Publications by authors named "Elena Bresciani"

31 Publications

Palmitoylethanolamide Modulation of Microglia Activation: Characterization of Mechanisms of Action and Implication for Its Neuroprotective Effects.

Int J Mol Sci 2021 Mar 17;22(6). Epub 2021 Mar 17.

School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy.

Palmitoylethanolamide (PEA) is an endogenous lipid produced on demand by neurons and glial cells that displays neuroprotective properties. It is well known that inflammation and neuronal damage are strictly related processes and that microglia play a pivotal role in their regulation. The aim of the present work was to assess whether PEA could exert its neuroprotective and anti-inflammatory effects through the modulation of microglia reactive phenotypes. In N9 microglial cells, the pre-incubation with PEA blunted the increase of M1 pro-inflammatory markers induced by lipopolysaccharide (LPS), concomitantly increasing those M2 anti-inflammatory markers. Images of microglial cells were processed to obtain a set of morphological parameters that highlighted the ability of PEA to inhibit the LPS-induced M1 polarization and suggested that PEA might induce the anti-inflammatory M2a phenotype. Functionally, PEA prevented Ca transients in both N9 cells and primary microglia and antagonized the neuronal hyperexcitability induced by LPS, as revealed by multi-electrode array (MEA) measurements on primary cortical cultures of neurons, microglia, and astrocyte. Finally, the investigation of the molecular pathway indicated that PEA effects are not mediated by toll-like receptor 4 (TLR4); on the contrary, a partial involvement of cannabinoid type 2 receptor (CB2R) was shown by using a selective receptor inverse agonist.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms22063054DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8002502PMC
March 2021

Androgen Therapy in Neurodegenerative Diseases.

J Endocr Soc 2020 Nov 21;4(11):bvaa120. Epub 2020 Aug 21.

School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.

Neurodegenerative diseases, including Alzheimer disease (AD), Parkinson disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), and Huntington disease, are characterized by the loss of neurons as well as neuronal function in multiple regions of the central and peripheral nervous systems. Several studies in animal models have shown that androgens have neuroprotective effects in the brain and stimulate axonal regeneration. The presence of neuronal androgen receptors in the peripheral and central nervous system suggests that androgen therapy might be useful in the treatment of neurodegenerative diseases. To illustrate, androgen therapy reduced inflammation, amyloid-β deposition, and cognitive impairment in patients with AD. As well, improvement in remyelination in MS have been reported; by comparison, only variable results are observed in androgen treatment of PD. In ALS, androgen administration stimulated motoneuron recovery from progressive damage and regenerated both axons and dendrites. Only a few clinical studies are available in human individuals despite the safety and low cost of androgen therapy. Clinical evaluations of the effects of androgen therapy on these devastating diseases using large populations of patients are strongly needed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1210/jendso/bvaa120DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7568521PMC
November 2020

Intranasal delivery of mesenchymal stem cell-derived extracellular vesicles exerts immunomodulatory and neuroprotective effects in a 3xTg model of Alzheimer's disease.

Stem Cells Transl Med 2020 09 4;9(9):1068-1084. Epub 2020 Jun 4.

School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.

The critical role of neuroinflammation in favoring and accelerating the pathogenic process in Alzheimer's disease (AD) increased the need to target the cerebral innate immune cells as a potential therapeutic strategy to slow down the disease progression. In this scenario, mesenchymal stem cells (MSCs) have risen considerable interest thanks to their immunomodulatory properties, which have been largely ascribed to the release of extracellular vesicles (EVs), namely exosomes and microvesicles. Indeed, the beneficial effects of MSC-EVs in regulating the inflammatory response have been reported in different AD mouse models, upon chronic intravenous or intracerebroventricular administration. In this study, we use the triple-transgenic 3xTg mice showing for the first time that the intranasal route of administration of EVs, derived from cytokine-preconditioned MSCs, was able to induce immunomodulatory and neuroprotective effects in AD. MSC-EVs reached the brain, where they dampened the activation of microglia cells and increased dendritic spine density. MSC-EVs polarized in vitro murine primary microglia toward an anti-inflammatory phenotype suggesting that the neuroprotective effects observed in transgenic mice could result from a positive modulation of the inflammatory status. The possibility to administer MSC-EVs through a noninvasive route and the demonstration of their anti-inflammatory efficacy might accelerate the chance of a translational exploitation of MSC-EVs in AD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/sctm.19-0327DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7445021PMC
September 2020

JMV5656, a short synthetic derivative of TLQP-21, alleviates acid-induced lung injury and fibrosis in mice.

Pulm Pharmacol Ther 2020 06 20;62:101916. Epub 2020 Mar 20.

School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.

TLQP-21, a peptide encoded by the prohormone VGF, is expressed in neuroendocrine cells and can modulate inflammatory processes. Since TLQP-21 can bind the complement 3a receptor 1 on macrophages, interest has risen in this peptide as a potential drug for the treatment of Acute Respiratory Distress Syndrome (ARDS), whose hospital mortality can reach 35-46%. Since no effective pharmacologic therapies are available, our aim was to exploit the potential of a short analog of TLQP-21(JMV5656) in order to modulate the inflammatory process in ARDS and the progression to pulmonary fibrosis in an experimental model of unilateral acid aspiration in mice. Mice were divided in 2 treatment groups. In the acute protocol, mice received intra-peritoneal injection of either vehicle or 0.6 mg/kg JMV5656 on experimental days 1 and 2, and ARDS was induced on day 3 under deep anesthesia by instillation of HCl (1.5 ml/kg of 0.1 M HCl in 0.9% NaCl) into the right lung; all measurements were performed 24 h later. In the subacute protocol, mice were treated as previously, but treatment with vehicle or JMV5656 was repeated also on day 4 and measurements were made 2 weeks later. Twenty-four hours after acid instillation, the total number of immune cell in the BAL rose sharply due primarily to an increase in the PMN population which increased from 1% up to 58% of total cell numbers. JMV5656 significantly reduced PMN recruitment into the alveolar space, but had no effects on cytokine levels in BAL. Two weeks after acid injury, static compliance of the right lung was significantly higher in the JMV5656-treated group compared to vehicle-treated group. Treatment with JMV5656 also blunted the acid-induced collagen deposition in the right lung. These results suggest that JMV5656 can ameliorate mechanical compliance, and reduce collagen deposition in acid-injured lungs in mice. This effect was likely due to the ability of JMV5656 to inhibit PMN recruitment in the injured lung.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.pupt.2020.101916DOI Listing
June 2020

Cisplatin-Induced Skeletal Muscle Dysfunction: Mechanisms and Counteracting Therapeutic Strategies.

Int J Mol Sci 2020 Feb 13;21(4). Epub 2020 Feb 13.

