Gamma secretase inhibition: Effects on fertility and embryo-fetal development in rats

Avagacestat inhibits γ-secretase, a protease that cleaves the amyloid precursor protein (APP) to produce amyloid beta (Aβ). Aβ plaques, a predominant lesion in Alzheimer's patient's brain, is considered a mechanism driving neurodegeneration. As part of the nonclinical reproductive safety assessment, avagacestat effects on fertility and early embryonic development and embryo-fetal development were evaluated in rats. In the embryo-fetal development study, avagacestat was a selective developmental toxicant with dose-related increased fetal mortality, decreased fetal growth, and increased fetal malformations and variations (primarily affecting the axial and appendicular skeletal system) at ≥3 mg/kg/day. In the female fertility and early embryonic development study, avagacestat-related reductions in female fecundity at ≥5 mg/kg/day were attributed to impaired ovarian follicular development that was reflected in dose-dependent reductions in implantation sites, litter size, and gravid uterine weights. In the male fertility and early embryonic development study, avagacestat-related effects on reproduction could not be fully assessed because of low systemic exposures achieved due to extensive metabolism and clearance of the drug. The results obtained in these studies were consistent with pharmacologically mediated inhibition of γ-secretase and resulting inhibition of Notch processing and signaling that are key for embryonic development and ovary folliculogenesis. These findings are not considered a risk for late-onset AD where the patient population is ≥65 years old most with women who are post-menopausal. However, for treatment of early onset AD with a younger patient population, there are risks for reproductive or developmental toxicities with treatment with gamma secretase inhibitors like avagacestat.

Towards regulation of Endocrine Disrupting chemicals (EDCs) in water resources using bioassays - A guide to developing a testing strategy

Endocrine disrupting chemicals (EDCs) are found in every environmental medium and are chemically diverse. Their presence in water resources can negatively impact the health of both human and wildlife. Currently, there are no mandatory screening mandates or regulations for EDC levels in complex water samples globally. Bioassays, which allow quantifying in vivo or in vitro biological effects of chemicals are used commonly to assess acute toxicity in water. The existing OECD framework to identify single-compound EDCs offers a set of bioassays that are validated for the Estrogen-, Androgen-, and Thyroid hormones, and for Steroidogenesis pathways (EATS). In this review, we discussed bioassays that could be potentially used to screen EDCs in water resources, including in vivo and in vitro bioassays using invertebrates, fish, amphibians, and/or mammalians species. Strengths and weaknesses of samples preparation for complex water samples are discussed. We also review how to calculate the Effect-Based Trigger values, which could serve as thresholds to determine if a given water sample poses a risk based on existing quality standards. This work aims to assist governments and regulatory agencies in developing a testing strategy towards regulation of EDCs in water resources worldwide. The main recommendations include 1) opting for internationally validated cell reporter in vitro bioassays to reduce animal use & cost; 2) testing for cell viability (a critical parameter) when using in vitro bioassays; and 3) evaluating the recovery of the water sample preparation method selected. This review also highlights future research avenues for the EDC screening revolution (e.g., 3D tissue culture, transgenic animals, OMICs, and Adverse Outcome Pathways (AOPs)).

Development of an estrogen-dependent breast cancer co-culture model as a tool for studying endocrine disruptors

We developed an innovative co-culture system composed of Hs578t human mammary stromal-like cells and T47D hormone-dependent breast epithelial tumor cells as a representative in vitro model of the human hormone-dependent mammary tumor microenvironment. Hs578t cells expressed aromatase (CYP19) mainly via the healthy stromal CYP19 promoter I.4, but also to a lesser extent via the breast cancer-relevant promoters PII, I.3 and I.7, and produced estrogens from androgen precursors. These estrogens stimulated T47D cell proliferation and estrogen receptor-dependent expression of trefoil factor-1 (TFF1), which is known to stimulate mammary tumor cell proliferation and migration. Hs578t cells can also undergo a "promoter-switch" where the normally silent CYP19 promoters PII, I.3 and I.7 become activated, which mimics the in vivo situation in human breast cancer patients. This positive feedback loop is the hallmark of the hormone-dependent breast tumor microenvironment. Using the co-culture model we designed, we evaluated the promoter-specific expression of CYP19, expression of estrogen-dependent gene TFF1, and determined the effects exhibited by basil and fennel seed essential oils on steroidogenesis in the tumor microenvironment.

Spontaneous Findings in the Eyes of Cynomolgus Monkeys (Macaca fascicularis) of Mauritian Origin

Spontaneous findings noted in the eyes of Mauritian cynomolgus monkeys are described and descriptions are supplemented with illustrations. Findings observed after extensive histopathologic examinations (20 to 44 sections per eye) from 20 control, 17 treatment-naive stock monkeys, and 2 findings noted in drug-treated monkeys that were considered to be spontaneous are included. Also included are findings from 361 control monkeys of routine toxicity studies performed at our laboratories, for most of which a standard histopathological examination of 1 section per eye was conducted. Common observations in monkeys examined extensively and in historical controls were limited to lymphocytic or mononuclear cell infiltrations of the uvea and/or conjunctiva/sclera and, less commonly observed, melanocytoma of the ciliary body or iris. Findings noted only in monkeys examined extensively consisted of inflammation of the conjunctiva, ora serrata cysts, glial nodules, focal degeneration of the retina, cystoid degeneration of the central retina, ballooning degeneration of the ciliary epithelium, cyst of the ciliary body, and decreased pigmentation of the retinal pigment epithelium. Changes recorded only in historical controls included retinal atrophy and nuclear displacement in the retina. Lesions are discussed and compared with pertinent literature.

