OBJECTIVETo assess whether Angiotensin II (Ang II) and carbon tetrachloride (CCl(4)) used in combination could accelerate the process of fibrosis and whether Ang II play a role in exagerating hepatic fibrosis in rats.

METHODSAng II was injected into the abdominal cavity of Sprague-Dawley (SD) rats together with subcutaneous injection of CCl(4). Rats were killed after 14 and 28 d. Blood serum and liver specimen were collected. The extent of fibrosis in the stained liver tissue sections was determined with the KS 400 Image Analysis System.

RESULTSRats receiving Ang II and CCl(4) for 28 d showed extensive liver fibrosis. Along with the increase of hepatic fibrosis, the serum concentration of Ang II went up gradually.

CONCLUSIONSA combination of Ang II and CCl(4) would accelerate the process of hepatic fibrosis. Ang II probably took part in the occurrence of heparic fibrosis.

Alanine Transaminase ; blood ; Angiotensin II ; blood ; toxicity ; Animals ; Aspartate Aminotransferases ; blood ; Carbon Tetrachloride ; toxicity ; Liver Cirrhosis, Experimental ; chemically induced ; Male ; Rats ; Rats, Sprague-Dawley ; Renin-Angiotensin System ; physiology

BACKGROUND: Macrophages are involved in the pathogenesis of idiopathic pulmonary fibrosis, partially by activating lung fibroblasts. However, how macrophages communicate with lung fibroblasts is largely unexplored. Exosomes can mediate intercellular communication, whereas its role in lung fibrogenesis is unclear. Here we aim to investigate whether exosomes can mediate the crosstalk between macrophages and lung fibroblasts and subsequently induce fibrosis. METHODS: In vivo, bleomycin (BLM)-induced lung fibrosis model was established and macrophages infiltration was examined. The effects of GW4869, an exosomes inhibitor, on lung fibrosis were assessed. Moreover, macrophage exosomes were injected into mice to observe its pro-fibrotic effects. In vitro, exosomes derived from angiotensin II (Ang II)-stimulated macrophages were collected. Then, lung fibroblasts were treated with the exosomes. Twenty-four hours later, protein levels of α-collagen I, angiotensin II type 1 receptor (AT1R), transforming growth factor-β (TGF-β), and phospho-Smad2/3 (p-Smad2/3) in lung fibroblasts were examined. The Student's t test or analysis of variance were used for statistical analysis. RESULTS: In vivo, BLM-treated mice showed enhanced infiltration of macrophages, increased fibrotic alterations, and higher levels of Ang II and AT1R. GW4869 attenuated BLM-induced pulmonary fibrosis. Mice with exosomes injection showed fibrotic features with higher levels of Ang II and AT1R, which was reversed by irbesartan. In vitro, we found that macrophages secreted a great number of exosomes. The exosomes were taken by fibroblasts and resulted in higher levels of AT1R (0.22 ± 0.02 vs. 0.07 ± 0.02, t = 8.66, P = 0.001), TGF-β (0.54 ± 0.05 vs. 0.09 ± 0.06, t = 10.00, P < 0.001), p-Smad2/3 (0.58 ± 0.06 vs. 0.07 ± 0.03, t = 12.86, P < 0.001) and α-collagen I (0.27 ± 0.02 vs. 0.16 ± 0.01, t = 7.01, P = 0.002), and increased Ang II secretion (62.27 ± 7.32 vs. 9.56 ± 1.68, t = 12.16, P < 0.001). Interestingly, Ang II increased the number of macrophage exosomes, and the protein levels of Alix (1.45 ± 0.15 vs. 1.00 ± 0.10, t = 4.32, P = 0.012), AT1R (4.05 ± 0.64 vs. 1.00 ± 0.09, t = 8.17, P = 0.001), and glyceraldehyde-3-phosphate dehydrogenase (2.13 ± 0.36 vs. 1.00 ± 0.10, t = 5.28, P = 0.006) were increased in exosomes secreted by the same number of macrophages, indicating a positive loop between Ang II and exosomes production. CONCLUSIONS Exosomes mediate intercellular communication between macrophages and fibroblasts plays an important role in BLM-induced pulmonary fibrosis.
Angiotensin II ; Animals ; Bleomycin/toxicity* ; Exosomes ; Fibroblasts ; Lung ; Macrophages ; Mice ; Mice, Inbred C57BL ; Pulmonary Fibrosis/chemically induced* ; Receptor, Angiotensin, Type 1

OBJECTIVETo explore expression changes of myocardial renin angiotensin system induced by prenatal exposure to lipopolysaccharide in offspring rats.

