Cerebral White Matter Alterations Associated With Oligodendrocyte Vulnerability in Organic Acidurias: Insights in Glutaric Aciduria Type I.

The white matter is an important constituent of the central nervous system, containing axons, oligodendrocytes, and its progenitor cells, astrocytes, and microglial cells. Oligodendrocytes are central for myelin synthesis, the insulating envelope that protects axons and allows normal neural conduction. Both, oligodendrocytes and myelin, are highly vulnerable to toxic factors in many neurodevelopmental and neurodegenerative disorders associated with disturbances of myelination. Here we review the main alterations in oligodendrocytes and myelin observed in some organic acidurias/acidemias, which correspond to inherited neurometabolic disorders biochemically characterized by accumulation of potentially neurotoxic organic acids and their derivatives. The yet incompletely understood mechanisms underlying the high vulnerability of OLs and/or myelin in glutaric acidemia type I, the most prototypical cerebral organic aciduria, are particularly discussed.

Loss of miR-145 promotes remyelination and functional recovery in a model of chronic central demyelination.

Strategies for treating progressive multiple sclerosis (MS) remain limited. Here, we found that miR-145-5p is overabundant uniquely in chronic lesion tissues from secondary progressive MS patients. We induced both acute and chronic demyelination in miR-145 knockout mice to determine its contributions to remyelination failure. Following acute demyelination, no advantage to miR-145 loss could be detected. However, after chronic demyelination, animals with miR-145 loss demonstrated increased remyelination and functional recovery, coincident with altered presence of astrocytes and microglia within the corpus callosum relative to wild-type animals. This improved response in miR-145 knockout animals coincided with a pathological upregulation of miR-145-5p in wild-type animals with chronic cuprizone exposure, paralleling human chronic lesions. Furthermore, miR-145 overexpression specifically in oligodendrocytes (OLs) severely stunted differentiation and negatively impacted survival. RNAseq analysis showed altered transcriptome in these cells with downregulated major pathways involved in myelination. Our data suggest that pathological accumulation of miR-145-5p is a distinctive feature of chronic demyelination and is strongly implicated in the failure of remyelination, possibly due to the inhibition of OL differentiation together with alterations in other glial cells. This is mirrored in chronic MS lesions, and thus miR-145-5p serves as a potential relevant therapeutic target in progressive forms of MS.

A molecularly defined subpopulation of oligodendrocyte precursor cells controls the generation of myelinating oligodendrocytes during postnatal development.

Oligodendrocyte precursor cells (OPCs) are a class of glial cells that uniformly tiles the entire central nervous system (CNS). They play several key functions across the brain including the generation of oligodendrocytes and the control of myelination. Whether the functional diversity of OPCs is the result of genetically defined subpopulations or of their regulation by external factors has not been definitely established. We discovered that a subpopulation of OPCs found across the brain is defined by the expression of C1ql1, a gene previously described for its synaptic function in neurons. This subpopulation starts to appear during the first postnatal week in the mouse cortex. Ablation of C1ql1-expressing OPCs in the mouse leads to a massive lack of oligodendrocytes and myelination in many brain regions. This deficit cannot be rescued, even though some OPCs escape Sox10-driven ablation and end up partially compensating the OPC loss in the adult. Therefore, C1ql1 is a molecular marker of a functionally non-redundant subpopulation of OPCs, which controls the generation of myelinating oligodendrocytes.

2-Methoxyestradiol, an Endogenous 17ß-Estradiol Metabolite, Induces Antimitogenic and Apoptotic Actions in Oligodendroglial Precursor Cells and Triggers Endoreduplication via the p53 Pathway.

