Leukocyte Nucleolus and Anisakis pegreffii-When Falling Apart Means Falling in Place.

The view of the nucleolus as a mere ribosomal factory has been recently expanded, highlighting its essential role in immune and stress-related signalling and orchestrating. It has been shown that the nucleolus structure, formed around nucleolus organiser regions (NORs) and attributed Cajal bodies, is prone to disassembly and reassembly correlated to various physiological and pathological stimuli. To evaluate the effect of parasite stimulus on the structure of the leukocyte nucleolus, we exposed rat peripheral blood mononuclear cells (PBMC) to the crude extract of the nematode A. pegreffii (Anisakidae), and compared the observed changes to the effect of control (RPMI-1640 media), immunosuppressive (MPA) and immunostimulant treatment (bacterial lipopolysaccharide (LPS) and viral analogue polyinosinic:polycytidylic acid (poly I:C)) by confocal microscopy. Poly I:C triggered the most accentuated changes such as nucleolar fragmentation and structural unravelling, LPS induced nucleolus thickening reminiscent of cell activation, while MPA induced disassembly of dense fibrillar and granular components. A. pegreffii crude extract triggered nucleolar segregation, expectedly more enhanced in treatment with a higher dose. This is the first evidence that leukocyte nucleoli already undergo structural changes 12 h post-parasitic stimuli, although these are likely to subside after successful cell activation.

Metastasis-associated protein 1 (MTA1) regulates the catecholamine production homeostasis via transcriptional repression of aromatic l-amino acid decarboxylase (Aadc) in the interstitial cells of Cajal of mouse prostate.

Based on the lately identified role for the interstitial cells of Cajal (ICCs) of mouse prostate in catecholamine production, as well as the well-established role for the master coregulator metastasis-associated protein 1 (MTA1) in inflammation, we probed into the functional link between aberrant MTA1 expression and pathogenesis of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) using both a MTA1-/- mouse model of experimental autoimmune prostatitis (EAP) and an in vitro chronic prostatitis model in cultured murine ICCs. EAP-induced MTA1 expression was enriched in ICCs of mouse prostate. EAP resulted in a higher increase in the pelvic pain response in MTA1-/- mice compared to WT mice. Consistently, the ICCs from MTA1-/- mice produced higher levels of catecholamines upon induction of in vitro chronic prostatitis. Mechanistically, MTA1 could directly suppress the transcription of Aadc, a rate-limiting enzyme during catecholamine synthesis, in a HDAC2-depdendent manner. Importantly, treatment with AADC inhibitor NSD-1015 significantly ameliorated EAP-elicited pain response and catecholamine overactivity in MTA1-/- mice. Taken together, our findings reveal an inherent regulatory role of the MTA1/AADC pathway in the maintenance of catecholamine production homeostasis in prostate ICCs, and also point to a potential use of HDAC inhibitors and/or AADC inhibitors to treat CP/CPPS.

Targeting IL-17A Improves the Dysmotility of the Small Intestine and Alleviates the Injury of the Interstitial Cells of Cajal during Sepsis.

Intestinal dysmotility is a frequent complication during sepsis and plays an important role in the development of secondary infections and multiple organ failure. However, the central mechanisms underlying this process have not been well elucidated. Currently, effective therapies are still lacking for the treatment of sepsis-induced intestinal dysmotility. In this study, we found that the activation of IL-17 signaling within the muscularis propria might be associated with dysmotility of the small intestine during polymicrobial sepsis. Furthermore, we demonstrated that targeting IL-17A partially rescued the motility of the small intestine and alleviated interstitial cells of Cajal (ICC) injury during sepsis. The blockade of IL-17A suppressed the dominant sepsis-induced infiltration of M1-polarized macrophages into the muscularis. Additionally, impaired ICC survival may be associated with the oxidative stress injury induced by dominant infiltration of M1-polarized macrophages. Our findings reveal the important role of the IL-17 signaling pathway in the small intestine during sepsis and provide clues for developing a novel therapeutic strategy for treating gastrointestinal dysmotility during sepsis.

Recently Discovered Interstitial Cell Population of Telocytes: Distinguishing Facts from Fiction Regarding Their Role in the Pathogenesis of Diverse Diseases Called "Telocytopathies".

