Pathological angiogenesis in retinopathy engages cellular senescence and is amenable to therapeutic elimination via BCL-xL inhibition

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Sialic acids as cellular markers of immunomodulatory action of dexamethasone on glioma cells of different immunogenicity

Molecular and Cellular Biochemistry - Glucocorticosteroids, including dexamethasone (Dex), are commonly used to control tumor-induced edema in the brain tumor patients. There are increasing...     

An invasive fish promotes invasive plants in Minnesota lakes

1. Biological invasions can greatly alter ecological communities, affecting not only the diversity and abundance but also composition of invaded assemblages. This is because invaders’ impacts are mediated by characteristics of resident species: some may be highly sensitive to invader impacts while others are unaffected or even facilitated. In some cases, this can result in invasive species promoting further invasions; in particular, herbivory by introduced animals has been shown to disproportionately harm native plants, which can indirectly benefit non-native plants. Here, we investigated whether such patterns emerged through the effects of an invasive fish species on lake plant communities.
2. Specifically, we tested whether invasion of Minnesota (U.S.A.) lakes by Cyprinus carpio (common carp), an omnivorous, benthivorous fish known to reduce abundance and richness of aquatic plants, differentially affected native versus non-native plant species. We applied statistical models to a large, long-term monitoring dataset (206 macrophyte taxa recorded in 913 lakes over a 20-year time period) to test whether carp altered community composition, to identify which macrophyte species were most sensitive to carp and determine whether species characteristics predicted carp sensitivity, and to characterise consequences of carp invasion on lake-level vegetation attributes.
3. We found that carp exerted strong selective pressure on community composition. Native macrophytes, those with a more aquatic growth form, and those considered less tolerant of disturbance (i.e. higher coefficients of conservatism) were more sensitive to carp. Conversely, no introduced macrophytes exhibited sensitivity to carp and all had higher probabilities of occurrence as carp abundance increased. The net effect of carp invasion was a shift toward less species-rich plant communities characterised by more non-native and disturbance-tolerant species.
4. These results have several implications for conservation and management. First, they reinforce the need to prevent further spread of carp outside of their native range. Where carp have already established, their control should be incorporated into efforts to restore aquatic vegetation; this may be an essential step for recovering particular plant species of high conservation importance. Furthermore, reducing carp abundance could have ancillary benefits of reducing dominance by invasive plant species. Lastly, where carp cannot be eliminated, managers should target native macrophytes that are relatively tolerant of carp in shoreline plantings and other revegetation efforts.

     

Effects of a rapidly increasing population of common carp on vegetative cover and waterfowl in a recently restored Midwestern shallow lake

Although the common carp (Cyprinus carpio), an invasive benthic fish from Eurasia, has long been strongly implicated in the disappearance of vegetative cover and reduced waterfowl abundance in North American shallow lakes, the details of this relationship are obscure. This study documented ecological changes in a recently restored shallow lake (Hennepin and Hopper Lakes, IL, USA) at a time that it was experiencing a large increase in its carp population. We estimated the abundance and biomass of carp 7 years after this lake had been restored and then back-calculated carp population size across time while examining changes in the lake’s plant and waterfowl communities. We found that the biomass of carp remained below ~30 kg/ha for 5 years following restoration, but then increased to ~100 kg/ha in the sixth year following a strong recruitment event. Although a carp biomass of <30 kg/ha had no discernible effects on vegetative cover (which exceeded 90%) or waterfowl (which exceeded 150,000 individuals during fall censuses), the increase to 100 kg/ha was associated with a ~50% decrease in both vegetative cover and waterfowl. A further increase in carp biomass to over 250 kg/ha during the seventh year coincided with a decrease in the vegetative cover to 17% of the lake’s surface and a decline in waterfowl use to ~10% of its original value. These data suggest that the common carp is extremely damaging to the ecological integrity of shallow lakes when its density exceeds ~100 kg/ha. Since the biomass of carp in Midwestern shallow lakes commonly exceeds this value by 3–4 times, it seems likely that carp are responsible for the large-scale habitat deterioration described in many of these ecosystems. Handling editor: J. Cambray     

PPARg2 Ala12 variant protects against Graves' orbitopathy and modulates the course of the disease

Orbital fibroblast differentiation to adipocytes is a peroxisome proliferator-activated receptor g (PPARg)-dependent process essential for pathogenic tissue remodeling in Graves' orbitopathy (GO). PPARg2 Pro¹²Ala polymorphism modulates expression and/or function of the molecule encoded by this gene and is a promising locus of GO. Here, we analyzed associations of PPARg2 Pro¹²Ala with clinical manifestation of GO in 742 Polish Caucasians including 276 Graves' disease (GD) patients. In our study, the Ala¹² allele and Ala¹² variant (Ala¹²Ala and/or Pro¹²Ala genotype) decreased the risk of GO (p?=?0.000012 and p?=?0.00013). Moreover, Ala¹²Ala genotype was observed only in patients without GO (p?=?0.002). GD patients with Ala¹² variant had less active and less severe eye symptoms. Female carriers of the Ala¹² allele rarely developed GO, but the marker was not related to symptoms of GO. The opposite finding was recorded in males, in whom the studied polymorphism was related to activity, but not to the development, of GO. In Ala¹² variant carriers without familial history of thyroid disease, risk of GO was lower than in persons with a familial background. The Ala¹² allele seemed to protect smokers from GO, but in nonsmokers, such a relation was not obvious. A multivariate analysis indicated the Pro¹²Ala marker as an independent risk factor of eye symptoms (p?=?0.0001) and lack of Ala increases the risk of GO 3.24-fold. In conclusion, the gain-of-function Ala¹² variant protects against GO and modulates the course of the disease.