The global Microcystis interactome Cook, Katherine V.; Li, Chuang; Cai, Haiyuan ...
Limnology and oceanography,
January 2020, Letnik:
65, Številka:
S1
Journal Article
Recenzirano
Odprti dostop
Bacteria play key roles in the function and diversity of aquatic systems, but aside from study of specific bloom systems, little is known about the diversity or biogeography of bacteria associated ...with harmful cyanobacterial blooms (cyanoHABs). CyanoHAB species are known to shape bacterial community composition and to rely on functions provided by the associated bacteria, leading to the hypothesized cyanoHAB interactome, a coevolved community of synergistic and interacting bacteria species, each necessary for the success of the others. Here, we surveyed the microbiome associated with Microcystis aeruginosa during blooms in 12 lakes spanning four continents as an initial test of the hypothesized Microcystis interactome. We predicted that microbiome composition and functional potential would be similar across blooms globally. Our results, as revealed by 16S rRNA sequence similarity, indicate that M. aeruginosa is cosmopolitan in lakes across a 280° longitudinal and 90° latitudinal gradient. The microbiome communities were represented by a wide range of operational taxonomic units and relative abundances. Highly abundant taxa were more related and shared across most sites and did not vary with geographic distance, thus, like Microcystis, revealing no evidence for dispersal limitation. High phylogenetic relatedness, both within and across lakes, indicates that microbiome bacteria with similar functional potential were associated with all blooms. While Microcystis and the microbiome bacteria shared many genes, whole-community metagenomic analysis revealed a suite of biochemical pathways that could be considered complementary. Our results demonstrate a high degree of similarity across global Microcystis blooms, thereby providing initial support for the hypothesized Microcystis interactome.
Rhizosphere microbiota has received much attention due to their associations with plant growth and their fundamental importance in terrestrial ecosystems. However, relatively few studies have focused ...on rhizosphere microbial communities associated with aquatic macrophytes in freshwater lakes. We hypothesized that the rhizosphere microbiome would reflect the presence of macrophyte roots and the concomitant microhabitat conditions the roots create. Here, high-throughput sequencing and network analysis were employed to compare the composition and structure of bacterial communities in the rhizosphere of two common emergent macrophytes, Zizania latifolia and Phragmites australis, with the surrounding sediments in Lake Taihu (China). Results indicated that bacterial diversity, community composition, and co-occurrence networks differed between the communities of bulk sediments and the communities of rhizosphere and surface sediments. Richness and phylogenetic diversity were higher and more taxa were enriched in the rhizosphere and surface sediment communities compared with bulk sediment communities. No differences were detected between bacterial communities in rhizosphere and surface sediments, nor between rhizospheres sediment communities of the two macrophyte species. Anaerobic taxa were more abundant in bulk sediment communities. Among the co-occurrence networks, more nodes (operational taxonomic units) and edges (connections) with higher average degree as well as more topologically important nodes were found in rhizosphere and surface sediment communities relative to bulk communities. These findings suggest that rhizosphere microbiome communities are influenced by the presence of macrophyte roots, with oxygenated rhizosphere and surface sediment communities being more diverse, and organized into more interconnected co-occurrence networks.
Cyanobacteria are the most prevalent bloom-forming harmful algae in freshwater systems around the world. Adequate sampling of affected systems is limited spatially, temporally, and fiscally. Remote ...sensing using space- or ground-based systems in large water bodies at spatial and temporal scales that are cost-prohibitive to standard water quality monitoring has proven to be useful in detecting and quantifying cyanobacterial harmful algal blooms. This study aimed to identify a regional ‘universal’ multispectral reflectance model that could be used for rapid, remote detection and quantification of cyanoHABs in small- to medium-sized productive reservoirs, such as those typical of Oklahoma, USA. We aimed to include these small waterbodies in our study as they are typically overlooked in larger, continental wide studies, yet are widely distributed and used for recreation and drinking water supply. We used Landsat satellite reflectance and in-situ pigment data spanning 16 years from 38 reservoirs in Oklahoma to construct empirical linear models for predicting concentrations of chlorophyll-a and phycocyanin, two key algal pigments commonly used for assessing total and cyanobacterial algal abundances, respectively. We also used ground-based hyperspectral reflectance and in-situ pigment data from seven reservoirs across five years in Oklahoma to build multispectral models predicting algal pigments from newly defined reflectance bands. Our Oklahoma-derived Landsat- and ground-based models outperformed established reflectance-pigment models on Oklahoma reservoirs. Importantly, our results demonstrate that ground-based multispectral models were far superior to Landsat-based models and the Cyanobacteria Index (CI) for detecting cyanoHABs in highly productive, small- to mid-sized reservoirs in Oklahoma, providing a valuable tool for water management and public health. While satellite-based remote sensing approaches have proven effective for relatively large systems, our novel results indicate that ground-based remote sensing may offer better cyanoHAB monitoring for small or highly dendritic turbid lakes, such as those throughout the southern Great Plains, and thus prove beneficial to efforts aimed at minimizing public health risks associated with cyanoHABs in supply and recreational waters.
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Despite advances in treatment strategies, breast cancer (BC) remains one of the most prevalent cancers worldwide. Recent studies implicate the gut microbiome as a potential risk factor for BC ...development. Alterations in gut microbial diversity resulting in dysbiosis have been linked to breast carcinogenesis by modulating host immune responses and inflammatory pathways, favoring tumorigenesis and progression. Moreover, gut microbiota populations are different between women with BC vs those that are cancer free, further implicating the role of the gut microbiome in cancer development. This alteration in gut microbiota is also associated with changes in estrogen metabolism, which strongly correlates with BC development. Gut microbiota that express the enzyme β-glucuronidase (GUS) may increase estrogen bioavailability by deconjugating estrogen-glucuronide moieties enabling reabsorption into circulation. Increased circulating estrogens may, in turn, drive estrogen receptor-positive BC. GUS-expressing microbiota also affect cancer therapy efficacy and toxicity by modifying glucuronide-conjugated drug metabolites. Therefore, GUS inhibitors have emerged as a potential antitumor treatment. However, the effectiveness of GUS inhibitors is still exploratory. Further studies are needed to determine how oral endocrine-targeting therapies may influence or be influenced by the microbiota and how that may affect carcinogenesis initiation and tumor recurrence.
