HSPG Expression in non-alcoholic steato hepatitis And type II Diabetes Mellitus.

Type 2 diabetes mellitus (DM2) will be the major burden of disease in the 21st
century. Nonalcoholic steatosis hepatitis (NASH) is one of the most common
causes of chronic liver injury in many countries. NASH is frequently seen in
patients with type 2 diabetes mellitus and is strongly associated with insulin
resistance. NASH is also associated with dyslipidemia, characterized by
increased triglyceride levels with concomitant small dense LDL-cholesterol
which is strongly associated with macrovascular disease. Currently there is no
therapeutic intervention to reduce or cure NASH.
Patients with familial hypobeta lipoproteinaemia (FHBL) are also characterized
by NASH yet were recently characterized NOT to have insulin resistance. Thus,
different genetic factors driving different pathophysiological mechanisms are
likely to be important for the development of NASH.
Recent experimental studies have indicated a role for heparansulphate
proteoglycans (HSPG) in the development of NASH associated dyslipidemia and
insulin resistance. HSPG*s are cell-surface proteoglycans. These proteoglycans
bind a variety of growth factors, chemokines and enzymes and thereby regulating
a variety of biological activities. In cell culture and animal models, insulin
is associated with alterations of jejununal and hepatic proteoglycan
expression, a decreased affinity for triglyceride rich lipoproteins remnants
and increased free fatty acids in the portal vein. In addition, Esko et al.
recently showed that inactivation of the GlcNAc
N-deacetylase/N-sulfotransferase 1 (NDST1, a HSPG synthesizing enzyme) gene in
murine hepatocytes resulted in a 50% reduction in sulfation of liver heparan
sulfate which concurs with accumulation of triglyceride-rich lipoprotein
particles due to a diminished clearance. Recent data by Williams showed that
the glucosamine-6-O-endosulfatase-2 (SULF2, an enzyme that degrades
cell-surface HSPGs by removing 6-O-sulfate groups) is strongly up regulated in
livers of hypertriglyceridemic db/db mice compared to control mice (11-fold
reduction of sulf2 mRNA, p=0.001).
Recently, arrays for analysis of epithelium adhering and feces gutmicrobiota
have been developed (8); moreover, recent papers have suggested an association
between gut/feces gutmicrobiota and NASH
We would therefore like to investigate whether changes in expression of HSPG
synthesizing and degrading enzymes are associated with presence of dyslipidemia
and insulin resistance in NASH.

Primary Objective:
- HSPG expression in liver tissue of patients with type 2 diabetes mellitus
and NASH compared to liver tissue from subjects without type 2 diabetes
mellitus with and without NASH.
Secondary Objectives:
- Correlation between HSPG expression in liver tissue and gut epithelium with
levels of triglyceride rich lipoproteins in peripheral and portal non-fasting
blood ànd feces samples.
- Correlation between HSPG expression in liver tissue and insulin resistance.

This will be a case control study.
Liverbiopsy tissue from 10 subjects with DM2 associated NASH undergoing gastric
bypass surgery will be compared to livertissue from 10 control subjects with
NASH and no insulin resistance (FHBL) or 10 control subjects with or without
NASH but no insulin resistance (Hepatitis C, heamochromatosis or patients
undergoing hemihepatectomy). Livertissue from control subjects was collected
previously and is therefore not included in te current protocol.

Liverbiopsy during gastric bypass surgery.
Venapunction. Bloodvolume will be 37,5 ml in total
Feaces collection

Liver biopsy, jejunal tissue biopsy, feces collection and additional
bloodwithdrawl are not part of regular treatment. During bypass surgery
procedure, part of the proximal jejunum is removed. We will collect a small
specimen of this gut sample, this has no adverse effects.
A liver biopsy will be performed during gastric bypass surgery. This has no
effect on liverfunction. This procedure carries the risk of bleeding. However,
it will be a biopsy a vu, and the surgeon will be able to inspect the liver
directly after the biopsy has been performed. In case of bleeding the surgeon
will be able to directly stop the blood. Furthermore, during hospital
admission, blood pressure will be measured frequently and blood will be drawn
daily to control for bleeding.
Bloodwithdrawl carries the risk of bruising and may result in discomfort. A
total of 37,5 ml of blood will be withdrawn. This has no adverse effects.
Risk associated with this study is minor and since the prevalence of type II
diabetes is expanding largely new insights into the pathophysiology and
identification of potential therapeutic targets in this disease therefore have
high clinical importance.