Gene Correction Recovers Phagocytosis in Retinal Pigment Epithelium Derived from Retinitis Pigmentosa-Human-Induced Pluripotent Stem Cells.

Hereditary retinal dystrophies (HRD) represent a significant cause of blindness, affecting mostly retinal pigment epithelium (RPE) and photoreceptors (PRs), and currently suffer from a lack of effective treatments. Highly specialized RPE and PR cells interact mutually in the functional retina, therefore primary HRD affecting one cell type leading to a secondary HRD in the other cells. Phagocytosis is one of the primary functions of the RPE and studies have discovered that mutations in the phagocytosis-associated gene Mer tyrosine kinase receptor () lead to primary RPE dystrophy.

Activation of Neurogenesis in Multipotent Stem Cells Cultured In Vitro and in the Spinal Cord Tissue After Severe Injury by Inhibition of Glycogen Synthase Kinase-3.

The inhibition of glycogen synthase kinase-3 (GSK-3) can induce neurogenesis, and the associated activation of Wnt/β-catenin signaling via GSK-3 inhibition may represent a means to promote motor function recovery following spinal cord injury (SCI) via increased astrocyte migration, reduced astrocyte apoptosis, and enhanced axonal growth. Herein, we assessed the effects of GSK-3 inhibition in vitro on the neurogenesis of ependymal stem/progenitor cells (epSPCs) resident in the mouse spinal cord and of human embryonic stem cell-derived neural progenitors (hESC-NPs) and human-induced pluripotent stem cell-derived neural progenitors (hiPSC-NPs) and in vivo on spinal cord tissue regeneration and motor activity after SCI. We report that the treatment of epSPCs and human pluripotent stem cell-derived neural progenitors (hPSC-NPs) with the GSK-3 inhibitor Ro3303544 activates β-catenin signaling and increases the expression of the bIII-tubulin neuronal marker; furthermore, the differentiation of Ro3303544-treated cells prompted an increase in the number of terminally differentiated neurons.

Assessment of Toxic Effects of Ochratoxin A in Human Embryonic Stem Cells.

Ochratoxin A (OTA) is a mycotoxin produced by different and species, and it is considered a common contaminant in food and animal feed worldwide. On the other hand, human embryonic stem cells (hESCs) have been suggested as a valuable model for evaluating drug embryotoxicity. In this study, we have evaluated potentially toxic effects of OTA in hESCs.

FM19G11 and Ependymal Progenitor/Stem Cell Combinatory Treatment Enhances Neuronal Preservation and Oligodendrogenesis after Severe Spinal Cord Injury.

Spinal cord injury (SCI) suffers from a lack of effective therapeutic strategies. We have previously shown that individual therapeutic strategies, transplantation of ependymal stem/progenitor cells of the spinal cord after injury (epSPCi) or FM19G11 pharmacological treatment, induce moderate functional recovery after SCI. Here, the combination of treatments has been assayed for functional and histological analysis.

hiPSC Disease Modeling of Rare Hereditary Cerebellar Ataxias: Opportunities and Future Challenges.

Cerebellar ataxias are clinically and genetically heterogeneous diseases affecting primary cerebellar cells. The lack of availability of affected tissue from cerebellar ataxias patients is the main obstacle in investigating the pathogenicity of these diseases. The landmark discovery of human-induced pluripotent stem cells (hiPSC) has permitted the derivation of patient-specific cells with an unlimited self-renewing capacity.

Highly Efficient Neural Conversion of Human Pluripotent Stem Cells in Adherent and Animal-Free Conditions.

Neural differentiation of human embryonic stem cells (hESCs) and induced pluripotent stem cells (hiPSCs) can produce a valuable and robust source of human neural cell subtypes, holding great promise for the study of neurogenesis and development, and for treating neurological diseases. However, current hESCs and hiPSCs neural differentiation protocols require either animal factors or embryoid body formation, which decreases efficiency and yield, and strongly limits medical applications. Here we develop a simple, animal-free protocol for neural conversion of both hESCs and hiPSCs in adherent culture conditions.

Connexin 50 modulates Sox2 expression in spinal-cord-derived ependymal stem/progenitor cells.

Ion channels included in the family of Connexins (Cx) have been reported to influence the secondary expansion of traumatic spinal cord injury (SCI) and neuropathic pain following SCI. However, Cxs also contribute to spinal cord neurogenesis during the remyelinating process and functional recovery after SCI. Certain Cxs have been recently related to the control of cell proliferation and the differentiation of neuronal progenitors.

Connexin 50 Expression in Ependymal Stem Progenitor Cells after Spinal Cord Injury Activation.

Ion channels included in the family of Connexins (Cx) help to control cell proliferation and differentiation of neuronal progenitors. Here we explored the role of Connexin 50 (Cx50) in cell fate modulation of adult spinal cord derived neural precursors located in the ependymal canal (epSPC). epSPC from non-injured animals showed high expression levels of Cx50 compared to epSPC from animals with spinal cord injury (SCI) (epSPCi).

Complete rat spinal cord transection as a faithful model of spinal cord injury for translational cell transplantation.

Spinal cord injury (SCI) results in neural loss and consequently motor and sensory impairment below the injury. There are currently no effective therapies for the treatment of traumatic SCI in humans. Various animal models have been developed to mimic human SCI.

