Andy Peng Xiang

Sun Yat-Sen University, Shengcheng, Guangdong, China

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Publications (83)413.7 Total impact

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    Full-text · Dataset · Jan 2016
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    Full-text · Dataset · Jan 2016
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    Full-text · Dataset · Jan 2016
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    Full-text · Dataset · Jan 2016
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    Full-text · Dataset · Jan 2016
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    ABSTRACT: Mesenchymal stem cells (MSCs) have recently been shown to home to tumors and contribute to the formation of the tumor-associated stroma. In addition, MSCs can secrete paracrine factors to facilitate tumor progression. However, the involvement of MSC-derived cytokines in colorectal cancer (CRC) angiogenesis and growth has not been clearly addressed. In this study, we report that interleukin-8 (IL-8) was the most highly upregulated pro-angiogenic factor in MSCs co-cultured with CRC cells and was expressed at substantially higher levels in MSCs than CRC cells. To evaluate the effect of MSC-derived IL-8 on CRC angiogenesis and growth, we used MSCs that expressed small hairpin (interfering) RNAs (shRNA) targeting IL-8 (shIL-8-MSCs). We found that MSC-secreted IL-8 promoted human umbilical vein endothelial cell (HUVEC) proliferation and migration, tube-formation ability and CRC cell proliferation. Additionally, in vivo studies showed that MSCs promoted tumor angiogenesis partially through IL-8. Taken together, these findings suggest that IL-8 secreted by MSCs promotes CRC angiogenesis and growth and can therefore serve as a potential novel therapeutic target.
    Preview · Article · Oct 2015 · Oncotarget
  • J Wang · J Cai · Y Huang · Q Ke · B Wu · S Wang · X Han · T Wang · Y Wang · W Li · C Lao · W Song · A P Xiang
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    ABSTRACT: Nestin is widely expressed in numerous tumors and has become a diagnostic and prognostic indicator. However, the exact mechanism by which nestin contributes to tumor malignancy remains poorly understood. Here, we found marked upregulation of nestin expression in highly proliferative and invasive gastrointestinal stromal tumor (GIST) specimens. Nestin knockdown in GIST cells reduced the proliferative and invasive activity owing to a decrease of mitochondrial intracellular reactive oxygen species (ROS) generation. Furthermore, nestin was co-localized with mitochondria, and knockdown of nestin increased mitochondrial elongation and influenced the mitochondrial function, including oxygen consumption rates, ATP generation and mitochondrial membrane potential and so on. In exploring the underlying mechanism, we demonstrated nestin knockdown inhibited the mitochondrial recruitment of Dynamin-related protein1 and induced the change of mitochondrial dynamics. Thus, nestin may have an important role in GIST malignancy by regulating mitochondrial dynamics and altering intracellular ROS levels. The findings provide new clues to reveal mechanisms by which nestin mediates the proliferation and invasion of GISTs.Oncogene advance online publication, 5 October 2015; doi:10.1038/onc.2015.370.
    No preview · Article · Oct 2015 · Oncogene
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    ABSTRACT: Renal resident mesenchymal stem cells (MSCs) are important regulators of kidney homeostasis, repair or regeneration. However, natural distribution and the starting population properties of these cells remain elusive because of the lack of specific markers. Here, we identified post-natal kidney derived Nestin(+) cells that fulfilled all of the criteria as a mesenchymal stem cell. These isolated Nestin(+) cells expressed the typical cell-surface marker of MSC, including Sca-1, CD44, CD106, NG2 and PDGFR-α. They were capable of self-renewal, possessed high clonogenic potential and extensive proliferation for more than 30 passages. Under appropriate differentiation conditions, these cells could differentiate into adipocytes, osteocytes, chondrocytes and podocytes. After intravenous injection into acute kidney injury mice, Nestin(+) cells contributed to functional improvement by significantly decreasing the peak level of serum creatinine and BUN, and reducing the damaged cell apoptosis. Furthermore, conditioned medium from Nestin(+) cells could protect against ischemic acute renal failure partially through paracrine factor VEGF. Taken together, our findings indicate that renal resident Nestin(+) MSCs can be derived, propagated, differentiated, and repair the acute kidney injury, which may shed new light on understanding MSCs biology and developing cell replacement therapies for kidney disease. Copyright © 2015 Elsevier Ltd. All rights reserved.
