What was your motivation for performing the study?
This research is mainly driven by the appreciation that miRNA is a rather stable component not only in serum but even more so in blood cells. Our study is conducted as part of a general endeavor towards the development of miRNA blood born biomarkers. Within this framework we set out to identify disease specific miRNA signatures.

What did you find most surprising about your results and what can  we learn from this?
Most intriguing is the disease specificity of the miRNA pattern found in blood cells of patients. At this point of our research we are only at the beginning of a biological understanding of the miRNA pattern identified. Similarities in some elements of the miRNA pattern between Alzheimer’s disease patients and those with other neurological conditions, possibly reflect similar biological processes in the cells harboring the miRNAs. Knowing the identities of the miRNAs present in blood biomarkers will allow us to gain insight into aspects of the immunological response, at least for those cell types that contribute most of the miRNA signatures.

How close to the clinic do you believe miRNA blood biomarkers for Alzheimer’s disease are?
Our results make us confident that miRNA signatures can likely play a role in the future diagnosis of Alzheimer’s disease. Prior to clinical studies it is however important to clarify the biological role of the identified miRNAs and to determine to what extent the miRNA pattern reflects different stages of the disease.

Do you believe it will ever be possible to sufficiently partition an Alzheimer’s disease signature from other cohorts to make miRNA blood biomarkers the sole basis of diagnosis?
To answer this question we need to deepen our understanding of the biology of the blood born miRNA signature. Independent of the progress in our understanding of the function of miRNAs in blood cells, it is however likely that miRNA signatures will mostly play a role as companion diagnostics.

What’s next for your research?
Our primary near-term goal will be to address the question about the diagnostic potential of miRNAs as early biomarkers.  Given the situation of Alzheimer’s as a progressive disease, it appears of foremost importance to identify those miRNA that indicate the disease in the early stages.

For more on the burden of Alzheimer’s disease and efforts underway to better manage and treat the disease, see our interview with Executive Director of Alzheimer’s Disease International, Marc Wortmann.

How did this research come about, and why is there a need for a tool to improve communication and palliative care in ICUs?

Communication and support for patients and their families are of central concern in healthcare. However, evidence shows that these are often poorly addressed, especially at times of rapid changes in health status and during clinical uncertainty. The Intensive Care Unit is a setting in which patients are profoundly ill and where their circumstances can change rapidly. Previous research has highlighted concerns in relation to support for patients and families, lack of adequate control of patient’s symptoms, inconsistent or lack of communication and attention to patients and families’ individual wishes and to dignity, respect and peace in the Intensive Care Unit. This led us to believe that there was a need to improve communication and palliative care in Intensive Care Units, and to develop a tool to try and achieve this.

What are the challenges associated with communication within an ICU setting?

The Intensive Care Unit is a highly challenging environment for patients and families. Patients are normally profoundly ill making communication very difficult. The nature of that illness and its severity means that it is often difficult or impossible to communicate with them directly – many are for example unconscious and in the process of being ventilated. Their families are entering a very unfamiliar place and are often in shock about what has happened and struggle to cope with this while supporting the patient as best they can. Although the central goal of the Intensive Care Unit is to preserve or extend life, the nature of illness or trauma means that sometimes this is not possible. Staff strive to actively treat the person’s illness, and support them, and seek to extend life. However, the severity of the illnesses that individuals face means that sometimes this is not possible. Things can change quickly, and there is a lot of information for families to take in.

What is the PACE tool and how does it work?

PACE stands for psychosocial assessment and communication evaluation. The goal of developing this tool was to improve assessment and communication for all patients in the ICU, both those who may deteriorate and equally those who may recover. PACE comprises the training programme and an assessment, which is recorded in the clinical notes. The training programme involves collaborative work between the ICU and hospital palliative care team staff to look at ways to improve communication and how the PACE questions might serve as a prompt to improve social assessment and continue communication. The record within PACE asks for assessment of five aspects of care:

1) Family Details; such as children, relationships and guardianships.
2) Social Details; such as language, culture, but also financial concerns or even the need for transport and parking for the family.
3) Patient Preferences; including any previous wishes about who they would want to inform their treatment
4) Communication and information; how much the patient and the families are aware of the situation and who is key in a family  to be involved in communication. It also involves explaining what happens in the ICU and finally any other aspects which the patient, family or staff feel is important. The record then gives space for a continuing log of any communication updates. This is so when the clinical  team change during the 24 hour period, everyone is kept up to date.
5) Any other issues; a list providing useful resources as a prompt for staff to receive additional support if needed. PACE is completed by the key worker for the patient, usually a nurse within 24 hours of admission.

