Maternal immune activation leads to defective brain-blood vessels and intracerebral hemorrhages in male offspring.

Intracerebral hemorrhages are recognized risk factors for neurodevelopmental disorders and represent early biomarkers for cognitive dysfunction and mental disability, but the pathways leading to their occurrence are not well defined. We report that a single intrauterine exposure of the immunostimulant Poly I:C to pregnant mice at gestational day 9, which models a prenatal viral infection and the consequent maternal immune activation, induces the defective formation of brain vessels and causes intracerebral hemorrhagic events, specifically in male offspring. We demonstrate that maternal immune activation promotes the production of the TGF-ß1 active form and the consequent enhancement of pSMAD1-5 in males' brain endothelial cells. TGF-ß1, in combination with IL-1ß, reduces the endothelial expression of CD146 and claudin-5, alters the endothelium-pericyte interplay resulting in low pericyte coverage, and increases hemorrhagic events in the adult offspring. By showing that exposure to Poly I:C at the beginning of fetal cerebral angiogenesis results in sex-specific alterations of brain vessels, we provide a mechanistic framework for the association between intragravidic infections and anomalies of the neural vasculature, which may contribute to neuropsychiatric disorders.

Preclinical ImmunoPET Imaging Using a Zr-89-Labeled Anti-CD146 Monoclonal Antibody for Diagnosis of Melanoma.

The aim of this study was to evaluate the preclinical efficacy of [89Zr]Zr-DFO-Ab253 as a novel positron emission tomography (PET) tracer for CD146-positive malignant melanoma imaging. Considering the high expression of CD146 in malignant melanoma, this study investigated the effect of different CD146 expression levels on the tumor uptake of [89Zr]Zr-DFO-Ab253. CD146 selectivity was investigated by using the CD146-positive human melanoma cell A375 and the CD146-negative human alveolar epithelial cell A549. The cell uptake of [89Zr]Zr-DFO-Ab253 tracers was investigated, and receptor-binding affinities were measured by radioactive enzyme-linked immunosorbent assay. Biodistribution studies and micro-PET imaging of the radiotracers were performed on mice bearing A375 and A549 xenografts under baseline and blocking conditions. An immunohistochemical test was performed using A375 and A549 tissue sections for CD146 expression level analysis. [89Zr]Zr-DFO-Ab253 was obtained with a high radiochemical yield (87.86 ± 4.66%) and a satisfactory radiochemical purity (>98.0%). The specificity and affinity of [89Zr]Zr-DFO-Ab253 were confirmed in melanoma A375 cells and in vivo PET imaging of A375 tumor models. [89Zr]Zr-DFO-IgG and A549 lung tumors were prepared as control radiotracers and negative models to verify the specificity of [89Zr]Zr-DFO-Ab253 on CD146. [89Zr]Zr-DFO-Ab253 has a Kd of 4.01 ± 0.50 nM. PET imaging and biodistribution showed a higher uptake of [89Zr]Zr-DFO-Ab253 in A375 melanomas than that in A549 tumors (42.1 ± 4.04% vs 7.87 ± 1.30% ID/g at 120 h, P < 0.05). A low tumor uptake of [89Zr]Zr-DFO-IgG was observed with uptakes of 1.91 ± 0.41 and 2.80 ± 0.14 ID%/g when blocked at 120 h. The radiation-absorbed dose was calculated to be 0.13 mSv/MBq. This study demonstrates the synthesis and preclinical evaluation of [89Zr]Zr-DFO-Ab253 and indicates that the novel tracer has promising applications in malignant melanoma-specific PET imaging because of its high uptake and long-time retention in malignant melanoma. It also provides feasibility for the development of integrated molecular probes for diagnosis and treatment based on the CD146 target.

Specific lipid magnetic sphere sorted CD146-positive bone marrow mesenchymal stem cells can better promote articular cartilage damage repair.

