Biology subjects

Piehl, F.

Publications and source records attributed to Piehl, F..

9 recordsLinked to original sources

bioRxiv2026

Advancing Neurological Liquid Biopsy via Six-Base Sequencing of Cerebrospinal Fluid Cell-Free DNA

Real-time molecular insights into the human brain are crucial for understanding neurological conditions and development of soluble biomarkers but challenged by the limited access to target tissue. Here we utilize 6-base sequencing to profile DNA modifications of cell-free DNA released from neural cells into cerebrospinal fluid. This strategy provides molecular, quantitative and qualitative insights into the ongoing neurodegenerative biology, which paves the way for liquid biopsy approaches to study neurological conditions.

neuroscience↗

bioRxiv2026

Single-cell analysis suggests coordinated immune-cell redistribution between blood and cerebrospinal fluid in early multiple sclerosis

Despite immune-cell infiltration being a hallmark of multiple sclerosis (MS), the interplay between the periphery and central nervous system immune responses is still incompletely characterized. We performed single-cell transcriptomic and V(D)J sequencing of paired blood and cerebrospinal fluid (CSF) immune cells from treatment-naive relapsing-remitting women with MS and compared them to age- and sex-matched healthy controls. Across major immune lineages, we identified coordinated, compartment-specific immune alterations, with enrichment of activated and memory lymphocyte populations in the CSF and concomitant depletion of related populations in peripheral blood, suggesting their recruitment from blood to CSF. Clonally expanded CD4 memory T-cells, together with activated, expanded IgM-positive B-cells, accumulated predominantly in the CSF of people with MS compared to healthy subjects. Interestingly, tissue-primed cytotoxic populations and CXCR3-associated memory populations were depleted from the CSF of MS, implying their recruitment to the target tissue in early disease. These findings reveal coordinated, compartment-specific immune changes in early MS and provide a systems-level view of immune-cell trafficking between peripheral and central nervous system compartments.

immunology↗

bioRxiv2026

Epigenomic profiling of cerebrospinal fluid cells identifies immune regulatory alterations and implicates protocadherins in multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS), where DNA methylation may play a role by connecting genetic and environmental risk factors. We performed whole-genome DNA methylation profiling of cerebrospinal fluid (CSF) cells from relapsing-remitting MS patients and matched controls, identifying 2,710 differentially methylated positions (DMPs) and 4,330 regions (DMRs). These changes were enriched in immune signaling, adhesion and migration processes, and were accompanied by corresponding RNA expression changes. MS-associated methylation changes enriched in the cohesin chromatin regulation pathway mapped to enhancers of T helper 17 (Th17) cells, whereas in other T cell types they were mapping to bivalent enhancers and repressed chromatin. Notably, this pathway comprised multiple Protocadherin (PCDH) genes, typically expressed in neuronal cells, that displayed consistent methylation and expression changes in CSF cells. Expression of shared intracellular domain of PCDH{gamma} cluster proteins was confirmed in peripheral blood T cells by flow cytometry as well as expression of PCDH{gamma} cluster genes in memory CD4+ T cell subsets. Moreover, co-expression analysis suggests a role of PCDH genes in aryl hydrocarbon receptor (AHR) signaling. In summary, DNA methylation changes in CSF resident cells reflect dysregulated T cell activation and migration in MS and suggest a novel role of protocadherin molecules in MS pathogenesis.

