A systematic review and meta-analysis of the association between HOTAIR polymorphisms and susceptibility to breast cancer.

Introduction: Many studies are drawing attention to the associations of HOTAIR polymorphisms and susceptibility to breast cancer, while the results remain inconsistent. We conducted a meta-analysis on the association of four common HOTAIR polymorphisms with breast cancer susceptibility. Material and methods: Eligible published articles were searched in PubMed, Embase, Cochrane library databases and Web of Science databases up to July 2019. Odds ratios with 95% confidence intervals were used to identify potential links between lncRNA HOTAIR polymorphisms and the risk of breast cancer. Results: Our results showed no significance in all genetic models of all four SNPs. Pooled analyses detected crucial links between the rs1899663 polymorphism and decreased susceptibility to breast cancer in five genetic models rather than the dominant model in the hospital-based control subgroup. For the rs920778 polymorphism, we found that it significantly decreased breast cancer risk under recessive, homozygous and heterozygous models within the west Asian subgroup and increased breast cancer risk under allele and dominant models within the East Asian subgroup. Additionally, rs920778 polymorphism decreased breast cancer risk under recessive and heterozygous models in the hospital-based control subgroup. However, no significant association was observed between the rs4759314 polymorphism and breast cancer risk in overall and stratified analyses. For rs12826786 polymorphism, it was greatly associated with decreased breast cancer risk under recessive, homozygous and heterozygous models in the hospital-based control subgroup. Conclusions: HOTAIR rs920778, rs1899663 and rs12826786 polymorphisms may contribute to breast cancer susceptibility.

Molecular mechanism of SSFA2 deletion inhibiting cell proliferation and promoting cell apoptosis in glioma.

Gliomas are the most common primary brain malignant tumors in humans. Glioblastoma multiforme(GBM) is the most malignant intracranial tumor with a relatively poor prognosis. There promote us to find effective anti-cancer therapies to reduce cancer mortality. By using bioinformatic analysis, we found SSFA2 as a gene with elevated expression in the glioma tissues. We detected the expression of SSFA2 in glioma tissues and in the glioma cell lines, as well as in normal brain tissues. SSFA2 expression was higher in glioma tissues, especially in glioblastoma multiforme than normal brain tissues. Subsequently, we found that down-regulate SSFA2 in glioma cell lines can regulate the cell cycle to reduce the proliferation ability and induce the early apoptosis rate in shSSFA2 cells relative to control cells. Moreover, we found that down-regulate SSFA2 in glioma cell line U87(shSSFA2-U87) inhibited the growth effectiveness compared to the control cell line U87. These result reveals us that SSFA2 may act as oncogene to promote the progression of glioma. For further research specific mechanisms of SSFA2 in gliomas, we used the gene chip to detect the downstream gene in U87. We found that 30 genes also may be as target gene of SSFA2, and we testify the protein expression by western-blot. The result reveal that IL1A, IL1B and CDK6 as target gene of SSFA2 to regulate the progression of glioma. These finding suggest that SSFA2 could be a new therapeutic target for gliomas.

Luteolin induces hippocampal neurogenesis in the Ts65Dn mouse model of Down syndrome.

Studies have shown that the natural flavonoid luteolin has neurotrophic activity. In this study, we investigated the effect of luteolin in a mouse model of Down syndrome. Ts65Dn mice, which are frequently used as a model of Down syndrome, were intraperitoneally injected with 10 mg/kg luteolin for 4 consecutive weeks starting at 12 weeks of age. The Morris water maze test was used to evaluate learning and memory abilities, and the novel object recognition test was used to assess recognition memory. Immunohistochemistry was performed for the neural stem cell marker nestin, the astrocyte marker glial fibrillary acidic protein, the immature neuron marker DCX, the mature neuron marker NeuN, and the cell proliferation marker Ki67 in the hippocampal dentate gyrus. Nissl staining was used to observe changes in morphology and to quantify cells in the dentate gyrus. Western blot assay was used to analyze the protein levels of brain-derived neurotrophic factor (BDNF) and phospho-extracellular signal-regulated kinase 1/2 (p-ERK1/2) in the hippocampus. Luteolin improved learning and memory abilities as well as novel object recognition ability, and enhanced the proliferation of neurons in the hippocampal dentate gyrus. Furthermore, luteolin increased expression of nestin and glial fibrillary acidic protein, increased the number of DCX+ neurons in the granular layer and NeuN+ neurons in the subgranular region of the dentate gyrus, and increased the protein levels of BDNF and p-ERK1/2 in the hippocampus. Our findings show that luteolin improves behavioral performance and promotes hippocampal neurogenesis in Ts65Dn mice. Moreover, these effects might be associated with the activation of the BDNF/ERK1/2 pathway.

