Immunohistochemical and ultrastructural characteristics of interstitial cells of Cajal in the rabbit duodenum. Presence of a single cilium

Telocytes in the Female Reproductive System: Up-to-Date Knowledge, Challenges and Possible Clinical Applications

From their initial description in 2005 to this day, telocytes (TCs) have been described in the ovary, uterine tubes, uterus, vagina, mammary gland, and placenta. Their morphological features, immunophenotype, physiological functions, and roles in disease have been thoroughly documented in both animal models and human subjects. TCs, with their extremely long cytoplasmic processes called telopodes, play a pivotal role in the morphological and functional interconnection of all the components of the interstitial compartment, but also with constituents of the parenchyma. Although there is no specific immunohistochemical marker for their identification, the most cited are CD 117, CD 34, platelet-derived growth factor receptor (PDGFR), vimentin, and specific markers typical for the female reproductive system (FRS)-estrogen and progesterone receptors (ER and PR). This immunophenotype provides important clues to their physiological roles. Their main functions include the regulation of hormone-dependent processes, intercellular signaling, immune surveillance, microenvironmental maintenance, and the nursing of stem cells. In a situation where TCs are functionally or morphologically decimated, many disease entities may develop, including premature ovarian failure, endometriosis, ectopic pregnancy, infertility, preeclampsia, or even breast cancer. The common denominator of many of these conditions is that their etiopathogenesis is either partially known or completely obscure. Even though the exact role of TCs in these conditions is yet to be revealed, multiple lines of research indicate that their future clinical application may enrich diagnostic-therapeutic strategies of countless conditions. TCs are also heavily debated in terms of their possible use in regenerative medicine and tissue engineering. Some of the concepts related to TC research are strongly substantiated by experimental data, while others are highly speculative. Only future research endeavors will clearly distinguish dead-end lines of research from genuine contributions to the field.

The type 3 adenylyl cyclase is crucial for intestinal mucosal neural network in the gut lamina propria

BACKGROUND

The type 3 adenylyl cyclase (AC3) enzyme is involved in the synthesis of cyclic adenosine monophosphate (cAMP). It is primarily expressed in the central nervous system (CNS) and plays a crucial role in neurogenesis and neural dendritic arborization. However, the AC3's functional role in the gastrointestinal tract remains ambiguous.

METHODS

AC3 expression in enteric tissue of AC3^+/+ mice was investigated using immunohistochemistry and RT-PCR. AC3 knock-out mice (AC3^-/- ) were used to examine the effect of AC3 on the enteric nervous system (ENS) function and the number of cilia and apoptotic cells. Additionally, total gastrointestinal transit time and colonic motility were compared between the AC3^-/- and AC3^+/+ groups of mice.

KEY RESULTS

AC3 was predominately expressed in the myenteric plexus of the large intestine. Colonic-bead expulsion analysis showed accelerated propulsion in the large intestine of the AC3^-/- mice. The AC3^-/- mice demonstrated reduced nerve fibers and enteric glial cells count in colonic mucosa compared to the AC3^+/+ mice. Furthermore, AC3^-/- mice exhibited increased cellular apoptosis and reduced ARL13B⁺ cilium cells in the colonic lamina propria compared to the AC3^+/+ mice.

CONCLUSIONS

In AC3^-/- mice, innervation of the lamina propria in the colonic mucosa was reduced and colonic propulsion was accelerated. AC3 is crucial for the development and function of the adult neural network of ENS. AC3 deficiency caused atrophy in the colonic mucosal neural network of mice.

Nestin and CD34 expression in colorectal cancer predicts improved overall survival

BACKGROUND

Nestin, a class VI intermediate filament protein of the cytoskeleton, and CD34, a transmembrane phosphoglycoprotein, are markers of progenitor cells. This study aimed to evaluate their expression and clinical significance in colorectal cancer.

METHODS

A clinically annotated tissue microarray, including 599 patients with colorectal cancer, was analyzed by immunohistochemistry. Furthermore, nestin and CD34 correlations with HIF-1a and a panel of cytokines and chemokines were assessed using quantitative reverse transcription PCR and The Cancer Genome Atlas dataset.

