Dapa attenuated the activation of the inflammasome, fibrosis, and deterioration of LVEF in BTBR mice. The anti-inflammatory, anti-fibrotic effects are likely SGLT2- and glucose-lowering-independent, as they were replicated in the in vitro model. The effects on remodeling were augmented when Saxa was added to Dapa. Yet, adding Saxa to Dapa did not result in a greater effect on myocardial fibrosis and collagen levels.

MicroRNAs (miRNAs) are small (∼22 nt) noncoding single-stranded RNA molecules that downregulate gene expression. Studies have shown that miRNAs control diverse aspects of heart disease, including hypertrophy, remodeling, heart failure, and arrhythmia. Recently, several studies have suggested that miRNAs contribute to ischemia-reperfusion injury by altering key signaling elements, thus making them potential therapeutic targets. By altering the expression of various key elements in cell survival and apoptosis [such as phosphoinositide 3-kinase (PI3K), phosphatase and tensin homolog deleted on chromosome 10 (PTEN), Bcl-2, Mcl-1, heat shock protein (HSP)60, HSP70, HSP20, programmed cell death 4 (Pdcd4), LRRFIP1, Fas ligand (FasL), Sirt-1, etc.], miRNAs alter the response to ischemia-reperfusion injury. Studies using various in vivo, ex vivo, and in vitro models have suggested the possible involvement of miR-1, miR-21, miR-29, miR-92a, miR-133, miR-199a, and miR-320 in ischemia-reperfusion injury and/or remodeling after myocardial infarction. Thus miRNAs could be potential therapeutic targets for the treatment of heart disease. Inhibiting miRNAs by antisense strategies or pharmacological approaches is likely to emerge as an alternative and safe method for conferring short- and intermediate-term protection against ischemia-reperfusion injury.

The brains of Alzheimer's disease (AD) patients display cerebrovascular and parenchymal deposits of beta-amyloid (A beta) peptides, which are derived by proteolytic processing by the beta-site APP-cleaving enzyme 1 (BACE1) of the amyloid precursor protein (APP). The rat BACE1 promoter has a nuclear factor-kappaB (NF-kappaB) binding site. Deletion studies with a BACE1 promoter/luciferase reporter suggest that the NF-kappaB binding DNA consensus sequence plays a suppressor role, when occupied by NF-kappaB, in the regulation of neuronal brain BACE1 expression. Here we characterize a signal transduction pathway that may be responsible for the increases in A beta associated with AD. We propose that the transcription factor NF-kappaB acts as a repressor in neurons but as an activator of BACE1 transcription in activated astrocytes present in the CNS under chronic stress, a feature present in the AD brain. The activated astrocytic stimulation of BACE1 may in part account for increased BACE1 transcription and subsequent processing of Ab eta in a cell-specific manner in the aged and AD brain. As measured by reporter gene promoter constructs and endogenous BACE1 protein expression, a functional NF-kappaB site was stimulatory in activated astrocytes and A beta-exposed neuronal cells and repressive in neuronal and nonactivated astrocytic cells. Given the evidence for increased levels of activated astrocytes in the aged brain, the age- and AD-associated increases in NF-kappaB in brain may be significant contributors to increases in A beta, acting as a positive feedback loop of chronic inflammation, astrocyte activation, increased p65/p50 activation of BACE1 transcription, and further inflammation.

We determined the effects of cyclooxygenase-1 (COX-1; SC-560), COX-2 (SC-58125), and inducible nitric oxide synthase (iNOS; 1400W) inhibitors on atorvastatin (ATV)-induced myocardial protection and whether iNOS mediates the ATV-induced increases in COX-2. Sprague-Dawley rats received 10 mg ATV.kg(-1).day(-1) added to drinking water or water alone for 3 days and received intravenous SC-58125, SC-560, 1400W, or vehicle alone. Anesthesia was induced with ketamine and xylazine and maintained with isoflurane. Fifteen minutes after intravenous injection rats underwent 30-min myocardial ischemia followed by 4-h reperfusion [infarct size (IS) protocol], or the hearts were explanted for biochemical analysis and immunoblotting. Left ventricular weight and area at risk (AR) were comparable among groups. ATV reduced IS to 12.7% (SD 3.1) of AR, a reduction of 64% vs. 35.1% (SD 7.6) in the sham-treated group (P < 0.001). SC-58125 and 1400W attenuated the protective effect without affecting IS in the non-ATV-treated rats. ATV increased calcium-independent NOS (iNOS) [11.9 (SD 0.8) vs. 3.9 (SD 0.1) x 1,000 counts/min; P < 0.001] and COX-2 [46.7 (SD 1.1) vs. 6.5 (SD 1.4) pg/ml of 6-keto-PGF(1alpha); P < 0.001] activity. Both SC-58125 and 1400W attenuated this increase. SC-58125 did not affect iNOS activity, whereas 1400W blocked iNOS activity. COX-2 was S-nitrosylated in ATV-treated but not sham-treated rats or rats pretreated with 1400W. COX-2 immunoprecipitated with iNOS but not with endothelial nitric oxide synthase. We conclude that ATV reduced IS by increasing the activity of iNOS and COX-2, iNOS is upstream to COX-2, and iNOS activates COX-2 by S-nitrosylation. These results are consistent with the hypothesis that preconditioning effects are mediated via PG.

