Proteomic Analysis of Rat Hypothalamus Revealed the Role of Ubiquitin–Proteasome System in the Genesis of DR or DIO

Obesity has become a global epidemic, contributing to the increasing burdens of cardiovascular disease and type 2 diabetes. However, the precise molecular mechanisms of obesity remain poorly elucidated. The hypothalamus plays a major part in regulating energy homeostasis by integrating all kinds of nutritional signals. This study investigated the hypothalamus protein profile in diet-induced obese (DIO) and diet-resistant (DR) rats using two dimensional gel electrophoresis (2-DE) combined with MALDI-TOF/TOF–MS analysis. Twenty-two proteins were identified in the hypothalamus of DIO or DR rats. These include metabolic enzymes, antioxidant proteins, proteasome related proteins, and signaling proteins, some of which are related to AMP-activated protein kinase (AMPK) signaling or mitochondrial respiration. Among these proteins, in comparison with the normal-diet group, Ubiquitin was significantly decreased in DR rats but not changed in DIO rats, while Ubiquitin carboxyl-terminal esterase L1 (UCHL-1) was decreased in DIO rats but not changed in DR rats. The expression level of Ubiquitin and UCHL-1 were further validated using Western blot analysis. Our study reveals that Ubiquitin and UCHL-1 are obesity-related factors in the hypothalamus that may play an important role in the genesis of DR or DIO by interfering with the integrated signaling network that control energy balance and feeding

Up-regulation of the expression of cocaine and amphetamine-regulated transcript peptide by electroacupuncture in the arcuate nucleus of diet-induced obese rats

Abstract It was reported that acupuncture or electro-acupuncture (EA) is effective in reducing the body weight for obese patients, although the mechanisms remain obscure. In a previous study, we have found that rats fed with high-fat (HIF) diet developed diet-induced obesity (DIO) with a concomitant decrease in the hypothalamic content of the cocaine and amphetamine-regulated transcript (CART) peptide, a peptide with anorexiogenic effect. To assess the central effect of EA on DIO rat, we revealed that EA up-regulated the expression of CART peptide in the arcuate nucleus (ARC) of the DIO rats. After feeding with HIF diet for 14 weeks, the DIO rats received EA stimulation three times per week for 4 weeks. The expression of CART peptide in ARC was measured using immunohistochemistry. The plasma ACTH was measured with ELISA. EA caused a reduction of both body weight and energy intake in DIO rats and increased the expression of CART peptide in ARC. The plasma ACTH was increased in response to restraint stress, but EA produced no further increase in ACTH levels. The results suggest that EA can up-regulate the expression of CART peptide to approach normal level, resulting in an inhibition of food intake and a reduction of body weight in DIO rats. © 2005 Elsevier Ireland Ltd. All rights reserved. Keywords: Electroacupuncture; CART; Body weight; Diet-induced obesity; Arcuate nucleus In humans and animals, a chronic high-fat (HIF) diet without a compensatory increase in energy expenditure leads to the progressive development of obesity E-mail addresses: [email protected], [email protected] (J.-S. Han). 1 Present address: Department of Surgery, Tianjin No. 3 Central Hospital, Tianjin 300170, China. tiveness of acupuncture, and even today, it is not generally regarded as scientifically acceptable. The problem has always been the difficulty to explain the mechanisms behind the effects of acupuncture, and to demonstrate its effects in controlled clinical trials As in much of human obese cases, the rat model of dietinduced obesity (DIO) appears to follow a polygenic mode in inheritance. Hypothalamic neuropeptides play an important role in regulating energy balanc

