Cell and Tissue Research最新文献

Hematopoietic stem cells (HSCs) drive cellular turnover in the hematopoietic system by balancing self-renewal and differentiation. In the adult bone marrow (BM), these cells are regulated by a complex cellular microenvironment known as "niche," which involves dynamic interactions between diverse cellular and non-cellular elements. During blood cell maturation, lineage branching is guided by clusters of genes that interact or counteract each other, forming complex networks of lineage-specific transcription factors. Disruptions in these networks can lead to obstacles in differentiation, lineage reprogramming, and ultimately malignant transformation, including acute myeloid leukemia (AML). Zinc Finger Protein 521 (Znf521/Zfp521), a conserved transcription factor enriched in HSCs in both human and murine hematopoiesis, plays a pivotal role in regulating HSC self-renewal and differentiation. Its enforced expression preserves progenitor cell activity, while inhibition promotes differentiation toward the lymphoid and myeloid lineages. Transcriptomic analysis of human AML patient samples has revealed upregulation of ZNF521 in AMLs with the t(9;11) fusion gene MLL-AF9. In vitro studies have shown that ZNF521 collaborates with MLL-AF9 to enhance the growth of transformed leukemic cells, increase colony formation, and activate MLL target genes. Conversely, inhibition of ZNF521 using short-hairpin RNA (shRNA) results in decreased leukemia proliferation, reduced colony formation, and induction of cell cycle arrest in MLL-rearranged AML cell lines. In vivo experiments have demonstrated that mZFP521-deficient mice transduced with MLL-AF9 experience a delay in leukemia development. This review provides an overview of the regulatory network involving ZNF521, which plays a crucial role in controlling both HSC self-renewal and differentiation pathways. Furthermore, we examine the impact of ZNF521 on the leukemic phenotype and consider it a potential marker for MLL-AF9⁺ AML.

Smell and taste are extensively studied in fish species as essential for finding food and selecting mates while avoiding toxic substances and predators. Depending on the evolutionary position and adaptation, a discrete variation in the morphology of these sense organs has been reported in numerous teleost species. Here, for the first time, we approach the phenotypic characterization of the olfactory epithelium and taste buds in the African turquoise killifish (Nothobranchius furzeri), a model organism known for its short lifespan and use in ageing research. Our observations indicate that the olfactory epithelium of N. furzeri is organized as a simple patch, lacking the complex folding into a rosette, with an average size of approximately 600 µm in length, 300 µm in width, and 70 µm in thickness. Three main cytotypes, including olfactory receptor neurons (CalbindinD28K), supporting cells (β-tubulin IV), and basal cells (Ki67), were identified across the epithelium. Further, we determined the taste buds' distribution and quantification between anterior (skin, lips, oral cavity) and posterior (gills, pharynx, oesophagus) systems. We identified the key cytotypes by using immunohistochemical markers, i.e. CalbindinD28K, doublecortin, and neuropeptide Y (NPY) for gustatory receptor cells, glial fibrillary acidic protein (GFAP) for supporting cells, and Ki67, a marker of cellular proliferation for basal cells. Altogether, these results indicate that N. furzeri is a microsmatic species with unique taste and olfactory features and possesses a well-developed posterior taste system compared to the anterior. This study provides fundamental insights into the chemosensory biology of N. furzeri, facilitating future investigations into nutrient-sensing mechanisms and their roles in development, survival, and ageing.

The umbilical cord epithelium (UCE) is the surface tissue that covers the umbilical cord (UC). It is widely considered a single-layered epithelium composed of squamous or cuboidal cells, which are in constant contact with amniotic fluid. The objective of this study was to elucidate the distinctive structural characteristics and abundance of specific proteins in this unique epithelium, many of which have not been previously demonstrated. Samples of the UC were obtained from term pregnancies (n = 12) and processed for examination using stereo, light, electron, and 3D high-resolution confocal microscopy. Sections displayed a range of stratification, ranging from a single squamous layer to 4-5 layers of round/cuboid cells, challenging the notion of considering it as a single-layered structure. Cells are located on a well-developed basement membrane (BM), as evidenced by the expression of BM-specific proteins and PAS staining. The cells possess distinctive cytoplasmic domains that are tightly bound to each other by desmosomes and interdigitating anchoring surfaces. Desquamations and limited organelles suggest that the cells have reached the final stages of differentiation and are no longer actively synthesizing proteins, despite maintaining stratification-specific expression levels of cytoskeletal, junctional, receptor, and stem cell proteins. Although definitive keratinization was not observed, the distribution of proteins and the distinctive structural organization of the single/multi-layered cells suggest that they exhibit plasticity, likely due to adaptive mechanisms in response to chemical and/or mechanical stimuli during fetal development. These structural alterations may facilitate the active transportation of soluble ingredients between the amniotic fluid and cord blood through an intercellular route.

