Angiogenic and anti-angiogenic factors during the post-hatching growth of the quail (Coturnix coturnix japonica) spleen

Vascular endothelial growth factor (VEGF) family members are responsible for endothelial cells' growth, proliferation, migration, angiogenesis, vascular permeability, and differentiation and proliferation of non-endothelial cell types. VEGF and its receptors are found in mammalian lymphoid organs. The present study was conceived to determine (a) the presence and localization of angiogenic VEGF and its receptors (Fms-like tyrosine kinase 1 [Flt1/fms], fetal liver kinase 1 [Flk1]/kinase insert domain receptor [KDR], Fms-like tyrosine kinase 4 [Flt4]) and vascular endothelial growth inhibitor (VEGI) in the quail spleen; and (b) whether their expressions in the spleen components change during the post-hatching growth of the organ, using immunohistochemistry. Immunohistochemical stainings showed that VEGI, VEGF, and VEGF receptors were expressed in many components, including the vascular endothelial and smooth muscle cells, ellipsoid-associated cells (EACs), and immune cells, of quail spleen and that VEGF and its receptors' immunostaining intensity scores (ISs) varied depending on the post-hatching growth period, while VEGI-IS did not change. In addition, ISs of VEGI, VEGF, Flt1/fms, and Flt4 in EACs were weak to moderate, while flk1/KDR-IS in EACs adjacent to the capsule of Schweigger-Seidel sheaths (ellipsoids) was higher than other proteins, supports a more important and specific role of Flk1/KDR in the EAC function. These specific expressions of VEGI, VEGF, flt1/fms, flk1/KDR, and flt4 proteins in splenic cell types suggest their particular roles, in the functional development of splenic components and thus, are critical to post-hatching maturation of quail spleen. These findings indicate that the expression levels of VEGF, Flt1/fms, and Flt4, except Flk1/KDR, are low in the quail spleen, and only a few components of the spleen express VEGF, Flt1/fms, and Flt4 under normal conditions.

Differential distribution of intermediate filament proteins in the bovine and ovine tongues

Intermediate filaments constitute the most heterogeneous class among the major classes of cytoskeletal proteins of mammalian cells. The 40 or more intermediate filament proteins have been classified into five types which show very specific rules of expression in specialized cell types. This study aimed to investigate the immunohistochemical distribution of cytokeratins (CKs) 8, 18, and 19 as well as the intermediate filaments vimentin, laminin, and desmin in bovine and ovine tongues. Immunohistochemical staining was performed for CKs 8, 18, 19, vimentin, laminin, and desmin. Our results revealed similar immunostaining intensity and distribution among various CKs, contrasting with distinct patterns for vimentin, laminin, and desmin. Immunoreactions were primarily localized in serous acini and ductal epithelium for cytokeratins, while vimentin and laminin were evident in connective tissue, endothelium, serous acini, and desmin in striated and smooth muscles. This study highlighted the absence of CKs 8, 18, 19, vimentin, and desmin in the lingual epithelium of bovine and ovine tongues. These findings enabled the classification of epithelial cells based on their specific cytokeratin patterns. Furthermore, vimentin was identified in mesodermal tissues and organs, desmin in muscle tissue, and laminin played crucial roles in basement membrane formation, nerve tissue regeneration, innervation of epithelial taste buds, and tissue separation and connection. Our findings provide essential insights into intermediate filament dynamics at the cellular and tissue levels. They serve as a foundation for future studies using systematic molecular biological techniques in this field.

The immunolocalization of cadherins and beta-catenin in the cervix and vagina of cycling cows

