GENETIC FACTORS IN INFLAMMATORY

BOWEL DISEASE

I. D. Loranskaya

Russian Medical Academy for Postgraduate Education,Moscow

GENETIC FACTORS IN INFLAMMATORY

BOWEL DISEASE

I. D. Loranskaya

Russian Medical Academy for Postgraduate Education,Moscow

The results of epidemiological studies showed that the genesis of IBD is strongly influenced by two groups of factors:

hereditary predisposition

influence of the environment

The results of epidemiological studies showed that the genesis of IBD is strongly influenced by two groups of factors:

hereditary predisposition

influence of the environment

Kirsner J.B.Spencer J.A.

First reports about familial cases in IBD patients

Kirsner J.B.Spencer J.A.

First reports about familial cases in IBD patients

1963 г.1963 г.

THE ROLE OF THE GENETIC FACTORS IN IBD WAS PROVED BY:

THE ROLE OF THE GENETIC FACTORS IN IBD WAS PROVED BY:

Familial cases of CD and UC are observed in 5-30% of patients (more often in 10-20% of cases);

The number of familial cases of the disease is higher in CD than in UC;

First-degree relatives of UC patients have the highest risk of the pathology development (10-20 fold) as compared to the healthy donors of the same age and sex;

Cases of both CD and UC may be observed in one family, more often in cases when the disease started in the early age;

A high frequency of the IBD occurrence among Ashkenazi jews(2-4 times higher);

Cases of IBD in twins are more often if they are monozygotic, the concordance of monozygotic twins is higher in CD;

Association of IBD with a number of genetic syndromes (Turner’s syndrome, glycogen storage disease type IB, Hermansky-Pudlak syndrome) and with hereditary predisposition diseases (primary sclerosing cholangitis, psoriasis, eczema, celiac disease, ankylosing spondylitis).

Hugot J.-P. et al IBD1the locus of CD susceptibility on chromosome 16q

Satsangi J. et al IBD2the locus of IBD susceptibility on chromosome 12q

IBD3locus on chromosome 6p (HLA–system) determines the susceptibility to specific clinical phenotype in UC

IBD4locus on chromosome 14q – assosiation with CD

IBD5locus on chromosome 5q – association with IBD

IBD6locus on chromosome 19q – association with CD

Hugot J.-P. et al IBD1the locus of CD susceptibility on chromosome 16q

Satsangi J. et al IBD2the locus of IBD susceptibility on chromosome 12q

IBD3locus on chromosome 6p (HLA–system) determines the susceptibility to specific clinical phenotype in UC

IBD4locus on chromosome 14q – assosiation with CD

IBD5locus on chromosome 5q – association with IBD

IBD6locus on chromosome 19q – association with CD

1996 г.

In 2001 Hugot J.P. and Ogura Y. proved the association of CD and NOD2 gene on chromosome 16q in locus IBD1.

NOD2 (nucleotide oligomerisation domain) belongs to NOD gene family and plays an important role in the origin of inflammationas a response to bacterial antigenes.

The NOD gene family is mainly expressed in monocytes, macrophages and B-lymphocytes.

NOD2 geneNOD2 gene

activation of nuclear NFκβ factor, which regulates the expression of the majority of the antiinflammatory cytokines and the response to bacterial polysaccharide

activation of nuclear NFκβ factor, which regulates the expression of the majority of the antiinflammatory cytokines and the response to bacterial polysaccharide

an immune response to bacterial antigenean immune response to bacterial antigene

CARD15 – caspase recruitment domain – the group of enzymes participating in the cell apoptosis process

Association between NOD2/CARD15 gene mutations and CD supports the assumption that this disease is a pathological immune response to enteric microorganisms (or specific bacterial pathogen) with genetic determinacy.

It is known that NOD2/CARD15 recognizes muramyldipeptide – the obligatory component of the cell membrane of all the bacteria living on Earth.

Association between NOD2/CARD15 gene mutations and CD supports the assumption that this disease is a pathological immune response to enteric microorganisms (or specific bacterial pathogen) with genetic determinacy.

