Diploid species phylogeny and evolutionary reticulation indicate early radiation of Ephedra in the Tethys coast.

Reconstructing a robust species phylogeny and disentangling the evolutionary and biogeographic history of the gymnosperm genus Ephedra, which has a large genome and rich polyploids, remain a big challenge. Here we reconstructed a transcriptome-based phylogeny of 19 diploid Ephedra species, and explored evolutionary reticulations in this genus represented by 50 diploid and polyploid species, using four low-copy nuclear and nine plastid genes. The diploid species phylogeny indicates that the Mediterranean species diverged first, and the remaining species split into three clades, including the American species (Clade A), E. rhytidosperma, and all other Asian species (Clade B). The single-gene trees placed E. rhytidosperma sister to Clade A, Clade B, or Clades A + B in similar proportions, suggesting that radiation and gene flow likely occurred in the early evolution of Ephedra. In addition, reticulate evolution occurred not only among the deep nodes, but also in the recently evolved South American species, which further caused difficulty in phylogenetic reconstruction. Moreover, we found that allopolyploid speciation was pervasive in Ephedra. Our study also suggests that Ephedra very likely originated in the Tethys coast during the late Cretaceous, and the South American Ephedra species have a single origin by dispersal from Mexico or North America.

Interleukin-7-loaded oncolytic adenovirus improves CAR-T cell therapy for glioblastoma.

BACKGROUND: T cell with chimeric antigen receptors (CAR-T) has presented remarkable efficacy for blood cancer as an emerging immunotherapy. However, for solid tumors, the therapeutic efficacy is much impaired due to the lack of infiltration and persistence of CAR-T in tumor tissue. Thus, we constructed an interleukin-7-loaded oncolytic adenovirus and combined the use of oncolytic virus and CAR-T to improve the therapeutic outcome. METHODS: We constructed an interleukin-7-loaded oncolytic adenovirus (oAD-IL7) and a B7H3-targeted CAR-T and explored the efficacy of the single use of oAD-IL7, B7H3-CAR-T, or the combined therapy for glioblastoma in vitro and in vivo. The improved CAR-T anti-tumor efficacy was evaluated according to the proliferation, survival, persistence, exhaustion of T cells, and tumor regression. RESULTS: Constructed oAD-IL7 and B7H3-CAR-T presented moderate cytotoxicity during in vitro study, but failed to induce a thorough and persistent anti-tumor therapeutic efficacy in vivo. The combination of oAD-IL7 and B7H3-CAR-T in vitro resulted in enhanced T cell proliferation and reduced T cell apoptosis. The joint efficacy was further confirmed using tumor-bearing xenograft mice. During in vivo study, the mice treated with both oAD-IL7 and B7H3-CAR-T showed prolonged survival and reduced tumor burden. According to the ex vivo study, oAD-IL7 improved the proliferation and persistence of tumor-infiltrating B7H3-CAR-T, but failed to reverse the exhaustion. CONCLUSIONS: Our results indicated that oAD-IL7 is a promising auxiliary therapy to improve the therapeutic efficacy of B7H3-CAR-T in glioblastoma by providing the activating signals for tumor-infiltrating T cells. Our results also lay the basis for the future clinical trials for the combination of IL7-loaded oncolytic adenovirus and CAR-T therapy for glioblastoma.

Evaluation of time to positivity for blood culture combined with immature granulocytes, neutrophil-to-lymphocyte ratio, and CRP in identifying bloodstream coagulase-negative Staphylococci infection in pediatric patients.

