bims-microg Biomed News
on Microglia in health and disease
Issue of 2026–04–12
twenty papers selected by
Marcus Karlstetter, Universität zu Köln



  1. Immunity. 2026 Apr 09. pii: S1074-7613(26)00118-4. [Epub ahead of print]
      Glial crosstalk surrounding amyloid-β (Aβ) plaques establishes a self-propagating inflammatory niche fueling Alzheimer's disease (AD), yet the molecular triggers remain incompletely defined. We found that the calcium-dependent enzyme peptidyl-arginine deiminase 2 (PAD2) was selectively upregulated in plaque-associated astrocytes in human AD cortex and multiple APP AD transgenic mouse models. Astrocyte-specific deletion of Padi2 in 5×FAD mice rescued learning and memory, lowered Aβ load, restrained pro-inflammatory microglial activation, and restored microglial phagocytosis. Multi-omics profiling tied these benefits to rewiring of the astrocytic proteome and the microglial transcriptome toward homeostasis. PAD2 converted astrocytic vimentin to citrullinated Cit-Vim175/184. The released Cit-vimentin drove a proinflammatory phenotype while dampening Aβ clearance in microglia-a process dependent on TLR4 signaling. Pharmacological PAD2 inhibition mimicked the genetic rescue, normalizing glial signatures and cognition. These findings identify PAD2-dependent vimentin citrullination as a key inter-glial signaling hub that worsens AD pathology and highlight PAD2 as a promising therapeutic target.
    Keywords:  Alzheimer’s disease; PAD2; TLR4; astrocyte; citrullination; glial crosstalk; microglia; neuroinflammation; vimentin
    DOI:  https://doi.org/10.1016/j.immuni.2026.03.007
  2. Brain Behav Immun. 2026 Apr 03. pii: S0889-1591(26)00324-7. [Epub ahead of print]136 106576
      Populations affected by the opioid epidemic include pregnant women and their offspring. Infants exposed to opioids in utero are at risk of developing Neonatal Opioid Withdrawal Syndrome (NOWS), a combination of acute somatic withdrawal symptoms. In adult rodents, there is evidence that opioid exposure and withdrawal alter microglia, but few studies have examined the effects of in utero exposure and neonatal withdrawal specifically on microglia. Using a mouse model of perinatal morphine exposure that encompasses the entirety of gestation and spans into the postnatal period, we measured microglial alterations during exposure and withdrawal in neonates. Microglia number was increased on postnatal day (PND)14 (during morphine exposure) and normalized by PND15 (during spontaneous withdrawal). To determine if microglia mediate withdrawal behaviors, mice were treated with PLX3397 from PND7-PND12 to deplete microglia during morphine exposure. These mice showed a reduction in somatic signs of withdrawal and thermal hyperalgesia, indicating that microglia may play a role in the production of physical withdrawal symptoms. Perinatal morphine exposure or PLX3397 treatment alone did not produce any persisting behavioral alterations, and the combination of both produced minimal effects in adults. To better understand the underlying molecular mechanisms associated with mediating withdrawal, we isolated microglia for RNA sequencing. The microglial transcriptome was markedly altered at PND14, with considerable normalization at PND15. Overall, these data suggest that microglia are implicated in the production of withdrawal symptoms induced by perinatal morphine exposure, and early-life microglial modulation has potential as a therapeutic target for treatment of these symptoms.
    Keywords:  Microglia; Morphine; Mouse; Neonatal; Opioid; Perinatal; Sequencing; Withdrawal
    DOI:  https://doi.org/10.1016/j.bbi.2026.106576
  3. Alzheimers Dement. 2026 Apr;22(4): e71337
       INTRODUCTION: Microglia have been implicated in the templated spread of tau aggregates in tauopathies through mouse studies. However, it is unclear whether these findings translate to human disease.
    METHODS: We challenged human induced pluripotent stem cell (iPSC)-derived microglia-like-cells (iMGL) with monomeric and fibrillar recombinant tau and tau purified from Alzheimer's patient brains, examining in detail the uptake, processing, release, and seeding of tau by microglia.
