Search Results (90)

The morphogenesis of the primordial gut relies on signaling pathways such as Wnt, FGF, Notch, Hedgehog, and Hippo. Reciprocal crosstalk between the endoderm and mesoderm is integrated into the signaling pathways, resulting in craniocaudal patterning. These pathways are also involved in adult intestinal homeostasis including cell proliferation and specification of cell fate. Perturbations in this process can cause growth disturbances manifesting as adenomas, serrated lesions, and cancer. Significant differences have been observed between right and left colon cancers in the hindgut, and between the jejunoileum, appendix, and right colon in the midgut. The question is to what extent the embryology of the mid- and hindgut contributes to differences in the underlying tumor biology. This review examines the precursor lesions and consensus molecular subtypes (CMS) of colorectal cancer (CRC) to highlight the significance of embryology and tumor microenvironment (TME) in CRC. The three main precursor lesions, i.e., adenomas, serrated lesions, and inflammatory bowel disease-associated dysplasia, are linked to the CMS classification, which is based on transcriptomic profiling and clinical features. Both embryologic and micro-environmental underpinnings of the mid- and hindgut contribute to the differences in the tumors arising from them, and they may do so by recapitulating embryonic signaling cascades. This manifests in the range of CRC CMS and histologic cancer subtypes and in tumors that show multidirectional differentiation, the so-called stem cell carcinomas. Emerging evidence shows the limitations of CMS particularly in patients on systemic therapy who develop drug resistance. The focus is thus transitioning from CMS to specific components of the TME. Full article

Regenerative medicine is the branch of medicine that aims to repair and regenerate damaged tissues and presents promising avenues for addressing a wide range of currently incurable diseases. Regenerative medicine is based on the use of cell therapy with stem cells that can differentiate into differentiated cells of specific tissues. There are various types of stem cells, which are different in potential and derivation. The aim of this review is to summarize the types of stem cells most studied and recently discovered, from adult stem cells to innovative induced pluripotent stem cells (iPSCs), for regenerative medicine purposes. The stem cells involved in the identification of new regenerative therapeutic approaches are analyzed here through a classification based on the tissues’ embryonic derivation: stem cells from ectodermal derivation tissues, stem cells from mesodermal derivation tissues, stem cells from endodermal derivation tissues, and iPSCs. Full article

Species have different strategies for implantation and placentation. Much can be learned about general molecular and cellular biology through the examination and comparison of these differences. To varying degrees, implantation in all species includes alterations in epithelial polarity, the transformation of the endometrial stroma, the differentiation of the trophoblast, cell-to-cell and tissue-to-tissue signaling through hormones, cytokines, and extracellular vesicles, and the alteration of the maternal immune system. This review focuses on implantation in pigs, sheep, and cows. These species share with mice/rats and humans/primates the key events of early embryonic development, pregnancy recognition, and the establishment of functional placentation. However, there are differences between the pregnancies of livestock and other species that make livestock unique biomedical models for the study of pregnancy and cell biology in general. Pig, sheep, and cow conceptuses (embryo/fetus and associated placental membranes) elongate prior to implantation, displaying central implantation, extended periods of conceptus attachment to the uterus, and epitheliochorial (pigs) and synepitheliochorial (sheep and cows) placentation. This review will discuss what is understood about how the trophoblast and extraembryonic endoderm of pig, sheep, and cow conceptuses elongate, and how a major goal of current in vitro models is to achieve conceptus elongation. It will then examine the adhesion cascade for conceptus implantation that initiates early placental development in pigs, sheep, and cows. Finally, it will conclude with a brief overview of early placental development in pigs, sheep, and cows, with a listing of some important “omics” studies that have been published. Full article