METHODSTwelve pregnant SD rats were randomly divided into three groups: LPS model group: intraperitoneal injection of LPS (0.79 mg/kg) at 8, 10, 12 days of pregnancy; control group: intraperitoneal injection of sterile saline (0.5 ml) at 8, 10, 12 days of pregnancy; LPS + PDTC group: intraperitoneal injection of LPS (0.79 mg/kg) at 8, 10, 12 days of pregnancy plus daily intraperitoneal injection of NF-κB inhibitor -pyrrolidine dithiocarbamate (PDTC, 100 mg/kg) on day 8 to 14 pregnancy day. Protein expression of AngiotensinII(AngII) in heart was detected by immunohistochemistry; myocardial ACE,ACE2 mRNA expression was detected by real-time PCR; protein expression of ACE and ACE2 in heart was detected by Western blot in offspring rats of various groups.

RESULTSCompared with control group (0.07 ± 0.02,0.11 ± 0.01), AngII protein levels (0.14 ± 0.04) were significantly increased at 6 weeks (P < 0.01) and 16 weeks (0.17 ± 0.04, P < 0.05) in offspring rats of LPS model group, which could be significantly attenuated by PDTC intervention (0.10 ± 0.01,0.13 ± 0.03, respectively, all P < 0.05).Similarly, myocardial ACE mRNA expression in 16 weeks offspring rats of LPS model group was significantly upregulated compared with control group (1.10 ± 0.26 vs.0.72 ± 0.22, P < 0.05), which was significantly attenuated by PDTC intervention (0.67 ± 0.01, P < 0.01 vs.LPS group). Myocardial protein expression ACE2 in 16 weeks offspring rats of LPS model group was significantly downregulated compared to control group, which was slightly upregulated by PDTC intervention (P > 0.05).

CONCLUSIONPregnancy exposure to lipopolysaccharide increases myocardial ACE and AngII expression while reduces myocardial ACE2 expression in offspring rats, which might be one of the pathomechanisms of offspring hypertension.

Angiotensin II ; metabolism ; Animals ; Female ; Lipopolysaccharides ; toxicity ; Myocardium ; metabolism ; Peptidyl-Dipeptidase A ; metabolism ; Pregnancy ; Prenatal Exposure Delayed Effects ; Rats ; Rats, Sprague-Dawley ; Renin-Angiotensin System

Thoracic aortic dissection (TAD) is one of the most lethal aortic diseases due to its acute onset, rapid progress, and high rate of aortic rupture. The pathogenesis of TAD is not completely understood. In this mini-review, we introduce three emerging experimental mouse TAD models using β-aminopropionitrile (BAPN) alone, BAPN for a prolonged duration (four weeks) and then with added infusion of angiotensin II (AngII), or co-administration of BAPN and AngII chronically. We aim to provide insights into appropriate application of these three mouse models, thereby enhancing the understanding of the molecular mechanisms of TAD.
Aminopropionitrile/toxicity* ; Aortic Dissection/pathology* ; Angiotensin II/toxicity* ; Animals ; Aortic Aneurysm, Thoracic/pathology* ; Disease Models, Animal ; Male ; Mice ; Mice, Inbred C57BL

OBJECTIVESThe aim of the present study was to determine the effects of angiotensin-converting enzyme inhibitor, perindopril, on the progression of rat hepatic fibrosis induced by CCl4.

METHODSMale wistar rats weighting about 250g were treated with perindopril (2mg/kg, daily gavage), except for model group and control group. After 4, 6 weeks, morphological examination was based on microscopy. RT-PCR was utilized to detect gene expression of angiotensin II type 1 receptor (AT1 receptor) in the liver. Meanwhile, the protein expressions of AT1 receptor, transforming growth factor beta 1 (TGF-beta1) and platelet-derived growth factor-BB (PDGF-BB) in liver tissue were examined by Western blot. The activity of matrix metalloproteinase-2 (MMP-2) was assessed by zymography. Serum laminin (LN) and hyaluronic acid (HA) were measured using radio-immunity technique.

