Extracellular Microvesicles (ExMVs) in Cell to Cell Communication: A Role of Telocytes

Elucidating the preventive and therapeutic effects of cardiac telocytes paracrine microRNAs on ischemic heart disease

Telocytes (TCs), a newly identified type of mesenchymal cell since 2010, possess substantial potential in maintaining tissue homeostasis, orchestrating organ development, and facilitating tissue regeneration. Their distribution in blood, the adventitia of blood vessels, and the intima implies a close association with vascular function. Ischemic heart disease (IHD), a significant challenge in cardiovascular disease, is characterized by the occlusion of major vessels, obstruction of collateral circulation, and disruption of the capillary network-pathological features closely linked to endothelial cell damage. Myocardial tissue is rich in cardiac telocytes (cTCs), which, following myocardial injury, can secrete numerous miRNAs that promote angiogenesis, including miR-let-7e, miR-10a, and miR-126-3p. This indicates that cTCs may have therapeutic potential for IHD. The primary mechanism by which cTCs-derived exosomes exert paracrine effects is through reducing endothelial cell injury, suggesting that enhancing the production of cTCs could offer a novel therapeutic approach for treating IHD.

Vascular endothelial growth factor facilitates the effects of telocytes on tumor cell proliferation and migration

Background

Telocytes, recently recognized as interstitial cells with a diverse range of potential functions, have attracted considerable attention for their involvement in tumorigenesis. Nevertheless, owing to certain challenges in the isolation and cultivation of telocytes, the research on telocytes has advanced rather slowly. Therefore, it is imperative to study the role and mechanisms of telocytes in tumors.

Methods

We improved the separation method and successfully isolated telocytes by exploiting the combination of cell adhesion and magnetic bead sorting. Telocytes conditioned medium was collected to culture tumor cells and explore the role and mechanisms of telocytes in tumors.

Results

MTT and colony formation assays demonstrated that telocytes promoted tumor cell proliferation. Wound healing experiments and transwell assays indicated that telocytes enhanced tumor cell migration. Real-time reverse transcriptase PCR analysis showed that the expression of E-cadherin was decreased, and that of Vimentin was notably increased. ELISA results revealed that telocytes secreted high levels of vascular endothelial growth factor (VEGF). And the promoting effects were alleviated by the VEGF inhibitor bevacizumab.

Conclusion

Our findings revealed that telocytes promoted tumor cell proliferation, migration, and angiogenesis through VEGF. Notably, these effects were inhibited by the addition of bevacizumab. In conclusion, our findings illuminated the role of telocytes in promoting tumor progression, and confirmed their crucial regulatory role in the growth of tumor cells.

Transcriptomic and histological characterization of telocytes in the human dorsal root ganglion

Telocytes are interstitial cells with long processes that cover distances in tissues and likely coordinate interacts with other cell types. Though present in central and peripheral neuronal tissues, their role remains unclear. Dorsal root ganglia (DRG) house pseudounipolar afferent neurons responsible for signals such as temperature, proprioception and nociception. This study aimed to investigate the presence and function of telocytes in human DRG by investigating their transcriptional profile, location and ultrastructure. Sequencing data revealed CD34 and PDGFRA expressing cells comprise roughly 1.5-3% of DRG cells. Combined expression of CD34 and PDGFRA is a putative marker gene set for telocytes. Further analysis identified nine subclusters with enriched cluster-specific genes. KEGG and GO pathway analysis suggested vascular, immune and connective tissue associated putative telocyte subtypes. Over 3000 potential receptor-ligand interactions between sensory neurons and these CD34 and PDGFRA expressing putative telocytes were identified using a ligand-receptors interactome platform. Immunohisto-chemistry showed CD34+ telocytes in the endoneural space of DRGs, next to neuron-satellite complexes, in perivascular spaces and in the endoneural space between nerve fibre bundles, consistent with pathway analysis. Transmission electron microscopy (TEM) confirmed their location identifying characteristic elongated nucleus, long and thin telopods containing vesicles, surrounded by a basal lamina. This is the first study that provides gene expression analysis of telocytes in complex human tissue such as the DRG, highlighting functional differences based on tissue location with no significant ultrastructural variation.

