Background: Mitochondrial dysfunction in retinal pigment epithelium (RPE) is a pathogenic factor in age-related macular degeneration (AMD). Improvement of mitochondrial function may ameliorate RPE bioenergetics status, which may in turn nourish the retinal photoreceptors against degenerative loss.
Objective: The purpose of this study is to examine the G-protein coupled receptor (GPCR) antagonistic drug CM-20 in modulating mitochondrial function in RPE cells.
Methods: Human-derived ARPE-19 cell line was differentiated to improve RPE morphology. Dose response of CM-20 was performed to examine mitochondrial membrane potential (MMP). Secondary validation with multiplexed live-cell mitochondrial imaging was performed. Protection of CM-20 to mitochondria against oxidative stress was detected under co-treatment with hydrogen peroxide.
Results: Treatment with CM-20 elicited a dose-dependent increase of MMP. Multiplexed live-cell mitochondrial imaging showed consistent increase of MMP at an optimal concentration of CM-20 (12.5 μM). MMP was significantly reduced under hydrogen peroxide-induced oxidative stress and treatment with CM-20 showed rescue effects to MMP.
Conclusion: CM-20 increases mitochondrial function and protects mitochondria under oxidative stress. As both GPCRs and mitochondria are potential drug targets, retinal neuroprotective testing of CM-20 is warranted in animal models of retinal degeneration.
Background: There is an urgent need for new therapies to treat cancer metastasis. Fish oil, with high omega 3 fatty acid content, has shown anticancer activity and signal transduction inhibitors have shown anti-metastatic properties.
Objective: To provide preliminary in vitro data on the anti-migration potential of signal transduction inhibitors and co-administered fish oil.
Methods: MCF-7, TamR and FasR breast cancer cell lines were used to determine the effects of combinations of PD98059, LY294002 and fish oil in growth assays. Modulations of p-Src and COX-2, both mediators of motility and invasion, were then determined by Western blotting and IHC to ascertain effects on migration potential.
Results: Migration rates for the three cell lines examined were ranked: FasR>TamR>MCF-7 (p <0.05). Addition of fish oil reduced the number of TamR cells migrating after 48h (p <0.05), while the addition of PD98059 and LY294002 also decreased migratory potential of TamR cells (p <0.05). Addition of PD98059 and LY294002 to TamR cells did not result in a significant decrease in p-Src levels; as was the case when PD98059, LY294002 and 4-hydroxytamoxifen were added to MCF-7 cells. However, the co-administration of fish oil markedly reduced p-Src and COX-2 expression in both cell lines.
Conclusion: Co-administration of a commercial fish oil with signal transduction inhibitors results in decreased cell migration via an unknown co-operative mechanism and could constitute a novel approach for the treatment of breast cancer metastasis.
Introduction: We have recently demonstrated that Lys-65 of the 62GANK65 motif of E. coli RpbL12 was affinity labeled with a tRNA analogue, resulting in the loss of activity.
Materials and methods: In this report, we show that mutations operated at the position of Lys-65 led to an impairment in the activity of the mutant ribosomes, except the K65R or K65H bL12 mutants, suggesting that the only requirement of the reaction catalyzed or facilitated by RpbL12is the positive charge of the side chain of Lys-65. We also demonstrate that Lys-65 did not play any role in the peptidyl transferase reaction with respect to puromycin, but rather assisted the binding of the incoming aminoacyl-tRNA to the ribosomal A-site.
Results & discussions: The protonated, positively charged εNH3+ form of Lys-65 is likely to participate to the binding of aa-tRNA through ionic bonds with phosphate groups, in order to insure the accurate positioning required for the nucleophilic attack of its α-amino group on the carbonyl carbone of peptidyl-tRNA.
Conclusion: This α-NH2 group is likely to be generated by the unprotonated εNH2 form of Lys-65 which is capable of withdrawing a proton from the α-NH3+ group of aa-tRNA.
Mechanism(s) involved in regulating Intratesticular Testosterone levels (iT) have assumed importance in recent years, from the point of view of hormonal contraception. Contraceptives using Testosterone (T) in combination with Progestins (P), for more effective suppression of pituitary gonadotropins thereby iT, are not 100% effective in suppressing spermatogenesis in human males, likely due to pesrsistence of Intratesticular Dihydrotestosterone (iD) in poor-responders. Several lacunae pertaining to the mechanism of action of principal male hormone T during spermatogenesis remain to be resolved. Notably, the mechanism through which T brings about the stage-specific differentiation of germ cells lacking Androgen Receptors (AR). Testosterone is a highly anabolic steroid with a rapid tissue clearance rate. T is intratesticular substrate for synthesis of Dihydrotestosterone (DHT) and Estradiol (E2) involved in spermtaogenesis. Therefore, it is important to delineate the mechanism(s) for retention of iT, in order to understand regulation of its bioavailability in testis. In depth studies, pertaining to the role of androgen-binding protein(s) in sequestration, retention and bioavailability of T/DHT are required to understand male fertility regulation. The appropriate approach to overcome this lacuna would be development of mice lacking functional testicular Androgen-Binding Protein (ABPKO), but not deficient T/DHT, Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH), in order to understand its physiological functions. Insights gained about androgen retention mechanism(s) from the ABPKO murine model will be of immense help in improving the efficacy of male hormonal contraceptives and infertility management.