OBJECTIVE: To evaluate the application value of time to positivity (TTP) for blood culture combined with inflammatory parameters that included immature granulocyte percentage (IG%), immature granulocyte count (IG#), C-reactive protein (CRP), white blood cells (WBC) neutrophil percentage (NE%), and neutrophil-to-lymphocyte ratio (NLR), and to identify bloodstream infections from contamination with coagulase-negative staphylococci (CoNS) in pediatric patients. METHODS: Data of 12 897 inpatients with blood culture CoNS were retrospectively collected and analyzed from January-December 2019 at our hospital. According to pre-defined criteria, they were divided into a CoNS infection group (132 cases) and a CoNS contamination group (124 cases). Infection with Staphylococcus aureus (SA, 27 cases) at the same period was considered a positive control group. ROC curve analysis assisted in determining the value of applying TTP combined with the above-mentioned inflammatory parameters to distinguish CoNS infection from contamination. RESULTS: Among the 256 strains of CoNS, Staphylococcus hominis (55.1%), Staphylococcus epidermidis (32.0%), and Staphylococcus capitis (7.0%) were common. There was no significant difference in the subspecies distribution between the infection and contamination groups. The TTP of the CoNS infection group was significantly lower than the contamination group (P < .05). IG%, IG#, CRP, NE%, and NLR were all higher in the infected group as compared to the contaminated group (P < .05), while WBC was similar among groups. There was also no statistical difference in those parameters when comparing the CoNS infection and SA groups. ROC analysis showed that TTP value in identifying CoNS infection from contamination was the highest with area under the curve (AUC) of 0.913, and the sensitivity and specificity were 0.827 and 0.852, respectively, at the optimal cutoff value of 23.9 hours. This was followed by IG% (AUC = 0.712), with an optimal critical value of 0.55%, and a sensitivity of 0.519 and specificity of 0.797. All the AUC values of IG#, CRP, NE%, and NLR were <0.7. A combination of TTP with IG%, CRP, and NLR improved the AUC, sensitivity, specificity, accuracy, PPV, and NPV values to 0.977, 0.922, 0.957, 91.8%, 92.2%, and 91.3%, respectively. CONCLUSIONS: TTP within 24 hours indicates likelihood of CoNS as the pathogenic agent in pediatric patient blood culture. The combination of TTP with IG% CRP and NLR might improve the diagnostic accuracy.

Curcumin attenuates blood-brain barrier disruption after subarachnoid hemorrhage in mice.

BACKGROUND: Early brain injury, one of the most important mechanisms underlying subarachnoid hemorrhage (SAH), comprises edema formation and blood-brain barrier (BBB) disruption. Curcumin, an active extract from the rhizomes of Curcuma longa, alleviates neuroinflammation by as yet unknown neuroprotective mechanisms. In this study, we examined whether curcumin treatment ameliorates SAH-induced brain edema and BBB permeability changes, as well as the mechanisms underlying this phenomenon. METHODS: We induced SAH in mice via endovascular perforation, administered curcumin 15 min after surgery and evaluated neurologic scores, brain water content, Evans blue extravasation, Western blot assay results, and immunohistochemical analysis results 24 h after surgery. RESULTS: Curcumin significantly improved neurologic scores and reduced brain water content in treated mice compared with SAH mice. Furthermore, curcumin decreased Evans blue extravasation, matrix metallopeptidase-9 expression, and the number of Iba-1-positive microglia in treated mice compared with SAH mice. At last, curcumin treatment increased the expression of the tight junction proteins zonula occludens-1 and occludin in treated mice compared with vehicle-treated and sample SAH mice. CONCLUSIONS: We demonstrated that curcumin inhibits microglial activation and matrix metallopeptidase-9 expression, thereby reducing brain edema and attenuating post-SAH BBB disruption in mice.

Membrane remodeling by FAM92A1 during brain development regulates neuronal morphology, synaptic function, and cognition.

The Bin/Amphiphysin/Rvs (BAR) domain protein FAM92A1 is a multifunctional protein engaged in regulating mitochondrial ultrastructure and ciliogenesis, but its physiological role in the brain remains unclear. Here, we show that FAM92A1 is expressed in neurons starting from embryonic development. FAM92A1 knockout in mice results in altered brain morphology and age-associated cognitive deficits, potentially due to neuronal degeneration and disrupted synaptic plasticity. Specifically, FAM92A1 deficiency impairs diverse neuronal membrane morphology, including the mitochondrial inner membrane, myelin sheath, and synapses, indicating its roles in membrane remodeling and maintenance. By determining the crystal structure of the FAM92A1 BAR domain, combined with atomistic molecular dynamics simulations, we uncover that FAM92A1 interacts with phosphoinositide- and cardiolipin-containing membranes to induce lipid-clustering and membrane curvature. Altogether, these findings reveal the physiological role of FAM92A1 in the brain, highlighting its impact on synaptic plasticity and neural function through the regulation of membrane remodeling and endocytic processes.

