Leptin Promotes the Proliferation and Neuronal Differentiation of Neural Stem Cells through the Cooperative Action of MAPK/ERK1/2, JAK2/STAT3 and PI3K/AKT Signaling Pathways.

The potential of neural stem cells (NSCs) for neurological disorders the treatment has relied in large part upon identifying the NSCs fate decision. The hormone leptin has been reported to be a crucial regulator of brain development, able to influence the glial and neural development, yet, the underlying mechanism of leptin acting on NSCs' biological characteristics is still poorly understood. This study aims to investigate the role of leptin in the biological properties of NSCs. In this study, we investigate the possibility that leptin may regulate the NSCs' fate decision, which may promote the proliferation and neuronal differentiation of NSCs and thus act positively in neurological disorders. NSCs from the embryonic cerebral cortex were used in this study. We used CCK-8 assay, ki67 immunostaining, and FACS analysis to confirm that 25-100 ng/mL leptin promotes the proliferation of NSCs in a concentration-dependent pattern. This change was accompanied by the upregulation of p-AKT and p-ERK1/2, which are the classical downstream signaling pathways of leptin receptors b (LepRb). Inhibition of PI3K/AKT or MAPK/ERK signaling pathways both abolished the effect of leptin-induced proliferation. Moreover, leptin also enhanced the directed neuronal differentiation of NSCs. A blockade of the PI3K/AKT pathway reversed leptin-stimulated neurogenesis, while a blockade of JAK2/STAT3 had no effect on it. Taken together, our results support a role for leptin in regulating the fate of NSCs differentiation and promoting NSCs proliferation, which could be a promising approach for brain repair via regulating the biological characteristics of NSCs.

Voluntary Exercise to Reduce Anxiety Behaviour in Traumatic Brain Injury Shown to Alleviate Inflammatory Brain Response in Mice.

Traumatic brain injury is a leading cause of neuroinflammation and anxiety disorders in young adults. Immune-targeted therapies have garnered attention for the amelioration of TBI-induced anxiety. A previous study has indicated that voluntary exercise intervention following TBI could reduce neuroinflammation. It is essential to determine the effects of voluntary exercise after TBI on anxiety via inhibiting neuroinflammatory response. Mice were randomly divided into four groups (sham, TBI, sham + voluntary wheel running (VWR), and TBI + VWR). One-week VWR was carried out on the 2nd day after trauma. The neurofunction of TBI mice was assessed. Following VWR, anxiety behavior was evaluated, and neuroinflammatory responses in the perilesional cortex were investigated. Results showed that after one week of VWR, neurofunctional recovery was enhanced, while the anxiety behavior of TBI mice was significantly alleviated. The level of pro-inflammatory factors decreased, and the level of anti-inflammatory factors elevated. Activation of nucleotide oligomerization domain-like thermal receptor protein domain associated protein 3 (NLRP3) inflammasome was inhibited significantly. All these alterations were consistent with reduced microglial activation at the perilesional site and positively correlated with the amelioration of anxiety behavior. This suggested that timely rehabilitative exercise could be a useful therapeutic strategy for anxiety resulting from TBI by targeting neuroinflammation.

The kinase inhibitory region of SOCS3 attenuates reactive astrogliosis and astroglial scar in mice after traumatic brain injury.

Traumatic brain injury (TBI) leads to reactive astrogliosis that impedes neural repair/regeneration. It has been proven that SOCS3 attenuates astrocyte activation by inhibiting the JAK2-STAT3 pathway. However, whether the kinase inhibitory region (KIR) of SOCS3 can be directly applied to mediate astrocyte activation after TBI is not clear. The present study aimed at investigating the inhibitory effect of KIR on reactive astrogliosis and its potential neuroprotection after TBI insult. For this purpose, A TBI model was developed by the free impact of heavy objects in adult mice. KIR was linked to the TAT peptide (TAT-KIR) to facilitate cell membrane penetration and intracranially injected into the cerebral cortex adjacent to the TBI lesion. Then reactive astrogliosis, activity of JAK2-STAT3 pathway, neuron loss, and function deficit were observed. Our results showed a decrease in neuron loss and an improvement in neural function. Meanwhile, Intracranial injection of TAT-KIR in TBI mice demonstrated a reduction of GFAP-positive astrocytes as well as C3/GFAP double-labeled A1 reactive astrocytes. Western blot analysis illustrated that the activity of the JAK2-STAT3 pathway was significantly inhibited by TAT-KIR. We conclude that exogenous treatment TAT-KIR, through suppression of JAK2-STAT3 activity, inhibits TBI -induced reactive astrogliosis induced, thereby alleviating the loss of neurons and relieving the neural function deficit. This investigation suggests that TAT-KIR could be a potential therapeutic strategy for enhancing neural regeneration following.

