Surface Lin28A expression consistent with cellular stress parallels indicators of senescence

AIMS

Declining cellular functional capacity resulting from stress or ageing is a primary contributor to impairment of myocardial performance. Molecular pathway regulation of biological processes in cardiac interstitial cells (CICs) is pivotal in stress and ageing responses. Altered localization of the RNA-binding protein Lin28A has been reported in response to environmental stress, but the role of Lin28A in response to stress in CICs has not been explored. Surface Lin28A redistribution is indicative of stress response in CIC associated with ageing and senescence.

METHODS AND RESULTS

Localization of Lin28A was assessed by multiple experimental analyses and treatment conditions and correlated to oxidative stress, senescence, and ploidy in adult murine CICs. Surface Lin28A expression is present on 5% of fresh CICs and maintained through Passage 2, increasing to 21% in hyperoxic conditions but lowered to 14% in physiologic normoxia. Surface Lin28A is coincident with elevated senescence marker p16 and beta-galactosidase (β-gal) expression in CICs expanded in hyperoxia, and also increases with polyploidization and binucleation of CICs regardless of oxygen culture. Transcriptional profiling of CICs using single-cell RNA-Seq reveals up-regulation of pathways associated with oxidative stress in CICs exhibiting surface Lin28A. Induction of surface Lin28A by oxidative stress is blunted by treatment of cells with the antioxidant Trolox in a dose-dependent manner, with 300 μM Trolox exposure maintaining characteristics of freshly isolated CICs possessing low expression of surface Lin28A and β-gal with predominantly diploid content.

CONCLUSION

Surface Lin28A is a marker of environmental oxidative stress in CICs and antioxidant treatment antagonizes this phenotype. The biological significance of Lin28 surface expression and consequences for myocardial responses may provide important insights regarding mitigation of cardiac stress and ageing.

Targeted surface marker screening on neuronal structures in the human choroid

While choroidal neuronal control is known to be essential for retinal and ocular health, its mechanisms are not understood. Especially, the local choroidal innervation mediated by intrinsic choroidal neurons (ICN) remains enigmatic. Neuronal functionality depends on the synaptic neurotransmitters and neuroregulatory peptides involved as well as from membrane components presented on the cell surface. Since the neuronal surface molecular expression patterns in the choroid are currently unknown, we sought to determine the presence of various cluster-of-differentiation (CD) antigens in choroidal neuronal structures with a particular focus on ICN. Human choroids were prepared for immunohistochemistry and the pan-neuronal marker PGP9.5 was combined with CD15, CD24, CD29, CD34, CD46, CD49b, CD49e, CD56, CD58, CD59, CD71, CD81, CD90, CD146, CD147, CD151, CD165, CD171, CD184, CD200, CD271 and fluorescence- and confocal laser scanning-microscopy was used for documentation. The following antigens were found to be co-localized in PGP.9.5+ nerve fibers and ICN perikarya: CD29, CD34, CD56, CD81, CD90, CD146, CD147, CD151, CD171, CD200 and CD271, while all other CD markers where not detectable. Whereas CD24^- and CD59^- immunoreactivity was clearly absent in ICN perikarya, some neural processes of the choroidal stroma displayed CD24 and CD59 immunopositivity. While a multitude of the aforementioned CD-markers were indeed detected in nervous structures of the choroid, the CD24⁺ and CD59⁺ nerve fibers most likely have extrinsic origin from cranial ganglia since ICN cell bodies were found to lack both markers. These findings illustrate how the detailed analysis of CD molecules described here opens novel avenues for future functional studies on choroidal innervation and its control.

Study of the biological characteristics of human umbilical cord mesenchymal stem cells after long-time cryopreservation

Human umbilical cord mesenchymal stem cells (hUC-MSCs) have considerable potential in cell therapy. Cryopreservation represents the gold standard in cell storage, but its effect on hUC-MSCs is still not well understood. The aim of this study was to investigate the effect of one year of cryopreservation and thawing on the biological characteristics of hUC-MSCs from the same donors. Fresh hUC-MSCs were cryopreserved in commercial freezing medium (serum-free CellBanker 2) at passage 2. After one year of cryopreservation, the hUC-MSCs were thawed and subcultured to passage 4. The comparison was performed in terms of followings: cell count, viability, morphology, proliferation capacity, differentiation potential and chromosomal stability. The total cell count and viability of hUC-MSCs before and after one year of cryopreservation were 1 × 107 and 96.34% and 0.943 × 107 and 93.81%, respectively. Cryopreserved and fresh hUC-MSCs displayed a similar cell doubling times, expressed the markers CD73, CD90, CD105 and were negative for the markers CD34, CD45, and HLA-DR. Karyotypes were found to be normal after one year of cryopreservation. The trilineage differentiation properties were maintained after cryopreservation. However, when compared to freshly isolated hUC-MSCs from the same donor, cryopreserved hUC-MSCs exhibited decreased expression of osteogenesis- and chondrogenesis-related genes including Runx2, Sox9, and Col1a1, and increased expression of adipogenesis-related genes. These results demonstrated that cryopreservation did not affect cell morphology, surface marker expression, cell viability, proliferative capacity, or chromosomal stability. However, the osteogenic and chondrogenic differentiation capacities of cryopreserved hUC-MSCs were slightly reduced compared with those of fresh cells from the same donor.

