OBJECTIVES: To explore the effect of quercetin for mitigating HIV-1 gp120-induced astrocyte neurotoxicity and its underlying mechanism. METHODS: Primary rat astrocytes were isolated and treated with quercetin, HIV-1 gp120, or gradient concentrations of quercetin combined with HIV-1 gp120. The formation of stress granules (SGs) in the treated cells was observed with immunofluorescence assay, and the levels of oxidative stress markers and protein expressions were measured using specific assay kits and Western blotting. HIV-1 gp120 transgenic mice were treated with quercetin (50 mg/kg) by gavage for 4 weeks, and the changes in cognitive functions and oxidative stress levels were examined by behavioral assessments, oxidative stress index analysis in serum, and immunohistochemical and Western blotting of the brain tissue. RESULTS: In primary rat astrocytes, treatment with quercetin significantly reduced HIV-1 gp120-induced SG formation, increased the levels of antioxidant indexes, decreased the levels of oxidative substances, and up-regulated protein level associated with SG depolymerization. In the transgenic mouse models, quercetin obviously improved the cognitive function of the rats, reduced oxidative stress levels, and promoted the expression of proteins associate with SG depolymerization in the brain tissues. CONCLUSIONS Quercetin mitigates HIV-1 gp120-induced astrocyte neurotoxicity and cognitive function impairment by inhibiting oxidative stress, enhancing expressions of SG depolymerization-related proteins, and promoting SG disassembly, suggesting the value of quercetin as a potential therapeutic agent for neuroprotection in HIV-associated neurocognitive disorders.
Animals ; Quercetin/pharmacology* ; Astrocytes/metabolism* ; HIV Envelope Protein gp120 ; Oxidative Stress/drug effects* ; Rats ; Stress Granules/drug effects* ; Mice ; Mice, Transgenic ; Rats, Sprague-Dawley ; Cells, Cultured

OBJECTIVES: To explore the effect of A. muciniphila gavage on intestinal microbiota and gut-brain interaction disorders (DGBIs) in gp120tg transgenic mouse models of HIV-associated neurocognitive disorder (HAND). METHODS: Intestinal microbiota was detected by 16S rRNA gene sequencing in 6-, 9-, and 12-month-old wild-type (WT) mice and gp120tg transgenic mice. The 12-month-old WT and transgenic mice were divided into 2 groups for daily treatment with PBS or A.muciniphila gavage (2×10⁸ CFU/mouse) for 6 weeks. After the treatment, immunohistochemistry, ELISA and qPCR were used to detect changes in colonic expression levels of glycosylated mucins, MBP and IL-1β, eosinophil infiltration, serum lipopolysaccharide (LPS) levels, and colonic expressions of occludin, ZO-1, IL-10, TNF-α and INF-γ mRNA. Morris water maze test and immunofluorescence assay were used to assess learning and spatial memory abilities and neuronal damage of the mice. RESULTS: Compared with WT mice, the transgenic mice exhibited significantly lowered Simpson's diversity of the intestinal microbiota with reduced abundance of Akkermansia genus, increased serum LPS levels and decreased colonic expression of glycosylated mucin. A.muciniphila gavage obviously ameliorated the reduction of glycosylated mucin in the transgenic mice without causing significant changes in body weight. The 12-month-old gp120tg mice had significantly decreased cdonic expressions of Occludin and ZO-1 with increased eosinophil infiltration and TNF-β, INF-γ and IL-1β levels and obviously lowered IL-10 level; all these changes were significantly mitigated by A.muciniphila gavage, which also improved cognitive impairment and neuronal loss in the hippocampus and cortex of the transgenic mice. CONCLUSIONS The gp120tg mice have lower intestinal microbiota richness and diversity than WT mice. The 12-month-old gp120tg mice have significantly reduced Akkermansia abundance with distinct DGBIs-related indexes, and A. muciniphila gavage can reduce intestinal barrier injury, colonic inflammation and eosinophil activation, cognitive impairment and brain neuron injury in these mice.
Animals ; Mice, Transgenic ; Gastrointestinal Microbiome ; Mice ; Brain ; HIV Envelope Protein gp120/genetics* ; Akkermansia ; Disease Models, Animal