Hippocampal circAnk3 Deficiency Causes Anxiety-like Behaviors and Social Deficits by Regulating the miR-7080-3p/IQGAP1 Pathway in Mice.

BACKGROUND: Circular RNAs are highly enriched in the synapses of the mammalian brain and play important roles in neurological function by acting as molecular sponges of microRNAs. circAnk3 is derived from the 11th intron of the ankyrin-3 gene, Ank3, a strong genetic risk factor for neuropsychiatric disorders; however, the function of circAnk3 remains elusive. In this study, we investigated the function of circAnk3 and its downstream regulatory network for target genes in the hippocampus of mice. METHODS: The DNA sequence from which circAnk3 is generated was modified using CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/Cas9) technology, and neurobehavioral tests (anxiety and depression-like behaviors, social behaviors) were performed in circAnk3+/- mice. A series of molecular and biochemical assays were used to investigate the function of circAnk3 as a microRNA sponge and its downstream regulatory network for target genes. RESULTS: circAnk3+/- mice exhibited both anxiety-like behaviors and social deficits. circAnk3 was predominantly located in the cytoplasm of neuronal cells and functioned as a miR-7080-3p sponge to regulate the expression of Iqgap1. Inhibition of miR-7080-3p or restoration of Iqgap1 in the hippocampus ameliorated the behavioral deficits of circAnk3+/- mice. Furthermore, circAnk3 deficiency decreased the expression of the NMDA receptor subunit GluN2a and impaired the structural plasticity of dendritic synapses in the hippocampus. CONCLUSIONS: Our results reveal an important role of the circAnk3/miR-7080-3p/IQGAP1 axis in maintaining the structural plasticity of hippocampal synapses. circAnk3 might offer new insights into the involvement of circular RNAs in neuropsychiatric disorders.

Pyruvate dehydrogenase complex E1 subunit α crotonylation modulates cocaine-associated memory through hippocampal neuron activation.

Neuronal activation is required for the formation of drug-associated memory, which is critical for the development, persistence, and relapse of drug addiction. Nevertheless, the metabolic mechanisms underlying energy production for neuronal activation remain poorly understood. In the study, a large-scale proteomics analysis of lysine crotonylation (Kcr), a type of protein posttranslational modification (PTM), reveals that cocaine promoted protein Kcr in the hippocampal dorsal dentate gyrus (dDG). We find that Kcr is predominantly discovered in a few enzymes critical for mitochondrial energy metabolism; in particular, pyruvate dehydrogenase (PDH) complex E1 subunit α (PDHA1) is crotonylated at the lysine 39 (K39) residue through P300 catalysis. Crotonylated PDHA1 promotes pyruvate metabolism by activating PDH to increase ATP production, thus providing energy for hippocampal neuronal activation and promoting cocaine-associated memory recall. Our findings identify Kcr of PDHA1 as a PTM that promotes pyruvate metabolism to enhance neuronal activity for cocaine-associated memory.

Association between vascular risk factors and idiopathic normal pressure hydrocephalus: a Mendelian randomization study.

BACKGROUND AND OBJECTIVE: Patients with idiopathic normal pressure hydrocephalus (iNPH) have a higher prevalence of hypertension and diabetes. However, the causal effects of these vascular risk factors on iNPH remain unclear. This study aimed to explore the causal relationship between vascular risk factors (VRFs) and iNPH. METHODS: We conducted the Mendelian randomization (MR) analysis of iNPH. We included nineteen vascular risk factors related to hypertension, diabetes, lipids, obesity, smoking, alcohol consumption, exercise, sleep, and cardiovascular events as exposure factors. We used the inverse-variance weighted method for causal effect estimation and weighted median, maximum likelihood, and MR Egger regression methods for sensitivity analyses. RESULTS: We found that genetically predicting essential hypertension (OR = 1.608 (1.330-1.944), p = 0.013) and increased sleep duration (OR = 16.395 (5.624-47.799), p = 0.009) were associated with higher odds of iNPH. Type 1 diabetes (OR = 0.869 (0.828-0.913), p = 0.004) was associated with lower odds of iNPH. For the other 16 VRFs, there was no evidence that they were significantly associated with iNPH. Sensitivity analyses showed that essential hypertension and type 1 diabetes were significantly associated with iNPH. CONCLUSION: In our MR study on VRFs and iNPH, we found essential hypertension to be a causal risk factor for iNPH. This suggests that hypertension may be involved in the pathophysiological mechanism of iNPH.