It is known that NOD2/CARD15 recognizes muramyldipeptide – the obligatory component of the cell membrane of all the bacteria living on Earth.

NOD2/CARD15NOD2/CARD15

NOD2 mutations (Arg 702 Trp, Gly 908 Arg, Leu 1007 insС) determine the susceptibility to CD in specific racial and ethnic groups (no NOD2 mutations are revealed in Japanese, Afro-American populations and the Israeli Arabs);

NOD2 mutations determine the development of CD phenotypes (ileitis, ileitis and right-side colitis, strictures, penetrations);they are present in 20-27% of disease cases.

It is important to prove the role of NOD2 mutations in cases of sporadic CD forms.

NOD2 mutations (Arg 702 Trp, Gly 908 Arg, Leu 1007 insС) determine the susceptibility to CD in specific racial and ethnic groups (no NOD2 mutations are revealed in Japanese, Afro-American populations and the Israeli Arabs);

NOD2 mutations determine the development of CD phenotypes (ileitis, ileitis and right-side colitis, strictures, penetrations);they are present in 20-27% of disease cases.

It is important to prove the role of NOD2 mutations in cases of sporadic CD forms.

HOWEVER THERE IS A LOT OF WHITE SPOTS IN THE STUDY OF THE GENE NOD2 ROLE IN IBD:

HOWEVER THERE IS A LOT OF WHITE SPOTS IN THE STUDY OF THE GENE NOD2 ROLE IN IBD:

THE ROLE OF NOD2/CARD15 MUTATIONS FOR THE SUSCEPTIBILITY TO CD IN RUSSIA

THE ROLE OF NOD2/CARD15 MUTATIONS FOR THE SUSCEPTIBILITY TO CD IN RUSSIA

69 CD patients54 healthy donors DNA SCREENING FOR MUTATIONS :

P 268 SR 702 WG 908 Rins 3020 C

69 CD patients54 healthy donors DNA SCREENING FOR MUTATIONS :

P 268 SR 702 WG 908 Rins 3020 C

39 (57%) patients1 mutation

14(20,3%) - 2 mutations

10(14,5%) – 3 mutations

6 (8,7%) – 4 mutations

1 – 5 mutant alleles

DONORS:

22(41%) – 1 mutation

7(13%) – 2 mutations

ALLELE FREQUENCYALLELE FREQUENCY

mutations in R 702 W, G 908 R, ins 3020 C high risk of CD development in Russiamutations in R 702 W, G 908 R, ins 3020 C high risk of CD development in Russia

0,490,44

0,26

0,020,05

0

0,57

0,08

0

0,1

0,2

0,3

0,4

0,5

0,6

P 268 S R 702 W G 908 R ins 3020 C

CD Donors

(Loranskaya I.D., Polyakov A.V., Stepanova E.V., 2006)(Loranskaya I.D., Polyakov A.V., Stepanova E.V., 2006)

HLA SYSTEM (IBD3)HLA SYSTEM (IBD3)

An important role in the human immune homeostasis, carries out the genetic control over immune reactions,

Polymorphism of this system (more than 1000 alleles) provides a high degree of an individuality in human being and different ethnic populations

The HLA-DNA genotyping in the PCR makes it possible to study the genetic markers of IBD

DRB1*0103 gene is accosiated with UC and CD with colon lesion (Watts D.A., Satsangi J., 2002)

An important role in the human immune homeostasis, carries out the genetic control over immune reactions,

Polymorphism of this system (more than 1000 alleles) provides a high degree of an individuality in human being and different ethnic populations

The HLA-DNA genotyping in the PCR makes it possible to study the genetic markers of IBD

DRB1*0103 gene is accosiated with UC and CD with colon lesion (Watts D.A., Satsangi J., 2002)

