Novel inhibitors of the calcineurin/NFATc hub - alternatives to CsA and FK506?

The drugs cyclosporine A (CsA) and tacrolimus (FK506) revolutionized organ transplantation. Both compounds are still widely used in the clinic as well as for basic research, even though they have dramatic side effects and modulate other pathways than calcineurin-NFATc, too. To answer the major open question - whether the adverse side effects are secondary to the actions of the drugs on the calcineurin-NFATc pathway - alternative inhibitors were developed. Ideal inhibitors should discriminate between the inhibition of (i) calcineurin and peptidyl-prolyl cis-trans isomerases (PPIases; the matchmaker proteins of CsA and FK506), (ii) calcineurin and the other Ser/Thr protein phosphatases, and (iii) NFATc and other transcription factors. In this review we summarize the current knowledge about novel inhibitors, synthesized or identified in the last decades, and focus on their mode of action, specificity, and biological effects

Oxidative discolouration in whole-head and cut lettuce: biochemical and environmental influences on a complex phenotype and potential breeding strategies to improve shelf-life

Lettuce discolouration is a key post-harvest trait. The major enzyme controlling oxidative discolouration has long been considered to be polyphenol oxidase (PPO) however, levels of PPO and subsequent development of discolouration symptoms have not always correlated. The predominance of a latent state of the enzyme in plant tissues combined with substrate activation and contemporaneous suicide inactivation mechanisms are considered as potential explanations for this phenomenon. Leaf tissue physical properties have been associated with subsequent discolouration and these may be influenced by variation in nutrient availability, especially excess nitrogen and head maturity at harvest. Mild calcium and irrigation stress has also been associated with a reduction in subsequent discolouration, although excess irrigation has been linked to increased discolouration potentially through leaf physical properties. These environmental factors, including high temperature and UV light intensities, often have impacts on levels of phenolic compounds linking the environmental responses to the biochemistry of the PPO pathway. Breeding strategies targeting the PALand PPOpathway biochemistry and environmental response genes are discussed as a more cost-effective method of mitigating oxidative discolouration then either modified atmosphere packaging or post-harvest treatments, although current understanding of the biochemistry means that such programs are likely to be limited in nature and it is likely that they will need to be deployed alongside other methods for the foreseeable future

The application of mechanical load onto mouse tendons by magnetic restraining represses Mmp-3 expression

Objectives Mechanical loading is crucial for tendon matrix homeostasis. Under-stimulation of tendon tissue promotes matrix degradation and ultimately tendon failure. In this study, we examined the expression of tendon matrix molecules and matrix-degrading enzymes (matrix metalloproteinases) in stress-deprived tail tendons and compared to tendons that were mechanically loaded by a simple restraining method. Data description Isolated mouse tail fascicles were either floated or restrained by magnets in cell culture media for 24 h. The gene expression of tendon matrix molecules and matrix metalloproteinases in the tendon fascicles of mouse tails were examined by real-time RT-PCR. Stress deprivation of tail tendons increase Mmp3 mRNA levels. Restraining tendons represses these increases in Mmp3. The gene expression response to restraining was specific to Mmp3 at 24 h as we did not observe mRNA level changes in other matrix related genes that we examined (Col1, Col3, Tnc, Acan, and Mmp13). To elucidate, the mechanisms that may regulate load transmission in tendon tissue, we examined filamentous (F-)actin staining and nuclear morphology. As compared to stress deprived tendons, restrained tendons had greater staining for F-actin. The nuclei of restrained tendons are smaller and more elongated. These results indicate that mechanical loading regulates specific gene expression potentially through F-actin regulation of nuclear morphology. A further understanding on the mechanisms involved in regulating Mmp3 gene expression may lead to new strategies to prevent tendon degeneration.Medicine, Faculty ofNon UBCPhysical Therapy, Department ofReviewedFacultyResearcherUndergraduat

Induction of Apoptosis by Miltefosine in Iranian Strain of Leishmania infantum Promastigotes

"nBackground: Miltefosine is a new drug of choice for the treatment of visceral leishmaniasis. Numerous experi­mental studies have shown miltefosine is effective on Leishmania donovani, however, effectiveness of miltefos­ine in treatment of L. infantum is not fully understood. The aims of the present study were to evaluate cytotoxic effects of miltefosine on Iranian strain of L. infantum, and to determine its 50% inhibitory concentration (IC50) as well as lethal dose. "nMethods: Anti-L. infantum activity of miltefosine was studied by treatment of cultured promastigotes with vari­ous concentration of miltefosine. MTT assay was used to determine L. infantum viability and the results were expressed as IC50. Annexin-V FLUOS staining was performed to study apoptotic properties of this drug by us­ing FACS flow cytometry."nResults: Miltefosine led to dose-dependent death of L. infantum with features compatible with apoptosis includ­ing cell shrinkage, DNA laddering, and externalization of phosphatidylserine with preservation of integrity of plasma membrane. The 100% effect was achieved at 22 µM and IC50 after 48 hours of incubation was 7 μM."nConclusion: Miltefosine exerts cytotoxic effect on Iranian strain of L. infantum via an apoptosis-related mechanism

Antifungal susceptibility profile and molecular epidemiology of recurrent vulvovaginal candidiasis in Yasuj, southwestern Iran

<p>Candidal vaginitis is a common infection causing various clinical presentations that can also emerge as recurrent vulvovaginal candidiasis (RVVC) in many patients. Candida albicans is the most common causative agent of RVVC. Since there is no definitive guideline for RVVC treatment, it is important to consider the species and susceptibility profile of the isolate to use the appropriate antifungals. The present study was conducted to determine the prevalence of RVVC, the etiological agents, and their antifungal susceptibility among clinically suspected patients in the Yasuj region, southwest Iran. The isolated yeasts were identified based on the morphological and molecular methods followed by antifungal susceptibility testing. Overall, 65 Candida strains were isolated from RVVC samples. Candida albicans (95.4%) were the main causative agents, followed by C. glabrata (3.1%), and C. krusei (1.53%). According to our findings, 20.7% and 22.4% of Candida isolates were resistant to fluconazole (MIC≥8 μg/mL) and clotrimazole (MIC≥1 μg/mL), receptively. Although C. albicans was still the main causative agent of RVVC incidence, the importance of accurate identification of Candida strains and determination of antifungal susceptibility are emphasized. Moreover, in this study, low drug-resistance was found among isolated Candida species in Yasuj.</p&gt