Bio

Bio


My overall research interests are liver biology, pathology, and therapeutics. The medical education in China has provided me a comprehensive perspective of human disease and treatment. As a graduate student in University of Kansas Medical Center, I gained expertise in using transgenic mouse models to study autophagy in adipose-liver axis, liver lipid metabolism, and xenobiotic-induced liver steatosis and injury. As a postdoc my current research in Stanford University focuses on non-alcoholic steatohepatitis and hepatocellular carcinoma.

Honors & Awards


  • Recipient of Biomedical Research Training Program, University of Kansas Medical Center (2017)

Boards, Advisory Committees, Professional Organizations


  • Trainee Member, AASLD (2019 - Present)

Professional Education


  • Bachelor of Arts, Central China Normal University (2011)
  • Bachelor of Medicine, Unlisted School (2011)
  • Doctor of Philosophy, University of Kansas (2018)

Stanford Advisors


Research & Scholarship

Lab Affiliations


Publications

All Publications


  • Impaired TFEB-Mediated Lysosome Biogenesis and Autophagy Promote Chronic Ethanol-Induced Liver Injury and Steatosis in Mice. Gastroenterology Chao, X., Wang, S., Zhao, K., Li, Y., Williams, J. A., Li, T., Chavan, H., Krishnamurthy, P., He, X. C., Li, L., Ballabio, A., Ni, H. M., Ding, W. X. 2018; 155 (3): 865–79.e12

    Abstract

    Defects in lysosome function and autophagy contribute to the pathogenesis of alcoholic liver disease. We investigated the mechanisms by which alcohol consumption affects these processes by evaluating the functions of transcription factor EB (TFEB), which regulates lysosomal biogenesis.We performed studies with GFP-LC3 mice, mice with liver-specific deletion of TFEB, mice with disruption of the transcription factor E3 gene (TFE3-knockout mice), mice with disruption of the Tefb and Tfe3 genes (TFEB and TFE3 double-knockout mice), and Tfebflox/flox albumin cre-negative mice (controls). TFEB was overexpressed from adenoviral vectors or knocked down with small interfering RNAs in mouse livers. Mice were placed on diets of regular ethanol feeding plus an acute binge to induce liver damage (ethanol diet); some mice also were given injections of torin-1, an inhibitor of the kinase activity of the mechanistic target of rapamycin (mTOR). Liver tissues were collected and analyzed by immunohistochemistry, immunoblots, and quantitative real-time polymerase chain reaction to monitor lysosome biogenesis. We analyzed levels of TFEB in liver tissues from patients with alcoholic hepatitis and from healthy donors (controls) by immunohistochemistry.Liver tissues from mice on the ethanol diet had lower levels of total and nuclear TFEB compared with control mice, and hepatocytes had decreased lysosome biogenesis and autophagy. Hepatocytes from mice on the ethanol diet had increased translocation of mTOR into lysosomes, resulting in increased mTOR activation. Administration of torin-1 increased liver levels of TFEB and decreased steatosis and liver injury induced by ethanol. Mice that overexpressed TFEB in the liver developed less severe ethanol-induced liver injury and had increased lysosomal biogenesis and mitochondrial bioenergetics compared with mice carrying a control vector. Mice with knockdown of TFEB and TFEB-TFE3 double-knockout mice developed more severe liver injury in response to the ethanol diet than control mice. Liver tissues from patients with alcohol-induced hepatitis had lower nuclear levels of TFEB than control tissues.We found that ethanol feeding plus an acute binge decreased hepatic expression of TFEB, which is required for lysosomal biogenesis and autophagy. Strategies to block mTOR activity or increase levels of TFEB might be developed to protect the liver from ethanol-induced damage.

    View details for PubMedID 29782848

  • Impaired Fasting-Induced Adaptive Lipid Droplet Biogenesis in Liver-Specific Atg5-Deficient Mouse Liver Is Mediated by Persistent Nuclear Factor-Like 2 Activation. The American journal of pathology Li, Y., Chao, X., Yang, L., Lu, Q., Li, T., Ding, W. X., Ni, H. M. 2018; 188 (8): 1833–46

