Neuronal Proliferation Research Articles

Deoxynivalenol induces m6A-mediated upregulation of p21 and growth arrest of mouse hippocampal neuron cells in vitro

Hippocampal neurons maintain the ability of proliferation throughout life to support neurogenesis. Deoxynivalenol (DON) is a mycotoxin that exhibits brain toxicity, yet whether and how DON affects hippocampal neurogenesis remains unknown. Here, we use mouse hippocampal neuron cells (HT-22) as a model to illustrate the effects of DON on neuron proliferation and to explore underlying mechanisms. DON exposure significantly inhibits the proliferation of HT-22 cells, which is associated with an up-regulation of cell cycle inhibitor p21 at both mRNA and protein levels. Global and site-specific m6A methylation levels on the 3’UTR of p21 mRNA are significantly increased in response to DON treatment, whereas inhibition of m6A hypermethylation significantly alleviates DON-induced cell cycle arrest. Further mechanistic studies indicate that the m6A readers YTHDF1 and IGF2BP1 are responsible for m6A-mediated increase in p21 mRNA stability. Meanwhile, 3’UTR of E3 ubiquitin ligase TRIM21 mRNA is also m6A hypermethylated, and another m6A reader YTHDF2 binds to the m6A sites, leading to decreased TRIM21 mRNA stability. Consequently, TRIM21 suppression impairs ubiquitin-mediated p21 protein degradation. Taken together, m6A-mediated upregulation of p21, at both post-transcriptional and post-translational levels, contributes to DON-induced inhibition of hippocampal neuron proliferation. These results may provide new insights for epigenetic therapy of neurodegenerative diseases.Graphical abstractDON inhibits the proliferation of HT-22 cells.RNA m6A hypermethylation on the transcript of p21 enhances the mRNA stability in a YTHDF1- and IGF2BP1-dependent manner, which leads to the upregulation of p21.RNA m6A hypermethylation on the transcript of TRIM21 decreases the mRNA stability in a YTHDF2-dependent manner, which contributes to prevent p21 ubiquitin-mediated degradation.High expression of p21 contributes to inhibit cell proliferation.

Can targeting TSP-1 with gabapentin enhance survival in glioblastoma? A 20-year retrospective cohort study.

2048 Background: Molecularly-defined cellular subpopulations of glioblastoma secrete high levels of the synaptogenic protein thrombospondin-1 (TSP-1) which promotes functional integration of tumor into neural circuity. A greater extent of glioma-neuronal crosstalk portends worse survival for patients. In preclinical studies, gabapentin was shown to inhibit TSP-1, in turn disrupting neuronal synaptogenesis and neuronal activity-dependent glioblastoma proliferation; however, clinical survival data is lacking. We aim to determine whether treatment with gabapentin is associated with improved survival and reduced serum TSP-1 in a retrospective cohort of patients with IDH-wildtype glioblastoma. Methods: Newly-diagnosed, IDH-wildtype glioblastoma patients who received care at the UCSF Brain Tumor Center between 1997-2017 were included in this study. Kaplan-Meier curves and multivariate Cox proportional-hazards models, controlled for age, MGMT promoter methylation status, preoperative tumor volume, and extent of resection, were used for survival analyses. Differences in serum TSP-1 measured by ELISA for gabapentin treated patients and matched non-gabapentin treated controls were assessed using unpaired two-tailed student’s t-test. Control samples were matched 2:1 by age, tumor volume, and extent of resection. After 2005, patients were treated with chemoradiation with concurrent and adjuvant temodar. Results: Among 379 adult patients with glioblastoma, 36 (9.5%) were treated with gabapentin. The median daily dose of gabapentin was 600 mg (IQR: 300-900 mg). There were no significant differences between gabapentin treated and non-gabapentin treated patients by age (0.06), sex (p=0.14), or race (p=0.52). Median overall survival for gabapentin treated and non-gabapentin treated patients was 20.8 months (IQR: 11.7 - 32.1) and 14.7 months (IQR: 8.9-23.5), respectively (p= 0.02). On Kaplan-Meier survival analysis, overall survival was longer for gabapentin treated patients compared with non-gabapentin treated patients (p=0.005). In the multivariate Cox proportional-hazards model, gabapentin use was associated with decreased hazard of death (HR 0.67, p=0.030). Mean serum TSP-1 in gabapentin-treated patients was significantly lower than in the matched control group (10181 ng/ml vs 17015 ng/ml, p=0.017). Conclusions: Gabapentin use is associated with a survival benefit for patients with glioblastoma, possibly mediated through a reduction in TSP-1. This promising result lays the foundation for future prospective studies to further evaluate TSP-1 as a circulating prognostic biomarker as well as to explore the therapeutic benefits of gabapentin as a life-prolonging treatment for patients with newly diagnosed glioblastoma.

