Search Results (184)

Hair follicles (HFs) are highly accessible mini-organs that house diverse somatic and stem cell populations with broad therapeutic potential. In this study, we investigate the untapped utility of plucked HFs as a non-invasive tissue source for regenerative medicine. We demonstrate the successful isolation and expansion of keratinocytes and mesenchymal stem cells (MSCs) from plucked follicles using an enzyme-free explant culture method. HF-derived keratinocytes retained their epithelial identity and were efficiently reprogrammed into induced pluripotent stem cells (iPSCs). These iPSCs were further directed toward definitive endoderm and pancreatic progenitor fates, confirming their robust autologous regenerative capacity. Flow cytometric analysis of HF-MSCs validated a characteristic mesenchymal profile, and these cells exhibited classical trilineage plasticity alongside the ability to differentiate into dopaminergic neural progenitors. Furthermore, proteomic and vesicular characterization of the autologous HF secretome (aHFS) revealed a rich enrichment of regenerative cytokines and exosomes. The aHFS demonstrated potent wound-healing bioactivity in vitro. Collectively, these findings establish the plucked hair follicle as a highly practical, scalable source for both cell-based and cell-free therapies, highlighting the clinical value of early-stage follicular biobanking for personalized medicine. Full article

The development of the esophagus and trachea following the septation of the anterior foregut is a highly regulated process involving bidirectional communication between the endoderm and mesoderm. Signaling pathways such as the Bone Morphogenetic Protein family, Wnt/β-catenin, Sonic Hedgehog, and Fibroblast Growth Factor family mediate this complex crosstalk to induce the dorsal-ventral patterning of the anterior foregut as well as lineage specification. Even though the mechanisms are not fully understood, dysregulation of signaling pathways may lead to congenital malformations such as tracheomalacia, laryngeal–tracheal clefts and multiple types of esophageal atresia with/without tracheoesophageal fistula (EA/TEF). Human induced pluripotent stem cells (iPSCs) provide a robust in vitro platform to monitor the normal and abnormal development of esophagus and trachea and to understand the roles of the endoderm and mesoderm during anterior foregut development. Recent studies have demonstrated that direct differentiation of iPSCs into epithelial and mesenchymal lineages can recapitulate the key stages of foregut development. In this regard, in the current paper, we review the signaling pathways involved in the development of organs deriving from the anterior foregut as well as the roles of the endoderm and mesoderm revealed by previous studies. Furthermore, we discuss the use of iPSCs as a valuable model for investigating the bidirectional communications between the endoderm and mesoderm, which can broaden our knowledge and understanding of the critical mechanisms leading to normal and abnormal development of the esophagus and trachea. Full article

Human-induced pluripotent stem cells (hiPSCs) have an innate ability to differentiate into the three germ layers: the ectoderm, endoderm, and mesoderm. By using targeted differentiation methods and carefully controlling growth factors, morphogens, and signaling modulators, hiPSCs can be guided to develop into specific lineage cell types. For clinical applications of hiPSCs and their derivatives, it is crucial to use xenogen-free, chemically defined culture media, reagents, recombinant growth factors, morphogens, and extracellular matrix (ECM) scaffolds. One major obstacle is the widespread use of Matrigel as an hiPSC culture matrix. Matrigel, derived from Engelbreth–Holm–Swarm (EHS) mouse sarcoma, is an extract of basement membrane material with a complex, poorly defined, and variable composition. It also exhibits batch-to-batch variability in mechanical and biochemical properties and is difficult to modify, which limits its rational use in the production of therapeutic cells and organoids. Synthetic ECM matrices and scaffolds offer a promising alternative because they can have a fully defined composition, highly tunable physical properties, surface modifications, and functionalization with recombinant signaling peptides and growth factors. This provides a suitable microenvironment for hiPSC culture and the directed differentiation towards lineage-specific cells and organoid development, and can be used in clinical-grade tissue transplantation and regenerative medicine. Full article