Anxiety disorder is a major symptom of autism spectrum disorder (ASD) with a comorbidity rate of ~40%. However, the neural mechanisms of the emergence of anxiety in ASD remain unclear. In our study, we found that hyperactivity of basolateral amygdala (BLA) pyramidal neurons (PNs) in Shank3 InsG3680 knock-in (InsG3680^+/+) mice is involved in the development of anxiety. Electrophysiological results also showed increased excitatory input and decreased inhibitory input in BLA PNs. Chemogenetic inhibition of the excitability of PNs in the BLA rescued the anxiety phenotype of InsG3680^+/+ mice. Further study found that the diminished control of the BLA by medial prefrontal cortex (mPFC) and optogenetic activation of the mPFC-BLA pathway also had a rescue effect, which increased the feedforward inhibition of the BLA. Taken together, our results suggest that hyperactivity of the BLA and alteration of the mPFC-BLA circuitry are involved in anxiety in InsG3680^+/+ mice.
Animals ; Prefrontal Cortex/metabolism* ; Basolateral Nuclear Complex/metabolism* ; Mice ; Anxiety/metabolism* ; Nerve Tissue Proteins/genetics* ; Male ; Gene Knock-In Techniques ; Pyramidal Cells/physiology* ; Mice, Transgenic ; Neural Pathways/physiopathology* ; Mice, Inbred C57BL ; Microfilament Proteins

Noise-induced hearing loss is a worldwide public health issue that is characterized by temporary or permanent changes in hearing sensitivity. This condition is closely linked to inflammatory responses, and interventions targeting the inflammatory gene tumor necrosis factor-alpha (TNFα) are known to mitigate cochlear noise damage. TNFα-induced proteins (TNFAIPs) are a family of translucent acidic proteins, and TNFAIP6 has a notable association with inflammatory responses. To date, there have been few reports on TNFAIP6 levels in the inner ear. To elucidate the precise mechanism, we generated transgenic mouse models with conditional knockout of Tnfaip6 (Tnfaip6 cKO). Evaluation of hair cell morphology and function revealed no significant differences in hair cell numbers or ribbon synapses between Tnfaip6 cKO and wild-type mice. Moreover, there were no notable variations in hair cell numbers or hearing function in noisy environments. Our results indicate that Tnfaip6 does not have a substantial impact on the auditory system.
Animals ; Mice, Knockout ; Hair Cells, Auditory, Inner/pathology* ; Mice ; Mice, Transgenic ; Hearing Loss, Noise-Induced ; Evoked Potentials, Auditory, Brain Stem/physiology*

Alzheimer's disease (AD), a neurodegenerative disorder with complex etiologies, manifests through a cascade of pathological changes before clinical symptoms become apparent. Among these early changes, alterations in the expression of non-coding RNAs (ncRNAs) have emerged as pivotal events. In this study, we focused on the aberrant expression of ncRNAs and revealed that Lamr1-ps1, a pseudogene of the laminin receptor, significantly exacerbates early spatial learning and memory deficits in APP/PS1 mice. Through a combination of bioinformatics prediction and experimental validation, we identified the miR-29c/Bace1 pathway as a potential regulatory mechanism by which Lamr1-ps1 influences AD pathology. Importantly, augmenting the miR-29c-3p levels in mice ameliorated memory deficits, underscoring the therapeutic potential of targeting miR-29c-3p in early AD intervention. This study not only provides new insights into the role of pseudogenes in AD but also consolidates a foundational basis for considering miR-29c as a viable therapeutic target, offering a novel avenue for AD research and treatment strategies.
Animals ; Alzheimer Disease/pathology* ; Pseudogenes/genetics* ; Mice ; Memory Disorders/metabolism* ; MicroRNAs/genetics* ; Disease Models, Animal ; Spatial Learning/physiology* ; Mice, Transgenic ; Presenilin-1/genetics* ; Male ; Amyloid Precursor Protein Secretases/metabolism* ; Mice, Inbred C57BL ; Aspartic Acid Endopeptidases/metabolism*

