Upregulation of peroxisome proliferator-activated receptor-gamma and NADPH oxidases are involved in restenosis after balloon injury

The role of microglia in neuroprogressive disorders: mechanisms and possible neurotherapeutic effects of induced ketosis

A comprehensive review of molecular mechanisms involved in the promotion and maintenance of distinct microglia phenotypes is provided. The acquisition and perpetuation of predominantly pro-inflammatory microglial phenotypes have been implicated in the pathophysiology of several neuroprogressive diseases and is associated with reduced ATP production via oxidative phosphorylation, increased ATP generation by glycolysis, elevated oxidative and nitrosative stress and other metabolic, inflammatory and hormonal insults. Microglia can also adopt a predominantly anti-inflammatory phenotypes with neuroprotective properties. Strategies that promote and maintain a predominantly anti-inflammatory phenotype may hold promise as novel therapeutic opportunities for neuroprogressive illness. Induced ketosis may promote a transition towards predominantly anti-inflammatory microglial states/phenotypes by several mechanisms, including inhibition of glycolysis and increased NAD⁺ production; engagement of microglial GPR109A receptors; histone deacetylase inhibition; and elevated n-3 polyunsaturated fatty acids levels. Since microglia activation can now be assessed in vivo, these data provide a clear rationale for the design of transdiagnostic randomized controlled trials of the ketogenic diet and other ketosis-inducing strategies for neuroprogressive diseases, which may also provide mechanistic insights through the assessment of "target engagement".

Data in support of alpha1beta1 and integrin-linked kinase interact and modulate angiotensin II effects in vascular smooth muscle cells

The data provides information in support of the research article Moraes et al., Atherosclerosis 243(2) (2015) 477–485 [1]. Here we provide data behind the mechanisms involved in Angiotensin II (Ang II) effects on vascular smooth muscle cells (VSMC). Ang II-induced VSMC ROS production is modulated by alpha1beta1 integrin. Ang II also stimulates ROS production in VSMC via p47^phox, a NOX2 subunit. Furthermore, Ang II effect on VSMC migration was also inhibited by NOX2 inhibitor. We showed that obtustatin, alpha1beta1 integrin blocker, inhibited Ang II effect on p47^phox activation. Ang II effect on ROS production is also PI3K dependent. Finally we showed that NOX1 and Integrin-Linked-Kinase (ILK) are crucial to NOX2 activation. The research provides information about the sequential events of NOX1/alpha1beta1 integrin/ILK/NOX2 in Ang II effects on VSMC.

Alpha1beta1 and integrin-linked kinase interact and modulate angiotensin II effects in vascular smooth muscle cells

The effects of angiotensin II (Ang II) on vascular smooth muscle cells (VSMC) are modulated by reactive oxygen species (ROS) and also involve integrin engagement. However, the potential link between alpha1beta1 integrin signaling with NOX system and their combined contribution to Ang II effects on VSMC have not been investigated. We aimed to elucidate the moslecular mechanisms underlying the activation of these two pathways in Ang II effects on VSMC. Ang II-induced VSMC migration (2-fold increase) and proliferation (2.5-fold increase) is modulated by alpha1beta1 integrin, being inhibited by obtustatin, a specific alpha1beta1 integrin blocker. Ang II also stimulates ROS production in VSMC (140%) that is NOX1 dependent, being completely inhibited in NOX1 silenced cells. The ROS production develops in two peaks, and the second peak is maintained by NOX2 activation. Apocynin and obtustatin inhibit the NOX2-associated second peak, but not the first peak of ROS production, which is related to NOX1 activation. Corroborating the involvement of alpha1beta1 integrin, the pretreatment of VSMC with obtustatin impaired Ang II-induced FAK phosphorylation, AKT activation, p21 degradation and the increase of ILK expression. Silencing of ILK blocked cell migration, AKT phosphorylation and the second peak of ROS, but partially inhibits (70%) VSMC proliferation induced by Ang II. The data demonstrate a novel role for NOX2 in Ang II effects on VSMC, and suggest alpha1beta1 integrin and ILK as target molecules to the development of more effective therapeutic interventions in cardiovascular diseases.

Rosiglitzone suppresses angiotensin II-induced production of KLF5 and cell proliferation in rat vascular smooth muscle cells

Krüppel-like factor (KLF) 5, which initiates vascular smooth muscle cell (VSMC) proliferation, also participates in Angiotensin (Ang) II-induced vascular remodeling. The protective effect of rosiglitazone on vascular remodeling may be due to their impact on VSMC proliferation. However, the underlying mechanisms involved remain unclear. This study was designed to investigate whether the antiproliferation effects of rosiglitazone are mediated by regulating Ang II/KLF5 response. We found that, in aortas of Ang II-infused rats, vascular remodeling and KLF5 expression were markedly increased, and its target gene cyclin D1 was overexpressed. Co-treatment with rosiglitazone diminished these changes. In growth-arrested VSMCs, PPAR-γ agonists (rosiglitazone and 15d-PGJ2) dose-dependently inhibited Ang II-induced cell proliferation and expression of KLF5 and cyclin D1. Moreover, these effects were attenuated by the PPAR-γ antagonists GW9662, bisphenol A diglycidyl ether and PPAR-γ specific siRNA. Furthermore, rosiglitazone inhibited Ang II-induced phosphorylation of protein kinase C (PKC) ζ and extracellular signal-regulated kinase (ERK) 1/2 and activation of early growth response protein (Egr). In conclusion, in Ang II-stimulated VSMCs, rosiglitazone might have an antiproliferative effect through mechanisms that include reducing KLF5 expression, and a crosstalk between PPAR-γ and PKCζ/ERK_1/2/Egr may be involved in. These findings not only provide a previously unrecognized mechanism by which PPAR-γ agonists inhibit VSMC proliferation, but also document a novel evidence for the beneficial vascular effect of PPAR-γ activation.

Minireview: Won't get fooled again: the nonmetabolic roles of peroxisome proliferator-activated receptors (PPARs) in the heart

The peroxisome proliferator-activated receptor (PPAR) transcription factors are nuclear receptors initially identified for their key role in regulating metabolic processes. Recent studies designed to identify the role of PPARalpha, -beta, and -gamma in vivo uncovered extrametabolic roles that may be less well known in the heart. In this review, we describe what is known about these extrametabolic roles of PPARs, including regulation of cardiac inflammation, extracellular matrix remodeling, oxidative stress, and regulation of cardiac hypertrophy. Lastly, we discuss the emerging role of PPARs in cell cycle regulation and angiogenesis in noncardiac systems that may be applicable to heart biology. Although this review primarily discusses the extrametabolic role of PPARalpha, the most studied PPAR isoform in the heart, we highlight where possible what is known about the unique and overlapping roles of the PPAR isoforms in terms of metabolic function.