DE GREGORIO CONCHA, CRISTIAN ALEJANDRO
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DE GREGORIO CONCHA, CRISTIAN ALEJANDRO
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crdegregorio@udd.cl
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57193329776

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Amelioration of morphine withdrawal syndrome by systemic and intranasal administration of mesenchymal stem cell‐derived secretome in preclinical models of morphine dependence

2023 , Mauricio Quezada , Carolina Ponce , Pablo Berríos‐Cárcamo , Daniela Santapau , Javiera Gallardo , DE GREGORIO CONCHA, CRISTIAN ALEJANDRO , María Elena Quintanilla , Paola Morales , Mario Herrera‐Marschitz , EZQUER, EDUARDO MARCELO , Yedy Israel , Paula Andrés‐Herrera , Lucia Hipólito , EZQUER, EDUARDO FERNANDO

AbstractBackgroundMorphine is an opiate commonly used in the treatment of moderate to severe pain. However, prolonged administration can lead to physical dependence and strong withdrawal symptoms upon cessation of morphine use. These symptoms can include anxiety, irritability, increased heart rate, and muscle cramps, which strongly promote morphine use relapse. The morphine‐induced increases in neuroinflammation, brain oxidative stress, and alteration of glutamate levels in the hippocampus and nucleus accumbens have been associated with morphine dependence and a higher severity of withdrawal symptoms. Due to its rich content in potent anti‐inflammatory and antioxidant factors, secretome derived from human mesenchymal stem cells (hMSCs) is proposed as a preclinical therapeutic tool for the treatment of this complex neurological condition associated with neuroinflammation and brain oxidative stress.MethodsTwo animal models of morphine dependence were used to evaluate the therapeutic efficacy of hMSC‐derived secretome in reducing morphine withdrawal signs. In the first model, rats were implanted subcutaneously with mini‐pumps which released morphine at a concentration of 10 mg/kg/day for seven days. Three days after pump implantation, animals were treated with a simultaneous intravenous and intranasal administration of hMSC‐derived secretome or vehicle, and withdrawal signs were precipitated on day seven by i.p. naloxone administration. In this model, brain alterations associated with withdrawal were also analyzed before withdrawal precipitation. In the second animal model, rats voluntarily consuming morphine for three weeks were intravenously and intranasally treated with hMSC‐derived secretome or vehicle, and withdrawal signs were induced by morphine deprivation.ResultsIn both animal models secretome administration induced a significant reduction of withdrawal signs, as shown by a reduction in a combined withdrawal score. Secretome administration also promoted a reduction in morphine‐induced neuroinflammation in the hippocampus and nucleus accumbens, while no changes were observed in extracellular glutamate levels in the nucleus accumbens.ConclusionData presented from two animal models of morphine dependence suggest that administration of secretome derived from hMSCs reduces the development of opioid withdrawal signs, which correlates with a reduction in neuroinflammation in the hippocampus and nucleus accumbens.

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Characterisation of an animal model of type 2 diabetes with potential application in the evaluation of new therapies for diabetic neuropathy

2018 , EZQUER, EDUARDO MARCELO , DE GREGORIO CONCHA, CRISTIAN ALEJANDRO , CONTADOR MARTINEZ, DAVID ERNESTO , Daniela Santapau , Campero, M

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Human adipose-derived mesenchymal stem cell-conditioned medium ameliorates polyneuropathy and foot ulceration in diabetic BKS db/db mice

2020 , DE GREGORIO CONCHA, CRISTIAN ALEJANDRO , CONTADOR MARTINEZ, DAVID ERNESTO , Cristian Acosta , Diego Díaz , Constanza Cárcamo , Daniela Santapau , Lorena Lobos-Gonzalez , Mario Campero , Daniel Carpio , Caterina Gabriele , Marco Gaspari , Victor Aliaga-Tobar , Vinicius Maracaja-Coutinho , EZQUER, EDUARDO MARCELO , EZQUER, EDUARDO FERNANDO