Notoginseng leaf triterpenes promotes angiogenesis by activating the Nrf2 pathway and AMPK/SIRT1-mediated PGC-1/ERα axis in ischemic stroke

Notoginseng leaf triterpenes (PNGL), derived from the dried stems and leaves of P. notoginseng, is a phytoestrogen that exerts many neuroprotective effects in vivo and in vitro of ischemic stroke. However, its impact on neurological restoration specifically in relation to angiogenesis following ischemic stroke remains unexplored. The aim of this study was to assess the effects of PNGL on angiogenesis subsequent to ischemic stroke. Male Sprague-Dawley rats were utilized in this study and were subjected to middle cerebral artery occlusion/reperfusion (MCAO/R). Post-ischemia, PNGL were administered through intraperitoneal (i.p.) injection. The high-performance liquid chromatography (HPLC) fingerprinting, triphenyltetrazolium chloride (TTC) staining, immunofluorescent staining, network pharmacology and western blot analyses were assessed to determine the therapeutical effect and molecular mechanisms of PNGL on cerebral ischemia/reperfusion injury. Our findings demonstrate that PNGL effectively reduced infarct volume, enhanced cerebral blood flow, and induced angiogenesis in rats subjected to MCAO/R. Notably, PNGL also facilitated neuronal proliferation and migration in HUMECs in vitro. The proangiogenic effects of PNGL were found to be linked to the activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway and the AMPK/SIRT1-mediated PGC-1/ERα axis, as well as the activation of neurological function. Our study provides evidence that PNGL hold promise as an active ingredient of inducing proangiogenic effects, potentially through the activation of the Nrf2 pathway and the AMPK/SIRT1-mediated PGC-1/ERα axis. These findings contribute to the understanding of novel mechanisms involved in the restoration of neurological function following PNGL treatment for ischemic stroke.

Pin1 Downregulation Is Involved in Excess Retinoic Acid-Induced Failure of Neural Tube Closure.

Neural tube defects (NTDs), which are caused by impaired embryonic neural tube closure, are one of the most serious and common birth defects. Peptidyl-prolyl cis/trans isomerase 1 (Pin1) is a prolyl isomerase that uniquely regulates cell signaling by manipulating protein conformation following phosphorylation, although its involvement in neuronal development remains unknown. In this study, we explored the involvement of Pin1 in NTDs and its potential mechanisms both in vitro and in vivo. The levels of Pin1 expression were reduced in NTD models induced by all-trans retinoic acid (Atra). Pin1 plays a significant role in regulating the apoptosis, proliferation, differentiation, and migration of neurons. Moreover, Pin1 knockdown significantly was found to exacerbate oxidative stress (OS) and endoplasmic reticulum stress (ERs) in neuronal cells. Further studies showed that the Notch1-Nrf2 signaling pathway may participate in Pin1 regulation of NTDs, as evidenced by the inhibition and overexpression of the Notch1-Nrf2 pathway. In addition, immunofluorescence (IF), co-immunoprecipitation (Co-IP), and GST pull-down experiments also showed that Pin1 interacts directly with Notch1 and Nrf2. Thus, our study suggested that the knocking down of Pin1 promotes NTD progression by inhibiting the activation of the Notch1-Nrf2 signaling pathway, and it is possible that this effect is achieved by disrupting the interaction of Pin1 with Notch1 and Nrf2, affecting their proteostasis. Our research identified that the regulation of Pin1 by retinoic acid (RA) and its involvement in the development of NTDs through the Notch1-Nrf2 axis could enhance our comprehension of the mechanism behind RA-induced brain abnormalities.

