Transplantation of exogenous adipose tissue derived mesenchymal stem cells for treatment of acute myocardial infarction in rat

AIM: To establish a method of isolating,culturing the adipose tissue-derived mesenchymal stem cells in vitro and to investigate the possibility of exogenous transplanting the adipose tissue derived mesenchymal stem cells for treatment of rat acute myocardial infarction.METHODS: 18 male rats were separated randomly into 3 groups: sham surgery group (control,n=6),acute myocardial infarction control group (AMI,n=6) and myocardial infarction plus cell transplantation group (AMI+cell,n=6).The infarcted hearts were made by occlusion of left coronary artery.The mesenchymal stem cells were isolated from the rats’ peritoneum by using digestion methods and reproduced in vitro,then the cells were labeled with BrdU and implanted into the infarcted heart of the rats.Heart functions were measured 4 weeks after implantation.The hearts were also harvested for pathological and histoimmunochemical observations to determine the survival and location of the implanted cells.RESULTS: Plenty of mesenchymal stem cells were obtained from the adipose tissue of rats’ peritoneum.Compared with the AMI group,the left ventricular systolic pressure in the cell therapy group was increased significantly (P<0.01),the left ventricular end-diastolic pressure was decreased (P<0.01),and the ratio of the left ventricular pressure rise and decay (±dp/dt) was decreased (P<0.05).The number of blood vessels was increased at the boundary of infarction site by pathological observation.The labeled cells were founded in the infarcted myocardium and the blood vessel wall.CONCLUSION: The adipose tissue is a new optional stem cell source.The methods of exogenous transplantation of adipose tissue derived mesenchymal stem cells for treatment of AMI is effective and feasible.     

Expression of TLR2 and TLR4 on mast cells in human chronic periapical diseases

AIM: To observe the expression of TLR2 and TLR4 on mast cells(MCs) in the periapical tissues from different types of human chronic periapical diseases, and to analyze the role of TLR2 and TLR4 on tryptase-positive MCs in the immunopathogenesis of human chronic periapical diseases. METHODS: A total of 60 donors, including healthy control group, periapical granuloma group and periapical cyst group, were enrolled in the study. The periapical tissue specimens were fixed in 10% buffered formalin and stained with hematoxylin and eosin for histopathology, or stained with double-immunofluorescence for identification of TLR2-tryptase and TLR4-tryptase double-positive MCs in the periapical tissues. RESULTS: Compared with the healthy control, the densities of TLR2-tryptase and TLR4-tryptase double-positive MCs in periapical tissues were significantly increased in human chronic periapical diseases(P<0.01). The densities of TLR2-tryptase and TLR4-tryptase double-positive MCs in periapical cyst group were significantly higher than those in periapical granuloma group(P<0.01). CONCLUSION: TLR2 and TLR4 were expressed on the MCs in the periapical tissues of human chronic periapical diseases. TLR2-tryptase and TLR4-tryptase double-positive MCs may participate in the pathogenesis of chronic periapical diseases.     

Expression of transforming growth factor-β on mast cells in human chronic periapical diseases

AIM: To investigate the distribution of mast cells (MCs) and the expression of transforming growth factor-β (TGF-β) on tryptase positive MCs in different types of human periapical diseases. METHODS: Total 78 cases of specimens were involved in this study, including healthy control, periapical cyst and periapical granuloma. The tissue samples were fixed in 10% formalin for at least 48 h, stained with hematoxylin and eosin for histopathological examination, stained with toluidine blue staining for identifying MCs and MCs degranulation, and stained with double immunofluorescence for identification of tryptase-TGF-β double positive MCs. RESULTS: The density of tryptase-TGF-β double positive MCs in the periapical lesions was significantly higher than that in the healthy controls (P<0.01). The number of TGF-β positive MCs in the periapical cyst was significantly higher than that in the periapical granuloma (P<0.01). Compared with toluidine blue staining, the number of MCs with double immunofluorescence staining significantly increased (P<0.01). CONCLUSION: The TGF-β positive MCs may play an important role in the pathogenesis of human chronic periapical diseases, particularly in the formation of fibrous tissue in periapical cyst. Double immunofluorescence staining is more sensitive than the traditional toluidine blue staining for identifying MCs.     