HDAC3 inhibitor (BRD3308) modulates microglial pyroptosis and neuroinflammation through PPARγ/NLRP3/GSDMD to improve neurological function after intraventricular hemorrhage in mice.

Neuroinflammation plays a vital role in intraventricular hemorrhage (IVH). Excessive neuroinflammation after IVH can activate the inflammasome in the cell and accelerate the occurrence of pyroptosis in cells, produce more inflammatory mediators, increase cell death, and lead to neurological deficits. Previous studies have reported that BRD3308 (BRD), an inhibitor of histone deacetylation by histone deacetylase 3 (HDAC3), suppresses inflammation-induced apoptosis and exhibits anti-inflammatory properties. However, it is unclear how BRD reduces the occurrence of the inflammatory cascade. In this study, we stereotactically punctured the ventricles of male C57BL/6J mice and injected autologous blood via the tail vein to simulate ventricular hemorrhage. Magnetic resonance imaging was used to detect ventricular hemorrhage and enlargement. Our findings demonstrated that BRD treatment significantly improved neurobehavioral performance and decreased neuronal loss, microglial activation, and pyroptosis in the hippocampus after IVH. At the molecular level, this treatment upregulated the expression of peroxisome proliferator-activated receptor γ (PPARγ) and inhibited NLRP3-mediated pyroptosis and inflammatory cytokines. Therefore, we concluded that BRD reduced pyroptosis and neuroinflammation and improve nerve function in part by activating the PPARγ/NLRP3/GSDMD signaling pathway. Our findings suggest a potential preventive role for BRD in IVH.

Cardiolipin and OPA1 Team up for Methamphetamine-Induced Locomotor Activity by Promoting Neuronal Mitochondrial Fusion in the Nucleus Accumbens of Mice.

Mitochondria are highly dynamic organelles with coordinated cycles of fission and fusion occurring continuously to satisfy the energy demands in the complex architecture of neurons. How mitochondria contribute to addicted drug-induced adaptable mitochondrial networks and neuroplasticity remains largely unknown. Through liquid chromatography-mass spectrometry-based lipidomics, we first analyzed the alteration of the mitochondrial lipidome of three mouse brain areas in methamphetamine (METH)-induced locomotor activity and conditioned place preference. The results showed that METH remodeled the mitochondrial lipidome of the hippocampus, nucleus accumbens (NAc), and striatum in both models. Notably, mitochondrial hallmark lipid cardiolipin (CL) was specifically increased in the NAc in METH-induced hyperlocomotor activity, which was accompanied by an elongated giant mitochondrial morphology. Moreover, METH significantly boosted mitochondrial respiration and ATP generation as well as the copy number of mitochondrial genome DNA in the NAc. By screening the expressions of mitochondrial dynamin-related proteins, we found that repeated METH significantly upregulated the expression of long-form optic atrophy type 1 (L-OPA1) and enhanced the interaction of L-OPA1 with CL, which may promote mitochondrial fusion in the NAc. On the contrary, neuronal OPA1 depletion in the NAc not only recovered the dysregulated mitochondrial morphology and synaptic vesicle distribution induced by METH but also attenuated the psychomotor effect of METH. Collectively, upregulated CL and OPA1 cooperate to mediate METH-induced adaptation of neuronal mitochondrial dynamics in the NAc, which correlates with the psychomotor effect of METH. These findings propose a potential therapeutic approach for METH addiction by inhibiting neuronal mitochondrial fusion.

Neurodevelopmental defects in human cortical organoids with N-acetylneuraminic acid synthase mutation.

Biallelic genetic variants in N-acetylneuraminic acid synthase (NANS), a critical enzyme in endogenous sialic acid biosynthesis, are clinically associated with neurodevelopmental disorders. However, the mechanism underlying the neuropathological consequences has remained elusive. Here, we found that NANS mutation resulted in the absence of both sialic acid and protein polysialylation in the cortical organoids and notably reduced the proliferation and expansion of neural progenitors. NANS mutation dysregulated neural migration and differentiation, disturbed synapse formation, and weakened neuronal activity. Single-cell RNA sequencing revealed that NANS loss of function markedly altered transcriptional programs involved in neuronal differentiation and ribosomal biogenesis in various neuronal cell types. Similarly, Nans heterozygous mice exhibited impaired cortical neurogenesis and neurobehavioral deficits. Collectively, our findings reveal a crucial role of NANS-mediated endogenous sialic acid biosynthesis in regulating multiple features of human cortical development, thus linking NANS mutation with its clinically relevant neurodevelopmental disorders.

