Mitotic Arrest Deficiency Protein 2 (MAD2) and Histone Deacetylase 6 (HDAC6) Present a Complex Relationship in Their Regulation and Expression and Subsequent Impact on Chemoresponsiveness

Introduction:
Ovarian cancer patients presenting with advanced stage (III/IV)
canceraretreatedwithcarboplatinumincombinationwithpaclitaxel.Despitea
significant initial response rate, fewer than 20% of patients become long-term
survivors. We have published that low MAD2 expression levels associate with
reduced progression free survival (PFS) in patients with high-grade serous
epithelial ovarian cancer (EOC). Moreover, we have demonstrated that MAD2
expressionisdown-regulatedbythemicroRNAmiR-433(
Furlong et al., 2011
).
Interestingly, miR-433 also down-regulates HDAC6 (
Simon et al., 2010
), which
uniquely deacetylates
a
-tubulin prior to HDAC6s binding to
b
-tubulin.
In vitro
studies have shown that HDAC6 inhibition in combination with paclitaxel
treatment enhances chemoresistant cancer cell death. To date, an interaction
between MAD2 and HDAC6 has not been reported.
Experimental design:
MAD2 and HDAC6 immunohistochemistry (IHC) and
Western blot analyses were performed to investigate the role of HDAC6 and
MAD2 in chemoresistance to paclitaxel in high-grade serous EOC.
Results and Discussion:
In vitro
experiments demonstrated that overex-
pression of pre-miR-433, which targets MAD2, resulted in down-regulation
of HDAC6 in EOC cell lines. High levels of HDAC6 are co-expressed with
MAD2 in the paclitaxel resistant UPN251 and OVCAR7 cell lines. While, all
4 paclitaxel resistant EOC cell lines express higher levels of miR-433 than
the paclitaxel sensitive A2780 cells, only ovca432 and ovca433 demonstrated
down-regulation of both HDAC6 and MAD2. Paclitaxel binds to
b
-tubulin and
causesmicrotubulepolymerizationinpaclitaxelsensitivecellsasdemonstrated
by tubulin acetylation in A2780 cells. However, paclitaxel failed to cause a
significant acetylation of
a
-tubulin and microtubule stabilisation in the resistant
UPN251 cells. Therefore resistance in this cell line may be mediated by
aberrantly high HDAC6 activity. We have previously shown that MAD2 knock-
down cells are resistant to paclitaxel (
Furlong F., et al., 2011; Prencipe M.,
et al., 2009
). We measured HDAC6 protein expression in MAD2 knockdown
cells and showed that MAD2 knockdown is associated with concomitant
up-regulation of HDAC6. We hypothesise that the up-regulation of HDAC6
by MAD2 knockdown renders cancer cells more resistant to paclitaxel and
increases the invasive potential of these cells. On-going experiments will test
this hypothesis. Lastly we have observed differential MAD2 and HDAC6 IHC
staining intensity in formalin fixed paraffin embedded EOC samples.
In conclusion
, we have reported on a novel interaction between MAD2 and
HDAC6 which may have important consequences for paclitaxel resistant EOC.
Moreover, understanding chemo-responsiveness in ovarian tumours will lead
to improved patient management and treatment options for women diagnosed
with this disease

"Republic of Instability":Artifice, Death and the Afterlife in Mark Doty's "Murano"

An article on a single poem by Mark Doty, published as part of the "Hospitable Forms: Post-Secular Thought in New-Century Poetics" feature.

