Tau nuclear translocation is a leading step in tau pathology process through P53 stabilization and nucleolar dispersion.

Tau protein abnormalities are associated with various neurodegenerative disorders, including Alzheimer's disease (AD) and traumatic brain injury (TBI). In tau-overexpressing SHSY5Y cells and iPSC-derived neuron models of frontotemporal dementia (FTD), axonal tau translocates into the nuclear compartment, resulting in neuronal dysfunction. Despite extensive research, the mechanisms by which tau translocation results in neurodegeneration remain elusive thus far. We studied the nuclear displacement of different P-tau species [Cis phosphorylated Thr231-tau (cis P-tau), phosphorylated Ser202/Thr205-tau (AT8 P-tau), and phosphorylated Thr212/Ser214-tau (AT100 P-tau)] at various time points using starvation in primary cortical neurons and single severe TBI (ssTBI) in male mouse cerebral cortices as tauopathy models. While all P-tau species translocated into the somatodendritic compartment in response to stress, cis P-tau did so more rapidly than the other species. Notably, nuclear localization of P-tau was associated with p53 apoptotic stabilization and nucleolar stress, both of which resulted in neurodegeneration. In summary, our findings indicate that P-tau nuclear translocation results in p53-dependent apoptosis and nucleolar dispersion, which is consistent with neurodegeneration.

Intra-ovarian injection of platelet-rich plasma into ovarian tissue promoted rejuvenation in the rat model of premature ovarian insufficiency and restored ovulation rate via angiogenesis modulation.

Premature Ovarian Insufficiency (POI) is viewed as a type of infertility in which the menopausal status occurs before the physiological age. Several therapeutic strategies have been introduced in clinic for POI treatment, although the outputs are not fully convincing. Platelet-rich plasma (PRP) is a unique blood product widely applied in regenerative medicine, which is based on the releasing of the growth factors present in platelets α-granules. In the current investigation, we examined the effectiveness of PRP as a therapeutic alternative for POI animals. POI in Wistar albino rats was induced by daily intraperitoneal (IP) administration of gonadotoxic chemical agent, 4-vinylcyclohexene dioxide (VCD) (160 mg/ kg) for 15 consecutive days. After POI induction, the PRP solution was directly injected intra-ovarian in two concentrations via a surgical intervention. Every two weeks post-injection, pathological changes were monitored in the ovaries using Hematoxylin-Eosin staining method, until eight weeks. Follicle Stimulating Hormone (FSH) content in serum was measured, together with the expression of the angiogenic-related transcripts ANGPT2 and KDR by real-time qPCR. Furthermore the fertility status of the treated rats was evaluated by mating trials. Histopathological examination revealed successful POI induction via the depletion of morphologically normal follicles in rats following VCD treatment compared to the control rats. The injection of PRP at two concentrations reduced the number and extent of the follicular atresia and inflammatory responses (p < 0.05). The expression of both ANGPT2 and KDR transcripts were significantly increased in POI rats due to enhanced inflammation, while these values were modulated after PRP administration (p < 0.05) compared to POI rats. FSH showed a decreased trend in concentration eight weeks after PRP treatment, but not statistically significant (p > 0.05). Nevertheless, a clear improvement in litter counts was found in POI rats receiving PRP compared to the non-treated POI group, being able to consider PRP as a facile, quick, accessible, safe and relatively cheap alternative therapeutic strategy to revert POI-related pathologies.

Investigating the role of endogenous opioid system in chloroquine-induced phospholipidosis in rat liver by morphological, biochemical and molecular modelling studies.