Abstract 3298: Diindolylmethane and its halogenated analogues induce autophagy in human prostate cancer cells via induction of the astrocyte-elevated gene-1 (AEG-1)

3,3’-diindolylmethane (DIM) and its halogenated derivatives (ring-DIMs) are recently shown to induce protective autophagy in human prostate cancer cells. The mechanism of induction of autophagy by DIM has not been elucidated. As DIM is a mitochondrial ATP synthase inhibitor, we hypothesized that DIM and ring-DIMs induce autophagy via alteration of AMP/ATP ratio and activation of AMPK signaling in prostate cancer cells. Autophagic activity was monitored by LC3B-I to LC3B-II conversion in LNCaP and C42B prostate cancer cells. Autophagic vacuoles were examined using Cyto-ID autophagy detection kit and transmission electron microscope (TEM). Protein levels for AMPK, pAMPK, acetyl-CoA carboxylase (ACC), pACC, AEG-1, pULK-1 and β-actin were measured by western blot. AMPK and AEG-1 gene expression was downregulated using siRNA. DIM and ring-DIMs induced autophagy by increasing autophagic vacuoles and LC3B-I to LC3B-II conversion in LNCaP and C42B cells. These compounds also induced AMPK, ULK-1 and ACC phosphorylation in a time dependent manner. Interestingly, DIM, 4,4’ dibromoDIM and 7,7’ dichloroDIM induced the oncogenic protein AEG-1 time dependently in LNCaP and C42B cells. Downregulation of AEG-1 or AMPK inhibited DIM- and ring-DIM-induced autophagy. Pretreatment with ULK1 inhibitor MRT 67307 or siRNAs targeting AEG-1 or AMPK potentiated the cytotoxicity of DIM and ring-DIMs. Interestingly, downregulation of AEG-1 induced senescence in cells treated with toxic concentrations of DIM or ring-DIMs, and inhibited the onset of apoptosis in response to DIM or ring-DIMs. In summary, we identified a novel mechanism for DIM- and ring-DIM-induced protective autophagy, via induction of AEG-1 and activation of AMPK. Our findings could help towards the development of novel drug therapies for prostate cancer that include selective autophagy inhibitors as adjuvants.

Citation Format: Hossam Draz, Alexander Goldberg, Thomas Sanderson, Stephen Safe. Diindolylmethane and its halogenated analogues induce autophagy in human prostate cancer cells via induction of the astrocyte-elevated gene-1 (AEG-1) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3298. doi:10.1158/1538-7445.AM2017-3298

In vitro and in vivo evaluation of dasatinib and imatinib on physiological parameters of pulmonary arterial hypertension

PURPOSE

Pulmonary arterial hypertension (PAH) results from occlusion or vasoconstriction of pulmonary vessels, leading to progressive right ventricular failure. Dasatinib, a BCR-ABL1 tyrosine kinase inhibitor (TKI) approved for the treatment of chronic myelogenous leukemia, has been associated with PAH. In contrast, the BCR-ABL1 TKI imatinib has demonstrated anti-vasoproliferative properties and has been investigated as a potential treatment for PAH. Here we describe studies evaluating the effects of dasatinib and imatinib on cardiovascular and pulmonary functions to understand the reported differential consequences of the two TKIs in a clinical setting.

METHODS

The direct effects of dasatinib and imatinib were explored in vivo to investigate possible mechanisms of dasatinib-induced PAH. In addition, effects of dasatinib and imatinib on PAH-related mediators were evaluated in vitro.

RESULTS

In rats, both TKIs increased plasma nitric oxide (NO), did not induce PAH-related structural or molecular changes in PA or lungs, and did not alter hemodynamic lung function compared with positive controls. Similarly, in the pulmonary artery endothelial cells and smooth muscle cells co-culture model, imatinib and dasatinib increased NO and decreased endothelin-1 protein and mRNA.

CONCLUSIONS

The results of these studies indicated that dasatinib did not induce physiological changes or molecular signatures consistent with PAH when compared to positive controls. Instead, dasatinib induced changes consistent with imatinib. Both dasatinib and imatinib induced biochemical and structural changes consistent with a protective effect for PAH. These data suggest that other factors of unclear etiology contributed to the development of PAH in patients treated with dasatinib.

From the Cover: Investigative Nonclinical Cardiovascular Safety and Toxicology Studies with BMS-986094, an NS5b RNA-Dependent RNA Polymerase Inhibitor

BMS-986094, a 2'-C-methylguanosine prodrug that was in development for treatment of chronic hepatitis C infection was withdrawn from Phase 2 clinical trials because of unexpected cardiac and renal adverse events. Investigative nonclinical studies were conducted to extend the understanding of these findings using more comprehensive endpoints. BMS-986094 was given orally to female CD-1 mice (25 and 150 mg/kg/d) for 2 weeks (53/group) and to cynomolgus monkeys (15 and 30 mg/kg/d) for up to 6 weeks (2-3/sex/group for cardiovascular safety, and 5/sex/group for toxicology). Endpoints included toxicokinetics; echocardiography, telemetric hemodynamics and electrocardiography, and tissue injury biomarkers (monkey); and light and ultrastructural pathology of heart, kidney, and skeletal muscle (mouse/monkey). Dose-related and time-dependent findings included: severe toxicity in mice at 150 mg/kg/d and monkeys at 30 mg/kg/d; decreased left ventricular (LV) ejection fraction, fractional shortening, stroke volume, and dP/dt; LV dilatation, increased QTc interval, and T-wave flattening/inversion (monkeys at ≥ 15 mg/kg/d); cardiomyocyte degeneration (mice at 150 mg/kg/d and monkeys at ≥ 15 mg/kg/d) with myofilament lysis/myofbril disassembly; time-dependent proteinuria and increased urine β-2 microglobulin, calbindin, clusterin; kidney pallor macroscopically; and tubular dilatation (monkeys); tubular regeneration (mice 150 mg/kg/d); and acute proximal tubule degeneration ultrastructurally (mice/monkeys); and skeletal muscle degeneration with increased urine myoglobin and serum sTnI. These studies identified changes not described previously in studies of BMS-986094 including premonitory cardiovascular functional changes as well as additional biomarkers for muscle and renal toxicities. Although the mechanism of potential toxicities observed in BMS-986094 studies was not established, there was no evidence for direct mitochondrial toxicity.

Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead

Low-dose exposures to common environmental chemicals that are deemed safe individually may be combining to instigate carcinogenesis, thereby contributing to the incidence of cancer. This risk may be overlooked by current regulatory practices and needs to be vigorously investigated.

Lifestyle factors are responsible for a considerable portion of cancer incidence worldwide, but credible estimates from the World Health Organization and the International Agency for Research on Cancer (IARC) suggest that the fraction of cancers attributable to toxic environmental exposures is between 7% and 19%. To explore the hypothesis that low-dose exposures to mixtures of chemicals in the environment may be combining to contribute to environmental carcinogenesis, we reviewed 11 hallmark phenotypes of cancer, multiple priority target sites for disruption in each area and prototypical chemical disruptors for all targets, this included dose-response characterizations, evidence of low-dose effects and cross-hallmark effects for all targets and chemicals. In total, 85 examples of chemicals were reviewed for actions on key pathways/mechanisms related to carcinogenesis. Only 15% (13/85) were found to have evidence of a dose-response threshold, whereas 59% (50/85) exerted low-dose effects. No dose-response information was found for the remaining 26% (22/85). Our analysis suggests that the cumulative effects of individual (non-carcinogenic) chemicals acting on different pathways, and a variety of related systems, organs, tissues and cells could plausibly conspire to produce carcinogenic synergies. Additional basic research on carcinogenesis and research focused on low-dose effects of chemical mixtures needs to be rigorously pursued before the merits of this hypothesis can be further advanced. However, the structure of the World Health Organization International Programme on Chemical Safety ‘Mode of Action’ framework should be revisited as it has inherent weaknesses that are not fully aligned with our current understanding of cancer biology.

The potential for chemical mixtures from the environment to enable the cancer hallmark of sustained proliferative signalling

The aim of this work is to review current knowledge relating the established cancer hallmark, sustained cell proliferation to the existence of chemicals present as low dose mixtures in the environment. Normal cell proliferation is under tight control, i.e. cells respond to a signal to proliferate, and although most cells continue to proliferate into adult life, the multiplication ceases once the stimulatory signal disappears or if the cells are exposed to growth inhibitory signals. Under such circumstances, normal cells remain quiescent until they are stimulated to resume further proliferation. In contrast, tumour cells are unable to halt proliferation, either when subjected to growth inhibitory signals or in the absence of growth stimulatory signals. Environmental chemicals with carcinogenic potential may cause sustained cell proliferation by interfering with some cell proliferation control mechanisms committing cells to an indefinite proliferative span.

Abstract B256: Ring-DIMs induce mitochondrial dysfunction and ER stress in human prostate cancer cells

We have previously shown that a series of brominated and chlorinated analogs of 3,3'-diindolylmethane (DIM) can inhibit can induce apoptosis and necrosis in androgen-dependent and androgen-independent prostate cancer cells and that addition of bromine to the 4 and 4’ position of the indole ring of DIM maximally increases the potency of the anticancer compound. To understand the upstream events leading to the activation of caspases in response to treatment with ring-DIMs in androgen-dependent LNCaP and androgen-independent LNCaP C4-2B cells by monitoring the onset of endoplasmic reticulum (ER) stress and the dysregulation of mitochondrial respiration. We found that 4,4'-dibromo- and 7,7'-dichloroDIM and DIM itself induced ER stress-dependent upregulation of CHOP, ATF4, and GRP78, while only 4,4'-dibromo and 7,7'-dichloroDIM induced phosphorylation of eIF2alpha and JNK. Both ER stress and loss of mitochondrial membrane potential were observed after treatment with 4,4'-dihaloDIMs and DIM, but not 7,7'-dihaloDIMs within 1 hour of exposure, before the appearance of later stage apoptotic events such as condensed chromatin. Salubrinal inhibited cell death induced by 4,4'-dihaloDIMs, but facilitated cell death induced by 7,7'-dihaloDIMs or DIM. Interestingly, salubrinal did not increase eIF2alpha phosphorylation after co-treatment with either DIM or ring-DIMs. However, it did restore mitochondrial membrane potential in cells treated with 4,4'dihaloDIMs and further decreased mitochondrial activity after co-treatment with 7,7'-dihaloDIMs or DIM. Moreover, cyclosporin A inhibited cell death induced by both 4,4’-dihalo and 7,7’-dihaloDIMs but not DIM. Taken together, these data suggest that the ring-DIMs induce cell death via mitochondrial dysfunction and ER stress, and that because salubrinal either stimulates or inhibits cell death in combination with specific ring-DIMs, its effects are related to mitochondrial membrane integrity and not to phosphorylation of eIF2alpha.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B256.

