Acta Histochemica Et Cytochemica最新文献

Spinal cord injury (SCI) is incurable and often leads to permanent motor dysfunction, paralysis, and sensory impairment. We previously developed a method to directly reprogram human fibroblasts into neuron-like cells using only chemical compounds. In a rat model of SCI, we transplanted chemically reprogrammed cells, termed immature chemical-induced neuron-like (CiN) cells, derived using the developed method with slight modifications and found that the immature CiN cells exhibited therapeutic efficacy in SCI. As primate models more closely mimic humans than rat models, primate experiments are required to more accurately assess the safety and efficacy of immature CiN cells before their use in humans. Therefore, in this study, we aimed to determine the therapeutic efficacy of immature CiN cell transplantation in a marmoset SCI model. Immature CiN cells were transplanted into a subacute marmoset model of SCI on Day 9 after contusion injury, and the therapeutic efficacy was assessed. Motor recovery after SCI was assessed based on spontaneous motor activity and the original open-field rating scale over six weeks, after which the spinal cord at the injury site was subjected to histopathological and MRI analyses. Animals transplanted with immature CiN cells exhibited significantly enhanced motor recovery compared to control animals, consistent with improved nerve recovery or preservation. Our findings suggest that immature CiN cells can effectively treat SCI in primates.

Immune tolerance is essential for safeguarding the body's own tissues from immune system attacks. During pregnancy, the maternal immune system tolerates the semi-allogeneic fetus through mechanisms such as placental programmed cell death 1 (PD-1)-ligand 1 (PD-L1) expression, regulatory T cells (Tregs), cytokine modulation, and hormonal changes. Placental PD-L1 is particularly important in suppressing maternal immune responses and preventing fetal rejection. Following delivery, the loss of the PD-L1-rich placenta can destabilize immune tolerance, potentially leading to postpartum autoimmune diseases such as fulminant type 1 diabetes, characterized by rapid insulin depletion and severe hyperglycemia. Similarly, immune checkpoint inhibitors (ICIs), widely used in cancer immunotherapy, block immune checkpoints like PD-1 and PD-L1 to enhance antitumor immunity by disrupting immunotolerance to tumors. However, this mechanism can sometimes result in immune-related adverse events (irAEs), including fulminant type 1 diabetes. Given the critical role of HLA haplotypes and environmental factors in the development of autoimmune conditions, identifying shared factors among postpartum individuals and patients undergoing ICI therapy who experience immune system abnormalities could provide valuable insights. Such understanding may improve strategies for managing autoimmune diseases associated with both postpartum immune changes and ICI treatments.

SET domain bifurcated 1 (SETDB1), a histone H3K9-specific methyltransferase, is crucial for heterochromatin formation and intestinal homeostasis, but its role in intestinal ischemia-reperfusion injury (IRI) remains unclear. This study investigated changes in SETDB1-mediated nuclear chromatin regulation in intestinal epithelial cells (IECs) using an IRI mouse model. Jejunal samples were collected after 75 min of ischemia followed by 24 hr of reperfusion. Sinefungin was administered as a histone methyltransferase inhibitor. Morphologic changes were evaluated using hematoxylin-eosin staining and electron microscopy, and cell-adhesion molecule expression, including ZO-1, E-cadherin, integrin-β4, and laminin, was evaluated using immunohistochemistry. Super-resolution microscopy analyzed intranuclear SETDB1 localization and heterochromatin formation in IECs. IRI-affected jejunum exhibited massive IEC detachment, dilated intercellular spaces, basement membrane damage, and decreased expression of E-cadherin and integrin-β4. Sinefungin prevented these changes, however. The proportion of IECs expressing nuclear SETDB1 throughout the euchromatin was significantly higher in IRI-affected jejunum (77.8%) than sham-treated (3.0%) or sinefungin-treated, IRI-affected jejunum (2.7%). The proportion of IECs with decreased heterochromatin was significantly higher in sinefungin-treated, IRI-affected jejunum (84.3%) than untreated IRI-affected jejunum (15.6%). These findings suggest that SETDB1-mediated chromatin regulation is pivotal in intestinal IRI and represents a potential therapeutic target.