Background: The bone morphogenetic protein (BMP) signaling pathway is essential for lung development. BMP4, a key regulator, binds to type I (BMPR1) and type II (BMPR2) receptors to initiate downstream signaling. While the inactivation of Bmpr1a and Bmpr1b leads to tracheoesophageal fistulae, the role of BMPR2 mutations in lung epithelial development remains unclear. Methods: We generated induced pluripotent stem cells (iPSCs) from a patient carrying a BMPR2 mutation (c.631C>T), and gene-corrected isogenic controls were created using CRISPR/Cas9. These iPSCs were differentiated into lung progenitor cells and subsequently cultured to generate alveolar and airway organoids. The differentiation efficiency and epithelial lineage specification were assessed using immunofluorescence, flow cytometry, and qRT-PCR. Results: BMPR2-mutant iPSCs showed no impairment in forming a definitive or anterior foregut endoderm. However, a significant reduction in lung progenitor cell differentiation was observed. Further, while alveolar epithelial differentiation remained largely unaffected, airway organoids derived from BMPR2-mutant cells exhibited impaired goblet and ciliated cell development, with an increase in basal and club cell markers, indicating skewing toward undifferentiated airway cell populations. Conclusions: BMPR2 dysfunction selectively impairs late-stage lung progenitor specification and disrupts airway epithelial maturation, providing new insights into the developmental impacts of BMPR2 mutations. Full article

Definitive endoderm (DE) differentiation leads to the development of the major internal organs including the liver, intestines, pancreas, gall bladder, prostate, bladder, thyroid, and lungs. The two primary methods utilized for in vitro differentiation of induced pluripotent stem cells (iPSCs) into DE cells are the growth factor (GF) and the small molecule (SM) approaches. The GSK-3 inhibitor (CHIR99021) is a key factor for the SM approach. Activin A and Wnt3a are utilized in the GF approach. In this study, both the GF and SM protocols were compared to each other. The results show that both the GF and SM protocol produce DE with a similar morphological phenotype, gene and protein expression, and a similar level of homogeneity and functionality. However, on both the gene expression and proteomic level, there is a divergence between the two protocols during hepatic specification. Proteomic analysis shows that hepatoblasts from the GF protocol have significantly differentially expressed proteins (DEPs) involved in liver metabolic pathways compared to the SM protocol. Well-validated DE differentiation protocols are needed to fully unlock the clinical potential of iPSCs. In the first step of generating DE-derived tissue, either protocol can be utilized. However, for hepatic specification, the GF protocol is more effective. Full article

Human induced pluripotent stem cells (hiPSCs) hold great potential for regenerative medicine. However, optimizing their differentiation into specific lineages within three-dimensional (3D) scaffold-based culture systems that mimic in vivo environments remains challenging. This study examined the trilineage differentiation of hiPSCs under various 3D conditions using synthetic peptide hydrogel matrices with and without embryoid body (EB) medium induction. hiPSC 3D colonies (spheroids), naturally formed from single cells or small clusters in 3D culture, were used for differentiation into the three germ lineages. Differentiated spheroids exhibited distinct morphological characteristics and significantly increased expression of key lineage-specific markers—FOXA2 (endoderm), Brachyury (mesoderm), and PAX6 (ectoderm)—compared to undifferentiated controls. Marker expression varied depending on the 3D culture conditions. Differentiation efficiency improved significantly, increasing from 16% to 71% for endoderm, 61% to 80% for mesoderm, and 35% to 48% for ectoderm, by selecting the appropriate 3D matrix and applying EB induction. Comprehensive data analysis from RT-qPCR, immunocytochemistry staining, and flow cytometry confirmed that the Synthegel Spheroid (SGS) is a viable 3D matrix for evaluating all three germ lineages using a commercial trilineage differentiation kit. While EB induction is essential for endodermal differentiation, it is not required for mesodermal and ectodermal lineages. These findings are valuable not only for screening initial differentiation potential at the lineage level but also for optimizing 3D differentiation protocols for deriving somatic cells from hiPSCs. Full article