Background: In modern society, irregular lifestyles are a problem. It is well known that Atopic Dermatitis (AD) occurs during physical stress in people with an irregular lifestyle. We evaluated the influence that day-and-night reversal physical stress has on AD.
Methods: Six-week-old specific-pathogen-free and conventional NC/Nga male mice were used. For the day-and-night reversal procedure, the mice ran on a treadmill at a slow speed of 10 m/min for 12 h (between 8:00 and 20:00). Then, between 20:00 and 8:00, we put the mice in a dark place. This treatment was repeated every day for two weeks. The behavioral circadian rhythm of the mice was evaluated with the open field test. Then, the mice were sacrificed and histological examinations of the tissues, the expression of peptide hormones, corticosterone, Immunoglobulin E, histamine, and cytokines was performed using an enzyme-linked immunosorbent assay.
Results: In the treadmill-treated conventional NC/Nga mice, AD symptoms were deteriorated compared with the non-treated conventional NC/Nga mice. The levels of Period (Per) 2, Clock, and brain and muscle arnt-like protein 1 (Bmal1) in the skin were increased constantly in the treadmill-treated conventional mice. Furthermore, the expression of Retinoic Acid-related Orphan Receptor (ROR)α, which activates Bmal1, was increased in the treadmill-treated conventional mice compared with the non-treated conventional mice. In addition, when non-treated conventional mice were administrated by the agonist of RORα, AD symptoms were deteriorated similar to treadmill-treated conventional mice.
Conclusion: In the day-and-night reversal mice, the clock genes were increased constantly, indicating that this is a factor that deteriorated AD.
Objective: MicroRNAs (miRNAs) can regulate various genes after binding to target mRNAs. Studies on Inflammatory Bowel Disease (IBD) in relation with miRNA are much less shown. The aim of the present study was to assess the expression patterns of microRNA 106a and microRNA 362-3p in peripheral blood samples of Inflammatory Bowel Disease (IBD) patients including Crohn's Disease(CD) and Ulcerative Colitis (UC).
Methods: This study consisted of 32 CD, 32 UC patients and 32 controls. The expression level of the micro-RNAs -106a and -362-3p was determined using reverse transcription and real-time RT-PCR.
Results: Our findings showed that MiR-106a and miR-362-3p are expressed at significantly higher levels in the peripheral blood from patients with CD and UC compared to controls. MiR-106a and miR-362-3p expression are also different in the peripheral blood of patients regarding the activity score of the disease. There were significant differences of miR362-3p in active UC relative to inactive UC.
Conclusion: Altogether our findings suggest that miR-106a and miR-363-3p can play an important role in the pathogenesis of IBD. The differences in expression of miR106a and miR362-3p in peripheral blood of the UC and CD patients in an active phase in comparison to inactive disease suggest that these miRNAs may be useful as potential biomarkers for diagnosis and monitoring the disease activity.
Background: Among electromagnetic fields treatments used in orthopedics, extremely low-frequency magnetic fields (ELF MF) need more detailed information about the molecular mechanisms of their effects and exposure conditions.
Objective: Evaluation of the effects of an ELF MF exposure system, recently introduced among current clinical treatments for fracture healing and other bone diseases, on Alkaline Phosphatase (ALP) activity and expression in a human osteosarcoma cell line (SaOS-2), as marker typically associated to osteogenesis and bone tissue regeneration.
Method: Cells were exposed to the ELF MF physical stimulus (75 Hz, 1.5 mT) for 1h. Cell viability, enzymatic activity, protein and mRNA expression of alkaline phosphatase were then measured at different times after exposure (0, 4 and 24 h).
Results: Data demonstrate that this signal is active on an osteogenic process already one hour after exposure. Treatment was, in fact, capable, even after an exposure shorter than those commonly used in clinical applications, to significantly up-regulate alkaline phosphatase enzymatic activity. This regulation is produced essentially through an increase of ALP protein level, without changes of its mRNA concentration, while assessed magnetic field did not affect cell growth and viability and did not produce temperature variations.
Conclusion: Tested low-frequency magnetic field affects cellular ALP expression with a posttranslational mechanism, without the involvement of regulations at gene transcription and mRNA level. This molecular effect is likely produced even within treated tissues during therapies with this signal and may be implicated in the induction of observed effects in treated patients.
Intoroduction: Dietary intake fundamentally provides reintegration of energy and essential nutrients to human organisms. However, its qualitative and quantitative composition strongly affects individual's health, possibly being either a preventive or a risk factor. It was shown that nutritional status resulting from long-term exposition to specific diet formulations can outstandingly reduce incidences of most common and most important diseases of the developed world, such as cardiovascular and neoplastic diseases. Diet formulations result from different food combinations which bring specific nutrient molecules. Numerous molecules, mostly but not exclusively from vegetal foods, have been characterized among nutritional components as being particularly responsible for diet capabilities to exert risk reduction. These "bioactive nutrients" are able to produce effects which go beyond basic reintegration tasks, i.e. energetic and/or structural, but are specifically pharmacologically active within pathophysiological pathways related to many diseases, being able to selectively affect processes such as cell proliferation, apoptosis, inflammation, differentiation, angiogenesis, DNA repair and carcinogens activation.
Conclusion: The present review was aimed to know the molecular mechanisms and pathways of activity of bioactive molecules; which will firstly allow search for optimal food composition and intake, and then use them as possible therapeutical targets and/or diagnostics. Also, the present review discussed the therapeutic effect of both nutrients and phytochemicals.
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