In recent years, the interstitial cells telocytes, formerly known as interstitial Cajal-like cells, have been described in almost all organs of the human body. Although telocytes were previously thought to be localized predominantly in the organs of the digestive system, as of 2018 they have also been described in the lymphoid tissue, skin, respiratory system, urinary system, meninges and the organs of the male and female genital tracts. Since the time of eminent German pathologist Rudolf Virchow, we have known that many pathological processes originate directly from cellular changes. Even though telocytes are not widely accepted by all scientists as an individual and morphologically and functionally distinct cell population, several articles regarding telocytes have already been published in such prestigious journals as Nature and Annals of the New York Academy of Sciences. The telocyte diversity extends beyond their morphology and functions, as they have a potential role in the etiopathogenesis of different diseases. The most commonly described telocyte-associated diseases (which may be best termed "telocytopathies" in the future) are summarized in this critical review. It is difficult to imagine that a single cell population could be involved in the pathogenesis of such a wide spectrum of pathological conditions as extragastrointestinal stromal tumors ("telocytomas"), liver fibrosis, preeclampsia during pregnancy, tubal infertility, heart failure and psoriasis. In any case, future functional studies of telocytes in vivo will help to understand the mechanism by which telocytes contribute to tissue homeostasis in health and disease.

Overexpression of long non-coding RNA TUG1 alleviates TNF-α-induced inflammatory injury in interstitial cells of Cajal.

OBJECTIVE: Irritable bowel syndrome (IBS) is a common functional disorder in the gastrointestinal tract. Inflammatory response has been found to participate in the pathogenesis of IBS. This study aimed to explore the effects of long non-coding RNA taurine upregulated gene 1 (TUG1) on tumor necrosis factor alpha (TNF-α)-induced interstitial cells of Cajal (ICC) inflammatory injury, which was relevant to the pathogenesis of IBS. PATIENTS AND METHODS: The expression levels of TUG1 and microRNA-127 (miR-127) were analyzed by qRT-PCR. Viability, apoptosis and the expression of apoptosis-associated factors were analyzed by CCK-8 assay, flow cytometry and Western blot, respectively. The mRNA and protein levels of pro-inflammatory cytokines were detected by qRT-PCR and Western blot, respectively. Finally, activations of nuclear factor kappa-B (NF-κB) and Notch pathways were evaluated by Western blot. RESULTS: TNF-α treatment inhibited ICC viability, induced ICC apoptosis and promoted an inflammatory response in ICC. TUG1 was downregulated in TNF-α-treated ICC. TUG1 overexpression protected ICC from TNF-α-induced apoptosis and pro-inflammatory cytokines expression. TUG1 suppression showed opposite effects. MiR-127 was negatively regulated by TUG1 and implicated in the action of TUG1 in ICC. MiR-127 up-regulation largely reversed the effects of TUG1 on TNF-α-treated ICC. Mechanistically, TUG1 inhibited TNF-α-induced activation of NF-κB and Notch pathways in ICC by down-regulating miR-127. CONCLUSIONS: TUG1 attenuated TNF-α-caused apoptosis and inflammatory response in ICC by down-regulating miR-127 and then inactivating NF-κB and Notch pathways.

Involvement of prostatic interstitial cells of Cajal in inflammatory cytokines-elicited catecholamines production: Implications for the pathophysiology of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS).

In a previous work using guinea pig prostate, we have identified a novel interstitial cells of Cajal (ICCs) which possess close contacts between sympathetic nerve bundles and smooth muscle cells. The ability of prostatic ICCs in mediating excitatory neural inputs was therefore studied using isolated murine prostate ICCs by collagenase digestion combined with FACS method. RT-PCR and Western blotting analyses revealed that prostatic ICCs under a quiescent state expressed abundantly the rate-limiting enzymes essential for catecholamine synthesis. Moreover, distinct proinflammatory cytokines (e.g. IL-1ß, IL-8, ICAM-1 and TNF-α) could significantly stimulate the expression levels of the rate-limiting enzymes of catecholamine production in prostate ICCs. Mechanistically, the above-mentioned stimulatory effects of proinflammatory cytokines appeared to be mediated via activation of NF-κB, HIF-1α and HDACs signaling pathways. Considering that prostatic catecholamine overactivity serves as an essential etiology of pelvic pain by indirectly stimulating the smooth muscle cell proliferation, or by directly causing muscular spasm, our results collectively suggest that targeting the NF-κB, HIF-1α and HDACs pathways in prostate ICCs be considered as a new strategy for treatment of chronic pelvic pain syndrome (CPPS) induced by chronic prostatitis (CP). Overall, the current study should shed novel light on the biology of this unique prostate ICCs.

Is there a role of interstitial cells of Cajal and mast cells and eosinophils in appendicitis in children?