The extracellular vesicles in HIV infection and progression: mechanisms, and theranostic implications

Extracellular vesicles (EVs), these minute yet mighty cellular messengers are redefining our understanding of a spectrum of diseases, from cancer to cardiovascular ailments, neurodegenerative disorders, and even infectious diseases like HIV. Central to cellular communication, EVs emerge as both potent facilitators and insightful biomarkers in immune response and the trajectory of disease progression. This review ventures deep into the realm of EVs in HIV-unraveling their pivotal roles in diagnosis, disease mechanism unravelling, and therapeutic innovation. With a focus on HIV, we will highlights the transformative potential of EVs in both diagnosing and treating this formidable virus. Unveiling the intricate dance between EVs and HIV, the review aims to shed light on novel therapeutic strategies that could significantly benefit HIV therapy, potentially even leading to the eradication of HIV.

Platelet Microvesicles, Inflammation, and Coagulation Markers: A Pilot Study

BACKGROUND

Platelet "Microvesicles" (MVs) are studied for their role in blood coagulation and inflammation. The study aimed to establish if MVs are related to age, plasma levels of inflammation, coagulation, and fibrinolysis markers in healthy individuals.

METHODS

We prospectively enrolled volunteers aged over 18 years. MVs, plasma levels of C-reactive protein (CRP), Interleukin 6 (IL-6), Interleukin 10 (IL-10), Interleukin 17 (IL-17), and transforming growth factor β (TGF-β), fibrinogen, plasminogen activator inhibitor-1 (PAI-1), von Willebrand factor (VWF), homocysteine, factor VII (FVII), thrombin activatable fibrinolysis inhibitor (TAFI), and Protein S were tested.

RESULTS

A total of 246 individuals (median age 65 years ("IQR"54-72)) were evaluated. Both univariate analysis and logistic regression models showed that MVs positively correlate with age, CRP, IL-6, IL-10, IL-17, TGF-β, fibrinogen, PAI-1, VWF, FVII, and homocysteine, while inversely correlating with TAFI and Protein S. The ROC curve analysis performed to identify a cut off for MV values (700 kMP) showed a good accuracy with over-range cytokines fibrinolysis factor and coagulation markers.

CONCLUSIONS

To the best of our knowledge, this study is the first to correlate MVs with an entire panel of cardiovascular risk factors in healthy individuals. A future possible role of MVs in screening exams is suggested.

Therapeutic potential in rheumatic diseases of extracellular vesicles derived from mesenchymal stromal cells

The incidence of rheumatic diseases such as rheumatoid arthritis and osteoarthritis and injuries to articular cartilage that lead to osteochondral defects is predicted to rise as a result of population ageing and the increase in high-intensity physical activities among young and middle-aged people. Current treatments focus on the management of pain and joint functionality to improve the patient's quality of life, but curative strategies are greatly desired. In the past two decades, the therapeutic value of mesenchymal stromal cells (MSCs) has been evaluated because of their regenerative potential, which is mainly attributed to the secretion of paracrine factors. Many of these factors are enclosed in extracellular vesicles (EVs) that reproduce the main functions of parental cells. MSC-derived EVs have anti-inflammatory, anti-apoptotic as well as pro-regenerative activities. Research on EVs has gained considerable attention as they are a potential cell-free therapy with lower immunogenicity and easier management than whole cells. MSC-derived EVs can rescue the pathogenetic phenotypes of chondrocytes and exert a protective effect in animal models of rheumatic disease. To facilitate the therapeutic use of EVs, appropriate cell sources for the production of EVs with the desired biological effects in each disease should be identified. Production and isolation of EVs should be optimized, and pre-isolation and post-isolation modifications should be considered to maximize the disease-modifying potential of the EVs.

A cellular regulator of the niche: telocyte

Interstitial cells are present in the environment of stem cells in order to increase stem cell proliferation and differentiation and they are important to increase the efficiency of their transplantation. Telocytes (TCs) play an important role both in the preservation of tissue organ integrity and in the pathophysiology of many diseases, especially cancer. They make homo- or heterocellular contacts to form the structure of 3D network through their telopodes and deliver signaling molecules via a juxtacrine and/or paracrine association by budding shed vesicles into the vascular, nervous and endocrine systems. During this interaction, along with organelles, mRNA, microRNA, long non-coding RNA, and genomic DNA are transferred. This review article not only specifies the properties of TCs and their roles in the tissue organ microenvironment but also gives information about the factors that play a role in the transport of epigenetic information by TCs.