Cluster of differentiation antigens: essential roles in the identification of teleost fish T lymphocytes

Cluster of differentiation (CD) antigens are cell surface molecules expressed on leukocytes and other cells associated with the immune system. Antibodies that react with CD antigens are known to be one of the most essential tools for identifying leukocyte subpopulations. T lymphocytes, as an important population of leukocytes, play essential roles in the adaptive immune system. Many of the CD antigens expressed on T lymphocytes are used as surface markers for T lymphocyte classification, including CD3, CD4 and CD8 molecules. In this review, we summarize the recent advances in the identification of CD molecules on T lymphocytes in teleosts, with emphasis on the functions of CD markers in the classification of T lymphocyte subsets. We notice that genes encoding CD3, co-receptors CD4 and CD8 have been cloned in several fish species and antibodies have been developed to study protein expression in morphological and functional contexts. T lymphocytes can be divided into CD4⁺ and CD8⁺ cells discriminated by the expression of CD4 and CD8 molecules in teleost, which are functionally similar to mammalian helper T cells (Th) and cytotoxic T cells (Tc), respectively. Further studies are still needed on the particular characteristics of teleost T cell repertoires and adaptive responses, and results will facilitate the health management and development of vaccines for fish.

Fine synthesis of Prussian-blue analogue coated gold nanoparticles (Au@PBA NPs) for sorting specific cancer cell subtypes

Multiplex surface-enhanced Raman scattering (SERS) detection of markers without background in tumor biosystems has its superiority over other optical methods. Herein, we reported a strategy of quantitative discrimination of two breast cancer cell subtypes. Based on our previous studies, two kinds of Prussian blue analogue coated gold nanoparticles (Au@PBA NPs) were designed and synthesized by the replacement of Fe²⁺ with Pb²⁺ or Cu²⁺. Therefore, two distinct SERS emissions of C≡N bonds at 2122 cm^-1 and 2176 cm^-1 have been acquired. When modified with aptamers of epithelial cell adhesion molecule (EpCAM) and epidermal growth factor receptor (EGFR), which are both expressed in MCF-7 and MDA-MB-231 cell lines but in different levels, the SERS nanoprobes simultaneously identified the relative expression of these biomarkers on the cell surface, providing a good example for ratiometric detection in biosystems without any interference. Each surface marker of tumor cells corresponds to a single SERS emission. Thus, each subtype could be described in a molecular profiling way through duplex C≡N bonds-based SERS emission, which is more advanced than traditional flow cytometry method.

Fibroblast-like synoviocytes in rheumatoid arthritis: Surface markers and phenotypes

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease that mainly affects synovial joints. During the course of RA, the synovium transforms into hyperplastic invasive tissue, leading to cartilage and bone destruction. Fibroblast-like synoviocytes (FLS) in the synovial lining develop aggressive phenotypes and produce pathogenic mediators that lead to the occurrence and progression of disease, playing a major role in RA pathophysiology. Therefore, research on FLS has become the main focus within the RA field. With technical advances and the development of multi-omics comprehensive analysis approaches, it has become possible to identify different FLS subsets via high-throughput sequencing and investigate differences between FLS phenotypes, allowing for the detailed study of RA pathogenesis. This review summarizes recent works on FLS subtypes and the surface marker proteins identified for different subtypes, providing a theoretical basis and reference for future studies on FLS in RA. The current work also addresses the clinical potential of FLS surface markers in RA based on related research from other fields.

The clinical significance of CD49e and CD56 for multiple myeloma in the novel agents era

Multiple myeloma (MM) is a hematological malignancy characterized by the proliferation of abnormal plasma cells in bone marrow. Flow cytometry distinguishes between normal and abnormal plasma cells by evaluating cluster of differentiation (CD) 56 and CD19 expression patterns. Moreover, immunophenotyping of mature plasma cell 1 (MPC-1) and very late antigen-5 (CD49e) identifies the maturity of MM as mature (MPC-1⁺, CD49e⁺), intermediate (MPC-1⁺, CD49e^-), or immature (MPC-1^-, CD49e^-). We retrospectively examined the effects of surface marker expression and maturity subtype on overall survival (OS) and time to next treatment (TNT) among 55 patients (25 males, 30 females) with symptomatic MM. All patients were treated with regimens containing bortezomib (BOR) (n = 39) or lenalidomide (LEN) (n = 16) as the initial treatment. Median age at diagnosis was 72 years (range: 36-88). The lack of CD56, an aberrant marker, was associated with significantly worse prognosis compared with CD56⁺ MM (median OS: 24 vs. 60 months, respectively; p = 0.0050). In CD49e⁺ MM, defined as mature type, no significant difference was seen in TNT of the initial treatment, regardless of whether it was a BOR-based regimen or LEN + dexamethasone (Ld) therapy. On the other hand, in CD49e^- MM, defined as immature/intermediate type, TNT of Ld therapy was significantly longer than that of BOR-based regimens (median TNT: undefined vs. 12 months, respectively; p = 0.0043). These results suggest that Ld therapy is more effective than BOR-based therapy for CD49e^- MM and thus may aid regimen-related decisions in the novel agents era.

