CRISPR-Cas9: a promising tool for gene editing on induced pluripotent stem cells

CRISPR Gene Therapy: A Promising One-Time Therapeutic Approach for Transfusion-Dependent β-Thalassemia—CRISPR-Cas9 Gene Editing for β-Thalassemia

β-Thalassemia is an inherited hematological disorder that results from genetic changes in the β-globin gene, leading to the reduced or absent synthesis of β-globin. For several decades, the only curative treatment option for β-thalassemia has been allogeneic hematopoietic cell transplantation (allo-HCT). Nonetheless, rapid progress in genome modification technologies holds great potential for treating this disease and will soon change the current standard of care for β-thalassemia. For instance, the emergence of the CRISPR/Cas9 genome editing platform has opened the door for precision gene editing and can serve as an effective molecular treatment for a multitude of genetic diseases. Investigational studies were carried out to treat β-thalassemia patients utilizing CRISPR-based CTX001 therapy targeting the fetal hemoglobin silencer BCL11A to restore γ-globin expression in place of deficient β-globin. The results of recently carried out clinical trials provide hope of CTX001 being a promising one-time therapeutic option to treat β-hemoglobinopathies. This review provides an insight into the key scientific steps that led to the development and application of novel CRISPR/Cas9–based gene therapies as a promising therapeutic platform for transfusion-dependent β-thalassemia (TDT). Despite the resulting ethical, moral, and social challenges, CRISPR provides an excellent treatment option against hemoglobin-associated genetic diseases.

CRISPR Manipulations in Stem Cell Lines

Insights into genome engineering in cells have allowed researchers to cultivate and modify cells as organoids that display structural and phenotypic features of human diseases or normal health status. The generation of targeted mutants is a crucial step toward studying the biomedical effect of genes of interest. Modified organoids derived from patients' tissue cells are used as models to study diseases and test novel drugs. CRISPR-Cas9 technology has contributed to an explosion of advances that have the ability to edit genomes for the study of monogenic diseases and cancers. The generation of such mutants in human induced pluripotent stem cells (iPSCs) is of utmost importance as these cells carry the potential to be differentiated into any cell lineage. We describe recent developments that are broadening our understanding and extend DNA specificity, product selectivity, and fundamental capabilities. Furthermore, fundamental capabilities and remarkable advancements in basic research, biotechnology, and therapeutics development in cell engineering are detailed within this chapter. Using the CRISPR/Cas9 nuclease system for induction of targeted double-strand breaks, gene editing of target loci in iPSCs can be achieved with high efficiency. This chapter includes detailed protocols for the preparation of reagents to target loci of interest and transfection to genotype single cell-derived iPSC clones. Furthermore, we provide a protocol for the convenient generation of ribonucleoprotein (RNP) delivered directly to cells.

Towards an artificial human lung: modelling organ-like complexity to aid mechanistic understanding

Respiratory diseases account for over 5 million deaths yearly and are a huge burden to healthcare systems worldwide. Murine models have been of paramount importance to decode human lung biology in vivo, but their genetic, anatomical, physiological and immunological differences with humans significantly hamper successful translation of research into clinical practice. Thus, to clearly understand human lung physiology, development, homeostasis and mechanistic dysregulation that may lead to disease, it is essential to develop models that accurately recreate the extraordinary complexity of the human pulmonary architecture and biology. Recent advances in micro-engineering technology and tissue engineering have allowed the development of more sophisticated models intending to bridge the gap between the native lung and its replicates in vitro Alongside advanced culture techniques, remarkable technological growth in downstream analyses has significantly increased the predictive power of human biology-based in vitro models by allowing capture and quantification of complex signals. Refined integrated multi-omics readouts could lead to an acceleration of the translational pipeline from in vitro experimental settings to drug development and clinical testing in the future. This review highlights the range and complexity of state-of-the-art lung models for different areas of the respiratory system, from nasal to large airways, small airways and alveoli, with consideration of various aspects of disease states and their potential applications, including pre-clinical drug testing. We explore how development of optimised physiologically relevant in vitro human lung models could accelerate the identification of novel therapeutics with increased potential to translate successfully from the bench to the patient's bedside.

Description of CRISPR-Cas9 development and its prospects in human papillomavirus-driven cancer treatment

Human papillomaviruses (HPVs) have been recognized as the etiologic agents of various cancers and are called HPV-driven cancers. Concerning HPV-mediated carcinogenic action, gene therapy can cure cancer at the molecular level by means of the correction of specific genes or sites. CRISPR-Cas9, as a novel genetic editing technique, can correct errors in the genome and change the gene expression and function in cells efficiently, quickly, and with relative ease. Herein, we overviewed studies of CRISPR-mediated gene remedies for HPV-driven cancers and summarized the potential applications of CRISPR-Cas9 in gene therapy for cancer.

Ten decadal advances in fungal biology leading towards human well-being

Fungi are an understudied resource possessing huge potential for developing products that can greatly improve human well-being. In the current paper, we highlight some important discoveries and developments in applied mycology and interdisciplinary Life Science research. These examples concern recently introduced drugs for the treatment of infections and neurological diseases; application of -OMICS techniques and genetic tools in medical mycology and the regulation of mycotoxin production; as well as some highlights of mushroom cultivaton in Asia. Examples for new diagnostic tools in medical mycology and the exploitation of new candidates for therapeutic drugs, are also given. In addition, two entries illustrating the latest developments in the use of fungi for biodegradation and fungal biomaterial production are provided. Some other areas where there have been and/or will be significant developments are also included. It is our hope that this paper will help realise the importance of fungi as a potential industrial resource and see the next two decades bring forward many new fungal and fungus-derived products.