The abnormal growth of oligodendrocyte precursor cells (OPCs) significantly contributes to the progression of glioblastoma tumors. Hence, molecules that block OPC growth may be of therapeutic importance in treating gliomas. 2-Methoxyestradiol (2ME), an endogenous tubulin-interacting metabolite of estradiol, is effective against multiple proliferative disorders. Based on its anti-carcinogenic and anti-angiogenic actions, it is undergoing phase II clinical trials. We hypothesize that 2ME may prevent glioma growth by targeting OPC growth. Here, we tested this hypothesis by assessing the impact of 2ME on the growth of an OPC line, "Oli-neu", and dissected the underlying mechanism(s). Treatment with 2ME inhibited OPC growth in a concentration-dependent manner, accompanied by significant upregulation in the expression of p21 and p27, which are negative cell-cycle regulators. Moreover, treatment with 2ME altered OPC morphology from multi-arm processes to rounded cells. At concentrations of 1uM and greater, 2ME induced apoptosis, with increased expressions of caspase 3, PARP, and caspase-7 fragments, externalized phosphatidylserine staining/APOPercentage, and increased mitochondrial activity. Flow cytometry and microscopic analysis demonstrated that 2ME triggers endoreduplication in a concentration-dependent fashion. Importantly, 2ME induced cyclin E, JNK1/2, and p53 expression, as well as OPC fusion, which are key mechanisms driving endoreduplication and whole-genome duplication. Importantly, the inhibition of p53 with pifithrin-α rescued 2ME-induced endoreduplication. The pro-apoptotic and endoreduplication actions of 2ME were accompanied by the upregulation of survivin, cyclin A, Cyclin B, Cyclin D2, and ppRB. Similar growth inhibitory, apoptotic, and endoreduplication effects of 2ME were observed in CG4 cells. Taken together, our findings provide evidence that 2ME not only inhibits OPC growth and triggers apoptosis, but also activates OPCs into survival (fight or flight) mode, leading to endoreduplication. This inherent survival characteristic of OPCs may, in part, be responsible for drug resistance in gliomas, as observed for many tubulin-interacting drugs. Importantly, the fate of OPCs after 2ME treatment may depend on the cell-cycle status of individual cells. Combining tubulin-interfering molecules with drugs such as pifithrin-α that inhibit endoreduplication may help inhibit OPC/glioma growth and limit drug resistance.

Oligodendrocyte Dysfunction in Tauopathy: A Less Explored Area in Tau-Mediated Neurodegeneration.

Aggregation of the microtubule-associated protein tau (MAPT) is the hallmark pathology in a spectrum of neurodegenerative disorders collectively called tauopathies. Physiologically, tau is an inherent neuronal protein that plays an important role in the assembly of microtubules and axonal transport. However, disease-associated mutations of this protein reduce its binding to the microtubule components and promote self-aggregation, leading to formation of tangles in neurons. Tau is also expressed in oligodendrocytes, where it has significant developmental roles in oligodendrocyte maturation and myelin synthesis. Oligodendrocyte-specific tau pathology, in the form of fibrils and coiled coils, is evident in major tauopathies including progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), and Pick's disease (PiD). Multiple animal models of tauopathy expressing mutant forms of MAPT recapitulate oligodendroglial tau inclusions with potential to cause degeneration/malfunction of oligodendrocytes and affecting the neuronal myelin sheath. Till now, mechanistic studies heavily concentrated on elucidating neuronal tau pathology. Therefore, more investigations are warranted to comprehensively address tau-induced pathologies in oligodendrocytes. The present review provides the current knowledge available in the literature about the intricate relations between tau and oligodendrocytes in health and diseases.

In Vivo Monitoring of Fabp7 Expression in Transgenic Zebrafish.

In zebrafish, like in mammals, radial glial cells (RGCs) can act as neural progenitors during development and regeneration in adults. However, the heterogeneity of glia subpopulations entails the need for different specific markers of zebrafish glia. Currently, fluorescent protein expression mediated by a regulatory element from the glial fibrillary acidic protein (gfap) gene is used as a prominent glia reporter. We now expand this tool by demonstrating that a regulatory element from the mouse Fatty acid binding protein 7 (Fabp7) gene drives reliable expression in fabp7-expressing zebrafish glial cells. By using three different Fabp7 regulatory element-mediated fluorescent protein reporter strains, we reveal in double transgenic zebrafish that progenitor cells expressing fluorescent proteins driven by the Fabp7 regulatory element give rise to radial glia, oligodendrocyte progenitors, and some neuronal precursors. Furthermore, Bergmann glia represent the almost only glial population of the zebrafish cerebellum (besides a few oligodendrocytes), and the radial glia also remain in the mature cerebellum. Fabp7 regulatory element-mediated reporter protein expression in Bergmann glia progenitors suggests their origin from the ventral cerebellar proliferation zone, the ventricular zone, but not from the dorsally positioned upper rhombic lip. These new Fabp7 reporters will be valuable for functional studies during development and regeneration.

Voltage-Gated Ion Channels Are Transcriptional Targets of Sox10 during Oligodendrocyte Development.