Citation Format: Alexander A. Goldberg, Diana Montes-Grajales, Jesus Olivero, Adam Beach, Vladimir Titorenko, Steven Safe, Thomas Sanderson. Ring-DIMs induce mitochondrial dysfunction and ER stress in human prostate cancer cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B256.

MicroRNA changes associated with atypical CYP1A1 inducer BMS-764459

The corticotrophin releasing factor (CRF) receptor I antagonist, BMS-764459 (evaluated as a potential treatment of affective disorders), was orally dosed to female Sprague-Dawley rats once daily for 2 weeks (vehicle control or 175mg/kg/day). To investigate the mechanism of BMS-764459-related liver weight increases, total liver RNA was isolated and evaluated for mRNA gene expression by microarray analysis (assessing the expression of approximately 24,000 genes) from snap-frozen tissue. Subsequently, mRNA and miRNA (microRNA) were also analyzed 5 years later from FFPE (Formalin Fixed Paraffin Embedded) samples via RT-PCR (about 800 miRNA evaluated). Genomic analyses showed that BMS-764459 induces AhR target genes with additional inductions of CYP2B, CYP3A, and Abcc3 consistent with the gene expression pattern of atypical CYP1A1 inducers. Analysis of miRNA expression identified a number of significantly affected miRNAs. To further evaluate their role in atypical CYP1A1 induction, an in silico evaluation of differentially expressed miRNA was performed and their putative mRNA 3'-UTR (untranslated region) binding sequences were evaluated. MiR-680 and miR-29a were identified as potential regulators and biomarkers of atypical CYP1A1 induction by regulating Abcc3, CYP3A and CYP2B as well as a number of AhR targeted genes.

Abstract 2426: In vitro and in vivo evaluation of dasatinib and imatinib on physiological parameters of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH), defined by increase in mean pulmonary arterial pressure (PAP), results from occlusion or vasoconstriction of the pulmonary veins and can lead to progressive right ventricular failure. The tyrosine kinase inhibitor (TKI) imatinib, indicated for chronic myelogenous leukemia (CML) is being investigated as a potential treatment for PAH, due to its anti-vasoproliferative properties. However, the TKI dasatinib also used for CML is associated with PAH in a small percentage of heavily pre-treated patients although partial or complete reversibility is seen after discontinuation of treatment. Despite the different kinase profiles, studies in rat models of PAH have shown that both TKIs are equally efficacious in reversing functional and structural PAH-related changes. Therefore, nonclinical in vivo (SD rat) and in vitro (human pulmonary artery endothelial cells/smooth muscle cells [hPAEC/hPASM) studies evaluating direct effects of the two TKIs were conducted to understand the potential mechanistic differences for the apparently different clinical effect.

The in vivo study explored direct effects of vehicle (80 mM citric acid; control), clinically relevant doses of imatinib and dasatinib (30 or 8 mg/kg/day, oral) and monocrotaline (single i.p. dose, 70 mg/kg; positive control) on PAH-related pulmonary changes in rats (1-month treatment). Monocrotaline reduced nitric oxide (NO; vasodilation) and increased endothelin-1 (ET-1; vasoconstriction) levels in plasma, induced structural changes (perivascular inflammation, EC injury and SMC proliferation) in PA and lungs, and increased (2-5× control) systolic and diastolic PAP and right ventricular pressure. In contrast, both imatinib and dasatinib increased NO in plasma (2.5×), did not any induce PAH-related structural changes (PA or lungs) and did not alter hemodynamic function compared to controls. The in vitro hPAEC/PASM co-culture model demonstrated that imatinib and dasatinib at clinically relevant (Cmax) concentrations increased NO and decreased ET-1 protein and mRNA.

Our results demonstrate that dasatinib, as imatinib, does not have the potential to directly induce PAH-related changes in vivo or in vitro. In addition, both molecules induce biochemical changes in vivo and in vitro consistent with a protective effect on PAP.

Citation Format: Mausumee Guha, James Hennan, Julia Li, Damir Simic, Jochen Woiche, Bethany Baumgart, Thomas Sanderson, Michael Graziano, Roderick Bunch. In vitro and in vivo evaluation of dasatinib and imatinib on physiological parameters of pulmonary arterial hypertension . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2426. doi:10.1158/1538-7445.AM2013-2426

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.

Combination therapy with insulin-like growth factor-1 and hypothermia synergistically improves outcome after transient global brain ischemia in the rat

OBJECTIVES

Hypothermia has a well-established neuroprotective effect and offers a foundation for combination therapy for brain ischemia. The authors evaluated the effect of combination therapy with insulin-like growth factor-1 (IGF-1) and hypothermia on brain structure and function in the setting of global brain ischemia and reperfusion in rats.

METHODS

Male Sprague-Dawley rats were randomly assigned to groups by a registrar. Animals were subjected to 8 minutes of global brain ischemia using bilateral carotid occlusion and systemic hypotension, followed by 7 days (Stage I dose studies) or 28 days (Stage II outcome studies) of reperfusion. Sham controls were subjected to surgery, but not ischemia. Stage II animals were randomized to no treatment, IGF-1 at the dose determined in Stage I, hypothermia (32°C for 4 hours), or a combination of IGF-1 and hypothermia. Stage II animals underwent 21 days of spatial memory testing. At 7 days (Stage I) or 28 days (Stage II), brains were harvested for counting of CA1 neurons. The primary Stage II outcome was a neurologic outcome index computed as the ratio of viable CA1 neurons per 300-μm field to the number of days to reach success criteria on the memory task.

