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.

Telocytes (TCs) are a vital constituent of interstitial tissue. They contribute to regulating cell function in heterotypic connections via direct contact or paracrine singling. Few studies mentioned intraepithelial TCs; however, they have been identified with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In this study, we investigated the intraepithelial and interstitial TCs using immunohistochemistry (IHC) and TEM. TCs can be identified by their distinctive telopodes (TPs), which consist of podoms and podomere, using TEM and immunohistochemical staining with CD34, CD117, and VEGF antibodies. Intraepithelial TCs established heterocontact with the lamellar capillary and interstitial TCs connected with the blood vessel in lamina propria. Intraepithelial TCs established direct contact with epithelial cells, which formed the lymph space while interstitial TCs connected with the secondary vascular vessels. The study provides evidence for TCs' heterocontact with lamellar blood capillaries, the blood vessels, chloride cells, and immune cells, such as rodlet cells and lymphocytes. In conclusion, TCs have a role in regulating respiratory activities, maintaining osmotic pressure, modulating the immune response, and conducting immunosurveillance.

Lactoferrin is a multifunctional protein that has roles in iron metabolism, cell generation and differentiation, and antibacterial, antiviral, and antiparasitic activity. The
study aim was to evaluate the effect of dietary lactoferrin powder on the innate
immune response and disease resistance of silver carp (Hypophthalmichthys molitrix)
infected with Vibrio vulnificus. The study also investigates immune cells in different
organs including gills, intestine, spleen, liver, and pancreas using light, scan electron
microcopy. Two diet regimes, a basic diet and a 600-mg/kg bovine lactoferrinsupplemented diet were used. The fish were fed for 30 successive days. We included
270 apparently healthy silver carp (H. Molitrix) with an average body weight of
10 ± 2 g/fish. Addition of lactoferrin to the diet led to an increase in the activity of
non-specific immune parameters; lymphocytes, and in the monocytes percentage,
and in total protein, serum globulin, and albumin, with a corresponding increase in
phagocytic activities and indices. The histological analysis revealed increase immune
cells such as lymphocytes in intestine, rodlet cells in liver, gills, and pancreas, and the
macrophages in liver, pancreas as well as spleen. The lactoferrin-supplemented diet
significantly increased survival and disease resistance following V. vulnificus challenge, which seemed to correspond to an enhancement of non-specific immune functions in H. molitrix