Department of Pharmacy-Drug Sciences, University of Bari, 70125 Bari, Italy.

Among the severe side effects induced by cisplatin chemotherapy, muscle wasting is the most relevant one. This effect is a major cause for a clinical decline of cancer patients, since it is a negative predictor of treatment outcome and associated to increased mortality. However, despite its toxicity even at low doses, cisplatin remains the first-line therapy for several types of solid tumors. Thus, effective pharmacological treatments counteracting or minimizing cisplatin-induced muscle wasting are urgently needed. The dissection of the molecular pathways responsible for cisplatin-induced muscle dysfunction gives the possibility to identify novel promising therapeutic targets. In this context, the use of animal model of cisplatin-induced cachexia is very useful. Here, we report an update of the most relevant researches on the mechanisms underlying cisplatin-induced muscle wasting and on the most promising potential therapeutic options to preserve muscle mass and function.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms21041242DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7072891PMC
February 2020

TLQP-21, A VGF-Derived Peptide Endowed of Endocrine and Extraendocrine Properties: Focus on In Vitro Calcium Signaling.

Int J Mol Sci 2019 Dec 24;21(1). Epub 2019 Dec 24.

School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy.

VGF gene encodes for a neuropeptide precursor of 68 kDa composed by 615 (human) and 617 (rat, mice) residues, expressed prevalently in the central nervous system (CNS), but also in the peripheral nervous system (PNS) and in various endocrine cells. This precursor undergoes proteolytic cleavage, generating a family of peptides different in length and biological activity. Among them, TLQP-21, a peptide of 21 amino acids, has been widely investigated for its relevant endocrine and extraendocrine activities. The complement complement C3a receptor-1 (C3aR1) has been suggested as the TLQP-21 receptor and, in different cell lines, its activation by TLQP-21 induces an increase of intracellular Ca. This effect relies both on Ca release from the endoplasmic reticulum (ER) and extracellular Ca entry. The latter depends on stromal interaction molecules (STIM)-Orai1 interaction or transient receptor potential channel (TRPC) involvement. After Ca entry, the activation of outward K-Ca-dependent currents, mainly the K currents, provides a membrane polarizing influence which offset the depolarizing action of Ca elevation and indirectly maintains the driving force for optimal Ca increase in the cytosol. In this review, we address the main endocrine and extraendocrine actions displayed by TLQP-21, highlighting recent findings on its mechanism of action and its potential in different pathological conditions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms21010130DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6982260PMC
December 2019

Growth Hormone Secretagogues and the Regulation of Calcium Signaling in Muscle.

Int J Mol Sci 2019 Sep 5;20(18). Epub 2019 Sep 5.

School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy.

Growth hormone secretagogues (GHS) are a family of synthetic molecules, first discovered in the late 1970s for their ability to stimulate growth hormone (GH) release. Many effects of GHS are mediated by binding to GHS-R1a, the receptor for the endogenous hormone ghrelin, a 28-amino acid peptide isolated from the stomach. Besides endocrine functions, both ghrelin and GHS are endowed with some relevant extraendocrine properties, including stimulation of food intake, anticonvulsant and anti-inflammatory effects, and protection of muscle tissue in different pathological conditions. In particular, ghrelin and GHS inhibit cardiomyocyte and endothelial cell apoptosis and improve cardiac left ventricular function during ischemia-reperfusion injury. Moreover, in a model of cisplatin-induced cachexia, GHS protect skeletal muscle from mitochondrial damage and improve lean mass recovery. Most of these effects are mediated by GHS ability to preserve intracellular Ca homeostasis. In this review, we address the muscle-specific protective effects of GHS mediated by Ca regulation, but also highlight recent findings of their therapeutic potential in pathological conditions characterized by skeletal or cardiac muscle impairment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijms20184361DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6769538PMC
September 2019

miRNA-218 Targets Lipin-1 and Glucose Transporter Type 4 Genes in 3T3-L1 Cells Treated With Lopinavir/Ritonavir.

Front Pharmacol 2019 30;10:461. Epub 2019 Apr 30.

School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.

Metabolic complications represent a common and serious problem associated with HIV infection and combined Antiretroviral Therapy (cART). Alterations in body fat distribution are associated with significantly increased risks of (i) metabolic derangements, (ii) cardiovascular pathologies, and (iii) insulin resistance. A case control study showed that in subcutaneous adipose tissue from HIV-infected patients on cART presenting lipodystrophy (LS), the levels of miRNA-218 were upregulated and those of lipin-1, a putative target gene of miRNA-218, were downregulated compared with HIV-negative subjects. Lipin-1 is one of the most important factors linked to development of LS. Lipin-1, by controlling PPARγ2, regulates the expression of specific genes, such as that of glucose transporter type 4 (GLUT-4), required for maturation and maintenance of adipocytes. To determine whether lopinavir/ritonavir (LPV/RTV) can modulate lipogenesis in adipocytes affecting miRNA-218 and lipin-1 mRNA expression, and to investigate the functional link between miRNA-218 and GLUT-4 mRNA expression. Differentiated 3T3-L1 cells were treated with various combinations of LPV/RTV, followed by measurements of cell viability, lipid accumulation, lipin-1 and GLUT-4 mRNA and miRNA-218 levels. Transfection of anti-miR-218 or a miRNA-218 mimic were used to investigate the role of miRNA-218 in lipogenesis. LPV/RTV treatment of 3T3-L1 cells did not affect the viability of differentiated 3T3-L1 cells, but caused (i) a significant decrease of lipid accumulation, (ii) an overexpression of miRNA-218, and (iii) a reduction of lipin-1 and GLUT-4 mRNA levels. The anti-miR-218 transfection of 3T3-L1 cells significantly ameliorated the adipogenic dysfunction and restored mRNA levels of lipin-1 and GLUT-4 consequent to LPV/RTV treatment. By contrast, 3T3-L1 cells transfected with a specific miRNA-218 mimic showed (i) an overexpression of miRNA-218, (ii) a reduced cellular lipid fraction, and (iii) decreased levels of mRNA for lipin-1 and GLUT-4. 3T3-L1 cells, treated with LPV/RTV, show altered lipid content due to increased miRNA-218 levels, which affects lipin-1 mRNA. Moreover, increased miRNA-218 levels were inversely correlated with changes in GLUT-4 expression, which suggests a role for miRNA-218 in mediating the insulin resistance consequent to cART.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fphar.2019.00461DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6524698PMC
April 2019

Angiotensin-(1-7) exerts a protective action in a rat model of ventilator-induced diaphragmatic dysfunction.

Intensive Care Med Exp 2019 Jan 18;7(1). Epub 2019 Jan 18.

