Integrating management techniques to restore subtropical forests invaded by Hedychium coronarium J. Köenig (Zingiberaceae) in a biodiversity hotspot

The restoration of areas invaded by non‐native plants is challenging as invasive plants may affect both biotic and abiotic components of ecosystems, leading to impacts that constrain recolonization by native species after invaders are eliminated. In such a scenario, restoration techniques as topsoil transposition might accelerate colonization by native species in forests. Hedychium coronarium J. Koenig (Zingiberaceae) is a Himalayan herbaceous rhizomatous plant recognized as invasive in several countries. This study aimed to experimentally evaluate the response of plant assemblages to topsoil transposition on a site invaded by H. coronarium after chemical control. Four treatments were applied: chemical control integrated with topsoil transposition, chemical control of H. coronarium alone, topsoil transposition alone, and no intervention (control). Plots were evaluated prior to the application of treatments and then monthly for 11 months after treatments. Parameters were measured for H. coronarium (number of ramets, ramet height, and cover) and other species (species richness, abundance, and cover). Plots treated with chemical control (regardless of topsoil transposition) were similar in terms of all parameters measured and species composition, with dominance of herbs and shrubs. Plots managed solely with topsoil transposition had lower species richness, abundance, and cover, but more diverse life‐forms, being equally rich in climbers, trees, and herbs. Chemical control was effective to control invasion by H. coronarium and increase species richness and abundance on the managed site. Topsoil transposition promoted colonization by species that might accelerate restoration.     

Genetic and ecological consequences of recent habitat fragmentation in a narrow endemic plant species within an urban context

Understanding the timescales that shape spatial genetic structure is pivotal to ascertain the impact of habitat fragmentation on the genetic diversity and reproductive viability of long-lived plant populations. Combining genetic and ecological information with current and past fragmentation conditions allows the identification of the main drivers important in shaping population structure and declines in reproduction, which is crucial for informing conservation strategies. Using historic aerial photographs, we defined the past fragmentation conditions for the shrub Conospermum undulatum, a species now completely embedded in an urban area. We explored the impact of current and past conditions on its genetic layout and assessed the effects of genetic and environmental factors on its reproduction. The historically high structural connectivity was evident in the genetics of the species. Despite the current intense fragmentation, we found similar levels of genetic diversity across populations and a weak spatial genetic structure. Historical connectivity was negatively associated with genetic differentiation among populations and positively related to within-population genetic diversity. Variation partitioning of reproductive performance explained?~?66% of the variance, showing significant influences for genetic (9%), environmental (15%), and combined (42%) fractions. Our study highlights the importance of considering the historical habitat dynamics when investigating fragmentation consequences in long-lived plants. A detailed characterization of fragmentation from 1953 has shown how low levels of genetic fixation are due to extensive gene flow through the non-fragmented landscape. Moreover, knowledge of the relationships between genetic and environmental variation and reproduction can help to implement effective conservation strategies, particularly in highly dynamic landscapes.

     

Preliminary simulation model toward the study of the effects caused by different mandibular advancement devices in OSAS treatment

Abstract

The paper aims to evaluate the effects caused by a Mandibular Advancement Device (MAD) for Obstructive Sleep Apnoea Syndrome (OSAS) treatment. This study is based on Finite Element Method (FEM) for evaluating the load distribution on temporomandibular joint, especially on the mandibular condyle and disc, and on periodontal ligaments. The stress values on condyle and periodontal ligaments lead authors to consider MAD a safe procedure even for a long period. The obtained results also show the relationship between MAD material and load distribution at the periodontal ligaments. The paper is a step toward future analyses for studying and comparing the effects of MAD features, such as material, shape and dimensions, in order to allow the clinician prescribing the most fitting device.     

The Cytotoxic and Proapoptotic Activities of Hypnophilin are Associated with Calcium Signaling in UACC‐62 Cells

Hypnophilin (HNP) is a sesquiterpene that is isolated from Lentinus cf. strigosus and has cytotoxic activities. Here, we studied the calcium signaling and cytotoxic effects of HNP in UACC‐62 cells, a human skin melanoma cell line. HNP was able to increase the intracellular calcium concentration in UACC‐62 cells, which was blocked in cells stimulated in Ca²⁺‐free media. HNP treatment with BAPTA‐AM, an intracellular Ca²⁺ chelator, caused an increase in calcium signals. HNP showed cytotoxicity against UACC‐62 cells in which it induced DNA fragmentation and morphological alterations, including changes in the nuclear chromatin profile and increased cytoplasmatic vacuolization, but it had no effect on the plasma membrane integrity. These data suggest that cytotoxicity in UACC‐62 cells, after treatment with HNP, is associated with Ca²⁺ influx. Together, these findings suggest that HNP is a relevant tool for the further investigation of new anticancer approaches. © 2013 Wiley Periodicals, Inc. J BiochemMol Toxicol 27:479‐485, 2013; View this article online at wileyonlinelibrary.com . DOI 10.1002/jbt.21507     

Direct inhibition of hexokinase activity by metformin at least partially impairs glucose metabolism and tumor growth in experimental breast cancer