Drug-induced phospholipidosis (DIPL) is characterized by phospholipid storage in the lysosomes of affected tissues. Many severe effects and toxicities have been linked to DIPL. The aim of this study was to determine whether the endogenous opioid system is involved in chloroquine-induced phospholipidosis. The effect of naltrexone as an antagonist of opioid receptors in chloroquine-induced phospholipidosis in rat liver was investigated by morphological, biochemical, and molecular modelling studies. Transmission electron microscopy (TEM) showed that morphological characteristic changes of rat liver, including the number of lamellar bodies, grade of vacuolization and cell steatosis, were markedly attenuated in rats treated with naltrexone alone or in combination with chloroquine, in comparison with chloroquine-treated rats. The results of liquid chromatography mass spectrometry (LC/MS) showed that the concentrations of phenylacetylglycine (PAG) and hippuric acid (HA) were significantly decreased and increased, respectively, in target groups. Besides, the concentration ratio of PAG/HA was significantly decreased. Spectrophotometry resulted in a notable decrease in alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activities in target groups. The results from the molecular docking and molecular dynamic simulation studies demonstrated clear chloroquine interaction with the active site cavity of the µ opioid receptor. These data suggest that administration of naltrexone alone, or in combination with chloroquine, notably attenuates the side effects of chloroquine-induced phospholipidosis, as well as demonstrating an increased probability of the endogenous opioid system involvement in chloroquine-induced phospholipidosis in rat liver.

Personalizing the safe, appropriate and effective concentration(s) of ozone for a non-diabetic individual and four type II diabetic patients in autohemotherapy through blood hemoglobin analysis.

BACKGROUND: Diabetes is a chronic disease associated with many problems and high costs. In recent decades, a lot of research has been carried out in order to improve methods of treatment of diabetic patients. One of the currently used complementary therapies for diabetes is ozone therapy or autohemotherapy. The beneficial effects of ozone has been proven in many diseases such as diabetes, but the critical issue is the determination of the safe and effective concentration of ozone reacting with blood and in particular hemoglobin. METHODS: A number of spectroscopic techniques including intrinsic fluorescence, circular dichroism and UV-VIS spectroscopies were used as well as SDS-PAGE, Native-PAGE and dynamic light scattering to analyze the effect of ozonation on hemoglobin of a non-diabetic individual and four diabetic patients in order to find the appropriate concentration(s) of ozone for personalized autohemotherapy. RESULTS: In this study, we determined the personalized concentration(s) for a safe and effective ozonation of a non-diabetic individual and four diabetic type II patients, based on blood hemoglobin analysis. CONCLUSIONS: A number of techniques were used to determine the personalized ozone concentration(s) for a safe and effective autohemotherapy based on blood hemoglobin analysis. SDS-PAGE and dynamic light scattering were identified as the two main techniques needed for personalizing the ozone concentration(s) for each individual as otherwise hemoglobin in blood can oligomerise and cause serious damage if the inappropriate ozone concentration is used.

Ovarian function and reproductive outcome after ovarian tissue transplantation: a systematic review.

The aim of this systematic review study is to summarize the current knowledge of ovarian tissue transplantation and provide insight on ovarian function, fertility and reproductive outcome following ovarian tissue transplantation. Relevant studies were identified by searching through PubMed, Cochrane Library, Embase, ProQuest, and Scopus databases until August 2018. Ovarian function by examination of the hormonal level was evaluated, together with follicular growth, the return of menstrual cycle and assessment of reproductive consequences: pregnancy, miscarriage rates and live birth after transplantation. Studies including female patients aged between 22 and 49 years that were subjected to ovarian tissue transplantation were considered. A total of 1185 studies were identified in the primary search. Titles and abstracts were screened for assessment of the inclusion criteria. Finally, twenty-five articles met the criteria and were included in this study. In general, 70% of patients that underwent ovarian tissue transplantation had ovarian and endocrine function restoration as well as follicular growth. Pregnancy was reported with 52% of the patients. The available evidence suggests that ovarian tissue transplantation is a useful and an applied approach to restore hormonal function, endocrine balance and eventually fertility outcomes in patients that are predisposed to lose their fertility, diagnosed with premature ovarian failure (POF), as well as women undergoing cancer treatments. Identification of the techniques with the lowest invasions for follicular and oocyte development after ovarian tissue transplantation aiming to reduce probable adverse effects after treatment is indispensable.

