Mitochondria: commanders of innate immunity and disease?

Mitochondrial dysfunction is associated with the manifestation and origin of a plethora of diseases and disorders. Whilst classically the role of these archetypical 'powerhouses' in many disease phenotypes has been attributed to their ability to regulate cell metabolism and cell death pathways, emerging data posit that mitochondria may also act as powerful initiators and masters of the innate immune response. This new paradigm complements the current mitochondrial dogma, whereby molecules endogenously present on or inside the mitochondria may act as immune regulators in response to stress or pathogens and may also be responsible for the initiation and/or manifestation of chronic inflammation observed in many diseases and disorders.     

Selected biologic markers of inflammation and activity of Crohn’s disease

Abstract

The study aimed to compare the accuracy of selected biologic markers in assessing the disease activity in patients with Crohn’s disease (CD). The analysis included serum IL-2, IL-6, IL-17, TNF-α, IFN-γ, hsCRP, peripheral CD4?+?CD25?+?FOXP3?+?regulatory T cells, as well as fecal calprotectin and lactoferrin. A group of 55 adults with CD was enrolled to the study. Disease activity was assessed using Crohn’s Disease Endoscopic Index of Severity (CDEIS), which currently represents the gold standard for the evaluation of endoscopic activity. For clinical activity scoring, the Crohn’s Disease Activity Index (CDAI) was used. Concentrations of investigated markers were estimated by means of flow cytometry and enzyme-linked immunosorbent assays, and the results were correlated with both indices. The study demonstrated that both fecal markers, i.e. calprotectin (r?=?0.827, p?<?0.001) and lactoferrin (r?=?0.704, p?<?0.001), correlate closely with CDEIS score, and might be used to evaluate the severity of CD in clinical setting. The correlation of those markers with CDAI was also significant, with r?=?0.742 for calprotectin (p?<?0.001) and r?=?0.675 for lactoferrin (p?<?0.05). As for the other investigated markers, only hsCRP (r?=?0.672, p?<?0.001) and IL-17 (r?=?0.296, p?<?0.005) correlated closely with CDEIS. The correlation of the markers with CDAI was also significant, though weaker, with r?=?0.518 for hsCRP (p?<?0.001) and r?=?0.296 for IL-17 (p?<?0.05). The study showed that IL-17, despite its vague role in the pathogenesis of CD, might be a useful marker, comparable with hsCRP, in assessing the activity of the disease.     

Experimental modeling of preclinical and clinical stages of Parkinson��s disease

Degeneration of dopaminergic (DAergic) neurons of the nigrostriatal system is the key stage in the pathogenesis of Parkinson's disease. The first symptoms of this disease are observed after degeneration of 70-80% neurons, which occurs over 20-30 years. The clinical stage of Parkinson's disease begins after this period. Late diagnostics of Parkinson's disease contributes to low efficiency of therapy for this disorder. Detailed study of the pathogenesis and development of preclinical diagnostic methods for Parkinson's disease are the urgent problems. This work was designed to develop a new experimental model of the preclinical and clinical stages of the disease. Experimental modeling was performed on C57Bl/6 mice using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). This agent is converted into the MPP(+)-neurotoxin in brain DAergic neurons. We showed that MPTP in a dose of 4 mg/kg has no effect on the nigrostriatal DAergic system. MPTP in a dose of 8-16 mg/kg produced the toxic effect only on DAergic axons, which simulates the preclinical stage of Parkinson's disease. MPTP in a dose of 20-40 mg/kg had the toxic effect on neuronal axons and bodies, which simulates the clinical stage of Parkinson's disease. The data suggest that progressive degeneration of DAergic neurons is accompanied by activation of compensatory mechanisms for functional deficiency of these cells.     

Complications of adult-onset Still’s disease and their management

Introduction: Adult-onset Still’s disease (AOSD) is a rare systemic auto-inflammatory disorder in which management and treatment have considerably progressed over the past decade. Despite wide use of interleukin (IL)-1 or IL-6 inhibitors, serious complications remain possible.

Areas covered: A comprehensive literature search in MEDLINE via Pubmed was performed to review AOSD’s severe and sometimes life-threatening complications: reactive hemophagocytic lymphohystiocytosis, coagulation disorders, fulminant hepatitis, cardiac or pulmonary complications and amyloid A amyloidosis.