Central neuropathic pain (CNP) is an important problem following spinal cord injury (SCI), because it severely affects the quality of life of SCI patients. As in the patient population, the majority of rats develop significant allodynia (CNP rats) after moderate SCI. However, about 10% of SCI rats do not develop allodynia, or develop significantly less allodynia than CNP rats (non-CNP rats). To identify transcriptional changes underlying CNP development after SCI, we used Affymetrix DNA microarrays and RNAs extracted from the spinal cords of CNP and non-CNP rats. DNA microarry analysis showed significantly increased expression of a number of genes associated with inflammation and astrocytic activation in the spinal cords of rats that developed CNP. For example, mRNA levels of glial fibrilary acidic protein (GFAP) and Aquaporin 4 (AQP4) significantly increased in CNP rats. We also found that GFAP, S100b and AQP4 protein elevation persisted for at least 9 months throughout contused spinal cords, consistent with the chronic nature of CNP. Thus, we hypothesize that CNP development results, in part, from dysfunctional, chronically ''over-activated'' astrocytes. Although, it has been shown that activated astrocytes are associated with peripheral neuropathic pain, this has not previously been demonstrated in CNP after SCI.

The effect of spinal cord injury (SCI) on the expression levels and distribution of water channel aquaporin 4 (AQP4) has not been studied. We have found AQP4 in gray and white matter astrocytes in both uninjured and injured rat spinal cords. AQP4 was detected in astrocytic processes that were tightly surrounding neurons and blood vessels, but more robustly in glia limitans externa and interna, which were forming an interface between spinal cord parenchyma and cerebrospinal fluid (CSF). Such spatial distribution of AQP4 suggests a critical role that astrocytes expressing AQP4 play in the transport of water from blood/CSF to spinal cord parenchyma and vice versa. SCI induced biphasic changes in astrocytic AQP4 levels, including its early down-regulation and subsequent persistent up-regulation. However, changes in AQP4 expression did not correlate well with the onset and magnitude of astrocytic activation, when measured as changes in GFAP expression levels. It appears that reactive astrocytes began expressing increased levels of AQP4 after migrating to the wound area (thoracic region) two weeks after SCI, and AQP4 remained significantly elevated for months after SCI. We also showed that increased levels of AQP4 spread away from the lesion site to cervical and lumbar segments, but only in chronically injured spinal cords. Although overall AQP4 expression levels increased in chronically-injured spinal cords, AQP4 immunolabeling in astrocytic processes forming glia limitans externa was decreased, which may indicate impaired water transport through glia limitans externa. Finally, we also showed that SCI-induced changes in AQP4 protein levels correlate, both temporally and spatially, with persistent increases in water content in acutely and chronically injured spinal cords. Although correlative, this finding suggests a possible link between AQP4 and impaired water transport/edema/syringomyelia in contused spinal cords.

Background-Both statins and thiazolidinediones have antiinflammatory properties. However, the exact mechanisms underlying these effects are unknown. We investigated whether atorvastatin (ATV) and pioglitazone (PIO) increase the myocardial content of lipoxin-A 4 and 15(R)-epi-lipoxin-A 4 (15-epi-LXA 4 ), both arachidonic acid products with strong antiinflammatory properties. Methods and Results-In experiment 1, rats received 3-day pretreatment with water; PIO 2, 5, or 10 mg · kg Ϫ1 · d Ϫ1 ; ATV 2, 5, or 10 mg · kg Ϫ1 · d

Downregulation of miR-29 protected hearts against IR injury. The modulation of miRNAs can be achieved by pharmacological intervention. These findings provide a rationale for the development of miRNA-based strategies for the attenuation of IR injury.