RESULTS

Stage I experiments confirmed the neuroprotective effect of the hypothermia protocol and IGF-1 at a dose of 0.6 U/kg. Stage II studies suggested that early neuroprotection with hypothermia and IGF-1 was not well maintained to 28 days and that combination therapy was more beneficial than either IGF-1 or hypothermia alone. Median and interquartile ranges (IQRs) of viable neurons per 300-μm field were 114 (IQR = 99.5 to 136) for sham, three (IQR = 2 to 4.8) for untreated ischemia, four (IQR = 3 to 70.25) for ischemia treated with IGF-1 alone, 25 (IQR = 3 to 70) for ischemia treated with hypothermia alone, and 78 (IQR 47.3 to 97.5) for ischemia treated with combination therapy. Days to memory success criteria were 13.6 (IQR = 11.5 to 15.5 days) for sham, 23.5 (IQR = 20 to 25.5 days) for untreated ischemia, 17.5 (IQR = 15.5 to 25.5 days) for ischemia treated with IGF-1, 15 (IQR = 14.5 to 21 days) for ischemia treated with hypothermia, and 13.5 (IQR = 12.25 to 18.5 days) for ischemia treated with combination therapy. Neurologic outcome indices were 8.5 (IQR = 7.4 to 9.5) for sham, 0.14 (IQR = 0.08 to 0.2) for untreated ischemia, 0.18 (IQR = 0.17 to 4.6) for ischemia treated with IGF-1, 0.7 (IQR = 0.2 to 4.8) for ischemia treated with hypothermia, and 5.7 (IQR = 3.3 to 6.2) for ischemia treated with combination therapy. Statistically significant differences in neuron counts, days to memory test criteria, and outcome index were found between sham and untreated ischemic animals. Of the three treatment regimens, only combination therapy showed a statistically significant difference from the untreated ischemic group for neuronal salvage (p = 0.02), days to criteria (p = 0.043), and outcome index (p = 0.014).

CONCLUSIONS

Combination therapy with IGF-1 (0.6 U/kg) and therapeutic hypothermia (32°C for 4 hours) at the onset of reperfusion synergistically preserves CA1 structure and function at 28 days after 8 minutes of global brain ischemia in healthy male rats.

Assessing cell fusion and cytokinesis failure as mechanisms of clone 9 hepatocyte multinucleation in vitro

In this in vitro model of hepatocyte multinucleation, separate cultures of rat Clone 9 cells are labeled with either red or green cell tracker dyes (Red Cell Tracker CMPTX or Vybrant CFDA SE Cell Tracer), plated together in mixed-color colonies, and treated with positive or negative control agents for 4 days. The fluorescent dyes become cell-impermeant after entering cells and are not transferred to adjacent cells in a population, but are inherited by daughter cells after fusion. The mixed-color cultures are then evaluated microscopically for multinucleation and analysis of the underlying mechanism (cell fusion/cytokinesis). Multinucleated cells containing only one dye have undergone cytokinesis failure, whereas dual-labeled multinucleated cells have resulted from fusion.

Determination of relative Notch1 and gamma-secretase-related gene expression in puromycin-treated microdissected rat kidneys

Notch signaling pathways are involved in the regulation of cell differentiation and are highly conserved across species. Notch ligand binding leads to gamma-secretase-mediated proteolytic cleavage of the Notch receptor releasing the Notch intracellular domain, resulting in its subsequent translocation into the nucleus and gene expression regulation. To investigate the level of expression of Notch signaling pathway components in microanatomic regions following renal injury, kidneys from untreated, vehicle control, and puromycin aminonucleoside (PA, 150 mg/kg)-treated rats were evaluated. Frozen tissue sections from rats were microdissected using laser capture microdissection (LCM) to obtain glomeruli, cortical (proximal) tubules, and collecting ducts, and relative gene expression levels of Presenilin1, Notch1 and Hes1 were determined. In untreated rats, the Notch1 expression in glomeruli was higher than in the proximal tubules and similar to that in collecting ducts, whereas Presenilin1 and Hes1 expressions were highest in the collecting ducts, followed by cortical tubules and glomeruli. Following PA-induced renal injury, Hes1 gene expression increased significantly in the glomeruli and tubules compared to the collecting ducts where no injury was observed microscopically. Although these data present some evidence of change in Notch signaling related to injury, the expression of Presenilin1, Notch1, and Hes1 in the microanatomic regions of the kidney following PA treatment were not significantly different when compared to controls. These results demonstrate that there are differences in Notch-related gene expression in the different microanatomic regions of the kidneys in rats and suggest a minimal role for Notch in renal injury induced by PA. In addition, this work shows that LCM coupled with the RT-PCR can be used to determine the relative differences in target gene expression within regions of a complex organ.

Pharmacodynamics of selective inhibition of γ-secretase by avagacestat

A hallmark of Alzheimer's disease (AD) pathology is the accumulation of brain amyloid β-peptide (Aβ), generated by γ-secretase-mediated cleavage of the amyloid precursor protein (APP). Therefore, γ-secretase inhibitors (GSIs) may lower brain Aβ and offer a potential new approach to treat AD. As γ-secretase also cleaves Notch proteins, GSIs can have undesirable effects due to interference with Notch signaling. Avagacestat (BMS-708163) is a GSI developed for selective inhibition of APP over Notch cleavage. Avagacestat inhibition of APP and Notch cleavage was evaluated in cell culture by measuring levels of Aβ and human Notch proteins. In rats, dogs, and humans, selectivity was evaluated by measuring plasma blood concentrations in relation to effects on cerebrospinal fluid (CSF) Aβ levels and Notch-related toxicities. Measurements of Notch-related toxicity included goblet cell metaplasia in the gut, marginal-zone depletion in the spleen, reductions in B cells, and changes in expression of the Notch-regulated hairy and enhancer of split homolog-1 from blood cells. In rats and dogs, acute administration of avagacestat robustly reduced CSF Aβ40 and Aβ42 levels similarly. Chronic administration in rats and dogs, and 28-day, single- and multiple-ascending-dose administration in healthy human subjects caused similar exposure-dependent reductions in CSF Aβ40. Consistent with the 137-fold selectivity measured in cell culture, we identified doses of avagacestat that reduce CSF Aβ levels without causing Notch-related toxicities. Our results demonstrate the selectivity of avagacestat for APP over Notch cleavage, supporting further evaluation of avagacestat for AD therapy.