The transcription factor Sox10 is an important determinant of oligodendroglial identity and influences oligodendroglial development and characteristics at various stages. Starting from RNA-seq data, we here show that the expression of several voltage-gated ion channels with known expression and important function in oligodendroglial cells depends upon Sox10. These include the Nav1.1, Cav2.2, Kv1.1, and Kir4.1 channels. For each of the four encoding genes, we found at least one regulatory region that is activated by Sox10 in vitro and at the same time bound by Sox10 in vivo. Cell-specific deletion of Sox10 in oligodendroglial cells furthermore led to a strong downregulation of all four ion channels in a mouse model and thus in vivo. Our study provides a clear functional link between voltage-gated ion channels and the transcriptional regulatory network in oligodendroglial cells. Furthermore, our study argues that Sox10 exerts at least some of its functions in oligodendrocyte progenitor cells, in myelinating oligodendrocytes, or throughout lineage development via these ion channels. By doing so, we present one way in which oligodendroglial development and properties can be linked to neuronal activity to ensure crosstalk between cell types during the development and function of the central nervous system.

Injectable shear-thinning hydrogels promote oligodendrocyte progenitor cell survival and remyelination in the central nervous system.

Cell therapy for the treatment of demyelinating diseases such as multiple sclerosis is hampered by poor survival of donor oligodendrocyte cell preparations, resulting in limited therapeutic outcomes. Excessive cell death leads to the release of intracellular alloantigens, which likely exacerbate local inflammation and may predispose the graft to eventual rejection. Here, we engineered innovative cell-instructive shear-thinning hydrogels (STHs) with tunable viscoelasticity and bioactivity for minimally invasive delivery of primary human oligodendrocyte progenitor cells (hOPCs) to the brain of a shiverer/rag2 mouse, a model of congenital hypomyelinating disease. The STHs enabled immobilization of prosurvival signals, including a recombinantly designed bidomain peptide and platelet-derived growth factor. Notably, STHs reduced the death rate of hOPCs significantly, promoted the production of myelinating oligodendrocytes, and enhanced myelination of the mouse brain 12 weeks post-implantation. Our results demonstrate the potential of STHs loaded with biological cues to improve cell therapies for the treatment of devastating myelopathies.

The myelin water imaging transcriptome: myelin water fraction regionally varies with oligodendrocyte-specific gene expression.

Identifying sensitive and specific measures that can quantify myelin are instrumental in characterizing microstructural changes in neurological conditions. Neuroimaging transcriptomics is emerging as a valuable technique in this regard, offering insights into the molecular basis of promising candidates for myelin quantification, such as myelin water fraction (MWF). We aimed to demonstrate the utility of neuroimaging transcriptomics by validating MWF as a myelin measure. We utilized data from a normative MWF brain atlas, comprised of 50 healthy subjects (mean age = 25 years, range = 17-42 years) scanned at 3 Tesla. Magnetic resonance imaging data included myelin water imaging to extract MWF and T1 anatomical scans for image registration and segmentation. We investigated the inter-regional distributions of gene expression data from the Allen Human Brain Atlas in conjunction with inter-regional MWF distribution patterns. Pearson correlations were used to identify genes with expression profiles mirroring MWF. The Single Cell Type Atlas from the Human Protein Atlas was leveraged to classify genes into gene sets with high cell type specificity, and a control gene set with low cell type specificity. Then, we compared the Pearson correlation coefficients for each gene set to determine if cell type-specific gene expression signatures correlate with MWF. Pearson correlation coefficients between MWF and gene expression for oligodendrocytes and adipocytes were significantly higher than for the control gene set, whereas correlations between MWF and inhibitory/excitatory neurons were significantly lower. Our approach in integrating transcriptomics with neuroimaging measures supports an emerging technique for understanding and validating MRI-derived markers such as MWF.

Selective suppression of oligodendrocyte-derived amyloid beta rescues neuronal dysfunction in Alzheimer's disease.

Reduction of amyloid beta (Aß) has been shown to be effective in treating Alzheimer's disease (AD), but the underlying assumption that neurons are the main source of pathogenic Aß is untested. Here, we challenge this prevailing belief by demonstrating that oligodendrocytes are an important source of Aß in the human brain and play a key role in promoting abnormal neuronal hyperactivity in an AD knock-in mouse model. We show that selectively suppressing oligodendrocyte Aß production improves AD brain pathology and restores neuronal function in the mouse model in vivo. Our findings suggest that targeting oligodendrocyte Aß production could be a promising therapeutic strategy for treating AD.