Cytotoxic effects and apoptosis induction of cisplatin-loaded iron oxide nanoparticles modified with chitosan in human breast cancer cells.

Cisplatin is widely used as an anticancer drug in chemotherapy of human cancers. In the field of cancer therapy, nanoparticles modified with biocompatible copolymers are suitable vehicles to effectively deliver smaller doses of hydrophobic drugs such as cisplatin in the body. In this study, we investigated whether cisplatin-loaded iron oxide nanoparticles (IONPs) modified with chitosan can exert cytotoxic effects in the human breast cancer cell line MDA-MB-231. IONPs was synthesized using eucalyptus leaf extract as a reducing and stabilizing agent. MDA-MB-231 cells were treated with different concentrations of cisplatin, cisplatin-IONPs and cisplatin-IONPs-chitosan for 24 h. Apoptosis was confirmed by flow cytometry, whereas The mRNA and protein expression of pro- and anti-apoptotic molecules were measured using Real time RT-PCR and western blotting. Treatment with both cisplatin-IONPs and cisplatin-IONPs-chitosan showed a significantly higher cytotoxic effect in comparison to the free drug alone in MDA-MB-231 cells. The levels of apoptosis in cells treated with a combination of cisplatin-IONPs-chitosan were significantly higher compared with cisplatin-IONPs and cisplatin alone. The results of this study showed that the interaction between cisplatin and iron oxide nanoparticles modified with chitosan could enhance responsiveness to cisplatin in breast cancer cells.

Prevention of recognition memory loss and moderation of mitochondrial dynamic tendency toward fusion by flavone derivatives in Aß-injected rats: a comparison between two flavonoids with different polarity.

Growing evidence sheds light on the use of flavonoids as the promising alternatives for the treatment of chronic conditions, including cancer and neurodegenerative disorders. Accordingly, in the present study, we aimed at evaluating the effects of oral intake of two structurally different flavonoids 5-hydroxy-6,7,4'-trimethoxyflavone (flavone 1) and 5,7,4'-trihydroxyflavone (flavone 2) on recognition memory, hippocampal protein level of immediate early gene cFos and mitochondrial dynamic markers in Amyloid ß (Aß)-injected rats. Recognition aspect of memory and level of proteins were measured using novel object recognition test and Western blot, respectively. Our data indicated that even though flavone 1 was more effective than flavone 2 to prevent memory impairment, feeding with both flavones alleviated memory in Aß-injected rats. Furthermore, in flavones-administered rats, mitochondrial dynamic balancing returned to the control level by the decline in Dynamin-related protein-1 protein level, a known marker for mitochondrial fission, and elevation in protein level of mitochondrial fusion factors Mitofusins 1 and 2. In parallel with behavior results, flavone 1 was more effectual on mitochondrial dynamic moderating. The more neuroprotective effects of flavone 1 could be attributed to its methylated structure leading to crossing of the blood-brain barrier with ease and metabolic stability and bioactivity.

Psychological stress effects on myelin degradation in the cuprizone-induced model of demyelination.

Multiple sclerosis (MS) is known as the most common demyelinating disease worldwide in which previous studies have shown that stress is a risk factor for the disease's onset and progression. Nevertheless, further studies are needed to investigate the consequences of stress in MS pathology. In this study, after 5 days of exposure to psychological and physical stress as a repetitive distress modality, rats were treated with cuprizone. The demyelination degree was compared in animal groups using Luxol fast blue staining, immunohistochemical staining for myelin basic protein and transmission electron microscopy. Outcomes revealed that animals exposed to stress prior to cuprizone ingestion, elicit more intense demyelination. Continuous psychological distress has more severe effects on myelin sheath destruction in the preclinical stage.

Human organotypic retinal flat-mount culture (HORFC) as a model for retinitis pigmentosa11.

