Fetal Mesenchymal Stromal Cells: an Opportunity for Prenatal Cellular Therapy

Understanding molecular characteristics of extracellular vesicles derived from different types of mesenchymal stem cells for therapeutic translation

Mesenchymal stem cells (MSCs) have been studied for decades as candidates for cellular therapy, and their secretome, including secreted extracellular vesicles (EVs), has been identified to contribute significantly to regenerative and reparative functions. Emerging evidence has suggested that MSC-EVs alone, could be used as therapeutics that emulate the biological function of MSCs. However, just as with MSCs, MSC-EVs have been shown to vary in composition, depending on the tissue source of the MSCs as well as the protocols employed in culturing the MSCs and obtaining the EVs. Therefore, the importance of careful choice of cell sources and culture environments is receiving increasing attention. Many factors contribute to the therapeutic potential of MSC-EVs, including the source tissue, isolation technique, and culturing conditions. This review illustrates the molecular landscape of EVs derived from different types of MSC cells along with culture strategies. A thorough analysis of publicly available omic datasets was performed to advance the precision understanding of MSC-EVs with unique tissue source-dependent molecular characteristics. The tissue-specific protein and miRNA-driven Reactome ontology analysis was used to reveal distinct patterns of top Reactome ontology pathways across adipose, bone marrow, and umbilical MSC-EVs. Moreover, a meta-analysis assisted by an AI technique was used to analyze the published literature, providing insights into the therapeutic translation of MSC-EVs based on their source tissues.

New Perspectives of Therapies in Osteogenesis Imperfecta-A Literature Review

(1) Background: Osteogenesis imperfecta (OI) is a rare skeletal dysplasia characterized as a heterogeneous disorder group with well-defined phenotypic and genetic features that share uncommon bone fragility. The current treatment options, medical and orthopedic, are limited and not efficient enough to improve the low bone density, bone fragility, growth, and mobility of the affected individuals, creating the need for alternative therapeutic agents. (2) Methods: We searched the medical database to find papers regarding treatments for OI other than conventional ones. We included 45 publications. (3) Results: In reviewing the literature, eight new potential therapies for OI were identified, proving promising results in cells and animal models or in human practice, but further research is still needed. Bone marrow transplantation is a promising therapy in mice, adults, and children, decreasing the fracture rate with a beneficial effect on structural bone proprieties. Anti-RANKL antibodies generated controversial results related to the therapy schedule, from no change in the fracture rate to improvement in the bone mineral density resorption markers and bone formation, but with adverse effects related to hypercalcemia. Sclerostin inhibitors in murine models demonstrated an increase in the bone formation rate and trabecular cortical bone mass, and a few human studies showed an increase in biomarkers and BMD and the downregulation of resorption markers. Recombinant human parathormone and TGF-β generated good results in human studies by increasing BMD, depending on the type of OI. Gene therapy, 4-phenylbutiric acid, and inhibition of eIF2α phosphatase enzymes have only been studied in cell cultures and animal models, with promising results. (4) Conclusions: This paper focuses on eight potential therapies for OI, but there is not yet enough data for a new, generally accepted treatment. Most of them showed promising results, but further research is needed, especially in the pediatric field.

Mesenchymal stem cells in the treatment of osteogenesis imperfecta

Osteogenesis imperfecta (OI) is a disease caused by mutations in different genes resulting in mild, severe, or lethal forms. With no cure, researchers have investigated the use of cell therapy to correct the underlying molecular defects of OI. Mesenchymal stem cells (MSCs) are of particular interest because of their differentiation capacity, immunomodulatory effects, and their ability to migrate to sites of damage. MSCs can be isolated from different sources, expanded in culture, and have been shown to be safe in numerous clinical applications. This review summarizes the preclinical and clinical studies of MSCs in the treatment of OI. Altogether, the culmination of these studies show that MSCs from different sources: 1) are safe to use in the clinic, 2) migrate to fracture sites and growth sites in bone, 3) engraft in low levels, 4) improve clinical outcome but have a transient effect, 5) have a therapeutic effect most likely due to paracrine mechanisms, and 6) have a reduced therapeutic potential when isolated from patients with OI.

