Stem Cell Regenerative Medicine Research Articles

Abstract 13303: Identification of Critical Six Transcriptional Factors for Reprogramming of Mouse Adipose-Derived Regenerative Cells Toward Cardiomyocytes and Its Therapeutic Effect

Background: Adipose-derived regenerative cells (ADRCs) are promising stem cells for regenerative medicine that are easy to harvest from adipose tissues and can expand in vitro . While ADRCs can differentiate into mesodermal lineage cells including adipocytes, osteocytes, and chondrocytes, little is known about differentiating adult ADRCs into mature cardiomyocytes. Objective: The aim of this study was to explore how to differentiate adult mouse ADRCs into cardiomyocytes efficiently and test their effect on the myocardial infarction mouse model in vivo . Method and Results: We performed differential expression analysis to identify transcriptional factors which were upregulated in developing mice heart (E11.5) compared with ADRCs. We systemically screened the combinations of the required transcription factors in ADRCs derived from αMHC-EGFP reporter mice. Here, we identified the following six genes; Baf60c , Gata4 , Gata6 , Klf15 , Mef2a , Myocd , not more or less, as the best combination to efficiently induce αMHC in ADRCs. Fluorescence-activated cell sorting analysis showed that 3.0±0.61% (n=3) ADRCs were positive for αMHC after introducing these six factors. In addition, quantitative PCR demonstrated that several other marker genes of mature cardiomyocytes, including Actc1 , Tnnt2 , Ttn , Fhod3 , were confirmed to be upregulated by six factors. Immunocytochemical staining showed that most of the induced ADRCs had fibrous conformation of sarcomeric α-actin. Moreover, the gene expression pattern of the cells showed upregulation of genes associated with cardiac muscle cell differentiation. Finally, injection of the induced ADRCs into acute myocardial infarction lesions in vivo resulted in the improvement of survival rate (p=0.028, n=32), fractional shortening (p=0.012, n=7, 15), and the reduction of infarction scar area compared to the injection of ADRCs without induction (p=0.029, n=7). The induced ADRCs could survive in situ and continued to express the cardiac troponin T protein for four weeks after injection. Conclusions: The combination of six transcriptional factors could induce cardiomyocyte-like gene expression patterns on adult ADRCs. The induced ADRCs could have a therapeutic effect on an experimental ischemic heart model in vivo .

Industry Updates from the Field of Stem Cell Research and Regenerative Medicine in September 2021

Latest developments in the field of stem cell research and regenerative medicine compiled from publicly available information and press releases from nonacademic institutions in September 2021.

Pancreatic beta cell neogenesis: Debates and updates

Finding endogenous, renewable sources for insulin-producing beta cells in the adult pancreas is one of the holy grails of stem cell research and regenerative medicine. Through lineage tracing and scRNA-seq approaches, Gribben etal. (2021) have recently reported that Ngn3-expressing ductal cells could serve as progenitors for new beta cells in the adult pancreas.

Industry updates from the field of stem cell research and regenerative medicine in July 2021.

Latest developments in the field of stem cell research and regenerative medicine compiled from publicly available information and press releases from nonacademic institutions in July 2021.

Industry Updates From the Field of Stem Cell Research and Regenerative Medicine in August 2021

Latest developments in the field of stem cell research and regenerative medicine compiled from publicly available information and press releases from nonacademic institutions in August 2021.

Antiviral treatment causes a unique mutational signature in cancers of transplantation recipients

SummaryGenetic instability is a major concern for successful application of stem cells in regenerative medicine. However, the mutational consequences of the most applied stem cell therapy in humans, hematopoietic stem cell transplantation (HSCT), remain unknown. Here we characterized the mutation burden of hematopoietic stem and progenitor cells (HSPCs) of human HSCT recipients and their donors using whole-genome sequencing. We demonstrate that the majority of transplanted HSPCs did not display altered mutation accumulation. However, in some HSCT recipients, we identified multiple HSPCs with an increased mutation burden after transplantation. This increase could be attributed to a unique mutational signature caused by the antiviral drug ganciclovir. Using a machine learning approach, we detected this signature in cancer genomes of individuals who received HSCT or solid organ transplantation earlier in life. Antiviral treatment with nucleoside analogs can cause enhanced mutagenicity in transplant recipients, which may ultimately contribute to therapy-related carcinogenesis.