Development of a classification model and an immune-related network based on ferroptosis in periodontitis.

BACKGROUND AND OBJECTIVES: Periodontitis is an immunoinflammatory disease characterized by irreversible periodontal attachment loss and bone destruction. Ferroptosis is a kind of immunogenic cell death that depends on the participation of iron ions and is involved in various inflammatory and immune processes. However, information regarding the relationship between ferroptosis and immunomodulation processes in periodontitis is extremely limited. The purpose of this study was to investigate the correlation between ferroptosis and immune responses in periodontitis. METHODS: Gene expression profiles of gingivae were collected from the Gene Expression Omnibus data portal. After detecting differentially expressed ferroptosis-related genes (FRGs), we used univariate logistic regression analysis followed by logistic least absolute shrinkage and selection operator (LASSO) regression to establish a ferroptosis-related classification model in an attempt to accurately distinguish periodontitis gingival tissues from healthy samples. The infiltration level of immunocytes in periodontitis was then assessed through single-sample gene-set enrichment analysis. Subsequently, we screened out immune-related genes by weighted correlation network analysis and protein-protein interaction (PPI) analysis and constructed an immune-related network based on FRGs and immune-related genes. RESULTS: A total of 24 differentially expressed FRGs were detected, and an 8-FRG combined signature constituted the classification model. The established model showed outstanding discriminating ability according to the results of receiver operating characteristic (ROC) curve analysis. In addition, the periodontitis samples had a higher degree of immunocyte infiltration. Activated B cells had the strongest positive correlation while macrophages had a strong negative correlation with certain FRGs, and we found that XBP1, ALOX5 and their interacting genes might be crucial genes in the immune-related network. CONCLUSIONS: The FRG-based classification model had a satisfactory determination ability, which could bring new insights into the pathogenesis of periodontitis. Those genes in the immune-related network, especially hub genes along with XBP1 and ALOX5, would have the potential to serve as promising targets of immunomodulatory treatments for periodontitis.

Kinase inhibit region of SOCS3 attenuates IL6-induced proliferation and astrocytic differentiation of neural stem cells via cross talk between signaling pathways.

AIMS: Efficiency of neural stem cells (NSCs) therapy for brain injury is restricted by astrogliosis around the damaged region, in which JAK2/STAT3 signaling plays a key role. The SOCS3 that can directly inhibit JAK/STAT3 pathway. Here, we investigated the effects of a fusion peptide that combined kinase inhibitory region (KIR) of SOCS3 and virus trans-activator of transcription (TAT) on biological behavior of cultured NSCs under inflammatory conditions. METHODS: NSCs were isolated from embryonic brain of SD rats, TAT-KIR was synthesized, and penetration rate was evaluated by flow cytometry (FACS). CCK8, immunostaining, and FACS were used to detected of TAT-KIR on the proliferation of NSCs. The expressions of GFAP and ß tubulin III positive cells induced by IL6 with/without TAT-KIR were examined by immunostaining and Western blotting to observe the NSCs differentiation, and the effect of TAT-KIR on signaling cross talk was observed by Western blotting. RESULTS: Penetration rate of TAT-KIR into primary cultured NSCs was up to 94%. TAT-KIR did not affect the growth and viability of NSCs. It significantly reduced the NSCs proliferation that enhanced by IL-6 stimulation via blocking the cell cycle progression from the G0/G1 to S phase. In addition, TAT-KIR attenuated astrocytic differentiation and kept high level of neuronal differentiation derived from IL-6-induced NSCs. The fate of NSCs differentiation under inflammatory conditions was affected by TAT-KIR, which was associated with synchronous inhibition of STAT3 and AKT, while promoting JNK expression. CONCLUSION: TAT-KIR mimetic of SOCS3 could be a promising approach for brain repair via regulating the biological behaviors of exogenous NSCs.