State of the field: cellular and exosomal therapeutic approaches in vascular regeneration

Pathologies of the vasculature including the microvasculature are often complex in nature, leading to loss of physiological homeostatic regulation of patency and adequate perfusion to match tissue metabolic demands. Microvascular dysfunction is a key underlying element in the majority of pathologies of failing organs and tissues. Contributing pathological factors to this dysfunction include oxidative stress, mitochondrial dysfunction, endoplasmic reticular (ER) stress, endothelial dysfunction, loss of angiogenic potential and vascular density, and greater senescence and apoptosis. In many clinical settings, current pharmacologic strategies use a single or narrow targeted approach to address symptoms of pathology rather than a comprehensive and multifaceted approach to address their root cause. To address this, efforts have been heavily focused on cellular therapies and cell-free therapies (e.g., exosomes) that can tackle the multifaceted etiology of vascular and microvascular dysfunction. In this review, we discuss 1) the state of the field in terms of common therapeutic cell population isolation techniques, their unique characteristics, and their advantages and disadvantages, 2) common molecular mechanisms of cell therapies to restore vascularization and/or vascular function, 3) arguments for and against allogeneic versus autologous applications of cell therapies, 4) emerging strategies to optimize and enhance cell therapies through priming and preconditioning, and, finally, 5) emerging strategies to bolster therapeutic effect. Relevant and recent clinical and animal studies using cellular therapies to restore vascular function or pathologic tissue health by way of improved vascularization are highlighted throughout these sections.

Comparative evaluation of mesenchymal stromal cell growth and osteogenic differentiation on a shape memory polymer scaffold

Trauma-induced, critical-size bone defects pose a clinical challenge to heal. Albeit autografts are the standard-of-care, they are limited by their inability to be shaped to various defect geometries and often incur donor site complications. Herein, the combination of a "self-fitting" shape memory polymer (SMP) scaffold and seeded mesenchymal stromal cells (MSCs) was investigated as an alternative. The porous SMP scaffold, prepared from poly(ε-caprolactone) diacrylate (PCL-DA) and coated with polydopamine, provided conformal shaping and cell adhesion. MSCs from five tissues, amniotic (AMSCs), chorionic tissue (CHSCs), umbilical cord (UCSCs), adipose (ADSCs), and bone marrow (BMSCs) were evaluated for viability, density, and osteogenic differentiation on the SMP scaffold. BMSCs exhibited the fastest increase in cell density by day 3, but after day 10, CHSCs, UCSCs, and ADSCs approached similar cell density. BMSCs also showed the greatest calcification among the cell types, followed closely by ADSCs, CHSCs and AMSCs. Alkaline phosphatase (ALP) activity peaked at day 7 for AMSCs, UCSCs, ADSCs and BMSCs, and at day 14 for CHSCs, which had the greatest overall ALP activity. Of all the cell types, only scaffolds cultured with ADSCs in osteogenic media had increased hardness and local modulus as compared to blank scaffolds after 21 days of cell culture and osteogenic differentiation. Overall, ADSCs performed most favorably on the SMP scaffold. The SMP scaffold was able to support key cellular behaviors of MSCs and could potentially be a viable, regenerative alternative to autograft.

Therapeutic Potential of Human Fetal Mesenchymal Stem Cells in Musculoskeletal Disorders: A Narrative Review

Mesenchymal stem cells (MSCs) have emerged as a promising therapeutic approach for diverse diseases and injuries. The biological and clinical advantages of human fetal MSCs (hfMSCs) have recently been reported. In terms of promising therapeutic approaches for diverse diseases and injuries, hfMSCs have gained prominence as healing tools for clinical therapies. Therefore, this review assesses not the only biological advantages of hfMSCs for healing human diseases and regeneration, but also the research evidence for the engraftment and immunomodulation of hfMSCs based on their sources and biological components. Of particular clinical relevance, the present review also suggests the potential therapeutic feasibilities of hfMSCs for musculoskeletal disorders, including osteoporosis, osteoarthritis, and osteogenesis imperfecta.

