Of mutualism and migration: will interactions with novel ericoid mycorrhizal communities help or hinder northward Rhododendron range shifts?

AbstractRapid climate change imperils many small-ranged endemic species as the climate envelopes of their native ranges shift poleward. In addition to abiotic changes, biotic interactions are expected to play a critical role in plant species’ responses. Below-ground interactions are of particular interest given increasing evidence of microbial effects on plant performance and the prevalence of mycorrhizal mutualisms. We used greenhouse mesocosm experiments to investigate how natural northward migration/assisted colonization of Rhododendron catawbiense, a small-ranged endemic eastern U.S. shrub, might be influenced by novel below-ground biotic interactions from soils north of its native range, particularly with ericoid mycorrhizal fungi (ERM). We compared germination, leaf size, survival, and ERM colonization rates of endemic R. catawbiense and widespread R. maximum when sown on different soil inoculum treatments: a sterilized control; a non-ERM biotic control; ERM communities from northern R. maximum populations; and ERM communities collected from the native range of R. catawbiense. Germination rates for both species when inoculated with congeners' novel soils were significantly higher than when inoculated with conspecific soils, or non-mycorrhizal controls. Mortality rates were unaffected by treatment, suggesting that the unexpected reciprocal effect of each species’ increased establishment in association with heterospecific ERM could have lasting demographic effects. Our results suggest that seedling establishment of R. catawbiense in northern regions outside its native range could be facilitated by the presence of extant congeners like R. maximum and their associated soil microbiota. These findings have direct relevance to the potential for successful poleward migration or future assisted colonization efforts.

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Exosomal miR-214-5p Released from Glioblastoma Cells Modulates Inflammatory Response of Microglia after Lipopolysaccharide Stimulation through Targeting CXCR5

CNS & Neurological Disorders - Drug Targets ◽

10.2174/1871527317666181105112009 ◽

2019 ◽

Vol 18 (1) ◽

pp. 78-87 ◽

Cited By ~ 7

Author(s):

Jian-kai Yang ◽

Hong-jiang Liu ◽

Yuanyu Wang ◽

Chen Li ◽

Ji-peng Yang ◽

...

Keyword(s):

Inflammatory Response ◽

Critical Role ◽

Luciferase Reporter ◽

Clinical Prognosis ◽

Direct Target ◽

And Migration ◽

High Level ◽

Cxcr5 Expression ◽

Proliferation And Migration

Background and Objective: Exosomes communicate inter-cellularly and miRNAs play critical roles in this scenario. MiR-214-5p was implicated in multiple tumors with diverse functions uncovered. However, whether miR-214-5p is mechanistically involved in glioblastoma, especially via exosomal pathway, is still elusive. Here we sought to comprehensively address the critical role of exosomal miR-214-5p in glioblastoma (GBM) microenvironment.Methods:The relative expression of miR-214-5p was determined by real-time PCR. Cell viability and migration were measured by MTT and transwell chamber assays, respectively. The secretory cytokines were measured with ELISA kits. The regulatory effect of miR-214-5p on CXCR5 expression was interrogated by luciferase reporter assay. Protein level was analyzed by Western blot.Results:We demonstrated that miR-214-5p was aberrantly overexpressed in GBM and associated with poorer clinical prognosis. High level of miR-214-5p significantly contributed to cell proliferation and migration. GBM-derived exosomal miR-214-5p promoted inflammatory response in primary microglia upon lipopolysaccharide challenge. We further identified CXCR5 as the direct target of miR-214- 5p in this setting.Conclusion:Overexpression of miR-214-5p in GBM modulated the inflammatory response in microglia via exosomal transfer.

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MIR21-induced loss of junctional adhesion molecule A promotes activation of oncogenic pathways, progression and metastasis in colorectal cancer

Cell Death and Differentiation ◽

10.1038/s41418-021-00820-0 ◽

2021 ◽

Author(s):

Andrea Lampis ◽

Jens C. Hahne ◽

Pierluigi Gasparini ◽

Luciano Cascione ◽

Somaieh Hedayat ◽

...