BACKGROUND: The characteristics and therapeutic potential of subtypes of bone marrow mesenchymal stem cells (BMSCs) are largely unknown. Also, the application of subpopulations of BMSCs in cartilage regeneration remains poorly characterized. The aim of this study was to explore the regenerative capacity of CD146-positive subpopulations of BMSCs for repairing cartilage defects. METHODS: CD146-positive BMSCs (CD146 + BMSCs) were sorted by self-developed CD146-specific lipid magnetic spheres (CD146-LMS). Cell surface markers, viability, and proliferation were evaluated in vitro. CD146 + BMSCs were subjected to in vitro chondrogenic induction and evaluated for chondrogenic properties by detecting mRNA and protein expression. The role of the CD146 subpopulation of BMSCs in cartilage damage repair was assessed by injecting CD146 + BMSCs complexed with sodium alginate gel in the joints of a mouse cartilage defect model. RESULTS: The prepared CD146-LMS had an average particle size of 193.7 ± 5.24 nm, an average potential of 41.9 ± 6.21 mv, and a saturation magnetization intensity of 27.2 Am2/kg, which showed good stability and low cytotoxicity. The sorted CD146 + BMSCs highly expressed stem cell and pericyte markers with good cellular activity and cellular value-added capacity. Cartilage markers Sox9, Collagen II, and Aggrecan were expressed at both protein and mRNA levels in CD146 + BMSCs cells after chondrogenic induction in vitro. In a mouse cartilage injury model, CD146 + BMSCs showed better function in promoting the repair of articular cartilage injury. CONCLUSION: The prepared CD146-LMS was able to sort out CD146 + BMSCs efficiently, and the sorted subpopulation of CD146 + BMSCs had good chondrogenic differentiation potential, which could efficiently promote the repair of articular cartilage injury, suggesting that the sorted CD146 + BMSCs subpopulation is a promising seed cell for cartilage tissue engineering.

The Origin and Contribution of Cancer-Associated Fibroblasts in Colorectal Carcinogenesis.

BACKGROUND & AIMS: Cancer-associated fibroblasts (CAFs) play an important role in colorectal cancer (CRC) progression and predict poor prognosis in CRC patients. However, the cellular origins of CAFs remain unknown, making it challenging to therapeutically target these cells. Here, we aimed to identify the origins and contribution of colorectal CAFs associated with poor prognosis. METHODS: To elucidate CAF origins, we used a colitis-associated CRC mouse model in 5 different fate-mapping mouse lines with 5-bromodeoxyuridine dosing. RNA sequencing of fluorescence-activated cell sorting-purified CRC CAFs was performed to identify a potential therapeutic target in CAFs. To examine the prognostic significance of the stromal target, CRC patient RNA sequencing data and tissue microarray were used. CRC organoids were injected into the colons of knockout mice to assess the mechanism by which the stromal gene contributes to colorectal tumorigenesis. RESULTS: Our lineage-tracing studies revealed that in CRC, many ACTA2+ CAFs emerge through proliferation from intestinal pericryptal leptin receptor (Lepr)+ cells. These Lepr-lineage CAFs, in turn, express melanoma cell adhesion molecule (MCAM), a CRC stroma-specific marker that we identified with the use of RNA sequencing. High MCAM expression induced by transforming growth factor ß was inversely associated with patient survival in human CRC. In mice, stromal Mcam knockout attenuated orthotopically injected colorectal tumoroid growth and improved survival through decreased tumor-associated macrophage recruitment. Mechanistically, fibroblast MCAM interacted with interleukin-1 receptor 1 to augment nuclear factor κB-IL34/CCL8 signaling that promotes macrophage chemotaxis. CONCLUSIONS: In colorectal carcinogenesis, pericryptal Lepr-lineage cells proliferate to generate MCAM+ CAFs that shape the tumor-promoting immune microenvironment. Preventing the expansion/differentiation of Lepr-lineage CAFs or inhibiting MCAM activity could be effective therapeutic approaches for CRC.

A Direct-Contact Photocurrent-Direction-Switching Biosensing Platform Based on In Situ Formation of CN QDs/TiO2 Nanodiscs and Double-Supported 3D DNA Walking Amplification.

