Alterations in gastric mucin synthesis by Helicobacter pylori

Table 1 Human mucin genes

Gene	Locus	mRNA size	Tandem Repeats	Other structural features	Expression in normal tissues
MUC1	1q21-24	4-7 kb	20 AA	Transmembrane	Most epithelia
MUC2	11p15.5	14-16 kb	23 AA, -16 AA	D-domains, cystine knot	Colon > small intestine > respiratory tract
MUC3	7q22	16-17.5 kb	17 AA, 59 AA	Cystine knot	Small intestine > colon, gall bladder
MUC4	3q29	16.5-24 kb	16 AA		Respiratory tract, cervix > GI tract
MUC5AC	11p15.5	17-18 kb	8 AA	D-domains, cystine knot	Stomach (surface) > respiratory tract
MUC5B	11p15.5	17.5 kb	29 AA, interrupted	D-domains, cystine knot	Respiratory tract, salivary gland, cervix > GI tract
MUC6	11p15.5	16.5-18 kb	169 AA	Cystine knot	Stomach (glands), gall bladder
MUC7	4	2.4 kb	23 AA	No homology to large mucins	Salivary glands
MUC8	12q24.3	-9 kb	18 AA, 41 AA	Not Thr/Ser rich	Trachea

Table 2 Histochemical staining of mucins in gastric biopsy specimens

Antigen		H.pylori negative	H.pylori positive
MUC5AC	% Stained*a, intensity score (surface)	(69.8% ± 3.5%), 2.8 ± 0.1	(51.2% ± 5.7%), 2.6 ± 0.1
MUC6	% Stained**a, intensity score (surface)a	4%, 0.1 ± 0.1	72%, 1.8 ± 0.2
Le\ + b	% Stained**a, intensity score (surface)a	63%, 0.9 ± 0.2	96%, 1.9 ± 0.2
Paradoxical ConA	% Stained**a, intensity score (surface)a	18%, 0.4 ± 0.2	79%, 2.1 ± 0.3
LeX	% Stained**a, intensity score (surface)a	4%, 0.4 ± 0.4	59%, 1.0 ± 0.2
MUC1	Intensity score (surface), intensity score(glands)	2.6 ± 0.2, 1.7 ± 0.1	2.7 ± 0.1, 1.4 ± 0.2
Sialyl Tn	Intensity score (surface), intensity score (glands)a	1.8 ± 0.2, 1.9 ± 0.1	1.6 ± 0.1, 1.4 ± 0.1

^*% of surface epithelium stained; ^**% of patients with surface staining;

^aP < 0.05, H.pylori positive vs H.pylori negative