OUP accepted manuscript

Fetal growth restriction (FGR) occurs when a fetus is unable to grow normally due to inadequate nutrient and oxygen supply from the placenta. Children born with FGR are at high risk of lifelong adverse neurodevelopmental outcomes, such as cerebral palsy, behavioral issues, and learning and attention difficulties. Unfortunately, there is no treatment to protect the FGR newborn from these adverse neurological outcomes. Chronic inflammation and vascular disruption are prevalent in the brains of FGR neonates and therefore targeted treatments may be key to neuroprotection. Tissue repair and regeneration via stem cell therapies have emerged as a potential clinical intervention for FGR babies at risk for neurological impairment and long-term disability. This review discusses the advancement of research into stem cell therapy for treating neurological diseases and how this may be extended for use in the FGR newborn. Leading preclinical studies using stem cell therapies in FGR animal models will be highlighted and the near-term steps that need to be taken for the development of future clinical trials.

In Utero Fetal Therapy: Stem Cells, Cell Transplantation, Gene Therapy, and CRISPR-Cas9

In utero fetal therapy offers the opportunity to prevent and treat diseases with a cellular or genetic basis. Components of successful fetal treatment include isolation of a replacement cell population, in utero stem cell transplantation, cell engraftment with fetal immune tolerance, and ongoing cell function. Fetal gene therapy with CRISPR-Cas9 represents an exciting potential therapy for genetic diseases not amenable to gene supplementation via adenoviral vector transduction. These fetal therapies have unique ethical and safety considerations. Clinical trials for in utero cell therapy are underway, as additional discoveries in stem cell biology and gene therapy move closer to clinical translation.

Mesenchymal Stem Cell Therapy for Osteogenesis Imperfecta

The aim of this study was to provide a brief overview on the background and rationale on treating fetuses and children suffering from osteogenesis imperfecta (OI) with mesenchymal stem cells (MSCs). MSCs ability to migrate, engraft, and differentiate into bone cells and to act via paracrine effects on the recipient's tissues makes these cells promising candidates as a clinical therapy for OI. Animal work and limited clinical studies in humans support the use of MSC in treating OI. Off-the-shelf MSC have a good safety profile and exhibit multilineage differentiation potential and a low immunogenic profile and thereby may enable this potential therapy to become widely available. MSC transplantation before and after birth to treat OI is an experimental therapy that is currently tested in the international multicentre phase I/II clinical trial BOOSTB4 that aims to assess the safety and efficacy of fetal MSC transplantation for the treatment of severe types of OI.

Living with Osteogenesis Imperfecta: A qualitative study exploring experiences and psychosocial impact from the perspective of patients, parents and professionals

BACKGROUND

Osteogenesis Imperfecta (OI) is a rare genetic condition characterised by increased bone fragility. Recurrent fractures, pain and fatigue have a considerable impact on many aspects of the life of a person affected with OI and their families.

OBJECTIVE

To improve our understanding of the impact of OI on the daily lives of individuals and families and consider how the condition is managed so that support needs can be better addressed.

METHODS

Semi-structured qualitative interviews (n = 56) were conducted with adults affected with OI, with (n = 9) and without children (n = 8), parents of children affected with OI (n = 8), health professionals (n = 29) and patient advocates (n = 2). Interviews were digitally recorded, transcribed verbatim and analysed using thematic analysis.

RESULTS

Three overarching themes are described: OI is not just a physical condition, parenting and family functioning and managing the condition. Fractures, chronic pain and tiredness impact on daily life and emotional well-being. For parents with OI, pain, tiredness and mobility issues can limit interactions and activities with their children. Specialist paediatric health services for OI were highly valued. The need for more emotional support and improved coordination of adult health services was highlighted.