Herein, a direct-contact photocurrent-direction-switching photoelectrochemical (PEC) biosensing platform for the ultrasensitive and selective detection of soluble CD146 (sCD146) is reported for the first time via in situ formation of carbon nitride quantum dots (CN QDs)/titanium dioxide (TiO2 ) nanodiscs with the double-supported 3D DNA walking amplification. In this platform, metal organic frameworks (MOFs)-derived porous TiO2 nanodiscs exhibit excellent anodic photocurrent, whereas a single-stranded auxiliary DNA (ssDNA) as biogate is absorbed onto the TiO2 nanodiscs to block active sites. Subsequently, with the help of intermediate DNAs from target sCD146-induced double-supported 3D DNA walking signal amplification, the ssDNA can leave away from the surface of TiO2 nanodiscs due to the specific hybridization with intermediate DNAs. Afterward, the successful direct contact of CN QDs on TiO2 nanodiscs by porosity and electrostatic adsorption, leads to the effective photocurrent-direction switching from anodic to cathodic photocurrent. Based on direct-contact photocurrent-direction-switching CN QDs/TiO2 nanodiscs system and double-supported 3D DNA walking signal amplification, sCD146 is detected sensitively with a wide linear range (10 fg mL-1 to 5 ng mL-1 ) and a low limit of detection (2.1 fg mL-1 ). Also, the environmentally friendly and direct-contact photocurrent-direction-switching PEC biosensor has an application prospect for cancer biomarker detection.

CD146 deficiency promotes inflammatory type 2 responses in pulmonary cryptococcosis.

Cryptococcus neoformans (C. neoformans) is an important opportunistic fungal pathogen for pulmonary cryptococcosis. Previously, we demonstrated that CD146 mediated the adhesion of C. neoformans to the airway epithelium. CD146 is more than an adhesion molecule. In the present study, we aimed to explore the roles of CD146 in the inflammatory response in pulmonary cryptococcosis. CD146 was decreased in lung tissues from patients with pulmonary cryptococcosis. Similarly, C. neoformans reduced pulmonary CD146 expression in mice following intratracheal inoculation. To explore the pathological roles of CD146 reduction in pulmonary cryptococcosis, CD146 knockout (KO) mice were inoculated with C. neoformans via intratracheal instillation. CD146 deficiency aggravated C. neoformans infection, as evidenced by a shortened survival time and increased fungal burdens in the lung. Inflammatory type 2 cytokines (IL-4, IL-5, and TNF-α) and alternatively activated macrophages were increased in the pulmonary tissues of CD146 KO-infected mice. CD146 is expressed in immune cells (macrophages, etc.) and nonimmune cells, i.e., epithelial cells and endothelial cells. Bone marrow chimeric mice were established and infected with C. neoformans. CD146 deficiency in immune cells but not in nonimmune cells increased fungal burdens in the lung. Mechanistically, upon C. neoformans challenge, CD146 KO macrophages produced more neutrophil chemokine KC and inflammatory cytokine TNF-α. Meanwhile, CD146 KO macrophages decreased the fungicidity and production of reactive oxygen species. Collectively, C. neoformans infection decreased CD146 in pulmonary tissues, leading to inflammatory type 2 responses, while CD146 deficiency worsened pulmonary cryptococcosis.

Effect of CD146+ SHED on bone regeneration in a mouse calvaria defect model.

OBJECTIVE: Stem cells from human exfoliated deciduous teeth (SHED) have bone regeneration ability and potential therapeutic applications. CD146, a cell adhesion protein expressed by vascular endothelial cells, is involved in osteoblastic differentiation of stem cells. The effect of CD146 on SHED-mediated bone regeneration in vivo remains unknown. We aimed to establish efficient conditions for SHED transplantation. MATERIALS AND METHODS: SHED were isolated from the pulp of an extracted deciduous tooth and cultured; CD146-positive (CD146+ ) and CD146-negative (CD146- ) populations were sorted. Heterogeneous populations of SHED and CD146+ and CD146- cells were transplanted into bone defects generated in the skulls of immunodeficient mice. Micro-computed tomography was performed immediately and 4 and 8 weeks later. Histological and immunohistochemical assessments were performed 8 weeks later. RESULTS: Bone regeneration was observed upon transplantation with CD146+ and heterogeneous populations of SHED, with significantly higher bone regeneration observed with CD146+ cells. Bone regeneration was higher in the CD146- group than in the control group, but significantly lower than that in the other transplant groups at 4 and 8 weeks. Histological and immunohistochemical assessments revealed that CD146+ cells promoted bone regeneration and angiogenesis. CONCLUSION: Transplantation of CD146+ SHED into bone defects may be useful for bone regeneration.