    RESULTS: iMGL take up tau via lipoprotein receptor-related protein 1 (LRP)1 and heparan sulfate proteoglycans, with leucine-rich repeat kinase 2 affecting LRP1 trafficking. Monomeric tau is digested effectively with minimal effects on iMGL, but recombinant or brain-derived tau fibrils induce chemokine/interferon response subtypes, alongside downregulation of homeostatic genes. Fibrillar tau is degradation-resistant, can escape into the cytoplasm, and becomes phosphorylated on two specific residues. iMGL release partially digested fibrillar tau, including in extracellular vesicles, visualized by cryo-electron microscopy, that seed aggregation in neurons.
    DISCUSSION: Our study reveals new insights into human microglial responses to tau, highlighting opportunities to limit pathogenic tau spread.
    Keywords:  LRP1; cryo‐electron microscopy; extracellular vesicle; induced pluripotent stem cells; lipoprotein receptor‐related protein 1; microglia; phospho‐proteome; tau
    DOI:  https://doi.org/10.1002/alz.71337
  4. Alzheimers Dement. 2026 Apr;22(4): e71322
       INTRODUCTION: The olfactory system is an early target in Alzheimer's disease (AD), yet regional glial pathology interactions remain poorly defined. We examined how glial activation and pathological burden differ between the olfactory cortex (OC) and olfactory bulb (OB) across disease stages.
    METHODS: Post mortem OC and OB samples from cognitively normal (CN), mild cognitive impairment, and AD cases were analyzed using immunohistochemistry and immunofluorescence for amyloid beta (Aβ), phosphorylated tau (pTau), Iba1 (microglia), GFAP (astrocyte), and apolipoprotein E (apoE).
    RESULTS: Both regions showed stage-dependent increases in Aβ and pTau, with regionally distinct glial responses. ApoE signal varied with clinical stage rather than genotype. Co-expression analyses revealed astrocyte-linked networks in the OC and microglia-linked relationships in the OB.
    DISCUSSION: Findings demonstrate spatially heterogenous glial pathology architectures in the human olfactory system, supporting its role as an early and regionally diverse site of AD vulnerability.
    Keywords:  Alzheimer's disease; astrocytes; microglia; olfactory bulb; olfactory cortex; protein aggregation
    DOI:  https://doi.org/10.1002/alz.71322
  5. Acta Neuropathol. 2026 Apr 06. pii: 37. [Epub ahead of print]151(1):
      Microglial dysfunction is a hallmark of Alzheimer's disease (AD), yet the molecular mechanisms driving these impairments remain poorly defined. Genetic studies implicate several AD-associated genes in regulating microglial activity, including SORL1, which encodes the sorting receptor SorLA. Although SorLA is highly expressed in microglia, its functional role in cellular homeostasis has remained unclear. Here, we investigated SorLA function using human brain tissue, primary microglia from rapid autopsies, and CRISPR-engineered human iPSC-derived microglia and neurons. Integrated multi-omics analyses, including single-cell RNA sequencing, lipidomics, and proteomics, together with biochemical and functional assays, revealed that SorLA deficiency induces endoplasmic reticulum (ER) stress and interferon signaling, promotes lipid droplet accumulation, and impairs phagocytic and immune functions. Protein co-complex mapping and structural modeling identified ER-associated proteins co-enriched with SorLA, including SUN2, calnexin (CANX), and multiple COPI complex components (COPA, COPB1, COPG1, ARCN1), implicating SorLA in ER proteostasis and intracellular trafficking. Notably, SORL1 deletion in iPSC-derived neurons recapitulated key phenotypes observed in microglia, including lipid droplet accumulation and SorLA-SUN2 co-immunoprecipitation, indicating that this ER-associated pathway operates across distinct brain cell types. Together, these findings identify an ER-related role for SorLA that extends beyond its established function in endocytic trafficking. Loss of SorLA triggers maladaptive stress responses, perturbs lipid handling, and compromises cellular resilience, thereby contributing to AD-relevant cellular dysfunction.