Recent identification of a mammary gland-specific microbiome led to studies investigating bacteria populations in breast cancer. Malignant breast tumors have lower Lactobacillus abundance compared ...with benign lesions, implicating Lactobacillus as a negative regulator of breast cancer. Diet is a main determinant of gut microbial diversity. Whether diet affects breast microbiome populations is unknown. In a non-human primate model, we found that consumption of a Western or Mediterranean diet modulated mammary gland microbiota and metabolite profiles. Mediterranean diet consumption led to increased mammary gland Lactobacillus abundance compared with Western diet-fed monkeys. Moreover, mammary glands from Mediterranean diet-fed monkeys had higher levels of bile acid metabolites and increased bacterial-processed bioactive compounds. These data suggest that diet directly influences microbiome populations outside the intestinal tract in distal sites such as the mammary gland. Our study demonstrates that diet affects the mammary gland microbiome, establishing an alternative mechanistic pathway for breast cancer prevention.
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•Diet modulates mammary gland microbiota populations in a non-human primate model•Consumption of Mediterranean diet elevates mammary gland Lactobacillus abundance•Mediterranean diet increases breast bile acid and bacterial-modified metabolites•Consumption of Mediterranean diet decreases reactive oxygen species metabolites
Using a non-human primate model of women’s health, Shively et al. demonstrate that diet plays a critical role in determining microbiota populations in tissues outside the gut, such as the mammary gland. These microbial populations modulate localized bile acid and bacterial-modified metabolites to potentially influence anticancer signaling pathways.
Diet is a modifiable component of lifestyle that could influence breast cancer development. The Mediterranean dietary pattern is considered one of the healthiest of all dietary patterns. Adherence to ...the Mediterranean diet protects against diabetes, cardiovascular disease, and cancer. Reported consumption of a Mediterranean diet pattern was associated with lower breast cancer risk for women with all subtypes of breast cancer, and a Western diet pattern was associated with greater risk. In this review, we contrast the available epidemiological breast cancer data, comparing the impact of consuming a Mediterranean diet to the Western diet. Furthermore, we will review the preclinical data highlighting the anticancer molecular mechanism of Mediterranean diet consumption in both cancer prevention and therapeutic outcomes. Diet composition is a major constituent shaping the gut microbiome. Distinct patterns of gut microbiota composition are associated with the habitual consumption of animal fats, high-fiber diets, and vegetable-based diets. We will review the impact of Mediterranean diet on the gut microbiome and inflammation. Outside of the gut, we recently demonstrated that Mediterranean diet consumption led to distinct microbiota shifts in the mammary gland tissue, suggesting possible anticancer effects by diet on breast-specific microbiome. Taken together, these data support the anti-breast-cancer impact of Mediterranean diet consumption.
Despite advances in cancer therapy, several persistent issues remain. These include cancer recurrence, effective targeting of aggressive or therapy-resistant cancers, and selective treatments for ...transformed cells. This review evaluates the current findings and highlights the potential of targeting the unfolded protein response to treat cancer. The unfolded protein response, an evolutionarily conserved pathway in all eukaryotes, is initiated in response to misfolded proteins accumulating within the lumen of the endoplasmic reticulum. This pathway is initially cytoprotective, allowing cells to survive stressful events; however, prolonged activation of the unfolded protein response also activates apoptotic responses. This balance is key in successful mammalian immune response and inducing cell death in malignant cells. We discuss how the unfolded protein response affects cancer progression, survival, and immune response to cancer cells. The literature shows that targeting the unfolded protein response as a monotherapy or in combination with chemotherapy or immunotherapies increases the efficacy of these drugs; however, systemic unfolded protein response targeting may yield deleterious effects on immune cell function and should be taken into consideration. The material in this review shows the promise of both approaches, each of which merits further research.
Angiotensin-(1-7) Ang-(1-7) is an endogenous 7-amino acid peptide hormone of the renin-angiotensin system that has antiproliferative properties. In this study, Ang-(1-7) inhibited the growth of ...cancer-associated fibroblasts (CAF) and reduced fibrosis in the tumor microenvironment. A marked decrease in tumor volume and weight was observed in orthotopic human breast tumors positive for the estrogen receptor (BT-474 or ZR-75-1) and HER2 (BT-474) following Ang-(1-7) administration to athymic mice. Ang-(1-7) concomitantly reduced interstitial fibrosis in association with a significant decrease in collagen I deposition, along with a similar reduction in perivascular fibrosis. In CAFs isolated from orthotopic breast tumors, the heptapeptide markedly attenuated in vitro growth as well as reduced fibronectin, transforming growth factor-β (TGF-β), and extracellular signal-regulated kinase 1/2 kinase activity. An associated increase in the mitogen-activated protein kinase (MAPK) phosphatase DUSP1 following treatment with Ang-(1-7) suggested a potential mechanism by which the heptapeptide reduced MAPK signaling. Consistent with these in vitro observations, immunohistochemical analysis of Ang-(1-7)-treated orthotopic breast tumors revealed reduced TGF-β and increased DUSP1. Together, our findings indicate that Ang-(1-7) targets the tumor microenvironment to inhibit CAF growth and tumor fibrosis.
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