Bone Differentiation Ability of CD146-Positive Stem Cells from Human Exfoliated Deciduous Teeth.

Regenerative therapy for tissues by mesenchymal stem cell (MSCs) transplantation has received much attention. The cluster of differentiation (CD)146 marker, a surface-antigen of stem cells, is crucial for angiogenic and osseous differentiation abilities. Bone regeneration is accelerated by the transplantation of CD146-positive deciduous dental pulp-derived mesenchymal stem cells contained in stem cells from human exfoliated deciduous teeth (SHED) into a living donor. However, the role of CD146 in SHED remains unclear. This study aimed to compare the effects of CD146 on cell proliferative and substrate metabolic abilities in a population of SHED. SHED was isolated from deciduous teeth, and flow cytometry was used to analyze the expression of MSCs markers. Cell sorting was performed to recover the CD146-positive cell population (CD146+) and CD146-negative cell population (CD146-). CD146 + SHED without cell sorting and CD146-SHED were examined and compared among three groups. To investigate the effect of CD146 on cell proliferation ability, an analysis of cell proliferation ability was performed using BrdU assay and MTS assay. The bone differentiation ability was evaluated using an alkaline phosphatase (ALP) stain after inducing bone differentiation, and the quality of ALP protein expressed was examined. We also performed Alizarin red staining and evaluated the calcified deposits. The gene expression of ALP, bone morphogenetic protein-2 (BMP-2), and osteocalcin (OCN) was analyzed using a real-time polymerase chain reaction. There was no significant difference in cell proliferation among the three groups. The expression of ALP stain, Alizarin red stain, ALP, BMP-2, and OCN was the highest in the CD146+ group. CD146 + SHED had higher osteogenic differentiation potential compared with SHED and CD146-SHED. CD146 contained in SHED may be a valuable population of cells for bone regeneration therapy.

Proteomics and Biochemical Analyses of Secreted Proteins Revealed a Novel Mechanism by Which ADAM12S Regulates the Migration of Gastric Cancer Cells.

Gastric cancer is one of the cancers with the highest morbidity and mortality. Although several therapeutic approaches have been developed to treat this disease, the overall survival rate is still very low due to metastasis, drug resistance, and so forth. Therefore, it is necessary to discover new regulatory molecules and signaling pathways that modulate the metastasis of gastric cancer cells. A Disintegrin And Metalloprotease 12 (ADAM12) was highly expressed in gastric cancer tissues and presented in the patient urine. However, it is unclear whether and how ADAM12 regulates the migration of gastric cancer cells. In this work, we used the secretome protein enrichment with click sugars (SPECS) method to purify the secreted glycosylated proteins and performed quantitative proteomics to identify the secreted proteins that were differentially regulated by ADAM12S, the short and secreted form of ADAM12. Our proteomic and biochemical analyses revealed that ADAM12S upregulated the cell surface glycoprotein CD146, a cell adhesion molecule and melanoma marker, which was dependent on the catalytic residue of ADAM12S. Furthermore, we discovered that the ADAM12S-enhanced migration of gastric cancer cells was, at least partially, mediated by CD146. This work may help to evaluate whether ADAM12 could be a potential therapeutic target for the treatment of gastric cancer patients.

Influence of age on stem cells depends on the sex of the bone marrow donor.

Ageing is often accompanied by an increase in bone marrow fat together with reduced bone volume and diseases of the bone such as osteoporosis. As mesenchymal stem cells (MSCs) are capable of forming bone, cartilage and fat tissue, studying these cells is of great importance to understand the underlying mechanisms behind age-related bone diseases. However, inter-donor variation has been found when handling MSCs. Therefore, the aim of this study was to investigate the effects of donor age and sex by comparing in vitro characteristics of human bone marrow-derived MSCs (hBMSCs) from a large donor cohort (n = 175). For this, hBMSCs were analysed for CFU-F capacity, proliferation, differentiation capacity and surface antigen expression under standardized culture conditions. The results demonstrated a significantly reduced CFU-F number for hBMSCs of female compared to male donors. Furthermore, there was a significant decrease in the proliferation rate, adipogenic differentiation potential and cell surface expression of SSEA-4, CD146 and CD274 of hBMSCs with an increase in donor age. Interestingly, all these findings were exclusive to hBMSCs from female donors. Further research should focus on postmenopausal-related effects on hBMSCs, as the results imply a functional loss and immunophenotypic change of hBMSCs particularly in aged women.