    Abstract

    Lipid droplets (LDs) are intracellular organelles that store neutral lipids as energy reservoir. Recent studies suggest that autophagy is important in maintaining the homeostasis of intracellular LDs by either regulating the biogenesis of LDs, mobilization of fatty acids, or degradation of LDs in cultured cells. Increasing evidence also supports a role of autophagy in regulating glucose and lipid metabolism in vivo in mammals. In response to fasting/starvation, lipids are mobilized from the adipose tissue to the liver, which increases the number of intracellular LDs and stimulates fatty acid oxidation and ketogenesis. However, it is still controversial and unclear how impaired autophagy in hepatocytes affects the biogenesis of LDs in mouse livers. In the present study, it was demonstrated that hepatic autophagy-deficient (L-Atg)5 knockout mice had impaired adaptation to fasting-induced hepatic biogenesis of LDs. The maladaptation to fasting-induced hepatic biogenesis of LDs in L-Atg5 knockout mouse livers was not due to hepatic changes of de novo lipogenesis, secretion of very-low-density lipoprotein or fatty acid β-oxidation, but it was due to persistent nuclear factor-like 2 activation because biogenesis of LDs restored in L-Atg5/nuclear factor-like 2 double-knockout mice.

    View details for DOI 10.1016/j.ajpath.2018.04.015

    View details for PubMedID 29803835

    View details for PubMedCentralID PMC6099336

  • Adipose tissue autophagy and homeostasis in alcohol-induced liver injury. Liver research Li, Y., Ding, W. X. 2017; 1 (1): 54–62

    Abstract

    Alcohol consumption leads to injury in multiple organs and systems, including the liver, brain, heart, skeletal muscle, pancreas, bone, immune system, and endocrine system. Emerging evidence indicates that alcohol also promotes adipose tissue dysfunction, which may contribute to injury progression in other organs and systems. Autophagy is a lysosomal degradation pathway that has been shown to regulate adipose tissue homeostasis and adipogenesis. Increasing evidence also demonstrates that alcohol consumption affects autophagy in multiple tissues. This review summarizes current knowledge regarding the effect of autophagy on adipose tissue and its potential roles in alcohol-induced adipose tissue atrophy as well as its contribution to alcohol-induced liver injury.

    View details for DOI 10.1016/j.livres.2017.03.004

    View details for PubMedID 29109891

    View details for PubMedCentralID PMC5669268

  • Inhibition of insulin/PI3K/AKT signaling decreases adipose Sortilin 1 in mice and 3T3-L1 adipocytes. Biochimica et biophysica acta. Molecular basis of disease Li, J., Chen, C., Li, Y., Matye, D. J., Wang, Y., Ding, W. X., Li, T. 2017; 1863 (11): 2924–33

    Abstract

    Sortilin 1(Sort1) is a vesicle trafficking receptor that mediates protein sorting in the endocytic and exocytic pathways. Sort1 is a component of the GLUT4 storage vesicles in adipocytes and is also involved in the regulation of adipogenesis. Sort1 protein is reduced in adipose of obese mice and humans, but the underlying cause is not fully understood. Here we report that insulin/PI3K/AKT signaling cascade critically regulates adipose Sort1 protein abundance. Administration of a PI3K inhibitor rapidly decreased Sort1 protein but not mRNA in adipose of chow-fed mice. In 3T3-L1 adipocytes, serum-starvation or inhibition of the PI3K/AKT signaling also decreased Sort1 protein without affecting Sort1 mRNA expression. Sort1 protein downregulation upon PI3K inhibition was blocked by pretreatment of MG132 but not Bafilomycin A1, suggesting that PI3K inhibition caused Sort1 degradation via the proteasome pathway. Using a phospho-specific Sort1 antibody, we showed that endogenous Sort1 was phosphorylated at S825 adjacent to the DXXLL sorting motif on the cytoplasmic tail. We demonstrated that mutagenesis that abolished Sort1 S825 phosphorylation decreased insulin-stimulated Sort1 localization on the plasma membrane and Sort1 protein stability in 3T3-L1 adipocytes. However, endogenous Sort1 phosphorylation at S825 was not affected by insulin stimulation or by inhibition of PI3K. In conclusion, this study revealed an important role of insulin signaling in regulating adipose Sort1 protein stability, and further suggests that impaired insulin signaling may underlie reduced adipose Sort1 in obesity. The cellular events downstream of insulin/PI3K/AKT signaling that mediates insulin regulation of Sort1 stability requires further investigation.

