129 research outputs found
Over-Expression of Leptin Receptors in Hypothalamic POMC Neurons Increases Susceptibility to Diet-Induced Obesity
Diet-induced obesity (DIO) in rodents is characterized by impaired activation of signal-transducer and activator of transcription 3 (STAT3) by leptin receptors (LepRb) within the hypothalamic arcuate nucleus. This signaling defect likely plays an important role in development of DIO. However, the neuro-chemical identity of the leptin-STAT3 resistant arcuate neurons has not been determined and the underlying mechanisms responsible for development of cellular leptin resistance remain unclear. To investigate this, we first measured arcuate gene expression of known key signaling components of the LepRb signaling pathway and tested whether specifically the critical arcuate pro-opiomelanocortin (POMC) neurons are resistant to LepRb-STAT3 signaling in mice given a high-fat-diet (HFD) compared to mice provided a low-fat control diet (LFD). We found that leptin-dependent STAT3 phosphorylation was decreased within POMC neurons of HFD mice. In addition, Leprb mRNA and suppressor of cytokine signaling 3 (Socs3) mRNA were elevated in the arcuate of HFD mice. To investigate whether increased LepRb expression per se in POMC neurons can influence development of DIO and Socs3 expression, we created mice that over-express LepRb selectively in POMC neurons (POMC-LepRb). No differences in body weight, fat mass or food intake were found between LFD POMC-LepRb mice and LFD controls. Surprisingly, body weight, fat mass and caloric intake of HFD POMC-LepRb mice was markedly higher than HFD control mice. In addition, arcuate Socs3 mRNA was increased in HFD POMC-LepRb mice compared to HFD controls. These data show that specifically POMC neurons of DIO mice are resistant to STAT3 activation by leptin, indicating that those cells might play a role in development of DIO. Furthermore, over-expression of LepRb selectively in POMC neurons increases susceptibility to the development of DIO. We propose a model where over-reactivity of the leptin-LepRb signaling system in arcuate neurons may play causal a role in development of diet-induced obesity
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Characterization of Defects in Ion Transport and Tissue Development in Cystic Fibrosis Transmembrane Conductance Regulator (CFTR)-Knockout Rats
Animal models for cystic fibrosis (CF) have contributed significantly to our understanding of disease pathogenesis. Here we describe development and characterization of the first cystic fibrosis rat, in which the cystic fibrosis transmembrane conductance regulator gene (CFTR) was knocked out using a pair of zinc finger endonucleases (ZFN). The disrupted Cftr gene carries a 16 base pair deletion in exon 3, resulting in loss of CFTR protein expression. Breeding of heterozygous (CFTR+/β) rats resulted in Mendelian distribution of wild-type, heterozygous, and homozygous (CFTRβ/β) pups. Nasal potential difference and transepithelial short circuit current measurements established a robust CF bioelectric phenotype, similar in many respects to that seen in CF patients. Young CFTRβ/β rats exhibited histological abnormalities in the ileum and increased intracellular mucus in the proximal nasal septa. By six weeks of age, CFTRβ/β males lacked the vas deferens bilaterally. Airway surface liquid and periciliary liquid depth were reduced, and submucosal gland size was abnormal in CFTRβ/β animals. Use of ZFN based gene disruption successfully generated a CF animal model that recapitulates many aspects of human disease, and may be useful for modeling other CF genotypes, including CFTR processing defects, premature truncation alleles, and channel gating abnormalities
Discovery of Diverse Small Molecule Chemotypes with Cell-Based PKD1 Inhibitory Activity
Protein kinase D (PKD) is a novel family of serine/threonine kinases regulated by diacylglycerol, which is involved in multiple cellular processes and various pathological conditions. The limited number of cell-active, selective inhibitors has historically restricted biochemical and pharmacological studies of PKD. We now markedly expand the PKD1 inhibitory chemotype inventory with eleven additional novel small molecule PKD1 inhibitors derived from our high throughput screening campaigns. The in vitro IC50s for these eleven compounds ranged in potency from 0.4 to 6.1 Β΅M with all of the evaluated compounds being competitive with ATP. Three of the inhibitors (CID 1893668, (1Z)-1-(3-ethyl-5-methoxy-1,3-benzothiazol-2-ylidene)propan-2-one; CID 2011756, 5-(3-chlorophenyl)-N-[4-(morpholin-4-ylmethyl)phenyl]furan-2-carboxamide; CID 5389142, (6Z)-6-[4-(3-aminopropylamino)-6-methyl-1H-pyrimidin-2-ylidene]cyclohexa-2,4-dien-1-one) inhibited phorbol ester-induced endogenous PKD1 activation in LNCaP prostate cancer cells in a concentration-dependent manner. The specificity of these compounds for PKD1 inhibitory activity was supported by kinase assay counter screens as well as by bioinformatics searches. Moreover, computational analyses of these novel cell-active PKD1 inhibitors indicated that they were structurally distinct from the previously described cell-active PKD1 inhibitors while computational docking of the new cell-active compounds in a highly conserved ATP-binding cleft suggests opportunities for structural modification. In summary, we have discovered novel PKD1 inhibitors with in vitro and cell-based inhibitory activity, thus successfully expanding the structural diversity of small molecule inhibitors available for this important pharmacological target