Telocytes and ezrin expression in normal-appearing tissues adjacent to urothelial bladder carcinoma as predictors of invasiveness and recurrence

Recurrence and progression rates vary widely among different histological subtypes of bladder cancer (BC). Normal-appearing mucosa in non-muscle invasive bladder cancer and muscle-invasive bladder cancer in cystoscopy and histopathology is a factor in staging and treatment. Telocytes (TCs) are spindle-shaped cells that connect with other cell types allowing communication though cytoskeletal signaling. They are involved in tissue regeneration and pathogenesis of diseases and cancer. In this study, 12 normal-appearing tissues from urinary bladder with BC, both invasive and non-invasive were evaluated in patients who had either trans-urethral resection of bladder tumor or cystectomy. In each case, cystoscopy, intraoperative inspection, and histopathology all confirmed the absence of cancerous elements. Five patients with neurogenic bladder were used as a control group. Immunohistochemistry revealed that c-Kit + cells were intensively distributed in bladder layers from BC samples, while they were seldom detected in the control group. Ultrastructural examination of reprocessed tissue showed an intense distribution of TCs and telopodes in the submucosa and between smooth muscle cells in BC. Telopodes were numerous, arborizing, and intercommunicating. Whereas TCs and telopodes were scarce in the neurogenic bladder. Also, cancerous tissue had the highest expression level of ezrin protein, and this level gradually decreased as we moved away from the tumor. Our finding of TCs number in normal-appearing tissues in conjunction with ezrin expression may compete invasiveness and possibly a trail to reduce recurrence rates.

Morphological and histochemical identification of telocytes in adult yak epididymis

Telocytes (TCs) are a newly discovered type of mesenchymal cell that are closely related to the tissue's internal environment. The study aimed to investigate the morphological identification of TCs in the epididymis of adult yak and their role in the local microenvironment. In this study, transmission electron microscopy (TEM), scanning electron microscopy, immunofluorescence, qRT-PCR, and western blotting were used to analyze the cell morphology of TCs. The results showed that there are two types of TCs in the epididymal stroma of yak by TEM; one type is distributed around the capillaries with full cell bodies, longer TPs, and a large number of secretory vesicles; the other is distributed outside the basement membrane with irregularly long, striped, large nuclei and short telopodes (TPs). In addition, these TCs formed complex TC cell networks through TPs with epididymal interstitial capillaries and basal fibroblasts. TCs often appear near the capillaries and basement membrane by special staining. The surface markers of TCs (CD34, vimentin, and CD117) were positively expressed in the epididymal stroma and epithelium by immunohistochemistry, and immunofluorescence co-expression of vimentin + CD34 and CD117 + CD34 was observed on the surface of TCs. The trends in the mRNA and protein expression of TCs surface markers revealed expression was highest in the caput epididymis. In summary, this is first report of TCs in the epididymis of yak, and two phenotypes of TCs were observed. The existence and distribution characteristics of TCs in the epididymis of plateau yaks provide important clues for further study of the adaptation to reproductive function in the plateau.

Extracellular Vesicles Isolated from Malignant Mesothelioma Cancer-Associated Fibroblasts Induce Pro-Oncogenic Changes in Healthy Mesothelial Cells

Malignant mesothelioma is an aggressive tumour of the pleura (MPM) or peritoneum with a clinical presentation at an advanced stage of the disease. Current therapies only marginally improve survival and there is an urgent need to identify new treatments. Carcinoma-associated fibroblasts (CAFs) represent the main component of a vast stroma within MPM and play an important role in the tumour microenvironment. The influence of CAFs on cancer progression, aggressiveness and metastasis is well understood; however, the role of CAF-derived extracellular vesicles (CAF-EVs) in the promotion of tumour development and invasiveness is underexplored. We purified CAF-EVs from MPM-associated cells and healthy dermal human fibroblasts and examined their effect on cell proliferation and motility. The data show that exposure of healthy mesothelial cells to EVs derived from CAFs, but not from normal dermal human fibroblasts (NDHF) resulted in activating pro-oncogenic signalling pathways and increased proliferation and motility. Consistent with its role in suppressing Yes-Associated Protein (YAP) activation (which in MPM is a result of Hippo pathway inactivation), treatment with Simvastatin ameliorated the pro-oncogenic effects instigated by CAF-EVs by mechanisms involving both a reduction in EV number and changes in EV cargo. Collectively, these data determine the significance of CAF-derived EVs in mesothelioma development and progression and suggest new targets in cancer therapy.

