Histochemistry and Cell Biology最新文献

In the human placenta, trophoblast cells give rise to two unique cell layers that envelop the surface of chorionic villi: the outer syncytiotrophoblast (STB) layer and the inner cytotrophoblast (CTB) cell layer. The structural changes in CTB cells during gestation are still not fully understood. This study examined the ultrastructural integrity of the CTB layer within chorionic villi of the human term placenta using Fast Red immunohistochemistry in conjunction with proteinase K/Triton X-100 tissue-clearing and serial block-face scanning electron microscopy (SBF-SEM). Visualization of the CTB layer in whole-mount peripheral villous trees was facilitated by Fast Red immunohistochemistry of SPINT1, a marker specific to CTB cells, under both bright-field and fluorescence imaging modes in light microscopy. CTB cells displayed a thin, flattened morphology and extended multiple cellular projections, resulting in a spider-like transformation that envelops grape-like terminal villi. In contrast, in more proximal villi (e.g., stem villi), CTB cells showed a thick, cuboidal, or polygonal appearance, covering the villous subsurface. SBF-SEM imaging demonstrated the structure of a thin, mesh-like CTB layer, where the basal domain of the villous surface STB infiltrated through the small gaps of the CTB layer and contacted fetal capillaries via the basal lamina in terminal villi. Our data suggest that terminal villi undergo structural changes to facilitate fetomaternal exchange.

The expression of different sarco/endoplasmic reticulum calcium ATPase (SERCA) isoforms is controversial in various cancers and is not clear in the experimental cancer model. The present study attempts to evaluate the expression dynamics of SERCA isoforms in the azoxymethane/dextran sulphate sodium salt (AOM/DSS) model of colorectal carcinogenesis in mice. Inflammation-associated colorectal cancer was induced in the mice by administration of a single dose of AOM and three alternative cycles of DSS in drinking water. Body weights were recorded weekly. Mice were killed at weeks 0, 8, 12 and 16. At those times, the number of tumours was recorded, and colon tissues were processed for histopathological, immunohistochemical and gene expression analysis. The number of tumours and the formation of aberrant crypt foci were found to be significantly higher in the AOM/DSS group compared to the control. Histopathology of the colon revealed a higher percentage of dysplasia, adenoma and adenocarcinoma formation in the AOM/DSS group, further supported by high intensity of immunohistochemical staining for PCNA in the same. Gene expression analysis indicated higher expression of cyclin D1, β-catenin and low expression of E-cadherin, suggesting carcinogenic transformation of the colon. Immunohistochemical and gene expression analysis of SERCA isoforms indicated higher expression of SERCA1 and SERCA2 and low expression of SERCA3 in colon tissues of the AOM/DSS-exposed animals. The present study confirmed a similar expression pattern of SERCA isoforms in the AOM/DSS model of carcinogenesis as reported in clinical samples. Further, this study highlights the fact that altered SERCA patterns could be a contributing factor in the development of colorectal carcinogenesis.

Telocytes (TCs) are interstitial cells characterized by long, thin cytoplasmic extensions called telopodes. Although their presence has been established in various organs, data on their existence and organization within the human ovary remain limited. This study aimed to identify and describe telocytes in the ovarian stroma using immunohistochemical, immunofluorescence, and ultrastructural methods. Ovarian tissues from women aged 24-65 years who underwent total hysterectomy and bilateral salpingo-oophorectomy for nonmalignant uterine diseases were analyzed. TCs were identified by CD34 co-expression with c-KIT, vimentin, platelet-derived growth factor receptor (PDGFR)-β, and alpha-smooth muscle actin (α-SMA) and confirmed by transmission electron microscopy with immunogold labeling. The results demonstrated that telocytes form two to three discontinuous layers around the adventitia of large and medium-sized blood vessels and establish close contacts with stromal components, including smooth muscle cells. This spatial organization suggests their involvement in intercellular communication and stromal coordination within the ovarian microenvironment. These findings provide the first ultrastructural and immunohistochemical evidence of telocytes in the human ovarian stroma and highlight the need for further studies to clarify their physiological and pathological roles in ovarian function, including potential morphological and molecular differences among females of different age groups.