Keyword(s):

Colorectal Cancer ◽

Critical Role ◽

Tumour Volume ◽

Cell Permeability ◽

Oncogenic Pathways ◽

Morphogenetic Protein ◽

Cancer Phenotype ◽

And Migration ◽

2D And 3D

AbstractJunctional adhesion molecules (JAMs) play a critical role in cell permeability, polarity and migration. JAM-A, a key protein of the JAM family, is altered in a number of conditions including cancer; however, consequences of JAM-A dysregulation on carcinogenesis appear to be tissue dependent and organ dependent with significant implications for the use of JAM-A as a biomarker or therapeutic target. Here, we test the expression and prognostic role of JAM-A downregulation in primary and metastatic colorectal cancer (CRC) (n = 947). We show that JAM-A downregulation is observed in ~60% of CRC and correlates with poor outcome in four cohorts of stages II and III CRC (n = 1098). Using JAM-A knockdown, re-expression and rescue experiments in cell line monolayers, 3D spheroids, patient-derived organoids and xenotransplants, we demonstrate that JAM-A silencing promotes proliferation and migration in 2D and 3D cell models and increases tumour volume and metastases in vivo. Using gene-expression and proteomic analyses, we show that JAM-A downregulation results in the activation of ERK, AKT and ROCK pathways and leads to decreased bone morphogenetic protein 7 expression. We identify MIR21 upregulation as the cause of JAM-A downregulation and show that JAM-A rescue mitigates the effects of MIR21 overexpression on cancer phenotype. Our results identify a novel molecular loop involving MIR21 dysregulation, JAM-A silencing and activation of multiple oncogenic pathways in promoting invasiveness and metastasis in CRC.

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Fungi and plant co-variation in Arctic Siberia inferred from sedimentary ancient DNA metabarcoding during the last 45.000 years

10.5194/egusphere-egu21-14604 ◽

2021 ◽

Author(s):

Barbara von Hippel ◽

Kathleen R. Stoof-Leichsenring ◽

Luise Schulte ◽

Peter Seeber ◽

Laura S. Epp ◽

...

Keyword(s):

Climate Change ◽

Ancient Dna ◽

Mycorrhizal Fungi ◽

Vegetation Change ◽

Sediment Cores ◽

Siberian Larch ◽

Biotic Interactions ◽

Arctic Ecosystems ◽

Arctic Regions ◽

Arctic Siberia

<p>Climate change has a great impact on boreal ecosystems including Siberian larch forests. As a consequence of warming, larch grow is possible in areas where climate used to be too cold, leading to a shift of the tree line into more arctic regions. Most plants co-exist in symbiosis with heterotrophic organisms surrounding their root system. In arctic ecosystems, mycorrhizal fungi are a prerequisite for plant establishment and survival because they support nutrient uptake from nutrient-poor soils and maintain the water supply. Until now, however, knowledge about the co-variation of vegetation and fungi is poor. Certainly, the understanding of dynamic changes in biotic interactions is important to understand adaptation mechanisms of ecosystems to climate change.</p><p>We investigated sedimentary ancient DNA from Lake Levinson Lessing, Taymyr Peninsula (Arctic Siberia, tundra), Lake Lama, Lake Kyutyunda (both northern Siberia, tundra-taiga transition zone) and Lake Bolshoe Toko (southern Siberia, forest area) covering the last about 45.000 years using ITS primers for fungi along with the chloroplast P6 loop marker for vegetation metabarcoding. We found changes in the fungal communities that are in broad agreement with vegetation turnover. To our knowledge, this is the first broad ecological study on lake sediment cores to analyze fungal biodiversity in relation to vegetation change on millennial time scales.</p>

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Agricultural intensification reduces microbial network complexity and the abundance of keystone taxa in roots

10.1101/416271 ◽

2018 ◽

Cited By ~ 1

Author(s):

Samiran Banerjee ◽

Florian Walder ◽

Lucie Büchi ◽

Marcel Meyer ◽

Alain Y. Held ◽

...

