Characterization of a novel peripheral pro-lipolytic mechanism in mice: role of VGF-derived peptide TLQP-21

2011 ◽  
Vol 441 (1) ◽  
pp. 511-522 ◽  
Author(s):  
Roberta Possenti ◽  
Giampiero Muccioli ◽  
Pamela Petrocchi ◽  
Cheryl Cero ◽  
Aderville Cabassi ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Ex Vivo ◽  
Binding Capacity ◽  
Binding Activity ◽  
Metabolic Complications ◽  
Novel Approach ◽  
Receptor Binding Activity ◽  
Treatment Of Obesity

The peptides encoded by the VGF gene are gaining biomedical interest and are increasingly being scrutinized as biomarkers for human disease. An endocrine/neuromodulatory role for VGF peptides has been suggested but never demonstrated. Furthermore, no study has demonstrated so far the existence of a receptor-mediated mechanism for any VGF peptide. In the present study, we provide a comprehensive in vitro, ex vivo and in vivo identification of a novel pro-lipolytic pathway mediated by the TLQP-21 peptide. We show for the first time that VGF-immunoreactivity is present within sympathetic fibres in the WAT (white adipose tissue) but not in the adipocytes. Furthermore, we identified a saturable receptor-binding activity for the TLQP-21 peptide. The maximum binding capacity for TLQP-21 was higher in the WAT as compared with other tissues, and selectively up-regulated in the adipose tissue of obese mice. TLQP-21 increases lipolysis in murine adipocytes via a mechanism encompassing the activation of noradrenaline/β-adrenergic receptors pathways and dose-dependently decreases adipocytes diameters in two models of obesity. In conclusion, we demonstrated a novel and previously uncharacterized peripheral lipolytic pathway encompassing the VGF peptide TLQP-21. Targeting the sympathetic nerve–adipocytes interaction might prove to be a novel approach for the treatment of obesity-associated metabolic complications.

scholarly journals Allergenic Characterization of New Mutant Forms of Pru p 3 as New Immunotherapy Vaccines

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
C. Gómez-Casado ◽  
M. Garrido-Arandia ◽  
P. Gamboa ◽  
N. Blanca-López ◽  
G. Canto ◽  
...  
Keyword(s):  
Food Allergy ◽  
Ex Vivo ◽  
Binding Capacity ◽  
Cross Reactivity ◽  
T Cell Epitopes ◽  
Native Form ◽  
Ige Binding ◽  
Pru P 3

Nowadays, treatment of food allergy only considered the avoidance of the specific food. However, the possibility of cross-reactivity makes this practice not very effective. Immunotherapy may exhibit as a good alternative to food allergy treatment. The use of hypoallergenic molecules with reduced IgE binding capacity but with ability to stimulate the immune system is a promising tool which could be developed for immunotherapy. In this study, three mutants of Pru p 3, the principal allergen of peach, were produced based on the described mimotope and T cell epitopes, by changing the specific residues to alanine, named asPru p 3.01, Pru p 3.02, andPru p 3.03.Pru p 3.01showed very similar allergenic activity as the wild type byin vitroassays. However,Pru p 3.02andPru p 3.03presented reduced IgE binding with respect to the native form, byin vitro,ex vivo,and in vivo assays. In addition,Pru p 3.03had affected the IgG4 binding capacity and presented a random circular dichroism, which was reflected in the nonrecognition by specific antibodies anti-Pru p 3. Nevertheless, bothPru p 3.02andPru p 3.03maintained the binding to IgG1 and their ability to activate T lymphocytes. Thus,Pru p 3.02andPru p 3.03could be good candidates for potential immunotherapy in peach-allergic patients.

scholarly journals Dopamine receptor D1- and D2-agonists do not spark brown adipose tissue thermogenesis in mice

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Francesca-Maria Raffaelli ◽  
Julia Resch ◽  
Rebecca Oelkrug ◽  
K. Alexander Iwen ◽  
Jens Mittag
Keyword(s):  
Adipose Tissue ◽  
Brown Adipose Tissue ◽  
Dopamine Receptor ◽  
Ex Vivo ◽  
Potential Target ◽  
D2 Agonist ◽  
Obesity And Diabetes ◽  
Brown Adipose