In vitro models for head and neck cancer: Current status and future perspective

The 5-year overall survival rate remains approximately 50% for head and neck (H&N) cancer patients, even though new cancer drugs have been approved for clinical use since 2016. Cancer drug studies are now moving toward the use of three-dimensional culture models for better emulating the unique tumor microenvironment (TME) and better predicting in vivo response to cancer treatments. Distinctive TME features, such as tumor geometry, heterogenous cellularity, and hypoxic cues, notably affect tissue aggressiveness and drug resistance. However, these features have not been fully incorporated into in vitro H&N cancer models. This review paper aims to provide a scholarly assessment of the designs, contributions, and limitations of in vitro models in H&N cancer drug research. We first review the TME features of H&N cancer that are most relevant to in vitro drug evaluation. We then evaluate a selection of advanced culture models, namely, spheroids, organotypic models, and microfluidic chips, in their applications for H&N cancer drug research. Lastly, we propose future opportunities of in vitro H&N cancer research in the prospects of high-throughput drug screening and patient-specific drug evaluation.

Poliovirus non-permissive CD155 knockout cells derived from RD cell line for handling poliovirus potentially infectious materials in virology laboratories

STATEMENTS OF THE PROBLEM

Destruction of all poliovirus containing materials, safe and secure handling of retained polioviruses for vaccine production and research will be obligatory to eliminate facility-associated risks. Polioviruses and poliovirus potentially infectious materials (PIM) include fecal or respiratory samples requiring containment have been defined in WHO-GAPIII documents. Non-polio laboratories culturing viruses from PIM are most affected as cell cultures of human and monkey origin are also poliovirus permissive.

METHOD OF STUDY

CRISPR gene-editing technology was used to knockout the poliovirus receptor (PVR/CD155) gene in RD cell line. PVR knockout RD cell susceptibility was tested using known non-polio enterovirus types. A selected clone (RD-SJ40) was field evaluated for virus isolation from 626 stool samples of AFP cases.

RESULTS

Poliovirus non-permissive cells derived from RD cell line did not show CD155-specific cell-surface immunofluorescence. CD155 gene sequencing confirmed nucleotide base pair deletions within exon2 and exon3. The CD155 knockout RD-SJ40 cells did not support the growth of poliovirus from positive stool samples. All NPEV types were isolated in RD and RD-SJ40 cells.

CONCLUSION

CRISPR correctly edited CD155 gene of RD cells to render them poliovirus non-permissive while susceptibility to NPEV remained unchanged. RD-SJ40 cells are safe for NPEV isolation from poliovirus PIM without derogating GAPIII containment requirements. This article is protected by copyright. All rights reserved.

Extracellular vesicles: Emerging tools as therapeutic agent carriers

Extracellular vesicles (EVs) are secreted by both eukaryotes and prokaryotes, and are present in all biological fluids of vertebrates, where they transfer DNA, RNA, proteins, lipids, and metabolites from donor to recipient cells in cell-to-cell communication. Some EV components can also indicate the type and biological status of their parent cells and serve as diagnostic targets for liquid biopsy. EVs can also natively carry or be modified to contain therapeutic agents (e.g., nucleic acids, proteins, polysaccharides, and small molecules) by physical, chemical, or bioengineering strategies. Due to their excellent biocompatibility and stability, EVs are ideal nanocarriers for bioactive ingredients to induce signal transduction, immunoregulation, or other therapeutic effects, which can be targeted to specific cell types. Herein, we review EV classification, intercellular communication, isolation, and characterization strategies as they apply to EV therapeutics. This review focuses on recent advances in EV applications as therapeutic carriers from in vitro research towards in vivo animal models and early clinical applications, using representative examples in the fields of cancer chemotherapeutic drug, cancer vaccine, infectious disease vaccines, regenerative medicine and gene therapy. Finally, we discuss current challenges for EV therapeutics and their future development.

An episomal DNA vector platform for the persistent genetic modification of pluripotent stem cells and their differentiated progeny

The genetic modification of stem cells (SCs) is typically achieved using integrating vectors, whose potential integrative genotoxicity and propensity for epigenetic silencing during differentiation limit their application. The genetic modification of cells should provide sustainable levels of transgene expression, without compromising the viability of a cell or its progeny. We developed nonviral, nonintegrating, and autonomously replicating minimally sized DNA nanovectors to persistently genetically modify SCs and their differentiated progeny without causing any molecular or genetic damage. These DNA vectors are capable of efficiently modifying murine and human pluripotent SCs with minimal impact and without differentiation-mediated transgene silencing or vector loss. We demonstrate that these vectors remain episomal and provide robust and sustained transgene expression during self-renewal and targeted differentiation of SCs both in vitro and in vivo through embryogenesis and differentiation into adult tissues, without damaging their phenotypic characteristics.

