Alzheimer's disease (AD) has been the subject of extensive investigation as to its biological underpinnings. However, this has produced little of therapeutic benefit or indeed provided any accepted biomarkers that could tailor treatment. This chapter reviews data on the main pathophysiologic processes that have been widely shown to be altered in AD, including circadian dysregulation, mitochondrial dysfunction, gut dysbiosis, and immune-glia-platelet activation. It is proposed that alterations in the gut microbiome, including gut dysbiosis and increased gut permeability drive changes in mitochondrial function that are intimately associated with significant variations in sirtuin expression. Both mitochondria-located and nucleus/cytoplasm located sirtuins can act on mitochondrial function in different cells and body systems to co-ordinate the ageing-associated changes that underpin AD. The sirtuins are therefore key aspect to a developmental model of AD that is more 'holistic' in perspective, thereby providing a framework for the detection of earlier biomarkers and more successful treatment for the heterogenous nature of AD pathoetiology.
Activation of the trptophan catabolite (TRYCAT) pathways by oxidative and nitrosative stress and proinflammatory cytokine-driven indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO) leads to the synthesis of a number of neuroregulatory TRYCATs, such as kynurenic acid and quinolinic acid. Such TRYCATs have significant impacts on neuronal functioning and survival contributing to the changes seen in Alzheimer's disease (AD), including in its association with depression as well as alterations in the reactivity of immune and glia cells. By decreasing the availability of tryptophan for serotonin synthesis, such IDO and TDO-driven TRYCATs, also decrease the availability of serotonin for N-acetylserotonin (NAS) and melatonin synthesis. The loss of NAS and melatonin has significant consequences for the etiology, course and treatment of AD, including via interactions with altered TRYCATs, but also by changing the levels of trophic support and modulating the patterning of immune activity. In this review, we look at how such interactions of the TRYCAT and melatoninergic pathways link a plethora of previously diffuse data in AD as well as the treatment implications and future research directions that such data would suggest. Keywords: Tryptophan catabolites, melatonin, N-acetylserotonin, Alzheimer's disease, inflammation, oxidative stress, nitrosative stress, treatment, glia, immunity, pineal, mitochondria, sirtuins.
There is now evidence that chronic fatigue syndrome (CFS) is accompanied by an increased translocation of endotoxins from gram-negative enterobacteria through the gut wall, as demonstrated by increased prevalences and median values for serum IgM and IgA against the endotoxins of gram-negative enterobacteria. This condition can also be described as increased gut permeability or leaky gut and indicates intestinal mucosal dysfunction (IMD). Here we report a case of a 13 year old girl with CFS who showed very high values for serum IgM against the LPS of some enterobacteria and signs of oxidative and nitrosative stress, activation of the inflammatory response system, and IgG3 subclass deficiency. Upon treatment with specific antioxidants and a "leaky gut diet", which both aim to treat increased gut permeability, and immunoglobins intravenously, the increased translocation of the LPS of gram negative enterobacteria normalized and this normalization was accompanied by a complete remission of the CFS symptoms.
This study used established biomarkers of death from ischemic stroke (IS) versus stroke survival to perform network, enrichment, and annotation analyses. Protein-protein interaction (PPI) network analysis revealed that the backbone of the highly connective network of IS death consisted of IL6, ALB, TNF, SERPINE1, VWF, VCAM1, TGFB1, and SELE. Cluster analysis revealed immune and hemostasis subnetworks, which were strongly interconnected through the major switches ALB and VWF. Enrichment analysis revealed that the PPI immune subnetwork of death due to IS was highly associated with TLR2/4, TNF, JAK-STAT, NOD, IL10, IL13, IL4, and TGF-β1/SMAD pathways. The top biological and molecular functions and pathways enriched in the hemostasis network of death due to IS were platelet degranulation and activation, the intrinsic pathway of fibrin clot formation, the urokinase-type plasminogen activator pathway, post-translational protein phosphorylation, integrin cell-surface interactions, and the proteoglycan-integrin extracellular matrix complex (ECM). Regulation Explorer analysis of transcriptional factors shows: (a) that NFKB1, RELA and SP1 were the major regulating actors of the PPI network; and (b) hsa-mir-26-5p and hsa-16-5p were the major regulating microRNA actors. In conclusion, prevention of death due to IS should consider that current IS treatments may be improved by targeting VWF, the proteoglycan-integrin-ECM complex, TGF-β1/SMAD, NF-κB/RELA and SP1.
Background: First episode psychosis (FEP), schizophrenia and affective disorders are accompanied by activation of the immune inflammatory response system (IRS). The compensatory immune-regulatory reflex system (CIRS) is a regulatory immune response that is induced by the IRS but exerts negative feedback through, for example, increased levels of anti-inflammatory cytokines such as IL-4, IL-13 and IL-10. Different phenotypes of schizophrenia may exhibit distinct IRS and CIRS immune profiles.Aims: This study aims to examine the IRS and CIRS components, including macrophagic M1, T-helper (Th)-1, Th-2, Th-17 and T-regulatory (Treg) phenotypes, in antipsychotic-naïve FEP patients before and after risperidone treatment.Methods: We included 31 antipsychotic-naïve FEP patients who had measurements of IRS and CIRS biomarkers before and after treatment with risperidone for 10 weeks, and 22 healthy controls.Results: Antipsychotic-naive FEP patients showed interrelated increments in M1, Th-1, Th-2, Th-17 and Treg phenotypes and a relatively greater IRS response (especially granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-6 and IL-12) as compared with the CIRS response (IL-4, IL-13, IL-5 and IL-10). Inflammatory markers, especially IL-6 and IL-8, were significantly correlated with negative, psychotic, affective and excitation symptom dimensions. Treatment with risperidone significantly suppressed the IRS and CIRS. Baseline levels of CIRS biomarkers, especially higher soluble tumor necrosis factor receptor-1 and IL-10 predicted clinical improvement during treatment.Discussion: Our findings indicate that FEP is characterized by robust IRS (M1 + Th-1 + Th-17) and CIRS responses, suggesting that monocytes, macrophages, Th-1, Th-2, Th-17 and Treg cells are activated. The findings indicate that a) FEP patients are prone to the detrimental effects of M1, Th-1, Th-17 and Th-2 cells, which may contribute to long-lasting abnormalities in brain circuitry; and b) in FEP, the CIRS may contribute to recovery from the acute phase of illness. Enhancing the CIRS is a new drug target to treat FEP.