The adherens junctions (AJs) maintain the epithelial cell layers' structural integrity and barrier function. AJs also play a vital role in various biological and pathological processes. AJs perform these functions through the cadherin-catenin adhesion complex. This study investigated the presence, cell-specific localization, and temporal distribution of AJ components such as classical type I cadherins and beta-catenin in the cow cervix and vagina during the estrous cycle. Immunohistochemistry and Western blot analysis results demonstrated that beta-catenin and epithelial (E)-, neural (N)-, and placental (P)-cadherins are expressed in the cow cervix and vagina during the estrous cycle. These adhesion molecules were localized in the membrane and cytoplasm of the ciliated and non-ciliated cervical cells and the stratified vaginal epithelial cells. Positive immunostaining for P-, N-cadherin, and beta-catenin was also observed in the vascular endothelial cells of the cervical and vaginal stroma. Quantitative immunohistochemistry examinations revealed that in the cervical and vaginal epithelia, P-cadherin's optical density values (ODv) were the highest; in contrast, the N-cadherin ODv were the lowest. The ODv of P-cadherin and beta-catenin in the cervical epithelium and E-cadherin in the vagina were significantly higher in the luteal phase versus the follicular phase of the estrous cycle. Furthermore, the ODv of P-cadherin, N-cadherin, and beta-catenin in the cervix's central and peripheral epithelial regions were different during the estrous cycle. These findings indicate that classical cadherins and beta-catenin in the cervix and vagina exhibit cell- and tissue-specific expression patterns under the influence of estrogen and progesterone hormones during the estrous cycle.

Epidermal growth factor receptors and their ligands are expressed in the spleen of the Japanese Quail (Coturnix coturnix japonica) during the post-hatch period

1. The epidermal growth factor (EGF) family plays an important role in the development, differentiation, migration and apoptosis of cells, as well as in wound healing, which are all essential to the viability of multicellular organisms. The avian spleen is a principal organ of systemic immunity and its importance in disease resistance is presumably accentuated by the scarcity of avian lymph nodes.2. The aim of this study was to determine whether EGF receptors (ErbB1-4) and their ligands (EGF, AREG and NRG) are expressed in the structural components of the quail spleen during the post-hatch period. At each selected age, from 1 d to 7, 14, 21 and 60 d, 10 quails were euthanised under ether anaesthesia and their spleens were fixed in a 10% formaldehyde-alcohol solution. Following routine histological processing, the streptavidin-biotin-peroxidase method was used for immunohistochemical examination.3. Strong cytoplasmic immunoreactions for ErbB2, ErbB4 and NRG were observed in the ellipsoid associated cells (EAC) of the quail spleen throughout the post-hatch period. This immunoreactivity in the EAC increased after the 7th d post-hatch. ErbB1 and ErbB3 immunoreactions were relatively similar and weak in all components of the spleen during the post-hatch period. Some immune cells of the peri-arterial lymphatic sheath (PALS) and peri-ellipsoidal lymphatic sheath (PELS) showed positive immunoreactivity for the ErbB receptors and their ligands. In the vascular smooth muscle cells, immunoreactivity for ErbB2 was stronger than that for the other ErbB receptors and their ligands.4. The data showed that ErbB receptors and their ligands (EGF, AREG and NRG) are expressed by different structural components of the quail spleen during the post-hatch period.

Distribution of cytoskeletal proteins in the cat testis during the pre-pubertal and post-pubertal periods

Cytoskeletal proteins not only define the shape of cells, but also have critical roles in their proliferation, migration and motility, as well as in the establishment and maintenance of tissue organization and integrity. Furthermore, these proteins influence the physiological processes of the male reproductive system and are found in the structure of some cells. This study aimed to determine differences between the pre- and post-pubertal periods for the localization and distribution of actin, desmin, vimentin and cytokeratin-18 in the testes, epididymides and ductus deferentes of Persian and Turkish Angora and Van cats, using immunohistochemistry. The study material was grouped as belonging to the pre-pubertal and post-pubertal periods. The tissue samples of both groups were subjected to routine histological processing and embedded in paraffin. Serial sections cut from the paraffin-embedded tissue blocks were immunohistochemically stained with the indirect streptavidin-biotin complex method. Immunohistochemical findings demonstrated that there was no difference between the pre- and post-pubertal periods for the staining intensity and distribution of the proteins actin, vimentin, desmin and cytokeratin-18 in Persian and Turkish Angora and Van cats. On the other hand, differences were detected between the pre- and post-pubertal periods for the cellular expression and localization of these proteins in the testes, epididymides and ductus deferentes. Thus, the study results suggest that, based on the expression of actin, desmin, vimentin and cytokeratin-18 in the testes, epididymides and ductus deferentes during both periods, these molecular factors could have a contributory role in the development of the male reproductive system and the regulation of its physiological processes.