CD146 expression regulates osteochondrogenic differentiation of human adipose-derived stem cells.

Tissue engineering aims to develop innovative approaches to repair tissue defects. The use of adipose-derived stem cells (ASCs) in tissue regeneration was extensively investigated for osteochondrogenesis. Among the ASC population, ASCs expressing the CD146 were demonstrated to be multipotent and considered as perivascular stem cells, although the functional role of CD146 expression in these cells remains unclear. Herein, we investigated the influence of CD146 expression on osteochondrogenic differentiation of ASCs. Our results showed that, in two-dimensional culture systems, sorted CD146+ ASCs proliferated less and displayed higher adipogenic and chondrogenic potential than CD146- ASCs. The latter demonstrated a higher osteogenic capacity. Besides this, CD146+ ASCs in three-dimensional Matrigel/endothelial growth medium (EGM) cultures showed the highest angiogenic capability. When cultured in three-dimensional collagen scaffolds, CD146+ ASCs showed a spontaneous chondrogenic differentiation, further enhanced by the EGM medium's addition. Finally, CD146- ASCs seeded on hexafluoroisopropanol silk scaffolds displayed a greater spontaneous osteogenetic capacity. Altogether, these findings demonstrated a functional and relevant influence of CD146 expression in ASC properties and osteochondrogenic commitment. Exploiting the combination of specific differentiation properties of ASC subpopulations and appropriate culture systems could represent a promising strategy to improve the efficacy of new regenerative therapies.

MCAM abnormal expression and clinical outcome associations are highly cancer dependent as revealed through pan-cancer analysis.

MCAM (CD146) is a cell surface adhesion molecule that has been reported to promote cancer development, progression and metastasis and is considered as a potential tumor biomarker and therapeutic target. However, inconsistent reports exist, and its clinical value is yet to be confirmed. Here we took advantage of several large genomic data collections (Genotype-Tissue Expression, The Cancer Genome Atlas and Cancer Cell Line Encyclopedia) and comprehensively analyzed MCAM expression in thousands of normal and cancer samples and cell lines along with their clinical phenotypes and drug response information. Our results show that MCAM is very highly expressed in large vessel tissues while majority of tissues have low or minimal expression. Its expression is dramatically increased in a few tumors but significantly decreased in most other tumors relative to their pairing normal tissues. Increased MCAM expression is associated with a higher tumor stage and worse patient survival for some less common tumors but not for major ones. Higher MCAM expression in primary tumors may be complicated by tumor-associated or normal stromal blood vessels yet its significance may differ from the one from cancer cells. MCAM expression is weakly associated with the response to a few small molecular drugs and the association with targeted anti-BRAF agents suggests its involvement in that pathway which warrants further investigation.

Single-cell RNA sequencing redefines the mesenchymal cell landscape of mouse endometrium.

The endometrium is a dynamic tissue that exhibits remarkable resilience to repeated episodes of differentiation, breakdown, regeneration, and remodeling. Endometrial physiology relies on a complex interplay between the stromal and epithelial compartments with the former containing a mixture of fibroblasts, vascular, and immune cells. There is evidence for rare populations of putative mesenchymal progenitor cells located in the perivascular niche of human endometrium, but the existence of an equivalent cell population in mouse is unclear. We used the Pdgfrb-BAC-eGFP transgenic reporter mouse in combination with bulk and single-cell RNA sequencing to redefine the endometrial mesenchyme. In contrast to previous reports we show that CD146 is expressed in both PDGFRß + perivascular cells and CD31 + endothelial cells. Bulk RNAseq revealed cells in the perivascular niche which express the high levels of Pdgfrb as well as genes previously identified in pericytes and/or vascular smooth muscle cells (Acta2, Myh11, Olfr78, Cspg4, Rgs4, Rgs5, Kcnj8, and Abcc9). scRNA-seq identified five subpopulations of cells including closely related pericytes/vascular smooth muscle cells and three subpopulations of fibroblasts. All three fibroblast populations were PDGFRα+/CD34 + but were distinct in their expression of Ngfr/Spon2/Angptl7 (F1), Cxcl14/Smoc2/Rgs2 (F2), and Clec3b/Col14a1/Mmp3 (F3), with potential functions in the regulation of immune responses, response to wounding, and organization of extracellular matrix, respectively. Immunohistochemistry was used to investigate the spatial distribution of these populations revealing F1/NGFR + cells in most abundance beside epithelial cells. We provide the first definitive analysis of mesenchymal cells in the adult mouse endometrium identifying five subpopulations providing a platform for comparisons between mesenchymal cells in endometrium and other adult tissues which are prone to fibrosis.