Role of type II innate lymphoid cells in browning of white adipose tissue

Type II innate lymphoid cells (ILC2s) are widely distributed in the blood, intestines, trachea, lung, spleen, liver, animal fat and skin, and involved in the innate immune responses. ILC2s have attracted much attention for its important roles in the conversion of white adipose to beige adipose. Studies have shown that ILC2s are essential for the proliferation and differentiation of adipocyte precursor cells, and they also play a vital role in anti-parasitic infection and allergic inflammation. This review discusses the discovery, differentiation, development, distribution and function of ILC2s, and their relationships with the browning of white adipose tissue for providing valuable references on understanding the pathogenesis, prevention and treatment of obesity and fat metabolism disorders.     

Effect of high-fructose diet on adipose tissue renin-angiotensin system in rats

AIM: To observe the effects of high-fructose diet on adipose tissue inflammation and renin-angiotensin system (RAS), and to reveal the role of Toll-like receptor 2 (TLR2) in this process.METHODS: Male SD rats (n=16) were randomly divided into control group, high fructose group, high fructose+siRNA negative control group, and high fructose+TLR2-siRNA group. The rats in control group were fed with a standard chow diet. The rats in high fructose group were fed with a diet with 60% fructose, and the rats in high fructose+TLR2-siRNA group and high fructose+siRNA negative control group were transfected with TLR2 siRNA and scrambled siRNA, respectively. Serum uric acid was measured and visceral adipose tissue was weighed at the 14th week. The levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), angiotensinogen (AGT), and angiotensin Ⅱ (Ang Ⅱ) were measured by ELISA. Infiltrating macrophages in the adipose tissues were measured with immunohistochemistry. The mRNA expression of IL-6, TNF-α, monocyte chemoattractant protein-1 (MCP-1), AGT, angiotensin-converting enzyme 1 (ACE1), angiotensin Ⅱ type 1 receptor (AT1R), and angiotensin Ⅱ type 2 receptor (AT2R) was detected by RT-qPCR. The protein level of TLR2 was determined by Western blot.RESULTS: High fructose-fed rats showed elevated serum uric acid, raising fat content, higher serum concentrations of IL-6, TNF-α, AGT and AngⅡ, and more infiltrating macrophages in the adipose tissues (P<0.05). Moreover, the mRNA levels of IL-6, TNF-α,MCP-1, AGT, ACE1, AT1R and AT2R in the adipose tissues were increased (P<0.05). When high fructose-fed rats were transfected with TLR2-siRNA, the dramatic decreases in TLR2 protein level and number of infiltrating macrophages in the adipose tissues were found. Both in serum and adipose tissues, the mRNA levels of inflammatory cytokines and RAS components were all significantly decreased (P<0.05).CONCLUSION: High-fructose diet up-regulates RAS in adipose tissues via activation of TLR2 inflammation signaling pathway.     

Functional changes of perivascular adipose tissue in hypertensive rats and the effects of statins therapy

AIM:To study the functional changes of perivascular adipose tissue (PVAT) in SHR and the effects of statins therapy.METHODS:Adult SHR at 10 weeks of age were treated with atorvastatin (50 mg·kg-1·d-1) or Xuezhikang (2 400 mg·kg-1·d-1) for 16 weeks.Age-matched untreated SHR and WKY were used as controls.Tail-cuff systolic blood pressure (SBP) was measured at the beginning and the end of experiment.Thoracic aorta was divided into two segments: vessel without PVAT ［Fat (-)］ and vessel with PVAT ［Fat (+)］.The differences in contractile force induced by phenylephrine in these vessels from the four groups of rats were compared.RESULTS:SBP in SHR was significantly higher than that in WKY at the beginning of the experiment.SBP of SHR treated with statins and WKY control did not show statistical difference during the treatment period.Contractile force of Fat(+) vessels in WKY and SHR groups treated with statins was lower than that in Fat(-) vessels.There was no difference in the contractile force between Fat(+) and Fat(-) vessels in SHR control.Bathing solution transferred from Fat(+) vessels in WKY,SHR-A,and SHR-X caused a relaxation response in Fat (-) vessels,but not in control SHR.CONCLUSIONS:PVAT in WKY released a transferable relaxation factor which attenuated the responsiveness of the vessels to phenylephrine.The release or the action of this relaxation factor was reduced in the SHR.Treatment with statins restored the release or the action of this relaxation factor in the SHR.     