Propofol Directly Increases Tau Phosphorylation

In Alzheimer's disease (AD) and other tauopathies, the microtubule-associated protein tau can undergo aberrant hyperphosphorylation potentially leading to the development of neurofibrillary pathology. Anesthetics have been previously shown to induce tau hyperphosphorylation through a mechanism involving hypothermia-induced inhibition of protein phosphatase 2A (PP2A) activity. However, the effects of propofol, a common clinically used intravenous anesthetic, on tau phosphorylation under normothermic conditions are unknown. We investigated the effects of a general anesthetic dose of propofol on levels of phosphorylated tau in the mouse hippocampus and cortex under normothermic conditions. Thirty min following the administration of propofol 250 mg/kg i.p., significant increases in tau phosphorylation were observed at the AT8, CP13, and PHF-1 phosphoepitopes in the hippocampus, as well as at AT8, PHF-1, MC6, pS262, and pS422 epitopes in the cortex. However, we did not detect somatodendritic relocalization of tau. In both brain regions, tau hyperphosphorylation persisted at the AT8 epitope 2 h following propofol, although the sedative effects of the drug were no longer evident at this time point. By 6 h following propofol, levels of phosphorylated tau at AT8 returned to control levels. An initial decrease in the activity and expression of PP2A were observed, suggesting that PP2A inhibition is at least partly responsible for the hyperphosphorylation of tau at multiple sites following 30 min of propofol exposure. We also examined tau phosphorylation in SH-SY5Y cells transfected to overexpress human tau. A 1 h exposure to a clinically relevant concentration of propofol in vitro was also associated with tau hyperphosphorylation. These findings suggest that propofol increases tau phosphorylation both in vivo and in vitro under normothermic conditions, and further studies are warranted to determine the impact of this anesthetic on the acceleration of neurofibrillary pathology

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Lumbar Intradural Disc Herniation Caused by Injury: A Case Report and Literature Review

Background Intradural disc herniation(IDH) caused by trauma is a rare type of disease，which is difficult to diagnose clinically and is easily misdiagnosed. We received a patient with the disease, reported the case to share the process of diagnosis and treatment and put forward our own opinions, so as to increase the probability of correct diagnosis. Case Presentation We report the case of a 48‐year‐old male who fell from a scaffold at a height of 2 m. Later, he developed low back pain, restricted movement, numbness and hyperalgesia of the lower left limb, and decreased left muscle strength. He was diagnosed with IDH. Treatment with posterior decompression and intramedullary decompression with pedicle screw internal fixation was performed. His postoperative course was uneventful, and he underwent regular follow up for 1 year. Good neurologic symptom improvement was achieved. Conclusions IDH is rare, and comprehensive consideration and film reading can improve the correct diagnosis rate. Accurate diagnosis and early decompression of laminae and intramedullary decompression can lead to good recovery after neurologic impingement

Theoretical Study of Quantum Conductance of Conjugated and Nonconjugated Molecular Wire Junctions

Electron transport through molecular junctions has been widely investigated experimentally and theoretically. Unfortunately, there exists discrepancy on the single molecular conductance between theoretical calculations and experimental measurements. In this paper, first-principle density functional theory combined with nonequilibrium Green’s function approach is employed; we studied electronic structures, molecular lengths, and interfacial interactions of three kinds of molecular junctions, alkanedithiols, oligo­(1,4-phenylene-ethynylene)­s, and 1,4-benzene-di­(<i>n</i>-alkylthiol) (BD<i>n</i>T), embedding in nanogaps of gold electrodes. First, our approach can accurately describe the binding interaction between the thiol group and gold electrode so that the conductance of alkanedithiol in a gold junction can be well predicted. We found that a previous underestimation of HOMO–LUMO gaps in the junction system leads to the overestimated conductance for conjugate molecules with sulfur atoms binding to gold electrodes. In the study of BD<i>n</i>T molecular wires with a phenyl ring, our results show that the HOMO–LUMO gap reaches a constant with molecular length increasing. Moreover, a larger predicted conductance can be attributed to the overlapping between the nonbonding lone-paired orbital of sulfur atoms and the delocalized π electrons of the phenyl ring. Finally, we found that the conductance of molecules with short length or conjugated electronic structure greatly relies on the interfacial configuration. We proposed that these findings can give a clear understanding of electron transport in junction systems and open a promising theoretical study of molecular electronics