The piggyBac+TET-on transposon induction system has a high efficiency in integrating exogenous genes in multiple cell types, can precisely integrate to reduce genomic damage, has a flexible gene expression regulation, and a strong genetic stability. When used in conjunction with somatic cell nuclear transfer experiments, it can precisely and effectively reveal the intrinsic mechanisms of early biological development. This study successfully reprogrammed black-boned sheep fibroblasts (SFs) into induced pluripotent stem cells (iPSCs) using the piggyBac+TET-on transposon system and investigated their impact on early embryonic development. Seven exogenous reprogramming factors (bovine OCT4, SOX2, KLF4, cMyc, porcine NANOG, Lin-28, and SV40 Large T) were delivered into SFs, successfully inducing iPSCs. A growth performance analysis revealed that iPSC clones exhibited a raised or flat morphology with clear edges, positive alkaline phosphatase staining, and normal karyotypes. The transcriptome analysis indicated a significant enrichment of iPSCs in oxidative phosphorylation and cell proliferation pathways, with an up-regulated expression of the ATP5B, SDHB, Bcl-2, CDK1, and Cyclin D1 genes and a down-regulated expression of BAX (p < 0.05). Somatic cell nuclear transfer experiments demonstrated that the cleavage rate (85% ± 2.12) and blastocyst rate (52% ± 2.11) of the iPSCs were significantly higher than those of the SFs (p < 0.05). The detection of trilineage marker genes confirmed that the expression levels of endoderm (DCN, NANOS3, FOXA2, FOXD3, SOX17), mesoderm (KDR, CD34, NFH), and ectoderm (NEUROD) markers in iPSCs were significantly higher than in SFs (p < 0.01). The findings demonstrate that black-boned sheep iPSCs possess pluripotency and the potential to differentiate into all three germ layers, revealing the mechanisms by which reprogrammed iPSCs influence early embryonic development and providing a critical foundation for research on sheep pluripotent stem cells. Full article

The human genome sequencing revealed a vast complexity of transcripts, with over 80% of the genome being transcribed into non-coding RNAs. In particular, long non-coding RNAs (lncRNAs) have emerged as critical regulators of various cellular processes, including embryonic development and stem cell differentiation. Despite extensive efforts to identify and characterize lncRNAs, defining their mechanisms of action in state-specific cellular contexts remains a significant challenge. Only recently has the involvement of lncRNAs in human endoderm differentiation of pluripotent stem cells begun to be addressed, creating an opportunity to explore the mechanisms by which lncRNAs exert their functions in germ layer formation, lineage specification, and commitment. This review summarizes current findings on the roles of lncRNAs in endoderm differentiation, highlighting the functional mechanisms and regulatory aspects underlying their involvement in cell fate decisions leading to endoderm development. The key lncRNAs implicated in endoderm differentiation are discussed, along with their interaction with transcription factors and RNA-binding proteins and modulation of signaling pathways essential for endoderm development. Gaining insight into the regulatory roles of lncRNAs in endoderm differentiation enhances the understanding of developmental biology and provides a foundation for discovering novel lncRNAs involved in cell fate determination. Full article

Talpid3 is a basal body protein required for the formation of primary cilia, an organelle involved in signal transduction. Here, we asked if Talpid3 has a role in the regulation of differentiation and/or self-renewal of ES cells and whether cells lacking cilia due to a deletion in Talpid3 can be reprogrammed to induced pluripotent stem (iPS) cells. We show that mouse embryonic limb fibroblasts which lack primary cilia with a targeted deletion in the Talpid3 (Ta3) gene can be efficiently reprogrammed to iPS cells. Furthermore, vector-free Ta3^−/− iPS cells retain ES cell features and are able to self-renew. However, both Ta3^−/− iPS and ES cells are unable to form visceral endoderm and differentiate poorly into neurons. The observed defects are not a consequence of reprogramming since Ta3^−/− ES cells also exhibit this phenotype. Thus, Talpid3 and primary cilia are required for some differentiation events but appear to be dispensable for stem cell self-renewal and reprogramming. Full article

