(S)-Daipen - CAS 148369-91-9

Distinguishing self from nonself is a unique feature of the immune system. Although most self-reactive T cells are eliminated in the thymus, a few rogue cells escape the negative selection process and have the potential to mediate autoimmune disease. Over the last decade, there has been a vast improvement in our understanding of the cellular mechanisms that evolved to dampen the deleterious effects of these self-reactive T cells. In particular, T cells expressing the transcription factor FoxP3, known as regulatory T (Treg) cells, play a central role in maintaining immune homeostasis and suppressing autoimmune responses. In addition, Treg cells are endowed with the ability to suppress diverse inflammatory responses both in lymphoid and in nonlymphoid tissues. This requires Treg cells to undergo a peripheral differentiation and specialization program that results in the emergence of effector Treg (eTreg) cells that are characterized by their ability to produce high amounts of immunosuppressive molecules, including IL-10.

The co-administration of angiotensin converting enzyme inhibitors (ACEi) and angiotensin II (AngII) receptor blockers (ARB) that bind angiotensin type 1 receptors (AT1R) may protect from Alzheimer's disease (AD) better than each treatment taken alone. We tested the curative potential of the non brain-penetrant ACEi enalapril (3 mg/kg/day) administered for 3 months either alone or in combination with the brain penetrant ARB losartan (10 mg/kg/day) in aged (∼15 months) transgenic mice overexpressing a mutated form of the human amyloid-β protein precursor (AβPP, thereafter APP mice). We studied cerebrovascular function, protein levels of oxidative stress markers (superoxide dismutases SOD1, SOD2 and the NADPH oxidase subunit p67phox), amyloid-β (Aβ) pathology, astrogliosis, cholinergic innervation, AT1R and angiotensin IV receptor (AT4R) levels, together with cognitive performance. Both treatments normalized cerebrovascular reactivity and p67phox protein levels, but they did not reduce the cerebrovascular levels of SOD1.

Our brains are highly responsive to novelty. However, how novelty is processed in the brain, and what neurotransmitter systems play a role therein, remains elusive. Here, we systematically review studies on human participants that have looked at the neuromodulatory basis of novelty detection and processing. While theoretical models and studies on nonhuman animals have pointed to a role of the dopaminergic, cholinergic, noradrenergic and serotonergic systems, the human literature has focused almost exclusively on the first two. Dopamine was found to affect electrophysiological responses to novelty early in time after stimulus presentation, but evidence on its effects on later processing was found to be contradictory: While neuropharmacological studies mostly yielded null effects, gene studies did point to an important role for dopamine. Acetylcholine seems to dampen novelty signals in the medial temporal lobe, but boost them in frontal cortex.

BACKGROUND: Recently, several studies suggest that galectin-9 (Gal-9) might play a pivotal role in the pathogenesis of autoimmune diseases. However, the exact role of Gal-9 in atherosclerosis remains to be elucidated.