Early decrease in intermediate monocytes in peripheral blood is characteristic of multiple system atrophy-cerebellar type

To identify biomarkers for multiple system atrophy-cerebellar type (MSA-C), we used flow cytometry to measure surface marker expression of peripheral blood monocytes from patients with MSA-C or hereditary spinocerebellar degeneration (hSCD) and from healthy controls (HCs). The percentage of intermediate monocytes was significantly lower in MSA-C patients than in hSCD patients and HCs and showed significant positive correlations with disease duration and unified MSA rating scale scores. The percentage of CD62L⁺ intermediate monocytes was significantly lower in MSA-C patients than in hSCD patients and HCs. Early decrease of peripheral blood intermediate monocytes is characteristic of MSA-C and is a biomarker.

Lactobacillus johnsonii-activated chicken bone marrow-derived dendritic cells exhibit maturation and increased expression of cytokines and chemokines in vitro

Lactobacillus species are typical members of gut microflora that immunomodulatory effects and can regulate a variety of immune cells, such as dendritic cells (DCs). Notably, DCs possess the unique ability to initiate primary immune responses. Notably, DCs possess the unique ability to initiate primary immune responses. In this study, we investigated the effects of Lactobacillus johnsonii (L. johnsonii) on the maturation and activation of chicken bone marrow-derived dendritic cells (chBM-DCs). The chBM-DCs generated from chicken bone marrow monocytes were stimulated using lethally irradiated L. johnsonii. L. johnsonii-stimulated chBM-DCs upregulated the expression of major histocompatibility complex class II (MHC-II), CD40, and CD86, decreased phagocytosis, and increased the ability to induce the proliferation of allogeneic T cells, which displayed a mature phenotype and function. Upon maturation with L. johnsonii, the expression of Th1-type cytokines [interleukin (IL)-12, interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α)], a Th2-type cytokine (IL-10), pro-inflammatory cytokines (IL-1β and IL-6), and chemokines (CXCLi1 and CXCLi2) greatly increased; however, a high expression of IL-10 was only observed at mid-late time points for chBM-DCs stimulated with high doses of L. johnsonii. Moreover, L. johnsonii upregulated the mRNA levels of TLR2 and TLR5. These results reveal that L. johnsonii plays a potentially important role in modulating the immunological functions of chBM-DCs, suggesting that it influences and mediates immune responses in vitro.

Patients with systemic lupus erythematosus show increased proportions of CD19+CD20- B cells and secretion of related autoantibodies

BACKGROUND

At present, anti-CD20 monoclonal antibody treatments targeting systemic lupus erythematosus (SLE) are complex, variable, and often have disappointing outcomes. High levels of programmed cell death-1 (PD-1) and its ligands (PD-L1, PD-L2) or CD80/CD86 on B cell surfaces are markers of increased B cell activity. However, their expression levels on CD19⁺CD20^+/- B cells and their clinical significance for SLE dynamics have not been carefully investigated.

METHODS

Flow cytometry was used to detect the expression levels of PD-1, PD-L1, PD-L2, CD80, and CD86 on CD19⁺CD20^+/- B cells in peripheral blood from SLE patients and healthy controls (HCs). The amount of anti-dsDNA and immunoglobin G (IgG) secreted by CD19⁺CD20^+/- B cells was measured by enzyme-linked immunosorbent assay.

RESULTS

CD19⁺CD20^- B cell frequency was significantly higher in SLE patients than in HCs (P < 0.001), and was positively correlated with disease activity. In SLE patients, frequencies of PD-1, PD-L1, PD-L2, and CD86 on CD19⁺CD20^- B cells were significantly higher than CD19⁺CD20⁺ B cells (P ≤ 0.002) and were significantly correlated with individual laboratory and clinically based parameters (P < 0.05). In vitro tests, we found that the levels of anti-dsDNA and IgG secreted by CD19⁺CD20^- B cells from patients with SLE were significantly higher than the HC group (P < 0.05).

CONCLUSIONS

We found abnormal frequency of CD19⁺CD20^- B cells and increased expression of surface markers on these cells from SLE patients. And the CD19⁺CD20^- B cells had the ability to proliferate and secrete anti-dsDNA and IgG. Additionally, our results suggested that CD19⁺CD20^- B cells from SLE patients may be the activated B cells and caused poor efficacy of rituximab. Key Points • CD19⁺CD20^- B cell frequencies were significantly higher in SLE patients. • Frequencies of PD-1 and its ligands on CD19⁺CD20^- B cells increased significantly in SLE patients. • CD19⁺CD20^- B cells in SLE patients had the ability to secrete anti-dsDNA and IgG. • CD19⁺CD20^- B cells in SLE patients may be the activated B cells and caused poor efficacy of rituximab.

Multinucleated giant cell phenotype in response to stimulation

Macrophages fuse into multinucleated giant cells (MGC) in many pathological conditions. Despite MGC correlations with granulomas, their functional contribution to inflammation is relatively unknown. An in vitro mouse model of IL-4-induced bone marrow-derived macrophage fusion and microfiltration were used to generate enriched MGC and macrophage populations. Phenotypes were compared in response to well-known inflammatory stimuli, including lipopolysaccharide and crocidolite asbestos. Surface markers were assessed by flow cytometry: CD11b, CD11c, F4/80, and MHC II. Secreted cytokines were assessed by multiplex immunoassay: IFN-γ, IL-1β, IL-6, TNF-α, IL-10, IL-13, and IL-33. Results show that MGC maintained macrophage surface protein expression but lost the ability to produce a cytokine response. This suggests a potentially beneficial role of MGC in isolating the host from a foreign body without contributing to excessive inflammation. This study and future research using other stimulants and environments are important to gaining a fundamental MGC cell biology understanding. This will inform approaches to controlling the foreign body response to particle exposure, medical implants, and many diseases associated with granulomas.