THE STUDY OF HLA ANTIGENES AND GENES IN IBD PATIENTS IN RUSSIA

THE STUDY OF HLA ANTIGENES AND GENES IN IBD PATIENTS IN RUSSIA

Positive Negativeassociations associations

Ulcerative colitis

N.A.Morozova,1997 В 14 Сw4, DR 3, DR 5 Aw 19, DR 4A.M.Pershko,1998 DR 3, B 35I.I.Khidiyatov,1999 (Bashkiriya) DRB 1 * 13 DRB 1 * 04

Crohn’s diseaseА 3, В 14 Aw 19

– marker of predisposition

UC (RR=1,8)CD (RR=4,1)

– marker of predisposition

UC (RR=1,8)CD (RR=4,1)

DRB1 * 01

THE ASSOCIATION ANALYSIS OF LOCUS DRB1 ALLELES IN UC WITH DIFFERENT CLINICAL FORMS OF THE DISEASE

THE ASSOCIATION ANALYSIS OF LOCUS DRB1 ALLELES IN UC WITH DIFFERENT CLINICAL FORMS OF THE DISEASE

LOCALIZATION

Left-side lesion Distal forms

HLA-genes DRB1*04 DRB1*08

Patients 0,0 12,1

Controls 12,2 3,7

RR 0,12 3,5

1/RR 8,3 -

ONSET OF THE DISEASE

up to 30 years 30-50 years 51-70 years

HLA-genes DRB1*01 DRB1*04 DRB1*08 (DRB1*11) (DRB1*15)

Patients 17,5 1,8 10,7 14,3 20,0

Controls 8,2 12,2 3,7 2,7 0,7

RR 2,4 0,13 3,1 6,0 36,5

1/RR 7,7

THE ASSOCIATION ANALYSIS OF LOCUS DRB1 ALLELES IN UC WITH DIFFERENT CLINICAL FORMS OF THE DISEASE

THE ASSOCIATION ANALYSIS OF LOCUS DRB1 ALLELES IN UC WITH DIFFERENT CLINICAL FORMS OF THE DISEASE

TYPE OF THE DISEASE

Chronic continuous Chronic recurring

HLA-genes DRB1*01 DRB1*11 DRB1*04

Patients 18,4 2,6 1,5

Controls 8,2 13,9 12,2

RR 2,5 0,17 0,11

1/RR 5,9 9,1

THE ASSOCIATION ANALYSIS OF LOCUS DRB1 ALLELES IN UC WITH DIFFERENT CLINICAL FORMS OF THE DISEASE

THE ASSOCIATION ANALYSIS OF LOCUS DRB1 ALLELES IN UC WITH DIFFERENT CLINICAL FORMS OF THE DISEASE

THE INTESTINAL BARRIER DEFECT IS GENETICALLY DETERMINED FOR CD AND

IS OBSERVED IN A LOT OF PATIENTS’FIRST-DEGREE RELATIVES

(THE CD GENETIC MARKER)

THE INTESTINAL BARRIER DEFECT IS GENETICALLY DETERMINED FOR CD AND

IS OBSERVED IN A LOT OF PATIENTS’FIRST-DEGREE RELATIVES

(THE CD GENETIC MARKER)

PERMEABILITY OF THE INTESTINAL BARRIER FOR OVA IN CD AND UC

PERMEABILITY OF THE INTESTINAL BARRIER FOR OVA IN CD AND UC

0102030405060708090

100

CD UC

91%

67%

OVA

, ng/

ml

OVA

, ng/

ml

Nor

mal

(0

-4) n

g/m

lN

orm

al

(0-4

) ng/

ml

OVA IN UC PATIENTSOVA IN UC PATIENTSO

VA, n

g/m

lO

VA, n

g/m

l

17,738,7

156,8

0

20

40

60

80

100

120

140

160

mild medium severe

17,738,7

156,8

0

20

40

60

80

100

120

140

160

mild medium severe

Ulcerative Colitis FormsUlcerative Colitis Forms

Р=0,04

PERMEABILITY OF THE INTESTINAL BARRIER FOR OVA IN UC (AS PER FOOD INTOLERANCE)PERMEABILITY OF THE INTESTINAL BARRIER FOR OVA IN UC (AS PER FOOD INTOLERANCE)

