Zhenqi Liu

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Primary Appointment

Professor of Medicine, Medicine- Endocrinology and Metabolism

Education

  • Clinical Fellowship, Endocrinology, University of Virginia
  • Fellowship, Endocrinology, Yale University School of Medicine
  • MD, Hunan Medical University
  • Residency, Internal Medicine, Washington Hospital Center

Research Interests

Insulin action, energy metabolism and diabetes complications

Research Description

My laboratory studies insulin action in health and diabetes, with a primary focus on the regulation of insulin action in the vasculature and its relation to insulin's metabolic action and the cardiovascular complications of diabetes.
Areas of investigation include:
- Insulin delivery and action in muscle. In order for insulin to exert its metabolic actions in muscle, it first must be delivered to muscle interstitium. Insulin regulates its own delivery by acting at three discrete step: dilation of the resistance vessels to increase total blood flow, relaxation of pre-capillary arterioles to increase microvascular perfusion and endothelial exchange surface area, and trans-endothelial transport of insulin from plasma to muscle interstitium. These actions are impaired in the insulin resistant states and my laboratory studies insulin actions at all these 3 steps.
- Insulin and IGF-1 signaling in the endothelial cells, particularly the IRS/PI3K/AKT/eNOS pathway.
- Regulation of insulin action in the muscle microcirculation, particularly by the renin-angiotensin system, incretin hormones, and exercise.

Selected Publications

Wang N, Tan AWK, Jahn LA, Hartline L, Patrie JT, Lin S, Barrett EJ, Aylor KW, Liu Z, Vasodilatory Actions of Glucagon-Like Peptide 1 Are Preserved in Skeletal and Cardiac Muscle Microvasculature but Not in Conduit Artery in Obese Humans With Vascular Insulin Resistance., 2020; Diabetes care. 43(3) 634-642. PMID: 31888883 | PMCID: PMC7035589

Love KM, Liu J, Regensteiner JG, Reusch JEB, Liu Z, GLP-1 and insulin regulation of skeletal and cardiac muscle microvascular perfusion in type 2 diabetes., 2020; Journal of diabetes. 12(7) 488-498. PMID: 32274893

Fu Z, Gong L, Liu J, Wu J, Barrett EJ, Aylor KW, Liu Z, Brain Endothelial Cells Regulate Glucagon-Like Peptide 1 Entry Into the Brain via a Receptor-Mediated Process., 2020; Frontiers in physiology. 11() 555. PMID: 32547420 | PMCID: PMC7274078

Liu J, Liu Z, Muscle Insulin Resistance and the Inflamed Microvasculature: Fire from Within., 2019; International journal of molecular sciences. 20(3) . PMID: 30699907 | PMCID: PMC6387226

Tan AWK, Subaran SC, Sauder MA, Chai W, Jahn LA, Fowler DE, Patrie JT, Aylor KW, Basu A, Liu Z, GLP-1 and Insulin Recruit Muscle Microvasculature and Dilate Conduit Artery Individually But Not Additively in Healthy Humans., 2018; Journal of the Endocrine Society. 2(2) 190-206. PMID: 29568814 | PMCID: PMC5841186

Barrett EJ, Liu Z, Khamaisi M, King GL, Klein R, Klein BEK, Hughes TM, Craft S, Freedman BI, Bowden DW, Vinik AI, Casellini CM, Diabetic Microvascular Disease: An Endocrine Society Scientific Statement., 2017; The Journal of clinical endocrinology and metabolism. 102(12) 4343-4410. PMID: 29126250 | PMCID: PMC5718697

Yan F, Yuan Z, Wang N, Carey RM, Aylor KW, Chen L, Zhou X, Liu Z, Direct Activation of Angiotensin II Type 2 Receptors Enhances Muscle Microvascular Perfusion, Oxygenation, and Insulin Delivery in Male Rats., 2017; Endocrinology. 159(2) 685-695. PMID: 29186390 | PMCID: PMC5774251

Chai W, Fu Z, Aylor KW, Barrett EJ, Liu Z, Liraglutide prevents microvascular insulin resistance and preserves muscle capillary density in high-fat diet-fed rats., 2016; American journal of physiology. Endocrinology and metabolism. 311(3) E640-8. PMID: 27436611 | PMCID: PMC5142002

Fu Z, Wu J, Nesil T, Li MD, Aylor KW, Liu Z, Long-term high-fat diet induces hippocampal microvascular insulin resistance and cognitive dysfunction., 2016; American journal of physiology. Endocrinology and metabolism. 312(2) E89-E97. PMID: 27899343 | PMCID: PMC5336564

Zhao L, Fu Z, Wu J, Aylor KW, Barrett EJ, Cao W, Liu Z, Globular adiponectin ameliorates metabolic insulin resistance via AMPK-mediated restoration of microvascular insulin responses., 2015; The Journal of physiology. 593(17) 4067-79. PMID: 26108677 | PMCID: PMC4575587

Zheng C, Liu Z, Vascular function, insulin action, and exercise: an intricate interplay., 2015; Trends in endocrinology and metabolism: TEM. 26(6) 297-304. PMID: 25735473 | PMCID: PMC4450131