Non-invasive computer navigation can quantify the pivot shift maneuver with good to excellent reliability in healthy volunteers

PURPOSE

The aim of this study was to determine the inter- and intra-observer reliability of knee laxity assessment using a non-invasive navigation system in a population of healthy young athletes. It was hypothesized that knee laxity parameters recorded using non-invasive computer navigation would demonstrate good inter- and intra-observer reliability.

METHODS

Healthy volunteers aged between 18 to 30 years were recruited to the study. Static and dynamic knee laxity parameters including anterior tibial translation and tibial rotation during the pivot shift test were recorded on awake patients using non-invasive computer navigation by two independent observers: at the first visit each athlete was evaluated by the consultant and resident surgeons independently; 6 weeks after the first visit all the participants were re-tested only by the resident surgeon. Inter- and intra-observer reliability was calculated and then interpreted according to Cicchetti's criteria.

RESULTS

One hundred healthy volunteers were recruited to the study, of these 38 were women (38%), and the average age was 25.5 ± 2.4 years. According to Cicchetti's criteria the intra- and inter-observer reliability for static measurements were fair for anterior tibial translation (0.572 and 0.529, respectively) and excellent for total passive tibial rotation (0.859 and 0.883, respectively). For the dynamic measurements of translation and rotation during the pivot shift maneuver both measurements demonstrated good to excellent reliability with intra and inter observer reliability ranging from 0.684 to 0.936.

CONCLUSION

Non-invasive navigation for the assessment of knee laxity is associated with fair to excellent inter- and intra-observer reliability in a population of healthy volunteers.

CgAATase with specific expression pattern can be used as a potential surface marker for oyster granulocytes

Granulocytes are known as the main immunocompetent hemocytes that play important roles in the immune defense of oyster Crassostrea gigas. In the present study, an alcohol acyltransferase (designed as CgAATase) with specific expression pattern was identified from oyster C. gigas, and it could be employed as a potential marker for the isolation of oyster granulocytes. The open reading frame (ORF) of CgAATase was of 1431 bp, encoding a peptide of 476 amino acids with a typically conserved AATase domain. The mRNA transcripts of CgAATase were highest expressed in hemocytes, lower expressed in hepatopancreas, mantle, gonad, gill, ganglion, adductor muscle, and labial palp. The mRNA expression level of CgAATase in hemocytes was significantly up-regulated at 3-12 h and reached the highest level (27.40-fold compared to control group, p < 0.05) at 6 h after Vibrio splendidus stimulation. The total hemocytes were sorted as granulocytes, semi-granulocytes and agranulocytes by Percoll^® density gradient centrifugation. CgAATase transcripts were dominantly observed in granulocytes, which was 8.26-fold (p < 0.05) and 2.80-fold (p < 0.05) of that in agranulocytes and semi-granulocytes, respectively. The monoclonal antibody against CgAATase was produced and employed for the isolation of granulocytes with the immunomagnetic bead. CgAATase protein was mainly detected on the cytomembrane of granulocytes. About 85.7 ± 4.60% of the granulocytes were positive for CgAATase and they could be successfully separated by flow cytometry with immunomagnetic bead coated with anti-CgAATase monoclonal antibody, and 97.7 ± 1.01% of the rest hemocytes (agranulocytes and semi-granulocytes) were negative for CgAATase. The isolated primary granulocytes could maintain cell activity for more than one week in vitro culture that exhibited numerous filopodia. These results collectively suggested that CgAATase was a potential marker of oyster granulocytes, and the granulocytes could be effectively isolated from total circulating hemocytes by immunomagnetic bead coated with the anti-CgAATase monoclonal antibody.

Mefloquine targets β-catenin pathway and thus can play a role in the treatment of liver cancer

The current study was designed and performed to investigate the effect of mefloquine on the proliferation and tumor formation potential of liver cancer stem cells. CD133 + HepG2 cells were identified using MACS and showed markedly higher tumor formation potential compared to the parental cells. The secondary tumors formed by CD133 + cells were markedly large in size and more in number compared to the parental cells. Mefloquine treatment of CD133 + HepG2 cells inhibited the proliferation selectively in concentration based manner. The rate of proliferation was inhibited to 82 and 12% in parental and CD133 + sphere forming cells, respectively on treatment with 10 μM concentration of mefloquine. The number of secondary tumors formed by primary tumors was decreased significantly on treatment with 10 μM mefloquine concentration. Treatment of the liver cancer stem cells with mefloquine markedly decreased the potential to undergo self-renewal at 10 μM concentration after 48 h. The results from western blot analysis showed significantly higher expression of cancer stem cell molecules β-catenin and cyclin D1 in LCSCs. Treatment of the LCSCs with various concentrations of mefloquine reduced the expression levels of β-catenin and cyclin D1. Administration of the CD133 + cell tumor xenografts in the mice led to the formation of large sized tumors in the control group. However, the tumor growth was inhibited significantly in the mice on treatment with 10 mg/kg doses of mefloquine after day 21. The tumor weight was significantly lower in the animals of mefloquine treatment group compared to the control group. Thus, mefloquine treatment inhibits self-renewal and proliferation potential of cells through targeting β-catenin pathway.

