FAD Mutations in Amyloid Precursor Protein Do Not Directly Perturb Intracellular Calcium Homeostasis

Disturbances in intracellular calcium homeostasis are likely prominent and causative factors leading to neuronal cell death in Alzheimer's disease (AD). Familial AD (FAD) is early-onset and exhibits autosomal dominant inheritance. FAD-linked mutations have been found in the genes encoding the presenilins and amyloid precursor protein (APP). Several studies have shown that mutated presenilin proteins can directly affect calcium release from intracellular stores independently of Aβ production. Although less well established, there is also evidence that APP may directly modulate intracellular calcium homeostasis. Here, we directly examined whether overexpression of FAD-linked APP mutants alters intracellular calcium dynamics. In contrast to previous studies, we found that overexpression of mutant APP has no effects on basal cytosolic calcium, ER calcium store size or agonist-induced calcium release and subsequent entry. Thus, we conclude that mutated APP associated with FAD has no direct effect on intracellular calcium homeostasis independently of Aβ production

Variability in Responses to Phoma medicaginis Infection in a Tunisian Collection of Three Annual Medicago Species

Spring black stem and leaf spot, caused by Phoma medicaginis, is an issue in annual Medicago species. Therefore, in this study, we analyzed the response to P. medicaginis infection in a collection of 46 lines of three annual Medicago species (M. truncatula, M. ciliaris, and M. polymorpha) showing different geographic distribution in Tunisia. The reaction in the host to the disease is explained by the effects based on plant species, lines nested within species, treatment, the interaction of species × treatment, and the interaction of lines nested within species × treatment. Medicago ciliaris was the least affected for aerial growth under infection. Furthermore, the largest variation within species was found for M. truncatula under both conditions. Principal component analysis and hierarchical classification showed that M. ciliaris lines formed a separate group under control treatment and P. medicaginis infection and they are the most vigorous in growth. These results indicate that M. ciliaris is the least susceptible in response to P. medicaginis infection among the three Medicago species investigated here, which can be used as a good candidate in crop rotation to reduce disease pressure in the field and as a source of P. medicaginis resistance for the improvement of forage legumes

Metastatic Clear Cell Hidradenocarcinoma: Response to Chemotherapy and Long Disease Control

Introduction: Hidradenocarcinoma is a rare aggressive tumor arising from sweat glands that may occur from preexisting hidradenoma or most frequently appears de novo. It is often located in the head and neck. It is also characterized by a high potential of local recurrence, metastasis and poor outcome. This tumor is often radiotherapy and chemotherapy resistant.Presentation of case: We report a case of a 77-year-old man with a metastatic hidradenocarcinoma to the bone and lymph nodes who was operated 7 years ago for an hidradenoma of the right foot. He was treated with capecitabine-based chemotherapy with good tolerance and obtention of partial response during 10 months. After that, his disease progressed and he died 1 year after diagnosis.Conclusion: Hidradenocarcinoma is a cancer with a poor prognosis . Because of its low prevalence and high rate of recurrence, its treatment is still controversial. Our good result demonstrates that adjunction of chemotherapy in metastatic forms is effective for a better control and long overall survival

Variability in Responses to Phoma medicaginis Infection in a Tunisian Collection of Three Annual Medicago Species

Spring black stem and leaf spot, caused by Phoma medicaginis, is an issue in annual Medicago species. Therefore, in this study, we analyzed the response to P. medicaginis infection in a collection of 46 lines of three annual Medicago species (M. truncatula, M. ciliaris, and M. polymorpha) showing different geographic distribution in Tunisia. The reaction in the host to the disease is explained by the effects based on plant species, lines nested within species, treatment, the interaction of species × treatment, and the interaction of lines nested within species × treatment. Medicago ciliaris was the least affected for aerial growth under infection. Furthermore, the largest variation within species was found for M. truncatula under both conditions. Principal component analysis and hierarchical classification showed that M. ciliaris lines formed a separate group under control treatment and P. medicaginis infection and they are the most vigorous in growth. These results indicate that M. ciliaris is the least susceptible in response to P. medicaginis infection among the three Medicago species investigated here, which can be used as a good candidate in crop rotation to reduce disease pressure in the field and as a source of P. medicaginis resistance for the improvement of forage legumes

Low Concentrations of Methamphetamine Can Protect Dopaminergic Cells against a Larger Oxidative Stress Injury: Mechanistic Study

Mild stress can protect against a larger insult, a phenomenon termed preconditioning or tolerance. To determine if a low intensity stressor could also protect cells against intense oxidative stress in a model of dopamine deficiency associated with Parkinson disease, we used methamphetamine to provide a mild, preconditioning stress, 6-hydroxydopamine (6-OHDA) as a source of potentially toxic oxidative stress, and MN9D cells as a model of dopamine neurons. We observed that prior exposure to subtoxic concentrations of methamphetamine protected these cells against 6-OHDA toxicity, whereas higher concentrations of methamphetamine exacerbated it. The protection by methamphetamine was accompanied by decreased uptake of both [3H] dopamine and 6-OHDA into the cells, which may have accounted for some of the apparent protection. However, a number of other effects of methamphetamine exposure suggest that the drug also affected basic cellular survival mechanisms. First, although methamphetamine preconditioning decreased basal pERK1/2 and pAkt levels, it enhanced the 6-OHDA-induced increase in these phosphokinases. Second, the apparent increase in pERK1/2 activity was accompanied by increased pMEK1/2 levels and decreased activity of protein phosphatase 2. Third, methamphetamine upregulated the pro-survival protein Bcl-2. Our results suggest that exposure to low concentrations of methamphetamine cause a number of changes in dopamine cells, some of which result in a decrease in their vulnerability to subsequent oxidative stress. These observations may provide insights into the development of new therapies for prevention or treatment of PD