BACKGROUND/AIM: The aim of this study was to compare the distribution of interstitial Cajal cells, eosinophils, and mast cells in normal and inflamed appendices, and to evaluate the correlation of presence of these cells with severity of inflammation in appendicitis. MATERIALS AND METHODS: The appendicitis group (n = 30) was divided further into three groups according to the macroscopic description and the histological findings. Ten normal appendices served as controls. Tissue samples were processed for routine histological examination. Additionally, all sections were immunohistochemically stained with CD117 and mast cell tryptase antibodies. RESULTS: When specimens were compared in terms of Cajal cells, the observed mean number for the appendicitis group was 4.9 and for the control group it was 8.3. In contrast, eosinophils and mast cells were significantly increased in the appendicitis group when compared with the control group. CONCLUSION: We detected that eosinophils and mast cells are increased in appendicitis, and correlate with the degree of inflammation of the appendix. The density of interstitial Cajal cells was significantly lower in patients with severe appendix inflammation compared to controls. The histopathological differences observed in this study may help elucidate the pathophysiology of appendicitis.

The immunoprofile of interstitial Cajal cells within adenomyosis/endometriosis lesions.

Adenomyosis and endometriosis are lesions which have aroused the interest for the investigation of antibodies specific to the structures from the composition, but also for the cause behind the appearance of these lesions in completely different structures. The impact they have on fertility is not known entirely, for they are difficult to diagnose. Endometriosis causes infertility and it is a hard to treat lesion. The research performed in the last years has been focused on the so-called linkage analysis, or reverse genetics. It refers to identifying the genes which are prone to developing this affection. We investigated clinically 40 female inpatients (n=40) who had underwent genital surgery and received a variegate diagnosis in the "Sf. Ioan" Emergency Hospital, Bucharest, Romania, between January-September 2014 and also their histopathology and immunohistochemistry. We proceeded with the histopathology examination in order to establish a diagnosis in respect to the admission diagnosis and then, using the ABC (Avidin-Biotin complex) method, we analyzed the immunohistochemistry of the following markers: S100 protein (for detection of ganglia and nerve cells), CD117÷c-kit (selective detection of interstitial Cajal cells - ICC), desmin and vimentin (intermediary filaments for detecting ICC-like cells, which cohabit with uterine myocytes and are not contractile cells) and CD10 (a sensitive and useful immunomarker in the diagnosis of endometrial stroma and, in some cases, of neoplasia). Our study, regarding the immunoprofile of some markers of adenomyosis÷endometriosis lesions, supports the hypothesis that the interstitial Cajal cells are non-reactive, they are not in relationship with investigated lesions, but CD10 is a very useful marker to highlight the endometrial stroma in query cases.

Stem cells for murine interstitial cells of cajal suppress cellular immunity and colitis via prostaglandin E2 secretion.

BACKGROUND & AIMS: After allogeneic transplantation, murine stem cells (SCs) for interstitial cells of Cajal (ICCs), electrical pacemaker, and neuromodulator cells of the gut, were incorporated into gastric ICC networks, indicating in vivo immunosuppression. Immunosuppression is characteristic of bone marrow- and other non-gut-derived mesenchymal stem cells (MSCs), which are emerging as potential therapeutic agents against autoimmune diseases, including inflammatory bowel disease. Therefore, we investigated whether gut-derived ICC-SCs could also mitigate experimental colitis and studied the mechanisms of ICC-SC-mediated immunosuppression in relation to MSC-induced pathways. METHODS: Isolated ICC-SCs were studied by transcriptome profiling, cytokine assays, flow cytometry, mixed lymphocyte reaction, and T-cell proliferation assay. Mice with acute and chronic colitis induced by dextran sulfate sodium and T-cell transfer, respectively, were administered ICC-SCs intraperitoneally and evaluated for disease activity by clinical and pathological assessment and for ICC-SC homing by live imaging. RESULTS: Unlike strain-matched dermal fibroblasts, intraperitoneally administered ICC-SCs preferentially homed to the colon and reduced the severity of both acute and chronic colitis assessed by clinical and blind pathological scoring. ICC-SCs profoundly suppressed T-cell proliferation in vitro. Similar to MSCs, ICC-SCs strongly expressed cyclooxygenase 1/2 and basally secreted prostaglandin E2. Indomethacin, a cyclooxygenase inhibitor, countered the ICC-SC-mediated suppression of T-cell proliferation. In contrast, we found no role for regulatory T-cell-, programmed death receptor-, and transforming growth factor-ß-mediated mechanisms reported in MSCs; and transcriptome profiling did not support a relationship between ICC-SCs and MSCs. CONCLUSIONS: Murine ICC-SCs belong to a class different from MSCs and potently mitigate experimental colitis via prostaglandin E2-mediated immunosuppression.