Emerging role of circadian rhythm in bone remodeling.

The 24-h rhythm of behavioral and physiological processes is a typical biological phenomenon regulated by a group of circadian rhythm genes. Dysfunction of the circadian rhythm can cause a wide range of problems, such as cancer and metabolic diseases. In recent decades, increased understanding of the roles of circadian rhythm genes in the bone remodeling process have been documented, including osteoblastic bone formation, osteoclastic bone resorption, and osteoblast/osteoclast communication. A timely review of the current findings may help to facilitate the new field of circadian rhythmic bone remodeling research. Targeted pharmacological modulation of circadian rhythm genes is a possible therapeutic approach through which to overcome bone remodeling problems in the future.

Long Non-coding RNAs: A New Regulatory Code for Osteoporosis.

Osteoporosis is a metabolic bone disease characterized by a decrease in bone mass and degradation of the bone microstructure, which increases bone fragility and fracture risk. However, the molecular mechanisms of osteoporosis remain unclear. Long non-coding RNAs (lncRNAs) have become important epigenetic regulators controlling the expression of genes and affecting multiple biological processes. Accumulating evidence of the involvement of lncRNAs in bone remolding has increased understanding of the molecular mechanisms underlying osteoporosis. This review aims to summarize recent progress in the elucidation of the role of lncRNAs in bone remodeling, and how it contributes to osteoblast and osteoclast function. This knowledge will facilitate the understanding of lncRNA roles in bone biology and shed new light on the modulation and potential treatment of osteoporosis.

Osteoclast-Derived Extracellular Vesicles: Novel Regulators of Osteoclastogenesis and Osteoclast-Osteoblasts Communication in Bone Remodeling.

Extracellular vesicles (EVs), including exosomes, microvesicles, and apoptotic bodies, play an important role in cellular communication during skeletal growth and homeostasis. Bioactive molecules carried by EVs are transported to neighboring and distant cells to trigger a series of signaling cascades influencing bone homeostasis. The bioactive activities of osteoclast-derived EVs include regulation of osteoclastogenesis and osteoclast-osteoblast communication. As osteoclast-derived EVs have the potential to regulate osteoclasts and osteoblasts, their application in osteoporosis and other bone metabolic disorders is currently under investigation. However, very few reviews of osteoclast-derived EVs in bone remodeling regulation have yet been published. This article aims to review recent advances in this field, summarizing a new regulator of osteoclastogenesis and osteoclast-osteoblast communication mediated by osteoclast-derived EVs. We will analyze the major challenges in the field and potential for the therapeutic application of EVs.

Isolation and Characterization of Human Chorionic Membranes Mesenchymal Stem Cells and Their Neural Differentiation.

Mesenchymal stem cells (MSCs) can be obtained from a variety of human tissues. Placenta has become an attractive stem cell source for potential applications in regenerative medicine and tissue engineering. The aim of this study was to localize and characterize MSCs within human chorionic membranes (hCMSCs). For this purpose, immunofluorescence labeling with CD105 and CD90 were used to determine the distribution of MSCs in chorionic membranes tissue. A medium supplemented with a synthetic serum and various concentrations of neurotrophic factors and cytokines was used to induce hCMSCs to neural cells. The results showed that the CD90 positive cells were scattered in the chorionic membranes tissue, and the CD105 positive cells were mostly located around the small blood vessels. hCMSCs expressed typical mesenchymal markers (CD73, CD90, CD105, CD44 and CD166) but not hematopoietic markers (CD45, CD34) and HLA-DR. hCMSCs differentiated into adipocytes, osteocytes, chondrocytes, and neuronal cells, as revealed by morphological changes, cell staining, immunofluorescence analyses, and RT-PCR showing the tissue-specific gene presence for differentiated cell lineages after the treatment with induce medium. Human chorionic membranes may be the source of MSCs for treatment of nervous system injury.