Maternal High-Fat Diet Reduces Type-2 Neural Stem Cells and Promotes Premature Neuronal Differentiation during Early Postnatal Development.

Maternal obesity or exposure to a high-fat diet (HFD) has an irreversible impact on the structural and functional development of offspring brains. This study aimed to investigate whether maternal HFD during pregnancy and lactation impairs dentate gyrus (DG) neurogenesis in offspring by altering neural stem cells (NSCs) behaviors. Pregnant Sprague-Dawley rats were fed a chow diet (CHD) or HFD (60% fat) during gestation and lactation. Pups were collected on postnatal day 1 (PND 1), PND 10 and PND 21. Changes in offspring body weight, brain structure and granular cell layer (GCL) thickness in the hippocampus were analyzed. Hippocampal NSCs behaviors, in terms of proliferation and differentiation, were investigated after immunohistochemical staining with Nestin, Ki67, SOX2, Doublecortin (DCX) and NeuN. Maternal HFD accelerated body weight gain and brain structural development in offspring after birth. It also reduced the number of NSCs and their proliferation, leading to a decrease in NSCs pool size. Furthermore, maternal HFD intensified NSCs depletion and promoted neuronal differentiation in the early postnatal development period. These findings suggest that maternal HFD intake significantly reduced the amount and capability of NSCs via reducing type-2 NSCs and promoting premature neuronal differentiation during postnatal hippocampal development.

Development of a lncRNA-based prognostic signature for oral squamous cell carcinoma.

BACKGROUND: We aimed to establish a long noncoding RNA (lncRNA)-based signature for accurately predicting prognosis and guiding the personalized clinical management of oral squamous cell carcinoma (OSCC). METHODS: OSCC RNA sequencing profiles were acquired from The Cancer Genome Atlas and Gene Expression Omnibus. Univariate Cox regression, least absolute shrinkage and selection operator (LASSO) and multivariate Cox regression analyses were performed to construct a lncRNA-based prognostic signature. Kaplan-Meier survival analysis, receiver operating characteristic (ROC) curves and calibration curves were used to assess the effectiveness and accuracy of the signature. Additionally, we conducted single-sample gene-set enrichment analysis to infer the different degrees of immunocyte infiltration. Weighted correlation network analysis, enrichment analysis and Spearman's correlation analysis were implemented to screen immune-related genes that interact with the lncRNA signature. RESULTS: In total, 14 lncRNAs were defined as potential prognostic biomarkers. Based on these lncRNAs, patients were divided into low- and high-risk subgroups with different survival times (p < 0.001). In addition, the reliability of the prognostic signature was verified by Kaplan-Meier analysis, ROC analysis and calibration curves. Patients in the low-risk group exhibited more significant immune cell infiltration. Simultaneously, a potential regulatory network consisting of eight lncRNAs and 159 protein-coding genes in the top 10 immune-related biological process terms was constructed. CONCLUSIONS: Our findings suggested that the 14-lncRNA signature has satisfactory performance in predicting the prognosis of OSCC, thereby providing new insights to the pathogenesis, clinical patient management and therapeutic intervention. The different immune cell infiltration statuses of OSCC patients may encourage immunotherapy.

Maternal high-salt diet during pregnancy impairs synaptic plasticity and memory in offspring.