Single-nucleus RNA sequencing reveals glial cell type-specific responses to ischemic stroke in male rodents.

Neuroglia critically shape the brain´s response to ischemic stroke. However, their phenotypic heterogeneity impedes a holistic understanding of the cellular composition of the early ischemic lesion. Here we present a single cell resolution transcriptomics dataset of the brain´s acute response to infarction. Oligodendrocyte lineage cells and astrocytes range among the most transcriptionally perturbed populations and exhibit infarction- and subtype-specific molecular signatures. Specifically, we find infarction restricted proliferating oligodendrocyte precursor cells (OPCs), mature oligodendrocytes and reactive astrocytes, exhibiting transcriptional commonalities in response to ischemic injury. OPCs and reactive astrocytes are involved in a shared immuno-glial cross talk with stroke-specific myeloid cells. Within the perilesional zone, osteopontin positive myeloid cells accumulate in close proximity to CD44+ proliferating OPCs and reactive astrocytes. In vitro, osteopontin increases the migratory capacity of OPCs. Collectively, our study highlights molecular cross talk events which might govern the cellular composition of acutely infarcted brain tissue.

A new gatekeeper to control oligodendrogenesis.

The diversity of oligodendrocyte precursor cells (OPCs) is not well understood and is actively discussed in the field. A new study in PLOS Biology describes a novel marker for an OPC subpopulation that controls oligodendrogenesis and myelination.

Single cell transcriptomes and multiscale networks from persons with and without Alzheimer's disease.

The emergence of single nucleus RNA sequencing (snRNA-seq) offers to revolutionize the study of Alzheimer's disease (AD). Integration with complementary multiomics data such as genetics, proteomics and clinical data provides powerful opportunities to link cell subpopulations and molecular networks with a broader disease-relevant context. We report snRNA-seq profiles from superior frontal gyrus samples from 101 well characterized subjects from the Banner Brain and Body Donation Program in combination with whole genome sequences. We report findings that link common AD risk variants with CR1 expression in oligodendrocytes as well as alterations in hematological parameters. We observed an AD-associated CD83(+) microglial subtype with unique molecular networks and which is associated with immunoglobulin IgG4 production in the transverse colon. Our major observations were replicated in two additional, independent snRNA-seq data sets. These findings illustrate the power of multi-tissue molecular profiling to contextualize snRNA-seq brain transcriptomics and reveal disease biology.

Diverse Responses of Oligodendrocytes to Different FGF-Family Members: Uncoupling Structure-Function Relationship Within FGF Subfamilies.

The fifteen canonical paracrine fibroblast growth factors (FGFs) are organized in five subfamilies that interact with four FGF-receptors (FGFRs) and heparan sulfate proteoglycan (HSPG) co-receptors. Many of these FGFs are expressed in CNS regions where oligodendrocyte (OL) progenitors originate, migrate or differentiate. FGF2 (basic FGF) is considered a prototype FGF and the information about the effects of FGF signaling on OL-lineage cells has evolved largely from the study of FGF2. However, other FGFs from four subfamilies ((FGF1 (FGF1,-2), FGF4 (FGF4,-5,-6), FGF8 (FGF8,-17,-18) and FGF9 (FGF9,-16,-20)) that can interact with the isoforms of FGFRs expressed in OL-lineage cells may also play important roles. We previously reported OL-responses to FGF8 family members. Here, we investigate the effects of members of the FGF1,-4, and -9 subfamilies on proliferation and differentiation of OL progenitors (OPCs), and on cell cycle re-entry and down-regulation of myelin proteins by mature OLs. We found that while FGF2 induced all these responses strongly, FGF4,-6,-9 could do so only transiently and in the presence of exogenous HSPGs, and that FGF5,-16,-20 could not do so even in the presence of heparin or at higher concentrations. Furthermore, we noted that structurally similar FGFs within subfamilies did not always show similarities in their biological effects on OL-lineage cells. Taken together, these studies reveal that FGFs differ in the way they regulate the OL-lineage cells, emphasizes the selectivity and importance of HSPGs as FGF co-receptors in OL-lineage cells and suggests that structural similarity among FGF-subfamily members may not always predict their overlapping biological functions.

