A novel mutation of SATB2 inhibits odontogenesis of human dental pulp stem cells through Wnt/β-catenin signaling pathway

Human colon organoid differentiation from induced pluripotent stem cells using an improved method

The colonic epithelium plays a crucial role in gastrointestinal homeostasis, and colon organoids enable investigation into the molecular mechanisms underlying colonic physiology. However, the method for differentiating induced pluripotent stem cells (iPSCs) into human colon organoids (HCOs) is not necessarily standardized, and studies using HCOs are limited. This study refines the differentiation of HCOs by comparing two protocols reported in Cell Stem Cell and Nature Medicine journals. The former protocol, which uses transient bone morphogenetic protein 2 (BMP2) signaling activation, demonstrated superior efficacy in upregulating colon-specific markers. Additionally, adenovirus-mediated transduction of the transcription factors HOXD13 or SATB2 during hindgut endoderm development, together with BMP2 treatment, enhanced colonic identity, suggesting improved colonic maturation. This optimized protocol advances the generation of mature HCOs, offering a better model for investigating colonic epithelial biology and pathology.

Immunohistochemical Expression of MDM2, Bcl-2, SATB2 and Ki-67 in Histological Variants of Unicystic Ameloblastoma

AIM

To characterize the immunohistochemical expression of MDM2, Bcl-2, SATB2 and Ki-67 in histological variants of unicystic ameloblastoma (UA).

METHODOLOGY

Following the ethical approval, forty (40) patients with unicystic ameloblastoma were retrieved from the archives and subjected to immunohistochemistry (IHC). Sociodemographic and clinical data were also retrieved. The results were entered into a Microsoft Excel spreadsheet and analyzed using SPSS software.

RESULTS

Human tooth germs, which served as the control, showed moderate expression of Bcl-2 and MDM2 with slight proliferative activity in ameloblasts and moderate expression of SATB2 in ectomesenchyme and odontoblasts. Luminal UA (Type 1) showed low Ki-67 index and negative to mild Bcl-2 and MDM2 expression, whilst Type 1.2 (luminal and intraluminal), Type 1.2.3 (luminal, intraluminal and mural), and Type 1.3 (luminal and mural), including the recurrent cases, showed moderate to intense expression with high mean Ki-67 index. The difference between the study groups was statistically significant (p value < 0.001). No expression of SATB2 was noted in any histological variant of UA. Furthermore, no significant differences were noted in age, gender, site and location between the groups.

CONCLUSION

In contrast to luminal variant of UA, mural±intraluminal variants and recurrent cases demonstrate higher expression of Bcl-2 and MDM2 with higher mean Ki-67 index. It may thus be prudent to provide aggressive treatment for cases, not just with mural follicles but also for the patients with intraluminal plexiform proliferation, to prevent recurrence and improve patient outcomes.

Mechanism and application of feedback loops formed by mechanotransduction and histone modifications

Mechanical stimulation is the key physical factor in cell environment. Mechanotransduction acts as a fundamental regulator of cell behavior, regulating cell proliferation, differentiation, apoptosis, and exhibiting specific signature alterations during the pathological process. As research continues, the role of epigenetic science in mechanotransduction is attracting attention. However, the molecular mechanism of the synergistic effect between mechanotransduction and epigenetics in physiological and pathological processes has not been clarified. We focus on how histone modifications, as important components of epigenetics, are coordinated with multiple signaling pathways to control cell fate and disease progression. Specifically, we propose that histone modifications can form regulatory feedback loops with signaling pathways, that is, histone modifications can not only serve as downstream regulators of signaling pathways for target gene transcription but also provide feedback to regulate signaling pathways. Mechanotransduction and epigenetic changes could be potential markers and therapeutic targets in clinical practice.

Effects of different signaling pathways on odontogenic differentiation of dental pulp stem cells: a review

Dental pulp stem cells (DPSCs) are a type of mesenchymal stem cells that can differentiate into odontoblast-like cells and protect the pulp. The differentiation of DPSCs can be influenced by biomaterials or growth factors that activate different signaling pathways in vitro or in vivo. In this review, we summarized six major pathways involved in the odontogenic differentiation of DPSCs, Wnt signaling pathways, Smad signaling pathways, MAPK signaling pathways, NF-kB signaling pathways, PI3K/AKT/mTOR signaling pathways, and Notch signaling pathways. Various factors can influence the odontogenic differentiation of DPSCs through one or more signaling pathways. By understanding the interactions between these signaling pathways, we can expand our knowledge of the mechanisms underlying the regeneration of the pulp-dentin complex.

