Morphological changes in intraepithelial and stromal telocytes in Cyprinus carpio in response to salinity stress

Telocytes establish connections and communicate with various types of cells and structures. Few experimental studies have been performed on telocytes. In this study, we investigated the effect of salinity stress on telocytes in relation to osmoregulatory, immune, and stem cells. After exposing the common carp to 0.2 (control), 6, 10, or 14 ppt salinity, we extracted and fixed gill samples in glutaraldehyde, processed and embedded the samples in resin, and prepared semi-thin and ultrathin sections. Two types of telocytes were identified: intraepithelial and stromal telocytes. Intraepithelial telocytes were found to form part of the cellular lining of the lymphatic space and shed secretory vesicles into this space. Stromal telocytes were observed to shed their secretory vesicles into the secondary circulatory vessels. Both intraepithelial and stromal telocytes were enlarged and exhibited increased secretory activities as salinity increased. They exerted their effects via direct contact and paracrine signaling. The following changes were observed in samples from fish exposed to high salinity levels: chloride cells underwent hypertrophy, and their mitochondria became cigar-shaped; pavement cells were enlarged, and their micro-ridges became thin and elongated; stromal telocytes established contact with stem cells and skeletal myoblasts; skeletal muscle cells underwent hypertrophy; and macrophages and rodlet cells increased in number. In conclusion, our findings indicate that intraepithelial and stromal telocytes respond to salinity stress by activating cellular signaling and that they play major roles in osmoregulation, immunity, and regeneration.

Role of Uterine Telocytes During Pregnancy

Endometrial remolding and angiogenesis are critical events that occur during pregnancy in order to establish uteroplacental vascular communication. This study investigated the role of uterine telocytes (TCs) in pregnancy. We analyzed the distribution of TCs and morphological changes in the endometrium of the gravid rabbit uterus at different stages of pregnancy: after ovulation, pre-implantation (day 7), post-implantation (days 8 and 9), and mid-pregnancy (day 14) and late (days 21–28) pregnancy. TCs gradually increased with the progression of pregnancy. They had distinctive telopodes (TPs) and podoms, with intranucleolar chromatin. The TCs established contact with decidual cells, growing a glandular epithelium, blood vessels, and immune cells, such as lymphocytes, neutrophils, and macrophages. The TCs underwent morphological changes at the post-implantation phase. They acquired thick and voluminous TPs, formed an extensive three-dimensional (3D) labyrinth at mid-pregnancy, and exhibited irregular-shaped nuclei and a dilated rough endoplasmic reticulum at late pregnancy. They also acquired a convoluted contour-formed complex network. Scanning electron microscopy (SEM) showed an extensive 3D network in the endometrium, forming a condensed sheath at late pregnancy. Transmission electron microscopy and SEM detected fenestrated TPs, and TCs were identified by CD34 and vascular endothelial growth factor expression. TCs also expressed matrix metalloproteinase-9 and transforming growth factor beta-1. Results suggested that TCs might play an essential role in maternal placenta formation, especially decidualization, regulation of uterine gland development, and neovascularization of maternal uterine blood vessels.

Endocrine, Stemness, Proliferative, and Proteolytic Properties of Alarm Cells in Ruby-Red-Fin Shark (Rainbow Shark), Epalzeorhynchos frenatum (Teleostei: Cyprinidae)

The current study investigated the morphological, histochemical, and immunohistochemical characteristics of alarm cells and their precursors in ruby-red-fin shark (rainbow shark), Epalzeorhynchos frenatum (Teleostei: Cyprinidae). Precursor alarm cells were shown to be small, cuboidal, pyramidal, or round in shape, with eosinophilic cytoplasm, resting on the basement membrane of the epidermis. The cells later elongated to become columnar in shape. Subsequently, they enlarged and became large oval-shaped cells. They then underwent shrinkage and vacuolation. The superficial alarm cells were collapsed. Alarm cells were found to have an affinity for different histochemical stains, including bromophenol blue, iron hematoxylin, Sudan black, Mallory triple trichrome, Crossman's trichrome, Safranin O, and Weigert's stains, as well as lipase and alkaline phosphatase. Endocrine properties of the alarm cells were identified by silver staining and synaptophysin immunostaining. Alarm cells exhibited stemness activities and had a strong immunoaffinity for CD117. They had a proteolytic function, as identified by lysosome-specific staining with acridine orange and strong immunoaffinity for matrix metalloproteinase (MMP-9). They also exhibited proliferatively, reflected by immunological staining by proliferating cell nuclear antigen. In conclusion, alarm cells are unique epidermal cells with multiple functions. They play immunological, and endocrine, roles. They also retain stemness and proliferative properties.