CONCLUSIONS

Our findings allow a better understanding of the day-to-day experiences of individuals and families affected with OI. Supporting emotional well-being needs greater attention from policy makers and researchers. Improvements to the coordination of health services for adults with OI are needed and an in-depth exploration of young people's support needs is warranted with research focused on support through the teenage years.

Mesenchymal stromal cells in hematopoietic cell transplantation

Mesenchymal stromal cells (MSCs) are widely recognized to possess potent immunomodulatory activity, as well as to stimulate repair and regeneration of diseased or damaged tissue. These fundamental properties suggest important applications in hematopoietic cell transplantation. Although the mechanisms of therapeutic activity in vivo are yet to be fully elucidated, MSCs seem to suppress lymphocytes by paracrine mechanisms, including secreted mediators and metabolic modulators. Most recently, host macrophage engulfment of apoptotic MSCs has emerged as an important contributor to the immune suppressive microenvironment. Although bone marrow-derived MSCs are the most commonly studied, the tissue source of MSCs may be a critical determinant of immunomodulatory function. The key application of MSC therapy in hematopoietic cell transplantation is to prevent or treat graft-versus-host disease (GVHD). The pathogenesis of GVHD reveals multiple potential targets. Moreover, the recently proposed concept of tissue tolerance suggests a new possible mechanism of MSC therapy for GVHD. Beyond GVHD, MSCs may facilitate hematopoietic stem cell engraftment, which could gain greater importance with increasing use of haploidentical transplantation. Despite many challenges and much doubt, commercial MSC products for pediatric steroid-refractory GVHD have been licensed in Japan, conditionally licensed in Canada and New Zealand, and have been recommended for approval by an FDA Advisory Committee in the United States. Here, we review key historical data in the context of the most salient recent findings to present the current state of MSCs as adjunct cell therapy in hematopoietic cell transplantation.

Current Overview of Osteogenesis Imperfecta

Osteogenesis imperfecta (OI), or brittle bone disease, is a heterogeneous disorder characterised by bone fragility, multiple fractures, bone deformity, and short stature. OI is a heterogeneous disorder primarily caused by mutations in the genes involved in the production of type 1 collagen. Severe OI is perinatally lethal, while mild OI can sometimes not be recognised until adulthood. Severe or lethal OI can usually be diagnosed using antenatal ultrasound and confirmed by various imaging modalities and genetic testing. The combination of imaging parameters obtained by ultrasound, computed tomography (CT), and magnetic resource imaging (MRI) can not only detect OI accurately but also predict lethality before birth. Moreover, genetic testing, either noninvasive or invasive, can further confirm the diagnosis prenatally. Early and precise diagnoses provide parents with more time to decide on reproductive options. The currently available postnatal treatments for OI are not curative, and individuals with severe OI suffer multiple fractures and bone deformities throughout their lives. In utero mesenchymal stem cell transplantation has been drawing attention as a promising therapy for severe OI, and a clinical trial to assess the safety and efficacy of cell therapy is currently ongoing. In the future, early diagnosis followed by in utero stem cell transplantation should be adopted as a new therapeutic option for severe OI.

Ethical and Regulatory Considerations of Placental Therapeutics

PURPOSE

Placental therapeutics aim to treat placental disease; however, ethical and regulatory issues should be considered if the drug also potentially affects the fetus. Drugs that might transfer or edit genes carry a specific challenge because currently fetal gene editing and fetal gene therapy are considered unethical.

METHODS

This article reviews the literature on ethical and regulatory considerations for placental therapeutics.

FINDINGS

Proposals for maternal gene therapy, directed to the maternal side of the placenta, have been discussed with patients and stakeholders. No absolute ethical, legal, or regulatory barriers to this potential treatment were identified. Patients who have experienced placental disease, such as fetal growth restriction, are interested in these therapies; some would participate in first-in-human trials. Such trials need careful regulatory considerations, such as the steps required to indicate tolerability and efficacy in preclinical models and the optimal animals for reproductive toxicology studies. Ex vivo dual human placenta perfusion experiments and villous explant in vitro studies allow drugs to be tested in normal and diseased human placenta, providing short-term tolerability and toxicologic assessment. Testing drugs in nonhuman primates is an option but carries ethical and feasibility considerations. Selection of inclusion and exclusion criteria for clinical trial participants is important to ensure that the most suitable patients are exposed to a first-in-human drug. These patients will almost certainly be pregnant women with a high risk of perinatal loss and/or perinatal and maternal morbidity. Criteria should identify sufficient numbers of patients to make a trial feasible as well as a phenotype that will respond to the mechanism of action. How to dose escalate and to capture information on adverse events are also key to optimal clinical trial design.