    Keywords:   SORL1/SorLA; Alzheimer’s disease; Endoplasmic reticulum stress (ER); Lipid metabolism; Microglia
    DOI:  https://doi.org/10.1007/s00401-026-03002-9
  6. Ann Neurol. 2026 Apr 07.
      The role of microglia has emerged as a critical driver of disease progression in multiple sclerosis (MS), but we lack broadly applicable monitoring tools. Here, we investigated whether hyperreflective foci (HRF), as detected by optical coherence tomography (OCT) within the inner nuclear layer (INL) of the retina, can be used as a marker for microglial pathology. We demonstrate that HRF counts are increased in persons with relapsing and progressive MS and correlate with global white and gray matter, as well as deep gray matter [18F]GE-180 uptake. ANN NEUROL 2026.
    DOI:  https://doi.org/10.1002/ana.78215
  7. J Nanobiotechnology. 2026 Apr 04.
      Neuroinflammation mediated by microglia and excessive oxidative stress are key pathological processes driving the progression of brain injuries such as intracerebral hemorrhage (ICH) and traumatic brain injury (TBI). Modulating lactate transport has emerged as a promising approach to mitigate M1 microglia polarization and alleviate neuroinflammation. Liposomal nanoparticles provide a safe and efficient platform for drug delivery. Here, we developed reactive oxygen species (ROS) responsive MiRCM nanoparticles that co-deliver monocarboxylate transporter 1 (MCT1) inhibitor AR-C155858 and a ROS-scavenging PPS core, modified with CAQK and MG1 peptides for brain injury site and microglia targeting. MiRCM nanoparticles demonstrated ROS-induced degradation and controlled drug release, effectively protecting AR-C155858 from enzymatic degradation. In vitro and in vivo experiments exhibited that MiRCM nanoparticles selectively accumulated at injured brain regions and in M1-type microglia, where they scavenged ROS, inhibited lactate efflux, suppressed M1 microglia polarization and reduced inflammatory cytokine production in ICH and TBI models. Consequently, MiRCM treatment protected neurons, reduced astrocyte activation, preserved blood-brain barrier integrity, enhanced endogenous antioxidant enzyme activities, and alleviated neurological deficits in both ICH and TBI models. RNA sequencing further confirmed downregulation of inflammatory pathways. Moreover, biosafety evaluations revealed no significant histopathological or biochemical abnormalities in major organs, indicating good biocompatibility. In summary, this study offers a new MiRCM nanoparticle that effectively modulates lactate transport and eliminates ROS to suppress microglia M1 polarization and neuroinflammation, ultimately enhancing neural protection and functional recovery after ICH and TBI.
    DOI:  https://doi.org/10.1186/s12951-026-04355-9
  8. Research (Wash D C). 2026 ;9 1163
      Background: Emerging evidence links Porphyromonas gingivalis (P.g), a keystone oral pathogen, neuroinflammation as a driver of Alzheimer's symptoms. This study aimed to investigate the molecular mechanism by which P.g triggers neuroinflammation and cognitive decline. Methods: Wild-type (WT) mice were orally gavaged with P.g for 8 weeks to evaluate cognitive function, neuronal integrity (p-Tau, hippocampal damage), and neuroinflammation. RNA sequencing analyzed brain transcriptomic, ferroptosis, and mitochondrial function after P.g induction was mainly analyzed. In vitro, the roles of NOX4/PPAR-α/PGC-1α pathway on ferroptosis, mitochondrial function, and inflammatory responses were evaluated after microglia were treated with P.g supernatant. Finally, NOX4-knockout mice were used to validate pathway specificity. Results: P.g administration in WT mice induced cognitive deficits, hippocampal neurodegeneration, p-Tau accumulation, and neuroinflammation, accompanied by dysregulated mitochondrial genes (NOX4, PPAR-α, and PGC-1α) and ferroptosis activation. P.g supernatant promoted microglial ferroptosis, mitochondrial dysfunction, and inflammatory cytokine release in vitro, which were reversed by NOX4 silencing. Mechanistically, NOX4 knockdown restored PPAR-α/PGC-1α signaling, suppressed ferroptosis, and mitigated inflammation in vitro. Critically, NOX4-knockout mice resisted P.g-induced cognitive impairment, neuronal loss, and neuroinflammatory responses in vivo. Conclusion: This study identified P.g-induced neuroinflammation and cognitive decline via microglial ferroptosis and mitochondrial dysfunction, which were regulated by the NOX4/PPAR-α/PGC-1α pathway. These findings highlight the link between oral health and brain pathology in Alzheimer's disease and propose NOX4 as a promising pharmacological target for cognitive preservation.