Telocytes’ Role in Modulating Gut Motility Function and Development: Medical Hypotheses and Literature Review

This review article explores the telocytes’ roles in inflammatory bowel diseases (IBD), presenting the mechanisms and hypotheses related to epithelial regeneration, progressive fibrosis, and dysmotility as a consequence of TCs’ reduced or absent number. Based on the presented mechanisms and hypotheses, we aim to provide a functional model to illustrate TCs’ possible roles in the normal and pathological functioning of the digestive tract. TCs are influenced by the compression of nearby blood vessels and the degree of fibrosis of the surrounding tissues and mediate these processes in response. The changes in intestinal tube vascularization induced by the movement of the food bowl, and the consequent pH changes that show an anisotropy in the thickness of the intestinal tube wall, have led to the identification of a pattern of intestinal tube development based on telocytes’ ability to communicate and modulate surrounding cell functions. In the construction of the theoretical model, given the predictable occurrence of colic in the infant, the two-layer arrangement of the nerve plexuses associated with the intestinal tube was considered to be incompletely adapted to the motility required with a diversified diet. There is resulting evidence of possible therapeutic targets for diseases associated with changes in local nerve tissue development.

The Pannexin 1/Purinergic Receptor P2X4 Pathway Controls the Secretion of MicroRNA-Containing Exosomes by HCV-Infected Hepatocytes

BACKGROUND AND AIMS

HCV infection is a major risk factor that can lead to chronic liver disease, including fibrosis, cirrhosis, and HCC. Progression of chronic liver disease by HCV infection is caused by a complex intercellular reaction. Especially, exosomes and microRNAs (miRNAs) from HCV-infected hepatocytes play a role in the pathogenesis of liver disease by facilitating cellular communication between parenchymal and nonparenchymal cells. However, the underlying mechanism of secretions of exosome and miRNAs during HCV infection is still open for study.

APPROACH AND RESULTS

In this study, we demonstrated a pathway for the release of exosome and exosomal miRNAs through caspase-3/pannexin 1 (Panx1)/P2X4 activation during HCV infection in hepatocytes. We found that HCV infection induced the stimulation of exosome release and activation of the caspase-3/Panx1/P2X4 pathway in Huh7.5.1 cells. In addition, miR-122 and miR-146a levels in extracellular exosomes from HCV-infected cells were dramatically increased whereas intracellular miR122 and miR-146a expression had no large changes. Notably, secretions of exosomes and exosomal miRNAs were decreased by inhibition of caspase 3, Panx1, and P2X4 whereas inhibition of ROCK-1 cleavage did not affect these during HCV infection in Huh7.5.1 cells.

CONCLUSIONS

These results suggested that HCV infection caused secretions of exosomes and exosomal miRNAs dependent on the caspase 3/Panx1/P2X4 pathway. Our study provides a possible therapeutic intervention using Panx1 suppression for liver disease development mediated by exosomes from HCV-infected hepatocytes.

Telocytes in the Tumor Microenvironment

There are several theories explaining the communication between cells in the context of tumor development. Over the years, interactions between normal and transformed cells have been observed. Generally, all types of cells make equal contributions to the formation of the tumor microenvironment - a location of primary oncogenesis. To date, several studies have reported the role of telocytes in cancer development, and many publications have emphasized the direct and indirect involvement of telocytes in angiogenesis; signaling through the secretion of extracellular vesicles, growth factors, and bioactive molecules; fibrosis development and extracellular matrix production; tissue repair and regeneration; and immune responses. Considering the main components of the tumor microenvironment, we will discuss the features of telocytes and their possible involvement in local tissue homeostasis.

Bone mesenchymal stem cell-derived extracellular vesicles promote the repair of intervertebral disc degeneration by transferring microRNA-199a

Extracellular vesicles (EVs) secreted by bone marrow mesenchymal stem cells (BMSCs) protect intervertebral disc degeneration (IDD) by regulating nucleus pulposus cell (NPC) apoptosis. But the mechanism of BMSCs-EVs-microRNA (miR)-199a in IDD remains unclear. In this study, after the acquisition and identification of BMSCs and BMSCs-EVs, IDD mouse model was established and treated with BMSCs-EVs. The pathological changes of NPCs, positive expression of MMP-2, MMP-6 and TIMP1, and the senescence and apoptosis of NPCs were evaluated. Microarray analysis was employed to analyze the differentially expressed miRs and genes after EV treatment. NPCs were treated with EVs/miR-199a/TGF-β agonist SRI-011381. The positive expression of col II and Aggrecan was assessed. The target gene and downstream pathway of miR-199a were analyzed. In vivo experiment, after BMSCs-EV treatment, MMP-2, MMP-6, TIMP1 and TUNEL-positive cells in IDD mice were decreased, and miR-199a was increased. In vitro experiments, the expression of col Ⅱ and Aggrecan, SA-β gal positive cells and apoptosis rate of NPCs were decreased after EV intervention. The protective effect of BMSCs-EVs on NPCs was impaired by reducing miR-199a carried by EVs. miR-199a could target GREM1 to inactivate the TGF-β pathway. miR-199a carried by BMSCs-EVs promotes IDD repair by targeting GREM1 and downregulating the TGF-β pathway. Our work confers a promising therapeutic strategy for IDD.