[Stem cells: searching predisposition to cardiac commitment by surface markers expression]

It is well-known that cardiovascular diseases are the leading cause of death worldwide, and represent an important economic burden to health systems. In an attempt to solve this problem, stem cell therapy has emerged as a therapeutic option. Within the last 20 years, a great variety of stem cells have been used in different myocardial infarction models. Up until now, the use of cardiac stem cells (CSCs) has seemed to be the best option, but the inaccessibility and scarcity of these cells make their use unreliable. Additionally, there is a high risk as they have to be obtained directly from the heart of the patient. Unlike CSCs, adult stem cells originating from bone marrow or adipose tissue, among others, appear to be an attractive option due to their easier accessibility and abundance, but particularly due to the probable existence of cardiac progenitors among their different sub-populations. In this review an analysis is made of the surface markers present in CSCs compared with other adult stem cells. This suggested the pre-existence of cells sharing specific surface markers with CSCs, a predictable immunophenotype present in some cells, although in low proportions, and with a potential of cardiac differentiation that could be similar to CSCs, thus increasing their therapeutic value. This study highlights new perspectives regarding MSCs that would enable some of these sub-populations to be differentiated at cardiac tissue level.

Flow Cytometry (FCM) Analysis and Fluorescence-Activated Cell Sorting (FACS) of Erythroid Cells

To study the process of erythropoiesis, it is important to be able to isolate erythroid progenitors and erythroblasts at distinct stages of development. During the past decade, considerable progress has been made on the development of flow cytometry (FCM) and fluorescence-activated cell sorting (FACS) methods for the analysis and isolation of both murine and human erythroid cells at distinct stages of erythropoiesis, based on changes in the expression of cell surface markers. A method for the identification of murine BFU-E and CFU-E cells was reported by Flygare et al., by negative selection for Ter119, B220, Mac-1, CD3, Gr1, Sca-1, CD16/CD32, CD41, and CD34 cells, followed by separation based on the expression levels of CD71. We developed an alternative method in which Ter119 is used as an erythroid lineage marker, and in conjunction with CD44 and cell size as differentiation markers, it is possible to unambiguously distinguish erythroblasts at each developmental stage during murine terminal erythroid differentiation. We also developed methods for the analysis and isolation of human erythroid cells at all developmental stages. BFU-E and CFU-E are characterized by CD45⁺GPA^-IL-3R^-CD34⁺CD36^-CD71^low and CD45⁺GPA^-IL-3R^-CD34^-CD36⁺CD71^high phenotypes, respectively; the combination of GPA, band 3 and α4-integrin are used to isolate erythroid cells at all of the terminal stages of human erythropoiesis, including proerythroblasts, early basophilic, late basophilic, polychromatic and orthochromatic erythroblasts.

Proteome analysis of human embryonic stem cells organelles

As the functions of proteins are associated with their cellular localization, the comprehensive sub-cellular proteome knowledge of human embryonic stem cells (hESCs) is indispensable for ensuring a therapeutic effect. Here, we have utilized a sub-cellular proteomics approach to analyze the localization of proteins in the nucleus, mitochondria, crude membrane, cytoplasm, heavy and light microsomes. Out of 2002 reproducibly identified proteins, we detected 762 proteins in a single organelle whereas 160 proteins were found in all sub-cellular fractions. We verified the localization of identified proteins through databases and discussed the consistency of the obtained results. With regards to the ambiguity in the definition of a membrane protein, we tried to clearly define the plasma membrane, peripheral membrane and membrane proteins by annotation of these proteins in databases, along with predictions of transmembrane helices. Among ten enriched signaling pathways highlighted in our results, non-canonical Wnt signaling were analyzed in greater detail. The functions of three novel hESC membrane proteins (ERBB4, GGT1 and ZDHHC13) have been assessed in terms of pluripotency. Our report is the most comprehensive for organellar proteomics of hESCs.

SIGNIFICANCE

Mass spectrometric identification of proteins using a TripleTOF 5600 from nucleus, mitochondria, crude membrane, cytoplasm, heavy and light microsomal fractions highlighted the significance of the non-canonical Wnt signaling in human embryonic stem cells.

Endothelial cell markers from clinician's perspective

Endothelial cell markers are membrane-bound or cytoplasmic molecules expressed by endothelial cells, which help their easier identification and discrimination from other cell types. During vasculogenesis, endothelial cells differentiate from hemangioblasts to form new blood vessels. With the discovery of endothelial progenitor cells (EPC) and their ability to form new blood vessels, the term vasculogenesis is not only reserved for the embryonic development. Possibility of de novo blood vessel formation from EPC is now widely explored in different ischemic conditions, especially in cardiovascular medicine. Numerous clinical trials have tested enhancing tissue vascularization by delivering hematopoietic cells that expressed endothelial markers. This therapeutic approach proved to be challenging and promising, particularly for patients who have exhausted all conventional therapeutic modalities. Angiogenesis, which refers to the formation of new blood vessels from existing vasculature, is indispensable process during tumor progression and metastasis. Blockage of tumor angiogenesis by targeting and inhibiting endothelial cell has emerged as novel safe and efficacious method to control many advanced malignant diseases. Numerous clinical studies are currently testing new antiangiogenic drugs which target and inhibit endothelial cell markers, receptors or molecules which transmit receptor-mediated signals, therefore inhibiting endothelial cell proliferation, migration and vascular tube formation. Many of these drugs are now widely used in clinical settings as first- or second-line chemotherapy in advanced malignant conditions. So far, these therapeutic approaches gave modest, yet encouraging clinical improvements, prolonging survival and improving functional capacity and quality of life for many terminally ill patients. Here we present the most commonly used endothelial cell markers along with their applicability in contemporary clinical practice.

