Publications by authors named "Ibon Garitaonandia"

Article Synopsis
  • Stem cell transplantation is a potential therapy for stroke that could be applied at various times post-stroke, but challenges remain regarding the identification of effective donor stem cells and their mechanisms of action.
  • The study highlights ProtheraCytes, a type of CD34+ cells from human blood and umbilical cords, which have shown promise in a clinical trial and are found to secrete growth factors that aid in blood vessel formation.
  • Experimental results in rats demonstrate that intranasal delivery of ProtheraCytes after a stroke significantly improved recovery and reduced brain damage, with indicators suggesting the role of specific extracellular vesicles (CD63+ EVs) in promoting regeneration and reducing inflammation.
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Stroke is a leading cause of death in the US and around the world but with limited treatment options. Survivors often present with long-term cognitive and neurological deficits. Stem cell-based therapy has emerged as a potential treatment for stroke.

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We have previously shown that intracardiac delivery of autologous CD34 cells after acute myocardial infarction (AMI) is safe and leads to long term improvement. We are now conducting a multicenter, randomized, controlled Phase I/IIb study in post-AMI to investigate the safety and efficacy of intramyocardial injection of expanded autologous CD34 cells (ProtheraCytes) (NCT02669810). Here, we conducted a series of in vitro studies characterizing the growth factor secretion, exosome secretion, gene expression, cell surface markers, differentiation potential, and angiogenic potential of ProtheraCytes clinical batches to develop a potency assay.

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Knee osteoarthritis (OA) is a degenerative joint disease of the knee that results from the progressive loss of articular cartilage. It is most common in the elderly and affects millions of people worldwide, leading to a continuous increase in the number of total knee replacement surgeries. These surgeries improve the patient's physical mobility, but can lead to late infection, loosening of the prosthesis, and persistent pain.

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We aim to study kinetics of anti-SARS-CoV-2 IgG antibody levels in subjects with COVID-19 for up to 11 months and the potential influential factors. The study was a prospective longitudinal study. The analyses were based on 77 serum/plasma samples with a mean of 4 samples per participant (range 1 - 18) in 20 participants with at least one positive Polymerase Chain Reaction testing result from 19 March 2020 up to 10 February 2021.

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International Stem Cell Corporation human parthenogenetic neural stem cells (ISC-hpNSC) have potential therapeutic value for patients suffering from traumatic brain injury (TBI). Here, we demonstrate the behavioral and histological effects of transplanting ISC-hpNSC intracerebrally in an animal model of TBI. : Sprague-Dawley rats underwent a moderate controlled cortical impact TBI surgery.

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We have previously shown that human parthenogenetic stem cells (hpSC) can be chemically directed to differentiate into a homogeneous population of multipotent neural stem cells (hpNSC) that are scalable, cryopreservable, express all the appropriate neural markers, and can be further differentiated into functional dopaminergic neurons. Differentiation of hpSC into hpNSC provides a platform to study the molecular basis of human neural differentiation, to develop cell culture models of neural disease, and to provide neural stem cells for the treatment of neurodegenerative diseases. Additionally, the hpNSC that are generated could serve as a platform for drug discovery and the determination of pharmaceutical-induced neural toxicity.

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In this commentary we discuss International Stem Cell Corporation's (ISCO's) approach to developing a pluripotent stem cell based treatment for Parkinson's disease (PD). In 2016, ISCO received approval to conduct the world's first clinical study of a pluripotent stem cell based therapy for PD. The Australian regulatory agency Therapeutic Goods Administration (TGA) and the Melbourne Health's Human Research Ethics Committee (HREC) independently reviewed ISCO's extensive preclinical data and granted approval for the evaluation of a novel human parthenogenetic derived neural stem cell (NSC) line, ISC-hpNSC, in a PD phase 1 clinical trial ( ClinicalTrials.

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Repair or regeneration of hyaline cartilage in knees, shoulders, intervertebral discs, and other assorted joints is a major therapeutic target. To date, therapeutic strategies utilizing chondrocytes or mesenchymal stem cells are limited by expandability or the generation of mechanically inferior cartilage. Our objective is to generate robust cartilage-specific matrix from human mesenchymal stem cells suitable for further therapeutic development.

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Genomic aberrations have been identified in many human pluripotent stem cell (hPSC) cultures. Commonly observed duplications in portions of chromosomes 12p and 17q have been associated with increases in genetic instability and resistance to apoptosis, respectively. However, the phenotypic consequences related to sporadic mutations have not been evaluated to date.

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Human pluripotent stem cells (PSC) have the potential to revolutionize regenerative medicine. However undifferentiated PSC can form tumors and strict quality control measures and safety studies must be conducted before clinical translation. Here we describe preclinical tumorigenicity and biodistribution safety studies that were required by the US Food and Drug Administration (FDA) and Australian Therapeutic Goods Administration (TGA) prior to conducting a Phase I clinical trial evaluating the safety and tolerability of human parthenogenetic stem cell derived neural stem cells ISC-hpNSC for treating Parkinson's disease (ClinicalTrials.

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Human pluripotent stem cells (hPSCs) have the potential to fundamentally change the way that we go about treating and understanding human disease. Despite this extraordinary potential, these cells also have an innate capability to form tumors in immunocompromised individuals when they are introduced in their pluripotent state. Although current therapeutic strategies involve transplantation of only differentiated hPSC derivatives, there is still a concern that transplanted cell populations could contain a small percentage of cells that are not fully differentiated.