Expression of IL-1β and IL-17 on mast cells in human periapical diseases

AIM：To identify and quantify the expression of IL-1β and IL-17 in mast cells (MCs) in different types of human pericapical diseases using double immunofluorescence staining. METHODS：The specimens (n=102), including healthy control (n=35), periapical cyst (n=35) and periapical granuloma (n=32), were involved in the present study. The tissue samples were fixed in 10 % buffered formalin for at least 48 h and then embedded in paraffin. Serial 5-μm-thick sections were deposited onto SuperFrost/Plus microscope glasses. Routine staining of the sections using hematoxylin & eosin (HE) was performed for morphological evaluation. The number of IL-1β and IL-17 positive MCs was identified by double immunofluorescence staining. RESULTS：Compared with the healthy controls, the inflammation score of periapical lesions was significantly increased in the periapical patients (P<0.01). The density of IL-1β and IL-17 positive MCs in the periapical lesions were obviously higher than that in the healthy controls (P<0.01). However, no significant difference between periapical cyst and periapical granuloma was observed. The Pearson correlation analysis showed that there was a positive correlation between the density of IL-1β and IL-17 double positive MCs and inflammation score in different groups of specimens (P<0.01). CONCLUSION：There is significantly increased number of MCs, along with increased density of IL-1β and IL-17 positive MCs in human periapical lesions. The increased density of IL-1β and IL-17 positive MCs has the similar tendency as the severity of tissue inflammation in human periapical lesions, suggesting that IL-1β and IL-17 positive MCs may play an important role in the pathogenesis of human periapical diseases.     

Advance in study of batokines

Brown adipose tissue is a type of adipose tissue and is present in all mammals. It is not only the main site for adaptive thermogenesis in vivo, but also secretes and releases many cytokines in the form of endocrine to regulate a variety of metabolic processes and prevent and treat obesity and metabolic diseases. Therefore, identification of the types and effects of brown adipocytokines (batokines) may be crucial for the treatment of a variety of obesity-related metabolic diseases. Based on the latest research progress, batokines and their functions are reviewed.     

Toll-like receptor 4 expression on mast cells in human gingival tissues with chronic periodontitis

AIM: To observe the expression of Toll-like receptor 4 (TLR4) on mast cells in human gingival tissues with chronic periodontitis. METHODS: A total of 68 volunteers, including 23 cases of mild chronic periodontitis, 25 cases of severe chronic periodontitis and 20 healthy controls, were involved in this study, and their gingival specimens were taken and fixed in 4% neutral formalin. The histological changes of gingival tissues were observed by HE staining. The expression of TLR4 in gingival tissues was detected by immunohistochemical staining, and TLR4 expression on mast cells was detected by immunofluorescence double staining. RESULTS: The expression of TLR4 in gingival tissues and on mast cells in chronic periodontitis groups was significantly higher than that in normal control group (P<005), and that in severe chronic periodontitis group was significantly higher than that in mild chronic periodontitis group (P<005). CONCLUSION: The expression of TLR4 in gingival tissues and on mast cells is increased with the severity of chronic periodontitis, suggesting that TLR4, especially TLR4 on mast cells, may play an important role in human chronic periodontitis.     

Role of mast cells in pain of adjuvant arthritis in mice

AIM To investigate the role of mast cells in the pain of adjuvant arthritis (AA) in mice induced by complete Freund's adjuvant (CFA). METHODS The animals were divided into 4 groups: normal control group (control group), AA model group (model group) and AA model + cromolyn sodium (CS) group (CS group), AA model + mast cell lacking group (W-4Bao group), with 6 mice in each group. The animals in the first 3 groups were C57BL/6 mice, while those in W-4Bao group were Kit^W-4Bao mice lacking of mast cells. The pain model of chronic AA was induced by intraplantar injection of CFA into the right hind paws of the mice, while the mice in control group was injected with saline. One day after CFA injection, the mice in CS group were intraperitoneally injected with CS (20 mg/kg), and those in other groups received an equal volume of saline once a day for 14 d. The paw edema, paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) were evaluated at 0, 1, 3, 7, 10 and 14 d after CFA injection. The mouse right ankle joint was harvested after 14 d for HE and toluidine blue staining, and the concentrations of histamine, tryptase, substance P (SP), calcitonin gene-related peptide (CGRP) were detected by ELISA. RESULTS One day after CFA injection, the inflammation of the right hind paw in model group was more serious compared with control group, and the PWT and PWL were notably decreased (P<0.05). In addition, the numbers of mast cells and degranulated mast cells were increased obviously, and the concentrations of histamine, tryptase, SP and CGRP were increased (P<0.05). However, compared with model group, hyperalgia and the release of neuropeptides in CS group and W-4Bao group were significantly decreased (P<0.05). CONCLUSION The activation of mast cells promotes the pain of AA in mice, and its mechanism may be associated with the release of neuropeptides and relevant inflammatory factors.     