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Nanovectors are used to engineer SCs efficiently, safely, and persistently

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Isogenic SC lines retain their capacity for self-renewal and pluripotency

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Nanovectors survive reprogramming and differentiation without loss or silencing

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Nanovectors are a universal genetic tool for the modification of any cell

Identification of Novel Insulin Resistance Related ceRNA Network in T2DM and Its Potential Editing by CRISPR/Cas9

Background: Type 2 diabetes mellitus is one of the leading causes of morbidity and mortality worldwide and is derived from an accumulation of genetic and epigenetic changes. In this study, we aimed to construct Insilco, a competing endogenous RNA (ceRNA) network linked to the pathogenesis of insulin resistance followed by its experimental validation in patients’, matched control and cell line samples, as well as to evaluate the efficacy of CRISPR/Cas9 as a potential therapeutic strategy to modulate the expression of this deregulated network. By applying bioinformatics tools through a two-step process, we identified and verified a ceRNA network panel of mRNAs, miRNAs and lncRNA related to insulin resistance, Then validated the expression in clinical samples (123 patients and 106 controls) and some of matched cell line samples using real time PCR. Next, two guide RNAs were designed to target the sequence flanking LncRNA/miRNAs interaction by CRISPER/Cas9 in cell culture. Gene editing tool efficacy was assessed by measuring the network downstream proteins GLUT4 and mTOR via immunofluorescence. Results: LncRNA-RP11-773H22.4, together with RET, IGF1R and mTOR mRNAs, showed significant upregulation in T2DM compared with matched controls, while miRNA (i.e., miR-3163 and miR-1) and mRNA (i.e., GLUT4 and AKT2) expression displayed marked downregulation in diabetic samples. CRISPR/Cas9 successfully knocked out LncRNA-RP11-773H22.4, as evidenced by the reversal of the gene expression of the identified network at RNA and protein levels to the normal expression pattern after gene editing. Conclusions: The present study provides the significance of this ceRNA based network and its related target genes panel both in the pathogenesis of insulin resistance and as a therapeutic target for gene editing in T2DM.

Current Applications and Future Perspectives of CRISPR-Cas9 for the Treatment of Lung Cancer

Clustered Regularly Interspaced Short Palindromic Repeats and CRISPR-associated proteins are referred to as CRISPR-Cas9. Bacteria and archaea have an adaptive (acquired) immune system. As a result, developing the best single regulated RNA and Cas9 endonuclease proteins and implementing the method in clinical practice would aid in the treatment of diseases of various origins, including lung cancers. This seminar aims to provide an overview of CRISPR-Cas9 technology, as well as current and potential applications and perspectives for the method, as well as its mechanism of action in lung cancer therapy. This technology can be used to treat lung cancer in two different ways. The first approach involves creating single directed RNA and Cas9 proteins and then distributing them to cancer cells using suitable methods. Single directed RNA looks directly at the lung's mutated epidermal growth factor receptor and makes a complementary match, which is then cleaved with Cas9 protein, slowing cancer progression. The second method is to manipulate the expression of ligand-receptors on immune lymphocytic cells. For example, if the CRISPR-Cas9 system disables the expression of cancer receptors on lymphocytes, it decreases the contact between the tumor cell and its ligand-receptor, thus slowing cancer progression.

Basic and Preclinical Research for Personalized Medicine

Basic and preclinical research founded the progress of personalized medicine by providing a prodigious amount of integrated profiling data and by enabling the development of biomedical applications to be implemented in patient-centered care and cures. If the rapid development of genomics research boosted the birth of personalized medicine, further development in omics technologies has more recently improved our understanding of the functional genome and its relevance in profiling patients’ phenotypes and disorders. Concurrently, the rapid biotechnological advancement in diverse research areas enabled uncovering disease mechanisms and prompted the design of innovative biological treatments tailored to individual patient genotypes and phenotypes. Research in stem cells enabled clarifying their role in tissue degeneration and disease pathogenesis while providing novel tools toward the development of personalized regenerative medicine strategies. Meanwhile, the evolving field of integrated omics technologies ensured translating structural genomics information into actionable knowledge to trace detailed patients’ molecular signatures. Finally, neuroscience research provided invaluable models to identify preclinical stages of brain diseases. This review aims at discussing relevant milestones in the scientific progress of basic and preclinical research areas that have considerably contributed to the personalized medicine revolution by bridging the bench-to-bed gap, focusing on stem cells, omics technologies, and neuroscience fields as paradigms.

CRISPR-mediated gene modification of hematopoietic stem cells with beta-thalassemia IVS-1-110 mutation

Background

β-Thalassemias represent a group of genetic disorders caused by human hemoglobin beta (HBB) gene mutations. The radical curative approach is to correct the mutations causing the disease. CRISPR-CAS9 is a novel gene-editing technology that can be used auspiciously for the treatment of these disorders. The study aimed to investigate the utility of CRISPR-CAS9 for gene modification of hematopoietic stem cells in β-thalassemia with IVS-1-110 mutation.

Methods and results

We successfully isolated CD34⁺ cells from peripheral blood of β-thalassemia patients with IVS-1-110 mutation. The cells were transfected with Cas9 endonuclease together with guide RNA to create double-strand breaks and knock out the mutation. The mutation-corrected CD34⁺ cells were subjected to erythroid differentiation by culturing in complete media containing erythropoietin.

Conclusion

CRISPR/Cas-9 is an effective tool for gene therapy that will broaden the spectrum of therapy and potentially improve the outcomes of β-thalassemia.