Megalencephaly: Classification, Genetic Causes, and Related Syndromes

AbstractMegalencephaly is a developmental disorder due to an abnormal neuronal proliferation and migration during intrauterine or postnatal brain development that leads to cerebral overgrowth and neurological dysfunction. This cerebral overgrowth may affect the whole encephalon or only a region; when it involves one hemisphere it is referred to as hemimegalencephaly. Megalencephaly presents with a head circumference measurement of 2 standard deviations above the average measure for age. This group of disorders is clinically characterized by early onset and refractory to therapy epilepsy, neurodevelopmental disorders, behavioral problems, and autism spectrum disorder. Syndromic forms of megalencephaly should be considered when associated with other congenital abnormalities. Megalencephaly in fact could be associated with segmental overgrowth and cutaneous/vascular abnormalities (i.e., Proteus syndrome, CLOVES [congenital lipomatous overgrowth, vascular malformations, epidermal naevi, scoliosis, and/ or skeletal abnormalities] syndrome, Klippel-Trenaunay syndrome, megalencephaly-capillary malformation-polymicrogyria syndrome , megalencephaly-postaxial polydactyly-polymicrogyria-hydrocephalus syndrome, etc.) or generalized overgrowth (i.e., Weaver or Beckwith-Wiedemann syndrome) as well as with nanism in achondroplasia where megalencephaly is associated with disproportionate short stature, primary skeletal dysplasia, characteristic facies (prominent forehead, flat nasal bridge), narrow chest, and normal intelligence. It is possible to identify three main groups of disorders associated with megalencephaly: idiopathic or benign, metabolic, and anatomic. The idiopathic (benign) form indicates an abnormal increased head circumference in absence of neurological impairment, such as in benign familial megalencephaly. In metabolic megalencephaly (such as in organic acid disorders, metabolic leukoencephalopathies, or lysosomal diseases) there is an increase of different constituents that increase the size of the brain, whereas in the anatomical form there are underlying genetic causes. Neuroimaging is crucial for diagnosis, as it can reveal a generalized brain growth or a segmental one and possible specific frameworks associated. In all these conditions it is necessary to identify possible microdeletion-microduplication by chromosomal arrays.

Naringenin mitigates aluminum toxicity-induced learning memory impairments and neurodegeneration through amelioration of oxidative stress.

Aluminum chloride (AlCl3) is a potent neurotoxic substance known to cause memory impairment and oxidative stress-dependent neurodegeneration. Naringenin (NAR) is a dietary flavonoid with potent antioxidant and anti-inflammatory properties which was implemented against AlCl3-induced neurotoxicity to ascertain its neuroprotective efficacy. Experimental neurotoxicity in mice was induced by exposure of AlCl3 (10 mg/kg, p.o.) followed by treatment with NAR (10 mg/kg, p.o.) for a total of 63 days. Assessed the morphometric, learning memory dysfunction (novel object recognition, T- and Y-maze tests), neuronal oxidative stress, and histopathological alteration in different regions of the brain, mainly cortex, hippocampus, thalamus, and cerebellum. AlCl3 significantly suppressed the spatial learning and memory power which were notably improved by administration of NAR. The levels of oxidative stress parameters nitric oxide, advanced oxidation of protein products, protein carbonylation, lipid peroxidation, superoxide dismutase, catalase, glutathione reductase, reduced glutathione, and the activity of acetylcholine esterase were altered 1.5-3 folds by AlCl3 significantly. Treatment of NAR remarkably restored the level of oxidative stress parameters and maintained the antioxidant defense system. AlCl3 suppressed the expression of neuronal proliferation marker NeuN that was restored by NAR treatment which may be a plausible mechanism. NAR showed therapeutic efficacy as a natural supplement against aluminum-intoxicated memory impairments and histopathological alteration through a mechanism involving an antioxidant defense system and neuronal proliferation.

Can the HB-EGF/EGFR pathway restore injured neurons?

Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a transmembrane protein that, when cleaved by metalloproteases through a process called ectodomain shedding, binds to the EGF receptor (EGFR), activating downstream signaling. The HB-EGF/EGFR pathway is crucial in development and is involved in numerous pathophysiological processes. In this issue of The FEBS Journal, Sireci etal. reveal a previously unexplored function of the HB-EGF/EGFR pathway in promoting neuronal progenitor proliferation and sensory neuron regeneration in the zebrafish olfactory epithelium in response to injury.

