Innovative training networks: overview of the Marie Skłodowska-Curie PhD training model.

Doctoral training has changed in recent years with most PhDs now performed in structured programmes operated by university graduate schools. These schools generally superimpose a training framework onto the traditional research project to improve the education experience of the students and to prepare them for their careers. Many graduates progress to the commercial sector, where there is demand for highly skilled employees.

Detection of DNA fragmentation in retinal apoptosis by TUNEL.

Terminal dUTP nick end labeling (TUNEL) is an invaluable technique used in the study of late-stage apoptosis. The technique is based upon detection of fragmented DNA, a well-recognized characteristic of apoptosis, usually with fluorescent markers. Here, we describe the TUNEL technique (1) employing two different detection techniques, fluorescence microscopy and fluorescence-activated cell sorting (2) which can be applied to the analysis of apoptosis in retinal tissues or retinal cell cultures, respectively.

Reactive oxygen species regulate prosurvival ERK1/2 signaling and bFGF expression in gliosis within the retina.

Purpose: Gliosis is the response of glial cells within retinal tissue to injury. It can be beneficial in the short term, but if the response is extended it can lead to scar formation, which contributes to blindness. Phosphorylation of extracellular signal regulated kinase 1/2 (ERK1/2) is considered to be a hallmark event of gliosis, but the factors involved throughout its associated signaling pathway remain poorly understood, particularly in the retina.

Norgestrel may be a potential therapy for retinal degenerations.

Retinal degenerations cover a broad spectrum of diseases, retinitis pigmentosa being the most common inherited retinal degeneration. It remains an untreatable disorder, partly owing to its genetic complexity and variability. Gene therapies, stem cell transplantation and administration of slow release growth factors are some of the treatments currently under development for the treatment of this disease.

Preventing retinal apoptosis--is there a common therapeutic theme?

There is an urgent need for therapies for retinal diseases; retinitis pigmentosa sufferers have no treatment options available and those targeted at other retinopathies have shown limited effectiveness. The process of programmed cell death or apoptosis although complex, remains a possible target for the treatment of retinal diseases. Having identified apoptosis in the vertebrate retina in populations of immature neurons as an essential part of development it was proposed that re-activation of these developmental cell death pathways might provide insight into the death mechanisms operating in retinal diseases.

Enhancing survival of photoreceptor cells in vivo using the synthetic progestin Norgestrel.

Retinal degenerations such as Retinitis Pigmentosa remain difficult to treat given the diverse array of genes responsible for their aetiology. Rather than concentrate on specific genes, our focus is on identifying therapeutic avenues for the treatment of retinal disease that target general survival mechanisms or pathways. Norgestrel is a synthetic progestin commonly used in hormonal contraception.

A novel free radical scavenger rescues retinal cells in vivo.

The benzopyran BP (3,4-dihydro-6-hydroxy-7-methoxy-2,2-dimethyl-1(2H)-benzopyran) is a free radical scavenger that is structurally similar to alpha-tocopherol and has provided neuro-protection in a number of disease models where oxidative stress is a causative factor. A novel derivative of BP with improved lipid solubility, which we have designated BP3, was synthesized and its neuro-protective efficacy subsequently analyzed in three mouse models of retinal disease in vivo. In the acute light damage model, balb/c mice received a single intra-peritoneal injection (200 mg/kg) of BP3 one hour prior to phototoxicity, reducing photoreceptor degeneration for up to 48 h post insult.

Differential roles of ERK1/2 and JNK in retinal development and degeneration.

Programmed cell death is well established as a key factor in the development of the vertebrate nervous system of which the retina is a unique sensory component. However, it is of utmost importance for the survival of post-mitotic tissues such as the retina that the execution of the cell death program is kept under stringent control once development is complete. This is exemplified by the many retinal dystrophies where aberrant apoptosis results in loss of distinct cell layers in the mature retina and often culminates in blindness.

Rosiglitazone acts as a neuroprotectant in retinal cells via up-regulation of sestrin-1 and SOD-2.

Rosiglitazone is a member of the thiazolidinedione family of synthetic peroxisome proliferator-activated receptor (PPAR) agonists. It is a selective ligand of the PPARgamma subtype and functions by regulating the transcription of insulin-responsive genes. A screen of FDA-approved compounds identified rosiglitazone as a novel anti-apoptotic agent in retinal cells both in vitro and in vivo, functioning as a neuroprotectant in response to oxidative and calcium stress.

Morphological assessment of apoptosis.

Apoptosis is implicated in biological processes ranging from embryogenesis to ageing, from normal tissue homoeostasis to many human diseases. Apoptotic cells share a number of common features such as cell shrinkage, membrane blebbing, chromatin cleavage, nuclear condensation and formation of pyknotic bodies of condensed chromatin. In the final stages of apoptosis these pyknotic or apoptotic bodies are rapidly engulfed by neighbouring cells.

Bim expression indicates the pathway to retinal cell death in development and degeneration.

Programmed cell death (PCD) during development of the mouse retina involves activation of the mitochondrial pathway. Previous work has shown that the multidomain Bcl-2 family proteins Bax and Bak are fundamentally involved in this process. To induce mitochondrial membrane permeabilization, Bax and Bak require that prosurvival members of the family be inactivated by binding of "BH3-only" members.

Induction of BIM(EL) following growth factor withdrawal is a key event in caspase-dependent apoptosis of 661W photoreceptor cells.

Apoptosis of photoreceptor cells in the early postnatal period is a normal feature of mammalian retinal development. The role of mitochondria and caspases in the process has been well established; however, the identification of key apoptotic mediators still remains elusive. Here we report that BIM(EL), a pro-apoptotic BCL-2 family member, may be one such molecule.

Decreased expression of pro-apoptotic Bcl-2 family members during retinal development and differential sensitivity to cell death.

Apoptosis plays a crucial role in the sculpture of the mammalian retina during development. However, once the retina is fully differentiated, the emphasis must shift towards survival and mechanisms have to be put in place to prevent inappropriate cell death. In this study, we identify a potential control point at the level of mitochondrial permeability.

Activation of multiple pathways during photoreceptor apoptosis in the rd mouse.

Purpose: The primary purpose of this study was to characterize photoreceptor apoptosis in the rd mouse. Given that apoptosis is the final common pathway in many cases of retinal degeneration, the ability to retard or even arrest this process may ameliorate retinal disorders such as retinitis pigmentosa (RP). The absence of any recognized therapy emphasizes the fact that a detailed knowledge of the molecular events involved is necessary to identify rational targets for therapeutic intervention.

Apoptosis: a potential therapeutic target for retinal degenerations.

Many retinal degenerations both inherited and induced are characterized by a loss of vision that is associated with death of photoreceptors. Inherited retinal diseases, which include Retinitis Pigmentosa (RP), form the largest single cause of blindness in the developed world. The genetics of RP is complex and approximately 48 genes have been implicated in the pathology of this disorder, in addition to the numerous mutations that exist within each gene (e.

Caspase-independent photoreceptor apoptosis in mouse models of retinal degeneration.

Apoptosis is the mode of cell death in retinitis pigmentosa, a group of retinal degenerative disorders primarily affecting rod photoreceptors. Although caspases have been demonstrated to play a central role in many incidences of apoptosis, accumulating evidence suggests that they may not be required for all forms of apoptotic cell death. The present study examined the mechanism of cell death in two in vivo models of photoreceptor apoptosis: the retinal degeneration (rd) mouse, a naturally occurring mutant model, and N-methyl-N-nitrosourea-induced retinal degeneration.