Somatostatin (SST) is an inhibitory polypeptide hormone that plays an important role in a variety of biological processes. Somatostatin receptor 2 (SSTR2) is the most widely expressed somatostatin receptor. However, the specific cell types expressing Sstr2 in the tissues have not been investigated. In this study, we detected the expression pattern of SSTR2 protein in mouse at different development stages, including the embryonic 15.5 days and the postnatal 1, 7, 15 days as well as 3 and 6 months, by multicolour immunofluorescence analyses. We found that Sstr2 was expressed in some specific cells types of several tissues, including the neuronal cells and astrocytes in the brain, the mesenchymal cells, the hematopoietic cells, the early hematopoietic stem cells, and the B cells in the bone marrow, the macrophages, the type Ⅱ alveolar epithelial cells, and the airway ciliated cells in the lung, the epithelial cells and the neuronal cells in the intestine, the hair follicle cells, the gastric epithelial cells, the hematopoietic stem cells and the nerve fibre in the spleen, and the tubular epithelial cells in the kidney. This study identified the specific cell types expressing Sstr2 in mouse at different developmental stages, providing new insights into the physiological function of SST and SSTR2 in several cell types.
Mice ; Animals ; Receptors, Somatostatin/metabolism* ; Hematopoietic Stem Cells/metabolism* ; Epithelial Cells

To investigate the protective effect and the potential mechanism of leonurine(Leo) against erastin-induced ferroptosis in human renal tubular epithelial cells(HK-2 cells), an in vitro erastin-induced ferroptosis model was constructed to detect the cell viability as well as the expressions of ferroptosis-related indexes and signaling pathway-related proteins. HK-2 cells were cultured in vitro, and the effects of Leo on the viability of HK-2 cells at 10, 20, 40, 60, 80 and 100 μmol·L~(-1) were examined by CCK-8 assay to determine the safe dose range of Leo administration. A ferroptosis cell model was induced by erastin, a common ferroptosis inducer, and the appropriate concentrations were screened. CCK-8 assay was used to detect the effects of Leo(20, 40, 80 μmol·L~(-1)) and positive drug ferrostatin-1(Fer-1, 1, 2 μmol·L~(-1)) on the viability of ferroptosis model cells, and the changes of cell morphology were observed by phase contrast microscopy. Then, the optimal concentration of Leo was obtained by Western blot for nuclear factor erythroid 2-related factor 2(Nrf2) activation, and transmission electron microscope was further used to detect the characteristic microscopic morphological changes during ferroptosis. Flow cytometry was performed to detect reactive oxygen species(ROS), and the level of glutathione(GSH) was measured using a GSH assay kit. The expressions of glutathione peroxidase 4(GPX4), p62, and heme oxygenase 1(HO-1) in each group were quantified by Western blot. RESULTS:: showed that Leo had no side effects on the viability of normal HK-2 cells in the concentration range of 10-100 μmol·L~(-1). The viability of HK-2 cells decreased as the concentration of erastin increased, and 5 μmol·L~(-1) erastin significantly induced ferroptosis in the cells. Compared with the model group, Leo dose-dependently increased cell via-bility and improved cell morphology, and 80 μmol·L~(-1) Leo promoted the translocation of Nrf2 from the cytoplasm to the nucleus. Further studies revealed that Leo remarkably alleviated the characteristic microstructural damage of ferroptosis cells caused by erastin, inhibited the release of intracellular ROS, elevated GSH and GPX4, promoted the nuclear translocation of Nrf2, and significantly upregulated the expression of p62 and HO-1 proteins. In conclusion, Leo exerted a protective effect on erastin-induced ferroptosis in HK-2 cells, which might be associated with its anti-oxidative stress by activating p62/Nrf2/HO-1 signaling pathway.
Humans ; Ferroptosis ; Reactive Oxygen Species/metabolism* ; NF-E2-Related Factor 2/metabolism* ; Sincalide/pharmacology* ; Signal Transduction ; Epithelial Cells/metabolism* ; Glutathione