Morphine Re-arranges Chromatin Spatial Architecture of Primate Cortical Neurons.

The expression of linear DNA sequence is precisely regulated by the three-dimensional (3D) architecture of chromatin. Morphine-induced aberrant gene networks of neurons have been extensively investigated; however, how morphine impacts the 3D genomic architecture of neurons is still unknown. Here, we applied digestion-ligation-only high-throughput chromosome conformation capture (DLO Hi-C) technology to investigate the effects of morphine on the 3D chromatin architecture of primate cortical neurons. After receiving continuous morphine administration for 90 days on rhesus monkeys, we discovered that morphine re-arranged chromosome territories, with a total of 391 segmented compartments being switched. Morphine altered over half of the detected topologically associated domains (TADs), most of which exhibited a variety of shifts, followed by separating and fusing types. Analysis of the looping events at kilobase-scale resolution revealed that morphine increased not only the number but also the length of differential loops. Moreover, all identified differentially expressed genes from the RNA sequencing data were mapped to the specific TAD boundaries or differential loops, and were further validated for changed expression. Collectively, an altered 3D genomic architecture of cortical neurons may regulate the gene networks associated with morphine effects. Our finding provides critical hubs connecting chromosome spatial organization and gene networks associated with the morphine effects in humans.

Three-dimensional-printed collagen/chitosan/secretome derived from HUCMSCs scaffolds for efficient neural network reconstruction in canines with traumatic brain injury.

The secretome secreted by stem cells and bioactive material has emerged as a promising therapeutic choice for traumatic brain injury (TBI). We aimed to determine the effect of 3D-printed collagen/chitosan/secretome derived from human umbilical cord blood mesenchymal stem cells scaffolds (3D-CC-ST) on the injured tissue regeneration process. 3D-CC-ST was performed using 3D printing technology at a low temperature (-20°C), and the physical properties and degeneration rate were measured. The utilization of low temperature contributed to a higher cytocompatibility of fabricating porous 3D architectures that provide a homogeneous distribution of cells. Immediately after the establishment of the canine TBI model, 3D-CC-ST and 3D-CC (3D-printed collagen/chitosan scaffolds) were implanted into the cavity of TBI. Following implantation of scaffolds, neurological examination and motor evoked potential detection were performed to analyze locomotor function recovery. Histological and immunofluorescence staining were performed to evaluate neuro-regeneration. The group treated with 3D-CC-ST had good performance of behavior functions. Implanting 3D-CC-ST significantly reduced the cavity area, facilitated the regeneration of nerve fibers and vessel reconstruction, and promoted endogenous neuronal differentiation and synapse formation after TBI. The implantation of 3D-CC-ST also markedly reduced cell apoptosis and regulated the level of systemic inflammatory factors after TBI.

Necrostatin-1 decreases necroptosis and inflammatory markers after intraventricular hemorrhage in mice.

Necrostatin-1, an inhibitor of necroptosis, can effectively inhibit necrotic apoptosis in neurological diseases, which results in the inhibition of inflammation, endoplasmic reticulum stress, and reactive oxygen species production and substantial improvement of neurological function. However, the effects of necrostatin-1 on intraventricular hemorrhage (IVH) remain unknown. In this study, we established a mouse model of IVH by injecting autologous blood into the lateral ventricle of the brain. We also injected necrostatin-1 into the lateral ventricle one hour prior to IVH induction. We found that necrostatin-1 effectively reduced the expression levels of the necroptosis markers receptor-interacting protein kinase (RIP)1, RIP3, mixed lineage kinase domain-like protein (MLKL), phosphorylated (p)-RIP3, and p-MLKL and the levels of interleukin-1ß , interleukin-6, and tumor necrosis factor-α in the surrounding areas of the lateral ventricle. However, necrostatin-1 did not reduce ependymal ciliary injury or brain water content. These findings suggest that necrostatin-1 can prevent local inflammation and microglial activation induced by IVH but does not greatly improve prognosis.

