In today's rapidly changing business landscape, entrepreneurship is growing and actively promoted by policy makers. Several reports explore the influence of entrepreneurship on the economy and put ...some emphasis on its positive influence GDP per capita, unemployment and exports. However, entrepreneurship does not go per se and it is now broadly admitted that the decision of the entrepreneur is narrowly connected with its environment, the so-called entrepreneurial ecosystem. This book show why policymakers, entrepreneurship supporters, and entrepreneurs themselves should keep in mind the locally structured nature of entrepreneurial networks. Even if the notion of Entrepreneurial Ecosystem has become quite popular, among the international organization, development agencies and public administrations, this concept is often considered as a new one having its origins in very recent publications. This books aims at showing that entrepreneurial ecosystems have their roots in the history of economic thought and that scholars have long been conscious of their importance. Instead of insisting upon the diversity of agents involved in these organizations, it also put some emphasis on the importance of the linkages and sharing between them and suggests some orientations in view of a performing evaluation system.
Pain after surgery remains a significant healthcare challenge. Here, abobotulinumtoxinA (aboBoNT-A, DYSPORT) was assessed in a post-surgical pain model in pigs. Full-skin-muscle incision and ...retraction surgery on the lower back was followed by intradermal injections of either aboBoNT-A (100, 200, or 400 U/pig), vehicle (saline), or wound infiltration of extended-release bupivacaine. We assessed mechanical sensitivity, distress behaviors, latency to approach the investigator, and wound inflammation/healing for 5-6 days post-surgery. We followed with immunohistochemical analyses of total and cleaved synaptosomal-associated protein 25 kD (SNAP25), glial fibrillary acidic protein (GFAP), ionized calcium-binding adaptor protein-1(Iba1), calcitonin gene-related peptide (CGRP) and substance P (SP) in the skin, dorsal root ganglia (DRG) and the spinal cord of 400 U aboBoNT-A- and saline-treated animals. At Day 1, partial reversal of mechanical allodynia in aboBoNT-A groups was followed by a full reversal from Day 3. Reduced distress and normalized approaching responses were observed with aboBoNT-A from 6 h post-surgery. Bupivacaine reversed mechanical allodynia for 24 h after surgery but did not affect distress or approaching responses. In aboBoNT-A-treated animals cleaved SNAP25 was absent in the skin and DRG, but present in the ipsilateral dorsal horn of the spinal cord. In aboBoNT-A- versus saline-treated animals there were significant reductions in GFAP and Iba1 in the spinal cord, but no changes in CGRP and SP. Analgesic efficacy of aboBoNT-A appears to be mediated by its activity on spinal neurons, microglia and astrocytes. Clinical investigation to support the use of aboBoNT-A as an analgesic drug for post-surgical pain, is warranted.
Limited experiments have compared the treatment effects of repetitive cycles of radiolabelled somatostatin (SST) analogues. In vitro and in vivo experiments were conducted in an AR42J cancer cell ...model, comparing the antagonist 177LuLu-satoreotide tetraxetan with the agonist 177LuLu-DOTA-TATE in terms of their binding properties, biodistribution, anti-tumour activity and toxicity. Histopathological and immunohistochemical examinations were performed at different timepoints. In the in vitro assays, 177LuLu-satoreotide tetraxetan recognised twice as many SST2 binding sites as 177LuLu-DOTA-TATE. In mice treated once a week for four consecutive weeks, 177LuLu-satoreotide tetraxetan (15 MBq) revealed a significantly greater median time taken to reach a tumour volume of 850 mm3 (68 days) compared to 177LuLu-DOTA-TATE at 15 MBq (43 days) or 30 MBq (48 days). This was associated with a higher tumour uptake, enhanced DNA damage and no or mild effects on body weight, haematological toxicity, or renal toxicity with 177LuLu-satoreotide tetraxetan (15 MBq). At the end of the study, complete tumour senescence was noted in 20% of animals treated with 177LuLu-satoreotide tetraxetan, in 13% of those treated with 177LuLu-DOTA-TATE at 30 MBq, and in none of those treated with 177LuLu-DOTA-TATE at 15 MBq. In conclusion, repeated administrations of 177LuLu-satoreotide tetraxetan were able to potentiate peptide receptor radionuclide therapy with a higher tumour uptake, longer median survival, and enhanced DNA damage, with a favourable efficacy/safety profile compared to 177LuLu-DOTA-TATE.
Botulinum neurotoxins (BoNTs) are used to treat spastic disorders. Depending on muscle size, one or multiple injections are recommended according to labels to target neuromuscular junctions (NMJ). ...However, information about NMJ distribution and number in muscles, as well as expression of receptors and molecular targets of toxins is scarce in human and animal models.
Seven muscles from adult rats were used to identify expression of BoNT receptors and SNAREs using immunohistochemistry (IHC), and fluorescent α-Bungarotoxin combined to light-sheet microscopy used to determine their distribution.
The location, number, and density of NMJ were muscle specific and mostly dependent on the type of pennation (myofiber orientation). In the Flexor Digitorum Brevis (a very small muscle) NMJ were as numerous as in the Gastrocnemius lateralis. A strong expression of SV2C, Synaptotagmin 2, SNAP25 and VAMP1 were observed in all muscles, and SV2A, Synaptotagmin 1 and VAMP2 were never detected.
This work highlights the specific distribution of NMJ in muscles which seems to depend on the type of pennation. Detailed observation of myofibers organization might help clinicians to better evaluate the location of NMJ in humans; the molecular phenotyping of NMJ will contribute to better integrate the rat model into research of BoNT therapeutics.