Histochemical localization of putative stem cells in irreversible pulpitis.

OBJECTIVES: Our study aimed to observe the distribution of putative stem cells in irreversible pulpitis and to investigate the expression of specific molecules. SUBJECTS AND METHODS: Extracted third molar teeth were collected and divided into two groups: the normal pulp group and inflamed pulp group. Real-time PCR was applied to detect the expression of several embryonic and dentinogenic genes. The expression of mesenchymal cell markers (STRO-1, CD90, and CD146) and stromal cell-derived factor 1α (SDF-1α)/CXC chemokine receptor 4 (CXCR4) proteins was examined by immunohistochemical analysis. RESULTS: The expression levels of most embryonic and dentinogenic genes were not statistically different between the two groups. Immunohistochemical analysis revealed that in inflamed pulp, cells with positive expression for STRO-1, CD90, and CD146 mainly resided in two specific niches, both adjacent to inflammatory sites: one in the pulp core and another in the odontoblast layer. SDF-1α- and CXCR4-positive cells were significantly correlated with STRO-1-positive cells. Double immunofluorescence analysis indicated that STRO-1-positive cells overlapped with SDF-1α- and CXCR4-positive cells near the inflammatory site. CONCLUSIONS: This study gave a direct observation of putative stem cells distributed in irreversible pulpitis and implied a role of SDF-1α/CXCR4 signaling in stem cell-based therapies for reparative dentinogenesis.

Soluble CD146 as a Potential Target for Preventing Triple Negative Breast Cancer MDA-MB-231 Cell Growth and Dissemination.

Background: Triple Negative Breast Cancers (TNBC) are the most aggressive breast cancers and lead to poor prognoses. This is due to a high resistance to therapies, mainly because of the presence of Cancer Stem Cells (CSCs). Plasticity, a feature of CSCs, is acquired through the Epithelial to Mesenchymal Transition (EMT), a process that has been recently shown to be regulated by a key molecule, CD146. Of interest, CD146 is over-expressed in TNBC. Methods: The MDA-MB-231 TNBC cell line was used as a model to study the role of CD146 and its secreted soluble form (sCD146) in the development and dissemination of TNBC using in vitro and in vivo studies. Results: High expression of CD146 in a majority of MDA-MB-231 cells leads to an increased secretion of sCD146 that up-regulates the expression of EMT and CSC markers on the cells. These effects can be blocked with a specific anti-sCD146 antibody, M2J-1 mAb. M2J-1 mAb was able to reduce tumour development and dissemination in a model of cells xenografted in nude mice and an experimental model of metastasis, respectively, in part through its effects on CSC. Conclusion: We propose that M2J-1 mAb could be used as an additional therapeutic approach to fight TNBC.

Immature Vascular Smooth Muscle Cells in Healthy Murine Arteries and Atherosclerotic Plaques: Localization and Activity.