Neoadjuvant chemoradiotherapy (nCRT) followed by surgery is the standard treatment for locally advanced rectal cancer. However, the response to nCRT is variable and not always associated with improved survival. Colorectal cancer (CRC) is characterized by a complex tumor microenvironment (TME), a key component of which is cancer-associated fibroblasts (CAF). While their functions and interactions with tumor cells are under active investigation, the role of distinct CAF subpopulations and their plasticity remains largely undefined. A comprehensive characterization of CAFs during cancer progression could therefore contribute to the development of novel anticancer diagnostic and therapeutic strategies. In this study, we used immunohistochemistry to demonstrate that nCRT induces a significant reorganization of the TME in rectal adenocarcinoma. This reorganization was characterized by a redistribution of myofibroblasts (alpha-smooth muscle actin, αSMA⁺) and tumor-associated fibroblasts (fibroblast activation protein, FAP⁺; and fibroblast-specific protein 1, FSP1⁺), leading to pronounced fibrosis in both central and peripheral tumor regions. A decrease in E-cadherin expression, coupled with increased vimentin and transforming growth factor beta (TGFβ) levels in a subset of patients, indicated activation of epithelial-mesenchymal transition and the emergence of vasculogenic mimicry as an alternative mechanism of tumor vascularization. Ultrastructural analysis revealed structural changes in the cytoplasm of fibroblasts suggestive of active membrane remodeling and fibroblast-myofibroblast transition, particularly at the tumor periphery. Collectively, these findings suggest that nCRT may be accompanied by a reorganization of the tumor stroma, leading to fibroblast activation, epithelial-mesenchymal transition, and vasculogenic mimicry, all of which could potentially contribute to tumor progression.

Oxidative stress plays a crucial role in ovarian physiology and pathology, yet its dynamic changes across the estrous cycle remain unclear. This study aimed to investigate oxidative stress in rat ovarian tissue during the stages of the estrous cycle through histological and biochemical analyses. Vaginal smears identified estrous cycle stages, and ovarian tissues were examined histologically under a light microscope. Follicle counts, corpus luteum (CL) classification, oxidative stress marker (8-hydroxy-2'-deoxyguanosine/8-OHdG) staining, and apoptotic activity (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-nick end labeling/TUNEL) staining were analyzed. Serum malondialdehyde (MDA) and superoxide dismutase (SOD) activity was measured. Results showed strong 8-OHdG positivity in follicular epithelial cells surrounding the oocyte, granulosa cells of antral follicles, and CL cells. The detection of 8-OHdG positivity in CL cells, in both the nuclei and cytoplasm, suggests that oxidative stress affects both nuclear and mitochondrial DNA. Serum MDA levels were highest during estrus, while SOD activity was highest during metestrus. The increase in oxidative stress was associated with ovulation during estrus, while variations in SOD activity reflected changing defense mechanisms throughout the cycle. 8-OHdG positivity was high in follicular and luteal cells during CL regression, indicating ROS impact on follicular development and luteal function. Apoptotic cells were present mainly in antral follicles and luteal cells. These findings highlight the critical role of oxidative stress in ovarian function, with potential implications for fertility regulation and reproductive medicine. With rising oxidative stress levels, alternative cell death mechanisms likely contribute alongside apoptosis during CL regression.