    View details for DOI 10.1016/j.bbadis.2017.08.012

    View details for PubMedID 28844948

    View details for PubMedCentralID PMC5659898

  • Recycling the danger via lipid droplet biogenesis after autophagy AUTOPHAGY Li, Y., Zong, W., Ding, W. 2017; 13 (11): 1995–97

    Abstract

    Fatty acids are an important cellular energy source under starvation conditions. However, excessive free fatty acids (FFAs) in the cytoplasm cause lipotoxicity. Therefore, it is important to understand the mechanisms by which cells mobilize lipids and maintain a homeostatic level of fatty acids. Recent evidence suggests that cells can break down lipid droplets (LDs), the intracellular organelles that store neutral lipids, via PNPLA2/adipose triglyceride lipase and a selective type of macroautophagy/autophagy termed lipophagy, to release FFAs under starvation conditions. FFAs generated from LD catabolism are either transported to mitochondria for β-oxidation or converted back to LDs. The biogenesis of LDs under starvation conditions is mediated by autophagic degradation of membranous organelles and requires diacylglycerol O-acyltransferase 1, which serves as an adaptive cellular protective mechanism against lipotoxicity.

    View details for DOI 10.1080/15548627.2017.1371394

    View details for Web of Science ID 000418882900015

    View details for PubMedID 28873005

    View details for PubMedCentralID PMC5788485

  • Impaired Rab7 and Dynamin2 Block Fat Turnover by Autophagy in Alcoholic Fatty Livers. Hepatology communications Li, Y., Ding, W. X. 2017; 1 (6): 473–76

    View details for DOI 10.1002/hep4.1067

    View details for PubMedID 29124250

    View details for PubMedCentralID PMC5673279

  • Does Genetic Loss of Immunoglobulin A Have No Impact on Alcoholic Liver Disease? Alcoholism, clinical and experimental research Li, Y., Ding, W. X. 2017; 41 (1): 20–22

    View details for DOI 10.1111/acer.13270

    View details for PubMedID 28042659

    View details for PubMedCentralID PMC5215837

  • A cell-based quantitative high-throughput image screening identified novel autophagy modulators PHARMACOLOGICAL RESEARCH Li, Y., McGreal, S., Zhao, J., Huang, R., Zhou, Y., Zhong, H., Xia, M., Ding, W. 2016; 110: 35–49

    Abstract

    Macroautophagy is a major cellular degradation pathway for long-lived proteins and cellular organelles to maintain cellular homeostasis. Reduced autophagy has been implicated in neurodegenerative diseases, metabolic syndrome, and tumorigenesis. In contrast, increased autophagy has been shown to protect against tissue injury and aging. Here we employed a cell-based quantitative high-throughput image screening (qHTS) for autophagy modulators using mouse embryonic fibroblasts (MEFs) that are stably expressing GFP-LC3. The library of pharmacologically active compounds (LOPAC) was used to screen for the autophagy modulators in compounds alone or in combination with the lysosome inhibitor chloroquine (CQ). The GFP-LC3 puncta were then quantified to measure autophagic flux. The primary screening revealed 173 compounds with efficacy more than 40%. These compounds were cherry-picked and re-tested at multiple different concentrations using the same assay. A number of novel autophagy inducers, inhibitors, and modulators with dual-effects on autophagy were identified from the cherry-pick screening. Interestingly, we found a group of compounds that induce autophagy are related to dopamine receptors and are commonly used as clinical psychiatric drugs. Among them, indatraline hydrochloride (IND), a dopamine inhibitor, and chlorpromazine hydrochloride (CPZ) and fluphenazine dihydrochloride (FPZ), two dopamine receptor antagonists, were further evaluated. We found that FPZ-induced autophagy through mTOR inhibition but IND and CPZ induced autophagy in an mTOR-independent manner. Our data suggest that image-based autophagic flux qHTS can efficiently identify autophagy inducers and inhibitors.

    View details for DOI 10.1016/j.phrs.2016.05.004

    View details for Web of Science ID 000379557800004

    View details for PubMedID 27168224

    View details for PubMedCentralID PMC4995889

  • Nrf2 but not autophagy inhibition is associated with the survival of wild-type epidermal growth factor receptor non-small cell lung cancer cells. Toxicology and applied pharmacology Zhou, Y., Li, Y., Ni, H. M., Ding, W. X., Zhong, H. 2016; 310: 140–49