RESULTS

Expression of nestin and CD34 was observed only in the tumor stroma. Patients displaying high expression of nestin and CD34 demonstrated higher rates of T1 and T2 tumors (p = .020), lower vascular invasion (p < .001) and improved 5-year overall survival (65%; 95% CI = 55-73 vs 45%; 95% CI = 37-53) after adjusting for clinicopathological characteristics (HR: 0.67; 95% CI = 0.46-0.96). A moderate to strong correlation (r = 0.37-0.78, p < .03) of nestin and CD34 was demonstrated for the following markers; HIF-1α, CD4, CD8, FOXP3, IRF1, GATA3, CCL2, CCL3, CXCL12 and CCL21.

CONCLUSIONS

Combined expression of nestin and CD34 expression is associated with better overall survival possibly by modulating a favorable immune response.

Ultrastructural evidence for telocytes in equine tendon

The three-dimensional ultrastructure of the tendon is complex. Two main cell types are classically supported: elongated tenocytes and ovoid tenoblasts. The existence of resident stem/progenitor cells in human and equine tendons has been demonstrated, but their location and relationship to tenoblasts and tenocytes remain unclear. Hence, in this work, we carried out an ultrastructural study of the equine superficial digital flexor tendon. Although the fine structure of tendons has been previously studied using electron microscopy, the presence of telocytes, a specific type of interstitial cell, has not been described thus far. We show the presence of telocytes in the equine inter-fascicular tendon matrix near blood vessels. These telocytes have characteristic telopodes, which are composed of alternating dilated portions (podoms) and thin segments (podomers). Additionally, we demonstrate the presence of the primary cilium in telocytes and its ability to release exosomes. The location of telocytes is similar to that of tendon stem cells. The telocyte-blood vessel proximity, the presence of primary immotile cilia and the release of exosomes could have special significance for tendon homeostasis.

Mast Cell Tumors and Histiocytomas in Domestic Goats and Diagnostic Utility of CD117/c-Kit and Iba1 Immunohistochemistry

Cutaneous round cell tumors in goats present a diagnostic challenge. In this article, we provide a description of caprine cutaneous mast cell tumors (MCT) and histiocytomas, and report on the validation of anti-human antibodies to CD117/KIT and Iba1 by immunohistochemistry on a range of caprine tissues. Cells immunolabeled for CD117/KIT included resident mast cells in normal lung and skin, interstitial cells of Cajal (intestine), and neuronal cell bodies (brain). Cells immunolabeled for Iba1 included resident macrophages in many tissues including normal lung, dendritic cells (hemolymphatic tissues), Kupffer cells, and microglia. Of 5 cutaneous MCT, only one had metachromasia of cytoplasmic granules; however, neoplastic cells of all 5 MCT had positive immunolabeling for CD117/KIT. The CD117/KIT immunolabeling pattern was predominately focal paranuclear in 3 cases, and cytoplasmic or membranous in 1 case each. Two histiocytomas were identified and had strong positive immunolabeling for Iba1 but not CD117/KIT. All 7 cutaneous round cell tumors described herein occurred in goats less than 4 years of age; the 2 cutaneous histiocytomas were in goats less than 14 months of age. Neither of the cutaneous histiocytomas recurred within 24 months of surgical removal.

Immunohistochemical and ultrastructural evidence for telocytes in the different physiological stages of the female rat mammary gland

INTRODUCTION

Telocytes (TCs) are recently described to integrate a variety of different cells.

AIM OF THE WORK

The aim was to investigate the presence of TCs in the rat mammary gland at its different physiological stages.

MATERIAL AND METHODS

Twenty four adult female albino rats were classified into 4 groups: resting, mid-pregnancy, lactating, and involution groups. Inguinal mammary glands were processed for immunohistochemical and transmission electron microscopic (TEM) examination.

RESULTS

TCs were immune-positive for c-kit and CD34 and showed significant differences in the different studied groups indicating variable roles at the different stages. TEM results characterized TCs by its shape and the long slender and moniliform telopodes linking the cells into stromal networks. The extracellular exosomes, homo-cellular synapsis and hetero-cellular synapsis were observed.

CONCLUSION

Our study provides evidence for the presence of TCs in all stages of the gland; not only in the resting stage as proved by other studies, but with immune-labeling differences suggesting different structural and physiological roles of TCs according to the stage requirements. These functions might via controlling the proliferation during pregnancy and lactation and the involution of the gland after weaning. Thus, more future functional studies of TCs will be important to help understanding the mechanism by which TCs contribute to tissue homeostasis concerning the role of the stromal/epithelial interactions in mammary gland biology and pathology including breast cancer which would be revolutionary for future therapeutic applications.

