Effects of myeloid sirtuin 1 deficiency on hypothalamic neurogranin in mice fed a high-fat diet

Hypothalamic inflammation has been known as a contributor to high-fat diet (HFD)-induced insulin resistance and obesity. Myeloid-specific sirtuin 1 (SIRT1) deletion aggravates insulin resistance and hypothalamic inflammation in HFD-fed mice. Neurogranin, a calmodulin-binding protein, is expressed in the hypothalamus. However, the effects of myeloid SIRT1 deletion on hypothalamic neurogranin has not been fully clarified. To investigate the effect of myeloid SIRT1 deletion on food intake and hypothalamic neurogranin expression, mice were fed a HFD for 20 weeks. Myeloid SIRT1 knockout (KO) mice exhibited higher food intake, weight gain, and lower expression of anorexigenic proopiomelanocortin in the arcuate nucleus than WT mice. In particular, KO mice had lower ventromedial hypothalamus (VMH)-specific neurogranin expression. However, SIRT1 deletion reduced HFD-induced hypothalamic neurogranin. Furthermore, hypothalamic phosphorylated AMPK and parvalbumin protein levels were also lower in HFD-fed KO mice than in HFD-fed WT mice. Thus, these findings suggest that myeloid SIRT1 deletion affects food intake through VMH-specific neurogranin-mediated AMPK signaling and hypothalamic inflammation in mice fed a HFD.     

Split-enzyme fragment as a single affinity tag that enables protein expression,purification, and functional assays

Expressing, isolating, and characterizing recombinant proteins is crucial to many disciplines within the biological sciences. Different molecular tagging technologies have been developed to enable each individual step of protein production, from expression through purification and characterization. Monitoring the entire production process requires multiple tags or molecular interactions, because no individual tag has provided the comprehensive breadth of utility. An ideal molecular tag is small and does not interrupt expression, solubility, folding or function of the protein being purified and can be used throughout the production process. We adapted and integrated a split-luciferase system (NanoBiT®, Promega ®) to perform the range of techniques essential to protein production. We developed a simple method to monitor protein expression in real time to optimize expression conditions. We constructed a novel affinity chromatography system using the split-luciferase system to enable purification. We adapted western blot analysis, enzyme-linked immunosorbent assay, and cell-based bioassay to characterize the expressed proteins. Our results demonstrate that a single-tag can fulfill all aspects needed throughout protein production.     

Estrogen inhibits osteoclasts formation and bone resorption via microRNA-27a targeting PPARγ and APC

Inhibition of osteoclasts formation and bone resorption by estrogen is very important in the etiology of postmenopausal osteoporosis. The mechanisms of this process are still not fully understood. Recent studies implicated an important role of microRNAs in estrogen-mediated responses in various cellular processes, including cell differentiation and proliferation. Thus, we hypothesized that these regulatory molecules might be implicated in the process of estrogen-decreased osteoclasts formation and bone resorption. Western blot, quantitative real-time polymerase chain reaction, tartrate-resistant acid phosphatase staining, pit formation assay and luciferase assay were used to investigate the role of microRNAs in estrogen-inhibited osteoclast differentiation and bone resorption. We found that estrogen could directly suppress receptor activator of nuclear factor B ligand/macrophage colony-stimulating factor-induced differentiation of bone marrow-derived macrophages into osteoclasts in the absence of stromal cell. MicroRNA-27a was significantly increased during the process of estrogen-decreased osteoclast differentiation. Overexpressing of microRNA-27a remarkably enhanced the inhibitory effect of estrogen on osteoclast differentiation and bone resorption, whereas which were alleviated by microRNA-27a depletion. Mechanistic studies showed that microRNA-27a inhibited peroxisome proliferator-activated receptor gamma (PPARγ) and adenomatous polyposis coli (APC) expression in osteoclasts through a microRNA-27a binding site within the 3′-untranslational region of PPARγ and APC. PPARγ and APC respectively contributed to microRNA-27a-decreased osteoclast differentiation and bone resorption. Taken together, these results showed that microRNA-27a may play a significant role in the process of estrogen-inhibited osteoclast differentiation and function.     