    No preview · Article · May 2015 · Biomaterials
  • X Du · X H Yang · YF Wu · J Liang · J Zhang · Z C Huang · Z P Zhu · W Lin · M X Zou · JY Wen · S J Wu · R Guo · X M Zhang · B T Lahn · Feng He · AP Xiang
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    ABSTRACT: Nestin is a neuroepithelial stem cell marker that is expressed in some types of tumor cells. Recent reports suggest that Nestin may be closely related to malignant cell proliferation and migration. Acute leukemia (AL) is characterized by a lack of differentiation, which results in uncontrolled proliferation in the bone marrow and accumulation of immature cells. The expression and function of Nestin in AL is unclear. We investigated Nestin immunohistochemical patterns of 87 patients that included 47 cases of acute myeloid leukemia (AML) and 40 cases of acute lymphoblastic leukemia (ALL), and 20 patients in complete remission (CR) from AML or ALL. We also investigated the clinico-pathological features of 87 cases of AL and their CR and overall survival (OS). Nestin was expressed in leukemic blasts and mature granulocytic cells in most cases (39/47) of AML. Conversely, Nestin was expressed in mature granulocytic cells in fewer cases (6/40) of ALL, but not in blasts. Nestin expression appeared in leukemic blasts of AML, but not ALL. Nestin expression in AML blast cells was not associated with CR or OS. We provide evidence that Nestin is expressed in AL and might be a useful immunohistochemical marker for identifying AML and ALL.
    No preview · Article · Apr 2015 · Biotechnic & Histochemistry
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    ABSTRACT: One important aspect of mesenchymal stromal cells (MSCs)-mediated immunomodulation is the recruitment and induction of regulatory T (Treg) cells. However, we do not yet know whether MSCs have similar effects on the other subsets of Treg cells. Herein, we studied the effects of MSCs on CD8(+)CD28(-) Treg cells and found that the MSCs could not only increase the proportion of CD8(+)CD28(-) T cells, but also enhance CD8(+)CD28(-)T cells' ability of hampering naive CD4(+) T-cell proliferation and activation, decreasing the production of IFN-γ by activated CD4(+) T cells and inducing the apoptosis of activated CD4(+) T cells. Mechanistically, the MSCs affected the functions of the CD8(+)CD28(-) T cells partially through moderate upregulating the expression of IL-10 and FasL. The MSCs had no distinct effect on the shift from CD8(+)CD28(+) T cells to CD8(+)CD28(-) T cells, but did increase the proportion of CD8(+)CD28(-) T cells by reducing their rate of apoptosis. In summary, this study shows that MSCs can enhance the regulatory function of CD8(+)CD28(-) Treg cells, shedding new light on MSCs-mediated immune regulation.Cellular & Molecular Immunology advance online publication, 8 December 2014; doi:10.1038/cmi.2014.118.
    Preview · Article · Dec 2014 · Cellular & molecular immunology
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    ABSTRACT: In the past decades increasing lines of evidence have demonstrated that adipose tissue, as an endocrine organ played central role in metabolic homeostasis and its related maladies. CCAAT/enhancer-binding protein (C/EBP) family members and the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ) were known to be the vital transcription factors in the regulation of adipogenesis. However, the exact mechanism for increased marrow fat in patients with bone metabolic diseases, such as osteoporosis, is still poorly understood. Herein, we studied the expression pattern of PPARγ and C/EBPs in human bone marrow mesenchymal stem cell (hBMSC) adipogenesis and evaluated the effects of individual component of adipogenic cocktail on the differentiation and transcription factor expression. We furthermore examined whether the ERK signaling pathway was involved in mediating these effects. These findings showed that C/EBPβ and C/EBPδ were detected in undifferentiated hBMSC and maintained during the whole process of adipogenesis, and could initiate the expression of PPARγ1 under the treatment of dexamethasone and IBMX. Subsequently, the activation of PPARγ1 by indomethacin, its exogenous ligand, activated C/EBPα, which, together with IBMX, up-regulated PPARγ2 expression and therefore the fullest adipogenesis. Insulin and its downstream signal pathway extracellular signal-regulated kinases (ERK), however, were found not necessary for hBMSC adipogenesis. Our results revealed some unique characteristics of human adipocyte formation, which may help to understand the molecular mechanisms of bone marrow adipogenesis and give insights into the treatment of osteoporosis.