Expert commentary: Early recognition and prompt management is essential to significantly decrease morbi-mortality. The key question is to determine whether the complication is related to the disease itself or related to or favored by (e.g. infection) the ongoing treatment.

For all severe AOSD-related complications, high-dose corticosteroids and supportive measures remain the first-line treatment. In case of inadequate response, combination with IL-1 or IL-6 blockers is justified. Cyclosporine A and etoposide remain of interest, especially in case of reactive hemophagocytic lymphohysitocytosis. Plasma exchange may be useful in case of thrombotic microangiopathy. In the near future, new biologic or non-biologic drugs targeting IL-18 or other cytokines or kinases could be of help.     

Accumulation and distribution of α-synuclein and ubiquitin in the CNS of Gaucher disease mouse models

Gaucher disease, a prevalent lysosomal storage disease, is caused by insufficient activity of acid β-glucosidase (GCase) and resultant glucosylceramide accumulation. Recently in Parkinson disease (PD) patients, heterozygous mutations in GCase have been associated with earlier onset and more progressive PD. To understand the pathogenic relationships between GCase variants and Parkinsonism, α-synuclein and ubiquitin distributions and levels in the brains of several mouse models containing GCase variants were evaluated by immunohistochemistry. Progressive α-synuclein and ubiquitin aggregate accumulations were observed in the cortex, hippocampus, basal ganglia, brainstem, and some cerebellar regions between 4 and 24 weeks in mice that were homozygous for GCase [D409H (9H) or V394L (4L)] variants and also had a prosaposin hypomorphic (PS-NA) transgene. In 4L/PS-NA and 9H/PS-NA mice, this was coincident with progressive neurological manifestations and brain glucosylceramide accumulation. Ultrastructural studies showed electron dense inclusion bodies in neurons and axons of 9H/PS-NA brains. α-synuclein aggregates were also observed in ventricular, brainstem, and cerebellar regions of older mice (>42-weeks) with the GCase variant (D409H/D409H) without overt neurological disease. In a chemically induced GCase deficiency, α-synuclein aggregates and glucosylceramide accumulation also occurred. These studies demonstrate a relationship between glucosylceramide accumulation and α-synuclein aggregates, and implicate glucosylceramide accumulation as risk factor for the α-synucleinopathies.     

Role of β-defensins in oral epithelial health and disease

The oral epithelium functions as a mechanical and protective barrier to resist bacterial infection. β-Defensins are a group of antimicrobial peptides mainly produced by epithelial cells of many organs including skin, lung, kidney, pancreas, uterus, eye, and nasal and oral mucosa. This review focuses on β-defensins (BDs) in oral epithelia and discusses their importance in oral epithelial health and disease. BDs exhibit antimicrobial activity against oral microbes including periodontitis-related bacteria, Candida, and papilloma virus. Alterative expression of BDs was observed in oral epithelial diseases, including oral inflammatory lesions with and without microbial infection and oral cancer. BDs may be useful in the treatment of oral infectious diseases, ulcerative lesions, and cancer. BDs play an important role in protection against oral microbes and may be used in clinical applications.     

Transgenic Drosophila models of Alzheimer’s disease and tauopathies

Alzheimer’s disease (AD) is the most common form of senile dementia. Aggregation of the amyloid-β42 peptide (Aβ42) and tau proteins are pathological hallmarks in AD brains. Accumulating evidence suggests that Aβ42 plays a central role in the pathogenesis of AD, and tau acts downstream of Aβ42 as a modulator of the disease progression. Tau pathology is also observed in frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17) and other related diseases, so called tauopathies. Although most cases are sporadic, genes associated with familial AD and FTDP-17 have been identified, which led to the development of transgenic animal models. Drosophila has been a powerful genetic model system used in many fields of biology, and recently emerges as a model for human neurodegenerative diseases. In this review, we will summarize key features of transgenic Drosophila models of AD and tauopathies and a number of insights into disease mechanisms as well as therapeutic implications gained from these models.     