immunology↗

bioRxiv2025

Anoctamin-2-specific T Cells Link Epstein-Barr Virus to Multiple Sclerosis

Multiple sclerosis (MS) occurs when the central nervous system (CNS) is damaged by misguided adaptive immune responses, likely caused by a combination of environmental factors in genetically susceptible individuals. A known prerequisite for disease is Epstein-Barr virus (EBV) infection, and previous studies have demonstrated elevated Epstein-Barr virus nuclear antigen 1 (EBNA1) antibodies which cross-react with the calcium-activated chloride channel anoctamin-2 (ANO2) in persons with MS (pwMS). ANO2-reactive antibodies have been associated with greater neuroaxonal damage in MS, although their exact effector function is still uncertain. Here, we demonstrate that ANO2 is also the target of IFN{gamma}-producing CD4+ T cells, which are more frequent in untreated and natalizumab-treated pwMS compared to control individuals. Immunisation of SJL/J mice with either ANO2 or EBNA1 elicited cross-reactive CD4+ T cell and antibody responses in vivo. Pre-immunisation of young mice with ANO2 worsened proteolipid protein (PLP)-induced experimental autoimmune encephalomyelitis (EAE), which in older mice included atypical clinical phenotype, immune infiltration into the brain and reduced survival. EAE exacerbation was recapitulated with the adoptive co-transfer of ANO2 and myelin antigen-specific CD4+ T cells, and ANO2-specific T cells alone could induce the cell death of ANO2-expressing glial cells in vitro. T cell clones with cross-reactivity to both EBNA1 and ANO2 antigens could be isolated from natalizumab-treated pwMS. Single cell sequencing of EBNA1 and ANO2-specific T cell receptors (TCR) from four pwMS revealed a significant overlap between their antigen-specific expanded TCR repertoires within donors and transcriptomic analysis showed cross-reactive T cells to have predominantly activated and cytotoxic phenotypes. In summary, we report the first mechanistic evidence that EBNA1 CD4+ T cells can target the MS-associated autoantigen ANO2, thereby establishing a link between EBV infection and development of autoimmune neuroinflammatory disease.

immunology↗

bioRxiv2023

Dilated Virchow-Robin Spaces are a Marker for Arterial Disease in Multiple Sclerosis

Virchow-Robin spaces (VRS) have been associated with neurodegeneration and neuroinflammation. However, it remains uncertain to what degree non-dilated or dilated VRS reflect specific features of neuroinflammatory pathology. Thus, we aimed at investigating the clinical relevance of VRS as imaging biomarker in multiple sclerosis (MS) and to correlate VRS to their histopathologic signature. In a cohort study comprising 205 MS patients (including a validation cohort) and 30 control subjects, we assessed the association of non-dilated and dilated VRS to clinical and magnetic resonance imaging (MRI) out-comes. Brain blocks from 6 MS patients and 3 non-MS controls were histopathologically processed to correlate VRS to their tissue substrate. The count of dilated centrum semiovale VRS was associated with increased T1 and T2 lesion volumes. There was no systematic spatial colocalization of dilated VRS with MS lesions. At tissue level, VRS mostly corresponded to arteries and were not associated with MS pathological hallmarks. Interestingly, dilated VRS in MS were associated with signs of small vessel disease. Contrary to prior beliefs, these observations suggest that VRS in MS do not associate with accumulation of immune cells. But instead, these findings indicate vascular pathology as a driver and/or consequence of neuroinflammatory pathology for this imaging feature.

neuroscience↗

bioRxiv2020

Gsta4 controls apoptosis of differentiating adult oligodendrocytes during homeostasis and remyelination via the mitochondria-associated Fas/Casp8/Bid-axis

Arrest of oligodendrocyte (OL) differentiation and remyelination following myelin damage in Multiple Sclerosis (MS) are associated with disease progression but the underlying mechanism are elusive. We show that Glutathione S-transferase 4 (Gsta4) is highly expressed during adult OL differentiation and that its loss prevents differentiation into myelinating OLs. Also, Gsta4 appeared to be a novel target for Clemastine, in clinical trial for MS. Over-expression of Gsta4 reduced the expression of Fas and activity along the mitochondria-associated Casp8/Bid-axis in adult pre-OLs from the corpus callosum, together promoting enhanced pre-OL survival during differentiation. The Gsta4-mediated input on apoptosis during adult OL differentiation was further verified in the LPC and EAE model, where Casp8 were reduced in pre-OLs with high Gsta4 expression in an immune response-independent fashion. Our results place Gsta4 as a key regulator of intrinsic mechanisms beneficial for OL differentiation and remyelination, and as a possible target for future MS therapies.