The liver is the central organ in metabolism; however, modeling hepatic diseases remains limited by current experimental models. Animal models frequently fail to predict human liver physiology, while primary hepatocytes rapidly dedifferentiate in culture. We performed comprehensive transcriptomic profiling of induced pluripotent stem cells (iPSCs) differentiation into hepatocyte-like cells (HLCs) under two-dimensional (2D) and three-dimensional (3D) culture conditions. RNA sequencing analysis revealed the sequential activation of lineage-specific markers across major developmental stages: definitive endoderm (FOXA2, SOX17, CXCR4, CER1, GATA4), posterior foregut (PROX1, GATA6), and hepatoblasts (HNF4A, AFP). Comparative analysis demonstrated a markedly enhanced hepatic gene expression of 3D organoids, as demonstrated by a 33-fold increase in HNF4A expression and elevated levels of mature hepatocyte markers, including ALB, SERPINA1, and UGT2B15. However, the 3D cultures retained fetal characteristics (290-fold higher AFP expression) and exhibited significantly impaired metabolic function, with CYP3A4 expression levels reduced by 2000-fold compared to the adult human liver. This partial maturation was further supported by a moderate correlation with adult liver tissue (ρ = 0.57). We demonstrated high reproducibility across five biologically distinct iPSCs lines, including those derived from patients with rare monogenic disorders. The establishment of quantitative benchmarks provides a crucial tool for standardizing in vitro liver models. Furthermore, we delineate the specific limitations of the current model, highlighting the need for further protocol optimization to enhance metabolic maturation and P450 enzyme activity. Functional validation of metabolic activity (CYP enzyme assays, albumin secretion) was not performed; therefore, conclusions regarding hepatocyte functionality are based on transcriptomic evidence. Full article

Background: Germ cell tumors are benign or malignant tumors that originate from the human embryo’s primordial germ cells. This study aims to conduct a retrospective analysis of germ cell tumors followed up at our institution, including their epidemiological data, treatment, and prognosis. Patients and Methods: Ninety-three cases were included and retrospectively evaluated for socio-demographic features, clinical data, presenting symptoms, histopathological findings, localization, staging, treatment protocol, and survival analysis. Results: Patients were diagnosed between 10 days and 17 years 10 months (median 27.2 months); 37 (40.7%) were male, 54 (59.3%) female. The tumors were located in the sacrococcygeal region (33.3%), ovaries (26.8%), testes (25.8%), abdomen (7.5%), CNS (2.1%), liver, adrenal gland, anterior mediastinum, and spine. Thirty-nine lesions were benign, and 54 were malignant. Mature cystic teratomas (40.8%), endodermal sinus tumors (28.0%), mixed germ cell tumors (12.9%), immature teratomas (9.7%), germinoma (6.5%), gonadoblastoma (1.1%), and choriocarcinoma (1.1%) were the different types of histology. We observed metastases in 17 malignant cases, with the lungs being the most commonly affected (10.7%). Stages I, II, III, and IV included 16, 17, 11, and 10 cases, respectively. Survival rates for all cases were 95.8%, and for malignant tumors, they were 92.7%. For malignant cases, the event-free survival rate was 84.2%. Conclusions: The findings provide comprehensive epidemiological and clinical data on germ cell tumors, enhancing understanding of their distribution, treatment outcomes, and prognosis. The high survival rates observed highlight the effectiveness of current treatment protocols, as well as the importance of early diagnosis and appropriate management. Full article

Sinonasal inverted papilloma (SNIP) is a benign neoplasm derived from the Schneiderian membrane and the endoderm of the ciliated respiratory epithelium of the nasal cavity and paranasal sinuses. SNIP is uncommon and typically found between the fourth and seventh decades of life, with men being more frequently affected. The medical significance of this benign neoplasm lies in its potential to cause local tissue destruction, tendency toward malignancy, and high recurrence rate. This study describes the histology of the nasosinusal mucosa and histological characteristics of SNIP, as well as its clinical manifestations and treatment. We also describe findings in the development of SNIP such as chronic inflammation and environmental factors. Additionally, we describe the association between cases positive for the human papillomavirus (HPV) and progression to malignancy and recurrence. This analysis includes the tumor microenvironment, encompassing the infiltration of immune cells such as CD4+ and CD8+ lymphocytes, macrophage polarization, and increases in certain metalloproteinases (MMP-2 and MMP-9). Finally, we address epigenetic alterations associated with HPV infection. Full article

Oct4 is well established as a core regulator of pluripotency, yet emerging evidence points to an additional role in lineage specification during the exit from the pluripotent state. Although Oct4 expression has been observed in early mesodermal progenitors, its precise function in this developmental context remains unclear. To investigate this, we employed embryoid bodies (EBs) as a model of spontaneous differentiation that recapitulates key aspects of early embryonic development in vitro. In accordance with previous studies, reporter assay revealed a distinct temporal pattern characterized by the strong, transient co-expression of Oct4 and the early mesoderm-specifying marker gene Brachyury within a narrow developmental window, consistent with the Oct4 role in early mesodermal progenitors. We further examined the consequences of the Oct4 loss at early stages of this differentiation. Conditional knockout of the Oct4 gene resulted in a significant reduction in EB size and accumulation of cells in the G0/G1 phase, indicating a critical requirement for Oct4 in maintaining cell proliferation. Despite this defect, cells retained the ability to initiate multilineage differentiation, albeit with reduced expression of Brachyury and elevated expression of endodermal markers FoxA2 and Sox17. Interestingly, the formation of beating cardiomyocyte-like structures was also diminished following Oct4 loss and could not be rescued by simply increasing cell numbers. Taken together, these findings highlight an important Oct4 function in mesodermal differentiation, mediated through the maintenance of proliferative capacity of early mesodermal progenitors. Full article

