Stem cell secretome treatment improves whole-body metabolism, reduces adiposity, and promotes skeletal muscle function in aged mice.

Aging coincides with the progressive loss of muscle mass and strength, increased adiposity, and diminished physical function. Accordingly, interventions aimed at improving muscle, metabolic, and/or physical health are of interest to mitigate the adverse effects of aging. In this study, we tested a stem cell secretome product, which contains extracellular vesicles and growth, cytoskeletal remodeling, and immunomodulatory factors.

Autologous dendritic cells loaded with antigens from self-renewing autologous tumor cells as patient-specific therapeutic cancer vaccines.

A promising personal immunotherapy is autologous dendritic cells (DC) loaded with autologous tumor antigens (ATA) derived from self-renewing autologous cancer cells. DC-ATA are suspended in granulocyte-macrophage colony stimulating factor at the time of each subcutaneous injection. Previously, irradiated autologous tumor cell vaccines have produced encouraging results in 150 cancer patients, but the DC-ATA vaccine demonstrated superiority in single-arm and randomized trials in metastatic melanoma.

Phase 2 study of AV-GBM-1 (a tumor-initiating cell targeted dendritic cell vaccine) in newly diagnosed Glioblastoma patients: safety and efficacy assessment.

Background: Vaccine immunotherapy may improve survival in Glioblastoma (GBM). A multicenter phase II trial was designed to determine: (1) the success rate of manufacturing the Aivita GBM vaccine (AV-GBM-1), (2) Adverse Events (AE) associated with AV-GBM-1 administration, and (3) survival.

Methods: Fresh suspected glioblastoma tissue was collected during surgery, and patients with pathology-confirmed GBM enrolled before starting concurrent Radiation Therapy and Temozolomide (RT/TMZ) with Intent to Treat (ITT) after recovery from RT/TMZ.

A personal COVID-19 dendritic cell vaccine made at point-of-care: Feasibility, safety, and antigen-specific cellular immune responses.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a world-wide pandemic. Internationally, because of availability, accessibility, and distribution issues, there is a need for additional vaccines. This study aimed to: establish the feasibility of personal dendritic cell vaccines to the SARS-CoV-2 spike protein, establish the safety of a single subcutaneous vaccine injection, and determine the antigen-specific immune response following vaccination.

Retinal Organoids Long-Term Functional Characterization Using Two-Photon Fluorescence Lifetime and Hyperspectral Microscopy.

Pluripotent stem cell-derived organoid technologies have opened avenues to preclinical basic science research, drug discovery, and transplantation therapy in organ systems. Stem cell-derived organoids follow a time course similar to species-specific organ gestation . However, heterogeneous tissue yields, and subjective tissue selection reduce the repeatability of organoid-based scientific experiments and clinical studies.

Co-grafts of Human Embryonic Stem Cell Derived Retina Organoids and Retinal Pigment Epithelium for Retinal Reconstruction in Immunodeficient Retinal Degenerate Royal College of Surgeons Rats.

End-stage age-related macular degeneration (AMD) and retinitis pigmentosa (RP) are two major retinal degenerative (RD) conditions that result in irreversible vision loss. Permanent eye damage can also occur in battlefields or due to accidents. This suggests there is an unmet need for developing effective strategies for treating permanent retinal damages.

Retinal organoids on-a-chip: a micro-millifluidic bioreactor for long-term organoid maintenance.

Retinal degeneration is a leading cause of vision impairment and blindness worldwide and medical care for advanced disease does not exist. Stem cell-derived retinal organoids (RtOgs) became an emerging tool for tissue replacement therapy. However, existing RtOg production methods are highly heterogeneous.

Retina Organoid Transplants Develop Photoreceptors and Improve Visual Function in RCS Rats With RPE Dysfunction.

Purpose: To study if human embryonic stem cell-derived photoreceptors could survive and function without the support of retinal pigment epithelium (RPE) after transplantation into Royal College of Surgeons rats, a rat model of retinal degeneration caused by RPE dysfunction.

Methods: CSC14 human embryonic stem cells were differentiated into primordial eye structures called retinal organoids. Retinal organoids were analyzed by quantitative PCR and immunofluorescence and compared with human fetal retina.

