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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Fibroblasts isolated from chronic wound dressings differentiate chronicity in recessive dystrophic epidermolysis bullosa

2023 , DE GREGORIO CONCHA, CRISTIAN ALEJANDRO , EZQUER, EDUARDO MARCELO , Catalan, E , Palisson, F , South, AP , Fuentes, I

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Maintenance of chronicity signatures in fibroblasts isolated from recessive dystrophic epidermolysis bullosa chronic wound dressings under culture conditions

2023 , DE GREGORIO CONCHA, CRISTIAN ALEJANDRO , Evelyng Catalán , Gabriel Garrido , Pilar Morandé , CASTILLO BENNETT, JIMENA VICTORIA , Catalina Muñoz , Glenda Cofré , HUANG, YA LIN , Bárbara Cuadra , Paola Murgas , Margarita Calvo , Fernando Altermatt , Andrew P. South , YUBERO GONCALVEZ, MARIA JOAO , PALISSON ETCHARREN, FRANCIS , EZQUER, EDUARDO MARCELO , FUENTES BUSTOS, MARIA IGNACIA

Abstract Background Recessive Dystrophic Epidermolysis Bullosa (RDEB) is a rare inherited skin disease caused by variants in the COL7A1 gene, coding for type VII collagen (C7), an important component of anchoring fibrils in the basement membrane of the epidermis. RDEB patients suffer from skin fragility starting with blister formation and evolving into chronic wounds, inflammation and skin fibrosis, with a high risk of developing aggressive skin carcinomas. Restricted therapeutic options are limited by the lack of in vitro models of defective wound healing in RDEB patients. Results In order to explore a more efficient, non-invasive in vitro model for RDEB studies, we obtained patient fibroblasts derived from discarded dressings) and examined their phenotypic features compared with fibroblasts derived from non-injured skin of RDEB and healthy-donor skin biopsies. Our results demonstrate that fibroblasts derived from RDEB chronic wounds (RDEB-CW) displayed characteristics of senescent cells, increased myofibroblast differentiation, and augmented levels of TGF-β1 signaling components compared to fibroblasts derived from RDEB acute wounds and unaffected RDEB skin as well as skin from healthy-donors. Furthermore, RDEB-CW fibroblasts exhibited an increased pattern of inflammatory cytokine secretion (IL-1β and IL-6) when compared with RDEB and control fibroblasts. Interestingly, these aberrant patterns were found specifically in RDEB-CW fibroblasts independent of the culturing method, since fibroblasts obtained from dressing of acute wounds displayed a phenotype more similar to fibroblasts obtained from RDEB normal skin biopsies. Conclusions Our results show that in vitro cultured RDEB-CW fibroblasts maintain distinctive cellular and molecular characteristics resembling the inflammatory and fibrotic microenvironment observed in RDEB patients’ chronic wounds. This work describes a novel, non-invasive and painless strategy to obtain human fibroblasts chronically subjected to an inflammatory and fibrotic environment, supporting their use as an accessible model for in vitro studies of RDEB wound healing pathogenesis. As such, this approach is well suited to testing new therapeutic strategies under controlled laboratory conditions.

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Administration of secretome derived from human mesenchymal stem cells prevents diabetic neuropathy progression in an animal model of type 2 diabetes

2019 , EZQUER, EDUARDO FERNANDO , DE GREGORIO CONCHA, CRISTIAN ALEJANDRO , CONTADOR MARTINEZ, DAVID ERNESTO , Campero, M. , Santapau, D , EZQUER, EDUARDO MARCELO

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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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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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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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Characterization of diabetic neuropathy progression in a mouse model of type 2 diabetes mellitus

2018 , DE GREGORIO CONCHA, CRISTIAN ALEJANDRO , CONTADOR MARTINEZ, DAVID ERNESTO , Mario Campero , EZQUER, EDUARDO MARCELO , EZQUER, EDUARDO FERNANDO

Diabetes mellitus (DM) is one of most frequent chronic diseases with an increasing incidence in most countries. Diabetic neuropathy (DN) is one of the earliest and main complications of diabetic patients, which is characterized by progressive, distal-to-proximal degeneration of peripheral nerves. The cellular and molecular mechanisms that trigger DN are highly complex, heterogeneous and not completely known. Animal models have constituted a valuable tool for understanding diabetes pathophysiology; however, the temporal course of DN progression in animal models of type 2 diabetes (T2DM) is not completely understood. In this work, we characterized the onset and progression of DN in BKS db/db mice, including the main functional and histological features observed in the human disease. We demonstrated that diabetic animals display a progressive sensory loss and electrophysiological impairments in early-to-mid phases of disease. Furthermore, we detected an early decrease in intraepidermal nerve fibers (IENF) density in 18-week-old diabetic mice, which is highly associated with sensory loss and constitutes a reliable marker of DN. Other common histological parameters of DN, like Schwann cells apoptosis and infiltration of CD3+ cells in the sciatic nerve, were altered in mid-to-late phases of disease. Our results support the general consensus that DN evolves from initial functional to late structural changes. This work aimed to characterize the progression of DN in a reliable animal model sharing the main human disease features, which is necessary to assess new therapies for this complex disease. Finally, we also aimed to identify an effective temporal window where these potential treatments could be successfully applied.

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Sensory neuron cultures derived from adult db/db mice as a simplified model to study type-2 diabetes-associated axonal regeneration defects

2021 , DE GREGORIO CONCHA, CRISTIAN ALEJANDRO , EZQUER, EDUARDO FERNANDO

ABSTRACT Diabetic neuropathy (DN) is an early common complication of diabetes mellitus (DM), leading to chronic pain, sensory loss and muscle atrophy. Owing to its multifactorial etiology, neuron in vitro cultures have been proposed as simplified systems for DN studies. However, the most used models currently available do not recreate the chronic and systemic damage suffered by peripheral neurons of type-2 DM (T2DM) individuals. Here, we cultured neurons derived from dorsal root ganglia from 6-month-old diabetic db/db-mice, and evaluated their morphology by the Sholl method as an easy-to-analyze readout of neuronal function. We showed that neurons obtained from diabetic mice exhibited neuritic regeneration defects in basal culture conditions, compared to neurons from non-diabetic mice. Next, we evaluated the morphological response to common neuritogenic factors, including nerve growth factor NGF and Laminin-1 (also called Laminin-111). Neurons derived from diabetic mice exhibited reduced regenerative responses to these factors compared to neurons from non-diabetic mice. Finally, we analyzed the neuronal response to a putative DN therapy based on the secretome of mesenchymal stem cells (MSC). Neurons from diabetic mice treated with the MSC secretome displayed a significant improvement in neuritic regeneration, but still reduced when compared to neurons derived from non-diabetic mice. This in vitro model recapitulates many alterations observed in sensory neurons of T2DM individuals, suggesting the possibility of studying neuronal functions without the need of adding additional toxic factors to culture plates. This model may be useful for evaluating intrinsic neuronal responses in a cell-autonomous manner, and as a throughput screening for the pre-evaluation of new therapies for DN.

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Fibroblasts isolated from chronic wound dressings differentiate chronicity in recessive dystrophic epidermolysis bullosa

2023 , DE GREGORIO CONCHA, CRISTIAN ALEJANDRO , EZQUER, EDUARDO MARCELO , F. Palisson , E. Catalán , A.P. South , FUENTES BUSTOS, MARIA IGNACIA

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The Role of Schwann Cells in Peripheral Nerve Function, Injury, and Repair

2020-05 , SCHUH, CHRISTINA , DE GREGORIO CONCHA, CRISTIAN ALEJANDRO , Pamina Contreras-kallens

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