Adiponectin, also known as Acrp30, is an adipose tissue-derived hormone with anti-atherogenic, anti-diabetic and insulin sensitizing properties. Two seven-transmembrane domain-containing proteins, AdipoR1 and AdipoR2, have recently been identified as adiponectin receptors, yet signalling events downstream of these receptors remain poorly defined. By using the cytoplasmic domain of AdipoR1 as bait, we screened a yeast two-hybrid cDNA library derived from human fetal brain. This screening led to the identification of a phosphotyrosine binding domain and a pleckstrin homology domain-containing adaptor protein, APPL1 (adaptor protein containing pleckstrin homology domain, phosphotyrosine binding (PTB) domain and leucine zipper motif). APPL1 interacts with adiponectin receptors in mammalian cells and the interaction is stimulated by adiponectin. Overexpression of APPL1 increases, and suppression of APPL1 level reduces, adiponectin signalling and adiponectin-mediated downstream events (such as lipid oxidation, glucose uptake and the membrane translocation of glucose transport 4 (GLUT4)). Adiponectin stimulates the interaction between APPL1 and Rab5 (a small GTPase) interaction, leading to increased GLUT4 membrane translocation. APPL1 also acts as a critical regulator of the crosstalk between adiponectin signalling and insulin signalling pathways. These results demonstrate a key function for APPL1 in adiponectin signalling and provide a molecular mechanism for the insulin sensitizing function of adiponectin.

There is a clinical need for new, more effective treatments for chronic and debilitating inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis. In this study, we characterized a specific population of nanoparticles derived from edible ginger (GDNPs 2) and demonstrated their efficient colon targeting following oral administration. GDNPs 2 had an average size of ~230 nm and exhibited a negative zeta potential. These nanoparticles contained high levels of lipids, a few proteins, ~125 microRNAs (miRNAs), and large amounts of ginger bioactive constituents (6-gingerol and 6-shogaol). We also demonstrated that GDNPs 2 were mainly taken up by intestinal epithelial cells (IECs) and macrophages, and were nontoxic. Using different mouse colitis models, we showed that GDNPs 2 reduced acute colitis, enhanced intestinal repair, and prevented chronic colitis and colitis-associated cancer (CAC). 2D-DIGE/MS analyses further identified molecular target candidates of GDNPs 2 involved in these mouse models. Oral administration of GDNPs 2 increased the survival and proliferation of IECs and reduced the pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β), and increased the anti-inflammatory cytokines (IL-10 and IL-22) in colitis models, suggesting that GDNPs 2 has the potential to attenuate damaging factors while promoting the healing effect. In conclusion, GDNPs 2, nanoparticles derived from edible ginger, represent a novel, natural delivery mechanism for improving IBD prevention and treatment with an added benefit of overcoming limitations such as potential toxicity and limited production scale that are common with synthetic nanoparticles.

Gene silencing via orally delivered small interfering RNAs (siRNAs) represents a promising treatment strategy for numerous gastrointestinal (GI) diseases associated with chronic intestinal inflammation; however, the oral delivery of siRNA to inflamed isntestinal tissues remains a major challenge. Here, we present a delivery vehicle for siRNA, termed thioketal nanoparticles (TKNs), that can localize orally deliver siRNA to sites of intestinal inflammation, and thus inhibit gene expression in diseased intestinal tissue. TKNs are formulated from a new polymer, poly-(1,4-phenyleneacetone dimethylene thioketal) (PPADT), that degrades selectively in response to reactive oxygen species (ROS). Therefore, when delivered orally, TKNs release siRNA in response to the abnormally high levels of ROS specific to sites of intestinal inflammation1–3. Using a murine model of ulcerative colitis (UC), we demonstrate that orally administered TKNs loaded with siRNA against the proinflammatory cytokine tumor necrosis factor-alpha (TNFα) diminish TNFα messenger RNA (mRNA) levels in the colon and protect mice from UC.

Even though knowing the contributions of transpiration (T), soil and open water evaporation (E), and interception (I) to terrestrial evapotranspiration (ET = T + E + I) is crucial for understanding the hydrological cycle and its connection to ecological processes, the fraction of T is unattainable by traditional measurement techniques over large scales. Previously reported global mean T/(E + T + I) from multiple independent sources, including satellite‐based estimations, reanalysis, land surface models, and isotopic measurements, varies substantially from 24% to 90%. Here we develop a new ET partitioning algorithm, which combines global evapotranspiration estimates and relationships between leaf area index (LAI) and T/(E + T) for different vegetation types, to upscale a wide range of published site‐scale measurements. We show that transpiration accounts for about 57.2% (with standard deviation ± 6.8%) of global terrestrial ET. Our approach bridges the scale gap between site measurements and global model simulations,and can be simply implemented into current global climate models to improve biological CO2 flux simulations.