The splicing factor PRPF31 is the most commonly mutated general splicing factor in the retinitis pigmentosa. We used a rapid, convenient and cost effective transfection method with an efficient PRPF31 knockdown in HORFC in order to study the effect of PRPF31 downregulation on retinal gene expressions in an ex vivo model. Modified calcium phosphate method was used to transfect HORFC by PRPF31 siRNA. Different times and doses of siRNA for transfection were assayed and optimum condition was obtained. PRPF31 mRNA and protein downregulation were assessed by qRTPCR and Western blot. The tissue viability of HORFC was measured using the MTT. ImageJ analysis on stained retinal sections by immunohistochemistry was used for thickness measurement of outer nuclear photoreceptor layer. The PRPF31 gene downregulation effects on retinal specific gene expression were analyzed by qRTPCR. A total of 50 nM of PRPF31 siRNA transfection after 63 h in HORFC, showed the optimum reduction in the level of PRPF31 mRNA and protein as shown by qRTPCR and Western blot (over 90% and 50% respectively). The PRPF31 mRNA silencing with calcium phosphate had no effect on cell viability in the period of the experiment. Thickness measurement of outer nuclear photoreceptor layer with IHC showed the significant reduction after 63 h of study (P value = 0.02). siRNA induced PRPF31 knockdown, led to reduction of retinal specific mRNA gene expression involved in phototransduction (RHO, GNAT1, RP1), photoreceptor structure (ROM1, FSCN2, CA4, SEMA4) and transcription factor (CRX) (fold change >5), after 63 h.

AAV delivery of GRP78/BiP promotes adaptation of human RPE cell to ER stress.

Adeno associated virus (AAV)-mediated gene delivery of GRP78 (78 kDa glucose-regulated protein) attenuates the condition of endoplasmic reticulum (ER) stress and prevents apoptotic loss of photoreceptors in Retinitis pigmentosa (RP) rats. In the current study we overexpressed Grp78 with the help of AAV-2 in primary human retinal pigmented epithelium (hRPE) cell cultures and examined its effect on cell response to ER stress. The purpose of this work was studying potential stimulating effect of GRP78 on adaptation/pro-survival of hRPE cells under ER stress, as an in vitro model for RPE degeneration. To investigate the effect of Grp78 overexpression on unfolded protein response (UPR) markers under ER stress, hRPE primary cultures were transduced by recombinant virus rAAV/Grp78, and treated with ER stressor drug, tunicamycin. Expression changes of four UPR markers including GRP78, PERK, ATF6α, and GADD153/CHOP, were assessed by real-time PCR and western blotting. We found that GRP78 has a great contribution in modulation of UPR markers to favor adaptive response in ER-stressed hRPE cells. In fact, GRP78 overexpression affected adaptation and apoptotic phases of early UPR, through enhancement of two master regulators/ER stress sensors (PERK and ATF6α) and down-regulation of a key pro-apoptotic cascade activator (GADD153/CHOP). Together these findings demonstrate the promoting effect of GRP78 on adaptation/pro-survival of hRPE cells under ER stress. This protein with anti-apoptotic actions in the early UPR and important role in cell fate regulation, can be recruited as a useful candidate for future investigations of RPE degenerative diseases.

Redistribution of cell cycle by arsenic trioxide is associated with demethylation and expression changes of cell cycle related genes in acute promyelocytic leukemia cell line (NB4).

PML-RARα perturbs the normal epigenetic setting, which is essential to oncogenic transformation in acute promyelocytic leukemia (APL). Transcription induction and recruitment of DNA methyltransferases (DNMTs) by PML-RARα and subsequent hypermethylation are components of this perturbation. Arsenic trioxide (ATO), an important drug in APL therapy, concurrent with degradation of PML-RARα induces cell cycle change and apoptosis. How ATO causes cell cycle alteration has remained largely unexplained. Here, we investigated DNA methylation patterns of cell cycle regulatory genes promoters, the effects of ATO on the methylated genes and cell cycle distribution in an APL cell line, NB4. Analysis of promoter methylation status of 22 cell cycle related genes in NB4 revealed that CCND1, CCNE1, CCNF, CDKN1A, GADD45α, and RBL1 genes were methylated 60.7, 84.6, 58.6, 8.7, 33.4, and 73.7%, respectively, that after treatment with 2 µM ATO for 48 h, turn into 0.6, 13.8, 0.1, 6.6, 10.7, and 54.5% methylated. ATO significantly reduced the expression of DNMT1, 3A, and 3B. ATO induced the expression of CCND1, CCNE1, and GADD45α genes, suppressed the expression of CCNF and CDKN1A genes, which were consistent with decreased number of cells in G1 and S phases and increased number of cells in G2/M phase. In conclusion, demethylation and alteration in the expression level of the cell cycle related genes may be possible mechanisms in ATO-induced cell cycle arrest in APL cells. It may suggest that ATO by demethylation of CCND1 and CCNE1 and their transcriptional activation accelerates G1 and S transition into the G2/M cell cycle arrest.

