Fatigue in Sjögren's Syndrome: A Search for Biomarkers and Treatment Targets

Background: Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease, where patients often suffer from fatigue. Biological pathways underlying fatigue are unknown. In this study aptamer-based SOMAscan technology is used to identify potential biomarkers and treatment targets for fatigue in pSS.Methods: SOMAscan® Assay 1.3k was performed on serum samples of healthy controls (HCs) and pSS patients characterized for interferon upregulation and fatigue. Differentially expressed proteins (DEPs) between pSS patients and HC or fatigued and non-fatigued pSS patients were validated and discriminatory capacity of markers was tested using independent technology.Results: Serum concentrations of over 1,300 proteins were compared between 63 pSS patients and 20 HCs resulting in 58 upregulated and 46 downregulated proteins. Additionally, serum concentrations of 30 interferon positive (IFNpos) and 30 interferon negative (IFNneg) pSS patients were compared resulting in 25 upregulated and 13 downregulated proteins. ELISAs were performed for several DEPs between pSS patients and HCs or IFNpos and IFNneg all showing a good correlation between protein levels measured by ELISA and relative fluorescence units (RFU) measured by the SOMAscan. Comparing 22 fatigued and 23 non-fatigued pSS patients, 16 serum proteins were differentially expressed, of which 14 were upregulated and 2 were downregulated. Top upregulated DEPs included neuroactive synaptosomal-associated protein 25 (SNAP-25), alpha-enolase (ENO1) and ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCHL1). Furthermore, the proinflammatory mediator IL36a and several complement factors were upregulated in fatigued compared to non-fatigued pSS patients. ROC analysis indicated that DEPs showed good capacity to discriminate fatigued and non-fatigued pSS patients.Conclusion: In this study we validated the use of aptamer-based proteomics and identified a novel set of proteins which were able to distinguish fatigued from non-fatigued pSS patients and identified a so-called “fatigue signature.

Genetic and Environmental Influences on Pro-Inflammatory Monocytes in Bipolar Disorder A Twin Study

Context: A monocyte pro-inflammatory state has previously been reported in bipolar disorder (BD). Objective: To determine the contribution of genetic and environmental influences on the association between monocyte pro- inflammatory state and BD. Design: A quantitative polymerase chain reaction case-control study of monocytes in bipolar twins. Determination of the influence of additive genetic, common, and unique environmental factors by structural equation modeling (ACE). Setting: Dutch academic research center. Participants: Eighteen monozygotic BD twin pairs, 23 dizygotic BD twin pairs, and 18 monozygotic and 16 dizygotic healthy twin pairs. Main Outcome Measures: Expression levels of monocytes in the previously reported coherent set of 19 genes (signature) reflecting the pro- inflammatory state. Results: The familial occurrence of the association between the monocyte pro- inflammatory gene-expression signature and BDfound in the within-trait/cross-twin correlations (twin correlations) was due to shared environmental factors (ie, both monozygotic and dizygotic ratios in twin correlations approximated 1; ACE modeling data: 94% [95% confidence interval, 53%-99%] explained by common [shared] environmental factors). Although most individual signature genes followed this pattern, there was a small subcluster of genes in which genetic influences could dominate. Conclusion: The association of the monocyte proinflammatory state with BD is primarily the result of a common shared environmental factor

TREM-1 and DAP12 expression in monocytes of patients with severe psychiatric disorders. EGR3, ATF3 and PU.1 as important transcription factors