Autoimmunity Links Vinculin to the Pathophysiology of Chronic Functional Bowel Changes Following Campylobacter jejuni Infection in a Rat Model.

BACKGROUND: Acute gastroenteritis can precipitate irritable bowel syndrome (IBS) in humans. Cytolethal distending toxin is common to all pathogens causing gastroenteritis. Its active subunit, CdtB, is associated with post-infectious bowel changes in a rat model of Campylobacter jejuni infection, including small intestinal bacterial overgrowth (SIBO). AIM: To evaluate the role of host antibodies to CdtB in contributing to post-infectious functional sequelae in this rat model. METHODS: Ileal tissues from non-IBS human subjects, C. jejuni-infected and control rats were immunostained with antibodies to CdtB, c-Kit, S-100, PGP 9.5 and vinculin. Cytosolic and membrane proteins from mouse enteric neuronal cell lysates were immunoprecipitated with anti-CdtB and analyzed by mass spectrometry. ELISAs were performed on rat cardiac serum using CdtB or vinculin as antigens. RESULTS: Anti-CdtB antibodies bound to a cytosolic protein in interstitial cells of Cajal (ICC) and myenteric ganglia in C. jejuni-infected and naïve rats and human subjects. Mass spectrometry identified vinculin, confirmed by co-localization and ELISAs. Anti-CdtB antibodies were higher in C. jejuni-infected rats (1.27 ± 0.15) than controls (1.76 ± 0.12) (P < 0.05), and rats that developed SIBO (2.01 ± 0.18) vs. rats that did not (1.44 ± 0.11) (P = 0.019). Vinculin expression levels were reduced in C. jejuni-infected rats (0.058 ± 0.053) versus controls (0.087 ± 0.023) (P = 0.0001), with greater reductions in rats with two C. jejuni infections (P = 0.0001) and rats that developed SIBO (P = 0.001). CONCLUSIONS: Host anti-CdtB antibodies cross-react with vinculin in ICC and myenteric ganglia, required for normal gut motility. Circulating antibody levels and loss of vinculin expression correlate with number of C. jejuni exposures and SIBO, suggesting that effects on vinculin are important in the effects of C. jejuni infection on the host gut.

Immunohistochemical alterations of cajal-like type of tubal interstitial cells in women with endometriosis and tubal ectopic pregnancy.

PURPOSE: The aim of the study was to observe alterations of pacemaker cells termed cajal-like type of tubal interstitial cells (t-ICC) in oviduct from early-stage EMs and tEP, discuss underlying mechanisms and potential role in tubal factor infertility (TFI). METHODS: Ten patients with early-stage EMs, 10 with unruptured tEP and 10 control subjects were included in this retrospective comparative study, received adnexectomy (salpingectomy) and/or hysterectomy. Paraffin-embedded full-thickness isthmic segment of oviduct specimens received immunohistochemistry with c-kit/CD117 antibody. Network distribution and area density of cells with features of t-ICC were analyzed. RESULTS: t-ICC was detected mainly in lamina propria and smooth muscle layers. t-ICC lost its network integrity, became less densely stained, sparse and almost invisible with relatively very rare connections in EMs and tEP, apparently differing in morphology of t-ICC from control, which demonstrated rich t-ICC immunostaining and intact network. Further quantitative analysis showed the area density of t-ICC decreased significantly in early-stage EMs and tEP compared with the control (73.9 ± 8.8 vs. 156 ± 18.3 mm(2); and 76 ± 7.4 vs. 156 ± 18.3 mm(2); both P < 0.001). CONCLUSIONS: We revealed that t-ICC underwent certain degree of cell damage, suggested that decreased expression of t-ICC network may be involved in early development of EMs and tEP, and might serve as an explanation for TFI in these patients.

Reduced population of interstitial cells of Cajal in Chagasic megacolon.

