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Cader, M. Z.

Publications and source records attributed to Cader, M. Z..

6 recordsLinked to original sources

BNIP3L/NIX-mediated mitophagy limits Alzheimer disease pathology and preserves neuronal function

Defective mitophagy is emerging as a key contributor to Alzheimer disease (AD), but the neuronal pathways governing mitochondrial clearance and their contribution to disease progression remain poorly understood. Here, we identify BNIP3L/NIX-dependent mitophagy as a conserved neuronal quality control pathway that maintains mitochondrial fitness and constrains AD-associated proteotoxicity. Loss of BNIP3L/NIX or its C. elegans orthologue DCT-1 impaired basal and stressed-induced mitophagy, disrupted mitochondrial homeostasis, enhanced Tau and Amyloid-beta pathology and compromised neuronal network, synaptic and behavioral function across human neuronal and in vivo models. Conversely, restoring BNIP3L/NIX and DCT-1 activity improved neuronal function under proteotoxic stress in vivo, reduced disease-associated Tau phosphorylation in human neurons and markedly suppressed seeded Tau aggregation in primary mouse neurons. Together, these findings identify BNIP3L/NIX-mediated mitophagy as a mechanistic link between mitochondrial quality control, proteostasis and neuronal function, and establish its restoration as a potential strategy for counteracting AD-associated pathology.

cell biology↗

Prominent white matter related abnormalities associated with diverse molecular alterations in a mouse model of Col4a1 cerebral small vessel disease.

White matter abnormalities are a hallmark of cerebral small vessel disease (cSVD) and are closely linked to cognitive decline and dementia. However, despite their clinical importance, underlying mechanisms remain poorly understood. Collagen IV, encoded by genes COL4A1/COL4A2, is a major component of the basement membrane, a specialised extracellular matrix (ECM) structure. Mutations in these genes cause a genetic form of cSVD. We tested the hypothesis that ECM defects caused by a Col4a1 mutation lead to white matter pathology using an established mouse model of cSVD (Col4a1+/Svc). Behavioural testing with magnetic resonance diffusion tensor imaging, pathology and ultrastructural investigations of white matter were studied. The studies revealed that Col4a1+/Svc mice have cognitive impairments, reduced myelinating oligodendrocyte pools, axonal myelination defects, and altered white matter structural integrity. Proteomic analysis, of isolated white matter from Col4a1+/Svcmice, identified extensive changes to ECM composition and endoplasmic reticulum (ER) biology including ER stress induction. We also demonstrated that targeting protein folding to promote collagen secretion and reduce ER stress, increased myelinating oligodendrocytes and axon-glial integrity in Col4a1+/Svc mice. These data provide novel insight into the pathomolecular mechanisms of white matter abnormalities in cSVD and identify a modifiable pathway as a putative therapeutic target for cSVD.

neuroscience↗

A disease-associated gene desert orchestrates macrophage inflammatory responses via ETS2

Increasing global rates of autoimmune and inflammatory disease present a burgeoning threat to human health1. This is compounded by the limited efficacy of available treatments1 and high failure rates during drug development2 - underscoring an urgent need to better understand disease mechanisms. Here we show how genetics could address this challenge. By investigating an intergenic haplotype on chr21q22, independently linked to inflammatory bowel disease (IBD), ankylosing spondylitis, primary sclerosing cholangitis and Takayasus arteritis3-6, we discover that the causal gene, ETS2, is a master regulator of inflammatory responses in human macrophages and delineate how the risk haplotype increases ETS2 expression. Genes regulated by ETS2 were prominently expressed in affected tissues from chr21q22-associated diseases and more enriched for IBD GWAS hits than almost all previously described pathways. Overexpressing ETS2 in resting macrophages produced an activated effector state that phenocopied intestinal macrophages from IBD7, with upregulation of multiple drug targets including TNF and IL-23. Using a database of cellular signatures8, we identify drugs that could modulate this pathway and validate the potent anti-inflammatory activity of one class of small molecules in vitro and ex vivo. Together, this highlights the potential for common genetic associations to improve both the understanding and treatment of human disease.

immunology↗

Mathematical modelling of brain mTOR activity identifies selective vulnerability of cell types and signalling pathways

The mTOR pathway is a global regulator of protein biosynthesis and cellular homeostasis. Understanding the differences in mTOR pathway activity between cell types is important for elucidating the role of mTOR in physiological and pathophysiological processes. The non-linear structure of the pathway, with multiple feedback loops and inputs complicates the interpretation of experimental data and requires mathematical modelling. We modelled mTOR activation under healthy and disease conditions using recently published single nuclei gene expression data from the human brain. The model predicts substantial variations in mTOR pathway activity between cell types, with neurons and astrocytes being highly sensitive to insulin and neuregulins, while vascular smooth muscle cells and pericytes are highly sensitive to PDGF. Two principal negative regulators of mTOR - TSC and PTEN have prominent roles in PDGF-mediated mTOR activation in endothelial cells and oligodendrocytes. In Alzheimers Disease brain we find that insulin-mediated activitation of mTOR pathway is selectively upregulated in microglia and oligodendrocytes and downregulated in other cells. Our mathematical modelling characterises ligand sensitivity of cerebrovascular cell types and provides insights into the brain mTOR dynamics in health and disease.

systems biology↗

NOCICEPTRA: Gene and microRNA signatures and their trajectories characterizing human iPSC-derived nociceptor maturation

Nociceptors are primary afferent neurons serving the reception of acute pain but also the transit into maladaptive pain disorders. Since native human nociceptors are hardly available for mechanistic functional research, and rodent models do not necessarily mirror human pathologies in all aspects, human iPSC-derived nociceptors (iDN) offer superior advantages as a human model system. Unbiased mRNA::microRNA co-sequencing, immunofluorescence staining and qPCR validations, revealed expression trajectories as well as miRNA target spaces throughout the transition of pluripotent cells into iDNs. mRNA and miRNA candidates emerged as regulatory hubs for neurite outgrowth, synapse development and ion channel expression. The exploratory data analysis tool NOCICEPTRA is provided as a containerized platform to retrieve experimentally determined expression trajectories, and to query custom gene sets for pathway and disease enrichments. Querying NOCICEPTRA for marker genes of cortical neurogenesis revealed distinct similarities and differences for cortical and peripheral neurons. The platform provides a public domain neuroresource to exploit the entire data sets and explore miRNA and mRNA as hubs regulating human nociceptor differentiation and function.

neuroscience↗

rdrugtrajectory: An R Package for the Analysis of Drug Prescriptions in Electronic Health Care Records

Primary care electronic health care records are rich with patient and clinical information. Studying electronic health care records has resulted in marked improvements to national health care processes and patient-care decision making, and is a powerful supplementary source of data for drug discovery effort. We present the R package rdrugtrajectory, designed to yield demographic and patient-level characteristics of drug prescriptions in the UK Clinical Practice Research Datalink dataset. The package operates over Clinical Practice Research Datalink Gold clinical, referral and therapy datasets and includes features such as first drug prescriptions analysis, cohort-wide prescription information, cumulative drug prescription events, the longitudinal trajectory of drug prescriptions, and a survival analysis timeline builder to identify risks related to drug prescription switching. The rdrugtrajectory package has been made freely available via the GitHub repository.

bioinformatics↗