozoa as a systematic character to reveal phylogenetic relationships in this family.     

Differential activation of a frontoparietal network explains population-level differences in statistical learning from speech

People of all ages display the ability to detect and learn from patterns in seemingly random stimuli. Referred to as statistical learning (SL), this process is particularly critical when learning a spoken language, helping in the identification of discrete words within a spoken phrase. Here, by considering individual differences in speech auditory–motor synchronization, we demonstrate that recruitment of a specific neural network supports behavioral differences in SL from speech. While independent component analysis (ICA) of fMRI data revealed that a network of auditory and superior pre/motor regions is universally activated in the process of learning, a frontoparietal network is additionally and selectively engaged by only some individuals (high auditory–motor synchronizers). Importantly, activation of this frontoparietal network is related to a boost in learning performance, and interference with this network via articulatory suppression (AS; i.e., producing irrelevant speech during learning) normalizes performance across the entire sample. Our work provides novel insights on SL from speech and reconciles previous contrasting findings. These findings also highlight a more general need to factor in fundamental individual differences for a precise characterization of cognitive phenomena.

In the context of speech, statistical learning is thought to be an important mechanism for language acquisition. This study shows that language statistical learning is boosted by the recruitment of a fronto-parietal brain network related to auditory-motor synchronization and its interplay with a mandatory auditory-motor learning system.     

Early Woody Invasion Under Tree Plantations in Costa Rica: Implications for Forest Restoration

The role of tree plantations as facilitators of tropical forest restoration in degraded lands has been explored recently, but there are few data on the effect of different tree species on invasion of the plant understory. We evaluated early patterns of understory composition in three-year-old native tree plantations in lowland Costa Rica using two pure-species treatment (Jacaranda copaia and Vochysia guatemalensis) and one mixed-species treatment (J. copaia, V. guatemalensis, Stryphnodendron microstachyum, and Calophyllum brasiliense). We also monitored woody invasion in unplanted control areas dominated by grasses. The understory of the different plantation treatments differed in light environment, woody-plant growth and recruitment, and quantity and quality of woody regeneration. Forest tree invasion appeared to be enhanced under Vochysia, while shrubs were more abundant under the Jacaranda and mixed-species treatments. Woody plant growth, herbaceous cover, and understory light availability were highest under Jacaranda, intermediate under mixed species, and lowest under Vochysia. Soil-stored seeds seemed an important source for woody plant recruitment in Jacaranda and mixed species and of minimal importance under Vochysia, probably due to light suppression. It appears that competition from grasses is a major factor influencing early woody invasion in our study area. We found no woody recruitment after one year in the unplanted controls. We suggest that to promote the use of plantations as tools of forest restoration, there is a need to gather basic ecological information on how different tree species may influence patterns of plant understory colonization.     

Induction of osteoclastogenesis in an in vitro model of Gaucher disease is mediated by T cells via TNF-α

Gaucher disease is a lysosomal storage disorder caused by deficiency of glucocerebrosidase enzymatic activity leading to accumulation of its substrate glucocerebrosidase mainly in macrophages. Skeletal disorder of Gaucher disease is the major cause of morbidity and is highly refractory to enzyme replacement therapy. However, pathological mechanisms of bone alterations in Gaucher disease are still poorly understood. We hypothesized that cellular alteration in Gaucher disease produces a proinflammatory milieu leading to bone destruction through enhancement of monocyte differentiation to osteoclasts and osteoclasts resorption activity. Against this background we decided to investigate in an in vitro chemical model of Gaucher disease, the capacity of secreted soluble mediators to induce osteoclastogenesis, and the mechanism responsible for this phenomena. We demonstrated that soluble factors produced by CBE-treated PBMC induced differentiation of osteoclasts precursors into mature and active osteoclasts that express chitotriosidase and secrete proinflammatory cytokines. We also showed a role of TNF-α in promoting osteoclastogenesis in Gaucher disease chemical model. To analyze the biological relevance of T cells in osteoclastogenesis of Gaucher disease, we investigated this process in T cell-depleted PBMC cultures. The findings suggest that T cells play a role in osteoclast formation in Gaucher disease. In conclusion, our data suggests that in vitro GCASE deficiency, along with concomitant glucosylceramide accumulation, generates a state of osteoclastogenesis mediated in part by pro-resorptive cytokines, especially TNF-α. Moreover, T cells are involved in osteoclastogenesis in Gaucher disease chemical model.