The Lantern, 2017-2018
On Dissociation β’ Untouchable β’ After Rocket Man β’ The Science Fair β’ Cardinal Rule at Stephen J. Memorial β’ Quentin & Sylvie β’ Cabello β’ The Get Out β’ Painting Day β’ Black, White and Grey β’ Family Pruning β’ How to Remove a Stain β’ Becoming Ourselves β’ Wonderbread U β’ Overture β’ Pescadero β’ Gross β’ Stage Fright β’ Lucky Daddy β’ Sarah β’ Rumble β’ Silvermine β’ The Green Iguana β’ A Poem for Ghost Children β’ A Poem for Lost Boys β’ Mother β’ Drop of Grease β’ Don\u27t Wanna be White β’ I β’ Amelia Earhart Disappeared Into My Vagina: An Ode to Cunts, Menstrual Cups and All Things Woman β’ Suburban Summer β’ Nightmares and Dreams Induced by My Mother β’ Teacups, Skins, etc. β’ Three Thoughts About My Bedroom β’ Dear Siri β’ 2 Queens (Beyonce in Reference to Sonia Sanchez) β’ Voyeurs β’ In Front of the Bathroom Mirror β’ To a Rose β’ Howl β’ Mice β’ Mirror β’ Language Accordion Volcano Mouth β’ Lucky Woman β’ Butterscotch β’ To Persephone β’ Wolf β’ Notes Never Passed β’ Topple β’ Bust β’ Kyoto β’ Identity β’ Sunflower β’ Tornabuoni Bubbles β’ Olympia β’ Decayed Hall β’ Perspectivehttps://digitalcommons.ursinus.edu/lantern/1186/thumbnail.jp
The Orexigenic Effect of Ghrelin Is Mediated through Central Activation of the Endogenous Cannabinoid System
INTRODUCTION
Ghrelin and cannabinoids stimulate appetite, this effect possibly being mediated by the activation of hypothalamic AMP-activated protein kinase (AMPK), a key enzyme in appetite and metabolism regulation. The cannabinoid receptor type 1 (CB1) antagonist rimonabant can block the orexigenic effect of ghrelin. In this study, we have elucidated the mechanism of the putative ghrelin-cannabinoid interaction.
METHODS
The effects of ghrelin and CB1 antagonist rimonabant in wild-type mice, and the effect of ghrelin in CB1-knockout animals, were studied on food intake, hypothalamic AMPK activity and endogenous cannabinoid content. In patch-clamp electrophysiology experiments the effect of ghrelin was assessed on the synaptic inputs in parvocellular neurons of the hypothalamic paraventricular nucleus, with or without the pre-administration of a CB1 antagonist or of cannabinoid synthesis inhibitors.
RESULTS AND CONCLUSIONS
Ghrelin did not induce an orexigenic effect in CB1-knockout mice. Correspondingly, both the genetic lack of CB1 and the pharmacological blockade of CB1 inhibited the effect of ghrelin on AMPK activity. Ghrelin increased the endocannabinoid content of the hypothalamus in wild-type mice and this effect was abolished by rimonabant pre-treatment, while no effect was observed in CB1-KO animals. Electrophysiology studies showed that ghrelin can inhibit the excitatory inputs on the parvocellular neurons of the paraventricular nucleus, and that this effect is abolished by administration of a CB1 antagonist or an inhibitor of the DAG lipase, the enzyme responsible for 2-AG synthesis. The effect is also lost in the presence of BAPTA, an intracellular calcium chelator, which inhibits endocannabinoid synthesis in the recorded parvocellular neuron and therefore blocks the retrograde signaling exerted by endocannabinoids. In summary, an intact cannabinoid signaling pathway is necessary for the stimulatory effects of ghrelin on AMPK activity and food intake, and for the inhibitory effect of ghrelin on paraventricular neurons
The Lantern, 2015-2016
β’ Ghosts β’ Going to China β’ 98% Guaranteed β’ Constellation/Boulevard β’ Prayer β’ The Little One β’ Burning β’ The Amber Macaroon β’ Becoming β’ Requiem β’ Construction Site β’ Thirteen Ways of Looking at a Dragon β’ Charlie β’ No Sleep β’ A Lesson in Physical Education β’ Statues β’ Who Can Love a Black Woman? β’ Apples β’ Fun Craft β’ The Door at Midnight β’ Eve as a Book in the Bible β’ Boys β’ Diamond Heart β’ To Apollo β’ Joanne and Her July Garden β’ Option A, 1936 β’ Young White Girls, Hollow Bodies, and Home β’ Mama\u27s Stance on Sugar β’ The Mariana Trench β’ Hurricane β’ Part of the Job β’ Avenue H Blues β’ Hour of Nones β’ Send Toilet Paper β’ Grave Robbing β’ Wild Turkey β’ The Creek β’ Let\u27s Go for a Walk β’ Deaconess β’ Border of Love β’ Your Father, Rumpelstiltskin β’ Purchasing Poplars β’ Red Tatters β’ Sunken β’ Whispers β’ Existence β’ God Took a Cigarette Break with Police Officers β’ Martian Standoff β’ In the Headlights β’ It\u27s a Subtle Thing β’ Dear Kent β’ Hanako-san β’ A Brief Interlude β’ On Fencing, Gummy Worms, and my Inescapable Fear of Living in the Moment β’ Stolen Soul β’ Block β’ Mortem Mei Fratris β’ Kalki β’ Lake Placid β’ Atom and Eve β’ The Baerie Queene β’ Gladston β’ Soldiers at Gettysburg β’ Pattern β’ Foliage β’ Mass Media β’ Arrow β’ Move Out β’ Wanderers β’ Riverside Gardenhttps://digitalcommons.ursinus.edu/lantern/1182/thumbnail.jp