IMPLICATIONS

Developing placental therapeutics requires input from scientists, practitioners, and regulators and close liaison with patients to ensure that new drugs are tested as carefully as possible.

Key Metabolic Pathways in MSC-Mediated Immunomodulation: Implications for the Prophylaxis and Treatment of Graft Versus Host Disease

Mesenchymal stromal cells (MSCs) are spindle-shaped, plastic-adherent cells in vitro with potent immunosuppressive activity both in vitro and in vivo. MSCs have been employed as a cellular immunotherapy in diverse preclinical models and clinical trials, but most commonly as agents for the prophylaxis or therapy of graft versus host disease after hematopoietic cell transplantation. In addition to the oft studied secreted cytokines, several metabolic pathways intrinsic to MSCs, notably indoleamine 2,3-dioxygenase, prostaglandin E2, hypoxia-inducible factor 1 α, heme oxygenase-1, as well as energy-generating metabolism, have been shown to play roles in the immunomodulatory activity of MSCs. In this review, we discuss these key metabolic pathways in MSCs which have been reported to contribute to MSC therapeutic effects in the setting of hematopoietic cell transplantation and graft versus host disease. Understanding the contribution of MSC metabolism to immunomodulatory activity may substantially inform the development of future clinical applications of MSCs.

Influence of culture media on the derivation and phenotype of fetal-derived placental mesenchymal stem/stromal cells across gestation

INTRODUCTION

Derivation of pure fetal placental mesenchymal stem/stromal cells (pMSCs) is key to understand their role in placental development. However, isolated pMSCs are often contaminated by maternal-derived decidual MSCs (dMSCs). EGM-2 medium promotes the derivation of term fetal pMSCs, but the extent of first-trimester maternal pMSC contamination remains unclear. Culture media can also affect MSC phenotype. Here, we examined the effects of culture media on maternal pMSC contamination and fetal pMSC phenotype across gestation.

METHODS

pMSCs were derived from first-trimester or term placentae in advanced-DMEM/F12 medium or EGM-2 medium. Proportions of maternal (XX) and fetal (XY) cells in male pMSC cultures were determined by fluorescence in-situ hybridization. pMSC phenotype was analysed by flow cytometry, immunohistochemistry and Alamar blue proliferation assays.

RESULTS

When derived in advanced-DMEM/F12, all first trimester pMSC isolates exhibited maternal contamination (>72% XX cells, n = 5), whilst 7/9 term pMSC isolates were >98% fetal. When derived in EGM-2, all first trimester (n = 4) and term (n = 9) pMSC isolates contained 95-100% fetal cells. Fetal pMSCs in EGM-2 proliferated 2-fold (first-trimester) or 4-fold (term) faster than those in advanced-DMEM/F12 (p < 0.05, n = 3). Fetal pMSCs in both media expressed the generic MSC marker profile (CD90⁺, CD105+, CD73⁺, CD31-, CD34-, CD144-). However, pMSCs transferred from EGM-2 to advanced-DMEM/F12 increased expression of smooth muscle cell markers calponin and α-smooth muscle actin, and decreased expression of the vascular cell marker VEGFR2 (n = 3).

CONCLUSIONS

Deriving first-trimester pMSC in EGM-2 dramatically reduces maternal dMSC contamination. Media affects fetal pMSC phenotype, and careful consideration should be given to application specific culture conditions.