Department of Medicine, University of Milano-Bicocca, Monza, Italy.

Background: Ventilator-induced diaphragmatic dysfunction (VIDD) is a common event during mechanical ventilation (MV) leading to rapid muscular atrophy and contractile dysfunction. Recent data show that renin-angiotensin system is involved in diaphragmatic skeletal muscle atrophy after MV. In particular, angiotensin-II can induce marked diaphragm muscle wasting, whereas angiotensin-(1-7) (Ang-(1-7)) could counteract this activity. This study was designed to evaluate the effects of the treatment with Ang-(1-7) in a rat model of VIDD with neuromuscular blocking agent infusion. Moreover, we studied whether the administration of A-779, an antagonist of Ang-(1-7) receptor (Mas), alone or in combination with PD123319, an antagonist of AT2 receptor, could antagonize the effects of Ang-(1-7).

Methods: Sprague-Dawley rats underwent prolonged MV (8 h), while receiving an iv infusion of sterile saline 0.9% (vehicle) or Ang-(1-7) or Ang-(1-7) + A-779 or Ang-(1-7) + A-779 + PD123319. Diaphragms were collected for ex vivo contractility measurement (with electric stimulation), histological analysis, quantitative real-time PCR, and Western blot analysis.

Results: MV resulted in a significant reduction of diaphragmatic contractility in all groups of treatment. Ang-(1-7)-treated rats showed higher muscular fibers cross-sectional area and lower atrogin-1 and myogenin mRNA levels, compared to vehicle treatment. Treatment with the antagonists of Mas and Ang-II receptor 2 (AT2R) caused a significant reduction of muscular contractility and an increase of atrogin-1 and MuRF-1 mRNA levels, not affecting the cross-sectional fiber area and myogenin mRNA levels.

Conclusions: Systemic Ang-(1-7) administration during MV exerts a protective role on the muscular fibers of the diaphragm preserving muscular fibers anatomy, and reducing atrophy. The involvement of Mas and AT2R in the mechanism of action of Ang-(1-7) still remains controversial.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s40635-018-0218-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6338614PMC
January 2019

STIM Proteins and Orai Ca Channels Are Involved in the Intracellular Pathways Activated by TLQP-21 in RAW264.7 Macrophages.

Front Pharmacol 2018 27;9:1386. Epub 2018 Nov 27.

School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.

TLQP-21 is a neuropeptide which has been implicated in regulation of nociception and other relevant physiologic functions. Although recent studies identified C3a and gC1q receptors as targets for TLQP-21, its intracellular molecular mechanisms of action remain largely unidentified. Our aim was (i) to explore the intracellular signaling pathway(s) activated by JMV5656, a novel derivative of TLQP-21, in RAW264.7 macrophages, and (ii) to assess linkages of these pathways with its purported receptors. JMV5656 stimulated, in a dose-dependent fashion, a rapid and transient increase in intracellular Ca concentrations in RAW264.7 cells; repeated exposure to the peptide resulted in a lower response, suggesting a possible desensitization mechanism of the receptor. In particular, JMV5656 increased cytoplasmic Ca levels by a PLC-dependent release of Ca from the endoplasmic reticulum. STIM proteins and Orai Ca channels were activated and played a crucial role. In fact, treatment of the cells with U73122 and thapsigargin modulated the increase of intracellular Ca levels stimulated by JMV5656. Moreover, in RAW264.7 cells intracellular Ca increases did not occur through the binding of JMV5656 to the C3a receptor, since the increase of intracellular Ca levels induced by JMV5656 was not affected by specific siRNA against C3aR. In summary, our study provides new indications for the downstream effects of JMV5656 in macrophages, suggesting that it could activate receptors different from the C3aR.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fphar.2018.01386DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6277904PMC
November 2018

Study of the Tissue Distribution of TLQP-21 in Mice Using [F]JMV5763, a Radiolabeled Analog Prepared via [F]Aluminum Fluoride Chelation Chemistry.

Front Pharmacol 2018 13;9:1274. Epub 2018 Nov 13.

School of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy.

TLQP-21 is a neuropeptide that is involved in the control of several physiological functions, including energy homeostasis. Since TLQP-21 could oppose the early phase of diet-induced obesity, it has raised a huge interest, but very little is known about its mechanisms of action on peripheral tissues. Our aim was to investigate TLQP-21 distribution in brain and peripheral tissues after systemic administration using positron emission tomography. We report here the radiolabeling of NODA-methyl phenylacetic acid (MPAA) functionalized JMV5763, a short analog of TLQP-21, with [F]aluminum fluoride. Labeling of JMV5763 was initially performed manually, on a small scale, and then optimized and implemented on a fully automated radiosynthesis system. In the first experiment, mice were injected in the tail vein with [F]JMV5763, and central and peripheral tissues were collected 13, 30, and 60 min after injection. Significant uptake of [F]JMV5763 was found in stomach, intestine, kidney, liver, and adrenal gland. In the CNS, very low uptake values were measured in all tested areas, suggesting that the tracer does not efficiently cross the blood-brain barrier. Pretreatment with non-radioactive JMV5763 caused a significant reduction of tracer uptake only in stomach and intestine. In the second experiment, PET analysis was performed 10-120 min after i.v. [F]JMV5763 administration. Results were consistent with those of the determinations. PET images showed a progressive increase of [F]JMV5763 uptake in intestine and stomach reaching a peak at 30 min, and decreasing at 120 min. Our results demonstrate that F-labeling of TLQP-21 analogs is a suitable method to study its distribution in the body.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fphar.2018.01274DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6277862PMC
November 2018

Pharmacological and Biochemical Characterization of TLQP-21 Activation of a Binding Site on CHO Cells.

Front Pharmacol 2017 30;8:167. Epub 2017 Mar 30.

Department of Medicine and Surgery, University of Milano-BicoccaMonza, Italy.