Impact of metformin on neocortical development during pregnancy: Involvement of ERK and p35/CDK5 pathways

Metformin, the most commonly prescribed drug for the treatment of diabetes, is increasingly used during pregnancy to address various disorders such as diabetes, obesity, preeclampsia, and metabolic diseases. However, its impact on neocortex development remains unclear. Here, we investigated the direct effects of metformin on neocortex development, focusing on ERK and p35/CDK5 regulation. Using a pregnant rat model, we found that metformin treatment during pregnancy induces small for gestational age (SGA) and reduces relative cortical thickness in embryos and neonates. Additionally, we discovered that metformin inhibits neural progenitor cell proliferation in the sub-ventricular zone (SVZ)/ventricular zone (VZ) of the developing neocortex, a process possibly mediated by ERK inactivation. Furthermore, metformin induces neuronal apoptosis in the SVZ/VZ area of the developing neocortex. Moreover, metformin retards neuronal migration, cortical lamination, and differentiation, potentially through p35/CDK5 inhibition in the developing neocortex. Remarkably, compensating for p35 through in utero electroporation partially rescues metformin-impaired neuronal migration and development. In summary, our study reveals that metformin disrupts neocortex development by inhibiting neuronal progenitor proliferation, neuronal migration, cortical layering, and cortical neuron maturation, likely via ERK and p35/CDK5 inhibition. Consequently, our findings advocate for caution in metformin usage during pregnancy, given its potential adverse effects on fetal brain development.

Microglial exosomes in paraquat-induced Parkinson's disease: Neuroprotection and biomarker clues

The exact mechanisms underlying the initiation and exacerbation of Parkinson's disease (PD) by paraquat remain unclear. We have revealed that exosomes mediate neurotoxicity induced by low dose paraquat exposure by transmitting intercellular signaling. Exposure to 40 μM paraquat promoted exosome release from mouse microglia cells (BV2) in vitro. Paraquat exposure at 100 μM caused degeneration of mouse dopaminergic MN9D cells and inhibited microglia exosome uptake by fluorescently labeling exosomes. We established an incubation model for exosomes and dopaminergic neuron cells under PQ treatment. The results indicated that microglial exosomes alleviated degeneration, increasing proliferation and PD-related protein expression of dopaminergic neurons; however, paraquat reversed this effect. Then, through exosome high-throughput sequencing and qRT-PCR experiments, miR-92a-3p and miR-24-3p were observed to transfer from exosomes to dopaminergic neurons, inhibited by paraquat. The specificity of miR-92a-3p and miR-24-3p was verified in PD patients exosomes, indicating the potential diagnostic value of the exosomal miRNAs in paraquat-induced PD. These results suggest glia-neuron communication in paraquat-induced neurodegeneration and may identify stable paraquat-mediated PD biomarkers, offering clues for early recognition and prevention of pesticide-induced degenerative diseases.

Effects of nanomolar methylmercury on developing human neural stem cells and zebrafish Embryo

Exposure to mercury and its organic form methylmercury (MeHg), is of great concern for the developing nervous system. Despite available literature on MeHg neurotoxicity, there is still uncertainty about its mechanisms of action and the doses that trigger developmental effects. Our study combines two alternative methodologies, the human neural stem cells (NSC) and the zebrafish (ZF) embryo, to address the neurotoxic effects of early exposure to nanomolar concentrations of MeHg. Our results show linear or nonmonotonic (hormetic) responses depending on studied parameters. In ZF, we observed a hormetic response in locomotion and larval rotation, but a concentration-dependent response for sensory organ size and habituation. We also observed a possible delayed response as MeHg had greater effects on larval activity at 5 days than at 24 h. In NSC cells, some parameters show a clear dose dependence, such as increased apoptosis and differentiation to glial cells or decreased neuronal precursors; while others show a hormetic response: neuronal differentiation or cell proliferation. This study shows that the ZF model was more susceptible than NSC to MeHg neurotoxicity. The combination of different models has improved the understanding of the underlying mechanisms of toxicity and possible compensatory mechanisms at the cellular and organismal level.

The effects of nutrient-induced quiescence on neural stem cell proliferation in the Drosophila central brain

In the fruit fly, neural stem cells (neuroblasts) residing within a specialized brain niche divide throughout development to produce the adult CNS. Neuroblasts normally transition between a proliferative or quiescent state during development, and this balance is critical for proper tissue growth and neuron production. NBs enter quiescence at the end of embryogenesis when maternal nutrient stores are depleted and reactivate proliferation soon after freshly hatched larvae consume their first meal. This reactivation is regulated by a nutritional checkpoint that requires dietary amino acids. Neuroblasts in larvae maintained on a diet lacking amino acids halt proliferation and production of neurons for extended periods of time, and this state is reversible after reintroduction of amino acids to their diet. Presumably this developmental plasticity is an adaptation that allows mobile larvae to secure another nutrient source, but the extent to which such a delay affects the structure and function of the adult CNS has not been investigated. We used our previously established nutrient deprivation model to halt neuroblast proliferation in larvae for a prolonged period. Using confocal microscopy, we measured the effect of this treatment on both the number of mitotic neuroblasts and how many daughter cells they produced. Both measures of neuroblast proliferation were reduced in delayed larvae compared to controls, despite having access to dietary nutrients for the same amount of time. These results elucidate an uninvestigated aspect of plasticity in the developing CNS and lay the foundation for further functional study of adult brains.