Concise review: evidence for CD34 as a common marker for diverse progenitors

CD34 is a transmembrane phosphoglycoprotein, first identified on hematopoietic stem and progenitor cells. Clinically, it is associated with the selection and enrichment of hematopoietic stem cells for bone marrow transplants. Due to these historical and clinical associations, CD34 expression is almost ubiquitously related to hematopoietic cells, and it is a common misconception that CD34-positive (CD34⁺) cells in nonhematopoietic samples represent hematopoietic contamination. The prevailing school of thought states that multipotent mesenchymal stromal cells (MSC) do not express CD34. However, strong evidence demonstrates CD34 is expressed not only by MSC but by a multitude of other nonhematopoietic cell types including muscle satellite cells, corneal keratocytes, interstitial cells, epithelial progenitors, and vascular endothelial progenitors. In many cases, the CD34⁺ cells represent a small proportion of the total cell population and also indicate a distinct subset of cells with enhanced progenitor activity. Herein, we explore common traits between cells that express CD34, including associated markers, morphology and differentiation potential. We endeavor to highlight key similarities between CD34⁺ cells, with a focus on progenitor activity. A common function of CD34 has yet to be elucidated, but by analyzing and understanding links between CD34⁺ cells, we hope to be able to offer an insight into the overlapping properties of cells that express CD34. Stem Cells2014;32:1380–1389

Primary cilia in gastric gastrointestinal stromal tumours (GISTs): an ultrastructural study

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal (non-epithelial) neoplasms of the human gastrointestinal (GI) tract. They are thought to derive from interstitial cells of Cajal (ICCs) or an ICC progenitor based on immunophenotypical and ultrastructural similarities. Because ICCs show primary cilium, our hypothesis is based on the possibility that some of these neoplastic cells could also present it. To determine this, an exhaustive ultrastructural study has been developed on four gastric GISTs. Previous studies had demonstrated considerable variability in tumour cells with two dominating phenotypes, spindly and epithelioid. In addition to these two types, we have found another cell type reminiscent of adult ICCs with a voluminous nucleus surrounded by narrow perinuclear cytoplasm with long slender cytoplasmic processes. We have also noted the presence of small undifferentiated cells. In this study, we report for the first time the presence of primary cilia (PCs) in spindle and epithelioid tumour cells, an ultrastructural feature we consider of special interest that has hitherto been ignored in the literature dealing with the ultrastructure of GISTs. We also point out the frequent occurrence of multivesicular bodies (MVBs). The ultrastructural findings described in gastric GISTs in this study appear to be relevant considering the critical roles played by PCs and MVBs recently demonstrated in tumourigenic processes.

Enteric neurons show a primary cilium

The primary cilium is a non-motile cilium whose structure is 9+0. It is involved in co-ordinating cellular signal transduction pathways, developmental processes and tissue homeostasis. Defects in the structure or function of the primary cilium underlie numerous human diseases, collectively termed ciliopathies. The presence of single cilia in the central nervous system (CNS) is well documented, including some choroid plexus cells, neural stem cells, neurons and astrocytes, but the presence of primary cilia in differentiated neurons of the enteric nervous system (ENS) has not yet been described in mammals to the best of our knowledge. The enteric nervous system closely resembles the central nervous system. In fact, the ultrastructure of the ENS is more similar to the CNS ultrastructure than to the rest of the peripheral nervous system. This research work describes for the first time the ultrastructural characteristics of the single cilium in neurons of rat duodenum myenteric plexus, and reviews the cilium function in the CNS to propose the possible role of cilia in the ENS cells.

Cellular expression profile for interstitial cells of cajal in bladder - a cell often misidentified as myocyte or myofibroblast

BACKGROUND

Interstitial cells of Cajal (ICC) have been identified in urinary bladder of several species, but their presence in mice remains uncertain. Meanwhile, dozens of reports indicate that dysregulation of connexin 43 plays an important role in bladder overactivity, but its localization has not been clearly defined, with reports of expression in either the smooth muscle or in myofibroblasts. We recently identified a population of ectonucleoside triphosphate diphosphohydrolase 2 (NTPDase2) positive cells that resemble ICC and are distinct from smooth muscle, fibroblasts, myofibroblasts and neurons. Thus we sought to define more clearly the molecular signature of ICC and in doing so resolve some of these uncertainties.