    No preview · Article · Dec 2014 · Cell Biology International
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    ABSTRACT: Cell death and differentiation is a monthly research journal focused on the exciting field of programmed cell death and apoptosis. It provides a single accessible source of information for both scientists and clinicians, keeping them up-to-date with advances in the field. It encompasses programmed cell death, cell death induced by toxic agents, differentiation and the interrelation of these with cell proliferation.
    No preview · Article · Nov 2014 · Cell Research
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    ABSTRACT: The ability to identify and isolate lineage-specific stem cells from adult tissues could facilitate cell replacement therapy. Leydig cells (LCs) are the primary source of androgen in the mammalian testis, and the prospective identification of stem Leydig cells (SLCs) may offer new opportunities for treating testosterone deficiency. Here, in a transgenic mouse model expressing GFP driven by the Nestin (Nes) promoter, we observed Nes-GFP(+) cells located in the testicular interstitial compartment where SLCs normally reside. We showed that these Nes-GFP(+) cells expressed LIFR and PDGFR-α, but not LC lineage markers. We further observed that these cells were capable of clonogenic self-renewal and extensive proliferation in vitro and could differentiate into neural or mesenchymal cell lineages, as well as LCs, with the ability to produce testosterone, under defined conditions. Moreover, when transplanted into the testes of LC-disrupted or aging models, the Nes-GFP(+) cells colonized the interstitium and partially increased testosterone production, and then accelerated meiotic and post-meiotic germ cell recovery. In addition, we further demonstrated that CD51 might be a putative cell surface marker for SLCs, similar with Nestin. Taken together, these results suggest that Nes-GFP(+) cells from the testis have the characteristics of SLCs, and our study would shed new light on developing stem cell replacement therapy for testosterone deficiency.Cell Research advance online publication 21 November 2014; doi:10.1038/cr.2014.149.
    Preview · Article · Nov 2014 · Cell Research
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    ABSTRACT: Neural crest stem cells (NCSCs), a population of multipotent cells that migrate extensively and give rise to diverse derivatives, including peripheral and enteric neurons and glia, craniofacial cartilage and bone, melanocytes and smooth muscle, have great potential for regenerative medicine. Non-human primates provide optimal models for the development of stem cell therapies. Here, we describe the first derivation of NCSCs from cynomolgus monkey embryonic stem cells (CmESCs) at the neural rosette stage. CmESC-derived neurospheres replated on polyornithine/laminin-coated dishes migrated onto the substrate and showed characteristic expression of NCSC markers, including Sox10, AP2α, Slug, Nestin, p75, and HNK1. CmNCSCs were capable of propagating in an undifferentiated state in vitro as adherent or suspension cultures, and could be subsequently induced to differentiate towards peripheral nervous system lineages (peripheral sympathetic neurons, sensory neurons, and Schwann cells) and mesenchymal lineages (osteoblasts, adipocytes, chondrocytes, and smooth muscle cells). CmNCSCs transplanted into developing chick embryos or fetal brains of cynomolgus macaques survived, migrated, and differentiated into progeny consistent with a neural crest identity. Our studies demonstrate that CmNCSCs offer a new tool for investigating neural crest development and neural crest-associated human disease and suggest that this non-human primate model may facilitate tissue engineering and regenerative medicine efforts.
