Original Article

Yonago Acta medica 2015;58:63–68

Influence of Olmesartan on Sirtuin 1 mRNA Expression in 5/6 		
Nephrectomized Spontaneously Hypertensive Rats
Tomoaki Takata, Chishio Munemura, Takeaki Fukui, Satoko Fukuda and Yoshikazu Murawaki

Division of Medicine and Clinical Science, Department of Multidisciplinary Internal Medicine, School of Medicine, Tottori University
Faculty of Medicine, Yonago 683-8504, Japan

ABSTRACT

Conclusion Expression of SIRT1 is decreased in
5/6Nx SHRs compared to Wistar rats. Olmesartan suppressed glomerular sclerosis, but did not increase theexpression of SIRT1, suggesting that the renoprotective
effect of olmesartan is independent of the SIRT1 pathway.

Background

Recent studies revealed that sirtuin 1(SIRT1) has a relation to the mechanism of transforming growth factor-beta (TGF-beta) mediated apoptosis inglomerular mesangial cells and plays an important rolein blood pressure regulation. It has been suggested that
SIRT1 contributes to the renoprotective effect of angiotensin receptor blocker (ARB), but this has not yet become clearly recognized. In this study, we examined therelationship between SIRT1 and the therapeutic effect ofolmesartan on renal injury in nephrectomized spontaneously hypertensive rats (SHRs).
Methods Male Wistar rats and 5/6 nephrectomized(5/6Nx) SHRs were assigned to 5 groups as follows:group A, Wistar rats; group B, Wistar rats administeredhigh-dose olmesartan (15 mg/kg/day); group C, 5/6Nx
SHRs; group D, 5/6Nx SHRs administered low-dose(3 mg/kg/day) olmesartan; and group E, 5/6Nx SHRs
administered high-dose olmesartan. The drugs wereadministered for 12 weeks. Blood pressure and urinary
protein excretion were measured every 4 weeks. Serum
creatinine, glomerular sclerosis, SIRT1 mRNA level,
TGF-beta mRNA level and klotho mRNA level were
measured at the end of the examination.
Results
Systolic blood pressure, urinary protein excretion, serum creatinine and glomerular sclerosis in
Wistar rats were significantly lower than that of 5/6Nx
SHRs. Among 5/6Nx SHRs, high doses of olmesartan
significantly decreased urinary protein excretion, serum
creatinine and glomerular sclerosis compared to the
non-treated and low-dose olmesartan groups. Expressionof SIRT1 and klotho mRNA were significantly downregulated in 5/6Nx SHRs; however, olmesartan did not
attribute to any change in gene expression. Expression of
TGF-beta mRNA was significantly increased in 5/6Nx
SHRs, and olmesartan did not affect the level of TGFbeta mRNA expression.

Key words angiotensin receptor antagonists; chronic
renal failure; sirtuin; spontaneously hypertensive rat

Recent studies revealed that caloric restriction increases
the life span of rats and positively affects various diseases such as diabetes, atherosclerosis, neurodegenerative
diseases, cancer and age-associated renal injury.1 The
relationship between such favorable effects and caloric
restriction was found from the observation of budding
yeast. Guarente and colleagues2 discovered that Sir2
(silent information regulator 2), the first sirtuin family
member, increases life span. In mammals, seven homologues of Sir2 [sirtuin 1 (SIRT1) to sirtuin 7] have been
detected. SIRT1 is mainly expressed in organs such as
the kidney, liver and brain, and adipose tissue. Expression of SIRT1 increases with caloric restriction, whereas
it decreases with senescence. SIRT1 inhibits transforming growth factor-beta (TGF-beta)-induced apoptosis inglomerular mesangial cells.3
There are convincing data that the renin-angiotensin
system is a major mediator of renal injuries. Blood pressure control using angiotensin receptor blocker (ARB)
can reduce the progression of nephropathy.4 Several
studies report that SIRT1 plays an important role inblood pressure regulation.5–8 It is considered that SIRT1
contributes to the renoprotective effect of renin-angiotensin system blockade.1
Angiotensin II participates in various renal lesions
and ARB has a kidney protective effect. It is reported
that telmisartan, an angiotensin II type 1 receptor blocker, increases the expression of SIRT1 mRNA.9 SIRT1
also may contribute to kidney protection by ARB, but
this has not yet been clearly proven.
In this study, we examined the correlation between
SIRT1 and the therapeutic effect of olmesartan, another
ARB on renal injury in nephrectomized spontaneously
hypertensive rats (SHRs).