RESULTSRT-PCR and Western blot revealed that there was a up-regulation in AT1 receptor expression in model group compared with control group. Perindopril treatment significantly reduced mean fibrosis score, messenger RNA and protein levels of AT1 receptor, protein levels of TGF-beta1 and PDGF-BB, Serum levels of HA and LN, and MMP-2 activity.

CONCLUSIONThese results suggest that angiotensin II may play an important role in fibrosis of liver. Perindopril may have a inhibiting effect on CCl4-induced hepatic fibrogenesis of rat.

Angiotensin II ; physiology ; Angiotensin II Type 1 Receptor Blockers ; Angiotensin-Converting Enzyme Inhibitors ; pharmacology ; Animals ; Blotting, Western ; Carbon Tetrachloride ; toxicity ; Liver ; pathology ; Liver Cirrhosis, Experimental ; chemically induced ; prevention & control ; Male ; Perindopril ; pharmacology ; Platelet-Derived Growth Factor ; antagonists & inhibitors ; Proto-Oncogene Proteins c-sis ; Rats ; Rats, Wistar ; Transforming Growth Factor beta ; antagonists & inhibitors ; Transforming Growth Factor beta1

OBJECTIVETo investigate the trend and potential pathogenic role of nuclear factor (NF)-kappaB P(65)/Rel-A mRNA and angiotensin-II (AngII) receptor type 1 (AT(1)) proteins expression, and the relativity between them in early stage of renal tubulointerstitial lesions in young rats with adriamycin nephrosis and the interfering effects of treatment with angiotensin converting enzyme inhibitor (ACEI) benazepril and ACEI combined with AngII type 1 receptor antagonist (AT(1)RA) Losartan.

METHODSMale young Wistar rats with adriamycin nephrosis were used as experimental models. At different time points (weeks 1, 2, and 3 in early nephritic phase, the urinary protein and blood biochemical parameters were measured, and P(65)/Rel-A mRNA was detected; AT(1) protein expression was determined by in situ hybridization and immunohistochemical methods. The relativity between them was evaluated.

RESULTSIn the early phase of tubulointerstitial lesions, following adriamycin injection and proteinuria aggravated progressively, at week 3, the proteinuria level had reached heavy proteinuria (123.2 +/- 7.7 mg/24 h). The serum parameters reflecting renal function were elevated. The inflammatory cells infiltrated into renal tissues, especially in tubulointerstitial regions, were increased markedly. Swelling of tubular epithelial cells, broadened tubulointerstitial areas, and protein casts in tubule were observed. In situ hybridization and immunochemical staining showed that AT(1) protein was expressed in tubular epithelial cell cytoplasm and on nuclear membranes (AT(1): 1st week 19.8 +/- 1.1%, 2nd week 25.0 +/- 2.6%, 3rd week 37.1 +/- 1.0% (control: 10.3 +/- 0.8%, 10.4 +/- 1.6%, 10.2 +/- 1.5%); and P(65)/Rel-A mRNA expression in the same locations was upregulated. P(65)/Rel-A translocation from cytoplasm into nucleus increased markedly simultaneously. The positive signal of hybridization dominated in cytoplasm gradually became dominant in the nuclei as the pathological changes progressed. The semiquantitative expression of P(65)/Rel-A was 24.0 +/- 3.3% at week 1, 34.2 +/- 2.4% at week 2, 39.9 +/- 6.4% at week 3, while the values of controls were 8.5 +/- 0.4%, 8.7 +/- 1.0%, and 8.4 +/- 0.9%, respectively. There was a positive correlation between AT(1) and P(65)/Rel-A expression in localization and time phase (r = 0.857, P < 0.01). However, the tendency of those factor's expression was all decreased in each treated group, the semiquantitative results were AT(1): 14.6 +/- 2.1%, 13.7 +/- 2.3%, 11.4 +/- 1.1%; P(65)/Rel-A: 18.5 +/- 3.4%, 22.8 +/- 1.6%, 26.7 +/- 4.9% at 1, 2, 3 weeks in ACEI treated group; AT(1): 12.4 +/- 1.5%, 11.1 +/- 1.0%, 10.3 +/- 0.8%; P(65)/Rel-A: 17.9 +/- 5.0%, 21.3 +/- 6.0%, 22.5 +/- 2.5% in AT(1)RA (Losartan) group, respectively. The significant difference were observed between all groups in different time points (P < 0.05).