Sweet taste is mediated by type II taste bud cells (TBCs), which express the heterodimeric taste receptor composed of type 1 members 2 and 3, a G protein-coupled receptor. Activating this receptor triggers phospholipase Cβ2 (PLCβ2)-dependent signaling, depolarizes cell membrane, and leads to ATP release via calcium homeostasis modulator 1 and 3 channels. However, the number of sweet-responsive cells within individual fungiform taste buds remains poorly understood. To quantify the number of sweet-responsive TBCs, we developed a novel method using biocytin uptake as an indicator of membrane depolarization. The apical side of peeled mouse lingual epithelia was stimulated with 1 M sucrose or 30 mM saccharin, while biocytin was applied to the basolateral side. Sweet stimulation significantly increased the number of biocytin-labeled cells compared to deionized-water controls. Biocytin labeling was observed primarily in PLCβ2-positive type II cells, with additional labeling in PLCβ2 and synaptosomal-associated protein 25-negative cells, suggesting the involvement of type II and, likely, type I cells. On average, 11% of type II cells per taste bud were sweet-responsive; however, this proportion varied substantially across individual taste buds. These results indicate that sweet-responsive cells form a subset of type II cells and are distributed heterogeneously among fungiform taste buds. Such heterogeneity may reflect divergent tuning properties and contribute to robust sweet taste perception. Given the short lifespan and continuous turnover of TBCs, asynchronous renewal of sweet-responsive cells across taste buds may help maintain sweet sensitivity by ensuring that some sweet-sensitive cells are consistently present.

Ovarian hyperstimulation syndrome (OHSS) is a serious complication commonly encountered in patients with infertility undergoing ovulation induction therapy. This study investigates histomorphological and biochemical effects of melatonin in an experimental OHSS model. Rats were divided into four groups: control group, controlled ovarian stimulation group (COS), ovarian hyperstimulation syndrome group (OHSS), and ovarian hyperstimulation syndrome + melatonin group (OHSS + melatonin). OHSS was induced in the OHSS and OHSS + melatonin groups by pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG) injections, followed by melatonin treatment administered intraperitoneally at a dose of 50 mg/kg only in the OHSS + melatonin group. In the OHSS group, ovarian weight increased and the number of atretic follicles also rose, while melatonin treatment improved these conditions. Histological analysis showed that melatonin preserved ovarian structure and supported follicular development. Serum estradiol levels were significantly higher in the OHSS group compared with the control group, but melatonin treatment reduced these levels significantly. Peritoneal fluid levels of vascular endothelial growth factor (VEGF) and interleukin (IL)-6 were elevated in the OHSS group, but melatonin treatment decreased these levels. Additionally, melatonin reduced follicular atresia and increased the number of Graafian follicles. In conclusion, melatonin improved the biochemical and histological markers of OHSS, providing protective effects on ovarian function. These findings suggest that melatonin could be a potential therapeutic agent for the treatment of OHSS. However, further clinical and experimental studies are needed to investigate its effects.

Chronic wounds present a major clinical challenge due to impaired healing and prolonged inflammation. This present study aimed to develop and assess a platelet-rich plasma (PRP)-loaded decellularized skin-derived matrix scaffold (SDMP) for enhanced wound healing. A total of 40 male Sprague-Dawley rats were randomly planned to four groups (n = 10 per group): untreated control, PRP, decellularized skin-derived matrix (SDM), and PRP-loaded SDM (SDMP). Full-thickness excisional wounds were created on the dorsal surface of each animal and treatments were applied accordingly. Tissue sampling was performed at two time points-day 7 and day 14 post-injury-with five animals per group euthanized at each time point. Histological evaluations included assessment of newly formed epidermal length, dermal thickness, and collagen density. Biomechanical properties of the regenerated skin were analyzed on day 14 using tensile strength testing. In addition, concentrations of key regenerative (TGF-β1, VEGF) and pro-inflammatory (TNF-α, IL-1β) cytokines in wound tissues were quantified via ELISA. The SDMP-treated group showed significantly enhanced wound closure, improved re-epithelialization and dermal regeneration, greater collagen deposition, and superior tensile strength compared with other groups (p < 0.05). Moreover, cytokine analysis revealed a favorable shift in the wound microenvironment characterized by elevated growth factors and reduced inflammatory mediators (p < 0.05). In conclusion, the PRP-loaded SDMs provides a bioactive and biocompatible platform that significantly improves full-thickness skin diabetic wound healing. This approach holds promise for future translational applications in regenerative medicine.