Rock-eating mycorrhizas: their role in plant nutrition and biogeochemical cycles

A decade ago, tunnels inside mineral grains were found that were likely formed by hyphae of ectomycorrhizal (EcM) fungi. This observation implied that EcM fungi can dissolve mineral grains. The observation raised several questions on the ecology of these ¿rock-eating¿ fungi. This review addresses the roles of these rock-eating EcM associations in plant nutrition, biogeochemical cycles and pedogenesis. Research approaches ranged from molecular to ecosystem level scales. Nutrient deficiencies change EcM seedling exudation patterns of organic anions and thus their potential to mobilise base cations from minerals. This response was fungal species-specific. Some EcM fungi accelerated mineral weathering. While mineral weathering could also increase the concentrations of phytotoxic aluminium in the soil solution, some EcM fungi increase Al tolerance through an enhanced exudation of oxalate. Through their contribution to Al transport, EcM hyphae could be agents in pedogenesis, especially podzolisation. A modelling study indicated that mineral tunnelling is less important than surface weathering by EcM fungi. With both processes taken together, the contribution of EcM fungi to weathering may be significant. In the field vertical niche differentiation of EcM fungi was shown for EcM root tips and extraradical mycelium. In the field EcM fungi and tunnel densities were correlated. Our results support a role of rock-eating EcM fungi in plant nutrition and biogeochemical cycles. EcM fungal species-specific differences indicate the need for further research with regard to this variation in functional traits

Targeting the NG2/CSPG4 Proteoglycan Retards Tumour Growth and Angiogenesis in Preclinical Models of GBM and Melanoma

Aberrant expression of the progenitor marker Neuron-glia 2 (NG2/CSPG4) or melanoma proteoglycan on cancer cells and angiogenic vasculature is associated with an aggressive disease course in several malignancies including glioblastoma multiforme (GBM) and melanoma. Thus, we investigated the mechanism of NG2 mediated malignant progression and its potential as a therapeutic target in clinically relevant GBM and melanoma animal models. Xenografting NG2 overexpressing GBM cell lines resulted in increased growth rate, angiogenesis and vascular permeability compared to control, NG2 negative tumours. The effect of abrogating NG2 function was investigated after intracerebral delivery of lentivirally encoded shRNAs targeting NG2 in patient GBM xenografts as well as in established subcutaneous A375 melanoma tumours. NG2 knockdown reduced melanoma proliferation and increased apoptosis and necrosis. Targeting NG2 in two heterogeneous GBM xenografts significantly reduced tumour growth and oedema levels, angiogenesis and normalised vascular function. Vascular normalisation resulted in increased tumour invasion and decreased apoptosis and necrosis. We conclude that NG2 promotes tumour progression by multiple mechanisms and represents an amenable target for cancer molecular therapy

Addressing climate change with behavioral science: a global intervention tournament in 63 countries

Effectively reducing climate change requires marked, global behavior change. However, it is unclear which strategies are most likely to motivate people to change their climate beliefs and behaviors. Here, we tested 11 expert-crowdsourced interventions on four climate mitigation outcomes: beliefs, policy support, information sharing intention, and an effortful tree-planting behavioral task. Across 59,440 participants from 63 countries, the interventions’ effectiveness was small, largely limited to nonclimate skeptics, and differed across outcomes: Beliefs were strengthened mostly by decreasing psychological distance (by 2.3%), policy support by writing a letter to a future-generation member (2.6%), information sharing by negative emotion induction (12.1%), and no intervention increased the more effortful behavior—several interventions even reduced tree planting. Last, the effects of each intervention differed depending on people’s initial climate beliefs. These findings suggest that the impact of behavioral climate interventions varies across audiences and target behaviors

An electrochemiluminescence based assay for quantitative detection of endogenous and exogenously applied MeCP2 protein variants