LATERAL ORGAN BOUNDARIES DOMAIN (LBD) genes encode plant specific transcription factors that regulate various developmental processes and abiotic stresses. In this study, we characterized RrLBD40 from Rosa rugosa as a nucleus-localized transcription factor harboring a conserved LOB domain. We generated RrLBD40-overexpressing Rosa rugosa plants and compared them with control plants in terms of physiological indices, root architecture, and Na⁺ homeostasis. The results showed that RrLBD40 overexpression significantly increased peroxidase activity and reduced malondialdehyde content in the roots, indicating enhanced antioxidant capacity under salt stress. Furthermore, RrLBD40 overexpression markedly promoted root growth and development, a similar phenotype consistently observed in RrLBD40 transgenic Arabidopsis plants. Propidium iodide staining and analysis of the Na⁺ flux rates of root tips revealed that the barrier function of the Casparian strip was compromised in both the RrLBD40-overexpression and control plants under salt stress. This disruption of endodermal selectivity permitted Na⁺ influx into the vascular cylinder. Furthermore, neither plants exhibited significant Na⁺ efflux capacity. Taken together, these findings demonstrate that RrLBD40 enhances salt tolerance in Rosa rugosa by primarily promoting root growth and development, rather than modulating Na⁺ homeostasis. Full article

Pharyngeal cartilage, derived from neural crest cells (NCCs), undergoes complex morphogenesis driven by signals from the pharyngeal endoderm. However, the molecular mechanisms governing NCC proliferation and differentiation in response to endoderm-derived signals remain poorly understood. Here, we investigate the role of klf5a, a zinc-finger transcription factor expressed in pharyngeal endodermal pouches, in zebrafish pharyngeal cartilage development. Knockdown of klf5a using morpholinos minimally affected cranial NCC specification and migration but significantly impaired their proliferation and differentiation in the pharyngeal region. Notably, klf5a deficiency reduced expression of fgfbp2b, a modulator of FGF signaling, in the pharyngeal endoderm. Co-injection of klf5a mRNA rescued the cartilage defects, but injection of fgfbp2b mRNA alone failed to restore normal cartilage morphogenesis, suggesting that fgfbp2b is not the sole mediator of klf5a’s effects. These findings indicate that klf5a regulates endodermal signaling to direct NCC-derived pharyngeal cartilage formation, likely through multiple downstream targets including fgfbp2b. This study provides insights into the complex molecular network underlying craniofacial development and highlights potential therapeutic targets for craniofacial disorders. Full article

This study established an in vitro model to investigate peri- and post-implantation embryo development under heat shock conditions. In Experiment 1, we compared the gene expression profiles of the three germ layers in in vivo mouse embryos with those of mEBs derived from mouse embryonic stem cells. mEBs (Days 1–5) closely resembled developing E5.5–E6.5 embryos, expressing key germ layer markers: nestin (ectoderm), flk-1 (mesoderm), and ttr (endoderm). In Experiment 2, mEBs were randomly allocated to one of the following treatments: a control group (37 °C) or a heat shock group (39 °C or 41 °C) for 12 h or 24 h. Timing of germ layer marker expression, including ttr, was delayed by 1–2 days in the heat-shocked groups compared with the control group. Morphological analysis of mEBs revealed that the peripheral cell layer exhibited signs of disassembly or degeneration and became increasingly apoptotic under heat shock conditions. Additionally, these mEBs showed increased expression of heat shock proteins 70 and 72 in response to elevated temperatures and prolonged heat shock durations. Mouse EBs closely mimic in vivo-developing embryos in their germ layer marker expression profiles. In vitro heat shock delays germ layer marker gene expression and induces heat shock protein 72 expression in mEBs. Full article

