New Horizons for the Study of Dietary Fiber and Health: A Review.

Dietary fibre has been consumed for centuries with known health benefits, but defining dietary fibre is a real challenge. From a functional perspective, dietary fibre is described as supporting laxation, attenuating blood glucose responses and assisting with cholesterol lowering. The problem is different types of dietary fibre have different effects, and new effects are increasingly observed, such as the influence on gut microbiota.

Effect of Nrf2 activators on release of glutathione, cysteinylglycine and homocysteine by human U373 astroglial cells.

Neurons rely on the release and subsequent cleavage of GSH to cysteinylglycine (CysGly) by astrocytes in order to maintain optimal intracellular GSH levels. In neurodegenerative diseases characterised by oxidative stress, neurons need an optimal GSH supply to defend themselves against free radicals released from activated microglia and astroglia. The rate of GSH synthesis is controlled largely by the activity of γ-glutamyl cysteine ligase.

Chronic inflammation alters production and release of glutathione and related thiols in human U373 astroglial cells.

Neurons rely on glutathione (GSH) and its degradation product cysteinylglycine released by astrocytes to maintain their antioxidant defences. This is particularly important under conditions of inflammation and oxidative stress, as observed in many neurodegenerative diseases including Alzheimer's disease (AD). The effects of inflammatory activation on intracellular GSH content and the extracellular thiol profile (including cysteinylglycine and homocysteine) of astrocytes were investigated.

Activated astrocytes: a therapeutic target in Alzheimer's disease?

Astrocytes become activated in Alzheimer's disease, contributing to and reinforcing an inflammatory cascade. A large body of evidence suggests that by transforming from a basal to a reactive state, astrocytes neglect their neurosupportive functions, thus rendering neurons vulnerable to neurotoxins, including proinflammatory cytokines and reactive oxygen species. This review highlights three important astrocytic functions that may be impaired in neurodegenerative diseases such as Alzheimer's disease.

Activated astroglia during chronic inflammation in Alzheimer's disease--do they neglect their neurosupportive roles?

Alzheimer's disease (AD) is a neurodegenerative disorder, characterized histopathologically by the extracellular deposition of beta-amyloid peptide in senile plaques, as well as intracellular neurofibrillary tangles (NFT) of hyperphosphorylated tau protein, extensive neuronal loss and synaptic changes in the hippocampus and cerebral cortex. In addition, the AD brain shows chronic inflammation characterized by an abundance of reactive astrocytes and activated microglia. In the healthy brain, astrocytes provide essential services for brain homeostasis and neuronal function, including metabolic support for neurons in the form of lactate, glutamate uptake and conversion into glutamine, and synthesis of glutathione and its precursors.