PRINCIPLE FINDINGS

Immunofluorescent localization revealed that NTPDase2-positive cells lie closely adjacent to smooth muscle but are separate from them. NTPDase2 positive cells exhibited co-localization with the widely accepted ICC marker - c-kit. They were further shown to co-localize with other ICC markers CD34 and Ano1, but not with mast cell marker tryptase. Significantly, they show convincing co-localization with connexin 43, which was not present in smooth muscle. The identity of these cells as ICC was further confirmed by the presence of three mesenchymal markers - vimentin, desmin, and PDGFβ receptor, which indicates their mesenchymal origin. Finally, we observed for the first time, the presence of merlin/neurofibromin 2 in ICC. Normally considered a neuronal protein, the presence of merlin suggests ICC in bladder may have a role in neurotransmission.

CONCLUSIONS

NTPDase2 positive cells in mice bladder are ICC, which can be defined by the presence of c-Kit, CD34, Ano1, NTPDase2, connexin 43, vimentin, desmin, PDGFβ receptor and merlin/NF2. These data establish a definitive molecular expression profile, which can be used to assist in explorations of their functional roles, and the presence of NTPDase2 suggests that purinergic signaling plays a role in regulation of ICC function.

Ultrastructural identification of interstitial cells of Cajal in hen oviduct

The interstitial cells of Cajal (ICC) are widely believed to be neuroeffector cells of smooth muscle activity in all tubular organs, including the oviduct. The avian oviduct involves the secretion, sheathing, and transportation of a large-sized egg, but there is no information available on ICC in this special organ. We have demonstrated the presence of ICC in different segments throughout the oviduct in the laying hen and provided details on their ultrastructure by transmission electron microscopy technique, for the first time. The observed ICC appeared bipolar and multipolar cells of different shapes, with varying nuclear morphologies, a thin rim of electron-dense cytoplasm, and an infrequent basal lamina. They showed moniliform primary processes with one or 2 secondary or terminal processes. We found ICC near smooth muscle cells, nerve fibers, and the epithelia, where they make specialized contacts in the form of close membrane associations or gap-like junctions and peg-and-socket-like junctions. Intricate labyrinthine-type networking contacts were also present in ICC processes. Moreover, we report for the first time, that ICC in avian oviduct make interdigitating contacts with the epithelium. Cytoplasmic organelles identified in ICC include numerous well-developed mitochondria, abundant rough endoplasmic reticulum, and dispersed intermediate filaments. Many caveolae and vesicles were also present. Golgi bodies and centrioles were rare. Fibroblasts, on the other hand, were distinct cells with larger cytoplasmic area, more rough endoplasmic reticulum, and less mitochondrial content. No basal lamina, intermediate filaments, or caveolae were present in fibroblasts. Their processes were shorter and showed no contacts with smooth muscle cells or nerves. We conclude that these ICC might also have a key role in the regulatory mechanisms of motility and transportation in the hen oviduct, as already proved in mammalian oviduct. Such role of ICC might also be responsible for the function of the muscular infundibulum, where the fertilization takes place, and that moves to surround the released ovum, failure of which results in the internal laying.

Two patterns of development of interstitial cells of Cajal in the human duodenum

At the end of the embryonic period of human development, c-kit immunoreactive (c-kit IR) cells identifiable as interstitial cells of Cajal (ICC) are present in the oesophagus and stomach wall. In the small and large bowel, c-kit-IR cells appear later (in the small bowel at 9 weeks, and in the colon at 10-12 weeks), also in the MP region. The object of this study was to determine the timing of appearance and distribution of c-kit IR cells in the human embryonic and foetal duodenum. I used immunohistochemistry to examine the embryonic and foetal duodenum for cells expressing CD117 (Kit), expressed by mature ICC and ICC progenitor cells and CD34 to identify presumed ICC progenitors. Enteric plexuses were examined by way of antineuron-specific enolase and the differentiation of smooth muscle cells was studied using antidesmin antibodies. At the end of the embryonic period of development, c-kit IR cells were solely present in the proximal duodenum in the form of a wide belt of densely packed cells around the inception of the myenteric plexus (MP) ganglia. In the distal duodenum, c-kit IR cells emerged at the beginning of the foetal period in the form of thin rows of pleomorphic cells at the level of the MP. From the beginning of the fourth month, the differences in the distribution of ICC in the different portions of the duodenum were established, and this relationship was still present in later developmental stages. In fact, in the proximal duodenum, ICC of the MP (ICC-MP), ICC of the circular muscle (ICC-CM) and ICC of the septa (ICC-SEP) were present, and in the distal duodenum ICC-MP and ICC-SEP only. In conclusion, in the humans there is a difference in the timing and patterns of development of ICC in the proximal duodenum compared to the distal duodenum.