Methyl-CpG-binding protein 2 (MeCP2) is a multifunctional chromosomal protein that plays a key role in the central nervous system. Its levels need to be tightly regulated, as both deficiency and excess of the protein can lead to severe neuronal dysfunction. Loss-of-function mutations affecting MeCP2 are the primary cause of Rett syndrome (RTT), a severe neurological disorder that is thought to result from absence of functional protein in the brain. Several therapeutic strategies for the treatment of RTT are currently being developed. One of them is the use of stable and native TAT-MeCP2 fusion proteins to replenish its levels in neurons after permeation across the blood-brain barrier (BBB). Here we describe the expression and purification of various transactivator of transcription (TAT)-MeCP2 variants and the development of an electrochemiluminescence based assay (ECLIA) that is able to measure endogenous MeCP2 and recombinant TAT-MeCP2 fusion protein levels in a 96-well plate format. The MeCP2 ECLIA produces highly quantitative, accurate and reproducible measurements with low intra- and inter-assay error throughout a wide working range. To underline its broad applicability, this assay was used to analyze brain tissue and study the transport of TAT-MeCP2 variants across an in vitro model of the blood-brain barrier

Perilesional edema in brain metastasis from non-small cell lung cancer (NSCLC) as predictor of response to radiosurgery (SRS)

Radiosurgery (SRS) is widely used in the treatment of brain oligo-metastases from NSCLC. The aim of present study is to evaluate the extent of perilesional edema in brain metastases as predictive factor of treatment response. This single center retrospective study included 42 consecutive patients (January 2011–December 2014) with 1–2 brain metastasis from NSCLC treated with Radiosurgery (SRS). Extent of perilesional edema was measured as maximal extension from the edge of lesion and classified as minor (<10 mm) or major (≥10 mm). We analyzed Modality of Brain Recurrence (MBR), classified as in-field or out-of- field, and Brain Progression Free-Survival (BPFS) after treatment stratified according to extent of perilesional edema. Analyzing modality of brain recurrence and BPFS, after a median follow-up of 6 months, we found that patients with minor edema had a better radiological response to SRS with none in-field recurrences and a lower risk of the onset of new brain lesions (out-of-field recurrence). Instead, patients group with major edema had a worse response rate of lesions treated, further, a higher risk of out-of-field brain relapse. Extent of perilesional edema in brain metastasis from NSCLC could be a predictive factor of response and brain progression after SRS treatment alone

Extent of peritumoral brain edema correlates with prognosis, tumoral growth pattern, HIF1a expression and angiogenic activity in patients with single brain metastases

To analyze the prognostic value of the extent of peritumoral brain edema in patients operated for single brain metastases (BM), we retrospectively evaluated pre-operative magnetic resonance images in a discovery cohort of 129 patients and a validation cohort of 118 patients, who underwent neurosurgical resection of a single BM in two different hospitals. We recorded clinical parameters and immunohistochemically assessed the Ki67 index, the microvascularization patterns and the expression of hypoxia-induced factor 1 alpha (HIF1a) in the BM tissue specimens retrieved at neurosurgery. Statistical analysis including uni- and multivariate survival analyses were performed. Baseline characteristics were well balanced between the discovery and validation cohorts. In univariate analysis, we found a significant association of favorable overall survival time with young patient age, high Karnofsky performance score, low graded prognostic assessment (GPA) class, absence of extracranial metastases, adjuvant treatment with whole brain radiotherapy and, surprisingly, large brain edema. In multivariate analysis, only GPA and extent of brain edema remained independent prognostic parameters. The prognostic impact of the extent of brain edema was consistent in the two patient cohorts. Furthermore, we found a significant correlation of small brain edema with brain-invasive tumor growth pattern as assessed intraoperatively by the neurosurgeon, low neo-angiogenic activity and low expression of HIF1a. Extent of brain edema independently correlates with prognosis in patients operated for single BM. In conclusion, patients with small peritumoral edema have shorter survival times and their tumors are characterized by a more brain-invasive growth, lower HIF1a expression and less angiogenic activity