Chemotherapy of Chagas’ disease: the how and the why

Current developments in experimental chemotherapy of Chagas’ disease are reviewed, in particular the demonstration that fourth-generation azole derivatives (inhibitors of sterol C14α demethylase), with particular selectivity against Trypanosoma cruzi and special pharmacokinetic properties, are capable of inducing radical parasitological cures in murine models of both acute and chronic disease. These are the first reports of parasitological cure of this disease in its chronic phase. We also discuss the relevance of etiological treatment in the clinical outcome of patients with chronic Chagas’ disease. Although previous studies have suggested an important autoimmune component in the pathogenesis of this disease, recent results obtained using highly sensitive polymerase chain reaction based detection methods and detailed immunological characterization of the inflammatory process associated with chagasic cardiomyopathy indicate a positive correlation between tissue parasitism and the severity of cardiac pathological findings. Effective antiparasitic treatment can lead to regression of the inflammatory heart lesions and fibrosis in experimental animals and to stop the progression of the disease in humans. Taken together, these findings support the notion that the presence of the parasite is a necessary and sufficient condition for chagasic cardiomyopathy and confirm the importance of specific etiological treatment in the management of chronic chagasic patients. Received: 30 March 1998 / Accepted: 6 November 1998     

Co-occurrence of Alzheimer's disease ß-amyloid and τ pathologies at synapses

Although beta-amyloid (Abeta) plaques and tau neurofibrillary tangles are hallmarks of Alzheimer's disease (AD) neuropathology, loss of synapses is considered the best correlate of cognitive decline in AD, rather than plaques or tangles. How pathological Abeta and tau aggregation relate to each other and to alterations in synapses remains unclear. Since aberrant tau phosphorylation occurs in amyloid precursor protein (APP) Swedish mutant transgenic mice, and since neurofibrillary tangles develop in triple transgenic mice harboring mutations in APP, tau and presenilin 1, we utilized these well-characterized mouse models to explore the relation between Abeta and tau pathologies. We now report that pathological accumulation of Abeta and hyperphosphorylation of tau develop concomitantly within synaptic terminals.     

The complex and central role of interferon-γ in graft-versus-host disease and graft-versus-tumor activity

Allogeneic hematopoietic cell transplantation (allo-HCT) is increasingly being performed to treat patients with hematologic malignancies. However, separating the beneficial graft-versus-tumor (GVT) or graft-versus-leukemia effects from graft-versus-host disease (GVHD) has been difficult and remains a significant challenge toward improving therapeutic efficacy and reducing toxicity of allo-HCT. GVHD is induced by donor T cells that also mediate potent anti-tumor responses. However, despite the largely shared effector mechanisms, extensive animal studies have demonstrated the potential of dissociating the GVT effect from GVHD. Also in many clinical cases, long-term remission was achieved following allo-HCT, without significant GVHD. A better mechanistic understanding of the immunopathophysiology of GVHD and GVT effects may potentially help to improve allo-HCT as well as maximize the benefit of GVT effects while minimizing GVHD. In this article, we review the role of IFN-γ in regulation of alloresponses following allo-HCT, with a focus on the mechanisms of how this cytokine may separate GVHD from GVT effects.     

Control of voluntary and reflexive saccades in Parkinson’s disease

Eight patients with idiopathic Parkinson’s disease (PD) were compared with a group of age-matched controls on both reflexive saccade and antisaccade tasks. While reflexive, visually guided saccades led to equivalent performance in both groups, PD patients were slower, made more errors, and showed reduced gain on antisaccades (AS). This is consistent with previous results showing that PD patients have no difficulty with reflexive saccades but show deficiencies in a number of voluntary saccade paradigms. Moreover, visual information in the form of landmarks improves AS performance more for PD patients than controls, a finding analogous to results seen with other motor acts such as target-directed pointing. Results are discussed in terms of a two-process model of attention and eye movements. Received: 13 October 1998 / Accepted: 11 May 1999     

Suspension culture of Marek’s disease virus and evaluation of its immunological effects