'It's this whole picture, this well-being': patients' understanding of 'feeling well' with rheumatoid arthritis

OBJECTIVES

The aim of this study was to explore the meaning of 'feeling well' for people with rheumatoid arthritis (RA).

METHODS

In-depth interviews were conducted with 23 RA patients, purposively sampled for medication type, disease duration, disease activity, age and gender. Data were analysed using Framework, emphasizing participants' personal contexts.

RESULTS

Well-being was viewed as a broad concept, with 'feeling well' being the result of an on-going process to actively engage with a changing body, self and life. Four dimensions emerged: 'Living in the body', 'Being in the mind', 'Adapting to illness' and 'Being in the world'. The physical impact of RA underpinned the global perception of well-being and was clearly described as linking to the experience of psychological well-being. Physical and psychological wellness was often affected by the individual's adaptation to RA and personal context (e.g. home environment, broader social attitudes).

DISCUSSION

Well-being is a multidimensional concept that is meaningful to RA patients regardless of medication type and disease severity. Patients commonly illustrated a process of actively engaging in cognitive and behavioural adjustments to move towards wellness. Clinical practice and research must take account of the complexity of well-being in long-term conditions, in order to fulfil patients' expectations.

Patient perspective of measuring treatment efficacy: the rheumatoid arthritis patient priorities for pharmacologic interventions outcomes

OBJECTIVE

Collaboration with patients with rheumatoid arthritis (RA) highlights that outcomes important to them include fatigue, coping, and life enjoyment. However, these are not commonly measured in clinical trials. There is little evidence about which outcomes patients would prioritize, or what factors influence patients' prioritization. Our objective was to develop a complementary core set with patients to promote inclusion of their priority outcomes in pharmacologic interventions.

METHODS

Nominal groups were conducted with RA patients to rank 63 outcomes generated from previous in-depth interviews. A multicenter postal survey provided the final selection of core outcomes for the Rheumatoid Arthritis Patient Priorities for Pharmacologic Interventions (RAPP-PI), in which RA patients rated the importance of the priority outcomes from the nominal groups and ranked the top 6.

RESULTS

Twenty-six patients participated in 5 nominal group discussions and reduced the 63 initial outcomes to the 32 most important. A total of 254 participants in the survey ranked priority treatment outcomes to form the RAPP-PI: pain, activities of daily living, joint damage, mobility, life enjoyment, independence, fatigue, and valued activities. The 8 priorities represent 3 domains of treatment outcomes: direct impact of RA, psychosocial well-being, and function/participation. Chi-square tests showed that disease severity, disease duration, sex, and patients' perceptions of managing, self-efficacy, and normality influenced the selection of priority treatment outcomes.

CONCLUSION

Collaboration with patients has captured their perspectives of priority outcomes from pharmacologic interventions. Although there is some overlap with professional core outcomes, the additional use of this complementary set will give a broader evaluation of effectiveness of interventions from the key stakeholders: patients.

What outcomes from pharmacologic treatments are important to people with rheumatoid arthritis? Creating the basis of a patient core set

OBJECTIVE

Function, patient global assessment, and pain are routinely measured in rheumatoid arthritis (RA) clinical trials. However, other patient-reported outcomes identified as important to patients in qualitative studies, such as fatigue and quality of life, are commonly not included, and modern treatment regimens may have changed patients' expectations of treatment outcomes. Our objective was to elicit patient priority treatment outcomes for pharmacologic interventions since the common use of anti-tumor necrosis factor (anti-TNF) therapy, which will form the basis of a core set of patient priorities to complement existing professional core sets.

METHODS

In-depth interviews were conducted with 23 RA patients, purposively sampled for age, sex, medication (anti-TNF or other disease-modifying antirheumatic drugs), disease severity, and work status. Grounded theory guided iterative data collection and analysis. Coding of the data was peer reviewed. A patient research partner collaborated in the research design and analysis.

RESULTS

Sixty-three different outcomes important to patients were generated from the interviews. Four major categories of patient outcomes from pharmacologic treatments were developed: "RA under control," "Doing things," "Emotional health," and "Coping with illness." The core category (or overall theme) was "Minimizing the personal impact of RA."

CONCLUSION

Although the routine outcomes of pain, function, and overall well-being were raised by the patients, they also generated a further 60 important outcomes that they look for from treatment. This difference in perspective may potentially influence treatment decisions. The next step is therefore to use these data to develop a patient core set.