Novel genetic therapeutic approaches for modulating the severity of β-thalassemia (Review)

Thalassemia is a genetic haematological disorder that arises due to defects in the α and β-globin genes. Worldwide, 0.3-0.4 million children are born with haemoglobinopathies per year. Thalassemic patients, as well as their families, face various serious clinical, socio-economic, and psychosocial challenges throughout their life. Different therapies are available in clinical practice to minimize the suffering of thalassemic patients to some extent and potentially cure the disease. Predominantly, patients undergo transfusion therapy to maintain their haemoglobin levels. Due to multiple transfusions, the iron levels in their bodies are elevated. Iron overload results in damage to body organs, resulting in heart failure, liver function failure or endocrine failure, all of which are commonly observed. Certain drugs have been developed to enhance the expression of the γ-gene, which ultimately results in augmentation of fetal haemoglobin (HbF) levels and total haemoglobin levels in the body. However, its effectiveness is dependent on the genetic makeup of the individual patient. At present, allogeneic haematopoietic Stem Cell Transplantation (HSCT) is the only practically available option with a high curative rate. However, the outcome of HSCT is strongly influenced by factors such as age at transplantation, irregular iron chelation history before transplantation, histocompatibility, and source of stem cells. Gene therapy using the lentiglobin vector is the most recent method for cure without any mortality, graft rejection and clonal dominance issues. However, delayed platelet engraftment is being reported in some patients. Genome editing is a novel approach which may be used to treat patients with thalassemia; it makes use of targeted nucleases to correct the mutations in specific DNA sequences and modify the sequence to the normal wild-type sequence. To edit the genome at the required sites, CRISPR/Cas9 is an efficient and accurate tool that is used in various genetic engineering programs. Genome editing mediated by CRISPR/Cas9 has the ability to restore the normal β-globin function with minimal side effects. Using CRISPR/Cas9, expression of BCL11A can be downregulated along with increased production of HbF. However, these genome editing tools are still under in-vitro trials. CRISPR/Cas9 has can be used for precise transcriptional regulation, genome modification and epigenetic editing. Additional research is required in this regard, as CRISPR/Cas9 may potentially exhibit off-target activity and there are legal and ethical considerations regarding its use.

Application of CRISPR/Cas9 to human-induced pluripotent stem cells: from gene editing to drug discovery

Human-induced pluripotent stem cells (hiPSCs) and CRISPR/Cas9 gene editing system represent two instruments of basic and translational research, which both allow to acquire deep insight about the molecular bases of many diseases but also to develop pharmacological research.This review is focused to draw up the latest technique of gene editing applied on hiPSCs, exploiting some of the genetic manipulation directed to the discovery of innovative therapeutic strategies. There are many expediencies provided by the use of hiPSCs, which can represent a disease model clinically relevant and predictive, with a great potential if associated to CRISPR/Cas9 technology, a gene editing tool powered by ease and precision never seen before.Here, we describe the possible applications of CRISPR/Cas9 to hiPSCs: from drug development to drug screening and from gene therapy to the induction of the immunological response to specific virus infection, such as HIV and SARS-Cov-2.

La edición del ADN

Dentro del mundo de las ciencias biológicas la terapia génica ha sido un tema llamativo desde su aparición. El desarrollo de nuevas tecnologías y avances en el campo de la bioingeniería como las nucleasas de dedos de zinc (ZFN), las nucleasas tipo activadores de transcripción (TALEN) y las repeticiones palindrómicas cortas agrupadas y regularmente interespaciadas (CRISPR/Cas9), abrieron las puertas a un sinnúmero de posibilidades en biología, entre ellas, la edición del genoma. Esta última consiste en la modificación directa del genoma a través de la introducción o escisión de secuencias nucleotídicas dentro de la hebra de ADN. Hoy en día su aplicación es extensa, desde el campo de la agroindustria y el control de plagas hasta el ámbito clínico con la “corrección” de enfermedades mendelianas, modulación de receptores inmunológicos en enfermedades infecciosas, modificaciones genéticas en líneas germinales, entre muchos otros empleos. Sin embargo, desde su descubrimiento en 1987, el sistema CRISPR/Cas9 no ha estado exento de polémica en aspectos bioéticos, la adquisición de su patente e, incluso, en cuanto a su eficacia. A pesar de las dificultades e incertidumbre que han surgido, el futuro del sistema es prometedor dada su sencillez y versatilidad de uso.

CRISPR/Cas9-based targeted genome editing for correction of recessive dystrophic epidermolysis bullosa using iPS cells

Recessive dystrophic epidermolysis bullosa (RDEB) is a severe inherited skin disorder caused by mutations in the COL7A1 gene encoding type VII collagen (C7). The spectrum of severity depends on the type of mutation in the COL7A1 gene. C7 is the major constituent of anchoring fibrils (AFs) at the basement membrane zone (BMZ). Patients with RDEB lack functional C7 and have severely impaired dermal-epidermal stability, resulting in extensive blistering and open wounds on the skin that greatly affect the patient's quality of life. There are currently no therapies approved for the treatment of RDEB. Here, we demonstrated the correction of mutations in exon 19 (c.2470insG) and exon 32 (c.3948insT) in the COL7A1 gene through homology-directed repair (HDR). We used the clustered regulatory interspaced short palindromic repeats (CRISPR) Cas9-gRNAs system to modify induced pluripotent stem cells (iPSCs) derived from patients with RDEB in both the heterozygous and homozygous states. Three-dimensional human skin equivalents (HSEs) were generated from gene-corrected iPSCs, differentiated into keratinocytes (KCs) and fibroblasts (FBs), and grafted onto immunodeficient mice, which showed normal expression of C7 at the BMZ as well as restored AFs 2 mo postgrafting. Safety assessment for potential off-target Cas9 cleavage activity did not reveal any unintended nuclease activity. Our findings represent a crucial advance for clinical applications of innovative autologous stem cell-based therapies for RDEB.