    No preview · Article · Nov 2014 · Biomaterials
  • Y Peng · X Chen · Q Liu · X Zhang · K Huang · L Liu · H Li · M Zhou · F Huang · Z Fan · J Sun · M Ke · X Li · Q Zhang · A P Xiang
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    ABSTRACT: Refractory chronic graft-versus-host disease (cGVHD) is a significant complication resulting from allogeneic hematopoietic stem cell transplantation (HSCT). Mesenchymal stromal cells (MSCs) have shown promise for treating refractory chronic graft-versus-host disease (cGVHD), but the favorable effects of MSCs therapy in cGVHD are complex and not fully understood. In this prospective clinical study, 20 of 23 cGVHD patients had a complete response (CR) or partial response (PR) in a 12-month follow-up study. The most dramatic improvements in cGVHD symptoms were observed in the skin, oral mucosa, and liver. Clinical improvement was accompanied by a significantly increased number of IL-10-producing CD5+ B cells. Importantly, CD5+ B cells from cGVHD patients showed increased IL-10 expression after MSCs treatment, which was associated with reduced inflammatory cytokine production by T cells. Mechanistically, MSCs could promote the survival and proliferation of CD5+ regulatory B cells (Bregs), and indoleamine 2, 3-dioxygenase (IDO) partially participates in the MSC-mediated effects on Breg cells. Thus, CD5+ Breg cells might play an important role in the process of MSC-induced amelioration of refractory cGVHD and may provide new clues to reveal novel mechanisms of action for MSCs.Leukemia accepted article preview online, 18 July 2014; doi:10.1038/leu.2014.225.
    No preview · Article · Jul 2014 · Leukemia
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    ABSTRACT: Although mesenchymal stromal cells (MSCs) possess immunomodulatory properties and exhibit promising efficacy against chronic graft-versus-host disease (cGVHD), little is known about the immune changes by which MSCs ameliorate cGVHD in vivo. Recent studies have suggested that B lymphocytes might play an important role in the pathogenesis of cGVHD. In this study, we investigated changes in the numbers, phenotypes, and subpopulations of B lymphocytes in cGVHD patients who showed a complete response (CR), partial response (PR), or no response (NR) after MSC treatment. We found that the frequencies and numbers of CD27(+) memory and pre-germinal center B lymphocytes were significantly increased in the CR and PR cGVHD patients after MSC treatment but decreased in the NR patients. A further analysis of CR/PR cGVHD patients showed that MSC treatment led to a decrease in the plasma levels of B cell-activating factor (BAFF) and increased expression of the BAFF receptor (BAFF-R) on peripheral B lymphocytes but no changes in plasma BAFF levels or BAFF-R expression on B lymphocytes in NR patients. Overall, our findings imply that MSCs might exert therapeutic effects in cGVHD patients, accompanied by alteration of naïve and memory B-cell subsets, modulating plasma BAFF levels and BAFF-R expression on B lymphocytes.
    No preview · Article · Jul 2014 · STEM CELLS TRANSLATIONAL MEDICINE
  • Chun Guang Di · Andy Peng Xiang · Lei Jia · Jun Feng Liu · Bruce T Lahn · Bao Feng Ma
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    ABSTRACT: Nestin knockout leads to embryonic lethality and self-renewal deficiency in neural stem cells (NSCs). However, how nestin maintains self-renewal remains uncertain. Here, we used the dosage effect of nestin in heterozygous mice (Nes+/-) to study self-renewal of NSCs. With existing extracellular signaling in vivo or in vitro, nestin levels do not affect proliferation ability or apoptosis when compared between Nes+/- and Nes+/+ NSCs. However, self-renewal ability of Nes+/- NSCs is impaired when plated at a low cell density and completely lost at a clonal density. This deficiency in self-renewal at a clonal density is rescued using a medium conditioned by Nes+/+ NSCs. In addition, the Akt signaling pathway is altered at low density and reversed by conditioned medium. Our data show that secreted factors contribute toward maintaining self-renewal of NSCs by nestin, potentially through Akt signaling.