Human amniotic epithelial cells combined with silk fibroin scaffold in the repair of spinal cord injury.

Treatment and functional reconstruction after central nervous system injury is a major medical and social challenge. An increasing number of researchers are attempting to use neural stem cells combined with artificial scaffold materials, such as fibroin, for nerve repair. However, such approaches are challenged by ethical and practical issues. Amniotic tissue, a clinical waste product, is abundant, and amniotic epithelial cells are pluripotent, have low immunogenicity, and are not the subject of ethical debate. We hypothesized that amniotic epithelial cells combined with silk fibroin scaffolds would be conducive to the repair of spinal cord injury. To test this, we isolated and cultured amniotic epithelial cells, and constructed complexes of these cells and silk fibroin scaffolds. Implantation of the cell-scaffold complex into a rat model of spinal cord injury resulted in a smaller glial scar in the damaged cord tissue than in model rats that received a blank scaffold, or amniotic epithelial cells alone. In addition to a milder local immunological reaction, the rats showed less inflammatory cell infiltration at the transplant site, milder host-versus-graft reaction, and a marked improvement in motor function. These findings confirm that the transplantation of amniotic epithelial cells combined with silk fibroin scaffold can promote the repair of spinal cord injury. Silk fibroin scaffold can provide a good nerve regeneration microenvironment for amniotic epithelial cells.

Transplantation of mesenchymal stem cells expressing TIMP-1-shRNA improves hepatic fibrosis in CCl4-treated rats.

This study was to investigate the therapeutic effect of intravenous transplantation of TIMP-1-silencing mesenchymal stem cells (MSCs) in a rat model of liver fibrosis. MSCs were transduced with a lentiviral vector expressing tissue inhibitor of metalloproteinase 1 (TIMP-1)-shRNA, and the liver cirrhosis model was established by injection of CCl4 (1 ml/kg body weight twice a week for 4 weeks) in Sprague Dawley rats. The survived 36 rats were randomly divided into 3 groups: control group, MSCs group, and TIMP-1-shRNA group. At 4 weeks after establishment of animal model, 3×10(6) MSCs were intravenously injected. In TIMP-1-shRNA group, MSCs expressing TIMP-1-shRNA were transplanted. Animals were sacrificed 4 weeks later. Blood was collected for the detection of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). The livers were harvested for histological examination. At 5 days after transfection, strong fluorescence was detectable in each group. TIMP-1-shRNA group had the lowest TIMP-1 expression. Following MSCs transplantation, serum ALT and AST reduced in rats with hepatic cirrhosis, and histology showed less fibrotic areas and collagens, as compared to control group. These improvements were more obvious in the TIMP-1-shRNA group. Our study indicates that transplantation of MSCs expressing TIMP-1-shRNA is able to inhibit the progression of liver fibrosis and possibly restore the liver function in a rat model.

Effects of human amniotic mesenchymal stromal cells on rabbit T-cell responses in a xenolymphocyte reaction assay.

OBJECTIVES: To evaluate the immunomodulatory properties of human amniotic mesenchymal stromal cells. MATERIALS AND METHODS: Human amniotic mesenchymal stromal cells were isolated, characterized by flow cytometry, cultured in vitro, and evaluated in allogeneic and xenogeneic mixed lymphocyte reactions. The proliferation of T cells and the expression of interleukin 2 and interferon gamma by T cells were evaluated in the presence of human amniotic mesenchymal stromal cells. RESULTS: Human amniotic mesenchymal stromal cells were successfully isolated from human amniotic membranes and had well-defined human mesenchymal stem cell markers (CD90, CD73, CD105, and CD166). The human amniotic mesenchymal stromal cells inhibited the proliferation of human and rabbit T cells and the secretion of interleukin-2 and interferon gamma by human T cells. CONCLUSIONS: Human amniotic mesenchymal stromal cells may be useful for cell therapy and tissue engineering because of availability, phenotypic plasticity, and immunomodulatory properties.