Urban/rural variation in the influence of widowhood on mortality risk: a cohort study of almost 300,000 couples

Death of a spouse is associated with increased mortality risk for the surviving partner (the widowhood effect). We investigated whether the effect magnitude varied between urban, rural and intermediate areas, assembling death records (2001-2009) for a prospective cohort of 296,125 married couples in Northern Ireland. The effect was greatest during the first six months of widowhood in all areas and for both sexes. Subsequently, the effect was attenuated among men in rural and intermediate areas but persisted in urban areas (HRs and 95% CIs: rural 1.09 [0.99, 1.21]; urban 1.35 [1.26, 1.44]). Among women the effect was attenuated in all areas (rural 1.06 [0.96, 1.17]; urban 1.09 [1.01, 1.17]). The impacts of spousal bereavement varied between urban and more rural areas, possibly due to variation in social support provided by the wider community. We identify men in urban areas as being in greatest need of such support and a possible target for health interventions.

Inflammatory and cytotoxic effects of acrolein, nicotine, acetylaldehyde and cigarette smoke extract on human nasal epithelial cells

Background: Cigarette smoke induces a pro-inflammatory response in airway epithelial cells but it is not clear which of the various chemicals contained within cigarette smoke (CS) should be regarded as predominantly responsible for these effects. We hypothesised that acrolein, nicotine and acetylaldehyde, important chemicals contained within volatile cigarette smoke in terms of inducing inflammation and causing addiction, have immunomodulatory effects in primary nasal epithelial cell cultures (PNECs).

Methods: PNECs from 19 healthy subjects were grown in submerged cultures and were incubated with acrolein, nicotine or acetylaldehyde prior to stimulation with Pseudomonas aeruginosa lipopolysaccharide (PA LPS). Experiments were repeated using cigarette smoke extract (CSE) for comparison. IL-8 was measured by ELISA, activation of NF-κB by ELISA and Western blotting, and caspase-3 activity by Western blotting. Apoptosis was evaluated using Annexin-V staining and the terminal transferase-mediated dUTP nick end-labeling (TUNEL) method.

Results: CSE was pro-inflammatory after a 24 h exposure and 42% of cells were apoptotic or necrotic after this exposure time. Acrolein was pro-inflammatory for the PNEC cultures (30 μM exposure for 4 h inducing a 2.0 fold increase in IL-8 release) and also increased IL-8 release after stimulation with PA LPS. In contrast, nicotine had anti-inflammatory properties (0.6 fold IL-8 release after 50 μM exposure to nicotine for 24 h), and acetylaldehyde was without effect. Acrolein and nicotine had cellular stimulatory and anti-inflammatory effects respectively, as determined by NF-κB activation. Both chemicals increased levels of cleaved caspase 3 and induced cell death.

Conclusions: Acrolein is pro-inflammatory and nicotine anti-inflammatory in PNEC cultures. CSE induces cell death predominantly by apoptotic mechanisms. 

Combining multi-band and frequency-filtering techniques for speech recognition in noisy environments

While current speech recognisers give acceptable performance in carefully controlled environments, their performance degrades rapidly when they are applied in more realistic situations. Generally, the environmental noise may be classified into two classes: the wide-band noise and narrow band noise. While the multi-band model has been shown to be capable of dealing with speech corrupted by narrow-band noise, it is ineffective for wide-band noise. In this paper, we suggest a combination of the frequency-filtering technique with the probabilistic union model in the multi-band approach. The new system has been tested on the TIDIGITS database, corrupted by white noise, noise collected from a railway station, and narrow-band noise, respectively. The results have shown that this approach is capable of dealing with noise of narrow-band or wide-band characteristics, assuming no knowledge about the noisy environment.

Belief change with noisy sensing in the situation calculus

Situation calculus has been applied widely in arti?cial intelligence to model and reason about actions and changes in dynamic systems. Since actions carried out by agents will cause constant changes of the agents’ beliefs, how to manage
these changes is a very important issue. Shapiro et al. [22] is one of the studies that considered this issue. However, in this framework, the problem of noisy sensing, which often presents in real-world applications, is not considered. As a
consequence, noisy sensing actions in this framework will lead to an agent facing inconsistent situation and subsequently the agent cannot proceed further. In this paper, we investigate how noisy sensing actions can be handled in iterated
belief change within the situation calculus formalism. We extend the framework proposed in [22] with the capability of managing noisy sensings. We demonstrate that an agent can still detect the actual situation when the ratio of noisy sensing actions vs. accurate sensing actions is limited. We prove that our framework subsumes the iterated belief change strategy in [22] when all sensing actions are accurate. Furthermore, we prove that our framework can adequately handle belief introspection, mistaken beliefs, belief revision and belief update even with noisy sensing, as done in [22] with accurate sensing actions only.