In your study you have tested PACE in an ICU setting. How could PACE be implemented on a wider scale and in other settings?

We tested PACE in ICU because it is where there is a lot of uncertainty for patients and families. But similar needs for good communication and psychosocial care, and the presence of uncertainty, exist across the healthcare system. PACE helps the staff to get to know the patient and family better, and helps the family and patient feel that someone is interested in them and their wishes, as well as in the purely biomedical aspects of their condition. So we believe it could be helpful in other settings, especially in hospitals but this would need testing. In ICU there are higher levels of staffing than the rest of the hospital, so it may be more difficult to train staff to ask the questions correctly, and to listen well to families and patients’ answers and wishes. There may be a need to modify the training component of PACE or the questions it asks for it to best work in other settings.

How easy will it be to implement PACE into clinical practice and what will this involve?

The implementation of any tool is important as a tool is only as good as the implementation that supports it. We deliberately kept PACE short, so it couldn’t be a tick box exercise or a check list – we wanted the staff to think about what the assessment meant and to take the time to listen to patients and families. Our research in the implementation found that in general PACE was completed within 24 to 48 hours of admission (only about half of PACEs were completed within 24 hours and the rest within 48 hours). Most people found it easy to record the family history, the family condition and the social circumstances but more difficult to ask about prior preferences that the patient might have. This is where the training and support, which needs to be ongoing, is important.

What’s next for your research? Are their plans for a Phase III study of PACE?

We want to test PACE more widely and a Phase III study is exactly the right next step. We would like to try this in several centres – at the moment PACE has been tested in one hospital. We are about to plan an expansion of the work and seek potential partners. We want to see if there are benefits of PACE but also if there are any downsides to using it. So far, we are encouraged because it appears that PACE is not only feasible but it seems to improve communication, information, the families perception of the honesty of staff, and symptom control. The next test is to evaluate this further with comparative trials. Our development and preliminary evaluation was supported by the UK National Institutes of Health Research (NIHR), and we will need to approach them or a charity to support the next phase in the work.

Fluorescently tagged polyglutamine expansions expressed in the muscles of a laboratory strain of C .elegans (Bristol N2, left) and a wild strain (DR1350, right). Image source: Gidalevitz et al, BMC Biology, 2013,

C. elegans has already proved useful for studying the cellular toxicity caused by polyglutamine and other disease-associated proteins in the fixed genetic background of a laboratory strain, and the new research extends the utility of the model by showing that numerous natural genetic modifiers of polyglutamine disease  exist in wild worm populations. Previous work has already identified specific genes and pathways that can be manipulated to modify the phenotype caused by protein destabilizing mutations, but amelioration of disease is often achieved at some other cost to the organism. The study establishes C. elegans as a genetically tractable model for identifying modifiers of protein homeostasis among natural variants shaped by selection for the overall fitness of the organism, and could lead to new therapeutic targets.

A worm which as an adult has only about 1,000 cells overall and 301 neurons may seem an unlikely model for studying human neurodegenerative disease, but the cellular pathways governing protein homeostasis are conserved across eukaryotes, and as Matt Kaeberlein from the University of Washington Medical Center, USA, explains in a commentary accompanying the publication of the research article, C. elegans has several features that have contributed to its utility as a model organism, and key aspects of proteotoxic diseases are recapitulated in transgenic worms expressing aggregation-prone proteins.

In the polyQ disease model used by Gidalavitz and Morimoto (one which was originally developed in the Morimoto lab),  a fluorescent-tagged peptide encoding a stretch of 40 glutamines is expressed from a transgene specifically in muscle cells, allowing age-associated aggregation to be monitored in vivo, while assessing toxicity through effects on muscle function and lifespan in the same animals.  In the new study, the researchers introduced the transgene (by introgressive breeding) into three wild strains of C. elegans, finding that genetic background  affected both the age of onset and extent of aggregation, and also which subsets of muscles cells are most likely to form aggregate. They also observed that modifying effects on aggregation and measures of toxicity did not always correlate, with one wild background providing significant protection against muscle paralysis in body wall and reproductive muscle without suppressing aggregation (compared to the original laboratory strain).