VGF is a propeptide of 617 amino acids expressed throughout the central and the peripheral nervous system. VGF and peptides derived from its processing have been found in dense core vesicles and are released from neuronal and neuroendocrine cells via the regulated secretory pathway. Among VGF-derived neuropeptides, TLQP-21 (VGF) has raised a huge interest and is one of most studied. TLQP-21 is a multifunctional neuropeptide involved in the control of several physiological functions, potentially including energy homeostasis, pain modulation, stress responsiveness and reproduction. Although little information is available about its receptor and the intracellular mechanisms mediating its biological effects, recent reports suggest that TLQP-21 may bind to the complement receptors C3aR1 and/or gC1qR. The first aim of this study was to ascertain the existence and nature of TLQP-21 binding sites in CHO cells. Secondly, we endeavored to characterize the ligand binding to these sites by using a small panel of VGF-derived peptides. And finally, we investigated the influence of TLQP-21 on selected intracellular signaling pathways. We report that CHO cells express a single class of saturable and specific binding sites for TLQP-21 with an affinity and capacity of = 0.55 ± 0.05 × 10 M and 81.7 ± 3.9 fmol/mg protein, respectively. Among the many bioactive products derived from the C-terminal region of VGF that we tested, TLQP-21 was the most potent in stimulating intracellular calcium mobilization in CHO cells; this effect is primarily due to its C-terminal fragment (HFHH-10). TLQP-21 induced rapid and transient dephosphorylation of phospholipase Cγ1 and phospholipase A2. Generation of IP and diacylglycerol was crucial for TLQP-21 bioactivity. In conclusion, our results suggest that the receptor stimulated by TLQP-21 belongs to the family of the G-coupled receptors, and its activation first increases membrane-lipid derived second messengers which thereby induce the mobilization of Ca from the endoplasmic reticulum followed by a slower store-operated Ca entry from outside the cell.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fphar.2017.00167DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5371653PMC
March 2017

Growth hormone secretagogues prevent dysregulation of skeletal muscle calcium homeostasis in a rat model of cisplatin-induced cachexia.

J Cachexia Sarcopenia Muscle 2017 Jun 10;8(3):386-404. Epub 2017 Mar 10.

Department of Pharmacy - Drug Sciences, University of Bari, Via Orabona 4, 70125, Bari, Italy.

Background: Cachexia is a wasting condition associated with cancer types and, at the same time, is a serious and dose-limiting side effect of cancer chemotherapy. Skeletal muscle loss is one of the main characteristics of cachexia that significantly contributes to the functional muscle impairment. Calcium-dependent signaling pathways are believed to play an important role in skeletal muscle decline observed in cachexia, but whether intracellular calcium homeostasis is affected in this situation remains uncertain. Growth hormone secretagogues (GHS), a family of synthetic agonists of ghrelin receptor (GHS-R1a), are being developed as a therapeutic option for cancer cachexia syndrome; however, the exact mechanism by which GHS interfere with skeletal muscle is not fully understood.

Methods: By a multidisciplinary approach ranging from cytofluorometry and electrophysiology to gene expression and histology, we characterized the calcium homeostasis in fast-twitch extensor digitorum longus (EDL) muscle of adult rats with cisplatin-induced cachexia and established the potential beneficial effects of two GHS (hexarelin and JMV2894) at this level. Additionally, in vivo measures of grip strength and of ultrasonography recordings allowed us to evaluate the functional impact of GHS therapeutic intervention.

Results: Cisplatin-treated EDL muscle fibres were characterized by a ~18% significant reduction of the muscle weight and fibre diameter together with an up-regulation of atrogin1/Murf-1 genes and a down-regulation of Pgc1-a gene, all indexes of muscle atrophy, and by a two-fold increase in resting intracellular calcium, [Ca ] , compared with control rats. Moreover, the amplitude of the calcium transient induced by caffeine or depolarizing high potassium solution as well as the store-operated calcium entry were ~50% significantly reduced in cisplatin-treated rats. Calcium homeostasis dysregulation parallels with changes of functional ex vivo (excitability and resting macroscopic conductance) and in vivo (forelimb force and muscle volume) outcomes in cachectic animals. Administration of hexarelin or JMV2894 markedly reduced the cisplatin-induced alteration of calcium homeostasis by both common as well as drug-specific mechanisms of action. This effect correlated with muscle function preservation as well as amelioration of various atrophic indexes, thus supporting the functional impact of GHS activity on calcium homeostasis.

Conclusions: Our findings provide a direct evidence that a dysregulation of calcium homeostasis plays a key role in cisplatin-induced model of cachexia gaining insight into the etiopathogenesis of this form of muscle wasting. Furthermore, our demonstration that GHS administration efficaciously prevents cisplatin-induced calcium homeostasis alteration contributes to elucidate the mechanism of action through which GHS could potentially ameliorate chemotherapy-associated cachexia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jcsm.12185DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5703021PMC
June 2017

JMV5656, A Novel Derivative of TLQP-21, Triggers the Activation of a Calcium-Dependent Potassium Outward Current in Microglial Cells.

Front Cell Neurosci 2017 23;11:41. Epub 2017 Feb 23.

Department of Medicine and Surgery, University of Milano-Bicocca Monza, Italy.

TLQP-21 (TLQPPASSRRRHFHHALPPAR) is a multifunctional peptide that is involved in the control of physiological functions, including feeding, reproduction, stress responsiveness, and general homeostasis. Despite the huge interest in TLQP-21 biological activity, very little is known about its intracellular mechanisms of action. In microglial cells, TLQP-21 stimulates increases of intracellular Ca that may activate functions, including proliferation, migration, phagocytosis and production of inflammatory molecules. Our aim was to investigate whether JMV5656 (RRRHFHHALPPAR), a novel short analogue of TLQP-21, stimulates intracellular Ca in the N9 microglia cells, and whether this Ca elevation is coupled with the activation Ca-sensitive K channels. TLQP-21 and JMV5656 induced a sharp, dose-dependent increment in intracellular calcium. In 77% of cells, JMV5656 also caused an increase in the total outward currents, which was blunted by TEA (tetraethyl ammonium chloride), a non-selective blocker of voltage-dependent and Ca-activated potassium (K) channels. Moreover, the effects of ion channel blockers charybdotoxin and iberiotoxin, suggested that multiple calcium-activated K channel types drove the outward current stimulated by JMV5656. Additionally, inhibition of JMV5656-stimulated outward currents by NS6180 (4-[[3-(trifluoromethyl)phenyl]methyl]-2H-1,4 benzothiazin-3(4H)-one) and TRAM-34 (triarylmethane-34), indicated that K3.1 channels are involved in this JMV5656 mechanisms of action. In summary, we demonstrate that, in N9 microglia cells, the interaction of JMV5656 with the TLQP-21 receptors induced an increase in intracellular Ca, and, following extracellular Ca entry, the opening of K3.1 channels.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fncel.2017.00041DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5322282PMC
February 2017

JMV2894, a novel growth hormone secretagogue, accelerates body mass recovery in an experimental model of cachexia.

Endocrine 2017 Oct 28;58(1):106-114. Epub 2016 Nov 28.

Department of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.