Characterization and Classification of Mesenchymal Stem Cells in Several Species Using Surface Markers for Cell Therapy Purposes

Mesenchymal stem cells are multipotent cells capable of replicating as undifferentiated cells, and have the potential of differentiating into mesenchymal tissue lineages such as osteocytes, adipocytes and chondrocytes. Such lineages can then be used in cell therapy. The aim of present study was to characterize bone marrow derived mesenchymal stem cells in four different species, including: sheep, goat, human and mouse. Human bone-marrow mesenchymal stem cells were purchased, those of sheep and goat were isolated from fetal bone marrow, and those of mouse were collected by washing bone cavity of femur and tibia with DMEM/F12. Using flow-cytometry, they were characterized by CD surface antigens. Furthermore, cells of third passage were examined for their osteogenic and adipogenic differentiation potential by oil red and alizarin red staining respectively. According to the results, CD markers studied in the four groups of mesenchymal stem cells showed a different expression. Goat and sheep expressed CD44 and CD166, and weakly expressed CD34, CD45, CD105 and CD90. Similarly, human and mouse mesenchymal cells expressed CD44, CD166, CD105 and CD90 whereas the expression of CD34 and CD45 was negative. In conclusion, although all mesenchymal stem cells display plastic adherence and tri-lineage differentiation, not all express the same panel of surface antigens described for human mesenchymal stem cells. Additional panel of CD markers are necessary to characterize regenerative potential and possible application of these stem cells in regenerative medicine and implantology.

Effects of Physical Exercise on Markers of Cellular Immunosenescence: A Systematic Review

Aging affects negatively the immune system, defined as immunosenescence, which increases the susceptibility of elderly persons to infection, autoimmune disease, and cancer. There are strong indications that physical exercise in elderly persons may prevent the age-related decline in immune response without significant side effects. Consequently, exercise is being considered as a safe mode of intervention to reduce immunosenescence. The aim of this review was to appraise the existing evidence regarding the impact of exercise on surface markers of cellular immunosenescence in either young and old humans or animals. PubMed and Web of Science were systematically screened, and 28 relevant articles in humans or animals were retrieved. Most of the intervention studies demonstrated that an acute bout of exercise induced increases in senescent, naïve, memory CD4⁺ and CD8⁺ T-lymphocytes and significantly elevated apoptotic lymphocytes in peripheral blood. As regards long-term effects, exercise induced increased levels of T-lymphocytes expressing CD28⁺ in both young and elderly subjects. Few studies found an increase in natural killer cell activity following a period of training. We can conclude that exercise has considerable effects on markers of cellular aspects of the immune system. However, very few studies have been conducted so far to investigate the effects of exercise on markers of cellular immunosenescence in elderly persons. Implications for immunosenescence need further investigation.

In vivo Evaluation of Human Embryonic Stem Cells Isolated by 57-C11 Monoclonal Antibody

Background

The normal cells derived from human embryonic stem cells (hESCs) are regarded as substitutes for damaged or dysfunctional adult cells. However, tumorigenicity of hESCs remains a major challenge in clinical application of hESC-derived cell transplantation. Previously, we generated monoclonal antibody (MAb) 57-C11 specific to the surface molecule on undifferentiated hESCs. The aim of this study is to prove whether 57-C11-positive hESCs are pluripotent and tumorigenic in immunodeficient mice.

Methods

Undifferentiated hESCs were mixed with retinoic acid (RA)-differentiated hESCs at different ratios prior to 57-C11-mediated separation. To isolate 57-C11-positive hESCs from the mixture, biotinylated 57-C11 and streptavidin-coated magnetic beads were added to the mixture. Unbound 57-C11-negative hESCs were first isolated after applying magnet to the cell mixture, and 57-C11-bound hESCs were then released from the magnetic beads. In order to measure the efficiency of separation, 57-C11-positive or -negative hESCs were counted after isolation. To evaluate the efficiency of teratoma formation in vivo, 57-C11-positive or negative cells were further injected into left and right, respectively, testes of nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice.

Results

Approximately 77~100% of undifferentiated hESCs were isolated after applying 57-C11-coated magnetic beads to the mixed cell populations. Importantly, teratomas were not observed in NOD/SCID mice after the injection of isolated 57-C11-negative hESCs, whereas teratomas were observed with 57-C11-positive hESCs.

Conclusion

57-C11-positive hESCs are pluripotent and tumorigenic. The combination of 57-C11 and magnetic beads will be useful to eliminate remaining undifferentiated hESCs for the safe cell transplantation.