Medullary thyroid carcinoma (MTC) is a thyroid tumor with neuroendocrine properties purportedly derived from C-cells. The biochemical activity of medullary thyroid carcinoma includes the production of calcitonin and carcinoembryonic antigen, which are sensitive tumor markers, facilitating diagnosis, follow-up, and prognostication. Calcitonin-negative medullary thyroid carcinoma is a rare, poorly understood primary neuroendocrine carcinoma of the thyroid characterized by classic medullary thyroid carcinoma morphology without raised serum calcitonin and with or without the expression of calcitonin detected by immunohistochemistry. Previous studies reported that C-cells were derived from the neural crest; however, more recently, C-cells have been indisputably shown to be derived from the pharyngeal endoderm and ultimobranchial bodies. Ultimobranchial body (UBB) remnants can persist in the thyroid and express p63, but their function is poorly understood. Some have postulated that ultimobranchial bodies may be the “stem” cell of the thyroid and may be precursors for thyroid tumors, particularly mixed tumors with follicular and medullary components. We present a unique case of calcitonin-negative MTC in a 58-year-old male arising in an inflamed and fibrotic thyroid with numerous scattered ultimobranchial body remnants and concomitant C-cell hyperplasia/medullary microcarcinoma (CCH/MMC). The ultimobranchial body remnants, C-cell hyperplasia, and medullary thyroid carcinoma were MTC classifier positive according to ThyroSeq^®. The areas representing CCH/MMC expressed calcitonin by IHC while the main MTC tumor was negative. An additional unique feature was an area demonstrating a “mixed” C-cell/thyroid follicular epithelial phenotype. In this review we review the possible etiologies of calcitonin-negative MTC, the possibility of a neoplastic sequential progression from ultimobranchial bodies to CCH/MMC to medullary thyroid carcinoma with the individual elements (UBB, CCH/MMC, MTC) demonstrated in this thyroid, and previous postulations that ultimobranchial bodies may be the source of some follicular thyroid cancers, medullary thyroid cancers, and mixed tumors of medullary and follicular epithelial types. Full article

MicroRNA (miRNA), as a key post-transcriptional regulatory factor, plays a crucial role in embryonic development. The coordination of endoderm cell convergence and cardiac precursor cell (CPC) migration is critical for cardiac tube fusion. Defects in endoderm can impair the normal migration of CPCs towards the midline, leading to cardia bifida. Although the role of the microRNA-183 family (miR-183, miR-96 and miR-182) in cardiovascular diseases has been reported, the mechanism by which they regulate early heart development remains unclear. In this study, we used zebrafish as a model to elucidate the roles of the microRNA-183 family in early heart development. miRNA mimics were injected into Tg (cmlc2: eGFP) and Tg (sox17: eGFP) transgenic embryos to overexpress the miR-183 family. The results showed that, at 36 hpf, single or co-injection of miR-183/96/182 mimics caused defects in endoderm convergence, with a hole in the endoderm, and a significant down-regulation of the endoderm marker gene sox32. Additionally, embryos with single or co-injection of miR-183/96/182 mimics exhibited cardia bifida and tail blisters, with significantly down-regulated expression levels of genes related to heart development, including cmlc2, vmhc, amhc, nppa, gata4, gata5, nkx2.5, bmp2b, and bmp4. The phenotype caused by overexpression of the miR-183 family is highly consistent with loss of the sphingosine 1-phosphate receptor S1Pr2. Bioinformatics analysis result found that miR-183 can bind to 3′-UTR of the s1pr2 to regulate its expression; overexpression of miR-183 led to a significant decrease in the expression of the s1pr2 gene. Dual luciferase assay results suggest that s1pr2 is a bona fide target of miR-183. In summary, the miR-183 family regulates endoderm convergence and cardiac precursor cell migration via the S1Pr2 signaling pathway. This study reveals that the miR-183 family is a key regulatory factor in endoderm convergence and cardiac precursor cell migration during the early zebrafish development, elucidating the molecular mechanisms underlying early cardiac precursor cell and endoderm cell movement. Full article

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

Nepenthes L. species (tropical pitcher plants) are a classic example of carnivorous plants. The Nepenthes traps are highly specialized pitchers with a zoned structure. On the outer surface of the pitcher, there are nectaries and various types of trichomes, including glandular trichomes. The main aim of our study was to examine these glandular trichome structures and check the distribution of the homogalacturonans (HGs) and hemicelluloses in the cell wall of trichome cells. The structure of Nepenthes bicalcarata Hook. f. and Nepenthes albomarginata T.Lobb ex Lindl. trichomes was analyzed using light and electron microscopy. The antibodies were used against the wall components [anti-pectic homogalacturonans (HGs): JIM5 (low methylesterified HGs), LM19 (low methylesterified HGs), CCRC-M38 (a fully de-esterified HGs), JIM7 (highly esterified HGs), LM20 (esterified HGs), LM5 (galactan) and anti-hemicelluloses: LM25 (xyloglucan), LM15 (galactoxyloglucan), CCRC-M138 (xylan), and LM10 antibody (xylan)]. The localization of the examined compounds was determined using immunohistochemistry techniques. The presence of endodermal and transfer cells supports the idea that peltate trichomes actively transport solutes. Also, the presence of pectic homogalacturonans and hydrophilic hemicelluloses indicates that water or aqueous solutions are transported through the trichomes’ cell walls. Our study supports the idea that these trichomes may act as hydathodes or hydropotes. Full article