Marek’s disease virus (MDV) is a cell-associated α-herpesvirus of chickens. It is difficult to grow MDV in suspension culture. Therefore, MDV vaccines are currently produced using adherent primary chicken embryo fibroblasts, and on a large scale this is labour-intensive and costly. In this study, the CVI988 strain of MDV was inoculated into chicken fibroblast cell line UMNSAH/DF-1 (DF-1) cultured by microcarrier suspension for the proliferation experiment. Moreover, the effects of culture conditions, such as inoculation method, multiplicity of infection (MOI), microcarrier concentration, and pH value, on the proliferation of MDV were investigated. The results demonstrated that the maximum viral load of 64.76?±?2.64?×?10⁶ PFU/flask in a working volume of 100?ml could be obtained using synchronous cell seeding and inoculation method at an MOI of 0.02 and a microcarrier concentration of 5?g/l at pH 7.2. At the same time, the CVI988/DF-1 vaccines prepared by the microcarrier culture process and the traditional adherent cell culture process (CVI988/Rispens) were compared through bird experiments. We found a protective rate of 94.4% using the CVI988/DF-1 vaccine with specific pathogen-free chickens that was equivalent to that of the commercial vaccine CVI988/Rispens (protection rate of 94.1%). In this study, the MDV CVI988/DF-1 vaccine prepared by the microcarrier suspension culture of DF-1 cells could provide effective immune protection for specific pathogen-free chickens, providing a reference for the prevention and control of MD and further development of a large-scale bioreactor for producing the MD vaccine.     

Expression of cytokines and chemokines and microvasculature alterations of the tongue from patients with chronic Chagas’ disease

Chagas’ disease is caused by the protozoan Trypanosoma cruzi and continues to be a significant public health problem, since 10 million people are still infected in Latin America. The purpose of this study was to analyze the microvasculature alterations as well the expression of cytokines and chemokines in the tongues from patients with chronic Chagas’ disease (CC; n = 18), comparatively with a non-chagasic group (NC; n = 22). We observed several vascular alterations in the tongue of CC such as a greater vascular diameter, increased vascular wall area, high density of the blood vessels, and increased thickening of the capillary basement membrane. The expression of cytokines interferon gamma and tumor necrosis factor alpha and chemokine macrophage inflammatory protein 1α were significantly down-regulated in the tongue of CC group. These results demonstrated that, in the tongue of chagasic patients, a microvascular abnormality and immunological impairment occurs, probably due to chronic inflammation evoked by T. cruzi antigens.     

Beta-adrenergic drugs and risk of Parkinson’s disease: A systematic review and meta-analysis

BackgroundParkinson’s Disease (PD) is a neurodegenerative disorder manifested by rest tremor, rigidity, bradykinesia, and postural instability. Recent pharmaco-epidemiological studies evaluating beta-adrenergic drug use and risk of PD have reported conflicting findings.ObjectivesThis systematic review and meta-analyses evaluate the association between beta-adrenergic (agonists and antagonists) drugs’ use and PD.MethodsAn electronic literature search of eight databases was performed from inception to July 2021 to identify pharmaco-epidemiological studies (case-control and cohort) reporting the risk of PD in beta-adrenergic users compared to non-users. We used the generic inverse variance method and RevMan (5.3.5) to estimate pooled adjusted risk ratios (aRRs) of PD using a random-effects model.ResultsOf 3168 records, 15 studies (10 case-control; five cohort) with 6508,877 participants, including 87,011 PD cases, were included. In the pooled analysis (n = 10) including any beta-antagonist users, compared with non-users, the aRR for PD was 1.19 (CI: 1.05,1.35); for any beta-agonist users (n = 8) aRR for PD was 0.87 (CI: 0.78,0.97). Propranolol users had a significantly increased risk of PD (aRR:1.91; CI:1.20,3.06), whereas salbutamol use was associated with reduced risk of PD (aRR:0.95; CI:0.92,0.99). Significant heterogeneity (I² >87%) was observed, but the majority (n = 13) of the studies were of high quality, based on the JBI tool.ConclusionsBeta-antagonist use was associated with a modestly increased risk of PD, whereas beta-agonist use was associated with a modest decreased risk of PD. Future epidemiological studies should address the issues of protopathic bias and indirect association using appropriate epidemiological methods.     

Circulating levels of IL-1 family cytokines and receptors in Alzheimer’s disease: new markers of disease progression?

Background

Although the mechanisms underlying AD neurodegeneration are not fully understood, it is now recognised that inflammation could play a crucial role in the initiation and progression of AD neurodegeneration. A neuro-inflammatory network, based on the anomalous activation of microglial cells, includes the production of a number of inflammatory cytokines both locally and systemically. These may serve as diagnostic markers or therapeutic targets for AD neurodegeneration.