Expression of cadherins and some connective tissue components in cow uterus and placenta during pregnancy

The implantation and placental development processes are regulated with cell adhesion molecules and remodeling of the maternal endometrium's extracellular matrices (ECM) and fetal chorion. This study aimed to investigate the distribution and localization of some classical cadherins (E-, N-, and P-cadherins) and extracellular matrix components collagen type 5α1, fibronectin, and laminin in the cow placentomes during pregnancy using immunohistochemical and Western blotting analyses. The study results confirmed the expression of E- and P-cadherins, collagen type Vα1 (COLVα1), fibronectin, and laminin in the cow placentomes, but not N-cadherin. Throughout the pregnancy, E- and P- cadherins, COLVα1, and laminin were localized in the luminal and glandular epithelium of the inter-caruncular endometrium, caruncular epithelium, and the uninucleate (UNCs) and binucleate trophoblast giant cells (BNCs/TGCs). E- cadherin immunoreactivity in the first pregnancy period was strong in the UNCs while moderate in the BNCs/TGCs. However, it was weak in both trophoblast in the second and third pregnancy periods. In the fetal trophoblasts, P- cadherin and laminin immunostainings were more intense in the BNCs/TGCs than UNCs. The fetal and maternal stromal cells were also positive for P- cadherin, COLVα1, fibronectin, and laminin. The immunostaining intensity of COLVα1 and fibronectin in the stromal extracellular matrix of the placentomes decreased as the pregnancy progressed. The endothelia of fetal and maternal vessels were positive for all proteins. The presence and distinct localization of cadherins and ECM proteins in the cow placentome components support the role of these molecules in regulating placental cell growth, migration, and matrix production during pregnancy.

Immunolocalization of some HOX proteins in immature and mature feline testes

Homeobox (HOX) proteins are known for their critical role in body shape formation and tissue differentiation of developing vertebrate embryos. Recent research has shown that HOX proteins have many physiological roles such as cell proliferation, cell cycle, apoptosis and cell differentiation in adults, as well as the development of the vertebrate nerve and reproductive system. This study was conducted to determine the possible physiological functions and expression intensities of HOXA10, HOXA11, HOXB6 and HOXC6 proteins in the male reproductive system (testes, epididymis and deferens ducts), which are important for the continuity of some specific cat breeds in different age ranges. In the study, a total of 18 testicular tissues were used, divided into two groups: less than 6 months (immature) and more than 1 year (mature). Tissue samples were then subjected to immunohistochemical staining with protein-specific antibodies examined in the study. In the findings obtained in the research; it was observed that HOXA10, HOXA11, HOXB6 and HOXC6 produced different intensities of immunolocalization in the epididymis and ductus deferens layers in the immature and mature testicular cells. In addition, it was found that HOXA10 immunoreaction was also seen in some vascular endothelial cells. As a result, it was concluded that the HOX proteins could contribute to the physiological functions of testes, epididymis and ductus deferens and affect male fertility.

The expressions of some metabolic hormones (leptin, ghrelin and obestatin) in the tissues of sheep tongue

In this study, we aimed to observe the localization and expression of peptide hormones-leptin, ghrelin and obestatin-in the sheep tongue by immunohistochemistry. For that purpose, tongues of ten adult sheep were used. Leptin expression of moderate intensity was observed in the basal and parabasal epithelial cells of the luminal epithelium, and leptin was strongly expressed in the taste buds of the circumvallate and fungiform papillae and in von Ebner's glands. Ghrelin was primarily expressed in some of the skeletal muscle cells and the smooth muscle cells of the middle layer of blood vessels. A strong expression was observed in the epithelial cells lining the base of the groove surrounding the circumvallate papillae. Obestatin expression was particularly strong in the epithelial cells of the salivary ducts. It was also stronger in the von Ebner's glands than in the seromucous glands. Leptin, ghrelin and obestatin were shown to be produced at varying levels in different cell types, including epithelial, stromal and skeletal muscle cells, as well as in ganglion neurons, neural plexuses and blood vessels in the sheep tongue. Cellular localization and expression of these peptide hormones have not been investigated in many species including sheep.