Chemical composition and antifungal activity of Satureja hortensis L. essentiall oil against planktonic and biofilm growth of Candida albicans isolates from buccal lesions of HIV(+) individuals.

ETHNOPHARMACOLOGICAL RELEVANCE: Oral candidiasis is an opportunistic infection of the oral cavity which usually occurs in the immunocompromised individuals. Candida albicans (C. albicans) is the most common species of yeast responsible for oral candidiasis. This study investigated the effects of Satureja hortensis L. essentiall oil (EO) on the planktonic, biofilm formation and mature biofilms of C. albicans isolates from buccal lesions of HIV(+) individuals. MATERIALS AND METHODS: MTT reduction assay, broth micro-dilution method and scanning electron microscopy (SEM) were employed to determine the effect of mentioned EO on the C. albicans planktonic and biofilm forms. GC-GC/MS was used to detect the major active compounds of EO. RESULTS: Thymol (45.9%), gamma-terpinen (16.71%), carvacrol (12.81%) and p-cymene (9.61%) were found as the most abundant constituents. MIC values ranged from 250 to 400 µg/ml and MFC values ranged from 350 to 500 µg/ml. All C. albicans isolates formed biofilm on polystyrene plats but the quantity of biofilm mass (optical density) was different for the isolates ranging from 0.850 to 0.559 nm. The mean of biofilm formation by C. albicans isolates was reduced by 87.1 ± 3.7%, 73.6 ± 5.1%, 69.4 ± 5.3% and 67 ± 4.2% at 4800, 3200, 2400 and 1600 µg/ml, respectively. In sub-MIC concentration, SEM analysis revealed loosening of cells, deformity of three dimensional structures of biofilms and shrinkage in cell membranes of sessile cells. CONCLUSIONS: In conclusion, the substantial anti-fungal activity showed by S. hortensis L. EO suggests exploitation of this oil as potential natural anti-biofilm product to deal with the problem of buccal cavity lesion associated with C. albicans.

Variations of glutamate concentration within synaptic cleft in the presence of electromagnetic fields: an artificial neural networks study.

Glutamate is an excitatory neurotransmitter that is released by the majority of central nervous system synapses and is involved in developmental processes, cognitive functions, learning and memory. Excessive elevated concentrations of Glu in synaptic cleft results in neural cell apoptosis which is called excitotoxicity causing neurodegenerative diseases. Hence, we investigated the possibility of extremely low frequency electromagnetic fields (ELF-EMF) as a risk factor which is able to change Glu concentration in synaptic clef. Synaptosomes as a model of nervous terminal were exposed to ELF-EMF for 15-55 min in flux intensity range from 0.1 to 2 mT and frequency range from 50 to 230 Hz. Finally, all raw data by INForm v4.02 software as an artificial neural network program was analyzed to predict the effect of whole mentioned range spectra. The results showed the tolerance of all effects between the ranges from -35 to +40 % compared to normal state when glutamatergic systems exposed to ELF-EMF. It indicates that glutamatergic system attempts to compensate environmental changes though release or reuptake in order to keep the system safe. Regarding to the wide range of ELF-EMF acquired in this study, the obtained outcomes have potential for developing treatments based on ELF-EMF for some neurological diseases; however, in vivo experiments on the cross linking responses between glutamatergic and cholinergic systems in the presence of ELF-EMF would be needed.