Methods

We have measured the levels of the inflammation-related cytokines and receptors of the IL-1 family in serum of subjects with AD, compared to mild cognitive impairment (MCI), subjective memory complaints (SMC), and normal healthy subjects (NHS). Using a custom-made multiplex ELISA array, we examined ten factors of the IL-1 family, the inflammation-related cytokines IL-1α, IL-1β, IL-18, and IL-33, the natural inhibitors IL-1Ra and IL-18BP, and the soluble receptors sIL-1R1, sIL-1R2, sIL-1R3, and sIL-1R4.

Results

The inflammatory cytokines IL-1α and IL-1β, their antagonist IL-1Ra, and their soluble receptor sIL-1R1 were increased in AD. The decoy IL-1 receptor sIL-1R2 was only increased in MCI. IL-33 and its soluble receptor sIL-1R4 were also significantly higher in AD. The soluble form of the accessory receptor for both IL-1 and IL-33 receptor complexes, sIL-1R3, was increased in SMC and even more in AD. Total IL-18 levels were unchanged, whereas the inhibitor IL-18BP was significantly reduced in MCI and SMC, and highly increased in AD. The levels of free IL-18 were significantly higher in MCI.

Conclusions

AD is characterised by a significant alteration in the circulating levels of the cytokines and receptors of the IL-1 family. The elevation of sIL-1R4 in AD is in agreement with findings in other diseases and can be considered a marker of ongoing inflammation. Increased levels of IL-1Ra, sIL-1R1, sIL-1R4, and IL-18BP distinguished AD from MCI and SMC, and from other inflammatory diseases. Importantly, sIL-1R1, sIL-1R3, sIL-1R4, and IL-18BP negatively correlated with cognitive impairment. A significant elevation of circulating sIL-1R2 and free IL-18, not present in SMC, is characteristic of MCI and disappears in AD, making them additional interesting markers for evaluating progression from MCI to AD.

     

Electrophysiology and beyond: Multiple roles of Na channel β subunits in development and disease

Voltage-gated Na⁺ channel (VGSC) β Subunits are not “auxiliary.” These multi-functional molecules not only modulate Na⁺ current (I_Na), but also function as cell adhesion molecules (CAMs)—playing roles in aggregation, migration, invasion, neurite outgrowth, and axonal fasciculation. β subunits are integral members of VGSC signaling complexes at nodes of Ranvier, axon initial segments, and cardiac intercalated disks, regulating action potential propagation through critical intermolecular and cell–cell communication events. At least in vitro, many β subunit cell adhesive functions occur both in the presence and absence of pore-forming VGSC α subunits, and in vivo β subunits are expressed in excitable as well as non-excitable cells, thus β subunits may play important functional roles on their own, in the absence of α subunits. VGSC β1 subunits are essential for life and appear to be especially important during brain development. Mutations in β subunit genes result in a variety of human neurological and cardiovascular diseases. Moreover, some cancer cells exhibit alterations in β subunit expression during metastasis. In short, these proteins, originally thought of as merely accessory to α subunits, are critical players in their own right in human health and disease. Here we discuss the role of VGSC β subunits in the nervous system.     

Disorders of lysosomal acidification—The emerging role of v-ATPase in aging and neurodegenerative disease

Autophagy and endocytosis deliver unneeded cellular materials to lysosomes for degradation. Beyond processing cellular waste, lysosomes release metabolites and ions that serve signaling and nutrient sensing roles, linking the functions of the lysosome to various pathways for intracellular metabolism and nutrient homeostasis. Each of these lysosomal behaviors is influenced by the intraluminal pH of the lysosome, which is maintained in the low acidic range by a proton pump, the vacuolar ATPase (v-ATPase). New reports implicate altered v-ATPase activity and lysosomal pH dysregulation in cellular aging, longevity, and adult-onset neurodegenerative diseases, including forms of Parkinson disease and Alzheimer disease. Genetic defects of subunits composing the v-ATPase or v-ATPase-related proteins occur in an increasingly recognized group of familial neurodegenerative diseases. Here, we review the expanding roles of the v-ATPase complex as a platform regulating lysosomal hydrolysis and cellular homeostasis. We discuss the unique vulnerability of neurons to persistent low level lysosomal dysfunction and review recent clinical and experimental studies that link dysfunction of the v-ATPase complex to neurodegenerative diseases across the age spectrum.