Autophagy promotes survival of adipose cells by inhibiting apoptosis under in vitro starvation

AIM: To detect the changes of autophagy in adipose cells under starvation, and to clarify the effects of autophagy on the cell survival and apoptosis under starvation. METHODS: Rapamycin (RAP) was applied to promote autophagy of adipose cells. These cells were then incubated under oxygen-glucose deprivation (OGD) condition. After exposure of the cells to OGD, the changes of autophagy and apoptosis were determined by Western blotting, transmission electron microscopy and TUNEL assay. RESULTS: Compared with the control cells, OGD-challenged cells had much higher level of autophagy. The apoptotic rate in OGD group was much higher than that in control group, which was reflected by increased protein level of activated caspase-3 and percentages of TUNEL positive cells. Preconditioning with RAP effectively improved OGD-induced autophagy, but did not affect the cell survival and apoptosis under normal condition, and obviously decreased the apoptotic rate of the cells under OGD condition. CONCLUSION: Autophagy protects adipose cells against starvation-induced apoptosis. Promotion of autophagy is helpful for attenuating starvation-induced apoptosis of the cells under OGD condition.     

Adult human mesenchymal stem cell differentiates into adipocytes

AIM:To investigate the differentiation from human mesenchymal stem cells (hMSC) to adipocytes.METHODS: hMSC were separated from rib marrow and expanded in culture medium. To detect the surface antigens, the labeled cells were analysed on a FACScan flow cytometer. hMSC were induced with dexamethasone, insulin, 1-methy1-3-isobutylxanthine and indomethacin which acted as adipocyte differentiation inducer. The cells were stained with Oil Red O. The number of adipocytes were counted on a phase-contrast microscope.RESULTS: hMSC were expanded as undifferentiated cells in culture for more than 5 passages. The isolated cultured MSC comprised a single phenotypic population and displayed a fibroblast-like morphology. These expanded, attached MSC were uniformly positive for CD29, CD44, CD90, CD105, CD166 and didn't express CD14, CD34, CD45, CD11a. After induced with induction medium, lipid vacuoles were first detectable within the cells at 48 hours. Two weeks later, more than 85% MSC differentiated into adipocytes which displayed a perinuclear accumlation of lipid vacuoles, as detected by Oil Red O. CONCLUSION:hMSC can be induced to differentiate into adipocytes.     

Quantification of tryptase and T-cell immunoglobulin mucin 1 double-positive mast cells in different degrees of human periodontitis

AIM：To examine the expression of T-cell immunoglobulin mucin 1 (TIM-1) on tryptase-positive mast cells (MCs) in different severities of human chronic periodontitis. METHODS：Human gingival specimens (n=92) were involved in this study, including healthy control (n=27), mild chronic periodontitis (n=34) and severe chronic periodontitis (n=31). The gingival specimens were fixed in 4% formaldehyde. Paraffin embedding and serial sectioning with hematoxylin and eosin staining were performed for histopathological examination, and double-immunofluorescence staining was conducted for identification of tryptase-TIM-1 double-positive MCs in the gingival tissues. RESULTS：Compared with the healthy controls, the densities (cells/mm2) of tryptase-TIM-1 double-positive MCs were significantly increased in both mild chronic periodontitis group (P<0.05) and severe chronic periodontitis group (P<0.01). However, compared with mild chronic periodontitis group, both the score of gingival tissue inflammation and the density of tryptase-TIM-1 double-positive MCs in the gingival tissues were significantly increased in severe periodontitis group (P<0.05). CONCLUSION：Significantly increased number of tryptase-TIM-1 double-positive MCs has the similar tendency as the severity of periodontitis inflammation in human chronic periodontitis, suggesting that tryptase-TIM-1 double-positive MCs may play an important role in human chronic periodotitis.     