The existence of modifiers that can act independently on the aggregation and toxicity phenotypes was further supported by a series of 21 recombinant inbred lines generated between the laboratory strain and the wild strain that showed the greatest enhancement of aggregation, while the existence of multiple modifiers and interactions between them was indicated by transgression – some of the inbred lines had a more extreme aggregation phenotype than either parental line. Overall the results suggest the existence of different and complex modifying pathways, which will be amenable to further dissection and characterization, and may be amenable to therapeutic manipulation.

Understanding the molecular mechanics of the C₄ system has clear implications for future agriculture and food production, yet identifying the regulatory factors involved has proved elusive. In a significant step toward this goal, Shaun Bowman and colleagues in the laboratory of James Berry at the University of Buffalo, USA, have identified a new RNA binding protein that is the first such factor to be implicated in the regulation of an individual photosynthetic gene in a C₄ plant, as published in a recent study in BMC Plant Biology.

Confocal microscopy image of the leaves of the C4 plant maize stained for RLSB (top), Rubisco (middle) and PEPcase (bottom). Image source: Bowman et al, BMC Plant Biology, 2013, 13:138

Both C₃ and C₄ plants contain mesophyll cells, which contain the apparatus needed for photosynthesis. Here, carbon-dioxide assimilating enzymes fix carbon into a usable form, with each enzyme encoded by a specific pattern of gene expression. The primary workhorse of this process in C₃ plants is an enzyme called Rubisco, yet it wastefully also fixes oxygen in the process. C₄ plants overcome this wastefulness by housing Rubisco in a different cellular compartment that is surrounded by the mesophyll – known as the bundle sheath. The bundle sheath cells play host to only the second round of carbon fixation using Rubisco; the primary round of fixation instead being carried out in the mesophyll by the enzyme PEPCase, which is more efficient than Rubisco at fixing carbon.

Although inefficient, Rubisco is nevertheless ubiquitous in plants, and essential to their growth and survival. Given this, comparing the two different photosynthetic processes and identifying what regulates the shared components of their enzymatic pathways could hold the key to understanding how they both operate.

Encoding the larger of Rubisco’s two protein subunits is a chloroplast gene known as rcbL, found in both plant types. Expression of this gene in specific cell-types like the bundle sheath is tightly controlled after transcription via specific stretches of sequences within its messenger RNA (mRNA). The proteins that bind these RNA molecules influence patterns of gene expression, and it was these proteins that Bowman and colleagues sought to find.

In a multi-layered analysis using several C₄ species and the model C₃ plant Arabidopsis, the authors identified a protein called RLSB based on its ability to bind to rcbL mRNA. In both C₃ and C₄ plants, reductions in the levels of RLSB gene expression in RLSB mutant and gene-silenced plants resulted in reduced photosynthetic function, and visibly yellowed leaves.

Confocal/DIC microscopy image of a leaf of the C3 plant Arabidopsis stained for Rubisco. Image source: Bowman et al, BMC Plant Biology, 2013, 13:138

Comparison with other plant species indicates that the RLSB protein is highly conserved across many plant species, and co-localises with Rubisco in all C₃ plant cells. The localisation of this protein specifically to the bundle sheath cells in C₄ plants now adds an extra layer of evidence pointing towards a crucial regulatory role for RLSB in the expression of Rubisco in C₄ plants as well. Taken together, this work suggests that the mechanism of RLSB gene expression observed throughout C₃ plants may have been modified over evolutionary timescales to provide a more localised, specialised, and ultimately similar function in C₄ plants.

C₄ plants currently account for around a quarter of global plant primary productivity, yet few crop species utilise this more efficient form of photosynthesis. Tellingly, it is also the competitive and adaptable grass species that are mostly characterised by this system, with C₄ plants maize and sugarcane among the crop-plant exceptions. Understanding the full scope of this photosynthetic pathway could therefore pave the way toward more highly efficient varieties of non-C₄ crops, and a more efficient answer to future food production.