Keyword(s):

Organic Farming ◽

Mycorrhizal Fungi ◽

Agricultural Intensification ◽

Soil Phosphorus ◽

Farming Systems ◽

Wheat Root ◽

Plant Performance ◽

No Till ◽

The Impact ◽

Root Microbiota

AbstractRoot-associated microbes play a key role in plant performance and productivity, making them important players in agroecosystems. So far, very few studies have assessed the impact of different farming systems on the root microbiota and it is still unclear whether agricultural intensification influences network complexity of microbial communities. We investigated the impact of conventional, no-till and organic farming on wheat root fungal communities usingPacBio SMRT sequencingon samples collected from 60 farmlands in Switzerland. Organic farming harboured a much more complex fungal network than conventional and no-till farming systems. The abundance of keystone taxa was the highest under organic farming where agricultural intensification was the lowest. The occurrence of keystone taxa was best explained by soil phosphorus levels, bulk density, pH and mycorrhizal colonization. The majority of keystone taxa are known to form arbuscular mycorrhizal associations with plants and belong to the ordersGlomerales,Paraglomerales, andDiversisporales. Supporting this, the abundance of mycorrhizal fungi in roots and soils was also significantly higher under organic farming. To our knowledge, this is the first study to report mycorrhizal keystone taxa for agroecosystems, and we demonstrate that agricultural intensification reduces network complexity and the abundance of keystone taxa in the root microbiota.

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Critical role of WNK1 in MYC-dependent early mouse thymocyte development

eLife ◽

10.7554/elife.56934 ◽

2020 ◽

Vol 9 ◽

Author(s):

Robert Köchl ◽

Lesley Vanes ◽

Miriam Llorian Sopena ◽

Probir Chakravarty ◽

Harald Hartweger ◽

...

Keyword(s):

Critical Role ◽

Ion Homeostasis ◽

Thymocyte Development ◽

Double Positive ◽

Mouse Thymocyte ◽

Proliferation And Differentiation ◽

Tcr Signals ◽

And Migration ◽

Early Mouse

WNK1, a kinase that controls kidney salt homeostasis, also regulates adhesion and migration in CD4+ T cells. Wnk1 is highly expressed in thymocytes, and since migration is important for thymocyte maturation, we investigated a role for WNK1 in mouse thymocyte development. We find that WNK1 is required for the transition of double negative (DN) thymocytes through the β-selection checkpoint and subsequent proliferation and differentiation into double positive (DP) thymocytes. Furthermore, we show that WNK1 negatively regulates LFA1-mediated adhesion and positively regulates CXCL12-induced migration in DN thymocytes. Despite this, migration defects of WNK1-deficient thymocytes do not account for the developmental arrest. Instead, we show that in DN thymocytes WNK1 transduces pre-TCR signals via OXSR1 and STK39 kinases, and the SLC12A2 ion co-transporter that are required for post-transcriptional upregulation of MYC and subsequent proliferation and differentiation into DP thymocytes. Thus, a pathway regulating ion homeostasis is a critical regulator of thymocyte development.

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Divergence in bidirectional plant-soil feedbacks between montane annual and coastal perennial ecotypes of yellow monkeyflower (Mimulus guttatus)

10.1101/2020.12.02.408245 ◽

2020 ◽

Author(s):

Mariah M. McIntosh ◽

Lorinda Bullington ◽

Ylva Lekberg ◽

Lila Fishman

Keyword(s):