Potential Roles of Adipocyte Extracellular Vesicle-Derived miRNAs in Obesity-Mediated Insulin Resistance

Recently, extracellular microRNAs (miRNAs) from adipose tissue have been shown to be involved in the development of insulin resistance. Here, we summarize several mechanisms explaining the pathogenesis of obesity-induced insulin resistance and associated changes in the expression of obesity-associated extracellular miRNAs. We discuss how miRNAs, particularly miR-27a, miR-34a, miR-141-3p, miR-155, miR210, and miR-222, in extracellular vesicles secreted from the adipose tissue can affect the insulin signaling pathway in metabolic tissue. Understanding the role of these miRNAs will further support the development of therapeutics for obesity and metabolic disorders such as type 2 diabetes.

Circulating MicroRNA-19b Identified From Osteoporotic Vertebral Compression Fracture Patients Increases Bone Formation

Circulating microRNAs (miRNAs) play important roles in regulating gene expression and have been reported to be involved in various metabolic diseases, including osteoporosis. Although the transcriptional regulation of osteoblast differentiation has been well characterized, the role of circulating miRNAs in this process is poorly understood. Here we discovered that the level of circulating miR-19b was significantly lower in osteoporotic patients with vertebral compression fractures than that of healthy controls. The expression level of miR-19b was increased during osteoblastic differentiation of human mesenchymal stem cells (hMSCs) and MC3T3-E1 cells, and transfection with synthetic miR-19b could promote osteoblastic differentiation of hMSCs and MC3T3-E1 cells. PTEN (phosphatase and tensin homolog deleted from chromosome 10) was found to be directly repressed by miR-19b, with a concomitant increase in Runx2 expression and increased phosphorylation of AKT (protein kinase B, PKB). The expression level of circulating miR-19b in aged ovariectomized mice was significantly lower than in young mice. Moreover, the osteoporotic bone phenotype in aged ovariectomized mice was alleviated by the injection of chemically modified miR-19b (agomiR-19b). Taken together, our results show that circulating miR-19b plays an important role in enhancing osteoblastogenesis, possibly through regulation of the PTEN/pAKT/Runx2 pathway, and may be a useful therapeutic target in bone loss disorders, such as osteoporosis. © 2019 American Society for Bone and Mineral Research.

Morphological and immunophenotypic characterization of perivascular interstitial cells in human glioma: Telocytes, pericytes, and mixed immunophenotypes

Telocytes (Tcs) and pericytes (Pcs) are two types of perivascular interstitial cell known to be widespread in various organs and tissues, including the brain. We postulated that Tcs and Pcs may be involved in glioblastoma (GBM) neovascularization.

Changes in the telocyte/CD34+ stromal cell and α-SMA+ myoid cell networks in human testicular seminoma

Telocytes (TCs), also known as CD34+ stromal/interstitial cells, have recently been identified within the connective tissue of a variety of organs including the normal human testis. Testicular TCs appear to constitute a widespread reticular network distributed either in the peritubular or in the intertubular stromal spaces where they have been suggested to play different roles, such as participation to testis morphogenesis, postnatal preservation of the normal tissue/organ three-dimensional structure, and regulation of spermatogenesis and androgen hormone secretion and release. Although increasing evidence indicates that TCs may be involved in the pathophysiology of various diseases, no study has yet reported possible changes in these cells within the stromal compartment of seminoma, one of the most frequent malignant testicular cancers in humans. Therefore, here we carried out the first investigation of the presence and tissue distribution of TCs/CD34+ stromal cells in human testicular seminoma in comparison with normal human testis using either CD34 immunohistochemistry or CD34/CD31 and CD34/α-smooth muscle actin (α-SMA) double immunofluorescence analyses. In seminoma tissue sections, we observed an overall loss of TCs (CD34+/CD31- stromal cells) accompanying a severe degeneration of the normal architecture of seminiferous tubules and stromal tissue associated with dense cellularity increase and presence of interstitial fibrosis. Noteworthy, in the seminoma tissue the disappearance of TCs was paralleled by an expansion of α-SMA+ myoid cells. Moreover, the CD34+/CD31+ blood vessel network was greatly expanded, while steroidogenic Leydig cells were undetectable in seminoma specimens. Since TCs are emerging as important regulators of tissue and organ homeostasis, collectively the present findings indicate that the possible pathophysiologic implications of the loss of TCs in human testicular seminoma should not be further overlooked.