Emerging evidence suggests that metformin, a widely used anti-diabetic drug, may be useful in the prevention and treatment of different cancers. In the present study, we demonstrate that metformin directly inhibits the enzymatic function of hexokinase (HK) I and II in a cell line of triple-negative breast cancer (MDA-MB-231). The inhibition is selective for these isoforms, as documented by experiments with purified HK I and II as well as with cell lysates. Measurements of ¹⁸F-fluoro-deoxyglycose uptake document that it is dose- and time-dependent and powerful enough to virtually abolish glucose consumption despite unchanged availability of membrane glucose transporters. The profound energetic imbalance activates phosphorylation and is subsequently followed by cell death. More importantly, the “in vivo” relevance of this effect is confirmed by studies of orthotopic xenografts of MDA-MB-231 cells in athymic (nu/nu) mice. Administration of high drug doses after tumor development caused an evident tumor necrosis in a time as short as 48 h. On the other hand, 1 mo metformin treatment markedly reduced cancer glucose consumption and growth. Taken together, our results strongly suggest that HK inhibition contributes to metformin therapeutic and preventive potential in breast cancer.     

Brood Ball-Mediated Transmission of Microbiome Members in the Dung Beetle,Onthophagus taurus (Coleoptera: Scarabaeidae)

Insects feeding on plant sap, blood, and other nutritionally incomplete diets are typically associated with mutualistic bacteria that supplement missing nutrients. Herbivorous mammal dung contains more than 86% cellulose and lacks amino acids essential for insect development and reproduction. Yet one of the most ecologically necessary and evolutionarily successful groups of beetles, the dung beetles (Scarabaeinae) feeds primarily, or exclusively, on dung. These associations suggest that dung beetles may benefit from mutualistic bacteria that provide nutrients missing from dung. The nesting behaviors of the female parent and the feeding behaviors of the larvae suggest that a microbiome could be vertically transmitted from the parental female to her offspring through the brood ball. Using sterile rearing and a combination of molecular and culture-based techniques, we examine transmission of the microbiome in the bull-headed dung beetle, Onthophagus taurus. Beetles were reared on autoclaved dung and the microbiome was characterized across development. A ~1425 bp region of the 16S rRNA identified Pseudomonadaceae, Enterobacteriaceae, and Comamonadaceae as the most common bacterial families across all life stages and populations, including cultured isolates from the 3^rd instar digestive system. Finer level phylotyping analyses based on lepA and gyrB amplicons of cultured isolates placed the isolates closest to Enterobacter cloacae, Providencia stuartii, Pusillimonas sp., Pedobacter heparinus, and Lysinibacillus sphaericus. Scanning electron micrographs of brood balls constructed from sterile dung reveals secretions and microbes only in the chamber the female prepares for the egg. The use of autoclaved dung for rearing, the presence of microbes in the brood ball and offspring, and identical 16S rRNA sequences in both parent and offspring suggests that the O. taurus female parent transmits specific microbiome members to her offspring through the brood chamber. The transmission of the dung beetle microbiome highlights the maintenance and likely importance of this newly-characterized bacterial community.     

Alcohol Impairs Predation Risk Response and Communication in Zebrafish

The effects of ethanol exposure on Danio rerio have been studied from the perspectives of developmental biology and behavior. However, little is known about the effects of ethanol on the prey-predator relationship and chemical communication of predation risk. Here, we showed that visual contact with a predator triggers stress axis activation in zebrafish. We also observed a typical stress response in zebrafish receiving water from these conspecifics, indicating that these fish chemically communicate predation risk. Our work is the first to demonstrate how alcohol effects this prey-predator interaction. We showed for the first time that alcohol exposure completely blocks stress axis activation in both fish seeing the predator and in fish that come in indirect contact with a predator by receiving water from these conspecifics. Together with other research results and with the translational relevance of this fish species, our data points to zebrafish as a promising animal model to study human alcoholism.     

Bisphenol-A Impairs Insulin Action and Up-Regulates Inflammatory Pathways in Human Subcutaneous Adipocytes and 3T3-L1 Cells

Current evidence indicates that chemical pollutants may interfere with the homeostatic control of nutrient metabolism, thereby contributing to the increased prevalence of metabolic disorders. Bisphenol-A (BPA) is a lipophilic compound contained in plastic which is considered a candidate for impairing energy and glucose metabolism. We have investigated the impact of low doses of BPA on adipocyte metabolic functions. Human adipocytes derived from subcutaneous adipose tissue and differentiated 3T3-L1 cells were incubated with BPA, in order to evaluate the effect on glucose utilization, insulin sensitivity and cytokine secretion. Treatment with 1nM BPA significantly inhibited insulin-stimulated glucose utilization, without grossly interfering with adipocyte differentiation. Accordingly, mRNA levels of the adipogenic markers PPARγ and GLUT4 were unchanged upon BPA exposure. BPA treatment also impaired insulin-activated receptor phosphorylation and signaling. Moreover, adipocyte incubation with BPA was accompanied by increased release of IL-6 and IFN-γ, as assessed by multiplex ELISA assays, and by activation of JNK, STAT3 and NFkB pathways. Treatment of the cells with the JNK inhibitor SP600125 almost fully reverted BPA effect on insulin signaling and glucose utilization. In conclusion, low doses of BPA interfere with inflammatory/insulin signaling pathways, leading to impairment of adipose cell function.