Corresponding author: Chishio Munemura, MD, PhD
chishiom@med.tottori-u.ac.jp
Received 2015 February 2
Accepted 2015 February 6
Abbreviations: 5/6Nx, 5/6 nephrectomized; ARB, angiotensin
receptor blocker; IGS, index of glomerular sclerosis; PPAR, peroxisome proliferator-activated receptor; SHR, spontaneously hypertensive rat; Sir2, silent information regulator 2; SIRT1, sirtuin 1;
TGF-beta, transforming growth factor-beta

63

T. Takata et al.
Table 1. Primer sequences
TGF-beta
Sirtuin 1
KlothoBeta-actin

Forward primer

Reverse primer

5'-CCTGCCCCTACATTTGGA-3'5'-CAGTGAGAAAATGCTGGCCTA-3'5'-CAAGAAGTTCATAATGGAAAGCTTAAA-3'5'-CTGGCTCCTAGCACCATGA-3'5'-TGGTTGTAGAGGGCAAGGAC-3'5'-TTGGTGGTACAAACAGGTATTGA-3'5'-ATGCGGTGTACCCAATGAC-3'5'-TAGAGCCACCAATCCACACA-3'

TGF-beta, transforming growth factor-beta.

RNA extraction and reverse transcription PCR
analysis

MATERIALS AND METHODS
Animals

Tissue samples were homogenized and total RNA wasextracted using an RNasey Mini Kit (Qiagen, Hilden,
Germany). RNA concentration was determined by measuring absorbance at 260 nm and the RNA quality wasverified by electrophoresis on an ethidium-bromidestained 1% agarose gel. About 2 μg of total RNA wasreverse transcribed in a final volume of 10 μL containing
4 μL of 5 × standard buffer, 2 μL of 0.1 M dTT, 1 μL
of M-MLV reverse transcriptase (Invitrogen, Carlsbad,CA), 1 μL of 0.5 μg/μL Random Primer (Promega, Madison, WI), 1 μL of 20 mM dNTPs and 1 μL of RNase Inhibitor (Wako Pure Chemical Industries, Osaka, Japan).
Samples were incubated at 37 ˚C for 60 min, followed by
95 ˚C for 5 min and cooling to 4 ˚C for 5 min.

Male SHRs of the Izumo strain were obtained fromJapan SLC (Shizuoka, Japan). As controls, male Wistar
rats were obtained from Japan SLC. All rats were maintained in a room at a controlled temperature of 24 ± 2 ˚Cwith a 12-h light-dark cycle. Animals were given standard pellet chow and tap water. All experimental procedures were carried out in accordance with the Animal
Experimentation Guidelines of Tottori University.
Establishment of model