    DOI:  https://doi.org/10.34133/research.1163
  9. CNS Neurosci Ther. 2026 Apr;32(4): e70858
       BACKGROUND: Traumatic brain injury (TBI) triggers a cascade of secondary damage, including neuroinflammation, astrocyte activation, and disruption of the blood-brain barrier (BBB), all of which contribute to long-term neurological deficits. Astrocyte-derived exosomes have emerged as a promising therapeutic avenue; however, the specific contributions of their molecular cargo remain poorly understood. This study explores whether astrocyte-derived exosomal delivery of microRNA-211-5p (miR-211-5p) can attenuate secondary injury and enhance functional recovery following TBI.
    METHODS: Primary astrocytes were transfected with AAV-rno-miR-211-5p, and the resulting exosomes were isolated and characterized. TBI was induced in adult rats using a controlled cortical impact (CCI) model. Exosomes (1 × 1011 particles) were administered intravenously 30 min post-injury. Behavioral assessments were conducted to evaluate cognitive function and neurological deficits. Brain edema, glial activation, and the expression of inflammatory cytokines (IL-6, IL-1β, TNF-α) and BBB-related markers-including glial fibrillary acidic protein (GFAP), matrix metalloproteinase 9 (MMP9), aquaporin 4 (AQP4), and the tight junction proteins zonula occludens-1 (ZO-1) and claudin-5-were analyzed using quantitative real-time PCR, Western blotting, enzyme-linked immunosorbent assay, and histopathological techniques.
    RESULTS: Exosomes enriched with miR-211-5p significantly improved cognitive and neurological outcomes, reduced cerebral edema, and downregulated the expression of GFAP, MMP9, and AQP4. Furthermore, the integrity of the BBB was preserved, as evidenced by sustained expression of ZO-1 and claudin-5. Levels of the proinflammatory cytokines IL-6, IL-1β, and TNF-α were also markedly decreased in the injured cortex.
    CONCLUSION: Astrocyte-derived exosomal miR-211-5p confers neuroprotection in TBI by modulating glial activation, reducing neuroinflammation, and preserving BBB integrity. These findings underscore the therapeutic potential of miR-211-5p-loaded exosomes as a cell-free, targeted intervention for brain trauma.
    Keywords:  astrocytes; brain trauma; exosomes; injury; neuroinflammation
    DOI:  https://doi.org/10.1002/cns.70858
  10. Geroscience. 2026 Apr 10.
      Niemann-Pick disease type C (NPC) is a rare autosomal recessive disorder characterized by progressive neurodegeneration, primarily caused by a functional defect in NPC1 resulting from gene mutations. NPC1, a lysosomal transmembrane protein, acts as a transporter of cholesterol from the lysosome to the endoplasmic reticulum, and its dysfunction results in the intracellular accumulation of unesterified cholesterol. Although microgliosis with accumulated cholesterol has been reported in NPC, the contribution of microglia to disease pathogenesis remains elusive. In this study, we demonstrated that microglia with increased cell numbers exhibit a cellular senescent phenotype in an NPC mouse model. Senescent microglia were transcriptionally and histologically segregated into two distinct major types, Cdkn1a⁺ and Cdkn2a⁺ subpopulations, with different cytokine and chemokine expression profiles. Notably, senescent microglia emerged specifically at sites of neuronal cell death in a region- and time-dependent manner. Our findings reveal previously unrecognized states of microglial senescence in the NPC mouse model and suggest that targeting senescent microglia provides a basis for a novel therapeutic strategy for NPC.