Structurally similar members of the FGF1, -4, and -9 subfamilies trigger diverse biological responses in oligodendrocyte-lineage cells and exhibit selective requirement for heparan sulfate proteoglycans as FGF co-receptors.

Reduced Expression of Oligodendrocyte Linage-Enriched Transcripts During the Endoplasmic Reticulum Stress/Integrated Stress Response.

Endoplasmic reticulum (ER) stress in oligodendrocyte (OL) linage cells contributes to several CNS pathologies including traumatic spinal cord injury (SCI) and multiple sclerosis. Therefore, primary rat OL precursor cell (OPC) transcriptomes were analyzed using RNASeq after treatments with two ER stress-inducing drugs, thapsigargin (TG) or tunicamycin (TM). Gene ontology term (GO) enrichment showed that both drugs upregulated mRNAs associated with the general stress response. The GOs related to ER stress were only enriched for TM-upregulated mRNAs, suggesting greater ER stress selectivity of TM. Both TG and TM downregulated cell cycle/cell proliferation-associated transcripts, indicating the anti-proliferative effects of ER stress. Interestingly, many OL lineage-enriched mRNAs were downregulated, including those for transcription factors that drive OL identity such as Olig2. Moreover, ER stress-associated decreases of OL-specific gene expression were found in mature OLs from mouse models of white matter pathologies including contusive SCI, toxin-induced demyelination, and Alzheimer's disease-like neurodegeneration. Taken together, the disrupted transcriptomic fingerprint of OL lineage cells may facilitate myelin degeneration and/or dysfunction when pathological ER stress persists in OL lineage cells.

The ER stress response compromises the transcriptomic identity of the OL lineage. Therefore, persistent, pathological ER stress may have a negative impact on structural and/or functional integrity of the white matter.

Navigating oligodendrocyte precursor cell aging in brain health.

Oligodendrocyte precursor cells (OPCs) comprise 5-8 % of the adult glial cell population and stand out as the most proliferative cell type in the central nervous system (CNS). OPCs are responsible for generating oligodendrocytes (OLs), the myelinating cells of the CNS. However, OPC functions decline as we age, resulting in impaired differentiation and inadequate remyelination. This review explores the cellular and molecular changes associated with OPC aging, and their impact on OPC differentiation and functionality. Furthermore, it examines the impact of OPC aging within the context of multiple sclerosis and Alzheimer's disease, both neurodegenerative conditions wherein aged OPCs exacerbate disease progression by impeding remyelination. Moreover, various pharmacological interventions targeting pathways related to senescence and differentiation are discussed as potential strategies to rejuvenate aged OPCs. Enhancing our understanding of OPC aging mechanisms holds promise for developing new therapies to improve remyelination and repair in age-related neurodegenerative disorders.

Methadone directly impairs central nervous system cells in vitro.

Methadone is a synthetic long-acting opioid that is increasingly used in the replacement therapy of opioid-addicted patients, including pregnant women. However, methadone therapy in this population poses challenges, as it induces cognitive and behavioral impairments in infants exposed to this opioid during prenatal development. In animal models, prenatal methadone exposure results in detrimental consequences to the central nervous system, such as: (i) increased neuronal apoptosis; (ii) disruption of oligodendrocyte maturation and increased apoptosis and (iii) increased microglia and astrocyte activation. However, it remains unclear whether these deleterious effects result from a direct effect of methadone on brain cells. Therefore, our goal was to uncover the impact of methadone on single brain cell types in vitro. Primary cultures of rat neurons, oligodendrocytes, microglia, and astrocytes were treated for three days with 10 µM methadone to emulate a chronic administration. Apoptotic neurons were identified by cleaved caspase-3 detection, and synaptic density was assessed by the juxtaposition of presynaptic and postsynaptic markers. Apoptosis of oligodendrocyte precursors was determined by cleaved caspase-3 detection. Oligodendrocyte myelination was assessed by immunofluorescence, while microglia and astrocyte proinflammatory activation were assessed by both immunofluorescence and RT-qPCR. Methadone treatment increased neuronal apoptosis and reduced synaptic density. Furthermore, it led to increased oligodendrocyte apoptosis and a reduction in the myelinating capacity of these cells, and promoted the proinflammatory activation of microglia and astrocytes. We showed that methadone, the most widely used drug in opioid replacement therapy for pregnant women with opioid addiction, directly impairs brain cells in vitro, highlighting the need for developing alternative therapies to address opioid addiction in this population.