Lysine-specific demethylase 7A (KDM7A): A potential target for disease therapy

Histone demethylation is a kind of epigenetic modification mediated by a variety of enzymes and participates in regulating multiple physiological and pathological events. Lysine-specific demethylase 7A is a kind of α-ketoglutarate- and Fe(II)-dependent demethylase belonging to the PHF2/8 subfamily of the JmjC demethylases. KDM7A is mainly localized in the nucleus and contributes to transcriptional activation via removing mono- and di-methyl groups from the lysine residues 9 and 27 of Histone H3. Mounting studies support that KDM7A is not only necessary for normal embryonic, neural, and skeletal development, but also associated with cancer, inflammation, osteoporosis, and other diseases. Herein, the structure of KDM7A is described by comparing the similarities and differences of its amino acid sequences of KDM7A and other Histone demethylases; the functions of KDM7A in homeostasis and dyshomeostasis are summarized via documenting its content and related signaling; the currently known KDM7A-specific inhibitors and their structural relationship are listed based on their structure optimization and pharmacological activities; and the challenges and opportunities in exploring functions and developing targeted agents of KDM7A are also prospected via presenting encountered problems and potential solutions, which will provide an insight in functional exploration and drug discovery for KDM7A-related diseases.

The odontoblastic differentiation of dental mesenchymal stem cells: molecular regulation mechanism and related genetic syndromes

Dental mesenchymal stem cells (DMSCs) are multipotent progenitor cells that can differentiate into multiple lineages including odontoblasts, osteoblasts, chondrocytes, neural cells, myocytes, cardiomyocytes, adipocytes, endothelial cells, melanocytes, and hepatocytes. Odontoblastic differentiation of DMSCs is pivotal in dentinogenesis, a delicate and dynamic process regulated at the molecular level by signaling pathways, transcription factors, and posttranscriptional and epigenetic regulation. Mutations or dysregulation of related genes may contribute to genetic diseases with dentin defects caused by impaired odontoblastic differentiation, including tricho-dento-osseous (TDO) syndrome, X-linked hypophosphatemic rickets (XLH), Raine syndrome (RS), hypophosphatasia (HPP), Schimke immuno-osseous dysplasia (SIOD), and Elsahy-Waters syndrome (EWS). Herein, recent progress in the molecular regulation of the odontoblastic differentiation of DMSCs is summarized. In addition, genetic syndromes associated with disorders of odontoblastic differentiation of DMSCs are discussed. An improved understanding of the molecular regulation and related genetic syndromes may help clinicians better understand the etiology and pathogenesis of dentin lesions in systematic diseases and identify novel treatment targets.

Periodontal ligament fibroblasts-derived exosomes induced by PGE2 inhibit human periodontal ligament stem cells osteogenic differentiation via activating miR-34c-5p/SATB2/ERK

Several studies have confirmed that exosomes containing microRNAs (miRNAs) from the aseptic inflammatory microenvironment play an important role in bone remodeling. But the mechanism that induces changes in the osteogenic ability of periodontal ligament stem cells (PDLSCs) is still unclear. In the present study, the osteogenic function of periodontal ligament fibroblasts-derived exosomes induced by PGE₂ on PDLSCs was detected by real-time PCR, alizarin red assay and alkaline phosphatase staining. High-throughput miRNAs sequencing was used to reveal that miR-34c-5p in exosomes-PGE₂ was upregulated compared it in exosomes-normal. Real-time PCR and western blotting assay verified that overexpression of miR-34c-5p inhibited osteogenic differentiation, and reduced phosphorylation of ERK1/2. In addition, dual-luciferase reporter assay revealed that miR-34c-5p targeted special AT-rich sequence-binding protein 2 (SATB2). It was shown that exosomal miR-34c-5p inhibited osteogenic differentiation of PDLSCs via SATB2/ERK pathway.