Preliminary observations on soluble programmed cell death protein-1 as a prognostic and predictive biomarker in patients with metastatic melanoma treated with patient-specific autologous vaccines.

Because of its role as an immune checkpoint, levels of soluble programmed cell death protein-1 (sPD-1) could be useful as a prognostic biomarker or predictive biomarker in cancer patients treated with vaccines. Very low levels of sPD-1 may indicate lack of an existing anti-cancer immune response; very high levels may indicate an active immune response that is suppressed. In between these extremes, a decrease in PD-1 following injections of an anti-cancer vaccine may indicate an enhanced immune response that has not been suppressed.

Transplanted hESC-Derived Retina Organoid Sheets Differentiate, Integrate, and Improve Visual Function in Retinal Degenerate Rats.

Purpose: To investigate whether sheets of retina organoids derived from human embryonic stem cells (hESCs) can differentiate, integrate, and improve visual function in an immunodeficient rat model of severe retinal degeneration (RD).

Methods: 3D hESC-derived retina organoids were analyzed by quantitative PCR and immunofluorescence. Sheets dissected from retina organoids (30-65 days of differentiation) were transplanted into the subretinal space of immunodeficient rho S334ter-3 rats.

Human Stem Cell-Derived Skin Progenitors Produce Alpha 2-HS Glycoprotein (Fetuin): A Revolutionary Cosmetic Ingredient.

These studies were designed to determine the effect of stem cell-derived skin lineage precursor secretions on the intrinsic and extrinsic symptoms of human skin aging.
Human stem cells cultivated in balanced conditions were differentiated into skin lineage precursors, and shown to secrete large amounts of fetuin as well as multiple growth factors beneficial for human skin development and maintenance. The cell secretions were incorporated in two simple cosmetic formulations (serum and lotion) and investigated in an IRB-approved 12-week human trial that included 25 subjects in each group.

A new immunodeficient pigmented retinal degenerate rat strain to study transplantation of human cells without immunosuppression.

Purpose: The goal of this study was to develop an immunodeficient rat model of retinal degeneration (RD nude rats) that will not reject transplanted human cells.

Methods: SD-Tg(S334ter)3Lav females homozygous for a mutated mouse rhodopsin transgene were mated with NTac:NIH-Whn (NIH nude) males homozygous for the Foxn1 (rnu) allele. Through selective breeding, a new stock, SD-Foxn1 Tg(S334ter)3Lav (RD nude) was generated such that all animals were homozygous for the Foxn1 (rnu) allele and either homo- or hemizygous for the S334ter transgene.

PTEN inhibition enhances neurite outgrowth in human embryonic stem cell-derived neuronal progenitor cells.

We investigated the role of PTEN (phosphatase and tensin homolog deleted on chromosome 10) during neurite outgrowth of human embryonic stem cell (hESC)-derived neuronal progenitors. PTEN inhibits phosphoinositide 3-kinase (PI3K)/Akt signaling, a common and central outgrowth and survival pathway downstream of neuronal growth factors. It is known that PTEN inhibition, by either polymorphic mutation or gene deletion, can lead to the development of tumorigenesis (Stambolic et al.

Immunological demyelination triggers macrophage/microglial cells activation without inducing astrogliosis.

The glial scar formed by reactive astrocytes and axon growth inhibitors associated with myelin play important roles in the failure of axonal regeneration following central nervous system (CNS) injury. Our laboratory has previously demonstrated that immunological demyelination of the CNS facilitates regeneration of severed axons following spinal cord injury. In the present study, we evaluate whether immunological demyelination is accompanied with astrogliosis.

Stem cell based strategies for spinal cord injury repair.

As our understanding and ability to direct the differentiation of stem cells grows, specific targets and strategies to incorporate them are essential to define. Any cell-based transplantation strategy is fundamentally a combination therapy as either phenotypic or trophic mechanisms may contribute to functional recovery of the injured spinal cord. Both the transplant population as well as the recipient site will guide the growth factor expression profile and the phenotype of the transplanted cells.

Stem cell-based treatments for spinal cord injury.

Cell replacement strategies hold great promise for the treatment of central nervous system injuries and degenerative diseases. The advancement of stem cell therapies has proven to be a viable therapeutic approach to limit secondary degeneration and restore neuronal circuitry at the site of injury. Cell replacement strategies confer phenotype-specific and neurotrophic benefits to the surrounding tissue; however, the mechanisms of transplant-mediated repair are unique to each transplant population.

