High resolution dynamic mapping of the C. elegans intestinal brush border

The intestinal brush border is made of an array of microvilli that increases the membrane surface area for nutrient processing, absorption, and host defense. Studies on mammalian cultured epithelial cells uncovered some of the molecular players and physical constrains required to establish this apical specialized membrane. However, the building and maintenance of a brush border in vivo has not been investigated in detail yet. Here, we combined super-resolution imaging, transmission electron microscopy and genome editing in the developing nematode C. elegans to build a high-resolution and dynamic localization map of known and new brush border markers. Notably, we show that microvilli components are dynamically enriched at the apical membrane during microvilli outgrowth and maturation but become highly stable once microvilli are built. This new toolbox will be instrumental to understand the molecular processes of microvilli growth and maintenance in vivo as well as the effect of genetic perturbations, notably in the context of disorders affecting brush border integrity.

Balancing the Intestinal Microbiota to Treat Lower Gastrointestinal Diseases

Bacterial colonization is established by direct contact with maternal microorganisms immediately after birth, and may be affected during lactation. Increasing evidence shows that changes in the quantity and quality of the intestinal microbiota can help change the mucosal activation of the immune system, leading to intestinal or extraintestinal diseases. Throughout childhood and adolescence, the balance between pathogenic microbiota and beneficial microbiota is essential for gastrointestinal health, including the protection of pathogens, inhibition of pathogens, nutrient processing (vitamin K synthesis), and blood vessels where the stimulation of production and the regulation of host fat storage. Probiotics can promote the deliberate regulation of the intestinal microbiota, which is beneficial to the health of the host. The regulatory effects of intestinal microbiota on the prevention and adjuvant treatment of certain gastrointestinal diseases are reviewed.

High resolution dynamic mapping of the C. elegans intestinal brush border

The intestinal brush border is made of an array of microvilli that increases the membrane surface area for nutrient processing, absorption, and host defence. Studies on mammalian cultured epithelial cells uncovered some of the molecular players, structural components and physical constrains required to establish this apical specialized membrane. However, the building and maintenance of a brush border in vivo has not been investigated in detail yet. Here, we combined super-resolution imaging, transmission electron microscopy and genome editing in the developing nematode C. elegans to build a high-resolution and dynamic localization map of known and new markers of the brush border. Notably, we show that microvilli components are dynamically enriched at the apical membrane during microvilli outgrowth and maturation but become highly stable when microvilli are built. This new mapping tool will be instrumental to understand the molecular processes of microvilli growth and maintenance in vivo as well as the effect of genetic perturbations, notably in the context of disorders affecting the brush border integrity.

Gene Expression Analysis of Environmental Temperature and High-Fat Diet-Induced Changes in Mouse Supraclavicular Brown Adipose Tissue

Obesity, a dysregulation of adipose tissue, is a major health risk factor associated with many diseases. Brown adipose tissue (BAT)-mediated thermogenesis can potentially regulate energy expenditure, making it an attractive therapeutic target to combat obesity. Here, we characterize the effects of cold exposure, thermoneutrality, and high-fat diet (HFD) feeding on mouse supraclavicular BAT (scBAT) morphology and BAT-associated gene expression compared to other adipose depots, including the interscapular BAT (iBAT). scBAT was as sensitive to cold induced thermogenesis as iBAT and showed reduced thermogenic effect under thermoneutrality. While both scBAT and iBAT are sensitive to cold, the expression of genes involved in nutrient processing is different. The scBAT also showed less depot weight gain and more single-lipid adipocytes, while the expression of BAT thermogenic genes, such as Ucp1, remained similar or increased more under our HFD feeding regime at ambient and thermoneutral temperatures than iBAT. Together, these findings show that, in addition to its anatomical resemblance to human scBAT, mouse scBAT possesses thermogenic features distinct from those of other adipose depots. Lastly, this study also characterizes a previously unknown mouse deep neck BAT (dnBAT) depot that exhibits similar thermogenic characteristics as scBAT under cold exposure and thermoneutrality.

