BACKGROUND: Chronic kidney disease (CKD) is associated with common pathophysiological processes, such as inflammation and fibrosis, in both the heart and the kidney. However, the underlying molecular mechanisms that drive these processes are not yet fully understood. Therefore, this study focused on the molecular mechanism of heart and kidney injury in CKD. METHODS: We generated an microRNA (miR)-26a knockout (KO) mouse model to investigate the role of miR-26a in angiotensin (Ang)-II-induced cardiac and renal injury. We performed Ang-II modeling in wild type (WT) mice and miR-26a KO mice, with six mice in each group. In addition, Ang-II-treated AC16 cells and HK2 cells were used as in vitro models of cardiac and renal injury in the context of CKD. Histological staining, immunohistochemistry, quantitative real-time polymerase chain reaction (PCR), and Western blotting were applied to study the regulation of miR-26a on Ang-II-induced cardiac and renal injury. Immunofluorescence reporter assays were used to detect downstream genes of miR-26a, and immunoprecipitation was employed to identify the interacting protein of LIM and senescent cell antigen-like domain 1 (LIMS1). We also used an adeno-associated virus (AAV) to supplement LIMS1 and explored the specific regulatory mechanism of miR-26a on Ang-II-induced cardiac and renal injury. Dunnett's multiple comparison and t -test were used to analyze the data. RESULTS: Compared with the control mice, miR-26a expression was significantly downregulated in both the kidney and the heart after Ang-II infusion. Our study identified LIMS1 as a novel target gene of miR-26a in both heart and kidney tissues. Downregulation of miR-26a activated the LIMS1/integrin-linked kinase (ILK) signaling pathway in the heart and kidney, which represents a common molecular mechanism underlying inflammation and fibrosis in heart and kidney tissues during CKD. Furthermore, knockout of miR-26a worsened inflammation and fibrosis in the heart and kidney by inhibiting the LIMS1/ILK signaling pathway; on the contrary, supplementation with exogenous miR-26a reversed all these changes. CONCLUSIONS Our findings suggest that miR-26a could be a promising therapeutic target for the treatment of cardiorenal injury in CKD. This is attributed to its ability to regulate the LIMS1/ILK signaling pathway, which represents a common molecular mechanism in both heart and kidney tissues.
Animals ; MicroRNAs/metabolism* ; Angiotensin II/toxicity* ; Mice ; Renal Insufficiency, Chronic/chemically induced* ; Mice, Knockout ; Disease Models, Animal ; Male ; Signal Transduction/genetics* ; LIM Domain Proteins/genetics* ; Mice, Inbred C57BL ; Cell Line ; Humans

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

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

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

NAD(P)H oxidase plays an important role in hypertension and its complication in aldosterone-salt rat. We questioned whether NAD(P)H oxidase subunit expression and activity are modulated by aldosterone and whether this is associated with target- organ damage. Rats were infused with aldosterone (0.75 microgram/hr/day) for 6 weeks and were given 0.9% NaCl+/-losartan (30 mg/kg/day), spironolactone (200 mg/kg/ day), and apocynin (1.5 mM/L). Aldosterone-salt hypertension was prevented completely by spironolactone and modestly by losartan and apocynin. Aldosterone increased aortic NAD(P)H oxidase activity by 34% and spironolactone and losartan inhibited the activity. Aortic expression of the subunits p47(phox), gp91(phox), and p22(phox) increased in aldosterone-infused rats by 5.5, 4.7, and 3.2-fold, respectively, which was decreased completely by spironolactone and partially by losartan and apocynin. Therefore, the increased expression of NAD(P)H oxidase may contribute to cardiovascular damage in aldosterone-salt hypertension through the increased expression of each subunit.
Acetophenones/administration & dosage ; Aldosterone/administration & dosage/*toxicity ; Aldosterone Antagonists/administration & dosage ; Angiotensin II Type 1 Receptor Blockers/administration & dosage ; Animals ; Anti-Inflammatory Agents, Non-Steroidal/administration & dosage ; Aorta/metabolism/pathology ; Blood Pressure/drug effects ; Hypertension/chemically induced/drug therapy/*enzymology ; Kidney/metabolism/pathology ; Losartan/administration & dosage ; Male ; NADPH Oxidase/antagonists & inhibitors/*metabolism ; Organ Size ; Oxidative Stress ; Protein Subunits/metabolism ; RNA, Messenger/metabolism ; Rats ; Rats, Sprague-Dawley ; Sodium Chloride/administration & dosage ; Spironolactone/administration & dosage ; Superoxides/metabolism

OBJECTIVETo observe effects of tetrandrine (Tet) on angiotensin II (Ang II)-induced cardiomyocyte hypertrophy and the activity and expression of phosphorylated ERK1/2 (p-ERK1/2).

METHODIn the primary culture of neonatal rat cardiomyocytes, as indexes of cardiomyocyte hypertrophy, pulsation rate was measured under phase contrast microscope. Cell size was determined by cell morphology analytical system. The total protein was determined by coomassie brilliant blue and protein synthesis rate was measured by [3H]-Leucine incorporation. ERK activity was measured by immuno-precipitation. The expression of p-ERK1/2 was assessed using Western blot.

RESULTTet can decrease Ang II-induced elevations of the pulsation rate, cell size, total protein and protein synthesis rate; inhibit the activity and expression of p-ERK1/2.

CONCLUSIONThe anti-hypertrophic effect of Tet on Ang II-induced cardiomyocyte hypertrophy was associated with inhibition of ERK1/2 signaling pathway.

Angiotensin II ; toxicity ; Animals ; Animals, Newborn ; Benzylisoquinolines ; isolation & purification ; pharmacology ; Blotting, Western ; Cell Size ; drug effects ; Cells, Cultured ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Hypertrophy ; Immunoprecipitation ; Microscopy, Phase-Contrast ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Myocytes, Cardiac ; drug effects ; metabolism ; pathology ; Phosphorylation ; drug effects ; Plants, Medicinal ; chemistry ; Protein Biosynthesis ; drug effects ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Stephania tetrandra ; chemistry

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

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

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