Applications of RNA interference in the treatment of arthritis

RNA interference (RNAi) is a cellular mechanism for post-transcriptional gene regulation mediated by small interfering RNA (siRNA) and microRNA. siRNA-based therapy holds significant promise for the treatment of a wide-range of arthritic diseases. siRNA selectively suppresses the expression of a gene product and can thus achieve the specificity that is lacking in small molecule inhibitors. The potential use of siRNA-based therapy in arthritis, however, has not progressed to clinical trials despite ample evidence for efficacy in preclinical studies. One of the main challenges to clinical translation is the lack of a suitable delivery vehicle to efficiently and safely access diverse pathologies. Moreover, the ideal targets in treatment of arthritides remain elusive given the complexity and heterogeneity of these disease pathogeneses. Herein, we review recent preclinical studies that use RNAi-based drug delivery systems to mitigate inflammation in models of rheumatoid arthritis and osteoarthritis. We discuss a self-assembling peptide-based nanostructure that demonstrates the potential of overcoming many of the critical barriers preventing the translation of this technology to the clinic.

Aging: A cell source limiting factor in tissue engineering

Tissue engineering has yet to reach its ideal goal, i.e. creating profitable off-the-shelf tissues and organs, designing scaffolds and three-dimensional tissue architectures that can maintain the blood supply, proper biomaterial selection, and identifying the most efficient cell source for use in cell therapy and tissue engineering. These are still the major challenges in this field. Regarding the identification of the most appropriate cell source, aging as a factor that affects both somatic and stem cells and limits their function and applications is a preventable and, at least to some extents, a reversible phenomenon. Here, we reviewed different stem cell types, namely embryonic stem cells, adult stem cells, induced pluripotent stem cells, and genetically modified stem cells, as well as their sources, i.e. autologous, allogeneic, and xenogeneic sources. Afterward, we approached aging by discussing the functional decline of aged stem cells and different intrinsic and extrinsic factors that are involved in stem cell aging including replicative senescence and Hayflick limit, autophagy, epigenetic changes, miRNAs, mTOR and AMPK pathways, and the role of mitochondria in stem cell senescence. Finally, various interventions for rejuvenation and geroprotection of stem cells are discussed. These interventions can be applied in cell therapy and tissue engineering methods to conquer aging as a limiting factor, both in original cell source and in the in vitro proliferated cells.

CRISPR-Cas9 mediated CD133 knockout inhibits colon cancer invasion through reduced epithelial-mesenchymal transition

We previously reported that CD133, as a putative cancer stem cell marker, plays an important role in cell proliferation and invasion in colon cancer. To understand the role of CD133 expression in colon cancer, we evaluated the inhibitory effect of CD133 in colon cancer cells. In this study, we generated CD133^knockout colon cancer cells (LoVo) using the CRISPR-Cas9 gene editing system. CD133⁺ colon cancer cells (LoVo) were infected with the lentiviral vector carrying CD133 gRNA and purified cell by culturing single cell colonies. CD133^knockout cells was validated by western blot and flow cytometry analysis. In functional study, we observed a significant reduction in cell proliferation and colony formation in CRISPR-Cas9 mediated CD133 ^knockout cells in compare with control (P < 0.001). We also found the anticancer effect of stattic was dependent on CD133 expression in colon cancer cells. Although CD133^knockout cells could not completely block the tumorigenic property, they showed remarkable inhibitory effects on the ability of cell migration and invasion (P < 0.001). In addition, we examined the epithelial mesenchymal transition (EMT)-related protein expression by western blot. The result clearly showed a loss of vimentin expression in CD133^knockout cells. Therefore, CRISPR-Cas9 mediated CD133^knockout can be an effective treatment modality for CD133⁺ colon cancer through reducing the characteristics of cancer stem cells.

Enabling Hamster Embryo Culture System: Development of Preimplantation Embryos

Development of preimplantation embryos, from fertilization to hatched-blastocyst stage, has been a challenging task, regardless of the mammalian species being studied. While the mouse model has been versatile for studying in vitro development of early embryos, other rodent species are important to gain insights into comparative early embryogenesis. The golden hamster (Mesocricetus auratus) offers unique advantages to study cellular and molecular regulation of gamete maturation, fertilization and preimplantation development, including the phenomenon of blastocyst hatching. Achieving in vitro fertilization and first cleavage division is relatively easy; however, subsequent development past the two-/four-cell stage had been difficult in hamsters. Pioneering research, carried out over three decades has markedly enabled successful in vitro development of one-cell embryos to blastocysts. This article provides a comprehensive perspective (historical and current) on the embryo culture systems and details an optimized culture protocols to achieve normal and viable development of preimplantation embryos in the golden hamster.