Abstract Background Diabetic polyneuropathy (DPN) is the most common and early developing complication of diabetes mellitus, and the key contributor for foot ulcers development, with no specific therapies available. Different studies have shown that mesenchymal stem cell (MSC) administration is able to ameliorate DPN; however, limited cell survival and safety reasons hinder its transfer from bench to bedside. MSCs secrete a broad range of antioxidant, neuroprotective, angiogenic, and immunomodulatory factors (known as conditioned medium), which are all decreased in the peripheral nerves of diabetic patients. Furthermore, the abundance of these factors can be boosted in vitro by incubating MSCs with a preconditioning stimulus, enhancing their therapeutic efficacy. We hypothesize that systemic administration of conditioned medium derived from preconditioned MSCs could reverse DPN and prevent foot ulcer formation in a mouse model of type II diabetes mellitus. Methods Diabetic BKS db/db mice were treated with systemic administration of conditioned medium derived from preconditioned human MSCs; conditioned medium derived from non-preconditioned MSCs or vehicle after behavioral signs of DPN was already present. Conditioned medium or vehicle administration was repeated every 2 weeks for a total of four administrations, and several functional and structural parameters characteristic of DPN were evaluated. Finally, a wound was made in the dorsal surface of both feet, and the kinetics of wound closure, re-epithelialization, angiogenesis, and cell proliferation were evaluated. Results Our molecular, electrophysiological, and histological analysis demonstrated that the administration of conditioned medium derived from non-preconditioned MSCs or from preconditioned MSCs to diabetic BKS db/db mice strongly reverts the established DPN, improving thermal and mechanical sensitivity, restoring intraepidermal nerve fiber density, reducing neuron and Schwann cell apoptosis, improving angiogenesis, and reducing chronic inflammation of peripheral nerves. Furthermore, DPN reversion induced by conditioned medium administration enhances the wound healing process by accelerating wound closure, improving the re-epithelialization of the injured skin and increasing blood vessels in the wound bed in a skin injury model that mimics a foot ulcer. Conclusions Studies conducted indicate that MSC-conditioned medium administration could be a novel cell-free therapeutic approach to reverse the initial stages of DPN, avoiding the risk of lower limb amputation triggered by foot ulcer formation and accelerating the wound healing process in case it occurs.

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A Novel Morphine Drinking Model of Opioid Dependence in Rats

2022 , BERRIOS CARCAMO, PABLO ANDRES , Mauricio Quezada , Daniela Santapau , Paola Morales , OLIVARES, MARIA BELEN , Carolina Ponce , Alba Ávila , María Elena Quintanilla , EZQUER, EDUARDO MARCELO , DE GREGORIO CONCHA, CRISTIAN ALEJANDRO , Mario Herrera-Marschitz , Yedy Israel , EZQUER, EDUARDO FERNANDO

An animal model of voluntary oral morphine consumption would allow for a pre-clinical evaluation of new treatments aimed at reducing opioid intake in humans. However, the main limitation of oral morphine consumption in rodents is its bitter taste, which is strongly aversive. Taste aversion is often overcome by the use of adulterants, such as sweeteners, to conceal morphine taste or bitterants in the alternative bottle to equalize aversion. However, the adulterants’ presence is the cause for consumption choice and, upon removal, the preference for morphine is not preserved. Thus, current animal models are not suitable to study treatments aimed at reducing consumption elicited by morphine itself. Since taste preference is a learned behavior, just-weaned rats were trained to accept a bitter taste, adding the bitterant quinine to their drinking water for one week. The latter was followed by allowing the choice of quinine or morphine (0.15 mg/mL) solutions for two weeks. Then, quinine was removed, and the preference for morphine against water was evaluated. Using this paradigm, we show that rats highly preferred the consumption of morphine over water, reaching a voluntary morphine intake of 15 mg/kg/day. Morphine consumption led to significant analgesia and hyperlocomotion, and to a marked deprivation syndrome following the administration of the opioid antagonist naloxone. Voluntary morphine consumption was also shown to generate brain oxidative stress and neuroinflammation, signs associated with opioid dependence development. We present a robust two-bottle choice animal model of oral morphine self-administration for the evaluation of therapeutic interventions for the treatment of morphine dependence.

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Methadone directly impairs central nervous system cells in vitro

2024 , Cristian De Gregorio , Javiera Gallardo , BERRIOS CARCAMO, PABLO ANDRES , Álex Handy , Daniela Santapau , ANTONIA GONZALEZ MADRID , EZQUER, EDUARDO MARCELO , Paola Morales , Alejandro Luarte , Daniela Corvalán , Úrsula Wyneken , EZQUER, EDUARDO FERNANDO

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