Stem Cell Therapy as a Treatment for Osteogenesis Imperfecta

PURPOSE OF REVIEW

Osteogenesis imperfecta (OI) is a chronic disease with few treatment options available. The purpose of this review is to provide an overview on treating OI with mesenchymal stem cells (MSC).

RECENT FINDINGS

Off-the-shelf MSC have a good safety profile and exhibit multilineage differentiation potential and a low immunogenic profile and are easy to manufacture. Their ability to migrate, engraft, and differentiate into bone cells, and also to act via paracrine effects on the recipient's tissues, makes MSC candidates as a clinical therapy for OI. Due to their high osteogenic potency, fetal MSC offer an even higher therapeutic potential in OI compared with MSC derived from adult sources. Preclinical and initial clinical data support the use of MSC in treating OI. The characteristics of MSC make them of great interest in treating OI. MSC may be safely transplanted via intravenous administration and show potential positive clinical effects.

Reproductive options for families at risk of Osteogenesis Imperfecta: a review

Background

Osteogenesis Imperfecta (OI) is a rare genetic disorder involving bone fragility. OI patients typically suffer from numerous fractures, skeletal deformities, shortness of stature and hearing loss. The disorder is characterised by genetic and clinical heterogeneity. Pathogenic variants in more than 20 different genes can lead to OI, and phenotypes can range from mild to lethal forms. As a genetic disorder which undoubtedly affects quality of life, OI significantly alters the reproductive confidence of families at risk. The current review describes a selection of the latest reproductive approaches which may be suitable for prospective parents faced with a risk of OI. The aim of the review is to alleviate suffering in relation to family planning around OI, by enabling prospective parents to make informed and independent decisions.

Main body

The current review provides a comprehensive overview of possible reproductive options for people with OI and for unaffected carriers of OI pathogenic genetic variants. The review considers reproductive options across all phases of family planning, including pre-pregnancy, fertilisation, pregnancy, and post-pregnancy. Special attention is given to the more modern techniques of assisted reproduction, such as preconception carrier screening, preimplantation genetic testing for monogenic diseases and non-invasive prenatal testing. The review outlines the methodologies of the different reproductive approaches available to OI families and highlights their advantages and disadvantages. These are presented as a decision tree, which takes into account the autosomal dominant and autosomal recessive nature of the OI variants, and the OI-related risks of people without OI.

The complex process of decision-making around OI reproductive options is also discussed from an ethical perspective.

Conclusion

The rapid development of molecular techniques has led to the availability of a wide variety of reproductive options for prospective parents faced with a risk of OI. However, such options may raise ethical concerns in terms of methodologies, choice management and good clinical practice in reproductive care, which are yet to be fully addressed.

In utero Exposure to Maternal Chronic Inflammation Transfers a Pro-Inflammatory Profile to Generation F2 via Sex-Specific Mechanisms

Generational transfer of maladaptations in offspring have been reported to persist for multiple generations in conditions of chronic inflammation, metabolic and psychological stress. Thus, the current study aimed to expand our understanding of the nature, potential sex specificity, and transgenerational plasticity of inflammatory maladaptations resulting from maternal chronic inflammation. Briefly, F1 and F2 generations of offspring from C57/BL/6 dams exposed to a modified maternal periconception systemic inflammation (MSPI) protocol were profiled in terms of leukocyte and splenocyte counts and cytokine responses, as well as glucocorticoid sensitivity. Overall, F1 male and female LPS groups presented with glucocorticoid hypersensitivity (with elevated corticosterone and increased leukocyte glucocorticoid receptor levels) along with a pro-inflammatory phenotype, which carried over to the F2 generation. The transfer of inflammatory and glucocorticoid responsiveness from F1 to F2 is evident, with heritability of this phenotype in F2. The findings suggest that maternal (F0) perinatal chronic inflammation resulted in glucocorticoid dysregulation and a resultant pro-inflammatory phenotype, which is transferred in the maternal lineage but seems to affect male offspring to a greater extent. Of further interest, upregulation of IL-1β cytokine responses is reported in female offspring only. The cumulative maladaptation reported in F2 offspring when both F1 parents were affected by maternal LPS exposure is suggestive of immune senescence. Given the potential impact of current results and the lack of sex-specific investigations, more research in this context is urgently required.