Bisphenol-F and Bisphenol-S (BPF and BPS) Impair the Stemness of Neural Stem Cells and Neuronal Fate Decision in the Hippocampus Leading to Cognitive Dysfunctions.

Neurogenesis occurs throughout life in the hippocampus of the brain, and many environmental toxicants inhibit neural stem cell (NSC) function and neuronal generation. Bisphenol-A (BPA), an endocrine disrupter used for surface coating of plastic products causes injury in the developing and adult brain; thus, many countries have banned its usage in plastic consumer products. BPA analogs/alternatives such as bisphenol-F (BPF) and bisphenol-S (BPS) may also cause neurotoxicity; however, their effects on neurogenesis are still not known. We studied the effects of BPF and BPS exposure from gestational day 6 to postnatal day 21 on neurogenesis. We found that exposure to non-cytotoxic concentrations of BPF and BPS significantly decreased the number/size of neurospheres, BrdU+ (proliferating NSC marker)and MAP-2+ (neuronal marker) cells and GFAP+ astrocytes in the hippocampus NSC culture, suggesting reduced NSC stemness and self-renewal and neuronal differentiation and increased gliogenesis. These analogs also reduced the number of BrdU/Sox-2+, BrdU/Dcx+, and BrdU/NeuN+ co-labeled cells in the hippocampus of the rat brain, suggesting decreased NSC proliferation and impaired maturation of newborn neurons. BPF and BPS treatment increases BrdU/cleaved caspase-3+ cells and Bax-2 and cleaved caspase protein levels, leading to increased apoptosis in hippocampal NSCs. Transmission electron microscopy studies suggest that BPF and BPS also caused degeneration of neuronal myelin sheath, altered mitochondrial morphology, and reduced number of synapses in the hippocampus leading to altered cognitive functions. These results suggest that BPF and BPS exposure decreased the NSC pool, inhibited neurogenesis, induced apoptosis of NSCs, caused myelin degeneration/synapse degeneration, and impaired learning and memory in rats.

Thrombopoietin exerts a neuroprotective effect by inhibiting the suppression of neuronal proliferation and axonal outgrowth in intrauterine growth restriction rats

Chronic hypoxia in utero causes intrauterine growth restriction (IUGR) of the fetus. IUGR infants are known to be at higher risk for neurodevelopmental disorders, but the mechanism is unclear. In this study, we analyzed the structure of the cerebral cortex using IUGR model rats generated through a reduced uterine perfusion pressure operation. IUGR rats exhibited thinner cerebral white matter and enlarged lateral ventricles compared with control rats. Expression of neuron cell markers, Satb2, microtubule-associated protein (MAP)-2, α-tubulin, and nestin was reduced in IUGR rats, indicating that neurons were diminished at various developmental stages in IUGR rats, from neural stem cells to mature neurons. However, there was no increase in apoptosis in IUGR rats. Cells positive for Ki67, a marker of cell proliferation, were reduced in neurons and all glial cells of IUGR rats. In primary neuron cultures, axonal elongation was impaired under hypoxic culture conditions mimicking the intrauterine environment of IUGR infants. Thus, in IUGR rats, chronic hypoxia in utero suppresses the proliferation of neurons and glial cells as well as axonal elongation, resulting in cortical thinning and enlarged lateral ventricles. Thrombopoietin (TPO), a platelet growth factor, inhibited the decrease in neuron number and promoted axon elongation in primary neurons under hypoxic conditions. Intraperitoneal administration of TPO to IUGR rats resulted in increases in the number of NeuN-positive cells and the area coverage of Satb2. In conclusion, suppression of neuronal proliferation and axonal outgrowth in IUGR rats resulted in cortical thinning and enlargement of lateral ventricles. TPO administration might be a novel therapeutic strategy for treating brain dysmaturation in IUGR infants.