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Cell therapy has attracted considerable interest as a promising therapeutic alternative for patients with Parkinson's disease (PD). Clinical studies have shown that grafted fetal neural tissue can achieve considerable biochemical and clinical improvements in PD. However, the source of fetal tissue grafts is limited and ethically controversial.

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Recent studies indicate that human pluripotent stem cell (PSC)-based therapies hold great promise in Parkinson's disease (PD). Clinical studies have shown that grafted fetal neural tissue can achieve considerable biochemical and clinical improvements in PD. However, the source of fetal tissue grafts is limited and ethically controversial.

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The self-renewal and differentiation capacities of human pluripotent stem cells (hPSCs) make them a promising source of material for cell transplantation therapy, drug development, and studies of cellular differentiation and development. However, the large numbers of cells necessary for many of these applications require extensive expansion of hPSC cultures, a process that has been associated with genetic and epigenetic alterations. We have performed a combinatorial study on both hESCs and hiPSCs to compare the effects of enzymatic vs.

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New small molecules that regulate the step-wise differentiation of human pluripotent stem cells into dopaminergic neurons have been identified. The steroid, guggulsterone, was found to be the most effective inducer of neural stem cells into dopaminergic neurons. These neurons are extensively characterized and shown to be functional.

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Human pluripotent stem cells (hPSCs) are potential sources of cells for modeling disease and development, drug discovery, and regenerative medicine. However, it is important to identify factors that may impact the utility of hPSCs for these applications. In an unbiased analysis of 205 hPSC and 130 somatic samples, we identified hPSC-specific epigenetic and transcriptional aberrations in genes subject to X chromosome inactivation (XCI) and genomic imprinting, which were not corrected during directed differentiation.

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Human parthenogenetic stem cells are derived from the inner cell mass of blastocysts obtained from unfertilized oocytes that have been stimulated to develop without any participation of male gamete. As parthenogenesis does not involve the destruction of a viable human embryo, the derivation and use of human parthenogenetic stem cells does not raise the same ethical concerns as conventional embryonic stem cells. Human parthenogenetic stem cells are similar to embryonic stem cells in their proliferation and multilineage in vitro differentiation capacity.

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Pluripotent stem cells (PSCs) have the unique characteristic that they can differentiate into cells from all three germ layers. This makes them a potentially valuable tool for the treatment of many different diseases. With the advent of induced pluripotent stem cells (iPSCs) and continuing research with human embryonic stem cells (hESCs) there is a need for assays that can demonstrate that a particular cell line is pluripotent.

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Rapid and dependable methods for isolating human pluripotent stem cell (hPSC) populations are urgently needed for quality control in basic research and in cell-based therapy applications. Using lectin arrays, we analyzed glycoproteins extracted from 26 hPSC samples and 22 differentiated cell samples, and identified a small group of lectins with distinctive binding signatures that were sufficient to distinguish hPSCs from a variety of non-pluripotent cell types. These specific biomarkers were shared by all the 12 human embryonic stem cell and the 14 human induced pluripotent stem cell samples examined, regardless of the laboratory of origin, the culture conditions, the somatic cell type reprogrammed, or the reprogramming method used.

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For some highly endangered species there are too few reproductively capable animals to maintain adequate genetic diversity, and extraordinary measures are necessary to prevent extinction. We report generation of induced pluripotent stem cells (iPSCs) from two endangered species: a primate, the drill, Mandrillus leucophaeus and the nearly extinct northern white rhinoceros, Ceratotherium simum cottoni. iPSCs may eventually facilitate reintroduction of genetic material into breeding populations.

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The PAQR family of proteins comprises an intriguing group of newly discovered receptors. Although the agonist is known for 5 of the 11 human PAQRs, most are considered "orphan" receptors. We developed a yeast-based assay system for PAQR receptor activity that can be used to identify agonists for PAQRs of unknown function.

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The progestin and AdipoQ receptor (PAQR) family of proteins comprises three distinct structural classes, each with seemingly different agonist specificities. For example, Class I receptors, like the human adiponectin receptors (AdipoR1 and AdipoR2), sense proteins with a particular three-dimensional fold, while Class II receptors are nonclassical membrane receptors for the steroid hormone progesterone. Using a previously developed heterologous expression system to study PAQR receptor activity, we demonstrate that human PAQRs from all three classes are antagonized by both 1(S),2(R)-d-erythro-2-(N-myristoylamino)-1-phenyl-1-propanol, a ceramidase inhibitor, and TNFalpha, a homologue of adiponectin that functions antagonistically to both adiponectin and progesterone in human cells.

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The Izh2p protein from Saccharomyces cerevisiae belongs to the newly characterized progestin and adipoQ receptor (PAQR) superfamily of receptors whose mechanism of signal transduction is still unknown. Izh2p functions as a receptor for the plant PR-5 defensin osmotin and has pleiotropic effects on cellular biochemistry. One example of this pleiotropy is the Izh2p-dependent repression of FET3, a gene involved in iron-uptake.

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The nuclear progesterone receptor (nPR) mediates many of the physiological effects of progesterone by regulating the expression of genes, however, progesterone also exerts non-transcriptional (non-genomic) effects that have been proposed to rely on a receptor that is distinct from nPR. Several members of the progestin and AdipoQ-Receptor (PAQR) family were recently identified as potential mediators of these non-genomic effects. Membranes from cells expressing these proteins, called mPRalpha, mPRbeta and mPRgamma, were shown to specifically bind progesterone and have G-protein coupled receptor (GPCR) characteristics, although other studies dispute these findings.

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