Morphological evidence for telocytes as stromal cells supporting satellite cell activation in eccentric contraction-induced skeletal muscle injury

Although telocytes (TCs) have been proposed to play a “nursing” role in resident satellite cell (SC)-mediated skeletal muscle regeneration, currently there is no evidence of TC-SC morpho-functional interaction following tissue injury. Hence, we explored the presence of TCs and their relationship with SCs in an ex vivo model of eccentric contraction (EC)-induced muscle damage. EC-injured muscles showed structural/ultrastructural alterations and changes in electrophysiological sarcolemnic properties. TCs were identified in control and EC-injured muscles by either confocal immunofluorescence (i.e. CD34⁺CD31⁻ TCs) or transmission electron microscopy (TEM). In EC-injured muscles, an extended interstitial network of CD34⁺ TCs/telopodes was detected around activated SCs displaying Pax7⁺ and MyoD⁺ nuclei. TEM revealed that TCs invaded the SC niche passing with their telopodes through a fragmented basal lamina and contacting the underlying activated SCs. TC-SC interaction after injury was confirmed in vitro by culturing single endomysial sheath-covered myofibers and sprouting TCs and SCs. EC-damaged muscle-derived TCs showed increased expression of the recognized pro-myogenic vascular endothelial growth factor-A, and SCs from the same samples exhibited increased MyoD expression and greater tendency to fuse into myotubes. Here, we provide the essential groundwork for further investigation of TC-SC interactions in the setting of skeletal muscle injury and regenerative medicine.

Inhibition of the Notch1 Pathway Promotes the Effects of Nucleus Pulposus Cell-Derived Exosomes on the Differentiation of Mesenchymal Stem Cells into Nucleus Pulposus-Like Cells in Rats

Stem cell therapies for intervertebral disc degeneration have been demonstrated as a promising strategy. Previous studies have shown that human nucleus pulposus cell- (NPC-) derived exosomes can induce the differentiation of mesenchymal stem cells (MSCs) into NP-like cells in vitro. However, the mechanism of MSC differentiation into NP-like cells with the induction of NPC exosomes is still unclear. Here, we verified the induction effects of NPC exosomes on the differentiation of MSCs into NP-like cells. In addition, the Notch1 pathway was downregulated in this process. Then, DAPT and soluble Jagged1 (SJAG) were applied to inhibit or enhance the expression of the Notch1 pathway, respectively, resulting in the upregulation or downregulation of collagen II, aggrecan, and Sox9 in MSCs. Knocking down of Notch1 protein facilitated the effects of NPC exosomes on the differentiation of MSCs into NP-like cells. NPC exosomes were more effective than an indirect coculture system in terms of the differentiation of MSCs into NP-like cells. Inhibition of NPC exosome secretion with Rab27a siRNA prevented the induction effects of an indirect coculture system on the differentiation of MSCs into NP-like cells. Transwell migration assays revealed that NPC exosomes could promote the migration of MSCs. Taken together, the Notch1 pathway was negatively associated with the differentiation of MSCs into NP-like cells with the treatments of NPC exosomes. Inhibition of the Notch1 pathway facilitates NPC exosome-induced differentiation of MSCs into NP-like cells in vitro. NPC exosomes play a key role in the differentiation of MSCs into NP-like cells in an indirect coculture system of NPCs and MSCs.

The Multifactorial Etiopathogeneses Interplay of Inflammatory Bowel Disease: An Overview