Current Approaches Targeting the Wound Healing Phases to Attenuate Fibrosis and Scarring

Cutaneous fibrosis results from suboptimal wound healing following significant tissue injury such as severe burns, trauma, and major surgeries. Pathologic skin fibrosis results in scars that are disfiguring, limit normal movement, and prevent patient recovery and reintegration into society. While various therapeutic strategies have been used to accelerate wound healing and decrease the incidence of scarring, recent studies have targeted the molecular regulators of each phase of wound healing, including the inflammatory, proliferative, and remodeling phases. Here, we reviewed the most recent literature elucidating molecular pathways that can be targeted to reduce fibrosis with a particular focus on post-burn scarring. Current research targeting inflammatory mediators, the epithelial to mesenchymal transition, and regulators of myofibroblast differentiation shows promising results. However, a multimodal approach addressing all three phases of wound healing may provide the best therapeutic outcome

METH and 6-OHDA induced toxicity in MN9D cells.

<p>(A) MN9D cells were treated with 6-OHDA for 20 min and viability assays performed 24 hr after 6-OHDA removal. 6-OHDA killed MN9D cells in a concentration-dependent fashion with an EC₅₀ of approximately 100 µM. (B) MN9D Cells were treated with the indicated concentrations of METH for 24 hr and viability assays performed 24 hr later. METH affected ATP levels, mitochondrial dehydrogenase activity, and chromatin condensation as assessed by Hoechst staining. The average EC₅₀ for METH for the three different viability assays was between 2 and 3 mM. Data represent means ± SEM of 3–5 independent experiments. *P<0.05, ***p<0.001 compared to controls.</p

METH preconditioning affected MEK1/2 and PP2A.

<p>(A) A representative blot showing that sublethal concentrations of METH decreased the levels of pMEK1/2 and enhanced MEK1/2 activation induced by 6-OHDA. MN9D cells were treated with METH for 24 hr, the medium was changed, and cells treated with 6-OHDA for 20 min. Lysates were collected at 0, 15 min, 60 min, and 24 hr post 6-OHDA treatment. (B) Quantification of panel A in 4 independent experiments. (C) PP2A activity assay was performed as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0024722#s2" target="_blank">methods</a> section from cells treated with various METH concentrations for 24 hr. METH pretreatment decreased PP2A activity in a concentration dependent manner, although total cellular PP2A levels were not affected. *p<0.05, **p<0.01 compared to control.</p

Oxidative stability of olive oil enriched with oleaster leaves under accelerated storage conditions: Improvement of olive oil stability

Olive oil is rich in natural antioxidants that conserve its quality under storage conditions. However, there is a growing need to improve the quality of olive oil under storage conditions using phenol-enriched olive oil. In the present study, olive oil from the Chemlali cultivar was enriched with wild olive tree leaves or oleaster. The oil composition was analyzed before and after accelerated storage conditions using a Schaal test. Standard oil parameters, including free acidity; peroxide value; iodine value; specific extinction K232 and K270; fatty acid profile, and polyphenolic, chlorophyll, and carotenoid content, were evaluated for the control olive oil (COO) and the enriched olive oil (EOO). Polyphenolic compounds were identified for COO, EOO, and oleaster leaf extracts (OLE) using high-performance liquid chromatography. Antioxidant activity was analyzed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2’ azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) tests. The results showed that enriching the olive oil quantitatively and qualitatively improved the polyphenolic composition, pigment contents, and the antioxidant activity. The EOO was more resistant to oxidation under accelerated storage conditions. The addition of wild olive leaves also significantly improved the resistance of the olive oil to oxidation and can, therefore, be used as a source of natural antioxidants to improve the oxidative stability of edible oils

Effect of METH preconditioning on MnSOD, CuZnSOD, and Bcl-2 levels.

<p>(A) MN9D cells were treated with 0.5 mM METH for 24 hr and the cells lysates were analyzed for MnSOD, CuZnSOD, and Bcl-2 levels using Western blot analysis. Densitometry analysis showed that METH preconditioning did not affect MnSOD and CuZnSOD but significantly increases Bcl-2 levels. (B) METH increases Bcl-2 in basal conditions and in the presence of the ERK1/2 inhibitor U0126 but has no effects on Bcl-2 levels if the cells are pretreated with the Akt inhibitor LY294002. α-tubulin used as a loading control. Data are means ± ESM (N = 3). *p<0.05 compared to control.</p