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•The location, number, and density of NMJ mostly dependent on the muscle pennation.•NMJ are strongly positive for SV2C, Synaptotagmin 2, SNAP25 and VAMP1.•NMJ are moderately positive for SV2B.•NMJ are negative for SV2A, Synaptotagmin 1 and VAMP2.•All muscles analyzed present with the same receptors and SNAREs distribution.
Histology is the gold standard to unveil microscopic brain structures and pathological alterations in humans and animal models of disease. However, due to tedious manual interventions, quantification ...of histopathological markers is classically performed on a few tissue sections, thus restricting measurements to limited portions of the brain. Recently developed 3D microscopic imaging techniques have allowed in-depth study of neuroanatomy. However, quantitative methods are still lacking for whole-brain analysis of cellular and pathological markers. Here, we propose a ready-to-use, automated, and scalable method to thoroughly quantify histopathological markers in 3D in rodent whole brains. It relies on block-face photography, serial histology and 3D-HAPi (Three Dimensional Histology Analysis Pipeline), an open source image analysis software. We illustrate our method in studies involving mouse models of Alzheimer's disease and show that it can be broadly applied to characterize animal models of brain diseases, to evaluate therapeutic interventions, to anatomically correlate cellular and pathological markers throughout the entire brain and to validate in vivo imaging techniques.
Sterol Regulatory Element Binding Protein-1c Expression and Action in Rat Muscles: Insulin-Like Effects on the Control of
Glycolytic and Lipogenic Enzymes and UCP3 Gene Expression
Isabelle ...Guillet-Deniau 1 ,
Virginie Mieulet 1 ,
Soazig Le Lay 2 ,
Younes Achouri 2 ,
Denis Carré 1 ,
Jean Girard 1 ,
Fabienne Foufelle 2 and
Pascal Ferré 2
1 UPR 1524 CNRS, Institut Cochin de Génétique Moléculaire, Paris, France
2 Unité INSERM 465, Centre de Recherches Biomédicales des Cordeliers, Université Paris VI, Paris, France
Abstract
Sterol regulatory element binding protein-1c (SREBP-1c) is a transcription factor that mediates insulin effects on hepatic
gene expression. It is itself transcriptionally stimulated by insulin in hepatocytes. Here we show that SREBP-1c mRNA is expressed
in adult rat skeletal muscles and that this expression is decreased by diabetes. The regulation of SREBP-1c expression was
then assessed in cultures of adult muscle satellite cells. These cells form spontaneously contracting multinucleated myotubes
within 7 days of culture. SREBP-1c mRNA is expressed in contracting myotubes. A 4-h treatment with 100 nmol/l insulin increases
SREBP-1c expression and nuclear abundance by two- to threefold in myotubes. In cultured myotubes, insulin increases the expression
of glycolytic and lipogenic enzyme genes and inhibits the 9-cis retinoic acid-induced UCP3 expression. These effects of insulin
are mimicked by adenovirus-mediated expression of a transcriptionally active form of SREBP-1c. We conclude that in skeletal
muscles, SREBP-1c expression is sensitive to insulin and can transduce the positive and negative actions of the hormone on
specific genes and thus has a pivotal role in long-term muscle insulin sensitivity.
Footnotes
Address correspondence and reprint requests to Isabelle Guillet-Deniau, Institut Cochin de Génétique Moléculaire, 24 rue du
Faubourg St-Jacques, 75014, Paris, France. E-mail: guillet-deniau{at}cochin.inserm.fr .
Received for publication 14 August 2001 and accepted in revised form 27 February 2002.
EDL, extensor digitorum longus; FAS, fatty acid synthase; HK, hexokinase; PPAR, peroxisome proliferator-activated receptor;
SREBP, sterol regulatory element binding protein; STZ, streptozotocin.
DIABETES
Although botulinum neurotoxin serotype A (BoNT/A) products are common treatments for various disorders, there is only one commercial BoNT/B product, whose low potency, likely stemming from low ...affinity toward its human receptor synaptotagmin 2 (hSyt2), has limited its therapeutic usefulness. We express and characterize two full-length recombinant BoNT/B1 proteins containing designed mutations E1191M/S1199Y (rBoNT/B1
) and E1191Q/S1199W (rBoNT/B1
) that enhance binding to hSyt2. In preclinical models including human-induced pluripotent stem cell neurons and a humanized transgenic mouse, this increased hSyt2 affinity results in high potency, comparable to that of BoNT/A. Last, we solve the cocrystal structure of rBoNT/B1
in complex with peptides of hSyt2 and its homolog hSyt1. We demonstrate that neuronal surface receptor binding limits the clinical efficacy of unmodified BoNT/B and that modified BoNT/B proteins have promising clinical potential.
Cell death is a common feature observed in neurodegenerative disorders, and is often associated with calpain activation and overproduction of reactive oxygen species (ROS). This study investigated ...the use of calpain inhibitors and antioxidants in combination to protect cells against necrosis. Maitotoxin (MTX), which induces a massive influx of calcium, was used to provoke neuronal cell death. This toxin increased, in a concentration‐dependent manner, both calpain activity and ROS formation. Calpain inhibitors or antioxidants inhibited MTX‐induced necrosis only marginally (below 20%), whereas their association protected against cell death by 40–66% in a synergistic manner. BN 82204, which possesses both calpain–cathepsin L inhibitory and antioxidant properties, and its acetylated pro‐drug BN 82270, totally protected cells at 100 µm. The pro‐drug BN 82270, which had better cell penetration, was twice as effective as the active principle BN 82204 in protecting glioma C6 or neuroblastoma SHSY5Y cells against death. These results suggest the potential therapeutic relevance of using a single molecule with multiple activities (cysteine protease inhibitor/antioxidant), and warrant further in vivo investigations in models of neuronal disorders.
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