Challenges for research on polyphenols from foods in Alzheimer's disease: bioavailability, metabolism, and cellular and molecular mechanisms

Polyphenols are the most abundant antioxidants in diet. Indeed, fruits, vegetables, beverages (tea, wine, juices), plants, and some herbs are loaded with powerful antioxidant polyphenols. Despite their wide distribution, research on human health benefits truly began in the mid-1990s (Scalbert, A.; Johnson, I. T.; Saltmarsh, M. Am. J. Clin. Nutr. 2005, 81, S15S-217S). Phenolic compounds have been receiving increasing interest from consumers and manufacturers because numerous epidemiological studies have suggested associations between consumption of polyphenol-rich foods or beverages and the prevention of certain chronic diseases such as cancers and cardiovascular diseases (Manach, C.; Mazur, A.; Scalbert, A. Curr. Opin. Lipidol. 2005, 16, 77-84; Duthie, S. J. Mol. Nutr. Food Res. 2007, 51, 665-674). Furthermore, in the past 10 years, research on the neuroprotective effects of dietary polyphenols has developed considerably. These compounds are able to protect neuronal cells in various in vivo and in vitro models through different intracellular targets (Ramassamy, C. Eur. J. Pharmacol. 2006, 545, 51-64). However, it is not at all clear whether these compounds reach the brain in sufficient concentrations and in a biologically active form to exert beneficial effects. On the other hand, it has become clear that the mechanisms of action of these polyphenols go beyond their antioxidant activity and the attenuation of oxidative stress. Therefore, there is a need for more research on their intracellular and molecular targets as special pathways underlying distinct polyphenol-induced neuroprotection. The focus of this review is aimed at presenting the role of some polyphenols from fruits, vegetables, and beverages in neuroprotection and particularly in Alzheimer's disease and the research challenges in this area.

Effects of lactone derivatives on aromatase (CYP19) activity in H295R human adrenocortical and (anti)androgenicity in transfected LNCaP human prostate cancer cells

Certain lactone-containing secondary plant metabolites display potent biological effects, including anti-tumor activities. This is of particular interest as these compounds appear effective against hormone-dependent cancers, such as those of breast and prostate, of which the incidence is on the rise. The mechanisms of anti-tumor action of these compounds are largely unknown. Thirteen synthetic lactone derivatives were evaluated for effects on aromatase activity and mRNA expression in H295R human adrenocortical carcinoma cells. Aromatase (CYP19) is a key enzyme in the synthesis of estrogens from androgens. Over-expression has been associated with increased risk of developing estrogen-dependent mammary tumors, and aromatase inhibitors are effective in their treatment. The androgen receptor is implicated in mediating hormone-dependent prostate tumor growth, and androgen antagonists are effective in the treatment of these cancers. Thus the (anti)androgenic effects of the lactones were also assessed in LNCaP human prostate cancer cells transfected with human androgen receptor and an androgen receptor-responsive luciferase reporter gene. Cells were exposed to lactones (0.1-100 microM) dissolved in dimethyl sulfoxide (0.1% in medium) for 24 h prior to measurement of aromatase activity using a tritiated water-release assay. Three (competitive) inhibitors of aromatase activity were identified (potencies in decreasing order): 3-(3,4-dimethoxy-phenyl)-4-(4-methoxy-phenyl)-5H-furan-2-one (CRI-7; IC(50)=1 microM; K(i)=1.0 microM), 3,4-bis-(3,4-dimethoxy-phenyl)-5H-furan-2-one (CRI-8; IC(50)=2 microM; K(i)=1.2 microM) and 3-(3,4-dimethoxy-phenyl)-4-(3,4,5-trimethoxy-phenyl)-5H-furan-2-one (CRI-9; IC(50)=3 microM; K(i)=6.8 microM). Several concentration-dependent inducers of aromatase (>2fold) were also identified (CRI-1, CRI-4 or Vioxx, CRI-11 and CRI-13). These lactones also induced pII promoter-specific CYP19 transcripts. In transfected LNCaP cells, the three aromatase inhibitors CRI-7, 8 and 9 demonstrated concentration-dependent anti-androgenicity above 0.1 microM in the presence of either 0.1 nM of dihydrotestosterone or the synthetic androgen R1881. The other lactones showed no consistent pro- or anti-androgenic effects in these LNCaP cells. Lactone moiety-containing molecules may form the structural basis for the development of potent drugs effective against hormone-dependent cancers.

Impact of polychlorinated biphenyls contamination on estrogenic activity in human male serum

Polychlorinated biphenyls (PCBs) are thought to cause numerous adverse health effects, but their impact on estrogen signaling is still not fully understood. In the present study, we used the ER-CALUX bioassay to determine estrogenic/antiestrogenic activities of the prevalent PCB congeners and PCB mixtures isolated from human male serum. The samples were collected from residents of an area with an extensive environmental contamination from a former PCB production site as well as from a neighboring background region in eastern Slovakia. We found that the lower-chlorinated PCBs were estrogenic, whereas the prevalent higher-chlorinated PCB congeners 138, 153, 170, 180, 187, 194, 199, and 203, as well as major PCB metabolites, behaved as antiestrogens. Coplanar PCBs had no direct effect on estrogen receptor (ER) activation in this in vitro model. In human male serum samples, high levels of PCBs were associated with a decreased ER-mediated activity and an increased dioxin-like activity, as determined by the DR-CALUX assay. 17beta-Estradiol (E2) was responsible for a major part of estrogenic activity identified in total serum extracts. Significant negative correlations were found between dioxin-like activity, as well as mRNA levels of cytochromes P450 1A1 and 1B1 in lymphocytes, and total estrogenic activity. For sample fractions containing only persistent organic pollutants (POPs), the increased frequency of antiestrogenic samples was associated with a higher sum of PCBs. This suggests that the prevalent non-dioxin-like PCBs were responsible for the weak antiestrogenic activity of some POPs fractions. Our data also suggest that it might be important to pay attention to direct effects of PCBs on steroid hormone levels in heavily exposed subjects.