Induced pluripotent stem cells (iPSCs) can be generated from various adult cells, genetically modified and differentiated into diverse cell populations. Type I interferons (IFN-Is) have multiple immunotherapeutic applications; however, their systemic administration can lead to severe adverse outcomes. One way of overcoming the limitation is to introduce cells able to enter the site of pathology and to produce IFN-Is locally. As a first step towards the generation of such cells, here, we aimed to generate human iPSCs overexpressing interferon-beta (IFNB, IFNB-iPSCs). IFNB-iPSCs were obtained by CRISPR/Cas9 editing of the previously generated iPSC line K7-4Lf. IFNB-iPSCs overexpressed IFNB RNA and produced a functionally active IFN-β. The cells displayed typical iPSC morphology and expressed pluripotency markers. Following spontaneous differentiation, IFNB-iPSCs formed embryoid bodies and upregulated endoderm, mesoderm, and some ectoderm markers. However, an upregulation of key neuroectoderm markers, PAX6 and LHX2, was compromised. A negative effect of IFN-β on iPSC neuroectoderm differentiation was confirmed in parental iPSCs differentiated in the presence of a recombinant IFN-β. The study describes new IFN-β-producing iPSC lines suitable for the generation of various types of IFN-β-producing cells for future experimental and clinical applications, and it unravels an inhibitory effect of IFN-β on stem cell neuroectoderm differentiation. Full article

Extrarenal teratoid Wilms’ tumor (TWT) is a variant of Wilms’ tumor with fewer than 30 cases reported in the literature. It comprises more than 50% heterologous tissue and presents a significant diagnostic challenge due to its complex histology. We report an unusual case of mediastinal teratoma with nephroblastomatous elements in an 8-year-old female. The patient presented with respiratory distress, fever, weight loss, and a large anterior mediastinal mass. Imaging revealed a heterogeneous tumor containing fat, fluid, and calcification, suggestive of a teratoma. Surgical resection confirmed a mature cystic teratoma with foci of nephroblastoma. Pathological analysis demonstrated a mixture of ectodermal, mesodermal, and endodermal tissues alongside nephroblastomatous components. Immunohistochemistry was positive for Wilms Tumor 1 and other relevant markers, confirming the diagnosis. The patient had an uneventful postoperative course and was discharged after three days. This case adds to the growing body of research on extrarenal TWT, particularly its occurrence in the mediastinum, a rare site for such tumors. A literature review highlighted that extrarenal TWT often affects children, typically presenting in the retroperitoneum or sacrococcygeal regions, with varying recurrence rates and long-term outcomes. This case underscores the importance of histopathological and immunohistochemical analysis in diagnosing TWT and differentiating it from other mediastinal tumors to ensure appropriate treatment planning, emphasizing the need for long-term follow-up due to the potential for recurrence or metastasis. This paper also provides an in-depth look at nephron development and nephrogenic rests, highlighting the structural and functional aspects of nephrogenesis and the factors that disrupt it in fetal kidneys. Full article

Thyroid gland diseases remain clinical challenges due to the lack of reliable in vitro models to examine molecular pathways of thyrocytes development, maturation, and functional maintenance. This study aimed to develop in vitro thyrocytes model using a stem cell culture, P19 embryonal carcinoma which requires no feeder layer, differentiation into mature and functional thyrocytes that allow molecular and genetic manipulation for studying thyroid diseases. The procedure utilizes Activin A and thyroid stimulating hormone (TSH) to first induce embryoid body endoderm formation enriched in thyrocyte progenitors. Following dissociating embryoid bodies, thyrocyte progenitors are plated in Matrigel as monolayer cultures that allows thyrocyte progenitors mature to functional thyrocytes. These thyrocytes further maturate to form follicle-like structures expressing and accumulating thyroglobulin that can be secreted into the medium upon TSH stimulation. Thyrocyte differentiation-maturation process is monitored by the expression of essential transcriptional factors and thyrocyte-specific functional genes. Further, the applicability of this system is validated by introducing a siRNA control. Following molecular manipulation, the system can still be guided to differentiate into mature and functional thyrocytes. This system spans a time frame of 14 days, suitable for detailed molecular studies to dissect pathways and molecular players in thyrocytes development and functional maintenance. Full article