Distribution of CD68-, CD8-, MHCI- and MHCII-positive cells in the bull and ram testis and epididymis

The mammalian testis possesses a special immunological environment because of its properties of remarkable immune privilege and effective local innate immunity. The testicular immune privilege protects immunogenic germ cells from systemic immune attack, and local innate immunity is important in preventing testicular microbial infections. Thus, this study aimed to immunohistochemically demonstrate the distribution and localization of CD68-, CD8-, MHCI- and MHCII-positive immune cells in the testes and epididymes. Negative immunoreactivity was detected in the seminiferous tubule epithelium and peritubular myoid cells of the testes upon staining in CD68, CD8 and MHC Class I. Positive CD68 immunoreaction was determined in the Sertoli cells and some Leydig cells. The detection of positive cells for CD8 clearly indicated the presence of lymphocytes. Furthermore, the staining with MHCI intensity was ascertained to vary from weak to moderate in the Sertoli and Leydig cells and connective tissue cells. MHCII-positive immunoreactivity was determined in myoid cells and Leydig cells in the interstitial area. The epithelium of the epididymis showed positive staining for CD68 and CD8, but the stroma displayed a rather weak staining. In the ram epididymis, neither intraepithelial nor interstitial positive reaction was observed for MHCI. In the epididymis, the basal cells displayed a stronger staining for MHCII. In conclusion, these cells not only contribute to local immunity through their direct effects on the quality of fertility in males, but also contribute either directly or indirectly to immune privilege by minimizing the development of both autoimmune reactions and potentially harmful risks.

Functional characteristics of the growth factor receptor family and some ligands in the oropharyngeal cavity of the Chukar partridge (Alectoris chukar)

1. The aim of the present study is to describe, immunohistochemically, the expression and cell type localisation of growth factor receptors and some of their ligands in the oropharyngeal organs of the Chukar partridge. 2. The tissue samples from 10 healthy adult partridges were dissected under ether anaesthesia and then embedded in paraffin following routine histological procedures. The immunoreaction for receptors and ligands of the epidermal growth factor receptor (EGFR)/ligand system was localised in the cell membrane, nucleus and cytoplasm of the luminal and glandular epithelial cells, stromal and striated muscle cells, and vascular endothelial and smooth muscle cells. 3. Variations were observed in the avian oropharyngeal organs. The immunostaining for the erbB1/HER1 (human epidermal growth factor receptor 1) and the EGF (epidermal growth factor) and AREG (Amphiregulin) ligands in the luminal epithelial cells was higher than in the glandular epithelial, stromal and striated muscle cells. However, the immunostaining for erbB3/HER3 (human epidermal growth factor receptor 3) and erbB4/HER4 (human epidermal growth factor receptor 4) were similar in the luminal epithelium, stromal and striated muscle cells. 4. Growth factor receptors and some of their ligands were localised in different cell types in the oropharyngeal organs. We suggest that erbB/HERs (human epidermal growth factor receptors) and their ligands play an important role in proliferation, differentiation, growth, survival and migration of the cells.

Immunohistochemical localization of epidermal growth factor system in the lung of the Japanese quail (Coturnix coturnix japonica) during the post-hatching period

The purpose of this study is to determine the possible changes in the localization of the four Epidermal Growth Factor Receptors and three ligands in quail lungs from the first day of hatching until the 125th after hatching using immunohistochemical methods. Immunohistochemical results demonstrated that four EGFRs and their ligands are chiefly located in the cytoplasm of cells. Additionally, ErbB4, AREG, and NRG1 are localized to the nucleus and nucleolus, but EGF is present in the nucleolus. ErbB2 was also found in the cell membrane. In the epithelium of secondary bronchi, the goblet cells only exhibited ErbB1 and ErbB2, whereas the basal and ciliated cells exhibited EGFRs and ligands immunoreactivity. The atrial granular cells displayed moderate levels of ErbB1-ErbB3 and EGF and strong levels of ErbB4, AREG, and NRG1 immunoreactivity. While the squamous atrial cells and squamous respiratory cells of air capillaries and endothelial cells of blood capillaries exhibited moderate to strong ErbB2, ErbB4, AREG, and NRG1 immunoreactivity, they had negative or weak ErbB1, ErbB3, and EGF immunoreactivity. The expression levels of ErbB2-ErbB4, EGF, AREG, and NRG1 were also detected in fibroblasts. Although ErbB2 was highly expressed in the bronchial and vascular smooth muscle cells, weak expression of ErbB1, ErbB3, AREG and EGF and moderate expression of ErbB4 and NRG1 were observed. Macrophages were only negative for ErbB1. In conclusion, these data indicate that the EGFR-system is functionally active at hatching, which supports the hypothesis that the members of EGFR-system play several cell-specific roles in quail lung growth after hatching.