Beneficial Effect of Flavone Derivatives on Aß-Induced Memory Deficit Is Mediated by Peroxisome Proliferator-Activated Receptor γ Coactivator 1α: A Comparative Study.

In the present study, the neuroprotective effect of 5-hydroxy-6,7,4'-trimethoxyflavone (flavone 1), a natural flavone, was investigated in comparison with another flavone, 5,7,4'-trihydroxyflavone (flavone 2) on the hippocampus of amyloid beta (Aß)-injected rats. Rats were treated with the 2 flavones (1 mg/kg/d) for 1 week before Aß injection. Seven days after Aß administration, memory function of rats was assessed in a passive avoidance test (PAT). Changes in the levels of mitochondrial transcription factor A (TFAM), peroxisome proliferator-activated receptor γ coactivator 1 α (PGC-1α), phospho-adenosine monophosphate (AMP)-activated protein kinase (pAMPK), AMPK, phospho-cAMP-responsive element-binding protein (CREB), CREB, and nuclear respiratory factor 1 (NRF-1) proteins were determined by Western blot analysis. Our results showed an improvement in memory in rats pretreated with flavonoids. At the molecular level, phosphorylation of CREB, known as the master modulator of memory processes, increased. On the other hand, the level of mitochondrial biogenesis factors, PGC-1α and its downstream molecules NRF-1 and TFAM significantly increased by dietary administration of 2 flavones. In addition, flavone 1 and flavone 2 prevented mitochondrial swelling and mitochondrial membrane potential reduction. Our results provided evidence that flavone 1 is more effective than flavone 2 presumably due to its O-methylated groups. In conclusion, it seems that in addition to classical antioxidant effect, flavones exert part of their protective effects through mitochondrial biogenesis.

Metabolism of arsenic trioxide in acute promyelocytic leukemia cells.

Arsenic trioxide (As2O3) effectively induces complete clinical and molecular remissions in acute promyelocytic leukemia (APL) patients and triggers apoptosis in APL cells. The effect induced by As2O3 is also associated with extensive genomic-wide epigenetic changes with large-scale alterations in DNA methylation. We investigated the As2O3 metabolism in association with factors involved in the production of its methylated metabolites in APL-derived cell line, NB4. We used high performance liquid chromatography (HPLC) technique to detect As2O3 metabolites in NB4 cells. The effects of As2O3 on glutathione level, S-Adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) levels were investigated. Also, we studied the expression levels of arsenic methyltransferase (AS3MT) and DNA methyltransferases (DNMT1, DNMT3a, and DNMT3b) by real-time PCR. Our results show that after As2O3 entry into the cell, it was converted into methylated metabolites, mono-methylarsenic (MMA) and dimethylarsenic (DMA). The glutathione (GSH) production was increased in parallel with the methylated metabolites formations. As2O3 treatment inhibited DNMTs (DNMT1, DNMT3a, and DNMT3b) in dose- and time-dependent manners. The SAH levels in As2O3-treated cells were increased; however, the SAM level was not affected. The present study shows that APL cell is capable of metabolizing As2O3. The continuous formation of intracellular methylated metabolites, the inhibition of DNMTs expression levels and the increase of SAH level by As2O3 biotransformation would probably affect the DNMTs-methylated DNA methylation in a manner related to the extent of DNA hypomethylation. Production of intracellular methylated metabolites and epigenetic changes of DNA methylation during As2O3 metabolism may contribute to the therapeutic effect of As2O3 in APL.

The enhanced apoptosis and antiproliferative response to combined treatment with valproate and nicotinamide in MCF-7 breast cancer cells.

