Atypical Diabetic Foot Ulcer Keratinocyte Protein Signaling Correlates with Impaired Wound Healing.

Diabetes mellitus is associated with chronic diabetic foot ulcers (DFUs) and wound infections often resulting in lower extremity amputations. The protein signaling architecture of the mechanisms responsible for impaired DFU healing has not been characterized. In this preliminary clinical study, the intracellular levels of proteins involved in signal transduction networks relevant to wound healing were non-biasedly measured using reverse-phase protein arrays (RPPA) in keratinocytes isolated from DFU wound biopsies.

Hydrogen sulfide mediates the cardioprotective effects of gene therapy with PKG-Iα.

Cyclic GMP-dependent protein kinase (PKG) is a serine-threonine kinase that mediates the cardioprotective effect of ischemic and pharmacologic preconditioning. Since hydrogen sulfide (H2S) has been implicated in mediating the cardioprotective effects of the cGMP modulators tadalafil and cinaciguat, we tested the hypothesis that myocardial gene therapy with PKG exerts cardioprotection against ischemia/reperfusion (I/R) injury through a mechanism involving H2S. Adult rat cardiomyocytes were infected with adenoviral vector encoding PKGIα or inactive mutant PKGIαK390A (K390A) for 24 h.

Beetroot juice reduces infarct size and improves cardiac function following ischemia-reperfusion injury: Possible involvement of endogenous H2S.

Ingestion of high dietary nitrate in the form of beetroot juice (BRJ) has been shown to exert antihypertensive effects in humans through increasing cyclic guanosine monophosphate (cGMP) levels. Since enhanced cGMP protects against myocardial ischemia-reperfusion (I/R) injury through upregulation of hydrogen sulfide (H2S), we tested the hypothesis that BRJ protects against I/R injury via H2S. Adult male CD-1 mice received either regular drinking water or those dissolved with BRJ powder (10 g/L, containing ∼ 0.

Tadalafil prevents acute heart failure with reduced ejection fraction in mice.

Purpose: Phosphodiesterase-5 (PDE5) inhibitors were shown to exert powerful protection in various animal models of cardiomyopathy. Tadalafil is a long-acting and highly specific PDE5 inhibitor, which makes it the most attractive in its class for long-term management of patients with heart failure. We studied the effects of tadalafil in attenuating ischemic cardiomyopathy in mice.

Anti-inflammatory and cardioprotective effects of tadalafil in diabetic mice.

Background: Insulin resistance impairs nitric oxide (NO) bioavailability and obesity promotes a state of chronic inflammation and damages the vascular endothelium. Phosphodiesterase-5 inhibitors restore NO signaling and may reduce circulating inflammatory markers, and improve metabolic parameters through a number of mechanisms. We hypothesized that daily administration of the PDE-5 inhibitor, tadalafil (TAD) will attenuate inflammation, improve fasting plasma glucose and triglyceride levels, body weight, and reduce infarct size after ischemia/reperfusion injury in obese, diabetic mice.

Cinaciguat, a novel activator of soluble guanylate cyclase, protects against ischemia/reperfusion injury: role of hydrogen sulfide.

Cinaciguat (BAY 58-2667) is a novel nitric oxide (NO)-independent activator of soluble guanylate cyclase (sGC), which induces cGMP-generation and vasodilation in diseased vessels. We tested the hypothesis that cinaciguat might trigger protection against ischemia/reperfusion (I/R) in the heart and adult cardiomyocytes through cGMP/protein kinase G (PKG)-dependent generation of hydrogen sulfide (H(2)S). Adult New Zealand White rabbits were pretreated with 1 or 10 μg/kg cinaciguat (iv) or 10% DMSO (vehicle) 15 min before I/R or with 10 μg/kg cinaciguat (iv) at reperfusion.

Preconditioning by phosphodiesterase-5 inhibition improves therapeutic efficacy of adipose-derived stem cells following myocardial infarction in mice.

The rationale of this article is enhancing the therapeutic potential of stem cells in ischemic microenvironments by novel preconditioning strategies is critical for improving cellular therapy. We tested the hypothesis that inhibition of phosphodiesterase-5 (PDE-5) with sildenafil (Viagra) or knockdown with a silencing vector in adipose-derived stem cells (ASCs) would improve their survival and enhance cardiac function following myocardial implantation in vivo. ASCs were treated with sildenafil or PDE-5 silencing vector short hairpin RNA (shRNA(PDE-5)) and subjected to simulated ischemia/reoxygenation in vitro.

Left ventricular systolic dysfunction induced by ventricular ectopy: a novel model for premature ventricular contraction-induced cardiomyopathy.

Background: Premature ventricular contractions (PVCs) commonly coexist with cardiomyopathy. Recently, PVCs have been identified as a possible cause of cardiomyopathy. We developed a PVC-induced cardiomyopathy animal model using a novel premature pacing algorithm to assess timeframe and reversibility of this cardiomyopathy and examine the associated histopathologic abnormalities.

Mitigation of the progression of heart failure with sildenafil involves inhibition of RhoA/Rho-kinase pathway.

Chronic inhibition of phosphodiesterase-5 with sildenafil immediately after permanent occlusion of the left anterior descending coronary artery was shown to limit ischemic heart failure (HF) in mice. To mimic a more clinical scenario, we postulated that treatment with sildenafil beginning at 3 days post-myocardial infarction (MI) would also reduce HF progression through the inhibition of the RhoA/Rho-kinase pathway. Adult male ICR mice with fractional shortening < 25% at day 3 following permanent left anterior descending coronary artery ligation were continuously treated with either saline (volume matched, ip, 2 times/day) or sildenafil (21 mg/kg, ip, 2 times/day) for 25 days.