Transplantation of human placenta-derived mesenchymal stem cells in a silk fibroin/hydroxyapatite scaffold improves bone repair in rabbits.

The main requirements for successful tissue engineering of the bone are non-immunogenic cells with osteogenic potential and a porous biodegradable scaffold. The purpose of this study is to evaluate the potential of a silk fibroin/hydroxyapatite (SF/HA) porous material as a delivery vehicle for human placenta-derived mesenchymal stem cells (PMSCs) in a rabbit radius defect model. In this study, we randomly assigned 16 healthy adult New Zealand rabbits into two groups, subjected to transplantation with either SF/HA and PMSCs (experimental group) or SF/HA alone (control group). To evaluate fracture healing, we assessed the extent of graft absorption, the quantity of newly formed bone, and re-canalization of the cavitas medullaris using radiographic and histological tools. We performed flow cytometric analysis to characterize PMSCs, and found that while they express CD90, CD105 and CD73, they stain negative for HLA-DR and the hematopoietic cell surface markers CD34 and CD45. When PMSCs were exposed to osteogenic induction medium, they secreted calcium crystals that were identified by von Kossa staining. Furthermore, when seeded on the surface of SF/HA scaffold, they actively secreted extracellular matrix components. Here, we show, through radiographic and histological analyses, that fracture healing in the experimental group is significantly improved over the control group. This strongly suggests that transplantation of human PMSCs grown in an SF/HA scaffold into injured radius segmental bone in rabbits, can markedly enhance tissue repair. Our finding provides evidence supporting the utility of human placenta as a potential source of stem cells for bone tissue engineering.

Human placenta-derived mesenchymal stem cells with silk fibroin biomaterial in the repair of articular cartilage defects.

Cartilage tissue engineering requires a porous biodegradable scaffold and nonimmunogenic cells with chondrogenic potential. In this study, the ability of the placenta-derived mesenchymal stem cells (PMSCs) to grow on silk fibroin (SF) biomaterial was determined, and the potential of a SF biomaterial serving as a delivery vehicle for human PMSCs in a rabbit articular cartilage defects model was evaluated. Human PMSCs were maintained in vitro in an allogeneic mixed lymphocyte reactions (MLR) system to investigate the suppressive effects on T cell proliferation. A total of 12 healthy adult New Zealand rabbits were implanted with a PMSC/SF biomaterial complex after articular cartilage defects of the femoral condyle in the knee were established. The repair of the articular cartilage defects was observed after 4 weeks, 8 weeks, and 12 weeks. Results from the MLR indicated that human PMSCs inhibited rabbit T cell responses. Knee damage was repaired by the newly formed hyaline cartilage, and within 12 weeks there was neither degeneration nor infiltration with lymphocytes or leukocytes, and no silk fibroin biomaterial residue was detected. In conclusion, the silk fibroin biomaterial can be applied as a new scaffold for cartilage tissue engineering, and implantation of human PMSCs on the cartilage can enhance repair of articular cartilage defects in a rabbit model.

Transplantation of human amniotic mesenchymal stem cells in the treatment of focal cerebral ischemia.