The local development of atherosclerotic lesions may, at least partly, be associated with the specific cellular composition of atherosclerosis-prone regions. Previously, it was demonstrated that a small population of immature vascular smooth muscle cells (VSMCs) expressing both CD146 and neuron-glial antigen 2 is postnatally sustained in atherosclerosis-prone sites. We supposed that these cells may be involved in atherogenesis and can continuously respond to angiotensin II, which is an atherogenic factor. Using immunohistochemistry, flow cytometry, wound migration assay xCELLigence system, and calcium imaging, we studied the functional activities of immature VSMCs in vitro and in vivo. According to our data, these cells do not express nestin, CD105, and the leptin receptor. They are localized in atherosclerosis-prone regions, and their number increases with age, from 5.7% to 23%. Immature VSMCs do not migrate to low shear stress areas and atherosclerotic lesions. They also do not have any unique response to angiotensin II. Thus, despite the localization of immature VSMCs and the presence of the link between their number and age, our study did not support the hypothesis that immature VSMCs are directly involved in the formation of atherosclerotic lesions. Additional lineage tracing studies can clarify the fate of these cells during atherogenesis.

CD200 as a Potential New Player in Inflammation during Rotator Cuff Tendon Injury/Repair: An In Vitro Model.

Rotator cuff tendon (RCT) disease results from multifactorial mechanisms, in which inflammation plays a key role. Pro-inflammatory cytokines and tendon stem cell/progenitor cells (TSPCs) have been shown to participate in the inflammatory response. However, the underlying molecular mechanism is still not clear. In this study, flow cytometry analyses of different subpopulations of RCT-derived TSPCs demonstrate that after three days of administration, TNFα alone or in combination with IFNγ significantly decreases the percentage of CD146+CD49d+ and CD146+CD49f+ but not CD146+CD109+ TSPCs populations. In parallel, the same pro-inflammatory cytokines upregulate the expression of CD200 in the CD146+ TSPCs population. Additionally, the TNFα/IFNγ combination modulates the protein expression of STAT1, STAT3, and MMP9, but not fibromodulin. At the gene level, IRF1, CAAT (CAAT/EBPbeta), and DOK2 but not NF-κb, TGRF2 (TGFBR2), and RAS-GAP are modulated. In conclusion, although our study has several important limitations, the results highlight a new potential role of CD200 in regulating inflammation during tendon injuries. In addition, the genes analyzed here might be new potential players in the inflammatory response of TSPCs.

CD146 is a potential immunotarget for neuroblastoma.

Neuroblastoma, the most common extracranial solid tumor of childhood, is thought to arise from neural crest-derived immature cells. The prognosis of patients with high-risk or recurrent/refractory neuroblastoma remains quite poor despite intensive multimodality therapy; therefore, novel therapeutic interventions are required. We examined the expression of a cell adhesion molecule CD146 (melanoma cell adhesion molecule [MCAM]) by neuroblastoma cell lines and in clinical samples and investigated the anti-tumor effects of CD146-targeting treatment for neuroblastoma cells both in vitro and in vivo. CD146 is expressed by 4 cell lines and by most of primary tumors at any stage. Short hairpin RNA-mediated knockdown of CD146, or treatment with an anti-CD146 polyclonal antibody, effectively inhibited growth of neuroblastoma cells both in vitro and in vivo, principally due to increased apoptosis via the focal adhesion kinase and/or nuclear factor-kappa B signaling pathway. Furthermore, the anti-CD146 polyclonal antibody markedly inhibited tumor growth in immunodeficient mice inoculated with primary neuroblastoma cells. In conclusion, CD146 represents a promising therapeutic target for neuroblastoma.

Soluble CD146-an underreported novel biomarker of congestion: a comment on a review concerning congestion assessment and evaluation in acute heart failure.

In spite of high prevalence, congestion remains a poorly understood phenomenon in heart failure pathophysiology. Its negative impact on outcome has been widely recognised. Still, data from various registries reveal the failure of the contemporary treatment strategies to overcome congestion. This shortcoming is closely related to the fact that there are no universe means for congestion assessment and grading, making it a difficult process to recognise. CD146 is a novel blood biomarker of congestion that has been shown to reflect intravascular fluid accumulation in a number of experimental and clinical studies. This observation deserves special attention, given the huge gap of knowledge about decongestive strategies in acute and chronic heart failure. Randomised clinical trials testing the effect of CD146-guided management intervention are urgently needed to estimate its value in heart failure care.

Human endometrial perivascular stem cells exhibit a limited potential to regenerate endometrium after xenotransplantation.

