MicroRNAs (miRNAs) are noncoding RNAs that act as negative regulators of gene expression. Interestingly, specific alterations of miRNA expression have been found in failing hearts of different etiologies. The aim of this study was to identify the miRNA expression pattern of peripheral blood mononuclear cells (PBMCs) derived from chronic heart failure (CHF) patients affected by ischemic (ICM) and nonischemic dilated (NIDCM) cardiomyopathy. The expression profile of 257 miRNAs was assessed in 7 NIDCM patients, 8 ICM patients, and 9 control subjects by quantitative real-time PCR. Significantly modulated miRNAs were validated by using an independent set of 34 CHF patients (NIDCM = 19, ICM = 15) and 19 control subjects. Three miRNAs (miR-107, -139, and -142-5p) were downmodulated in both NIDCM and ICM patients versus control subjects. Other miRNAs were deregulated in only one of the CHF classes analyzed compared with control subjects: miR-142-3p and -29b were increased in NIDCM patients, while miR-125b and -497 were decreased in ICM patients. Bioinformatic analysis of miRNA predicted targets and of gene expression modifications associated with CHF in PBMCs indicated a significant impact of the miRNA signature on the transcriptome. Furthermore, miRNAs of both the NIDCM and the ICM signature shared predicted targets among CHF-modulated genes, suggesting potential additive or synergistic effects. The present study identified miRNAs specifically modulated in the PBMCs of NIDCM and ICM patients. Intriguingly, most of these miRNAs were previously reported as deregulated in human and/or mouse failing hearts. The identified miRNAs might have a potential diagnostic and/or prognostic use in CHF.
—Endothelial cells are exposed to an acidotic environment in a variety of pathological and physiological conditions. However, the effect of acidosis on endothelial cell function is still largely unknown, and it was evaluated in the present study. Bovine aortic endothelial cells (BAECs) were grown in bicarbonate buffer equilibrated either with 20% CO 2 (pH 7.0, acidosis) or 5% CO 2 (pH 7.4, control). Acidosis inhibited BAEC proliferation in 10% FCS, whereas by day 7 in serum-free medium, cell number was 3-fold higher in acidotic cells than in control cells. Serum deprivation enhanced BAEC apoptosis, and apoptotic cell death was markedly inhibited by acidosis. Additionally, acidosis inhibited FCS-stimulated migration in a modified Boyden chamber assay and FCS-stimulated differentiation into capillary-like structures on reconstituted basement membrane proteins. Conditioned media from BAECs cultured for 48 hours either at pH 7.0 or pH 7.4 enhanced BAEC proliferation and migration at pH 7.4, and both effects were more marked with conditioned medium from BAECs grown in acidotic than in control conditions. Acidosis enhanced vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) mRNA expression as well as bFGF secretion, and a blocking bFGF antibody inhibited enhanced BAEC migration in response to conditioned medium from acidotic cells. These results show that acidosis protects endothelial cells from apoptosis and inhibits their proangiogenic behavior despite enhanced VEGF and bFGF mRNA expression and bFGF secretion.
It has been previously shown that vascular endothelial growth factor (VEGF) plays a central role in promoting angiogenesis during wound repair and that healing-impaired diabetic mice show decreased VEGF expression levels. In order to investigate the potential benefits of gene therapy with growth factors on wound repair, a replication-deficient recombinant adenovirus vector carrying the human VEGF165 gene (AdCMV.VEGF165) was topically applied on excisional wounds of streptozotocin-induced diabetic mice. Treatment with AdCMV.VEGF165 significantly accelerated wound closure when compared with AdCMV.LacZ-treated, as well as saline-treated control mice, by promoting angiogenesis at the site of injury. Our findings suggest that AdCMV.VEGF165 may be regarded as a therapeutic tool for the treatment of diabetic ulcers.
HMGB1 injection into the mouse heart, acutely after myocardial infarction (MI), improves left ventricular (LV) function and prevents remodeling. Here, we examined the effect of HMGB1 in chronically failing hearts. Adult C57 BL16 female mice underwent coronary artery ligation; three weeks later 200 ng HMGB1 or denatured HMGB1 (control) were injected in the peri-infarcted region of mouse failing hearts. Four weeks after treatment, both echocardiography and hemodynamics demonstrated a significant improvement in LV function in HMGB1-treated mice. Further, HMGB1-treated mice exhibited a ∼23% reduction in LV volume, a ∼48% increase in infarcted wall thickness and a ∼14% reduction in collagen deposition. HMGB1 induced cardiac regeneration and, within the infarcted region, it was found a ∼2-fold increase in c-kit+ cell number, a ∼13-fold increase in newly formed myocytes and a ∼2-fold increase in arteriole length density. HMGB1 also enhanced MMP2 and MMP9 activity and decreased TIMP-3 levels. Importantly, miR-206 expression 3 days after HMGB1 treatment was 4-5-fold higher than in control hearts and 20–25 fold higher that in sham operated hearts. HMGB1 ability to increase miR-206 was confirmed in vitro, in cardiac fibroblasts. TIMP3 was identified as a potential miR-206 target by TargetScan prediction analysis; further, in cultured cardiac fibroblasts, miR-206 gain- and loss-of-function studies and luciferase reporter assays showed that TIMP3 is a direct target of miR-206. HMGB1 injected into chronically failing hearts enhanced LV function and attenuated LV remodelling; these effects were associated with cardiac regeneration, increased collagenolytic activity, miR-206 overexpression and miR-206 -mediated inhibition of TIMP-3.