Inflammatory bowel disease is triggered by abnormalities in epithelial barrier function and immunological responses, although its pathogenesis is poorly understood. The dextran sodium sulphate (DSS)-induced colitis model has been used to examine inflammation in the colon. Damage to mucosa primality occurs in the large intestine and scarcely in the small intestine. To evaluate the effect on the ileum, we histologically analyzed the inflammatory and recovery phases in DSS model mice, and 40 kDa FITC-dextran was used to investigate barrier function. In the inflammatory phase, histological damage was insignificant. However, expanded crypts, hypertrophic goblet and Paneth cells, increased mucus production and secretion were observed. The cellular morphology was restored to that of the control in the recovery phase. According to in situ hybridization and lectin histochemistry, the expression of intestinal stem cell markers, secretory cell differentiation factors, and glycosylation of secretory granules in Paneth cells differed in the DSS model. DSS-treatment did not influence the barrier function in the ileum, and FITC-dextran did not diffuse via the paracellular pathway into the mucosa. However, cells incorporating FITC appeared even under normal conditions. The number of FITC-positive Paneth cells was lower in the DSS group than the control group. Our results showed morphological and functional alterations in ileal epithelial cells, especially secretory cells, in the DSS colitis model.

Cell-to-cell communications are desirable for efficient functioning in endocrine cells. Gap junctions and paracrine factors are major mechanisms by which neighboring endocrine cells communicate with each other. The current experiment was undertaken to morphologically examine gap junction expression and developmental changes in rat adrenal medullary chromaffin (AMC) cells. The expression of connexin 43 (Cx43) was conspicuous in the rat adrenal cortex, but not detected immunohistochemically in neonatal or adult AMC cells. Consistent with the morphological findings, the phosphorylated and non-phosphorylated forms of Cx43 were predominantly and faintly detected by immunoblotting in the adrenal cortical and medullary homogenates, respectively. In contrast to Cx43, Cx36-like immunoreactive (IR) material was detected in neonatal AMC cells, a fraction of which were in the process of migration to the center of the adrenal gland, but this was not seen in adult AMC cells. The current results raise the possibility that the mechanism for cell-to-cell communication changes in a developmental manner in rat AMC cells.

In classical cell culture techniques, cancer cells typically proliferate in a single layer by adhering to the undersurface of laboratory vessels. Consequently, concerns have been raised regarding the fidelity of the morphological and functional characteristics of these cultured cancer cells compared to those of their in vivo counterparts. Our previous studies have investigated various epithelial malignant tumors utilizing the Tissueoid cell culture system, a three-dimensional (3D) cultivation method employing Cellbed-a nonwoven sheet composed of high-purity silica fibers as a scaffold. In this investigation, we have achieved successful 3D culturing of glioblastoma cells (A172 and T98G), which are non-epithelial in nature. As such our focus is to juxtapose their morphological features against that of those cultivated via conventional two-dimensional (2D) methods. Our findings will be elucidated using immunostaining, immunofluorescence staining, and scanning electron microscopy, substantiated with accompanying imaging. Notably, cells cultured in the 3D environment exhibited distinct morphological attributes compared to those of their 2D counterparts, notably featuring pronounced cellular protrusions. We envisage the continued utilization of the 3D culture platform to facilitate diverse avenues of research, encompassing the exploration of novel therapeutic modalities for glioblastoma cells and beyond.

We investigated the localization of both CD31- and endomucin-expressing vessels in mouse dental pulp to elucidate their relationship with dentin formation. The maxillae of C57BL/6 male mice (1, 4, 8, 12, and 56 weeks old) were fixed with 4% paraformaldehyde solution, and cryosections (12-μm-thick) were prepared. Immunofluorescence was performed using anti-CD31 and anti-endomucin antibodies, and calcein labeling was conducted to elucidate relationships with dentin formation. At 1 week, many CD31-expressing (CD31 (+)) and endomucin-expressing (endomucin (+)) vessels were observed throughout the dental papilla. At 4 weeks, CD31 (+) and endomucin (+) vessels decreased in the crown and increased in the root of dental pulp. At 12 weeks, CD31 (+) and endomucin (+) vessels were detected at the root apex, but not in coronal pulp. At 56 weeks, few CD31 (+) and endomucin (+) vessels were observed in dental pulp. Both CD31(+) and endomucin (+) vessels were detected directly beneath calcein-labeled dentin at all sites. These results suggest the presence of CD31 (+) and endomucin (+) vessels in dental pulp and their contribution to dentin formation.