Enhancing Cognitive Functions and Neuronal Growth through NPY1R Agonist and Ketamine Co-Administration: Evidence for NPY1R-TrkB Heteroreceptor Complexes in Rats

This study investigates the combined effects of the neuropeptide Y Y1 receptor (NPY1R) agonist [Leu31-Pro34]NPY at a dose of 132 µg and Ketamine at 10 mg/Kg on cognitive functions and neuronal proliferation, against a backdrop where neurodegenerative diseases present an escalating challenge to global health systems. Utilizing male Sprague-Dawley rats in a physiological model, this research employed a single-dose administration of these compounds and assessed their impact 24 h after treatment on object-in-place memory tasks, alongside cellular proliferation within the dorsal hippocampus dentate gyrus. Methods such as the in situ proximity ligation assay and immunohistochemistry for proliferating a cell nuclear antigen (PCNA) and doublecortin (DCX) were utilized. The results demonstrated that co-administration significantly enhanced memory consolidation and increased neuronal proliferation, specifically neuroblasts, without affecting quiescent neural progenitors and astrocytes. These effects were mediated by the potential formation of NPY1R-TrkB heteroreceptor complexes, as suggested by receptor co-localization studies, although further investigation is required to conclusively prove this interaction. The findings also highlighted the pivotal role of brain-derived neurotrophic factor (BDNF) in mediating these effects. In conclusion, this study presents a promising avenue for enhancing cognitive functions and neuronal proliferation through the synergistic action of the NPY1R agonist and Ketamine, potentially via NPY1R-TrkB heteroreceptor complex formation, offering new insights into therapeutic strategies for neurodegenerative diseases.

Clinicopathological and molecular genetic features of Crohn's disease

Objective: To investigate the clinicopathological and molecular genetic characteristics of Crohn's disease (CD). Methods: A retrospective analysis was conducted on 52 CD patients who underwent surgical resection at the First Affiliated Hospital of Nanjing Medical University between January 2014 and June 2023. Clinical presentations and histopathological features were assessed. Whole-genome sequencing was performed on 17 of the samples, followed by sequencing and pathway enrichment analyses. Immunohistochemistry was used to assess the expression of frequently mutated genes. Results: Among the 52 patients, 34 were males and 18 were females, male-to-female ratio was 1.9∶1.0, with a median age of 45 years at surgery and 35 years at diagnosis. According to the Montreal classification, A3 (51.9%,27/52), B2 (61.5%, 32/52), and L3 (50.0%,26/52) subtypes were the most predominant. Abdominal pain and diarrhea were the common symptoms. Histopathological features seen in all 52 patients included transmural inflammation, disruption of cryptal architecture, lymphoplasmacytic infiltration, varying degrees of submucosal fibrosis and thickening, increased enteric nerve fibers and neuronal proliferation. Mucosal defects, fissure ulcers, abscesses, pseudopolyps, and adenomatous proliferation were also observed in 51 (98.1%), 38 (73.1%), 28 (53.8%), 45 (86.5%), and 28 (53.8%) cases, respectively. Thirty-one (59.6%) cases had non-caseating granulomas, and 3 (5.8%) cases had intestinal mucosal glandular epithelial dysplasia. Molecular analysis showed that 12/17 CD patients exhibited mutations in at least one mucin family gene (MUC2, MUC3A, MUC4, MUC6, MUC12, MUC17), and MUC4 was the most frequently mutated in 7/17 of cases. Immunohistochemical stains showed reduced MUC4 expression in epithelial cells, with increased MUC4 expression in the epithelial surface, particularly around areas of inflammatory cell aggregation; and minimal expression in the lower half of the epithelium. Conclusions: CD exhibits diverse clinical and pathological features, necessitating a comprehensive multidimensional analysis for diagnosis. Mutations and expression alterations in mucin family genes, particularly MUC4, may play crucial roles in the pathogenesis of CD.

Inhibition of DAPK3 Suppresses Radiation-Induced Cellular Senescence by Activation of a PGC1α-Dependent Metabolism Pathway in Brain Endothelial Cells.