Background —After endovascular injury, smooth muscle cells (SMCs) may be exposed to hemodynamic shear stress (SS), and these forces modulate neointima accumulation. The effect of SS on SMC migration and invasion is unknown, and it was examined in the present study. Methods and Results —Bovine aortic SMCs were exposed to laminar SS of 12 dyne/cm 2 for 3 (SS3) or 15 (SS15) hours; control (C3 and C15) SMCs were kept under static conditions. Platelet-derived growth factor (PDGF)-BB–directed SMC migration and invasion were evaluated by a modified Boyden chamber assay with filters coated with either gelatin or reconstituted basement membrane proteins (Matrigel), respectively. SS15 inhibited both SMC migration and invasion ( P <0.0001). There was no significant difference between SS3 and C3 cells. Media conditioned with SS15 cells exhibited a reduction in matrix metalloprotease-2 (MMP-2) by zymography and Western analysis. Northern blot analysis revealed no effect of SS15 on MMP-2 mRNA. In contrast, SS15 decreased MMP-2 activator and membrane-type MMP (MT-MMP or MMP-14) mRNA and protein. Furthermore, SS15 decreased PDGF receptor-β (PDGF-Rβ) mRNA and protein ( P <0.05), and the SS-dependent decrease in PDGF-BB–directed cell migration was rescued by overexpressing PDGF-Rβ. Conclusions —SS inhibits SMC migration and invasion via diminished PDGF-Rβ expression. This effect of SS is associated with decreased MMP-2 secretion and MT-MMP downregulation.
Desflurane in neurosurgery may be beneficial because it facilitates postoperative early neurologic evaluation. However, its use has been debated because of its capacity to promote cerebral vasodilatation. Sevoflurane has been extensively used in neurosurgical patients. In this prospective clinical trial, we compared early postoperative recovery and cognitive function in patients undergoing craniotomy for supratentorial expanding lesions and receiving sevoflurane or desflurane anesthesia. One hundred twenty patients, ASA physical status I-III (66 men), Glascow Coma Scale 15, undergoing craniotomy for supratentorial expanding lesions were enrolled in the study. Patients were randomly allocated to two anesthetic regimens. In Group S (60 patients, 52 +/- 16 yr), anesthesia was maintained using sevoflurane with end-tidal of 1.5%-2% and was age adjusted to obtain approximately 1.2 minimum alveolar anesthetic concentration. In Group D (60 patients, 60 +/- 14 yr), anesthesia was maintained using desflurane with end-tidal of 6%-7% and was age adjusted to obtain approximately 1.2 minimum alveolar concentration. Emergence time was measured as the time from drug discontinuation to the time at which patients opened their eyes; tracheal extubation time was measured as the time from anesthetic discontinuation and tracheal extubation. Recovery time was measured as the time elapsing from discontinuation of anesthetic and the time when patients were able to recall their name and date of birth. Cognitive behavior was evaluated with the Short Orientation Memory Concentration Test. In the postanesthesia care unit, a blinded observer monitored the patients for 3 h; the incidence of hemodynamic events, pain, nausea, and shivering requiring rescue medication was recorded. The mean emergence time (12.2 +/- 4.9 min in Group S vs 10.8 +/- 7.2 min in Group D; P = ns) was similar in the two groups, whereas the mean extubation time and recovery time were longer in Group S (15.2 +/- 3.0 min in Group S vs 11.3 +/- 3.9 min in Group D and 18.2 +/- 2.3 min in Group S vs 12.4 +/- 7.7 min in Group D, respectively; P < 0.001). The Short Orientation Memory Concentration Test score differed between the two groups only at the earliest assessment (15 min after extubation). No difference between the two groups was found in pain, shivering, nausea, vomiting, and incidence of postoperative hemodynamic events. Patients who received desflurane had a shorter extubation and recovery time but similar intraoperative and postoperative incidence of complications compared with those who received sevoflurane.