Qian Shi, Ph.D.

I am a research faulty in Dr. Manzoor Bhat’s laboratory. I’ve been focused on investigating the pathophysiological mechanisms underlying metabolic disorders, such as diabetes and cancer. There is strong evidence suggesting that the incidence of several types of cancer is increased in patients with diabetes, including leukemia, kidney cancer, colon cancer, and etc. We are particularly interested in the signaling pathways that link cancer and diabetes, among which are the mTOR signaling pathways and reactive oxygen species (ROS).  The mammalian target of Rapamycin (mTOR) is a central player in governing the cellular growth and metabolic homeostasis in response to many growth factors, cellular energy status, and amino-acid levels. The mutations on either TSC1 or TSC2 genes (that regulate mTOR) leads to a rare, multi-system genetic disorder, named tuberous sclerosis complex (TSC), that cause benign tumors to grow in the brain and on other vital organs such kidneys, heart, eyes, lungs, and skin. Because of the ineffectiveness of Rapamycin (inhibitor for mTORC1) in treating TSC, it’s worthy to investigate the alternative therapeutic options as the signaling pathways are not fully understood.

1. The role of mTOR signaling in myelinating glia

TSC severely affects neuronal function, both in CNS and PNS, leading to cognitive impairment, epilepsy, autism, and white matter abnormalities. However, its role in the process of myelination and associated CNS/PNS disorders remains to be fully understood. TSC mutated mice showed reduced myelination, disrupted paranodal domains in myelinated axons, and disorganized unmyelinated Remak bundles. We are particularly interested in elucidating the signaling pathways that linked mTOR to keys molecules in oligodendrocytes development, such as RNA–binding protein Quaking (Qk) and the 155 kDa glial Neurofascin (NfascNF155). This will help design the new generation of inhibitors for treating TSC.

2. The role of mTOR/Nox4 in diabetic nephropathy

The current project aims to investigate the basic molecular mechanism that leads to the understanding of roles of renal proximal tubular epithelial cells in diabetes and in particular diabetic nephropathy (DN), one of the major complications of type 1 diabetes, and provide the novel therapeutic options. We found that high glucose up-regulates Nox4 expression in kidney, enhances NADPH oxidase activity and up-regulates fibronectin. Moreover, high glucose activates the mTOR pathway through enhancing mTORC1/2 activity. However, the precise mechanism by which mTORC2 regulates Nox4 expression/activation is still unknown. We are currently utilizing in vitro and in vivo approaches to establish the importance of possible mTORC2/Nox4 signaling pathway in mediating tubular epithelial cell injury in the diabetic environment, hoping to provide new therapeutic options for treating DN.

• Research & Grants

  1. The role of mTOR signaling in myelinating glia
  2. The role of mTOR/Nox4 in diabetic nephropathy

• Publications

  Q. Shi, Y.Q. Lin, A. Saliba, J. Xie, G.G. Neely and S. Banerjee. Tubulin Polymerization Promoting Protein, Ringmaker, and MAP1B Homolog Futsch Coordinate Microtubule Organization and Synaptic Growth. Front. Cell. Neurosci. 2019. doi: 10.3389/fncel.2019.00192

  Q. Shi, J. Saifetiarova, A.M. Taylor and M.A. Bhat. mTORC1 Activation by Loss of Tsc1 in Myelinating Glia Causes Downregulation of Quaking and Neurofascin 155 Leading to Paranodal Domain Disorganization. Front. Cell. Neurosci. 2018. doi: 10.3389/fncel.2018.00201

  Q. Shi, S. Viswanadhapalli, W. E. Friedrichs, C. Velagapudi, C. Szyndralewiez, S. Bansal, M.A. Bhat, G.G. Choudhury, and H. E. Abboud. Nox4 is a Target for Tuberin Deficiency Syndrome. Sci. Rep. 2018 doi: 10.1038/s41598-018-21838-4

  Niu*, Q. Shi*, W. Zhang, Y. Shu, N. Yang, B, Chen, Q. Wang, X. Zhao, J. Chen, N. Cheng, X. Feng, J. Ji and P. Shen. Caspase-1 cleaves PPARγ for potentiating the pro-tumor action of TAMs. Nat. Comm. 2017, 3;8(1):766 * Equal contribution

  Y. Yao*, Q. Shi*, B. Chen, Q. Wang, X. Li, L. Li, Y. Huang, J. Ji and P. Shen. Identification of caspase-6 as a new regulator of alternatively activated macrophages. J. Bio. Chem. 2016, 291 (33): 17450. * Equal contribution.

  Q. Shi and J. X. Jiang. Connexin Arrests Cell Cycle Through Cytosolic Retention of an E3 Ligase. Mol. & Cell. Onco. 2016 Feb 18;3(2): e1132119.

  Q.D. Zhao, S. Viswanadhapalli, P. Williams, Q. Shi, C. Tan, X. Yi, B. Bhandari, H.E. Abboud. NADPH Oxidase 4 Induces Cardiac Fibrosis and Hypertrophy Through Activating Akt/mTOR and NFκB Signaling Pathways. Circulation. 2015, 131(7): 643-655

  Q. Shi, X. S. Yu, T. W. White, E.A. Bank, S. Gu and J. X. Jiang. Connexin Controls Cell-Cycle Exit and Cell Differentiation by Directly Promoting Cytosolic Localization and Degradation of E3 Ligase Skp2. Dev. Cell. 2015, 35(4):483-496.

  Q. Shi, R. Padmanabhan, C. J. Villegas, S. Gu, and J. X. Jiang. Membrane Topological Structure of System N/A Neural Amino Acid Transporter SNAT4. J. Biol Chem.2011, Sep 14. 286: 38086-38094.

  Q. Shi, E.A. Banks, X.S. Yu, S. Gu, J. Lauer, G.B. Fields, J.X. Jiang. Amino acid residue V362 plays a critical role in maintaining the structure of C-terminus of connexin 50 and in lens epithelial-fiber differentiation. J Biol Chem. 2010, 285(24):18415-18422.

  T. Chen, Q. S. Wang, J. Cui, W. Yang, Q. Shi, J. G. Ji, P. P. Shen, Induction of apoptosis in mice liver by microcystin: a combined transcriptomic, proteomic and simulation strategy. Molecular & Cell Proteomics, 2005 (4):958-974. (Cover story)

  Q. Shi, J. Cui, J. Zhang, F. X. Kong, Z. C. Hua, P. P. Shen, Expression modulation of multiple cytokines in vivo by cyanobacteria blooms extract from Taihu Lake, China. Toxicon 2004 (44):871-879.