CONCLUSIONSThe present study suggested that NF-kappaB (P(65)/Rel-A) mRNA expression and its activity was enhanced significantly that synchronized with aggravating injures in tubulointerstitial lesions initial period induced by proteinuria-loading in nephrotic young rats. This tendency was related with AngII and its receptors system that may accelerate lesions progressing in many renal diseases.

Angiotensin II Type 1 Receptor Blockers ; pharmacology ; Angiotensin-Converting Enzyme Inhibitors ; pharmacology ; Animals ; Antibiotics, Antineoplastic ; toxicity ; Benzazepines ; pharmacology ; Biopsy ; Disease Models, Animal ; Doxorubicin ; toxicity ; Gene Expression Regulation ; drug effects ; Immunohistochemistry ; In Situ Hybridization ; Kidney ; drug effects ; metabolism ; pathology ; Losartan ; pharmacology ; Male ; NF-kappa B ; genetics ; metabolism ; Nephrosis ; chemically induced ; drug therapy ; metabolism ; Rats ; Rats, Wistar ; Receptor, Angiotensin, Type 1 ; genetics ; metabolism ; Transcription Factor RelA

Hyperglycemia is a principal characteristic of diabetes, and has an influence on many cellular functions. In order to investigate whether the intracellular signaling pathways inducing proliferation, hypertrophy and matrix synthesis of mesangial cells are altered in a diabetic environment, we evaluated the effects of a high concentration of extracellular glucose(25 mM; 450 mg/dl) on [3H]thymidine uptake, hypertrophy, and [3H]proline incorporation into a collagenase-sensitive protein, induced by angiotensin II(Ang II) or transforming growth factor(TGF)-beta, in cultured rat mesangial cells. The exposure to a high glucose concentration for 7 days significantly inhibited Ang II(10(-6) M)-induced [3H]thymidine uptake, compared to normal glucose concentration (5 mM)(M +/- SD., 1050 +/- 100 cpm/well vs 550 +/- 97, p< 0.05), and markedly prevented the inhibition of [3H]thymidine uptake by TGF-beta(1 ng/ml)(132 +/- 10 vs 340 +/- 67, p< 0.05). The administration of H-7(50 microM), a protein kinase C(PKC) inhibitor, did not reverse these effects of high glucose on [3H]thymidine uptake. On flow cytometric analysis of cell size, the mean cell size was significantly greater for the cells exposed to high glucose or treated with Ang II or TGF-beta, compared to that for the untreated cells. But the addition of Ang II or TGF-beta to the cells exposed to high glucose did not show further enlargement in size. The exposure to high glucose and the treatment with Ang II or TGF-beta significantly increased collagen synthesis, measured by [3H]proline incorporation. The Ang II -or TGF-beta-induced increase of [3H]proline incorporation did not show changes under high glucose culture condition, compared to normal glucose concentration(Ang II, 27880 +/- 3560 cpm vs 26978 +/- 2284, TGF-beta, 26559 +/- 3700 vs 25800 +/- 1660, p> 0.05). In conclusion, although the signaling pathway for DNA synthesis by Ang II or TGF-beta are influenced, possibly mediated by PKC-independent mechanism(s), the pathway inducing hypertrophy or collagen synthesis by both agents appears to be unchanged under the high extracellular glucose concentration in cultured rat mesangial cells.
Angiotensin II/*pharmacology ; Animal ; Cells, Cultured ; Collagen/*biosynthesis ; DNA/*biosynthesis ; Glomerular Mesangium/metabolism/*pathology ; Glucose/*toxicity ; Hypertrophy ; Rats ; Rats, Sprague-Dawley ; Support, Non-U.S. Gov't ; Transforming Growth Factor beta/*pharmacology

OBJECTIVETo explore the effects of Candesartan cilexetil on the rats exposed to silica.