Male 6-week-old SHRs underwent 5/6-nephrectomy. A
surgical excision of approximately 2/3 of the renal cortex of the left kidney was performed. One week later, theright kidney was removed. One week after the surgery
baseline measurements of body weight, blood pressure,urine volume and urinary protein were performed. Bloodpressure was measured in the conscious state using thetail-cuff method with a sphygmomanometer (Softron,
Tokyo, Japan). Urine was collected from individual rats
housed in metabolic cages for 24 h. Olmesartan as ARB
was administered orally once a day using a gastric tube.
Rats were divided into 5 experimental groups: group A,
Wistar rats (n = 8); group B, Wistar rats administeredhigh-dose olmesartan (15 mg/kg/day, n = 8); group C,
SHRs (n = 8); group D, SHRs administered low-dose
olmesartan (3 mg/kg/day, n = 8) and group E, SHRs administered high-dose olmesartan (15 mg/kg/day, n = 8).
Dosages of olmesartan were selected based on previous
reports.10, 11 The drug was administered once a day for
12 weeks. Measurements of body weight, blood pressure, urine volume and urinary protein was performed
every 4 weeks in each group.
After 12 weeks of drug administration, rats weresacrificed under pentobarbital anesthesia. Blood samples
were obtained prior to death. Serum samples werefrozen and stored at –80 ˚C, and serum creatinine wasmeasured. Remnant kidneys were removed, and a partof each kidney sample was fixed in 10% buffered formalin and embedded in paraffin for histological analysis.

Real-time PCR

For quantitative real-time PCR, we used 10 μL of reverse transcribed samples: EXPRESS qPCR Super mix
Premixed ROX (Invitrogen), 5 μL; forward primer (10μM), 0.9 μL; reverse primer (10 μM), 0.9 μL; a TaqMan
Probe (2 μM), 1.2 μL (Roche) and a cDNA sample, 2
μL. mRNA levels of TGF-beta, SIRT1 and klotho wereassessed by real-time PCR assays using beta-actin asa housekeeping gene. The forward and reverse primer
sequences used for this study are shown in Table 1. The
thermal cycler conditions were as follows: hold at 95 ˚Cfor 30 s and 60 ˚C for 1 min.
Histological analysis

Three-micrometer sections of formalin-fixed, paraffinembedded kidney samples were stained with periodic
acid-Schiff and periodic acid-methenamine silver. To
calculate focal glomerular sclerosis, 100 to 150 glomeruli from each stained specimen were examined. The
degree of sclerosis in each glomerulus was subjectively
graded on a scale of 0 to 4 as follows: Grade 0, nochange; Grade 1, sclerotic area less than or equal to 1/4of the glomerulus or the presence of distinct adhesion
between the capillary tuft and Bowman’s capsule; Grade2, sclerosis of 1/4 to 1/2 of the total glomerular area;
Grade 3, sclerosis of 1/2 to 3/4 of the total glomerular64

5/6Nx SHR
5/6Nx SHR + Low OLM
5/6Nx SHR + High OLM
Wistar
Wistar + High OLM

Systolic blood pressure(mmHg)
250
200
150
100
50
0

0

4

8

A

***

Urinary protein excretion

Olmesartan on SIRT1 expression in renal damage

***
***

(g/day)
40
35
30
25
20
15
10
5
0

12 (week)***

After operation

Fig. 1. Systolic blood pressure during the experimental period.
The systolic blood pressure is higher in SHRs than in Wistar rats.
At week 12, olmesartan significantly decreased the systolic bloodpressure dose dependently (P < 0.01). Low OLM, olmesartan 3
mg/kg/day; High OLM, olmesartan 15 mg/kg/day; 5/6Nx SHR,
5/6 nephrectomized spontaneously hypertensive rat.

B

***
***

IGS = (1 × N1) + (2 × N2) + (3 × N3) + (4 × N4)(N0 + N1 + N2 + N3 + N4)

**

***

**
***
**
***
***

3.0
2.5
2.0
1.5
1.0
0.5
0.0

W
is
ta
r

area; and Grade 4, sclerosis of more than 3/4 of theglomerulus. The index of glomerular sclerosis (IGS) was
calculated by using the following formula as previously
reported10:

**

Hi Wi
gh st
O ar +
LM
5/
6N
x
SH
R
5/
6N
x
Lo S
w HR
O +
LM
5/
6N
Hi x S
gh H
O R+
LM