Zhao L, Fu Z, Wu J, Aylor KW, Barrett EJ, Cao W, Liu Z, Inflammation-induced microvascular insulin resistance is an early event in diet-induced obesity., 2015; Clinical science (London, England : 1979). () . PMID: 26265791 | PMCID: PMC4613534

Subaran SC, Sauder MA, Chai W, Jahn LA, Fowler DE, Aylor KW, Basu A, Liu Z, GLP-1 at physiological concentrations recruits skeletal and cardiac muscle microvasculature in healthy humans., 2014; Clinical science (London, England : 1979). 127(3) 163-70. PMID: 24552454 | PMCID: PMC4353574

Chai W, Zhang X, Barrett EJ, Liu Z, Glucagon-like peptide 1 recruits muscle microvasculature and improves insulin's metabolic action in the presence of insulin resistance., 2014; Diabetes. 63(8) 2788-99. PMID: 24658303 | PMCID: PMC4113068

Fu Z, Zhao L, Aylor KW, Carey RM, Barrett EJ, Liu Z, Angiotensin-(1-7) recruits muscle microvasculature and enhances insulin's metabolic action via mas receptor., 2014; Hypertension. 63(6) 1219-27. PMID: 24711523 | PMCID: PMC4030711

Zhao L, Fu Z, Liu Z, Adiponectin and insulin cross talk: the microvascular connection., 2014; Trends in cardiovascular medicine. 24(8) 319-24. PMID: 25220977 | PMCID: PMC4252703

Barrett EJ, Liu Z, The endothelial cell: an "early responder" in the development of insulin resistance., 2013; Reviews in endocrine & metabolic disorders. 14(1) 21-7. PMID: 23306779 | PMCID: PMC3594570

Zhao L, Chai W, Fu Z, Dong Z, Aylor KW, Barrett EJ, Cao W, Liu Z, Globular adiponectin enhances muscle insulin action via microvascular recruitment and increased insulin delivery., 2013; Circulation research. 112(9) 1263-71. PMID: 23459195 | PMCID: PMC3971643

Fu Z, Zhao L, Chai W, Dong Z, Cao W, Liu Z, Ranolazine recruits muscle microvasculature and enhances insulin action in rats., 2013; The Journal of physiology. 591(0) 5235-49. PMID: 23798495 | PMCID: PMC3810821

Liu Z, The vascular endothelium in diabetes and its potential as a therapeutic target., 2013; Reviews in endocrine & metabolic disorders. 14(1) 1-3. PMID: 23397463 | PMCID: PMC3594359

Chai W, Dong Z, Wang N, Wang W, Tao L, Cao W, Liu Z, Glucagon-like peptide 1 recruits microvasculature and increases glucose use in muscle via a nitric oxide-dependent mechanism., 2012; Diabetes. 61(4) 888-96. PMID: 22357961 | PMCID: PMC3314347

Sauder MA, Liu J, Jahn LA, Fowler DE, Chai W, Liu Z, Candesartan acutely recruits skeletal and cardiac muscle microvasculature in healthy humans., 2012; The Journal of clinical endocrinology and metabolism. 97(7) E1208-12. PMID: 22508711 | PMCID: PMC3387407

Dong Z, Chai W, Wang W, Zhao L, Fu Z, Cao W, Liu Z, Protein kinase A mediates glucagon-like peptide 1-induced nitric oxide production and muscle microvascular recruitment., 2012; American journal of physiology. Endocrinology and metabolism. 304(2) E222-8. PMID: 23193054 | PMCID: PMC3543568

Barrett EJ, Wang H, Upchurch CT, Liu Z, Insulin regulates its own delivery to skeletal muscle by feed-forward actions on the vasculature., 2011; American journal of physiology. Endocrinology and metabolism. 301(2) E252-63. PMID: 21610226 | PMCID: PMC3154531

Chai W, Liu J, Jahn LA, Fowler DE, Barrett EJ, Liu Z, Salsalate attenuates free fatty acid-induced microvascular and metabolic insulin resistance in humans., 2011; Diabetes care. 34(7) 1634-8. PMID: 21617098 | PMCID: PMC3120177

Chai W, Wang W, Dong Z, Cao W, Liu Z, Angiotensin II receptors modulate muscle microvascular and metabolic responses to insulin in vivo., 2011; Diabetes. 60(11) 2939-46. PMID: 21896931 | PMCID: PMC3198098

Wang N, Ko SH, Chai W, Li G, Barrett EJ, Tao L, Cao W, Liu Z, Resveratrol recruits rat muscle microvasculature via a nitric oxide-dependent mechanism that is blocked by TNFα., 2010; American journal of physiology. Endocrinology and metabolism. 300(1) E195-201. PMID: 20978231 | PMCID: PMC3023212

Liu J, Jahn LA, Fowler DE, Barrett EJ, Cao W, Liu Z, Free fatty acids induce insulin resistance in both cardiac and skeletal muscle microvasculature in humans., 2010; The Journal of clinical endocrinology and metabolism. 96(2) 438-46. PMID: 21047922 | PMCID: PMC3048322