Established cell surface markers efficiently isolate highly overlapping populations of skeletal muscle satellite cells by fluorescence-activated cell sorting

Background

Fluorescent-activated cell sorting (FACS) has enabled the direct isolation of highly enriched skeletal muscle stem cell, or satellite cell, populations from postnatal tissue. Several distinct surface marker panels containing different positively selecting surface antigens have been used to distinguish muscle satellite cells from other non-myogenic cell types. Because functional and transcriptional heterogeneity is known to exist within the satellite cell population, a direct comparison of results obtained in different laboratories has been complicated by a lack of clarity as to whether commonly utilized surface marker combinations select for distinct or overlapping subsets of the satellite cell pool. This study therefore sought to evaluate phenotypic and functional overlap among popular satellite cell sorting paradigms.

Methods

Utilizing a transgenic Pax7-zsGreen reporter mouse, we compared the overlap between the fluorescent signal of canonical paired homeobox protein 7 (Pax7) expressing satellite cells to cells identified by combinations of surface markers previously published for satellite cells isolation. We designed two panels for mouse skeletal muscle analysis, each composed of markers that exclude hematopoietic and stromal cells (CD45, CD11b, Ter119, CD31, and Sca1), combined with previously published antibody clones recognizing surface markers present on satellite cells (β1-integrin/CXCR4, α7-integrin/CD34, and Vcam1). Cell populations were comparatively analyzed by flow cytometry and FACS sorted for functional assessment of myogenic activity.

Results

Consistent with prior reports, each of the commonly used surface marker schemes evaluated here identified a highly enriched satellite cell population, with 89–90 % positivity for Pax7 expression based on zsGreen fluorescence. Distinct surface marker panels were also equivalent in their ability to identify the majority of the satellite cell pool, with 90–93 % of all Pax7-zsGreen positive cells marked by each of the surface marker schemes. The direct comparison among surface marker schemes validated their selection for highly overlapping subsets of cells. Functional analysis in vitro showed no differences in the abilities of cells sorted by these different methods to grow in culture and differentiate.

Conclusions

This study demonstrates the equivalency of several previously published and widely utilized surface marker schemes for isolating a highly purified and myogenically active population of satellite cells from the mouse skeletal muscle, which should facilitate cross-comparison of data across laboratories.

Electronic supplementary material

The online version of this article (doi:10.1186/s13395-016-0106-6) contains supplementary material, which is available to authorized users.

Quantification of the pivot-shift test using a navigation system with non-invasive surface markers

PURPOSE

The purpose of this study was to validate the quantitation of the pivot-shift phenomenon by using a navigation system with non-invasive surface markers. Measurements obtained using this system were compared with those obtained using commercial pin-fixed markers.

METHODS

Seventy patients with anterior cruciate ligament (ACL) injuries were assessed under general anaesthesia. Knee kinematics during the pivot-shift test were recorded using an image-free navigation system with a commercial transmitter placed on the thigh and lower leg (surface markers) or those fixed to the femur and the tibia via metal pin fixators (pin-fixed markers). For quantitation of the pivot-shift phenomenon, posterior tibial reduction (PTR) was calculated using the two types of navigation system markers and were then compared. PTRs measured using the two types of markers were also compared with clinical grade of the pivot-shift test, as determined by an examiner.

RESULTS

The pivot-shift phenomenon could be identified in all patients on the navigation screen. The PTR measured using surface markers moderately correlated with that measured using pin-fixed markers (ρ = 0.524, p < 0.001). There were also moderate correlations between clinical grades and the PTRs measured using either the surface markers (ρ = 0.522, p < 0.001) or the pin-fixed markers (ρ = 0.645, p < 0.001).

CONCLUSIONS

The present study demonstrated that PTR, during the pivot-shift test, may be quantified in ACL-injured knees, using a navigation system with surface markers, and that the PTR measured with surface markers moderately correlated both with the PTR obtained using pin-fixed markers and with the clinical grade of the pivot-shift test. A customised method of fixing transmitters with reflective markers to patients' thighs and shins with Velcro straps is non-invasive and could assess and record the knee kinematics, especially the pivot-shift test, in ACL-injured and ACL-reconstructed knees before, during, and after surgery using a navigation system.

LEVEL OF EVIDENCE

Case series, Level IV.

Elevated level of pro inflammatory cytokine and chemokine expression in chicken bone marrow and monocyte derived dendritic cells following LPS induced maturation

The study was designed to characterize and compare chicken bone marrow and peripheral blood monocyte derived dendritic cells (chBM-DC and chMoDC) and to evaluate inflammatory cytokine and chemokine alterations in response upon LPS stimulation. Typical morphology was observed in DCs from 48h of culture using recombinant chicken GM-CSF and IL-4. Maturation of DCs with LPS (1μg/ml) showed significant up regulation of mRNA of surface markers (CD40, CD80, CD83, CD86, MHC-II and DC-LAMP (CD208)), pro-inflammatory cytokines (IL-1β, IL-6, TNF-α (LITAF)), iNOS, chemokine CXCli2 and TLRs4 and 15. Basal level of TLR1 mRNA expression was higher followed by TLR15 in both DCs irrespective of their origin. Expression of iNOS and CXCLi2 mRNA in mature DCs of both origins were higher than other surface molecules and cytokines studied. Hence, its level of expression can also be used as an additional maturation marker for LPS induced chicken dendritic cell maturation along with CD83 and CD40. LPS matured DCs of both origins upregulated IL-12 and IFN-γ. Based on CD40 and CD83 mRNA expression, it was observed that LPS induced the maturation in both DCs, but chMoDCs responded better in expression of surface markers and inflammatory mediator genes.