CRISPR-Cas9 targeting of MMP13 in human chondrocytes leads to significantly reduced levels of the metalloproteinase and enhanced type II collagen accumulation

OBJECTIVE

To investigate the efficacy of CRISPR-Cas9 mediated editing in human chondrocytes, and to develop a genome editing approach relevant to cell-based repair.

METHODS

Transfection of human articular chondrocytes (both healthy and osteoarthritic) with ribonucleoprotein complexes (RNP) containing Cas9 and a crisprRNA targeting exon2 of MMP13 was performed to assess editing efficiency and effects on MMP13 protein levels and enzymatic activity. Using spheroid cultures, protein levels of a major target of MMP13, type II collagen, were assessed by western blot and immunofluorescence.

RESULTS

With an editing efficiency of 63-74%, secreted MMP13 protein levels and activity were significantly reduced (percentage decrease 34.14% without and 67.97% with IL-1β based on median values of MMP13 enzymatic activity, N = 7) comparing non-edited with edited cell populations using an exon-targeting gRNA resulting in premature stop codons through non-homologous end joining (NHEJ). Accumulation of cartilage matrix protein type II collagen was enhanced in edited cells in spheroid culture, compared to non-edited controls.

CONCLUSION

CRISPR-Cas9 mediated genome editing can be used to efficiently and reproducibly establish populations of human chondrocytes with stably reduced expression of key genes of interest without the need for clonal selection. Such an editing approach has the potential to greatly enhance current cell-based therapies for cartilage repair.

Generation of Human Stem Cell-Derived Pancreatic Organoids (POs) for Regenerative Medicine

Insulin-dependent diabetes mellitus or type 1 diabetes mellitus (T1DM) is an auto-immune condition characterized by the loss of pancreatic β-cells. The curative approach for highly selected patients is the pancreas or the pancreatic islet transplantation. Nevertheless, these options are limited by a growing shortage of donor organs and by the requirement of immunosuppression.Xenotransplantation of porcine islets has been extensively investigated. Nevertheless, the strong xenoimmunity and the risk of transmission of porcine endogenous retroviruses, have limited their application in clinic. Generation of β-like cells from stem cells is one of the most promising strategies in regenerative medicine. Embryonic, and more recently, adult stem cells are currently the most promising cell sources exploited to generate functional β-cells in vitro. A number of studies demonstrated that stem cells could generate functional pancreatic organoids (POs), able to restore normoglycemia when implanted in different preclinical diabetic models. Nevertheless, a gradual loss of function and cell dead are commonly detected when POs are transplanted in immunocompetent animals. So far, the main issue to be solved is the post-transplanted islet loss, due to the host immune attack. To avoid this hurdle, nanotechnology has provided a number of polymers currently under investigation for islet micro and macro-encapsulation. These new approaches, besides conferring PO immune protection, are able to supply oxygen and nutrients and to preserve PO morphology and long-term viability.Herein, we summarize the current knowledge on bioengineered POs and the stem cell differentiation platforms. We also discuss the in vitro strategies used to generate functional POs, and the protocols currently used to confer immune-protection against the host immune attack (micro- and macro-encapsulation). In addition, the most relevant ongoing clinical trials, and the most relevant hurdles met to move towards clinical application are revised.

Efficient Gene Editing of Human Induced Pluripotent Stem Cells Using CRISPR/Cas9

The generation of targeted mutants is a crucial step toward studying the biomedical effect of genes of interest. The generation of such mutants in human induced pluripotent stem cells (iPSCs) is of an utmost importance as these cells carry the potential to be differentiated into any cell lineage. Using the CRISPR/Cas9 nuclease system for induction of targeted double-strand breaks, gene editing of target loci in iPSCs can be achieved with high efficiency. This chapter covers protocols for the preparation of reagents to target loci of interest, the transfection, and for the genotyping of single cell-derived iPSC clones. Furthermore, we provide a protocol for the convenient generation of plasmids enabling multiplex gene targeting.

Retinitis pigmentosa: recent advances and future directions in diagnosis and management

PURPOSE OF REVIEW

Retinitis pigmentosa is a group of genetically diverse inherited blinding disorders for which there are no treatments. Owing to recent advances in imaging technology, DNA sequencing, gene therapy, and stem cell biology, clinical trials have multiplied and the landscape is rapidly changing. This review provides a relevant and timely update of current trends and future directions for the diagnosis and management of this disease.

RECENT FINDINGS

This review will highlight the use of retinal imaging to measure progression of disease, next-generation sequencing for genetic diagnosis, the use of electronic retinal implants as well as noninvasive digital low-vision aids, and the current state of preclinical and clinical research with gene therapy and cell-based therapies.

SUMMARY

Retinitis pigmentosa has historically been an untreatable condition. Recent advances have allowed for limited improvement in visual outcomes for select patients. Retinal degenerative disease is on the cutting edge of regenerative medicine. Gene therapy and stem cell therapeutic strategies are currently under investigation and are expected to radically impact management of inherited retinal disease in the coming years. VIDEO ABSTRACT: http://links.lww.com/MOP/A33.