Role of mast cell and its subpopulations in simple and irradiated-wound of rats

AIM:To examine the role and dynamic changes of mast cell(MC) and its subpopulations in simple and irradiated-wound of rats.METHODS:MC and its subpopulations were estimated using alcian blue-safranin (ABS)double staining. RESULTS:(1)The total number of MC in two groups decreased coincidently on day 2 after wounding, and the total MC increased rapidly and reached maximal gradually on day 5 and 7 after wounding, the increment of MC remained consistently 28 day after wounding.(2)Both mucosal MC( MMC) and Mix MC decreased obviously on day 2 after wounding, hereafter,they remained the low level all the time. However, the CTMC kept in the high level after wounding. (3)The Mix MC on day 5 and the total MC during day 5-15 after wounding were lower in irradiated group than in simple wound group.CONCLUSION: MC and its subpopulations could delay the healing process of simple and irradiated wound.     

Expression of stem cell factor in mast cells isolated from patients with chronic periapical diseases

AIM:To investigate the expression of stem cell factor (SCF) in tryptase -positive mast cells (MCs) in different types of human periapical diseases for determining the role of SCF and MCs in the pathogenesis of periapical diseases. METHODS:A total 50 cases of specimens were involved in this study, including healthy control (n=20), periapical cyst (n=15) and periapical granuloma (n=15). The tissue material was fixed in 10% formalin for at least 48 h, stained with hematoxylin and eosin for the observation of histopathology, stained with immunohistochemistry for identifying MCs and MCs degranulation, and stained with double immunofluorescence for identification of tryptase-SCF double positive MCs. RESULTS:Compared with healthy control, significantly higher densities of both total and degranulated MCs in human periapical lesions were observed. The densities of both total and degranulated MCs in the periapical cyst were significantly higher than that in the periapical granuloma. The density of tryptase-SCF double positive MCs in the periapical lesions was significantly higher than that in the healthy controls. The density oftryptase-SCF double positive MCs in the periapical cyst was significantly higher than that in periapical granuloma. No significant difference in the density of MCs between immunohistochemistry staining and double immunofluorescence staining was observed. CONCLUSION: The tryptase-SCF double positive MCs play an active role in the pathogenesis of the periapical inflammatory lesions, particularly in the formation of fibrous tissue in periapical cyst. The potential role of the tryptase-SCF double positive MCs relates with the initiation, development, and persistence of the periapical inflammatory process.     

Effect of adipose differentiation-related protein on proliferation and apoptosis in H9c2 cells

AIM: To construct an adipose differentiation-related protein (ADRP) eukaryotic expression vector and to explore the effect of ADRP on apoptosis of H9c2 cells induced by palmitic acid (PA). METHODS: The ADRP gene obtained by the method of RT-PCR was cloned into pEGFP-C1 plasmid. The recombinant plasmid was transformed into E.coli DH5α for amplification. The recombinant plasmid was extracted from E.coli DH5α and transfected into H9c2 cells by Lipofectamine^TM2000. The stable transformants were selected by G418 screening. Expression of green fluorescent protein was observed under fluorescence microscope and the ADRP expression was identified by RT-qPCR and Western blotting analysis. The effect of PA on the proliferation of H9c2 cells was detected by MTT assay. The apoptotic percentage of H9c2 cells caused by PA was determined by flow cytometry. RESULTS: The eukaryotic expression vector pEGFP-C1-ADRP was successfully constructed. Green fluorescent was observed in the cells transfected with pEGFP-C1 or pEGFP-C1-ADRP under fluorescence microscope. RT-qPCR and Western blotting analysis showed that recombinant cells exhibited high mRNA and protein levels of ADRP. After treated with PA at different concentrations, the apoptosis rates and the proliferation inhibition of recombinant cells were both lower than those of the other two cells. CONCLUSION: The transfected H9c2 cells with stable ADRP expression were successfully established. The over-expression of ADRP prevents the cells from apoptosis and inhibition of proliferation caused by PA, indicating that ADRP plays a protective role in H9c2 cells.     