AbstractBrown adipose tissue (BAT) thermogenesis is considered a potential target for treatment of obesity and diabetes. In vitro data suggest dopamine receptor signaling as a promising approach; however, the biological relevance of dopamine receptors in the direct activation of BAT thermogenesis in vivo remains unclear. We investigated BAT thermogenesis in vivo in mice using peripheral administration of D1-agonist SKF38393 or D2-agonist Sumanirole, infrared thermography, and in-depth molecular analyses of potential target tissues; and ex vivo in BAT explants to identify direct effects on key thermogenic markers. Acute in vivo treatment with the D1- or D2-agonist caused a short spike or brief decrease in BAT temperature, respectively. However, repeated daily administration did not induce lasting effects on BAT thermogenesis. Likewise, neither agonist directly affected Ucp1 or Dio2 mRNA expression in BAT explants. Taken together, the investigated agonists do not seem to exert lasting and physiologically relevant effects on BAT thermogenesis after peripheral administration, demonstrating that D1- and D2-receptors in iBAT are unlikely to constitute targets for obesity treatment via BAT activation.

Increased in vitro fatty acid supply and cellular transport capacities in cold-acclimated ducklings (Cairina moschata)

1998 ◽  
Vol 275 (3) ◽  
pp. R683-R690 ◽  
Author(s):  
Christophe Bénistant ◽  
Claude Duchamp ◽  
Frédérique Cohen-Adad ◽  
Jean-Louis Rouanet ◽  
Hervé Barré
Keyword(s):  
Adipose Tissue ◽  
Gastrocnemius Muscle ◽  
Lipolytic Activity ◽  
Binding Capacity ◽  
Cellular Transport ◽  
Transport Capacity ◽  
Nonesterified Fatty Acids ◽  
Cairina Moschata

In cold-acclimated (CA) birds, lipids play a crucial role in regulatory thermogenesis by acting both as substrates for and activators of thermogenic processes. The capacity to supply lipids to thermogenic tissues, which could limit cold thermogenesis, was assessed in CA ducklings (5 wk old, 4°C) and compared with thermoneutral controls (TN, 25°C). In CA ducklings, basal lipolytic activity of adipose tissue fragments was higher (202 ± 9 vs. 130 ± 14 nmol glycerol released ⋅ 100 mg tissue−1 ⋅ h−1, +55%) than in TN controls, while glucagon had a much higher stimulatory effect (+140 to +500% depending on dose). This was consistent with increased plasma levels of nonesterified fatty acids (FA, +57%) and glycerol (+31%) in vivo. In vitro endothelial lipase activity per organ was higher in CA than in TN ducklings in red gastrocnemius muscle (6.3 ± 0.6 vs. 3.5 ± 0.3 μeq nonesterified FA released per hour, +80%) and liver (+55%). The intracellular FA-binding capacity of (12–18 kDa) proteins was higher in gastrocnemius muscle (+43%) and liver (+74%) from CA ducklings. In gastrocnemius, it was linked to a higher content (21 ± 2 vs. 15 ± 2 μg/mg protein, +37%) of an intracellular 15.4-kDa FA-binding protein. These in vitro results indicate that coordinated increases in FA supply from adipose tissue, cellular uptake of lipoprotein-derived FA, and intracellular FA transport capacity occur in CA ducklings endowed with higher thermogenic capacity and cold endurance.

scholarly journals Myostatin Attenuation In Vivo Reduces Adiposity, but Activates Adipogenesis

Endocrinology ◽  
2016 ◽  
Vol 157 (1) ◽  
pp. 282-291 ◽  
Author(s):  
Naisi Li ◽  
Qiyuan Yang ◽  
Ryan G. Walker ◽  
Thomas B. Thompson ◽  
Min Du ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Muscle Mass ◽  
Wild Type ◽  
Cell Counts ◽  
Novel Approach ◽  
Brown Adipose ◽  
Nutrient Partitioning ◽  
Differentiation Marker