CRISPR/Cas9-mediated genome editing in human stem cell-derived cardiomyocytes: Applications for cardiovascular disease modelling and cardiotoxicity screening

Cardiovascular diseases (CVDs) are leading causes of death worldwide, and drug-induced cardiotoxicity is among the most common cause of drug withdrawal from the market. Improved models of cardiac tissue are needed to study the mechanisms of CVDs and drug-induced cardiotoxicity. Human pluripotent stem cell-derived cardiomyocytes (hPSC-CM) have provided a major advance to our ability to study these conditions. Combined with efficient genome editing technologies, such as CRISPR/Cas9, we now have the ability to study with greater resolution the genetic causes and underlying mechanisms of inherited and drug-induced cardiotoxicity, and to investigate new treatments. Here, we review recent advances in the use of hPSC-CMs and CRISPR/Cas9-mediated genome editing to study cardiotoxicity and model CVD.

CRISPR therapeutic tools for complex genetic disorders and cancer (Review)

One of the fundamental discoveries in the field of biology is the ability to modulate the genome and to monitor the functional outputs derived from genomic alterations. In order to unravel new therapeutic options, scientists had initially focused on inducing genetic alterations in primary cells, in established cancer cell lines and mouse models using either RNA interference or cDNA overexpression or various programmable nucleases [zinc finger nucleases (ZNF), transcription activator-like effector nucleases (TALEN)]. Even though a huge volume of data was produced, its use was neither cheap nor accurate. Therefore, the clustered regularly interspaced short palindromic repeats (CRISPR) system was evidenced to be the next step in genome engineering tools. CRISPR-associated protein 9 (Cas9)-mediated genetic perturbation is simple, precise and highly efficient, empowering researchers to apply this method to immortalized cancerous cell lines, primary cells derived from mouse and human origins, xenografts, induced pluripotent stem cells, organoid cultures, as well as the generation of genetically engineered animal models. In this review, we assess the development of the CRISPR system and its therapeutic applications to a wide range of complex diseases (particularly distinct tumors), aiming at personalized therapy. Special emphasis is given to organoids and CRISPR screens in the design of innovative therapeutic approaches. Overall, the CRISPR system is regarded as an eminent genome engineering tool in therapeutics. We envision a new era in cancer biology during which the CRISPR-based genome engineering toolbox will serve as the fundamental conduit between the bench and the bedside; nonetheless, certain obstacles need to be addressed, such as the eradication of side-effects, maximization of efficiency, the assurance of delivery and the elimination of immunogenicity.

Induced pluripotent stem cell models of lysosomal storage disorders

Induced pluripotent stem cells (iPSCs) have provided new opportunities to explore the cell biology and pathophysiology of human diseases, and the lysosomal storage disorder research community has been quick to adopt this technology. Patient-derived iPSC models have been generated for a number of lysosomal storage disorders, including Gaucher disease, Pompe disease, Fabry disease, metachromatic leukodystrophy, the neuronal ceroid lipofuscinoses, Niemann-Pick types A and C1, and several of the mucopolysaccharidoses. Here, we review the strategies employed for reprogramming and differentiation, as well as insights into disease etiology gleaned from the currently available models. Examples are provided to illustrate how iPSC-derived models can be employed to develop new therapeutic strategies for these disorders. We also discuss how models of these rare diseases could contribute to an enhanced understanding of more common neurodegenerative disorders such as Parkinson’s disease, and discuss key challenges and opportunities in this area of research.

Summary: This Review discusses how induced pluripotent stem cells (iPSCs) provide new opportunities to explore the biology and pathophysiology of lysosomal storage diseases, and how iPSCs have illuminated the role of lysosomes in more common disorders.

Disease Modeling Using 3D Organoids Derived from Human Induced Pluripotent Stem Cells

The rising interest in human induced pluripotent stem cell (hiPSC)-derived organoid culture has stemmed from the manipulation of various combinations of directed multi-lineage differentiation and morphogenetic processes that mimic organogenesis. Organoids are three-dimensional (3D) structures that are comprised of multiple cell types, self-organized to recapitulate embryonic and tissue development in vitro. This model has been shown to be superior to conventional two-dimensional (2D) cell culture methods in mirroring functionality, architecture, and geometric features of tissues seen in vivo. This review serves to highlight recent advances in the 3D organoid technology for use in modeling complex hereditary diseases, cancer, host–microbe interactions, and possible use in translational and personalized medicine where organoid cultures were used to uncover diagnostic biomarkers for early disease detection via high throughput pharmaceutical screening. In addition, this review also aims to discuss the advantages and shortcomings of utilizing organoids in disease modeling. In summary, studying human diseases using hiPSC-derived organoids may better illustrate the processes involved due to similarities in the architecture and microenvironment present in an organoid, which also allows drug responses to be properly recapitulated in vitro.

Genome-editing applications of CRISPR-Cas9 to promote in vitro studies of Alzheimer's disease

Genetic variations play an important role in the clinical presentation and progression of Alzheimer’s disease (AD), especially early-onset Alzheimer’s disease. Hundreds of mutations have been reported with the majority resulting from alterations in β-amyloid precursor protein (APP), presenilin 1 (PSEN1), or presenilin 2 (PSEN2) genes. The roles of these mutations in the pathogenesis of AD have been classically confirmed or refuted through functional studies, where the mutations are cloned, inserted into cell lines, and monitored for changes in various properties including cell survival, amyloid production, or Aβ42/40 ratio. However, these verification studies tend to be expensive, time consuming, and inconsistent. Recently, the clustered regularly interspaced short palindromic repeats-CRISPR-associated protein 9 (CRISPR–Cas9) system was developed, which improves sequence-specific gene editing in cell lines, organs, and animals. CRISPR–Cas9 is a promising tool for the generation of models of human genetic diseases and could facilitate the establishment of new animal AD models and the observation of dynamic bioprocesses in AD. Here, we recapitulated the history of CRISPR technology, recent progress, and, especially, its potential applications in AD-related genetic, animal modeling, and functional studies.

