Rat calcineurin (CaN) A alpha isoform (Ppp3ca) cDNA recombinant adenovirus vector was constructed in order to explore the effect of CaN on the myocardium apoptosis induced by ischemia-reperfusion injury. Total RNA was isolated from the heart of the adult Wistar rat, and Ppp3ca CDS segment of approximate 1.59 kb size was amplified by reverse transcriptional PCR method. Ppp3ca cDNA segment was cloned into pMD18-T Simple vector for sequencing, and the right clone was named T-Ppp3ca. Ppp3ca cDNA segment obtained from T-Ppp3ca was ligated with pShuttle2-IRES-EGFP to construct a recombinant plasmid pShuttle2-Ppp3ca-IRES-EGFP. Ppp3ca-IRES-EGFP expression cassette containing CMV, Ppp3ca-IRES-EGFP and SV40 polyA DNA fragment (3.97 kb) obtained from pShuttle2-Ppp3ca-IRES-EGFP was connected with pAdeno-X backbone sequence to construct a recombinant plasmid pAdeno-Ppp3ca. After being identified by PCR and enzyme digestion, recombinant plasmid pAdeno-Ppp3ca was packaged in HEK293 cells. Supernatant of adenovirus from HEK293 cells was collected after a visible cytopathic effect (CPE) appeared. The DNA of the recombinant adenovirus was extracted with the standard method. The presence of the recombinant adenovirus was verified by PCR. The results showed that sequencing results verified that the PCR product of Ppp3ca gene was identical to GenBank. Agarose electrophoresis showed the bands of recombined plasmid pAdeno-Ppp3ca and the recombinant adenovirus identified by enzyme digestion and PCR were in the right range corresponding with expectation. It was concluded that the recombinant adenovirus carrying rat calcineurin A alpha (Ppp3ca) cDNA as well as a report gene-enhancer green fluorescent protein gene was successfully constructed in this experiment.
Adenoviridae/*genetics ; Calcineurin/*biosynthesis ; Calcineurin/genetics ; Cloning, Molecular ; DNA, Complementary/genetics ; Genetic Vectors/genetics ; Green Fluorescent Proteins/biosynthesis ; Green Fluorescent Proteins/genetics ; Myocardial Reperfusion Injury/*genetics ; Myocardium/chemistry ; Rats, Wistar ; Recombination, Genetic/genetics

The present study was to investigate the mRNA, protein expression and the activity of calcineurin in the hypertrophic heart, and to determine the effect of calcineurin inhibitor--cyclosporine A (CsA) on the regression of cardiac hypertrophy in renovascular hypertensive rats. Renovascular hypertension was induced by two kidney-one clip methods. Two months after the operation, cardiac hypertrophy was determined by histological analysis performed in some rats (2K1C-2M), then the rats were subdivided into 2 groups: (1) 3-month old two kidney-one clip group (2K1C-3M) with rats receiving 0.9% NaCl per day for one month, and (2) CsA-treated group with rats treated with CsA for one month. Sham-operated rats were used as control. The ratio of the left ventricular weight to tibial length (LVW/TL), the area of cardiac myocyte, mRNA and protein expression and the activity of calcineurin were determined. Both the LVW/TL and the cardiomyocyte area were significantly larger in 2K1C-2M and 2K1C-3M rats than in age-matched sham-operated rats. Treatment with CsA significantly attenuated the increase in the LVW/TL as well as the cardiomyocyte area. The mRNA, protein expression and the activity of calcineurin were significantly higher in 2K1C-2M and 2K1C-3M rats than those in the age-matched sham-operated rats, while the elevation of mRNA, protein expression and activity of calcineurin were significantly suppressed in the CsA-treated rats. In conclusion, calcineurin plays a role in the progression of cardiac hypertrophy in renovascular hypertensive rats. The inhibition of calcineurin can reverse cardiac hypertrophy.
Animals ; Calcineurin ; biosynthesis ; genetics ; metabolism ; Cyclosporine ; pharmacology ; Hypertension, Renovascular ; complications ; metabolism ; physiopathology ; Hypertrophy, Left Ventricular ; etiology ; metabolism ; physiopathology ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the role of calcineurin (CaN) in the lung fibroblast proliferation and collagen synthesis induced by basic fibroblast growth factor (bFGF).

METHODSWe used Western blot and immunohistochemical methods for investigating the content and distribution of calcineurin in the lung tissue. Calcineurin activity in different tissues was measured using (32)P-labelled substrate. In the primary culture of lung fibroblasts, (3)H-thymidine ((3)H-TdR) and (3)H-proline incorporation methods were used to study the effect of cyclosporin A (CsA), an inhibitor of calcineurin, on the lung fibroblast DNA and collagen synthesis stimulated by bFGF.

RESULTSWe found that calcineurin was expressed in lung tissue and has phosphatase activity (7.1 +/- 2.0 pmol Pi/mg pr/min). CsA (10(-8) - 10(-6) mol/L) inhibited lung fibroblast (3)H-TdR incorporation induced by bFGF in a dose-dependent manner, with the inhibitory rates by 20%, 46% and 66% (P < 0.01). CsA (10(-7) - 10(-6) mol/L) inhibited (3)H-proline incorporation in lung fibroblasts stimulated by bFGF, with the inhibitory rates by 21% and 37% (P < 0.01). In a culture medium, CsA (10(-8) - 10(-6) mol/L) inhibited (3)H-proline secretion induced by bFGF in a dose-dependent manner, with the inhibitory rates by 19%, 29% (P < 0.05) and 56% (P < 0.01). CsA (10(-7) mol/L) could inhibit calcineurin activity by 44% in lung fibroblasts (P < 0.01).