Alzheimer’s disease (AD) is the most common cause of age-related dementia, with a majority of cases having a sporadic, rather than familial, origin. Research suggests neuroinflammation of the brain is linked to the pathogenesis of the disease, however previous studies had not established whether this link was causal.

Kneusel and colleagues set out to investigate this association in a novel mouse model for sporadic AD using polyriboinosinic-polyribocytidilic acid (PolyI:C), a viral mimic that stimulates the immune system.

“It seems likely that chronic inflammation due to infection could be an early event in the development of AD.”
Irene Knuesel, University of Zurich

Based on the similarity between the changes in the immune-challenged mice and the development of AD in humans, this comprehensive study suggests that systemic infections represent a major risk factor for the development of AD. Knuesel and colleagues notably provide the first evidence that a pre-natal systemic immune challenge in mice results in chronic inflammation, increased levels of amyloid precursor protein, tau mislocalisation and cognitive impairments, all of which leave the brain vulnerable to pathological aging and AD. Moreover, a subsequent systemic immune challenge in adulthood further exacerbates the situation leading to neuropathological hallmarks representative of a precursor stage of early AD.

Guojun Bu, professor of neuroscience at the Mayo Clinic, USA and co-Editor-in-Chief of Molecular Neurodegeneration, was one of three judges for the Research Awards in this category, and commended the studies novel observation of “the close relationship between the immune system and the pathogenic process of AD.”

These findings provide compelling evidence for the causative role of systemic immune challenges in the development of AD-like neuropathology and also provides the scientific community with a unique tool, in the PolyI:C mouse model, to investigate the molecular mechanisms underlying early pathophysiological changes in sporadic AD.

“The relationship of inflammatory processes and neurodegeneration is frequently discussed but has not been seriously examined in animal models so far”, noted Research Award judge Amos Korczyn from the department of neurology at Tel Aviv University, Israel. “This study is very comprehensive, including both biochemical and anatomical changes in a systematic study of wild-type and transgenic animals. The work is outstanding and I expect it to be of high impact.”

You belong to the UK Juvenile Dermatomyositis Research Group (JDRG). What is the JDRG and what do you hope to achieve as a part of it?

The JDRG is a national group of paediatric rheumatologists and scientists who are interested in improving the understanding and clinical care  of patients with JDM, by sharing information on their patients, promoting research  and creating the largest cohort study of JDM patients in Europe.

What is Juvenile Dermatomyositis (JDM) and how rare is it?

Juvenile Dermatomyositis (JDM) is an autoimmune disease affecting approximately 3 children in every million per year. Muscles weakness and skin rash are the main symptoms of JDM and it affects every child differently with some children experiencing a mild form of the disease while others display a more severe disease progression.

What challenges exist in diagnosing and treating JDM?

As a rare disease, it is difficult to collect sufficient numbers of JDM patients to test new diagnostic criteria and plan randomised controlled trials (RCT) of new drugs. At present most treatments are based on expert opinion rather than trial data. On a more positive note, there was a recent large RCT of rituximab (anti CD20 monoclonal antibody) in adult and juvenile dermatomyositis, and international groups, such as the JDRG, are working on updating the diagnostic criteria originally published in 1975.

What did your study set out to investigate?

We wanted to find out if myeloid related peptide (MRP) would be an accurate biomarker for disease activity in JDM, and if so, what might be the mechanism that underlies this observation.

What most excited you about  your findings?

We were very pleased to see that serum MRP did correlate with other measures of disease activity in JDM. MRP is heat stable and easy measured by ELISA which makes it an ideal candidate for a biomarker in clinical practice.

What impact would a specific biomarker have on the day-to-day management of this condition?

One of the major challenges of JDM is trying to distinguish muscle weakness caused by active inflammation from muscle damage caused by corticosteroids or deconditioning. Having a specific biomarker for disease activity, would allows us to limit treatment escalation to those patients with real disease flares, and in this way, minimise iatrogenic harm from our treatments.

Your study defines a pathway by which macrophages ‘crosstalk’ and perpetuate inflammtatory myocytis. Do you think this is specific to JDM?

