Histochemistry and Cell Biology最新文献

Telocytes are specialized interstitial cells characterized by their unique structure, which features a relatively small cell body and long cytoplasmic projections, called telopodes. Formerly referred to as interstitial Cajal-like cells, telocytes are capable of forming a complex communication network between various stromal and epithelial cell types. Despite their positive staining for CD34 and vimentin antibodies, the mesenchymal origin of these cells, as well as whether telocytes should be considered distinct cell populations or just a subpopulation of other stromal cells, remains uncertain. Telocytes have been shown to perform various functions, ranging from establishing complex three-dimensional networks, serving as an important component of stem cell niches and playing a huge role in the formation of tissue barriers, to serving as one of the key regulators of cell differentiation, having immune functions, and taking part in angiogenesis and even in organ morphogenesis. The functional diversity exhibited by telocytes in different tissues makes their study more complicated, and the exact molecular mechanisms underlying their function remain inadequately understood. As a new and intriguing field of research, telocytes hold considerable promise for improving our understanding of connective tissue physiology.

Type 1 diabetes mellitus (T1DM) is associated with oxidative stress and inflammation in the liver, which contribute to hepatocellular damage. However, the molecular mechanisms driving this process remain poorly understood. ADAMTS-13, a metalloprotease involved in vascular homeostasis, has been implicated in tissue remodeling and apoptosis. This study explores the potential link between ADAMTS-13 and apoptosis in T1DM-induced liver injury. Diabetes was induced in Wistar albino rats via streptozotocin (STZ) injection, and liver tissues were examined using immunohistochemical staining for ADAMTS-13 and apoptotic markers, including caspase-3, caspase-8, caspase-9, and TNFR1. Expression levels were compared between diabetic and control groups to assess correlations with apoptotic pathways. ADAMTS-13 expression was significantly elevated in the diabetic group. Apoptotic markers also showed a significant increase (p < 0.05). Notably, caspase-9 expression was more prominent in hepatocytes, indicating activation of the intrinsic apoptotic pathway, while caspase-8 and TNFR1 were predominantly expressed in sinusoidal and vascular endothelial cells, suggesting involvement of the extrinsic pathway. This study is the first to demonstrate a link between ADAMTS-13 expression and apoptosis in T1DM-related liver injury. These findings suggest that ADAMTS-13 may play a role in modulating apoptotic responses, although its exact function remains to be clarified. Further mechanistic studies are warranted to determine whether ADAMTS-13 directly influences apoptosis or represents an adaptive response to hepatic stress. Additionally, the results highlight the potential of ADAMTS-13 as a biomarker for diabetes-associated liver dysfunction.

Extracellular matrix reorganization, a concurrent process of endometrial decidualization, has garnered widespread recognition. However, our understanding of this process remains limited. In this study, we aimed to investigate the expression, spatial distribution, and reorganization of fibrillar collagens, elastin, and lysyl oxidases within the decidua. Using second harmonic generation imaging, we successfully recorded fibrillar collagen reorganization between preimplantation and decidualized endometrium. Upon embryo implantation, the fibrillar collagens align themselves parallel to the direction of embryo invasion. Furthermore, we employed confocal imaging analysis to reveal distinct expression and spatial distribution patterns of elastin and lysyl oxidase-like enzymes. Elastin expression begins to manifest surrounding the implanting embryo, extends into the decidua, and exhibits a high concentration in the mesometrial region after gestational day 8. All lysyl oxidase-like enzymes are localized within the decidua, although they exhibit varying expression patterns. To gain further insights, we utilized an in vitro stromal cell decidualization model and provided compelling evidence that stromal cells serve as the primary source of the extracellular matrix components during endometrial decidualization. Additionally, we demonstrated that the genes encoding factors involved in the synthesis, processing, and assembly of fibrillar collagen and elastic fibers exhibit differential expression patterns during in vitro decidualization. Genes such as asporin, decorin, thrombospondin 2, fibulin 2, fibulin 5, and lysyl oxidase show significant induction during in vitro decidualization. In summary, our comprehensive analysis provides a detailed evaluation of the expression, spatial distribution, and reorganization of fibrillar collagens, elastin, and lysyl oxidases during the process of endometrial decidualization.