Serum creatinine(mg/dL)******

Fig. 2. Urinary protein excretion and serum creatinine.
A: Urinary protein excretions are lower in the Wistar rats thanin the SHRs. Among SHRs, the high-dose olmesartan groupshow lower urinary protein excretion.
B: The serum creatinine levels are significantly higher in the
SHRs than in the Wistar rats. Among SHRs, the high-dose
olmesartan group show lower serum creatinine, while there
is no difference between the low-dose group and non-treatedgroup.
**P < 0.01, *** P < 0.001. Abbreviations, refer to the legends ofFig. 1.

where N is the number of glomeruli at each grade ofsclerosis.
Statistical analysis

Statistical significance of intergroup differences in quantitative data was assessed by Student’s t-test (StatFlex
version 6 for Windows, Artec, Osaka, Japan). P < 0.05
was considered significant.
RESULTS
Blood pressure

Proteinuria

The systolic and diastolic blood pressure in the rats during the 12-week experimental period is shown in Fig. 1.
The systolic blood pressure was higher in 5/6Nx SHRs
than in Wistar rats during the 12-week experimental
period. The systolic pressure increased throughout theexperimental period in the nephrectomized group (group
C). At week 12, olmesartan decreased systolic bloodpressure dose dependently (groups D and E) (P < 0.01).
However, there was no significant difference in systolicblood pressure between the high-dose olmesartan group(group E) and low-dose group (group D) at week 4 andweek 8. There was a similar trend for diastolic pressure(data not shown).

Figure 2A shows total urinary protein excretion in eachgroup at the end of the examination. Urinary protein levels were lower in the Wistar rats (groups A and B) than
SHRs (groups C, D and E). Among SHRs, those treatedwith high-dose olmesartan (group E) showed lower urinary protein excretion.
Serum creatinine

Figure 2B shows serum creatinine in each group at week
12. The serum creatinine levels were significantly higher
in SHRs than Wistar rats. Among SHRs, those treatedwith high-dose olmesartan (group E) showed lower se65

T. Takata et al.

Arum creatinine, while there was no difference between
those treated with low-dose olmesartan (group D) andnon-treated rats (group C).

Grade 0

Histological findings in the kidney
Figure 3 shows the IGS in each group. In the Wistar rats
(groups A and B), only a few sclerotic changes of glomeruli and interstitial fibrosis were observed. The value ofthe index treated with high-dose olmesartan group (groupE) was significantly lower than that of low-dose olmesartan group (group D) and non-treated group (group C),
respectively.

No change

Grade 1
Sclerosis ofmRNA quantification of TGF-beta, SIRT1 andklotholess than or equal
to 1/4 of the glom-

The SIRT1 mRNA level in the nephrectomized rats
was significantly decreased when compared with thatin the Wistar rats. Administration of olmesartan did notchange in the level of SIRT1 expression among SHRs
(Fig. 4A). The level of TGF-beta mRNA expression in
the non-treated SHRs (group C) was significantly higher
than the Wistar rats (groups A and B). Olmesartan did
not affect the level of TGF-beta mRNA expression
among each group (Fig. 4B). The klotho mRNA levelin the nephrectomized rats was significantly lower thanthat in the Wistar rats, and olmesartan did not affect thelevel of klotho mRNA expression (Fig. 4C).

erulus or the presence of distinct
adhesion between
the capillary tuft
and Bowman’s
capsuleGrade 2
Sclerosis of
1/4–1/2 of the total
glomerular area

Sclerosis of
1/2–3/4 of the total
glomerular area

***
2.5

***

***

***
***

***

***

2.0
1.5
1.0
0.5
0.0

Hi Wi
gh sta
O r+
LM
5/
6N
x
SH
R
5/
6N
Lo x S
w HR
O +
LM
5/
6N
Hi x S
gh H
O R+
LM

Grade 3

***

W
is
ta
r

Index of glomerular sclerosis

B

Fig. 3. Index of glomerular sclerosis (IGS).
A: Classification of glomerular sclerosis by periodic acid-Schiffstain. Bar = 200 µm.
B: The values of the index in the high-dose olmesartan groups
are significantly lower than those in the low-dose groups andnon-treated groups. ***P < 0.001. Abbreviations, refer to thelegends of Fig. 1.