Abstract A potentially novel approach for treating obesity includes attenuating myostatin as this increases muscle mass and decreases fat mass. Notwithstanding, conflicting studies report that myostatin stimulates or inhibits adipogenesis and it is unknown whether reduced adiposity with myostatin attenuation results from changes in fat deposition or adipogenesis. We therefore quantified changes in the stem, transit amplifying and progenitor cell pool in white adipose tissue (WAT) and brown adipose tissue (BAT) using label-retaining wild-type and mstn−/− (Jekyll) mice. Muscle mass was larger in Jekyll mice, WAT and BAT mass was smaller and label induction was equal in all tissues from both wild-type and Jekyll mice. The number of label-retaining cells, however, dissipated quicker in WAT and BAT of Jekyll mice and was only 25% and 17%, respectively, of wild-type cell counts 1 month after induction. Adipose cell density was significantly higher in Jekyll mice and increased over time concomitant with label-retaining cell disappearance, which is consistent with enhanced expansion and differentiation of the stem, transit amplifying and progenitor pool. Stromal vascular cells from Jekyll WAT and BAT differentiated into mature adipocytes at a faster rate than wild-type cells and although Jekyll WAT cells also proliferated quicker in vitro, those from BAT did not. Differentiation marker expression in vitro, however, suggests that mstn−/− BAT preadipocytes are far more sensitive to the suppressive effects of myostatin. These results suggest that myostatin attenuation stimulates adipogenesis in vivo and that the reduced adiposity in mstn−/− animals results from nutrient partitioning away from fat and in support of muscle.

scholarly journals A comparison of HER2 tumor accumulations of Ga-67 labeled anti-HER2 antibody with chemically and site-specifically conjugated bifunctional chelators

2020 ◽  
Author(s):  
Yumiko Kono ◽  
Keita Utsunomiya ◽  
Yuta Ohira ◽  
Hirokazu Satoh ◽  
Naoki Kan ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Binding Capacity ◽  
Binding Activity ◽  
Pharmacokinetic Analysis ◽  
Pharmacokinetic Studies ◽  
Her2 Positive ◽  
Site Specific ◽  
Planar Images

Abstract Background Monoclonal antibodies (mAb) developed to target specific cancers have achieved considerable success to-date. To further enhance therapeutic efficacy monoclonal antibodies may be conjugated with a cytotoxic drug or radioisotope. We present the development of new method based on site-specific conjugation (SSC) for targeting HER2. The study design involves a comparison of the accumulation of Ga-67 labeled anti-HER2 antibodies with SSC versus conventional chemical conjugation in HER2-positive tumors. Anti-HER2 antibodies were chemically conjugated (Chem) with the bifunctional chelator deferoxamine (Chem-mAb). The resulting chemical conjugate was radiolabeled with Ga-67 yielding Ga-67-Chem -mAb. The SSC anti-HER2 antibodies enzymatically conjugated with deferoxamine using transglutaminase (SSC-mAb) and radiolabeled with Ga-67 yielding Ga-67-SSC-mAb. In vitro, the binding activity of HER2 to both conjugated antibodies was measured using surface Plasmon resonance. In vivo, a xenograft mouse model consisting of transplanted CHO/HER2 were divided into two groups, the Chem and the SSC group. Planar images were acquired over three days after each mAb injection, respectively. Pharmacokinetic analysis was used to compare the Chem group to the SSC group, for Ga-67 accumulation. Result The SSC and Chem groups were found to have similar HER2 binding capacity, however the tumor accumulation ratio gradually increased in the SSC group. The pharmacokinetic studies also found that radiolabeled mAb accumulation was significantly higher in the SSC group than the Chem group in not only the tumors, but also in blood and in other organs. Conclusion The new site-specific conjugation may improve targeted antigen-specific cancer radioimmunotherapy and may, due to higher retention, require a lower dose.

scholarly journals Transcription Factor E2F1 Knockout Promotes Mice White Adipose Tissue Browning Through Autophagy Inhibition

2021 ◽  
Vol 12 ◽  
Author(s):  
Mingchen Xiong ◽  
Weijie Hu ◽  
Yufang Tan ◽  
Honghao Yu ◽  
Qi Zhang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Uncoupling Protein ◽  
Underlying Mechanism ◽  
Metabolic Complications ◽  
Autophagy Inhibition ◽  
Transcription Factor E2f1

