Histochemistry and Cell Biology最新文献

Histological changes in skeletal muscle after heart failure have been widely investigated in the lower limbs, including slow-to-fast fiber type transition, fast fiber-predominant atrophy, reduced capillary number, and increased collagen content. However, histological changes in the upper limb muscles remain largely unexplored. Given the prognostic significance of grip strength and upper limb muscle mass in heart failure, elucidating these changes is essential. We aimed to investigate histological changes in forelimb muscles in a rat model of monocrotaline (MCT)-induced heart failure. Rats were assigned to control (vehicle-injected) or heart failure (MCT-injected) groups. Grip strength was measured on day 27, and histological analyses of the biceps brachii (BiB) and flexor digitorum profundus (FDP) were performed on day 28. Grip strength significantly reduced in the heart failure group. Both BiB and FDP exhibited significant atrophy of fast fibers without changes in slow fiber size. The BiB showed a reduced capillary-to-muscle fiber ratio and no change in fiber type, whereas the FDP showed a shift toward a faster fiber phenotype and no change in capillary number. Collagen content remained unchanged in both muscles. MCT-induced heart failure leads to fast fiber-specific atrophy in forelimb muscles, with muscle-specific differences in capillary and fiber type adaptations. These changes may underlie the impaired upper limb muscle functions in heart failure. While some findings are consistent with those in lower limb muscles, others differ, suggesting region- and muscle-specific responses. Thus, findings from a single muscle cannot necessarily be extrapolated to all skeletal muscles.

One of the most frequent reasons behind respiratory failure is acute lung injury (ALI). In response to endoplasmic reticulum stress (ERS), the protein known as stimulator of interferon genes (STING) triggers strong lung inflammatory reactions and damage. The current study evaluated the possible influence of platelet-rich plasma (PRP) on ALI through altering the cyclic GMP-AMP synthase (cGAS)-triggered STING/ERS/TANK-binding kinase 1 (TBK1)/interferon regulatory factor 3 (IRF3)/nuclear factor kappa B (NF-κB) pathway. Twenty-one adult male Wistar rats were arbitrarily divided into three sets of seven: (1) control (CTRL); (2) ALI, in which the rats were given intraperitoneal (i.p.) lipopolysaccharide (LPS) at 10 mg/kg once; and (3) ALI + PRP, in which, at 1 week after i.p. LPS injection, rats were injected (i.p.) with PRP every 3 days for 4 weeks. At the end of the experiment, blood samples and lung tissues were evaluated at biochemical, molecular, and histological levels. PRP caused downregulation of the cGAS-induced STING/ERS/TBK1/IRF3/NF-κB signaling pathway and lessened lung inflammatory and apoptotic insults. This was evident on microscopic examination of lung tissue with significantly decreased immunoreactivity of lung tissue caspase 3, NF-κB, and tumor necrosis factor-alpha. PRP is a promising biological therapeutic regimen against ALI.

The thyroid gland is a unique endocrine organ, composed of morpho-functional units called thyroid follicles, which are responsible for thyroid hormone (TH) biosynthesis, an iodination process demanding a highly oxidative yet protected environment. Despite primary cilium (PC) being observed in the thyroid gland more than a century ago, its precise role in thyroid activity remains rather unexplored. Given its strategic position at the apical surface of follicular epithelium, projecting into the lumen, PCs are crucial for the regulation of TH biosynthetic processes. Consequently, changes in thyroid function, either physiological or pathological, are reflected in PC characteristics. Similarly, defects in ciliogenesis are expected to lead to different pathological thyroid alterations. This review summarizes the current understanding of PC's involvement in regulating normal thyroid activity and its modifications in functional and neoplastic thyroid diseases. Particular focus will be given to the notable loss of PCs in certain types of thyroid cancer and the promising potential of their restoration as a tumor suppressor strategy in thyroid tumorigenesis.