STUDY QUESTION: What are the localization, characteristics and potential for tissue regeneration of two perivascular stem cells, namely CD34+ adventitial cells and CD146+ pericytes, in human endometrium? SUMMARY ANSWER: Human endometrial CD34+ adventitial cells (located in the outermost layer of blood vessels and mainly in the basal layer) and CD146+ pericytes showed mesenchymal stem cell (MSC) phenotypes in in vitro culture, but presented limited potential to regenerate endometrium. WHAT IS KNOWN ALREADY: Periodic endometrial regeneration is considered to be maintained by MSCs. Blood vessel wall, regarded as stem cell niche, harbors a large reserve of progenitor cells that may be integral to the origin of MSCs. However, a lack of validated markers has hampered the isolation of putative endometrial MSCs. Currently, CD146+ pericytes and Sushi Domain Containing 2 (SUSD2) positive cells have been identified in the endometrial perivascular region as sharing MSCs characteristics. STUDY DESIGN, SIZE, DURATION: The locations of adventitial cells and pericytes in the human endometrium were identified by immunofluorescence staining (n = 4). After CD34+CD146-CD45-CD56-CD144- adventitial cells and CD146+CD34-CD45-CD56-CD144- pericytes were isolated from the endometrium of normal women (n = 6) by fluorescence-activated cell sorting, their characteristics were investigated in culture. Adventitial cells and pericytes were induced to differentiate, respectively, into vascular endothelial-like cells or endometrial stromal-like cells in vitro, with their potential explored by in vivo xenotransplantation (n = 2 in each group) and eutopic transplantation (n = 2 in each group). PARTICIPANTS/MATERIALS, SETTING, METHODS: CD34+ adventitial cells and CD146+ pericytes were cultured in the inducing medium to differentiate into endothelial-like cells in vitro, and then analyzed for CD31, von Willebrand factor immunofluorescent staining and tube formation. They were also cultured to differentiate into endometrial stromal cells in vitro, with the expression of vimentin and CD13 being detected by western blot before and after induction, and the expression of prolactin and insulin-like growth factor-binding protein 1 being determined as well. Single dispersed CD34+ adventitial cells and CD146+ pericytes were respectively transplanted under the kidney capsule of NOG mice to investigate their differentiation potential in vivo. A eutopic transplantation model was constructed by grafting recellularized uterine matrix loaded up with CM-Dil labeled adventitial cells or pericytes into the injury region of nude rat's uterus. MAIN RESULTS AND THE ROLE OF CHANCE: CD34+ adventitial cells were mainly located at the outmost layer of endometrial large vessels, while CD146+ pericytes were found surrounding the inner endothelial cells of microvessels. A small proportion of CD34+ adventitial cells expressed SUSD2. The number of adventitial cells was ∼40 times higher than that of pericytes in the endometrium. Both adventitial cells and pericytes showed MSC phenotypes after in vitro culture. After in vitro induction into endometrial endothelial-like cells and stromal-like cells, adventitial cells showed higher plasticity than pericytes and a closer correlation with stromal-like cells. In the mouse xenotransplantation model, vimentin+ cells, CD31+ endothelial-like cells and CD146+ pericyte-like cells could be observed after adventitial cells were transplanted. CM-Dil-labeled adventitial cells or pericytes could survive in the immunocompromised nude rats after eutopic transplantation, and vimentin+ cells were detected. In addition, CM-Dil-labeled adventitial cells or pericytes did not express α-smooth muscle actin or E-cadherin after transplantation. LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: CD34 was chosen as a novel marker to isolate adventitial cells from human endometrium according to previous literature. The association of endometrial CD34+ adventitial cells and SUSD2+ MSCs should be further investigated. WIDER IMPLICATIONS OF THE FINDINGS: The decellularized uterine matrix model might be useful in endometrial stem cell therapy. STUDY FUNDING/COMPETING INTEREST(S): L.D. is supported by grants from National Key Research and Development Program of China (2018YFC1004700), Nature Science Foundation of China (81871128, 81571391) and Nanjing Medical Science Development Project (ZKX16042). H.S. is supported by a grant from Jiangsu Province Social Development Project (BE2018602). X.Z. was supported by grants from the Postgraduate Innovative Project of Jiangsu Province (KYCX19-1177). The authors declare no conflict of interest.