Biology subjects

Zahoor, I.

Publications and source records attributed to Zahoor, I..

7 recordsLinked to original sources

bioRxiv2024

Utility of an untargeted metabolomics approach using a 2D GC-GC-MS platform to distinguish relapsing and progressive multiple sclerosis

IntroductionMultiple sclerosis (MS) is the most common inflammatory neurodegenerative disease of the central nervous system (CNS) in young adults and results in progressive neurological defects. The relapsing-remitting phenotype (RRMS) is the most common disease course in MS and may progress to the progressive form (PPMS). ObjectivesThere is a gap in knowledge regarding whether the relapsing form can be distinguished from the progressive course or healthy subjects (HS) based on an altered serum metabolite profile. In this study, we performed global untargeted metabolomics with the 2D GCxGC-MS platform to identify altered metabolites between RRMS, PPMS, and HS. MethodsWe profiled 235 metabolites in the serum of patients with RRMS (n=41), PPMS (n=31), and HS (n=91). A comparison of RRMS and HS patients revealed 22 significantly altered metabolites at p<0.05 (false discovery rate [FDR]=0.3). The PPMS and HS comparisons revealed 28 altered metabolites at p<0.05 (FDR=0.2). ResultsPathway analysis using MetaboAnalyst revealed enrichment of four metabolic pathways in both RRMS and PPMS (hypergeometric test p<0.05): 1) galactose metabolism; 2) amino sugar and nucleotide sugar metabolism; 3) phenylalanine, tyrosine, and tryptophan biosynthesis; and 4) aminoacyl-tRNA biosynthesis. The Qiagen IPA enrichment test identified the sulfatase 2 (SULF2) (p=0.0033) and integrin subunit beta 1 binding protein 1 (ITGB1BP1) (p=0.0067) genes as upstream regulators of altered metabolites in the RRMS vs. HS groups. However, in the PPMS vs. HS comparison, valine was enriched in the neurodegeneration of brain cells (p=0.05), and heptadecanoic acid, alpha-ketoisocaproic acid, and glycerol participated in inflammation in the CNS (p=0.03). ConclusionOverall, our study suggested that RRMS and PPMS may contribute metabolic fingerprints in the form of unique altered metabolites for discriminating MS disease from HS, with the potential for constructing a metabolite panel for progressive autoimmune diseases such as MS.

bioinformatics↗

bioRxiv2024

Blood-based targeted metabolipidomics reveals altered omega fatty acid-derived lipid mediators in relapsing-remitting multiple sclerosis patients

Unresolved and uncontrolled inflammation is considered a hallmark of pathogenesis in chronic inflammatory diseases like multiple sclerosis (MS), suggesting a defective resolution process. Inflammatory resolution is an active process partially mediated by endogenous metabolites of dietary polyunsaturated fatty acids (PUFA), collectively termed specialized pro-resolving lipid mediators (SPMs). Altered levels of resolution mediators have been reported in several inflammatory diseases and may partly explain impaired inflammatory resolution. Performing LC-MS/MS-based targeted lipid mediator profiling, we observed distinct changes in fatty acid metabolites in serum from 30 relapsing-remitting MS (RRMS) patients relative to 30 matched healthy subjects (HS). Robust linear regression revealed 12 altered lipid mediators after adjusting for confounders (p <0.05). Of these, 15d-PGJ2, PGE3, and LTB5 were increased in MS while PGF2a, 8,9-DiHETrE, 5,6-DiHETrE, 20-HETE, 15-HETE, 12-HETE, 12-HEPE, 14-HDoHE, and DHEA were decreased in MS compared to HS. In addition, 12,13-DiHOME and 12,13-DiHODE were positively correlated with expanded disability status scale values (EDSS). Using Partial Least Squares, we identified several lipid mediators with high VIP scores (VIP > 1: 32% - 52%) of which POEA, PGE3, DHEA, LTB5, and 12-HETE were top predictors for distinguishing between RRMS and HS (AUC =0.75) based on the XGBoost Classifier algorithm. Collectively, these findings suggest an imbalance between inflammation and resolution. Altogether, lipid mediators appear to have potential as diagnostic and prognostic biomarkers for RRMS.

biochemistry↗

bioRxiv2023

Profiling blood-based brain biomarkers and cytokines in experimental autoimmune encephalomyelitis model of multiple sclerosis using single molecule array technology