Effects of Melatonin on Growth,Physiology and Gene Expression in Rice Seedlings Under Cadmium Stress

Melatonin (MLT) is a hormonal substance found in many organisms and can improve plant stress resistance. In this study, the japonica rice variety Y32 and indica rice variety NJ6 were cultivated in hydroponics under different concentrations of CdCl₂ at the two-leaf stage. The growth, physiological and biochemical responses of the seedlings and the expression of cadmium (Cd)-related genes under exogenous melatonin (MLT) treatment were assessed. The results indicated that Cd stress destroyed the dynamic balance between reactive oxygen species (ROS) production and removal, resulting in ROS accumulation, membrane lipid peroxidation, and impaired growth and development. Following the application of exogenous MLT to rice seedlings, increases in plant biomass including both underground and above-ground areas were observed. MLT also scavenged the inhibition of superoxide dismutase (SOD) and peroxidase (POD) in a concentration dependent manner in response to Cd stress. Catalase (CAT) activity and malondialdehyde (MDA) expression also decreased following MLT treatment. Amongst the six Cd-related genes assessed, five genes were down-regulated and one was up-regulated in response to MLT treatment. Taken together, these data demonstrate that MLT improves the resilience of rice seedlings at the biochemical, physiological, and molecular levels, and diminishes the damage caused by Cd stress.     

Non-invasive estimation of root zone soil moisture from coarse root reflections in ground-penetrating radar images

Plant and Soil - Root zone soil moisture is an important component in water cycling through the soil-plant-atmosphere continuum. However, its measurement in the field remains a challenge,...     

Hydrogen-induced tolerance against osmotic stress in alfalfa seedlings involves ABA signaling

Plant and Soil - Cadmium (Cd) is a toxic metal in soils and its accumulation in plants poses severe problems to agricultural production and human health. Most of research has focused on the Cd...     

Ligularia dalaolingensis sp. nov. (Asteraceae–Senecioneae) from central China

Ligularia dalaolingensis, a new species from Hubei and Hunan, China, is described and illustrated. It belongs to L. sect. Ligularia ser. Speciosae on the basis of its palmate leaf venation, racemose synflorescence and pappus which is slightly shorter than the tube of the tubular corolla. In the series, its closest relatives are assumed to be L. fischeri and L. stenocephala. From L. fischeri, L. dalaolingensis is readily distinguished by smaller basal leaves, shorter synflorescence, narrower involucres and fewer phyllaries and florets; from L. stenocephala, L. dalaolingensis differs by smaller basal leaves, shorter synflorescence as well as broader bracts. A diagnostic key to Chinese species of L. ser. Speciosae with broadly ovate, ovate or ovate‐lanceolate bracts is provided.     

Spiradiclis densa sp. nov. (Rubiaceae) from limestone areas in Guangxi,China

A new species of Rubiaceae, Spiradiclis densa, is described and illustrated from southwestern China. It is similar to S. tomentosa, but differs in the elliptic or oblong leaf blades, distylous flowers and inner sides of corolla tube with dense pubescence near throat. The conservation status of the new species is preliminarily assessed as ‘Vulnerable’ according to IUCN categories and criteria.     

An Antagonism Joint Action of Lead and Di-2-Ethylhexyl Phthalate Explains an Improved Ability of Learning and Memory after Combined Exposure in Weaning Rats

Lead and di-2-ethylhexyl phthalate (DEHP) are widely distributed in the environment, and their neurotoxicity has caused a widespread concern. The complexity of environmental exposure provides the possibility of their combined exposure. The present study aims to describe a joint neurotoxicity and clarify the potential mechanism after combined exposure to lead and DEHP. A 2 × 3 factorial design was used to analyze either single effects or their interaction by a subchronic lead and DEHP exposure model of the male weaning rats. Similar to the previous study, lead or DEHP single exposure showed an increased neurotoxicity. Interestingly, our neurobehavioral test showed the rats in the combined exposure groups had a better ability of learning and memory compared with the single-exposure ones. It seemed to reflect an antagonism joint action in neurotoxicity after combined exposure. The content of dehydroepiandrosterone (DHEA) in serum and the mRNA level of brain-derived neurotrophic factor (Bdnf) in the hippocampus showed a similar trend to the ability of learning and memory. However, there was insufficient evidence to support the joint action on some indexes of oxidative stress such as malondialdehyde (MDA), the ratio of reduced glutathione(GSH) to oxidized glutathione(GSSG), γglutamylcysteine synthetase (γ-GCS), glutathione-s transferase (GST), and nuclear factor E2-related factor 2 (Nrf2) mRNA expression in the hippocampus. In a word, our current study reminded a unique antagonism joint action of neurotoxicity after combined exposure to lead and DEHP, which may contribute to understanding some shallow mechanism of the joint toxicity due to the complexity of environmental pollutant exposure.