E-cadherin is a key determinant of epithelial tissue architecture, and its inhibition has been linked to transcriptional reprogramming and cellular plasticity in epithelial cancers. However, the chromatin-level mechanisms driving these changes remain incompletely understood. EP300, a histone acetyltransferase and transcriptional coactivator, has been implicated in mediating epigenetic responses to cell-cell adhesion loss. We examined the genome-wide chromatin binding profile of EP300 in MCF7 breast cancer cells following functional inhibition of E-cadherin using a neutralizing antibody. Chromatin immunoprecipitation coupled with high-throughput sequencing (ChIP-seq) revealed 4128 EP300-enriched regions in control cells and 2943 in treated cells, with only 12 sites shared between conditions, indicating widespread redistribution. These changes localized to gene loci associated with epithelial identity (e.g., CDH1, CD46) and were replaced by increased occupancy at mesenchymal (CDH2, LOX) and pluripotency-associated loci (SEMA3E, MET). Differential binding was validated by chromatin immunoprecipitation coupled with quantitative polymerase chain reaction (ChIP-qPCR). Notably, EP300 protein levels remained unchanged, suggesting a redistribution rather than expression-level regulation. Our findings suggest that E-cadherin inhibition is associated with early changes in EP300 chromatin localization, particularly at loci linked to epithelial-mesenchymal transition (EMT) and pluripotency. These changes may reflect an early chromatin-level response to altered cell adhesion, warranting further functional investigation.

Humans are increasingly exposed to silica nanoparticles (SiNPs) from environmental and occupational sources, raising significant concerns about their safety. Despite growing applications, data on their neurotoxic effects, particularly those involving oxidative/nitrosative imbalance and striatal damage, remain limited. This study aimed to elucidate the mechanisms of SiNP-induced neurotoxicity in the striatum, a brain region crucial for motor control and learning, using a rat model. Subacute intraperitoneal administration of SiNPs (25 and 100 mg/kg bw/day for 28 days) resulted in a marked increase in lipid peroxidation (LPO), reactive oxygen species (ROS), nitrite (NO), and protein carbonyl content, alongside a significant reduction in the activity of antioxidant enzymes, viz. superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), as well as glutathione (GSH). Additionally, cholinergic [acetylcholinesterase (AChE) and b1utyrylcholinesterase (BChE)] and membrane-bound adenosine triphosphate (ATP)ase (Na⁺/K⁺, Mg²⁺, and Ca²⁺ ATPase) activities were significantly reduced in the striatum. Immunofluorescence and immunohistochemistry revealed elevated expression of antioxidant markers, particularly nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). Quantitative reverse-transcriptase real-time polymerase chain reaction (qRT-PCR) analysis demonstrated upregulation of pro-apoptotic genes (Bax, p53, caspase-9/3) and downregulation of the anti-apoptotic gene Bcl-2, leading to an increased Bax/Bcl-2 ratio. Complementary in silico molecular docking studies showed that SiNPs exhibit notable binding affinities toward Nrf2, HO-1, AChE, and BChE. Collectively, these findings indicate that SiNPs induce striatal neurotoxicity via oxidative/nitrosative stress-mediated apoptosis, involving activation of Nrf2/HO-1, cholinergic disruption, and apoptotic signaling pathways.

In this study, the effect of targeting plasma membranes by depleting cholesterol and inhibiting sphingolipid synthesis using methyl-beta-cyclodextrin (MβCD) and myriocin, respectively, on blood-brain barrier (BBB) integrity was investigated in rats under septic conditions induced by cecal ligation and puncture (CLP). Horseradish peroxidase (HRP) and Evans blue (EB) tracers were used to assess BBB permeability. Caveolin (Cav)-1, claudin-3 and -5, and glucose transporter (Glut)-1 expression was assessed using immunofluorescence staining. In septic rats, MβCD or myriocin significantly attenuated the increased BBB permeability to both tracers. Upon MβCD administration, Cav-1 immunoreactivity decreased in the cerebral cortex; however, it increased markedly in the hippocampus in CLP-operated animals. MβCD and myriocin treatments to septic rats increased claudin-3 immunoreactivity in brain regions, and the difference reached statistical significance with the former treatment. In septic rats, claudin-5 immunoreactivity in brain regions was significantly decreased by MβCD and increased by myriocin. In CLP-operated animals, MβCD and myriocin treatments increased Glut-1 immunoreactivity in the brain regions, with the differences reaching statistical significance in the cerebral cortex and hippocampus by the former, while in only the cerebral cortex by the latter treatment. In conclusion, our results suggest that altering lipid profiles of plasma membranes by MβCD and myriocin can alleviate BBB disruption in septic conditions and, hence, may account for a novel therapeutic modality.