    Keywords:  Inflammatory cytokines; Microglia; Neuronal death; Niemann–Pick disease type C; Senescence; Single-cell RNA sequencing
    DOI:  https://doi.org/10.1007/s11357-026-02244-5
  11. J Neurosci. 2026 Apr 10. pii: e0112262026. [Epub ahead of print]
      Ventral horn microglia in the spinal cord proliferate after nerve injuries and migrate towards the cell bodies of injured motoneurons surrounding them. However, the significance of microglia enwrapping axotomized motoneurons has remained unclear. Moreover, some injured motoneurons degenerate while others regenerate. In mice spinal cords we found that each motoneuron fate associates with microglia of different activation profiles. Microglia surrounding degenerating motoneurons form cell clusters that fully envelop the cell body and express high TREM2 and large CD68 granules, with female microglia expressing higher levels. Microglia surrounding motoneurons undergoing regeneration remain individualized and also upregulate TREM2 and CD68, but to a lesser extent than microglia around degenerating motoneurons. Removal of TREM2, either globally throughout development or specifically in microglia prior to nerve injuries, reduces p-SYK signaling and CD68 expression in all activated microglia, but more so inside microglia forming tight cell clusters around degenerating motoneurons. This effect is also larger in females. TREM2 absence did not prevent microglia clustering around degenerating motoneurons but prevented the loss of some small MNs. In addition, TREM2 depletion interfered with the retrograde cell body chromatolytic reaction that is characteristic of regenerating motoneurons and delayed muscle reinnervation. We conclude that within the same motor pools, TREM2 facilitates microglia removal of some degenerating motoneurons while it facilitates regeneration of other motoneurons. The signals that direct the development of these different microglia phenotypes over degenerating and regenerating motoneurons, as well as the mechanisms that induce degeneration in some motoneurons while most others regenerate, remain to be investigated.Significance Statement Microglia frequently enwrap neurons undergoing cellular stress being one example the microglia reaction around motoneurons axotomized after nerve injuries. The significance of this microglia-neuron relationship is unclear. We found that microglia surrounding axotomized motoneurons upregulate TREM2, but with differences depending on whether microglia associated with regenerative or degenerative motoneurons. Loss-of-function experiments showed that TREM2 promotes removal of some degenerating motoneurons while facilitates the regeneration of others. We conclude that microglia TREM2 serves a dual function depending on the motoneuron health state. This knowledge is critical for designing future therapies that aim to improve motoneuron regeneration or preservation by altering TREM2 function.
    DOI:  https://doi.org/10.1523/JNEUROSCI.0112-26.2026
  12. Front Immunol. 2026 ;17 1664119
       Introduction: The selective prostacyclin (IP) receptor agonist selexipag is FDA-approved for the treatment of pulmonary arterial hypertension. Selexipag also has anti-inflammatory effects in peripheral tissues, but the ability of selexipag to modulate central neuroinflammation has not been comprehensively examined. Therefore, this study investigated the effect of selexipag on LPS-mediated neuroinflammatory responses in vitro and in vivo.
    Methods: To examine the effects of selexipag on LPS-mediated proinflammatory responses, BV2 or primary microglial cells were treated with vehicle (1% DMSO) or selexipag in dose (0.5, 1.0, or 5.0 μM) and time (3, 6, or 24 h)-dependent manner. For in vivo experiments, C57BL/6N mice were injected daily for 7 days with vehicle (1% DMSO) or selexipag (1 mg/kg, i.p.). On the 7th day, the mice were administered PBS or LPS (10 mg/kg, i.p.) and sacrificed 8 h later. Neuroinflammation-associated gene and protein expression were analyzed in vitro and in vivo by real-time PCR, ELISA, immunofluorescence staining, and/or western blotting.
    Results and discussion: We investigated the effect of IP receptor agonist selexipag on LPS-mediated neuroinflammatory responses in vitro and in vivo. Here, we found that selexipag treatment significantly reduced LPS-induced proinflammatory mediator COX-2, IL-1β, IL-6, and TNF-α mRNA and/or protein levels in BV2 microglial cells and primary microglial cells. In LPS-treated C57BL/6N mice, selexipag administration significantly attenuated microgliosis/astrogliosis, proinflammatory mediator expression, and neuroinflammatory-associated dynamics molecules. In addition, selexipag treatment significantly inhibited LPS-induced NLRP3 inflammasome activation in BV2 microglial cells, primary microglial cells and C57BL/6N mice. Importantly, the anti-inflammatory effects of selexipag treatment in BV2 microglial cells were dependent on NLRP3. Moreover, selexipag administration significantly increased cAMP levels, decreased LPS-induced P38 phosphorylation, and suppressed LPS-induced proinflammatory responses via a P38-dependent manner in LPS-treated C57BL/6N mice and/or BV2 microglial cells. Taken altogether, the present results suggest that the selective IP receptor agonist selexipag may be a promising therapeutic candidate for mitigating neuroinflammation-associated neurological disorders.