Grade 4
Sclerosis of
more than 3/4 ofthe glomerulus

IGS = (1 × N1) + (2 × N2) + (3 × N3) + (4 × N4)(N0 + N1 + N2 + N3 + N4)
N, the number of glomeruli at each grade of sclerosis.

66Olmesartan on SIRT1 expression in renal damage*

SIRT1/beta-actin

A

*

**

0.016
0.014
0.012
0.010
0.008
0.006
0.004
0.002
0.000

*
**

0.20

***

*

*

***

0.15
0.10
0.05
0.00

***
***
***

C

***
***

0.20

***

0.15
0.10
0.05
0.00

W
is
ta
r

Klotho/beta-actin

**

**

Hi Wi
gh sta
O r+
LM
5/
6N
x
SH
R
5/
6N
Lo x S
w HR
O +
LM
5/
6N
Hi x S
gh H
O R+
LM

TGF-beta/beta-actin

B**

DISCUSSION
In the present study, olmesartan decreased proteinuria
and ameliorate histological renal damage in SHRs.
SIRT1 expression in the kidney decreased in SHRs compared to normotensive Wistar rats, and olmesartan did
not increase SIRT1 expression in the kidneys of SHRs.
SHRs have been used as a model for essential hypertension in humans, and 5/6Nx rats have commonly
been used as an experimental models for chronic renal
failure in humans.10 In the present study, we combined
these two models, and prepared 5/6Nx SHRs. During
the 12-week experimental period, blood pressure, urinary protein and glomerular sclerosis in the 5/6Nx SHRs
increased progressively. After 12 weeks, the glomerularsclerosis was remarkable.
Expression of SIRT1 increases with caloric restriction and in conditions that cause oxidative stress and
DNA damage,12, 13 while it decreases with a high fat diet,insulin resistance, high glucose and senescence.1 In thekidney, SIRT1 acts as a renal survival factor by conferring resistance to cellular stress such as hypoxia, reducing interstitial fibrosis, inhibiting tubular and glomerularcell apoptosis and inflammation and regulating sodium
handling, blood pressure and renal lipid metabolism.5 In
the present study, the expression of SIRT1 in the kidney
was decreased in SHRs compared to Wistar rats. In aprevious study, however, the expression of SIRT1 wasincreased in the heart of SHRs.14
The renin-angiotensin system plays an importantrole in the development of renal injury. There are convincing data that the renin-angiotensin system is a major
mediator of renal injuries. Angiotensin II induces thegeneration of cytotoxic products such as superoxideand hydrogen peroxide via angiotensin type 1 receptor
stimulation. Olmesartan and other ARBs reduce oxidative stress.15, 16 In addition to the effect on glomerular
hypertension, ARBs are effective in reducing interstitial
fibrosis and tubular atrophy, each of which is closely
correlated to progressive renal dysfunction. In the present study, olmesartan showed an effect in decreasing
blood pressure and preventing glomerular sclerosis. Fanet al. reported that ultrahigh doses of olmesartan showed
greater renoprotective effects, and that efficacy was independent of blood pressure.11
Miyazaki reported that overexpression of SIRT1 in
vascular smooth muscle cells or treatment with resveratrol, an activator of SITR1, suppressed angiotensin type
1 receptor expression.6 In the present study, however,olmesartan did not show any effect on the expression of
SIRT1 in both SHRs and Wistar rats. Shiota et al. reported that telmisartan, an angiotensin II type 1 receptor
blocker, increased the expression of SITR1 in the skel-

