RNA surveillance via nonsense-mediated mRNA decay is crucial for longevity in daf-2/insulin/IGF-1 mutant C. elegans

Long-lived organisms often feature more stringent protein and DNA quality control. However, whether RNA quality control mechanisms, such as nonsense-mediated mRNA decay (NMD), which degrades both abnormal as well as some normal transcripts, have a role in organismal aging remains unexplored. Here we show that NMD mediates longevity in C. elegans strains with mutations in daf-2/insulin/insulin-like growth factor 1 receptor. We find that daf-2 mutants display enhanced NMD activity and reduced levels of potentially aberrant transcripts. NMD components, including smg-2/UPF1, are required to achieve the longevity of several long-lived mutants, including daf-2 mutant worms. NMD in the nervous system of the animals is particularly important for RNA quality control to promote longevity. Furthermore, we find that downregulation of yars-2/tyrosyl-tRNA synthetase, an NMD target transcript, by daf-2 mutations contributes to longevity. We propose that NMD-mediated RNA surveillance is a crucial quality control process that contributes to longevity conferred by daf-2 mutations.

Isomorphic coalescence of aster cores formed in vitro from microtubules and kinesin motors

We report fluorescence microscopy studies of the formation of aster-like structures emerging from a cellular element-based active system and a novel analysis of the aster condensation. The system consists of rhodamine labeled microtubules which are dynamically coupled by functionalized kinesin motor proteins cross-linked via streptavidin-coated quantum dots (QDs). The aster-shaped objects contain core structures. The cores are aggregates of the QD-motor protein complexes, and result from the dynamic condensation of sub-clusters that are connected to each other randomly. The structural specificity of the aster core reflects a configuration of the initial connectivity between sub-clusters. Detailed image analysis allows us to extract a novel correlation between the condensation speed and the sub-cluster separation. The size of the core is scaled down during the condensation process, following a power law dependence on the distance between sub-clusters. The exponent of the power law is close to two, as expected from a geometric model. This single exponent common to all the contractile lines implies that there exists a time regime during which an isomorphic contraction of the aster core continues during the condensation process. We analyze the observed contraction by using a model system with potential applicability in a wide range of emergent phenomena in randomly coupled active networks, which are prevalent in the cellular environment.

Inhibition of elongin C promotes longevity and protein homeostasis via HIF-1 in C. elegans

The transcription factor hypoxia‐inducible factor 1 (HIF‐1) is crucial for responses to low oxygen and promotes longevity in Caenorhabditis elegans. We previously performed a genomewide RNA interference screen and identified many genes that act as potential negative regulators of HIF‐1. Here, we functionally characterized these genes and found several novel genes that affected lifespan. The worm ortholog of elongin C, elc‐1, encodes a subunit of E3 ligase and transcription elongation factor. We found that knockdown of elc‐1 prolonged lifespan and delayed paralysis caused by impaired protein homeostasis. We further showed that elc‐1 RNA interference increased lifespan and protein homeostasis by upregulating HIF‐1. The roles of elongin C and HIF‐1 are well conserved in eukaryotes. Thus, our study may provide insights into the aging regulatory pathway consisting of elongin C and HIF‐1 in complex metazoans.

RNA helicase HEL-1 promotes longevity by specifically activating DAF-16/FOXO transcription factor signaling in Caenorhabditis elegans

The homeostatic maintenance of the genomic DNA is crucial for regulating aging processes. However, the role of RNA homeostasis in aging processes remains unknown. RNA helicases are a large family of enzymes that regulate the biogenesis and homeostasis of RNA. However, the functional significance of RNA helicases in aging has not been explored. Here, we report that a large fraction of RNA helicases regulate the lifespan of Caenorhabditis elegans. In particular, we show that a DEAD-box RNA helicase, helicase 1 (HEL-1), promotes longevity by specifically activating the DAF-16/forkhead box O (FOXO) transcription factor signaling pathway. We find that HEL-1 is required for the longevity conferred by reduced insulin/insulin-like growth factor 1 (IGF-1) signaling (IIS) and is sufficient for extending lifespan. We further show that the expression of HEL-1 in the intestine and neurons contributes to longevity. HEL-1 enhances the induction of a large fraction of DAF-16 target genes. Thus, the RNA helicase HEL-1 appears to promote longevity in response to decreased IIS as a transcription coregulator of DAF-16. Because HEL-1 and IIS are evolutionarily well conserved, a similar mechanism for longevity regulation via an RNA helicase-dependent regulation of FOXO signaling may operate in mammals, including humans.

