Metformin protects against diclofenac-induced toxicity in primary rat hepatocytes by preserving mitochondrial integrity via a pathway involving EPAC.

BACKGROUND AND PURPOSE: It has been shown that the antidiabetic drug metformin protects hepatocytes against toxicity by various stressors. Chronic or excessive consumption of diclofenac (DF) - a pain-relieving drug, leads to drug-induced liver injury via a mechanism involving mitochondrial damage and ultimately apoptotic death of hepatocytes. However, whether metformin protects against DF-induced toxicity is unknown. Recently, it was also shown that cAMP elevation is protective against DF-induced apoptotic death in hepatocytes, a protective effect primarily involving the downstream cAMP effector EPAC and preservation of mitochondrial function. This study therefore aimed at investigating whether metformin protects against DF-induced toxicity via cAMP-EPACs. EXPERIMENTAL APPROACH: Primary rat hepatocytes were exposed to 400 µmol/L DF. CE3F4 or ESI-O5 were used as EPAC-1 or 2 inhibitors respectively. Apoptosis was measured by caspase-3 activity and necrosis by Sytox green staining. Seahorse X96 assay was used to determine mitochondrial function. Mitochondrial reactive oxygen species (ROS) production was measured using MitoSox, mitochondrial MnSOD expression was determined by immunostaining and mitochondrial morphology (fusion and fission ratio) by 3D refractive index imaging. KEY RESULTS: Metformin (1 mmol/L) was protective against DF-induced apoptosis in hepatocytes. This protective effect was EPAC-dependent (mainly EPAC-2). Metformin restored mitochondrial morphology in an EPAC-independent manner. DF-induced mitochondrial dysfunction which was demonstrated by decreased oxygen consumption rate, an increased ROS production and a reduced MnSOD level, were all reversed by metformin in an EPAC-dependent manner. CONCLUSION AND IMPLICATIONS: Metformin protects hepatocytes against DF-induced toxicity via cAMP-dependent EPAC-2.

Peroxisomicine A1, a potential antineoplastic agent, causes micropexophagy in addition to macropexophagy.

Peroxisomicine A1 (PA1) is a potential antineoplastic agent with high and selective toxicity toward peroxisomes of tumor cells. Pexophagy is a selective autophagy process that degrades damaged peroxisomes; this process has been studied mainly in methylotrophic yeasts. There are two main modes of pexophagy in yeast: macropexophagy and micropexophagy. Previous studies showed that peroxisomes damaged by a prolonged exposition to PA1 are eliminated by macropexophagy. In this work, Candida boidinii was grown in methanol-containing media, and PA1 was added to the cultures at 2 µg/mL after they reached the mid-exponential growth phase. Samples were taken at 5, 10, 15, 20, and 25 min after the addition of PA1 and processed for ultrastructural analysis. Typical morphological characteristics of micropexophagy were observed: the direct engulfment of peroxisomes by the vacuolar membrane and the presence of the micropexophagic membrane apparatus (MIPA), which mediates the fusion between the opposing tips of the vacuole to complete sequestration of peroxisomes from the cytosol. In conclusion, here we report that, in addition to macropexophagy, peroxisomes damaged by PA1 can be eliminated by micropexophagy. This information is useful to deepen the knowledge of the mechanism of action of PA1 and of that of pexophagy per se.

Antitumor activity of a hydrogel loaded with lipophilic bismuth nanoparticles on cervical, prostate, and colon human cancer cells.

The objective of this study was to analyze the antitumor activity of a hydrogel loaded with lipophilic bismuth nanoparticles on human cervical, prostate, and colon cancer cell lines. The effect of lipophilic bismuth nanoparticles on the viability of cancer cell lines (HeLa, DU145, and HCT-116) and non-cancer lung fibroblasts (HLF; LL 47[MaDo]) was determined with the MTT cell viability assay and compared with known antineoplastic drugs. The biocompatibility at an organismal level was verified in a murine model by histological examination. A lipophilic bismuth nanoparticle hydrogel at 50 µM time-dependently inhibited the growth of the three cancer cell lines, in a time-dependent way. A 1-hour exposure to 250 µM lipophilic bismuth nanoparticle hydrogel, inhibited the growth of the three cancer cell lines. The in-vitro efficacy of lipophilic bismuth nanoparticle was similar to the one of docetaxel and cisplatin, but without inhibiting the growth of non-cancer control cells. Histology confirmed the biocompatibility of lipophilic bismuth nanoparticles as there were no signs of cytotoxicity or tissue damage in any of the evaluated organs (kidney, liver, brain, cerebellum, heart, and jejunum). In conclusion, a lipophilic bismuth nanoparticle hydrogel is an innovative, low-cost alternative for the topical treatment of cervicouterine, prostate, and colon human cancers.