Excess salt intake harms the brain health and cognitive functions, but whether a maternal high-salt diet (HSD) affects the brain development and neural plasticity of offspring remains unclear. Here, using a range of behavioral tests, we reported that the offspring of maternal HSD subjects exhibited short- and long-term memory deficits, especially in spatial memory in adulthood. Moreover, impairments in synaptic transmission and plasticity in the hippocampus were observed in adult offspring by using in vivo electrophysiology. Consistently, the number of astrocytes but not neurons in the hippocampus of the offspring from the HSD group were significantly decreased, and ERK and AKT signaling pathways involved in neurodevelopment were highly activated only during juvenile. In addition, the expression of synaptic proteins decreased both in juvenile and adulthood, and this effect might be involved in synaptic dysfunction. Collectively, these data demonstrated that the maternal HSD might cause adult offspring synaptic dysfunction and memory loss. It is possibly due to the reduction of astrocytes in juvenile.

The adsorption characteristics and degradation mechanism of tinidazole on an anatase TiO2 surface: a DFT study.

The adsorption characteristics and degradation mechanism of tinidazole on TiO2(101) and (001) surfaces under vacuum and aqueous solution conditions were studied by density functional theory (DFT). The results show that tinidazole can adsorb on the surfaces of TiO2(101) and (001) under different conditions. The hydrogen bond generated during the adsorption process can enhance the stability of the adsorption configuration, which makes the bond length of C-N of tinidazole longer and finally facilitates the ring-opening degradation reaction. As for the mechanism of the ring-opening degradation reaction, it was found that ring-opening can be carried out along reaction route II on both crystal surfaces, and the reaction activation energy is lower on (101) surface. Under the conditions of aqueous solution, the decrease of the activation energy of the ring-opening degradation reaction indicates that the solvent conditions can promote the degradation reaction.

Theoretical study of the adsorption characteristics and the environmental influence of ornidazole on the surface of photocatalyst TiO2.

In this paper, density functional theory (DFT) was performed to study the adsorption properties of ornidazole on anatase TiO2(101) and (001) crystal facets under vacuum, neutral and acid-base conditions. We calculated the adsorption structure of ornidaozle on the anatase TiO2 surface, optimal adsorption sites, adsorption energy, density of states, electronic density and Milliken atomic charge under different conditions. The results show that when the N(3) atom on the imidazole ring is adsorbed on the Ti(5) atom, the largest adsorption energy and the most stable adsorption configuration could be achieved. According to the analysis of the adsorption configuration, we found that the stability of C(2)-N(3) bond showed a weakening trend. The adsorption wavelengths of the electronic transition between the valence band and conduction band of ornidazole on the TiO2 surface were in the visible light wavelengths range, showing that the TiO2 crystal plane can effectively make use of visible light under different conditions. We speculate the possibility of ornidazole degradation on the surface of TiO2 and found that the reactive site is the C-N bond on the imidazole ring. These discoveries explain the photocatalytic degradation of ornidazole by TiO2 and reveal the microscopic nature of catalytic degradation.

Neural stem cell-derived factors inhibit the growth and invasion of U87 stem-like cells in vitro.

Glioma is one of the most common and aggressive tumors in the brain. Significant attention has been paid to the potential use of neural stem/progenitor cells (NSCs/NPCs) as delivery vehicles to cure gliomas. However, whether the NSCs/NPCs or the factors they produced could make a contribution still remains to be seen. In this study, we focused on the inhibitory effects of the factors produced by NSCs/NPCs on the biological behavior of the glioma stem-like cell in vitro. The human glioma cell line U87 was selected and the U87 stem-like cells were addressed. After being cultured in the NSC condition medium (NSC-CM), the viability and proliferation of U87 stem-like cells were significantly reduced. The invasion of U87 stem-like cells and the migration of U87 cells were also significantly decreased. However, no significant change was observed in regard to the astrocytic differentiation of U87 stem-like cells. These indicated that NSCs/NPCs produced some factors and had an inhibitory effect on the growth and invasion but not the terminal differentiation of U87 stem-like cells. It is worth paying attention to NSCs/NPCs as a high-potential candidate for glioma treatment.

Short term exposure to oxycodone alters the survival, proliferation and differentiation of rat embryonic neural stem cell in vitro.