0102030405060708090

present not present

OVA

, ng/

ml

OVA

, ng/

ml

food intolerancefood intolerance

Р=0,039

OVA ABSORBABILITY IN UCOVA ABSORBABILITY IN UC

0

20

40

60

80

100

120

disbacteriosis + disbacteriosis -

OVA

, ng/

ml

OVA

, ng/

ml

Р=0,031

GENE-CANDIDATES OF PREDISPOSITION TO IBDGENE-CANDIDATES OF PREDISPOSITION TO IBD

3 CHROMOSOMERegion III Gene TNF-αHLA system predisposition to CD and severe UC forms

Region I Genes MICA и MICBHLA system gene family encoding the expression of stress

glycoproteins in epithelium

Protein gene GNA12

Gene MLH1Association with colon cancer

Region III Gene TNF-αHLA system predisposition to CD and severe UC forms

Region I Genes MICA и MICBHLA system gene family encoding the expression of stress

glycoproteins in epithelium

Protein gene GNA12

Gene MLH1Association with colon cancer

GENE FAMILY IL 1 – (IL-1α, IL-1β, IL-1RA)GENE FAMILY IL 1 – (IL-1α, IL-1β, IL-1RA)

2 CHROMOSOME

MUC-3 – encodes mucosa secretionMDR-1 (multidrug resistance gene) – membranetransporting protein

MUC-3 – encodes mucosa secretionMDR-1 (multidrug resistance gene) – membranetransporting protein

ICAM-1 gene (intercellular adhesiоn molecule) – determines the neutrophils’ migration to the inflammatory areaICAM-1 gene (intercellular adhesiоn molecule) – determines the neutrophils’ migration to the inflammatory area

7 CHROMOSOME

19 CHROMOSOME

ОСТN (cation transporter genes) – determine the epithelial barrier functionОСТN (cation transporter genes) – determine the epithelial barrier function

5 CHROMOSOME

DLG 5 (Drosophila discs large homologue 5)

10 CHROMOSOME

GENE-CANDIDATES OF PREDISPOSITION TO IBDGENE-CANDIDATES OF PREDISPOSITION TO IBD

ULCERATIVE COLITIS IS A DISEASE CHARACTERIZED BY A HIGH RISK OF COLON CANCER DEVELOPMENT

ULCERATIVE COLITIS IS A DISEASE CHARACTERIZED BY A HIGH RISK OF COLON CANCER DEVELOPMENT

Changes in the cells’ genetics – chromosome aberrations, chromatic change, chromosomal instability precede dysplasia and neoplasia

A high expression of REG 1α protein (regeneration gene) is observed in colon mucosa of UC patients which evidently plays an important role in the development of colorectal cancer. The DNA damage in the form of microsattelite instability (MSI) is accompanied by higher levels of DNA reparation enzymes activity – AAG and APE1, in the area of inflammation, which also increases the risk of the development of neoplasia

COMPUTER MICROSPECTROPHOTOMETRY OF COLON TISSUE SAMPLINGS IN US PATIENTSCOMPUTER MICROSPECTROPHOTOMETRY OF COLON TISSUE SAMPLINGS IN US PATIENTS

caecum transverse colon sigmoid

DNA 4,6 + 0,9 с 3,5 + 0,75 с 3,3 + 0,3 с

PA 2,6 + 0,5 1,5 + 0.4 1,3 + 0,15

caecum transverse colon sigmoid

DNA 4,6 + 0,9 с 3,5 + 0,75 с 3,3 + 0,3 с

PA 2,6 + 0,5 1,5 + 0.4 1,3 + 0,15

DNA-INDEX

severe dysplasia 5,2 с

benign tumors and transition conditionswith dysplasia features 3,6 с

DNA-INDEX

severe dysplasia 5,2 с

benign tumors and transition conditionswith dysplasia features 3,6 с

THANKS FOR ATTENTION !THANKS FOR ATTENTION !