BACKGROUND/AIMS: In Chagasic megacolon, there is a reduction in the population of interstitial cells of Cajal. It was aimed to evaluate density of Cajal cells in the resected colon of Chagasic patients compared to control patients and to verify possible association between preoperative and postoperative bowel function of megacolon patients and cell count. METHODOLOGY: Sixteen megacolon patients (12 female; mean age 54.4 (31-73)) were operated on. Pre- and postoperative evaluation using Cleveland clinic constipation score was undertaken. Resected colons were examined. Cajal cells were identified by immunohistochemistry (anti-CD117). The mean cell number was compared to resected colons from 16 patients (7 female; mean age 62.8 (23-84)) with non-obstructive sigmoid cancer. Association between pre- and postoperative constipation scores and cell count for megacolon patients was evaluated using the Pearson test (r). RESULTS: A reduced number of Cajal cells (per field: 2.84 (0-6.6) vs. 9.68 (4.3-13); p<0.001) were observed in the bowel of megacolon patients compared to cancer patients. No correlation between constipation score before (r=- 0.205; p=0.45) or after surgery (r=0.291; p=0.28) and cell count in megacolon was observed. CONCLUSIONS: Patients with megacolon display marked reduction of interstitial cells of Cajal. An association of constipation severity and Cajal cells depopulation was not demonstrated.

Kitlow stem cells cause resistance to Kit/platelet-derived growth factor alpha inhibitors in murine gastrointestinal stromal tumors.

BACKGROUND & AIMS: Gastrointestinal stromal tumors (GIST) are related to interstitial cells of Cajal (ICC) and often contain activating stem cell factor receptor (Kit) or platelet-derived growth factor receptor alpha (Pdgfra) mutations. Kit/Pdgfra inhibitors such as imatinib mesylate have increased progression-free survival in metastatic GIST but are not curative. In mouse models we investigated whether Kit(low) ICC progenitors could represent an inherently Kit/Pdgfra inhibitor-resistant reservoir for GIST. METHODS: Isolated Kit(low)Cd44(+)Cd34(+) cells were characterized after serial cloning. The tumorigenic potential of spontaneously transformed cells was investigated in nude mice. The Kit(low)Cd44(+)Cd34(+) cells' responsiveness to Kit activation and blockade was studied by enumerating them in Kit(K641E) mice (a GIST model), in mice with defective Kit signaling, and pharmacologically. RESULTS: Single isolated Kit(low)Cd44(+)Cd34(+) cells were clonogenic and capable of self-renewal and differentiation into ICC. In nude mice, spontaneously transformed cells formed malignant tumors expressing GIST markers. The Kit(low)Cd44(+)Cd34(+) cells were resistant to in vitro Kit blockade, including by imatinib, and occurred in normal numbers in mice with reduced Kit signaling. In Kit(K641E) mice, the mutant ICC stem cells were grossly hyperplastic but remained imatinib-resistant. In contrast, the cancer stem, cell-targeting drug salinomycin blocked the proliferation of Kit(low)Cd44(+)Cd34(+) cells and increased their sensitivity to imatinib. CONCLUSIONS: Kit(low)Cd44(+)Cd34(+) progenitors are true stem cells for normal and hyperplastic ICC and give rise to GIST. Resistance to Kit/Pdgfra inhibitors is inherent in GIST and is caused by the native ICC stem cells' lack of dependence on Kit for survival, which is maintained after the acquisition of oncogenic Kit mutation. Cancer stem cell drugs may target these cells.

Telocytes in human term placenta: morphology and phenotype.

In the last few years, a new cell type - interstitial Cajal-like cell (ICLC) - has been described in digestive and extra-digestive organs. The name has recently been changed to telocytes (TC) and their typical thin, long processes have been named telopodes (TP). To support the hypothesis that TC may also be present in human placenta and add to the information already available, we provide evidence on the ultrastructure, immunophenotype, distribution, and interactions with the surrounding stromal cells of TC in the villous core of human term placenta. We used phase-contrast microscopy, light microscopy of semithin sections, transmission electron microscopy, immunohistochemistry, and immunofluorescence of tissue sections or cell cultures, following a pre-established diagnostic algorithm. Transmission electron microscopy showed cells resembling TC, most (∼76%) having 2-3 very thin, longprocesses (tens to hundreds of micrometers), with an uneven calibre(≤0.5 µm thick) and typical branching pattern. The dilations of processes accommodate caveolae, endoplasmic reticulum cisternae, and mitochondria. These TC have close contacts with perivascular SMC in stem villi. In situ, similar cells are positive for c-kit, CD34, vimentin, caveolin-1, vascular endothelial growth factor (VEGF), and inducible nitric oxide synathase (iNOS). The c-kit-positive cells inconsistently co-express CD34, CD44, αSMA, S100, neuron-specific enolase, and nestin. Among cells with a morphologic TC profile in cell cultures, about 13% co-express c-kit, vimentin, and caveolin-1; 70% of the c-kit-positive cells co-express CD34 and 12% co-express iNOS or VEGF. In conclusion, this study confirms the presence of TC in human term placenta and provides their ultrastructural and immunophenotypic characterization.