Different Chondrogenic Potential among Human Induced Pluripotent Stem Cells from Diverse Origin Primary Cells

Scientists have tried to reprogram various origins of primary cells into human induced pluripotent stem cells (hiPSCs). Every somatic cell can theoretically become a hiPSC and give rise to targeted cells of the human body. However, there have been debates on the controversy about the differentiation propensity according to the origin of primary cells. We reprogrammed hiPSCs from four different types of primary cells such as dermal fibroblasts (DF, n = 3), peripheral blood mononuclear cells (PBMC, n = 3), cord blood mononuclear cells (CBMC, n = 3), and osteoarthritis fibroblast-like synoviocytes (OAFLS, n = 3). Established hiPSCs were differentiated into chondrogenic pellets. All told, cartilage-specific markers tended to express more by the order of CBMC > DF > PBMC > FLS. Origin of primary cells may influence the reprogramming and differentiation thereafter. In the context of chondrogenic propensity, CBMC-derived hiPSCs can be a fairly good candidate cell source for cartilage regeneration. The differentiation of hiPSCs into chondrocytes may help develop “cartilage in a dish” in the future. Also, the ideal cell source of hiPSC for chondrogenesis may contribute to future application as well.

Risk associated with off-target plant genome editing and methods for its limitation

Assessment for potential adverse effects of plant genome editing logically focuses on the specific characteristics of the derived phenotype and its release environment. Genome-edited crops, depending on the editing objective, can be classified as either indistinguishable from crops developed through conventional plant breeding or as crops which are transgenic. Therefore, existing regulatory regimes and risk assessment procedures accommodate genome-edited crops. The ability for regulators and the public to accept a product focus in the evaluation of genome-edited crops will depend on research which clarifies the precision of the genome-editing process and evaluates unanticipated off-target edits from the process. Interpretation of genome-wide effects of genome editing should adhere to existing frameworks for comparative risk assessment where the nature and degree of effects are considered relative to a baseline of genome-wide mutations as found in crop varieties developed through conventional breeding methods. Research addressing current uncertainties regarding unintended changes from plant genome editing, and adopting procedures that clearly avoid the potential for gene drive initiation, will help to clarify anticipated public and regulatory questions regarding risk of crops derived through genome editing.

Cancer-derived exosomes as a delivery platform of CRISPR/Cas9 confer cancer cell tropism-dependent targeting

An intracellular delivery system for CRISPR/Cas9 is crucial for its application as a therapeutic genome editing technology in a broad range of diseases. Current vehicles carrying CRISPR/Cas9 limit in vivo delivery because of low tolerance and immunogenicity; thus, the in vivo delivery of genome editing remains challenging. Here, we report that cancer-derived exosomes function as natural carriers that can efficiently deliver CRISPR/Cas9 plasmids to cancer. Compared to epithelial cell-derived exosomes, cancer-derived exosomes provide potential vehicles for effective in vivo delivery via selective accumulation in ovarian cancer tumors of SKOV3 xenograft mice, most likely because of their cell tropism. CRISPR/Cas9-loaded exosomes can suppress expression of poly (ADP-ribose) polymerase-1 (PARP-1), resulting in the induction of apoptosis in ovarian cancer. Furthermore, the inhibition of PARP-1 by CRISPR/Cas9-mediated genome editing enhances the chemosensitivity to cisplatin, showing synergistic cytotoxicity. Based on these results, tumor-derived exosomes may be very promising for cancer therapeutics in the future.

Stem cell transplantation for Huntington's diseases

Therapeutic approaches based on stem cells have received considerable attention as potential treatments for Huntington's disease (HD), which is a fatal, inherited neurodegenerative disorder, caused by progressive loss of GABAergic medium spiny neurons (MSNs) in the striatum of the forebrain. Transplantation of stem cells or their derivatives in animal models of HD, efficiently improved functions by replacing the damaged or lost neurons. In particular, neural stem cells (NSCs) for HD treatments have been developed from various sources, such as the brain itself, the pluripotent stem cells (PSCs), and the somatic cells of the HD patients. However, the brain-derived NSCs are difficult to obtain, and the PSCs have to be differentiated into a population of the desired neuronal cells that may cause a risk of tumor formation after transplantation. In contrast, induced NSCs, derived from somatic cells as a new stem cell source for transplantation, are less likely to form tumors. Given that the stem cell transplantation strategy for treatment of HD, as a genetic disease, is to replace the dysfunctional or lost neurons, the correction of mutant genes containing the expanded CAG repeats is essential. In this review, we will describe the methods for obtaining the optimal NSCs for transplantation-based HD treatment and the differentiation conditions for the functional GABAergic MSNs as therapeutic cells. Also, we will discuss the valuable gene correction of the disease stem cells by the CRISPR/Cas9 system for HD treatment.