Oncologic patients subjected to chemotherapy frequently present aphagia, malnutrition, and cachexia. The purpose of this study was to investigate whether selected growth hormone secretagogues including hexarelin, JMV2894 and JMV2951 could antagonize body weight loss and wasting induced by cisplatin administration in rats. The three growth hormone secretagogues behaved as full agonists of the growth hormone secretagogues receptor both in terms of ability to stimulate calcium mobilization in Chinese hamster ovary cells and stimulation of growth hormone release in neonatal rats. Adult rats were (i) treated with vehicle throughout (controls), or (ii) treated with cisplatin (days 1-3) and a growth hormone secretagogues or vehicle, (days 1-12). Body weight and food consumption were measured daily. Although all growth hormone secretagogues caused initial transient acute increases in food intake, the total amount of food eaten by controls and growth hormone secretagogues treated groups over the 12 experimental days was not significantly different. All groups pre-treated with cisplatin lost up to 5-10 % body weight in the first 4 days; they subsequently gained weight at a rate comparable with controls. Interestingly, rats which received JMV2894 demonstrated a faster gain in body weight than any other growth hormone secretagogues treated group and at the end of the protocol reached a weight similar to that of controls. JMV2894 did not stimulate perirenal and epididymal fat accumulation but reduced MuRF mRNA levels in skeletal muscles. In conclusion, our findings demonstrate that JMV2894 antagonizes cisplatin induced weight loss in rats and may prove useful in antagonizing cachexia associated with cancer and chemotherapy in humans.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12020-016-1184-2DOI Listing
October 2017

Characterization of synovial fluid cytokine profiles in chronic meniscal tear of the knee.

J Orthop Res 2017 02 2;35(2):340-346. Epub 2016 May 2.

Department of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy.

Concentrations of pro- and anti-inflammatory cytokines in synovial fluid samples collected from patients with chronic meniscal tears were investigated. An acute inflammatory response is generally reported 24-48 h after knee injury, but the largest body of data available in literature concerns anterior cruciate ligament injury and very little information is available about the balance of soluble factors in the synovial fluid of knees with chronic meniscal tears. Sixty-nine patients (46 males and 23 females) with meniscal tear that occurred more than 3 months earlier were enrolled. According to cartilage integrity assessment by arthroscopic examination, patients were assigned to one of the following groups: (i) no chondral damage (n = 18); (ii) chondral damage graded from I to II (n = 15); and (iii) chondral damage graded from III to IV (n = 37). In all groups, levels of IL-10 and inflammatory cytokines IL-6, TNF-α, and IL-8 where greater compared with those reported in the intact population; by contrast, levels of IL-1ra and IL-1β were significantly lower. Interestingly, IL-6 levels were higher in female than male patients. Cytokine levels did not correlate with degree of chondral damage. IL-6 and IL-1ra levels positively correlated with IL-1β, and negatively correlated with TNF-α. Interestingly, levels of IL-1β and TNF-α were inversely correlated. Our data demonstrate increased levels of pro-inflammatory cytokines (IL-6, IL-8, and TNF-α) in the chronic phase of meniscal trauma. This pro-inflammatory state is maintained in the joint from the time of initial injury to several months later and could be a key factor in hampering cartilage regeneration. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:340-346, 2017.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jor.23272DOI Listing
February 2017

Regression of Renal Disease by Angiotensin II Antagonism Is Caused by Regeneration of Kidney Vasculature.

J Am Soc Nephrol 2016 Mar 26;27(3):699-705. Epub 2015 Jun 26.

IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Centro Anna Maria Astori, Science and Technology Park Kilometro Rosso Bergamo, Italy; Unit of Nephrology and Dialysis, Azienda Ospedaliera Papa Giovanni XXIII, Bergamo, Italy.

Chronic renal insufficiency inexorably progresses in patients, such as it does after partial renal ablation in rats. However, the progression of renal diseases can be delayed by angiotensin II blockers that stabilize renal function or increase GFR, even in advanced phases of the disease. Regression of glomerulosclerosis can be induced by angiotensin II antagonism, but the effect of these treatments on the entire vascular tree is unclear. Here, using microcomputed tomography and scanning electron microscopy, we compared the size and extension of kidney blood vessels in untreated Wistar rats with those in untreated and angiotensin II antagonist-treated Munich Wistar Frömter (MWF) rats that spontaneously develop kidney disease with age. The kidney vasculature underwent progressive rarefaction in untreated MWF rats, substantially affecting intermediate and small vessels. Microarray analysis showed increased Tgf-β and endothelin-1 gene expression with age. Notably, 10-week inhibition of the renin-angiotensin system regenerated kidney vasculature and normalized Tgf-β and endothelin-1 gene expression in aged MWF rats. These changes were associated with reduced apoptosis, increased endothelial cell proliferation, and restoration of Nrf2 expression, suggesting mechanisms by which angiotensin II antagonism mediates regeneration of capillary segments. These results have important implications in the clinical setting of chronic renal insufficiency.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1681/ASN.2014100971DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4769186PMC
March 2016

Changes in subcutaneous adipose tissue microRNA expression in HIV-infected patients.

J Antimicrob Chemother 2014 Nov 25;69(11):3067-75. Epub 2014 Jul 25.

Division of Infectious Diseases, Department of Internal Medicine, San Gerardo Hospital, Monza, Italy Department of Health Sciences, School of Medicine, University of Milano-Bicocca, Monza, Italy.

Objectives: We evaluated the possibility that a pattern of abnormal microRNA (miRNA) expression could be fuelling the mechanisms causing HIV-associated lipodystrophy (HAL).

Methods: In this case-control study, samples of subcutaneous adipose tissue from eight consecutive HIV-infected patients on combination antiretroviral therapy with HAL (cases) were compared with those of eight HIV-negative subjects (controls). Human miRNA microarrays were used to probe the transcriptomes of the samples. Analysis of differentially expressed miRNAs was performed using DataAssist v2.0 software, applying a paired Student's t-test.

Results: Data showed that 21 miRNAs out of 754 were overexpressed in the patient group. Ten of these (i.e. miR-186, miR-199a-3p, miR-214, miR-374a, miR-487b, miR-532-5p, miR-628-5p, miR-874, miR-125-b-1* and miR-374b*) were up-regulated to a significant degree (fold change >2.5; P < 0.01). Eleven other miRNAs (i.e. miR-let-7d, miR-24, miR-30c, miR-125a-3p, miR-149, miR-191, miR-196-b, miR-218, miR-342-3p, miR-452 and miR-454*) were 2- to 2.5-fold more expressed in HIV+ samples than in controls. Levels of mRNA for lipin 1, the target of miR-218, were significantly lower in subcutaneous adipose tissue from HIV patients.

Conclusions: In adipocytes of HIV-infected patients, the up-regulation of specific miRNAs could lead to an increased 'activation' that might contribute to the pathogenesis of HAL by increasing cell turnover and/or promotion of apoptosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/jac/dku264DOI Listing
November 2014

Protective but not anticonvulsant effects of ghrelin and JMV-1843 in the pilocarpine model of Status epilepticus.