An exploration of integrated data on the social dynamics of suicide among women

The gender based nature of suicide related behaviour is largely accepted.However, studies which report exclusively on female fatal suicides are rare.Here we demonstrate how female fatal suicide has effectively been ‘othered’ and appears ‘incidental’ in studies which compare female behaviour with that of their male counterparts. We highlight how recent studies of suicide have tended to be dominated by male only approaches,which increasingly link issues of masculinity with male death by suicide.Drawing on data collected from the GP and Coroner’s office, we then apply the Sociological Autopsy approach to a cohort of 78 deaths recorded as suicides in the UK between 2007 and 2009. By focusing on females in isolation from males, we demonstrate that as in male suicide only studies,it is similarly possible to draw out issues associated with the feminine identity which can be linked to death by suicide. We identify that bereavement, sexual violence and motherhood could all be linked to the lives and help-seeking of the females who died. In closing, we suggest are orientation towards sociological analytic approaches of female suicide may help to produce further reductions in the rate of female death by suicide.

Dimensions of Suicide Research: Substance misuse in life and death in a 2-year cohort of suicides

Background
While substance misuse is a key risk factor in suicide relatively little is known about the relationship between lifetime misuse and misuse in suicide.

Aim
To examine the relationship between a history of substance misuse and misuse at the time of a suicide.

Method
Linkage of Coroner reports of 403 suicides occurring over two years with associated primary care records. History of substance misuse was defined as alcohol misuse and/or prescription or illicit drug misuse, for which medical help was sought.

Results
With alcohol misuse: 65% of the cohort had previously sought help and 42% were intoxicated at the suicide (with 30% of these seeing their GP in the previous year). With misuse of other substances: 54% of the cohort were tested for blood toxicology (37% of these tested positive) - with positive toxicology defined as an excess of prescription drugs over the therapeutic minima and/or detection of illicit substances. Those tested were more likely to be young and have a history of drug abuse.

Conclusion
Understanding the links between substance misuse and the use of substances in conjunction with the act of suicide is discussed in light of the study results and current pathology and coroner practices.

RIP kinases: key decision makers in cell death and innate immunity

Innate immunity represents the first line of defence against invading pathogens. It consists of an initial inflammatory response that recruits white blood cells to the site of infection in an effort to destroy and eliminate the pathogen. Some pathogens replicate within host cells, and cell death by apoptosis is an important effector mechanism to remove the replication niche for such microbes. However, some microbes have evolved evasive strategies to block apoptosis, and in these cases host cells may employ further countermeasures, including an inflammatory form of cell death know as necroptosis. This review aims to highlight the importance of the RIP kinase family in controlling these various defence strategies. RIP1 is initially discussed as a key component of death receptor signalling and in the context of dictating whether a cell triggers a pathway of pro-inflammatory gene expression or cell death by apoptosis. The molecular and functional interplay of RIP1 and RIP3 is described, especially with respect to mediating necroptosis and as key mediators of inflammation. The function of RIP2, with particular emphasis on its role in NOD signalling, is also explored. Special attention is given to emphasizing the physiological and pathophysiological contexts for these various functions of RIP kinases.