Label-free bioanalysis of Leishmania infantum using refractive index tomography with partially coherent illumination.

In this work, we report the use of refractive index (RI) tomography for quantitative analysis of unstained DH82 cell line infected with Leishmania infantum. The cell RI is reconstructed by using a modality of optical diffraction tomography technique that employs partially coherent illumination, thus enabling inherent compatibility with conventional wide-field microscopes. The experimental results demonstrate that the cell dry mass concentration (DMC) obtained from the RI allows for reliable detection and quantitative characterization of the infection and its temporal evolution. The RI provides important insight for studying morphological changes, particularly membrane blebbing linked to an apoptosis (cell death) process induced by the disease. Moreover, the results evidence that infected DH82 cells exhibit a higher DMC than healthy samples. These findings open up promising perspectives for clinical diagnosis of Leishmania.

Análisis comparativo de angioplastia versus cirugía en la coronariopatía multivaso; perspectiva de un hospital comunitario / Comparative analysis of angioplasty versus surgery in multivessel coronary artery disease: A community hospital perspective

Introducción: Hasta 60% de los casos tratados con intervención coronaria percutánea (ICP) o cirugía (CRVC) tienen enfermedad coronaria de múltiples vasos (ECMV). Objetivo: Comparar la evolución clínica de estos pacientes después de su comparativo, de una cohorte tratada por ECMV con CRVC o ICP más stents farmacoactivos o bioactivos entre enero de 2004 a julio de 2011. Se utilizó expediente clínico, consignando eventos cardiovasculares adversos. Resultados: Ingresaron 134 pacientes, predominando varones con enfermedad trivascular y angina estable con un seguimiento de 35.7 ± 20.4 meses. El grupo quirúrgico tuvo más dislipidemia (41.9 vs 36.7%), diabetes (59.5 vs 38.3%), hipertensión arterial (67.6 vs 60%), infarto del miocardio antiguo (37.8 vs 23.3%) y lesión tipo C en la arteria descendente anterior (63.9 vs 30.4%), p < 0.05 para todas. Los tratados con ICP tuvieron más necesidad de revascularización repetida (30.50 vs 2.73%) p < 0.01, recurrencia de angina (44 vs 20%), ergometrías positivas (39 vs 18%), hospitalizaciones (25 vs 9%) y deterioro funcional según la New York Heart Association III o IV (22 vs 11%), p < 0.05 para todos. Conclusión: En pacientes de un hospital comunitario con ECMV, la ICP presenta una recurrencia superior de isquemia y revascularización repetida comparada con la CRVC.

Introduction: 60% of the patients treated with coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI) suffer from multivessel coronary artery disease. Objective: Our objective was to compare the clinical course of patients with this diagnosis after revascularization. Methods: We‚ consulted and compared the clinical records‚ of‚ a multivessel coronary artery disease cohort treated with either coronary artery bypass grafting or angioplasty with drug eluting stents or bioactive stents between January 2004 and July 2011, consigning adverse cardiovascular events. Results: 134 patients, mostly male, with‚ 3-vessel disease and stable angina, were followed up for‚ 35.7 ± 20.4 months. Dyslipidemia‚ (41.9 vs 36.7%),‚ diabetes mellitus type 2‚ (59.5 vs 38.3%), hypertension (67.6 vs 60%),‚ old myocardial infarction‚ (37.8 vs 23.3%) and type C lesion in left anterior descendent artery (63.9 vs 30.4%) were all more frequent in the surgery group (p < 0.05). On the other hand, the angioplasty treated patients needed more frequently revascularization (30.50 vs 2.73%; p < 0.01) and hospitalization (25 vs 9%) and had more often angina‚ (44 vs 20%), positive ergometry (39 vs 18%), and functional impairment type New York Heart Association III/IV‚ (22 vs 11%) (p < 0.05). Conclusion: In patients at a community hospital with multivessel coronary artery disease, PCI has a higher recurrence of ischemia and repeated revascularization compared to CABG.