    No preview · Article · Jul 2014 · Neuroreport
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    ABSTRACT: The LIM‐homeobox transcription factor islet‐1 (ISL1) has been proposed to mark a cardiovascular progenitor cell lineage that gives rise to cardiomyocytes, endothelial cells, and smooth muscle cells. The aim of this study was to investigate whether forced expression of ISL1 in human mesenchymal stem cells (hMSCs) influenced the differentiation capacity and angiogenic properties of hMSCs. The lentiviral vector, EF1α‐ISL1, was constructed using the Multisite Gateway System and used to transduce hMSCs. We found that ISL1 overexpression did not alter the proliferation, migration, or survival of hMSCs or affect their ability to differentiate into osteoblasts, adipocytes, cardiomyocytes, or endotheliocytes. However, ISL1‐hMSCs differentiated into smooth muscle cells more efficiently than control hMSCs. Furthermore, conditioned medium from ISL1‐hMSCs greatly enhanced the survival, migration, and tube‐formation ability of human umbilical vein endothelial cells (HUVECs) in vitro. In vivo angiogenesis assays also showed much more vascular‐like structures in the group cotransplanted with ISL1‐hMSCs and HUVECs than in the group cotransplanted with control hMSCs and HUVECs. Quantitative RT‐PCR and antibody arrays detected monocyte chemoattractant protein‐3 (MCP3) at a higher level in conditioned medium from ISL1‐hMSCs cultures than in conditioned medium from control hMSCs. Neutralization assays showed that addition of an anti‐MCP3 antibody to ISL1‐hMSCs‐conditioned medium efficiently abolished the angiogenesis‐promoting effect of ISL1‐hMSCs. Our data suggest that overexpression of ISL1 in hMSCs promotes angiogenesis in vitro and in vivo through increasing secretion of paracrine factors, smooth muscle differentiation ability, and enhancing the survival of HUVECs. Stem Cells 2014;32:1843–1854
    No preview · Article · Jul 2014 · Stem Cells
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    ABSTRACT: Background The stem cell-associated intermediate filament nestin has recently been linked with neoplastic transformation, but the specific mechanism by which nestin positive tumor cells leads to malignant invasion and metastasis behaviors of esophageal squamous cell carcinoma (ESCC) remains unclear. Methods To obtain insight into the biological role of nestin in ESCC, we explored the association of the nestin phenotype with malignant proliferation and apoptosis in esophageal squamous cancer cells. Nestin expression was determined in ESCC specimens and cell lines, and correlated with clinicopathological properties, including clinical prognosis and proliferative markers. The association of the nestin phenotype with apoptotic indicators was also analyzed. Results Nestin was expressed in ESCC specimens and cell lines. ESCC patients with nestin-positive tumors had significantly shorter median survival and progression-free survival times than those with nestin-negative tumors. Positive staining for the proliferation markers Ki67 and PCNA (proliferating cell nuclear antigen) was detected in 56.9% and 60.2% of ESCC specimens, respectively, and was strongly correlated with the nestin phenotype. Notably, expression of cyclin dependent kinase-5 (CDK5) and P35 was detected in 53.8% and 48.4% of ESCC specimens, respectively, and was strongly associated with the nestin phenotype. Conclusion Our data demonstrated nestin expression in ESCC specimens and cell lines, and revealed a strong association of the nestin phenotype with poor prognosis in ESCC patients. Furthermore, we showed that nestin positive ESCC cells played an important role in the malignant proliferation and apoptosis.
    Preview · Article · Jun 2014 · Cancer Cell International
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    ABSTRACT: Nestin is associated with neoplastic transformation, but the mechanisms by which nestin contributes to invasion and malignancy of lung cancer remain unknown. Considering that proliferation is necessary for malignant behavior, we investigated the mechanism of nestin action in association with the proliferative properties of non-small cell lung cancer (NSCLC). Nestin expression was examined in NSCLC specimens and cell lines. Associations with clinicopathological features, including prognosis and proliferative markers, were evaluated. Effects of nestin knockdown on proliferation and the signaling pathways involved were further investigated. Nestin was expressed in most cancer specimens and all the tumor cell lines analyzed. High nestin expression in malignant tissue was associated with high Ki-67 or PCNA levels and poor patient outcomes. Conversely, knockdown of nestin expression led to significant inhibition of tumor cell proliferation, decreased colony forming ability, and cell cycle G1 arrest. Furthermore, nestin knockdown resulted in inhibition of Akt and GSK3β activation. Our data demonstrate that nestin expression in NSCLC cells is associated with poor prognosis of patients and tumor cell proliferation pathway. Downregulation of nestin efficiently inhibited lung cancer cell proliferation, which might be through affecting cell cycle arrest and Akt-GSK3β-Rb signaling pathway.
    Preview · Article · Feb 2014 · PLoS ONE

Publication Stats

2k Citations
413.70 Total Impact Points

Institutions

  • 2006-2015
    • Sun Yat-Sen University
      • • Department of Biochemistry
      • • Key Laboratory of Stem Cell Biology and Tissue Engineering
      Shengcheng, Guangdong, China
  • 2010
    • Howard Hughes Medical Institute
      Ashburn, Virginia, United States