PLoS One 2013 28;8(8):e72716. Epub 2013 Aug 28.

Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy.

In models of status epilepticus ghrelin displays neuroprotective effects mediated by the growth hormone secretagogue-receptor 1a (GHS-R1a). This activity may be explained by anticonvulsant properties that, however, are controversial. We further investigated neuroprotection and the effects on seizures by comparing ghrelin with a more effective GHS-R1a agonist, JMV-1843. Rats were treated either with ghrelin, JMV-1843 or saline 10 min before pilocarpine, which was used to induce status epilepticus. Status epilepticus, developed in all rats, was attenuated by diazepam. No differences were observed among the various groups in the characteristics of pilocarpine-induced seizures. In saline group the area of lesion, characterized by lack of glial fibrillary acidic protein immunoreactivity, was of 0.45 ± 0.07 mm(2) in the hippocampal stratum lacunosum-moleculare, and was accompanied by upregulation of laminin immunostaining, and by increased endothelin-1 expression. Both ghrelin (P<0.05) and JMV-1843 (P<0.01) were able to reduce the area of loss in glial fibrillary acidic protein immunostaining. In addition, JMV-1843 counteracted (P<0.05) the changes in laminin and endothelin-1 expression, both increased in ghrelin-treated rats. JMV-1843 was able to ameliorate neuronal survival in the hilus of dentate gyrus and medial entorhinal cortex layer III (P<0.05 vs saline and ghrelin groups). These results demonstrate diverse protective effects of growth hormone secretagogues in rats exposed to status epilepticus.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0072716PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3755992PMC
March 2014

Acute and late changes in intraarticular cytokine levels following anterior cruciate ligament injury.

J Orthop Res 2013 Feb 6;31(2):315-21. Epub 2012 Aug 6.

Orthopedic Department, San Gerardo Hospital, 20900 Monza, Italy.

Surgical reconstruction of the anterior cruciate ligament (ACL) does not necessarily decrease the risk of developing osteoarthritis (OA). The inflammatory response and relative changes in pro- and anti-inflammatory cytokines could participate in triggering the development of OA. To test this hypothesis we measured the concentrations of IL-1β, IL-1ra, IL-6, IL-8, IL-10, and TNF-α at different times after ACL rupture. The sample population consisted of 48 patients with ACL tear which were assigned to different groups according to the time elapsed from the injury: 22 acute (A), 7 early sub-acute (ESA), 11 late sub-acute (LSA), and 8 chronic (C). In group A, there were high levels of IL-1β, IL-6, and IL-8, whereas levels of IL-1ra and TNF-α were significantly lower than usually reported. IL-1β and IL-8 concentrations returned with time to normal levels in the ESA group. Interestingly, IL-1ra levels remained always significantly lower than normally reported levels, and TNF-α levels did not increase after trauma. Our data show increased level of pro-inflammatory cytokines (IL-6 and IL-8) in the acute phase of inflammation which could be responsible for triggering cartilage catabolism and suggest that prompt neutralization of IL-6 and IL-8 accumulations in synovial fluid could help prevent development of OA in ACL-injured knees.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jor.22208DOI Listing
February 2013

Novel domain-selective ACE-inhibiting activity of synthetic growth hormone secretagogues.

Pharmacol Res 2012 Oct 23;66(4):317-24. Epub 2012 Jun 23.

Department of Experimental Medicine, University of Milano-Bicocca, Via Cadore 48, 20900 Monza, Italy.

The mechanisms of cardiovascular protective effects of ghrelin and its synthetic analogs are still largely unknown. Our first aim was to ascertain whether or not natural and synthetic ligands of GHS-R1a are capable of interfering with the activity of the renin-angiotensin system. Second, since polymorphisms in the ACE gene have been associated with Alzheimer's dementia (AD) and ACE is potentially involved in brain β-amyloid degradation, we also investigated the state of ghrelin axis and inflammatory markers in patients with AD and vascular dementia (VaD). Desacyl ghrelin, hexarelin, EP80317, and GHRP-6 all significantly inhibited ACE activity in vitro; by comparison, the efficacies of ghrelin and MK-0677 were significantly lower, suggesting that ACE-inhibiting activity is unrelated to ligand affinity to GHS-R1a. ACE was capable of cleaving Aβin vitro, reducing its ability to aggregate in fibrillar Aβ. Interestingly, this protective effect of ACE was blunted by enalapril but not hexarelin or EP80317. Desacyl ghrelin levels were lower in VaD subjects compared with AD and control subjects, whereas ghrelin and TNF-α levels were similar in all groups. VaD subjects demonstrated greater levels of mRNA for GHS-R1a, PPAR-γ and CD36 in peripheral blood lymphocytes compared with other groups. In conclusion, some GHSs are effective ACE-inhibitors, and this activity may contribute to their cardiovascular effects. Hexarelin or EP80317 do not inhibit the N-domain of ACE, which is also involved in the metabolism of β-amyloid, suggesting the possibility of developing new antihypertensive drugs with improved therapeutic potential.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.phrs.2012.06.006DOI Listing
October 2012

Beneficial effects of desacyl-ghrelin, hexarelin and EP-80317 in models of status epilepticus.

Eur J Pharmacol 2011 Nov 2;670(1):130-6. Epub 2011 Sep 2.

Department of Biomedical Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy.

It has been reported that ghrelin exerts anticonvulsive effects in models of epilepsy. In this study we aimed to characterize the anticonvulsive activity of ghrelin and other growth hormone secretagogue receptor 1a (GHSR(1a)) ligands in rats exposed to status epilepticus induced by pilocarpine or kainate. Firstly, in three independent experiments, before receiving pilocarpine (380 mg/kg, i.p.), rats were pretreated with one among ghrelin (1.5mg/kg), desacyl-ghrelin (1.5mg/kg), hexarelin (330 μg/kg), EP-80317 (330 μg/kg), JMV-1843 (330 μg/kg), JMV-2959 (330 μg/kg) or saline. Secondly, in the fourth experiment, rats were pretreated with i.p. ghrelin, desacyl-ghrelin, hexarelin, EP-80317 or saline, followed by kainate (15 mg/kg, i.p.). We evaluated: induction of generalized seizures, latency to generalized seizures, status epilepticus, latency to status epilepticus (the time lag between the first tonic-clonic convulsion and the switch to continuous seizures) and mortality. In the pilocarpine model, 60% of rats pretreated with EP-80317 (P<0.05) showed no seizure. Hexarelin and EP-80317 were both able to prevent progression to status epilepticus in pilocarpine-treated rats (P<0.05). When status epilepticus was induced by kainate, seizures developed with few exceptions. However, latency to status epilepticus was significantly (P<0.01) longer in rats pretreated with desacyl-ghrelin, whereas hexarelin and EP-80317 did not display any effect. Almost all GHSR(1a) ligands prevented pilocarpine-induced mortality, which was observed only in rats pretreated with saline or JMV-2959. After kainate administration, all rats survived to status epilepticus. These findings demonstrate that desacyl-ghrelin, hexarelin and EP-80317 but not other GHSR(1a) ligands display relevant anticonvulsive properties in models of limbic seizures.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejphar.2011.08.020DOI Listing
November 2011

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

Biochem J 2012 Jan;441(1):511-22

Department of Drug Science and Technology, University of Turin, Turin, Italy.