METHODNinety-six wistar rats were randomly divided into model-group, intervention-group and control-group (32 rats a group). The intervention-group, model-group and control group were orally exposed to Candesartan cilexetil (10 mg/kg) and normal solution for a week, respectively. Then the model and intervention groups were exposed to silica by intratracheal infusion of silica dust suspension (50 mg/ml), the control group was exposed to 0.5 ml normal solution for 2 days. On the 3rd, 7th, 14th and 28th days after exposure to silica, 8 rats of each group were sacrificed, respectively. The samples of lung tissues were collected. The lung/body coefficients were detected. The pathological examinations were performed by HE and Masson staining. The levels of ACE in the lung tissues were observed by immunochemistry staining. The levels of TGF-β1 and Ang II in the BALF were examined by ELISA.

RESULTSOn the 3rd, 7th, 14th and 28th days after exposure, the levels of alveolitis and pulmonary fibrosis in the intervention group were significantly alleviated as compared with model group, and the lung/body coefficients in the intervention group, which were significantly lower than those in model group respectively (P < 0.01). As compared with control group, the levels of TGF-β1 and Ang II of the BALF in the model and intervention groups significantly enhanced (P < 0.01). As compared with model group, the levels of TGF-β1 and Ang II of the BALF in the intervention group significantly decreased (P < 0.01). As compared with control group, the levels of ACE of the lung tissues in the model and intervention groups significantly increased (P < 0.01). But the level of ACE of the lung tissues in the intervention group was significantly lower than that in the model group (P < 0.01).

CONCLUSIONThe early Candesartan cilexetil intervention could significantly decrease the levels of alveolitis and lung fibrosis, declined the levels of TGF-β(1) and Ang II of BALF and downregulated the expression level of ACE in lung tissues in rats exposed to silica.

Angiotensin II ; metabolism ; Animals ; Benzimidazoles ; pharmacology ; therapeutic use ; Bronchoalveolar Lavage Fluid ; Female ; Lung ; drug effects ; pathology ; Male ; Pulmonary Fibrosis ; chemically induced ; drug therapy ; Rats ; Rats, Wistar ; Silicon Dioxide ; toxicity ; Tetrazoles ; pharmacology ; therapeutic use ; Transforming Growth Factor beta1 ; metabolism

OBJECTIVEChildren with nephrotic syndrome are always associated with retardation of growth. Growth hormone (GH) administration to these children can stimulate their growth, but it plays an important role in glomerulosclerosis. Thus these children would take a risk to use it to improve their growth. This study was designed to investigate the effect of GH on the kidney of rats with adriamycin-induced nephropathy (AN) and its mechanism, and to observe the renoprotective effect of angiotensin II (AngII) receptor antagonist, irbesartan, in GH-treated AN rats.

METHODSRats were divided into the following groups: normal control rats, AN rats, GH-treated AN rats and GH plus irbesartan-treated AN rats. There were 8 developing male SD rats (120-130 g) in each group. Urinary protein was measured at weeks 3, 6 and 9. Blood pressure, serum creatinine, BUN, albumin, cholesterol, triglyceride, as well as ACE activity and AngII concentration of the kidney were detected at the end of the study. Renal pathological changes were evaluated also. Immunohistochemistry was used to examine the protein expressions of TGF beta(1), collagen IV and fibronectin in glomeruli.

RESULTSGlomerular sclerosis score of GH-treated AN rats (49.4 +/- 9.8) was significantly higher than that of AN rats (12.8 +/- 5.5, P < 0.01), and this score of GH-treated AN rats plus irbesartan (26.2 +/- 7.5) was significantly lower than the score of GH-treated AN rats (P < 0.01). The changes of urinary protein, hyperlipidemia and hypoalbuminemia in rats of each group consisted with the degree of glomerular injury in rats of each group. There was azotemia in GH-treated AN rats, but rats in the other groups did not have azotemia. ACE activity of kidney was significantly (P < 0.01) increased in GH-treated AN rats [(28.1 +/- 4.1) U/mg pro] and GH-treated AN rats plus irbesartan [(27.6 +/- 3.4) U/mg pro] compared with that in AN rats [(14.6 +/- 4.4) U/mg pro]. AngII concentrations in the kidney of GH-treated AN rats [(17.8 +/- 3.3) pg/mg pro] and GH-treated AN rats plus irbesartan [(27.3 +/- 5.1) pg/mg pro] were significantly higher than that in AN rats [(8.3 +/- 1.9) pg/mg pro] (P < 0.01). The protein expressions of TGF-beta(1), collagen IV and fibronectin in GH-treated AN rats were the most distinct in all groups. These expressions were significantly (P < 0.05) reduced in GH-treated AN rats plus irbesartan.