Ascl1 (Mash1), a bHLH transcription factor, is widely expressed by neuronal progenitors. The gene plays a key role in the differentiation of the autonomic nervous system, i.e., sympathetic, parasympathetic, and enteric ganglia; all of which are derived from neural crest cells. In Ascl1-null mutants, defective development of these ganglia is induced. The differentiation of neuroendocrine cells, including the carotid body, ultimobranchial body and thyroid C cells, the neuroepithelial body in the lung, and the adrenal medulla, is also controlled by Ascl1. Although the carotid body glomus cells and adrenal medulla are derived from neural crest, the ultimobranchial body is from pharyngeal endoderm and the neuroepithelial body is from endodermal epithelium. A targeted mutation of Ascl1 results in complete loss or failure in differentiation of these neuroendocrine cells. Furthermore, the development of olfactory epithelium and bulbus is regulated by Ascl1. In the central nervous system, Ascl1 is expressed in the arcuate and ventromedial nuclei, telencephalon, and dopaminergic neurons such as locus coeruleus and nucleus tractus solitarius. The elimination or atrophy of these regions are induced in Ascl1-null mutants. All cells and tissues affected by the deficiency of Ascl1 express catecholamines and/or serotonin. The Phox2b or/and Hes1 genes are required for regulation of Ascl1 expression. Phox2b stimulates the expression of Ascl1, whereas Hes1 represses gene expression.

Chondroprogenitors derived from articular cartilage offer a promising approach for treating cartilage pathologies owing to their high chondrogenic and low hypertrophic potential. Optimizing holding conditions and parenteral solutions for transporting these cells from the processing to the transplantation site is crucial to enable their clinical application. This study assessed the viability, molecular phenotype maintenance, and differentiation potential of human fibronectin adhesion assay-derived chondroprogenitors (FAA-CPs) suspended in five parenteral solutions-(a) normal saline (NS), (b) plasma-lyte A, (c) 5% dextrose, (d) hyaluronic acid (HA), and (e) platelet-rich plasma (PRP) at 5 × 10⁶ cells/ml and stored at 4 °C for 0, 6, and 12 h. FAA-CPs were isolated from nondiseased cartilage samples (n = 3). The assessments done included viability by Vi-CELL BLU assay and calcein AM-propidium iodide; surface chondrogenic marker expression; and differentiation potential by confirmatory staining. The cells exhibited positive mesenchymal stem cells (MSC) markers, moderate-to-high chondrogenic marker expression, and trilineage differentiation potential. Viability was preserved in NS, plasma-lyte A, 5% dextrose, and HA, but significantly declined in PRP. All groups retained multilineage potential, with higher Safranin-O uptake and collagen II accumulation in NS, plasma-lyte A, and 5% dextrose, suggesting enhanced chondrogenesis. Notably, 5% dextrose exhibited minimal collagen X accumulation, indicating low hypertrophic potential. NS, plasma-lyte A, and 5% dextrose poses to be optimal parenteral solutions for the formulation of chondroprogenitor suspensions, with a holding time of up to 12 h. Factoring lower hypertrophic potential, 5% dextrose seems to stand out among the other solutions as a cell-delivery vehicle for the treatment of cartilage diseases.

Here, we aimed to define adipogenic, osteogenic, and chondrogenic media for the differentiation of murine mesenchymal stromal cells (MSCs). We used differentiation media formulations optimized for use with human bone marrow-derived MSCs as the starting medium and modified the contents of the differentiation media by testing the differentiation potential of the Op9 stromal cell line, a murine enhanced green fluorescent protein transgenic (eGFP+) bone marrow-derived MSC line, and freshly isolated murine BALB/c bone marrow MSCs. We optimized the media through assessment of (immuno)histological staining and assessment of adipogenic, osteogenic, and chondrogenic differentiation-specific gene expression. Adipogenic differentiation was found to improve in a high-glucose setting, whereas chondrogenic differentiation increased in the presence of insulin-like growth factor-1 (IGF-1). Modifications made to the osteogenic media did not further improve the differentiation capacity of the murine MSCs. In conclusion, using minor changes to existing protocols, we found it possible to increase the overall efficacy of murine MSC differentiation. These modified protocols will further aid in a better understanding of the true differentiation capacity of these cells, and improvement of tissue engineering protocols.