During postnatal development of the rat epididymis, a change in the expression of gap junction proteins, or connexins (Cxs), occurs, in which Gjb2 (Cx26) and Gja1 (Cx43) levels in the proximal epididymis are decreased, while Gjb1 (Cx32), Gjb4 (Cx30.3) and Gjb5 (Cx31.1) levels increase. The mechanism(s) responsible for the switch in Cx expression is unknown. The aim of this study is to identify the mechanisms responsible for the decrease in GJB2 protein levels and the increase in other Cxs during postnatal development. Results indicate that decreased Gjb2 expression for 48 h does not alter the expression of other Cxs in RCE-1 principal cells, suggesting a lack of compensatory expression. Sequence analysis of both Gjb2 and Gjb1 promoters identified common multiple response elements to steroid hormones. Using RCE-1 cells, we observed that dexamethasone increased Gjb2 mRNA levels by twofold after 48 h, while estradiol had no effect. Orchidectomy in rats resulted in a significant increase in GJB2 and decreased GJB1 in the caput and corpus epididymidis. Changes in Cxs protein levels were prevented by testosterone in orchidectomized rats. Similar results were observed in the prostate, another androgen-receptive organ. LNCaP cells, which are androgen-responsive, showed that exogenous dihydrotestosterone (DHT) decreased Gjb2 mRNA levels by approximately 50% concomitant with a 1.5-fold increase in Gjb1 levels. Using a GJB1 promoter construct we showed that DHT could induce transactivation of the luciferase transgene, while transactivation of two GJB2 promoters were unaltered. Results indicate that androgens and glucocorticoids regulate the expression of epididymal Cxs.

In this study, we aimed to promote the maturation of cardiomyocytes-like cells by mechanical stimulation, and evaluate their therapeutic potential against myocardial infarction. The cyclic tensile strain was used to induce the maturation of cardsiomyocyte-like cells from P19 cells in vitro. Western blot and qPCR assays were performed to examine protein and gene expression, respectively. High-resolution respirometry was used to assay cell function. The induced cells were then evaluated for their therapeutic effect. In vitro, we observed cyclic tensile strain induced P19 cell differentiation into cardiomyocyte-like cells, as indicated by the increased expression of cardiomyocyte maturation-related genes such as Myh6, Myl2, and Gja1. Furthermore, cyclic tensile strain increased the antioxidant capacity of cardiomyocytes by upregulating the expression Sirt1, a gene important for P19 maturation into cardiomyocyte-like cells. High-resolution respirometry analysis of P19 cells following cyclic tensile strain showed enhanced metabolic function. In vivo, stimulated P19 cells enhanced cardiac function in a mouse model of myocardial infarction, and these mice showed decreased infarction-related biomarkers. The current study demonstrates a simple yet effective mean to induce the maturation of P19 cells into cardiomyocyte-like cells, with a promising therapeutic potential for the treatment of myocardial infarction.

The Kupffer cell was first discovered by Karl Wilhelm von Kupffer in 1876, labeling them as "Sternzellen." Since their discovery as the primary macrophages of the liver, researchers have gradually gained an in-depth understanding of the identity, functions, and influential role of Kupffer cells, particularly in infection. It is becoming clear that Kupffer cells perform important tissue-specific functions in homeostasis and disease. Stationary in the sinusoids of the liver, Kupffer cells have a high phagocytic capacity and are adept in clearing the bloodstream of foreign material, toxins, and pathogens. Thus, they are indispensable to host defense and prevent the dissemination of bacteria during infections. To highlight the importance of this cell, this review will explore the history of the Kupffer cell in the context of infection beginning with its discovery to the present day.