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.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1042/BJ20111165DOI Listing
January 2012

Evaluation of a 3D stereophotogrammetric technique to measure the stone casts of patients with unilateral cleft lip and palate.

Cleft Palate Craniofac J 2012 Jul 20;49(4):477-83. Epub 2011 Mar 20.

Dipartimento di Morfologia Umana e Scienze Biomediche Città Studi, via Mangiagalli 31, I-20133 Milano, Italy.

Objective: To assess a three-dimensional stereophotogrammetric method for palatal cast digitization of children with unilateral cleft lip and palate.

Design: As part of a collaboration between the University of Milan (Italy) and the University CES of Medellin (Colombia), 96 palatal cast models obtained from neonatal patients with unilateral cleft lip and palate were obtained and digitized using a three-dimensional stereophotogrammetric imaging system.

Main Outcome Measures: Three-dimensional measurements (cleft width, depth, length) were made separately for the longer and shorter cleft segments on the digital dental cast surface between landmarks, previously marked. Seven linear measurements were computed. Systematic and random errors between operators' tracings, and accuracy on geometric objects of known size were calculated. In addition, mean measurements from three-dimensional stereophotographs were compared statistically with those from direct anthropometry.

Results: The three-dimensional method presented good accuracy error (<0.9%) on measuring geometric objects. No systematic errors between operators' measurements were found (p > .05). Statistically significant differences (p < 5%) were noted for different methods (caliper versus stereophotogrammetry) for almost all distances analyzed, with mean absolute difference values ranging between 0.22 and 3.41 mm. Therefore, rates for the technical error of measurement and relative error magnitude were scored as moderate for Ag-Am and poor for Ag-Pg and Am-Pm distances. Generally, caliper values were larger than three-dimensional stereophotogrammetric values.

Conclusions: Three-dimensional stereophotogrammetric systems have some advantages over direct anthropometry, and therefore the method could be sufficiently precise and accurate on palatal cast digitization with unilateral cleft lip and palate. This would be useful for clinical analyses in maxillofacial, plastic, and aesthetic surgery.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1597/10-207DOI Listing
July 2012

Central nervous system-acting drugs influencing hypothalamic-pituitary-adrenal axis function.

Endocr Dev 2010 24;17:108-120. Epub 2009 Nov 24.

The hypothalamic-pituitary-adrenal (HPA) axis is a major integrated system that maintains body homeostasis by regulating the neuroendocrine and sympathetic nervous systems and modulating immune function. It is well established that the central nervous system (CNS) integrates responses to different stimuli secreting a specific corticotropin-releasing hormone (CRH) and vasopressin (AVP). In turn, they stimulate the release of ACTH, which induces steroidogenesis in the adrenal gland. The HPA axis is regulated by diurnal rhythms and negative feedback by corticosteroids. Many neurotransmitters and neuropeptides are responsible for the modulation of CRH and AVP neurons. In addition to synthetic glucocorticoids that inhibit the HPA axis, GABA agonists, opioid peptides and endocannabinoids can inhibit cortisol secretion. On the contrary, serotonin, norepinephrine, dopamine, acetylcholine, ghrelin, angiotensin II and different cytokines can stimulate it. It follows that a number of neuroactive drugs, acting as agonists or antagonists on several brain neurotransmitter or neuropeptide receptors, can influence ACTH/cortisol secretion thereby interfering with clinical testing of the functionality of the HPA axis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1159/000262533DOI Listing
December 2010

Desacyl-ghrelin and synthetic GH-secretagogues modulate the production of inflammatory cytokines in mouse microglia cells stimulated by beta-amyloid fibrils.

J Neurosci Res 2009 Sep;87(12):2718-27

Department of Experimental Medicine, University of Milano-Bicocca, Milan, Italy.

Data from Alzheimer's disease (AD) patients and AD animal models demonstrate the accumulation of inflammatory microglia at sites of insoluble fibrillar beta-amyloid protein (fAbeta) deposition. It is known that fAbeta binds to CD36, a type B scavenger receptor also involved in internalization of oxidized low-density lipoprotein (LDL), and initiate a signaling cascade that regulates microglial recruitment, activation, and secretion of inflammatory mediators leading to neuronal dysfunction and death. The recent demonstration of a binding site for the growth hormone secretagogues (GHS) on CD36 prompted us to ascertain whether ghrelin and synthetic GHS could modulate the synthesis of inflammatory cytokines in fAbeta-activated microglia cells. We demonstrate that N9 microglia cells express the CD36 and are a suitable model to study the activation of inflammatory cytokines synthesis. In fact, in N9 cells exposed to fAbeta(25-35) for 24 hr, the expression of interleukin (IL)-1beta and IL-6 mRNA significantly increased. Interestingly, 10(-7) M desacyl-ghrelin, hexarelin, and EP80317 in the nanomolar range effectively counteracted fAbeta(25-35) stimulation of IL-6 mRNA levels, whereas ghrelin was ineffective. Similarly, the effects of fAbeta(25-35) on IL-1beta mRNA levels were attenuated by desacyl-ghrelin, hexarelin, and EP80317, but not ghrelin. Because we have observed that the specific GHS receptor GHS-R1a is not expressed in N9 cells, the actions of GHS should be mediated by different receptors. Reportedly, hexarelin and EP80317 are capable of binding the CD36 in mouse macrophages and reducing atherosclerotic plaque deposition in mice. We conclude that desacyl-ghrelin, hexarelin, and EP80317 might interfere with fAbeta activation of CD36 in microglia cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jnr.22088DOI Listing
September 2009

Chronic intracerebroventricular injection of TLQP-21 prevents high fat diet induced weight gain in fast weight-gaining mice.

Genes Nutr 2009 Mar 27;4(1):49-57. Epub 2009 Feb 27.

