Persistent organic pollutants and metabolic syndrome;

Clinical implications

Hong Kyu Lee, M.D.Hong Kyu Lee, M.D.

Bumsuk Prof. of Medicine, Eulji UniversityBumsuk Prof. of Medicine, Eulji University

Prof. Emeritus, Seoul National UniversityProf. Emeritus, Seoul National University

June 2010, KSMRM, Korea

Lee HK et al. BBA General Subject 2010Kwak SH et al. J Diab Invest 2010 (in press)

1983 1985 1987 1989 1991 1993 1995 1997 1999 20010

10

20

30

Diabetes

Infection

IHD

Year

Dea

th R

ate

per

100,

000

po

pu

lati

on

Death rate per 100,000 population

Data source: Korea National Statistical Office http://www.nso.go.kr

Diabetes epidemic in Korea

Obesity and Diabetes in the Developing World — A Growing Challenge. Why?

Hossain P, Kawar, B, and Nahas ME. NEJM 356:213-215 2007

Short history of search for cause

1. Yallow and Berson found high serum insulin in type 2 diabetes, thus insulin resistance : common underlying biochemical abnormality

2. Molecular approach (insulin receptor and post-receptor mechanisms) was not successful

3. Epidemiologic approach by establishing a disease entity (syndrome X) proposed by Reaven (1988)

4. WHO experts gave new name; metabolic syndrome (1998)

Underlying cause(s)

DiabetesDiabetes

HypertensionHypertensionObesityObesity

DyslipidemiaDyslipidemiaAtherosclerosisAtherosclerosis

Syndrome X=

Metabolic syndrome

Cause(s)

Concept of metabolic syndrome

Theories on the causes of insulin resistance

1. Genetic cause (thrifty genotype hypothesis. Neel JV, 1962)

2. Fetal malnutrition (thrifty phenotype hypothesis. Barker DJP and Hales CN, 1992)

3 Mitochondrial dysfunction (Lee HK et al, 2006)

4. Environmental chemicals (Baillie-Hamilton PF, 2002) and POPs (Lee DH et al, 2006)

Kadowaki T et al. J Clin Invest 116:1784-1792,

2006

Mitochondrial dysfunctionMitotoxins

Why mitochondria in diabetes?(KDA autumn meeting, 1994)

• As genes did not change, something in the environment should have caused it

• Causative agent(s) should be not infectious• Introduced by industrialization/

westernization/ coca-cola-rization?• Diabetogenic drug, streptozotocin damaged

cell as NO donor• Mitochondrion is most vulnerable target of

free radicals

• mtDNA 0.41 +/- 0.06 (n = 12) pmol of 8-OHdG per ug

• nDNA 0.025+/- 0.004 (n = 4)

• 16 times lower level of 8-OHdG in nuclear DNA

• Oxidative damage should leave clue in mtDNA

• What the hell is mitochondria and its DNA?

MH Chung studied OGG at JCC and told me free radical damage is 10 times higher in mtDNA

Richter C, Park JW, Ames BNPNAS USA, 1988

Our studies linking insulin resistance and mitochondrial dysfunction

• mtDNA density decrease precede the development of diabetes in Yochon cohort, 1998

• Medical student cohort (KU Lee et al)• Birth weight and mtDNA density (YY Lee, YA Sung):

thrifty phenotype hypothesis• mtDNA variations and insulin resistance (Asians)

16189 T>C,

haplogroups N9a (resistant)

haplogroups B and F (sensitive)

(In collaboration with M Tanaka et al, K Nanjo et al)

Science, 2003

The association of mitochondrial dysfunction and insulin resistance is

established, but the cause–effect relationship is not. See http://videocast.nih.gov/PastEvent.asp?c=998

Maternal malnutrition

•Low taurine level•Low level of methyl-donors•Depletion of nucleotide pool•Increased oxidative stress

•Genomic imprinting

Poor initial condition of mitochondrial function

Fetal malnutrition

Poor response to insulin action

Beta-cell

Impaired insulin secretion

ncDNA, mtDNA

Environment•Westernized life style

•Aging•Drugs, toxins

Diabetes

Nutr Biochem Review, 2004, NYAS 2005,

Revised 2009

Hypertension Insulin resistance/obesity

Sympathetic overactivity?