    Keywords:  IP receptor; LPS; NLRP3; P38; neuroinflammation; selexipag
    DOI:  https://doi.org/10.3389/fimmu.2026.1664119
  13. Front Immunol. 2026 ;17 1733688
      Glioma-associated microglia/macrophages (GAMs) have traditionally been described as immunosuppressive. However, within their highly heterogeneous repertoire, pro-phagocytic and cytotoxic subsets with anti-tumoral properties exist. Although macrophages (MACs) can exhibit tumor-suppressive functions, their anti-glioma properties largely remain elusive. To identify anti-glioma myeloid cell effectors, we performed directionally concatenated ligand-receptor (L-R) interactome analyses from dendritic cells (DCs) and microglia (MG) to lymphoid (CD4+T, Tregs, CD8+T, NK, and NKT) cells identified by our recent single-cell transcriptomics interrogation of tumor-associated CD45+ leukocytes from tumor brains of eighteen isocitrate dehydrogenase (IDH)-stratified glioma patients. Within DC-specific and MG-specific interactomes, we identified LGALS9, which encodes Galectin-9, as a key mediator of cell-cell interactions in IDH-wild type (IDH-wt) gliomas. Spectral cytometry, immunohistochemistry, and Western blotting analyses confirmed the abundant expression of Galectin-9 in glioma-associated MG, but not in tumor cells. Furthermore, differential gene enrichment analyses revealed transcripts associated with cellular adhesion (coronin 1A, integrin) and phagocytosis (FcγR, phospholipase D, Rab family proteins, etc.) pathways that were significantly upregulated in Galectin-9+ compared to Galectin-9- MG and MACs. Using an ex-vivo primary human microglia (pMG) and patient-derived glioma stem cells (GSCs) co-culture system, we evaluated the functional role of Galectin-9. Confocal imaging analyses of co-cultured pMG with GSCs revealed that siRNA-mediated knockdown or antibody-based neutralization of Galectin-9 significantly impaired pMG-GSC adhesion. In addition to reduced adhesion, phagocytosis of GSCs was dramatically attenuated across all Galectin-9 silenced or neutralized pMG. Altogether, our study underscores the unappreciated non-canonical role of Galectin-9 in MG as a regulator of glioma cell adhesion and phagocytosis that can be harnessed for glioblastoma immunotherapy.
    Keywords:  Galectin-9; cell adhesion; glioma; ligand-receptor interactome; microglia; phagocytosis; single cell RNA sequencing
    DOI:  https://doi.org/10.3389/fimmu.2026.1733688
  14. Prog Neurobiol. 2026 Apr 02. pii: S0301-0082(26)00037-7. [Epub ahead of print]261 102911
      Microglia regulate neural circuits and vascular-glial interfaces, yet whether microglial purinergic signaling coordinates glymphatic function and brain state remains unclear. We tested the role of the microglial Gi-coupled receptor P2Y12 using acute pharmacological inhibition with MRS2395 in adult mice. Glymphatic influx was quantified across circadian time by cisterna-magna tracer infusion and whole-brain fluorescence imaging, and related to microglial density and morphology assessed by Iba1 immunofluorescence and Sholl analysis in cortex, hippocampus, and amygdala. Sleep-wake architecture and cortical oscillations were evaluated by continuous 24-h EEG/EMG. In controls, microglial density and process complexity showed robust circadian rhythms that aligned with glymphatic timing. P2Y12 blockade reduced microglial density, flattened or rephased structural rhythms, and shifted glymphatic influx across the day-night cycle while preserving overall rhythmicity. Regionally, amygdala tracer signal correlated with Iba1⁺ cell density in controls and this coupling was lost after P2Y12 inhibition. Across regions, glymphatic readouts associated more strongly with microglial morphology than with cell number. EEG/EMG revealed no change in total sleep time with MRS2395, yet sleep architecture was reorganized: stage composition shifted toward NREM at the expense of REM, transitions between REM and NREM increased, bout durations shortened, and spectral power shifted toward slower activity, with higher gamma and lower alpha/theta/beta at multiple time points. These results identify microglial P2Y12 signaling as a temporal organizer that links microglial structural dynamics to perivascular fluid exchange and to sleep-wake organization. Disruption of this pathway alters the phase and stability of glymphatic and sleep rhythms, suggesting a neuroimmune target for conditions with circadian misalignment, sleep fragmentation, or impaired metabolic clearance.