3D printed collagen/silk fibroin scaffolds carrying the secretome of human umbilical mesenchymal stem cells ameliorated neurological dysfunction after spinal cord injury in rats.

Although implantation of biomaterials carrying mesenchymal stem cells (MSCs) is considered as a promising strategy for ameliorating neural function after spinal cord injury (SCI), there are still some challenges including poor cell survival rate, tumorigenicity and ethics concerns. The performance of the secretome derived from MSCs was more stable, and its clinical transformation was more operable. Cytokine antibody array demonstrated that the secretome of MSCs contained 79 proteins among the 174 proteins analyzed. Three-dimensional (3D) printed collagen/silk fibroin scaffolds carrying MSCs secretome improved hindlimb locomotor function according to the Basso-Beattie-Bresnahan scores, the inclined-grid climbing test and electrophysiological analysis. Parallel with locomotor function recovery, 3D printed collagen/silk fibroin scaffolds carrying MSCs secretome could further facilitate nerve fiber regeneration, enhance remyelination and accelerate the establishment of synaptic connections at the injury site compared to 3D printed collagen/silk fibroin scaffolds alone group according to magnetic resonance imaging, diffusion tensor imaging, hematoxylin and eosin staining, Bielschowsky's silver staining, immunofluorescence staining and transmission electron microscopy. These results indicated the implantation of 3D printed collagen/silk fibroin scaffolds carrying MSCs secretome might be a potential treatment for SCI.

Synapse differentiation-induced gene 1 regulates stress-induced depression through interaction with the AMPA receptor GluA2 subunit of nucleus accumbens in male mice.

Alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptors (AMPARs) are key regulators during the process of synaptic plasticity in major depression disorder (MDD). Synapse differentiation-induced gene 1 (SynDIG1) functions as an atypical AMPAR auxiliary subunit and regulates synaptic AMPAR content; however, the role of SynDIG1 in MDD remains elusive. In this study, we found that the SynDIG1 expression was significantly increased in the neurons of the nucleus accumbens (NAc) of male mice after chronic social defeat stress (CSDS). CSDS enhanced SynDIG1-GluA2 binding and promoted the surface expression of AMPAR subunit GluA2 in the NAc. Knockdown of SynDIG1 decreased the surface expression of GluA2 and reversed the alteration of dendrite spines in the neurons, eventually alleviating the depressive-like behaviors of the stressed mice. Moreover, intra-NAc injection of IP12, a specific peptide to disrupt the interaction of SynDIG1 with GluA2, rescued depressive-like behaviors. Collectively, SynDIG1 regulates the surface expression of GluA2 and dendritic remodeling in the NAc of male mice under CSDS, thus mediating the depressive-like behaviors.

ß-hydroxybutyrate reduces reinstatement of cocaine conditioned place preference through hippocampal CaMKII-α ß-hydroxybutyrylation.

Studies have shown the therapeutic effects of a ketogenic diet (KD) on epilepsy, but the effect of a KD on drug reinstatement is largely unclear. This study aims to investigate whether KD consumption possesses therapeutic potential for cocaine reinstatement and the molecular mechanism. We find that a KD significantly reduces cocaine-induced reinstatement in mice, which is accompanied by a markedly elevated level of ß-hydroxybutyrate (ß-OHB), the most abundant ketone body, in the hippocampus. The underlying mechanism is that ß-OHB posttranslationally modifies CaMKII-α with ß-hydroxybutyrylation, resulting in significant inhibition of T286 autophosphorylation and downregulation of CaMKII activity. Collectively, our results reveal that ß-hydroxybutyrylation is a posttranslational modification of CaMKII-α that plays a critical role in mediating the effect of KD consumption in reducing cocaine reinstatement.

Inhibition of neuronal necroptosis mediated by RIP1/RIP3/MLKL provides neuroprotective effects on kaolin-induced hydrocephalus in mice.

