Cell and Tissue Research最新文献

Septoclasts (SCs), which express both fatty acid-binding protein 5 and platelet-derived growth factor beta, are mononuclear cartilage-resorbing cells predominantly located at the chondro-osseous junction of the growth plate (GP). These cells originate from pericytes (PCs). Cathepsin B (CTSB) and matrix metalloproteinase-13 (MMP13), expressed in SCs, participate in the degradation of collagen and other cartilage matrices. This study aimed to investigate the involvement of the ETS proto-oncogene 1 (ETS1) in the transcription of Ctsb and Mmp13 during the differentiation of SCs from PCs. ETS1 was localized in SCs and a small number of PCs during development and postnatal stages. Upregulation of Ets1, Mmp13, Ctsb, and the Ets1-related genes, specificity protein 1 (Sp-1), jun proto-oncogene (c-Jun), and cAMP response element-binding protein-binding protein (Crebbp) in SCs compared with those in PCs was shown by RNA-seq analysis of samples isolated from the tibiae of 3-week-old postnatal mice. The Ets1-related proteins were localized ubiquitously in SCs and PCs in the GP. In primary SC cultures, the expression levels of Ctsb and Mmp13 were significantly reduced following treatment with Ets1 siRNA. Thus, our results revealed that ETS1 promoted the expression of Ctsb and Mmp13 in SCs during the differentiation of SCs from PCs.

Pulmonary surfactant is essential for lung function and consists mainly of lipids, almost half of which in adult mammals originate from de novo synthesis in alveolar epithelial type-2 (AE2) cells. Obesogenic nutrition and hypoxia coexist in obese patients with chronic lung diseases. This study tested the hypothesis that diet-induced obesity and chronic hypoxia alter lipid metabolism and thereby deteriorate surfactant homeostasis. Male C57BL/6N mice were fed control diet (4% fat, 6% sucrose; CD), high-sucrose diet (4% fat, 46% sucrose; HSD) or high-fat diet (35% fat, 7% sucrose; HFD). After 27 weeks, half of each diet group was exposed to hypoxia (13% O₂, Hyp) for 3 weeks. After 30 weeks, lung mechanics were assessed, and the blood, livers, and lungs were analyzed. In CD-fed mice, hypoxia induced lung mechanical changes indicative of reduced elastic recoil properties, as well as smaller lamellar bodies (LBs) and higher composite body volumes, suggesting an increased surfactant precursor formation. HSD and HFD induced lipid accumulation in liver and AE2 cells. In HSD-Hyp and HFD-Hyp, LB volumes per alveolar surface area were elevated, indicating compensatory increases in intracellular surfactant pools which were absent in CD-Hyp. Additionally, hypoxia-related lung mechanics alterations were less pronounced in HSD-Hyp and HFD-Hyp. Lung proteome analysis revealed that only a few lipid metabolism-associated proteins were similarly regulated within diet groups under hypoxia, with the most prominent changes in sucrose-fed hypoxic animals. Thus, individual diet-related metabolic states specifically affect the adaptation of the pulmonary lipid metabolism and intracellular surfactant assembly to chronic hypoxia.

Olfaction plays a crucial role in distinguishing odors, enabling organisms to seek benefits and evade hazards. Olfactory receptors (ORs), characterized by highly variable binding pockets, facilitate the detection of diverse odorants from both external and internal environments. Nasal ORs, expressed in olfactory sensory neurons (OSNs), are critical for olfactory cognition and associated neuronal plasticity. In contrast, extra-nasal ORs, expressed in extra-olfactory tissues, detect specific chemicals and modulate cellular processes such as proliferation, migration, inflammation, and apoptosis. Aberrant OR expression or dysfunction has been implicated in numerous human diseases, including anosmia, dementia, dermatopathies, obesity, infertility, cancers, respiratory disorders, atherosclerosis and viral infections. Olfactory training, such as aromatherapy, demonstrates significant therapeutic potential for anosmia, dementia and psychological distress. Natural or synthetic odorants have been applied for promoting hair regeneration and cutaneous wound healing. Conversely, overexpression of specific ORs in cancer cells may drive tumor progression. Additionally, ORs may mediate virus-host interactions during infection, owing to their structural variability. Collectively, OR-targeted agonists and antagonists (odorants) represent promising candidates for treating OR-associated pathologies.