Fig. 4. Levels of mRNA for sirtuin 1 (SIRT1), transforming
growth factor (TGF)-beta and klotho gene expression in renal tissue. The levels were standardized using the beta-actin level.
A: SIRT1 mRNA levels in the SHRs are significantly decreased
than in the Wistar rats. Among SHRs, olmesartan does not
attribute to any change in the level of SIRT1 mRNA expression.
B: Levels of TGF-beta mRNA expression in the SHRs are
significantly higher than in the Wistar rats. Among SHRs,
olmesartan does not affect the level of TGF-beta mRNA expression.
C: Levels of klotho mRNA expression in the SHRs are significantly lower than in the Wistar rats. Among SHRs, olmesartan does not affect the level of klotho mRNA expression.
*P < 0.05, **P < 0.01, ***P < 0.001. Abbreviations, refer to thelegends of Fig. 1.

67

T. Takata et al.

etal muscle of obese smice.9 Telmisartan acts as a peroxisome proliferator-activated receptor (PPAR)-gamma
activator.17 Elena suggested that PPARs participate in
the retardation of aging mediated by angiotensin II inhibition.18 Imayama showed that telmisartan suppressedangiotensin II type 1 receptor expression through the
PPAR-gamma mediated pathway.19 It is supposed thatthe renoprotective effect of olmesartan is related toblood pressure regulation and oxidative stress, and that
this effect is independent of SIRT1 pathway.
Klotho is known as a circulating hormone that represses the intracellular signals of insulin and insulinlike growth factor 1 and acts as an aging-suppressor.18
Downregulation of the klotho gene in the kidney has
been reported in SHRs, and in an experimental study,olmesartan prevented klotho downregulation resulting ina renoprotective effect.20 In the present study, however,olmesartan did not show any effect on klotho mRNA
expression in SHR groups.
In conclusion, olmesartan suppressed glomerularsclerosis, but did not increase the expression of SIRT1,
suggesting that the renoprotective effect of olmesartan isindependent of the SIRT1 pathway. Further studies are
required to investigate the correlation between angiotensin and sirtuins.