Sildenafil increases chemotherapeutic efficacy of doxorubicin in prostate cancer and ameliorates cardiac dysfunction.

We have shown that the potent phosphodiesterase-5 (PDE-5) inhibitor sildenafil (Viagra) induces a powerful effect on reduction of infarct size following ischemia/reperfusion injury and improvement of left ventricular dysfunction in the failing heart after myocardial infarction or doxorubicin (DOX) treatment. In the present study, we further investigated the potential effects of sildenafil on improving antitumor efficacy of DOX in prostate cancer. Cotreatment with sildenafil enhanced DOX-induced apoptosis in PC-3 and DU145 prostate cancer cells, which was mediated by enhanced generation of reactive oxygen species, up-regulation of caspase-3 and caspase-9 activities, reduced expression of Bcl-xL, and phosphorylation of Bad.

Adrenergic receptor blockade reverses right heart remodeling and dysfunction in pulmonary hypertensive rats.

Rationale: Most patients with pulmonary arterial hypertension (PAH) die from right heart failure. Beta-adrenergic receptor blockade reduces mortality by about 30% in patients with left-sided systolic heart failure, but is not used in PAH.

Objectives: To assess the effect of the adrenergic receptor blocker carvedilol on the pulmonary circulation and right heart in experimental pulmonary hypertension in rats.

Pharmacologic inhibition of myeloid differentiation factor 88 (MyD88) prevents left ventricular dilation and hypertrophy after experimental acute myocardial infarction in the mouse.

Background: Myeloid differentiation factor 88 (MyD88) is an endogenous adaptor protein that coordinates the inflammatory response to agonists of the Toll-like receptor and interleukin-1 receptor families. This particular response is activated following myocardial ischemia and infarction and may represent a viable target for pharmacologic inhibition. The current study tested MyD88 inhibitors in a murine model of nonreperfused acute myocardial infarction (AMI).

Interleukin-1 trap attenuates cardiac remodeling after experimental acute myocardial infarction in mice.

Background: Interleukin-1 (IL-1) is an inflammatory cytokine that responds as an acute phase reactant during acute myocardial infarction. Conflicting data describe the role of anti-IL-1 interventions to reduce cardiac remodeling after AMI. IL-1 Trap is a modified recombinant fusion protein that binds circulating IL-1.

Phosphodiesterase-5 inhibitor, tadalafil, protects against myocardial ischemia/reperfusion through protein-kinase g-dependent generation of hydrogen sulfide.

Background: Tadalafil is a novel long-acting inhibitor of phosphodiesterase-5. Because cGMP-dependent protein kinase (PKG) signaling plays a key role in cardioprotection, we hypothesized that PKG activation with tadalafil would limit myocardial ischemia/reperfusion (I/R) injury and dysfunction. Additionally, we contemplated that cardioprotection with tadalafil is mediated by hydrogen sulfide (H(2)S) signaling in a PKG-dependent fashion.

Apoptosis in patients with acute myocarditis.

Acute myocarditis is an acute inflammatory syndrome characterized by acute myocardial damage and dysfunction followed by a variable recovery over time with some patients progressing toward severe dilated cardiomyopathy. Cardiomyocyte apoptosis, a key pathologic feature of heart failure, may play a critical role in functional recovery in patients with acute myocarditis. The aim of the study was to investigate whether apoptosis predicts functional recovery in patients with acute myocarditis.

Parecoxib inhibits apoptosis in acute myocardial infarction due to permanent coronary ligation but not due to ischemia-reperfusion.

Purpose: Myocardial ischemia induces cyclooxygenase 2 (COX-2) expression. We evaluated the effects of parecoxib, a COX-2 inhibitor, in 2 different mouse models of myocardial ischemia: permanent left coronary artery ligation (PI) and transient ligation (30 minutes ischemia) followed by reperfusion (I/R).

Methods: Forty adult male Institute of Cancer Research mice underwent PI (n = 24) or I/R (n = 16), followed by randomization to parecoxib (0.

Anakinra in experimental acute myocardial infarction--does dosage or duration of treatment matter?

Purpose: Interleukin-1 (IL-1) receptor antagonist (Ra) is a naturally occurring IL-1 blocker with a cardioprotective effect during acute myocardial infarction (AMI). Anakinra, recombinant-human IL-1Ra, has been used to prevent heart failure in a mouse model of AMI. The aim of this study was to determine the optimal therapeutic regimen for anakinra in AMI.

Anakinra, a recombinant human interleukin-1 receptor antagonist, inhibits apoptosis in experimental acute myocardial infarction.

Background: Experimental interleukin-1 receptor antagonist gene overexpression has shown that interleukin-1 receptor antagonist is cardioprotective during global cardiac ischemia. The aim of the present study was to test the impact of an exogenous recombinant human interleukin-1 receptor antagonist (anakinra) in experimental acute myocardial infarction.

Methods And Results: Two animal studies were conducted: one of immediate anakinra administration during ischemia in the mouse and one of delayed anakinra administration 24 hours after ischemia in the rat.

Sildenafil (Viagra) attenuates ischemic cardiomyopathy and improves left ventricular function in mice.

We tested the hypothesis that chronic treatment with sildenafil attenuates myocardial infarction (MI)-induced heart failure. Sildenafil has potent protective effects against necrosis and apoptosis following ischemia-reperfusion in the intact heart and cardiomyocytes. ICR mice underwent MI by left anterior descending coronary artery ligation and were treated with sildenafil (0.