CONCLUSIONGH is able to exacerbate adriamycin-induced nephropathy in rats, which was partly through activating renal tissue RAS and initiating the function of the AngII-TGF beta(1)-ECM axis. Angiotensin II receptor antagonist, irbesartan, has some renal protective effects on AN rats treated with GH.

Angiotensin II ; analysis ; Angiotensin Receptor Antagonists ; Animals ; Antibiotics, Antineoplastic ; toxicity ; Biphenyl Compounds ; pharmacology ; therapeutic use ; Blood Urea Nitrogen ; Collagen Type IV ; analysis ; Creatinine ; blood ; Disease Models, Animal ; Doxorubicin ; toxicity ; Fibronectins ; analysis ; Growth Hormone ; pharmacology ; Immunohistochemistry ; Kidney Diseases ; chemically induced ; drug therapy ; Kidney Glomerulus ; chemistry ; drug effects ; pathology ; Male ; Peptidyl-Dipeptidase A ; analysis ; Proteinuria ; urine ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Serum Albumin ; metabolism ; Tetrazoles ; pharmacology ; therapeutic use ; Transforming Growth Factor beta ; analysis ; Triglycerides ; blood

OBJECTIVE: To compare the nephrotoxicity of high- and low-osmolar contrast media (HOCM and LOCM), and to determine the protective role of fosinopril or telmisartan and its possible mechanism. METHODS: Forty eight healthy SD rats were randomly divided into 6 groups: a normal control group, a glycerol control group, a low-osmolar contrast media (LOCM) group, a high-osmolar contrast media (HOCM) group, a fosinopril group, and a telmisartan group. Glycerine for inducing kidney damage was given to all rats except the normal control group. Twenty-four hours after the injection of glycerine, the mixed fosinopril suspension (10mg/kg) or telmisartan (5mg/kg) was poured into the stomach in the preventive group. Serum creatinine (SCr) and plasma angiotensin II (AngII) levels were detected by an automatical biochemical analyzer and radioimmunoassay; caspase-3 activity and claudin-1 expression of the renal tissue were detected by fluorometric method and immunohistochemical method. The renal injury was assessed by hematoxylin and eosin (HE) staining and terminal deoxynucleotide mediated nick and labeling (TUNEL) staining, respectively. RESULTS: In diatrizoate-injected rats, SCr and AngII levels were increased (P<0.05). Expression of claudin-1 protein and caspase-3 activity in the renal tissue was upregulated. The histologic changes and percentage of apoptotic cells were milder in the LOCM rats than those in the HOCM rats. In the group pretreated with fosinopril or telmisartan, no increase in the levels of SCr and AngII was discovered. The expression of claudin-1 protein and caspase-3 activity was significantly lower than that in the HOCM group. The renal injuries induced by diatrizoate were alleviated. CONCLUSION Both HOCM and LOCM could cause cellular apoptosis in the kidney.LOCM was less toxic to rat kidney than HOCM. Nephrotoxicity induced by HOCM might be related to caspase-3, claudin-1 and AngII. Fosinopril or telmisartan may protect the renal tissue from nephrotoxicity induced by diatrizoate.
Angiotensin II ; blood ; Animals ; Apoptosis ; drug effects ; Benzimidazoles ; pharmacology ; Benzoates ; pharmacology ; Caspase 3 ; metabolism ; Claudin-1 ; metabolism ; Contrast Media ; administration & dosage ; toxicity ; Creatinine ; blood ; Female ; Fosinopril ; pharmacology ; Kidney ; drug effects ; metabolism ; pathology ; Male ; Protective Agents ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Telmisartan