Intestinal AMPK modulation of microbiota mediates cross-talk with brown fat to control thermogenesis

The energy-dissipating capacity of brown adipose tissue through thermogenesis can be targeted to improve energy balance. Mammalian 5′-AMP-activated protein kinase (AMPK), a key nutrient sensor for maintaining cellular energy status, is a known therapeutic target for glucose control in Type II diabetes (T2D). Despite current understandings of its well-established roles in regulating glucose metabolism in various tissues, the functions of AMPK in the intestine, an organ for nutrient processing, remain largely unexplored. Using an intestinal epithelium-specific AMPK-null (AMPK-IKO) mouse model, we demonstrated that AMPK in the intestine communicated with brown adipose tissue (BAT) to promote thermogenesis. Mechanistically, we uncovered a novel link between intestinal AMPK activation and BAT thermogenic regulation through modulating the anti-microbial peptide (AMP)-controlled gut microbiota and the metabolites. Our findings identified a new AMPK-mediated mechanism of intestine-BAT communication that may partially underlie the therapeutic effects of AMPK activator metformin (N, N-dimethylbiguanide).

Organic soilless greenhouse systems.

This chapter discusses the organic soilless greenhouse systems. It includes topics on organic greenhouse production, organic hydroponic systems, organic hydroponic nutrients, microbial mineralization of organic nutrients for hydroponics, anaerobic and aerobic processing of organic materials, vermicast and vermicomposting, use of vermiculture liquids in hydroponics, composting for organic nutrient processing and substrate preparation, organic materials for vermicast, composting and biodigester systems, auqaponics, organic hydroponic production systems, biofilms in hydroponic systems, nutrient amendmentsorganic certification in the USA, organic pest and disease control, hybrid systems, and issues commonly encountered with organic hydroponic systems.

Organic soilless greenhouse systems.

This chapter discusses the organic soilless greenhouse systems. It includes topics on organic greenhouse production, organic hydroponic systems, organic hydroponic nutrients, microbial mineralization of organic nutrients for hydroponics, anaerobic and aerobic processing of organic materials, vermicast and vermicomposting, use of vermiculture liquids in hydroponics, composting for organic nutrient processing and substrate preparation, organic materials for vermicast, composting and biodigester systems, auqaponics, organic hydroponic production systems, biofilms in hydroponic systems, nutrient amendmentsorganic certification in the USA, organic pest and disease control, hybrid systems, and issues commonly encountered with organic hydroponic systems.

Impact of Intestinal Microbiota on Growth and Feed Efficiency in Pigs: A Review

This review summarises the evidence for a link between the porcine intestinal microbiota and growth and feed efficiency (FE), and suggests microbiota-targeted strategies to improve productivity. However, there are challenges in identifying reliable microbial predictors of host phenotype; environmental factors impact the microbe–host interplay, sequential differences along the intestine result in segment-specific FE- and growth-associated taxa/functionality, and it is often difficult to distinguish cause and effect. However, bacterial taxa involved in nutrient processing and energy harvest, and those with anti-inflammatory effects, are consistently linked with improved productivity. In particular, evidence is emerging for an association of Treponema and methanogens such as Methanobrevibacter in the small and large intestines and Lactobacillus in the large intestine with a leaner phenotype and/or improved FE. Bacterial carbohydrate and/or lipid metabolism pathways are also generally enriched in the large intestine of leaner pigs and/or those with better growth/FE. Possible microbial signalling routes linked to superior growth and FE include increased intestinal propionate production and reduced inflammatory response. In summary, the bacterial taxa and/or metabolic pathways identified here could be used as biomarkers for FE/growth in pigs, the taxa exploited as probiotics or the taxa/functionality manipulated via dietary/breeding strategies in order to improve productivity in pigs.