Objective To study the protective effect of electroacupuncture(EA) at “Biao”-acupoints

“Fenglong”(ST40) and “Zhongwan”(CV12)

used for treating symptoms of the disease

and “Ben”-acupoints

“Zusanli”(ST36) and “Guanyuan”(CV4)

for treating the root cause of the disease on oxidative stress injury of renal mitochondria through SIRT1/PGC-1α signal pathway in rats with diabetic nephropathy(DN). Methods A total of 33 male Wistar rats were randomized into normal(n=10)

model(n=12) and EA(n=11) groups. The DN model was established by feeding the rats with high-sugar and high-fat diet for 6 weeks combined with streptozotocin(STZ

35 mg/kg

i.p.). EA(4 Hz/60 Hz

1 mA)was applied to ST36-ST40 and CV4-CV12 for 15 min

once every other day for 8 weeks. The rats' body weight was recorded

urine in 24 hours(24-h UP) was collected to measure the urine protein level

and the fasting blood glucose(FBG) level detected by using a glucometer. The levels of serum glycosylated hemoglobin(HbA1 c)

creatinine(Scr) and urea nitrogen(BUN) were assayed using immunoturbidi-metry

picric acid method and urease method

respectively

and those of serum triglyceride(TG)

total cholesterol(TC)

low density lipoprotein cholesterol(LDL-C) and high density lipoprotein cholesterol(HDL-C) detected using an automatic biochemical analyzer. The kidney tissue was collected for assaying the activity of superoxide dismutase(SOD) with xanthine oxidase method

glutathione(GSH) activity with dithio-dinitrobenzoic acid method

catalase(CAT) activity with ammonium molybdate spectrometric method

and malondialdehyde(MDA) content with thiobarbituric acid method. Histopathological changes of the kidney tissue were observed by microscope after hematoxylin-eosin staining(HE)

periodate Schiff staining(PAS) and Masson staining

separately

and its subcellular structure was observed under transmission electron microscopy. The expression levels of renal SIRT1 and PGC-1α mRNAs and proteins were detected by quantitative real-time PCR and Western blot

and the immunoactivity of renal α-smooth muscle actin(α-SMA)

and immunofluorescence density of renal collagen Ⅰ(Col Ⅰ)

collagen Ⅳ(Col Ⅳ) and fibronec-tin(FN) detected by immunohistochemistry and immunofluorescence assay

respectively.Results Compared with the normal group

the levels of FBG

HbA1 c

BUN

Scr

24-h UP

TG

TC

LDL-C

MDA

α-SMA

Col Ⅰ

Col Ⅳ and FN proteins were significantly increased(P<0.01)

and the levels of body weight

HDL-C

SOD

GSH

CAT

SIRT1 and PGC-1α mRNAs and proteins were decreased in the model group(P<0.01

P<0.05). In comparison with the model group

the levels of FBG

HbA1 c

BUN

Scr

24-h UP

TG

TC

LDL-C and MDA

and the expressions of α-SMA

Col Ⅰ

Col Ⅳ and FN proteins were markedly down-regulated(P<0.05

P<0.01)

and those of body weight

HDL-C

SOD

GSH

CAT

and the expressions of SIRT1 and PGC-1α mRNAs and proteins significantly up-regulated(P<0.01

P<0.05) in the EA group. HE staining showed mesangial dilatation

glomerular hypertrophy and mesangial matrix accumulation; PAS staining showed an increase of the glomerular extracellular matrix deposition; and Masson staining displayed an enhancement of glomerular fibrosis and interstitial space expansion; and electron microscope revealed foot process fusion

basement membrane thickening and organelle injury in the rat's kidney of the model group

which were relatively milder in the EA group. Conclusion EA of ST36-ST40 and CV4-CV12

“Biao-Ben” acupoints combination

can alleviate oxidative stress and mitochondrial dysfunction in DN rats

which may be associated with its functions in up-regulating SIRT1/PGC-1α signaling

and decreasing renal fibrosis.