The primary cilium of telocytes in the vasculature: electron microscope imaging

Blood vessels are highly organized and complex structure, which are far more than simple tubes conducting the blood to almost any tissue of the body. The fine structure of the wall of blood vessels has been studied previously using the electron microscope, but the presence the telocytes associated with vasculature, a specific new cellular entity, has not been studied in depth. Interestingly, telocytes have been recently found in the epicardium, myocardium, endocardium, human term placenta, duodenal lamina propria and pleura. We show the presence of telocytes located on the extracellular matrix of blood vessels (arterioles, venules and capillaries) by immunohistochemistry and transmission electron microscopy. Also, we demonstrated the first evidence of a primary cilium in telocytes. Several functions have been proposed for these cells. Here, the telocyte-blood vessels cell proximity, the relationship between telocytes, exosomes and nervous trunks may have a special significance.

Myometrial interstitial cells and the coordination of myometrial contractility

A strict regulation of contractility in the uterus and fallopian tube is essential for various reproductive functions. The uterus contributes, through either increased contractility or periods of relative quiescence, to: (i) expulsion of menstrual debris, (ii) sperm transport, (iii) adequate embryo placement during implantation, (iv) enlarging its capacity during pregnancy and (v) parturition. The dominant cell population of the uterine wall consists of smooth muscle cells that contain the contractile apparatus responsible for the generation of contractile force. Recent interest has focused on a new population of cells located throughout the myometrium on the borders of smooth muscle bundles. These cells are similar to interstitial cells of Cajal (ICC) in the gut that are responsible for the generation of electrical slow waves that control peristalsis. A precise role for myometrial Cajal-like interstitial cells (m-ICLC) has not been identified. m-ICLC express the c-kit receptor, involved in creating and maintaining the ICC phenotype in the gastrointestinal tract. However, both acute and prolonged inhibition of this receptor with the c-kit antagonist imatinib mesylate does not appear to affect the spontaneous contractility of myometrium. Calcium imaging of live tissue slices suggests that contractile signalling starts on the borders of smooth muscle bundles where m-ICLC are located and recently the possible role of extracellular ATP signalling from m-ICLC has been studied. This manuscript reviews the evidence regarding tissue-level signalling in the myometrium with a particular emphasis on the anatomical and possible functional aspects of m-ICLC as new elements of the contractile mechanisms in the uterus.

A distinct type of cell in myocardium: interstitial Cajal-like cells (ICLCs)

The existence of a novel type of interstitial cells in the heart, interstitial Cajal-like cells (ICLCs), had been described for the first time in 2005. Their identification was mainly based on ultrastructural criteria: very long (tens up to hundreds of micrometres) and moniliform prolongations, which are extremely thin (less than 0.2 μm), below the resolving power of light microscopy. Myocardial ICLCs were also identified by methylene-blue vital staining, silver impregnation, and immunoreactivity for CD 34, vimentin, CD117/c-kit, etc. Although a series of studies provided evidence for the existence of ICLCs in human atria and rat ventricles, further investigations in other laboratories, using additional techniques, are required to substantiate the consistency of these findings. Here we provide further evidence for the existence of ICLCs in human and mammalian hearts (by transmission and scanning electron microscopy, as well as confocal laser scanning microscopy). Noteworthy, we confirm that ICLCs communicate with neighbouring cells via shedding (micro)vesicles. Although these so-called ICLCs represent a distinct type of cells, different from classical interstitial cells of Cajal, or fibroblasts, their role(s) in myocardium remain(s) to be established. Several hypotheses are proposed: (i) adult stromal (mesenchymal) stem cells, which might participate in cardiac repair/remodelling; (ii) intercellular signalling (e.g. via shedding microvesicles); (iii) chemo-mechanical transducers and (iv) players in pacemaking and/or arrhytmogenesis, and so on.