Obesity is associated with energy metabolic disturbance and is caused by long-term excessive energy storage in white adipose tissue (WAT). The WAT browning potentially reduces excessive energy accumulation, contributing an attractive target to combat obesity. As a pivotal regulator of cell growth, the transcription factor E2F1 activity dysregulation leads to metabolic complications. The regulatory effect and underlying mechanism of E2F1 knockout on WAT browning, have not been fully elucidated. To address this issue, in this study, the in vivo adipose morphology, mitochondria quantities, uncoupling protein 1 (UCP-1), autophagy-related genes in WAT of wild-type (WT) and E2F1–/– mice were detected. Furthermore, we evaluated the UCP-1, and autophagy-related gene expression in WT and E2F1–/– adipocyte in vitro. The results demonstrated that E2F1 knockout could increase mitochondria and UCP-1 expression in WAT through autophagy suppression in mice, thus promoting WAT browning. Besides, adipocytes lacking E2F1 showed upregulated UCP-1 and downregulated autophagy-related genes expression in vitro. These results verified that E2F1 knockout exerted effects on inducing mice WAT browning through autophagy inhibition in vivo and in vitro. These findings regarding the molecular mechanism of E2F1-modulated autophagy in controlling WAT plasticity, provide a novel insight into the functional network with the potential therapeutic application against obesity.

scholarly journals Natural Histogel-Based Bio-Scaffolds for Sustaining Angiogenesis in Beige Adipose Tissue

Cells ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1457 ◽  
Author(s):  
Margherita Di Somma ◽  
Wandert Schaafsma ◽  
Elisabetta Grillo ◽  
Maria Vliora ◽  
Eleni Dakou ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Three Dimensional ◽  
Chorioallantoic Membrane ◽  
Mesenchymal Cells ◽  
Endothelial Cell Proliferation ◽  
Differentiated Cells ◽  
Brown Adipose ◽  
Treatment Of Obesity

In the treatment of obesity and its related disorders, one of the measures adopted is weight reduction by controlling nutrition and increasing physical activity. A valid alternative to restore the physiological function of the human body could be the increase of energy consumption by inducing the browning of adipose tissue. To this purpose, we tested the ability of Histogel, a natural mixture of glycosaminoglycans isolated from animal Wharton jelly, to sustain the differentiation of adipose derived mesenchymal cells (ADSCs) into brown-like cells expressing UCP-1. Differentiated cells show a higher energy metabolism compared to undifferentiated mesenchymal cells. Furthermore, Histogel acts as a pro-angiogenic matrix, induces endothelial cell proliferation and sprouting in a three-dimensional gel in vitro, and stimulates neovascularization when applied in vivo on top of the chicken embryo chorioallantoic membrane or injected subcutaneously in mice. In addition to the pro-angiogenic activity of Histogel, also the ADSC derived beige cells contribute to activating endothelial cells. These data led us to propose Histogel as a promising scaffold for the modulation of the thermogenic behavior of adipose tissue. Indeed, Histogel simultaneously supports the acquisition of brown tissue markers and activates the vasculature process necessary for the correct function of the thermogenic tissue. Thus, Histogel represents a valid candidate for the development of bioscaffolds to increase the amount of brown adipose tissue in patients with metabolic disorders.

scholarly journals Regulation by glucocorticoids of angiotensinogen gene expression and secretion in adipose cells

1997 ◽  
Vol 328 (2) ◽  
pp. 701-706 ◽  
Author(s):  
Jérôme AUBERT ◽  
Christian DARIMONT ◽  
Irina SAFONOVA ◽  
Gérard AILHAUD ◽  
Raymond NEGREL
Keyword(s):  
Gene Expression ◽  
Adipose Tissue ◽  
Transcriptional Activation ◽  
Ex Vivo ◽  
Activation Product ◽  
Potential Link ◽  
Rat Adipose Tissue ◽  
Adipose Cells

Adipose cells are an important source of angiotensinogen (AT). Its activation product, angiotensin II, stimulates in vitro and in vivo the production and release of prostacyclin which acts as a potent adipogenic signal in promoting the terminal differentiation of preadipocytes to adipocytes. Since glucocorticoids are known to promote adipose cell differentiation in vitro as well as in vivo, their role in the regulation of AT gene expression and secretion has been investigated in cultured Ob1771 mouse adipose cells. In contrast with liver cells, which are the major source of AT and the target of several hormones for the regulation of its expression, adipose cells are only responsive to glucocorticoids, which are able to up-regulate AT gene expression and AT secretion rapidly and dose-dependently. On exposure to glucocorticoids, accumulation of AT mRNA appears primarily to be due to transcriptional activation of the gene and is parallelled by secretion of the protein. Similar results on AT mRNA expression and AT secretion were obtained using explants of rat adipose tissue ex vivo demonstrating a major if not exclusive mechanism of regulation of AT production by glucocorticoids in mature adipose cells. Together these results provide a potential link between glucocorticoids, AT, the growth of adipose tissue and increased blood pressure.