Acetylation of histone is a major player in epigenetic modifications, resulting in open chromatin structures and, hence, permissive conditions for transcription-factor recruitment to the promoters, followed by initiation of transcription. Histone deacetylase inhibitors arrest cancer cell growth and cause apoptosis with low toxicity thereby constituting a promising treatment for cancer. In this study, we examined the antiproliferative effects of valproate with a combination of nicotinamide in the MCF-7 cell line. MCF-7 was treated with various concentrations of valproate. The MTT assay showed that the viability of MCF-7 cells was inhibited and the cell activity was decreased. Viability percent of valproate and nicotinamide combined treatment cells (28 ± 2) was 1.78 times increased compared with the valproate-alone (0.5 mM) treated cells (50 ± 2). Colony formation in soft agar indicated that valproate at 0.3 mM, when used alone, weakly suppressed proliferation of cells (82 ± 3) and the combination treatment of valproate + nicotinamide strongly suppressed cell proliferation (51 ± 3). The flow cytometric and microscopic analyses of HDACI combined with treated cells indicated strong apoptosis induction and nuclear morphological alterations greater than those of valproate alone. Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) analysis confirmed the efficiency of the HDAC inhibitor combination, revealing the effectively upregulated p16 and p21. Furthermore, to investigate the role of acetyl-histone H3 levels, western blot analyses have been performed and high levels of acetylated histone H3 were detected in valproate- and nicotinamide-treated cells. These results suggest that the combination treatment of valproate with nicotinamide exerts significant antitumor activity and could be a promising therapeutic candidate to treat human breast cancer.

Interaction of Aß(25-35) fibrillation products with mitochondria: Effect of small-molecule natural products.

The 25-35 fragment of the amyloid ß (Aß) peptide is a naturally occurring proteolytic by-product that retains the pathophysiology of its larger parent molecule, whose deposition has been shown to involve mitochondrial dysfunction. Hence, disruption of Aß(25-35) aggregates could afford an effective remedial strategy for Alzheimer's disease (AD). In the present study, the effect of a number of selected small-molecule natural products (polyphenols: resveratrol, quercetin, biochanin A, and indoles: indole-3-acetic acid, indole-3-carbinol (I3C)) on Aß(25-35) fibrillogenesis was explored under physiological conditions, and interaction of the resulting structures with rat brain mitochondria was investigated. Several techniques, including fluorescence, circular dichroism, and transmission electron microscopy were utilized to characterize the aggregation products, and possible mitochondrial membrane permeabilization was determined following release of marker enzymes. Results demonstrate the capacity of Aß(25-35) fibrils to damage mitochondria and suggest how small molecules may afford protection. While I3C appeared more effective in inhibiting the fibrillation process, all natural products behaved similarly in destabilizing preformed aggregates. It is concluded that elucidation of such protection may provide important insights into the development of preventive and therapeutic agents for AD.

Synergistic anticancer activity of valproate combined with nicotinamide enhances anti-proliferation response and apoptosis in MIAPaca2 cells.

Histone deacetylase is strongly associated with epigenetic regulation and carcinogenesis, and its inhibitors can induce cell cycle arrest and apoptosis of the cancer cells. In this study we aimed to examine the antiproliferative effects a combination of the valproate with nicotinamide in MIAPaca2 cell line. We revealed that valproate acted in a synergistic/additive with nicotinamide to inhibit the proliferation and induction of apoptosis in MIAPaca2 cancer cell line. MIAPaca2 was treated with various concentrations of valproate. The MTT assay and colony formation in soft agar indicated that valproate at 0.5 mM, when used alone weakly, suppressed proliferation of cells (37 ± 3.02%) whereas the combination treatment of valproate + nicotinamide significantly suppressed cell proliferation (58 ± 3.5%). The effect of nicotinamide at 25 mM on cell proliferation and cell colonization induced 50% apoptosis of MIAPaca2 cells. To identify the anti-proliferation and apoptotic effects of valproate and nicotinamide we performed flow cytometric and microscopic analyses. The results indicated significant apoptosis induction and nuclear morphological alterations greater than when valproate was used alone. Furthermore, western blot analyses was performed to study the role of acetyl-histone H3 levels, and quantitative RNA expression analyses were performed on expression of thrombospondin (TSP) and maspin genes in MIAPaca2. We found that the combination treatment of valproate + nicotinamide enhanced the expression of maspin and TSP genes and the biological response of the cell line was correlated with the increase of histone H3 acetylation after nicotinamide and valproate application. Together our findings indicate that valproate which act as inhibitor of cell proliferation and inducer of apoptosis in human cancer MIAPaca2 cells when used in combination with nicotinamide makes it a potentially good candidate for new anticancer drug development.