Hypothalamic nesfatin-1, derived from the nucleobindin2 (NUCB2) precursor, inhibits nocturnal food intake and body weight gain in rats. Nesfatin-1 is able to cross the blood-brain barrier, suggesting a peripheral source of nesfatin-1. Many centrally acting food intake regulatory neuropeptides are also produced in the periphery, especially in the gastrointestinal tract. Therefore, we investigated the gene expression of NUCB2 and distribution of nesfatin-1-immunoreactive cells in the stomach. Microarray mRNA expression profiles in purified small endocrine cells of the gastric mucosa substantiated by quantitative RT-PCR showed significantly higher NUCB2 mRNA expression compared with brain and heart. Western blot confirmed the expression of NUCB2 protein and its transport into a secretory soluble fraction of gastric mucosal endocrine cell homogenates. Immunohistochemical colabeling for nesfatin-1 and ghrelin, histidine decarboxylase, or somatostatin revealed two subtypes of nesfatin-1-positive endocrine cells. Cells in the midportion of the glands coexpressed nesfatin-1 and ghrelin, whereas few cells in the glandular base coexpressed nesfatin-1 and somatostatin or histidine decarboxylase. High-resolution three-dimensional volume imaging revealed two separate populations of intracytoplasmic vesicles in these cells, one containing nesfatin-1 and the other ghrelin immunoreactivity. Microarray rat genome expression data of NUCB2 in small gastric endocrine cells confirmed by quantitative RT-PCR showed significant down-regulation of NUCB2 after 24 h fasting. In summary, NUCB2 mRNA expression as well as protein content is present in a specific subset of gastric endocrine cells, most of which coexpress ghrelin. NUCB2 gene expression is significantly regulated by nutritional status, suggesting a regulatory role of peripheral nesfatin-1 in energy homeostasis.

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Nesfatin-1, derived from nucleobindin2, is expressed in the hypothalamus and reported in one study to reduce food intake (FI) in rats. To characterize the central anorexigenic action of nesfatin-1 and whether gastric emptying (GE) is altered, we injected nesfatin-1 into the lateral brain ventricle (intracerebroventricular, icv) or fourth ventricle (4v) in chronically cannulated rats or into the cisterna magna (intracisternal, ic) under short anesthesia and compared with ip injection. Nesfatin-1 (0.05 μg/rat, icv) decreased 2–3 h and 3–6 h dark-phase FI by 87 and 45%, respectively, whereas ip administration (2 μg/rat) had no effect. The corticotropin-releasing factor (CRF)1/CRF2 antagonist astressin-B or the CRF2 antagonist astressin2-B abolished icv nesfatin-1’s anorexigenic action, whereas an astressin2-B analog, devoid of CRF-receptor binding affinity, did not. Nesfatin-1 icv induced a dose-dependent reduction of GE by 26 and 43% that was not modified by icv astressin2-B. Nesfatin-1 into the 4v (0.05 μg/rat) or ic (0.5 μg/rat) decreased cumulative dark-phase FI by 29 and 60% at 1 h and by 41 and 37% between 3 and 5 h, respectively. This effect was neither altered by ic astressin2-B nor associated with changes in GE. Cholecystokinin (ip) induced Fos expression in 43% of nesfatin-1 neurons in the paraventricular hypothalamic nucleus and 24% of those in the nucleus tractus solitarius. These data indicate that nesfatin-1 acts centrally to reduce dark phase FI through CRF2-receptor-dependent pathways after forebrain injection and CRF2-receptor-independent pathways after hindbrain injection. Activation of nesfatin-1 neurons by cholecystokinin at sites regulating food intake may suggest a role in gut peptide satiation effect.

The eukaryotic circadian oscillators consist of autoregulatory negative-feedback loops. FRQ, WC-1, and WC-2 are three known components of the negative-feedback loop of the Neurospora circadian oscillator. FRQ represses its own transcription by interacting with the WC-1/WC-2 complex and inhibiting WC's role in transcriptional activation. Here we show that all FRQ associates with FRH, an essential DEAD box-containing RNA helicase in Neurospora. The budding yeast homolog of FRH, Dob1p/Mtr4p, is a cofactor of exosome, an important regulator of RNA metabolism in eukaryotes. Down-regulation of FRH by inducible expression of a hairpin RNA leads to low levels of FRQ but high levels of frq RNA and the abolishment of circadian rhythmicities. FRH is associated with the WC complex and this interaction is maintained in a frq null strain. Disruption of the FRQ-FRH complex by deleting a domain in FRQ eliminates the FRQ-WC interaction, suggesting that FRH mediates the interaction between FRQ and the WC complex. These data demonstrate that FRH is an essential component in the circadian negative-feedback loop and reveal an unexpected role of an RNA helicase in regulating gene transcription. Endogenous circadian (daily) clocks control a wide variety of physiological and molecular activities in most eukaryotic and some prokaryotic organisms. At the molecular level, autoregulatory negative-feedback loops composed of positive and negative elements form the core circadian oscillators (Dunlap 1999;King and Takahashi 2000;Reppert and Weaver 2001;Young and Kay 2001). The rhythmic activation of transcription of the negative elements by the positive elements is thought to be the main basis for the generation of the endogenous rhythmicity.In the Neurospora frequency (frq)-white collar (wc)-based circadian negative-feedback loop, a heterodimeric complex formed by WC-1 and WC-2 (two PAS domaincontaining transcription factors) acts as the positive element and activates the transcription of frq by binding to its promoter (Crosthwaite et al. 1997;Cheng et al. 2001b;Loros and Dunlap 2001;Froehlich et al. 2003). FRQ proteins (large FRQ [lFRQ] and small FRQ [sFRQ] resulting from alternative translation initiation) form homodimeric complexes and function as the negative elements in the loop by repressing their own transcription (Aronson et al. 1994a;Garceau et al. 1997;Liu et al. 1997;Cheng et al. 2001a). To close the negative-feedback loop, FRQ forms a complex with the WC proteins and prevents WC from binding to the frq promoter and activating frq transcription (Cheng et al. 2001a;Denault et al. 2001;Merrow et al. 2001;Froehlich et al. 2003). In strains lacking a functional FRQ protein, the negativefeedback loop is impaired, resulting in high frq mRNA levels (Aronson et al. 1994a;Merrow et al. 1997;. How FRQ inhibits the activity of WC complex is unclear. In frq null strains, in addition to their loss of circadian rhythmicities, less conidia and aerial hyphae are produced than a wild-type strain (Aronson et al. 1994b), suggesting that FRQ has funct...