Effect of Khat (Catha edulis Forsk) extract on testicular maturation in pre-pubertal and pubertal rats: A morphological and biochemical study

The present study aimed at analysing the effect of Khat plant extract on rat testicular development. Thirty-two weaned male albino rats (4 weeks old) were divided into four groups consisting of eight animals each. While control animals received normal saline, rats of groups I, II and III received 100, 200 and 300 mg Khat extract per kg body weight dissolved in distilled water by oral gavage daily for 8 weeks, respectively. Blood samples were collected in separate heparinized tubes by cardiac puncture from each rat and processed for measuring plasma levels of reproductive hormones LH, FSH, testosterone and prolactin. Five-µm sections were stained with haematoxylin and eosin and examined by light microscope. Some sections were immunostained for protamine-1 representing a biomarker for intact sperm differentiation. The present study clearly demonstrated that Khat extract has a pronounced effect on testicular maturation of developing albino rats at both the morphological and functional levels. Khat-treated groups revealed a significantly low serum testosterone level and severe impairment of spermatogenesis when compared with control animals. The current findings also verified, for the first time, that the final stages of sperm maturation (spermiogenesis) were strongly impaired after administration of Khat extract to experimental rats particularly at a higher dose (300 mg/kg body weight). This was proved by the very weak, if any, expression of protamine-1 in the maturing spermatids in Khat-treated rats.

Migratory Activities and Stemness Properties of Rodlet Cells

The current study aimed to characterize different stages of rodlet cells using light microscopy, immunohistochemistry, and transmission electron microscopy. Granular rodlet cells have a distinct granular cytoplasm. Transitional rodlet cells had distinct capsules, and immature granules. Mature rodlet cells were pear-shaped and had elongated granules. Ruptured rodlet cells had a granular cytoplasm. The affinity of rodlet cells for different histochemical techniques was detected. Immunohistochemical analysis of rodlet cells for stem cell markers such as CD117, CD34, proliferation marker, proliferating cell nuclear antigen (PCNA), endopeptidase activity; matrix metalloproteinase-9 (MPP-9) and the angiogenic factor; vascular endothelial growth factor (VEGF) was investigated. All stages of rodlet cells were expressed CD117. However, the ruptured stage was CD117-negative. The granular, transitional, and mature stages had strong CD34 immunoaffinity, while the ruptured rodlet cells were CD34-negative. The most potent immunoreactivity for PCNA was the granular rodlet cells. The transitional cells exhibited less immunoreactivity, while mature rodlet cells had no immunoaffinity for PCNA. All stages of rodlet cells had high enzyme activity as indicated by Acridine orange and exhibited strong MPP-9 immunoaffinity. VEGF is mostly expressed by granular, transitional, and mature rodlet cells. In conclusion, rodlet cells relatively had stemness properties, endopeptidase activity, express a proliferation marker, and angiogenic factors. We suggest a potential role of rodlet cells in immune defense.

Morphological and immunohistochemical phenotype of TCs in the intestinal bulb of Grass carp and their potential role in intestinal immunity

The current study investigated telocytes (TCs) in the intestinal bulb of Grass carp using light microscopy (LM), Transmission electron microscopy (TEM), scanning electron microscopy, and immunohistochemistry (IHC). By LM, TCs were distinguished by the typical morphological features that had a cell body and telopodes using HE, toluidine blue, methylene blue, Marsland silver stain, Grimelius's silver nitrate, Giemsa, PAS, combined AB pH2,5/PAS, Crossmon's and Mallory triple trichrome, Van Gieson stains, Verhoeff's stain, Sudan black, osmic acid, performic acid with methylene blue and bromophenol blue. TCs were identified under the epithelium as an individual cell or formed a TCs sheath. They detected in the lamina propria, between muscle fibers, around the myenteric plexus and fibrous tissue. TCs acquired immunological features of endocrine cells that exhibited high affinity for silver stain, performic acid with methylene blue, Marsland stain, and immunohistochemical staining using chromogranin A. Sub epithelial TCs were closely related to the endocrine cells. TCs and their secretory activities were recognized using acridine orange. TCs were identified by IHC using CD34, CD117, S100-protein, desmin. TCs formed a3D network that established contact with macrophage, mast cells, dendritic cells, lymphocytes, smooth muscle fibers, fibroblast, Schwann cells and nerve fibers. In conclusion, the localization of TCs in relation to different types of immune cells indicated their potential role in the maintenance of intestinal immunity.

Antidiabetic and Antioxidant Impacts of Desert Date (Balanites aegyptiaca) and Parsley (Petroselinum sativum) Aqueous Extracts: Lessons from Experimental Rats

Medicinal plants are effective in controlling plasma glucose level with minimal side effects and are commonly used in developing countries as an alternative therapy for the treatment of type 1 diabetes mellitus. The aim of this study is to evaluate the potential antidiabetic and antioxidant impacts of Balanites aegyptiaca and Petroselinum sativum extracts on streptozotocin-induced diabetic and normal rats. The influences of these extracts on body weight, plasma glucose, insulin, total antioxidant capacity (TAC), malondialdehyde (MDA) levels, and liver-pyruvate kinase (L-PK) levels were assessed. Furthermore, the weight and histomorphological changes of the pancreas were studied in the different experimental groups. The herbal preparations significantly reduced the mean plasma glucose and MDA levels and significantly increased the mean plasma insulin, L-PK, and TAC levels in the treated diabetic groups compared to the diabetic control group. An obvious increase in the weight of the pancreas and the size of the islets of Langerhans and improvement in the histoarchitecture were evident in the treated groups compared to untreated ones. In conclusion, the present study provides a scientific evidence for the traditional use of these extracts as antidiabetic and antioxidant agents in type 1 diabetes mellitus.