The gastrointestinal system where inflammatory bowel disease occurs is central to the immune system where the innate and the adaptive/acquired immune systems are balanced in interactions with gut microbes under homeostasis conditions. This article overviews the high-throughput research screening on multifactorial interplay between genetic risk factors, the intestinal microbiota, urbanization, modernization, Westernization, the environmental influences and immune responses in the etiopathogenesis of inflammatory bowel disease in humans. Inflammatory bowel disease is an expensive multifactorial debilitating disease that affects thousands new people annually worldwide with no known etiology or cure. The conservative therapeutics focus on the established pathology where the immune dysfunction and gut injury have already happened but do not preclude or delay the progression. Inflammatory bowel disease is evolving globally and has become a global emergence disease. It is largely known to be a disease in industrial-urbanized societies attributed to modernization and Westernized lifestyle associated with environmental factors to genetically susceptible individuals with determined failure to process certain commensal antigens. In the developing nations, increasing incidence and prevalence of inflammatory bowel disease (IBD) has been associated with rapid urbanization, modernization and Westernization of the population. In summary, there are identified multiple associations to host exposures potentiating the landscape risk hazards of inflammatory bowel disease trigger, that include: Western life-style and diet, host genetics, altered innate and/or acquired/adaptive host immune responses, early-life microbiota exposure, change in microbiome symbiotic relationship (dysbiosis/dysbacteriosis), pollution, changing hygiene status, socioeconomic status and several other environmental factors have long-standing effects/influence tolerance. The ongoing multipronged robotic studies on gut microbiota composition disparate patterns between the rural vs. urban locations may help elucidate and better understand the contribution of microbiome disciplines/ecology and evolutionary biology in potentially protecting against the development of inflammatory bowel disease.

Extracellular Vesicles: New Players in Lymphomas

Lymphomas are heterogeneous diseases, and the term includes a number of histological subtypes that are characterized by different clinical behavior and molecular phenotypes. Valuable information on the presence of lymphoma cell-derived extracellular vesicles (LCEVs) in the bloodstream of patients suffering from this hematological cancer has recently been provided. In particular, it has been reported that the number and phenotype of LCEVs can both change as the disease progresses, as well as after treatment. Moreover, the role that LCEVs play in driving tumor immune escape has been reported. This makes LCEVs potential novel clinical tools for diagnosis, disease progression, and chemoresistance. LCEVs express surface markers and convey specific molecules in accordance with their cell of origin, which can be used as targets and thus lead to the development of specific therapeutics. This may be particularly relevant since circulating LCEVs are known to save lymphoma cells from anti-cluster of differentiation (CD)20-induced complement-dependent cytotoxicity. Therefore, effort should be directed toward investigating the feasibility of using LCEVs as predictive biomarkers of disease progression and/or response to treatment that can be translated to clinical use. The use of liquid biopsies in combination with serum EV quantification and cargo analysis have been also considered as potential approaches that can be pursued in the future. Upcoming research will also focus on the identification of specific molecular targets in order to generate vaccines and/or antibodies against LCEVs. Finally, the removal of circulating LCEVs has been proposed as a simple and non-invasive treatment approach. We herein provide an overview of the role of LCEVs in lymphoma diagnosis, immune tolerance, and drug resistance. In addition, alternative protocols that utilize LCEVs as therapeutic targets are discussed.

Emerging concepts in non-invasive monitoring of Crohn's disease

Inflammatory bowel disease (IBD) is an umbrella term for Crohn's disease (CD) and ulcerative colitis (UC). In light of evolving epidemiology of CD, its clinical management is still complex and remains a challenge for contemporary physicians. With the advent of new diagnostic and treatment paradigms, there is a growing need for new biomarkers to guide decision-making, differential diagnosis, disease activity monitoring, as well as prognosis. However, both clinical and endoscopic scoring systems, widely utilized for disease monitoring and prognosis, have drawbacks and limitations. In recent years, biochemical peptides have become available for IBD monitoring and more frequently used as surrogate markers of gut inflammation. Emerging concepts that revolve around molecular, stem cell, epigenetic, microbial or metabolomic pathways associated with vascular and epithelial gut barrier could lead to development of new CD biomarkers. Measurement of cell-derived microvesicles (MVs) in the blood of IBD patients is another emerging concept helpful in future disease management. In this review, we discuss novel concepts of non-invasive biomarkers, which may become useful in monitoring of CD activity and prognosis. We discuss metabolomics as a new powerful tool for clinicians to guide differential IBD diagnosis. In the coming years, new developments of prognostic tools are expected, aiming for breakthroughs in the management of patients with CD.