Secreted Frizzled-related proteins (SFRPs) are a small, ancient family of extracellular signaling pathway agonists and antagonists. As part of the intercellular communication system, they regulate signaling pathways significant for animal development including Wnt and BMP. This review summarizes the current knowledge of SFRP functions, focusing on recent discoveries that offer new insights into the role of interactions between SFRPs and Wnt signaling pathways in morphogenesis.

There are pertinent studies on the relationship between matrix metalloproteinases (MMPs) and muscle cell differentiation in vitro, but currently, there are few in vivo studies exploring MMP expression in chicken muscle during different stages of differentiation. Therefore, we aimed to investigate in vivo whether MMP-2, MT1-MMP, and MMP-9 are expressed in the pectoral muscle during the fetal stages of Ross chicken development on days E11, E15, and E19. Our results demonstrated that, in contrast to earlier reports in vitro, myocyte fusion occurs on E11, while on E15 and E19, secondary muscle wave formation is occurring. MMP-2, on the other hand, appears to be expressed more than MT1-MMP throughout the evaluated days, whereas MMP-9 is not expressed at any point. Additionally, serine was discovered as an unexpected finding in the zymogram analysis. In conclusion, considering the experimental limitations of the present study, it was found that MMP-9 is not expressed during the evaluated ages of in vivo pectoral muscle development in Ross chickens, indicating a limited role for this enzyme in muscle differentiation during the fetal period. In contrast, the expression of MMP-2 and MT1-MMP is crucial, as these are detected from myocyte fusion at E11 to the development of myotubes observed at E19, reflecting their significant role in muscle differentiation within the Ross chicken lineage.

Intracellularly expressed integrin associated proteins (IAPs) play pivotal role in facilitating cellular adhesion and survival. The integrin linked kinase (ILK)-PINCH-parvin (IPP) complex regulates cell-matrix interactions crucial for tissue development and homeostasis by functioning as an adapter between integrin and actin cytoskeleton. This review provides a compiled structural and functional insight into the IPP complex and its interacting partners, highlighting its conservation and signalling pathway, addressing a cross-talk across its homologues. Finally, the study sheds light on the association of the complex members with biological processes and disease progression, thus potentiating further exploration of the IPP complex within the integrin signalling pathway.

Hepatocytes play a vital role in maintaining iron homeostasis, which can be compromised by poor diet and lifestyle. This study aimed to assess the combined impact of high-fat diet (HFD), alcohol, and fructose intake on liver injury and iron metabolism. Male Sprague-Dawley rats (5‒7 weeks old, weighing 160‒180 g) were randomly assigned to three groups: regular chow, HFD, and a combined HFD with 30% ethanol and 30% fructose (HF‒EFr), and were maintained for 4 or 8 weeks. Liver injury was assessed via histopathological staining and serum aminotransferase levels. Iron homeostasis was evaluated by measuring plasma iron levels, hepatic iron deposition, and the expression of key iron-regulatory proteins. Markers of inflammation, oxidative stress, and macrophage activation, such as CD14, ED-1 (CD68), HIF1α, and STAT3 activation, were also examined. Urinary levels of ferritin-L and lipocalin-2 were measured. The HF‒EFr group exhibited severe liver injury, characterized by steatohepatitis and hepatocyte ballooning, with significantly elevated serum aminotransaminase levels and a decrease in the AST/ALT ratio from 3:1 at week 4 to 2:1 at week 8, indicative of progressive hepatocellular damage. Increased serum CD14 and hepatic ED-1 (CD68) confirmed macrophage activation. Urinary ferritin-L and lipocalin-2 levels increased significantly compared with other groups, indicating systemic inflammation and renal involvement. In the HF‒EFr group, gene expression of ferroportin and ferritin was upregulated, accompanied by plasma iron depletion and increased hepatic iron deposition. Nuclear localization of ferritin subunits in hepatocytes was observed, along with elevated HIF-1α and cytokine levels, and activation of STAT3, suggesting an oxidative stress response in the HF‒EFr group. Chronic consumption of alcohol and fructose intensifies the dysregulation of iron metabolism and liver injury induced by a high-fat diet. These findings highlight the critical role of iron homeostasis in diet-induced liver disease and suggest that urinary biomarkers such as ferritin-L and lipocalin-2 may serve as noninvasive indicators of systemic inflammation and iron dysregulation. This study underscores the need for early detection strategies and long-term dietary interventions to limit metabolic liver disease progression.