Bio

Professional Education


  • Doctor of Dental Medicine, Peking University School of Stomatology, Dentistry (2003)
  • Master of Orthodontics, Peking University School of Stomatology, Orthodontics (2005)
  • Doctor of Philosophy, Hong Kong University Of Science & Technology (2009)

Stanford Advisors


Publications

Journal Articles


  • A Novel Aldehyde Dehydrogenase-3 Activator (Alda-89) Protects Submandibular Gland Function from Irradiation without Accelerating Tumor Growth CLINICAL CANCER RESEARCH Xiao, N., Cao, H., Chen, C., Kong, C. S., Ali, R., Chan, C., Sirjani, D., Graves, E., Koong, A., Giaccia, A., Mochly-Rosen, D., Quynh-Thu Le, Q. T. 2013; 19 (16): 4455-4464

    Abstract

    To determine the effect of Alda-89 (an ALDH3 activitor) on (1) the function of irradiated (RT) submandibular gland (SMG) in mice, (2) its toxicity profile and (3) its effect on the growth of head and neck cancer (HNC) in vitro and in vivo.Adult mice were infused with Alda-89 or vehicle before, during and after RT. Saliva secretion was monitored weekly. Hematology, metabolic profile and post-mortem evaluation for toxicity were examined at the time of sacrifice. Alda-89 or vehicle was applied to HNC cell lines in vitro, and SCID mice transplanted with HNC in vivo with or without radiation; HNC growth was monitored. The ALDH3A1 and ALDH3A2 protein expression was evaluated in 89 HNC patients and correlated to freedom from relapse (FFR) and overall survival (OS).Alda-89 infusion significantly resulted in more whole saliva production and a higher percentage of preserved acini after RT compared to vehicle control. There was no difference in the complete blood count, metabolic profile, and major organ morphology between the Alda-89 and vehicle groups. Compared to vehicle control, Alda-89 treatment did not accelerate HNC cell proliferation in vitro, nor did it affect tumor growth in vivo with or without RT. Higher expression of ALDH3A1 or ALDH3A2 was not significantly associated with worse FFR or OS in either HPV-positive or HPV-negative group.Alda-89 preserves salivary function after RT without affecting HNC growth or causing measurable toxicity in mice. It is a promising candidate to mitigate RT-related xerostomia.

    View details for DOI 10.1158/1078-0432.CCR-13-0127

    View details for Web of Science ID 000323147700018

  • PICK1 and ICA69 Control Insulin Granule Trafficking and Their Deficiencies Lead to Impaired Glucose Tolerance. PLoS biology Cao, M., Mao, Z., Kam, C., Xiao, N., Cao, X., Shen, C., Cheng, K. K., Xu, A., Lee, K., Jiang, L., Xia, J. 2013; 11 (4)

    Abstract

    Diabetes is a metabolic disorder characterized by hyperglycemia. Insulin, which is secreted by pancreatic beta cells, is recognized as the critical regulator of blood glucose, but the molecular machinery responsible for insulin trafficking remains poorly defined. In particular, the roles of cytosolic factors that govern the formation and maturation of insulin granules are unclear. Here we report that PICK1 and ICA69, two cytosolic lipid-binding proteins, formed heteromeric BAR-domain complexes that associated with insulin granules at different stages of their maturation. PICK1-ICA69 heteromeric complexes associated with immature secretory granules near the trans-Golgi network (TGN). A brief treatment of Brefeldin A, which blocks vesicle budding from the Golgi, increased the amount of PICK1 and ICA69 at TGN. On the other hand, mature secretory granules were associated with PICK1 only, not ICA69. PICK1 deficiency in mice caused the complete loss of ICA69 and led to increased food and water intake but lower body weight. Glucose tolerance tests demonstrated that these mutant mice had high blood glucose, a consequence of insufficient insulin. Importantly, while the total insulin level was reduced in PICK1-deficient beta cells, proinsulin was increased. Lastly, ICA69 knockout mice also displayed similar phenotype as the mice deficient in PICK1. Together, our results indicate that PICK1 and ICA69 are key regulators of the formation and maturation of insulin granules.