Infertility and subfertility are significant reproductive challenges in cattle, often linked to genetic factors. Among these genetic factors, the bovine Y-linked gene family, PRAMEY, has emerged as a candidate due to its involvement in germ cell formation, fertilization, and embryonic development. This study investigates PRAMEY's role in sperm-egg binding, acrosome integrity, and epigenetic modifications during fertilization and early embryogenesis. Using IVF with bovine spermatozoa treated with either PRAMEY antibody (ab) or rabbit IgG control, we assessed sperm-egg binding and acrosome integrity at 2, 4, and 6 h post-fertilization (hpf). PRAMEY ab treatment doubled sperm binding per oocyte across all time points, with a significant increase at 6 hpf (P ≤ 0.05), although no differences in acrosome integrity were observed (P > 0.05). To explore PRAMEY's role in epigenetic regulation, we analyzed DNA (5-methylcytosine (5-mC)) and histone (H3K9me3 and H3K27me3) methylation in zygotes and embryos using immunofluorescent staining techniques. Zygotes derived from PRAMEY ab-treated spermatozoa showed significantly reduced DNA methylation in paternal pronuclei at 10 hpf and maternal pronuclei at 25 hpf (P ≤ 0.01). Histone methylation analysis revealed no significant differences in H3K9me3 methylation between groups, but H3K27me3 methylation was significantly lower in embryos produced using PRAMEY ab-treated spermatozoa at the 8-cell and morula stages (P ≤ 0.05). In summary, PRAMEY inhibition enhances sperm-egg binding and influences DNA and histone methylation dynamics in bovine embryos, underscoring its potential role in fertilization and early embryonic epigenetic regulation.

The Na,K-ATPase is a vital transmembrane enzyme, which is important for maintaining cell membrane potentials and the general functionality of animal cells. The enzyme's minimal functional unit consists of one α and one β-subunit, whereas the number of existing paralogs varies in different insect species. The functional roles of different β-subunits, which can account for their diversity within a single species, are so far only partially explained. The emphasis of this study was to specifically elucidate the involvement in septate junctions of the four β-subunits of the new model system Oncopeltus fasciatus. Septate junctions function as a paracellular barrier controlling the flow of solutes across epithelia. So far, studies in Drosophila revealed that nervana2, the β2 homolog of Drosophila, is involved in septate junction formation. In O. fasciatus, we demonstrate that most of the Na,K-ATPase subunits colocalize with septate junction proteins. This agrees with our previous findings implying a role of β2 in the control of tracheal tube size in O. fasciatus, which according to the findings in Drosophila appears to be dependent on a stable formation of septate junctions. Finally, our data suggest a connection between the septate junction protein coracle and the enigmatic, N-terminally strongly truncated βx, which has no obvious homologs in other insects. Our study proposes that the four β-subunits form functional units with septate junction proteins, either allowing tissue-adjusted formation of cell-cell contacts or other yet unknown functions.

While the prolonged consumption of sucrose-containing beverages is known to impact many organs, their specific effects on the small intestine remain elusive. This study aimed to evaluate how regular intake of sucrose, in amounts typically consumed, affects goblet cells, which play a critical role in regulating the mucosal barrier and innate immune defenses in the small intestine. Ten-week-old male ddY mice, a model of diet-induced obesity, were given a regular diet with either plain water or 7% sucrose water. Caloric intake was monitored weekly through food and drink measurements. After 8 weeks, glucose and insulin responses were evaluated following an oral gavage of glucose or sucrose. At 14 weeks, plasma, whole small intestine, and liver samples were collected. Despite achieving an isocaloric state, mice drinking sucrose water showed approximately a 1.5-fold increase in body weight and impaired glucose tolerance. In the small intestine, genes involved in sucrose digestion and absorption (Sis, Sglt1, Glut2, and Glut5) were upregulated, while genes essential for maintaining the intestinal barrier and function (Epcam, Fabp2, Cldn1, Ocln, and Tjp1) were downregulated. Serum levels and mRNA expression of the inflammatory cytokine, interleukin-18 were elevated. Genes responsible for goblet cell differentiation and function (Hes1, Gfi1, Spdef, and Klf4) were downregulated, leading to an increase in immature goblet cells and a decrease in mucin-producing markers (Muc2, Muc4, and Muc13) in the jejunum. The findings underscore that besides obesity, long-term intake of sucrose-containing drinks provokes localized inflammation and disrupts small intestinal barrier function by impairing goblet cell differentiation and activity.

During type 1 diabetes (T1D), oxidative stress in beta cells may cause early beta cell dysfunction and initiate autoimmunity. Mouse islets express lower levels of reactive oxygen species (ROS) clearing enzymes, such as glutathione peroxidase (GPX), superoxide dismutase (SOD) and catalase than several other tissues. It remains unclear if human beta cells show a similar deficiency during T1D or exhibit a higher degree of intrinsic resistance to oxidative stress. We compared islet cell distributions and determined graded intensities of glutathione peroxidase1 (GPX1), a key enzymatic mediator involved in detoxifying hydrogen peroxide, by applying combined immunohistochemistry for GPX1, insulin and glucagon, in pancreatic sections from new-onset T1D (group 1), non-diabetic autoantibody-negative (group 2), non-diabetic autoantibody-positive (group 3) and long-term diabetic (group 4) donors. Islets from all study groups demonstrated either uniform but graded staining intensities for GPX1 in almost all islet cells or strong staining in selective islet cells with weaker intensities in the remaining cells. GPX1 was present in selective glucagon cells and insulin cells, including in cells negative for both hormones, with stronger intensities in a higher percentage of glucagon than insulin cells. It was absent in a higher percentage of beta cells than glucagon cells independent of disease or autoantibody positivity. We conclude that a proportion of human beta cells and glucagon cells express GPX1 but show heterogeneity in its distribution and intensities, independent of disease or autoantibody status. Our studies highlight important differences in the expression of GPX1 in islet cell-types between mice and humans.