Recurrent variations in DNA methylation in human pluripotent stem cells and their differentiated derivatives.

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.

Immunological demyelination enhances nerve regeneration after acute transection injury in the adult rat sciatic nerve.

Introduction: Our recent experiments demonstrate that demyelination enhances peripheral nerve regeneration after contusion injury in the adult rat sciatic nerve. The role of demyelination in peripheral nerve regeneration in a sciatic nerve transection model has yet to be elucidated. We hypothesize that (1) axon regeneration within a region of injury increases after experimental, immunologic demyelination, and (2) regenerated axons are partially derived from the proximal motor axons.

Human motor neuron progenitor transplantation leads to endogenous neuronal sparing in 3 models of motor neuron loss.

Motor neuron loss is characteristic of many neurodegenerative disorders and results in rapid loss of muscle control, paralysis, and eventual death in severe cases. In order to investigate the neurotrophic effects of a motor neuron lineage graft, we transplanted human embryonic stem cell-derived motor neuron progenitors (hMNPs) and examined their histopathological effect in three animal models of motor neuron loss. Specifically, we transplanted hMNPs into rodent models of SMA (Δ7SMN), ALS (SOD1 G93A), and spinal cord injury (SCI).

Derivation of high purity neuronal progenitors from human embryonic stem cells.

The availability of human neuronal progenitors (hNPs) in high purity would greatly facilitate neuronal drug discovery and developmental studies, as well as cell replacement strategies for neurodegenerative diseases and conditions, such as spinal cord injury, stroke, Parkinson's disease, Alzheimer's disease, and Huntington's disease. Here we describe for the first time a method for producing hNPs in large quantity and high purity from human embryonic stem cells (hESCs) in feeder-free conditions, without the use of exogenous noggin, sonic hedgehog or analogs, rendering the process clinically compliant. The resulting population displays characteristic neuronal-specific markers.

Equivalence of conventionally-derived and parthenote-derived human embryonic stem cells.

Background: As human embryonic stem cell (hESC) lines can be derived via multiple means, it is important to determine particular characteristics of individual lines that may dictate the applications to which they are best suited. The objective of this work was to determine points of equivalence and differences between conventionally-derived hESC and parthenote-derived hESC lines (phESC) in the undifferentiated state and during neural differentiation.

Methodology/principal Findings: hESC and phESC were exposed to the same expansion conditions and subsequent neural and retinal pigmented epithelium (RPE) differentiation protocols.

Improvement of peripheral nerve regeneration following immunological demyelination in vivo.

Background: To improve regeneration of the peripheral nervous system, a therapy was utilized in the adult rat sciatic nerve in which nerve regeneration is enhanced following acute crush injury. The authors hypothesized that (1) axon regeneration within a region of injury increases following experimental, immunological demyelination; and (2) regenerated axons partially derive from the proximal motor axons.

Methods: The sciatic nerves of 10 Sprague-Dawley rats were injected with a demyelinating agent following crush injury, while the nerves of 10 control rats received a crush injury without therapy.

Dynamic changes in the copy number of pluripotency and cell proliferation genes in human ESCs and iPSCs during reprogramming and time in culture.

Genomic stability is critical for the clinical use of human embryonic and induced pluripotent stem cells. We performed high-resolution SNP (single-nucleotide polymorphism) analysis on 186 pluripotent and 119 nonpluripotent samples. We report a higher frequency of subchromosomal copy number variations in pluripotent samples compared to nonpluripotent samples, with variations enriched in specific genomic regions.

Stem cell-derived neurotrophic support for the neuromuscular junction in spinal muscular atrophy.

Importance Of The Field: Spinal muscular atrophy (SMA) is a neurodegenerative disease characterized by specific degeneration of α-motor neurons in the spinal cord. The use of cell transplantation to restore lost function through cell replacement or prevent further degeneration of motor neurons and synapses through neurotrophic support heralds tremendous hope in the SMA field.

Areas Covered In This Review: Much research has been carried out in the last decade on the use of embryonic stem cells in cell replacement strategies for various neurodegenerative diseases.