Effect of portal vein transplantation with allogeneic adipose tissue-derived mesenchymal stem cells on liver fibrosis in SD rats

AIM: To explore the influence of adipose tissue-derived mesenchymal stem cells (ADMSCs) transplantation on hepatic fibrosis in rats. METHODS: ADMSCs from abdominal lipid tissues were extracted, cultured and passaged. The hepatic fibrosis rat model was built up and randomly divided into 3 groups: hepatic cirrhosis group (n=14); portal vein transplantation group (n=11) and caudal vein transplantation group (n=14). Computer tomography(CT) perfusion index, histological scores and microvessel density were detected and compared after transplantation of ADMSCs among the 3 groups. RESULTS: After transplantation of ADMSCs, the total hepatic blood perfusion, especially portal vein perfusion, significantly increased in portal vein transplantation group determined by CT perfusion scan (P<0.05), but slightly increased in caudal vein transplantation group. The histological scores showed significant alleviation of fibrosis evidence in portal vein transplantation group, and slightly change of adipose degeneration in caudal vein transplantation group. Microvessel density decreased significantly in portal vein transplantation group as compared to the other 2 groups (P<0.05). CONCLUSION: Transplantation of ADMSCs greatly helps the alleviation of hepatic fibrosis. Portal vein transplantation benefits more than caudal vein transplantation.     

Effects of adipose tissue-derived mesenchymal stem cells on calcium channels of pulmonary artery in rats with pulmonary arterial hypertension induced by monocrotaline

AIM: To investigate the effects of adipose tissue-derived mesenchymal stem cells (ADMSCs) on calcium channels of pulmonary artery in monocrotaline (MCT)-induced pulmonary hypertensive rats.METHODS: ADMSCs were isolated from adipose tissue by collagenase digestion. Twenty-four Sprague-Dawley rats were randomly divided into 3 groups: normal control (Ctr) group, pulmonary arterial hypertension (PAH) group and ADMSCs transplantation group. Mean pulmonary arterial pressure (MPAP) was measured by catheterization, and right ventricular hypertrophy index (RVHI) was calculated. The expression of voltage-gated calcium channel α1c subunit (CaVα1c), sarcoplasmic/endoplasmic reticulum calcium ATPase 2a (SERCA-2a), inositol 1,4,5-triphosphate receptor 1(IP3R-1), transient receptor potential channel 1 (TRPC1) and TRPC6 at mRNA and protein levels in the pulmonary trunks was determined by RT-PCR and Western blotting, respectively.RESULTS: MPAP and RVHI were higher in PAH group than those in Ctr group, while those in ADMSCs group were significantly decreased as compared with PAH group. The expression of CaVα1c, TRPC1 and TRPC6 at mRNA and protein levels was obviously increased in PAH group as compared with Ctr group, while that in ADMSCs group was significantly decreased as compared with PAH group. Compared with Ctr group, the expression of SERCA-2a and IP3R-1 at mRNA and protein levels was obviously decreased in PAH group, while that in ADMSCs group was significantly increased as compared with PAH group.CONCLUSION: MPAP and RVHI are attenuated by ADMSCs in MCT-induced pulmonary hypertensive rats. The reduction of pulmonary arterial pressure by ADMSCs transplantation in MCT-induced pulmonary hypertensive rats may be related to the changes of calcium channels.     

Effect of electroacupuncture in different intensities on endoplasmic reti-culum stress in adipose tissues from high-fat diet-induced obese rats

AIM: To investigate the effect of electroacupuncture (EA) in different intensities on unfolded protein response (UPR) signaling pathway in adipose tissues from high-fat diet-induced obese rats. METHODS: Sixty SD rats were randomly divided into 2 groups: common diet group (n=10) and high-fat diet group (n=50). Thirty obese rats in high-fat diet group were chosen and divided into high-fat diet group, 5 mA EA group and 1 mA EA group (n=10 each). EA at frequency of 20 Hz and intensities of 5 mA or 1 mA was applied to ST 36 and SP 6 for 15 min once daily for 2 weeks. The body weight was detected once a week. The expression of p-PERK and CHOP/GADD153 in epididymal adipose tissues was determined by Western blotting. The content of Bcl-2 and caspase-12 in the adipose tissues was measured by ELISA. RESULTS: After EA, the body weight and the expression of p-PERK and CHOP/GADD153 in obese rats were significantly decreased (P<0.01 or P<0.05). The rats in 5 mA EA group exhibited a better improvement on the protein expression than the rats in 1 mA EA group.CONCLUSION: EA has a beneficial regulatory effect on the rats with simple obesity. Moreover, the EA density of 5 mA is superior to 1 mA.