scholarly journals Discovery of tumoricidal DNA oligonucleotides by effect-directedin-vitroevolution

2019 ◽  
Author(s):  
Noam Mamet ◽  
Yaniv Amir ◽  
Erez Lavi ◽  
Liron Bassali ◽  
Gil Harari ◽  
...  
Keyword(s):  
Drug Discovery ◽  
De Novo ◽  
Ex Vivo ◽  
Binding Capacity ◽  
Biological Effects ◽  
Current Model ◽  
Target Cells ◽  
Dna Oligonucleotides

AbstractOur current model of drug discovery is challenged by the relative ineffectiveness of drugs against highly variable and rapidly evolving diseases and their relatively high incidence of adverse effects due to poor selectivity. Here we describe a robust and reproducible platform which could potentially address these limitations. The platform enables rapid,de-novodiscovery of DNA oligonucleotides evolvedin-vitroto exert specific biological effects on target cells. Unlike aptamers, which are selected by their ligand binding capacity, this platform is driven directly by therapeutic effect and selectivity towards target vs negative target cells. The process could, therefore, operate without anya-prioriknowledge (e.g. mutations, biomarker expression, or known drug resistance) of the target. We report the discovery of DNA oligonucleotides with direct and selective cytotoxicity towards several tumor cell lines as well as primary, patient-derived solid and hematological tumors, some with chemotherapy resistance. Oligonucleotides discovered by this platform exhibited favorable biodistribution in animals, persistence in target tumors up to 48 hours after injection, and safety in human blood. These oligonucleotides showed remarkable efficacyin-vivoas well asex-vivoin freshly obtained, 3D cultured human tumors resistant to multiple chemotherapies. With further improvement, these findings could lead to a drug discovery model which is target-tailored, mechanism-flexible, and nearly on-demand.

scholarly journals Adipocyte hypertrophy is associated with lysosomal permeability both in vivo and in vitro: role in adipose tissue inflammation

2012 ◽  
Vol 303 (5) ◽  
pp. E597-E606 ◽  
Author(s):  
Agnieszka Gornicka ◽  
Jade Fettig ◽  
Akiko Eguchi ◽  
Michael P. Berk ◽  
Samjhana Thapaliya ◽  
...  
Keyword(s):  
Cell Death ◽  
Adipose Tissue ◽  
Saturated Fatty Acids ◽  
Macrophage Infiltration ◽  
Early Event ◽  
Metabolic Complications ◽  
Adipocyte Cell ◽  
Adipocyte Hypertrophy

Obesity in both humans and rodents is characterized by adipocyte hypertrophy and the presence of death adipocytes surrounded by macrophages forming “crown-like structures.” However, the biochemical pathways involved in triggering adipocyte death as well as the role of death adipocytes in adipose tissue remodeling and macrophage infiltration remain poorly understood. We now show that induction of adipocyte hypertrophy by incubation of mature adipocytes with saturated fatty acids results in lysosomal destabilization and cathepsin B (ctsb), a key lysosomal cysteine protease, activation and redistribution into the cytosol. ctsb activation was required for the lysosomal permeabilization, and its inhibition protected cells against mitochondrial dysfunction. With the use of a dietary murine model of obesity, ctsb activation was detected in adipose tissue of these mice. This is an early event during weight gain that correlates with the presence of death adipocytes, and precedes macrophage infiltration of adipose tissue. Moreover, ctsb-deficient mice showed decreased lysosomal permeabilization in adipocytes and were protected against adipocyte cell death and macrophage infiltration to adipose tissue independent of body weight. These data strongly suggest that ctsb activation and lysosomal permeabilization in adipocytes are key initial events that contribute to the adipocyte cell death and macrophage infiltration into adipose tissue associated with obesity. Inhibition of ctsb activation may be a new therapeutic strategy for the treatment of obesity-associated metabolic complications.

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