Effects of nutritional components on aging

Nutrients including carbohydrates, proteins, lipids, vitamins, and minerals regulate various physiological processes and are essential for the survival of organisms. Reduced overall caloric intake delays aging in various organisms. However, the role of each nutritional component in the regulation of lifespan is not well established. In this review, we describe recent studies focused on the regulatory role of each type of nutrient in aging. Moreover, we will discuss how the amount or composition of each nutritional component may influence longevity or health in humans.

Towards a global system of vigilance and surveillance in unrelated donors of haematopoietic progenitor cells for transplantation

Safety of living donors is critical to the success of blood, tissue and organ transplantation. Structured and robust vigilance and surveillance systems exist as part of some national entities, but historically no global systems are in place to ensure conformity, harmonisation and the recognition of rare adverse events (AEs). The World Health Assembly has recently resolved to require AE/reaction (AE/R) reporting both nationally and globally. The World Marrow Donor Association (WMDA) is an international organisation promoting the safety of unrelated donors and progenitor cell products for use in haematopoietic progenitor cell (HPC) transplantation. To address this issue, we established a system for collecting, collating, analysing, distributing and reacting to serious adverse events and reactions (SAE/R) in unrelated HPC donors. The WMDA successfully instituted this reporting system with 203 SAE/R reported in 2011. The committee generated two rapid reports, reacting to specific SAE/R, resulting in practice changing policies. The system has a robust governance structure, formal feedback to the WMDA membership and transparent information flows to other agencies, specialist physicians and transplant programs and the general public.

Insight into the sharing of medical images: physician, other health care providers, and staff experience in a variety of medical settings

BACKGROUND

Scant knowledge exists describing health care providers' and staffs' experiences sharing imaging studies. Additional research is needed to determine the extent to which imaging studies are shared in diverse health care settings, and the extent to which provider or practice characteristics are associated with barriers to viewing external imaging studies on portable media.

OBJECTIVE

This analysis uses qualitative data to 1) examine how providers and their staff accessed outside medical imaging studies, 2) examine whether use or the desire to use imaging studies conducted at outside facilities varied by provider specialty or location (urban, suburban, and small town) and 3) delineate difficulties experienced by providers or staff as they attempted to view and use imaging studies available on portable media.

METHODS

Semi-structured interviews were conducted with 85 health care providers and medical facility staff from urban, suburban, and small town medical practices in North Carolina and Virginia. The interviews were audio recorded, transcribed, then systematically analyzed using ATLAS.ti.

RESULTS

Physicians at family and pediatric medicine practices rely primarily on written reports for medical studies other than X-rays; and thus do not report difficulties accessing outside imaging studies. Subspecialists in urban, suburban, and small towns view imaging studies through internal communication systems, internet portals, or portable media. Many subspecialists and their staff report experiencing difficulty and time delays in accessing and using imaging studies on portable media.

CONCLUSION

Subspecialists have distinct needs for viewing imaging studies that are not shared by typical primary care providers. As development and implementation of technical strategies to share medical records continue, this variation in need and use should be noted. The sharing and viewing of medical imaging studies on portable media is often inefficient and fails to meet the needs of many subspeciality physicians, and can lead to repeated imaging studies.

The anti-tumour activity of allogeneic cytokine-induced killer cells in patients who relapse after allogeneic transplant for haematological malignancies

We performed a Phase I/II clinical trial to study the feasibility, toxicity and efficacy of allogeneic cytokine-induced killer (CIK) cell expansion, and treatment for patients with haematological malignancies who relapsed after allogeneic haemopoietic SCT (allo-HSCT). Allogeneic CIK cells were successfully generated for a total of 24 patients, including those from patients' own leukapheresis products in 5 patients who had no access to further donor cells. The median CD3(+) T-cell expansion was 9.33 (1.3-38.97) fold, and CD3(+)CD56(+) natural killer (NK)-like T-cell expansion was 27.77 (2.59-438.93) fold. A total of 55 infusions were done for 16 patients who had either failed or progressed after initial response to various individualized chemotherapy regimens and donor lymphocyte infusion (DLI), at doses ranging from 10 to 200 million CD3(+) cells/kg. Response attributable to CIK cell infusion was observed in five patients. These included two with ALL, two with Hodgkin's disease (HD) and one with AML, and two of whom had a response sustained for more than 2 years. Acute GVHD occurred in three and was easily treatable. This study provides some evidence suggestive of the efficacy of allogeneic CIK cells even after failure of DLI in some cases.