The advent of induced pluripotent stem cell (iPSC) technology has brought about transformative advancements in regenerative medicine, offering novel avenues for disease modeling, drug testing, and cell-based therapies. Patient-specific iPSC-based treatments hold the promise of mitigating immune rejection risks. However, the intricacies and costs of producing autologous therapies present commercial challenges. The hair follicle is a multi-germ layered versatile cell source that can be harvested at any age. It is a rich source of keratinocytes, fibroblasts, multipotent stromal cells, and the newly defined Hair Follicle-Associated Pluripotent Stem Cells (HAP). It can also be obtained non-invasively and transported via regular mail channels, making it the ideal starting material for an autologous biobank. In this study, cryopreserved hair follicle-derived iPSC lines (HF-iPS) were established through integration-free vectors, encompassing a diverse cohort. These genetically stable lines exhibited robust expression of pluripotency markers, and showcased tri-lineage differentiation potential. The HF-iPSCs effectively differentiated into double-positive cKIT⁺/CXCR4⁺ definitive endoderm cells and NKX6.1⁺/PDX1⁺ pancreatic progenitor cells, affirming their pluripotent attributes. We anticipate that the use of plucked hair follicles as an accessible, non-invasive cell source to obtain patient cells, in conjunction with the use of episomal vectors for reprogramming, will improve the future generation of clinically applicable pancreatic progenitor cells for the treatment of Type I Diabetes. Full article

Previously, we successfully established a highly functional, three-dimensional hepatocyte-like cell (3D-HLC) model from adipose-derived mesenchymal stem cells (ADSCs) via a three-step differentiation protocol. The aim of the present study was to investigate whether generating hepatocyte-like organoids (H-organoids) by adding endothelial cells further improved the liver-like functionality of 3D-HLCs and to assess H-organoids’ immunogenicity properties. Genes representing liver maturation and function were detected by quantitative reverse transcription–PCR analysis. The expression of hepatic maturation proteins was measured using immunofluorescence staining. Cytochrome P (CYP)450 metabolism activity and ammonia metabolism tests were used to assess liver function. H-organoids were successfully established by adding human umbilical vein endothelial cells at the beginning of the definitive endoderm stage in our 3D differentiation protocol. The gene expression of alpha-1 antitrypsin, carbamoyl–phosphate synthase 1, and apolipoprotein E, which represent liver maturation state and function, was higher in H-organoids than non-organoid 3D-HLCs. H-organoids possessed higher CYP3A4 metabolism activity and comparable ammonia metabolism capacity than 3D-HLCs. Moreover, although H-organoids expressed human leukocyte antigen class I, they expressed little human leukocyte antigen class II, cluster of differentiation (CD)40, CD80, CD86, and programmed cell death ligand 1, suggesting their immunogenicity properties were not significantly upregulated during differentiation from ADSCs. In conclusion, we successfully established an H-organoid model with higher liver-like functionality than previously established 3D-HLCs and comparable immunogenicity to ADSCs. Full article

Embryonic stem cells (ESCs) favor glycolysis over oxidative phosphorylation for energy production, and glycolytic metabolism is critical for pluripotency establishment, maintenance, and exit. However, an understanding of how glycolysis regulates the self-renewal and differentiation of ESCs remains elusive. Here, we demonstrated that protein lactylation, regulated by intracellular lactate, contributes to the self-renewal of ESCs. We further showed that Esrrb, an orphan nuclear receptor involved in pluripotency maintenance and extraembryonic endoderm stem cell (XEN) differentiation, is lactylated on K228 and K232. The lactylation of Esrrb enhances its activity in promoting ESC self-renewal in the absence of the LIF and XEN differentiation of ESCs by increasing its binding at target genes. Our studies reveal the importance of protein lactylation in the self-renewal and XEN differentiation of ESCs, and the underlying mechanism of glycolytic metabolism regulating cell fate choice. Full article