Mycoplasma pneumoniae is the most common pathogen of respiratory tract infection in children and adults. Clinical observation shows that M. pneumoniae infection can cause massive mucus secretion in the respiratory tract, which makes the breathing of patients difficult. Studies have shown that M. pneumoniae infection can cause massive secretion of mucin 5AC (MUC5AC). Adhesin P1 plays an important role in the pathogenesis of M. pneumoniae infection by mediating the adhesion of pathogens to host cells, and the C-terminal residues of P1 (P1-C) are immunogenic. This study investigated the molecular mechanism of Wnt/β-catenin signaling pathway inhibitor Dickkopf-1 (DKK1) in the secretion of MUC5AC in mouse airway epithelial cells (MAECs) induced by P1-C. Scanning electron microscope and hematoxylin-eosin staining were used to observe the effect of P1-C on mucus secretion of MAECs. Protein chip was used to detect the secretion of cytokines and analyse the enrichment of related signaling pathways induced by P1-C in MAECs. Periodic acid schiff stain (PAS) staining, Tunel staining and Masson staining were used to detect the damage of the lungs of mouse exposed to P1-C. Immunohistochemistry was used to detect the secretion of MUC5AC expression, and Western blotting was used to reveal the molecular mechanism of DKK1-regulated secretion of MUC5AC induced by P1-C protein in MACES. The results showed that P1-C induced the massive secretion of mucus and inflammatory factors in MAECs. During P1-C infection, DKK1 down-regulated janus kinase 2 (JAK2), phosphorylation signaling and transcription activator 1 (p-STAT1) and phosphorylation signaling and activator of transcription 3 (p-STAT3) expression. Overexpression of DKK1 significantly up-regulated the expression of MUC5AC repressor transcription factor fork-head box protein A2 (FOXA2). At the same time, the expression of MUC5AC induced by P1-C was inhibited significantly. It is speculated that DKK1 can effectively reduce the secretion of MUC5AC in MAECs induced by P1-C by inhibiting the JAK/STAT1-STAT3 signaling pathway and up-regulating the expression of FOXA2.
Animals ; Mice ; Epithelial Cells ; Lung ; Mucin 5AC/metabolism* ; Mycoplasma pneumoniae/metabolism* ; Signal Transduction

Olfactory epithelium, which detects and transmits odor signals, is critical for the function of olfactory system. Olfactory epithelium is able to recover spontaneously after injury under normal circumstances, but this ability is dampened in certain diseases or senility, which causes olfactory dysfunction. The olfactory epithelium consists of basal cells, sustentacular cells and olfactory sensory neurons. In order to develop an olfactory epithelial organoid containing multiple olfactory cell types in vitro, we used three-dimensional culture model and small molecules screening. This organoid system consists of horizontal basal-like cells, globose basal-like cells, sustentacular-like cells and olfactory sensory neurons-like cells. Through statistical analysis of clone diameter, immunofluorescence staining and qPCR detection of the expression level of related marker genes. We identified a series of growth factors and small molecule compounds that affected the proliferation, composition and gene expression of the organoids. CHIR-99021, an activator of Wnt signaling pathway, increased the colony formation and proliferation rate of olfactory epithelial organoids and the expression level of marker genes of olfactory sensory neurons-like cells. In addition, each factor in the culture system increased the proportion of c-Kit-positive globose basal-like cell colonies in organoids. Moreover, EGF and vitamin C were both beneficial to the expression of horizontal basal-like cell marker genes in organoids. The established olfactory epithelial organoid system mimicked the process of olfactory epithelial stem cells differentiating into various olfactory epithelial cell types, thus providing a research model for studying olfactory epithelial tissue regeneration, the pathological mechanism of olfactory dysfunction and drug screening for olfactory dysfunction treatment.
Humans ; Olfactory Mucosa/metabolism* ; Epithelial Cells ; Organoids/metabolism* ; Olfaction Disorders/metabolism*