Institute of Neuroscience, CNR, Via del Fosso di Fiorano, 64/65, 00143, Rome, Italy,

The vgf gene regulates energy homeostasis and the VGF-derived peptide TLQP-21 centrally exerts catabolic effects in mice and hamsters. Here, we investigate the effect of chronic intracerebroventricular (icv) injection of TLQP-21 in mice fed high fat diet (HFD). Fast weight-gaining mice injected with the peptide or cerebrospinal fluid were selected for physiological, endocrine, and molecular analysis. TLQP-21 selectively inhibited the increase in body weight and epididymal white adipose tissue (eWAT) weight induced by HFD in control animals despite both groups having a similar degree of hyperphagia. TLQP-21 normalized the increase in leptin and decrease in ghrelin while increasing epinephrine and epinephrine/norepinephrine ratio when compared to values in controls. Finally, HFD-TLQP-21 mice showed a selective increase of eWAT beta3-adrenergic receptor mRNA. Peroxisome-proliferator-activated-receptor-delta and hormone-sensing-lipase mRNA were also upregulated. In conclusion, chronic icv infusion of TLQP-21 prevented the early phase of diet-induced obesity despite overfeeding. These effects were paralleled by activation of catabolic pathways within the eWAT. Our results further support a role for TLQP-21 as a catabolic neuropeptide.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12263-009-0110-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2654049PMC
March 2009

Hexarelin modulates the expression of growth hormone secretagogue receptor type 1a mRNA at hypothalamic and pituitary sites.

Neuroendocrinology 2004 10;80(1):52-9. Epub 2004 Sep 10.

Department of Experimental and Environmental Medicine and Biotechnology, University of Milano-Bicocca, Monza, Italy.

Ghrelin and the synthetic growth hormone secretagogues (GHSs) activate a G-protein-coupled receptor (GHS-R) originally cloned from the pituitary, but which is also expressed in the hypothalamus, in other areas of the brain and in numerous peripheral tissues. Several studies have shown that growth hormone (GH)-releasing hormone (GHRH) is necessary for GHSs to exert maximal GH release in vivo. The exact mechanism of this synergism is not clear. Previous data suggest that GHSs can affect pituitary GHS-R mRNA expression; however, it is unknown whether this effect is age dependent and whether hypothalamic GHS-Rs are also affected. In this study, we tested whether (a) the synthetic GHS hexarelin regulates mRNA expression of its own receptor at the pituitary and/or hypothalamus and whether this effect is age dependent, and (b) whether short-term treatment with GHRH or, conversely, passive immunization against GHRH affects pituitary GHS-R1a mRNA expression in infant (10 days old) and young adult rats. GHS-R1a mRNA expression was measured with competitive reverse transcriptase-polymerase chain reaction. Hexarelin treatment significantly increased pituitary and hypothalamic GHS-R1a mRNA levels in normal infant rats, but not in normal young adult rats. In addition, hexarelin administration also stimulated pituitary GHS-R1a mRNA in infant as well as in young adult rats passively immunized against GHRH. GHRH treatment significantly enhanced pituitary GHS-R1a mRNA expression in GHRH-deprived young adult rats, though it did not affect the basal levels of GHS-R1a mRNA in normal infant and adult rats. These data further support the hypothesis that GHRH can affect GHS-R1a expression and that hexarelin upregulates the expression of its own receptor at the pituitary as well as the hypothalamus in an age-dependent fashion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1159/000080793DOI Listing
December 2004

Ghrelin plays a minor role in the physiological control of cardiac function in the rat.

Endocrinology 2003 May;144(5):1787-92

Department of Experimental and Environmental Medicine and Biotechnology, University of Milano-Bicocca, 20052 Monza, Italy.

We have previously reported that a 7-d pretreatment with hexarelin, a synthetic ligand of the GH secretagogue receptor (GHS-R), largely prevented damages induced by ischemia and reperfusion in isolated rat hearts. Our aim was to ascertain whether ghrelin, an endogenous ligand of the GHS-R, is physiologically endowed with cardioprotective activity. Hypophysectomized rats were treated in vivo for 7 d with either ghrelin (320 microg/kg) or hexarelin (80 microg/kg), and their hearts were subjected in vitro to the ischemia and reperfusion procedure. Ghrelin was far less effective than hexarelin in preventing increases in left ventricular end-diastolic pressure (15% and 60% protection for ghrelin and hexarelin, respectively), coronary perfusion pressure (10% and 45% reduction), and release of creatine kinase in the heart perfusate (15% and 55% reduction). In the second experiment, normal rats were passively immunized against ghrelin for 21 d before the ischemia and reperfusion procedure. In these isolated hearts, the ischemia-reperfusion damage was not significantly increased compared with control rats. After hypophysectomy, CD36 mRNA levels significantly increased, whereas those of atrial natriuretic factor significantly decreased. We conclude that: 1) ghrelin plays a minor role in the control of heart function; and 2) hexarelin effects are mediated in part by the GHS-R and largely by interactions with the CD36.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1210/en.2002-221048DOI Listing
May 2003

Ontogeny and tissue-specific regulation of ghrelin mRNA expression suggest that ghrelin is primarily involved in the control of extraendocrine functions in the rat.

Neuroendocrinology 2003 Feb;77(2):91-9

Department of Experimental and Environmental Medicine and Biotechnologies, University of Milano-Bicocca, Milano, Italy.

Ghrelin is a 28-amino-acid gastric peptide that potently stimulates growth hormone (GH) secretion in vivo and in vitro. Ghrelin-expressing cells have been found in the oxyntic region of the stomach and in the arcuate nucleus of the hypothalamus. The aim of this work was to investigate the regional distribution and developmental changes in ghrelin mRNA levels in the pituitary, hypothalamus and gastrointestinal (GI) tract of the rat using a semiquantitative RT-PCR assay. We also describe the effects of ghrelin immunoneutralization in late gestation and those resulting from induction of an isolated GH deficiency in adult rats. Ghrelin mRNA was already expressed in the fetus by embryonic day 12 (E12), by E17 most of ghrelin mRNA was in the trunk. At E17, in situ hybridization did not reveal a clear expression of ghrelin mRNA in fetal stomach but showed high ghrelin mRNA levels in the placenta. In the pituitary gland, levels of ghrelin mRNA were high after birth but declined significantly with puberty, whereas in the hypothalamus they were barely detectable at birth and remained very low at all subsequent time points tested. In the GI tract, ghrelin mRNA levels were high from birth to 270 days of life. Immunoneutralization of ghrelin at E16 had no effect on survival or development. Rats showed normal somatotropic function, ghrelin expression and onset of puberty. In young adult rats, passive immunization against GHRH did not affect ghrelin mRNA levels in the pituitary, hypothalamus and stomach. Only a 72-hour fasting period induced a significant increase in ghrelin mRNA levels in the stomach, but not in the pituitary and hypothalamus. These results strongly indicate that ghrelin is an important GI hormone expressed early in life and primarily sensitive to nutritional status.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1159/000068653DOI Listing
February 2003