    Keywords:  Circadian rhythms; EEG; Glymphatic system; Microglia; P2Y12; Purinergic signaling; Sleep architecture
    DOI:  https://doi.org/10.1016/j.pneurobio.2026.102911
  15. Acta Pharmacol Sin. 2026 Apr 09.
      Mitochondrial dysfunction, driven by genetic susceptibility or environmental insults, contributes to the pathogenesis of neurodegenerative disorders, including Parkinson's disease (PD). Mitophagy is a selective pathway that eliminates dysfunctional mitochondria, and mitophagy inducers hold therapeutic promise for neurodegeneration. However, the arsenal of specific, clinically viable inducers remains limited. ADT-OH, a slow-release H2S compound, was recently reported to induce mitochondrial uncoupling through sulfide-quinone oxidoreductase (SQR)-mediated oxidation of H2S. In this study, we report that ADT-OH elicits mitophagic flux in microglia. This is evidenced by the reduced steady-state levels of mitochondrial marker proteins (TOM20, COXIV, and HSP60), enhanced mitochondrial fission dynamics, and mitochondrial translocation into lysosomes, as visualized by the mt-Keima probe. Mechanistically, its mitophagy-promoting effect is dependent on SQR-mediated mitochondrial uncoupling and subsequent activation of PINK1-PARKIN signaling. Importantly, ADT-OH abrogates the accumulation of dysfunctional mitochondria and the subsequent cytosolic release of mitochondrial DNA in α-synuclein preformed fibrils (α-Syn PFF)-challenged microglia, thereby blunting the activation of the cGAS-STING pathway and the downstream production of inflammatory mediators. Furthermore, systemic administration of ADT-OH dampened microglial activation and cGAS expression in α-Syn-overexpressing PD mice, thereby mitigating the loss of midbrain dopaminergic neurons and ameliorating motor coordination deficits. Collectively, our findings demonstrate that ADT-OH exerts robust neuroprotective effects in PD models, both in vitro and in vivo, by enhancing mitophagy and inhibiting microglia-mediated neuroinflammation.
    Keywords:  ADT-OH; Parkinson’s disease; cGAS-STING; microglia; mitochondrial DNA; mitophagy
    DOI:  https://doi.org/10.1038/s41401-026-01789-7
  16. Neurobiol Stress. 2026 Jun;42 100804
      Microglia-mediated neuroinflammation is widely recognized as a key contributor to various neurological diseases and psychiatric disorders, including depression; however, its underlying mechanisms remain incompletely understood. In this study, we observed a significant reduction in SIRT6 expression in neural cells, alongside a marked increase in microglial SIRT6, in a lipopolysaccharide (LPS)-induced depression model. We demonstrated that microglia-specific Sirt6 knockout (Sirt6MCKO) mice exhibited clear morphological signs of microglial activation, elevated levels of inflammatory cytokines, and enhanced peroxidative damage, ultimately leading to aggravated depression-like behaviors. Mechanistically, SIRT6 was found to regulate microglial activation via the NRF2-HO1 signaling pathway in this model. This regulatory role was substantiated by the observation that microglia-specific Nrf2 knockout mice phenocopied the depressive-like phenotypes of Sirt6MCKO mice under LPS challenge. Conversely, overexpression of Nrf2 in Sirt6MCKO mice markedly attenuated microglial activation, peroxidative damage, and depressive behaviors. Notably, specific reintroduction of SIRT6 in microglia fully rescued the pathological phenotypes in Sirt6MCKO mice. In a translational approach, pharmacological activation of SIRT6 with UBCS039 robustly suppressed microglial activation, along with its downstream inflammatory and peroxidative effects, thereby ameliorating depression-like behaviors and nominating UBCS039 as a novel therapeutic candidate for depression.
    Keywords:  Depression; Microglial; NRF2-HO1 signaling; SIRT6
    DOI:  https://doi.org/10.1016/j.ynstr.2026.100804