    View details for DOI 10.1371/journal.pbio.1001541

    View details for PubMedID 23630453

  • A Novel Aldehyde Dehydrogenase-3 Activator Leads to Adult Salivary Stem Cell Enrichment In Vivo CLINICAL CANCER RESEARCH Banh, A., Xiao, N., Cao, H., Chen, C., Kuo, P., Krakow, T., Bavan, B., Khong, B., Yao, M., Ha, C., Kaplan, M. J., Sirjani, D., Jensen, K., Kong, C. S., Mochly-Rosen, D., Koong, A. C., Quynh-Thu Le, Q. T. 2011; 17 (23): 7265-7272

    Abstract

    To assess aldehyde dehydrogenase (ALDH) expression in adult human and murine submandibular gland (SMG) stem cells and to determine the effect of ALDH3 activation in SMG stem cell enrichment.Adult human and murine SMG stem cells were selected by cell surface markers (CD34 for human and c-Kit for mouse) and characterized for various other stem cell surface markers by flow cytometry and ALDH isozymes expression by quantitative reverse transcriptase PCR. Sphere formation and bromodeoxyuridine (BrdUrd) incorporation assays were used on selected cells to confirm their renewal capacity and three-dimensional (3D) collagen matrix culture was applied to observe differentiation. To determine whether ALDH3 activation would increase stem cell yield, adult mice were infused with a novel ALDH3 activator (Alda-89) or with vehicle followed by quantification of c-Kit(+)/CD90(+) SMG stem cells and BrdUrd(+) salispheres.More than 99% of CD34(+) huSMG stem cells stained positive for c-Kit, CD90 and 70% colocalized with CD44, Nestin. Similarly, 73.8% c-Kit(+) mSMG stem cells colocalized with Sca-1, whereas 80.7% with CD90. Functionally, these cells formed BrdUrd(+) salispheres, which differentiated into acinar- and ductal-like structures when cultured in 3D collagen. Both adult human and murine SMG stem cells showed higher expression of ALDH3 than in their non-stem cells and 84% of these cells have measurable ALDH1 activity. Alda-89 infusion in adult mice significantly increased c-Kit(+)/CD90(+) SMG population and BrdUrd(+) sphere formation compared with control.This is the first study to characterize expression of different ALDH isozymes in SMG stem cells. In vivo activation of ALDH3 can increase SMG stem cell yield, thus providing a novel means for SMG stem cell enrichment for future stem cell therapy.

    View details for DOI 10.1158/1078-0432.CCR-11-0179

    View details for Web of Science ID 000298133600009

    View details for PubMedID 21998334

  • Thrombospondin 1 accelerates synaptogenesis in hippocampal neurons through neuroligin 1 NATURE NEUROSCIENCE Xu, J., Xiao, N., Xia, J. 2010; 13 (1): 22-24

    Abstract

    In cultured rat hippocampal neurons, we found that thrombospondin 1 (TSP1) increased the speed of synapse formation in young neurons, but not the final density of synapses in mature neurons. TSP1 interacted with neuroligin 1 (NL1) and application of the NL1 extracellular domain blocked TSP1-induced synaptogenesis. Furthermore, knocking down endogenous NL1 inhibited TSP1's effect. Our results indicate that TSP1 accelerates the speed of synaptogenesis through NL1 in hippocampal neurons.

    View details for DOI 10.1038/nn.2459

    View details for Web of Science ID 000273056300008

    View details for PubMedID 19915562

  • PICK1 deficiency causes male infertility in mice by disrupting acrosome formation JOURNAL OF CLINICAL INVESTIGATION Xiao, N., Kam, C., Shen, C., Jin, W., Wang, J., Lee, K. M., Jiang, L., Xia, J. 2009; 119 (4): 802-812

    Abstract

    Protein interacting with C kinase 1 (PICK1) is a peripheral membrane protein involved in protein trafficking, a function that has been well characterized in neurons. Here, we report that male mice deficient in PICK1 are infertile and have a phenotype resembling the human disease globozoospermia. The primary defect in the testes of Pick1-knockout mice was fragmentation of acrosomes in the early stages of spermiogenesis. This fragmentation was followed by defects in nuclear elongation and mitochondrial sheath formation, leading to round-headed sperm, reduced sperm count, and severely impaired sperm motility. We found that PICK1 interacted with Golgi-associated PDZ- and coiled-coil motif-containing protein (GOPC) and the primary catalytic subunit of protein kinase 2 (CK2alpha'), proteins whose deficiencies lead to globozoospermia in mice. PICK1 was highly expressed in round spermatids and localized to Golgi-derived proacrosomal granules. GOPC colocalized with PICK1 in the Golgi region and facilitated formation of PICK1-positive clusters. Furthermore, there was an increase in apoptosis in the seminiferous tubules of Pick1-/- mice, a phenotype also seen in CK2alpha'-deficient mice. Our results suggest that PICK1 is involved in vesicle trafficking from the Golgi apparatus to the acrosome and cooperates with other proteins such as GOPC and CK2alpha' in acrosome biogenesis.

    View details for DOI 10.1172/JCI36230

    View details for Web of Science ID 000264830100019

    View details for PubMedID 19258705

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