OBJECTIVES: Necroptosis is widespread in neurodegenerative diseases. Here, we examined necroptosis in the hippocampus and cortex after hydrocephalus and found that a necroptosis pathway inhibitor alleviates necroptosis and provides neuroprotective effects. MATERIALS AND METHODS: Hydrocephalus was induced in C57BL/6 mice by kaolin. Haematoxylin and eosin (HE), Nissl, PI and Fluoro-Jade B (FJB) staining were used for general observations. Phosphorylated receptor-interacting protein kinase 3 (p-RIP3) and phosphorylated mixed lineage kinase domain-like (p-MLKL) were measured by Western blotting and immunohistochemistry. Scanning electron microscopy (SEM) was used to observe ependymal cilia. Magnetic resonance imaging (MRI) and the Morris water maze (MWM) test were used to assess neurobehavioral changes. Immunofluorescence was used to detect microglial and astrocyte activation. Inflammatory cytokines were measured by Western blotting and RT-PCR. RESULTS: Obvious pathological changes appeared in the hippocampus and cortex after hydrocephalus, and expression of the necroptosis markers p-RIP3, p-MLKL and inflammatory cytokines increased. Necrostatin-1 (Nec-1) and GSK872 reduced necrotic cell death, attenuated p-RIP3 and p-MLKL levels, slightly improved neurobehaviours and inhibited microglial and astrocyte activation and inflammation. CONCLUSIONS: RIP1/RIP3/MLKL mediates necroptosis in the cortex and hippocampus in a hydrocephalus mouse model, and Nec-1 and GSK872 have some neuroprotective effects.

Static-Dynamic Profited Viscoelastic Hydrogels for Motor-Clutch-Regulated Neurogenesis.

Viscoelasticity, a time-scale mechanical feature of the native extracellular matrix (ECM), is reported to play crucial roles in plentiful cellular behaviors, whereas its effects on neuronal behavior and the underlying molecular mechanism still remain obscure. Challenges are faced in the biocompatible synthesis of neural ECM-mimicked scaffolds solely controlled with viscoelasticity and due to the lack of suitable models for neurons-viscoelastic matrix interaction. Herein, we report difunctional hyaluronan-collagen hydrogels prepared by a static-dynamic strategy. The hydrogels show aldehyde concentration-dependent viscoelasticity and similar initial elastic modulus, fibrillar morphology, swelling as well as degradability. Utilizing the resulting hydrogels, for the first time, we demonstrate matrix viscoelasticity-dependent neuronal responses, including neurite elongation and expression of neurogenic proteins. Then, a motor-clutch model modified with a tension dissipation component is developed to account for the molecular mechanism for viscoelasticity-sensitive neuronal responses. Moreover, we prove enhanced recovery of rat spinal cord injury by implanting cell-free viscoelastic grafts. As a pioneer finding on neurons-viscoelastic matrix interaction both in vitro and in vivo, this work provides intriguing insights not only into nerve repair but also into neuroscience and tissue engineering.

Lipidomics Reveals Dysregulated Glycerophospholipid Metabolism in the Corpus Striatum of Mice Treated with Cefepime.

Cefepime exhibits a broad spectrum of antimicrobial activity and thus is a widely used treatment for severe bacterial infections. Adverse effects on the central nervous system (CNS) have been reported in patients treated with cefepime. Current explanation for the adverse neurobehavioral effect of cefepime is mainly attributed to its ability to cross the blood-brain barrier and competitively bind to the GABAergic receptor; however, the underlying mechanism is largely unknown. In this study, mice were intraperitoneally administered 80 mg/kg cefepime for different periods, followed by neurobehavioral tests and a brain lipidomic analysis. LC/MS-MS-based metabolomics was used to investigate the effect of cefepime on the brain lipidomic profile and metabolic pathways. Repeated cefepime treatment time-dependently caused anxiety-like behaviors, which were accompanied by reduced locomotor activity in the open field test. Cefepime profoundly altered the lipid profile, acyl chain length, and unsaturation of fatty acids in the corpus striatum, and glycerophospholipids accounted for a large proportion of those significantly modified lipids. In addition, cefepime treatment caused obvious alteration in the lipid-enriched membrane structure, neurites, mitochondria, and synaptic vesicles of primary cultured striatal neurons; moreover, the spontaneous electrical activity of striatal neurons was significantly reduced. Collectively, cefepime reprograms glycerophospholipid metabolism in the corpus striatum, which may interfere with neuronal structure and activity, eventually leading to aberrant neurobehaviors in mice.