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Plant Performance ◽

Fungal Communities ◽

Mechanistic Study ◽

List Type ◽

Mimulus Guttatus ◽

Plant Variation ◽

Plant Soil ◽

Soil Origin

SUMMARYUnderstanding the physiological and genetic mechanisms underlying plant variation in interactions with root-associated biota (RAB) requires a micro-evolutionary approach. We use locally adapted montane annual and coastal perennial ecotypes of Mimulus guttatus (yellow monkeyflower) to examine population-scale differences in plant-RAB-soil feedbacks.We characterized fungal communities for the two ecotypes in-situ and used a full-factorial greenhouse experiment to investigate the effects of plant ecotype, RAB source, and soil origin on plant performance and endophytic root fungal communities.The two ecotypes harbored different fungal communities and responsiveness to soil biota was highly context-dependent. Soil origin, RAB source, and plant ecotype all affected the intensity of biotic feedbacks on plant performance. Feedbacks were primarily negative, and we saw little evidence of local adaptation to either soils or RAB. Both RAB source and soil origin significantly shaped fungal communities in roots of experimental plants. Further, the perennial ecotype was more colonized by arbuscular mycorrhizal fungi (AMF) than the montane ecotype, and preferentially recruited home AMF taxa.Our results suggest life history divergence and distinct edaphic habitats shape plant responsiveness to RAB and influence specific associations with potentially mutualistic root endophytic fungi. Our results advance the mechanistic study of intraspecific variation in plant–soil–RAB interactions.

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Below-ground biotic interactions moderated the postglacial range dynamics of trees

New Phytologist ◽

10.1111/nph.15203 ◽

2018 ◽

Vol 220 (4) ◽

pp. 1148-1160 ◽

Cited By ~ 16

Author(s):

Jason Pither ◽

Brian J. Pickles ◽

Suzanne W. Simard ◽

Alejandro Ordonez ◽

John W. Williams

Keyword(s):

Biotic Interactions ◽

Below Ground ◽

Range Dynamics

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Abstract 363: Lim Domain Only 4 Is a Shear-Sensitive Protein, Playing a Critical Role in Endothelial Inflammation and Atherosclerosis

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.32.suppl_1.a363 ◽

2012 ◽

Vol 32 (suppl_1) ◽

Author(s):

Wakako Takabe ◽

Chih-Wen Ni ◽

Dong Ju Son ◽

Noah Alberts-Grill ◽

Hanjoong Jo

Keyword(s):

Endothelial Cells ◽

Shear Stress ◽

Critical Role ◽

Oscillatory Shear ◽

Lim Domain ◽

Disturbed Flow ◽

Endothelial Inflammation ◽

And Migration ◽

Oscillatory Shear Stress ◽

Stable Flow

Recently, we have shown that disturbed flow, characterized by low and oscillatory shear stress, caused by a partial ligation of mouse left carotid artery (LCA) rapidly induces atherosclerosis. Using the partial ligation model and genome-wide microarray study with aortic endothelial RNAs obtained directly from the flow-disturbed carotid arteries, we previously identified mechanosensitive genes in mouse endothelial RNA including LIM domain only 4 ( lmo4 ). Here we report that LMO4 is a shear-sensitive protein that regulates endothelial inflammation. Lmo4 was up-regulated by disturbed flow in mouse LCA compared to the contralateral right CA (RCA) exposed to stable flow. At protein levels, LMO4 expression was significantly higher not only in LCA in our surgical model but also in the lesser curvature (flow-disturbed and athero-prone region of mouse aortic arch) compared to the greater curvature (stable-flow and ather-protected region). In addition, immunohistochemical staining of LMO4 in human coronary arteries revealed that its expression is detectable only in intimal endothelial cells, but not in medial cells. While LMO4 is known as a potential oncogene and associated with growth, migration and invasion of breast cancer cells, its role in cardiovascular system is not known to our knowledge. We tested a hypothesis that LMO4 is a mechanosensitive gene and plays a critical role in regulation of endothelial cell biology. LMO4 protein expression was robustly induced by oscillatory shear stress (OS) compared to laminar shear (LS) in human umbilical vein endothelial cells (HUVEC). Treatment of HUVEC with siRNA against LMO4 significantly inhibited OS-induced inflammation and migration, but not apoptosis and cell cycle progression. Further, LMO4 siRNA treatment significantly blunted expression of VCAM-1 and interleukin-8 induced by OS in endothelial cells. These results suggest that LMO4 is a shear-induced gene that plays a critical role in OS-induced endothelial inflammation and migration, and potentially in atherosclerosis.