Experimental autoimmune encephalomyelitis (EAE) is a preclinical animal model widely used to study multiple sclerosis (MS). Blood-based cytokines and neural biomarkers are predictors of neurodegeneration, disease activity, and disability in patients with MS. However, understudied confounding factors cause variation in reports on EAE across animal strains/studies, limiting the utility of these biomarkers for predicting disease activity. In this study, we investigated blood- based analyte profiles, including neural markers (NFL and GFAP) and cytokines (IL-6, IL-17, IL- 12p70, IL-10, and TNF-), in two clinically distinct EAE models: relapsing-remitting (RR)-EAE and chronic-EAE. Ultrasensitive single-molecule array technology (SIMOA, Quanterix) was used to profile the analytes in blood plasma of mice at the acute, chronic, and progressive phases of disease. In both models, NFL was substantially increased during post-disease onset at the peak, chronic, and progressive phases, with pronounced increase in chronic-EAE. Leakage of GFAP into peripheral blood was also greater after disease onset in both EAE models, especially in the acute phase of chronic-EAE. Among all cytokines, only IL-10 had consistently lower levels in both EAE models throughout the course of disease. This study suggests NFL, GFAP, and IL-10 as potential translational predictors of disease activity in EAE, making them potential candidates for surrogate markers for preclinical testing of therapeutic interventions in animal models of MS.

immunology↗

bioRxiv2023

Immuno-Responsive Gene-1: A mitochondrial gene regulates pathogenic Th17 in CNS autoimmunity mouse model

Pathogenic Th17 cells play crucial roles in CNS autoimmune diseases such as multiple sclerosis (MS), but their regulation by endogenous mechanisms remains unknown. Through RNA-seq analysis of primary brain glial cells, we identified immuno-responsive gene 1 (Irg1) as one of the highly upregulated gene under inflammatory conditions. Validation in the spinal cord of animals with experimental autoimmune encephalomyelitis (EAE), an MS model, confirmed elevated Irg1 levels in myeloid, CD4, and B cells in the EAE group raising the concern if Irg1 is detrimental or protective. Irg1 knockout (KO) mice exhibited severe EAE disease, increased mononuclear cell infiltration, and increased levels of triple-positive CD4+ T cells expressing IL17a, GM-CSF, and IFN{gamma}. A lack of Irg1 in macrophages elevates Class II expression, promoting the polarization of myelin-primed CD4+ T cells into pathogenic Th17 cells via the NLRP3/IL-1{beta} axis. Adoptive transfer in Rag-1 KO and single-cell RNA sequencing highlighted the crucial role of Irg1 in shaping pathogenic Th17 cells. Moreover, bone marrow chimeras revealed that immune cells lacking Irg1 maintained pathogenic and inflammatory phenotypes, suggesting its protective role in autoimmune diseases, including MS. SignificanceImmunoresponsive gene 1 (Irg1) was identified as a significantly elevated gene under inflammatory conditions through in vitro and in vivo models. Using global knockout mice, we identified Irg1 as a protective endogenous gene that negatively regulates pathogenic Th17 cells. Single-cell RNA sequencing of infiltrating cells during EAE revealed that Irg1 knockout enhanced the expression of pathogenic Th signatures in CD4+ T cells, indicating a robust proinflammatory environment. Irg1 negatively regulates IL-1{beta} in macrophages, which is essential for the differentiation of pTh17 CD4+ T cells, potentially clarifying the exacerbation of EAE in knockout animals. Our study identified Irg1 as a negative regulator of both innate and adaptive immune responses in a CNS autoimmunity model.

immunology↗

bioRxiv2023

Pro-resolution lipid mediator maresin-1 ameliorates inflammation, promotes neuroprotection, and prevents disease progression in experimental models of multiple sclerosis

