Urinary mRNA expression of ACE and ACE2 in human type 2 diabetic nephropathy.
OBJECTIVE
The interplay of ACE and type 2 ACE (ACE2) has been recognised as playing an important role in the tissue renin-angiotensin system within the kidney. In the present study, we measured urinary mRNA expression of ACE and ACE2 in patients with type 2 diabetic nephropathy.


METHODS
We studied 50 patients with diabetic nephropathy: 26 were being treated by ACE inhibitor (ACEI) alone (ACEI group), the other 24 by ACEI and angiotensin-receptor blocker (ARB) (ACEI+ARB group). mRNA expression of ACE and ACE2 was measured by real-time quantitative RT-PCR at 0 and 12 weeks. All patients were then followed for 56 weeks.


RESULTS
Proteinuria correlated significantly with urinary ACE (r=0.454, p=0.001) and ACE2 expression (r=0.651, p<0.001). Urinary ACE2 expression correlated with estimated GFR (r= -0.289, p=0.042). In the ACEI group, there was a significant inverse correlation between the rate of GFR decline and urinary ACE2 expression at baseline (r= -0.423, p=0.031) as well as at 12 weeks (r= -0.395, p=0.046). In contrast, there was no significant correlation between the rate of GFR decline and urinary ACE2 expression at baseline or at 12 weeks in the ACEI+ARB group. The rate of GFR decline did not correlate with the baseline urinary ACE expression of either group.


CONCLUSIONS
There was a relationship between urinary mRNA expression of ACE2 and the degree of proteinuria. The physiological implication and possibility of clinical application of quantifying urinary ACE2 expression require further study.
Wang
G
G
Department of Medicine and Therapeutics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, China.
Lai
F M-M
FM
Lai
K-B
KB
Chow
K-M
KM
Kwan
C-H B
CH
Li
K-T P
KT
Szeto
C-C
CC
D000368:Aged; D000085962:Angiotensin-Converting Enzyme 2; D001794:Blood Pressure; D004247:DNA / Q000235:genetics; D003924:Diabetes Mellitus, Type 2 / Q000201:enzymology* / Q000235:genetics; D003928:Diabetic Nephropathies / Q000201:enzymology* / Q000235:genetics; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D007703:Peptidyl-Dipeptidase A / Q000235:genetics* / Q000652:urine*; D012333:RNA, Messenger / Q000652:urine*; D012084:Renin-Angiotensin System / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
D012333:RNA, Messenger; D004247:DNA; D007703:Peptidyl-Dipeptidase A; C000705307:ACE2 protein, human; D000085962:Angiotensin-Converting Enzyme 2