Objective: To investigate the effect of nuclear factor erythroid 2-related factor 2 (Nrf2) in the alteration of tight junction protein expression in choroid plexus epithelial cells created by lanthanum-activated matrix metalloproteinase 9 (MMP9) . Methods: In October 2020, immortalized rat choroid plexus epithelial cell line (Z310) cells were used as the blood-cerebrospinal fluid barrier in vitro, and were divided into control group and 0.125, 0.25, 0.5 mmol/L lanthanum chloride (LaCl(3)) treatment group. After treating Z310 cells with different concentrations of LaCl(3) for 24 hours, the morphological changes of Z310 cells were observed under inverted microscope, the protein expression levels of MMP9, occludin and zonula occludens-1 (ZO-1) were observed by cellular immunofluorescence method, and the protein expression levels of MMP9, tissue inhibitors of metalloproteinase1 (TIMP1) , occludin, ZO-1 and Nrf2 were detected by Western blotting. The level of reactive oxygen species (ROS) in cells was detected by flow cytometry. Results: Compared with the control group, Z310 cells in the LaCl(3) treatment group were smaller in size, with fewer intercellular junctions, and more dead cells and cell fragments. The expression level of MMP9 protein in cells treated with 0.25 and 0.5 mmol/L LaCl(3) was significantly higher than that in the control group (P<0.05) , and the expression level of TIMP1 and tight junction proteins occudin and ZO-1 was significantly lower than that in the control group (P<0.05) . Compared with the control group, the ROS production level in the 0.25, 0.5 mmol/L LaCl(3) treatment group was significantly increased (P<0.05) , and the Nrf2 protein expression level in the 0.125, 0.25, 0.5 mmol/L LaCl(3) treatment group was significantly decreased (P<0.05) . Conclusion: Lanthanum may increase the level of ROS in cells by down regulating the expression of Nrf2, thus activating MMP9 to reduce the expression level of intercellular tight junction proteins occludin and ZO-1.
Rats ; Animals ; Matrix Metalloproteinase 9/metabolism* ; NF-E2-Related Factor 2/metabolism* ; Tight Junction Proteins/metabolism* ; Occludin/pharmacology* ; Choroid Plexus/metabolism* ; Reactive Oxygen Species/metabolism* ; Lanthanum/pharmacology* ; Epithelial Cells ; Zonula Occludens-1 Protein/metabolism* ; Phosphoproteins/pharmacology*

Tooth root development involves intricate spatiotemporal cellular dynamics and molecular regulation. The initiation of Hertwig's epithelial root sheath (HERS) induces odontoblast differentiation and the subsequent radicular dentin deposition. Precisely controlled signaling pathways modulate the behaviors of HERS and the fates of dental mesenchymal stem cells (DMSCs). Disruptions in these pathways lead to defects in root development, such as shortened roots and furcation abnormalities. Advances in dental stem cells, biomaterials, and bioprinting show immense promise for bioengineered tooth root regeneration. However, replicating the developmental intricacies of odontogenesis has not been resolved in clinical treatment and remains a major challenge in this field. Ongoing research focusing on the mechanisms of root development, advanced biomaterials, and manufacturing techniques will enable next-generation biological root regeneration that restores the physiological structure and function of the tooth root. This review summarizes recent discoveries in the underlying mechanisms governing root ontogeny and discusses some recent key findings in developing of new biologically based dental therapies.
Female ; Humans ; Tooth Root/metabolism* ; Odontogenesis ; Epithelial Cells ; Cell Differentiation ; Biocompatible Materials/metabolism*

Through bioinformatics predictions, we identified that GTF2I and FAT1 were downregulated in thyroid carcinoma (TC). Further, Pearson's correlation coefficient revealed a positive correlation between GTF2I expression and FAT1 expression. Therefore, we selected them for this present study, where the effects of bone marrow mesenchymal stem cell-derived EVs (BMSDs-EVs) enriched with GTF2I were evaluated on the epithelial-to-mesenchymal transition (EMT) and stemness maintenance in TC. The under-expression of GTF2I and FAT1 was validated in TC cell lines. Ectopically expressed GTF2I and FAT1 were found to augment malignant phenotypes of TC cells, EMT, and stemness maintenance. Mechanistic studies revealed that GTF2I bound to the promoter region of FAT1 and consequently upregulated its expression. MSC-EVs could shuttle GTF2I into TPC-1 cells, where GTF2I inhibited TC malignant phenotypes, EMT, and stemness maintenance by increasing the expression of FAT1 and facilitating the FAT1-mediated CDK4/FOXM1 downregulation. In vivo experiments confirmed that silencing of GTF2I accelerated tumor growth in nude mice. Taken together, our work suggests that GTF2I transferred by MSC-EVs confer antioncogenic effects through the FAT1/CDK4/FOXM1 axis and may be used as a promising biomarker for TC treatment.
Mice ; Animals ; Cell Line, Tumor ; Cell Proliferation ; Mice, Nude ; Epithelial-Mesenchymal Transition ; Thyroid Neoplasms/pathology* ; Extracellular Vesicles/pathology* ; Mesenchymal Stem Cells ; Transcription Factors, TFIII/metabolism* ; Neoplastic Stem Cells/pathology*

