Antioxidant and Anti-atherogenic Properties of Prosopis strombulifera and Tessaria absinthioides Aqueous Extracts: Modulation of NADPH Oxidase-Derived Reactive Oxygen Species

Despite popular usage of medicinal plants, their effects as cardiovascular protective agents have not been totally elucidated. We hypothesized that treatment with aqueous extract from Prosopis strombulifera (AEPs) and Tessaria absinthioides (AETa), Argentinian native plants, produces antioxidant effects on vascular smooth muscle cells (VSMCs) and attenuates atherogenesis on apolipoprotein E-knockout (ApoE-KO) mice. In VSMCs, both extracts (5–40 μg/ml) inhibited 10% fetal calf serum-induced cell proliferation, arrested cell in G2/M phase, reduced angiotensin II-induced reactive oxygen species (ROS) generation, and decreased NADPH oxidase subunit expression. In ApoE-KO mice, extracts significantly reduced triglycerides and lipid peroxidation [plasma thiobarbituric acid reactive substances (TBARS)], increased plasma total antioxidant status (TAS), and improved glutathione peroxidase activity in the liver. Under high-fat diet (HFD), both extracts were able to inhibit O₂^– generation in the aortic tissue and caused a significant regression of atheroma plaques (21.4 ± 1.6% HFD group vs. 10.2 ± 1.2%^∗ AEPs group and 14.3 ± 1.0%^∗ AETa group; ^∗p < 0.01). Consumption of AEPs and AETa produces antioxidant/antimitogenic/anti-atherosclerotic effects, and their use may be beneficial as a complementary strategy regarding cardiovascular disease therapies.

Mitochondria form contact sites with the nucleus to couple prosurvival retrograde response

Mitochondria drive cellular adaptation to stress by retro-communicating with the nucleus. This process is known as mitochondrial retrograde response (MRR) and is induced by mitochondrial dysfunction. MRR results in the nuclear stabilization of prosurvival transcription factors such as the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). Here, we demonstrate that MRR is facilitated by contact sites between mitochondria and the nucleus. The translocator protein (TSPO) by preventing the mitophagy-mediated segregation o mitochonria is required for this interaction. The complex formed by TSPO with the protein kinase A (PKA), via the A-kinase anchoring protein acyl-CoA binding domain containing 3 (ACBD3), established the tethering. The latter allows for cholesterol redistribution of cholesterol in the nucleus to sustain the prosurvival response by blocking NF-κB deacetylation. This work proposes a previously unidentified paradigm in MRR: the formation of contact sites between mitochondria and nucleus to aid communication.

Synthesis and evaluation of a superabsorbent-fertilizer composite for maximizing the nutrient and water use efficiency in forestry plantations

Reducing fertilizer use is a priority in the quest for sustainable forestry systems. In short rotation Eucalyptus plantations, NPK pellets are routinely added to the seedling's top soil layer at planting, potentially leading to increased seedling mortality, nutrient loss and environmental degradation. To address this triple challenge, the development of efficient fertilization practices is essential. In the present work, we synthesized a crosslinked acrylic-cellulosic superabsorbent composite (SAPH-BAL) containing small amounts of specific nutrients integrated in the polymer matrix. We analyzed the composite's chemical and rheological properties, and assessed the viability of Eucalyptus plantations supplied with it at planting. Physiological measurements confirmed the suitability of SAPH-BAL in greenhouse-grown potted seedlings subjected to different growth conditions, showing that it efficiently delivers nutrients while protecting seedlings from drought stress. Field experiments carried out at ten South American locations covering an ample range of environmental conditions confirmed the beneficial effect of SAPH-BAL on growth and survival in comparison to the conventional fertilization scheme (superabsorbent + 75 g NPK). Furthermore, it was found that plants treated with SAPH-BAL were less affected by the differences in rainfall regimes during the experiments compared to those fertilized conventionally. To the best of our knowledge this is the first report describing the successful use of superabsorbents for root targeted delivery of fertilizers in forestry operations.