Murine mammary stem/progenitor cell isolation: Different method matters?

Murine mammary stem/progenitor cell isolation has been routinely used in many laboratories, yet direct comparison among different methods is lacking. In this study, we compared two frequently used digestion methods and three sets of frequently used surface markers for their efficiency in enriching mammary stem and progenitor cells in two commonly used mouse strains, C57BL/6J and FVB. Our findings revealed that the slow overnight digestion method using gentle collagenase/hyaluronidase could be easily adopted and yielded reliable and consistent results in different batches of animals. In contrast, the different fast digestion protocols, as described in published studies, yielded high percent of non-epithelial cells with very few basal epithelial cells liberated in our hands. The three sets of markers tested in our hands reveal rather equally efficiency in separating luminal and basal cells if same fluorochrome conjugations were used. However, the tendency of non-epithelial cell inclusion in the basal cell gate was highest in samples profiled by CD24/CD29 and lowest in samples profiled by CD49f/EpCAM, this is especially true in mammary cells isolated from C57BL/6J mice. This finding will have significant implication when sorted basal cells are used for subsequent gene expression analysis.

Developments in techniques for the isolation, enrichment, main culture conditions and identification of spermatogonial stem cells

The in vitro culture system of spermatogonial stem cells (SSCs) provides a basis for studies on spermatogenesis, and also contributes to the development of new methods for the preservation of livestock and animal genetic modification. In vitro culture systems have mainly been established for mouse SSCs, but are lacking for farm animals. We reviewed and analyzed the current progress in SSC techniques such as isolation, purification, cultivation and identification. Based on the published studies, we concluded that two-step enzyme digestion and magnetic-activated cell sorting are fast becoming the main methods for isolation and enrichment of SSCs. With regard to the culture systems, serum and feeders were earlier thought to play an important role in the self-renewal and proliferation of SSCs, but serum- and feeder-free culture systems as a means of overcoming the limitations of SSC differentiation in long-term SSC culture are being explored. However, there is still a need to establish more efficient and ideal culture systems that can also be used for SSC culture in larger mammals. Although the lack of SSC-specific surface markers has seriously affected the efficiency of purification and identification, the transgenic study is helpful for our identification of SSCs. Therefore, future studies on SSC techniques should focus on improving serum- and feeder-free culture techniques, and discovering and identifying specific surface markers of SSCs, which will provide new ideas for the optimization of SSC culture systems for mice and promote related studies in farm animals.

Advances in understanding the relationship between liver cancer stem cells and metastasis and relapse of liver cancer

Many factors may affect the prognosis of liver cancer, including late diagnosis, cirrhosis, and insensitivity of tumor cells to chemotherapy, and postoperative metastasis and relapse. Previous studies on the metastasis and relapse of liver cancer focused mainly on the migration and shedding of liver cancer cells, adhesion of liver cancer cells to surrounding tissue, and generation of peripheral vessels. The advances in research on liver cancer stem cells (LCSCs) have led to a better understanding of the metastasis and relapse of liver cancer. This paper gives a comprehensive review of LCSCs at the genetic level in terms of their origin and surface markers, signaling pathways involved, and treatment implications.

Expression of 3G11 epitope defines subpopulations of regulatory T cells with different suppressive potency

3G11, a sialylated carbohydrate epitope on the disialoganglioside molecule, is expressed predominantly on the surface of mouse CD4(+) T cells. Our previous studies suggested that lack of the 3G11 molecule could be a new cell surface marker for regulatory CD4(+) T cells. In the present study, we explore the relationship between 3G11(-) and CD25(+) T cells, a well-defined, naturally occurring regulatory T cell population. We found that a large proportion of CD25(+)CD4(+) T cells lack expression of 3G11 and that more 3G11(-)CD4(+) T cells express Foxp3 compared to the 3G11(+)CD4(+) population. Based on 3G11 and CD25 expression we sorted four CD4(+) T cell subpopulations and tested their phenotypes. Among four CD25/3G11-related CD4(+) T cell subpopulations, CD25(+)3G11(-) T cells expressed the highest levels of Foxp3 and IL-10 and most efficiently inhibited mitogenic and antigen-specific immune responses in vitro and clinical EAE in vivo, while CD25(-)3G11(+) T cells produced a higher level of proinflammatory cytokines and enhanced autoimmune responses. Thus, among CD4(+)CD25(+) T cells, CD25(+)3G11(-) T cells represent a more effective Treg subpopulation than CD25(+)3G11(+) T cells.

Advances in research on liver cancer stem cells

Cancer stem cells have been identified in various human tumors. However, it remains controversial as to whether or not liver cancer stem cells (LCSCs) exist until now. There are two hypotheses to explain the origin of liver cancer stem cells: the dedifferentiation of mature hepatocytes and the maturation arrest of liver stem cells. Now, the latter is generally acknowledged to be the better one. To obtain direct evidence for the existence of LCSCs, many researchers focus their studies on the surface markers on LCSCs to identify ideal markers for isolation of LCSCs. Besides, the relationship between side population (SP) cells and LCSCs also attracts much attention. Therefore, the study of LCSCs is probably of great significance for the diagnosis and treatment of liver cancer.