The establishment of reliable in vitro oral mucosa models is essential for advancing studies in epithelial barrier function, wound healing, and host-microbe interactions. However, the widespread use of immortalized cell lines such as HaCaT or TR146 limits physiological relevance owing to altered differentiation profiles and genetic drift. In this study, we developed a robust mechanical-enzymatic protocol for isolating and expanding primary human gingival keratinocytes from healthy gingival explants without feeder layers. The resulting cells demonstrated high viability, maintained consistent proliferative capacity across passages, and exhibited characteristic cobblestone morphology. Comprehensive phenotypic validation included immunofluorescence and immunohistochemistry confirming strong expression of epithelial markers CK18, AE1/AE3, and MUC1, with absence of the mesenchymal marker vimentin. Transcriptomic analysis using RT-qPCR corroborated epithelial lineage fidelity, revealing stable MUC1 expression and lack of MUC5AC transcripts, indicative of a nonglandular phenotype. Metabolic competence was supported by WST-1 assays that correlated strongly with manual cell counts, underscoring functional viability. Importantly, AGS and 293T/17 cell lines were processed in parallel as orthogonal controls to confirm assay specificity and lineage discrimination. Under rigorously standardized, within-laboratory conditions, our workflow yielded high interdonor concordance in epithelial identity and growth kinetics across a young-adult cohort (n = 3), supporting its use as a practical primary-cell platform for downstream applications. Generalizable reproducibility-across age strata, operators, and sites-will require formal, preregistered multicenter validation. By mitigating limitations inherent to immortalized lines, this approach enables more accurate investigations of epithelial biology and strengthens the reliability of in vitro experimental systems relevant to oral regenerative medicine and mucosal immunology.

Coenzyme Q10 (CoQ10) is an antioxidant known for its potential protective effects against various types of cardiac injury. The aim of this study was to determine the protective effects of CoQ10 on cardiomyocytes, telocytes and progenitor cells in rats with isoproterenol (ISO)-induced cardiotoxicity. A total of 60 Sprague-Dawley rats were divided into six groups (n = 10): Group I: control, Group II: saline control, Group III: oil control, Group IV: ISO, Group V: CoQ10, Group VI: ISO and CoQ10. Isoproterenol was administered intraperitoneally at a dose of 85 mg/kg twice on the eighth and ninth days, and CoQ10 was administered by oral gavage at a daily dose of 20 mg/kg. Heart tissue samples were collected and analysed at the end of the study. CoQ10 reduced ISO-induced cardiac degeneration, necrosis, inflammatory infiltration and fibrosis. The stimulation of cell cycle activators such as histone H3 and proliferating cell nuclear antigen (PCNA) was found to play a role in the repair of cardiac injury in the cardiomyocytes known to be postmitotic. An increase in c-Kit and CD34 stem cells was seen with the beneficial effect of CoQ10 (P < 0.05). The presence of telocytes, which play an important role in cardiac regeneration, was visualised by double CD34-c-Kit and CD34-vimentin immunofluorescence staining. The results indicate that CoQ10, through its antioxidant effect, ameliorates cardiac lesions caused by ISO, induces a limited number of cell cycle activators in cardiomyocytes and interstitial cells and has a positive effect on the increase of progenitor cells in the heart.

Cancer-associated fibroblasts (CAFs) represent an important component of the cancer ecosystem, influencing the broad scale of biological properties of tumour cells, including the capacity for metastasis formation. An important CAF subpopulation, known as myCAFs, typically expresses α-smooth muscle actin. Transcriptomic analysis demonstrated that activated fibroblasts isolated from various pathological tissues also express the ACTG2 gene encoding γ-smooth muscle actin. This was further validated by immunocytochemistry. Using the scratch test in vitro, it was possible to demonstrate that γ-smooth muscle actin may be associated with the epithelial-mesenchymal transition, which was also shown by transcriptomic analysis. The presence of γ-smooth muscle actin-positive fibroblasts in histopathological sections of human tumours verified the expression of this protein as a new potential marker of CAFs.