8 Mattagajasingh I, Kim CS, Naqvi A, Yamamori T, Hoffman
TA, Jung SB, et al. SIRT1 promotes endothelium-dependent
vascular relaxation by activating endothelial nitric oxide
synthase. Proc Natl Acad Sci USA. 2007;104:14855-60.
PMID: 17785417.
9 Shiota A, Shimabukuro M, Fukuda D, Soeki T, Sato H,
Uematsu E, et al. Telmisartan ameliorates insulin sensitivity
by activating the AMPK/SIRT1 pathway in skeletal muscle ofobese db/db mice. Cardiovasc Diabetol. 2012;11:139. PMID:
23137106.
10 Kanazawa M, Kohzuki M, Yoshida K, Kurosawa H, Minami
N, Saito T, et al. Combination therapy with an angiotensinconverting enzyme (ACE) inhibitor and a calcium antagonist:beyond the renoprotective effects of ACE inhibitor monotherapy in a spontaneous hypertensive rat with renal ablation.
Hypertens Res. 2002;25:447-53. PMID: 12135325.
11 Fan YY, Baba R, Nagai Y, Miyatake A, Hosomi N, Kimura
S, et al. Augmentation of intrarenal angiotensin II levels in
uninephrectomized aldosterone/salt-treated hypertensive rats;
renoprotective effects of an ultrahigh dose of olmesartan. Hypertens Res. 2006;29:169-78. PMID: 16755152.
12 Cohen HY, Miller C, Bitterman KJ, Wall NR, Hekking B,
Kessler B, et al. Calorie restriction promotes mammaliancell survival by inducing the SIRT1 deacetylase. Science.
2004;305:390-2. PMID: 15205477.
13 Rodgers JT, Lerin C, Haas W, Gygi SP, Spiegelman BM,
Puigserver P. Ntrient control of glucose homeostasis through acomplex of PGC-1alpha and SIRT1. Nature. 2005;434:113-8.
PMID: 15744310.
14 Li L, Zhao L, Yi-Ming W, Yu YS, Xia CY, Duan JL, et al.
Sirt1 hyperexpression in SHR heart related to left ventricular
hypertrophy. Can J Physiol Pharmacol. 2009;87:56-62. PMID:
19142216.
15 Jo F, Morimoto S, Nakahigashi M, Kusabe M, Someya K,
Morita T, et al. Olmesartan induces renoprotective effects bystimulating angiotensin type 2 receptors and reducing oxidative stress in diabetic nephropathy. Kidney Blood Press Res.
2011;34:418-23. PMID: 21709422
16 A r oz a l W, Wa t a n a b e K , Ve e r ave e d u P T, M a M ,Thandavarayan RA, Suzuki K, et al. Effects of angiotensin receptor blocker on oxidative stress and cardiorenal function in streptozotocin-induced diabetic rats.
Biol Pha r m Bull. 2009;32:1411-6. PM I D: 19652382.
17 Clasen R, Schupp M, Foryst-Ludwig A, Sprang C, Clemenz
M, Krikov M, et al. PPARgamma-activating angiotensin
type-1 receptor blockers induce adiponectin. Hypertension.
2005;46:137-43. PMID: 15939809.
18 de Cavanagh EM, Inserra F, Ferder L. Angiotensin II blockade: a strategy to slow ageing by protecting mitochondria?
Cardiovasc Res. 2011;89:31-40. PMID: 20819950.
19 Imayama I, Ichiki T, Inanaga K, Ohtsubo H, Fukuyama K,
Ono H, et al. Telmisartan downregulates angiotensin II type 1
receptor through activation of peroxisome proliferator-activated receptor gamma. Cardiovasc Res. 2006;72:184-90. PMID:
16938288.
20 Maeta S, Munemura C, Fukui T, Ishida C, Murawaki Y. Combination therapy with olmesartan and temocapril ameliorates
renal damage and upregulates the klotho gene in 5/6 nephrectomized spontaneously hypertensive rats. Yonago Acta Med.
2009;52:27-35.

The authors declare no conflict of interest.
REFERENCES
1 Hao CM, Haase VH. Sirtuins and relevance to the kidney. J
Am Soc Nephrol. 2010;21:1620-7. PMID: 20595677.
2 Sinclair DA, Guarente L. Extrachromosomal rDNA circlesA cause of aging in yeast. Cell. 1997;91:1033-42. PMID:
9428525.
3 Kume S, Haneda M, Kanasaki K, Sugimoto T, Araki S,
Isshiki K, et al. SIRT1 inhibits transforming growth factor beta-Induced apoptosis in glomerular mesangial cells via Smad7
deacetylation. J Biol Chem. 2007;282:151-8. PMID: 17098745.
4 Galle J. Reduction of proteinuria with angiotensin receptor
blockers. Nat Clin Pract Cardiovasc Med. 2008;5 Suppl 1:S3643. PMID: 18580865.
5 Kitada M, Kume S, Watanabe A, Kanasaki K, Koya D.
Sirtuins and renal diseases: relationship with aging and diabetic nephropathy. Clin Sci (Lond). 2013;124:153-64. PMID:
23075334.
6 Miyazaki R, Ichiki T, Hashimoto T, Inanaga K, Imayama I,
Sadoshima J, Sunagawa K. SIRT1, a longevity gene, downregulates angiotensin II type 1 receptor expression in vascular smooth muscle cells. Arterioscler Thromb Vasc Biol.
2008;28:1263-9. PMID: 18420994.
7 Zhang D, Li S, Cruz P, Kone BC. Sirtuin 1 functionally andphysically interacts with disruptor of telomeric silencing-1 toregulate alpha-ENaC transcription in collecting duct. J Biol
Chem. 2009;284:20917-26. PMID: 19491102.

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