INTRODUCTION: Immune activation is a characteristic of schizophrenia (SCZ), bipolar disorder (BD) and unipolar major depressive disorder (MDD). The triggering receptor expressed on myeloid cells 1 (TREM-1), its' adaptor molecule DAP12 and their transcription factor (TF) PU.1 are important key genes in inflammation and expressed in activated monocytes and microglia. AIM: To test: (1) if the expressions of TREM-1, DAP12 and PU.1 are increased in monocytes of patients with severe psychiatric disorders and (2) if PU.1 and the TFs ATF3 and EGR3 (which have been found as prominent increased monocyte genes in previous studies) are involved in the regulation of TREM-1 and DAP12 expression. METHODS: Using Q-PCR, we studied the gene expression of TREM-1, DAP12, PU.1, ATF3 and EGR3 in the monocytes of 73 patients with severe psychiatric disorders (27 recent onset SCZ patients, 22 BD patients and 24 MDD patients) and of 79 healthy controls (HC). Using in silico TF binding site prediction and in vivo chromatin immunoprecipitation (ChIP), we studied the actual binding of EGR3, ATF3 and PU.1 to the promoter regions of TREM-1 and DAP12. RESULTS: 1. TREM-1 gene expression was increased in the monocytes of SCZ and BD patients and tended to be increased in the monocytes of MDD patients. 2. DAP12 gene levels were neither increased in the monocytes of SCZ, BD, nor MDD patients. 3. PU.1 expression levels were increased in the monocytes of MDD patients, but not in those of SCZ and BD patients. 4. TREM-1 expression levels correlated in particular to ATF3 and EGR3 expression levels, DAP12 expression levels correlated in particular to PU.1 expression levels. 5. We found using binding site prediction and ChIP assays that the TFs EGR3 and ATF3 indeed bound to the TREM-1 promoter, PU.1 bound to both the TREM-1 and DAP12 promoter. CONCLUSION: In this study, we provide evidence that TREM-1 gene expression is significantly increased in monocytes of SCZ and BD patients and that the TREM-1 gene is a target gene of the TFs ATF3 and EGR3. In MDD patients, PU.1 gene expression was increased with a tendency for TREM-1 gene over expression. Our observations support the concept that monocytes are in a pro-inflammatory state in severe psychiatric conditions and suggest differences in monocyte inflammatory set points between SCZ, BD and MDD

Presentation_1_Immunological profiling in long COVID: overall low grade inflammation and T-lymphocyte senescence and increased monocyte activation correlating with increasing fatigue severity.pdf

BackgroundMany patients with SARS-CoV-2 infection develop long COVID with fatigue as one of the most disabling symptoms. We performed clinical and immune profiling of fatigued and non-fatigued long COVID patients and age- and sex-matched healthy controls (HCs).MethodsLong COVID symptoms were assessed using patient-reported outcome measures, including the fatigue assessment scale (FAS, scores ≥22 denote fatigue), and followed up to one year after hospital discharge. We assessed inflammation-related genes in circulating monocytes, serum levels of inflammation-regulating cytokines, and leukocyte and lymphocyte subsets, including major monocyte subsets and senescent T-lymphocytes, at 3-6 months post-discharge.ResultsWe included 37 fatigued and 36 non-fatigued long COVID patients and 42 HCs. Fatigued long COVID patients represented a more severe clinical profile than non-fatigued patients, with many concurrent symptoms (median 9 [IQR 5.0-10.0] vs 3 [1.0-5.0] symptoms, p24%). Immune abnormalities that were found in the entire group of long COVID patients were low grade inflammation (increased inflammatory gene expression in monocytes, increased serum pro-inflammatory cytokines) and signs of T-lymphocyte senescence (increased exhausted CD8+ TEMRA-lymphocytes). Immune profiles did not significantly differ between fatigued and non-fatigued long COVID groups. However, the severity of fatigue (total FAS score) significantly correlated with increases of intermediate and non-classical monocytes, upregulated gene levels of CCL2, CCL7, and SERPINB2 in monocytes, increases in serum Galectin-9, and higher CD8+ T-lymphocyte counts.ConclusionLong COVID with fatigue is associated with many concurrent and persistent symptoms lasting up to one year after hospitalization. Increased fatigue severity associated with stronger signs of monocyte activation in long COVID patients and potentially point in the direction of monocyte-endothelial interaction. These abnormalities were present against a background of immune abnormalities common to the entire group of long COVID patients.</p