Alterations to Melanocortinergic, GABAergic and Cannabinoid Neurotransmission Associated with Olanzapine-Induced Weight Gain
Background/Aim: Second generation antipsychotics (SGAs) are used to treat schizophrenia but can cause serious metabolic side-effects, such as obesity and diabetes. This study examined the effects of low to high doses of olanzapine on appetite/ metabolic regulatory signals in the hypothalamus and brainstem to elucidate the mechanisms underlying olanzapineinduced obesity. Methodology/Results: Levels of pro-opiomelanocortin (POMC), neuropeptide Y (NPY) and glutamic acid decarboxylase (GAD65, enzyme for GABA synthesis) mRNA expression, and cannabinoid CB1 receptor (CB1R) binding density (using [ 3 H]SR-141716A) were examined in the arcuate nucleus (Arc) and dorsal vagal complex (DVC) of female Sprague Dawley rats following 0.25, 0.5, 1.0 or 2.0 mg/kg olanzapine or vehicle (36/day, 14-days). Consistent with its weight gain liability, olanzapine significantly decreased anorexigenic POMC and increased orexigenic NPY mRNA expression in a dose-sensitive manner in the Arc. GAD65 mRNA expression increased and CB1R binding density decreased in the Arc and DVC. Alterations to neurotransmission signals in the brain significantly correlated with body weight and adiposity. The minimum dosage threshold required to induce weight gain in the rat was 0.5 mg/kg olanzapine. Conclusions: Olanzapine-induced weight gain is associated with reduced appetite-inhibiting POMC and increased NPY. This study also supports a role for the CB1R and GABA in the mechanisms underlying weight gain side-effects, possibly b
Effectiveness of manual therapies: the UK evidence report
<p>Abstract</p> <p>Background</p> <p>The purpose of this report is to provide a succinct but comprehensive summary of the scientific evidence regarding the effectiveness of manual treatment for the management of a variety of musculoskeletal and non-musculoskeletal conditions.</p> <p>Methods</p> <p>The conclusions are based on the results of systematic reviews of randomized clinical trials (RCTs), widely accepted and primarily UK and United States evidence-based clinical guidelines, plus the results of all RCTs not yet included in the first three categories. The strength/quality of the evidence regarding effectiveness was based on an adapted version of the grading system developed by the US Preventive Services Task Force and a study risk of bias assessment tool for the recent RCTs.</p> <p>Results</p> <p>By September 2009, 26 categories of conditions were located containing RCT evidence for the use of manual therapy: 13 musculoskeletal conditions, four types of chronic headache and nine non-musculoskeletal conditions. We identified 49 recent relevant systematic reviews and 16 evidence-based clinical guidelines plus an additional 46 RCTs not yet included in systematic reviews and guidelines.</p> <p>Additionally, brief references are made to other effective non-pharmacological, non-invasive physical treatments.</p> <p>Conclusions</p> <p>Spinal manipulation/mobilization is effective in adults for: acute, subacute, and chronic low back pain; migraine and cervicogenic headache; cervicogenic dizziness; manipulation/mobilization is effective for several extremity joint conditions; and thoracic manipulation/mobilization is effective for acute/subacute neck pain. The evidence is inconclusive for cervical manipulation/mobilization alone for neck pain of any duration, and for manipulation/mobilization for mid back pain, sciatica, tension-type headache, coccydynia, temporomandibular joint disorders, fibromyalgia, premenstrual syndrome, and pneumonia in older adults. Spinal manipulation is not effective for asthma and dysmenorrhea when compared to sham manipulation, or for Stage 1 hypertension when added to an antihypertensive diet. In children, the evidence is inconclusive regarding the effectiveness for otitis media and enuresis, and it is not effective for infantile colic and asthma when compared to sham manipulation.</p> <p>Massage is effective in adults for chronic low back pain and chronic neck pain. The evidence is inconclusive for knee osteoarthritis, fibromyalgia, myofascial pain syndrome, migraine headache, and premenstrual syndrome. In children, the evidence is inconclusive for asthma and infantile colic.</p
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