The expression of vascular endothelial growth factor and its receptors (flt1/fms, flk1/KDR, flt4) and vascular endothelial growth inhibitor in the bovine uterus during the sexual cycle and their correlation with serum sex steroids

The present study was conducted to demonstrate of the immunohistochemical localization of vascular endothelial growth factor (VEGF) and its receptors (flt1/fms, flk1/KDR and flt4) as well as vascular endothelial growth inhibitor (VEGI) and to determine the correlation of VEGF and its receptors and VEGI with serum sex steroids (estrogen and progesterone) in the bovine uterus during the sexual cycle. The stage of the estrous cycle in 30 Holstein cattle was assessed based on the gross and histological appearance of the ovaries and uterus and on blood steroid hormone levels. Tissue samples obtained from the uterus were fixed in 10% formaldehyde for routine histological processing. During both follicular and luteal phases, positive cytoplasmic and membrane staining was achieved for VEGF and its receptors (flt1/fms, flk1/KDR and flt4) as well as VEGI in the luminal and glandular epithelial cells, the connective tissue and smooth muscle cells, and the vascular endothelial cells and smooth muscle cells in the uterus. The intensity, proportional and total scores determined for VEGF and its receptors (flt1/fms and flt4) as well as VEGI were greater in the luminal and glandular epithelial cells compared to the connective tissue and smooth muscle cells (P < 0.05). Furthermore, the number and intensity of the flk1/KDR positive cells were greater among the connective tissue cells compared to the luminal and glandular epithelial cells (P < 0.05). As a result, it was determined that the expression of VEGF and its receptors as well as VEGI in the bovine uterus during the follicular and luteal phases varied with different cell types. This suggests that depending on the stage of the sexual cycle, these factors may mediate the establishment of an appropriate environment for the nutritional supply and implantation of the embryo primarily due to the stimulation of angiogenesis but also through the increase in the secretory activity of the epithelial cells in the uterus. Furthermore, this indicates that ovarian steroid hormones play a significant role in regulating the expression of VEGF and its receptors as well as VEGI.

Expression of the erbB/HER receptor family in the bovine uterus during the sexual cycle and the relation of this family to serum sex steroids

Our study was designed to investigate immunohistochemically the expression of the receptors of the erbB/HER family (erbB1/HER1, erbB2/HER2, erbB3/HER3, erbB4/HER4) in the bovine uterus during the follicular and luteal phases of the sexual cycle, and the relation to ovarian sex steroids. The stage of the estrous cycle in 30 Holstein bovine was assessed based on the gross and histological appearance of the ovaries and uterus, and on blood steroid hormone levels. Tissue samples taken from the uterus were fixed in 10% formaldehyde for routine histological processing. Positive membrane and cytoplasmic staining of varying intensity were determined in the uterus during the follicular and luteal phases of the sexual cycle for erbB/HER receptors in luminal and glandular epithelial cells, connective tissue, smooth muscle and vascular endothelial and smooth muscle cells. We demonstrated that the apical and basal membranes of luminal epithelial cells and the apical membrane of glandular epithelial cells reacted with erbB1/HER1 and erbB2/HER2 during both the follicular and luteal phases. The reaction for erbB3/HER3 and erbB4/HER4 was stronger in the cytoplasm of luminal and glandular epithelial cells, but was heterogeneous. During both the follicular and luteal phases, the percentage and staining intensity of luminal and superficial glandular epithelial cells reacting positively with the receptors erbB1/HER1, erbB2/HER2, erbB3/HER3 and erbB4/HER4 were greater than those of deep glandular epithelial and connective tissue cells (p < 0.05). We demonstrated that the expression of the erbB/HER receptor family varied with different cell types in the bovine uterus during the follicular and luteal phases.