Current status in therapeutic interventions of neonatal bone mineral metabolic disorders

Neonatal care has significantly improved in the past decade with improved survival of preterm and sick neonates. Similarly, the field of bone and mineral disorders is continuing to accelerate with better understanding of pathophysiology and genetic basis of diseases, as well as availability of newer diagnostic and therapeutic modalities. In this extensive and rapidly expanding field, metabolic bone disease specialists are frequently called upon to translate progress into better care for neonates with bone and mineral disorders. Accordingly, this chapter provides a review of clinical manifestations and evidence-based investigation and management (where available) of common, rare and ultra-rare disorders of bone and mineral metabolism manifesting in the neonatal period. Besides medical treatment we emphasise the crucial role of the multidisciplinary team, which include physical therapists, occupational therapists and dieticians, in the care of neonates with bone disorders such as osteogenesis imperfecta and achondroplasia.

GMP-Compliant Production of Human Placenta-Derived Mesenchymal Stem Cells

Mesenchymal stem cells are one of the most attractive sources for stem cell research and therapy. Their safety and efficacy have been demonstrated in many clinical trials. Because of their low immunogenicity and immunomodulatory properties, allogenic MSCs have been transplanted in different clinical studies. MSCs could be in different adult- and fetal-derived tissues including pregnancy products. Placenta-derived mesenchymal stem cells (PLMSCs) that can be harvested without using any invasive procedures from a discarding tissue are one of the important types of mesenchymal stem cells for therapeutic applications. Stem cell manufacturing for therapeutic applications should be in compliance with the basic principles of good manufacturing practice (GMP). Herein, the current chapter is to describe GMP-compliant production of human PLMSCs, which are suitable for clinical applications.

The current and future impact of genome-wide sequencing on fetal precision medicine

Next-generation sequencing and other genomic technologies are transforming prenatal and reproductive screening and testing for fetal genetic disorders at an unprecedented pace. Original approaches of screening and testing for fetal genetic and genomic disorders were focused on a few more prevalent conditions that were easily diagnosable with pre-genomic era diagnostic tools. First, chromosomal microarray analysis and then next-generation sequencing brought technology capable of more detailed genomic evaluation to prenatal genetic screening and diagnosis. This has facilitated parallel introduction of a variety of new tests on maternal blood samples, including expanded carrier screening and cell-free DNA-based non-invasive screening for fetal aneuploidy, selected copy number variants, and single-gene disorders. Genomic tests on fetal DNA samples, obtained primarily through amniocentesis or chorionic villus sampling, include chromosomal microarray analysis and gene panel and exome sequencing. All these form the diagnostic pillar of the emerging field of fetal precision medicine, but their implementation is associated with ethical, counseling and healthcare resource utilization challenges. We discuss where in the reproductive and prenatal care continuum these exciting new technologies are integrated, along with associated challenges. We propose areas of priority for research to gain the data in support of their responsible implementation into clinical reproductive and prenatal care.

Prenatal stem cell therapy for inherited diseases: Past, present, and future treatment strategies

Imagine the profits in quality of life that can be made by treating inherited diseases early in life, maybe even before birth! Immense cost savings can also be made by treating diseases promptly. Hence, prenatal stem cell therapy holds great promise for developing new and early‐stage treatment strategies for several diseases. Successful prenatal stem cell therapy would represent a major step forward in the management of patients with hematological, metabolic, or immunological disorders. However, treatment before birth has several limitations, including ethical issues. In this review, we summarize the past, the present, and the future of prenatal stem cell therapy, which includes an overview of different stem cell types, preclinical studies, and clinical attempts treating various diseases. We also discuss the current challenges and future strategies for prenatal stem cell therapy and also new approaches, which may lead to advancement in the management of patients with severe incurable diseases.