Generation of a control human induced pluripotent stem cell line using the defective and persistent Sendai virus vector system

The defective and persistent Sendai virus (SeVdp) vector system allows efficient generation of transgene-free induced pluripotent stem cells (iPSCs) from human somatic cells. By leveraging the system, here we report the generation of an iPSC line from somatic fibroblasts of a healthy control donner (female), named KEIOi002-A (also named YG-iPS). The control iPSC line would be a useful resource for stem cell research and regenerative medicine.

An overview of mesenchymal stem cells and their potential therapeutic benefits in cancer therapy (Review)

There has been increased interest in using stem cells for regenerative medicine and cancer therapy in the past decade. Mesenchymal stem cells (MSCs) are among the most studied stem cells due to their unique characteristics, such as self-renewal and developmental potency to differentiate into numerous cell types. MSC use has fewer ethical challenges compared with other types of stem cells. Although a number of studies have reported the beneficial effects of MSC-based therapies in treating various diseases, their contribution to cancer therapy remains controversial. The behaviour of MSCs is determined by the interaction between intrinsic transcriptional genes and extrinsic environmental factors. Numerous studies continue to emerge, as there is no denying the potential of MSCs to treat a wide variety of human afflictions. Therefore, the present review article provided an overview of MSCs and their differences compared with embryonic stem cells, and described the molecular mechanisms involved in maintaining their stemness. In addition, the article examined the therapeutic application of stem cells in the field of cancer. The present article also discussed the current divergent roles of MSCs in cancer therapy and the future potential in this field.

An In Vitro and In Vivo Comparison of Osteogenic Differentiation of Human Mesenchymal Stromal/Stem Cells.

The use of stem cells in regenerative medicine, including tissue engineering and transplantation, has generated a great deal of enthusiasm. Mesenchymal stromal/stem cells (MSCs) can be isolated from various tissues, most commonly, bone marrow but more recently adipose tissue, dental pulp, and Wharton's jelly, to name a few. MSCs display varying phenotypic profiles and osteogenic differentiating capacity depending and their site of origin. MSCs have been successfully differentiated into osteoblasts both in vitro an in vivo but discrepancies exist when the two are compared: what happens in vitro does not necessarily happen in vivo, and it is therefore important to understand why these differences occur. The osteogenic process is a complex network of transcription factors, stimulators, inhibitors, proteins, etc., and in vivo experiments are helpful in evaluating the various aspects of this osteogenic process without distractions and confounding variables. With that in mind, the results of in vitro experiments need to be carefully considered and interpreted with caution as they do not perfectly replicate the conditions found within living organisms. This is where in vivo experiments help us better understand interactions that might occur in the osteogenic process that cannot be replicated in vitro. Potentially, these differences could also be exploited to develop an optimal MSC cell therapeutic product that can be used for bone disorders. There are many bone disorders, most of which cause a great deal of discomfort. Clinically acceptable protocols could be developed in which MSCs are used to aid in bone regeneration providing relief for patients with chronic pain. The aim of this review is to examine the differences between studies conducted in vitro and in vivo with regard to the osteogenic process to better define the gaps in current osteogenic research. By better understanding osteogenic differentiation, we can better define treatment strategies for various bone disorders.

Intra-Arterial Delivery of Mesenchymal Stem Cells for Regenerative Medicine to Treat Peripheral Arterial Disease

Despite therapeutic advances, peripheral arterial disease (PAD) is a rapidly progressing disease, which often Results in critical limb ischemia requiring amputation. Several in vivo studies have shown that perivascular inflammation and intima dysfunction due to PAD might contribute to the development of neointimal hyperplasia. As such, a need exists for new technology to enhance conventional treatments by directly targeting the adventitia. Through the use of porcine models, this study explored intra-arterial delivery of mesenchymal stem cells (MSCs) as a method of targeting and potentially treating arterial walls.

Biomaterials and Adipose-Derived Mesenchymal Stem Cells for Regenerative Medicine: A Systematic Review.