In the brain, environmental changes, such as neuroinflammation, can induce senescence, characterized by the decreased proliferation of neurons and dendrites and synaptic and vascular damage, resulting in cognitive decline. Senescence promotes neuroinflammatory disorders by senescence-associated secretory phenotypes and reactive oxygen species. In human brain microvascular endothelial cells (HBMVECs), we demonstrate that chronological aging and irradiation increase death-associated protein kinase 3 (DAPK3) expression. To confirm the role of DAPK3 in HBMVEC senescence, we disrupted DAPK3 activity using small interfering RNA (siRNA) or a dominant-negative mutant (DAPK3-P216S), which reduced cellular senescence phenotypes, as assessed by changes in tube formation, senescence-associated beta-galactosidase activity, and cell proliferation. In endothelial cells, DAPK3 promotes cellular senescence by regulating the phosphorylation and inactivation of peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1α) via the protein kinase B pathway, resulting in the decreased expression of mitochondrial metabolism-associated genes, such as ATP5G1, BDNF, and COX5A. Our studies show that DAPK3 is involved in cellular senescence and PGC1α regulation, suggesting that DAPK3 regulation may be important for treating aging-related brain diseases or the response to radiation therapy.

Evaluate the in vitro effect of anthracycline and alkylating cytophosphane chemotherapeutics on dopaminergic neurons.

Iatrogenesis is an inevitable global threat to healthcare that drastically increases morbidity and mortality. Cancer is a fatal pathological condition that affects people of different ages, sexes, and races around the world. In addition to the detrimental cancer pathology, one of the most common contraindications and challenges observed in cancer patients is severe adverse drug effects and hypersensitivity reactions induced by chemotherapy. Chemotherapy-induced cognitive neurotoxicity is clinically referred to as Chemotherapy-induced cognitive impairment (CICI), chemobrain, or chemofog. In addition to CICI, chemotherapy also causes neuropsychiatric issues, mental disorders, hyperarousal states, and movement disorders. A synergistic chemotherapy regimen of Doxorubicin (Anthracycline-DOX) and Cyclophosphamide (Alkylating Cytophosphane-CPS) is indicated for the management of various cancers (breast cancer, lymphoma, and leukemia). Nevertheless, there are limited research studies on Doxorubicin and Cyclophosphamide's pharmacodynamic and toxicological effects on dopaminergic neuronal function. This study evaluated the dopaminergic neurotoxic effects of Doxorubicin and Cyclophosphamide. Doxorubicin and Cyclophosphamide were incubated with dopaminergic (N27) neurons. Neuronal viability was assessed using an MTT assay. The effect of Doxorubicin and Cyclophosphamide on various prooxidants, antioxidants, mitochondrial Complex-I & IV activities, and BAX expression were evaluated by Spectroscopic, Fluorometric, and RT-PCR methods, respectively. Prism-V software (La Jolla, CA, USA) was used for statistical analysis. Chemotherapeutics dose-dependently inhibited the proliferation of the dopaminergic neurons. The dopaminergic neurotoxic mechanism of Doxorubicin and Cyclophosphamide was attributed to a significant increase in prooxidants, a decrease in antioxidants, and augmented apoptosis without affecting mitochondrial function. This is one of the first reports that reveal Doxorubicin and Cyclophosphamide induce significant dopaminergic neurotoxicity. Thus, Chemotherapy-induced adverse drug reaction issues substantially persist during and after treatment and sometimes never be completely resolved clinically. Consequently, failure to adopt adequate patient care measures for cancer patients treated with certain chemotherapeutics might substantially raise the incidence of numerous movement disorders.