No, this is unlikely to be specific to JDM. Interestingly, muscle inflammation is also a feature of the muscular dystrophies and it is possible that MRP contributes to pathology in these disorders.

What’s next for your research?

We are carrying out a wider study to identify prognostic factors in JDM, by examining serological markers of inflammation (such as MRP), muscle biopsy results and autoantibody status, to identify those patients at risk of poor long term outcomes. In this way, we hope to target therapy to the correct patients, saving aggressive treatments for those patients who really need it.

RHD only affects the Oryctolagus cuniculus (European or common rabbit) species and its symptoms include high fever, internal bleeding and liver disease. It is caused by Rabbit Haemorrhagic Disease virus (RHDV), a single-stranded RNA virus in the Caliciviridae family belonging to the Lagovirus genus. In new research published in Veterinary Research, Ghislaine Le Gall-Reculé from the French Agency for Food, Environmental and Occupational Health and Safety, France and colleagues report a new Lagovirus strain, designated RHDV2, which is related to RHDV but with several key differences.

RHDV has proven to be highly infectious and very resistant, even persisting in frozen conditions. The worldwide prevalence of RHDV, as well as the high lethality of the disease, have resulted in intensive vaccination and epidemiological surveillance programmes. Following reports of RHD in rabbitries and among wild rabbit populations in the north-west of France, the authors used RT-PCR analysis and sandwich ELISA testing to confirm that RHDV2 was the aetiological agent responsible. The virus had killed 25 percent of RHDV-vaccinated does in one particular rabbitry.

RHDV2 differs from RHDV and the previously identified RHDVa strain, in several ways. The authors looked at complete sequences of the protein capsid genes to identify the phylogenetic relationship between the strains. They found that RHDV2, though a member of the same genus as RHDV and RHDVa, is phylogenetically distinct from these strains and forms a new genetic group.

Further molecular analysis and experimental studies carried out by the authors revealed a unique antigenic and symptomatic profile for RHDV2. Though less virulent and with lower observed mortality rates than RHDV and RHDVa, the disease resulting from RHDV2 is longer in duration and will take a chronic or subacute course more often than for RHD caused by the other viral strains.

The identification of RHDV2 and the wide range of molecular, experimental infection and epidemiological data presented by the authors represent a significant contribution to our knowledge of RHD and will likely inform epidemiological surveillance efforts in a number of territories.

Previous work from Métraux’s lab, has shown that aggressive leaf-wounding of the model cress species Arabidopsis thaliana is enough to mount a strong defence against the pathogenic fungus Botrytis cinerea – the causative agent of grey mould – by releasing protective compounds called Reactive Oxygen Species (ROS) in a process independent of the plant’s usual defensive pathways. They questioned, how much of a mechanical insult is needed to induce this protective response that primed the immune system to an attack?

Rather than be forceful with their forceps, the group instead gently rubbed individual leaves between finger and thumb, in what they term soft mechanical stress (SMS). Again, ROS were released in a rapid burst immediately following the treatment, in a coordinated process accompanied by a peak in intracellular calcium levels and activation of genes associated with the touch response. This response also translated into powerful resistance to infection.

Following inoculation of the leaves with spores of B.cinerea, SMS treatment reduced the lesion size of infection in a manner that was strongly dose-dependent – the more times the leaves were rubbed, the greater the reduction in lesion size. However, this effect was transient. After only a few hours, half of this induced resistance was lost, with full susceptibility to infection regained as little as 24 hours after treatment. Could this transient resistance be because the plants sensed the cellular damage, as seen in the Métreaux’s previous work using wounded leaves? Examination of the leaf surface under a powerful electron microscope suggests not.

Although some minor damage was observable to the tiny protrusions on the leaf surface, known as trichomes, very little overt cellular damage was observed under SMS treatment. Indeed, when the researchers replicated these experiments using a mutant Arabidopsis that lacked trichomes, no cellular damage was seen – yet resistance remained. They therefore looked a little closer.

Examining the cellular cuticle for clues, they found that the outer layer of the cell was markedly more permeable than those of untreated leaves, and that this permeability was in turn associated with the leakage of bioactive compounds onto the leaf surface. They speculate that it is these bioactive compounds that may have a key role in preventing the development, and therefore pathogenesis, of mould.