Control of gallbladder contractions by cholecystokinin through cholecystokinin-A receptors on gallbladder interstitial cells of cajal

AIM: To identify the cholecystokinin (CCK)-A receptors (CCK-AR) on the guniea pig gallbladder interstitial cells of cajal (ICC) and to study CCK-8 induced gallbladder muscle strip contractions through the CCK-AR.

METHODS: The existence of CCK-AR was examined by immunohistofluorescence on sectioned tissue and cultured cells. In vitro contractile response of guinea pig gallbladder muscle strips and the strips with ICC removed were also studied with CCK-8 receptors added.

RESULTS: In tissue sections, intensely CCKAR-immunoreactive interstitial cells were found mainly in the muscular layers. In cultured cell sections, distinctive double staining of C-kit and CCK-AR ICCs were found. When we removed the ICC of the gallbladder, CCK-8 induced muscle strip contraction dose response curve significantly shifted to the right.

CONCLUSION: We proved that both the existence of CCK-AR on the guinea pig gallbladder ICC and CCK evoked contraction are mediated through direct action on CCK-AR on the gallbladder ICC.

Myocardial interstitial Cajal-like cells (ICLC) and their nanostructural relationships with intercalated discs: shed vesicles as intermediates

Intercalated discs (ID) are complex junctional units that connect cardiac myocytes mechanically and electrochemically. However, there is limited information concerning the cardiomyocyte interaction with interstitial non-muscle cells. Our previous studies showed that myocardial interstitial Cajal-like cells (ICLC) are located in between cardiomyocytes, blood capillaries and nerve fibres. Typically, ICLC have several very long, moniliform, cytoplasmic processes which establish closed contacts with nerve fibres, as well as each other. We report here ultrastructural evidence concerning the relationships of ICLC processes with ID. The ICLC cytoplasmic prolongations (tens micrometers length) preferentially pass by or stop nearby the ID. Transmission electron microscopy emphasized three distinct connecting features between the tips of ICLC extensions and myocytes at the ‘mouth’ of ID: free or budding shed vesicles, exocytotic multi-vesicular bodies and direct contacts. In the last case, electron-dense repetitive nanostructures (‘pillars’) (35–40 nm high and 100–150 nm wide, similar to adhesion molecules) fasten the ICLC to the myocytes. All these features suggest a juxtacrine and/or paracrine intercellular mutual modulation of ICLC and cardiomyocytes in the microenvironment of ID, possibly monitoring the cardiac functions, particularly the electrical activity.

Interstitial Cajal-like cells in rat mesentery: an ultrastructural and immunohistochemical approach

Interstitial Cajal-like Cells (ICLC) were recently recognized in a plethora of non-digestive organs. Here, we describe a cell type of rat mesentery sharing ultrastructural and immunohistochemical features with ICLC. Mesenteric ICLC were demonstrated by transmission electron microscopy (TEM) and further tested by light microscope immunohistochemistry. The cell described here fulfils the TEM diagnostic criteria accepted for ICLC: location in the connective interstitium; close vicinity to nerves, capillaries and other interstitial cells; characteristic long, moniliform cell processes; specialized cell-to-cell junctions; caveolae; mitochondria at 5–10% of cytoplasmic volume; rough endoplasmic reticulum at about 1–2%; intermediate and thin filaments, microtubules; undetectable thick filaments. The processes of this mesenteric ICLC were particularly long, with a mean length of 24.91 μm (10.27–50.83 μm), and a convolution index of 2.32 (1.37–3.63) was calculated in order to measure their potential length. Mean distances versus main target cells of ICLC–nerve bundles, vessels, adipocytes and macrophages–were 110.69, 115.80, 205.07 and 34.65 nm, respectively. We also tested the expression of CD117/c-kit, CD34, vimentin, α-smooth muscle actin, nestin, NK-1, tryptase and chymase and the antigenic profile of the mesenteric ICLC was comparable if not identical with that recently observed in ICLC from other extra-digestive tissues. Due to the peculiar aspect of the mesenteric ICLC processes it can be hypothesized that these cells form a three-dimensional network within the mesentery that is at the same time resistant and deformable following stretches consequent to intestine movements, mainly avoiding blood vessels closure or controlling blood vessels rheology. It remains, however, to be established if and how such cells are connected with the archetypal enteric ICC.