The use of biological templates for the suitable growth of adipose-derived mesenchymal stem cells (AD-MSC) and “neo-tissue” construction has exponentially increased over the last years. The bioengineered scaffolds still have a prominent and biocompatible framework playing a role in tissue regeneration. In order to supply AD-MSCs, biomaterials, as the stem cell niche, are more often supplemented by or stimulate molecular signals that allow differentiation events into several strains, besides their secretion of cytokines and effects of immunomodulation. This systematic review aims to highlight the details of the integration of several types of biomaterials used in association with AD-MSCs, collecting notorious and basic data of in vitro and in vivo assays, taking into account the relevance of the interference of the cell lineage origin and handling cell line protocols for both the replacement and repairing of damaged tissues or organs in clinical application. Our group analyzed the quality and results of the 98 articles selected from PubMed, Scopus and Web of Science. A total of 97% of the articles retrieved demonstrated the potential in clinical applications. The synthetic polymers were the most used biomaterials associated with AD-MSCs and almost half of the selected articles were applied on bone regeneration.

Industry updates from the field of stem cell research and regenerative medicine in June 2021.

The latest developments in the field of stem cell research and regenerative medicine compiled from publicly available information and press releases from nonacademic institutions in June 2021.

Bioprinting of dual ECM scaffolds encapsulating limbal stem/progenitor cells in active and quiescent statuses

Limbal stem cell deficiency and corneal disorders are among the top global threats for human vision. Emerging therapies that integrate stem cell transplantation with engineered hydrogel scaffolds for biological and mechanical support are becoming a rising trend in the field. However, methods for high-throughput fabrication of hydrogel scaffolds, as well as knowledge of the interaction between limbal stem/progenitor cells (LSCs) and the surrounding extracellular matrix (ECM) are still much needed. Here, we employed digital light processing (DLP)-based bioprinting to fabricate hydrogel scaffolds encapsulating primary LSCs and studied the ECM-dependent LSC phenotypes. The DLP-based bioprinting with gelatin methacrylate (GelMA) or hyaluronic acid glycidyl methacrylate (HAGM) generated microscale hydrogel scaffolds that could support the viability of the encapsulated primary rabbit LSCs (rbLSCs) in culture. Immunocytochemistry and transcriptional analysis showed that the encapsulated rbLSCs remained active in GelMA-based scaffolds while exhibited quiescence in the HAGM-based scaffolds. The primary human LSCs encapsulated within bioprinted scaffolds showed consistent ECM-dependent active/quiescent statuses. Based on these results, we have developed a novel bioprinted dual ECM ‘Yin-Yang’ model encapsulating LSCs to support both active and quiescent statues. Our findings provide valuable insights towards stem cell therapies and regenerative medicine for corneal reconstruction.

Long-Term, Noninvasive In Vivo Tracking of Progenitor Cells Using Multimodality Photoacoustic, Optical Coherence Tomography, and Fluorescence Imaging.

Stem cell regenerative medicine therapies have emerged as promising treatments for currently incurable diseases. A remaining challenge for cell therapies is the ability to track the migration and distribution of the transplanted cells in a long-term, noninvasive manner in vivo to assess their efficacy. This study develops a noninvasive, and high spatial resolution photoacoustic microscopy (PAM) and optical coherence tomography (OCT) imaging system for in vivo tracking of subretinally injected progenitor human retinal pigment epithelium cells (ARPE-19) labeled with chainlike gold nanoparticle (CGNP) clusters in RPE damage. CGNP provided significant PAM, OCT, and fluorescence signals to selectively track the migration of ARPE-19 cells in living rabbit eyes for 3 months. PAM and OCT imaging allow accurate anatomical information to determine the exact retinal layer in which the transplanted ARPE-19 cells are located which was confirmed by histology. This presents an efficient and advanced technology to visualize fundamental biological processes of cell therapies in complex in vivo environments in real time.

Cryopreservation of Human Adipose Tissues and Adipose-Derived Stem Cells with DMSO and/or Trehalose: A Systematic Review.