neuroscience↗

bioRxiv2020

Profiling of small non-coding RNAs across cellular and biofluid compartments: implications for multiple sclerosis immunopathology

Multiple sclerosis (MS), a chronic inflammatory disease of the central nervous system (CNS), is associated with dysregulation of microRNAs (miRNA). We here analyzed all classes of small non-coding RNAs (sncRNAs) in matching peripheral blood mononuclear cells (PBMCs), plasma, cerebrospinal fluid (CSF) cells and cell-free CSF from relapsing-remitting (RRMS, n=12 in relapse, n=11 in remission), secondary progressive (SPMS, n=6) MS patients and non-inflammatory and inflammatory neurological disease controls (NINDC, n=11; INDC, n=5). We show widespread changes in small nuclear, nucleolar, transfer RNAs and miRNAs. In CSF cells, 133/133 and 115/117 differentially expressed sncRNAs are increased in RRMS relapse compared to remission and RRMS compared to NINDC, respectively. In contrast, 65/67 differentially expressed PBMC sncRNAs are decreased in RRMS compared to NINDC. The striking contrast between periphery and CNS suggests that sncRNA-mediated mechanisms, including alternative splicing, RNA degradation and mRNA translation, regulate the transcriptome of pathogenic cells primarily in the target organ.

molecular biology↗

bioRxiv2019

On the prediction of protein abundance from RNA

BackgroundProfiling of mRNA expression is an important method to identify biomarkers but complicated by limited correlations between mRNA expression and protein abundance. We hypothesised that these correlations could be improved by mathematical models based on measuring splice variants and time delay in protein translation. MethodsWe characterised time-series of primary human naive CD4+ T cells during early T-helper type 1 differentiation with RNA-sequencing and mass-spectrometry proteomics. We then performed computational time-series analysis in this system and in two other key human and murine immune cell types. Linear mathematical mixed time-delayed splice variant models were used to predict protein abundances, and the models were validated using out-of-sample predictions. Lastly, we re-analysed RNA-Seq datasets to evaluate biomarker discovery in five T-cell associated diseases, validating the findings for multiple sclerosis (MS) and asthma. ResultsThe new models demonstrated median correlations of mRNA-to-protein abundance of 0.79-0.94, significantly out-performing models not including the usage of multiple splice variants and time-delays, as shown in cross-validation tests. Our mathematical models provided more differentially expressed proteins between patients and controls in all five diseases. Moreover, analysis of these proteins in asthma and MS supported their relevance. One marker, sCD27, was clinically validated in MS using two independent cohorts, for treatment response and prognosis. ConclusionOur splice variant and time-delay models substantially improved the prediction of protein abundance from mRNA data in three immune cell-types. The models provided valuable biomarker candidates, which were validated in clinical studies of MS and asthma. We propose that our strategy is generally applicable for biomarker discovery.

bioinformatics↗

bioRxiv2017

Polygenic Link Between Blood Lipids And Amyotrophic Lateral Sclerosis

Dyslipidemia is common among patients with amyotrophic lateral sclerosis (ALS). We aimed to test the association and causality between blood lipids and ALS, using polygenic analyses on the summary results of genome-wide association studies. Polygenic risk scores (PRS) based on low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) risk alleles were significantly associated with a higher risk of ALS. Using single nucleotide polymorphisms (SNPs) specifically associated with LDL-C and TC as the instrumental variables, statistically significant causal effects of LDL-C and TC on ALS risk were identified in Mendelian randomization analysis. No significant association was noted between PRS based on triglycerides or high-density lipoprotein cholesterol risk alleles and ALS, and the PRS based on ALS risk alleles were not associated with any studied lipids. This study supports that high levels of LDL-C and TC are risk factors for ALS, and it also suggests a causal relationship of LDL-C and TC to ALS.

genetics↗