CNS/ANS Muscle/Liver

Cognitive function

Neurodegenerative diseases Cancers

Environmental factors causing mitochondrial dysfunction

We looked for a clue in United States• Obesity epidemic is most rampant in

Mississippi valley; agriculture• Mitochondrial toxin(s) in agriculture?• Corn is used in coca cola and fast foods

Known to inhibit respiration of gill of a shellfish

Herbicides inhibit photosystem II Q binding site of chloroplast thylakoid membrane (photosynthesis)

A

BControl Atrazine 3 mg/L

Control Atrazine 3 mg/L

0 1 2 3 4 50

100

200

300

ATZ (0.3mg/L)

350

450

550

650

Control

ATZ (3mg/L)

Months

Bo

dy

wei

gh

t (g

)

High fat diet

Muscle

Hepatocyte

Effect of Chronic Exposure of Atrazine on the Mitochondrial Function and Insulin Resistance in Rats Lim S, Park KS, Cho YM, Lee KU, KimPak YM, Lee HK, (PLoS One, April 13, 2009).

Basal I II & III IV0

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Figure S1. Lim S, KimPak Y et. al. PLoS One, 2009

Atrazine inhibited respiration of mouse liver

Atrazine (3mg/l) Control

Visceral fat - High fat diet group -

Weight = 559 g Weight = 564 g

Theories on the causes of insulin resistance

1. Genetic cause (thrifty genotype hypothesis. Neel JV, 1962)

2. Fetal malnutrition (thrifty phenotype hypothesis. Barker DJP and Hales CN, 1992)

3 Mitochondrial dysfunction (Lee HK et al, 2006)

4. Environmental chemicals (Baillie-Hamilton PF, 2002) and POPs (Lee DH et al, 2006)

BAILLIE-HAMILTON PF. J ALTERNAT COMPLEMENT MED. 8:185–192, 2002

Duk Hee Lee, an epidemiologist was looking for environmental factor(s)

because of elevated gamma glutaryl transferase (GGT) was predictive of

diabetes development.

Reasoned environmental toxins would cause this elevation.

Special thanks for letting me use her slides.

109 109

111

112

114

10

11

12

14 14

5759

64

74

83SBP (mmHg) Insulin, uU/L TG (mg/dl)

103

107

110

116115

LCL-C (mg/dl)54

53 53

51

54HDL-C (mg/dl)

5.7

6

6.2

6.4 6.5WBC(109/L)

Cross-sectional association Cross-sectional association between serum GGT and CVD risk factors II (CARDIA data)between serum GGT and CVD risk factors II (CARDIA data)

GGT

GGT

GGT GGT

GGTGGT

Lee DH, et al. Clin Chem 2003;49:1358-66

1. Pesticides aldrin, chlordane, DDT, dieldrin, endrin, heptachlor, hexachlorobenzene,

mirex, toxaphene, chlordecone, alpha -hexachlorocyclohexane, beta hexachlorocyclohexane, lindane, pentachlorobenzene),

2. Industrial chemicals hexachlorobenzene, polychlorinated biphenyls (PCBs), hexabromobiphenyl,

hexabromodiphenyl ether and heptabromodiphenyl ether, pentachlorobenzene, perfluorooctane sulfonic acid, its salts and perfluorooctane sulfonyl fluoride, tetrabromodiphenyl ether and pentabromodiphenyl ether

3. By-products hexachlorobenzene; polychlorinated dibenzo-p-dioxins polychlorinated dibenzofurans (PCDD/PCDF), and PCBs, alpha hexachlorocyclohexane, beta hexachlorocyclohexane and pentachlorobenzene].