Human SREBP1c expression in liver is directly regulated by peroxisome proliferator-activated receptor alpha (PPARalpha)

Sterol regulatory element binding proteins (SREBPs) regulate the expression of a number of enzymes, which catalyze the synthesis of fatty acids, cholesterol, triglycerides, and phospholipids. SREBP1c is the most relevant isoform in the adult liver, and its expression is controlled by the nutritional state. Transcriptional regulation studies into the SREBP1c gene, performed in the last few years, have improved our knowledge of the variability of signals that converge on its promoter region. Insulin, cholesterol derivatives, T3 and other endogenous molecules have been demonstrated to regulate the SREBP1c expression, particularly in rodents. The present study aimed to perform a detailed analysis of the human SREBP1c gene promoter structure in liver cells by focusing on responses to diverse metabolic signals. Serial deletion and mutation assays reveal that both SREBP (SRE) and LXR (LXRE) response elements are involved in SREBP1c transcription regulation mediated by insulin and cholesterol derivatives. We discovered that peroxisome proliferation-activated receptor alpha (PPARα) agonists enhance the activity of the SREBP1c promoter; a DR1 element, at -453 in the human promoter was involved in this activation. Moreover, PPARα agonists act in cooperation with LXR or insulin to induce lipogenesis. Collectively, our results identify PPARα as a novel regulatory factor in SREBP1c regulation which plays a relevant role in the interplay between lipids and insulin metabolic regulation.

Characterization of the human insulin-induced gene 2 (INSIG2) promoter: the role of Ets-binding motifs

Insulin-induced gene 2 (INSIG2) and its homolog INSIG1 encode closely related endoplasmic reticulum proteins that regulate the proteolytic activation of sterol regulatory element-binding proteins, transcription factors that activate the synthesis of cholesterol and fatty acids in animal cells. Several studies have been carried out to identify INSIG2 genetic variants associated with metabolic diseases. However, few data have been published regarding the regulation of INSIG2 gene expression. Two Insig2 transcripts have been described in rodents through the use of different promoters that produce different noncoding first exons that splice into a common second exon. Herein we report the cloning and characterization of the human INSIG2 promoter and the detection of an INSIG2-specific transcript homologous to the Insig2b mouse variant in human liver. Deletion analyses on 3 kb of 5'-flanking DNA of the human INSIG2 gene revealed the functional importance of a 350-bp region upstream of the transcription start site. Mutated analyses, chromatin immunoprecipitation assays, and RNA interference analyses unveiled the significance of an Ets-consensus motif in the proximal region and the interaction of the Ets family member SAP1a (serum response factor (SRF) accessory protein-1a) with this region of the human INSIG2 promoter. Moreover, our findings suggest that insulin activated the human INSIG2 promoter in a process mediated by phosphorylated SAP1a. Overall, these results map the functional elements in the human INSIG2 promoter sequence and suggest an unexpected regulation of INSIG2 gene expression in human liver.

Arthroscopic extirpation of an osteoid osteoma of the acetabulum

We present the case of a 16-year-old boy with an 18-month history of pain in the left groin for 18 months. In addition to the simple radiographic examination, magnetic resonance imaging, bone scan, and computed tomography were necessary to finally diagnose an acetabulum osteoid osteoma (AOO). Excision of the lesion was performed arthroscopically and pathologic testing confirmed the diagnosis. The patient's symptoms disappeared immediately after the surgery, and had not reappeared as of the 6-month postoperative evaluation. We conclude that arthroscopic excision of an AOO is possible and avoids the aggressive open approach as well as operative hip dislocation.

Are barrier creams actually effective?

This article reviews the current information surrounding the efficacy of barrier creams as a protective measure against contact dermatitis. The principles of the proposed effects of barrier creams on the skin and the experimental and clinical data regarding their efficacy in the prevention of irritant and allergic contact dermatitis are discussed.