Multiple Roles of Apolipoprotein E4 in Oxidative Lipid Metabolism and Ferroptosis During the Pathogenesis of Alzheimer's Disease.

Alzheimer's disease (AD) is the most prevalent neurodegenerative disease worldwide and has a great socio-economic impact. Modified oxidative lipid metabolism and dysregulated iron homeostasis have been implicated in the pathogenesis of this disorder, but the detailed pathophysiological mechanisms still remain unclear. Apolipoprotein E (APOE) is a lipid-binding protein that occurs in large quantities in human blood plasma, and a polymorphism of the APOE gene locus has been identified as risk factors for AD. The human genome involves three major APOE alleles (APOE2, APOE3, APOE4), which encode for three subtly distinct apolipoprotein E isoforms (APOE2, APOE3, APOE4). The canonic function of these apolipoproteins is lipid transport in blood and brain, but APOE4 allele carriers have a much higher risk for AD. In fact, about 60% of clinically diagnosed AD patients carry at least one APOE4 allele in their genomes. Although the APOE4 protein has been implicated in pathophysiological key processes of AD, such as extracellular beta-amyloid (Aß) aggregation, mitochondrial dysfunction, neuroinflammation, formation of neurofibrillary tangles, modified oxidative lipid metabolism, and ferroptotic cell death, the underlying molecular mechanisms are still not well understood. As for all mammalian cells, iron plays a crucial role in neuronal functions and dysregulation of iron homeostasis has also been implicated in the pathogenesis of AD. Imbalances in iron homeostasis and impairment of the hydroperoxy lipid-reducing capacity induce cellular dysfunction leading to neuronal ferroptosis. In this review, we summarize the current knowledge on APOE4-related oxidative lipid metabolism and the potential role of ferroptosis in the pathogenesis of AD. Pharmacological interference with these processes might offer innovative strategies for therapeutic interventions.

Long-term demyelination and aging-associated changes in mice corpus callosum; evidence for the role of accelerated aging in remyelination failure in a mouse model of multiple sclerosis.

Multiple sclerosis (MS) is a chronic inflammatory and demyelinating disorder affecting the central nervous system. Evidence suggests that age-related neurodegeneration contributes to disability progression during the chronic stages of MS. Aging is characterized by decreased regeneration potential and impaired myelin repair in the brain. It is hypothesized that accelerated cellular aging contributes to the functional decline associated with neurodegenerative diseases. We assessed the impact of aging on myelin content in the corpus callosum (CC) and compared aging with the long-term demyelination (LTD) consequents induced by 12 weeks of feeding with a cuprizone (CPZ) diet. Initially, evaluating myelin content in 2-, 6-, and 18-month-old mice revealed a reduction in myelin content, particularly at 18 months. Myelin thickness was decreased and the g-ratio increased in aged mice. Although a lower myelin content and higher g-ratio were observed in LTD model mice, compared to the normally aged mice, both aging and LTD exhibited relatively similar myelin ultrastructure. Our findings provide evidence that LTD exhibits the hallmarks of aging such as elevated expression of senescence-associated genes, mitochondrial dysfunction, and high level of oxidative stress as observed following normal aging. We also investigated the senescence-associated ß-galactosidase activity in O4+ late oligodendrocyte progenitor cells (OPCs). The senescent O4+/ß-galactosidase+ cells were elevated in the CPZ diet. Our data showed that the myelin degeneration in CC occurs throughout the lifespan, and LTD induced by CPZ accelerates the aging process which may explain the impairment of myelin repair in patients with progressive MS.