Alzheimer's disease (AD) is an age-related neurodegenerative disorder characterised by several factors, such as impaired glutamate neurotransmission affecting crucial functions. Neural stem cells (NSCs) are present in the adult brains of all mammalian species and contribute to the continuous generation of neural cells throughout life. The disruption of glutamate levels during the development of AD could impact NSCs' functionality, influencing their response to the microenvironment. In this work, we isolated adult neural stem cells from both triple transgenic (3xTg)-AD mice and age-matched wild type (WT) mice in order to gather information on any differences between them, particularly concerning the potential mechanisms involved in the internalisation of glutamate and its utilisation for energy production. The 3xTg model offers the ability to recapitulate human pathology with both plaque and tangle hallmarks that are involved in the process of glutamate release. In vitro culture 3xTg NSCs showed a slight morphological difference compared to WT cells and a massive reduction of proliferation and viability. Furthermore, 3xTg NSCs displayed an increase in the expression of glutamate transporters and glutamine synthetase, while glutamate dehydrogenase did not show any reduction, which is typical in AD brains. Data obtained from this basic research study suggest a possible involvement of glutamate in the cellular energy balance, indicating an attempted response of NSCs to the cytotoxic microenvironment in the early stage of AD pathology. This finding is of great interest, as it corroborates the hypothesis that targeting the glutamatergic system could be an extremely promising strategy for new therapeutics in AD.

Microtubules are the principal cytoskeletal component in cells, integral to various morphogenetic processes in Metazoa, including cell migration, adhesion, and polarity. Their dynamics and functions are modulated by tubulin post-translational modifications (PTMs). While studies on model species have provided insights into microtubule functions, understanding their evolutionary aspects necessitates exploring non-model organisms. Sponges (phylum Porifera) are an early-branching metazoan group with outstanding regenerative capacities. This research presents the first comprehensive analysis of microtubule organization and tubulin PTMs in calcareous sponges. The intact sponge cells show various but typical types of microtubule organization, while detected tubulin PTMs are associated with certain cell types, indicating specific functions in particular cellular contexts. During regeneration, relying on the coordinated movement of epithelial-like cell sheets, microtubule networks in exopinacocytes and choanocytes undergo significant reorganization. These rearranged microtubules potentially stabilize cellular migration direction and facilitate cargo transport, essential for cell contact and polarity establishment. This study enhances our understanding of microtubule functionality and regulation in early-diverging metazoans, contributing to the broader evolutionary context of cytoskeletal dynamics.

Hydroxyapatite nanoparticle (HANPs) utilization has recently been notable in bone tissue engineering. This surge owes itself to the biocompatibility of HANPs and their striking resemblance to the minerals found in natural bone. Furthermore, dental pulp-derived stem cells (DPSCs) have garnered attention due to their remarkable differentiation potential into multilineages, thus positioning them as a pivotal cell reservoir for regenerative medicine. This study aims to investigate the impact of HANPs on DPSCs cellular processes. The HANPs have been synthesized using the wet chemical precipitation method followed by freeze-drying and characterization using dynamic light scattering (DLS) and transmission electron microscopy (TEM). The size of HANPs was reported to be in the range of 55-67 nm. Our dataset divulges that DPSCs can endure concentrations of HANPs up to ≤ 0.81 mg/mL without incurring any conspicuous alterations in their morphology or the pace of proliferation. Furthermore, the self-renewal potency of HANPs was upheld at concentrations ≤ 0.20 mg/mL. Flow cytometric analysis affirms a significant divergence in cell distribution across all cell cycle phases in DPSCs treated with 0.81 mg/mL HANPs. Intriguingly, no variance surfaced in the migratory capacity of DPSCs exposed to HANPs of ≤ 0.40 mg/mL. For osteogenic differentiation, HANPs at concentrations of ≤ 0.40 mg/mL demonstrated the aptitude to incite osteogenic differentiation within DPSCs, facilitating the formation of calcium deposits. In conclusion, combining HANPs and DPSCs shows promise for restoring damaged hard tissues, like bone and teeth, and enhancing regenerative therapies.