Gastric cancer (GC) is the third leading cause of cancer-related deaths in Japan, underscoring the urgent need for deeper insights into its pathogenesis. Spheroids provide a more realistic and versatile model for studying cancers and cancer stem cells (CSCs). While fructose-bisphosphate aldolase C (ALDOC) has been identified in colorectal cancer spheroids, its role in GC has remained largely unexplored. This study aimed to elucidate the role of ALDOC in GC by performing single-cell and functional analyses of GC spheroids and cell lines, along with immunohistochemistry of 127 GC samples to assess its correlation with CSC markers. Our single-cell analysis revealed upregulation of ALDOC in spheroids, with pseudotime analysis indicating that ALDOC-expressing cells were predominantly undifferentiated and co-expressed LGR5 and CD44. Further investigation into cell-cell interactions suggested that the stem cell state may be maintained by WNT, BMP, and EGF signaling. Functional assays demonstrated that ALDOC knockdown led to a marked reduction in the growth, invasiveness, and spheroid colony formation capacity of GC cell lines. Clinically, ALDOC was detected in the cytoplasm of 56.7% (72/127) of GC cases, and high ALDOC expression was significantly associated with poor overall survival (p < 0.01), and was an independent prognostic factor. Moreover, a significant association between ALDOC and CD44 expression in GC (p = 0.031). Conclusively, our findings identify ALDOC as a crucial prognostic marker and provide new insights into GC pathogenesis.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is becoming a major health problem worldwide. Liver regeneration is crucial for restoring liver function, and is regulated by extraordinary complex process, involving numerous factors under both physiologic and pathologic conditions. Sphingosine-1-phosphate (S1P), a bioactive sphingolipid synthesized by sphingosine kinase 1 (SphK1), plays an important role in liver function through S1P receptors (S1PRs)-expressing cells. In this study, we investigated the effect of lipid overload on hepatocyte proliferation in a mouse hepatic steatosis model induced by feeding a methionine- and choline-deficient (MCD) diet. After 50% partial hepatectomy (PHx), liver tissues were sampled at various timepoints and then analyzed by immunohistochemistry, oil Red-O staining, quantitative-polymerase chain reaction (qPCR), and flow cytometry. In mice fed the MCD-diet, significantly exacerbated hepatic steatosis and accelerated liver regeneration were observed. After PHx, hepatocyte proliferation peaked at 48 and 36 hr in the liver of chow- and MCD-diet fed mice, respectively. By contrast, increased expression of S1PR2 was observed in hepatic neutrophils and macrophages of MCD-diet fed mice. Flow cytometry and qPCR experiments demonstrated that levels of HGF and FGF2 released by neutrophils and macrophages were significantly higher in MCD-diet fed mice. In conclusion, hepatic lipid overload recruits Kupffer cells and neutrophils that release HGF and FGF2 via SphK1/S1PR2 activation to accelerate hepatocyte proliferation.

Multiple sclerosis, neuromyelitis optica, Guillain-Barré syndrome and chronic inflammatory demyelinating polyradiculoneuropathy are representative demyelinating diseases of the central and peripheral nervous system. Remyelination by myelin forming cells is important for functional recovery from the neurological deficits caused in the demyelinating diseases. Lysophosphatidylcholine-induced demyelination in mice is commonly used to identify and study the molecular pathways of demyelination and remyelination. However, detection of focally demyelinated lesions is difficult and usually requires sectioning of demyelinated lesions in tissues for microscopic analysis. In this review, we describe the development and application of a novel vital staining method for labeling demyelinated lesions using intraperitoneal injection of neutral red (NR) dye. NR labeling reduces the time and effort required to search for demyelinated lesions in tissues, and facilitates electron microscopic analysis of myelin structures. NR labeling also has the potential to contribute to the elucidation of pathologies in the central and peripheral nervous system and assist with identification of drug candidates that promote remyelination.