Quantitative RT-PCR methods for evaluating toxicant-induced effects on steroidogenesis using the H295R cell line

Gene expression profiles show considerable promise for the evaluation of the toxic potential of environmental contaminants. For example, any alterations in the pathways of steroid synthesis or breakdown have the potential to Cause endocrine disruption. Therefore monitoring these pathways can provide information relative to a chemical's ability to impact endocrine function. One approach to monitoring these pathways has been to use a human adrenocortical carcinoma cell line (H295R) that expresses all the key enzymes necessary for steroidogenesis. In this study we have further developed these methods using accurate and specific quantification methods utilizing molecular beacon-based quantitative RT-PCR (Q-RT-PCR). The assay system was used to analyze the expression patterns of 11 steroidogenic genes in H295R cells. The expression of gene transcripts was measured using a real-time PCR system and quantified based on both a standard curve method using a dilution series of RNA standards and a comparative Ct method. To validate the optimized method, cells were exposed to specific and nonspecific model compounds (inducers and inhibitors of various steroidogenic enzymes) for gene expression profiling. Similar gene expression profiles were exhibited by cells treated with chemicals acting through common mechanisms of action. Overall, our findings demonstrated that the present assay can facilitate the development of compound-specific response profiles, and will provide a sensitive and integrative screen for the effects of chemicals on steroidogenesis.

Scale-down of continuous filtration for rapid bioprocess design: Recovery and dewatering of protein precipitate suspensions

The early specification of bioprocesses often has to be achieved with small (tens of millilitres) quantities of process material. If extensive process discovery is to be avoided at pilot or industrial scale, it is necessary that scale-down methods be created that not only examine the conditions of process stages but also allows production of realistic output streams (i.e., streams truly representative of the large scale). These output streams can then be used in the development of subsequent purification operations. The traditional approach to predicting filtration operations is via a bench-scale pressure filter using constant pressure tests to examine the effect of pressure on the filtrate flux rate and filter cake dewatering. Interpretation of the results into cake resistance at unit applied pressure (alpha) and compressibility (n) is used to predict the pressure profile required to maintain the filtrate flux rate at a constant predetermined value. This article reports on the operation of a continuous mode laboratory filter in such a way as to prepare filter cakes and filtrate similar to what may be achieved at the industrial scale. Analysis of the filtration rate profile indicated the filter cake to have changing properties (compressibility) with time. Using the insight gained from the new scale-down methodology gave predictions of the flux profile in a pilot-scale candle filter superior to those obtained from the traditional batch filter used for laboratory development.

Dimeric W3SO3 cluster complexes: synthesis, characterization, and potential applications as X-ray contrast agents

Our continued research on the use of heavy metal cluster complexes as a new class of X-ray contrast agents in medical diagnostic imaging is described. A series of 2:3 cluster-ligand complexes, [(W(IV)3SO3)2L3]4- (L = linear polyaminopolycarboxylate ligands), were isolated from the reaction of aqua ion [W(IV)3SO3(H2O)9]4- (prepared in large quantities through an improved literature process) with respective ligands in refluxing DMF. The salts of [(W(IV)3SO3)2L3]4- complex anions were fully characterized using routine techniques such as elemental analysis, MS, HPLC, UV-vis, IR, and NMR. The solid structures of two complex anions, [(W(IV)3SO3)2(PDTA)3]4- and [(W(IV)3SO3)2(HO-PDTA)3]4-, were determined by X-ray crystallography. They are the first examples wherein two W(IV)3SO3 clusters are complexed and linked by three ligands that contain two terminal iminodiacetate (bis-IDA) groups. Complexation of the unstable aqua ion [W(IV)3SO3(H2O)9]4- with ligands has imparted desired biological compatibility to the tungsten metal cluster. These complexes are stable and highly soluble in H2O. The potential utility of such tungsten cluster complexes as X-ray contrast agents was evaluated in both in vitro and in vivo animal studies. In addition, the syntheses of several new linear polyaminopolycarboxylate ligands used in this study are reported.

Post-translational processing of human procorticotrophin-releasing factor in transfected mouse neuroblastoma and Chinese hamster ovary cell lines

The mouse neuroblastoma cell line (Neuro 2 A) has been shown to contain the mRNA of a prohormone converting enzyme, PC2. The Chinese hamster ovary cell line (CHO) does not express PC2 mRNA, but is thought to contain the ubiquitous protease, furin. The enzyme(s) responsible for releasing corticotrophin-releasing hormone (CRH) from its precursor (proCRH) have not been identified, therefore to investigate the possible function(s) of PC2 or furin in the processing of proCRH, stable Neuro 2 A and CHO cell lines that express the 21 kDa human (h)proCRH were established. A specific two-site IRMA for CRH demonstrated that the hpreproCRH-expressing Neuro 2 A cell line cleaved the CRH precursor to the CRH peptide, and was able to release the mature peptide into cell medium at levels that were 4-fold higher than produced by the hproCRH-expressing CHO cells. RIA showed that the CHO cells secreted levels of CRH-containing peptides that were 10-fold higher than produced by the Neuro 2 A cells. Medium from the transfected CHO and Neuro 2 A cells was analysed by HPLC; this showed that CHO cells released a single protein corresponding to the unprocessed CRH precursor, whereas Neuro 2 A cells secreted two peptides, which could be identified as the 5 kDa CRH(1-41) and residual 16 kDa CRH peptides. These results suggest that Neuro 2 A cells, which contain PC2, can process proCRH to the mature peptide.