Objective: To investigate the cytotoxic effects of induced pluripotent stem (iPS) cells of anti-mesothelin (MSLN)-chimeric antigen receptor natural killer (CAR-NK) cells (anti-MSLN-iCAR-NK cells) on ovarian epithelial cancer cells. Methods: Twenty cases of ovarian cancer patients who underwent surgical treatment at Henan Provincial People's Hospital from September 2020 to September 2021 were collected, and 20 cases of normal ovarian tissues resected during the same period due to other benign diseases were also collected. (1) Immunohistochemistry and immunofluorescence were used to verify the expression of MSLN protein in ovarian cancer tissues. (2) Fresh ovarian cancer tissues were extracted and cultured to obtain primary ovarian cancer cells. Recombinant lentiviral vectors targeting anti-MSLN-CAR-CD₂₄₄ were constructed and co-cultured with iPS cells to obtain anti-MSLN-iCAR cells. These cells were differentiated into anti-MSLN-iCAR-NK cells using cytokine-induced differentiation method. The cell experiments were divided into three groups: anti-MSLN-iCAR-NK cell group, natural killer (NK) cell group, and control group. (3) Flow cytometry and live cell staining experiment were used to detect the apoptosis of ovarian cancer cells in the three groups. (4) Enzyme-linked immunosorbent assay (ELISA) was used to measure the expression levels of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), granzyme B (GZMB), perforin 1 (PRF1), interleukin (IL)-6, and IL-10 in the three groups of ovarian cancer cells. Results: (1) Immunohistochemistry analysis showed that a positive expression rate of MSLN protein in ovarian cancer tissues of 65% (13/20), while normal ovarian tissues had a positive rate of 30% (6/20). The comparison between the two groups was statistically significant (χ²=4.912, P=0.027). Immunofluorescence analysis revealed that the positive expression rate of MSLN protein in ovarian cancer tissues was 70% (14/20), while normal ovarian tissues had a positive rate of 30% (6/20). The comparison between the two groups was statistically significant (χ²=6.400, P=0.011). (2) Flow cytometry analysis showed that the apoptotic rate of ovarian cancer cells in the anti-MSLN-iCAR-NK cell group was (29.27±0.85)%, while in the NK cell group and control group were (8.44±0.34)% and (6.83±0.26)% respectively. There were statistically significant differences in the comparisons between the three groups (all P<0.01). Live cell staining experiment showed that the ratio of dead cells to live cells in the anti-MSLN-iCAR-NK cell group was (36.3±8.3)%, while in the NK cell group and control group were (5.4±1.4)% and (2.0±1.3)% respectively. There were statistically significant differences in the comparisons between the three groups (all P<0.001). (3) ELISA analysis revealed that the expression levels of IFN-γ, TNF-α, GZMB, PRF1, IL-6, and IL-10 in ovarian cancer cells of the anti-MSLN-iCAR-NK cell group were significantly higher than those in the NK cell group and the control group (all P<0.05). Conclusion: The anti-MSLN-iCAR-NK cells exhibit a strong killing ability against ovarian cancer cells, indicating their potential as a novel immunotherapy approach for ovarian cancer.
Humans ; Female ; Carcinoma, Ovarian Epithelial/metabolism* ; Ovarian Neoplasms/metabolism* ; Interleukin-10/pharmacology* ; Induced Pluripotent Stem Cells/metabolism* ; Iron-Dextran Complex/pharmacology* ; Tumor Necrosis Factor-alpha/metabolism* ; Cell Line, Tumor ; Killer Cells, Natural ; Interleukin-6

Humans ; Nerve Tissue Proteins ; Epithelial-Mesenchymal Transition/genetics* ; Constriction, Pathologic ; Receptors, Immunologic ; Epithelial Cells/metabolism* ; Smad3 Protein/metabolism* ; Transforming Growth Factor beta1/metabolism*

Animals ; Humans ; Thymic Stromal Lymphopoietin ; Pyroglyphidae/metabolism* ; Cytokines/metabolism* ; Asthma/metabolism* ; Respiratory System ; Epithelial Cells/metabolism*