Stakeholder views and attitudes towards prenatal and postnatal transplantation of fetal mesenchymal stem cells to treat Osteogenesis Imperfecta

The Boost Brittle Bones Before Birth (BOOSTB4) clinical trial is investigating the safety and efficacy of transplanting fetal derived mesenchymal stromal cells (MSCs) prenatally and/or in early postnatal life to treat severe Osteogenesis Imperfecta (OI). This study aimed to explore stakeholder views to understand perceived benefits or concerns, identify ethical issues and establish protocols for support and counselling. Semi-structured qualitative interviews were conducted with three groups; 1. Adults affected with OI, with and without children, and parents of children affected with OI; 2. Health professionals who work with patients with OI; 3. Patient advocates from relevant patient support groups. Interviews were digitally recorded, transcribed verbatim and analysed using thematic analysis. Interviews with 56 participants revealed generally positive views towards using fetal MSC transplantation to treat OI. Early treatment was considered advantageous for preventing fractures and reducing severity and could bring psychological benefits for parents. Common concerns were procedure safety, short/long-term side effects and whether transplantation would be effective. Difficulties inherent in decision-making were frequently discussed, as treatment efficacy is unknown and, by necessity, parents will make decisions at a time when they are vulnerable. Support needs may differ where there is a family history of OI compared to an unexpected diagnosis of OI. Explaining fetal MSC transplantation in a way that all parents can understand, clear expectation setting, psychological support and time for reflection during the decision-making process will be crucial to allow parents to make informed decisions about participation in the BOOSTB4 clinical trial.

Effects of physiological aging factor on bone tissue engineering repair based on fetal BMSCs

Background

At present, many laboratories and hospitals all over the world are attempting and exploring the clinical transformation of this tissue engineered bone graft (TEBG) strategy. Many successful cases of bone tissue engineering (BTE) repair were based on young individuals. But there are little studies about the effectiveness of TEBG strategy in physiological aged individuals.

Methods

In this research, we studied whether aging factor has influence on the skull repair effect of Fetal-TEBG, at the level of the large animal models. We used the fetal bone marrow stromal cells (Fetal-BMSCs) as the seed cells, combining the decalcified bone matrix (DBM) scaffolds, to repair the skull defects of the aged goats and the young goats. The repair effects on both aged goat and young goat were compared by Micro-CT and histology examination.

Results

The skull defects of the young goats could be repaired better than that of the aged goats after 6 months by Fetal-TEBG; In the aged goats, although not completely repaired, the defects repaired by Fetal-TEBG was better than that repaired by the Control DBM scaffold.

Conclusions

Aging factor has impact on the bone repair effect of Fetal-TEBG; and the BTE strategy is still efficacious even in the aged individuals. The improvement of the aged state may promote the repair effect of the BTE in the aged individuals.

65 YEARS OF THE DOUBLE HELIX: The advancements of gene editing and potential application to hereditary cancer

Hereditary cancer predisposition syndromes are associated with germline mutations that lead to increased vulnerability for an individual to develop cancers. Such germline mutations in tumour suppressor genes, oncogenes and genes encoding for proteins essential in DNA repair pathways and cell cycle control can cause overall chromosomal instability in the genome and increase risk in developing cancers. Gene correction of these germline mutations to restore normal protein functions is anticipated as a new therapeutic option. This can be achieved through disruption of gain-of-function pathogenic mutation, restoration of loss-of-function mutation, addition of a transgene essential for cell function and single nucleotide changes. Genome editing tools are applicable to precise gene correction. Development of genome editing tools comes in two waves. The first wave focuses on improving targeting specificity and editing efficiency of nucleases, and the second wave of gene editing draws on innovative engineering of fusion proteins combining deactivated nucleases and other enzymes that are able to create limitless functional molecular tools. This gene editing advancement is going to impact medicine, particularly in hereditary cancers. In this review, we discuss the application of gene editing as an early intervention and possible treatment for hereditary cancers, by highlighting a selection of highly penetrant cancer syndromes as examples of how this may be achieved in clinical practice.