N-butyl-ß-carboline-3-carboxylate (ß-CCB) systemic administration promotes remyelination in the cuprizone demyelinating model in mice.

Demyelination is generated in several nervous system illnesses. Developing strategies for effective clinical treatments requires the discovery of promyelinating drugs. Increased GABAergic signaling through γ-aminobutyric acid type A receptor (GABAAR) activation in oligodendrocytes has been proposed as a promyelinating condition. GABAAR expressed in oligodendroglia is strongly potentiated by n-butyl-ß-carboline-3-carboxylate (ß-CCB) compared to that in neurons. Here, mice were subjected to 0.3% cuprizone (CPZ) added in the food to induce central nervous system demyelination, a well-known model for multiple sclerosis. Then ß-CCB (1 mg/Kg) was systemically administered to analyze the remyelination status in white and gray matter areas. Myelin content was evaluated using Black-Gold II (BGII) staining, immunofluorescence (IF), and magnetic resonance imaging (MRI). Evidence indicates that ß-CCB treatment of CPZ-demyelinated animals promoted remyelination in several white matter structures, such as the fimbria, corpus callosum, internal capsule, and cerebellar peduncles. Moreover, using IF, it was observed that CPZ intake induced an increase in NG2+ and a decrease in CC1+ cell populations, alterations that were importantly retrieved by ß-CCB treatment. Thus, the promyelinating character of ß-CCB was confirmed in a generalized demyelination model, strengthening the idea that it has clinical potential as a therapeutic drug.

NF1+/ex42del miniswine model the cellular disruptions and behavioral presentations of NF1-associated cognitive and motor impairment.

Cognitive or motor impairment is common among individuals with neurofibromatosis type 1 (NF1), an autosomal dominant tumor-predisposition disorder. As many as 70% of children with NF1 report difficulties with spatial/working memory, attention, executive function, and fine motor movements. In contrast to the utilization of various Nf1 mouse models, here we employ an NF1+/ex42del miniswine model to evaluate the mechanisms and characteristics of these presentations, taking advantage of a large animal species more like human anatomy and physiology. The prefrontal lobe, anterior cingulate, and hippocampus from NF1+/ex42del and wild-type miniswine were examined longitudinally, revealing abnormalities in mature oligodendrocytes and astrocytes, and microglial activation over time. Imbalances in GABA: Glutamate ratios and GAD67 expression were observed in the hippocampus and motor cortex, supporting the role of disruption in inhibitory neurotransmission in NF1 cognitive impairment and motor dysfunction. Moreover, NF1+/ex42del miniswine demonstrated slower and shorter steps, indicative of a balance-preserving response commonly observed in NF1 patients, and progressive memory and learning impairments. Collectively, our findings affirm the effectiveness of NF1+/ex42del miniswine as a valuable resource for assessing cognitive and motor impairments associated with NF1, investigating the involvement of specific neural circuits and glia in these processes, and evaluating potential therapeutic interventions.

Exploring the Potential Role of Oligodendrocyte-Associated PIP4K2A in Alzheimer's Disease Complicated with Type 2 Diabetes Mellitus via Multi-Omic Analysis.

Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM) are two common diseases that affect the elderly population worldwide. The identification of common genes associated with AD and T2DM holds promise for potential biomarkers and intriguing pathogenesis of these two complicated diseases. This study utilized a comprehensive approach by integrating transcriptome data from multiple cohorts, encompassing both AD and T2DM. The analysis incorporated various data types, including blood and tissue samples as well as single-cell datasets, allowing for a detailed assessment of gene expression patterns. From the brain region-specific single-cell analysis, PIP4K2A, which encodes phosphatidylinositol-5-phosphate 4-kinase type 2 alpha, was found to be expressed mainly in oligodendrocytes compared to other cell types. Elevated levels of PIP4K2A in AD and T2DM patients' blood were found to be associated with key cellular processes such as vesicle-mediated transport, negative regulation of autophagosome assembly, and cytosolic transport. The identification of PIP4K2A's potential roles in the cellular processes of AD and T2DM offers valuable insights into the development of biomarkers for diagnosis and therapy, especially in the complication of these two diseases.