Gokul C Das, Ph. DDepartment of Medicine

Baylor College of Medicine, Houston, TX

4th World Virology CongressSan Antonio

October 6-8, 2014

HCV is considered as a metabolic disease

Over 170 million people world wide is infected with HCV, are at high risk for hepC, liver cirrhosis, liver cancer or type II diabetes.

Induces insulin resistance (IR); IR accelerates the progression of liver disease and makes treatment difficult

Needs a successful vaccine and/or an well- tolerated and cost-effective treatment strategy.

Questions?

How does chronic HCV infection induce insulin resistance (IR)?

How does IR affect the outcome of IFN-based therapeutic response?

How to develop a well-tolerated and cost effective treatment strategy?

DISRUPTION IN INSULIN SIGNALING

DISTURBANCE IN GLUCOSE

HOMEOSTASIS

IDENTIFY mi RNA TARGETSAND PATHWAYS INVOLVED

HUMANIZED MICE MODEL

DEVELOPMENT OF INSULIN RESISTANCE AND

MOLECULAR BASIS OF IRAND IFN RESPONSE

OUR GOALS AND STRATEGY

THERAPEUTIC DEVELOPMENT

CHRONIC INFECTION IN LIVER CELL LINE

(Huh. HCV2a)

Plasma Membrane

PI-3K GSK-3 GlycogenSynthase(GS)

Insulin

Beclin 1 Bcl-2/Bcl-XL

Apoptosis

IRc

Insulin

IRS-1/2

GlutVesicle

Autophagy

Glut

Akt473

Glycogen Synthesis

Glucoseuptake

mTORC1/C2

IRc

Insulin signaling pathway

Reduced glucose uptake in infected Cells

0

50

100

150

200

250

300

350

400

450

500

Huh Huh+Ins Huh.HCV Huh.HCV+Ins

3H

-de

ox

y-2

-glu

co

se

(C

PM

X1

0-2

)

*

*

*

*

MOI: 0 2 10

.03 .05 .06 .16 .47 1.22

Fig. 5C

Huh Huh.HCV 50 100 50 100

IRS-1 .06 .03 .99 1.01p-IRS-1 .07 .04 1.22 .90

p- Akt .36 .54 1.38 1.92 p-GSK-3α .06 .03 .05 .04 p-GSK-3β 1.49 1.37 1.31 1.20

MOI: 0 1 2

Atg12-Atg5 .65 .78 1.30 1.38 1.32 2.61Beclin1 .15 .27 1.16 1.05 1.49 2.44

Inhibition of autophagy reduces IRS-1Ser312 and GS Ser641 phosphorylation

AMPK-mTOR pathway: AMPK phosphorylation and inhibition by IFNα

AMPK ---- 0.34 0.54 0.48 0.35 0.25 0.23 0.48 0.52P-AMPK ---- 0.23 0.19 1.40 0.53 0.80 0.80 0.01 0.01Ratio 0.60 0.40 2.90 1.60 3.20 3.50 0.02 0.02

S- 0.31 .08 1.45 0.77 0.71

IRc

PI-3K

mTORmTOR

TYK2JAK1

IRS-1/2

IRS-1/2

PI-3KAkt

Akt

GSK-3α/BGlycogen synthase

IFN R1/2

Autophagy

Glucoseuptake

IFN R1/2

TYK2 JAK1

STATs

ISG

Insulin IFN IFN

Protein Translation

Cross talk between Insulin and IFN signaling

Fig.8. Strategy for inhibition of major target proteins (Akt, Gsk-3, mTOR, AMPK) and effect on the pathway

Summary and Discussion HCV infected cells show disruption in glucose

homeostasis (reduced glucose uptake and inactivation of GS by Ser641) and it is activated within 2 weeks

Insulin signaling pathway ( IRS-1-PI-3K-Akt-GSK-3) is dysregulated

Autophagy is linked with IR and inhibition of autophagy inhibits IRS-1, GSK-3 beta and GS ser 641 phosphorylation

Key proteins from all three major pathways interact Phosphorylation of GSK-3 beta, AMPK or mTOR are all

inhibited by IFN-alpha suggesting as potential therapeutic targets.

Phosphorylation of GSK-3 beta, AMPK and mTOR

AcknowledgementBlaine Hollinger, MD

David Gallardo Charles Rice, MDWei Chen Robert Purcell, MDCai Guangquo Stan Lemon, MDLiping Bai, MD T. Wakita, MDKarina Zheng, MD George Luo, MD Xianfan Huang, Ph.D

Funding:Eugene B Casey FundCarpenter fund Gulf Coast Regional Blood Center, Houston