Multiple sclerosis (MS) is one of the most common inflammatory neurodegenerative diseases in young adults and causes neurological abnormalities and disability. We studied the effect of maresin 1 (MaR1) on the progression of disease in a relapsing-remitting form of experimental allergic encephalomyelitis (RR-EAE). Treatment with MaR1 in RR-EAE accelerated inflammation resolution, protected against neurological deficits, and delayed disease progression by decreasing immune cell infiltration (CD4+IL17+ and CD4+IFN{gamma}+) into the CNS. Furthermore, the administration of MaR1 increased the production of IL-10, predominantly in macrophages and CD4+ cells. However, neutralizing IL-10 with an anti-IL-10 antibody abolished the protective effect of MaR1 on RR-EAE, suggesting that IL-10 plays a role in mediating the protective effect of MaR1 on EAE. Metabolism is rapidly becoming recognized as an important factor influencing the effector function of many immune cells. Using cutting-edge metabolic assays, our study revealed that compared with vehicle treatment, MaR1 treatment effectively restored the metabolic dysregulation observed in CD4+ cells, macrophages, and microglia in the treated group. Furthermore, MaR1 treatment reversed defective efferocytosis in EAE mice, which was potentially facilitated by the induction of metabolic alterations in macrophages and microglia. MaR1 treatment also protected myelin in the EAE group and regulated the metabolism of O4+ oligodendrocytes by restoring metabolic dysregulation through improved mitochondrial function and decreased glycolysis. Overall, in a preclinical MS animal model, MaR1 treatment produced anti-inflammatory and neuroprotective effects. It also triggered metabolic reprogramming in disease-associated cell types, accelerated efferocytosis, and preserved myelination. These data support that MaR1 has potential as a novel treatment agent for MS and other autoimmune diseases. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=153 SRC="FIGDIR/small/559216v2_ufig1.gif" ALT="Figure 1"> View larger version (30K): org.highwire.dtl.DTLVardef@10b8a0aorg.highwire.dtl.DTLVardef@93bbfdorg.highwire.dtl.DTLVardef@11ae998org.highwire.dtl.DTLVardef@1de3324_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIMaR1 expedited inflammation resolution and prevented neurological impairments in RR-EAE. C_LIO_LIIL-10 plays a role in mediating the protective effect of MaR1 on EAE. C_LIO_LIMaR1 repaired CD4, macrophage, and microglia metabolic abnormalities. C_LIO_LIMaR1 therapy restored efferocytosis in EAE. C_LIO_LIMaR1 preserved myelin and improved O4+ oligodendrocyte metabolism. C_LI

neuroscience↗

bioRxiv2023

Pyruvate dehydrogenase dependent metabolic program affects oligodendrocyte maturation and remyelination

The metabolic need of the premature oligodendrocytes (Pre-OLs) and mature oligodendrocytes (OLs) are distinct. The metabolic control of oligodendrocyte maturation is not fully understood. Here we show that the terminal maturation and higher mitochondrial respiration in the oligodendrocyte is an integrated process controlled through pyruvate dehydrogenase (Pdh). Combined bioenergetics and metabolic studies show that mature oligodendrocytes show elevated TCA cycle activity than the premature oligodendrocytes. Our signaling studies show that the increased TCA cycle activity is mediated by the activation of Pdh due to inhibition of pyruvate dehydrogenases isoform-1 (Pdhk1) that phosphorylates and inhibits Pdh. Accordingly, when Pdhk1 is directly expressed in the premature oligodendrocytes, they fail to mature. While Pdh converts pyruvate into the acetyl-CoA by its oxidative decarboxylation, our study shows that Pdh also activates a unique molecular switch required for oligodendrocyte maturation by acetylating the bHLH family transcription factor Olig1. Pdh inhibition via Pdhk1 blocks the Olig1-acetylation and hence, oligodendrocyte maturation. Using the cuprizone model of demyelination, we show that Pdh is deactivated during the demyelination phase, which is reversed in the remyelination phase upon cuprizone withdrawal. In addition, Pdh activity status correlates with the Olig1-acetylation status. Hence, the Pdh metabolic node activation allows a robust mitochondrial respiration and activation of a molecular program necessary for the terminal maturation of oligodendrocytes. Our findings open a new dialogue in the developmental biology that links cellular development and metabolism. These findings have far-reaching implications for the development of therapies for a variety of demyelinating disorders including multiple sclerosis.

neuroscience↗

bioRxiv2021

Blood-based untargeted metabolomics in Relapsing-Remitting Multiple Sclerosis revealed the testable therapeutic target

Metabolic aberrations impact the pathogenesis of multiple sclerosis (MS) and possibly can provide clues for new treatment strategies. Using untargeted metabolomics, we measured serum metabolites from 35 relapsing-remitting patients and 14 healthy age-matched controls. Out of 632 known metabolites detected, 60 were significantly altered in relapsing-remitting MS (RRMS). Bioinformatics analysis identified an altered "metabotype" in RRMS patients, represented by 4 changed metabolic pathways of glycerophospholipid, citrate cycle, sphingolipid, and pyruvate metabolism. Interestingly, the common upstream metabolic pathway feeding these 4 pathways is the glycolysis pathway. Real-time bioenergetic analysis of the patient derived peripheral blood mononuclear cells, showed enhanced glycolysis, supporting the altered metabolic state of immune cells. Experimental autoimmune encephalomyelitis mice treated with the glycolytic inhibitor, 2-deoxy-D-glucose ameliorated the disease progression and inhibited the disease pathology significantly by promoting the anti-inflammatory phenotype of monocytes/macrophage in the central nervous system. Our study suggests that targeting glycolysis offers a potential target for MS.

neuroscience↗