Proteomic analysis of blood serum in bipolar disorder

IntroductionBipolar disorder (BD) often has symptoms similar to other mental disorders (BD), and there are no paraclinical criteria for differential diagnosis. (Geoffroy et al. Bip Dis 2017; 5 7). Published work on MD proteomics is scarce and focused on schizophrenia. (Dmitrieva et al. PeerJ. 2022; 10 e13907). Therefore, it is important to study potential biomarkers of BD using easily accessible material—blood serum (Rhee et al. Transl Psy 2023; 13 44). Identification of proteins involved in the pathogenesis of BD will help in the study of the pathogenetic mechanisms of BD, the development of differential diagnostic methods and pathogenetically based drugs.ObjectivesCarrying out a comparative proteomic analysis of blood serum from patients with BD and healthy individuals to identify potential biomarkersMethodsWe analyzed the protein spectrum of the blood serum of 14 patients with BD who were admitted during a depressive episode at the age of 32 [21;52] years with a disease duration of 8[5;11] years. The control group consisted of 10 mentally and somatically healthy individuals corresponding to the gender and age of the BD group. Blood serum was purified from 14 major proteins using affinity chromatography and separated by electrophoresis using the Laemmli method. After trypsinolysis, proteins were identified using HPLC/mass spectrometry on an Orbitrap instrument. Mass spectrometric analysis was performed on the Advanced Mass Spectrometry Core Facility of Skolkovo Institute of Science and Technology. Protein identification was carried out using the UniProtKB database using the Mascot search engine. The results were tested for significance using the nonparametric Fisher exact test with Yates correction.ResultsIn patients with BD, qualitative mass spectrometry revealed differential expression of 21 neurospecific proteins. Among them: Protein dispatched homolog 3, Ceroid-lipofuscinosis neuronal protein 6, SWI/SNF complex subunit SMARCC1, Neurogenic differentiation factor 4, Protein furry homolog-like, REST corepressor 1 – are involved in the proliferation, development and differentiation of neurons; Hemicentin-2, Dystrophin, Voltage-dependent L-type calcium channel subunit alpha-1D, Syntaxin-binding protein 5, Small conductance calcium-activated potassium channel protein 1– participate in synaptic transmission of ion transport and form receptors.ConclusionsStudying the role of these proteins in BD and their quantitative content in a larger number of patients is promising. This will help in the development of new diagnostic criteria and targets for drug therapy for BD.Support by the Russian Science Foundation grant No. 23-75-00023.Disclosure of InterestNone Declared

A role for Retinoblastoma 1 in hindbrain morphogenesis by regulating GBX family

The hindbrain, which develops from the anterior end of the neural tube expansion, can differentiate into the metencephalon and myelencephalon, with varying sizes and functions. The midbrain–hindbrain boundary (MHB) and hindbrain myelencephalon/ventral midline (HMVM) are known to be the source of the progenitors for the anterior hindbrain and myelencephalon, respectively. However, the molecular networks regulating hindbrain morphogenesis in these structures remain unclear. In this study, we show that retinoblastoma 1 (rb1) is highly expressed at the MHB and HMVM in zebrafish. Knocking out rb1 in mice and zebrafish results in an enlarged hindbrain due to hindbrain neuronal hyperproliferation. Further study reveals that Rb1 controls the hindbrain morphogenesis by suppressing the expression of Gbx1/Gbx2, essential transcription factors for hindbrain development, through its binding to E2f3/Hdac1, respectively. Interestingly, we find that Gbx1 and Gbx2 are expressed in different types of hindbrain neurons, suggesting distinct roles in hindbrain morphogenesis. In summary, our study clarifies the specific role of RB1 in hindbrain neural cell proliferation and morphogenesis by regulating the E2f3–Gbx1 axis and the Hdac1–Gbx2 axis. These findings provide a research paradigm for exploring the differential proliferation of neurons in various brain regions.

Cannabinoid type 2 receptor inhibition enhances the antidepressant and proneurogenic effects of physical exercise after chronic stress

Chronic stress is a major risk factor for neuropsychiatric conditions such as depression. Adult hippocampal neurogenesis (AHN) has emerged as a promising target to counteract stress-related disorders given the ability of newborn neurons to facilitate endogenous plasticity. Recent data sheds light on the interaction between cannabinoids and neurotrophic factors underlying the regulation of AHN, with important effects on cognitive plasticity and emotional flexibility. Since physical exercise (PE) is known to enhance neurotrophic factor levels, we hypothesised that PE could engage with cannabinoids to influence AHN and that this would result in beneficial effects under stressful conditions. We therefore investigated the actions of modulating cannabinoid type 2 receptors (CB2R), which are devoid of psychotropic effects, in combination with PE in chronically stressed animals. We found that CB2R inhibition, but not CB2R activation, in combination with PE significantly ameliorated stress-evoked emotional changes and cognitive deficits. Importantly, this combined strategy critically shaped stress-induced changes in AHN dynamics, leading to a significant increase in the rates of cell proliferation and differentiation of newborn neurons, overall reduction in neuroinflammation, and increased hippocampal levels of BDNF. Together, these results show that CB2Rs are crucial regulators of the beneficial effects of PE in countering the effects of chronic stress. Our work emphasises the importance of understanding the mechanisms behind the actions of cannabinoids and PE and provides a framework for future therapeutic strategies to treat stress-related disorders that capitalise on lifestyle interventions complemented with endocannabinoid pharmacomodulation.