Sustained or chronic inflammation in the placenta can result in placental insufficiency, leading to adverse reproductive outcomes such as pregnancy loss. Branched-chain amino acid transaminase 1 (BCAT1) expresses in the placenta and is involved in the pathological inflammatory response, but its role in recurrent miscarriage (RM) has not been fully investigated. In the present study, we delved into the effects of BCAT1 on trophoblast inflammation induced by lipopolysaccharide (LPS) and a mouse model of pregnancy loss induced by LPS. In vitro, after the HTR-8/SVneo cells were treated with LPS and BCATc inhibitor 2 (a selective BCAT inhibitor), the cell apoptosis was verified by TUNEL assay, and the activity of caspase-3 and caspase-9 was detected. Real-time PCR, enzyme-linked immunosorbent assay (ELISA), and immunofluorescence (IF) were used to determine the expression of inflammatory cytokines (TNF-α, IL-6, and IL-1β) and inflammasomes (NLRP3 and ASC) in LPS-treated trophoblast cells. Western blot analysis was performed to verify the expression of phospho-IκBα (p-IκBα) in cells and NF-κB p65 in the nuclei. IF staining was used to detect the nuclear translocation of NF-κB p65. The DNA binding activity of NF-κB was detected by an electrophoretic mobility shift assay (EMSA). The results demonstrated that inhibition of BCAT1 reduced trophoblast apoptosis, suppressed the release of proinflammatory cytokines, and prevented NLRP3 inflammasome activation in response to LPS. Additionally, BCAT1 inhibition blocked the activation of the NF-κB pathway in trophoblasts. This study highlights the potential therapeutic role of targeting BCAT1 in preventing adverse reproductive outcomes associated with chronic placental inflammation.

Infections are common in patients with diabetes. Moreover, increasing incidence of antibiotic resistance impedes the complete bacterial clearance and calls for alternative treatment strategies. Along with antibacterial resistance, compromised host conditions create a favorable condition for the disease progression. In particular, cell junction proteins are of major importance as they contribute to a tight cell barrier, protecting against invading pathogens. However, the impact of high glucose on cell junction proteins has received little attention in the urinary bladder but merits closer investigation. Here, we report that during diabetes the expression of cell junction protein, claudin 14 is compromised in the human urine exfoliated cells and in the urinary bladder of type 2 diabetic mouse. Further in vitro analysis confirmed a direct correlation of lower intracellular calcium levels with claudin 14 expression in high glucose-treated human uroepithelial cells. Moreover, external calcium supplementation in high glucose-treated cells significantly affected the cell migration and restored the claudin 14 expression through focal adhesion and β-1 integrins. Strengthening the epithelial barrier is essential, especially in individuals with diabetes where basal calcium levels could contribute.

In goldfish, spinal cord injury triggers the formation of a fibrous scar at the injury site. Regenerating axons are able to penetrate the scar tissue, resulting in the recovery of motor function. Previous findings suggested that regenerating axons enter the scar through tubular structures surrounded by glial elements with laminin-positive basement membranes and that glial processes expressing glial fibrillary acidic protein (GFAP) are associated with axonal regeneration. How glia contribute to promoting axonal regeneration, however, is unknown. Here, we revealed that glial processes expressing vimentin or brain lipid-binding protein (BLBP) also enter the fibrous scar after spinal cord injury in goldfish. Vimentin-positive glial processes were more numerous than GFAP- or BLBP-positive glial processes in the scar tissue. Regenerating axons in the scar tissue were more closely associated with vimentin-positive glial processes than GFAP-positive glial processes. Vimentin-positive glial processes co-expressed matrix metalloproteinase (MMP)-14. Our findings suggest that vimentin-positive glial processes closely associate with regenerating axons through tubular structures entering the scar after spinal cord injury in goldfish. In intact spinal cord, ependymo-radial glial cell bodies express BLBP and their radial processes express vimentin, suggesting that vimentin-positive glial processes derive from migrating ependymo-radial glial cells. MMP-14 expressed in vimentin-positive glial cells and their processes might provide a beneficial environment for axonal regeneration.

Germline stem cells are a crucial type of stem cell that can stably pass on genetic information to the next generation, providing the necessary foundation for the reproduction and survival of organisms. Male mammalian germline stem cells are unique cell types that include primordial germ cells and spermatogonial stem cells. They can differentiate into germ cells, such as sperm and eggs, thereby facilitating offspring reproduction. In addition, they continuously generate stem cells through self-renewal mechanisms to support the normal function of the reproductive system. Autophagy involves the use of lysosomes to degrade proteins and organelles that are regulated by relevant genes. This process plays an important role in maintaining the homeostasis of germline stem cells and the synthesis, degradation, and recycling of germline stem cell products. Recently, the developmental regulatory mechanism of germline stem cells has been further elucidated, and autophagy has been shown to be involved in the regulation of self-renewal and differentiation of germline stem cells. In this review, we introduce autophagy accompanying the development of germline stem cells, focusing on the autophagy process accompanying the development of male spermatogonial stem cells and the roles of related genes and proteins. We also briefly outline the effects of autophagy dysfunction on germline stem cells and reproduction.