1. Pesticides aldrin, chlordane, DDT, dieldrin, endrin, heptachlor, hexachlorobenzene,

mirex, toxaphene, chlordecone, alpha -hexachlorocyclohexane, beta hexachlorocyclohexane, lindane, pentachlorobenzene),

2. Industrial chemicals hexachlorobenzene, polychlorinated biphenyls (PCBs), hexabromobiphenyl,

hexabromodiphenyl ether and heptabromodiphenyl ether, pentachlorobenzene, perfluorooctane sulfonic acid, its salts and perfluorooctane sulfonyl fluoride, tetrabromodiphenyl ether and pentabromodiphenyl ether

3. By-products hexachlorobenzene; polychlorinated dibenzo-p-dioxins polychlorinated dibenzofurans (PCDD/PCDF), and PCBs, alpha hexachlorocyclohexane, beta hexachlorocyclohexane and pentachlorobenzene].

NHANES 1999-2002 had measured about 50 POPs in a random sample of US population

Polychlorinated Dibenzo-p-dioxins (PCDDs) Polychlorinated Dibenzo-p-dioxins (PCDDs) Polychlorinated Dibenzofurans (PCDFs)Polychlorinated Dibenzofurans (PCDFs) Dioxin-like PCBsDioxin-like PCBs Non-dioxin-like PCBsNon-dioxin-like PCBs Organochlorine PesticidesOrganochlorine Pesticides

POPs which were detected among POPs which were detected among 80% of subjects 80% of subjects

• 2,2’,4,4’,5,5’-hexachlorobiphenyl (PCB153) : 2,2’,4,4’,5,5’-hexachlorobiphenyl (PCB153) : banned banned • 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin• 1,2,3,4,6,7,8,9-octachlorodibenzo-p-dioxin1,2,3,4,6,7,8,9-octachlorodibenzo-p-dioxin• oxychlordane : oxychlordane : bannedbanned• p,p’-DDE : p,p’-DDE : bannedbanned• trans-nonachlor : trans-nonachlor : bannedbanned

Adjusted odds ratios of prevalent diabetes according to categories of sum of 6 POPs

1

14 14.7

38.3 37.7

05

10152025303540

>25% 25-<50%

50-<75%

75-<90%

90%+

Sum of 6 POPs

Adjusted odds ratio

Lee DH, et al. Diabetes Care 2006

Interaction between obesity and POPs on the risk of prevalent diabetes

Lee DH, et al. Diabetes Care 2006

0

5

10

15

20

25

3035

40

45

<25 25-29 >=30

G1G2

G3G4

G5

Body mass index

Sum of 6 POPs

Prevalence of diabetes (%)

Lee DH et al. Diabetes Care 2007;30:622-8

Association between POPs and HOMA-IR among non-diabetics

OC pesticides / some PCBsOC pesticides / some PCBs

Association between POPs and 5 components of metabolic syndrome among non-diabetics

WaistWaistcircumferencecircumference

HighHighbloodblood

pressurepressure HighHighfastingfastingglucoseglucose

ElevatedElevatedtriglyceridetriglyceride

LowLowHDL-cholesterolHDL-cholesterol

OC pesticidesOC pesticidesPCBsPCBs

DioxinsDioxinsFuransFurans

Lee DH, et al. Diabetologia (2007)

Diabetes Care 31:1574–1579, 2008

Environmental Research 108: 63– 68, 2008

Diabetologia 51:1416-22, 2008

Diabetologia 53:899-906, 2010

• This association was confirmed in Greenland (Inuit), Taiwan, Japan, Native American, Slovakia and Belgium (Dirink E et al. Obesity, 2010).

• An environment-wide association study (EWAS) on type 2 diabetes mellitus supported (Chirag J et al, PLoS One 2010)

• Confirmed in experimental studies (Lim S, PLoS One, 2009; Ruzzin J et al, Environ Health Persp, 2009)

Association between POPs (causative agent) and metabolic syndrome (disease phenotype) is

established.

Does exposure to POPs cause insulin resistance?