    Abstract

    Non-small cell lung cancer (NSCLC) is one of the most common malignancies in the world. Icotinib and Gefitinib are two epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) that have been used to treat NSCLC. While it is well known that mutations of EGFR can affect the sensitivity of NSCLC to the EGFR-TKI, other mechanisms may also be adopted by lung cancer cells to develop resistance to EGFR-TKI treatment. Cancer cells can use multiple adaptive mechanisms such as activation of autophagy and Nrf2 to protect against various stresses and chemotherapeutic drugs. Whether autophagy or Nrf2 activation contributes to the resistance of NSCLC to EGFR-TKI treatment in wild-type EGFR NSCLC cells remains elusive. In the present study, we confirmed that Icotinib and Gefitinib induced apoptosis in EGFR mutant HCC827 but not in EGFR wild-type A549 NSCLC cells. Icotinib and Gefitinib did not induce autophagic flux or inhibit mTOR in A549 cells. Moreover, suppression of autophagy by chloroquine, a lysosomal inhibitor, did not affect Icotinib- or Gefitinib-induced cell death in A549 cells. In contrast, Brusatol, an Nrf2 inhibitor, significantly suppressed the cell survival of A549 cells. However, Brusatol did not further sensitize A549 cells to EGFR TKI-induced cell death. Results from this study suggest that inhibition of Nrf2 can decrease cell vitality of EGFR wild-type A549 cells independent of autophagy.

    View details for DOI 10.1016/j.taap.2016.09.010

    View details for PubMedID 27639429

    View details for PubMedCentralID PMC5470646

  • A Gene Transcription Program Decides the Differential Regulation of Autophagy by Acute Versus Chronic Ethanol? ALCOHOLISM-CLINICAL AND EXPERIMENTAL RESEARCH Li, Y., Ding, W. 2016; 40 (1): 47–49

    View details for DOI 10.1111/acer.12931

    View details for Web of Science ID 000368140900004

    View details for PubMedID 26727521

    View details for PubMedCentralID PMC5533655

  • Chronic Deletion and Acute Knockdown of Parkin Have Differential Responses to Acetaminophen-induced Mitophagy and Liver Injury in Mice. The Journal of biological chemistry Williams, J. A., Ni, H. M., Haynes, A., Manley, S., Li, Y., Jaeschke, H., Ding, W. X. 2015; 290 (17): 10934–46

    Abstract

    We previously demonstrated that pharmacological induction of autophagy protected against acetaminophen (APAP)-induced liver injury in mice by clearing damaged mitochondria. However, the mechanism for removal of mitochondria by autophagy is unknown. Parkin, an E3 ubiquitin ligase, has been shown to be required for mitophagy induction in cultured mammalian cells following mitochondrial depolarization, but its role in vivo is not clear. The purpose of this study was to investigate the role of Parkin-mediated mitophagy in protection against APAP-induced liver injury. We found that Parkin translocated to mitochondria in mouse livers after APAP treatment followed by mitochondrial protein ubiquitination and mitophagy induction. To our surprise, we found that mitophagy still occurred in Parkin knock-out (KO) mice after APAP treatment based on electron microscopy analysis and Western blot analysis for some mitochondrial proteins, and Parkin KO mice were protected against APAP-induced liver injury compared with wild type mice. Mechanistically, we found that Parkin KO mice had decreased activated c-Jun N-terminal kinase (JNK), increased induction of myeloid leukemia cell differentiation protein (Mcl-1) expression, and increased hepatocyte proliferation after APAP treatment in their livers compared with WT mice. In contrast to chronic deletion of Parkin, acute knockdown of Parkin in mouse livers using adenovirus shRNA reduced mitophagy and Mcl-1 expression but increased JNK activation after APAP administration, which exacerbated APAP-induced liver injury. Therefore, chronic deletion (KO) and acute knockdown of Parkin have differential responses to APAP-induced mitophagy and liver injury in mice.

    View details for DOI 10.1074/jbc.M114.602284

    View details for PubMedID 25752611

    View details for PubMedCentralID PMC4409255

  • Basal Autophagy and Feedback Activation of Akt Are Associated with Resistance to Metformin-Induced Inhibition of Hepatic Tumor Cell Growth. PloS one Yang, H., Peng, Y. F., Ni, H. M., Li, Y., Shi, Y. H., Ding, W. X., Fan, J. 2015; 10 (6): e0130953