The emergence of DNA methylation as a key modulator of aberrant cell death in prostate cancer

It is now well established that cancer cells exhibit a number of genetic defects in the machinery that governs programmed cell death and that sabotage of apoptosis is one of the principal factors aiding in the evolution of the carcinogenic phenotype. A number of studies have implicated aberrant DNA methylation as a key survival mechanism in cancer, whereby promoter hypermethylation silences genes essential for many processes including apoptosis. To date, studies on the methylation profile of apoptotic genes have largely focused on cancers of the breast, colon and stomach, with only limited data available on prostate cancer. Here we discuss the major developments in the field of DNA methylation and its role in the regulation of aberrant apoptosis in prostate cancer. The most significant advances have involved the discovery of apoptotic gene targets of methylation, including XAF1, (fragile histidine triad (FHIT ), cellular retinol binding protein 1 (CRBP1), decoy receptor 1(DCR1), decoy receptor 2 (DCR2 ), target of methylation-induced silenceing 1 (TMS1), TNF receptor superfamily, member 6 (FAS), Reprimo (RPRM) and GLI pathogenesis-related 1 (GLIPR1). These genes are reported to be hypermethylated in prostate cancer and some offer potential as diagnostic and prognostic markers. We also introduce the concept of an 'apoptotic methylation signature' for prostate cancer and evaluate its potential in a diagnostic, prognostic and therapeutic setting.

Urban/rural variation in the influence of widowhood on mortality risk

Death of a spouse is associated with increased mortality risk for the surviving partner (the widowhood effect), although the mechanisms driving the effect are poorly understood. After acute stress and grief have dissipated, mortality risk may be increased by loss of emotional and instrumental support for daily living and so we investigated whether social support at both the household and community levels moderated the influence of spousal bereavement on mortality risk.

We assembled death records from the Northern Ireland Mortality Study spanning almost nine years for a prospective cohort of 296,125 married couples enumerated in the 2001 Census. Presence of other adults within the household and urban/rural residence were used as measures of support at the household and community levels, with informal social support perceived to be strongest in rural areas. We used Cox proportional hazards models to estimate the effects of widowhood, sex, household composition and urban/intermediate/rural residence on all-cause mortality.

Elevated mortality risk during the first six months of widowhood was found in all areas and for both sexes (range of hazard ratios 1.24, 1.57). After more than six months the effect among men was attenuated in rural but not urban areas (HRs and 95%CIs 1.09 [0.99, 1.21] and 1.35 [1.26, 1.44] respectively). Among women the effect was attenuated in both rural and urban areas (HRs 1.06 [0.96, 1.17] and 1.09 [1.01, 1.17]). Mortality risk post bereavement was not associated with presence of other adults in the household.

We found some support for the hypothesis that informal social support is beneficial for reducing the impacts of spousal loss. Rural residence had a positive effect especially among men but presence of other adults in the household had no effect. The reasons for this discrepancy require further investigation and we identify men in urban areas as being at greatest risk in the long term.

Northern Ireland Infant Death Thematic Review 2015

Co-Sleeping and bed sharing are considered the social norm for approximately 90% of the world's population, with two-thirds of the world's cultures habitually practicing mother-infant co-sleeping on the same bed. Although international studies show that the practice of co-sleeping is common, it is controversial in the public health community, as many consider it a significant risk for Sudden Infant Death Syndrome (SIDS), accounting for 50% of SIDS deaths in the UK. The report offers an international review of the evidence and provides important debates and critical knowledge for both health professionals, parents and all those organisations working to support the safety of infants in their first perinatal year.

The Effect of Community-Based Specialist Palliative Care Teams on Place of Care

BACKGROUND: Prior research on community-based specialist palliative care teams used outcome measures of place of death and/or dichotomous outcome measures of acute care use in the last two weeks of life. However, existing research seldom measured the diverse places of care used and their timing prior to death.

OBJECTIVE: The study objective was to examine the place of care in the last 30 days of life.

METHODS: In this retrospective cohort study, patients who received care from a specialist palliative care team (exposed) were matched by propensity score to patients who received usual care in the community (unexposed) in Ontario, Canada. Measured was the percentage of patients in each place of care in the last month of life as a proportion of the total cohort.