CONCLUSIONSCalcineurin is expressed in lung tissue and has phosphatase activity. It is involved in the bFGF stimulated lung fibroblast DNA and collagen synthesis.

Animals ; Calcineurin ; analysis ; physiology ; Cell Division ; Cell Survival ; drug effects ; Collagen ; biosynthesis ; Fibroblast Growth Factor 2 ; pharmacology ; Fibroblasts ; drug effects ; physiology ; Lung ; cytology ; drug effects ; metabolism ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo examine whether calcineurin/NFAT signaling pathway mediates endothelin-1 (ET-1)-induced proliferation of pulmonary artery smooth muscle cells (PASMCs) by regulating phosphodiesterase-5 (PDE5) and the effect of the selective calcineurin inhibitor cyclosporine A and PDE5 inhibitor sildenafil on ET-1-induced PASMC proliferation.

METHODSPASMCs were treated with ET-1 to stimulate their proliferation with or without prior treatment of the cells with CsA or sildenafil. Calcineurin activity in the cells was measured using a calcineurin activity assay kit, PDE5 expression examined using immunoblotting, and cGMP level detected using a cGMP direct immunoassay kit. PASMC proliferation following the treatments was determined using [(3)H]thymidine incorporation assay.

RESULTSET-1 caused a 2.05-fold increase in the cellular calcineurin activity, a 1.80-fold increase in PDE5 expression, and a 3.20-fold increase in the DNA synthesis rate, and reduced the cGMP level by 67%. Pretreatment of the cells with Cyclosporine blocked the effects of ET-1, and PDE5 inhibition by sildenafil pretreatment also abolished ET-1-induced reduction of cGMP level in the cells. Both Cyclosporine and sildenafil suppressed ET-1-stimulated PASMC proliferation.

CONCLUSIONActivation of calcineurin/NFAT signaling pathway mediates ET-1-induced PASMC proliferation by stimulating PDE5 expression, which further degrades cGMP. Both Cyclosporine and sildenafil can suppress ET-1-stimulated PASMC proliferation in vitro.

Animals ; Calcineurin ; metabolism ; Cell Proliferation ; drug effects ; Cells, Cultured ; Cyclic GMP ; metabolism ; Cyclic Nucleotide Phosphodiesterases, Type 5 ; metabolism ; Cyclosporine ; DNA ; biosynthesis ; Endothelin-1 ; pharmacology ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; cytology ; enzymology ; NFATC Transcription Factors ; metabolism ; Piperazines ; Pulmonary Artery ; cytology ; Purines ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Sildenafil Citrate ; Sulfones

AIMTo investigate the effects of cyclosporin A (CsA) on growth and collagen synthesis of cardiac fibroblasts (CFs) induced by arginine vasopressin (AVP).

METHODSCFs of neonatal Sprague-Dawley rats were isolated by trypsinization and cultured; growth-arrested CFs were stimulated with 1 x 10(-7) mol x L(-1) AVP in the presence or absence of CsA (0.05, 0.5 and 5 micromol x L(-1)). MTT and flow cytometry techniques were adopted to measure cell number and analyze cell cycle respectively. Collagen synthesis was determined by measurement of hydroxyproline content in culture supernatant with colorimetry. Calcineurin activity was estimated by chemiluminescence. Trypan blue staining to test the viability of CFs.

RESULTS0.05, 0.5 and 5 micromol x L(-1) CsA inhibited the increase of CFs number induced by 1 x 10(-7) mol x L(-1) AVP in a dose-dependent manner, with the inhibitory rates by 12%, 24% and 29%, respectively (P < 0.05). Furthermore, cell cycle analysis showed 0.5 micromol x L(-1) CsA decreased the S stage percentage and proliferation index of CFs stimulated by AVP (P < 0.05). In culture medium, the hydroxyproline content induced by AVP decreased by 0.5 and 5 micromol x L(-1) CsA (P < 0.05), with the inhibitory rates of 29% and 33%, respectively. CsA completely inhibited the increment of calcineurin activity induced by AVP (P < 0.01), but CsA itself had no effect on the baseline of calcineurin activity and CFs viability.

CONCLUSIONCsA inhibits proliferation and collagen synthesis of CFs by virtue of blocking calcineurin signaling pathway and might provide a novel target for prevention and treatment to cardiac fibrosis.

Animals ; Animals, Newborn ; Arginine Vasopressin ; pharmacology ; Calcineurin ; metabolism ; Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Cells, Cultured ; Collagen ; biosynthesis ; Cyclosporine ; administration & dosage ; pharmacology ; Dose-Response Relationship, Drug ; Fibroblasts ; cytology ; drug effects ; metabolism ; Hydroxyproline ; metabolism ; Myocardium ; cytology ; Rats ; Rats, Sprague-Dawley