Cerebrovascular injury is one of the three major causes of death and is the leading cause of adult disability. Despite the increasing progress in emergency treatment and early rehabilitation in patients with cerebrovascular injury, treatment options for neurological dysfunction that presents at a later stage are lacking. This study examined the potential of human amniotic mesenchymal stem cell (hAMSC) transplantation in the repair of neurological deficits in an experimental focal cerebral ischemia model. Following the isolation of hAMSCs, growth characteristics and surface antigen expression were observed. Butylated hydroxyanisole (BHA) was used to induce the cultured cells into neuron-like cells, which were identified by immunocytochemistry. The suture model was used to induce focal cerebral ischemia in rats, which were subsequently randomly divided into experimental and control groups for treatment with BrdU-labeled hAMSCs or PBS, respectively. Neurological deficits were assessed following transplantation using the neurological severity score, beam balance test and elevated body swing test. Eight weeks later, rat brain tissue was analyzed with H&E staining and BrdU immunohistochemistry, and the survival and spatial distribution of the transplanted hAMSCs were determined. The hAMSCs proliferated in vitro, and it was found that neuron-specific enolase (NSE) was expressed in neurons, whereas glial fibrillary acidic protein (GFAP) was expressed in astrocytes. The focal ischemia model caused varying degrees of left limb hemiplegia accompanied by right sided Horner's Syndrome. When examined 1, 3, 6 and 8 weeks later, significant recovery in neurological behavior was detected in the rats treated with hAMSC transplantation compared with the control (P<0.01). BrdU-labeled hAMSCs were concentrated near the graft site and surrounding areas, in certain cases migrating towards the ischemic lesion. Local gliosis and lymphocytic infiltration were not detected. hAMSCs exhibit great potential for proliferation and are induced to differentiate into NSE-expressing neuron-like cells following treatment with BHA. Moreover, hAMSC transplantation may improve neurological symptoms following focal cerebral ischemia.

Increased frequency and clinical significance of myeloid-derived suppressor cells in human colorectal carcinoma.

AIM: To investigate the frequency and clinical significance of the myeloid-derived suppressor cells (MDSC) in human colorectal carcinoma (CRC). METHODS: Samples of peripheral blood and tumor tissue from 49 CRC patients were analyzed. Mononuclear cells were isolated by Ficoll-Hypaque density gradient centrifugation and were subjected to a flow cytometry-based immunophenotypic analysis. RESULTS: A considerable increase in the percentage of CD33⁺HLA-DR⁻ MDSCs was observed in the peripheral blood (1.89% ± 0.75%) and tumor tissues (2.99% ± 1.29%) of CRC patients as compared with that in the peripheral blood of healthy controls (0.54% ± 0.35%). This expanded CD33⁺HLA-DR⁻ subset exhibited immature myeloid cell markers, but not lineage markers, and showed up-regulation of CD18/CD11b expression as compared with the MDSCs from healthy donors. Further studies showed that the MDSC proportion in CRC peripheral blood was correlated with nodal metastasis(P = 0.023), whereas that in tumor tissues was correlated with nodal/distant metastasis (P = 0.016/P = 0.047) and tumor stage (P = 0.028), suggesting the involvement of MDSCs in CRC tumor development. CONCLUSION: Characterization of MDSCs in CRC suggests the clinical significance of circulating and tumor-infiltrating MDSCs and may provide new insights into the CRC immunotherapy targeting MDSCs.

Isolation of mesenchymal stem cells from human placenta: comparison with human bone marrow mesenchymal stem cells.

The presence within bone marrow of a population of mesenchymal stem cells (MSCs) able to differentiate into a number of different mesenchymal tissues, including bone and cartilage, was first suggested by Friedenstein nearly 40 years ago. Since then MSCs have been demonstrated in a variety of fetal and adult tissues, including bone marrow, fetal blood and liver, cord blood, amniotic fluid and, in some circumstances, in adult peripheral blood. MSCs from all of these sources can be extensively expanded in vitro and when cultured under specific permissive conditions retain their ability to differentiate into multiple lineages including bone, cartilage, fat, muscle, nerve, glial and stromal cells. There has been great interest in these cells both because of their value as a model for studying the molecular basis of differentiation and because of their therapeutic potential for tissue repair and immune modulation. However, MSCs are a rare population in these tissues. Here we tried to identify cells with MSC-like potency in human placenta. We isolated adherent cells from trypsin-digested term placentas and examined these cells for morphology, surface markers, and differentiation potential and found that they expressed several stem cell markers. They also showed endothelial and neurogenic differentiation potentials under appropriate conditions. We suggest that placenta-derived cells have multilineage differentiation potential similar to MSCs in terms of morphology and cell-surface antigen expression. The placenta may prove to be a useful source of MSCs.