C9ORF72 interaction with cofilin modulates actin dynamics in motor neurons.

Intronic hexanucleotide expansions in C9ORF72 are common in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia, but it is unknown whether loss of function, toxicity by the expanded RNA or dipeptides from non-ATG-initiated translation are responsible for the pathophysiology. We determined the interactome of C9ORF72 in motor neurons and found that C9ORF72 was present in a complex with cofilin and other actin binding proteins. Phosphorylation of cofilin was enhanced in C9ORF72-depleted motor neurons, in patient-derived lymphoblastoid cells, induced pluripotent stem cell-derived motor neurons and post-mortem brain samples from ALS patients. C9ORF72 modulates the activity of the small GTPases Arf6 and Rac1, resulting in enhanced activity of LIM-kinases 1 and 2 (LIMK1/2). This results in reduced axonal actin dynamics in C9ORF72-depleted motor neurons. Dominant negative Arf6 rescues this defect, suggesting that C9ORF72 acts as a modulator of small GTPases in a pathway that regulates axonal actin dynamics

Intestinal Epithelial Stem/Progenitor Cells Are Controlled by Mucosal Afferent Nerves

Background: The maintenance of the intestinal epithelium is of great importance for the survival of the organism. A possible nervous control of epithelial cell renewal was studied in rats and mice. Methods: Mucosal afferent nerves were stimulated by exposing the intestinal mucosa to capsaicin (1.6 mM), which stimulates intestinal external axons. Epithelial cell renewal was investigated in the jejunum by measuring intestinal thymidine kinase (TK) activity, intestinal H-3-thymidine incorporation into DNA, and the number of crypt cells labeled with BrdU. The influence of the external gut innervation was minimized by severing the periarterial nerves. Principal Findings: Luminal capsaicin increased all the studied variables, an effect nervously mediated to judge from inhibitory effects on TK activity or H-3-thymidine incorporation into DNA by exposing the mucosa to lidocaine (a local anesthetic) or by giving four different neurotransmitter receptor antagonists i.v. (muscarinic, nicotinic, neurokinin1 (NK1) or calcitonin gene related peptide (CGRP) receptors). After degeneration of the intestinal external nerves capsaicin did not increase TK activity, suggesting the involvement of an axon reflex. Intra-arterial infusion of Substance P (SP) or CGRP increased intestinal TK activity, a response abolished by muscarinic receptor blockade. Immunohistochemistry suggested presence of M3 and M5 muscarinic receptors on the intestinal stem/progenitor cells. We propose that the stem/progenitor cells are controlled by cholinergic nerves, which, in turn, are influenced by mucosal afferent neuron(s) releasing acetylcholine and/or SP and/or CGRP. In mice lacking the capsaicin receptor, thymidine incorporation into DNA and number of crypt cells labeled with BrdU was lower than in wild type animals suggesting that nerves are important also in the absence of luminal capsaicin, a conclusion also supported by the observation that atropine lowered thymidine incorporation into DNA by 60% in control rat segments. Conclusion: Enteric nerves are of importance in maintaining the intestinal epithelial barrier.Original Publication:Ove Lundgren, Mats Jodal, Madeleine Jansson, Anders T Ryberg and Lennart Svensson, Intestinal Epithelial Stem/Progenitor Cells Are Controlled by Mucosal Afferent Nerves, 2011, PLOS ONE, (6), 2, 16295.http://dx.doi.org/10.1371/journal.pone.0016295Copyright: Public Library of Science (PLoS)http://www.plos.org

C9orf72-mediated ALS and FTD: multiple pathways to disease

The discovery that repeat expansions in the C9orf72 gene are a frequent cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) has revolutionized our understanding of these diseases. Substantial headway has been made in characterizing C9orf72-mediated disease and unravelling its underlying aetiopathogenesis. Three main disease mechanisms have been proposed: loss of function of the C9orf72 protein and toxic gain of function from C9orf72 repeat RNA or from dipeptide repeat proteins produced by repeat-associated non-ATG translation. Several downstream processes across a range of cellular functions have also been implicated. In this article, we review the pathological and mechanistic features of C9orf72-associated FTD and ALS (collectively termed C9FTD/ALS), the model systems used to study these conditions, and the probable initiators of downstream disease mechanisms. We suggest that a combination of upstream mechanisms involving both loss and gain of function and downstream cellular pathways involving both cell-autonomous and non-cell-autonomous effects contributes to disease progression

Comparison of experienced burnout symptoms in specialist oncology nurses working in hospital oncology units or in hospices.

OBJECTIVE: This study aimed to clarify the differential contributions of situational and individual factors to burnout symptoms experienced by two independent groups of specialist oncology nurses working in oncology hospital units or in hospices. METHOD: The study involved a group of specialist oncology nurses working in hospital oncology units (n = 59) and a group of specialist oncology nurses working in hospices (n = 33). Participants were invited to provide demographic data, and indicate the clinical setting in which they worked and their work experience; the Italian versions of the Maslach Burnout Inventory (MBI) (a measure of burnout symptoms), the Hospital Anxiety and Depression Scale (HADS) (a measure of anxiety and depression), and the Attachment Style Questionnaire (ASQ) (a measure of relational style) were then administered. RESULTS: The two groups of nurses were well matched for age, work experience, and levels of anxiety and depression. Regarding their relational style, the two groups only differed significantly on two subscales of the ASQ (i.e. "Confidence" and "Relationships as Secondary"). The two groups significantly differed in the levels of all burnout symptoms investigated (emotional exhaustion, depersonalization, and personal achievement), with nurses working in hospital units showing higher levels of burnout symptoms. Interestingly, multivariate regression analyses showed that the institutional factor (clinical setting in which nurses worked) clearly emerged as the only factor that influenced the level of all burnout symptoms, whereas the contribution of individual factors was less significant. SIGNIFICANCE OF RESULTS: These findings help to clarify the differential contributions of institutional and individual factors to burnout symptoms in specialist oncology nurses, and corroborate the need for interventions to contain nurses' burnout symptoms

Multicenter Phase II trial of intermediate dose cisplatin and vinorelbine in inoperable non-small cell lung cancer patients.

Vinorelbine (VNB) and cisplatin (CDDP) combination regimen was found active in the treatment of advanced non-small cell lung cancer (NSCLC) patients, but significant toxicity was observed. We evaluated the activity and toxicity of this combination administered at lower doses than previously reported. From March 1992 to March 1994, 99 patients (pts) were enrolled in a multicentric Phase II study and received intravenous CDDP at 80 mg/m2 on day 1, associated with intravenous VNB at 25 mg/m2 on days 1 and 8. Cycles were repeated every 3 weeks. The reduced doses led to a consistently lower myelotoxicity (8% Grade III-IV leukopenia) in comparison to two related Phase III studies, recently published. Conversely, the incidence of neurological toxicity was superimposable. Considering all eligible patients, the overall response rate was 28.3%, and this is similar to the results commonly observed employing the most active CDDP containing regimens. In conclusion, CDDP and VNB combination chemotherapy at the schedule performed in the present study led to a reduction of hematologic toxicity, while an appreciable activity was maintained