As one of several opioids, oxycodone has been widely used, particularly in postoperative analgesia in children and cesarean section. However, the effect of oxycodone on developing brain still remains to be seen. Since there is a link between anesthetics exposure and long-term behavioral or cognitive dysfunction in young children, in the current study, the direct effect of oxycodone on neural stem cells (NSCs) biological behaviors was investigated. After exposed to a high dose of oxycodone (10 µg/mL) for 48 h, NSCs survival and proliferation were significantly reduced, while NSCs apoptosis and differentiation were enhanced. These effects were significantly weaker than that when exposed to same dose of morphine. No significant difference was observed regarding to above biological behaviors when exposed to lower doses (0.1 µg/mL and 1.0 µg/mL) of oxycodone. The antagonist of opioid receptor, nalmefene, successfully reversed the influence of oxycodone. Taken together, our results indicated that short term exposure to oxycodone in low dose might be allowed for developing brain.

HIF-1α/Beclin1-Mediated Autophagy Is Involved in Neuroprotection Induced by Hypoxic Preconditioning.

Hypoxic preconditioning (HPC) exerts a protective effect against hypoxic/ischemic brain injury, and one mechanism explaining this effect may involve the upregulation of hypoxia-inducible factor-1 (HIF-1). Autophagy, an endogenous protective mechanism against hypoxic/ischemic injury, is correlated with the activation of the HIF-1α/Beclin1 signaling pathway. Based on previous studies, we hypothesize that the protective role of HPC may involve autophagy occurring via activation of the HIF-1α/Beclin1 signaling pathway. To test this hypothesis, we evaluated the effects of HPC on oxygen-glucose deprivation/reperfusion (OGD/R)-induced apoptosis and autophagy in SH-SY5Y cells. HPC significantly attenuated OGD/R-induced apoptosis, and this effect was suppressed by the autophagy inhibitor 3-methyladenine and mimicked by the autophagy agonist rapamycin. In control SH-SY5Y cells, HPC upregulated the expression of HIF-1α and downstream molecules such as BNIP3 and Beclin1. Additionally, HPC increased the LC3-II/LC3-I ratio and decreased p62 levels. The increase in the LC3-II/LC3-I ratio was inhibited by the HIF-1α inhibitor YC-1 or by Beclin1-short hairpin RNA (shRNA). In OGD/R-treated SH-SY5Y cells, HPC also upregulated the expression levels of HIF-1α, BNIP3, and Beclin1, as well as the LC3-II/LC3-I ratio. Furthermore, YC-1 or Beclin1-shRNA attenuated the HPC-mediated cell viability in OGD/R-treated cells. Taken together, our results demonstrate that HPC protects SH-SY5Y cells against OGD/R via HIF-1α/Beclin1-regulated autophagy.

The inhibiting effect of neural stem cells on proliferation and invasion of glioma cells.

The invasive and infiltrative nature of tumor cells leads to the poor prognosis of glioma. Currently, novel therapeutic means to eliminate the tumor cells without damaging the normal brain tissue are still strongly demanded. Significant attentions had been paid to stem cell-based therapy and neural stem cell (NSC) had been considered as one of the efficient delivery vehicles for targeting therapeutic genes. However, whether the NSCs could directly affect glioma cells remains to be seen. In this study, both rat and human glioma cells (C6 and U251) were co-cultured with normal rat embryonic NSCs directly or in-directly. We found the survival, proliferation, invasion and migration of glioma cells were significantly inhibited, while the differentiation was not affected in the in vitro co-culture system. In nude mice, although no significant difference was observed in the tumor growth, survival status and time of tumor-bearing mice were significantly promoted when U251 cells were subcutaneously injected with NSCs. In coincidence with the suppression of glioma cell growth in vitro, expression of mutant p53 and phosphorylation of AKT, ERK1/2 decreased while the level of caspase-3 increased significantly. Our results suggested that normal NSCs could possess direct anti-glioma properties via inhibiting the glioma cell viability, proliferation, invasion and migration. It could be a very promising candidate for glioma treatment.