Adipose tissue senescence is implicated as a major player in obesity- and ageing-related disorders. There is a growing body of research studying relevant mechanisms in age-related diseases, as well as the use of adipose-derived stem cells in regenerative medicine. The cell banking of tissue by utilising cryopreservation would allow for much greater flexibility of use. Dimethyl sulfoxide (DMSO) is the most commonly used cryopreservative agent but is toxic to cells. Trehalose is a sugar synthesised by lower organisms to withstand extreme cold and drought that has been trialled as a cryopreservative agent. To examine the efficacy of trehalose in the cryopreservation of human adipose tissue, we conducted a systematic review of studies that used trehalose for the cryopreservation of human adipose tissues and adipose-derived stem cells. Thirteen articles, including fourteen studies, were included in the final review. All seven studies that examined DMSO and trehalose showed that they could be combined effectively to cryopreserve adipocytes. Although studies that compared nonpermeable trehalose with DMSO found trehalose to be inferior, studies that devised methods to deliver nonpermeable trehalose into the cell found it comparable to DMSO. Trehalose is only comparable to DMSO when methods are devised to introduce it into the cell. There is some evidence to support using trehalose instead of using no cryopreservative agent.

Industry updates from the field of stem cell research and regenerative medicine in May 2021.

The latest developments in the field of stem cell research and regenerative medicine compiled from publicly available information and press releases from nonacademic institutions in May 2021.

In vivo CT imaging tracking of stem cells labeled with Au nanoparticles

AbstractStem cell–based therapy offers great promise for a wide range of diseases and injuries that cannot be effectively treated by existing medicine and therapies. However, the translation of stem cell therapy to the clinic is still hampered by the lack of profound understanding about the survival, differentiation, migration, homing, and fate of the transplanted stem cells during the therapy. To address these issues, computed tomography (CT) based on nanomaterials, in particular gold nanoparticles (AuNPs), has been developed for enhanced and long‐term imaging tracking of transplanted stem cells. In this Mini‐Review, we summarize the recent progress in AuNP‐based CT imaging tracking of stem cells, with focuses on new strategies to improve cellular uptake of AuNPs for better CT imaging contrast, and on multimodal imaging tracking of stem cells in vivo. Finally, we discuss the existing challenges and possible future developments of the AuNP‐based CT imaging tracking of stem cells for regenerative medicine and other biomedical applications.

Treatment of idiopathic pulmonary fibrosis with an extracellular vesicle isolate product

Idiopathic Pulmonary Fibrosis (IPF) is associated with serious morbidity and mortality. Airway epithelial cell injury is important in IPF pathogenesis. Injured lung epithelial cells are a source of inflammatory mediators such as TNF-α, IL-1β, GM-CSF, TGFβ, and CXCL-8. Mesenchymal Stem Cells (MSCs) have many anti-inflammatory properties. The clinical efficacy of using mesenchymal stem cells for regenerative medicine is not dependent on the living cells but entirely on their paracrine release of growth factors (GFs) and Extracellular Vesicles (EVs). This a case report of a 74-year-old white male diagnosed with IPF. He had extreme SOB with even small amounts of exertion. CT scanning was consistent with IPF. He was treated with nebulized and IV XoFloTM, a bone marrow derived mesenchymal stem cell extracellular vesicle isolate acellular product. He experienced significant objective improvements with his IPF. His room O2 went from the high 70’s to the high 90’s with improved PFTs.

Adipose Tissue: Understanding the Heterogeneity of Stem Cells for Regenerative Medicine.

Adipose-derived stem cells (ASCs) have been increasingly used as a versatile source of mesenchymal stem cells (MSCs) for diverse clinical investigations. However, their applications often become complicated due to heterogeneity arising from various factors. Cellular heterogeneity can occur due to: (i) nomenclature and criteria for definition; (ii) adipose tissue depots (e.g., subcutaneous fat, visceral fat) from which ASCs are isolated; (iii) donor and inter-subject variation (age, body mass index, gender, and disease state); (iv) species difference; and (v) study design (in vivo versus in vitro) and tools used (e.g., antibody isolation and culture conditions). There are also actual differences in resident cell types that exhibit ASC/MSC characteristics. Multilineage-differentiating stress-enduring (Muse) cells and dedifferentiated fat (DFAT) cells have been reported as an alternative or derivative source of ASCs for application in regenerative medicine. In this review, we discuss these factors that contribute to the heterogeneity of human ASCs in detail, and what should be taken into consideration for overcoming challenges associated with such heterogeneity in the clinical use of ASCs. Attempts to understand, define, and standardize cellular heterogeneity are important in supporting therapeutic strategies and regulatory considerations for the use of ASCs.

Industry updates from the field of stem cell research and regenerative medicine in April 2021.

Latest developments in the field of stem cell research and regenerative medicine compiled from publicly available information and press releases from nonacademic institutions in April 2021.