Cardiac Telocyte-Derived Exosomes and Their Possible Implications in Cardiovascular Pathophysiology

Among cardiac interstitial cells, the recently described telocytes (TCs) display the unique ability to build a supportive three-dimensional network formed by their very long and thin prolongations named telopodes. Cardiac TCs are increasingly regarded as pivotal regulators in intercellular signaling with multiple cell types, such as cardiomyocytes, stem/progenitor cells, microvessels, nerve endings, fibroblasts and immune cells, thus converting the cardiac stromal compartment into an integrated system that may drive either heart development or maintenance of cardiac homeostasis in post-natal life. Besides direct intercellular communications between TCs and neighboring cells, different types of TC-released extracellular vesicles (EVs), namely exosomes, ectosomes and multivesicular cargos, may act as shuttles for paracrine molecular signal exchange between cardiac TCs and cardiomyocytes or putative cardiomyocyte progenitors. In this review, we summarize the recent research findings on cardiac TCs and their EVs. We first provide an overview of the general features of TCs, including their peculiar morphological traits and immunophenotypes, intercellular signaling mechanisms and possible functional roles. Thereafter, we describe the distribution of TCs in normal and diseased hearts, as well as their role as intercellular communicators via the release of exosomes and other types of EVs. Finally, the involvement of cardiac TCs in cardiovascular diseases and the potential utility of TC transplantation and TC-derived exosomes in cardiac regeneration and repair are discussed.

Stem cells and their potential clinical applications in psychiatric disorders

The robustness of stem cells is one of the major factors that directly impacts life quality and life span. Evidence has accumulated that changes in the stem cell compartment affect human mental health and serve as an indicator of psychiatric problems. It is well known that stem cells continuously replace differentiated cells and tissues that are used up during life, although this replacement occurs at a different pace in the various organs. However, the participation of local neural stem cells in regeneration of the central nervous system is controversial. It is known that low numbers of stem cells circulate continuously in peripheral blood (PB) and lymph and undergo a circadian rhythm in their PB level, with the peak occurring early in the morning and the nadir at night, and recent evidence suggests that the number and pattern of circulating stem cells in PB changes in psychotic disorders. On the other hand, progress in the creation of induced pluripotent stem cells (iPSCs) from patient somatic cells provides valuable tools with which to study changes in gene expression in psychotic patients. We will discuss the various potential sources of stem cells that are currently employed in regenerative medicine and the mechanisms that explain some of their beneficial effects as well as the emerging problems with stem cell therapies. However, the main question remains: Will it be possible in the future to modulate the stem cell compartment to reverse psychiatric problems?

A new cellular type in invertebrates: first evidence of telocytes in leech Hirudo medicinalis

Telocytes, a peculiar cell type, were recently found in vertebrates. Hence this cell system has been reported as ubiquitous in the bodies of mammals and interpreted as an important player in innate immunity and tissue regeneration, it is reasonable to look for it also in invertebrates, that rely their integrity solely by innate immunity. Here we describe, at morphological and functional level, invertebrate telocytes from the body of leech Hirudo medicinalis (Annelida), suggesting how these cells, forming a resident stromal 3D network, can influence or participate in different events. These findings support the concepts that leech telocytes: i) are organized in a cellular dynamic and versatile 3D network likewise the vertebrate counterpart; ii) are an evolutionarily conserved immune-neuroendocrine system; iii) form an immuno-surveillance system of resident cells responding faster than migrating immunocytes recruited in stimulated area; iv) communicate with neighbouring cells directly and indirectly, via cell-cell contacts and soluble molecules secreted by multivesicular bodies; v) present within neo-vessels, share with immunocytes the mesodermal lineage; vi) are involved in regenerative processes. In conclusion, we propose that HmTCs, integrating so different functions, might explain the innate immune memory and can be associated with several aged related diseases.

Therapeutic roles of telocytes in OVA-induced acute asthma in mice

Telocytes (TCs) newly discovered as the mesenchyme-derived interstitial cells were found to have supportive effects on mesenchymal stem cells (MSCs). The present study aimed at investigating effects of TCs or TCs gathered with MSCs on experimental airway inflammation and hyper-responsiveness. The TCs were isolated from the lung tissue of the female BALB/c mice. The ovalbumin (OVA)-induced asthma model was established. TCs (1 × 10⁶ /2 × 10⁶ ) and/or MSCs (1 × 10⁶ ) were injected through mice tail vein for consecutive three days before OVA excited the mice. This study at first demonstrated that the transplantation of TCs could improve allergen-induced asthma by obviously inhibiting airway inflammation and airway hyper-responsiveness preclinically, with the down-regulation of Th2-related cytokine IL-4, transcription factor GATA-3 and Th2 cell differentiation, while up-regulation of Th1-related cytokine IFN-γ, transcription factor T-bet and Th1 cells proliferation in asthma, just like MSCs. Co-transplantation of TCs with MSCs showed better therapeutic effects on experimental asthma, even though the therapeutic effects of TCs alone were similar to those of MSCs alone. TCs and the combination of TCs with MSCs could improve the airway inflammation and airway hyper-responsiveness and can be a new alternative for asthma therapy.