Alzheimer's disease (AD) poses one of the most urgent medical challenges in the 21st century as it affects millions of people. Unfortunately, the etiopathogenesis of AD is not yet fully understood and the current pharmacotherapy options are somewhat limited. Here, we report a novel inhibitor, Compound 44, for targeting cholinesterases, amyloid-β (Aβ) aggregation, and glycogen synthase kinase 3β (GSK-3β) simultaneously with the aim of achieving symptomatic relief and disease modification in AD therapy. We found that Compound 44 had good inhibitory effects on all intended targets with IC₅₀s of submicromolar or better, significant neuroprotective effects in cell models, and beneficial improvement of cognitive deficits in the triple transgenic AD (3 × Tg AD) mouse model. Moreover, we showed that Compound 44 acts as an autophagy regulator by inducing nuclear translocation of transcription factor EB through GSK-3β inhibition, enhancing the biogenesis of lysosomes and elevating autophagic flux, thus ameliorating the amyloid burden and tauopathy, as well as mitigating the disease phenotype. Our results suggest that triple-target inhibition via Compound 44 could be a promising strategy that may lead to the development of effective therapeutic approaches for AD.
Animals ; Alzheimer Disease/genetics* ; Mice, Transgenic ; Glycogen Synthase Kinase 3 beta/metabolism* ; Disease Models, Animal ; Mice ; Amyloid beta-Peptides/metabolism* ; Cholinesterase Inhibitors/therapeutic use* ; Humans ; Autophagy/drug effects* ; Cognitive Dysfunction/pathology* ; Neuroprotective Agents/pharmacology*

Vascular damage plays a significant role in the onset and progression of Alzheimer's disease (AD). However, the precise molecular mechanisms underlying the induction of neuronal injury by vascular damage remain unclear. The present study aimed to examine the impact of fibrinogen (Fg) on tau pathology. The results showed that Fg deposits in the brains of tau P301S transgenic mice interact with tau, enhancing the cytotoxicity of pathological tau aggregates and promoting tau phosphorylation and aggregation. Notably, Fg-modified tau fibrils caused enhanced neuronal apoptosis and synaptic damage compared to unmodified fibrils. Furthermore, intrahippocampal injection of Fg-modified tau fibrils worsened the tau pathology, neuroinflammation, synaptic damage, neuronal apoptosis, and cognitive dysfunction in tau P301S mice compared to controls. The present study provides compelling evidence linking Fg and tau, thereby connecting cerebrovascular damage to tau pathology in AD. Consequently, inhibiting Fg-mediated tau pathology could potentially impede the progression of AD.
Animals ; tau Proteins/metabolism* ; Alzheimer Disease/metabolism* ; Fibrinogen/metabolism* ; Mice, Transgenic ; Mice ; Disease Models, Animal ; Memory Disorders/metabolism* ; Male ; Mice, Inbred C57BL ; Brain/metabolism* ; Hippocampus/metabolism* ; Protein Aggregation, Pathological/metabolism* ; Apoptosis ; Phosphorylation

Neuropathic pain, often featuring allodynia, imposes significant physical and psychological burdens on patients, with limited treatments due to unclear central mechanisms. Addressing this challenge remains a crucial unsolved issue in pain medicine. Our previous study, using protein kinase C gamma (PKCγ)-tdTomato mice, highlights the spinal feedforward inhibitory circuit involving PKCγ neurons in gating neuropathic allodynia. However, the regulatory mechanisms governing this circuit necessitate further elucidation. We used diverse transgenic mice and advanced techniques to uncover the regulatory role of the descending serotonin (5-HT) facilitation system on spinal PKCγ neurons. Our findings revealed that 5-HT neurons from the rostral ventromedial medulla hyperpolarize spinal inhibitory interneurons via 5-HT_2C receptors, disinhibiting the feedforward inhibitory circuit involving PKCγ neurons and exacerbating allodynia. Inhibiting spinal 5-HT_2C receptors restored the feedforward inhibitory circuit, effectively preventing neuropathic allodynia. These insights offer promising therapeutic targets for neuropathic allodynia management, emphasizing the potential of spinal 5-HT_2C receptors as a novel avenue for intervention.
Animals ; Neuralgia/physiopathology* ; Protein Kinase C/metabolism* ; Receptor, Serotonin, 5-HT2C/metabolism* ; Hyperalgesia/physiopathology* ; Mice, Transgenic ; Mice ; Spinal Cord/metabolism* ; Serotonin/metabolism* ; Male ; Neurons/metabolism* ; Mice, Inbred C57BL

Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder worldwide, causing dementia and affecting millions of individuals. One prominent characteristic in the brains of AD patients is glucose hypometabolism. In the context of galactose metabolism, intracellular glucose levels are heightened. Galactose mutarotase (GALM) plays a crucial role in maintaining normal galactose metabolism by catalyzing the conversion of β-D-galactose into α-D-galactose (α-D-G). The latter is then converted into glucose-6-phosphate, improving glucose metabolism levels. However, the involvement of GALM in AD progression is still unclear. In the present study, we found that the expression of GALM was significantly increased in AD patients and model mice. Genetic knockdown of GALM using adeno-associated virus did not change the expression of amyloid precursor protein (APP) and APP-cleaving enzymes including a disintegrin and metalloprotease 10 (ADAM10), β-site APP-cleaving enzyme 1 (BACE1), and presenilin-1 (PS1). Interestingly, genetic overexpression of GALM reduced APP and Aβ deposition by increasing the maturation of ADAM10, although it did not alter the expression of BACE1 and PS1. Further electrophysiological and behavioral experiments showed that GALM overexpression significantly ameliorated the deficits in hippocampal CA1 long-term potentiation (LTP) and spatial learning and memory in AD model mice. Importantly, direct α-D-G (20 mg/kg, i.p.) also inhibited Aβ deposition by increasing the maturation of ADAM10, thereby improving hippocampal CA1 LTP and spatial learning and memory in AD model mice. Taken together, our results indicate that GALM shifts APP processing towards α-cleavage, preventing Aβ generation by increasing the level of mature ADAM10. These findings indicate that GALM may be a potential therapeutic target for AD, and α-D-G has the potential to be used as a dietary supplement for the prevention and treatment of AD.
Animals ; ADAM10 Protein/metabolism* ; Alzheimer Disease/pathology* ; Amyloid Precursor Protein Secretases/metabolism* ; Disease Models, Animal ; Humans ; Mice ; Amyloid beta-Peptides/metabolism* ; Male ; Mice, Transgenic ; Membrane Proteins/metabolism* ; Cognitive Dysfunction/pathology* ; Mice, Inbred C57BL ; Amyloid beta-Protein Precursor/metabolism* ; Female ; Hippocampus/metabolism* ; Long-Term Potentiation/physiology*

Sexual dimorphism in the brain underlies behavioral differences between sexes. The bed nucleus of the stria terminalis (BNST) is a complex nucleus that differs between males and females, but the sexual dimorphism in cytoarchitecture and the connectome of its oval subdivision (ovBNST) remains largely unexplored. By combining snRNA-seq and transgenic labeling, we found a higher density of ovBNST proenkephalin (ovBNST^PENK) neurons in male than female mice. Anatomically, we virally mapped the efferents and afferents of ovBNST^PENK neurons, finding reciprocally dimorphic connections with the hypothalamus and striatum. Gene enrichment analysis suggests that ovBNST^PENK neurons are modulated by the upstream dopamine pathway. Functionally, by applying caspase-3-mediated depletion of ovBNST^PENK neurons, we found that loss of these neurons enhanced locomotor activity in male but not female mice, without altering the anxiety-like phenotypes in either sex. Our study may pave the way for a better understanding of the anatomical and functional profiles of ovBNST^PENK neurons from a sexually dimorphic perspective.
Animals ; Male ; Female ; Septal Nuclei/physiology* ; Sex Characteristics ; Neurons/physiology* ; Enkephalins/metabolism* ; Mice ; Mice, Transgenic ; Protein Precursors/metabolism* ; Mice, Inbred C57BL ; Neural Pathways/physiology*