1. National Institute of Nutrition and Seafood Research (NIFES), Norway.2. Department of Biochemistry and Molecular Biology, University of Southern Denmark, Denmark. 3. INSERM U-870, University, INSA Lyon and Hospices Civils, France.4. Others

METHODS: 1. Wistar rats exposed for 28 days to lipophilic POPs (high-fat diet containing crude fish oil obtained from farmed Atlantic salmon). 2. Measured body weight, whole-body insulin sensitivity, POP accumulation, lipid and glucose homeostasis, gene expression and performed microarray analysis.

RESULTS: Rats exposed to crude, but not refined, salmon oil developed insulin resistance, abdominal obesity and hepatosteatosis.

Ruzzin J et al. Environment Health Perspect. Nov. 2009

Endocrine Disruptor, dioxin (TCDD)–Induced Mitochondrial Dysfunction and Apoptosis

in Human Trophoblast-Like JAR CellsSu-Chee Chen et al. Hum Reprod, 2010

• 2.58x increase in lipid peroxides (2 nM TCDD, 4 hrs). • DNA damage marker, 8-OH-dG increased with and increase in mtDNA deletions.• Reduction in mtDNA copy number and ATP content• Increased apoptosis, p53 accumulation, Bax over-expression, cytochrome c release, and sequential caspase 3 activation after TCDD exposure.

The Mitochondrion — A Trojan Horse That Kicks Off Inflammation?

Manfredi, AA, Patrizia Rovere-Querini, P NEJM 362;2133, 2010

DAMP denotes damage-associated molecular pattern,PRR pattern-recognition receptor

Mitochondrial damage

Lee HK et al. BBA General Subject Mar 2010. Ruzzin J et al. Environment Health Perspect.

Nov. 2009

cholesterol

POPs or Mitotoxs

DiabetesDiabetes

HypertensionHypertensionObesityObesity

DyslipidemiaDyslipidemiaAtherosclerosisAtherosclerosis

Syndrome X=

Metabolic syndrome

Cause(s)

Concept of metabolic syndrome

Chemical substances that persist in the environment, bio-accumulate through the food

web, and pose a risk of health and the environment.

What should we give to “chemical substances causing

metabolic syndrome”?

Dioxins and POPs are known as endocrine disruptors, but also affect mitochondria

XenobioticsPersistent organic pollutants

Obesogens

Carcinogens

Mitochondrial toxins vs

Metabogens?

Endocrine disruptors

Hypertensiongens

Grun F, Blumberg B. Endocrine disrupters as obesogens. Mol Cell Endocrinol 2009;304:19–29.

Works to be done

• Establishing cause-effect relationship between xenobiotics exposure and MS

• 3 Koch’s postulates

• Etiologic treatment: drug development and clinical trials

To establish cause-effect relationship between POPs and MS

• POPs are very diverse, small, slowly act, dangerous to handle and ---

• Current detecting methods are too expensive• Need cheap and valid method (for diagnosis):

i.e. CALUX (chemically activated luciferase expression) assay

• Best way to eliminate toxins (evidence-based detoxification therapy)

How should we treat patients with metabolic syndrome?

1. Avoid and remove toxins (xenical, colestimide, activated charcoal, herbs?)2. Recover mitochondrion already damaged (stem cell therapy)3. Current treatment methods- need re-evaluation

Blood concentrations of POPs like p,p′-DDE increase with age.

(a) New Zealand report conducted in 1996–97 (N=1834) and the Canary Islands study in 1997–1998 (N=682),(b) East & West Ger III conducted in 1998 (N=2290 for West Germany and N=534 for East Germany),

Porta M et al. Environment International

34 (2008) 546–561

Environment•Westernized

life style•Aging•Drugs

•Mito-toxins

Acknowledgements

• Park KS, Cho YM, Lim S, KimPak Y, Lee W, and many collaborators, Korea

• Wei Y-H, Taiwan

• Nanjo K, Tanaka M. Japan

• Members of Molecular Diabetology in Asia