Expression of the Metalloproteinase ADAM8 Is Upregulated in Liver Inflammation Models and Enhances Cytokine Release In Vitro.

Acute and chronic liver inflammation is driven by cytokine and chemokine release from various cell types in the liver. Here, we report that the induction of inflammatory mediators is associated with a yet undescribed upregulation of the metalloproteinase ADAM8 in different murine hepatitis models. We further show the importance of ADAM8 expression for the production of inflammatory mediators in cultured liver cells. As a model of acute inflammation, we investigated liver tissue from lipopolysaccharide- (LPS-) treated mice in which ADAM8 expression was markedly upregulated compared to control mice. In vitro, stimulation with LPS enhanced ADAM8 expression in murine and human endothelial and hepatoma cell lines as well as in primary murine hepatocytes. The enhanced ADAM8 expression was associated with an upregulation of TNF-α and IL-6 expression and release. Inhibition studies indicate that the cytokine response of hepatoma cells to LPS depends on the activity of ADAM8 and that signalling by TNF-α can contribute to these ADAM8-dependent effects. The role of ADAM8 was further confirmed with primary hepatocytes from ADAM8 knockout mice in which TNF-α and IL-6 induction and release were considerably attenuated. As a model of chronic liver injury, we studied liver tissue from mice undergoing high-fat diet-induced steatohepatitis and again observed upregulation of ADAM8 mRNA expression compared to healthy controls. In vitro, ADAM8 expression was upregulated in hepatoma, endothelial, and stellate cell lines by various mediators of steatohepatitis including fatty acid (linoleic-oleic acid), IL-1ß, TNF-α, IFN-γ, and TGF-ß. Upregulation of ADAM8 was associated with the induction and release of proinflammatory cytokines (TNF-α and IL-6) and chemokines (CX3CL1). Finally, knockdown of ADAM8 expression in all tested cell types attenuated the release of these mediators. Thus, ADAM8 is upregulated in acute and chronic liver inflammation and is able to promote inflammation by enhancing expression and release of inflammatory mediators.

Foraging behavior and bait station preference in scavenging termite, Odontotermes obesus (Blattodea: Termitidae).

Termites are a significant pest of buildings, agriculture, and trees, and are mainly controlled by baiting. However, baiting systems are available for only lower termites (Rhinotermitidae) not for higher termites (Termitidae). Termite foraging behavior associated with baiting systems varies among species and families, and plays a significant role in baiting success. Here, foraging behavior of Odontotermes obesus (Blattodea: Termitidae: Macrotermitinae), a fungus-growing higher termite, was investigated relative to three bait-station sizes (small, medium, and large) containing different quantities of food. Significantly more workers recruited to large stations (470/station) compared to medium (246/station) and small (124/station) stations. Abundance of O. obesus in large and medium stations significantly positively correlated with relative humidity whereas negative but non-significant correlations were observed with temperature in large and medium stations. Total and continuous contacts with the stations increased with time and were greater in large stations. Station abandonment due to disturbance was significantly less in large stations (3%) followed by medium (9%) and small stations (20%). Our results suggest that large stations (≈8 litres volume) work best for population management of O. obesus and other related fungus-growing higher termites.

Assemblage of pollinator communities in four widely isolated nature reserves of southern Punjab, Pakistan.

Pollinators are key components of the global biodiversity, providing vital ecosystem services of pollination to crops and wild plants. Understanding pollinator assemblage and how it changes spatially is important in order to device effective ecosystem management planning. This is the first empirical study to explore pollinator community structure in four widely isolated nature reserves of southern Punjab, Pakistan, i.e., the central agricultural plain (Pirowal Forest), the Indus delta plain (Ghazi Ghat Wetland), hilly mountains (Fort Munro), and a sandy desert (Lal Suhanra Forest). Six assemblage parameters, i.e., abundance, richness, dominance, evenness, Simpson index, and Shannon-Wiener index, were studied over seven consecutive months (February to August 2012). Maximum abundance and richness of the pollinators were recorded at Ghazi Ghat (1354 individuals and 84 species), followed by Pirowal (1331 individuals and 80 species), Lal Suhanra (1197 individuals and 77 species), and Fort Munro (808 individuals and 65 species). The highest values of Simpson and evenness indexes were recorded at Fort Munro, while the Shannon-Wiener and dominance indexes were highest at Ghazi Ghat and Pirowal. Species richness was highest for bees, while it was lowest for flies, yet the latter were the highest in abundance among the four pollinator groups. The current study is a first account of pollinator assemblage structure in four widely isolated forest reserves of Punjab, Pakistan. This will support ecosystem management planning, and opens doors for further research in order to reveal complexities in pollinator assemblage structure especially in relation with plant communities.

Role of pollination in yield and physicochemical properties of tomatoes (Lycopersicon esculentum).

Very little is known about pollination and its effects on the yield and physicochemical properties of flowering plants in tropical countries. Wind and insect pollinators are among our natural resources because pollination is the most important ecosystem service performed by wind and insects, and is vital to the socio-economic status of human beings. In this experiment, different pollination methods for tomato plants were examined. Self-pollination was encouraged by covering the plants with a plastic sheet. Wind and insects were excluded from these plants, and thus only self-pollination was possible. The experiment occurred during the flowering stage. Wind-pollinated plants were covered with a muslin cloth, which excluded insects, and only wind could pass through the cloth. For insect pollination, plants remained uncovered, allowing free access to insects to pollinate the flowers. At fruit maturity, when fruits were completely red, fruits from each treatment were harvested on the same date and under the same conditions. Results illustrated the substantial importance of insects as pollinators of tomato crops. Open field had greater tomato yield and positive effects on physicochemical properties on fruit than under self and wind pollination.

Motor innervation pattern of labral muscles of Locusta migratoria.

The current study investigates the motor innervation pattern of labral muscles in the adult locust and tries to interpret the results in the light of the hypothesis that the labrum phylogenetically developed by the fusion of paired appendages associated with the intercalary segment. Using Neurobiotin™ as a retrograde neuronal tracer, specific motor nerves or individual labral muscles were stained. Results show that the labral muscles receive innervation from tritocerebrum and suboesophageal ganglion. The axons of many motor neurons use three different pathways to cross the midline in the periphery to innervate ipsi- and contralateral muscles. Intracellular recordings from fibers of individual muscles and simultaneous recordings from motor neurons imply that the labral muscles lack inhibitory innervation. The location of motor neurons in both tritocerebrum and suboesophageal ganglion supports the notion that the labrum is innervated by the so-called intercalary segment. That many of the efferent axons cross the midline in the periphery might be explained by the hypothesis that the labrum derives from a fusion of appendages.