Purinergic Receptors in Spinal Cord-Derived Ependymal Stem/Progenitor Cells and Their Potential Role in Cell-Based Therapy for Spinal Cord Injury.

Spinal cord injury (SCI) is a major cause of paralysis with no current therapies. Following SCI, large amounts of ATP and other nucleotides are released by the traumatized tissue leading to the activation of purinergic receptors that, in coordination with growth factors, induce lesion remodeling and repair. We found that adult mammalian ependymal spinal cord-derived stem/progenitor cells (epSPCs) are capable of responding to ATP and other nucleotidic compounds, mainly through the activation of the ionotropic P2X4, P2X7, and the metabotropic P2Y1 and P2Y4 purinergic receptors.

Experimental cell transplantation for traumatic spinal cord injury regeneration: intramedullar or intrathecal administration.

Animal experimentation models are a necessary prerequisite to human trials for the use of regenerative medicine in the treatment of spinal cord injuries. Considerable effort is required for the generation of a consistent and reproducible methodology to incur an injury and evaluate the results. The traumatic contusion model has been accepted as a model that closely mimics a typical human traumatic injury, and here we detail step by step an approach to generate a reproducible lesion in rats.

Methacrylate-endcapped caprolactone and FM19G11 provide a proper niche for spinal cord-derived neural cells.

Spinal cord injury (SCI) is a cause of paralysis. Although some strategies have been proposed to palliate the severity of this condition, so far no effective therapies have been found to reverse it. Recently, we have shown that acute transplantation of ependymal stem/progenitor cells (epSPCs), which are spinal cord-derived neural precursors, rescue lost neurological function after SCI in rodents.

Platelet-rich plasma favors proliferation of canine adipose-derived mesenchymal stem cells in methacrylate-endcapped caprolactone porous scaffold niches.

Osteoarticular pathologies very often require an implementation therapy to favor regeneration processes of bone, cartilage and/or tendons. Clinical approaches performed on osteoarticular complications in dogs constitute an ideal model for human clinical translational applications. The adipose-derived mesenchymal stem cells (ASCs) have already been used to accelerate and facilitate the regenerative process.

The biology of HIFα proteins in cell differentiation and disease.

The biology of the α subunits of the hypoxia-inducible factors (HIFα) has expanded in the past years from their original role in angiogenesis to their nowadays position in the self-renewal and differentiation of stem cells. Hypoxia is a physiological condition in different tissues-including tumors-and, may cause stem cells in the onset of genomic instability, this last associated in the scientific literature with the acquisition of a malignant phenotypes. HIFα proteins have been the subjects of excellent scientific contributions in the past years, providing new paradigms in the biology of these key proteins and their pivotal role in cell homeostasis.

Modulation of hypoxia-inducible factors (HIF) from an integrative pharmacological perspective.

Oxygen homeostasis determines the activity and expression of a multitude of cellular proteins and the interplay of pathways that affect crucial cellular processes for development, physiology, and pathophysiology. Hypoxia-inducible factors (HIFs) are transcription factors that respond to changes in available oxygen in the cellular environment and drives cellular adaptation to such conditions. Selective gene expression under hypoxic conditions is the result of an exquisite regulation of HIF, from the pre-transcriptional stage of the HIF gene to the final transcriptional activity of HIF protein.

FM19G11: A new modulator of HIF that links mTOR activation with the DNA damage checkpoint pathways.

The network consisting of mTOR and p53 pathways is crucial to understanding a wide variety of physiological and pathological events, including cancer and aging. In addition, the HIF1alpha protein, a downstream target of mTOR, is a hallmark of different tumor types and was the desired strategy of many drug discovery efforts. Here we present the novel chemical entity FM19G11, a new modulator of HIF1alpha expression, which was used as a molecular tool to dissect and further characterize the cross-talk between these signaling cascades in human colon carcinoma cell lines.

Transplanted oligodendrocytes and motoneuron progenitors generated from human embryonic stem cells promote locomotor recovery after spinal cord transection.

Human embryonic stem cells (hESC) hold great promise for the treatment of patients with many neurodegenerative diseases particularly those arising from cell loss or neural dysfunction including spinal cord injury. This study evaluates the therapeutic effects of transplanted hESC-derived oligodendrocyte progenitors (OPC) and/or motoneuron progenitors (MP) on axonal remyelination and functional recovery of adult rats after complete spinal cord transection. OPC and/or MP were grafted into the site of injury in the acute phase.

Activated spinal cord ependymal stem cells rescue neurological function.

Spinal cord injury (SCI) is a major cause of paralysis. Currently, there are no effective therapies to reverse this disabling condition. The presence of ependymal stem/progenitor cells (epSPCs) in the adult spinal cord suggests that endogenous stem cell-associated mechanisms might be exploited to repair spinal cord lesions.

Hypoxia causes downregulation of mismatch repair system and genomic instability in stem cells.

The DNA mismatch repair (MMR) system maintains genomic integrity by correcting replication errors: its malfunction causes genomic instability in several tumor types. Hypoxia-inducible factor-1alpha (HIF1alpha), the major regulator of the processes that occur in hypoxia and certain epigenetic events downregulate the expression of MMR genes in cancer cells. However, there is a lack of information regarding MMR regulation and the genetic stability of stem cells under hypoxic conditions.