Previous work on wounding in plants has identified several signalling pathways involved in the defence and immune responses – most notably those involving salicylic acid, ethylene, jasmonate, and other hormones. This new research highlights how the wounding response is far more sensitive than previously thought, adding a new layer of complexity to the sensory world of plants and their fight against infection.

MSCs are a group of multipotent stem cells derived from the from the the embryonic germ layer called the mesoblast. They have previously been found to have the capacity to repair damaged tissue. Transplantation of MSCs is considered safe and has been tested in clinical trials for a number of different diseases with encouraging results. Adipose tissue provides an easily obtainable source of MSCs. These human adipose-derived MSCs (hAd-MSCs) secrete a large number of protective cytokines and exhibit other characteristics of MSCs including self-renewal and differentiation into multiple cell lineages.

Lead by Xiangmei Chen of the Chinese PLA General Hospital, Beijing, China, the researchers investigated whether hAd-MSC-conditioned medium (CM) could inhibit podocytic apoptosis induced by high glucose. Using mouse podocyte clone (MPC5) cells, they established an in vitro model of podocytic apoptosis and injury induced by high glucose. The MPC5 cells were then cultured with hAd-MSC-CM, harvested from patients using lipoaspiration.

Unlike the control (CM from a human embryonic lung cell line), hAd-MSC-CM reduced podocytic apoptosis induced by high glucose in a dose-dependent manner, downregulated activated caspase-3, and also prevented the downregulation and rearrangement of synaptopodin, a podocytic cytoskeletal protein. Further experiments showing a similar protective effect of recombinant human epithelial growth factor (EGF) on podocytes, suggest that the beneficial effects of hAd-MSCs are mediated mainly via the secretion of soluble EGF.

These findings suggest a promising role of hAd-MSCs in future therapeutic strategies for the treatment of diabetic nephropathy.

Sørensen and colleagues conducted a cohort study looking at the association between pre-admission metformin use and mortality after ICU admission. Using the unique Danish Civil Registration Number assigned to each citizen, data was collected by individual-level linkage between population based medical registries and databases. All 52,964 adult patients admitted to a medical or surgical ICU in Northern Denmark between January 2005 and December 2011 were identified. Of these patients, 7,404 had type 2 diabetes. Prescription data for anti-diabetic medication, including metformin was collected for each patient. 1,073 were taking metformin alone and 1,335 metformin in combination with other anti-diabetic drugs. Patients were followed up from the date of ICU admission for 30 days (or death if sooner). 30-day mortality was calculated and current metformin use was compared to recent use, former use, and never use.

Current metformin users had a lower 30-day mortality compared to non-users. 30-day mortality in non-users was 25 percent, compared to 17.6 percent for those on metformin monotherapy and 17.9 percent for those on metformin in combination with other anti-diabetics. This reduced mortality persisted after adjustment for pre-admission morbidity and other potential confounders, and was only seen in patients who were currently using metformin. Mortality was not associated with recent or former metformin use. No difference in mortality was observed between those on other anti-diabetic drugs and those who did not use any anti-diabetic drugs.

The reasons for this reduced mortality are not clear. One potential explanation is that, in addition to lowering blood glucose, metformin has other effects that may be beneficial during critical illness. It has anti-inflammatory effects that may modulate the hyper-inflammatory response central to the early phase of sepsis and organ dysfunction, as well as anti-thrombotic effects that could prevent microvascular thrombosis.

Although this study suggests that ICU patients may benefit from pre-admission metformin, the safety and effect of using metformin during critical illness is unclear. Metformin is generally not recommended during hospitalization due to the potential risk of lactic acidosis in patients with severe renal, liver or heart disease, or in patients with shock or post major surgery. It is therefore frequently switched to insulin on admission to hospital. The effect observed in the study is therefore likely due to mediation of the early response to critical illness.

This study suggests that use of metformin, alone or in combination with other anti-diabetic drugs, before admission to an ICU, is associated with reduced 30-day mortality. However, more work is needed to understand and balance the potential risks of lactic acidosis with any potential benefits of metformin in critical illness.