    Abstract

    While accumulating evidence has shown that the use of the diabetic drug metformin may be beneficial against various tumors in some epidemiological studies, a few studies failed to show the same beneficial effects. The molecular and cellular mechanisms for these conflicting observations are not clear. In this study, we compared the inhibitory effects of cell growth by metformin on several hepatic tumor cell lines: SMMC-7721, HCC-97L, HCC-LM3 and HepG2. While metformin inhibited cell growth in all these cells, we found that SMMC-7721, HCC-97L and HCC-LM3 cells were more resistant than HepG2 cells. Mechanistically, we found that metformin inhibited mTOR in all these hepatic tumor cells. However, SMMC-7721 cells had higher levels of basal autophagy and mTORC2-mediated feedback activation of Akt than HepG2 cells, which may render SMMC-7721 cells to be more resistant to metformin-induced inhibition of cell growth. Similarly, HCC-97L and HCC-LM3 cells also had higher feedback activation of AKT than HepG2 cells, which may also account for their resistance to metformin-induced inhibition of cell growth. Therefore, the various basal autophagy and mTOR activity in different cancer cells may contribute to the controversial findings on the use of metformin in inhibition of cancers in humans.

    View details for DOI 10.1371/journal.pone.0130953

    View details for PubMedID 26111001

    View details for PubMedCentralID PMC4482411

  • Autophagy in alcohol-induced multiorgan injury: mechanisms and potential therapeutic targets. BioMed research international Li, Y., Wang, S., Ni, H. M., Huang, H., Ding, W. X. 2014; 2014: 498491

    Abstract

    Autophagy is a genetically programmed, evolutionarily conserved intracellular degradation pathway involved in the trafficking of long-lived proteins and cellular organelles to the lysosome for degradation to maintain cellular homeostasis. Alcohol consumption leads to injury in various tissues and organs including liver, pancreas, heart, brain, and muscle. Emerging evidence suggests that autophagy is involved in alcohol-induced tissue injury. Autophagy serves as a cellular protective mechanism against alcohol-induced tissue injury in most tissues but could be detrimental in heart and muscle. This review summarizes current knowledge about the role of autophagy in alcohol-induced injury in different tissues/organs and its potential molecular mechanisms as well as possible therapeutic targets based on modulation of autophagy.

    View details for DOI 10.1155/2014/498491

    View details for PubMedID 25140315

    View details for PubMedCentralID PMC4124834

  • Down-regulated KLF17 expression is associated with tumor invasion and poor prognosis in hepatocellular carcinoma. Medical oncology (Northwood, London, England) Liu, F. Y., Deng, Y. L., Li, Y., Zeng, D., Zhou, Z. Z., Tian, D. A., Liu, M. 2013; 30 (1): 425

    Abstract

    Although the role of Krüppel-like factor 17 (KLF17) in regulating epithelial-mesenchymal transition (EMT) has been explored in breast cancer, its influence on primary hepatocellular carcinoma (HCC) remains unclear. This study aims to investigate the expression status of KLF17 in hepatocellular carcinoma (HCC) and the correlation between KLF17 expression and metastatic potential of HCC. KLF17 expression in HCC and adjacent liver tissues was studied by real-time PCR and Western blot, and the relationship between KLF17 expression and the clinicopathological features of HCC was evaluated in 60 patients. By using RNA interference technique, the correlation of KLF17 expression and metastatic potential was investigated by down-regulating KLF17 expression in HepG2 cells, and the effects of KLF17 down-regulation on cell migration, and invasion were then analyzed. Furthermore, the correlation between KLF17 expression and the surgical outcomes of a cohort of HCC patients was analyzed. Reduced expression of KLF17 is associated with a short survival time in clinical patients (P = 0.034). Low KLF17 expression is related to tumor T stage (P = 0.045), tumor size (P = 0.027), lymph node stage (P = 0.030), M stage (P = 0.048), and portal vein tumor thrombosis significantly in HCC. Reduced expression of KLF17 promoted motility and invasion ability of HepG2 cells and changed the expression of E-cadherin, ZO-1, Snai1, and vimentin (genes are associated with EMT). Overall, these findings suggest a repressing role of KLF17 in tumor invasion and a new prognostic indicator in directing therapy. It deserves further exploration.

    View details for DOI 10.1007/s12032-012-0425-3

    View details for PubMedID 23325444

  • [2010 guideline for the management of hepatocellular carcinoma recommended by the American Association for the Study of Liver Diseases]. Zhonghua gan zang bing za zhi = Zhonghua ganzangbing zazhi = Chinese journal of hepatology He, X. X., Li, Y., Ren, H. P., Tian, D. A., Lin, J. S. 2011; 19 (4): 249–50

    View details for PubMedID 21805732