Browsing by Subject "Stroma"

Now showing 1 - 3 of 3
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    Diversity and dynamics of fish ovaries: Insights into reproductive strategies, hormonal regulation, and ovarian development
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2025) Mokhtar, Doaa M.
    Fish ovaries exhibit a remarkable diversity in shape, size, and organization, reflecting the myriad reproductive strategies employed by different species. This review delves into the intricate biology of fish ovaries, highlighting their structural diversity and the hormonal regulation that governs ovarian development and oocyte maturation. Key hormones include pituitary gonadotropins (GTHs) and maturation-inducing hormones (MIHs), which initiate oocyte growth and maturation. GTHs stimulate ovarian production of estradiol-17β and 17α,20β-DP, which induce oocyte maturation via MPF formation. Sex steroids like estrogens and progestogens, synthesized from cholesterol, play crucial roles. Other hormones, including growth hormone, prolactin, thyroid hormones, IGFs, ACTH, and melatonin, influence ovarian activity. The review also explores the varied reproductive strategies among fish, including oviparity and viviparity, and discusses how environmental factors like water temperature and photoperiod influence ovarian histology. Understanding the complex interplay between these factors is essential for advancing fisheries management, conservation, and aquaculture practices. Additionally, the evolutionary trajectory of fish ovaries underscores their adaptation to diverse ecological niches, contributing to the survival and reproductive success of fish species. The ovarian stroma provides structural support and houses various cell types, including dendritic cells (DCs), endocrine cells, and telocytes, contributing to follicle growth and hormone production, essential for reproductive success in fish. Fish ovaries are a crucial aspect of fish biology, with their structure and function intricately regulated by hormonal, environmental, and seasonal factors.
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    Stroma composition and proliferative activity are related to therapy response in neoadjuvant treated pancreatic ductal adenocarcinoma
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2021) Haeberle, Lena; Insilla, Andrea Cacciato; Kap, Anne-Christine; Steiger, Katja; Schlitter, Anna Melissa; Konukiewitz, Björn; Demir, Ihsan Ekin; Friess, Helmut; Esposito, Irene
    Background. Tumor regression grading (TRG) based on histopathology is the main tool to assess therapy effects after neoadjuvant therapy (NAT) of pancreatic ductal adenocarcinoma (PDAC). However, reliable markers to distinguish therapy effects from preexisting tumor features are lacking. The aim of this study was the characterization of PDAC after NAT, focusing on the stroma. Material and Methods. Tissue samples from patients resected for PDAC after NAT (n=27) were analyzed. TRG was assessed using the Royal North Shore (RNS) system. Stromal composition was evaluated by Movat's stain. Immunohistochemistry (IH) for Ki-67 and five previously established stroma markers (alpha-Crystallin B, alpha-Smooth muscle actin (alpha-SMA), Neurotrophin-3 (NT-3), SPARC and Tenascin C) was also performed. Results were compared with therapynaïve PDACs (n=10). Results. Most cases showed a moderate response (RNS 2; 74%), while 15% displayed a poor response (RNS 3), and 11% a good response (RNS 1). No complete response was observed. Poor regression was associated with mucin-rich stroma, while good regression was associated with collagen-rich stroma. Cases with poorer therapy response had significantly higher proliferation. Higher peritumoral staining intensity for alpha-SMA and Tenascin C also showed a trend towards an association with poor regression. Conclusions. Similar to the stroma in therapy-naïve PDAC, the stroma of PDAC after NAT is heterogeneous. Distinguishing between desmoplastic stroma and therapy-induced fibrosis by single markers is not possible. Movat's pentachrome stain, IH for Ki-67, and to some extent for Tenascin C and alpha-SMA, can help detect poor histopathological response to NAT.
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    Transcription regulators are transiently expressed during the prostate gland adaptation to the hypoandrogenic environment
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2019) Nishan, Umar; Rosa Ribeiro, Rafaela; Lenz Cesar, Carlos; Carvalho, Hernandes F.
    The high incidence of prostatic diseases, including malignant tumors, makes the understanding of prostate biology very important. Androgen deprivation, blockade by orchiectomy, or chemical castration causes prostate and tumor shrinkage. The gene networks involved in a cell type-specific fashion are rather unknown. This work was undertaken to identify genes with annotated function in transcription regulation that might define transitions in gene expression. A total of 15 potential regulatory genes were identified. Validation by qRT-PCR showed that Zfp703 and Arid1a exhibit expression maxima at day 1; Ash2l, Nelf, Pbx3, Eya2 at day 4; Dmrt2 at day 5 and Lbh and Sox1 at day 7 after castration. Using immunohistochemistry, we further determined that PBX3 was found in both stromal and epithelial cells, whereas ARID1A and NELF were restricted to the epithelium, and DMRT2 and EYA2 were exclusively found in the stroma. Though the proteins ZFP703 and ASH2l were not found in any experimental condition, their mRNAs were located by in situ hybridization in both epithelium and stroma. In conclusion, androgen deprivation triggers the expression of temporally regulated gene sets in both epithelial and stromal cells. These gene subsets will help establish the regulatory gene expression programs orchestrating the castration-induced remodeling of the prostate gland, and represent putative targets to increase the efficacy of androgen-deprivation to induce epithelial (and cancer) cell death.