RESULTS: After matching, 3109 patients were identified in each group, where 79% had cancer and 77% received end-of-life home care. At 30 days compared to 7 days before death, the exposed group's proportions rose from 33% to 41% receiving home care and 14% to 15% in hospital, whereas the unexposed group's proportions rose from 28% to 32% receiving home care and 16% to 22% in hospital. Linear trend analysis (proportion over time) showed that the exposed group used significantly more home care services and fewer hospital days (p < 0.001) than the unexposed group. On the last day of life (place of death), the exposed group had 18% die in an in-patient hospital bed compared to 29% in usual care.

CONCLUSION: Examining place of care in the last month can effectively illustrate the service use trajectory over time.

Effects of LL-37 Peptide Mimetics on Gingival Fibroblast Function

Host defence peptides, including the cathelicidin LL-37, play an important role in mucosal immunity, functioning as both antimicrobial agents and modulators of the inflammatory response. In the current climate of antibiotic resistance, the idea of using naturally occurring antimicrobial peptides, or their synthetic mimetics, to combat oral infection is particularly appealing. Objectives: The aim of this study was to investigate the effects of parent LL-37, and two peptide mimetics (KR-12 and KE-18), on cytokine expression and response to bacterial challenge by gingival fibroblasts. Methods: KR-12 and KE-18 are peptide mimetics of the biologically active, mid-region sequence of LL-37. The effects of commercially available LL-37, KR-12 and KE-18 on gingival fibroblast response to E coli and P gingivalis LPS challenge, analysed by IL-6 and IL-8 expression, were determined in cell culture by ELISA. The direct effects of each peptide on IL-6, IL-8, CXCL-1 and HGF expression were also determined by ELISA. The MTT assay was used to evaluate peptide effects on fibroblast viability. Results: LL-37 and KE-18, but not KR-12, inhibited LPS induction of inflammatory cytokine expression and directly stimulated CXCL-1 production by fibroblasts. All 3 peptides stimulated production of IL-8 and HGF. Neither LL-37 nor KE-12 affected cell viability, while KE-18, at higher concentrations, induced cell death. Conclusions: Shorter, peptide mimetics of LL-37, in particular KE-18, retain the immunomodulatory effects of the parent molecule and possess excellent potential as therapeutic agents in the treatment of oral infections including periodontal disease.

Doxorubicin induces the cleavage of Poly (ADP-ribose) polymerase, a marker of programmed cell death (apoptosis) in mouse cardiomyocytes

Cancer is one of the leading causes of death in the world. Despite this, a growing number of people are surviving the disease due to medical advancements and the development of numerous new therapies. Doxorubicin, a chemotherapeutic agent, is a widely-used and successful first-line anti-tumour treatment. However, the established toxic and deleterious effects of the drug on the cardiovascular system confer increased risk of congestive heart failure, thereby necessitating the use of reduced doxorubicin doses. In order to investigate how these events are initiated, mouse cardiomyocytes (HL-1) were treated in vitro with varying concentrations of doxorubicin (0.5-4.0 µmol/L). Following treatment (24h), a marked level of cell death was observed in comparison to untreated cardiomyocytes; the level of death appeared to correlate with the concentration of the drug used. Western blotting revealed the cleavage of full length Poly (ADP-ribose) polymerase (PARP) into 89 and 24kDa fragments, a process which is instrumental in triggering programmed cell death/apoptosis. Importantly, results suggested that this event may be independent of caspase 3 cleavage and thus activation. A number of previous studies have reported a functional role for both Mitofusin-2 (Mfn2) and NADPH oxidase 2 (Nox2) in the cardiotoxic response. Given that PARP cleavage is a validated indicator of cellular apoptosis, these results clearly indicate that this marker could be used in future studies when determining if depletion of the above proteins would cause a reduction in or eradicate the pro-apoptotic action of this agent on cardiomyocytes. Such investigations may lead to significant developments in ensuring that doxorubicin can achieve its full therapeutic anti-tumour potential without causing the subsequent deleterious effects on the cardiovascular system.