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Abstract 15691: The Novel High Mobility Group Protein Hmgxb4 Promotes Neointimal Formation in Response to Arterial Injury

Circulation ◽

10.1161/circ.142.suppl_3.15691 ◽

2020 ◽

Vol 142 (Suppl_3) ◽

Author(s):

xiangqin he ◽

Kunzhe Dong ◽

Jian Shen ◽

Islam Osman ◽

Guoqing Hu ◽

...

Keyword(s):

Smooth Muscle ◽

Neointimal Hyperplasia ◽

Critical Role ◽

High Mobility ◽

Arterial Injury ◽

The Novel ◽

Neointimal Formation ◽

Vsmc Proliferation ◽

And Migration

Introduction: Restenosis after percutaneous intervention is predominantly attributed to proliferation and migration of vascular smooth muscle cells (VSMCs). However, the key regulators responsible for VSMC proliferation and migration remain to be identified. Hypothesis: We previously reported that the novel high mobility group (HMG) nuclear protein HMGXB4 (HMG-Box containing 4) plays a critical role in the de-differentiation of vascular smooth muscle cells in vitro and in acute inflammatory response to septic shock. We hypothesize that HMGXB4 is critical for neointimal hyperplasia in response to inflammatory stimuli. Methods and Results: We found that the expression of HMGXB4 is dramatically induced in ligation or wire injury-induced neointimal hyperplasia and correlated with the activation of inflammatory signaling in mice. Using an inducible smooth muscle-specific Hmgxb4 KO (knockout) mice model, we found specific KO of Hmgxb4 in VSMCs ameliorates ligation- or wire- injury induced neointimal formation. Among an array of growth factors and inflammation cytokines, we found that TNFα and INFγ effectively induces the expression of HMGXB4 in VSMCs and correlates with the VSMC proliferation in vitro. Furthermore, we found deletion of HMGXB4 attenuates while over-expression of HMGXB4 promotes inflammation cytokines-induced VSMC proliferation in vitro. These results suggest injury-induced inflammatory signal triggers HMGXB4 induction, which, in turn, promotes the VSMC proliferation and neointimal formation. Conclusions: Our study not only demonstrates a critical role of HMGXB4 in promoting neointimal hyperplasia in response the arterial injury, but also suggests HMGXB4 is a potential novel target for the management of restenosis in human.

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Aberrant ALOX5 Activation Correlates with HER2 Status and Mediates Breast Cancer Biological Activities through Multiple Mechanisms

BioMed Research International ◽

10.1155/2020/1703531 ◽

2020 ◽

Vol 2020 ◽

pp. 1-8

Author(s):

Xiao Zhou ◽

Yi Jiang ◽

Qiuyun Li ◽

Zhen Huang ◽

Huawei Yang ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Cells ◽

Breast Cancer Cells ◽

Biological Activities ◽

Critical Role ◽

Her2 Overexpression ◽

Her2 Positive ◽

Mesenchymal Transition ◽

And Migration ◽

Expression And Activity

Arachidonate lipoxygenases (ALOX) have been implicated in playing a critical role in tumorigenesis, development, and metastasis. We previously reported that ALOX12 is involved in breast cancer chemoresistance. In this study, we demonstrate that the ALOX5 activation correlates with the HER2 expression and mediates breast cancer growth and migration. We found that the ALOX5 expression and activity were upregulated in breast cancer patients, particularly in those tissues with HER2-positive. ALOX5 upregulation was also observed in HER2-positive breast cancer cells. In contrast, HER2 inhibition led to decreased expression and activity of ALOX5 but not ALOX5AP, suggesting that HER2 specifically regulates the ALOX5 expression and activity in breast cancer cells. We further demonstrated that ALOX5 is important for breast cancer biological activities with the predominant roles in growth and migration, likely through RhoA, focal adhesion, and PI3K/Akt/mTOR signaling but not epithelial mesenchymal transition (EMT). Our work is the first to report a correlation between the ALOX5 activity and HER2 overexpression in breast cancer. Our findings also highlight the therapeutic value of inhibiting ALOX5 in breast cancer, particularly those patients with the HER2 overexpression.

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